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This study is to investigate whether naked plasmid DNA can effectively transfect lung cancer related cells and express human kallistatin, an endogenous protein that inhibits angiogenesis and tumor growth, and to explore the biological activity of the low-level expressed kallistatin to lung cancer in vitro and in vivo. The plasmids were delivered with Lipofectamine 2000 to transfect various lung cancer related cells. Kal expression was determined by ELISA. The biological effects of Kal expression on proliferation, migration and apoptosis rate of the cells were examined. In subcutaneous NCI-H446 xenograft model, pKal was injected directly into tumors, the changes of CD34, Ki-67 and E-cadherin expression were detected with immunohistochemical assay, the tumor apoptosis was analyzed with TUNEL assay. Both the endothelial cell and lung cancer cells could express kallistatin after plasmid transfection. The proliferation and migration of human umbilical vein endothelial cells were inhibited, but the apoptosis rate was not affected. The proliferation rates of all the three tested lung cancer cells, such as NCI-H446, NCI-H460 and A549, were inhibited, and their apoptosis rates were enhanced, but different cells behaved differently. In subcutaneous NCI-H446 xenograft model, intratumor injection of pKal inhibited the growth of lung cancer by reducing angiogenesis and proliferation of tumor cells. In conclusion, this study demonstrated the efficacy of plasmid-mediated expression of kallistatin to lung cancer related cells, thus providing a basis for their clinical application in the treatment of lung cancer.

Objective: To investigate the correlation between visceral adipose tissue-derived serine protease inhibitor (vaspin) concentration and insulin sensitivity in the visceral adipose tissue of young obese Sprague-Dawley (SD) rats., Methods: Twenty-four SD rats which had been weaned 3 weeks before were randomly divided into two groups (n=12 each) to receive a high-fat and normal diet. The weight and abdominal circumference (AC) of each rat were measured, the fasting plasma glucose (FPG) and fasting insulin (FINS) in blood from the angular vein were measured after 12 hours of fasting and blood glucose (BG) and insulin (INS) levels in blood from the angular vein were measured at 60 and 120 minutes after intraperitoneal injection of 50% glucose (2 g/kg). The rats were sacrificed, and their liver and visceral adipose tissue were weighed. The vaspin concentration of the visceral adipose tissue in each rat was measured using ELISA. Correlation analysis was performed on the vaspin concentration and other indices., Results: Compared with the normal diet group, the high-fat diet group showed significantly higher weight, AC, weight of visceral adipose tissue, FPG, FINS, 120 minute INS level, vaspin concentration, homeostasis model assessment for insulin resistance (HOMA-IR) and homeostasis model assessment of β cell function (HOMA-β) (P<0.05) Insulin sensitivity index (ISI) was significantly lower (P<0.01). Vaspin concentration was positively correlated with visceral adipose tissue and liver weight, AC, 120 minute INS level, FPG, FINS, HOMA-IR and HOMA-β (P<0.05), and negatively correlated with ISI (P<0.05)., Conclusions: High expression of vaspin is associated with insulin resistance in young obese SD rats. Vaspin is presumably an adipocytokine that can increase insulin sensitivity, promote insulin secretion by islet β-cells and improve glucose tolerance, and it may be involved in insulin resistance and the disturbance of carbohydrate metabolism.

Objective: Random amplified polymorphic DNA (RAPD) analysis was used to detect the genomic variant in B16 melanoma, and to seek the tumor related DNA fragments., Methods: Genomic DNA from B16 melanoma and C57BL/6J mouse normal tissues were amplified by RAPD with 105 random primers, the significantly different DNA fragments were isolated, cloned and sequenced. DNA sequences were analyzed with GenBank data., Results: 24 of the 105 primers generated polymorphic profiles when the B16 melanoma RAPD profile was compared to that of its normal tissue DNA. By amplification of the primer AB8-5, a tumor band showing loss with respect to normal band was detected and this DNA fragment was designated as B8-5. B8-5 was a 610 bp fragment, the sequencing result of B8-5 showed 99% homology with muscle pigment epithelium-derived factor (PEDF) gene, and 100% homology with muscle pigment epithelium-derived factor mRNA. B8-5 was therefore regarded as PEDF gene., Conclusion: Our result found that allelic losses exist in PEDF gene, and therefore suggest that PEDF is associated with tumorigenesis of B16 melanoma.