Predictive Value of Excision Repair Cross-Complementation Group 1 in the Response to Platinum-Based Chemotherapy in Esophageal Cancer: A Meta-Analysis

Long noncoding RNAs as potential targets for overcoming chemoresistance in upper gastrointestinal cancers

In the last decade, researchers have paid much attention to the role of noncoding RNA molecules in human diseases. Among the most important of these molecules are LncRNAs, which are RNA molecules with a length of more than 200 nucleotides. LncRNAs can regulate gene expression through various mechanisms, such as binding to DNA sequences and interacting with miRNAs. Studies have shown that LncRNAs may be valuable therapeutic targets in treating various cancers, including upper-gastrointestinal cancers. Upper gastrointestinal cancers, mainly referring to esophageal and gastric cancers, are among the deadliest gastrointestinal cancers. Despite notable advances, traditional chemotherapy remains a common strategy for treating these cancers. However, chemoresistance poses a significant obstacle to the effective treatment of upper gastrointestinal cancers, resulting in a low survival rate. Chemoresistance arises from various events, such as the enhancement of efflux and detoxification of chemotherapy agents, reduction of drug uptake, alteration of drug targeting, reduction of prodrug activation, strengthening of EMT and stemness, and the attenuation of apoptosis in cancerous cells. Tumor microenvironment also plays an important role in chemoresistance. Interestingly, a series of studies have revealed that LncRNAs can influence important mechanisms associated with some of the aforementioned events and may serve as promising targets for mitigating chemoresistance in upper gastrointestinal cancers. In this review paper, following a concise overview of chemoresistance mechanisms in upper gastrointestinal cancers, we will review the most intriguing findings of these investigations in detail.

Bioinformatics analysis of ERCC family in pan-cancer and ERCC2 in bladder cancer

Background

Single nucleotide polymorphisms (SNPs) in DNA repair genes can impair protein function and hinder DNA repair, leading to genetic instability and increased cancer risk. The Excision Repair Cross-Complementation (ERCC) family plays a crucial role in nucleotide excision repair, yet their comprehensive multi-omics characterization and roles in tumor prognosis and immune microenvironment remain unexplored.

Methods and materials

We performed bioinformatics analysis using publicly available data from 33 cancer types to investigate associations between ERCC gene expression, patient prognosis, and clinical features. We also validated the role of ERCC2 in bladder cancer through in vitro assays, including CCK-8, colony formation, wound healing, and Transwell assays.

Results

By utilizing the most recent database, we have conducted an analysis that reveals associations between variations in ERCC expression across multiple cancer types and both patient prognosis and the tumor microenvironment. To ensure the reliability of our findings, we applied the Benjamini-Hochberg procedure to adjust for multiple testing. After correction, we identified that ERCC expression levels remained significantly correlated with patient prognosis in various cancer types (p < 0.05). In addition, according to the results of drug sensitivity studies of anticancer drugs, there is a large correlation between ERCC expression and the sensitivity of different anticancer drugs. Finally, in vitro cell behavioral assays determined that knockdown of ERCC2 gene expression significantly inhibited the proliferation, migration and invasion of bladder cancer cells.

Conclusion

Through in-depth exploration of ERCC differential expression and its correlation with immune-related indicators, the unique microenvironment of tumors, and patient prognosis, we verified the potential role of ERCC2 in the process of bladder cancer genesis and progression. Therefore, we believe that the ERCC family of genes is expected to be a new option for cancer treatment and deserves to be further explored in the future.

Potent molecular-targeted therapies for advanced esophageal squamous cell carcinoma

Esophageal cancer (EC) remains a public health concern with a high mortality and disease burden worldwide. Esophageal squamous cell carcinoma (ESCC) is a predominant histological subtype of EC that has unique etiology, molecular profiles, and clinicopathological features. Although systemic chemotherapy, including cytotoxic agents and immune checkpoint inhibitors, is the main therapeutic option for recurrent or metastatic ESCC patients, the clinical benefits are limited with poor prognosis. Personalized molecular-targeted therapies have been hampered due to the lack of robust treatment efficacy in clinical trials. Therefore, there is an urgent need to develop effective therapeutic strategies. In this review, we summarize the molecular profiles of ESCC based on the findings of pivotal comprehensive molecular analyses, highlighting potent therapeutic targets for establishing future precision medicine for ESCC patients, with the most recent results of clinical trials.

Molecular tests for prediction of tumor sensitivity to cytotoxic drugs

Chemotherapy constitutes the backbone of cancer treatment. Several predictive assays assist personalized administration of cytotoxic drugs and are recommended for use in a clinical setting. The deficiency of DNA repair by homologous recombination (HRD), which is caused by inactivation of BRCA1/2 genes or other genetic events, is associated with high tumor responsiveness to platinum compounds, bifunctional alkylating agents and topoisomerase II poisons. Low activity of MGMT predicts the efficacy of nitrosoureas and tetrazines. Some clinically established pharmacogenetic tests allow for the adjustment of drug dosage, for example, the analysis of DPYD allelic variants for administration of fluoropyrimidines and UGT1A1 genotyping for the use of irinotecan. While there are promising molecular predictors of tumor sensitivity to pemetrexed, gemcitabine and taxanes, they remain in the investigational stage and require additional validation. Comprehensive molecular analysis of tumors obtained from drug responders and non-responders is likely to reveal new clinically useful predictive markers for cytotoxic therapy.