PMID- 34050696 OWN - NLM STAT- MEDLINE DCOM- 20210914 LR - 20231213 IS - 1349-7006 (Electronic) IS - 1347-9032 (Print) IS - 1347-9032 (Linking) VI - 112 IP - 9 DP - 2021 Sep TI - Connexin32 activates necroptosis through Src-mediated inhibition of caspase 8 in hepatocellular carcinoma. PG - 3507-3519 LID - 10.1111/cas.14994 [doi] AB - Necroptosis is an alternative form of programmed cell death that generally occurs under apoptosis-deficient conditions. Our previous work showed that connexin32 (Cx32) promotes the malignant progress of hepatocellular carcinoma (HCC) by enhancing the ability of resisting apoptosis in vivo and in vitro. Whether triggering necroptosis is a promising strategy to eliminate the apoptosis-resistant HCC cells with high Cx32 expression remains unknown. In this study, we found that Cx32 expression was positively correlated with the expression of necroptosis protein biomarkers in human HCC specimens, cell lines, and a xenograft model. Treatment with shikonin, a well-used necroptosis inducer, markedly caused necroptosis in HCC cells. Interestingly, overexpressed Cx32 exacerbated shikonin-induced necroptosis, but downregulation of Cx32 alleviated necroptosis in vitro and in vivo. Mechanistically, Cx32 was found to bind to Src and promote Src-mediated caspase 8 phosphorylation and inactivation, which ultimately reduced the activated caspase 8-mediated proteolysis of receptor-interacting serine-threonine protein kinase 1/3, the key molecule for necroptosis activation. In conclusion, we showed that Cx32 contributed to the activation of necroptosis in HCC cells through binding to Src and then mediating the inactivation of caspase 8. The present study suggested that necroptosis inducers could be more favorable than apoptosis inducers to eliminate HCC cells with high expression of Cx32. CI - (c) 2021 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association. FAU - Xiang, Yu-Ke AU - Xiang YK AUID- ORCID: 0000-0002-2736-6972 AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. AD - Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences & The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, China. FAU - Peng, Fu-Hua AU - Peng FH AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. FAU - Guo, Yun-Quan AU - Guo YQ AD - State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China. FAU - Ge, Hui AU - Ge H AD - State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China. FAU - Cai, Shao-Yi AU - Cai SY AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. FAU - Fan, Li-Xia AU - Fan LX AUID- ORCID: 0000-0003-1958-0140 AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. FAU - Peng, Yue-Xia AU - Peng YX AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. FAU - Wen, Hao AU - Wen H AD - State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China. FAU - Wang, Qin AU - Wang Q AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. FAU - Tao, Liang AU - Tao L AUID- ORCID: 0000-0002-9740-3724 AD - Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China. AD - State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China. LA - eng GR - 81473234/National Natural Science Foundation of China/ GR - U1303221/Joint Fund of the National Natural Science Foundation of China/ GR - 16ykjc01/Fundamental Research Funds for the Central Universities/ GR - 20160908/Department of Science and Technology of Guangdong Province/ GR - 06-410-2107209/High-level University Construction Fund of Guangdong Province/ PT - Journal Article DEP - 20210716 PL - England TA - Cancer Sci JT - Cancer science JID - 101168776 RN - 0 (Connexins) RN - 0 (Naphthoquinones) RN - 3IK6592UBW (shikonin) RN - EC 2.3.1.48 (NCOA1 protein, human) RN - EC 2.3.1.48 (Nuclear Receptor Coactivator 1) RN - EC 3.4.22.- (CASP8 protein, human) RN - EC 3.4.22.- (Caspase 8) SB - IM MH - Animals MH - Apoptosis/drug effects/genetics MH - Carcinoma, Hepatocellular/genetics/*metabolism/pathology MH - Caspase 8/*metabolism MH - Cell Line, Tumor MH - Cell Proliferation/drug effects/genetics MH - Connexins/genetics/*metabolism MH - Gene Knockdown Techniques MH - Humans MH - Liver Neoplasms/genetics/*metabolism/pathology MH - Male MH - Mice MH - Mice, Inbred BALB C MH - Mice, Nude MH - Naphthoquinones/administration & dosage MH - Necroptosis/drug effects/*genetics MH - Nuclear Receptor Coactivator 1/genetics/*metabolism MH - Phosphorylation/drug effects/genetics MH - Signal Transduction/drug effects/*genetics MH - Transfection MH - Tumor Burden/drug effects/genetics MH - Gap Junction beta-1 Protein PMC - PMC8409421 OTO - NOTNLM OT - Src OT - caspase 8 OT - connexin32 OT - hepatocellular carcinoma OT - necroptosis COIS- The authors declare that they have no competing interests. EDAT- 2021/05/30 06:00 MHDA- 2021/09/15 06:00 PMCR- 2021/09/01 CRDT- 2021/05/29 08:36 PHST- 2021/05/19 00:00 [revised] PHST- 2021/02/07 00:00 [received] PHST- 2021/05/25 00:00 [accepted] PHST- 2021/05/30 06:00 [pubmed] PHST- 2021/09/15 06:00 [medline] PHST- 2021/05/29 08:36 [entrez] PHST- 2021/09/01 00:00 [pmc-release] AID - CAS14994 [pii] AID - 10.1111/cas.14994 [doi] PST - ppublish SO - Cancer Sci. 2021 Sep;112(9):3507-3519. doi: 10.1111/cas.14994. Epub 2021 Jul 16.