The Chinese human hepatocellular carcinoma cell SMMC7721 has been analysed by flow cytometry, Southern blotting and Western blotting. The results indicated that SMMC7721 cell is a hypoploid cell with a 0.81 DNA index, and that SMMC7721 cell has internal deletion in the 5'-end of its Rb gene and has no Rb gene product (Rb protein). The normal Rb cDNA has been inserted into a retrovirus vector DOL and introduced into SMMC7721 cells by electrporation transfection technique.About 75% of transfected SMMC7721 cells have been killed by Rb gene product. The remain 25% cells are alive as exogenous Rb gene has been mutationally inactivated. （Chin J Ocul Fundus Dis,1994,10:21-24）
A review of 426 patients with retinoblastoma(RB)who presented to Eye Hospital of Zhongshan Ophthalmic Center from 1966 to 1991 showed that 81(19.01%)patients were more than or equal to 5 years of age(median age 6.95 years)at the time of initial diagnosis.All patients are unilateral except 4 cases who are bilateral.The main presentations included leukocoria,exophthalmos,congertion and pain of the eye,drcreased vision,strabismus,oculare hypertension,vitreous opacity,hypopyon and hyphema,etc.Some atypical presentations in these older patients with RB were discussed and some problems that should be noticed in the diagnosis and management were presented.discussed and some problems that should be noticed in the diagnosis and management were presented. （Chin J Ocul Fundus Dis,1993,9:205-206）
PURPOSE: To produce monoclonal antibodies directed against tumor-associated antigens expressed of retinoblastoma-derived tissue culture cell line SO-RBS0. METHODS:Hybridization was performed and the specificity of the antibody was tested by immunofluorescent and immunohistochemical methods. RESULTS:Two hybridomas secreted specific monoclonal antibody against retinoblastoma cells were produced ,and the isotype of the monoclonal antibody was IgG2a CONCLUION:The monoclonal antibodies were specific and highly active against retinoblastoma cells and might be used as immunoconjugate.
PURPOSE:Studying the multidrug resistance(MDR) phenotype occurring in retinoblastoma and its mechanism. METHODS:Using the procedure of stepwise increase in drug concentrations to obtain a retinoblastoma subline which resistant to 600ng/ml vincristine (HXO-RB/VCR). Characteristics of this drug-resistant cell line were investigated by cell counting,drugcontents determinatin,drug sensitivity evaluation and radiation sensitivity test. RESULTS:This cell line was cross-resistant to VDS,MMC VP16，ADM ,DDP,CBP,but not resistant to BCNU and 5-Fu. It was proved to be collaterally sensitive to MTX,and the response to 60Co gamma;-ray was modified slightly in HXO-RB/VCR cell line. Intracellular levels of VCR was much higher in HXO-RB44 cells than in the resistant subline. Those cross-resistances can be reversed by verapamil partly. CONCLUSIONS:MDR and radiation resistance of retinoblastoma can be induced by exposing to VCR and reversed by verapamil partly. （Chin J Ocul Fundus Dis,1997,13: 6-9）
Silver staining technique and computer-assisted image analysis system were used in this study to detect,compare and analyse the nuclear organizer regions(NORs)in human normal retina and retinoblastoma(including differentiated and non-differentiated).The results showed that the mean number of AgNOR per nucleus,the average silver staining area per nucleus and retino of silver staining area to nuclear area in non-differentiated retinoblastoma were much higher than that in differentiated retinoblastoma and normal retina.This might suggest that AgNORs technique and computer-assisted image analysis system have important role in the typing,grading and expectation of progression of retinoblastoma. （Chin J Ocul Fundus Dis,1993,9:202-204）
ObjectiveTo identify the pathogenic mutation in a three generation Chinese family with low penetrance retinoblastoma (RB). Methods8 from 9 family members received complete ophthalmic examinations. DNA was extracted from 6 family members. Using exon combined target region capture sequencing chip to screen the candidate disease-causing mutations. Sanger sequencing were used to confirm the disease-causing mutation. ResultsAmong 9 family members, the proband (Ⅲ2) was bilateral RB, Ⅲ1 was unilateral RB, Ⅲ3 was dead for bilateral RB. Normal fundus were observed in the left eye ofⅢ1 and the eyes of other family members except the proband. Sequence analysis of RB1 gene revealed a missense mutation c.1981C > T (p.Arg661Trp) in the proband and two carriers (Ⅱ2, Ⅱ3), but not in the two normal subjects (Ⅱ1, Ⅱ4). We suspect that the RB penetrance in the family was 50%. ConclusionsThere is a missense mutation c.1981C > T in a Chinese family with low penetrance RB. The RB penetrance is 50%.
Objective To compare the differences of chromosome aberration and Rb 1 gene mutation among 3 cloned cells of SO-Rb50 cell line of retinoblastoma. Methods 1.Three cell cloned strains named MC2, MC3, MC4 were isolated from SO-Rb50. 2. Gbanding and karyotype analysis were performed on the llth passage cells of the 3 cell strains.3.All exons and the promoter region of the Rb gene were detected by PCR-SSCP analysis in tumor cell DNA extracted from the 3 cell strains. Results 1.Both numerical and structural chromosomal aberrations could be observed in these 3 cell strains.Several kinds of structural chromosomal aberrations were observed.The chromosome aberrations in the same passage of different cell strains were different.Aberration of chromosome 13 was rare and the aberration feature was different in the 3 cell strains.Five marker chromosomes were identified.M1,t(1;1)qter-p35∷q24-ter could befound in all cell strains.Two of them M4 and M5,have not been reported in SO-Rb50 cell line previously.2.SSCP analysis of exon 24 showed that MC411 and MC3138 had abnormal band. Conclusions The characteristics of heterogeneity of the original tumor cell line SO-Rb50are still kept during a long-term culture in vitro and the cloned strains had dynamic changes during this period.Aberration of chromosome 13 is not the only cause of RB;aberration of chromosome 1,a commom event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line. (Chin J Ocul Fundus Dis, 1999, 15: 146-148)