Immune escape to PD-L1/PD-1 blockade: seven steps to success (or failure)

Immunotherapy plus chemotherapy showed superior clinical benefit to chemotherapy alone in advanced NSCLC patients after progression on osimertinib

BACKGROUND

Osimertinib is the standard first-line treatment for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation. Resistance to osimertinib remains a clinical challenge. However, the optimal therapy for these patients is still controversial. In this study, we aimed to assess the efficacy and safety of immunotherapy plus chemotherapy (IO+C) compared with chemotherapy (C) in NSCLC patients after progression on osimertinib.

METHODS

Advanced NSCLC patients after progression on osimertinib were retrospectively reviewed. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety were evaluated between the patients treated with IO+C and C.

RESULTS

A total of 40 patients were included in the study. There were 20 patients each in the IO+C group or C group. The ORR was significantly higher in patients in the IO+C group (45% vs. 25%, p < 0.01). The median PFS was 6.4 months for patients in the IO+C group compared to 2.8 months for patients in C group (HR: 0.41, 95% confidence interval [CI]: 0.20-0.82, p < 0.01). The median OS was significantly longer in the IO+C group than the C group (OS: 12.8 vs. 10.5 months, HR: 0.39, 95% CI: 0.19-0.80, p < 0.01). In subgroup analysis, patients of both sexes, age ≤ 65, bone or adrenal metastasis, exon19 del mutation, and third-line treatment obtained more OS benefits from immunotherapy. The safety profile of both groups was comparable.

CONCLUSIONS

Our study provides the clinical evidence of favoring immunotherapy plus chemotherapy in NSCLC patients after progression on osimertinib.

Comprehensive Analysis of m6A Regulators Characterized by the Immune Cell Infiltration in Head and Neck Squamous Cell Carcinoma to Aid Immunotherapy and Chemotherapy

Background

N6-Methyladenosine (m⁶A), which is a prevalent regulator of mRNA expression, has gathered increasing study interests. Though the role of m⁶A as being important in many biological processes (such as growth and proliferation of cancers) has been well documented, its potential role in tumor immune microenvironment (TIME) has rarely been analyzed.

Methods

We downloaded RNA expression, single nucleotide polymorphism (SNP), and copy number variation (CNV) data from The Cancer Genome Atlas (TCGA). We then curated 21 m⁶A regulators and clustered patients into three m⁶A subtypes and m⁶A-related gene subtypes and compared them based on overall survival (OS). The combination of CIBERSORT as well as ssGSEA quantified the infiltration levels of immune cells and immune-related functions. The m⁶A scores were determined by using principal component analysis (PCA) algorithm. Furthermore, we evaluate the correlation of m⁶A regulators with immune and response to therapy.

Results

Three m⁶A clusters were identified based on the TCGA-HNSCC cohort, and there were significant associations among them in overall outcomes and caner-related pathways. We found that three m⁶A clusters were consistent with three phenotypes: immune-inflamed, immune-dessert, and immune-excluded. HNSCC patients were divided into high– and low–m⁶A score groups based on the cutoff of m⁶A score. Patients with lower m⁶A score had better overall survival outcome. Further analysis indicated that patients with higher m⁶A score presented higher tumor mutation burden (TMB). In addition, patients in low–m⁶A score subgroup had high chemotherapeutics sensitivity. GEO cohort confirmed patients with low m⁶A score demonstrated significant overall survival advantages and clinical benefits. Low m⁶A score carry an increased neoantigen load, eliciting a response to immunotherapy, and its value in predicting survival outcomes of immunotherapy was also confirmed in three anti-PD-1 cohorts.

Conclusions

Our study demonstrated that m⁶A regulators are closely related to TIME and the m⁶A score was an effective prognostic biomarker and predictive indicator for immunotherapy and chemotherapeutics. Comprehensive evaluation of m⁶A regulators in tumors will extend our understanding of TIME and effectively guide increasing study investigations on immunotherapy and chemotherapy strategies for HNSCC.

Conditional Deletion of Pdcd1 Identifies the Cell-Intrinsic Action of PD-1 on Functional CD8 T Cell Subsets for Antitumor Efficacy

Programmed cell death-1 (PD-1) blockade has a profound effect on the ability of the immune system to eliminate tumors, but many questions remain about the cell types involved and the underlying mechanisms of immune activation. To shed some light on this, the cellular and molecular events following inhibition of PD-1 signaling was investigated in the MC-38 colon carcinoma model using constitutive (PD-1 KO) and conditional (PD1cKO) mice and in wild-type mice treated with PD-1 antibody. The impact on both tumor growth and the development of tumor immunity was assessed. In the PD-1cKO mice, a complete deletion of Pdcd1 in tumor-infiltrating T cells (TILs) after tamoxifen treatment led to the inhibition of tumor growth of both small and large tumors. Extensive immune phenotypic analysis of the TILs by flow and mass cytometry identified 20-different T cell subsets of which specifically 5-CD8 positive ones expanded in all three models after PD-1 blockade. All five subsets expressed granzyme B and interferon gamma (IFNγ). Gene expression analysis of the tumor further supported the phenotypic analysis in both PD-1cKO- and PD-1 Ab-treated mice and showed an upregulation of pathways related to CD4 and CD8 T-cell activation, enhanced signaling through costimulatory molecules and IFNγ, and non-T-cell processes. Altogether, using PD-1cKO mice, we define the intrinsic nature of PD-1 suppression of CD8 T-cell responses in tumor immunity.

Cancer-Immunity Cycle and Therapeutic Interventions- Opportunities for Including Pet Dogs With Cancer

The tumor-immune interplay represents a dynamic series of events executed by cellular and soluble participants that either promote or inhibit successful tumor formation and growth. Throughout a tumor’s development and progression, the host organism’s immune system reacts by generating anti-cancer defenses through various incremental and combinatorial mechanisms, and this reactive orchestration is termed the cancer-immunity cycle. Success or failure of the cancer-immunity cycle dictates the fate of both host and tumor as winner or loser. Insights into how the tumor and host immune system continuously adapt to each other throughout the lifecycle of the tumor is necessary to rationally develop new effective immunotherapies. Additionally, the evolving nature of the cancer-immunity cycle necessitates therapeutic agility, requiring real-time serial assessment of immunobiologic markers that permits tailoring of therapies to the everchanging tumor immune microenvironment. In order to accelerate advances in the field of immuno-oncology, this review summarizes the steps comprising the cancer-immunity cycle, and underscores key breakpoints in the cycle that either favor cancer regression or progression, as well as shaping of the tumor microenvironment and associated immune phenotypes. Furthermore, specific large animal models of spontaneous cancers that are deemed immunogenic will be reviewed and proposed as unique resources for validating investigational immunotherapeutic protocols that are informed by the cancer-immunity cycle. Collectively, this review will provide a progressive look into the dynamic interplay between tumor and host immune responses and raise awareness for how large animal models can be included for developing combinatorial and sequenced immunotherapies to maximizing favorable treatment outcomes.

The Emerging Interplay Between Recirculating and Tissue-Resident Memory T Cells in Cancer Immunity: Lessons Learned From PD-1/PD-L1 Blockade Therapy and Remaining Gaps

Remarkable progress has been made in the field of anti-tumor immunity, nevertheless many questions are still open. Thus, even though memory T cells have been implicated in long-term anti-tumor protection, particularly in prevention of cancer recurrence, the bases of their variable effectiveness in tumor patients are poorly understood. Two types of memory T cells have been described according to their traffic pathways: recirculating and tissue-resident memory T cells. Recirculating tumor-specific memory T cells are found in the cell infiltrate of solid tumors, in the lymph and in the peripheral blood, and they constantly migrate in and out of lymph nodes, spleen, and bone marrow. Tissue-resident tumor-specific memory T cells (TRM) permanently reside in the tumor, providing local protection. Anti-PD-1/PD-L1, a type of immune checkpoint blockade (ICB) therapy, can considerably re-invigorate T cell response and lead to successful tumor control, even in patients at advanced stages. Indeed, ICB has led to unprecedented successes against many types of cancers, starting a ground-breaking revolution in tumor therapy. Unfortunately, not all patients are responsive to such treatment, thus further improvements are urgently needed. The mechanisms underlying resistance to ICB are still largely unknown. A better knowledge of the dynamics of the immune response driven by the two types of memory T cells before and after anti-PD-1/PD-L1 would provide important insights on the variability of the outcomes. This would be instrumental to design new treatments to overcome resistance. Here we provide an overview of T cell contribution to immunity against solid tumors, focusing on memory T cells. We summarize recent evidence on the involvement of recirculating memory T cells and TRM in anti-PD-1/PD-L1-elicited antitumor immunity, outline the open questions in the field, and propose that a synergic action of the two types of memory T cells is required to achieve a full response. We argue that a T-centric vision focused on the specific roles and the possible interplay between TRM and recirculating memory T cells will lead to a better understanding of anti-PD-1/PD-L1 mechanism of action, and provide new tools for improving ICB therapeutic strategy.

Endocannabinoid System and Tumour Microenvironment: New Intertwined Connections for Anticancer Approaches

The tumour microenvironment (TME) is now recognised as a hallmark of cancer, since tumour:stroma crosstalk supports the key steps of tumour growth and progression. The dynamic co-evolution of the tumour and stromal compartments may alter the surrounding microenvironment, including the composition in metabolites and signalling mediators. A growing number of evidence reports the involvement of the endocannabinoid system (ECS) in cancer. ECS is composed by a complex network of ligands, receptors, and enzymes, which act in synergy and contribute to several physiological but also pathological processes. Several in vitro and in vivo evidence show that ECS deregulation in cancer cells affects proliferation, migration, invasion, apoptosis, and metastatic potential. Although it is still an evolving research, recent experimental evidence also suggests that ECS can modulate the functional behaviour of several components of the TME, above all the immune cells, endothelial cells and stromal components. However, the role of ECS in the tumour:stroma interplay remains unclear and research in this area is particularly intriguing. This review aims to shed light on the latest relevant findings of the tumour response to ECS modulation, encouraging a more in-depth analysis in this field. Novel discoveries could be promising for novel anti-tumour approaches, targeting the microenvironmental components and the supportive tumour:stroma crosstalk, thereby hindering tumour development.

Emerging biomarkers in metastatic urothelial carcinoma: tumour mutational burden, PD-L1 expression and APOBEC polypeptide-like signature in a patient with complete response to anti-programmed cell death protein-1 inhibitor

Immunotherapy has recently been incorporated into the treatment guidelines for metastatic urothelial carcinoma. Nevertheless, the role of prognostic and predictive biomarkers in this setting is not completely defined. To date, PD-L1 expression and a high tumour mutational burden (TMB) seem to predict better responses to immune checkpoint inhibitors, but patients without these biomarkers may still respond to immunotherapy. There are some caveats regarding these biomarkers, such as lack of standardisation of techniques, tumour heterogeneity and other factors influencing the tumour microenvironment. Genomic signatures are other promising emerging strategies. We hereby discuss the management of a 70-year-old man with a metastatic recurrence of urothelial carcinoma within 1 year after neoadjuvant chemotherapy and radical cystectomy. Tumour next-generation sequencing showed a high TMB and a CD274 (PD-L1) amplification. The patient was treated with pembrolizumab and achieved a complete response.

Turning tumors from cold to inflamed to improve immunotherapy response

Immune checkpoint inhibitors have revolutionized the treatment landscape for a number of cancers over the last few decades. Nevertheless, a majority of patients still do not benefit from these treatments. Such patient-specific lack of response can be predicted, in part, from the immune phenotypes present in the tumor microenvironment. We provide a perspective on options to reprogram the tumors and their microenvironment to increase the therapeutic efficacy of immunotherapies and expand their efficacy against cold tumors. Additionally, we review data from current preclinical and clinical trials aimed at testing the different therapeutic options in monotherapy or preferably in combination with checkpoint inhibitors.

Immunotherapeutic Advances for NSCLC

Immunotherapy with antibodies against PD-1 or PD-L1, either alone or in combination with chemotherapy, has revolutionized treatment paradigms of non-small cell lung cancer (NSCLC) patients without oncogenic driver alterations. These agents, namely immune checkpoint inhibitors (ICIs), have also widely demonstrated a remarkable efficacy in locally advanced as well as in early-stage NSCLC. Assessment of tumor PD-L1 expression by immunohistochemistry has entered into routine clinical practice to select patients for immunotherapy, even though its predictive role has long been debated. Despite improved survival outcomes over standard chemotherapy, treatment with ICIs is associated with initial low response rate, with a significant proportion of patients not responding to these agents. Hence, novel appealing predictive biomarkers, such as those related to tumor cell signaling pathways, metabolism or the tumor microenvironment, have emerged as potentially useful to select those patients most likely to benefit from immunotherapy. Moreover, most patients ultimately develop acquired resistance to ICI treatment over time and novel therapeutic strategies are urgently needed to overcome or delay resistance. Herein, we provide an overview on recent advances in immunotherapy in NSCLC, focusing on updated results from studies on ICIs in different disease settings and at different lines of treatment. We further describe currently emerging predictive biomarkers, beyond PD-L1, to optimize patient selection and novel strategies to improve clinical outcomes.

M6A Classification Combined With Tumor Microenvironment Immune Characteristics Analysis of Bladder Cancer

Background

Studies have shown that N6-methyl adenosine (m6A) plays an important role in cancer progression; however, the underlying mechanism of m6A modification in tumor microenvironment (TME) cell infiltration of bladder cancer remains unclear. This study aimed to investigate the role of m6A modification in TME cell infiltration of bladder cancer.

Methods

The RNA expression profile and clinical data of bladder cancer were obtained from The Cancer Genome Atlas and Gene Expression Omnibus. We assessed the m6A modification patterns of 664 bladder cancer samples based on 20 m6A regulators through unsupervised clustering analysis and systematically linked m6A modification patterns to TME cell infiltration characteristics. Gene ontology and gene set variation analyses were conducted to analyze the underlying mechanism based on the assessment of m6A methylation regulators. Principal component analysis was used to construct the m6A score to quantify m6A modification patterns of bladder cancer.

Results

The genetic and expression alterations in m6A regulators were highly heterogeneous between normal and bladder tissues. Three m6A modification patterns were identified. The cell infiltration characteristics were highly consistent with the three immune phenotypes, including immune rejection, immune inflammation, and immune desert. The biological functions of three m6A modification patterns were different. Cox regression analyses revealed that the m6A score was an independent signature with patient prognosis (HR = 1.198, 95% CI: 1.031-1.390). Patients with a low-m6A score were characterized by increased tumor mutation burden, PD-L1 expression, and poorer survival. Patients in the low-m6A score group also showed significant immune responses and clinical benefits in the CTLA-4 immunotherapy cohort (p =0.0069).

Conclusions

The m6A methylation modification was related to the formation of TME heterogeneity and complexity. Assessing the m6A modification pattern of individual bladder cancer will improve the understanding of TME infiltration characteristics.

Preclinical Characterization of GLS-010 (Zimberelimab), a Novel Fully Human Anti-PD-1 Therapeutic Monoclonal Antibody for Cancer

Background

Zimberelimab (GLS-010) is a novel fully human monoclonal immunoglobulin G4 (IgG4) against the programmed cell death-1 (PD-1) receptor.

Aim

To evaluate the affinity, competitive blocking capability, T cell activation effect, cytotoxic effector functions by Fc, preliminary anti-tumor activity, and pharmacokinetics of GLS-010.

Methods

The affinity of GLS-010 to PD-1 and the ability of GLS-010 to block the PD-L1/2 to PD-1 interaction on the cell surface were measured. An allogeneic mixed lymphocyte reaction was conducted to evaluate the inhibitory effect of GLS-010 on Tregs and stimulatory effect on T cell proliferation and activation. Pharmacodynamics and pharmacokinetics were evaluated in tumor-bearing mice and cynomolgus monkeys, respectively.

Results

The equilibrium dissociation constant (KD) for the association between GLS-010 and PD-1 was 1.75×10^-10 M. GLS-010 could effectively block the binding of PD-L1/2 to PD-1. GLS-010 showed statistically significant anti-tumor effects in the MC38 model in human PD-1 knock-in mice. The RO rate on in the low-, moderate-, and high-dose groups were 64.50%-48.53% in CD3⁺T, 58.87%-40.12% in CD8⁺T, and 66.26%-49.07% in CD4⁺T, respectively. With the increasing dose from 2 mg/kg to 18 mg/kg, the systemic exposure level of GLS-010 (AUC_0-last) and C₀ increased proportionally, while the proportion of AUC_0-last was higher than the proportion of the increase in the dose.

Conclusions

As a fully human anti-PD-1 monoclonal antibody, GLS-010 has a high affinity to PD-1 and shows potent anti-tumor effects in vivo and in vitro. The results support that GLS-010 could be investigated in clinical trials in tumor patients.

Characterization of hypoxia response patterns identified prognosis and immunotherapy response in bladder cancer

Intra-tumoral hypoxia and immunity are highly correlated with prognosis of tumor patients. Nonetheless, no studies have reported a systematic analysis of the relationship between hypoxia response and immunity in bladder cancer (BLCA). In this study, we comprehensively evaluated the hypoxia response patterns and their association with genomic and clinicopathological characteristics of 1,343 BLCA patients using unsupervised consensus clustering. Five hypoxia response patterns were defined, and the HPXscore was constructed using least absolute shrinkage and selection operator (LASSO)-Cox regression algorithms to represent the individual hypoxia response pattern. The low HPXscore group was characterized by immune activation and high DNA damage repair, which was referred to the immune-inflamed phenotype. However, activation of stromal-related pathways was observed in the high HPXscore group, which is recognized as T cell suppressive and more likely to be an immune-excluded phenotype. Furthermore, the HPXscore was an independent prognostic factor and could act as a good predictor for immunotherapeutic outcomes in BLCA. Thus, depicting a comprehensive landscape of the hypoxia characteristics may therefore help us to interpret the underlying mechanism of immune escape and shed light on the clinical application of hypoxia modification and immune checkpoints targeting immunotherapies for BLCA.

FDG PET biomarkers for prediction of survival in metastatic melanoma prior to anti-PD1 immunotherapy

Our aim was to analyse whether biomarkers extracted from baseline ¹⁸F-FDG PET before anti-PD1 treatment contribute to prognostic survival information for early risk stratification in metastatic melanoma. Fifty-six patients, without prior systemic treatment, BRAF wild type, explored using ¹⁸F-FDG PET were included retrospectively. Our primary endpoint was overall survival (OS). Total metabolic tumoral volume (MTV) and forty-one IBSI compliant parameters were extracted from PET. Parameters associated with outcome were evaluated by a cox regression model and when significant helped build a prognostic score. Median follow-up was 22.1 months and 21 patients died. Total MTV and long zone emphasis (LZE) correlated with shorter OS and served to define three risk categories for the prognostic score. For low, intermediate and high risk groups, survival rates were respectively 91.1% (IC 95 80–1), 56.1% (IC 95 37.1–85) and 19% (IC 95 0.06–60.2) and hazard ratios were respectively 0.11 (IC 95 0.025–0.46), P = 0.0028, 1.2 (IC 95 0.48–2.8), P = 0.74 and 5.9 (IC 95 2.5–14), P < 0.0001. To conclude, a prognostic score based on total MTV and LZE separated metastatic melanoma patients in 3 categories with dramatically different outcomes. Innovative therapies should be tested in the group with the lowest prognosis score for future clinical trials.

Combination therapy for hepatocellular carcinoma with diacylglycerol kinase alpha inhibition and anti-programmed cell death-1 ligand blockade

Activation of diacylglycerol kinase alpha (DGKα) augments proliferation and suppresses apoptosis of cancer cells and induces T lymphocyte anergy. We investigated the dual effects of DGKα inhibition on tumorigenesis and anti-tumor immunity with the aim of establishing a novel therapeutic strategy for cancer. We examined the effects of a DGKα inhibitor (DGKAI) on liver cancer cell proliferation and cytokine production by immune cells in vitro and on tumorigenesis and host immunity in a hepatocellular carcinoma (HCC) mouse model. Oral DGKAI significantly suppressed tumor growth and prolonged survival in model mice. Tumor infiltration of T cells and dendritic cells was also enhanced in mice treated with DGKAI, and the production of cytokines and cytotoxic molecules by CD4⁺ and CD8⁺ T cells was increased. Depletion of CD8⁺ T cells reduced the effect of DGKAI. Furthermore, interferon-γ stimulation augmented the expression of programmed cell death-1 ligand (PD-L1) on cancer cells, and DGKAI plus an anti-PD-L1 antibody strongly suppressed the tumor growth. These results suggest that DGKα inhibition may be a promising new treatment strategy for HCC.

m6A regulator-mediated methylation modification patterns and tumor microenvironment infiltration characterization in hepatocellular carcinoma

Background: There is increasing evidence of the epigenetic regulation of the immune response in cancer. However, the specific functions and mechanisms of RNA N6-methyladenosine (m6A) modification in the cell infiltration in the hepatocellular carcinoma (HCC) tumor microenvironment (TME) is unknown.

Methods: We systematically analyzed the m6A-modification patterns of 371 HCC samples based on 23 m6A regulators, and determined their correlation with TME cell-infiltrating characteristics. Principal-component analysis algorithms was used to calculate the m6Ascore and clarify the m6A-modification patterns of individual tumors.

Results: Three different m6A-modification patterns were identified in HCC, wherein the m6Acluster B and m6Acluster A had the best and worst prognosis, respectively. These three patterns had different TME cell infiltration characteristics and biological behavior. An m6A-scoring signature was constructed to evaluate the m6A-modification patterns within individual tumors. A low m6Ascore was associated with a low overall survival and high clinical stage. Moreover, the m6A-scoring signature was characterized by distinct immunotherapeutic landscapes; a high m6A score indicated a higher immune checkpoint inhibitor score in the anti-PD-1 treatment alone, anti-CTLA-4 treatment alone, or combined anti-CTLA-4/PD-1 treatment cohorts, which reflected significant treatment and clinical benefits.

Conclusions: Our study highlights the significant role of the m6A modification in the HCC TME. A scoring signature to clarify the individual m6A-modification pattern would help us understand the HCC TME infiltration characterization and, thus, would guide the selection of more effective immunotherapeutic strategies.

Strategies to Overcome Failures in T-Cell Immunotherapies by Targeting PI3K-δ and -γ

PI3K-δ and PI3K-γ are critical regulators of T-cell differentiation, senescence, and metabolism. PI3K-δ and PI3K-γ signaling can contribute to T-cell inhibition via intrinsic mechanisms and regulation of suppressor cell populations, including regulatory T-cells and myeloid derived suppressor cells in the tumor. We examine an exciting new role for using selective inhibitors of the PI3K δ- and γ-isoforms as modulators of T-cell phenotype and function in immunotherapy. Herein we review the current literature on the implications of PI3K-δ and -γ inhibition in T-cell biology, discuss existing challenges in adoptive T-cell therapies and checkpoint blockade inhibitors, and highlight ongoing efforts and future directions to incorporate PI3K-δ and PI3K-γ as synergistic T-cell modulators in immunotherapy.

PTENα functions as an immune suppressor and promotes immune resistance in PTEN-mutant cancer

PTEN is frequently mutated in human cancers and PTEN mutants promote tumor progression and metastasis. PTEN mutations have been implicated in immune regulation, however, the underlying mechanism is largely unknown. Here, we report that PTENα, the isoform of PTEN, remains active in cancer bearing stop-gained PTEN mutations. Through counteraction of CD8⁺ T cell-mediated cytotoxicity, PTENα leads to T cell dysfunction and accelerates immune-resistant cancer progression. Clinical analysis further uncovers that PTENα-active mutations suppress host immune responses and result in poor prognosis in cancer as relative to PTENα-inactive mutations. Furthermore, germline deletion of Ptenα in mice increases cell susceptibility to immune attack through augmenting stress granule formation and limiting synthesis of peroxidases, leading to massive oxidative cell death and severe inflammatory damage. We propose that PTENα protects tumor from T cell killing and thus PTENα is a potential target in antitumor immunotherapy.

PTENα is an N-terminally extended isoform of PTEN, a gene frequently mutated in human cancers. Here the authors show that PTENα remains active in PTEN-mutant cancers and is associated with tumor immune escape by promoting tumor cell resistance to T cell cytotoxicity.

Inhibition of STAT3/PD-L1 and Activation of miR193a-5p Are Critically Involved in Apoptotic Effect of Compound K in Prostate Cancer Cells

Since the signal transducer and activator of transcription 3 (STAT3)/programmed death-ligand 1 (PD-L1) signaling plays an important role in tumor-immune microenvironments, in the present study, the role of STAT3/PD-L1 signaling in the apoptotic mechanism of an active ginseng saponin metabolite compound K (CK) was investigated in human prostate cancer cells. Here, CK exerted significant cytotoxicity without hurting RWPE1 normal prostate epithelial cells, increased sub-G1 and cleavage of Poly ADP-ribose polymerase (PARP) and attenuated the expression of pro-PARP and Pro-cysteine aspartyl-specific protease3 (pro-caspase-3) in LANCap, PC-3 and DU145 cells. Further, CK attenuated the expression of p-STAT3 and PD-L1 in DU145 cells along with disrupted the binding of STAT3 to PD-L1. Furthermore, CK effectively abrogated the expression of p-STAT3 and PD-L1 in interferon-gamma (INF-γ)-stimulated DU145cells. Additionally, CK suppressed the expression of vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), interleukin 6 (IL-6) and interleukin 10 (IL-10) as immune escape-related genes in DU145 cells. Likewise, as STAT3 targets genes, the expression of CyclinD1, c-Myc and B-cell lymphoma-extra-large (Bcl-xL) was attenuated in CK-treated DU145 cells. Notably, CK upregulated the expression of microRNA193a-5p (miR193a-5p) in DU145 cells. Consistently, miR193a-5p mimic suppressed p-STAT3, PD-L1 and pro-PARP, while miR193a-5p inhibitor reversed the ability of CK to attenuate the expression of p-STAT3, PD-L1 and pro-PARP in DU145 cells. Taken together, these findings support evidence that CK induces apoptosis via the activation of miR193a-5p and inhibition of PD-L1 and STAT3 signaling in prostate cancer cells.

Targeting USP22 with miR‑30‑5p to inhibit the hypoxia‑induced expression of PD‑L1 in lung adenocarcinoma cells

Lung cancer is one of the most common forms of cancer and accounts for a significant proportion of all cancer‑related deaths. Lung adenocarcinoma (LUAD) accounts for approximately 40% of all cases of lung cancer. In recent years, new developments in both the diagnosis and treatment of LUAD have been achieved. Unfortunately, the prognosis remains poor for patients with malignant LUAD. Hypoxia is a common characteristic of solid tumors and induce the immune evasion by increasing the expression of programmed cell death‑ligand‑1 (PD‑L1) in the tumor. In this study, it was predicted that ubiquitin‑specific peptidase 22 (USP22) is the direct target of the microRNA (miR)‑30‑5p family, including miR‑30a‑5p, miR‑30b‑5p, miR‑30c‑5p, miR‑30d‑5p and miR‑30e‑5p. Furthermore, the binding of USP22 with the miR‑30‑5p family was confirmed by luciferase assay. In addition, it was demonstrated that targeting USP22 via the miR‑30‑5p family inhibited the induction of PD‑L1 expression in hypoxic conditions, thus preventing activated T cells from killing LUAD cells. Our results indicated that miR‑30a‑5p, miR‑30b‑5p, miR‑30c‑5p, miR‑30d‑5p and miR‑30e‑5p represent new targets for the treatment of LUAD.

Toward personalized treatment approaches for non-small-cell lung cancer

Worldwide, lung cancer is the most common cause of cancer-related deaths. Molecular targeted therapies and immunotherapies for non-small-cell lung cancer (NSCLC) have improved outcomes markedly over the past two decades. However, the vast majority of advanced NSCLCs become resistant to current treatments and eventually progress. In this Perspective, we discuss some of the recent breakthrough therapies developed for NSCLC, focusing on immunotherapies and targeted therapies. We highlight our current understanding of mechanisms of resistance and the importance of incorporating genomic analyses into clinical studies to decipher these further. We underscore the future role of neoadjuvant and maintenance combination therapy approaches to potentially cure early disease. A major challenge to successful development of rational combination therapies will be the application of robust predictive biomarkers for clear-cut patient stratification, and we provide our views on clinical research areas that could influence how NSCLC will be managed over the coming decade.

LC3B upregulation by NANOG promotes immune resistance and stem-like property through hyperactivation of EGFR signaling in immune-refractory tumor cells

Immune selection drives tumor cells to acquire refractory phenotypes. We previously demonstrated that cytotoxic T lymphocyte (CTL)-mediated immune pressure enriches NANOG+ tumor cells with stem-like and immune-refractory properties that make them resistant to CTLs. Here, we report that the emergence of refractory phenotypes is highly associated with an aberrant macroautophagic/autophagic state of the NANOG+ tumor cells and that the autophagic phenotype arises through transcriptional induction of MAP1LC3B/LC3B by NANOG. Furthermore, we found that upregulation of LC3B expression contributes to an increase in EGF secretion. The subsequent hyperactivation of EGFR-AKT signaling rendered NANOG+ tumor cells resistant to CTL killing. The NANOG-LC3B-p-EGFR axis was preserved across various types of human cancer and correlated negatively with the overall survival of cervical cancer patients. Inhibition of LC3B in immune-refractory tumor models rendered tumors susceptible to adoptive T-cell transfer, as well as PDCD1/PD-1 blockade, and led to successful, long-term control of the disease. Thus, our findings demonstrate a novel link among immune-resistance, stem-like phenotypes, and LC3B-mediated autophagic secretion in immune-refractory tumor cells, and implicate the LC3B-p-EGFR axis as a central molecular target for controlling NANOG+ immune-refractory cancer.Abbreviations: ACTB: actin beta; ATG7: autophagy related 7; BafA1: bafilomycin A1; CASP3: caspase 3; CFSE: carboxyfluorescein succinimidyl ester; ChIP: chromatin immunoprecipitation; CI: confidence interval; CIN: cervical intraepithelial neoplasia; CSC: cancer stem cell; CTL: cytotoxic T lymphocyte; EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; FIGO: International Federation of Gynecology and Obstetrics; GFP: green fluorescent protein; GZMB: granzyme B; HG-CIN: high-grade CIN; IHC: immunohistochemistry; LG-CIN: low-grade CIN; LN: lymph node; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCL1: myeloid cell leukemia sequence 1; MLANA/MART-1: melanoma antigen recognized by T cells 1; MUT: mutant; NANOG: Nanog homeobox; PDCD1/PD-1: programmed cell death 1; PMEL/gp100: premelanosome protein; RTK: receptor tyrosine kinase; TMA: tissue microarray; WT: wild type.

ST8Sia6 Promotes Tumor Growth in Mice by Inhibiting Immune Responses

Many tumors exhibit increased incorporation of sialic acids into cell-surface glycans, which impact the tumor microenvironment. Sialic acid immunoglobulin-like lectins (Siglec) are receptors that recognize sialic acids and modulate immune responses, including responses to tumors. However, the roles of individual sialyltransferases in tumorigenesis and tumor growth are not well understood. Here, we examined the sialyltransferase ST8Sia6, which generated α2,8-linked disialic acids that bind to murine Siglec-E and human Siglec-7 and -9. Increased ST8Sia6 expression was found on many human tumors and associated with decreased survival in several cancers, including colon cancer. Because of this, we engineered MC38 and B16-F10 tumor lines to express ST8Sia6. ST8Sia6-expressing MC38 and B16-F10 tumors exhibited faster growth and led to decreased survival, which required host Siglec-E. ST8Sia6 expression on tumors also altered macrophage polarization toward M2, including upregulation of the immune modulator arginase, which also required Siglec-E. ST8Sia6 also accelerated tumorigenesis in a genetically engineered, spontaneous murine model of colon cancer, decreasing survival from approximately 6 months to 67 days. Thus, ST8Sia6 expression on tumors inhibits antitumor immune responses to accelerate tumor growth.

Banxia xiexin decoction affects drug sensitivity in gastric cancer cells by regulating MGMT expression via IL‑6/JAK/STAT3‑mediated PD‑L1 activity

Banxia xiexin decoction (BXXX) is a classic preparation used to treat gastrointestinal diseases, and also has certain therapeutic effects on gastrointestinal tumors. BXXX has been reported to regulate the expression of proteins associated with drug resistance and sensitivity in tumors, and thus, the aim of the present study was to investigate the mechanisms of BXXX drug sensitivity in gastric cancer (GC). The expression levels of programmed cell death 1 ligand 1 (PD‑L1), 6‑O‑methylguanine‑DNA methyltransferase (MGMT) and STAT3 were immunohistochemically detected in the cancer and adjacent non‑cancer tissues of patients with GC, and in vitro experimentation was conducted using drug‑resistant and ‑sensitive GC cells. The expression levels of PD‑L1, MGMT and STAT3 were determined using reverse transcription‑quantitative PCR. Different concentrations of BXXX drug serum were used to treat the cells and the cellular inhibition rate was assessed using a Cell Counting Kit‑8 assay. Flow cytometry was used to detect apoptosis, and western blot analysis was used to detect the expression levels of IL‑6, IFN‑γ, JAK/STAT3 pathway proteins, PD‑L1 and MGMT. The association between PD‑L1 and MGMT protein expression levels was subsequently assessed via co‑immunoprecipitation. Furthermore, in vivo studies were conducted following the establishment of a drug‑resistant tumor‑bearing mouse model, where GC tumor size was assessed under different treatment conditions, and western blot analysis was used to detect the expression of related pathway proteins. The expression levels of PD‑L1, MGMT and STAT3 were significantly increased in GC tissues, GC cells and cisplatin‑resistant cells. Furthermore, BXXX inhibited the proliferation of drug‑resistant cells and promoted the inhibitory effects of chemotherapeutic drugs on drug‑resistant cells. BXXX also inhibited the expression levels of IL‑6, IFN‑γ and JAK/STAT3 pathway proteins, as well as the expression levels of PD‑L1 and MGMT. Colivelin, an activator of STAT3, reversed the effects of BXXX on drug‑resistant GC cells, and significantly reversed the effect of BXXX on PD‑L1 expression. In conclusion, BXXX was found to influence the drug sensitivity of GC cells by regulating the expression of MGMT. This process functions viaPD‑L1, which was itself mediated by IL‑6/JAK/STAT3 signaling.

Liver Injury and Use of Contrast-Enhanced Ultrasound for Evaluating Intrahepatic Recurrence in a Case of TACE-Refractory Hepatocellular Carcinoma Receiving Atezolizumab-Bevacizumab Combination Therapy: A Case Report

A 67-year-old male with type 2 diabetes (T2DM) was diagnosed with postoperative intrahepatic recurrence for hepatocellular carcinoma (HCC). Nine sessions of transarterial chemoembolization (TACE) proved ineffective, and the patient was diagnosed as having TACE-refractory disease and received seven cycles of atezolizumab-bevacizumab combination therapy. After that, the patient developed hyperglycemia with the HbA1c elevation and the marked fasting serum C-peptide reduction and was diagnosed with developed immune-mediated diabetes (IMD) (T2DM exacerbation with insulin-dependent diabetes development). Subsequently, the hepatobiliary enzyme levels, which were high before the systemic therapy, worsened. Thus, we clinically diagnosed an exacerbation of liver injury due to TACE-induced liver injury complicated by drug-induced liver injury such as immune-mediated hepatotoxicity (IMH). Meanwhile, after contrast-enhanced computed tomography revealed complete response, contrast-enhanced ultrasound was performed to assess intrahepatic recurrence. We found that the latter modality allowed earlier and more definitive diagnosis of intrahepatic recurrence of HCC. Subsequently, despite systemic therapy discontinuation and steroids administration, the liver injury worsened, and the patient died. The autopsy revealed intrahepatic recurrence of HCC and extensive arterial obstruction by the beads used for TACE within the liver, which indicated that disturbed circulation was the primary cause of the liver injury and histopathologically confirmed IMD, but not IMH.

Combination Therapy of Mithramycin A and Immune Checkpoint Inhibitor for the Treatment of Colorectal Cancer in an Orthotopic Murine Model

The axis of Programmed cell death-1 receptor (PD-1) with its ligand (PD-L1) plays a critical role in colorectal cancer (CRC) in escaping immune surveillance, and blocking this axis has been found to be effective in a subset of patients. Although blocking PD-L1 has been shown to be effective in 5-10% of patients, the majority of the cohorts show resistance to this checkpoint blockade (CB) therapy. Multiple factors assist in the growth of resistance to CB, among which T cell exhaustion and immunosuppressive effects of immune cells in the tumor microenvironment (TME) play a critical role along with other tumor intrinsic factors. We have previously shown the polyketide antibiotic, Mithramycin-A (Mit-A), an effective agent in killing cancer stem cells (CSCs) in vitro and in vivo in a subcutaneous murine model. Since TME plays a pivotal role in CB therapy, we tested the immunomodulatory efficacy of Mit-A with anti-PD-L1 mAb (αPD-L1) combination therapy in an immunocompetent MC38 syngeneic orthotopic CRC mouse model. Tumors and spleens were analyzed by flow cytometry for the distinct immune cell populations affected by the treatment, in addition to RT-PCR for tumor samples. We demonstrated the combination treatment decreases tumor growth, thus increasing the effectiveness of the CB. Mit-A in the presence of αPD-L1 significantly increased CD8+ T cell infiltration and decreased immunosuppressive granulocytic myeloid-derived suppressor cells and anti-inflammatory macrophages in the TME. Our results revealed Mit-A in combination with αPD-L1 has the potential for augmented CB therapy by turning an immunologically "cold" into "hot" TME in CRC.

Multiplexed single-cell pathology reveals the association of CD8 T-cell heterogeneity with prognostic outcomes in renal cell carcinoma

Despite the high sensitivity of renal cell carcinoma (RCC) to immunotherapy, RCC has been recognized as an unusual disease in which CD8⁺ T-cell infiltration into the tumor beds is related to a poor prognosis. To approach the inner landscape of immunobiology of RCC, we performed multiplexed seven-color immunohistochemistry (CD8, CD39, PD-1, Foxp3, PD-L1, and pan-cytokeratin AE1/AE3 with DAPI), which revealed the automated single-cell counts and calculations of individual cell-to-cell distances. In total, 186 subjects were included, in which CD39 was used as a marker for distinguishing tumor-specific (CD39⁺) and bystander (CD39^-) T-cells. Our clear cell RCC cohort also revealed a poor prognosis if the tumor showed increased CD8⁺ T-cell infiltration. Intratumoral CD8⁺CD39⁺ T-cells as well as their exhausted CD8⁺CD39⁺PD-1⁺ T-cells in the central tumor areas enabled the subgrouping of patients according to malignancy. Analysis using specimens post-antiangiogenic treatment revealed a dramatic increase in proliferative Treg fraction Foxp3⁺PD-1⁺ cells, suggesting a potential mechanism of hyperprogressive disease after uses of anti-PD-1 antibody. Our cell-by-cell study platform provided spatial information on tumors, where bystander CD8⁺CD39^- T-cells were dominant in the invasive margin areas. We uncovered a potential interaction between CD8⁺CD39⁺PD-1⁺ T-cells and Foxp3⁺PD-1⁺ Treg cells due to cell-to-cell proximity, forming a spatial niche more specialized in immunosuppression under PD-1 blockade. A paradigm shift to the immunosuppressive environment was more obvious in metastatic lesions; rather the infiltration of Foxp3⁺ and Foxp3⁺PD-1⁺ Treg cells was more pronounced. With this multiplexed single-cell pathology technique, we revealed further insight into the immunobiological standing of RCC.

Atezolizumab: A Review in Extensive-Stage SCLC

Atezolizumab (Tecentriq^®), a fully humanized, monoclonal anti-programmed cell death ligand-1 (PD-L1) antibody, is the first immune checkpoint inhibitor to be approved, in combination with carboplatin and etoposide, for the treatment of adult patients with extensive-stage small cell lung cancer (ES-SCLC). Approval was based on primary data from the multinational phase I/III IMpower133 trial in PD-L1-unselected patients with previously untreated ES-SCLC. In this trial, induction therapy with atezolizumab plus carboplatin and etoposide followed by maintenance therapy with atezolizumab alone significantly prolonged overall survival (OS) and progression-free survival (PFS) compared with carboplatin and etoposide alone. The addition of atezolizumab to chemotherapy was generally well tolerated, with no new safety signals being identified beyond those previously reported for the individual agents. The most common grade 3-4 treatment-related adverse events with this regimen were haematological; the most common immune-related adverse events included rash and hypothyroidism. Importantly, the addition of atezolizumab to chemotherapy improved survival outcomes without adversely impacting patient-reported health-related quality of life (HRQOL). Thus, atezolizumab in combination with carboplatin plus etoposide has emerged as a valuable option for the first-line treatment of ES-SCLC and is being accepted as a standard of care in this setting.

Comprehensive Analysis of Peritoneal Metastasis Sequencing Data to Identify LINC00924 as a Prognostic Biomarker in Gastric Cancer

Background

Gastric cancer peritoneal metastasis has high mortality. At present, there is no effective way to cure the patients diagnosed with gastric cancer peritoneal metastasis due to its indistinct molecular mechanism. Therefore, to understand the pathogenesis and help for further target therapy, we conduct comprehensive analysis of peritoneal metastasis by bioinformatics in gastric cancer.

Methods

Microarray sequencing was used to find differential mRNAs and long non-coding RNAs (lncRNAs) expression between primary foci and peritoneal metastases lesion in gastric cancer. RT-qPCR was used to verify the expression levels of lncRNAs in gastric cancer cells after co-culture with adipocytes. TCGA, Cytoscape, lnCAR, cBioPoratal and R packages (ggrisk, survival, survminer, timeROC, forestplot, immunedeconv, ggplot2, pheatmap and ggpubr) were applied in this work.

Results

Adipocytes co-culture model was used to mimic the peritoneal microenvironment and found that LINC01151 (NR_126348), FAM27B (NR_027422) and LINC00924 (NR_027133) were up-regulated in co-culture group. Increased LINC00924 expression was significantly associated with reduced overall survival and up-regulated percentage abundance of tumor-infiltrating CD8⁺ T, B, macrophage and NK immune cells; moreover, immune checkpoint blockers (ICBs) had a worse effect on the LINC00924 high expression group. Furthermore, through univariate and multivariate Cox regression analysis, we found that LINC00924-related PEX5L in CNC network was an independent prognostic factor in gastric cancer progression.

Conclusion

LINC00924 expression was associated with poor survival, immune infiltrations and worse response to ICBs. LINC00924 might be immunotherapeutic targets of advanced gastric cancer.

Identification and Validation of Immune-Related LncRNA Prognostic Signature for Lung Adenocarcinoma

This study aimed to establish a prognostic risk model for lung adenocarcinoma (LUAD). We firstly divided 535 LUAD samples in TCGA-LUAD into high-, medium-, and low-immune infiltration groups by consensus clustering analysis according to immunological competence assessment by single-sample gene set enrichment analysis (ssGSEA). Profile of long non-coding RNAs (lncRNAs) in normal samples and LUAD samples in TCGA was used for a differential expression analysis in the high- and low-immune infiltration groups. A total of 1,570 immune-related differential lncRNAs in LUAD were obtained by intersecting the above results. Afterward, univariate COX regression analysis and multivariate stepwise COX regression analysis were conducted to screen prognosis-related lncRNAs, and an eight-immune-related-lncRNA prognostic signature was finally acquired (AL365181.2, AC012213.4, DRAIC, MRGPRG-AS1, AP002478.1, AC092168.2, FAM30A, and LINC02412). Kaplan–Meier analysis and ROC analysis indicated that the eight-lncRNA-based model was accurate to predict the prognosis of LUAD patients. Simultaneously, univariate COX regression analysis and multivariate COX regression analysis were undertaken on clinical features and risk scores. It was illustrated that the risk score was a prognostic factor independent from clinical features. Moreover, immune data of LUAD in the TIMER database were analyzed. The eight-immune-related-lncRNA prognostic signature was related to the infiltration of B cells, CD4+ T cells, and dendritic cells. GSEA enrichment analysis revealed significant differences in high- and low-risk groups in pathways like pentose phosphate pathway, ubiquitin mediated proteolysis, and P53 signaling pathway. This study helps to treat LUAD patients and explore molecules related to LUAD immune infiltration to deeply understand the specific mechanism.

STING agonist loaded lipid nanoparticles overcome anti-PD-1 resistance in melanoma lung metastasis via NK cell activation

Background

Resistance to an immune checkpoint inhibitor (ICI) is a major obstacle in cancer immunotherapy. The causes of ICI resistance include major histocompatibility complex (MHC)/histocompatibility locus antigen (HLA) class I loss, neoantigen loss, and incomplete antigen presentation. Elimination by natural killer (NK) cells would be expected to be an effective strategy for the treatment of these ICI-resistant tumors. We previously demonstrated that a lipid nanoparticle containing a stimulator of an interferon gene (STING) agonist (STING-LNP) efficiently induced antitumor activity via the activation of NK cells. Thus, we evaluated the potential of reducing ICI resistance by STING-LNPs.

Methods

Lung metastasis of a B16-F10 mouse melanoma was used as an anti-programmed cell death 1 (anti-PD-1)-resistant mouse model. The mice were intravenously injected with the STING-LNP and the mechanism responsible for the improvement of anti-PD-1 resistance by the STING-LNPs was analyzed by RT-qPCR and flow cytometry. The dynamics of STING-LNP were also investigated.

Results

Although anti-PD-1 monotherapy failed to induce an antitumor effect, the combination of the STING-LNP and anti-PD-1 exerted a synergistic antitumor effect. Our results indicate that the STING-LNP treatment significantly increased the expression of CD3, CD4, NK1.1, PD-1 and interferon (IFN)-γ in lung metastases. This change appears to be initiated by the type I IFN produced by liver macrophages that contain the internalized STING-LNPs, leading to the systemic activation of NK cells that express PD-1. The activated NK cells appeared to produce IFN-γ, resulting in an increase in the expression of the PD ligand 1 (PD-L1) in cancer cells, thus leading to a synergistic antitumor effect when anti-PD-1 is administered.

Conclusions

We provide a demonstration to show that a STING-LNP treatment can overcome PD-1 resistance in a B16-F10 lung metastasis model. The mechanism responsible for this indicates that NK cells are activated by stimulating the STING pathway which, in turn, induced the expression of PD-L1 on cancer cells. Based on the findings reported herein, the STING-LNP represents a promising candidate for use in combination therapy with anti-PD-1-resistant tumors.

Bintrafusp Alfa, a Bifunctional Fusion Protein Targeting TGF-β and PD-L1, in Patients with Esophageal Adenocarcinoma: Results from a Phase 1 Cohort

BACKGROUND

Esophageal adenocarcinoma patients have limited treatment options. TGF-β can be upregulated in esophageal adenocarcinoma, and blocking this pathway may enhance clinical response to PD-(L)1 inhibitors. Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII receptor (a TGF-β "trap") fused to a human IgG1 mAb blocking PD-L1.

OBJECTIVE

The objective of this study was to investigate the efficacy and safety of bintrafusp alfa in patients with advanced, post-platinum esophageal adenocarcinoma, unselected for PD-L1 expression.

PATIENTS AND METHODS

In this phase 1 study, patients with post-platinum, PD-L1-unselected esophageal adenocarcinoma received bintrafusp alfa 1200 mg every 2 weeks until disease progression, unacceptable toxicity, or withdrawal. The primary endpoint was confirmed best overall response per RECIST 1.1 by independent review committee (IRC).

RESULTS

By the database cutoff of 24 August 2018, 30 patients (80.0% had two or more prior anticancer regimens) received bintrafusp alfa for a median of 6.1 weeks. The confirmed objective response rate (ORR) per IRC was 20.0% (95% CI 7.7-38.6); responses lasted 1.3-8.3 months. Most responses (83.3%) occurred in tumors with an immune-excluded phenotype. Investigator-assessed confirmed ORR was 13.3% (95% CI 3.8-30.7). Nineteen patients (63.3%) had treatment-related adverse events: seven patients (23.3%) had grade 3 events; no grade 4 events or treatment-related deaths occurred.

CONCLUSIONS

Bintrafusp alfa showed signs of clinical efficacy with a manageable safety profile in patients with heavily pretreated, advanced esophageal adenocarcinoma.

CLINICAL TRIALS REGISTRATION

NCT02517398.

Bintrafusp Alfa, a Bifunctional Fusion Protein Targeting TGFβ and PD-L1, in Patients with Esophageal Squamous Cell Carcinoma: Results from a Phase 1 Cohort in Asia

BACKGROUND

Patients with esophageal squamous cell carcinoma (SCC) have limited treatment options. Blocking transforming growth factor-β (TGFβ), which can be overexpressed in these tumors, may enhance responses to programmed cell death protein 1/programmed death-ligand 1 [PD-(L)1] inhibitors. Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGFβ receptor II (TGFβRII) (a TGFβ "trap") fused to a human IgG1 monoclonal antibody blocking PD-L1.

OBJECTIVE

The objective of this study was to investigate the safety and efficacy of bintrafusp alfa in Asian patients with pretreated, PD-L1-unselected esophageal SCC.

PATIENTS AND METHODS

In a phase 1 study, Asian patients with pretreated esophageal SCC received bintrafusp alfa 1200 mg every 2 weeks until disease progression, unacceptable toxicity, or withdrawal. The primary endpoint was safety/tolerability with a goal of exploring clinical activity.

RESULTS

By the database cutoff of August 24, 2018, 30 patients (76.7% had two or more prior anticancer regimens) received bintrafusp alfa for a median of 6.1 weeks; two remained on treatment. Nineteen patients (63.3%) had treatment-related adverse events, seven (23.3%) with grade 3/4 events, and there were no treatment-related deaths. The confirmed objective response rate (ORR) per independent review was 10.0% (95% confidence interval [CI] 2.1-26.5); responses lasted 2.8-8.3 + months. All responses occurred in immune-excluded tumors. Investigator-assessed confirmed ORR was 20.0% (95% CI 7.7-38.6). Median overall survival was 11.9 months (95% CI 5.7-not reached).

CONCLUSIONS

Bintrafusp alfa demonstrated a manageable safety profile and efficacy in Asian patients with pretreated esophageal SCC.

CLINICAL TRIALS REGISTRATION

NCT02699515.

Immune-Related Adverse Events as Clinical Biomarkers in Patients with Metastatic Renal Cell Carcinoma Treated with Immune Checkpoint Inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are an important treatment for metastatic renal cell carcinoma (mRCC). These agents may cause immune-related adverse events (irAEs), and the relationship between irAEs and outcomes is poorly understood. We investigated the association between irAEs and clinical outcomes in patients with mRCC treated with ICIs.

METHODS

We performed a retrospective study of 200 patients with mRCC treated with ICIs at Winship Cancer Institute from 2015 to 2020. Data on irAEs were collected from clinic notes and laboratory values and grades were determined using Common Terminology Criteria in Adverse Events version 5.0. The association with overall survival (OS) and progression-free survival (PFS) was modeled by Cox proportional hazards model. Logistic regression models were used to define odds ratios (ORs) for clinical benefit (CB). Landmark analysis and extended Cox models were used to mitigate lead-time bias by treating irAEs as a time-varying covariate.

RESULTS

Most patients (71.0%) were male, and one-third of patients (33.0%) experienced at least one irAE, most commonly involving the endocrine glands (13.0%), gastrointestinal tract (10.5%), or skin (10.0%). Patients who experienced irAEs had significantly longer OS (hazard ratio [HR], 0.52; p = .013), higher chance of CB (OR, 2.10; p = .023) and showed a trend toward longer PFS (HR, 0.71; p = .065) in multivariate analysis. Patients who had endocrine irAEs, particularly thyroid irAEs, had significantly longer OS and PFS and higher chance of CB. In a 14-week landmark analysis, irAEs were significantly associated with prolonged OS (p = .045). Patients who experienced irAEs had significantly longer median OS (44.5 vs. 18.2 months, p = .005) and PFS (7.5 vs. 3.6 months, p = .003) without landmark compared with patients who did not.

CONCLUSION

We found that patients with mRCC treated with ICIs who experienced irAEs, particularly thyroid irAEs, had significantly improved clinical outcomes compared with patients who did not have irAEs. This suggests that irAEs may be effective clinical biomarkers in patients with mRCC treated with ICIs. Future prospective studies are warranted to validate these findings.

IMPLICATIONS FOR PRACTICE

This study found that early onset immune-related adverse events (irAEs) are associated with significantly improved clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors (ICIs). In this site-specific irAE analysis, endocrine irAEs, particularly thyroid irAEs, were significantly associated with improved clinical outcomes. These results have implications for practicing medical oncologists given the increasing use of ICIs for the treatment of mRCC. Importantly, these results suggest that early irAEs and thyroid irAEs at any time on treatment with ICIs may be clinical biomarkers of clinical outcomes in patients with mRCC treated with ICIs.

Metabolic regulation in the immune response to cancer

Metabolic reprogramming in tumor‐immune interactions is emerging as a key factor affecting pro‐inflammatory carcinogenic effects and anticancer immune responses. Therefore, dysregulated metabolites and their regulators affect both cancer progression and therapeutic response. Here, we describe the molecular mechanisms through which microenvironmental, systemic, and microbial metabolites potentially influence the host immune response to mediate malignant progression and therapeutic intervention. We summarized the primary interplaying factors that constitute metabolism, immunological reactions, and cancer with a focus on mechanistic aspects. Finally, we discussed the possibility of metabolic interventions at multiple levels to enhance the efficacy of immunotherapeutic and conventional approaches for future anticancer treatments.

Long non-coding RNA MEG3 mediates the miR-149-3p/FOXP3 axis by reducing p53 ubiquitination to exert a suppressive effect on regulatory T cell differentiation and immune escape in esophageal cancer

Background

Long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) has been implicated in the progression of esophageal cancer (EC). However, the specific mechanism of the involvement of MEG3 in EC development in relation to the regulation of immune escape remains uncertain. Thus, the aim of the current study was to investigate the effect of MEG3 on EC via microRNA-149-3p (miR-149-3p).

Methods

Gain- and loss-of-function experiments were initially performed in EC cells in addition to the establishment of a 4-nitroquinoline 1-oxide-induced EC mouse model aimed at evaluating the respective roles of forkhead box P3 (FOXP3), MEG3, miR-149-3p, mouse double minute 2 homolog (MDM2) and p53 in T cell differentiation and immune escape observed in EC.

Results

EC tissues were found to exhibit upregulated FOXP3 and MDM2 while MEG3, p53 and miR-149-3p were all downregulated. FOXP3 was confirmed to be a target gene of miR-149-3p with our data suggesting it reduced p53 ubiquitination and degradation by means of inhibiting MDM2. P53 was enriched in the promoter of miR-149-3p to upregulate miR-149-3p. The overexpression of MEG3, p53 or miR-149-3p or silencing FOXP3 was associated with a decline in CD25⁺FOXP3⁺CD4⁺ T cells, IL-10⁺CD4⁺ T cells and IL-4⁺CD4⁺ T cells in spleen tissues, IL-4, and IL-10 levels as well as C-myc, N-myc and Ki-67 expression in EC mice.

Conclusion

Collectively, MEG3 decreased FOXP3 expression and resulted in repressed regulatory T cell differentiation and immune escape in EC mice by upregulating miR-149-3p via MDM2-mediated p53.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02907-1.

Classification of Non-Small Cell Lung Cancer's Tumor Immune Micro-Environment and Strategies to Augment Its Response to Immune Checkpoint Blockade

Simple Summary

Immune checkpoint blockade (ICB) has become a major treatment for lung cancer. Better understanding of the tumor immune micro-environment (TIME) in non-small cell lung cancer (NSCLC) is urgently needed to better treat it with this type of therapy. In this review, we describe and explore how NSCLC’s TIME relates to response to ICB, as well as how to treat those with unresponsive types of TIME, which will significantly impact future research in lung cancer immunotherapy.

Abstract

Immune checkpoint blockade (ICB) with checkpoint inhibitors has led to significant and durable response in a subset of patients with advanced stage EGFR and ALK wild-type non-small cell lung cancer (NSCLC). This has been consistently shown to be correlated with the unique characteristics of each patient’s tumor immune micro-environment (TIME), including the composition and distribution of the tumor immune cell infiltrate; the expression of various checkpoints by tumor and immune cells, such as PD-L1; and the presence of various cytokines and chemokines. In this review, the classification of various types of TIME that are present in NSCLC and their correlation with response to ICB in NSCLC are discussed. This is conducted with a focus on the characteristics and identifiable biomarkers of different TIME subtypes that may also be used to predict NSCLC’s clinical response to ICB. Finally, treatment strategies to augment response to ICB in NSCLC with unresponsive types of TIME are explored.

Applications of single-cell sequencing in cancer research: progress and perspectives

Single-cell sequencing, including genomics, transcriptomics, epigenomics, proteomics and metabolomics sequencing, is a powerful tool to decipher the cellular and molecular landscape at a single-cell resolution, unlike bulk sequencing, which provides averaged data. The use of single-cell sequencing in cancer research has revolutionized our understanding of the biological characteristics and dynamics within cancer lesions. In this review, we summarize emerging single-cell sequencing technologies and recent cancer research progress obtained by single-cell sequencing, including information related to the landscapes of malignant cells and immune cells, tumor heterogeneity, circulating tumor cells and the underlying mechanisms of tumor biological behaviors. Overall, the prospects of single-cell sequencing in facilitating diagnosis, targeted therapy and prognostic prediction among a spectrum of tumors are bright. In the near future, advances in single-cell sequencing will undoubtedly improve our understanding of the biological characteristics of tumors and highlight potential precise therapeutic targets for patients.

Intrahepatic cholangiocarcinoma: MRI texture signature as predictive biomarkers of immunophenotyping and survival

OBJECTIVE

Clinical evidence suggests that the response to immune checkpoint blockade depends on the immune status in the tumor microenvironment. This study aims to predict the immunophenotyping (IP) and overall survival (OS) of intrahepatic cholangiocarcinoma (ICC) patients using preoperative magnetic resonance imaging (MRI) texture analysis.

METHODS

A total of 78 ICC patients were included and divided into inflamed (n = 26) or non-inflamed (n = 52) immunophenotyping based on the density of CD8⁺ T cells. The enhanced T1-weighted MRI in the arterial phase was employed with texture analysis. The logistic regression analysis was applied to select the significant features related to IP. The OS-related feature was determined by Cox proportional-hazards model and Kaplan-Meier analysis. IP and OS predictive models were developed using the selected features, respectively.

RESULTS

Three wavelets and one 3D feature have favorable ability to discriminate IP, a combination of which performed best with an AUC of 0.919. The inflamed immunophenotyping had a better prognosis than the non-inflamed one. The 5-year survival rates of the two groups were 48.5% and 25.3%, respectively (p < 0.05). The only wavelet-HLH_firstorder_Median feature was associated with OS and used to build the OS predictive model with a C-index of 0.70 (95% CI, 0.57, 0.82), which could well stratify ICC patients into high- and low-risk groups. The 1-, 3-, and 5-year survival probabilities of the stratified groups were 62.5%, 30.0%, and 24.2%, and 89.5%, 62.2%, and 42.1%, respectively (p < 0.05).

CONCLUSION

The MRI texture signature could serve as a potential predictive biomarker for the IP and OS of ICC patients.

KEY POINTS

• The MRI texture signature, including three wavelets and one 3D feature, showed significant associations with immunophenotyping of ICC, and all have favorable ability to discriminate immunophenotyping; a combination of the above features performed best with an AUC of 0.919. • The only wavelet-HLH_firstorder_Median feature was associated with the OS of ICC and used to build the OS predictive model, which could well stratify ICC patients into high- and low-risk groups.

Role of CD8+ T lymphocyte cells: Interplay with stromal cells in tumor microenvironment

CD8+ T lymphocytes are pivotal cells in the host response to antitumor immunity. Tumor-driven microenvironments provide the conditions necessary for regulating infiltrating CD8+ T cells in favor of tumor survival, including weakening CD8+ T cell activation, driving tumor cells to impair immune attack, and recruiting other cells to reprogram the immune milieu. Also in tumor microenvironment, stromal cells exert immunosuppressive skills to avoid CD8+ T cell cytotoxicity. In this review, we explore the universal function and fate decision of infiltrated CD8+ T cells and highlight their antitumor response within various stromal architectures in the process of confronting neoantigen-specific tumor cells. Thus, this review provides a foundation for the development of antitumor therapy based on CD8+ T lymphocyte manipulation.

One dimensional magneto-optical nanocomplex from silver nanoclusters and magnetite nanorods containing ordered mesocages for sensitive detection of PD-L1

Programmed death ligand 1 (PD-L1) is a typical immune checkpoint protein, whose up-regulation on the membrane of different tumor cells inhibits the immune response of T cells and leads to the escape of tumor cells. In this work, we designed a facile and highly specific surface plasmon resonance (SPR) biosensor to detect PD-L1 in human plasma based on magnetite nanorods containing ordered mesocages (MNOM) and silver nanoclusters (AgNCs). Magneto-optical nanocomplex MNOM@AgNCs with superior magneto-optical properties and high signal-to-noise ratio were fabricated to improve the detection sensitivity owing to the high specific surface area of MNOM and excellent localized SPR of AgNCs. The PD-L1 Antibody on the surface of gold chip and the PD-L1 aptamer on MNOM@AgNCs could realize dual selective recognition of PD-L1, providing the specificity of the sensor and reducing non-specific binding. The SPR sensor showed a good linear range of PD-L1 from 10 ng/mL to 300 ng/mL with the detection limit of 3.29 ng/mL. The practical performance of this immunosensing platform had been successfully verified by clinical samples which included healthy donors and cancer patients. Based on the analysis, the developed immunosensor provided a new strategy for point-of-care detection of PD-L1 and could be used as clinical companion diagnosis of PD-1/PD-L1 inhibitor therapy.

Comparison of SP142 and 22C3 Immunohistochemistry PD-L1 Assays for Clinical Efficacy of Atezolizumab in Non-Small Cell Lung Cancer: Results From the Randomized OAK Trial

BACKGROUND

This phase III OAK trial (NCT02008227) subgroup analysis (data cutoff, January 9, 2019) evaluated the predictive value of 2 PD-L1 IHC tests (VENTANA SP142 and Dako 22C3) for benefit from atezolizumab versus docetaxel by programmed death ligand 1 (PD-L1) status in patients with previously treated metastatic non-small cell lung cancer.

METHODS

PD-L1 expression was assessed prospectively with SP142 on tumor cells (TC) and tumor-infiltrating immune cells (IC) and retrospectively with 22C3 using a tumor proportion score (TPS) based on TC membrane staining. Efficacy was assessed in the 22C3 biomarker-evaluable population (22C3-BEP) (n = 577; 47.1% of SP142-intention-to-treat population) and non-22C3-BEP (n = 648) in PD-L1 subgroups (high, low, and negative) and according to selection by 1 or both assays.

RESULTS

In the 22C3-BEP, overall survival benefits with atezolizumab versus docetaxel were observed across PD-L1 subgroups; benefits were greatest in SP142-defined PD-L1-high (TC3 or IC3: hazard ratio [HR], 0.39 [95% confidence interval (CI), 0.25-0.63]) and 22C3-defined PD-L1-high (TPS ≥ 50%: HR, 0.56 [95% CI, 0.38-0.82]) and low (TPS, 1% to < 50%: HR, 0.55 [95% CI, 0.37-0.82]) groups. Progression-free survival improved with increasing PD-L1 expression for both assays. SP142 and 22C3 assays identified overlapping and unique patient populations in PD-L1-high, positive, and negative subgroups. Overall survival and progression-free survival benefits favored atezolizumab over docetaxel in double PD-L1-positive and negative groups; patients with both SP142- and 22C3-positive tumors derived the greatest benefit.

CONCLUSIONS

Despite different scoring algorithms and differing sensitivity levels, the SP142 and 22C3 assays similarly predicted atezolizumab benefit at validated PD-L1 thresholds in patients with non-small cell lung cancer.

Immunotherapy in Treating EGFR-Mutant Lung Cancer: Current Challenges and New Strategies

Lung cancer is the leading cause of cancer-related deaths worldwide. Immune checkpoint inhibitors, including monoclonal antibodies against programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1), have dramatically improved the survival and quality of life of a subset of non-small cell lung cancer (NSCLC) patients. Multiple predictive biomarkers have been proposed to select the patients who may benefit from the immune checkpoint inhibitors. EGFR-mutant NSCLC is the most prevalent molecular subtype in Asian lung cancer patients. However, patients with EGFR-mutant NSCLC show poor response to anti-PD-1/PD-L1 treatment. While small-molecule EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for EGFR-mutant NSCLC, acquired drug resistance is severely limiting the long-term efficacy. However, there is currently no further effective treatment option for TKIs-refractory EGFR-mutant NSCLC patients. The reasons mediating the poor response of EGFR-mutated NSCLC patients to immunotherapy are not clear. Initial investigations revealed that EGFR-mutated NSCLC has lower PD-L1 expression and a low tumor mutational burden, thus leading to weak immunogenicity. Moreover, the use of PD-1/PD-L1 blockade prior to or concurrent with osimertinib has been reported to increase the risk of pulmonary toxicity. Furthermore, emerging evidence shows that PD-1/PD-L1 blockade in NSCLC patients can lead to hyperprogressive disease associated with dismal prognosis. However, it is difficult to predict the treatment toxicity. New biomarkers are urgently needed to predict response and toxicity associated with the use of PD-1/PD-L1 immunotherapy in EGFR-mutated NSCLC. Recently, promising data have emerged to suggest the potentiation of PD-1/PD-L1 blockade therapy by anti-angiogenic agents and a few other novel therapeutic agents. This article reviews the current investigations about the poor response of EGFR-mutated NSCLC to anti-PD-1/PD-L1 therapy, and discusses the new strategies that may be adopted in the future.

CD24 Contributes to Treatment Effect in ABC-DLBCL Patients with R-CHOP Resistance

Purpose

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma and of which the prognosis of activated B-cell-like (ABC) subtype is poor. Although R-CHOP significantly improves the survival of patients with DLBCL, 20% to 40% of patients were resistant to R-CHOP therapy. Thus, screening for candidate therapeutic targets for R-CHOP resistant patients is urgent. The previous researches have shown that CD24 is related to the development, invasion, and metastasis of cancer. Our project aims to clarify the relationship between CD24 and ABC-DLBCL.

Patients and Methods

The expression of CD24 mRNA in 118 ABC-DLBCL cases treated with R-CHOP was detected by RNAscope, and the relationship between CD24 expression and R-CHOP treatment response was analyzed. The correlation between CD24 expression and treatment efficiency was further analyzed by data downloaded from the Gene Expression Omnibus (GEO) database. The association between CD24 expression and immune response was conducted using Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts (CIBERSORT) methodology and Gene Ontology (GO) biological process (BP) analysis.

Results

The positive expression rate of CD24 mRNA in ABC-DLBCL patients was 38.1% (45/118). Complete Response (CR) rate was significantly higher in patients with CD24 high expression than those with CD24 low expression (P=0.039; 44.4% vs 26.0%). CR rate was significantly different between CD24 high and low expression groups in the analysis of GEO datasets (P=0.003; 83.2% vs 58.0%). The CD24 high expression patients had significantly lower proportions of T cells and nonspecific immune cells in the CIBERSORT analysis. In addition, T-helper 2 cell differentiation and monocyte chemotaxis were repressed in CD24 high expression group in the GO BP analysis.

Conclusion

CD24 was correlated with better R-CHOP treatment response and tumor immunosuppression in ABC-DLBCL. CD24 may be a promising signal in treatment and prognosis evaluation in ABC-DLBCL patients.

PD-1/PD-L1 immune checkpoints: Tumor vs atherosclerotic progression

Immunotherapy has become one of the most attraction cancer therapy strategies. The PD-1/PD-L1 pathway plays key roles in immune responses and autoimmunity by regulating T cell activity. Overactivation of this pathway dampens T cell and immune function, which allows tumor cells immune escape. Antibody or inhibitors of PD-1/PD-L1 immune targets have been implicated in clinic anti-cancer therapy and gain great clinic outcoming for their high efficiency. However, recent studies showed that the PD-1/PD-L1 immunotherapy in some tumor patients was found to accelerate T cell-driven inflammatory and the progression of atherosclerotic lesions. This article reviews the research progression of PD-1/PD-L1 in tumors and atherosclerosis, and the possible mechanisms of anti-PD-1/PD-L1 immunotherapy increasing the risk of atherosclerotic lesions.

Prognostic role of proliferating CD8+ cytotoxic Tcells in human cancers

PURPOSE

Expansion of CD8⁺ cytotoxic Tlymphocytes is a prerequisite for anti-cancer immune activity and has gained interest in the era of immune checkpoint therapy.

METHODS

To understand the CD8⁺ T cell dynamics in the tumor microenvironment, we used multiplex fluorescence immunohistochemistry to quantitate CD8⁺ proliferation (Ki67 co-expression) in tissue microarrays from 1107 colorectal, 642 renal cell, 1066 breast, 375 ovarian, 451 pancreatic and 347 gastric cancer samples.

RESULTS

The density and the percentage of proliferating (Ki67⁺) CD8⁺ T cells were both highly variable between tumor types as well as between patients with the same tumor type. Elevated density and percentage of proliferating CD8⁺ cytotoxic T cells were significantly associated with favorable tumor parameters such as low tumor stage, negative nodal stage (p ≤ 0.0041 each), prolonged overall survival (p ≤ 0.0028 each) and an inflamed immune phenotype (p = 0.0025) in colorectal cancer and, in contrast, linked to high tumor stage, advanced ISUP/Fuhrman/Thoenes grading (each p ≤ 0.003), shorter overall survival (p ≤ 0.0330 each) and an immune inflamed phenotype (p = 0.0094) in renal cell cancer. In breast, ovarian, pancreatic and gastric cancer the role of (Ki67⁺)CD8⁺ Tcells was not linked to clinicopathological data.

CONCLUSION

Our data demonstrate a tumor type dependent prognostic impact of proliferating (Ki67⁺)CD8⁺ Tcells and an inverse impact in colorectal and renal cell cancer.

Find the Flame: Predictive Biomarkers for Immunotherapy in Melanoma

Immunotherapy has revolutionized the therapeutic landscape of melanoma. In particular, checkpoint inhibition has shown to increase long-term outcome, and, in some cases, it can be virtually curative. However, the absence of clinically validated predictive biomarkers is one of the major causes of unpredictable efficacy of immunotherapy. Indeed, the availability of predictive biomarkers could allow a better stratification of patients, suggesting which type of drugs should be used in a certain clinical context and guiding clinicians in escalating or de-escalating therapy. However, the difficulty in obtaining clinically useful predictive biomarkers reflects the deep complexity of tumor biology. Biomarkers can be classified as tumor-intrinsic biomarkers, microenvironment biomarkers, and systemic biomarkers. Herein we review the available literature to classify and describe predictive biomarkers for checkpoint inhibition in melanoma with the aim of helping clinicians in the decision-making process. We also performed a meta-analysis on the predictive value of PDL-1.

Investigating Mechanisms of Response or Resistance to Immune Checkpoint Inhibitors by Analyzing Cell-Cell Communications in Tumors Before and After Programmed Cell Death-1 (PD-1) Targeted Therapy: An Integrative Analysis Using Single-cell RNA and Bulk-RNA Sequencing Data

Currently, a significant proportion of cancer patients do not benefit from programmed cell death-1 (PD-1)-targeted therapy. Overcoming drug resistance remains a challenge. In this study, single-cell RNA sequencing and bulk RNA sequencing data from samples collected before and after anti-PD-1 therapy were analyzed. Cell-cell interaction analyses were performed to determine the differences between pretreatment responders and nonresponders and the relative differences in changes from pretreatment to posttreatment status between responders and nonresponders to ultimately investigate the specific mechanisms underlying response and resistance to anti-PD-1 therapy. Bulk-RNA sequencing data were used to validate our results. Furthermore, we analyzed the evolutionary trajectory of ligands/receptors in specific cell types in responders and nonresponders. Based on pretreatment data from responders and nonresponders, we identified several different cell-cell interactions, like WNT5A-PTPRK, EGFR-AREG, AXL-GAS6 and ACKR3-CXCL12. Furthermore, relative differences in the changes from pretreatment to posttreatment status between responders and nonresponders existed in SELE-PSGL-1, CXCR3-CCL19, CCL4-SLC7A1, CXCL12-CXCR3, EGFR-AREG, THBS1-a3b1 complex, TNF-TNFRSF1A, TNF-FAS and TNFSF10-TNFRSF10D interactions. In trajectory analyses of tumor-specific exhausted CD8 T cells using ligand/receptor genes, we identified a cluster of T cells that presented a distinct pattern of ligand/receptor expression. They highly expressed suppressive genes like HAVCR2 and KLRC1, cytotoxic genes like GZMB and FASLG and the tissue-residence-related gene CCL5. These cells had increased expression of survival-related and tissue-residence-related genes, like heat shock protein genes and the interleukin-7 receptor (IL-7R), CACYBP and IFITM3 genes, after anti-PD-1 therapy. These results reveal the mechanisms underlying anti-PD-1 therapy response and offer abundant clues for potential strategies to improve immunotherapy.

CD2+ T-helper 17-like cells differentiated from a CD133+ subpopulation of non-small cell lung carcinoma cells promote the growth of lung carcinoma

Background

Cancer stem cells (CSCs) give rise to a diverse variety of differentiated cells, which comprise the bulk of the tumor microenvironment (TME). However, the exact multi-directional differentiation potential of CSCs has not been fully clarified. This study was designed to explore whether CSCs differentiate into cellular components of the TME to promote the growth of lung carcinoma.

Methods

The present of CD133⁺, CD2⁺, and CD133⁺CD2⁺ cells in both clinical lung adenocarcinoma tissue and non-small cell lung carcinoma (NSCLC) cell lines were monitored using polymerase chain reaction (PCR) Array, flow cytometry (FCM), quantitative real-time PCR (qRT-PCR) and immunohistofluorescence (IF). Stem-like properties of CD133⁺ cells and CD2⁺ cells were detected by sphere formation assay, IF, and western blot. Colony formation and xenograft tumors experiments were performed to assess the malignant behaviors of CD2⁺ cells. The differentiation of CD133⁺ cells to CD2⁺ Th17-like cells was observed by FCM. The interleukin (IL)-2/phosphorylated signal transducer and activator of transcription protein 5 (pSTAT5)/retinoic acid receptor-related orphan receptor gamma t (RORγt) signaling pathway was evaluated by western blot and FCM.

Results

We found that CD133⁺ cells within both clinical lung adenocarcinoma tissue and NSCLC cell lines included a subset of CD2-expressing cells, which were correlated with the grade of malignancy (r=0.7835, P<0.01) and exhibited stem-like properties. Then, we determined the tumorigenic effects of CD2 on the growth of transplanted Lewis lung carcinoma cells (LLC1) in C57/BL6 mice. The results indicated that CD2⁺ cells were effective in promoting tumor growth in vivo (P<0.01). Furthermore, we obtained direct evidence of an ability of CD133⁺ cells to transform to T-helper 17-like cells via an intermediate CD133⁺CD2⁺ progenitor cell that is able to secrete IL-17A and IL-23. Furthermore, we found that IL-2 can inhibit the production of T-helper 17-like cells (P<0.001) by modulating the activation of STAT5 signaling pathways to downregulate the expression of RORγt (P<0.001).

Conclusions

Our data demonstrates that Th17-like cells generated from CSCs support cancer progression. These findings enrich the definition of multidirectional differentiation potential of CSCs and improve the understanding of the role of CSCs in cancer progression, which aids the improvement and creation of therapies.

Tumor-infiltrating CD8+ T cell antitumor efficacy and exhaustion: molecular insights

Host immunity has an essential role in the clinical management of cancers. Therefore, it is advantageous to choose therapies that can promote tumor cell death and concurrently boost host immunity. The dynamic tumor microenvironment (TME) determines whether an antineoplastic drug will elicit favorable or disparaging immune responses from tumor-infiltrating lymphocytes (TILs). CD8+ T cells are one of the primary tumor-infiltrating immune cells that deliver antitumor responses. Here, we review the influence of various factors in the TME on CD8+ T cell exhaustion and survival, and possible strategies for restoring CD8+ T cell effector function through immunotherapy.