Regulatory role of echinochrome A in cancer-associated fibroblast-mediated lung cancer cell migration
Echinochrome A (Ech A), a marine biosubstance isolated from sea urchins, is a strong antioxidant,  and its clinical form, histochrome, is being used to treat several diseases, such as ophthalmic,  cardiovascular, and metabolic diseases. Cancer-associated fibroblasts (CAFs) are a component  of the tumor stroma and induce phenotypes related to tumor malignancy, including epithelial–mesenchymal transition (EMT) and cancer stemness, through reciprocal interactions with cancer cells. Here, we investigated whether Ech A modulates the properties of CAFs and alleviates CAF-induced lung cancer cell migration. Interestingly, the secretion of several cytokines and chemokines stimulating cancer cell metastasis was reduced in CAF-like MRC5 cells treated with Ech A compared to untreated MRC5 cells. Moreover, while conditioned medium from MRC5 cells enhanced the migration of non-small cell lung cancer cells, conditioned medium from MRC5 cells treated with Ech A suppressed cancer cell migration. In conclusion, we suggest that Ech A might be a potent adjuvant that increases the efficacy of cancer treatments to mitigate lung cancer progression. Overall design: To characterize the regulatory effect of Ech A on gene expression, we performed mRNA transcriptome analysis in MRC5 cells treated with or without Ech A. Samples were collected at both the 24 h and 72 h time points under each experimental condition, and differences in gene expression were analyzed by comparing the values at 72 h with those at 24 h.