bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 364: Exercise slows tumor progression and normalizes tumor vasculature in murine models of breast cancer.
Authors: Betof Allison S. , Jones Lee W. , Dewhirst Mark W.
Published: August 2014

The effect of endurance exercise to improve post-ischemia perfusion of normal tissues is established but whether such effects extend to hypoxic solid tumors is largely uninvestigated. Thus, we evaluated the hypothesis that exercise slows tumor growth and improves the structure and function of tumor blood vessels, resulting in decreased hypoxia and increased effectiveness of cyclophosphamide chemotherapy. To investigate the effects of exercise on tumor microenvironment, we utilized voluntary wheel running after tumor cell implantation in two orthotopic models of murine breast cancer: ER(-) 4T1 breast tumor cells in BALB/c mice and ER(+) E0771 breast tumor cells in C57Bl/6 mice. Endurance exercise significantly increased microvessel density (CD31, p<0.003), vessel maturity (co-localization of NG2 and desmin with CD31, p<0.003), and perfusion (ADCperf, p<0.05), which resulted in significant reductions in intratumoral hypoxia (EF5, p<0.002). This was associated with significant inhibition of tumor growth (p<0.004), and increased apoptosis compared with sedentary controls (cleaved caspase-3, p<0.05). Next, given that hypoxia is a major cause of chemoresistance, we tested whether exercise-induced improvements in perfusion and reduction of hypoxia could improve the efficacy of conventional chemotherapy. The combination of exercise plus cyclophosphamide was associated with significantly prolonged growth delay compared with exercise or chemotherapy alone (p<0.01). In this work, we provide the first conclusive evidence that exercise may do more than decrease symptoms and improve quality of life for cancer patients. Our data suggest that exercise may be an effective adjunct therapy to reduce tumor hypoxia leading to enhanced efficacy of anticancer therapy.

Funding: ASB is supported by DOD BC093532. LWJ is supported by NIH CA143254, CA142566, CA138634, CA133895 and funds from George and Susan Beischer. MWD is supported by NIH CA40355.

Citation Format: Allison S. Betof, Lee W. Jones, Mark W. Dewhirst. Exercise slows tumor progression and normalizes tumor vasculature in murine models 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 364. doi:10.1158/1538-7445.AM2013-364
Abstract 3648: Unraveling phenotype heterogeneity in prostate cancer susceptibility in Finland utilizing covariate-based analysis.
Authors: Cropp Cheryl D. , Simpson Claire L. , Wahlfors Tiina , George Asha , Jones MaryPat S. , Harper Ursula , Ponciano-Jackson Damaris , Tammela Teuvo , Schleutker Johanna , Bailey-Wilson Joan E.
Published: August 2014

Prostate cancer is the most common male cancer in developed countries. Previously, we reported a genome-wide linkage scan in 69 Finnish Hereditary Prostate Cancer (HPC) families, which replicated the HPC9 locus on 17q21-q22 and a locus on 2q37. We used ordered subset analysis (OSA) to detect other loci linked to HPC in subsets of families to detect other loci linked to HPC incorporating mean family age of onset as a trait-related covariate to address genetic heterogeneity. The overall mean age of onset across the families was 66.2±8.8 years while the range of individual onset ages ranged from 46-98 years and age of onset varies within families. The highest OSA LOD score was 2.876 (ΔLOD p=0.02) on 15q26.2-q26.3 in a subset of 40 families ascending by age at onset, suggesting that a subset of early age at onset families may be segregating a risk allele(s) at this locus. No other ΔLOD scores were significant after permutation testing. To better capture the effect of age on the linkage signals, we used LODPAL to perform a model-free linkage analysis in affected relative pairs, while adjusting for the age of each individual family member as a single covariate. Preliminary results revealed strong evidence of linkage to HPC on chromosome 15q (LOD=4.9, 132cM) and 8q (LOD=3.1, 157cM). Future analyses are planned which will use age of onset, PSA levels and other clinical characteristics to prioritize regions which may harbor genetic variants of large effect on PRCA.

Citation Format: Cheryl D. Cropp, Claire L. Simpson, Tiina Wahlfors, Asha George, MaryPat S. Jones, Ursula Harper, Damaris Ponciano-Jackson, Teuvo Tammela, Johanna Schleutker, Joan E. Bailey-Wilson. Unraveling phenotype heterogeneity in prostate cancer susceptibility in Finland utilizing covariate-based analysis. [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 3648. doi:10.1158/1538-7445.AM2013-3648
Abstract 3651: Parity-related molecular signatures and breast cancer heterogeneity.
Authors: Rotunno Melissa , Sun Xuezheng , Figueroa Jonine , Sherman Mark , Garcia-Closas Montserrat , Meltzer Paul , Williams Tyisha , Smith Schneider Sallie , Jerry Joseph , Yang Rose , Troester Melissa
Published: August 2014

Background. Parity is an established protective factor for ER-positive but not ER-negative breast cancer and it may increase the risk of triple-negative (negative for ER, PR, and HER2) tumors. Characterizing parity-related gene expression patterns in normal breast and breast tumor tissues may improve our understanding of the biological mechanisms underlying the subtype-specific associations between parity and breast cancer risk. Method. Gene expression changes associated with parity were identified in microarray data (4x44 K Agilent) from breast tissue of 74 non-diseased reduction mammoplasty (RM) patients. This parity signature, together with published parity signatures, were compared by GSEA method with gene expression (4x44 K Agilent and Illumina arrays) from both normal (N=150) and tumor (N=208) tissues of breast cancer patients from the Polish Breast Cancer Study (PBCS), overall and by tumor ER status. Results. We identified 908 genes significantly up-regulated by parity status (parous vs. nulliparous, FDR = 0.047), including genes in inflammatory pathways. Parity-related signatures identified by us and by previously published studies were significantly enriched in normal and tumor tissue of parous PBCS patients, specifically in ER-positive tumors (FWER<0.1). Conclusions. Our analysis identified a novel parity-related gene signature in normal breast tissue from healthy women, which is also detected in normal and tumor tissues in breast cancer patients with ER-positive tumors. The lack of parity-associated signatures in ER-negative tumors may reflect the disruption of parity-associated pathways (pro-inflammatory) in ER-negative tumors.

Citation Format: Melissa Rotunno, Xuezheng Sun, Jonine Figueroa, Mark Sherman, Montserrat Garcia-Closas, Paul Meltzer, Tyisha Williams, Sallie Smith Schneider, Joseph Jerry, Rose Yang, Melissa Troester. Parity-related molecular signatures and breast cancer heterogeneity. [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 3651. doi:10.1158/1538-7445.AM2013-3651
Abstract 3655: c-JunNH2-teminal kinase 1 plays a crucial role in vitamin D-mediated cancer cellmaturation through interacting with vitamin D receptor.
Authors: Shi Qi , Bi Xiuli , Fang Wenfeng , Hu Dong , Chen Zhiguo , Dong Huali , Yang Wancai , Yang Wancai
Published: August 2014

Vitamin D is chemopreventive against colorectal carcinogenesis in vivo and in vitro. The protective effects of vitamin D against colonic carcinogenesis are most probably mediated through the vitamin D receptor (VDR). When bound to the hormonally active form of vitamin D, 1,25(OH)2-D3, VDR transactivates genes that inhibit proliferation, or promote differentiation and apoptosis. Previous studies showed that stress-activated protein kinase JNKs (c-Jun NH2-terminal kinases) and p38 cooperated to activate VDR and increase vitamin D3-dependent growth inhibition in breast cancer cells. To determine whether vitamin D-mediated maturation is associated with JNK1 and VDR in colorectal cancer cells, we treated the human colon cancer cell HT29 with 1,25(OH)2-D3, and found that 1,25(OH)2-D3 significantly inhibited cell proliferation and induced apoptosis, which was associated with induction of phosphorylated JNK1 (p-JNK1) and p21,p27, which was also associated with increased the expression of PARP and cleaved Caspase 3. In the JNK1 knockout mouse model in which tumor spontaneously formed in intestinal tract, we found that VDR was significantly reduced or not expressed in mouse intestinal epithelial cells, compared to those in the wild-type mice. Further, we found that VDR transcriptional activity was lower in JNK1-/- mouse embryonic fibroblast cells (MEFs), assayed by transfection with VDR-element-Luc reporter. When the JNK1-/- MEFs were treated with calcitriol, the induced of VDR transcriptional activity was also attenuated, compared to that in JNK1+/+ MEFs. Moreover, increasing expression of activated JNK1 by transfection with pcDNA3-Flag-MKK7 (activated JNK1) in HT29 colon cancer cells, VDR-element-Luc was significantly increased, and VDR expression levels were also increased. Finally, we co-transfected HEK239 cells with pcDNA3-HA-VDR and pcDNA3-Flag-MKK7 plasmids and conducted co-immunoprecipitation assay, we found that VDR was physically binding to JNK1. Taken together, JNK1 interacted with VDR and affected VDR at transcriptional and translational levels. Thus, the status of JNK1 may play a critical role in vitamin D-medicated cancer prevention through modulating vitamin D receptor. Whether JNK1 affects VDR polymorphisms and then influences cancer prevention efficacy of vitamin D is under further investigation.

*Supported by National Natural Science Foundation Of China (81272251)

Citation Format: Qi Shi, Xiuli Bi, Wenfeng Fang, Dong Hu, Zhiguo Chen, Huali Dong, Wancai Yang, Wancai Yang. c-JunNH2-teminal kinase 1 plays a crucial role in vitamin D-mediated cancer cellmaturation through interacting with vitamin D receptor. [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 3655. doi:10.1158/1538-7445.AM2013-3655
Abstract 3658: Sulforaphane suppresses 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse epidermal JB6 P+ cell transformation through epigenetic re-activation of Nrf2.
Authors: Su Zheng-Yuan , Shu Limin , Zhang Chengyue , Khor Tin Oo , Lee Jong Hun , Wu Tien-Yuan , Conney Allan H. , Kong Ah-Ng Tony
Published: August 2014

Sulforaphane (SFN), an isothiocyanate in cruciferous vegetables including broccoli, cabbage, cauliflower, Chinese cabbage, and watercress, has strong anti-cancer/cancer chemopreventive potentials. Transcription factor nuclear factor erythroid 2 p45 (NF-E2)-related factor 2 (Nrf2) plays an important role in regulating the expressions of cellular antioxidant and detoxification enzymes. In this study, we investigated the preventive effect of SFN on tumor promoter-induced transformation in mouse skin epidermal JB6 promotion-sensitive (JB6 P+) cells, which might be involved with the activation of Nrf2. After 5 days pre-treatment, the results showed that SFN significantly inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation. SFN enhanced nuclear translocation of Nrf2 and increased the Nrf2 downstream target enzymes including HO-1, NQO1, and UGT1A1 at both the transcriptional and protein levels. Comparing to shMock-transfected cells, TPA effectively induced colony formation in shNrf2 knockdown transfected cells were more resistant to the inhibitory effects of SFN. SFN's induction of Nrf2, HO1, and NQO1 protein expressions in shNrf2-transfected cells were lower than those in shMock-transfected cells. Epigenetics study showed that SFN suppresses methyltion ratio of the first fifteen CpGs in the promoter of Nrf2 gene in JB6 P+ cells utilizing bisulfite sequencing. Furthermore, SFN strongly reduced the protein expressions of DNA methyl transferases (DNMTs) including DNMT1, DNMT3a, and DNMT3b. In terms of histone deacetylases (HDACs), SFN not only inhibited total HDAC activity but also decreased the protein levels of HDAC1, HDAC2, HDAC3, and HDAC4, significantly. Taken together, these findings suggest that epigenetic re-activation of Nrf2 with subsequent induction of Nrf2 downstream target genes by SFN may provide insights into the chemopreventive mechanism of SFN against tumor promoter-induced mouse skin carcinogenesis.

Citation Format: Zheng-Yuan Su, Limin Shu, Chengyue Zhang, Tin Oo Khor, Jong Hun Lee, Tien-Yuan Wu, Allan H. Conney, Ah-Ng Tony Kong. Sulforaphane suppresses 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse epidermal JB6 P+ cell transformation through epigenetic re-activation of Nrf2. [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 3658. doi:10.1158/1538-7445.AM2013-3658
Abstract 3660: Apigenin suppresses IKK activation and downstream signaling leading to prostate cancer inhibition.
Authors: Shukla Sanjeev , Datt Manish , Chance Mark R. , Gupta Sanjay
Published: August 2014

Inhibitor of Nuclear Factor-κB kinase (IKK) complex is the master regulator of the NF-κB signaling pathway. IKK complex activation contributes to major cellular processes and plays a key role in the pathogenesis various human malignancies including prostate cancer. Recently, catalytic IKKs represent attractive targets for intervention with small molecule kinase inhibitors. We aimed to develop apigenin, a plant flavone, as a potent inhibitor of the IKK-kinase domain. IKK complex consist of structurally similar IKKα and IKKβ kinases. Both contains a kinase domain, a leucine-zipper motif through which the catalytic subunits dimerize, and a helix-loop-helix domain followed by a C-terminal tail that, when unphosphorylated interacts with IKKγ, the non-catalytic subunit. Screening of human prostate tumors demonstrated an increase in IKKα in low and high Gleason grade, whereas, IKKβ was higher in benign and low grade tumors. Phosphorylation of IKKα (Ser176/180) and IKKβ (Ser177/181) was significantly increased in prostate tumors compared to benign tissues. Treatment of human prostate cancer 22Rv1 and PC-3 cells to apigenin resulted in a decreased phosphorylation of IKKα/β in dose-dependent fashion, which correlated with lower proliferation and invasiveness. Ex Vivo IKK complex pull down assay using sepharose beads also confirmed direct binding of apigenin with IKK complex. In vivo studies with PC-3 and 22Rv1 xenografts in athymic nude mice further demonstrated that oral intake of apigenin at doses of 20 and 50μg/mouse/day over an 8-wk period resulted in a marked reduction in tumor growth, IKK activity, IKK phosphorylation, and NF-κB/p65 at both doses of apigenin. Furthermore, 3D structural in silico modeling analysis with PS1145, a known IKK inhibitor and apigenin were assessed for IKKα and IKKβ separately for protein-ligand docking studies using glide score. Apigenin was well anchored by hydrogen bonds with amino acid resides in the IKK complex protein at both ends. All three hydroxyl groups of apigenin were favorably oriented around different hydrogen bond acceptor atoms in the protein. Glide score generated by apigenin and PS1145 docking to IKK-α were -8.40 and -5.79, whereas IKK-β were -11.07 and -9.11; lower glide score represents better binding to IKK complex pocket. These results suggest that inhibition of cell proliferation and decrease in tumor growth by apigenin are mediated, at least in part, by its ability to suppress IKK complex and NF-κB signaling pathways.

Citation Format: Sanjeev Shukla, Manish Datt, Mark R. Chance, Sanjay Gupta. Apigenin suppresses IKK activation and downstream signaling leading to prostate cancer 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 3660. doi:10.1158/1538-7445.AM2013-3660
Abstract 3667: Pro-oxidant effects of the green tea catechin, (-)-epigallocatechin-3-gallate in oral cancer cells: A role for the mitochondria.
Authors: Tao Ling , Forester Sarah C. , Lambert Joshua D.
Published: August 2014

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea (Camellia sinensis). Many laboratory studies have demonstrated its potential cancer chemopreventive effects. Previously, we found that EGCG inhibited cell growth and induced apoptosis in oral squamous carcinoma cells (SCC-25 and SCC-9), and that, EGCG-induced intracellular ROS played a key role in the inhibitory effects. EGCG treatment also caused a significant loss of mitochondrial membrane potential after 72 h, suggesting that mitochondrial dysfunction may have caused the increased intracellular ROS. In the present study, we further explored the role of the mitochondria in EGCG-mediated oxidative stress. We found that EGCG-induced intracellular ROS initially co-localized with the mitochondria of SCC-25 cells (by 1 h) and then spread throughout the cell. Treatment with 100 μM EGCG for 24 h inhibited the activity of mitochondrial membrane complex I by 50% and tended to inhibit complex III. These results demonstrate that EGCG can induce mitochondrial dysfunction in part by impairing electron transfer chain, resulting in increased intracellular ROS. Using qPCR, we found time-dependent changes in several genes. The expressions of thyroid peroxidase (TPO, 2.9-fold), Bcl2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3, 2.2-fold) and glutathione peroxidase 2 (GPX2, 1.2-fold) were increased within 6 h treatment. The latter two genes are related to mitochondrial dysfunction and oxidative stress, respectively. By contrast to cancer cells, EGCG did not induce significant cell growth inhibition and apoptosis in normal human gingival fibroblast cells (HGF-1). EGCG treatment actually reduced intracellular ROS in HGF-1 cells in contrast to the increase observed in the cancer cell lines, indicating selective pro-oxidant effects of EGCG in oral cancer cells. In conclusion, induction of mitochondrial dysfunction and resultant production of intracellular ROS appear to play a significant role in the inhibitory effects of EGCG against oral cancer cells. The differential responses of cancer cells and normal cells to EGCG are being further studied.

Citation Format: Ling Tao, Sarah C. Forester, Joshua D. Lambert. Pro-oxidant effects of the green tea catechin, (-)-epigallocatechin-3-gallate in oral cancer cells: A role for the mitochondria. [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 3667. doi:10.1158/1538-7445.AM2013-3667
Abstract 3669: Chemoprevention of mammary and prostate cancer by phenethyl isothiocyanate in vivo is associated with suppression of vimentin protein expression.
Authors: Sakao Kozue , Hahm Eun-Ryeong , Singh Shivendra V.
Published: August 2014

Phenethyl isothiocyanate (PEITC), a constituent of many edible cruciferous vegetables (eg, watercress), exhibits in vivo preventive efficacy against cancer in rodents induced by structurally diverse chemical carcinogens. We have also shown recently that dietary administration of PEITC (3 μmol PEITC/g diet) confers significant protection against breast and prostate cancer development in MMTV-neu and TRAMP model, respectively. Prevention of prostate cancer by PEITC administration in TRAMP mice was associated with induction of E-cadherin protein expression. Because suppression of E-cadherin protein level concomitant with induction of mesenchymal markers (eg, vimentin) is a biochemical hallmark of epithelial-mesenchymal transition, a process implicated in cancer metastasis, we hypothesized that PEITC treatment was likely to suppress vimentin protein expression. Contrary to this prediction, exposure of cultured human breast (MDA-MB-231) and prostate cancer cells (PC-3 and DU145) to PEITC resulted in a dose-dependent increase in vimentin protein level, which was observed as early as 6 hours post-treatment and persisted for the duration of the experiment (24 hours). RNA interference of vimentin resulted in a modest augmentation of PEITC-mediated inhibition of MDA-MB-231 and PC-3 cell migration as well as cell viability. Furthermore, the PEITC-induced apoptosis was moderately increased upon siRNA knockdown of vimentin protein level in MDA-MB-231 and PC-3 cells. To our surprise, PEITC administration caused a marked decrease in vimentin protein expression in vivo in tumors of MMTV-neu (breast) and TRAMP mice (prostate). The results of the present study indicate that cancer chemoprevention by PEITC in vivo is associated with suppression of vimentin protein expression. The present study was supported by the grant CA101753-09 awarded by the National Cancer Institute.

Citation Format: Kozue Sakao, Eun-Ryeong Hahm, Shivendra V. Singh. Chemoprevention of mammary and prostate cancer by phenethyl isothiocyanate in vivo is associated with suppression of vimentin protein expression. [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 3669. doi:10.1158/1538-7445.AM2013-3669
Abstract 3701: Tomato carotenoids and testosterone modulate mRNA and miRNA profiles during prostate carcinogenesis.
Authors: Thomas-Ahner Jennifer M. , Wan Lei , Tan Hsueh-Li , Moran Nancy E. , Elsen Amy C. , Pearl Dennis K. , Erdman John W. , Clinton Steven K.
Published: August 2014

There is considerable evidence supporting the hypothesis that tomato carotenoids may contribute to prostate cancer prevention however the mechanisms remain uncertain. We propose that bioactive tomato components, such as lycopene, may impact testosterone signaling to inhibit prostate carcinogenesis. Four week-old C57/BL6 WT and TRAMP male mice were fed either control (AIN93G), 10% tomato powder or 0.25% lycopene beadlets. At eight weeks of age, mice were randomized among treatments: intact, castration, or castration + 2.5mg/kg testosterone repletion and animals sacrificed at 10 weeks of age. Prostate gene expression was quantified by Nanostring nCounter was used to quantify prostate gene expression with a 200 gene murine prostate carcinogenesis custom codeset and miRNA with codeset v1.1. Carotenoid analysis is by HPLC and proliferation (Ki67) by immunohistochemical evaluation. Feeding dietary tomato or lycopene increased serum lycopene, for example, in WT mice concentrations reached 335 +/- 33 nmol/L and 337 +/- 34 nmol/L in tomato and lycopene fed animals, respectively. As expected, the TRAMP genotype and testosterone stimulate proliferation with diet as a modulating factor. In the WT intact prostate, the tomato powder and lycopene diet decreased proliferation (p<0.009). The TRAMP genotype and endocrine status impacted the expression of multiple genes and miRNAs in several distinct patterns. For example, Birc5, Ki67, PCNA, BRCA1, ATM, Aurora kinase A / B, Cdc25c, Cyclin B2, cyclin E2, Fox M1,and miRs 15b, 16, 25, 200a, 200b, and 429 are increased in the TRAMP prostate, only when testosterone is present. Alternatively, TMPRSS2, CD31, CD34, Cox 2, nCad, Cyclin D1, Keratin 5, Shh, and p63, and miRs 145, 205, 328, and 423-5p are decreased in the TRAMP prostate in the presence of testosterone. Nkx3.1, miR 148a, and miR 375 are decreased upon castration whereas beta catenin, FGFR1 and TNF alpha are increased. Tomato and / or Lycopene modestly decreased expression of eCad, HIF 1 alpha, Paxillin, RxR alpha, Sca 1 and Vimentin and increased expression of CD133 and miR 22. These highly controlled in vivo studies document the strong interactions between genetic defects in the prostate, the hormonal environment, and diet in modulating early prostate carcinogenesis.

Citation Format: Jennifer M. Thomas-Ahner, Lei Wan, Hsueh-Li Tan, Nancy E. Moran, Amy C. Elsen, Dennis K. Pearl, John W. Erdman, Steven K. Clinton. Tomato carotenoids and testosterone modulate mRNA and miRNA profiles during prostate carcinogenesis. [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 3701. doi:10.1158/1538-7445.AM2013-3701
Abstract 3712: p21-activated kinase-1 in the prevention of inflammation-driven colon cancer.
Authors: Khare Vineeta , Dammann Kyle , Jambrich Manuela , Roig Andres , Shay Jerry , Gasche Christoph
Published: August 2014

Chronic gut inflammation in inflammatory bowel diseases (IBD) predisposes to the development of colorectal cancer, causing increased mortality. Use of mesalamine in the treatment and remittance of ulcerative colitis (UC) modulates the risk of neoplastic progression. We have previously reported (Khare V, et al. Biochem Pharm 2012) that p-21 activated kinase-1 (PAK1) mediates mesalamine activity by orchestrating MAPK signaling; Wnt-β catenin pathway and cell adhesion; all implicated in the colon carcinogenesis. Since mesalamine has primarily an anti-inflammatory function, we evaluated the role of PAK1, its target, in IBD and in colitis-associated cancer (CAC). PAK1 expression was scored by immunohistochemistry in human samples from IBD, CAC and normal mucosa. Compared to normal mucosa and Crohn's disease, a higher PAK1 expression was detected in UC which further increased in CAC. PAK1 expression was also elevated in the inflamed mucosa and carcinomas in IL-10−/− mouse model of colitis. The efficacy of mesalamine in reducing inflammation and tumor incidence in these mice has been previously reported (Brown JB et al, Gastroenetrology 2010). The consequence of PAK1 overexpression was further investigated in vitro. Normal diploid colon epithelial cells (HCEC-1CT) showed higher proliferation (46 ± 3.1% increase) upon overexpression of wildtype (wt) PAK1 while dominant negative (dn) PAK1 overexpression reduced proliferation (25% ± 2.5 decrease) compared to control. Apoptosis (Annexin V staining) was reduced in HCEC-1CT overexpressing wtPAK1 (1.2% ± 0.40) compared to dnPAK1 (11.6% ± 0.3) and control (16% ± 0.83). Mesalamine treatment (20mM) was effective in counteracting the effect of PAK1 overexpression by reducing cell proliferation and inducing apoptosis. Treatment of cells with specific inhibitors (PD98059/LY294002/Rapamycin) of signaling pathways (MEK/PI3K/mTOR) demonstrated that mesalamine regulated PAK1 expression by the MEK, PI3K and mTOR signaling pathways. Our data indicate that (1) PAK1 is upregulated in UC and in CAC, (2) PAK1 may be utilized as a predictive marker for the development of CAC, and (3) PAK1 is a viable target for chemoprevention in the setting of colitis. Mesalamine counteracts PAK1 expression and its effect on cell proliferation and apoptosis. In the longterm management of UC mesalamine may protect from CAC through inhibition of PAK1.

Citation Format: Vineeta Khare, Kyle Dammann, Manuela Jambrich, Andres Roig, Jerry Shay, Christoph Gasche. p21-activated kinase-1 in the prevention of inflammation-driven colon 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 3712. doi:10.1158/1538-7445.AM2013-3712
Abstract 3719: xCT inhibition suppresses CD44v-positive stem-like tumor cells, which are resistant to EGFR-targeted therapy in head and neck squamous cell carcinoma.
Authors: Yoshitake Momoko , Nagano Osamu , Nakagawa Taneaki , Saya Hideyuki
Published: August 2014

Given that cancer cells are exposed to environmental stressors such as oxygen or nutrient deficiency, low pH, inflammatory mediators, and ROS during tumor progression,the ability to avoid the consequences of such exposure is required for cancer cell survival. CD44 is a major marker for stem-like cancer cells in many epithelial tumors and has been implicated in tumor growth, invasion, and metastasis. CD44 exists in numerous variant isoforms (CD44v) that are generated through alternative mRNA splicing. We recently showed that interaction of CD44v with the cystine transporter subunit xCT stabilizes the latter protein and thereby potentiates the ability of cancer cells to defend themselves against reactive oxygen species (ROS). Stem-like cancer cells in which defense against ROS is enhanced by CD44v are thus thought to drive tumor growth, chemoresistance and metastasis.

In the present study, we show that head and neck squamous cell carcinoma (HNSCC) cells that express CD44v rely on the activity of the cystine transporter subunit xCT for control of their redox status. Ablation of CD44v attenuated the xCT dependency as well as tumor-forming ability in HNSCC cells, and xCT inhibition selectively induced apoptosis in CD44v-expressing tumor cells. In contrast, CD44v-negative differentiated cells manifest epidermal growth factor receptor (EGFR) activation and rely largely on EGFR activity for their survival. Combined treatment with inhibitors of xCT-dependent cystine transport and of EGFR may induce apoptosis in distinct subpopulations of HNSCC tumor cells.

Citation Format: Momoko Yoshitake, Osamu Nagano, Taneaki Nakagawa, Hideyuki Saya. xCT inhibition suppresses CD44v-positive stem-like tumor cells, which are resistant to EGFR-targeted therapy in head and neck squamous 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 3719. doi:10.1158/1538-7445.AM2013-3719
Abstract 3722: HH/GLI signaling as a new therapeutic target governs the stemness of head and neck cancer stem cells.
Authors: Yan Ming
Published: August 2014

Patients with advanced head and neck squamous cell carcinoma (HNSCC) show poor prognosis to current therapy and tumor recurrence and metastasis are frequently observed. The discovery of cancer stem cell (CSC) markers is crucial for developing novel therapeutic strategies by targeting these CSCs. To address this issue, we used sphere culture method to enrich CSCs from their isogeneic adherent cultured HNSCC cells. Compared with adherent cultured HNSCC cells, the microspheres of HNSCC cells were more clonogenic in nude mice, and expressed higher levels of shh and Gli-2, and Gli-2 translocated into the nuclear of the spheres, which showed that hedgehog signal pathway was activated in the cancer stem cells like subpopulations of HNSCC. Further study found that Gli-2, one of the main transcriptional activators of HH/GLI signal, was expressed in 60 (44%) of the 136 HNSCC samples and the expression was significantly associated with poor clinical outcomes. Only 44% of the patients whose tumors expressed Gli-2 survived at 5 years after surgery compared to 77% of those whose tumors lacked the Gli-2 expression (P < 0.0001). Both cyclopamine and GANT61 effectively inhibited Gli expression, slowed cell growth, promoted G1 arrest, increased apoptosis and inhibited migration of HNSCC cells. Together with the findings, we conclude that activation of HH/GLI pathway plays an important role in maintaining the stemness of HNSCC, and strongly associates with HNSCC progression, suggesting that a subset of OSCC patients may benefit from anti-HH/GLI therapies.

Citation Format: Ming Yan. HH/GLI signaling as a new therapeutic target governs the stemness of head and neck cancer stem 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 3722. doi:10.1158/1538-7445.AM2013-3722
Abstract 3723: Tangeretin enhances sensitivity of human pancreatic cancer cells to gemcitabine through targeting the reprogramming of stemness.
Authors: Haque Inamul , Banerjee Sushanta K. , Banerjee Snigdha
Published: August 2014

Background: As a single agent, gemcitabine (2′,2′-difluorodeoxycytidine) has shown only a modest improvement in survival in patients with pancreatic ductal adenocarcinoma (PDAC). Our recent studies found CCN1 (a member of CCN family of growth factor) as an important factor in determining PDAC aggressiveness as it promotes epithelial to mesenchymal transition, tumor stemness, migration and tumorigenicity in xenograft model, possibly through the regulation of multiple miRNAs that are known to link with the progression of cancers and survival and the maintenance of cancer stem cells. Targeting CCN1 may lead to the development of novel therapeutic approaches for human cancers. Here, we examined the effects of tangeretin, a polymethoxylated flavonoid compound produced by citrus fruits in combination of gemcitabine on CCN1-sonic hedgehog (SHh) signaling in pancreatic cancer cells, and assessed the therapeutic potential of tangeretin with gemcitabine for the treatment and/or prevention of pancreatic cancer.

Methodology/Principal Findings: Cell viability and apoptosis were measured by crystal violet staining assay and annexinV/PI staining assay, respectively. Gene and protein expressions were measured by Western blot analysis, respectively. We found that tangeretin in combination with gemcitabine significantly decreased cell survival, clonogenicity, wound-healing capacity, sphere-forming capacity (pancreatospheres) in pancreatic cell lines. Tangeretin also decreased the expression of cancer stem cells (CSC) markers, CD44, Notch-1, Nanog, Oct-4, ABCG2, SHh and CCN1.

Conclusions: Collectively, these studies clearly suggest that tangeretin helps in sensitizing pancreatic cancer cells to gemcitabine by reprogramming the CSC-specific markers. Thus tangeretin could be useful for overcoming therapeutic resistance of pancreatic cancer cells.

Citation Format: Inamul Haque, Sushanta K. Banerjee, Snigdha Banerjee. Tangeretin enhances sensitivity of human pancreatic cancer cells to gemcitabine through targeting the reprogramming of stemness. [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 3723. doi:10.1158/1538-7445.AM2013-3723
Abstract 3740: Temozolomide-perillyl alcohol conjugate is cytotoxic for glioma cancer stem cells.
Authors: Jhaveri Niyati , Agasse Fabienne , Hofman Florence M. , Chen Thomas C.
Published: August 2014

Glioblastoma multiforme (GBM), the most malignant glioma, is a highly invasive tumor which is usually fatal within 2 years. The chemotherapeutic agent of choice is temozolomide (TMZ); however glioma patients inevitably become resistant to TMZ and tumors recur. Tumor recurrence has been associated with highly invasive, chemoresistant cancer stem cells (CSC) which is resistant to TMZ. We have constructed a new chemical entity by conjugating TMZ to perillyl alcohol (POH) via a carbamate bond. This compound, TMZ-POH, contains POH, a naturally occurring monoterpene that reduces tumor cell migration and has anti-tumor properties against gliomas as well as other cancers. In the studies presented here we demonstrate that TMZ-POH is cytotoxic to CSCs without affecting normal stem cells. The mechanism of TMZ-POH induced cytotoxicity is mediated in part through the DNA damage response pathway and apoptosis. Furthermore, the TMZ-POH conjugate is 5 to 10 fold more effective in inducing cell death compared to TMZ, POH or the mixture of these agents. Our data show that TMZ-POH is a promising novel compound directed against cancer stem cells and therefore important for the treatment of drug resistant, recurrent gliomas.

Citation Format: Niyati Jhaveri, Fabienne Agasse, Florence M. Hofman, Thomas C. Chen. Temozolomide-perillyl alcohol conjugate is cytotoxic for glioma cancer stem 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 3740. doi:10.1158/1538-7445.AM2013-3740
Abstract 3742: Targeting the stem cell factor HMGA2 to improve outcomes in glioblastoma.
Authors: Kaur Harpreet , Hutt Marianne , Mao Xing-gang , Eberhart Charles G. , Raabe Eric H.
Published: August 2014

Glioblastoma Multiforme (GBM) causes the majority of brain tumor-related deaths in the United States. The high invasiveness of GBM prevents complete surgical resection, allowing tumor recurrence. The lack of curative treatment highlights a dire need to develop specific targeted therapeutics. Identifying and targeting novel molecular markers in glioma stem-like cells (GSCs), one of the major causes of tumor invasion and recurrence, could lead to development of better therapies. HMGA2, a non-histone transcriptional modulator, is a regulator of normal and cancer stem cells. The significance of HMGA2 as a potential therapeutic target in GBM has not been investigated. To elucidate the role of HMGA2 in GBM, we have used a combination of in vitro and in vivo techniques in the present study. We found high expression of HMGA2 mRNA and protein in a subset of primary brain tumor samples from GBM patients, GBM cell lines and GBM stem-cell lines using quantitative real-time PCR and immunoblotting. Short hairpin RNA (shRNA)-mediated reduction of HMGA2 significantly inhibited invasion of GBM cell lines (U-87 MG and LN-229, 32 and 70% inhibition, respectively, with HMGA2 shRNA vs. control shRNA, P<0.001) and GBM stem cell lines (040821, 62% inhibition with HMGA2 shRNA vs. control shRNA, P<0.001) through Matrigel in vitro by transwell invasion assays. Conversely, overexpression of HMGA2 in GBM stem cell lines increased invasion (130% increase with HMGA2 overexpression vs. control vector, P<0.0001) through Matrigel in vitro as demonstrated by transwell invasion assays. In addition, overexpression of HMGA2 increased clonogenicity of GBM stem cell lines in vitro in soft agar and methylcellulose clonogenic assays (40% increase with HMGA2 overexpression vs. control vector, P<0.0001). Importantly, Kaplan-Meier analysis showed increased survival of mice injected with GBM stem cell lines transduced with HMGA2 shRNA compared to control shRNA (P<0.05) in an in vivo, orthotopic, intracranial mouse xenograft model. Together, our results suggest the importance of HMGA2 in promoting tumorigenicity of GBM by increasing invasiveness and a stem-like state, thereby suggesting that HMGA2 is a potential therapeutic target in GBM. Future studies are aimed at elucidating the molecular mechanism by which HMGA2 regulates invasion and stemness in GBM.

Citation Format: Harpreet Kaur, Marianne Hutt, Xing-gang Mao, Charles G. Eberhart, Eric H. Raabe. Targeting the stem cell factor HMGA2 to improve outcomes 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 3742. doi:10.1158/1538-7445.AM2013-3742
Abstract 3744: G-CSF-dependent regulation of STAT3 in neuroblastoma cancer stem cell subpopulations.
Authors: Agarwal Saurabh , Chen Zaowen , Hsu Danielle , Kim Eugene , Shohet Jason M.
Published: August 2014

Neuroblastoma is a neural crest derived malignancy arising form peripheral sympathetic nervous system of infants and young children. We have recently defined a highly tumorigenic sub-population of neuroblastoma cells based on surface expression of CD114 (the G-CSF receptor, CSF3R). These cells meet the operational criteria for cancer stem cells based on their self-renewal, differentiation and lineage restricted tumorigenicity, and can be isolated directly from primary tumor biopsy specimens. As STAT3 activation is a canonical downstream event of G-CSF receptor ligation, is critical for neuronal specification, and is implicated in cancer stem cell maintenance, we hypothesized that inhibition of the STAT3 pathway may functionally inhibit the cancer stem cell-like neuroblastoma subpopulation. We used pathway-specific qPCR arrays to evaluate differential gene expression in CD114+ and CD114- tumor subpopulations. As predicted, STAT3 target genes were up-regulated in the CD114+ stem cell-like population. In addition, critical genes controlling early neural crest specification, cell cycle progression, self-renewal, and maintenance of pluripotency were up-regulated in CD114+ population while markers of mature mesenchymal neural crest were increased in CD114- population. Treatment of Neuroblastoma cell lines with G-CSF increased both CD114 expression and STAT3 transcriptional activation in a dose and time dependent manner. Phospho-flow analysis confirmed STAT3 phosphorylation (Y705) in response to exogenous G-CSF. The addition of a STAT3 inhibitor which prevents phosphorylation and dimerization of STAT3 (Stattic), specifically abrogated the effect of exogenous G-CSF treatment. Finally, we identified putative STAT3 binding sites within the 5’UTR of the CSF3R gene and confirmed binding of STAT3 and pSTAT3 using chromatin immunoprecipitation analysis (ChIP-qPCR). We demonstrate significant enrichment of binding in response to exogenous G-CSF within CD114 receptor positive subpopulation in contrast to CD114- population. These data support a model for a positive-feedback loop where G-CSF triggers STAT3 dependent up-regulation of the G-CSF receptor, further sensitizing these cells to exogenous ligand, promoting STAT3 transcriptional activation, and contributing to stem cell maintenance. Our data support further evaluation of the potential clinical role for specific STAT3 inhibitors as anti-cancer stem cell therapy in neuroblastoma.

Citation Format: Saurabh Agarwal, Zaowen Chen, Danielle Hsu, Eugene Kim, Jason M. Shohet. G-CSF-dependent regulation of STAT3 in neuroblastoma cancer stem cell subpopulations. [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 3744. doi:10.1158/1538-7445.AM2013-3744
Abstract 3746: Association with the sonic hedgehog pathway between gastric cancer stem cells.
Authors: Sung Jae Sook , Lee Jong Won , Jo Ukhyun , Kim Yeul Hong
Published: August 2014

Cancer stem cells (CSCs) have been hypothesized to drive the growth, metastasis and chemoresistance capacity. Activation of sonic hedgehog (SHH) signaling has been implicated in progression of variety of tumors. In this study, we investigated potentiality that activation of the SHH pathway maintained the characteristics of gastric CSCs. First, we establish spheres culture system from 5 human gastric cancer cells and identified spheres from 3 gastric CSCs (MKN45, SNU638, SNU601). Compared with parent cells, spheres had more self-renewing capacity and multipotent capacity. Gastric cancer spheres shown that increased expression of stem cell markers (Oct4 and Nanog) and decreased epithelial maker (Cytokeratin 18). However, expressions of CSCs markers (CD44, CD24, CD54 and CD133) were not significantly. Spheres showed more CSCs characteristics, such as more colony formation and more resistance to conventional chemotherapeutic drugs (5-FU, cisplatin and paclitaxel) compared to parent cells. Next, western blot showed that the expression levels of SHH related pathway (Ptch, Smo and Gli1) were significantly higher in spheres than in parent cells. Further analysis, we found that SHH pathway blocked by cyclopamine enhanced the efficacy of chemotherapeutic drugs in spheres. In the further study, we will confirm SHH dependence and in vivo xenograft study. In conclusion, our data suggest that sonic hedgehog blockade could improve the antitumor efficacy of chemotherapy of human gastric cancer. [This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. A010250)]

Citation Format: Jae Sook Sung, Jong Won Lee, Ukhyun Jo, Yeul Hong Kim. Association with the sonic hedgehog pathway between gastric cancer stem 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 3746. doi:10.1158/1538-7445.AM2013-3746
Abstract 3754: Methionine adenosyltransferase IIα regulates histone methyltransferase G9a expression in colorectal cancer stem cells.
Authors: Li Kai-Chun , Cha Shih-Ting , Chu Chia-Yu , Kuo Min-Liang
Published: August 2014

Histone modification is critical for regulation of chromatin structure and gene transcription in cells and recent evidences have characterized that histone methylation may contribute to tumorigenesis and cancer malignancies. In general, the methyl donor for methylation is synthesized from S-adenosylmethionine (SAM), in a reaction catalyzed from methionine by methionine adenosyltransferase (MAT). Our previous studies have demonstrated the expression of histone methyltransferase G9a, which is responsible for histone H3 lysine 9 methylation, not only correlates to tumor aggressiveness but also plays a crucial role in regulation of colorectal cancer stem cells (CSCs), which endow high tumorigenecity, drive metastasis and therapy-resistance. We discover that G9a is enriched in CSCs and knockdown of its expression will promote differentiation, inhibit drug-resistance and metastatic ability of CSCs. Here, we further report that MATIIα expression is specifically elevated in the nucleus and interacts with G9a in CSCs. Overexpression of MATIIα in non-CSCs will increase G9a expression, self-renewal ability and stemness marker expression. In contrast, knockdown of MATIIα decreases G9a expression, it reveals that the self-renewal ability will be blocked in CSCs. Furthermore, inhibition of MATIIα expression by its inhibitor, SAM, can also decrease G9a expression and stem-cell like characteristics. Taken together, we first demonstrate that the expression and the function of G9a are both maintained by MATIIα in colorectal CSCs. These findings provide a new insight into understanding of the link between the metabolic enzyme and epigenetic regulator in CSCs, which may be a therapeutic target in the future.

Citation Format: Kai-Chun Li, Shih-Ting Cha, Chia-Yu Chu, Min-Liang Kuo. Methionine adenosyltransferase IIα regulates histone methyltransferase G9a expression in colorectal cancer stem 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 3754. doi:10.1158/1538-7445.AM2013-3754