Development of two continuous hemocyte cell sublines in the Asian corn borer Ostrinia furnacalis and the identification of molecular markers for hemocytes

Granulocytes and plasmatocytes play important roles in clearing foreign objects in insects,but it is difficult to distinguish between them in immune reactions.Based on the hemocyte cell line SYSU-OfHe-C established at our lab,two cell sublines,SYSU-OfHe-C Granulocyte(Gr cells)and SYSU-OHe-C Plasmatocyte(PI cells),which possess the morphological characteristics of granulocytes and plasmatocytes,respectively,were established.Gr and PI cells showed different behaviors in immune reactions,such as spreading,phagocytosis and encapsulation.PI cells were easier to spread,but Gr cells tended to undergo aggregation,indicating that they may take different strategies to clear foreign objects.These results also suggested that granulocytes and plasmatocytes may express some different proteins.By comparing the gene expression in cells from the two sublines,1662 differentially expressed genes were identified,and 13 out of 30 transmembrane proteins highly ex pressed in PI cells(six)or Gr cells(seven)were further screened and confirmed by reverse-transcription polymerase chain reaction(PCR).Finally,three transmembrane genes specifically expressed in Pl cells and two transmembrane genes specifically expressed in Gr cells were screened out based on their expressions in immune reactions by quantitative PCR analysis.These genes may potentially be used as molecular markers to distinguish between granulocy tes and plasmatocytes in Ostrinia fiurnacalis,and further to clarify the functions of immune hemocytes in cellular immune reaction such as encapsulation and so on.

Establishment and characterization of cell sublines with high and low metastatic potential derived from human osteosarcoma

The most frequent cause of death of patients with osteosarcoma is the metastasis of tumour cells. In spite of successful control of the primary tumour, the mortality of the patients due to metastatic spread is more than 30% within 5 years. 1 Recent studies about osteosarcoma metastatic mechanism are based on osteosarcoma matrilineal cell lines. 2 For further studies of metastatic mechanism of osteosarcoma the establishment of a better metastatic experimental model of osteosarcoma is needed. We isolated and established two cell sublines, with high and low metastatic potentials, respectively, derived from human osteosarcoma MG-63 cell line by cloning in vitro and transplantation in vivo , then analysed and identified their biological characteristics.

INFLUENCE OF IMMUNE STATUS OF THE IMMUNE DEFICIENT MICE ON THE METASTATIC PHENOTYPES OF THE HETEROGENEOUS CLONAL SUBLINES OF HUMAN LUNG GIANT CELL CARCINOMA

By using cell cloning technique, 4 sublines (A,C,D,E) were isolated from a cell line of human lung giant cell carcinoma (PLA-801). After subcutaneous inoculation in T-cell deficient BALB/c nude mice, the incidence of tumor growth and spontaneous metastasis were the highest in subline D, moderate in sublines A and E, and lowest in subline C. Tumor cells of subline C also showed similar low tumorigenicity in another T-cell deficient 615/ PB1 nude mice.However, in 615/PB1 beige nude mice with con-genitally combined immune-deficiency in both T and NK cell activity, tumor cells of the rarely metastatic subline C do produce significantly high frequency of tumor growth and spontaneous metastasis.Morphological studies (light microscope, electron microscope and immunohistochemistry) showed rich microfilaments and Vimentin positive in the cytoplasm of metastatic tumor cells. This may imply a possibility that tumor cells differentiate towards the direction favourable to spreading and metastasis.