bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1652: A new approach to study intracellular pathways of metastasis in living tumor cells.
Authors: Colbert Leiam , Ward Christopher W. , Onel Kenan 
Published: August 2014

Abstract
Although genes associated with metastasis have been identified, the core intracellular events of the process remain obscure. Recently, it has been shown that cytoskeletal reorganisations, indicated by changes in the tensional force generated by the actin-myosin interaction in the cell, are critical for the development of invasive phenotypes. These changes are mediated in part by the microenvironment through mechanotransduction (6,7). Moreover, reduced cytoskeletal stiffness and increased mutability can distinguish metastatic cells from non[[Unsupported Character - Codename &shy;]]invasive cancer cells and from normal cells. This suggests that many cancer cells are distinguished by altered physical properties and that biomechanical measurements of isolated cells may have significant diagnostic and prognostic value (2-4, 8). Thus, we hypothesize that by using isogenic cancer cell lines of differing metastatic potential transfected with fluorescently labelled motility reporter constructs, we will be able to elucidate altered mechanotransduction signalling as an important component in tumour formation and progression, which can then be studied mechanistically.
We have recently demonstrated novel cytoskeleton dependent mechanotransduction pathways in heart (5) and skeletal muscle (1) cells in which stretch-dependent signal transduction activates the local production of reactive oxygen species (ROS) to trigger Ca2+ signaling events. These discoveries were made possible by combining new mechano-optical techniques. We intend to apply this approach to further investigate abnormal kinase-mediated sensing of mechanical cues that may result in the development of fundamental abnormalities in the cancer microvasculature. We present preliminary data from different cancer lines that suggest manipulating kinase-mediated tension, using different inhibitors (ROCK inhibitor Y27632, MAPK inhibitor U0126), alone or jointly with one another can reprogram the tumour cells so that they normalize their reorientation response to cyclic strain and their ability to form networks (9).
Citation Format: Leiam Colbert, Christopher W. Ward, Kenan Onel. A new approach to study intracellular pathways of metastasis in living tumor 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 1652. doi:10.1158/1538-7445.AM2013-1652
Abstract 1656: Mouse embryonic fibroblasts null for krüppel-like factor 4 show reduced autophagy and elevated mTOR activity.
Authors: Engda Hagos , DeRoo Elise 
Published: August 2014

Abstract
Krüppel-like factor 4 (KLF4) is a zinc-finger transcription factor named for its homology to the Drosophila protein Krüppel. KLF4 negatively regulates cell-cycle progression and, cell proliferation, and is a known tumor suppressor in certain cancers. Autophagy, or self-eating, is a process through which intracellular aggregates can be degraded and their components recycled. The role of autophagy in cancer appears to be context dependent. In pre-cancerous tissue, autophagy may serve a protective purpose, removing cytotoxic aggregates and promoting a healthy intracellular environment. In cancerous tissue, however, autophagy may allow cancer cell survival. Previous studies examining gene expression in WT (KLF4+/+) and KLF4 null (KLF4-/-) mouse embryonic fibroblasts (MEFs) revealed autophagy related gene expression to be downregulated in KLF4-/- MEFs. In order to evaluate whether KLF4 is important in autophagy, we examined microtubule associated protein-1 light chain 3 protein (LC3, a marker of autophagy) and a downstream target of mTOR (p70S6K, a marker of autophagy inhibition) in KLF4+/+ and KLF4-/- MEFs. Our results show that levels of LC3 are reduced and levels of p70S6K are elevated in both KLF4-/- MEFs and MEFs in which KLF4 has been transiently silenced. Rapamycin treatment, which inhibits mTOR activity, fails to restore autophagy in KLF4 null MEFs. Collectively, these findings suggest that KLF4 may negatively regulate mTOR activity and that KLF4 may also be necessary for induction of autophagy either downstream or entirely independent of mTOR.
Citation Format: Hagos Engda, Elise DeRoo. Mouse embryonic fibroblasts null for krüppel-like factor 4 show reduced autophagy and elevated mTOR 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 1656. doi:10.1158/1538-7445.AM2013-1656
Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 1658: Cell death and growth arrest pathways mediating the actions of stilbene 5c in HCT-116 colon cancer cells and B16F10 melanoma cells.
Authors: Alotaibi Moureq R. 
Published: August 2014

Abstract
The stilbene derivative, cis-3, 4’, 5-trimethoxy-3’-aminostilbene (stilbene 5c), is a potentially potent antitumor agent that acts via binding to the colchicine-binding pocket in microtubules. Earlier studies have shown that stilbene 5c induces cell death in ovarian cancer cells and leukemic cells (Cao TM et al. Am J Hematol. 2008;83:390-7; Durrant D et al. Gynecol Oncol. 2008; 110:110-7).). The present study was designed to investigate the effectiveness of this microtubule poison against the HCT-116 human colon cancer cell line as well as B16F10 melanoma cells and its mechanisms of action. Time course studies demonstrated that stilbene 5c produces a decrease in cell viability in both cell lines. The capacity of the cells to proliferate was not restored upon removal of the drug after 5 days of exposure. Consistent with the results of the time course studies, β-galactosidase staining indicated that treatment with stilbene 5c also promotes senescence. In addition to senescence, HCT-116 cells and B16F10 melanoma cells treated with stilbene 5c displayed formation of autophagic vesicles by acridine orange staining, which was supported by fluorescence-activated cell sorting (FACS). Further evidence of autophagy was derived from treatment of HCT116 cells expressing an RFP-LC3 construct with stilbene 5c, in which LC3 puncta formation increased in a time-dependent manner. DAPI staining, TUNEL, and Annexin 5 staining indicated that apoptosis is also occurring in stilbene 5c-treated HCT-116 cells. Cell cycle analysis of HCT116 cells demonstrated growth arrest at both G1 and G2/M, and an increase in the subG1 population at days 3 and 5, which correspond to senescence and apoptosis respectively. Interestingly, DAPI and Hoechst staining of HCT116 cells revealed morphological changes in the cell nuclei (binucleated and micronucleated cells), which suggest that mitotic catastrophe may also serve as a mode of cell death after treatment with stilbene 5c. Our studies also indicated that stilbene 5c works in a p53-independent manner. p53-null HCT116 cells demonstrated similar sensitivity to stilbene as p53-wild type HCT116 cells. Consistent with previous studies in other experimental cancer models, this work indicates that stilbene 5c could potentially be effective against melanoma and colon cancer through the promotion of multiple modes of cell death.
Citation Format: Moureq R. Alotaibi. Cell death and growth arrest pathways mediating the actions of stilbene 5c in HCT-116 colon cancer cells and B16F10 melanoma 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 1658. doi:10.1158/1538-7445.AM2013-1658
Abstract 1664: A delicate balance between radiation-induced autophagy and apoptosis in HPV-positive head and neck cancer.
Authors: Fowler Tyler L. , Ludwig Kai D. , Djavadian Reza , Bednarz Bryan P. , Kimple Randall J. 
Published: August 2014

Abstract
Purpose: The molecular mechanisms responsible for improved outcomes seen in patients with human papillomavirus (HPV) positive head and neck cancer (HNC) remain largely unknown. Ionizing radiation can induce autophagy, a genetically programmed, evolutionarily conserved response to stress whereby cellular constituents are engulfed, digested, and recycled to sustain cellular metabolism. We investigated whether radiation-induced cellular autophagy is modulated by HPV oncogenes leading to altered therapeutic responses between HPV+ and HPV- HNCs.
Methods: An immortalized human tonsillar epithelial (HTE) cell line engineered to stably express LXSN vector alone, HPV-16 E6, or HPV-16 E7 was used for all experiments. All constructs received a single radiation dose of 4 Gy. Radiation survival was assessed by clonogenic survival. Activation of autophagy proteins LC3-A and LC3-B were analyzed at 4 and 24 hr time points using western blotting and fluorescence microscopy along with acridine orange staining. Apoptosis was evaluated by caspase activity at the same time points.
Results: HPV-16 E6 resulted in greater sensitivity, while HPV-16 E7 resulted in radiation resistance relative to than control cells (surviving fraction after 4 Gy = 8.4+/-0.5% vs. 35+/-3.8% vs. 20+/-1.1%, respectively, 1way ANOVA p&lt;0.0001). At baseline, expression of HPV-16 E6 had no affect on LC3-B expression while HPV-16 E7 and HPV-16 E6/E7 resulted in a significant increase in autophagy. Four hours following radiation, autophagy was increased in HPV-16 E6 (2.0 fold), E7 (2.6 fold) and E6/E7 (2.2 fold) expressing cells whereas vector and untransfected control cells showed no effect (1.2 and 1.1 fold, respectively). This increase was maximal at 4 hrs and had returned to baseline 24 hrs after radiation. No significant change in apoptosis was seen 4 hrs following radiation, but a gradual increase was seen between 12 and 48 hrs.
Conclusions: The HPV oncoproteins E7 up regulates autophagic pathways at baseline correlating with radiation resistance. Four hours following radiation, both E6 and E7 result in significant upregulation of autophagy. This is followed by upregulation of apoptosis, suggesting a transition from an initial protective response to cellular death.
Citation Format: Tyler L. Fowler, Kai D. Ludwig, Reza Djavadian, Bryan P. Bednarz, Randall J. Kimple. A delicate balance between radiation-induced autophagy and apoptosis in HPV-positive head and neck 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 1664. doi:10.1158/1538-7445.AM2013-1664
Abstract 1698: Evaluation of pesticide involvement in breast cancer.
Authors: Patterson Kathryn , Hale Julie , Bush Jason 
Published: August 2014

Abstract
There is considerable evidence linking cumulative and sustained exposure to estrogens as a key promoter of breast tumor proliferation. Chemicals with estrogenic activity can bind to the estrogen receptor (ER) to affect downstream signaling of estrogen-responsive genes. Organochlorines are a class of chemical pesticides that can act as xenoestrogens to disrupt normal endocrine function. Mitochondria play a significant role in maintenance of energy regulation and cellular detoxification and mitochondrial DNA is sensitive to levels of estrogen. Some members of the Estrogen Related Receptor (ERR) family are known to interact with hypoxia inducible factors to modulate mitochondrial response through the mTOR pathway which is pivotal to cell homeostasis and cellular detoxification. This study investigates the link between two organochlorine pesticides, Methoxychlor and Toxaphene, and the cellular effects by examining the hypothesis that exposure induces differential molecular pathways. Two breast cancer cell lines, MCF-7 (ER+) and MDA-MB-231 (ER-), and a normal breast epithelial cell line MCF-10A are used as a model to evaluate the response to Methoxychlor and Toxaphene treatment. Cytotoxicity studies established different sensitivities of the two breast cancer cell lines to pesticides. MCF-7 was more sensitive to both pesticides, which supports the premise that organochlorines may be acting as endocrine disruptors. Furthermore, pesticide-resistant clones of MCF-7 and MDA-MB-231 were established and compared to their sensitive counterparts. RNA was collected from cells treated in a hypoxic environment, cells treated with a high dose pesticide, and cells that had a co-treatment of hypoxia and pesticide for evaluation of ERR, hypoxic factor expression, and markers of mTOR pathway. Flow cytometry, RT-PCR and immunoblotting demonstrated that treatment affected mitosis and mitochondrial function and we found that ERR and hypoxic factor expression changed in a similar manner suggesting a common mechanism by pesticide treatment or hypoxic conditions. These results provide a basis for understanding specific pesticide-induced molecular mechanisms and their possible relationship to ER+ and ER- mammary epithelial biology.
Citation Format: Kathryn Patterson, Julie Hale, Jason Bush. Evaluation of pesticide involvement in 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 1698. doi:10.1158/1538-7445.AM2013-1698
Abstract 1716: Calcitriol and progesterone synergistically inhibit growth in endometrial cancer cells.
Authors: Lee Laura R. , Hood Brian L. , Nguyen Huyen , Kavandi Leyla , Turbov Jane M. , Thaete Larry G. , Hamilton Chad A. , Rodriguez Gustavo C. , Maxwell George L. , Conrads Thomas P. , Syed Viqar 
Published: August 2014

Abstract
Human studies suggest that progesterone and calcitriol may prove beneficial in preventing or inhibiting oncogenesis, but the underlying mechanism is not fully understood. The current study investigates the effects of progesterone, calcitriol and their combination on immortalized human endometrial epithelial cells and endometrial cancer cells and identifies their targets of action. The combined cell treatment enhanced vitamin D receptor expression and synergistically inhibited cell proliferation through caspase-3 activation and induction of G0/G1 cell cycle arrest with associated down-regulation of cyclin D1, D3 and p27 induction. We used mass spectrometry-based proteomics to measure protein abundance differences between calcitriol-, progesterone-, or combination-exposed endometrial cells. A total of 117 proteins showed differential expression amongst these three treatments. Four proteins were then selected for validation studies: histone H1.4 (HIST1H1E), histidine triad nucleotide-binding protein 2 (HINT2), interferon-induced, double-stranded RNA-activated protein kinase (EIF2AK2), and Bcl-2-associated X protein (BAX). Abundance levels of selected candidates were low in endometrial cancer cell lines versus the immortalized endometrial epithelial cell line. All four proteins displayed elevated expression in cancer cells upon exposure to calcitriol, progesterone or the combination. Further BAX analysis through gain or loss of function experiments revealed that upregulation of BAX decreased cell proliferation by changing the BAX:Bcl2 ratio. Knock down of BAX attenuated progesterone- and calcitriol-induced cell growth inhibition. Our results showed that progesterone and calcitriol up-regulate the expression of BAX along with other apoptosis-related proteins, which induced inhibition of endometrial cancer cell growth by apoptosis and cell cycle arrest.
Citation Format: Laura R. Lee, Brian L. Hood, Huyen Nguyen, Leyla Kavandi, Jane M. Turbov, Larry G. Thaete, Chad A. Hamilton, Gustavo C. Rodriguez, George L. Maxwell, Thomas P. Conrads, Viqar Syed. Calcitriol and progesterone synergistically inhibit growth in endometrial 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 1716. doi:10.1158/1538-7445.AM2013-1716
Abstract 1719: Differential Mcl-1 processing in evasion of DCA-induced apoptosis of colorectal cancer cells.
Authors: Delaney Leanne M. , Coomber Brenda L. 
Published: August 2014

Abstract
Recent evidence indicates that dichloroacetate (DCA) may be a cancer-specific agent that targets the unique metabolism of cancer cells, avoiding disruption of normal somatic cells. However, our laboratory has shown that some human colorectal cancer cell lines do not show the predicted response to DCA treatment, and the molecular mechanism responsible for this is currently unknown. Of interest is the Bcl-2 protein family, which consists of both pro- and anti-apoptotic members. The expression, regulation, and interactions of the Bcl-2 proteins will mediate the release of cytotoxic molecules such as cytochrome c from the mitochondria into the cytosol, activating apoptosis via a caspase cascade. Differential regulation of the Bcl-2 proteins in response to DCA treatment may indicate whether apoptosis will be induced in cancer cell lines. The human colorectal cancer cell line HCT116 was cultured and exposed to DCA as well as 5-fluorouracil, a known initiator of Bcl-2 protein-mediated apoptosis. Key changes in Bcl-2 protein expression were analyzed using immunoblotting. The expression of Mcl-1, an anti-apoptotic Bcl-2 protein, occurred at 40-kDa in all treatments, and at 28-kDa only in non-DCA treatments. PCR for the known splice variants of Mcl-1 confirmed only one gene product, suggesting the involvement of post-translational modification. The presence of cleaved caspase 3 indicates that an increase in 28-kDa Mcl-1 compared to 40-kDa Mcl-1 occurs with apoptosis in 5-fluorouracil treated cells, but does not occur in DCA-treated cells, which were not apoptotic. This suggests that Mcl-1 modification may be acting to modulate susceptibility to DCA treatment. The interactions involved in or resulting from these responses are currently under investigation. Using modified HCT116 cells without functional p53 or without functional Bax, the role of these two proteins will be emphasized. Co-immunoprecipitation of Mcl-1 will allow changes in its binding partners, such as p53, to be observed in response to DCA treatment. By utilizing mitochondrial and cytosolic fractions for protein analysis, the effect of DCA on mitochondrial localization of proteins such as Bax and the release of cytochrome c from the mitochondria will be observed. Further research may provide insight into the mechanism by which some human cancer cell lines are protected against DCA-induced cell death, and the potential role of a pathway involving Mcl-1 in this cell-specific protection.
Citation Format: Leanne M. Delaney, Brenda L. Coomber. Differential Mcl-1 processing in evasion of DCA-induced apoptosis of colorectal 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 1719. doi:10.1158/1538-7445.AM2013-1719
Abstract 1723: The BH4 domain of Bcl-2 is sufficient to induce RNA expression profile changes in human prostate cancer cell lines.
Authors: Cohen Jennifer R. , Williams Simon A. 
Published: August 2014

Abstract
Bcl-2 is the archetypal gene and first characterized member of the family bearing its name. Prostate cancer was the first solid tumor malignancy in which an elevation of cellular Bcl-2 levels was associated with advanced disease. It is thought that the anti-apoptotic activity of Bcl-2 contributes to the uniformly lethal nature of castration-resistant advanced prostate cancer. Bcl-2 is a validated target for cancer therapies. Current small molecule drug inhibitors mimic the BH3 domain of pro-apoptotic Bcl-2 family members, binding to a pocket composed mainly of Bcl-2 homology (BH) domains 1-3, and only partially BH4. Surprisingly, while these agents are effective inducers of apoptosis, they do not inhibit the oncogenic functions of the BH4 domain. The BH4 domain is essential for the antiapoptotic functions of Bcl-2, and appears to mediate interactions with proteins not part of the Bcl-2 family. This explains the small but significant body of evidence supporting an oncogenic signaling role for Bcl-2 driven by the BH4 domain. The full extent of the non-apoptotic roles of Bcl-2, including the contribution of the BH4 domain, has yet to be clarified. Our work aims to address this in prostate cancer cells, developing and utilizing a system that will implicate both the full length gene product and the BH4 domain. Eukaryotic expression constructs were designed to contain the full length Bcl-2 gene built to co-express with GFP, or a fusion gene composed of the Bcl-2 BH4 domain, GFP, and the Bcl-2 C-terminal transmembrane domain. These plasmids were then transfected into the 22Rv1, LNCaP, and LAPC4 human prostate cancer cell lines to generate stable expression clones. The clones were validated for protein expression by western blot prior to a determination of classical functionality by treatment with apoptosis-inducing agents. RNA was then isolated from the clones for expression array analysis. We successfully generated human prostate cancer cells stably overexpressing Bcl-2 and the Bcl-2 BH4 domain. These clones displayed enhanced resistance to apoptosis induction. Bcl-2 overexpression also induced expression profile changes in these clones. This was mimicked by expression of the BH4 domain alone. We have developed a useful system to help enhance our understanding of Bcl-2 by highlighting changes in RNA expression profiles induced by the gene's overexpression. We also show that the BH4 domain drives much of this function. The mechanisms responsible for these Bcl-2/BH4-induced changes warrant further investigation.
Citation Format: Jennifer R. Cohen, PhD, Simon A. Williams, PhD. The BH4 domain of Bcl-2 is sufficient to induce RNA expression profile changes in human prostate cancer cell lines. [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 1723. doi:10.1158/1538-7445.AM2013-1723