Objective To study the transfection and expression of pleiotrophin (Ptn) gene in mice adipose-derived stem cells (ADSCs) so as to provide a new approach for the treatment of ischemic injury. Methods ADSCs from clean inbred C57BL/6W mice (weighing, 15-20 g) were isolated and cultured in vitro. The cell surface markers (CD29 and CD44) of ADSCs were identified by flow cytometry. The ADSCs were transfected with plasmid pIRES2-LEGFPN1 (containing Ptn gene coding sequence) as experimental group (group A) and with plasmid pLEGFP-N1 (containing GFP gene coding sequence) as control group (group B). After ADSCs were transfected by different plasmids respectively, the cells containing Ptn gene were selected by G418 (the best selected concentration was 200 μg/mL), and the immunophenotype of the cells was identified by flow cytometry after transfection. Meanwhile, real-time fluorescence quantitative PCR and Western blot were used to analyse the expression levels of Ptn mRNA and PTN protein in selected cells. Results The mice ADSCs were isolated and cultured successfully in vitro. The positive rates of the cell surface markers CD29 and CD44 of ADSCs were 99.5% and 95.8%, respectively; the double positive rate of CD44 and CD29 was 93.6%. The positive rates of the cell surface markers CD29 and CD44 of ADSCs were 99.1% and 95.6%, respectively after transfection of Ptn gene; the double positive rate of CD44 and CD29 was 93.4%. The expression levels of Ptn gene and PTN protein in group A were significantly higher than those in group B (P lt; 0.05). Conclusion The ADSCs can be stablely transfected by Ptn gene, the transfected ADSCs can express PTN protein highly, which is a new idea for tissue engineering of vascular reconstruction.
Objective To identify the expression of pleiotrophin （PTN） mRNA and protein in the colorectal cancer tissues， and to explore the clinical value of it. Methods The expressions of PTN mRNA and protein in colorectal cancer tissues （colorectal cancer group） as well as normal colorectal tissues （normal control group） were tested by using in-situ hybridization and immunohistochemistry. Results The positive rates of PTN mRNA 〔63.9% （53/83） vs. 40.7%（22/54）〕 and protein〔60.2%（50/83） vs. 33.3%（18/54）〕 in colorectal cancer group were all significantly higher than those of normal control group （P=0.008， P=0.002）. There were no significant relationship between expressions of PTN mRNA and protein with gender， age， and type of tumor （P＞0.05）， but in tissues of Ⅲ-Ⅳ stage and poor differentiation，the positive rates of PTN mRNA and protein were all higher （P＜0.05）. Conclusions The over expressions of PTN mRNA and protein in colorectal cancer tissues may directly related to the invasion and metastasis. Meanwhile， it can be used as an index to predict metastasis and prognosis of colorectal cancer.