Prefoldin proteins 2/6, and HMG20B are regulated by HDAC1, HDAC3 and are novel therapeutic and prognostic biomarkers in hepatocellular carcinoma

Epigenetic mechanisms, such as histone deacetylases (HDACs), play an important role in the commencement and development of hepatocellular carcinoma (HCC). Previously, we have identified proteins with binds with HDAC1 and HDAC3 in liver cancer cells and also have shown that depletion of either HDAC1 or HDAC3 suppressed the expression of HDAC1/3 interacting proteins, including the prefoldin protein 2/6 (PFDN2/6), CR4-NOT transcription complex subunit 1 (CNOT1), and high mobility group 20B (HMG20b). In this study, online databases were utilized to analyze the expression of HDAC1/3, PFDN2/6, CNOT1, and HMG20b in a large panel of liver cancer cell lines, cancer tissues, and human normal and tumor liver tissues. These databases are “RNA Expression Atlas (https://www.ebi.ac.uk/gxa/home), Cancer Genome Atlas (TCGA), gene expression profiling interactive analysis (GEPIA), integrative molecular databases of hepatocellular carcinoma (HCCDB), human protein atlas, and Kaplan-Meier Plotter for RNA sequences in liver cancer (http://kmplot.com/analysis/index.php?p=service&cancer=liver_rnaseq#). The expression of these genes was verified experimentally in human HepG2 cells via semi-quantitative RT PCR. The results showed that all these genes are expressed in twenty-three human liver cancer cell lines, higher expression in human liver cancer than normal tissues. However, HDAC1 and PFDN2 are expressed at higher levels than other genes analyzed in this study. The analysis of these six genes in 364 human liver cancer patients by Kaplan Meier plotter predicted HDAC1 and PFDN2 as poor, while HMG20b as a favorable prognostic biomarker in hepatocellular carcinoma. PFDN2 and HMG20b are novel prognostic markers of hepatocellular carcinoma, identified first in this study. Further clinical studies are needed to verify the expression and patient survival concerning the expresion of PFDN2 and HMG20b in human hepatocellular carcinoma patients.