High Expression of PSRC1 Predicts Poor Prognosis in Lung Adenocarcinoma

Exploring potential therapeutic targets for small cell lung cancer based on transcriptomics combined with Mendelian randomization analysis

Objective

The main objective of this study was to explore and identify new genetic targets in small-cell lung cancer (SCLC) through transcriptomics analysis and Mendelian randomization (MR) analysis, which will help in the subsequent development of new therapeutic interventions.

Methods

In this study, we extracted the SCLC dataset from the Gene Expression Omnibus (GEO) database, processed the data, and screened out differentially expressed genes (DEGs) using R software. Based on expression quantitative trait loci data and the genome-wide association study data of SCLC, MR analysis was used to screen the genes closely related to SCLC disease, which intersect with DEGs to obtain co-expressed genes (CEGs), and the biological functions and pathways of CEGs were further explored by enrichment analysis. In addition, the CIBERSORT algorithm was applied to assess the level of immune cell infiltration in SCLC and to analyze the correlation between CEGs and immune cells. Meanwhile, we performed a survival analysis on these five CEGs using an independent cohort of SCLC patients. Finally, the results for the target genes were validated.

Results

In this study, 857 DEGs were identified, including 443 up-regulated and 414 down-regulated genes, and 5 CEGs (PSAT1, PSRC1, COLEC12, PLLP, HP) that were significantly associated with SCLC were identified through further intersecting. The results of enrichment analyses indicated that CEGs play important roles in several key functions and pathways. Immune-cell-related analysis revealed the unique distribution of immune cell infiltration in SCLC and the mechanism of immune cell regulation by CEGs. Survival analysis results indicated that PSRC1 was significantly correlated with the overall survival of SCLC, and the survival rate of the high-expression group was markedly lower than that of the low-expression group. Finally, the consistency of the results between the validation group analyses and MR analysis confirmed that the results of this study is reliable.

Conclusion

The CEGs and their associated functions and pathways screened in this study may be potential targets of therapeutic intervention in SCLC by targeting specific molecular pathways.

Assessing the benefits and safety profile of incorporating poly ADP-ribose polymerase (PARP) inhibitors in the treatment of advanced lung cancer: a thorough systematic review and meta-analysis

Background

Poly (ADP-Ribose) Polymerase (PARP) inhibitors represent a novel class of drugs that hinder DNA repair mechanisms in tumor cells, leading to cell death. This systematic review aims to evaluate the effectiveness, safety, and potential adverse effects of PARP inhibitors (PARPi) in the management of patients with advanced lung cancer.

Materials and Methods

We conducted a comprehensive search for relevant studies in PubMed, Embase, Cochrane, and ClinicalTrials.gov. We extracted primary and secondary outcome measures, including progression-free survival (PFS), overall survival (OS), and adverse events (AEs), from the identified literature for subsequent meta-analysis and systematic review.

Results

This study encompassed twelve randomized controlled trials, involving 3,132 patients with advanced lung cancer. In comparison to non-PARPi treatments, the administration of PARPi significantly extended OS (hazard ratio (HR) = 0.90, 95% CI = 0.83-0.97, p = 0.006). However, the difference in PFS did not reach statistical significance.

Conclusion

In summary, therapies incorporating PARPi provide a degree of benefit by extending OS in patients with advanced lung cancer. Nonetheless, further trials are necessary to furnish additional evidence regarding the efficacy and safety of PARPi in the treatment of lung cancer.

Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier number: CRD42023424673.

Expression of AhR-regulated miRNAs in non-small cell lung cancer in smokers and never smokers

Smoking is a risk factor for non-small cell lung cancer (NSCLC). The most common subtypes of NSCLC are lung adenocarcinoma (LAC) and squamous cell carcinoma (SCC). The cigarette smoke contains aryl hydrocarbon receptor (AhR) ligands, such as benzo(a)pyrene (BaP). By activating the AhR, BaP can change the expression of many genes, including miRNA-encoding genes. In this study, we have evaluated the expression of few miRNAs potentially regulated by AhR (miR-21, -342, -93, -181a, -146a), as well as CYP1A1, a known AhR target gene, in lung tumor samples from smoking (n=40) and non-smoking (n=30) patients with LAC and from smoking patients with SCC (n=40). We have also collected macroscopically normal lung tissue >5 cm from the tumor margin. We compared the obtained data on the miRNA expression in tumors with data from The Cancer Genome Atlas (TCGA). We found that in 76.7% of non-smoking LAC patients, CYP1A1 mRNA was not detected in tumor and normal lung tissues, while in smoking patients, CYP1A1 expression was detected in tumors in almost half of the cases (47.5% for SCC and 42.5% for LAC). The expression profile of AhR-regulated miRNAs differed between LAC and SCC and depended on the smoking status. In LAC patients, the expression of oncogenic miRNA-21 and miRNA-93 in tumors was higher than in normal lung tissue from the same patients. However, in SCC patients from our sample, the levels of these miRNAs in tumor and non-transformed lung tissue did not differ significantly. The results of our studies and TCGA data indicate that the expression levels of miRNA-181a and miRNA-146a in LAC are associated with smoking: expression of these miRNAs was significantly lower in tumors of smokers. It is possible that their expression is regulated by AhR and AhRR (AhR repressor), and inhibition of AhR by AhRR leads to a decrease in miRNA expression in tumors of smoking patients. Overall, these results confirm that smoking has an effect on the miRNA expression profile. This should be taken into account when searching for new diagnostic and therapeutic targets for NSCLC.