RNA Protein Complex Transforms Cancer Suppressor Into Tumor Promoter in Colorectal Cancer

This study reveals a sophisticated molecular mechanism that explains how cancer cells can hijack normal cellular processes to promote their own survival. The research focuses on colorectal cancer, one of the leading causes of cancer deaths worldwide.

The scientists discovered that RNA-binding protein RBM5 forms a complex with long non-coding RNA MGC32805 in a 'sandwich' configuration. This partnership fundamentally alters how the FAS gene is processed during protein production through alternative splicing.

Normally, FAS produces mFAS, a protein that promotes cancer cell death (apoptosis). However, when RBM5 and MGC32805 work together, they cause the cellular machinery to skip exon 6 during gene processing, creating ΔFAS instead - a variant that actually helps cancer cells survive and resist chemotherapy drugs like 5-Fluorouracil.

The researchers identified specific molecular binding sites and amino acid residues responsible for these interactions, providing detailed insights into the mechanism. They demonstrated this process both in laboratory cancer cell cultures and in mouse models with human tumor transplants.

This discovery has significant implications for understanding cancer progression and developing new treatments. By revealing how tumor suppressor genes can be converted into oncogenes through RNA processing changes, the research opens new avenues for therapeutic intervention targeting these splicing mechanisms.