RNF187 is Downregulated Following NF-κB Inhibition in Late Erythroblasts

RING finger protein 187 as a novel potential biomarker for predicting the prognosis of ovarian carcinoma in 2 cancer centers

RING finger protein 187 (RNF187) has been used to predict prognosis of several human carcinomas. However, the clinicopathologic and prognostic implication of RNF187 expression in ovarian carcinomas remains not to be evaluated. The aim of this study was to explore the clinicopathologic and the prognostic significance of RNF187 in patients with ovarian carcinomas. Expression levels of RNF187 protein were investigated by immunohistochemical staining based on tissue-microarray composed of 147 patients with ovarian carcinomas. Receiver operating characteristic curve analysis was used to select the ideal cut-off value of RNF187 expression in ovarian carcinoma, and then analyze the correlation between the status of RNF187 expression and various clinicopathologic variables by chi-square test. Univariate analysis was employed to investigate the association between clinicopathologic variables and prognosis of patients by Kaplan-Meier method. Multivariate analysis was performed to identify the independent prognostic factors by the Cox regression model. Our results demonstrated that high expression of RNF187 was significantly associated with late FIGO stage, high histologic grade and pN1 stage in ovarian carcinoma (P < 0.05). Univariate analysis uncovered patients with the high expression of RNF187 have the worse overall survival and disease-free survival (P < 0.05). More surprisingly, multivariate analysis determined that the RNF187 expression was served as an independent prognostic factor in ovarian carcinoma. The high expression of RNF187 might influence a more aggressive biological behavior in ovarian carcinoma. Therefore, RNF187 expression could be useful to act as a new independent prognostic biomarker for patients with ovarian carcinoma.

An essential role of RNF187 in Notch1 mediated metastasis of hepatocellular carcinoma

Background

Aberrant activation of Notch signaling has been causally linked to the metastasis of hepatocellular carcinoma (HCC), however the underlying molecular mechanisms are still poorly understood. RING finger protein 187 (RNF187) was recently revealed to be a driver of several cancers, but its expression pattern and biological function in HCC are unknown.

Methods

The expression levels of Notch1 and RNF187 were assessed in two independent cohorts of HCC tissues, and modulation of Notch1 in HCC cells was performed to explore the regulatory role of Notch1 in HCC metastasis. RNA-sequencing (RNA-seq), bioinformatics analysis, luciferase reporter analysis, and chromatin immunoprecipitation assay (ChIP) were used to clarify the relationship between Notch1 signaling and its potential target Ring finger protein 187 (RNF187). Gain- and loss-of-function studies were used to dissect the role of Notch1-RNF187 signaling in promoting HCC metastasis. The impact of Notch1-RNF187 activity in determining clinical prognosis for HCC patients was evaluated by multivariate Cox regression.

Results

By RNA-seq, luciferase reporter analysis, and ChIP assay, RNF187 was confirmed to be a direct transcriptional target of Notch1, as Notch1 could activate RNF187 promoter whereas the pro-migratory and pro-invasive effects of Notch1 were significantly attenuated by RNF187 knockdown. Meanwhile, RNF187 silencing could attenuate the Notch1-dependent epithelial-mesenchymal transition (EMT). Moreover, overexpression of RNF187 counteracted the inhibitory effect of Notch1 knockdown on cancer progression. Importantly, HCC patients with high level of hepatic Notch1 expression had shorter disease-free survival (DFS) than those with low level of hepatic Notch1 expression. Furthermore, patients with high level of Notch1 and RNF187 co-expression showed the shortest DFS. The expression level of Notch1 and RNF187 was an independent prognostic factor for HCC.

Conclusions

For the first time we identified that RNF187 is an essential factor for Notch1 to promote invasion and metastasis of HCC. Of highly clinical relevance, we found that activation of Notch1-RNF187 correlates with a worse prognosis of HCC patients. These findings provide a solid foundation for developing novel strategies to tackle HCC metastasis.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1382-x) contains supplementary material, which is available to authorized users.

Overexpression of RNF187 induces cell EMT and apoptosis resistance in NSCLC

Overexpression of RING finger protein 187 (RNF187) was recently revealed to be a driver of several cancers. However, the expression and function of RNF187 in non-small-cell lung cancer (NSCLC) are still unknown. Here, we uncovered that RNF187 expression was significantly higher in NSCLC samples than in matched normal lung samples at both the messenger RNA (3.55 ± 0.79 vs. 1.74 ± 0.63) and protein (2.85 ± 0.14 vs. 1.24 ± 0.02) levels. By downregulating or upregulating RNF187 expression in NSCLC cells, we showed that elevated RNF187 expression distinctly enhanced the migration, invasion, and colony formation of NSCLC cells. Moreover, we revealed that high level of RNF187 promoted NSCLC progression by inducing cell epithelial to mesenchymal transition (EMT) and apoptosis resistance mainly via activating the mitogen-activated protein kinase and PI3K signaling. Clinically, we demonstrated that RNF187 expression was positively associated with advanced TNM stage (p = 1.29 × 10 ^-6 ), lymph node metastasis ( p = 2.69 × 10 ^-9 ), and large tumor size ( p = 0.002). Importantly, NSCLC patients with elevated RNF187 expression related to the short overall survival rate( p = 1.29, E-7) and could serve as an independent prognostic factor in NSCLC patients. Thus, elevated RNF187 expression promotes NSCLC development by inducing cell EMT and apoptosis resistance, and RNF187 may be a novel prognostic indicator for NSCLC patients after curative resection.

Up-regulation of RNF187 induces hepatocellular carcinoma cell epithelial to mesenchymal transitions

Ring finger protein 187 (RNF187) has been identified to be a co-activator linking c Jun to Ras signaling. However, the expression and function of RNF187 in hepatocellular carcinomas (HCC) remains unclear. Here, we tried to determine the expression and roles of RNF187 in hepatocellular carcinomas (HCC).The expression of RNF187 was determined in HCC tissues and cell lines, and we found that RNF187 expressed highly in HCC tissues compared with the corresponding adjacent liver tissues both in mRNA and protein level, which was consistent with the result of immunohistochemistry on HCC tissue microarrays. In HCC cell lines, the level of RNF187 was positively associated with the HCC cells metastatic potential. By the RNF187 interference and cDNA transfection, we showed that the high level of RNF187 induced the HCC cells invasion and metastasis both in vitro and in vivo, as well as the high ability of colony formation.Mechanistically, we detected the high level of RNF187 promoted cell scatter by inducing epithelial-mesenchymal transition (EMT). Clinically, the high level of RNA187 was significantly correlated with a malignant phenotype, including larger tumor size, multiple tumors, and microvascular invasion. Importantly, high level of RNF187 correlated with HCC patients' shorter OS and lower disease free survival rates than those with low level of RNF187. Our results revealed that elevated expression of RNF187 induced hepatocellular carcinoma cell epithelial to mesenchymal transitions, and represented a novel marker for predicting the poor prognosis of HCC.