MicroRNA­187 is an independent prognostic factor in lung cancer and promotes lung cancer cell invasion via targeting of PTRF.

MicroRNAs (miRNAs) are involved in the progression of different types of cancers giving new hope for cancer treatment. The role and regulatory mechanism of microRNA­187 (miR­187) are largely unknown. In the present study, 74 patients with non­small cell lung cancer (NSCLC) were selected. Tumor tissues and matched normal tissues were collected for determining the expression level of miR­187. Cell research was performed to detect the function of miR­187. The expression level was measured and miR­187 was found to be overexpressed in the NSCLC cell lines and tissues. Overexpression of miR­187 promoted cell proliferation in the A549 and H1650 cell lines. Moreover, overexpression of miR­187 also promoted cell migration and invasion. Polymerase I and transcript release factor (PTRF) was identified as a target of miR­187. Overexpression of miR­187 suppressed the expression of PTRF. Knockdown of PTRF promoted lung cancer cell invasion, and overexpression of PTRF had a negative effect on lung cancer cell invasion. The PTRF messenger RNA (mRNA) levels in cancer tissues were significantly lower than those in their adjacent normal lung tissues as determined by real­time PCR (RT­PCR). The expression of the PTRF protein was significantly weaker than that in the adjacent normal lung tissues using immunohistochemical staining. The findings revealed that miR­187 promotes cell growth and invasion by targeting PTRF and miR­187 may be a new prognostic factor for NSCLC.

Amlodipine prevents adriamycin-induced toxicity in cultured rat mesangial cells by up-regulation of Smad6, Smad7 expression.

Extensive studies have demonstrated that transforming growth factor-beta (TGF-ß) plays an important role in the progression of renal diseases. A central component of TGF-ß is the TGF-ß family-specific Smad signal transduction pathway. TGF-ß signals through Smad2, 4 to mediate renal fibrosis, whereas induction of Smad6, 7 inhibits renal fibrosis and inflammation. Amlodipine is the most frequently used antihypertensive drug among dihydropyridines. It is beneficial to the kidney and is widely used in treating kidney diseases. The aim of this study was to investigate effects of amlodipine on adriamycin-induced changes of lactate dehydrogenase (LDH) and expression of Smad6, 7 in rat mesangial cells. Results showed that amlodipine (10(-8) to 10(-5)mol/l) significantly decreased LDH activity in rat mesangial cells when given in combination with TGF-ß1 (P<0.01); amlodipine (10(-7), 10(-6)mol/l) significantly increased Smad6, 7 mRNA and protein expression in cells treated with adriamycin and TGF-ß1 (P<0.01). In conclusion, amlodipine protects against adriamycin-induced toxicity in rat mesangial cells by up-regulation of Smad6, 7 expressions.

Ligustrazine inhibits lipopolysaccharide-induced proliferation by affecting P27, Bcl-2 expression in rat mesangial cells.

Ligustrazine has a renoprotective effect against nephritis. In the present study, we investigated the roles of ligustrazine on lipopolysaccharide-induced changes of proliferation, cell cycle in cultured rat mesangial cells. 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay revealed that rat mesangial cells treated with lipopolysaccharide (10mg/l) underwent significant proliferation compared with control group. This effect was significantly inhibited by ligustrazine (400 to 2500 mg/l). Flow cytometric analysis revealed that cells treated with lipopolysaccharide showed significant reduction in the ratio of G0/G1 phase and significant elevation in the ratio of S+G2/M phase. The changes of cell cycle induced by lipopolysaccharide were reversed by ligustrazine. In addition, lipopolysaccharide suppressed P27 protein expression was significantly increased by ligustrazine (100, 500, 2500 mg/l). Moreover, rat mesangial cells treated with lipopolysaccharide showed scanty apoptosis with up-regulation of Bcl-2expression, while Bax protein expression was not changed. Ligustrazine (100, 500, 2500 mg/l) significantly reversed lipopolysaccharide-induced up-regulation of Bcl-2 protein and increased apoptotic cell death. In summary, ligustrazine displayed a significant inhibiting effect on lipopolysaccharide-induced proliferation through increasing P27 and decreasing Bcl-2 protein expression in rat mesangial cells.

Differential roles of dihydropyridine calcium antagonist nifedipine, nitrendipine and amlodipine on gentamicin-induced renal tubular toxicity in rats.

In the present study, we investigated the antioxidative potencies of dihydropyridine calcium antagonists prototype nifedipine, the second generation drug nitrendipine, and the long acting, third generation drug amlodipine on gentamicin-induced renal tubular toxicity in Sprague-Dawley rats. In addition, we analyzed the relationship between renal tubular cell apoptosis and the antioxidative properties of these dihydropyridine calcium antagonists. Results showed that treatment with gentamicin alone caused significant changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, and blood urea nitrogen. Nifedipine and amlodipine effectively reversed the effect of gentamicin on these parameters. In contrast, nitrendipine either had no effect or worsened gentamicin-induced changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, and blood urea nitrogen. Furthermore, gentamicin treatment caused significant increases in the levels of malondialdehyde, nitric oxide, nitric oxide synthase and significant decreases in the levels of reduced glutathione, glutathione-S-transferase, and superoxide dismutase in kidney tissues. These effects were dramatically reduced by nifedipine and amlodipine but not affected by nitrendipine. In addition to the biochemical changes, histopathological studies showed that gentamicin caused structural damages in the kidneys; renal tubular cell apoptosis, a decrease in Bcl-2 expression and an increase in Bax expression were observed in all rats treated with gentamicin, nifedipine and amlodipine effectively reversed the effect of gentamicin while nitrendipine worsened them. In conclusion, this study clearly indicated that nifedipine and amlodipine protected against gentamicin-induced nephrotoxicity while nitrendipine had little effect, or even worsened.