Genomic Stability in Syndromic Basal Cell Carcinoma.

Basal cell cancers (BCCs) are characterized by upregulation of Hedgehog pathway through loss of PTCH1 or activation of SMO, and SMO inhibitors, such as vismodegib, are effective therapies for advanced BCCs. Although most BCCs are sporadic, rare individuals with basal cell nevus syndrome (BCNS) harbor germline defects in PTCH1 and develop up to hundreds of tumors that are histopathologically indistinguishable from sporadic BCCs. Interestingly, BCNS-BCCs are more responsive to SMO inhibitors than sporadic BCCs, with minimal development of resistance. Given differences in clinical course and therapy response, we sought to characterize BCCs in the setting of BCNS. We found that BCNS individuals with low tumor burden demonstrated significantly fewer UV signature somatic mutations and lower overall somatic mutational load compared to BCNS individuals with high burden, supporting a role of UV exposure in driving BCC development in BCNS individuals. However, compared with sporadic BCCs, BCNS-BCCs have a significantly lower mutational load, lower proportion of UV mutagenesis, increased genomic stability, and harbor fewer functionally resistant SMO mutations at baseline, explaining why BCNS-BCCs lack intrinsic resistance to SMO inhibitors. BCNS-BCCs appear to have reduced mutator phenotype compared with sporadic BCCs, which may contribute to their relatively more indolent clinical course and responsiveness to therapy.

Very Long-term Sequelae After Nonradical Surgery Combined With Brachytherapy in an Infant With a Chemotherapy-resistant Rhabdomyosarcoma of the Tongue.

In 2003, van Grotel and colleagues reported an infant suffering a chemotherapy-resistant eRMS of the tongue, that was treated with subtotal tumor resection and brachytherapy after major medical ethical discussions. As no long-term sequelae of such a procedure have been described, perspectives were uncertain at that time. Now, after 15 years, we describe hypoplasia of the mandibula, compromised dentation, osteopenia, neuropsychological deficits, and moderate speech impairment as the most prominent late effects. Also, mandibular cysts and basal cell carcinomas in the irradiated area, eventually led to the diagnosis Gorlin syndrome.

Gorlin-Goltz syndrome: case report and review of literature

Description of a case report of Gorlin-Goltz Syndrome diagnosed in a male newborn who presented increased head circumference and bifid ribs. Mother and grandmother presented typical physical findings of the syndrome, including palmar pits, odontogenic cysts, and history of multiple skin cancer resections. The diagnosis was based on clinical findings of three relatives. A literature review is also presented.

[Pediatric keratocystic odontogenic tumor and nevoid basal cell carcinoma syndrome. Predictive factors for recurrence and aggressiveness]. / Tumeurs kératokystiques odontogènes de l'enfant et syndrome de Gorlin. Comment expliquer les récidives et l'agressivité des lésions ?

INTRODUCTION: Keratocystic odontogenic tumors (KOT), as complications in Nevoid Basal Cell Carcinoma Syndrome (NBCCS), occur early (before 20 years of age) and are usually more aggressive. The aim of this retrospective study was to determine the clinical, histological, and genetic phenotype, of these lesions and to define predictive features of aggressiveness. PATIENTS AND METHODS: We retrospectively studied five patients presenting with one or several KOT with NBCCS. We collected their clinical, radiological, and therapeutic data, rate of recurrence or new localization. Anatomopathological examinations were reviewed systematically. Somatic PTCH, SMO and SMAD 4 sequencing were completed. RESULTS: The average age at diagnosis was 11.2 years. The average number of KOT was 3.2 most often located in the molar region. All the cysts were enucleated. Anatomopathological examination revealed the presence of satellite cysts and daughter cysts and epithelial expansion in more than 80% of cases. No somatic mutation was observed among KOT. DISCUSSION: KOT develop in the first 10 years, in patients presenting with NBCCS, and recurrence is observed in the second and third decade. KOT are typically aggressive and have a tendency to recur, especially in patients with NBCCS. Anatomopathological examination may be predictive of the lesion's aggressiveness. Understanding the genetic and immunological mechanisms should open the way for new medical treatment.

Basal cell nevus syndrome.

PURPOSE OF REVIEW: Basal cell nevus syndrome (BCNS), is a hereditary condition transmitted as an autosomal dominant trait exhibiting high penetrance and variable expressivity. Inherited or spontaneous mutations in the human homologue of the Drosophila patched gene underlie the disorder and in addition to tumor predisposition, are associated with a range of 'patterning' defects. Recent advances, with glimpses of possible therapies are emerging, but because of the wide-ranging nature of phenotypic expression and overlap with other syndromes, there is difficulty. Finally, because of the importance of PTCH and paralogous genes in many species other than humans, reports appear in a correspondingly wide range of journals, which makes 'keeping abreast' difficult. RECENT FINDINGS: Progress has been achieved in understanding the role of Gli-1, 2, & 3 in development of 'sporadic' BCCs and BCNS. Expression of PTCH1 is now known to be regulated by alternative promoters and a single functional Gli-binding site. Expression of FOXE1 as a new transcriptional target of Gli2 has been demonstrated in human epidermis and BCCs. Finally, the discovery of Shh pathway inhibitors such as cyclopamine, a naturally occurring alkaloid and ornithine decarboxylase inhibition suggest possible interventional therapies. SUMMARY: In BCNS, phenotype does not correlate with position of mutations within Patched, suggesting genetic makeup and environment modulate effects of premature protein truncation induced by PTCH mutation. These developmental abnormalities occur as a result of haplo-insufficiency in heterozygotes for the mutated gene, whereas neoplastic complications arise from a classical two-hit tumor suppressor gene model. Attention is therefore turning toward TP53 and PTCH associations.

Síndrome de Gorlin-Goltz. Síndrome del nevo baso-celular / Gorlin-Goltz syndrome. Basal cell nevus syndrome

Los autores describen los síntomas clínicos en tres sujetos de la misma familia, afectados por el síndrome del nevo basocelular. Se enfatiza la importancia de su conocimiento por parte del odontólogo, ya que su diagnóstico se puede establecer en base a los queratoquistes odontogénicos, sus características faciales, óseas y dermatológicas presentes en estos pacientes

Several PATCHED1 missense mutations display activity in patched1-deficient fibroblasts.

Mutations in mouse and human patched1 (ptc1) genes are associated with birth defects and cancer. Ptc1 is a receptor for Hedgehog (Hh) signaling proteins. Hh proteins activate transcription of target genes, including ptc1, and Ptc1 represses those genes, both by regulating the activity of Gli transcription factors. We have established mammalian cell lines with reduced Ptc1 function and a lacZ reporter to investigate Hh signal transduction. Embryonic fibroblasts were derived from mice, heterozygous or homozygous for a ptc1 mutation that inserts lacZ under the control of the ptc1 promoter (ptc1-lacZ). In heterozygous ptc1 cells, ptc1-lacZ was expressed at low levels but could be induced by Sonic Hedgehog (Shh) and Gli-1. Homozygous ptc1 cells expressed high levels of ptc1-lacZ without Hh stimulation. ptc1-lacZ expression was dependent on cell density in ptc1 homozygotes and Hh-stimulated heterozygotes but was independent of density when Gli1 was used to activate ptc1-lacZ. A wild-type ptc1 transgene introduced into homozygous ptc1 cells greatly reduced ptc1-lacZ expression. Expression of either half of Ptc1 alone resulted in improper maturation of the protein and a failure to complement the ptc1(-/-) cells. When co-expressed, both Ptc1 halves matured and had an activity similar to that of the intact protein. Three missense PTCH1 mutations exhibited significant functions in homozygous ptc1 cells. The missense mutants retained activity when expressed at about 10-fold lower levels and appeared as stable as wild-type Ptc1. These studies suggest that some tumors and disease phenotypes may arise from small reductions in PTCH1 activity.

Multiple synchronous pigmented basal cell carcinomas following radiotherapy for Hodgkin's disease.

BACKGROUND: Multiple basal cell carcinomas (BCCs) are infrequently seen in patients under 30 years of age. Their occurrence at a young age is often linked to some genodermatosis, including Nevoid Basal Cell Carcinoma Syndrome (NBCCS). The exposure to ionizing radiation is also considered to be a predisposing factor in the development of BCCs. METHODS: We report the case of a 35-year-old patient who presented with seven synchronous, nodular, brownish-pigmented BCCs, confined within the radiation-treated cutaneous areas, 15 years after receiving Cobalt-60 (60Co) irradiation for Hodgkin's disease. RESULTS: On the basis of clinical, radiological, and anamnestic data we excluded a NBCCS, thus proposing irradiation as the cause of the multiple synchronous pigmented BCCs. CONCLUSIONS: Previous therapeutic ionizing radiation leads to an increased risk of BCCs confined to the region of the body to which radiotherapy was delivered. We consider our patient's BCCs represents a late adverse effect of the treatment with Cobalt-60.

Síndrome del nevo basocelular / Nevoid basal-cell syndrome

Los autores presentamos un enfoque clínico descriptivo del síndrome del nevo basocelular, incluyendo nuestra experiencia en dos casos clínicos de diferente sexo, detallando estudios radiográficos y técnicas quirúrgicas realizadas

Human developmental disorders and the Sonic hedgehog pathway.

Sonic hedgehog (Shh) is a morphogen that is crucial for normal development of a variety of organ systems, including the brain and spinal cord, the eye, craniofacial structures, and the limbs. Mutations in the human SHH gene and genes that encode its downstream intracellular signaling pathway cause several clinical disorders. These include holoprosencephaly (HPE, the most common anomaly of the developing forebrain), nevoid basal cell carcinoma syndrome, sporadic tumors, including basal cell carcinomas, and three distinct congenital disorders: Greig syndrome Pallister-Hall syndrome, and isolated postaxial polydactyly. These conditions caused by abnormalities in the SHH pathway demonstrate the crucial role of SHH in complex developmental processes, and molecular analyses of these disorders provide insight into the normal function of the SHH pathway in human development.

Developmental genes and cancer: role of patched in basal cell carcinoma of the skin.

Many genes originally identified because of their role in embryonic development are also important in postnatal control of cell growth and differentiation. Mutations in some of these genes have been shown to cause cancer. Basal cell carcinoma (BCC) of the skin is the most common cancer in humans. More than 750000 new cases are diagnosed annually, and the incidence is rising. BCCs are slow-growing, locally invasive tumors that rarely metastasize but can result in extensive morbidity through local recurrence and tissue destruction. Epidemiologic studies suggest that sunlight (particularly UVB radiation) is a strong risk factor for BCC formation, although other factors are also involved. The nevoid basal cell carcinoma syndrome (NBCCS), a rare genetic disorder, is characterized by predisposition to BCCs and other tumors as well as to a wide range of developmental defects. NBCCS maps to chromosome 9q22.3, and loss of heterozygosity at this site in both sporadic and hereditary BCCs suggests that it functions as a tumor suppressor. The gene for NBCCS was recently cloned and is the human homologue of the Drosophila gene "patched." Genetic studies in Drosophila show that patched is part of the hedgehog signaling pathway, which is important in determining embryonic patterning and cell fate in multiple structures of the developing embryo. Human patched is mutated in both hereditary and sporadic BCCs, and inactivation of this gene is probably a necessary, if not sufficient, step for BCC formation. Delineation of the biochemical pathway in which patched functions may lead to rational medical therapy for BCCs and possibly for other tumors associated with NBCCS.

Multiple neoplasms following craniospinal irradiation for medulloblastoma in a patient with nevoid basal cell carcinoma syndrome. Case report.

A 28-year-old man presented to the authors' hospital with multiple intracranial tumors. At 2 years of age, he had undergone resection of a medulloblastoma and received adjunctive craniospinal irradiation. Subsequently, he was diagnosed with nevoid basal cell carcinoma syndrome, Gorlin's syndrome. Since his first presentation, he has required surgery for multiple basal cell carcinomas, an osteochondroma of the rib, two meningiomas, a trigeminal schwannoma, and a pleomorphic liposarcoma, all of which arose within the radiation field. Despite this impressive list of benign and malignant neoplasms, the patient is relatively well and leads a normal life. The authors examine the relationships between Gorlin's syndrome and radiation therapy and the subsequent development of tumors.

Rearrangement of the same chromosome regions in different SV40 transformed human skin keratinocyte lines is associated with tumourigenicity.

Twelve different human keratinocyte strains were transformed with recombinant plasmid pSV6-1 which contained an origin defective SV40 genome. When injected into athymic nude mice lines produced either squamous cell carcinomas (SCC) in all animals, SCC in some animals and epidermal cysts in others, or epidermal cysts only in all the animals. The tumourigenic capacity of the lines could be correlated with the chromosomal changes present initially in the transformed cells. Lines which produced SCC in all the animals within a short period of time all showed simultaneous loss of part of chromosomes 3p, 8p and 11p in one homologue. Lines which were not tumourigenic did not show these simultaneously appearing rearrangements. These specific rearrangements are acquired in vitro and the time taken for a recognisable tumour to appear is related to the proportion of such cells in the line. The rearrangement of the same chromosome regions in different tumourigenic cell lines suggests that genes in these regions are important in the development of squamous cell carcinoma, possibly by loss of heterozygosity, at particular loci.

Síndrome de Gorlin-Goltz: relato de um caso / Gorlin-Goltz syndrome: a case report

Os autores fazem uma revisäo da literatura, observando o interesse desta síndrome tanto para o odontológico, quanto para o médico, dissertando sobre várias características clínicas da mesma. Relatam um caso clínico em que trataram de uma criança de 11 anos de idade