bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 386: Epigenome-wide association study to predict breast cancer risk in European Prospective Investigation into Cancer and Nutrition (EPIC) cohort
Authors: Ambatipudi Srikant , Chajes Veronique , Calvez-Kelm Florence Le , Cuenin Cyrille , Durand Geoffroy , Romieu Isabelle , Herceg Zdenko
Published: May 2015

Aberrant DNA methylation (DNAm) in blood has been used as an epigenetic marker of cancer risk although, the significance of DNAm changes in surrogate tissues as a marker of predicting breast cancer risk remains elusive. This may be potentially accounted by the fact that there are very few study cohorts to understand the significance of DNA methyation prospectively. We examined the potential of DNAm in peripheral blood as a marker of breast cancer risk in a nested case-control cohort of European Prospective Investigation into Cancer and Nutrition (EPIC) study. The study cohort involved 451 female incident breast cancer cases and matched controls (matched for center, age, date of blood collection and menopausal status). Majority of breast cancer cases were localized (47%) and receptor positive (83.1%) while a smaller proportion of samples were metastatic (14%) and 20% of the cases were triple negative. Methylation levels were measured across 485,777 CpG sites using the Illumina HumanMethylation 450K BeadChip array. The cross-reactive probes and polymorphic CpGs were filtered during the analysis. Methylation values for all the probes thus obtained were compared between cases and matched controls using logistic regression model with adjustments for potential confounders. We found differential methylation across 185 probes (P<0.0005) and we believe that these probes may serve as potentially useful surrogate markers for identification of individuals with a high risk of breast cancer development. We are currently verifying and validating these findings in our study cohort and the findings will be discussed at the meeting.

Citation Format: Srikant Ambatipudi, Veronique Chajes, Florence Le Calvez-Kelm, Cyrille Cuenin, Geoffroy Durand, Isabelle Romieu, Zdenko Herceg. Epigenome-wide association study to predict breast cancer risk in European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 386. doi:10.1158/1538-7445.AM2014-386
Abstract 3861: Hyaluronan-CD44v3 interaction with oct4/sox2/nanog promotes miR-302 expression leading to self-renewal, clonal formation and cisplatin resistance in cancer stem cells from head and neck squamous cell carcinoma
Authors: Bourguignon Lilly Y W , Wong Gabriel , Earle Christine
Published: May 2015

Human Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly malignant cancer associated with major morbidity and mortality. In this study we determined that human HNSCC-derived HSC-3 cells contain a subpopulation of cancer stem cells (CSCs) characterized by a high levels of CD44v3 and aldehyde dehydrogenase-1 (ALDH1) expression. These tumor cells also express several stem cell markers (the transcription factors-Oct4, Sox2 and Nanog) and display the hallmark CSC properties of self-renewal/clonal formation and the ability to generate heterogeneous cell populations.

Importantly, hyaluronan (HA) stimulates the CD44v3 (an HA receptor) interaction with Oct4/Sox2/Nanog leading to both a complex formation and the nuclear translocation of three CSC transcription factors. Further analysis reveals that microRNA-302 (miR-302) is controlled by an upstream promoter containing Oct4/Sox2/Nanog binding sites, while chromatin immunoprecipitation (ChIP) assays demonstrate that stimulation of miR-302 expression by HA/CD44 is Oct4/Sox2/Nanog-dependent in HNSCC-specific CSCs. This process results in suppression of several epigenetic regulators (AOF1/AOF2 and DNMT1) and the upregulation of several survival proteins (cIAP-1, cIAP-2 and XIAP) leading to self-renewal, clonal formation and cisplatin resistance. These CSCs were transfected with a specific anti-miR-302 inhibitor in order to silence miR-302 expression and block its target functions. Our results demonstrate that the anti-miR-302 inhibitor not only enhances the expression of AOF1/AOF2 and DNMT1, but also abrogates the production of cIAP-1, cIAP-2 and XIAP and HA/CD44v3-mediated cancer stem cell functions. Taken together, these findings strongly support the contention that the HA-induced CD44v3 interaction with Oct4/Sox2/Nanog signaling plays a pivotal role in miR-302 production leading to AOF1/AOF2/DNMT1 downregulation and survival protein activation. All of these events are critically important for the acquisition of cancer stem cell properties including self-renewal, clonal formation and chemotherapy resistance in HA/CD44v3-activated head and neck cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Lilly Y W Bourguignon, Gabriel Wong, Christine Earle. Hyaluronan-CD44v3 interaction with oct4/sox2/nanog promotes miR-302 expression leading to self-renewal, clonal formation and cisplatin resistance in cancer stem cells from head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3861. doi:10.1158/1538-7445.AM2014-3861
Abstract 3865: ATOH8 depletion can reprogram noncancer stem cells into cancer stem cells
Authors: Song Yangyang , Guan Xin-Yuan
Published: May 2015

Introduction:

The development of hepatocellular carcinoma (HCC), one of the most lethal of human malignancies, is caused by the accumulation of multiple genetic and epigenetic alterations. Recent advances in cancer stem cell (CSC) study have associated the poor prognosis of cancer with CSC. ATOH8 is a nucleus factor with an obvious structural similarity to the Drosophila proneural gene atonal. The aim of this study is to investigated the role of ATOH8 in CSC and its therapeutic potentials for HCC treatment.

Experimental procedures:

The clinical significance of ATOH8 in a cohort of 242 HCC cases was assessed by clinical correlation and Kaplan-Meier survival analyses. ATOH8-overexpressing and scliencing cell model was generated by Lentivirus system to detect its functional roles in HCC both in vivo and in vitro. iPS technology is used to analyze effects of ATOH8 on CSCs.

Result:

Downregulation of ATOH8 was detected in over 40% of 242 pairs primary HCC cases, which was significantly associated with disease free survival (P=0.031), high level of AFP (P=0.03) and diferentiation (P=0.01). Functional studies demonstrate the tumor suppressive role of ATOH8 in HCC, including the inhibition of cell growth, cell proliferation, tumor formation in SCID mice and cell motility when ATOH8 was introduced into HCC cells. Further study finds that ATOH8 depletion can enhance the stemness of HCC including the tumorigenicity and abilities for self-renewal, differentiation and chemo-resistance by repressing the transcription of stemness-related genes such as OCT4, NANOG, SOX2, AFP, and HCC cancer stem cell (CSC) surface markers such as CD24 and CD133. One interesting finding in this study is that knockdown of ATOH8 could increase CD133+ cell population in QSG7701 and BEL7402 cells. CD133+ cells induced by ATOH8 depletion were flow-sorted and their CSC property was characterized. The results found that flow-sorted CD133+ cells induced by ATOH8 depletion possessed most characteristics of CSC including the capacity to self-renew, differentiation, sustained proliferation and chemoresistance. In addition, ATOH8 depletion could enhance the frequency of pluripotent stem cells (iPSC) generation induced by 4 factors (OCT4, Sox2, Klf4 and cMyc). All these data strongly suggest that a non-CSC could be reprogrammed into a CSC under some circumstance such as downregulation of ATOH8.

Conclusion:

This study demonstrates that ATOH8 plays an important role in HCC development, and provides a potential new HCC therapeutic approach that ATOH8 could increase the chemosensitivity of HCC cells to chemotherapeutics as demonstrated in this study.

Citation Format: Yangyang Song, Xin-Yuan Guan. ATOH8 depletion can reprogram noncancer stem cells into cancer stem cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3865. doi:10.1158/1538-7445.AM2014-3865
Abstract 3867: ROCK1 inhibition promotes the self-renewal of a novel mouse mammary cancer stem cell
Authors: Maurer Jochen , Castro David J. , Kim Mihee , Oshima Robert G.
Published: May 2015

The differentiation of stem-like tumor cells may contribute to the cellular heterogeneity of breast cancers. We report the propagation of highly enriched mouse mammary cancer stem cells that retain the potential to differentiate both in vivo and in culture and their use to identify chemical compounds that influence both self-renewal and differentiation. We identify epithelial tumor initiating cells (ETICs) that express lineage markers of both basal and luminal mammary cell lineages and retain the potential, from even single cells, to generate heterogeneous tumors similar to the tumor of origin. ETICs can progress through a Rho associated coiled-coil containing protein kinase 1 (ROCK1) dependent, epithelial to mesenchymal transition to generate mesenchymal tumor initiating cells (MTICs) capable of initiating tumors of limited heterogeneity. The propagation of ETICs may allow for the identification of new therapeutic compounds that may inhibit or prevent progression of some types of breast cancer.

Citation Format: Jochen Maurer, David J. Castro, Mihee Kim, Robert G. Oshima. ROCK1 inhibition promotes the self-renewal of a novel mouse mammary cancer stem cell. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3867. doi:10.1158/1538-7445.AM2014-3867
Abstract 3872: Identification and characterization of ITGA7 as cancer stem cell marker in esophageal squamous cell carcinoma (ESCC)
Authors: Ming Xiaoyan , Fu Li , Zhang Liyi , Guan Xinyuan
Published: May 2015

Cancer stem cells (CSCs) are widely accepted as a specific subpopulation of cells responsible for cancer initiation and progression. CSCs have yet to be identified in ESCC that have an increasing incidence in developed countries. Our recent study in esophageal squamous cell carcinoma (ESCC) has led to the identification of ITGA7 as a functional CSCs marker. ITGA7+ cell population is endowed with stem cell-like properties and high tumorigenic and metastatic potential. ITGA7+ CSCs isolated from ESCC cell lines possessed higher self-renewal activity and were sufficient for tumor initiation, differentiation, and metastasis compared to ITGA7- ESCC cells. Functional studies using lentiviral-based overexpression and suppression systems demonstrated that ITGA7 can promote tumor initiation and metastasis through a deregulated FAK-Raf-MEK1/2-ERK signaling pathway and epithelial-mesenchymal transition. Further characterization of ITGA7+ population may provide a prognostic biomarker for ESCC outcome prediction and a potential therapeutic target.

Citation Format: Xiaoyan Ming, Li Fu, Liyi Zhang, Xinyuan Guan. Identification and characterization of ITGA7 as cancer stem cell marker in esophageal squamous cell carcinoma (ESCC). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3872. doi:10.1158/1538-7445.AM2014-3872
Abstract 3879: Crosstalk initiated by endothelial cells endows head and neck cancer stem cells with an invasive phenotype
Authors: Kim Hong S. , Zhang Zhaocheng , Warner Kristy A. , Finkel Kelsey A. , Adams April , Nor Jacques E.
Published: May 2015

Head and neck squamous cell carcinomas contain a sub-population of uniquely tumorigenic cells (named cancer stem cells) that are thought to participate in metastatic dissemination. We have previously shown that head and neck cancer stem cells (HNCSC) can be identified as ALDHhighCD44high and reside within the perivascular niche, in close proximity to blood vessels. Therefore, it is possible that a crosstalk between HNCSC and endothelial cells plays a functional role in metastatic spread. Here, we hypothesize that factors secreted by endothelial cells enhance motility and invasiveness of HNCSC. We observed that endothelial cell-derived factors induced epithelial-mesenchymal transition (EMT) of unsorted head and neck squamous cell carcinoma (HNSCC) cells, as demonstrated by decreased expression of epithelial markers (e.g. Desmoplakin), enhanced expression mesenchymal cell markers (e.g. Vimentin) and transcriptional regulators of EMT (e.g. Snail), and enhanced migration of these cells. Further, endothelial cell-secreted factors enhanced the orosphere forming-ability of HNSCC plated in ultra-low attachment plates, enhanced the fraction of ALDHhighCD44high cells, and expression of Bmi-1. Similarly, HNCSC had increased number of orospheres and enhanced motility in the presence of endothelial cell-derived factors. Taken together, these data indicate that a crosstalk initiated by endothelial cells endows head and neck cancer cells with high motility and a stem-like phenotype, and suggest that endothelial cells may play an active role in the initial steps of metastatic spread. Support for this work was provided by grant R01-DE21139 from the NIH/NIDCR, and grant P50-CA97248 (University of Michigan Head Neck SPORE) from the NIH/NCI.

Citation Format: Hong S. Kim, Zhaocheng Zhang, Kristy A. Warner, Kelsey A. Finkel, April Adams, Jacques E. Nor. Crosstalk initiated by endothelial cells endows head and neck cancer stem cells with an invasive phenotype. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3879. doi:10.1158/1538-7445.AM2014-3879
Abstract 3881: A distinct DNA methylation signature defines breast cancer stem cells and predict cancer outcome
Authors: Helou Rita E. , Wicinski Julien , Guille Arnaud , Adelaide Jose , Finetti Pascal , Bertucci Francois , Chaffanet Max , Birnbaum Daniel , Charafe-Jauffret Emmanuelle , Ginestier Christophe
Published: May 2015

Pluripotency of stem cells depends on epigenetic programs that regulate self-renewal and differentiation. During oncogenesis, dysregulation of these two programs leads to the development of cancer stem cells (CSCs). Recent evidence suggests that CSCs are relatively resistant to conventional therapies and responsible for metastasis formation. Deciphering these processes will help gain insight into oncogenesis and allow the development of new targeted therapies. We used a whole-genomic promoter microarray to establish the DNA methylation portrait of breast cancer stem cells (bCSC) and compared it to non-bCSC. bCSC from five breast cancer cell lines were isolated using the ALDEFLUOR assay. We identified a DNA methylation signature with 68 differentially methylated regions (DMRs) that were hypomethylated in bCSCs as compared to non-bCSCs. Using a differentiation assay we demonstrated that DMRs are rapidly hypermethylated within the first six hours following induction of CSC differentiation whereas the cells reached the steady-state within 6 days, suggesting that these DMRs are linked to early CSC epigenetic regulation. DMRs were enriched in genes coding for TGFβ signaling-related proteins. Interestingly, overexpression of TGFβ signaling genes was correlated to DMRs hypomethylation in a series of 109 breast tumors. Moreover, the tumors harboring the bCSC DMRs signature had a worse evolution than the ones with the non-bCSC DMRs signature. Our results provide evidence that bCSCs harbor a distinct DNA methylation landscape with TGFβ signaling as a key epigenetic regulator of bCSCs differentiation.

Note: This abstract was not presented at the meeting.

Citation Format: Rita El Helou, Julien Wicinski, Arnaud Guille, Jose Adelaide, Pascal Finetti, Francois Bertucci, Max Chaffanet, Daniel Birnbaum, Emmanuelle Charafe-Jauffret, Christophe Ginestier. A distinct DNA methylation signature defines breast cancer stem cells and predict cancer outcome. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3881. doi:10.1158/1538-7445.AM2014-3881
Abstract 3883: Thyroid cancer cells with low proteasome activity have therapeutic resistance
Authors: Fukusumi Takahito , Ishii Hideshi , Konno Masamitsu , Nishikawa Shimpei , Kano Yoshihiro , Hasegawa Shinichiro , Ogawa Hisataka , Hamabe Atsushi , Noguchi Kozo , Miyo Masaaki , Satoh Taroh , Doki Yuichiro , Mori Masaki , Inohara Hidenori
Published: May 2015

Background

Thyroid cancer is the most frequent endocrine malignancy with a global increasing incidence. Papillary, follicular, and anaplastic thyroid carcinomas arise from endodermal-derived follicular cells, which represent the most abundant cellular population of the thyroid gland. The recent discovery of cancer stem cells (CSCs) in a variety of tumors has changed the view of carcinogenesis and therapeutic resistance. Therefore, the identification of CSCs in thyroid cancer represents a crucial step to elucidate the mechanism of therapeutic resistance, and develop effective therapies. It was previously reported that low intrinsic proteasome activity in glioma, pancreas, prostate, and breast cancer cells correlated with therapeutic resistance and CSCs properties. We hypothesized that a therapeutic resistant cell population with intrinsically low 26S proteasome activity can also be found in thyroid cancer.

Materials and Methods

We engineered human thyroid cancer cell lines (TPC-1, FRO, and WRO) to express a green fluorescent molecule fused to the degron of ornithine decarboxylase from a retroviral vector. The green fluorescence accumulates in a small population of these cells as a result of low activity of the 26S proteasome.

Result

We identified a small population of cells with intrinsically low 26S proteasome activity in all thyroid cell lines. These populations have cisplatin, 5-FU, and radio-resistance. To further investigate differences between thyroid cancer cells with high and low proteasome activity, we studied their self-renewal capacity and tumorigenicity using an in vitro sphere-forming assay and an in vivo xenograft transplantation assay.

Conclusion

We conclude that established thyroid cancer cell lines are heterogeneous with regard to their intrinsic proteasome activity and that they contain a therapeutic resistant subpopulation of cells that can be identified by low proteasome activity. Further studies are needed to elucidate the mechanism that thyroid cancer cells with low proteasome activity have these properties.

Learning Objective

We identified thyroid cancer cells with low proteasome activity have therapeutic resistance and CSCs properties.

Citation Format: Takahito Fukusumi, Hideshi Ishii, Masamitsu Konno, Shimpei Nishikawa, Yoshihiro Kano, Shinichiro Hasegawa, Hisataka Ogawa, Atsushi Hamabe, Kozo Noguchi, Masaaki Miyo, Taroh Satoh, Yuichiro Doki, Masaki Mori, Hidenori Inohara. Thyroid cancer cells with low proteasome activity have therapeutic resistance. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3883. doi:10.1158/1538-7445.AM2014-3883
Abstract 3888: Expression of ABCG2, ALDH1A1, CD44, and CD44 variant 9 in human oral squamous cell carcinoma and its relationship with clinical factors
Authors: Tamatani Tetsuya , Takamaru Natsumi , Kinouchi Makoto , Kuribayashi Nobuyuki , Uchida Daisuke , Nagai Hirokazu , Miyamoto Youji
Published: May 2015

[Background] A cancer stem cell (cancer initiating cell, CSC) is considered capable of self -replication, self-differentiation, drug resistance, and immune evasion. Recently, CSC has become increasingly important in the treatment of malignant tumors. Cancer stem cells express specific molecules termed CSC marker, including ATP-binding cassette, G2 subfamily (ABCG2), aldehyde dehydrogenase (ALDH) 1A1, CD44, and CD44 variant 9 (CD44v9), and their expression has been reported to be the potential prognostic values. However, the prognostic values of ABCG2, ALDH1A1, CD44, and CD44v9 expression in patients with oral cancer are less understood.

[Purpose] The aims of present study were to evaluate the expression of ABCG2, ALDH1A1, CD44, and CD44v9 in oral squamous cell carcinoma (OSCC) and to elucidate the relationships among the CSC marker expression, clinical stages, histological differentiation, classification of invasion mode, lymph node metastasis and disease-free survival rate.

[Materials and Methods] Tissue specimens were obtains from 99 patients with OSCC after surgery or biopsy. Immunohistochemistry was used to assess ABCG2, ALDH1A1, CD44, and CD44v9 protein using at least 10% staining-positive cells as the definition of positive staining.

[Results] Immunohistochemical analysis of 99 cases of OSCC showed that CD44 and CD44v9 expression were strongly detected in all OSCC compared with normal epithelial cells. Twenty eight (28.2%) cases of 99 OSCC patients expressed ABCG2. There was no relationship between ABCG2 expression and clinical stages, histological differentiation, metastasis, or disease-free survival rate. There was significant association between ABCG2 expression and classification of invasion mode. Otherwise, thirty one (31.3%) cases of 99 OSCC patients expressed ALDH1A1. There was no relationship between ALDH1A1 expression and clinical stagesor metastasis. However, there was significant association between ALDH1 expression and histological differentiation, or classification of invasion mode or disease-free survivalrate. [Conclusions] These findings suggested that the expression of ALDH1A1 as CSC markers in OSCC may be good marker indicating survival in patients with OSCC.

Citation Format: Tetsuya Tamatani, Natsumi Takamaru, Makoto Kinouchi, Nobuyuki Kuribayashi, Daisuke Uchida, Hirokazu Nagai, Youji Miyamoto. Expression of ABCG2, ALDH1A1, CD44, and CD44 variant 9 in human oral squamous cell carcinoma and its relationship with clinical factors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3888. doi:10.1158/1538-7445.AM2014-3888
Abstract 3891: CD133 is associated with resistance of melanoma to multikinase inhibition
Authors: Zhou Hengbo , Abdussamad Maryam , Alomari Amani , Gaur Anirudh , Rosenthal Cynthia S. , Zapas John L. , Rosenthal Dean S.
Published: May 2015

Purpose: High-risk melanoma is a lethal cancer with a high recurrence rates and variable disease-free intervals, due to tumorigenic cell populations that are resistant to treatment. Prominin 1 (CD133) is a putative stem cell marker in a number of cancers, based on its expression in cells that possess greater tumorigenicity, motility and colony-forming ability in different types of cancer. Furthermore, Prominin 1 is highly expressed in late-stage metastatic melanoma showing its potential as a marker of a resistant cell population. Trametinib and dabrafenib are targeted kinase inhibitors recently approved by the FDA, and now widely used for treatment of melanoma, while the anthelmintic drug mebendazole, a multikinase inhibitor, also exhibits promising anticancer potential. The purpose of this study was to test the relative resistance of CD133+ and CD133- cells to these three agents, as well as to explore potential mechanisms underlying any differences.

Design: Three melanoma cell lines with different kinase mutation profiles were exposed to increasing concentrations of trametinib, dabrafenib, or mebendazole alone, or in combination, either before or after separation into CD133-positive and CD133-negative populations. Cells were then assayed for cell viability and CD133-positivity. Microarray analysis was performed on CD133-positive and CD133-negative cells to explore potential differences in gene expression profiles.

Result: In all parental cell lines, the percentages of the CD133-positive cells increased significantly (P<0.05) after high-dose drug treatment. The CD133-positive, drug resistant cells showed reduced proliferation until after the drug was removed. Correspondingly, the presorted CD133-positive population exhibited significantly higher (P<0.05) IC50s both for single and multidrug treatment. Microarray analysis revealed a significant (P<0.001, >1.5-fold) difference in expression of 265 genes in CD133-positive cells, including putative oncogenes such as POU5F1, NPM1, NES and MYC. Also, 10 of 18 ABC transporter genes were significantly (P<0.05) up-regulated in the CD133-positive population.

Conclusion: Both purified and mixed population-derived CD133 positive cells are more resistant to the three kinase inhibitors. Upregulation of ABC transporter genes and/or oncogenes may contribute to the drug resistance of CD133-positive cells.

Citation Format: Hengbo Zhou, Maryam Abdussamad, Amani Alomari, Anirudh Gaur, Cynthia S. Rosenthal, John L. Zapas, Dean S. Rosenthal. CD133 is associated with resistance of melanoma to multikinase inhibition. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3891. doi:10.1158/1538-7445.AM2014-3891
Abstract 3900: Pten deletion in SOX9+ cells leads to tumor initiating cell expansion and tumor development in mouse liver
Authors: Zeng Ni , Kopp Janel , He Lina , Sander Maike , Stiles Bangyan
Published: May 2015

Liver cancer is one of the most aggressive malignancies with a five-year survival rate less than 10%. There is thus an urgent unmet need to understand the process of liver tumorigenesis in order to develop early diagnosis and effective therapeutic treatments. Clinical studies have suggested that tumor initiating cell (TIC) activation is observed in over 70% of liver cancer samples and is closely linked with poor survival outcome after treatment. Consistent with these observations, our previous studies utilizing a Pten (loxp/loxp); Albumin-Cre+ mouse liver cancer model also confirmed the expansion of TICs during liver tumorigenesis. However, how TICs are activated and what mechanisms contribute to liver tumor development remains unclear. Here, we studied the role of tumor suppressor PTEN in TICs using the Pten (loxp/loxp); SOX9-CreER+ mouse model. Lineage tracing results indicated that in the liver SOX9+ cells possess the progenitor cell characteristics and give rise to bile duct cells and peri-portal hepatocytes later on. Pten deletion in SOX9+ cells at 4 weeks of age leads to expansion of both CK+ duct cells and HNF4+ hepatocytes in the peri-portal areas. Interestingly, we also observed tumor development at 12 months old mutant mice and close examinations revealed that the tumors are heterogeneous, indicating the contribution of TICs during this process. Together, our study suggested that the PTEN signaling is critical for TICs regulation and that TICs activation plays a key role in liver tumorigenesis.

Citation Format: Ni Zeng, Janel Kopp, Lina He, Maike Sander, Bangyan Stiles. Pten deletion in SOX9+ cells leads to tumor initiating cell expansion and tumor development in mouse liver. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3900. doi:10.1158/1538-7445.AM2014-3900
Abstract 3902: Liver cancer stem cells initiate extracellular matrix remodeling
Authors: Zhang Zhiqian , Zhao Wei , Yang Xueying , Han Haibo
Published: May 2015

Extracellular matrix is one of the major components of cancer cell's niche. It is well appreciated that extracelluar matrix undergoes remodeling during the process of tumor progression,but the causal factors that initiate extracellular matrix remodeling are poorly understood. Hepatocellular carcinoma, like many other solid tumors, is thought to be hierarchically organized heterogeneous populations of cells with the cancer stem cell compartment sitting on top. We have identified a population of hepatocellular carcinoma cells, which were defined as α2δ1+ cells, exhibiting stem cell-like properties, such as increased invasiveness, expression of stem cell associated genes (OCT4, SOX2, NANOG, and BMI1), increased self-renewal, and the ability of giving rise to both α2δ1+ and α2δ1- cells with a novel monoclonal antibody, 1B50-1, using a whole-cell subtractive immunization approach that recognizes the isoform 5 of the cell surface voltage-gated calcium channel α2δ1 subunit. In order to understand the role of extracellular matrix in the regulation of α2δ1+ hepatocellular carcinoma stem cell properties, we first compared the expression of extracellular matrix components between α2δ1+ and α2δ1- cells. Comparing with α2δ1- cells, the expression of collagen isoforms such as COL6A3, COL1A2, and COL21A1 was up-regulated, while COL1A1, COL2A1, COL6A2 were down-regulated in α2δ1+ hepatocellular carcinoma cells. Interestingly, the collagen cross-linking enzyme-lysyl oxidase (LOX) was also upregulated in α2δ1+ liver cancer stem cells. Furthermore, as a direct target of microRNA-200b which was down-regulated in α2δ1+ liver cancer stem cells, LOX is sufficient to enable α2δ1− liver cancer cells to acquire cancer stem cell-like properties such as self-renewal and tumorigenicity. Knock-down of LOX in α2δ1+ liver cancer stem cells has resulted in decrease of self-renewal and tumorigenic properties. This data suggest that hepatocellular carcinoma stem cells may initiate their niche remodeling to maintain their cancer stem cell properties.

Citation Format: Zhiqian Zhang, Wei Zhao, Xueying Yang, Haibo Han. Liver cancer stem cells initiate extracellular matrix remodeling. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3902. doi:10.1158/1538-7445.AM2014-3902
Abstract 3907: Human pancreatic cancer stem cells utilized to generate an in-vivo mouse/rat model system for screening potential drug candidates for treatment of pancreatic cancer patients
Authors: Sharma Cristian , Cleary Patrick , Gomez Esteban , Satish Shruthi , Sharma Michael , Perez Michael , Amecuza Natalee , Jani Jitesh , Punzalan Rubio , Sharma Jay P.
Published: May 2015

Cancer stem cells (CSCs) are critical for engraftment and long-term growth of many tumors, including pancreatic cancer. The Cancer Stem cells are less sensitive to conventional chemotherapies and radiation therapies, and treatments that can target CSCs are critically needed. Human Pancreatic Cancer is a heterogeneous tumor composed of tumor cells and small fraction of cancer stem cells, with high tumorigenic potential. Pancreatic cancer stem cells are phenotypically similar to the normal stem cells, they express CD133 gene and other genes characteristic of neural stem cells (Nestin) and posses self-renewal potential. The CD133+ Pancreatic CSCs have been isolated with Celprogen Media and ECM and characterized as chemo-/radio-resistant tumor-initiating cells which are responsible as one of the major factors involved in post-treatment recurrence. In order to explore the molecular properties of tumorigenic CD133+ Pancreatic CSCs that resist treatment, we isolated CD133+ Pancreatic CSCs from tumors that are recurrent and have previously received chemo-/radio-therapy. We found that the purified CD133+ Pancreatic CSCs sorted from the CD133+ Pancreatic CSC spheres express SOX2 ,CD44, Nestin and are capable of clonal self-renewal. We generated in-vivo model systems in mice and rats with these cells to screen potential drug agents for the treatment of Pancreatic Cancer patients. We were capable of generating Pancreatic tumors in mice and rats within 20 days by subcutaneously injecting 1000 Pancreatic CSCs at the hind limbs of the rodents. Within day 5 the Pancreatic CSCs were already present in the rodent's pancreas. At days 10, 15 & 20 the Pancreatic CSCs labeled with GFP were located in the rodent's pancreas. We tested various compound candidates in this model system and we were able to show decrease in Pancreatic tumor when the treatment was started at day 10. We were able to demonstrate gene signatures associated with Pancreatic CSCs in this model system. We do see a down regulation of certain cancer promoter genes in the treatment group when compared to non-treatment groups.

Citation Format: Cristian Sharma, Patrick Cleary, Esteban Gomez, Shruthi Satish, Michael Sharma, Michael Perez, Natalee Amecuza, Jitesh Jani, Rubio Punzalan, Jay P. Sharma. Human pancreatic cancer stem cells utilized to generate an in-vivo mouse/rat model system for screening potential drug candidates for treatment of pancreatic cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3907. doi:10.1158/1538-7445.AM2014-3907
Abstract 3912: The role of autophagy in prostate tumorigenesis and its therapeutic implications
Authors: Velasco Marco A. De , Kura Yurie , Ando Naomi , Fukushima Emiko , Hatanaka Yuji , Yamamoto Yutaka , Shimizu Nobutaka , Yoshimura Kazuhiro , Nozawa Masahiro , Yoshikawa Kazuhiro , Nishio Kazuto , Uemura Hirotsugu
Published: May 2015

Autophagy is a self-catabolic process that maintains intracellular homeostasis and prolongs cell survival during metabolic stress. Increasing evidence also suggests that autophagy is induced during therapeutic stress and is believed to promote drug resistance limiting the treatment efficacy of anticancer drugs. Our goal was to define the role of autophagy during prostate cancer tumorigenesis and determine the consequences of pharmacological intervention. We used a genetically engineered mouse model of prostate cancer that is based on the PSA-Cre driven inactivation of PTEN to show that autophagy is induced during tumor progression and the transformation to castration resistant prostate cancer. We also report that inhibition of autophagy by the conditional inactivation of ATG7, a gene essential for autophagosome formation, does not contribute to initiate prostate cancer. However, simultaneous inactivation of ATG7 and PTEN leads to suppressed tumor progression in castration-naïve and CRPC models. Additionally PTEN/ATG7 double gene knockout mice were more sensitive to targeted mTOR inhibition than PTEN single gene knockouts. Pharmacological inhibition of autophagy using the lysomotropic agent chloroquine synergized with everolimus to inhibit survival of human and mouse prostate cancer cells in vitro. Despite a strong antitumor activity in vitro, the combinations of everolimus and chloroquine failed to demonstrate any meaningful improvement over everolimus alone when tested in vivo with PTEN-mutant mice. In summary, our findings demonstrate that autophagy is required for prostate cancer progression and contributes to therapeutic resistance; however, pharmacological inhibition of autophagy, using a lysomotropic agent, was ineffective in producing a meaningful antitumor benefit in an autochthonous cancer system. Our preliminary findings suggest a need for further investigation before implementing the concept of autophagy inhibition into clinical trials.

Citation Format: Marco A. De Velasco, Yurie Kura, Naomi Ando, Emiko Fukushima, Yuji Hatanaka, Yutaka Yamamoto, Nobutaka Shimizu, Kazuhiro Yoshimura, Masahiro Nozawa, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. The role of autophagy in prostate tumorigenesis and its therapeutic implications. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3912. doi:10.1158/1538-7445.AM2014-3912
Abstract 3913: ATP1A1 overexpression correlates with clinical diagnosis and staging of esophageal cancer: from in vivo to human
Authors: Wu Ming-Tsang
Published: May 2015

Purpose: This study aims to identify the novel and potential upregulated genes related to secretionary or membranous proteins for the clinical diagnosis and staging of esophageal squamous cell carcinoma (ESCC).

Methods: By combining microarray-based screening, which contained at least 25,000 DNA oligonucleotide probes, of esophageal tumors from both N-nitrosomethylbenzylamine- and arecoline-induced F344 rats and 17 human ESCC specimens, we further confirmed the potential candidate genes by tissue arrays in 243 cancer tissues and 126 normal tissues of esophagus from Taiwan, Korea, and USA and by ELISA in 78 serum specimens of ESCC patients from Taiwan.

Results: Four candidate genes, including ATP1A1, SPINT2, CMTM8, and AGR2, were chosen due to their up-regulation in more than half of 17 paired tissues from 17 ESCC patients in the microarray-based screening. The four genes were verified by RT-PCR and immunohistochemical (IHC) staining in ESCC tissue specimens and only ATP1A1 (ATPase Na+/K+ transporting alpha 1 polypeptide) expression was consistent and further studied. Among the 243 cancer tissues and 126 normal tissues of esophagus, we found that the positive expressions of ATP1A1 by IHC staining were 207 (85%) of 243 in cancer tissues and 88 (70%) of 126 in normal tissues. After adjusted for age and sex, ATP1A1 overexpression had a 3.2-time (95% CI = 1.8-5.6) to be likely in cancer tissues than in normal tissues. ATP1A1 expression was also correlated to the tumor stage by IHC staining. Using the median level of 1,465.0 pg/mL of serum ATP1A1 protein expression as the cut-off point, we found that patients with stage III-IV had a 2.91-fold (1.12-7.36) likely to have high serum ATP1A1 levels than those with stage I-II after adjusting for age and sex.

Conclusion: ATP1A1 overexpression may serve as a potential noninvasive marker of the clinical diagnosis and staging for ESCC patients.

Note: This abstract was not presented at the meeting.

Citation Format: Ming-Tsang Wu. ATP1A1 overexpression correlates with clinical diagnosis and staging of esophageal cancer: from in vivo to human. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3913. doi:10.1158/1538-7445.AM2014-3913
Abstract 3915: Establishment of novel cell lines recapitulating the genetic landscape of uveal melanoma and preclinical validation of mTOR as a therapeutic target
Authors: Amirouchene-Angelozzi Nabil , Nemati Fariba , Gentien David , Lepage May-Linda , Nicolas André , Madic Jordan , Dumont Amaury , Carita Guillaume , Camonis Jaques , Desjardins Laurence , Cassoux Nathalie , Piperno-Neumann Sophie , Mariani Pascale , Sastre Xavier , Decaudin Didier , Roman-Roman Sergio
Published: May 2015

PURPOSE: Uveal melanoma is the most common primary tumor of the eye in adults. There is no standard adjuvant treatment to prevent metastases and no effective therapy in the metastatic setting. Relevant models of uveal melanoma are necessary to preclinical assessment of drugs activity. The goal of this study was to develop cell lines recapitulating the genetic landscape of uveal melanoma and identify therapeutic approaches for treatment using in vitro and in vivo models.

EXPERIMENTAL DESIGN: Tumors samples from patients or patient-derived xenografts were put into culture.The cell lines obtained were characterized for chromosomal alterations and reported recurrent mutations. They were tested for sensitivity to a selected panel of drugs including the mTOR inhibitor Everolimus. We assessed mTOR signaling activation in the cell lines and evaluated the effect of Everolimus in patient-derived xenografts.

RESULTS: We established seven uveal melanoma cell lines. All display either GNAQ or GNA11 activating mutations, three harbor BAP1 mutations, and one an EIF1AX mutation. No cell line exhibits SF3B1 mutations. mTOR pathway was shown to be activated in these cells. Everolimus reduced viability of the cell lines and significantly delayed in vivo tumor growth of 4 patient-derived xenografts.

CONCLUSIONS: Our established panel of uveal melanoma cell lines represents a relevant preclinical tool for the study of this disease. Our in vitro and in vivo data suggest that mTOR inhibition with Everolimus, most probably in combination with other agents, may be considered as a therapeutic option for the management of uveal melanoma.

Citation Format: Nabil Amirouchene-Angelozzi, Fariba Nemati, David Gentien, May-Linda Lepage, André Nicolas, Jordan Madic, Amaury Dumont, Guillaume Carita, Jaques Camonis, Laurence Desjardins, Nathalie Cassoux, Sophie Piperno-Neumann, Pascale Mariani, Xavier Sastre, Didier Decaudin, Sergio Roman-Roman. Establishment of novel cell lines recapitulating the genetic landscape of uveal melanoma and preclinical validation of mTOR as a therapeutic target. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3915. doi:10.1158/1538-7445.AM2014-3915
Abstract 3916: HSP90 mediates tumor-associated matrix metalloproteinase 2 and Cathepsin L protease activities in ovarian carcinoma
Authors: O'Brien Shane W. , Xiao Fang , Maglaty Marsia A. , Trinadad Joshua S. , Martin Lainie P. , Proia David A. , Connolly Denise C.
Published: May 2015

Ovarian cancer is the fifth leading cause of cancer-related deaths among women in the United States. At diagnosis, disease has commonly spread beyond the ovary. Ovarian cancer cells dislodge from primary tumor and spread locally throughout the abdominal cavity and lymphatics. Cancer cell shedding and colonization at other sites involves the degradation of extra cellular matrix (ECM) by tumor-associated proteases, such as matrix metalloproteinase (MMPs) and cathepsin proteases. Heat shock protein 90 (HSP90) is an ATP-dependent molecular chaperone that interacts with and stabilizes MMPs in some solid tumors. Whether HSP90 regulates cathepsin activity is currently unknown. To determine the role of HSP90 on tumor-associated MMP and cathepsin protease activities in ovarian carcinoma, HSP90 activity was inhibited using pharmacologic and RNA interference (RNAi) approaches. A small molecule inhibitor, ganetespib, and two HSP90 targeting siRNAs were used to determine the effects of HSP90 inhibition on ovarian carcinoma cell line invasion using transwell and spheroid invasion assays. The effects of ganetespib or HSP90 targeting siRNA treatment on MMP and cathepsin protease activities were assayed by gelatin zymography (MMPs), enzyme assay (cathepsins) and by dynamic imaging using protease cleavable imaging probes. The effects of ganetespib treatment on in vivo orthotopic tumor growth, dissemination and tumor associated protease activities were determined using human ovarian carcinoma xenograft models. In vitro, ganetespib treatment or expression of HSP90-targeted siRNAs inhibited transwell and spheroid invasion, and MMP-2 and cathepsin L protease activities. In vivo, ganetespib treatment resulted in decreased growth of primary tumors and disseminated tumor nodules and decreased tumor-associated MMP and cathepsin activities. Importantly, significant inhibition of MMP and cathepsin activities was detected prior to differences in tumor volume, demonstrating rapid functional response to the drug. These results show that HSP90 regulates ovarian carcinoma-associated proteolytic activities that are essential to tumor progression and dissemination. They also point to the potential utility of HSP90 inhibition as a therapeutic strategy for the treatment of ovarian cancer.

Citation Format: Shane W. O'Brien, Fang Xiao, Marsia A. Maglaty, Joshua S. Trinadad, Lainie P. Martin, David A. Proia, Denise C. Connolly. HSP90 mediates tumor-associated matrix metalloproteinase 2 and Cathepsin L protease activities in ovarian carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3916. doi:10.1158/1538-7445.AM2014-3916
Abstract 393: Genome-wide molecular characterization of CIMP positive stage III colon cancer using cDNA microarray analysis
Authors: Jeon Hongjae , Kim Se Hyun , Park Kyu Hyun , Jeung Hei-Cheul , Kim Nam Kyu , Jung Minkyu , Lee Kang Young , Park Chan Hee , Rha Sun Young , Chung Hyun Cheol , Ahn Joong Bae
Published: May 2015

Background: The CpG island methylator phenotype (CIMP) is a distinctive subtype of colon cancers, which leads to the loss of tumor suppressor gene functions by epigenetic regulation. However, molecular characteristics of CIMP+ cancers are not fully understood. Here, we aimed to elucidate the different patterns of gene expression according to the CIMP status.

Method: 158 patients with stage III colon cancer were enrolled for the analysis of CIMP status. Pyrosequencing was used to examine the methylation status of 7 CpG island loci (p14, p16, MINT1, MINT2, MINT31, hMLH1, and WNT5a) in DNA extracted from formalin-fixed paraffin-enbedded specimens. Gene expression analyses of the same samples were also performed using a human cDNA microarray to identify molecular signatures.

Result: Among the 158 patients, 31 (19.3%) were CIMP+. Microarray results revealed distinctive gene expression profiles between CIMP+ and CIMP- cancers. Among 57 genes which showed significant changes between CIMP+ and CIMP- cancers, Axin2, the canonical Wnt suppressor, displayed the strongest correlation with the CIMP status (p=0.007). Axin2 was downregulated in CIMP+ cancers compared to CIMP- cancers (p=0.005). In terms of disease-free survival (DFS), tumors with low Axin2 expression showed poor prognosis compared to tumors with high Axin2 expression in microsatellite stable (MSS) patients (p=0.038), while there were no significant changes in DFS of microsatellite instable (MSI) patients (p=0.32). These findings indicate the clinical importance of epigenetic silencing of Axin2 and the subsequent activation of Wnt signaling pathway in MSS colon cancer patients.

Conclusion: Axin2 is downregulated in CIMP+ stage III colon cancer patients and the consequent decreased expression of Axin2 is a poor prognostic factor for the DFS in MSS patients.

Citation Format: Hongjae Jeon, Se Hyun Kim, Kyu Hyun Park, Hei-Cheul Jeung, Nam Kyu Kim, Minkyu Jung, Kang Young Lee, Chan Hee Park, Sun Young Rha, Hyun Cheol Chung, Joong Bae Ahn. Genome-wide molecular characterization of CIMP positive stage III colon cancer using cDNA microarray analysis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 393. doi:10.1158/1538-7445.AM2014-393