A proteomic study of potential VEGF-C-associated proteins in bladder cancer T24 cells.

BACKGROUND: Overexpression of vascular endothelial growth factor-C (VEGF-C) has been found to play an important role in malignant progression of various cancer cells, in addition to lymphangiogenesis. However, the mechanisms involved are still largely unknown. Our early research has confirmed that the expression of VEGF-C in bladder cancer was markedly higher than that in normal bladder tissues. VEGF-C can also obviously promote proliferation and invasion of bladder cancer T24 cells. In the present work, we attempted to use proteomic analysis to screen out potential VEGF-C-associated proteins involved in malignant progression of the bladder cancer T24 cells. MATERIAL/METHODS: Lentivirus vector-based RNA interference (RNAi) was employed to diminish VEGF-C expression of bladder cancer T24 cells. Then we performed comparative proteome analysis to explore differentially expressed proteins in T24 cells with and without VEGF-C siRNA, by two-dimensional difference gel electrophoresis (2D-DIGE). RESULTS: Twenty-three proteins were identified. Some proteins (matrix metalloproteinase-9, Keratin 8, Serpin B5, Annexin A8) with significant differences were further confirmed by Western blotting. CONCLUSIONS: The 23 potential VEGF-C-associated proteins identified in our study provide us with further insights into the mechanism of VEGF-C promoting malignant progression of bladder cancer cells.

BMSC-derived exosomal lncRNA PTENP1 suppresses the malignant phenotypes of bladder cancer by upregulating SCARA5 expression.

LncRNAs can be transported to tumor cells where they exert regulatory effects by bone marrow mesenchymal stem cells (BMSC)-derived exosomes. Here, we aimed to investigate the functional mechanism of BMSC-derived exosomal lncRNA PTENP1 in the progression of bladder cancer (BC). Methods of BMSC were identified by detecting surface markers through flow cytometry. Exosomes from BMSC were identified by transmission electron microscopy, nanoparticle tracking analysis (NTA), and western blot analysis of exosome markers. Cellular internalization of BMSC-derived exosomes (BMSC-Exo) into BC cells was detected by confocal microscopy. CCK-8, colony formation, flow cytometry, wound healing, and transwell assays were adopted to estimate cell proliferation, apoptosis, migration, and invasion abilities, respectively. Interplay between miR-17 and lncRNA PTENP1 or SCARA5 was verified by dual-luciferase reporter, RNA pull down, and/or RNA immunoprecipitation (RIP) assays. Tumor xenograft assay was conducted in nude mice to study the role of exosomal lncRNA PTENP1 in BC progression in vivo. We showed exosomal lncRNA PTENP1 can be delivered into and suppress the malignant phenotypes of BC cells. LncRNA PTENP1 was identified as a sponge of miR-17, and SCARA5 was identified as a target gene of miR-17. The exosomes derived from PTENP1-overexpressing BMSC (BMSCOE-PTENP1-Exo) abolished the promotive effects of miR-17 overexpression or SCARA5 knockdown on the malignant phenotypes of BC cells. Moreover, exosomal lncRNA PTENP1 was demonstrated to inhibit BC tumor growth in nude mice by miR-17/SCARA5 axis. In conclusion, BMSC-derived exosomal PTENP1 suppressed the BC progression by upregulating the expression of SCARA5 via sponging miR-17, offering a potential novel therapeutic target for BC therapy.

miR­21 inhibits autophagy and promotes malignant development in the bladder cancer T24 cell line.

MicroRNA­21 (miR­21) is reported to exhibit cancer­promoting activity in various types of cancer. It has been previously demonstrated that miR­21 is overexpressed in bladder tumor tissue compared with normal mucosa. However, the functional mechanism of miR­21 in bladder cancer remains largely unknown. Thus, the current study aimed to determine the roles of miR­21 in autophagy and the malignant development of bladder cancer in T24 cells. Upregulation or downregulation of miR­21 was achieved following the transfection of miR­21 mimic or miR­21 inhibitor. An MTT assay was additionally performed to measure cell growth. Wound healing and transwell invasion assays were used to detect cell migration and invasion. The apoptotic potential and cell cycle were examined via flow cytometry and reverse transcription­quantitative PCR was performed to evaluate the expression of phosphatase and tensin homolog (PTEN), beclin 1, microtubule­associated protein l light chain 3B (LC3­II), cyclin D1, caspase­3, E­cadherin, matrix metallopeptidase­9 (MMP­9) and vimentin. The results revealed that the proliferation, migration and invasion of T24 cells was greatly increased in the miR­21 mimic group, while apoptosis was greatly inhibited. Additionally, T24 cells treated with miR­21 mimic exhibited G1­phase arrest. In the miR­21 mimic group, the expression of PTEN, beclin 1, LC3­II, caspase­3 and E­cadherin were decreased, while the expression of cyclin D1, MMP­9 and vimentin were increased. Opposite effects were observed in the miR­21 inhibitor group. The data of the current study may indicate that miR­21 overexpression inhibited autophagy and promoted the proliferation, migration, invasion and epithelial to mesenchymal transition of bladder cancer T24 cells. The results may further elucidate the molecular mechanism of miR­21 in the development of bladder cancer.

Role of 5-Aza-CdR in mitomycin-C chemosensitivity of T24 bladder cancer cells.

Chemotherapeutic insensitivity is one of key obstacles to effectively treating muscle invasive bladder cancer. 5-Aza-2'-deoxycytidine (5-Aza-CdR) has been identified as a tumor suppressive agent in various types of cancer. The aim of the present study was to identify the effects of 5-Aza-CdR on the mitomycin-C (MMC) chemosensitivity of T24 bladder cancer cells and investigate the underlying mechanisms. T24 cells were treated with a combination of MMC and 5-Aza-CdR at various concentrations. The rates of proliferation and apoptosis were assessed by an MTT assay and flow cytometry, respectively. The expression of drug resistance-associated proteins, including P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1), and autophagy-associated proteins, including beclin 1, nucleoporin 62 (p62) and autophagy protein 5 (ATG5) were detected with western blotting. Treatment with 5-Aza-CdR significantly promoted the MMC chemosensitivity of T24 cells. The proliferation of T24 cells was significantly inhibited with increasing 5-Aza-CdR concentration, whereas apoptosis was significantly increased. This was associated with the decreased expression of P-gp, MRP1, beclin 1, p62 and ATG5. In conclusion, 5-Aza-CdR enhanced MMC chemosensitivity in bladder cancer T24 cells, which may be caused by the suppression of drug resistance- and autophagy-associated proteins.

Expression and clinical significance of microRNA-21, maspin and vascular endothelial growth factor-C in bladder cancer.

The present study aimed to explore the expression and clinical significance of microRNA-21 (miR-21), maspin and vascular endothelial growth factor C (VEGF-C) in bladder cancer (BC). A total of 53 BC samples and 12 normal bladder tissue samples were collected. Total messenger RNA (mRNA) was extracted, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the expression of miR-21 and maspin in BC and normal bladder tissues. Immunohistochemistry was used for the detection of maspin and VEGF-C protein expression. Furthermore, the correlations between these molecules and certain clinicopathological parameters were investigated, and survival analysis was performed to assess their prognostic significance. miR-21 mRNA expression and VEGF-C protein expression were increased in BC tissues compared with those in normal bladder tissues, whereas maspin mRNA and protein expression levels in BC tissues were significantly decreased (P<0.01). miR-21, maspin and VEGF-C expression were significantly associated with the stage, grade and lymph node metastasis of BC (P<0.05), but not the other clinicopathological features evaluated. There was a marked inverse correlation between the mRNA expression of miR-21 and maspin, with a coefficient of -0.978 (P<0.001). Similarly, there was a significant inverse correlation between the protein expression of maspin and VEGF-C, with a coefficient of -0.589 (P<0.001). Overexpression of miR-21 and VEGF-C, as well as decreased maspin expression, were associated with a poorer prognosis. These results suggested that upregulation of miR-21, decreased maspin expression and enhanced VEGF-C in BC may promote tumor progression. miR-21, maspin and VEGF-C may therefore have significant roles as biomarkers for prognosis and as therapeutic targets of BC.

Clinical utility of fluorescence in situ hybridization for prediction of residual tumor after transurethral resection of bladder urothelial carcinoma.

OBJECTIVES: To evaluate the use of a multiprobe fluorescence in situ hybridization (FISH) assay for predicting the residual tumor load after transurethral resection (TUR) of bladder urothelial carcinoma (UC). METHODS: Voided urine specimens were collected from 125 consecutive patients with suspected UC who had been admitted for TUR. Of the 125 patients, 89 with UC diagnosed underwent a second procedure (repeated TUR or cystectomy) 4-6 weeks after the initial TUR and were included in the present study. Using the pathologic findings from the second procedure, the patients were divided into those with (n = 38) and those without (n = 51) residual tumor. Urine samples were taken both before and after the initial TUR. The multiprobe FISH assay was performed to detect aneuploidy of chromosomes 3, 7, and 17 and the loss of the 9p21 locus. RESULTS: Before the first TUR, no significant difference was found in the FISH-positive percentage between those with and without residual tumor. After the first TUR, the FISH-positive percentage in those with residual tumor was significantly greater than in those without residual tumor (42.2% vs 17.6%, P = .003). Moreover, before and after the initial TUR, the percentage of conversion from FISH positive to FISH negative in those with residual tumor was significantly lower than in those without residual tumor (28.9% vs 58.9%, P < .001). No patients were observed with a FISH result of conversion from negative to positive in those with and without residual tumor after the initial TUR. CONCLUSIONS: FISH appears to be useful for the prediction of the presence of the residual tumor load after TUR of bladder UC.