[The effects of tumor antigen gene OVA66 on biological characteristics of tumor cells].

AIM: To explore the effects of tumor antigen gene OVA66 on the biological characteristics of tumor cells. METHODS: The eukaryotic expression vector pcDNA3.1-mock and recombined vector pcDNA3.1-OVA66 were transfected into hepatoma cell line SMMC-7721 by LipofectAMINETM 2000. After stable selection and clone proliferation of cells, the expression of OVA66 gene and protein was detected by RT-PCR, Western blot and immunocytochemical (ICC) staining. The cell growth cycle was analyzed by FACS. The ultrastructure was observed under electron microscope. The experiments in cell migration and invasion were performed in vitro. The OVA66-associated genes were analyzed by genechip technique after gene transfection. RESULTS: OVA66 was highly expressed in 7721 cells transfected with pcDNA3.1-OVA66 at mRNA level. Western blot result demonstrated that OVA66 protein content was notably increased compared with that in control cells. Electron microscope and FACS results indicated that OVA66 gene promoted the growth and proliferation of tumor cells. In vitro, the experiments in cell migration and invasion showed that this gene enhanced migration and invasion of tumor cells. The result of genechip demonstrated that the over- expression of OVA66 gene increased the expression of plasminogen activator inhibitor-1 gene (PAI-1), suggesting that it had some effects on tumor invasion and metastasis. CONCLUSION: Tumor antigen gene OVA66 and it's protein demonstrate a series of biological characteristics of tumor cells, which can promote the proliferation, migration and invasion of tumor cells.

[Experimental study on the role of cytokines and keratinocytes in the survival mechanism of auto and allogeneic mixed skin grafting].

OBJECTIVE: To explore the role of cytokines and keratinocytes in the survival mechanism of mixed auto and allogeneic skin grafting. METHODS: Thirty-six SD rats were employed in the study. The rat model with mixed auto and allogeneic skin grafting and mixed human epithelial and lymphocytic culture (MELC) model were established. The change of IL-10 in the serum and the supernatant of the cultured tissue sample from the local wound was observed after the mixed skin grafting in scalded rats. And the role of epithelium in the induction of immunosuppression in vitro was monitored. RESULTS: The serum IL-10 content in the rats with mixed skin grafting (25.89 +/- 2.82 ng/L) at 7 postoperative day (POD) was evidently higher than that in normal rats (14.20 +/- 2.43 ng/L) (P < 0.05). The IL-10 content in the culture supernatant of rat tissue samples exhibited evident different during 4-14 PODs (P < 0.05-0.01), while which was no difference to that in normal rat on 21st and 28th POD. The inhibiting effects of autologous epithelia and keratinocytes in MELC system were correlated with their dosage. After the adding of autologous keratinocytes to MELC system the cytokines secreted from Th1 could induce the secretion of cytokines from Th2 by IL-10 mediation. This effect could be corrected by the addition of monoclonal antibody of IL-10. CONCLUSION: The keratinocytes inlayed in the autoskin during mixed grafting could increase the local IL-10 level by activating Th2 cells, which might be one of the important reasons of the survival of mixed skin grafting.

[Study of HLA molecules and its associated genes expression in human ovarian cancer cells].

AIM: To explore the correlation between the expressions of HLA gene and its related gene, and expression of class II transactivator (CIITA) gene induced by IFN-gamma in human ovarian cells. METHODS: The expression of HLA molecule in the tumor cells was detected by Western blot, immunohistochemical staining and flow cytometry. The expressions of transporters associated with antigen processing (TAP), low molecular weight peptides (LMP), and CIITA genes were analyzed by RT-PCR. RESULTS: Abnormal expression rate of HLA class I molecule reached 45% in the 11 ovarian cancer cells. The expressed abnormalities of HLA class I molecule had relation to those of 4 genes (TAP1, TAP2, LMP2 and LMP7). Expression of HLA class II molecule was identical with that of CIITA gene in the ovarian cancer cells or other tumor cells. After IFN-gamma treatment, expressions of HLA class I and II molecule were increased in the cells of CIITA-expressing constitutively or inducibly, while no enhancement of HLA molecule expression manifested itself in the tumor cells of that CIITA was not yet expressed after IFN-gamma induction. CONCLUSION: Deletion of TAP and LMP gene expression in the ovarian cancer cells is an important factor causing abnormal expression of HLA class I molecule, suggesting that the CIITA gene has involved in the modulation of HLA classes I and II molecule expressions in the tumor cells.