SUMMARY Multiple angiogenesis inhibitors have been therapeutically validated in preclinical cancer models, and several in clinical trials. Here we report that angiogenesis inhibitors targeting the VEGF pathway demonstrate antitumor effects in mouse models of pancreatic neuroendocrine carcinoma and glioblastoma but concomitantly elicit tumor adaptation and progression to stages of greater malignancy, with heightened invasiveness and in some cases increased lymphatic and distant metastasis. Increased invasiveness is also seen by genetic ablation of the Vegf-A gene in both models, substantiating the results of the pharmacological inhibitors. The realization that potent angiogenesis inhibition can alter the natural history of tumors by increasing invasion and metastasis warrants clinical investigation, as the prospect has important implications for the development of enduring antiangiogenic therapies.

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The landscape of cancer treatment has dramatically changed over the last four decades. The age when surgery and radiotherapy were the only effective way to fight tumour growth has ended. A complex scenario where the molecular features of tumours seem to be the cornerstone of any therapy is now emerging. Here we provide an overview on the different approaches to cancer treatment. This review will help the reader to acknowledge the pivotal role of some classic cancer therapies, including surgery, radiation, chemotherapy and endocrine therapy, now better understood in the mechanims underpinning their efficacy. Following, we focus on the understanding of the value of systemic treatment and on an up-date on the novel, up-coming therapies of the current targeted therapy age, including new antibodies, small molecules, antiangiogenics and viral therapy. We briefly elaborate, finally, on new biomarkers development and how it should rule and determine the future of therapeutic research in cancer.

Paracrine signaling through receptor activator of NF-kB (RANK) pathway mediates the expansion of mammary epithelia that occurs during pregnancy, and activation of RANK pathway promotes mammary tumorigenesis in mice. In this study we extend these previous data to human cells and show that the RANK pathway promotes the development of mammary stem cells and breast cancer. Overexpression of RANK (FL-RANK) in a panel of tumoral and normal human mammary cells induces the expression of breast cancer stem and basal/stem cell markers. High levels of RANK in untransformed MCF10A cells induce changes associated with both stemness and transformation, including mammary gland reconstitution, epithelial-mesenchymal transition (EMT), increased migration, and anchorage-independent growth. In addition, spheroids of RANK overexpressing MCF10A cells display disrupted acinar formation, impair growth arrest and polarization, and luminal filling. RANK overexpression in tumor cells with nonfunctional BRCA1 enhances invasiveness in acinar cultures and increases tumorigenesis and metastasis in immunodeficient mice. High levels of RANK were found in human primary breast adenocarcinomas that lack expression of the hormone receptors, estrogen and progesterone, and in tumors with high pathologic grade and proliferation index; high RANK/RANKL expression was significantly associated with metastatic tumors. Together, our findings show that RANK promotes tumor initiation, progression, and metastasis in human mammary epithelial cells by increasing the population of CD44 þ CD24À cells, inducing stemness and EMT. These results suggest that RANK expression in primary breast cancer associates with poor prognosis. Cancer Res; 72(11); 2879-88. Ó2012 AACR.