Antibody responses of variable lymphocyte receptors in the lamprey.

Lamprey and hagfish, the living representatives of jawless vertebrates, use genomic leucine-rich-repeat cassettes for the combinatorial assembly of diverse antigen receptor genes encoding variable lymphocyte receptors of two types: VLRA and VLRB. We describe here the VLRB-bearing lineage of lymphocytes in sea lamprey. These cells responded to repetitive carbohydrate or protein determinants on bacteria or mammalian cells with lymphoblastoid transformation, proliferation and differentiation into plasmacytes that secreted multimeric antigen-specific VLRB antibodies. Lacking a thymus and the ability to respond to soluble protein antigens, lampreys seem to have evolved a B cell-like system for adaptive humoral responses.

Lung resistance-related protein (LRP) expression in malignant ascitic cells as a prognostic marker for advanced ovarian serous carcinoma.

PURPOSE: Ovarian serous carcinoma is an aggressive cancer that often presents with metastatic disease. Although primary tumor and established metastatic foci in the omentum are generally compared to identify proteins involved in drug resistance, we investigated a potential bridge, the malignant cells from ascites, as facilitator of drug resistance and recurrence. METHODS: We evaluated the expression of drug resistance markers P-glycoprotein (P-gp), canalicular multispecific organic anion transporter (MRP2), and lung resistance-related protein (LRP) in malignant cells from ascites and matched omental metastasis from 25 patients with advanced-stage ovarian serous carcinoma who were chemotherapeutic naïve and undergoing initial cytoreductive surgery. Cell viability in vitro, patient response to chemotherapy, and patient survival were correlated with these biomarkers. RESULTS: Of the 25 patients evaluated for a correlation of LRP to 1-year recurrence, we correctly predicted the 1-year recurrence of 24 patients based solely on the presence of LRP in ascitic tumor cells (p=0.01). P-gp and MRP2 were not expressed in malignant cells of ascites or omental metastases. Malignant cells from ascites had higher expression of LRP and were found to be more resistant to carboplatin treatment than cells from omental metastasis (p=0.00375) by in vitro assay. LRP expression in the malignant cells of ascites correlated with carboplatin resistance (p=0.001) by in vitro assay and recurrence at 1 year (p=0.0125). CONCLUSIONS: LRP expression in malignant cells of ascites is a promising marker to predict response to first-line chemotherapy in patients with advanced ovarian serous carcinoma.

Inhibition of the catalytic function of activation-induced cytidine deaminase promotes apoptosis of germinal center B cells in BXD2 mice.

OBJECTIVE: To determine whether functional suppression of the catalytic domain of activation-induced cytidine deaminase (AID) can suppress the hyperreactive germinal center (GC) responses in BXD2 mice. METHODS: We generated transgenic BXD2 mice expressing a dominant-negative (DN) form of Aicda at the somatic hypermutation site (BXD2-Aicda-DN-transgenic mice). Real-time quantitative reverse transcriptase-polymerase chain reaction was used to determine the expression of Aicda and DNA damage/repair genes. Enzyme-linked immunosorbent assay was used to measure serum levels of autoantibodies and immune complexes (ICs). Development of GCs and antibody-containing ICs as well as numbers of proliferative and apoptotic cells were determined using flow cytometry and/or immunohistochemical analyses. Development of arthritis and kidney disease was evaluated histologically in 6-8-month-old mice. RESULTS: Suppression of the somatic hypermutation function of AID resulted in a significant decrease in autoantibody production without affecting the expression of DNA damage-related genes in GC B cells of BXD2-Aicda-DN-transgenic mice. There was decreased proliferation, increased apoptosis, increased expression of caspase 9 messenger RNA in GC B cells, and lower numbers of GCs in the spleens of BXD2-Aicda-DN-transgenic mice. Decreased GC response was associated with lower levels of IgG-containing ICs. Anti-IgM- and anti-CD40 plus anti-Ig-induced B cell proliferative responses were decreased in BXD2-Aicda-DN-transgenic mice. CONCLUSION: Inhibition of the AID somatic hypermutation function in BXD2 mice suppressed development of spontaneous GCs, generation of autoantibody-producing B cells, and autoimmunity in BXD2 mice. Suppression of AID catalytic function to limit selection-based survival of GC B cells could become a novel therapy for the treatment of autoimmune disease.

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

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.

Extracelluar matrix metalloproteinase as a novel target for pancreatic cancer therapy.

The objective of this study was to evaluate extracellular matrix metalloproteinase (EMMPRIN) as a novel target in orthotopic pancreatic cancer murine models. MIA PaCa-2 human pancreatic tumor cells were implanted in groups 1 and 3-7, whereas MIA PaCa-2 EMMPRIN knockdown cells were implanted in group 2. Dosing with anti-EMMPRIN antibody started immediately after implantation for groups 1-3 (residual tumor model) and at 21 days after cell implantation for groups 4-7 (established tumor model). Groups 3, 5, and 7 were treated with anti-EMMRPIN antibody (0.2-1.0 mg) twice weekly for 2-3 weeks, whereas the other groups served as the control. In the residual tumor model, tumor growth of anti-EMMPRIN-treated group was successfully arrested for 21 days (15 ± 4 mm(3)), which was significantly lower than that of the EMMPRIN knockdown group (80 ± 15 mm(3); P=0.001) or the control group (240 ± 41 mm(3); P<0.001). In the established tumor model, anti-EMMPRIN therapy lowered tumor volume increase by approximately 40% compared with the control, regardless of the dose amount. Ki67-expressed cell density of group 5 was 939 ± 150 mm(-2), which was significantly lower than that of group 4 (1709 ± 145 mm(-2); P=0.006). Microvessel density of group 5 (30 ± 6 mm(-2)) was also significantly lower than that of group 4 (53 ± 5 mm(-2); P=0.014), whereas the microvessel size of group 5 (191 ± 22 µm(2)) was significantly larger than that of group 4 (113 ± 26 µm(2); P=0.049). These data show the high potential of anti-EMMPRIN therapy for pancreatic cancer and support its clinical translation.

Pulmonary angiogenesis in a rat model of hepatopulmonary syndrome.

BACKGROUND & AIMS: Hepatopulmonary syndrome (HPS), defined as intrapulmonary vasodilation, occurs in 10%-30% of cirrhotics and increases mortality. In a rat model of HPS induced by common bile duct ligation (CBDL), but not thioacetamide (TAA)-induced nonbiliary cirrhosis, lung capillary density increases, monocytes accumulate in the microvasculature, and signaling factors in the angiogenesis pathway (Akt and endothelial nitric oxide synthase [eNOS]) are activated. Pentoxifylline (PTX) directly decreases lung endothelial Akt and eNOS activation, blocks intravascular monocyte accumulation, and improves experimental HPS; we evaluated whether pulmonary angiogenesis develops in this model. METHODS: TAA- and PTX-treated animals were evaluated following CBDL. Lung angiogenesis was assessed by quantifying factor VIII-positive microvessels and levels of von Willebrand factor (vWf), vascular endothelial cadherin (VE-cadherin), and proliferating cell nuclear antigen (PCNA). Angiogenic factors including phospho-Akt, phospho-eNOS, vascular endothelial growth factor (VEGF)-A, and phospho-VEGF receptor-2 (p-VEGFR-2) were compared and monocyte accumulation was assessed. RESULTS: Following CBDL, but not TAA exposure, rats developed HPS that was temporally correlated with increased numbers of lung microvessel; increased levels of vWf, VE-cadherin and PCNA; and activation of Akt and eNOS. Angiogenesis was accompanied by increased pulmonary VEGF-A and p-VEGFR-2 levels, with VEGF-A staining in accumulated intravascular monocytes and alveolar endothelial cells. Following CBDL, PTX-treated rats had reduced numbers of microvessels, reduced lung monocyte accumulation, downregulation of pulmonary angiogenic factors, and reduced symptoms of HPS. CONCLUSIONS: A specific increase in pulmonary angiogenesis occurs as experimental HPS develops, accompanied by activation of VEGF-A-associated angiogenic pathways. PTX decreases the angiogenesis, reduces the symptoms of HPS, and downregulates VEGF-A mediated pathways.

Effect of TRA-8 anti-death receptor 5 antibody in combination with chemotherapy in an ex vivo human ovarian cancer model.

OBJECTIVES: To investigate the cytotoxicity of TRA-8, an antibody that specifically binds death receptor 5, alone and in combination with chemotherapy, using an ex vivo human ovarian cancer model. MATERIALS AND METHODS: Twenty-six ovarian cancer specimens were obtained during ovarian cancer debulking, and tumor slices were prepared with the Krumdieck tissue slicer. The tumor slices were exposed to varying concentrations of TRA-8, carboplatin/paclitaxel, or the combination of TRA-8 and chemotherapy. Using nonlinear modeling, dose-response curves and IC50 values were generated for specimens treated with TRA-8. The additive and synergistic cytotoxic effects of chemotherapy combination with TRA-8 were evaluated in specimens. In addition to adenosine triphosphate viability assays, the treated and untreated slices were assessed by immunohistochemistry to confirm apoptosis induction. RESULTS: Specimens from 13 patients yielded TRA-8-induced IC50 values. Of these specimens, 15% were found to be sensitive to TRA-8-induced cytotoxicity at IC50 doses less than 500 ng/mL. Specimens from 13 patients underwent combination treatment with TRA-8 and carboplatin/paclitaxel. Of these specimens, 77% exhibited additive cytotoxicity in comparison with those treated with either agent alone, whereas 15% exhibited synergistic cytotoxicity. Immunohistochemical analysis of terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling and cleaved caspase 3 staining demonstrated a dose-dependent increase in apoptosis with the combination treatment. CONCLUSIONS: This study demonstrates the efficacy of the death receptor monoclonal antibody TRA-8 in combination with conventional chemotherapy in an ex vivo human ovarian cancer model. This model can be used to assess cytotoxicity of novel agents in combination with chemotherapy in ovarian cancer.

Human PDE4A8, a novel brain-expressed PDE4 cAMP-specific phosphodiesterase that has undergone rapid evolutionary change.

We have isolated cDNAs encoding PDE4A8 (phosphodiesterase 4 isoform A8), a new human cAMP-specific PDE4 isoform encoded by the PDE4A gene. PDE4A8 has a novel N-terminal region of 85 amino acids that differs from those of the related 'long' PDE4A4, PDE4A10 and PDE4A11 isoforms. The human PDE4A8 N-terminal region has diverged substantially from the corresponding isoforms in the rat and other mammals, consistent with rapid evolutionary change in this region of the protein. When expressed in COS-7 cells, PDE4A8 localized predominantly in the cytosol, but approx. 20% of the enzyme was associated with membrane fractions. Cytosolic PDE4A8 was exquisitely sensitive to inhibition by the prototypical PDE4 inhibitor rolipram (IC(50) of 11+/-1 nM compared with 1600 nM for PDE4A4), but was less sensitive to inhibition by cilomilast (IC(50) of 101+/-7 nM compared with 61 nM for PDE4A4). PDE4A8 mRNA was found to be expressed predominantly in skeletal muscle and brain, a pattern that differs from the tissue expression of other human PDE4 isoforms and also from that of rat PDE4A8. Immunohistochemical analysis showed that PDE4A8 could be detected in discrete regions of human brain, including the cerebellum, spinal cord and cerebral cortex. The unique tissue distribution of PDE4A8, combined with the evolutionary divergence of its N-terminus, suggest that this isoform may have a specific function in regulating cAMP levels in human skeletal muscle and brain.

Breast tumor xenografts: diffusion-weighted MR imaging to assess early therapy with novel apoptosis-inducing anti-DR5 antibody.

PURPOSE: To measure the early therapeutic response to a novel apoptosis-inducing antibody, TRA-8, by using diffusion-weighted magnetic resonance (MR) imaging in a mouse breast cancer model. MATERIALS AND METHODS: Animal experiments had institutional animal care and use committee approval. Four groups of nude mice bearing luciferase-positive breast tumors (four to five mice with eight to 10 tumors per group) were injected intravenously with 0 mg (group 1), 0.025 mg (group 2), 0.100 mg (group 3), or 0.200 mg (group 4) of TRA-8 on days 0 and 3. Diffusion-weighted imaging, anatomic MR imaging, and bioluminescence imaging were performed on days 0, 3, and 6 before dosing. Averaged apparent diffusion coefficients (ADCs) for both whole tumor volume and a 1-mm peripheral tumor shell were calculated and were compared with tumor volume and living tumor cell changes. After imaging at day 6, proliferating and apoptotic cell densities were measured with Ki67 and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling, or TUNEL, staining, respectively, and were compared with cleaved caspase-3 density. RESULTS: The ADC increase at day 3 was dependent on TRA-8 dose level, averaging 6% +/- 3 (standard error of mean), 19% +/- 4, 14% +/- 4, and 34% +/- 7 in the whole tumor volume and 1% +/- 2, 9% +/- 5, 13% +/- 5, and 30% +/- 8 in the outer 1-mm tumor shell only for groups 1, 2, 3, and 4, respectively. The ADC increase in group 4 was significantly higher (P = .0008 and P = .0189 for whole tumor volume and peripheral region, respectively) than that in group 1 on day 3, whereas tumor size did not significantly differ. At day 3, the dose-dependent ADC increases were linearly proportional to apoptotic cell and cleaved caspase-3 densities and were inversely proportional to the density of cells showing Ki67 expression. CONCLUSION: Diffusion-weighted imaging enabled measurement of early breast tumor response to TRA-8 treatment, prior to detectable tumor shrinkage, providing an effective mechanism to noninvasively monitor TRA-8 efficacy. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/248/3/844/DC1.

Anti-tumor activity of the TRA-8 anti-DR5 antibody in combination with cisplatin in an ex vivo human cervical cancer model.

OBJECTIVES: To investigate the cytotoxicity of TRA-8, an antibody that specifically binds death receptor 5 (DR5), alone and in combination with cisplatin, using an ex vivo human cervical cancer model. METHODS: Fifteen cervical cancer specimens were obtained at the time of radical hysterectomy and tumor slices were prepared with the Krumdieck tissue slicer. Tumor slices were exposed to varying concentrations of TRA-8, cisplatin, or the combination of TRA-8 and cisplatin. Using non-linear modeling, dose response curves and IC50 values were generated for each specimen treated with TRA-8. The additive cytotoxic effect of combination treatment was evaluated as well. In addition to ATP viability assays, treated and untreated slices were assessed by immunohistochemistry (IHC) and western blot analysis to confirm apoptosis induction via the extrinsic pathway. RESULTS: Eleven patient specimens yielded TRA-8-induced IC50 values. Sixty-four percent were found to be sensitive to TRA-8-induced cytotoxicity at IC50 doses less than 1000 ng/ml. Seven patient specimens underwent combination treatment with TRA-8 and cisplatin. Of these specimens, 86% exhibited additive cytotoxicity in comparison to treatment with either agent alone. IHC revealed an increase in DR5 expression in tumor slices treated with cisplatin for 24 h. IHC and Western blotting demonstrated TRA-8-induced cell death via apoptosis and activation of caspase 3 and 8. CONCLUSIONS: This study confirms the utility of an ex vivo human cervical cancer model, to evaluate the anti-tumor activity of TRA-8 and cisplatin. This model may be a useful pre-clinical tool to assess cytotoxicity and mechanistic properties of novel agents in cervical cancer.

TRA-8 anti-DR5 monoclonal antibody and gemcitabine induce apoptosis and inhibit radiologically validated orthotopic pancreatic tumor growth.

PURPOSE: To evaluate agonistic TRA-8 monoclonal antibody to human death receptor 5 (DR5) and gemcitabine in vitro and in an orthotopic pancreatic cancer model. EXPERIMENTAL DESIGN: Pancreatic cancer cell lines were screened for DR5 expression, cytotoxicity, and apoptosis induced by TRA-8, gemcitabine, or gemcitabine and TRA-8. An orthotopic model of pancreatic cancer was established in severe combined immunodeficient mice. Mice were treated with TRA-8, gemcitabine, or a combination for one or two cycles of therapy. Tumor growth (ultrasound) and survival were analyzed. RESULTS: All five pancreatic cancer cell lines showed DR5 protein expression and varying sensitivity to TRA-8-mediated cytotoxicity. MIA PaCa-2 cells were very sensitive to TRA-8, moderately resistant to gemcitabine, with additive cytotoxicity to the combination. S2-VP10 cells were resistant to TRA-8 and sensitive to gemcitabine with synergistic sensitivity to the combination. Combination treatment in vitro produced enhanced caspase-3 and caspase-8 activation. A single cycle of therapy produced comparable efficacy for single-agent TRA-8 and the combination of TRA-8 and gemcitabine, with significant reduction in tumor size and prolonged survival compared with gemcitabine alone or control animals. With two cycles of therapy, TRA-8 and combination therapy produced enhanced inhibition of tumor growth compared with single-agent gemcitabine or untreated animals. However, the combination regimen showed enhanced survival as compared with single-agent TRA-8. CONCLUSIONS: Pancreatic cancer cell lines express varying levels of DR5 and differ in their sensitivity to TRA-8 and gemcitabine-induced cytotoxicity. TRA-8 with two cycles of gemcitabine therapy produced the best overall survival.

Age-related increase of tumor susceptibility is associated with myeloid-derived suppressor cell mediated suppression of T cell cytotoxicity in recombinant inbred BXD12 mice.

In this study, our data show that in young BXD12 mice, the implanted TS/A tumor regressed in 4 weeks after implantation, and this regression was associated with extensive T cell infiltration. In contrast, in old BXD12 mice, it was observed that there was rapid tumor growth by 7 weeks. T cell cytotoxicity against TS/A tumor cells exhibited a significant age-related decline, which was correlated with a decline in CD3(+) T cell infiltration of the tumor. Furthermore, the decline of T cell tumor cytotoxicity in aged BXD12 mice was also correlated with the accumulation of CD11b(+)Gr1(+) myeloid-derived suppressor cells in the spleen. Adoptive transfer of these accumulated CD11b(+)Gr1(+)cells from aged mice to 2-month-old BXD12 mice led to the delay of the rejection of implanted tumor cells. The depletion of CD11b(+)Gr1(+)cells from aged BXD12 mice led to the slower growth of tumor. Induction of arginase 1 in myeloid cells isolated from aged mice plays a partial role in immune suppression of T cell cytotoxicity. Thus, the accumulation of immunosuppresssing myeloid cells appears to contribute to the increase of tumor susceptibility as the age of mice increases.

Adeno-associated virus 2-mediated antiangiogenic cancer gene therapy: long-term efficacy of a vector encoding angiostatin and endostatin over vectors encoding a single factor.

Angiogenesis is characteristic of solid tumor growth and a surrogate marker for metastasis in many human cancers. Inhibition of tumor angiogenesis using antiangiogenic drugs and gene transfer approaches has suggested the potential of this form of therapy in controlling tumor growth. However, for long-term tumor-free survival by antiangiogenic therapy, the factors controlling tumor neovasculature need to be systemically maintained at stable therapeutic levels. Here we show sustained expression of the antiangiogenic factors angiostatin and endostatin as secretory proteins by recombinant adeno-associated virus 2 (rAAV)-mediated gene transfer. Both vectors provided significant protective efficacy in a mouse tumor xenograft model. Stable transgene persistence and systemic levels of both angiostatin and endostatin were confirmed by in situ hybridization of the vector-injected tissues and by serum ELISA measurements, respectively. Whereas treatment with rAAV containing either endostatin or angiostatin alone resulted in moderate to significant protection, the combination of endostatin and angiostatin gene transfer from a single vector resulted in a complete protection. These data suggest that AAV-mediated long-term expression of both endostatin and angiostatin may have clinical utility against recurrence of cancers after primary therapies and may represent rational adjuvant therapies in combination with radiation or chemotherapy.

Intravenous delivery of adenovirus-mediated soluble FLT-1 results in liver toxicity.

PURPOSE: Vascular endothelial growth factor (VEGF) is a potent angiogenic agent and plays a major role in tumor growth and metastases. We have previously reported the locoregional (i.p.) delivery of adenovirus-mediated antiangiogenic soluble FLT-1 (sFLT-1; a naturally encoded potent VEGF antagonist) gene therapy to inhibit VEGF action in a murine ovarian carcinoma model. This study was predicated on the fact that systemic delivery of sFLT-1 might allow an approach for therapy of disseminated tumor. The purpose of this study is to test the effects of i.v. delivered, adenovirus-mediated sFLT-1 on the survival duration in a murine ovarian tumor model and to evaluate the safety of i.v.-delivered versus i.p.-delivered adenovirus-mediated sFLT-1 in non-tumor-bearing mice. EXPERIMENTAL DESIGN: To determine the effects of i.v.-administered adenovirus-mediated sFLT-1 on survival duration of mice bearing i.p. human ovarian tumors, an E1A/B-deleted, (replication-deficient) infectivity-enhanced recombinant adenovirus AdRGDGFPsFLT-1 encoding cDNA for both sFLT-1 and GFP (green fluorescent protein), a control adenovirus AdRGDGFP encoding GFP alone, or PBS was delivered i.v. The therapeutic effect of sFLT-1 was evaluated by survival duration of the mice. Furthermore, the safety of i.v.- or i.p.-delivered adenovirus-mediated sFLT-1 was evaluated by administering AdRGDGFPsFLT-1, AdRGDGFP, or PBS either i.v. or i.p. into non-tumor-bearing mice. Adenovirus-mediated gene expression was determined by determining GFP expression using fluorescent microscopy and by assessing sFLT-1 expression in liver, lungs, spleen, and kidneys by immunohistochemistry using anti-FLT-1 monoclonal antibody. Systemic levels of sFLT-1 were evaluated by ELISA and the toxicity was evaluated by histopathology. RESULTS: The i.v. delivery of AdRGDGFPsFLT-1 in the ovarian tumor model resulted in a shorter duration of survival of the mice as compared with the control group. Furthermore, in the safety evaluation experiment, i.v. administration of AdRGDGFPsFLT-1 in non-tumor-bearing mice principally localized to the liver. This localization lead to sFLT-1 overexpression, mainly in the liver, resulting in hemorrhage and tissue toxicity. However, i.p. delivery of AdRGDGFPsFLT-1 did not localize principally to the liver, leading to negligible expression of sFLT-1, and no intrahepatic hemorrhage or toxicity was observed. The i.v. delivery of the control virus AdRGDGFP also principally localized to the liver, leading to GFP expression mainly in the liver. However, neither hemorrhage nor morphological cytotoxicity was observed. i.p. delivery of AdRGDGFP resulted in ectopic localization to the liver with very little GFP expression and no toxicity. These results suggest that overexpression of sFLT-1 in the liver as a result of i.v. delivery is hepatotoxic. CONCLUSIONS: Our results suggest that i.v. delivery of the sFLT-1 gene via replication-deficient, infectivity-enhanced recombinant adenoviral vectors will result in overexpression of sFLT-1 in the liver leading to unacceptable hepatotoxicity. Tumor-specific targeting of the vectors and tumor-specific expression strategies should be used to ensure a clinically useful antiangiogenesis gene therapy.

p53 and erbB-2 are not associated in matched cases of primary and metastatic ovarian carcinomas.

Ovarian cancer has a high mortality rate largely due to the limited number of ovarian carcinomas detected at an early stage. Understanding the molecular changes occurring during the progression of ovarian carcinoma would aid in the development of therapies that may inhibit or target metastasis. Primary and metastatic lesions from 54 and 40 patients with advanced ovarian carcinoma, respectively (including matched primary and metastatic lesions from 30 patients) were evaluated for nuclear accumulation of p53 (clone BP53-12-1) and cytoplasmic and membranous immunostaining of p185 erbB-2 (clone 3B5) by immunohistochemistry. No differences in the immunostaining of p53 and p185erbB-2 (cytoplasm or membrane) were observed between primary and metastatic lesions of the matched cases. Similarly, no differences in the proportion of positive cases of p53 between primary and metastatic lesions of the matched cases was observed. Thus, novel therapies that target p53 or p185erbB-2 can utilize specimens from either primary or metastatic lesions to characterize these targets prior to therapy. Spearman correlations between p53 and p185erbB-2 (cytoplasm or membrane) immunohistochemistry scores were insignificant for the matched cases, all primary lesions, and all metastatic lesions. Also, no significant associations occurred between nuclear accumulation of p53 (positive versus negative) and phenotypic expression of p185erbB-2 (cytoplasm or membrane) immunostaining scores for the matched cases, all primary lesions, and all metastatic lesions. Thus, the nuclear accumulation of p53 and immunostaining of p185erbB-2 in the cytoplasm or on the cellular membranes are independent.

Expression of CEA, Tag-72, and Lewis-Y antigen in primary and metastatic lesions of ovarian carcinoma.

Ovarian carcinoma has a high mortality rate, because most ovarian carcinomas are detected at a late stage. Traditional therapies, such as surgical debulking and chemotherapy, have not been successful in improving the long-term survival of these patients. Alternative therapies targeting various biomarkers, such as carcinoembryonic antigen (CEA), Tag-72, and Lewis-Y antigen, have been developed to treat patients with advanced ovarian cancers. To ensure that therapies targeting these biomarkers are effective, it is imperative to determine whether there is any differential expression of these targeted biomarkers between primary and metastatic ovarian carcinomas. In the present study, primary and metastatic lesions from 68 and 58 patients, respectively, including primary and matched metastatic lesions from 31 patients, were evaluated for cytoplasmic and membranous expression of CEA (clone Col-1), Tag-72 (clone CC-49), and Lewis-Y antigen (clone BR-96) by immunohistochemistry. No significant differences were observed with cytoplasmic and membranous expression of Tag-72 (CC-49) and Lewis-Y antigen (BR-96) in the primary and metastatic, matched and unmatched lesions (Wilcoxon signed-rank test). Although there was no statistically significant difference in the scores of CEA (Col-1) between primary and metastatic lesions, 5 of 11 (45%) cases with positive staining with CEA (Col-1) demonstrated discordant results between primary and metastatic lesions. There was a moderate positive correlation of the cytoplasmic and membranous expression of Tag-72 (CC-49), as well as cytoplasmic expression of BR-96 between primary and metastatic ovarian carcinomas. There was a weak negative correlation between the membranous expression of CEA (Col-1) and that of Lewis-Y antigen (BR-96); however, the difference was not statistically significant. No correlation was observed with other combinations of biomarkers. Our findings suggest that samples from either primary or metastatic ovarian carcinomas can be used for the evaluation of the expression of Tag-72 (CC-49) and Lewis-Y antigen (BR-96) to identify targets for novel therapies in patients with disseminated ovarian carcinomas. CEA (Col-1), due to its low expression and variation in phenotypic expression between primary and metastatic lesions, should be evaluated carefully in metastatic lesions before targeting the CEA antigen with CEA (Col-1)-like antibodies.

Antagonistic effects of anti-EMMPRIN antibody when combined with chemotherapy against hypovascular pancreatic cancers.

PURPOSE: To examine the antagonistic effects of anti-extracellular matrix metalloprotease inducer (anti-EMMPRIN) antibody when combined with chemotherapy using a hypovascular pancreatic tumor model. PROCEDURES: Severely compromised immunodeficient mice bearing orthotopic MIA PaCa-2 tumors were used (five to six animals per group). Dynamic contrast-enhanced magnetic resonance imaging was used to examine the relationship between tumor vascularity and size. Therapy was initiated when tumors were hypovascular. Treatments included: (1) gemcitabine alone, (2) anti-EMMPRIN antibody alone, and (3) combination, each for 2 weeks. Additionally, another treatment arm included ß-lapachone, an NAD(P)H/quinone 1 (NQO1) bioactivated agent. (18)F-fluoro-D-glucose-positron emission tomography/computed tomography imaging was used weekly to monitor therapeutic effects. RESULTS: Gemcitabine or anti-EMMPRIN monotherapy significantly delayed tumor growth, but the combination therapy showed an antagonistic effect. Similarly, tumor growth was significantly suppressed by ß-lapachone alone, and additive effects were noted when combined with gemcitabine, but the therapeutic efficacy was reduced when anti-EMMPRIN antibody was added. CONCLUSIONS: Anti-EMMPRIN antibody with chemotherapy in hypovascular tumors results in antagonistic effects.

Diffusion weighted imaging evaluated the early therapy effect of tamoxifen in an MNU-induced mammary cancer rat model.

PURPOSE: To assess the optimal time point of diffusion-weighted imaging (DWI) for early prognosis of breast cancer following tamoxifen therapy using a methylnitrosourea (MNU)-induced ER-positive breast-cancer model. METHODS: Two groups of Sprague-Dawley rats (n = 15 for group 1; n = 10 for group 2) were used. All animals (50 days old) were intravenously injected with MNU (50 mg/kg body weight) to induce ER-positive mammary tumors. When tumors were approximately 2 cm in diameter, DWI was performed on days 0, 3, and 7, and intratumoral apparent diffusion coefficient (ADC) values were measured. Therapy started on day 0 with tamoxifen (10 mg/kg diet) and continued for 4 weeks for group 1, but only 1 week for group 2, while tumor volume was measured by caliper twice weekly. All animals of group 2 were euthanized on day 7 after imaging, and Ki-67, TUNEL, ERα, and ERß staining were performed on tumor tissue. RESULTS: DW images of MNU-induced mammary tumors were successfully obtained with minimal motion artifact. For group 1, ADC change for 3 days after therapy initiation (ADC3D) was significantly correlated with tumor-volume change until day 11, but the significant correlation between ADC change for 7 days (ADC7D) and the tumor-volume change was observed until day 18. Similarly, for group 2, either ADC7D or ADC3D was significantly correlated with the tumor-volume change, but the higher significance was observed for ADC7D. Furthermore, ADC7D was significantly correlated with apoptotic (TUNEL stained), proliferative (Ki-67 stained), and ERß-positive cell densities, but ADC3D was not significantly correlated with any of those. CONCLUSIONS: ADC7D might be a more reliable surrogate imaging biomarker than ADC3D to assess effectiveness of tamoxifen therapy for ER-positive breast cancer, which may enable personalized treatment. The significant correlation between ADC7D and ERß-positive cell density suggests that ERß may play an important role as a therapeutic indicator of tamoxifen.

Retargeting of gene expression using endothelium specific hexon modified adenoviral vector.

Adenovirus serotype 5 (Ad5) vectors are well suited for gene therapy. However, tissue-selective transduction by systemically administered Ad5-based vectors is confounded by viral particle sequestration in the liver. Hexon-modified Ad5 expressing reporter gene under transcriptional control by the immediate/early cytomegalovirus (CMV) or the Roundabout 4 receptor (Robo4) enhancer/promoter was characterized by growth in cell culture, stability in vitro, gene transfer in the presence of human coagulation factor X, and biodistribution in mice. The obtained data demonstrate the utility of the Robo4 promoter in an Ad5 vector context. Substitution of the hypervariable region 7 (HVR7) of the Ad5 hexon with HVR7 from Ad serotype 3 resulted in decreased liver tropism and dramatically altered biodistribution of gene expression. The results of these studies suggest that the combination of liver detargeting using a genetic modification of hexon with an endothelium-specific transcriptional control element produces an additive effect in the improvement of Ad5 biodistribution.

(18)F-FDG PET/CT imaging detects therapy efficacy of anti-EMMPRIN antibody and gemcitabine in orthotopic pancreatic tumor xenografts.

PURPOSE: The objective of this study is to evaluate the therapeutic response to a novel monoclonal antibody targeting human extracellular matrix metalloproteinase inducer (EMMPRIN) in combination with gemcitabine in a pancreatic-tumor xenograft murine model by sequential 2-deoxy-2-[18F]fluoro-D-glucose ((18)F-FDG) positron emission tomography/computed tomgraphy (PET/CT) imaging. PROCEDURES: Four groups of SCID mice bearing orthotopic pancreatic tumor xenografts were injected with phosphate-buffered saline, gemcitabine (120 mg/kg BW), anti-EMMPRIN antibody (0.2 mg), or combination, respectively, twice weekly for 2 weeks, while (18)F-FDG PET/CT imaging was performed weekly for 3 weeks. Changes in mean standardized uptake value (SUV(mean)) of (18)F-FDG and volume of tumors were determined. RESULTS: The tumor SUV(mean) change in the group receiving combination therapy was significantly lower than those of the other groups. Tumor-volume changes of groups treated with anti-EMMPRIN monotherapy or combined therapy were significantly lower than that of the control group. CONCLUSIONS: These data provide support for clinical studies of anti-EMMPRIN therapy with gemcitabine for pancreatic cancer treatment.