RESUMO
We assessed the relative expression of oestrogen receptor (ER)alpha and oestrogen receptor (ER)beta mRNAs in 36 human endometrial cancers using a multiplex polymerase chain reaction (PCR). To determine whether or not the expression of ER subtypes in endometrial cancers is associated with clinicopathological parameters, we examined correlations between ER subtypes and age, tumour grade and depth of myometrial invasion. Using multiple regression analysis, myometrial invasion showed a significant correlation with ER-beta: ER-alpha ratio (r = 0.54, P = 0.0007). The ER-beta:ER-alpha ratio was high in advanced invasive carcinoma. Western blotting analysis showed that ER-beta proteins were highly expressed in comparison with ER-alpha proteins in endometrial cancer with severe myometrial invasion. Our results suggest that ER-beta is important in the progression of myometrial invasion.
Assuntos
Neoplasias do Endométrio/genética , Regulação Neoplásica da Expressão Gênica , Invasividade Neoplásica/genética , Receptores de Estrogênio/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA de Neoplasias/genética , Progressão da Doença , Neoplasias do Endométrio/patologia , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Feminino , Humanos , Pessoa de Meia-Idade , Miométrio/patologia , Reação em Cadeia da Polimerase , Receptores de Estrogênio/genéticaRESUMO
Several proteins, including transforming growth factor beta (TGF-beta) receptor type I (RI), TGF-beta receptor type II (RII), Smad2, Smad3, and Smad4/DPC4, have been identified in the transduction pathway of the tumor suppressor TGF-beta. Mutations in TGF-beta RI, TGF-beta RII, Smad2, and Smad4/DPC4 genes are associated with several human cancers. The present study examines these gene mutations in 32 human ovarian cancers and 14 patient-matched normal tissues. For the first time, mutations in the Smad2 and Smad4 genes were analyzed in relation to human ovarian cancer. Gene mutations of TGF-beta RI, TGF-beta RII, Smad2, and Smad4 were analyzed using specific primers by PCR-single-strand conformational polymorphism (SSCP), and the results revealed a frameshift mutation at codons 276-277 (CTCTGG-->CTGCGTGG) in exon 5 of TGF-beta RI in 10 of 32 tumor samples (31.3%). This mutation was associated with reduced or absent expression of TGF-beta RI protein and p53 protein in tumor tissues. We detected SSCP variants of TGF-beta RII in exon 2 in 20 of 32 tumors. Sequence analysis of these variants revealed an A to G transition at the seventh band of intron 2. In this A to G polymorphism in intron 2, 12 samples (37.5%) had A/A alleles, 12 (37.5%) had A/G alleles, and 8 (25%) had G/G alleles. We detected Smad2 SSCP variants in exon 4 in 12 of 32 tumors (37.5%). Sequence analysis revealed a 2-bp deletion in the polypyrimidine tract of intron 3, which is located at position -39 to -56 in the splice acceptor site of the intron 3-exon 4 junction. No SSCP variants were detected in the Smad4 gene. These findings suggest that mutations in the TGF-beta RI and in its signal transduction pathway are likely responsible for human ovarian carcinogenesis.
Assuntos
Receptores de Ativinas Tipo I , Mutação da Fase de Leitura/genética , Perda de Heterozigosidade/genética , Neoplasias Ovarianas/genética , Transdução de Sinais/genética , Fator de Crescimento Transformador beta/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo Genético , Polimorfismo Conformacional de Fita Simples , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Transdução de Sinais/fisiologia , Proteína Smad2 , Proteína Smad4 , Transativadores/genética , Fator de Crescimento Transformador beta/fisiologiaRESUMO
8-oxo-deoxyguanosine triphosphate (8-oxo-dGTP) is a major oxidation product in the nucleotide pool of the cell and is a potent mutagen, because it can be incorporated into DNA with equal frequency opposite either template C or A. The human MTH1 gene (hMTH1) is a homologue of the E. coli mutator gene mutT, which encodes 8-oxo-dGTPase. hMTH1 protein reduces spontaneous mutations by removing 8-oxo-dGTP from the triphosphate pool. To determine whether this gene is associated with carcinogenesis of human ovarian cancer, the present study examined, for the first time, the hMTH1 sequence in 49 ovarian cancers and 9 ovarian cancer cell lines by means of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing analyses. A Gright curved arrow A transition at codon 83 was detected in one patient and one cell line (3.4%), followed by an amino acid change (valineright curved arrow methionine) which was known to cause the protein to be less active in vitro. This one base substitution was found in normal and corresponding tumor DNA, and its allele type was heterozygous. The same change has been detected in HNPCC (hereditary non-polyposis colorectal cancer) and gastric cancer patients, and thus it may not represent a mutation specific for ovarian cancer. A silent Tright curved arrow C transition at codon 119 was detected in 12 patients and 2 cell lines (24.1%). No specific mutations in hMTH1 were found in either ovarian cancer patients or cell lines. Thus, it appears that hMTH1 is not directly associated with ovarian cancer.
Assuntos
Enzimas Reparadoras do DNA , Reparo do DNA/genética , DNA de Neoplasias/genética , Genes , Proteínas de Neoplasias/genética , Neoplasias Ovarianas/genética , Monoéster Fosfórico Hidrolases/genética , Substituição de Aminoácidos , Cromossomos Humanos Par 7/genética , Códon/genética , Análise Mutacional de DNA , Nucleotídeos de Desoxiguanina/metabolismo , Feminino , Variação Genética , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Células Tumorais CultivadasRESUMO
The Smad3 gene is a member of the Smad family, vertebrate homologues of Drosophila Mad, and its gene product is a cytoplasmic element in the transforming growth factor-beta (TGF-beta) signaling pathway. Mutations in TGF-beta receptors and their cytoplasmic elements of transduction signals commonly accompany various cancers. Using PCR-SSCP analysis we searched for the presence of Smad3 gene mutations in 36 human ovarian cancers, and found that 15 cases (41. 7%) had a polymorphism at codon 103. Because this mutation was not accompanied by amino acid replacement, the present results show that the mutations in the Smad3 gene are unlikely to be involved in human ovarian cancers.
Assuntos
Proteínas de Ligação a DNA/genética , Mutação , Neoplasias Ovarianas/genética , Polimorfismo Conformacional de Fita Simples , Transativadores/genética , Adolescente , Adulto , Idoso , Animais , Primers do DNA , Drosophila , Feminino , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Transdução de Sinais , Proteína Smad3 , Fator de Crescimento Transformador beta/fisiologia , VertebradosRESUMO
In order to assess the bone atrophy lesions of epileptic patients, the bone mineral densities (BMDs) of their lumbar spines and femoral necks were measured using quantitative digital radiography (QDR). The study groups were 44 patients on long-term medication for epilepsy and 62 healthy control subjects. We selected patients who had been taking phenytoin, barbiturates, and/or acetazolamide for at least 5 years. BMDs at both sites were significantly lower in the patient group than in the control group. No sex differences were found in BMDs. There were no significant correlations with the onset or the duration of illness and BMD. We compared BMD according to the type of epileptic drug being taken and theorized that phenytoin, barbiturates, and acetazolamide reduced BMD. BMDs of the 15 patients were measured again 7 years later, and were found to be significantly lower at both sites than in the previous examination. These results confirm the presence of bone atrophy lesions in epileptic patients on long-term antiepileptic drugs. Patients on antiepileptic therapy for long periods should have their BMDs checked, because they are prone to developing bone atrophy.
