Characterization of Potential Melanoma Predisposition Genes in High-Risk Brazilian Patients.

Increased genetic risk for melanoma can occur in the context of germline pathogenic variants in high-penetrance genes, such as and , risk variants in low- to moderate-penetrance genes ( and ), and possibly due to variants in emerging genes, such as , and . We aimed to identify germline variants in high- and low- to moderate-penetrance melanoma risk genes in Brazilian patients with clinical criteria for familial melanoma syndrome. We selected patients with three or more melanomas or melanoma patients from families with three tumors (melanoma and pancreatic cancer) in first- or second-degree relatives.

Hereditary melanoma: a five-year study of Brazilian patients in a cancer referral center - phenotypic characteristics of probands and pathological features of primary tumors.

Background: Approximately five to 10% of all melanomas occur in families with hereditary predisposition and the main high-risk melanoma susceptibility gene is the CDKN2A.

Objectives: To describe, after a five-years study, the clinical data of patients (probands) from familial melanoma kindreds, and the pathological characteristics of their melanoma.

Methods: The inclusion criteria were melanoma patients with a family history of melanoma or pancreatic cancer (first- or second-degree relatives) or patients with multiple primary melanomas (MPM).

DNA methylation landscape of hepatoblastomas reveals arrest at early stages of liver differentiation and cancer-related alterations.

Hepatoblastomas are uncommon embryonal liver tumors accounting for approximately 80% of childhood hepatic cancer. We hypothesized that epigenetic changes, including DNA methylation, could be relevant to hepatoblastoma onset. The methylomes of eight matched hepatoblastomas and non-tumoral liver tissues were characterized, and data were validated in an independent group (11 hepatoblastomas).

Genome-wide DNA methylation profile of leukocytes from melanoma patients with and without CDKN2A mutations.

Melanoma is a highly aggressive cancer, accounting for up to 75% of skin cancer deaths. A small proportion of melanoma cases can be ascribed to the presence of highly penetrant germline mutations, and approximately 40% of hereditary melanoma cases are caused by CDKN2A mutations. The current study sought to investigate whether the presence of germline CDKN2A mutations or the occurrence of cutaneous melanoma would result in constitutive genome-wide DNA methylation changes.

Large germline copy number variations as predisposing factor in childhood neoplasms.

Aims: Constitutive genetic factors are believed to predispose to cancer in children. This study investigated the role of rare germline copy number variations (CNVs) in pediatric cancer predisposition.

Patients & Methods: A total of 54 patients who developed cancer in infancy were screened by array-CGH for germline CNVs.

Establishment of new lines of human embryonic stem cells: evolution of the methodology.

Although since 1998 more than 1,200 different hESC lines have been established worldwide, there is still a recognized interest in the establishment of new lines of hESC, particularly from HLA types and ethnic groups underrepresented among the currently available lines. The methodology of hESC derivation has evolved significantly since the initial derivations using human LIF (hLIF) for maintenance of pluripotency. However, there are still a number of alternative strategies for the different steps involved in establishing a new line of hESC.

A survey of parameters involved in the establishment of new lines of human embryonic stem cells.

Since the derivation of the first human embryonic stem cell (hESC) lines by Thomson and coworkers in 1998, more than 1,200 different hESC lines have been established worldwide. Nevertheless, there is still a recognized interest in the establishment of new lines of hESC, particularly from HLA types and ethnic groups currently underrepresented among the available lines. The methodology of hESC derivation has evolved significantly since 1998, when human LIF (hLIF) was used for maintenance of pluripotency.

Random X inactivation and extensive mosaicism in human placenta revealed by analysis of allele-specific gene expression along the X chromosome.

Imprinted inactivation of the paternal X chromosome in marsupials is the primordial mechanism of dosage compensation for X-linked genes between females and males in Therians. In Eutherian mammals, X chromosome inactivation (XCI) evolved into a random process in cells from the embryo proper, where either the maternal or paternal X can be inactivated. However, species like mouse and bovine maintained imprinted XCI exclusively in extraembryonic tissues.