The pGenesil-1-Beclin1 eukaryotic expression vectors were constructed to establish an SH-SY5Y cell line stably expressing shRNA-Beclin1. The shRNA was connected to pGenesil-1 to construct the recombinant plasmid pGenesil-1-Beclin1, which was transformed into JM109 E.coli. Positive clones were identified by digestion with restriction endonuclease and DNA sequencing. SH-SY5Y cells were cultured by the conventional method. The pGenesil-1-Beclin1 and pGenesil-1 plasmids were transfected into SH-SY5Ycells, and the cells were screened by G418 until the stable G418-resistant monoclonal cells were acquired. Beclin1 mRNA and Beclin1 protein were detected by RT-PCR and Western blot analysis respectively. The results of restriction endonuclease analysis and DNA sequencing confirmed the correct construction of the eukaryotic expression vector pGenesil-1-Beclin1. Two SH-SY5Y transfected cell lines were successfully selected. Compared with the control group, RT-PCR and Western blot showed that the expression of Beclin1 mRNA and protein were down regulated 71.28%±1.45%(P<0.05)and 75.50%±2.63%(P<0.05), respectively. The results indicated that the eukaryotic expression vector pGenesil-1-Beclin1 was successfully constructed and the SH-SY5Y cell lines with inhibited Beclin1 expression were established. It provides a useful cell model for studying the biological function of Beclin1.
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)
The debate on the cell of origin of human retinoblastoma lasted for more than one century. In the recent issue of ldquo;cellrdquo;, David Cobrinikprime;s group shows that L/M cone precursors are the most likely answer as they have an intrinsic circuitry, including murine double minute 2 (MDM2), Nmyc, the nuclear receptors retinoid X receptor and thyroxine receptor 2, making them extremely sensitive to transformation following retinoblastoma gene inactivation.
Objective To explore the expression of survivin gene in retinoblastoma (RB) and its relationship with the stages and histodifferentiation degree of RB and the expression of p53、bcl-2 proteins. Methods Expression of survivin, p53 and bcl-2 proteins in 38 RB conventional paraffin samples were detected with survivin, p53 and bcl-2 monoclonal antibodies respectively by immunohistochemical assay. The expression of survivin of normal retina in 6 control samples was observed. Results In 38 cases of RB, positive expression of survivin was found in 20 (52.6%); while none of the 6 normal retinal tissue expressed survivin, which had significant difference between the two group (P＜0.05). The positive expression of survivin did not correlate with sex of patient, disease stages and histological type (P＞0.05). In 38 RB cases, positive expression of p53 was in 25 with the rate of 65.8%, and of bcl-2 in 18 with the rate of 47.4%. The positive-expressed rates were much higher in positive-expressed p53 and bcl-2 group than those in the negative-expressed p53 and bcl-2 group(P＜0.05). Conclusion The increase of the expression of survivin implies that it may take part in the occurrence and development of RB; the interaction among survivin, p53 and bcl-2 may participate in the access and the course of RB. (Chin J Ocul Fundus Dis，2004，20：215-217)
ObjectiveTo detect the level of serum melanoma-inbibiting activity (MIA) in patients with uveal melanomas, and investigate the value of MIA in diagnosing and inspecting uveal melanomas.MethodsEnzyme-linked immunosorbent assay (ELISA) was used to detect the concentrations of MIA in peripheral serum of 27 patients with uveal melanoma, 6 with melanocyte tumor, 7 with other ocular tumors and 16 healthy individuals, respectively.ResultsThe concentration of MIA in patients with uveal melanoma was significantly higher than that in the healthy ones (16 individuals) and the patients with adenoma of non pigmented ciliary epithelium (4 patients), retinoblastoma (2 patients), and retinal angioma 91 patient). The concnetration of MIA in patients with uveal melanoma without scleral infiltration or remote metastasis was obviously lower than that in the patients with scleral infiltration or remote metastasis, but didn′t differ much from which in the patients with melanocyte tumor. In the patients with uveal melanoma without infiltration or remote metastasis, there was no significant difference of MIA level between patients with spindle cell and mixed and epithelioid cell.ConclusionThe level of serum MIA may be an effective index in diagnosing uveal melanoma, which can monitor the metastasis of uveal melanoma.(Chin J Ocul Fundus Dis, 2005,21:153-155)
Objective To analyze the BEST1 gene mutations and clinical features in patients with multifocal vitelliform retinopathy (MVR). Methods This is a retrospective case series study. Five MVR families with MVR, including 9 patients and 10 healthy family members were recruited. Clinical evaluations were performed in all MVR patients and their family members, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), refraction, slit-lamp examination, 90 D preset lens examination, gonioscopy, color fundus photography, optical coherence tomography (OCT), fundus autofluorescence (AF), ultrasound biomicroscopy (UBM) and axial length measurement. Electro-oculogram (EOG) was performed in 12 eyes and visual field were performed in 13 eyes. Peripheral blood samples were collected in all subjects to extract genomic DNA. Coding exons and flanking intronic regions of BEST1 were amplified by polymerase chain reaction and analyzed by Sanger sequencing. Results Among the 5 MVR families, 3 probands from three families had family history, including 1 family had autosomal dominant inheritance pattern. Two patients from 2 families were sporadic cases. Screening of BEST1 gene identified four mutations, including three missense mutations (c.140G>T, p.R47L; c.232A>T, p.I78F; c.698C>T, p.P233L) and 1 deletion mutation (c.910_912del, p.D304del). Two mutations (p.R47L and p.I78F) were novel. The BCVA of affected eyes ranged from hand motion to 1.0. The mean IOP was (30.39±11.86) mmHg (1 mmHg=0.133 kPa). The mean refractive diopter was (-0.33±1.68) D. Twelve eyes had angle-closure glaucoma (ACG) and 4 eyes had angle closure (AC). EOG Arden ratio was below 1.55 in all patients. The mean anterior chamber depth was (2.17±0.29) mm. Visual field showed defects varied from paracentral scotoma to diffuse defects. The mean axial length was (21.87±0.63) mm. All MVR patients had multifocal vitelliform lesions in the posterior poles of retina. ACG eyes demonstrated pale optic disc with increased cup-to-disc ratio. OCT showed retinal edema, extensive serous retinal detachment and subretinal hyper-reflective deposits which had high autofluorescence in AF. The genetic testing and clinical examination were normal in 10 family members. Conclusions MVR patients harbored heterozygous mutation in the BEST1 gene. Two novel mutations (p.R47L and p.I78F) were identified. These patients had clinical features of multifocal vitelliform retinopathy and abnormal EOG. Most patients suffered from AC/ACG.
Objective To observe the mutation frequency and the characteristics of rentinitis pigmentosa (RP)1 gene in the Chinese patients with autosomal dominant (AD) RP or sporadic RP (SRP), and to evaluate their potential effects on the pathogenesis of RP. Methods Fifty-five members from 7 Chinese families with ADRP, 30 patients with SRP, and 75 healthy adults were recruited. Polymerase chain reaction (PCR) and direct DNA sequencing were used to detect the sequence mutation in the entire coding region and splice sites of RP1 gene. Univariate analysis and multivariate analysis were used to detect the effect of RP1 gene mutation sites on RP. Results Four coding sequence variants were detected in the codes of 852，872，921 and 939 at the exon 4 of RP1 gene. The R872H alteration, which was found in both ADRP families and patients with SRP, showed positive correlation with RP confirmed by the multivariate logistic regression analysis. The P903L alteration was only found in ADRP families but not in the patients with SRP or the healthy adults. Conclusions The R872H alteration in the RP1 gene is likely to increase the risk of RP, and may be a susceptible gene of RP. Whether the P903L alteration is a diseasecausing factor needs to be further studied.
Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
ObjectiveTo reveal the pathogenic mutation in a three-generation Chinese family with autosomal dominant familial exudative vitreoretinopathy (FEVR). MethodsThree patients and a healthy spouse from the index family with FEVR were recruited. The proband was a 5 years old boy. His mother and grandpa were presented with typical FEVR presentations, while his father with normal ocular fundus. DNA was extracted from peripheral blood samples taken from all four participants. All coding and exon-intron boundary regions of five targeted genes, including NDP, FZD4, LRP5, TSPAN12 and ZNF408 were amplified with polymerase chain reaction and sequenced using direct sequencing. In silico analyses were applied to determine the conservation of the mutation site, pathogenic effect and the potential protein crystal structural changes caused by the mutation. ResultsFZD4 c.478G > A, a susceptible mutation was found after four high frequency mutation sites which MAF values were higher than 0.001 was filtered among 5 single nucleotide variations detected in four participants, leading to the residue 160 changing from glutamate to lysine (p.E160K). Co-segregation analysis between genotypes and phenotypes revealed FZD4 p.E160K as the disease-causing mutation for this family. Conservational analysis suggested that this mutation site was highly conserved among all tested species. Functional analysis predicated that this mutation may be a damaging mutation. Crystal structural analysis also indicated that this mutation could lead to the elimination of the hydrogen bond between residue 160 and asparagine at residue 152, thus altering the tertiary structure of the protein and further impairing the protein function. ConclusionOur study demonstrates FZD4 p.E160K as a novel pathogenic mutation for FEVR.
Purpose To observe the expression of proliferating cell nuclear antigen（PCNA）and bcl-2 of cultured human retinal pigment epithelial cells（RPE）． Methods SABC techniques were applied for immunocytochemical staining of cultured RPE with mouse anti-human PCNA monoclonal antibody and rabbit antihuman bcl-2 antibodies． Results 31.2% and 50.6% cultured cells were positive to anti-human PCNA at 24h and 48h after seeding，respectively．The positive staining was mottled in the nucleus．positive staining for bcl was seen in 76%to 90% cells as fine granules scattered within the cytoplasm. Conclusion One half of cultured RPE expressed PCNA，indicating that the cells were in phase S of the cell cycle．Positive staining for bcl-2 appeared in much more RPE cells．These biological markers may be associated with the growth activity of cultured RPE． (Chin J Ocul Fundus Dis,1998,14:26-28)