TP63 is implicated in apoptotic dysregulation in melanoma

PhDCutaneous melanoma is an aggressive malignancy accounting for 4% of skin cancers but 80% of all skin-cancer related deaths. Its incidence is rapidly rising and advanced disease is notoriously treatment-resistant. The role of apoptosis in melanoma pathogenesis and chemoresistance is poorly characterised. Mutations in TP53 occur infrequently and are not critical for tumour development, yet the TP53 apoptotic pathway is abrogated; this may alternatively result from TP53 pathway defects or from alterations in other members of the TP53 family, including the TP53 homologue, TP63. The hypothesis of this thesis was that TP63 has an anti-apoptotic role in melanoma and is responsible for mediating chemoresistance. The primary aims were to investigate the biological role of TP63 in melanoma, to explore regulation of p63 expression and to understand its role in apoptosis and dysregulation of the TP53 apoptotic pathway in melanoma. Although p63 was not expressed in primary melanocytes, upregulation of both p63 mRNA and protein was observed in melanoma cell lines and tissue samples. This is the first report of significant p63 expression in this lineage. Furthermore, aberrant cytoplasmic p63 expression significantly correlated with poor overall outcome in melanoma patients. Multiple possible mechanisms were demonstrated to regulate TP63 expression in melanoma, including epigenetic modulation, microRNA regulation of gene transcription and proteosome-dependent stability of p63 protein. In response to genotoxic stress, endogenous p63 isoforms were stabilised in both nuclear and mitochondrial subcellular compartments. Translocation of p63 to the mitochondria occurred through a co-dependent process with p53 but accumulation of wt-p53 in the nucleus was inhibited by p63. Using RNAi technology, both isoforms of p63 (TA and ΔNp63) were demonstrated to confer chemoresistance in melanoma. In addition, the truncated variant, ΔNp63, was enriched in a subset of melanomas expressing CD133, pointing to an anti-apoptotic role for p63 in putative cancer stem cells in this aggressive tumour. Taken together, these data suggest that in melanoma, p63 is an oncogene which contributes to dysregulation of wt-p53 function and has an important role in mediating chemoresistance. Ultimately, these observations may provide the rationale for novel approaches aimed at sensitising advanced melanoma to chemotherapeutic agents

iASPP/p63 autoregulatory feedback loop is required for the homeostasis of stratified epithelia

iASPP, an inhibitory member of the ASPP (apoptosis stimulating protein of p53) family, is an evolutionarily conserved inhibitor of p53 which is frequently upregulated in human cancers. However, little is known about the role of iASPP under physiological conditions. Here, we report that iASPP is a critical regulator of epithelial development. We demonstrate a novel autoregulatory feedback loop which controls crucial physiological activities by linking iASPP to p63, via two previously unreported microRNAs, miR-574-3p and miR-720. By investigating its function in stratified epithelia, we show that iASPP participates in the p63-mediated epithelial integrity program by regulating the expression of genes essential for cell adhesion. Silencing of iASPP in keratinocytes by RNA interference promotes and accelerates a differentiation pathway, which also affects and slowdown cellular proliferation. Taken together, these data reveal iASPP as a key regulator of epithelial homeostasis

Development of a core outcome set for basal cell carcinoma

Background: There is variation in the outcomes reported in clinical studies of basal cell carcinoma. This can prevent effective meta-analyses from answering important clinical questions. Objective: To identify a recommended minimum set of core outcomes for basal cell carcinoma clinical trials. Methods: Patient and professional Delphi process to cull a long list, culminating in a consensus meeting. To be provisionally accepted, outcomes needed to be deemed important (score, 7-9, with 9 being the maximum) by 70% of each stakeholder group. Results: Two hundred thirty-five candidate outcomes identified via a systematic literature review and survey of key stakeholders were reduced to 74 that were rated by 100 health care professionals and patients in 2 Delphi rounds. Twenty-seven outcomes were provisionally accepted. The final core set of 5 agreed-upon outcomes after the consensus meeting included complete response; persistent or serious adverse events; recurrence-free survival; quality of life; and patient satisfaction, including cosmetic outcome. Limitations: English-speaking patients and professionals rated outcomes extracted from English language studies. Conclusion: A core outcome set for basal cell carcinoma has been developed. The use of relevant measures may improve the utility of clinical research and the quality of therapeutic guidance available to clinicians. Keywords: basal cell carcinoma; core; measure; outcome; set; skin cancer

Development of a core outcome set for cutaneous squamous cell carcinoma trials: identification of core domains and outcomes

International audienceBackground: The lack of uniformity in the outcomes reported in clinical studies of the treatment of cutaneous squamous cell carcinoma (cSCC) complicates efforts to compare treatment effectiveness across trials. Objectives: To develop a core outcome set (COS), a minimum set of agreed-upon outcomes to be measured in all clinical trials of a given disease or outcome, for the treatment of cSCC. Methods: One hundred and nine outcomes were identified via a systematic literature review and interviews with 28 stakeholders. After consolidation of this long list, 55 candidate outcomes were rated by 19 physician and 10 patient stakeholders, in two rounds of Delphi exercises. Outcomes scored ‘critically important’ (score of 7, 8 or 9) by ≥ 70% of patients and ≥ 70% of physicians were provisionally included. At the consensus meeting, after discussion and voting of 44 international experts and patients, the provisional list was reduced to a final core set, for which consensus was achieved among all meeting participants. Results: A core set of seven outcomes was finalized at the consensus meeting: (i) serious or persistent adverse events, (ii) patient-reported quality of life, (iii) complete response, (iv) partial response, (v) recurrence-free survival, (vi) progression-free survival and (vii) disease-specific survival. Conclusions: In order to increase the comparability of results across trials and to reduce selective reporting bias, cSCC researchers should consider reporting these core outcomes. Further work needs to be performed to identify the measures that should be reported for each of these outcomes

Development of a core outcome set for basal cell carcinoma

BACKGROUND: There is variation in the outcomes reported in clinical studies of basal cell carcinoma (BCC). This can prevent effective meta-analyses to answer important clinical questions. OBJECTIVE: To identify a recommended minimum set of core outcomes for BCC clinical trials. METHODS: Patient and professional Delphi process to cull a long-list, culminating in a consensus meeting. To be provisionally accepted, outcomes needed to be deemed 'important' (score: 7-9, of maximum of 9) by 70% of each stakeholder group. RESULTS: 235 candidate outcomes identified via a systematic literature review and survey of key stakeholders were reduced to 74 that were rated by 100 health care professionals and patients in two Delphi rounds. 27 outcomes were provisionally accepted. The final core set of 5 agreed-upon outcomes after the consensus meeting was: complete response; persistent or serious adverse events; recurrence-free survival; quality of life; and patient satisfaction, including with cosmetic outcome. LIMITATIONS: English-speaking patients and professionals rated outcomes extracted from English-language studies. CONCLUSIONS: A core outcome set (COS) for basal cell carcinoma has been developed. Use of relevant measures may improve the utility of clinical research and the quality of therapeutic guidance available to clinicians