4-Hydroxytamoxifen-stimulated activation of ezrin is mediated via G-protein-coupled receptor 30 and promotes human breast cancer MCF-7 cell migration

AIM：To investigate the effect of 4-hydroxytamoxifen (OHT) on the migration of human breast cancer cell line MCF-7. METHODS：The cell migration ability was assayed by scratch healing experiment. The protein expression of Src, p-Src, ezrin and p-ezrin were examined by Western blotting. RESULTS：The results of scratch healing experiment confirmed that both OHT and estradiol (E2) promoted MCF-7 cell migration and the E2-enhanced the cells migration was not inhibited by OHT. The most effective concentration of OHT that enhanced cell migration was 5 μmol/L. Significant promotion of the cell migration was observed at 6 h after OHT treatment. Increased p-ezrin and p-Src expression was observed after treatment with OHT and G-protein-coupled receptor 30 (GPR30) agonists G1. The expression of p-ezrin after OHT treatment was inhibited by G15 (GPR30 blocker) or PP2（Src inhibitor）. CONCLUSION：4-Hydroxytamoxifen promotes MCF-7 cell migration by activation of ezrin via GPR30 and c-Src.     

Effect of hirsutine on hypoxia-induced migration and invasion abilities in human breast cancer MCF-7 cells

AIM: To investigate the effect of hirsutine on hypoxia-induced migration and invasion abilities of human breast cancer MCF-7 cells and its possible mechanism. METHODS: CCK-8 assay was employed to detect the cytotoxic effect of hirsutine on the MCF-7 cells. Cell migration was observed by wound healing assay, and cell invasion ability was measured by Transwell invasion assay. Western blot was used to analyze the protein levels of hypoxia-inducible factor-1α (HIF-1α), Snail, E-cadherin and matrix metalloproteinase-9 (MMP-9). The mRNA levels of HIF-1α was detected by RT-PCR. RESULTS: Hirsutine remarkably reduced the cell viability from 32 μmol/L (P<0.05), and the IC₅₀ value was 62.82 μmol/L. In hypoxia state, MCF-7 cells showed more powerful capabilities of migration and invasion (P<0.05), higher protein levels of HIF-1α, Snail and MMP-9 (P<0.05), lower protein level of E-cadherin (P<0.05), and higher mRNA level of HIF-1α (P<0.05). These hypoxia-induced effects were all inhibited by hirsutine at 16 μmol/L (P<0.05), apart from the mRNA level of HIF-1α. CONCLUSION: Hirsutine inhibits hypoxia-induced migration and invasion in human breast cancer MCF-7 cells most likely via down-regulation of the protein levels of HIF-1α, Snail and MMP-9, and up-regulation of the protein level of E-cadherin.     

Knockdown of RRM2 gene by siRNA inhibits human breast cancer cell proliferation,migration and tumor growth in nude mice

AIM: To explore the effect of ribonucleotide reductase M2 (RRM2) gene knockdown by siRNA on the proliferation and migration of human breast cancer MCF-7 cells and the tumor growth in BALB/c nude mice. METHODS: The mRNA and protein expression leves of RRM2 in human breast cancer cell line MCF-7 and human normal breast cell line MCF-10A were determined by real-time PCR and Western blotting. siRNA-RRM2 was constructed and transfected into MCF-7 cells at different time points and different concentrations. The silencing efficiency of RRM2 gene was detected by real-time PCR. The cell proliferation was measured by CCK-8 assay. The migration was observed using Transwell cell migration system. The effect of siRNA-RRM2 on the tumor growth was determined in nude mice. RESULTS: The mRNA and protein levels of RRM2 were higher in MCF-7 cells than those in MCF-10A cells. siRNA-RRM2 down-regulated the expression of RRM2 in MCF-7 cells in a time-and concentration-dependent manner. The results of CCK-8 assay showed that siRNA-RRM2 inhibited the proliferation ability of MCF-7 cells, but not that of MCF-10A cells. The results of Transwell assay indicated that siRNA-RRM2 inhibited the migration ability of MCF-7 cells. siRNA-RRM2 also inhibited the tumor growth in nude mice. CONCLUSION: RRM2 overexpression is associated with the breast cancer proliferation and migration. Suppression of RRM2 function is a potential therapeutic strategy for treating breast cancer.     

Chronic hypoxia enhances aggressiveness of MCF-7 breast cancer cells through EMT

AIM: To investigate the effects of chronic hypoxia on the aggressiveness of MCF-7, a human breast cancer cell line, and the underlying mechanisms.METHODS: MCF-7 cells were cultured under hypoxia (1% O₂, 5% CO₂ and 94% N₂) or control (95% O₂ and 5% CO₂) condition. The viability, proliferation, and invasion and migration abilities of the MCF-7 cells were determined by MTT assay, CCK-8 assay, cell counting, and cell invasion and migration assays. Anchorage-independent growth and the alteration of cellular polarization of the MCF-7 cells were tested by soft agar colony formation assay and Matrigel-3D culture assay, respectively. The effects of chronic hypoxia on the growth and metastasis of MCF-7 cells in vivo were investigated by xenograft in nude mice. The morphological changes of the MCF-7 cells were observed under an inverted microscope. Hypoxia-induced alterations in the levels of hypoxia inducible factor-1 (HIF-1) and phosphorylated glycogen synthase kinase-3β (p-GSK-3β) as well as epithelial-mesenchymal transition (EMT) molecules, such as E-cadherin, N-cadherin, vimentin, matrix metalloproteinase (MMP)-3 and MMP-9, were determined by Western blot.RESULTS: Chronic hypoxia significantly increased the viability, proliferation, and invasion and migration abilities of MCF-7 cells in vitro, enhanced the anchorage-independent growth, facilitated cellular polarization alteration in Matrigel-3D culture, and promoted cancer metastasis in vivo. Hypoxia up-regulated HIF-1, activated GSK-3β, down-regulated E-cadherin and increased the protein levels of N-cadherin, vimentin, MMP-3 and MMP-9. CONCLUSION: Chronic hypoxia enhances the aggressiveness of breast cancer cells probably through EMT.     

Effect of digoxin on hypoxia-induced epithelial-mesenchymal transition and invasion in human breast carcinoma MCF-7 cells

AIM: To investigate the effect of digoxin on hypoxia-induced epithelial-mesenchymal transition (EMT), migration and invasion in human breast carcinoma MCF-7 cells. METHODS: MCF-7 cells were treated in vitro with a chemical hypoxia inducer cobalt chloride (CoCl₂) to imitate hypoxia. Cell migration was observed by wound healing assay, and cell invasion was measured by Transwell invasion assay. The protein levels of hypoxia-inducible factor-1α (HIF-1α), Snail, E-cadherin and vimentin in MCF-7 cells were detected by Western blot. RESULTS: Digoxin inhibited CoCl₂-induced EMT and reversed the mesenchymal phenotype. CoCl₂ enhanced the abilities of migration and invasion (P<0.01), significantly decreased the expression of E-cadherin and increased the expression of HIF-1α, Snail and vimentin (P<0.01), but these effects were blocked by digoxin. CONCLUSION: Digoxin inhibits CoCl₂-induced EMT and invasion most likely via HIF1-α-Snail signaling pathway.     

Effects of furin inhibitor on metastasis of human breast cancer MCF-7 cells

AIM：To investigate the mechanism underlying breast cancer metastasis and to provide theoretical data for studying the pathogenesis of breast cancer onset and development. METHODS：Human breast cancer MCF-7 cells were treated with different concentrations of furin inhibitor α1-PDX for 48 h. Wound healing assay and Transwell assay were applied to detect the migration and invasion abilities of the MCF-7 cells. The expression of cell migration-associated proteins, including membrane-type 1 matrix metalloproteinase (MT1-MMP), vascular endothelial growth factor (VEGF)-C and VEGF-D, was determined by Western blotting. The protein levels of MMP2 and MMP9 in the supernatant were measured by ELISA. RESULTS：Compared with control group, 200 nmol/L of furin inhibitor exerted significant inhibitory effects on the cell migration (P<0.05). The expression of cell migration-associated proteins MT1-MMP, VEGF-C and VEGF-D was significantly inhibited after treated with α1-PDX (P<0.05). Significant inhibitory effects of α1-PDX on the expression of MMP9 and MMP2 (P<0.05) in the supernatant were observed. CONCLUSION：Furin inhibitor suppresses the metastasis of MCF-7 cells via down-regulating the expression of MMPs and VEGFs.     

Effects of propofol on expression of CXCR4/CXCR7 and migration ability of human breast cancer MCF-7 cells in vitro

AIM:To investigate the effects of propofol on the expression of CXC-chemokine receptor (CXCR)4/CXCR7 and migration ability of human breast cancer MCF-7 cells in vitro. METHODS:MCF-7 cells were randomly divided into 4 groups,control group, lipid emulsion group, 3 mg/L and 8 mg/L propofol group. The cell viability was measured by MTT assay. The migration ability was detected by wound-healing assay and Transwell assay. The mRNA level of CXCR4/CXCR7 was detected by RT-qPCR. The protein expression leve of CXCR4/CXCR7 was determined by Western blot. RESULTS:Compared with control group, the scratching healing rates in 3 and 8 mg/L propofol group were decreased (P<0.05), and the chemotactic index was also decreased (P<0.05). The protein expression level of CXCR4/CXCR7 was decreased in 3 and 8 mg/L propofol group(P<0.05). However, both the mRNA level of CXCR4/CXCR7 and the viability of the MCF-7 cells kept no change. CONCLUSION:Propofol down-regulates the protein expression of CXCR4/CXCR7 and inhibits the migration ability of breast cancer MCF-7 cells in vitro.     

Expression of CUG-binding protein 1 in breast cancer and its effect on cell viability and invasion ability

AIM: To investigate the expression of CUG-binding protein 1 (CUGBP1) in breast cancer tissues, and to explore the effect of CUGBP1 gene silencing on the viability and invasion ability of human breast cancer MCF-7 cells. METHODS: A total of 96 cases of patients with breast cancer undergoing surgical treatment were selected in the Second Affiliated Hospital of Zhengzhou University from March 2015 to September 2017. Immunohistochemical staining was used to detect the protein expression of CUGBP1 in the breast cancer and adjacent tissues. MCF-7 cells were cultured and divided into CUGBP1 interference sequence group, control sequence group and blank group. Western blot was used to detect the protein expression of CUGBP1, Twist, E-cadherin and vimentin in the cells. The cell viability was measured by MTT assay. The cell invasion ability was detected by Transwell assay. RESULTS: The positive expression rate of CUGBP1 protein in the breast cancer tissues was higher than that in the adjacent tissues (χ²=28.900, P<0.001). The differences of CUGBP1 protein expression in the breast cancer tissues among TNM staging, histological grading and lymph node metastasis were statistically significant (P<0.05). The relative protein expression levels of CUGBP1, Twist and vimentin in CUGBP1 interference sequence group were lower than those in control sequence group and blank group, while the relative protein expression of E-cadherin was higher than that in control sequence group and blank group (P<0.05). The cell viability at 24 h, 48 h, 72 h and 96 h in CUGBP1 interference sequence group was lower than that in control sequence group and blank group (〖P<0.05). The invasive cells in CUGBP1 interference sequence group were less than those in control sequence group and blank group (P<0.05). CONCLUSION: CUGBP1 protein is highly expressed in the breast cancer tissues. Specific silencing of 〖STBX〗CUGBP1〖STBZ〗 gene expression in breast cancer MCF-7 cells effectively inhibits the cell viability and invasiveness, and its mechanism may be related to inhibiting the process of epithelial-mesenchymal transition.     

Mechanism of AKT1 negatively regulating breast cancer cell migration

AIM: To investigate the molecular mechanism and downstream signaling pathway by which AKT1 inhibition regulates breast cancer cell migration. METHODS: RNA interference was used to knockdown the expression of AKT1. Western blot assay was performed to examine the expression of AKT1 total protein, β-catenin total protein and β-catenin nuclear protein. Immunofluorescence was used to examine the cellular localization of β-catenin. Transwell assay was used to investigate whether β-catenin nuclear accumulation as an alternative pathway was responsible for breast cancer metastasis induced by AKT1 inhibition. RESULTS: The total protein expression of AKT1 was decreased in MCF-7 and MDA-MB-231 cells treated with AKT1 siRNA. A significant increase in the protein expression of β-catenin was observed in MCF-7 cells and MDA-MB-231 cells treated with AKT1 siRNA. Immunofluorescence staining showed that MCF-7 cells and MDA-MB-231 cells displayed strong β-catenin staining in the cytoplasm and nucleus after knockdown of AKT1 expression. The ability of tumor cell migration increased dramatically after treated with AKT1 specific siRNA in the breast cancer MCF-7 cells and MDA-MB-231 cells in Transwell assay. XAV-939 reversed breast cancer cell migration induced by knockdown of AKT1 expression. CONCLUSION: β-catenin nuclear accumulation contributes to AKT1 inhibition-mediated breast cancer cell migration.     

Effects of DSF/Cu on surface ultrastructures and mechanical properties of human breast cancer and normal breast epithelial cells

AIM: To study the effects of disulfiram/copper complex (DSF/Cu) on ultrastructures and mechanical properties of human breast cancer and normal breast epithelial cells by atomic force microscopy (AFM) based on the nanoscale resolution and piconewton force measurement level. METHODS: The change of cell cycle and apoptotic rate of MCF-7 cells and MCF-10A cells induced by DSF/Cu were compared by flow cytometry. The cell surface morphology, ultrastructure, height, width and roughness were detected by AFM. The effects of DSF/Cu on the hardness (Young's modulus) of the 2 kinds of cells were determined by AFM with indentation technique. RESULTS: DSF/Cu significantly induced apoptosis of the MCF-7 cells in a dose-dependent manner, whereas had little effect on the MCF-10A cells. The cell cycle analysis showed that DSF/Cu induced G₂/M arrest in the MCF-7 cells, but led to G₀/G₁ arrest in the MCF-10A cells. The AFM images showed that the MCF-7 cells shrank and showed smaller and smoother morphology, and the filopodia were retracted obviously, even some became into lamellipodia, or disappeared completely after treated with DSF/Cu at concentrations of 400 and 800 nmol/L. The quantitative analysis indicated that the MCF-7 cells showed smaller width and larger height, and the root mean square roughness and average roughness were decreased significantly in a dose-dependent manner after treated with DSF/Cu at concentrations of 400 and 800 nmol/L. However, little effect in the MCF-10A cells was observed. The biomechanics test at a single cell level demonstrated that the Young's modulus of the MCF-7 cells and MCF-10A cells were both increased, yet the proportion increased in the MCF-7 cells was much higher than that in the MCF-10A cells after treated with DSF/Cu at concentrations of 400 and 800 nmol/L. CONCLUSION: DSF/Cu has strong antitumor effect on breast cancer with high efficiency and low toxicity by changing the properties of the biomechanics specifically.     

Reverse effect of FOXC2 silencing on epithelial-mesenchymal transition induced by TGF-β1 in MCF-7 cells

AIM: To study the reverse effect of FOXC2 silencing on epithelial-mesenchymal transition (EMT) induced by transforming growth factor β1(TGF-β1) in MCF-7 cells. METHODS: Cultured MCF-7 cells were treated with TGF-β1 at concentration of 5 μg/L for 6 d. The cell morphological changes were observed under phase-contrast microscope. The changes of EMT-related marker proteins were assessed by immunofluorescence staining assay. TGF-β1-induced MCF-7 cells were transfected with FOXC2-siRNA mediated by recombinant lentivirus. In addition, the expression levels of FOXC2 and EMT-related marker proteins E-cadherin, claudin-1 and fibronectin-1 were also measured by RT-PCR and Western blotting. The invasion of MCF-7 cells was detected by Transwell assay. RESULTS: TGF-β1 induced the morphological alteration in MCF-7 cells from epithelial phenotype to mesenchymal phenotype,up-regulated the expression of mesenchymal marker fibronectin-1, and down-regulated the expression of epithelial markers E-cadherin and claudin-1. FOXC2 silencing reversed and restored the mesenchymal MCF-7 cells to epithelial phenotype and reduced the tumor invasion. CONCLUSION: EMT model induced by TGF-β1 in breast cancer MCF-7 cells is successfully established, which increases the invasion of MCF-7 cells. The effect of TGF-β1 is reversed by FOXC2-siRNA and the invasion of the cells is reduced.     

Effects of heterogously-expressed RON receptor tyrosine kinase on motile/invasive ability of human colorectal cancer cell line RKO

AIM: To investigate the roles of overexpression of RON receptor tyrosine kinase in motile/invasive ability of human colorectal cancer cell line RKO. METHODS: A eucaryotic expression vector pDR2 containing full-length wt-RON cDNA was transfected into the colorectal cancer cell line RKO and a stable expression clone was obtained. The motile/invasive ability was tested by wound healing test and the transwell migration assay. The expression of E-cadherin was measured by Western blotting. RESULTS: Motile ability of transfected RKO was greatly promoted by transwell chemotaxis assay (P<0.01). The wound healing time showed statistical difference as of (42.50±4.12) h, (69.50±2.52) h and (70.50±3.42) h, respectively in transfected group, untransfected group and vector control group. After knocking down RON by siRNA, the motile became less than that in control group (P<0.01). E-cadherin expression in transfected RKO was decreased significantly due to pDR2-wt-RON transfection. CONCLUSIONS: Overexpression of wt-RON led to the decrease in expression of E-cadherin and decreased cancer cell-cell adhension. At the same time, migration/invasion ability was promoted. Taken together, abnormal accumulation of RON might play potential roles in invasion/metastasis of colorectal cancer. RNAi can block motile/invasion ability mediated by RON.     

Effects of the grub extract on apoptosis of MCF-7 human breast cancer cell line

AIM: To investigate the apoptotic pathway of MCF-7 breast cancer induced by the grub extract in vitro.METHODS: MTT assay was used to determine the effect of the grub extract on proliferation of MCF-7 human breast cancer cell line and cell toxicity. Morphological changes of the apoptosis in cancer cells were observed by HE staining through invert microscope, light microscope, AO/EB double fluorescent staining under fluorescent microscope. FCM was used to assay the change of apoptotic rate. The expression of Bcl-2, Fas, caspase-9, caspase-3 in apoptotic pathway was detected with immunocytochemical method before and after exposure to the grub extract, and the effect of that on apoptotic pathway was explored.RESULTS: (1) The MTT test showed that the growth of MCF-7 human breast cancer cell line was significantly inhibited by the grub extract in dose and time dependent manners. The inhibitory rate in exposure group was significantly different from that in control group (P<0.01). (2) Morphological changes of apoptosis including nuclear condensation, fragment and apoptosis body formation were observed by invert microscope. (3) The MCF-7 human breast cancer cells in experimental group by HE staining showed nuclear condensation and blue-black, cytoplasm slight red, nuclear chromatin condensation and fragment shape, apoptosis body formations. (4) Apoptosis in the experimental group was observed by AO/EB double fluorescent staining under fluorescent microscope. (5) FCM assay indicated that apoptotic rate increased significantly in time dependent manner in experimental group. (6) The expression of Bcl-2 was down-regulated, while that of Fas, caspase-3, caspase-9 was up-regulated, compared with control group (P<0.01).CONCLUSION: (1) The proliferation of MCF-7 human breast cancer cell line can be inhibited significantly by the grub extract in vitro. (2)The mechanism of effect of the grub extract on MCF-7 human breast cancer cell line might be mediated by down-regulation of Bcl-2 and up-regulation of Fas, caspase-3, caspase-9. This type of apoptosis starting and performing is through death receptor pathway and mitochondrial pathway.     

β-estradiol promotes invasion and migration of lung cancer A549 cells via ERβ-mediated ERK1/2 membrane-initiated steroid signaling

AIM: To investigate the regulatory mechanism of β-estradiol in the invasion and migration of lung cancer A549 cells. METHODS: Breast cancer MCF-7 cells and lung cancer A549 cells were cultured in vitro. The MCF-7 cells were used as the estrogen receptor (ER) positive expression cell model. Real-time PCR and immunofluorescence were employed to measure the expression level and the localization of ER in A549 cells. The phosphorylation of ERK1/2 upon β-estradiol stimulation was quantified by Western blot. The invasion and migration abilities of A549 cells upon β-estradiol stimulation with or without ERK1/2 inhibitor PD98059 were measured by Transwell and Cell-IQ assays. RESULTS: ERβ was the dominant ER subtype in the A549 cells and primarily comprised of ERβ2 and ERβ5. Immunofluorescence revealed that ERβ expression was mainly localized in the cytoplasm. β-estradiol induced phosphorylation of ERK1/2 and promoted the invasion and migration of the cells. Inhibition of ERK1/2 signaling reversed β-estradiol-promoted invasion and migration of A549 cells. CONCLUSION: ERβ-mediated membrane-initiated steroid signaling is involved in the process of β-estradiol-promoted invasion and migration of A549 cells, through which ERK1/2 signaling plays a pivotal role.     

Effect of HC-1119 on biological behaviors of triple-negative breast cancer BT549 cells

AIM: To explore the effect of new artificially synthesized androgen receptor (AR) antagonist HC-1119 on the biological function of triple-negative breast cancer (TNBC) BT549 cells and the molecular mechanism. METHODS: The AR expression was assessed in different human breast cancer cell lines MDA-MB-231, T47D, MCF-7, SKBR3 and BT549 by Western blot. The TNBC BT549 cells with AR positive expression were treated with HC-1119. The cell viability was measured by CCK-8 assay. The apoptosis rate and cell cycle distribution were analyzed by flow cytometry. The migration and invasion abilities were detected by Transwell assay in vitro. The protein expression of E-cadherin, vimentin and P21 was determined by Western blot. RESULTS: AR was positively expressed in BT549 cells. HC-1119 inhibited the cell viability in a time-and dose-dependent manner (P<0.05), increased the percentage of apoptotic cells and the percentage of S-phase cells significantly, repressed the migration and invasion abilities (P<0.05), and decreased P21 expression at protein level (P<0.01). No influence on the expression of E-cadherin and vimentin in the BT549 cells was observed. CONCLUSION: AR antagonist HC-1119 decreases the viability, migration ability and invasion ability, enhances the apoptosis, and arrests the cell cycle distribution of TNBC BT549 cells. HC-1119 represses the viability of BT549 cells by down-regulating P21 expression, while the process of epithelial-mesenchymal transition is not involved in the inhibition of cell migration.     

Effect of HMGB1 expression knockdown on invasion ability of breast cancer cells induced by TNF-α

AIM:To investigate the effect of high-mobility group box-1 (HMGB1) expression knockdown on the invasion ability of breast cancer cells induced by tumor necrosis factor-α (TNF-α). METHODS:HMGB1 siRNA was used to transfect into the breast cancer MDA-MB-231 cells. The expression of HMGB1 at mRNA and protein levels was determined by RT-qPCR and Western blot. After the MDA-MB-231 cells with HMGB1 expression knockdown were treated with TNF-α, the apoptosis rate was analyzed by flow cytometry, the cell invasion ability was measured by Transwell assay, and the cell migration ability was detected by cell scratch test. The protein expression of E-cadherin, MMP-2, N-cadherin, MMP-9 and Bax was determined by Western blot. RESULTS:The expression of HMGB1 at mRNA and protein levels in the MDA-MB-231 cells transfected with HMGB1 siRNA was significantly lower than that in the non-transfected cells (P<0.05). The apoptosis rate in the cells was increased after TNF-α treatment, and the cell invasion and migration abilities were also increased. The protein level of E-cadherin in the cells was decreased, the protein level of N-cadherin was increased, and the protein levels of MMP-2, MMP-9 and Bax were also increased (P<0.05). After the MDA-MB-231 cells with HMGB1 expression knockdown were induced by TNF-α, the apoptotic rate was increased, the invasion and migration abilities were decreased, the protein levels of E-cadherin and Bax were increased, and the protein levels of N-cadherin, MMP-2 and MMP-9 were decreased, as compared with the cells only induced by TNF-α without knockdown of HMGB1 expression (P<0.05). CONCLUSION:Knockdown of HMGB1 expression enhances the apoptosis of breast cancer cells induced by TNF-α, and inhibited the cell invasion, migration and epithelial-mesenchymal transition induced by TNF-α. The mechanism may be related with the changes of protein expression of MMP-2, MMP-9 and Bax.     

Effect of berberine on invasion and migration of PG cells from a high metastatic human giant lung carcinoma cell line

AIM:To study the effect of berberine(Ber) on invasion and migration of PG cells from a high metastatic human giant lung carcinoma cell line and to explore its mechanism. METHODS:Agarose drop method was used to detect PG migration; transwell cabin with FN in lower chamber was adopted to detect PG chemotaxis. PG adhesion to FN and martrigel was detected by MTT; PG invasive ability was determined by transwell cabin covered with martrigel. Expression of MMP2/TIMP2 protein and mRNA were detected by quantitative immunocytochemical method and RT-PCR respectively. RESULTS:After PG was treated by Ber（10 mg/L） for 24 h: 1) migration distance of Ber-treated PG cells was markedly shorter than that of control cells (P<0.01) and the number of passed membrane cells towards FN was much fewer than that of control cells (P<0.01); 2) PG adhesion to FN and martrigel was inhibited remarkably by Ber compared with control PG; 3) the migration of PG cells through the martrigel-coated transwell was significantly inhibited by the addition of Ber; 4) MMP2 expression was reduced significantly(P<0.01), while the TIMP2 expression showed up-regulating tendency, but had no differences compared with control group(P>0.05). The MMP2/TIMP2 ratio was decreased; 5) the MMP2 mRNA/TIMP2 mRNA ratio was decreased by Ber.CONCLUSION:Inhibition of cell migration, adhesion to ECM and invasion into ECM of tumor cells and regulation of homeostasis between MMPs and TIMPs to maintain ECM integrity may be the basic mechanism of inhibitive effect of Ber on invasion and metastasis of tumors.     

Effects of WNT5B over-expression on viability and apoptosis of human breast cancer cell line MCF-7

AIM: To detect the expression of WNT5B in normal breast epithelial cells and different breast cancer cell lines, and to investigate the effects of WNT5B over-expression on the viability and apoptosis of human breast cell line MCF-7.METHODS: The mRNA expression of WNT5B was detected by RT-PCR in different breast cancer cells. MCF-7 cells were transfected with plasmid pcDNA3.1/WNT5B or pcDNA3.1, and the expression of WNT5B at mRNA and protein levels was examined in the 2 groups by real-time PCR and Western blotting, respectively. Subsequently, the changes of cell viability and cell apoptosis were analyzed by CCK-8 assay and flow cytometry, respectively. RESULTS: The expression of WNT5B in the breast cancer cell lines was lower than that in MCF10A cells. The WNT5B expression in the MCF-7 cells in experimental group was significantly higher than that in vector group (P<0.05). However, the cell viability in experimental group decreased significantly as compared with vector group (P<0.05). The number of the cells in S-phase obviously increased, while the percentage of the cells in G₁-phase and G₂/M-phase decreased compared with vector group. The number of apoptotic cells in WNT5B group was significantly higher than that in vector group.CONCLUSION: The expression of WNT5B is decreased in breast cancer cells. WNT5B over-expression significantly inhibits the cell growth and promotes the cell apoptosis in breast cancer MCF7 cells.     

Effects of artemisunate on anoikis resistance in human breast cancer cell MCF-7

AIM: To study the effects of artemisunate on anoikis resistance in human breast cancer cells. METHODS: After breast cancer MCF-7 cells were treated with artemisunate, the growth of anchorage independence of breast cancer MCF-7 cells was examined in soft agar colony formation, and apoptosis of breast cancer were evaluated by terminal deoxynucleatidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and DNA ladder. RESULTS: Artemisunate significantly inhibited the growth of anchorage independence of breast cancer MCF-7 cells in soft agar colon formation in a dose-dependent manner. Artemisunate induced apoptosis in breast cancer cells was conformed by DNA ladder and TUNEL assay, which was in a time-and dose-dependent manner. CONCLUSION: Artemisunate inhibits the growth of anchorage independence of breast cancer MCF-7 cells, which is related to anoikis.