UBE2C-induced crosstalk between mono- and polyubiquitination of SNAT2 promotes lymphatic metastasis in bladder cancer.

Ubiquitination plays an essential role in protein stability, subcellular localization, and interactions. Crosstalk between different types of ubiquitination results in distinct biological outcomes for proteins. However, the role of ubiquitination-related crosstalk in lymph node (LN) metastasis and the key regulatory factors controlling this process have not been determined. Using high-throughput sequencing, we found that ubiquitin-conjugating enzyme E2 C (UBE2C) was overexpressed in bladder cancer (BCa) and was strongly associated with an unfavorable prognosis. Overexpression of UBE2C increased BCa lymphangiogenesis and promoted LN metastasis both in vitro and in vivo. Mechanistically, UBE2C mediated sodium-coupled neutral amino acid transporter 2 (SNAT2) monoubiquitination at lysine 59 to inhibit K63-linked polyubiquitination at lysine 33 of SNAT2. Crosstalk between monoubiquitination and K63-linked polyubiquitination increased SNAT2 membrane protein levels by suppressing epsin 1-mediated (EPN1-mediated) endocytosis. SNAT2 facilitated glutamine uptake and metabolism to promote VEGFC secretion, ultimately leading to lymphangiogenesis and LN metastasis in patients with BCa. Importantly, inhibition of UBE2C significantly attenuated BCa lymphangiogenesis in a patient-derived xenograft model. Our results reveal the mechanism by which UBE2C mediates crosstalk between the monoubiquitination and K63-linked polyubiquitination of SNAT2 to promote BCa metastasis and identify UBE2C as a promising target for treating LN-metastatic BCa.

Inflammatory myofibroblastic tumor in the urinary bladder in a dog.

An 8-year-old castrated male Maltese dog was presented with a urinary bladder mass, urolithiasis, and hematuria. A solitary, pedunculated, intraluminal mass on the caudodorsal wall was identified with extensive irregular bladder wall thickening, and the mass was surgically removed. Postoperative histopathology demonstrated a submucosal lesion comprising spindle cells with marked inflammatory cell infiltration, without malignant changes. Immunohistochemical staining revealed vimentin and desmin positivity in the mass. An inflammatory myofibroblastic tumor (IMT) was definitively diagnosed. No recurrence was observed during a 43-month follow-up period. Although IMTs are rare in dogs, they should be considered a differential diagnosis for mass-like urinary bladder lesions accompanying a chronic inflammatory disease process. Key clinical message: Canine IMT should be included in the differential diagnoses of bladder masses, especially when dogs exhibit chronic irritation and inflammation.

Tumeur myofibroblastique inflammatoire de la vessie chez un chienUn chien maltais mâle castré de 8 ans a été présenté avec une masse à la vessie, une lithiase urinaire et une hématurie. Une masse intraluminale pédonculée solitaire sur la paroi caudodorsale a été identifiée avec un épaississement important et irrégulier de la paroi vésicale, et la masse a été retirée chirurgicalement. L'histopathologie postopératoire a mis en évidence une lésion à la sous-muqueuse comprenant des cellules fusiformes avec une infiltration cellulaire inflammatoire marquée, sans modification maligne. La coloration immunohistochimique a révélé une positivité à la vimentine et à la desmine dans la masse. Une tumeur myofibroblastique inflammatoire (IMT) a été définitivement diagnostiquée. Aucune récidive n'a été observée au cours d'une période de suivi de 43 mois. Bien que les IMT soient rares chez le chien, ils doivent être considérés comme un diagnostic différentiel des lésions de la vessie de type masse accompagnant un processus de maladie inflammatoire chronique.Message clinique clé:L'IMT canine doit être incluse dans les diagnostics différentiels des masses vésicales, en particulier lorsque les chiens présentent une irritation et une inflammation chroniques.(Traduit par Dr Serge Messier).

Investigation of risk factors for vaginal dehiscence and development of small bowel evisceration after robot-assisted radical cystectomy for female bladder cancer and an improved vaginal reconstruction technique to prevent its onset.

Transvaginal organ prolapse, such as small bowel evisceration, is a rare complication after radical cystectomy (RC) in female patients with invasive bladder cancer, However, it often requires emergency surgical repair. Here, we describe our experience with such a case and a review of similar previously reported cases, along with evaluation of the risk factors. We also propose a vaginal reconstruction technique to prevent this complication during robot-assisted laparoscopic radical cystectomy (RARC). A total of 178 patients who underwent laparoscopic radical cystectomy (LRC) or RARC were enrolled, 34 of whom (19%) were female. One of the 34 female patients had transvaginal small bowel evisceration after RARC. We evaluated our case and six such previously reported cases, to determine vaginal reconstruction techniques during RARC to prevent this complication postoperatively. Median age of these cases was 73 (51-80) years, and all patients were postmenopausal. The median time to small bowel evisceration was 14 (6-120) weeks postoperatively. In addition, we changed the methods of the vaginal reconstruction technique during RARC from the conventional side-to-side closure technique to the improved caudal-to-cephalad closure technique. Since implementing this change, we have not experienced any cases of vaginal vault dehiscence or organ prolapse. Transvaginal small bowel evisceration after RC can easily become severe. Therefore, all possible preventive measures should be taken during RARC. We believe that our vaginal reconstruction techniques might reduce the risk of developing this complication.

Arterio-ureteral fistula from a pseudoaneurysm of the right common iliac artery after robot-assisted laparoscopic radical cystectomy: A case report.

Arterio-ureteral fistulas (AUFs), which are relatively rare but potentially life-threatening, require prompt diagnosis and treatment. We reported a case of AUFs following robot-assisted laparoscopic radical cystectomy (RARC) with extended pelvic lymph node dissection and ileal conduit urinary diversion for muscle-invasive bladder cancer, which resulted in massive hemorrhage. Urine leaked from the anastomosis between the ureter, and the end of the ileal conduit was infected, which resulted in an AUF between the pseudoaneurysm of the right common iliac artery and the ureter. The AUF was managed successfully by vascular intervention with an arterial stent graft.

[A Case of Primary Adenocarcinoma Mucinous Subtype of the Bladder].

A 48-year-old man who presented with asymptomatic gross hematuria in July 202X had been followed up without treatment. In January 202X, he was referred to our department due to the exacerbation of his hematuria. Contrast-enhanced magnetic resonance imaging revealed bladder cancer suggested bilateral seminal vesicle and prostate invasion, and enlarged right internal and external iliac lymph nodes. The pathological diagnosis was mucinous bladder adenocarcinoma. Prostate biopsy results were negative. Upper and lower gastrointestinal examinations were unremarkable. We suspected bladder cancer cT4aN2M0. In March 202X＋1, the patient underwent robotic-assisted laparoscopic total bladder resection, pelvic lymph node dissection, and intracorporeal urinary tract modification (ileal conduit creation). The final diagnosis was primary mucinous adenocarcinoma pT4aN2M0 of the bladder. Given the heightened risk of recurrence, the patient was administered a three-month course of oxaliplatin and capecitabine (XELOX) as adjuvant postoperative chemotherapy. The patient remains free of progression at 8 months postoperatively. Adenocarcinoma of the bladder is an exceedingly rare entity, with no established chemotherapeutic protocols. Primary mucinous adenocarcinoma of the bladder is even more exceptional. Presently, only regimens similar to those for colorectal cancer or adenocarcinoma of unknown primary, including 5-fluorouracil, are considered. In our particular case, we elected to pursue XELOX therapy, aligning with the principles governing the management of colorectal cancer.

[A Case of Successful Treatment of Small Cell Carcinoma of the Bladder with Pembrolizumab].

Small cell carcinoma of the bladder (SCCB) is a rare cancer that accounts for approximately 1% of primary malignant bladder tumors. It is highly malignant and has a poor prognosis. Similar to small cell lung cancer, platinum-based chemotherapy is recommended as the first-line therapy, and amrubicin (AMR) is recommended as the second-line therapy, but there is no established therapy after the second line. We report a case of SCCB that was refractory to multiple chemotherapies but responded to pembrolizumab. A 77-year-old male, diagnosed with clinical stage T3N0M0 small cell carcinoma and invasive urothelial carcinoma by transurethral resection of bladder tumor (TURBT), underwent robot-assisted radical cystectomy after three cycles of neoadjuvant cisplatin-irinotecan chemotherapy, and pathological examination revealed only small cell carcinoma in his cystectomy specimen. After three courses of adjuvant carboplatin-etoposide chemotherapy, the patient developed liver and bone metastases. Furthermore, after two courses of amrubicin, we started pembrolizumab due to the progression of metastases. Metastases decreased after starting pembrolizumab and continued to decrease after discontinuation because of immunerelated adverse events (irAEs). Therefore, pembrolizumab may be an option for the treatment of refractory SCCB.

[Two Cases of Bleeding from the Ileal Conduit Due to Ectopic Varices].

Case 1 : A 75-year-old man was emergently admitted to our hospital with a complaint of continuous bleeding from the ileal conduit. The conduit was constructed by a total pelvic resection for sigmoid colon cancer that invaded the urinary bladder 24 years ago. Swollen cutaneous mucosa was seen around the ileal conduit, but no obvious bleeding spot was observed. The contrast-enhanced computed tomographic (CT) scan and 3D visualization revealed varices extending to the abdominal wall. Percutaneous transhepatic embolization successfully stopped the bleeding, but it was needed again after two years. Case 2 : A 72-yearold man with a history of open cystectomy and ileal conduit for bladder cancer came to our hospital two years after the surgery, complaining of continuous bleeding from the conduit. The skin around the stoma site was discolored purple, but no obvious bleeding site or bloody urine was observed. The CT scan similar to Case 1 revealed varices in the ileal conduit, and percutaneous transhepatic embolization successfully stopped the bleeding, but it was needed again after five months. After that, three months passed without recurrence.

[A Case of Lymphorrhea after Radical Cystectomy Treated by Ultrasound-Guided Inguinal Intranodal Lymphangiography].

A 76-year-old woman was diagnosed with invasive bladder cancer and underwent cystectomy, bilateral external iliac, internal iliac and obturator lymph node dissection, and bilateral cutaneous ureterostomy. Pathological findings showed no lymph node metastasis ; however, the patient had lower abdominal pain and fever from the 14th postoperative day, and computed tomography (CT) revealed fluid retention in the pelvis. Retrograde pyelography showed no leakage from the urinary tract, and a drain was placed after percutaneous puncture of the pelvic cavity. There was copious drainage fluid and its nature and composition suggested lymphorrhea. Ultrasound-guided intranodal lymphangiography revealed contrast material leakage from the bilateral lymph node dissection sites. After lymphangiography, drainage from the drain decreased. Despite the drainage being minimal yet persistent, sclerotherapy was performed, the drain was removed and the patient was discharged. After discharge, there was leakage from the site of urethral extraction, and CT revealed recurrent lymph leakage. The patient was readmitted, and a second lymphangiography was performed. The leakage from the site of urethral extraction gradually decreased, and the patient was discharged on the 59th postoperative day. CT after discharge confirmed that the lymphorrhea had shrunk in size, and there has been no recurrence since then. Lymphangiography is a promising treatment option for lymphorrhea after pelvic surgery.

[Repair of Vaginal Cuff Dehiscence after Laparoscopic Radical Cystectomy with Gracilis Myocutaneous Flap].

Vaginal cuff dehiscence after total hysterectomy or total cystectomy had been increasing since laparoscopic or robotic surgery became a common surgery among gynecologists and urologists. A 52-yearold woman underwent laparoscopic radical total cystectomy for muscle invasive bladder carcinoma at Rakuwakai Otowa Hospital. She was emergently admitted with a fist-sized lump protruding from her vagina four months after surgery. Physical examination and her past history on admission disclosed vaginal cuff dehiscence after cystectomy. Computed tomographic scan and magnetic resonance imaging showed no bowel evisceration in the lump. We confirmed that the content of lump was peritoneal tissue and removed it by laparoscopic surgery. Simultaneously, we repaired the vaginal cuff dehiscence with a gracilis myocutaneous flap. There was no subsequent recurrence of vaginal dehiscence or bladder carcinoma in one-year follow-up.

Urinary microbiome dysbiosis is associated with an inflammatory environment and perturbed fatty acids metabolism in the pathogenesis of bladder cancer.

BACKGROUND: Bladder cancer is a common malignancy with high recurrence rate. Early diagnosis and recurrence surveillance are pivotal to patients' outcomes, which require novel minimal-invasive diagnostic tools. The urinary microbiome is associated with bladder cancer and can be used as biomarkers, but the underlying mechanism is to be fully illustrated and diagnostic performance to be improved. METHODS: A total of 23 treatment-naïve bladder cancer patients and 9 non-cancerous subjects were enrolled into the Before group and Control group. After surgery, 10 patients from the Before group were further assigned into After group. Void mid-stream urine samples were collected and sent for 16S rDNA sequencing, targeted metabolomic profiling, and flow cytometry. Next, correlations were analyzed between microbiota, metabolites, and cytokines. Finally, receiver operating characteristic (ROC) curves of the urinary biomarkers were plotted and compared. RESULTS: Comparing to the Control group, levels of IL-6 (p < 0.01), IL-8 (p < 0.05), and IL-10 (p < 0.05) were remarkably elevated in the Before group. The α diversity of urine microbiome was also significantly higher, with the feature microbiota positively correlated to the level of IL-6 (r = 0.58, p < 0.01). Significant differences in metabolic composition were also observed between the Before and Control groups, with fatty acids and fatty acylcarnitines enriched in the Before group. After tumor resection, cytokine levels and the overall microbiome structure in the After group remained similar to that of the Before group, but fatty acylcarnitines were significantly reduced (p < 0.05). Pathway enrichment analysis revealed beta-oxidation of fatty acids was significantly involved (p < 0.001). ROC curves showed that the biomarker panel of Actinomycetaceae + arachidonic acid + IL-6 had superior diagnostic performance, with sensitivity of 0.94 and specificity of 1.00. CONCLUSIONS: Microbiome dysbiosis, proinflammatory environment and altered fatty acids metabolism are involved in the pathogenesis of bladder cancer, which may throw light on novel noninvasive diagnostic tool development.

Construction and validation of a prognostic model for bladder cancer based on disulfidptosis-related lncRNAs.

BACKGROUND: Bladder cancer (BLCA) is a prevalent and aggressive cancer associated with high mortality and poor prognosis. Currently, studies on the role of disulfidptosis-related long non-coding RNAs (DRLs) in BLCA are limited. This study aims to construct a prognostic model based on DRLs to improve the accuracy of survival predictions for patients and identify novel targets for therapeutic intervention in BLCA management. METHODS: Transcriptomic and clinical datasets for patients with BLCA were obtained from The Cancer Genome Atlas. Using multivariate Cox regression and least absolute shrinkage and selection operator techniques, a risk prognostic signature defined by DRLs was developed. The model's accuracy and prognostic relevance were assessed through Kaplan-Meier survival plots, receiver operating characteristic curves, concordance index, and principal component analysis. Functional and pathway enrichment analyses, including Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis, were conducted to elucidate the underlying biological processes. Immune cell infiltration was quantified using the CIBERSORT algorithm. Differences and functions of immune cells in different risk groups were evaluated through single-sample Gene Set Enrichment Analysis. The Tumor Immune Dysfunction and Exclusion predictor and tumor mutational burden (TMB) assessments were utilized to gauge the likelihood of response to immunotherapy. Drug sensitivity predictions were made using the Genomics of Drug Sensitivity in Cancer database. RESULTS: A robust 8-DRL risk prognostic model, comprising LINC00513, SMARCA5-AS1, MIR4435-2HG, MIR4713HG, AL122035.1, AL359762.3, AC006160.1, and AL590428.1, was identified as an independent prognostic indicator. This model demonstrated strong predictive power for overall survival in patients with BLCA, revealing significant disparities between high- and low-risk groups regarding tumor microenvironment, immune infiltration, immune functions, TMB, Tumor Immune Dysfunction and Exclusion scores, and drug susceptibility. CONCLUSION: This study introduces an innovative prognostic signature of 8 DRLs, offering a valuable prognostic tool and potential therapeutic targets for bladder carcinoma. The findings have significant implications for TMB, the immune landscape, and patient responsiveness to immunotherapy and targeted treatments.

Robotic assisted vs open radical cystectomy: an updated systematic review and meta-analysis.

Several randomized control trials (RCTs) have been published comparing open (ORC) with robot-assisted radical cystectomy (RARC). However, uncertainty persists regarding this issue, as evidences and recommendations on RARC are still lacking. In this systematic review and metaanalysis, we summarized evidence in this context. A literature search was conducted according to PRISMA criteria, using PubMed/Medline, Web Of Science and Embase, up to March 2024. Only randomized controlled trials (RCTs) were selected. The primary endpoint was to investigate health-related quality of life (QoL) both at 3 and 6 months after surgery. Secondary endpoints include pathological and perioperative outcomes, postoperative complications and oncological outcomes. Furthermore, we conducted a cost evaluation based on the available evidence. Eight RCTs were included, encompassing 1024 patients (515 RARC versus 509 ORC). QoL appeared similar among the two groups both after 3 and 6 months. No significant differences in overall and major complications at 30 days (p = 0.11 and p > 0.9, respectively) and 90 days (p = 0.28 and p = 0.57, respectively) were observed, as well as in oncological, pathological and perioperative outcomes, excepting from operative time, which was longer in RARC (MD 92.34 min, 95% CI 83.83-100.84, p < 0.001) and transfusion rate, which was lower in RARC (OR 0.43, 95% CI 0.30-0.61, p < 0.001). Both ORC and RARC are viable options for bladder cancer, having comparable complication rates and oncological outcomes. RARC provides transfusion rate advantages, however, it has longer operative time and higher costs. QoL outcomes appear similar between the two groups, both after 3 and 6 months.

Gut microbiota Parabacteroides distasonis enchances the efficacy of immunotherapy for bladder cancer by activating anti-tumor immune responses.

OBJECTIVE: Bladder cancer(BCa) was a disease that seriously affects patients' quality of life and prognosis. To address this issue, many researches suggested that the gut microbiota modulated tumor response to treatment; however, this had not been well-characterized in bladder cancer. In this study, our objective was to determine whether the diversity and composition of the gut microbiota or the density of specific bacterial genera influence the prognosis of patients with bladder cancer. METHODS: We collected fecal samples from a total of 50 bladder cancer patients and 22 matched non-cancer individuals for 16S rDNA sequencing to investigate the distribution of Parabacteroides in these two groups. Further we conducted follow-up with cancer patients to access the impact of different genera of microorganisms on patients survival. We conducted a Fecal Microbiota Transplantation (FMT) and mono-colonization experiment with Parabacteroides distasonis to explore its potential enhancement of the efficacy of anti-PD-1 immunotherapy in MB49 tumor-bearing mice. Immunohistochemistry, transcriptomics and molecular experiment analyses were employed to uncover the underlying mechanisms. RESULTS: The 16S rDNA showed that abundance of the genus Parabacteroides was elevated in the non-cancer control group compared to bladder cancer group. The results of tumor growth curves showed that a combination therapy of P. distasonis and ICIs treatment significantly delayed tumor growth and increased the intratumoral densities of both CD4+T and CD8+T cells. The results of transcriptome analysis demonstrated that the pathways associated with antitumoral immune response were remarkably upregulated in the P. distasonis gavage group. CONCLUSION: P. distasonis delivery combined with α-PD-1 mAb could be a new strategy to enhance the effect of anti-PD-1 immunotherapy. This effect might be achieved by activating immune and antitumor related pathways.

Concomitant decrease of E- and A-FABP expression predicts worse survival in urothelial bladder cancer patients.

Non-muscle invasive bladder cancers (NMIBC) pTa-pT1 are depicted by a high risk of recurrence and/or progression with an unpredictable clinical evolution. Our aim was to identify, from the original resection specimen, tumors that will progress to better manage patients. We previously showed that A-FABP (Adipocyte- Fatty Acid Binding Protein) loss predicted NMIBC progression. Here we determined by immunohistochemistry the prognostic value of E-FABP (Epidermal-Fatty Acid Binding Protein) expression in 210 tumors (80 pTa, 75 pT1, 55 pT2-T4). Thus, E-FABP low expression was correlated with a high grade/stage, the presence of metastatic lymph nodes, and visceral metastases (p < 0.001). Unlike A-FABP in NMIBC, E-FABP low expression was not associated with RFS or PFS in Kaplan-Meier analysis. But patients of the overall cohort with a high E-FABP expression had a longer mOS (53.8 months vs. 29.3 months, p = 0.029). The immunohistochemical analysis on the same NMIBC tissue sections revealed that when A-FABP is absent, a high E-FABP expression is detected. E-FABP could compensate A-FABP loss. Interestingly, patients, whose original tumor presents both low E-FABP and negative A-FABP, had the worse survival, those maintaining the expression of both markers had better survival. To conclude, the combined evaluation of A- and E-FABP expression allowed to stratify patients with urothelial carcinoma for optimizing treatment and follow-up.

Nuclear translocation of ISG15 regulated by PPP2R2B inhibits cisplatin resistance of bladder cancer.

Cisplatin resistance is a major challenge for systemic therapy against advanced bladder cancer (BC). Little information is available on the regulation of cisplatin resistance and the underlying mechanisms require elucidation. Here, we detected that downregulation of the tumor suppressor, PPP2R2B (a serine/threonine protein phosphatase 2 A regulatory subunit), in BC promoted cell proliferation and migration. What's more, low PPP2R2B expression was correlated with cisplatin resistance. In vitro and in vivo experiments verified that PPP2R2B could promote BC sensitivity to cisplatin. In terms of mechanism, we identified a novel function of PPP2R2B as a nucleocytoplasmic transport molecule. PPP2R2B promoted ISG15 entry into the nucleus by mediating binding of IPO5 with ISG15. Nuclear translocation of ISG15 inhibited DNA repair, further increasing ISG15 expression through activation of the STING pathway. Besides, PPP2R2B was down-regulated by SUV39H1-mediated histone 3 lysine 9 trimethylation, which could be restored by the SUV39H1-specific inhibitor, chaetocin. Our data suggest that PPP2R2B expression level is a potential biomarker for chemotherapy response and that chemotherapy in combination with chaetocin may be a feasible treatment strategy for patients with BC.

A histopathological and epidemiological study of urothelial carcinoma at a tertiary care centre in Peshawar, Pakistan.

Bladder cancer is the ninth leading cause of death worldwide and 14th leading cause of death in Pakistan. The objective of this study was to determine the frequency of urothelial carcinoma in various age groups, its gender distribution, and grades. A total of 131 cases of urothelial carcinoma, received at Department of Pathology, Peshawar Medical College, Peshawar, between January 2017 to December 2022, were included in the study; of them 107 (81.6%) were males while 24 (18.3%) were females with a mean age of 62±13 years. The most common histological subtype was papillary urothelial carcinoma in 117(89.3%) cases, followed by Squamous and Glandular in 5(3.8%) cases. Majority of the urothelial carcinoma with high grade showed a statistically significant relation with muscle invasion 38 (50.66%). Males were four times more likely to have urothelial carcinoma while older age groups were more likely to have high grade urothelial carcinoma.

[A Case of Systemic Wild-Type Transthyretin Amyloid (ATTR) Amyloidosis Diagnosed in a Patient with Gross Hematuria].

An 85-year-old woman visited our hospital with a complaint of asymptomatic gross hematuria. Cystoscopy showed a non-papillary sessile tumor about 3 cm in size. Magnetic resonance imaging (MRI) suggested invasion of surrounding fat tissue. Thoracoabdominal contrast-enhanced computed tomography (CT) showed no tumor of the upper urinary tract or metastasis. We diagnosed the tumor as bladder cancer cT3N0M0 and performed transurethral bladder tumor resection 22 days after her first visit. No tumor was found at the time of surgery. We resected a reddened area to include a muscle layer and performed random biopsy. Hematoxylin and eosin stain showed eosinophilic tuberous tissue that stained with Congo red around blood vessels in the subepithelial stroma and the muscle layer. There was no dysplasia in the bladder epithelium. Therefore, we diagnosed the case as bladder amyloidosis. Immunostaining of the amyloid subtype revealed transthyretin amyloid (ATTR) amyloidosis. Bence-Jones protein in urine was negative, M protein was not detected in serum protein electrophoresis, and serum amyloid A was at the threshold. Scintigraphy for 99m Tc pyrophosphoric acid was positive in the myocardium. No genetic disorder was detected. We concluded that it was systemic ATTRwt amyloidosis as above. The patient did not wish to be treated for the systemic amyloidosis. Thirteen months after surgery, the patient showed no signs of recurrence in the bladder. As cardiac function is a prognostic factor in systemic amyloidosis, we need to consider the possibility of systemic amyloidosis when diagnosing bladder amyloidosis.

Impairment of α-tubulin and F-actin interactions of GJB3 induces aneuploidy in urothelial cells and promotes bladder cancer cell invasion.

BACKGROUND: We have previously identified an unsuspected role for GJB3 showing that the deficiency of this connexin protein induces aneuploidy in human and murine cells and accelerates cell transformation as well as tumor formation in xenograft models. The molecular mechanisms by which loss of GJB3 leads to aneuploidy and cancer initiation and progression remain unsolved. METHODS: GJB3 expression levels were determined by RT-qPCR and Western blot. The consequences of GJB3 knockdown on genome instability were assessed by metaphase chromosome counting, multinucleation of cells, by micronuclei formation and by the determination of spindle orientation. Interactions of GJB3 with α-tubulin and F-actin was analyzed by immunoprecipitation and immunocytochemistry. Consequences of GJB3 deficiency on microtubule and actin dynamics were measured by live cell imaging and fluorescence recovery after photobleaching experiments, respectively. Immunohistochemistry was used to determine GJB3 levels on human and murine bladder cancer tissue sections. Bladder cancer in mice was chemically induced by BBN-treatment. RESULTS: We find that GJB3 is highly expressed in the ureter and bladder epithelium, but it is downregulated in invasive bladder cancer cell lines and during tumor progression in both human and mouse bladder cancer. Downregulation of GJB3 expression leads to aneuploidy and genomic instability in karyotypically stable urothelial cells and experimental modulation of GJB3 levels alters the migration and invasive capacity of bladder cancer cell lines. Importantly, GJB3 interacts both with α-tubulin and F-actin. The impairment of these interactions alters the dynamics of these cytoskeletal components and leads to defective spindle orientation. CONCLUSION: We conclude that deregulated microtubule and actin dynamics have an impact on proper chromosome separation and tumor cell invasion and migration. Consequently, these observations indicate a possible role for GJB3 in the onset and spreading of bladder cancer and demonstrate a molecular link between enhanced aneuploidy and invasive capacity cancer cells during tumor cell dissemination.

Dose-response relationship between arsenic in drinking water and mortality of urinary cancers in Taiwan.

Ingested arsenic is carcinogenic to the human urinary tract, but uncertainties remain regarding the dose-response relationship. To assess dose-response relationships between arsenic ingestion and urinary cancers, we evaluated the associations between the arsenic level in drinking water and mortality of cancers of the bladder, kidney, and prostate in Taiwan. We utilized the 1971-2000 Taiwan death registry data and calculated the age-standardized mortality rates (ASMRs) using the 1976 world standard population as the reference group. We used the data from a 1974-1976 census survey of wells on the arsenic levels in drinking water conducted by the government to assess exposure levels, which had been divided into three categories: below 0.05 ppm, 0.05-0.35 ppm, and above 0.35 ppm. The data were analyzed using multiple linear regression models and geographical information system. We found no increase in ASMR for all, or any, of the urinary cancers at exposure levels of 0.05-0.35 ppm arsenic, but at exposure levels > 0.35 ppm arsenic was associated with increased ASMR in both males and females for bladder cancer, kidney cancer, and all urinary cancers combined. There was no increased ASMR associated with prostate cancer observed for either exposure category.