Effect of luteolin on apoptosis and vascular endothelial growth factor in human choroidal melanoma cells

AIM:To investigate the effects of luteolin on apoptosis,the cell cycle,and the expression and secretion of vascular endothelial growth factor(VEGF)in human choroidal melanoma cells(C918 and OCM-1).METHODS:C918 and OCM-1 cells cultured in vitro were treated with various concentrations of luteolin(0,5,10,15μmol/L).Cell growth was observed with an inverted microscope,and cell cycle arrest was detected by propidium iodide(PI)staining using flow cytometry.Apoptosis was detected by Hoechst33342 staining,and apoptosis rate was determined by Annexin V-FITC/PI experiments using flow cytometry.The expression of apoptosis-related proteins Bcl-2,Bax and VEGF was analyzed using Western blots.The levels of VEGF secreted by the cells into the supernatant was analyzed using ELISA.RESULTS:After treating with 5 to 15μmol/L luteolin for 48 h,the fusion degree of C918 and OCM-1 cells decreased,and more floating apoptotic cells appeared.Luteolin treatment increased the G0-G1 phase ratio of the C918 and OCM-1 cells,blocked cell cycle progression,and increased the apoptosis rate of the C918 and OCM-1 cells.Western blot showed that luteolin decreased the expression of Bcl-2 and VEGF in the C918 and OCM-1 cells and increased the expression of Bax protein.The ELISA results showed that 10 to 15μmol/L luteolin decreased the cell secretion of VEGF.CONCLUSION:Luteolin may induce apoptosis by regulating the levels of apoptosis-related proteins in C918 and OCM-1 cells.Luteolin can induce cell cycle arrest,decrease the expression of VEGF.

Expression and significance of factors related to angiogenesis in choroidal melanoma

AIM: To investigate expression of factors related to angiogenesis: HIF-1 alpha, iNOS, COX-2 and VEGF in choroidal melanoma and its clinical significance. METHODS: Fifty samples of choroidal melanoma and 15 samples of melanocytic nevi of the eyelid identified by pathology were collected. Immunohistochemistry SP method was used to examine the expression of HIF-1 alpha, iNOS, COX-2 and VEGF in these samples. The comparison among groups was done by SPSS 13.0 software. RESULTS: The positive expression rates of HIF-1 alpha, iNOS, COX-2 and VEGF in choroidal melanoma group were significantly higher than those in eyelid nevi group (chi(2)= 6.5542, 7.7224, 8.5828, 15.1749). The positive expression rate of VEGF was associated with the tumor size (chi(2)= 10.9194), but was not associated with pathological type (chi(2)=2.0712) and the situation of scleral invasion (chi(2)= 5.4289). The positive expression rate of HIF-1 alpha was associated with the tumor size (chi(2)=7.1216) and pathological type (chi(2)=9.0889), but was not associated with the situation of scleral invasion (chi(2)=3.3586). The positive expression rate of iNOS was associated with the tumor size (chi(2)=9.5503), but was not associated with pathological type (chi(2)=1.9450) and the situation of scleral invasion (chi(2)=2.3810). The positive expression rate of COX-2 was associated with the tumor size (chi(2)=7.2970), but was not associated with pathological type (chi(2)=1.8421) and the situation of sclera! invasion (chi(2)= 0.4018). The expression of HIF-1 alpha, iNOS and COX-2 were significantly associated with the expression of VEGF (r = 0.9429, 1, 0.9857). The expression of COX-2 was significantly associated with the expression of iNOS (r=0.9857). The expression of HIF-1 alpha was significantly associated with the expression of COX-2 ( r=0.9857). The expression of HIF-1 alpha was significantly associated with the expression of iNOS (r= 0. 9429). CONCLUSION: The expression of HIF-1 alpha, iNOS and COX-2 protein in choroidal melanoma were higher and may relate to angiogenesis and stimulate tumor growth. Determination of HIF-1 alpha, iNOS and COX-2 may be helpful for the diagnosis and therapy of this tumor.

Secondary endoresection for previously treated choroidal melanomas with a non-responsive course and persistent exudative retinal detachment

AIM:To evaluate the results and complications of secondary endoresection via pars plana vitrectomy for choroidal melanoma and review the previously reported endoresection studies on the treatment of choroidal melanoma.METHODS:The medical records of 6 patients with choroidal melanoma who underwent secondary endoresection between March 2012 and March 2020 were retrospectively reviewed.The indications for secondary endoresection were progressive or recurrent tumor and severe exudative retinal detachment after previous treatment with plaque radiotherapy/Cyberknife radiosurgery/transpupillary thermotherapy(TTT).RESULTS:Before endoresection,2 eyes had Iodine-125 plaque radiotherapy and TTT,1 eye had Ruthenium-106 plaque radiotherapy and TTT,1 eye had Cyberknife radiosurgery and TTT,1 eye had Cyberknife radiosurgery,and 1 eye had TTT only.Preoperative visual acuity ranged from 20/63 to 20/1600(Snellen) and from 0.5 to 1.9(mean:1.1) on the log MAR scale.The mean tumor base diameters were 9.5×8.7 mm and the mean tumor thickness was 5.4 mm.After secondary endoresection,transient vitreous hemorrhage developed in 2(33.3%) eyes and retinal detachment in 1(16.7%) eye.Cytopathological examination revealed epithelioid cell melanoma in 4(66.7%) eyes and mixed cell melanoma in 1(16.7%).Melanoma cell type was not specified in 1(16.7%) eye.At a mean follow-up of 49.6 mo(range:16-90 mo),mean visual acuity did not improve and 1 eye was enucleated due to tumor recurrence.Final visual acuity ranged from 20/63 to 20/1600(Snellen) and from 0.5 to 1.9(mean:1.2) on the log MAR scale.Two patients with choroidal melanoma developed metastasis and eventually expired.CONCLUSION:Secondary endoresection seems to be an effective treatment option for globe salvage in choroidal melanoma not responsive to conventional treatment and displaying persistent exudative retinal detachment.There was no visual acuity increase among the treated eyes but globe salvage was possible in most cases in this study.

Complications from Plaque versus Proton Beam Therapy for Choroidal Melanoma: A Qualitative Systematic Review

Plaque brachytherapy has been a mainstay of treatment for choroidal melanoma to achieve intraocular tumor control. The most common radioisotopes used for treating smaller sized tumors are Iodine-125 in North America and Ruthenium-106 in Europe. Proton beam radiotherapy is available at a few centers and may also be used to achieve local tumor control. Both plaque and proton beam therapy are known to be associated with a range of complications that may affect visual outcome and quality of life. These include radiation retinopathy, optic neuropathy, neovascular glaucoma and local treatment failure, requiring enucleation. While differences in the rates of these complications have not been well established in the literature for patients treated with plaque versus proton beam therapy for choroidal melanoma, certain geographic regions prefer one treatment modality over the other. The purpose of this qualitative systematic review was to compare and contrast reported complications that developed with plaque and proton beam therapy for the treatment of choroidal melanoma in studies published over a ten-year period. Reported rates suggest that patients with proton beam therapy had potentially higher rates of complications, including vision loss, enucleation, and neovascular glaucoma compared to those with plaque therapy. The rates of optic neuropathy, radiation retinopathy, and cataract formation were widely variable for the two treatment modalities and rates of metastasis and metastasis-free survival appeared similar with both treatments. The most common reported predictors of ocular complications following both types of therapy were tumor distance from the optic nerve, tumor thickness, and radiation dose, suggesting that inherent tumor characteristics play a role in visual prognosis.

Acute Pulmonary Embolism Caused by Local Resection of Choroidal Melanoma

Uveal melanoma is the most malignancy in adults, with 6-7 cases/million people.^-~j common primary ocular an annual incidence of The choroid is the most common site of involvement occurring in more than 90% patients.TM We conducted a retrospective study for uveal melanoma at Yongren Eye Center from 1997 to 201 I. A total of 682 cases of uveal melanoma were recorded. Among them, 176 （25.8%） cases received local resection surgery. Most of them survived after surgery and had good recovery. However, life-threatening complication of acute pulmonary embolism （APE） occurred in 3 choroidal melanoma patients shortly after surgery. Till now, to the best of our knowledge, there are few reports of severe postsurgical complications of choroidal melanoma.

Combination of oridonin and TRAIL induces apoptosis in uveal melanoma cells by upregulating DR5

AIM:To investigate the inhibitory effect of the combined use of tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)and oridonin on choroidal melanoma cell lines,and to explore its underlying mechanism.METHODS:MUM-2B and C918 cells were treated with different concentrations of TRAIL and oridonin,and MTT assay used to evaluate the inhibition rate of the two compounds on cells.Then,the cell cycle distribution and apoptosis were detected by flow cytometry,and changes in apoptosis-related proteins such as death receptor 5(DR5),a-caspase-3,and x-linked inhibitor of apoptosis protein(XIAP)were detected by Western blot.MUM-2B cells were transfected with si-DR5,which interfered with the expression of the DR5 gene.MTT and Western blot assay were used to detect cell activity and apoptosis-related proteins.RESULTS:When TRAIL and oridonin were simultaneously administered to the MUM-2B cells,the apoptosis rate was significantly higher than that by the two drugs individually.However,the effect of combined use of TRAIL and oridonin on C918 cells was not significantly different from that used alone.Cell cycle analysis showed that TRAIL and oridonin could induce G2/M arrest in MUM-2B cells.The Western blot results showed that the protein expression levels of the DR5,a-caspase-3,and BAX increased,while the expression levels of the anti-apoptosis-related proteins XIAP and BCL-2 were suppressed when TRAIL and oridonin simultaneously administered to MUM-2B cells.Interfering the expression of DR5 gene in MUM-2B cells could reverse the inhibitory effect of oridonin and TRAIL on the proliferation and apoptosis induction of MUM-2B cells.CONCLUSION:The inhibitory effects of oridonin and TRAIL on MUM-2B cells are significantly enhanced when they were administered as a combined treatment,which may ascribe to up-regulation of DR5.