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Abstract Advances in bladder cancer (BCa) treatment have been hampered by the lack of predictive biomarkers and targeted therapies. Here, we demonstrate that loss of the tumor suppressor NUMB promotes aggressive bladder tumorigenesis and worsens disease outcomes. Retrospective cohort studies show that NUMB-loss correlates with poor prognosis in post-cystectomy muscle-invasive BCa patients and increased risk of muscle invasion progression in non-muscle invasive BCa patients. In mouse models, targeted Numb ablation induces spontaneous tumorigenesis and sensitizes the urothelium to carcinogenic insults, accelerating tumor onset and progression. Integrative transcriptomic and functional analyses in mouse and human BCa models reveal that upregulation of YAP transcriptional activity via a RHOA/ROCK-dependent pathway is a hallmark of NUMB-deficient BCa. Pharmacological or genetic inhibition of this molecular pathway selectively inhibits proliferation and invasion of NUMB-deficient BCa cells in 3D-Matrigel organoids. Thus, NUMB-loss could serve as a biomarker for identifying high-risk patients who may benefit from targeted anti-RHOA/ROCK/YAP therapies.

Finding biomarkers for targeted therapy is a promising approach to treat cancer. Here, the authors show that in breast cancer preclinical models and patients, CDK12 promotes tumourigenesis but induces selective vulnerability to therapies that target folate one-carbon metabolism.

The biological players involved in angiogenesis are only partially defined. Here, we report that endothelial cells (ECs) express a novel isoform of the cell-surface adhesion molecule L1CAM, termed L1-ΔTM. The splicing factor NOVA2, which binds directly to L1CAM pre-mRNA, is necessary and sufficient for the skipping of L1CAM transmembrane domain in ECs, leading to the release of soluble L1-ΔTM. The latter exerts high angiogenic function through both autocrine and paracrine activities. Mechanistically, L1-ΔTM-induced angiogenesis requires fibroblast growth factor receptor-1 signaling, implying a crosstalk between the two molecules. NOVA2 and L1-ΔTM are overexpressed in the vasculature of ovarian cancer, where L1-ΔTM levels correlate with tumor vascularization, supporting the involvement of NOVA2-mediated L1-ΔTM production in tumor angiogenesis. Finally, high NOVA2 expression is associated with poor outcome in ovarian cancer patients. Our results point to L1-ΔTM as a novel, EC-derived angiogenic factor which may represent a target for innovative antiangiogenic therapies., Competing Interests: EB, MG, MC, FF, PP, ML, CB, DP, AD, CG, GJ, CL, GB, SF, MM, MI, CG, RG, DN, DG No competing interests declared, JM, JS Affiliated with Gene Tools, LLC. Funding bodies had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript. ED Reviewing editor, eLife, CG Consultant for Gene-Tools, LLC. Funding bodies had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript., (© 2019, Angiolini et al.)

HMGA protein overexpression is associated with a highly malignant phenotype and it is also causally related to neoplastic cell transformation. Our previous results have shown that HMGA1 was not expressed in normal breast tissue whereas HMGA1 staining was intense in 25% of hyperplastic lesions with cellular atypia and in 60% of sporadic ductal carcinomas. Moreover, HMGA1 protein levels were significantly correlated with c-Erb-B2 expression. These results suggested HMGA1 expression as a novel prognostic factor in breast ductal carcinomas. In order to investigate whether the HMGA1 detection might have a prognostic role also for inherited breast carcinomas we have analysed the expression of the HMGA1 proteins in 116 breast familial carcinomas associated with BRCA1 or BRCA2 or negative for mutations in both genes (BRCAX). HMGA1 expression was weakly positive in 23 (20%), moderately positive in 34 (29%) and strongly positive in 20 (17%) breast carcinomas, and was not detected in 39 of them (34%). Statistical analysis of the immunostaining data showed that HMGA1 was significantly overexpressed, with a more intense staining, in BRCA2 (p=0.0009) and BRCAX (p=0.0134) patients compared to BRCA1 ones. Furthermore, in BRCA2 positive patients, the expression of HMGA1 seems to correlate with a favourable prognosis with a median overall survival of 65 months and a 5-year survival rate of 80% for HMGA1-negative patients, while median overall survival in the HMGA1-positive subsets was not reached with 5-year survival rates ranging from 84% to 100% of patients (p=0.0198). Conversely, no correlation was found between HMGA1 expression and overall survival in patients carrying inherited mutations in the BRCA1 and in BRCAX patients., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Protein ubiquitination is critical for many cellular processes, through its ability to regulate protein degradation and various signaling mechanisms. In the ubiquitin (Ub) system, substrate specificity is achieved through the E3 family of Ub ligases. Because alterations of the ubiquitination machinery have been reported in human cancers, the selective interference with Ub ligases might represent a powerful therapeutic tool. Here, we report the first wide survey of misregulation of Ub ligases in cancer. We analysed 82 Ub ligases in nine types of cancer by in situ hybridization on tissue microarrays. We found 27 instances in which an Ub ligase was altered in a given type of tumor, when compared with normal tissues: 21 cases of overexpression and 6 cases of underexpression. We further analysed selected Ub ligases in large cohorts of breast and non-small-cell lung carcinomas. In five, of six, of these extended analyses (HUWE1, CCNB1IP1, SIAH1 and SIAH2 in breast cancer and CCNB1IP1 in lung cancer), we found that the levels of Ub ligases correlated significantly with relevant prognostic factors, and with clinical outcome. Our findings show that the alteration of Ub ligases is a frequent event in cancer and identify candidate targets for molecular therapies.