Expressions of Fas, CTLA-4 and RhoBTB2 genes in breast carcinoma and their relationship with clinicopathological factors / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The purpose of this study was to explore the clinical significance of expression of Fas, CTLA-4 and RhoBTB2 genes in breast carcinoma.</p><p><b>METHODS</b>Semi-quantitative reverse transcriptive polymerase chain reaction (RT-PCR) was used to analyze the mRNA expression levels of the three genes in tumor tissues from 60 patients with primary breast cancer and normal breast tissues of 30 cases. The relationship between gene expression and clinicopathological factors were analyzed and determined.</p><p><b>RESULTS</b>The relative expression levels (gray scale ratio between target gene and internal reference gene) of Fas, CTLA-4 and RhoBTB2 genes in breast carcinoma tissues were 0.699 +/- 0.285, 1.045 +/- 0.302 and 0.625 +/- 0.160, respectively. In the normal breast tissues, they were 0.502 +/- 0.178, 0.418 +/- 0.140 and 0.843 +/- 0.218, respectively. There were statistically significant differences of the expression of those three genes between carcinoma tissues and normal breast tissues (P < 0.01). The expression level of Fas in carcinoma tissues was significantly higher in lymph node matastasis positive patients (0.782 +/- 0.313) than that in node-negative patients (0.557 +/- 0.146, P < 0.01). The expression level of CTLA-4 gene in carcinoma tissues was lower in II stage patients (0.978 +/- 0.330) than that in III stage patients (1.134 +/- 0.240, P < 0.05). The expression level of RhoBTB2 gene was lower in invasive ductal carcinoma (0.597 +/- 0.157) than that in invasive lobular carcinoma (0.717 +/- 0.145, P < 0.05). There were no correlations of expression of the three genes at mRNA level and age, ER, PR, HER2 status and survival time. Furthermore, no correlation was seen among the three genes expression (P > 0.05).</p><p><b>CONCLUSION</b>The expression of all the three genes at mRNA level is involved in genesis and progression of breast cancer. There exist correlations between Fas expression and axillary lymph node matastasis, CTLA-4 expression and disease stage, and RhoBTB2 expression and pathological type of breast cancer.</p>

Studies on the genetic pathogenesis of myasthenia gravis caused by CTLA-4 gene polymorphism / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the genetic pathogenesis of myasthenia gravis (MG) caused by cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene polymorphisms and regulation function of transcription factor.</p><p><b>METHODS</b>ELISA assay was used to determine the expression level of serum sCTLA-4 in MG. Four single nucleotide polymorphisms (SNPs) of CTLA-4 at exon 1 +49, promoter -318, -1661, -1772 were analyzed by restriction fragment length polymorphism (RFLP). Transcription factor nuclear factor 1(NF-1) and c/EBPbeta binding site were confirmed by chromatin immunoprecipitation(CHIP) assay.</p><p><b>RESULTS</b>It was found that the frequencies of the GG+49 genotype and G+49 allele are higher in MG patients with thymoma than those in patients of thymic hyperplasia and normal thymus subgroups. T/C-318 is not correlated with MG. The frequency of CT-1772 genotype is significantly higher in MG patients, especially in MG patients with thymoma, when compared with that in healthy controls. Meanwhile, the frequency of the G-1661 allele and GG-1661 genotype is lower in MG patients. Linkage disequilibrium (LD) between each SNPs in promoter -1772, -1661, -318 and coding sequence 1 (CDS 1) +49 is apparent. sCTLA-4 levels in patients' sera are correlated with the haplotype and genotype. T/C-1772 and A/G-1661 SNPs change the sequence of transcription factor NF-1 and c/EBPbeta binding sites. DNA variants lose site-specific binding activity of transcription factor regulated by lectin ConA and PHA.</p><p><b>CONCLUSION</b>There are strong positive linkages among four SNPs. C/T-1772 and A/G-1661 polymorphisms can result in inefficient transcription of CTLA-4 gene. T>C-1772 mutation also affects gene splicing. These SNPs may constitute a factor of susceptibility to disease.</p>