The genetic landscapes of urological cancers and their clinical implications in the era of high-throughput genome analysis

Immunohistochemical markers as predictors of prognosis in multifocal prostate cancer

The impact of tumor focality on prostate cancer (PCa) prognosis has been addressed in several studies with conflicting results. Tumor foci from multifocal (MF) PCa can show highly heterogeneous molecular features. Our aim was to analyze the protein expression of PTEN, SPOP, SLC45A3, ETV1, ERG and the "triple hit" (ERG overexpression, PTEN plus SLC45A3 loss) in unifocal (UF) and MF PCa, to evaluate their value as prognostic markers according to focality, and the role of tumor heterogeneity in MF disease. PTEN, SPOP, SLC45A3, ETV1 and ERG immunohistochemical expression was evaluated in 185 PCa from 9 TMAs, 51 UF and 134 MF. In a subset of 69 MF cases, the dominant and secondary foci (DF and SF) were compared. Heterogeneity was considered when both tumor foci presented different expression patterns. Relationship with clinicopathological features was also analyzed. MF PCa was diagnosed in significantly younger patients when compared to UF ones (p = 0.007). ETV1 overexpression was associated with UF disease (p = 0.028). A shorter time to PSA recurrence was related to SLC45A3 wt expression in UF PCa (p = 0.052), and to SPOP expression loss (p = 0.043) or "triple hit" phenotype in MF PCa (p = 0.041). In MF cases, PTEN loss, SLC45A3 loss and "triple hit" phenotype were associated with the DF and had significant heterogeneity. In conclusion, our results indicate that UF and MF PCa have relevant and consistent molecular differences. The analysis of an immunohistochemical panel, composed by PTEN, SPOP, SLC45A3, ETV1 and ERG, could be useful to predict outcome in MF cases.

Stimulator of Interferon Genes Protein (STING) Expression in Cancer Cells: A Tissue Microarray Study Evaluating More than 18,000 Tumors from 139 Different Tumor Entities

Stimulator of interferon genes protein (STING) activates the immune response in inflammatory cells. STING expression in cancer cells is less well characterized, but STING agonists are currently being evaluated as anticancer drugs. A tissue microarray containing 18,001 samples from 139 different tumor types was analyzed for STING by immunohistochemistry. STING-positive tumor cells were found in 130 (93.5%) of 139 tumor entities. The highest STING positivity rates occurred in squamous cell carcinomas (up to 96%); malignant mesothelioma (88.5%-95.7%); adenocarcinoma of the pancreas (94.9%), lung (90.3%), cervix (90.0%), colorectum (75.2%), and gallbladder (68.8%); and serous high-grade ovarian cancer (86.0%). High STING expression was linked to adverse phenotypes in breast cancer, clear cell renal cell carcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, and papillary carcinoma of the thyroid (p < 0.05). In pTa urothelial carcinomas, STING expression was associated with low-grade carcinoma (p = 0.0002). Across all tumors, STING expression paralleled PD-L1 positivity of tumor and inflammatory cells (p < 0.0001 each) but was unrelated to the density of CD8+ lymphocytes. STING expression is variable across tumor types and may be related to aggressive tumor phenotype and PD-L1 positivity. The lack of relationship with tumor-infiltrating CD8+ lymphocytes argues against a significant IFN production by STING positive tumor cells.

Non-Invasive Diagnostics of Renal Cell Carcinoma Using Ultrasensitive Immunodetection of Cancer-Retina Antigens

Renal cell carcinoma (RCC) is the most common urological malignancy with a high mortality and low detection rate. One of the approaches to improving its diagnostics may be the search for new non-invasive biomarkers in liquid biopsy and development of more sensitive methods for their detection. Cancer-retina antigens, which are known to be aberrantly expressed in malignant tumors, are present in liquid biopsy at extremely low concentrations. Using the developed multiplex immunoassay with a detection limit of 0.1 pg/ml, urine and serum samples of 89 patients with RCC and 50 non-cancer patients were examined for the presence of cancer-retina antigens (arrestin, recoverin, rhodopsin kinase, and transducin); the difference between the RCC and control groups was evaluated with the χ² test. The results showed high diagnostic efficiency of a combination of arrestin and recoverin: at a threshold of 0.1 pg/ml, the sensitivity was 96%, specificity 92%, and AUC = 0.96 (95% confidence interval, 0.93-0.99). Seven days after nephrectomy, the concentration of the antigens returned to the level characteristic of the control group. Therefore, arrestin in a combination with recoverin can serve as a diagnostic non-invasive urinary biomarker of RCC.

The Emerging Role of Poly (ADP-Ribose) Polymerase Inhibitors as Effective Therapeutic Agents in Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the sixth most common cancer in the US. However, no significant changes in management have occurred since the tyrosine kinase era until the recent breakthrough with checkpoint inhibitors. Therefore, the need for more therapeutic options is paramount. Our objective was to determine whether PARP inhibition represents a novel therapeutic option for RCC. We used publicly available COSMIC, GDC Data Portal, and cBioPortal databases to explore mutations in DNA repair genes in RCC tissues from the TCGA cohort. We treated a human normal renal epithelial cell line RPTEC/TERT1 and two human renal cancer cell lines ACHN and CAKI-2 with PARPi niraparib, olaparib, rucaparib, veliparib, and talazoparib. Cell survival, cell proliferation, clonogenic ability, and apoptosis were assessed. RCC xenografts in SCID mice were treated with PARPi to evaluate their efficacy in vivo. Data mining revealed that ~27-32% of RCC tissues contain mutations in homologous recombination genes. Niraparib and talazoparib were the most effective at reducing cell survival, proliferation, and clonogenic ability in vitro. Niraparib, talazoparib, and rucaparib were the most effective in reducing RCC xenograft growth in vivo. Agents such as PARPi that exploit mutations in DNA damage repair genes may be effective therapeutic options for RCC.