RESUMO
The aim of this study was to investigate the correlation between MACC1 expression and resistance to cisplatin (DDP) in DDP-resistant human epithelial ovarian cancer SKOV-3 cells (SKOV-3/DDP). MACC1 mRNA and protein expression levels in SKOV-3 and SKOV-3/DDP cells were detected by reverse transcriptase polymerase chain reaction and western blot. The SKOV-3/DDP cells were divided into 5 groups: control, shVect (transfected with p-super-EGFP-1 plasmid), pshMACC1 (transfected with psuper-EGFP-shMACC1 plasmid), PD (pretreated with 20 µM PD98059), and combined (transfected with psuper-EGFP-shMACC1 plasmid and pretreated with 20 µM PD98059) groups. Cisplatin sensitivity and cell apoptosis in SKOV-3/DDP cells were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry. ERK1/2 and p-ERK1/2 expression was determined by western blot. MACC1 mRNA and protein expression levels in SKOV-3/DDP cells were 2.66 ± 0.54 and 1.95 ± 0.45 times those seen in SKOV-3 cells (P < 0.05). Cisplatin sensitivity of pshMACC1 group was much higher than that in the control and shVect groups. Cisplatin-induced cell apoptosis rates increased significantly in the pshMACC1, PD, and combined groups, compared to the control and shVect groups. Moreover, the apoptosis rate was the highest in the combined group among the 5 groups (IC50 = 20.836 ± 0.629 µM). p-ERK1/2 expression decreased significantly in the pshMACC1, PD, and combined groups (this decrease was the most obvious in the combined group). In conclusion, downregulation of MACC1 expression could enhance cisplatin sensitivity and decrease drug resistance in SKOV- 3/DDP cells.
Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Transativadores , Fatores de Transcrição/metabolismoRESUMO
The aim of this study is to investigate the ability to prenatally diagnose phenylketonuria (PKU) by using phenylalanine hydroxylase (PAH) gene mutation analysis combined with short tandem repeat (STR) linkage analysis in 118 fetuses from 112 Chinese families. Genomic DNA was extracted from the peripheral blood from members of 112 families and the exons and exon-intron boundaries of the PAH gene were amplified by PCR. PCR products were analyzed by bi-directional Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). The three variable number of tandem repeat (VNTR) markers PAH-1, PAH-26, PAH-32 were used in the prenatal diagnosis for the PKU families. We identified a spectrum of 63 different mutations, including 61 point mutations and indels, two large exon deletion mutations, and five novel mutations. A substantial proportion of mutant alleles were accounted for by p.R243Q (15.62%), EX6-96AG (9.82%), p.V399V (7.59%), p.Y356X (6.70%), and p.R413P (5.36%). The same mutations were identified in 31 prenatally genotyped fetuses. We identified 58 fetuses that carried only one mutant allele and 29 fetuses that carried no mutations of PAH and were presumed normal. PAH gene mutation analysis combined with STR linkage analysis can provide rapid and accurate prenatal diagnosis for PKU families.
Assuntos
Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Diagnóstico Pré-Natal , Alelos , Povo Asiático , Éxons , Feminino , Ligação Genética , Genótipo , Humanos , Íntrons/genética , Repetições de Microssatélites/genética , Fenilalanina Hidroxilase/sangue , Fenilcetonúrias/sangue , Mutação Puntual , Gravidez , Deleção de Sequência/genéticaRESUMO
Congenital cataract is caused by reduced transparency of the lens resulting from metabolic disorders during the fetal period. The disease shows great heterogeneity both clinically and genetically. We identified a 4-generation ethnic Han Chinese family affected by autosomal dominant congenital perinuclear cataract. The patients underwent full clinical and ophthalmologic examinations to rule out any concomitant disorders. Blood samples were collected and genomic DNA was extracted. Potential mutations in the candidate gene alpha A crystallin (CRYAA) were screened. Prenatal diagnosis was then provided for a fetus of the affected proband by chorionic villus sampling. In all patients, DNA sequencing of the CRYAA gene revealed a novel 3-bp deletion mutation in exon 3 (c.246_248delCGC), which led to deletion of codon 117 encoding arginine (p.117delR) in the peptide chain. The same mutation was not found among unaffected and healthy individuals. Bioinformatic analysis revealed that although the c.246_248delCGC is an 'in-frame' mutation, removal of arginine resulted in a significant change in the protein structure. The fetus did not possess this mutation and was confirmed to be healthy at 1-year follow-up. A novel disease-causing mutation, c.246_248delCGC (p.117delR), of the CRYAA gene has been identified in a Chinese family with autosomal-type perinuclear congenital cataracts. This is also the first report of prenatal diagnosis of this type of congenital cataract.
Assuntos
Povo Asiático/genética , Pareamento de Bases/genética , Catarata/congênito , Catarata/genética , Cristalinas/genética , Genes Dominantes , Deleção de Sequência/genética , Adulto , Sequência de Bases , China , Biologia Computacional , Feminino , Seguimentos , Heterozigoto , Humanos , Recém-Nascido , Masculino , Dados de Sequência Molecular , LinhagemRESUMO
Isolated methylmalonic acidemia (MMA) is a genetically heterogeneous disorder caused mainly by deficiency of methylmalonyl-CoA mutase. In the present study, we analyzed MUT gene mutations in 3 Chinese couples with a birth history of isolated MMA. We also provided prenatal diagnoses for the detected mutation. Exons and exon-intron boundaries of the MUT gene were analyzed by polymerase chain reaction and direct sequencing. Prenatal genetic diagnoses were performed by chorionic villus sampling after the genotypes of parents were determined. Six heterozygous mutations in the MUT gene were identified in the 3 families, including c.1880A>G (p.H627R) and IVS9-1G>A for family 1, c.1741C>T (p.R581X) and c.729insTT (p.D244fX39) for family 2, and c.616C>T (p.Q206X) and c.1280G>A (p.G427D) for family 3. Among these, c.616C>T (p.Q206X), c.1280G>A (p.G427D), IVS9-1G>A, and c.1741C>T (p.R581X) were novel mutations. These mutations were not detected in 100 normal controls. The fetus in pedigree 3 was free of the mutations carried by the parents, while the fetuses in pedigrees 1 and 2 were heterozygous mutation carriers. All 3 families decided to continue with their pregnancies and the neonates did not show any symptoms of MMA after birth. Our results indicated that mutations in the MUT gene are the primary cause of isolated MMA, and that most mutations were novel. For families with early-onset isolated MMA, direct sequencing of the MUT gene is crucial for genetic counseling, prenatal diagnosis, and identification of carriers.