bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3515: Pathway convergent evolution underscores treatment response to MTOR inhibitors in kidney cancers.
Authors: Voss Martin H. , Hakimi A Ari , Pham Can G. , Brannon A Rose , Chen Ying-Bei , Cunha Luis F. , Akin Oguz , Liu Han , Takeda Shugaku , Scott Sasinya N. , Socci Nicholas D. , Viale Agnes , Schultz Nikolaus , Sander Chris , Reuter Victor E. , Russo Paul , Cheng Emily H. , Motzer Robert J. , Berger Michael F. , Hsieh James J.
Published: August 2014

Despite the established role of MTOR inhibitors (rapalogs) in treating advanced kidney cancer, therapeutic benefit varies and predictive biomarkers are lacking. Intratumor branching heterogeneity, a recently discovered hallmark of this disease, has raised concerns about the feasibility of developing genomic biomarkers for targeted agents in kidney cancer. We undertook an outlier approach to interrogate the genetic determinants underlying long-term therapeutic response (>20 months) to rapalogs in 6 patients. An integrated ultra-deep targeted-exome (∼500x) and standard whole-exome (∼100x) sequencing was performed. Additionally, to address intratumor and intertumor heterogeneity, spatially separated tumor specimens from the same individuals were analyzed whenever possible. Multiregional sequencing unveiled surprising MTOR pathway convergent evolution, manifested by MTOR pathway activation by means of distinct genomic events in spatially separate sites of disease within the same individual. Amongst the core components of the MTORC1 pathway, complete functional loss of TSC1 and TSC2, and a hyperactive MTOR mutant were discovered in 4 of 6 long-term responders. Mutations in MTOR Clustered at FAT and kinase domains confer hyperactivity and yet remain sensitive to rapamycin. Here, we affirm intratumor heterogeneity, identify genomic determinants of drug response, and discover pathway convergent evolution in the majority of long-term responders. We propose a “river” model in which intratumor and intertumor clonal heterogeneity in cancer patients evolves like a branching river that converges at critical nodes. These convergent points provide unique opportunities for the treatment of genetically diverged yet functionally converged cancers in any given patient.

Citation Format: Martin H. Voss, A Ari Hakimi, Can G. Pham, A Rose Brannon, Ying-Bei Chen, Luis F. Cunha, Oguz Akin, Han Liu, Shugaku Takeda, Sasinya N. Scott, Nicholas D. Socci, Agnes Viale, Nikolaus Schultz, Chris Sander, Victor E. Reuter, Paul Russo, Emily H. Cheng, Robert J. Motzer, Michael F. Berger, James J. Hsieh. Pathway convergent evolution underscores treatment response to MTOR inhibitors in kidney cancers. [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 3515. doi:10.1158/1538-7445.AM2013-3515
Abstract 3521: B7-H3 associated with tumor progression and epigenetic regulatory activity in cutaneous melanoma.
Authors: Wang Jinhua , Chong Kelly , Huang Sharon , Hoon Dave
Published: August 2014

B7-H3 is a transmembrane glycoprotein and a member of the B7/CD28 immunoglobulin superfamily which plays an important functional role in tumor surveillance by T-cells. High expression of B7-H3 has been related to a poor prognosis in some tumor types. Melanoma is the most aggressive form of skin cancer. B7-H3 expression was evaluated by RT-qPCR and IHC analysis on individual melanoma specimens and then verified in clinically annotated melanoma stage III and stage IV metastasis tissue microarrays(TMA) in a double blind study. B7-H3 mRNA expression was shown to be significantly increased with stage of melanoma(P<0.0001) and significantly associated with melanoma-specific survival(MSS) in both stage III(P<0.0001) and stage IV(P<0.012) melanoma patients. B7-H3 expression was related to migration and invasion of melanoma cells; overexpression B7-H3 increased migration and invasion while knockdown of B7-H3 reduced cell migration and invasion. MiR-29c expression was shown to inversely regulate B7-H3. Furthermore, we demonstrated that B7-H3 expression was related to p-STAT3 expression in melanoma. These results suggest B7-H3 may be a useful biomarker for melanoma progression and patients’ outcome.

Citation Format: Jinhua Wang, Kelly Chong, Sharon Huang, Dave Hoon. B7-H3 associated with tumor progression and epigenetic regulatory activity in cutaneous melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3521. doi:10.1158/1538-7445.AM2013-3521
Abstract 3522: Vincristine activates c-Jun N-terminal kinase in chronic lymphocytic leukemia in vivo.
Authors: Bates Darcy JP , Danilov Alexey V. , Beaulieu Bernard B. , Lewis Lionel D. , Eastman Alan
Published: August 2014

Chronic lymphocytic leukemia (CLL) is a cancer of B cell lymphocytes whose survival depends on the anti-apoptotic activity of Bcl-2 family proteins. Due to the low growth fraction of CLL cells, drugs that kill during mitosis, such as the microtubule-targeting vinca alkaloids, are not expected to be effective. However, we have found that vincristine and vinblastine can act independently of mitosis and induce acute apoptosis in freshly isolated CLL cells. The mechanism of this effect still depends on destabilization of microtubules as similar events occur with combretastatin A4 which destabilizes microtubules through binding to a different site on tubulin.

Vinca-mediated apoptosis in CLL cells can be enhanced by addition of the cyclin-dependent kinase (CDK) inhibitor dinaciclib, killing cells acutely within 6 h. Dinaciclib functions by inhibiting CDK9, suppressing transcription and preventing expression of Mcl-1. The combination of dinaciclib and vinca alkaloids depends on vinca-induced phosphorylation of c-Jun N-terminal kinase (JNK). Therefore, we investigated whether JNK phosphorylation occurs in peripheral blood CLL cells in patients receiving vincristine. Patients received 2 mg vincristine intravenously by infusion over 5 minutes. Venous blood samples were obtained at time zero (pre-treatment) and post drug administration for up to 6 h. Patients then continued to receive chemotherapy treatment as prescribed by their primary oncologist. Pre-treatment CLL cells were studied ex vivo for JNK phosphorylation on exposure to vincristine. These studies showed that CLL cells phosphorylated JNK in response to clinically relevant concentrations of vincristine (10-50 nM). In the CLL cells from all 4 patients studied thus far, vincristine led to rapid (≤ 1 h) JNK phosphorylation which was sustained for 4-6

h post vincristine administration. These proof-of-principle study results provide justification for the development of a Phase I study to define the effect of the combination of vinca alkaloids and dinaciclib in patients with CLL.

Citation Format: Darcy JP Bates, Alexey V. Danilov, Bernard B. Beaulieu, Lionel D. Lewis, Alan Eastman. Vincristine activates c-Jun N-terminal kinase in chronic lymphocytic leukemia in vivo. [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 3522. doi:10.1158/1538-7445.AM2013-3522
Abstract 3525: Functional analysis of epidermal growth factor receptor tyrosine kinase inhibitors: A comparison of Afatanib, Lapatinib, and Gefitinib in human tumor primary cultures.
Authors: Nagourney Robert Alan , Bernard Paula J. , Federico Eric , Nguyen Sophie , Evans Steven S.
Published: August 2014

Introduction:

Targeting epidermal growth factor receptor (EGFr) tyrosine kinases has provided effective therapies for NSCLC, breast & GI cancers. However, secondary mutations can confer resistance. New multi-targeted and/or irreversible inhibitors (TKI's) may overcome these mechanisms. We used the ex vivo analysis of programmed death (EVA/PCD) to compare the activity of the irreversible EGFr TKI, BIBW 2992 (Afatanib) with Gefitinib and Lapatinib and examined downstream signals with inhibitors of MEK/ERK & PI3K/mTOR. Methods: Human tumor 1° culture microspheroids isolated from 54 individual-patient specimens obtained at surgery or aspiration were examined for EGFr-TKI induced programmed cell death, using morphologic & metabolic endpoints as previously described (Nagourney R, Curr. Treat Opt in Oncol., 2006). Lethal concentration 50% (LC50’s) interpolated from 5-point dose response curves were compared and drug correlations were conducted by Pearson-Moment. Results: BIBW activity favored upper GI, NSCLC and ovary over breast and colorectal cancer. In NSCLC, EGFr mutation (+) tumors were significantly more sensitive than wild type to BIBW (P < .05). Patients relapsing after Erlotinib who carried T790M mutations remained BIBW sensitive despite Gefitinib resistance. BIBW activity correlated with Gefitinib (r = 0.35, P= 0.05) and the MEK/ERK inhibitor AZD 6244 (r = 0.43, P < 0.05) and trended to correlation with Lapatinib, but did correlate with mTOR or mTOR/PI3K inhibitors, Everolimus & BEZ235. Of 3 patients treated with Afatanib, 2 of 3 showed benefit, 1 durable SD & 1 durable PR. Conclusions: BIBW reveals activity in several tumor types including NSCLC, GI and ovary. In NSCLC LC50’s significantly favor EGFr mutation (+) ‘s with favorable results in T790M(+) patients. Correlations with

AZD 6244 but not Everolimus or BEZ235, suggest MEK/ERK pathway to be the operative survival signal. EVA/PCD analysis in human tumor 1°cultures offers a platform to study novel strategies for EGFr-targeted therapies. Supported by the Vanguard Cancer Foundation & the Nagourney Institute.

Citation Format: Robert Alan Nagourney, Paula J. Bernard, Eric Federico, Sophie Nguyen, Steven S. Evans. Functional analysis of epidermal growth factor receptor tyrosine kinase inhibitors: A comparison of Afatanib, Lapatinib, and Gefitinib in human tumor primary cultures. [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 3525. doi:10.1158/1538-7445.AM2013-3525
Abstract 3537: Serum cobalamin level and clinical outcome in patients with acute myeloid leukemia.
Authors: Bai Li-Yuan , Chen Tzu-Ting , Li Long-Yuan , Chiu Chang-Fang
Published: August 2014

Introduction: An elevated concentration of serum cobalamin was found in one third of patients with acute myeloid leukemia; however, the clinical implication of elevated level of cobalamin in disease prognosis is not clear.

Procedures: We performed a retrospective analysis of the patients who were diagnosed to have de novo acute myeloid leukemia at China Medical University Hospital from January 2003 to December 2011. Two hundred and six patients were diagnosed as de novo acute myeloid leukemia, and thirty-four patients (16.5%) had been checked the level of serum cobalamin at diagnosis. Patients were divided into two groups, one with serum cobalamin level less than 400 pg/mL (n=10), the other with serum cobalamin level 400 pg/mL or higher (n=24). The clinical and cytogenetic characteristics between each group were compared.

Findings: There was no difference in gender, age and cytogenetic risk between the two groups. Nine of ten patients in lower serum cobalamin group and eighteen of twenty-four patients in higher serum cobalamin group received intensive chemotherapy for acute myeloid leukemia (p=0.315). The patients with lower serum cobalamin had a trend to obtain complete remission (80.0 % vs. 45.8 %, p=0.072). For patients who reached complete remission after chemotherapy, those in the higher cobalamin group had a trend to have more disease relapse (81.8% vs. 37.5%, p=0.067). Interestingly, the relapse-free survival time after complete remission was 42.5 m and 9.2 m for patients with lower and higher cobalamin, respectively (p=0.010). Furthermore, serum cobalamin level remained significant in the multivariate analysis of risk factors for relapse-free survival (p=0.028). The median overall survival time was 18.3 m and 7.2 m for patients with lower and higher cobalamin, respectively. However, the difference in overall survival between the two groups did not reach statistical significance (p=0.140). In multivariate analysis, intensive chemotherapy for AML was the most important factor for overall survival.

Conclusions: AML patients with higher serum level of cobalamin have a trend of worse response to chemotherapy, higher relapse rate and significantly shorter relapse-free survival time. Targeted therapy to interfere the cobalamin uptake or related pathways is worth of further investigation in treating patient with acute myeloid leukemia.

Citation Format: Li-Yuan Bai, Tzu-Ting Chen, Long-Yuan Li, Chang-Fang Chiu. Serum cobalamin level and clinical outcome in patients with acute myeloid leukemia. [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 3537. doi:10.1158/1538-7445.AM2013-3537
Abstract 3546: S-Glutathionylation of buccal mucosal cell proteins as biomarkers of oxidative stress.
Authors: Grek Christina L. , Manevich Yefim , Townsend Danyelle M. , Tew Kenneth D.
Published: August 2014

Many anticancer drugs produce reactive oxygen species (ROS) that directly or indirectly lead to toxicities. As a conduit to drug development we have identified S-glutathionylated (post-translational addition of glutathione to susceptible cysteine residues) serine proteinase inhibitors (serpin's A1 and A3) as plausible biomarkers for drug exposure in both rodent and human blood. Commercial mouthwashes often contain redox-altering agents such as hydrogen peroxide (H2O2) and/or ethanol. Oxidative damage in buccal mucosa cells is associated with etiology of oral cancers and we hypothesized that these cells may also serve to provide a surrogate tissue source for biomarker analysis to measure S-glutathionylated proteins. Using an approved clinical protocol for exfoliated buccal cell samples, we have identified a number of S-glutathionylated proteins, including actin, in samples from volunteers following standard treatments with a commercial mouthwash containing H2O2 (1.5%). Their identities are similar to those discovered using in vitro experiments with the human buccal cell line TR146. Our current data show a time and dose-dependent increase in S-glutathionylation of buccal cell sample profiles in normal volunteers following four days of exposure dosing to H2O2 containing mouthwash. Increases in protein S-glutathionylation occurred immediately following exposure and remained for 30min following treatments. Higher levels of S-glutathionylation were maintained with each subsequent daily exposure. These increased levels of S-glutathionylation preceded the transcriptional activation of ROS sensitive genes, incuding ATF3. The identification of biomarkers that evaluate the effects of oxidative stress in the oral cavity may define at-risk populations for oral cancer and may be useful as direct biomarkers for the impact of drugs on general redox status.

Citation Format: Christina L. Grek, Yefim Manevich, Danyelle M. Townsend, Kenneth D. Tew. S-Glutathionylation of buccal mucosal cell proteins as biomarkers of oxidative stress. [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 3546. doi:10.1158/1538-7445.AM2013-3546
Abstract 3549: RUNX3 is a biomarker for determining sensitivity to pheophorbide a-photodynamic therapy in human oral squamous cell carcinoma.
Authors: Moon Sook , Bae Jung Yoon , Lee Doo Young , Park Gyeong Ju , Yoo Hyun , Ko Hyo jin , Kim Yong Chul , Kim Jin
Published: August 2014

Background & Objective: Photodynamic therapy (PDT) with photosensitizer is one of the promising modalities for cancer treatment. For clinical use of PDT, the screening process for sensitive cancers to PDT should be preceded. For this, we investigated a molecular biomarker to determine the sensitivity to Pa-PDT in immortalized human oral keratinocytes (IHOK) and OSCC cell lines.

Methods: For this study, two immortalized oral keratinocytes (IHOK-p, IHOK-s) and 8 oral squamous cell carcinoma (OSCC) cell lines were used. After cells were treated with Pa-PDT, phototoxicity and the level of reactive oxygen species (ROS) were measured. Apoptosis was measured using annexin V/PI staining and western blotting. mRNA and proteins of apoptotic genes were investigated by RT-PCR, real-time PCR, and western blotting. Transfection was performed using RUNX3-small interfering RNA.

Results: After Pa-PDT, cell viability was more than 50% reduced and ROS generated in IHOK and OSCC. In addition, apoptosis occurred in all cell lines. Among apoptosis-related genes, Bim expression was altered following Pa-PDT. Therefore, mRNA and protein expression of RUNX3, a gene upstream of Bim were examined by Pa-PDT. We found that RUNX3 was highly responsive to Pa-PDT. Furthermore, knockdown of RUNX3 expression reduced cytotoxicity by Pa-PDT. In addition, we found that the cytotoxicity by Pa-PDT was proportional to RUNX3 expression in OSCC cell lines.

Conclusion: This is the first study to find a new target molecule that enhances Pa-PDT effects in IHOK and OSCC cell lines. These results should be further proven by animal studies to apply to clinical trials. Nevertheless, the development of a PDT-dependent biomarker could provide a novel approach to improve the effects of PDT in oral precancerous and cancerous lesions.

Acknowledgments This study was supported by a grant of the Korean Health Technology R&D Project, Ministry for Health, Welfare & Family Affairs, Republic of Korea (No. A100490).

Citation Format: Sook Moon, Jung Yoon Bae, Doo Young Lee, Gyeong Ju Park, Hyun Yoo, Hyo jin Ko, Yong Chul Kim, Jin Kim. RUNX3 is a biomarker for determining sensitivity to pheophorbide a-photodynamic therapy in human oral 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 3549. doi:10.1158/1538-7445.AM2013-3549
Abstract 3550: Benefits of follow-up screening for Epstein Barr virus DNA in patients with localized nasopharyngial carcinoma .
Authors: Hsu Cheng-Lung
Published: August 2014

Objective: In this study, we investigated whether detection of Epstein Barr virus (EBV)-DNA in plasma is a prognostic indicator of disease recurrence in patients who have been treated for localized nasopharyngeal carcinoma.

Methods: Study subjects comprised 389 patients who had received treatment for localized nasopharyngeal carcinoma in our outpatient department. Copy numbers of EBV-DNA in plasma were assessed by real-time quantitative PCR. Patients in whom disease recurrence was suspected underwent positron emission tomography (PET) imaging studies.

Results: Plasma EBV-DNA was detectable in 60 of 63 (95%) patients with metastatic disease and all had positive PET findings. In addition, of the 45 patients with localized recurrent disease, plasma EBV-DNA was detectable in 23 (51%) patients and positive PET scan results were obtained in 40 (89%) of the patients. Of the 284 patients who were disease free, plasma EBV-DNA was detected in 90 (32%) patients. Of the 19 patients in disease free group who were suspected disease recurrence with PET scanning, 7 positive PET images were found including 3 second primary malignancy and 4 non-cancer lesions. Two lymphoma cases with positive EBV-DNA value sequentially attacked before or after their NPC were diagnosed.

Conclusions: EBV-DNA is a good marker of localized disease recurrence/metastasis after treatment for NPC but needs to be combined with imaging studies such as PET to monitor disease status.

Citation Format: Cheng-Lung Hsu. Benefits of follow-up screening for Epstein Barr virus DNA in patients with localized nasopharyngial 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 3550. doi:10.1158/1538-7445.AM2013-3550
Abstract 3559: FKBP5 is an androgen-responsive gene in thyroid cancer cells.
Authors: MacEwan Melanie E. , Wong Ken , Swati Ismatun , Xie Suqing , Rasul Mohammad , Ardacheva Olena , Buchsbaum Joseph , Shin Edward , Moscatello Augustine , Schantz Stimson , Tiwari Raj K. , Geliebter Jan
Published: August 2014

There has been a steady increase in the incidence thyroid cancer in the United States, with over 56,000 cases predicted for 2012. The increased aggressiveness of the disease and poorer clinical outcome in men and postmenopausal women may be due to androgen/androgen receptor (AR) related functions. FK506 binding protein 51 (FKBP5) is a member of the immunophilin family and plays a role in steroid receptor function. Further, FKBP5 regulates the NFkB and AKT pathways and is thought to be relevant to the neoplastic process. Immunohistochemical analysis of 38 papillary thyroid cancer (PTC) specimens indicated that androgen receptor is expressed in both normal and cancerous epithelial cells, in both men and women. Analysis of AR expression in thyroid cell lines indicated that the normal thyroid cell line, Nthy-ori 3-1 and PTC cell lines BCPAP and TPC-1 expressed very low levels of AR, as measured by qRT-PCR and western blotting (>1000 fold less than the prostate cancer cell line, LNCaP). In contrast, PTC/anaplastic 8505C cells expressed higher levels of AR protein (approximately one third the level expressed in LNCaP cells). Upon addition of androgen, AR in 8505C translocated into the nucleus (as determined by immunocytochemistry) and upregulated transcription of both AR (∼1.7 fold) and FKBP5 (∼1.8 fold). To more fully understand the function of androgen/AR in thyroid cells, the AR cDNA from pSG5-AR was subcloned into the pcDNA3.1+ expression vector and stably transfected into thyroid cell lines. Primers for qRT-PCR of the endogenous or the transfected gene were designed. The 84E7 clone of transfected 8505C cells expressed 68 fold higher levels of AR mRNA than 8505C and 16 fold higher AR protein expression (∼5 fold higher AR protein expression than LNCaP). Upon addition of DHT to clone 84E7, AR translocated into the nucleus, and increased AR and FKBP5 mRNA expression (∼3 fold and ∼13 fold, respectively). The association between androgens/AR and upregulation of FKBP5 in thyroid cancer cells suggests that FKBP5 may play a role in thyroid cancer etiology and the different clinical presentation and outcomes between young women and men/postmenopausal women.

Citation Format: Melanie E. MacEwan, Ken Wong, Ismatun Swati, Suqing Xie, Mohammad Rasul, Olena Ardacheva, Joseph Buchsbaum, Edward Shin, Augustine Moscatello, Stimson Schantz, Raj K. Tiwari, Jan Geliebter. FKBP5 is an androgen-responsive gene in thyroid cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3559. doi:10.1158/1538-7445.AM2013-3559
Abstract 3564: ARID1A promotes endocrine resistance in ER+ breast cancer cells.
Authors: Chabot Catherine , Basik Mark
Published: August 2014

We recently identified the ARID1A gene as a new candidate tumor suppressor gene (TSG), mutated in the T47D cells, an ER+ breast cancer cell line. We have shown previously that re-expression of ARID1A in T47D cells inhibits both proliferation and anchorage-independent growth and also that nuclear expression of ARID1A is progressively decreased during the later stages of breast tumor progression. ARID1A encodes a member of the SWI/SNF family of proteins, which function to ‘remodel’ chromatin and thereby regulate gene expression programs. Most breast cancers express the estrogen receptor (ER), and are thus responsive to the mitogenic effects of the estrogen hormone as well as to the anti-proliferative effects of anti-estrogen therapies. To uncover the potential role of ARID1A in the regulation of estrogen signaling in ER+ breast cancer cells, we tested if re-expression of ARID1A may also affect estrogen-dependent growth. Surprisingly, we found that re-expression of ARID1A in T47D cells results in a decrease in the proliferative response of these cells to estrogen but also to a decrease in the viability of the cells in hormone-depleted conditions. Then, to further investigate if the loss of ARID1A may promote estrogen-independent growth, we silenced ARID1A expression by shRNA in MCF-7 cells that express moderate levels of ARID1A protein. We found that ARID1A-silencing increases the survival of MCF-7 cells in the absence of hormones. In addition, we also observed that phosphorylation of FAK and Src, whose activities have been suggested to be important in endocrine resistance, is highly increased in the absence of ARID1A. All together, these results suggest that loss of ARID1A can promote endocrine-resistance in ER-positive breast cancer cells.

Citation Format: Catherine Chabot, Mark Basik. ARID1A promotes endocrine resistance in ER+ breast cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3564. doi:10.1158/1538-7445.AM2013-3564
Abstract 3566: Altering the expression levels of CRABPII and FABP5 by curcumin sensitizes MDA-MB231 mammary carcinoma cells to retinoic acid mediated growth suppression.
Authors: Thulasiraman Padmamalini , McAndrews Daniel
Published: August 2014

Although great progress has been made in the treatment of breast cancer, drug resistance is a major problem in breast cancer patients, promoting the need to understand the molecular mechanisms involved in the disease and identify future targeted therapy. Curcumin, a hydrophobic polyphenol extracted from the plant, Curcuma Longa, has been reported to possess anti-tumorigenic properties in several different cancers. Curcumin has been widely used in combination with other therapies to enhance apoptosis and promote anti-carcinogenic activities. In this study, we explore the effect of curcumin on retinoic acid binding proteins, cellular retinoic acid binding protein II (CRABPII) and fatty acid binding protein 5 (FABP5). Retinoic acid (RA) can inhibit carcinoma cell growth by activating nuclear retinoic acid receptors (RAR) but enhances cell proliferation and survival by activating a different nuclear receptor, namely PPARβ/δ (peroxisome proliferator activated-protein β/δ). The hormone is either targeted to RAR by CRABPII, or delivered to PPARβ/δ by FABP5. Hence, RA exerts anticarcinogenic activities in cells that express a high CRABPII/FABP5 ratio but facilitates the growth of carcinoma cells in which this ratio is low. We investigated whether curcumin can alter the ratio of CRABPII/FABP5 and promote retinoic acid mediated growth suppression in RA resistant MDA-MB231 mammary carcinoma cells. Using quantititive real-time PCR, we report that 30 μM curcumin suppresses the mRNA level of FABP5 and PPARβ/δ, while concomitantly enhances CRABPII mRNA expression by 3-fold. Additionally, we performed western blot analysis and demonstrated that in addition to the downregulation of FABP5 mRNA,curcumin downregulates the protein expression of FABP5 by approximately 50%. Interestingly, we have observed that curcumin sensitizes MDA-MB231 cells to retinoic acid mediated growth suppression by using MTT assay. The combination of curcumin with RA suppresses mammary carcinoma growth of MDA-MB231 cells by 30-40% in comparison to curcumin alone. Thus, altering the expression level of CRABPII and FABP5 by curcumin diverts the RA signalling from the proliferative FABP5/PPARβ/δ pathway to the growth inhibitory CRABPII/RAR path and sensitizes MDA-MB231 cells to RA-mediated growth suppression.

Citation Format: Padmamalini Thulasiraman, Daniel McAndrews. Altering the expression levels of CRABPII and FABP5 by curcumin sensitizes MDA-MB231 mammary carcinoma cells to retinoic acid mediated growth suppression. [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 3566. doi:10.1158/1538-7445.AM2013-3566
Abstract 357: A glial origin for medulloblastoma and inhibition of MYCN stabilization.
Authors: Bolin Sara , Lau Jasmine , Savov Vasil , Chen Justin , Persson Anders I. , Hede Sanna-Maria , Weiss William A. , Swartling Fredrik J.
Published: August 2014

The origin of MYCN-driven medulloblastoma, a poor-prognosis childhood brain tumor is not known. We recently showed that MYCN could generate tumors with high penetrance from a glutamate transporter (GLT1) promoter in a transgenic model (GTML) of medulloblastoma. By using Rosa26-lsl-LacZ reporters we also showed that GLT1-positive neural stem cells (NSCs) from normal brain represent putative cells of tumor origin.

GTML mice generate aggressive MYCN-driven medulloblastoma 2-3 months after birth. BrdU-labeling of 3-week-old GTML mice detected significantly more proliferation in thalamic forebrain cells and of BrdU/BLBP-double positive Bergmann glia in the cerebellum as compared to corresponding normal brain. Retroviral tagging with the RCAS/tv-a system marked BLBP- or GFAP-positive tumor initiating cells and expression analysis could further determine genetic profiles of tumor origin.

Interestingly, MYCN levels and early proliferation of brain tumors could be reduced by specific inhibition of CDK2 or by using the bromodomain inhibitor JQ1. Both treatment strategies induced tumor cell senescence as seen by SA-beta-gal activity and by downregulated Lamin B1. Our results propose a radial glial or a Bergmann glial origin for MYCN-driven medulloblastoma and further suggest ways to inhibit tumor growth by repressing MYCN stabilization.

Citation Format: Sara Bolin, Jasmine Lau, Vasil Savov, Justin Chen, Anders I. Persson, Sanna-Maria Hede, William A. Weiss, Fredrik J. Swartling. A glial origin for medulloblastoma and inhibition of MYCN stabilization. [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 357. doi:10.1158/1538-7445.AM2013-357
Abstract 3574: Studies of castrate resistant 22Rv1 cells identifies AR regulated interrelated networks of transcription factors, co-regulators, chromatin, and nuclear scaffolding proteins.
Authors: Mudryj Maria , Libertini Stephen J. , Lombard Alan P.
Published: August 2014

Prostate cancer development, progression and acquisition of castrate resistance are reliant on the activity of the androgen receptor (AR), a transcription factor that governs the proliferation of prostate cancer cells. Multiple studies have focused on the principle components that are critical for cell cycle transversal and these studies have identified members of the E2F/RB family, c-Myc, cyclins and cyclin dependent kinase inhibitors as key proteins that are instrumental in prostate cell proliferation and development of castrate resistance. But the mechanism by which the AR dominates this process is unclear. To identify the link between the AR and cell cycle control we used 22Rv1 cells which are castrate resistant due to the expression of low molecular weight AR forms that are missing the ligand binding domain. However, a siRNA mediated decrease in AR expression induces a growth arrest confirming that proliferation is AR dependent. RNA-seq analysis of gene expression at castrate levels of androgen and following AR ablation identified transcripts that were AR dependent. This methodology reduced the number of AR regulated transcripts, by excluding transcripts regulated by super-physiological levels of androgens. The AR regulated transcripts included previously identified genes (PMEPA1, C1orf116, PCDH7, APP) including NFAT a gene shown to be regulated by a low molecular weight AR isoform. The analysis also revealed that interrelated networks of transcription factors and co-factors were AR transactivated or repressed. These included proteins such as the LBR, LMNB, TMPO and SATB1 that do not directly promote transcription, but rather link chromatin to the nuclear membrane or scaffolding, suggesting that the AR may modulate gene expression through epigenetics mechanisms. Network analysis showed connections between these proteins and cell cycle components including E2Fs and Myc where a number of the regulated transcripts are known E2F or Myc targets. In addition, this analysis identified a number of non-coding RNAs; some that have been previously described and some that have yet to be annotated. qPCR studies found that a number of the transcripts regulated in 22Rv1 cells are also AR regulated in LNCaP cells. Coupled with ChIP-seq data, the study characterizes the link between the AR and the cell cycle machinery and chromatin modulating proteins.

Citation Format: Maria Mudryj, Stephen J. Libertini, Alan P. Lombard. Studies of castrate resistant 22Rv1 cells identifies AR regulated interrelated networks of transcription factors, co-regulators, chromatin, and nuclear scaffolding 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 3574. doi:10.1158/1538-7445.AM2013-3574
Abstract 3576: USP22 modulates AR activity to critically regulate prostate cancer progression.
Authors: Schrecengost Randy , Dean Jeffry , Stanek Tim , Birbe Ruth , Hicks Jessica , Visakorpi Tapio , DeMarzo Angelo , McMahon Steve , Knudsen Karen
Published: August 2014

Recently, the deubiquitylase Ubiquitin-specific protease 22 (USP22) was identified as a member of the 11 gene ‘death-from-cancer’ signature, which can predict poor response to therapy and/or propensity toward metastasis of multiple tumor types, including breast and prostate. However, the mechanism for how USP22 impacts cancer is currently unknown. Our new data implicate a specific role for USP22 in hormone-dependent cancers, especially prostate cancer (PCa) where USP22 expression is elevated in primary and metastatic PCa. USP22 has an established role in regulating oncogenic c-Myc activity as it is recruited by c-Myc for transcriptional activation through deubiquitylation of histones, and is necessary for c-Myc-mediated cell transformation. Similarly, our data in PCa cells demonstrates that USP22 controls c-Myc activity but does not affect expression levels.

Additional data has also identified USP22 as a critical effector of androgen receptor (AR) levels and output. This is of great clinical relevance since PCa is intricately dependent on AR signaling for disease initiation and progression to castrate resistant disease (CRPC). First, USP22 overexpression in hormone-dependent and CRPC cell lines increased AR protein expression and activity, but did not perturb transcript. Second, in the absence of ligand, USP22 upregulation resulted in enhanced AR recruitment to target genes, as determined by chromatin immunoprecipitation, which corresponded with significant enhancement of cell proliferation and BrdU incorporation. Third, USP22 depletion resulted in attenuated AR activity and caused a significant reduction in AR protein levels that could be attributed to protein stability. Importantly, in the CRPC setting, USP22 depletion dramatically inhibited in vivo tumor growth while expression correlated with decreased time for tumor regression.

In sum, the data suggest that USP22 upregulation is sufficient for aberrant c-Myc activity, altered AR expression and activity, and establishment of a CRPC phenotype. We propose that modulation of UPS22 expression and/or activity may present a novel platform to achieve combinatorial suppression of AR and c-Myc function, and therefore could be potentially developed as a novel approach for treatment of PCa.

Citation Format: Randy Schrecengost, Jeffry Dean, Tim Stanek, Ruth Birbe, Jessica Hicks, Tapio Visakorpi, Angelo DeMarzo, Steve McMahon, Karen Knudsen. USP22 modulates AR activity to critically regulate prostate cancer progression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3576. doi:10.1158/1538-7445.AM2013-3576
Abstract 3579: Mechanistic roles of cytochrome P4501A1 and 1A2 in lung carcinogenesis mediated by polycyclyc aromatic hydrocarbons: Implications for lung cancer in humans .
Authors: Moorthy Bhagavatula , Zhou Guodong , Wang Lihua , Jiang Weiwu
Published: August 2014

Humans are frequently exposed to polycyclic aromatic hydrocarbons (PAHs). Cytochrome P4501A (CYP1A) enzymes play important roles in the activation of PAHs such as 3-methylcholanthrene (MC) to DNA-binding metabolites, which in turn mediate carcinogenesis in target organs such as lung, breast, and skin. In this study, we tested the hypothesis that CYP1A1 and 1A2 play mechanistic roles in PAH-mediated carcinogenesis and tumorigenesis. Eight week-old female wild type (WT) (A/J) mice or mice lacking the gene for CYP1A1 or CYP1A2 on the A/J background were treated with a single dose of MC (40 μmol/kg), benzo[a]pyrene (BP), or vehicle (corn oil), and liver and lung tumors were studied after 28 weeks. While 100% of WT or Cyp1a2-null mice exposed to MC showed lung tumors after 28 weeks, about 80% of the Cyp1a1-null mice showed lung tumors. However, there were striking differences in the Cyp1a1-null and Cyp1a2-null mice in regard to lung tumor multiplicities. The WT mice treated with MC had about 15 lung tumors/animal. On the other hand, the Cyp1a2-null mice displayed about 40 lung tumors/animal, while the Cyp1a1-null mice showed about 2-3 tumors/mouse. Although BP was less potent in inducing lung tumors in the WT mice compared to MC, it was similar to MC In that tumors were suppressed in the Cyp1a1-null mice and augmented in the Cyp1a2-null mice. DNA adduct studies at early time points showed increased MC or BP adducts in lungs of Cyp1a2-null mice compared to WT mice, and decreased adduct formation in the Cyp1a1-null mice, supporting the hypothesis that DNA adducts are early biomarkers of PAH-mediated carcinogenesis. Immunohistochemical studies showed that CYP1A1 was overexpressed in the tumorous portions of the lung in the Cyp1a2-null or WT mice, compared to non-tumorous regions. These results suggest that CYP1A1 contributes to the formation of tumorigenesis by PAHs, while CYP1A2 protects against carcinogenesis mediated by PAHs, presumably through it role in PAH detoxification. In conclusion, our results strongly suggest that CYP1A1 and 1A2 could be novel candidates for cancer prevention and therapy though either inhibition of CYP1A1 or induction of CYP1A2. (Supported by NIH grant ES009132.)

Citation Format: Bhagavatula Moorthy, Guodong Zhou, Lihua Wang, Weiwu Jiang. Mechanistic roles of cytochrome P4501A1 and 1A2 in lung carcinogenesis mediated by polycyclyc aromatic hydrocarbons: Implications for lung cancer in humans . [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 3579. doi:10.1158/1538-7445.AM2013-3579
Abstract 358: Nf1 inactivation in NG2-cells is not sufficient for murine optic glioma formation.
Authors: Solga Anne C. , Gianino Scott M. , Gutmann David H.
Published: August 2014

Individuals with the tumor predisposition syndrome, neurofibromatosis 1 (NF1), are prone to development of low-grade astrocytomas (gliomas). These tumors frequently include optic pathway gliomas predominantly arising in young children. We have previously developed several Nf1 genetically-engineered mouse (GEM) strains that form optic gliomas similar to those that occur in children with NF1. However, in the optic nerve, there are two types of potential neuroglial progenitors, GFAP+ and NG2+ cells. This latter population has been shown to represent a potential cell of origin for rat malignant gliomas, suggesting that NG2+ progenitors may represent the initiating cell for Nf1 optic glioma. In this study, we employed a complementary series of in vitro and in vivo approaches to determine whether NG2+ cells could give rise to Nf1 optic glioma. First, we demonstrate that Nf1 loss in NG2+ cells does not increase glial cell proliferation in vitro. Second, NG2-Cre-expressing cells give rise to all three macroglial lineages (astrocytes, NG2+ cells, and oligodendrocytes) in vivo, similar to GFAP-Cre-expressing cells that drive Nf1 optic glioma formation. Third, in striking contrast to the GFAP-Cre strain, Nf1 loss in NG2+ progenitor cells in vivo is insufficient for optic gliomagenesis. Together, these data exclude NG2+ cells as the likely cell of origin for NF1-associated optic glioma and establish a model of gliomagenesis in which Nf1 loss occurs in specific neuroglial progenitors during embryonic development.

Citation Format: Anne C. Solga, Scott M. Gianino, David H. Gutmann. Nf1 inactivation in NG2-cells is not sufficient for murine optic glioma formation. [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 358. doi:10.1158/1538-7445.AM2013-358
Abstract 3581: Impact of Nrf2 on the development of ethyl carbamate/ butylated hydroxytoluene-induced lung tumorigenesis in mice.
Authors: Wu Tien-Yuan , Khor Tin Oo , Cheung Ka-Lung , Kong Ah-Ng
Published: August 2014

Chronic inflammation has been linked to the development of various types of cancers and has been recently recognized as the seventh hallmark of cancer. Accumulating evidence suggests that Nrf2 plays a pivotal role in protection against oxidative tissue damage and inflammation. Previous findings from ours as well as other laboratories have demonstrated that Nrf2 possesses the protection effects in the inflammation-associated carcinogenesis in preclinical models. The aim of the present study is to investigate the role of Nrf2 in butylated hydroxytoluene (BHT)-induced pulmonary inflammation and BHT-urethane/ethyl carbamate (EC) induced two-stage lung carcinogenesis. Nrf2 deficient mice showed an increased susceptibility to BHT-induced pulmonary inflammation, whereas Nrf2 WT mice have higher antioxidant proteins level and lower pro-inflammatory markers. Although lung inflammation was slightly more severe in Nrf2KO mice as compared to their wildtype counterpart, the tumor incidence and tumor multiplicity were found to be significantly lower in Nrf2KO mice treated with EC-BHT. Tumor multiplicity was also lower in Nrf2KO mice treated with EC alone. In summary, on one hand, Nrf2 is required to dampen inflammation, but Nrf2 may be disadvantage in EC or BHT-EC mediated lung tumorigenesis.

Citation Format: Tien-Yuan Wu, Tin Oo Khor, Ka-Lung Cheung, Ah-Ng Kong. Impact of Nrf2 on the development of ethyl carbamate/ butylated hydroxytoluene-induced lung tumorigenesis in mice. [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 3581. doi:10.1158/1538-7445.AM2013-3581
Abstract 3584: Ethanol and aging promote pathogenesis of hepatocellular carcinoma in mice.
Authors: George Joseph , Tsuchishima Mutsumi , Toshikuni Nobuyuki , Saito Takashi , Tsutsumi Mikihiro
Published: August 2014

Background & Aims: Chronic intake of alcohol increases the risk of gastrointestinal and hepatic carcinogenesis. The present study was focused to investigate the incidence and mechanism of pathogenesis of hepatocellular carcinoma (HCC) during aging and chronic ingestion of alcohol without any additional hepatic injury.

Methods: Ethanol was administered to ICR male mice through drinking water for 70 weeks at concentrations of 5% (first week), 10% (next 8 weeks), and 15% thereafter. The animals were sacrificed at 60 weeks and 70 weeks, the livers were examined for hepatic tumors, and evaluated for foci of cellular alteration. Immunohistochemical staining was performed in the liver sections for cytochrome P4502E1 (CYP2E1), 4-hydroxy-nonenal, and proto-oncogene, c-Myc

Results: At 60th week, 40% of mice in the ethanol group had visible white nodules (5-10 mm) in the liver, but not in control mice. At 70th week, several larger nodules (5-22 mm) were present in the livers of 50% mice in ethanol group. In control group, one mouse developed a single nodule. All nodules were histologically trabecular HCC composed of eosinophilic and vacuolated cells. In the livers of both control and ethanol group, several foci with cellular alteration were present, which were significantly higher in ethanol group. Staining for CYP2E1, 4-hydroxy-nonenal and c-Myc depicted marked upregulation of all these molecules in the foci of cellular alteration.

Conclusions: Our data demonstrated that upregulation of CYP2E1 and subsequent production of reactive oxygen species along with the persistent expression of c-Myc play a significant role in the pathogenesis of HCC during chronic ingestion of ethanol. Furthermore, aging is also a risk factor for development of HCC.

* Presenting author

Citation Format: Joseph George, Mutsumi Tsuchishima, Nobuyuki Toshikuni, Takashi Saito, Mikihiro Tsutsumi. Ethanol and aging promote pathogenesis of hepatocellular carcinoma in mice. [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 3584. doi:10.1158/1538-7445.AM2013-3584
Abstract 3586: Benzopyrene diol epoxide attenuates p34cdc2 and inhibits cell growth: role of p53.
Authors: Mukherjee Jagat J. , Kumar Subodh
Published: August 2014

Our previous findings demonstrated that DNA damage by polynuclear aromatic hydrocarbons (PAHs) triggers cellular protective response of cell growth inhibition (G1-S cell cycle arrest and inhibition of DNA synthesis) in human fibroblast associated with accumulation of p53 protein, a known cell growth inhibitory transcription factor. Here we report that in different cell lines BPDE treatment (ultimate carcinogenic metabolite of the PAH benzo[a]pyrene) triggers variable extent of cell growth inhibition which do not correspond to the extent of increased p53 accumulation as we observed. We also observed that BPDE treatment of cells significantly down-regulates expression of p34cdc2, a known cell cycle activating protein. Although the role of cdc2 down-regulation in inhibition of cell cycle progression is well known, to the best of our knowledge cdc2 down-regulation in response to cellular insult by PAHs has not been reported. Unlike p53 accumulation there is correspondence between extent of cell growth inhibition and the extent of cdc2 down-regulation by BPDE in different cell lines. Interestingly, BPDE-induced cdc2 down-regulation is observed to be p53 dependent although there is lack of correspondence between the extent of p53 accumulation and cdc2 down-regulation. However, extent of BPDE induced cdc2 down-regulation was observed to have correspondence with the extent of accumulation of cell cycle inhibitor protein p21 (transactivation product of p53) in different cell lines. These findings may have an implication that cell growth inhibition in response to DNA damaging PAHs may involve down-regulation of cdc2 protein mediated by p53 activation (transactivation ability), and the extent of p53 accumulation is not the determining factor in this regard.

Citation Format: Jagat J. Mukherjee, Subodh Kumar. Benzopyrene diol epoxide attenuates p34cdc2 and inhibits cell growth: role of p53. [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 3586. doi:10.1158/1538-7445.AM2013-3586