Long Non-coding RNA TPRG1-AS1 Interacts With CLTC in Liver Cancer Cells.

Background/aim: Certain long non-coding RNAs (lncRNAs), identified as potential tumor suppressors, have shown potential in inhibiting tumor growth. Here, we investigated a novel mechanism involving the direct interaction between lncRNA TPRG1-AS1 and Clathrin Heavy Chain (CLTC) in the Epidermal Growth Factor (EGF) signaling pathway for its tumor-suppressive effects.

Materials and methods: Our research revealed a direct physical interaction between TPRG1-AS1 and CLTC through RNA pulldown and RNA immunoprecipitation (RIP)-qPCR, which subsequently influenced the EGF signaling pathway. We confirmed phenotype changes by cell viability, sphere formation, and invasion. We confirmed the mechanism underlying these phenotypic changes through immunoblotting and immunocytochemistry.

Results: Firstly, we confirmed a reduction in the phenotype associated with the overexpression of TPRG1-AS1 (TPRG1-AS1oe) interacting with CLTC in the presence of EGF signaling. Next, it was observed that TPRG1-AS1oe suppressed EGF downstream signaling, specifically MAPK8 and MAPK14, in relation to CLTC. Moreover, we verified that overexpressed TPRG1-AS1 binds to CLTC and suppresses EGF downstream signaling using a custom HEX probe.

Conclusion: Collectively our study uncovered a novel regulatory axis wherein TPRG1-AS1 interacts with CLTC, consequently attenuating EGF downstream signaling, particularly through the MAPK8 and MAPK14 pathways. These complex interactions ultimately lead to a reduction in the phenotype of liver cancer cells.