Background: Previous studies have demonstrated that proliferation- and ER-associated gene expression shows a time-dependent interaction with risk of recurrence. Breast Cancer Index (BCI) is a gene expression-based test that integrates biomarker panels of both proliferation (Molecular Grade Index, MGI), and endocrine response (HOXB13/IL17BR, H/I). BCI has been validated as a significant and independent prognostic factor both for risk of overall (0-10y) and late (>5y) distant recurrence and is predictive of extended endocrine benefit in patients with early-stage, hormone receptor-positive (HR+) breast cancer. In this study, correlative analyses were performed to evaluate molecular measures of proliferation and ER signaling by MGI and H/I that underly recurrence risk across clinical categories in patients receiving BCI testing as part of routine care. Methods: Analysis was performed using the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database which contains >50 data elements including clinicopathologic and molecular variables from 19,126 clinical cases submitted for BCI testing. Descriptive analyses assessed the distribution of MGI by H/I categories based on time of testing or BCI intervention point (time of diagnosis <1y for early recurrence vs 4-7y post diagnosis for late recurrence), lymph node status (N0 vs. N+), age (<50y vs. ≥50y), tumor size (T1-T3), and grade (1-3) to understand the molecular features that may be associated with recurrence in HR+ disease. Results: Analysis included 18,853 patients (88% ≥50y, 73% N0, 70% pT1, 51% grade 2). Comparative analysis of patients tested with BCI at <1y vs. those recurrence-free and tested at 4-7y post diagnosis showed a similar proportion of patients in the H/I categories (H/I-High: 44%1y, 43% 4-7y, P=0.510). An increased proportion of MGI-High was observed in 4-7y (61%) vs. 1y (53%) (P<0.001). The distribution of MGI categories within H/I-Low and High subsets was also similar based nodal status (N0 vs. N+), age (<50y vs. ≥50y), and tumor size. However, H/I status was inversely proportional to tumor grade (P<0.001): the proportion of H/I-Low decreased with increasing grade (Grade 1: 70%, 2: 59%, 3: 36%), whereas the proportion of H/I-High patients increased (Grade 1: 30%, 2: 41%, 3: 64%). In the H/I-Low subset, as grade increased, the proportion of MGI-Low patients decreased (1: 45%, 2: 23%, 3: 5%), while MGI-High remained relatively consistent across grade (1: 25%, 2: 36%, 3: 31%). In H/I-High patients, MGI-High increased as grade increased (1: 11%, 2: 26%, 3: 59%). Conclusion: BCI functional characterization using MGI for tumor proliferation and H/I for estrogen signaling in this large-scale analysis showed that over half (59%,1y vs. 67%, 4-7y) of endocrine responsive tumors (H/I-High) were also highly proliferative (MGI-High) irrespective of time of testing. Results showed that tumor grade correlated with MGI and H/I status, indicating that a subset of high-grade tumors were highly proliferative as well as endocrine responsive. These findings suggest that proliferation and endocrine signaling are combinatorial molecular drivers of recurrences in HR+ breast cancer. Table 1.Biomarker categorization by H/I and MGI status by time of testing, nodal status, age, tumor size, and grade.H/I-LowH/I-HighPatientsNMGI-Low (%)MGI-High (%)MGI-Low (%)MGI-High (%)Time of testing<1y1278282718264-7y1305725321429Nodal StatusN0950227311428N+344222311631Age<50y475824361129≥50y1409526301529Tumor SizeT1464930311524T2182619321435T319927311527Grade1224245251911239812336152631530531559 Citation Format: Reshma Mahtani, Yuan Yuan, Kari B Wisinski, Jay Morris, Max Salganik, Yi Zhang, Catherine A Schnabel, Vk Gadi. Breast cancer index and assessment of tumor proliferation by molecular grade index (MGI) within distinct HOXB13/IL17BR (H/I) subsets [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD9-09.

3551 Background: Agents targeting the angiogenic pathway have been a cornerstone therapy in mCRC. In chemo-refractory mCRC, RGF, an oral multikinase inhibitor with considerable angiogenic inhibition, has shown modest effects on survival. We reported that autophagy modulation using the autophagy inhibitor, HCQ, enhances the anti-cancer activity of the histone deacetylase inhibitor, VOR, via ubiquitinated protein accumulation in CRC. A phase 1b study confirmed VOR/HCQ is active and tolerated in refractory mCRC. We conducted a prospective randomized study to evaluate efficacy of VOR/HCQ vs RGF in mCRC patients (NCT02316340) and report a planned interim analysis. Methods: Randomized, controlled trial of VOR 400 mg and HCQ 600 mg PO daily vs RGF 160 mg PO daily (3 weeks on, 1 week off), Q4weeks, in advanced CRC patients. Crossover was optional after first progression. A total of 76 patients are planned. Primary endpoint: mPFS. Secondary endpoints: mOS; adverse events (NCI-CTCAEv3.0); PD analysis: 27-plex Human Cytokine Array, NGS analysis (Guardant Health) on cell-free, ctDNA. Results: At interim analysis, n = 42 patients enrolled from 2/2015-10/2017: n = 20 VOR/HCQ (5 crossed to RGF), n = 22 RGF (13 crossed to VOR/HCQ). 38 patients evaluable (at least C1 completed). Median age 58.4, 40% NH vs 60% H. mPFS on first arm: 1.90 mo VOR/HCQ vs 4.35 mo RGF [p = 0.032, HR: 2.277]. mOS: 6.77 mo VOR/HCQ vs 7.23 mo RGF [p = 0.90, HR: 1.05]. Grade 3/4 AEs (see table). In both arms, there was trend towards decreased IL-1b, IL-2, IL-6, IL-10, TNFα, IFNγ but an increase in GM-CSF after treatment. Responders (4+ cycles) had lower baseline Max MAF versus nonresponders for both arms. In responders, there was trend toward a decrease in Max MAF at C2 and then increase at progression. Conclusions: VOR/HCQ did not improve survival when compared to RGF. VOR/HCQ has a favorable safety profile, but further planned subgroup analysis is pending to identify biomarkers of efficacy in responders. Clinical trial information: NCT02316340. [Table: see text]

Numerous scientific experiments have been conducted in space. However, the precise mechanisms mediating successful human body adaption to the hostile space environment are still not delineated. The cost and logistic challenges of sending biological payloads to International Space Station are forcing scientists to find alternative research platforms. In this study, we investigated whether brief exposure to microgravity during the suborbital flight aboard Blue Origin’s New Shepard rocket modulated the behavior of the gravity-sensitive murine T cells. We assessed the effect of suborbital environment on different T cell subsets, activation markers, functionality, and cytokine secretion capabilities. Thus, to optimize the potential response of T cells, we cultured them in interleukin IL-2 alone or combined with IL-12. We found that exposure to microgravity decreased the expression of T cells with CD4+ cells being more sensitive to suborbital flight as compared to CD8+ cells. Our data indicate that the functional capabilities of flown T cells were reduced. Also, our findings suggest that supplementing cells with IL-2 and IL-12 cytokines may restore microgravity-mediated cellular alterations. Finally, our study provides insights on the microgravity effect on the murine T cells by utilizing a novel suborbital research platform.

BACKGROUND/AIM:Aerial parts and seeds of the neem tree (Azadirachta indica) have long been used in traditional medicine such as Ayurveda for health-related purposes. Our interest in neem bioactives lies in their potential use as standalone anticancer agents, or as adjuvants to standard therapy. The aim of the present study was to explore a supercritical CO2 extract (SCNE) of neem leaf and a prominent liminoid in neem leaf, nimbolide, for epigenetic activity.MATERIALS AND METHODS:Human colorectal cancer cell lines (HCT116 and HT29) were cultured for 48 h in the presence of neem extract or nimbolide and evaluated for growth inhibition and evidence of suppression of histone deacetylation and DNA methylation.RESULTS:Both SCNE and nimbolide suppressed the proliferation of colon cancer cells by inducing epigenetic modifications.CONCLUSION:Neem leaf contains bioactive constituents which modify epigenetic activity.

A growing body of research suggests that a diet rich in fruits and vegetables could not only reduce the risk of developing cancer, but also affect the treatment outcome. One common mechanism could involve epigenetic modulation. The precise mechanisms mediating epigenetics, however, are not well delineated. In this chapter, we provide a comprehensive overview of food-derived natural compounds with epigenetic activity such as alterations of DNA methylation, histone modifications, chromatin architecture, and small noncoding RNAs. Specifically, we discuss the chemopreventive mechanisms by which natural compounds alter the cancer epigenome and thereby reverse gene silencing. In addition, we present our perspective on natural epigenetic compounds as adjuvants in cancer prevention therapy. Finally, we conclude our chapter by proposing an epigenetic diet mainly designed for those subjects diagnosed with known cancers evolving from silenced tumor-suppressor genes.

A growing body of research suggests that a diet rich in fruits and vegetables could not only reduce the risk of developing cancer, but also affect the treatment outcome. One common mechanism could involve epigenetic modulation. The precise mechanisms mediating epigenetics, however, are not well delineated. In this chapter, we provide a comprehensive overview of food-derived natural compounds with epigenetic activity such as alterations of DNA methylation, histone modifications, chromatin architecture, and small noncoding RNAs. Specifically, we discuss the chemopreventive mechanisms by which natural compounds alter the cancer epigenome and thereby reverse gene silencing. In addition, we present our perspective on natural epigenetic compounds as adjuvants in cancer prevention therapy. Finally, we conclude our chapter by proposing an epigenetic diet mainly designed for those subjects diagnosed with known cancers evolving from silenced tumor-suppressor genes.

Oral squamous cell carcinoma (OSCC) is a deadly disease that comprises 60% of all head and neck squamous cell cancers. The leaves of the Neem tree (Azadirachta indica) have been used in traditional Ayurvedic medicine for centuries to treat numerous oral maladies and are known to have significant anti-inflammatory properties. We hypothesize that a highly pure super critical CO2 Neem leaf extract (SCNE) prevents initiation and progression of OSCC via downregulation of intra-tumor pro-inflammatory pathways, which promote tumorigenesis. Hence, we investigated the anticancer effects of SCNE using in vitro and in vivo platforms. OSCC cell lines (SCC4, Cal27, and HSC3) were treated with SCNE while inflammation, proliferation, and migration were analyzed over time. SCNE treatment significantly inhibited OSCC cell proliferation and migration and reduced MMP activity in vitro, suggesting its potential to inhibit tumor growth and metastasis. The preventive effects of SCNE in ectopic xenograft and 4NQO-1 (4-Nitroquinoline-1-oxide) carcinogen-induced mouse models of OSCC were also evaluated. Indeed, xenografted nude mice showed significant reduction of OSCC tumor volumes. Likewise, SCNE significantly reduced the incidence of tongue dysplasia in the 4NQO-1 OSCC initiation model. In both OSCC animal models, SCNE significantly depressed circulating pro-cancer inflammatory cytokines (host and tumor-secreted) including NFkB, COX2, IL-1, IL-6, TNFα, and IFNγ. In addition, we demonstrate that SCNE downregulates STAT3 and AKT expression and activity in vitro. We also demonstrate that the primary active component, nimbolide (NIM), has significant anticancer activity in established OSCC xenografts. Lastly, we show that SCNE induces an M1 phenotype in tumor associated macrophages (TAMS) in vivo. Taken together, these data strongly support SCNE as means of preventing OSCC via downregulation of pro-cancer inflammatory cascades and NIM as a potential new therapy for existing OSCC.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer death in men and women in the United States. Anti‐inflammatory blockade has been proven to be a promising avenue of colorectal cancer prevention. However, NSAIDs while effective in curbing CRC risk are too toxic for long‐term use in cancer prevention. The Neem tree (Azadirachta indica) is rich in liminoid terpenoids, collectively known as azadiractoids and has been shown to have anti‐inflammatory effects. To explore a role of neem in CRC, human colon cancer cell lines HCT116 and HT29 cells were treated with purified Super Critical Neem Extract (SCNE) or the neem liminoid, nimbolide. SCNE treatment resulted in a dose dependent inhibition of CRC cell proliferation and an increase in apoptosis. Treatment with SCNE and nimbolide decreased the expression of transcriptional factors, STAT3 and NF‐κB which plays a major role in gene regulation of multiple cellular processes. Protein expression of COX1, IL‐6, and TNF‐α were decreased on treatment with SCNE in CRC cells. Western blots and Zymogram assays results revealed anti‐invasive effect by decreased expression of MMP2 and MMP9 proteins in CRC cells. Overall, these data confirm a potential anti‐cancer effect of SCNE, reducing cell proliferation, inflammation, migration, and invasion in human colon cancer cells. Confirming these indications, we found that treatment of mice bearing HT29 and HCT116 xenografted tumors exhibited striking inhibition of colon tumor growth. Clearly we must explore the effect of neem in preclinical animal models for anti‐cancer therapy.

Abstract Inflammatory bowel disease (IBD), encompassing both ulcerative colitis and Crohn's disease, is a high risk factor for colorectal cancer (CRC). It is a lifelong inflammation-driven disorder with a poorly defined etiology contributing to limitations in available treatment options. A north to south gradient is associated with IBD incidence rate and recurrence, implicating low vitamin D level as a risk factor. Colitis and CRC patients have reduced VDR expression indicating VDR impairment in the etiology of colitis and its progression to CRC. VDR and RXRα heterodimerization is required to regulate inflammation and proliferation. Our group has shown that RXRα is also diminished in tumors from CRC patients. These led us to ask how an inflammatory microenvironment induces VDR/RXRα silencing. We hypothesize that in an inflammatory microenvironment promoter methylation drives VDR/RXRα silencing in chronic colitis and colitis-associated cancer (CAC), resulting in dysregulated proliferation and chronic inflammatory setting. Using dextran sodium sulfate (DSS) mouse models of colitis, we induced intestinal inflammation in mice with (1) fully functional VDR and RXRα and in mice that are (2) genetically haploinsufficient either in VDR or RXRα. At termination, we measured intestinal permeability using fluorescein isothiocyanate-labeled dextran and profiled serum cytokine/chemokine concentration using the Bio-Plex Pro mouse cytokine 23-plex assay kit (Bio-Rad, CA). Colon swiss rolls were made for histopathological evaluation and immunohistochemistry. To determine the ability of a pro-inflammatory cytokine elevated in colitis in promoting aberrant proliferation, we treated colon cancer cell lines (SW480 and LOVO) with Interleukin-6 (IL6). We monitored cell proliferation with the Incucyte Zoom System (Essen BioScience, MI). In this study, we report that (1) loss of VDR and RXRα elicits a pro-inflammatory chemokine/cytokine signature that exacerbates disease in DSS mouse model of colitis in part by increasing intestinal permeability and (2) IL6 promotes proliferation of colon cancer cells, suggesting that sustained IL6 exposure of epithelial cells in an inflamed colon can potentially drive tumorigenesis. We are currently investigating the epigenetic mechanisms of VDR and RXRα suppression. By understanding mechanisms underlying silencing of key inflammatory regulators, this project in the long-term can (1) contribute to target(s) identification for IBD and CAC prevention/therapy and (2) provide more evidence for the use epigenetic modulators (alone or in combination with standard Rx) for IBD, colon cancer, and other inflammation-driven diseases to overcome non-responsiveness to current therapies. Inflammatory bowel disease (IBD), encompassing both ulcerative colitis and Crohn's disease, is a high risk factor for colorectal cancer (CRC). It is a lifelong inflammation-driven disorder with a poorly defined etiology contributing to limitations in available treatment options. A north to south gradient is associated with IBD incidence rate and recurrence, implicating low vitamin D level as a risk factor. Colitis and CRC patients have reduced VDR expression indicating VDR impairment in the etiology of colitis and its progression to CRC. VDR and RXRα heterodimerization is required to regulate inflammation and proliferation. Our group has shown that RXRα is also diminished in tumors from CRC patients. These led us to ask how an inflammatory microenvironment induces VDR/RXRα silencing. We hypothesize that in an inflammatory microenvironment promoter methylation drives VDR/RXRα silencing in chronic colitis and colitis-associated cancer (CAC), resulting in dysregulated proliferation and chronic inflammatory setting. Using dextran sodium sulfate (DSS) mouse models of colitis, we induced intestinal inflammation in mice with (1) fully functional VDR and RXRα and in mice that are (2) genetically haploinsufficient either in VDR or RXRα. At termination, we measured intestinal permeability using fluorescein isothiocyanate-labeled dextran and profiled serum cytokine/chemokine concentration using the Bio-Plex Pro mouse cytokine 23-plex assay kit (Bio-Rad, CA). Colon swiss rolls were made for histopathological evaluation and immunohistochemistry. To determine the ability of a pro-inflammatory cytokine elevated in colitis in promoting aberrant proliferation, we treated colon cancer cell lines (SW480 and LOVO) with Interleukin-6 (IL6). We monitored cell proliferation with the Incucyte Zoom System (Essen BioScience, MI). In this study, we report that (1) loss of VDR and RXRα elicits a pro-inflammatory chemokine/cytokine signature that exacerbates disease in DSS mouse model of colitis in part by increasing intestinal permeability and (2) IL6 promotes proliferation of colon cancer cells, suggesting that sustained IL6 exposure of epithelial cells in an inflamed colon can potentially drive tumorigenesis. We are currently investigating the epigenetic mechanisms of VDR and RXRα suppression. By understanding mechanisms underlying silencing of key inflammatory regulators, this project in the long-term can (1) contribute to target(s) identification for IBD and CAC prevention/therapy and (2) provide more evidence for the use epigenetic modulators (alone or in combination with standard Rx) for IBD, colon cancer, and other inflammation-driven diseases to overcome non-responsiveness to current therapies. Citation Format: April B. Cabang, Jay L. Morris, Michael J. Wargovich. Determining the role of Vitamin D Receptor (VDR) and Retinoid X Receptor Alpha (RXRα) in colitis. [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer: From Initiation to Outcomes; 2016 Sep 17-20; Tampa, FL. Philadelphia (PA): AACR; Cancer Res 2017;77(3 Suppl):Abstract nr A03.

Colorectal cancer (CRC) remains one of the most commonly diagnosed cancers and the 3rd leading cause of cancer-related mortality. The emergence of drug resistance poses a major challenge in CRC care or treatment. This can be addressed by determining cancer mechanisms, discovery of druggable targets, and development of new drugs. In search for novel agents, aquatic microorganisms offer a vastly untapped pharmacological source that can be developed for cancer therapeutics. In this study, we characterized the anti-colorectal cancer potential of euglenophycin, a microalgal toxin from Euglena sanguinea. The toxin (49.1-114.6 μM) demonstrated cytotoxic, anti-proliferative, anti-clonogenic, and anti-migration effects against HCT116, HT29, and SW620 CRC cells. We identified G1 cell cycle arrest and cell type - dependent modulation of autophagy as mechanisms of growth inhibition. We validated euglenophycin's anti-tumorigenic activity in vivo using CRL:Nu(NCr)Foxn1nu athymic nude mouse CRC xenograft models. Intraperitoneal toxin administration (100 mg/kg; 5 days) decreased HCT116 and HT29 xenograft tumor volumes (n=10 each). Tumor inhibition was associated with reduced expression of autophagy negative regulator mechanistic target of rapamycin (mTOR) and decreased trend of serum pro-inflammatory cytokines. Together, these results provide compelling evidence that euglenophycin can be a promising anti-colorectal cancer agent targeting multiple cancer-promoting processes. Furthermore, this study supports expanding natural products drug discovery to freshwater niches as prospective sources of anti-cancer compounds.

The last decade has witnessed remarkable progress in the utilization of natural products for the prevention and treatment of human cancer. Many agents now in the pipeline for clinical trial testing have evolved from our understanding of how human nutritional patterns account for widespread differences in cancer risk. In this review, we have focused on many of these promising agents arguing that they may provide a new strategy for cancer control: natural products once thought to be only preventive in their mode of action now are being explored for efficacy in tandem with cancer therapeutics. Natural products may reduce off-target toxicity of therapeutics while making cancers more amenable to therapy. On the horizon is the use of certain natural products, in their own right, as mitigants of late-stage cancer, a new frontier for small-molecule natural product drug discovery.

Rapamycin inhibits mechanistic (or mammalian) target of rapamycin (mTOR) that promotes protein production in cells by facilitating ribosome biogenesis (RiBi) and eIF4E-mediated 5'cap mRNA translation. Chronic treatment with encapsulated rapamycin (eRapa) extended health and life span for wild-type and cancer-prone mice. Yet, the long-term consequences of chronic eRapa treatment are not known at the organ level. Here, we report our observations of chronic eRapa treatment on mTORC1 signaling and RiBi in mouse colon and visceral adipose. As expected, chronic eRapa treatment decreased detection of phosphorylated mTORC1/S6K substrate, ribosomal protein (rpS6) in colon and fat. However, in colon, contrary to expectations, there was an upregulation of 18S rRNA and some ribosomal protein genes (RPGs) suggesting increased RiBi. Among RPGs, eRapa increases rpl22l1 mRNA but not its paralog rpl22. Furthermore, there was an increase in the cap-binding protein, eIF4E relative to its repressor 4E-BP1 suggesting increased translation. By comparison, in fat, there was a decrease in the level of 18S rRNA (opposite to colon), while overall mRNAs encoding ribosomal protein genes appeared to increase, including rpl22, but not rpl22l1 (opposite to colon). In fat, there was a decrease in eIF4E relative to actin (opposite to colon) but also an increase in the eIF4E/4E-BP1 ratio likely due to reductions in 4E-BP1 at our lower eRapa dose (similar to colon). Thus, in contrast to predictions of decreased protein production seen in cell-based studies, we provide evidence that colon from chronically treated mice exhibited an adaptive 'pseudo-anabolic' state, which is only partially present in fat, which might relate to differing tissue levels of rapamycin, cell-type-specific responses, and/or strain differences.

Silencing of regulatory genes through hypermethylation of CpG islands is an important mechanism in tumorigenesis. In colon cancer, RXRα, an important dimerization partner with other nuclear transcription factors, is silenced through this mechanism. We previously found that colon tumors in ApcMin/+ mice had diminished levels of RXRα protein and expression levels of this gene were restored by treatment with a green tea intervention, due to reduced promoter methylation of RXRα. We hypothesized that CIMP+ cell lines, which epigenetically silence key regulatory genes would also evidence silencing of RXRα and EGCG treatment would restore its expression. We indeed found EGCG to restore RXRα activity levels in the human cell lines, in a dose dependent manner and reduced RXRα promoter methylation. EGCG induced methylation changes in several other colon cancer related genes but did not cause a decrease in global methylation. Numerous epidemiological reports have shown the benefits of green tea consumption in reducing colon cancer risk but to date no studies have shown that the risk reduction may be related to the epigenetic restoration by tea polyphenols. Our results show that EGCG modulates the reversal of gene silencing involved in colon carcinogenesis providing a possible avenue for colon cancer prevention and treatment.

Aerodigestive cancers are on an increasing level in both occurrence and mortality. A major cause in many of these cancers is disruption of the inflammatory pathway, leading to increased cell proliferation and epigenetic silencing of normal regulatory genes. Here, we review the research on several natural products: silibinin, silymarin, quercetin, neem and nimbolide, gingerol, epigallatecatechin-3- gallate, curcumin, genistein, and resveratrol conducted on aerodigestive cancers. These types of cancers are primarily those from oral cavity, esophagus/windpipe, stomach, small and large intestine, colon/rectum, and bile/pancreas tissues. We report on the utilization in vivo and in vitro systems to research these dose effects on the inflammatory and epigenetic pathway components within the aerodigestive cancer. To follow up on the basic research, we will discuss the remaining research questions and future directions involving these natural products as putative stand alone or in combination with clinical agents.

A lofty goal for many in agriculture is the attainment of global nutritional security. Balanced nutrition would help ensure every child an opportunity to thrive. Currently, cereal grains are used as the staple caloric source in most developing countries. Unfortunately, these grains are poor sources of essential minerals (such as iron, zinc and calcium) and vitamin A. Various methods are now being employed to augment these nutrient levels. Proper seed selection coupled with effective soil preparation can increase nutrient levels, while biotechnology approaches have also shown significant promise. While augmenting levels of these nutrients or removing substances that inhibit absorption are important first steps, the true litmus test is whether these higher levels translate into improved absorption and enhanced bioavailability. Utilizing animal models researchers can test the efficacy of foods before conducting the expensive and often controversial human feeding trails. In this review we go over the biofortification efforts that have been undertaken to improve iron, zinc, calcium, and vitamin A levels and to decrease antinutrient components. In addition, we discuss the research done to assess how these changes impact absorbability in humans. Lastly, we discuss the scientific and political issues surrounding implementation of these modifications.

Abstract Epigallocatechin gallate (EGCG), a major constituent of green tea, has been shown to exhibit antioxidant and antitumorigenic properties using in vitro and in vivo models of colon cancer and in small cohort studies of colorectal cancer patients. The development of colon cancer is influenced by both genetic and epigenetic factors, with increased risk associated with age, lifestyle, and environmental exposures. Thus, parsing the interactions of genetic components and epigenetic modulators of gene expression in colon cancer development and progression is essential. The mechanism by which EGCG exerts antitumorigenic activity against colon cancer has not been completely elucidated. This study investigates potential mechanism(s) by which EGCG inhibits proliferation of HCT-116 and HT-29 colon cancer cell lines, via epigenetic pathways. Briefly, HCT-116 and HT-29 cells were treated with EGCG (5-150 µM) and control drugs: 5-FU (50-200 µg/mL), 5-AZA (5 µM), SAHA (1-10 µM), and anacardic acid (10 µM) for 48-72 h. Cell proliferation (MTT), cell cycle and apoptosis (PI-FC and TUNEL), enzyme activity, gene and protein expression were measured. EGCG inhibited proliferation of HCT-116 and HT-29 by promoting S-phase cell cycle arrest and apoptosis. Expression and global enzyme activity of DNMTs (1, 3a, 3b), HDACs (1-4), and HATs (P300, PCAF, P400) were differentially expressed in both cell lines. A consistent upregulation of DNMT3b and downregulation of HDAC3 in both cell lines were observed. Global and gene-specific regulation of DNA methylation and histone acetylation by EGCG is under current study in our lab. The antiproliferative effects of EGCG can potentially be attributed to restoring normal global and gene-specific methylation/acetylation pattern in colon cancer cells by regulating DNMTs, HDACs, and HATs. This study provides evidence for the utilization of EGCG as a potential chemopreventive agent against colon cancer. Furthermore, identifying mechanisms by which EGCG overrides tumor-driven genetic deregulation to inhibit carcinogenesis expands our knowledge on pathways contributing to colon cancer and plausible targets for epigenetic therapy/prevention. This project is supported by NIH: RO1CA96694 and P30CA054174. Citation Format: April B. Cabang, Yuan Fang, Jay Morris, Michael J. Wargovich. Epigallocatechin gallate inhibits colon cancer cell proliferation by modulating epigenetic enzymes (DNMTs, HDACs, and HATs). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 410. doi:10.1158/1538-7445.AM2014-410