We assessed the effects of pulsatile flow shear stress on the gene expression profiles of human umbilical artery smooth muscle cells (HUASMCs) in vitro using the Express Chip DNA microarray method and investigated the difference between pulsatile and steady shear stress on differentially expressed genes of HUASMCs. In a modified pulsatile flow chamber system, HUASMCs were exposed to pulsatile and steady fluid shear stress (5.52 dyne/cm2) for 6 h respectively, and normal static cultured HUASMCs were selected as a control. The total cellular RNA was extracted by TRIzol Reagent (Life Technologies, Inc) according to the manufacturer's manual. Conversion of mRNA to single strand cDNA and double strand cDNA template was synthesized by Reverse Transcription from the total RNA. cRNA probe was transcribed with biotin labeling. After hybridization of probe with microarray, the binding of streptavidin to biotin was performed and amplified with the first antibody and further amplified with Cy3-conjugated second antibody. Then detection of Cy3 dye was carried out with ScanArray 5000. The results showed that a total of 1,330 genes revealed differential expression in HUASMCs exposed on pulsatile shear stress (5.52 dyne/cm2, 6 h); however, 2,676 genes revealed differential expression in HUASMCs exposed on steady shear stress. Comparsion of HUASMCs exposed to pulsatile with the HUASMCs exposed to steady shear stress showed there were 2,297 genes revealing differential expression. The transcriptional profile of fluidally induced genes in HUASMCs suggested a different response to pulsatile and steady shear stress.
Cells, Cultured ; Gene Expression Profiling ; Humans ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Oligonucleotide Array Sequence Analysis ; Pulsatile Flow ; RNA, Messenger ; biosynthesis ; genetics ; Stress, Mechanical ; Umbilical Arteries ; cytology

Objective To investigate the effects and molecular mechanisms of decorin(DCN),imatinib mesylate,and sunitinib malate on the malignant phenotype of gastrointestinal stromal tumor cells.Methods Western blotting was used to detect changes in the expres-sion of DCN and its downstream proteins after DCN overexpression and treatment with imatinib mesylate and sunitinib malate alone or in combination in gastrointestinal stromal tumor cells(GIST-882).Cell counting kit-8,scratch,and Transwell assays were performed to validate the changes in cell proliferation,migration,and invasion abilities after DCN overexpression and treatment with imatinib mesylate and sunitinib malate alone or in combination in GIST-882 cells.Results Compared with the control group,DCN overexpression and treatment with imatinib mesylate and sunitinib malate alone or in combination in GIST-882 cells increased the expression levels of DCN protein,decreased the expression levels of epidermal growth factor receptor(EGFR),phosphorylated EGFR(p-EGFR),extracellular signal-regulated kinase 1/2(ERK1/2),and phosphorylated ERK1/2(p-ERK1/2)proteins,and significantly reduced cell proliferation,migration,and invasion abilities.Conclusion DCN overexpression and treatment with imatinib mesylate and sunitinib malate alone or in combination affect the MAPK signaling pathway by downregulating the expression of EGFR,thereby regulating the proliferation,migra-tion,and invasion abilities of gastrointestinal stromal tumor cells.