Management of bladder cancer: current and emerging strategies

A surgical orthotopic approach for studying the invasive progression of human bladder cancer

The invasion of bladder cancer into the sub-urothelial muscle and vasculature are key determinants leading to lethal metastatic progression. However, the molecular basis is poorly understood, partly because of the lack of uncomplicated and reliable models that recapitulate the biology of locally invasive disease. We developed a surgical grafting technique, characterized by a simple, rapid, reproducible and high-efficiency approach, to recapitulate the pathobiological events of human bladder cancer invasion in mice. This technique consists of a small laparotomy and direct implantation of human cancer cells into the bladder lumen. Unlike other protocols, it does not require debriding of the urothelial lining, injection into the bladder wall, specialized imaging equipment, bladder catheterization or costly surgical equipment. With minimal practice, the procedure can be executed in <10 min. Tumors develop with a high take rate, and most cell lines exhibit local invasion within 4 weeks of implantation.

Latent Kaposi's sarcoma-associated herpesvirus infection in bladder cancer cells promotes drug resistance by reducing reactive oxygen species

Kaposi's sarcoma-associated herpesvirus (KSHV) is the major etiologic agent of Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. Recent studies have indicated that KSHV can be detected at high frequency in patient-derived bladder cancer tissue and might be associated with the pathogenesis of bladder cancer. Bladder cancer is the second most common cancer of the genitourinary tract, and it has a high rate of recurrence. Because drug resistance is closely related to chemotherapy failure and cancer recurrence, we investigated whether KSHV infection is associated with drug resistance of bladder cancer cells. Some KSHV-infected bladder cancer cell lines showed resistance to an anti-cancer drug, cisplatin, possibly as a result of down-regulation of reactive oxygen species. Additionally, drug resistance acquired from KSHV infection could partly be overcome by HDAC1 inhibitors. Taken together, the data suggest the possible role of KSHV in chemo-resistant bladder cancer, and indicate the therapeutic potential of HDAC1 inhibitors in drug-resistant bladder cancers associated with KSHV infection.

Caffeine Suppresses Apoptosis of Bladder Cancer RT4 Cells in Response to Ionizing Radiation by Inhibiting Ataxia Telangiectasia Mutated-Chk2-p53 Axis

Background:

Caffeine suppresses ataxia telangiectasia and Rad3 related and ataxia telangiectasia mutated (ATM) activities; ATM is the major kinase for DNA damage detection. This study aimed to investigate the effects of caffeine on DNA damage responses in cells from the bladder cancer cell line RT4 those were exposed to ionizing radiation (IR).

Methods:

Immunofluorescent staining was performed to investigate changes in the proteins involved in DNA damage responses with or without caffeine. A mouse xenograft model was used to study the effects of caffeine on the DNA damage responses. Western blotting was used to investigate the effects of caffeine pretreatment on the ATM-Chk2-p53-Puma axis, while real-time polymerase chain reaction (RT-PCR) assessed changes in messenger RNA levels of p53 and downstream targets responding to IR. Finally, terminal deoxynucleotidyl transferase-dUTP nick end labeling assay. Western blotting and colony formation assay were used to measure the effects of caffeine on radiation-related apoptosis. All of the data were analyzed with a two-tailed Student's t-test.

Results:

Immunofluorescent staining showed that caffeine pretreatment profoundly suppressed the formation of γH2AXand p53-binding protein 1 foci in RT4 cells in response to irradiation. Cellular and animal experiments suggested that this suppression was mediated by suppression of the ATM-Chk2-p53-Puma DNA damage-signaling axis. RT-PCR indicated caffeine also attenuated transactivation of p53 and p53-inducible genes. The colony formation assay revealed that caffeine displayed radioprotective effects on RT4 cells in response to low-dose radiation compared to the radiosensitization effects on T24 cells.

Conclusion:

Caffeine may inhibit IR-related apoptosis of bladder cancer RT4 cells by suppressing activation of the ATM-Chk2-p53-Puma axis.

Inhibitory role of the small leucine-rich proteoglycan biglycan in bladder cancer

BACKGROUND

Urothelial bladder cancer is the ninth most common cancer. Despite surgical and chemotherapeutic treatment the prognosis is still poor once bladder cancer progresses to a muscle-invasive state. Discovery of new diagnostic markers and pathophysiologic effectors might help to contribute to novel diagnostic and therapeutic options. The extracellular matrix microenvironment shaped by the extracellular matrix critically affects tumor cell and stroma cell functions. Therefore, aim of the present study was to assess the possible implication of the small leucine-rich proteoglycan biglycan in progression of human urothelial bladder cancer.

METHODS AND RESULTS

For this purpose tumor biopsies of 76 bladder cancer patients with different tumor stages (pTa, pT1-T4) were investigated with respect to biglycan expression and correlated with a long-term (10 years) clinical follow-up. Interestingly, higher biglycan mRNA expression was associated with higher tumor stages and muscle invasiveness. In vitro knock-down of endogenous biglycan in human urothelial carcinoma cells (J82 cells) increased proliferation, whereas addition of recombinant biglycan and overexpression of biglycan inhibited tumor cell proliferation. In line with this growth-inhibitory effect of biglycan, transplantation of J82 cells after knock-down of biglycan resulted in significantly increased growth of subcutaneous xenograft tumors in nude mice in vivo. Furthermore, treatment with two anti-proliferative, multi-receptor tyrosine kinase inhibitors-sunitinib and sorafenib-strongly upregulated biglycan expression. Collectively, the experimental data suggest that high biglycan expression is associated with reduced tumor cell proliferation. In accordance, Kaplan-Meier analysis revealed higher 10-year survival in patients with high biglycan mRNA expression in tumor biopsies.

CONCLUSION

In conclusion, the present data suggest that biglycan is an endogenous inhibitor of bladder cancer cell proliferation that is upregulated in response to anti-proliferative tyrosine kinase inhibitors. In addition, high biglycan expression is associated with favorable prognosis.

SEOM clinical guidelines for the treatment of invasive bladder cancer

The purpose of this article is to provide updated recommendations for the diagnosis and treatment of muscle- invasive and metastatic bladder cancer. The diagnosis of muscle-invasive bladder cancer is made by transurethral resection and following histopathologic evaluation. Invasive bladder cancer should be staged according to the UICC system. Patients with confirmed muscle-invasive bladder cancer should be staged by computed tomography scans of the chest, abdomen and pelvis. Radical cystectomy is the treatment of choice for both sexes and lymph node dissection should be an integral part of cystectomy. In muscle- invasive bladder cancer (cT2-4aN0M0) patients with good performance status (PS 0-1) and correct renal function, neoadjuvant chemotherapy should be recommended. Adjuvant chemotherapy is widely used in high-risk patients with pathologic stage T3 or T4 and/or positive nodes and within clinical trials. Multimodality bladder-preserving treatment in localised disease is currently regarded only as an alternative in selected, well informed and compliant patients for whom cystectomy is not considered for clinical or personal reasons. In metastatic disease, the first-line treatment for patients is cisplatin-containing combination chemotherapy. Recently, vinflunine has been approved in Europe for second-line treatment and is an option for second-line therapy in patients progressing to first-line platinum-based chemotherapy.

Transitional cell carcinoma of the bladder: racial and gender disparities in survival (1993 to 2002), stage and grade (1993 to 2007)

PURPOSE

Bladder cancer survival is consistently lower in female and black patients than in male and white patients. We compared trends and differences according to clinical, demographic and facility characteristics by patient race and gender to identify the impact of these characteristics on survival.

MATERIALS AND METHODS

We identified bladder transitional cell carcinoma cases diagnosed in 1993 to 2007 from the National Cancer Data Base. Trends in grade and stage distribution between 1993 and 2007 were analyzed. Survival differences by race and gender were compared using 5-year relative survival and multivariate Cox regression.

RESULTS

There were 310,257 white male, 102,345 white female, 13,313 black male and 7,439 black female patients. Black and female patients had a higher proportion of muscle invasive tumors than white and male patients, and black patients had a larger proportion of higher grade tumors. The incidence of stage 0a and of high grade tumors significantly increased with time. Multivariate analysis showed a significantly lower HR in white females than in white males (HR 0.9) but a significantly higher HR in black males and females (HR 1.2). The higher mortality risk in black males and females was primarily limited to late stage disease (HR 1.3).

CONCLUSIONS

Survival differences by race and gender are partially explained by differences in tumor and demographic characteristics in black males and females, and fully explained by these characteristics in white females. Treatment delays and under treatment due to comorbid conditions, age and other factors may also contribute to these disparities.