Polymorphisms of homocysteine metabolism enzyme-related genes MS and MSR in Buyi, Dong and Miao ethnics from Guizhou / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate polymorphisms of homocysteine metabolism enzyme-related genes methionine synthase (MS) and methionine synthase reductase (MSR) in Buyi, Dong, Miao ethnics from Guizhou.</p><p><b>METHODS</b>Genotypes of MS and MSR genes of healthy individuals from the three ethnic groups were determined with a TaqMan-MGB probe genotyping method and compared.</p><p><b>RESULTS</b>For Buyi, Dong and Miao ethnics from Guizhou, frequencies of MS gene 2756G allele were respectively 12.0%, 8.9% and 15.4%. However, no significant difference was found by statistics. Frequencies of MS A2756G alleles for the three ethnic groups are similar to those of Han Chinese from Beijing and Henan, Hui ethnics from Ningxia as well as European populations, but differ significantly from those of Japanese, Indians, Africans and Nigerians (P < 0.05). Frequencies of MSR gene 66 G allele were respectively 32.3%, 30.4% and 21.2% for Buyi, Dong and Miao ethnics. Miao is significantly lower than Buyi and Dong (P< 0.05). Frequencies of MSR gene A66G alleles for the three ethnic groups are similar to those of Han Chinese from Beijing and Guangdong, Japanese, Africans and Nigerians populations, but differ significantly from those of Indians and European (P< 0.05).</p><p><b>CONCLUSION</b>The distributions of MS gene A2756G and MSR gene A66G polymorphisms have differed significantly between the three ethnic groups and individuals from various regions.</p>

Identification of a TTR gene mutation in a family with hereditary vitreous amyloidosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the disease gene in a family with hereditary vitreous amyloidosis.</p><p><b>METHODS</b>A family with hereditary vitreous amyloidosis was investigated. Blood samples were collected from 4 members of this family including 3 patients and 1 asymptomatic individual. Genomic DNA was extracted from peripheral blood sample and subjected to amplification of 4 exons of transthyretin (TTR) gene. The PCR products were purified and subjected to direct sequencing. A total of 150 unrelated individuals were used as controls.</p><p><b>RESULTS</b>A heterozygous mutation G to C at codon 103 in exon 3 of TTR gene (Gly103Arg) was detected in all 4 members of the family but not in the unrelated controls.</p><p><b>CONCLUSION</b>The heterozygous Gly103Arg mutation of TTR gene may be related to the development of hereditary vitreous amyloidosis in this family.</p>

Prognostic significance of hTERT mRNA quantitative expression in resected gastric carcinomas / 中华肿瘤杂志

<p><b>OBJECTIVE</b>By quantitative detection of telomerase expression, we investigated the relationship between telomerase expression and malignant behavior and prognosis in gastric carcinoma.</p><p><b>METHODS</b>A real-time quantitative RT-PCR (RQ-PCR) was used to quantify the hTERT mRNA copy numbers in 89 samples of gastric carcinoma and corresponding non-cancerous tissues. The clinicopathological data of enrolled patients such as age, sex, tumor size, tumor site, pathologic type, histodifferentiation, infiltration depth, lymph node metastasis, stage and survival were obtained, and were made one factor analysis of variance and COX regression prognostic analysis with those above mentioned markers. Follow-up was completed as of February 28, 2010. The median follow-up was 24 months.</p><p><b>RESULTS</b>hTERT from gastric carcinomas and corresponding non-cancerous tissues was 16.98 ± 3.56 and 11.37 ± 2.15, respectively (P < 0.05), the telomerase activity in gastric cancer was significantly higher than that in non-cancerous tissue (P < 0.05). Telomerase activity showed a positive correlation with depth of invasion, tumor differentiation and nodal metastasis (P < 0.01), and negative correlation with survival.</p><p><b>CONCLUSIONS</b>Gastric cancer with high hTERT mRNA expression indicates a more malignant potential. Detection of hTERT mRNA in gastric cancer may be useful in a better understanding of invasion, metastasis, as well as prognosis of gastric cancer and provide a more efficient therapy. The quantitative expression of hTERT mRNA, infiltration depth and pTNM stage are significant afactors affecting the prognosis of patients with gastric carcinoma.</p>

Neuron specific enolase gene silencing suppresses proliferation and promotes apoptosis of lung cancer cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of neuron specific enolase (NSE) gene silencing on the cell proliferation and apoptosis of lung cancer cells in vitro.</p><p><b>METHODS</b>NSE protein expression was detected in human small cell lung cancer cell line NCI-H446 and non-small cell lung cancer cell line A549 by immunocytochemistry, and a small interference RNA (siRNA) was transfected into the cells to inhibit NSE gene expression. The changes in the cell cycle, apoptosis, Ki67 protein and caspase-3 activity in the transfected cells were observed by flow cytometry, Western blotting and colorimetric assay, respectively.</p><p><b>RESULTS</b>Both A549 and NCI-H446 cells expressed NSE protein. Transfection of siRNA for NSE gene significantly inhibited the expression of NSE gene in the cells, resulting in an inhibition rate exceeding 90%. NSE gene silencing caused significantly decreased cell percentage in S phase and the expression of Ki67 protein, and increased the cell apoptotic rate and caspase-3 activity.</p><p><b>CONCLUSION</b>NSE gene expression promotes the cell proliferation and inhibits the cell apoptosis in lung cancer cells with neuroendocrine differentiation, which might be a causative factor contributing to increased malignancy of the cells.</p>

Helicobacter pylori cytotoxin associated protein CagA regulates gastrin gene promoter activity / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the regulatory effect of Helicobacter pylori CagA protein on gastrin promoter and the related signaling pathways as to further elucidate the mechanism of the development and progression of human gastric carcinoma.</p><p><b>METHODS</b>After pcDNA3.1ZEO(-)/CagAand PGL/GP were identified by double restriction enzyme digestion, PCR and sequencing, the gastric cancer cell lines AGS and SGC-7901 cells were co-transfected with pcDNA3.1ZEO(-)/CagA and PGL/GP for 48 h. Alternatively, AGS and SGC-7901 cells were transfected by PGL/GP for 36 h later, and infected with Helicobacter pylori for additional 12 h. Meanwhile, the transfected and infected cells were treated using the JAK2 signaling pathway inhibitor AG490 and the ERK signaling pathway inhibitor U0126. The untreated cells and empty-vector-transfected cells were used as the control. Finally, luciferase activity was detected using the luciferase reporter assay system in transfected and infected cells. The levels of gastrin mRNA was determined by TaqMan® real-time quantitative PCR.</p><p><b>RESULTS</b>After co-transfection with pcDNA3.1ZEO(-)/CagA and PGL/GP, the activities of luciferase were increased by 251.3, 106.1 and 2.4 times in AGS cells and 35.8, 22.7 and 13.4 times in SGC-7901 cells, respectively, as compared with that of the control, pcDNA3.1 ZEO(-)/CagA + PGL3/Basic and pcDNA3.1 ZEO(-) + PGL/GP groups. The activities of luciferase in PGL/GP transfection and HP infection group were also increased by 1673.2, 33.5, 1.4 times in AGS cells and 1180.2, 72.2 and 1.5 times in SGC-7901 cells, respectively, as compared with that of the control, PGL3/Basic + HP and PGL/GP groups. There were statistically significant differences between them (P < 0.05), which suggested that the transcription activity of gastrin promoter increased significantly. But after adding the inhibitor AG490 and U0126, respectively, the activities of luciferase were significantly decreased by 95.7% (U0126) and 33.0% (AG490) in co-transfected AGS cells and 94.8% (U0126) and 86.2% (AG490) in co-transfected SGC-7901 cells with pcDNA3.1ZEO(-)/CagA and PGL/GP (P < 0.05). In the PGL/GP transfection and HP infection group, the activities of luciferase were significantly decreased by 24.6% (U0126) and 25.8% (AG490) in AGS cells and 57.3% (U0126) and 14.1% (AG490) after adding the inhibitor AG490 and U0126, respectively (P < 0.05). The results showed that the gastrin promoter activities were significantly inhibited. The gastrin mRNA levels were 3.0 and 4.5 times higher in HP-infected AGS and SGC-7901 cells, respectively, than that in the control groups. In the cells transfected with pcDNA3.1ZEO(-)/CagA, the gastrin mRNA levels were raised 10.8 and 2.3 times (AGS cells) and 10.9 and 16.2 times (SGC-7901 cells), respectively, as compared with that of control and pcDNA3.1ZEO(-) groups. All of the differences were statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>These results suggest that CagA may activate the gastrin promoter and up-regulate the expression of gastrin gene, and CagA is one of the important proteins in regulating gastrin gene expression. The ERK/MAPK and JAK/STAT signaling pathways may be involved in the controlling of gastrin gene expression by CagA.</p>