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 possible mechanism of arsenic trioxide (As2O3) inducing P16 gene demethylation and transcription regulation in the retinoblastoma (RB) Cell Line Y79． Methods The induced growth inhibition of Y79 cell was assayed by MTT; The DNA content of Y79 cell was analyzed by flow cytometry after being exposed to As2O3; the methylation status of the P16 gene in Y79 cell line before and after treatment with As2O3 was detected by the nestedmethylation specific PCR and DNA sequencing; the mRNA of P16,DNA methyltransferases (DNMT3A and 3B)gene were determined by RT-PCR． Results As2O3 was able to inhibit the growth of Y79 cell and increase the cell number in G0-G1 phase；P16 gene was not expressed in Y79 cell line and As2O3 can induce itrsquo;s mRNA expression；after 48 hour disposal of As2O3，the methylation levelof P16 gene was apparently attenuated in Y79 cell line,the expression of DNMT3A and DNMT3B was obviously down-regulated． Conclusions P16 gene is the hypermethylation in the retinoblastoma cell line Y79, and As2O3 can inhibite the methylation of P16 gene and upregulate the expression of p16 gene mRNA which inhibits the proliferation of Y79 cell by inducing the G0-G1 arrest, by inhibiting the expression of DNA methyltransferases.
We have studied the radiosenstivity of retinoblastoma cell [inc: HXO Rb~4,and found that the ceil growth reduced markedly after being treated by 3GyT-ray. From both clone for mation method and MTT assay,we identify that HXO-Rb44 cell is radiosensitive to T-ray.Oxygen can increase the radiosensitivity of HXO-Rb44 cell, but decrease the repair of sublethal damage.Oxygen enchaneement ratio(OER)is 2.77~3.01.
（Chin J Ocul Fundus Dis,1994,10:217-219）
Objective
To investigate the correlation of expression of Fas/Fas ligand (FasL) and apoptosis in retinoblastoma (RB)．
Methods
The expression and distribution of Fas/FasL were detected by using immunohistochemical staining in 32 cases of RB． Light microsc opy (32 cases), electron microscopy (4 cases) and TdT mediated biotin-d UTP nick-end labeling (TUNEL) (12 cases) were used to study apoptosis in RB．
Results
Apoptotic RB cells mostly located at RB regress area． Chromatin margination and apoptotic bodies were found in RB． TUNEL posi tive labeling cells especially located in tumor regress area． Positive immunola beling for Fas and FasL was found in all RB specimens． There was a highly signi ficant and positive correlation between the expression of Fas/FasL and apoptotic indices (AI) (Plt;0.01 or 0.001)．
Conclusion
The results suggest that apoptotic cell death is prevalent in RB and it may be one type of the most dominant cell death． Fas system may play an important role in oncogenesis and progression of RB, and the up-regulation of Fas system expression might induce RB cell apoptosis．
(Chin J Ocul Fundus Dis, 2001,17:21-23)
Objective A short-term observation study of ocular surgery with or without systemic chemotherapy to treat retinoblastoma (RB). Method The clinical data of 66 RB cases treated at Beijing Tongren Hospital from August 2006 to September 2007 were retrospective reviewed.All patients received ultrasound (B scan/CDI), radiology examination (CT scan/MRI) and RetCam retina examination, and classified according to the International Intraocular Retinoblastoma Classification (IIRC) method. Focal therapies (include laser and cryotherapy) were applied to Group A, systemic chemotherapy (CCTV protocol, Cyclosporine, Carboplatin, Teneposide and Vincrinstine) plus ocular surgery (include focal therapy, enucleation and orbital exenteration) to Group B, C, D and E. Patients were followedup for more than 6 months. Result Of 66 cases (36 male/30 female), 16/66 cases were bilateral RB and 50/66 were unilateral. Follow up period was from 6 to 13 months (mean time 8.6 month). According to IIRC, there were 5 eyes in Group A, 6 eyes in Group B, 5 eyes in Group C, 15 eyes in Group D and 51 eyes in Group E( include extraocular disease). 22/82 eyes were conserved at the end of follow up, including 5/5(100%) of group A, 6/6(100%) of group B, 5/5(100%) of Group C, 4/15(26.7%) of Group D and 2/51(3.9%) of Group E. 5/66 (7.6%) patients died during this period, they all were in Group E. Conclusion Ocular surgery combined with systemic chemotherapy is an effective method to treat retinoblastoma. The consequences depends on the classification with higher conservative rate of eyeballs in early and middle stage (Group A, B, C), and lower rate in late stage (Group D and E).
Objective To observe the expression of matrix metalloproteinase（MMP-2, MMP-9 and vascular endothelial growth factor (VEGF) in retinoblastoma (RB) and its relationship with the differentiation and optic nerve infiltration of RB.Methods Forty paraffin specimens of pathological confirmed RB were studied. They were divided into differentiated group (15 cases) and undifferentiated group (25 cases) , optic nerve infiltration group（13 cases） and without optic nerve infiltration group（27 cases）. The expression of MMP-2, MMP-9 and VEGF were detected by immunohistochemistry, their relationships with the differentiation and optic nerve infiltration were also analyzed.Results The positive rate of MMP-2, MMP-9 and VEGF expression in 40 RB cases were 52.5％，57.5％ and 72.5% respectively．The expression of MMP-2, MMP-9 and VEGF in the undifferentiated group were significantly higher than those in the differentiated group (chi;2=9.037, 9.253, 8.095; P＜0.05). The expression of MMP-2, MMP-9 and VEGF in RB with optic nerve infiltration group were significantly higher than those in RB without optic nerve infiltration group (chi;2=11.045,10.243, 8.956；P＜0.05). The expression of MMP-2，MMP-9 had a positive correlation with the expression of VEGF in RB (r=0.126,0.314；P＜0.05). Conclusions MMP-2, MMP-9 and VEGF expressed in RB tumor tissues. The expression of MMP-2, MMP-9 has a positive correlation with the expression of VEGF. The levels of MMP-2, MMP-9 and VEGF expression are related to optic nerve infiltration of RB cells.
ObjectiveTo evaluate the efficacy of intra-arterial chemotherapy (IAC) for advanced retinoblastoma (RB) after failure of intravenous chemotherapy (IVC).
MethodsFifteen eyes of 13 patients with advanced RB were treated with IAC (1-5 cycles) after failure of IVC (2-8 cycles). The patients included 10 boys and 3 girls, with the mean age of (15.67±8.16) months. Six patients had bilateral RB and 7 patients had unilateral RB. There were 14 eyes (93.33%) in stage D, 1 eye (6.67%) in stage E according to the International Classification of intraocular retinoblastoma. The main reasons for failure of IVC were recurrent primary tumor in 3 eyes (20.00%), subretinal seeds recurrence in 9 eyes (60.00%), viable vitreous seeds in 2 eyes (13.33%) and poor response of primary tumor in 1 eye (6.67%). The mean interval between IVC completion and IAC start was 3 months. The mean follow-up was 19 months (ranged from 3 to 52 months).
ResultsAfter IVC and secondary IAC, the retinoblastoma and seeds were regressed in 12 eyes (80.00%). Three eyes required enucleation for severe vitreous seeds, subretinal seeds recurrence and primary tumor recurrence. There was no evidence of metastasis in any case.
ConclusionIAC can achieve high global salvage rate (80.00%) for patients with advanced retinoblastoma after failure of IVC.
Objective：To observe the therapeutic ef fect of chemoreduction treatm ent combined with local focal therapy for advanced intraocular retinoblastoma (R B).
Methods：Thirteen eyes of nine patients with RB underwent c hemoreduction tr eatment combined with local cryotherapy and (or) transpupillary thermotherapy (TTT), and the clinical data of the patients were retrospectively analyzed. The vi ncristine, etoposide, and carboplatin (VEC) were used in the chemoreduction trea tment. The average followup duration was 15.3 months.
Results：All of the 13 e yes with RB had favorable initial reaction in the treatment of chemoreduction. A fter the first period of chemotherapy, the largest diameter of the tumor fundus decreased 37.2%, and the tumor thickness averagely reduced 46.7%. The subretinal fluid was absorbed completely or partially in 6 eyes (6/8); vitreous and subret inal seeds reduced, disappeared or calcified in 10 (10/11) and 11 eyes (11/11), respectively. During the treatment and in the followup duration, 8 eyes (8/13) had new tumors and (or) recurrences. Finally, 2 eyes (2/13) were enucleated whil e 11 eyes (11/13) were saved in which 8 (8/11) recovered or remained good visual acuity. None of 9 patients had serious side effects of chemotherapy like leucoc ythemia, functional damage of liver and kidney, and dysacousia.
Conclus ions：Chem oreduction treatment has well initial effect on advanced RB. Chemoreduction trea tment combined with local treatment may effectively control the retinal tumor, s ubretinal seeds and vitreous seeds within a shortterm duration. The evaluation of longterm effect of the treatment needs further observation.
Intra-arterial chemotherapy (IAC) is an interventional treatment for retinoblastoma (RB) which infuses the chemotherapeutic agents through ophthalmic artery using microcatheters to control the tumor. Compared with systemic chemotherapy, IAC could significantly increase the globe salvage of advanced and recurrent RB without serious adverse event. Due to the absence of systemic absorption after IAC, no longer effectively kill tumor cell, which have potential danger to leads to inadequate elimination extraocular tumor cells. The most common systemic complications following IAC is myelosuppression; local ocular toxicities include eyelid edema, delacrimation, blepharoptosis, vitreous hemorrhage, retinal artery obstruction. During the last 10 years of clinical application, IAC become one of first-line treatment for intraocular RB. However, at present, there is still a lack of randomized controlled multicenter studies and long-term follow up of IAC.
Children with retinoblastoma (RB) typically survive their cancer due to advances in early diagnosis and treatment. Extraocular invasion and metastasis, and secondary malignant tumor carry a very high mortality rate. Prerequisites for metastasis include tumor initiating capacity, altered cellular adhesion and cell motility, resistance to extracellular death signals and disruption of the basement membrane and extracellular matrix. All those changes can be determined by the cell of origin and the genetic instability of the tumor, responding to the multiple layers of pressure such as hypoxia, from the tumor microenvironment or niche. The interaction between tumor cells and the tumor stroma is regulated by several metastasissuppressor proteins and microRNA. This knowledge has important implications for our understanding and the treatment of extraocular spreading of RB.
