Search

Root cDNA library of peanut was constructed with the roots of Arachis hypogaea cv Minhua 6 using SMART technique. The original library had a titer of 1. 3 x 106cfu/mL, of which 95. 8% clones were recombinant and insert cDNAs were from 750bp to 2000bp. 35 clones from the cDNA library were sequenced and 30 valid sequences were generated. 25 known or hypothentical functional genes, 7 unidentified genes and 13 novel gene were annotated by Blastx searches against the NCBI non - redundant protein database. Among these genes, 34 genes (97. 1%) had not been reported in peanut. The result revealed that expression genes in peanut root reported online at present were still rare. The full length cDNA library of peanut roots constructed in this study would be beneficial to mine important functional genes expressed in peanut roots and supply basis to study on the growth and development of peanut roots from molecular level. [ABSTRACT FROM AUTHOR]

In this study , 48 SSR markers were used to assess the genetic variation of 63 peanut cultivars. The results showed that total 251 polymorphic alleles were detected , and the number of polymorphic fragments per marker ranged from 2 to 13 with an average of 5. 23. The genetic diversity index ranged from 0. 508 to 2. 243 with an average of 1.272. Polymorphism information content (PIC) ranged from 0. 252 to 0. 873 with an average of 0. 647 per primer pairs. Genetic similarity coefficients (GS) ranged from 0.657 to 0 . 9 6 0 , GS were lower among different botanical types , and genetic relationship was more distant among different origins. Cluster analysis was performed with the GS and the UPGMA method. 63 cultivars were divided into 4 groups at the threshold of 0. 74. The result of clustering analysis supported the conventional classification. [ABSTRACT FROM AUTHOR]

Aim: To investigate the potential roles of Delta-like ligand 4 (DLL4) on the biological behavior of gastric cancer cells and its molecular mechanisms., Methods: A recombinant eukaryotic expression vector containing human DLL4 gene was constructed and transfected into the human gastric cancer cell line SGC7901. Clones with up-regulated DLL4 were selected and amplified. The effect of DLL4 up-regulation on gastric cancer cell growth was assessed using cell growth assay. The migration and invasion were assessed using a transwell migration assay and matrigel invasion assay. Matrix metalloproteinases were detected using the zymogram technique. Cells were implanted subcutaneously into male BALB/c nu/nu mice. Tumor volumes were then calculated and compared. DLL4 staining in the implanted tumor was performed using immunohistochemistry technique., Results: Growth curves over a six-day time course showed significantly promoted cell proliferation of SGC7901 cells with up-regulated DLL4. DLL4 up-regulation in SGC7901 cells promoted the migration (205.4 ± 15.2 vs 22.3 ± 12.1, P < 0.05) and invasion (68.8 ± 5.3 vs 18.2 ± 6.0, P < 0.05) in vitro and tumorigenicity in vivo (2640.5 ± 923.6 mm(3) vs 1115.1 ± 223.8 mm(3), P < 0.05). Furthermore, significantly increased mRNA level and increased secretion of matrix metalloproteinase-2 (MMP-2) proenzyme were observed in SGC7901 cells with up-regulated DLL4. However, increased MMP-9 mRNA level but decreased extracellular MMP-9 proenzyme level was observed., Conclusion: Our observations indicated a mechanism by which activation of DLL4-mediated Notch signaling promotes the expression and secretion of MMP-2 proenzyme and influences the progress of gastric cancer.

Aim: To quantitatively assess the ability of double contrast-enhanced ultrasound (DCUS) to detect tumor early response to pre-operative chemotherapy., Methods: Forty-three patients with gastric cancer treated with neoadjuvant chemotherapy followed by curative resection between September 2011 and February 2012 were analyzed. Pre-operative chemotherapy regimens of fluorouracil + oxaliplatin or S-1 + oxaliplatin were administered in 2-4 cycles over 6-12 wk periods. All patients underwent contrast-enhanced computed tomography (CT) scan and DCUS before and after two courses of pre-operative chemotherapy. The therapeutic response was assessed by CT using the response evaluation criteria in solid tumors (RECIST 1.1) criteria. Tumor area was assessed by DCUS as enhanced appearance of gastric carcinoma due to tumor vascularity during the contrast phase as compared to the normal gastric wall. Histopathologic analysis was carried out according to the Mandard tumor regression grade criteria and used as the reference standard. Receiver operating characteristic (ROC) analysis was used to evaluate the efficacy of DCUS parameters in differentiating histopathological responders from non-responders., Results: The study population consisted of 32 men and 11 women, with mean age of 59.7 ± 11.4 years. Neither age, sex, histologic type, tumor site, T stage, nor N stage was associated with pathological response. The responders had significantly smaller mean tumor size than the non-responders (15.7 ± 7.4 cm vs 33.3 ± 14.1 cm, P < 0.01). According to Mandard's criteria, 27 patients were classified as responders, with 11 (40.7%) showing decreased tumor size by DCUS. In contrast, only three (18.8%) of the 16 non-responders showed decreased tumor size by DCUS (P < 0.01). The area under the ROC curve was 0.64, with a 95%CI of 0.46-0.81. The effects of several cut-off points on diagnostic parameters were calculated in the ROC curve analysis. By maximizing Youden's index (sensitivity + specificity - 1), the best cut-off point for distinguishing responders from non-responders was determined, which had optimal sensitivity of 62.9% and specificity of 56.3%. Using this cut-off point, the positive and negative predictive values of DCUS for distinguishing responders from non-responders were 70.8% and 47.4%, respectively. The overall accuracy of DCUS for therapeutic response assessment was 60.5%, slightly higher than the 53.5% for CT response assessment with RECIST criteria (P = 0.663). Although the advantage was not statistically significant, likely due to the small number of cases assessed. DCUS was able to identify decreased perfusion in responders who showed no morphological change by CT imaging, which can be occluded by such treatment effects as fibrosis and edema., Conclusion: DCUS may represent an innovative tool for more accurately predicting histopathological response to neoadjuvant chemotherapy before surgical resection in patients with locally-advanced gastric cancer.

Background/aims: To investigate whether the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) are of prognostic significance in ampullary carcinoma., Methodology: Twenty-two resected tumor specimens from patients with ampullary carcinoma were immunohistochemically stained for VEGF and CD34 (surrogate for vessels) by streptavidin-peroxidase method., Results: Expression of VEGF in tumor tissue was found in 50% of patients. The mean MVD for entire group was 26.4 +/- 12.8. A significantly higher MVD was observed in the tumors with positive VEGF expression (35.0 +/- 9.6) compared with that of negative VEGF expression (17.7 +/- 9.3) (p<0.01). The expression of VEGF and MVD were closely related lymph node status and tumor TNM stage. The positive expression rate of VEGF and the average MVD in patients with lymph node metastases were 85.7% and 33.1 +/- 10.8 respectively, which were significantly higher than those in patients without lymph node metastases (33.3% and 22.8 +/- 11.8 respectively) (p<0.05). The positive expression rate of VEGF and the average MVD in patients with stage III and were 75% and 36.3 +/- 8.4 respectively, which were significantly higher than those in patients with stage I (25% and 18.4 +/- 10.1 respectively) or stage II (50% and 23.8 +/- 13.4 respectively) (p<0.05). The Kaplan-Meier survival curves showed that the 3-year survival rate for patients with positive VEGF expression or a high MVD (9.1% and 10% respectively) were lower than those in patients with negative VEGF expression or a low MVD (63.64% and 58.33% respectively) (p<0.05)., Conclusions: VEGF is positively correlated with MVD in ampullary carcinoma. VEGF and angiogenesis may play an important role in lymph node metastasis and progression of ampullary carcinoma. VEGF and MVD appear to be important prognostic predictor in patients with ampullary carcinoma.

OBJECTIVE: To clone vascular endothelial growth factor (VEGF) cDNA gene, construct its eukaryotic expression vector and to express this recombinant plasmid in COS-7 cells. METHODS: Human VEGF165 cDNA was amplified by RT PCR from human ovarian carcinoma. After DNA sequenced, the VEGF165 cDNA was inserted into eukaryotic expression vector pcDNA3.1(-). The recombinant plasmid pcDNA3.1 VEGF165 containing VEGF165 cDNA was identified by enzyme digestion and transferred into COS-7 cells mediated by liposome. The transient expression of VEGF was detected by immunohistochemical staining. RESULTS: The cloned VEGF165 cDNA was confirmed by enzyme digestion and DNA sequence analysis. The immunohistochemical results showed that the VEGF165 protein was expression in COS-7 cells 72 h after gene transfer. CONCLUSION: VEGF165 cDNA gene successfully cloned and expressed in COS-7 cells.