Systemic therapy for bladder cancer - a medical oncologist's perspective

Tannic Acid Impedes the Proliferation of Bladder Cancer Cells by Elevating Mitochondrial Pathways of Apoptosis

Bladder cancer stands as a prevailing neoplasm among men globally, distinguished for its pronounced malignancy attributed to invasiveness and metastatic proclivity. Tannic acid (TA), an organic compound in many plants, has garnered recent attention for its discernible anti-mutagenic attributes. This investigation endeavored to scrutinize the repercussions of TA on grade II bladder cancer, with a concerted focus on unraveling its anti-cancer mechanisms. The cytotoxic effects of TA on grade II bladder cancer cells were investigated using multiple techniques, including MTT assay, flow cytometry, TUNEL assay, and western blot. Our findings revealed that elevated concentrations of TA induced cytotoxic effects in grade II bladder cancer cells. Both flow cytometry and the TUNEL assay substantiated the dose-dependent capacity of TA to prompt apoptosis. Western blot analysis corroborated that TA treatment in bladder cancer cells resulted in the upregulation of cleaved caspase-3 expression and PARP. Furthermore, heightened TA dosage elicited an augmentation in the expression of pro-apoptotic proteins, namely Bax and Bak, alongside a reduction in the expression of the anti-apoptotic protein Bcl-2 within bladder cancer cells. This study confirms TA as a potential anticancer agent, demonstrably diminishing the viability of bladder cancer cells. TA exerts cytotoxicity through the activation of mitochondrial apoptotic pathways. Specifically, TA initiates the cleavage of PARP and caspase-3, concurrently augmenting the expression of pro-apoptotic proteins to facilitate apoptosis. Collectively, the present study indicates that TA effectively impedes the proliferation of bladder cancer cells by instigating apoptosis through the intrinsic mitochondrial pathway.

Nivolumab plus Gemcitabine-Cisplatin in Advanced Urothelial Carcinoma

BACKGROUND

No new agent has improved overall survival in patients with unresectable or metastatic urothelial carcinoma when added to first-line cisplatin-based chemotherapy.

METHODS

In this phase 3, multinational, open-label trial, we randomly assigned patients with previously untreated unresectable or metastatic urothelial carcinoma either to receive intravenous nivolumab (at a dose of 360 mg) plus gemcitabine-cisplatin (nivolumab combination) every 3 weeks for up to six cycles, followed by nivolumab (at a dose of 480 mg) every 4 weeks for a maximum of 2 years, or to receive gemcitabine-cisplatin alone every 3 weeks for up to six cycles. The primary outcomes were overall and progression-free survival. The objective response and safety were exploratory outcomes.

RESULTS

A total of 608 patients underwent randomization (304 to each group). At a median follow-up of 33.6 months, overall survival was longer with nivolumab-combination therapy than with gemcitabine-cisplatin alone (hazard ratio for death, 0.78; 95% confidence interval [CI], 0.63 to 0.96; P = 0.02); the median survival was 21.7 months (95% CI, 18.6 to 26.4) as compared with 18.9 months (95% CI, 14.7 to 22.4), respectively. Progression-free survival was also longer with nivolumab-combination therapy than with gemcitabine-cisplatin alone (hazard ratio for progression or death, 0.72; 95% CI, 0.59 to 0.88; P = 0.001). The median progression-free survival was 7.9 months and 7.6 months, respectively. At 12 months, progression-free survival was 34.2% and 21.8%, respectively. The overall objective response was 57.6% (complete response, 21.7%) with nivolumab-combination therapy and 43.1% (complete response, 11.8%) with gemcitabine-cisplatin alone. The median duration of complete response was 37.1 months with nivolumab-combination therapy and 13.2 months with gemcitabine-cisplatin alone. Grade 3 or higher adverse events occurred in 61.8% and 51.7% of the patients, respectively.

CONCLUSIONS

Combination therapy with nivolumab plus gemcitabine-cisplatin resulted in significantly better outcomes in patients with previously untreated advanced urothelial carcinoma than gemcitabine-cisplatin alone. (Funded by Bristol Myers Squibb and Ono Pharmaceutical; CheckMate 901 ClinicalTrials.gov number, NCT03036098.).

Compensatory combination of romidepsin with gemcitabine and cisplatin to effectively and safely control urothelial carcinoma

BACKGROUND

Human urothelial carcinoma (UC) has a high tendency to recur and progress to life-threatening advanced diseases. Advanced therapeutic regimens are needed to control UC development and recurrence.

METHODS

We pursued in vitro and in vivo studies to understand the ability of a triple combination of gemcitabine, romidepsin, and cisplatin (Gem+Rom+Cis) to modulate signalling pathways, cell death, drug resistance, and tumour development.

RESULTS

Our studies verified the ability of Gem+Rom+Cis to synergistically induce apoptotic cell death and reduce drug resistance in various UC cells. The ERK pathway and reactive oxygen species (ROS) played essential roles in mediating Gem+Rom+Cis-induced caspase activation, DNA oxidation and damage, glutathione reduction, and unfolded protein response. Gem+Rom+Cis preferentially induced death and reduced drug resistance in oncogenic H-Ras-expressing UC vs. counterpart cells that was associated with transcriptomic profiles related to ROS, cell death, and drug resistance. Our studies also verified the efficacy and safety of the Gem plus Rom+Cis regimen in controlling UC cell-derived xenograft tumour development and resistance.

CONCLUSIONS

More than 80% of UCs are associated with aberrant Ras-ERK pathway. Thus the compensatory combination of Rom with Gem and Cis should be seriously considered as an advanced regimen for treating advanced UCs, especially Ras-ERK-activated UCs.

Molecular Mechanisms of the Anti-Cancer Effects of Isothiocyanates from Cruciferous Vegetables in Bladder Cancer

Bladder cancer (BC) is a representative of urological cancer with a high recurrence and metastasis potential. Currently, cisplatin-based chemotherapy and immune checkpoint inhibitors are used as standard therapy in patients with advanced/metastatic BC. However, these therapies often show severe adverse events, and prolongation of survival is unsatisfactory. Therefore, a treatment strategy using natural compounds is of great interest. In this review, we focused on the anti-cancer effects of isothiocyanates (ITCs) derived from cruciferous vegetables, which are widely cultivated and consumed in many regions worldwide. Specifically, we discuss the anti-cancer effects of four ITC compounds—allyl isothiocyanate, benzyl isothiocyanate, sulforaphane, and phenethyl isothiocyanate—in BC; the molecular mechanisms underlying their anti-cancer effects; current trends and future direction of ITC-based treatment strategies; and the carcinogenic potential of ITCs. We also discuss the advantages and limitations of each ITC in BC treatment, furthering the consideration of ITCs in treatment strategies and for improving the prognosis of patients with BC.

Reversine induces autophagic cell death through the AMP-activated protein kinase pathway in urothelial carcinoma cells

Urothelial carcinoma is one of the most common malignancies of the urinary tract. Effective treatment of advanced urothelial carcinoma remains a clinical challenge with poor outcomes in these patients. Previous reports have shown that the expression of aurora kinase is associated with clinical stage and prognosis; hence, aurora kinases are potential targets in urothelial carcinoma therapy. Reversine, an aurora kinase inhibitor, was analyzed for its cytotoxicity in this study. Cell proliferation, flow cytometry, western blotting, and immunofluorescent assay were used to determine the effect of reversine on urothelial carcinoma cells. The results showed that reversine significantly inhibits the growth of urothelial carcinoma cell lines. Reversine induced cell cycle arrest at the G2/M phase, leading to autophagic cell death by activating the AMP-activated protein kinase pathway. Reversine induced significant cell death in urothelial carcinoma cells. Our results suggest that reversine may be a suitably small molecule for treating urothelial carcinoma in the future.

miRNA-556-3p promotes human bladder cancer proliferation, migration and invasion by negatively regulating DAB2IP expression

MicroRNAs (miRNAs) play critical roles in tumorigenesis and metastasis by negatively regulating gene expression through complementary binding to the 3'-untranslated region of target mRNAs. The role of miRNAs in expression of the tumor suppressor DAB2IP in bladder cancer (BC) remains unknown. The aim of the present study was to identify miRNAs targeting DAB2IP and determine their expression and function in BC. We predicted candidate miRNAs targeting DAB2IP using TargetScan software. Dual-luciferase reporter assays confirmed that miRNA-556-3p directly regulated DAB2IP expression. Quantitative RT-PCR and RNase protection assays showed that endogenous miRNA-556-3p expression was significantly upregulated in clinical samples of BC patients and BC cell lines and western blot analysis indicated that DAB2IP expression in BC tissues and BC cell lines was concurrently downregulated. Gain or loss of function studies showed that upregulation of miRNA-556-3p promoted proliferation, invasion, migration and colony formation of BC cells, whereas downregulation resulted in opposite effects. Importantly, restoration of DAB2IP expression rescued the effects induced by miRNA-556-3p. Overexpression of miRNA-556-3p in BC cells not only decreased DAB2IP expression, but also markedly increased Ras GTPase activity and ERK1/2 phosphorylation level. These findings suggest that DAB2IP is a direct target of miRNA-556-3p, and endogenous miRNA-556-3p expression shows inverse correlation with simultaneous DAB2IP expression in BC tissues and cells. miRNA-556-3p functions as a tumor promoter in tumorigenesis and metastasis of BC by targeting DAB2IP. Moreover, miRNA-556-3p-mediated DAB2IP suppression plays an oncogenic role by partial activation of the Ras-ERK pathway.

Ellagic Acid Inhibits Bladder Cancer Invasiveness and In Vivo Tumor Growth

Ellagic acid (EA) is a polyphenolic compound that can be found as a naturally occurring hydrolysis product of ellagitannins in pomegranates, berries, grapes, green tea and nuts. Previous studies have reported the antitumor properties of EA mainly using in vitro models. No data are available about EA influence on bladder cancer cell invasion of the extracellular matrix triggered by vascular endothelial growth factor-A (VEGF-A), an angiogenic factor associated with disease progression and recurrence, and tumor growth in vivo. In this study, we have investigated EA activity against four different human bladder cancer cell lines (i.e., T24, UM-UC-3, 5637 and HT-1376) by in vitro proliferation tests (measuring metabolic and foci forming activity), invasion and chemotactic assays in response to VEGF-A and in vivo preclinical models in nude mice. Results indicate that EA exerts anti-proliferative effects as a single agent and enhances the antitumor activity of mitomycin C, which is commonly used for the treatment of bladder cancer. EA also inhibits tumor invasion and chemotaxis, specifically induced by VEGF-A, and reduces VEGFR-2 expression. Moreover, EA down-regulates the expression of programmed cell death ligand 1 (PD-L1), an immune checkpoint involved in immune escape. EA in vitro activity was confirmed by the results of in vivo studies showing a significant reduction of the growth rate, infiltrative behavior and tumor-associated angiogenesis of human bladder cancer xenografts. In conclusion, these results suggest that EA may have a potential role as an adjunct therapy for bladder cancer.

Performance of simultaneous high temporal resolution quantitative perfusion imaging of bladder tumors and conventional multi-phase urography using a novel free-breathing continuously acquired radial compressed-sensing MRI sequence

PURPOSE

To investigate the feasibility of high temporal resolution quantitative perfusion imaging of bladder tumors performed simultaneously with conventional multi-phase MR urography (MRU) using a novel free-breathing continuously acquired radial MRI sequence with compressed-sensing reconstruction.

METHODS

22 patients with bladder lesions underwent MRU using GRASP (Golden-angle RAdial Sparse Parallel) acquisition. Multi-phase contrast-enhanced abdominopelvic GRASP was performed during free-breathing (1.4×1.4×3.0mm(3) voxel size; 3:44min acquisition). Two dynamic datasets were retrospectively reconstructed by combining different numbers of sequentially acquired spokes into each dynamic frame: 110 spokes per frame for 25-s temporal resolution (serving as conventional MRU for clinical interpretation) and 8 spokes per frame for 1.7-s resolution. Using 1.7-s resolution images, ROIs were placed within bladder lesions and normal bladder wall, a femoral artery arterial input function was generated, and the Generalized Kinetic Model was applied.

RESULTS

Biopsy/cystectomy demonstrated 16 bladder tumors (13 stage≥T2, 3 stage≤T1) and 6 benign lesions. All lesions were well visualized using 25-s clinical multi-phase images. Using 1.7-s resolution images, K(trans) was significantly higher in tumors (0.38±0.24) than normal bladder (0.12±0.02=8, p<0.001) or benign lesions (0.15±0.04, p=0.033). Ratio between K(trans) of lesions and normal bladder was nearly double for tumors than benign lesions (4.3±3.4 vs. 2.2±1.6), and K(trans) was nearly double in stage≥T2 than stage≤T1 tumors (0.44±0.24 vs. 0.24±0.24), although these did not approach significance (p=0.180-0.209), possibly related to small sample size.

CONCLUSION

GRASP allows simultaneous quantitative high temporal resolution perfusion of bladder lesions during clinical MRU examinations using only one contrast injection and without additional scan time.

MicroRNA-101 sensitizes hepatocellular carcinoma cells to doxorubicin-induced apoptosis via targeting Mcl-1

MicroRNAs (miRNAs/miRs) are important regulators of multiple cellular processes, and their dysregulation is a common event in tumorigenesis, including the development of hepatocellular carcinoma (HCC). Studies have shown that certain miRNAs are associated with resistance to chemotherapy or drug sensitization; however, the underlying mechanisms have largely remained elusive. Multiple drug resistance is a major barrier for the treatment of advanced HCC. In the present study, miR-101 was observed to be downregulated in a panel of HCC cell lines, suggesting that it has a tumor suppressor role. Furthermore, transfection of miR-101 significantly enhanced the cytotoxicity of doxorubicin to HepG2 cells. While overexpression of miR-101 did not influence the accumulation of doxorubicin, it promoted the apoptosis-inducing effect of doxorubicin in HepG2 cells. A bioinformatics analysis predicted that miR-101 directly targeted the 3'-untranslated region of myeloid cell leukemia 1 (Mcl-1), which was verified by a luciferase reporter assay. Finally, transfection of HepG2 cells with Mcl-1 expression plasmid inhibited apoptosis caused by doxorubicin plus miR-101 expression. In conclusion, the present study showed that miR-101 is a negative regulator of Mcl-1 in HCC, and the combination of miR-101 expression with doxorubicin may represent a novel approach for the treatment of HCC.

Comprehensive genomic profiling of 295 cases of clinically advanced urothelial carcinoma of the urinary bladder reveals a high frequency of clinically relevant genomic alterations

BACKGROUND

In the current study, the authors present a comprehensive genomic profile (CGP)-based study of advanced urothelial carcinoma (UC) designed to detect clinically relevant genomic alterations (CRGAs).

METHODS

DNA was extracted from 40 µm of formalin-fixed, paraffin-embedded sections from 295 consecutive cases of recurrent/metastatic UC. CGP was performed on hybridization-captured, adaptor ligation-based libraries to a mean coverage depth of 688X for all coding exons of 236 cancer-related genes plus 47 introns from 19 genes frequently rearranged in cancer, using process-matched normal control samples as a reference. CRGAs were defined as GAs linked to drugs on the market or currently under evaluation in mechanism-driven clinical trials.

RESULTS

All 295 patients assessed were classified with high-grade (International Society of Urological Pathology classification) and advanced stage (stage III/IV American Joint Committee on Cancer) disease, and 294 of 295 patients (99.7%) had at least 1 GA on CGP with a mean of 6.4 GAs per UC (61% substitutions/insertions/deletions, 37% copy number alterations, and 2% fusions). Furthermore, 275 patients (93%) had at least 1 CRGA involving 75 individual genes with a mean of 2.6 CRGAs per UC. The most common CRGAs involved cyclin-dependent kinase inhibitor 2A (CDKN2A) (34%), fibroblast growth factor receptor 3 (FGFR3) (21%), phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) (20%), and ERBB2 (17%). FGFR3 GAs were diverse types and included 10% fusions. ERBB2 GAs were equally divided between amplifications and substitutions. ERBB2 substitutions were predominantly within the extracellular domain and were highly enriched in patients with micropapillary UC (38% of 32 cases vs 5% of 263 nonmicropapillary UC cases; P<.0001).

CONCLUSIONS

Using a CGP assay capable of detecting all classes of GA simultaneously, an extraordinarily high frequency of CRGA was identified in a large series of patients with advanced UC. Cancer 2016;122:702-711. © 2015 American Cancer Society.

Comparative Gene Expression Analyses Identify Luminal and Basal Subtypes of Canine Invasive Urothelial Carcinoma That Mimic Patterns in Human Invasive Bladder Cancer

More than 160,000 people are expected to die from invasive urothelial carcinoma (iUC) this year worldwide. Research in relevant animal models is essential to improving iUC management. Naturally-occurring canine iUC closely resembles human iUC in histopathology, metastatic behavior, and treatment response, and could provide a relevant model for human iUC. The molecular characterization of canine iUC, however, has been limited. Work was conducted to compare gene expression array results between tissue samples from iUC and normal bladder in dogs, with comparison to similar expression array data from human iUC and normal bladder in the literature. Considerable similarities between enrichment patterns of genes in canine and human iUC were observed. These included patterns mirroring basal and luminal subtypes initially observed in human breast cancer and more recently noted in human iUC. Canine iUC samples also exhibited enrichment for genes involved in P53 pathways, as has been reported in human iUC. This is particularly relevant as drugs targeting these genes/pathways in other cancers could be repurposed to treat iUC, with dogs providing a model to optimize therapy. As part of the validation of the results and proof of principal for evaluating individualized targeted therapy, the overexpression of EGFR in canine bladder iUC was confirmed. The similarities in gene expression patterns between dogs and humans add considerably to the value of naturally-occurring canine iUC as a relevant and much needed animal model for human iUC. Furthermore, the finding of expression patterns that cross different pathologically-defined cancers could allow studies of dogs with iUC to help optimize cancer management across multiple cancer types. The work is also expected to lead to a better understanding of the biological importance of the gene expression patterns, and the potential application of the cross-species comparisons approach to other cancer types as well.

The human immunodeficiency virus protease inhibitor ritonavir is potentially active against urological malignancies

The human immunodeficiency virus protease inhibitor ritonavir has recently been shown to have antineoplastic activity, and its use in urological malignancies is under investigation with an eye toward drug repositioning. Ritonavir is thought to exert its antineoplastic activity by inhibiting multiple signaling pathways, including the Akt and nuclear factor-kappaB pathways. It can increase the amount of unfolded proteins in the cell by inhibiting both the proteasome and heat shock protein 90. Combinations of ritonavir with agents that increase the amount of unfolded proteins, such as proteasome inhibitors, histone deacetylase inhibitors, or heat shock protein 90 inhibitors, therefore, induce endoplasmic reticulum stress cooperatively and thereby kill cancer cells effectively. Ritonavir is also a potent cytochrome P450 3A4 and P-glycoprotein inhibitor, increasing the intracellular concentration of combined drugs by inhibiting their degradation and efflux from cancer cells and thereby enhancing their antineoplastic activity. Furthermore, riotnavir’s antineoplastic activity includes modulation of immune system activity. Therapies using ritonavir are thus an attractive new approach to cancer treatment and, due to their novel mechanisms of action, are expected to be effective against malignancies that are refractory to current treatment strategies. Further investigations using ritonavir are expected to find new uses for clinically available drugs in the treatment of urological malignancies as well as many other types of cancer.