Nayeralsadat Fatemi

Colorectal cancer (CRC) is still one of the most common cancers and a leading cause of cancer morbidity worldwide. A significant issue that should be paid much attention to is its resistance to anticancer agents. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), have been identified as important regulators of drug response and drug resistance in CRC. In this review, we provide a comprehensive assessment of the studies conducted in the field of investigating the role of ncRNAs in drug resistance to prominent anticancer agents used in CRC, including 5-fluorouracil (5-FU), oxaliplatin, cetuximab, bevacizumab, and regorafenib. We focussed specifically on the miRNAs, lncRNAs, and circRNAs associated with resistance to each drug individually, even within the context of combination therapies, such as FOLFOX. We also reviewed competing endogenous RNA (ceRNAs) networks and their relationship with drug sensitivity and resistance and new therapeutic strategies to manage drug resistance in CRC and also analyzed the role of ceRNA networks in modulating drug response and its implications for new approaches to overcome drug resistance in CRC. This article also discusses findings from human clinical trials, highlighting evidence from patient studies that validate the role of targeting ceRNA and ncRNA networks in improving drug sensitivity, overcoming resistance, and enhancing therapeutic outcomes in CRC. It supports the targeting of ncRNA and ceRNA networks as potential therapies to improve treatment outcomes and drug resistance in CRC.

Colorectal cancer (CRC) is the second cause of cancer-related deaths in both sexes globally and presents different clinical outcomes that are described by a range of genomic and epigenomic alterations. Despite the advancements in CRC screening plans and treatment strategies, the prognosis of CRC is dismal. In the last two decades, molecular biomarkers predictive of prognosis have been identified in CRC, although biomarkers predictive of treatment response are only available for specific biological drugs used in stage IV CRC. Translational clinical trials mainly based on “omic” strategies allowed a better understanding of the biological heterogeneity of CRCs. These studies were able to classify CRCs into subtypes mainly related to prognosis, recurrence risk, and, to some extent, also to treatment response. Accordingly, the comprehensive molecular characterizations of CRCs, including The Cancer Genome Atlas (TCGA) and consensus molecular subtype (CMS) classifications, were presented to improve the comprehension of the genomic and epigenomic landscapes of CRCs for a better patient management. The CMS classification obtained by the CRC subtyping consortium categorizes CRC into four consensus molecular subtypes (CMS1–4) characterized by different prognoses. In this review, we discussed the CMS classification in different settings with a focus on its relationships with precursor lesions, tumor immunophenotype, and gut microbiota, as well as on its role in predicting prognosis and/or response to pharmacological treatments, as a crucial step towards precision medicine.