Bladder Cancer Tissue-Based Biomarkers

This review aims to provide a practical update regarding the current role of tissue-based biomarkers in bladder cancer. Their prognostic and predictive role both in non-muscle-invasive (NMIBC) and in muscle-invasive disease (MIBC) has been reviewed with particular focus to their use in clinical practice. In summary, the literature on the prediction of disease recurrence in NMIBC is inconclusive, and there is little information on prediction of response to intravesical bacillus Calmette-Guerin (BCG). Concerning disease progression, external prospective validation studies suggest that FGFR3 mutation status and gene signatures may improve models that are based only on clinicopathologic information. In MIBC, tissue-based biomarkers are increasingly important, since they may predict the response to systemic chemotherapy and immunotherapy. In particular, the advent of molecular characterization promises to revolutionize the paradigm of decision-making in the treatment of MIBC. Molecular subtyping has been shown to improve the prediction of pathological stage at RC and to predict the response to systemic chemotherapy and immunotherapy. However, external and prospective validations are warranted to confirm these preliminary findings. Several different tissue-based biomarkers such as PD-1/PD-L1 expression, tumor mutational burden, and the analysis of tumor microenvironment, may in future play a role in selecting patients for systemic immunotherapy. However, to date, no pretreatment recommendations can be definitively made on the basis of any molecular predictors. In conclusion, despite the potential of tissue-based biomarkers, their use in bladder cancer should be limited to experimental settings.

PIK3CA Is Regulated by CUX1, Promotes Cell Growth and Metastasis in Bladder Cancer via Activating Epithelial-Mesenchymal Transition

PIK3CA is a key component of phosphatidylinositol 3-kinase (PI3K) pathway that its involvement in tumorigenesis has been revealed by previous research. However, its functions and potential mechanisms in bladder cancer are still largely undiscovered. Tissue microarray (TMA) with 66 bladder cancer patients was surveyed via immunohistochemistry to evaluate the level of PIK3CA and CUX1 and we found upregulation of PIK3CA in bladder cancer tissue and patients with higher level of PIK3CA presented with poorer prognosis. Overly expressed PIK3CA promoted growth, migration, invasion, and metastasis of bladder cancer cells and knockdown of PIK3CA had the opposite effect. Gain-of-function and loss-of-function studies showed that PIK3CA expression was facilitated by CUX1, leading to activation of epithelial-mesenchymal transition (EMT), accompanied by upregulated expression of Snail, β-catenin, Vimentin and downregulated expression of E-cadherin in the bladder cancer cell lines. Besides, over-expressed CUX1 could restore the expression of downregulated Snail, β-catenin, Vimentin and E-cadherin which was induced by PIK3CA knockdown. These results revealed that PIK3CA overexpression in bladder cancer was regulated by the transcription factor CUX1, and PIK3CA exerted its biological effects by activating EMT.

Identification of Hyal2-expressing tumor-associated myeloid cells in cancer: implications for cancer-related inflammation through enhanced hyaluronan degradation

Increased presence of myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) in tumor tissue has been extensively reported. These cells represent a major constituent of tumor infiltrate and exhibit a distinct phenotype with immunosuppressive and tolerogenic functions. However, their role in the regulation of hyaluronan (HA) metabolism in the tumor microenvironment has not been established. Here we describe a novel function of tumor-associated myeloid cells related to the enhanced breakdown of extracellular HA in human bladder cancer tissue leading to accumulation of small HA fragments with MW <20 kDa. Increased fragmentation of extracellular HA and accumulation of low molecular weight HA (LMW-HA) in tumor tissue was associated with elevated production of multiple inflammatory cytokines, chemokines, and angiogenic factors. The fragmentation of HA by myeloid cells was mediated by the membrane-bound enzyme hyaluronidase 2 (Hyal2). The increased numbers of Hyal2+CD11b+ myeloid cells were detected in the tumor tissue as well as in the peripheral blood of bladder cancer patients. Co-expression of CD33 suggests that these cells belong to monocytic myeloid-derived suppressor cells. HA-degrading function of Hyal2-expressing MDSCs could be enhanced by exposure to tumor-conditioned medium, and IL-1β was identified as one of factors involved in the stimulation of Hyal2 activity. CD44-mediated signaling plays an important role in the regulation of HA-degrading activity of Hyal2-expressing myeloid cells, since engagement of CD44 receptor with specific monoclonal antibody triggered translocation of Hyal2 enzyme to the cellular surface and also stimulated secretion of IL-1β. Taken together, this work identifies the Hyal2-expressing tumor-associated myeloid cells, and links these cells to the accumulation of LMW-HA in the tumor microenvironment and cancer-related inflammation and angiogenesis.

Expression of MMP28 in bladder cancer tissue microarray and its clinical significance

Background: The aim of this study was to explore the expression pattern and prognostic value of MMP-28 for bladder cancer and analyze its relationship with the clinicopathological features of human bladder cancer. Methods: Immunohistochemical staining for MMP28 was performed in 491 archived radical bladder cancer resection and 80 normal specimens. The immunoreactivity of these proteins was correlated to evaluate their clinical significance as prognostic factors. Results: Protein level of MMP-28 was up-regulated in bladder cancer compared with adjacent non-tumor tissues. The increased expression of MMP-28 was significantly associated with high histological grade, lymph node metastasis, lymphatic invasion and distant metastasis (P<0.05). High expression of MMP-28 was also associated with greater risk of disease progression and decreased chance of cancer-specific survival. Further analysis suggested that MMP-28 was related with decreased overall survival. Conclusions: MMP-28 could be used as an effective marker for tumor diagnosis and predict tumor progression in bladder cancer. The expression patterns of MMP-28 interaction correlated well with the pathological stage, disease progression and tumor-specific survival. The finding may help identify more biologically aggressive carcinomas which could aid in patients who benefit from more intensive adjuvant therapy.