Stanniocalicin 2 Suppresses Breast Cancer Cell Migration and Invasion via the PKC/Claudin-1-Mediated Signaling

Stanniocalcin (STC), a glycoprotein hormone, is expressed in a wide variety of tissues to regulate Ca2+ and PO4- homeostasis. STC2, a member of STC family, has been reported to be associated with tumor development. In this study, we investigated whether the expression of STC2 is associated with migration and invasion of breast cancer cells. We found that breast cancer cell line 231 HM transfected with STC2 shRNA displayed high motility, fibroblast morphology, and enhanced cell migration and invasion. Introduction of STC2 in 231 cells reduced cell migration and invasion. In response to irradiation, silencing of STC2 in 231 HM cells reduced apoptosis, whereas overexpression of STC2 in 231 cells promoted apoptosis, compared with in control cells. Mechanistic study showed that STC2 negatively regulated PKC to control the expression of Claudin-1, which subsequently induced the expressions of EMT-related factors including ZEB1, ZO-1, Slug, Twist, and MMP9. Suppression of PKC activity by using a PKC inhibitor (Go 6983) restored the normal motility of STC2-silenced cells. Furthermore, in vivo animal assay showed that STC2 inhibited tumorigenesis and metastasis of breast cancer cells. Collectively, these results indicate that STC2 may inhibit EMT at least partially through the PKC/Claudin-1-mediated signaling in human breast cancer cells. Thus, STC2 may be exploited as a biomarker for metastasis and targeted therapy in human breast cancer.

[1]  Jorge S Reis-Filho,et al.  Identification of NTN4, TRA1, and STC2 as Prognostic Markers in Breast Cancer in a Screen for Signal Sequence Encoding Proteins , 2007, Clinical Cancer Research.

[2]  Gong Yang,et al.  Silencing of H-ras gene expression by retrovirus-mediated siRNA decreases transformation efficiency and tumorgrowth in a model of human ovarian cancer , 2003, Oncogene.

[3]  O. Volpert,et al.  miR-200b Inhibits Prostate Cancer EMT, Growth and Metastasis , 2013, PloS one.

[4]  D. Welch,et al.  Breast Cancer Progression: Controversies and Consensus in the Molecular Mechanisms of Metastasis and EMT , 2007, Journal of Mammary Gland Biology and Neoplasia.

[5]  P. Nava,et al.  Tight junction proteins. , 2003, Progress in biophysics and molecular biology.

[6]  C. LaBonne,et al.  The F-box protein Ppa is a common regulator of core EMT factors Twist, Snail, Slug, and Sip1 , 2011, The Journal of cell biology.

[7]  K. Mimori,et al.  Clinicopathological significance of stanniocalcin 2 gene expression in colorectal cancer , 2009, International Journal of Cancer.

[8]  G. F. Wagner,et al.  Human Stanniocalcin Inhibits Renal Phosphate Excretion in the Rat , 1997, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[9]  Na Wang,et al.  Role of PKC-ERK signaling in tamoxifen-induced apoptosis and tamoxifen resistance in human breast cancer cells. , 2012, Oncology reports.

[10]  A. Fienberg,et al.  , Isabella Response with Cytoprotective Properties Target of the Mammalian Unfolded Protein Characterization of Stanniocalcin 2 , a Novel , 2004 .

[11]  C. Peng,et al.  Polyphenol-rich extracts from Solanum nigrum attenuated PKC alpha-mediated migration and invasion of hepatocellular carcinoma cells. , 2010, Journal of agricultural and food chemistry.

[12]  Melissa C Southey,et al.  Stanniocalcin 2 is an estrogen-responsive gene coexpressed with the estrogen receptor in human breast cancer. , 2002, Cancer research.

[13]  C. Wong,et al.  Stanniocalcin-2 promotes epithelial-mesenchymal transition and invasiveness in hypoxic human ovarian cancer cells. , 2010, Experimental cell research.

[14]  E. Hardeman,et al.  The murine stanniocalcin 2 gene is a negative regulator of postnatal growth. , 2008, Endocrinology.

[15]  G. Giamas,et al.  Claudin-1 as a promoter of EMT in hepatocellular carcinoma , 2013, Oncogene.

[16]  H. Olsen,et al.  Stanniocalcin: a novel protein regulating calcium and phosphate transport across mammalian intestine. , 1998, American journal of physiology. Gastrointestinal and liver physiology.

[17]  K. Yasuda,et al.  Leptin and high glucose stimulate cell proliferation in MCF-7 human breast cancer cells: reciprocal involvement of PKC-alpha and PPAR expression. , 2002, Biochimica et biophysica acta.

[18]  S. Barsky,et al.  ERα signaling through slug regulates E-cadherin and EMT , 2010, Oncogene.

[19]  D. Peeper,et al.  Deregulating EMT and senescence: double impact by a single twist. , 2008, Cancer cell.

[20]  J. Ivaska.  Vimentin: Central hub in EMT induction? , 2011, Small GTPases.

[21]  R Dulbecco,et al.  Gene expression profiles of epithelial cells microscopically isolated from a breast-invasive ductal carcinoma and a nodal metastasis , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[22]  K. H. Peterson,et al.  Protein Kinase C Activation Has Distinct Effects on the Localization, Phosphorylation and Detergent Solubility of the Claudin Protein Family in Tight and Leaky Epithelial Cells , 2010, The Journal of Membrane Biology.

[23]  G. Mills,et al.  The chemokine growth-regulated oncogene 1 (Gro-1) links RAS signaling to the senescence of stromal fibroblasts and ovarian tumorigenesis , 2006, Proceedings of the National Academy of Sciences.

[24]  G. F. Wagner,et al.  The stanniocalcin family of proteins. , 2006, Journal of experimental zoology. Part A, Comparative experimental biology.

[25]  C. Wong,et al.  Stanniocalcin-2 is a HIF-1 target gene that promotes cell proliferation in hypoxia. , 2010, Experimental cell research.

[26]  G. F. Wagner,et al.  Epigenetic and HIF-1 regulation of stanniocalcin-2 expression in human cancer cells. , 2008, Experimental cell research.

[27]  A. Weeraratna,et al.  PKC and PKA Phosphorylation Affect the Subcellular Localization of Claudin-1 in Melanoma Cells , 2009, International journal of medical sciences.

[28]  Sanda Raulic,et al.  Stanniocalcin 2 expression is regulated by hormone signalling and negatively affects breast cancer cell viability in vitro. , 2008, The Journal of endocrinology.

[29]  Yusuke Nakamura,et al.  Stanniocalcin 2 overexpression in castration‐resistant prostate cancer and aggressive prostate cancer , 2009, Cancer science.

[30]  W. Kugler,et al.  Stanniocalcin 2 promotes invasion and is associated with metastatic stages in neuroblastoma , 2009, International journal of cancer.

[31]  B. Zhou,et al.  The Role of Snail in EMT and Tumorigenesis. , 2013, Current cancer drug targets.

[32]  T. Brabletz,et al.  A reciprocal repression between ZEB1 and members of the miR-200 family promotes EMT and invasion in cancer cells , 2008, EMBO reports.

[33]  P. Meltzer,et al.  Claudin-1 overexpression in melanoma is regulated by PKC and contributes to melanoma cell motility , 2006, Oncogene.

[34]  P. Heikkilä,et al.  Tumor dormancy: elevated expression of stanniocalcins in late relapsing breast cancer. , 2008, Cancer letters.

[35]  G. F. Wagner,et al.  Human stanniocalcin-2 exhibits potent growth-suppressive properties in transgenic mice independently of growth hormone and IGFs. , 2005, American journal of physiology. Endocrinology and metabolism.

[36]  Shinzaburo Noguchi,et al.  mRNA expression level of estrogen‐inducible gene, α1‐antichymotrypsin, is a predictor of early tumor recurrence in patients with invasive breast cancers , 2004, Cancer science.

[37]  R. Reddel,et al.  Mammalian stanniocalcins and cancer. , 2003, Endocrine-related cancer.

[38]  D. Burgess.  Breast cancer: Circulating and dynamic EMT , 2013, Nature Reviews Cancer.

[39]  Shinzaburo Noguchi,et al.  Molecular classification of primary breast tumors possessing distinct prognostic properties. , 2002, Human molecular genetics.

[40]  W. Jin,et al.  Identification of the functional role of peroxiredoxin 6 in the progression of breast cancer , 2007, Breast Cancer Research.

[41]  D. Ito,et al.  Stanniocalcin 2 Is a Negative Modulator of Store-Operated Calcium Entry , 2011, Molecular and Cellular Biology.