Abstract 201: The mechanism of vascular mimicry in clear cell renal cell cancer

Abstract

Although anti-angiogenic drugs were used as first-line treatment in metastatic clear cell renal cell cancer (ccRCC), some patients with metastatic ccRCC still had limited survival benefit from anti-angiogenic therapy. The main reason was resistance to anti-angiogenesis treatment. Tumor blood vessel could be divided into endothelial cell-derived or tumor cell-derived vessels. Tumor cell-derived vascular channel was called as tumor vascular mimicry (VM). PAS-CD34 staining in ccRCC tissues revealed that the expression status of VM was different in ccRCC patients. And the progression-free survival and overall survival were significantly shorter in ccRCC patients with high VM expression level. To explore the effect of VM on the resistance to anti-angiogenesis treatment and the molecular mechanism of VM, we successfully established a three-dimensional culture model for the formation of tumor cell-derived vessel-like structures. We found the formation of blood vessel-like structures in kidney cancer cells was not affected by the anti-angiogenic drug, such as Sunitinib, suggesting that VM was closely associated with resistance to anti-angiogenic therapy. Moreover, we had discovered the “molecular signature of vascular mimicry in renal cancer”. Using this signature, 531 ccRCC patients in TCGA could be divided into two groups with different prognosis. More importantly, we found that HGF/c-MET signaling pathway regulated the expression of Serpinb2 through the downstream AKT pathway, and thus affected the formation of vascular mimicry in SN12C, 786-O cells. In addition, we also had found that HGF could promote the formation of blood vessel-like structure in lung and bladder cancer cells, and the molecular signature of vascular mimicry in renal cancer also could differentiate patients with renal papillary carcinoma, bladder cancer, endometrial cancer, lung adenocarcinoma cancer, and pancreatic cancer. These finding suggested that the molecular mechanism of vascular mimicry in renal cancer was universal, to some extent. This project partially elucidated the molecular mechanism of vascular mimicry in renal cancer and its clinical significance, laying a theoretical foundation for the development of more effective anti-angiogenic drugs. Citation Format: Jun-Ping Yang, Xing-Si Peng, Chao-Nan Qian. The mechanism of vascular mimicry in clear cell renal cell cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 201.