MDM2 binding protein as a predictor of metastasis and a novel prognostic biomarker in patients with gastric cancer

Feature Engineering-Assisted Drug Repurposing on Disease-Drug Transcriptome Profiles in Gastric Cancer

Gastric cancer is one of the most common and deadly types of cancer in the world. To develop new biomarkers and drugs to diagnose and treat this cancer, it is necessary to identify the differences between the transcriptome profiles of gastric cancer and healthy individuals, identify critical genes associated with these differences, and make potential drug predictions based on these genes. In this study, using two gene expression datasets related to gastric cancer (GSE19826 and GSE79973), 200 genes that were ready for machine learning were selected, and their expression levels were analyzed. The best 100 genes for the model were chosen with the permutation feature importance method, and central genes, such as SCARB1, ETV3, SPATA17, FAM167A-AS1, and MTBP, which were shown to be associated with gastric cancer, were identified. Then, using the drug repurposing method with the Connectivity Map CLUE Query tools, potential drugs such as Forskolin, Gestrinone, Cediranib, Apicidine, and Everolimus, which showed a highly negative correlation with the expression levels of the selected genes, were identified. This study provides a method to develop new approaches to diagnosing and treating gastric cancer by comparing the transcriptome profiles of patients gastric cancer and performing a feature engineering-assisted drug repurposing analysis based on cancer data.

MTBP enhances the activation of transcription factor ETS-1 and promotes the proliferation of hepatocellular carcinoma cells

Increasing evidence indicates that the oncoprotein murine double minute (MDM2) binding protein (MTBP) can be considered a pro-oncogene of human malignancies; however, its function and mechanisms in hepatocellular carcinoma (HCC) are still not clear. In the present work, our results demonstrate that MTBP could function as a co-activator of transcription factor E26 transformation-specific sequence (ETS-1), which plays an important role in HCC cell proliferation and/or metastasis and promotes proliferation of HCC cells. Using luciferase and real-time polymerase chain reaction (qPCR) assays, MTBP was found to enhance the transcription factor activation of ETS-1. The results from chromatin co-immunoprecipitation showed that MTBP enhanced the recruitment of ETS-1 to its downstream gene’s (mmp1’s) promoter region with ETS-1 binding sites. In cellular and nude mice models, overexpression of MTBP was shown to promote the proliferation of MHCC97-L cells with low endogenous MTBP levels, whereas the knockdown of MTBP led to inhibition of the proliferation of MHCC97-H cells that possessed high endogenous levels of MTBP. The effect of MTBP on ETS-1 was confirmed in the clinical specimens; the expression of MTBP was positively correlated with the downstream genes of ETS-1, mmp3, mmp9, and uPA. Therefore, by establishing the role of MTBP as a novel co-activator of ETS-1, this work expands our knowledge of MTBP or ETS-1 and helps to provide new ideas concerning HCC-related research.

MTBP and MYC: A Dynamic Duo in Proliferation, Cancer, and Aging

The oncogenic transcription factor c-MYC (MYC) is highly conserved across species and is frequently overexpressed or dysregulated in human cancers. MYC regulates a wide range of critical cellular and oncogenic activities including proliferation, metabolism, metastasis, apoptosis, and differentiation by transcriptionally activating or repressing the expression of a large number of genes. This activity of MYC is not carried out in isolation, instead relying on its association with a myriad of protein cofactors. We determined that MDM Two Binding Protein (MTBP) indirectly binds MYC and is a novel MYC transcriptional cofactor. MTBP promotes MYC-mediated transcriptional activity, proliferation, and cellular transformation by binding in a protein complex with MYC at MYC-bound promoters. This discovery provided critical context for data linking MTBP to aging as well as a rapidly expanding body of evidence demonstrating MTBP is overexpressed in many human malignancies, is often linked to poor patient outcomes, and is necessary for cancer cell survival. As such, MTBP represents a novel and potentially broad reaching oncologic drug target, particularly when MYC is dysregulated. Here we have reviewed the discovery of MTBP and the initial controversy with its function as well as its associations with proliferation, MYC, DNA replication, aging, and human cancer.

OSgc: A Web Portal to Assess the Performance of Prognostic Biomarkers in Gastric Cancer

Evaluating the prognostic value of genes of interest in different populations of gastric cancer (GC) is difficult and time-consuming for basic and translational researchers even though many datasets are available in public dataset depositories. In the current study, we developed a robust web-based portal called OSgc (Online consensus Survival analysis of gastric cancer) that enables easy and swift verification of known and novel biomarker candidates in GC. OSgc is composed of gene expression profiling data and clinical follow-up information of 1,824 clinical GC cases, which are collected from 7 public independent datasets derived from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). By OSgc, users input the official gene symbol and will promptly retrieve the Kaplan-Meier survival plot with hazard ratio (HR) and log rank p value on the output webpage, by which users could assess the prognostic value of interesting genes for GC patients. Five survival end points containing overall survival, progression-free survival, progression-free interval, relapse-free survival, and disease-free survival could be measured in OSgc. OSgc can greatly help cancer biologists and clinicians to explore the effect of gene expression on patient survival. OSgc is freely available without restrictions at http://bioinfo.henu.edu.cn/GC/GCList.jsp.

MTBP promoted the proliferation, migration and invasion of colon cancer cells by activating the expression of ZEB2

Colon cancer is a malignant tumor that seriously affects human health. Recently, studies revealed that the expression of MTBP enhanced the proliferation and metastasis of many types of cancer cells. And the data also showed that MTBP has the potential to regulate the expression of ZEB2. However, it is unclear whether MTBP can affect the proliferation, migration and invasion of colon cancer cells by modulating the expression of ZEB2. In this study, we established the MTBP overexpression and knockdown colon cancer cells with the transfection. Next, CCK-8 and transwell assays were carried out to determine the changes of the proliferation and invasion of colon cancer cells, respectively. After that, we overexpressed the ZEB2 in these MTBP knockdown colon cancer cells. Finally, the invasion and migration of these cells were detected with the same methods. We revealed that overexpression of MTBP enhanced the proliferation and invasion of colon cancer cells. Moreover, suppression of MTBP repressed the proliferation, migration and invasion of colon cancer cells. Furthermore, MTBP promoted the expression of ZEB2. The overexpression of ZEB2 abolished the MTBP knockdown induced inhibition of the migration and invasion of colon cancer cells. These results implied that MTBP enhanced the proliferation, migration and invasion of colon cancer cells by activating the expression of ZEB2.

[MTBP regulates migration and invasion of prostate cancer cells in vitro]

OBJECTIVE

To investigate the role of MTBP in regulating the migration and invasion of human prostate cancer cells.

METHODS

The baseline expressions of MTBP in 3 different human prostate cancer cells lines (22RV1, DU145 and Lncap) were detected using Western blotting. The cells were transfected with a small interfering RNA (siRNA) for MTBP knockdown or MTBP plasmid for MTBP overexpression, and 48 h later, the cells were examined for MTBP expression with Western blotting; the changes in the migration abilities of the cells were evaluated using wound healing assay and Transwell assay, and the cell invasiveness was assessed using Matrigel Transwell assay. The expression of E-cadherin protein, a marker of epithelial mesenchymal transition (EMT), was detected using Western blotting.

RESULTS

MTBP expression was the highest in DU145 cells followed by Lncap cells, and was the lowest in 22RV1 cells, indicating a positive correlation of MTBP expression with the level of malignancy of human prostate cancer cells. Transfection of the cells with siRNA or MTBP plasmids efficiently lowered or enhanced the expressions of MTBP in human prostate cancer cells. Wound healing assay showed that inhibition of MTBP expression decreased the migration ability of the prostate cancer cells, and MTBP overexpression significantly promoted the migration of the cells (P < 0.01). Transwell assay showed that MTBP knockdown significantly lowered the migration and invasion ability of the cells, while MTBP overexpression markedly increased the number of migrating and invading cells (P < 0.01); Western blotting results showed that MTBP knockdown increased the expression of E-cadherin protein, and MTBP overexpression decreased E-cadherin expression in the prostate cancer cells.

CONCLUSIONS

MTBP overexpression promotes the migration and invasion of human prostate cancer cells possibly relation to the induction of EMT.