TP63 mutations are frequent in cutaneous melanoma, support UV etiology, but their role in melanomagenesis is unclear

In contrast to TP53, cancer development is rarely associated with mutations in the TP63 and TP73 genes. Recently, next generation sequencing analysis revealed that TP63 mutations are frequent, specifically in cutaneous melanomas. Cutaneous melanoma represents 4% of skin cancers but it is responsible for 80% of skin cancer related deaths. In the present study, we first determined whether all three members of the P53 family of transcription factors were found mutated in cutaneous melanomas by retrieving all TP53, TP63 and TP73 mutations from cBioPortal (http://www.cbioportal.org/). TP53 and TP63 were frequently mutated [15.0% (91/605) and 14.7% (89/605), respectively], while TP73 [1.5% (9/605)] was more rarely mutated (p<0.0001). A UV-mutation fingerprint was recognized for TP63 and TP73 genes. Then, we tried to evaluate the potential role of TP63 mutations as drivers or passengers in the tumorigenic process. In the former case, the amino acid substitutions should cause significant functional consequences on the main biochemical activity of the P63 protein, namely transactivation. The predicted effects of specific amino acid substitutions by two bioinformatics tools were rather different. Using a yeast-based functional assay, the observed hotspot mutant R379CP63 protein exhibited a substantial residual activity compared to the wild-type (>70%). This result does not support a major role of the mutant P63 protein in melanomagenesis while it is still consistent with the TP63 gene being a recorder of UV exposure. The TP63 mutation spectrum from cutaneous melanomas, when compared with that observed at the germinal level in patients affected by P63-associated diseases [ectodermal dysplasia syndromes, (EDs)], revealed significant differences. The TP63 mutations were more frequent at CpGs sites (p<0.0001) in EDs and at PyPy sites (p<0.0001) in cutaneous melanomas. The two spectra differed significantly (p<0.0001). We conclude that TP63 mutations are frequent in cutaneous melanoma, support UV etiology, but their role in melanomagenesis is unclear

Sex hormone modulation of cell growth and apoptosis of the human monocytic/macrophage cell line

Sex hormones seem to modulate the immune/inflammatory responses by different mechanisms in female and male rheumatoid arthritis patients. The effects of 17β-oestradiol and of testosterone were tested on the cultured human monocytic/macrophage cell line (THP-1) activated with IFN-γ in order to investigate their role in cell proliferation and apoptosis. Activated human THP-1 cells were cultured in the presence of 17β-oestradiol and testosterone (final concentration, 10 nM). The evaluation of markers of cell proliferation included the NF-κB DNA-binding assay, the NF-κB inhibition complex, the proliferating cell nuclear antigen expression and the methyl-tetrazolium salt test. Apoptosis was detected by the annexin V-propidium assay and by the cleaved poly-ADP ribose polymerase expression. Specific methods included flow analysis cytometry scatter analysis, immunocytochemistry and western blot analysis. Cell growth inhibition and increased apoptosis were observed in testosterone-treated THP-1 cells. Increased poly-ADP ribose polymerase-cleaved expression and decreased proliferating cell nuclear antigen expression, as well as an increase of IκB-α and a decrease of the IκB-α phosphorylated form (ser 32), were found in testosterone-treated THP-1 cells. However, the NF-κB DNA binding was found increased in 17β-oestradiol-treated THP-1 cells. The treatment with staurosporine (enhancer of apoptosis) induced decreased NF-κB DNA binding in all conditions, but particularly in testosterone-treated THP-1 cells. Treatment of THP-1 by sex hormones was found to influence cell proliferation and apoptosis. Androgens were found to increase the apoptosis, and oestrogens showed a protective trend on cell death – both acting as modulators of the NF-κB complex

Combining molecular and immunohistochemical analyses of key drivers in primary melanomas: Interplay between germline and somatic variations

Due to the high mutational somatic burden of Cutaneous Malignant Melanoma (CMM) a thorough profiling of the driver mutations and their interplay is necessary to explain the timing of tumorigenesis or for the identification of actionable genetic events. The aim of this study was to establish the mutation rate of some of the key drivers in melanoma tumorigenesis combining molecular analyses and/or immunohistochemistry in 93 primary CMMs from an Italian cohort also characterized for germline status, and to investigate an interplay between germline and somatic variants. BRAF mutations were present in 68% of cases, while CDKN2A germline mutations were found in 16 % and p16 loss in tissue was found in 63%. TERT promoter somatic mutations were detected in 38% of cases while the TERT -245T > C polymorphism was found in 51% of cases. NRAS mutations were found in 39% of BRAF negative or undetermined cases. NF1 was expressed in all cases analysed. MC1R variations were both considered as a dichotomous variable or scored. While a positive, although not significant association between CDKN2A germline mutations, but not MC1R variants, and BRAF somatic mutation was found, we did not observe other associations between germline and somatic events. A yet undescribed inverse correlation between TERT -245T > C polymorphism and the presence of BRAF mutation was found. It is possible to hypothesize that -245T > C polymorphism could be included in those genotypes which may influence the occurrence of BRAF mutations. Further studies are needed to investigate the role of -245T > C polymorphism as a germline predictor of BRAF somatic mutation status

Hereditary trichilemmal cysts: a proposal for the assessment of diagnostic clinical criteria

Trichilemmal cysts (TCs) can occur as sporadic lesions or in hereditary-familial settings with autosomal dominant transmission. These entities have not been widely analyzed in their peculiar aspects yet. The aim of this study was to describe a cohort of patients with diagnosis of TCs through a clinical and biomolecular characterization, intended to highlight some effective diagnostic criteria for their identification. Among 149 cases of this study, 24 cases of TCs (16.1%) arose in patients with at least one first-degree relative with diagnosis of TCs. Peculiar findings concerning hereditary lesions included the multiple presentation with an early onset age. On the basis of clinical evaluation, we propose a panel of clinical and histologic criteria for the diagnosis of hereditary TCs, which includes: (i) the diagnosis of TCs in at least two first-degree relatives or in three first- or second-degree relatives in two consecutive generations; (ii) at least one of the patients with TCs diagnosed <45 years; and (iii) the diagnosis of multiple or giant (>5-cm lesions) or rare histopathologic features (proliferating and ossifying) TCs

Heterogeneity and frequency of BRAF mutations in primary melanoma: Comparison between molecular methods and immunohistochemistry

Finding the best technique to identify BRAF mutations with a high sensitivity and specificity is mandatory for accurate patient selection for target therapy. BRAF mutation frequency ranges from 40 to 60% depending on melanoma clinical characteristics and detection technique used. Intertumoral heterogeneity could lead to misinterpretation of BRAF mutational status; this is especially important if testing is performed on primary specimens, when metastatic lesions are unavailable. Aim of this study was to identify the best combination of methods for detecting BRAF mutations (among peptide nucleic acid - PNA-clamping real-time PCR, immunohistochemistry and capillary sequencing) and investigate BRAF mutation heterogeneity in a series of 100 primary melanomas and a subset of 25 matched metastatic samples. Overall, we obtained a BRAF mutation frequency of 62%, based on the combination of at least two techniques. Concordance between mutation status in primary and metastatic tumor was good but not complete (67%), when agreement of at least two techniques were considered. Next generation sequencing was used to quantify the threshold of detected mutant alleles in discordant samples. Combining different methods excludes that the observed heterogeneity is technique-based. We propose an algorithm for BRAF mutation testing based on agreement between immunohistochemistry and PNA; a third molecular method could be added in case of discordance of the results. Testing the primary tumor when the metastatic sample is unavailable is a good option if at least two methods of detection are used, however the presence of intertumoral heterogeneity or the occurrence of additional primaries should be carefully considered

Efficacy of novel immunotherapy regimens in patients with metastatic melanoma with germline CDKN2A mutations

Background: Inherited CDKN2A mutation is a strong risk factor for cutaneous melanoma. Moreover, carriers have been found to have poor melanoma-specific survival. In this study, responses to novel immunotherapy agents in CDKN2A mutation carriers with metastatic melanoma were evaluated. Methods: CDKN2A mutation carriers that have developed metastatic melanoma and undergone immunotherapy treatments were identified among carriers enrolled in follow-up studies for familial melanoma. The carriers' responses were compared with responses reported in phase III clinical trials for CTLA-4 and PD-1 inhibitors. From publicly available data sets, melanomas with somatic CDKN2A mutation were analysed for association with tumour mutational load. Results: Eleven of 19 carriers (58%) responded to the therapy, a significantly higher frequency than observed in clinical trials (p=0.03, binomial test against an expected rate of 37%). Further, 6 of the 19 carriers (32%) had complete response, a significantly higher frequency than observed in clinical trials (p=0.01, binomial test against an expected rate of 7%). In 118 melanomas with somatic CDKN2A mutations, significantly higher total numbers of mutations were observed compared with 761 melanomas without CDKN2A mutation (Wilcoxon test, p<0.001). Conclusion: Patients with CDKN2A mutated melanoma may have improved immunotherapy responses due to increased tumour mutational load, resulting in more neoantigens and stronger antitumorous immune responses

Sphenoid asymmetry associated to other skeletal anomalies in a clear cut case of PTCH1 mutated Gorlin-Goltz syndrome: a novel finding?

Gorlin-Goltz syndrome is an autosomal dominantly inherited disorder linked to PTCH1 mutation, recognized by a collection of clinical and radiologic signs (macrocephaly, frontal bossing, multiple intracranial calcifications including falx cerebri and atlanto-occipital ligament). We describe here a the case of a family with clear cut criteria for Gorlin-Goltz syndrome presenting the association of cranio-facial and skeletal anomalies together with a peculiar sphenoid variant. Two patients, father and son, were examined because of multiple basal cell carcinomas and keratocystic odontogenic tumours. Other suggestive findings were multiple positive family history, typical skeletal anomalies and a novel PTCH1 germline mutation (c.1041delAA). Craniofacial and other skeletal anomalies displayed at 3D and helical CT scan were: macrocephaly, skull base asymmetry (positional plagiocephaly), mandibular prognathism, mandibular condylar deformation with hyperplasia of the coronoid process, bifidity of multiple ribs and giant multilocular odontogenic jaw cysts. Extensive multilamellar calcifications were found in falx cerebri, tentorium, falx cerebelli and in the apical segment of the atlanto-occipital ligament. Thoracic anomalies included bifid left 3rd, 4th, 5th and 6th rib, dismorphic body of the 3rd thoracic vertebra, dorsolumbar scoliosis, sacrum acutum. Interestingly, 3D-CT scan showed asymmetry of both sphenoid wings with thickening of the left wing sphenoid wing together with irregularity of the architecture of trabecular bone with alternating osteolytic and sclerotic areas. Abnormalities of the sphenoid bone are not very common, and consist of differently aggressive entities: some of them are typical of the pediatric age in few hereditary and congenital disorders. The application of new criteria (i.e. peculiar calcifications of ligaments and sphenoid asymmetry) to a wider case series can lead to the early diagnosis of Gorlin syndrome, especially in pediatric patients, when the full phenotype is not yet expressed. The inclusion of bifid ribs as a novel major criteria and the recognition of peculiar cranial anomalies such as sphenoid asymmetry, well detected at volume CT reconstruction, might be useful for the recognition and characterization of misdiagnosed cases

Efficacy of novel immunotherapy regimens in patients with metastatic melanoma with germline CDKN2A mutations

Inherited CDKN2A mutation is a strong risk factor for cutaneous melanoma. Moreover, carriers have been found to have poor melanoma-specific survival. In this study, responses to novel immunotherapy agents in CDKN2A mutation carriers with metastatic melanoma were evaluated

Contribution of Common Genetic Variants to Familial Aggregation of Disease and Implications for Sequencing Studies

Despite genetics being accepted as the primary cause of familial aggregation for most diseases, it is still unclear whether afflicted families are likely to share a single highly penetrant rare variant, many minimally penetrant common variants, or a combination of the two types of variants. We therefore use recent estimates of SNP heritability and the liability threshold model to estimate the proportion of afflicted families likely to carry a rare, causal variant. We then show that Polygenic Risk Scores (PRS) may be useful for identifying families likely to carry such a rare variant and therefore for prioritizing families to include in sequencing studies with that aim. Specifically, we introduce a new statistic that estimates the proportion of individuals carrying causal rare variants based on the family structure, disease pattern, and PRS of genotyped individuals. Finally, we consider data from the MelaNostrum consortium and show that, despite an estimated PRS heritability of only 0.05 for melanoma, families carrying putative causal variants had a statistically significantly lower PRS, supporting the idea that PRS prioritization may be a useful future tool. However, it will be important to evaluate whether the presence of rare mendelian variants are generally associated with the proposed test statistic or lower PRS in future and larger studies

Contribution of Common Genetic Variants to Familial Aggregation of Disease and Implications for Sequencing Studies

Despite genetics being accepted as the primary cause of familial aggregation for most diseases, it is still unclear whether afflicted families are likely to share a single highly penetrant rare variant, many minimally penetrant common variants, or a combination of the two types of variants. We therefore use recent estimates of SNP heritability and the liability threshold model to estimate the proportion of afflicted families likely to carry a rare, causal variant. We then show that Polygenic Risk Scores (PRS) may be useful for identifying families likely to carry such a rare variant and therefore for prioritizing families to include in sequencing studies with that aim. Specifically, we introduce a new statistic that estimates the proportion of individuals carrying causal rare variants based on the family structure, disease pattern, and PRS of genotyped individuals. Finally, we consider data from the MelaNostrum consortium and show that, despite an estimated PRS heritability of only 0.05 for melanoma, families carrying putative causal variants had a statistically significantly lower PRS, supporting the idea that PRS prioritization may be a useful future tool. However, it will be important to evaluate whether the presence of rare mendelian variants are generally associated with the proposed test statistic or lower PRS in future and larger studies