bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-133: A novel tumor suppressor role for sirt1 inhibiting mitophagy in prostate mouse tissue.
Authors: Sante Gabriele Di , Wang Liping , Wang Chenguang , Bisetto Sara , Casimiro Mathew C , Powell Michael , McBurney Michael , Pestell Richard
Published: August 2014

Introduction. Sirtuin family consists of NAD+-dependent class III histone deacetylases (HDACs). Sirtuin family members (SIRT1-SIRT7) were shown to regulate a variety of physiopathological process, including aging, cellular proliferation, metabolism, and autophagy. Prior studies report SIRT1 as either an oncogene or a tumor suppressor depending upon the cell type and system. However, a reduced expression of SIRT1 in prostate cancer has been reported, supporting the view of SIRT1 as a tumor suppressor. Deregulated intracellular reactive oxygen species (ROS) production induces oxidative stress and damage of nucleic acids, proteins and lipids and may contribute to tumorigenesis. Herein, we provide in vivo support for SIRT1 as a tumor suppressor in prostate cancer. The mechanism appears to involve SIRT1-mediated inhibition of A) mitochondrial ROS production and B) mitophagy.

Materials and methods. 7 month old Sirt1 transgenic mice were used. To investigate the molecular mechanisms through which SIRT1 regulate mitochondrial ROS production and mitophagy process, 3T3 cells wild type (Sirt1+/+) and SIRT1 knockout (Sirt1-/-) were used.

Results. Our clinical and experimental data show a decrease in both SIRT1 expression associated with reduced patient survival probability. A histological evaluation of the H&E performed on both Sirt1+/+ and Sirt1-/- mouse prostate tissues demonstrates that there is a focal atypical intraductal proliferation in prostatic glands of the Sirt1-/- mice, compatible with high grade prostatic intraductal neoplasia (HGPIN). The IHC and relative quantitation of the mouse prostate tissues with Ki67 and AMACR, which are a proliferative and PIN marker respectively, showed an increase of both markers in Sirt1-/- mouse prostate tissue. Preliminary data generated from Sirt1+/+ and Sirt1-/- 3T3 cells suggest that SIRT has a key role in maintaining the mitochondrial healthy status regulating ROS. Sirt1-/- cells undergo a higher oxidative stress, which can lead to cellular damage. We also found mitophagy markers; Beclin1, Bnip3l and LC3 to be overexpressed in Sirt1-/- mouse prostate tissues.

Conclusion and future prospects. These studies suggest SIRT1 inhibits PIN in vivo. The molecular mechanism through which SIRT1 works in a tumor suppressor way is still unknown. We propose a loss of SIRT1 expression may alter the oxidative environment, thereby promoting PIN.

Citation Format: Gabriele Di Sante, Liping Wang, Chenguang Wang, Sara Bisetto, Mathew C Casimiro, Michael Powell, Michael McBurney, Richard Pestell. A novel tumor suppressor role for sirt1 inhibiting mitophagy in prostate mouse tissue. [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 LB-133. doi:10.1158/1538-7445.AM2013-LB-133
Abstract LB-134: mTORC2 regulates the amount of cell surface receptors via its role in protein processing.
Authors: Navia Aixa , Wu Chang-chih , Oh Wonjun , Po-Chien Chou , DeStefano Michael A. , Werlen Guy , Jacinto Estela
Published: August 2014

Signals from cell surface receptors can become altered in cancer due to increased receptor levels. Little is known on how abnormal protein production and quality control may contribute to receptor amplification and tumorigenesis. The mammalian target of rapamycin (mTOR) complex 2 (mTORC2) associates with translating ribosomes and is involved in protein processing. Association of mTORC2 with ribosomes is increased in tumor cells with enhanced PI3K signaling. We found that inhibition of mTORC2 decreases the expression of ErbB1 and CD147 in breast cancer cells. Whereas upregulation of ErbB1 (EGFR1) expression and/or signaling is associated with increased proliferation in breast cancer, CD147 (basigin; EMMPRIN) is linked to tumor metastasis. In mTORC2-disrupted cells, ErbB1 and CD147 have defective expression and processing. Glucose-starved breast cancer cells undergo misprocessing of CD147 along with a decreased expression of mature receptors. Our findings suggest that mTORC2 plays a role in receptor processing and could therefore control cell proliferation via regulation of the amount of growth factor receptors in the cell surface.

Citation Format: Aixa Navia, Chang-chih Wu, Wonjun Oh, Chou Po-Chien, Michael A. DeStefano, Guy Werlen, Estela Jacinto. mTORC2 regulates the amount of cell surface receptors via its role in protein processing. [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 LB-134. doi:10.1158/1538-7445.AM2013-LB-134
Abstract LB-157: IL-12p70 producing dendritic cell vaccine elicits Tc1 polarized T cells and extends time to progression in metastatic melanoma.
Authors: Carreno Beatriz M. , Becker-Hapak Michelle , Huang Alexander , Chan Megan , Alyasiry Amer , Lie Wen-Rong , Aft Rebecca L. , Cornelius Lynn A. , Trinkaus Katherine M. , Linette Gerald P.
Published: August 2014

Systemic administration of IL-12p70 has demonstrated clinical activity in cancer patients but dose-limiting toxicities have hindered its incorporation in vaccine formulations. In this proof-of-concept phase I clinical trial (NCT00683670), we report on the immunological and clinical outcomes upon vaccination of newly diagnosed stage IV melanoma patients with CD40L/IFN-γ matured IL-12p70 producing dendritic cells (mDC). HLA-A*0201+ individuals with treatment naïve metastatic melanoma were vaccinated with mDC pulsed with melanoma gp100-derived peptides, every 3 weeks by intravenous infusion for six doses, after a single dose of cyclophosphamide (300 mg/m2 iv). CT imaging was performed at baseline, week 9 and 18 for clinical assessment using RECIST. PBMC were taken weekly for immune monitoring by tetramer analysis and functional assays. Six of seven treated patients develop sustained T cell immunity to all three melanoma gp100 antigen-derived (G154, G209-2M and G280-9V) peptides, while one patient had transient immunity only to the G209-2M peptide. Three of the six immunological responders developed a radiographic response by RECIST criteria and all three individuals had a time to progression (TTP) >11.5 mo. A Cox regression analysis followed by likelihood-ratio test revealed a positive correlation (p=0.0198) between DC derived IL-12p70 and TTP. Moreover, among clinical responders, vaccine-induced gp100-specific T cells displayed a Tc1 phenotype. In contrast, a selective defect in IL-12p35 transcription was identified in clinical non-responder patient DC and gp100-specific T cells from these patients displayed the Tc2 phenotype. Incorporation of TLR3 and TLR8 agonists into the CD40L/IFN-γ maturation protocol corrected the IL-12p70 production defect in DC derived from clinical non-responder patients. These findings underscore the essential role of IL-12p70 in the development of type-1 immunity in humans with cancer and provide evidence-based rationale for incorporating IL-12p70 into the next generation of cancer vaccine formulations.

Citation Format: Beatriz M. Carreno, Michelle Becker-Hapak, Alexander Huang, Megan Chan, Amer Alyasiry, Wen-Rong Lie, Rebecca L. Aft, Lynn A. Cornelius, Katherine M. Trinkaus, Gerald P. Linette. IL-12p70 producing dendritic cell vaccine elicits Tc1 polarized T cells and extends time to progression in metastatic melanoma. [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 LB-157. doi:10.1158/1538-7445.AM2013-LB-157
Abstract LB-16: Breast cancer risk in association with occupational exposure to organic solvents.
Authors: Ekenga Christine , Parks Christine G. , D'Aloisio Aimee A. , DeRoo Lisa A. , Sandler Dale P.
Published: August 2014

Background: Organic solvents are widely used in occupational settings as adhesives, degreasing agents and cleaning products, and in the production of plastics and textiles. Several solvents have been recognized as human carcinogens; however, there is limited data on solvent exposure and the risk of breast cancer. The objective of this study was to examine the relationship between occupational exposure to organic solvents and breast cancer among women enrolled in the Sister Study.

Methods: The Sister Study is a prospective cohort of over 50,000 US and Puerto Rican women aged 35-74 with a family history of breast cancer; enrollment and completion of baseline questionnaires occurred between 2004 and 2009. This analysis includes 47,763 women who reported working outside the home. We categorized occupational solvent exposure using baseline data on self-reported use of solvents on each job held for 12 months or longer. Women were followed for breast cancer incidence through 2012. Cox regression analyses were performed, adjusting for established breast cancer risk factors, including parity and age at first birth.

Preliminary Results: A total of 1,596 women were diagnosed with invasive or in situ breast cancer during follow-up. Overall, there was no increased risk of breast cancer associated with lifetime use or duration of exposure to solvents (HR: 0.93, 95%CI: 0.79-1.09, p trend = 0.26). Among parous women, those who worked with solvents for five or more years prior to their first birth had an increased risk of breast cancer compared to women who never worked with solvents (HR: 2.12, 95%CI: 0.94-4.80, p trend = 0.02). Among all women, an increased risk was seen for solvent-exposed assemblers and fabricators (HR: 2.28, 95%CI: 1.13-4.57), and non-significantly elevated risks were noted among solvent-exposed cooks and nurses.

Conclusions: These findings suggest that occupational exposure to organic solvents prior to first birth, a critical period of breast tissue differentiation, may result in increased vulnerability for breast cancer. Our results also give some indication of increased risks for solvent-exposed women in production, service and healthcare occupations. Future studies on solvent-related breast cancer risk should focus on exposure time window and types of organic solvents used across different occupational settings.

Citation Format: Christine Ekenga, Christine G. Parks, Aimee A. D'Aloisio, Lisa A. DeRoo, Dale P. Sandler. Breast cancer risk in association with occupational exposure to organic solvents. [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 LB-16. doi:10.1158/1538-7445.AM2013-LB-16
Abstract LB-208: Small interfering RNA library screen to identify therapeutic transcription factor.
Authors: Hu Zhi , Gu Shenda , Gray Joe , Rantala Juha
Published: August 2014

Post-genomic analyses of major transcription factor families, in both malignant and non-malignant cell types, have resulted in a broader revision of understanding the biology of transcription factor families. A number of oncogenic transcription factors, such as activator protein (AP)-1, estrogen receptor(ER) and signal transducer and activator of transcription (STAT)-3/STAT-5, are overactivated in human carcinomas. Up to now, three main groups of transcription factors are known to be important in human cancer. Transcription factor-directed anticancer drug development has focused on membrane or cytosolic targeting of molecules acting as ligand receptors. Recent technologies, such as small interfering RNA (siRNA), have shifted transcription factor targeting toward a more sophisticated rationale to elucidate the mechanisms that govern gene expression by analyzing the functions of proteins commonly over-expressed in transformed and malignant cells. In this study, we've applied a cell spot microarray (CSMA) method which provides reproducible multi-parametric phenotypic readouts for large-scale gene knockdown genetic screens. A human transcription factor siRNA library including 350 transcription factor genes which were significantly overexpressed in human breast cancer was screened against 6 breast cancer cell lines including (Triple negative breast cancer, HER2 positive ER positive) SUM149, BT20, HCC1569, SKBR3, MDAMB361 and MCF7 for measuring cell proliferation using EdU incorporation, cell apoptosis with c-PARP staining. We ranked the candidate gene list by the change of the rate of EdU or level of c-PARP or the combination of both. Our data showed that the silencing of LHX1, BCL6, GABPA or SMAD1 increased the c-PARP levels in most of cell lines. The Knockdown of ZNF215, NFATC1, HOXD4 or ZNF169 reduced the levels of EdU staining. Selected siRNAs were then tested on more different breast cancer cell lines to confirm the spectrum of activity. In the near future, based on this pilot screen, a complete siRNA library of transcription factors including 1000 gene list will be tested on our panel of 50 breast cancer cell lines. Our screen will provide comprehensive information on the central role of transcription factor in breast cancer, and will lead to the identity of novel therapeutics selectively against transcription factors.

Citation Format: Zhi Hu, Shenda Gu, Joe Gray, Juha Rantala. Small interfering RNA library screen to identify therapeutic transcription factor. [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 LB-208. doi:10.1158/1538-7445.AM2013-LB-208
Abstract LB-221: Inhibition of rapamycin-induced feedback activation of AKT with dasatinib induces complete tumor regression in a preclinical model of breast cancer.
Authors: Yori Jennifer L. , Lozada Kristen , Seachrist Darcie D. , Mosley Jonathan , Abdul-Karim Fadi W. , Booth Christine N. , Flask Chris A. , Keri Ruth A.
Published: August 2014

Resistance to receptor tyrosine kinase (RTK) blockade in breast cancer treatment is commonly mediated by activation of bypass pathways that sustain growth. We propose moving away from the individual targeting of RTKs to inhibit multiple commonly activated, overlapping, and essential downstream pathways. The mammalian Target of Rapamycin (mTOR) and the non-receptor tyrosine kinase, Src, are two intrinsic targets that intersect downstream of most RTKs. To date, limited clinical efficacy has been shown with either mTOR or Src inhibitors as single agents. Here we show that dasatinib, a dual Src/c-abl inhibitor, is able to block the well-established de-repression of AKT that occurs with rapamycin inhibition of mTOR. Furthermore, dual inhibition of these distinct, but compensatory arms of RTK signaling results in rapid and complete regression in over 80% of MMTV-PyMT-induced mammary tumors, with only moderate effects on tumor inhibition as single agents. Importantly, Src and mTOR pathway co-activation occurs in nearly half of human breast cancers, independent of tumor sub-type. These studies support the evaluation of combined mTOR and Src inhibitors in breast cancer patients. Such inhibitors are currently FDA approved, expediting the transition to clinical safety and efficacy trials. We expect this approach will prevent molecular evolution of bypass pathways and induce tumor regression.

Citation Format: Jennifer L. Yori, Kristen Lozada, Darcie D. Seachrist, Jonathan Mosley, Fadi W. Abdul-Karim, Christine N. Booth, Chris A. Flask, Ruth A. Keri. Inhibition of rapamycin-induced feedback activation of AKT with dasatinib induces complete tumor regression in a preclinical model of breast 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 LB-221. doi:10.1158/1538-7445.AM2013-LB-221
Abstract LB-230: Multiple omics profiling reveals the evolutionary history of metastatic renal cell carcinoma.
Authors: Gao Shengjie , Yi Huang , Wu Song , Yu Yuan , Song Pengfei , Guo Guangwu , Hu Xueda
Published: August 2014

About 50% of renal cell carcinomas (RCCs) progress to the metastatic stage, and become fatal and incurable. Whether such a dismal prognosis is due to early dissemination or late diagnosis of the disease remains unknown. To explore the evolutionary history of metastatic RCC (mRCC), we characterized the genetic, epigenetic and expression profiles of multiple tumors from a mRCC patient, including primary RCC (pRCC), local metastasis in vena cava (MVC) and distant metastasis in brain (MB). Although the multi-omics profiles of bulk tumor tissues differed substantially from each other, quantitative analysis of the multi-level data suggested mRCCs to be resulted from clonal expansion of the rare advantageous subclone developed within the heterogeneous pRCC. Moreover, from the genetic distances between mRCCs and their parental subclone, we estimated that about two and eight years were required for the parental subclone to evolve into progeny subclones that give rise to MVC and MB, respectively. Thus, distant metastasis occurred late during RCC progression and there was a broad window period for early detection of the circulating tumor cells before pRCC acquired full metastatic potential. These findings proved that early detection, followed by early intervention, is possible and necessary for controlling the spread of RCC.

Citation Format: Shengjie Gao, Huang Yi, Song Wu, Yuan Yu, Pengfei Song, Guangwu Guo, Xueda Hu. Multiple omics profiling reveals the evolutionary history of metastatic renal cell 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 LB-230. doi:10.1158/1538-7445.AM2013-LB-230
Abstract LB-243: microRNA mimics: siRNA lessons apply. miRNA mimics exhibit a significant off-target effect that is cell-line, length and dose dependent.
Authors: Goldgraben Mae A. , Git Anna , Rueda Oscar , Caldas Carlos
Published: August 2014

In light of the great success of siRNA reagents in modern research, similar reagents have also become increasingly popular to study miRNAs in cancer biology. To explore the endogenous function of a particular miRNA in fine-tuning target protein translation, synthetic mimics are transfected into host cells either to examine the effect of a candidate target 3′UTR on the expression of a reporter, or to identify new targets using microarray technology. Such studies typically employ a proprietary commercial universal negative control, whose suitability is taken for granted.

Methods: We transfected commercial miRNA mimics into a large panel of breast cancer cell lines (BT549, Cama1, HCC1500, MCF7, MDAMB134, MDAMB231 MDAMB436, MFM223, SUM159, ZR75-1) to identify endogenous targets of miR-155 using microarray analysis. ‘Seed’ and passenger-strand mutants were integrated into the study as additional controls.

Results: The resulting list of differentially-expressed genes often reflects a saturation of transcripts pertaining to a strong immune response to the transfected double-stranded RNA (dsRNA). Different cell lines exhibit variable sensitivity to dsRNA mimics, evident as the induction of the interferon pathway and apoptosis. Using custom variants of the mimics we show that this sequence-independent response is predominantly length-dependent and dose-dependent. Moreover, a substantial part of the remaining, seemingly sequence-specific response could be attributed to the passenger strand, assumed to be inert.

Conclusions and future work: Commercial miRNA mimics may have significant off-target effects that require careful controls to account for the phenotypes under study. In particular, ‘seed’ mutants rather than universal negative controls are of essence. Additionally, alternative methods of transient miRNA over-expression are currently under investigation to validate targets identified to date. Taken together, these lessons have significant implications for all areas of cancer biology where synthetic mimic transfections are a means for investigating the functional role of miRNAs in the cell.

Citation Format: Mae A. Goldgraben, Anna Git, Oscar Rueda, Carlos Caldas. microRNA mimics: siRNA lessons apply. miRNA mimics exhibit a significant off-target effect that is cell-line, length and dose dependent. [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 LB-243. doi:10.1158/1538-7445.AM2013-LB-243
Abstract LB-251: Comparison of MicroRNA deep sequencing of matched formalin-fixed paraffin-embedded and fresh frozen cancer tissues.
Authors: Meng Wei , McElroy Joseph , Volinia Stefano , Palatini Jeff , Warner Sarah , Ayers Leona , Palanichamy Kamalakannan , Chakravarti Arnab , Lautenschlaeger Tim
Published: August 2014

Purpose/Objective(s): MicroRNAs regulate several aspects of tumorigenesis and cancer progression. Most cancer tissues are archived formalin-fixed and paraffin-embedded (FFPE). While microRNAs are a more stable form of RNA thought to withstand FFPE-processing and degradation there is only limited evidence for the latter assumption. We examined whether microRNA profiling can be successfully conducted on FFPE cancer tissues using SOLiD ligation based sequencing.

Materials/Methods: Nine paired human malignant tissue samples were received. Remnant surgical tissues were taken after diagnostic samples were secured from patients (five males and four females; median age 58 years, range 39-78 years) with breast invasive ductal carcinoma (2), renal clear cell carcinoma (2), lung squamous cell carcinoma (1) and adenocarcinoma (1), prostate adenocarcinoma (1), metastatic melanoma (1), and sarcoma of thigh (1). RNA from FFPE samples were extracted using Recover All Total Nucleic Acid Isolation Kit (Life Technologies Corporation, Carlsbad, CA). Small RNAs from FFPE and fresh frozen samples were prepared for SOLiD (Version 4) system, and reads data were analyzed by using the SOLiD™ small RNA Analysis pipeline (Life Technologies), then normalized as reads per million (RPM).

Results: Tissue storage times (2-9 years) appeared to not affect the number of detected microRNAs in FFPE samples compared to matched frozen samples (paired t-test p>0.7). Correlations of microRNA expression values were very high across microRNAs in a given sample (Pearson's r=0.74-0.94). Higher variance of expression values among samples was associated with higher correlation coefficients between FFPE and frozen tissues. One of the FFPE samples in this study was degraded for unknown reasons with a peak read length of 17 nucleotides compared to 21 in all other samples. The number of detected microRNAs in this sample was within the range of microRNAs detected in all other samples.

Conclusion: Ligation-based microRNA deep sequencing on FFPE cancer tissues is feasible and RNA degradation to the degree observed in our study appears to not affect the number of microRNAs that can be quantified.

Citation Format: Wei Meng, Joseph McElroy, Stefano Volinia, Jeff Palatini, Sarah Warner, Leona Ayers, Kamalakannan Palanichamy, Arnab Chakravarti, Tim Lautenschlaeger. Comparison of MicroRNA deep sequencing of matched formalin-fixed paraffin-embedded and fresh frozen cancer tissues. [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 LB-251. doi:10.1158/1538-7445.AM2013-LB-251
Abstract LB-281: The role of POU5F1B in prostate cancer.
Authors: Jiang Hongmei , Wang Man-Tzu , Nie Daotai
Published: August 2014

POU5F1B is the one of the pseudogenes of POU5F1 (also known as Oct3, Oct4) with protein-coding potential. It is localized on chromosome 8q24.21, inside of the 1.2 Mb “gene desert” between the FAM84B and the c-MYC gene, which is closely associated with prostate cancer risk. Recent studies showed that POU5F1B, but not POU5F1, is expressed in prostate tissue and is overexpressed in prostatic carcinoma, compared to normal prostatic tissue surrounding the carcinoma. However, the role of POU5F1B in prostate cancer is still unknown. Through in silico analysis of dataset HG-U95A, we found that POU5F1B expression is increased in prostate tumor and markedly increased in metastatic tumors. Western blot analysis revealed a marked increase in POU5F1B expression in prostate cancer cells when compared to non-tumorigenic RWPE-1 cells. To study the role of POU5F1B in prostate cancer, we cloned POU5F1B from prostate cancer cells, sequenced the amplicons, and found several polymorphism. We made pCDH-myc-POU5F1B constructs and expressed POU5F1B in prostate cancer cell lines LNCaP, DU145, and PC-3. Overexpression of POU5F1B in LNCaP, DU145 and PC3 cells can increase cell invasion using Boyden chamber assay. Overexpression of POU5F1B in LNCaP cells also promotes colony formation in soft agar. We also found that DU145 cells with POU5F1B overexpression lost cell-cell contact, compared to DU145-pCDH vector cells, and further found that CDH1 expression is downregulated in DU145-POU5F1B cells. Depletion of POU5F1B reduced the tumor forming ability of LNCaP cells in vivo. The data collectively suggest an important role of POU5F1B in prostate tumor formation and progression.

Citation Format: Hongmei Jiang, Man-Tzu Wang, Daotai Nie. The role of POU5F1B in prostate 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 LB-281. doi:10.1158/1538-7445.AM2013-LB-281
Abstract LB-305: Novel Rac1-GEF inhibitors as anticancer agents for aggressive tumors.
Authors: Cardama Georgina A. , Gonzalez Nazareno , Comin Maria Julieta , Turjanski Adrian G. , Alonso Daniel Fernando , Gomez Daniel Eduardo , Menna Pablo Lorenzano
Published: August 2014

Small GTPases of the Rho family, including Rac1, regulate fundamental cellular processes like actin cytoskeleton reorganization, cell migration and cell cycle progression. Rac1 has been associated with transformation, tumor progression and tumor cell migration in different type of cancers, including aggressive breast cancer and glioma. These proteins cycle between an active, GTP-bound state and an inactive, GDP-bound state. This cycle is highly regulated by many regulatory proteins, including activators such as guanine nucleotide exchange factors (GEFs).

We searched for Rac1 inhibitors able to interfere Rac1-GEF interaction using a docking-based virtual library screening approach. We selected ZINC69391 compound. This small-molecule was able to interfere Rac-Tiam1 and Rac-DOCK180 interaction in vitro and reduced Rac1-GTP intracellular levels but had no effect on the closely related Cdc42 GTPase. ZINC69391 also affected the activation of Pak1, one important Rac1 effector. This compound reduced cell migration, inhibited cell proliferation and arrested cell cycle progression in breast cancer cells and glioma cells. We also evaluated this compound in vivo and ZINC69391 was able to reduce 60% lung colonization in a breast cancer experimental metastasis model. We further evaluated novel analogs looking for more potent and specific Rac1 inhibitors. We synthesized a group of novel disubstituted guanidines and we screened these analogs in vitro. One of them, 1A-116 analog, showed to be more potent than the parental compound, reducing cancer cell proliferation and Rac1 activation at the low micromolar range. These data further confirm Rac1 GTPase as a valuable molecular target for anti-cancer therapies and drug development in breast cancer and glioma, where Rac1 presents a relevant role.

Citation Format: Georgina A. Cardama, Nazareno Gonzalez, Maria Julieta Comin, Adrian G. Turjanski, Daniel Fernando Alonso, Daniel Eduardo Gomez, Pablo Lorenzano Menna. Novel Rac1-GEF inhibitors as anticancer agents for aggressive tumors. [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 LB-305. doi:10.1158/1538-7445.AM2013-LB-305
Abstract LB-33: TRPV1 suppresses intestinal tumorigenesis by negatively regulating EGFR signaling.
Authors: de Jong Petrus R. , Takahashi Naoki , Harris Alexandra R. , Lee Jihyung , Bertin Samuel , Raz Eyal
Published: August 2014

The intestinal epithelium is the most rapidly self-renewing tissue. This dynamic process is mainly driven by Wnt, Notch and EGFR signaling in the crypts of Lieberkühn. These signaling pathways are negatively regulated by multiple control mechanisms to restrain intestinal epithelial cell (IEC) turnover and thereby reduce the risk of oncogenic transformation. Here we report a novel homeostatic feedback loop, intrinsic to IEC, between the EGFR and a member of the transient receptor potential (TRP) ion channel family. We identified that TRP vanilloid 1 (TRPV1), a polymodal pain receptor, is expressed by IEC and that this channel negatively regulates EGFR-induced cell proliferation in vivo. Intestinal crypt cultures (organoids) from Trpv1-/- mice showed hyperproliferation, crypt elongation and a reduced requirement for exogenous EGF compared to WT controls. Importantly, genetic deletion of Trpv1 increased the intestinal tumor load in multiple intestinal neoplasia (Apc+/min) mice, which was reversed by EGFR kinase inhibitor treatment. Continuous oral administration of a dietary TRPV1 agonist, capsaicin, suppressed intestinal tumorigenesis in Apc+/min mice in a TRPV1-dependent manner. In addition we found that capsaicin worked synergistically with a COX2 inhibitor, celecoxib, in the prevention of intestinal neoplasia development in these mice. Mechanistically, we show that TRPV1 is activated by EGFR signaling through phospholipase C (PLC). TRPV1 signaling subsequently restrains EGFR signaling through Ca2+-dependent triggering of protein tyrosine phosphatase (PTP) activity. Together, these findings suggest an intrinsic mechanism that exerts negative feedback on EGFR signaling through Ca2+ channel TRPV1 that thereby acts as a tumor suppressor in the intestinal epithelium.

Citation Format: Petrus R. de Jong, Naoki Takahashi, Alexandra R. Harris, Jihyung Lee, Samuel Bertin, Eyal Raz. TRPV1 suppresses intestinal tumorigenesis by negatively regulating EGFR signaling. [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 LB-33. doi:10.1158/1538-7445.AM2013-LB-33
Abstract LB-35: Site specific activation of AKT protects cells from death induced by glucose deprivation .
Authors: Gao Meng , Liang Jiyong , Lu Yiling , Guo Huifang , German Peter , Bai Shanshan , Jonasch Eric , Yang Xingsheng , Mills Gordon B. , Ding Zhiyong
Published: August 2014

The serine/threonine kinase AKT is a key mediator of cancer cell survival. We demonstrate that transient glucose deprivation modestly induces AKT phosphorylation at both Thr308 and Ser473. In contrast, prolonged glucose deprivation induces selective AKT phosphorylation at Thr308 and phosphorylation of a distinct subset of AKT downstream targets leading to cell survival under metabolic stress. Glucose deprivation-induced AKT Thr308 phosphorylation is dependent on PDK1 and PI3K but not EGFR or IGF1R. Prolonged glucose-deprivation induces the formation of a complex of AKT, PDK1, and the GRP78 chaperone protein, directing phosphorylation of AKT at Thr308 but not Ser473. Our results reveal a novel mechanism of AKT activation under prolonged metabolic stress that protects cells from metabolic stress. The selective activation of AKT phosphorylation at Thr308 that occurs during prolonged nutrient deprivation may provide an unexpected opportunity for the development and implementation of drugs targeting cell metabolism and aberrant AKT signaling.

Citation Format: Meng Gao, Jiyong Liang, Yiling Lu, Huifang Guo, Peter German, Shanshan Bai, Eric Jonasch, Xingsheng Yang, Gordon B. Mills, Zhiyong Ding. Site specific activation of AKT protects cells from death induced by glucose deprivation . [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 LB-35. doi:10.1158/1538-7445.AM2013-LB-35
Abstract LB-44: A novel PUMA inhibitor protects against chemotherapy-induced intestinal injury without compromising tumor response.
Authors: Leibowitz Brian J. , Li Mei , Wei Liang , Zhang Lin , Yu Jian
Published: August 2014

PUMA is a BH3-only member of the Bcl2 family that is a critical mediator of apoptosis in response to a variety of stimuli, and plays a particularly strong role in gastrointestinal and hematopoietic stem cell apoptosis following radiation. In this study we found that PUMA-dependent apoptosis mediates gastrointestinal injury induced by chemotherapeutic agents, indicating its critical role in DNA damage induced intestinal injury. PUMA neutralizes all known anti-apoptotic Bcl-2 family members through high-affinity interactions with its BH3 domain, thus facilitating activation of the intrinsic apoptotic pathway. Based on these interactions, we devised a pharmacophore model to mimic them, with the goal being a small molecule that prevents PUMA interaction with Bcl-2 family proteins. In silico screening of the ZINC 8.0 database yielded 142 potential compounds, 13 of which had favorable toxicity profiles. Extensive in vitro testing further narrowed the list to two lead compounds, one of which demonstrated significant in vivo activities. This lead compound significantly protected the intestinal stem cells from apoptosis induced by Irinotecan (CPT-11) and 5-Fluorouracil (5-FU). Utilizing a Lewis Lung Carcinoma (LLC) syngeneic tumor model, we found that treatment of C57/B6 mice with the experimental PUMA inhibitor (I.P.) significantly decreased CPT-11-induced apoptosis in the intestinal crypt base, similarly to that observed in PUMA KO animals. This treatment significantly preserved intestinal morphology and decreased weight loss in tumor bearing mice. Further, we found that administration of the PUMA inhibitor did not alter the tumor response to CPT-11. These findings suggest the feasibility of retaining the efficacy of chemotherapy while mitigating GI adverse effects with a small molecule. Further experiments will determine the inhibitor's pharmacokinetics and pharmacodynamics, as well as its mechanisms of action in vivo.

Citation Format: Brian J. Leibowitz, Mei Li, Liang Wei, Lin Zhang, Jian Yu. A novel PUMA inhibitor protects against chemotherapy-induced intestinal injury without compromising tumor response. [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 LB-44. doi:10.1158/1538-7445.AM2013-LB-44
Abstract LB-46: C/EBPα acts as tumor suppressor in lung cancer by inhibiting the proto-oncogene Bmi-1.
Authors: Levantini Elena , Basseres Daniela S. , Zhang Wen Cai , Welner Robert S. , Alberich-Jorda' Meritxell , Yong Kol Jia , Thakkar Bhavin M. , Zhang Junyan , Battelli Chiara , Hetherington Christopher J. , Ye Min , O'Brien Karen , Magli Maria Cristina , Loh Marie , Nga Min En , Pang Yin Huei , Borczuk Alain C. , Varticovski Lyuba , Kocher Olivier , Zhang Pu , Soo Ross A. , Lim Bing , Halmos Balazs , Tenen Daniel G.
Published: August 2014

C/EBPα gene expression is frequently lost in non-small cell lung cancer, suggesting it acts as a tumor suppressor. Here, we generated an inducible lung-specific mouse model of C/EBPα deletion (C/EBPαLung-Δ mice) that develops lung adenocarcinomas. We observed that C/EBPα excision results in upregulation of Bmi-1, and that tumor initiation strictly depends on Bmi-1 gene dosage, as C/EBPαLung-Δ mice carrying only one functional Bmi-1 allele escape tumorigenesis. Accordingly, C/EBPα negative human adenocarcinomas show elevated Bmi-1 expression, in line with our observation that C/EBPα acts as tumor suppressor in lung cells by directly inhibiting Bmi-1 transcription. Furthermore, pharmacological inhibition of Bmi-1 impairs the ability of C/EBPα null adenocarcinoma cells to form tumors in xenografts. Overall, we have identified Bmi-1 as a critical therapeutic target in those patients carrying abnormal C/EBPα function.

Citation Format: Elena Levantini, Daniela S. Basseres, Wen Cai Zhang, Robert S. Welner, Meritxell Alberich-Jorda’, Kol Jia Yong, Bhavin M. Thakkar, Junyan Zhang, Chiara Battelli, Christopher J. Hetherington, Min Ye, Karen O'Brien, Maria Cristina Magli, Marie Loh, Min En Nga, Yin Huei Pang, Alain C. Borczuk, Lyuba Varticovski, Olivier Kocher, Pu Zhang, Ross A. Soo, Bing Lim, Balazs Halmos, Daniel G. Tenen. C/EBPα acts as tumor suppressor in lung cancer by inhibiting the proto-oncogene Bmi-1. [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 LB-46. doi:10.1158/1538-7445.AM2013-LB-46
Abstract LB-6: Non-covalent assembly of meso-tetra-4-pyridyl porphine with single-stranded DNA to form nano-sized complexes with pH-dependent DNA release and anti-tumor activity.
Authors: Gmeiner William H. , Ghosh Supratim , Ucer Kamil B. , Williams Richard T. , D'Agostino Ralph , Grant Ken , Sirintrapun Joseph , Thomas Michael , Hantgan Roy , Bharadwaj Manish
Published: August 2014

Porphyrin-based nanomaterials frequently require non-physiological conditions to promote non-covalent assembly limiting therapeutic utility. In the present studies, we demonstrate that single-stranded DNA (ssDNA) modulates non-covalent assembly of meso-tetra-4-pyridyl porphine (MTP) and that the resulting porphyrin:DNA nano-sized complexes (PDN) are stable indefinitely in aqueous solution under physiologically relevant conditions and undergo pH-dependent DNA release under moderately acidic conditions (pH 5.1) that protonate the pyridyl nitrogens of MTP. The biological utility of pH-dependent DNA release from PDN was demonstrated by endosomal release of DNA in cancer cells. PDN formation is DNA-dependent with the ratio of porphyrin:DNA being approximately two DNA nucleobases per porphyrin consistent with half the pyridyl side chains of MTP interacting with DNA nucleobases. Raman spectra display surface-enhanced features for the porphyrin in the context of PDN consistent with π-π stacking of porphyrins and DNA nucleobases being a principal driving force for PDN assembly, a result also consistent with enhanced PDN dissociation in more hydrophobic solvent systems. PDN produce reactive oxygen species (ROS) in a light-dependent manner under conditions that favor dissociation, such as in hydrophobic environments as occurs upon endocytosis or in the presence of hydrophobic solvents. PDN induce light-dependent cytotoxicity in vitro and anti-tumor activity towards bladder cancer xenografts in vivo. Light-dependent, PDN-mediated cell death resulted from ROS-mediated localized membrane damage with mass spectrometry confirming the generation of the lipid peroxidation products9- and 13-hydroxy octadecanoic acid. Our results demonstrate that PDN have properties useful for therapeutic applications, including cancer treatment.

Citation Format: William H. Gmeiner, Supratim Ghosh, Kamil B. Ucer, Richard T. Williams, Ralph D'Agostino, Ken Grant, Joseph Sirintrapun, Michael Thomas, Roy Hantgan, Manish Bharadwaj. Non-covalent assembly of meso-tetra-4-pyridyl porphine with single-stranded DNA to form nano-sized complexes with pH-dependent DNA release and anti-tumor activity. [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 LB-6. doi:10.1158/1538-7445.AM2013-LB-6
Abstract LB-73: Circulating tumor cells with the invasive phenotype predict progression free survival and overall survival in preoperative patients diagnosed with advanced epithelial ovarian cancer.
Authors: Chen Wen-Tien , Zhao Qiang , Dong Huan , Yang Jie , Zhang Qiao , Fan Tina , Golightly Marc G. , Dessio Whitney C. , Madajewicz Stefan , Henretta Melissa , Pearl Michael L.
Published: August 2014

Purpose: Circulating tumor cells (CTCs) might function as prognostic markers for monitoring and assessing therapy efficacy ex vivo. This study aimed to measure overall population of CTCs based on expression of epithelial lineage (Epi) markers and the subpopulation of CTCs with the invasive phenotype (iCTCs) in preoperative patients for prognosis of advanced Epithelial Ovarian Cancer (EOC).

Experimental Design: CTCs and iCTCs enriched by the Cell Adhesion Matrix (CAM)-coated devices from 122 preoperative patients were identified as Epi+ nucleic acid (NA)+ hematopoietic lineage (HL)- cells and CAM uptake (CAM+) Epi+ NA+ HL- cells, respectively. CTCs and iCTCs were enumerated using multiplex flow cytometry, validated by microscopy, and correlated with overall survival (OS) and progression-free survival (PFS).

Results: iCTCs were detected in 0/39 (0%) benign patients, 5/11 (45.5%) Stage I, 2/4 (50%) Stage II, 41/43 (95.3%) Stage III and 16/16 (100%) stage IV patients (P-value <0.001). However, healthy (n=48) and benign women had noticeable CTCs (mean=10 and 3 CTCs/1.0-mL blood, respectively), and large variation (IQR=24.5 and 30 CTCs/1.0-mL blood, respectively), although CTCs were significantly different across different stage groups. Kaplan-Meier estimates of OS at 5 years in the iCTC positive and negative groups were 15.4% (95% CI, 7.2% to 26.3%) and 94% (95% CI, 82.5% to 98%), respectively. The PFS in the iCTC positive group was also significantly lower than that in the negative group (P-value <0.001). In multivariable Cox models, iCTCs were independently predictive of OS (P-value <0.001) and provided predictive power for disease recurrence independent of diagnostic disease stages, age, debulking status and platinum sensitivity.

Conclusion: CTCs show the expression of heterogeneous epithelial antigens with potential biologic relevance. Co-expression of epithelial antigens and invasiveness of iCTCs in preoperative patients provides prognosis of advanced EOC that could help tailor appropriate therapy.

Citation Format: Wen-Tien Chen, Qiang Zhao, Huan Dong, Jie Yang, Qiao Zhang, Tina Fan, Marc G. Golightly, Whitney C. Dessio, Stefan Madajewicz, Melissa Henretta, Michael L. Pearl. Circulating tumor cells with the invasive phenotype predict progression free survival and overall survival in preoperative patients diagnosed with advanced epithelial ovarian 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 LB-73. doi:10.1158/1538-7445.AM2013-LB-73
Abstract LB-89: A combined epigenetic and genetic biomarker panel for detection of lung cancer.
Authors: Wang Michael X. , Guo Dan , Andersen Mary , Guntur Vamsi
Published: August 2014

Introduction: Lung cancer is the leading cause of cancer-related deaths in human. However, there is no valid screening procedure or test available at the present time. Although National Lung Screening Trial (NLST) demonstrated, for the first time, that low-dose helical CT screening in high-risk population reduced lung cancer mortality by 20%, the procedure is associated with over 95% false positive results (Aberle DR et al. N Engl J Med. 2011, 365:395). A confirmatory test is urgently needed. We have been developing a combined epigenetic and genetic molecular biomarker panel to verify the presence of lung cancer on the blood samples. Methods: Lung cancer cell lines NCI-H69 (small cell carcinoma), NCI-H1299 and NCI-H460 (large cell lung cancer), NCI-H1781 and A549 (adenocarcinoma), NCI- H358 (bronchioalveolar carcinoma) and NCI-H520 (squamous cell carcinoma) were obtained from ATCC (Manassas, VA). Blood samples of patients with lung cancer (n=105) and non-cancer patients were collected at MU Health Care System with an IRB approval. Genomic DNA was extracted from cell lines, mononuclear cell fraction and plasma using QIAamp DNA mini kit and circulating nucleic acid kit (QIAGEN, Valencia, CA), respectively. Isolated DNAs were digested with 4 methylation sensitive restriction enzymes followed by PCR for DNA methylation assay. Genomic DNAs were also subject to allele-specific PCR for PT53, EGFR and BRAF gene mutation assay. All PCR reactions were carried out in an iQ5 Real-time PCR system (Bio-Rad, Hercules, CA). Results: Specific CGI DNA methylation of HOXA7, HOXA6 and PCDHGA12A was detected in all lung cancer cell lines except NCI-H1299 in HOXA7. Only NCI-H460 was positive for EGFR L858R mutation. Among patient blood samples, HOXA7 methylation was detectable in 9 out of 105 patient mononuclear cell DNAs, but neither in patient plasma nor in non-cancer patients or normal blood control DNAs. EGFR L858R mutation was detected in only 4 lung cancer patient DNA samples. The sensitivity of HOXA7 DNA methylation assay, determined by serial dilutions of cancer cell DNA into normal DNA, was 0.1%. Conclusion: A combined epigenetic DNA methylation and genetic mutation panel could be utilized for lung cancer detection or verification in patient blood sample.

Citation Format: Michael X. Wang, Dan Guo, Mary Andersen, Vamsi Guntur. A combined epigenetic and genetic biomarker panel for detection of 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 LB-89. doi:10.1158/1538-7445.AM2013-LB-89
Abstract LB-97: Aurora kinase inhibition suppresses colon cancer cell growth through NF-κb-mediated PUMA induction.
Authors: Sun Jing , He Kan , Yu Jian , Zhang Lin
Published: August 2014

Aurora kinases are a group of highly conserved protein kinases that play a key role in mitosis. It has been shown that aurora kinases are overexpressed in a variety of tumors, and their overexpression contributes to aneuploidy in cancer cells. Inhibitors of aurora kinases have been developed and showed promises in recent studies. However, the mechanisms by which aurora kinase inhibitors suppress tumor cell growth have remained unclear. In this study, we found that ZM-447439, an aurora B inhibitor that has been tested in a number of preclinical studies, suppressed colon cancer cell growth by inducing apoptosis through PUMA, a p53 downstream target and a BH3-only Bcl-2 family protein. Treatment with ZM-447439 strongly induced PUMA in a variety of colon cancer cells irrespective of their p53 status. The induction of PUMA by ZM-447439 is mediated by IκB-dependent activation of NF-κB, which directly binds to the PUMA promoter to activate its transcription. Deficiency in PUMA abrogated ZM-447439-induced apoptosis and caspase activation, and rendered ZM-447439 resistance in vitro and in vivo. Furthermore, chemosensitization by ZM-447439 was also found to be PUMA-dependent. Together, these results demonstrate a key role of PUMA-dependent apoptosis in mediating the therapeutic effect of aurora kinase inhibition. They provide a rationale for manipulating the apoptotic machinery to improve sensitivity and overcome resistance to aurora kinase inhibitors.

Citation Format: Jing Sun, Kan He, Jian Yu, Lin Zhang. Aurora kinase inhibition suppresses colon cancer cell growth through NF-κb-mediated PUMA induction. [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 LB-97. doi:10.1158/1538-7445.AM2013-LB-97