Non-Coding RNAs as Biomarkers for Early Detection and Prognosis of Colorectal Cancer: The Role of miRNAs and lncRNAs

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and one of the leading causes of cancer-related deaths worldwide. Early detection and precise diagnosis are crucial for improving the prognosis and survival rates of CRC patients. Molecular diagnostics have emerged as indispensable tools in identifying genetic, epigenetic, and transcriptomic changes associated with CRC. Among the most promising molecular markers for CRC detection are microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). These non-coding RNAs play critical roles in tumorgenesis, progression, and metastasis, making them invaluable for diagnostic, prognostic, and therapeutic applications. MicroRNAs are small, non-coding RNA molecules that regulate gene expression post-transcriptionally. In CRC, numerous miRNAs have been identified as either tumor suppressors or oncogenes. For instance, downregulation of miR-۱۴۳ and miR-۱۴۵, both known tumor suppressors, is frequently observed in CRC, leading to enhanced tumor growth and progression. On the other hand, over expression of oncogenic miRNAs, such as miR-۲۱, is associated with increased tumor invasiveness and poor patient prognosis. miR-۲۱ has been extensively studied as a potential biomarker for early CRC detection due to its high expression levels in serum and tissue samples. Furthermore, circulating miRNAs, which are stable and detectable in bodily fluids, offer non-invasive diagnostic methods. This makes miRNAs particularly attractive candidates for liquid biopsies, enabling real-time monitoring of disease progression and therapeutic responses. Long non-coding RNAs (lncRNAs) are another class of non-coding RNAs that play significant roles in gene regulation and chromatin remodeling. In CRC, several lncRNAs have been identified to be aberrantly expressed and associated with tumor development and metastasis. For example, the lncRNA HOTAIR is overexpressed in CRC and is linked to poor prognosis and increased metastasis. Similarly, lncRNA MALAT۱ has been implicated in promoting cell proliferation and invasion. These lncRNAs can serve as biomarkers for early CRC detection and offer insight into disease progression and patient outcomes. Additionally, lncRNAs such as GAS۵ and MEG۳, which act as tumor suppressors, are often downregulated in CRC, providing further diagnostic value. Recent advances in next-generation sequencing (NGS) technologies have significantly facilitated the identification and profiling of miRNAs and lncRNAs in CRC. NGS allows comprehensive analysis of non-coding RNAs, enabling the discovery of novel biomarkers and therapeutic targets. Moreover, combining miRNA and lncRNA signatures with other molecular markers, such as gene mutations (e.g., KRAS, BRAF) and microsatellite instability (MSI), enhances the accuracy and specificity of CRC diagnosis. In conclusion, miRNAs and lncRNAs represent promising molecular markers for the diagnosis and prognosis of colorectal cancer. Their stability, specificity, and involvement in key oncogenic pathways make them ideal candidates for non-invasive diagnostics and personalized treatment strategies. Future research should focus on validating these biomarkers in clinical settings and exploring their potential for targeted therapies, ultimately improving the management of CRC.

کلیدواژه ها:

CRC ، miRNA ، lncRNA ، molecular diagnosis