Search

Abstract: Background: We previously found that cyclophilin A (CypA) is overexpressed in human pancreatic cancer cells and stimulates cell proliferation through CD147. In this study, we further investigated the effect of CypA on gene expression of several key molecules that are involved in pancreatic cancer cell proliferation. Methods: Human pancreatic cancer cell lines (Panc-1, MIA PaCa-2, and BxPC-3) and human pancreatic ductal epithelial (HPDE) cells were used. The messenger RNA (mRNA) levels of CypA, CypB, CD147, neuropilins (NRPs), vascular endothelial growth factor (VEGF), and VEGF receptors upon the treatment of exogenous recombinant human CypA were determined by real-time reverse-transcription polymerase chain reaction. Results: Exogenous human recombinant CypA reduced the mRNA levels of NRP-1 and VEGF, but not endogenous CypA, CypB, and CD147, in Panc-1, MIA PaCa-2, and BxPC-3 cells. In contrast, HPDE cells showed a decrease of endogenous CypA and CD147 mRNA, but not detectable changes of CypB, NRPs, and VEGF mRNA levels upon exogenous CypA treatment. Conclusions: These data show that exogenous CypA downregulates NRP-1 and VEGF expression in pancreatic cancer cells. This effect is different in normal HPDE cells. Thus, soluble CypA may affect cell growth of pancreatic cancer. [Copyright &y& Elsevier]

Abstract: The first genetic factor identified for childhood asthma by genome-wide association study (GWAS) is the locus on chromosome 17q21, harboring the Orosomucoid 1-like 3 (ORMDL3) gene. ORMDL3 is implicated in facilitation of endoplasmic reticulum-mediated inflammatory responses, believed to underlie its association with asthma. In the present study, we demonstrated that mRNA expression of ORMDL3 is significantly increased in the peripheral blood of recurrent wheeze patients compared with normal control subjects by real-time RT-PCR. To elucidate the molecular mechanisms involved in human ORMDL3 regulation, we cloned and characterized the promoter region of ORMDL3. Applying 5′-rapid amplification of cDNA end analysis (RACE), we revealed that ORMDL3 gene used multiple transcriptional start sites (TSSs). Using a series of 5′ deletion promoter plasmids in luciferase reporter assays, we identified that the proximal minimal promoter of ORMDL3 was located within the region −84/+58 relative to the TSS. Mutational analysis, RNA interference experiments and sequential chromatin immunoprecipitation (ChIP) assay demonstrated that transcriptional activity of the ORMDL3 gene was cooperatively regulated by multiple transcription factors, including Ets-1, p300 and CREB. The expression levels of Ets-1, p300 and CREB were increased in the peripheral blood of recurrent wheeze patients compared with normal control subjects and showed a strong linear correlation with the expression of ORMDL3. Our findings indicate that Ets-1, p300 and CREB binding to the promoter region drive the ORMDL3 transcription. [Copyright &y& Elsevier]