Eduardo Nagore

TERT Promoter Mutations in Familial and Sporadic Melanoma.

Promoter Mutations and Cancer Cancer genome sequencing projects have highlighted the pathogenic role of recurrent mutations within the protein-coding regions of genes. Now, two studies suggest that the scope of mutations in human tumors extends to gene regulatory regions. In a study of 70 melanomas, Huang et al. (p. 957, published online 24 January) found that 71% harbored one of two specific mutations in the promoter region of TERT, the gene coding for the catalytic subunit of telomerase, the enzyme that caps chromosome ends. Independently, Horn et al. (p. 959, published online 24 January) identified a disease-segregating germline mutation in the TERT promoter in a family predisposed to melanoma and found additional TERT promoter mutations in a high percentage of sporadic melanomas and melanoma cell lines. The mutations in both studies generated new binding sites for specific transcription factors and, in reporter assays, caused an increase in transcription. A large fraction of human melanomas harbor mutations in sequences that regulate the expression of telomerase. Cutaneous melanoma occurs in both familial and sporadic forms. We investigated a melanoma-prone family through linkage analysis and high-throughput sequencing and identified a disease-segregating germline mutation in the promoter of the telomerase reverse transcriptase (TERT) gene, which encodes the catalytic subunit of telomerase. The mutation creates a new binding motif for Ets transcription factors and ternary complex factors (TCFs) near the transcription start and, in reporter gene assays, caused up to twofold increase in transcription. We then screened the TERT promoter in sporadic melanoma and observed recurrent ultraviolet signature somatic mutations in 125 of 168 (74%) of human cell lines derived from metastatic melanomas, 45 of 53 corresponding metastatic tumor tissues (85%), and 25 of 77 (33%) primary melanomas. The majority of those mutations occurred at two positions in the TERT promoter and also generated binding motifs for Ets/TCF transcription factors.

Sequence variants at the TERT-CLPTM1L locus associate with many cancer types

The common sequence variants that have recently been associated with cancer risk are particular to a single cancer type or at most two. Following up on our genome-wide scan of basal cell carcinoma, we found that rs401681[C] on chromosome 5p15.33 satisfied our threshold for genome-wide significance (OR = 1.25, P = 3.7 × 10−12). We tested rs401681 for association with 16 additional cancer types in over 30,000 cancer cases and 45,000 controls and found association with lung cancer (OR = 1.15, P = 7.2 × 10−8) and urinary bladder, prostate and cervix cancer (ORs = 1.07−1.31, all P < 4 × 10−4). However, rs401681[C] seems to confer protection against cutaneous melanoma (OR = 0.88, P = 8.0 × 10−4). Notably, most of these cancer types have a strong environmental component to their risk. Investigation of the region led us to rs2736098[A], which showed stronger association with some cancer types. However, neither variant could fully account for the association of the other. rs2736098 corresponds to A305A in the telomerase reverse transcriptase (TERT) protein and rs401681 is in an intron of the CLPTM1L gene.

ASIP and TYR pigmentation variants associate with cutaneous melanoma and basal cell carcinoma

Fair color increases risk of cutaneous melanoma (CM) and basal cell carcinoma (BCC). Recent genome-wide association studies have identified variants affecting hair, eye and skin pigmentation in Europeans. Here, we assess the effect of these variants on risk of CM and BCC in European populations comprising 2,121 individuals with CM, 2,163 individuals with BCC and over 40,000 controls. A haplotype near ASIP, known to affect a similar spectrum of pigmentation traits as MC1R variants, conferred significant risk of CM (odds ratio (OR) = 1.45, P = 1.2 × 10−9) and BCC (OR = 1.35, P = 1.2 × 10−6). The variant in TYR encoding the R402Q amino acid substitution, previously shown to affect eye color and tanning response, conferred risk of CM (OR = 1.21, P = 2.8 × 10−7) and BCC (OR = 1.14, P = 6.1 × 10−4). An eye color variant in TYRP1 was associated with risk of CM (OR = 1.15, P = 4.3 × 10−4). The association of all three variants is robust with respect to adjustment for the effect of pigmentation.

New common variants affecting susceptibility to basal cell carcinoma

In a follow-up to our previously reported genome-wide association study of cutaneous basal cell carcinoma (BCC), we describe here several new susceptibility variants. SNP rs11170164, encoding a G138E substitution in the keratin 5 (KRT5) gene, affects risk of BCC (OR = 1.35, P = 2.1 × 10−9). A variant at 9p21 near CDKN2A and CDKN2B also confers susceptibility to BCC (rs2151280[C]; OR = 1.19, P = 6.9 × 10−9), as does rs157935[T] at 7q32 near the imprinted gene KLF14 (OR = 1.23, P = 5.7 × 10−10). The effect of rs157935[T] is dependent on the parental origin of the risk allele. None of these variants were found to be associated with melanoma or fair-pigmentation traits. A melanoma- and pigmentation-associated variant in the SLC45A2 gene, L374F, is associated with risk of both BCC and squamous cell carcinoma. Finally, we report conclusive evidence that rs401681[C] in the TERT-CLPTM1L locus confers susceptibility to BCC but protects against melanoma.

Antineoplastic Therapy-Induced Palmar Plantar Erythrodysesthesia ('Hand-Foot') Syndrome Incidence, Recognition and Management

Palmar plantar erythrodysesthesia (PPE) is a distinctive and relatively frequent toxic reaction related to some chemotherapeutic agents. Doxorubicin, cytarabine, docetaxel, and fluorouracil are the most frequently implicated agents. PPE seems to be dose dependent and both peak drug concentration and total cumulative dose determine its occurrence.PPE presents as a painful erythema, often preceded by paresthesia, located on the palms and soles in the context of treatment with chemotherapy. Histologically, PPE shows few specific findings. Mild spongiosis, scattered necrotic and dyskeratotic keratinocytes and vacuolar degeneration of the basal layer is seen. Dermal changes in most cases include dilated blood vessels, papillary edema, and a sparse superficial perivascular lymphohistiocytic infiltrate can be found in varying degrees in the epidermis.Withdrawal or dose reduction of the implicated drug usually gives rise to amelioration of the symptoms. Supportive treatments such as topical wound care, elevation, and cold compresses may help to relieve the pain. Use of systemic corticosteroids, pyridoxine (vitamin B6), blood flow reduction, and, recently, topical 99% dimethyl-sulfoxide have been used with variable outcomes. It could be of interest to consider them as preventive measures when drugs with a strong association with PPE are going to be administered.

Rare missense variants in POT1 predispose to familial cutaneous malignant melanoma

Although CDKN2A is the most frequent high-risk melanoma susceptibility gene, the underlying genetic factors for most melanoma-prone families remain unknown. Using whole-exome sequencing, we identified a rare variant that arose as a founder mutation in the telomere shelterin gene POT1 (chromosome 7, g.124493086C>T; p.Ser270Asn) in five unrelated melanoma-prone families from Romagna, Italy. Carriers of this variant had increased telomere lengths and numbers of fragile telomeres, suggesting that this variant perturbs telomere maintenance. Two additional rare POT1 variants were identified in all cases sequenced in two separate Italian families, one variant per family, yielding a frequency for POT1 variants comparable to that for CDKN2A mutations in this population. These variants were not found in public databases or in 2,038 genotyped Italian controls. We also identified two rare recurrent POT1 variants in US and French familial melanoma cases. Our findings suggest that POT1 is a major susceptibility gene for familial melanoma in several populations.

Positive margins in basal cell carcinoma: relationship to clinical features and recurrence risk. A retrospective study of 248 patients

Background Incomplete resection of a basal cell carcinoma does not necessarily imply tumour recurrence.

Common variants on 1p36 and 1q42 are associated with cutaneous basal cell carcinoma but not with melanoma or pigmentation traits

To search for new sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conducted a genome-wide SNP association study of 930 Icelanders with BCC and 33,117 controls. After analyzing 304,083 SNPs, we observed signals from loci at 1p36 and 1q42, and replicated these associations in additional sample sets from Iceland and Eastern Europe. Overall, the most significant signals were from rs7538876 on 1p36 (OR = 1.28, P = 4.4 × 10−12) and rs801114 on 1q42 (OR = 1.28, P = 5.9 × 10−12). The 1p36 locus contains the candidate genes PADI4, PADI6, RCC2 and ARHGEF10L, and the gene nearest to the 1q42 locus is the ras-homolog RHOU. Neither locus was associated with fair pigmentation traits that are known risk factors for BCC, and no risk was observed for melanoma. Approximately 1.6% of individuals of European ancestry are homozygous for both variants, and their estimated risk of BCC is 2.68 times that of noncarriers.

Prognostic factors in localized invasive cutaneous melanoma: high value of mitotic rate, vascular invasion and microscopic satellitosis.

The aim of this study was to determine independent clinical and pathological prognostic factors for overall and disease-free survival in Spanish melanoma patients. Eight hundred and twenty-three patients with localized melanoma and complete clinical and pathological information were evaluated. The age at diagnosis, gender, location, tumour thickness, invasion level, ulceration, histological subtype, inflammatory infiltrate, mitotic rate, vascular invasion, microscopic satellitosis, regression and cell type were all included. Univariate and multivariate Cox regression analyses were performed for overall and disease-free survival. Gender, histological subtype, tumour thickness, invasion level, ulceration, inflammatory infiltrate, microscopic satellitosis, vascular invasion and mitotic rate were related to overall and disease-free survival in univariate analysis. Age and location were only related to disease-free survival. Only tumour thickness, vascular invasion and gender exhibited independent significance for overall survival in multivariate analysis. For disease-free survival, tumour thickness, location, mitotic rate, vascular invasion and microscopic satellitosis were the sole independent factors. It can be concluded that the Breslow thickness remains the most significant prognostic factor for the survival of patients with localized cutaneous melanoma. Our results support the inclusion of microscopic satellitosis and vascular invasion in the current American Joint Committee on Cancer (AJCC) staging system, although further studies evaluating their separate influence are needed. Mitotic rate is confirmed as an objective and independent predictor of disease-free survival for melanoma patients that should be considered in further revisions of the mentioned staging system.

Telomerase reverse transcriptase promoter mutations in primary cutaneous melanoma.

We previously reported a disease segregating causal germline mutation in a melanoma family and recurrent somatic mutations in metastasized tumours from unrelated patients in the core promoter region of the telomerase reverse transcriptase (TERT) gene. Here we show that the TERT promoter mutations, besides causing an increased gene expression, associate with increased patient age, increased Breslow thickness and tumour ulceration in 287 primary melanomas. The mutations are more frequent at both intermittently and chronically sun-exposed sites than non-exposed sites and tend to co-occur with BRAF and CDKN2A alterations. The association with parameters generally connected with poor outcome, coupled with high recurrence and mechanistic relevance, raises the possibility of the eventual use of TERT promoter mutations in the disease management.