Upper gastrointestinal malignancies in 2017: current perspectives and future approaches

How many Italian cancer patients are eligible for, and may respond to, Italian Medicines Agency-approved immune checkpoint inhibitors?

INTRODUCTION

This cross-sectional study was aimed at estimating the number of Italian incident cancer patients in 2020 eligible for, and respondent to, immune checkpoint inhibitors (ICI).

METHODS

The study is based on publicly available data: the ICI approved until August 2022 by the Italian Medicines Agency (AIFA) with their specific indications and overall observed responses, rther details can be found in the Online Supplementary Materi cancer incidence estimates at 2020 and observed cancer deaths, and published papers with estimates on the frequency of different cancer stage/histology/markers etc. corresponding to AIFA authorizations.

RESULTS

In the analyzed period, a total of seven ICI were authorized in Italy for 20 cancer types. The estimated number of ICI-eligible patients in 2020 was 48,400, 14.3% of those tumors (including skin epitheliomas) that may fit AIFA-indications, and 10.5% of all the incident malignant tumors, including skin epitheliomas. The number of patients who may benefit from ICI therapy was 24,052, 49.7% of the ICI-eligible ones, or 5.2% of the overall estimated incident cancers in 2020.

CONCLUSIONS

In conclusion, although the number of ICI-eligible patients is a relatively small proportion of the yearly burden of cancers, about half of them may respond to ICI-treatment.

Transmembrane protein 176B regulates amino acid metabolism through the PI3K-Akt-mTOR signaling pathway and promotes gastric cancer progression

BACKGROUND

The present study aimed to investigate the expression level, biological function, and underlying mechanism of transmembrane protein 176B (TMEM176B) in gastric cancer (GC).

METHODS

TMEM176B expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB). The function of TMEM176B was determined by various in vitro assays including colony formation, 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and flow cytometry. Bioinformatics techniques were then used to elucidate the signaling pathways associated with TMEM176B activity. Tumor formation experiments were conducted on nude mice for in vivo validation of the preceding findings. TMEM176B expression was cross-referenced to clinicopathological parameters and survival outcomes.

RESULTS

It was observed that TMEM176B was overexpressed in GC cells and tissues. Targeted TMEM176B abrogation inhibited colony formation, proliferation, migration, and invasion but promoted apoptosis in GC cell lines while TMEM176B overexpression had the opposite effects. Subsequent experimental validation disclosed an association between TMEM176B and the phosphatidylinositol 3-carboxykinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling axis. Moreover, TMEM176B affects GC cancer progression by regulating asparagine synthetase (ASNS). The in vivo assays confirmed that TMEM176B is oncogenic and the clinical data revealed a connection between TMEM176B expression and the clinicopathological determinants of GC.

CONCLUSION

The foregoing results suggest that TMEM176B significantly promotes the development of gastric cancer and is an independent prognostic factor of it.

Identification and characterization of CLEC11A and its derived immune signature in gastric cancer

Introduction

C-type lectin domain family 11 member A (CLEC11A) was characterized as a growth factor that mainly regulates hematopoietic function and differentiation of bone cells. However, the involvement of CLEC11A in gastric cancer (GC) is not well understood.

Methods

Transcriptomic data and clinical information pertaining to GC were obtained and analyzed from publicly available databases. The relationships between CLEC11A and prognoses, genetic alterations, tumor microenvironment (TME), and therapeutic responses in GC patients were analyzed by bioinformatics methods. A CLEC11A-derived immune signature was developed and validated, and its mutational landscapes, immunological characteristics as well as drug sensitivities were explored. A nomogram was established by combining CLEC11A-derived immune signature and clinical factors. The expression and carcinogenic effects of CLEC11A in GC were verified by qRT-PCR, cell migration, invasion, cell cycle analysis, and in vivo model analysis. Myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), M2 macrophages, and T cells in tumor samples extracted from mice were analyzed utilizing flow cytometry analysis.

Results

CLEC11A was over-expressed in GC, and the elevated CLEC11A expression indicated an unfavorable prognosis in GC patients. CLEC11A was involved in genomic alterations and associated with the TME in GC. Moreover, elevated CLEC11A was found to reduce the benefit of immunotherapy according to immunophenoscore (IPS) and the tumor immune dysfunction, exclusion (TIDE). After validation, the CLEC11A-derived immune signature demonstrated a consistent ability to predict the survival outcomes in GC patients. A nomogram that quantifies survival probability was constructed to improve the accuracy of prognosis prediction in GC patients. Using shRNA to suppress the expression of CLEC11A led to significant inhibitions of cell cycle progression, migration, and invasion, as well as a marked reduction of in vivo tumor growth. Moreover, the flow cytometry assay showed that the knock-down of CLEC11A increased the infiltration of cytotoxic CD8+ T cells and helper CD4+ T into tumors while decreasing the percentage of M2 macrophages, MDSCs, and Tregs.

Conclusion

Collectively, our findings revealed that CLEC11A could be a prognostic and immunological biomarker in GC, and CLEC11A-derived immune signature might serve as a new option for clinicians to predict outcomes and formulate personalized treatment plans for GC patients.

Therapeutic Immunomodulation in Gastric Cancer

Gastric carcinoma, being one of the most prevalent types of solid tumors, has emerged as the third leading cause of death worldwide. The symptoms of gastric cancer (GC) are typically complex, which makes early detection challenging. Immune checkpoint inhibition has become the new standard targeted therapy for advanced or metastatic GC. It is currently being explored in various combinations, both with and without chemotherapy, across multiple therapies in clinical trials. Immunotherapy can stimulate immune responses in GC patients, leading to the destruction of cancer cells. Compared with traditional therapies, immunotherapy has shown strong effectiveness with tolerable toxicity levels. Hence, this innovative approach to the treatment of advanced GC has gained popularity. In this review, we have outlined the recent advancements in immunotherapy for advanced GC, including immune checkpoint inhibitors, cancer vaccines, vascular endothelial growth factor-A inhibitors, and chimeric antigen receptor T-cell therapy. Our current emphasis is on examining the immunotherapies presently employed in clinical settings, addressing the existing challenges associated with these therapeutic approaches, and exploring promising strategies to overcome their limitations.

Biomarkers for response to immune checkpoint inhibitors in gastrointestinal cancers

Gastrointestinal (GI) cancers account for a large proportion of cancer deaths worldwide and pose a major public health challenge. Immunotherapy is considered to be one of the prominent and successful approaches in cancer treatment in recent years. Among them, immune checkpoint inhibitor (ICI) therapy, has received widespread attention, and many clinical findings support the feasibility of ICIs, with sustained responses and significantly prolonged lifespan observed in a wide range of tumors. However, patients treated with ICIs have not fully benefited, and therefore, the identification and development of biomarkers for predicting ICI treatment response have received further attention and exploration. From tumor genome to molecular interactions in the tumor microenvironment, and further expanding to circulating biomarkers and patient characteristics, the exploration of biomarkers is evolving with high-throughput sequencing as well as bioinformatics. More large-scale prospective and specific studies are needed to explore biomarkers in GI cancers. In this review, we summarize the known biomarkers used in ICI therapy for GI tumors. In addition, some ICI biomarkers applied to other tumors are included to provide insights and further validation for GI tumors. Moreover, we present single-cell analysis and machine learning approaches that have emerged in recent years. Although there are no clear applications yet, it can be expected that these techniques will play an important role in the application of biomarker prediction.

Advances in clinical immunotherapy for gastric cancer

Gastric cancer (GC) is one of the most malignant human cancers with increasing incidence worldwide, ranking among the top five malignant tumors worldwide in terms of incidence and mortality. The clinical efficacy of conventional therapies is limited, and the median overall survival (mOS) for advanced-stage gastric cancer is only about 8 months. Emerging as one of breakthroughs for cancer therapy, immunotherapy has become an effective treatment modality after surgery, chemotherapy, radiotherapy, and targeted therapy. In this review, we have summarized the progresses of clinical development of immunotherapies for gastric cancer. Major advances with immune checkpoint inhibitors (ICIs) have started to change the clinical practice for gastric cancer treatment and prognosis. Additionally, combination therapies with other modalities, such as targeted therapies, are expected to push immunotherapies to front-line. In this review, the efficacy of ICIs and targeted therapy alone or combination with existing therapies gastric cancer treatment was described and the predictive value of biomarkers for immunotherapies in gastric cancer treatment is also discussed.

The combined expressions of B7H4 and ACOT4 in cancer-associated fibroblasts are related to poor prognosis in patients with gastric carcinoma

B7H4 is a member of the B7 family, which is expressed on antigen-presenting cells (APCs) and which negatively regulates the immune response of T cells through the inhibition of their proliferation, cytokine production, and cell cycle progression. Acyl-CoA thioesterase 4 (ACOT4) is an isoform of the ACOTs family that catalyzes the hydrolysis of fatty acyl-CoA to CoA-SH and free fatty acids. An abnormal metabolism of lipids and fatty acids is observed during tumor progression. In our study, a tissue microarray was constructed from 288 cases of gastric adenocarcinoma (GC). ACOT4 expression in cancer-associated fibroblasts (CAFs) and B7H4 expression in cancer tissues were analyzed by immunohistochemistry. The correlations among B7H4 in GC cells, ACOT4 in CAFs, and survival were analyzed. The results showed that the expression rate of B7H4 in tumor cells and ACOT4 in CAFs in 288 tissues was 71.9% (207/288) and 26.4% (76/288), respectively, and a Kaplan-Meier survival analysis showed that a low expression of ACOT4 in fibroblasts was positively correlated with poor survival. However, in a subgroup showing a high ACOT4 expression, the overall survival rate was associated with a high expression of B7H4 and correlated with poor prognosis in GC. In conclusion, ACOT4 expression in CAFs could be an independent prognostic factor for GC patients, and the co-expression with B7H4 in cancer tissues was significantly correlated with GC patients' prognosis. This evidence can represent a comprehensive prediction and a targeted therapy for gastric cancer patients. Tumor immunotherapy targeting might be affected by tumor microenvironment metabolism.