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BACKGROUND: Current evidence highlights clear cell renal carcinoma (ccRCC) as the most prevalent form of kidney cancer despite ongoing challenges in treating advanced-stage disease. Integrin subunit beta 3 (ITGB3) has recently emerged as a critical player in tumorigenesis, prompting our investigation into its role in ccRCC. This study aimed to elucidate the mechanisms responsible for ITGB3 downregulation and evaluate its clinical significance, particularly regarding its impact on the immune landscape within ccRCC. METHODS: We first conducted analyses utilizing data from both TCGA and GEO datasets to explore ITGB3 expression in ccRCC tissues. Subsequently, we evaluated the association between ITGB3 expression levels and patient prognosis and pathological staging. Pathway and functional enrichment analyses were performed to assess correlations between ITGB3 and immune and methylation-related pathways. Additionally, we examined the relationship between ITGB3 transcriptional expression and DNA hypermethylation. A prognostic risk model was developed using LASSO-based analysis on selected ITGB3-associated DNA methylation probes. Immunohistochemistry (IHC) analysis, alongside TIMER and ssGSEA results, was utilized to investigate ITGB3 expression and its association with immune cell infiltration. RESULTS: Our analyses revealed significant downregulation of ITGB3 mRNA expression in ccRCC tissues compared to other members of the ITGB family, consistent across TCGA and GEO datasets. Higher ITGB3 expression correlated with improved prognosis and lower pathological stage in ccRCC patients. Pathway and functional enrichment analyses demonstrated positive correlations between ITGB3 and immune and methylation-related pathways, while ITGB3 transcriptional expression showed a negative correlation with DNA hypermethylation. The established prognostic risk model identified a high-risk group with poorer survival probabilities than the low-risk group. Immunohistochemical quantification revealed a positive correlation between CD4+ and CD8+ immune cell infiltration and ITGB3 expression. CONCLUSION: Overall, our study provides compelling evidence supporting the significant role of ITGB3 in ccRCC immunity. The downregulation of ITGB3, coupled with its association with better prognosis and immune activation, suggests its potential as a therapeutic target and prognostic marker for this patient population.
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[This corrects the article DOI: 10.3389/fphar.2022.908882.].
ABSTRACT
Methylation is an important mechanism contributing to cancer pathology. Methylation of tumor suppressor genes and oncogenes has been closely associated with tumor occurrence and development. New insights regarding the potential role of the adenosine receptor-independent pathway in the epigenetic modulation of DNA methylation offer the possibility of new interventional strategies for cancer therapy. Targeting DNA methylation of cancer-related genes is a promising therapeutic strategy; drugs like 5-Aza-2'-deoxycytidine (5-AZA-CdR, decitabine) effectively reverse DNA methylation and cancer cell growth. However, current anti-methylation (or methylation modifiers) are associated with severe side effects; thus, there is an urgent need for safer and more specific inhibitors of DNA methylation (or DNA methylation modifiers). The adenosine signaling pathway is reported to be involved in cancer pathology and participates in the development of tumors by altering DNA methylation. Most recently, an adenosine metabolic clearance enzyme, adenosine kinase (ADK), has been shown to influence methylation on tumor suppressor genes and tumor development and progression. This review article focuses on recent updates on ADK and its two isoforms, and its actions in adenosine receptor-independent pathways, including methylation modification and epigenetic changes in cancer pathology.
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Background: Glutathione S-transferase mu 1 (GSTM1) is one of the major glutathione conjugation enzymes. Its expression and activity have been suggested to correlate with the occurrence of colon cancer; however, the role of GSTM1 in tumor immunity remains unclear. Methods: Relevant data downloaded from The Cancer Genome Atlas (TCGA), Clinical Proteomic Tumor Analysis Consortium (CPTAC), and Human Protein Atlas (HPA) was used to perform a multi-dimensional expression analysis of GSTM1 in colon adenocarcinoma (COAD). The correlation between GSTM1 and tumor immunity was analyzed with multiple online tools. Then protein-protein interaction (PPI) network and functional enrichment analyses of GSTM1-associated immunomodulators were performed. Further, we developed the Cox regression model based on the GSTM1-related immunomodulators. Finally, a GSTM1-based clinical nomogram and a calibration curve was established to predict the probability and accuracy of long-term survival. Result: GSTM1 was significantly downregulated in COAD versus normal tissues. Infiltration levels of B cells, CD8+ T cells, and dendritic cells were closely correlated to GSTM1 gene copy number deletion, and GSTM1 expression levels in COAD positively correlated with dendritic cell, B cell, neutrophil, and macrophage infiltration. Functional enrichment analysis indicated 36 GSTM1-related immunomodulators are involved in immune-related pathways of regulating T cell activation and lymphocytic activation. A 2-gene prognostic risk signature based on the 36 GSTM1-related immunomodulators was built using the Cox regression model, and the risk signature in combination with stage had an area under the curve (AUC) value of 0.747 by the receiver operating characteristic method. patients with higher risk scores-calculated based on 2 gene prognostic risk characteristics and further identified as an independent prognostic factor-were associated with worse survival using the Kaplan-Meier analysis. Together, the clinical nomogram and calibration curve based on GSTM1 suggested a good prediction accuracy for long-term survival probability. Conclusions: Our study provided evidence supporting the significant role of GSTM1 in COAD immunity and suggests GSTM1 as a potential novel target for COAD immunotherapy.