Despite its low incidence, retinoblastoma and its rela ted gene (Rb gene) have attracted some of the most brilliant minds in medicine and biology fi elds over the past years. Great advances have been achieved in the tumoregenesis mechanism and clinical management of retinoblastoma recently. However as always , more questions arise from those results. In order to improve retinoblastoma re search in China, we need to strengthen the communication and cooperation with di ffe rent countries, different institutes and disciplines, and utilize the great reso urces of retinoblastoma patients in China.
Purpose To investigate nucleoside diphosphate kinase (NDPK ) expression of tumor metastasis suppressor gene nm23 in heterotransplanted model of retinoblastoma(RB) in nude mice，and analyse the correlation between the expression of nm23 gene and the formation and progression of heterotran splanted RB． Methods SP immunohistochemical method was used to detect the expression of nm23 gene product NDPK in 20 tumors of heter otransplanted RB model and normal retinal tissue． Results The negative staining of nm23/ NDPK was found in normal retinal tissue , whereas 100% expression rate in RB tumors with positive number of 48.73plusmn;2.37． No statistical significance of the expression of nm23/ NDPK was observed between the intraocular growth phase （I～Ⅲ grade） and invasive phase （ Ⅳ～Ⅴ grade）in heterotransplantedRB tumors． Conclusion The function of nm23 gene as a tumor metastasis suppressor in heterotra nsplanted RB tumors was less prominent ,but it may play a role in carcinogen esis and progrssion of RB and may predict poor prognosis． (Chin J Ocul Fundus Dis, 2001.17:47-49)
Objective To investigate the effect of exogenous Rb gene on the cell cycle of vitreous retinoblastoma (RB) transplantation tumor in nude mouse. Methods Based on establishing vitreous RB transplantation tumor in nude mouse,constructing retrovirus vector of Rb gene PBabe-Rb and transfecing it into the RB transplantation model by liposome Dosper,the change of cell cycle of the RB transplantation tumor by flow cytometry(FCM)was analysed． Results FCM showed that the cells of G1phase of the treated eyes were obviously more than the control eyes with the value of DNA index(DI)and S phase fraction(SPF) decreased by the Rb gene expression. Conclusion The exogenous PBabe-Rb gene can partially suppress the progress of the cell cycle of RB transplantation tumor in vivo. (Chin J Ocul Fundus Dis，2000，16：1-70)
Purpose To estabalish a quantifying model of retinal neovascularization suitable for the study of pathogenesis and therapeutic intervention for the retinal neovascularization． Methods Sixteen one-week-old C57BL/6 mice were exposed to 75% oxygen for 5 days and then to room air and 16 mice of the same age kept in room air as controls.Ink-perfused retinal flatmount was examined to assess the oxygen-induced changes of retinal vessels.The proliferated neovascular response was quantitated by counting the nuclei of endothelial cells of new vessels extending from the retina into the vitreous in 6 mu;m sagittal cross sections． VEGF and bFGF were determined on the cross-sections after immunohistochemcal stain. Results Constriction and closure of the blood vessels were found under the hyperoxia condition,and dilation and proliferation were found under the relatively hypoxia status.There was a mean of 24 neovascular nuclei per cross-section in the oxygen-treated retina and less than 1 nucleus in the control group (P＜0.001).VEGF stain was found ber in the inner retinal layer of oxygen-treated mouse than in that of the controls. Conclusion The quantifying model of retinal neovascularization may fascilitate the further researches of medical intervention and pathogenesis of retinal neovacularization. (Chin J Ocul Fundus Dis，2000，16：213-284)
Objective Molecular cloning of rat retinal degeneration slow(RDS)gene cDNA. Methods Using PolyA+RNA from retina of SD rat as template,a 1555bp positive cDNA band was obtained by RT-PCR and subcloned into pBluescriptⅡKS(+) vector.The cloned fragment was analyzed with restriction endonucleases and sequencing. Results It had been proved that the cloned fragment was rat RDS/peripherin cDNA.Except for the substitute of A1242G and CA1409-1411CCA,the other sequences corresponded to that reported by Begy. Conclusion Rat RDS/peripherin cDNA was obtained.Researches on function of rat RDS/peripherin gene and its role in retinal degeneration are under way. (Chin J Ocul Fundus Dis,1999,15:97-99)