Truncating mutations of TP53AIP1 gene predispose to cutaneous melanoma

Genetic predisposition to cutaneous malignant melanoma (CMM) involves highly penetrant predisposing genes and low and intermediate penetrant predisposing alleles. However, the missing heritability in (CMM) is still high. For such and in order to identify new genetic factors for CMM, we conducted an exome sequencing study in high‐risk CMM patients. Two rounds of exome sequencing were successively performed in 33 and 27 high‐risk patients. We focused on genes carrying rare nonsense, frameshift, and splice variants (allelic frequency <1%) that were present in both series of exomes. An extension study was then conducted in a large cohort (1 079 CMM patients and 1 230 Caucasian ethnically matched healthy controls), and the inactivating variants frequency was compared between groups using two‐sided Fisher exact test. Two TP53AIP1 truncating mutations were identified in four patients: a frameshift c.63_64insG, p.Q22Afs*81 in two patients from the same family and in the proband of a second family; and a nonsense mutation c.95 C > A, p.Ser32Stop in a patient with multiple CMMs. In all patients, TP53AIP1 truncating variants were strongly associated with CMM risk (two‐sided Fisher exact test = 0.004, OR = 3.3[1.3‐8.5]). Additionally, we showed that TP53AIP1 mRNA was strongly down‐regulated throughout different phases of melanoma progression. TP53AIP1 gene is a TP53 target which plays a key role by inducting apoptosis in response to UV‐induced DNA damage. Constitutional mutations of TP53AIP1 had previously been involved in susceptibility to prostate cancer. Our results show that constitutional truncating TP53AIP1 mutations predispose to CMM in the French population. Replication studies in other populations should be performed.     

Genetic heterogeneity in familial malignant melanoma

Following reports of linkage to chromosome 9p In families withmalignant melanoma, we have been studying a series of UK families.Six families were selected with three or more cases of malignantmelanoma. We have used a total of twelve markers mapping Inthe Interval 9p13–p23 and constructed a set of haplotypesto study the Inheritance of the disease chromosome. Of the sixfamilies, three were consistent with linkage to the short armof 9, although their limited size precluded confirmation oflinkage. One family was clearly unlinked, one family was eitherunlinked, or contains a sporadic case, or delimits the locationof the melanoma gene, and one family was essentially unlnformative.This Is strong evidence for genetic heterogeneity In familieswith the malignant melanoma phenotype. We have also sequencedexon 2 of the recently identified candidate tumour suppressorgene, p16, in six Individuals and found no evidence for germlinemutations In this region of the p16 gene In our families withInherited malignant melanoma.     

ICAM-1 polymorphisms and development of cutaneous malignant melanoma

Tumour growth in cutaneous malignant melanoma (CMM) is mediated by cell adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1). ICAM-1 expression is associated with increasing Breslow thickness of vertical growth-phase tumours and, in patients with stage 1 disease, may be associated with disease free and patient survival. In this study we have investigated whether two single nucleotide polymorphisms (SNPs) in the ICAM-1 gene encoding amino acid substitutions in codons 241 and 469 of the expressed ICAM-1 molecule are associated with susceptibility to and markers of prognosis (including tumour Breslow thickness) in CMM. A total of 164 CMM patients and 264 cancer-free controls were genotyped for these SNPs by the 5' nuclease assay for allelic discrimination (TaqMan). No genotypes showed any significant associations with CMM susceptibility, although there was a non-significant increase in frequency of the ICAM-1 469 AA genotype among CMM patients vs. controls (38.4% vs. 29.9%; P = 0.11). However, the ICAM-1 241 GG genotype was significantly decreased in frequency among patients with primary invasive tumours of greater Breslow thickness (72.5% vs. 91.2%; P = 0.013; OR = 0.25 (0.072-0.85)). These results provide no evidence for a role for the ICAM-1 codon 241 and 469 SNPs in determining susceptibility to CMM, but provide preliminary evidence that the role of ICAM-1 polymorphism in modulating tumour growth in CMM requires further investigation in a larger study group.     

Ulceration and prognosis in cutaneous malignant melanoma

A review of 1818 patients with cutaneous malignant melanoma revealed that for both patients with localized disease (clinical stage I) and those with regional lymph node metastases at first presentation (clinical stage II), ulceration of the primary lesion was a poor prognostic sign. Although ulcerated lesions tended to be considerably thicker than non-ulcerated lesions, this factor did not entirely explain the poor prognosis recorded for patients with ulcerated lesions. In men and women matched by the thickness of their tumours, prognosis for those with ulcerated lesions was worse than for those with non-ulcerated lesions. This effect was particularly marked in women. It was concluded that since this histological feature was an independent prognostic determinant, it should be reported by the pathologist as a guide to the clinician in assessing prognosis in patients with melanoma.     

Prognostic factors in thin cutaneous malignant melanoma

An increasing number of thin (< or = 1 mm) cutaneous malignant melanomas are currently diagnosed. The majority of thin lesions is associated with an excellent prognosis, however, some of them may develop local recurrences and/or distant metastases with fatal outcome. Although Breslow thickness is the single most significant prognostic factor in melanoma in general, for thin lesions the identification of other morphological, biological and/or molecular parameters which may have an impact on neoplastic progression is mandatory. At present, Clark's levels and ulceration are regarded as significant prognostic factors. Further studies are needed to confirm the prognostic value of other histopathological parameters, including the evaluation of regression, inflammatory infiltrate and mitotic activity.     

Natural killer cells in cutaneous malignant melanoma

Using immunocytochemical techniques on fresh surgical samples, a series of 16 cases of cutaneous malignant melanoma (CMM) were examined to characterize further the host inflammatory response. Antibodies to the following cluster of differentiation (CD) antigens were used: CD-3, CD-4, CD-8 (T-cell markers), CD-11b, CD-14 (macrophage marker), CD-16 [an antigen expressed by natural killer (NK) cells and granulocytes], and CD-25. Also examined were a small number of other melanocytic lesions [two cases of lentigo maligna (Hutchinson's melanotic freckle) and five of intradermal naevi]. The results of the study document a population of cells with the morphological and immunophenotypic characteristics of NK cells in association with 10 of the 16 cases of CMM. These cells were consistently absent from the other melanocytic lesions studied. The presence of NK cells in association with some cases of CMM bears no clear relationship to the Breslow thickness, Clark level, tumour ulceration, or the presence of activated T cells as determined by expression of the CD-25 antigen. Whilst an explanation for the significant numbers of NK cells in some CMM lesions in unclear, their presence in intimate association with tumour cells does prompt speculation regarding a possible role in determining the biological behaviour of the tumour. Additionally, the study has confirmed and extended previous findings with respect to the broad characterization of mononuclear cells present in the host infiltrate associated with CMM.     

中性内肽酶及移动相关蛋白-1在恶性黑色素瘤中的表达及意义

目的探讨中性内肽酶（CD10）及移动相关蛋白-1（CD9）在恶性黑色素瘤中的表达及其临床意义。方法采用免疫组织化学SP法检测48例原发性皮肤恶性黑色素瘤（CMM）及23例转移性恶性黑色素瘤（转移性MM）中CD10、CD9蛋白表达水平,并以23例色素痣作为对照。结果（1）CD10在转移性MM、CMM及色素痣中的表达依次减弱,差异均有统计学意义（P〈0．01）,CD9在转移性MM中的表达较CMM显著降低（P〈0．05）;（2）CD9和CD10在恶性黑色素瘤中的表达水平呈负相关（CMM：r=-0.40,P=0.005;转移性MM：r=-0．44,P=0．034）;（3）CD10和CD9在CMM中的表达与病理学类型、淋巴结转移和浸润深度相关;（4）CD10、CD9在CMM间质成纤维细胞中的表达呈负相关（r=-0．43,P=0．007）,且与肿瘤浸润深度明显相关,与淋巴结转移有一定相关性。结论（1）CD10及CD9与恶性黑色素瘤的浸润、转移密切相关,两者在此过程中可能起相互拮抗作用;（2）肿瘤细胞CD10、CD9的表达对CMM的辅助诊断及预后评估具有重要的临床意义;（3）肿瘤间质成纤维细胞中CD10、CD9的表达在CMM的发展过程中亦可能扮演着重要角色。     

Myxoid variant of primary cutaneous malignant melanoma

We report a rare case of primary cutaneous myxoid melanoma. Histologically, the tumour was composed of spindle and stellate-shaped cells, embedded in a myxoid stroma. Positivity for S-100 protein and the presence of melanosomes were demonstrated in the tumour. Primary cutaneous myxoid melanoma is rare. This is the second report of such a case.     

Prognostic value of tumour thickness in cutaneous malignant melanoma

The relation between survival and histological features in 91 patients with malignant melanoma was studied and the results were analysed by Clayton's method for interpretation of censored survival data. There was a significant correlation between tumour thickness and survival. The risk of dying from malignant melanoma after 10 years of follow up was less than 15% if the primary tumour was less than 1·5 mm thick but more than 80% if the lesion was thicker than 8 mm.     

Mutations in CRLF1 cause familial achalasia

We here report a family from Libya with three siblings suffering from early onset achalasia born to healthy parents. We analyzed roughly 5000 disease‐associated genes by a next‐generation sequencing (NGS) approach. In the analyzed sibling we identified two heterozygous variants in CRLF1 (cytokine receptor‐like factor 1). Mutations in CRLF1 have been associated with autosomal recessive Crisponi or cold‐induced sweating syndrome type 1 (CS/CISS1), which among other symptoms also manifests with early onset feeding difficulties. Segregation analysis revealed compound heterozygosity for all affected siblings, while the unaffected mother carried the c.713dupC (p.Pro239Alafs*91) and the unaffected father carried the c.178T>A (p.Cys60Ser) variant. The c.713dupC variant has already been reported in affected CS/CISS1 patients, the pathogenicity of the c.178T>A variant was unclear. As reported previously for pathogenic CRLF1 variants, cytokine receptor‐like factor 1 protein secretion from cells transfected with the c.178T>A variant was severely impaired. From these results we conclude that one should consider a CRLF1‐related disorder in early onset achalasia even if other CS/CISS1 related symptoms are missing.     

The developmentally regulated neural crest-associated glycotope HNK-1 predicts metastasis in cutaneous malignant melanoma

Aberrant glycosylation is a common feature of metastatic sub-clones of malignant tumours and in uveal melanoma in particular, the HNK-1 glycotope has been positively correlated with poor prognosis. So far, no such correlation has been investigated in cutaneous melanoma. In order to do so, HNK-1 expression was evaluated immunohistochemically in 100 primary cutaneous melanomas and correlated with metastasis after up to 10-years' follow-up. Furthermore, HNK-1 expression was analysed in metastatic deposits (19 distant cutaneous metastases and six sentinel lymph node metastases), as well as in benign nevi. Kaplan-Meier analysis revealed a positive association between HNK-1 expression and metastasis (p < 0.005) and multivariate Cox regression analysis adjusted for the standard prognostic markers ulceration and vertical tumour thickness confirmed HNK-1 expression as an independent prognostic marker. HNK-1 expression was preserved in 42% of the distant cutaneous metastases, but metastatic cells in lymph nodes were devoid of HNK-1 immunoreactivity. None of the benign pigmented lesions exhibited HNK-1 immunoreactivity. Expression of the HNK-1 glycotope in cutaneous malignant melanoma is an independent prognostic marker of metastasis. Differential HNK-1 expression at the metastatic sites implies that its expression is modulated by the surrounding environment. As HNK-1 is also transiently expressed during migration of melanocyte precursor cells derived from the neural crest, recapitulation of this transient expression might occur during metastatic spread of cutaneous malignant melanoma.     

Expression and possible role of hPTTG1/securin in cutaneous malignant melanoma.

Human pituitary tumour-transforming gene 1 or hPTTG1 is a proto-oncogene that codes for securin, a protein involved in sister chromatid separation. Based on previous microarray data, we studied the expression of hPTTG1/securin in melanocytic lesions. In contrast to nevi and radial growth phase melanomas, securin was expressed by scattered cells in the vertical growth phase, suggesting a role in tumour progression. In a series of 29 nodular and 29 superficial spreading melanomas, matched for all histological prognostic parameters, securin expression was significantly correlated with the nodular subtype (P=0.018) and not related to thickness. In other cancers, hPTTG1 is involved in various oncogenic pathways, including induction of neovascularisation and aneuploidy, and inhibition of p53 activity. We found coexpression of securin with wild-type p53 in the same neoplastic cells in a minority of melanomas. Expression of securin was significantly correlated with the extent of aneuploidy but not with basic fibroblast growth factor immunoreactivity or microvessel density. DNA cytometry revealed that nuclei-overexpressing securin frequently showed tetraploidy or aneuploidy. Our data show that hPTTG1 is frequently overexpressed in nodular melanoma, and suggest that hPTTG1 may act as an oncogene in the vertical growth phase, either by inhibiting anaphase, thereby causing aneuploidy and genomic instability, or by modulating the function of p53, thereby impairing apoptosis.     

Malignant peripheral nerve sheath tumour-like primary cutaneous malignant melanoma

Malignant melanoma is known for its protean cytomorphological features, architectural patterns, and stromal changes, in addition to its ability to mimic various benign and malignant non-melanocytic tumours. Anecdotal cases of metastatic malignant melanoma simulating soft tissue sarcomas have been reported. Interestingly, this mimicry is more often seen in recurrent lesions and metastatic deposits. This report describes a case of a primary spindle cell cutaneous malignant melanoma with a prominent neural-like fascicular pattern and nuclear palisading, simulating a conventional malignant peripheral nerve sheath tumour (MPNST). Clinical, microscopic, and immunohistochemical features of the different entities included in the differential diagnosis of cutaneous spindle cell malignant tumours, such as MPNST, atypical fibroxanthoma, and spindle cell squamous cell carcinoma are discussed. Of note, the presence of an atypical epidermal or junctional component, cell pigmentation, and cell nesting, in addition to diffuse and strong reactivity for S-100 protein and other melanocytic markers, are helpful in the diagnosis of these troublesome lesions.     

Sister chromatid exchange analysis in familial groups of malignant melanoma patients

Sister chromatid exchange (SCE) analysis was carried out on peripheral blood lymphocytes of 20 familial malignant melanoma (FMM) and 39 sporadic malignant melanoma (SMM) untreated patients, belonging to 10 and 39 families, respectively. The study was extended to 39 unaffected close relatives of FMM patients, to 187 unaffected close relatives of SMM patients, and to 20 unaffected unrelated individuals (control group), all examined under the same conditions. The mean SCE rates/cell were significantly higher in MM families than in the control group, and in melanoma patients than in their close relatives. The mean SCE levels of FMM and SMM patients, (8.4 +/- 0.8 and 8.0 +/- 0.3, respectively) were similar, and so were the distributions of individuals in classes of increasing SCE values (with a modal value at 7-8 SCEs/cell). The mean SCE levels of close relatives of FMM and SMM patients were also similar (5.4 +/- 0.2 and 5.4 +/- 0.1, respectively, with a modal value at 4-5 SCEs/cell), and slightly higher than in the control group (4.7 +/- 0.2 SCEs/cell). More than 7 SCEs/cell were observed in the majority (41 of 59) of FMM or SMM patients, in a smaller fraction (25 of 227) unaffected relatives, and in none of 20 unrelated unaffected individuals. These observations favor the hypothesis that higher SCE levels may be an expression of constitutional lesions predisposing to this neoplastic disease.     

Cytokine gene single nucleotide polymorphisms and susceptibility to and prognosis in cutaneous malignant melanoma

Cutaneous malignant melanoma (CMM) is a potentially fatal malignancy in which exposure to UV light is the most important risk factor. Several lines of evidence suggest that CMM patients develop an immune response to their tumours, although, in most cases, anti‐tumour immune responses are insufficient to abrogate tumour development. Polymorphism in genes regulating the immune response and cell growth may result in increased susceptibility to and/or poorer prognosis in certain individuals. In this study, we addressed whether single nucleotide polymorphisms (SNPs) associated with differential expression of selected pro‐ and anti‐inflammatory cytokines and growth factors [interleukin (IL)‐1β?35 and ?511, IL‐2 ?330, IL‐4 ?590, IL‐6 ?174, IL‐8 ?251, interferon (IFN)‐γ+874 and transforming growth factor (TGF)β1 +915] or as markers of candidate cytokine genes (IL‐12 +1188) are associated with susceptibility to or known prognostic indicators (e.g. initial tumour growth phase, Breslow thickness, mitotic count in vertical growth phase tumours, tumour regression) in CMM. One hundred and sixty‐nine British caucasian CMM patients and 261 controls were included in the study and all SNPs were genotyped by ARMS–PCR. No SNP genotypes or alleles showed significant associations with CMM susceptibility and only the IL‐1β?511 TT genotype was associated with thinner invasive tumours at presentation, as assessed by Breslow thickness at the clinically significant cut‐off point of 1.5 mm [occurring in 2/51 (3.9%) thicker vs. 14/78 (17.9%) thinner tumours (P = 0.03; relative risk = 0.29 (95% confidence interval 0.05–0.95)]. These findings suggest that — with the possible exception of IL‐1β— genetic variation associated with differential expression of the selected pro‐ and anti‐inflammatory cytokines is unlikely to play a major role in susceptibility to and prognosis in CMM.