The experiment research of subconjunctival injections with etoposide for the treatment of retinoblastoma mice.
OBJECTIVE
To evaluate the efficacy of subconjunctival injections of Etoposide for retinoblastoma(RB) mice.


METHODS
Twenty-five RB mice were divided into 5 groups for the study(GO-G4). GO for control group received 0.9% sodium chloride injection subconjunctival. G1: 5 RB mice for systemic delivery received 6 systemic administration of Etoposide 150 microg and Cyclosporin A (CSA ) 1.0mg at 3 days intervals, respectively. G2-G4: 5 RB mice in each group received 6 subconjunctival delivery of Etoposide in 50, 75, 150 microg at 3 days intervals, respectively.To observe the changes of the volume of RB in anterior chamber and the part of conjunctiva for injections of chemotherapeutic drugs. All eyes and conjunctiva and scleras of the part for drugs injections were obtained at 6 weeks after experiment for histopathologic examination. The findings under the light microscope were analysed with software to measure the areas of RB in anterior chambers and the tumor inhibition rate.


RESULTS
The volume of RB in anterior chambers for G1 and G2 increase quickly and none of the mice exhibited tumor control. The RB volume increase slowly in G3 and exhibit tumor control in G4. The areas of tumors in GO-G4 are 0.710,0.659,0.634, 0.515,0.235 mm(2), respectively. The rate for tumor inhibition in GO-G4 are 0.0%, 7.18%, 10.70%, 27.43% , 66.90%, respectively. There are statistical significant difference between the G1 and G4 for the volumes of tumors and the rate of tumor inhibition. The pathologic examination of subconjunctiva and sclera for the injective sites showed no pathologic changes.


CONCLUSIONS
There are significant effects for the method of subconjunctival delivery of Etoposide in RB control, demonstrating a positive dose-related relationship. Subconjunctival injection of Etoposide reached better efficacy in controlling and inhibiting RB cells than systemic delivery of Etoposide for the same dose. The pathologic results showed the subconjunctival delivery of etoposide were safety for conjunctiva and sclera. It would be one of effective and safety method of chemotherapy for RB.
Mao
Yuxiang
Y
Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China. Myxdoctor@21cn.com
Zhongyao
Wu
W
Huasheng
Yang
Y
Zheng
Jianliang
J
He
Jianfeng
J
Li
Wei
W
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage*; D003228:Conjunctiva / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005047:Etoposide / Q000008:administration & dosage*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D019572:Retinal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D012175:Retinoblastoma / Q000188:drug therapy* / Q000473:pathology
D000972:Antineoplastic Agents, Phytogenic; D005047:Etoposide