Metformin inhibits proliferation and promotes apoptosis of HER-2 positive breast cancer cells possibly through the Hippo-YAP pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effect of metformin on the proliferation and apoptosis of HER-2-positive breast cancer cell line SKBR3 and explore the possible mechanism of its action.@*METHODS@#SKBR3 cells were treated with different concentrations (20-120 μmol/L) of metformin, and the changes in cell proliferation and colony formation ability were assessed using CCK-8 assay and crystal violet staining, respectively. Flow cytometry was performed to analyze cell apoptosis and cell cycle changes. Real-time fluorescent quantitative PCR (qRT-PCR) was used to detect mRNA expressions of YAP, TAZ, EGFR, CTGF, CYR61, E-cadherin, N-cadherin, vimentin and fibronectin in the treated cells, and the protein expressions of YAP and TAZ were detected using Western blotting; immunofluorescence assay was used to observe YAP/TAZ nuclear translocation in the cells.@*RESULTS@#Metformin treatment significantly inhibited the proliferation of SKBR3 cells (P < 0.05) in a concentration- and time-dependent manner. The results of flow cytometry showed that metformin significantly promoted apoptosis and caused cell cycle arrest at G1 phase in SKBR3 cells. Metformin treatment significantly down-regulated the mRNA expressions of YAP, TAZ, EGFR, CTGF and CYR61, N-cadherin, vimentin and fibronectin (P < 0.05) and up-regulated the expression of E-cadherin (P < 0.05); Western blotting results showed that YAP and TAZ protein expressions were significantly down-regulated in the cells after metformin treatment (P < 0.05). Immunofluorescence assay revealed that metformin treatment caused the concentration of YAP and TAZ in the cytoplasm, and significantly reduced their amount in the cell nucleus.@*CONCLUSION@#Metformin can inhibit proliferation and promote apoptosis and epithelal-mesenchymal transition of HER-2 positive breast cancer cells possibly by that inhibing YAP and TAZ expression and their nuclear localization.

Essential oil composition and cytotoxic activity in twospecies ofthe plant genus Vismia (Hypericaceae) from the Venezuelan Andes / Composición de aceites esenciales y actividad citotóxica en dos especies de plantas del género Vismia (Hypericaceae) de los Andes venezolanos

Introduction: The Vismia genus belongs to the Hypericaceae family and comprises around 57 species of which 17 have been located in Venezuela. Previous investigations have been carried out in extracts as well as pure isolated compounds, revealing antimicrobial, antioxidant and anti-HIV, among other, biological activities. Objective: This investigation aims to determine the cytotoxic activity of essential oils from leaves of Vismia baccifera Triana & Planch (VBJ and VBV) and Vismia macrophylla Kunth (VM) collected in three different locations of the Venezuelan Andean region. Methods: Essential oils obtained by hydrodistillation were analyzed using gas chromatography-mass spectrometry (GC-MS) and their cytotoxic activity was analyzed following the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Human tumor cell lines from SKBr3, MCF-7 and PANC-1, two breast carcinomas and one pancreatic adenocarcinoma of ductal type, were tested with the oil samples and human dermis fibroblasts were used as non-tumor cells. Results: β-caryophyllene and trans-caryophyllene were present as major components in VBJ and VBV, respectively, while γ-bisabolene was the main component in the VM sample. Anticancer activity was observed on V. baccifera essential oil against SKBr3, MCF-7 and PANC-1. The selectivity index showed that VBV is highly selective against the SKBr3 cell line and has no activity against non-tumor cells. Conclusions: These results are considered a contribution to natural products research and may provide supportive data for future studies on cancer.

Introducción: El género Vismia pertenece a la familia Hypericaceae y comprende alrededor de 57 especies de las cuales 17 han sido ubicadas en Venezuela. Se han realizado investigaciones previas tanto en extractos como en compuestos puros aislados revelando actividad antimicrobiana, antioxidante y anti-VIH, entre otras actividades biológicas. Objetivo: El propósito de esta investigación es determinar la actividad citotóxica de los aceites esenciales de las hojas de Vismia baccifera Triana & Planch (VBJ y VBV) y Vismia macrophylla Kunth (VM) recolectadas en tres localidades de la región andina venezolana. Métodos: Aceites esenciales obtenidos por hidrodestilación fueron analizados por cromatografía de gases-espectrometría de masas y su actividad citotóxica fue analizada siguiendo el método MTT (bromuro de 3-[4,5-dimetiltiazol-2-il]-2,5-difeniltetrazolio). Los aceites esenciales fueron ensayados frente a células tumorales humanas SKBr3, MCF-7 y PANC-1, dos carcinomas de mama y un adenocarcinoma pancreático del tipo ductal, usando cultivos primarios de fibroblastos de dermis humana como células no tumorales. Resultados: β-cariofileno y trans-cariofileno estuvieron presentes como compuestos mayoritarios en VBJ y VBV, respectivamente, mientras que γ-bisaboleno fue el componente principal en la muestra VM. El aceite esencial de V. baccifera mostró actividad anticancerígena frente a SKBr3, MCF-7 y PANC-1. El índice de selectividad reveló que VBV es altamente selectivo frente a la línea celular SKBr3 y no presenta actividad contra las células no tumorales. Conclusiones: Estos resultados se consideran una contribución a la investigación de los productos naturales y los datos pueden ser de utilidad en futuras investigaciones sobre el cáncer.

Lapatinib-loaded nanocolloidal polymeric micelles for the efficient treatment of breast cancer

This study aims at preparing and evaluating lapatinib-loaded polymeric micelles for the better treatment of breastcancer (BC). LP-loaded polymeric micelles (LP-PMs) were prepared as per our previous studies by using Soluplus®as the polymer. Therefore, we employed the lyophilization technique using mannitol as a cryoprotectant and furtherconducted in vitro and in vivo anticancer efficacy studies, in addition to our previously reported works. We found thatthe lyophilized LP-PMs were sufficiently stable and retained encapsulated drugs. Furthermore, their smooth surfacewas visualized on the atomic force microscopy. The X-ray powder diffractogram of LP-PMs showed successfulencapsulation of Lapatinib; however, the presence of few drug molecules on the surface was evidenced by energydispersive X-ray analysis. Furthermore, LP-PMs showed sustained release of drugs, with selective drug release in anacidic environment, resembling that of a tumor. The LP-PMs exhibited higher cytotoxicity against SKBr3 BC cellsand also induced effective inhibition of the growth of the tumor in vivo when compared to that of lapatinib solutionand marketed formulation. The results of this study indicate the greater potential of LP-PMs for the efficient treatmentfor BC

lncRNA HOTAIR promotes malignant biological behaviors of breast cancer SKBR3 cells through miR-519d-3p/CCND1 axis / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To explore the effect of lncRNA HOTAIR/miR-519d-3p/cyclin D1 (CCND1) axis on the proliferation and metastasis of breast cancer cells and its underlying mechanism. Methods: A total of 50 pairs of breast cancer tissues and corresponding para-cancer tissues resected from breast cancer patients in the Department of Breast Surgery, the Third Hospital of Nanchang from March 2017 to February 2019 were collected for this study. The expression level of HOTAIR in breast cancer tissues and paired paracancer tissues was detected by qPCR, in addition, the expressions of HOTAIR and miR-519d-3p in normal breast epithelial cells and breast cancer cell lines were also detected. Breast cancer SKBR3 cells were divided into NC group (without any treatment), si-HOTAIR group, mir-519d-3p mimics group, miR-519d-3p mimic+pcHOTAIR group, miR-519d-3p mimic+pcCCND1 group, and si-HOTAIR+ pcCCND1 group. The proliferation ability of SKBR3 cells was detected by CCK-8. Invasion and migration of SKBR3 cells were detected by Transwell. The expression levels of E-cadherin, N-cadherin, Vimentin and CCND1 in SKBR3 cells were detected by Western blotting. The targeting relationship between HOTAIR and miR-519d-3p, miR-519d-3p and CCND1 was detected by Dualluciferase reporter gene system. Results: HOTAIR was highly expressed in breast cancer tissues and cell lines, with the highest expression in SKBR3 cells. HOTAIR knockdown significantly inhibited the proliferation, invasion and migration of SKBR3 cells, as well as increased the expression level of E-cadherin and decreased the expression levels of N-cadherin and Vimentin. Dual-luciferase reporter gene assay showed that HOTAIR targetedly down-regulated the expression of miR-519d-3p, and miR-519d-3p targetedly downregulated the expression of CCND1. Further studies showed that knockout of HOTAIR inhibited the EMT, proliferation, invasion and migration of SKBR3 cells through enhancing the inhibitory effect of miR-519d-3p on CCND1 expression (all P<0.05). Conclusion: HOTAIR knockdown inhibits proliferation and metastasis of SKBR3 cells by regulating the axis of miR-519d-3p/CCND1.

Molecular mechanism of apoptosis of breast cancer SKBR-3 cells induced by cryptanshinone via G protein coupled estrogen receptor( GPER) mediated pathway / 中国中药杂志

The study aimed to illuminate the role of G protein coupled estrogen receptor( GPER) and its mediated PI3 K/AKT signaling pathway in cryptotanshinone( CPT) induced apoptosis of breast cancer SKBR-3 cells,which is GPER positive and ER negative.The apoptosis rate of SKBR-3 cells was tested by Annexin V-FITC/PI staining and apoptosis effector caspase-3 was determined by Western blot. The key proteins in PI3 K/AKT signaling pathway mediated by GPER were detected by Western blot and immunofluorescence technique. Meanwhile,the agonist G1 and antagonist G15 of GPER and antagonist LY294002 of PI3 K were employed in the test to further clarify the effect of GPER and PI3 K/AKT pathway. The results indicated that the apoptosis rate was increased from 4. 7% to46. 1% and 69. 0% after treatment with 0,5,10 μmol·L~(-1) CPT for 48 h( P<0. 01). The expression of PI3 K,AKT and p-AKT were inhibited( P<0. 05 or P<0. 01),while caspase-3 level increased obviously after treatment with CPT( P<0. 01). Importantly,inhibitory effect of PI3 K/AKT signaling pathway by CPT was further enhanced by G1 and attenuated by G15. LY294002 also induced a further inhibition of expression of AKT and p-AKT. The mean fluorescence intensity of AKT and p-AKT could be decreased by CPT. Furthermore,CPT could downregulate GPER expression in SKBR-3 cells( P<0. 01),which could be inhibited by G1 and enhanced by G15.In conclusion,CPT could induce the apoptosis of ER negative and GPER positive breast cancer SKBR-3 cells and the molecular mechanism is related to its regulatory effect of GPER and its mediated PI3 K/AKT signaling pathway.

Inhibitory effect of curcumin on human breast cancer cell line SKBR3 and its mechanism / 中国生化药物杂志

Objective To observe the effect of curcumin on proliferation, apoptosis, Caspase-3 activity and telomerase activity of chronic granulocytic breast cancer SKBR3 cell line, and to investigate the mechanism of curcumin. Methods The cell growth curve was drawn by MTT;the apoptotic cells were detected by Annexin, V and PI double staining; the expression of Caspase-3 was detected by Westernblot; the activity of telomerase was detected by TRAP-PCR silver staining. Results Curcumin could significantly inhibit the proliferation of SKBR3 cells in a time and concentration dependent, has a certain effect on reducing the telomerase activity of SKBR3 cells can enhance the expression of Caspase-3 induced apoptosis. Conclusion Curcumin can effectively inhibit the proliferation of SKBR3 cells, increase the synthesis of Caspase-3 protein, inhibit the activity of telomerase and mediate the apoptosis of SKBR3 cells.

Inhibitory effect of curcumin on human breast cancer cell line SKBR3 and its mechanism / 中国生化药物杂志

Objective To observe the effect of curcumin on proliferation, apoptosis, Caspase-3 activity and telomerase activity of chronic granulocytic breast cancer SKBR3 cell line, and to investigate the mechanism of curcumin. Methods The cell growth curve was drawn by MTT;the apoptotic cells were detected by Annexin, V and PI double staining; the expression of Caspase-3 was detected by Westernblot; the activity of telomerase was detected by TRAP-PCR silver staining. Results Curcumin could significantly inhibit the proliferation of SKBR3 cells in a time and concentration dependent, has a certain effect on reducing the telomerase activity of SKBR3 cells can enhance the expression of Caspase-3 induced apoptosis. Conclusion Curcumin can effectively inhibit the proliferation of SKBR3 cells, increase the synthesis of Caspase-3 protein, inhibit the activity of telomerase and mediate the apoptosis of SKBR3 cells.

Effects of anti-HER-2 chimeric antibody chA21 on proliferation and apoptosis of SKBR3 cells / 中国药理学通报

Aim To explore the effects of anti-HER-2 chimeric antibody chA 21 on proliferation and apoptosis of SKBR3 cells.Methods MTT colorometric assay,HE staining,transmission electron microscopy,flow cytometry,and TUNEL were used to study the proliferation inhibition and apoptosis induction of SKBR3 cells by chA 21 in vitro.Results Proliferative inhibition rates and apoptotic index of SKBR3 cells were increased in a dose and time dependent manner after exposure to chA21(0.2～5.4 mg?L~(-1)).Conclusion chA 21 could remarkably inhibit proliferation of SKBR3 cells in vitro and apoptosis induction may be one of its main mechanisms.

Anti-proliferation role and effect on PI3K/Akt and Erk1/2 signal pathways of a chimeric anti-erbB2 antibody(chA21)on SKBR3 cells / 中国药理学通报

Aim To study the inhibitory effect of anti-ErbB2 chimeric antibody chA21 on proliferation of human malignant breast cancer cell lines SKBR3 and explore its possible mechanisms through studying its effects on ErbB2 distribution and PI3K/Akt,Erk1/2 signal transduction.Methods The inhibitory effect of chA21 on SKBR3 was assessed by MTT assay.The effect of chA21 on distribution of ErbB2 on cell plasma membrane was determined by FACS(Fluorescence-activated cell sorting)analysis;p-Akt and p-Erk1/2 were detected by Western blot.Results The inhibitory rate of chA21 on SKBR3 cells in vitro increased in a dose and time dependent manner.Furthermore,it could down-regulate the distribution of ErbB2 on plasma membrane and decrease the activation of p-Akt and p-Erk1/2.Conclusions ChA21 can inhibit the proliferation of SKBR3 cell in vitro.Down-regulation ErbB2 on cell plasma membrane resulting in decreasing the activation of p-Akt and p-Erk1/2 may be one of the mechanisms of the inhibitory effect.