Downregulated miR-45 Inhibits the G1-S Phase Transition by Targeting Bmi-1 in Breast Cancer

AbstractBmi-1 (B cell-specific Moloney murine leukemia virus integration site 1) is upregulated in breast cancer and was involved in many malignant progressions of breast cells, including cell proliferation, stem cell pluripotency, and cancer initiation. However, the epigenetic regulatory mechanism of Bmi-1 in breast cancer remains unclear.After analysis of the ArrayExpress dataset GSE45666, we comparatively detected the expression levels of miR-495 in 9 examined breast cancer cell lines, normal breast epithelial cells and 8 pairs of fresh clinical tumor samples. Furthermore, to evaluate the effect of miR-495 on the progression of breast cancer, MCF-7 and MDA-MB-231 were transduced to stably overexpress miR-495. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, colony formation assays, 5-Bromo-2-deoxyUridine labeling and immunofluorescence, anchorage-independent growth ability assay, flow cytometry analysis, and luciferase assays were used to test the effect of miR-495 in MCF-7 and MDA-MB-231 cells in vitro. Xenografted tumor model was also used to evaluate the effect of miR-495 in breast cancer.Herein, we found that miR-495, a predicted regulator of Bmi-1, was frequently downregulated in malignant cells and tissues of breast. Upregulation of miR-495 significantly suppressed breast cancer cell proliferation and tumorigenicity via G1-S arrest. Further analysis revealed that miR-495 targeted Bmi-1 through its 3′ untranslated region. Moreover, Bmi-1 could neutralize the suppressive effect of miR-495 on cell proliferation and tumorigenicity of breast cancer in vivo.These data suggested that miR-495 could inhibit the G1-S phase transition that leads to proliferation and tumorigenicity inhibition by targeting and suppressing Bmi-1 in breast cancer.

[1]  J. Cuzick,et al.  Update on breast cancer risk prediction and prevention , 2015, Current opinion in obstetrics & gynecology.

[2]  Changjiang Qin,et al.  XRCC2 Promotes Colorectal Cancer Cell Growth, Regulates Cell Cycle Progression, and Apoptosis , 2014, Medicine.

[3]  A. Levine,et al.  MicroRNAs, miR-154, miR-299-5p, miR-376a, miR-376c, miR-377, miR-381, miR-487b, miR-485-3p, miR-495 and miR-654-3p, mapped to the 14q32.31 locus, regulate proliferation, apoptosis, migration and invasion in metastatic prostate cancer cells , 2014, Oncogene.

[4]  Xueyun Zhong,et al.  MicroRNA‐221 targeting PI3‐K/Akt signaling axis induces cell proliferation and BCNU resistance in human glioblastoma , 2014, Neuropathology : official journal of the Japanese Society of Neuropathology.

[5]  K. Zen,et al.  MicroRNA-495 induces breast cancer cell migration by targeting JAM-A , 2014, Protein & Cell.

[6]  Wei R. Chen,et al.  Mir-208 promotes cell proliferation by repressing SOX6 expression in human esophageal squamous cell carcinoma , 2014, Journal of Translational Medicine.

[7]  Liqiang Song,et al.  miR‐495 Enhances the Sensitivity of Non‐Small Cell Lung Cancer Cells to Platinum by Modulation of Copper‐Transporting P‐type Adenosine Triphosphatase A (ATP7A) , 2014, Journal of cellular biochemistry.

[8]  R. Weinberg,et al.  Tackling the cancer stem cells — what challenges do they pose? , 2014, Nature Reviews Drug Discovery.

[9]  Xiang Lu,et al.  Bmi-1 plays a critical role in protection from renal tubulointerstitial injury by maintaining redox balance , 2014, Aging cell.

[10]  Xin Chen,et al.  miRNA-128 suppresses prostate cancer by inhibiting BMI-1 to inhibit tumor-initiating cells. , 2014, Cancer research.

[11]  Pei Zhang,et al.  Down Regulation of miR200c Promotes Radiation‐Induced Thymic Lymphoma by Targeting BMI1 , 2014, Journal of cellular biochemistry.

[12]  Hugo Naya,et al.  Activation of the PI3K/AKT pathway by microRNA-22 results in CLL B-cell proliferation , 2014, Leukemia.

[13]  W. Di,et al.  MicroRNA-7 Inhibits Tumor Metastasis and Reverses Epithelial-Mesenchymal Transition through AKT/ERK1/2 Inactivation by Targeting EGFR in Epithelial Ovarian Cancer , 2014, PloS one.

[14]  Kang Yang,et al.  MiR-21 inhibits c-Ski signaling to promote the proliferation of rat vascular smooth muscle cells. , 2014, Cellular signalling.

[15]  H. El-Hadaad,et al.  Immunohistochemical expression and prognostic relevance of Bmi-1, a stem cell factor, in epithelial ovarian cancer. , 2014, Annals of diagnostic pathology.

[16]  Li-ping Guo,et al.  miR-203 inhibits the proliferation and self-renewal of esophageal cancer stem-like cells by suppressing stem renewal factor Bmi-1. , 2014, Stem cells and development.

[17]  Libing Song,et al.  Overexpression of AKIP1 promotes angiogenesis and lymphangiogenesis in human esophageal squamous cell carcinoma , 2014, Oncogene.

[18]  A. Margulis,et al.  Changes of PI3K/AKT/BCL2 signaling proteins in congenital Giant Nevi: melanocytes contribute to their increased survival and integrity , 2013, Journal of receptor and signal transduction research.

[19]  Shanling Liu,et al.  miR-126 Suppresses the proliferation of cervical cancer cells and alters cell sensitivity to the chemotherapeutic drug bleomycin. , 2013, Asian Pacific journal of cancer prevention : APJCP.

[20]  H. Qin,et al.  MiR-34a targets GAS1 to promote cell proliferation and inhibit apoptosis in papillary thyroid carcinoma via PI3K/Akt/Bad pathway. , 2013, Biochemical and biophysical research communications.

[21]  Ana Kozomara,et al.  miRBase: annotating high confidence microRNAs using deep sequencing data , 2013, Nucleic Acids Res..

[22]  Liang Zhou,et al.  Overexpression of Bmi-1 contributes to the invasion and metastasis of hepatocellular carcinoma by increasing the expression of matrix metalloproteinase (MMP)‑2, MMP-9 and vascular endothelial growth factor via the PTEN/PI3K/Akt pathway. , 2013, International journal of oncology.

[23]  H. Shigeishi,et al.  AKT primes snail‐induced EMT concomitantly with the collective migration of squamous cell carcinoma cells , 2013, Journal of cellular biochemistry.

[24]  Zengtong Zhou,et al.  Bmi1 expression in oral lichen planus and the risk of progression to oral squamous cell carcinoma. , 2013, Annals of diagnostic pathology.

[25]  A. Lam,et al.  BMI-1 activation is crucial in hTERT-induced epithelial-mesenchymal transition of oral epithelial cells. , 2013, Experimental and molecular pathology.

[26]  M. S. Parvathi,et al.  Regulation of BMI1 Polycomb gene expression in histological grades of invasive ductal breast carcinomas and its correlation with hormone receptor status , 2013, Tumor Biology.

[27]  R. Blelloch,et al.  miR-294/miR-302 promotes proliferation, suppresses G1-S restriction point, and inhibits ESC differentiation through separable mechanisms. , 2013, Cell reports.

[28]  M. Zeng,et al.  Sp1 and c‐Myc regulate transcription of BMI1 in nasopharyngeal carcinoma , 2013, The FEBS journal.

[29]  Shu-Jen Chen,et al.  MicroRNA-495 inhibits proliferation of glioblastoma multiforme cells by downregulating cyclin-dependent kinase 6 , 2013, World Journal of Surgical Oncology.

[30]  R. Balleine,et al.  Ki67 and proliferation in breast cancer , 2013, Journal of Clinical Pathology.

[31]  Xun Zhu,et al.  Bmi-1 Promotes Glioma Angiogenesis by Activating NF-κB Signaling , 2013, PloS one.

[32]  T. Godfrey,et al.  Clinicopathologic characteristics of high expression of Bmi-1 in esophageal adenocarcinoma and squamous cell carcinoma , 2012, BMC Gastroenterology.

[33]  Dong-Woo Lee,et al.  miR-495 and miR-551a inhibit the migration and invasion of human gastric cancer cells by directly interacting with PRL-3. , 2012, Cancer letters.

[34]  P. Nelson,et al.  VEGF/neuropilin-2 regulation of Bmi-1 and consequent repression of IGF-IR define a novel mechanism of aggressive prostate cancer. , 2012, Cancer discovery.

[35]  Byeong-Moo Kim,et al.  Non-canonical microRNAs miR-320 and miR-702 promote proliferation in Dgcr8-deficient embryonic stem cells. , 2012, Biochemical and biophysical research communications.

[36]  L. Cai,et al.  Expression patterns of USP22 and potential targets BMI-1, PTEN, p-AKT in non-small-cell lung cancer. , 2012, Lung cancer.

[37]  Ali Montazeri,et al.  Literacy and breast cancer prevention: a population-based study from Iran. , 2012, Asian Pacific journal of cancer prevention : APJCP.

[38]  H. G. van der Poel,et al.  Akt-mediated phosphorylation of Bmi1 modulates its oncogenic potential, E3 ligase activity, and DNA damage repair activity in mouse prostate cancer. , 2012, The Journal of clinical investigation.

[39]  L. Min,et al.  Clinicopathological and prognostic significance of Bmi‐1 expression in human cervical cancer , 2011, Acta obstetricia et gynecologica Scandinavica.

[40]  King-Jen Chang,et al.  miR-495 is upregulated by E12/E47 in breast cancer stem cells, and promotes oncogenesis and hypoxia resistance via downregulation of E-cadherin and REDD1 , 2011, Oncogene.

[41]  Libing Song,et al.  Bmi-1 promotes invasion and metastasis, and its elevated expression is correlated with an advanced stage of breast cancer , 2011, Molecular Cancer.

[42]  P. Fisher,et al.  Expression patterns of astrocyte elevated gene-1 (AEG-1) during development of the mouse embryo. , 2010, Gene expression patterns : GEP.

[43]  Libing Song,et al.  Unregulated miR-96 Induces Cell Proliferation in Human Breast Cancer by Downregulating Transcriptional Factor FOXO3a , 2010, PloS one.

[44]  Libing Song,et al.  Sam68 up‐regulation correlates with, and its down‐regulation inhibits, proliferation and tumourigenicity of breast cancer cells , 2010, The Journal of pathology.

[45]  M. Cooperberg,et al.  Electronic patient self-assessment and management (SAM): a novel framework for cancer survivorship , 2010, BMC Medical Informatics Decis. Mak..

[46]  Goberdhan P Dimri,et al.  BMI1 and Mel-18 oppositely regulate carcinogenesis and progression of gastric cancer , 2010, Molecular Cancer.

[47]  P. Fisher,et al.  Astrocyte elevated gene-1 (AEG-1) functions as an oncogene and regulates angiogenesis , 2009, Proceedings of the National Academy of Sciences.

[48]  Wenlin Huang,et al.  The polycomb group protein Bmi-1 represses the tumor suppressor PTEN and induces epithelial-mesenchymal transition in human nasopharyngeal epithelial cells. , 2009, The Journal of clinical investigation.

[49]  M. Huang,et al.  The Growth Factor Independence-1 (Gfi1) Is Overexpressed in Chronic Myelogenous Leukemia , 2009, Acta Haematologica.

[50]  U. Rapp,et al.  Polycomb Group Protein Bmi1 Is Required for Growth of RAF Driven Non-Small-Cell Lung Cancer , 2009, PloS one.

[51]  A. Iwama,et al.  The polycomb gene product BMI1 contributes to the maintenance of tumor-initiating side population cells in hepatocellular carcinoma. , 2008, Cancer research.

[52]  A. Paetau,et al.  Stem cell protein BMI‐1 is an independent marker for poor prognosis in oligodendroglial tumours , 2008, Neuropathology and applied neurobiology.

[53]  N. Raab-Traub,et al.  EBV Latent Membrane Protein 1 Activates Akt, NFκB, and Stat3 in B Cell Lymphomas , 2007, PLoS pathogens.

[54]  W. Tilley,et al.  Role of oncoprotein Growth Factor Independent-1 (GFI1) in repression of 25-hydroxyvitamin D 1alpha-hydroxylase (CYP27B1): A comparative analysis in human prostate cancer and kidney cells , 2007, The Journal of Steroid Biochemistry and Molecular Biology.

[55]  Yun-Fei Xia,et al.  Bmi-1 is a novel molecular marker of nasopharyngeal carcinoma progression and immortalizes primary human nasopharyngeal epithelial cells. , 2006, Cancer research.

[56]  T. Sauka-Spengler,et al.  Expression of the polycomb group gene bmi-1 in the early chick embryo. , 2004, Gene expression patterns : GEP.

[57]  C. Gilks,et al.  Growth Factor Independence-1 Is Expressed in Primary Human Neuroendocrine Lung Carcinomas and Mediates the Differentiation of Murine Pulmonary Neuroendocrine Cells , 2004, Cancer Research.

[58]  K Kornfeld,et al.  Multiple docking sites on substrate proteins form a modular system that mediates recognition by ERK MAP kinase. , 1999, Genes & development.

[59]  R. DePinho,et al.  The oncogene and Polycomb-group gene bmi-1 regulates cell proliferation and senescence through the ink4a locus , 1999, Nature.

[60]  Chao Qin,et al.  miR-154 inhibits prostate cancer cell proliferation by targeting CCND2. , 2014, Urologic oncology.

[61]  A. Berns,et al.  Bmi-1 collaborates with c-Myc in tumorigenesis by inhibiting c-Myc-induced apoptosis via INK4a/ARF. , 1999, Genes & development.