Enhancement of Cytotoxicity of Chemotherapeutic Agents by Buthionine sulfoximine in Retinoblastoma Cell Line

This study was performed to evaluate in vitro cytotoxicity of chemotherapeutic agents in established human retinoblastoma cell line, Y79 and to study the possibility of enhancing the cytotoxicity of chemotherapeutic agents by administration of buthionine sulfoximine(BSO) which lowers the intracellular glutathione(GSH) level. IC50 defined as the concentration which inhibits the cell survival rates to 50% compared with control group was used to evaluate cytotoxicity. Intracellular level after 13.50 adminstration were measured and compared with the level prior to administration of BSO. Doxorubicin, cisplatin, and melphalan showed significant decrease of IC50 by administration of BSO(p0.05). Intracellular GSH level prior to the administration of BSO was 0.931nM/mg protein. After the administration of BSO, they were lowered to 0.095nM/mg protein in both BSO concentrations. Results listed above suggest that cytotoxicity of doxorubicin, cisplatin, and melphalan can be enhanced by ESO. This effect may be mediated by decreased intracellualr level of GSH by BSO.

A Case of Osteosarcoma Developed in a Patient of Untreated Bilateral Retinoblastoma

Retinoblastoma is one of the primary malignant tumors which rarely undergo spontaneous regression. Survival rate from retinoblastoma is in excess of 90%, but the subsequent development of second tumor is an important factor of the long-term prognosis. The authors experienced a case of osteosarcoma developed on left distal femur in a patient of bilateral retinoblastoma which underwent spontaneous regression.

A Clinicopathologic Study of 46 Cases of Eyelid Malignancy

We studied retrospectively 46 patients of primary malignant eyelid tumors who were histologically diagnosed in Korea Cancer Center Hospital from May, 1987 to December, 1994 and followed for 6 months or longer. 46 patients consist of, 22 cases of basal cell carcinoma(47.8%), 10 cases of squamous cell carcinoma(21.7%), 9 cases of sebaceous gland carcinoma(19.6%), and 5 cases of malignant melanoma(10.9%). Our modalities of treatment for eyelid malignancy included excision under frozen-section control, radiotherapy and cryotherapy. In case of regional lymph node metastasis we performed radiation treatment with or without excision of primary tumor and regional lymph node dissection. A case with distant metastasis underwent radiotherapy combined with chemotherapy. Following initial treatment, 4 cases showed recurrence and 3 cases developed regional or distant metastasis. In this study, we emphasize that suspected eyelid malignancy should be histologically diagnosed with biopsy and treated adequately at an early stage to reduce recurrence or metastasis.

Clinical Analysis of Retinoblastoma

We analyzed retrospectively 58 patinets of retinoblastoma for the first, ocular symptoms, gender, family history, funduscopic findings, treatment modalities and results from 1987 to 1993. Fourteen patients were bilateral, forth-four were unilateral, and seventy-two eyes were affected in sum. The average of age of the patients was 25.6 months. Their first ocular symptoms were leukocoria, squint and etc. Three patients were suspected as familial type of retinoblastoma. We claasified the patients according to the affected degree of the retina;over three-fourths of the retina was affected in 34 eyes. We treated them with enucleation, radiation, chemotherapy, episcleral plaque radiotherapy, laser photocoagulation and cryotherapy. After these treatments, orbital recurrence was observed in one case and among the ten eyes treated with eye-conserving treatments, nine eyes are maintained with periodic examination under general anesthesia and the treatment of laser photocoagulation and cryotherapy until now.