Searching for mutations in the HNF1B gene in a Brazilian cohort with renal cysts and hyperglycemia

ABSTRACT Objective To verify the presence of variants in HNF1B in a sample of the Brazilian population selected according to the presence of renal cysts associated with hyperglycemia. Subjects and methods We evaluated 28 unrelated patients with clinical suspicion of HNF1B mutation because of the concomitant presence of diabetes mellitus (DM) or prediabetes and renal cysts. Genotyping was accomplished using Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). In positive cases, available relatives were recruited. Results We found two patients with HNF1B mutations. The first presented the variant p.Pro328Leufs*48(c.983delC) and had DM, renal cysts, and hypomagnesemia. The second presented a heterozygous whole gene deletion in HNF1B, DM, renal cysts, body and tail pancreatic agenesis, and hypomagnesemia; this alteration was also found in his two siblings and his father. Conclusion The recruitment of suspected cases of HNF1B gene mutations in Brazilians due to hyperglycemia and renal cysts presents two positive cases. Our cases contribute to the annotation of clinical and biochemical phenotypes of this rare form of maturity-onset diabetes of the young (MODY).

Clonagem molecular do oncogene EZH2 de leucemiamieloide crônica e perspectivas terapêuticas / Molecular cloning of EZH2 oncogene in chronic myeloid leukemia andtherapeutic prospects

A Leucemia Mieloide Crônica (LMC) é uma neoplasia mieloproliferativa originada, em 95% dos casos, por uma anormalidadecitogenética que se caracteriza pela translocação recíproca entre os cromossomos 9 e 22 t(9; 22) (q34; q11), resultandono cromossomo Philadelphia (Ph). Considerando que a cura da LMC só é possível com um transplante de medulaóssea bem-sucedido e que existem casos de resistência ao inibidor de tirosina quinase Mesilato de Imatinibe, fármacode primeira escolha para o tratamento, é importante que se conheça detalhadamente os genes e proteínas alterados naLMC, favorecendo a efetividade de estratégias terapêuticas, a otimização do diagnóstico e a detecção de doença residualmínima. Dentre as novas abordagens terapêuticas para a LMC está a terapia gênica, que dependendo do gene alvo, podetambém ser eficiente para o tratamento de outras neoplasias. Dentro deste contexto, os objetivos do trabalho foram:realizar a clonagem molecular de um fragmento de DNA do gene EZH2, alvo promissor da terapia gênica, que provocaalteração epigenética na LMC e em diversas neoplasias; bem como contribuir para outros trabalhos de manipulação gênicainterespécies, os quais tem grande contribuição para a área da saúde. Para isso, o gene EZH2 foi isolado a partir do DNAgenômico de sangue periférico de pacientes com LMC e posteriormente clonado em sistemas procariotos. Dessa forma,foram realizados, definidos e comprovados os procedimentos de manipulação gênica interespécies e discutido o futuro dabiotecnologia no auxílio a pesquisas e a tratamentos, com foco na LMC.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasia, caused in 95 % of the cases by a cytogenetic abnormalitycharacterized by the reciprocal translocation between chromosomes 9 and 22 t(9; 22) (q34; q11), resulting in Philadelphiachromosome (Ph).Considering that CML cure is only possible with a successful bone marrow transplantation and that thereare resistance cases to the tyrosine kinase inhibitor Imatinib Mesylate, prescribed in first line drug treatment; it is importantto know in detail the genes and proteins that are possibly altered in CML, favoring effective therapeutic strategies, optimizeddiagnosis and minimal residual disease detection. Among the new therapeutic approaches to CML is gene therapy, which,depending on the target gene, can be efficient to other neoplasms treatment. In this context, the aims of this work were:to proceed the molecular cloning of a DNA fragment from EZH2 gene, potential target for gene therapy, that promotesepigenetic alteration in CML and in many neoplasms; as well as to contribute to studies related to interspecies gene transferthat have high contribution to health. For this reason, the EZH2 gene was isolated from peripheral blood genomic DNAfrom CML patients and cloned in prokaryotic systems. Therefore, in this study, we proceed, defined and proved the interspeciesgene transfer procedures and discussed the future of biotechnology in researches and treatments, especially in CML.