Attitudes among dermatologists regarding non-melanoma skin cancer treatment options

Silencing of Dicer enhances dacarbazine resistance in melanoma cells by inhibiting ADSL expression

Dacarbazine (DTIC) is the primary first-line treatment for advanced-stage metastatic melanoma; thus, DTIC resistance is poses a major challenge. Therefore, investigating the mechanism underlying DTIC resistance must be investigated. Dicer, a type III cytoplasmic endoribonuclease, plays a pivotal role in the maturation of miRNAs. Aberrant Dicer expression may contribute to tumor progression, clinical aggressiveness, and poor prognosis in various tumors. Dicer inhibition led to a reduction in DTIC sensitivity and an augmentation in stemness in melanoma cells. Clinical analyses indicated a low Dicer expression level as a predictor of poor prognosis factor. Metabolic alterations in tumor cells may interfere with drug response. Adenylosuccinate lyase (ADSL) is a crucial enzyme in the purine metabolism pathway. An imbalance in ADSL may interfere with the therapeutic efficacy of drugs. We discovered that DTIC treatment enhanced ADSL expression and that Dicer silencing significantly reduced ADSL expression in melanoma cells. Furthermore, ADSL overexpression reversed Dicer silencing induced DTIC resistance and cancer stemness. These findings indicate that Dicer-mediated ADSL regulation influences DTIC sensitivity and stemness in melanoma cells.

Serine and one-carbon metabolism sustain non-melanoma skin cancer progression

Non-melanoma skin cancer (NMSC) is a tumor that arises from human keratinocytes, showing abnormal control of cell proliferation and aberrant stratification. Cutaneous basal cell carcinoma (cBCC) and cutaneous squamous cell carcinoma (cSCC) are the most common sub-types of NMSC. From a molecular point of view, we are still far from fully understanding the molecular mechanisms behind the onset and progression of NMSC and to unravel targetable vulnerabilities to leverage for their treatment, which is still essentially based on surgery. Under this assumption, it is still not elucidated how the central cellular metabolism, a potential therapeutical target, is involved in NMSC progression. Therefore, our work is based on the characterization of the serine anabolism/catabolism and/or one-carbon metabolism (OCM) role in NMSC pathogenesis. Expression and protein analysis of normal skin and NMSC samples show the alteration of the expression of two enzymes involved in the serine metabolism and OCM, the Serine Hydroxy-Methyl Transferase 2 (SHMT2) and Methylen-ThetraHydroFolate dehydrogenase/cyclohydrolase 2 (MTHFD2). Tissues analysis shows that these two enzymes are mainly expressed in the proliferative areas of cBCC and in the poorly differentiated areas of cSCC, suggesting their role in tumor proliferation maintenance. Moreover, in vitro silencing of SHMT2 and MTHFD2 impairs the proliferation of epidermoid cancer cell line. Taken together these data allow us to link the central cellular metabolism (serine and/or OCM) and NMSC proliferation and progression, offering the opportunity to modulate pharmacologically the involved enzymes activity against this type of human cancer.

Testing some psychometric properties of the Italian version of the Skin Cancer Index: A questionnaire for measuring quality of life in patients with non-melanoma skin cancer

OBJECTIVES

Non-melanoma skin cancers (NMSC) include two main types: basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). Generic Health-Related Quality of Life (HRQoL) instruments revealed little to no HRQoL impairment in NMSC patients. Instead, the use of specific skin disease HRQoL tools contradicted those observations. For example, the Skin Cancer Index (SCI) was suggested as a validated instrument for the evaluation of the impact of skin cancers on HRQoL, and has already been validated in several languages, but not in Italian. The aim of this study is to testing some psychometric properties of the Italian version of the SCI questionnaire in a large sample of NMSC patients.

METHODS

This is a cross-sectional, single-center, observational study. Firstly, different factor models proposed in the literature were compared and the model with the best fit was identified. Secondly, the psychometric properties of the SCI, convergent validity and reliability, were evaluated.

RESULTS

The sample was composed of 371 NMSC patients. The factor analysis revealed that a revised version of the original model had the best fit [χ2(df = 85) = 354.53, p < 0.001, RMSEA = 0.09, CFI = 0.98, TLI = 0.97, SRMR = 0.03]. The SCI had satisfactory internal consistency for all subscales (Emotional subscale: ordinal alpha = 0.95; Social subscale: ordinal alpha = 0.94; Appearance subscale: ordinal alpha = 0.94). The convergent validity with Skindex-17 psychosocial subscale was adequate for all the SCI subscales (Emotional Subscale: rho = -0.50; Social Subscale: rho = -0.54; Appearance subscale: rho = -0.44; Total Skin Cancer Index: rho = -0.56; and p < 0.001).

CONCLUSION

The tested psychometric properties of the Italian version of the SCI may suggest that it is an appropriate tool to measure the HRQoL in NMSC patients, however, further studies are needed in order to confirm and tested other psychometric features of this tool.

Distinct interactors define the p63 transcriptional signature in epithelial development or cancer

The TP63 is an indispensable transcription factor for development and homeostasis of epithelia and its derived glandular tissue. It is also involved in female germline cell quality control, muscle and thymus development. It is expressed as multiple isoforms transcribed by two independent promoters, in addition to alternative splicing occurring at the mRNA 3′-UTR. Expression of the TP63 gene, specifically the amino-deleted p63 isoform, ΔNp63, is required to regulate numerous biological activities, including lineage specification, self-renewal capacity of epithelial stem cells, proliferation/expansion of basal keratinocytes, differentiation of stratified epithelia. In cancer, ΔNp63 is implicated in squamous cancers pathogenesis of different origin including skin, head and neck and lung and in sustaining self-renewal of cancer stem cells. How this transcription factor can control such a diverse set of biological pathways is central to the understanding of the molecular mechanisms through which p63 acquires oncogenic activity, profoundly changing its down-stream transcriptional signature. Here, we highlight how different proteins interacting with p63 allow it to regulate the transcription of several central genes. The interacting proteins include transcription factors/regulators, epigenetic modifiers, and post-transcriptional modifiers. Moreover, as p63 depends on its interactome, we discuss the hypothesis to target the protein interactors to directly affect p63 oncogenic activities and p63-related diseases.