LCMT1 indicates poor prognosis and is essential for cell proliferation in hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is one of the most malignant type of cancers. Leuci carboxyl methyltransferase 1 (LCMT1) is a protein methyltransferase that plays an improtant regulatory role in both normal and cancer cells. The aim of this study is to evaluate the expression pattern and clinical significance of LCMT1 in HCC.

Methods: The expression pattern and clinical relevance of LCMT1 were determined using the Gene Expression Omnibus (GEO) database, the Cancer Genome Atlas (TCGA) program, and our datasets. Gain-of-function and loss-of-function studies were employed to investigate the cellular functions of LCMT1 in vitro and in vivo. Quantitative real-time polymerase chain reaction (RT-PCR) analysis, western blotting, enzymatic assay, and high-performance liquid chromatography were applied to reveal the underlying molecular functions of LCMT1.

Results: LCMT1 was upregulated in human HCC tissues, which correlated with a "poor" prognosis. The siRNA-mediated knockdown of LCMT1 inhibited glycolysis, promoted mitochondrial dysfunction, and increased intracellular pyruvate levels by upregulating the expression of alani-neglyoxylate and serine-pyruvate aminotransferase (AGXT). The overexpression of LCMT1 showed the opposite results. Silencing LCMT1 inhibited the proliferation of HCC cells in vitro and reduced the growth of tumor xenografts in mice. Mechanistically, the effect of LCMT1 on the proliferation of HCC cells was partially dependent on PP2A.

Conclusions: Our data revealed a novel role of LCMT1 in the proliferation of HCC cells. In addition, we provided novel insights into the effects of glycolysis-related pathways on the LCMT1regulated progression of HCC, suggesting LCMT1 as a novel therapeutic target for HCC therapy.