bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2235: miR-200c reduces P-gp mediated MDR and metastasis by targeting JNK2/c-Jun signaling pathway in colon cancer
Authors: Li Qi
Published: August 2015

MicroRNA-200c (miR-200c) recently emerged as an important regulator of tumorigenicity and cancer metastasis, however, its role in regulating multidrug resistance (MDR) remains unknown. In the current study, we found that the expression levels of miR-200c in recurred and metastatic colorectal cancers (CRC) were significantly lower, while the JNK2 expression was higher compared to primary tumors. We showed that in MDR CRC cells, miR-200c targeted the 3′UTR of JNK2 gene. Over-expression of miR-200c attenuated the levels of p-JNK, p-c-Jun, P-gp and MMP-2/-9, the downstream factors of JNK signaling pathway, resulting in increased sensitivity to chemotherapeutic drugs, which was accompanied by heightened apoptosis and decreased cell invasion and migration. Moreover, in an orthotopic MDR CRC mouse model, we demonstrated that over-expression of miR-200c effectively inhibited the tumor growth and metastasis. At last, in the tumor samples from locally advanced CRC patients with routine post-surgical chemotherapy, we observed an inverse correlation between the levels of mRNA expression of miR-200c and JNK2, ABCB1, MMP-9 thus predicting patient therapeutic outcomes. In summary, we found that miR-200c negatively regulated the expression of JNK2 gene and increased the sensitivity of MDR CRC cells to chemotherapeutic drugs, via inhibiting the JNK2/p-JNK/p-c-Jun/ABCB1 signaling. Restoration of miR-200c expression in MDR CRC may serve as a promising therapeutic approach in MDR induced metastasis.

Citation Format: Qi Li. miR-200c reduces P-gp mediated MDR and metastasis by targeting JNK2/c-Jun signaling pathway in colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2235. doi:10.1158/1538-7445.AM2015-2235
Abstract 2243: Alterations in the binding of Meis proteins to HoxB13 or to DNA promote prostate cancer progression
Authors: Brechka Hannah J. , Isikbay Masis , Bhanvadia Raj , Vander Griend Donald
Published: August 2015

Intro: One of the first germline mutations shown to confer an increased risk of early-onset prostate cancer (PrCa) is found in the Meis-binding domain of Homeobox B13 (HoxB13). Neither the function of this mutation nor the role of Meis proteins in PrCa has been elucidated. Meis proteins normally function as Hox gene cofactors, and regulate proliferation and cell fate. We hypothesize that disruption in normal Meis binding, either to transcriptional cofactors or DNA elements, is sufficient to alter gene transcription and increase progression of PrCa.

Methods: Meis1/2 expression was used to stratify outcomes of men with Gleason 6/7 tumors in a retrospective bioinformatics analysis. Meis1/2 mRNA expression in cell lines was determined by qRT-PCR, and isoform distribution determined by TA-TOPO cloning. Cell number over time was determined for lines stably overexpressing Meis2E or A as compared to GFP in LNCaP and CWR-22Rv1.

Results: We found that men diagnosed with intermediate Gleason scores and low expression of Meis had a worse prognosis than men with high levels of Meis. We found lower Meis mRNA expression in PrCa cell lines as compared to normal prostate epithelial cells. We determined that a variety of Meis2 isoforms are expressed in both cancer and normal, and the aggressive PrCa cell line CWR22Rv1 had a higher level of Meis2 isoforms with abrogated DNA-binding homeodomains. LNCaP cells overexpressing Meis2A showed significantly lower cell number over five days than GFP or Meis2E expressing cells.

Conclusions: Full length Meis proteins may act as tumor suppressors while the homeodomain-less isoforms may act as oncogenes in the context of PrCa. This is innovative because we are the first to look at the role of Meis proteins in PrCa, and significant because it's linked to evidence involving mutations in HoxB13.

Citation Format: Hannah J. Brechka, Masis Isikbay, Raj Bhanvadia, Donald Vander Griend. Alterations in the binding of Meis proteins to HoxB13 or to DNA promote prostate cancer progression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2243. doi:10.1158/1538-7445.AM2015-2243
Abstract 2249: TERT promoter mutation as poor prognosis marker in glioblastoma via sphere formation and self- renewal capacity
Authors: Lee Jae-Ho , Lee Hyunsu , Woo Seon Rang , Joo Kyeung-Min , Park KeonUk
Published: August 2015

Telomerase reverse transcriptase (TERT) activity was increased allowing the maintenance of telomere length in cancers. TERT promoter mutation has been reported in a variety of cancers, especially in glioblastoma (GBM) with high frequency. In present study, we screened TERT promoter mutation in 25 GBMs and analyzed the results with their respective genetic profile and its renewal capacity by in vitro sphere formation. TERT promoter mutation (C228T, C250T) was found in 16 of 25 GBMs (64.0%) and was associated with male (p < 0.01). They showed inverse correlations with IDH1 and ATRX mutations and a positive correlation with EGFR amplification though it did not show significance. GBM with sphere formation harbored higher frequency of TERT promoter mutation (91.6%) than those without sphere formation (27.3%; p = 0.01), which suggest that TERT mutation promotes self-renewal capacity of GBM. GBM with TERT mutations showed a shorter survival than those without TERT mutation in univariate analysis (median, 83.6 vs. 123.8 weeks; p = 0.045). These results suggested that TERT promoter mutation affect poor prognosis of GBM via promoting self- renewal capacity.

Citation Format: Jae-Ho Lee, Hyunsu Lee, Seon Rang Woo, Kyeung-Min Joo, KeonUk Park. TERT promoter mutation as poor prognosis marker in glioblastoma via sphere formation and self- renewal capacity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2249. doi:10.1158/1538-7445.AM2015-2249
Abstract 2258: Myc drives Pten/ p53-deficient proliferation and metastasis due to Il6-secretion and Akt-suppression via Phlpp2
Authors: Nowak Dawid G. , Cho Hyejin , Herzka Tali , Wang Victoria M.Y. , Senturk Serif , DeMarco Daniel V. , Ding David , Fellmann Christof , Beinortas Tumas , Kleinman David , Watrud Kaitlin , Chen Muhan , Wilkinson John E. , Castillo-Martin Mireia , Cordon-Cardo Carlos , Robinson Brian D. , Trotman Lloyd C.
Published: August 2015

The sporadic transition from indolent to metastatic disease is a hallmark of prostate cancer (PC) and frequently involves deletion of PTEN and TP53. We recently recapitulated metastasis of Pten/ Trp53-mutant PC in mouse using the RapidCaP system and surprisingly, we found that it is driven by Myc, rather than Akt activation.

Here, we show that cell-cell communication by Il6 drives this Akt-Myc switch through activation of the Akt-inactivating phosphatase Phlpp2. Primary cells revealed that loss of Pten/ Trp53 triggers secretion of the Il6 cytokine when these genes are deleted together, but not separately. Il6 then communicates a downstream program of Stat3-mediated Myc activation, which drives cell proliferation. Abrogation of Myc activity by Myc inhibition with the JQ1 bromodomain inhibitor, Myc-RNAi, and Myc-CRISPR/ Cas9 approaches inhibited proliferation. We validated these findings in vivo, where peak proliferation in Pten/ Trp53 mutant primary and metastatic PC did not correlate with activated Akt, but with Stat3/ Myc activation instead. Most notably, we found that Myc strongly activates the Akt phosphatase Phlpp2 in primary cells and RapidCaP metastasis, and showed genetically that Phlpp2 is essential for dictating proliferation and Myc-mediated suppression of Akt.

Collectively, our data reveal competition between two proto-oncogenes: Myc and Akt, which ensnarls the Phlpp2 gene to facilitate Myc-driven metastasis.

Citation Format: Dawid G. Nowak, Hyejin Cho, Tali Herzka, Victoria M.Y. Wang, Serif Senturk, Daniel V. DeMarco, David Ding, Christof Fellmann, Tumas Beinortas, David Kleinman, Kaitlin Watrud, Muhan Chen, John E. Wilkinson, Mireia Castillo-Martin, Carlos Cordon-Cardo, Brian D. Robinson, Lloyd C. Trotman. Myc drives Pten/ p53-deficient proliferation and metastasis due to Il6-secretion and Akt-suppression via Phlpp2. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2258. doi:10.1158/1538-7445.AM2015-2258
Abstract 2260: Defining molecular mechanisms linking Endophilin A2 to metastasis in human breast cancer models
Authors: Baldassarre Tomas , Watt Kathleen , Truesdell Peter , Schneider Mark , Sengupta Sandip , Craig Andrew WB
Published: August 2015

Breast cancers in the human epidermal growth factor receptor 2 (HER2) and triple-negative breast cancer (TNBC) subtypes have high rates of tumor metastasis. Tumor metastasis is driven by formation of invadopodia that degrade extracellular matrix (ECM) in basement membranes to spread locally and colonize distant sites. Endophilin A2 (Endo II) is an adaptor protein that coordinates internalization and trafficking of receptors that drive invadopodia formation and breast cancer metastasis. We have recently identified Endo II as a positive regulator of human TNBC metastasis, invadopodia formation, epidermal growth factor receptor (EGFR) internalization and signaling. Here, we extend these studies of Endo II to HER2 breast cancers, and define molecular mechanisms that link Endo II to invadopodia formation and cell invasion. Analysis of Endo II expression in human invasive ductal carcinomas revealed significantly high expression of Endo II in HER2 primary tumors, and significantly higher expression in paired lymph node metastases compared to other subtypes. We also observed that high levels of Endo II mRNA was associated with reduced rates of relapse free survival in patients with lymph node positive, estrogen receptor negative tumors. This correlates with our findings that Endo II promotes invadopodia formation and breast cancer cell invasion. Mechanistically, these defects may be due to reduced EGFR signaling and lowered expression of epithelial-mesenchymal transition (EMT) signature genes observed in Endo II knock-down (KD) cells. We are currently validating these results in mammary orthotopic tumor xenograft models of HER2 and TNBC cell models with stable Endo II KD. Together, these findings identify high levels of Endo II in high risk breast cancer subtypes, with high expression of EMT genes, and a potential link between Endo II levels and poor prognosis in breast cancer patients.

Citation Format: Tomas Baldassarre, Kathleen Watt, Peter Truesdell, Mark Schneider, Sandip Sengupta, Andrew WB Craig. Defining molecular mechanisms linking Endophilin A2 to metastasis in human breast cancer models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2260. doi:10.1158/1538-7445.AM2015-2260
Abstract 2266: CEACAM6 promotes tumor angiogenesis and vasculogenic mimicry in gastric cancer via FAK signaling
Authors: Liu Bingya , Zang Ming-de , Li Jian-fang , Su Li-ping , Zhu Zheng-gang , Yan Min
Published: August 2015

CEACAM6 is a glycosylphosphatidylinositol (GPI)-linked immunoglobulin superfamily member that is implicated in a variety of human cancers. In our previous study, we reported that CEACAM6 was overexpressed in gastric cancer (GC) tissues and promoted cancer metastasis. The purpose of this study is to determine the role of CEACAM6 in tumor angiogenesis and vasculogenic mimicry (VM). We found that overexpression of CEACAM6 promoted tubular formation of human umbilical vein endothelial cells (HUVECs) and VM formation in GC. While opposing results were achieved in CEACAM6 knock-down groups. Interestingly, we found that mosaic vessels formed by HUVECs and GCs were observed in vitro by 3D-culture. Moreover, overexpression of CEACAM6 in GCs promoted tumor growth, VEGF secretion and VM structures in vivo. In accordance with these observations, we found that phosphorylation of FAK and phosphorylation of paxillin were up-regulated in CEACAM6-overexpressing GCs, and FAK inhibitor Y15 could reduce tube and VM formation. These findings suggest that CEACAM6 promotes tumor angiogenesis and VM may via FAK signaling, and CEACAM6 maybe a new potential target for cancer anti-vascular treatment.

Citation Format: Bingya Liu, Ming-de Zang, Jian-fang Li, Li-ping Su, Zheng-gang Zhu,Min Yan. CEACAM6 promotes tumor angiogenesis and vasculogenic mimicry in gastric cancer via FAK signaling. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2266. doi:10.1158/1538-7445.AM2015-2266
Abstract 2267: Defining roles of SIN3 isoforms in breast cancer metastasis
Authors: Lewis Monica J. , Liu Jianzhong , Hurst Douglas R.
Published: August 2015

Metastasis continues to be the most difficult clinical challenge for breast cancer. These patients have unacceptable survival rates that have not changed in the past 20 years. Therefore, more effective therapeutic options are needed. The purpose of this study is to better understand molecular mechanisms of the SIN3 chromatin complexes that have been functionally associated with breast cancer progression to identify novel targeting strategies. Alteration of the composition of SIN3 complexes regulates the metastatic potential of breast cancer cells; and inhibition of SIN3 complexes induces differentiation and inhibits invasion of breast cancer cells. However, differences in the function of SIN3 isoforms (SIN3A and SIN3B) in breast cancer metastasis have not been characterized. To better define the role of SIN3 isoforms in breast cancer metastasis, we generated stable knockdown of SIN3 isoforms individually and in combination using 3 non-overlapping shRNA in two different metastatic breast cancer cell lines (MDA-MB-231 and -435). No significant change was noted in the proliferation rate of the transduced cells in vitro. Stable knockdown of SIN3B caused a significant decrease in invasion through Matrigel (28 ± 4 invaded cells/field compared to 50 ± 8 for control; p = 0.027) using a modified Boyden chamber that was corroborated by the decreased presence of stellate projections and a more epithelial phenotypic growth in 3D. Surprisingly, stable knockdown of SIN3A significantly increased invasion through Matrigel (98 ± 14 invaded cells/field; p = 0.008) and increased the presence of stellate projections in the 3D growth assay. Dual knockdown of SIN3A and SIN3B caused a significant decrease in invasiveness (19 ± 5 invaded cells/field; p = 0.003) and decreased presence of stellate projections similar to the phenotype noted with individual knockdown of SIN3B. These results were confirmed in vivo with an experimental metastasis assay (lateral tail vein injection in athymic nude mice) in which SIN3B knockdown significantly decreased lung metastasis (70% decrease compared to control; p = 0.009) and SIN3A knockdown increased metastasis (163% increase compared to control; p = 0.096). These results demonstrate key functional differences between SIN3 isoforms in regulating the process of metastasis. Our data suggests metastasis suppressive roles of SIN3A and metastasis promoting roles of SIN3B that will be important in discovering novel therapeutic strategies for metastatic breast cancer patients.

Citation Format: Monica J. Lewis, Jianzhong Liu, Douglas R. Hurst. Defining roles of SIN3 isoforms in breast cancer metastasis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2267. doi:10.1158/1538-7445.AM2015-2267
Abstract 227: Characterization of single cells from dissociated solid tumors
Authors: Middlebrook Aaron J. , Niknam Shahryar , Ruitenberg Joyce , Mach Albert J. , Suni Maria , Porter Warren , Hahn Friedrich , Snowden Eileen , Blaesius Rainer , Ghanekar Smita
Published: August 2015

The heterogeneous nature of solid tumors, coupled with the relatively small sample size of available biopsies, has led to an emerging need to glean as much information as possible from these valuable specimens. Current approaches to solid tumor analysis fail to completely reveal the diverse range of cellular compartments that comprise the tumor microenvironment. A comprehensive approach to tumor interrogation requires efficient tissue dissociation to facilitate analysis at the single-cell level. In contrast to current methods, single-cell analysis of tumor derived cell suspensions by flow cytometry has the potential to provide a more complete understanding of the many subpopulations within the tumor microenvironment and the cell to cell interactions that govern this space.

Here we demonstrate an efficient workflow that enables comprehensive single-cell analysis of solid tumors from breast cancers. Using tumors from clinical samples and mouse models, we evaluated different dissociation and processing techniques for their effects on cellular viability and surface marker expression. Solid tumors were dissociated into single-cell suspensions using a combination of mechanical dissociation and enzymatic digestion. Phenotypic distribution and morphology of cells within the tumor microenvironment was evaluated using flow cytometry. As this approach evolves, and a knowledge base of relevant surface markers is established, this technology has the potential to significantly impact how tumor biopsies are processed to get multiparametric information at a single cell level.

Citation Format: Aaron J. Middlebrook, Shahryar Niknam, Joyce Ruitenberg, Albert J. Mach, Maria Suni, Warren Porter, Friedrich Hahn, Eileen Snowden, Rainer Blaesius, Smita Ghanekar. Characterization of single cells from dissociated solid tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 227. doi:10.1158/1538-7445.AM2015-227
Abstract 2296: An isoform of BARD1, associated with many types of cancer, is a driver of oncogenesis by inducing telomere aberrations in vitro and in vivo
Authors: Pilyugin Maxim , Andre Pierre-Alain , Ratajska Magdalena , Irminger-Finger Irmgard
Published: August 2015

BARD1 has tumor suppressor functions by binding to BRCA1 and to p53 via RING finger and ankyrin repeats, respectively. The BARD1-BRCA1 heterodimer has E3 ligase activity, and the BARD1-p53 interaction promotes apoptosis. The expression of N-terminally truncated RING-less BARD1 isoforms, however, was correlated with poor prognosis in various cancers.

We performed overexpression experiments with various isoforms of BARD1 and found that BARD1δ, lacking RING and ANK regions, induces cell cycle arrest, multipolar mitotic spindles, genomic instability, and telomere aberrations. Co-localization studies and interaction assays in HeLa, MCF7, or HEK 293 cells, using tagged BARD1δ and full length (FL) BARD1, showed that the BRCT domains, present in BARD1δ and FL BARD1, interact with centrosome binding proteins and telomere binding proteins. BARD1δ overexpressing cells showed multipolar spindles and telomere alterations. Similar telomere alterations were observed in cells with reduced expression of FL BARD1 by siRNA. This is consistent with the observed distinct telomeric abnormalities in blood cells of patients with a BARD1 germline mutation that causes translation of a truncated protein lacking the BRCT domains. CRE-inducible BARD1δ transgenic mice showed dose-dependent growth arrest and tumor formation in various organs. These in vitro and in vivo observations suggest that BARD1δ plays a significant role in tumorigenesis by inducing genomic and telomere instability.

Citation Format: Maxim Pilyugin, Pierre-Alain Andre, Magdalena Ratajska, Irmgard Irminger-Finger. An isoform of BARD1, associated with many types of cancer, is a driver of oncogenesis by inducing telomere aberrations in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2296. doi:10.1158/1538-7445.AM2015-2296
Abstract 2299: Generation and characterization of inducible KIF5B-RET mouse model of non-small cell lung cancer
Authors: Huang Qingling , Schneeberger Valentina E. , Luetteke Noreen , Jin Chengliu , Coppola Domenico , Wu Jie
Published: August 2015

The new precision oncology requires identification of driver oncogenes, validation of oncogene addiction, and development of oncogene-targeted drugs. Lung cancer is molecularly heterogeneous characterized by various genetic alterations, many of them occur at low frequencies. Recurrent RET fusion genes have been found in 1-2% of non-small cell lung cancer (NSCLC). Among them KIF5B-RET fusion is the most prevalent and occurs specifically in NSCLC. To develop an in vivo animal model for evaluation of KIF5B-RET fusion in lung adenocarcinoma, we generated transgenic mice containing a doxycycline (Dox)-inducible tetO-KIF5B-RET transgene. To express KIF5B-RET in lung type II epithelial cells, tetO-KIF5B-RET mice were crossed with CCSP-rtTA mice. CCSP-rtT/tetO-KIF5B-RET bitransgenic mice were induced with Dox and lung tissues were analyzed. KIF5B-RET mRNA and protein were detected in the lungs of Dox-induced CCSP-rtTA/tetO-KIF5B-RET bitransgenic mice. Histological examinations showed lung hyperproliferative lesions and tumors in Dox-induced CCSP-rtTA/tetO-KIF5B-RET bitransgenic mice. Thus, KIF5B-RET fusion is a driver oncogene sufficient to induce lung tumors in transgenic mice.

Citation Format: Qingling Huang, Valentina E. Schneeberger, Noreen Luetteke, Chengliu Jin, Domenico Coppola, Jie Wu. Generation and characterization of inducible KIF5B-RET mouse model of non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2299. doi:10.1158/1538-7445.AM2015-2299
Abstract 2302: Analysis of the role of CADM1 in suppression of lung cancer using Cadm1-deficient mice
Authors: Ito Takeshi , Nagata Masayoshi , Kawai Taketo , Sakurai-Yageta Mika , Ito Akihiko , Goto Akiteru , Matsubara Daisuke , Murakami Yoshinori
Published: August 2015

Lung cancer is the leading cause of cancer deaths, and non-small-cell lung cancer (NSCLC) is the most prevalent form of lung cancer. The tumor suppressor gene CADM1/TSLC1 was originally identified in NSCLC. CADM1 encodes an immunoglobulin superfamily cell adhesion molecule. CADM1 is inactivated by deletion and/or promoter methylation of the gene in 40-60% of NSCLC, especially in their advanced stages. Previously we generated conventional Cadm1-deficient mice and found that around 40% of Cadm1-deficient mice spontaneously developed lung adenoma and adenocarcinoma by 15 months of age. To assess the precise role of CADM1 in suppression of lung tumorigenesis, we crossed Cadm1-deficient mice to conditional K-ras-mutant mice, well-established mouse models of lung cancer. The K-ras-mutant mice are shown to develop multiple lung adenocarcinomas by 25 weeks after administration of adenovirus expressing Cre recombinase followed by the activation of oncogenic K-ras. We then analyzed the development of lung tumors in K-ras-mutant (K) mice and K-ras-mutant Cadm1-deficient (KC) mice. Loss of Cadm1 results in enlargement of the size of alveolar tumors (adenomas or adenocarcinomas) as well as higher tumor grades. The most malignant histology of vascular or pleural invasion was only detected in tumors from KC mice. On the other hand, the size of the bronchial tumors was larger in K mice than in KC mice. Immunohistochemical analysis of bronchial marker SOX2 showed that adenomas or adenocarcinomas expressing SOX2 were larger in KC mice, indicating that loss of Cadm1 enhanced the rapid growth of alveolar tumors and thereby impaired the growth of bronchial tumors originated from the common stem cells, bronchio-alveolar stem cells (BASCs). Furthermore, tumors from K mice showed frequent loss of CADM1 expression and the tumors with low expression of CADM1 exhibited more malignant histological features. These results suggest that loss of Cadm1 promotes the malignant progression of alveolar tumor.

Citation Format: Takeshi Ito, Masayoshi Nagata, Taketo Kawai, Mika Sakurai-Yageta, Akihiko Ito, Akiteru Goto, Daisuke Matsubara, Yoshinori Murakami. Analysis of the role of CADM1 in suppression of lung cancer using Cadm1-deficient mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2302. doi:10.1158/1538-7445.AM2015-2302
Abstract 2330: Activation of cancer stem cells by oncogenic K-Ras requires activated Wnt/β-catenin signaling
Authors: Moon Byoung-San , Lee Kug Hwa , Koo Kyounghwa , Choi Kang-Yell
Published: August 2015

Adenomatous polyposis coli (APC) loss-of-function mutations and K-Ras gain-of-function mutations are common abnormalities that occur during the initiation and intermediate adenoma stages of colorectal tumorigenesis, respectively. However, little is known about the role of these mutations in the regulation of cancer stem cells (CSCs) associated with colorectal cancer (CRC) tumorigenesis. We analyzed tissue from CRC patients (n = 49) and observed an association between K-Ras mutations and CSC activation during colorectal tumorigenesis. The oncogenic K-Ras mutations enhanced stemness of CRC cells carrying an APC mutation, as shown by comparisons of sphere formation, transforming potential, and differentiation in vitro and tumor-forming capacity in vivo between isogenic APC mutated CRC cells harboring either wild-type or mutant K-Ras. Moreover, the activation of CSC by K-Ras mutations in CRC required an additional APC mutation, as revealed by the induction of CD44, CD133, and CD166 in intestinal tumor tissues of APCMin/+/K-RasLA2 double-mutant mice, but not in K-RasLA2 mice. Overall, the progression and metastasis of CRC induced by K-Ras mutation occurs by initial activation of CSC by APC loss and further activation of Wnt/β-catenin signaling and subsequent activation of Ras-ERK signaling.

Citation Format: Byoung-San Moon, Kug Hwa Lee, Kyounghwa Koo, Kang-Yell Choi. Activation of cancer stem cells by oncogenic K-Ras requires activated Wnt/β-catenin signaling. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2330. doi:10.1158/1538-7445.AM2015-2330
Abstract 2332: Converging molecular effectors of airway lineage specification and metastasis in lung cancer
Authors: Nguyen Don X.
Published: August 2015

Lung adenocarcinoma (LUAD) is a deadly and heterogeneous subtype of non-small cell lung cancer. During LUAD progression, the emergence of alternate epithelial lineage fates in primary tumors correlates with poor outcome. The underlying mechanisms and biological consequences of these phenomena are poorly understood.

Using an integrated approach, we previously examined the molecular relationship between cell differentiation states, lung cancer subtypes, and clinical outcome, to discover a novel role for several lineage-restricted transcription factors in the pathogenesis of LUAD (1). Specifically, we identified the alveolar specification factor, HOPX, as an inhibitor of metastatic progression. Herein we show that down-regulation of its function in a subset of human tumors correlates with DNA hypermethylation, aberrant tumor differentiation, and relapses. HOPX restricts the metastatic potential of LUAD cells, by modulating converging transcriptional programs of airway epithelial differentiation, malignant invasion, and metabolic adaptation in response to the extracellular microenvironment. Mechanistically, HOPX mediates its functions in part through the regulation of previously uncharacterized long-intergenic long non-coding RNAs with potential roles in lung development.

Our findings demonstrate that perturbation of intrinsic cell lineage pathways is a determinant of metastasis in specific lung cancers. The implications of these findings for the origin(s) and treatment of LUAD metastasis will be further discussed.

(1) Cheung, W.K.C., Zhao, M., Liu, Z., Stevens, L.E., Cao, P.D., Fang, J.E., Westbrook, T.F., and Nguyen, D.X. (2013). Cancer Cell, 23 (6): 725-738.

Citation Format: Don X. Nguyen. Converging molecular effectors of airway lineage specification and metastasis in lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2332. doi:10.1158/1538-7445.AM2015-2332
Abstract 2336: AD1 promotes astroglial differentiation and depletes glioblastoma stem cells
Authors: Spina Raffaella , Voss Dillon M. , Sloan Andrew , Bar Eli E.
Published: August 2015

Glioblastoma are among the least curable cancers in man, at least in part because of stem-like cellular subpopulations (herein referred to as glioma stem cells, GSC) refractory to current therapies. The cancer stem cell hypothesis suggests that tumor cells are organized in a pyramidal unidirectional differentiation cascade with GSC at the top and functionally defined by the ability to self-renew and initiate tumors identical to the original tumors from which they are derived. GSCs are maintained by both cell intrinsic and micro-environmental factors and conditions. In this study we focused on identifying small molecules which target tumor heterogeneity by promoting differentiation of GSC into less aggressive, more differentiated subpopulations. To this end, we have developed reporter models for astroglial and neuronal differentiation in HSR-GBM1, HSR040622 and HSR040821 tumor-derived, GSC-enriched, neurospheres lines, using lineage-specific reporter constructs. We employed these reporter lines to screen a library of over 700 bioactive small molecules for potential inducers of GSC differentiation. We identified several molecules which significantly induce astroglial differentiation in multiple GSC-enriched lines. In this report, we focus on one of these agents, (AD1 = (Astroglial Differentiation-1), which induces astroglial differentiation by up to 30-fold as compared with DMSO control. Interestingly, the effects of AD-1 appear to be primarily cytostatic rather than cytotoxic. As differentiation should result in reduced self-renewal capacity, we next determined the effect of AD1 on clonogenicity in vitro using the extreme limited dilution assay (ELDA). We found that 48h treatment with AD1 significantly reduced clonogenic capacity of HSR-GBM1, HSR-040622 and HSR-040821 reporter lines by over 90%. To test this in vivo we examined the effect of AD1 on tumor initiation in an intracranial transplantation model. We found that ex vivo treatment with AD1 resulted in a significant increase in the survival of animals as 6 (of 6) animals transplanted with DMSO-treated cells exhibited massively infiltrating tumors while 2 (of 6) of the animals implanted with AD1 treated cells developed tumors, and those began to appear several weeks later. Importantly, the effects of AD1 are likely to be irreversible as cells extracted from tumors maintained reporter expression even after six passages in vitro. Taken together, our results support the therapeutic value of a drug-induced differentiation and define how differentiation affects the GSC compartment in glioma.

Citation Format: Raffaella Spina, Dillon M. Voss, Andrew Sloan, Eli E. Bar. AD1 promotes astroglial differentiation and depletes glioblastoma stem cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2336. doi:10.1158/1538-7445.AM2015-2336
Abstract 2346: Targeting the tumor immune response for pro-senescence therapy in prostate cancer
Authors: Di Mitri Diletta , Chen JingJing , Alimonti Andrea
Published: August 2015

Cellular senescence is a stable growth arrest that constrains cell cycle progression in case proliferation becomes aberrant, thus limiting tumorigenesis. Oncogenic mutations and loss of tumor suppressor genes that cause uncontrolled cell-cycle progression are required events in tumor development. Nevertheless, many of these genetic alterations retain an intrinsic tumor-suppressive potential that gives rise to oncogene-induced senescence and tumor suppressor loss-induced senescence. Interestingly, many evidences support the idea that a strong interplay occurs between senescence, cancer cells, and tumor infiltrating immune populations, thus opening at the possibility to tune such interplay for cancer treatment. Indeed, tumor infiltrating T helper 1 cells can drive senescence in cancers in a cytokine-induced manner, by secreting IFNγ and TNFα in the tumor microenvironment. In addition, we recently described a model where Pten loss induced senescence is hindered in prostate tumor by non-cell-autonomous mechanisms. Our study support a model where tumor-infiltrating CD11b+Gr-1+ myeloid cells paracrinally triggers tumor senescence evasion in the prostate of Pten null mice, eventually promoting tumor progression. These findings we’ll be discussed. Interestingly, we will present new evidences from our lab indicating that M1 macrophages are polarized to the M2 phenotype in both Pten pc-/- and that treatments that interfere with the M1-M2 polarization and switch the skewing to the M1 polarization profile can induce senescence in Pten; Trp53pc-/- invasive prostate cancer tumours thereby arresting tumour progression. These findings open at the possibility that M1 directly control senescence in tumor cells. Finally, we have identified a gene expression signature that distinguishes myeloid infiltration in tumors and can be used as a predictive marker for tumor progression in prostate cancer patients. These evidences we’ll be also discussed.

Citation Format: Diletta Di Mitri, JingJing Chen, Andrea Alimonti. Targeting the tumor immune response for pro-senescence therapy in prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2346. doi:10.1158/1538-7445.AM2015-2346
Abstract 2353: Noncanonical NF-κB activation mediates STAT3-stimulated IDO up-regulation in myeloid-derived suppressor cells in breast cancer
Authors: Yu Jinpu , Wang Yue , Li Hui , Ren Xiubao
Published: August 2015

Immunotherapy for cancer treatment is achieved through the activation of competent immune effector cells and the inhibition of immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs). While MDSCs have been shown to contribute to breast cancer development, the mechanism underlying MDSCs-mediated immunosuppression is unclear. We have identified a poorly differentiated MDSC subset in breast cancer suppressing T-cell function through signal transducer and activator of transcription (STAT) 3-dependent indoleamine 2,3 dioxygenase (IDO) up-regulation. Here we investigated the mechanisms underlying aberrant expression of IDO in MDSCs. MDSCs were induced by co-culturing human CD33+ myeloid progenitors with MDA-MB-231 breast cancer cells. Increased STAT3 activation in MDSCs was correlated with activation of the noncanonical nuclear factor-κB (NF-κB) pathway, including increased NF-κB-inducing kinase (NIK) protein level, phosphorylation of cytoplasmic inhibitor of NF-κB kinase (IKK) α and p100, and RelB-p52 nuclear translocation. Blocking STAT3 activation with the small molecule inhibitor JSI-124 significantly inhibited the accumulation of NIK and IDO expression in MDSCs. Knock-down of NIK in MDSCs suppressed IDO expression, but not STAT3 activation. RelB-p52 dimers were found to directly bind to the IDO promoter, leading to IDO expression in MDSCs. IL-6 was found to stimulate STAT3-dependent, NF-κB-mediated IDO up-regulation in MDSCs. Furthermore, significant positive correlation between the numbers of pSTAT3+ MDSCs, IDO+ MDSCs, and NIK+ MDSCs was observed in human breast cancers. These results demonstrate a STAT3-NF-κB-IDO pathway in breast cancer-derived MDSCs, which provides insight into understanding immunosuppressive mechanisms of MDSCs in breast cancer.

Citation Format: Jinpu Yu, Yue Wang, Hui Li, Xiubao Ren. Noncanonical NF-κB activation mediates STAT3-stimulated IDO up-regulation in myeloid-derived suppressor cells in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2353. doi:10.1158/1538-7445.AM2015-2353
Abstract 2359: Adrenergic regulation of MCP-1 leads to enhanced macrophage recruitment and ovarian carcinoma growth
Authors: Armaiz-Pena Guillermo N. , Gonzalez-Villasana Vianey , Nagaraja Archana S. , Rodriguez-Aguayo Cristian , Dorniak Piotr , Previs Rebecca , Sadaoui Nouara , Stone Rebecca , Matsuo Koji , Dalton Heather J. , Lutgendorf Susan K. , Sood Anil K. , Lopez-Berestein Gabriel
Published: August 2015

Increased adrenergic signaling is known to promote tumor progression, but the underlying mechanisms remain poorly understood. Tumor associated macrophages (TAMs) are key components of the tumor microenvironment that contribute to pro-inflammatory processes and tumor growth. Recently, it has been reported that patients with higher levels of adrenergic signaling have higher counts of MMP-9-producing TAMs. Here, we examined factors responsible for stress-mediated effects on monocyte/macrophage recruitment into the tumor microenvironment and the resultant effects on tumor growth. Conditioned media from norepinephrine- or epinephrine-treated ADRB positive SKOV3ip1 ovarian cancer cells had significantly increased levels of pro-inflammatory cytokines, such as MCP1, fractalkine, IL6, IL8 and VEGF. MCP1, a key modulator of monocyte/macrophage recruitment, gene and protein levels were significantly increased in vitro after catecholamine exposure, which was mediated by cAMP and PKA, while this effect was abrogated by a beta-blocker. SKOV3ip1 tumor samples from mice, subjected to daily restraint stress, had elevated MCP1 gene and protein expression levels, increased CD14+ cells, and increased infiltration of CD68+ cells. Both, propranolol, a non-specific beta-blocker, and hMCP1 siRNA packaged in DOPC nanoparticles significantly abrogated daily restraint stress-induced tumor growth and inhibited infiltration of CD68+ and F4/80+ cells. Of patient samples evaluated (n = 462), 28% had elevated absolute peripheral blood monocyte (>0.7 × 106/μL) and 43% had high peripheral blood monocytes when measured as the percent of white blood cell content (>8%). Elevated peripheral blood monocytes and increased CD68+ cells (>15/hpf) in samples from ovarian cancer patients were significantly associated with advanced disease and worse overall survival. In summary, increased adrenergic signaling is associated with enhanced macrophage infiltration mediated by tumor cell-derived MCP1 production.

Citation Format: Guillermo N. Armaiz-Pena, Vianey Gonzalez-Villasana, Archana S. Nagaraja, Cristian Rodriguez-Aguayo, Piotr Dorniak, Rebecca Previs, Nouara Sadaoui, Rebecca Stone, Koji Matsuo, Heather J. Dalton, Susan K. Lutgendorf, Anil K. Sood, Gabriel Lopez-Berestein. Adrenergic regulation of MCP-1 leads to enhanced macrophage recruitment and ovarian carcinoma growth. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2359. doi:10.1158/1538-7445.AM2015-2359
Abstract 2363: Loss of Sparc in p53-null astrocytes alters collagen deposition and promotes macrophage activation and tumor phagocytosis
Authors: Thomas Stacey L. , Schultz Chad R. , Mouzon Ezekiell , Golembieski William A. , Lemke Nancy , Poisson Laila M. , Gutierrez Jorge A. , Cottingham Sandra , Rempel Sandra A.
Published: August 2015

Both the induction of SPARC expression and the loss of the p53 tumor suppressor gene are changes that occur early in glioma development. Therefore, the upregulation of SPARC may cooperate with the loss of p53 to enhance cell survival and inhibit apoptosis during glioma formation. This study determined whether the loss of Sparc in astrocytes that are null for p53 (p53-null/Sparc-null) would result in reduced cell survival and tumor formation and increased tumor immunogenicity in an in vivo xenograft brain tumor model. In vitro, the loss of Sparc in p53-null astrocytes resulted in an increase in cell proliferation (15-33%, p<0.01); however, there was an inhibition of growth in soft agar. Intracranial xenografts of p53-null/Sparc-wt and p53-null/Sparc-null astrocytes were assessed for tumor size, proliferation rate, and SPARC expression. At 7 days post-implantation, Sparc-null astrocytes produced significantly smaller tumors (Wilcoxon rank-sum test p = 0.0091, median = 0.709mm2 for Sparc-wt and 0.240mm2 for Sparc-null) with a significantly lower MIB-1 proliferation index (Wilcoxon rank-sum test p = 0.0345, median = 8.6% for Sparc-wt and 0.4% for Sparc-null). By CD68 and periodic acid Schiff +/- diastase staining of xenograft tumors, it was found that Sparc-null tumors had a massive infiltration of microglia/macrophages with a phagocytic appearance compared to the activated, but non-phagocytic, microglia/macrophages present within the Sparc-wt tumors. The loss of Sparc in astrocytes and the resulting increase in microglia/macrophage activation lead to an alteration in the tumor microenvironment with increased collagen deposition and altered collagen structure at both 7 and 50 days post-implantation as assessed by picrosirius red and polarized light microscopy. Sparc-null tumors had increased collagen deposition with a long fiber structure compared to the small bundles of collagen present in Sparc-wt tumors. Our results indicate that the loss of p53 by deletion/mutation in the early stages of glioma formation may cooperate with the induction of SPARC to potentiate cancer cell survival and escape from immune surveillance.

Citation Format: Stacey L. Thomas, Chad R. Schultz, Ezekiell Mouzon, William A. Golembieski, Nancy Lemke, Laila M. Poisson, Jorge A. Gutierrez, Sandra Cottingham, Sandra A. Rempel. Loss of Sparc in p53-null astrocytes alters collagen deposition and promotes macrophage activation and tumor phagocytosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2363. doi:10.1158/1538-7445.AM2015-2363
Abstract 238: Citrullination of miRNA regulators by PADs: A potential mechanism for the promotion of colitis and colitis-associated colorectal cancer
Authors: Witalison Erin E. , Cui Xiangli , Causey Corey P. , Thompson Paul R. , Hofseth Lorne J.
Published: August 2015

Ulcerative Colitis (UC) is a chronic, relapsing inflammatory bowel disease that affects millions of people worldwide. As a result of DNA damage caused by the chronic inflammatory state of UC, people suffering from UC are at a higher risk of developing colorectal cancer (CRC). Although the cause of UC is still unknown, the protein arginine deiminase (PAD) family of enzymes has been found to be a key component in many human inflammatory diseases and cancer, including UC and CRC. PADs are calcium-dependent enzymes that post-translationally convert positively charged peptidyl-Arginine to neutral peptidyl-Citrulline through a process called ‘citrullination’. In hopes of treating UC and preventing CRC, we developed Chlor-amidine (Cl-amidine), a novel small molecule inhibitor of PADs. Previous results from our group have shown that miR-16, which is often downregulated in cancers, had increased expression levels in mice treated with Cl-amidine. MiR-16 targets (i.e. Cyclin D1 and E1) and colon carcinogenesis were also suppressed in mice treated with Cl-amidine. Our goal is to determine the mechanism(s) by which Cl-amidine targets miR-16 and other tumor suppressor miRNAs. One hypothesis is that Cl-amidine is preventing the citrullination of DNA methyltransferases (DNMTs). Citrullinated DNMTs show hyperactivity, resulting in hypermethylation and subsequent silencing of miRNAs. Evidence suggests that PADs can citrullinate DNMT3A, resulting in ‘methylation-mediated gene silencing’. We predict that this silencing negatively regulates tumor suppressor miRNAs and Cl-amidine treatment will restore these miRNA levels. Initial results suggest citrullination of DNMT3A in our in vitro colon cancer cell line model. Experiments are ongoing to confirm the ability of Cl-amidine to prevent citrullination-induced activation of upstream miRNA regulators. Results from our study will elaborate on the mechanism of action of Cl-amidine and provide further insight into using Cl-amidine as an anti-cancer therapy.

Citation Format: Erin E. Witalison, Xiangli Cui, Corey P. Causey, Paul R. Thompson, Lorne J. Hofseth. Citrullination of miRNA regulators by PADs: A potential mechanism for the promotion of colitis and colitis-associated colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 238. doi:10.1158/1538-7445.AM2015-238