miR-489 acts as a tumor suppressor in human gastric cancer by targeting PROX1

Dysregulation of microRNAs (miRNAs) are linked to tumorigenesis and tumor progression. In this study, we examined the expression of miR-489 in gastric cancer tissues and cells. Loss- and gain-of-function experiments were done to determine the roles of miR-489 in gastric cancer cell proliferation and invasion. Bioinformatic prediction, luciferase reporter assays, and Western blot analysis were employed to identify the target gene(s) of miR-489. We found that miR-489 was significantly (P < 0.05) downregulated in human gastric cancer tissues and cell lines, compared to their non-malignant counterparts. Enforced expression of miR-489 significantly suppressed gastric cancer cell proliferation and invasion, while miR-489 knockdown enhanced the aggressive behaviors of gastric cancer cells. Prospero homeobox 1 (PROX1) was identified to be a direct target of miR-489. A significant negative correlation was seen between miR-489 and PROX1 protein expression in gastric cancer tissues (r = -0.462, P = 0.023). Silencing of PROX1 phenocopied the suppressive effects of miR-489 in gastric cancer cells. Rescue experiments demonstrated that overexpression of a miR-489-resistant form of PROX1 significantly prevented the reduction in cell proliferation and invasion induced by miR-489 overexpression. In vivo studies confirmed that miR-489 overexpression retarded the growth of xenograft tumors, which was accompanied by reduced PROX1 expression. Overall, these data provide evidence for the suppressive activity of miR-489 in gastric cancer, which is ascribed to targeting of PROX1. The miR-489/PROX1 axis may represent a potential therapeutic target for this disease.

Upregulation of microRNA-34a enhances the DDP sensitivity of gastric cancer cells by modulating proliferation and apoptosis via targeting MET

Cisplatin (DDP) based chemotherapy is still the main strategy of human gastric cancer (GC) treatment. However, drug resistance is a major obstacle for DDP chemotherapy. Recent studies indicated that the resistance could be modulated by the regulation of dysregulated microRNAs (miRs). Previous study also found miR-34a was associated with cell proliferation and apoptosis in human GC; however, the relationship between miR-34a and DDP resistance still remains unexplored. The purpose of this study was to investigate whether miR-34a is associated with DDP resistance in human GC cells. Our study found that the expression of miR-34a was significantly decreased in DDP resistance human GC tissues and DDP resistance human GC SGC7901/DDP cells compared with normal GC tissues and cells. Upregulation of miR-34a enhanced the DDP sensitivity of SGC7901/DDP cells to DDP through the inhibition of cell proliferation and induction of cell apoptosis; on the other hand downregulation of miR-34a could weaken the DDP sensitivity of SGC7901 cells to DDP. Further study found that MET was a direct target of miR-34a and the regulation of MET could affect the DDP sensitivity of SGC7901/DDP cells. Moreover, our study also indicated that up-regulation of miR-34a could decrease the expression of MET in SGC7901/DDP cells. Therefore, our findings suggested miR-34a could modulate human gastric cancer cell DDP sensitivity by regulation of cell proliferation and apoptosis via targeting MET, potentially benefiting human GC treatment in the future.

Brief Questionnaire Derived from PANSS Using a General Probability Model to Assess and Monitor the Clinical Features of Schizophrenia

AIM

Patients with schizophrenia require continuous treatment much longer than the duration of their hospitalization, which makes their family members essential in their medical care. However, the evaluation of the disease state could only be done by professionals. This prompted us to seek potent indicators of disease states that are understandable and easy to use for the patients' family.

METHOD

Specific items were firstly extracted from the total PANSS scale. Then 3 096 PANSS scores were analyzed using a nonlinear mixed-effects model (NONMEM). A questionnaire was subsequently developed for family members to assess and monitor the overall severity of schizophrenia. Finally this questionnaire was validated in 33 patients.

RESULTS

2 items (P1 and N4) were extracted from the 8 effective remission items according to the correlation coefficients between the total PANSS score and different combinations of items. P1N4 was defined as the sum of these 2 items. A model was then developed to describe the probability of PANSS≥60, with P1N4 as indicators. The results indicated that P1N4 could make a good predictor of the overall probability of PANSS≥60, which was independent of treatment. A brief questionnaire with 7 questions was developed based on the results. External validation results indicated the questionnaire's suitability for a good assessment.

CONCLUSION

Questionnaire developed based on P1 and N4 may facilitate the patients' family members to better understand the disease state and help to prevent relapse.

Efficacy comparison between minimally invasive and conventional surgery for lumbar disc herniation in Chinese Han population: a meta-analysis

This corrects the article DOI: 10.1038/sc.2014.98.

Computer-aided analysis with Image J for quantitatively assessing psoriatic lesion area

BACKGROUND/AIMS

Body surface area is important in determining the severity of psoriasis. However, objective, reliable, and practical method is still in need for this purpose. We performed a computer image analysis (CIA) of psoriatic area using the image J freeware to determine whether this method could be used for objective evaluation of psoriatic area.

METHODS

Fifteen psoriasis patients were randomized to be treated with adalimumab or placebo in a clinical trial. At each visit, the psoriasis area of each body site was estimated by two physicians (E-method), and standard photographs were taken. The psoriasis area in the pictures was assessed with CIA using semi-automatic threshold selection (T-method), or manual selection (M-method, gold standard). The results assessed by the three methods were analyzed with reliability and affecting factors evaluated.

RESULTS

Both T- and E-method correlated strongly with M-method, and T-method had a slightly stronger correlation with M-method. Both T- and E-methods had a good consistency between the evaluators. All the three methods were able to detect the change in the psoriatic area after treatment, while the E-method tends to overestimate.

CONCLUSION

The CIA with image J freeware is reliable and practicable in quantitatively assessing the lesional of psoriasis area.

Efficacy comparison between minimally invasive and conventional surgery for lumbar disc herniation in Chinese Han population: a meta-analysis

STUDY DESIGN

The pooled data were analyzed using RevMan 5.2 software.

OBJECTIVES

The aim was to compare the efficacy of minimally invasive and conventional surgery for lumbar disc herniation (LDH) in Chinese Han population.

SETTING

China.

METHODS

An electronic search up to November 2013 was performed to retrieve all relevant articles. The overall standardized mean difference (SMD) for continuous outcomes and odds ratio (OR) for dichotomous variables as well as their 95% confidence intervals (CIs) were calculated to compare the efficacy of minimally invasive and conventional surgery.

RESULTS

A total of 23 studies involving 1913 patients treated by minimally invasive surgery and 2295 patients treated by conversational surgery were included in this meta-analysis. The overall estimate indicated that minimally invasive surgery could significantly decrease the hospitalization time (SMD = -2.03, 95% CI, -2.49 to 1.56, P < 0.0001), blood loss (SMD = -2.65, 95% CI -3.33 to 1.97, P < 0.0001), incision length (SMD = -3.57, 95% CI, -4.39 to 2.75, P < 0.0001), recurrence rate (odds ratio (OR) = 0.22, 95 CI: 0.08-0.60, P = 0.003) and complications (OR = 0.47, 95% CI: 0.25-0.92, P = 0.03) and increase the postoperative excellent rate (OR = 1.82, 95% CI, 1.44-2.31, P < 0.0001) compared with conventional surgery. In addition, the pooled data showed that there was no statistically significant difference in the operative time (SMD = -0.58, 95% CI, -1.32 to 0.15, P = 0.12) between LDH patients treated by minimally invasive and conventional surgery.

CONCLUSION

In conclusion, minimally invasive surgery was a more safe and effective treatment for treating LDH in Chinese Han population when compared with conventional surgery.

Isolation and characterization of Bacillus subtilis strain BY-3, a thermophilic and efficient cellulase-producing bacterium on untreated plant biomass

Bioconversion of biomass, particularly crop wastes, into biofuels is being developed as an alternative approach in meeting the high energy demand. In this study, a thermophilic bacterial strain BY-3 that exhibits cellulolytic potential was isolated from faecal samples of Tibetan pigs; this strain was identified as Bacillus subtilis. The strain can produce cellulase when grown on various substrates, including carboxymethyl cellulose, rice straw, corn stover, soluble starch and wheat bran. The maximum cellulase activity of the strain was up to 4·323 ± 0·065 U ml(-1) when cultivated in the medium containing corn stover (30 g l(-1) ) for 24 h. The results demonstrated that corn stover is the most suitable substrate for cellulase production by the strain BY-3. The crude cellulase of strain BY-3 was most active at pH 5·5 and 60°C, and the enzyme in acetate buffer (50 mmol l(-1) ) demonstrated a good stability at 60°C for at least 1 h. The crude cellulase exhibited a strong antibacterial activity against Staphylococcus aureus. The strain can be used in cost-efficient cellulase production for bioconversion of agricultural residual biomass into biofuels.

SIGNIFICANCE AND IMPACT OF THE STUDY

The increased consumption of fossil fuels has caused serious energy crisis and environmental problem. Thus, an alternative energy source is necessary. Bioconversion of biomass, particularly agricultural residuals, into value-added bioproducts, such as biofuels and chemical solvents, has received considerable attention. In this study, the newly isolated thermophilic Bacillus subtilis strain BY-3 produces cellulase efficiently with the use of untreated corn stover as a sole carbon source. This strain possesses the thermostable cellulase that is active with diverse crop wastes with a broad pH range and is a highly promising candidate for agricultural waste management.

Prevalence of carbapenem-hydrolyzing class D β-lactamase genes in Acinetobacter spp. isolates in China

In order to assess the prevalence of carbapenem-hydrolyzing class D β-lactamase genes in Acinetobacter spp. isolates in China, we conducted a polymerase chain reaction (PCR)-based surveillance of OXA-type β-lactamase gene clusters for a total of 2,880 Acinetobacter spp. isolates collected from 23 Chinese provinces. All isolates were tested for susceptibility to 12 antimicrobial agents and showed high rates of resistance to all these agents except minocycline. We also found that the vast majority of carbapenem-resistant Acinetobacter spp. were OXA-23-like-producing isolates, predominantly Acinetobacter baumannii isolates. Besides, bla OXA-58-like and bla OXA-24-like genes were detected in 32 and 11 isolates, respectively, involving many provinces throughout China. Furthermore, these two carbapenem-resistance determinants were located on transferable plasmids in most cases, indicating an emerging threat for both OXA-58-like- and OXA-24-like-producing Acinetobacter spp. isolates in China. Interestingly, a novel homologue of the bla OXA-143 gene was identified in a susceptible Acinetobacter pittii isolate. Overall, these observations suggest that the bla OXA-23-harboring A. baumannii isolates are the most frequent carbapenem-resistant Acinetobacter spp. in China, and the bla OXA-24-like and bla OXA-58-like genes have emerged as potential threats of hospital outbreaks of multidrug-resistant Acinetobacter spp.

Profilin 1 potentiates apoptosis induced by staurosporine in cancer cells

The correlation between the loss of Profilin 1 (Pfn1) with tumor progression indicated that Pfn1 is a tumor suppressor in human carcinoma. The molecular mechanisms underlying Pfn1 tumor suppression has yet to be elucidated. In this study, we showed that Pfn1 overexpression sensitizes cancer cells to apoptosis through the typical intrinsic apoptotic pathway. Mechanistically, the increased Pfn1 expression mediated the upregulation of p53R273H, one of the most common tumor-associated hotspot mutations of p53, with transactivation deletion in tumorigenesis and increased localization of p53R273H in cytoplasm. Further studies showed that mutant p53R273H was involved in apoptosis induced by Staurosporine (STS) via transcription-independent mitochondrial functions. We observed (i) the increased cytosolic localization of p53R273H, (ii) the activation of phosphorylation at Ser15, (iii) its mitochondrial localization; Pfn1 acted as a positive regulator of these processes. We also found that Pfn1 interacted with p53R273H and thus facilitated its exertion over the transcription-independent activity in the cytoplasm during drug action. Our results define a new function and mechanism of Pfn1 demonstrating that the combined effect with apoptotic agents led to a synergistic increase in apoptosis. In addition, p53R273H abrogating DNA binding was found to play a major role in the Pfn1- sensitized apoptosis through a transactivation-independent and cytosolic activity.

Up-regulation of MBD1 promotes pancreatic cancer cell epithelial-mesenchymal transition and invasion by epigenetic down-regulation of E-cadherin

Methyl-CpG binding domain protein 1 (MBD1) has been implicated in transcriptional regulation, heterochromatin formation, genomic stability, cell-cycle progression and development. It is also predicted that MBD1 might be involved in tumor development and progression. However, whether and how MBD1 is involved in tumorigenesis, especially in pancreatic cancer (PC), is currently unknown. We found that MBD1 was significantly up-regulated in PC tissues compared with the surrounding normal tissues according to RT-PCR data. Tissue microarray (TMA) based immunohistochemical study from 58 surgically resected PC specimens indicated that higher MBD1 expression correlated with lymph node metastasis and poor survival in PC patients. Gain- and loss-of-function studies in vitro validated MBD1 as a potent oncogene promoting PC cell invasion as well as epithelial-mesenchymal transition (EMT). Mechanistically, MBD1 is associated with Twist and NAD-dependent deacetylase sirtuin-1 (SIRT1), thereby forming the Twist-MBD1-SIRT1 complex on the CDH1 promoter, which resulted in reduced E-cadherin transcription activity and increased cell EMT ability. Significantly, targeting MBD1 reversed the EMT phenotype of PC and restored sensitivity to chemotherapy. Taken together, the results of our study revealed a novel function of MBD1 in PC invasion and metastasis by providing a molecular mechanism underlying MBD1-promoted EMT. Thus MBD1 may serve as a potential therapeutic target for PC.