DGCR5 induces osteogenic differentiation by up-regulating Runx2 through miR-30d-5p.

BACKGROUND: Postmenopausal osteoporosis (PMOP) is a metabolic bone disease caused by unbalance between osteoblast bone formation and osteoclast bone resorption. In this study, the moderating effect of DGCR5 on osteogenic differentiation and its role in PMOP was assessed. METHODS: The expression levels of DGCR5, miR-30d-5p, and Runt-related transcription factor 2 (Runx2) mRNA and protein were determined by qRT-PCR and western blot, separately. The bone marrow human mesenchymal stem cells (hMSCs) were isolated from bone marrow of patients with PMOP or the healthy control. ALP activity and bone mineral density (BMD) were detected to reflect the osteogenic differentiation status. RIP and RNA pull-down assay were performed to explore the combination and interaction between DGCR5 and miR-30d-5p. RESULTS: Compared with the healthy control group (n = 20), DGCR5 was down-regulated in hMSCs from patients with PMOP (n = 20). Overexpression of DGCR5 induced osteogenic differentiation of hMSCs. DGCR5 up-regulated the expression of Runx2 through miR-30d-5p. DGCR5 up-regulated the expression of Runx2 through miR-30d-5p to induce osteogenic differentiation of hMSCs. CONCLUSION: DGCR5 negatively regulates miR-30d-5p, and it up-regulates Runx2 through miR-30d-5p, thereby inducing osteogenic differentiation of hMSCs, which may help to delay PMOP development.

[Anti-metastasis effect of thymoquinone on human pancreatic cancer].

Recent studies reported that thymoquinone (TQ), a component derived from the medicinal spice Nigella sativa (also called black cumin), exhibited inhibitory effects on cell proliferation of many cancer cell lines. This study was performed to investigate the anti-metastatic effect of thymoquinone on the pancreatic cancer in vitro and in vivo. The results showed that thymoquinone suppressed the migration and invasion of Panc-1 cells in a does-dependent manner. To investigate the possible mechanisms involved in these events, Western blotting analysis was performed, and found that thymoquinone significantly down-regulates NF-kappaB and MMP-9 in Panc-1 cells. In addition, metastatic model simulating human pancreatic cancer was established by orthotropic implantation of histologically intact pancreatic tumor tissue into the pancreatic wall of nude mice. And administration of thymoquinone significantly reduced tumor metastasis compared to untreated control. Furthermore, the expression of NF-kappaB and MMP-9 in tumor tissues was also suppressed after treatment with thymoquinone. Taken together, the results indicate that thymoquinone exerts anti-metastatic activity on pancreatic cancer both in vitro and in vivo, which may be related to down-regulation of NF-kappaB and its regulated molecules such as MMP-9 protein. Consequently, these results provide important insights into thymoquinone as an antimetastatic agent for the treatment of human pancreatic cancer.

CpG island methylator phenotype involving chromosome 3p confers an increased risk of non-small cell lung cancer.

PURPOSE: This study aims to explore the association of CpG island methylator phenotype (CIMP) involving tumor suppressor genes on short arm of chromosome 3 (3p) with increased risk of non-small cell lung cancer (NSCLC). METHODS AND MATERIALS: In this study, four NSCLC cell lines were cultured, and peripheral blood mononuclear cell (PBMC) specimens from 80 patients with NSCLC and 80 matched controls were collected for 3p-involved CIMP (3pCIMP) analysis. 3pCIMP was referred to as having at least three synchronously methylated genes of 3p per sample. Methylation-specific polymerase chain reaction was performed to examine the methylation status of each gene. DNA demethylation of NSCLC cell lines was achieved through the treatment with 5-aza-deoxycytidine. Logistic regression was used to assess odds ratios and 95% confidence intervals, which were adjusted for gender, age, and smoking status. RESULTS: Demethylation experiment showed that 3pCIMP status could play an important role in NSCLC cell proliferation. A total of 97.5% of PBMC specimens from NSCLC patients presented promoter methylation of any one of six genes (hOGG1, RAR-B, SEMA3B, RASSF1A, BLU, or FHIT) on 3p. Interestingly, 3pCIMP+ was found in 43.8% of NSCLC PBMC specimens and only in 6.3% of normal PBMC samples. The data suggest that 3pCIMP status is significantly associated with NSCLC and normal PBMC samples (p 0.001). More importantly, the results show that 3pCIMP positive carriers have a 12.8-fold increased risk of NSCLC (adjusted odds ratio, 12.8; 95% confidence interval, 4.38 -37.4, p 0.001) in Chinese population. CONCLUSIONS: This is the first evidence of an association between PBMC 3pCIMP and risk for NSCLC.

[Effects of high mobility group box-1 silencing upon the invasion and proliferation in human lung cancer cell L9981 by RNA inhibition].

OBJECTIVE: To investigate the effects of high mobility group box-1 (HMGB1) silencing upon the invasion and proliferation in human lung cancer cell L9981 by RNA inhibition. METHODS: L9981 cells were divided into 3 groups. Group 1 was transfected by HMGB1 small interfering RNA (HMGB1-siRNA group). Group 2 was transfected by negative sequence small interfering RNA (negative control group). Group 3 was blank group. The mRNA and protein of HMGB1 were determined by real-time PCR and Western blotting assay respectively. The proliferation ability was examined by cell viability assay. The growth status of cells was examined by MTT at 24, 48, 72 and 96 h post-transfection. Invasion ability was evaluated by Boyden chamber model. RESULTS: The relative expression of HMGB1 mRNA of HMGB1-siRNA group (1.0 +/- 0.0) was much lower than the negative control (12.8 +/- 1.3, P < 0.05) and blank groups (12.1 +/- 1.0, P < 0.05). HMGB1 protein expression was also significantly inhibited. Cell viability of HMGB1-siRNA group was much lower than other two groups. MTT indicated the growth of HMGB1-siRNA group was significantly inhibited than other two groups. Boyden chamber model indicated the number of penetrating membrane in HMGB1-siRNA group was less than other two groups. CONCLUSION: Down-regulating HMGB1 gene expression by HMGB1 siRNA can inhibit the invasion and proliferation of human lung cancer cell.