Myoferlin silencing inhibits VEGFR2-mediated proliferation of metastatic clear cell renal cell carcinoma

Abstract

Recently, ramucirumab, a drug that targets vascular endothelial growth factor receptor (VEGFR), was clinically approved; therefore, we evaluated VEGFR2 expression and its predictive roles in tumor progression in clear cell renal cell carcinoma (CCRCC). Since we do not have many options for treating aggressive renal cell carcinoma patients, the application of anti-VEGFR2 therapy might be useful. Myoferlin (MYOF) is a 230 kDa transmembrane multi-C2-domain protein that contributes to plasma membrane repair, fusion, and endocytosis and is overexpressed in several invasive cancer cell lines, including breast, pancreas, and malignant melanoma. It forms a complex with VEGFR2 to inhibit VEGFR2 degradation. In this study, a total of 152 patients who had undergone nephrectomy for CCRCC were enrolled. Based on tissue microarray (TMA) blocks, the positive intensity and high proportion of MYOF showed a statistically significant correlation with the negative intensity (p < 0.001) and low proportion (p < 0.001) of VEGFR2, respectively. In addition, Fuhrman’s nuclear grade ≥3 showed a significant correlation with VEGFR2 expression. In multivariate analysis, CCRCC patients with positive MYOF and negative VEGFR2 expression demonstrated poor clinical outcomes. We confirmed that positive MYOF expression and negative VEGFR2 expression were positively correlated in this CCRCC population. Knocking down MYOF in Caki-1 cells resulted in the downregulation of VEGFR2 at both mRNA and protein levels. Wound healing assays revealed that the loss of MYOF in Caki-1 cells decreased cell confluence compared to that in control cells. We demonstrated that MYOF influences cellular proliferation of the metastatic CCRCC cell line by regulating VEGFR2 degradation. Combined therapies targeting the MYOF and VEGFR2 pathways might be effective against metastatic CCRCC to increase patient survival.

Knockdown of Myoferlin Suppresses Migration and Invasion in Clear-Cell Renal-Cell Carcinoma

“…Another study examined the expression of VEGFR as well as MYOF in ccRCC; although an inverse correlation of MYOF and VEGFR in ccRCC tissues was observed, knockdown of MYOF led to down-regulation of VEGFR in metastatic ccRCC cell lines. The loss of MYOF additionally reduced cell confluence, leading the authors to conclude that MYOF affects cell proliferation by regulating VEGFR degradation (20). MYOF also participates in angiogenesis through its interaction with other proteins.…”

“…As a recent study suggested a decrease in VEGF-mediated cellular proliferation following MYOF silencing in metastatic ccRCC (20), we additionally investigated the influence of MYOF knockdown on the angiogenesis-associated genes TIE2, ANG2 and CAV1: Knockdown of MYOF led to an up- Two isoforms of MYOF were detected. Protein levels were found to be higher in tumor tissues.…”

mRNA Profile in Milk Extracellular Vesicles from Bovine Leukemia Virus-Infected Cattle

“…BOLA-DQB encoded a major histocompatibility complex, whose expression was altered in malignant cancers in humans; NYNRIN was shown to be a predisposing gene for Wilms tumor that causes common renal cancer in children [30,31]. Overexpression of MYOF has been associated with many cancers in humans, including breast cancer, lung cancer, and pancreatic cancer, and is shown to promote tumorigenesis, tumor cell motility, proliferation, migration, and metastasis [32][33][34]. Furthermore, other studies had reported up-regulation or down-regulation of TMEM156, ELOVL5, KIF23, AMPD3, CCNB1, CENPE, UBE2C, NXPE3, and PDE4DIP to be associated with numerous types of cancers in humans, such as breast cancer, ovarian cancer, non-small cell lung cancer, clear cell renal cell carcinoma, stomach cancer, colorectal cancer, esophageal cancer, pancreatic cancer, hepatocellular cancer, lung cancer, and prostate cancer [35][36][37][38][39][40][41][42][43][44][45].…”

Otoferlin is a prognostic biomarker in patients with clear cell renal cell carcinoma: A systematic expression analysis

“…For instance, overexpression of myoferlin on mRNA and protein level with influence on carcinogenesis has been found in ccRCC, breast cancer, lung cancer and pancreatic adenocarcinoma. [4][5][6][7][8] The expression level of the long non-coding RNA, Fer1L4, has been reported to be either increased or decreased depending on the tumor entity due to oncogenic or suppressive properties. In ccRCC, overexpression of Fer1L4 is associated with shortened survival, whereas lower expression levels were found in gastric and colon cancer leading to poor prognosis.…”

“…In recent years, altered expression patterns of some ferlin family members have thus been found in several tumor entities. For instance, overexpression of myoferlin on mRNA and protein level with influence on carcinogenesis has been found in ccRCC, breast cancer, lung cancer and pancreatic adenocarcinoma 4–8 . The expression level of the long non‐coding RNA, Fer1L4 , has been reported to be either increased or decreased depending on the tumor entity due to oncogenic or suppressive properties.…”