bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5402: Pre-clinical treatment of adrenal cortical carcinoma with a combination of small molecule inhibitors to IGF-1R and mTOR
Authors: Frome Lauren , Ignatoski Kathy
Published: February 2011

Adrenocortical carcinoma (ACC) is a rare, aggressive cancer of the adrenal cortex. The five-year survival rate is 10-20% due to late diagnosis and lack of effective systemic therapy. The only treatment options available are surgical resection and chemotherapy in the form of mitotane; however, up to 95% of patients are not responsive to treatment, so new therapies are needed. Research has shown that the mitogenic hormone insulin-like growth factor 2 (IGF-2) is overexpressed in 93% of sporadic cases of ACC. IGF-2 binds to the receptor tyrosine kinase IGF receptor 1 (IGF-1R). Inhibition of IGF-1R has been shown to be effective against ACC in animal studies using IGF-1R targeted therapies. The major IGF-1R signaling pathway is phosphotidylinositol-3′-kinase (PI3′K), which activates AKT leading to the activation of mTOR, the mammalian target of rapamycin. Recent research has shown that mTOR may be a viable target for inhibition to treat tumors. Work in our lab has shown that a combination of mTOR inhibition by rapamycin and IGF1-R inhibition by either PQ401 or NVP-AEW54 at sub optimal doses blocks proliferation of human ACC H295R cells compared to application of either drug alone. Further investigation will be conducted in a mouse model system to determine the effects of the mTOR inhibitor everlimus (RAD001) alone and in combination with IGF1-R inhibitor OSI-906 to determine possible synergistic effects of the drugs that can be clinically applicable to treat ACC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5402.
Abstract 5409: Ron silencing by shRNA inhibits growth, induces apoptosis and sensitizes tumor response to c-Met inhibitor treatment through down-regulating MAPK signaling in B-Raf mutant colon carcinomas
Authors: Zou Helen Y. , Li Qiuhua , Qiu Ming , Tatsukawa Keith , Wu Karen , Fang Douglas , Cui Jean , Bender Steve , Gibson Neil W. , Smeal Tod
Published: February 2011

RON, the receptor for macrophage-stimulating protein, belongs to the MET receptor tyrosine kinase family and shares many common features with MET. Inappropriate activation of RON signaling plays an important roll in colon carcinoma cell proliferation, survival, migration and invasive growth. Ron and Met are overexpressed in patient colon tumors, where co-overexpression of both Ron and Met correlates with the worst patient survival compared to the overexpression of Ron or Met alone. BRaf-activating mutations occur in about 10% of colorectal carcinomas. Mutant BRaf has constitutive kinase activity and causes hyperactivation of the mitogen-activated protein kinase (MAPK) pathway, and BRaf mutant cancers are generally resistant to standard therapies. Here we report that knockdown of the Ron gene by Ron shRNA in BRafV600E mutant HT29 colon carcinoma cells induced HT29 tumor apoptosis and resulted in significant tumor growth inhibition (TGI) by 59%, which is comparable to that observed with the selective EGFR inhibitor-Erlotinib treatment (57% TGI), but more potent than that of the selective Met inhibitor-PF-04217903 treatment (38% TGI). When Ron shRNA knockdown and treatment with the selective Met inhibitor were combined, enhanced tumor growth inhibition (76%) was observed. Comparable experiments using the BRaf mutant Colo205 model yielded similar results. Western Blot analysis showed that combination of Ron shRNA and Met inhibition in HT29 cells decreased phosho-ERK, elevated cleaved caspase-3 and, surprisingly, increased total Ras protein levels. No significant changes in total and phospho-AKT levels were observed. In vitro, the stable HT29-shRon cells initially grew more slowly compared to HT29-vector cells, but the growth rate gradually increased, approaching that observed in normal cell culture conditions. Interestingly, when co-culturing stable HT29-shRon or HT29-vector cells with bone marrow derived mesenchymal stem cells, the selective Met inhibitor-PF-04217903 induced significant cell death only in the HT29-shRon cells under hypoxic conditions (1% oxygen). No cell death was observed with either HT29-shRon cells under normoxia or HT29-vector cells under hypoxia or normoxia conditions, indicating the collaborative roll of Ron and Met in colon cancer cell survival during hypoxia. In summary, inhibiting both Ron and Met pathways in BRaf mutant colon cancer cells down- regulated ERK activity, induced apoptosis and led to enhanced antitumor efficacy in vivo.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5409.
Abstract 5412: Synergistic interactions between histone deacetylase inhibitors and aurora kinase inhibitor KW2449 Ph+ cells
Authors: Nguyen Tri K. , Kolla Sarah , Dai Yun , Grant Steven
Published: February 2011

Resistance to tyrosine kinase inhibitors (imatinib, nilotinib, dasatinib) remains a major therapeutic challenge in Bcr/abl+ leukemia. Consequently, novel and more effective therapeutic strategies are urgently needed in this setting. KW-2449 is a multi-kinase inhibitor which inhibits Bcr/abl, aurora kinase, and FLT3, among other targets, and which has shown activity against T315I “gatekeeper” mutant Bcr/abl cells. Previous studies have shown that histone deacetylase inhibitors (HDACIs) such as vorinostat sharply promote the antileukemic effects of Bcr/abl and aurora kinase inhibitors such as MK-0457 in CML cells (Dai et al., Blood 112:793-804, 2008). However, MK-0457 is not currently under clinical development. The purpose of this study was to assess the effects of HDACIs (e.g., SBHA, MS-275) on responses to the dual aurora kinase-Bcr/abl inhibitor (KW-2449) in various Bcr/Abl + cells. Coadministration of HDACIs synergistically increased KW-2449 lethality in CML (K562, LAMA84) and Ph+ ALL cells (TOM-1, SD-1, SUP-B15, BV173). Notably, HDACI/KW-2449 regimens were also highly active against multiple imatinib resistant cells including BV-173/E255K, BaF3/Bcr-Abl/T315I, as well as Bcr/Abl -overexpressing and Bcr/abl-independent K562 cells. Combined treatment with HDACIs and KW-2449 was associated with inactivation and down-regulation of Bcr/Abl and its downstream target CrkL in CML and ALL cell lines including BaF3/T315I. Moreover treatment with KW-2449/HDACi resulted in a pronounced increase in DNA damage (γH2A.X) documented by Western blot and confocal microscopy. In addition, coadministration of HDACIs and KW-2449 strikingly blocked phosphorylation of histone H3, a marker of aurora kinase inhibition, and diminished HDACI-induced p21CIP1 expression. Notably, down-regulation of Bim by siRNA significantly diminished the lethality of the HDACI/KW-2449 regimen. Treatment of K562 cells with HDACIs alone resulted in G1S arrest, an effect abrogated by KW-2449, and which resulted in pronounced cellular endoreduplication. Furthermore, knockdown of either Aurora A or Aurora B in K562 cells dramatically increased the HDACI-mediated cell death. Finally, cotreatment with KW-2449 and HDACIs significantly increased cell death in seven CML primary samples (including both naïve and imatinib-resistant specimens, one carrying the I242T, Y257C mutations) compared to treatment with either agent alone, while exhibiting minimal toxicity to normal CD34+ progenitors. Together, these findings indicate that HDACIs strikingly increase KW-2449 activity against IM-sensitive and -resistant Bcr/Abl+ cells, and suggest that this strategy warrants further attention in Bcr/abl+ leukemias.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5412.
Abstract 5427: Combination of aflibercept (VEGF trap) and docetaxel produces increased antitumor effects associated with enhanced changes to tumor vasculature
Authors: Abrahams Cristina , Li Baosheng , Parveen Asma , Thurston Gavin
Published: February 2011

VEGF blockade in combination with chemotherapy has shown increased anti-tumor efficacy in preclinical models and clinical studies. However, the mechanism by which combination treatments result in enhanced effects is not well understood. In this study, we sought to characterize the mechanism for improved effects of aflibercept plus docetaxel on HT1080, a human fibrosarcoma line that is resistant to anti-VEGF treatment. Immunodeficient SCID mice bearing subcutaneous HT1080 tumors (size ∼100 mm3) were treated with either control protein (hFc) plus docetaxel vehicle, aflibercept (25 mg/kg s.c.), docetaxel (4.5 mg/kg i.v.), or the combination. Following three treatments administered every 3-4 days, tumors were left to grow and harvested when the average size of the treatment group reached ∼600mm3. We found that combination treatment with aflibercept plus docetaxel was significantly more efficacious than either single agent. Although treatments with docetaxel alone and in combination with aflibercept both initially regressed tumor size, the combination was significantly more effective at delaying long-term tumor regrowth. In tumors harvested 24 hrs after the last treatment, combination treatment produced a dramatic decrease in the number of proliferating cells and a concomitant increase in pyknotic cells. Aflibercept or docetaxel alone had only modest effects on the vessels in this tumor, whereas the combination treatment resulted in pruned vessels with less branching, some vessels with punctate endothelial cell staining, and an increase in TUNEL-positive endothelial cells. These results suggest that combination of aflibercept plus taxols (docetaxel) causes enhanced effects on the tumor vessels, thus improving efficacy in tumors with vasculature that exhibit resistance to VEGF blockade. Further understanding the mechanistic basis underlying these combination treatments may provide insight into improving current strategies to manage tumors resistant to antiangiogenic therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5427.
Abstract 5462: Enhancing efficacy of drugs by targeting CXCR2 receptor signaling for the treatment of malignant breast cancer
Authors: Sharma Bhawna , Nawandar Dhananjay , Varney Michelle L. , Nannuru Kalyan C. , Singh Rakesh K.
Published: February 2011

Breast cancer is the second most common cause of cancer death in women in the United States after lung cancer and is responsible for more than 40,000 deaths each year. Many challenges exist in the current management of advanced stage breast cancer as there are fewer recognized therapeutic strategies, often due to therapy resistance. Recent reports suggest that malignant cells that survive initial chemo- and radiation therapy often express inflammatory cytokines, which provides survival benefit making tumors resistant to further chemotherapy. The specific objective of the study is to develop strategy to manipulate chemokine-chemokine receptor network for effective therapy with limited toxicity against drug-resistant breast cancer. We investigated whether modulation of CXCR2-dependent signaling in malignant mammary tumor enhances therapeutic efficacy of chemotherapy drugs. We used mammary tumor cells expressing different levels of CXCR2 (Cl66-wt and Cl66-shCXCR2) and examined their response to Paclitaxel and Doxorubicin. We observed significant enhancement of paclitaxel and doxorubicin-mediated toxicity at concentrations 5 and 10nM in Cl66-shCXCR2 cells as compared to Cl66-wt cells. Moreover, the expression of CXCL1, a CXCR2 ligand, was increased in paclitaxel and doxorubicin treated mammary tumor cells. Paclitaxel and doxorubicin induced CXCL-1 levels was significantly lower in Cl66-shCXCR2 cells as compared to Cl66-wt cells. In vivo studies using wild type and knockdown cells showed no significant difference in the tumor growth. However, we observed a difference in the tumor growth between wild type and knockdown tumors in mice treated with 10mg/kg concentration of paclitaxel for 3 weeks after starting the treatment. When these studies were further extended there wasn't any difference between the two groups. Furthermore, we extended these studies using human breast cancer cell lines (MDA-MB231, MDA-MET, and SKBR3). MDA-MB231 and MDA-MET are triple negative and considered to be more metastatic and drug resistant than SKBR3 which is HER2-over expressing cell line. We observed differential expression of CXCR2 and its ligands in these cells. Our observation also showed significant difference in the paclitaxel and doxorubicin-mediated inhibitory response in MDA-MB231 and MDA-MET cells as compared to SKBR3 cells. Together these studies demonstrate that manipulating CXCR2-dependent activity in malignant breast cancer cells significantly enhanced therapeutic efficacy of paclitaxel and doxorubicin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5462.
Abstract 5474: Targeting endothelial tubulogenesis for anticancer therapeutic development
Authors: Roy Anshu Mittal , Zhai Ling , Wennerberg Krister , Waud William R. , Gormon Gregory S. , Coward Lori , Li Rongbao , Ananthan Subramaniam , Qu Zhican
Published: February 2011

The clinical successes of VEGF-targeted agents in recent years have demonstrated that antiangiogenic therapy can be developed as effective anti-cancer treatment. However, the field of oncology is facing a new challenge of overcoming the resistance to VEGF-targeted therapy; therefore, novel angiogenesis inhibitors are required for new therapeutic development. During the growth of new blood capillaries, following proliferation and migration, endothelial cells undergo morphological changes and adhere to each other forming tubular structures as a process of tubulogenesis, which presents a unique target for inhibitory action of antiangiogenic agents. Southern Research angiogenesis research team has identified a structurally related series of heterocyclic compounds SRI-24637 and its analogs as a new class of antiangiogenic agents. SRI-24637 demonstrated selective potent inhibition of endothelial tube-formation and significant activity in blocking tumor-induced blood vessel formation using an ex vivo human cancer xenograft-CAM assay model system. The mechanism of action of SRI-24637 is different from the clinical VEGF-targeted drugs; therefore, it may provide a complementary mechanism to overcome the resistance to VEGF-targeted therapies. Bioavailability studies showed that SRI-24637 dosed at 40 mg/kg in DMSO/PEG400 reached systemic concentration levels much higher than the IC50 concentration for in vitro endothelial tube-formation. Comparing with the clinical VEGF-targeted drug Sunitinib, the cytotoxic activities of SRI-24637 against normal human fibroblast and epithelial cells suggest that the toxic side effects of SRI-24637 may be within a tolerable range. Ongoing preclinical efficacy studies with animal tumor models will aid in the development of SRI-24637 as an anti-cancer drug. Based on the outcome of these studies, further lead optimization will be done if required, before entering it into the clinical Phase I and II trials using protocols similar to those employed for Sunitinib and Sorafenib, or other investigational small molecules targeting tumor angiogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5474.
Abstract 5477: Gefitinib enhances arsenic trioxide (AS2O3)-induced differentiation of acute promyelocytic leukemia cell line
Authors: Noh Eui-Kyu , Kim Hawk , Park Min Jae , Baek Jin Ho , Park Jae-Hoo , Cha Seung Joo , Min Young Joo
Published: February 2011

Gefitinib (Iressa, ZD1839), a selective epidermal growth factor receptor tyrosine kinase inhibitor, inhibits growth, invasion and colony formation of various cancer cells. However, little is known about the effect of combination of gefitinib and arsenic trioxide (ATO) on differentiation of acute promyelocytic leukemia (APL). Therefore, we investigated whether gefitinib had any role in the ATO-induced differentiation of NB4 cells (APL cell line). Gefitinib induced the expression of differentiation markers including CD11b and CD14 in ATO-treated NB4 cells and facilitated ATO-induced morphologic changes and ROS generation. The results were evident that the combination of gefitinib and ATO could induce more effectively functional differentiation of leukemic cells to macrophage-like cells. Moreover, the extracellular-signal regulated kinase (ERK) pathway was necessary for the enhancement of gefitinib in ATO-induced differentiation, measured by CD11b and CD14 expression on NB4 cells. Therefore, our data indicated that gefitinib can play a potential role as an adjunctive differentiation agent in APL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5477.
Abstract 5544: ASPM is a novel participant in DNA double-strand break repair and a potential target for radiotherapy
Authors: Fujimori Akira , Kato Takamitsu
Published: February 2011

Comprehensive serach for human cellular response to ionizing radiation (IR) is indispensable strategy to understand the molecular basis under tumor radiotherapy. In a previous study using HiCEP, we found that ASPM (Abnormal spindle-like microcephaly-associated) or the most common-type microcephaly (MCPH5) gene is selectively down-regulated by IR. Here we first demonstrate that down-regulation of ASPM by siRNA synergistically enhanced radiosensitivity in some immortalized human cell lines. Both constant-field gel electrophoresis and gamma-H2AX foci assay exhibited impaired DNA double-strand breaks (DSB) in the cells treated with the siRNA. Greater extent of chromosomal instability was also common in the treated cells than untreated control. Getting together, ASPM (MCPH5) is a novel participant in the DNA double-strand break repair pathways. Although roles of microcephalins (MCPH1, pericentrin, ATR) have recently been proposed on DNA damage repair and check point regulation, this is the first report on ASPM. In clinical aspects, ASPM would be a promising target for the future cancer treatment as well as a useful biomarker in the prognostic strategy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5544.
Abstract 5558: The expression and characterization of up-regulated inosine monophosphate dehydrogenase type 2 (IMPDH2) in colorectal adenocarcinoma tissues by proteomic analysis
Authors: Shim Doobo , Kang Jung H. , Park Eun S. , Kang Kee R.
Published: February 2011

Colorectal cancer is one of the most prevalent tumors in developed countries, and the best characterized cancers with regard to genetic progression of disease. Recent improvement in methods for proteome analysis has offered the possibility of identifying disease-associated protein markers to assist in diagnosis or prognosis, and for selecting potential targets for specific drug therapy. For identification and targeting of tumor-associated marker proteins, the proteome of colorectal adenocarcinoma (CRC) and normal colorectal tissues was analyzed by 2-DE. Inosine monophosphate dehydrogenase type 2 (IMPDH2), a key enzyme of de novo purine nucleotide biosynthesis, was identified by MALDI-TOF/MS and found to be expressed at high rates in the colorectal tumor tissues. We found an increased amount of IMPDH2 mRNA in CRC compared to that observed in the normal colorectal tissues by Northern blot. Real time PCR analysis in both tissues also revealed the higher expression of IMPDH2 mRNA in CRC. Western blot analysis was carried out to confirm the elevated expression of protein level for IMPDH2 in CRC compared with normal tissues. Immunohistochemical studies denoted that tumor tissues showed higher N/C ratio, abnormal shape of gland, and darker staining in glandular area. In addition, using in situ hybridization, it was demonstrated the expression of IMPDH2 in CRC tissues was extremely high in the vicinity of mucosal gland, while IMPDH2 in the normal colorectal tissues was evenly distributed in all tissue area with lower level. These findings suggest that IMPDH2 could be a possible tumor biomarker candidate in CRC tissues. This study was supported by KOSEF grant (R13-2005-012-01003-0) and KRF grants (2006-005-J04203).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5558.
Abstract 5586: NK cell killer Ig-like receptor (KIR) genotype as a novel biomarker for neuroblastoma patients receiving Anti-GD2 monoclonal antibody 3F8
Authors: Venstrom Jeffrey M. , Zheng Junting , Kushner Brian H. , Modak Shakeel , Danis Karen E. , Cheung Irene Y. , Dupont Bo , Cheung Nai-Kong , Hsu Katharine C.
Published: February 2011

Background: Natural killer (NK) cells are regulated by inhibitory killer Ig-like receptors (KIRs) that recognize specific HLA class I ligands. KIR-HLA genotypes are tightly linked to NK cell function and clinical outcomes in allogeneic and autologous hematopoietic stem cell transplantation (HSCT). Because NK cells contribute to antibody-dependent cellular cytotoxicity, we hypothesized that specific KIR-HLA genotypes may predict NK cell responsiveness to mAb therapy, and thus, may be useful clinically to identify patients likely to respond to mAb therapy. Methods: 76 children with high risk neuroblastoma received cyclophosphamide-containing induction chemotherapy followed by murine IgG3 monoclonal antibody 3F8 against ganglioside GD2 between 1993 and 2007. HLA and KIR genotyping was performed, and patients were segregated into KIR-HLA groups based on known functional KIR-HLA ligand relationships: KIR2DL2/2DL3 with HLA-CAsn80(HLA-C1 group), KIR2DL1 with HLA-C Lys80(HLA-C2 group), and KIR3DL1 with HLA-Bw4. Overall survival and progression-free survival were estimated by Kaplan-Meier method and hazard ratios by Cox regression. No adjustments were made for multiple comparisons. Comparisons of each end point were based on the log-rank statistics. Results: 63% of the 76 children lacked at least 1 HLA ligand for his/her inhibitory KIR. At 3 years, 80% of patients lacking any KIR ligand (n=46) were alive compared with 69% of patients with all HLA ligands present (n=30) (HR 0.41; 95% CI 0.17-0.98; P=0.04). 23/23 (100%) patients specifically lacking the HLA-Bw4 ligand for KIR3DL1 were alive at 3 years compared with 34/52 (67%) patients exhibiting HLA-Bw4 for KIR 3DL1 (n=52) (HR 0.20; 95% CI 0.05-0.87; P=0.02). Conclusion: KIR-HLA immunogenetics may be a novel biomarker for neuroblastoma patients receiving chemo-immunotherapy. The milieu of HSCT may not be required for NK cells to behave according to “missing ligand,” and KIR-HLA combinations may be predictive of outcome for other malignancies similarly treated with mAb.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5586.
Abstract 56: Differential expression of fatty-acid-binding proteins 3 and 5 among African American and Caucasian women with breast cancer
Authors: Calderon Teleka , Singh Sharda Kalla , Leon Marino De , Leon Daisy De
Published: February 2011

Breast cancer is a major cause of mortality among middle-aged and elderly women. It is well documented that African-American (AA) patients tend to present with more advanced states of breast cancer and have lower survival rates than Caucasian-Americans (CA). Additionally, the age specific breast cancer incidence rate for AA women under age 35 is greater than twice the rate for CA of similar age, and the mortality rate is more than three times greater. Some of this disparity is due to socioeconomic factors; however, biological factors may also be involved. Altered expression of intracellular fatty-acid binding proteins (FABPs) has been implicated in the progression of breast cancer. FABP3 (heart/muscle type), also known as mammary-derived growth inhibitor (MDGI), is associated with differentiation of breast tissue, and is downregulated in breast cancer tissues. FABP5 (epidermal type) is upregulated in breast cancer tissues as a possible compensation for FABP3's decrease. Therefore, we hypothesized that AA malignant breast tissue samples would contain lower levels of FABP3, and higher levels of compensatory FABP5. We determined levels of the aforementioned proteins and the corresponding mRNA in paired breast tissue samples from AA and CA women by Western blot analysis and RT-PCR. Data was divided into three groups- ages 17-45, ages 45-65, and ages 66 and up. In ages 17-45, FABP3 protein levels were higher in AA malignant tissues relative to CA malignant, and FABP5 protein levels were similar between racial groups. Also, FABP3 levels were decreased in AA malignant tissues compared to AA normal. In ages 46-65, levels of FABP3 protein, and of FABP5 protein and mRNA, were higher in AA malignant tissues relative to CA malignant. Furthermore, FABP3 protein levels were increased in AA malignant tissues relative to AA normal tissues. In ages 66 and up, levels of both FABPs were similar between AA malignant and CA malignant tissues. However, mRNA levels of both FABPs were significantly increased in the CA malignant tissues compared to AA malignant. In addition, levels of FABP3 and FABP5 were increased in the AA malignant tissues relative to the AA normal tissues. Thus, it appears that the conventional knowledge regarding FABP3 downregulation in breast cancer may only apply to AA cancer patients below age 45. Furthermore, in ages above 66, AA breast cancer patients are at a significant disadvantage compared to their CA counterparts, as it relates to expression of FABPs 3 and 5. Further study is needed to elucidate the mechanisms involved in this differential FABP expression pattern between the racial groups, and its implication on the survival disparity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 56.
Abstract 5606: Preclinical and clinical development of anti-CD25 recombinant immunotoxin LMB-2 in combination with chemotherapy for the treatment of adult T-cell leukemia
Authors: Singh Rajat , Zhang Yu Jian , Pastan Ira , Kreitman Robert J.
Published: February 2011

LMB-2, previously called anti-Tac(Fv)-PE38, is a recombinant immunotoxin containing the variable domains of the anti-CD25 Mab and a truncated form of Pseudomonas exotoxin. LMB-2 binds and internalizes via CD25, and a processed toxin fragment translocates to the cytosol where catalytic ADP-ribosylation leads to cell death. LMB-2 induces complete and partial responses (CR + PR) in patients with CD25+ hairy cell leukemia, and partial responses were reported in other hematologic malignancies including adult T-cell leukemia (ATL). While nearly all ATL cells express CD25 at high levels, clinical efficacy was limited by rapid progression between cycles and immunogenicity. Recently, preclinical studies using the anti-mesothelin recombinant immunotoxin SS1P indicated that soluble receptor is ∼10-fold higher in the interstitial space of the tumor xenograft than in the serum (PNAS, 104:17099, 2007) and that gemcitabine was synergistic against the xenografts when used prior to SS1P to deplete interstitial soluble receptor (Clin Cancer Res, 13:7166, 2007). To determine if soluble CD25 (sCD25) in the interstitial space of tumors could be a limiting factor in the antitumor activity of LMB-2 in ATL, xenografts of CD25+ human ATAC-4 cells were grown subcutaneously in nude mice and harvested so that the serum and intratumoral sCD25 concentrations could be compared. Intratumoral sCD25 concentrations were 21-159 (median 43) ng/ml, compared to between undetectable and 0.33 (median 0.093) ng/ml in serum (p=0.0008, n=8). Thus, intratumoral sCD25 was 86-2200 (median 610)-fold higher than serum sCD25 in this model. To determine if chemotherapy would improve the efficacy of LMB-2 towards these tumors, groups of ATAC-4-bearing mice (tumor implantation day −3) were treated with gemcitabine on days 1 and 3, and then LMB-2 on days 3, 5 and 8. Mice treated on this schedule with gemcitabine 40 mg/Kg x2 and LMB-2 50 ug/Kg x3 had smaller tumors than mice treated with twice the dose of either agent alone, confirming in vivo synergy, with the mechanisms currently under study. A clinical trial in ATL is now underway with fludarabine and cyclophosphamide on days 1, 2, and 3 followed by LMB-2 on days 3, 5 and 7, to determine if chemotherapy can prevent immunogenicity, enhance the antitumor activity of the immunotoxin, and when possible, determine if intratumoral sCD25 is depleted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5606.
Abstract 5608: Sipuleucel-T treatment results in sequential ex vivo activation of APCs and T cells during the culture step - evidence for in vivo immunological priming
Authors: Sheikh Nadeem A. , dela Rosa Corazon P. , Frohlich Mark W. , Urdal David L. , Provost Nicole M.
Published: February 2011

Introduction. Sipuleucel-T is an investigational autologous immunotherapy for the treatment of prostate cancer. Product potency is measured in part by antigen presenting cell (APC) expression of CD54. Previous data have shown that CD54 upregulation correlates with APC activation (Sheikh 2008). This study investigated the ex vivo activation profile of T cells from men with metastatic castrate resistant prostate cancer enrolled in a Phase 3 study (D9902B, IMPACT) evaluating the safety and efficacy of sipuleucel-T treatment. Methods. Sipuleucel-T was prepared by incubating mononuclear cells isolated from leukapheresis obtained at Wks 0, 2, and 4 with PA2024 (a recombinant fusion protein comprising prostatic acid phosphatase and GM-CSF) ex vivo for 2 days, after which washed cells were infused. 512 subjects were randomized to sipuleucel-T or placebo (2:1). As part of product characterization efforts, fresh pre- and post-culture (final product - FP) T cells were evaluated in sipuleucel-T products by flow cytometry. The culture supernatant was evaluated for the production of APC and T cell activation-associated cytokines by multiplex luminex assay. Results. APC activation as measured by CD54 upregulation increased from Wk 0 to Wk 2 (P < 0.001) and persisted at the third dose (P < 0.001, Wk 0 vs Wk 4). An analysis of the culture supernatant at each week showed increases in both APC activation-associated cytokines (IL-1α, IL-1β, IL-10, IL-12p70, IL-23, IFNγ, and TNFα) and T cell activation-associated cytokines (IL-2, IL-4, IL-5, IL-10, IL-17, IFNγ, and TNFα). CD134 (OX40), CD137 (4-1BB), CD278 (ICOS), and CD279 (PD-1) expression increased in both CD4+ and CD8+ T cells at Wk 2, with expression diminished at Wk 4. Conclusion. Following The Wk 0 dose, sipuleucel-T products demonstrate evidence of increased APC and T cell activation markers as well as production of T cell activation-associated cytokines. These data provide strong evidence that sipuleucel-T activates APCs ex vivo and facilitates in vivo and ex vivo priming of T cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5608.
Abstract 561: Establishment and characterization of matched pairs of human prostate stromal cells to study cancer-stromal interaction
Authors: Sun Xiaojuan , He Hui , Xie Zhihui , Qian Weiping , Yates Clayton , Marshall Fray F. , Zhau Haiyen E. , Chung Leland W. k. , Wang Ruoxiang
Published: February 2011

Prostate stromal cells may play binary roles in the process of prostate cancer development. Being the first to be encountered by infiltrating prostate cancer cells, prostate stromal cells form the first defense line against prostate cancer progression and metastasis. On the other hand, interaction between prostate cancer and stromal cells may facilitate the formation of a tumor microenvironment favoring cancer cell growth and survival. To establish an experimental system for studying the interaction between cancer and stromal cells, we isolated three matched pairs of normal and cancer-associated human prostate stromal cells. The specimens were from three prostate cancer patients who underwent radical prostatectomy in the Department of Urology, Emory University School of Medicine. From each prostate, a cube of prostate tissue was dissected from a histologically normal region distal to the tumor, and another cube was dissected from a cancer-affected zone. Live cells in single cell preparation were cultured in low density for isolation of stromal clones. In contrast to the LNCaP prostate cancer cells, the isolated prostate stromal clones exhibited large fibroblastic morphology with slow growth rate. Growth and survival of the stromal clones were not affected by androgens and were highly resistant to serum starvation. In contrast to the normal counterparts, the cancer-associated stromal clones exhibited differentiated survival ability, as determined by colony formation assay following serum starvation. In direct co-culture, the prostate stromal cells inhibited growth of the LNCaP cells and made the production of Prostate Specific Antigen (PSA) less sensitive to androgen deprivation. Importantly in co-culture experiments, the stromal cells protected some LNCaP prostate cancer cells from death by serum starvation, and cancer-associated stromal clones showed more protection. The surviving LNCaP clones showed features of androgen-independent PSA expression similar to the lineage-related androgen-independent C4-2 cells, suggesting that cancer cells acquired increased malignancy through interaction with the stromal cells. The results from this study indicate that matched stromal cell pairs may serve as models for comparative analysis of molecular changes in the tumor microenvironment. These cells can also be used in co-culture with prostate cancer cells to simulate cancer-stromal interaction in the tumor microenvironment in order to define the role of prostate stromal cells in prostate cancer progression and metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 561.
Abstract 5612: Pretreatment with chemotherapy can enhance the immunogenicity of tumors by promoting adaptive immune responses
Authors: Liu Wai M. , Fowler Daniel W. , Smith Peter , Dalgleish Angus G.
Published: February 2011

Cancer patients are typically immuno-compromised, and it has been long felt that immune-intervention is not compatible with standard chemotherapies. However, evidence suggests that standard chemotherapy drugs may stimulate beneficial changes in both the immune system and tumour. We have assessed the impact of chemotherapy agents (cyclophosphamide, oxaliplatin and gemcitabine (GEM)) on the potential immunogenicity of tumour cells (A549, Caki2, HCT116, MCF7 and PC3), and investigated the interactions between supernatants derived from these stressed cells and cells of the immune system, by studying the activities between dendritic cells and T-cells. Results showed that some chemotherapy agents can increase total MHC class I expression on tumour cells, even when expression is low. For example, expression on MCF7 cells was increased by ∼4-fold upon treatment with GEM (133 ± 31 vs. 33 ± 7.8 in untreated cells; p<0.001). The increases in expression were associated with enhanced killing by cytotoxic T-cells (e.g. in HCT116, the MTT reading for GEM pre-treated tumour cells cultured with T-cells was 0.17 ± 0.011 vs. 0.12 ± 0.0096 in untreated tumour cells with T-cells added; p=0.007), which were negated by HLA1-blockade. Results also showed that the supernatants derived from tumours treated with chemotherapy augmented DC-maturation as indicated by increases in the maturation markers CD80/CD83/CD86. Furthermore, DC function was enhanced as confirmed by an increase in DC-mediated proliferation of CFSE-loaded T-cells. For example, the percentage of CD3+/CD4+ cells with a reduced CFSE content (indicating proliferation) was higher in cells exposed to supernatants derived from GEM treated A549 cells (12 ± 2.1% vs. 5.2 ± 1.4% in controls where the supernatant was from untreated tumours; p=0.028). In summary, there is evidence that a facet of immune surveillance can be restored by appropriate chemotherapy agents. Also, tumours exposed to some chemotherapy may deliver signals that can mature DCs, which ultimately enhances T-cell responses.

This work was supported by the Cancer Vaccine Institute.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5612.
Abstract 5627: Antitumor activity of soluble beta-1,3/1,6 glucans: Structure matters
Authors: Vasilakos John P. , Bose Nandita , Chan Anissa SH. , Danielson Michael E. , Elmasry Natalie , Gorden Keith B. , Guerrero Faimola O. , Magee Andy , Maristany Carolyn M. , Walsh Richard M. , Will Paul M. , Wurst Lindsay R.
Published: February 2011

Beta-glucan is a pathogen-associated molecular pattern recognized by a variety of innate immune cells. Beta-1,3/1,6 glucans possess numerous immune potentiating activities. In particular, antitumor activity has been demonstrated with the soluble beta glucan Imprime PGG used in combination with complement-activating antitumor monoclonal antibodies (MAb) in several tumor models. Structurally, beta-1,3/1,6 glucans can vary on the basis of chain length, types of linkages, branching, and tertiary structure. Previously, the antitumor activity of soluble beta-1,3/1,6 glucans in combination with antitumor MAb has only been reported using beta glucans derived from yeast. The primary objective of this study was to compare the antitumor activity of three structurally distinct soluble beta-1,3/1,6 glucans in vivo in a mouse syngeneic lymphoma model. Tumor-bearing mice were administered antitumor MAb plus beta glucan 2x/week for 4 weeks. Antitumor activity was based on inhibition of tumor growth at the tumor implantation site and enhanced long-term survival. In addition, critical innate immune cells responsible for antitumor activity were identified focusing on the role of neutrophils. Also, characterization of relevant human immune cells and their beta glucan receptors will be shown focusing on complement receptor 3 (CR3) and dectin-1. Beta glucan binding to immune cells and identification of relevant receptors were determined by flow cytometry using beta glucan-specific antibody and fluorescently-labeled beta glucans. Key findings are that soluble beta glucans, which differ structurally, do not induce similar antitumor activity, and antitumor activity is abrogated in granulocyte-deficient mice. Finally, soluble glucans bind to human neutrophils in a CR3-dependent manner.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5627.
Abstract 5640: KRAS and BRAF in rectal cancer treated with preoperative chemoradiotherapy
Authors: Gaedcke Jochen , Grade Marian , Jung Klaus , Wolff Hendrik A. , Beissbarth Tim , Becker Heinz , Ried Thomas , Ghadimi Michael
Published: February 2011

KRAS and BRAF are mutated in 35% and 10% of colorectal cancers, respectively. However, data for locally advanced rectal cancer patients specifically are scarce and the frequency of KRAS mutations in codons 61 and 146 remains to be established. Therefore DNA was isolated from pretherapeutic biopsies of 94 patients who were treated within the clinical trials receiving preoperative chemoradiotherapy. Mutation status of KRAS exon 1-3 as well as BRAF exon 15 was established using ABI PRISM Big Dye Sequencing Kit and subsequently correlated with clinical parameters. KRAS was mutated in 49 patients (52%). 29 mutations (64%) were located in codon 12, ten (22%) in codon 13, and three (7%) in each codons 61 and 146. No V600E BRAF mutation was detected. The presence of KRAS mutations was not correlated with tumor response or lymph node status after preoperative chemotherapy. When KRAS exon 1 mutations were separated based on the amino acid exchange, we again failed to detect significant correlations (p=0.052). However, G12V mutations appeared to be associated with higher rates of tumor regression than G13D mutations (p=0.0124). We are therefore the first to report the mutation status of KRAS and BRAF in pretherapeutic biopsies. The high number of KRAS mutations in codons 61 and 146 emphasizes the importance to expand current mutation analyses whereas BRAF mutations are not relevant for carcinogenesis. Although KRAS mutation status was not correlated with response, the subtle difference between G12V and G13D mutations warrants analysis of a larger patient population.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5640.
Abstract 5647: EGCG suppresses the growth of human hepatocellular carcinoma cells by inhibiting activation of the VEGF/VEGFR axis
Authors: Kubota Masaya , Shirakami Yohei , Shimizu Masahito , Adachi Seiji , Moriwaki Hisataka
Published: February 2011

The receptor tyrosine kinase (RTK) vascular endothelial growth factor (VEGF) receptor (VEGFR) plays an important role in tumor angiogenesis of hepatocellular carcinoma (HCC). (−)-Epigallocatechin gallate (EGCG), the major biologically active component of green tea, inhibits growth in a variety of human cancer cells by inhibiting the activation of several types of RTKs. In this study, we examined the effects of EGCG on the activity of the VEGF/VEGFR axis in human HCC cells. The levels of total and phosphorylated (i.e. activated) form of VEGFR-2 protein (p-VEGFR-2) were observed to increase in a series of human HCC cell lines in comparison to the Hc normal human hepatocytes. EGCG preferentially inhibited the growth of HuH7 HCC cells, which express the constitutive activation of the VEGF/VEGFR axis, in comparison to Hc cells. Treatment with HuH7 cells with EGCG caused a time- and dose-dependent decrease in the expression of VEGFR-2 and p-VEGFR-2 proteins. The production of VEGF from HuH7 cells was reduced by the treatment with EGCG. Drinking of EGCG significantly inhibited the growth of HuH7 xenografts in nude mice and this was associated with the inhibition of the activation of VEGFR-2 and its related downstream signaling molecules, including ERK and Akt. EGCG drinking also decreased the expression of Bcl-xL protein and VEGF mRNA in the xenografts. These findings suggest that EGCG can exert, at least in part, its growth inhibitive effect on HCC cells by inhibiting the VEGF/VEGFR axis. EGCG might therefore be useful in the treatment of HCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5647.
Abstract 5652: Cytoplasmic expression of estrogen receptors in breast cancers
Authors: Choi Young J.
Published: February 2011

Nuclear expression of estrogen receptor(ER)-A has been used as the prognostic and therapeutic marker for breast cancer. However, ER cytoplasmic expression (CyE) has not gained such support for its contribution to estrogenic response and clinical significance. Membrane ER or unliganded cytoplasmic hormone receptors may represent non-genomic actions of ER or subcellular dislocation during malignant transformation due to inappropriate /dysfunctional trafficking of transcription factors and cofactors. Here, we tested CyE of ERs in breast cancer tissues and breast cancer cell lines (BCC) to further define its role.

Design; Tissue microarray sections of 271 cancers, 45 normals, 62 benign proliferative disease (BPD) of breast tissues and 11 BCC (MCF-7, T-47D, ZR-75, MB-361,MB 468, BT 474, MB-453, SK-BR-3,MB-231, Hs578T, BT-549) were tested by immunohistochemistry for the expression of ER-A (ID5, Dako), 5 different clones of ER-B (AR385-5R, Biogenex; PPG5/10, Dako;Ab288/14C8, ABCAM; EMR02, Novacastra; 57/3, AbD Serotec), Her-2 (HercepTest, Dako), Ki-67, AIB-1 (Clone 34, BD), TIF-2 (Clone 29, BD). Non-specific protein and peptide antigen were blocked by using serum block (Dako, CA) and peptides, respectively. Over 5% positive nuclear and cytoplasmic expression in each tissue core was considered positive.

Results: ER-A-CyE was noted in 9.0% (27/271) of breast cancers; 6 were ER-A-/Her-2+, and 3 were ER-A+/Her-2+. One BCC, BT474 with ER-A+/Her-2+ showed ERA-CyE. ER-B-CyE was noted in 29.1 % (81/271) of cancers and 4 of 11 BCC. CyE of 5 ER-B clones were consistent expression in each breast tissue and BCC. The staining of ER-B-CyE in BCC showed diffuse, membranous or dotted appearance. In breast cancer, that of ER-B-CyE was diffuse and was prominent in high grade cancer with desmoplastic reaction and heavy lymphocytic infiltration. ER-B-CyE was noted in 47.0 % (47/100) of stage IV cancer including recurrent and tamoxifen resistant cancers, and 19.2 0% (33/171) stage I to III cancers. ER-B-CyE was associated with over expression of Her-2 in 22.2% (18/81), Ki-67 in 23.4% (19/81), TIF-2 in 46.5% (38/81) and AIB-1 in 21.0% (17/81). Only cytoplasmic ER-A and ER-B in breast cancer was noted in 3.3% (9/271) and in 8.4% (23/271), respectively. CyE levels in normals and BPD tissues were insignificant.

Conclusion:

Our study demonstrates the potential significance of cytoplasmic ER, particularly ER-B. Proteins translated from single and multiple exon deletion variant transcripts which lack nuclear localization signals may remain in the cytoplasm of breast cancer tissues and contribute to estrogen responses. Further study is in progress to test cytoplasmic expression of various ER isoforms.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5652.