Interleukin-6 induced basic fibroblast growth factor-dependent angiogenesis in basal cell carcinoma cell line via JAK/STAT3 and PI3-kinase/Akt pathways.
We have previously demonstrated a xenograft of interleukin-6 (IL-6) overexpressing basal cell carcinoma (BCC) cell line induced tumors with high vasculature in nude mice. Here we asked whether IL-6 could induce angiogenic activity in BCC cell line. Tenfold concentrated conditioned medium (CM) from IL-6 overexpressing BCC cells exhibited higher angiogenic activities in chorioallantoic membrane and Matrigel plug assays, when compared with CM from vector control or parental BCC cells. The level of basic fibroblast growth factor 2 (bFGF) mRNA and secreted bFGF increased in IL-6 overexpressing BCC cells as shown by RT-PCR and ELISA, respectively. Concordantly, recombinant IL-6 treatment caused the elevation of bFGF mRNA and protein levels in parental BCC cells in a time-dependent manner. Neutralizing bFGF function by anti-bFGF antibody significantly inhibited CM-induced human umbilical vein endothelial cells (HUVEC) tube formation and Matrigel plug formation. Meanwhile, cyclooxygenase 2 (COX-2)-specific siRNA markedly abolish HUVEC tube formation. These data indicated both bFGF and COX-2 play an essential role for IL-6-induced angiogenesis in BCC cell line. Treatment with AG490 (Janus tyrosine kinase [JAK] inhibitor) and LY294002 (PI3-Kinase inhibitor) inhibited IL-6-mediated upregulation of bFGF mRNA and protein secretion. Consistently, transfection with dominant negative mutants of signal transducer and activator of transcription 3 (STAT3) and acutely transforming retrovirus AKT8 in rodent T cell lymphoma (Akt) effectively abolished IL-6-mediated expression of bFGF mRNA and protein. Our data suggest that under in vitro experimental condition, bFGF and COX-2 are downstream effectors of IL-6-induced angiogenic activity in BCC cell. The IL-6-mediated bFGF upregulation is through activation of JAK/STAT3 and PI3-Kinase/Akt pathways.
Jee
Shiou-Hwa
SH
Department of Dermatology, National Taiwan University Hospital, Taipei, Taiwan.
Chu
Chia-Yu
CY
Chiu
Hien-Ching
HC
Huang
Yi-Ling
YL
Tsai
Wei-Ling
WL
Liao
Yi-Hua
YH
Kuo
Min-Liang
ML
D000906:Antibodies / Q000494:pharmacology; D002280:Basal Cell Carcinoma / Q000503:physiopathology*; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2; D004268:DNA-Binding Proteins / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000235:genetics* / Q000276:immunology; D015870:Gene Expression; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008565:Membrane Proteins; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; D015398:Signal Transduction / Q000502:physiology; D012878:Skin Neoplasms / Q000503:physiopathology*; D015534:Trans-Activators / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation
D000906:Antibodies; D051546:Cyclooxygenase 2; D004268:DNA-Binding Proteins; D016222:Fibroblast Growth Factor 2; D015850:Interleukin-6; D007527:Isoenzymes; D048031:JNK Mitogen-Activated Protein Kinases; D008565:Membrane Proteins; D019869:Phosphatidylinositol 3-Kinases; D011451:Prostaglandin-Endoperoxide Synthases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; D015534:Trans-Activators; C494086:STAT3 protein, human; C496540:PTGS2 protein, human; C494918:AKT1 protein, human