下调lncRNA MCF2L-AS1靶向miR-33b-5p抑制胃癌细胞增殖、迁移、侵袭并促进凋亡

摘要 目的：探讨lncRNA MCF2L-AS1对胃癌细胞恶性生物学行为的影响及分子机制。方法：选取45例胃癌患者的癌组织及癌旁正常组织,或培养胃黏膜上皮细胞GES-1、胃癌细胞HGC-27,采用RT-qPCR检测MCF2L-AS1和miR-33b-5p的表达水平。采用双荧光素酶报告实验检测MCF2L-AS1和miR-33b-5p的靶向关系。将HGC-27细胞分为si-NC组、si-MCF2L-AS1组、mimic NC组、miR-33b-5p mimic组、si-MCF2L-AS1+inhibitor NC组、si-MCF2L-AS1+miR-33b-5p inhibitor组,分别转染si-NC、si-MCF2L-AS1、mimic NC、miR-33b-5p mimic或共转染si-MCF2L-AS1+inhibitor NC、si-MCF2L-AS1+miR-33b-5p inhibitor。采用MTT实验检测细胞增殖情况,流式细胞术检测细胞凋亡率,克隆形成实验检测细胞克隆形成数,Transwell实验检测迁移和侵袭细胞数。结果：与癌旁正常组织或GES-1细胞相比,胃癌组织或HGC-27细胞中MCF2L-AS1表达水平升高、miR-33b-5p表达水平降低,差异均有统计学意义（P<0.05）。MCF2L-AS1可靶向调控miR-33b-5p。下调MCF2L-AS1或过表达miR-33b-5p,miR-33b-5p表达水平升高,HGC-27细胞凋亡率升高,但细胞增殖、克隆形成数、迁移和侵袭数均减少,差异均有统计学意义（P<0.05）。抑制miR-33b-5p可减弱下调MCF2L-AS1对HGC-27细胞的生物学作用。结论：下调MCF2L-AS1通过上调miR-33b-5p抑制胃癌细胞增殖、迁移、侵袭并促进凋亡;MCF2L-AS1通过靶向调控miR-33b-5p表达进而参与胃癌细胞的恶性生物学行为。     

MicroRNA-181a suppresses norethisterone-promoted tumorigenesis of breast epithelial MCF10A cells through the PGRMC1/EGFR–PI3K/Akt/mTOR signaling pathway

BackgroundResearch suggests that hormone replacement therapy may increase the risk of breast cancer, and progestins such as norethisterone (NET) play a key role in this phenomenon. We have demonstrated that microRNA-181a (miR-181a) suppresses NET-promoted breast cancer cell survival. Nonetheless, the effects of NET and miR-181a on the tumorigenesis of human breast epithelial cells have not yet been elaborated.MethodsAssays of cell viability, proliferation, migration, apoptosis, and colony formation were performed to investigate the pro-tumorigenesis effect of NET and the effects of miR-181a on human breast epithelial MCF10A cells. The expressions of cell-proliferation-related genes and apoptotic factors were analyzed by quantitative RT-PCR and Western blot in MCF10A cells treated with NET and miR-181a.ResultsNET significantly increased MCF10A cell viability, proliferation, migration, and colony formation, but reduced cellular apoptosis. In addition, NET increased the expression of progesterone receptor membrane component 1 (PGRMC1), EGFR, B-cell lymphoma 2, cyclin D1, and proliferating cell nuclear antigen, but decreased the expression of pro-apoptosis factors, such as Bax, caspase-7, and caspase-9. Overexpression of miR-181a strongly inhibited the effects of NET on MCF10A cells and abrogated NET-stimulated PGRMC1, EGFR, and mTOR expression.ConclusionsActivation of the PGRMC1/EGFR–PI3K/Akt/mTOR signaling pathway is the primary mechanism underlying the pro-tumorigenesis effects of NET on human breast epithelial MCF10A cells. Additionally, miR-181a can suppress the effects of NET on these cells. These data suggest a therapeutic potential for miR-181a in reducing or preventing the risk of breast cancer in hormone replacement therapy using NET.     

DCPIP (2,6-dichlorophenolindophenol) as a genotype-directed redox chemotherapeutic targeting NQO1*2 breast carcinoma

Abstract

Accumulative experimental evidence suggests feasibility of chemotherapeutic intervention targeting human cancer cells by pharmacological modulation of cellular oxidative stress. Current efforts aim at personalization of redox chemotherapy through identification of predictive tumour genotypes and redox biomarkers. Based on earlier research demonstrating that anti-melanoma activity of the pro-oxidant 2,6-dichlorophenolindophenol (DCPIP) is antagonized by cellular NAD(P)H:quinone oxidoreductase (NQO1) expression, this study tested DCPIP as a genotype-directed redox chemotherapeutic targeting homozygous NQO1*2 breast carcinoma, a common missense genotype [rs1800566 polymorphism; NP_000894.1:p.Pro187Ser] encoding a functionally impaired NQO1 protein. In a panel of cultured breast carcinoma cell lines and NQO1-transfectants with differential NQO1 expression levels, homozygous NQO1*2 MDA-MB231 cells were hypersensitive to DCPIP-induced caspase-independent cell death that occurred after early onset of oxidative stress with glutathione depletion and loss of genomic integrity. Array analysis revealed upregulated expression of oxidative (GSTM3, HMOX1, EGR1), heat shock (HSPA6, HSPA1A, CRYAB) and genotoxic stress response (GADD45A, CDKN1A) genes confirmed by immunoblot detection of HO-1, Hsp70, Hsp70B’, p21 and phospho-p53 (Ser15). In a murine xenograft model of human homozygous NQO1*2-breast carcinoma, systemic administration of DCPIP displayed significant anti-tumour activity, suggesting feasibility of redox chemotherapeutic intervention targeting the NQO1*2 genotype.     

PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

Thymoquinone (TQ), a bioactive component of black caraway seed (Nigella sativa) oil, is reported to have antineoplastic properties. In this study we investigated the effect of TQ on a panel of human breast cancer cell lines. Cell viability assays showed that TQ killed T-47D, MDA-MB-231, and MDA-MB-468 cells via p53-independent induction of apoptosis; however, MCF-7 cells were refractory to the cytotoxic action of TQ. Western Blot analysis showed that MCF-7 cells expressed high levels of cytoprotective NADPH quinone oxidoreductase 1 (NQO1), which was responsible for TQ-resistance since inhibition of NQO1 with dicoumarol rendered MCF-7 cells TQ-sensitive. These findings may be clinically important when considering TQ as a possible adjunct treatment for breast cancer since a high percentage of breast tumors express NQO1.     

Breast cancer stem cell-derived extracellular vesicles transfer ARRDC1-AS1 to promote breast carcinogenesis via a miR-4731-5p/AKT1 axis-dependent mechanism

ObjectivesDeregulation of long non-coding RNAs (lncRNAs) has been frequently reported in breast cancer (BC). This goes to show the importance of understanding its significant contribution towards breast carcinogenesis. In the present study, we clarified a carcinogenic mechanism based on the ARRDC1-AS1 delivered by breast cancer stem cells-derived extracellular vesicles (BCSCs-EVs) in BC.MethodsThe isolated and well characterized BCSCs-EVs were co-cultured with BC cells. The expression of ARRDC1-AS1, miR-4731-5p, and AKT1 was determined in BC cell lines. BC cells were assayed for their viability, invasion, migration and apoptosis in vitro by CCK-8, Transwell and flow cytometry, as well as tumor growth in vivo after loss- and gain-of function assays. Dual-luciferase reporter gene, RIP and RNA pull-down assays were performed to determine the interactions among ARRDC1-AS1, miR-4731-5p, and AKT1.ResultsElevation of ARRDC1-AS1 and AKT1 as well as miR-4731-5p downregulation were observed in BC cells. ARRDC1-AS1 was enriched in BCSCs-EVs. Furthermore, EVs containing ARRDC1-AS1 enhanced the BC cell viability, invasion and migration and glutamate concentration. Mechanistically, ARRDC1-AS1 elevated the expression of AKT1 by competitively binding to miR-4731-5p. ARRDC1-AS1-containing EVs were also found to enhance tumor growth in vivo.ConclusionCollectively, BCSCs-EVs-mediated delivery of ARRDC1-AS1 may promote the malignant phenotypes of BC cells via the miR-4731-5p/AKT1 axis.     

Modulation of protein expression levels and DNA methylation status of breast cancer metastasis genes by anthracycline-based chemotherapy and the demethylating agent decitabine

Epigenetic drugs are promising add‐ons to cancer treatment; still, adverse effects concerning tumour promotion have been reported occasionally. In this in vitro study, we investigated the effect of combination treatment of decitabine with anthracycline‐based chemotherapy [5‐fluorouracil plus epirubicine plus cyclophosphamide (FEC)] on viability and metastatic activity of breast cancer cell lines, MDA‐MB‐231 (estrogen receptor‐negative) and MCF‐7 (estrogen receptor‐positive). The effect of decitabine and its combined treatment with FEC on viability of both cancer cell lines was assessed using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazoliumbromide and adenosine triphosphate (ATP) cell survival assays. DNA methylation specific real‐time polymerase chain reaction (PCR) (Methylight®) was employed to document the methylation status of the metastasis‐relevant urokinase‐type plasminogen activator (uPA) and plasminogen activator inhibitor‐I (PAI‐1) genes. Additionally, protein expression levels of uPA and PAI‐1 were determined using enzyme‐linked immunosorbent assays. Invasion capacity of cells was assayed using Matrigel® invasion assay. Decitabine lowered the viability of MCF‐7 cells, although MDA‐MB‐231 cells were not affected. Decitabine did not augment FEC‐mediated cytotoxicity in both cell lines. In MCF‐7 cells, methylation of the uPA and PAI‐1 gene promoter was significantly reduced by decitabine or decitabine plus FEC. Protein levels of uPA and PAI‐1 were induced by all treatments. Decitabine significantly induced the invasion capacity of MCF‐7 cells, whereas all of the drugs resulted in decreased invasion capacity of MDA‐MB‐231. Our results suggest differential effects of single‐dose decitabine and its combination with FEC on the metastatic capacity and survival of breast cancer cell lines endowed with different metastatic behaviour. Copyright © 2011 John Wiley & Sons, Ltd.     

Progranulin Stimulated by LPA Promotes the Migration of Aggressive Breast Cancer Cells

Abstract

Activator and inhibitor roles for the 88-kDa-secreted glycoprotein progranulin (PGRN) have been demonstrated in ovarian cancer cells. Here, we investigated the effects of PGRN in breast cancer migration. Testing MCF7, MDA-MB-453, and MDA-MB-231 human breast cancer cells and the MCF10A breast epithelial cell line, we demonstrate that LPA-induced PGRN stimulation led to a significant increase in cell invasion of MDA-MB-453 and MDA-MB-231 cells only (p < 0.05). Moreover, incubation with an anti-PGRN antibody, an inhibitor of the ERK pathway (PD98059) or both in combination inhibited the ability of MDA-MB-231 cells to invade. Furthermore, the expression of focal adhesion kinases promoted by LPA-induced PGRN was also inhibited by PD98059 alone or in combination with an anti-PGRN antibody (p < 0.05). Taken together, these results suggest that the LPA activation of PGRN involving the ERK pathway is critical to promote MDA-MB-231 breast cancer cell invasion.     

NQO1-activated phenothiazinium redox cyclers for the targeted bioreductive induction of cancer cell apoptosis

Altered redox signaling and regulation in cancer cells represent a chemical vulnerability that can be targeted by selective chemotherapeutic intervention. Here, we demonstrate that 3,7-diaminophenothiazinium-based redox cyclers (PRC) induce selective cancer cell apoptosis by NAD(P)H:quinone oxidoreductase (NQO1)-dependent bioreductive generation of cellular oxidative stress. Using PRC lead compounds including toluidine blue against human metastatic G361 melanoma cells, apoptosis occurred with phosphatidylserine externalization, loss of mitochondrial transmembrane potential, cytochrome c release, caspase-3 activation, and massive ROS production. Consistent with reductive activation and subsequent redox cycling as the mechanism of PRC cytotoxicity, coincubation with catalase achieved cell protection, whereas reductive antioxidants enhanced PRC cytotoxicity. Unexpectedly, human A375 melanoma cells were resistant to PRC-induced apoptosis, and PRC-sensitive G361 cells were protected by preincubation with the NQO1 inhibitor dicoumarol. Indeed, NQO1 specific enzymatic activity was 9-fold higher in G361 than in A375 cells. The critical role of NQO1 in PRC bioactivation and cytotoxicity was confirmed, when NQO1-transfected breast cancer cells (MCF7-DT15) stably overexpressing active NQO1 displayed strongly enhanced PRC sensitivity as compared to vector control-transfected cells with baseline NQO1 activity. Based on the known overexpression of NQO1 in various tumors these findings suggest the feasibility of developing PRC lead compounds into tumor-selective bioreductive chemotherapeutics.     

10H‐3,6‐Diazaphenothiazines triggered the mitochondrial‐dependent and cell death receptor‐dependent apoptosis pathways and further increased the chemosensitivity of MCF‐7 breast cancer cells via inhibition of AKT1 pathways

Breast cancer is one of the leading causes of death in cancer categories, followed by lung, colorectal, and ovarian among the female gender across the world. 10H‐3,6‐diazaphenothiazine (PTZ) is a thiazine derivative compound that exhibits many pharmacological activities. Herein, we proceed to investigate the pharmacological activities of PTZ toward breast cancer MCF‐7 cells as a representative in vitro breast cancer cell model. The PTZ exhibited a proliferation inhibition (IC₅₀ = 0.895 µM) toward MCF‐7 cells. Further, cell cycle analysis illustrated that the S‐phase checkpoint was activated to achieve proliferation inhibition. In vitro cytotoxicity test on three normal cell lines (HEK293 normal kidney cells, MCF‐10A normal breast cells, and H9C2 normal heart cells) demonstrated that PTZ was more potent toward cancer cells. Increase in the levels of reactive oxygen species results in polarization of mitochondrial membrane potential (ΔΨm), together with suppression of mitochondrial thioredoxin reductase enzymatic activity suggested that PTZ induced oxidative damages toward mitochondria and contributed to improved drug efficacy toward treatment. The RT² PCR Profiler Array (human apoptosis pathways) proved that PTZ induced cell death via mitochondria‐dependent and cell death receptor‐dependent pathways, through a series of modulation of caspases, and the respective morphology of apoptosis was observed. Mechanistic studies of apoptosis suggested that PTZ inhibited AKT1 pathways resulting in enhanced drug efficacy despite it preventing invasion of cancer cells. These results showed the effectiveness of PTZ in initiation of apoptosis, programmed cell death, toward highly chemoresistant MCF‐7 cells, thus suggesting its potential as a chemotherapeutic drug.     

The Function of Vacuolar ATPase (V-ATPase) a Subunit Isoforms in Invasiveness of MCF10a and MCF10CA1a Human Breast Cancer Cells

The vacuolar H⁺ ATPases (V-ATPases) are ATP-driven proton pumps that transport protons across both intracellular and plasma membranes. Previous studies have implicated V-ATPases in the invasiveness of various cancer cell lines. In this study, we evaluated the role of V-ATPases in the invasiveness of two closely matched human breast cancer lines. MCF10a cells are a non-invasive, immortalized breast epithelial cell line, and MCF10CA1a cells are a highly invasive, H-Ras-transformed derivative of MCF10a cells selected for their metastatic potential. Using an in vitro Matrigel assay, MCF10CA1a cells showed a much higher invasion than the parental MCF10a cells. Moreover, this increased invasion was completely sensitive to the specific V-ATPase inhibitor concanamycin. MCF10CA1a cells expressed much higher levels of both a1 and a3 subunit isoforms relative to the parental line. Isoforms of subunit a are responsible for subcellular localization of V-ATPases, with a3 and a4 targeting V-ATPases to the plasma membrane of specialized cells. Knockdown of either a3 alone or a3 and a4 together using isoform-specific siRNAs inhibited invasion by MCF10CA1a cells. Importantly, overexpression of a3 but not the other a subunit isoforms greatly increased the invasiveness of the parental MCF10a cells. Similarly, overexpression of a3 significantly increased expression of V-ATPases at the plasma membrane. These studies suggest that breast tumor cells employ particular a subunit isoforms to target V-ATPases to the plasma membrane, where they function in tumor cell invasion.     

Using the MCF10A/MCF10CA1a Breast Cancer Progression Cell Line Model to Investigate the Effect of Active,Mutant Forms of EGFR in Breast Cancer Development and Treatment Using Gefitinib

Background

Basal-like and triple negative breast cancer (TNBC) share common molecular features, poor prognosis and a propensity for metastasis to the brain. Amplification of epidermal growth factor receptor (EGFR) occurs in ~50% of basal-like breast cancer, and mutations in the epidermal growth factor receptor (EGFR) have been reported in up to ~ 10% of Asian TNBC patients. In non-small cell lung cancer several different mutations in the EGFR tyrosine kinase domain confer sensitivity to receptor tyrosine kinase inhibitors, but the tumourigenic potential of EGFR mutations in breast cells and their potential for targeted therapy is unknown.

Materials and Methods

Constructs containing wild type, G719S or E746-A750 deletion mutant forms of EGFR were transfected into the MCF10A breast cells and their tumorigenic derivative, MCF10CA1a. The effects of EGFR over-expression and mutation on proliferation, migration, invasion, response to gefitinib, and tumour formation in vivo was investigated. Copy number analysis and whole exome sequencing of the MCF10A and MCF10CA1a cell lines were also performed.

Results

Mutant EGFR increased MCF10A and MCF10CA1a proliferation and MCF10A gefitinib sensitivity. The EGFR-E746-A750 deletion increased MCF10CA1a cell migration and invasion, and greatly increased MCF10CA1a xenograft tumour formation and growth. Compared to MCF10A cells, MCF10CA1a cells exhibited large regions of gain on chromosomes 3 and 9, deletion on chromosome 7, and mutations in many genes implicated in cancer.

Conclusions

Mutant EGFR enhances the oncogenic properties of MCF10A cell line, and increases sensitivity to gefitinib. Although the addition of EGFR E746-A750 renders the MCF10CA1a cells more tumourigenic in vivo it is not accompanied by increased gefitinib sensitivity, perhaps due to additional mutations, including the PIK3CA H1047R mutation, that the MCF10CA1a cell line has acquired. Screening TNBC/basal-like breast cancer for EGFR mutations may prove useful for directing therapy but, as in non-small cell lung cancer, accompanying mutations in PIK3CA may confer gefitinib resistance.     

Anticancer activities of (−)-epigallocatechin-3-gallate encapsulated nanoliposomes in MCF7 breast cancer cells

Abstract

The chemopreventive actions exerted by green tea are thought to be due to its major polyphenol, (?)-epigallocatechin-3-gallate (EGCG). However, the low level of stability and bioavailability in the body makes administering EGCG at chemopreventive doses unrealistic. We synthesized EGCG encapsulated chitosan-coated nanoliposomes (CSLIPO-EGCG), and observed their antiproliferative and proapoptotic effect in MCF7 breast cancer cells. CSLIPO-EGCG significantly enhanced EGCG stability, improved sustained release, increased intracellular EGCG content in MCF7 cells, induced apoptosis of MCF7 cells, and inhibited MCF7 cell proliferation compared to native EGCG and void CSLIPO. The CSLIPO-EGCG retained its antiproliferative and proapoptotic effectiveness at 10?μM or lower, at which native EGCG does not have any beneficial effects. This study portends a potential breakthrough in the prevention or even treatment of breast cancer by using biocompatible and biodegradable CSLIPO-EGCG with enhanced chemopreventive efficacy and minimized immunogenicity and side-effects.     

RUVBL1-ITFG1 interaction is required for collective invasion in breast cancer

BackgroundThe mechanisms of breast cancer collective invasion are poorly understood limiting the metastasis therapy. The ATPase RUVBL1 is frequently overexpressed in various cancers and plays a crucial role in oncogenic process. We further investigated the role of RUVBL1 in promoting collective invasion and uncovered that targeting RUVBL1 could inhibit metastatic progression.MethodsThe expression levels of RUVBL1 and ITFG1 were examined by Western blot and qRT-PCR. Co-localization and interaction of RUVBL1 and ITFG1 were determined by immunofluorescence and co-immunoprecipitation. The invasive ability was examined by transwell assay and microfluidic assay. The metastatic and tumorigenic abilities of breast cancer cells were revealed in BALB/c nude mice by xenograft and tail vein injection.ResultsATPase RUVBL1 is highly expressed in breast cancer and predicts the poor prognosis. Elevated expression of RUVBL1 is found in high metastatic breast cancer cells. Silencing RUVBL1 suppresses cancer cell expansion and invasion in vitro and in vivo. RUVBL1 interacts with a conserved transmembrane protein ITFG1 in cytoplasm and plasma membrane to promote the collective invasion. Using a microfluidic model, we demonstrated that silencing RUVBL1 or ITFG1 individually compromises collective invasion of breast cancer cells.ConclusionRUVBL1 is a vital regulator for collective invasion. The interaction between RUVBL1 and ITFG1 is required for breast cancer cell collective invasion and progression.General significanceTargeting collective invasion promoted by RUVBL1-ITFG1 complex provides a novel therapeutic strategy to improve the prognosis of invasive breast cancer.     

24R,25-Dihydroxyvitamin D3 regulates breast cancer cells in vitro and in vivo

BackgroundEpidemiological studies indicate high serum 25(OH)D₃ is associated with increased survival in breast cancer patients. Pre-clinical studies attributed this to anti-tumorigenic properties of its metabolite 1α,25(OH)₂D₃. However, 1α,25(OH)₂D₃ is highly calcemic and thus has a narrow therapeutic window. Here we propose another metabolite, 24R,25(OH)₂D₃, as an alternative non-calcemic vitamin D₃ supplement.MethodsNOD-SCID-IL2γR null female mice with MCF7 breast cancer xenografts in the mammary fat pad were treated with 24R,25(OH)₂D₃ and changes in tumor burden and metastases were assessed. ERα66+ MCF7 and T47D cells, and ERα66- HCC38 cells were treated with 24R,25(OH)₂D₃ in vitro to assess effects on proliferation and apoptosis. Effects on migration and metastatic markers were assessed in MCF7.Results24R,25(OH)₂D₃ reduced MCF7 tumor growth and metastasis in vivo. In vitro results indicate that this was not due to an anti-proliferative effect; 24R,25(OH)₂D₃ stimulated DNA synthesis in MCF7 and T47D. In contrast, markers of invasion and metastasis were decreased. 24R,25(OH)₂D₃ caused dose-dependent increases in apoptosis in MCF7 and T47D, but not HCC38 cells. Inhibitors to palmitoylation, caveolae integrity, phospholipase-D, and estrogen receptors (ER) demonstrate that 24R,25(OH)₂D₃ acts on MCF7 cells through caveolae-associated, phospholipase D-dependent mechanisms via cross-talk with ERs.ConclusionThese results indicate that 24R,25(OH)₂D₃ shows promise in treatment of breast cancer by stimulating tumor apoptosis and reducing metastasis.General significance24R,25(OH)₂D₃ regulates breast cancer cell survival through ER-associated mechanisms similar to 24R,25(OH)₂D₃ effects on chondrocytes. Thus, 24R,25(OH)₂D₃ may modulate cell survival in other estrogen-responsive cell types, and its therapeutic potential should be investigated in ER-associated pathologies.     

Screening active components of modified Xiaoyao powder as NRF2 agonists

Nuclear factor (erythroid‐derived 2)‐like 2 (NRF2) regulates antioxidant enzymes and phase II detoxifying enzymes, such as NAD(P)H: quinone oxidoreductase 1 (NQO1). Modified Xiaoyao powder (MXP) is most frequently used in the prevention and treatment of breast cancer in China. This study aimed to screen active components of MXP for antioxidant stress and chemoprevention, which depend on NRF2‐NQO1 signalling pathway. A total of 25 monomeric compounds contained in MXP were screened using an antioxidant response element–luciferase reporter. The most potent antioxidant response element–luciferase inducers were chosen to further examine their effects on NRF2 and NQO1 in MCF‐7 cells. These results were then confirmed by determining the oxidative stress levels and chemopreventive effect on inhibiting carcinogenesis transformation in NRF2 knockdown (NRF2^KD) and NRF2 wild‐type MCF‐10A cells. We found that quercetin, kaempferol, and atractylenolide II in MXP were potent NRF2 inducers, which could up‐regulate the expression of NRF2 and its downstream enzymes NQO1. In addition, these components could decrease reduced oxidative stress and inhibit carcinogenesis transformation, which depended on NRF2‐NQO1 pathway. In conclusion, NRF2‐NQO1 pathway plays an essential role in mediating the activity of MXP and its active components, at least in part; some beneficial effects of MXP may be applicable to breast cancer chemoprevention. Our study firstly found MXP active components including quercetin, kaempferol, and atractylenolide II. Our results firstly demonstrate that NRF2‐NQO1 pathway plays an essential role in mediating the activity of MXP and its active components in breast cancer chemoprevention. Our study firstly found that atractylenolide II is a novel NRF2 inducer.     

Different anticancer effects of Saxifragifolin A on estrogen receptor-positive and estrogen receptor-negative breast cancer cells

BackgroundBreast cancer is the leading cause of cancer-related death among women worldwide. For treating breast cancer, numerous natural products have been considered as chemotherapeutic drugs.Hypothesis/purposeThe present study aims to investigate the apoptotic effect of Saxifragifolin A (Saxi A) isolated from Androsace umbellata in two different human breast cancer cells which are ER-positive MCF-7 cells and ER-negative MDA-MB-231 cells, and examine the molecular basis for its anticancer actions.Study designThe inhibitory effects of Saxi A on cell survival were examined in MCF-7 cells and MDA-MB-231 cells in vitro.MethodsMTT assays, Annexin V/PI staining analysis, ROS production assay, Hoechst33342 staining and Western blot analysis were performed.ResultsOur results showed that MDA-MB-231 cells were more sensitive to Saxi A-induced apoptosis than MCF-7 cells. Saxi A induced apoptosis in MDA-MB-231 cells through ROS-mediated and caspase-dependent pathways, whereas treatment with Saxi A induced apoptosis in MCF-7 cells in a caspase-independent manner. In spite of Saxi A-induced activation of MAPKs in both breast cancer cell lines, only p38 MAPK and JNK mediated Saxi A-induced apoptosis. In addition, cell survival of shERα-transfected MCF-7 cells was decreased, while MDA-MB-231 cells that overexpress ERα remained viable.ConclusionSaxi A inhibits cell survival in MCF-7 cells and MDA-MB-231 cells through different regulatory pathway, and ERα status appears to be important for regulating Saxi A-induced apoptosis in breast cancer cells. Thus, Saxi A may have a potential therapeutic use for treating breast cancer.     

Aiduqing formula suppresses breast cancer metastasis via inhibiting CXCL1-mediated autophagy

BackgroundMetastasis is the most common lethal cause of breast cancer-related death. Recent studies have implied that autophagy is closely implicated in cancer metastasis. Therefore, it is of great significance to explore autophagy-related molecular targets involved in breast cancer metastasis and to develop therapeutic drugs.PurposeThis study was designed to investigate the anti-metastatic effects and autophagy regulatory mechanisms of Aiduqing (ADQ) formula on breast cancer.Study Design/MethodsMultiple cellular and molecular experiments were conducted to investigate the inhibitory effects of ADQ formula on autophagy and metastasis of breast cancer cells in vitro. Meanwhile, autophagic activator/inhibitor as well as CXCL1 overexpression or interference plasmids were used to investigate the underlying mechanisms of ADQ formula in modulating autophagy-mediated metastasis. Furthermore, the zebrafish xenotransplantation model and mouse xenografts were applied to validate the inhibitory effect of ADQ formula on autophagy-mediated metastasis in breast cancer in vivo.ResultsADQ formula significantly inhibited the proliferation, migration, invasion and autophagy but induced apoptosis of high-metastatic breast cancer cells in vitro. Similar results were also observed in starvation-induced breast cancer cells which exhibited elevated metastatic ability and autophagy activity. Mechanism investigations further approved that either CXCL1 overexpression or autophagic activator rapamycin can significantly abrogated the anti-metastatic effects of ADQ formula, suggesting that CXCL1-mediated autophagy may be the crucial pathway of ADQ formula in suppressing breast cancer metastasis. More importantly, ADQ formula suppressed breast cancer growth, autophagy, and metastasis in both the zebrafish xenotransplantation model and the mouse xenografts.ConclusionOur study not only revealed the novel function of CXCL1 in mediating autophagy-mediated metastasis but also suggested ADQ formula as a candidate drug for the treatment of metastatic breast cancer.