Nek2 augments sorafenib resistance by regulating the ubiquitination and localization of β-catenin in hepatocellular carcinoma

Abstract

Background Sorafenib is the first-line treatment for advanced-stage hepatocellular carcinoma (HCC). Several studies have shown that the up-regulation of β-catenin plays a role in sorafenib resistance in HCC; however, the mechanism associated with this phenomenon remains elusive. Methods Western blotting, flow cytometry, and an evaluation of IC 50 values were used to confirm the role of β-catenin in HCC sorafenib resistance. Immunoprecipitation and western blotting were then performed to identify regulatory interactions between β-catenin and Nek2. Further, western blotting, flow cytometry, and an in vivo xenograft model were used to evaluate the function of Nek2 in HCC sorafenib resistance, whereas rescue experiments were performed to confirm that Nek2 induces sorafenib resistance via β-catenin. Finally, western blotting and immunohistochemistry were used to evaluate the expression level of Nek2 in paired HCC and non-tumor tissues. Results We showed that β-catenin could suppress sorafenib-induced apoptosis and cell growth inhibition in HCC cell lines. By screening β-catenin-interacting proteins, we found that Nek2 could bind β-catenin in sorafenib-treated HCC cell lines. Our results also showed that Nek2 stabilizes β-catenin and promotes its translocation to the nucleus, consequently activating the transcription of downstream target genes. We further confirmed that Nek2 could induce sorafenib resistance in HCC cell lines, and that β-catenin was the key element involved in this process. Further, a xenograft tumor model showed that Nek2 knockdown could improve the anti-tumor effect of sorafenib, whereas an analysis of tumor proteins showed that Nek2 regulates β-catenin protein levels and its nuclear translocation in vivo. In addition, Nek2 was found to be up-regulated in HCC tissue, and especially in advanced-stage disease. Conclusions Our study proves that Nek2 induces HCC sorafenib resistance via β-catenin and suggests a novel therapeutic strategy to improve the anti-tumor effects of sorafenib in HCC. Electronic supplementary material The online version of this article (10.1186/s13046-019-1311-z) contains supplementary material, which is available to authorized users.

Transcription Factors in Cancer Development and Therapy

“…Breast cancer Paclitaxel or Gemcitabine [70] HIF-dependent BMX kinase upregulation resulted in therapeutic resistance through a compensatory pro-survival signaling mechanism Acute myeloid leukemia Sorafenib [197] HIF2 and COX2 activated Snail and downregulated E-cadherin expression to promote invasion and resistance to sorafenib Renal cancer Sorafenib [198] HIF-2α activated TGF-α/EGFR pathway to promote proliferation and sorafenib-resistance, which was antagonized by HIF-2α siRNA Hepatocellular carcinoma Sorafenib [199] Prospero-related homeobox 1 (PROX1) upregulated β-catenin transcription and nuclear translocation to activate the Wnt/β-catenin pathway in HCC, which lead to high proliferation and sorafenib-resistance Hepatocellular carcinoma Sorafenib [209] Nek2 stabilized β-catenin, increased its nuclear translocation, and activated the transcription of its downstream target genes, to promote sorafenib-resistance Hepatocellular carcinoma Sorafenib [210] Suppression of checkpoint kinase 1 (CHK1) pathway by Wnt/β-catenin in p53 wild-type colorectal cancer cells, promoted drug-resistance Colorectal cancer 5-Fluorouracil [211] IL-6/p-STAT3 activation increased the expression of DNMT3b/OCT4 which conferred early recurrence and poor prognosis in HCC Hepatocellular carcinoma Sorafenib [215] The expression of Sox2 and CD24 were upregulated in targeted-therapy resistant melanoma cells, which was mediated by activated STAT3. Activation of STAT3, Sox2 and CD24 promoted adaptive-resistance to BRAF inhibitors.…”

Systematic Analysis of the Transcriptome Profiles and Co-Expression Networks of Tumour Endothelial Cells Identifies Several Tumour-Associated Modules and Potential Therapeutic Targets in Hepatocellular Carcinoma

“…SMAC was not identified as hub-gene in the M1 module. NEK2 plays a role in developing drug resistance against various anti-cancer drugs, including 5-fluorouracil and sorafenib [ 69 , 96 , 97 ]. A potential role of NEK2 in resistance development against lenvatinib and other anti-angiogenic drugs has not been investigated yet.…”

NEK2 regulates cellular proliferation and cabergoline sensitivity in pituitary adenomas

“…NEK2 is associated with drug resistance in multiple cancers 13 , and several publications have shown regulation of NEK2 by antitumor drugs. Deng's research demonstrated that NEK2 binds β-catenin, blocking the interaction between NEK2 and the destruction complex; ultimately contributing to sorafenib resistance in hepatocellular carcinoma 20 . In Wen's study, overexpression of NEK2 in cancer cells resulted in enhanced chromosomal instability, cellular proliferation, and drug resistance; while NEK2 knockdown overcame cancer cell resistance to drugs and induced apoptosis in vitro and in a xenograft myeloma mouse model 21 .…”