# 2-Amino-3-Chlorobenzoic Acid from Streptomyces coelicolor: A Cancer Antagonist Targeting PI3K/AKT Markers via miRNA Modulation

## TL;DR

This study identifies 2-amino-3-chlorobenzoic acid from Streptomyces coelicolor as a promising anticancer compound that targets breast cancer cells and induces apoptosis.

## Contribution

The discovery of 2A3CB as a novel cancer antagonist targeting PI3K/AKT pathways via miRNA modulation in breast cancer cells.

## Key findings

- 2A3CB showed strong cytotoxicity against MDA-MB-231 breast cancer cells with low IC50 values.
- The compound inhibited cell proliferation, migration, and induced apoptosis via caspase pathways.
- It downregulated key markers like PTEN, PCNA, BAX, and STAT3, suggesting anti-metastatic potential.

## Abstract

Background/Objectives: Actinomycetes, particularly species within the Streptomyces genus, are renowned for their ability to produce a wide array of bioactive molecules with therapeutic potential. This study aimed to comprehensively investigate the antimicrobial and anticancer properties of Streptomyces coelicolor ERI-15, with a particular focus on a purified compound, 2-amino-3-chlorobenzoic acid (2A3CB), and its efficacy against microbial pathogens and breast cancer cell lines. Methods: Antimicrobial compounds were produced through fermentation techniques and isolated via column chromatography. Bioassay-guided fractionation was conducted against Staphylococcus aureus (ATCC 25923), methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (ATCC 25922), and Bacillus subtilis (ATCC 441). Major fractions were further purified using preparative thin-layer chromatography (TLC). The structures of active compounds were elucidated using spectral analyses including IR, mass spectrometry, and 1H/13C NMR. The compound 2A3CB (m/z 171) was tested against MDA-MB-231 and 3T3 cell lines. Cytotoxicity was assessed by the MTT assay, and apoptotic mechanisms were explored via cell proliferation assays, dual fluorescent staining, migration and invasion assays, and analysis of apoptotic markers at mRNA and protein levels. Results: 2A3CB exhibited strong cytotoxic effects on MDA-MB-231 cells, with IC50 values of 26 µM, 5 µM, and 7.2 µM at 24, 48, and 72 h, respectively. It significantly inhibited cell proliferation and migration, and induced apoptosis via caspase-mediated pathways. Expression levels of PTEN, PCNA, BAX, and STAT3 were downregulated, suggesting inhibition of metastasis through the suppression of invasion and migration. Conclusions: The results demonstrate that 2A3CB, derived from S. coelicolor ERI-15, possesses potent antimicrobial and anticancer properties. Its ability to inhibit growth and induce apoptosis in MDA-MB-231 breast cancer cells highlights its potential as a natural therapeutic candidate for targeted cancer treatment, particularly in breast cancer progression.