Rhus coriaria suppresses angiogenesis, metastasis and tumor growth of breast cancer through inhibition of STAT3, NFκB and nitric oxide pathways

Carnosol, a Natural Polyphenol, Inhibits Migration, Metastasis, and Tumor Growth of Breast Cancer via a ROS-Dependent Proteasome Degradation of STAT3

We have previously demonstrated that carnosol, a naturally occurring diterpene, inhibited in vitro cell viability and colony growth, as well as induced cell cycle arrest, autophagy and apoptosis in human triple negative breast cancer (TNBC) cells. In the present study, we evaluated the ability of carnosol to inhibit tumor growth and metastasis in vivo. We found that non-cytotoxic concentrations of carnosol inhibited the migration and invasion of MDA-MB-231 cells in wound healing and matrigel invasion assays. Furthermore, gelatin zymography, ELISA, and RT-PCR assays revealed that carnosol inhibited the activity and downregulation the expression of MMP-9. Mechanistically, we demonstrated that carnosol suppressed the activation of STAT3 signaling pathway through a ROS-dependent targeting of STAT3 to proteasome-degradation in breast cancer cells (MDA-MB-231, Hs578T, MCF-7, and T47D). We show that blockade of proteasome activity, by MG-132 and bortezomib, or ROS accumulation, by N-acetylcysteine (NAC), restored the level of STAT3 protein. In addition, using chick embryo tumor growth assay, we showed that carnosol significantly and markedly suppressed tumor growth and metastasis of breast cancer xenografts. To the best of our knowledge, this is the first report which shows that carnosol specifically targets signal transducer and activator of transcription 3 (STAT3) for proteasome degradation in breast cancer. Our study further provide evidence that carnosol may represent a promising therapeutic candidate that canmodulate breast cancer growth and metastasis.

In vitro evidences of the traditional use of Rhus coriaria L. fruits against skin inflammatory conditions

ETHNOPHARMACOLOGICAL RELEVANCE

Rhus coriaria L. (R. coriaria) is a medicinal herb native to the middle east and Mediterranean region and well-known as "sumac" or "sicilian sumac". This herb has a wide range of traditional applications, covering its topical use to treat skin burns or eczemas and to promote wound healing.

AIM OF THE STUDY

The present research aims to investigate the potential anti-inflammatory activity of Rhus coriaria L. fruit extracts in human keratinocytes (HaCaT cells), evaluating extracts prepared using different techniques.

MATERIALS AND METHODS

Water (WRC), ethanol-water (EWRC) and two types of ethanol extracts (mERC and ERC) were prepared. The HaCaT cells were challenged by TNF-α (10 ng/mL) and IL-8, ICAM-1, VEGF, and MMP-9 release, as well as NF-κB translocation, were measured by ELISA assays. The most active extracts were chemically profiled through HPLC-UV-DAD analysis.

RESULTS

Althought all the extracts inhibited the TNF-α-induced IL-8 release, just mERC and EWRC suppressed NF-κB activation, ICAM-1, and MMP-9 secretion. EWRC showed higher inhibition on ICAM-1 and MMP-9 with IC₅₀s of 1.76 ± 0.24 and 1.24 ± 0.33 μg/mL, respectively (mean ± s.d.). On the contrary, mERC significantly decreased VEGF levels whereas EWRC did not show any effect. The HPLC-UV profile of the extracts revealed higher amount of anthocyanins in EWRC in comparison with mERC.

CONCLUSIONS

Our results suggest the potential positive effect of R. coriaria fruit extracts, mostly mERC, as preventive agent in the treatment of keratinocyte inflammation through their inhibitory effect on the production of skin pro-inflammatory mediators.

STAT3 as a potential therapeutic target in triple negative breast cancer: a systematic review

Triple negative breast cancer (TNBC), which is typically lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), represents the most aggressive and mortal subtype of breast cancer. Currently, only a few treatment options are available for TNBC due to the absence of molecular targets, which underscores the need for developing novel therapeutic and preventive approaches for this disease. Recent evidence from clinical trials and preclinical studies has demonstrated a pivotal role of signal transducer and activator of transcription 3 (STAT3) in the initiation, progression, metastasis, and immune evasion of TNBC. STAT3 is overexpressed and constitutively activated in TNBC cells and contributes to cell survival, proliferation, cell cycle progression, anti-apoptosis, migration, invasion, angiogenesis, chemoresistance, immunosuppression, and stem cells self-renewal and differentiation by regulating the expression of its downstream target genes. STAT3 small molecule inhibitors have been developed and shown excellent anticancer activities in in vitro and in vivo models of TNBC. This review discusses the recent advances in the understanding of STAT3, with a focus on STAT3’s oncogenic role in TNBC. The current targeting strategies and representative small molecule inhibitors of STAT3 are highlighted. We also propose potential strategies that can be further examined for developing more specific and effective inhibitors for TNBC prevention and therapy.

Evaluation of in vitro and in vivo genotoxic and antigenotoxic effects of Rhus coriaria

Rhus coriaria has been important in the treatment of many diseases in traditional use. In this content, the genotoxic, antigenotoxic, and oxidative stress effects of methanol extract of R. coriaria (RCE) were investigated in this study. Two hundred fifty, 500, or 750 µg/mL concentrations of RCE were not found to have DNA damaging effect on pET22-b(+) plasmid and were unable to induce micronuclei in human lymphocytes (24 or 48 h treatment period). However, it did not inhibit the genotoxic effect of mitomycin-c (0.25 µg/mL). Cytotoxic effects of RCE were investigated using mitotic index (MI) and nuclear division index (NDI). Five hundred, 1000, and 2000 mg/kg concentrations of RCE did not induce chromosome aberrations in rat bone marrow cells for 12 or 24 h treatment period. In addition, 2000 mg/kg concentration of RCE showed an antigenotoxic effect by decreasing to genotoxic effect of 400 mg/kg urethane at 12 and 24 h treatment periods. RCE showed cytotoxic effects by significantly decreasing NDI. Moreover, RCE increased cytotoxic effect of Mitomycin C (MMC). However, RCE did not induce cytotoxicity in rat bone marrow cells. The highest concentration of RCE reduced total oxidant level in 12 h treatment. Interestingly, the lowest total oxidant level was found in rats blood treated with the lowest concentration RCE and urethane together. Thousand and 2000 mg/kg concentrations of RCE decreased total antioxidant levels of rat blood at 24 h treatment period. Our results showed that RCE possess cytotoxic effect in short-term treatments in vitro. However, it does not demonstrate genotoxic or cytotoxic effects in vivo.

Natural Product Interventions for Chemotherapy and Radiotherapy-Induced Side Effects

Cancer is the second leading cause of death in the world. Chemotherapy and radiotherapy are the common cancer treatments. However, the development of adverse effects resulting from chemotherapy and radiotherapy hinders the clinical use, and negatively reduces the quality of life in cancer patients. Natural products including crude extracts, bioactive components-enriched fractions and pure compounds prepared from herbs as well as herbal formulas have been proved to prevent and treat cancer. Of significant interest, some natural products can reduce chemotherapy and radiotherapy-induced oral mucositis, gastrointestinal toxicity, hepatotoxicity, nephrotoxicity, hematopoietic system injury, cardiotoxicity, and neurotoxicity. This review focuses in detail on the effectiveness of these natural products, and describes the possible mechanisms of the actions in reducing chemotherapy and radiotherapy-induced side effects. Recent advances in the efficacy of natural dietary supplements to counteract these side effects are highlighted. In addition, we draw particular attention to gut microbiotan in the context of prebiotic potential of natural products for the protection against cancer therapy-induced toxicities. We conclude that some natural products are potential therapeutic perspective for the prevention and treatment of chemotherapy and radiotherapy-induced side effects. Further studies are required to validate the efficacy of natural products in cancer patients, and elucidate potential underlying mechanisms.

Rhus coriaria L. (Sumac) Evokes Endothelium-Dependent Vasorelaxation of Rat Aorta: Involvement of the cAMP and cGMP Pathways

Rhus coriaria L. (sumac) is widely used in traditional remedies and cuisine of countries of the Mediterranean as well as Central and South-West Asia. Administration of sumac to experimental models and patients with diverse pathological conditions generates multi-faceted propitious effects, including the quality as a vasodilator. Together, the effects are concertedly channeled toward cardiovasobolic protection. However, there is paucity of data on the mechanism of action for sumac’s vasodilatory effect, an attribute which is considered to be advantageous for unhealthy circulatory system. Accordingly, we sought to determine the mechanisms by which sumac elicits its vasorelaxatory effects. We deciphered the signaling networks by application of a range of pharmacological inhibitors, biochemical assays and including the quantification of cyclic nucleotide monophosphates. Herein, we provide evidence that an ethanolic extract of sumac fruit, dose-dependently, relaxes rat isolated aorta. The mechanistic effect is achieved via stimulation of multiple transducers namely PI3-K/Akt, eNOS, NO, guanylyl cyclase, cGMP, and PKG. Interestingly, the arachidonic acid pathway (cyclooxygenases), adenylyl cyclase/cAMP and ATP-dependent potassium channels appear to partake in this sumac-orchestrated attenuation of vascular tone. Clearly, our data support the favorable potential cardio-vasculoprotective action of sumac.

The genetic association between iNOS and eNOS polymorphisms and gastric cancer risk: a meta-analysis

Objective

There are a number of susceptible factors for an increased risk of gastric cancer. Nitric oxide (NO) is considered to be associated with the development of a range of cancers. In particular, inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) are known to play a central role in the production of NO. Published studies relating to the association between eNOS rs1799983, rs2070744, and iNOS rs2297518 polymorphisms and the risk of gastric cancer risk are conflicting and inconclusive and require further analysis.

Materials and methods

This study involved a meta-analysis of case–control studies relating to eNOS rs1799983, rs2070744, and iNOS rs2297518 polymorphisms published prior to January 2018. Literature searches were carried out in PubMed, Embase, Web of Science, the Cochrane Library databases, and the Chinese National Knowledge Infrastructure. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of association based on genotype data.

Results

A total of 1,356 cases and 1,791 controls were included from nine case–control studies involving eNOS rs1799983 (G894T), rs2070744 (T-786C), and iNOS rs2297518 (C150T) polymorphisms. Data analysis indicated that iNOS rs2297518 was a risk factor for Helicobacter pylorus-positive gastric cancer when compared with H. pylorus-negative gastric cancer (p=0.003, OR [95% CI] =2.19 [1.31–3.66]). In addition, the allelic, dominant, and recessive models of eNOS rs2070744 were significantly associated with a risk of gastric cancer (allelic model: p<0.00001, OR [95% CI] =0.23 [0.16–0.34]; dominant model: p<0.00001, OR [95% CI] =0.25 [0.15–0.42]; recessive model: p<0.00001, OR [95% CI] =0.16 [0.08–0.30]). No association was identified between eNOS rs1799983 and the risk of gastric cancer (p>0.05).

Conclusion

iNOS rs2297518 and eNOS rs2070744 polymorphisms may represent susceptible factors for gastric cancer.

Euterpe oleracea extract inhibits tumorigenesis effect of the chemical carcinogen DMBA in breast experimental cancer

Background

Among the processes involved in the breast tumor microenvironment, angiogenesis and inflammation play a central role, and the main factors of these processes are the vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2) and macrophages. Recently, the extract of Euterpe oleracea (açaí), a fruit that is widely found in the Amazon region, already showed antitumorigenic effects in vitro in human breast cancer cell lines. The present study aimed to investigate the effect of açaí on breast cancer using a chemically DMBA (7,12-dimethylbenzanthracene) experimental model.

Methods

One day after initiation of treatment with açaí, mammary carcinogenesis was induced in female Wistar rats using a subcutaneous injection of 25 mg/kg of DMBA in the mammary gland. Forty rats were randomized into two groups: treated with 200 mg/kg of either açaí extract or vehicle, via gastric tube for 16 consecutive weeks. After treatment, the tumor was collected for macroscopic, histological and immunohistochemical (VEGF, vascular endothelial growth factor receptor 2 -VEGFR-2, COX-2 and matrix metalloproteinase -MMP-9) analyses; peritoneal fluid was subjected to flow cytometry (F4–80/MAC-2+) and ELISA immunoassay (VEGF, prostaglandin E₂ -PGE₂ and interleukin-10 -IL-10). Heart, liver and kidney samples were collected for histological analysis.

Results

After 16 weeks of induction, the mammary carcinoma was confirmed by macroscopic and histological evaluation. Survival analysis indicates that açaí increased the survival (P = .0002, long-rank test) and reduced the deaths number (P = .0036, Chi-square test). Açaí treatment decreased the number of inflammatory cells and macrophage positive cells (Mac-2 + F4–80+), as well as promoting a reduction in immunostaining of VEGF, VEGFR-2 and COX-2. The açaí group also exhibited lower concentrations of PGE₂, VEGF and IL-10 compared to the control. The histopathological results of the liver and kidneys showed protective effect of açaí, since in the control group, there was an increase in fibrosis, atypical cells and hemorrhagic microenvironment.

Conclusion

The results of this study demonstrated the antiangiogenic and anti-inflammatory potential of açaí, like due to the decreases of the number of activated macrophages, resulting in the inhibition of DMBA carcinogenicity in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2183-z) contains supplementary material, which is available to authorized users.

Role of Chemokines in Thyroid Cancer Microenvironment: Is CXCL8 the Main Player?

Tumor-related inflammation does influence the biological behavior of neoplastic cells and ultimately the patient's outcome. With specific regard to thyroid cancer, the issue of tumor-associated inflammation has been extensively studied and recently reviewed. However, the role of chemokines, which play a crucial role in determining the immuno-phenotype of tumor-related inflammation, was not addressed in previous reviews on the topic. Experimental evidence shows that thyroid cancer cells actively secrete a wide spectrum of chemokines and, at least for some of them, solid scientific data support a role for these immune-active molecules in the aggressive behavior of the tumor. Our proposal for a review article on chemokines and thyroid cancer stems from the notion that chemokines, besides having the ability to attract and maintain immune cells at the tumor site, also produce several pro-tumorigenic actions, which include proangiogenetic, cytoproliferative, and pro-metastatic effects. Studies taking into account the role of CCL15, C-X-C motif ligand 12, CXCL16, CXCL1, CCL20, and CCL2 in the context of thyroid cancer will be reviewed with particular emphasis on CXCL8. The reason for focusing on CXCL8 is that this chemokine is the most studied one in human malignancies, displaying multifaceted pro-tumorigenic effects. These include enhancement of tumor cells growth, metastatization, and angiogenesis overall contributing to the progression of several cancers including thyroid cancer. We aim at reviewing current knowledge on the (i) ability of both normal and tumor thyroid cells to secrete CXCL8; (ii) direct/indirect pro-tumorigenic effects of CXCL8 demonstrated by in vitro and in vivo studies specifically performed on thyroid cancer cells; and (iii) pharmacologic strategies proven to be effective for lowering CXCL8 secretion and/or its effects on thyroid cancer cells.

Moderate intermittent negative pressure increases invasiveness of MDA-MB-231 triple negative breast cancer cells

BACKGROUND

To investigate the effect moderate intermittent negative pressure breast reconstructive model exerts on human triple negative breast cancer cell (TNBC) invasion and explore the related mechanism.

METHODS

The human TNBC cell line MDA-MB-231 was used. Cells in external volume expansion (EVE) group were exposed to an intermittent -25 mmHg for 12 h; the pressure for non-EVE group was constantly 0 mmHg. In vivo, MDA-MB-231 cell suspensions were injected subcutaneously into dorsal skin of nude mice (n = 27 mice/group). Tumors on mice in EVE group received -25 mmHg suction 3 h/day; while mice in non-EVE group were under normal pressure. Cell invasion assay, ELISA, RT-PCR, western blot analysis and immunohistochemistry were used to evaluate the inflammation, epithelial-mesenchymal transition (EMT) and angiogenesis between the two groups in both vitro and vivo experiments.

RESULTS

MDA-MB-231 cells in the EVE group were more invasive and had higher expressions of IL-8 (30.02 ± 10.44 pg/ml vs. 18.82 ± 9.26 pg/ml, P < 0.05) and TNF-α (20.59 ± 4.72 pg/ml vs. 14.10 ± 3.36 pg/ml, P < 0.05) than the non-EVE group. Grafted MDA-MB-231 tumors in EVE group showed a more obvious epithelial-mesenchymal transition at 2 week and better angiogenesis at 2 and 4 week, respectively.

CONCLUSION

Moderate intermittent negative pressure induces MDA-MB-231 cells to be more invasive. Future studies should figure out other effects this intervention may bring. Clinical studies should also be conducted to further evaluate its safety and optimize the clinical model.

Rhus coriaria increases protein ubiquitination, proteasomal degradation and triggers non-canonical Beclin-1-independent autophagy and apoptotic cell death in colon cancer cells

Colorectal cancer is the fourth leading cause of cancer-related deaths worldwide. Here, we investigated the anticancer effect of Rhus coriaria extract (RCE) on HT-29 and Caco-2 human colorectal cancer cells. We found that RCE significantly inhibited the viability and colony growth of colon cancer cells. Moreover, RCE induced Beclin-1-independent autophagy and subsequent caspase-7-dependent apoptosis. Blocking of autophagy by chloroquine significantly reduced RCE-induced cell death, while blocking of apoptosis had no effect on RCE-induced cell death. Mechanistically, RCE inactivated the AKT/mTOR pathway by promoting the proteasome-dependent degradation of both proteins. Strikingly, we also found that RCE targeted Beclin-1, p53 and procaspase-3 to degradation. Proteasome inhibition by MG-132 not only restored these proteins to level comparable to control cells, but also reduced RCE-induced cell death and blocked the activation of autophagy and apoptosis. The proteasomal degradation of mTOR, which occurred only 3 hours post-RCE treatment was concomitant with an overall increase in the level of ubiquitinated proteins and translated stimulation of proteolysis by the proteasome. Our findings demonstrate that Rhus coriaria possesses strong anti-colon cancer activity through stimulation of proteolysis as well as induction of autophagic and apoptotic cell death, making it a potential and valuable source of novel therapeutic cancer drug.

Identification of pyrrolopyrimidine derivative PP-13 as a novel microtubule-destabilizing agent with promising anticancer properties

Despite the emergence of targeted therapies and immunotherapy, chemotherapy remains the gold-standard for the treatment of most patients with solid malignancies. Spindle poisons that interfere with microtubule dynamics are commonly used in chemotherapy drug combinations. However, their troublesome side effects and the emergence of chemoresistance highlight the need for identifying alternative agents. We performed a high throughput cell-based screening and selected a pyrrolopyrimidine molecule (named PP-13). In the present study, we evaluated its anticancer properties in vitro and in vivo. We showed that PP-13 exerted cytotoxic effects on various cancer cells, including those resistant to current targeted therapies and chemotherapies. PP-13 induced a transient mitotic blockade by interfering with both mitotic spindle organization and microtubule dynamics and finally led to mitotic slippage, aneuploidy and direct apoptotic death. PP-13 was identified as a microtubule-targeting agent that binds directly to the colchicine site in β-tubulin. Interestingly, PP-13 overcame the multidrug-resistant cancer cell phenotype and significantly reduced tumour growth and metastatic invasiveness without any noticeable toxicity for the chicken embryo in vivo. Overall, PP-13 appears to be a novel synthetic microtubule inhibitor with interesting anticancer properties and could be further investigated as a potent alternative for the management of malignancies including chemoresistant ones.

NF-κB Signalling in Glioblastoma

Nuclear factor-κB (NF-κB) is a transcription factor regulating a wide array of genes mediating numerous cellular processes such as proliferation, differentiation, motility and survival, to name a few. Aberrant activation of NF-κB is a frequent event in numerous cancers, including glioblastoma, the most common and lethal form of brain tumours of glial cell origin (collectively termed gliomas). Glioblastoma is characterized by high cellular heterogeneity, resistance to therapy and almost inevitable recurrence after surgery and treatment. NF-κB is aberrantly activated in response to a variety of stimuli in glioblastoma, where its activity has been implicated in processes ranging from maintenance of cancer stem-like cells, stimulation of cancer cell invasion, promotion of mesenchymal identity, and resistance to radiotherapy. This review examines the mechanisms of NF-κB activation in glioblastoma, the involvement of NF-κB in several mechanisms underlying glioblastoma propagation, and discusses some of the important questions of future research into the roles of NF-κB in glioblastoma.

Salvia fruticosa Induces Vasorelaxation In Rat Isolated Thoracic Aorta: Role of the PI3K/Akt/eNOS/NO/cGMP Signaling Pathway

Salvia fruticosa (SF) Mill. is traditionally used for its antihypertensive actions. However, little is known about its pharmacologic and molecular mechanisms of action. Here we determined the effects of an ethanolic extract of SF leaves on rings of isolated thoracic aorta from Sprague-Dawley rats. Our results show that SF extract increased nitric oxide production and relaxed endothelium-intact rings in a dose-dependent (0.3 µg/ml–1 mg/ml) manner, and the maximum arterial relaxation (R_max) was significantly reduced with endothelium denudation. Pretreatment of endothelium-intact rings with L-NAME (a non-selective inhibitor of nitric oxide synthase, 100 µM), or ODQ (an inhibitor of soluble guanylyl cyclase, 10 µM) significantly diminished SF-mediated vasorelaxation. Furthermore, SF induced Akt phosphorylation as well as increased cGMP levels in rings treated with increasing doses of SF. Prior exposure to PI3K inhibitors, wortmannin (0.1 µM) or LY294002 (10 µM), decreased cGMP accumulation and attenuated the SF-induced vasorelaxation by approximately 50% (R_max). SF-evoked relaxation was not affected by indomethacin, verapamil, glibenclamide, tetraethylammonium, pyrilamine or atropine. Taken together, our results indicate that SF induces endothelium-dependent vasorelaxation through the PI3K/Akt/eNOS/NO/sGC/cGMP signaling pathway. Our data illustrate the health-orientated benefits of consuming SF which may act as an antihypertensive agent to reduce the burden of cardiovascular complications.

27-Hydroxycholesterol induces invasion and migration of breast cancer cells by increasing MMP9 and generating EMT through activation of STAT-3

Breast carcinoma plays a vital role in the reasons of global women's death. ER-related invasion and migration play an important part in the development and prognosis of breast cancer. Here, we found that 27-Hydroxycholesterol (27HC) could induce epithelial-mesenchymal transition (EMT) and increase the expression of the matrix metalloproteinase 9 (MMP9) at mRNA level and the active form. Meanwhile, interestingly, we found 27HC activated signal transducer and activator of transcription 3 (STAT-3) in ER positive cells except activation of ER signaling. Furthermore, inhibition of STAT-3 by siRNA attenuated the 27HC-induced improvement of MMP9 and decreased the invasion and migration ability in MCF7 and T47D cells. In addition, 27HC could also promote MMP9, vimentin and active STAT-3 in the ER negative cells MDA-MB-231. All these results not only raise a mechanism whereby 27HC enhances the invasion and metastasis, but also is helpful to realize 27HC as a potential endogenous detrimental factor in breast tumor patients.

Specificity of Hydrolysable Tannins from Rhus typhina L. to Oxidants in Cell and Cell-Free Models

Polyphenols of plant origin with wide range of antiradical activity can prevent diseases caused by oxidative and inflammatory processes. In this study, we show using ESR method that the purified water-soluble extract from leaves of Rhus typhina L. containing hydrolysable tannins and its main component, 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-β-D-glucose (C₅₅H₄₀O₃₄), displayed a strong antiradical activity against the synthetic 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in homogenous (solution) and heterogeneous systems (suspension of DPPH containing liposomes) in the range of 1-10 μg/ml. The C₅₅H₄₀O₃₄ and extract at 1-30 μg/ml also efficiently, but to a various degree, decreased reactive oxygen and nitrogen species (RONS) formation induced in erythrocytes by oxidants, following the sequence: tert-butyl hydroperoxide (tBuOOH) > peroxynitrite (ONOO^-) >hypochlorous acid (HClO). The explanation of these differences should be seen in the specificity of scavenging different RONS types. These relationships can be represented for C₅₅H₄₀O₃₄ and the extract by the following order of selectivity: O^.-₂ ≥ NO· > ·OH > ¹O₂. The extract exerted a more pronounced antiradical effect in reaction with DPPH and ROS in all models of oxidative stress in erythrocytes in comparison with C₅₅H₄₀O₃₄. The redox processes between the extract components and their specificity in relation to RONS can underlie this effect.

Targeted delivery of quercetin loaded mesoporous silica nanoparticles to the breast cancer cells

BACKGROUND

Mesoporous silica nanoparticles (MSNs) have been promising vehicles for drug delivery. Quercetin (Q), a natural flavonoid, has been reported to have many useful effects. However, poor water solubility as well as less bioavailability has confined its use as a suitable anti-cancer drug. Therefore, profound approach is required to overcome these drawbacks.

METHODS

We have synthesized folic acid (FA) armed mesoporous silica nanoparticles (MSN-FA-Q) loaded with quercetin and then characterized it by DLS, SEM, TEM and FTIR. MTT, confocal microscopy, flow cytometry, scratch assay and immunoblotting were employed to assess the cell viability, cellular uptake, cell cycle arrest, apoptosis, wound healing and the expression levels of different signalling molecules in breast adenocarcinoma cells. Nanoparticle distribution was investigated by using ex vivo optical imaging and CAM assay was employed to assess tumor regression.

RESULTS

MSN-FA-Q facilitates higher cellular uptake and allows more drug bioavailability to the breast cancer cells with over-expressed folate receptors. Our experimental results suggest that the newly synthesized MSN-FA-Q nanostructure caused cell cycle arrest and apoptosis in breast cancer cells through the regulation of Akt & Bax signalling pathways. Besides, we also observed that MSN-FA-Q has a concurrent anti-migratory role as well.

CONCLUSION

This uniquely engineered quercetin loaded mesoporous silica nanoparticle ensures a targeted delivery with enhanced bioavailability.

GENERAL SIGNIFICANCE

Effective targeted therapeutic strategy against breast cancer cells.

SMARCAD1 knockdown uncovers its role in breast cancer cell migration, invasion, and metastasis

OBJECTIVE

Breast cancer is the most common cancer seen in women worldwide and breast cancer patients are at high risk of recurrence in the form of metastatic disease. Identification of genes associated with invasion and metastasis is crucial in order to develop novel anti-metastasis targeted therapy. It has been demonstrated that the DEAD-BOX helicase DP103 was implicated in breast cancer invasion and metastasis. SMARCAD1 is also a DEAD/H box-containing helicase, suggested to play a role in genetic instability. However, its involvement in cancer migration, invasion, and metastasis has never been explored.

RESEARCH DESIGN AND METHODS

Using two different designs of shRNA targeting SMARCAD1, we investigated the impact of SMARCAD1 knockdown on the migration, invasion, and metastasis potential of the breast cancer cells MDA-MB-231 and T47D.

RESULTS

We observed that SMARCAD1 knockdown in the invasive breast cancer cells MDA-MB-231, unlike in the non-invasive breast cancer cells T47D, was associated with an increased cell-cell adhesion and a significant decrease in cell migration, invasion, and metastasis due at least in part to a strong inhibition of STAT3 phosphorylation.

CONCLUSIONS

These results indicate that SMARCAD1 is involved in breast cancer metastasis and can be a promising target for metastatic breast cancer therapy.