Bladder cancer is one of the most common cancers worldwide, with transitional cell carcinoma (TCC) being the predominant form. Here we report a genomic analysis of TCC by both whole-genome and whole-exome sequencing of 99 individuals with TCC. Beyond confirming recurrent mutations in genes previously identified as being mutated in TCC, we identified additional altered genes and pathways that were implicated in TCC. Notably, we discovered frequent alterations in STAG2 and ESPL1, two genes involved in the sister chromatid cohesion and segregation (SCCS) process. Furthermore, we also detected a recurrent fusion involving FGFR3 and TACC3, another component of SCCS, by transcriptome sequencing of 42 DNA-sequenced tumors. Overall, 32 of the 99 tumors (32%) harbored genetic alterations in the SCCS process. Our analysis provides evidence that genetic alterations affecting the SCCS process may be involved in bladder tumorigenesis and identifies a new therapeutic possibility for bladder cancer.

Long Noncoding RNAs (lncRNAs) are a kind of non-protein coding transcripts longer than 200 nucleotides, and play important roles in diverse biological processes, such as embryonic development and apoptosis. Homeobox (HOX) transcript antisense intergenic RNA (HOTAIR) is a negative prognostic factor in a variety of human cancers, such as breast, liver and lung cancers. HOTAIR can promote cancer cell metastasis by reprogramming chromatin organization. In the present study, HOTAIR expression was elevated in tissues of renal cell carcinoma compared to adjacent normal tissues, and positively correlated with metastasis (P<0.05). The cell migration was inhibited in scratch test and transwell assay after HOTAIR knockdown (P<0.05). Further researches revealed that histone demethylase JMJD3 was reduced and its target gene Snai1 expression was down-regulated after HOTAIR suppression (P<0.05). Meanwhile, the level of histone methytransferase EZH2 target gene PCDHB5 was increased (P<0.05). Collectively, these data suggest that HOTAIR is an important promoter in metastasis of renal cell carcinoma and also plays a dual regulatory role in chromatin state by effecting both histone metylation and demethylation at different gene loci.

Objectives Recent advances in patient‐derived cancer organoids have opened a new avenue for personalised medicine. We aimed to establish an in vitro technological platform to evaluate chimeric antigen receptor (CAR)‐T cell‐mediated cytotoxicity against bladder cancer. Methods Patient‐derived bladder cancer organoids (BCOs) were derived using classic medium containing R‐spondin 1 and noggin. The features of BCOs were characterised via H&E, whole‐exome sequencing and immunofluorescence of specific markers. Surface antigen expression profiles of the recently identified CAR‐recognisable targets were determined with a panel of antibodies via immunohistochemistry. A co‐cultivation system consisting of BCOs and engineered T cells targeting a specific antigen was utilised to test its efficacy to model immunotherapy by cytotoxic assays and ELISA. Results Bladder cancer organoid lines of basal and luminal subtypes were established. The histopathological morphology, genomic alteration, and specific marker expression profiles showed that the BCO lines retained the characteristics of the original tumors. Among all tested CAR‐recognisable antigens in other solid tumors, MUC1 was simultaneously expressed in organoids and parental tumor tissues. Given the surface antigen profiles, second‐generation CAR‐T cells targeting MUC1 were prepared for modelling in vitro immunotherapy responses in BCOs. Specific immune cytotoxicity occurred only in the MUC1+ organoids but not in the MUC1‐ organoids or control CAR‐T cells. Conclusion Patient‐derived BCOs recapitulate the heterogeneity and key features of parental cancer tissues, and these BCOs could be useful for preclinical testing of CAR‐T cells in vitro.

Bladder cancer is one of the most common urinary cancers worldwide. Emerging studies indicated that long non-coding RNAs (lncRNAs) play crucial roles in cancer biology. In this study, we found that a novel lncRNA Zinc finger E-box-binding homeebox1 (ZEB1) antisense RNA (ZEB1-AS1) was overexpressed in bladder cancer tissues compared to paired noncancerous tissues. Moreover, the expression of ZEB1-AS1 was positive correlated with higher histological grade and TNM stage in bladder cancer. Furthermore, Loss-of-function experiments showed that down-regulation of ZEB1-AS1 not only can suppress cell growth but also can inhibit migration and induce apoptosis in bladder cancer cell lines 5637 and SW780. In conclusion, these findings indicated that ZEB1-AS1 plays regulatory roles in bladder cancer and it may become a novel molecular biomarker of prognosis and therapy in bladder cancer.

Opa interacting protein 5 (OIP5) has previously been identified as a tumorigenesis gene. The purpose of this study is to explore the role of OIP5 in the progression of bladder cancer (BC). The OIP5 expression and clinical behaviors in bladder cancer were collected from lager database. Our study showed that OIP5 was highly expressed in bladder cancer tissues and cells. Overexpression of OIP5 in tumor patients predicted worse overall survival (OS) and higher histological grade. Vitro and vivo experiments demonstrated that knockdown of OIP5 significantly inhibited cell growth of BC. Scratch assay and transwell assay suggested that migration capacity of BC cells was decreased after knockdown of OIP5. Cisplatin sensitivity assay indicated that depletion of OIP5 increased the sensitivity of BC cells to cisplatin. Finally, we identified 38 overlapping differentially expressed genes (DEGs) between RNA-seq and TCGA analyses which were closely linked to OIP5. Bioinformatics analysis showed that these DEGs enriched in oocyte meiosis, fanconi anemia pathway, cell cycle, and microRNAs regulation. TOP2A, SPAG5, SKA1, EXO1, TK1 were confirmed to associated with bladder cancer development. Our study suggests that OIP5 may be a potential biomarker for growth, metastasis and drug-resistance in bladder cancer.