Tianxin Lin

MicroRNA‐125b suppresses the development of bladder cancer by targeting E2F3

Increasing evidence has suggested that dysregulation of certain microRNAs (miRNAs) may contribute to tumorigenesis. microRNA‐125b (miR‐125b) was implicated to have close relationship with cell proliferation and differentiation, and downregulation of miR‐125b was observed in various types of cancers. However, the biological function of miR‐125b in bladder tumorigenesis is still unknown. In our study, we showed that the expression of miR‐125b was significantly decreased in bladder cancer tissues and four bladder cancer cell lines. Moreover, miR‐125b could suppress bladder cancer cells to form colonies in vitro and to develop tumors in nude mice. E2F3, which was critical for G1/S transition and was overexpressed in most of poor‐differentiated bladder cancers, was identified as a target of miR‐125b by luciferase assay. The E2F3 mRNA and protein expression levels were detected in bladder cancer tissues and cell lines, and interestingly, inverse correlations between miR‐125b and E2F3 protein level were found in bladder cancer tissues and four E2F3 nonamplified cell lines. Introduction of miR‐125b could reduce the expression of E2F3 protein but not the E2F3 mRNA. In addition, we observed that transfection of miR‐125b could inhibit the expression of Cyclin A2, one of the E2Fs‐responsive genes involved in G1/S transition. These results suggest that miR‐125b may regulate G1/S transition through the E2F3–Cyclin A2 signaling pathway. Taken together, miR‐125b may act as a tumor suppressor in bladder urothelium, and downregulation of miR‐125b may contribute to the tumorigenesis of bladder cancer.

Laparoscopic Radical Cystectomy with Orthotopic Ileal Neobladder for Bladder Cancer: Oncologic Results of 171 Cases With a Median 3-Year Follow-up

BACKGROUND Radical cystectomy (RC) with pelvic lymph node dissection (PLND) is the standard treatment for muscle-invasive and high-risk non-muscle-invasive bladder cancer (BCa). Large series with long-term oncologic data after laparoscopic RC (LRC) are rare. OBJECTIVE To report oncologic outcomes of LRC for 171 cases with a median 3-yr follow-up. DESIGN, SETTING, AND PARTICIPANTS From December 2002 to June 2009, 171 consecutive patients with BCa who underwent LRC with orthotopic ileal neobladder (OIN) at our institution were enrolled in this retrospective study. INTERVENTION All patients underwent LRC OIN. Adjuvant chemotherapy was administered to patients with non-organ-confined disease or positive lymph nodes. MEASUREMENTS The demographic, perioperative, complication, pathologic, and survival data were collected and analysed. RESULTS AND LIMITATIONS Most tumours were transitional cell carcinoma (TCC; 160, 93.6%). Tumours were organ confined in 113 patients (pT1-T2; 66.1%) and non-organ confined in 58 patients (pT3-T4a; 33.9%). There was involvement of the lymph nodes in 38 patients (22.2%). Surgical margins were all tumour free. The mean number of removed lymph nodes was 16 (5-46). Follow-up ranged from 3 to 83 mo, and 54 (31.6%) patients completed 5-yr follow-up. Two patients (1.2%) had local recurrence and distant metastasis, 9 patients (5.3%) had local recurrence alone, and 23 patients (13.5%) had distant metastasis. One patient (0.6%) had port-site seeding. One hundred twenty-four patients (72.5%) were alive with no evidence of recurrence; 28 patients (16.4%) died, 20 from metastasis and 8 from tumour-unrelated causes. The estimated 5-yr overall survival, cancer-specific survival, and recurrence-free survival rates were 73.7%, 81.3%, and 72.6%, respectively. The relatively low percentage of patients reaching 5-yr follow-up is a limitation of this retrospective study. CONCLUSIONS Surgical technique of LRC with OIN can achieve the established oncologic criteria of open surgery, and our oncologic outcome is encouraging. Long-term follow-up is needed for further confirmation.

linc-UBC1 physically associates with polycomb repressive complex 2 (PRC2) and acts as a negative prognostic factor for lymph node metastasis and survival in bladder cancer

OBJECTIVES The human genome encodes many long intergenic noncoding RNAs (lincRNAs). However, their biological functions, molecular mechanisms and prognostic values associated with bladder cancer remain to be elucidated. Here we investigated a lincRNA termed linc-UBC1 (Up-regulated in bladder cancer 1) and evaluated its prognostic value in bladder cancer patients. MATERIALS AND METHODS Expression of linc-UBC1 was evaluated by quantitative reverse transcription PCR (qRT-PCR) in 102 bladder cancer tissue samples and normal adjacent tissues. The functions of linc-UBC1 on cell proliferation, migration, invasion, colony formation, tumorigenicity and metastatic potential were evaluated by knockdown strategy in vitro and in vivo. RNA immunoprecipitation (RIP) was performed to confirm that linc-UBC1 physically associates with EZH2 and SUZ12, core components of polycomb repressive complex 2 (PRC2). Chromatin immunoprecipitation (ChIP) was conducted to examine histone modification status. RESULTS qRT-PCR confirmed that linc-UBC1 expression is up-regulated in 60 cases (58.8%) in bladder cancer tissues compared with normal adjacent tissues, and its overexpression correlates with lymph node metastasis and poor survival. Further functional analysis demonstrated that knockdown of linc-UBC1 attenuates bladder cancer cell proliferation, motility, invasion, colony formation ability, tumorigenicity and metastatic potential. Importantly, the inhibitory effect of linc-UBC1 on cell proliferation was also observed in primary bladder cancer cells obtained from patients. RIP and ChIP assay confirmed that linc-UBC1 physically associates with PRC2 complex and regulates histone modification status of target genes. CONCLUSIONS Frequently overexpressed linc-UBC1 physically associates with PRC2 complex, and acts as a negative prognostic factor for lymph node metastasis and survival in bladder cancer.

Systematic review and meta-analysis of comparative studies reporting early outcomes after robot-assisted radical cystectomy versus open radical cystectomy

BACKGROUND Robot-assisted radical cystectomy (RARC) is increasingly being used in the management of bladder cancer. Studies comparing RARC and open radical cystectomy (ORC) have reported conflicting results. We conducted a systematic review and meta-analysis of the literature on the efficacy and advantages of RARC compared with ORC. METHODS An electronic database search of PubMed, Scopus, and the Cochrane Library was performed up to July 8, 2012. This systematic review and meta-analysis was performed based on all randomized controlled trials (RCTs) and observational comparative studies assessing the two techniques. RESULTS One RCT, eight studies with prospectively collected data, and four retrospective studies were identified, including 962 cases. Although RARC was associated with longer operative time (p<0.001), patients in this group might benefit from less overall perioperative complications (p=0.04), more lymph node yield (p=0.009), less estimated blood loss (p<0.001), a lower need for perioperative transfusion (p<0.001), and shorter length of hospital stay (p<0.001). Positive surgical margins did not differ significantly between techniques. Sensitivity analysis with prospective studies showed similar results to the original analysis, but no significant difference of lymph node yield and length of stay between two techniques. CONCLUSIONS RARC is a mini-invasive alternative to ORC with less overall perioperative complications, more lymph node yields, less estimated blood loss, less need for a perioperative transfusion, and shorter length of stay.

Up-regulated microRNA-143 in cancer stem cells differentiation promotes prostate cancer cells metastasis by modulating FNDC3B expression

BackgroundMetastatic prostate cancer is a leading cause of cancer-related death in men. Cancer stem cells (CSCs) are involved in tumor progression and metastasis, including in prostate cancer. There is an obvious and urgent need for effective cancer stem cells specific therapies in metastatic prostate cancer. MicroRNAs (miRNAs) are an important class of pervasive genes that are involved in a variety of biological functions, especially in cancer. The goal of this study was to identify miRNAs involved in prostate cancer metastasis and cancer stem cells.MethodsA microarray and qRT-PCR were performed to investigate the miRNA expression profiles in PC-3 sphere cells and adherent cells. A transwell assay was used to evaluate the migration of PC-3 sphere cells and adherent cells. MiR-143 was silenced with antisense oligonucleotides in PC-3, PC-3-M and LNCaP cells. The role of miR-143 in prostate cancer metastasis was measured by wound-healing and transwell assays in vitro and bioluminescence imaging in vivo. Bioinformatics and luciferase report assays were used to identify the target of miR-143.ResultsThe expression of miR-143 and the migration capability were reduced in PC-3 sphere cells and progressively increased during sphere re-adherent culture. Moreover, the down-regulation of miR-143 suppressed prostate cancer cells migration and invasion in vitro and systemically inhibited metastasis in vivo. Fibronectin type III domain containing 3B (FNDC3B), which regulates cell motility, was identified as a target of miR-143. The inhibition of miR-143 increased the expression of FNDC3B protein but not FNDC3B mRNA in vitro and vivo.ConclusionsThese data demonstrate for the first time that miR-143 was up-regulated during the differentiation of prostate cancer stem cells and promoted prostate cancer metastasis by repressing FNDC3B expression. This sheds a new insight into the post-transcriptional regulation of cancer stem cells differentiation by miRNAs, a potential approach for the treatment of prostate cancer.

Effective enrichment of prostate cancer stem cells from spheres in a suspension culture system.

BACKGROUND Stem-like prostate cancer cells are also called prostate cancer stem cells (PrCSCs). These rare cells are supposed to be highly tumorigenic and to be involved in maintenance of tumor homeostasis and mediation of tumor metastasis. Methods for sorting PrCSCs are mainly based on sorting cells with the marker (CD133(+)/CD44(+)) or side population cells. However, CD133(+)/CD44(+) cells or side population cells are very rare or even undetectable. The scarcity of approaches for isolation and purification of PrCSCs is the main obstacle to studying PrCSCs. METHODS In the present study, suspension culture was used for enrichment of PrCSCs. And PrCSCs were verified by side population technology, drug sensitivity assays, and the molecular marker analysis of prostate cancer stem cell. RESULTS PC3 cells survived and formed spheres in nonadherent suspension culture. The percentage of CD44(+)/CD133(+) cells was 18-fold higher in the nonadherent sphere-forming cell population than in the adherent PC3 cell population (13.94% vs. 0.77%, respectively). This side population was increased to 3.1% in the nonadherent population but undetectable in adherent population. Resistance to cisplatin was higher in the nonadherent cells than adherent cells. CONCLUSION Suspension culture can be used to enrich for PrCSCs. This approach will aid prostate stem cell biology research and facilitate identification of novel therapeutic agents for prostate cancer.

Comparison of transperitoneal and retroperitoneal laparoscopic nephrectomy for renal cell carcinoma: a systematic review and meta-analysis

Laparoscopic nephrectomy is now considered to be the reference procedure for kidney cancer. It can be performed via a transperitoneal or retroperitoneal approach. Each approach has its advantages and disadvantages. No definitive conclusions regarding objective difference between the two approaches have been reached to date. This meta‐analysis indicates that in appropriately selected patients, especially patients with posteriorly located renal tumors, the retroperitoneal approach may be faster and equally safe compared with the transperitoneal approach.

Cell-to-cell contact induces human adipose tissue-derived stromal cells to differentiate into urothelium-like cells in vitro.

Human adipose-derived stromal cells (hASCs) are capable of multi-lineage differentiation. Co-culture of stem cells with mature cells or tissues can drive their differentiation toward required lineages. We investigated whether direct cell-to-cell contact between hASCs and human UCs, or soluble signaling molecules, could induce the differentiation of hASCs into urothelium-like cells in vitro. hASCs were isolated from human subcutaneous adipose tissue and amplified in vitro. After labeled by green fluorescent protein, hASCs were cultured with human UCs in direct co-culture, indirect co-culture and conditioned culture, respectively. Two weeks later, expressions of specific urothelial differentiation markers were analyzed by RT-PCR and immunofluorescence. We found that hASCs in direct co-culture expressed urothelial-specific genes uroplakin Ib, uroplakin II and cytokeratin 18. However, uroplakin III gene was not detected during the experimental period. Additionally, uroplakin Ib and cytokeratin 18 were observed in differentiated hASCs by immunofluorescence. Notably, none of these markers were detected in hASCs cultured in indirect co-culture and conditioned culture. These findings suggest that direct cell-to-cell contact between hASCs and human UCs can induce the differentiation of hASCs along urothelial lineage.

Laparoscopic Radical Cystectomy with Orthotopic Ileal Neobladder: A Report of 85 Cases

PURPOSE The preliminary results of laparoscopic radical cystectomy in 85 patients are presented in this study. The functional and oncologic outcomes of this procedure in these patients are discussed. PATIENTS AND METHODS Between December 2002 and May 2006, we performed 85 laparoscopic radical cystectomies with orthotopic ileal neobladder for bladder cancer in 77 men and 8 women. A 5-port transperitoneal approach was applied. The standard bilateral pelvic lymphadenectomy was performed first, then radical cystectomy was completed laparoscopically. The construction of the ileal neobladder and the anastomosis of ureter-neobladder were performed extracorporeally. The neobladder was anastomosed to the urethral stump under laparoscopy. A nerve-sparing procedure was performed for eight patients. RESULTS The median operative time was 320 min, and the median blood loss was 280 mL. Conversion to open surgery was not necessary in any of the patients. The average time to oral intake after operation was 3.9 days. There were no perioperative mortalities. The complication rate was 14.1% (12/85), including such complications as three uretero-pouch anastomotic strictures, one vesicourethral anastomotic stricture, one pouch-vaginal fistula, one colonic pouch fistula, one ileo-pouch fistula, three ileus, one pneumonia, and one pyelonephritis. The daytime continence rate was 91.2%, and the nighttime continence rate was 82.4% at 6 months postoperatively. The neobladder capacity was about 343 mL. Surgical margins were tumor free for all patients. Of the eight patients who underwent a nerve-sparing procedure, four patients had potency for intercourse. During a follow-up period of 1 to 41 months (average 21.3 months), three patients had local recurrence, one patient had trocar site seeding, and five patients had distant metastasis, of whom four died. CONCLUSIONS Laparoscopic radical cystectomy with extracorporeal formation of a neobladder is a feasible procedure with low morbidity and acceptable neobladder function. Long-term follow-up is needed to confirm the oncologic outcomes.

CD103+ Tumor Infiltrating Lymphocytes Predict a Favorable Prognosis in Urothelial Cell Carcinoma of the Bladder.

PURPOSE CD8(+) TILs at different tumor sites have diverse clinical attributes, which might result from distinct tumor microenvironments that promote differentiation into distinct subsets. However, only a few markers have been identified that can define CD8(+) T-cell subsets. CD103 is a marker of tissue resident memory CD8(+) T cells. In this retrospective study we investigated the cellular source and clinical significance of CD103 expression in urothelial cell carcinoma of bladder tissues in situ. MATERIALS AND METHODS Immunohistochemistry and immunofluorescence were used to identify the cellular source of CD103 in bladder urothelial cell carcinoma tissues. Kaplan-Meier analysis and Cox proportional hazards regression models were applied to estimate overall and recurrence-free survival in 302 patients with bladder urothelial cell carcinoma. RESULTS CD8(+) T cells but not natural killer cells accounted for most CD103 expressing cells in bladder urothelial cell carcinoma tissues. Notably CD103(+) cells were predominantly located in intratumor regions rather than in associated stroma (p < 0.0001). The density of intratumor CD103(+) TILs was inversely associated with tumor size (p < 0.0001) and could represent a favorable prognostic predictor of overall and recurrence-free survival (p = 0.002 and 0.011, respectively). Moreover, intratumor CD103(+) TILs were positively associated with the expression of cognate ligand E-cadherin in intratumor regions of bladder urothelial cell carcinoma tissues (p = 0.008). CONCLUSIONS Our findings suggest that CD8(+) T cells might have a significant role in tumor immunity by expressing CD103 in intratumor regions of bladder urothelial cell carcinoma tissues. Intratumor CD103(+) TILs could potentially serve as a prognostic marker in patients with bladder urothelial cell carcinoma.