Senescent peritoneal mesothelium induces a pro-angiogenic phenotype in ovarian cancer cells in vitro and in a mouse xenograft model in vivo

Abstract

It is believed that senescent cells contribute to the progression of primary and metastatic tumors, however, the exact mechanisms of this activity remain elusive. In this report we show that senescent human peritoneal mesothelial cells (HPMCs) alter the secretory profile of ovarian cancer cells (A2780, OVCAR-3, SKOV-3) by increasing the release of four angiogenic agents: CXCL1, CXCL8, HGF, and VEGF. Proliferation and migration of endothelial cells subjected to conditioned medium generated by: cancer cells modified by senescent HPMCs; cancer cells co-cultured with senescent HPMCs; and by early-passage HPMCs from aged donors, were markedly intensified. The same was the case for the vascularization, size and number of tumors that developed in the mouse peritoneum upon injection of ovarian cancer cells with senescent HPMCs. When the identified pro-angiogenic proteins were neutralized in conditioned medium from the cancer cells, both aspects of endothelial cell behavior intensified in vitro in response to senescent HPMCs were markedly reduced. The search for mediators of senescent HPMC activity using specific neutralizing antibodies and recombinant exogenous proteins showed that the intensified angiogenic potential of cancer cells was elicited by IL-6 and TGF-β1. At the transcriptional level, increased proliferation and migration of endothelial cells exposed to cancer cells modified by senescent HPMCs was regulated by HIF-1α, NF-κB/p50 and AP-1/c-Jun. Collectively, our findings indicate that senescent HPMCs may promote the progression of ovarian cancer cells by reprogramming their secretory phenotype towards increased production of pro-angiogenic agents and subsequent increase in the angiogenic capabilities of the vascular endothelium.

Senescent peritoneal mesothelium creates a niche for ovarian cancer metastases

“…Global gene expression was analyzed using quantitative real-time PCR, as described by Mikula-Pietrasik et al 27 In order to analyze cell secretome, CM were collected from young and senescent HPMCs, as described by Mikula-Pietrasik et al 12 Proteins were quantified using appropriate DuoSet Immunoassay Development kits (R&D Systems). The concentration of fibronectin was estimated using the Fibronectin Human ELISA Kit, purchased from Abcam.…”

“…9, 10 Interestingly, pro-cancerogenic activity of HPMCs increases when the cells become senescent. 11, 12 …”

Changes in the coelomic microclimate during carbon dioxide laparoscopy: morphological and functional implications

“…This is mediated by ligand-receptor pairs, including α5β1 integrins-fibronectin, αVβ3 integrinsvitronectin (VN), and CD44-hyaluronic acid [73,74,84,85]. Laparoscopic port site metastases after CO 2 -pneumoperitoneum at 4-6 mmHg in BALB/c mice inoculated with human gastric carcinoma cells were diminished by addition of hyaluronic acid, anti-integrin antibodies and anti-CD44 antibody [86].…”

“…E-cadherin transcriptional repressors include the zinc finger proteins Snail and Slug, ZEB1 (Zinc Finger E-box 1) and TWIST1, SIP1, FOXC1, FOXC2. Other cytokines and growth factors involved in MMT/EMT include hepatocyte growth factor, platelet derived growth factor (PDGF) and IL-1β [9,14,[61][62][63][84][85][86][87][88][89][90][91][92]. The majority of cytokines and chemokines released into the coelom during inflammation are secreted by peritoneal macrophages, with contributions from mesothelial cells, PMNC, fibroblasts or cancer cells when present [11,19].…”

“…The contribution of high vs. low pressure pneumoperitoneum in modifying perioperative complications, adhesion formation, postoperative pain, anastomotic healing, tumour metastasis, and venous thromboembolism in human subjects remains to be established [40-43, 67, 94]. To enhance the protective effects of humidified pneumoperitoneum in the prevention of transcoelomic metastasis, additional interventions must be capable of protecting peritoneal mesothelial cells and the peritoneal glycocalyx, decreasing free radical, cytokine and growth factor production, inhibiting adhesion, attachment and activation of cancer cells, preventing peritoneal mesothelial cell senescence/MMT and macrophage immunotolerance [5,18,72,80,85,88,90,91].…”