Bo Xie

miR-148a-3p represses proliferation and EMT by establishing regulatory circuits between ERBB3/AKT2/c-myc and DNMT1 in bladder cancer

miR-148a-3p downregulation has emerged as a critical factor in cancer progression yet, the underlying mechanisms of miR-148a-3p expression pattern and its function in bladder cancer remains to be elucidated. Here, we illustrate that miR-148a-3p is frequently downregulated in bladder cancer and that its expression may be regulated by DNA methylation. DNA methyltransferase 1 (DNMT1) and miR-148a-3p function in a positive feedback loop in bladder cancer. miR-148a-3p overexpression functions as a tumor suppressor in bladder cancer cells. miR-148a-3p inhibits bladder cancer cell proliferation and epithelial–mesenchymal transition (EMT) by regulating ERBB3/AKT2/c-myc and ERBB3/AKT2/Snail signaling. ERBB3, DNMT1 and AKT2 are downstream miR-148a-3p target genes. Furthermore, the miR-148a-3p/ERBB3/AKT2/c-myc signaling axis establishes a positive feedback loop in the regulation of bladder cancer. Taken together, our study demonstrates novel regulatory circuits involving miR-148a-3p/ERBB3/AKT2/c-myc and DNMT1 that controls bladder cancer progression, which may be useful in the development of more effective therapies against bladder cancer.

MicroRNA-608 inhibits proliferation of bladder cancer via AKT/FOXO3a signaling pathway

BackgroundCurrent evidence indicates that miR-608 is widely down-regulated in various malignant tumors including liver cancer, colon cancer, lung cancer and glioma, and acts as a tumor suppressor by inhibiting cell proliferation, invasion and migration or by promoting apoptosis. The specific biological function of miR-608 in bladder cancer is still unknown.MethodsqRT-PCR and Chromogenic in Situ Hybridization (CISH) was conducted to assess the expression of miR-608 in paired BCa tissues and adjacent non-tumor bladder urothelial tissues. Bisulfite sequencing PCR was used for DNA methylation analysis. CCK-8, colony formation and flow cytometry assays were performed, and a xenograft model was studied. Immunohistochemistry staining was performed with peroxidase and DAB. The target of miR-608 was validated with a dual-luciferase reporter assay, quantitative RT-PCR, and Western blotting.ResultsmiR-608 is frequently down-regulated in human BCa tissues. The methylation status of CpG islands is involved in the regulation of miR-608 expression. Overexpression of miR-608 inhibits the proliferation and tumorigenesis of BCa cells in vitro and in vivo. Additionally, up-regulation of miR-608 in BCa cells induces G1-phase arrest through AKT/FOXO3a signaling. In contrast, down-regulation of miR-608 promotes proliferation and cell cycle progression in BCa cells. Moreover, the expression of FLOT1 was directly inhibited by miR-608, the down-regulation of FLOT1 induced by siFLOT1 could be significantly reversed by miR-608 inhibitor. Similarly, the up-regulation of FLOT1 by FLOT1 overexpression plasmid (pFLOT1) could also reverse the suppressed cell proliferation caused by miR-608.ConclusionsmiR-608 is a potential tumor suppressor in BCa, and the restoration of miR-608 might be a promising therapeutic option for BCa.

Is magnetic resonance/ultrasound fusion prostate biopsy better than systematic prostate biopsy? an updated meta- and trial sequential analysis

We systematically reviewed the literature to determine whether Magnetic Resonance/Ultrasound (MR/US) fusion prostate biopsy is better than systematic biopsy for making a definitive diagnosis of prostate cancer. The two strategies were also compared for their ability to detect lesions with different degrees of suspicion on MRI and clinically significant prostate cancer, and the number of cores needed for diagnosis. The Cochrane Library, Embase, Web of Knowledge, and Medline were searched from inception until May 1, 2015. Meta-analysis was conducted via RevMan 5.2 software. Data was expressed as risk ratio (RR) and 95% confidence interval. Trial sequential analysis was used to assess risk of random errors. Fourteen trials were included, encompassing a total of 3105 participants. We found that MR/US fusion biopsy detected more prostate cancers than systematic biopsy (46.9% vs. 44.2%, p=0.03). In men with moderate/high MRI suspicion, MR/US fusion biopsy did better than systematic biopsy (RR = 1.46; p < 0.05) for making a diagnosis. Moreover, MR/US fusion biopsy detected more clinically significant cancers than systematic biopsy (RR = 1.19; p < 0.05). We recommend that MR/US fusion prostate biopsy be used to better detect prostate cancer, particularly in patients with moderate/high suspicion lesions on MRI.

MiR-22 suppresses epithelial–mesenchymal transition in bladder cancer by inhibiting Snail and MAPK1/Slug/vimentin feedback loop

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of bladder cancer (BCa). MiR-22 was previously reported to act as a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in BCa remain unclear. Here, we find that miR-22 is frequently downregulated in BCa tissues compared with adjacent non-cancerous tissues. Overexpression of miR-22 significantly inhibits proliferation, migration, and invasion of BCa cells both in vitro and in vivo. Importantly, miR-22 is found to suppress cell proliferation/apoptosis by directly targeting MAPK1 (mitogen-activated protein kinase 1, ERK2) and inhibit cell motility by targeting both MAPK1 and Snail. Further statistical analysis shows that low-expression of MAPK1 or Snail is an independent prognostic factor for a better overall survival in patients with BCa (n = 401). Importantly, we describe an important regenerative feedback loop among vimentin, Slug and MAPK1 in BCa cells. MAPK1-induced Slug expression upregulates vimentin. Vimentin in turn activates MAPK1. By inhibiting Snail and MAPK1/Slug/vimentin feedback loop, miR-22 suppresses epithelial–mesenchymal transition (EMT) of BCa cells in vitro as well as in vivo. Taken together, this study reveals that miR-22 is critical to the proliferation, apoptosis and EMT progression in BCa cells. Targeting the pathway described here may be a novel approach for inhibiting proliferation and metastasis of BCa.

MET|[sol]|SMAD3|[sol]|SNAIL circuit mediated by miR-323a-3p is involved in regulating epithelial|[ndash]|mesenchymal transition progression in bladder cancer

Bladder cancer (BCa) is the one of the most common cancers with high incidence, occurrence and low 5-year survival rate. Emerging evidence indicates that DLK1-DIO3 genomic region especially the miRNA cluster in this region is involved in several pathologic processes and various cancers, and miR-323a-3p is a member of this miRNA cluster. In this study, we investigate the function and regulatory network of miR-323a-3p in BCa. miR-323a-3p is frequently downregulated in BCa tissues and three cell lines compared with adjacent non-tumorous tissues and bladder normal cell line (SV-HUC-1). Besides, downregulation of miR-323a-3p is significantly associated with poor overall survival rate of BCa. Methylation of DLK1-MEG3 intergenic DMR (IG-DMR) contributes to the reduction of miR-323a-3p. Overexpression of miR-323a-3p significantly inhibits the epithelial–mesenchymal transition (EMT) progression of BCa. Both upregulated MET and SMAD3 are direct targets of miR-323a-3p, and the knockdown of MET and SMAD3 also represses the EMT progression consistently with overexpression of miR-323a-3p. SNAIL is detected in the last targeted confocal protein of both MET and SMAD3 signaling that trigger EMT consequently. Hence, a miR-323a-3p/MET/SMAD3/SNAIL circuit is established to regulate the EMT progression of BCa. And a mutual regulatory mechanism between miR-323a-3p/miR-433/miR-409 and MET also participates in this circuit. In conclusion, our study demonstrates a novel regulatory mechanism of the miR-323a-3p/MET/SMAD3/SNAIL circuit that is involved in the EMT regulation of BCa, which may be a potential therapy target for BCa.

Hypertension and risk of prostate cancer: a systematic review and meta-analysis

The previously reported association between hypertension and prostate cancer risk was controversial. We performed this systematic review and meta-analysis of all available studies to summarize evidence on this association. Studies were identified by searching PubMed, Web of Science and Chinese National Knowledge Infrastructure (CNKI) databases through January 2016. Pooled relative risks (RRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. A total of 21 published studies were included in this meta-analysis. A significant increase in the risk of prostate cancer (RR 1.08, 95% CI 1.02–1.15, P = 0.014) was observed among individuals with hypertension. There was statistically significant heterogeneity among included studies (P < 0.001 for heterogeneity, I2 = 72.1%). No obvious evidence of significant publication bias was detected by either Begg’s test (P = 0.174) or Egger’s test (P = 0.277). In conclusion, this meta-analysis indicates that hypertension may be associated with an increased risk of prostate cancer. Considering the substantial heterogeneity and residual confounding among included studies, further large-scale, well-designed prospective cohorts, as well as mechanistic studies, are urgently needed to confirm our preliminary findings.

c-Met, CREB1 and EGFR are involved in miR-493-5p inhibition of EMT via AKT/GSK-3β/Snail signaling in prostate cancer

miR-493-5p downregulation has emerged as a critical player in cancer progression yet, the underlying mechanisms of miR-493-5p expression pattern and its function in prostate cancer remains to be elucidated. Here, we illustrate that miR-493-5p is frequently downregulated in prostate cancer, at least partially due to altered DNA methylation. miR-493-5p functions as a tumor suppressor in prostate cancer cells. c-Met, CREB1 and EGFR are downstream target genes of miR-493-5p. miR-493-5p inhibits EMT via AKT/GSK-3β/Snail signaling in prostate cancer. Taken together, our study identified c-Met, CREB1, EGFR and miR-493-5p establish a regulatory loop in prostate cancer, which could prove useful in the development of effective and therapies against prostate cancer.miR-493-5p downregulation has emerged as a critical player in cancer progression yet, the underlying mechanisms of miR-493-5p expression pattern and its function in prostate cancer remains to be elucidated. Here, we illustrate that miR-493-5p is frequently downregulated in prostate cancer, at least partially due to altered DNA methylation. miR-493-5p functions as a tumor suppressor in prostate cancer cells. c-Met, CREB1 and EGFR are downstream target genes of miR-493-5p. miR-493-5p inhibits EMT via AKT/GSK-3β/Snail signaling in prostate cancer. Taken together, our study identified c-Met, CREB1, EGFR and miR-493-5p establish a regulatory loop in prostate cancer, which could prove useful in the development of effective and therapies against prostate cancer.

Body mass index and incidence of nonaggressive and aggressive prostate cancer: a dose-response meta-analysis of cohort studies

The relationship between body mass index (BMI) and incidence of prostate cancer is still inconclusive. We performed a dose-response meta-analysis of eligible cohort studies to evaluate potential association of BMI with prostate cancer risk by subtype of prostate cancer (nonaggressive and aggressive). A comprehensive literature search was performed in PubMed and Web of Science databases through March 22, 2017. Linear and non-linear dose-response meta-analyses were carried out to evaluate the effects of BMI on incidence of prostate cancer. A total of 21 cohort or nested case-control studies (17 for nonaggressive and 21 for aggressive prostate cancer) were included in this meta-analysis. For nonaggressive prostate cancer, the pooled relative risk (RR) per 5 kg/m2 increment of BMI with 95% confidence interval (CI) was 0.96 (95% CI 0.92–1.00). Sensitivity analysis indicated that this result was not robust and steady. For aggressive prostate cancer, a significant linear direct relationship with BMI (RR, 1.07; 95% CI 1.03–1.12) for every 5 kg/m2 increase was observed. Statistically significant heterogeneity was detected for nonaggressive prostate cancer (P = 0.020, I2 = 46.1%) but not for aggressive prostate cancer (P = 0.174, I2 = 22.4%). In conclusion, BMI level may be positively associated with aggressive prostate cancer risk. Further large prospective cohort studies are warranted to confirm the findings from our study.

CRISPR-ON-Mediated KLF4 overexpression inhibits the proliferation, migration and invasion of urothelial bladder cancer in vitro and in vivo

Kruppel like factor 4 (KLF4), a transcription factor associated with carcinogenesis and tumor progression, plays an important role in various malignancies. In the present study, we utilized the CRISPR-ON system to upregulate KLF4 expression level and subsequently investigated the effect and mechanism of KLF4 in the carcinogenesis and progression of urothelial bladder cancer (UBC). Immunohistochemistry (IHC) and quantitative RT-PCR (qRT-PCR) were used to evaluate the expression of KLF4. The CpG methylation status of the promoter region was analyzed using bisulfite-sequencing PCR (BSP). CRISPR-ON system comprised sgRNA and dCas9 protein combined with a transcriptional activation domain. The cell proliferation and cell cycle were assessed by CCK-8 assay, flow cytometry and colony formation assay. The cell motility ability was evaluated using trans-well assay. In vivo tumorigenesis assay and lung metastasis model were also performed. The KLF4 expression was significantly downregulated in UBC tissues. The high CpG methylation status in the promoter of KLF4 was confirmed using BSP. KLF4 overexpression was successfully achieved via CRISPR-ON system, which inhibited the proliferation and induced G1-phase arrest in T24 cells through the regulation of AKT/p21 signal. Furthermore, enforced expression of KLF4 also abrogated the migration and invasion of T24 cells by suppressing EMT progression. Finally, in vivo models indicated that the upregulation of KLF4 could inhibit tumorigenesis and lung metastasis in nude mice. In conclusion, KLF4 overexpression mediated by CRISPR-ON inhibits tumorigenesis and EMT progression in UBC cells, representing a potential therapeutic target, and CRISPR-ON system could be a therapeutic strategy for UBC in the future.

Pesticide exposure and risk of bladder cancer: A meta-analysis.

Objective We conducted a meta-analysis to quantitatively evaluate the correlation between pesticide exposure and the risk of bladder cancer by summarizing the results of published case-control and cohort studies. Methods A systematic literature search of articles update to February 2015 was conducted via Pubmed, Web of Science, Cochrane Library, and the Chinese National Knowledge Infrastructure (CNKI) databases, and the references of the retrieved articles. Fixed- or random-effect models were used to summarize the estimates of OR with 95% CIs for the highest versus the lowest exposure of pesticide. Results The pooled OR estimates indicated that pesticide exposure was associated with an increased risk of bladder cancer (OR=1.649, 95% CI 1.223-2.223). In subgroup analysis, we detected pesticide exposure demonstrated as a significant risk factor on bladder cancer in America (OR=1.741, 95% CI 1.270-2.388). Similar results were discovered in both case-control group and cohort group (OR=2.075, 95% CI 1.183-3.638, OR=1.146, 95% CI 1.074-1.223, respectively). No evidence of publication bias was found by Beggs or Eggers test (P = 0.210, P = 0.358, respectively). Conclusion In conclusion, our meta-analysis indicated that pesticide exposure was associated with an increased risk of bladder cancer. Further researches should be conducted to confirm the findings in our study and better clarify the potential biological mechanisms.