Donald J Buchsbaum

Publications of Donald J Buchsbaum

• A Deimmunized Bispecific Ligand-Directed Toxin That Shows an Impressive Anti-Pancreatic Cancer Effect in a Systemic Nude Mouse Orthotopic Model.

  Authors: Seunguk Oh, Deborah A Todhunter, Angela Panoskaltsis-Mortari, Donald J Buchsbaum, Shoko Toma, Daniel A Vallera

  Pancreas. 01/2012;

  OBJECTIVE: The objective was to test a bispecific ligand-directed toxin (BLT), with reduced immunogenicity for enhanced efficacy in targeting orthotopic pancreatic cancer in vivo. METHOD: A new BLTOBJECTIVE: The objective was to test a bispecific ligand-directed toxin (BLT), with reduced immunogenicity for enhanced efficacy in targeting orthotopic pancreatic cancer in vivo. METHOD: A new BLT was created in which both human epidermal growth factor (EGF) and interleukin 4 cytokines were cloned onto the same single chain molecule with deimmunized pseudomonas exotoxin (dEGF4KDEL). Key amino acids dictating B-cell generation of neutralizing antitoxin antibodies were mutated. Bioassays were used to determine whether mutation reduced potency, and enzyme-linked immunosorbent assay studies were performed to determine whether antitoxin antibodies were reduced. A genetically altered luciferase MIA PaCa-2 xenograft model was used to image in real time and determine effects on systemic malignant human cancer. Bispecific ligand-directed toxins targeting B cells were used as specificity controls. RESULTS: Deimmunized EGF4KDEL was significantly effective after systemic injection against established orthotopic MIA PaCa-2 pancreatic cancer and selectively prevented metastasis. Mutagenesis significantly reduced antitoxin levels in vivo with no apparent activity loss in vitro. The drug was effective against 3 human pancreatic cancer lines in vitro, MIA PaCa-2, SW1990, and S2VP10. CONCLUSIONS: Despite the metastatic nature of the MIA PaCa-2 orthotopic tumor xenografted in nude mice, high percentages of tumors responded to extended dEGFKDEL treatment resulting in significant anticancer effects and disease-free survivors.

• The impact of novel retinoids in combination with platinum chemotherapy on ovarian cancer stem cells.

  Authors: Jenny M Whitworth, Angelina I Londoño-Joshi, Jeffrey C Sellers, Patsy J Oliver, Donald D Muccio, Venkatram R Atigadda, J Michael Straughn, Donald J Buchsbaum

  Gynecologic oncology. 12/2011;

  OBJECTIVE: Retinoids are important modulators of cell growth, differentiation, and proliferation. 9cUAB30, 9cUAB124, and 9cUAB130 are three novel retinoid compounds that show cytotoxic effects inOBJECTIVE: Retinoids are important modulators of cell growth, differentiation, and proliferation. 9cUAB30, 9cUAB124, and 9cUAB130 are three novel retinoid compounds that show cytotoxic effects in other malignancies. We evaluated these novel retinoids in combination with chemotherapy against ovarian cancer stem cells (CSCs) in vitro and in an ex vivo model. METHODS: A2780 cells were plated in 96-well plates and treated with retinoid, carboplatin, or combination therapy. Cell viability was evaluated using ATPLite assay. The A2780 cell line was also analyzed for CSCs by evaluating ALDH activity using flow cytometry. A2780 cells treated ex vivo with retinoids and chemotherapy were injected into the flank of athymic nude mice in order to evaluate subsequent tumor initiating capacity. RESULTS: A2780 cells were sensitive to treatment with retinoids and carboplatin. The best treatment resulted from the combination of retinoid 9cUAB130 and carboplatin. Untreated A2780 cells demonstrated ALDH activity in 3.3% of the cell population. Carboplatin treatment enriched ALDH activity to 27.3%, while 9cUAB130±carboplatin maintained the ALDH positive levels similar to untreated controls (2.3% and 6.7%, respectively). Similar results were found in tumorsphere-forming conditions. Flank injections of ex vivo treated A2780 cells resulted in 4/4 mice developing tumors at 40days in the untreated group, while 0/4 tumors developed in the 9cUAB130 and carboplatin treated group. CONCLUSION: Combination treatment with carboplatin and retinoids reduced cell-viability, reduced CSC marker expression, and inhibited tumorigenicity, making it a more effective treatment when compared with carboplatin alone.

• The use of retinoids in ovarian cancer: a review of the literature.

  Authors: Jenny M Whitworth, J Michael Straughn, Venkatram R Atigadda, Donald D Muccio, Donald J Buchsbaum

  International journal of gynecological cancer : official journal of the International Gynecological Cancer Society. 12/2011; 22(2):191-8.

  Ovarian cancer is the deadliest of all gynecologic malignancies. The search for novel treatment modalities to augment traditional chemotherapy and improve quality of life is ongoing. Retinoids, aOvarian cancer is the deadliest of all gynecologic malignancies. The search for novel treatment modalities to augment traditional chemotherapy and improve quality of life is ongoing. Retinoids, a class of compounds composed of vitamin A, its natural derivatives, and synthetic analogs, have been studied extensively in both the prevention and treatment of gynecologic malignancies. In this article, we reviewed preclinical studies and clinical trials conducted using retinoids in ovarian cancer.

• Basal-like breast cancer stem cells are sensitive to anti-DR5 mediated cytotoxicity.

  Authors: Angelina I Londoño-Joshi, Patsy G Oliver, Yufeng Li, Choo Hyung Lee, Andres Forero-Torres, Albert F Lobuglio, Donald J Buchsbaum

  Breast cancer research and treatment. 09/2011;

  Breast cancer stem cells (BrCSC) are resistant to common therapeutic modalities including chemotherapy, radiation, and hormonal agents. They are thought to contribute to treatment resistance,Breast cancer stem cells (BrCSC) are resistant to common therapeutic modalities including chemotherapy, radiation, and hormonal agents. They are thought to contribute to treatment resistance, relapse, and metastases. This study examines the effect of a monoclonal anti-DR5 antibody (TRA-8) and chemotherapy (adriamycin, taxol) on BrCSC populations from basal-like breast cancer cell lines. Doubly enriched BrCSC (CD44(+), CD24(-), ALDH(+)) cells were exposed to TRA-8 and control reagents and examined for cytotoxicity, caspase activation, tumorsphere formation and tumorigenicity. Doubly enriched BrCSC populations expressed cell surface DR5 and were sensitive to TRA-8 mediated cytotoxicity with induction of caspase 8 and 3 activation. TRA-8 at sub-nanomolar concentrations inhibited 2LMP and SUM159 BrCSC tumorsphere formation and was more than 50-fold more inhibitory than TRAIL or anti-DR4 at equimolar concentrations. Chemotherapy treatment of 2LMP and SUM159 cell lines resulted in a relative increase of BrCSC, whereas TRA-8 produced a decrease in the percentage of BrCSC. TRA-8 exposure to 2LMP and SUM159 BrCSC preparations produced significant inhibition of tumorigenicity. DR5 maybe a therapeutic target on the surface of basal-like BrCSC which is amenable to agonistic monoclonal anti-DR5 therapy.

• Effect of anti-DR5 and chemotherapy on basal-like breast cancer.

  Authors: Patsy G Oliver, Albert F Lobuglio, Tong Zhou, Andres Forero, Hyunki Kim, Kurt R Zinn, Guihua Zhai, Yufeng Li, Choo H Lee, Donald J Buchsbaum

  Breast cancer research and treatment. 09/2011;

  The purpose is to evaluate sensitivity of basal-like breast cancer to treatment with anti-DR5 alone and in combination with chemotherapy. Cytotoxicity of TRA-8 anti-DR5 alone and in combination withThe purpose is to evaluate sensitivity of basal-like breast cancer to treatment with anti-DR5 alone and in combination with chemotherapy. Cytotoxicity of TRA-8 anti-DR5 alone and in combination with doxorubicin or paclitaxel was examined. The role of a DR5-associated molecule (DDX3) in the regulation of apoptosis by recruitment of cIAP1 to the DR5/DDX3 complex was studied. SUM159 and 2LMP orthotopic xenografts were treated with TRA-8 alone and in combination with Abraxane or doxorubicin, and tumor growth inhibition determined. Diffusion-weighted magnetic resonance imaging was used to monitor early tumor response. The majority (12/15) of basal-like cell lines were very sensitive to TRA-8-induced cytotoxicity (IC(50) values of 1.0-49 ng/ml). In contrast, 8/11 luminal or HER2-positive cell lines were resistant (IC(50) > 1,000 ng/ml). Enhanced killing of basal-like cell lines was produced by combination treatment with TRA-8 and doxorubicin. Majority of basal cell lines expressed lower levels of DR5-associated DDX3 and cIAP1 than luminal and HER2-positive cell lines. TRA-8 inhibited growth of basal xenografts and produced 20% complete 2LMP tumor regressions. TRA-8 and chemotherapy produced greater 2LMP growth inhibition than either alone. An increase in apparent diffusion coefficient in 2LMP tumors was measured in a week of therapy with TRA-8 and Abraxane. Basal-like cell lines were more sensitive to TRA-8-mediated cytotoxicity than HER2-over-expressing and luminal cell lines, and chemotherapy enhanced cytotoxicity. High sensitivity of basal cells to TRA-8 correlated with low expression of DR5/DDX3/cIAP1 complex. Treatment with TRA-8 and chemotherapy may be an effective therapy for basal-like breast cancer.

• Relationship between galectin-3 expression and TRAIL sensitivity in breast cancer.

  Authors: Hope M Amm, Donald J Buchsbaum

  Expert review of anticancer therapy. 08/2011; 11(8):1193-6.

  Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) binds to death receptors expressed on cancer cells and induces apoptosis. Triple-negative breast cancer cell lines are more sensitiveTumor necrosis factor-related apoptosis-inducing ligand (TRAIL) binds to death receptors expressed on cancer cells and induces apoptosis. Triple-negative breast cancer cell lines are more sensitive to TRAIL or TRAIL-death receptor agonistic monoclonal antibody-induced apoptosis compared with HER-2/neu-overexpressing or luminal cell lines. The paper under evaluation sought to determine whether the His64/Pro64 polymorphism of galectin-3, which is associated with breast cancer incidence, affects sensitivity to TRAIL. None of five breast cancer cell lines homozygous for Pro64 galectin-3 were sensitive to TRAIL, but two out of two homozygous His64 cell lines and one out of two heterozygous His64 cell lines were sensitive. Transfection of galectin-3 null BT549 breast cancer cells with His64 galectin-3 rendered them sensitive to TRAIL, while Pro64 galectin-3-transfected cells remained resistant to TRAIL. This article highlights that galectin-3 receptor expression and genotype may be useful markers in predicting TRAIL or agonistic antibody sensitivity of breast cancer patients.

• Treatment of small cell lung cancer with TRA-8 in combination with cisplatin and radiation.

  Authors: James A Bonner, Christopher D Willey, Eddy S Yang, Michael C Dobelbower, Leisa L Sanford, Sheila J Bright, Donald J Buchsbaum, Kevin P Raisch

  Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 06/2011; 101(1):183-9.

  Limited stage small cell lung cancer (SCLC) represents a minority of SCLC. Despite extensive clinical trials, standard treatment remains cisplatin-based chemotherapy and thoracic irradiation (TI).Limited stage small cell lung cancer (SCLC) represents a minority of SCLC. Despite extensive clinical trials, standard treatment remains cisplatin-based chemotherapy and thoracic irradiation (TI). This study focused on the interaction of cisplatin/radiation with the anti-human DR5 monoclonal antibody TRA-8 in SCLC cells. TRA-8 binds specifically to DR5 and has been shown to activate apoptosis. Four human SCLC cell lines were utilized for experimentation (SCLC-41, SCLC-58, SCLC-68, and SCLC-74). Immunoblot analysis was used to determine relative protein levels of DR5, DR4 and pro-caspase 8 for each cell line. Using a tetrazolium-based assay (XTT), the IC(50) values for cisplatin with or without TRA-8 were determined for the SCLC cell lines. Four SCLC lines were assayed with a combination of TRA-8 (10 μg/ml), 2 Gy radiation and various concentrations of cisplatin. Apoptosis was evaluated using Annexin V-FITC and cleaved caspase immunoblotting. Using a SCLC-58 subcutaneous xenograft model, treatment began 21 d after tumor cell injection. Treatment included weekly cisplatin (4 mg/kg) and radiation of 1 Gy (24 h after cisplatin) and TRA-8 (200 μg) was administered i.p. twice weekly for three weeks. Immunoblot analysis showed similar levels of DR5 for all cell lines with variable levels of DR4. Various concentrations of TRA-8 antibody (≤ 10 μg/ml) induced no significant cytotoxicity in the SCLC cell lines. The in vitro combination treatment with TRA-8 (10 μg/ml), 1.25 μg/ml cisplatin and 2 Gy radiation showed increased cytotoxicity when compared to combinations without TRA-8. Furthermore, the triple combination demonstrated the greatest amount of apoptosis as measured by Annexin V staining. The in vivo studies showed the combination of 1G y, cisplatin and TRA-8 extended the tumor doubling time to 44 d as compared to any doublet treatment groups that ranged from 12 to 20 d. Analysis of survival data showed 100% of the combination group (RT+cisplatin+TRA-8) were alive 65 d after treatment began whereas all doublet treatment groups showed 50% or less survival. These studies showed increased cytotoxicity when TRA-8 was added to radiation/cisplatin in SCLC. This effect was demonstrated in vitro and in vivo. TRA-8 represents a promising new agent in the treatment of SCLC.

• Early therapy evaluation of combined cetuximab and irinotecan in orthotopic pancreatic tumor xenografts by dynamic contrast-enhanced magnetic resonance imaging.

  Authors: Hyunki Kim, Karri D Folks, Lingling Guo, Jeffery C Sellers, Naomi S Fineberg, Cecil R Stockard, William E Grizzle, Donald J Buchsbaum, Desiree E Morgan, James F George, Kurt R Zinn

  Molecular imaging. 06/2011; 10(3):153-67.

  Early pancreatic cancer response following cetuximab and/or irinotecan therapies was measured by serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and during therapy.Early pancreatic cancer response following cetuximab and/or irinotecan therapies was measured by serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and during therapy. Groups 1 to 4 (n  =  6/group) of SCID mice bearing orthotopic pancreatic adenocarcinoma xenografts expressing luciferase were treated with phosphate-buffered saline, cetuximab, irinotecan, or cetuximab combined with irinotecan, respectively, twice weekly for 3 weeks. DCE-MRI was performed on days 0, 1, 2, and 3 after therapy initiation, whereas anatomic magnetic resonance imaging was performed on days 0, 1, 2, 3, 6, and 13. Bioluminescence imaging was performed on days 0 and 21. At day 21, all tumors were collected for further histologic analyses (Ki-67 and CD31 staining), whereas tumor dimensions were measured by calipers. The Ktrans values in the 0.5 mm-thick peripheral tumor region were calculated, and the changes in Ktrans during the 3 days posttherapy were compared to tumor volume changes, bioluminescent signal changes, and histologic findings. The Ktrans changes in the peripheral tumor region after 3 days of therapy were linearly correlated with 21-day decreases in tumor volume (p < .001), bioluminescent signal (p  =  .050), microvessel densities (p  =  .002), and proliferating cell densities (p  =  .001). This study supports the clinical use of DCE-MRI for pancreatic cancer patients for early assessment of an anti-epidermal growth factor receptor therapy combined with chemotherapy.

• Combined modality therapy with TRAIL or agonistic death receptor antibodies.

  Authors: Hope M Amm, Patsy G Oliver, Choo Hyung Lee, Yufeng Li, Donald J Buchsbaum

  Cancer biology & therapy. 03/2011; 11(5):431-49.

  Molecularly targeted therapies, such as antibodies and small molecule inhibitors have emerged as an important breakthrough in the treatment of many human cancers. One targeted therapy underMolecularly targeted therapies, such as antibodies and small molecule inhibitors have emerged as an important breakthrough in the treatment of many human cancers. One targeted therapy under development is tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) due to its ability to induce apoptosis in a variety of human cancer cell lines and xenografts, while lacking toxicity in most normal cells. TRAIL and apoptosis-inducing agonistic antibodies to the TRAIL death receptors have been the subject of many preclinical and clinical studies in the past decade. However, the sensitivity of individual cancer cell lines of a particular tumor type to these agents varies from highly sensitive to resistant. Various chemotherapy agents have been shown to enhance the apoptosis-inducing capacity of TRAIL receptor-targeted therapies and induce sensitization of TRAIL-resistant cells. This review provides an overview of the mechanisms associated with chemotherapy enhancement of TRAIL receptor-targeted therapies including modulation of the apoptotic (death receptor expression, FLIP, and Bcl-2 or inhibitors of apoptosis (IAP) families) as well as cell signaling (NFκB, Akt, p53) pathways. These mechanisms will be important in establishing effective combinations to pursue clinically and in determining relevant targets for future cancer therapies.

• Mechanisms of drug sensitization to TRA-8, an agonistic death receptor 5 antibody, involve modulation of the intrinsic apoptotic pathway in human breast cancer cells.

  Authors: Hope M Amm, Tong Zhou, Adam D Steg, Huichien Kuo, Yufeng Li, Donald J Buchsbaum

  Molecular cancer research : MCR. 02/2011; 9(4):403-17.

  TRA-8, a monoclonal antibody to death receptor 5 induces apoptosis in various cancer cells; however, the degree of sensitivity varies from highly sensitive to resistant. We have previously shown thatTRA-8, a monoclonal antibody to death receptor 5 induces apoptosis in various cancer cells; however, the degree of sensitivity varies from highly sensitive to resistant. We have previously shown that resistance to TRA-8 can be reversed by using chemotherapeutic agents, but the mechanism underlying this sensitization was not fully understood. Here, we examined the combination of TRA-8 with doxorubicin or bortezomib in breast cancer cells. In TRA-8-resistant BT-474 and T47D cells, both chemotherapy agents synergistically sensitized cells to TRA-8 cytotoxicity with enhanced activation of apoptosis shown by cleavage of caspases and PARP, reduced Bid, increased proapoptotic Bcl-2 proteins, and increased mitochondrial membrane depolarization. Doxorubicin or bortezomib combined with TRA-8 also reduced Bcl-XL and X-linked inhibitors of apoptosis (XIAP) in treated cells. Furthermore, targeting these proteins with pharmacologic modulators, AT-101, BH3I-2' and AT-406, produced sensitization to TRA-8. TRA-8 combined with AT-101 or BH3I-2', inhibitors of antiapoptotic Bcl-2 proteins, produced synergistic cytotoxicity against ZR-75-1, BT-474, and T47D cells. The IAP-targeting compound, AT-406, was synergistic with TRA-8 in BT-474 cells, and to a lesser extent T47D cells. Activation of the intrinsic apoptotic pathway was a common mechanism associated with sensitization of TRA-8-resistant breast cancer cell lines. Collectively, these studies show that the Bcl-2 and IAP families of proteins are involved in TRA-8 and chemotherapy resistance via their modulation of the intrinsic apoptotic pathway. Targeting these proteins with novel agents sensitized TRA-8-resistant breast cancer cells, suggesting this approach may represent a potent therapeutic strategy in the treatment of breast cancer.

• Cellular model of Warburg effect identifies tumor promoting function of UCP2 in breast cancer and its suppression by genipin.

  Authors: Vanniarajan Ayyasamy, Kjerstin M Owens, Mohamed Mokhtar Desouki, Ping Liang, Andrei Bakin, Kumarasamy Thangaraj, Donald J Buchsbaum, Albert F LoBuglio, Keshav K Singh

  PloS one. 01/2011; 6(9):e24792.

  The Warburg Effect is characterized by an irreversible injury to mitochondrial oxidative phosphorylation (OXPHOS) and an increased rate of aerobic glycolysis. In this study, we utilized a breastThe Warburg Effect is characterized by an irreversible injury to mitochondrial oxidative phosphorylation (OXPHOS) and an increased rate of aerobic glycolysis. In this study, we utilized a breast epithelial cell line lacking mitochondrial DNA (rho(0)) that exhibits the Warburg Effect associated with breast cancer. We developed a MitoExpress array for rapid analysis of all known nuclear genes encoding the mitochondrial proteome. The gene-expression pattern was compared among a normal breast epithelial cell line, its rho(0) derivative, breast cancer cell lines and primary breast tumors. Among several genes, our study revealed that over-expression of mitochondrial uncoupling protein UCP2 in rho(0) breast epithelial cells reflects gene expression changes in breast cancer cell lines and in primary breast tumors. Furthermore, over-expression of UCP2 was also found in leukemia, ovarian, bladder, esophagus, testicular, colorectal, kidney, pancreatic, lung and prostate tumors. Ectopic expression of UCP2 in MCF7 breast cancer cells led to a decreased mitochondrial membrane potential and increased tumorigenic properties as measured by cell migration, in vitro invasion and anchorage independent growth. Consistent with in vitro studies, we demonstrate that UCP2 over-expression leads to development of tumors in vivo in an orthotopic model of breast cancer. Genipin, a plant derived small molecule, suppressed the UCP2 led tumorigenic properties, which were mediated by decreased reactive oxygen species and down-regulation of UCP2. However, UCP1, 3, 4 and 5 gene expression was unaffected. UCP2 transcription was controlled by SMAD4. Together, these studies suggest a tumor-promoting function of UCP2 in breast cancer. In summary, our studies demonstrate that i) the Warburg Effect is mediated by UCP2; ii) UCP2 is over-expressed in breast and many other cancers; iii) UCP2 promotes tumorigenic properties in vitro and in vivo and iv) genipin suppresses the tumor promoting function of UCP2.

• Anti-tumor activity of an anti-DR5 monoclonal antibody, TRA-8, in combination with taxane/platinum-based chemotherapy in an ovarian cancer model.

  Authors: Kerri S Bevis, Lacey R McNally, Jeffery C Sellers, Deborah Della Manna, Angelina Londoño Joshi, Hope Amm, J Michael Straughn, Donald J Buchsbaum

  Gynecologic oncology. 01/2011; 121(1):193-9.

  Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediates apoptosis via binding to death receptors and enhances the anti-tumor effect of conventional cancer therapies. We evaluated theTumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediates apoptosis via binding to death receptors and enhances the anti-tumor effect of conventional cancer therapies. We evaluated the efficacy of TRA-8, an agonistic antibody to DR5, combined with docetaxel and carboplatin in vitro in an intraperitoneal (IP) ovarian cancer model. Luciferase positive ES2 cells (ES2H) were treated in 96 well plates with TRA-8, carboplatin, docetaxel, and combination therapy. Cell viability was assessed using ATP-lite assay. Apoptosis was confirmed via Western blot analysis. ES2H cells were injected IP into female athymic nude mice. Animals were sorted based on bioluminescent signal with the following treatments: 1) untreated; 2) TRA-8 alone; 3) docetaxel+carboplatin; and 4) docetaxel+carboplatin+TRA-8. Animals receiving TRA-8 antibody were injected IP with 200 μg of TRA-8 twice weekly until death. Animals receiving docetaxel+carboplatin were injected IP with 5mg/kg and 15 mg/kg respectively every 3 weeks until death. Animals were assessed for tumor burden using bioluminescence imaging and overall survival. Combination therapy reduced viability of ES2H cells in vitro over single agent therapy. Tumor burden was lowest in the chemotherapy+TRA-8 group at days 23 (p<0.001) and 30 (p = 0.04). Mean survival was greatest in the chemotherapy+TRA-8 group (41 days) compared to the chemotherapy only group (34 days) and control group (27 days) as determined by Kaplan-Meier analysis (p<0.001). Conventional chemotherapy combined with TRA-8 reduced cell-viability via activation of apoptotic pathways, reduced tumor burden and improved survival in this ovarian cancer model.

• KISS1 over-expression suppresses metastasis of pancreatic adenocarcinoma in a xenograft mouse model.

  Authors: Lacey R McNally, Danny R Welch, Benjamin H Beck, Lewis J Stafford, Joshua W Long, Jeffery C Sellers, Zhi Q Huang, William E Grizzle, Cecil R Stockard, Kevin T Nash, Donald J Buchsbaum

  Clinical & experimental metastasis. 12/2010; 27(8):591-600.

  Identifying molecular targets for treatment of pancreatic cancer metastasis is critical due to the high frequency of dissemination prior to diagnosis of this lethal disease. Because the KISS1Identifying molecular targets for treatment of pancreatic cancer metastasis is critical due to the high frequency of dissemination prior to diagnosis of this lethal disease. Because the KISS1 metastasis suppressor is expressed at reduced levels in advanced pancreatic cancer, we hypothesized that re-expression of KISS1 would reduce metastases. Highly metastatic S2VP10 cells expressing luciferase (S2VP10L) were transfected with a FLAG-tagged version of KISS1 (KFM), KFMΔSS (with deleted secretion signal sequence), or pcDNA3 control plasmid (CP) and expression was confirmed by RTQ-PCR. SCID mice were implanted orthotopically with S2VP10L cells or transfectants and tumor growth and metastases were monitored using bioluminescence imaging. Mice with S2VP10L-KISS1 tumors developed fewer liver (98%) and lung (99%) metastases than S2VP10L. Unexpectedly, mice with S2VP10L-KFMΔSS tumors also had reduced liver and lung metastases, but had more metastases than mice with S2VP10L-KISS. KISS1 protein was found in the cytoplasm of both KFMΔSS and KISS1-expressing orthotopic tumors by immunohistochemistry. Metastases were not found in lungs of mice with S2VP10L-KISS1 tumors; whereas, KFMΔSS lung sections had regions of concentrated KISS1 staining, suggesting that secretion of KISS1 is needed to reduce metastasis significantly. These data suggest induction of KISS1 expression has potential as an adjuvant treatment for pancreatic cancer.

• Overcoming TRAIL resistance in ovarian carcinoma.

  Authors: Kerri S Bevis, Donald J Buchsbaum, J Michael Straughn

  Gynecologic oncology. 10/2010; 119(1):157-63.

  Ovarian cancer, the deadliest of the gynecologic malignancies, poses a therapeutic challenge because of the 70% recurrence rate among patients treated with taxane/platinum-based chemotherapy. TumorOvarian cancer, the deadliest of the gynecologic malignancies, poses a therapeutic challenge because of the 70% recurrence rate among patients treated with taxane/platinum-based chemotherapy. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anti-cancer therapy due to its ability to selectively induce apoptosis in cancer cells with little toxicity to normal cells. Despite initially promising results from early TRAIL studies in ovarian cancer, reports of significant TRAIL resistance soon followed. The current study reviews strategies to overcome TRAIL resistance in ovarian cancer. PubMed was searched for published literature in English using key words "TRAIL," "ovarian," "death receptor" and "resistance". The references of identified articles were then searched for further related literature. A number of mechanisms underlying TRAIL resistance have been proposed, including absence of death receptor expression and genetic alterations, leading to silencing of the downstream effects of ligand binding. Numerous strategies to overcome these mechanisms have been investigated, including combination treatment with cytotoxic chemotherapy, retinoids, proteasome inhibitors, demethylating agents, Akt inhibitors and EGFR inhibitors. Many of the combination treatments have demonstrated success at restoring TRAIL sensitivity in preclinical studies. Continued efforts with combination therapy designed to target multiple steps in apoptotic pathways may not only improve the efficacy of TRAIL-mediated therapies, but may also improve quality of life for ovarian cancer patients by reducing toxicity associated with cancer therapy.

• DCE-MRI detects early vascular response in breast tumor xenografts following anti-DR5 therapy.

  Authors: Hyunki Kim, Karri D Folks, Lingling Guo, Cecil R Stockard, Naomi S Fineberg, William E Grizzle, James F George, Donald J Buchsbaum, Desiree E Morgan, Kurt R Zinn

  Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging. 04/2010; 13(1):94-103.

  Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measured the early vascular changes after administration of TRA-8, bevacizumab, or TRA-8 combined with bevacizumab in breast tumorDynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measured the early vascular changes after administration of TRA-8, bevacizumab, or TRA-8 combined with bevacizumab in breast tumor xenografts. Groups 1-4 of nude mice bearing human breast carcinoma were injected with phosphate-buffered saline, TRA-8, bevacizumab, and TRA-8 + bevacizumab on day 0, respectively. DCE-MRI was performed on days 0, 1, 2, and 3, and thereafter tumors were collected for terminal deoxynucleotidyl transferase-mediated dUT nick end labeling and CD31 staining. DCE-MRI measured a significant K (trans) change within 3 days after TRA-8 therapy that correlated with tumor growth arrest, which was not shown with statistical significance by histopathology at these early time points posttreatment. The K (trans) changes followed quadratic polynomial curves. DCE-MRI detected significantly lower K (trans) levels in breast tumor xenografts following TRA-8 monotherapy or combined therapy with bevacizumab.

• A new drug delivery method of bispecific ligand-directed toxins, which reduces toxicity and promotes efficacy in a model of orthotopic pancreatic cancer.

  Authors: Seunguk Oh, Brad J Stish, Selwyn M Vickers, Donald J Buchsbaum, Ashok K Saluja, Daniel A Vallera

  Pancreas. 02/2010; 39(6):913-22.

  Biologicals targeting epidermal growth factor (EGF) and interleukin 13 receptors not only react with overexpressed markers on cancer cells but also react with receptors on normal cells. Because weBiologicals targeting epidermal growth factor (EGF) and interleukin 13 receptors not only react with overexpressed markers on cancer cells but also react with receptors on normal cells. Because we developed novel bispecific ligand-directed toxins synthesized by cloning EGF and interleukin 13 on the same molecule with toxin, our objective was to determine whether we could block normal receptors while still targeting receptors overexpressed on cancer cells, thereby decreasing toxicity while maintaining efficacy. A method, toxicity blocking (ToxBloc), was developed in which a bolus intraperitoneal dose of recombinant EGF13 (without toxin) was given to mice approximately 15 to 20 minutes before DTEGF13. Experiments were then performed to determine whether the maximal tolerated dose (MTD) was reduced and whether we were still able to eliminate progression of aggressive human, metastatic, pancreatic cancer induced by orthotopic injection (OT) in nude mice. ToxBloc permitted us to safely exceed the DTEGF13 maximal tolerated dose by 15-fold. This approach permitted repetitive high dosing with the bispecific ligand-directed toxin resulting in tumor regression (P < 0.01). Tumor effects were documented using a tumor imaging model in which OT tumor growth was monitored noninvasively in real time. ToxBloc was selective because other bispecific peptides did not block. ToxBloc represents a new method of drug delivery and a potential solution to the problem of toxicity.

• Experimental cancer therapy using restoration of NAD+ -linked 15-hydroxyprostaglandin dehydrogenase expression.

  Authors: Lyudmila N Kaliberova, Sergei A Kusmartsev, Valentina Krendelchtchikova, Cecil R Stockard, William E Grizzle, Donald J Buchsbaum, Sergey A Kaliberov

  Molecular cancer therapeutics. 11/2009; 8(11):3130-9.

  Preclinical and clinical evidence shows that cyclooxygenase-2 (Cox-2)-mediated prostaglandin E(2) (PGE(2)) overexpression plays an important role in tumor growth, metastasis, and immunosuppression.Preclinical and clinical evidence shows that cyclooxygenase-2 (Cox-2)-mediated prostaglandin E(2) (PGE(2)) overexpression plays an important role in tumor growth, metastasis, and immunosuppression. It has been shown that expression of NAD(+)-linked 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a key enzyme responsible for PGE(2) inactivation, is suppressed in the majority of cancers, including breast and colon carcinoma. We have developed adenoviral vectors (Ad) encoding the 15-PGDH gene under control of the vascular endothelial growth factor receptor 1 (VEGFR1/flt-1; Adflt-PGDH) and the Cox-2 (Adcox-PGDH) promoters. The purpose of this study was to investigate cytotoxicity in vitro and therapeutic efficacy in vivo of 15-PGDH-mediated cancer therapy. The levels of PGE(2) and VEGF expression were correlated with PGE(2) receptor and Cox-2 and flt-1 expression in cancer cells. The in vitro study showed that Ad-mediated 15-PGDH expression significantly decreased proliferation and migration of cancer cells. Animal breast and colon tumor therapy studies showed that 15-PGDH gene therapy produced a significant delay in 2LMP and LS174T tumor growth. Combined therapy using 15-PGDH and anti-VEGF antibody (bevacizumab) significantly increased inhibition of growth of LS174T tumor xenografts in comparison with agents alone. These results suggest that 15-PGDH-mediated regulation of PGE(2) catabolism in the tumor microenvironment represents a novel approach for therapy of human breast and colon cancer.

• Anti-EMMPRIN monoclonal antibody as a novel agent for therapy of head and neck cancer.

  Authors: Nichole R Dean, J Robert Newman, Emily E Helman, Wenyue Zhang, Seena Safavy, D M Weeks, Mark Cunningham, Linda A Snyder, Yi Tang, Li Yan, Lacey R McNally, Donald J Buchsbaum, Eben L Rosenthal

  Clinical cancer research : an official journal of the American Association for Cancer Research. 07/2009; 15(12):4058-65.

  PURPOSE: Extracellular matrix metalloprotease inducer (EMMPRIN) is a tumor surface protein that promotes growth and is overexpressed in head and neck cancer. These features make it a potentialPURPOSE: Extracellular matrix metalloprotease inducer (EMMPRIN) is a tumor surface protein that promotes growth and is overexpressed in head and neck cancer. These features make it a potential therapeutic target for monoclonal antibody (mAb)-based therapy. Because molecular therapy is considered more effective when delivered with conventional cytotoxic agents, anti-EMMPRIN therapy was assessed alone and in combination with external beam radiation. EXPERIMENTAL DESIGN: Using a murine flank model, loss of EMMPRIN function was achieved by transfection with a small interfering RNA against EMMPRIN or treatment with a chimeric anti-EMMPRIN blocking mAb. Cytokine expression was assessed for xenografts, tumor cells, fibroblasts, and endothelial cells. RESULTS: Animals treated with anti-EMMPRIN mAb had delayed tumor growth compared with untreated controls, whereas treatment with combination radiation and anti-EMMPRIN mAb showed the greatest reduction in tumor growth (P = 0.001). Radiation-treated EMMPRIN knockdown xenografts showed a reduction in tumor growth compared with untreated knockdown controls (P = 0.01), whereas radiation-treated EMMPRIN-expressing xenografts did not show a delay in tumor growth. Immunohistochemical evaluation for Ki67 and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) resulted in a reduction in proliferation (P = 0.007) and increased apoptosis in anti-EMMPRIN mAb-treated xenografts compared with untreated controls (P = 0.087). In addition, we provide evidence that EMMPRIN suppression results in decreased interleukin 1beta (IL-1beta), IL-6, and IL-8 cytokine production, in vitro and in vivo. CONCLUSIONS: These data suggest that anti-EMMPRIN antibody inhibits tumor cell proliferation in vivo and may represent a novel targeted treatment option in head and neck squamous cell carcinoma.

• Preclinical studies and clinical utilization of monoclonal antibodies in epithelial ovarian cancer.

  Authors: Peter J Frederick, J Michael Straughn, Ronald D Alvarez, Donald J Buchsbaum

  Gynecologic oncology. 03/2009;

  OBJECTIVE: To present an overview of selected monoclonal antibodies (mAbs) that have been studied in epithelial ovarian cancer with a focus on combination treatment with conventional chemotherapy.OBJECTIVE: To present an overview of selected monoclonal antibodies (mAbs) that have been studied in epithelial ovarian cancer with a focus on combination treatment with conventional chemotherapy. METHODS: The authors perform a narrative review of the literature. Preclinical studies that provided rationale for mAb use are examined, and selected clinical trials that evaluated efficacy and tolerability are reviewed. RESULTS: Numerous mAbs have been utilized in epithelial ovarian cancer, including bevacizumab (anti-vascular endothelial growth factor), trastuzumab (anti-human epidermal growth factor-2), cetuximab (anti-epidermal growth factor receptor), and oregovomab (anti-CA125). Favorable preclinical results have lead to the development of a number of clinical trials. Side-effects have been minimal and combination therapy has been well-tolerated. Efficacy has been variable in the clinical trials. CONCLUSIONS: Targeted treatment with mAbs in conjunction with cytotoxic chemotherapy has been an important research area during the last decade. This therapeutic approach holds promise for improved outcomes in patients with ovarian cancer.

• Monoclonal antibodies in the treatment of pancreatic cancer.

  Authors: Zhi-Qiang Huang, Donald J Buchsbaum

  Immunotherapy. 03/2009; 1(2):223-9.

  Human pancreatic cancer is a malignant disease with almost equal incidence and mortality. Effective diagnostic and therapeutic strategies are still urgently needed to improve its survival rate. WithHuman pancreatic cancer is a malignant disease with almost equal incidence and mortality. Effective diagnostic and therapeutic strategies are still urgently needed to improve its survival rate. With advances in structural and functional genomics, recent work has focused on targeted molecular therapy using monoclonal antibodies. This review summarizes the target molecules on the tumor cell surface and normal tissue stroma, which are related to pancreatic cancer oncogenesis, tumor growth or resistance to chemotherapy, as well as molecules involved in regulating inflammation and host immunoresponses. Targeted molecules include cell-surface receptors, such as the EGF receptor, HER2, death receptor 5 and IGF-1 receptor. Effects of monoclonal antibodies against these target molecules alone or in combination with chemotherapy, small-molecule signal transduction inhibitors, or radiation therapy are also discussed. Also discussed are the use of toxin or radioisotope conjugates, and information relating to the use of these targeting agents in pancreatic cancer clinical trials. Although targeted molecular therapy with monoclonal antibodies has made some progress in pancreatic cancer treatment, especially in preclinical studies, its clinical application to improve the survival rate of pancreatic cancer patients requires further investigation.