Publications by authors named "Ashton-Prolla P"

Germline TP53 pathogenic variants can lead to a cancer susceptibility syndrome known as Li-Fraumeni (LFS). Variants affecting its activity can drive tumorigenesis altering p53 pathways and their identification is crucial for assessing individual risk. This study explored the functional impact of TP53 missense variants on its transcription factor activity.

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International differences in the incidence of many cancer types indicate the existence of carcinogen exposures that have not yet been identified by conventional epidemiology make a substantial contribution to cancer burden. In clear cell renal cell carcinoma, obesity, hypertension and tobacco smoking are risk factors, but they do not explain the geographical variation in its incidence. Underlying causes can be inferred by sequencing the genomes of cancers from populations with different incidence rates and detecting differences in patterns of somatic mutations.

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Article Synopsis
  • Tumor suppressor p53 (TP53) mutations in cancer lead to loss of its protective function and potential gain of oncogenic traits, with mutant forms often stabilized in tumors.
  • Researchers conducted CRISPR screens to identify factors that regulate the stability of wild-type and mutant p53, revealing that most regulators affect both, but some, like those for mutant p53 R337H, are specific to that mutant.
  • The study highlights FBXO42 as a positive regulator for certain p53 mutants and C16orf72/HAPSTR1 as a negative regulator linked to increased levels in breast cancer, suggesting potential targets for cancer therapy focused on p53 stability.
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Introduction: Cancer Genetic Counseling (CGC) and genetic testing (GT) assume a paramount role for hereditary cancer predisposition syndrome families. We assessed the effects of CGC and GT on women affected by cancer who are at risk for hereditary breast and ovarian cancer predisposition syndrome (HBOC).

Methods: This study encompasses four time points: before the CGC session, after the CGC session when blood is drawn for GT, after disclosure of GT results, and six months following disclosure of GT results.

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Tuberous Sclerosis Complex (TSC) is caused by loss of function germline variants in the TSC1 or TSC2 tumor suppressor genes. Genetic testing for the detection of pathogenic variants in either TSC1 or TSC2 was implemented as a diagnostic criterion for TSC. However, TSC molecular diagnosis can be challenging due to the absence of variant hotspots and the high number of variants described.

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Large-scale biorepositories and databases are essential to generate equitable, effective, and sustainable advances in cancer prevention, early detection, cancer therapy, cancer care, and surveillance. The Mutographs project has created a large genomic dataset and biorepository of over 7,800 cancer cases from 30 countries across five continents with extensive demographic, lifestyle, environmental, and clinical information. Whole-genome sequencing is being finalized for over 4,000 cases, with the primary goal of understanding the causes of cancer at eight anatomic sites.

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  • * In a study examining Brazilian patients with lung adenocarcinoma, sarcoma, and uterine leiomyoma, the minor allele (C) of this variant was found in only 1.02% of LUAD cases, while none were detected in SARC or ULM samples.
  • * Although the prevalence of rs78378222 is low in the specific tumors studied, the findings suggest that further analysis in Brazilian regions is not necessary, but molecular testing for this variant should still be considered in other populations.
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Introduction: Next-generation sequencing (NGS) of Formalin-Fixed and Paraffin-Embedded (FFPE) specimens is routine in precision oncology practice. However, results are not always conclusive, and it is important to identify which factors may influence FFPE tumor sequencing success.

Materials And Methods: Here, we evaluated the influence of pre-analytical factors on 705 samples of non-small cell lung cancer specimens that underwent NGS testing.

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Purpose: Li-Fraumeni Syndrome (LFS) is a rare cancer predisposing condition caused by germline pathogenic TP53 variants, in which core tumors comprise sarcomas, breast, brain and adrenocortical neoplasms. Clinical manifestations are highly variable in carriers of the Brazilian germline founder variant TP53 p.R337H, possibly due to the influence of modifier genes such as miRNA genes involved in the regulation of the p53 pathway.

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Purpose: To evaluate cancer risk factors among cancer cases and controls from Southern Brazil, to analyze a multigene hereditary panel testing (MGPT, 26 genes) for breast cancer (BC) and colorectal cancer (CCR) cases diagnosed age younger than 50 years and to characterize them for hereditary cancer syndrome (HCS) phenotypes.

Methods: A case-control (matched by age group and sex) study was conducted on regional cancer. Data on exposure factors and first-/second-degree family history of cancer (1/2FHC) were collected.

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The coronavirus disease 2019 (COVID-19) mortality rates varied among the states of Brazil during the course of the pandemics. The human leukocyte antigen (HLA) is a critical component of the antigen presentation pathway. Individuals with different HLA genotypes may trigger different immune responses against pathogens, which could culminate in different COVID-19 responses.

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Article Synopsis
  • This study investigates the genetic factors contributing to inherited lung cancer, focusing on families with germline pathogenic variants (PVs).
  • Over a 5-year period, 141 participants with lung cancer and their relatives were enrolled, revealing a significant Mendelian inheritance pattern of the T790M variant with varied cancer penetrance.
  • The findings highlight a recent common ancestor for the T790M variant primarily found in the southeastern U.S., suggesting the need for targeted screening in at-risk families, as many carriers showed high occurrences of lung cancer and related health issues.
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MUTYH-associated polyposis syndrome is an uncommon, autosomal recessive colorectal polyposis syndrome caused by biallelic inactivation of . Most patients present with multiple colorectal polyps. However, other primary tumor sites have been described as less frequent.

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One of the main factors that attracts authors to choose a journal is the time interval between submission and publication, which varies between journals and subject matter. Here, we evaluated the time intervals between submission and publication according to journal impact factor and continent of author's affiliation, considering articles with authors from single or multiple continents. Altogether, 72 journals indexed in the Web of Science database within the subject matter "Genetics and Heredity", divided by impact factor into four quartiles and randomly selected were analyzed for time intervals from article submission to publication.

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Genetic and epigenetic alterations of the telomere maintenance machinery like telomere length and telomerase reverse transcriptase (encoded by TERT gene) are reported in several human malignancies. However, there is limited knowledge on the status of the telomere machinery in periampullary carcinomas (PAC) which are rare and heterogeneous groups of cancers arising from different anatomic sites around the ampulla of Vater. In the current study, we investigated the relative telomere length (RTL) and the most frequent genetic and epigenetic alterations in the TERT promoter in PAC and compared it with tumor-adjacent nonpathological duodenum (NDu).

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Article Synopsis
  • The correct interpretation of germline variants from gene testing is crucial for effective cancer genetic counseling, especially regarding variants of uncertain significance (VUS) that need frequent re-evaluation.
  • In a study analyzing BRCA1/2 VUS from Brazil, two out of fifteen variants were reclassified as likely pathogenic by all three major classification guidelines (ACMG, Sherloc, ENIGMA), highlighting ongoing challenges in variant reassessment.
  • Establishing a clear framework for VUS re-evaluation and involving a multidisciplinary team in monitoring data can enhance clinical practices and improve outcomes for patients.
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Retinoblastoma is a rare childhood tumor caused by the inactivation of both copies of the RB1 gene. Early diagnosis and identification of heritable RB1 mutation carriers can improve the disease outcome and management via genetic counseling. We used the Multiplex Ligation-dependent Probe Amplification (MLPA) method to analyze the RB1 gene and flanking regions in blood samples from 159 retinoblastoma patients previously negative for RB1 point mutations via Sanger sequencing.

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Purpose: To report on pathogenic germline variants detected among individuals undergoing genetic testing for hereditary breast and/or ovarian cancer (HBOC) from Latin America and compare them with self-reported Hispanic individuals from the United States.

Methods: In this cross-sectional study, unrelated individuals with a personal/family history suggestive of HBOC who received clinician-ordered germline multigene sequencing were grouped according to the location of the ordering physician: group A, Mexico, Central America, and the Caribbean; group B, South America; and group C, United States with individuals who self-reported Hispanic ethnicity. Relatives who underwent cascade testing were analyzed separately.

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Background: Risk-reducing operations are an important part of the management of hereditary predisposition to cancer. In selected cases, they can considerably reduce the morbidity and mortality associated with cancer in this population.

Objectives: The Brazilian Society of Surgical Oncology (BSSO) developed this guideline to establish national benchmarks for cancer risk-reducing operations.

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Article Synopsis
  • Risk-reducing surgeries are key for managing hereditary cancer risks, significantly lowering the associated health issues and mortality.
  • The Brazilian Society of Surgical Oncology developed guidelines to provide national standards for these surgical procedures.
  • A team of experts reviewed literature and conducted discussions to create recommendations, achieving consensus on various risk-reduction surgeries like mastectomy and hysterectomy.
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Introduction: Hereditary cancer predisposition syndromes are caused by germline pathogenic or likely pathogenic variants in cancer predisposition genes (CPG). The majority of pathogenic variants in CPGs are point mutations, but large gene rearrangements (LGRs) are present in several CPGs. LGRs can be much more difficult to characterize and perhaps they may have been neglected in molecular diagnoses.

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Tuberous sclerosis complex (TSC) is an autosomal dominant cancer predisposition disorder caused by heterozygous mutations in TSC1 or TSC2 genes and characterized by mTORC1 hyperactivation. TSC-associated tumors develop after loss of heterozygosity mutations and their treatment involves the use of mTORC1 inhibitors. We aimed to evaluate cellular processes regulated by mTORC1 in TSC cells with different mutations before tumor development.

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Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition syndrome caused by pathogenic germline variants in the TP53 gene, characterized by a predisposition to the development of a broad spectrum of tumors at an early age. The core tumors related to LFS are bone and soft tissue sarcomas, premenopausal breast cancer, brain tumors, adrenocortical carcinomas (ACC), and leukemias. The revised Chompret criteria has been widely used to establish clinical suspicion and support TP53 germline variant testing and LFS diagnosis.

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The prevalence and contribution of BRCA1/2 (BRCA) pathogenic variants (PVs) to the cancer burden in Latin America are not well understood. This study aims to address this disparity. BRCA analyses were performed on prospectively enrolled Latin American Clinical Cancer Genomics Community Research Network participants via a combination of methods: a Hispanic Mutation Panel (HISPANEL) on MassARRAY; semiconductor sequencing; and copy number variant (CNV) detection.

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