O‐GlcNAc‐induced nuclear translocation of hnRNP‐K is associated with progression and metastasis of cholangiocarcinoma

Abstract

O‐GlcNAcylation is a key post‐translational modification that modifies the functions of proteins. Associations between O‐GlcNAcylation, shorter survival of cholangiocarcinoma (CCA) patients, and increased migration/invasion of CCA cell lines have been reported. However, the specific O‐GlcNAcylated proteins (OGPs) that participate in promotion of CCA progression are poorly understood. OGPs were isolated from human CCA cell lines, KKU‐213 and KKU‐214, using a click chemistry‐based enzymatic labeling system, identified using LC‐MS/MS, and searched against an OGP database. From the proteomic analysis, a total of 21 OGPs related to cancer progression were identified, of which 12 have not been previously reported. Among these, hnRNP‐K, a multifaceted RNA‐ and DNA‐binding protein known as a pre‐mRNA‐binding protein, was one of the most abundantly expressed, suggesting its involvement in CCA progression. O‐GlcNAcylation of hnRNP‐K was further verified by anti‐OGP/anti‐hnRNP‐K immunoprecipitations and sWGA pull‐down assays. The perpetuation of CCA by hnRNP‐K was evaluated using siRNA, which revealed modulation of cyclin D1, XIAP, EMT markers, and MMP2 and MMP7 expression. In native CCA cells, hnRNP‐K was primarily localized in the nucleus; however, when O‐GlcNAcylation was suppressed, hnRNP‐K was retained in the cytoplasm. These data signify an association between nuclear accumulation of hnRNP‐K and the migratory capabilities of CCA cells. In human CCA tissues, expression of nuclear hnRNP‐K was positively correlated with high O‐GlcNAcylation levels, metastatic stage, and shorter survival of CCA patients. This study demonstrates the significance of O‐GlcNAcylation on the nuclear translocation of hnRNP‐K and its impact on the progression of CCA.

The Role of RNA Splicing Factors in Cancer: Regulation of Viral and Human Gene Expression in Human Papillomavirus-Related Cervical Cancer

“…hyper-O-GlcNAcylation of hnRNP-K in cholangiocarcinoma cells induces its translocation to the nucleus, where it drives the expression of genes involved in the extracellular matrix composition, cell movement, angiogenesis and epithelial mesenchymal transition, such as CCK, MMP3, PTGS2, and CTGF as well as CCND1 and XIAP (Gao R. et al, 2013;Phoomak et al, 2019). The overexpression of the SUMO1 was shown to cause the sumoylation of hnRNP K and increased c-Myc transcription associated with cell proliferation in Burkitt lymphoma (Suk et al, 2015).…”

HnRNPR-CCNB1/CENPF axis contributes to gastric cancer proliferation and metastasis

“…The heterogeneous nuclear ribonucleoproteins (hnRNPs), an RNA-binding protein, can bind to initial transcripts and are involved in all aspects of (pre)mRNA processing including gene transcription, alternative splicing, RNA stabilization, subcellular transport, and degradation control [9–12]. Further, some hnRNPs have been found to play a role in splicing, gene expression and metabolism across multiple cancer types, such as hnRNPK in cholangiocarcinoma [11], hnRNPI in colorectal cancer [13], hnRNPA1 and hnRNPAB in hepatocellular carcinoma [14, 15]. HnRNPR was originally identified as a component of the hnRNP family.…”

Quantitative proteomic analysis of the association between decreasing O‑GlcNAcylation and metastasis in MCF‑7 breast cancer cells

“…Histone H3 is reported to be modified by O-GlcNAc, which regulates various biological processes in cells (27); moreover, decreasing expression of histone H3 by stable knockdown resulted in decreased neoplastic cell transformation (28). NPM1 is also an O-GlcNAcylated protein and its modification is associated with the progression of cholangiocarcinoma (29). Reducing NPM1 expression using siRNA resulted in a significant decrease in cell proliferation and induced cell cycle arrest in leukemia, colon and breast cancer (30)(31)(32).…”