High mobility group (HMG) proteins are the most abundant group of chromatin non-histone proteins. This family is composed of four major variants, including HMGB1, HMGB2, HMGB3 and HMGB4. As a highly evolutionary conserved protein, HMGB1 is the most studied and important member of this group. DAUNOMYCIN is a potent chromatin-binding antitumor drug belonging to the family of anthracycline antitumor drugs. In this work, HMGB1 was purified from rat liver and incubated with various concentrations of DAUNOMYCIN and then its binding to DAUNOMYCIN was investigated, using equilibrium dialysis and circular dichroism spectroscopy techniques. The Scatchard plot obtained from the equilibrium dialysis study exhibited positive cooperative binding behavior and the occurrence of a negative Gibbs free energy (DGo = -6.57 Kcal/M), suggesting that the interaction process was exergonic. Association (Ka) and dissociation (Kd) constants were also determined (Ka: 7.71 ´ 104 M-1, Kd: 1.3 ´ 105 M). According to the circular dichroism data, upon addition of various concentrations of the drug, secondary structure of HMGB1 was altered in a dose dependent manner. Prediction of secondary structure of HMGB1 using relevant software showed that upon binding of DAUNOMYCIN to HMGB1 the alpha-helical content of the protein was increased. Summing up, the results suggest that DAUNOMYCIN binds to HMGB1 protein and this binding may influence HMGB1-DNA interaction followed by DNA-dependent activities of the protein in the cell.

Purpose: To compare the success rate of adjunctive 5-fluorouracil (5-FU) and low molecular weight heparin (LMWH), and DAUNOMYCIN in combination with triamcinolone during vitrectomy in eyes with retinal detachment (RD) and proliferative vitreoretinopathy (PVR).Methods: In this prospective randomized clinical trial, 69 eyes from 69 patients with RD and PVR (grade B or C) randomized to 3 groups. Group 1: received 5-FU and LMWH (200 microgram/ml 5-FU and 5 IU/ml LMWH, Fragmin); group 2: received DAUNOMYCIN (0.5 mg) in 500 cc infusion fluid; and group 3: control group. In all patients, 0.1 cc intravitreal triamcinolone was used during vitrectomy. The patients visited on day 1, week 1, month 1, 3 and 6. Best corrected visual acuity (BCVA) and retinal status compared in the 3 groups.Results: Complete data were available for 60 out of 69 patients. Thirty five patients (58.3%) were male and 25 patients (41.7%) were female. The patient age range was 19-84 years and the mean age was 49. The groups did not have significant difference in age, sex, duration of detachment, severity of PVR, preoperative visual acuity (V/A), lens status, type of tamponade and encircling band and buckle. Postoperative V/A and retina status also was the same in the 3 groups.Conclusion: Perioperative infusion of 5-FU, LMWH and DAUNOMYCIN does not significantly increase the success rate of patients with RD and PVR comparing to control group. Although visual acuity improvement and retina reattachment rate in group 1 and 2 were better than control group, but statistical analysis failed to show significant difference between the 3 groups.