glutaminase and Urinary-Bladder-Neoplasms

Long intergenic non-coding RNA p21 (lincRNA-p21) is down-regulated in some solid tumors. Glutamine catabolism plays an important role in cancer development. However, the role of lincRNA-p21 and its association with glutamine catabolism remain unknown in bladder cancer (BC). In the present study, we investigated the involvement of lincRNA-p21 and glutamine catabolism in BC cell growth and found that ectopic linRNA-p21 expression reduced the proliferation and growth of BIU87 and 5637 cells. Opposite results were observed in lincRNA-p21 silenced J82 and T24 cells. The expression of glutaminase (GLS), intracellular level of glutamate and α-Ketoglutarate (α-KG) were negatively regulated by lincRNA-p21. GLS overexpression reversed the suppressive function of lincRNA-p21 on BC cell growth and proliferation. In contrast, GLS reduction by siRNA blunted the viability of lincRNA-p21 lowly expressed BC cells. Furthermore, lincRNA-p21 and GLS abundance dictated the sensitivity of BC cells to bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide (BPTES) treatment. Importantly, reduced lincRNA-p21 expression and increased GLS mRNA level were observed in BC tissues compared with the normal tissues. Our results demonstrate that lincRNA-p21 suppresses the BC cell growth through inhibiting GLS and glutamine catabolism. Targeting this cascade may be a promising treatment strategy for BC patients.

Topics: Cell Line, Tumor; Cell Proliferation; Down-Regulation; Gene Expression Regulation, Neoplastic; Glutaminase; Glutamine; Humans; RNA, Long Noncoding; Urinary Bladder Neoplasms

Increasing evidence showed that miR-1-3p plays a major role in malignant tumor progression. However, the specific biological function of miR-1-3p in bladder cancer is yet unknown.. The expression levels of miR-1-3p in bladder cancer tissues and cell lines were examined by qRT-PCR. Bisulfite sequencing PCR was used for DNA methylation analysis. The target of miR-1-3p was validated by a dual luciferase reporter assay, and the effects of miR-1-3p on phenotypic changes in bladder cancer cells were investigated in vitro and in vivo.. The expression of miR-1-3p in bladder cancer cells was downregulated as compared to normal SV-HUC-1 cells. Also, the expression of miR-1-3p was significantly lower in bladder cancer tissues than the corresponding non-cancerous tissues. The methylation status of CpG islands was involved in the regulation of miR-1-3p expression. miR-1-3p inhibited the bladder cancer cell proliferation, migration, and invasion by directly targeting the 3'-UTR of glutaminase. It also exerted an anti-tumor effect by negatively regulating the glutaminase in a xenograft mouse model. Furthermore, GLS depletion resulted in the prolonged expression of γH2AX.. Taken together, these results demonstrated that miR-1-3p acts as a tumor suppressor via regulation of glutaminase expression in bladder cancer progression, and miR-1-3p might represent a novel therapeutic target for the treatment of bladder cancer.

Topics: 3' Untranslated Regions; Animals; Antagomirs; Cell Line, Tumor; Cell Movement; Cell Proliferation; CpG Islands; DNA Damage; DNA Methylation; Glutaminase; Histones; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; MicroRNAs; RNA Interference; RNA, Small Interfering; Urinary Bladder Neoplasms

Long non-coding ribonucleic acid urothelial carcinoma-associated 1 has been found to be a participant in cancer development and glucose metabolism in bladder cancer. However, the role of urothelial carcinoma-associated 1 in metabolic reprogramming in cancer remains to be clarified. In this study, we aim to elucidate the molecular mechanism underlying the regulation of glutamine metabolism by urothelial carcinoma-associated 1 in bladder cancer.. The RNA levels of urothelial carcinoma-associated 1, GLS2 and miR-16 in bladder tissues and cell lines were examined by real-time reverse transcriptase-polymerase chain reaction. The protein levels of GLS2 were detected by western blot analysis. Reactive oxygen species generation was examined by the fluorescein isothiocyanate mean value and fluorescence microscope. Glutamine consumption was analyzed using the glutamine assay kit. Additionally, we performed luciferase reporter assays to validate urothelial carcinoma-associated 1 sequence whether contains miR-16 binding site and the interaction between the 3'UTR sequence of GLS2 and mature miR-16.. Real-time reverse transcriptase-polymerase chain reaction demonstrated that the RNA level of urothelial carcinoma-associated 1 and GLS2 was positively correlated in bladder cancer tissues and cell lines. The expression of GLS2 mRNA and protein increased in cells which overexpression of urothelial carcinoma-associated 1 and decreased in cells which knocked-down of urothelial carcinoma-associated 1 cell lines. urothelial carcinoma-associated 1 reduced ROS production, and promoted mitochondrial glutaminolysis in human bladder cancer cells. Furthermore, luciferase reporter assays indicated that there was a miR-16 binding site in urothelial carcinoma-associated 1, and it showed appreciable levels of sponge effects on miR-16 as readouts in a dose-dependent manner. Moreover, the 'seed region' of miR-16 directly bound to the 3'UTR of GLS2 mRNA and regulated GLS2 expression level.. Together, our results revealed that urothelial carcinoma-associated 1 regulated the expression of GLS2 through interfering with miR-16, and repressed ROS formation in bladder cancer cells.

Topics: Carcinoma, Transitional Cell; Glutaminase; Glutamine; Humans; MicroRNAs; Reactive Oxygen Species; RNA, Long Noncoding; Urinary Bladder Neoplasms

L-Glutamine is a requirement for many cells in tissue culture, an intermediate in many metabolic pathways, and an alternative substrate to glucose for energy metabolism. These properties suggest that glutamine concentration might be a determinant of cell viability in tumours, especially in regions that are deficient in other metabolites. We have therefore studied the effects of glutamine depletion on single cells in culture, on spheroids and on experimental tumours. Absence of glutamine suppressed the growth rate of two cell lines, but cells cultured for up to 6 h in the absence of glutamine had no decrease in plating efficiency. There was little effect on growth of MGH-U1 (human bladder cancer) spheroids of varying the glutamine concentration in the range of 0.1 to 2 mM and spheroids exposed to these concentrations did not develop central necrosis. Lower concentration of glutamine suppressed the rate of spheroid growth, and spheroids did not grow in the absence of glutamine. Pseudomonas 7A glutaminase reduced the survival of cells in glutamine-free culture and prevented growth of spheroids. Glutaminase was injected into mice bearing experimental tumours to reduce blood levels of glutamine; some animals also received 15 Gy radiation to their tumours to assess the effects of glutamine levels on surviving nutrient-deprived (i.e. hypoxic) cells. Glutaminase had no effect on cell survival in the Lewis lung tumour or in MGH-U1 xenografts, with or without radiation; glutaminase caused dose-dependent growth delay of the KHT tumour, which was additive to that caused by radiation. The present results suggest that (i) short-term changes of glutamine concentration have small effects on cell viability; and (ii) depletion of glutamine levels in blood through the in vivo use of glutaminase is unlikely to produce major therapeutic effects against nutrient-deprived cells in solid tumours.

Topics: Animals; Cell Survival; Cells, Cultured; Fibrosarcoma; Glutaminase; Glutamine; Humans; Lung Neoplasms; Mice; Neoplasms, Experimental; Time Factors; Urinary Bladder Neoplasms