Effects of indomethacin on human choroidal melanoma OCM-1 xenografts in nude mouse

Background Choroidal melanoma(CM)is a common form of primary ocular cancer in adults.It is reported that indomethacin has inhibitory effect on many tumor in vitro and in vivo,but whether it can inhibit the growth of CM has not been published. Objective This study was to investigate the anti-tumor activity of indomethacin on the growth of human CM OCM-1 cell xenografts in nude mice. Methods OCM-1 cells were subcutaneously implanted on 24 SPF female BALB/C.nu/nu nude mice to establish ectopic models of human CM.The nude mice with the tumor 5 mm were randomly divided into 4 groups:untreated group,normal saline solution(NS) group,indomethacin 1 ms/kg group,indomethacin 2 ms/kg group.The 1 mS/kg or 2 ms/kg indomethacin was intraperitoneally injected for 14 consecutive days in indomethacin 1 ms/kg group and indomethacin 2 me/kg group respectively.and 0.2 ml of 2%NS-DMSO was used at a same way in the NS group.No any agent was used as the untreated group.The volume and weight of implanted tumor as well as inhibitory rates of indomethaein on tumor were calculated.The expression of ki67 and survivin proteins were measured with immunohistochemistry,and the expression of survivin mRNA in CM was assessed by RT-PCR. ResuIts The tumor of indomethacin treatment group was reduced in volume and weight with a significant difference between treatment group and control group as well as indomethacin 1 ms/ks group and indomethacin 2 ms/kg group(P＜0.05).The inhibitory rate of indomethacin 1 ms/kg and 2 ms/kg for tumor was 22.86%,48.00%respectively.The prolifiration index (PI)of ki67 in these 4 groups were (76.73±3.34)%,(73.30±2.95)%,(55.97±2.24)%,(32.87±2.91)%respectively,and significant difference was found in PI between indomethacin 2 mg/kg group and untreated group or NS group(P＜0.05),but there was not significant difference between indomethacin 1 mg/kg and 2 ms/kg group(P＞0.05).Compared with the control group,the indomethacin treatment groups showed the decreased expression of survivin protein and mRNA,and significant difference was found between indomethaein 2 ms/kg group and untreated group or NS group(P＜0.05),however,no significant difference was found between indomethacin 1 mg/kg and 2 mg/kg group(P＞0.05). Conclusion Indomethacin inhibits the growth of CM in nude mice through inhibiting the expression of survivin in the tumor and accelerating cell apoptosis and inhibiting tumor cell proliferation. Key words: lndomethacin;  Choroidal melanoma;  Ki67;  Survivin;  Apoptosis