27-Hydroxycholesterol, The Estrogen Receptor Modulator, Alters DNA Methylation in Breast Cancer.

27-hydroxycholesterol (27-HC) is the first known endogenous selective estrogen receptor modulator (SERM), and its elevation from normal levels is closely associated with breast cancer. A plethora of evidence suggests that aberrant epigenetic signatures in breast cancer cells can result in differential responses to various chemotherapeutics and often leads to the development of resistant cancer cells. Such aberrant epigenetic changes are mostly dictated by the microenvironment. The local concentration of oxygen and metabolites in the microenvironment of breast cancer are known to influence the development of breast cancer. Hence, we hypothesized that 27-HC, an oxysterol, which has been shown to induce breast cancer progression via estrogen receptor alpha (ERα) and liver X receptor (LXR) and by modulating immune cells, may also induce epigenetic changes. For deciphering the same, we treated the estrogen receptor-positive cells with 27-HC and identified DNA hypermethylation on a subset of genes by performing DNA bisulfite sequencing. The genes that showed significant DNA hypermethylation were phosphatidylserine synthase 2 (PTDSS2), MIR613, indoleamine 2,3-dioxygenase 1 (IDO1), thyroid hormone receptor alpha (THRA), dystrotelin (DTYN), and mesoderm induction early response 1, family member 3 (MIER). Furthermore, we found that 27-HC weakens the DNMT3B association with the ERα in MCF-7 cells. This study reports that 27-HC induces aberrant DNA methylation changes on the promoters of a subset of genes through modulation of ERα and DNMT3B complexes to induce the local DNA methylation changes, which may dictate drug responses and breast cancer development.

Urolithins: The Colon Microbiota Metabolites as Endocrine Modulators: Prospects and Perspectives.

Selective estrogen receptor modulators (SERMs) have been used in hormone related disorders, and their role in clinical medicine is evolving. Tamoxifen and raloxifen are the most commonly used synthetic SERMs, and their long-term use are known to create side effects. Hence, efforts have been directed to identify molecules which could retain the beneficial effects of estrogen, at the same time produce minimal side effects. Urolithins, the products of colon microbiota from ellagitannin rich foodstuff, have immense health benefits and have been demonstrated to bind to estrogen receptors. This class of compounds holds promise as therapeutic and nutritional supplement in cardiovascular disorders, osteoporosis, muscle health, neurological disorders, and cancers of breast, endometrium, and prostate, or, in essence, most of the hormone/endocrine-dependent diseases. One of our findings from the past decade of research on SERMs and estrogen modulators, showed that pomegranate, one of the indirect but major sources of urolithins, can act as SERM. The prospect of urolithins to act as agonist, antagonist, or SERM will depend on its structure; the estrogen receptor conformational change, availability and abundance of co-activators/co-repressors in the target tissues, and also the presence of other estrogen receptor ligands. Given that, urolithins need to be carefully studied for its SERM activity considering the pleotropic action of estrogen receptors and its numerous roles in physiological systems. In this review, we unveil the possibility of urolithins as a potent SERM, which we are currently investigating, in the hormone dependent tissues.

Ficus extract-A promising agent for antimammary tumorigenesis: A review on current status and future possibilities.

Pharmacological studies have shown that various species of Ficus have antiviral, antidiarrheal, antipyretic, hypolipidemic, antidiabetic, antioxidant, anticancer, antiparasitic, antiangiogenic, anti-inflammatory, antibacterial, antiplatelet, reproductive, dermatological, immunological, endocrine, and hepato and nephron protective effects. But there is no sufficient research on biomolecules present in the leaf extract of Ficus religiosa and its mechanism of action. We have previously reported that bioavailable constituents of F. religiosa leaf extract exert photosensitizing and apoptosis-inducing capability through the generation of intracellular reactive oxygen species on breast cancer cells. In this review, we have evaluated the expression of checkpoint proteins of G1/S and sub G0 phase with wet lab data and also have done a data mining of other research for other potential mechanistic action of the F. religiosa leaf extract.

Pomegranate fruit as a rich source of biologically active compounds.

Pomegranate is a widely used plant having medicinal properties. In this review, we have mainly focused on the already published data from our laboratory pertaining to the effect of methanol extract of pericarp of pomegranate (PME) and have compared it with other relevant literatures on Punica. Earlier, we had shown its antiproliferative effect using human breast (MCF-7, MDA MB-231), and endometrial (HEC-1A), cervical (SiHa, HeLa), and ovarian (SKOV3) cancer cell lines, and normal breast fibroblasts (MCF-10A) at concentration of 20-320 µg/mL. The expressions of selected estrogen responsive genes (PR, pS2, and C-Myc) were downregulated by PME. Unlike estradiol, PME did not increase the uterine weight and proliferation in bilaterally ovariectomized Swiss-Albino mice models and its cardioprotective effects were comparable to that of 17 ß -estradiol. We had further assessed the protective role of PME on skeletal system, using MC3T3-E1 cells. The results indicated that PME (80 µg/mL) significantly increased ALP (Alkaline Phosphatase) activity, supporting its suggested role in modulating osteoblastic cell differentiation. The antiosteoporotic potential of PME was also evaluated in ovariectomized (OVX) rodent model. The results from our studies and from various other studies support the fact that pomegranate fruit is indeed a source of biologically active compounds.

Bax translocation mediated mitochondrial apoptosis and caspase dependent photosensitizing effect of Ficus religiosa on cancer cells.

The main aim of the present work was to investigate the potential effect of acetone extract of Ficus religosa leaf (FAE) in multiple apoptosis signalling in human breast cancer cells. FAE treatment significantly induced dose and time dependent, irreversible inhibition of breast cancer cell growth with moderate toxicity to normal breast epithelial cells. This observation was validated using Sulforhodamine B assay. Cell cycle analysis by Flow cytometry showed cell cycle arrest in G1 phase and induction of sub-G0 peak. FAE induced chromatin condensation and displayed an increase in apoptotic population in Annexin V-FITC/PI (Fluorescein isothiocyanate/Propidium iodide) double staining. FAE stimulated the loss of mitochondrial membrane potential in multiple breast cancer cell lines when compared to normal diploid cells. To understand the role of Bax in FAE induced apoptosis, we employed a sensitive cell based platform of MCF-7 cells expressing Bax-EGFP. Bax translocation to mitochondria was accompanied by the disruption of mitochondrial membrane potential and marked elevation in LEHDase activity (Caspase 9). Consistent with this data, FAE induced Caspase activation as evidenced by ratio change in FRET Caspase sensor expressing MCF-7 cell line and cleavage of prominent Caspases and PARP. Interestingly, FAE accelerated cell death in a mitochondrial dependent manner in continuous live cell imaging mode indicating its possible photosensitizing effect. Intracellular generation of reactive oxygen species (ROS) by FAE played a critical role in mediating apoptotic cell death and photosensitizing activity. FAE induced dose and time dependent inhibition of cancer cell growth which was associated with Bax translocation and mitochondria mediated apoptosis with the activation of Caspase 9 dependent Caspase cascade. FAE also possessed strong photosensitizing effect on cancer cell line that was mediated through rapid mitochondrial transmembrane potential loss and partial Caspase activation involving generation of intracellular ROS.