bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4326: Responses of a direct in vivo xenograft model of melanoma to MKK1/2 inhibitor
Authors: Sethuraman Jyothi , Luo Yuchun , Sung Hyojin , Fujita Mayumi , Ahn Natalie G.
Published: June 2012

Metastatic melanoma is the most aggressive form of skin cancer, accounting for 80% of skin cancer deaths due to its high resistance to conventional chemotherapy. Recent studies have shown that metastatic melanomas are susceptible to targeted therapeutics using inhibitors of BRAF or MKK1/2 protein kinases. Here, we study the effect of the MKK1/2 inhibitor, AZD6244, on a direct in vivo xenograft model of melanoma, as well as the effect of MKK1/2 inhibitors, AZD6244 and CI1040 and the BRAF-V600E inhibitor, PLX4720, on established cell lines and cells from direct in vivo xenografts grown in 2D culture. Treatment with CI1040 elicited strong cell death responses in six of nine established melanoma cell lines, reaching 65-80% apoptosis after 48 h. Xenografts of established melanoma cell lines were also responsive to MKK1/2 inhibitor, showing suppressed tumor growth in animals treated with CI1040 in the presence or absence of temozolomide. Likewise, MKK1/2 inhibitor suppressed tumor growth in a direct in vivo xenograft model of melanoma, where tumors harboring BRAF-V600E mutations showed complete growth inhibition in response to AZD6244. One tumor harboring BRAF-WT showed partial growth suppression with AZD6244 alone, but complete suppression was achieved when AZD6244 was combined with temozolomide. Unexpectedly, cells derived from direct in vivo xenografts and grown in 2D culture showed relatively low apoptotic responses when treated with MKK1/2 or BRAF inhibitors. The results suggest that tumor and cell growth conditions might influence mechanisms underlying the oncogene addiction response to constitutive activation of the BRAF/MKK/ERK pathway.

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 4326. doi:10.1158/1538-7445.AM2011-4326
Abstract 4337: Interactions of brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY) systems in neuroblastoma: New insight into mechanisms of BDNF's pro-survival effects
Authors: Czarnecka Magdalena K. , Kuan-Celarier Anna , Lu Congyi , Everhart Lindsay , Kitlinska Joanna
Published: June 2012

BDNF is a known survival factor for neuroblastomas (NB) and is implicated in the development of their chemoresistance. NPY, on the other hand, is a sympathetic neurotransmitter, which is highly released from NB tumors. The elevated NPY levels in NB patients are associated with poor clinical outcome, which is in agreement with its Y2 receptor (Y2R)-mediated proliferative effects on NB cells and pro-angiogenic activities. In normal sympathetic neurons, BDNF has been shown to up-regulate NPY expression, while NPY itself has been implicated in promoting their survival. Therefore, we sought to determine if similar interactions between BDNF and NPY systems occur in NB cells.

We have found that BDNF up-regulates expression of both NPY and its Y2Rs in native NB cells, as well as SH-SY5Y cells transfected with BDNF receptor – TrkB (SH-SY5Y/TrkB). However, even more dramatically, BDNF induces expression of another NPY receptor – Y5R, which is not detectable in most NB cell lines under basal conditions. In agreement with this, expression of Y5Rs correlated with TrkB and BDNF expression in human NB samples. In addition, Y5R seems to be directly involved in BDNF signaling. In SH-SY5Y/TrkB cells, BDNF-induced activation of p44/42 MAPK is significantly reduced by selective Y5R antagonist, CGP 71683, but not by Y2R antagonist, BIIE 0246. Interestingly, the Y5R antagonist had no effect on Akt activation stimulated by BDNF. Thus, these data suggest specific cross-talk between TrkB and Y5R signaling leading to activation of p44/42 MAPK pathway.

Since BDNF is a known survival factor for NB cells, we sought to determine if pro-survival activity of BDNF is mediated by NPY. Chemotherapy was found to up-regulate the expression of both BDNF and NPY systems. This was further supported by elevated expression of NPY and its Y5Rs in cells derived from a chemotherapy-treated patient (CHLA-20, SMS-KANR) as compared to cells derived from primary tumors of the same patient (CHLA-15, SMS-KAN). In the functional studies, NPY mimicked the anti-apoptotic effect of BDNF in chemotherapy-treated NB cells. Moreover, as observed with MAPK activation, blocking Y5Rs, but not Y2Rs, reduced the pro-survival activity of BDNF in these cells.

In summary, while Y2R is the main NPY R constitutively expressed in NBs and responsible for its proliferative effect, expression of Y5R is induced by BDNF and chemotherapy, subsequently enhancing the pro-survival functions of NPY. These anti-apoptotic actions of NPY can additionally augment the known direct survival effects of BDNF.

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 4337. doi:10.1158/1538-7445.AM2011-4337
Abstract 4369: Eradication of chemotherapy-resistant CD44+ human ovarian cancer stem cells in C.B-17/SCID mice by intraperitoneal administration of Clostridium Perfringens Enterotoxin (CPE)
Authors: Santin Alessandro D. , Cocco Emiliano , Bellone Stefania , Casagrande Francesca , Bellone Marta , Todeschini Paola , Varughese Joyce , Silasi Dan-Arin , Azodi Masoud , Rutherford Thomas , Schwartz Peter , Pecorelli Sergio
Published: June 2012

Emerging evidence has suggested that the capability to sustain tumor formation, growth and resistance to chemotherapy in ovarian as well as other human malignancies, exclusively resides in a small proportion of tumor cells termed cancer stem cells (CSC). If this hypothesis is correct, different therapeutic approaches need to be considered for the elimination of the cancer stem cell population. During the characterization of CD44+ ovarian CSC we found a high expression of the genes encoding for claudin-4. Because this tight junction protein is the natural high affinity receptor for the cytotoxic effect of Clostridium Perfringens Enterotoxin (CPE), we have extensively investigated the sensitivity of ovarian CSC to CPE treatment in vitro and in vivo. We report that CD44+ ovarian CSC expressed claudin-4 gene at significantly higher levels when compared to matched autologous CD44- ovarian cancer cells and, regardless of their higher resistance to chemotherapeutic agents, died within 1 hr to the exposure to 1.0 μg/mL of CPE in vitro. Importantly, multiple intraperitoneal (i.p.) administration of sublethal doses of CPE in SCID mouse harboring established xenografts of chemotherapy resistant CD44+ ovarian CSC had a significant inhibitory effect on tumor progression leading to the cure and/or long term survival of all treated animals (p = 0.001). CPE may represent an unconventional, potentially highly effective strategy to eradicate chemotherapy resistant CSC.

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 4369. doi:10.1158/1538-7445.AM2011-4369
Abstract 437: Longitudinal imaging of the pancreatic cancer tumor microenvironment
Authors: Momiyama Masashi , Suetsugu Atsushi , Tome Yasunori , Bouvet Michael , Chishima Takashi , Endo Itaru , Hoffman Robert M.
Published: June 2012

In order to visualize the tumor microenvironment (TME) in pancreatic cancer, the MIA PaCa-2 human pancreatic cancer cell line, expressing red fluorescent protein (RFP), was orthotopically transplanted in nude mice or transgenic mice expressing nestin-GFP. In the nestin-GFP mouse, nascent blood vessels which vascularize the growing tumor are labeled with GFP. A peritoneal flap was made on the left flank of nude mice. The tail of the pancreas was fixed on the peritoneal flap in order to image tumors on the pancreas directly and repeatedly. Color-coded imaging was observed with the Olympus OV100 Small Animal Imaging System under high magnification. The growing tumor expressing RFP, nascent blood vessels expressing GFP, and the interaction between RFP cancer cells and GFP macrophages were observed in real time. Imaging could be carried out until the tumor exceeded the size of the flap which occurred at approximately 21 days after tumor implantation. This mouse model for imaging in the pancreas TME will enable a deeper understanding of tumor-host interaction pancreatic cancer and make it possible to study new therapeutics for pancreatic 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 437. doi:10.1158/1538-7445.AM2011-437
Abstract 4373: Color-coded real-time imaging of the interaction of mesenchymal stem cells and cancer cells
Authors: Ke James , Suetsugu Atsushi , Lee Oscar K. , Hoffman Robert M.
Published: June 2012

Mesenchymal stem cells (MSC) have been reported to promote tumor growth and metastasis. Through paracrine effects, cytokines such as TGFβ or CCL5 produced by MSC play a role in modulating cancer cell behavior. However, the interaction between MSCs and cancer cells is not only via cytokines but involves physical contact as well. In this study, using GFP mesenchymal stem cells and RFP murine mammary cancer cells, the interaction between these cells types was imaged in vivo and vitro. Murine MSCs were isolated from GFP transgenic mice and 4T1 murine mammary cancer cells expressed RFP. Cells were co-cultured in vitro or co-implanted into the mouse mammary fat pad. Cell movement and distribution were recorded with fluorescence video microscopy. 4T1 cells had an epithelial shape and moved toward each other to form clusters when cultured alone. In contrast, 4T1 cells showed a stretched, spindle like morphology when interacting with MSCs. In vivo imaging with the Olympus OV-100 or IV-100, clearly visualized GFP-MSC and RFP-4T1 cells within tumors. When co-injected with MSCs, as few as 5 4T1-RFP cells could form a tumor but could not form tumors at the low cell number without MSCs. The results demonstrate that MSCs have a powerful effect on breast cancer cells.

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 4373. doi:10.1158/1538-7445.AM2011-4373
Abstract 4374: Identification and characterization of active components of antrodia camphorata mycelia on targeting cancer initiating cell
Authors: Chang Ching-Wen , Lo Jeng-Fan
Published: June 2012

Background: Cancer initiating cells (CICs) represent a rare subpopulation of cancer cells, which are responsible for tumor growth. Cancer initiating cells such as oral cancer-cancer initiating cells (OC-CICs), are often resistant to either radiotherapy or chemotherapy. Therefore, screening and development for drug candidates that target OC-CICs specifically will benefit for future oral cancer therapy.

Methods: First, we used the in vitro cell-based ALDH activity assay system, which has been demonstrated as a CICs marker, to screen for the active components from purified compounds of Antrodia Camphorata Mycelia extract (ACME), which can target OC-CICs. The growth inhibition and cell differentiation ability of OC-CICs treated with purified compounds from ACME were evaluated. In addition, the self-renewal ability and stemness properties of ACMEs treated OC-CICs were examined. Furthermore, xenotransplantation assay was applied to test the tumorigenicity of OC-CICs treated with isolated ACMEs. Finally, we investigated the molecular mechanisms mediated by ACME treatment on OC-CICs.

Results: Herein, we first found out that an ACME's purified components, CH-190-WS-D, significantly downregulated the ALDH activity of oral cancer cells. Treatment of CH-190-WS-D significantly induced cell death and enhanced the differentiation capability of OC-CICs but not the major population of oral cancer cells. Moreover, we found that treatment of CH-190-WS-D reduced the self-renewal ability and stemness properties of OC-CICs. The in vitro tumorigenic properties, including cell migration and anchorage independent growth of OC-CICs, were lessened by CH-190-WS-D treatment. Furthermore, treatment of CH-190-WS-D suppressed tumor growth of nude mice bearing xenografts. Finally, treatment of CH-190-WS-D results in down-regulation of PI3K/AKT/mTOR molecular mechanisms which play important roles in CICs.

Conclusion: Our studies reveal the ACME's purified components can reduce stemness properties and tumorigenicity of OC-CICs. Eventually, we can discover drug candidates from ACME's purified components for alternative oral 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 4374. doi:10.1158/1538-7445.AM2011-4374
Abstract 4376: Acquired cancer stem cell like features through Oct4 mediated dedifferentiation
Authors: Kumar Suresh M.K , Liu Shujing , Lu Hezhe , Yang Ruifeng , Pushparajan Anitha , Wei Guo , Xu Xiaowei
Published: June 2012

There is enormous interest to target cancer stem cells (CSCs) for clinical treatment. CSCs are highly tumorigenic and resistant to chemotherapy. Nevertheless, there is still controversial surrounding CSCs and the origin of CSCs remains elusive. In this study, we showed that expression of Oct4 gene or transmembrane delivery of Oct4 protein promoted dedifferentiation of melanoma cells to CSC-like cells. The dedifferentiated melanoma cells displayed dramatic morphological changes and acquired the ability to form tumor spheroids. They showed markedly increased resistance to chemotherapeutic agents and hypoxic injury. In the subcutaneous xenograft or tail vein injection assays, these cells had significantly increased tumorigenic capacity. The dedifferentiated melanoma cells showed significantly decreased expression of melanocytic markers and acquired many features associated with CSCs such as multipotent differentiation capacity and expression of melanoma CSC markers such as ABCB5 and CD271. Oct4 induced dedifferentiation was associated with endogenous Oct4 promoter activity, expression of Nanog and Klf4, and global gene expression changes that enriched for transcription factors. Furthermore, ShRNA mediated knockdown of Oct4 in dedifferentiated cells led to diminished CSC phenotypes. Oct4 expression was detectable in a subpopulation of tumor cells in clinical melanoma tissues. Our results indicate that CSC phenotype is dynamic and may be acquired through dedifferentiation and Oct4 is a positive regulator of tumor dedifferentiation. These data suggest Oct4 mediated differentiation may play an important role during tumor progression.

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 4376. doi:10.1158/1538-7445.AM2011-4376
Abstract 4377: Proper migration of mammalian prostate stem cells to the area of the prostate gland in zebrafish
Authors: Jagadeeswaran Pudur , Radhakrishnan Uvaraj P. , Kim Seongcheol , Rajpurohit Surendra Kumar , Xie Daxing , Hsieh Jer-Tsong
Published: June 2012

Androgen independent prostate cancer contributes to the maximum mortality in prostate cancer patients. One school of thought is that these cancer cells arise in metastatic sites where the cancer cells take on stem cell behavior similar to the stem cell behavior observed in normal prostate gland. Thus, understanding prostate gland stem cells and their migration pattern may provide clues to their biology which may have applications in their migration during metastasis. To understand the migration of mammalian prostate stem cells we used zebrafish as a model. We have previously established zebrafish as a model to study prostate cancer because we found the presence of prostate-like- cells around the zebrafish testes. In this abstract we further characterized location of normal prostate-like cells. We found that they are present in the anterior and posterior aspects of testes. Furthermore, we cloned 2 kb prostate specific antigen promoter into pDsRed 2.1 plasmid and injected this plasmid DNA into single cell-stage zebrafish embryo with I-Sce1 to enhance transgenesis frequency and germline transmission. Larvae injected with PSA promoter-DSRed 2 constructs were screened three days post fertilization (dpf) for the expression of red fluorescence, which was observed in bilaterally arranged spots in gonads. We then used 5 dpf zebrafish larvae and IV-injected cells from four different cell lines expressing either GFP or RFP: two with stem cell phenotype RWPE-1-shDAB2IP (GFP), PZ-HPV7-shDAB2IP (GFP), and two as controls RWPE-1-shCon (GFP) and PC-3 (RFP). After two days, microscopy for green or red fluorescence signal revealed RWPE-1-shDAB2IP and PZ-HPV7-shDAB2IP cells bilaterally migrated to the yolk, i.e. the similar area where PSA promoter expression was found. This specific migration was not observed with RWPE-1-shCon and PC-3 cells lines. These same fluorescence reporter experiments were performed in parallel in 48 hr and 72 hr post fertilization (hpf) dechorinated larvae. We observed similar results in the 72 hpf larvae as were found in 5 dpf larvae but not in the 48 hpf larvae. Taken together, these results suggest that RWPE-1-shDAB2IP and PZ-HPV7-shDAB2IP cells have the homing receptors necessary for migrating to the same area in gonads. Understanding these homing mechanisms may be relevant for controlling the abnormal migration in metastasis.

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 4377. doi:10.1158/1538-7445.AM2011-4377
Abstract 438: The CFP nude mouse as a host for color-coded imaging of the tumor microenvironment
Authors: Suetsugu Atsushi , Hassanein Mohamed K. , Reynoso Jose , Saji Shigetoyo , Moriwaki Hisataka , Bouvet Michael , Hoffman Robert M.
Published: June 2012

We have developed a color-coded model to study the tumor microenvironment using cancer cells expressing RFP or GFP implanted in nude mice expressing cyan fluorescent protein (CFP). When RFP or GFP HCT-116 were injected subcutaneously in CFP expressing nude mice, CFP expressing cancer-associated fibroblasts migrated to the tumor site. CFP-expressing tumor blood vessels were observed in the tumor. Other CFP host stromal cells were observed throughout the tumor mass. When RFP HCT-116 cells were transplanted in the spleen of CFP nude mice, they formed tumors in the liver. When RFP HCT-116 cancer cells were transplanted in the tail vein of CFP nude mice and they formed tumors in the lung. CFP-expressing host cells were observed in these tumors. When the RFP mouse mammary cancer cell line (RFP MMT) was injected subcutaneously in the CFP nude mouse, numerous CFP-expressing fibroblasts and CFP-expressing blood vessels was observed in the resulting tumor. A large inflammatory population of different CFP-expressing white blood cells surrounded the necrotic area of the tumor suggesting a relationship of these cells to tumor necrosis. GFP and RFP HCT-116 cancer cells were co-injected subcutaneously in CFP-nude mice and tumor growth was followed for 21 days. This three-color model enabled visualization of the tumor mass and its neovasculature in addition to a detailed visualization of other host reactions. GFP HCT-116 cancer cells were initially injected subcutaneously in RFP-nude mice and tumors formed within 14 days. At this point, the tumor mass which consisted of GFP cancer cells and RFP stroma derived from the RFP nude mouse, was harvested and transplanted to a CFP-nude mouse. CFP host cells invaded the growing transplanted tumor containing dual-color cancer cells and RFP stroma. Thus the CFP-nude mouse adds another color to the pallet to study the human tumor microenvironment allowing 4 types of cells to be simultaneously imaged in 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 438. doi:10.1158/1538-7445.AM2011-438
Abstract 4388: LipoplatinTM: A less neurotoxic formulation of Cisplatin
Authors: Canta Annalisa , Chiorazzi Alessia , Carozzi Valentina A. , Oggioni Norberto , Sala Barbara , Zucchetti Massimo , Cavaletti Guido A.
Published: June 2012

Purpose: Cisplatin is one of the most effective cytotoxic agent in the treatment of solid malignancies, but its use is limited by several side effects. Among them, peripheral neurotoxicity can be dose-limiting. A liposomal formulation of cisplatin, LipoplatinTM, was developed to reduce the systemic toxicity of cisplatin but preventing its efficacy. Aim of this study was to test in an animal model through a multimodal approach if chronic treatment with two different schedules of LipoplatinTM selected in the range of its anticancer effective dose is less neurotoxic than cisplatin administrations.

Methods: Female Wistar rats were treated intraperitoneally with cisplatin at the dose of 4mg/kg or with LipoplatinTM 12 and 24mg/kg once weekly for 4 times. General toxicity was assessed by daily observation, body weight change, hematological and blood chemistry analysis and histopathology of liver and kidney. The onset of the peripheral neurotoxicity was assessed using tail nerve conduction velocity (NCV), morphological and morphometrical analysis of dorsal root ganglia (DRG) and by morphological analysis of sciatic nerve.

Results: Cisplatin induced a statistically significant reduction in body weight, the development of renal failure and the impairment in NCV with pathological alterations in the DRG and sciatic nerve. By contrast no significant weight gain reduction was observed in animals treated with both doses of LipoplatinTM. Moreover the lowest dose induced a less severe damage to the peripheral nervous system with a moderate decrease of NCV and mild pathological alterations of DRG and sciatic nerve.

Conclusions: The results suggest that LipoplatinTM 12mg/kg is less neurotoxic than cisplatin 4mg/kg, thus opening the possibility to use this new formulation in future studies where its anticancer activity and the peripheral neurotoxicity will be assessed in parallel.

This study was supported by “Fondazione Banca del Monte di Lombardia”

Regulon supported this study exclusively by providing LipoplatinTM

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 4388. doi:10.1158/1538-7445.AM2011-4388
Abstract 4396: Evaluation of gene expression and transcriptional activation in patients treated with vorinostat
Authors: Kolesar Jill M. , Lau Elim , Seo Songwon , Eickhoff Jens , Kim KyungMan , Traynor Anne , Bailey Howard , Wilding George , Schelman William
Published: June 2012

Background: Vorinostat is a histone deacetylase (HDAC) inhibitor that is approved for treatment of cutaneous T-cell lymphoma and is being investigated in a number of solid tumors. Inhibition of HDAC by vorinostat leads to an accumulation of acetylated histones which induces apoptosis though a mechanism that is not completely characterized. This study was performed to assess the potential mechanisms responsible for induction of apoptosis following treatment with vorinostat. Methods: Sixty subjects with advanced malignancies received vorinostat orally days 1-14 combined with bortezomib IV on days 2, 4, 8, and 11 of a 21-day cycle. Peripheral blood mononuclear cells (PBMCs) were collected before and 2hr and 6hr after dosing on Days (D) 1 and 9. Paired tumor biopsies were obtained in ten patients on D0 and D9. Gene expression of downstream targets was evaluated by semi-quantitative RT-PCR in PBMCs, and the interaction between candidates genes and acetylated histone H3 were evaluated in biopsies by the chromatin precipitation assay. A nonparametric Wilcoxon signed rank test was used to examine changes from the pre-treatment value of 1 on D1 based on complete case analysis without multiplicity adjustment. Results: p21, Nur77 and HSP70 gene expression in PBMCs were all significantly induced two hours after vorinostat administration compared to baseline (Table 1). AKT, ERB1 and ERB2 expression were not statistically significantly altered in PBMCs. The expression of all targets increased in tumor biopsies by Day 9, with p21 2.37, Nur77, 1.33 and HSP70 2.35 times baseline expression levels. The chromatin precipitation assay demonstrated that Nur77, HSP70 and p21 interacted with acetylated histone H3, after nine days of treatment with vorinostat, in tissue biopsies. Conclusion: This data suggests that acetylated histones interact transcriptionally with p21, Nur77 and HSP77 to induce gene expression and are a potential mechanism by which vorinostat induces apoptosis.

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 4396. doi:10.1158/1538-7445.AM2011-4396
Abstract 4398: MEK inhibitors prevent rebound reactivation of ERK signaling by the RAF inhibitor PLX4032 and enhance its antitumor activity
Authors: Pratilas Christine A. , Joseph Eric W. , Tadi Madhavi , Gabay Maytal , Wong Wai , De Stanchina Elisa , Bollag Gideon , Rosen Neal
Published: June 2012

Activation of ERK signaling occurs in the majority of melanomas and tumors with BRAF mutation are especially sensitive to its inhibition with MEK or RAF inhibitors. The latter inhibit ERK signaling only in tumors with V600E mutant BRAF and activate the pathway in cells with WT BRAF. These data implied that RAF inhibitors would have a wider therapeutic index than MEK inhibitors with a greater therapeutic effect, but could also cause toxicity by activating the ERK pathway in normal tissue. These predictions were born out in clinical trials, in which the RAF inhibitor PLX4032 caused tumor regression in most patients with metastatic melanoma with mutant BRAF, but also caused squamous cell carcinoma of the skin in one third of patients. Unfortunately, these responses are rarely complete and the median time to relapse is approximately nine months.

We now find that prolonged treatment of BRAF mutant cells with PLX4032 is associated with a rebound of ERK phosphorylation from its nadir that is associated with an increase in the transcriptional output of the pathway and could therefore limit the therapeutic effects of the drug. In this new steady state, ERK phosphorylation and output are sensitive to MEK inhibitors but not readdition of RAF inhibitors. The rebound of ERK signaling is associated with upstream activation in the RAS pathway. We therefore determined the effects of combined RAF and MEK kinase inhibition in a panel of melanoma cells with mutant BRAF. Combined inhibition delayed pathway rebound and resulted in more prolonged suppression of ERK output, enhanced cell death, and tumor growth inhibition compared to treatment with the RAF inhibitor alone. These results suggest that combined RAF and MEK kinase inhibition may be a useful strategy to improve the extent and duration of responses to RAF inhibitors and minimize toxicity caused by ERK activation in normal tissue.

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 4398. doi:10.1158/1538-7445.AM2011-4398
Abstract 4399: In vitro and in vivo evaluations of correlation between the activation status of signaling pathways and the efficacy of anticancer compounds in a panel of JFCR39 human cancer cell lines
Authors: Dan Shingo , Okamura Mutsumi , Seki Mariko , Yamazaki Kanami , Mukai Yumiko , Yamori Takao
Published: June 2012

The phosphoinositide 3-kinase (PI3K) pathway and the Ras/mitogen-activated protein kinase (MAPK) pathway are frequently activated in cancer. Activation of these pathways contribute to cell survival, cell cycle progression and cell growth in the tumor, and are expected to influence the efficacy of antitumor compounds including conventional antitumor drugs, PI3K pathway inhibitors and Ras/MAPK pathway inhibitors. However, it is not well understood whether the efficacies of anticancer compounds can be predicted based on these aberrations and on the activation status of signaling pathway members. To clarify this issue, we first examined the mutation, expression and phosphorylation status of PI3K and Ras/MAPK pathway members in a panel of 39 pharmacologically well-characterized human cancer cell lines (JFCR39). Second, we evaluated the in vitro efficacy of various anticancer compounds including PI3K and Ras/MAPK pathway inhibitors and conventional anticancer drugs, combining these data to construct an integrated database of pathway activation status and drug efficacies (JFCR39-DB). In silico analysis of JFCR39-DB enabled us to evaluate correlations between the status of pathway members and the drug efficacies in vitro. For example, KRAS/BRAF mutation prominently correlated with the efficacy of a MEK inhibitor and the inefficacy of PI3K inhibitors, respectively, while phosphorylation levels of Akt correlated with the efficacy of PI3K inhibitors. Some of these correlations were confirmed in human tumor xenografts in vivo, consistent with their ability to serve as predictive biomarkers. Our findings show that JFCR39-DB is a useful tool to identify predictive biomarkers and to study molecular pharmacology of the PI3K and Ras/MAPK pathways in 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 4399. doi:10.1158/1538-7445.AM2011-4399
Abstract 4400: Blockade of Her2 binding to Hsp90 by emodin azide methyl anthraquinone derivative induces proteasomal degradation of Her2
Authors: Fu Liwu , Zheng Lisheng , Yan Yan-yan
Published: June 2012

Overexpression of HER2/neu, a transmembrane tyrosine kinase acting as a coreceptor for other EGFR family members, is well known to be associated with a poor prognosis in cancer. In the present study, we observed that emodin AMAD, a novel emodin azide methyl anthraquinone derivative, extracted from the nature giant knotweed rhizome of traditional Chinese herbs, potently decreased Her2/neu protein in dose- and time-dependent manners and also inhibited the downstream MAPK and PI3K-Akt signaling pathway. Intriguingly, reserve transcription-PCR and protein turn-over assay revealed that the decrease of Her2/neu was independent of mRNA level but primarily owing to its protein stability. Meanwhile, proteasome inhibitor MG132 but not lysosome inhibitor chloroquine could restore Her2/neu and polyubiquitination of Her2/neu was augmented during emodin AMAD treatment. Furthermore, immunofluorescence study with anti-Her2/neu antibody showed that emodin AMAD disturbed the subcellular distribution of Her2/neu, with decreased location in the plasma membrane. Importantly, coimmunoprecipitation with anti-Hsp90 antibody revealed that emodin AMAD markedly impaired the binding between Hsp90 and Her2/neu. In addition, combination of emodin AMAD treatment and SiRNA against Her2 synergistically inhibited proliferation and induced apoptosis. Taken together, these data suggest that blockade of Her2/neu binding to Hsp90 and following proteasomal degradation of Her2/neu was involved in emodin AMAD-induced apoptosis in Her2/neu-overexpressing cancer cells. Our results provide suggestions that emodin AMAD could be promising as a new targeting therapeutic strategy in the treatment of Her2/neu-overexpressing cancers.

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 4400. doi:10.1158/1538-7445.AM2011-4400
Abstract 4408: Molecular mechanisms underlying cancer pain: Application of cellular models
Authors: He Ying , Jhun Ellie , Wang Zaijie Jim
Published: June 2012

Pain is a major complaint in cancer patients. Little is known about the mechanisms leading to or maintaining cancer pain. This study is aimed to develop novel cellular models to study cancer pain. Isolated primary afferent sensory neurons were employed as a model system in order to produce cancer pain microenvironment in the presence of chemotherapeutic agents and cancer cells. Ca2+ imaging in sensory neurons showed increased [Ca2+]i within cancer pain microenvironment, suggesting a direct activation of sensory neurons. As a critical step in the initiation and transmission of pain cascades, release of pain neurotransmitters such as substance P and calcitonin-gene related peptide from primary afferent sensory neurons was studied and found to be significantly enhanced. As a result of sensory neuron activation, intracellular signaling transduction involving several major protein kinases was activated. For example, sub-apoptotic concentrations of paclitaxel (≤ 10 nM) potently elicit [Ca2+]i spikes, leading to PKA and PKC activation, and substance P release from primary afferent neurons. Moreover, AKAP150 was identified as a molecular mechanism synchronizing and transducing the activation of PKA to PKC. Our results reveal the presence of a specific cellular signaling pathway involving Ca2+/PKA/AKAP150/PKC(ε, βII, & Δ), independent of apoptosis, mediating pain neurotransmitter release and, ultimately, neuropathic pain induced by paclitaxel. Developing cellular models of cancer pain and identifying biomarkers/pathways may lead to novel diagnostic and therapeutic strategies for cancer pain.

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 4408. doi:10.1158/1538-7445.AM2011-4408
Abstract 4411: γH2AX as a marker of genomic instability predicts cisplatin sensitivity in triple negative breast cancer cells
Authors: Lehmann Brian D. , Bauer Josh A. , Sanders Melinda E. , Chakravarthy Bapsi A. , Pietenpol Jennifer A.
Published: June 2012

Triple negative breast cancers (TNBCs), that are hormone receptor negative (estrogen and progesterone) and lack HER2 amplification have limited treatment options. There is increasing evidence that TNBC is a heterogeneous disease and that patients with TNBC differentially respond to standard chemotherapies, which in many cases predicts for outcome. A portion of TNBC is considered genomically unstable as evidenced by array CGH analysis and the high frequency of BRCA1/2-mutations in TNBC patients. The identification of tumors displaying significant genomic instability may allow pre-selection of patients for select therapies (e.g. cisplatin, PARP inhibitors) that are more effective in the setting of deficient DNA damage response signaling. To determine if inherent genomic instability exists in TNBC, cell lines were analyzed for the phosphorylated histone variant 2AX (γ-H2AX) by immunohistochemistry and immunofluorescence as a marker of endogenous DNA damage. Tissue microarray blocks were created from 28 TNBC cell lines as well as appropriate controls to develop experimental conditions for γ-H2AX detection. TNBC cell lines significantly varied in the levels of baseline γ-H2AX foci, with BRCA1/2-mutant cell lines (HCC1937, HCC1599 and SUM149PT) having some of the highest levels. The presence of γ-H2AX foci in the absence of stress correlated with sensitivity (IC50) to cisplatin (R2 = 0.620), but not PARP inhibitors (R2 = 0.006). In addition to cell lines, we demonstrate that γ-H2AX staining can be detected in archived formalin-fixed, paraffin-embedded breast cancer tissue with approximately 25% of the tumors displaying high levels of nuclear γ-H2AX staining. Therefore endogenous levels of γ- H2AX may have potential use as a clinical biomarker to identify patients that will benefit from treatment with DNA-damaging agents.

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 4411. doi:10.1158/1538-7445.AM2011-4411
Abstract 4412: Prognostic significance of NF-κB in Middle Eastern diffuse large B cell lymphoma and efficacy of NF-κB inhibition as a viable therapeutic target
Authors: Bavi Prashant , Uddin Shahab , Bu Rong , Ahmed Maqbool , Abubaker Jehad , Al-Dayel Fouad , Balde Valorie , Naidu Padmanabhan , Al-Dossari Hassan , Qadri Zeeshan , Prabhakaran Sarita E. , Hussain Azhar R. , Al-Kuraya Khawla S.
Published: June 2012

NF-kB is frequently over expressed in variety of NHL and has been implicated in lymphomagenesis; however, its role in diffuse large B-cell lymphoma (DLBCL) as a prognostic biomarker has not been fully elucidated. Therefore, we investigated the role of NF-kB and its association with clinico-pathological features in a tissue microarray cohort of 230 DLBCL patient samples. We then elucidated the role of NF-kB inhibition on cell viability and apoptosis in-vitro using DLBCL cell lines. Using immunohistochemistry, NF-kB was detected in 25.6% (52/203) DLBCL tumors, was associated with activated B cell (ABC) phenotype (p=0.0054) and overexpression of anti apoptotic marker, XIAP (p=0.0013). DLBCL with nuclear expression of NF-kB showed a significantly poor overall survival as compared to those with no NF-kB expression (p=0.0236). In the multivariate analysis using Cox Proportional Hazard model for IPI and NF-kB expression, the relative risk was 2.97 for high NF-kB expression (95% CI 1.27-6.94; p=0.0113) and 7.55 for high IPI group (95% CI 3.34-18.35; p<0.0001). In-vitro, Bay11-7085 inhibited constitutively active NF-kB expression in a dose dependent manner. Inhibition of NF-kB also down-regulated expression of down-stream target gene products, such as Bcl-2, Bcl-Xl, XIAP and Survivin leading to apoptosis via the mitochondrial apoptotic pathway. NF-kB overexpression was found to be an independent prognostic marker for poor survival in DLBCL. Inhibition of NF-kB caused apoptosis via activation of the mitochondrial apoptotic pathway. Altogether, these results suggest that NF-kB may be a useful prognostic biomarker and a potential target for therapeutic intervention in DLBCL.

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 4412. doi:10.1158/1538-7445.AM2011-4412
Abstract 4413: A 5-gene model predicts clinical outcome in ER+/PR+, early stage breast cancers treated with adjuvant tamoxifen
Authors: Kerr Daniel Alan , Wittliff James L.
Published: June 2012

Purpose: Patients with primary breast carcinomas expressing of both estrogen (ERα) and progesterone receptors (PR) are more likely to respond to Tamoxifen therapy than those with ERα and PR negative cancers, especially in women with early stage lesions. However, a significant number of these patients exhibiting clinicopathologic features suggesting good response and prognosis will relapse within 10 years. Additional markers are needed to identify patients at risk for breast cancer recurrence after administrative hormone therapy.

Procedures: Ten candidate genes associated with estrogen signaling were selected from a group of 200 genes identified from microarray studies of laser capture microdissected breast carcinoma cells of ER positive breast cancers and combined with those for conventional biomarkers (ESR1, PGR, ERBB2). Carcinoma cell content and pathology of each biopsy was confirmed. Expression of this 13-gene subset was analyzed by RT-qPCR in de-identified frozen tissue specimens from early stage, ER+/PR+ breast cancers treated with adjuvant Tamoxifen. A multivariate model was created by Cox regression using a training set of tissue sections from 36 biopsy specimens, and then applied to an independent validation set of sections from 24 specimens.

Results: A 5-gene model was derived from the training set that exhibited significant correlations with both relapse-free and overall survival. Applying this model to Kaplan-Meier regression, patients were separated into low risk (100% relapse-free at 150 months) and high risk (60% relapse-free at 150 months) groups (P = 0.03). When this model was applied to the validation set, similar risk stratification was achieved for both relapse-free and overall survival (P = 0.01 and 0.04, respectively). No significant difference in clinical features (e.g., tumor grade, tumor size and nodal status) was observed between the high and low risk groups.

Conclusions: We developed a 5-gene model composed of PgR, BCL2, ERBB4 JM-a, RERG and CD34 that identified a subset of early stage, ER+/PR+ breast cancers patients treated with Tamoxifen that exhibited high recurrence rates, although their clinicopathologic features suggested good prognosis and response. Furthermore, absence of association of the 5-gene model with tumor grade suggests the gene expression profile provides clinically relevant predictive information independent of proliferation. Supported in part by grants from the Phi Beta Psi Sorority Charity Trust and a CTSP award from the Commonwealth of Kentucky. DAK was a recipient of a Graduate Fellowship from the Integrated Programs in Biomedical Sciences, University of Louisville, and the Spatola Graduate Fellowship from IMD3.

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 4413. doi:10.1158/1538-7445.AM2011-4413
Abstract 4426: Preclinical development of a rare tumor model: Establishment and characterization of a patient-derived collecting duct carcinoma
Authors: Thangasamy Amalraj , Nieves Francis , Papadopoulos Kyriakos , Patnaik Amita , Tolcher Anthony , Wick Michael J.
Published: June 2012

Collecting duct carcinoma (CDC) is a rare type of renal tumor accounting for approximately 2% of all renal cell carcinomas (RCC). Unlike common RCC that arises from the convoluted tubules of the renal cortex, this aggressive tumor is derived from the renal medulla, possibly from the distal collecting duct of Bellini. Clinically this aggressive tumor is shown to have a poor response to therapy and the majority of patients when diagnosed are in the metastatic phase. While several agents have been recently approved for standard RCC, lack of useful preclinical models of CDC have limited drug screening for potential therapies.

To this end we have established a patient-derived model of CDC and characterized mutational status and target expression. In addition, we have evaluated in vivo drug sensitivity to agents approved for standard RCC including sorafenib and sunitinib as well as the chemotherapies irinotecan and gemcitabine and targeted therapy temsirolimus. For model establishment a core biopsy was collected and engrafted into an immune-deficient mouse; once take was confirmed tumor tissue was passaged until model stabilization at which point tissue was taken for characterization and in vivo drug sensitivity evaluated. For model characterization, mutation status and expression of target molecules in proliferation pathways were examined by PCR and immunohistochemistry. In the drug sensitivity study, targeted RCC therapies and gemcitabine reported modest tumor growth inhibition while irinotecan was active with significant inhibitory effects. Some activity was reported with the mTOR inhibitor temsirolimus but its effect was not found statistically significant.

Overall we have established and characterized a rare patient-derived tumor model of RCC and demonstrated its use as a tool for screening potentially useful agents for patients with collecting duct carcinoma.

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 4426. doi:10.1158/1538-7445.AM2011-4426
Abstract 4429: Toxicology and drug delivery by novel cucurbit[n]uril-type nanocontainers
Authors: Hettiarachchi Gaya , Ma Da , Nguyen Duc , Isaacs Lyle , Briken Volker
Published: June 2012

Many drug delivery systems are based on the ability of certain macrocyclic compounds – such as cyclodextrins – to act as molecular containers for pharmaceutical agents in water. Cucurbit[n]urils (CB[n]) are a class of molecular containers that bind to a variety of cationic and neutral species with high affinity and therefore show great promise as a drug delivery system. We hypothesized that these nanocontainers can be used to increase solubility of hydrophobic small chemical compound drugs. In this study we investigated the toxicology, uptake, and bioactivity of two cucurbit[n]urils CB[n]-type containers (named Motor1 and Motor2). Both containers induced no toxicity at concentrations of up to 1 mM in human cell lines originating from kidney, liver or blood tissue using assays for metabolic activity and cytotoxicity. Furthermore, the Motor1 container was tolerated in mice without any toxicity after intravenous dosing of up to 1.5g/kg bodyweight. Interestingly, Motor1 was able to bind the cancer drug paclitaxel and increase its solubility in water by a factor of 2000. Motor2 demonstrated an increase of water solubility of camptothecin by 500fold. Finally, bioactivity assays showed that the increase in solubility by paclitaxel via Motor1 led to a more efficient killing of the ovarian cancer cell line SKOV-3. In conclusion, our study reveals very low toxicity of two novel members of the cucurbit[n]uril family of nanocontainers. It demonstrates the increase in solubility of two important cancer drugs by the containers which led to increased killing of cancer cells in vitro. These results provide initial proof-of-concept towards the use of CB[n] molecular containers as an advanced drug delivery system.

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 4429. doi:10.1158/1538-7445.AM2011-4429