RESUMO
<p><b>OBJECTIVE</b>To investigate the mechanisms of PTEN gene inactivation starting from DNA, mRNA and protein levels in ovarian cancers.</p><p><b>METHODS</b>Tumor tissue samples were obtained from 48 patients with epithelial ovarian cancers. Using four polymorphic markers (D10s541, D10s583, D10s1687 and D10s2491) within and flanking the PTEN gene located in chromosome 10q 23.3, polymerase chain reaction (PCR) and loss of heterozygosity (LOH) were introduced to examine LOH of PTEN gene; PCR-single strand conformation polymorphism (PCR-SSCP) was introduced to examine mutations of the fifth, sixth, seventh, and eighth exons of PTEN. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry (SP method) were applied to detect PTEN mRNA and PTEN protein expressions, respectively.</p><p><b>RESULTS</b>LOH of PTEN gene was observed in 19 of 48 (39.6%) ovarian cancers. PTEN mutations were found only in 2 (4.2%) of the cases. Absence of PTEN mRNA expression was 18.8% (9 of 48). Immunostaining of 48 cancer samples revealed that 13 (27.1%) were PTEN immunostain negative. Of these 13 samples, only 2 (15.4%) had structural, biallelic inactivation by intragenic PTEN mutations and loss of the remaining wild-type allele; 7 (53.8%) showed evidence of LOH, 5 of these 7 samples showed deletion of PTEN mRNA expression, another 2 samples showed positive expression of PTEN mRNA; 4 (30.8%) tumors had neither PTEN gene mutation nor LOH but exhibited no PTEN protein expression, 2 of these 4 cases showed deletion of PTEN mRNA expression, another 2 showed positive expression of PTEN mRNA. For the cases of PTEN protein absent staining, the rate of LOH was 69.2% (9 of 13), higher than 28.6% (10 of 35) for the positive staining (P < 0.05).</p><p><b>CONCLUSIONS</b>PTEN gene inactivation may contribute to epithelial ovarian carcinogenesis. There may be several mechanisms of PTEN gene inactivation in ovarian cancers. Protein expression deletions may be a significant mechanism.</p>
Assuntos
Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Cromossomos Humanos Par 10 , Éxons , Deleção de Genes , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Perda de Heterozigosidade , Mutação , Neoplasias Ovarianas , Genética , Metabolismo , PTEN Fosfo-Hidrolase , Genética , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , RNA Mensageiro , GenéticaRESUMO
<p><b>OBJECTIVE</b>To investigate the effects of HCMV infection on phenotypes of parotid duct epithelial cells and relative mechanisms.</p><p><b>METHODS</b>The expressions of immediate early antigen of HCMV, pan cytokeratin and cathepsin D etc. were detected by immunohistochemical staining in tissues of parotid cytomegalic inclusion disease.</p><p><b>RESULTS</b>Cytokeratin which acts as an epithelial marker became negative while staining of Cathepsin D was intensified in parotid duct epithelial cells after infected by HCMV.</p><p><b>CONCLUSION</b>It demonstrated that cytokeratin was lost through over-expression of Cathepsin D in parotid duct epithelial cells infected by HCMV.</p>
Assuntos
Animais , Feminino , Humanos , Lactente , Masculino , Camundongos , Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Antígenos Virais , Catepsina D , Citomegalovirus , Alergia e Imunologia , Fisiologia , Infecções por Citomegalovirus , Metabolismo , Patologia , Virologia , Desmina , Células Epiteliais , Metabolismo , Patologia , Virologia , Proteína Glial Fibrilar Ácida , Interações Hospedeiro-Patógeno , Imuno-Histoquímica , Queratinas , Ductos Salivares , Metabolismo , Patologia , Virologia , VimentinaRESUMO
<p><b>OBJECTIVE</b>To investigate the effects of human cytomegalovirus (HCMV) on the proliferation of duct epithelial cells of human salivary gland (HSG).</p><p><b>METHODS</b>The expression of proliferating cell nuclear antigen (PCNA) and p53 were studied in 11 cases of parotid cytomegalic inclusive disease (PCID) using immunohistochemical staining method. The effects of human cytomegalovirus (HCMV) on the proliferation of HSG were investigated by MTT method in vitro. The expression of PCNA in HSG infected by HCMV was examined using immunocytochemical staining and Western blotting.</p><p><b>RESULTS</b>PCNA was expressed weakly in most of megalic inclusion cells which were positive for HCMV, while all the megalic inclusion cells were p53 negative in all 11 cases of PCID. HCMV inhibited proliferation of HSG in vitro in a time dependent and dose dependent manner. Down-regulation of PCNA was shown in infected cells.</p><p><b>CONCLUSION</b>HCMV inhibits proliferation of HSG and down-regulation of PCNA may be an expression of the inhibition.</p>