BACKGROUND:Studies have shown that human telomerase reverse transcriptase gene (hTERT) transfection can significantly extend the life cycle of bone marrow mesenchymal stem cels so that the cels can continue to maintain pluripotency.
OBJECTIVE:To investigate the effects of hTERT gene-modified bone marrow mesenchymal stem cels on hepatocyte proliferation and apoptosis.
METHODS:Bone marrow mesenchymal stem cels from rats were isolated and cultured using direct adherent method. Then, hTERT eukaryotic expression plasmid, pCIneo-hTERT, was transferred into the cels using liposome transfection method. The hTERT-modified bone marrow mesenchymal stem cels were co-cultured with hepatocytes at 1:1 (observation group), and meanwhile, non-transfected bone marrow mesenchyam stem cels were co-cultured with hepatocytes at 1:1 (control group), and hepatocytes cultured alone served as single culture group. Effects of bone marrow mesenchymal stem cels on hepatocyte proliferation and apoptosis were observed by MTT assay and immunofluorescence staining.
RESULTS AND CONCLUSION:The proliferative rate of hepatocytes was significantly higher in the observation group than the control and single culture groups (P < 0.05), and the survival rate of hepatocytes was significantly higher in the observation group than the single culture group (P < 0.05). Experimental findings suggest hTERT-modified bone marrow mesenchymal stem cels can inhibit hepatocyte apoptosis but promote hepatocyte proliferation, so as to improve hepatocyte function.

ObjectiveTo evaluate radio-frequency hemostasis in hepatectomy.MethodsFrom January 2009 to February 2011,the clinical data of 60 patients undergoing curative liver resection were divided into two groups using radio-frequency hemostasis (RFH) and clamp crushing method (CCM) respectively,RFH group (30 cases) and CCM group (30 cases).There was no difference between the 2 groups regarding the age,sex.hepatic function and tumor size.Data regarding the intra-operative and postoperative courses of the patients were analyzed.ResultsNo damage of hepatic vein occured in RFH group.Hepatic veins rupture occurred in 5 cases and massive bleeding occurred in 3 cases in CCM group.lntra-operative blood loss was significantly less in FRH group [ (219 ±62) ml] than in CCM group [ (416 ±96) ml ] (P ＜ 0.05 ).The postoperative drainage volume in RFH group was significantly less than that in CCM group on the third postoperative day.The serum ALT and T-BIL in RFH group was significantly lower than that in CCM group on postoperative day 1 and day 7 ( separately t =5.987,16.803,22.264,8.386,8.255,all P ＜0.05 ).Postoperative hepatic function in RFH group was significantly better than that in CCM group.ConclusionsThe use of radio-frequency hemostasis in hepatectomy is less traumatic,of less bleeding,faster recovery than clamp crashing method.

Objective To investigate the expressiorn of microRNA-622(miR-622) and dual specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2) in colon cancer tissues and cell lines and explore the effect of miR-622 on SW11l6 cells migration and invasion.Methods Eighty-two colon cancer tissues and paired para-tumor tissue specimens were collected.C.olon cancer cell line SW1116,SW480 and normal human colon epithelial cell line NCM460 were cultured.MiR-622 was detected by using Real time PCR,DYRK2 expression was measured by using immunohistochemistry,Real time PCR anid Western blot in tissue level and cell level,respectively.The relation of miR-622 and DYRK2 was analyzed by Pearson correlation analysis.miR-622 mimics transfection was conducted to up-regulate miR-622,while negative control,NC group were transfected with control sequence.Expression of DYRK2 was evaluated by using Real time PCR and Western blot,while Transwell chamber assays were used to assess the migration ability changes.Results Real time PCR and Western blot results showed that miR-622 mRNA was highly expressed in colorectal cancer tissue and colon cancer cell SW1116,whereas DYRK2 mRNA and protein were lowly expressed when compared with paracancerous tissue and normal colonic epithelial cell line NCM460.An obvious negative correlation was showed between miR-622 and DYRK2(r=0.916,P＜0.01).Compared to NC group,DYRK2 mRNA and protein expression were down-regulated after transfection of miR-622 mimics,which was observerd through Real time PCR and Western blot(P＜0.01).Correspondingly,compared to NC group,the migration ability of SW116 was remarkably enhanced after transfection of miR-622 mimics(P＜0.01).Conclusion The expression of miR-622 is high and DYRK2 is low in colon cancer.Up-regulation of miR-622 could negatively regulate DYRK2 expression and promote SW1116 cells migration.

Alternative polyadenylation(APA)is a crucial step in post-transcriptional regulation.Previous bioinformatic studies have mainly focused on the recognition of polyadenylation sites(PASs)in a given genomic sequence,which is a binary classification problem.Recently,computa-tional methods for predicting the usage level of alternative PASs in the same gene have been pro-posed.However,all of them cast the problem as a non-quantitative pairwise comparison task and do not take the competition among multiple PASs into account.To address this,here we propose a deep learning architecture,Deep Regulatory Code and Tools for Alternative Polyadenylation(DeeReCT-APA),to quantitatively predict the usage of all alternative PASs of a given gene.To accommodate different genes with potentially different numbers of PASs,DeeReCT-APA treats the problem as a regression task with a variable-length target.Based on a convolutional neural network-long short-term memory(CNN-LSTM)architecture,DeeReCT-APA extracts sequence features with CNN layers,uses bidirectional LSTM to explicitly model the interactions among com-peting PASs,and outputs percentage scores representing the usage levels of all PASs of a gene.In addition to the fact that only our method can quantitatively predict the usage of all the PASs within a gene,we show that our method consistently outperforms other existing methods on three different tasks for which they are trained:pairwise comparison task,highest usage prediction task,and rank-ing task.Finally,we demonstrate that our method can be used to predict the effect of genetic variations on APA patterns and sheds light on future mechanistic understanding in APA regulation.

The accurate annotation of transcription start sites(TSSs)and their usage are critical for the mechanistic understanding of gene regulation in different biological contexts.To fulfill this,specific high-throughput experimental technologies have been developed to capture TSSs in a genome-wide manner,and various computational tools have also been developed for in silico pre-diction of TSSs solely based on genomic sequences.Most of these computational tools cast the problem as a binary classification task on a balanced dataset,thus resulting in drastic false positive predictions when applied on the genome scale.Here,we present DeeReCT-TSS,a deep learning-based method that is capable of identifying TSSs across the whole genome based on both DNA sequence and conventional RNA sequencing data.We show that by effectively incorporating these two sources of information,DeeReCT-TSS significantly outperforms other solely sequence-based methods on the precise annotation of TSSs used in different cell types.Furthermore,we develop a meta-learning-based extension for simultaneous TSS annotations on 10 cell types,which enables the identification of cell type-specific TSSs.Finally,we demonstrate the high precision of DeeReCT-TSS on two independent datasets by correlating our predicted TSSs with experimentally defined TSS chromatin states.The source code for DeeReCT-TSS is available at https://github.-com/JoshuaChou2018/DeeReCT-TSS_release and https://ngdc.cncb.ac.cn/biocode/tools/BT007316.

Overexpression of exogenous lineage-determining factors succeeds in directly reprogramming fibroblasts to various cell types. Several studies have reported reprogramming of fibroblasts into induced cardiac progenitor cells (iCPCs). CRISPR/Cas9-mediated gene activation is a potential approach for cellular reprogramming due to its high precision and multiplexing capacity. Here we show lineage reprogramming to iCPCs through a dead Cas9 (dCas9)-based transcription activation system. Targeted and robust activation of endogenous cardiac factors, including GATA4, HAND2, MEF2C and TBX5 (G, H, M and T; GHMT), can reprogram human fibroblasts toward iCPCs. The iCPCs show potentials to differentiate into cardiomyocytes, smooth muscle cells and endothelial cells . Addition of MEIS1 to GHMT induces cell cycle arrest in G2/M and facilitates cardiac reprogramming. Lineage reprogramming of human fibroblasts into iCPCs provides a promising cellular resource for disease modeling, drug discovery and individualized cardiac cell therapy.