Studies on the mode of action of synthetic diindolylmethane derivatives against triple negative breast cancer cells.

Diindolylmethane (DIM) is a metabolic product of indole-3-carbinol (I3C), the major phytochemicals present in cruciferous vegetables, which can modulate multiple signalling pathways in cancer. The present study deals with the mechanism of action of two synthetic biaryl conjugates of DIM in triple negative breast cancer cells. Out of 12 DIM derivatives tested, two compounds, DIM-1 and DIM-4, exhibit cytotoxicity with GI50 values of 9.83 ± 0.2195 µM and 8.726 ± 0.5234 µM, respectively, in 2D culture. In 3D culture, DIM-1 and DIM-4 show GI50 values of 24.000 ± 0.7240 µM and 19.230 ± 0.3754 µM, respectively. The non-toxic nature of the compounds was also established by the toxicity studies using the zebrafish model system. The two compounds induced apoptosis and anoikis in the cancer cells, which was confirmed by morphological analysis, nuclear fragmentation, membrane integrity assay, caspase activity measurements and modulation of pro/anti-apoptotic proteins. The compounds inhibited cell migration and MMP-2 and MMP-9 activities indicating their anti-metastatic property. They also reduced the expression of active Ras, phosphorylated forms of PI3K, Akt and mTOR. Immunofluorescence studies revealed the reduced expression of EGFR and pEGFR in treated cells. To conclude, DIM-1 and DIM-4 induced anti-breast cancer effects by blocking EGF receptor and subsequently inhibiting Ras-mediated PI3K-Akt-mTOR signalling pathway.

Epoxyazadiradione induced apoptosis/anoikis in triple-negative breast cancer cells, MDA-MB-231, by modulating diverse cellular effects.

Triple-negative breast cancer (TNBC) is one of the most aggressive forms of its kind, which accounts for 15-20% of all breast cancers. As this cancer form lacks hormone receptors, targeted chemotherapy remains the best treatment option. Apoptosis and anoikis (detachment-induced cell death) induction by small molecules can prevent TNBC metastasis to a greater extent. Epoxyazadiradione (EAD) is a limonoid from the neem plant with an anticancer property. Here, we demonstrate that EAD induced mitochondria-mediated apoptosis and anoikis in TNBC cells (MDA-MB-231). Apart from this, it promotes antimigration, inhibition of colony formation, downregulation of MMP-9 and fibronectin, induction of G2/M phase arrest with downregulation of cyclin A2/cdk2, interference in cellular metabolism, and inhibition of nuclear factor kappa-B (NF-kB) nuclear translocation. Moreover, a significant reduction is observed in the expression of EGFR on the plasma membrane and nucleus upon treatment with EAD. Among the diverse cellular effects, anoikis induction, metabolic interference, and downregulation of membrane/nuclear EGFR expression by EAD are reported here for the first time. To summarize, EAD targets multiple cellular events to induce growth arrest in TNBC, and hence can be developed into the best antineoplastic agent in the future.

Exosomes and exosomal RNAs in breast cancer: A status update.

Improved treatment of breast cancer, the world's second most common cancer, requires identification of new sensitive prognostic and diagnostic biomarkers. Exosomes are lipid-bilayer extracellular vesicles of size 30-150 nm, released by all cell types, including breast cancer cells. Cellular communication is the primary function attributed to them. This review discusses the potential utility of exosomes and exosomal RNAs (microRNAs [miRNAs]/long non-coding RNAs [LncRNAs]) in breast cancer biology and treatment. The existing literature shows that exosomes play a significant role in breast tumorigenesis and progression through transfer miRNAs and LncRNAs. These miRNAs and LncRNAs function by post-transcriptionally regulating their target mRNAs, eventually leading to modulation of expression/repression. Over the past two decades, numerous publications point towards diagnostic and therapeutic applications of exosomal miRNAs/LncRNAs. Until now, we do not have clinically approved exosome-based therapeutics. Therefore, it is high time that clinicians and cancer researchers utilise exosome's benefits through randomised clinical trials for better management of breast cancer.