A novel DNA damage repair-related signature for predicting prognositc and treatment response in non-small lung cancer

Regulatory role of the miR-142-3p/CDC25C axis in modulating autophagy in non-small cell lung cancer

Background

With its diverse genetic foundation and heterogeneous nature, non-small cell lung cancer (NSCLC) needs a better comprehension of prognostic evaluation and efficient treatment targeting.

Methods

Bioinformatics analysis was performed of The Cancer Genome Atlas (TCGA)-NSCLC and GSE68571 dataset. Overlapping differentially expressed genes (DEGs) were used for functional enrichment analysis and constructing the protein-protein interaction (PPI) network. In addition, key prognostic genes were identified through prognostic risk models, and their expression levels were verified. The phenotypic effects of cell division cycle 25C (CDC25C) regulation on NSCLC cell lines were assessed by in vitro experiments using various techniques such as flow cytometry, Transwell, and colony formation. Protein levels related to autophagy and apoptosis were assessed, specifically examining the impact of autophagy inhibition [3-methyladenine (3-MA)] and the miR-142-3p/CDC25C axis on this regulatory system.

Results

CDC25C was identified as a key prognostic marker in NSCLC, showing high expression in tumor samples. In vitro experiments showed that CDC25C knockdown markedly reduced the capacity of cells to proliferate, migrate, invade, trigger apoptosis, and initiate cell cycle arrest. CDC25C and miR-142-3p displayed a reciprocal regulatory relationship. CDC25C reversed the inhibitory impacts of miR-142-3p on NSCLC cell cycle proliferation and progression. The synergy of miR-142-3p inhibition, CDC25C silencing, and 3-MA treatment was shown to regulate NSCLC cell processes including proliferation, apoptosis, and autophagy.

Conclusions

MiR-142-3p emerged as a key player in governing autophagy and apoptosis by directly targeting CDC25C expression. This emphasizes the pivotal role of the miR-142-3p/CDC25C axis as a critical regulatory pathway in NSCLC.

Expression of "DNA damage response" pathway genes in diffuse large B-cell lymphoma: The potential for exploiting synthetic lethality

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are two of the most prevalent non-Hodgkin's lymphoma subtypes. Despite advances, treatment resistance and patient relapse remain challenging issues. Our study aimed to scrutinize gene expression distinctions between DLBCL and FL, employing a cohort of 53 DLBCL and 104 FL samples that underwent rigorous screening for genetic anomalies. The NanoString nCounter assay evaluated 730 cancer-associated genes, focusing on densely tumorous areas in diagnostic samples. Employing the Lymph2Cx method, we determined the cell-of-origin (COO) for DLBCL cases. Our meticulous analysis, facilitated by Qlucore Omics Explorer software, unveiled a substantial 37% of genes with significantly differential expression patterns between DLBCL and FL, pointing to nuanced mechanistic disparities. Investigating the impact of FL disease stage and DLBCL COO on gene expression yielded minimal differences, prompting us to direct our attention to consistently divergent genes in DLBCL. Intriguingly, our Gene Set Enrichment Analysis spotlighted 21% of these divergent genes, converging on the DNA damage response (DDR) pathway, vital for cell survival and cancer evolution. Strong positive correlations among most DDR genes were noted, with key genes like BRCA1, FANCA, FEN1, PLOD1, PCNA, and RAD51 distinctly upregulated in DLBCL compared to FL and normal tissue controls. These findings were subsequently validated using RNA seq data on normal controls and DLBCL samples from public databases like The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) databases, enhancing the robustness of our results. Considering the established significance of these DDR genes in solid cancer therapies, our study underscores their potential applicability in DLBCL treatment strategies. In conclusion, our investigation highlights marked gene expression differences between DLBCL and FL, with particular emphasis on the essential DDR pathway. The identification of these DDR genes as potential therapeutic targets encourages further exploration of synthetic lethality-based approaches for managing DLBCL.

Cancer Cell-Intrinsic Alterations Associated with an Immunosuppressive Tumor Microenvironment and Resistance to Immunotherapy in Lung Cancer

Despite the great clinical success of immunotherapy in lung cancer patients, only a small percentage of them (<40%) will benefit from this therapy alone or combined with other strategies. Cancer cell-intrinsic and cell-extrinsic mechanisms have been associated with a lack of response to immunotherapy. The present study is focused on cancer cell-intrinsic genetic, epigenetic, transcriptomic and metabolic alterations that reshape the tumor microenvironment (TME) and determine response or refractoriness to immune checkpoint inhibitors (ICIs). Mutations in KRAS, SKT11(LKB1), KEAP1 and TP53 and co-mutations of these genes are the main determinants of ICI response in non-small-cell lung cancer (NSCLC) patients. Recent insights into metabolic changes in cancer cells that impose restrictions on cytotoxic T cells and the efficacy of ICIs indicate that targeting such metabolic restrictions may favor therapeutic responses. Other emerging pathways for therapeutic interventions include epigenetic modulators and DNA damage repair (DDR) pathways, especially in small-cell lung cancer (SCLC). Therefore, the many potential pathways for enhancing the effect of ICIs suggest that, in a few years, we will have much more personalized medicine for lung cancer patients treated with immunotherapy. Such strategies could include vaccines and chimeric antigen receptor (CAR) cells.