bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1280: Pterostilbene exerts full protection against UVB-induced skin carcinogenesis.
Authors: Ortega Angel , Rodriguez Maria L. , Sirerol Joan A. , Pulido Ines , Crespo Daniel , Carretero Julian , Asensi Miguel A. , Mena Salvador , Estrela Jose M.
Published: August 2014

Epidemiological, clinical and laboratory studies have demonstrated that solar ultraviolet (UV) radiation is the main cause of nonmelanoma skin cancer (i.e., basal cell and squamous cell carcinoma) and it is also a prime factor in the etiology of cutaneous melanoma. The cancer-causing effects of solar exposure on the skin are mainly produced by UV-B radiation in the 290- to 320-nm range, the same range that produces burning in human skin (erythema), inflammation, oxidative stress, DNA damage, etc. Thus, and considering the alarming numbers of skin cancers being diagnosed around the world, it is increasingly evident the need of an effective protection against UV radiation. Polyphenols (PFs) are abundant in many fruits and vegetables, wine, tea, and various dietary supplements. The role of these natural molecules as potential anticarcinogens and photoprotectors has been postulated (e.g. Clifford JL & DiGiovanni J. Cancer Prev Res 3: 132-5, 2010). Resveratrol (trans-3,5,4′-trihydroxystilbene; RES) is a phytoalexin present in a wide variety of plant species, where its synthesis is induced by stress conditions. The cancer chemopreventive activity of RES was first reported by Jang et al [Science 275, 218 - 220 (1997)] in a model of skin carcinogenesis where topic administration of this polyphenol inhibited multistage mouse skin carcinogenesis. Equally promising action is exerted by resveratrol analogues, mainly pterostilbene (3,5-dimethoxy-4′-hydroxy-transstilbene: PTER), which shows a higher half-life and more potent anticancer effects in vivo than RES. The long-term UV-B administration (180 mJ/cm2; 3 doses/week; for a total of 30 weeks) reproduces, in an animal model, which are the consequences in humans of receiving chronic UV-B radiations. We observed that pretreatment of the skin with PTER prevented UV-B-induced skin tumorigenesis (∼90 % of tumor free-mice at the end of treatment, n=20; P<0.01). Our aim was to study the key molecular mechanisms involved in this strong anticancer effect elicited by PTER. Our results indicate that PTER efficiently avoid skin carcinogenesis induced by solar radiation by decreasing DNA mutagenesis, and protein and lipid oxidation.

Citation Format: Angel Ortega, Maria L. Rodriguez, Joan A. Sirerol, Ines Pulido, Daniel Crespo, Julian Carretero, Miguel A. Asensi, Salvador Mena, Jose M. Estrela. Pterostilbene exerts full protection against UVB-induced skin 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 1280. doi:10.1158/1538-7445.AM2013-1280
Abstract 1285: Smad4 loss leads to reduced DNA repair and skin cancer.
Authors: Mitra Doyel , Fernandez Pamela , Li Bian , Song Ningjing , Han Gangwen , Wang Xiao-Jing
Published: August 2014

Solar ultraviolet (UV) radiation is the primary cause of skin cancer. Non-melanoma skin cancer, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is the most common form of skin cancer and accounts for 2-3 million worldwide cases of cancer each year. The transcription factor Smad4 is a central mediator in the transforming growth factor β (TGFβ), activin, and bone morphogenetic protein (BMP) signaling pathways. Smad4 loss occurs frequently in human skin squamous cell carcinoma (SCC), but it is unknown if this event is causal to ultraviolet-induced (UV) carcinogenesis, a major etiological factor in human skin cancer. In the present study, we exposed mice with keratinocyte-specific Smad4 deletion (K14.Smad4−/−) and wildtype (WT) mice to chronic UV irradiation. Compared to WT littermates, K14.Smad4−/− mice exhibited increased susceptibility to UV-induced skin cancer. Histological examination revealed that UV-induced Smad4−/− tumors were all SCCs. Moreover K14.Smad4−/− skin shows increased DNA damage due to reduced expression of DNA repair genes compared to WT skin. We have identified a novel mechanism by which Smad4 suppresses skin cancer by promoting repair of UV-induced DNA lesions.

Citation Format: Doyel Mitra, Pamela Fernandez, Bian Li, Ningjing Song, Gangwen Han, Xiao-Jing Wang. Smad4 loss leads to reduced DNA repair and skin 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 1285. doi:10.1158/1538-7445.AM2013-1285
Abstract 1289: Role of deregulation of Pol III-dependent transcription in phenotypic alteration.
Authors: Zhong Shuping , Zhang Qingsong , Shi Ganggang
Published: August 2014

The products of RNA polymerase III (Pol III)-dependent genes, such as tRNAs and 5S rRNA, are elevated in both transformed and tumor cells suggesting that they play a crucial role in tumorigenesis. An increase in Brf1 (TFIIIB-related factor 1), a subunit of TFIIIB in Pol III transcription machinery, augments Pol III gene transcription and is sufficient for cell transformation and tumor formation (1). We have demonstrated, for the first time, that enhancement of Brf1 expression and Pol III gene transcription are correlated to liver tumor formation in mice (2). This implies that Brf1 may be a key molecule during liver tumor development. Our early study demonstrated that MSK1 (mitogen- and stress-activated protein kinase 1) mediates H3S28ph (3), Our recent study have indicated that reduction of H3S28ph (histone H3 phosphorylation at serine 28) results in repression of Brf1 and Pol III gene transcription (4). Blocking MSK1 inhibits cell transformation (5) and tumor formation (6). To further determine the role of Brf1 and the signaling and epigenetic regulating events in phenotypic alteration induced by DEN (diethylnitrosamine) which is a chemical carcinogen and is used to induce liver tumor (7), we utilized DEN (200μg/ml) to treat AML-12 cells, an immortalized mouse hepatocyte line to extract cell lysates and total RNA. Our results indicate that DEN treatment increased Brf1 expression and Pol III gene, tRNALeu and 5S rRNA, transcription. DEN strongly induced phosphorylation of MSK1 at serine 376 and Threonine 581. DEN also induces H3phs at both H3S10ph and H3S28ph in AML-12 cells. Interestingly, DEN-induced H3ph in tumor stem cells of mouse liver is significantly stronger than in non-tumor AML-12 cells. MSK1 chemical inhibitor, H89 decreased the induction of Pol III genes. DEN increased the rate of AML-12 cell proliferation. Furthermore, DEN induced colony formation of AML-12 cells in soft agar. Repression of Brf1 by its siRNA reduced Pol III gene transcription and inhibited the cell transformation by DEN. Taken together, these results demonstrate that DEN activates MSK1 and induces H3ph, which in turn mediate Brf1 expression to upregulate RNA Pol III transcription, resulting in increasing in cell proliferation and cell transformation. These studies will allow us to further uncover a novel molecular mechanism of hepatocellular carcinoma by using MSK KO mice and conditional Brf1 KO mice.

[This project was supported by NIH grant AA017288 and AA021114 to Shuping Zhong.]

Citation Format: Shuping Zhong, Qingsong Zhang, Ganggang Shi. Role of deregulation of Pol III-dependent transcription in phenotypic alteration. [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 1289. doi:10.1158/1538-7445.AM2013-1289
Abstract 129: Race-specific social gradients in breast cancer burden in Maryland: 1992-2003.
Authors: Klassen Ann C. , Pankiewicz Aaron , Curriero Frank
Published: August 2014

There is substantial evidence linking adverse breast cancer characteristics, including more aggressive histology, larger tumor size, and advanced stage at diagnosis, to both African American race, and lower social class. However, it is not well known if social class affects black and white women similarly, and what behavioral or environmental factors may contribute to the social class gradient for each racial group.

Using data from approximately 55,000 cases of breast cancer reported to the Maryland Cancer Registry between 1992-2003, we used multi-level random effects models to examine the relationship between case race, age, year of diagnosis, area-level social class indices (area-level rates of high school graduation, employment, white collar work, and income) and three characteristics associated with adverse cancer outcomes: SEER stage at diagnosis (stage 2-7 versus 1), large tumor size at diagnosis (>2 cm versus <=2 cm), and aggressive histological grade of tumor (grade 3 or 4, versus 1 or 2). We then examined the additional contribution to the model of an estimate of area-level smoking behavior, using estimates of area-level average per household tobacco spending. Finally, we examined whether effects of social class and tobacco use varied for white and black women.

Results demonstrate that black women were more likely to be diagnosed with later stage cancers (O.R. =1.29, 95% C.I.= 1.22,1.35), larger tumors (O.R.= 1.45, 95% C.I.= 1.34, 1.56), and more aggressive tumor histology (O.R. 1.65, 95% C.I.= 1.56,1.74). Social class was protective for all three outcomes, but statistically significant interactions showed that this protective effect of social class was reduced for black women compared to white women. In addition, each $1000 increase in average household level of tobacco spending was significantly associated with aggressive grade (O.R.=1.01 per $1000) and larger tumor size (O.R. =1.03, 95% C.I.=1.01,1.06) but not significantly associated with late stage diagnosis. There were no statistically significant interactions of tobacco spending by race, indicating that the effect of tobacco spending are similar for black and white cases.

Findings suggest that social class effects differ by race, and that intersectionality - the context-based understanding of multiple simultaneous social effects on health - may be an important approach to understanding excess breast cancer burden in women. This analysis also suggests that health risk behaviors, such as group-level tobacco use, may contribute additional risk, and should be further explored with more robust designs and data.

Citation Format: Ann C. Klassen, Aaron Pankiewicz, Frank Curriero. Race-specific social gradients in breast cancer burden in Maryland: 1992-2003. [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 129. doi:10.1158/1538-7445.AM2013-129
Abstract 1294: Identification of the binding domains that allow ligand-independent co-activation of androgen receptor by Gli2.
Authors: Li Na , Chen Mengqian , Buttyan Ralph
Published: August 2014

Gli proteins are transcription factors that mediate the cellular response to Hedgehog signaling. Gli activity guides cell fate decisions during development and is required for the proper morphogenesis of embryonic tissues, including the prostate gland. Previously, we showed that exogenous overexpression of Gli1 or Gli2 in androgen-deprived LNCaP cells increased the expressions of androgen-dependent genes in prostate cancer (PCa) cells and conferred androgen-independent growth behavior to them (Chen et al., Mol Cancer, 9: 89-101, 2010). We also showed that Gli1 or Gli2 proteins co-immunoprecipitate with AR, suggesting that AR interacts with Gli proteins to mediate these effects. Based upon this data, we proposed that Gli1/2 proteins are ligand-independent co-activators of AR in PCa. To better understand the Gli2-AR interaction and its effects on PCa responsiveness to androgen ablation, we fine mapped the specific interaction domains between Gli2 and AR. Complete or partial recombinant Gli2 cDNAs were tagged with GST and the GST-tagged proteins were purified on glutathione beads prior to incubation with in vitro translated human AR protein fragments. GST pulldown assays showed that GLI2 specifically recognizes and binds the Tau5 region within the AR N-terminal domain (AA 391-555). Likewise, AR binds to Gli2 within an extended

C-terminal domain (AA 628-1091) that may involve two distinct AR binding sites. AR co-activation studies in 293T cells shows that the presence of binding site(s) and the Gli2 activation domain are required for Gli2 co-activation of AR. Gli2 was tested for its ability to co-activate natural truncated variants of the AR. The interaction of Gli2 with the Tau4 domain of AR was consistent with the ability of Gli2 to co-activate truncated variants of the AR that lack the DNA binding domain.

Our work demonstrates that Gli2 co-activation of AR requires direct interaction between the tau5 domain in the AR N-terminus and the AR binding domains in the Gli2 C-terminus as well as the Gli2 activation domain. Gli2 binding at tau5 supports co-activation of the wildtype AR (in both the presence and absence of androgen) as well as co-activation of truncated receptors that do not bind androgens. As such, the evidence that Gli2 expression is increased in PCa by androgen ablation suggests that it may be a factor in progression to castration resistant PCa.

Supported by the DOD PCRP (W81XH-10-1-0493, to RB).

Citation Format: Na Li, Mengqian Chen, Ralph Buttyan. Identification of the binding domains that allow ligand-independent co-activation of androgen receptor by Gli2. [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 1294. doi:10.1158/1538-7445.AM2013-1294
Abstract 1297: SETD6-mediated deregulation of NF- κB signaling in 4-ABP-induced bladder carcinogenesis.
Authors: Mukherjee Neelam , Ghosh Rita
Published: August 2014

Epidemiological data support an etiological role for chemicals from occupational exposure and cigarette smoke with increased risk of bladder cancer. However, epigenetic effects of these chemicals remain to be elucidated. Protein methyltransferases (PMTs) methylate protein lysine and arginine residues and play an important role in regulating gene transcription. Deregulation of SET-domain-containing PMTs has a crucial role in carcinogenesis. SETD6 has been shown to monomethylate RelA (a principal subunit of NF-κB at Lys310). Monomethylated RelA recruits GLP (G9A-like protein), a histone dimethyl transferase to the NF-κB target genes, which results in transcriptional repression. The role of SETD6 in bladder cancer is unknown. We used qPCR and immunoblotting to determine changes in SETD6 at the mRNA and protein level in bladder cancer cells relative to primary urothelial cells. We also found that knockdown of SETD6 significantly decreases the viability and proliferation of bladder cancer cells suggesting that SETD6 may function as an oncogene in bladder cancer. Furthermore, we also found that message and protein levels of SETD6 are induced in primary urothelial cells following treatment of 4-aminobiphenyl (4-ABP), an important constituent of cigarette smoke. Preliminary results indicate that induction may be mediated by 4-ABP-induced ROS. RelAK310Me1 level also increased with 4-ABP treatment showing the increase in SETD6 functional activity with 4-ABP exposure. We also found the decrease in expression of RelB, one of the target genes of RelA. Overall our results show that SETD6 may function as an oncogene in 4-ABP induced bladder cancer by deregulating transactivation property of RelA. These results show for the first time the relevance of PKMTs and epigenetic regulation of NF-κB in carcinogen induced bladder cancer. Supported by RO3 CA136058 (RG).

Citation Format: Neelam Mukherjee, Rita Ghosh. SETD6-mediated deregulation of NF- κB signaling in 4-ABP-induced bladder 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 1297. doi:10.1158/1538-7445.AM2013-1297
Abstract 1301: Metformin induces cytotoxicity by TP and ERCC1 decrease.
Authors: Lin Yun-Wei , Huang Yu-Ching , Tseng Sheng-Chieh , Chiu Hsien-Chun , Chen Huang-Jen , Huang Yi-Jhen , Wo Ting-Yu , Weng Shao-Hsing , Ko Jen-Chung
Published: August 2014

Metformin is an anti-diabetic drug recently shown to inhibit cancer cell proliferation and growth, although the involved molecular mechanisms have not been elucidated. In many cancer cells, highly expression of thymidine phosphorylase (TP) and ERCC1 are associated with poor prognosis. We used A549 and H1975 huamn non-small cell lung cancer (NSCLC) cell lines to investigate the role of TP and ERCC1 expression in metformin-induced cytotoxicity. Metformin treatment decreased cellular TP and ERCC1 protein and mRNA levels by down-regulating phosphorylated MEK1/2-ERK1/2 protein levels in a dose- and time-dependent manner. The enforced expression of the constitutively active MEK1 (MEK1-CA) vectors significantly restored cellular TP and ERCC1 protein levels and cells viability. Specific inhibition of TP and ERCC1 expression by siRNA enhanced the metformin-induced cytotoxicity and growth inhibition. In conclusion, metformin induces cytotoxicity by down-regulating TP and ERCC1 expression in NSCLC cells.

Citation Format: Yun-Wei Lin, Yu-Ching Huang, Sheng-Chieh Tseng, Hsien-Chun Chiu, Huang-Jen Chen, Yi-Jhen Huang, Ting-Yu Wo, Shao-Hsing Weng, Jen-Chung Ko. Metformin induces cytotoxicity by TP and ERCC1 decrease. [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 1301. doi:10.1158/1538-7445.AM2013-1301
Abstract 1302: Targeting mTORC1 by epidermal overexpression of PRAS40(T246A) suppresses TPA-induced epidermal hyperplasia during tumor promotion.
Authors: Rho Okkyung , DiGiovanni John
Published: August 2014

Akt activation is an important event during the early stages of skin tumor promotion by diverse tumor promoting stimuli. Transgenic mice overexpressing either wild-type Akt1 (Aktwt) or a constitutively active form of Akt1 (Aktmyr) exhibit dramatically enhanced susceptibility to two-stage skin carcinogenesis and skin tumor promotion. Several downstream Akt targets are modulated (i.e., increased phosphorylation) in keratinocytes during tumor promotion, including the mammalian target of rapamycin (mTORC1). Recent experiments show that inhibiting mTORC1 by using topical rapamycin in both wild-type and BK5.Aktwt transgenic mice can effectively block TPA-induced activation of mTORC1 signaling, epidermal hyperproliferation and skin tumor promotion in a dose-dependent manner. Treatment with rapamycin also inhibited TPA-induced proliferation and migration of labeling retaining cells (LRCs) of the bulge region from the hair follicles to upper epidermal compartments. To further examine the importance of mTORC1 signaling in epithelial carcinogenesis, we generated BK5.PRAS40mt (PRAS40T246A) mice using the BK5 vector that targets expression to the basal layer of epidermis. PRAS40 was originally identified as a novel Akt substrate with a phosphorylation site at Thr246 and acts as a negative regulator when bound to mTORC1. PRAS40T246A expressed in BK5.PRAS40mt mice remained bound to raptor even after TPA treatment as determined by immunoprecipitation analysis. BK5.PRAS40mt mice displayed reduced phosphorylation of both S6K (T389) and 4EBP1 (S65) in epidermis following treatment with TPA. Furthermore, these transgenic mice were significantly less sensitive to TPA-induced epidermal proliferation (measured by both epidermal thickness and labeling index) compared to nontransgenic siblings. TPA-mediated migration and proliferation of LRCs was also inhibited in BK5.PRAS40mt mice. BK5.PRAS40mt mice also expressed lower levels of cell cycle proteins in epidermis after TPA treatment. Collectively, the current data further support the hypothesis that downstream signaling pathways through mTORC1 contribute significantly to the process of skin tumor promotion through effects on proliferation. Supported by CA37111 and 129409.

Citation Format: Okkyung Rho, John DiGiovanni. Targeting mTORC1 by epidermal overexpression of PRAS40(T246A) suppresses TPA-induced epidermal hyperplasia during tumor promotion. [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 1302. doi:10.1158/1538-7445.AM2013-1302
Abstract 1303: Key roles for Gab1, phosphatidylinositol-3-kinase, COX-2, prostaglandin E2 and TGF-alpha in linoleic acid-induced upregulation of lung and breast cancer cell growth.
Authors: Kikawa Keith D. , Martins Clarissa R. , Johnson Eric D. , Beck Kristen , Mouradian Michael , Pardini Ronald S.
Published: August 2014

The omega-6 polyunsaturated fatty acid, linoleic acid (LA), is prevalent in Western diets and is known to enhance the tumorigenesis of mammary cancer models; with previous work demonstrating an upregulation of phosphatidylinositol-3-kinase (PI3K) signaling may play a key role. In this study, a mechanism for LA's upregulation of cancer cell growth is defined. High levels of LA in animal diets or cell culture medium initiates a series of events beginning with increased cyclooxygenase (COX) activity, which leads to increased prostaglandin E2 (PGE2) production, that subsequently increases matrix metalloproteinase (MMP) levels and transforming growth factor alpha (TGF-α). TGF-α is a classic growth factor for the epidermal growth factor receptor 1 (EGFR), which plays a role in a large number of cancers. The Grb2-associated binding protein 1 (Gab1) is a scaffolding protein that can complex with EGFR to activate PI3K signaling. Recent studies in our laboratory reveal LA supplementation of the breast cancer cell line BT-474 and the lung adenocarcinoma cell line A549 greatly increases the association between Gab1 and EGFR, while at the same time dramatically decreasing Gab1 protein levels. These changes are concomitant with increases in activated Akt (pAkt), a downstream signaling component in the PI3K signaling pathway. Moreover, inhibitors of EGFR, PI3K and Gab1-specific siRNAs are capable of reversing LA-induced upregulation of pAkt, as well as observed increases in cell proliferation for these models. These data establish Gab1 as major target in LA-induced enhancement of tumorigenesis.

Citation Format: Keith D. Kikawa, Clarissa R. Martins, Eric D. Johnson, Kristen Beck, Michael Mouradian, Ronald S. Pardini. Key roles for Gab1, phosphatidylinositol-3-kinase, COX-2, prostaglandin E2 and TGF-alpha in linoleic acid-induced upregulation of lung and breast cancer cell growth. [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 1303. doi:10.1158/1538-7445.AM2013-1303
Abstract 1304: HSF1 facilitates cell transformation by enhancing the expression of extracellular proteins.
Authors: Kuo Hsiao-Hui , Yih Ling-Huei
Published: August 2014

The expression level or the activity of heat shock factor-1 (HSF1), a master transcriptional regulator of the heat shock response, is elevated in cancer cell lines and tumor tissues. Loss of HSF1 function has been demonstrated to prevent oncogenesis. We thus examined whether and how HSF1 induces cell transformation using anchorage-independent growth as a surrogate for transformation phenotype. CGL2 cells overexpressing HSF1 (CGL2-wtHSF1) were more proficient to form colonies in soft agar than the parental control cells (CGL2-Neo). Cells stably depleted of HSF1 (CGL2-shHSF1), on the other hand, were unable to form colonies in soft agar. The diminished ability of CGL2-shHSF1 cells to grow in soft agar was rescued by ectopic expression of wild-type HSF1 but not an S326A substitution mutant or a C-terminal (transactivation domain) deletion mutant, indicating that phosphorylation at S326 and/or the transactivation activity of HSF1 was required for its ability to enhance anchorage-independent growth. In addition, conditioned medium collected from HSF1-overexpressing cells could induce anchorage-independent growth of HSF1-depleted cells. These results indicated that HSF1 might enhance cell transformation by transactivating the expression of particular extracellular proteins.

Citation Format: Hsiao-Hui Kuo, Ling-Huei Yih. HSF1 facilitates cell transformation by enhancing the expression of extracellular proteins. [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 1304. doi:10.1158/1538-7445.AM2013-1304
Abstract 1315: Regulation of Nodal expression by estrogen in hormone responsive human breast cancer cell lines.
Authors: Das Padmalaya , Quail Daniela , Postovit Lynne-Marie
Published: August 2014

Breast cancer is one of the most common cancers among Canadian women. Estrogen plays a key role in the in the normal growth and development of the breast and is also a major contributor to breast cancer growth. Recent studies have demonstrated that embryonic morphogen, Nodal is expressed in metastatic breast cancers and that its expression is correlated with breast cancer progression. In silico analysis of the Nodal promoter has revealed putative estrogen receptor binding sites (ERE) in proximity to the transcription start site. Our goal in this study is to investigate the role of estrogen on Nodal expression in human breast cancer cell-lines. Stimulation of MCF-7 and T47D breast cancer cell-lines that are estrogen receptor positive and express low levels of Nodal with 10nM of estradiol (E2) for varying amounts of time revealed that Nodal protein expression increases at about 48 hours after E2 exposure and persists up to 120 hours. Treatment with the E2 antagonist, ICI-182,780 (ICI) abrogates the E2-enhanced Nodal protein expression. Conversely, treating the MCF- 7 and T47D cells with recombinant Nodal resulted in a decreased expression of estrogen receptor in these cells both at the transcript and protein levels. These preliminary results suggest that there is a bidirectional interaction between estrogen receptor and Nodal in these cell-lines. Future experiments are aimed at understanding in depth this bidirectional phenomenon to provide better insight into hormonal regulation in metastatic breast cancer.

Citation Format: Padmalaya Das, Daniela Quail, Lynne-Marie Postovit. Regulation of Nodal expression by estrogen in hormone responsive human breast 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 1315. doi:10.1158/1538-7445.AM2013-1315
Abstract 1319: Regulation of AR transcriptional activity and prostate cancer cellular proliferation by DACH1/Eya1/Six1 pathway.
Authors: Wang Jing , Cai Shaoxin , Chen Ke , Li Sean , Pestell Richard , Wu Kongming
Published: August 2014

Prostate cancer progression from androgen responsive to androgen-depletion therapy resistance is a major cause of treatment failures. Novel therapies targeting this patient are a major clinical challenge. We previously reported that the cell fate determination factor DACH1 inhibits androgen signaling though binding the AR and enhancing co-repressor recruitment in the context of local chromatin at AR responsive genes. The repression of AR function of by DACH1 was partly rescued by the co-activators p300 and SRC. The repression was enhanced by ectopic expression of HDACs. We had previously shown that DACH1 inhibited proliferation of androgen-dependent LnCAP cells. To further explore the significance of DACH1 in human prostate cancer, we established stable cell lines expressing DACH1 or its DS domain deleted mutant (ΔDS) in androgen-independent C4-2 cells and AR-negative PC-3 cells by retrovirus infection. Stable expression of DACH1 inhibited cellular proliferation in both cell lines, requiring the DS domain. Ectopic expression of DACH1 inhibited colony formation of the androgen-independent 22RV1 cells. DACH1 inhibited migration, invasion and tumor growth of AR-negative PC-3 cells. Since DACH1, Eya1 and Six1 function together as a network to control cellular differentiation and organ formation during development, we examined whether other components of RDGN pathway, could regulate androgen signaling. In hormone responsive LnCAP cells, ligand stimulation (DHT, 50nM) induced 17 folds activation of MMTV Luc, co-expression of Eya1 reduced AR transactivation, and the repression required the EYA phophatase domain. Expressions of the AR co-repressors, HDAC1, HDAC3 or SirT1 inhibited the ligand-induced AR activity. Eya1 enhanced co-repressor function at the PSA and MMTV promoters. Consistent with our previous publication, DACH1 repressed ligand-induced activity >70%, Eya1 modified DACH1 repression of AR activity. Together, our studies demonstrated that the RDGN regulates both androgen dependent and independent prostate cancer cellular proliferation and tumorigenesis.

Citation Format: Jing Wang, Shaoxin Cai, Ke Chen, Sean Li, Richard Pestell, Kongming Wu. Regulation of AR transcriptional activity and prostate cancer cellular proliferation by DACH1/Eya1/Six1 pathway. [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 1319. doi:10.1158/1538-7445.AM2013-1319
Abstract 132: Divergent estrogen receptor positive and negative breast cancer trends and etiologic heterogeneity in Denmark .
Authors: Anderson William F. , Rosenberg Philip , Petito Lucia , Katki Hormuzd A. , Ejlertsen Bent , Ewertz Marianne , Rasmussen Birgitte B. , Jensen Maj-Britt , Kroman Niels
Published: August 2014

Background: Long-term breast cancer trends in incidence in the United States (US) show rising ER positive rates and falling ER negative rates. We hypothesized that these divergent trends reflect etiologic heterogeneity and that comparable trends should be observed in other countries with similar risk factor profiles.

Methods: We analyzed invasive female breast cancers in Denmark from 1993-2010. We summarized the overall trend in age-standardized rates with the estimated annual percentage change (EAPC) statistic, and used age-period-cohort models to estimate age-specific EAPCs, cohort rate ratios (CRRs), and projections for future time periods (2011-2018).

Results: In Denmark, the overall rate of ER positive cancers rose between 1993 and 2010 by 3·0%/year (95% CI: 2·8 to 3·3%/yr) while the overall rate of ER negative cancers fell by 2·1%/year (95% CI: -2·5 to -1·6%/yr). The ER positive rate increased fastest among postmenopausal women and the ER negative rate decreased fastest among premenopausal women, reflecting that cohorts born after 1944 were at relatively higher risk of ER positive tumors and lower risk of ER negative tumors. If current trends continue, ER positive cancers will increase at least 13% and ER negative cancers will fall as much as 15% by 2018.

Conclusion: Divergent ER-specific trends are consistent with distinct etiologic pathways. If trends in known risk factors are responsible, the Danish and US experience may foreshadow a common pattern worldwide.

Citation Format: William F. Anderson, Philip Rosenberg, Lucia Petito, Hormuzd A. Katki, Bent Ejlertsen, Marianne Ewertz, Birgitte B. Rasmussen, Maj-Britt Jensen, Niels Kroman. Divergent estrogen receptor positive and negative breast cancer trends and etiologic heterogeneity in Denmark . [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 132. doi:10.1158/1538-7445.AM2013-132
Abstract 1326: Oral enclomiphene citrate lowers IGF-1 in men with secondary hypogonadism while raising testosterone: Implications for cancer prevention.
Authors: Wiehle Ronald D. , Fontenot Gregory K.
Published: August 2014

Introduction: Lowered hGH and IGF-1 have been linked with protection from various cancers.

Methods and Subjects: We determined levels of IGF-1 and pituitary hormones in men with secondary hypogonadism under treatment with enclomiphene (a.k.a. Androxal) in comparison to topical testosterone (T) or placebo. Three, randomized, blinded, phase II studies evaluating daily oral Androxal were performed: ZA-201 investigated 12 men taking 25mg of Androxal in comparison to a gel for 6 months, ZA-202 enrolled 119 diabetic men taking 12.5 or 25 mg Androxal versus placebo for 3 months, and ZA-204 investigated 47 men taking 6.25mg, 12.5mg and 25mg Androxal versus another gel for 6 weeks. All subjects had initial total T <350 ng/dL and low-to-normal LH (<12 IU/L). Serum samples were taken for T, LH and FSH before and after dosing. We could not measure hGH directly but measured its marker, liver-produced IGF-1.

Results: All treatments raised T into the normal range (300-1000 ng/dL), but placebo did not in ZA-202. Androxal elevated LH and FSH. Gels decreased LH and FSH strongly. Unexpected was the strong action of Androxal to lower serum IGF-1 in all three trials. Both Androxal and topicals lowered serum IGF-1 but Androxal was more effective. An example is given from ZA-204 below. Dose groups showed no differences in IGF-1 before (p = 0.94) but significance after treatment (p = 0.03),

Conclusions: Endocrine profile indicate that enclomiphene citrate stimulates the pituitary, resulting in increased LH and FSH and eventually T. The results on IGF-1 cannot be attributed to T since topicals, when used, raised T but not IGF-1 whereas only enclomiphene citrate raised T but lowered IGF-1. Enclomiphene citrate is different from topicals and may be a new way to relieve low T in men with an intact hypothalamus-pituitary-testicular axis. If Androxal can lower hGH or IGF-1 in aging men at risk for prostate cancer, its use in men with secondary hypogonadism is an important new treatment.

Effect of Treatment on IGF-1 dose subjects IGF-1 (SD)before IGF-1 (SD) after Versus Gel MMW 6.25mg 12 101 (43) 54 (30) p<0.01 12.5mg 10 94 (47) 50 (24) p<0.005 25mg 12 96 (45) 62 (42) p<0.01 Gel 13 103 (46) 90 (34)

Citation Format: Ronald D. Wiehle, Gregory K. Fontenot. Oral enclomiphene citrate lowers IGF-1 in men with secondary hypogonadism while raising testosterone: Implications for cancer prevention. [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 1326. doi:10.1158/1538-7445.AM2013-1326
Abstract 1328: Evaluation of common genetic variants in 15 colorectal cancer susceptibility loci among African Americans .
Authors: Zhang Ben , Cai Qiuyin , Long Jirong , Li Guoliang , Signorello Lisa B. , Shrubsole Martha J. , Blot William J. , Zheng Wei
Published: August 2014

Background: Genome-wide association studies (GWAS) conducted primarily in populations of European ancestry, have identified multiple single-nucleotide polymorphisms (SNPs) at 15 loci associated with colorectal cancer (CRC) risk. Limited studies have been conducted to evaluate the association of these SNPs with colorectal neoplasia risk in African Americans.

Methods: We analyzed 19 SNPs within 15 CRC loci in African Americans recruited from two studies, including 206 CRC cases and 1,000 controls from the Southern Community Cohort Study (SCCS), and 203 colorectal adenoma cases and 461 controls from the Tennessee Colorectal Polyp Study (TCPS). Logistic regressions were used to derive adjusted odds ratios and their 95% confidence intervals for the associations between SNPs and disease risk. We also performed a meta-analysis including 1,586 cases and 2,956 controls regarding the association of 11 SNPs with colorectal neoplasia risk in African Americans.

Results: In the combined analysis of data from the SCCS and TCPS, we found two SNPs (rs10505477 and rs6983267) at 8q24 to be significantly associated with colorectal neoplasia risk (P < 0.05). Two additional SNPs, rs7758229 (SLC22A3) and rs4444235 (14q22), showed marginally significant associations with colorectal neoplasia (P < 0.10). In the meta-analysis including data from this study and two other studies, rs16892766 (8q23), rs6983267 (8q24), and rs7014346 (8q24) were significantly associated with colorectal neoplasia with no evidence of heterogeneity across studies.

Conclusions: Genetic variants at 8q23 and 8q24 identified in GWAS conducted in European descendants may also be associated with colorectal neoplasia risk in African Americans.

Impact: Findings from this study may be helpful for future studies to fine-map GWAS-identified loci to identify causal variants for CRC.

Citation Format: Ben Zhang, Qiuyin Cai, Jirong Long, Guoliang Li, Lisa B. Signorello, Martha J. Shrubsole, William J. Blot, Wei Zheng. Evaluation of common genetic variants in 15 colorectal cancer susceptibility loci among African Americans . [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 1328. doi:10.1158/1538-7445.AM2013-1328
Abstract 1329: PSPHL and breast cancer in African American women: Causativegene or population stratification.
Authors: Rummel Seth , Penatzer Cayla , Shriver Craig D. , Ellsworth Rachel E.
Published: August 2014

Background: The phophoserine phosphatase-like (PSPHL) gene, first identified as overexpressed in fibroblasts from patients with

Fanconi anemia, is expressed at significantly higher levels in breast tumors as well as stromal tissues from African American women (AAW) compared to Caucasian women (CW). The function of PSPHL has not been determined, thus how overexpression of PSPHL impacts tumor etiology or contributes to outcome disparities in African American women is unclear. Here, we evaluated the molecular mechanisms driving expression differences between populations to determine whether expression differences are causative or represent population stratification.

Methods: A PCR-based approach was used to detect the retention or deletion of a 30-kb segment of 7p11 that includes the first three exons of PSPHL. Genotypes were determined using genomic DNA from AAW with invasive breast cancer (n=220), AAW without breast cancer (n = 352) and CW with invasive breast cancer (n=508). Gene expression levels were evaluated by

qRT-PCR using RNA isolated from breast tumors from 52 CW and 43 AAW. Genotype frequencies were analyzed using chi-square analysis and gene expression levels by a Mann-Whitney U-test;

P<0.05 was used to define significance.

Results: Gene expression levels were correlated with the presence or absence of the 30-kb deletion of 7p11: patients homozygous for the deletion had no detectable expression of PSPHL, while patients heterozygous for the deletion had expression levels 2.5-fold lower than those homozygous for retention of PSPHL. When the frequency of the deletion was evaluated by ethnicity, 62% of CW were homozygous for the deletion of PSPHL compared to 5% of AAW with invasive breast cancer (P<0.00005). In contrast, genotype frequencies did not differ significantly between AAW with invasive breast cancer compared to AAW controls (P=0.116).

Conclusions: The deletion of 30-kb of chromosome 7p11 prevents expression of PSPHL. The prevalence of the deletion allele is 77% in CW compared to 23% in AAW, suggesting that this 30-kb deletion and subsequent disruption of PSPHL may be a derived trait in Caucasians. Although the deletion frequency and associated expression differ significantly between

AAW and CW with invasive breast cancer, the similar frequency of the deletion allele in AAW with and without invasive breast cancer suggests that these genetic differences represent population stratification, and do not contribute to outcome differences between AAW and CW with breast cancer.

Citation Format: Seth Rummel, Cayla Penatzer, Craig D. Shriver, Rachel E. Ellsworth. PSPHL and breast cancer in African American women: Causativegene or population stratification. [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 1329. doi:10.1158/1538-7445.AM2013-1329
Abstract 1336: A population-based study of Transforming Growth Factor-Beta1 (TGFB1) polymorphisms and risk of breast cancer.
Authors: Bewick Mary A. , Conlon Michael SC
Published: August 2014

Transforming growth factor-beta1 (TGFB1) is a multifunctional cytokine that may play an important role in the development and progression of cancer. The results of a number of association studies of TGFB1 polymorphisms and breast cancer risk are inconclusive. This study examined 4 single nucleotide polymorphisms (SNPs) in TGFB1 and risk of breast cancer using data previously collected from a population based case-control study (n=307 cases and 664 controls) of Caucasian women conducted in Northeastern Ontario, Canada. The SNPs (rs8179181, rs8110090, rs1800470 (L10P), rs1800469 (-509C/T)) were selected as either tag SNPs or had been identified as potentially functional in other studies, and were analysed using Taqman genotyping assays. Two of the SNPs were at the 5’ end (rs1800469 (-509C/T), rs1800470) and were in high LD (D’ 0.98); the remaining SNPs (rs8179181, rs8110090) were at the 3’ end and were also in high LD (D’ 0.99). In single-SNP analyses, the variant homozygous genotypes in rs1800470 (CC) and rs8179181 (AA) were significantly protective in the codominant model with Odds Ratios (OR) and 95% Confidence Intervals (95% CIs) of 0.63 (0.40-0.99) and 0.45 (0.21-0.96), while the AG genotype of rs8110090 was significantly associated with increased breast cancer risk with an OR of 1.78 (95% CI 1.14-2.77). Of the seven estimated haplotypes, 3 were significantly protective for breast cancer; when compared to the referent haplotype (see Table). In conclusion, our results suggest that SNPs at both the 3’ and 5’ end of TGFB1 may be associated with risk of breast cancer, and future studies examining additional polymorphisms in these regions would be valuable.

Haplotype association with breast cancer risk (n = 969; Global Haplotype Association p-value 0.0021)rs8179181rs8110090rs1800470rs1800469FrequencyOR (95% CI)P-value1GATC0.40281.002GACT0.23870.73 (0.55–0.97)0.033AATC0.17280.67 (0.48–0.93)0.0174GACC0.06710.49 (0.30–0.81)0.00545AACT0.0560.55 (0.30–1.00)0.0526GGTC0.02981.00 (0.48–2.09)0.997GGCT0.02271.82 (0.82–4.06)0.14

Citation Format: Mary A. Bewick, Michael SC Conlon. A population-based study of Transforming Growth Factor-Beta1 (TGFB1) polymorphisms and risk 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 1336. doi:10.1158/1538-7445.AM2013-1336
Abstract 1342: Genetic variations in the MUC16 gene encoding tumor marker CA125 and their association with the risk of epithelial ovarian cancer.
Authors: Williams Kristina , Terry Kathryn , Vitonis Allison , Cramer Daniel
Published: August 2014

Purpose: MUC16 is a cell surface mucin that is expressed at high levels by epithelial ovarian tumors, and is detected in serum as the CA125 antigen. MUC16 is clinically used as a tumor marker in the management of ovarian cancer and has been associated with prognosis. MUC16 is also thought to play an important role in ovarian tumor cell survival and metastasis. We studied the association of four tagging SNPs of the MUC16 gene (rs2547065 (C/G), rs1559168 (A/T), rs2121133 (A/G), rs2121133 (A/G)) and risk of ovarian cancer as well as the correlation of these SNPs with CA125 levels.

Methods: MUC16 polymorphisms were genotyped using blood samples collected from 760 women diagnosed with ovarian cancer and 788 healthy controls enrolled in the New England Case-Control Study between 2003 and 2008. 388 cases had preoperative CA125 levels abstracted from medical records. Odds ratios and 95%CIs were calculated using logistic regression; polytomous (multinomial) logistic regression was used to estimate multivariate odds ratios by ovarian cancer histological subtype. The association between log normalized pre-operative CA125 levels and MUC 16 SNPs was evaluated using generalized linear models.

Results: A significant association was observed between the rs2547065 polymorphism and ovarian cancer risk (per allele: OR=1.30, 95% CI: 1.11-1.52). The risk was greatest for women carrying two copies of the variant allele (OR=1.78, 95% CI: 1.29-2.45). When stratified by histological subtype, these associations were most apparent in the recessive model for women with serous invasive (OR = 1.69; 95%CI: 1.15-2.48) and clear cell (2.49 95% CI: 1.13-5.52) tumors. There were no significant associations between the other three MUC16 SNPs (rs1559168, rs2121133, rs12984471) and ovarian cancer risk. The rs2547065 polymorphism was not found to be associated with pre-operative CA125 levels in cases overall or in the subset of women with serous and clear cell cancers.

Conclusions: These results suggest that women who carry one or more variant alleles of MUC16 SNP rs2547065 have an increased risk of ovarian cancer of the serous invasive and clear cell histological subtype. Further study of MUC 16 SNPs in relation to risk of ovarian cancer and their effect on CA125 levels is warranted.

Citation Format: Kristina Williams, Kathryn Terry, Allison Vitonis, Daniel Cramer. Genetic variations in the MUC16 gene encoding tumor marker CA125 and their association with the risk of 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 1342. doi:10.1158/1538-7445.AM2013-1342