Elevated expression of Cyr61 enhances peritoneal dissemination of gastric cancer cells through integrin alpha2beta1.
Cysteine-rich 61 (Cyr61/CCN1) is involved in human gastric cancer development and progression. Nonetheless, the role of Cyr61 as regards peritoneal dissemination of such cancers has not yet been completely characterized. We used liposome-mediated transfection to establish Cyr61, or antisense Cyr61, expression vectors into gastric cancer AGS or MKN45 cell lines. Transfectants were tested by means of a cancer-cell adhesion assay in vitro and ex vivo. Furthermore, a functional integrin fluorescence-activated cell sorting assay, reverse transcription-PCR, and an AP-1 reporter assay were performed to investigate the potential signaling pathway of Cyr61. It was shown that stable transfection of Cyr61 into the AGS cell line strongly enhanced its adhesion ability. The overexpression of Cyr61 within AGS cells significantly increased the functional expression of integrin alpha(2)beta(1). Function-neutralizing antibody to integrin alpha(2)beta(1) effectively suppressed the Cyr61-mediated enhanced adhesion of AGS cells to peritoneal tissue. Promoter assays of integrin alpha2 gene further revealed that the AP-1 pathway was evidently activated within Cyr61-expressing AGS cells. Animal studies have revealed that mice injected with Cyr61-overexpressed AGS cells featured a greater number of peritoneal seeding nodules and a lower survival rate than the Neo control cell lines, and when such cells were treated with functional blocking antibody to integrin alpha(2)beta(1), they were able to elicit a decline in the peritoneal dissemination. The data suggest that Cyr61 may contribute to the peritoneal dissemination of gastric cancer by promoting tumor-cell adhesion ability through the up-regulation of the functional integrin alpha(2)beta(1) via an AP-1-dependent pathway.
Lin
Ming-Tsan
MT
Department of Primary Care Medicine, National Taiwan University Hospital, Taipei 100, Taiwan.
Chang
Cheng-Chi
CC
Lin
Been-Ren
BR
Yang
Hsin-Yu
HY
Chu
Chia-Yu
CY
Wu
Ming-Hsun
MH
Kuo
Min-Liang
ML
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D055515:Cysteine-Rich Protein 61; D016373:DNA, Antisense / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000235:genetics; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis* / Q000235:genetics; D038982:Integrin alpha2beta1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000235:genetics; D008081:Liposomes; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D010534:Peritoneal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000556:secondary; D010537:Peritoneum / Q000378:metabolism / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
D000906:Antibodies; C501848:CCN1 protein, human; D055515:Cysteine-Rich Protein 61; D016373:DNA, Antisense; D017874:Immediate-Early Proteins; D038982:Integrin alpha2beta1; D036341:Intercellular Signaling Peptides and Proteins; D008081:Liposomes; D018808:Transcription Factor AP-1