Cutaneous squamous cell carcinoma (cSCC) has a high tumour mutational burden (50 mutations per megabase DNA pair). Here, we combine whole-exome analyses from 40 primary cSCC tumours, comprising 20 well-differentiated and 20 moderately/poorly differentiated tumours, with accompanying clinical data from a longitudinal study of immunosuppressed and immunocompetent patients and integrate this analysis with independent gene expression studies. We identify commonly mutated genes, copy number changes and altered pathways and processes. Comparisons with tumour differentiation status suggest events which may drive disease progression. Mutational signature analysis reveals the presence of a novel signature (signature 32), whose incidence correlates with chronic exposure to the immunosuppressive drug azathioprine. Characterisation of a panel of 15 cSCC tumour-derived cell lines reveals that they accurately reflect the mutational signatures and genomic alterations of primary tumours and provide a valuable resource for the validation of tumour drivers and therapeutic targets.

The influential role of Wnt5a in tumor progression underscores the requirement for developing molecules that can target Wnt5a-mediated cellular responses. In the aggressive skin cancer, melanoma, elevated Wnt5a expression promotes cell motility and drives metastasis. Two approaches can be used to counteract these effects: inhibition of Wnt5a expression or direct blockade of Wnt5a signaling. We have investigated both options in the melanoma cell lines, A2058 and HTB63. Both express Frizzled-5, which has been implicated as the receptor for Wnt5a in melanoma cells. However, only the HTB63 cell line expresses and secretes Wnt5a. In these cells, the cytokine, TGF␤1, controlled the expression of Wnt5a, but due to the unpredictable effects of TGF␤1 signaling on melanoma cell motility, targeting Wnt5a signaling via TGF␤1 was an unsuitable strategy to pursue. We therefore attempted to target Wnt5a signaling directly. Exogenous Wnt5a stimulation of A2058 cells increased adhesion, migration and invasion, all crucial components of tumor metastasis, and the Wnt5a-derived N-butyloxycarbonyl hexapeptide (Met-Asp-Gly-Cys-Glu-Leu; 0.766 kDa) termed Box5, abolished these responses. Box5 also inhibited the basal migration and invasion of Wnt5a-expressing HTB63 melanoma cells. Box5 antagonized the effects of Wnt5a on melanoma cell migration and invasion by directly inhibiting Wnt5a-induced protein kinase C and Ca 2؉ signaling, the latter of which we directly demonstrate to be essential for cell invasion. The Box5 peptide directly inhibits Wnt5a signaling, representing an approach to anti-metastatic therapy for otherwise rapidly progressive melanoma, and for other Wnt5a-stimulated invasive cancers.inhibitory peptide ͉ malignant melanoma ͉ tumor cell invasion W nt ligands comprise a family of 19 human secreted signaling proteins, which coordinate essential processes required for development and maintenance of tissue homeostasis. Misregulation of Wnt signaling can lead to cancer progression (1). The Wnt ligands are secreted glycoproteins that can be divided based on their ability to activate different intracellular signals, in a tissue-dependent manner. One group primarily activates canonical signaling that controls ␤-catenin stability, while the other is loosely described as ␤-catenin-transcriptionally independent (non-canonical Wnt signaling). However, cross-talk between the two signaling networks does exist (2).Wnt5a is in most situations characterized as a non-canonical Wnt ligand that elicits intracellular signals through association with distinct receptors and co-receptors in a cell specific manner. Wnt5a has been shown to stimulate increases in intracellular Ca 2ϩ levels in developmental models (3) and mammalian cell lines, including breast and thyroid cancer cells (4-6), giving rise to the model of a non-canonical Wnt/Ca 2ϩ signaling pathway. Wnt5a-mediated intracellular increases in Ca 2ϩ levels enables the activation of Ca 2ϩ -regulated proteins, such as protein kinase C (PKC) in a context dependent manner, as reviewed recen...

WNT signaling was discovered in tumor models and has been recognized as a regulator of cancer development and progression for over 3 decades. Recent work has highlighted a critical role for WNT signaling in the metabolic homeostasis of mammals, where its misregulation has been heavily implicated in diabetes. While the majority of WNT metabolism research has focused on nontransformed tissues, the role of WNT in cancer metabolism remains underinvestigated. Cancer is also a metabolic disease where oncogenic signaling pathways regulate energy production and macromolecular synthesis to fuel rapidly proliferating tumors. This review highlights the emerging evidence for WNT signaling in the reprogramming of cancer cell metabolism and examines the role of these signaling pathways as mediators of tumor bioenergetics.

Mitosis is a fundamental feature of all cellular organisms. It must be tightly regulated to allow normal tissue growth and to prevent cancer formation. Here, we identify a new protein that is required for mitosis. We show that the Ras association (RA) domain-containing protein, RASSF7, is part of an evolutionarily conserved group of four proteins. These are RASSF7, RASSF8, and two new RASSF proteins P-CIP1/RASSF9 and RASSF10. We call this group the N-terminal RASSF family. We analyzed the function of Xenopus RASSF7. RASSF7 was found to be expressed in several embryonic tissues including the skin, eyes, and neural tube. Knocking down its function led to cells failing to form a mitotic spindle and arresting in mitosis. This caused nuclear breakdown, apoptosis, and a striking loss of tissue architecture in the neural tube. Consistent with a role in spindle formation, RASSF7 protein was found to localize to the centrosome. This localization occurred in a microtubule-dependent manner, demonstrating that there is a mutually dependant relationship between RASSF7 localization and spindle formation. Thus RASSF7, the first member of the N-terminal RASSF family to be functionally analyzed, is a centrosome-associated protein required to form a spindle and complete mitosis in the neural tube. INTRODUCTIONMitosis is a fundamental biological process found in all cellular organisms. During mitosis in animal cells the centrosomes organize microtubule networks to establish the mitotic spindle. This requires the cooperation of several processes including microtubule nucleation, stability, and anchorage. It involves a network of proteins that are closely associated with the centrosome, including ␥-tubulin, which forms a ␥-tubulin ring complex (␥-TuRC) and initiates microtubule nucleation (Moritz et al., 1995;Zheng et al., 1995). Without this control of microtubules, correct mitosis cannot occur. A multitude of signaling molecules are also found clustered at the centrosome. Prominent examples include the mitotic kinases such as polo-like kinase (PLK) 1, 2, and 4 (Barr et al., 2004), AuroraA (Carmena andEarnshaw, 2003), and Nek2 (Hayward andFry, 2006). Active Cdk1, the kinase that controls mitotic initiation, also first appears at the centrosome (Jackman et al., 2003). This suggests that the centrosome, in addition to regulating microtubules, functions as a signaling platform which regulates different aspects of mitosis (Basto and Pines, 2007). A link between aberrant control of mitosis and cancer progression has been suspected for almost 100 years (Balmain, 2001), and many regulators of mitosis are now known to be tumor suppressors or oncogenes (Malumbres and Barbacid, 2007). Thus identifying the centrosomal proteins responsible for controlling mitosis is crucial for explaining this key biological process but also for understanding tumor progression.One group of proteins that are linked to mitosis and cancer progression is the Ras-association domain (RASSF) family. Classically, the vertebrate RASSF family (reviewed in the introducti...