Suppression of mTOR Expression by siRNA Leads to Cell Cycle Arrest and Apoptosis Induction in MDA-MB-231 Breast Cancer Cells.

BACKGROUND: Mammary carcinogenesis, being ranked second in cancer-related mortality and the inadequacy of existing chemotherapy advocates the development of a novel treatment approach targeting its molecular signalling. Hyperactivation of mammalian target of rapamycin (mTOR) has a critical role in developing invasive mammary cancer and it can be a potential target. OBJECTIVE: This experiment was to explore the efficacy of mTOR-specific siRNA on therapeutic targeting of the mTOR gene, assess its proficiency in suppressing in vitro breast cancer and determine underlying molecular mechanisms. METHODS: Specific siRNA targeting mTOR was transfected into MDA-MB-231 cells and mTOR downregulation was validated through qRT-PCR and western blot analysis. Cell proliferation was analysed by MTT assay and confocal microscopy. Apoptosis was studied through flow cytometry and S6K, GSK-3ß and caspase 3 expression were estimated. Further, the effect of mTOR blockade on cell cycle progression was determined. RESULTS: Following transfection of mTOR-siRNA into the MDA-MB-231 cells, cell viability and apoptosis were examined which indicates that clinically relevant concentration of mTOR-siRNA inhibited cell growth and proliferation and promote apoptosis, resulting from the suppression of mTOR. This leads to the downregulation of mTOR downstream S6K and upregulation of GSK-3ß. An increased level of caspase 3 symbolises that the apoptotic activity is mediated through caspasedependent pathway. Further, mTOR downregulation causes cell cycle arrest in G0/G1 phase as observed in the flow cytometry study. CONCLUSION: With these results, we can conclude that mTOR-siRNA exerts direct 'anti-breast cancer' activity propagated by the S6K-GSK-3ß- caspase 3 mediated apoptosis and by inducing cell cycle arrest.

Molecular Insights into the Crosstalk Between Immune Inflammation Nexus and SARS-CoV-2 Virus.

COVID-19, a type of viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 has challenged the world as global pandemic. It has marked the identification of third generation of extremely pathogenic zoonotic coronaviruses of twenty-first century posing threat to humans and mainly targeting the lower respiratory tract. In this review, we focused on not only the structure and virology of SARS-COV-2 but have discussed in detail the molecular immunopathogenesis of this novel virus highlighting its interaction with immune system and the role of compromised or dysregulated immune response towards disease severity. We attempted to correlate the crosstalk between unregulated inflammatory outcomes with disrupted host immunity which may play a potential role towards fatal acute respiratory distress syndrome that claims to be life-threatening in COVID-19. Exploration and investigation of molecular host-virus interactions will provide a better understanding on the mechanism of fatal COVID-19 infection and also enlighten the escape routes from the same.

Molecular epigenetic dynamics in breast carcinogenesis.

Breast cancer has become one of the most common dreadful diseases that target women across the globe. The most obvious reasons we associate with it are either genetic mutations or dysregulation of pathways. However, there is yet another domain that has a significant role in influencing the genetic mutations and pathways. Epigenetic mechanisms influence these pathways either independently or in association with genetic mutations, thereby expediting the process of breast carcinogenesis. Breast cancer is governed by various transduction pathways such as PI3K/AKT/mTOR, NOTCH, ß Catenin, NF-kB, Hedgehog, etc. There are many proteins as well that serve to be tumor suppressors but somehow lose their ability to function. This may be because of either genetic mutation or a process that represses their function. Apart from these, there are a lot of individual factors like puberty, breastfeeding, abortion, parity, circadian rhythm, alcohol consumption, pollutants, and obesity that drive these mutations and hence alter the pathways. Epigenetic mechanisms like DNA methylation, histone modifications, and lncRNAs directly or indirectly bring alterations in the proteins that are involved in the pathways. They do this by either promoting the transcription of genes or by repressing it at the ground genetic level that advances breast carcinogenesis. Epigenetics precedes genetic mutation in driving carcinogenesis and so, it needs to be explored further to diversify the possibilities of target specific treatments. In this review, the general role of DNA methylation, histone modification, and lncRNAs in breast cancer and their role in influencing the oncogenic signaling pathways along with the various factors governing them have been discussed for a better understanding of the role of epigenetics in breast carcinogenesis.

LC-MS characterized methanolic extract of zanthoxylum armatum possess anti-breast cancer activity through Nrf2-Keap1 pathway: An in-silico, in-vitro and in-vivo evaluation.

ETHNOPHARMACOLOGICAL RELEVANCE: Zanthoxylum armatum DC (Rutaceae) containing flavonoids, alkaloids, coumarins, lignans, amides and terpenoid is well-known for its curative properties against various ailments including cancer. In the current research, phytochemicals present in the methanolic extract of Zanthoxylum armatum bark (MeZb) were characterized by LC-MS/MS analysis and chemotherapeutic potential of this extract was determined on DMBA-induced female Sprague Dawley rats. MATERIALS AND METHODS: A simple and fast high-performance liquid chromatography-mass spectroscopy (LC-MS/MS) of MeZb was established followed by in-vitro antioxidant assays. This was followed by in-silico docking analysis as well as cytotoxicity assessment. Successively in-vivo study of MeZb was performed in DMBA-induced Sprague Dawley rats possessing breast cancer along with detailed molecular biology studies involving immunofluorescence, RT-qPCR and Western blot analysis. RESULTS: LC-MS/MS investigation revealed the presence of compounds belonging to flavonoid, alkaloid and glycoside groups. MeZb revealed potential antioxidant activity in in-vitro antioxidant assays and strong binding energy of identified compounds was seen from the in-silico study with both HO1 and Keap1 receptor. Furthermore, the antioxidant action of MeZb was proven from the in-vivo analysis of antioxidant marker enzymes (lipid peroxidation, enzymic and non-enzymic antioxidants). This study also revealed upregulation of protective Nrf-2 following downregulation of Keap1 after MeZb treatment with respect to untreated cancerous rats. CONCLUSION: These results exhibited anti-breast-cancer potential of MeZb through Nrf2-Keap1 pathway which may be due to the flavonoids, alkaloids and glycosides present in it.

Strategic Developments & Future Perspective on Gene Therapy for Breast Cancer: Role of mTOR and Brk/ PTK6 as Molecular Targets.

Breast cancer is a serious health issue and a major concern in biomedical research. Alteration in major signaling (viz. PI3K-AKT-mTOR, Ras-Raf-MEK-Erk, NF-kB, cyclin D1, JAK-STAT, Wnt, Notch, Hedgehog signaling and apoptotic pathway) contributes to the development of major subtypes of mammary carcinoma such as HER2 positive, TNBC, luminal A and B and normal-like breast cancer. Further, mutation and expression parameters of different genes involved in the growth and development of cells play an important role in the progress of different types of carcinoma, making gene therapy an emerging new therapeutic approach for the management of life-threatening diseases like cancer. The genetic targets (oncogenes and tumor suppressor genes) play a major role in the formation of a tumor. Brk/PTK6 and mTOR are two central molecules that are involved in the regulation of numerous signaling related to cell growth, proliferation, angiogenesis, survival, invasion, metastasis, apoptosis, and autophagy. Since these two proteins are highly upregulated in mammary carcinogenesis, this can be used as targeted genes for the treatment of breast cancer. However, not much work has been done on them. This review highlights the therapeutic significance of Brk and mTOR and their associated signaling in mammary carcinogenesis, which may provide a strategy to develop gene therapy for breast cancer management.

Quercetin loaded folate targeted plasmonic silver nanoparticles for light activated chemo-photothermal therapy of DMBA induced breast cancer in Sprague Dawley rats.

Currently, the paucity of free drugs in conventional chemotherapy for breast-cancer curbs the desired therapeutic efficiency, often aggravating systemic toxicity. Quercetin (QRC) is a potential chemotherapeutic bio-flavonoid that is associated with poor hydrophilicity. In contrast to spherical silver nanoparticles (AgNPs), anisotropic AgNPs exhibit prominent plasmonic tunability in the near infrared (NIR) region allowing deep tissue penetration and endowing them with the ability to act as photothermal transducers as well. In this study, we optimized a simple and novel method for synthesizing folate-receptor-targeted-plasmonic silver-nanoparticles (QRC-FA-AgNPs) to serve as an efficient nanoscopic carrier system for breast cancer-cell targeted delivery of QRC and to induce photothermal therapy. A one-pot chemical synthesis method was followed for synthesizing the QRC-FA-AgNPs by finely tailoring the hydrogen bond between the reductant and stabilizer. Detailed characterization through UV-visible, near infrared (UV-vis-NIR) spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and energy-dispersive X-ray spectroscopy (EDX), along with particle-size, zeta-potential analysis, drug-loading and release capacity and stability studies were also performed. In vitro targeted cellular uptake, viability studies, chemo-photothermal efficacy, induction of apoptosis and the reactive oxygen species (ROS) generating potential were studied in the MDA-MB-231 cell-line and in vivo evaluation of the chemo-photothermal efficacy of QRC-FA-AgNPs was performed using a 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast-carcinogenesis model in Sprague Dawley rats. Unlike conventional AgNPs, these novel pentagonal QRC-FA-AgNPs (<50 nm) manifested a robust plasmon tunability in the NIR (>800 nm) region. Detailed in vitro and in vivo studies revealed their active role in improving breast-cancer conditions by allowing controlled and targeted discharge of QRC at the tumor site, along with evoking hyperthermia under NIR laser irradiation that induced selective ablation of cancer cells. Following successful cellular internalization, the photothermal efficacy of QRC-FA-AgNPs supplemented their chemotherapeutic potency, allowing apoptosis and restraining the tumor growth. This current study highlighted the augmented efficacy of plasmonic QRC-FA-AgNPs in comparison to free quercetin, thus the development of a potential nanocarrier based on the pleiotropic function of plasmonic AgNPs may provide an efficient combined chemo-photothermal based strategy for the assassination of breast-cancer cells.

Quinazolinone derivative BNUA-3 ameliorated [NDEA+2-AAF]-induced liver carcinogenesis in SD rats by modulating AhR-CYP1B1-Nrf2-Keap1 pathway.

Cytochrome P450 1B1, considered as one of the novel chemotherapeutic targets involved in cancer prevention and therapy is also associated with the conversion of procarcinogens into their active metabolites. The aryl hydrocarbon receptor (AhR) is responsible for mediating different biological responses to a wide variety of environmental pollutants and also causes transcriptional activation of cytochrome P450 enzymes including CYP1B1 and thus plays a pivotal role for initiating cancer and its progression. On the other hand, active carcinogenic metabolites and reactive oxygen species-mediated stress alter different molecular signalling pathways and gene expressions. Quinazoline derivatives are recognized for their diversified biological activities including anticancer properties. The current study was designed for evaluation of chemotherapeutic efficacy of a synthetic quinazolinone derivative BNUA-3 against hepatocellular cancer in Sprague-Dawley (SD) rats. A detailed in vivo analysis was performed by administrating BNUA-3 (15, 30 mg/kg b.w. for 28 days, i.p.) in N-Nitrosodiethylamine + 2-Acetylaminofluorene induced partially hepatectomized liver cancer in SD rats. This was followed by morphological evaluations, biochemical estimations and analysis of different mRNA and protein expressions. The results demonstrated the potency of BNUA-3 in efficient restoration of the altered morphology of liver, its protective effect against lipid peroxidation, enzymic and non-enzymic antioxidants levels in liver tissue which was disrupted after cancer induction. The study also demonstrated downregulation of AhR, CYP1B1 and Keap1 expressions with subsequent augmentation of protective Nrf2, HO-1, NQO1 and GSTA1 expressions thus, revealing the chemotherapeutic potency of BNUA-3 in inhibiting liver carcinogenesis through AhR/CYP1B1/Nrf2/Keap1 pathway.

Taxifolin binds with LXR (α & ß) to attenuate DMBA-induced mammary carcinogenesis through mTOR/Maf-1/PTEN pathway.

AIM: 7,12-dimethylbenz(a)anthracene(DMBA), a PAH derivative initializes cascades of signaling events that alters a variety of enzymes responsible for lipid and glucose homeostasis resulting in enhanced availability and consumption of energy producing molecules for the development of carcinogenesis. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR) is a key enzyme regulating the pathway of synthesis of cholesterol whereas liver-X-receptor (LXR) regulates lipid, carbohydrate metabolism in various malignancies including mammary carcinogenesis (MC). In this study Taxifolin (TAX), a potential flavanoid has been subjected to evaluate its anti-cancer potential on (MC). METHODS: We designed to screen the molecular docking analysis of TAX on LXRα, LXRß, HMG-CoAR, mTOR and PTEN using MAESTRO tool comparing with their reference ligands. MC was developed by the administration of DMBA in the air pouch (under the mammary fat pad) of the female Sprague-Dawley rats (55 days old). After 90 days of cancer induction, the chemotherapeutic potential of TAX was evaluated by administering TAX at different doses (10, 20 and 40 mg/kg b.w./day). Then western blot and RT-qPCR analysis were performed for determination of the protein and mRNA expressions respectively. RESULTS: The docking analysis revealed significant interaction with LXR (α&ß), HMG-CoAR, mTOR and PTEN. The docking results were validated with the enzyme inhibition assay using HMG-CoAR (EC 1.1.1.34). TAX inhibited the HMG-CoAR activity with an IC50 value of 97.54 ±â€¯2.5 nM whereas the reference molecule pavastatin revealed an IC50 value of 84.35 ±â€¯1.2 nM. Moreover, TAX modulated the energy regulation on DMBA-induced MC in SD-rats by significantly restoring the cancer-induced alterations in body weight, tumor growth and lipid, lipoproteins, lipid metabolizing enzymes and glycolytic enzymes. TAX interacted with LXRs, HMG-CoAR, metabolic enzymes and restored the altered metabolism that accelerates uncontrolled cell proliferation in MC. Moreover, TAX also altered the mRNA and protein expressions of HMG-CoAR, LXR (α,ß), Maf1, PTEN, phosphoinositide 3-kinase (PI3K), Akt, mTOR, fatty acid synthase (FASN) and acetyl-CoA carboxylase 1 (ACC1) in a dose dependent manner. CONCLUSION: These results validate the anti-cancer potential of TAX in DMBA-induced MC through LXR-mTOR/Maf1/PTEN axis.

7.8-Dihydroxycoumarin exerts antitumor potential on DMBA-induced mammary carcinogenesis by inhibiting ERalfa, PR, EGFR, and IGF1R: involvement of MAPK1/2-JNK1/2-Akt pathway

Breast cancer (BC) is a persistent and impulsive metabolic disorder with the highest prevalence in women, worldwide. 7,12-Dimethylbenz(a)anthracene (DMBA) is a potent polyaromatic hydrocarbon (PAH)-based carcinogen producing mammary carcinomas in rats resembling the human hormone-dependent BC. 7,8-Dihydroxycoumarin (78DC) is a coumarin derivative that possesses diversified and favorable pharmacology profile to be considered in anticancer research against various malignancies. The present study was intended to investigate the antiproliferative and chemotherapeutic potentials of 78DC (20, 40, and 80 mg/kg BW) against DMBA (20 mg in olive oil)-induced mammary carcinoma Sprague-Dawley rats. We established the in silico approach for evaluation of the effect of 78DC on hormonal (estrogen receptor-α (ERα), progesterone receptor (PR)), growth factor receptors (EGFR and IGFR), 17Beta-hydroxysteroid dehydrogenase type 1 (17Beta -HD1), and aromatase. Effect of 78DC on estrogen synthesis, tumor growth, proliferation markers (Ki-67 and PCNA), cytokines (IL-10, IL-1 Beta, IL-12), chemokine (MCP-1), and cellular expressions of ERα, PR, EGFR, IGF1R, p-MAPK1/2, p-JNK1/2, p-Akt, 17Beta-HD1, and aromatase was evaluated in mammary carcinoma bearing SD rats. DMBA induces large tumor burden and histological alterations in mammary gland with a subsequent increase in ERα, PR, EGFR, IGF1R, Ki-67, proliferating cell nuclear antigen (PCNA ), cytokines, and chemokine expressions. This was also correlated with the changes in rapid cell differentiation and proliferation. In contrast, 78DC treatment to the cancer-bearing animals abbreviated these changes and revealed to possess antitumorigenic and antiproliferative potentials. Further, a significant decrease in expressions of ERα, PR, EGFR, IGFR, p-MAPK1/2, p-JNK1/2, p-Akt, 17Beta-HD1, and aromatase signifies a reduction in estrogen sensitivity and secondary signaling pathways that may contribute to the prevention of tumor growth. The current findings revealed that 78DC potentially reduce cancer cell proliferation and reverted mammary cancer-induced changes in experimental animals in a dose-dependent manner

7,8-Dihydroxycoumarin exerts antitumor potential on DMBA-induced mammary carcinogenesis by inhibiting ERα, PR, EGFR, and IGF1R: involvement of MAPK1/2-JNK1/2-Akt pathway.

Breast cancer (BC) is a persistent and impulsive metabolic disorder with the highest prevalence in women, worldwide. 7,12-Dimethylbenz(a)anthracene (DMBA) is a potent polyaromatic hydrocarbon (PAH)-based carcinogen producing mammary carcinomas in rats resembling the human hormone-dependent BC. 7,8-Dihydroxycoumarin (78DC) is a coumarin derivative that possesses diversified and favorable pharmacology profile to be considered in anticancer research against various malignancies. The present study was intended to investigate the antiproliferative and chemotherapeutic potentials of 78DC (20, 40, and 80 mg/kg BW) against DMBA (20 mg in olive oil)-induced mammary carcinoma Sprague-Dawley rats. We established the in silico approach for evaluation of the effect of 78DC on hormonal (estrogen receptor-α (ERα), progesterone receptor (PR)), growth factor receptors (EGFR and IGFR), 17ß-hydroxysteroid dehydrogenase type 1 (17ß-HD1), and aromatase. Effect of 78DC on estrogen synthesis, tumor growth, proliferation markers (Ki-67 and PCNA), cytokines (IL-10, IL-1ß, IL-12), chemokine (MCP-1), and cellular expressions of ERα, PR, EGFR, IGF1R, p-MAPK1/2, p-JNK1/2, p-Akt, 17ß-HD1, and aromatase was evaluated in mammary carcinoma bearing SD rats. DMBA induces large tumor burden and histological alterations in mammary gland with a subsequent increase in ERα, PR, EGFR, IGF1R, Ki-67, proliferating cell nuclear antigen (PCNA ), cytokines, and chemokine expressions. This was also correlated with the changes in rapid cell differentiation and proliferation. In contrast, 78DC treatment to the cancer-bearing animals abbreviated these changes and revealed to possess antitumorigenic and antiproliferative potentials. Further, a significant decrease in expressions of ERα, PR, EGFR, IGFR, p-MAPK1/2, p-JNK1/2, p-Akt, 17ß-HD1, and aromatase signifies a reduction in estrogen sensitivity and secondary signaling pathways that may contribute to the prevention of tumor growth. The current findings revealed that 78DC potentially reduce cancer cell proliferation and reverted mammary cancer-induced changes in experimental animals in a dose-dependent manner.

Wound Healing Activity of Silibinin in Mice.

BACKGROUND: Silibinin is a semi-purified fraction of silymarin contained in milk thistle (Silybum marianum Asteraceae). Primarily known for its hepatoprotective actions, silymarin may also stimulate epithelialization and reduce inflammation in excision wound. Previous studies show antioxidant, anti-inflammatory, and antimicrobial actions of silibinin. However, wound healing property of silibinin is not well studied. OBJECTIVE: This study investigates wound healing activity of silibinin topical formulation. MATERIALS AND METHODS: Wound healing activity of 0.2% silibinin gel was assessed by incision and excision wound models in mice. Animals were divided into gel base, silibinin gel, and Mega Heal gel® treated groups with six animals in each group. Wound contraction, wound tissue tensile strength, and hydroxyproline content were measured, and histopathological evaluation of wound tissue of all the above treatment groups was carried out. RESULTS: Application of 0.2% silibinin hydrogel for 8 days led to 56.3% wound contraction compared to 64.6% using standard Mega Heal gel with a subsequent increase in hydroxyproline content, which was significantly higher (P < 0.001) over control animals showing 33.2% contraction. After 14 days, percentage of contraction reached 96.1%, 97.6%, and 86.7%, respectively. Wound tissue tensile strength with silibinin (223.55 ± 3.82 g) and standard (241.38 ± 2.49 g) was significantly higher (P < 0.001) than control (174.06 ± 5.75 g). Histopathology of silibinin and standard gel treated wound tissue showed more fibroblasts, fewer macrophage infiltration, and well-formed collagen fibers. CONCLUSION: Here, we show potent wound healing activity of silibinin hydrogel formulation. SUMMARY: 0.2% silibinin hydrogel showed potent wound healing activity in incision and excision wound models in mice. Abbreviations Used: ROS: Reactive oxygen species.

Daphnetin ameliorates 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis through Nrf-2-Keap1 and NF-κB pathways.

Cancer is a faction of disorders that conjugated primarily with oxidative imbalance. In mammary carcinoma, oxidative stress secondarily changes various gene expressions and signalling pathways that bring genomic instability and mutagenic alterations that fascinating carcinogenesis. Several coumarin compounds are active against various malignancies. Among them, daphnetin (DAP) exhibits valuable safety and bioactivity profile that contributes towards its efficacy against cancer. In this study, the antioxidative and chemotherapeutic potential of DAP against 7,12-dimethylbenz(a)anthracene (DMBA)- induced mammary carcinogenesis was evaluated in female Sprague-Dawley rats. Besides this, we have determined the effect of DAP on Keap1-Nrf-2, associated HO-1 and NF-κB expressions behind the antioxidative and anti-proliferating activity. In our findings, a protective effect of DAP was established against lipid peroxidation, enzymic (Total SOD, MnSOD, CuZnSOD, CAT, GPx) and non-enzymic (GSH) antioxidative markers in serum, liver, kidney and breast tissue of both control and experimental groups. An up-regulation of protective Nrf-2 & HO-1 with a synchronized suppression in Keap1 & NF-κB mRNA and protein expressions were observed. DAP revealed the inhibition of p-AKT which accountable for decrease in NF-κB expressions but shown to be ineffective on p-ERK1/2. This study revealed that DAP inhibits mammary carcinogenesis through multiple mechanisms. Dual efficacy of DAP on Nrf-2-Keap1 pathway and NF-κB expressions propose it as a potential chemotherapeutic agent in mammary cancer management.

mTOR activation promotes plasma cell differentiation and bypasses XBP-1 for immunoglobulin secretion.

Plasma cells (PCs) are responsible for the secretion of antibodies. The development of fully functional PCs relies on the activation of the inositol-requiring enzyme 1/X-box binding protein 1 (IRE1/XBP-1) arm of the unfolded protein response (UPR). XBP-1-deficient PCs secrete antibodies poorly and exhibit distensions of the endoplasmic reticulum (ER). The kinase mammalian target of rapamycin (mTOR) promotes anabolic activities and is negatively regulated by the tuberous sclerosis complex (TSC). Deletion of TSC1 renders mTOR hyperactive. To explore the relationship between mTOR and the UPR in PC development and function, mice with conditional deletions of XBP-1 and/or TSC1 in their B cell lineage were generated. Deletion of TSC1 enhanced Ig synthesis and promoted differentiation into PCs independently of XBP-1, as evidenced by comparison of TSC1/XBP-1 double-knockout (DKO) PCs to XBP-1 knockout (KO) PCs. The typical morphological abnormalities of the ER in XBP-1 KO PCs were alleviated in the DKO PCs. Expression profiling identified the glycoprotein Ly6C as an mTOR target. Ly6C expression contributed to the enhanced Ig secretion from DKO PCs. Our data reveal a functional overlap between mTOR and the UPR in promoting PC development. In addition to the classical mTOR role in promoting protein synthesis, the mechanism entails transcription regulation of accessory molecules, such as Ly6C.