Non-
melanoma skin cancer is one of the major ailments in the United States. Effective drugs that can cure
skin cancers are limited. Moreover, the available drugs have toxic side effects. Therefore,
skin cancer drugs with less toxic side effects are urgently needed. To achieve this goal, we focused our work on identifying potent lead compounds from marine natural products. Five lead compounds identified from a class of
pyrroloiminoquinone natural products were evaluated for their ability to selectively kill
squamous cell carcinoma (SCC13)
skin cancer cells using an MTT assay. The toxicity of these compounds was also evaluated against the normal human keratinocyte HaCaT cell line. The most potent compound identified from these studies, C278 was further evaluated for its ability to inhibit
cancer cell migration and invasion using a wound-healing assay and a trans-well migration assay, respectively. To investigate the molecular mechanism of cell death, the expression of apoptotic and autophagy
proteins was studied in C278 treated cells compared to untreated cells using western blot. Our results showed that all five compounds effectively killed the SCC13 cells, with compound C278 being the most effective. Compound C278 was more effective in killing the SCC13 cells compared to HaCaT cells with a two-fold selectivity. The migration and the invasion of the SCC13 cells were also inhibited upon treatment with compound C278. The expression of pro-apoptotic and autophagy
proteins with concomitant downregulation in the expression of survival
proteins were observed in C278 treated cells. In summary, the marine
natural product analog compound C278 showed promising anticancer activity against human
skin cancer cells and holds potential to be developed as an effective
anticancer agent to combat
skin cancer.