Julieta Afonso

The aggressiveness of urothelial carcinoma depends to a large extent on lymphovascular invasion – the prognostic contribution of related molecular markers

Aims:  Bladder cancer is the second most common malignancy of the urogenital region. The majority of bladder cancer deaths occur as a consequence of metastatic disease. Blood vessel density (BVD), a surrogate marker for angiogenesis, has been shown to be predictive of progression and poor prognosis, as well as lymphatic vessel density (LVD). The aim of this study was to evaluate, in human urothelial bladder cancer (UBC), the clinical and prognostic significance of angiogenesis, lymphangiogenesis and lymphovascular invasion, assessed with the use of specific immunohistochemical markers.

CD147 and MCT1-potential partners in bladder cancer aggressiveness and cisplatin resistance

The relapsing and progressive nature of bladder tumors, and the heterogeneity in the response to cisplatin‐containing regimens, are the major concerns in the care of urothelial bladder carcinoma (UBC) patients. The metabolic adaptations that alter the tumor microenvironment and thus contribute to chemoresistance have been poorly explored in UBC setting. We found significant associations between the immunoexpressions of the microenvironment‐related molecules CD147, monocarboxylate transporters (MCTs) 1 and 4, CD44 and CAIX in tumor tissue sections from 114 UBC patients. The presence of MCT1 and/or MCT4 expressions was significantly associated with unfavorable clinicopathological parameters. The incidence of CD147 positive staining significantly increased with advancing stage, grade and type of lesion, and occurrence of lymphovascular invasion. Similar associations were observed when considering the concurrent expression of CD147 and MCT1. This expression profile lowered significantly the 5‐year disease‐free and overall survival rates. Moreover, when selecting patients who received platinum‐based chemotherapy, the prognosis was significantly worse for those with MCT1 and CD147 positive tumors. CD147 specific silencing by small interfering RNAs (siRNAs) in UBC cells was accompanied by a decrease in MCT1 and MCT4 expressions and, importantly, an increase in chemosensitivity to cisplatin. Our results provide novel insights for the involvement of CD147 and MCTs in bladder cancer progression and resistance to cisplatin‐based chemotherapy. We consider that the possible cooperative role of CD147 and MCT1 in determining cisplatin resistance should be further explored as a potential theranostics biomarker.

Phospho-mTOR in non-tumour and tumour bladder urothelium: Pattern of expression and impact on urothelial bladder cancer patients

Urothelial bladder carcinoma (UBC) is heterogeneous in its pathology and clinical behaviour. Evaluation of prognostic and predictive biomarkers is necessary, in order to produce personalised treatment options. The present study used immunohistochemistry to evaluate UBC sections containing tumour and non-tumour areas from 76 patients, for the detection of p-mTOR, CD31 and D2-40 (blood and lymphatic vessels identification, respectively). Of the non-tumour and tumour sections, 36 and 20% were scored positive for p-mTOR expression, respectively. Immunoexpression was observed in umbrella cells from non-tumour urothelium, in all cell layers from non-muscle-invasive (NMI) tumours (including expression in superficial cells), and in spots of cells from muscle-invasive (MI) tumours. Positive expression decreased from non-tumour to tumour urothelium, and from pT1/pTis to pT3/pT4 tumours; however, the few pT3/pT4 positive cases had worse survival rates, with 5-year disease-free survival being significantly lower. Angiogenesis occurrence was impaired in pT3/pT4 tumours that did not express p-mTOR. In conclusion, p-mTOR expression in non-tumour umbrella cells is likely a reflection of their metabolic plasticity, and extension to the inner layers of the urothelium in NMI tumours is consistent with an enhanced malignant potential. The expression in cell spots in a few MI tumours and absence of expression in the remaining tumours is intriguing and requires further research. Additional studies regarding the up- and downstream effectors of the mTOR pathway should be conducted.

Metabolic coupling in urothelial bladder cancer compartments and its correlation to tumor aggressiveness

abstract Monocarboxylate transporters (MCTs) are vital for intracellular pH homeostasis by extruding lactate from highly glycolytic cells. These molecules are key players of the metabolic reprogramming of cancer cells, and evidence indicates a potential contribution in urothelial bladder cancer (UBC) aggressiveness and chemoresistance. However, the specific role of MCTs in the metabolic compartmentalization within bladder tumors, namely their preponderance on the tumor stroma, remains to be elucidated. Thus, we evaluated the immunoexpression of MCTs in the different compartments of UBC tissue samples (n = 111), assessing the correlations among them and with the clinical and prognostic parameters. A significant decrease in positivity for MCT1 and MCT4 occurred from normoxic toward hypoxic regions. Significant associations were found between the expression of MCT4 in hypoxic tumor cells and in the tumor stroma. MCT1 staining in normoxic tumor areas, and MCT4 staining in hypoxic regions, in the tumor stroma and in the blood vessels were significantly associated with UBC aggressiveness. MCT4 concomitant positivity in hypoxic tumor cells and in the tumor stroma, as well as positivity in each of these regions concomitant with MCT1 positivity in normoxic tumor cells, was significantly associated with an unfavourable clinicopathological profile, and predicted lower overall survival rates among patients receiving platinum-based chemotherapy. Our results point to the existence of a multi-compartment metabolic model in UBC, providing evidence of a metabolic coupling between catabolic stromal and cancer cells’ compartments, and the anabolic cancer cells. It is urgent to further explore the involvement of this metabolic coupling in UBC progression and chemoresistance.

Angiogenesis, Lymphangiogenesis and Lymphovascular Invasion: Prognostic Impact for Bladder Cancer Patients

Bladder cancer is the second most common tumor of the urogenital tract. Urothelial carcinoma is the most frequent histologic type, being unique among epithelial carcinomas in its divergent pathways of tumorigenesis. Surgery continues to have a predominant role in the management of urothelial bladder cancer (Kaufman et al., 2009). However, the debate about the best treatment approach for T1G3 and muscle invasive tumors continually challenges all urologic surgeons and oncologists. This debate involves several aspects. First, a significant number of T1G3 tumors recurs and progresses rapidly after transurethral resection and BCG treatment (Wiesner et al., 2005). Second, half of patients with invasive tumors have a dismal outcome despite an effective treatment by radical cystectomy (Sternberg et al., 2007). Third, the extension of lymphadenectomy remains an issue of controversy, although clinical evidence suggests that an extended lymph node dissection may not only provide prognostic information, but also a significant therapeutic benefit for both lymph node-positive and lymph node-negative patients undergoing radical cystectomy (May et al., 2011). In muscle invasive bladder cancer, the presence of tumor foci in lymph nodes is an early event in progression, and the lymphatic vessels within or in the proximity to the primary tumor serve as the primary conduits for tumor dissemination (Youssef et al., 2011). Fourth, although urothelial bladder cancer is a chemo-sensitive tumor (Kaufman et al., 2000; von der Maase et al., 2000), adjuvant systemic chemotherapy does not reveal benefits (Walz et al., 2008), and neoadjuvant chemotherapy is not yet accepted as the best approach in invasive bladder cancer (Clark, 2009). Therefore, in order to solve the aforementioned problems, it is crucial to improve the knowledge about tumor microenvironment, regulation of cancer metabolism and neovascularization.