Chebulinic acid inhibits MDA‐MB‐231 breast cancer metastasis and promotes cell death through down regulation of SOD1 and induction of autophagy

Chebulinic Acid: An Incipient Anticancer Agent

BACKGROUND

Terminalia chebula (T. chebula) comprising chebulinic acid as its principle active constituent is used to cure various diseases. T. chebula and chebulinic acid are used as antimicrobial, antioxidant, antidiabetic, anti-inflammatory, hepatoprotective, antimutagenic, radioprotective, cardioprotective, antiproliferative, antiarthritic, anticaries, and so on.

OBJECTIVE

The objective of this current study is to give an overview of the recent literature and patents of T. chebula and chebulinic acid including methods of its isolation/extraction and their application in the prevention of various cancers and other diseases.

METHODS

Present research and patents highlighting the anti-cancer potential of T. chebula and chebulinic acid have been studied and discussed keeping in view the scientific novelty and impact.

RESULTS

Both T. chebula and chebulinic acid are currently being explored for their anticancer potential in vitro and in vivo. They are either incorporated alone or in combination with other plants or drugs to show their activity and many clinical trials are also going on various potentials of the plant and chebulinic acid. Novel extraction techniques are also explored and patented. Efforts are being made to improve the bioavailability by developing Novel herbal drug delivery systems of the plant extract or chebulinic acid itself.

CONCLUSION

Anti-cancer potential of T. chebula and chebulinic acid may be well established by promising clinical trials and may open new interventions in various tumors. Clinical trials in conjunction with standard therapies are required to explore and validate the actual potential of T. chebula and chebulinic acid respectively.

Identification of novel inhibitors against Med15a KIX domain of Candida glabrata

Candida glabrata, the second most common cause of invasive fungal infections, exhibits multi-drug resistance to commonly used antifungal drugs. To counter this resistance, there is a critical need for novel antifungals. This study identifies small molecule inhibitors that target a three-helix bundle KIX domain in the Med15a Mediator subunit of Candida glabrata (CgMed15a KIX). This domain plays a crucial role by interacting with the Pleiotropic Drug Resistance transcription factor Pdr1, a key regulator of the multidrug resistance pathway in Candida glabrata. We performed high throughput computational screening of large chemical datasets against the binding sites of the CgMed15a KIX domain to identify novel inhibitors. We selected six potential candidates with high affinity and confirmed their binding with the CgMed15a KIX domain. A phytochemical compound, Chebulinic acid binds to the CgMed15a KIX domain with a KD value of 0.339 μM and shows significant inhibitory effects on the growth of Candida glabrata. Molecular dynamics simulation studies further revealed the structural stability of the CgMed15a KIX-Chebulinic acid complex. Thus, in conclusion, this study highlights Chebulinic acid as a novel potential antifungal compound against Candida glabrata.

CYP2E1 triggered GRP78/ATF6/CHOP signaling axis inhibit apoptosis and promotes progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Cytochrome P450 2E1 (CYP2E1) is an enzyme, primarily involved in the metabolism of xenobiotics and procarcinogens. The present study was designed to investigate the potential role of CYP2E1 triggered endoplasmic reticulum stress in the progression of HCC through inhibition of apoptosis. In vitro CYP2E1 promotes HepG2 cell migration, reduced chromatin condensation, enhanced intracellular ROS accumulation and induce cell cycle progression. Conversely this effect was averted by CYP2E1 siRNA, selective inhibitor Diallyl sulphide (DAS) and antioxidants (vitamin C and E). In vivo Diethylnitrosamine (DEN) induced HCC rats showed decreased body weight and increased relative liver weight. Moreover, macro trabecular-massive HCC (MTM-HCC) histological subtyping showed pathological features like well-differentiated tumors, micro-trabecular and pseudo glandular patterns, megakaryocytes and cholestasis. Masson's trichrome staining revealed an intensive accumulation of collagen fibers in the extracellular matrix (ECM). Increased CYP2E1, VEGF and PCNA enhance the carcinogenicity as revealed in immunohistochemistry results. Immunoblot analysis showed reduced expression of copper-zinc superoxide dismutase (CuZnSOD) and manganese superoxide dismutase (MnSOD) in cytosolic as well as mitochondrial fraction of rat liver tissue respectively. Also, increased level of CYP2E1 stimulated the upregulation of unfolded proteins response (UPR) and ER stress-related proteins such as Glucose regulatory protein 78 (GRP78), activating transcription factor 6 (ATF6) and CCAAT enhancer-binding protein (C/EBP) homologous protein (CHOP). Meanwhile, CYP2E1 stimulated ER-stress reduces BCL2 and downregulates the cleaved caspase 3 thus suppresses apoptosis. in. Furthermore, immunofluorescence revealed increased expression level of α-SMA in the HCC rat liver tissue. The level of CYP2E1 mRNA was significantly increased. Altogether, these findings indicate that CYP2E1 has a dynamic role in the pathogenesis of HCC and might be a budding agent in liver carcinogenesis therapy.

Towards dual function of autophagy in breast cancer: A potent regulator of tumor progression and therapy response

As a devastating disease, breast cancer has been responsible for decrease in life expectancy of females and its morbidity and mortality are high. Breast cancer is the most common tumor in females and its treatment has been based on employment of surgical resection, chemotherapy and radiotherapy. The changes in biological behavior of breast tumor relies on genomic and epigenetic mutations and depletions as well as dysregulation of molecular mechanisms that autophagy is among them. Autophagy function can be oncogenic in increasing tumorigenesis, and when it has pro-death function, it causes reduction in viability of tumor cells. The carcinogenic function of autophagy in breast tumor is an impediment towards effective therapy of patients, as it can cause drug resistance and radio-resistance. The important hallmarks of breast tumor such as glucose metabolism, proliferation, apoptosis and metastasis can be regulated by autophagy. Oncogenic autophagy can inhibit apoptosis, while it promotes stemness of breast tumor. Moreover, autophagy demonstrates interaction with tumor microenvironment components such as macrophages and its level can be regulated by anti-tumor compounds in breast tumor therapy. The reasons of considering autophagy in breast cancer therapy is its pleiotropic function, dual role (pro-survival and pro-death) and crosstalk with important molecular mechanisms such as apoptosis. Moreover, current review provides a pre-clinical and clinical evaluation of autophagy in breast tumor.

Effects and Mechanisms of Action of Preussin, a Marine Fungal Metabolite, against the Triple-Negative Breast Cancer Cell Line, MDA-MB-231, in 2D and 3D Cultures

Triple-negative breast cancer (TNBC) represents an aggressive subtype of breast cancer (BC) with a typically poorer prognosis than other subtypes of BC and limited therapeutic options. Therefore, new drugs would be particularly welcome to help treat TNBC. Preussin, isolated from the marine sponge-associated fungus, Aspergillus candidus, has shown the potential to reduce cell viability and proliferation as well as to induce cell death and cell cycle arrest in 2D cell culture models. However, studies that better mimic the tumors in vivo, such as 3D cell cultures, are needed. Here, we studied the effects of preussin in the MDA-MB-231 cell line, comparing 2D and 3D cell cultures, using ultrastructural analysis and the MTT, BrdU, annexin V-PI, comet (alkaline and FPG modified versions), and wound healing assays. Preussin was found to decrease cell viability, both in 2D and 3D cell cultures, in a dose-dependent manner, impair cell proliferation, and induce cell death, therefore excluding the hypothesis of genotoxic properties. The cellular impacts were reflected by ultrastructural alterations in both cell culture models. Preussin also significantly inhibited the migration of MDA-MB-231 cells. The new data expanded the knowledge on preussin actions while supporting other studies, highlighting its potential as a molecule or scaffold for the development of new anticancer drugs against TNBC.

LCS-1 inhibition of superoxide dismutase 1 induces ROS-dependent death of glioma cells and degradates PARP and BRCA1

Gliomas are characterized by high morbidity and mortality, and have only slightly increased survival with recent considerable improvements for treatment. An innovative therapeutic strategy had been developed via inducing ROS-dependent cell death by targeting antioxidant proteins. In this study, we found that glioma tissues expressed high levels of superoxide dismutase 1 (SOD1). The expression of SOD1 was upregulated in glioma grade III and V tissues compared with that in normal brain tissues or glioma grade I tissues. U251 and U87 glioma cells expressed high levels of SOD1, low levels of SOD2 and very low levels of SOD3. LCS-1, an inhibitor of SOD1, increased the expression SOD1 at both mRNA and protein levels slightly but significantly. As expected, LCS-1 caused ROS production in a dose- and time-dependent manner. SOD1 inhibition also induced the gene expression of HO-1, GCLC, GCLM and NQO1 which are targeting genes of nuclear factor erythroid 2-related factor 2, suggesting the activation of ROS signal pathway. Importantly, LCS-1 induced death of U251 and U87 cells dose- and time-dependently. The cell death was reversed by the pretreatment of cells with ROS scavenges NAC or GSH. Furthermore, LCS-1 decreased the growth of xenograft tumors formed by U87 glioma cells in nude mice. Mechanistically, the inhibition of P53, caspases did not reverse LCS-1-induced cell death, indicating the failure of these molecules involving in cell death. Moreover, we found that LCS-1 treatment induced the degradation of both PARP and BRCA1 simultaneously, suggesting that LCS-1-induced cell death may be associated with the failure of DNA damage repair. Taking together, these results suggest that the degradation of both PARP and BRCA1 may contribute to cell death induced by SOD1 inhibition, and SOD1 may be a target for glioma therapy.

SOX4-mediated FBW7 transcriptional upregulation confers Tamoxifen resistance in ER+ breast cancers via GATA3 downregulation

AIM

Tamoxifen-mediated endocrine therapy has been standard treatment for ER+ breast cancers; however, majority of them acquire resistance leading to disease relapse. Although numerous substrates of E3 ligase FBW7 are known, only a handful of factors that regulate FBW7 expression and function are reported. In particular, there remains a lack of in-depth understanding of FBW7 transcriptional regulation.

MATERIALS AND METHODS

Luciferase reporter assay was performed after cloning full length and truncated FBW7 promoters followed by Chromatin immunoprecipitation assay to validate binding of SOX4 on FBW7 promoter. Transcriptional regulation of FBW7 by SOX4 and their biological consequences with respect to ER+ breast cancer was then evaluated using immunoblotting and other cell based assays.

KEY FINDINGS

SOX4 positively regulates FBW7 at transcriptional level by binding to three putative SOX4 biding sites within 3.1 kb long FBW7 promoter. Analysis of publicly available RNAseq datasets also showed a positive correlation between SOX4 and FBW7 mRNA in cancer cell lines and patient samples. qPCR and Immunoblotting confirmed that transiently or stably expressed SOX4 induced both endogenous FBW7 mRNA and protein levels. Our findings further demonstrated that increased levels of SOX4 and FBW7 in MCF7 mammospheres promoted cancer stemness and tumor cell dormancy. We further showed that both MCF7 mammospheres and MCF^TAMR cells had elevated SOX4 levels which apparently enhanced FBW7 to potentiate GATA3 degradation leading to enhanced stemness, tumor dormancy and Tamoxifen resistance in MCF7^TAMR as well as patients with ER+ breast cancers.

SIGNIFICANCE

Targeting SOX4-FBW7-GATA3 axis may overcome tamoxifen resistance in ER+ breast cancers.

Modifications to the Transwell Migration/Invasion Assay Method That Eases Assay Performance and Improves the Accuracy

Migration is a key property of live cells and critical for normal development, immune response, and disease processes such as cancer metastasis and inflammation. Methods to examine cell migration are especially useful and important for a wide range of biomedical research such as cancer biology, immunology, vascular biology, cell biology, and developmental biology. In vitro assays are excellent approaches to extrapolate to in vivo situations and study live cells behavior. The aim of this article is to discuss the existing methods for transwell migration/invasion studies, the problems associated with this assay, and proposed modifications to this methodological approach that makes it simple to perform and improve the assay accuracy. Results of our studies demonstrated that the count of cells that had grown on top of the membrane is important to accurately evaluate the percentage of migrated/invaded cells. The results also showed that the transparent transwell insert with 4',6-diamidino-2-phenylindole (DAPI) stained cells is the best approach to ease the analysis of cell numbers on top of the membranes. In addition, the overlay of bright light (representing membrane pores) and DAPI images can further improve the accuracy of cell count. All these modifications in combination simplify the assay performance and improve the accuracy of the transwell migration assay method.

Learning from Yeast about Mitochondrial Carriers

Mitochondria are organelles that play an important role in both energetic and synthetic metabolism of eukaryotic cells. The flow of metabolites between the cytosol and mitochondrial matrix is controlled by a set of highly selective carrier proteins localised in the inner mitochondrial membrane. As defects in the transport of these molecules may affect cell metabolism, mutations in genes encoding for mitochondrial carriers are involved in numerous human diseases. Yeast Saccharomyces cerevisiae is a traditional model organism with unprecedented impact on our understanding of many fundamental processes in eukaryotic cells. As such, the yeast is also exceptionally well suited for investigation of mitochondrial carriers. This article reviews the advantages of using yeast to study mitochondrial carriers with the focus on addressing the involvement of these carriers in human diseases.

Nanoparticle Production of Terminalia Chebula Extracts by Expansion of Supercritical Solution (ESS)

Terminalia chebula pharmaceuticals were extracted by using the supercritical fluid extraction (SFE) technique. Under the optimal conditions of 184 [Formula: see text]L modifier volume, 46 min dynamic extraction time, and 316 atm fluid pressure, the extraction procedure was optimized by central composite design. A modified rapid expansion of supercritical solution (RESS) technique, named expansion of the supercritical solution (ESS) was used to create the extracted pharmaceutical nanoparticles (NPs). In ESS, supercritical carbon dioxide (SC-CO[Formula: see text] was saturated with the extracts at high-pressure. Next, a pressure drop reduced the SC-CO2 solubility power in a way the extracts started to precipitate. In contrast to RESS, the pressure was permanently conserved above the critical pressure before and after depressurization. Therefore, the expansion process was gentle, which led to obtaining small and uniform particles. In the NP production process, the most adequate parameters were 360[Formula: see text]atm premier pressure, 120[Formula: see text]atm subsequent pressure, 25[Formula: see text]min equilibrium time, 30[Formula: see text]min sedimentation time, and [Formula: see text]C temperature. The average size of precipitated NPs was 41[Formula: see text]nm according to the results of field emission scanning electron microscopy analysis. The liquid chromatography-mass spectrometry evaluation demonstrated the presence of chebulinic and chebulagic acids in the extracted sample.

Calcium activity in response to nAChR ligands in murine bone marrow granulocytes with different Gr-1 expression

Polymorphonuclear neutrophilic granulocytes (PMNs) are the largest proportion of leukocytes in adult human blood that perform numerous functions, including phagocytosis, degranulation, generation of reactive oxygen species, and NETosis. Excessive neutrophil activity associates with hyperinflammation and tissue damage during pathologies such as inflammatory bowel disease, diabetes mellitus, tuberculosis, and coronavirus disease 2019. Nicotinic acetylcholine receptors (nAChRs) can modulate immune cells, including neutrophils, functions, therefore, nAChR ligands are considered as the potent agents for therapy of inflammation. Earlier it was shown, that about 30% of PMNs from the acute inflammatory site responded to nicotine by calcium spikes. In this study, we studied the generation of calcium spikes in murine granulocytes with different maturity level (evaluated by Gr-1 expression) isolated from bone marrow in response to ligands of nAChRs in control and under chronic nicotine consumption. It was found that nearly 20%-25% cells in the granulocyte population responded to nicotine or selective antagonists of different type of nAChRs (α-cobratoxin, GIC, and Vc1.1). We demonstrated that in the control group Ca2+ -mobilizing activity was regulated through α7 and α9α10 nAChRs in immature granulocytes (Gr-1int ), whereas in mature granulocytes (Gr-1hi ) it was regulated through α7, α3β2, and α9-contained nAChRs. Sensitivity of PMNs to nicotine depended on their maturity level after chronic nicotine consumption. Gr-1int cells responded to nicotine through α7 and α9-contained nAChRs, while Gr-1hi did not respond to nicotine. Thus, calcium response to nAChR ligands in bone marrow PMNs depends on their maturity level.

Exploring scientific validation of Triphala Rasayana in ayurveda as a source of rejuvenation for contemporary healthcare: An update

ETHNOPHARMACOLOGICAL RELEVANCE

Ayurveda remains the classical and comprehensive part of the ancient Indian medicine system for well-being promotive, disease preventive, and revival approach for the human body. Triphala Rasayana is mentioned in Ayurveda, comprising fruits of three plant species viz. Phyllanthus emblica L. (P. emblica), Terminalia chebula Retz (T. chebula), and Terminalia bellirica Roxb (T.bellirica). Triphala Rasayana has been utilized in various traditional medicine systems, viz., Ayurveda, Siddha, and Unani. Traditionally Rasayana based drugs are utilized in different kinds of diseases without pathophysiological associations as indicated by current medication. Various medicinal attributes of Triphala Rasayana include antioxidant, anticancer, antidiabetic, antimicrobial, immunomodulatory, and anticataract and is also considered as a pillar for gastrointestinal treatment, specifically in functional gastrointestinal disorders (FGIDs). Due to Rasayana's accessible mode of administration, availability, and affordability, there is an increase in its global acceptance.

AIM OF REVIEW

This review article summarizes the scientific validation, traditional uses, bioactive compounds, and ethnopharmacological properties of Triphala Rasayana. It also documents recent data on in vivo and in vitro pharmacological studies and clinical effects of Triphala Rasayana.

MATERIAL AND METHOD

A literature review is carried out using PubMed, ScienceDirect, Scopus, web of science, Ayush Research Portal, and Clinical Trials Registry-India. In addition to an electronic search, traditional ayurvedic texts and books were used as sources of information.

RESULTS

Traditionally, "Triphala Rasayana" is classified as a tridoshic rasayana and one of the most well-studied ayurvedic Rasayana. It showed various pharmacological activities such as anticancer, antioxidant, antibacterial, immunomodulatory, cardioprotective, and antidiabetic. Besides this, Rasayana has reported ethnopharmacological activities such as antimicrobial, anticataract, wound healing, and radioprotection. It has shown a good impact on the gastrointestinal tract (GIT) system with the reported pharmacological activities in gastrointestinal disorders such as constipation, gastric ulcer, and inflammatory bowel disease (IBD). Phytochemical studies of Triphala Rasayana revealed chemical constituents like gallic acid, ellagic acid, chebulic acid, chebulinic acid, methyl gallate, emblicanin A, and emblicanin B. Additionally, clinical studies found Triphala Rasayana to be effective against diabetes, constipation, and obesity.

CONCLUSION

The present review revealed that Triphala Rasayana may treat a diverse range of diseases, especially GIT disorders. Considering the beneficial properties of Triphala Rasayana and it's proven non-toxic nature could be a source of rejuvenation in contemporary healthcare. Nevertheless, its clinical data effectively provided precious signals to correlate ayurvedic biology and modern medicine.

Autophagy signals orchestrate chemoresistance of gynecological cancers

Gynecological cancers are characterized by a high mortality rate when chemoresistance develops. Autophagy collaborates with apoptosis and participates in homeostasis of chemoresistance. Recent findings supported that crosstalk of necrotic, apoptotic and autophagic factors, and chemotherapy-driven hypoxia, oxidative stress and ER stress play critical roles in chemoresistance in gynecological cancers. Meanwhile, current studies have shown that autophagy could be regulated by and cooperate with metabolic regulator, survival factors, stemness factors and specific post-translation modification in chemoresistant tumor cells. Meanwhile, non-coding RNA and autophagy crosstalk also contribute to the chemoresistance. Until now, analysis of individual autophagy factors towards the clinical significance and chemoresistance in gynecological cancer is still lacking. We suggest comprehensive integrated analysis of cellular homeostasis and tumor microenvironment to clarify the role of autophagy and the associated factors in cancer progression and chemoresistance. Panel screening of pan-autophagic factors will pioneer the development of risk models for predicting efficacy of chemotherapy and guidelines for systematic treatment and precision medicine.

Forkhead-box A3 (FOXA3) represses cancer stemness and partially potentiates chemosensitivity by targeting metastasis-associated in colon cancer 1 (MACC1) signaling pathway in colorectal cancer cells

BACKGROUND

The major challenge to the treatment of advanced colorectal cancer (CRC) is persistent occurrence of chemoresistance. One of the established etiologies is the existence of cancerstem-like cells (CSCs) using which tumors resist to external therapeutic challenges.

OBJECTIVE

The forkhead-box A3 (FOXA3) is a potent transcription factor that potentiates the acquisition and maintenance of stemness fate in many physiological systems. However, its effect on cancer stemness, particularly treatment, has not been explored in CRC, forming the basis of the current study.

METHODS

FOXA3 expression in oxaliplatin-resistant CRC tissues and cells was evaluated using RT-qPCR. Effects of FOXA3 manipulation on sensitivity to oxaliplatin were assessed using WST-1, apoptotic ELISA, colony formation and xenograft model. Effects of FOXA3 alteration on CSCs were determined using tumor sphere assay and CD44 staining. Transcriptional regulation of MACC1 by FOXA3 was studied using ChIP, Co-IP and luciferase reporter assay.

RESULTS

FOXA3 expression was significantly reduced in tumor samples from oxaliplatin-non-responsive patients compared with that in tumor samples from oxaliplatin-sensitive patients. This downregulation of FOXA3 expression predicted a poor post-chemotherapy overall- or disease-free survival in our 117-patient cohort. FOXA3 down-regulation significantly enhanced cell survival and stem-like properties, thus rendering the CRC cells unresponsiveness to oxaliplatin-induced cell death. Mechanistically, the anti-neoplasic effect of FOXA3 was mediated mainly through transcriptional repression of metastasis-associated in colon cancer 1 (MACC1) in oxaliplatin-resistant CRC cells.

CONCLUSION

Our findings establish FOXA3 as a potent tumor suppressor in CRC, which may disrupt the maintenance of stemness and modulate sensitivity to oxaliplatin by inhibiting the transcription of MACC1 within CRC cells.