Targeting 5-Hydroxytryptamine receptor 1A in portal vein to decrease portal hypertension.

BACKGROUNDS & AIMS: Portal hypertension (PH) is one of the most frequent complications of chronic liver disease. The peripheral 5-Hydroxytryptamine (5-HT) level was increased in cirrhotic patients. We aimed to elucidate the function and mechanism of 5-HT receptor 1A (HTR1A) in portal vein (PV) on PH. METHODS: PH models were induced by thioacetamide (TAA) injection, bile duct ligation (BDL) or partial portal vein ligation (PPVL). HTR1A expression was detected using real-time PCR, in situ hybridization and immunofluorescence staining. In situ intraportal infusion was employed to assess the effects of 5-HT, the HTR1A agonist 8-OH-DPAT, and the HTR1A antagonist WAY-100635 on portal pressure (PP). Htr1a knock-out (Htr1a-/-) rats and vascular smooth muscle cell (VSMC)-specific Htr1a knock-out (Htr1aΔVSMC) mice were utilized to confirm the regulatory role of HTR1A on PP. RESULTS: HTR1A expression was significantly increased in the hypertensive PV of PH model rats and cirrhotic patients. Additionally, 8-OH-DPAT increased but WAY-100635 decreased PP in rats, without affecting liver fibrosis and systemic hemodynamics. Furthermore, 5-HT or 8-OH-DPAT directly induced the contraction of isolated PVs. Genetic deletion of Htr1a in rats and VSMCs-specific Htr1a knock-out in mice prevented the development of PH. Moreover, 5-HT triggered the cAMP pathway-mediated PVSMCs contraction via HTR1A in PV. We also confirmed alverine as an HTR1A antagonist and demonstrated its capacity to decrease PP in TAA-, BDL-, and PPVL-induced portal hypertensive rats. CONCLUSIONS: Our findings reveal that 5-HT promotes PH by inducing the contraction of PV, and identify HTR1A as a promising therapeutic target for attenuating PH. As an HTR1A antagonist, alverine is expected to become a candidate for clinical PH treatment.

circASS1 overexpression inhibits the proliferation, invasion and migration of colorectal cancer cells by regulating the miR-1269a/VASH1 axis.

Colorectal cancer (CRC), the third most common cancer worldwide, poses a threat to human life. However, its underlying mechanism is unclear and no satisfactory treatment is available. The present study aimed to investigate the role of circular RNA argininosuccinate synthase 1 (circASS1) in CRC cells and tissues to identify the potential mechanism underlying the pathogenesis of CRC. The expression of circASS1 in CRC cells and tissues was determined by reverse transcription-quantitative PCR. Following circASS1 overexpression in HT29 cells, cell viability, colony formation and apoptosis were measured using MTT, colony formation and TUNEL assays, respectively. Cell invasion and migration were also assessed. After confirming the associations among circASS1, microRNA (miR)-1269a and vasohibin 1 (VASH1), the characteristics of the HT29 cell line were assessed by performing the aforementioned assays. circASS1 expression was decreased in CRC cells and tissues, and circASS1 overexpression suppressed CRC cell proliferation, invasion and migration. circASS1 adsorbed miR-1269a and regulated its expression, and VASH1 was a target protein of miR-1269a. circASS1 overexpression decreased cell proliferation, invasion and migration, but enhanced cell apoptosis in HT29 cells, which was reversed by co-transfection with miR-1269a mimic or short hairpin RNA-VASH1. In conclusion, circASS1 overexpression inhibited CRC cell proliferation, invasion and migration by regulating miR-1269a/VASH1, which indicated a potential molecular mechanism underlying the pathogenesis of CRC.

MicroRNA­197 reverses the drug resistance of fluorouracil­induced SGC7901 cells by targeting mitogen­activated protein kinase 1.

MicroRNAs (miRNAs) are a group of small non­coding RNA molecules, which serve an important function in the development of multidrug resistance in cancer through the post­transcriptional regulation of gene expression and RNA silencing. In the present study, the functional effects of miR­197 were analyzed in chemo­resistant gastric cancer cells. Low expression levels of miR­197 were observed in the fluorouracil (5­FU)­resistant gastric cell line SGC7901/5­FU when compared with those in the parental gastric cell line SGC7901. Overexpression of miR­197 in SGC7901/5­FU cells was identified to partially restore 5­FU sensitivity. miRNA target prediction algorithms suggested that mitogen­activated protein kinase 1 (MAPK1) is a candidate target gene for miR­197. A luciferase reporter assay confirmed that miR­197 led to silencing of the MAPK1 gene by recognizing and then specifically binding to the predicted site of the MAPK1 mRNA 3'­untranslated region. When miR­197 was overexpressed in SGC7901 cells, the protein levels of MAPK1 were downregulated. Furthermore, MAPK1 knockdown significantly increased the growth inhibition rate of the SGC7901/5­FU cells compared with those in the control group. These results indicated that miR­197 may influence the sensitivity of 5­FU treatment in a gastric cancer cell line by targeting MAPK1.

Aberrant DNA methylation of P16, MGMT, hMLH1 and hMSH2 genes in combination with the MTHFR C677T genetic polymorphism in gastric cancer.

Associations of P16, MGMT, hMLH1 and hMLH2 with gastric cancer and their relation with MTHFR status in gastric patients who were confirmed with pathological diagnosis were assessed. Aberrant DNA methylation of P16, MGMT, hMLH1 and hMLH2 and polymorphisms of MTHFR C677T were assayed. The proportional DNA hypermethylation in P16, MGMT, hMLH1 and hMLH2 in cancer tissues was significantly higher than in remote normal-appearing tissues. DNA hypermethylation of P16 and MGMT was correlated with the T and N stages. Individuals with homozygotes (TT) of MTHFR C677T had significant risk of hypermethylation of MGMT in cancer tissues [OR (95% CI)= 3.47(1.41-7.93)]. However, we did not find association between polymorphism in MTHFR C677T and risk of hypermethylation in P16, MGMT, hMLH1 and hMLH2 genes either in cancer or remote normal-appearing tissues. Aberrant hypermethylation of P16, MGMT, hMLH1 and hMLH2 could be predictive of gastric cancer.