Camouflage and sabotage: tumor escape from the immune system

Cancer and treatment specific incidence rates of immune-related adverse events induced by immune checkpoint inhibitors: a systematic review

BACKGROUND

Immune-related adverse events (irAE) induced by immune checkpoint inhibitors (ICI) are a treatment-limiting barrier. There are few large-scale studies that estimate irAE prevalence. This paper presents a systematic review that reports the prevalence of irAE by cancer type and ICI.

METHODS

A systematic review was undertaken in MEDLINE OVID, EMBASE and Web of Science databases from 2017-2021. A total of 293 studies were identified for analysis and, of these, event rate was calculated for 272 studies, which involved 58,291 patients with irAE among 305,879 total patients on ICI. Event rate was calculated by irAE and ICI type.

RESULTS

Mean event rate for general irAE occurrence across any grade was 40.0% (37.3-42.7%) and high grade was 19.7% (15.8-23.7%). Mean event rates for six specific types of irAE are reported. Mean event rate for ICI monotherapy was 30.5% (28.1-32.9%), 45.7% (29.6-61.7%) for ICI combination therapy, and 30.0% (25.3-34.6%) for both ICI monotherapy and combination therapy.

CONCLUSION

This systematic review characterises irAE prevalence across current research that examines irAE risk factors across cancers and ICI. The findings confirms that irAE occurrence is very common in the real-world setting, both high grade and irAE across any grade.

Novel research model for in vitro immunotherapy: co-culturing tumor organoids with peripheral blood mononuclear cells

Tumor organoids have emerged as powerful tools for in vitro cancer research due to their ability to retain the structural and genetic characteristics of tumors. Nevertheless, the absence of a complete tumor microenvironment (TME) limits the broader application of organoid models in immunological studies. Given the critical role of immune cells in tumor initiation and progression, the co-culture model of organoids and peripheral blood mononuclear cells (PBMCs) may provide an effective platform for simulating the interactions between immune and tumor cells in vitro. This model stands as a robust instrument for dissecting the TME, elucidating the molecular interactions, and exploring the therapeutic applications of chimeric antigen receptor (CAR)-engineered lymphocytes, as well as other cancer treatment modalities. This review systematically evaluates the advantages and disadvantages of the co-culture model, identifies its technical bottlenecks, and proposes corresponding optimization strategies. By summarizing the latest research advancements in this co-culture model, our goal is to provide valuable insights for further model optimization and clinical application, thereby promoting immunological research and bridging the gap between experimental outcomes and clinical practice.

Immune Checkpoint Inhibitor-Associated Cutaneous Adverse Events: Mechanisms of Occurrence

Immunotherapy, particularly that based on blocking checkpoint proteins in many tumors, including melanoma, Merkel cell carcinoma, non-small cell lung cancer (NSCLC), triple-negative breast (TNB cancer), renal cancer, and gastrointestinal and endometrial neoplasms, is a therapeutic alternative to chemotherapy. Immune checkpoint inhibitor (ICI)-based therapies have the potential to target different pathways leading to the destruction of cancer cells. Although ICIs are an effective treatment strategy for patients with highly immune-infiltrated cancers, the development of different adverse effects including cutaneous adverse effects during and after the treatment with ICIs is common. ICI-associated cutaneous adverse effects include mostly inflammatory and bullous dermatoses, as well as severe cutaneous side reactions such as rash or inflammatory dermatitis encompassing erythema multiforme; lichenoid, eczematous, psoriasiform, and morbilliform lesions; and palmoplantar erythrodysesthesia. The development of immunotherapy-related adverse effects is a consequence of ICIs' unique molecular action that is mainly mediated by the activation of cytotoxic CD4+/CD8+ T cells. ICI-associated cutaneous disorders are the most prevalent effects induced in response to anti-programmed cell death 1 (PD-1), anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and anti-programmed cell death ligand 1 (PD-L1) agents. Herein, we will elucidate the mechanisms regulating the occurrence of cutaneous adverse effects following treatment with ICIs.

Into the Future: Fighting Melanoma with Immunity

Immunotherapy offers a novel and promising option in the treatment of late-stage melanoma. By utilizing the immune system to assist in tumor destruction, patients have additional options after tumor progression. Immune checkpoint inhibitors reduce the ability for tumors to evade the immune system by inhibiting key surface proteins used to inactivate T-cells. Without these surface proteins, T-cells can induce cytotoxic responses against tumors. Tumor infiltrating lymphocyte therapy is a form of adoptive cell therapy that takes advantage of a small subset of T-cells that recognize and infiltrate tumors. Isolation and rapid expansion of these colonies assist the immune system in mounting a charged response that can induce remission. Tumor vaccines deliver a high dose of unique antigens expressed by tumor cells to the entire body. The introduction of large quantities of tumor antigens upregulates antigen presenting cells and leads to effective activation of the immune system against tumors. Cytokine therapy introduces high amounts of chemical messengers that are endogenous to the immune system and support T-cell expansion. While other methods of immunotherapy exist, immune checkpoint inhibitors, tumor infiltrating lymphocytes, tumor vaccines, and cytokine therapy are commonly used to treat melanoma. Like many other cancer treatments, immunotherapy is not without adverse effects, as toxicities represent a major obstacle. However, immunotherapy has been efficacious in the treatment of melanoma.

Breaking the 'don't eat me' signal: in silico design of CD47-directed peptides for cancer immunotherapy

The leading cause of death worldwide is cancer. Although there are various therapies available to treat cancer, finding a successful one can be like searching for a needle in a haystack. Immunotherapy appears to be one of those needles in the haystack of cancer treatment. Immunotherapeutic agents enhance the immune response of the patient's body to tumor cells. One of the immunotherapeutic targets, Cluster of Differentiation 47 (CD47), releases the "don't eat me" signal when it binds to its receptor, Signal Regulatory Protein (SIRPα). Tumor cells use this signal to circumvent the immune system, rendering it ineffective. To stop tumor cells from releasing the "don't eat me" signal, the CD47-SIRPα interaction is specifically targeted in this study. To do so, in silico peptides were designed based on the structural analysis of the interaction between two proteins using point mutations on the interacting residues with the other amino acids. The peptide library was designed and docked on SIRPα using computational tools. Later on, after analyzing the docked complex, the best of them was selected for MD simulation studies of 100 ns. Further analysis after MD studies was carried out to determine the possible potential anti-SIRPα peptides.

Gastric cancer fibroblasts affect the effect of immunotherapy and patient prognosis by inducing micro-vascular production

Introduction

Immunotherapy is critical for treating many cancers, and its therapeutic success is linked to the tumor microenvironment. Although anti-angiogenic drugs are used to treat gastric cancer (GC), their efficacy remains limited. Cancer-associated fibroblast (CAF)-targeted therapies complement immunotherapy; however, the lack of CAF-specific markers poses a challenge. Therefore, we developed a CAF angiogenesis prognostic score (CAPS) system to evaluate prognosis and immunotherapy response in patients with GC, aiming to improve patient stratification and treatment efficacy.

Methods

We assessed patient-derived GC CAFs for promoting angiogenesis using EdU, cell cycle, apoptosis, wound healing, and angiogenesis analysis.

Results

We then identified CAF-angiogenesis-associated differentially-expressed genes, leading to the development of CAPS, which included THBS1, SPARC, EDNRA, and VCAN. We used RT-qPCR to conduct gene-level validation, and eight GEO datasets and the HPA database to validate the CAPS system at the gene and protein levels. Six independent GEO datasets were utilized for validation. Overall survival time was shorter in the high- than the low-CAPS group. Immune microenvironment and immunotherapy response analysis showed that the high-CAPS group had a greater tendency toward immune escape and reduced immunotherapy efficacy than the low-CAPS group.

Discussion

CAPS is closely associated with GC prognosis and immunotherapy outcomes. It is therefore an independent predictor of GC prognosis and immunotherapy efficacy.

Effects of propofol intravenous general anesthesia and inhalational anesthesia on T-lymphocyte activity after breast cancer surgery: A meta-analysis

Background

Breast cancer is one of the most common cancers in women. General anesthesia is a commonly used anesthesia method for breast cancer surgery, and studies have confirmed that general anesthesia can induce immunosuppression in breast cancer patients and increase the metastasis rate of tumors. However, the difference between the effects of intravenous general anesthesia and inhalation anesthesia on the function of T-lymphocytes is still controversial, and it is necessary to explore reasonable anesthesia methods to reduce immunosuppression caused by surgery and anesthesia.

Materials and Methods

Databases (Embase, PubMed, Cochrane Library, CBM, CNKI, and Wanfang) were searched (up to October 2022) for randomized controlled trials (RCTs) comparing intraoperative inhalation anesthesia and propofol intravenous anesthesia in breast cancer patients, with the outcome of T-lymphocyte subsets. The meta-analysis was performed by STATA 14.0.

Results

Six RCTs with 352 patients were included in the study. Compared with inhalation anesthesia, there was no difference in T-lymphocyte subsets between the two groups immediately after surgery, but the activities of CD4+ T cells in patients with propofol anesthesia were higher (standard mean difference [SMD] = 0.234, 95% confidence interval [CI]: 0.003-0.466, P = 0.047, I2 = 44.1%) than those under inhalation anesthesia 1 day after surgery, and CD4+/CD8+ activities in patients with propofol anesthesia were higher (SMD = 304, 95% CI: 0.072-0.537, P = 0.010, I2 = 48.0%) than those under inhalation anesthesia 1 day after surgery.

Conclusion

There were no differences in the effects of propofol and inhalation anesthetics on T-lymphocytes immediately after surgery, but the inhibitory effects of inhalation anesthetics on CD4+ and CD4+/CD8+ cells were stronger 1 day after surgery.

Impact on CD4+ CD25 High -CD127 low regulatory T (Treg) cells of neoadjuvant therapy for rectal cancer patients

Background

The efficacy of neoadjuvant therapy for rectal cancer has not been assessed.

Objective

To evaluate proportional changes in peripheral blood immune cells in rectal cancer patients after neoadjuvant therapy and assess the relationship between tumor regression and regulatory T (Treg) cells.

Materials and Methods

Rectal cancer patients who had received neoadjuvant therapy prior to surgery at Shanxi Cancer Hospital between January and September 2018 were enrolled in the study. Treg, CD4+ T, CD8+ T, NK, B cells, and CD4+/CD8+ ratio in peripheral blood before and after neoadjuvant therapy were measured by flow cytometry. Patients were divided into down-staging and control groups, depending on their responses to neoadjuvant therapy.

Results

A total of 108 patients were enrolled. The proportion of Treg cells was significantly lower after neoadjuvant therapy (P < 0.05) but no changes were seen in CD4+ T, CD8+ T, NK, B cells, or CD4+/CD8+ ratio (all P > 0.05). There were 76 patients in the down-staging and 32 in the control groups. There were no significant differences in clinical parameters between down-staging and control groups (all P > 0.05). There were no significant differences in immune cell proportions between the two groups prior to neoadjuvant therapy (all P > 0.05). Treg, CD4+ T, and B cells were all significantly lower in the down-staging group after neoadjuvant therapy than before (P < 0.05). CD4+/CD8+ ratios were lower (P < 0.05) while proportions of Treg and natural killer (NK) cells did not change after neoadjuvant therapy in the control group. Following neoadjuvant therapy, Treg and B cells were lower while CD4+ and CD4+/CD8+ ratios were higher in the down-staging group compared to the control group (P < 0.01).

Conclusion

Treg cells may constitute a reference for judging the effect of neoadjuvant therapy in rectal cancer patients.

Friend or Foe? Locoregional Therapies and Immunotherapies in the Current Hepatocellular Treatment Landscape

Over the last several decades, a number of new treatment options for patients with hepatocellular carcinoma (HCC) have been developed. While treatment decisions for some patients remain clear cut, a large numbers of patients have multiple treatment options, and it can be hard for multidisciplinary teams to come to unanimous decisions on which treatment strategy or sequence of treatments is best. This article reviews the available data with regard to two treatment strategies, immunotherapies and locoregional therapies, with a focus on the potential of locoregional therapies to be combined with checkpoint inhibitors to improve outcomes in patients with locally advanced HCC. In this review, the available data on the immunomodulatory effects of locoregional therapies is discussed along with available clinical data on outcomes when the two strategies are combined.

Research progress on PD-1 and PD-L1 inhibitors in the treatment of metastatic urothelial carcinoma

Urothelial carcinoma (UC) is a very common malignant tumor. In the past few decades, platinum-based chemotherapy has been regarded as the standard recommended regimen for patients with metastatic urothelial carcinoma (mUC) who can receive either cisplatin or carboplatin. The emergence of immune checkpoint inhibitors (ICIs) brought some hope for possible treatments for mUC patients who were unfit for platinum therapy. ICIs drugs have emerged as new potential weapons to overcome UC in our lifetime. ICIs block the binding of programmed death-1 (PD-1) to programmed death-ligand 1 (PD-L1), leading to enhancement of the immune function of antitumor T cells. In the treatment of UC, ICIs show an apparent ascendancy and effectively enhance survival rates. With good tolerability and remarkable effects, ICIs have given thousands of patients hope. This article mainly shows the application of PD-1 and PD-L1 inhibitors in mUC.

Selective induction of thymic stromal lymphopoietin expression by novel nitrogen-containing steroid compounds in PAM-212 cells

Background

Thymic stromal lymphopoietin (TSLP) has been shown to be able to amplify Tregs. Thus, TSLP induction has the potential to induce endogenous Tregs and control autoimmunity. In the previous research, we found that a new compound named 02F04 can induce TSLP production while simultaneously activating the liver X receptor (LXR). Because LXR activation leads to a decrease in Treg, we attempted to find a 02F04-derivative, druggable lead compound with a basic skeleton that induces TSLP production without activating LXR. As the results, we found HA-7 and HA-19 and, in this study, examined the molecular mechanisms in TSLP production.

Methods

A murine keratinocyte cell line PAM 212 was stimulated with HA-7 and HA-19, and then the expressions of cytokines were examined via ELISA and real-time fluorescence quantitative PCR.

Results

HA-7 and HA-19 induced TSLP production but almost not the expression of TNF-α, IL-13, IL-25, and IL-33 in PAM212 cells. These compounds inhibited LXR activities. The TSLP expression induced by HA-7 and HA-19 was inhibited by the Gq/11 inhibitor YM-254890, ROCK inhibitor Y-27632, and ERK inhibitor U0126. HA-7 and HA-19 also induced the formation of stress fiber and ERK phosphorylation, which were inhibited by YM-254890 and Y-27632.

Conclusions

Our findings indicated that HA-7 and HA-19 selectively induced TSLP production in PAM212 via Gq/11, Rho/ROCK and ERK pathways. Our findings also indicated that TSLP expression was differentially regulated from other cytokines, and the selective expression could be induced with low-molecular-weight compounds such as HA-7 and HA-19.

Chemotherapy: A partnership with immunotherapy in non-small cell lung cancer

Chemotherapy (CT) and immunotherapy (IO) act synergically in the treatment of non-small cell lung cancer (NSCLC). However, the molecular basis of such interaction is poorly understood. The aim of this review was to explore the mechanisms of CT to potentiate the immune system and, consequently, the action of IO. The most up-to-date knowledge concerning the interaction of CT and IO in NSCLC was reviewed and a bibliographic search was made in PubMed/Medline database, using the mentioned keywords, with preference given to recently published articles in English. In addition to the direct cytotoxic effect, CT affects the immune system leading indirectly to cell death. The immune response triggered by PD-1 inhibition is enhanced by the cytotoxic immunogenic effects of CT. This potentiation phenomenon occurs due to an increase in effector cells relatively to regulatory cells, inhibition of myeloid derived suppressor cells, increased potential for cross-presentation by dendritic cells after the death of tumor cells or blocking the STAT6 pathway to increase dendritic cell activity. In conclusion, the effects of CT on the immune system work in synergy with the actions of IO, transforming "cold" tumors into "hot" tumors, which are more visible to the immune system.

Development and validation of a necroptosis-related gene prognostic score to predict prognosis and efficiency of immunotherapy in gastric cancer

Necroptosis is a novel type of regulated cell death that is intimately associated with a variety of tumors. However, how necroptosis affects the identification of gastric cancer (GC) remains unclear. Here we seek to find new potential necroptosis-related biomarkers to predict GC prognosis and immunotherapy effect. We used Cox analysis to obtain shared prognostic markers related to necroptosis from five datasets (TCGA and four GEO datasets). Then, a necroptosis-related gene prognostic score (NRGPS) system was constructed using LASSO Cox regression, NRGPS consisting of three necroptosis-related mRNAs (AXL, RAI14, and NOX4) was identified, 31 pairs of GC and adjacent normal tissues from the Second Hospital of Harbin Medical University were collected and Real-Time Quantitative PCR (RT-qPCR) was used to detect the relative expression levels of the three necroptosis-related mRNAs, and external validation was performed on four GEO datasets (GSE84437, GSE26901, GSE62254 and GSE15459). In this study, Overall survival (OS) in the high-NRGPS group was significantly lower than in the low-NRGPS group. Cox regression analyses showed that NRGPS was an independent prognostic variable. Tumor-mutation-burden (TMB), tumor microenvironment (TME), microsatellite instability (MSI), and Tumor Immune Dysfunction and Exclusion (TIDE) scoring were used as predictors of the immunotherapy response. A cancer-friendly immune microenvironment, a high TIDE score, a low TMB, and a low MSI were all characteristics of the high-NRGPS group, and they all consistently showed that the issues seen there are related to immune escape in GC. The combination of three candidate genes may be an effective method for diagnostic assessment of GC prognosis and immunotherapy efficacy.

Chemoradiation-induced alteration of programmed death-ligand 1, CD8+ tumor-infiltrating lymphocytes and mucin expression in rectal cancer

Introduction: DNA damage and resulting neoantigen formation is considered a mechanism for synergy between radiotherapy and PD-1/PD-L1 pathway inhibition to induce antitumor immune response. We investigated neoadjuvant chemoradiotherapy (nCRT)-induced changes in CD8+ tumor infiltrating lymphocyte, PD-L1 and mucin expression in rectal cancer patients.

Materials and Methods: Tumor samples of rectal adenocarcinoma patients undergoing resection between 2008-2014 with (n = 62) or without (n = 17) nCRT treatment were collected. Sections were stained with CD8 and PD-L1 antibodies for immunohistochemistry. The prevalence of CD8+ cells was recorded in the tumor, interface tumor and background rectal side. Image analysis was used to determine the density of CD8+ lymphocytes. The percentage of PD-L1 expression was manually counted in tumor cells (TC), tumor stroma (TS) and the invasive front (IF). Mucin expression was determined as the percentage of the mucin area in the whole tumor area.

Results: PD-L1 expression on TCs was identified in 7.6% (6/79) of nCRT specimens (p = 0.33) and in none of the non-nCRT patients. Median densities of CD8+ infiltrating T lymphocytes did not differ significantly between the two groups. Mucin expression was significantly higher in the nCRT cohort (p = 0.02). Higher neutrophil to lymphocytes ratio (NLR) after nCRT was associated with worse outcome (HR = 1.04, 95% CI = 1.00–1.08).

Conclusions: nCRT exposure was associated with a non-significant difference in PD-L1 expression in rectal adenocarcinoma patients, possibly due to sample size limitations. Further mechanistic investigations and comprehensive immune analysis are needed to understand nCRT-induced immunologic shift in rectal cancer and to expand the applicability of checkpoint inhibitors in this setting.

The Role of Tumor Microenvironment and Immune Response in Colorectal Cancer Development and Prognosis

Colorectal cancer (CRC) is one of the most common cancers worldwide. The patient’s prognosis largely depends on the tumor stage at diagnosis. The pathological TNM Classification of Malignant Tumors (pTNM) staging of surgically resected cancers represents the main prognostic factor and guidance for decision-making in CRC patients. However, this approach alone is insufficient as a prognostic predictor because clinical outcomes in patients at the same histological tumor stage can still differ. Recently, significant progress in the treatment of CRC has been made due to improvements in both chemotherapy and surgical management. Immunotherapy-based approaches are one of the most rapidly developing areas of tumor therapy. This review summarizes the current knowledge about the tumor microenvironment (TME), immune response and its interactions with CRC development, immunotherapy and prognosis.

Hyperprogression, a challenge of PD-1/PD-L1 inhibitors treatments: potential mechanisms and coping strategies

Immunotherapy is now a mainstay in cancer treatments. Programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) immune checkpoint inhibitor (ICI) therapies have opened up a new venue of advanced cancer immunotherapy. However, hyperprogressive disease (HPD) induced by PD-1/PD-L1 inhibitors caused a significant decrease in the overall survival (OS) of the patients, which compromise the efficacy of PD-1/PD-L1 inhibitors. Therefore, HPD has become an urgent issue to be addressed in the clinical uses of PD-1/PD-L1 inhibitors. The mechanisms of HPD remain unclear, and possible predictive factors of HPD are not well understood. In this review, we summarized the potential mechanisms of HPD and coping strategies that can effectively reduce the occurrence and development of HPD.

Bacteria and tumor: Understanding the roles of bacteria in tumor genesis and immunology

In the past, tumor and microbial infection were commonly regarded as independent diseases with few interrelations. The discovery of bacteria in tumor tissue changed the knowledge of bacteria-tumor relationship. Recently, more and more findings have demonstrated the significant effects of bacteria on the genesis, development and metastasis of tumor. Particularly, the influence of bacteria on tumor immunity is of great interest. Bacteria can inhibit the function of immune system through multiple mechanisms. On the other hand, some bacteria can also enhance the immune response and inhibit tumor progression. Understanding the bacteria-tumor interactions is of great importance for developing novel anticancer approaches. Herein, we aim to provide a comprehensive understanding of the tumor/tumor immunology, the biogenesis of bacteria in tumor and the relation of tumorigenesis with bacteria. In addition, the roles of bacteria in tumor immunology and the potential approaches to use bacteria for cancer therapy are discussed.

Roles and new Insights of Macrophages in the Tumor Microenvironment of Thyroid Cancer

Although most thyroid cancers have a good and predictable prognosis, the anaplastic, medullary, and refractory thyroid cancers still prone to recurrence and metastasis, resulting in poor prognosis. Although a number of newly developed targeted therapies have begun to be indicated for the above types of thyroid cancer in recent years, their ability to improve overall survival remain hindered by low efficacy. As the largest component of immune cells in tumor microenvironment, tumor-associated macrophages play a key role in the invasion and metastasis of thyroid cancer. There is much evidence that the immune system, tumor microenvironment and cancer stem cell interactions may revolutionize traditional therapeutic directions. Tumor-associated macrophages have been extensively studied in a variety of tumors, however, research on the relationship between thyroid cancer and macrophages is still insufficient. In this review, we summarize the functions of tumor-associated macrophages in different types of thyroid cancer, their cytokines or chemokines effect on thyroid cancer and the mechanisms that promote tumor proliferation and migration. In addition, we discuss the mechanisms by which tumor-associated macrophages maintain the stemness of thyroid cancer and potential strategies for targeting tumor-associated macrophages to treat thyroid cancer.

Prognostic Implications of Immune Infiltrates in the Breast Cancer Microenvironment: The Role of Expressions of CTLA-4, PD-1, and LAG-3

The assessment of immune infiltrate in invasive breast carcinomas (IBCs), most commonly referred to as tumor infiltrating lymphocytes (TILs), is gaining importance in the current quest for optimal biomarker selection and prediction of prognosis. In this study, the impact of intensity of TILs and expressions of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death-1 (PD-1), and lymphocyte activation gene 3 (LAG-3) in a group of breast carcinomas with regards to the prognosis and conventional pathologic parameters was scrutinized. For this purpose, 238 patients with IBCs containing different proportions of TILs were included in the study. IBCs with higher proportion of TILs were usually grade III carcinomas and correlated with poor prognostic features like receptor negativity, nonluminal intrinsic subtype (P<0.001). Similarly, PD-1 and LAG-3 positivity in immune cells (IC) were more likely to be positive in grade III IBC cases (P=0.004). In addition, PD-1 positivity in IC was more frequent in estrogen receptor-negative tumors (P=0.011) whereas LAG-3 positivity increased in large sized, estrogen receptor and progesterone receptor-negative tumors (P=0.050, 0.023, 0.04, respectively). CTLA-4 positivity in IC was more frequent in large-sized tumors (P=0.040). These 3 markers were also significantly associated with one another and also with the amount of TILs. In survival analysis, cases with prominent-TILs especially displaying CTLA-4, PD-1, and LAG-3 positivity appeared to have longer disease-free and overall survival (CTLA-4: P=0.027, P=0.024; PD-1: P=0.030, P=0.026; LAG-3: P=0.006, P=0.012, respectively). We conclude that the high proportion of TILs and as well as high expression of CTLA-4, PD-1, and LAG-3 in TILs have positively contributed to the outcome despite their correlation with poor conventional pathologic features. We suggest that these 3 immune markers can be used for the determination of proper treatment as well as prediction of prognosis in IBCs with TILs.

Association of PD-1 and PDL-1 gene polymorphisms with colorectal cancer risk and prognosis

BACKGROUND

Programmed Cell Death-1 (PD-1) together with Programmed Death Ligand 1 (PDL-1) have crucial roles in anti-tumor immune response, cancer susceptibility and prognosis. Since PD-1 and PDL-1 have been considered as important genetic risk factors in cancer development and their functions can be affected by polymorphic sites, we investigated the effects of PD-1 rs2227981, rs2227982, rs36084323 and PDL-1 rs2282055, rs822336 gene polymorphisms on colorectal cancer (CRC) risk and prognosis in Turkish subjects.

METHODS AND RESULTS

Our study group consisted of 5-FU or Capacitabine prescribed CRC diagnosed patients and healthy controls. Genotype analyses of PD1 and PDL-1 polymorphisms were performed with Agena MassARRAY platform. rs36084323 CT genotype frequency was found to be higher in controls compared to cases (p < 0.001). rs36084323 CT genotype was highly associated with reduced CRC risk compared to CC genotype (OR 0.068, 95% CI 0.022-0.211, p < 0.001). In adjusted analysis, rs2282055 GG genotype was found to be associated with reduced CRC risk (OR 0.271, 95% CI 0.078-0.940, p = 0.040). rs2282055 TT genotype was found to be related to longer progression-free (Bonferroni corrected Log rank p = 0.013) and overall survival (Bonferroni corrected Log rank p = 0.009) to that of GG genotypes. Patients with rs822336 GC+CC genotypes showed longer overall survival times compared to GG (Log rank p = 0.044).

CONCLUSIONS

According to our results, PD-1 rs822336 G > C polymorphism might be useful in predicting CRC prognosis. PDL-1 rs2282055 T > G polymorphism might be useful in predicting both CRC risk and prognosis. Further studies should be conducted in larger and different populations to clear the roles of PD-1 and PDL-1 polymorphisms in CRC risk and prognosis.

Factors Determining Long-Term Antitumor Responses to Immune Checkpoint Blockade Therapy in Melanoma

With the increasing promise of long-term survival with immune checkpoint blockade (ICB) therapies, particularly for patients with advanced melanoma, clinicians and investigators are driven to identify prognostic and predictive factors that may help to identify individuals who are likely to experience durable benefit. Several ICB combinations are being actively developed to expand the armamentarium of treatments for patients who may not achieve long-term responses to ICB single therapies alone. Thus, negative predictive markers are also of great interest. This review seeks to deepen our understanding of the mechanisms underlying the durability of ICB treatments. We will discuss the currently available long-term data from the ICB clinical trials and real-world studies describing the survivorship of ICB-treated melanoma patients. Additionally, we explore the current treatment outcomes in patients rechallenged with ICB and the patterns of ICB resistance based on sites of disease, namely, liver or CNS metastases. Lastly, we discuss the landscape in melanoma in the context of prognostic or predictive factors as markers of long-term response to ICB.

Cancer Therapy Targeting CD47/SIRPα

Simple Summary

The interaction between cluster of differentiation 47 (CD47) on cancer cells and signal regulatory protein alpha (SIRPα) on immune cells, such as macrophages and dendritic cells, generates a “don’t eat me” signal. This is a common mechanism that provides cancer cells an escape from the innate immune system. Several therapeutics directed to CD47 or SIRPα have entered early clinical trials in recent years. In this article, we review the role of CD47/SIRPα axis in cancer, and summarize the literature on the efficacy and safety of therapeutics targeting CD47 or SIRPα. We also discuss the future implementation of these therapeutics in the treatments of various cancer types.

Abstract

In the past decade, the field of cancer immunotherapy has rapidly advanced, establishing a crucial role for immune checkpoint blockers in the treatment of a variety of cancer types. In parallel with these remarkable clinical developments, further efforts have focused on ways of unleashing adaptive immune responses against cancer. CD47, a cell surface molecule overexpressed by several cancer types that facilitates immune escape from macrophages, dendritic cells and natural killer cells, and its ligand SIRPα, have emerged as potential therapeutic targets. A number of agents directed to CD47/SIRPα have been developed and demonstrated preclinical activity. Early phase clinical trials are investigating CD47/SIRPα directed agents with available data, suggesting safety and preliminary activity. Herein, we provide an overview of the mechanistic rationale of targeting CD47/SIRPα axis and associated clinical evidence.

Current trends of anti-cancer molecular targeted therapies: a narrative review focusing on renal complications and their histological features

Among the recent advancements in cancer treatment, the emergence of novel drugs targeting a specific molecule has considerably modulated the therapeutic strategies. Despite the efficacy, the associated renal complications distinct from conventional chemotherapeutic drugs have been reported. Targeted therapy drugs include monoclonal antibodies and small molecule agents. Bevacizumab is one of the monoclonal antibodies that targets vascular endothelial growth factor (VEGF) and blocks tumor angiogenesis. This anti-angiogenic effect causes endothelial injury, resulting in "thrombotic microangiopathy-like lesion" confined to the glomerulus. Segmental hyalinosis of the glomerular tuft is also observed. The small molecular agents, including tyrosine kinase inhibitors (TKIs), such as pazopanib, can cause endothelial injury and podocytopathy through blocking VEGF receptors and their downstream signaling. Minimal change nephrotic syndrome and focal segmental glomerulosclerosis are associated with TKIs-induced renal complications. Immune checkpoint inhibitors (ICIs), such as PD-1, CTLA-4 and PD-L1, are a novel form of immunotherapy against cancer, which modulates immune checkpoints. Owing to its unique function, ICIs cause inflammatory side effects referred to as immune-related adverse events (irAEs). irAEs in the kidney commonly include acute tubulointerstitial nephritis and tubulitis, occasionally accompanied by granuloma formation. The occurrence of vasculitis, thrombotic microangiopathy, and glomerulonephritis is also reported. Renal toxicity associated with other molecular drugs such as protease inhibitors and mammalian target of rapamycin inhibitors has also been documented. In this article, we review the clinico-histopathological aspects of renal complications associated with molecular targeted therapies, focusing on anti-VEGF agents and immune checkpoint inhibitors from the pathologists' viewpoint.

Shuyu pills inhibit immune escape and enhance chemosensitization in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is characterized by dysregulation of the immune microenvironment and the development of chemoresistance. Specifically, expression of the programmed cell death protein 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) axis, an immune checkpoint, may lead to tumour immune escape, resulting in disease progression. The latest research shows that tumour immune escape may be caused by the upregulation of PD-L1 mediated by hypoxia-inducible factor-1 alpha (HIF-1α), and simultaneous inhibition of HIF-1α and PD-L1 has the potential to enhance the host’s antitumour immunity. Moreover, inhibition of the PD-1/PD-L1 axis may mitigate tumour chemoresistance. Shuyu pills (SYPs) contain immunity-enhancing and antitumour components, making them a potential HCC treatment.

AIM

To investigate the efficacy of SYPs for HCC treatment via simultaneous HIF-1α and PD-L1 inhibition and the mechanism involved.

METHODS

A subcutaneous xenograft tumour model was first established in BALB/c nude mice by the subcutaneous injection of 1 × 10⁷ SMMC-7721 cells. Male mice (male, 5 weeks old; n = 24) were then randomly divided into the following four groups (n = 6): Control (0.9% normal saline), SYP (200 mg/kg), SYP + cisplatin (DDP) (200 mg/kg + 5 mg/kg DDP weekly via intraperitoneal injection), and DDP (5 mg/kg cisplatin weekly via intraperitoneal injection). The dose of saline or SYPs for the indicated mouse groups was 0.2 mL/d via intragastric administration. The tumour volumes and body weights of the mice were measured every 2 d. The mice were euthanized by cervical dislocation after 14 d of continuous treatment, and the xenograft tissues were excised and weighed. Western blot assays were used to measure the protein expression of HIF-1α, PD­1, PD-L1, CD4+ T cells, and CD8+ T cells in HCC tumours from mice. Quantitative reverse transcription polymerase chain reaction was used for real-time quantitative detection of PD-1, PD-L1, and HIF-1α mRNA expression. An immunofluorescence assay was conducted to examine the expression of CD4+ T cells and CD8+ T cells.

RESULTS

Compared to mice in the control group, those in the SYP and SYP + DDP groups exhibited reduced tumour volumes and tumour weights. Moreover, the protein and mRNA expression levels of the oncogene HIF­1α and that of the negative immunomodulatory factors PD-1 and PD-L1 were decreased in both the SYP and SYP + DDP groups, with the decrease effects being more prominent in the SYP + DDP group than in the SYP group (HIF-1α protein: Control vs SYP, P = 0.0129; control vs SYP + DDP, P = 0.0004; control vs DDP, P = 0.0152, SYP + DDP vs DDP, P = 0.0448; HIF-1α mRNA: control vs SYP, P = 0.0009; control vs SYP + DDP, P < 0.0001; control vs DDP, P = 0.0003, SYP vs SYP + DDP, P = 0.0192. PD-1 protein: Control vs SYP, P = 0.0099; control vs SYP + DDP, P < 0.0001, SPY vs SYP + DDP, P = 0.0009; SYP + DDP vs DDP, P < 0.0001; PD-1 mRNA: control vs SYP, P = 0.0002; control vs SYP + DDP, P < 0.0001; control vs DDP, P = 0.0003, SPY vs SYP + DDP, P = 0.0003; SYP + DDP vs DDP, P = 0.0002. PD-L1 protein: control vs SYP, P < 0.0001; control vs SYP + DDP, P < 0.0001; control vs DDP, P < 0.0001, SPY vs SYP + DDP, P = 0.0040; SYP + DDP vs DDP, P = 0.0010; PD-L1 mRNA: Control vs SYP, P < 0.0001; control vs SYP + DDP, P < 0.0001; control vs DDP, P < 0.0001, SPY vs SYP + DDP, P < 0.0001; SYP + DDP vs DDP, P = 0.0014). Additionally, the quantitative and protein expression levels of CD4+ T cells and CD8+ T cells were simultaneously upregulated in the SYP + DDP group, whereas only the expression of CD4+ T cells was upregulated in the SYP group. (CD4+ T cell quantitative: Control vs SYP + DDP, P < 0.0001, SYP vs SYP + DDP, P = 0.0005; SYP + DDP vs DDP, P = 0.0002. CD4+ T cell protein: Control vs SYP, P = 0.0033; Control vs SYP + DDP, P < 0.0001; Control vs DDP, P = 0.0021, SYP vs SYP + DDP, P = 0.0004; SYP + DDP vs DDP, P = 0.0006. Quantitative CD8+ T cells: Control vs SYP + DDP, P = 0.0013; SYP vs SYP + DDP, P = 0.0347; SYP + DDP vs DDP, P = 0.0043. CD8+ T cell protein: Control vs SYP + DDP, P < 0.0001; SYP vs SYP + DDP, P < 0.0001; SYP + DDP vs DDP, P < 0.0001). Finally, expression of HIF-1α was positively correlated with that of PD-1/PD-L1 and negatively correlated with the expression of CD4+ T cells and CD8+ T cells.

CONCLUSION

SYPs inhibit immune escape and enhance chemosensitization in HCC via simultaneous inhibition of HIF-1α and PD-L1, thus inhibiting the growth of subcutaneous xenograft HCC tumours.

Ferroptosis-related gene model to predict overall survival of papillary thyroid carcinoma

BACKGROUND

Ferroptosis is a form of programmed cell death that is closely associated with the development of various tumors. However, the correlation between ferroptosis and papillary thyroid carcinoma (PTC) is unclear. This study was performed to investigate the expression and prognostic value of ferroptosis-related genes (FRG) in PTC.

METHODS

mRNA expression profiles and corresponding clinical data of patients with PTC were analyzed to identify factors affecting prognosis. Independent risk factors were used to establish a predictive receiver operating characteristic model. Single-sample gene set enrichment analysis (ssGSEA) was used to evaluate the correlation between ferroptosis and immune cells.

RESULTS

Most genes related to FRG (78.8%) were differentially expressed between the tumor and adjacent normal tissues. In univariate Cox regression analysis, 12 differentially expressed genes were associated with prognostic survival. We constructed a prognostic model of eight FRG, including DPP4, GPX4, GSS, ISCU, MIOX, PGD, TF, and TFRC, and divided patients into two groups: high and low risk. The high-risk group exhibited a significantly reduced overall survival rate. In multivariate Cox regression analysis, the risk score was used as an independent prognostic factor. ssGSEA showed that immune cell types and their expression in the high- and low-risk groups were significant.

CONCLUSION

This study constructed a prognostic model of ferroptosis-related genes and determined its usefulness as an independent prognostic factor, providing a reference for the treatment and prognosis of patients with PTC.

ROS Cocktails as an Adjuvant for Personalized Antitumor Vaccination?

Cancer is the second leading cause of death worldwide. Today, the critical role of the immune system in tumor control is undisputed. Checkpoint antibody immunotherapy augments existing antitumor T cell activity with durable clinical responses in many tumor entities. Despite the presence of tumor-associated antigens and neoantigens, many patients have an insufficient repertoires of antitumor T cells. Autologous tumor vaccinations aim at alleviating this defect, but clinical success is modest. Loading tumor material into autologous dendritic cells followed by their laboratory expansion and therapeutic vaccination is promising, both conceptually and clinically. However, this process is laborious, time-consuming, costly, and hence less likely to solve the global cancer crisis. Therefore, it is proposed to re-focus on personalized anticancer vaccinations to enhance the immunogenicity of autologous therapeutic tumor vaccines. Recent work re-established the idea of using the alarming agents of the immune system, oxidative modifications, as an intrinsic adjuvant to broaden the antitumor T cell receptor repertoire in cancer patients. The key novelty is the use of gas plasma, a multi-reactive oxygen and nitrogen species-generating technology, for diversifying oxidative protein modifications in a, so far, unparalleled manner. This significant innovation has been successfully used in proof-of-concept studies and awaits broader recognition and implementation to explore its chances and limitations of providing affordable personalized anticancer vaccines in the future. Such multidisciplinary advance is timely, as the current COVID-19 crisis is inexorably reflecting the utmost importance of innovative and effective vaccinations in modern times.

Soluble cytotoxic T-lymphocyte-associated antigen 4 (sCTLA-4) as a potential biomarker for diagnosis and evaluation of the prognosis in Glioma

Background

The cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) is widely considered as a pivotal immune checkpoint molecule to suppress antitumor immunity. However, the significance of soluble CTLA-4 (sCTLA-4) remains unclear in the patients with brain glioma. Here we aimed to investigate the significance of serum sCTLA-4 levels as a noninvasive biomarker for diagnosis and evaluation of the prognosis in glioma patients.

Methods

In this study, the levels of sCTLA-4 in serum from 50 patients diagnosed with different grade gliomas including preoperative and postoperative, and 50 healthy individuals were measured by an enzyme-linked immunosorbent assay (ELISA). And then ROC curve analysis and survival analyses were performed to explore the clinical significance of sCTLA-4.

Results

Serum sCTLA-4 levels were significantly increased in patients with glioma compared to that of healthy individuals, and which was also positively correlated with the tumor grade. ROC curve analysis showed that the best cutoff value for sCTLA-4 for glioma is 112.1 pg/ml, as well as the sensitivity and specificity with 82.0 and 78.0%, respectively, and a cut-off value of 220.43 pg/ml was best distinguished in patients between low-grade glioma group and high-grade glioma group with sensitivity 73.1% and specificity 79.2%. Survival analysis revealed that the patients with high sCTLA-4 levels (> 189.64 pg/ml) had shorter progression-free survival (PFS) compared to those with low sCTLA-4 levels (≤189.64 pg/ml). In the univariate analysis, elder, high-grade tumor, high sCTLA-4 levels and high Ki-67 index were significantly associated with shorter PFS. In the multivariate analysis, sCTLA-4 levels and tumor grade remained an independent prognostic factor.

Conclusion

These findings indicated that serum sCTLA-4 levels play a critical role in the pathogenesis and development of glioma, which might become a valuable predictive biomarker for supplementary diagnosis and evaluation of the progress and prognosis in glioma.

Targeting the MHC Class II antigen presentation pathway in cancer immunotherapy

The success of immunotherapy relies on the participation of all arms of the immune system and the role of CD4+ T lymphocytes in preventing tumor growth is now well established. Understanding how tumors evade immune responses holds the key to the development of cancer immunotherapies. In this review, we discuss how MHC Class II expression varies in cancer cells and how this influences antitumor immune responses. We also discuss the means that are currently available for harnessing the MHC Class II antigen presentation pathway for the development of efficient vaccines to activate the immune system against cancer.

Chemoimmunotherapy for advanced gastrointestinal carcinomas: A successful combination of gene therapy and cyclophosphamide

The combination of a single low dose of cyclophosphamide (Cy) with the adenovirus-mediated gene transfer of interleukin-12 (AdIL-12) might represent a successful therapy for experimental gastrointestinal tumors. This approach has been proven to revert immunosuppressive mechanisms elicited by cancer cells and to synergistically promote antitumor immunity. In addition, this therapeutic regimen has been shown to be more efficient in achieving complete tumor regressions in mice than the application of a metronomic schedule of Cy plus AdIL-12.

Tumor Microenvironment-Associated Pericyte Populations May Impact Therapeutic Response in Thyroid Cancer

Thyroid cancer is the most common endocrine malignancy, and aggressive radioactive iodine refractory thyroid carcinomas still lack an effective treatment. A deeper understanding of tumor heterogeneity and microenvironment will be critical to establishing new therapeutic approaches. One of the important influencing factors of tumor heterogeneity is the diversity of cells in the tumor microenvironment. Among these are pericytes, which play an important role in blood vessel stability and angiogenesis, as well as tumor growth and metastasis. Pericytes also have stem cell-like properties and are a heterogeneous cell population, and their lineage, which has been challenging to define, may impact tumor resistance at different tumor stages. Pericytes are also important stroma cell types in the angiogenic microenvironment which express tyrosine-kinase (TK) pathways (e.g., PDGFR-β). Although TK inhibitors (TKI) and BRAF^V600E inhibitors are currently used in the clinic for thyroid cancer, their efficacy is not durable and drug resistance often develops. Characterizing the range of distinct pericyte populations and distinguishing them from other perivascular cell types may enable the identification of their specific functions in the thyroid carcinoma vasculature. This remains an essential step in developing new therapeutic strategies. Also, assessing whether thyroid tumors hold immature and/or mature vasculature with pericyte populations coverage may be key to predicting tumor response to either targeted or anti-angiogenesis therapies. It is also critical to apply different markers in order to identify pericyte populations and characterize their cell lineage. This chapter provides an overview of pericyte ontogenesis and the lineages of diverse cell populations. We also discuss the role(s) and targeting of pericytes in thyroid carcinoma, as well as their potential impact on precision targeted therapies and drug resistance.

A prognostic immune predictor, HLA-DRA, plays diverse roles in non-muscle invasive and muscle invasive bladder cancer

BACKGROUND

There is an increasing demand for prognostic immune biomarkers of cancer. The prognostic significance of immune markers has been shown for various cancers, but biomarkers of bladder cancer (BCa) have not been fully evaluated. To clarify the role of human leukocyte antigen DR alpha chain (HLA-DRA) in BCa development, we examined expression of HLA-DRA mRNA in tissue samples of non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC).

MATERIALS AND METHODS

Tissues of 96 NMIBC, 43 MIBC and 59 controls comprising noncancerous BCa surrounding tissues were used to examine the expression of HLA-DRA gene by real-time polymerase chain reaction. The expression of up-stream genes regulating HLA-DRA were also measured to explain the role of HLA-DRA in BCa.

RESULTS

Patients with high grade NMIBC showed higher expression of HLA-DRA than those with low grade NMIBC (P < 0.05). In addition, NMIBC patients who progressed to MIBC showed high expression of HLA-DRA mRNA. Kaplan-Meier analysis showed that NMIBC patients with low expression of HLA-DRA had better progression-free survival than those with high expression (P = 0.004). Moreover, the expression of genes regulating HLA-DRA varied in NMIBC and MIBC, indicating a different immunoregulation effect of HLA-DRA in both cancers.

CONCLUSIONS

High expression of HLA-DRA in NMIBC patients has implications for patient stratification strategies, as well as for BCa tumor immunology.

Pembrolizumab for advanced cervical cancer: safety and efficacy

Introduction: Pembrolizumab is an immune checkpoint inhibitor with high specificity for binding to the programmed cell death 1 (PD-1) receptor. It has been approved by the FDA in patients with recurrent or metastatic cervical cancer with disease progression on or after chemotherapy whose tumors express the programmed cell death ligand 1 (PD-L1).Areas covered: Clinical studies of pembrolizumab in cervical cancer were analyzed and discussed. Data were obtained by searching for English peer-reviewed articles on PubMed, clinical trials registered on clincaltrials.gov and related abstracts on the ASCO meeting library. The aim was to review the status of pembrolizumab, the published and ongoing trials, and its safety and efficacy.Expert opinion: Pembrolizumab may ultimately represent a treatment of choice for advanced cervical cancer with PD-L1 expression, both in metastatic and recurrent setting. However, it is essential to better identify and characterize patients that will benefit the most.

Progress in research into the role of abnormal glycosylation modification in tumor immunity

In abnormal glycosylation, molecules of glucose or other carbohydrates in living organisms are inappropriately attached to proteins, which causes protein denaturation. Abnormal glycosylation modification is known to directly or indirectly affect the tumor escape process, but very few studies have been performed on whether protein glycosylation changes the structure and function of immune cells and immune molecules and thereby regulates the occurrence and development of tumor escape. Therefore, this article summarizes the effect of the immune system on tumor escape in association with the abnormal glycosylation process from an immunological perspective.

Immune Checkpoint Therapies for Melanoma

Immunotherapy with immune checkpoint inhibition has dramatically changed the treatment of melanoma. Immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated protein 4 and programmed cell death protein 1 are approved for the treatment of advanced melanoma alone and in combination. In addition, these agents are approved for use in high-risk resected stage III melanoma in the adjuvant setting. Clinical trials testing the combination of immune checkpoint inhibition with other therapies and novel immunotherapies continue. This article reviews the current literature on approved uses of immune checkpoint inhibition in melanoma and discusses ongoing trials and future directions.

Extracellular vesicles in cancer progression: are they part of the problem or part of the solution?

Extracellular vesicles (EVs) are released especially by cancer cells. They modulate the tumor microenvironment by interacting with immune cells while carrying immunosuppressive or immunostimulatory molecules. In this review, we will explore some conflicting reports regarding the immunological outcomes of EVs in cancer progression, in which they might initiate an antitumor immune response or an immunosuppressive response. Concerning immunosuppression, the role of tumor-derived EVs' in the adenosinergic system is underexplored. The enhancement of adenosine (ADO) levels in the tumor microenvironment impairs T-cell function and cytokine release. However, some tumor-derived EVs may deliver immunostimulatory factors, promoting immunogenic activity, even with ADO production. The modulatory role of ADO over the tumor progression represents a piece in an intricate microenvironment with anti and pro tumoral seesaw-like mechanisms.

Papillary thyroid carcinoma with a high tumor mutation burden has a poor prognosis

BACKGROUND

Tumor mutation burden (TMB) as a prognostic marker for immunotherapy has shown prognostic value in many cancers. However, there is no systematic investigation on TMB in papillary thyroid carcinoma (PTC).

METHODS

Based on the somatic mutation data of 487 PTC patients from The Cancer Genome Atlas (TCGA), TMB was calculated, and we classified the samples into high-TMB (H-TMB) and low-TMB (L-TMB) groups. Bioinformatics methods were used to explore the characteristics and potential mechanism of TMB in PTC.

RESULTS

High TMB predicts shorter progression-free survival (PFS) (P < 0.001). TMB was positively correlated with age, stage, tumor size, metastasis, the male sex and tall cell PTC. Compared to the L-TMB group, the H-TMB group presented with lower immune cell infiltration, a higher proportion of tumor-promoting immune cells (M0 macrophages, activated dendritic cells and monocytes) and a lower proportion of antitumor immune cells (M1 macrophages, CD8⁺ T cells and B cells). Additionally, the characteristics displayed by different TMB groups were not driven by critical driver mutations such as BRAF and RAS.

CONCLUSIONS

PTC patients with high TMB have a worse prognosis. By stratifying PTC patients according to their TMB, advanced PTC patients who are candidates for immunotherapy could be selected.

Immune Cell Confrontation in the Papillary Thyroid Carcinoma Microenvironment

Background

Papillary thyroid cancer has been associated with chronic inflammation. A systematic understanding of immune cell infiltration in PTC is essential for subsequent immune research and new diagnostic and therapeutic strategies.

Methods

Three different algorithms, single-sample gene set enrichment analysis (ssGSEA), immune cell marker and CIBERSORT, were used to evaluate immune cell infiltration levels (abundance and proportion) in 10 data sets (The Cancer Genome Atlas [TCGA], GSE3467, GSE3678, GSE5364, GSE27155, GSE33630, GSE50901, GSE53157, GSE58545, and GSE60542; a total of 799 PTC and 194 normal thyroid samples). Consensus unsupervised clustering divided PTC patients into low-immunity and high-immunity groups. Weighted gene coexpression network analysis (WGCNA) and gene set enrichment analysis (GSEA) were used to analyze the potential mechanisms causing differences in the immune response.

Results

Compared with normal tissues, PTC tissues had a higher overall immune level and higher abundance levels and proportions of M2 macrophages, Tregs, monocytes, neutrophils, dendritic cells (DCs), mast cells (MCs), and M0 macrophages. Compared with early PTC, advanced PTC showed higher immune infiltration and higher abundance levels and proportions of M2 macrophages, Tregs, monocytes, neutrophils, DCs, MCs, and M0 macrophages. Compared to the low-immunity group, the high-immunity group exhibited more advanced stages, larger tumor sizes, greater lymph node metastases, higher tall-cell PTCs, lower follicular PTC proportions, more BRAF mutations, and fewer RAS mutations. Epstein-Barr virus (EBV) infection was the most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for key module genes.

Conclusions

In human PTC, M2 macrophages, Tregs, monocytes, neutrophils, DCs, MCs, and M0 macrophages appear to play a tumor-promoting role, while M1 macrophages, CD8+ T cells, B cells, NK cells, and T follicular helper (TFH) cells (including eosinophils, γδ T cells, and Th17 cells with weak supporting evidence) appear to play an antitumor role. During the occurrence and development of PTC, the overall immune level was increased, and the abundance and proportion of tumor-promoting immune cells were significantly increased, indicating that immune escape had been aggravated. Finally, we speculate that EBV may play an important role in changing the immune microenvironment of PTC tumors.

Antibody-drug conjugates, cancer immunotherapy, and metronomic chemotherapy as novel approaches in cancer management

Treatment of cancer is a major challenge even though the pathophysiology is becoming clearer with time. A number of new chemical entities are developed to target cancer growth inhibition, but the targeted delivery of these products still needs novel research. This is of utmost importance not only for higher efficacy but also for a reduction in systemic toxicity and cost of treatment. Although multiple novel targets and molecules are being researched, most of them could not pass the regulatory approval process, due to low benefit-risk ratio and lack of target specificity. Failure of a majority of these drugs was in part due to their superiority claimed via surrogate markers. Despite these, currently, more than 100 chemotherapeutic agents are in practice. This review paper discusses in detail the molecular basis, drug discovery, and pros and cons over conventional treatment approaches of three novel approaches in cancer therapy, i.e., (i) antibody-drug conjugates, (ii) cancer immunotherapy, and (iii) metronomic chemotherapy. All the drugs developed using these three novel approaches were compared against the established treatment regimens in clinical trials with clinical end points, such as overall survival, progression-free survival, and quality of life.

Hepatotoxicity From Immune Checkpoint Inhibitors: A Systematic Review and Management Recommendation

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies targeting immune checkpoint molecules. ICIs are an immunotherapy for the treatment of many advanced malignancies. The advent of ICIs has been a major breakthrough in the field of oncology, a fact recognized by the 2018 Nobel Prize in Physiology or Medicine being awarded for the discovery. The Food and Drug Administration approved the first ICI, ipilimumab, in 2011 for the treatment of metastatic melanoma. Seven ICIs are now used in clinical practice, including nivolumab and pembrolizumab for treatment of advanced hepatocellular carcinoma. ICIs are increasingly used across the spectrum of hepatobiliary neoplasia. The utility of ICI therapy has been limited by immune-related adverse reactions (irAEs) affecting multiple organ systems. Hepatotoxicity is an important irAE, occurring in up to 16% of patients receiving ICIs. Optimizing outcomes in patients receiving ICI therapy requires awareness of and familiarity with diagnosing and management of ICI-induced immune-mediated hepatotoxicity (IMH), including approaches to treatment and ICI dose management. The aim of this review article is to (1) provide a comprehensive, evidence-based review of IMH; (2) perform a systematic review of the management of IMH; and (3) present algorithms for the diagnosis and management of IMH.

Immune Microenvironment of Thyroid Cancer

Thyroid cancer (TC) is a highly heterogeneous endocrine malignancy with an increased incidence in women than in men. Previous studies regarding the pathogenesis of TC focused on the pathological changes of the tumor cells while ignoring the importance of the mesenchymal cells in tumor microenvironment. However, more recently, the stable environment provided by the interaction of thyroid cancer cells with the peri-tumoral stroma has been widely studied. Studies have shown that components of an individual's immune system are closely related to the occurrence, invasion, and metastasis of TC, which may affect response to treatment and prognosis of the patients. This article presents a comprehensive review of the immune cells, secreted soluble mediators and immune checkpoints in the immune microenvironment, mechanisms that promoting TC cells immune evasion and existing immunotherapy strategies. Besides it provides new strategies for TC prognosis prediction and immunotherapy.

Medical Gas Plasma Jet Technology Targets Murine Melanoma in an Immunogenic Fashion

Medical technologies from physics are imperative in the diagnosis and therapy of many types of diseases. In 2013, a novel cold physical plasma treatment concept was accredited for clinical therapy. This gas plasma jet technology generates large amounts of different reactive oxygen and nitrogen species (ROS). Using a melanoma model, gas plasma technology is tested as a novel anticancer agent. Plasma technology derived ROS diminish tumor growth in vitro and in vivo. Varying the feed gas mixture modifies the composition of ROS. Conditions rich in atomic oxygen correlate with killing activity and elevate intratumoral immune-infiltrates of CD8+ cytotoxic T-cells and dendritic cells. T-cells from secondary lymphoid organs of these mice stimulated with B16 melanoma cells ex vivo show higher activation levels as well. This correlates with immunogenic cancer cell death and higher calreticulin and heat-shock protein 90 expressions induced by gas plasma treatment in melanoma cells. To test the immunogenicity of gas plasma treated melanoma cells, 50% of mice vaccinated with these cells are protected from tumor growth compared to 1/6 and 5/6 mice negative control (mitomycin C) and positive control (mitoxantrone), respectively. Gas plasma jet technology is concluded to provide immunoprotection against malignant melanoma both in vitro and in vivo.

Down-regulation of the human major histocompatibility complex class I chain-related gene A (MICA) and its receptor is mediated by microRNA-146b-5p and is a potential mechanism of immunoediting in papillary thyroid carcinoma

Immune escape is one of the main reasons for the rapid progression of cancer and the poor efficacy of immunotherapy. Papillary thyroid cancer (PTC) is usually accompanied by intra-tumoral lymphocytic infiltration. The mechanisms regulating this tumor associated immune response or its evasion are not well understood. The major histocompatibility complex class I chain-related proteins A (MICA) and its receptor the natural killer group 2 member D (NKG2D) are major executers of the anti-tumor defense. This work aimed to study the expression and regulation of MICA-NKG2D and its association with the lymphocytic infiltration and miRNAs in PTC. Expression of MICA and NKG2D in thyroid tissues, and in cultured primary thyroid cancer cells and lymphocytes transfected with miR-146b-5p inhibitor/mimic was tested by RT-PCR. Results were confirmed by immunofluorescence staining and confocal microscopy. MICA is expressed in malignant and benign thyroid tissues with no association with aggressive behavior. Expression of MICA and NKG2D in PTC is concomitant with the presence of tumor associated lymphocytic response and is regulated by miR-146b-5p. MiR-146b-5p indirectly downregulates NKG2D expression in cancer cells and in lymphocytes. Overexpression of miR-146b-5p in PTC down-regulates MICA expression possibly to reduce the immunogenicity of the tumor cells. Targeting of the MICA-NKG2D axis by miR-146b-5p might be one of the ways adopted by thyroid cancer cells to aid the tumor in evading the immune response. The importance of our findings resides in the potential therapeutic use of MICA, NKG2D and miRNA-146b-5p as targets or modulators to enable the immune response against cancer.

Immune Landscape of Thyroid Cancers: New Insights

Immune system plays a key role in cancer prevention as well as in its initiation and progression. During multistep development of tumors, cells must acquire the capability to evade immune destruction. Both in vitro and in vivo studies showed that thyroid tumor cells can avoid immune response by promoting an immunosuppressive microenvironment. The recruitment of immunosuppressive cells such as TAMs (tumor-associated macrophages), TAMCs (tumor-associated mast cells), MDSC (myeloid-derived suppressor cells), TANs (tumor-associated neutrophils) and Tregs (regulatory T cells) and/or the expression of negative immune checkpoints, like PD-L1 (programmed death-ligand 1), CTLA-4 (cytotoxic T-lymphocyte associated protein 4), and/or immunosuppressive enzymes, as IDO1 (indoleamine 2,3-dioxygenase 1), are just some of the mechanisms that thyroid cancer cells exploit to escape immune destruction. Some authors systematically characterized immune cell populations and soluble mediators (chemokines, cytokines, and angiogenic factors) that constitute thyroid cancer microenvironment. Their purpose was to verify immune system involvement in cancer growth and progression, highlighting the differences in immune infiltrate among tumor histotypes. More recently, some authors have provided a more comprehensive view of the relationships between tumor and immune system involved in thyroid carcinogenesis. The Cancer Genome Atlas (TCGA) delivered a large amount of data that allowed to combine information on the inflammatory microenvironment with gene expression data, genetic and clinical-pathological characteristics, and differentiation degree of papillary thyroid carcinoma (PTC). Moreover, using a new sensitive and highly multiplex analysis, the NanoString Technology, it was possible to divide thyroid tumors in two main clusters based on expression of immune-related genes. Starting from these results, the authors performed an immune phenotype analysis that allowed to classify thyroid cancers in hot, cold, or intermediate depending on immune infiltration patterns of the tumor microenvironment. The aim of this review is to provide a comprehensive and updated view of the knowledge on immune landscape of thyroid tumors. Understanding interactions between tumor and microenvironment is crucial to effectively direct immunotherapeutic approaches in the treatment of thyroid cancer, particularly for those not responsive to conventional therapies.

Crystallographic approaches to study the interaction modes of PD-1- and CTLA-4-blocking antibodies

The programmed death 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) are negative regulators of T-cell immune function. Removal of these "brakes" in T cells results in increased activation of the immune system and controlling and eradicating tumor. The development of immune checkpoint inhibitors (ICIs) is a revolutionary milestone in tumor immunotherapy. Obtaining the atomic structure of the human immune checkpoint receptor/ICI therapeutic antibody complex is essential for understanding its inhibition mechanism and the rational design of improved biotherapeutics. In this chapter, we describe the methods for efficient production of extracellular domain of human immune checkpoint receptors and Fv fragments of ICI therapeutic antibodies in milligram quantities sufficient for structural studies, taking examples of the PD-1/pembrolizumab Fv and CTLA-4-ipilimumab Fv complexes.

Immune and Inflammatory Cells in Thyroid Cancer Microenvironment

A hallmark of cancer is the ability of tumor cells to avoid immune destruction. Activated immune cells in tumor microenvironment (TME) secrete proinflammatory cytokines and chemokines which foster the proliferation of tumor cells. Specific antigens expressed by cancer cells are recognized by the main actors of immune response that are involved in their elimination (immunosurveillance). By the recruitment of immunosuppressive cells, decreasing the tumor immunogenicity, or through other immunosuppressive mechanisms, tumors can impair the host immune cells within the TME and escape their surveillance. Within the TME, cells of the innate (e.g., macrophages, mast cells, neutrophils) and the adaptive (e.g., lymphocytes) immune responses are interconnected with epithelial cancer cells, fibroblasts, and endothelial cells via cytokines, chemokines, and adipocytokines. The molecular pattern of cytokines and chemokines has a key role and could explain the involvement of the immune system in tumor initiation and progression. Thyroid cancer-related inflammation is an important target for diagnostic procedures and novel therapeutic strategies. Anticancer immunotherapy, especially immune checkpoint inhibitors, unleashes the immune system and activates cytotoxic lymphocytes to kill cancer cells. A better knowledge of the molecular and immunological characteristics of TME will allow novel and more effective immunotherapeutic strategies in advanced thyroid cancer.

PGC-1α activator-induced fatty acid oxidation in tumor-infiltrating CTLs enhances effects of PD-1 blockade therapy in lung cancer

PURPOSE

The present study aims to investigate the efficacy and mechanisms of peroxisome proliferator-activated receptor γ coactivator 1-α agonist, as adjuvant to programmed death-1 (PD-1) blockade in hyporesponsive lung cancer cells-derived in vivo tumor model, using bezafibrate.

METHODS

Mouse Lewis lung carcinoma (LLC) xenograft models were established and treated with programmed death-ligand 1 (PD-L1) monoclonal antibodies with or without bezafibrate. Tumors or peripheral blood of mice were harvested to investigate the quality, quantity, and function as well as energetic metabolism of cytotoxic T lymphocytes (CTLs) by flow cytometry or quantitative real-time polymerase chain reaction.

RESULTS

The combination of bezafibrate plus anti-PD-L1 reached synergistic tumoricidal effect in LLC xenograft mouse models, even though bezafibrate alone had no effect on tumor growth. Bezafibrate significantly facilitated CD8+ T cells infiltrating into tumor tissues by enhancing the expression of CXCL9 and CXCL10 within tumors as well as the receptor CXCR3 in infiltrating CTLs. Activated CTLs within tumors were also significantly upregulated by bezafibrate. Further data demonstrated that bezafibrate treatment could maintain the survival and functional capacity of tumor-infiltrating CTLs. Moreover, cellular reactive oxygen species in infiltrating CTLs and fatty acid oxidation (FAO)-related genes (PGC-1α, Cpt1a, and LCAD) expression within tumors were significantly increased after treatment with bezafibrate.

CONCLUSIONS

Bezafibrate synergized the tumoricidal effect of PD-1 blockade in hyporesponsive lung cancer by expansion of effector CTLs within tumor microenvironment. The potential mechanism may relate to the capacity of bezafibrate in regulating FAO of tumor-infiltrating CTLs.

Combining Radiation and Immune Checkpoint Blockade in the Treatment of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a significant cause of morbidity and mortality worldwide. Current treatment options, even though potentially curative, have many limitations including a high rate of complications. Over the past few years immune checkpoint inhibitors (ICI) targeting cytotoxic lymphocyte antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death ligand 1 (PD-L1) have changed treatment paradigms in many malignancies and are currently under investigation in HNSCC as well. Despite improvements in treatment outcomes and the implementation of combined modality approaches long-term survival rates in patients with locally advanced HNSCC remain suboptimal. Accumulating evidence suggests that under certain conditions, radiation may be delivered in conjunction with ICI to augment efficacy. In this review, we will discuss the immune modulating mechanisms of ICI and radiation, how changing the dose, fractionation, and field of radiation may alter the tumor microenvironment (TME), and how these two treatment modalities may work in concert to generate durable treatment responses against HNSCC.