Response of Transformed and Normal Mouse Cell Lines to Anti‐Melanin Compounds, Hyperthermia, and Radiation

Abstract

Five cell lines (one parental, two transformed melanin producing, and two transformed non-melanin producing) were evaluated for the responses to 2- and 4-hydroxyanisole (2HA, 4HA) alone or combined with hyperthermia or radiation. All cells exhibited a non-specific toxic response to the two compounds and the effect was exposure time and concentration dependent and was greater for 4HA compared to 2HA. In addition, the two melanin-producing cell lines were more sensitive, demonstrating specific toxicity to such cell lines. The treatment with either 2HA or 4HA combined with heat and radiation resulted mostly in additive or antagonistic effects, except for one combination of 2HA plus radiation in the melanin-producing R25 cells. Thus, while these compounds may be useful in therapy for pigmented melanomas, combined treatment with radiation is not recommended.

Enhanced Antitumor Effect of Radiation in Combination with Heat-Sensitive Liposome-Encapsulated Drug and Hyperthermia on Murine Tumors.

“…In recent years there has been a renewal of interest in the use of hyperthermia as a treatment modality for melanoma therapy, and research has focused on treatment with the combination of hyperthermia and drugs [33,34]. Raaphorst and Azzam [35] reported the response of transformed and normal cell lines to antimelanin compounds, 2-and 4-hydroxyanisole, alone or combined with hyperthermia or radiation. Treatment of B 16F to melanoma with the combination of hyperthermia, melphalan, and CCNU resulted in progressive delay in tumor growth, reduced metastases, and diminution of proliferative capacity [36].…”