bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 700: Reduced CYLD expression is an independent prognostic factor in breast cancer: A possible link with RANKL-RANK signaling
Authors: Hayashi Mitsuhiro , Shinriki Satoru , Nakamura Takuya , Ibusuki Mutsuko , Sueyoshi Takanao , Ota Tomoko , Yamamoto Yutaka , Iwase Hirotaka , Ando Yukio
Published: August 2012

Background: Deubiquitinase CYLD plays an important role in tumorigenesis and immune response. RANKL-RANK system is required for osteoclast development and is also involved in bone metastasis in various malignancies while it has been also implicated in tumorigenesis, metastasis to distant organs other than bone in breast cancer through unknown mechanisms. Importantly, a recent study has reported that CYLD negatively regulated RANKL-RANK signaling in osteoclastogenesis. However, not only the role of CYLD but also its involvement in RANKL-RANK signaling in breast cancer is largely unknown. The purpose of this study was to elucidate clinical and biological significance of CYLD as well as its association with RANKL-RANK signaling in breast cancer. Materials and Methods: We assessed CYLD mRNA expression in 305 primary invasive breast cancer tissues including 26 matched-pair of tumoral and adjacent non-tumoral tissues, and 9 breast cancer cell lines as well as a nonmalignant breast epithelial cell line, HMEC by quantitative real-time RT-PCR. In addition, effect of CYLD knockdown by using siRNA on cell proliferation, migratory activity and the biological activity of RANKL in MDA-MB-231 cells. Results: Expression levels of CYLD mRNA were lower in tumoral lesion than the matched non-tumoral lesion in all of 26 cases. Our statistical analysis revealed that lower CYLD mRNA expression was significantly associated with reduced disease free survival rate (rog-rank, p = 0.025), irrespectively of breast cancer subtype. Multivariate analyses for disease free survival confirmed that low CYLD mRNA expression (Hazard ratio: HR 2.23, 95% CI 1.09 - 4.36, p = 0.029) in addition to estrogen receptor status (HR 0.15, 95% CI 0.05 - 0.44, p = 0.0003) and lymph node metastasis (HR 2.21, 95% CI 1.10 - 4.62, p = 0.026) were significant factors. Consistent with our clinical data, CYLD gene expression was reduced in all the breast cancer cell lines compared with HMEC cells. Repression of CYLD gene expression led to increased cell number in MDA-MB-231 cells. Interestingly, combination of CYLD knockdown and RANKL stimulation promoted cell migration while no change was observed in the setting of each alone. Conclusion: Downregulation of CYLD was common and an independent poor prognostic factor in invasive breast cancer. CYLD repression may promote breast cancer development and/ or progression in coordination with RANKL-RANK signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 700. doi:1538-7445.AM2012-700
Abstract 706: Ribonucleotide reductase small subunit M2 is a potential prognostic biomarker in human epidermal growth factor receptor 2- positive and triple negative breast cancers
Authors: Zhang Hang , Liu Xiyong , Deng Xutao , Liu Zheng , Warden Charles , Huang Yasheng , Bai Rui , Chen Huarong , Loera Sofia , Peng Jiaping , Zhou Lun , Ge Weiting , Hu Hanguang , Zhang Suzhan , Chu Peiguo , Zheng Shu , Yen Yun
Published: August 2012

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer and triple negative breast cancer (TNBC) are two subtypes with poor outcome of all breast carcinomas. However, among all the patients in these two subtypes some still yielded relatively better prognosis. Ribonucleotide reductase (RR) small subunits M2 was associated with cancer cell invasiveness and metastasis, which prognoses poor survival in many cancers. Here we investigated whether RRM2 could serve as a prognostic biomarker for breast cancers, especially HER2- positive and TNBC subgroups. One hundred seventy five assessable breast cancers (40 cases were HER2-positive or TNBC) were collected from affiliated hospital of Zhejiang University (ZJU set); and six published microarray data sets (total 1154 cases, 63 cases were identified as HER2- positive or TNBC) with pathoclinical and follow- up information were employed for validation. In the ZJU set, the protein level of RRM2 was determined by IHC. It was indicated that RRM2 was positively correlated with cell proliferative marker Ki-67 (trends P=0.018) and stem/progenitor cell marker CD44+/CD24-/low (P=0.044). Multivariate COX model revealed that RRM2 was an independent prognostic biomarker for both OS (Hazard Ratio, HR=2.79, 95%Cl 1.21-6.75) and PFS (Hazard Ratio, HR=1.82, 95%Cl 1.02-3.26) for all the breast cancers. Moreover, in HER2-positive or TNBC breast cancers, RRM2-high was significantly associated with poor survival (P=0.025). Consequently, none of the patients with RRM2-low died of breast cancer in HER2-positive or TNBC subgroups. Furthermore, above findings were validated in the published data sets. The mRNA level of RRM2 evaluated significantly in highly-invasive subtypes including Luminal B, HER2-positive and TNBC in comparison with Luminal A and unclassified subgroups (P<0.05). Overexpression of RRM2 was positively associated with poor differentiation (P<0.05), advanced AJCC stage (P<0.05) as well as poor survival (P<0.05) in a dose-dependent manner. It was also revealed that high expression of RRM2 prognosed poor survival (HR=5.56, 95% CI 1.14-99.9) in HER2-positive breast cancers or TNBC. Moreover, the RRM2-high (protein or mRNA levels) was associated with better response to chemotherapy comparing to RRM2-low. Taken together, the above findings suggested that RRM2 was a potential biomarker for poor survival in breast cancer, especially in HER2- positive breast cancer and TNBC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 706. doi:1538-7445.AM2012-706
Abstract 708: Clinical significance of insulin-like growth factor 1 receptor (IGF1R) expression in pancreatic cancer
Authors: Hirakawa Toshiki , Yashiro Masakazu , Morisaki Tamami , Aomatsu Naoki , Fukuoka Tatsunari , Yoshii Mami , Hasegawa Tsuyoshi , Matsuoka Junko , Nagahara Hisashi , Kimura Kenjiro , Noda Eiji , Amano Ryosuke , Kubo Naoshi , Tanaka Hiroaki , Muguruma Kazuya , Yamada Nobuya , Maeda Kiyoshi , Nakata Bunzo , Ohira Masaichi , Hirakawa Kosei
Published: August 2012

Introduction: Insulin like growth factor 1 receptor (IGF1R) reported to be overexpressed in some types of human carcinomas, including lung cancer, and breast cancer. However no report of the significance of IGF1R expression was available in pancreatic cancer. Most patients with pancreatic cancer die within 2 years at diagnosis even after curative resection. The objective of this study was to evaluate the significance of IGF1R expression in human pancreatic cancer. Material and Methods: A total 122 patients with pancreatic cancer was studied. Paraffin embedded species of pancreatic cancers were stained with antibodies against IGF1R. IGF1R expression was evaluated by intensity of staining. Semi-quantitative scores of zero (no staining), 1+ (weak staining), 2+ (moderate staining), or 3+ (strong staining) were assigned to each sample based on the intensity of staining. Scores of 2+ or 3+ were defined as IGF1R-positive staining. The association between IGF1R expression and clinicopathologic variables was examined. Results: IGF1R expression was positive in 50 (40.1%) of 122 cases. Kaplan-Meier analysis demonstrated the prognosis of IGF1R-positive patients was significantly (p=0.0076) poorer than that of IGF1R-negative, and median survival time of patients with IGF1R-positive was 37.3 months, while that of patients with IGF1R-negative samples was 60.8 months. There were no associations between IGF1R overexpression and clinicopathological factors, including tumor location, tumor size, tumor differentiation, and T/N categories according to the International Union against Cancer. Multivariate analysis showed IGF1R expression and lymph node metastasis were independent predictors of worse prognosis in pancreatic cancer. Conclusion: The expression of IGF1R might be a novel predictive prognostic marker for patients with pancreatic cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 708. doi:1538-7445.AM2012-708
Abstract 710: Genetic identification of Annexin-A8 as a therapeutic target and prognostic marker for pancreatic cancer
Authors: Pimiento Jose M. , Chen Dung-Tsa , Centeno Barbara , Husein Kazim , Wang Chen , Zhang Anying , Malafa Mokenge P.
Published: August 2012

Introduction: We previously have identified histologic grade as an important prognostic factor for outcomes in early stage pancreatic cancer following surgical resection. In this study we investigated genes associated with histologic differentiation in early stage pancreatic cancer and their biologic relevance. Methods: We studied the gene expression profile of 61 resected primary pancreatic cancers through analysis of a custom Affymetrix microarray. Significance analysis of microarrays was used to select genes associated with histologic grade. Following identification of these genes we focused on Annexin A8 (A-A8) for further mechanistic studies. We analyzed the relationship of protein expression, tumor grade and outcomes using immunohistochemistry (IHC) in a tissue microarray (TMA) of 91 resected pancreatic cancer patients. Mechanistic studies of A-Aa8 included gene silencing using SiRNA and measurement of the cellular effects by migration, proliferation and colony formation assays. Statistical analysis was performed with Fisher's exact test, T-test and ANOVA as indicated and Cox modeling was used for survival analysis. Results: We identified 34 genes that were downregulated, and 15 genes that were upregulated as tumor grade progressed from well to moderate to poorly differentiated. Then we focused on A-A8 induction in this data set, with a 5.9 fold increased A-A8 expression from low to high grade tumors (r=0.31;p=0.019), the immunohistochemical expression of A-A8 was correlated with tumor grade in a human pancreatic tumor tissue microarray (r=0.26;p=0.014); finally high expression of A-A8 is associated with a significant decrease in 5 year survival following resection of stage I and II human pancreatic cancer by Cox model (p=0.049). Western blotting confirmed increased expression of A-A8 in human pancreatic cancer cell lines. Knockdown of A-A8 in human pancreatic cancer BXPC-3 cells with SiRNA resulted in significant decrease in cell viability (p<0.001), cell migration (2.5 vs. 0.9mm at 96h;p=0.048), and colony formation (p=0.007). Conclusions: Studying the expression profiles of primary pancreatic cancer analyzed on Affymetrix microarrays, we identified A-A8 as a gene associated with pancreatic cancer differentiation. Downregulation of A-A8 by RNA interference in pancreatic cancer cells results in growth and migration inhibition. Finally we show that high A-A8 expression is associated with poor disease outcome in pancreatic cancer patients. These results support further investigation of Annexin A8 as a potential therapeutic target and prognostic marker for human pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 710. doi:1538-7445.AM2012-710
Abstract 713: GLRX3, a secretory biomarker of pancreatic cancer based on pancreatic cancer stem cell characteristics
Authors: Kim Sun A , Park Soo Bin , Song Si Young
Published: August 2012

A. BACKGROUND/AIMS Pancreatic cancer is one of the most lethal diseases, which is difficult to diagnose and resistant to conventional treatment such as chemotherapy and radiotherapy. Cancer stem cells are involved in carcinogenesis, cancer progression and recurrence. We tried to find secretory biomarkers associated with pancreatic cancer stem cells using proteomic analysis. B. METHODS Pancreatic cancer stem like cells were enriched using sphere culture method. Proteomic analysis was done with secreted protein in culture medium of sphere and adherent cells. Identified proteins were confirmed with Western blot and immunohistochemical staining. ELISA was done to detect blood levels of validated proteins in pancreatic cancer patients. shRNA for GLRX3 was used to study the function of GLRX3 in pancreatic cancer. C. RESULTS Proteomic analysis showed that total of 55 protein spots from sphere cells were increased compared to adherent cells. Among them, 41 spots were identified using MALDI-TOF. Proteins known to be associated with cancer stem cells such as HSP90AB1, ALDH, and vimentin were expressed in sphere cells. The overexpression of 5 proteins including GLRX3 was confirmed by western blot in sphere cells and patient serum. Immunohistochemical staining in TMA of human pancreatic cancer tissue revealed that GLRX3 was detected in 15 (57.7%) out of 25 pancreatic cancer tissues regardless of cancer stages. To examine GLRX3 involvement in pancreatic carcinogenesis, we used shRNA to generate GLRX3-knockdown cells. Compared to the mock, knockdown of GLRX3 in human pancreatic cancer cell lines decreased in vitro proliferation, clonogenecity, and sphere formation. GLRX3 knockdown reverses epithelial-mesenchymal transition in pancreatic cancer cells. ELISA showed patients with unresectable pancreatic cancer and high blood GLRX3 levels had poor survival compared to those with low blood GLRX3 levels (155 days vs 463 days, p-value <0.000). D. CONCLUSION This study shows that secretory protein GLRX3 may be a useful prognostic marker in pancreatic cancer. More researches are needed to find their roles in cancer stem cells and clinical implication.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 713. doi:1538-7445.AM2012-713
Abstract 717: Aldo-keto reductase family 1B10 (AKR1B10): Novel biomarker and molecular target of hepatocellular carcinoma
Authors: Bai Han , Zhang Wanying , Li Haonan , Matkowskyj Kristina A. , Yang Allison L. , Liao Jie , Yang Guang-Yu
Published: August 2012

Aldo -keto reductase family 1B10 (AKR1B10) is a member of aldo-keto reducase (AKR) superfamily with biologic functions involved in osmolytic regulation, carbonyl detoxification, and carcinogenesis. Overexpression of AKR1B10 is identified in tumors of liver, lung, cervix and pancreas. However, the functional role of AKR1B10 in cancer remains unclear. In the present studies, we determined the expression and function of AKR1B10 in human hepatocellular carcinoma (HCC) using ex vivo HCC tissues and HCC cell lines. Thirty nine of HCC surgical resected specimens have been analyzed for the expression of AKR1B10 using immunohistochemistry method and revealed that 92.3% (36/39) of HCC expressed AKR1B10, including 100% (10/10) well differentiated, 95.2% (20/21) moderate differentiated, and 75% (6/8) poor differentiated HCC. No expression was observed in the adjacent morphologically normal liver. Expression of AKR1B10 in HCC confined to the cytoplasm. In order to investigate the oncogenic role of AKR1B10 in HCC, silence or inhibition of AKR1B10 in HCC cells (Huh 7) was approached using lentivirus mediated shRNA method or AKR1B10 inhibitor epalrestat. The results showed that the expression of AKR1B10 protein was significantly decreased in the AKR1B10 silenced cell lines with three different shRNA sequences using western blot approach. Knockdown AKR1B10 resulted in a significant inhibition of Huh 7 cell proliferation/tumorigenesis by colony formation assay and showed the average clone number was 174±25 of pGIPZ vector control Huh7 cell, and 86±32 of the AKR1B10 shRNA silencing cells (p<0.05). The average clone size was also significantly decreased in AKR1B10 shRNA silencing cells. A slightly increased cell apoptosis was found in AKR1B10 silenced cells as detected with both caspase-3 immunohistochemistry (IHC) and Annexin V flow cytometry. Furthermore, AKR1B10 silenced cells or pGIPZ vector control Huh7 cells pretreated with AKR1B10 inhibitor epalrestat significantly increased sensitivity to doxorubicin and 4-hydroxy Hexenal-induced cell death as measured with Annexin V flow cytometry. Reduction of GTP-KRAS activity and its downstream MAPK signals were observed in AKR1B10 silencing cells as measured by western bolt approach. Our results indicated that AKR1B10 is involved in the process of cell proliferation, apoptosis, and Kras activation, and further imply that AKR1B10 is a novel biomarker and crucial molecular target of HCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 717. doi:1538-7445.AM2012-717
Abstract 74: The role of epithelial splicing regulatory protein 1 in ovarian cancer
Authors: Yuan Chengfu , He Xiaolong
Published: August 2012

Epithelial splicing regulatory protein 1 (ESRP1) is a recently identified cell type-specific splicing factor which has been shown to control an alternative splicing network associated with the epithelial-mesenchymal transition (EMT). Whether ESRP1 play any roles in the development and progression of epithelial ovarian cancer is unknown. To answer this question, we first examined its expression by RT-PCR in a panel of cultured cells including normal ovarian surface epithelial cells (HOSE), immortalized OSE (IOSE398 and IOSE120T) as well as ovarian cancer cell lines A2780, OVCA3, OVCAR5, OVCAR8 and SKOV3. We found that ESRP1was expressed at low levels in HOSE, IOSEs and A2780 cells, at intermediate levels in OVCAR8 and SKOV3 cells and at high levels in OVCAR3 and OVCAR5 cells. Examination of ESRP1 target gene FGFR2 showed that cells with low to intermediate levels of ESRP1 exclusively expressed mesenchymal form of FGFR2 (FGFR2IIIc) while cells with high levels of ESRP1 exclusively expressed epithelial form of FGFR2 (FGFR2IIIb). These results suggest two notions: 1) the switch of FGFR2 splicing occurs in an all-or-none format dependent on the threshold of ESRP1 expression levels; 2) normal ovarian surface epithelial cells may have mesenchymal properties. We also examined the expression of ESRP1 in seven pairs of matched ovarian tumor and adjacent normal tissues and found that ovarian tumors expressed higher levels of ESRP1 than normal tissues in all pairs. In the attempt to clone the entire coding sequence of ESRP1 from SKOV3 cells, we have identified 11 ESRP1 splice variants (SVs). Ectopic expression of four ESRP1 SVs in 293T and A2780 cells, which both have very low levels of endogenous ESRP1, triggered profound apoptosis. The two SVs with exons 14 and 15 skipped appeared more cytotoxic than full-length ESRP1. We are currently investigating the effects of knockdown of ESRP1 on the transformation properties of ovarian cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 74. doi:1538-7445.AM2012-74
Abstract 75: Identification and characterization of novel MELK (maternal embryonic leucine zipper kinase) substrates in breast cancer cells
Authors: Chung Suyoun , Nakamura Yusuke
Published: August 2012

Breast cancer is the most common malignancy among women worldwide. Treatment for breast cancer acting on molecular targets in critical signaling pathways in cancer cells have successfully reduced the motility rate in a subset of breast cancer patients, but a significant portion of patients cannot expect to have benefits from these treatments. Therefore, development of new therapeutics for those patients urgently required. Toward the goal of cancer-specific drug development, we previously identified MELK (maternal embryonic leucine zipper kinase) as a target for development of novel breast cancer therapy through genome-wide expression profile analysis. MELK was over-expressed in the great majority of breast cancer cells, particularly in TN breast cancer cells, and knockdown of MELK significantly suppressed the growth of breast cancer cells. Concordantly, the cells, which were transiently induced MELK, promoted its proliferation. Furthermore, cells in which over-expression of MELK were likely to increase the proportion of breast cancer-initiating stem cells more than those transfected with mock vector or kinase-dead MELK mutant plasmid. Although several substrates of MELK were reported, we are still not fully understood how MELK contributes to breast cancer development or progression. To elucidate the MELK signaling pathway in breast cancer cells, we examined 2D-PAGE and mass spectrometric analysis. Finally, we successfully identified two novel substrates of MELK. We confirmed the phosphorylation of these substrates by MELK via in vitro kinase assay and identified phosphorylation sites on each substrate by mass spectrometry. These results provide new information for better understanding of the biological role of MELK.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 75. doi:1538-7445.AM2012-75
Abstract 757: Development and validation of an HPLC-UV method for lapatinib quantification in human plasma
Authors: Escudero Vanesa , Valenzuela Belén , Rebollo Joseba , Sureda Manuel , Brugarolas Antonio
Published: August 2012

Background and objective: Lapatinib is a 4-anilinoquinazoline that can reversible and selectively inhibit both human epidermal growth factor receptor (EGFR, HER1) and human epidermal growth factor receptor type 2 (HER2) tyrosine kinases. As others tyrosine kinase inhibitors (TKIs), lapatinib shows a large interindividual variability in its pharmacokinetics (PK). So, the variability in drug exposure to TKIs may contribute to the variation in anti-cancer PD effect. Causes for this PK variability are manifold during the different processes of ADME. Up to date, only mass spectrometry detection is currently available to determine lapatinib in human plasma. The purpose of this study was to develop a simple and sensitive high-performance liquid chromatographic method with UV-Visible detection for quantification of lapatinib concentrations in human plasma to allow therapeutic drug monitoring (TDM) of lapatinib in cancer patients. Methods: After a liquid-liquid extraction with acetonitrile, lapatinib and sorafenib (internal standard, IS) are separated on Ultrabase C18 column using a mobile phase consisting of a mixture of 0.02 M ammonium acetate and acetonitrile in a proportion 47:53 pumped at a constant flow rate of 1.2 mL/min. The column was maintained at 25°C and the eluent was monitored at a wavelength of 260 nm. Results: The calibration curve was linear in the range 200-10000 ng/mL. The limit of quantification was determined to be 200 ng/mL. Lapatinib and IS retention times were 3.2 and 10.6 min, respectively. Inter- and intra-day coefficients of variation were less than 7%. The mean extraction recovery from plasma was higher than 86%. Conclusion: The simple, rapid and sensitive HPLC-UV method developed and validated for the measurement of lapatinib in human plasma using sorafenib as IS can be applied easily in routine clinical practice for the TDM of lapatinib.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 757. doi:1538-7445.AM2012-757
Abstract 77: Study of the effect of MAPRE2 on human lung adenocarcinoma cell migration and invasion
Authors: Lai Yi-Hua , Chen Ching-Hsien , Tsai Meng-Feng , Chen Huei-Wen , Su Kang-Yi , Yuan Ang , Chen Jeremy J.W.
Published: August 2012

Lung cancer is the most malignant disease which makes lots of people dead worldwide. More and more evidences showed that cancers might arise from chromosome alteration, including amplification or deletion. Our previous study integrating microarray-based comparative genomic hybridization and affymetrix gene expression profiles identified a potential candidate gene, MAPRE2, in a lung cancer cell line model with different invasion capability. MAPRE2 (Microtubule-associated protein RP/EB family member 2) is usually located on microtubule and interactes with tumor suppress gene APC (adenomatous polyposis coli). MAPRE2 might be involved in microtubule polymerization, cell migration and tumorigenesis of colorectal cancers, but its function is unclear. The purpose of this study is to investigate the effects of MAPRE2 on cancer cell function. The results of real-time PCR and western blotting showed that DNA copy number, RNA and protein level of MAPRE2 were higher in low invasive lung cancer cells than in highly invasive cells. Immunofluorescence assay indicated that the distribution of MAPRE2 protein was predominant in cytoplasm. Furthermore, overexpression of MAPRE2 could inhibit cancer cell proliferation, anchorage- dependent and -independent growth, cell motility, invasion ability in vitro and tumor growth and metastasis in vivo. On the contrary, silencing MAPRE2 enhanced lung cancer cell proliferation and invasion ability. Consider the whole map of MAPRE2-regulated signalling, transcriptomic analysis was performed and the results showed that MAPRE2 could affect 1039 genes (ANOVA, FDR< 0.05) which are dominantly involved in cell cycle and adhesion-related biological signalling, such as MAPK, focal adhesion and tight junction pathways. Our results suggested that MAPRE2 might play a significant role in MAPRE2-mediated pathways to suppress tumorigenesis and metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 77. doi:1538-7445.AM2012-77
Abstract 776: Sensitization of glioblastoma cells to temozolomide induced antitumor effect by PLGA-aspirin microsphere through modulation of β-catenin transactivation
Authors: Shi Zhendong , Qian Xiaomin , Han Lei , Zhang Kailiang , Zhu Shanjun , Zhu Jialin , Lan Fengming , Zhang Junxia , Zhang Chunzhi , Pu Peiyu , Yuan Xubo , Kang Chunsheng
Published: August 2012

Malignant gliomas are the most prevalent and deadliest brain neoplasms. Although temozolomide (TMZ) was currently used for treating glioblastoma patients, the recurrence was commonly existed due to the acquired therapeutic resistance. Thus the combination chemotherapy with TMZ is considered a promising therapeutic strategy in overcoming therapeutic resistance and improving treatment efficacy. In this study, we performed PLGA microspheres of aspirin and TMZ by spray drying technique and detected their cytotoxicity to glioblastoma cells. In vitro assay, PLGA-aspirin (PLGA-A) microsphere treatment revealed a slight inhibition of proliferation, invasion, as well as slightly induced apoptosis of A172 and U87 cells through inhibition of β-catenin transactivation in comparison with PLGA microsphere and Control group. In addition, the limited antitumor effect was also demonstrated in vivo. However, PLGA-aspirin-temozolomide (PLGA-A-T) microsphere treatment group displayed enhancing antitumor efficacy compared with PLGA-temozolomide (PLGA-T) microsphere group. IC50 values were dramatically decreased in cells treated with PLGA-A-T microsphere, to a greater extent than those treated with PLGA-A microsphere. Meanwhile, the PLGA-A-T microsphere significantly enhanced apoptosis in both A172 cells and U87 cells, and cell proliferation and invasiveness were obviously weakened. In response to the inhibition of β-catenin signaling, β-catenin/TCF4 transcriptional activity and STAT3 luciferase activity was strongly inhibited, as well as a greater decrease of mRNA and protein expression levels of β-catenin, TCF4, pAKT and pSTAT3.Similar results were also observed in vivo, intratumoral injection of PLGA-A-T microsphere significantly downregulated expression of β-catenin, TCF4, pAKT, pSTAT3 and PCNA, and also delayed tumor growth in nude mice harboring subcutaneous U87 xenografts. These results indicated that the synergistic cytotoxic effect of aspirin and temozolomide was achieved by aspirin- temozolomide -loaded PLGA nanoparticles through inhibition of β-catenin transactivation, offering the potential for improved treatment of glioblastomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 776. doi:1538-7445.AM2012-776
Abstract 778: HER2 as therapeutic target for overcoming ATP-binding cassette transporter-mediated chemoresistance in small cell lung cancer
Authors: Minami Toshiyuki , Kijima Takashi , Otani Yasushi , Kohmo Satoshi , Takahashi Ryo , Nagatomo Izumi , Hirata Haruhiko , Suzuki Mayumi , Inoue Koji , Takeda Yoshito , Kida Hiroshi , Tachibana Isao , Kumanogoh Atsushi
Published: August 2012

Small Cell Lung Cancer (SCLC) easily acquires multidrug resistance after successful initial therapy. Overexpression of ATP-binding cassette (ABC) transporters is important for the multidrug resistance. Among them, ABCB1 and ABCG2 are known to be upregulated in chemoresistant SCLC. We found that human epidermal growth factor receptor 2 (HER2) expression is also upregulated in chemoresistant SBC-3/ETP, SBC-3/SN-38 and SBC-3/CDDP cells, compared to chemosensitive SBC-3 cells. Lapatinib, a tyrosine kinase inhibitor of HER2, could not suppress proliferation of these HER2-positive SCLC cells, but successfully restored chemosensitivity to etoposide and SN-38 in SBC-3/ETP and SBC-3/SN-38 cells, respectively. The reversal effect of lapatinib was thought to be caused by inhibition of drug efflux-pump functions of ABC transporters, and was producible with a clinically applicable concentration. Moreover, knocking down of HER2 by a small interfering RNA weakened the effect of lapatinib on ABCB1, indicating the involvement of HER2 in the inhibitory mechanisms. Notably, we demonstrated that caveolin-1 and Src play key roles in modulating ABCB1 function via HER2 inactivation. In SBC-3/ETP cells, dephosphorylation of HER2 by lapatinib activates Src and successively leads to increase caveolin-1 phosphorylation. Through this process, caveolin-1 dissociates from HER2 and strengthens association with ABCB1, and finally impairs the pump functions. Furthermore, we demonstrated that treatment by lapatinib in combination with etoposide or irinotecan significantly suppresses the growth of subcutaneous SBC-3/ETP and SBC-3/SN-38 tumors in mice, respectively. Collectively, these results indicate that combination therapy with lapatinib and cytotoxic agents could conquer ABC transporter-mediated chemoresistance in SCLC, especially in HER2-positive cases.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 778. doi:1538-7445.AM2012-778
Abstract 780: An EGFR inhibitor enhances the efficacy of SN38, an active metabolite of irinotecan, in SN38-refractory gastric carcinoma cells
Authors: Yashiro Masakazu , Qiu Hong , Hasegawa Tsuyoshi , Zhang Xiaotian , Morisaki Tamami , Fukuoka Tatsuynari , Aomatsu Naoki , Hirakawa Toshiki , Sakurai Katsunobu , Kubo Naoshi , Tanaka Hiroaki , Yamada Nobuya , Maeda Kiyoshi , Sawada Tetsuji , Ohira Masaichi , Hirakawa Kosei
Published: August 2012

Background: Acquired drug resistance to irinotecan is one of the significant obstacles in the treatment of advanced gastric cancer. This study was performed to clarify the effect of epidermal growth factor receptor (EGFR) inhibitors in combination with SN38, an active metabolite of irinotecan, on the proliferation of irinotecan-refractory gastric cancer. Methods: Two irinotecan-resistant gastric cancer cell lines, OCUM-2M/SN38 and OCUM-8/SN38, were respectively established by stepwise exposure to SN38 from the parent gastric cancer cell lines OCUM-2M and OCUM-8. The combination effects of two EGFR inhibitors, gefitinib and lapatinib, with SN38 on proliferation, apoptosis, and cell-cycle on gastric cancer cells were examined. Results: Gefitinib or lapatinib showed synergistic anti-tumor effects against OCUM-2M/SN38 and OCUM-8/SN38 cells when used in combination with SN38, but not against OCUM-2M or OCUM-8 cells. SN38 increased the expression of EGFR and HER2 in OCUM-2M/SN38 and OCUM-8/SN38 cells. The combination of an EGFR inhibitor and SN38 significantly increased the levels of apoptosis-related molecules, caspase-6, p53, and DAPK-2, and resulted in the induction of apoptosis of irinotecan-resistant cells. The EGFR inhibitors increased the S-phase and decreased the UGT1A1 and ABCG expression in irinotecan-resistant cells. The SN38 plus Lapatinib group more effectively suppressed in vivo tumor growth by OCUM-2M/SN38 cells than either alone group.Conclusion: The combination treatment with an EGFR inhibitor and irinotecan might produce synergistic anti-tumor effects for irinotecan-refractory gastric cancer cells. The regulation of SN38 metabolism-related genes and cell cycle by EGFR inhibitors might be responsible for the synergism.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 780. doi:1538-7445.AM2012-780
Abstract 781: The effect of vorinostat on the development of resistance to doxorubicin in neuroblastoma
Authors: Lautz Timothy B. , Jie Chunfa , Clark Sandra , Naiditch Jessica A , Jafari Nadereh , Qiu Yi-Yong , Zheng Xin , Madonna Mary Beth , Chu Fei
Published: August 2012

Histone deacetylase (HDAC) inhibitors, especially vorinostat, are currently under investigation as potential adjuncts in the treatment of neuroblastoma. The effect of vorinostat co-treatment on the development of resistance to other chemotherapeutic agents is unknown. In the present study, we treated two human neuroblastoma cell lines [SK-N-SH and SK-N-Be(2)C] with progressively increasing doses of doxorubicin under two conditions: with and without vorinsotat co-therapy. The resultant doxorubicin-resistant (DoxR) and vorinostat-treated doxorubicin resistant (DoxR-v) cells were equally resistant to doxorubicin despite significantly lower P-glycoprotein expression in the DoxR-v cells. Whole genome analysis was performed using the Ilumina Human HT-12 v4 Expression Beadchip to identify genes with differential expression unique to the DoxR-v cells. We uncovered a number of genes whose differential expression in the DoxR-v cells might contribute to their resistant phenotype, including hypoxia inducible factor-2. Finally, we used Gene Ontology to categorize the biological functions of the differentially expressed genes unique to the DoxR-v cells and found that genes involved in cellular metabolism were especially affected.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 781. doi:1538-7445.AM2012-781
Abstract 782: Development of folate receptor positive drug-resistant cell lines and strategies to overcome drug resistance
Authors: Reddy Joseph A. , Dorton Ryan , Bloomfield Alicia , Nelson Melissa , Leamon Christopher
Published: August 2012

In support of our clinical strategy to treat folate receptor (FR)-positive platinum resistant ovarian cancer patients with the folate desacetylvinblastine (DAVLBH) conjugate, EC145, we created two FR-expressing DAVLBH resistant cell lines (named KB-DR and NCI/ADR-FR). Results from a calcein efflux assay confirmed that the KB-DR and NCI/ADR-FR cell lines both express high levels of an efflux pump, and subsequent flow cytometry analysis using an anti-p-glycoprotein (pgp) antibody (MRK-16) confirmed pgp overexpression. As predicted, these DAVLBH-resistant cell lines were also less sensitive to single agent EC145. However, when tested in combination with known pgp inhibitors, such as lapatinib or verapamil, substantially enhanced cell killing activity was observed. Furthermore, folate conjugates of non-pgp substrates, such as folate-tubulysin and a folate-epothilone, were also found to be highly active against these drug-resistant cell lines. In subsequent studies, we created a cisplatin resistant cell line (named KB-CR) and found that it remained just as susceptible to EC145 as the parent KB cells, suggesting that cisplatin-resistance did not affect FR function or sensitivity to folate-targeted microtubule inhibitors. Since the development of drug resistance did not appear to alter the function or exploitability of the FR, these new models will be useful for testing novel folate-targeted strategies for the treatment of difficult-to-treat cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 782. doi:1538-7445.AM2012-782
Abstract 793: Evolutionary therapy modeling for multidrug resistance: A novel concept of false drug
Authors: Kam Yoonseok , Khin Zayar , Gatenby Robert A.
Published: August 2012

The emergence of drug resistance is almost inevitably encountered during systematic cancer therapies resulting in treatment failure and tumor progression. The multidrug resistance (MDR), mediated by xenobiotic metabolism, is among the most well-known and well-studied mechanisms for drug resistance. Although MDR emergence is an evolutionary process, cancer therapies rarely incorporate evolutionary dynamics into their design. Here we present a study to develop a cancer treatment strategy targeting the metabolic cost of MDR and its evolutionary consequence. Through a new therapeutic strategy that reduces the fitness and proliferation of resistant cells by forcing them to use excess energy, we expect to stabilize the tumor volume by maintaining a constant population of sensitive cells and suppressing emergence of resistance. P-glycoprotein (PGP) is the best-known multidrug transporter responsible for MDR and lowers the intracellular drug concentration by an active drug export. A doxorubicin-resistant cell line MCF-7/dox showed significant overexpression of PGP pump when compared to MCF-7/wt, the parental drug-sensitive cell line. We focused on the metabolic energy cost due to the overexpression of the pump protein and its activity which requires about 2 ATP for each molecule of drug extruded. We hypothesized that the cost requires diversion of some resources which are, therefore, not available for proliferation thus reducing the evolutionary fitness of resistant cells. As expected, MCF-7/dox showed higher glycolytic activity and higher glucose demand for the growth and survival compared to the parental cell line MCF-7/wt. Due to the increased glucose consumption, MCF-7/dox appeared to be less competitive in a mixed culture with MCF-7/wt when the glucose resource was limited. We were able to increase the glycolytic activity further by applying other PGP substrates including verapamil at a non-cytotoxic dose. From these results, we propose a novel therapy using a “false drug,” which is not cytotoxic but nevertheless exported by PGP. The expenditure of resources required to extrude the false drug without any survival benefit is expected to further reduce the fitness of the MDR phenotype. When the mixed population was treated with verapamil at a non-lethal dosage, the drug-resistant population was significantly decreased further than when verapamil was not present. 2-deoxy glucose (2-DG), a glycolysis inhibitor, showed synergistic effect with verapamil in further reducing the MCF-7/dox population size.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 793. doi:1538-7445.AM2012-793
Abstract 797: Gemcitabine resistant pancreatic cancer cell lines acquire an invasive phenotype with characteristics of EMT
Authors: Samulitis Betty , Wisner Lee , Dorr Robert , Landowski Terry H.
Published: August 2012

Gemcitabine is currently the standard first line treatment for patients with pancreatic cancer, however overall survival remains poor, and few options are available for patients that fail gemcitabine therapy. To identify potential molecular targets in gemcitabine refractory pancreatic cancer, we have developed gemcitabine resistant cell lines. Resistant cells were obtained by continuous exposure of MiaPaCa2 (MP) cells with increasing concentrations of gemcitabine. Stable cell lines were obtained with up to 500-fold resistance to gemcitabine. Characterization of the drug resistance cell lines has demonstrated no significant changes in gemcitabine uptake or metabolic pathways. The growth rate and doubling time of the drug resistant cell line is very similar to the parental drug sensitive cells with only small differences in response to gemcitabine. Cross resistance profiles demonstrate approximately 100-fold cross resistance to pyrimidine nucleoside cytarabine, but no resistance to the same in class agents, azacytidine and decitabine. Similarly, the gemcitabine resistant (GR) cell line displays 20-fold and 10-fold cross resistance to the purine nucleosides clofarabine and cladribine, respectively, but no differential response to fludarabine. Cell morphology of the drug resistant cells demonstrates characteristics of an epithelial-mesenchymal transition (EMT). Similarly, the GR cells are 5-fold more invasive in matrigel assays in vitro, and are significantly more aggressive in vivo. Microarray analysis demonstrated induced expression of several signaling pathways associated with EMT, including c-kit, TGFβ, and the JAG1/Notch axis. These data suggest that the primary mechanism of gemcitabine resistance is not related to alterations in drug uptake or metabolism, rather, the phenotype may reflect the selection of an intrinsic mechanism of enhanced cell survival. They further support a relationship between chemoresistance and EMT, and provide evidence for molecular pathways that may emerge as therapeutic targets in refractory pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 797. doi:1538-7445.AM2012-797
Abstract 800: Formation of chemotherapy resistance-inducing fatty acids by mesenchymal stem cells depends on COX-1, thromboxane synthase and intracellular calcium
Authors: Houthuijzen Julia M. , Roodhart Jeanine M.L. , Daenen Laura G.M. , Voest Emile E.
Published: August 2012

The development of resistance to chemotherapy is considered to be one of the most important obstacles to continued effective treatment of cancer in patients. We recently have identified an important mechanism that is responsible for systemic resistance to chemotherapy. Circulating mesenchymal stem cells (MSCs) activated by chemotherapy secrete specific polyunsaturated fatty acids that confer resistance to a broad spectrum of anti-cancer agents. These factors were identified to be two distinct platinum-induced polyunsaturated fatty acids (PIFAs) 12-S-keto-5,8,10-heptadecatrienoic acid (KHT) and 4,7,10,13-hexadecatetraenoic acid (16:4(n-3)) that were able to induce chemotherapy resistance in picomolar concentrations. Interestingly, the production of these PIFAs is restricted to MSCs and mouse embryonic fibroblasts (MEFs), other stem cells like hematopoietic stem cells and cancer stem cells are not able to form the PIFAs after cisplatin stimulation. Research from our lab showed that the production of these PIFAs can be blocked by cyclooxygenase-1 (COX-1), thromboxane A synthase (TXAS) and intracellular calcium inhibitors, suggesting that these are important in the production of the PIFAs, and indicating that the PIFAs are formed in the pathways of arachidonic acid (AA) and eicosapentaenoic acid (EPA). Lipid peroxidation with subsequent release of oxygen radicals could be a trigger for the formation of PIFA. We therefore tested whether reactive oxygen species (ROS) were involved in the production of the PIFAs. Neither increasing ROS by hydrogen peroxide, nor scavenging of ROS by glutathione in the MSCs influenced the level of resistance to chemotherapy in mice. In addition, intracellular ROS levels in the MSCs treated with cisplatin for various intervals did not change as was determined by DCFDA fluorescence. Our findings provide a new paradigm on how MSCs can induce a systemic protection against chemotherapy through the secretion of two distinct fatty acids that are formed in response to platinum-containing chemotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 800. doi:1538-7445.AM2012-800