Malignant Melanoma is a highly aggressive form of skin cancer known to metastasize to different organs among which lung is the most frequently associated to fatal outcome. TPC2 is a calcium/sodium channel, localized predominantly on the acidic stores membranes such as late-endosomes, lysosomes and melanosomes. There is increasing evidence that links two-pore channel 2 (TPC2) to cancer, revealing the potential applications of TPC2 as a biomarker in the definition of tumour types, susceptibility, prognosis, response and cancer outcomes. Our central hypothesis is that two-pore channels play a pivotal role in the processes of tumorigenesis and metastasis and that they are possible cancer biomarkers and targets for cancer treatment and specifically for melanoma. We expect to identify a set of clinical and dermoscopic different melanoma subtypes features that significantly correlate with a novel "signature" encompassing genetic mutation and biologic alteration in NAADP/TPC2 signaling pathways. We will examine TPC2 profiling as novel and promising detection, diagnostic, prognostic and predictive melanoma biomarkers. In addition, we will investigate the role of TPC2 in angiogenesis, tumorigenesis and metastasis processes using functional assays and by overexpression or silencing of the TPCN2 gene in in vitro models. Moreover, we will develop in vitro models to examine the role of the identified novel mutations and level of expression of the TPCN2 gene during melanoma progression formation and cancer cell migration in different melanoma subtypes. These findings will add to our understanding of the mechanisms of tumourigenesis and metastasis and could help identify new ways to diagnose and treat melanoma and other metastatic cancers.
Epidemiologic data from Europe indicate a continuous and dramatic increase in melanoma incidence during the last decades (13.2 and 13.1 new cases per year, per 100,000 for men and women, respectively). In Italy, approximately 3.150 new cases for men and 2.850 for women were diagnosed every year (Italian Agency of tumor records). Despite the great progress of therapeutic strategies like kinase inhibitors for BRAF-mutant melanoma and immune checkpoint blockers within the past few years, long-term survival of 5 years and more was only achieved in 5-10% of patients with metastatic melanoma regardless of the specific therapeutic strategy used. Encouraging results were obtained in patients with stage III melanoma receiving both neoadjuvant and adjuvant treatments. Adjuvant and neoadjuvant therapy have several potential advantages, including a possibility of decreased surgical morbidity, prevention of micrometastases, personalization of adjuvant therapy based on the response to neoadjuvant therapy. The great scientific potential of this project is first based on the identification of TPC2 as a novel target for melanoma metastasis. The molecular characterization of the melanoma subtypes, as detected by dermoscopy and confocal microscopy will possibly lead to identifying novel and more targeted therapies. The chance to collect bio-specimens derived from different melanoma subtypes would be fundamental for the identification of the morphologic-biomolecular profile and for the evaluation of the different response to TPC2 inhibition target therapy. We expect to identify a set of clinical, dermoscopic (very high magnification) and different melanoma subtypes features that significantly correlate with a novel "signature" encompassing genetic mutation and biologic alteration in NAADP/TPC2 signaling pathways. A better knowledge of NAADP/TPC2 signaling pathway and their involvement in melanoma metastasis could be relevant to define tumor aggressiveness among different melanoma subtypes. In this respect, blocking their signaling, as novel targets of therapy in selected melanoma subtypes, is of special importance. In particular, this approach would be an alternative to immunotherapy which fails to take into account patients' characteristics or selective biomarkers. The tumor differentiation based on cyto-morphology (as seen by in vivo confocal microscopy) and molecular profile will help to define the different therapeutic strategies to be applied in different melanoma types according to their predominant pathway and the need of combination or sequential therapy in order to fight tumour drug resistance and escape. Given the heterogeneity of melanoma cells, this will ultimately lead to a personalized therapy for melanoma.