ABSTRACT
BACKGROUND: We previously reported overexpression of miR-3692-3p in the serum of non-small cell lung cancer patients. However, the expression profile and clinical utility of miR-3692-3p in the tumor tissues of lung cancer patients are not yet reported. METHODS AND RESULTS: We quantified the expression levels of miR-3692-3p in the tumors and adjacent normal lung tissues of early-stage (n = 29) and tissue biopsies of locally advanced and metastatic (n = 85) lung cancer patients using TaqMan advanced miRNA assay. We correlated miR-3692-3p expression with survival outcomes, therapeutic response, and other clinicopathological variables. We also predicted the target genes of miR-3692-3p, constructed a protein-protein interaction network, and performed functional enrichment analysis using various in silico tools. We found significant overexpression of miR-3692-3p in the tumors (Log2 fold change = 3.672; p < 0.0001) and tissue biopsies (Log2 fold change = 2.08; p = 0.0001) compared to normal lung tissues of lung cancer patients. The expression of miR-3692-3p did not correlate with overall survival (OS), progression-free survival (PFS), and response to therapy. In multivariate analysis, therapeutic response emerged as an independent prognostic biomarker of OS (HR = 3.47; p = 0.022) and PFS (HR = 19.86; p < 0.001). Our in silico analysis predicted 238 target genes of miR-3692-3p. CONCLUSIONS: Overexpression of miR-3692-3p could contribute to the development of lung cancer. However, mechanistic studies are warranted to shed further light on its role in lung carcinogenesis.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , MicroRNAs , Humans , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Gene Expression Regulation, Neoplastic/genetics , Lung Neoplasms/metabolism , MicroRNAs/metabolism , PrognosisABSTRACT
The presence of membranous immunopositivity of programmed death-ligand 1 (PD-L1) in tumors serves as a key determinant of response to immune checkpoint inhibitors. However, there are very limited studies on the evaluation of the PD-L1 mRNA expression and immunopositivity and their correlation with therapeutic response and survival outcomes, especially in Indian lung cancer patients. In this prospective study, conducted between 2017 and 2020, we collected biopsies and surgically resected tumors from 173 lung cancer patients. PD-L1 immunopositivity and mRNA expression were determined by immunohistochemistry using SP263 assay and qRT-PCR, respectively. PD-L1 expression was correlated with various clinicopathological variables, response to therapy, and survival outcomes using appropriate statistical methods. The median age was 60 years (range 33-81 years) with the majority of patients being male (86.5%) and smokers (83%). Histologically, the majority of patients were non-small cell lung cancer (89.4%) and of squamous cell carcinoma histology (64.3%). PD-L1 immunopositivity in tumor cells (tumor proportion score (TPS) ≥ 1%) was detected in 37.6%, while high immunopositivity (TPS ≥ 50%) was detected in 16.8% of lung cancer patients. Almost 76% of lung cancer patients with PD-L1 TPS ≥ 50% belonged to PD-L1 mRNA high-expression group. PD-L1 mRNA expression and immunopositivity did not correlate with response to therapy and survival outcomes. We conclude that PD-L1 immunopositivity and mRNA expression do not seem to serve as a prognostic biomarker for lung cancer patients treated with chemotherapy. More prospective studies should be planned to evaluate the predictive and prognostic relevance of PD-L1 expression in Indian lung cancer patients being treated with immune checkpoint inhibitors.
