title: Dependence of fibroblast infiltration in tumor stroma on type IV collagen-initiated integrin signal through induction of platelet-derived growth factor.
abstract: Cancer-associated fibroblasts play a crucial role in accelerating tumor progression, but there is a knowledge gap regarding the chemotactic signal activated in a tumor microenvironment. In this study, the expression of type IV collagen was knocked down using a lentiviral-mediated short hairpin RNA strategy. Although there was no obvious effect on cell growth in vitro, silencing the Col4-α1 gene decreased the tumorigenicity of B16F10 in C57BL/6 mice, which was accompanied by a reduction in the infiltration of alpha-smooth muscle actin-positive (α-SMA+) fibroblasts. Silencing the Col4-α1 gene or disrupting integrin engagement by blocking the antibody reduced the expression of platelet-derived growth factor A (PDGF-A), a potent chemotactic factor for fibroblasts. Furthermore, ectopic expression of the autoclustering integrin mutant significantly stimulated PDGF-A expression in murine B16F10 and human U118MG and Huh7 cells. PDGF-A-specific sh-RNA and neutralizing anti-PDGF-A antibody effectively inhibited the transwell migration of fibroblasts. Adding recombinant PDGF-A back to shCol cell-conditioned media restored the fibroblast-attraction ability indicating that PDGF-A is a major chemotactic factor for fibroblasts in the current study model. The integrin-associated PDGF-A production correlated with the activation of Src and ERK. High type IV collagen staining intensity colocalized with elevated PDGF-A expression was observed in tumor tissues obtained from hepatoma and glioma patients. The integrin signal pathway was activated by collagen engagement through Src and ERK, leading to enhanced PDGF-A production, which serves as a key regulator of fibroblast recruitment.
authors: Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan. Electronic address: wilson1211983@gmail.com.
authors: Sheng-Yi
authors: SY
authors: Chen
authors: Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan. Electronic address: dutyzoe@gmail.com.
authors: Jo-Shi
authors: JS
authors: Lin
authors: Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan. Electronic address: michellin323@hotmail.com.
authors: Huan-Ching
authors: HC
authors: Lin
authors: Department of Surgeon, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan. Electronic address: ysshan@mail.ncku.edu.tw.
authors: Yan-Shen
authors: YS
authors: Shan
authors: Department of Physical Therapy, China Medical University, Taichung 40402, Taiwan. Electronic address: chengyu@mail.cmu.edu.tw.
authors: Yu-Jung
authors: YJ
authors: Cheng
authors: Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan; Center for Gene Regulation and Signal Transduction Research, National Cheng Kung University, Tainan 70101, Taiwan. Electronic address: y1357@mail.ncku.edu.tw.
authors: Bei-Chang
authors: BC
authors: Yang
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000473:pathology; D045744:Cell Line, Tumor; D024141:Collagen Type IV / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology
chemical_list: C547475:COL4A1 protein, human; D024141:Collagen Type IV; D019012:Integrin beta1; D010982:Platelet-Derived Growth Factor; D047428:Protein Kinase Inhibitors; C075278:platelet-derived growth factor A
keywords: Cancer-associated fibroblast; Integrin; Platelet-derived growth factor A; Tumor growth; Type IV-α1 collagen