Carotenoid pigment of Halophilic archaeon Haloarcula sp. A15 induces apoptosis of breast cancer cells

Abstract

The halophilic microorganisms living in extreme environments contain high concentrations of carotenoids with notable medical abilities. The purpose of this study was to evaluate the anticancer effect of carotenoids extracted from native Iranian halophilic microorganisms with the ability to inhibit breast cancer cell line. To begin the study, 40 halophilic strains were cultured, and 8 strains capable of producing pigmented colonies were chosen from those cultured strains. In the next step, from among 8 strains using MTT assay, 1 capable of reducing cell viability of the breast cancer MCF-7 cell line was chosen as a selective strain. The principal carotenoid was characterized using UV-visible, FT-IR spectroscopic, and LC-MASS analyses. Using real time PCR technique, the expression of genes specific for apoptosis, in the presence or absence of carotenoid, was examined. Among all strains, carotenoid extracted from strain A15 had the most potent cytotoxic effect on breast cancer cell line (IC 50 = 0.0645 mg/mL). 16S rRNA gene analysis showed that strain A15 had similarity with Haloarcula hispanica for about 99.5%. According to the analysis results, it could be estimated that the principal carotenoid extracted form Haloarcula sp. A15 was similar to bacterioruberin. Both early and late apoptosis were increased significantly about 10% and 39%, respectively, due to upregulation of CASP3, CASP8, BAX genes expression in MCF-7 cell line. In contrast, the expression of genes MKI67, SOX2 were significantly downregulated in treated MCF-7 cell line. The results of this study showed that Halophilic archaeon strain could be a good candidate for the production of high added-value bacterioruberin due to its possible anticancer properties.

Extracts from Microalgae and Archaea from the Andalusian Coast: A Potential Source of Antiproliferative, Antioxidant, and Preventive Compounds

“…The most interesting results, however, were obtained by the HP from Halobacterium salinarum (IC 50 value 110.56 ± 17.12 and 111.20 ± 22.20 µg/mL in HCT-15 and T84 cells, respectively). This is in agreement with previous results for both archaea species [38,39]. Since the best antitumor effects were observed in Chlorella sorokiniana, Haloarcula hispanica, and Halobacterium salinarum, these extracts were selected to examine their possible effect on inhibiting the migratory capacity of T84 and HCT-15 tumor cells.…”

Bacterioruberin: Biosynthesis, Antioxidant Activity, and Therapeutic Applications in Cancer and Immune Pathologies

“…The results of this study showed that the carotenoid extract isolated from Haloarcula sp. A15 could be a good candidate for the production of high-added-value bacterioruberin due to its possible anticancer properties [75]. The antiproliferative effect on breast cancer cell lines has been explored in other studies [15,75].…”

“…A15 could be a good candidate for the production of high-added-value bacterioruberin due to its possible anticancer properties [75]. The antiproliferative effect on breast cancer cell lines has been explored in other studies [15,75]. In particular, Haloferax mediterranei carotenoid extracts reduced cell adhesion, viability, diameter, and cell concentrations in cell lines representative of the four well-defined subtypes of breast cancer (Luminal A, Luminal B, HER2-enriched, and triple-negative) [15].…”