vmip-ii and Breast-Neoplasms

Evidence has shown that microRNAs (miRNAs) are vital in cell growth, migration, and invasion by inhibiting their target genes. A previous study demonstrated that miRNA (miR)-155‑3p and miR‑155-5p exerted opposite effects on cell proliferation, apoptosis, migration and invasion in breast cancer cell lines. An miRNA microarray was used to show that miR‑155‑3p was downregulated whereas miR‑155-5p was upregulated in paclitaxel-resistant (PR) cells compared with parental breast cancer cells. However, the role of miR‑155 in breast cancer cell invasion and metastasis remains to be elucidated. A 21-residue peptide derived from the viral macrophage inflammatory protein II (NT21MP), competes with the ligand of CXC chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor-1α, inducing cell apoptosis in breast cancer. The present study aimed to identify the underlying mechanism of action of miR‑155‑3p/5p and NT21MP in PR breast cancer cells. Quantitative polymerase chain reaction, western blotting, wound-healing, cell cycle and apoptosis assays, and Cell Counting kit-8 assay were used to achieve this goal. The combined overexpression of miR‑155‑3p with NT21MP decreased the migration and invasion ability and increased the number of apoptotic and arrested cells in the G0/G1 phase transition in vitro. The knockdown of miR‑155-5p combined with NT21MP had a similar effect on PR breast cancer cells. Furthermore, the ectopic expression of their target gene myeloid differentiation primary response gene 88 (MYD88) or tumor protein 53-induced nuclear protein 1 (TP53INP1) combined with NT21MP enhanced the sensitivity of the breast cancer cells to paclitaxel. Taken together, these findings suggested that miR‑155‑3p/5p and their target genes MYD88 and TP53INP1 may serve as novel biomarkers for NT21MP therapy through the CXCR4 pathway for improving sensitivity to paclitaxel in breast cancer.

Topics: Antineoplastic Agents; Biomarkers, Tumor; Breast Neoplasms; Carrier Proteins; Cell Movement; Cell Proliferation; Chemokines; Chemotherapy, Adjuvant; Down-Regulation; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Heat-Shock Proteins; Humans; MCF-7 Cells; MicroRNAs; Myeloid Differentiation Factor 88; Paclitaxel; Peptides; Receptors, CXCR4; Signal Transduction; Viral Proteins

Accumulating evidence demonstrates that long non-coding RNA (lncRNA) sprouty4-intron transcript 1 (lncRNA SPRY4-IT1) plays a vital role in the development of breast cancer. However, the underlying mechanism has not been eventually illuminated. We aimed to explore the biological activity of lncRNA SPRY4-IT1 in breast cancer cells and whether N-terminal polypeptide derived from viral macrophage inflammatory protein II (NT21MP) could exert its anti-tumor effect by regulating lncRNA SPRY4-IT1 and its target gene

Topics: Biomarkers, Tumor; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Chemokines; Chromosomal Proteins, Non-Histone; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Herpesviridae; Humans; RNA, Long Noncoding

Acquisition of resistance to paclitaxel is one of the most important problems in treatment of breast cancer patients, but the molecular mechanisms underlying sensitivity to paclitaxel remains elusive. Emerging evidence has demonstrated that microRNAs (miRNAs) play important roles in regulation of cell growth, migration and invasion through inhibiting the expression of its target genes. In our previous studies, we have shown that microRNA-335 (miR‑335) decreased obviously between paclitaxel-resistant (PR) and parental breast cancer cells through miRNA microarray. However, the roles of miR‑335 in breast cancer progression and metastasis are still largely unknown. NT21MP was designed and synthesized as an antagonist with CXCR4 to inhibit cellular proliferation and induce apoptosis. Therefore, the aim of this study was to explore the underlying mechanism of miR‑335 and NT21MP in reverse PR in breast cancer cells. In this study, we found that miR‑335 expression is significantly lower in PR MCF‑7 and SKBR-3 cells (MCF‑7/PR and SKBR-3/PR) compared with their parental MCF‑7 and SKBR-3 cells. Functional experiments showed that overexpression of miR‑335 and NT21MP increased the number of apoptosis cells, arrested cells in G0/G1 phase transition, and suppressed cell migration and invasion in vitro. Dual luciferase assays revealed that SETD8 is a direct target gene of miR‑335. Furthermore, miR‑335 markedly inhibited expression of SETD8 via Wnt/β‑catenin signaling and subsequently inhibited the expression of its downstream genes cyclin D1, and c‑Myc. Additionally, ectopic expression of miR‑335 or depletion of its target gene SETD8 could enhance the sensitivity of PR cells to paclitaxel. Taken together, these date elucidated that NT21MP and miR‑335 mediated PR of breast cancer cells partly through regulation of Wnt/β‑catenin signaling pathway. Activation of miR‑335 or inactivation of SETD8 could be a novel approach for the treatment of breast cancer.

Topics: Apoptosis; Breast Neoplasms; Cell Movement; Cell Proliferation; Chemokines; Cyclin D1; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Histone-Lysine N-Methyltransferase; Humans; MCF-7 Cells; MicroRNAs; Paclitaxel; Peptides; Receptors, CXCR4

To assess whether NT21MP, the synthetic antagonist 21-mer peptide derived from viral macrophage inflammatory protein II inhibits human SKBR3 cells migration by interfering with SDF-1α/CXCR4 signaling.. The levels of CXCR4 were detected in breast cancer cells SKBR3 and MCF-7 by RT-PCR and immunohistochemistry. The effect of SDF-1α-induced SKBR3 migration (chemotaxis) in the presence and absence of NT21MP was determined using the Boyden chamber migration assay. Intracellular Ca(2+); concentration was measured by fluorometric analysis. Western blot analyses were performed to quantify phosphorylated ERK1/2 and FAK expression levels.. The expression of CXCR4 was higher in SKBR3 than MCF-7 cells; SKBR3 migration increased in SDF-1α-treated cells. In contrast, AMD3100, an inhibitor of CXCR4 effectively inhibited SKBR3 migration. SKBR3 migration was decreased when the cells were exposed to NT21MPdose dependently(P<0.05). NT21MP also blocked Ca(2+); influx(P<0.05), an important signal for SKBR3 migration. In addition, NT21MP significantly decreased SDF-1α-induced SKBR3 migration and downregulated SDF-1α-induced express of phospho-ERK1/2 and phospho-FAK(P<0.05).. The results showed that NT21MP has an inhibitory effect on SDF-1α-induced SKBR3 migration. The plausible mechanism of action could be upstream blockage of Ca(2+); influx and the downstream reduction of ERK1/2 and FAK signals.

Topics: Breast Neoplasms; Calcium; Chemokine CXCL12; Chemokines; Chemotaxis; Female; Focal Adhesion Protein-Tyrosine Kinases; Humans; MCF-7 Cells; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Peptides; Phosphorylation; Receptors, CXCR4

CXCR4-stromal cell-derived factor-1 (CXCR4-SDF-1alpha) system has been proved to be involved in targeting metastasis of breast cancer. Some antagonists of CXCR4 have inhibitory effects on metastasis of breast cancer. This study was to investigate effect of viral macrophage inflammatory protein-II (vMIP-II), an antagonist of CXCR4, on metastasis of breast cancer cell line MCF-7.. Proliferation of MCF-7 cells stimulated by vMIP-II of different concentrations (10, 50, 100, 500, and 1 000 ng /ml) was detected by MTT assay, clone formation rate was assessed by agar clone assay. Adhesion and chemotaxis assays were also used to evaluate the effect of vMIP-II on MCF-7 cells in different steps of metastasis.. MCF-7 cells treated with vMIP-II of a series of concentrations for 72 h showed no proliferation change (P >0.05). vMIP-II (50-1 000 ng /ml) suppressed colony formation of MCF-7 cells in a concentration-dependent manner. After MCF-7 cells treated with 300 ng/ml of vMIP-II for different time (0, 0.5, 2, and 6 h), inhibition peak of cell adherence to fibronectin (FN) and Matrigel was observed. The number of migration was low in MCF-7 cells in the presence of vMIP-II of 500 ng/ml (24+/-10) was lower than that of control MCF-7 cells (60+/-9) (P< 0.05).. The clone formation rate of MCF-7 cells may negatively correlates with the concentration of vMIP-II. vMIP-II may inhibit MCF-7 cells adhesion to FN and Matrigel, and suppress chemotactic activity of MCF-7 cells toward extracts of human lung protein.

Topics: Breast Neoplasms; Cell Adhesion; Cell Line, Tumor; Cell Migration Inhibition; Cell Movement; Cell Proliferation; Chemokines; Chemotaxis; Collagen; Dose-Response Relationship, Drug; Drug Combinations; Female; Fibronectins; Humans; Laminin; Neoplasm Metastasis; Proteoglycans; Receptors, CXCR4