BACKGROUNDRetinocytoma (RB) is a very common intraocular malignant tumor during infancy. Chemotherapy has gradually been used as the first-line treatment for intraocular RB in recent years. In this study, Livin and PTEN expressions were observed in the RB tissue, along with the growth-inhibiting and apoptosis-induced effects of topotecan (TPT) on RB HXO-Rb44 cell strain. This study aimed to investigate the antigrowth effects of TPT on RB cell strain HXO-Rb44.

METHODSMax-Vision(TM) rapid immunohistochemistry was adopted to detect Livin and PTEN expressions in the normal retina and in RB, and their relationship with RB clinicopathologic features was analyzed. Human RB cell strain HXO-Rb44 was cultivated and passaged. MTT method was used to measure the survival rates of HXO-Rb44 cell strains under various TPT concentrations. IC50 values were calculated. Flow cytometry was used to detect the effects of various TPT concentrations on HXO-Rb44 cell apoptosis. Western blotting was used to detect the differences of Livin and PTEN protein expressions during cell apoptosis.

RESULTSThe positive expressions of Livin and PTEN in the RB group were obviously different from those in the normal control group. In RB tissue, Livin expression was relevant to PTEN expression. TPT could significantly induce the occurrence of cell apoptosis and had a dependent relationship with drug concentration. Livin and PTEN expression levels varied with the extension of the effect time of TPT based on Western blotting analysis.

CONCLUSIONSLivin and PTEN have high and low expression levels in the RB tissue, respectively. Both of them have key roles in RB occurrence and development. TPT could induce human RB cell strain HXO-Rb44 cell apoptosis, and its mechanism is associated with the inhibition of Livin and PTEN expressions.

Adaptor Proteins, Signal Transducing ; analysis ; Apoptosis ; drug effects ; Cell Line, Tumor ; Child ; Child, Preschool ; Dose-Response Relationship, Drug ; Female ; Humans ; Infant ; Inhibitor of Apoptosis Proteins ; analysis ; Male ; Neoplasm Proteins ; analysis ; PTEN Phosphohydrolase ; analysis ; Retinal Neoplasms ; drug therapy ; pathology ; Retinoblastoma ; drug therapy ; pathology ; Topoisomerase I Inhibitors ; pharmacology ; Topotecan ; pharmacology

Objective To investigate the current condition of Keshan disease(KD), and inner and outer environmental selenium (Se) levels in Shandong Province, in order to provide scientific evidence for the research, prevention and control work. Methods Inhabitants from 20 villages of 8 counties in KD endemic areas were selected as subjects undergoing general physical examination and electrocardiogram (ECG). Suspicious cases were followed up by chest X-ray radiographs. Meanwhile the Se contents in hair, wheat, corn and sweet potato were measured. Results Ninety one patients with KD, including 82 with latent KD and 9 with chronic KD, were screened out of 2613 inhabitants. The total incidence of KD was 3.48% (91/2613), while the incidence of latent and chronic KD was 3.14%(82/2613) and 0.34%(9/2613) respectively. No new cases of acute or sub-acute KD were found. A total of 368 abnormal ECCs were discovered and the rate of abnormal ECG detected among surveyed population was 14.08% (368/2613). Out of 113 suspects who took X-ray, 57 cases had cardiomagaly. In 217 samples of hair, 228 samples of wheat, 214 samples of corn and 190 samples of sweet potato that were collected, the Se contents were determined by fluorescence. The average Se content in hair, wheat,corn and sweet potato were (0.406±0.090), (0.026±0.009), (0.023±0.010), (0.024±0.006)mg/kg respectively. Conclusions Current condition of KD in Shandong Province remains relatively stable. Se content was increased in the hair, nearly achieving the level in normal areas, but remains low in food.