Potential Regulatory Role of Human-Carboxylesterase-1 Glycosylation in Liver Cancer Cell Growth

• DOI: 10.1021/acs.jproteome.0c00787
• Publication Date: 2020-11-18T23:24:50Z
• Authors: Keun Na; Minjoo Kim; Chae-Yeon Kim; Jong-Sun Lim; Jin-Young Cho; Heon Shin; Hyo Jin Lee; Byeong Jun Kang; Dai Hoon Han; Hoguen Kim; Ja-Hyun Baik; Magdalena Swiatek...; Johann Karl; Young-Ki Paik
• Keywords: 0301 basic medicine; 570; Carcinoma, Hepatocellular; Glycosylation; glycosylation; Liver Neoplasms; 610; hepatocellular carcinoma; carboxylesterase 1; 3. Good health; Gene Expression Regulation, Neoplastic; transcriptomics; 03 medical and health sciences; proteomics; Cell Line, Tumor; Humans; Carboxylic Ester Hydrolases; Cell Proliferation

We previously reported that human carboxylesterase 1 (CES1), a serine esterase containing unique N-linked glycosyl group at Asn79 (N79 CES1), is candidate serological marker of hepatocellular carcinoma (HCC). CES1 normally present low-to-undetectable levels in normal plasma, HCC tumors, and major liver cancer cell lines. To investigate the potential mechanism underlying suppression expression cells, we took advantage low detectability this tumors by overexpressing multiple lines, including stable Hep3B cells. found population CES1-overexpressing (OE) cells decreased their doubling time was longer compared with mock control Using interactive transcriptome, proteome, subsequent Gene Ontology enrichment analysis CES1-OE substantial decreases genes involved cycle regulation proliferation. This antiproliferative function N79 glycan further supported quantitative real-time polymerase chain reaction, flow cytometry, an apoptosis protein array assay. An key signaling target proteins via Western blotting suggested overexpression exerted effect PKD1/PKCμ pathway. Similar results were also seen another line (PLC/RFP/5) after transient transfection but not similarly treated non-HCC lines (e.g., HeLa Tera-1 cells), suggesting likely exerts cell-type-specific suppressive effect. Given glycan) known to influence enzyme activity, hypothesized post-translational modification may be linked its activity. regulatory on cellular growth, mutated single N-glycosylation site from Asn Gln (CES1-N79Q) site-directed mutagenesis. Fluorescence 2-D difference gel electrophoresis lysates revealed increase growth decrease carrying N79Q mutation. Thus our suggest glycosylation plays role. These functions underlie undetectability Mass spectrometry data are available ProteomeXchange under identifier PXD021573.