Soluble immune checkpoint-related proteins as predictors of tumor recurrence, survival, and T cell phenotypes in clear cell renal cell carcinoma patients

Baseline sLAG-3 levels in Caucasian and African-American breast cancer patients

BACKGROUND

Worse survival persists for African-Americans (AA) with breast cancer compared to other race/ethnic groups despite recent improvements for all. Unstudied in outcomes disparities to date is soluble LAG-3 (sLAG-3), cleaved from the LAG-3 immune checkpoint receptor which is a proposed target for deactivation in emerging immunotherapies due to its prominent immunosuppressive function in the tumoral microenvironment. A prior study has found that lower sLAG-3 baseline level was associated with poor outcomes.

METHODS

In a cross-sectional study of 95 patients with primary breast cancer (n = 58 Caucasian, n = 37 AA), we measured sLAG-3 (ELISA pg/ml) in pre-treatment blood samples using the non-parametric Mann-Whitney u-Test for independent samples, and, calculated Pearson r correlation coefficients of sLAG-3 with circulating cytokines by race.

RESULTS

Mean sLAG-3 level was lower in AA compared to Caucasian patients (1377.6 vs 3690.3, P = .002), and in patients with triple-negative breast cancer (TNBC) compared to those with non-TNBC malignancies (P = .02). When patients with TNBC tumors were excluded from analyses, the difference in sLAG-3 level between AA (n = 21) and Caucasian patients (n = 40) substantially remained (1937.4 vs 4182.4, P = .06). Among Caucasian patients, sLAG-3 was correlated with IL-6, IL-8 and IL-10 (r = .69, P < .001; r = .70, P < .001; and, r = .46, P = .01; respectively). For AA patients, sLAG-3 was correlated only with IL-6 (r = .37, P = .03).

CONCLUSIONS

We present the first report that African-American breast cancer patients might have comparatively low pre-treatment sLAG-3 levels, independent of TNBC status, along with reduced co-expression with circulating cytokines. The mechanistic and prognostic role of cleaved LAG-3, particularly in disparate outcomes, remains to be elucidated.

Liquid biopsy for renal cell carcinoma

Liquid biopsies offer a less invasive alternative to tissue biopsies for diagnosis, prognosis, and determining therapeutic potential in renal cell carcinoma (RCC). Unfortunately, clinical studies using liquid biopsy biomarkers in RCC are limited. Accordingly, we examine RCC biomarkers, derived from urine, plasma, serum and feces of potential impact and clinical outcome in these patients. A PRISMA checklist was used to identify valuable liquid biopsy biomarkers for diagnosis (plasma cfDNA, serum- or urine-derived circulating RNAs, exosomes and proteins), prognosis (plasma cfDNA, plasma- or serum-derived RNAs, and proteins), and therapeutic response (plasma- and serum-derived proteins). Although other analytes have been identified, their application for routine clinical use remains unclear. In general, panels appear more effective than single biomarkers. Important considerations included proof of reproducibility. Unfortunately, many of the examined studies were insufficiently large and lacked multi-center rigor. Cost-effectiveness was also not available. Accordingly, it is clear that more standardized protocols need to be developed before liquid biopsies can be successfully integrated into clinical practice in RCC.

Soluble immune checkpoint molecules in cancer risk, outcomes prediction, and therapeutic applications

Immunotherapy has emerged as a pivotal modality in cancer treatment, with immune checkpoint inhibitors effectively combating malignancies by impeding crucial pathways within the immune system and stimulating patients' immune responses. Soluble forms of immune checkpoints exhibit a remarkable diversity and can be readily tracked in circulation, holding immense potential as biomarkers for cancer treatment. An increasing number of studies focused on soluble immune checkpoints in cancer have emerged thanks to technological advancements. In this systematic review, we comprehensively summarized the recent studies on soluble immune checkpoints in human cancer risk prediction, outcome prediction, therapeutic applications, and potential molecular mechanisms, which demonstrated the promising future of soluble immune checkpoints in clinical applications. The clinical relevance of soluble immune checkpoints has been recognized in multiple cancers, yet the therapeutic applications and mechanisms remain obscure. Interpreting the impacts and mechanisms of soluble immune checkpoints could shed a light on the novel strategies of cancer screening, treatments, and outcome prediction.

Combined approach for predicting the efficacy of nivolumab in head and neck carcinoma by tissue and soluble expressions of PD-L1 and PD-L2

BACKGROUND

Predictive biomarkers for nivolumab in recurrent or metastatic head and neck squamous cell carcinoma (RMHNSCC) have not yet been established.

METHODS

The tumor proportion score (TPS), combined positive score (CPS), and soluble forms of programmed cell death ligand-1 (PD-L1) and programmed cell death ligand-2 (PD-L2) were retrospectively analyzed in patients with RMHNSCC treated with nivolumab.

RESULTS

The positivity rates for TPS (PD-L1), CPS (PD-L1), TPS (PD-L2), and CPS (PD-L2) were 73.8%, 78.2%, 56.4%, and 78.2%, respectively. Patients with high TPS (PD-L1), CPS (PD-L1), or CPS (PD-L1 and PD-L2) showed significantly prolonged progression-free survival. Favorable overall survival was associated with high CPS (PD-L1 and PD-L2) and low soluble PD-L1 and PD-L2 levels. The expressions of tissue and soluble PD-L1/2 were not correlated.

CONCLUSIONS

Our study revealed that compared to PD-L1 expression alone, dual expression of PD-L1 and PD-L2 in tissue or soluble form could be feasible biomarkers in patients with RMHNSCC who received nivolumab.

Immune checkpoint expression as prognostic biomarker candidates in non-small cell lung carcinoma patients

BACKGROUND

Cancer immunotherapy has had an important role in oncologic therapeutics for patients with non-small cell lung cancer (NSCLC) using checkpoint inhibitors. We will explore the possible prognosis biomarker candidates such as: soluble OX40 (sOX40), OX40L (sOX40L), Glucocorticoid-induced tumor necrosis factor receptor family-related receptor (GITR), and their ligand (GITRL), 4-1BB or tumor necrosis factor receptor superfamily 9 (TNFRS9) and inducible T cell co-stimulator (ICOS) in peripheral blood of NSCLC patients.

METHODS

Fifty-eight patients were diagnosed with advanced NSCLC between January 2019 and March 2020.

RESULTS

High sOX40 and low s4-1BB levels in smokers compared non-smoker NSCLC patients. Lower sOX40L levels were found in the male than female (p < 0.05). High sOX40 and sGITRL in stage III compared to the stage IV (p < 0.05). With follow-up at 21.4 months, 44.1% and 91.1% were alive in the sGITRhigh and sGITRlow groups, respectively (p = 0.02), and 73.3% and 27.7% were alive in the sGITRLhigh and sGITRLlow groups, respectively (p = 0.02). At 22 months, 38.7% and 92.3% were alive in the sOX40Lhigh and sOX40Llow groups, respectively (p = 0.01).

CONCLUSION

sGITR, sGITRL, and sOX40L levels were potential prognostic biomarkers and could have an important role as new targets of immunotherapy in NSCLC patients. sGITR, sGITRL, sOX40L, and sOX40 levels were associated with smoking, sex, stage, and age in NSCLC.

The Immune Checkpoint BTLA in Oral Cancer: Expression Analysis and Its Correlation to Other Immune Modulators

In oral squamous cell carcinoma (OSCC) tissues, an immunotolerant situation triggered by immune checkpoints (ICPs) can be observed. Immune checkpoint inhibitors (ICIs) against the PD1/PD-L axis are used with impressive success. However, the response rate is low and the development of acquired resistance to ICI treatment can be observed. Therefore, new treatment strategies especially involving immunological combination therapies need to be developed. The novel negative immune checkpoint BTLA has been suggested as a potential biomarker and target for antibody-based immunotherapy. Moreover, improved response rates could be displayed for tumor patients when antibodies directed against BTLA were used in combination with anti-PD1/PD-L1 therapies. The aim of the study was to check whether the immune checkpoint BTLA is overexpressed in OSCC tissues compared to healthy oral mucosa (NOM) and could be a potential diagnostic biomarker and immunological target in OSCC. In addition, correlation analyses with the expression of other checkpoints should clarify more precisely whether combination therapies are potentially useful for the treatment of OSCC. A total of 207 tissue samples divided into 2 groups were included in the study. The test group comprised 102 tissue samples of OSCC. Oral mucosal tissue from 105 healthy volunteers (NOM) served as the control group. The expression of two isoforms of BTLA (BTLA-1/2), as well as PD1, PD-L1/2 and CD96 was analyzed by RT-qPCR. Additionally, BTLA and CD96 proteins were detected by IHC. Expression levels were compared between the two groups, the relative differences were calculated, and statistical relevance was determined. Furthermore, the expression rates of the immune checkpoints were correlated to each other. BTLA expression was significantly increased in OSCC compared to NOM (pBTLA_1 = 0.003; pBTLA_2 = 0.0001, pIHC = 0.003). The expression of PD1, its ligands PD-L1 and PD-L2, as well as CD96, were also significantly increased in OSCC (p ≤ 0.001). There was a strong positive correlation between BTLA expression and that of the other checkpoints (p < 0.001; ρ ≥ 0.5). BTLA is overexpressed in OSCC and appears to be a relevant local immune checkpoint in OSCC. Thus, antibodies directed against BTLA could be potential candidates for immunotherapies, especially in combination with ICI against the PD1/PD-L axis and CD96.

Soluble immune checkpoints: implications for cancer prognosis and response to immune checkpoint therapy and conventional therapies

Longitudinal sampling of tumor tissue from patients with solid cancers, aside from melanoma and a few other cases, is often unfeasible, and thus may not capture the plasticity of interactions between the tumor and immune system under selective pressure of a given therapy. Peripheral blood analyses provide salient information about the human peripheral immunome while offering technical and practical advantages over traditional tumor biopsies, and should be utilized where possible alongside interrogation of the tumor. Some common blood-based biomarkers used to study the immune response include immune cell subsets, circulating tumor DNA, and protein analytes such as cytokines. With the recent explosion of immune checkpoint inhibitors (ICI) as a modality of treatment in multiple cancer types, soluble immune checkpoints have become a relevant area of investigation for peripheral immune-based biomarkers. However, the exact functions of soluble immune checkpoints and their roles in cancer for the most part remain unclear. This review discusses current literature on the production, function, and expression of nine soluble immune checkpoints - sPD-L1, sPD-1, sCTLA4, sCD80, sTIM3, sLAG3, sB7-H3, sBTLA, and sHVEM - in patients with solid tumors, and explores their role as biomarkers of response to ICI as well as to conventional therapies (chemotherapy, radiotherapy, targeted therapy, and surgery) in cancer patients.

The effect of gD-derived peptides on T cell immune response mediated by BTLA-HVEM protein complex in melanoma patients

Introduction

The effector function of T cells is regulated via immune checkpoints, activating or inhibiting the immune response. The BTLA-HVEM complex, the inhibitory immune checkpoint, may act as one of the tumor immune escape mechanisms. Therefore, interfering with the binding of these proteins can prove beneficial in cancer treatment. Our study focused on peptides interacting with HVEM at the same place as BTLA, thus disrupting the BTLA-HVEM interaction. These peptides' structure and amino acid sequences are based on the gD protein, the ligand of HVEM. Here, we investigated their immunomodulatory potential in melanoma patients.

Methods

Flow cytometry analyses of activation, proliferation, and apoptosis of T cells from patients were performed. Additionally, we evaluated changes within the T cell memory compartment.

Results

The most promising compound - Pep(2), increased the percentages of activated T cells and promoted their proliferation. Additionally, this peptide affected the proliferation rate and apoptosis of melanoma cell line in co-culture with T cells.

Discussion

We conclude that the examined peptide may act as a booster for the immune system. Moreover, the adjuvant and activating properties of the gD-derived peptide could be used in a combinatory therapy with currently used ICI-based treatment. Our studies also demonstrate that even slight differences in the amino acid sequence of peptides and any changes in the position of the disulfide bond can strongly affect the immunomodulatory properties of compounds.

Peripheral Soluble Immune Checkpoint-Related Proteins Were Associated with Survival and Treatment Efficacy of Osteosarcoma Patients, a Cohort Study

BACKGROUND

The immune checkpoint blockade remains obscure in osteosarcoma (OS). We aim to explore the clinical significance of soluble immune checkpoint (ICK)-related proteins in OS.

METHODS

We profiled 14 soluble ICK-related proteins (BTLA, GITR, HVEM, IDO, LAG-3, PD-1, PD-L1, PD-L2, TIM-3, CD28, CD80, CD137, CD27, and CTLA-4) in the plasma of 76 OS patients and matched controls. We evaluated the associations between the biomarkers and the risk of OS using unconditional multivariate logistic regression. The multivariate Cox model was utilized to develop the prediction model of OS. Immune subtypes were established from the identified biomarkers. Transcriptional data from GEO were analyzed to elucidate potential mechanisms.

RESULTS

We found that sTIM3, sCD137, sIDO, and sCTLA4 were significantly correlated with OS risk (all p < 0.05). sBTLA, sPDL2, and sCD27 were significantly associated with the risk of lung metastasis, whereas sBTLA and sTIM3 were associated with the risk of disease progression. We also established an immune subtype based on sBTLA, sPD1, sTIM3, and sPDL2. Patients in the sICK-type2 subtype had significantly decreased progression-free survival (PFS) and lung metastasis-free survival (LMFS) than those in the sICK-type1 subtype (log-rank p = 2.8 × 10-2, 1.7 × 10-2, respectively). Interestingly, we found that the trend of LMFS and PFS in the subtypes of corresponding ICK genes' expression was opposite to the results in the blood (log-rank p = 2.6 × 10-4, 9.5 × 10-4, respectively).

CONCLUSION

Four soluble ICK-related proteins were associated with the survival of OS patients. Soluble ICK-related proteins could be promising biomarkers for the outcomes and immunotherapy of OS patients, though more research is warranted.

Soluble lymphocyte activation gene-3 (sLAG3) and CD4/CD8 ratio dynamics as predictive biomarkers in patients undergoing immune checkpoint blockade for solid malignancies

BACKGROUND

The search for biomarkers to identify suitable candidates for immune checkpoint inhibitor (ICI) therapy remains ongoing. We evaluate how soluble levels of the next generation immune checkpoint Lymphocyte Activation Gene-3 (sLAG-3) and its association with circulating T lymphocyte subsets could pose as a novel biomarker to predict outcome to ICI therapy.

METHODS

Circulating levels of sLAG3 were analyzed using multiplex immunoassay in n = 84 patients undergoing ICI therapy for advanced solid cancer, accompanied by flow cytometry analyses of peripheral blood mononuclear cells (PBMCs).

RESULTS

Uni- and multivariate analysis shows that patients with higher sLAG3 concentrations before ICI therapy had a significantly impaired progression-free (PFS) and overall survival (OS) (HRPFS: 1.005 [95%CI: 1.000-1.009], p = 0.039; HROS: 1.006 [95%CI: 1.001-1.011], p = 0.015). The CD4/CD8 cell ratio and its dynamics during therapy were strong predictors of PFS and OS with patients with a decreasing ratio between baseline and after 1-2 cycles having an improved median OS compared to patients with increasing values (p = 0.012, HR: 3.32). An immunological score combining sLAG3 and the CD4/CD8 ratio showed the highest predictive potential (HROS: 10.3).

CONCLUSION

Pending prospective validation, sLAG3 and correlating circulating T-cell subsets can be used as a non-invasive predictive marker to predict outcome to ICI therapy to help identifying ideal ICI candidates in the future.

PD-L1 as a Urine Biomarker in Renal Cell Carcinoma-A Case Series and Proof-of-Concept Study

BACKGROUND

Renal cell carcinoma (RCC) is among the most lethal urologic malignancies once metastatic. Current treatment approaches for metastatic RCC (mRCC) involve immune checkpoint inhibitors (ICIs) that target the PD-L1/PD-1 axis. High PD-L1 expression in tumor tissue has been identified as a negative prognostic factor in RCC. However, the role of PD-L1 as a liquid biomarker has not yet been fully explored. Herein, we analyze urine levels of PD-L1 in mRCC patients before and after either ICI therapy or surgical intervention, as well as in a series of patients with treatment-naïve RCC.

PATIENTS AND METHODS

The mid-stream urine of patients with mRCC (n = 4) or treatment-naïve RCC, i.e., prior to surgery from two centers (cohort I, n = 49: cohort II, n = 29) was analyzed for PD-L1 by ELISA. The results from cohort I were compared to a control group consisting of patients treated for non-malignant urologic diseases (n = 31). In the mRCC group, urine PD-L1 levels were measured before and after tumor nephrectomy (n = 1) or before and after ICI therapy (n = 3). Exosomal PD-L1 in the urine was analyzed in selected patients by immunoblotting.

RESULTS

A strong decrease in urine PD-L1 levels was found after tumor nephrectomy or following systemic treatment with ICIs. In patients with treatment-naïve RCC (cohort I), urine PD-L1 levels were significantly elevated in the RCC group in comparison to the control group (median 59 pg/mL vs. 25.7 pg/mL, p = 0.011). PD-L1 urine levels were found to be elevated, in particular, in low-grade RCCs in cohorts I and II. Exosomal PD-L1 was detected in the urine of a subset of patients.

CONCLUSION

In this proof-of-concept study, we show that PD-L1 can be detected in the urine of RCC patients. Urine PD-L1 levels were found to correlate with the treatment response in mRCC patients and were significantly elevated in treatment-naïve RCC patients.

Soluble Immune Checkpoint Molecules as Predictors of Efficacy in Immuno-Oncology Combination Therapy in Advanced Renal Cell Carcinoma

Immuno-oncology (IO) combination therapy is the first-line treatment for advanced renal cell carcinoma (RCC). However, biomarkers for predicting the response to IO combination therapy are lacking. Here, we investigated the association between the expression of soluble immune checkpoint molecules and the therapeutic efficacy of IO combination therapy in advanced RCC. The expression of soluble programmed cell death-1 (sPD-1), soluble programmed cell death ligand-1 (sPD-L1), soluble PD-L2 (sPD-L2), and lymphocyte activation gene-3 (sLAG-3) was assessed in plasma samples from 42 patients with advanced RCC who received first-line IO combination therapy. All IMDC risk classifications were represented among the patients, including 14.3, 57.1, and 28.6% with favorable, intermediate, and poor risk, respectively. Univariate analysis revealed that prior nephrectomy, sPD-L2 levels, and sLAG-3 levels were significant factors affecting progression-free survival (PFS), whereas multivariate analyses suggested that sPD-L2 and sLAG-3 levels were independent prognostic factors for PFS. In a univariate analysis of the overall survival, prior nephrectomy and sPD-L2 levels were significant factors; no significant differences were observed in the multivariate analysis. No significant correlation was observed between the sPD-L2 and sLAG-3 levels and PD-L2 and LAG-3 expression via immunohistochemistry. In conclusion, sPD-L2 and sLAG-3 expression may serve as a potential biomarker for predicting IO combination therapy efficacy.

The BTLA-HVEM complex - The future of cancer immunotherapy

The BTLA-HVEM complex plays a pivotal role in cancer and cancer immunotherapy by regulating immune responses. Dysregulation of BTLA and HVEM expression contributes to immunosuppression and tumor progression across various cancer types. Targeting the interaction between BTLA and HVEM holds promise for enhancing anti-tumor immune responses. Disruption of this complex presents a valuable avenue for advancing cancer immunotherapy strategies. Aberrant expression of BTLA and HVEM adversely affects immune cell function, particularly T cells, exacerbating tumor evasion mechanisms. Understanding and modulating the BTLA-HVEM axis represents a crucial aspect of designing effective immunotherapeutic interventions against cancer. Here, we summarize the current knowledge regarding the structure and function of BTLA and HVEM, along with their interaction with each other and various immune partners. Moreover, the expression of soluble and transmembrane forms of BTLA and HVEM in different types of cancer and their impact on the prognosis of patients is also discussed. Additionally, inhibitors of the proteins binding that might be used to block BTLA-HVEM interaction are reviewed. All the presented data highlight the plausible clinical application of BTLA-HVEM targeted therapies in cancer and autoimmune disease management. However, further studies are required to confirm the practical use of this concept. Despite the increasing number of reports on the BTLA-HVEM complex, many aspects of its biology and function still need to be elucidated. This review can be regarded as an encouragement and a guide to follow the path of BTLA-HVEM research.

Identifying molecular subtypes and tumor microenvironment infiltration signatures in kidney renal clear cell carcinoma based on stemness-associated disulfidptosis genes by integrating machine learning, single-cell analyses and experimental validation

Clear cell renal cell carcinoma (ccRCC) is an aggressive malignant tumor. Disulfidptosis is a new programmed cell death mechanism, which is characterized by the abnormal accumulation of intracellular disulfides that are highly toxic to cells. However, the contribution of disulfidptosis to ccRCC progression has not been fully clarified. In this study, two different molecular subtypes related to disulfidptosis were identified in ccRCC patients by the non-negative matrix factorization (NMF) algorithm. The cluster 1 was characterized by a worse prognosis and higher mRNAsi levels. Then, difference analysis and weighted gene co-expression network analysis (WGCNA) were conducted to search modular genes that are highly associated with tumor stemness and tumor microenvironment. Subsequently, a SADG signature containing nine genes was constructed stepwise by WGCNA and least absolute shrinkage and selection operator (LASSO) Cox regression analysis. The high-risk score group had a worse outcome, and immune regulation and metabolic signatures might be responsible for cancer progression in the high-risk group. After that, a predictive nomogram was constructed, and the predicting power of the risk model was verified using inter and three independent external validation datasets. Nine SADGs were shown to significantly correlate with immune infiltration, tumor mutation burden (TMB), microsatellite instability (MSI) and immune checkpoint. In addition, based on the single-cell RNA sequencing dataset (GSE139555), the distribution and expression of nine hub genes in various types of immune cells were analyzed. Finally, the expression level of the nine genes was verified in clinical samples by qRT-PCR.

Soluble receptors in cancer: mechanisms, clinical significance, and therapeutic strategies

Soluble receptors are soluble forms of receptors found in the extracellular space. They have emerged as pivotal regulators of cellular signaling and disease pathogenesis. This review emphasizes their significance in cancer as diagnostic/prognostic markers and potential therapeutic targets. We provide an overview of the mechanisms by which soluble receptors are generated along with their functions. By exploring their involvement in cancer progression, metastasis, and immune evasion, we highlight the importance of soluble receptors, particularly soluble cytokine receptors and immune checkpoints, in the tumor microenvironment. Although current research has illustrated the emerging clinical relevance of soluble receptors, their therapeutic applications remain underexplored. As the landscape of cancer treatment evolves, understanding and targeting soluble receptors might pave the way for novel strategies for cancer diagnosis, prognosis, and therapy.

BTLA biology in cancer: from bench discoveries to clinical potentials

Immune checkpoints play a critical role in maintaining the delicate balance of immune activation in order to prevent potential harm caused by excessive activation, autoimmunity, or tissue damage. B and T lymphocyte attenuator (BTLA) is one of crucial checkpoint, regulating stimulatory and inhibitory signals in immune responses. Its interaction with the herpes virus entry mediator (HVEM) plays an essential role in negatively regulating immune responses, thereby preserving immune homeostasis. In cancer, abnormal cells evade immune surveillance by exploiting checkpoints like BTLA. Upregulated BTLA expression is linked to impaired anti-tumor immunity and unfavorable disease outcomes. In preclinical studies, BTLA-targeted therapies have shown improved treatment outcomes and enhanced antitumor immunity. This review aims to provide an in-depth understanding of BTLA's biology, its role in various cancers, and its potential as a prognostic factor. Additionally, it explores the latest research on BTLA blockade in cancer immunotherapy, offering hope for more effective cancer treatments.

Periprosthetic joint infection and immunity: Current understanding of host-microbe interplay

Periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. Even with current treatments, failure rates are unacceptably high with a 5-year mortality rate of 26%. Majority of the literature in the field has focused on development of better biomarkers for diagnostics and treatment strategies including innovate antibiotic delivery systems, antibiofilm agents, and bacteriophages. Nevertheless, the role of the immune system, our first line of defense during PJI, is not well understood. Evidence of infection in PJI patients is found within circulation, synovial fluid, and tissue and include numerous cytokines, metabolites, antimicrobial peptides, and soluble receptors that are part of the PJI diagnosis workup. Macrophages, neutrophils, and myeloid-derived suppressor cells (MDSCs) are initially recruited into the joint by chemokines and cytokines produced by immune cells and bacteria and are activated by pathogen-associated molecular patterns. While these cells are efficient killers of planktonic bacteria by phagocytosis, opsonization, degranulation, and recruitment of adaptive immune cells, biofilm-associated bacteria are troublesome. Biofilm is not only a physical barrier for the immune system but also elicits effector functions. Additionally, bacteria have developed mechanisms to evade the immune system by inactivating effector molecules, promoting killing or anti-inflammatory effector cell phenotypes, and intracellular persistence and dissemination. Understanding these shortcomings and the mechanisms by which bacteria can subvert the immune system may open new approaches to better prepare our own immune system to combat PJI. Furthermore, preoperative immune system assessment and screening for dysregulation may aid in developing preventative interventions to decrease PJI incidence.

Soluble Forms of Immune Checkpoints and Their Ligands as Potential Biomarkers in the Diagnosis of Recurrent Pregnancy Loss-A Preliminary Study

Immune checkpoints (ICPs) serve as regulatory switches on immune-competent cells. Soluble ICPs consist of fragments derived from ICP molecules typically located on cell membranes. Research has demonstrated that they perform similar functions to their membrane-bound counterparts but are directly present in the bloodstream. Effective control of the maternal immune system is vital for a successful pregnancy due to genetic differences between the mother and fetus. Abnormalities in the immune response are widely acknowledged as the primary cause of spontaneous abortions. In our research, we introduce a novel approach to understanding the immune-mediated mechanisms underlying recurrent miscarriages and explore new possibilities for diagnosing and preventing pregnancy loss. The female participants in the study were divided into three groups: RSA (recurrent spontaneous abortion), pregnant, and non-pregnant women. The analysis of soluble forms of immune checkpoints and their ligands in the serum of the study groups was conducted using the Luminex method Statistically significant differences in the concentrations of (ICPs) were observed between physiological pregnancies and the RSA group. Among patients with RSA, we noted reduced concentrations of sGalectin-9, sTIM-3, and sCD155, along with elevated concentrations of LAG-3, sCD80, and sCD86 ICPs, in comparison to physiological pregnancies. Our study indicates that sGalectin-9, TIM-3, sLAG-3, sCD80, sCD86, sVISTA, sNectin-2, and sCD155 could potentially serve as biological markers of a healthy, physiological pregnancy. These findings suggest that changes in the concentrations of soluble immune checkpoints may have the potential to act as markers for early pregnancy loss.

Serum immune checkpoint profiling identifies soluble CD40 as a biomarker for pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) responds poorly to systemic treatment, including new immunotherapeutic approaches. Biomarkers are urgently needed for early disease detection, patient stratification for treatment, and response prediction. The role of soluble CD40 (sCD40) is unknown in PDAC. In this study, we performed a quantitative multiplex analysis of 17 immune checkpoint proteins in serum samples from patients with various stages of PDAC in a discovery study (n = 107) and analyzed sCD40 by ELISA in a validation study (n = 317). Youden's J statistic was used for diagnostic cut-off optimization. A Cox proportional hazards regression model was applied in an empiric approach for prognostic threshold optimization. Kaplan-Meier estimator and multivariable Cox regression analyses were used for survival analysis. sCD40 was significantly increased in the serum of patients with PDAC compared to healthy cohorts and patients with IPMN. In the validation cohort, the area under the receiver operating characteristic (ROC) c-statistic was 0.8, and combining sCD40 with CA19-9 yielded a c-statistic of 0.95. sCD40 levels were independent of the tumor stage. However, patients who received neoadjuvant chemotherapy had significantly lower sCD40 levels than those who underwent upfront surgery. Patients with a sCD40 level above the empirical threshold of 0.83 ng/ml had a significantly reduced overall survival with a hazard ratio of 1.4. This observation was pronounced in patients after neoadjuvant chemotherapy. Collectively, soluble CD40 may be considered as both a diagnostic and prognostic non-invasive biomarker in PDAC.

Establishing a prognostic model based on immune-related genes and identification of BIRC5 as a potential biomarker for lung adenocarcinoma patients

BACKGROUND

Lung adenocarcinoma (LUAD) is an extraordinarily malignant tumor, with rapidly increasing morbidity and poor prognosis. Immunotherapy has emerged as a hopeful therapeutic modality for lung adenocarcinoma. Furthermore, a prognostic model (based on immune genes) can fulfill the purpose of early diagnosis and accurate prognostic prediction.

METHODS

Immune-related mRNAs (IRmRNAs) were utilized to construct a prognostic model that sorted patients into high- and low-risk groups. Then, the prediction efficacy of our model was evaluated using a nomogram. The differences in overall survival (OS), the tumor mutation landscape, and the tumor microenvironment were further explored between different risk groups. In addition, the immune genes comprising the prognostic model were subjected to single-cell RNA sequencing to investigate the expression of these immune genes in different cells. Finally, the functions of BIRC5 were validated through in vitro experiments.

RESULTS

Patients in different risk groups exhibited sharply significant variations in OS, pathway activity, immune cell infiltration, mutation patterns, and immune response. Single-cell RNA sequencing revealed that the expression level of BIRC5 was significantly high in T cells. Cell experiments further revealed that BIRC5 knockdown markedly reduced LUAD cell proliferation.

CONCLUSION

This model can function as an instrumental variable in the prognostic, molecular, and therapeutic prediction of LUAD, shedding new light on the optimal clinical practice guidelines for LUAD patients.

Systematic analysis of RNASET2 gene as a potential prognostic and immunological biomarker in clear cell renal cell carcinoma

BACKGROUND

RNASET2 has been identified as an oncogene with anti-angiogenic and immunomodulatory effects in a variety of cancers, but its function in clear cell renal cell carcinoma (ccRCC) is still not well understood.

METHODS

The RNASET2 expression matrix was extracted from the The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets and analyzed for diagnostic and prognostic value. RNASET2 mRNA expression was detected by quantitative polymerase chain reaction (qPCR) in ccRCC patients and renal cancer cell lines. Wound healing assay, transwell assay, western blotting, and tube formation assays were used to evaluate the function of RNASET2 in renal cancer in vitro. In addition, transcriptome sequencing was performed on knockdown RNASET2 kidney cancer cells to analyze their potential signaling pathways. Moreover, the immune microenvironment and mutational status were evaluated to predict the potential mechanisms of RNASET2 involvement in renal cancer progression. Sensitivity to common chemotherapeutic and targeted agents was assessed according to the Genomics of Drug Sensitivity in Cancer (GDSC) database.

RESULTS

RNASET2 expression was significantly upregulated in ccRCC tissues and renal cancer cell lines, predicting poor prognosis for patients. In vitro experiments showed that silencing RNASET2 inhibited the migration and pro-angiogenic ability of renal cancer cells. Transcriptome sequencing suggested its possible involvement in the remodeling of the immune microenvironment in renal cell carcinoma. Furthermore, bioinformatics analysis and immunohistochemical staining showed that RNASET2 was positively correlated with the infiltration abundance of regulatory T cells. Finally, we mapped the mutational landscape of RNASET2 in ccRCC and found its predictive value for drug sensitivity.

CONCLUSIONS

Our results suggest that RNASET2 is a promising biomarker and therapeutic target in ccRCC.

Tumor microenvironment-based signatures distinguish intratumoral heterogeneity, prognosis, and immunogenomic features of clear cell renal cell carcinoma

Background

The tumor microenvironment (TME) performs a crucial function in the tumorigenesis and response to immunotherapies of clear cell renal cell carcinoma (ccRCC). However, a lack of recognized pre-clinical TME-based risk models poses a great challenge to investigating the risk factors correlated with prognosis and treatment responses for patients with ccRCC.

Methods

Stromal and immune contexture were assessed to calculate the TMErisk score of a large sample of patients with ccRCC from public and real-world cohorts using machine-learning algorithms. Next, analyses for prognostic efficacy, correlations with clinicopathological features, functional enrichment, immune cell distributions, DNA variations, immune response, and heterogeneity were performed and validated.

Results

Clinical hub genes, including INAFM2, SRPX, DPYSL3, VSIG4, APLNR, FHL5, A2M, SLFN11, ADAMTS4, IFITM1, NOD2, CCR4, HLA-DQB2, and PLAUR, were identified and incorporated to develop the TMErisk signature. Patients in the TMEhigh risk group (category) exhibited a considerably grim prognosis, and the TMErisk model was shown to independently function as a risk indicator for the overall survival (OS) of ccRCC patients. Expression levels of immune checkpoint genes were substantially increased in TMEhigh risk group, while those of the human leukocyte antigen (HLA) family genes were prominently decreased. In addition, tumors in the TMEhigh group showed significantly high infiltration levels of tumor-infiltrated lymphocytes, including M2 macrophages, CD8+ T cells, B cells, and CD4+ T cells. In heterogeneity analysis, more frequent somatic mutations, including pro-tumorigenic BAP1 and PBRM1, were observed in the TMEhigh group. Importantly, 19.3% of patients receiving immunotherapies in the TMEhigh group achieved complete or partial response compared with those with immune tolerance in the TMElow group, suggesting that TMErisk prominently differentiates prognosis and responses to immunotherapy for patients with ccRCC.

Conclusions

We first established the TMErisk score of ccRCC using machine-learning algorithms based on a large-scale population. The TMErisk score can be utilized as an innovative independent prognosis predictive marker with high sensitivity and accuracy. Our discovery also predicted the efficacy of immunotherapy in ccRCC patients, indicating the intimate link between tumor immune microenvironment and intratumoral heterogeneity.

BTLA-derived peptides as inhibitors of BTLA/HVEM complex formation - design, synthesis and biological evaluation

Immune checkpoints can be divided into co-stimulatory and co-inhibitory molecules that regulate the activation and effector functions of T cells. The co-inhibitory pathways mediated by ICPs are used by cancer cells to escape from immune surveillance, and therefore the blockade of these receptor/ligand interactions is one of the strategies used in the treatment of cancer. The two main pathways currently under investigation are CTLA-4/CD80/CD86 and PD-1/PD-L1, and the monoclonal Abs targeting them have shown potent immunomodulatory effects and activity in clinical environments. Another interesting target in cancer treatment is the BTLA/HVEM complex. Binding of BTLA protein on T cells to HVEM on cancer cells leads to inhibition of T cell proliferation and cytokine production. In the presented work, we focused on blocking the HVEM protein using BTLA-derived peptides. Based on the crystal structure of the BTLA/HVEM complex and MM/GBSA analysis performed here, we designed and synthesized peptides, specifically fragments of BTLA protein. We subsequently checked the inhibitory capacities of these compounds using ELISA and a cellular reporter platform. Two of these peptides, namely BTLA(35-43) and BTLA(33-64)C58Abu displayed the most promising properties, and we therefore performed further studies to evaluate their affinity to HVEM protein, their stability in plasma and their effect on viability of human PBMCs. In addition, the 3D structure for the peptide BTLA(33-64)C58Abu was determined using NMR. Obtained data confirmed that the BTLA-derived peptides could be the basis for future drugs and their immunomodulatory potential merits further examination.

Beyond the anti-PD-1/PD-L1 era: promising role of the BTLA/HVEM axis as a future target for cancer immunotherapy

Recent introduction of monoclonal antibodies targeting immune checkpoints to harness antitumor immunity has revolutionized the cancer treatment landscape. The therapeutic success of immune checkpoint blockade (ICB)-based therapies mainly relies on PD-1/PD-L1 and CTLA-4 blockade. However, the limited overall responses and lack of reliable predictive biomarkers of patient´s response are major pitfalls limiting immunotherapy success. Hence, this reflects the compelling need of unveiling novel targets for immunotherapy that allow to expand the spectrum of ICB-based strategies to achieve optimal therapeutic efficacy and benefit for cancer patients. This review thoroughly dissects current molecular and functional knowledge of BTLA/HVEM axis and the future perspectives to become a target for cancer immunotherapy. BTLA/HVEM dysregulation is commonly found and linked to poor prognosis in solid and hematological malignancies. Moreover, circulating BTLA has been revealed as a blood-based predictive biomarker of immunotherapy response in various cancers. On this basis, BTLA/HVEM axis emerges as a novel promising target for cancer immunotherapy. This prompted rapid development and clinical testing of the anti-BTLA blocking antibody Tifcemalimab/icatolimab as the first BTLA-targeted therapy in various ongoing phase I clinical trials with encouraging results on preliminary efficacy and safety profile as monotherapy and combined with other anti-PD-1/PD-L1 therapies. Nevertheless, it is anticipated that the intricate signaling network constituted by BTLA/HVEM/CD160/LIGHT involved in immune response regulation, tumor development and tumor microenvironment could limit therapeutic success. Therefore, in-depth functional characterization in different cancer settings is highly recommended for adequate design and implementation of BTLA-targeted therapies to guarantee the best clinical outcomes to benefit cancer patients.

Immune checkpoints and cancer immunotherapies: insights into newly potential receptors and ligands

Checkpoint markers and immune checkpoint inhibitors have been increasingly identified and developed as potential immunotherapeutic targets in various human cancers. Despite valuable efforts to discover novel immune checkpoints and their ligands, the precise roles of their therapeutic functions, as well as the broad identification of their counterpart receptors, remain to be addressed. In this context, it has been suggested that various putative checkpoint receptors can be induced upon activation. In the tumor microenvironment, T cells, as crucial immune response against malignant diseases as well as other immune central effector cells, such as natural killer cells, are regulated via co-stimulatory or co-inhibitory signals from immune or tumor cells. Studies have shown that exposure of T cells to tumor antigens upregulates the expression of inhibitory checkpoint receptors, leading to T-cell dysfunction or exhaustion. Although targeting immune checkpoint regulators has shown relative clinical efficacy in some tumor types, most trials in the field of cancer immunotherapies have revealed unsatisfactory results due to de novo or adaptive resistance in cancer patients. To overcome these obstacles, combinational therapies with newly discovered inhibitory molecules or combined blockage of several checkpoints provide a rationale for further research. Moreover, precise identification of their receptors counterparts at crucial checkpoints is likely to promise effective therapies. In this review, we examine the prospects for the application of newly emerging checkpoints, such as T-cell immunoglobulin and mucin domain 3, lymphocyte activation gene-3, T-cell immunoreceptor with Ig and ITIM domains (TIGIT), V-domain Ig suppressor of T-cell activation (VISTA), new B7 family proteins, and B- and T-cell lymphocyte attenuator, in association with immunotherapy of malignancies. In addition, their clinical and biological significance is discussed, including their expression in various human cancers, along with their roles in T-cell-mediated immune responses.

Immune-checkpoint proteins, cytokines, and microbiome impact on patients with cervical insufficiency and preterm birth

Background

Microenvironmental factors, including microbe-induced inflammation and immune-checkpoint proteins that modulate immune cells have been associated with both cervical insufficiency and preterm delivery. These factors are incompletely understood. This study aimed to explore and compare interactions among microbiome and inflammatory factors, such as cytokines and immune-checkpoint proteins, in patients with cervical insufficiency and preterm birth. In particular, factors related to predicting preterm birth were identified and the performance of the combination of these factors was evaluated.

Methods

A total of 220 swab samples from 110 pregnant women, prospectively recruited at the High-Risk Maternal Neonatal Intensive Care Center, were collected between February 2020 and March 2021. This study included 63 patients with cervical insufficiency receiving cerclage and 47 control participants. Endo- and exocervical swabs and fluids were collected simultaneously. Shotgun metagenomic sequencing for the microbiome and the measurement of 34 immune-checkpoint proteins and inflammatory cytokines were performed.

Results

First, we demonstrated that immune-checkpoint proteins, the key immune-regulatory molecules, could be measured in endocervical and exocervical samples. Secondly, we identified significantly different microenvironments in cervical insufficiency and preterm birth, with precise cervical locations, to provide information about practically useful cervical locations in clinical settings. Finally, the presence of Moraxella osloensis (odds ratio = 14.785; P = 0.037) and chemokine CC motif ligand 2 levels higher than 73 pg/mL (odds ratio = 40.049; P = 0.005) in endocervical samples were associated with preterm birth. Combining M. osloensis and chemokine CC motif ligand 2 yielded excellent performance for predicting preterm birth (area under the receiver operating characteristic curve = 0.846, 95% confidence interval = 0.733-0.925).

Conclusion

Multiple relationships between microbiomes, immune-checkpoint proteins, and inflammatory cytokines in the cervical microenvironment were identified. We focus on these factors to aid in the comprehensive understanding and therapeutic modulation of local microbial and immunologic compositions for the management of cervical insufficiency and preterm birth.

Cuproptosis-related gene expression is associated with immune infiltration and CD47/CD24 expression in glioblastoma, and a risk score based on these genes can predict the survival and prognosis of patients

Introduction

Glioblastoma (GBM) is the most invasive type of glioma, is insensitive to radiotherapy and chemotherapy, and has high proliferation and invasive ability, with a 5-year survival rate of <5%. Cuproptosis-related genes (CRGs) have been successfully used to predict the prognosis of many types of tumors. However, the relationship between cuproptosis and GBM remains unclear.

Methods

Here, we sought to identify CRGs in GBM and elucidate their role in the tumor immune microenvironment and prognosis. To that aim, changes in CRGs in The Cancer Genome Atlas (TCGA) transcriptional and Gene Expression Omnibus (GEO) datasets (GEO4290 and GEO15824) were characterized, and the expression patterns of these genes were analyzed.

Results

A risk score based on CRG expression characteristics could predict the survival and prognosis of patients with GBM and was significantly associated with immune infiltration levels and the expression of CD47 and CD24, which are immune checkpoints of the "don't eat me "signal. Furthermore, we found that the CDKN2A gene may predict GBM sensitivity and resistance to drugs.

Discussion

Our findings suggest that CRGs play a crucial role in GBM outcomes and provide new insights into CRG-related target drugs/molecules for cancer prevention and treatment.

The predictive role of soluble programmed death ligand 1 in digestive system cancers

Introduction

The prognostic role of soluble programmed death ligand 1 (sPD-L1) in digestive system cancers (DSCs) remains inconclusive. This study aimed to explore the predictive value of sPD-L1 expression in DSCs.

Methods

Comprehensive searches were run on the electronic databases (PubMed, Web of Science, EMBASE, and the Cochrane Library) to identify studies that assessed the prognostic role of sPD-L1 in DSCs. Review Manager software (version 5.3) was used for all analyses. Pooled data for survival outcomes were measured as hazard ratios (HRs), 95% confidence intervals (CIs), and odds ratios and their 95% CIs.

Results

The search identified 18 studies involving 2,070 patients with DSCs. The meta-outcome revealed that a high level of sPD-L1 was related to poorer overall survival (HR, 3.06; 95% CI: 2.22-4.22, p<0.001) and disease-free survival (HR, 2.53; 95% CI: 1.67-3.83, p<0.001) in DSCs. Individually, the prognostic significance of high level of sPD-L1 expression was the highest in hepatic cell carcinoma (HR, 4.76; p<0.001) followed by gastric cancer (HR=3.55, p<0.001).

Conclusion

sPD-L1 may be a prognostic factor in DSCs for overall survival and disease-free survival. Inflammatory cytokines, treatment approaches, and other factors may affect the expression of sPD-L1. Therefore, the prognostic value of sPD-L1 for recurrence and metastasis should be further investigated. sPD-L1 may also predict response to treatment. Well-designed prospective studies with standard assessment methods should be conducted to determine the prognostic value of sPD-L1 in DSCs.

Biological Biomarkers of Response and Resistance to Immune Checkpoint Inhibitors in Renal Cell Carcinoma

Renal cell carcinoma (RCC) represents around 2% of cancer-related deaths worldwide per year. RCC is an immunogenic malignancy, and treatment of metastatic RCC (mRCC) has greatly improved since the advent of the new immunotherapy agents, including immune checkpoint inhibitors (ICIs). However, it should be stressed that a large proportion of patients does not respond to these therapies. There is thus an urgent need to identify predictive biomarkers of efficacy or resistance associated with ICIs or ICI/Tyrosine kinase inhibitor (TKI) combinations; this is a major challenge to achieve precision medicine for mRCC in routine practice. To identify potential biomarkers, it is necessary to improve our knowledge on the biology of immune checkpoints. A lot of efforts have been made over the last decade in the field of immuno-oncology. We summarize here the main data obtained in this field when considering mRCC. As for clinical biomarkers, clinician and scientific experts of the domain are facing difficulties in identifying such molecular entities, probably due to the complexity of immuno-oncology and the constant adaptation of tumor cells to their changing environment.

Prediction of risk and overall survival of pancreatic cancer from blood soluble immune checkpoint-related proteins

Background

Immune checkpoint inhibition holds promise as a novel treatment for pancreatic ductal adenocarcinoma (PDAC). The clinical significance of soluble immune checkpoint (ICK) related proteins have not yet fully explored in PDAC.

Methods

We comprehensively profiled 14 soluble ICK-related proteins in plasma in 70 PDAC patients and 70 matched healthy controls. Epidemiological data of all subjects were obtained through structured interviews, and patients' clinical data were retrieved from electronical health records. We evaluated the associations between the biomarkers with the risk of PDAC using unconditional multivariate logistic regression. Consensus clustering (k-means algorithm) with significant biomarkers was performed to identify immune subtypes in PDAC patients. Prediction models for overall survival (OS) in PDAC patients were developed using multivariate Cox proportional hazards regression. Harrell's concordance index (C-index), time-dependent receiver operating characteristic (ROC) curve and calibration curve were utilized to evaluate performance of prediction models. Gene expressions of the identified ICK-related proteins in tumors from TCGA were analyzed to provide insight into underlying mechanisms.

Results

Soluble BTLA, CD28, CD137, GITR and LAG-3 were significantly upregulated in PDAC patients (all q < 0.05), and elevation of each of them was correlated with PDAC increased risk (all p < 0.05). PDAC patients were classified into soluble immune-high and soluble immune-low subtypes, using these 5 biomarkers. Patients in soluble immune-high subtype had significantly poorer OS than those in soluble immune-low subtype (log-rank p = 9.7E-03). The model with clinical variables and soluble immune subtypes had excellent predictive power (C-index = 0.809) for the OS of PDAC patients. Furthermore, the immune subtypes identified with corresponding genes' expression in PDAC tumor samples in TCGA showed an opposite correlation with OS to that of immune subtypes based on blood soluble ICK-related proteins (log-rank p =0.02). The immune-high subtype tumors displayed higher cytolytic activity (CYT) score than immune-low subtype tumors (p < 2E-16).

Conclusion

Five soluble ICK-related proteins were identified to be significantly associated with the risk and prognosis of PDAC. Patients who were classified as soluble immune-low subtype based on these biomarkers had better overall survival than those of the soluble immune-high subtype.

Dysregulation of systemic soluble immune checkpoints in early breast cancer is attenuated following administration of neoadjuvant chemotherapy and is associated with recovery of CD27, CD28, CD40, CD80, ICOS and GITR and substantially increased levels of PD-L1, LAG-3 and TIM-3

Neoadjuvant chemotherapy (NAC) may alter the immune landscape of patients with early breast cancer (BC), potentially setting the scene for more effective implementation of checkpoint-targeted immunotherapy. This issue has been investigated in the current study in which alterations in the plasma concentrations of 16 soluble co-stimulatory and co-inhibitory, immune checkpoints were measured sequentially in a cohort of newly diagnosed, early BC patients (n=72), pre-treatment, post-NAC and post-surgery using a Multiplex® bead array platform. Relative to a group of healthy control subjects (n=45), the median pre-treatment levels of five co-stimulatory (CD27, CD40, GITRL, ICOS, GITR) and three co-inhibitory (TIM-3, CTLA-4, PD-L1) soluble checkpoints were significantly lower in the BC patients vs. controls (p&lt;0.021-p&lt;0.0001; and p&lt;0.008-p&lt;0.00001, respectively). Following NAC, the plasma levels of six soluble co-stimulatory checkpoints (CD28, CD40, ICOS, CD27, CD80, GITR), all involved in activation of CD8+ cytotoxic T cells, were significantly increased (p&lt;0.04-p&lt;0.00001), comparable with control values and remained at these levels post-surgery. Of the soluble co-inhibitory checkpoints, three (LAG-3, PD-L1, TIM-3) increased significantly post-NAC, reaching levels significantly greater than those of the control group. PD-1 remained unchanged, while BTLA and CTLA-4 decreased significantly (p&lt;0.03 and p&lt;0.00001, respectively). Normalization of soluble co-stimulatory immune checkpoints is seemingly indicative of reversal of systemic immune dysregulation following administration of NAC in early BC, while recovery of immune homeostasis may explain the increased levels of several negative checkpoint proteins, albeit with the exceptions of CTLA-4 and PD-1. Although a pathological complete response (pCR) was documented in 61% of patients (mostly triple-negative BC), surprisingly, none of the soluble immune checkpoints correlated with the pCR, either pre-treatment or post-NAC. Nevertheless, in the case of the co-stimulatory ICMs, these novel findings are indicative of the immune-restorative potential of NAC in early BC, while in the case of the co-inhibitory ICMs, elevated levels of soluble PD-L1, LAG-3 and TIM-3 post-NAC underscore the augmentative immunotherapeutic promise of targeting these molecules, either individually or in combination, as a strategy, which may contribute to the improved management of early BC.

Identification of fatty acid metabolism-based molecular subtypes and prognostic signature to predict immune landscape and guide clinical drug treatment in renal clear cell carcinoma

Three subtypes of samples were generated based on genes involved in fatty acid metabolism in The Cancer Genome Atlas (TCGA)-RCC patients using a non-negative matrix factorization (NMF) algorithm. 32 co-expressed modules were identified using WCGNA. We constructed a four-gene signature in our training set using least absolute shrinkage selection operator regression analysis and verified it in our testing and overall sets. A relevant study analysis in clinical trials was conducted, which showed the model had good stability and potential application value for predicting outcomes. We analyzed the immune microenvironment using MCPcounter, CIBERSORT, quanTIseq, TIMER and ESTIMATE algorithms, and the result indicated risk was positively related to T cells, B-lineage, and fibroblasts and negatively correlated with monocytic lineage, myeloid dendritic cells, neutrophils, and endothelial cells, and CPT1B was positively related to T cells, CD8 + T cells, Cytotoxic lymphocytes and NK cells, and negatively correlated with myeloid dendritic cells, fibroblasts, endothelial cells. Tumor mutation burden was positively related to risk score and the expression of CPT1B using the R packages corrplot, circlize. Through the R package pRRophetic, drug sensitivity tests showed that the low-risk score group would benefit more from sunitinib and less from pazopanib, sorafenib, temsirolimus, gemcitabine and doxorubicin than the high-risk score group. We performed the relevant basic assay validation for CPT1B, and the proliferation ability of RCC cells was inhibited after the knockdown of protein expression of CPT1B. In conclusion, we established a four-gene model that can predict outcomes of RCC with potential applications in diagnosis and treatment.

Soluble TIM-3 as a biomarker of progression and therapeutic response in cancers and other of human diseases

Immune checkpoints inhibition is a privileged approach to combat cancers and other human diseases. The TIM-3 (T cell immunoglobulin and mucin-domain containing-3) inhibitory checkpoint expressed on different types of immune cells is actively investigated as an anticancer target, with a dozen of monoclonal antibodies in (pre)clinical development. A soluble form sTIM-3 can be found in the plasma of patients with cancer and other diseases. This active circulating protein originates from the proteolytic cleavage by two ADAM metalloproteases of the membrane receptor shared by tumor and non-tumor cells, and extracellular vesicles. In most cancers but not all, overexpression of mTIM-3 at the cell surface leads to high level of sTIM-3. Similarly, elevated levels of sTIM-3 have been reported in chronic autoimmune diseases, inflammatory gastro-intestinal diseases, certain viral and parasitic diseases, but also in cases of organ transplantation and in pregnancy-related pathologies. We have analyzed the origin of sTIM-3, its methods of dosage in blood or plasma, its presence in multiple diseases and its potential role as a biomarker to follow disease progression and/or the treatment response. In contrast to sPD-L1 generated by different classes of proteases and by alternative splicing, sTIM-3 is uniquely produced upon ADAM-dependent shedding, providing a more homogenous molecular entity and a possibly more reliable molecular marker. However, the biological functionality of sTIM-3 remains insufficiently characterized. The review shed light on pathologies associated with an altered expression of sTIM-3 in human plasma and the possibility to use sTIM-3 as a diagnostic or therapeutic marker.

Metabolic classifications of renal cell carcinoma reveal intrinsic connections with clinical and immune characteristics

BACKGROUND

Kidney cancer undergoes a dramatic metabolic shift and has demonstrated responsiveness to immunotherapeutic intervention. However, metabolic classification and the associations between metabolic alterations and immune infiltration in Renal cell carcinoma still remain elucidative.

METHODS

Unsupervised consensus clustering was conducted on the TCGA cohorts for metabolic classification. GESA, mRNAsi, prognosis, clinical features, mutation load, immune infiltration and differentially expressed gene differences among different clusters were compared. The prognosis model and nomograms were constructed based on metabolic gene signatures and verified using external ICGC datasets. Immunohistochemical results from Human Protein Atlas database and Tongji hospital were used to validate gene expression levels in normal tissues and tumor samples. CCK8, apoptosis analysis, qPCR, subcutaneously implanted murine models and flowcytometry analysis were applied to investigate the roles of ACAA2 in tumor progression and anti-tumor immunity.

RESULTS

Renal cell carcinoma was classified into 3 metabolic subclusters and the subcluster with low metabolic profiles displayed the poorest prognosis, highest invasiveness and AJCC grade, enhanced immune infiltration but suppressive immunophenotypes. ACAA2, ACAT1, ASRGL1, AKR1B10, ABCC2, ANGPTL4 were identified to construct the 6 gene-signature prognosis model and verified both internally and externally with ICGC cohorts. ACAA2 was demonstrated as a tumor suppressor and was associated with higher immune infiltration and elevated PD-1 expression of CD8⁺ T cells.

CONCLUSIONS

Our research proposed a new metabolic classification method for RCC and revealed intrinsic associations between metabolic phenotypes and immune profiles. The identified gene signatures might serve as key factors bridging tumor metabolism and tumor immunity and warrant further in-depth investigations.

A 3D Ex Vivo Tumor-Immune Coculture System Mimicking In Vivo Tumor Environmental Stress on CD8+ T Cells Exhaustion

Dissection of exhaustion trajectories of immune cells under tumor selection pressure in the tumor microenvironment (TME) elucidates the underlying machinery in anti-tumor immunity, which still lacks easy-to-use models to decipher. Herein, gelatin methacryloyl (GelMA)-poly (ethylene oxide) (PEO) based 3D hydrogel microspheroids are constructed with non-immunogenicity and controllable macroporous structure to establish a tumor-immune cell coculture (3D-HyGTIC) system. In 3D-HyGTIC system, when immune cells embarked, stepwise up-regulation of main immune checkpoints (ICs) molecules is observed with compromised cytokine production in CD8⁺ T cells, the trajectory of which is in lineage correlation with in vivo grafted tumors. Reinvigoration of CD8⁺ T cells is more obvious with the addition of an anti-PD-1 regimen at the early time point, which is recapitulated during the coculture of patient-derived tumor fragments (PDTF) and autologous T cells. Moreover, the upregulation of LAG-3 on CD8⁺ T cells after anti-PD-1 treatment is uncovered. Sequential addition of anti-LAG-3 successfully rescues the otherwise failed reactivation of CD8⁺ T cells. Therefore, the 3D-HyGTIC system is not only inclined to mimic the early differentiation trajectories of tumor-infiltrating CD8⁺ T cells but also may facilitate an evaluation of the efficacy of IC blockades and guide the designing of combination immunotherapy.

The association of BTLA gene polymorphisms with non-small lung cancer risk in smokers and never-smokers

Introduction

Lung cancer is the predominant cause of death among cancer patients and non-small cell lung cancer (NSCLC) is the most common type. Cigarette smoking is the prevailing risk factor for NSCLC, nevertheless, this cancer is also diagnosed in never-smokers. B and T lymphocyte attenuator (BTLA) belongs to immunological checkpoints which are key regulatory molecules of the immune response. A growing body of evidence highlights the important role of BTLA in cancer. In our previous studies, we showed a significant association between BTLA gene variants and susceptibility to chronic lymphoblastic leukemia and renal cell carcinoma in the Polish population. The present study aimed to analyze the impact of BTLA polymorphic variants on the susceptibility to NSCLC and NSCLC patients' overall survival (OS).

Methods

Using TaqMan probes we genotyped seven BTLA single-nucleotide polymorphisms (SNPs): rs2705511, rs1982809, rs9288952, rs9288953, rs1844089, rs11921669 and rs2633582 with the use of ViiA 7 Real-Time PCR System.

Results

We found that rs1982809 within BTLA is associated with NSCLC risk, where carriers of rs1982809G allele (AG+GG genotypes) were more frequent in patients compared to controls. In subgroup analyses, we also noticed that rs1982809G carriers are significantly overrepresented in never-smokers, but not in smokers compared to controls. Additionally, the global distribution of the haplotypes differed between the never-smokers and smokers, where haplotypes A G G C A, C G A C G, and C G A T G were more frequent in never-smoking patients. Furthermore, the presence rs1982809G (AG+GG genotypes) allele as well as the presence of rs9288953T allele (CT+TT genotypes) increased NSCLC risk in females' patients. After stratification by histological type, we noticed that rs1982809G and rs2705511C carriers were more frequent among adenocarcinoma patients. Moreover, rs1982809G and rs2705511C correlated with the more advanced stages of NSCLC (stage II and III), but not with stage IV. Furthermore, we showed that rs2705511 and rs1982809 significantly modified OS, while rs9288952 tend to be associated with patients' survival.

Conclusion

Our results indicate that BTLA polymorphic variants may be considered low penetrating risk factors for NSCLC especially in never-smokers, and in females, and are associated with OS of NSCLC patients.

Multi-omics analysis reveals a molecular landscape of the early recurrence and early metastasis in pan-cancer

Cancer remains a formidable challenge in medicine due to its propensity for recurrence and metastasis, which can result in unfavorable treatment outcomes. This challenge is particularly acute for early-stage patients, who may experience recurrence and metastasis without timely detection. Here, we first analyzed the differences in clinical characteristics among the primary tumor, recurrent tumor, and metastatic tumor in different stages of cancer, which may be caused by the molecular level. Moreover, the importance of predicting early cancer recurrence and metastasis is emphasized by survival analyses. Next, we used a multi-omics approach to identify key molecular changes associated with early cancer recurrence and metastasis and discovered that early metastasis in cancer demonstrated a high degree of genomic and cellular heterogeneity. We performed statistical comparisons for each level of omics data including gene expression, mutation, copy number variation, immune cell infiltration, and cell status. Then, various analytical techniques, such as proportional hazard model and Fisher's exact test, were used to identify specific genes or immune characteristics associated with early cancer recurrence and metastasis. For example, we observed that the overexpression of BPIFB1 and high initial B-cell infiltration levels are linked to early cancer recurrence, while the overexpression or amplification of ANKRD22 and LIPM, mutation of IGHA1 and MUC16, high fibroblast infiltration level, M1 polarization of macrophages, cellular status of DNA repair are all linked to early cancer metastasis. These findings have led us to construct classifiers, and the average area under the curve (AUC) of these classifiers was greater than 0.75 in The Cancer Genome Atlas (TCGA) cancer patients, confirming that the features we identified could be biomarkers for predicting recurrence and metastasis of early cancer. Finally, we identified specific early sensitive targets for targeted therapy and immune checkpoint inhibitor therapy. Once the biomarkers we identified changed, treatment-sensitive targets can be treated accordingly. Our study has comprehensively characterized the multi-omics characteristics and identified a panel of biomarkers of early cancer recurrence and metastasis. Overall, it provides a valuable resource for cancer recurrence and metastasis research and improves our understanding of the underlying mechanisms driving early cancer recurrence and metastasis.

Markers of local kidney cancer recurrence: A surgeon's mistake or a pattern? Review

The influence of various morphological, anatomical, genetic and other factors on the local recurrence-free survival of patients who have undergone different renal cell cancer (RCC) treatment is still a rather complex, ambiguous and controversial issue for practicing oncourologists. This review evaluates the effect of several factors on both recurrence-free survival and local recurrence-free survival. The review includes articles, clinical cases, literature reviews, and meta-analyses highlighting the analysis of independent and interrelated predisposing factors for developing local recurrence of RCC from 1984 to 2020. The PubMed, Web of Science, and Scopus databases were searched in English, Spanish, and German. A review of the literature showed the role of the following indices in the local recurrence RCC: microvascular invasion (p = 0.001), tumor necrosis (p = 0.0001), high malignancy (Fuhrman III or IV) (HR = 38.3, 95% CI 3.1-467, p = 0.004) as histological factors, tumor size as an anatomical factor. Thus, the authors state that every centimeter of the tumor increases the risk of local recurrence (p < 0.05). A group from the Mayo Clinic showed the equivalence of different treatment methods in local RCC recurrence. Thus, in the group of patients with cT1a stage kidney cancer, the 5-year local recurrence-free survival rates were 97.7% (96.7-98.6), 95.9% (92.3-99.6), and 95.9% (92.3-99.6) for renal resection, RFA, and cryoablation, respectively. Surgical margin status is the most studied and controversial marker of local renal cell carcinoma recurrence. Researchers found a direct effect of PSM on the risk of local RCC recurrence (p < 0.01). The personalized approach with the search and evaluation of predisposing factors for the local recurrence, as well as further selection of the most optimal treatment, will allow oncourologists to improve both the effectiveness of primary treatment and the recurrence-free survival of patients.

Targeting 4-1BB and PD-L1 induces potent and durable antitumor immunity in B-cell lymphoma

Introduction

Although PD-1/L1 mAb has demonstrated clinical benefits in certain cancer types, low response rate and resistance remain the main challenges for the application of these immune checkpoint inhibitors (ICIs). 4-1BB is a co-stimulator molecule expressed in T cells, which could enhance T cell proliferation and activation. Herein, the synergetic antitumor effect and underlying mechanism of 4-1BB agonist combined with PD-1/PD-L1 blockade were determined in B-cell lymphoma (BCL).

Methods

Subcutaneous transplantation BCL tumor models and metastasis models were established to evaluate the therapeutic effect of PD-L1 antibody and/or 4-1BB agonist in vivo. For the mechanistic study, RNA-seq was applied to analyze the tumor microenvironment and immune-related signal pathway after combination treatment. The level of IFN-γ, perforin, and granzyme B were determined by ELISA and Real-time PCR assays, while tumor-infiltrating T cells were measured by flow cytometry and immunohistochemical analysis. CD4/CD8 specific antibodies were employed to deplete the related T cells to investigate the role CD4+ and CD8+ T cells played in combination treatment.

Results

Our results showed that combining anti-PD-L1 ICI and 4-1BB agonists elicited regression of BCL and significantly extended the survival of mice compared to either monotherapy. Co-targeting PD-L1 and 4-1BB preferentially promoted intratumoral cytotoxic lymphocyte infiltration and remodeled their function. RNA-sequence analysis uncovered a series of up-regulated genes related to the activation and proliferation of cytotoxic T lymphocytes, further characterized by increased cytokines including IFN-γ, granzyme B, and perforin. Furthermore, depleting CD8+ T cells not CD4+ T cells totally abrogated the antitumor efficacy, indicating the crucial function of the CD8+ T cell subset in the combination therapy.

Discussion

In summary, our findings demonstrated that 4-1BB agonistic antibody intensified the antitumor immunity of anti-PD-1/PD-L1 ICI via promoting CD8+ T cell infiltration and activation, providing a novel therapeutic strategy to BCL.

Cell Differentiation Trajectory Predicts Prognosis and Immunotherapeutic Response in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the main type of malignancy in kidney related to glucose metabolism. Primary single cell culture and single cell sequencing are novel research technologies. In this study, we explored the differentiation status of ccRCC cells and its significance in prognosis and immunotherapeutic response through bioinformatics. We characterized distinct differentiation states and differentiation-related genes (DRGs) in ccRCC cells through single cell RNA sequencing (scRNA-seq) analysis. Combined with bulk RNA-seq data, we classified patients into two clusters and found that this classification was closely correlated with patient prognosis and immunotherapeutic responses. Based on machine learning, we identified a prognostic risk model composed of 14 DRGs, including BTG2, CDKN1A, COL6A1, CPM, CYB5D2, FOSB, ID2, ISG15, PLCG2, SECISBP2, SOCS3, TES, ZBTB16, and ZNF704, to predict the survival rate of patients and then constructed a nomogram model integrating clinicopathological characteristics and risk score for clinical practice. In the study of immune checkpoints, we found that patients in the high-risk group had a disposition to get worse prognosis and better effects of immune checkpoint blocking therapies. Finally, we found the expression level of model DRGs was associated with a tumor-immune microenvironment (TIME) pattern and the response of 83 compounds or inhibitors was significantly different in the two risk groups. In a word, our study highlights the potential contribution of cell differentiation in prognosis judgment and immunotherapy response and offers promising therapeutic options for ccRCC patients.

Plasma CD27, a Surrogate of the Intratumoral CD27-CD70 Interaction, Correlates with Immunotherapy Resistance in Renal Cell Carcinoma

PURPOSE

CD70 is a costimulatory molecule known to activate CD27-expressing T cells. CD27-CD70 interaction leads to the release of soluble CD27 (sCD27). Clear-cell renal cell carcinoma (ccRCC) expresses the highest levels of CD70 among all solid tumors; however, the clinical consequences of CD70 expression remain unclear.

EXPERIMENTAL DESIGN

Tumor tissue from 25 patients with ccRCC was assessed for the expression of CD27 and CD70 in situ using multiplex immunofluorescence. CD27+ T-cell phenotypes in tumors were analyzed by flow cytometry and their gene expression profile were analyzed by single-cell RNA sequencing then confirmed with public data. Baseline sCD27 was measured in 81 patients with renal cell carcinoma (RCC) treated with immunotherapy (35 for training cohort and 46 for validation cohort).

RESULTS

In the tumor microenvironment, CD27+ T cells interacted with CD70-expressing tumor cells. Compared with CD27- T cells, CD27+ T cells exhibited an apoptotic and dysfunctional signature. In patients with RCC, the intratumoral CD27-CD70 interaction was significantly correlated with the plasma sCD27 concentration. High sCD27 levels predicted poor overall survival in patients with RCC treated with anti-programmed cell death protein 1 in both the training and validation cohorts but not in patients treated with antiangiogenic therapy.

CONCLUSIONS

In conclusion, we demonstrated that sCD27, a surrogate marker of T-cell dysfunction, is a predictive biomarker of resistance to immunotherapy in RCC. Given the frequent expression of CD70 and CD27 in solid tumors, our findings may be extended to other tumors.

The role of immune profile in predicting outcomes in cancer patients treated with immunotherapy

Background

Despite the efficacy of immunotherapy, only a small percentage of patients achieves a long-term benefit in terms of overall survival. The aim of this study was to define an immune profile predicting the response to immune checkpoint inhibitors (ICIs).

Methods

Patients with advanced solid tumors, who underwent ICI treatment were enrolled in this prospective study. Blood samples were collected at the baseline. Thirteen soluble immune checkpoints, 3 soluble adhesion molecules, 5 chemokines and 11 cytokines were analyzed. The results were associated with oncological outcomes.

Results

Regardless of tumor type, patients with values of sTIM3, IFNα, IFNγ, IL1β, IL1α, IL12p70, MIP1β, IL13, sCD28, sGITR, sPDL1, IL10 and TNFα below the median had longer overall survival (p<0.05). By using cluster analysis and grouping the patients according to the trend of the molecules, two clusters were found. Cluster A had a significantly higher mean progression free survival (Cluster A=11.9 months vs Cluster B=3.5 months, p<0.01), a higher percentage of disease stability (Cluster A=34.5% vs. Cluster B=0%, p<0.05) and a lower percentage of disease progression (Cluster A=55.2% vs. Cluster B = 94.4%, p=0.04).

Conclusion

The combined evaluation of soluble molecules, rather than a single circulating factor, may be more suitable to represent the fitness of the immune system status in each patient and could allow to identify two different prognostic and predictive outcome profiles.

Genomic and Immune Approach in Platinum Refractory HPV-Negative Head and Neck Squamous Cell Carcinoma Patients Treated with Immunotherapy: A Novel Combined Profile

Introduction: Only a minority of patients with platinum refractory head and neck squamous cell carcinoma (PR/HNSCC) gain some lasting benefit from immunotherapy. Methods: The combined role of the comprehensive genomic (through the FoundationOne Cdx test) and immune profiles of 10 PR/HNSCC patients treated with the anti-PD-1 nivolumab was evaluated. The immune profiles were studied both at baseline and at the second cycle of immunotherapy, weighing 20 circulating cytokines/chemokines, adhesion molecules, and 14 soluble immune checkpoints dosed through a multiplex assay. A connectivity map was obtained by calculating the Spearman correlation between the expression profiles of circulating molecules. Results: Early progression occurred in five patients, each of them showing TP53 alteration and three of them showing a mutation/loss/amplification of genes involved in the cyclin-dependent kinase pathway. In addition, ERB2 amplification (1 patient), BRCA1 mutation (1 patient), and NOTCH1 genes alteration (3 patients) occurred. Five patients achieved either stable disease or partial response. Four of them carried mutations in PI3K/AKT/PTEN pathways. In the only two patients, with a long response to immunotherapy, the tumor mutational burden (TMB) was high. Moreover, a distinct signature, in terms of network connectivity of the circulating soluble molecules, characterizing responder and non-responder patients, was evidenced. Moreover, a strong negative and statistically significant (p-value ≤ 0.05) correlation with alive status was evidenced for sE-selectin at T1. Conclusions: Our results highlighted the complexity and heterogeneity of HNSCCs, even though it was in a small cohort. Molecular and immune approaches, combined in a single profile, could represent a promising strategy, in the context of precision immunotherapy.

Cellular and soluble immune checkpoint signaling forms PD-L1 and PD-1 in renal tumor tissue and in blood

Immune checkpoint blockade therapy is a treatment option of various metastatic cancer diseases including renal cell carcinoma (RCC). Approved antibody drugs target the co-inhibitory signaling of Programmed Cell Death Ligand-1 (PD-L1) and its receptor Programmed Cell Death-1 (PD-1). The combined evaluation of PD-L1 and PD-1 at the mRNA and protein levels in tumor tissue with differentiation of tumor and immune cells as well as of soluble forms (sPD-L1) and (sPD-1) in blood is of basic interest in assessing biomarker surrogates. Here, we demonstrate that PD-L1 determined as fraction of stained tumor cells (TPS-score) correlates with PD-L1-mRNA in tumor tissue, reflecting the predominant expression of PD-L1 in tumor cells. Conversely, PD-1 in immune cells of tumor tissue (IC-score) correlated with PD-1-mRNA tissue levels reflecting the typical PD-1 expression in immune cells. Of note, sPD-L1 in blood did not correlate with either the TPS-score of PD-L1 or with PD-L1-mRNA in tumor tissue. sPD-L1 released into the supernatant of cultured RCC cells closely followed the cellular PD-L1 expression as tested by interferon γ (IFNG) induction and siRNA knockdown of PD-L1. Further analysis in patients revealed that sPD-L1 significantly increased in blood following renal tumor resection. In addition, sPD-L1 correlated significantly with inflammation marker C-reactive protein (CRP) and with PD-L1 mRNA level in whole blood. These results indicate that the major source of sPD-L1 in blood may be peripheral blood cells and not primarily tumor tissue PD-L1.

TIGIT is the central player in T-cell suppression associated with CAR T-cell relapse in mantle cell lymphoma

BACKGROUND

Chimeric antigen receptor (CAR) T-cell therapy using brexucabtagene autoleucel (BA) induces remission in many patients with mantle cell lymphoma (MCL), and BA is the only CAR T-cell therapy approved by the FDA for MCL. However, development of relapses to BA is recognized with poor patient outcomes. Multiple CAR T-cell therapies have been approved for other lymphomas and the resistance mechanisms have been investigated. However, the mechanisms underlying BA relapse in MCL have not been investigated and whether any previously reported resistance mechanisms apply to BA-relapsed patients with MCL is unknown.

METHODS

To interrogate BA resistance mechanisms in MCL, we performed single-cell RNA sequencing on 39 longitudinally collected samples from 15 BA-treated patients, and multiplex cytokine profiling on 80 serial samples from 20 patients.

RESULTS

We demonstrate that after BA relapse, the proportion of T cells, especially cytotoxic T cells (CTLs), decreased among non-tumor cells, while the proportion of myeloid cells correspondingly increased. TIGIT, LAG3, and CD96 were the predominant checkpoint molecules expressed on exhausted T cells and CTLs; only TIGIT was significantly increased after relapse. CTLs expanded during remission, and then contracted during relapse with upregulated TIGIT expression. Tumor cells also acquired TIGIT expression after relapse, leading to the enhanced interaction of tumor cell TIGIT with monocyte CD155/PVR. In myeloid cells, post-relapse HLA-II expression was reduced relative to pretreatment and during remission. Myeloid-derived suppressor cells (MDSCs) were enriched after relapse with elevated expression of activation markers, including CLU (clusterin) and VCAN (versican). Extracellular chemokines (CCL4, CXCL9, CXCL13), soluble checkpoint inhibitors (sPD-L1, sTIM3, s4-1BB), and soluble receptors (sIL-2R, sTNFRII) were decreased during remission but elevated after relapse.

CONCLUSIONS

Our data demonstrate that multiple tumor-intrinsic and -extrinsic factors are associated with T-cell suppression and BA relapse. Among these, TIGIT appears to be the central player given its elevated expression after BA relapse in not only CTLs but also MCL cells. The acquisition of TIGIT expression on tumor cells is MCL-specific and has not been reported in other CAR T-treated diseases. Together, our data suggest that co-targeting TIGIT may prevent CAR T relapses and thus promote long-term progression-free survival in MCL patients.

The Features of Checkpoint Receptor—Ligand Interaction in Cancer and the Therapeutic Effectiveness of Their Inhibition

To date, certain problems have been identified in cancer immunotherapy using the inhibition of immune checkpoints (ICs). Despite the excellent effect of cancer therapy in some cases when blocking the PD-L1 (programmed death-ligand 1) ligand and the immune cell receptors PD-1 (programmed cell death protein 1) and CTLA4 (cytotoxic T-lymphocyte-associated protein 4) with antibodies, the proportion of patients responding to such therapy is still far from desirable. This situation has stimulated the exploration of additional receptors and ligands as targets for immunotherapy. In our article, based on the analysis of the available data, the TIM-3 (T-cell immunoglobulin and mucin domain-3), LAG-3 (lymphocyte-activation gene 3), TIGIT (T-cell immunoreceptor with Ig and immunoreceptor tyrosine-based inhibitory motif (ITIM) domains), VISTA (V-domain Ig suppressor of T-cell activation), and BTLA (B- and T-lymphocyte attenuator) receptors and their ligands are comprehensively considered. Data on the relationship between receptor expression and the clinical characteristics of tumors are presented and are analyzed together with the results of preclinical and clinical studies on the therapeutic efficacy of their blocking. Such a comprehensive analysis makes it possible to assess the prospects of receptors of this series as targets for anticancer therapy. The expression of the LAG-3 receptor shows the most unambiguous relationship with the clinical characteristics of cancer. Its inhibition is the most effective of the analyzed series in terms of the antitumor response. The expression of TIGIT and BTLA correlates well with clinical characteristics and demonstrates antitumor efficacy in preclinical and clinical studies, which indicates their high promise as targets for anticancer therapy. At the same time, the relationship of VISTA and TIM-3 expression with the clinical characteristics of the tumor is contradictory, and the results on the antitumor effectiveness of their inhibition are inconsistent.

Identification of a Prognostic Model Based on Immune Cell Signatures in Clear Cell Renal Cell Carcinoma

Background. Accumulating evidence substantiated that the immune cells were intricately intertwined with the prognosis and therapy of clear cell renal cell carcinoma (ccRCC). We aimed to construct an immune cell signatures (ICS) score model to predict the prognosis of ccRCC patients and furnish guidance for finding appropriate treatment strategies. Methods. Based on The Cancer Genome Atlas (TCGA) database, the normalized enrichment score (NES) of 184 ICSf was calculated using single-sample gene set enrichment analysis (ssGSEA). An ICS score model was generated in light of univariate Cox regression and Least absolute shrinkage and selection operator (Lasso)-Cox regression, which was independently validated in ArrayExpress database. In addition, we appraised the predictive power of the model via Kaplan-Meier (K-M) curves and time-dependent receiver operating characteristic (ROC) curves. Eventually, immune infiltration, genomic alterations and immunotherapy were analyzed between high and low ICS score groups. Results. Initially, we screened 11 ICS with prognostic impact based on 515 ccRCC patients. K-M curves presented that the high ICS score group experienced a poorer prognosis ( $P<0.001$ ). In parallel, ROC curves revealed a satisfactory reliability of model to predict individual survival at 1, 3, and 5 years, with area under the curves (AUCs) of 0.744, 0.713, and 0.742, respectively. In addition, we revealed that the high ICS score group was characterized by increased infiltration of immune cells, strengthened BAP1 mutation frequency, and enhanced expression of immune checkpoint genes. Conclusion. The ICS score model has higher predictive power for patients’ prognosis and can instruct ccRCC patients in seeking suitable treatment.

The expression and significance of efferocytosis and immune checkpoint related molecules in pancancer samples and the correlation of their expression with anticancer drug sensitivity

Background: The efferocytosis-related molecules have been considered to be correlated with the resistance to cancer chemotherapy. The aim of this study was to investigate the expression and significance of efferocytosis-related molecules in cancers and the correlation of their expression with anticancer drug sensitivity, and provide new potential targets and treatment options for cancers.

Methods: We investigated the differential expression of 15 efferocytosis-related molecules (Axl, Tyro3, MerTK, CX3CL1, Tim-4, BAI1, Stab2, Gas6, IDO1, Rac1, MFGE8, ICAM-1, CD47, CD31, and PD-L1) and other 12 common immune checkpoint-related molecules in tumor and normal tissues, the correlation between their expression and various clinicopathological features in 16 types of cancers using publicly available pancancer datasets in The Cancer Genome Atlas. We also analyzed the correlation of the expression of efferocytosis and immune checkpoint related molecules with 126 types of anticancer drugs sensitivity using drug-RNA-seq data.

Results: There is a panel of circulating molecules among the 27 molecules. Based on the results of differential expression and correlation with various clinicopathological features of efferocytosis-related molecules in cancers, we identified new potential therapeutic targets for anticancer therapy, such as Axl for kidney renal clear cell carcinoma, Tyro3 for liver hepatocellular carcinoma, and IDO1 for renal papillary cell carcinoma. Except for BAI1, CD31, and MerTK, the enhanced expressions of Axl, Tyro3, Gas6, MFGE8, Stab2, Tim-4, CX3CL1, IDO1, Rac1, and PD-L1 were associated with decreased sensitivity of the cancer cells to many anti-cancer drugs; however, for other common immune checkpoint-related molecules, only enhanced expressions of PD-1, CD28, CTLA4, and HVEM were associated with decreased sensitivity of the cancer cells to a few drugs.

Conclusion: The efferocytosis-related molecules were significantly associated with clinical outcomes in many types of cancers and played important roles in resistance to chemotherapy. Combination therapy targeting efferocytosis-related molecules and other immune checkpoint-related molecules is necessary to reduce resistance to chemotherapy.

The Features of Immune Checkpoint Gene Regulation by microRNA in Cancer

Currently, the search for new promising tools of immunotherapy continues. In this regard, microRNAs (miRNAs) that influence immune checkpoint (IC) gene expression in tumor and T-cells and may be important regulators of immune cells are considered. MiRNAs regulate gene expression by blocking mRNA translation. An important feature of miRNA is its ability to affect the expression of several genes simultaneously, which corresponds to the trend toward the use of combination therapy. The article provides a list of miRNAs acting simultaneously on several ICs and miRNAs that, in addition to IC, can regulate the expression of targeted therapy genes. There is dependence of miRNA interactions with IC genes on the type of cancer. The analysis of the accumulated data demonstrates that only about 14% (95% CI: 9.8–20.1%) of the studied miRNAs regulate the expression of specific IC in more than one type of cancer. That is, there is tumor specificity in the miRNA action on ICs. A number of miRNAs demonstrated high efficiency in vitro and in vivo. This indicates the potential of miRNAs as promising agents for cancer immunotherapy. Additional studies of the miRNA–gene interaction features and the search for an optimal miRNA mimic structure are necessary.

Soluble Immune Checkpoint-Related Proteins in Blood Are Associated With Invasion and Progression in Non-Small Cell Lung Cancer

Background

Immune checkpoint inhibition therapy has been achieved significant success in the treatment of non-small cell lung cancer (NSCLC). However, the role of soluble immune checkpoint- related proteins in NSCLC remains obscure.

Methods

We evaluated the circulating levels of 14 immune checkpoint-related proteins panel (BTLA, LAG-3, GITR, IDO, PD-L2, PD-L1, PD-1, HVEM, Tim-3, CD28, CD27, CD80, CD137 and CTLA-4) and their associations with the risk of invasive disease and the risk of NSCLC in 43 pre-invasive (AIS), 81 invasive NSCLC (IAC) patients and matched 35 healthy donors using a multiplex Luminex assay. Gene expression in tumors from TCGA were analyzed to elucidate potential mechanisms. The multivariate logistic regression model was applied in the study. ROC(receiver operator characteristic) curve and calibration curve were used in the performance evaluation.

Results

We found that sCD27, sCD80, CD137 and sPDL2 levels were significantly increased in IAC cases compared to AIS cases (P= 1.05E-06, 4.44E-05, 2.30E-05 and 1.16E-06, respectively), whereas sPDL1 and sPDL2 levels were significantly increased in NSCLC cases compared to healthy controls (P=3.25E-05 and 1.49E-05, respectively). Unconditional univariate logistic regression analysis indicated that increased sCD27, sCD80, sCD137, and sPDL2 were significantly correlated with the risk of invasive diseases. The model with clinical variables, sCD27 and sPDL2 demonstrated the best performance (AUC=0.845) in predicting the risk of IAC. CD27 and PDCD1LG2 (PDL2) showed significant association with cancer invasion signature in TCGA dataset.

Conclusion

Our study provides evidence that soluble immune checkpoint-related proteins may associate with the risk of IAC, and we further established an optimized multivariate predictive model, which highlights their potential application in the treatment of NSCLC patients. Future studies may apply these biomarkers to test their predictive value of survival and treatment outcome during immunotherapy in NSCLC patients.