Protein Expression of immune checkpoints STING and MHCII in small cell lung cancer

Molecular subtyping dictates therapeutic response to anti-PD-L1 immunotherapy in ES-SCLC

Anti-PD-L1 immunotherapy is recommended as standard of care for patients with extensive stage small cell lung cancer (ES-SCLC); however, there are no reliable biomarkers guiding patient selection and the survival benefit of PD-L1 inhibitors in the overall population is limited. In this study, we retrospectively analyzed a total number of 61 cases of ES-SCLC who underwent anti-PD-L1 immunotherapy. Patient demographic characteristics and laboratory findings were processed for univariate and multivariate analysis. Subgrouping of SCLC was performed on IHC platform using antibodies against ASCL1, NEUROD1 and POU2F3. The tumor microenvironment (TME) of ES-SCLC was evaluated by CD8 + T cell infiltration, granzyme B production and PD-L1 expression. We found limited efficacy of defined variable factors conferring therapeutic outcomes of anti-PD-L1 immunotherapy in patients with ES-SCLC. Intriguingly, there was a profound difference in TME and response to anti-PD-L1 immunotherapy when classifying SCLC into A/N/P/I subgroups. Although accounted for a small proportion of SCLC, the SCLC-P and SCLC-I subtypes manifested as T cell-enriched "hot" tumor and elicited more favorable response to immunotherapy, whereas the SCLC-A and SCLC-N subgroups were T cell-absent "cold" tumor. There was also a significant difference in progression free survival and overall survival across these subsets. Moreover, we found the SCLC-P and SCLC-I tumors revealed features of low neuroendocrine (NE) differentiation and showed clinicopathologic features overlapping with the SCLC non-NE lineage. These findings may aid clinicians to select ES-SCLC patients who were more likely to gain higher response rate and longer survival to anti-PD-L1 immunotherapy. Revisiting SCLC according to A/N/P/I subtyping and NE/non-NE differentiation is a reliable approach to guide therapeutic strategy in patients with ES-SCLC.

Expression of costimulatory molecule CD70 is prognostic in small cell lung cancer

INTRODUCTION

Small cell lung cancer (SCLC) is a highly aggressive malignancy with poor survival outcomes. The CD70-CD27 axis has been implicated in immune regulation and tumor progression across cancers, but its role in SCLC has not yet been elucidated. This research explores the expression patterns and prognostic significance of CD70 and CD27 in early-stage SCLC.

METHODS

In this retrospective study, we analyzed 190 surgically resected SCLC tumor samples using immunohistochemistry (IHC) for CD70 and CD27 expression and RNAscope for CD70 RNA detection. Immune infiltration was assessed using CD45, CD8, and CD20 staining. Quantification of RNAscope signals was performed using QPath software. Kaplan-Meier survival analysis and multivariate Cox regression were used to assess the prognostic impact of CD70, CD27, and immune cell infiltrates on overall survival (OS).

RESULTS

CD70 was expressed in 46% of tumors, primarily within tumor nests, with lower expression in stromal areas. High CD70 expression correlated with significantly decreased OS (p = 0.0078, HR: 1.795) without any correlation with CD45 + , CD8 + or CD20 + immune cell infiltrates. CD27 expression was mainly confined to the stroma, and it did not show a significant association with OS (p = 0.582). Importantly, high CD27 expression was linked to reduced CD45 + and CD8 + cell densities in the stroma. Both CD70 and CD27 were expressed on CD68 + macrophages, CD27 was expressed on CAFs, and both molecules exhibited a partial coexpression with CD3. Furthermore, patients with high CD20 + B-cell densities or the presence of tertiary lymphoid structures (TLS) had significantly improved OS (p = 0.0017, HR: 0.491), suggesting the importance of B-cell-related immune responses in SCLC prognosis.

CONCLUSION

CD70, B-cell density and the presence of TLSs, but not CD27, emerged as a significant prognostic biomarker for OS in surgically treated SCLC, suggesting its potential as a therapeutic target.

Dynamic STING repression orchestrates immune cell development and function

STING is an essential component of the innate immune system, yet homeostatic STING expression patterns and regulation are unknown. Using Sting1IRES-EGFP reporter and conditional Sting1 transgenic mice, we found that regulation of STING expression is critical for immune cell development and functionality. STING expression was repressed in neutrophils, and forced STING expression or signaling drove systemic inflammatory disease. During T lymphocyte development, STING expression was restricted at the double-positive stage via epigenetic silencing by DNA methyltransferase 1. Forced STING expression or signaling impaired T lymphocyte development independent of type I interferon and promoted lineage commitment to innate-like γδ T cells over adaptive αβ T cells. In the tumor microenvironment, CD8+ T lymphocytes repressed STING expression, correlating with features of T cell exhaustion in syngeneic mouse tumors and human colorectal cancer. Our data demonstrate the necessity of controlled, rather than ubiquitous, STING expression, uncovering a previously unappreciated dimension of STING pathobiology.

Stimulation of cGAS-STING pathway as a challenge in the treatment of small cell lung cancer: a feasible strategy?

Lung cancer has a significant incidence among the population and, unfortunately, has an unfavourable prognosis in most cases. The World Health Organization (WHO) classifies lung tumours into two subtypes based on their phenotype: the Non-Small Cell Lung Cancer (NSCLC) and the Small Cell Lung Cancer (SCLC). SCLC treatment, despite advances in chemotherapy and radiotherapy, is often unsuccessful for cancer recurrence highlighting the need to develop novel therapeutic strategies. In this review, we describe the genetic landscape and tumour microenvironment that characterize the pathological processes of SCLC and how they are responsible for tumour immune evasion. The immunosuppressive mechanisms engaged in SCLC are critical factors to understand the failure of immunotherapy in SCLC and, conversely, suggest that new signalling pathways, such as cGAS/STING, should be investigated as possible targets to stimulate an innate immune response in this subtype of lung cancer. The full comprehension of the innate immunity of cancer cells is thus crucial to open new challenges for successful immunotherapy in treating SCLC and improving patient outcomes.

Stimulator of Interferon Genes Protein (STING) Expression in Cancer Cells: A Tissue Microarray Study Evaluating More than 18,000 Tumors from 139 Different Tumor Entities

Stimulator of interferon genes protein (STING) activates the immune response in inflammatory cells. STING expression in cancer cells is less well characterized, but STING agonists are currently being evaluated as anticancer drugs. A tissue microarray containing 18,001 samples from 139 different tumor types was analyzed for STING by immunohistochemistry. STING-positive tumor cells were found in 130 (93.5%) of 139 tumor entities. The highest STING positivity rates occurred in squamous cell carcinomas (up to 96%); malignant mesothelioma (88.5%-95.7%); adenocarcinoma of the pancreas (94.9%), lung (90.3%), cervix (90.0%), colorectum (75.2%), and gallbladder (68.8%); and serous high-grade ovarian cancer (86.0%). High STING expression was linked to adverse phenotypes in breast cancer, clear cell renal cell carcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, and papillary carcinoma of the thyroid (p < 0.05). In pTa urothelial carcinomas, STING expression was associated with low-grade carcinoma (p = 0.0002). Across all tumors, STING expression paralleled PD-L1 positivity of tumor and inflammatory cells (p < 0.0001 each) but was unrelated to the density of CD8+ lymphocytes. STING expression is variable across tumor types and may be related to aggressive tumor phenotype and PD-L1 positivity. The lack of relationship with tumor-infiltrating CD8+ lymphocytes argues against a significant IFN production by STING positive tumor cells.

Tumor-associated macrophages affect the treatment of lung cancer

As one of the most common malignant tumors in the world, lung cancer has limited benefits for patients despite its diverse treatment methods due to factors such as personalized medicine targeting histological type, immune checkpoint expression, and driver gene mutations. The high mortality rate of lung cancer is partly due to the immune-suppressive which limits the effectiveness of anti-cancer drugs and induces tumor cell resistance. The currently widely recognized TAM phenotypes include the anti-tumor M1 and pro-tumor M2 phenotypes. M2 macrophages promote the formation of an immune-suppressive microenvironment and hinder immune cell infiltration, thereby inhibiting activation of the anti-tumor immune system and aiding tumor cells in resisting treatment. Analyzing the relationship between different treatment methods and macrophages in the TME can help us better understand the impact of TAMs on lung cancer and confirm the feasibility of targeted TAM therapy. Targeting TAMs to reduce the M2/M1 ratio and reverse the immune-suppressive microenvironment can improve the clinical efficacy of conventional treatment methods and potentially open up more efficient combination treatment strategies, maximizing the benefit for lung cancer patients.

Updates on lung neuroendocrine neoplasm classification

Lung neuroendocrine neoplasms (NENs) are a heterogeneous group of pulmonary neoplasms showing different morphological patterns and clinical and biological characteristics. The World Health Organisation (WHO) classification of lung NENs has been recently updated as part of the broader attempt to uniform the classification of NENs. This much-needed update has come at a time when insights from seminal molecular characterisation studies revolutionised our understanding of the biological and pathological architecture of lung NENs, paving the way for the development of novel diagnostic techniques, prognostic factors and therapeutic approaches. In this challenging and rapidly evolving landscape, the relevance of the 2021 WHO classification has been recently questioned, particularly in terms of its morphology-orientated approach and its prognostic implications. Here, we provide a state-of-the-art review on the contemporary understanding of pulmonary NEN morphology and the potential contribution of artificial intelligence, the advances in NEN molecular profiling with their impact on the classification system and, finally, the key current and upcoming prognostic factors.

Major histocompatibility complex class II in the tumor microenvironment: functions of nonprofessional antigen-presenting cells

Major histocompatibility complex class-II-restricted presentation by nonprofessional antigen-presenting cells in the tumor microenvironment can regulate antitumor T-cell responses. In murine models, tumor cell-specific MHC class II expression decreases in vivo tumor growth, dependent on T cells. Tumor cell-specific MHC class II expression is associated with improved survival and response to immune checkpoint inhibitors in human cancers. Antigen-presenting cancer-associated fibroblasts (apCAF) present MHC class-II-restricted antigens and activate CD4 T cells. The role of MHC class II on apCAFs depends on the cell of origin. MHC class II on tumoral lymphatic endothelial cells leads to expansion of regulatory T cells and increased in vivo tumor growth.

Canadian Consensus Recommendations on the Management of Extensive-Stage Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive, neuroendocrine tumour with high relapse rates, and significant morbidity and mortality. Apart from advances in radiation therapy, progress in the systemic treatment of SCLC had been stagnant for over three decades despite multiple attempts to develop alternative therapeutic options that could improve responses and survival. Recent promising developments in first-line and subsequent therapeutic approaches prompted a Canadian Expert Panel to convene to review evidence, discuss practice patterns, and reach a consensus on the treatment of extensive-stage SCLC (ES-SCLC). The literature search included guidelines, systematic reviews, and randomized controlled trials. Regular meetings were held from September 2022 to March 2023 to discuss the available evidence to propose and agree upon specific recommendations. The panel addressed biomarkers and histological features that distinguish SCLC from non-SCLC and other neuroendocrine tumours. Evidence for initial and subsequent systemic therapies was reviewed with consideration for patient performance status, comorbidities, and the involvement and function of other organs. The resulting consensus recommendations herein will help clarify evidence-based management of ES-SCLC in routine practice, help clinician decision-making, and facilitate the best patient outcomes.

Increased TIM-3 expression in tumor-associated macrophages predicts a poorer prognosis in non-small cell lung cancer: a retrospective cohort study

Background

T-cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) is considered a key negative regulator in T-cell-mediated response. However, few studies have been reported on the relationship between TIM-3 expression in tumor-associated macrophages (TAMs) and clinicopathological characteristics of patients. This study evaluated the correlation between the expression of TIM-3 on the surface of TAMs macrophages in tumor matrix and the clinical outcome of patients with non-small cell lung cancer (NSCLC).

Methods

The expression of CD68, CD163 and TIM-3 in 248 NSCLC patients who underwent surgery in Zhoushan Hospital from January 2010 to January 2013 was detected by immunohistochemistry (IHC). From the date of operation to the date of death, overall survival (OS) was measured to analyze the relationship between the expression of Tim-3 and the prognosis of NSCLC patients.

Results

The study assessed 248 patients with NSCLC. TIM-3 expression in TAMs was more frequently identified in patients with higher carcinoembryonic antigen (CEA) levels, lymph node metastasis, higher grade, high CD68 expression, and high CD163 expression (P<0.05). The OS of the high TIM-3 expression groups was shorter than that of the low TIM-3 expression groups (P=0.01). Patients with high TIM-3 and CD68/CD163 expressions had the worst prognosis, whereas patients with low expressions of both TIM-3 and CD68/CD163 had the best prognosis (P<0.05). In NSCLC, the OS of the high TIM-3 expression groups was shorter than that of the low TIM-3 expression groups (P=0.01). In lung adenocarcinoma, the OS of the high TIM-3 expression groups was shorter than that of the low TIM-3 expression groups(P=0.03).

Conclusions

TIM-3 expression in TAMs may be a promising prognostic biomarker for NSCLC or adenocarcinoma. Our results demonstrated that high TIM-3 expression in TAMs was an independent predictor of worse prognosis in patients.

NEUROD1 predicts better prognosis in pancreatic cancer revealed by a TILs-based prognostic signature

It has been well-defined that tumor-infiltrating lymphocytes (TILs) play critical roles in pancreatic cancer (PaCa) progression. This research aimed to comprehensively explore the composition of TILs in PaCa and their potential clinical significance. A total of 178 samples from the TCGA and 63 samples from the GSE57495 dataset were enrolled in our study. ImmuCellAI was applied to calculate the infiltrating abundance of 24 immune cell types in PaCa and further survival analysis revealed the prognostic values of TILs in PaCa. Moreover, the Hallmark enticement analysis of differentially expressed genes (DEGs) between low- and high-risk groups was performed as well. Immunohistochemistry staining was used to evaluate NEUROD1 expression. As result, different kinds of TILs had distinct infiltrating features. In addition, Specific TILs subsets had notable prognostic values in PaCa. We further established a 6-TILs signature to assess the prognosis of PaCa patients. Kaplan-Meier and Cox regression analyses both suggested the significant prognostic value of the signature in PaCa. Based on the prognostic signature, we screened a great deal of potential prognostic biomarkers and successfully validated NEUROD1 as a novel prognostic biomarker in PaCa. Overall, the current study illuminated the immune cells infiltrating the landscape in PaCa and identified a TILs-dependent signature and NEUROD1 for prognostic prediction in PaCa patients.

STING pathway contributes to the prognosis of hepatocellular carcinoma and identification of prognostic gene signatures correlated to tumor microenvironment

Background

Hepatocellular carcinoma (HCC) is one of the most malignant solid tumors worldwide. Recent evidence shows that the stimulator of interferon genes (STING) pathway is essential for anti-tumor immunity via inducing the production of downstream inflammatory cytokines. However, its impact on the prognosis and tumor microenvironment of HCC was still limited known.

Methods

We obtained gene expression profiles of HCC from GEO, TCGA, and ICGC databases, and immune-related genes (IRGs) from the ImmPort database. Multivariate Cox regression was performed to identify independent prognostic factors. Nomogram was established to predict survival probability for individual patients. Kaplan–Meier curve was used to evaluate the survival difference. Afterward, ESTIMATE, TISCH, and TIMER databases were combined to assess the immune cell infiltration. Furthermore, the qPCR, western blotting, and immunohistochemistry were done to evaluate gene expression, and in vitro cell models were built to determine cell migratory ability.

Results

We found that gene markers of NLRC3, STING1, TBK1, TRIM21, and XRCC6 within STING pathway were independent prognostic factors in HCC patients. Underlying the finding, a predictive nomogram was constructed in TCGA-training cohort and further validated in TCGA-all and ICGC datasets, showing credible performance. Experimentally, up-regulated TBK1 promotes the ability of HCC cell migration. Next, the survival-related immune-related co-expressed gene signatures (IRCGS) (VAV1, RHOA, and ZC3HAV1) were determined in HCC cohorts and their expression was verified in human HCC cells and clinical samples. Furthermore, survival-related IRCGS was associated with the infiltration of various immune cell subtypes in HCC, the transcriptional expression of prominent immune checkpoints, and immunotherapeutic response.

Conclusion

Collectively, we constructed a novel prognostic nomogram model for predicting the survival probability of individual HCC patients. Moreover, an immune-related prognostic gene signature was determined. Both might function as potential therapeutic targets for HCC treatment in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02734-4.