Comprehensive analysis of the aberrantly expressed profiles of lncRNAs, miRNAs and the regulation network of the associated ceRNAs in clear cell renal cell carcinoma / 生物医学工程学杂志

To evaluate the differential expression profiles of the lncRNAs, miRNAs, mRNAs and ceRNAs, and their implication in the prognosis in clear cell renal cell carcinoma (CCRCC), the large sample genomics analysis technologies were used in this study. The RNA and miRNA sequencing data of CCRCC were obtained from The Cancer Genome Atlas (TCGA) database, and R software was used for gene expression analysis and survival analysis. Cytoscape software was used to construct the ceRNA network. The results showed that a total of 1 570 lncRNAs, 54 miRNAs, and 17 mRNAs were differentially expressed in CCRCC, and most of their expression levels were up-regulated (false discovery rate 2). The ceRNA regulatory network showed the interaction between 89 differentially expressed lncRNAs and 9 differentially expressed miRNAs. Further survival analysis revealed that 38 lncRNAs (including COL18A1-AS1, TCL6, LINC00475, UCA1, WT1-AS, HOTTIP, PVT1, etc.) and 2 miRNAs (including miR-21 and miR-155) were correlated with the overall survival time of CCRCC ( < 0.05). Together, this study provided us several new evidences for the targeted therapy and prognosis assessment of CCRCC.

A β-catenin/IQGAP1 regulatory feedback loop and its effects on the proliferation of colon cancer cells / 生物医学工程学杂志

The aim of this article is to study the regulatory feedback loop between β-catenin and IQ motif containing GTPase activating protein 1 (IQGAP1), as well as the effect of this regulation loop in colon cancer cell proliferation. Western blot was used to detect the expression of IQGAP1 and β-catenin after changing their expression respectively by transfection in SW1116 cells. CCK-8 cell proliferation assay was used to detect the effect of IQGAP1 involved in the proliferation of SW1116 cells promoted by β-catenin. The results of Western blot indicated that β-catenin could positively regulate IQGAP1, while IQGAP1 silencing could up-regulate β-catenin, forming a negative feedback loop. The results of CCK-8 showed that IQGAP1 silencing inhibited β-catenin-mediated proliferation in SW1116 cells. In conclusion, our research reveals a negative regulatory feedback loop between β-catenin and IQGAP1 which has a remarkable effect on the proliferation ability of colon cancer cells.

Identification of guanine nucleotide exchange factor ARHGEF 10 and its relationship with tumor malig-nant phenotype / 实用肿瘤学杂志

Objective The guanine exchange factors( GEFs) of Dbl family is a major regulatory unit for the malignant transformation of Rho family proteins. It plays a role by converting Rho protein from inactive GDP form to GTP form of Rho protein. In this paper,we discuss the structure and function of a GEF molecule-ARH-GEF 10,and discuss its role in the process of tumor development. Methods The expression of ARHGEF 10 in 42 normal tissues was measured by Real-Time PCR. GST-pulldown technique was used to detect the GEF ac-tivity of ARHGEF 10 in vivo. The transcription factor activity of downstream small molecules was detected by dual-luciferase report gene assay. The high expressive effect of ARHGEF 10 on normal cytoskeleton morphology was performed by dual immunofluorescence staining labeling method. High expressive effects of ARHGEF 10 on cell proliferation,invasion and tumorigenic ability in vitro were examined using CCK8,Transwell and soft agar clony formation assays. Results ARHGEF 10 has a typical GEFs structure,which binds to RhoA in vitro and promotes the proliferation and invasion of NIH3T3 cells,and has significant ability to clone in vitro. Conclusion ARH-GEF 10 is a typical family molecule of guanosine exchange factor that activates RhoA of Rho family,which has obvious oncogene characteristics.

RhoA regulates resistance to irinotecan by regulating membrane transporter and apoptosis signaling in colorectal cancer.

Colorectal cancer (CRC) is a major cause of mortality and morbidity worldwide. While surgery remains the mainstay of treatment in early stage CRC, chemotherapy is usually given to prolong the overall survival and improve the quality of life for metastatic colorectal cancer (mCRC). But drug resistance is one of the major hurdles of mCRC treatment, and the underlying mechanisms are still largely unknown. In this study, we show that, compared with parental cells, RhoA is up-regulated in irinotecan (CPT-11)-resistant CRC cells. Furthermore, inhibition of RhoA in drug resistant cells, at least partially, rescues the resistance against irinotecan and increases the sensitivity to other chemotherapeutic drug by inhibiting expression of MDR1, MRP1and GSTP1, promotes apoptosis by suppressing the expression of BCL-XL and Bcl-2 and increasing Bax expression, and significantly decreases side population cells. Our results suggest that, in addition to survival, proliferation, migration, adhesion, cell cycle and gene transcription, RhoA is also involved in chemoresistance by regulating the expression of membrane transporter and apoptosis protein in colorectal cancer. They raise an interesting possibility that the expression of RhoA may indicate a poor prognosis due to the high probability to therapy resistance and, on the other hand, inhibition of RhoA activity and function may overcome chemoresistance and improve the effectiveness of clinical treatment of CRC.