IL-6/STAT3 axis initiated CAFs via up-regulating TIMP-1 which was attenuated by acetylation of STAT3 induced by PCAF in HCC microenvironment.
Aberrant tumor microenvironment is involved closely in tumor initiation and progression, in which cancer associated fibroblasts (CAFs) play a pivotal role. Both IL-6/STAT3 signaling and TIMP-1 have been found to modulate the crosstalk between tumor cells and CAFs in tumor microenvironment, however, the underlying mechanism remains unclear. Here, we showed that IL-6/STAT3 signaling was activated aberrantly in HCC tissues and correlated with poor post-surgical outcome. The in vitro experiments confirmed that activation of IL-6/STAT3 pathway enhanced TIMP-1 expression directly via phosphorylated STATs (p-STAT3)-binding with TIMP-1 promoter in Huh7 cells. Furthermore, activation of IL-6/STAT3 pathway in HCC cells was shown to induce the transformation from normal liver fibroblasts (LFs) to CAFs via up-regulating TIMP-1 expression. Co-culture with CAFs promoted the growth of Huh7 cells both in vitro and in vivo. Finally, by co-Immunoprecipitation and immunoblotting assessments, PCAF, a well-known acetyltransferase, was revealed to acetylate cytoplasmic STAT3 protein directly and regulate TIMP-1 expression negatively in Huh7 cells. In summary, this investigation indicated that there was a positive IL-6/TIMP-1 feedback loop controlling the crosstalk between HCC cells and its neighbouring fibroblasts. The data here also identified that PCAF repressed TIMP-1 expression via acetylation of STAT3. In conclusion, this investigation demonstrated that CAFs promoted HCC growth via IL-6/STAT3/AKT pathway and TIMP-1 over-expression driven by IL-6/STAT3 pathway in HCC cells brought in more CAFs through activating LFs. Finally, PCAF could block this positive feedback by acetylating STAT3 in HCC cells.
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China. Electronic address: xin.zheng.xjtu@gmail.com.
Xin
X
Zheng
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China. Electronic address: 987556919@foxmail.com.
Meng
M
Xu
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China. Electronic address: ybwsplendid@126.com.
Bowen
B
Yao
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China. Electronic address: wangcongwa@126.com.
Cong
C
Wang
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China. Electronic address: 137261184@foxmail.com.
Yuli
Y
Jia
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China. Electronic address: raymondzhengxin@foxmail.com.
Qingguang
Q
Liu
D000107:Acetylation; D000818:Animals; D000072645:Cancer-Associated Fibroblasts / Q000378:metabolism / Q000473:pathology*; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D045744:Cell Line, Tumor; D003710:Demography; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008297:Male; D008819:Mice, Nude; D008875:Middle Aged; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics* / Q000378:metabolism; D059016:Tumor Microenvironment; D015854:Up-Regulation / Q000235:genetics; D023041:Xenograft Model Antitumor Assays; D050880:p300-CBP Transcription Factors / Q000378:metabolism*; D000099224:p300-CBP-Associated Factor
D015850:Interleukin-6; D051057:Proto-Oncogene Proteins c-akt; D050796:STAT3 Transcription Factor; D019715:Tissue Inhibitor of Metalloproteinase-1; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
CAFs; HCC; IL-6/STAT3/AKT; TIMP-1