EGFR phosphorylates FAM129B to promote Ras activation.

Ras GTPase-activating proteins (GAPs) are important regulators for Ras activation, which is instrumental in tumor development. However, the mechanism underlying this regulation remains elusive. We demonstrate here that activated EGFR phosphorylates the Y593 residue of the protein known as family with sequence similarity 129, member B (FAM129B), which is overexpressed in many types of human cancer. FAM129B phosphorylation increased the interaction between FAM129B and Ras, resulting in reduced binding of p120-RasGAP to Ras. FAM129B phosphorylation promoted Ras activation, increasing ERK1/2- and PKM2-dependent ß-catenin transactivation and leading to the enhanced glycolytic gene expression and the Warburg effect; promoting tumor cell proliferation and invasion; and supporting brain tumorigenesis. Our studies unearthed a novel and important mechanism underlying EGFR-mediated Ras activation in tumor development.

Identification of the differential expression of serum microRNA in type 2 diabetes.

The identification of disease-specific alterations in miRNA expression and the ability to detect miRNAs in serum furnish the basis for identified potential research value. This study was aimed to characterize the expression of miRNAs in the serum samples from people with type 2 diabetes mellitus (T2DM) and healthy individuals in order to detect the differential expression of miRNAs in T2DM. In total, 582 participants were recruited. Microarray-based miRNA expression profiles were screened in pooled serum samples from two groups (T2DM and healthy control). The candidates' miRNAs were validated by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Five significantly different serum miRNAs were identified in T2DM patients (hsa-miR-320d, hsa-miR-4534, hsa-miR-3960, hsa-miR-451a, and hsa-miR-572) compared to those in the serum of healthy controls. This study provided evidence that serum miRNAs had differential expressions between healthy controls and T2DM patients. These five differential expression miRNAs might be of help for subsequent study in T2DM.

MicroRNA­4530 suppresses cell proliferation and induces apoptosis by targeting RASA1 in human umbilical vein endothelial cells.

MicroRNAs (miRNAs/miRs) are a class of endogenous and non­coding RNAs that are present in eukaryotes. In previous studies, miRNAs have been revealed to have an important role in cell growth and apoptosis. In the present study, the function of a novel and rarely studied miRNA, miR­4530, was investigated in human umbilical vein endothelial cells (HUVECs). The expression level of miR­4530 in HUVECs was investigated using reverse transcription­quantitative polymerase chain reaction following transfection with miR­4530 precursor plasmids, anti­miR­4530 plasmids and empty vector plasmids. Following this, it was revealed that overexpression of miR­4530 can suppress cell proliferation and enhance cell apoptosis. TargetScan analysis suggested that Ras p21 protein activator 1 (RASA1) is a target gene of miR­4530. The results of a dual­luciferase reporter assay also suggested that miR­4530 targets RASA1. Furthermore, the results of dual­luciferase reporter assay suggested that miR­4530 enhanced luciferase activity of the wild-type reporter, but not the mutant RASA1 reporter activity, thus suggesting that miR­4530 enhances the expression of RASA1. In addition, western blot analysis demonstrated that the protein expression level of RASA1 was enhanced following upregulation of miR­4530. The exact mechanism underlying this process has not yet been determined and requires further investigation. In addition, a RASA1 overexpression plasmid vector was transfected into HUVECs. The results suggest that overexpression of RASA1 suppresses cell growth and promotes apoptosis, which was in agreement with the results regarding the overexpression of miR­4530. To investigate how miRNA­4530 affects cellular function, numerous proteins associated with the extracellular signal­regulated kinase (ERK)/mitogen­activated protein kinase (MAPK) and phosphoinositide 3­kinase (PI3K)/AKT serine/threonine kinase pathways were investigated via western blot analysis. The results suggested that miRNA­4530 suppresses cell proliferation and enhances apoptosis by targeting RASA1 via the ERK/MAPK and PI3K/AKT signaling pathways.

MicroRNA-4530 promotes angiogenesis by targeting VASH1 in breast carcinoma cells.

The results of our previous study revealed that microRNA (miRNA/miR)-4530 was upregulated in the serum of patients with diabetic retinopathy. The TargetScan miRNA database was used to identify potential targets of miR-4530 and vasohibin-1 (VASH1) was predicted as one of the targets. The results of our previous study demonstrated that miR-4530 was able to promote angiogenesis in human umbilical vein endothelial cells. Therefore, suppressing miR-4530 may be a potentially novel approach towards inhibiting tumor angiogenesis. The present study aimed to investigate the function of miR-4530 and determine whether miR-4530 was able to regulate angiogenesis in breast carcinoma cells by targeting VASH1. MDA-MB-231 and MCF-7 cells were transfected with miR-4530 precursor, anti-miR-4530 and empty vector plasmids. The expression levels of miRNA and mRNA were detected using the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression levels of protein were detected using western blotting. Dual-luciferase reporter assays were used to identify the target of miR-4530. Furthermore, cell proliferation, cell cycle, apoptosis and tube formation assays were used to investigate the function of miR-4530 in vitro. Nude mice were used in a subcutaneous tumor model in vivo study. The results of the present study demonstrated that miR-4530 significantly suppressed proliferation and promoted apoptosis of breast carcinoma cells. In addition, miR-4530 expression promoted angiogenesis in vitro. Results from the western blotting and RT-qPCR revealed that VASH1 was significantly downregulated by miR-4530 in breast carcinoma cells. The results of the present study suggest that miR-4530 promotes angiogenesis, inhibits proliferation and induces apoptosis in breast carcinoma cells by suppressing the expression of VASH1.

[Gene expression of the key enzymes controlling starch synthesis and metabolism in rice grain endosperm under effects of high temperature after anthesis].

Taking an early-season indica cultivar 'Jiazao 935' whose grain quality was sensitive to temperature as test material, and by using artificial climatic chamber and real-time fluorescence quantitative PCR (FQ-PCR), this paper studied the relative expression amount and its dynamic changes of ten isoform genes of the key enzymes controlling starch synthesis and metabolism in rice grain endosperm, including sbe1, sbe3, and sbe4 of starch branching enzyme (SBE), isal, isa2, isa3, and pul of starch debranching enzyme (DBE), and Wx, sss1, and sss2a of starch synthase (SS), at the mean daily temperature 22 and 32 degrees C after anthesis. There existed obvious differences in the expression patterns of these genes under the high temperature stress, and the expression patterns were isoform-dependent. The relative expression amount of sbe1 and sbe3 under high temperature decreased significantly, and both of the genes were the sensitive isoform genes of SBE to high temperature stress. Among the DBE genes, pul was the isoform gene with high expression level, being more sensitive to high temperature stress than isa1, isa2, and isa3. Among the SS genes, sss2a had a significantly lower relative expression amount than sss1 and Wx, but sss2a and sss1 were more sensitive to high temperature than Wx, suggesting that sss2a and sss1 could be the important genes that adjusted the starch structure in rice endosperm under high temperature stress, especially at the middle and late grain filling stages.