Mining the deep Red-Sea brine pool microbial community for anticancer therapeutics

Luke Esau,Ulrich Stingl,Vladimir B Bajic,Guishan Zhang,Mandeep Kaur,Sunil Sagar

doi:10.1186/s12906-019-2554-0

Abstract

BackgroundMicrobial species in the brine pools of the Red Sea and the brine pool-seawater interfaces are exposed to high temperature, high salinity, low oxygen levels and high concentrations of heavy metals. As adaptations to these harsh conditions require a large suite of secondary metabolites, these microbes have a huge potential as a source of novel anticancer molecules.MethodsA total of 60 ethyl-acetate extracts of newly isolated strains from extreme environments of the Red-Sea were isolated and tested against several human cancer cell lines for potential cytotoxic and apoptotic activities.ResultsIsolates from the Erba brine-pool accounted for 50% of active bacterial extracts capable of inducing 30% or greater inhibition of cell growth. Among the 60 extracts screened, seven showed selectivity towards triple negative BT20 cells compared to normal fibroblasts.ConclusionIn this study, we identified several extracts able to induce caspase-dependent apoptosis in various cancer cell lines. Further investigations and isolation of the active compounds of these Red Sea brine pool microbes may offer a chemotherapeutic potential for cancers with limited treatment options.

Highlights

Microbial species in the brine pools of the Red Sea and the brine pool-seawater interfaces are exposed to high temperature, high salinity, low oxygen levels and high concentrations of heavy metals
This study reports on anticancer activity of extracts from bacterial isolates from different habitats around brine pools within the Red Sea
Taxonomic classification of microbes isolated from the Red Sea Most bacteria isolated from the four brine pools Erba, Discovery, Kebrit, and Nereus were closely related to known and well described halophilic species within Proteobacteria and Archaea (Table 1)

Summary

Introduction

Microbial species in the brine pools of the Red Sea and the brine pool-seawater interfaces are exposed to high temperature, high salinity, low oxygen levels and high concentrations of heavy metals. The hallmarks of cancer, which categorises the survival and proliferative mechanisms of cancer cells, was first described by Hanahan and Weinberg [1]. A review by Agrawal et al [9] described nonribosomal peptides isolated from marine microbes having anticancer activity while in a research article Neelam et al [10] discovered a marine halo-alkaliphilic bacteria species possessing anti breast cancer activity.

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