bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5175: Survivin Suppression by YM155 involves downregulation of Cyclin Ds and Activation of Rb.
Authors: Shankar Eswar , Corum Sarah L. , Welford Scott M. , Danielpour David
Published: August 2014

The pro-metastatic and survival protein Survivin is robustly overexpressed in carcinomas compared to normal or benign tissue. The imadazolium based small molecule YM155, which was discovered in a chemical library screen of compounds that effectively suppressed the Survivin promoter, induces apoptosis of castration-resistant prostate cancer (CRPC) cells. Despite the current use of YM155 in phase II clinical trials, the mechanisms by which YM155 inhibits the expression of Survivin and kills cancer cells remain unclear. Our laboratory previously reported that the pocket proteins (Rb, p107, p130) suppress Survivin expression by recruiting E2F4 to CDE/CHR promoter elements of the Survivin promoter. Here we studied early signaling responses in a panel of prostate and kidney cancer cell lines and showed that YM155 rapidly decreases the levels of cyclin Ds and activates Rb, preceding the suppression of Survivin expression. We hypothesize that YM155 down-regulates Survivin expression by activating the pocket proteins and promoting their recruitment along with E2F4 to the proximal region of the Survivin promoter. In addition, we provide evidence that the induction of apoptosis by YM155 may be mediated not only by the downregulation of Survivin but also through induced expression of the proapoptotic protein Bim, repression of the anti-apoptotic protein Mcl-1, followed by activation of caspases.

Citation Format: Eswar Shankar, Sarah L. Corum, Scott M. Welford, David Danielpour. Survivin Suppression by YM155 involves downregulation of Cyclin Ds and Activation of Rb. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5175. doi:10.1158/1538-7445.AM2013-5175
Abstract 518: Kisspeptin stimulates invasiveness of ERα -negative human mammary epithelial and breast cancer cells.
Authors: Bhattacharya Moshmi M. , Cvetkovic Dragana , Dragan Magdalena , Leong Hon Sing , Babwah Andy
Published: August 2014

Recently, we have shown that KP-10 stimulates invasion of estrogen receptor (ERα)-negative breast cancer cells via transactivation of the epidermal growth factor receptor (EGFR) [Zajac et al. (2011) PLoS ONE 6(6): e21599]. Here we report that KP-10 stimulated cell motility and invasiveness of ERα-negative non-malignant mammary epithelial MCF10A cells that endogenously expressing KISS1R, and MCF10A cells stably expressing KISS1R using three-dimensional (3D) Matrigel cultures. Additionally, exogenous expression of KISS1R in ERα-negative SKBR3 breast cancer cells stimulated invasion in 3D cultures and induced extravasation in vivo using chorioallantoic membrane (CAM) assays. Exogenous KISS1R expression in MCF10A and SKBR3 cells also induced a partial epithelial-to-mesenchymal transition like phenotype as evidenced by the acquisition of a spindle-shaped morphology, intracellular localization of the epithelial marker E-cadherin, increased stress fibre formation and elevated levels of the mesenchymal markers, Snail/Slug, vimentin and N-cadherin. In contrast, KP-10 had no effect on migration and invasion of the ERα-positive T47D and MCF7 breast cancer cells and failed to transactivate EGFR in the ERα-positive cells. This suggested that ERα negatively regulates KISS1R-dependent breast cancer cell migration, invasion and EGFR transactivation. In support of this, we found KP-10-stimulated cell migration, invasion and EGFR transactivation were ablated upon stably expressing ERα in the ERα-negative MDA-MB-231 cells. Lastly, we found that KISS1R was localized at the leading edge of motile cells, where it co-localized with the actin scaffolding protein, IQGAP1. We have identified IQGAP1 as a novel binding partner of KISS1R and have demonstrated that KISS1R regulates EGFR transactivation in breast cancer cells in an IQGAP1-dependent manner. Overall, our data strongly suggest that the ERα status of mammary cells will dictate whether the KISS1R signaling pathway may be a novel clinical target for the treatment of breast cancer metastasis.

Citation Format: Moshmi M. Bhattacharya, Dragana Cvetkovic, Magdalena Dragan, Hon Sing Leong, Andy Babwah. Kisspeptin stimulates invasiveness of ERα -negative human mammary epithelial and breast cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 518. doi:10.1158/1538-7445.AM2013-518
Abstract 5180: Activation of NF- KB by Notch4/Int3 is Rbpj-independant.
Authors: Raafat Ahmed M. , Bargo Sharon , Callahan Robert
Published: August 2014

Transgenic mice expressing the Notch 4 intracellular domain (ICD) (Int3) in the mammary gland have two phenotypes exhibited with 100% penetrance: arrest of mammary alveolar/lobular development and mammary tumorigenesis. Notch4 signaling is mediated primarily through the interaction of Int3 with the transcription repressor/activator Rbpj. Interestingly, Rbpj knockout mice (Wap-Cre+/Rbpj-/-/Wap-Int3) have normal mammary gland development also developed mammary tumors with a slightly longer latency than the Wap-Int3 mice. Thus, Notch-induced mammary tumor development is independent of this interaction. Here, we show that Int3 activates NF-κB in HC-11 cells and induces p50 Phosphorylation in absence of Rbpj. Also, Int3 regulates NF-κB in mammary tumors via IKK-mediated pathway. Treatment of Wap-Int3 baring tumors mice with IKK inhibitor resulted in tumors regression. Also, Wap-Int3/p50 knockout mice did not develop mammary tumors. The data indicates that the NF-κB canonical pathway is the Int3-Rbpj independent pathway.

Citation Format: Ahmed M. Raafat, Sharon Bargo, Robert Callahan. Activation of NF- KB by Notch4/Int3 is Rbpj-independant. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5180. doi:10.1158/1538-7445.AM2013-5180
Abstract 5185: RNAi screen identifies a synthetic lethal interaction between Pim1 overexpression and Plk1 inhibition.
Authors: Abdulkadir Sarki , Meer Riet Vander , Roh Meejeon
Published: August 2014

PIM1 kinase is overexpressed in many tumor types including lymphomas and prostate cancer, where it is known to cooperate with the MYC oncogene in promoting tumorigenicity. PIM1 enhances MYC stability and transcriptional activity. Knowledge of the vulnerabilities of Pim1-expressing tumor cells will be of great value in efforts to develop novel anti-cancer therapeutics. Here we have used RNAi screening to identify genes whose depletion is detrimental to Pim1-overexpressing cells. We screened a collection of 570 siRNAs targeting cell cycle, apoptosis, serine-threonine kinase and tyrosine kinase genes for their effects on the viability of Pim1-expressing RWPE1 prostate epithelial cells. We identified the mitotic regulator polo-like kinase (PLK1) as a gene whose depletion is particularly detrimental to the viability of Pim1-expressing prostate cancer cells in vitro and in vivo. Inhibition of PLK1 by shRNA or by the chemical inhibitor BI2536 in prostate cancer xenograft model resulted in a dramatic inhibition of tumor progression in Pim1-overexpressing cells. Interestingly Pim1-overexpressing cells are more prone to mitotic arrest followed by apoptosis. Furthermore, inhibition of Plk1 activity led to the reduction of MYC protein levels both in vitro and in vivo. These results suggest that PLK1 inhibition may be particularly effective against PIM1-expressing tumors due, at least in part, to the fact that PLK1 inhibition reduces MYC protein levels.

Citation Format: Sarki Abdulkadir, Riet Vander Meer, Meejeon Roh. RNAi screen identifies a synthetic lethal interaction between Pim1 overexpression and Plk1 inhibition. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5185. doi:10.1158/1538-7445.AM2013-5185

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 5191: Gab2 phosphorylation by RSK inhibits Shp2 recruitment and cell motility.
Authors: Zhang Xiaocui , Lavoie Geneviève , Fort Loic , Huttlin Edward L. , Tcherkezian Joseph , Galan Jacob A. , Gu Haihua , Gygi Steven P. , Carreno Sebastien , Roux Philippe P.
Published: August 2014

The scaffolding adapter protein Gab2 (Grb2-associated binder) participates in the signaling response evoked by various growth factors and cytokines. Gab2 is overexpressed in several human malignancies, including breast cancer, and was shown to promote mammary epithelial cell migration. The role of Gab2 in the activation of different signaling pathways is well documented, but less is known regarding the feedback mechanisms responsible for its inactivation. We now demonstrate that activation of the Ras/mitogen-activated protein kinase (MAPK) pathway promotes Gab2 phosphorylation on basic consensus motifs. More specifically, we show that RSK (p90 ribosomal S6 kinase) phosphorylates Gab2 on three conserved residues, both in vivo and in vitro. Mutation of these phosphorylation sites does not alter Gab2 binding to Grb2, but instead, we show that Gab2 phosphorylation inhibits the recruitment of the tyrosine phosphatase Shp2 in response to growth factors. Expression of an unphosphorylatable Gab2 mutant in mammary epithelial cells promotes an invasive-like phenotype and increases cell motility. Taken together, these results suggest that RSK is part of a negative feedback loop that restricts Gab2-dependent epithelial cell motility. Based on the widespread role of Gab2 in receptor signaling, these findings also suggest that RSK plays a regulatory function in diverse receptor systems.

Citation Format: Xiaocui Zhang, Geneviève Lavoie, Loic Fort, Edward L. Huttlin, Joseph Tcherkezian, Jacob A. Galan, Haihua Gu, Steven P. Gygi, Sebastien Carreno, Philippe P. Roux. Gab2 phosphorylation by RSK inhibits Shp2 recruitment and cell motility. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5191. doi:10.1158/1538-7445.AM2013-5191
Abstract 5192: MYC amplification and overexpression Is associated With metastasis and drug resistance in a mouse model of anaplastic thyroid carcinoma.
Authors: Russo Marika A. , Di Cristofano Antonio
Published: August 2014

Anaplastic thyroid carcinoma (ATC) is the most aggressive form of thyroid cancer. Despite a relatively low prevalence, it accounts for a disproportionate number of thyroid cancer-related deaths, due to its resistance to every therapeutic approach. We have generated a mouse model in which simultaneous selective activation of the PI3K pathway and inactivation of p53 in thyroid epithelial cells leads to the development of ATC. These tumors display all the typical features of their human counterpart and metastasize to the lungs in over 25% of cases (20 out of 76).

Recent data have indicated that mammary tumors driven by PI3K activation quickly become resistant to PI3K inhibitors through mechanisms that include Myc amplification. We have used our model to test the hypothesis that Myc overexpression and/or amplification might contribute the aggressive features of PI3K-driven ATC.

Analysis of 46 primary tumors developed by [Pten,p53]thyr-/− mice using a high-sensitivity real-time PCR approach demonstrates that the Myc locus is amplified (copy number ≥4) in about 25% of cases. Conversely, none of 20 metastatic follicular thyroid carcinomas developed by Ptenthyr-/− mice displayed Myc amplification. More strikingly, Myc is amplified in almost 50% (7/15) of ATCs with distant metastases, suggesting that Myc amplification confers more aggressive features to PI3K-driven anaplastic tumors, even in the absence of drug mediated selective pressure.

Furthermore, when injected in syngeneic mice, cell lines established from Myc-amplified tumors grow faster than cell lines derived from tumors without Myc amplification. Myc-amplified cell lines are more resistant than Myc-diploid cells to the PI3K inhibitor BKM120, as well as to paclitaxel and doxorubicin treatment, and this increased resistance can be abrogated by shRNA-mediated Myc downregulation.

These data support a model in which Myc cooperates with PI3K activation to induce more aggressive features, including drug resistance and enhanced metastatic behavior, in advanced thyroid carcinomas.

Furthermore, these data lay the basis for new studies aimed at increasing therapeutic efficacy by interfering with Myc and Myc-dependent pathways.

Citation Format: Marika A. Russo, Antonio Di Cristofano. MYC amplification and overexpression Is associated With metastasis and drug resistance in a mouse model of anaplastic thyroid carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5192. doi:10.1158/1538-7445.AM2013-5192
Abstract 5203: Identification of an intrinsic determinant critical for maspin subcellular localization and function.
Authors: Dzinic Sijana H. , Kaplun Alexander , Li Xiaohua , Bernardo Margarida M. , Dean Ivory , Lonardo Fulvio , Sheng Shijie
Published: August 2014

Abstract: Maspin is a novel serine protease inhibitor (serpin) that does not act as a classical serine protease inhibitor. Our lab demonstrated that maspin directly inhibits the serine protease-like enzyme, histone deacetylase 1 (HDAC1), which is a major deacetylase up-regulated in many types of cancers. To our knowledge, maspin is the only endogenous polypeptide inhibitor of HDAC1 identified thus far. Interestingly, the differential regulation of maspin during tumor progression is characterized by changes in overall expression and subcellular distribution. In particular, a significant shift in maspin subcellular localization from the nucleus to the cytosol has been observed at the transition from benign epithelial cells to precancerous or low grade carcinoma cells. Accumulated clinical evidence suggests that nuclear retention of maspin is correlated with better overall patient survival. We propose that hypothesized that the configuration and conformation of maspin coded by its primary sequence, i.e. cis elements are the key determinants for where maspin may be retained in a given molecular context. We noted that at the C-terminal end of the RCL sequence is an Aspartate 346 (D346) which is also unique among all maspin homologs and orthologs. In the current study, using the mutagenesis approach, we aimed to determine whether D346 acts as the cis element essential for maspin subcellular localization and function. We showed that in comparison to the maspinWT, which is distributed in both cytosol and nuclei of cancer cells, maspinD346E is predominantly localized in the nuclei of cancer cells. In addition, maspinD346E had an increased affinity towards HDAC1 and it was more effective inhibitor of HDAC1 as compared to the maspinWT. These findings led to a novel molecular model that explains how maspin may be disregulated during tumor progression resulting in loss of its tumor suppressive potential.

Citation Format: Sijana H. Dzinic, Alexander Kaplun, Xiaohua Li, Margarida M. Bernardo, Ivory Dean, Fulvio Lonardo, Shijie Sheng. Identification of an intrinsic determinant critical for maspin subcellular localization and function. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5203. doi:10.1158/1538-7445.AM2013-5203
Abstract 5238: Acquired therapeutic resistance is mediated by deregulation of multiple pathways.
Authors: Heiser Laura M. , Shaw Chad A. , Wang Nicholas J. , Grasso Catie , Anur Pavana , Ng Sam , Goldstein Theodore , Spellman Paul T. , Stuart Joshua , Osborne Kent , Gray Joe , Schiff Rachel
Published: August 2014

The HER2-directed antibody, trastuzumab combined with chemotherapy, has markedly improved outcome of patients with HER2-amplified breast cancer, yet both de novo and acquired resistance occur in a substantial subset of patients. To study the molecular underpinnings of acquired resistance, we have developed a panel of 30 unique HER2+ cell lines that have been cultured to become resistant to lapatinib, trastuzumab and the combination treatment. Each of these models underwent next-generation sequencing to elucidate mechanisms of resistance to HER2 therapies. We hypothesized that resistance may be mediated by modulation of particular pathways - rather than by individual genes. With this idea in mind, we performed a PARADIGM pathway analysis that integrates information from multiple genomic data types to calculate pathway activity scores. The PARADIGM SuperPathways represent 1321 cell signaling pathways curated from sources such as KEGG, BioCarta, and Reactome. We populated the networks with the copy number (ExomeSeq) and expression (RNAseq) datasets that had been normalized to identify contrasts between parental and resistant lines. For each pathway, we computed a Pathway Activity Score as the sum of the absolute value of each node in the pathway, normalized by the total number of pathway nodes. Nearly 30% of the curated pathways (361/1321) are strongly deregulated in at least one of the network models, whereas a much smaller subset (3%) were strongly deregulated across multiple resistance cell line models. Frequently deregulated pathways include hemoglobin chaperone, ATM mediated phosphorylation of repair proteins, the HIF2alpha transcription factor network and the PLK signaling events in the cell cycle. All together, these findings indicate that resistance is mediated through many signaling mechanisms. Furthermore, the acquired resistance-related aberrations suggest possible second-line treatment strategies that may be effective.

Citation Format: Laura M. Heiser, Chad A. Shaw, Nicholas J. Wang, Catie Grasso, Pavana Anur, Sam Ng, Theodore Goldstein, Paul T. Spellman, Joshua Stuart, Kent Osborne, Joe Gray, Rachel Schiff. Acquired therapeutic resistance is mediated by deregulation of multiple pathways. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5238. doi:10.1158/1538-7445.AM2013-5238
Abstract 5251: Role of mammalian Hippo Mst1/2 protein kinase signaling in lung cancer progression.
Authors: Cinar Bekir , Alptekin Almet , Natale Ronald B.
Published: August 2014

Lung cancer is the leading cause of cancer deaths worldwide. Non-small cell lung cancer (NSCLC) is a major lung adenocarcinoma observed in humans. Therapeutic options for patients with NSCLC are very limited and palliative since the disease mechanism is poorly understood. The Mst1/2 serine-threonine kinase, related to hippo (hpo) in drosophila, has emerged as an important regulator of tumorigenesis with poorer prognosis. However, the biological significance of Mst/Hippo in lung cancer pathogenesis remains to be determined. In this study, we assessed Mst1/2 expression at protein levels by western blots in cultures and in primary and metastatic lung cancer tissues by immunohistochemistry, and investigated the potential functional link between EGFR and Mst/Hippo signaling in well-characterized NSCLC cell models in vitro. We found that Mst1/2 protein levels were reduced by at least 50% in two out of five lung tumor cell lines analyzed. Surprisingly, reduction was observed in Erlotinib resistant H1734 and H1975 lung tumor cells. In agreement with this observation, Mst1 protein declined in primary lung tumor and was undetectable in metastatic lung cancer compared to non-cancerous counterparts. In addition, we showed that enforced Mst1 expression significantly increased sensitivity to EGFR inhibition by Erlotinib compared to mock treatment. We also showed that the activation of EGFR by epidermal growth factor (EGF) attenuated the Mst1 mediation of cell growth suppression. Taken together, our findings suggest that the loss of Mst/Hippo functions could contribute to lung tumor progression and acquired resistance to EGFR inhibitor. A molecular understanding of how these two opposing signals biochemically and functionally intersect may improve current EGFR blockade therapy.

Citation Format: Bekir Cinar, Almet Alptekin, Ronald B. Natale. Role of mammalian Hippo Mst1/2 protein kinase signaling in lung cancer progression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5251. doi:10.1158/1538-7445.AM2013-5251
Abstract 5253: SOX2-mediated cell survival and chemoresistance in lung cancer.
Authors: Chou Yu-Ting , Lee Chih-Chan , Hsiao Shih-Hsin , Lin Sey-En , Lin Sheng-Chieh , Wang Yuan-Hung , Wu Cheng-Wen
Published: August 2014

Tumor cells have long been observed to share several biological characteristics with normal stem/progenitor cells; however, the oncogenic mechanisms underlying the stemness features remain elusive. Here we report the involvement of BCL2L1 in SOX2-mediated cell survival and chemoresistance in lung cancer. SOX2 was associated with poor prognosis in lung cancer patients and was expressed in a subclass of lung cancer cells the survival and chemoresistance of which were dependent on SOX2 stem cell signaling. SOX2 promoted chemoresistance, and silencing of SOX2 perturbed mitochondrial function, causing marked apoptosis and autophagy. Moreover, SOX2 knockdown attenuated tumor growth in a xenograft mouse model. SOX2 induced BCL2L1 expression, the ectopic expression of which rescued the effects of SOX2 silencing on apoptosis, autophagy, and mitochondrial function. SOX2 and BCL2L1 expression levels were significantly correlated in human lung tumors, supporting the involvement of BCL2L1 in SOX2-mediated oncogenesis. Our findings reveal for the first time that SOX2-BCL2L1 signaling maintains mitochondrial integrity and enhances cell survival, leading to increased chemoresistance in lung cancer cells.

Citation Format: Yu-Ting Chou, Chih-Chan Lee, Shih-Hsin Hsiao, Sey-En Lin, Sheng-Chieh Lin, Yuan-Hung Wang, Cheng-Wen Wu. SOX2-mediated cell survival and chemoresistance in lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5253. doi:10.1158/1538-7445.AM2013-5253
Abstract 5266: Stat3 is a positive regulator of gap junctional intercellular communication in cultured, human lung carcinoma cells.
Authors: Geletu Mulu , Arulanandam Rozanne , Greer Samantha , Trotman-Grant Aaron , Tomai Evangelia , Raptis Leda
Published: August 2014

Neoplastic transformation of cultured cells by a number of oncogenes such as src suppresses gap junctional, intercellular communication (GJIC); however, the role of Src and its effector Signal transducer and activator of transcription-3 (Stat3) upon GJIC in non small cell lung cancer (NSCLC) has not been defined. Immunohistochemical analysis revealed high Src activity in NSCLC biopsy samples compared to normal tissues. Here we explored the potential effect of Src and Stat3 upon GJIC, by assessing the levels of tyr418-phosphorylated Src and tyr705-phosphorylated Stat3, respectively, in a panel of NSCLC cell lines. Gap junctional communication was examined by electroporating the fluorescent dye Lucifer yellow into cells grown on a transparent electrode, followed by observation of the migration of the dye to the adjacent, non-electroporated cells under fluorescence illumination.

The results demonstrated an inverse relationship between Src activity levels and GJIC; in five lines with high Src activity GJIC was absent, while two lines with extensive GJIC (QU-DB and SK-LuCi6) had low Src levels, similar to a non-transformed, immortalised lung epithelial cell line. Interestingly, examination of the mechanism indicated that Stat3 inhibition in any of the NSCLC lines expressing high endogenous Src activity levels, or in cells where Src was exogenously transduced, did not restore GJIC. On the contrary, Stat3 downregulation in immortalised lung epithelial cells or in the NSCLC lines displaying extensive GJIC actually suppressed junctional permeability. Moreover, expression of the constitutively active form of Stat3, Stat3C caused an increase in gap junctional communication.

Our findings demonstrate that although Stat3 is generally growth promoting and in an activated form it can act as an oncogene, it is actually required for gap junctional communication both in nontransformed lung epithelial cells and in certain lung cancer lines that retain extensive GJIC.

Citation Format: Mulu Geletu, Rozanne Arulanandam, Samantha Greer, Aaron Trotman-Grant, Evangelia Tomai, Leda Raptis. Stat3 is a positive regulator of gap junctional intercellular communication in cultured, human lung carcinoma cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5266. doi:10.1158/1538-7445.AM2013-5266
Abstract 5269: Divergent roles of Akt isoforms in insulin-like growth factor-mediated lung tumorigenesis.
Authors: Franks Sarah Elizabeth , Moorehead Roger A.
Published: August 2014

Lung cancer is the leading cause of cancer related mortalities worldwide. Akt is an important kinase in the PI3K pathway of growth factor signaling, and increased Akt activation in lung cancer is associated with poor prognosis. Akt regulates cell growth, proliferation, survival, metabolism and migration making it an attractive target for molecular therapies. Akt exists as three isoforms (Akt1-3) and while it was previously thought they were largely redundant in activity, evidence of differing roles is emerging. Our lab has generated a doxycycline-inducible, tissue-specific transgenic mouse model of lung cancer. Using a surfactant protein C (SPC) promoter, the type I insulin-like growth factor receptor (IGF-IR) is overexpressed in type II alveolar cells which initiates the development of tumors in the lungs. Following nine months of treatment with doxycycline, macroscopic tumors are present on 100% of transgenic mice. These lung adenomas typically present as one or more discrete nodules on the surface of the lung. In this model, cells expressing high levels of IGF-IR also had higher levels of activated Akt. To investigate the role of specific Akt isoforms in lung tumorigenesis, these SPC-IGFIR transgenic mice were crossed with Akt1 null or Akt2 null mice to generate SPC-IGFIR-Akt1-/- and SPC-IGFIR-Akt2-/- mice. The Akt1 null SPC-IGFIR mice have reduced tumor burden compared to their Akt wild-type counterparts. In contrast, the absence of Akt2 accelerates tumor growth in SPC-IGFIR mice. Tumors formed in Akt1 null mice maintain the phenotype of distinct nodules. However, in the advanced tumor progression seen in Akt2 null mice the tumor tissue appears to permeate the lungs rather than form large nodules. These tumors are currently being characterized through evaluation of intracellular signaling as well as rates of proliferation and apoptosis. Initial results indicate opposing roles of Akt1 and Akt2 in the development and progression of lung cancer. While pan-Akt inhibitors are currently in clinical trials, our data suggests targeting Akt1 may be a more effective therapeutic strategy for lung cancer. However, further understanding of the function of each Akt isoform in lung cancer is needed.

Citation Format: Sarah Elizabeth Franks, Roger A. Moorehead. Divergent roles of Akt isoforms in insulin-like growth factor-mediated lung tumorigenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5269. doi:10.1158/1538-7445.AM2013-5269
Abstract 5270: The role of EphA2 in the maintenance of cell viability of KRAS mutant non-small cell lung cancer.
Authors: Amato Katherine R. , Chen Jin
Published: August 2014

Lung cancer is the leading cause of cancer-related deaths in the United States. Non-small cell lung cancer (NSCLC) is the most common histological subtype of lung cancer, which can be further subdivided based on its unique profile of oncogenic mutations. Identifying molecular subtypes of NSCLC and matching patients with appropriate targeted therapies is critically important for the treatment of this disease. Although significant progress has been made to develop novel, molecularly-targeted therapeutics, challenges still remain in targeting commonly occurring mutations in NSCLC, such as those in KRAS. Overcoming these challenges will require astute strategies to identify and inhibit novel kinase targets required for cell viability in these subtypes of lung cancer. To this end, we have shown that the EphA2 receptor tyrosine kinase plays a unique role in the maintenance of cell viability in NSCLC, especially those with KRAS mutations. EphA2 is generally overexpressed in NSCLC and even further overexpressed in KRAS mutant NSCLC. Preliminary data from our lab has shown that knockdown of EphA2 expression in a large number of human NSCLC cell lines dramatically inhibits cell viability in cell lines bearing KRAS mutations. To further understand this phenotype, we are working to define the molecular mechanisms downstream of EphA2 that are critical for cell viability in this genotype and to model the effects EphA2 deficiency in vivo using transgenic mouse models. Based on our preliminary data, we propose that EphA2 provides a novel target for modulating cell viability in lung cancers with KRAS mutations associated with limited therapeutic options.

Citation Format: Katherine R. Amato, Jin Chen. The role of EphA2 in the maintenance of cell viability of KRAS mutant non-small cell lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5270. doi:10.1158/1538-7445.AM2013-5270
Abstract 5281: Insulin-mediated regulation of the miR132/212 cluster and miR 122/181a expression through PI3K, Akt, mTOR signaling in primary cultured rat hepatocytes.
Authors: Shukla Upasana , Tumma Nithin , Gratsch Theresa , Dombkowski Alan , Novak Raymond
Published: August 2014

Background and Objective: Several microRNAs were selected for characterization of their response to insulin signaling based on previous reports implicating their role in the regulation of hepatic metabolism, diabetes, hepatocellular carcinoma, and predictions of targeting CYP2E1. CYP2E1 catalyzes the metabolic activation of carcinogens, increases cellular oxidative stress, and is elevated in diabetes and at low insulin levels (0.1nM) in primary cultured hepatocytes. In addition, aberrant miR-122 expression was reported to be associated with hepatocellular carcinoma in rats, as well as in human tissue, and may be involved with hepatocarcinogenesis. In view of the critical role of the PI3K, Akt and mTOR signaling pathway in pathogenesis, mechanistic studies were conducted to examine the role of this pathway in regulation miR 132/212, 122 and 181a expression. Methods: Insulin effects on miRNA (miRs) levels were monitored using qPCR, and mechanistic studies employing inhibitors of PI3K, Akt, and mTOR were used to examine the role of this insulin signaling pathway on miR expression. The results were compared to miR let-7a, which is not implicated in the regulation of hepatic metabolism or diabetes and does not target CYP2E1 mRNA. Results: Insulin at concentrations of 0.1, 1.0, and 10 nM increased the expression of miRNA-132 and 212 ∼2- and 1.8-fold respectively, whereas expression of miRNAs 181a and 122 increased ∼1.6- and 1.4-fold, respectively. In contrast, insulin failed to significantly alter the expression of miRNA let-7a. Inhibition of PI3K with LY294002, Akt with A-443654 and mTOR with rapamycin resulted in significant suppression of the insulin-mediated elevation of miR-132, miR-212, and miR-122 levels monitored over the insulin concentrations examined. Inhibition of PI3K with LY294002, or Akt with A-443654 decreased the insulin-mediated increase in miR-181a levels by ∼20 to 50% relative to the respective insulin-concentration. Rapamycin inhibition of mTOR produced a marginal (<10%) decrease in miR-181a levels. Inhibition of PI3K or Akt did not show any significant effect on miR let-7a. In summary, seminal evidence is provided for insulin regulation of microRNA expression in primary cultured hepatocytes through PI3K, Akt and mTOR (TORC1).

Citation Format: Upasana Shukla, Nithin Tumma, Theresa Gratsch, Alan Dombkowski, Raymond Novak. Insulin-mediated regulation of the miR132/212 cluster and miR 122/181a expression through PI3K, Akt, mTOR signaling in primary cultured rat hepatocytes. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5281. doi:10.1158/1538-7445.AM2013-5281
Abstract 5284: A microRNA downregulated in human cholangiocarcinoma induces G2/M arrest through multiple targets.
Authors: Yamanaka Sumitaka , Campbell Nathaniel R. , Kuo Scot C. , Mezey Esteban , Maitra Anirban , Selaru Florin
Published: August 2014

Background: Cholangiocarcinomas (CCA) are cancers with dismal prognosis, thought to arise from epithelial cells lining the biliary tree. An improved understanding of the pathogenesis of CCA, as well as novel diagnostic and therapeutic approaches are direly needed. MicroRNAs (miRs) are short, single-stranded sequences of RNA, that were recently demonstrated to play a major role in the regulation of virtually all cellular processes. Several previous studies identified miRs that are dysregulated in CCA as well as distinct roles played by miRs in CCA genesis or progression. Methods: We performed microRNA-arrays on 5 normal biliary duct epithelias and 5 CCAs that had been obtained at surgery. After data analysis, we selected mir-494 for all subsequent analysis among top 5 miRs. To confirm the initial miR array data, quantitative real time RT-PCR analysis was performed using 12 human CCA as well as 5 normal cholangiocyte specimens. And then, we transfected 2 CCA cell lines with miR-494 and a non-specific mimic, respectively, and performed mRNA arrays to identify in an unbiased fashion the genes whose expression is downregulated by miR-494. Furthermore, we performed fluorescence activated cell sorting, as well as differential interference contrast microscopy.

Results: miR-494 is significantly downregulated in human CCA specimens. Cells transfected with miR-494 showed a significant decrease in growth in the cell proliferation assay. As for the results of mRNA array, Ingenuity Pathway Analysis also indicated that miR-494 appears to coordinately affect several genes involved in the Mitotic Roles of Polo-like Kinase and Cell cycle: G2/M Checkpoint Regulation canonical pathways. We verified that miR-494 modulates the protein level of six genes involved in the G2/M transition. Next, we identified direct binding of miR-494 to the open reading frame (ORF), and downregulation of PTTG1 and TOP2A. Conclusions: our findings suggest that miR-494 has a global regulatory role in cell cycle progression. Therefore, it appears that the simultaneous effects of a single miR species on multiple targets along the same canonical pathway is advantageous for the usage of miRs as therapeutics.

Citation Format: Sumitaka Yamanaka, Nathaniel R. Campbell, Scot C. Kuo, Esteban Mezey, Anirban Maitra, Florin Selaru. A microRNA downregulated in human cholangiocarcinoma induces G2/M arrest through multiple targets. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5284. doi:10.1158/1538-7445.AM2013-5284
Abstract 5288: Identification of critical microRNA regulated pathways in histiocytic diseases.
Authors: Gregory-Bryson Emmalena , Parys Maciej , Kiupel Matti , Yuzbasiyan-Gurkan Vilma
Published: August 2014

Histiocytic diseases encompass a spectrum of proliferative diseases in humans and dogs. While relatively rare in the human, histiocytic diseases are quite prevalent in certain breeds of dog. In the dog, these diseases range from benign histiocytoma to the malignancy, histiocytic sarcoma (HS). Disseminated HS has a poor prognosis and lacks effective treatment options. The goal of this study is to unravel the mechanisms of tumorigenesis in histiocytic diseases by analyzing the differential expression of microRNAs (miRNAs) along the spectrum of canine histiocytic diseases. As regulators of gene expression, miRNAs will provide insight into the pathways for tumorigenesis in histiocytic malignancies as compared to benign histiocytic diseases. MiRNA profiling of canine histiocytic diseases was conducted on cases of reactive histiocytosis, histiocytic sarcoma, and hemophagocytic histiocytic sarcoma. These samples were compared to normal canine histiocytes derived from peripheral blood. Based upon analysis of the profiling data, several miRNAs were selected for verification and quantification by quantitative reverse transcription PCR. The expression of the known canine miRNAs was evaluated by miRNA array. Data analysis with unsupervised clustering resulted in miRNA expression pattern clusters that were similar to the disease groups. The miRNA profiling data revealed three miRNA targets that were significantly upregulated in all cases as compared to normal canine histiocytes. Functional studies of these miRNAs are underway. These findings support the hypothesis that each histiocytic disease entity has a unique miRNA profile. These miRNAs and/or genes in the pathways they regulate may be targeted for novel and effective therapies. Comparative studies have the potential to elucidate HS tumorigenesis, and improve clinical outcome in dogs and humans.

Citation Format: Emmalena Gregory-Bryson, Maciej Parys, Matti Kiupel, Vilma Yuzbasiyan-Gurkan. Identification of critical microRNA regulated pathways in histiocytic diseases. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5288. doi:10.1158/1538-7445.AM2013-5288
Abstract 5292: MicroRNA signatures predictive of response to chemotherapy in mCRC.
Authors: Molina-Pinelo Sonia , Carnero Amancio , Rivera Fernando , Estevez-Garcia Purificacion , Bozada Jose M. , Limon Maria L. , Gomez Javier , Pastor Maria D. , Suarez Rocio , Paz-Ares Luis G. , de la Portilla Fernando , Carranza Andres , Sevilla Isabel , Vicioso Luis , Garcia Carbonero Rocio
Published: August 2014

MicroRNAs (miRNAs) are post-transcriptional regulators involved in numerous biological and pathological processes including colorectal cancer (CRC). From a clinical perspective, several studies have identified groups of miRNAs with potential utility for early diagnosis or prognostic stratification of CRC patients. However, very few have evaluated the potential ability of miRNA to predict response to selected chemotherapy regimens. The aim of our study was to evaluate the ability of miRNA expression patterns to predict chemotherapy response in a cohort of 78 patients with metastatic CRC (mCRC). We examined tumor expression levels of 667 miRNAs in the training cohort by TaqMan Low Density Arrays (TLDA). In training cohort (N=39), we identified a miRNA molecular signature with significant association in relevant clinical endpoints (objective response, progression-free and overall survival). In validation cohort (N=39), we validated significantly higher expression levels of miR-107, and miR99a* according to objective response to fluoropyrimidine-based regimens. These results support a substantial role for miRNAs in determining drug response, and highlight their potential value as biomarkers for personalized treatment strategies and as a novel class of therapeutic targets.

Citation Format: Sonia Molina-Pinelo, Amancio Carnero, Fernando Rivera, Purificacion Estevez-Garcia, Jose M. Bozada, Maria L. Limon, Javier Gomez, Maria D. Pastor, Rocio Suarez, Luis G. Paz-Ares, Fernando de la Portilla, Andres Carranza, Isabel Sevilla, Luis Vicioso, Rocio Garcia Carbonero. MicroRNA signatures predictive of response to chemotherapy in mCRC. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5292. doi:10.1158/1538-7445.AM2013-5292
Abstract 5294: The difference of serum RNA profile: RNA extraction and detection method.
Authors: Takizawa Satoko , Akiyama Hideo , Kondo Satoshi , Kosaka Nobuyoshi , Ochiya Takahiro
Published: August 2014

Serum miRNA profiles are widely reported by many .research groups, but they do not always coincide well. The reason of this difference is suggested to be, at least in some cases, due to a difference in the RNA extraction or detection method. In this report, we compare the miRNA expression profiles of RNAs extracted from (1) extracellular vesicles precipitated by ultra-centrifuging (2) precipitation of ExoQuick (3) whole serum by QIAGEN miRNeasy (4) whole serum by Toray "3D-Gene" RNA extraction reagent from liquid sample kit.

In addition to this, the comparison of data obtained by different detection tools will be also shown. In these days, the whole miRNA expression profiling can be done by multiple qRT-PCR, microarrays, and Next Generation Sequencing. However, the feature of each method will reflect to the obtained data and it is no surprise that data obtained by different tools do not match perfectly. We will compare the serum miRNA expression profiles detected by (1) “TaqMan” Array MicroRNA Card (2) QIAGEN miScript miRNA PCR Array (3) “3D-Gene” Human miRNA oligo chip, and discuss the base of method for serum miRNA profiling.

Citation Format: Satoko Takizawa, Hideo Akiyama, Satoshi Kondo, Nobuyoshi Kosaka, Takahiro Ochiya. The difference of serum RNA profile: RNA extraction and detection method. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5294. doi:10.1158/1538-7445.AM2013-5294
Abstract 5305: Transcriptionalregulation by microRNAs in NSCLC.
Authors: Molina-Pinelo Sonia , Gutierrez-Pozo Gabriel , Pastor Maria D. , Hergueta Marta , Moreno-Bueno Gema , Garcia-Carbonero Rocio , Nogal Ana BS , Suarez Rocio , Salinas Ana , Pozo-Rodríguez Francisco , Lopez-Rios Fernando , Agulló-Ortuño Teresa , Palacios Jose , Carnero Amancio , Paz-Ares Luis G.
Published: August 2014

Squamous cell lung cancer and adenocarcinoma are the most common subtypes of the lung tumours.

The search for cancer-directed treatments has increased the need for understanding molecular features of either histological subtypes. The aim of this study was to identify the transcriptional regulation differences due to miRNA expression profiles between SCC and adenocarcinoma. In this work, a total of 44 patients were evaluated to assess the correlation between the miRNA and messenger

RNA expression levels. We detected changes in 56 mRNAs as well as in 9 miRNAs between SCC and adenocarcinoma. Nearly 20% of overall deregulated genes were targeted by at least one of the 9 miRNAs (miR-149, miR-205, miR-375, miR-378, miR-422a, miR-483-5p, miR-494, miR-601 and miR-708) differentially expressed between SCC and adenocarcinoma (table 1). Genes predicted (CEACAM6, CGN, CLDN3, ABCC3, MLPH, ACSL5,

TMEM45B, MUC1) to be targeted by several miRNAs were individually validated by qRT-PCR. We found genes involved in tight junctions and others involved in resistance to anticancer agents. These genes were reliable biomarkers to detect differences between the two most common histological subtypes of lung cancer. Therefore, transcriptional regulation differences through miRNA expression play an important role in key hallmarks of non-small cell lung cancer.

Citation Format: Sonia Molina-Pinelo, Gabriel Gutierrez-Pozo, Maria D. Pastor, Marta Hergueta, Gema Moreno-Bueno, Rocio Garcia-Carbonero, Ana BS Nogal, Rocio Suarez, Ana Salinas, Francisco Pozo-Rodríguez, Fernando Lopez-Rios, Teresa Agulló-Ortuño, Jose Palacios, Amancio Carnero, Luis G. Paz-Ares. Transcriptionalregulation by microRNAs in NSCLC. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5305. doi:10.1158/1538-7445.AM2013-5305
Abstract 5311: The tumorigenic fusion FGFR3-TACC3 escapes miR-99a regulation in glioblastoma .
Authors: Zhang Wei , Parker Brittany C. , Annala Matti J. , Cogdell David , Granberg Kirsi , Sun Yan , Ji Ping , Li Xia , Gumin Joy , Zheng Hong , Hu Limei , Sawaya Raymond , Fuller Gregory , Chen Kexin , Lang Frederick L. , Nykter Matti
Published: August 2014

Fusion genes are common chromosomal aberrations in many cancers, and can be used as prognostic markers and drug targets in clinical practice. We used whole transcriptome sequencing to search for fusion genes in glioma and discovered FGFR3-TACC3 fusions in 4 / 48 glioblastoma but not in any of 43 low- grade glioma samples. The fusion, caused by tandem duplication on 4p16.3, was found in patients of both Caucasian and Asian origin, and was mutually exclusive with EGFR/PDGFR/MET amplification. The 3’-untranslated region (3’-UTR) of FGFR3 is lost in the fusion, and we show that this leads to elevated fusion gene expression through loss of miR-99a regulation. The fusion protein promoted cell proliferation in vitro and tumor progression in vivo, while WT FGFR3 was not tumorigenic even under forced overexpression.

Citation Format: Wei Zhang, Brittany C. Parker, Matti J. Annala, David Cogdell, Kirsi Granberg, Yan Sun, Ping Ji, Xia Li, Joy Gumin, Hong Zheng, Limei Hu, Raymond Sawaya, Gregory Fuller, Kexin Chen, Frederick L. Lang, Matti Nykter. The tumorigenic fusion FGFR3-TACC3 escapes miR-99a regulation in glioblastoma . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5311. doi:10.1158/1538-7445.AM2013-5311