Emerging roles of long non-coding RNA CASC2 in tumor chemoresistance - a review.

Malignant tumors remain a leading cause of global mortality, and the development of chemoresistance represents a major obstacle to effective cancer treatment. Long non-coding RNAs (lncRNAs) are important regulators of tumor progression and therapeutic response. Cancer susceptibility candidate 2 (CASC2) is an lncRNA that is generally downregulated in malignant tumors and has been implicated in the regulation of chemoresistance. CASC2 influences therapeutic responsiveness through multiple mechanisms, including modulation of apoptosis and oncogenic signaling pathways, competitive binding to specific miRNAs, regulation of protein stability and RNA-protein interactions, and epigenetic gene regulation. Notably, its effects may vary according to tumor type and treatment context. This review systematically summarizes the regulatory roles and molecular mechanisms of CASC2 in tumor chemoresistance and discusses its potential clinical and therapeutic implications.