MiR-205/YAP1 in Activated Fibroblasts of Breast Tumor Promotes VEGF-independent Angiogenesis through STAT3 Signaling

Abstract

Tumor microenvironment contributes to tumor angiogenesis. However, the role of the activated cancer associated-fibroblasts (CAFs) in angiogenesis is still unclear. Here we report that miR-205/YAP1 signaling in the activated stromal fibroblasts plays a critical role in VEGF-independent angiogenesis in breast tumor. Methods: miR-205 expression was assessed by quantitative real-time polymerase chain reaction (qRT-PCR); YAP1 expression by qRT-PCR, western blotting and immunohistochemistry; IL11 and IL15 expression by qRT-PCR, western blotting and ELISA. Tube formation and three-dimensioned sprouting assays in vitro, and orthotopic Xenografts in vivo were conducted as angiogenesis experiments. The mechanism of miR-205/YAP1-mediated tumor angiogenesis was analyzed via overexpression and shRNA, siRNA, or antibody neutralization experiments in combination with anti-VEGF antibody or Axitinib. Results: miR-205/YAP1 signaling axis activates breast normal fibroblasts (NFs) into CAFs, promotes tubule formation and sprouting of Human Umbilical Vein Endothelial Cells (HUVECs). Rescue of miR-205 in CAFs blunts angiogenesis processes. YAP1, a target of miR-205, does not regulate VEGF expression but specifically enhances IL11 and IL15 expressions, maintaining tumor angiogenesis even in the presence of Axitinib or after exhaustion of VEGF by neutralizing VEGF antibody. IL11 and IL15 released from CAFs activate STAT3 signaling in HUVECs. Blockage of IL11 and IL15 expression in CAFs results in the inactivation of STAT3-signaling in HUVECs and repression of the CAF-induced angiogenesis. The blunt angiogenesis halts the invasion and metastasis of breast cancer cells in vivo. Conclusions: These results provide a novel insight into breast CAF-induced tumor angiogenesis in a VEGF-independent manner.

Exosomal Sonic Hedgehog derived from cancer‐associated fibroblasts promotes proliferation and migration of esophageal squamous cell carcinoma

“…Donnarumma et al found that breast cancer cells cultured by the CAFs‐derived exosomes exhibited a significantly increased ability to form mammospheres, anchorage‐independent cell growth and higher expression of stem cell and EMT markers . It is also reported that, in breast cancer, the activated stromal fibroblasts could contribute to the VEGF‐independent angiogenesis via the miR‐205/YAP1 signaling . In HCC, Liu et al showed that CAFs promote HCC metastasis through the activation of Hedgehog and TGF‐β pathways via chemokines .…”

“…37 It is also reported that, in breast cancer, the activated stromal fibroblasts could contribute to the VEGF-independent angiogenesis via the miR-205/YAP1 signaling. 38 In HCC, Liu et al showed that CAFs promote HCC metastasis through the activation of Hedgehog and TGF-β pathways via chemokines. 9 Collectively, these results revealed that CAFs-tumor cell crosstalk facilitates the progression of tumors.…”

Allicin Inhibits Proliferation and Invasion in Vitro and in Vivo via SHP-1-Mediated STAT3 Signaling in Cholangiocarcinoma

“…Moreover, STAT3 modulates the expression of genes involved in anti-apoptosis (Bcl-2, Bcl-xL, and survivin), proliferation (cyclin D1) [11], and angiogenesis (VEGF) [12]. Recently, studies have reported that STAT3 is constitutively activated in many cancers, including breast cancer [13], ovarian cancer [14], and lung cancer [15]. Inhibition of STAT3 cascade-related protein expression has been shown to induce cell cycle arrest and apoptosis [16].…”

Role of microRNAs in remodeling the tumor microenvironment (Review)

“…miR-200s target friend leukemia virus integration 1 (Fli-1) and transcription factor 12 (TCF12) in the breast cancer microenvironment (32,33). Moreover, decreased miR-205 was shown to convert breast NFs into CAFs by promoting Yes-associated protein 1 (YAP1) expression, which has been proven to be involved in angiogenesis (34).…”

“…In breast cancer, tumor cells can release miR-939 to endothelial cells via exosomes, and miR-939 was shown to suppress the expression of its target gene vascular endothelial-cadherin in endothelial cells, increasing vascular permeability (66). Moreover, miR-205 suppression in other cells of the TME, including CAFs, was reported to enhance tubule formation and sprouting of endothelial cells by regulating YAP1-mediated IL-11 and IL-15 expression and secretion (34). In prostate cancer, miR-218 downregulation was shown to promote tumor angiogenesis through the regulatory-associated protein-independent companion of mammalian target of rapamycin complex 2/VEGFA axis (67).…”