# Dacarbazine as a Positive Control in Melanoma Cell Lines (A375, SK‐MEL‐103, 1205Lu) and a Human Ex Vivo Skin Model

## TL;DR

The study tested dacarbazine's toxicity on melanoma and skin cells, finding it effective as a control for drug toxicity tests.

## Contribution

The study introduces dacarbazine as a reliable positive control for toxicity testing in melanoma and skin cell models.

## Key findings

- Dacarbazine showed high toxicity in A375 melanoma cells at all concentrations over 72 hours.
- Skin explants showed preserved structure and no apoptosis after dacarbazine exposure.
- Immortalized skin cells showed no toxicity at tested concentrations.

## Abstract

One important step for evaluating and selecting a drug is toxicity studies, which are responsible for eliminating molecules that are considered promising for treating a certain disease based on their effectiveness in clinical studies, but are unsafe to go to the pharmaceutical market. We proposed an evaluation of dacarbazine as a positive control in toxicity effects in the context of macro‐ and micro effects represented by tissue and cell responses. A resazurin assay is used to evaluate cytotoxicity in cells (melanoma cells A375, Sk‐Mel‐103, and 1205Lu; immortalized skin cells HaCat and 3T3), and hematoxylin/eosin staining and TUNEL staining are used in skin explants. There is no toxicity demonstrated in the immortalized cells at the studied concentrations, whereas in the melanoma cells, A375 is the most sensitive to dacarbazine, with a high toxicity at all concentrations over 72 h (p < 0.05), Sk‐Mel‐103 showed toxicity effects only at 200 µg/mL, and 1205Lu showed no evidence of toxicity. Histological data showed that the entire skin structure of the explants is preserved, and no apoptotic cells are observed. Thus, we can conclude that cell lines behave differently when exposed to a drug, in this case Dacarbazine proved to be a good control for toxicity tests.

The work seeked to demonstrate the drug Dacarbazine as a positive control for toxicity tests in immortalized skin cells (keratinocytes and fibroblasts) and in different neoplastic cell lines, through the assay with resazurin. In addition, an alternative model to replace animals in experimental studies, using skin explant culture (hOSEC ‐ human organotypic skin explant culture) which has been an interesting model for the study of the effect of drugs on various processes of skins, such as wound healing, inflammatory processes, malignant transformation, stress, aging and screening tests.