Shara Reihani - Academia.edu (original) (raw)

Papers by Shara Reihani

Molecular Cancer Therapeutics, 2013

Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast can... more Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast cancer and stimulates angiogenesis via activation of the calcineurin/NFATc3 pathway. There are conflicting reports in the literature as to whether SFRP2 is an antagonist or agonist of β-catenin. The aims of these studies were to assess the effects of SFRP2 antagonism on tumor growth and Wnt-signaling and to evaluate whether SFRP2 is a viable therapeutic target. The antiangiogenic and antitumor properties of SFRP2 monoclonal antibody (mAb) were assessed using in vitro proliferation, migration, tube formation assays, and in vivo angiosarcoma and triple-negative breast cancer models. Wnt-signaling was assessed in endothelial and tumor cells treated with SFRP2 mAb using Western blotting. Pharmacokinetic and biodistribution data were generated in tumor-bearing and nontumor-bearing mice. SFRP2 mAb was shown to induce antitumor and antiangiogenic effects in vitro and inhibit activation of β-cateni...

Journal of Surgical Research, 2011

Cancer Research, 2010

Objectives: We have previously discovered a novel angiogenesis factor, secreted frizzle-related p... more Objectives: We have previously discovered a novel angiogenesis factor, secreted frizzle-related protein 2 (SFRP2), that is strongly expressed in many human tumors including ovarian carcinoma. SFRP2 protects against endothelial cell apoptosis, and induces endothelial tube formation and migration. We hypothesize that in addition to its paracrine role in stimulating angiogenesis, SFRP2 also has a direct effect in tumor cells, and therefore blocking SFRP2 will induce ovarian cancer apoptosis. Methods: Protein expression of SFRP2 in ovarian cancer cells: SKOV-3 and OVCA −3 ovarian cancer cells were cultured in McCoy's medium with 10% bovine serum albumin. Whole cell protein lysates were obtained and Western blot analysis was performed probing for SFRP2. Apoptosis assay: SKOV3 cells were plated in 96 well plates and allowed to attach overnight. Rabbit polyclonal antibody to SFRP2 (SFRP2 Ab) was run through a column with a saline buffer to remove the sodium azide preservative. Cells we...

Cancer Research, 2011

Background: Secreted frizzled related protein 2 (SFRP2) is a novel angiogenesis factor expressed ... more Background: Secreted frizzled related protein 2 (SFRP2) is a novel angiogenesis factor expressed in the endothelium of a wide variety of human tumors including triple negative breast cancer and angiosarcoma. We previously reported generating a monoclonal antibody against SFRP2 that inhibits endothelial cell and angiosarcoma tube formation in vitro, and decreased tumor volume of the SVR angiosarcoma in vivo. The objectives of these studies were to determine pharmacokinetic (PK) and pharmacodynamic (PD) parameters of the SFRP2 MAb, and evaluate its efficacy in a triple negative breast cancer xenograft. Methods: 125 I-SFRP2 MAb was administered to nude mice i.v. via tail vein injections at 0.4 mg/kg, 4 mg/kg, or 10 mg/kg in mice with or without tumor. Blood organ, and tumor samples were collected at various time points from 5 min to 21 days. Radiolabeled SFRP2 MAb in serum and tissues was determined using a gamma counter. PK parameters were determined based on mean concentration values...

International Journal of Hyperthermia, 2015

Cancer Research, 2011

Introduction: Inflammatory breast cancer (IBC) is the most fatal form of breast cancer (BC) with ... more Introduction: Inflammatory breast cancer (IBC) is the most fatal form of breast cancer (BC) with unknown etiology. IBC is characterized by rapid onset (3-6 month) with unusual clinical presentation (redness, edema, warmth, and pain), sometimes without an underlying tumor mass, whereas non-inflammatory BC most often presents as painless breast mass. IBC also presents with higher nuclear grade, more frequent involvement of lymph nodes, and negative hormone receptor status than non-inflammatory locally-advanced BC (NI-LABC). Finally, the incidence age-pattern of IBC has been shown to be distinctly different from NI-LABC. The differences in the cancer incidence age-patterns, as hypothesized by Armitage and Doll, reflect different number of successive cellular transitions necessary for the development of a clinically significant malignancy. We used extended Armitage-Doll model and SEER data for 2004-2007 to describe age-patterns of IBC and NI-LABC incidence and to estimate the number of ...

Breast Cancer Research and Treatment, 2011

Inflammatory Breast Carcinoma (IBC), the most aggressive type of breast tumor with unique clinico... more Inflammatory Breast Carcinoma (IBC), the most aggressive type of breast tumor with unique clinicopathological presentation, is hypothesized to have distinct etiology with a socioeconomic status (SES) component. Using the Surveillance, Epidemiology and End Results (SEER) Program data for 2004-2007, we compare incidence rates of IBC to non-inflammatory locally advanced breast cancer (LABC) among racial/ethnic groups with different SES. The analysis includes women 20-84 years of age. To examine evidence for the distinct etiology of IBC, we analyzed age-distribution patterns of IBC and non-inflammatory LABC, using a mathematical carcinogenesis model. Based on the Collaborative Staging Extension codes, 2,942 incident IBC cases (codes 71 and 73) and 5,721 non-inflammatory LABC cases (codes 40-62) were identified during the four-year study period. Age-adjusted rates of IBC among non-Hispanic White and Hispanic women were similar (2.5/100,000 in both groups). Similar rates were also found in noninflammatory LABC in these two groups (4.8/100,000 and 4.2/100,000, respectively). In African-American women, the IBC (3.91/100,000) and non-inflammatory LABC (8.47/100,000) rates were greater compared with other ethnic/racial subgroups. However, the ratio of rates of IBC/ non-inflammatory LABC was similar among all the racial/ethnic groups, suggesting that African-American women are susceptible to aggressive breast tumors in general but not specifically to IBC. The mathematical model successfully predicted the observed age-specific rates of both examined breast tumors and revealed distinct patterns. IBC rates increased until age 65 and then slightly decreased, whereas non-inflammatory LABC rates steadily increased throughout the entire age interval. The number of critical transition carcinogenesis stages (m-stages) predicted by the

Cancer Research, 2009

Secreted frizzle-related protein 2 (SFRP2), a modulator of Wnt signaling, has recently been found... more Secreted frizzle-related protein 2 (SFRP2), a modulator of Wnt signaling, has recently been found to be overexpressed in the vasculature of 85% of human breast tumors; however, its role in angiogenesis is unknown. We found that SFRP2 induced angiogenesis in the mouse Matrigel plug assay and the chick chorioallantoic membrane assay. SFRP2 inhibited hypoxia induced endothelial cell apoptosis, increased endothelial cell migration, and induced endothelial tube formation. The canonical Wnt pathway was not affected by SFRP2 in endothelial cells; however, a component of the noncanonical Wnt/Ca2+ pathway was affected by SFRP2 as shown by an increase in NFATc3 in the nuclear fraction of SFRP2-treated endothelial cells. Tacrolimus, a calcineurin inhibitor that inhibits dephosphorylation of NFAT, inhibited SFRP2-induced endothelial tube formation. Tacrolimus 3 mg/kg/d inhibited the growth of SVR angiosarcoma xenografts in mice by 46% (P = 0.04). In conclusion, SFRP2 is a novel stimulator of an...

Journal of Molecular Recognition, 2009

Grb7 is an adaptor molecule that can mediate signal transduction from multiple cell surface recep... more Grb7 is an adaptor molecule that can mediate signal transduction from multiple cell surface receptors to various downstream signaling pathways. Grb7, along with Grb10 and Grb14, make up the Grb7 protein family. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7 and a receptor tyrosine kinase (RTK), erbB2, are overexpressed in 20-30% of breast cancers. Grb7 overexpression has been linked to enhanced cell migration and metastasis, though the participants in these pathways have not been determined. In this study, we report that Grb7 interacts with four and half lim domains isoform 2 (FHL2), a transcription regulator with an important role in oncogenesis, including breast cancer. Additionally, in yeast 2-hybrid (Y2H) assays, we show that the interaction is specific to the Grb7 RA and PH domains. We have also demonstrated that full-length (FL) Grb7 and FHL2 interact in mammalian cells and that Grb7 must be tyrosine phosphorylated for this interaction to occur. Immunofluorescent microscopy demonstrates possible co-localization of Grb7 and FHL2. A model with supporting NMR evidence of Grb7 autoinhibition is proposed.

Free Radical Biology and Medicine

Journal of Molecular Recognition, 2010

Adaptor proteins mediate signal transduction from cell surface receptors to downstream signaling ... more Adaptor proteins mediate signal transduction from cell surface receptors to downstream signaling pathways. The Grb7 protein family of adaptor proteins is constituted by Grb7, Grb10, and Grb14. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7-mediated cell migration has been shown to proceed through a focal adhesion kinase (FAK)/Grb7 pathway, although the specific participants downstream of Grb7 in cell migration signaling have not been fully determined. In this study, we report that Grb7 interacts with Hax-1, a cytoskeletal-associated protein found overexpressed in metastatic tumors and cancer cell lines. Additionally, in yeast 2-hybrid assays, we show that the interaction is specific to the Grb7-RA and -PH domains. We have also demonstrated that full-length Grb7 and Hax-1 interact in mammalian cells and that Grb7 is tyrosine phosphorylated. Isothermal titration calorimetry measurements demonstrate the Grb7-RA-PH domains bind to the Grb7-SH2 domain with micromolar affinity, suggesting full-length Grb7 can exist in a head-to-tail conformational state that could serve a self-regulatory function.

PLoS ONE, 2011

Tacrolimus (FK506) is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506... more Tacrolimus (FK506) is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506-FKBP12 complex associates with calcineurin and inhibits its phosphatase activity, resulting in inhibition of nuclear translocation of nuclear factor of activated T-cells (NFAT). There is increasing data supporting a critical role of NFAT in mediating angiogenic responses stimulated by both vascular endothelial growth factor (VEGF) and a novel angiogenesis factor, secreted frizzledrelated protein 2 (SFRP2). Since both VEGF and SFRP2 are expressed in breast carcinomas, we hypothesized that tacrolimus would inhibit breast carcinoma growth. Using IHC (IHC) with antibodies to FKBP12 on breast carcinomas we found that FKBP12 localizes to breast tumor vasculature. Treatment of MMTV-neu transgenic mice with tacrolimus (3 mg/kg i.p. daily) (n = 19) resulted in a 73% reduction in the growth rate for tacrolimus treated mice compared to control (n = 15), p = 0.003; which was associated with an 82% reduction in tumor microvascular density (p,0.001) by IHC. Tacrolimus (1 mM) inhibited SFRP2 induced endothelial tube formation by 71% (p = 0.005) and inhibited VEGF induced endothelial tube formation by 67% (p = 0.004). To show that NFATc3 is required for SFRP2 stimulated angiogenesis, NFATc3 was silenced with shRNA in endothelial cells. Sham transfected cells responded to SFRP2 stimulation in a tube formation assay with an increase in the number of branch points (p,0.003), however, cells transfected with shRNA to NFATc3 showed no increase in tube formation in response to SFRP2. This demonstrates that NFATc3 is required for SFRP2 induced tube formation, and tacrolimus inhibits angiogenesis in vitro and breast carcinoma growth in vivo. This provides a rationale for examining the therapeutic potential of tacrolimus at inhibiting breast carcinoma growth in humans. Citation: Siamakpour-Reihani S, Caster J, Bandhu Nepal D, Courtwright A, Hilliard E, et al. (2011) The Role of Calcineurin/NFAT in SFRP2 Induced Angiogenesis-A Rationale for Breast Cancer Treatment with the Calcineurin Inhibitor Tacrolimus. PLoS ONE 6(6): e20412.

Journal of the American College of Surgeons, 2008

block proliferation of cancer cells. The object of our approach was to identify domains from the ... more block proliferation of cancer cells. The object of our approach was to identify domains from the p53 protein that possess anti-cancer activity. We accomplished this by synthesizing peptides corresponding to the hdm-2-binding domain (residues 12-26) and linked them to a trans-membrane-penetrating sequence. The anti-cancer activity of one such peptide designated PNC-27 was then tested against human pancreatic cancer cells and the mechanism studied. METHODS: MiaPaCa-2 human pancreatic carcinoma cells were treated daily with PNC-27. During this time, we recorded changes in cell morphology and growth characteristics among treated and control groups. Necrosis mediated by peptide was determined by measuring lactate dehydrogenase (LDH) as well as elevation of proapoptotic proteins. Treatment with fluorescent labeled peptide, immunoprecipitation (IP), and time lapse electron microscopy (EM) were employed to elucidate the anti-cancer mechanism.

Molecular Cancer Therapeutics, 2013

Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast can... more Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast cancer and stimulates angiogenesis via activation of the calcineurin/NFATc3 pathway. There are conflicting reports in the literature as to whether SFRP2 is an antagonist or agonist of b-catenin. The aims of these studies were to assess the effects of SFRP2 antagonism on tumor growth and Wnt-signaling and to evaluate whether SFRP2 is a viable therapeutic target. The antiangiogenic and antitumor properties of SFRP2 monoclonal antibody (mAb) were assessed using in vitro proliferation, migration, tube formation assays, and in vivo angiosarcoma and triplenegative breast cancer models. Wnt-signaling was assessed in endothelial and tumor cells treated with SFRP2 mAb using Western blotting. Pharmacokinetic and biodistribution data were generated in tumor-bearing and nontumor-bearing mice. SFRP2 mAb was shown to induce antitumor and antiangiogenic effects in vitro and inhibit activation of b-catenin and nuclear factor of activated T-cells c3 (NFATc3) in endothelial and tumor cells. Treatment of SVR angiosarcoma allografts in nude mice with the SFRP2 mAb decreased tumor volume by 58% compared with control (P ¼ 0.004). Treatment of MDA-MB-231 breast carcinoma xenografts with SFRP2 mAb decreased tumor volume by 52% (P ¼ 0.03) compared with control, whereas bevacizumab did not significantly reduce tumor volume. Pharmacokinetic studies show the antibody is long circulating in the blood and preferentially accumulates in SFRP2-positive tumors. In conclusion, antagonizing SFRP2 inhibits activation of b-catenin and NFATc3 in endothelial and tumor cells and is a novel therapeutic approach for inhibiting angiosarcoma and triple-negative breast cancer. Mol Cancer Ther; 12(5); 685-95. Ó2013 AACR.

Molecular Cancer Therapeutics, 2013

Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast can... more Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast cancer and stimulates angiogenesis via activation of the calcineurin/NFATc3 pathway. There are conflicting reports in the literature as to whether SFRP2 is an antagonist or agonist of β-catenin. The aims of these studies were to assess the effects of SFRP2 antagonism on tumor growth and Wnt-signaling and to evaluate whether SFRP2 is a viable therapeutic target. The antiangiogenic and antitumor properties of SFRP2 monoclonal antibody (mAb) were assessed using in vitro proliferation, migration, tube formation assays, and in vivo angiosarcoma and triple-negative breast cancer models. Wnt-signaling was assessed in endothelial and tumor cells treated with SFRP2 mAb using Western blotting. Pharmacokinetic and biodistribution data were generated in tumor-bearing and nontumor-bearing mice. SFRP2 mAb was shown to induce antitumor and antiangiogenic effects in vitro and inhibit activation of β-cateni...

Journal of Surgical Research, 2011

Cancer Research, 2010

Objectives: We have previously discovered a novel angiogenesis factor, secreted frizzle-related p... more Objectives: We have previously discovered a novel angiogenesis factor, secreted frizzle-related protein 2 (SFRP2), that is strongly expressed in many human tumors including ovarian carcinoma. SFRP2 protects against endothelial cell apoptosis, and induces endothelial tube formation and migration. We hypothesize that in addition to its paracrine role in stimulating angiogenesis, SFRP2 also has a direct effect in tumor cells, and therefore blocking SFRP2 will induce ovarian cancer apoptosis. Methods: Protein expression of SFRP2 in ovarian cancer cells: SKOV-3 and OVCA −3 ovarian cancer cells were cultured in McCoy's medium with 10% bovine serum albumin. Whole cell protein lysates were obtained and Western blot analysis was performed probing for SFRP2. Apoptosis assay: SKOV3 cells were plated in 96 well plates and allowed to attach overnight. Rabbit polyclonal antibody to SFRP2 (SFRP2 Ab) was run through a column with a saline buffer to remove the sodium azide preservative. Cells we...

Cancer Research, 2011

Background: Secreted frizzled related protein 2 (SFRP2) is a novel angiogenesis factor expressed ... more Background: Secreted frizzled related protein 2 (SFRP2) is a novel angiogenesis factor expressed in the endothelium of a wide variety of human tumors including triple negative breast cancer and angiosarcoma. We previously reported generating a monoclonal antibody against SFRP2 that inhibits endothelial cell and angiosarcoma tube formation in vitro, and decreased tumor volume of the SVR angiosarcoma in vivo. The objectives of these studies were to determine pharmacokinetic (PK) and pharmacodynamic (PD) parameters of the SFRP2 MAb, and evaluate its efficacy in a triple negative breast cancer xenograft. Methods: 125 I-SFRP2 MAb was administered to nude mice i.v. via tail vein injections at 0.4 mg/kg, 4 mg/kg, or 10 mg/kg in mice with or without tumor. Blood organ, and tumor samples were collected at various time points from 5 min to 21 days. Radiolabeled SFRP2 MAb in serum and tissues was determined using a gamma counter. PK parameters were determined based on mean concentration values...

International Journal of Hyperthermia, 2015

Cancer Research, 2011

Introduction: Inflammatory breast cancer (IBC) is the most fatal form of breast cancer (BC) with ... more Introduction: Inflammatory breast cancer (IBC) is the most fatal form of breast cancer (BC) with unknown etiology. IBC is characterized by rapid onset (3-6 month) with unusual clinical presentation (redness, edema, warmth, and pain), sometimes without an underlying tumor mass, whereas non-inflammatory BC most often presents as painless breast mass. IBC also presents with higher nuclear grade, more frequent involvement of lymph nodes, and negative hormone receptor status than non-inflammatory locally-advanced BC (NI-LABC). Finally, the incidence age-pattern of IBC has been shown to be distinctly different from NI-LABC. The differences in the cancer incidence age-patterns, as hypothesized by Armitage and Doll, reflect different number of successive cellular transitions necessary for the development of a clinically significant malignancy. We used extended Armitage-Doll model and SEER data for 2004-2007 to describe age-patterns of IBC and NI-LABC incidence and to estimate the number of ...

Breast Cancer Research and Treatment, 2011

Inflammatory Breast Carcinoma (IBC), the most aggressive type of breast tumor with unique clinico... more Inflammatory Breast Carcinoma (IBC), the most aggressive type of breast tumor with unique clinicopathological presentation, is hypothesized to have distinct etiology with a socioeconomic status (SES) component. Using the Surveillance, Epidemiology and End Results (SEER) Program data for 2004-2007, we compare incidence rates of IBC to non-inflammatory locally advanced breast cancer (LABC) among racial/ethnic groups with different SES. The analysis includes women 20-84 years of age. To examine evidence for the distinct etiology of IBC, we analyzed age-distribution patterns of IBC and non-inflammatory LABC, using a mathematical carcinogenesis model. Based on the Collaborative Staging Extension codes, 2,942 incident IBC cases (codes 71 and 73) and 5,721 non-inflammatory LABC cases (codes 40-62) were identified during the four-year study period. Age-adjusted rates of IBC among non-Hispanic White and Hispanic women were similar (2.5/100,000 in both groups). Similar rates were also found in noninflammatory LABC in these two groups (4.8/100,000 and 4.2/100,000, respectively). In African-American women, the IBC (3.91/100,000) and non-inflammatory LABC (8.47/100,000) rates were greater compared with other ethnic/racial subgroups. However, the ratio of rates of IBC/ non-inflammatory LABC was similar among all the racial/ethnic groups, suggesting that African-American women are susceptible to aggressive breast tumors in general but not specifically to IBC. The mathematical model successfully predicted the observed age-specific rates of both examined breast tumors and revealed distinct patterns. IBC rates increased until age 65 and then slightly decreased, whereas non-inflammatory LABC rates steadily increased throughout the entire age interval. The number of critical transition carcinogenesis stages (m-stages) predicted by the

Cancer Research, 2009

Secreted frizzle-related protein 2 (SFRP2), a modulator of Wnt signaling, has recently been found... more Secreted frizzle-related protein 2 (SFRP2), a modulator of Wnt signaling, has recently been found to be overexpressed in the vasculature of 85% of human breast tumors; however, its role in angiogenesis is unknown. We found that SFRP2 induced angiogenesis in the mouse Matrigel plug assay and the chick chorioallantoic membrane assay. SFRP2 inhibited hypoxia induced endothelial cell apoptosis, increased endothelial cell migration, and induced endothelial tube formation. The canonical Wnt pathway was not affected by SFRP2 in endothelial cells; however, a component of the noncanonical Wnt/Ca2+ pathway was affected by SFRP2 as shown by an increase in NFATc3 in the nuclear fraction of SFRP2-treated endothelial cells. Tacrolimus, a calcineurin inhibitor that inhibits dephosphorylation of NFAT, inhibited SFRP2-induced endothelial tube formation. Tacrolimus 3 mg/kg/d inhibited the growth of SVR angiosarcoma xenografts in mice by 46% (P = 0.04). In conclusion, SFRP2 is a novel stimulator of an...

Journal of Molecular Recognition, 2009

Grb7 is an adaptor molecule that can mediate signal transduction from multiple cell surface recep... more Grb7 is an adaptor molecule that can mediate signal transduction from multiple cell surface receptors to various downstream signaling pathways. Grb7, along with Grb10 and Grb14, make up the Grb7 protein family. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7 and a receptor tyrosine kinase (RTK), erbB2, are overexpressed in 20-30% of breast cancers. Grb7 overexpression has been linked to enhanced cell migration and metastasis, though the participants in these pathways have not been determined. In this study, we report that Grb7 interacts with four and half lim domains isoform 2 (FHL2), a transcription regulator with an important role in oncogenesis, including breast cancer. Additionally, in yeast 2-hybrid (Y2H) assays, we show that the interaction is specific to the Grb7 RA and PH domains. We have also demonstrated that full-length (FL) Grb7 and FHL2 interact in mammalian cells and that Grb7 must be tyrosine phosphorylated for this interaction to occur. Immunofluorescent microscopy demonstrates possible co-localization of Grb7 and FHL2. A model with supporting NMR evidence of Grb7 autoinhibition is proposed.

Free Radical Biology and Medicine

Journal of Molecular Recognition, 2010

Adaptor proteins mediate signal transduction from cell surface receptors to downstream signaling ... more Adaptor proteins mediate signal transduction from cell surface receptors to downstream signaling pathways. The Grb7 protein family of adaptor proteins is constituted by Grb7, Grb10, and Grb14. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7-mediated cell migration has been shown to proceed through a focal adhesion kinase (FAK)/Grb7 pathway, although the specific participants downstream of Grb7 in cell migration signaling have not been fully determined. In this study, we report that Grb7 interacts with Hax-1, a cytoskeletal-associated protein found overexpressed in metastatic tumors and cancer cell lines. Additionally, in yeast 2-hybrid assays, we show that the interaction is specific to the Grb7-RA and -PH domains. We have also demonstrated that full-length Grb7 and Hax-1 interact in mammalian cells and that Grb7 is tyrosine phosphorylated. Isothermal titration calorimetry measurements demonstrate the Grb7-RA-PH domains bind to the Grb7-SH2 domain with micromolar affinity, suggesting full-length Grb7 can exist in a head-to-tail conformational state that could serve a self-regulatory function.

PLoS ONE, 2011

Tacrolimus (FK506) is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506... more Tacrolimus (FK506) is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506-FKBP12 complex associates with calcineurin and inhibits its phosphatase activity, resulting in inhibition of nuclear translocation of nuclear factor of activated T-cells (NFAT). There is increasing data supporting a critical role of NFAT in mediating angiogenic responses stimulated by both vascular endothelial growth factor (VEGF) and a novel angiogenesis factor, secreted frizzledrelated protein 2 (SFRP2). Since both VEGF and SFRP2 are expressed in breast carcinomas, we hypothesized that tacrolimus would inhibit breast carcinoma growth. Using IHC (IHC) with antibodies to FKBP12 on breast carcinomas we found that FKBP12 localizes to breast tumor vasculature. Treatment of MMTV-neu transgenic mice with tacrolimus (3 mg/kg i.p. daily) (n = 19) resulted in a 73% reduction in the growth rate for tacrolimus treated mice compared to control (n = 15), p = 0.003; which was associated with an 82% reduction in tumor microvascular density (p,0.001) by IHC. Tacrolimus (1 mM) inhibited SFRP2 induced endothelial tube formation by 71% (p = 0.005) and inhibited VEGF induced endothelial tube formation by 67% (p = 0.004). To show that NFATc3 is required for SFRP2 stimulated angiogenesis, NFATc3 was silenced with shRNA in endothelial cells. Sham transfected cells responded to SFRP2 stimulation in a tube formation assay with an increase in the number of branch points (p,0.003), however, cells transfected with shRNA to NFATc3 showed no increase in tube formation in response to SFRP2. This demonstrates that NFATc3 is required for SFRP2 induced tube formation, and tacrolimus inhibits angiogenesis in vitro and breast carcinoma growth in vivo. This provides a rationale for examining the therapeutic potential of tacrolimus at inhibiting breast carcinoma growth in humans. Citation: Siamakpour-Reihani S, Caster J, Bandhu Nepal D, Courtwright A, Hilliard E, et al. (2011) The Role of Calcineurin/NFAT in SFRP2 Induced Angiogenesis-A Rationale for Breast Cancer Treatment with the Calcineurin Inhibitor Tacrolimus. PLoS ONE 6(6): e20412.

Journal of the American College of Surgeons, 2008

block proliferation of cancer cells. The object of our approach was to identify domains from the ... more block proliferation of cancer cells. The object of our approach was to identify domains from the p53 protein that possess anti-cancer activity. We accomplished this by synthesizing peptides corresponding to the hdm-2-binding domain (residues 12-26) and linked them to a trans-membrane-penetrating sequence. The anti-cancer activity of one such peptide designated PNC-27 was then tested against human pancreatic cancer cells and the mechanism studied. METHODS: MiaPaCa-2 human pancreatic carcinoma cells were treated daily with PNC-27. During this time, we recorded changes in cell morphology and growth characteristics among treated and control groups. Necrosis mediated by peptide was determined by measuring lactate dehydrogenase (LDH) as well as elevation of proapoptotic proteins. Treatment with fluorescent labeled peptide, immunoprecipitation (IP), and time lapse electron microscopy (EM) were employed to elucidate the anti-cancer mechanism.

Molecular Cancer Therapeutics, 2013

Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast can... more Secreted frizzled-related protein 2 (SFRP2) is overexpressed in human angiosarcoma and breast cancer and stimulates angiogenesis via activation of the calcineurin/NFATc3 pathway. There are conflicting reports in the literature as to whether SFRP2 is an antagonist or agonist of b-catenin. The aims of these studies were to assess the effects of SFRP2 antagonism on tumor growth and Wnt-signaling and to evaluate whether SFRP2 is a viable therapeutic target. The antiangiogenic and antitumor properties of SFRP2 monoclonal antibody (mAb) were assessed using in vitro proliferation, migration, tube formation assays, and in vivo angiosarcoma and triplenegative breast cancer models. Wnt-signaling was assessed in endothelial and tumor cells treated with SFRP2 mAb using Western blotting. Pharmacokinetic and biodistribution data were generated in tumor-bearing and nontumor-bearing mice. SFRP2 mAb was shown to induce antitumor and antiangiogenic effects in vitro and inhibit activation of b-catenin and nuclear factor of activated T-cells c3 (NFATc3) in endothelial and tumor cells. Treatment of SVR angiosarcoma allografts in nude mice with the SFRP2 mAb decreased tumor volume by 58% compared with control (P ¼ 0.004). Treatment of MDA-MB-231 breast carcinoma xenografts with SFRP2 mAb decreased tumor volume by 52% (P ¼ 0.03) compared with control, whereas bevacizumab did not significantly reduce tumor volume. Pharmacokinetic studies show the antibody is long circulating in the blood and preferentially accumulates in SFRP2-positive tumors. In conclusion, antagonizing SFRP2 inhibits activation of b-catenin and NFATc3 in endothelial and tumor cells and is a novel therapeutic approach for inhibiting angiosarcoma and triple-negative breast cancer. Mol Cancer Ther; 12(5); 685-95. Ó2013 AACR.