bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4439: A reversibly self-crosslinking nano-carrier system for efficient anticancer drug delivery
Authors: Li Yuanpei , Xiao Kai , Luo Juntao , Xiao Wenwu , Lee Joyce , Lam Kit S.
Published: June 2012

It is known that the intracellular concentration of glutathione (GSH) is substantially higher than that in the cellular exterior (∼10 mM vs ∼2 μM) and many types of tumor cells have an elevated GSH level compared to normal cells. This dramatic variation of the GSH concentration provides an opportunity for designing tumor specific drug delivery systems. Most of the chemotherapeutic drugs used in clinic suffer from severe dose-limiting side effects. In order to enhance the therapeutic efficacy and minimum the side effect of these drugs, we developed a stable and efficient nano-carrier drug delivery system based on the disulfide crosslinked micelles comprise of poly (ethylene glycol) (PEG) and dendritic oligmers of cholic acids and cysteines. Various poorly water-soluble anticancer drugs can be efficiently incorporated inside these polymeric nano-carriers. The nano-carriers are stabilized by disulfide bridges in the core to avoid premature release of the loaded drugs during circulation. After reaching the tumor sites via enhanced permeability and retention (EPR) effect, the nano-carriers will disassemble to release the core-loaded drugs upon the cleavage of disulfide bridges under reductive conditions following the intracellular uptake or triggered by additional reducing agents. The crosslinked nano-carriers were spherical with a uniform size of 30 ± 5 nm, and can load paclitaxel (PTX) in the core with drug loading content up to 35% (w/w). Cross-linking of the nano-carriers within the core reduced their critical aggregate concentration and greatly enhanced their stability in non-reductive physiological conditions. The release of PTX from the crosslinked nano-carriers was significantly slower than that from non-crosslinked nano-carriers and can be gradually facilitated in a reducing environment. The fluorescence intensity of BODIPY 650/665 (near infrared dye) labeled disulfide crosslinked nano-carriers sustained up to 24 hours within the blood stream of nude mice while that of non-crosslinked nano-carriers decreased faster and fell into the background level within 8 hours post injection. Targeted drug delivery to tumor site with these crosslinked nano-carriers was demonstrated by near infrared fluorescence imaging in nude mice bearing ovarian cancer xenograft. The nano-formulation of PTX was found to be less toxic than its free drug form in nude mice. We further demonstrated the crosslinked nano-formulation of PTX was more efficacious than both free drug and non-crosslinked nano-formulation of PTX in ovarian cancer xenograft model. This new class of nano-therapeutics shows great promise in the future cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4439. doi:10.1158/1538-7445.AM2011-4439
Abstract 4452: Controlled release complex of cisplatin for mesothelioma: gamma-PGA/Cisplatin complex formulation
Authors: Lee Chunman , Sasai Masao , Sawa Yoshiki
Published: June 2012

Cisplatin is the standard anti-tumor drug for mesothelioma, and other malignant tumors, however acute renal failure due to renal tubule injury is often induced as its adverse event. Hence, the dose of cisplatin is limited by the patient's renal function.

We developed the Cisplatin controlled release complex that released cisplatin steadily, and relieved the adverse event, and examined its characteristics.

1) Slow release of cisplatin from novel complex

Concentration of cisplatin penetrated from the dialysis membrane was measured by ICP atomic emission spectrometer.

- Approximately 4% of cisplatin was released by day1 (initial burst was very low), and 10% of cisplatin was released by day 15, while free cisplatin oozed out from dialysis membrane immediately.

2) Cytotoxicity of novel complex in vitro

Cytotoxicity to murine mesothelioma cell line was measured by MTT assay.

- Over 10 μg/mL of cisplatin, novel complex possessed cytotoxicity, but under 5 μg/mL of novel cisplatin complex did not inhibit the growth of the murine mesothelioma cell line.

3) Bio-distribution of novel cisplatin complex in mice

Novel cisplatin complex was administrated intra-peritoneal cavity, and the cisplatin concentration of each organ was measured at 1, 3, 5, 7 days after the administration.

- Cisplatin of the complex was kept the concentration in the blood after the initial peak concentration, while free cisplatin was disappeared immediately.

Furthermore, cisplatin was found in the concentrated amount in the liver, since novel complex was accumulated in the liver at the early phase as a storage of cisplatin, and cisplatin was released steadily into the bloodstream.

4) Acute toxicity test for mouse

50 mg/kg of novel cisplatin complex was administrated into the peritoneal cavity, and mice were observed.

- All mice were alive with 9 days after cisplatin complex administration.

5) The anti-tumor efficacy of novel cisplatin complex in mesothelioma bearing mice

Each 10 mg/kg of cisplatin formulation was administrated into the peritoneal cavity at five days after subcutaneous inoculation of murine mesothelioma cells.

- On 9 days after cisplatin formulation administration, novel cisplatin complex was more effective than free cisplatin.

Conclusions; We have demonstrated that novel cisplatin complex that releases cisplatin steadily into the bloodstream can be successfully used for the chemotherapy without severe adverse event, despite high dose administration. Although much additional study of this complex is required, the results in this study warrant additional development of this complex for potential investigation into its use in clinical tumor chemotherapy for mesothelioma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4452. doi:10.1158/1538-7445.AM2011-4452
Abstract 4460: Aromatase inhibition by active tamoxifen metabolites
Authors: Lu Wenjie J. , Flockhart David A.
Published: June 2012

Introduction: The mechanism of tamoxifen action in the treatment of breast cancer is believed to be via active metabolites that act as potent antagonists at the estrogen receptors. Despite this, few data have been published that relate the concentrations of these metabolites to their expected clinical effects. Since anti-estrogenic clinical effects may be brought about not only by estrogen antagonism but also by reduced estrogen concentrations, we tested the direct effects of tamoxifen and its active metabolites on aromatase activity.

Methods: The activity of recombinant human aromatase was measured by following the generation of fluorescent metabolite from 7-methoxy-4-trifluoromethylcoumarin (MFC) in microsomal incubations in the presence and absence of multiple concentrations of tamoxifen, endoxifen, N-desmethyl-tamoxifen and 4-hydroxy-tamoxifen. Inhibition of aromatase was determined at enzyme concentrations set at 7.5 nM by measuring the percentage of enzyme activity remaining.

Results: With MFC concentrations at the Km (25 µM), the IC50s for endoxifen and N-desmethyl-tamoxifen were 6.1 µM and 20.7 µM respectively. At concentrations up to 50 µM, no appreciable inhibition by tamoxifen or 4-hydroxy-tamoxifen was observed. Detailed characterization of inhibition by endoxifen and N-desmethyl-tamoxifen across a range of substrate concentrations demonstrated non-competitive kinetics for both inhibitors. The Ki values for endoxifen and N-desmethyl-tamoxifen were 4.0 µM and 15.9 µM respectively. Preincubation of these tamoxifen metabolites with aromatase did not demonstrate any irreversible effect on enzyme activity.

Discussion: Among tamoxifen and its three major metabolites, only endoxifen and N-desmethyl-tamoxifen were found to be potent inhibitors of aromatase. This enzyme is the major source of estrogen in humans, and changes in its activity may thus alter estrogen-regulated physiology. Inhibition by these tamoxifen metabolites may contribute to changes in serum and tissue estrogen concentrations, and may explain in part the variability in bone density, serum lipid concentration, severity of musculoskeletal pain and breast cancer recurrence observed in patients taking tamoxifen. Relationships between tamoxifen metabolite concentrations and clinical outcomes may be complex, and mechanisms that underlie the multiple clinical effects of tamoxifen include the possibility of aromatase inhibition by endoxifen and N-desmethyl-tamoxifen.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4460. doi:10.1158/1538-7445.AM2011-4460
Abstract 4471: Antitumor effects of 5-Aminoimidazole-4-carboxamide-ribonucleoside (AICAR) on thyroid cancer cell lines with BRAF V600E mutation
Authors: Yim Ji Hye , Choi Hyun Jeong , Kim Eui Young , Kim Tae Yong , Kim Won Bae , Jang Sejin , Shong Young Kee
Published: June 2012

Background : Anaplastic thyroid carcinoma is one of the most aggressive human cancers with a median survival of only 6 months. Local surgical tumor debulking and combined with radio-chemotherapy is conventionally used but low success rate urges the search for new therapeutic targets. 5-Aminoimidazole-4-carboxamide-ribonucleoside (AICAR) is an activator of the 5’ AMP-activated protein kinase (AMPK), which plays a role in cellular energy homeostasis. Activated AMPK is inhibits the protein kinase mammalian target of rapamycin, thereby reducing protein translation and suppressing cell growth and cell cycle entry. Recently, AMPK was reported to be mediated by RAF-MEK-ERK pathway in melanoma cells harboring the B-RAF(V600E) mutation.

Methods: We investigated the anti-tumor effect of AICAR on the proliferation of thyroid cancer cell lines with BRAF(V600E) mutation or wild type BRAF. We were to see the effect of AICAR on cell proliferation, apoptosis and cell cycle of thyroid cancer cell and reveal the mechanism of these changes.

Methods: The proliferation of thyroid cancer cell lines with BRAF(V600E) mutations was more significantly inhibited by administration of AICAR in comparison with cell lines with wild type BRAF. The suppressive effect of AICAR on cell proliferation of BRAF(V600E) mutated thyroid cancer cell lines was related with increased phosphorylation of AMPK, S-phase cell cycle arrest, and increased apoptosis. Interestingly, the AICAR suppressed phosphorylation of ERK and p70S6K in B-RAF V600E mutated thyroid cancer cells compared to B-RAF wild type cells.

Conclusion: In BRAF(V600E) mutation harboring thyroid cancer cell lines, AICAR induced AMPK activation resulted in decrease of cell growth, apoptosis, and increased cell cycle arrest via down-regulation of ERK and p70S6K activity. These results suggest that regulation of AMPK activity may be a potential target for cancer therapy in thyroid cancer with BRAF V600E mutation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4471. doi:10.1158/1538-7445.AM2011-4471
Abstract 4491: AZD5363, a novel Akt inhibitor, delays prostate cancer progression by inhibiting androgen-receptor activity
Authors: Lamoureux Francois , Thomas Christian , Crafter Claire , Davies Barry , Gleave Martin E. , Zoubeidi Amina
Published: June 2012

Introduction and Objective: Despite initial response to androgen deprivation therapy, prostate cancer (PCa) inevitably progresses after 3 to 4 years to its castration-resistant state (CRPC). Consequently, there is an urgent need for novel therapeutic agents that can prevent or at least prolong the time to CRPC progression. The phosphoinositide 3-kinase (PI3K)/Akt pathway plays a key role in tumor progression and therefore is an attractive pharmacological target. In this study, we assessed the anti-cancer effects of the novel and selective Akt inhibitor, AZD5363, in vitro and in vivo in PCa.

Methods: LNCaP and C4-2 cells were treated with AZD5363 and submitted to western blot, qRT-PCR and immunofluorescence analysis. AZD5363 was tested for its ability to modulate PSA transactivation by luciferase assay. Cell viability was assessed by crystal violet and cell cycle population by flow cytometry. For in vivo xenograft studies, LNCaP cells were inoculated s.c. in the flank region of athymic nude mice. Mice were castrated and randomly treated with AZD5363 or control by oral gavage. Tumor volume and serum prostate-specific antigen (PSA) were evaluated twice per week.

Results: Here we report that AZD5363 inhibits cell growth in a dose-dependent manner (IC50 ± 200nM) in both LNCaP and C4-2, induces cell apoptosis as measured with PARP cleavage expression, Caspase 3 activity, and increases sub-G1 population (20.2% and 22.2% at 500nM for LNCaP and C4-2 cells, respectively). Interestingly, AZD5363 significantly abrogates androgen-induced PSA transactivation at concentrations > ∼100nM and down-regulates AR expression at concentrations > ∼1μM. These biologic events were accompanied by inhibition of downstream PI3K/Akt signaling. Most important, targeting the Akt-pathway in vivo significantly reduces tumor volume and serum PSA-levels and thereby delays progression to CRPC.

Conclusions: This study reports as a preclinical proof-of-principle that targeting PI3K/Akt pathway with AZD5363 inhibits androgen-dependent PCa progression in vitro and in vivo, using the AR-axis as a pharmacodynamic tool.

This work was supported by AstraZeneca, the Deutsche Forschungsgemeinschaft (German Research Foundation; Grant number: TH 1482/2-1), the Canadian Institutes of Health Research and l'Association pour la Recherche sur le Cancer (France).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4491. doi:10.1158/1538-7445.AM2011-4491
Abstract 4493: Preclinical efficacy of AZD8055, an ATP-competitive mammalian target of rapamycin (mTOR) kinase inhibitor, in vitro in urothelial carcinoma of the bladder
Authors: Lin Kelly Y. , Gupta Gopal N. , Sourbier Carole , Williams Heinric , Guichard Sylvie , Linehan W. Marston , Srinivasan Ramaprasad
Published: June 2012

Mammalian target of rapamycin (mTOR) has been shown to play a key role in energy sensing, cell growth, and cell survival in many cancers. Although alterations of the PI3K/Akt/mTOR pathway are frequent in urothelial carcinoma (UC), the effects of pharmacologic targeting of this pathway have not been systematically evaluated. Selective inhibitors of the mTORC1 component of mTOR have modest activity in renal cell cancer and are currently being evaluated in patients with advanced bladder cancer. Since selective mTORC1 inhibition may lead to feedback activation of Akt through mTORC2, concomitant disruption of mTORC2 activity may result in more complete mTOR blockade and more potent antitumor activity than inhibition of mTORC1 alone. In this study, the efficacy of the dual mTORC1/mTORC2 inhibitor AZD8055 was compared with that of rapamycin in three UC cell lines UMUC-3, TCCSuP and HT-1376. Both AZD8055 and rapamycin were able to downregulate the mTORC1 substrate pS6; however, only AZD8055 was effective in downregulating p4E-BP1, a critical component of cap-dependent translation that is also regulated by mTORC1. AZD8055, but not rapamycin, potently suppressed mTORC2 signaling as evidenced by downregulation of pAKTs473. AZD8055 exhibited potent in vitro antitumor activity against all three bladder cancer cell lines, with IC50s of 15-40nM by the MTT assay, while rapamycin had minimal antitumor activity at these concentrations (IC50 not reached at 1uM). In vivo efficacy of AZD8055 is under evaluation in mouse xenograft models. These data demonstrate that AZD8055 is a potent inhibitor of mTORC2 and a more effective inhibitor of downstream mTORC1 targets than rapamycin. Combined mTORC1/2 kinase inhibition may be superior to selective mTORC1 inhibition, and is worthy of clinical evaluation in urothelial carcinoma of the bladder.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4493. doi:10.1158/1538-7445.AM2011-4493
Abstract 4497: NVP-BEZ235, a dual PI3K/ mTOR inhibitor, may be effective for ovarian clear cell carcinoma cells
Authors: Oishi Tetsuro , Itamochi Hiroaki , Nonaka Michiko , Sato Seiya , Naniwa Jun , Uegaki Kazunori , Sato Shinya , Shimada Muneaki , Terakawa Naoki , Kigawa Junzo , Harada Tasuku
Published: June 2012

[Background] NVP-BEZ235 (BEZ235) is a novel, orally bioavailable imidazoquinoline that potently and reversibly inhibits class 1 PI3K activity by binding to its ATP-binding domain. BEZ235 also binds directly to the mTOR ATP-binding domain and directly inhibits its catalytic activity, thereby inhibiting both TORC1 and TORC2. BEZ235 is currently in phase I testing in patients with solid tumors. There are few reports on the activity of BEZ235 against ovarian carcinoma cells. Ovarian clear cell carcinoma (CCC) has shown the resistance to the standard chemotherapy for epithelial ovarian cancer (EOC). Therefore, patients with CCC have a worse prognosis than those with ovarian serous adenocarcinoma (SAC), which is a dominant subtype in EOC. However, little has been known about genetic alterations in each histologic subtype of EOC. Recently, it has shown that CCC has a high frequency of activating PIK3CA mutations. The purpose of the current study was to determine whether the drug targeting the PI3K-Akt-mTOR pathway suppresses cell proliferation of CCC.

[Material& Methods] We used eight CCC cell lines (KK, OVISE, SMOV-2, KOC-7c, TUOC-1, OVTOKO, OVMANA, and RMG-I) and four SAC cell lines (SHIN-3, TUOS-4, KOC-2s, SK-OV-3) in this study. IC50 to BEZ235 was determined on the basis of the dose-effect curves, using WST-8 assay. Protein expressions of Akt, phospho(p)-Akt(Ser473), mTOR, pmTOR(Ser2448), p70S6K, pp70S6K(Thr389), 4E-BP1, and p4E-BP1(Ser37/46) were examined by western blotting.

[Results] IC50 to BEZ235 for CCC cell lines ranged from 44 to 777 nM and those for SAC cell lines ranged from 989 to 25400 nM. All 8 CCC cell lines showed Akt, mTOR, pmTOR, and p70S6K expressions. Six cell lines showed pAkt expression, and 2 of the 6 cell lines showed both pAkt and p4E-BP1 expressions. Remaining 2 cell lines showed pp70S6K expression. pAkt, p-p70S6K and p4E-BP1 expression in CCC cells were suppressed after exposure to BEZ235 in a dose-dependent manner.

[Conclusion] These results suggest that the PI3K/Akt/mTOR pathway is a potential therapeutic target for CCC and that NVP-BEZ235 is worth exploring as therapeutic agents for CCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4497. doi:10.1158/1538-7445.AM2011-4497
Abstract 4498: HS-104, a novel potent phosphatidylinositol 3-kinase inhibitor, with anticancer activity in human hepatocellular carcinoma
Authors: Hong Soon-Sun , Zheng Hong-Mei , Jung Kyung Hee , Lee Hyunseung , Hong Sang-Won , Li Guang-Yong , Park Byung-Hee , Son Mi-Kwon
Published: June 2012

Phosphatidylinositol 3-kinase (PI3K) has been implicated in cell growth, proliferation, and survival in a variety of diseases including cancer. It is activated by mutational activation of PI3Kα, loss of function of PTEN or activation of receptor tyrosine kinases. A number of PI3K inhibitors have recently been developed for use in cancer therapy. However, there has been no report performed in human hepatocellular carcinoma (HCC), even if the mutation of PI3Ka in HCC have been reported as 6.0∼35.6%. In this study we investigated the effect of HS-104, a novel phosphatidylinositol 3-kinase inhibitor on the proliferation, apoptosis, angiogenesis of HCC cells as well as in vivo mouse xenograft model bearing Huh-7 HCC cells. HS-104 inhibited PI3Ka activity more than LY294002 (a traditional PI3K inhibitor), and it suppressed the phosphorylation of Akt and mTOR in downstream of PI3K in a dose dependent manner. The growth of HCC cells (Huh-7, HepG2, Hep3B) was inhibited by HS-104 treatment in a dose-dependent manner as sorafenib did. Interestingly HS-104 didn't affect the normal liver cell line (HL-7702), while sorafenib showed cytotoxicity at high concentrations. Also, its induction of apoptosis was found by the increase in the proportion of sub-G1 apoptotic cells of 20% at a dose of 10 uM, and the increase in the expressions of cleaved PARP and caspase-3 as well as the decrease in that of bcl-2 in Huh-7 cells. Its induction of apoptosis was confirmed by DNA fragmentation as well as DAPI and TUNEL staining. In addition, we found that HS-104 decreased the expression of hypoxia-inducible factor (HIF-1α), vascular endothelial growth factor (VEGF), and the tube formation and migration of human umbilical vein endothelial cells (HUVECs) in a dose dependent manner, which were confirmed by Matrigel plug assay performed in BALB/c nude mouse. In addition, HS-104 administration (10 mg/kg) for two weeks significantly suppressed the growth of liver cancer in mouse xenograft model using Huh-7 cells, where its induction of apoptosis and anti-angiogenesis was confirmed by immunohistochemistry assay for tumor tissues. Taken together, these results suggest that HS-104 could be used as a drug for the treatment of human hepatoma cells by the mechanism of apoptosis and anti-angiogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4498. doi:10.1158/1538-7445.AM2011-4498
Abstract 4518: Effects of a novel small molecule inhibitor of Wnt signal pathway, CWP232291, on primary tumor cells from patients with malignant hematologic diseases
Authors: Kim Sung-Doo , Byun Young-Hee , Hur Eun-Hye , Oh Se-Woong , Lee Jong Heun , Goo Bon-Kwan , Lee Sung-Sook , Jung Kyung-Yun , Lee Kyoo-Hyung , Lee Jung-Hee , Kim Dae-Young , Choi Yunsuk , Lee Je-Hwan
Published: June 2012

Background: Aberrant activation of Wnt signaling has been implicated in the pathogenesis of hematologic malignancies. CWP232291 is a novel small molecule that inhibits Wnt signaling through promotion of beta-catenin degradation. In vitro and in vivo anti-tumor activities of CWP232291 were demonstrated in previous studies using hematologic cancer cell lines (J.Y.C. 2010 AACR, LB-176). Here we report the effects of CWP232291 on primary tumor cells from patients with malignant hematologic diseases.

Materials and methods: We performed cell viability assay using luminescent-based CellTiter Glo system to determine in vitro growth inhibitory activities in bone marrow mononuclear cells of healthy volunteers and in primary tumor cells collected from bone marrow of the patients with acute myeloid leukemia (AML) and B-cell neoplasms (B-cell non-Hodgkin lymphoma [B-NHL] and multiple myeloma [MM]). Western blot assay was done for changes of intracellular beta-catenin levels after the treatment of CWP232291.

Summary of results: CWP232291 showed little effects on normal bone marrow cells, whereas it exerted potent cytotoxicities in a significant proportion of the patients’ samples (8 of 13 AML patients, 2 of 3 B-NHL patients, and 2 of 4 MM patients). The cytotoxic effects of CWP232291 at sub-micromolar levels were more potent than those of anti-leukemic cytotoxic agents such as cytarabine, daunorubicin, or doxorubicin. All of the tumor samples from the AML patients with t(8;21) (n=3), trisomy 8 (n=3), or MLL translocations (n=1) were sensitive to CWP232291. Baseline intracellular beta-catenin levels were elevated in both B-NHL patients’ samples that were sensitive to CWP232291 and the beta-catenin levels decreased after the treatment with CWP232291.

Conclusion: Our data from primary patients’ samples provide a rationale for exploring the clinical activities of CWP232291 in the treatment of patients with hematologic malignancies, especially AML and B-cell neoplasms.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4518. doi:10.1158/1538-7445.AM2011-4518
Abstract 4540: Follicle-stimulating hormone (FSH) enhances the proliferation of epithelial ovarian cancer cells by activating transient receptor potential channel C3 (TRPC3)
Authors: Tao Xiang , Jin Hongyan , Bast Robert C. , Liu Yingtao , Yu Yinhua , Feng Youji
Published: June 2012

At present, epithelial ovarian cancer is the leading killer among all gynecological malignancies. Despite much research, development of this neoplasm is still not fully understood. The five-year survival rate for this disease still remains about 30%. Recent studies suggest that follicle-stimulating hormone (FSH) may play a major role in ovarian epithelial carcinogenesis. Our group has demonstrated that FSH stimulates the proliferation and invasion of ovarian cancer cells, inhibits apoptosis, and facilitates neovascularization by increasing vascular endothelial growth factor (VEGF) expression. To understand the mechanisms by which FSH stimulates ovarian cancer growth, we have performed gene expression arrays and confirmed changes in protein expression by Western blots. Interestingly, we found that FSH stimulation enhances expression of transient receptor potential channel C3 (TRPC3) at both mRNA and protein levels. Silencing TRPC3 expression by siRNA inhibited the ability of FSH to stimulate proliferation of ovarian cancer cell lines and to block apoptosis. TRPC channels are nonselective cation channels with permeability to Ca2+. Increases in cytosolic free Ca2+ can promote different physiological changes including cell growth, differentiation and death. TRPC3 is one of 7 TRPC family members. Our previous work has shown that TRPC3 contributes to the progression of human ovarian cancer. TRPC3 protein levels in human ovarian cancer specimens were greatly increased relative to those in normal ovarian specimens. Downregulating TRPC3 expression led to reduced proliferation, suppression of epidermal growth factor-induced Ca2+ influx, and decreased growth of xenografts. In this study, we further explored the interaction of FSH-TRPC3. FSH stimulation was associated with upregulation of TRPC3 levels and translocation of TRPC3 from the cytoplasm to cell membrane, facilitating the influx of Ca2+ after treatment with a TRPC3 specific agonist. Knocking down TRPC3 abrogated Akt/PKB phosphorylation by FSH stimulation, leading to decreased expression of down-stream effectors including survivin, HIF1α and VEGF. Our findings indicate that TRPC3 plays a significant role in the tumor-stimulating activity of FSH and could be a potential therapeutic target of ovarian cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4540. doi:10.1158/1538-7445.AM2011-4540
Abstract 4552: Naturally occurring osmolyte, trehalose induces a functionally active conformation in an intrinsically disordered transactivation function domain (AF1) of the Glucocorticoid Receptor
Authors: Khan Shagufta H. , Arnott John A. , Atamna Hani , Ahmad Nihal , Kumar Raj
Published: June 2012

Due to the ability of glucocorticoids to prevent the growth and to cause apoptotic death of malignant cells, they are a mainstay of therapy for many lymphomas and leukemias. Glucocorticoid receptor (GR) mediates the biological effects of glucocorticoids at the level of gene regulation. To initiate transcription of target gene(s), GR interacts with its response element DNA, and/or with various coregulatory proteins. However, specific interaction surfaces of GR with its coregulators are not well understood. Consequently, precisely how transcription is regulated by GR is largely unknown. This is due, in part, to the lack of information about GR's major transactivation function region, AF1 located in the N-terminal domain. The major obstacle in determining the structure of AF1 has been due to its intrinsically disordered (ID) conformation, frequently found in the activation domains of many transcription factors, and it is believed that ID nature of these activation domains promote molecular recognition by creating large interaction surfaces suitable for interactions with their specific protein binding partners, which is a critical component of gene regulation by transcription factors. It has been hypothesized that conditional folding of these activation domains may be a prerequisite for their efficient interaction with specific coregulatory proteins, and subsequent transcriptional activity leading to the regulation of target gene(s). In this study, we tested whether a naturally occurring osmolyte, trehalose can promote functionally ordered conformation in the GR's major activation function domain, AF1, which is found to exist as an ID protein, and requires an efficient interaction with coregulatory proteins for optimal activity. Our data show that trehalose induces an ordered conformation in AF1 such that its interaction with steroid receptor coactivator-1 (SRC-1), a critical coregulator of glucocorticoid receptor's activity, is greatly enhanced. Our results may provide a mechanism for cell-type specificity of the effects of GR in gene regulation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4552. doi:10.1158/1538-7445.AM2011-4552
Abstract 4562: Superior targeting of the human epidermal growth factor receptor 2 (HER-2) with recombinant monoclonal antibody mixtures
Authors: Pedersen Mikkel W. , Jacobsen Helle J. , Poulsen Thomas T. , Meijer Per J. , Kragh Michael
Published: June 2012

Human epidermal growth factor receptor 2 (HER2) is involved in development and maintenance of malignant phenotypes of several human cancers and therefore represent an attractive therapeutic target. Trastuzumab is currently the only anti-HER2 antibody approved for treatment of human cancers and although succesful more efficacious treatments are warranted. Mixtures of recombinant monoclonal antibodies are promising candidates as the next generation of antibody therapeutics due to their multipotent activities.

The aim of the present study was to identify mixtures of anti-HER2 antibodies with superior activity to existing monoclonal antibodies. Anti-HER2 antibodies were raised in mice by immunizations with HER-2 in different antigen presenting formats. A large antibody repertoire consisting of approximately 150 unique anti-HER-2 antibodies was cloned from the mice using the mSymplex™ technology. Based on a thorough sequence and binding analysis, 40 antibodies were selected for functional evaluation. The 40 antibodies were tested as individual antibodies and in mixtures of two and three for the ability to inhibit the growth of four human cancer cell lines using a standard viability assay. In total, more than 1300 mixtures were evaluated for ability to inhibit growth of the four cell lines. The 20 mixtures with the highest levels of growth inhibition were further characterized with regard to potency (IC50) and ability to engage in ADCC and CDC. The results demonstrated that HER2 mixtures were superior to trastuzumab, pertuzumab and the mixture of the two at inhibiting the growth of seven of the 10 cell lines investigated. Interestingly, the mixtures also inhibited the growth of the trastuzumab resistant breast cancer cell line HCC202, reflecting the differentiated mechanisms of anti-HER2 antibody mixtures. In vivo, anti-HER2 mixtures had superior activity compared to the monoclonal anti-HER2 antibody trastuzumab in two models of human gastric cancer. Based on these results, a candidate mixture was selected and referred to as Sym005.

In conclusion, these data demonstrate that the novel antibody mixture Sym005 has a unique set of HER2 inhibitory mechanisms, which translates into superior anti-cancer activity in HER2-positive tumor xenografts. Furthermore, the results provide a clear rationale for evaluation of Sym005 in clinical trials on patients with HER2 positive tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4562. doi:10.1158/1538-7445.AM2011-4562
Abstract 4566: AGS-1C4D4: A fully human anti-PSCA antibody inhibits tumor formation and metastasis in orthotopic models of pancreatic cancer
Authors: Navas Tony , Haubrich Trisha , Llamas Jenny , Avina Hector , Chunying Zhang , Perez Myra , Capo Linnette , Leavitt Monica , Chen Rou-Yu , Verlinsky Alla , An Zili , Secrest James , Ganguly Nandini , Satpayev Daulet , Morrison Karen , Raitano Art , Challita-Eid Pia , Jia Xiao-Chi , Morrison Kendall , Hartford Alan , Stover David
Published: June 2012

Prostate stem cell antigen (PSCA) is a cysteine-rich cell surface glycoprotein expressed in about 50% of pancreatic and prostate cancers. AGS-PSCA is a hybridoma-derived fully human IgG1κ monoclonal antibody (MAb) targeting PSCA previously reported to have anti-tumor efficacy in prostate and pancreatic tumor models. AGS-1C4D4 is a CHO-derived antibody generated from the same gene as AGS-PSCA, with similar specificity and binding affinity to PSCA (Kd = 2.0 × 10-10M). Since hybridoma and CHO-derived MAbs displayed disparate glycosylation patterns by mass spectroscopy, we further evaluated their MAb effector functions. AGS-1C4D4 was found to have more potent ADCC activity in vitro on PSCA-expressing pancreatic cell lines, HPAC and Panc0203, using human PBMCs from multiple normal donors. However, both MAbs were similarly effective in mediating CDC on PSCA-expressing recombinant B300.19 cells. Deglycosylation greatly reduced the relative ADCC and CDC activities of both MAbs compared to their intact versions. Additional studies to elucidate the role of the effector functions of AGS-1C4D4 are currently being conducted in vivo using intact and deglycosylated MAbs and will be presented. While neither intact antibody had any direct cytotoxic activity on HPAC cells in vitro, both MAbs significantly inhibited tumor formation, local invasion and metastases to distant sites in orthotopic HPAC xenograft tumor models in vivo. In addition, AGS-1C4D4 significantly inhibited the growth and metastasis of established orthotopic HPAC tumors in combination with Gemcitabine. AGS-1C4D4 is currently being evaluated in a Phase 2 clinical study for pancreatic cancer in combination with Gemcitabine.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4566. doi:10.1158/1538-7445.AM2011-4566
Abstract 4578: Nonclinical safety assessment of VX15/2503: A humanized IgG4 monoclonal antibody to sema4D
Authors: Cornelius Chad A. , Fisher Terrence L. , Winter Laurie A. , Seils Jennifer , Reilly Christine A. , Jonason Alan S. , Smith Ernest , Watkins Raymond , Zauderer Maurice , Leonard John E.
Published: June 2012

VX15/2503 is a humanized IgG4 monoclonal antibody that binds with approximately 3 nM affinity to Semaphorin 4D (SEMA4D, CD100). SEMA4D is an important mediator of axonal growth cone guidance, vascular development, angiogenesis, and T cell and B cell activation. SEMA4D is found predominantly as a 150 kDa transmembrane protein on lymphocytes and as a 240 kDa, homodimeric, soluble form of the protein. VX15/2503 or its murine progenitor (MAb 67-2) suppressed tumor growth and angiogenesis in syngeneic, xenograft and transgenic tumor models. Toxicology and pharmacology studies of VX15/2503 were performed in Sprague-Dawley rats and cynomolgus macaques using single or five weekly intravenous injections. Toxicology profiles were similar for both species in both studies. Single dose studies employed doses of between 0.01 and 100 mg/kg; repeat dose studies evaluated 10, 30 and 100 mg/kg. No adverse histopathologic or clinical effects were noted in either species injected with doses up to 100 mg/kg. Appetence, body weights, serum chemistry and ophthalmologic factors were also unaffected, as were primate ECG results. Thus the NOAEL was established at 100 mg/kg for both species. Partial to complete T cell associated SEMA4D saturation was observed in all animals across the dose ranges evaluated and SEMA4D saturation was dose dependent. Single dose animals that reached a VX15/2503 serum concentration of ≥2 µg/mL exhibited transient complete T cell saturation. Prolonged saturation occurred at the 100 mg/kg dose level. Repeat dose animals in the 100 mg/kg dose group were on average at least 20% saturated for 134 and 169 days in rats and cynomolgus macaques, respectively. Single dose VX15/2503 half-life values increased with dose and varied from 27 to 246 hours in rats; similar results were obtained from the primate single dose study. Repeat dose Cmax and AUC (exposure) values were higher in both species than those from the single dose studies and steady-state was achieved after the fourth dose. Anti-VX15/2503 responses were detected in the sera of most animals in both studies. Human tissue arrays incubated with VX15/2503 showed diverse distribution of SEMA4D on resident or itinerant lymphocytes in lymphoid tissues as well as in sections of brain, lung and endometrium. Based on these results VX15/2503 was selected for clinical development in oncology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4578. doi:10.1158/1538-7445.AM2011-4578
Abstract 4587: Identification of a monoclonal antibody to treat HCC xenografts with EGFRvIII expression
Authors: Li Zonghai , Jiang Hua , Wang Huamao , Shi Bizhi
Published: June 2012

Purposes:To identify monoclonal antibodies targeting Epidermal Growth Factor Receptor Variant III (EGFRvIII) and their anti-tumor effect on Hepatocellular carcinoma (HCC) with EGFRvIII expression. Procedures: Hybridoma technology was used to prepare monoclonal antibody recognizing EGFRvIII. Anti-tumor effects of several hybridoma clones were examined on HCC xenografts with EGFRvIII expression. Monoclonal antibody with highest growth-suppression effect on HCC was selected. Binding specificity of the antibody was tested by FACS assay. The targeting ability of this antibody was tested by injected the cyanin 5.5 labeled antibody into mice carrying EGFRvIII positive and negative xenografts. Findings: Among the tested monoclonal antibodies, mAb 12H23 has the highest tumor-suppression effect on HCC with EGFRvIII expression. mAb 12H23 bind preferentially to HCC cells with EGFRvIII expression. Cy5.5 labeled mAb 12H23 can significantly accumulate into EGFRvIII positive tumors but not the negative tumors. Conclusion: These data indicate mAb 12H23 is a potential biotherapeutic agent for treating HCC with EGFRvIII expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4587. doi:10.1158/1538-7445.AM2011-4587
Abstract 4609: Prevention of pancreatic cancer using novel crocetin compound
Authors: Aurora Chetna , Gutheil William G. , Reed Gregory , Anant Shrikant , Dhar Animesh
Published: June 2012

Pancreatic cancer is one of the most lethal malignancies in humans and there is no effective conventional treatment available for the cure of patients with pancreatic cancer. Great demand of new effective drugs and alternative approaches has led to studies evaluating possible anti-cancer agents in fruits, vegetables, herbs and spices. Crocetin, a carotenoid molecule isolated from saffron, has been demonstrated recently by our laboratory that crocetin treatment has potent antimitotic effects on both in vitro and in vivo pancreatic cancer models. Commercial crocetin is a mixture of crocetin esters and recently, novel crocetin compound and its esters are also fractionated from commercial crocetin by us using prepartory HPLC and LC/MS.The aim of this work is to identify most potent fractions separted from crude or commecial crocetin following the signaling mechanisms, responsible for inducing cellular proliferation and tumorigenesis of pancreatic adenocarcinoma. One of the fractions separated from crude crocetin by preparative HPLC, and identified using LC/MS and NMR as crocetinic acid, markedly regressed the proliferation and increased apoptosis in pancreatic cancer cells. Growth related signaling pathways such as epidermal growth factor receptor (EGFR) and its down-stream signaling molecule, Akt phosphorylation were significantly altered by novel crocetin compound derived from crude crocetin. It has also been demonstrated that novel crocetin compound altered histone deacetylase (HDAC) and its substrate acetyl histone H3 Lysine14 that indicates histone modifications by inhibition of deacetylation. Apoptosis was significantly stimulated as indicated by Bax/Bcl-2 ratio by treatment with purified crocetin. Purified crocetin compound showed significant anti-tumorigenic effect at lower doses than commercial or crude crocetin using proliferation and apoptosis as markers. Crocetin can be used as chemopreventive agent for pancreatic cancer in future.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4609. doi:10.1158/1538-7445.AM2011-4609
Abstract 4612: Cell-type dependent responses to selenium and knockdown of SBP2
Authors: Li Jin , Suraokar Milind B. , Tsavachidou Dimitra , Menter David G. , Kim Jeri
Published: June 2012

Selenium is a trace element essential for human health. Evidence from previous epidemiologic studies and clinical trials suggested that selenium is associated with prostate cancer prevention, but its failure in the Selenium and Vitamin E Cancer Prevention Trial (SELECT) to reduce prostate cancer incidence diminished its promise. The question of whether some patients could benefit from selenium supplementation while others might not demands a clearer understanding of selenium's mechanisms of action. One of the ways in which selenium acts as a chemopreventive agent is through incorporation into selenoproteins, which are antioxidant enzymes required to maintain redox homeostasis; however, selenoproteins’ large number and redundant functions make analyzing their effects on cellular functions difficult. Therefore, we recently targeted selenocysteine insertion sequence-binding protein 2 (SBP2), required for selenoprotein synthesis; knocked down SBP2 expression in different cell lines; and examined the effect on cell survival, cell cycle, and cell survival pathways. We found that knocking down SBP2 resulted in apoptosis in NIH/3T3 and HEK-293 cells, especially in the presence of H2O2. Interestingly abrogation of SBP2 function affected the level of p21 protein in a cell type-specific manner. Additionally, sodium selenite or seleno-methionine treatment led to distinct changes in p21 and p53 protein status in HEK-293, LNCaP, and DU145 cells. Molecular effects induced by knocking down SBP2 were cell-type dependent. Further studies involving a combinational approach are expected to contribute to understanding how selenium and selenoproteins mediate chemopreventive effects in prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4612. doi:10.1158/1538-7445.AM2011-4612
Abstract 4616: A hexane extract of American ginseng suppresses mouse colitis
Authors: Poudyal Deepak , Windust Anthony , Davis Tia , Chumanevich Alexander A. , Chumanevich Alena , Nagarkatti Mitzi , Nagarkatti Prakash S. , Wargovich Michael J. , Hofseth Lorne J.
Published: June 2012

Ulcerative colitis (UC) is a dynamic, idiopathic, chronic inflammatory condition associated with a high colon cancer risk. We have previously shown that American Ginseng (AG) extract prevents and treats colitis. The aim of this study was to better understand the components of American ginseng that suppress colitis. In this study we show that among five different fractions of AG (Butanol, Hexane, Ethylacetate, Dicholoromethane and Water), the Hexane fraction of American ginseng (HAG) has the most effective anti-oxidation and pro-apoptotic effect. This effect of HAG was shown in a mouse macrophage cell line (ANA-1 cells) and in an ex-vivo model (activated primary effector T cells, CD4+/CD25- T cells). Importantly, compared with the entire AG extract, the HAG was more potent in treating colitis in a dextran sulfate sodium (DSS) mouse model. Results from this study move us closer to understanding the molecular components of AG that suppress colitis, and perhaps prevent colon cancer associated with colitis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4616. doi:10.1158/1538-7445.AM2011-4616