Downregulation of RIG-I mediated by ITGB3/c-SRC/STAT3 signaling confers resistance to interferon-α-induced apoptosis in tumor-repopulating cells of melanoma
Background Interferon-alpha (IFN-alpha) plays a pivotal role in host antitumor immunity, and the evasion of IFN-alpha signaling pathway can lead to IFN-alpha resistance during the treatment of cancer. Although the interplay between IFN-alpha and tumor cells has been extensively investigated in differentiated tumor cells, much less attention has been directed to tumor-repopulating cells (TRCs). Methods Three-dimentional soft fibrin matrix was used to select and grow highly malignant and tumorigenic melanoma TRCs. The regulation of integrin beta 3 (ITGB3)-c-SRC-STAT signaling pathway in melanoma TRCs was investigated both in vitro and in vivo. The relevant mRNA and protein expression levels were analyzed by qRT-PCR and western blot analysis. Immunoprecipitation and chromatin immunoprecipitation (ChIP) followed by qPCR (ChIP-qPCR) assays were performed to detect protein-protein and protein-DNA interactions. The clinical impacts of retinoic acid inducible gene-I (RIG-I) were assessed in melanoma datasets obtained from The Cancer Genome Atlas and Gene Expression Omnibus profiles. Results IFN-alpha -induced apoptosis was decreased in melanoma TRCs. Compared with conventional flask-cultured cells, IFN-alpha -mediated STAT1 activation was diminished in melanoma TRCs. Decreased expression of RIG-I in melanoma TRCs led to diminished activation of STAT1 via enhancing the interaction between Src homology region 2 domain-containing phosphatase-1 and STAT1. In addition, low expression levels of RIG-I correlated with poor prognosis in patients with melanoma. STAT3 was highly phosphorylated in TRCs and knockdown of STAT3 reversed the downregulation of RIG-I in TRCs. Knockdown of STAT3 resulted in STAT1 activation and increased expression of the pro-apoptosis genes in IFN-alpha -treated TRCs. Combined treatment of STAT3 inhibitor and IFN-alpha increased the apoptosis rate of TRCs. Disruption of ITGB3/c-SRC/STAT3 signaling pathway significantly elevated the efficiency of IFN-alpha -induced apoptosis of TRCs. Conclusions In melanoma TRCs, ITGB3-c-SRC-STAT3 pathway caused RIG-I repression and then affect STAT1 activation to cause resistance to IFN-alpha -induced apoptosis. RIG-I is a prognostic marker in patients with melanoma. Combination of STAT3 inhibitor and IFN-alpha could enhance the efficacy of melanoma treatment. Our findings may provide a new concept of combinatorial treatment for future immunotherapy.
基金:
National Basic Research Program of China (973program) [2015CB932600]; National Natural Science Foundation of China [81702767, 81801066]; Hubei Provincial Natural Science Foundation of China [2018CFC874]; Wuhan University [2042019kf0206]; Renmin Hospital, Hubei University of Medicine [03328]; Beijing Medical and Health Foundation [YWJKJJHKYJJ-B17241-Q1]
第一作者单位:[1]Hubei Univ Med, Renmin Hosp, Dept Oncol, Shiyan, Hubei, Peoples R China
通讯作者:
通讯机构:[1]Hubei Univ Med, Renmin Hosp, Dept Oncol, Shiyan, Hubei, Peoples R China[4]Wuhan Univ, Dept Gastroenterol, Zhongnan Hosp, Wuhan, Hubei, Peoples R China[5]Hubei Clin Ctr, Wuhan, Hubei, Peoples R China[6]Key Lab Intestinal & Colorectal Dis, Wuhan, Hubei, Peoples R China[8]Hubei Univ Med, Inst Canc Res, Renmin Hosp, Shiyan, Hubei, Peoples R China
推荐引用方式(GB/T 7714):
Li Yong,Song Yingqiu,Li Pindong,et al.Downregulation of RIG-I mediated by ITGB3/c-SRC/STAT3 signaling confers resistance to interferon-α-induced apoptosis in tumor-repopulating cells of melanoma[J].JOURNAL FOR IMMUNOTHERAPY OF CANCER.2020,8(1):doi:10.1136/jitc-2019-000111.
APA:
Li, Yong,Song, Yingqiu,Li, Pindong,Li, Mingxing,Wang, Haizhou...&Cao, Fengjun.(2020).Downregulation of RIG-I mediated by ITGB3/c-SRC/STAT3 signaling confers resistance to interferon-α-induced apoptosis in tumor-repopulating cells of melanoma.JOURNAL FOR IMMUNOTHERAPY OF CANCER,8,(1)
MLA:
Li, Yong,et al."Downregulation of RIG-I mediated by ITGB3/c-SRC/STAT3 signaling confers resistance to interferon-α-induced apoptosis in tumor-repopulating cells of melanoma".JOURNAL FOR IMMUNOTHERAPY OF CANCER 8..1(2020)