Clinical significance of subepithelial growth patterns in non-muscle invasive bladder cancer

Digital volumetric assessment of CIS and tumor mass compliments conventional histopathological assessment in muscle-invasive urothelial bladder cancer

Carcinoma in situ (CIS) of the bladder is a known parameter regarding the prognosis and recurrence tendency of urothelial carcinomas. Nevertheless, there is little evidence whether the amount of CIS or other precursor lesions, as well as the quantified tumor mass of muscle-invasive urothelial carcinoma, has an influence on the survival or recurrence rate of affected patients. From 80 patients with muscle invasive urothelial bladder cancer and radical cystectomy, 23 samples each were obtained as part of a whole organ mapping in a single institution study, in which the precursor lesions and tumor area were digitally measured and further correlated to pathological standard parameters, patient survival, molecular luminal and basal subtypes, and immune infiltration. Significant correlations were found between tumor mass and surface lining CIS amount for pT-stage, lymphovascular invasion, and perineural infiltration. Furthermore, an increased tumor mass as well as an increased amount of CIS combined with an increased tumor mass showed a significantly reduced survival rate in multivariable analysis (HR = 2.75; P = 0.019 vs. HR = 3.54; P = 0.002) as well as a significantly increased recurrence. No correlations could be found with molecular subtypes and immune infiltration. The exact measurement of the tumor mass with and without the CIS surface area, whether manually or, more specifically, digitally, could be incorporated into routine diagnostics and implemented as an independent predictor for patient post-surgical outcomes. It can therefore serve as an additional predictor for risk stratification and, if necessary, intensified follow-up care or therapy.

Mutational Landscape of Bladder Cancer in Mexican Patients: KMT2D Mutations and chr11q15.5 Amplifications Are Associated with Muscle Invasion

Bladder cancer (BC) is the most common neoplasm of the urinary tract, which originates in the epithelium that covers the inner surface of the bladder. The molecular BC profile has led to the development of different classifications of non-muscle invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). However, the genomic BC landscape profile of the Mexican population, including NMIBC and MIBC, is unknown. In this study, we aimed to identify somatic single nucleotide variants (SNVs) and copy number variations (CNVs) in Mexican patients with BC and their associations with clinical and pathological characteristics. We retrospectively evaluated 37 patients treated between 2012 and 2021 at the National Cancer Institute-Mexico (INCan). DNA samples were obtained from paraffin-embedded tumor tissues and exome sequenced. Strelka2 and Lancet packages were used to identify SNVs and insertions or deletions. FACETS was used to determine CNVs. We found a high frequency of mutations in TP53 and KMT2D, gains in 11q15.5 and 19p13.11-q12, and losses in 7q11.23. STAG2 mutations and 1q11.23 deletions were also associated with NMIBC and low histologic grade.

Disabled Homolog 2 (DAB2) Protein in Tumor Microenvironment Correlates with Aggressive Phenotype in Human Urothelial Carcinoma of the Bladder

Disabled homolog-2 (DAB2) has been reported to be a tumor suppressor gene. However, a number of contrary studies suggested that DAB2 promotes tumor invasion in urothelial carcinoma of the bladder (UCB). Here, we investigated the clinical role and biological function of DAB2 in human UCB. Immunohistochemical staining analysis for DAB2 was carried out on UCB tissue specimens. DAB2 expression levels were compared with clinicopathological factors. DAB2 was knocked-down by small interfering RNA (siRNA) transfection, and then its effects on cell proliferation, invasion, and migration, and changes to epithelial-mesenchymal transition (EMT)-related proteins were evaluated. In our in vivo assays, tumor-bearing athymic nude mice subcutaneously inoculated with human UCB cells (MGH-U-3 or UM-UC-3) were treated by DAB2-targeting siRNA. Higher expression of DAB2 was associated with higher clinical T category, high tumor grade, and poor oncological outcome. The knock-down of DAB2 decreased both invasion and migration ability and expression of EMT-related proteins. Significant inhibitory effects on tumor growth and invasion were observed in xenograft tumors of UM-UC-3 treated by DAB2-targeting siRNA. Our findings suggested that DAB2 expression was associated with poor prognosis through increased oncogenic properties including tumor proliferation, migration, invasion, and enhancement of EMT in human UCB.

Prognostic significance of tumor budding in muscle invasive urothelial carcinomas of the bladder

OBJECTIVE

The aim of this study was to evaluate the prognostic significance of tumor budding in muscle invasive urothelial carcinoma of bladder (MIBC).

MATERIAL AND METHODS

A total of 60 patients who underwent radical cystectomy and cystoprostatectomy for MIBC were included in the study. The correlations between tumor budding, and tumor necrosis, lymphovascular invasion (LVI), perineural invasion (PNI) and histopathological data with distant metastasis were evaluated. The correlation between progression free (PFS) and overall survival (OS) rates and the presence, and grade of tumor budding was investigated.

RESULTS

A statistically significant correlation was not seen between tumor budding, necrosis, LVI, and PNI. There was a strong correlation between distant organ metastasis, and presence of tumor necrosis. There was no statistically significant correlation between PFS, OS and tumor budding. A statistically significant relationship was observed between OS and tumor stage, lymph node metastasis, and distant organ metastasis.

CONCLUSION

In our study, statistically significant effect of tumor budding on survival rates in MIBCs was not observed. Also, no significant correlation was observed between tumor budding and tumor necrosis, LVI, and PNI.

Collagen type IV alpha 1 (COL4A1) and collagen type XIII alpha 1 (COL13A1) produced in cancer cells promote tumor budding at the invasion front in human urothelial carcinoma of the bladder

Current knowledge of the molecular mechanism driving tumor budding is limited. Here, we focused on elucidating the detailed mechanism underlying tumor budding in urothelial cancer of the bladder. Invasive urothelial cancer was pathologically classified into three groups as follows: nodular, trabecular, and infiltrative (tumor budding). Pathohistological analysis of the orthotopic tumor model revealed that human urothelial cancer cell lines MGH-U3, UM-UC-14, and UM-UC-3 displayed typical nodular, trabecular, and infiltrative patterns, respectively. Based on the results of comprehensive gene expression analysis using microarray (25 K Human Oligo chip), we identified two collagens, COL4A1 and COL13A1, which may contribute to the formation of the infiltrative pattern. Visualization of protein interaction networks revealed that proteins associated with connective tissue disorders, epithelial-mesenchymal transition, growth hormone, and estrogen were pivotal factors in tumor cells. To evaluate the invasion pattern of tumor cells in vitro, 3-D collective cell invasion assay using Matrigel was performed. Invadopodial formation was evaluated using Gelatin Invadopodia Assay. Knockdown of collagens with siRNA led to dramatic changes in invasion patterns and a decrease in invasion capability through decreased invadopodia. The in vivo orthotopic experimental model of bladder tumors showed that intravesical treatment with siRNA targeting COL4A1 and COL13A1 inhibited the formation of the infiltrative pattern. COL4A1 and COL13A1 production by cancer cells plays a pivotal role in tumor invasion through the induction of tumor budding. Blocking of these collagens may be an attractive therapeutic approach for treatment of human urothelial cancer of the bladder.

The prognostic role of lymphovascular invasion in urothelial carcinoma of the bladder

Outcome prediction in patients with bladder cancer has improved through the development of nomograms and predictive models. However, integration of further characteristics such as lymphovascular invasion (LVI) might increase the accuracy and clinical utility of these instruments. Assessment and reporting of LVI in specimens from transurethral resection of the bladder tumour (TURBT) or biopsy in patients with non-muscle-invasive bladder cancer (NMIBC) or muscle-invasive bladder cancer (MIBC) might enable improved staging, prognostication and clinical decision-making. In NMIBC, presence of LVI in TURBT and biopsy samples seems to be associated with understaging and increased risks of disease recurrence and progression. In MIBC, presence of LVI is associated with features of aggressive disease and predicts recurrence and survival. Integration of LVI status into predictive models might aid clinical decision-making regarding intravesical instillation schedules and regimens, early radical cystectomy in patients with high-grade T1 disease and perioperative chemotherapy. However, LVI assessment is hampered by insufficient reproducibility and reliability, lack of routine evaluation and limited concordance between findings in TURBT and radical cystectomy specimens. Standardization of the pathological criteria defining LVI is warranted to improve its reporting in routine clinical practice and its utility as a care-changing prognostic marker.

Exploration of risk factors predicting outcomes for primary T1 high-grade bladder cancer and validation of the Spanish Urological Club for Oncological Treatment scoring model: Long-term follow-up experience at a single institute

OBJECTIVE

To determine the prognostic factors of primary T1 high-grade bladder cancer and to validate the Spanish Urological Club for Oncological Treatment model in Japanese patients with T1 high-grade bladder cancer treated at a single institution.

METHODS

Records of 106 patients with T1 high-grade bladder cancer treated from 1998 to 2013 were retrospectively reviewed. Variables included various clinicopathological parameters, including lymphovascular invasion and tumor growth pattern at the invasion front. Recurrence-free survival and progression-free survival were analyzed. Multivariate Cox proportional regression analysis was used to verify the prognostic significance of the variables. Scores for recurrence and progression were calculated using the Spanish Urological Club for Oncological Treatment model.

RESULTS

Of 106 patients, 44 (42%) had recurrence and 16 (15%) developed progression after a median (interquartile range) follow-up period of 54 months (range 32-81 months). Non-papillary shape was the only independent predictor for recurrence, while broad-based tumor stalk and infiltrative tumor growth pattern at the invasion front were determined to be independent predictors for progression. Stratification of patients according to the number of progression risk factors yielded hazard ratios of 10.1 and 13.1 in patients having one and two risks, respectively, compared with those without any risks. The Spanish Urological Club for Oncological Treatment model successfully stratified our patients with a trend toward different probabilities of recurrence and progression.

CONCLUSIONS

The results of the present study might be helpful for counseling certain patients towards intensive treatment, such as radical cystectomy and/or platinum-based systemic chemotherapy. In addition, the Spanish Urological Club for Oncological Treatment model might be applicable to Japanese patients with T1 high-grade bladder cancer.

Thimerosal-induced apoptosis in mouse C2C12 myoblast cells occurs through suppression of the PI3K/Akt/survivin pathway

Background

Thimerosal, a mercury-containing preservative, is one of the most widely used preservatives and found in a variety of biological products. Concerns over its possible toxicity have reemerged recently due to its use in vaccines. Thimerosal has also been reported to be markedly cytotoxic to neural tissue. However, little is known regarding thimerosal-induced toxicity in muscle tissue. Therefore, we investigated the cytotoxic effect of thimerosal and its possible mechanisms on mouse C2C12 myoblast cells.

Methodology/Principal Findings

The study showed that C2C12 myoblast cells underwent inhibition of proliferation and apoptosis after exposure to thimerosal (125–500 nM) for 24, 48 and 72 h. Thimerosal caused S phase arrest and induced apoptosis as assessed by flow cytometric analysis, Hoechst staining and immunoblotting. The data revealed that thimerosal could trigger the leakage of cytochrome c from mitochondria, followed by cleavage of caspase-9 and caspase-3, and that an inhibitor of caspase could suppress thimerosal-induced apoptosis. Thimerosal inhibited the phosphorylation of Akt^ser473 and survivin expression. Wortmannin, a PI3K inhibitor, inhibited Akt activity and decreased survivin expression, resulting in increased thimerosal-induced apoptosis in C2C12 cells, while the activation of PI3K/Akt pathway by mIGF-I (50 ng/ml) increased the expression of survivin and attenuated apoptosis. Furthermore, the inhibition of survivin expression by siRNA enhanced thimerosal-induced cell apoptosis, while overexpression of survivin prevented thimerosal-induced apoptosis. Taken together, the data show that the PI3K/Akt/survivin pathway plays an important role in the thimerosal-induced apoptosis in C2C12 cells.

Conclusions/Significance

Our results suggest that in C2C12 myoblast cells, thimerosal induces S phase arrest and finally causes apoptosis via inhibition of PI3K/Akt/survivin signaling followed by activation of the mitochondrial apoptotic pathway.