Intermittent Dosing Regimens of Aspirin and Naproxen Inhibit Azoxymethane-Induced Colon Adenoma Progression to Adenocarcinoma and Invasive Carcinoma

Chronic use of aspirin and related drugs to reduce cancer risk is limited by unwanted side effects. Thus, we assessed the efficacy associated with different dosing regimens of aspirin and naproxen. Azoxymethane (AOM)-rat colon cancer model was used to establish the pharmacodynamic efficacy of aspirin and naproxen under different dosing regimens. Colon tumors were induced in rats (36/group) by two weekly doses of AOM. At the early adenoma stage, rats were fed diets containing aspirin (700 and 1,400 ppm) or naproxen (200 and 400 ppm), either continuously, 1 week on/1 week off, or 3 weeks on/3 weeks off, or aspirin (2,800 ppm) 3 weeks on/3 weeks off. All rats were euthanized 48 weeks after AOM treatment and assessed for efficacy and biomarkers in tumor tissues. Administration of aspirin and naproxen produced no overt toxicities. Administration of different treatment regimens of both agents had significant inhibitory effects with clear dose-response effects. Aspirin suppressed colon adenocarcinoma multiplicity (both invasive and noninvasive) by 41% (P < 0.003) to 72% (P < 0.0001) and invasive colon adenocarcinomas by 67%-91% (P < 0.0001), depending on the treatment regimen. Naproxen doses of 200 and 400 ppm inhibited invasive adenocarcinoma multiplicity by 53%-88% (P < 0.0001), depending on the dosing regimen. Colonic tumor biomarker analysis revealed that proliferation (proliferating cell nuclear antigen and p21), apoptosis (p53 and Caspase-3), and proinflammatory mediators (IL1β and prostaglandin E₂) were significantly correlated with the tumor inhibitory effects of aspirin and naproxen. Overall, our results suggest that intermittent dosing regimens with aspirin or naproxen demonstrated significant efficacy on the progression of adenomas to adenocarcinomas, without gastrointestinal toxicities.

Abstract 4983: Intermittent dosing regimens of naproxen and aspirin inhibit azoxymethane-induced rat colon adenoma progression to adenocarcinoma and carcinoma invasion

Colorectal Cancer (CRC) is a major public health issue world-wide with an estimated 700,000 deaths annually. Adults 50 to 69 years of age considered high-risk for CRC can take low-dose Aspirin daily for at least 10 years to reduce their risk for CRC, according to a set of recommendations from the US Preventive Services Task Force. Naproxen is a highly efficacious CRC chemopreventive agent in animal models. Continuous/chronic usage of both drugs is limited by GI toxicity and unwanted side effects. Thus, the rationale to establish intermittent dosing regimens of Naproxen and Aspirin may provide efficacy without GI toxicity. Male F344 rats were used to establish Naproxen and Aspirin pharmacodynamic efficacy and dose-response effects. Rat (36 animals/group) colon cancers were induced by two weekly doses of azoxymethane (AOM). At the adenoma stage, rats were fed diets containing Naproxen (200 and 400 ppm) or Aspirin (700, and 1,400 ppm) either continuously, 1 week on/1 week off, or 3 weeks on/3 weeks off, or Aspirin (2,800 ppm) 3 weeks on/3 weeks off. All rats were euthanized 48 weeks after AOM treatment and assessed for efficacy, dose-response effects, and biomarkers in tumor tissues. Dietary administration of Naproxen and Aspirin did not show any overt-toxicities. Administration of 200 and 400 ppm of Naproxen inhibited colon adenocarcinoma multiplicity by 54.5% and 70.5% (p&lt;0.0001) (continuous treatment); 53.3% and 68.4% (p&lt;0.0001) (1 week on/1 week off); and 22.5% (p&lt;0.03) and 61.5% (p&lt;0.0001) (3 weeks on/3 weeks off), respectively. Importantly, inhibition of invasive colon carcinoma was reduced by 53% (p&lt;0.0009) - &gt;88% (p&lt;0.0001) with different treatment regimens of Naproxen. With regard to colon adenocarcinoma multiplicity, Aspirin showed significant inhibitory effect with different treatment regimens with clear dose-response effects. Total adenocarcinomas (both invasive and non-invasive) multiplicities were suppressed by 41% (P&lt;0.003) - 72% (p&lt;0.0001). Particularly, Aspirin showed suppression of invasive colon adenocarcinomas by &gt;67% (p&lt;0.0001) - &gt;91% (p&lt;0.0001) with different treatment regimens. Based on the biomarkers of proliferation and apoptosis, both agents showed significant modulation of proliferative (PCNA, p21) and apoptotic markers (p53, Casp3) in colonic tumors. Transcriptomic data revealed that proinflammatory cytokines, particularly interleukins and metalloproteases, were significantly reduced in tumors of rats exposed to Aspirin and Naproxen. Overall, our results suggest that intermittent dosing with Naproxen or Aspirin demonstrated significant dose-response efficacy on the progression of adenomas to adenocarcinomas, particularly invasive carcinomas. {This work was supported by NCI-N01-CN-250026}

Citation Format: Altaf Mohammed, Naveena B. Janakiram, Venkateshwar Madka, Yuting Zhang, Anil Singh, Laura Biddick, Qian Li, Stan Lightfoot, Vernon E. Steele, Ronald Lubet, Mark S. Miller, Chen S. Suen, Shizuko Sei, Chinthalapally V. Rao. Intermittent dosing regimens of naproxen and aspirin inhibit azoxymethane-induced rat colon adenoma progression to adenocarcinoma and carcinoma invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4983.

Lack of chemopreventive effects of P2X7R inhibitors against pancreatic cancer

Pancreatic cancer (PC) is an almost uniformly lethal disease with inflammation playing an important role in its progression. Sustained stimulation of purinergic receptor P2X7 drives induction of NLRP inflammasome activation. To understand the role of P2X7 receptor and inflammasome, we performed transcriptomic analysis of p48^Cre/+-LSL-Kras^G12D/+ mice pancreatic tumors by next generation sequencing. Results showed that P2X7R's key inflammasome components, IL-1β and caspase-1 are highly expressed (p < 0.05) in pancreatic tumors. Hence, to target P2X7R, we tested effects of two P2X7R antagonists, A438079 and AZ10606120, on pancreatic intraepithelial neoplasms (PanINs) and their progression to PC in p48^Cre/+-LSL-Kras^G12D/+ mice. Following dose optimization studies, for chemoprevention efficacy, six-week-old p48^Cre/+-LSL-Kras^G12D/+ mice (24–36/group) were fed modified AIN-76A diets containing 0, 50 or 100 ppm A438079 and AZ10606120 for 38 weeks. Pancreata were collected, weighed, and evaluated for PanINs and PDAC. Control diet-fed male mice showed 50% PDAC incidence. Dietary A438079 and AZ10606120 showed 60% PDAC incidence. A marginal increase of PanIN 3 (carcinoma in-situ) was observed in drug-treated mice. Importantly, the carcinoma spread in untreated mice was 24% compared to 43–53% in treatment groups. Reduced survival rates were observed in mice exposed to P2X7R inhibitors. Both drugs showed a decrease in caspase-3, caspase-1, p21 and Cdc25c. Dietary A438079 showed modest inhibition of P2X7R, NLRP3, and IL-33, whereas AZ10606120 had no effects. In summary, targeting the P2X7R pathway by A438079 and AZ10606120 failed to show chemopreventive effects against PC and slightly enhanced PanIN progression to PDAC. Hence, caution is needed while treating high-risk individuals with P2X7R inhibitors.

Abstract 5260: NGS Transcriptome analysis of colon adenocarcinomas treated with individual and combination of aspirin and omeprazole

Colorectal cancer (CRC) is the third most common type of cancer in men and women in US. Anti-inflammatory agents have proven to be most effective in CRC prevention, but are associated with gastrointestinal toxicities. Hence, to reduce the acidic environment and enhance the chemopreventive efficacy of anti-inflammatory agent aspirin, a combination of aspirin with acidity neutralizer omeprazole was used in AOM-induced F344 Rat model of CRC. Rat (36/group) colon cancers were induced by AOM (15mg/Kg body weight) s.c., once a week for two weeks. At adenoma stage (13 wks of age), rats were fed diets containing aspirin (700 or 1400ppm), omeprazole (0, 250 or 500 ppm), or aspirin + omeprazole (700 ppm + 250 ppm; 1,400 ppm + 500 ppm). To identify a molecular predictor of the benefit of aspirin plus omeprazole we performed next-generation sequencing of colon adenocarcinomas (AdCa) treated with aspirin (1400 ppm), omeprazole (500 ppm), aspirin plus omeprazole (1400 plus 500 ppm),conducted whole-transcriptome analysis and correlated the molecular portrait with chemoprevention benefit. Aspirin plus omeprazole enhanced colon AdCa incidence inhibitory effects by 55% (p&lt;0.0001) and multiplicity by ~87% (p&lt;0.0001) respectively in F344 rats. Transcriptome profiling revealed 1525 hits with a 1.5-fold expression difference threshold in aspirin-treated colon AdCa (722 upregulated genes, 803 downregulated genes, P &lt; 0.05), 1507 hits with a 1.5-fold expression difference threshold in omeprazole-treated colon AdCa (711 upregulated genes, 796 downregulated genes, P &lt; 0.05) and 1074 hits with a 1.5-fold expression difference threshold in aspirin plus omeprazole-treated colon AdCa (662 upregulated genes, 412 downregulated genes, P &lt; 0.05) compared to untreated colon AdCa. Multiple comparisons using Anova with samples from all groups revealed 691 hits with a 1.5-fold expression difference threshold with Benjamini Hochberg correction. Pathway analyses of these altered 691 genes indicated that the aspirin plus omeprazole treated colon AdCa upregulated cellular pathways (z score 2.26), Metabolism process (6.01) and cellular metabolic process (7.73), and downregulated signaling genes (- 8.18), signal transduction (- 8.03), immune response (- 2.08) and inflammatory response (- 2.95). A significant upregulation of Killer cell lectin-like receptor subfamily K, member 1 (natural cytotoxicity receptor which eliminates tumor cells), and acid phosphatase 2, lysosomal, (autophagy of tumor cells) was seen in the combination treatment groups compared to individual and control group AdCa. A significant decrease in TGF-β receptor signaling pathway gene SNX4 and ATPases was observed in combination treatments. Hence, these results suggest aspirin plus omeprazole combination treatments were devoid of GI toxicity increasing chemopreventive efficacy in colon cancer. Supported by NCI-N01-CN-250026

Citation Format: Naveena B. Janakiram, Altaf Mohammed, Jagan M.R. Patlolla, Yuting Zhang, Laura Biddick, Venkateshwar Madka, Li Qian, Stan Lightfoot, Barbara Dunn, Ronald Lubet, Chen S. Suen, Vernon E. Steele, Chinthalapally V. Rao. NGS Transcriptome analysis of colon adenocarcinomas treated with individual and combination of aspirin and omeprazole [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5260. doi:10.1158/1538-7445.AM2017-5260

Simultaneous targeting of 5-LOX-COX and EGFR blocks progression of pancreatic ductal adenocarcinoma

Cyclooxygenase-2 (COX-2), 5-Lipoxygenase (5-LOX), and epidermal growth factor receptor (EGRF) are over-expressed in human pancreatic ductal adenocarcinoma (PDAC). Using next-generation sequencing (NGS) analysis, we show significant increase in COX-2, 5-LOX, and EGFR expression during PDAC progression. Targeting complementary pathways will achieve better treatment efficacy than a single agent high-dose strategy that could increase risk of side effects and tumor resistance. To target COX-2, 5-LOX, and EGFR simultaneously, we tested effects of licofelone (dual 5-LOX-COX inhibitor), and gefitinib (EGFR inhibitor), individually and in combination, on pancreatic intraepithelial neoplasms (PanINs) and their progression to PDAC using genetically engineered mice. Individually, licofelone (L) and gefitinib (G) significantly inhibited incidence of PDAC in male (72% L, 90% G, p < 0.0001) and female (90% L, 85% G, p < 0.0001) mice. The combination drug treatment produced complete inhibition of PDAC in both genders. Pancreata of mice receiving combination treatment showed significantly fewer Dclk1-positive cancer stem-like cells, inhibition of COX-2, 5-LOX, PCNA, EGFR and β-catenin expression (p < 0.05–0.0002), increased p21 expression. Significant changes in tumor immune responses and desmoplastic reaction was observed by NGS analysis in combination treatment (p < 0.05). In summary, early simultaneous targeting of 5-LOX-COX- and EGFR pathways may provide additive inhibitory effects leading to complete suppression of PDAC.

Abstract 5255: Lack of chemopreventive effects of dietary P2×7R inhibitors against pancreatic cancer in p48Cre/+-LSL-KrasG12D/+ mice

Pancreatic cancer (PC) still remains a devastating disease that is almost uniformly lethal. Despite advances in the field of molecular genetics in human pancreatic cancers, targeted therapies has not yet translated to an improved overall survival for patients. Chronic inflammation is hallmark of many cancers, including PC. P2×7R is the most potent of the membrane receptors responsible for inflammasome activation and release of inflammatory cytokines. Sustained stimulation of P2×7R drives induction of NLRP inflammasome activation. To understand the role of P2×7 receptor and inflammasome in pancreatic tumor progression, we carried transcriptomic analysis of LSL-Kras pancreatic tumors by next generation sequencing. Results showed that the P2×7 receptor (∼20-fold); key inflammasome components, IL-1β (∼45-fold), caspase-1 (15-fold), IL-18 (∼35-fold), IL-33 (∼93 folds), TNF-α (∼13-fold) and COX-2 (∼41-fold) are highly expressed (p&lt;0.05). Analysis of human PC cell lines, human and mouse PC tissues by western immunoblotting, real time (RT)-polymerase chain reaction (PCR), immunohistochemistry and/or immunofluorescence suggest that the P2×7R is a critical contributor to the progression of pancreatic tumor growth. Hence, to target P2×7R, we tested the effects of two P2×7R antagonists A438079 and AZ10606120 at two doses (50 and 100 ppm) on pancreatic intraepithelial neoplasms (PanINs) and their progression to PDAC in p48Cre/+-LSL-KrasG12D/+ mice. Six-week old KrasG12D/+ (24-36/group) mice were fed (AIN-76A) diets containing 0, 50 or 100 ppm of A438079 and AZ10606120 for 38 weeks. Pancreata were collected, weighed, and evaluated histopathologically for PanINs and PDAC. To understand molecular mechanisms, we analyzed levels of proliferation, inflammatory and cell cycle makers; PCNA, p21, P2×7R, NLRP, COX-2, IL-33, caspase-3, caspase-1, Cdc25c and p53 expressions by IHC, IHF, Western blotting, and/or RT-PCR methods. Results suggest that control diet fed mice showed 50% incidence of PDAC in male mice. Dietary A4338079 and AZ10606120 showed up to 60% incidence of PDAC. CT-PET imaging analysis showed enhanced tumor growth in treatment groups. Importantly, the carcinoma spread in untreated mice was 24% as compared to 43-53% in treatment groups. Also, marginal increase of PanIN 3 (carcinoma in-situ) was observed in drug treated mice. Both drugs showed a decrease in caspase-3, caspase-1, p21 and Cdc25c. Dietary A438079 showed modest inhibition of PCNA, P2×7R, NLRP, and IL-33 whereas AZ10606120 had no effects. In summary, targeting the P2×7R pathway by A438079 and AZ10606120 failed to show significant chemopreventive effects in suppression of PC and hence caution is needed while treating high risk individuals for PC with P2×7R inhibitors. Also, it is not clear whether dietary route of administration might be reason for lack of efficacy. {Supported by NCI-CN-N01- 25008-78}.

Citation Format: Altaf Mohammed, Naveena B. Janakiram, Venkateshwar Madka, Gopal Pathuri, Qian Li, Rebekah Ritchie, Laura Biddick, Hannah Kutsche, Yuting Zhang, Anil Singh, Hariprasad Gali, Stan Lightfoot, Vernon E. Steele, Chen S. Suen, Chinthalapally V. Rao. Lack of chemopreventive effects of dietary P2×7R inhibitors against pancreatic cancer in p48Cre/+-LSL-KrasG12D/+ mice. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5255.

Abstract 2621: Disruption of mucin synthesis by targeting GCNT3 inhibits pancreatic cancer progression

Pancreatic cancer (PC) is a lethal disease, and its management is an ongoing challenge. PC is the fourth leading cause of deaths due to cancer in the United States. It is a highly aggressive cancer that is usually diagnosed at an advanced stage, and has the worst prognosis of any malignancy, with a five year survival of &lt;7% due to high chemoresistance. This chemoresistance is due in part to altered expressions of mucins, which form a mesh that makes target sites inaccessible to drugs. Clinical and preclinical studies have shown aberrant expression of mucins during PC development. The mucins may prevent drugs from accessing their sites of action. Although several mucins that lead to chemoresistance have been targeted, to date, no mucin synthesizing genes have been identified as targets. Using human pancreatic cancer patient survival data (90 cases of tumor and matched normal adjacent tissue), next-generation sequencing (NGS) of genetically engineered Kras mouse pancreatic tumors (N = 6/group), human PC cells, we identified novel core mucin synthesizing gene target GCNT3 (core 2 beta 1,6 N-acetylglucosaminyltransferase). NGS revealed that GCNT3 upregulation (103-fold; p&lt;0.0001) was correlated with increased mucins Muc4 (50-fold; p&lt;0.04), Muc5ac (87-fold; p&lt;0.01), Muc6 (67-fold; p&lt;0.008), Muc1 (5-fold; p&lt;0.009), Muc16 (5-fold; p&lt;0.0003) and Muc20 (17-fold; p&lt;0.007)]. Aberrant GCNT3 expression was associated with increased mucin production and aggressive tumorigenesis and reduced patient survival. Patients with low expression of GCNT3 had a longer survival time than patients with high expression of GCNT3 (median survival: 17.5 vs. 10.5 months, p = 0.036). Further, using in-silico approaches of small molecular docking simulations, we identified talniflumate as a novel inhibitor that specifically binds to GCNT3. Our blind docking simulations reveal that talniflumate binds to GNTC3 with a docking affinity of -8.3 kcal/mol and deeper in the pocket of GCNT3. The docking predictions suggest three notable hydrogen bonds between talniflumate and GCNT3: Arg192 (3.0 Angstroms), Try288 (3.5 Angstroms), and Ala287 (2.9 Angstroms). Pancreata from 6-week-old Kras mice treated with talniflumate for 1 week showed a significant decrease in GCNT3 and mucin expression in PanIN lesions. mRNA expression of GCNT3 was also observed to be lower in pancreatic tissues from talniflumate-treated mice. CRISPR knock-out of GCNT3 in PC cells reduced proliferation and spheroid formation. Further, talniflumate alone and in combination with low-dose gefitinib reduced GCNT3 leading to disruption of mucins in vivo and in vitro. Hence, mucin disruption might enhance targeted therapy. These findings suggest a prominent role for Kras activation and aberrant mucin synthesis leading to PC pathogenesis, and warrant consideration of GCNT3 and EGFR inhibitors as a combination treatment for PC. (Grant Support: COMAA, Kerley-Cade Endowed Fund).

Citation Format: Altaf Mohammed, Naveena B. Janakiram, Venkateshwar Madka, Gaurav Kumar, Scott Edgar, Gopal Pathuri, Taylor Bryant, Hannah Kutsche, Yuting Zhang, Laura Biddick, Hariprasad Gali, Yan Daniel Zhao, Stan Lightfoot, Chinthalapally V. Rao. Disruption of mucin synthesis by targeting GCNT3 inhibits pancreatic cancer progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2621.

Abstract 2625: Simultaneous targeting of ODC and 5-LOX/COX block the tobacco carcinogen-induced lung adenoma progression to adenocarcinoma in A/J mice

Increased polyamine synthesis and inflammation have long been associated with intraepithelial neoplasia and their progression to malignant tumor growth, including lung cancer. Targeting multiple pathways simultaneously with low-dose combinations may be an effective approach to modulate different pathways and their downstream signaling, which may result in an increased efficacy and reduced side effects than a single-agent high dose strategy. The aim of the present study was to investigate the effects of DFMO (ODC inhibitor) and licofelone, a dual 5-LOX-COX inhibitor, individually and in combination, on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone NNK-induced lung adenoma and progression to adenocarcinoma in female A/J mice. At 6 weeks of age, mice (25 /group) were fed AIN-76A-modified diet, and one week later, lung tumors were induced with a single intraperitoneal (i.p.) injection of 10 μmol NNK/mouse. Three weeks after the NNK treatment, groups of mice were fed with either control or experimental diets containing DFMO (1500 or 3000 ppm) or Licofelone (200 or 400 ppm) or combination of low doses of DFMO and Licofelone. Mice were killed after 17 or 34 weeks of drug exposure and tumors were evaluated via histopathology and lung tumors were assayed for modification of various biomarkers of proliferation and apoptosis. Results suggest that both DFMO and licofelone showed dose-dependent inhibition of NNK-induced lung adenoma progression to adenocarcinoma. At high dose DFMO and Licofelone showed 46% and 55% of adenocarcinoma inhibition. Importantly, low dose combination of DFMO and licofelone showed more pronounced effects at both 17 or 34 weeks in inhibiting the total adenocarcinomas (adenoma and adenocarcinoma progression) by &gt;65% and somewhat in a synergistic manner as compared to individual low doses of DFMO and licofelone. Combination-treated lung tumors exhibited

modulation of ODC pathway key components (Arg1, Oat, Oaz, SRM, SMS, and SAT) along with decreased proliferation (PCNA, cyclin D1 and Cyclin A) and increased expression of p53, p21 and p27 compared to tumors from mice fed with control diet. These data suggest that targeting ODC plus 5-LOX/COX decreases the progression of adenoma to adenocarcinoma. Furthermore, adenoma progression delay by combination of DFMO and Licofelone is associated with decreased tumor invasive markers such as MMTPs and EMT markers. In conclusion, targeting two or more pathways is an effective chemopreventive approach for high-risk lung cancer individual's particularly former tobacco smokers with lung hyperplasia and adenomas.

(Supported by Kerley-Cade Chair Endowment and NCI-N01-CN-53300)

Citation Format: Gaurav Kumar, Jagan Mohan R. Patolla, Venkateshwar Madka, Altaf Mohammed, Li Qian, Yuting Zhang, Laura Biddick, Anil Singh, Allison Gillaspy, Stanley Lightfoot, Levy Kopelovich, Vernon E. Steele, Chinthalapally V. Rao. Simultaneous targeting of ODC and 5-LOX/COX block the tobacco carcinogen-induced lung adenoma progression to adenocarcinoma in A/J mice. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2625.

Systemic Chromosome Instability Resulted in Colonic Transcriptomic Changes in Metabolic, Proliferation, and Stem Cell Regulators in Sgo1-/+ Mice

Colon cancer is the second most lethal cancer and is predicted to claim 49,700 lives in the United States this year. Chromosome instability (CIN) is observed in 80% to 90% of colon cancers and is thought to contribute to colon cancer progression and recurrence. To investigate the impact of CIN on colon cancer development, we developed shugoshin-1 (Sgo1) haploinsufficient (-/+) mice, an animal model focusing on mitotic error-induced CIN. In this study, we analyzed signature changes in the colonic transcriptome of Sgo1(-/+) mice to examine the molecular events underlying the altered carcinogenesis profiles in Sgo1(-/+) mice. We performed next-generation sequencing of normal-looking colonic mucosal tissue from mice treated with the carcinogen azoxymethane after 24 weeks. Transcriptome profiling revealed 349 hits with a 2-fold expression difference threshold (217 upregulated genes, 132 downregulated genes, P < 0.05). Pathway analyses indicated that the Sgo1-CIN tissues upregulated pathways known to be activated in colon cancer, including lipid metabolism (z score 4.47), Notch signaling (4.47), insulin signaling (3.81), and PPAR pathways (3.75), and downregulated pathways involved in immune responses including allograft rejection (6.69) and graft-versus-host disease (6.54). Notably, stem cell markers were also misregulated. Collectively, our findings demonstrate that systemic CIN results in transcriptomic changes in metabolism, proliferation, cell fate, and immune responses in the colon, which may foster a microenvironment amenable to cancer development. Therefore, therapeutic approaches focusing on these identified pathways may be valuable for colon cancer prevention and treatment.

Simultaneous targeting of 5-LOX-COX and ODC block NNK-induced lung adenoma progression to adenocarcinoma in A/J mice

Lung cancer is the leading cause of cancer deaths worldwide. Targeting complementary pathways will achieve better treatment efficacy than a single agent high-dose strategy that could increase risk of side effects and tumor resistance. To target COX-2, 5-LOX, and ODC simultaneously, we tested the effects of a dual 5-LOX-COX inhibitor, licofelone, and an ODC inhibitor, DFMO, alone and in combination, on NNK-induced lung tumors in female A/J mice. Seven-week-old mice were treated with NNK (10 μmol/mouse, single dose, i.p.) and randomized to different treatment groups. Three weeks after injection, mice were fed control or experimental diets (DFMO 1500/3000 ppm, licofelone 200/400 ppm, or a low-dose combination of 1500 ppm DFMO and 200 ppm licofelone) for 17 or 34 weeks. Both agents significantly inhibited tumor formation in a dose-dependent manner. As anticipated more adenomas and adenocarcinomas were observed at 17 and 34 weeks, respectively. Importantly, low dose combination of DFMO and licofelone showed more pronounced effects at 17 or 34 weeks in inhibiting the total tumor formation (~60%, p < 0.0001) and adenocarcinoma (~65%, p < 0.0001) compared to individual high dose of DFMO (~44% and 46%, p < 0.0001) and licofelone (~48% and 55%, p < 0.0001). DFMO and combination-treated mice lung tumors exhibited modulated ODC pathway components (Oat, Oaz, SRM, SMS, and SAT, p < 0.05) along with decreased proliferation (PCNA, Cyclin D1 and Cyclin A) and increased expression of p53, p21 and p27 compared to mice fed control diet. Both DFMO and licofelone significantly inhibited tumor inflammatory markers. Our findings suggest that a low-dose combined treatment targeting inflammation and polyamine synthesis may provide effective chemoprevention.

Small-Molecule Inhibition of GCNT3 Disrupts Mucin Biosynthesis and Malignant Cellular Behaviors in Pancreatic Cancer

Pancreatic cancer is an aggressive neoplasm with almost uniform lethality and a 5-year survival rate of 7%. Several overexpressed mucins that impede drug delivery to pancreatic tumors have been therapeutically targeted, but enzymes involved in mucin biosynthesis have yet to be preclinically evaluated as potential targets. We used survival data from human patients with pancreatic cancer, next-generation sequencing of genetically engineered Kras-driven mouse pancreatic tumors and human pancreatic cancer cells to identify the novel core mucin-synthesizing enzyme GCNT3 (core 2 β-1,6 N-acetylglucosaminyltransferase). In mouse pancreatic cancer tumors, GCNT3 upregulation (103-fold; P < 0.0001) was correlated with increased expression of mucins (5 to 87-fold; P < 0.04-0.0003). Aberrant GCNT3 expression was also associated with increased mucin production, aggressive tumorigenesis, and reduced patient survival, and CRISPR-mediated knockout of GCNT3 in pancreatic cancer cells reduced proliferation and spheroid formation. Using in silico small molecular docking simulation approaches, we identified talniflumate as a novel inhibitor that selectively binds to GCNT3. In particular, docking predictions suggested that three notable hydrogen bonds between talniflumate and GCNT3 contribute to a docking affinity of -8.3 kcal/mol. Furthermore, talniflumate alone and in combination with low-dose gefitinib reduced GCNT3 expression, leading to the disrupted production of mucins in vivo and in vitro Collectively, our findings suggest that targeting mucin biosynthesis through GCNT3 may improve drug responsiveness, warranting further development and investigation in preclinical models of pancreatic tumorigenesis. Cancer Res; 76(7); 1965-74. ©2016 AACR.

Targeting mTOR and p53 Signaling Inhibits Muscle Invasive Bladder Cancer In Vivo

Urothelial tumors, accompanied by mutations of the tumor suppressor protein TP53 and dysregulation of mTOR signaling, are frequently associated with aggressive growth and invasiveness. We investigated whether targeting these two pathways would inhibit urothelial tumor growth and progression. Six-week-old transgenic UPII-SV40T male mice (n = 15/group) were fed control diet (AIN-76A) or experimental diets containing mTOR inhibitor (rapamycin, 8 or 16 ppm), p53 stabilizing agent [CP31398 (CP), 150 ppm], or a combination. Mice were euthanized at 40 weeks of age. Urinary bladders were collected and evaluated to determine tumor weight and histopathology. Each agent alone, and in combination, significantly inhibited tumor growth. Treatment with rapamycin alone decreased tumor weight up to 67% (P < 0.0001). Similarly, CP showed approximately 77% (P < 0.0001) suppression of tumor weight. The combination of low-dose rapamycin and CP led to approximately 83% (P < 0.0001) inhibition of tumor weight. There was no significant difference in tumor weights between rapamycin and CP treatments (P > 0.05). However, there was a significant difference between 8 ppm rapamycin and the combination treatment. Tumor invasion was also significantly inhibited in 53% (P < 0.005) and 66% (P < 0.0005) mice after 8 ppm and 16 ppm rapamycin, respectively. However, tumor invasion was suppressed in 73% (P < 0.0001) mice when CP was combined with 8 ppm rapamycin. These results suggest that targeting two or more pathways achieve better treatment efficacy than a single-agent high-dose strategy that could increase the risk of side effects. A combination of CP and rapamycin may be a promising method of inhibiting muscle-invasive urothelial transitional cell carcinoma.

Adoptive transfer of regulatory T cells promotes intestinal tumorigenesis and is associated with decreased NK cells and IL-22 binding protein

High number of regulatory T cells (Tregs), both circulating and at the tumor site, often indicates a poor prognosis in CRC patient's possibly impairing natural killer (NK) cell function. To determine the role of Tregs in CRC development and their effects on NK cells, we created novel transgenic Rag-Apc mice that lack T cells and develop spontaneous intestinal tumors, and we adoptively transferred Tregs or transiently depleted NK cells during initial stages of tumorigenesis. In 6-weeks old Rag-Apc mice containing microscopic intestinal tumors adoptive transfer of Tregs or transient NK cell depletion dramatically associated with an increase in intestinal tumor multiplicity and tumor size, with significantly decreased survival rates. Importantly, Treg transfer increased small intestinal polyp formation up to 65% (P < 0.0005) and increased colon tumors multiplicities by 84% (P < 0.0001) with a significant decrease in NK cells as compared to control mice. Similarly, in NK depleted mice, colon tumor multiplicities increased up to 40% and small intestinal polyp formation up to 60% (P < 0.0001). Treg transfer or NK cell transient depletion markedly increased interleukin (IL)-22 systemically and the inflammatory signaling molecules P2X7R, and STAT3 in the tumors; and impaired production of the tumor suppressor interferon (IFN)-γ systemically. Notably, IL-22 binding protein (IL-22 BP) was associated with NKs and a significant decrease was seen at the tumor site in mice adoptively transferred with Tregs or depleted of NK cells. Our results suggest that adoptive transfer of Tregs aggressively promote intestinal tumorigenesis by decreasing NK cell number and activity by modulating IL-22 BP.

Abstract 1905: Galectin-3 and -4 as signature markers of lung, colon, pancreatic and bladder tumor progression and chemopreventive interventions

Galectins, a family of glycan-binding proteins, interact with cell-surface glycoconjugates and influence tumor progression by triggering a cascade of transmembrane signaling events which influence pathogenesis of cancer or tumor outcome. Despite considerable progress in identifying the involvement of individual galectins in tumor biology, an integrated portrait of the galectin network in different organ-site tumors or its microenvironments is not fully established. To understand the role of each galectin in lung, colon, pancreas and urinary bladder tumors and their relevance as markers of tumor progression; chemoprevention intervention trials was evaluated. Lung adenoma and adenocarcinomas were induced by tobacco specific carcinogen, NNK and colon adenomas and adenocarcinomas by azoxymethane (AOM). Whereas, pancreatic ductal tumors were induced by KrasG12D activation in p48Cre.KrasG12D mice and bladder tumors were induced by SV40 activation in UPII-SV40T mice. Expression profiling of galectins was obtained by whole genome-transcriptome analysis with SOLiD methodology from RNAs of tumors and normally appearing tissues from each organ-site. Further profiling and characterization of each galectin (Gal) was carried by RT-PCR, western blotting, and immunohistochemcial analysis. Data from transcriptome suggest that Gal-1, Gal-3, Gal-4, and Gal-12 are significantly associated with tumor progression. Particularly, Gal-1, Gal-3, and Gal-4 expressions were positively correlated with tumor progression in all the above cancers compared to their respective normal tissues and early lesions. Gal-12 was significantly increased in pancreatic and bladder tumor tissues but not in lung and colonic tumors. To understand prognostic value of galectins for chemoprevention interventions, we tested well-established and highly efficacious agents, difluoromethyl ornithine (DFMO), an inhibitor of ODC), and Licofelone, a dual COX-LOX inhibitor in above organ site cancers. DFMO (up to 2,000 ppm) and Licofelone (up to 500 ppm) was administered in the diet to mice after initiation of preneoplastic lesions or adenomas and continued until malignant tumor formations. As anticipated, both agents significantly inhibited malignant tumor formation. Importantly, intervention of tumor growth with mice fed with chemopreventive agents (DFMO and licofelone) showed a significant decrease in expression of Gal-3 and Gal-4 in tumor tissues and correlated with progression of tumor growth inhibition. Overall, these data provide impetus for further studies to delineate the role of Gal-3 and Gal-4 in various cancers and their usefulness as prognostic markers of chemoprevention interventions. (Supported by Kerley-Cade Chair Endowment and NCI-N01-CN-53300)

Citation Format: Gaurav Kumar, Venkateshwar Madka, Altaf Mohammed, Jagan M. r. Patolla, Naveena B. Janakiram, Qian Li, Yuting Zhang, Laura Biddick, Allison Gillaspy, Stanley Lightfoot, Chinthalapally V. Rao. Galectin-3 and -4 as signature markers of lung, colon, pancreatic and bladder tumor progression and chemopreventive interventions. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1905. doi:10.1158/1538-7445.AM2015-1905

Abstract 2881: Systemic Chromosome Instability (CIN) resulted in transcriptomic changes in metabolic and proliferation regulators in colonic mucosal tissue of Sgo1-/+ mice

(a) Colon cancer is the second most lethal cancer and is predicted to claim 50,310 lives in 2014. Chromosome Instability (CIN) is observed in 80-90% of colon cancers and is thought to contribute to colon cancer progression and recurrence. We developed animal models focusing on mitotic error-induced CIN, Shugoshin-1 (Sgo1) haploinsufficient (-/+) mice, to investigate the impact of CIN on colon cancer development. Sgo1-/+ mice showed altered profiles in colonic lesions and cancer development. In this study, we analyzed signature changes in the colonic transcriptome of Sgo1-/+ mice to investigate underlying molecular events in the altered carcinogenesis profiles.

(b) We treated control and Sgo1-/+ mice with colonic carcinogen azoxymethane (AOM), and tracked colon cancer development 12, 24, and 36 weeks after AOM treatments. We performed Next Generation Sequencing (NGS)-based transcriptome analysis at 24 weeks.

(c) There were 349 hits with 2-fold expression difference threshold, P&lt;0.05 (217 upregulated genes, 132 downregulated genes). In normal-looking colonic mucosal tissue from Sgo1 mice, we observed notable transcriptomic changes in the lipid metabolism, Notch signaling, insulin signaling, and peroxisome proliferator-activated receptor (PPAR) pathways. The profile had partial overlap with the colon tumor transcriptome, consistent with high prevalence of CIN in colon cancer. By applying secondary selection criteria, we also identified cell surface markers that may be used to selectively target colonic CIN cells with antibody-based or vaccine approaches.

(d) Systemic Chromosome Instability resulted in transcriptomic changes in metabolic and proliferation regulators in the colon. We propose that the CIN effect may be countered through manipulation of these pathways.

Citation Format: Chinthalapally V. Rao, Saira Sanghera, Yuting Zhang, Laura Biddick, Arun Reddy, Stan Lightfoot, Altaf Mohammed, Wei Dai, Hiroshi Y. Yamada. Systemic Chromosome Instability (CIN) resulted in transcriptomic changes in metabolic and proliferation regulators in colonic mucosal tissue of Sgo1-/+ mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2881. doi:10.1158/1538-7445.AM2015-2881

Abstract 2820: Omeprazole alone, or in combination with Aspirin inhibits azoxymethane-induced colon adenoma progression to adenocarcinoma and carcinoma invasion in F344 rat model

Colorectal Cancer (CRC) is a major public health issue world-wide with an estimated over 600,000 deaths annually. Aspirin and Omeprazole are most commonly used medications. Aspirin has been proven as CRC chemopreventive agent, but its usage is limited by GI toxicity. The rationale to establish the chemopreventive role of Omeprazole has been based on i) acidic tumor environment due to the Warburg-effect, and ii) it may protect from the GI toxicity induced by aspirin. Male F344 rats were used to establish omeprazole and aspirin optimal doses, efficacy, dose-response effects of combinations. Rat (36-42 animals per group) colon cancers were induced by two weekly dose of AOM. At adenoma stage, rats were fed diets containing Omeprazole (0, 250 or 500 ppm), or aspirin + omeprazole (700 ppm + 250 ppm; 1,400 ppm + 500 ppm; 2,800 ppm + 250 ppm, respectively) and a combination dose fed every three weeks on and off. All rats were euthanized 48 weeks after AOM treatment and assessed for efficacy, dose-response effects and various biomarkers in colonic tissues. Dietary administration of test agents alone or combinations did not show any overt-toxicities. Administration of 250 and 500 ppm omeprazole inhibited colon adenocarcinoma incidence by 15.7% and 32% (p&lt;0.01) and multiplicity by 49% (p&lt;0.0001) and 65% (p&lt;0.0001), respectively; importantly, colon invasive carcinoma incidence was reduced by 59% and 90% (p&lt;0.0001) and multiplicity by 74% and 93% (p&lt;0.0001), respectively. However, we observed a modest decrease in total colonic tumors with a significant increase in adenomas. Continuous administration of above combinations showed inhibition of adenocarcinoma incidences by 41% (p&lt;0.001), 55% (p&lt;0.0001) and 74% (p&lt;0.0001) and multiplicities by 74%, 76% and 87% (p&lt;0.0001). Interestingly, intermittent dosing of combinations did not diminish inhibition of CRC incidence or multiplicity. Furthermore, omeprazole alone or combining with aspirin showed &gt;90% inhibition of invasive adenocarcinomas. In tumors of rats fed omeprazole alone or in combination with aspirin, there was a significant decrease in markers of proliferation (PCNA and β-catenin) and increase in apoptosis (p53, p21, Annexin V) when compared with CRC of rats fed control diet. Surprisingly, we observed a dramatic decrease in the expression levels of proton pump (K+-, H+- ATPase) markers in colonic tumors as compared to tumor adjacent mucosa. These results suggest that omeprazole tumor inhibitory mechanism may not be dependent on tumor proton pump inhibition. Overall, our results suggest that Omeprazole had significant dose-response efficacy effects on the adenoma progression to adenocarcinomas; particularly invasive carcinomas and combining with aspirin significantly enhanced adenocarcinoma inhibitory effects. {This work was supported by NCI-N01-CN-250026}

Citation Format: Altaf Mohammed, Jagan M.R Patlolla, Yuting Zhang, Laura Biddick, Venkateshwar Madka, Qian Li, Stan Lightfoot, Ronald Lubet, Chen S. Suen, Vernon E. Steele, Chinthalapally V. Rao. Omeprazole alone, or in combination with Aspirin inhibits azoxymethane-induced colon adenoma progression to adenocarcinoma and carcinoma invasion in F344 rat model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2820. doi:10.1158/1538-7445.AM2015-2820

Antagonizing pathways leading to differential dynamics in colon carcinogenesis in Shugoshin1 (Sgo1)-haploinsufficient chromosome instability model

Colon cancer is the second most lethal cancer. It is predicted to claim 50,310 lives in 2014. Chromosome Instability (CIN) is observed in 80-90% of colon cancers, and is thought to contribute to colon cancer progression and recurrence. However, there are no animal models of CIN that have been validated for studies of colon cancer development or drug testing. In this study, we sought to validate a mitotic error-induced CIN model mouse, the Shugoshin1 (Sgo1) haploinsufficient mouse, as a colon cancer study model. Wild-type and Sgo1(-/+) mice were treated with the colonic carcinogen, azoxymethane (AOM). We tracked colon tumor development 12, 24, and 36 wk after treatment to assess progression of colon tumorigenesis. Initially, more precancerous lesions, Aberrant Crypt Foci (ACF), developed in Sgo1(-/+) mice. However, the ACF did not develop straightforwardly into larger tumors. At the 36-wk endpoint, the number of gross tumors in Sgo1(-/+) mice was no different from that in wild-type controls. However, Copy Number Variation (CNV) analysis indicated that fully developed colon tumor in Sgo1(-/+) mice carried 13.75 times more CNV. Immunohistological analyses indicated that Sgo1(-/+) mice differentially expressed IL-6, Bcl2, and p16(INK4A) . We propose that formation of ACF in Sgo1(-/+) mice is facilitated by the IL6-STAT3-SOCS3 oncogenic pathway and by the Bcl2-anti-apoptotic pathway, yet further development of the ACF to tumors is inhibited by the p16(INK4A) tumor suppressor pathway. Manipulating these pathways would be beneficial for inhibiting development of colon cancer with CIN.

Abstract 2969: Combinational Targeting of EGFR and ODC pathways by Gefitinib and DFMO lead to complete blockade of PanIN progression to pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is a devastating disease with almost uniform lethality despite aggressive treatment (5-year survival rate of &lt;6%). Developing novel strategies to prevent/delay/inhibit progression of PC is currently of intense interest. Epidermal growth factor receptor (EGFR) is over-expressed in ∼87% human pancreatic cancers and plays a pivotal role in tumor cell proliferation. An interaction between ornithine decarboxylase (ODC) overexpression and EGFR was suggested by the elevation of EGFR Tyr-K activity. Clinical and preclinical studies have clearly demonstrated chemopreventive potential of difloromethyl ornithine (DFMO), an ODC inhibitor. Higher doses of gefitinib (EGFR inhibitor) and DFMO has been associated with skin- and oto-toxicity respectively. Hence, to target EGFR and ODC simultaneously, we tested the effects of lower doses of gefitinib and DFMO individually and in combination on pancreatic intraepithelial neoplasms (PanINs) and their progression to pancreatic ductal adenocarcinoma (PDAC) in p48Cre/+-LSL-KrasG12D/+ transgenic mice.

Six-week old male and female KrasG12D/+ (24-34/group) mice were fed (AIN-76A) diets containing 0%, 0.01% gefitinib, 0.1% DFMO or combination of both for 38 weeks. Pancreata were collected, weighed, and evaluated histopathologically for PanINs and PDAC. To understand molecular mechanisms, we analyzed levels of proliferation, apoptosis and cell cycle makers; PCNA, p21, β-catenin, Cav-1, Bcl-XL, c-MYC, cyclin E and pERK expressions by IHC, IHF, Western blotting, and/or RT-PCR methods. Results suggest that control diet fed mice showed 80 and 65% incidence of PDAC in male and female mice, respectively. Dietary gefitinib and DFMO significantly inhibited incidence of PDAC in both male (90 & 87%, respectively, p&lt;0.0001) and female (84 & 75%, respectively, p&lt;0.0001) mice. Most importantly, the combination drug treatment showed complete (100%, p&lt;0.0001) inhibition of PDAC incidence in both genders of mice. Also, significant suppression of PanIN 3 (carcinoma in-situ) was observed in mice fed by gefitinib, DFMO and their combination. Importantly, ∼77% of the pancreas was free from lesions and carcinoma in the combination treatment compared to only 4 % in control and 39 and 23 % in gefitinib and DFMO fed mice respectively. The pancreas of mice fed combination diets showed a significant inhibition of PCNA, β-catenin, Cav-1, Bcl-XL, c-MYC, cyclin E and pERK expression levels (p&lt;0.05-0.001); and increased p21 when compared to the pancreatic cancer derived from control diet or individual drug fed mice. In summary, targeting the EGFR and ODC pathways simultaneously may provide synergistic and/or additive chemopreventive effects in suppression of PC and has significant potential for undertaking clinical trials of pancreatic cancer chemoprevention. {Supported by NCI-CN-N01-53300}.

Citation Format: Altaf Mohammed, Naveena B. Janakiram, Rebekah L. Ritchie, Laura Biddick, Misty Brewer, Stan Lightfoot, Vernon E. Steele, Chinthalapally V. Rao. Combinational Targeting of EGFR and ODC pathways by Gefitinib and DFMO lead to complete blockade of PanIN progression to pancreatic ductal adenocarcinoma. [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 2969. doi:10.1158/1538-7445.AM2014-2969

Abstract 93: Antagonizing pathways leading to differential dynamics in colonic carcinogenesis in azoxymethane (AOM)-treated Sgo1 (Shugoshin1)-haploinsufficient chromosome instability (CIN) model mice

(a) Colon cancer is the second most lethal cancer and is predicted to claim 50,830 lives in 2013. Chromosome Instability (CIN) is observed in 80-90% of colon cancers and is thought to contribute to colon cancer progression and recurrence. For drug development, animal models that reflect cancer-specific etiology is necessary. However, animal models focusing on CIN have not been validated for colon cancer development and for drug testing. In this study, we set out to validate a mitotic error-induced CIN model mice, Shugoshin1 (Sgo1) haploinsufficient mice, as a colon cancer study model.

(b) We treated control and Sgo1-/+ mice with colonic carcinogen Azoxymethane (AOM), and tracked colon cancer development over 12, 24 and 36 weeks after AOM treatments. The three endpoints provided information regarding the time course for colon cancer development.

(c) Although we predicted an increase in colon tumors in Sgo1-/+ mice at a later (24 or 36 weeks) endpoint, precancerous lesions the Aberrant Crypt Foci (ACF) did not develop to larger tumors straightforwardly. Unexpectedly, the numbers of gross colon tumors showed no difference (P&gt;0.05). Immunohistological analyses indicated IL6, Bcl2 and p16INK4A were differentially expressed in Sgo1-/+ mice.

(d) We propose that formation of ACF in Sgo1-/+ mice are facilitated by IL6-STAT3-SOCS3 oncogenic pathway and Bcl2-anti-apoptotic pathway, yet further development of the ACF to tumors are inhibited by p16INK4A tumor suppressor pathway. Manipulating these pathways would be beneficial for inhibiting development of colon cancer with CIN. The CIN mice may be useful for investigating carcinogenesis in earlier stage and tumor regression in later stage.

Citation Format: Chinthalapally V. Rao, Saira Sanghera, Yuting Zhang, Laura Biddick, Stan Lightfoot, Wei Dai, Hiroshi Y. Yamada. Antagonizing pathways leading to differential dynamics in colonic carcinogenesis in azoxymethane (AOM)-treated Sgo1 (Shugoshin1)-haploinsufficient chromosome instability (CIN) model mice. [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 93. doi:10.1158/1538-7445.AM2014-93

Abstract 2135: Chemoprevention of tobacco carcinogen-induced lung cancer by DFMO and Licofelone administered individually or in combination in female A/J mice

Lung cancer is the leading cause of cancer death among both men and women in the US. Inflammatory eicosanoids and leukotrienes derived from cyclooxygenase (COX)-2 and 5-lipoxygenase (LOX) pathway positively influences lung tumor growth. Overexpression of ornithine decarboxylase (ODC) enzyme activity and polyamines has been associated with proliferation and progression of lung cancer. Thus, targeting both tumor inflammatory molecules and polyamines synthesis may provide additive/synergistic antitumor effects. To overcome clinical toxicity of high dose difluoromethyl ornithine (DFMO), an inhibitor of ODC; and to target both COX-2/5LOX, we tested low dose DFMO combined with Licofelone, a novel dual inhibitor COX-2/5-LOX, in lung cancer model. At 7 weeks of age, mice (25 mice/group) were treated with 10 μmol 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) /mouse to induce the lung tumors. Three weeks after the NNK treatment, mice were fed either control or experimental diets containing 200, 400 ppm licofelone or 1500 and 3000 ppm DFMO or low-dose combinations of both agents. Mice were killed at 20 weeks (10 mice/group) and/or 36 weeks (15 mice/group) after NNK-treatment for lung tumor evaluation. Administration of 200 and 400 ppm licofelone significantly suppressed lung tumor (adenoma + adenocarcinoma) formation by &gt;32 to 35% (p43 to 47% (p25 to 30% (p44% (p53% (p60% (p&lt;0.0001) respectively at 17 and 34 weeks exposure. These results suggest that low-dose combinations of licofelone and DFMO inhibit the NNK-induced lung adenocarcinoma formation synergistic/additive manner. Immunohistochemistry analysis revealed that lung tumors from mice exposed to licofelone plus DFMO showed significantly reduced proliferating cell nuclear antigen (PCNA)-positive index, increased accumulation of TUNEL positive cells as compared to lung tumors from NNK-treated mice fed with control diet. These results demonstrate the targeting lung tumor COX-LOX with ODC may provide better efficacy when compared to individual targets on tobacco carcinogen-induced lung adenocarcinomas formation. {Supported by NIH, NCI grants NO1-CN-53300 and Kerley-Cade Chair}.

Citation Format: Jagan Mohan Reddy Patlolla, Levy Kopelovich, Li Qian, Laura Biddick, Yuting Zhang, Michael K. Sadeghi, Dhimant Desai, Shantu Amin, Stan Lightfoot, Vernon E. Steele, Chinthalapally V. Rao. Chemoprevention of tobacco carcinogen-induced lung cancer by DFMO and Licofelone administered individually or in combination in female A/J mice. [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 2135. doi:10.1158/1538-7445.AM2014-2135

Abstract 1244: Licofelone, a dual COX-LOX inhibitor prevents transitional cell carcinoma of urinary bladder in UPII-SV40T transgenic mice

Urinary bladder cancer is the sixth most commonly diagnosed cancer and significant proportion of the patients diagnosed with bladder cancer have high-grade tumors that are at potential risk for post-surgical recurrence and metastasis, where 5-year survival is very low. Hence it is important to identify and develop regimens that prevent urothelial tumorigenesis. Inflammatory pathways particularly, cyclooxygenase (COX-2) and lipoxygenase (5-LOX) mediated metabolites are known to play important role in bladder tumor progression. Consistent with that epidemiological and clinical observations suggest that use of anti-inflammatory agents is associated with reduced risk for bladder cancer. Here we determined the chemopreventive efficacy of a Licofelone, a dual COX-LOX inhibitor, in a transgenic UPII-SV40T mouse model of bladder transitional cell carcinoma (TCC). Six-week old transgenic UPII-SV40T mice (n=30/group) were fed control (AIN-76A) or experimental diets containing 150 or 300 ppm licofelone for 34 weeks. At 40 weeks of age, all mice were euthanized; urinary bladders were collected to determine urothelial tumor weights and histopathological grading. Results suggest that bladders of the control diet fed transgenic mice weighed 3-5 fold more than that of the wild type mice. However, treatment of transgenic mice with licofelone led to a significant, dose dependent inhibition of the urothelial tumor weights (65.2 - 82.7%, p&lt;0.0001 in males; 35.0 - 49.0%, p&lt;0.0001 in females) compared to the control group. Importantly, mice fed licofelone diet significantly reduced development of invasive tumors. Urothelial tumor progression to invasive TCC was inhibited in both male (up to 50%; p&lt;0.01) and females mice (up to 46%; p&lt;0.003). Molecular analysis of urothelial tumors by immuno-histochemisty, qPCR and/or western immunoblotting for the expression of various markers that effect tumor growth and progression showed an increase in apoptosis (p53, p21, Bax, Caspase3, Annexin V) with a decrease in proliferation and angiogenesis (PCNA, COX2, 5LOX, mPGES2, VEGF) in the licofelone diet fed mice tumors. These results suggest that licofelone can serve as potential chemopreventive for bladder TCC. (Supported in part by NCI-CN53300)

Citation Format: Venkateshwar Madka, Altaf Mohammed, Qian Li, Yuting Zhang, Laura Biddick, Stanley Lightfoot, Xue-Re Wu, Levy Kopelovich, Vernon Steele, Chinthallapally V. Rao. Licofelone, a dual COX-LOX inhibitor prevents transitional cell carcinoma of urinary bladder in UPII-SV40T transgenic mice. [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 1244. doi:10.1158/1538-7445.AM2014-1244

Eflornithine (DFMO) prevents progression of pancreatic cancer by modulating ornithine decarboxylase signaling

Ornithine decarboxylase (ODC) is the key rate-limiting enzyme in the polyamine synthesis pathway and it is overexpressed in a variety of cancers. We found that polyamine synthesis and modulation of ODC signaling occurs at early stages of pancreatic precursor lesions and increases as the tumor progresses in Kras-activated p48(Cre/+)-LSL-Kras(G12D/+) mice. Interest in use of the ODC inhibitor eflornithine (DFMO) as a cancer chemopreventive agent has increased in recent years since ODC was shown to be transactivated by the c-myc oncogene and to cooperate with the ras oncogene in malignant transformation of epithelial tissues. We tested the effects of DFMO on pancreatic intraepithelial neoplasias (PanIN) and their progression to pancreatic ductal adenocarcinoma (PDAC) in genetically engineered Kras mice. The Kras(G12D/+) mice fed DFMO at 0.1% and 0.2% in the diet showed a significant inhibition (P < 0.0001) of PDAC incidence compared with mice fed control diet. Pancreatic tumor weights were decreased by 31% to 43% (P < 0.03-0.001) with both doses of DFMO. DFMO at 0.1% and 0.2% caused a significant suppression (27% and 31%; P < 0.02-0.004) of PanIN 3 lesions (carcinoma in situ). DFMO-treated pancreas exhibited modulated ODC pathway components along with decreased proliferation and increased expression of p21/p27 as compared with pancreatic tissues derived from mice fed control diet. In summary, our preclinical data indicate that DFMO has potential for chemoprevention of pancreatic cancer and should be evaluated in other PDAC models and in combination with other drugs in anticipation of future clinical trials.

Chemoprevention of urothelial cell carcinoma growth and invasion by the dual COX-LOX inhibitor licofelone in UPII-SV40T transgenic mice

Epidemiologic and clinical data suggest that use of anti-inflammatory agents is associated with reduced risk for bladder cancer. We determined the chemopreventive efficacy of licofelone, a dual COX-lipoxygenase (LOX) inhibitor, in a transgenic UPII-SV40T mouse model of urothelial transitional cell carcinoma (TCC). After genotyping, six-week-old UPII-SV40T mice (n = 30/group) were fed control (AIN-76A) or experimental diets containing 150 or 300 ppm licofelone for 34 weeks. At 40 weeks of age, all mice were euthanized, and urinary bladders were collected to determine urothelial tumor weights and to evaluate histopathology. Results showed that bladders of the transgenic mice fed control diet weighed 3 to 5-fold more than did those of the wild-type mice due to urothelial tumor growth. However, treatment of transgenic mice with licofelone led to a significant, dose-dependent inhibition of the urothelial tumor growth (by 68.6%-80.2%, P < 0.0001 in males; by 36.9%-55.3%, P < 0.0001 in females) compared with the control group. The licofelone diet led to the development of significantly fewer invasive tumors in these transgenic mice. Urothelial tumor progression to invasive TCC was inhibited in both male (up to 50%; P < 0.01) and female mice (41%-44%; P < 0.003). Urothelial tumors of the licofelone-fed mice showed an increase in apoptosis (p53, p21, Bax, and caspase3) with a decrease in proliferation, inflammation, and angiogenesis markers (proliferating cell nuclear antigen, COX-2, 5-LOX, prostaglandin E synthase 1, FLAP, and VEGF). These results suggest that licofelone can serve as potential chemopreventive for bladder TCC.

Raloxifene and antiestrogenic gonadorelin inhibits intestinal tumorigenesis by modulating immune cells and decreasing stem-like cells

Studies suggest that estrogen plays a contributing role in colorectal cancer. This project examined the preventive effects of raloxifene, a selective estrogen receptor modulator (SERM), and gonadorelin, an antiestrogenic drug, in female Apc(Min/+) mouse intestinal tumorigenesis. Six-week-old Apc(Min/+)mice were fed diet containing 1 ppm raloxifene or control diet. Gonadorelin (150 ng/mouse) was injected subcutaneously into one treatment group. Intestinal tumors were evaluated for tumor multiplicity and size. Mice treated with raloxifene and gonadorelin showed colon tumor inhibition of 80% and 75%, respectively. Both drugs significantly inhibited small intestinal tumor multiplicity and size (75%-65%, P < 0.0001). Raloxifene and gonadorelin showed significant tumor inhibition with 98% and 94% inhibition of polyps >2 mm in size. In mice fed with raloxifene or injected with gonadorelin, tumors showed significantly reduced proliferating cell nuclear antigen expression (58%-65%, P < 0.0001). Raloxifene treatment decreased β-catenin, cyclin D1, laminin 1β, Ccl6, and stem-like cells (Lgr 5, EpCAM, CD44/CD24), as well as suppressed inflammatory genes (COX-2, mPGES-1, 5-LOX,). Gonadorelin showed significant decrease in COX-2, mPGES-1, iNOS, and stem-like cells or increased NK cells and chemokines required for NK cells. Both drugs were effective in suppressing tumor growth albeit with different mechanisms. These observations show that either suppression of estrogen levels or modulation of estrogen receptor dramatically suppresses small intestinal and colonic tumor formation in female Apc(Min/+) mice. These results support the concept of chemoprevention by these agents in reducing endogenous levels of estrogen or modulating ER signaling.

Chemopreventive effects of an HDAC2-selective inhibitor on rat colon carcinogenesis and APCmin/+ mouse intestinal tumorigenesis

Epigenetic modulators, particularly histone deacetylases (HDACs), are valid targets for cancer prevention and therapy. Recent studies report that HDAC2 overexpression is associated with colon tumor progression and is a potential target for colon cancer prevention. This study tested chemopreventive and dose-response effects of Ohio State University HDAC42 (OSU-HDAC42), a selective HDAC2 inhibitor, using a rat colon carcinogenesis model to assess aberrant crypt foci inhibition and a familial adenomatous polyposis model to assess intestinal tumor inhibition. Colonic aberrant crypt foci were induced by azoxymethane (AOM) (15 mg/kg body weight, once-weekly subcutaneous injections at 8 and 9 weeks age). One week after AOM treatment, groups of rats were fed an AIN-76A diet containing 0, 75, 150, and 300 ppm OSU-HDAC42 for 8 weeks, and colonic aberrant crypt foci were evaluated. To assess the inhibitory effect of OSU-HDAC42 on small-intestinal polyps and colon tumor growth, 6-week-old male C57Bl/6J-APC(min/+)mice were fed an AIN-76A diet containing 150 ppm OSU-HADC42 or 300 ppm pan-HDAC inhibitor suberoylanilide hydroxyamic acid (SAHA) for 80 days. Our results demonstrate that dietary OSU-HDAC42 produced dose-dependent inhibition of AOM-induced colonic aberrant crypt foci formation (13-50%; P < 0.01 to < 0.0001) and reduced multiple crypts with ≥ 4 crypts per focus (25-57%; P < 0.01 to < 0.0001) in F344 rats. Our findings show that 150 ppm OSU-HDAC42 significantly inhibited small-intestinal polyps (>46%; P < 0.001), with polyp size measuring >1 mm (P < 0.001), and colon tumors (>26%) in APC(min/+)mice, whereas 300 ppm SAHA showed nonsignificant inhibition. Mice fed 150 ppm OSU-HDAC42 had significantly decreased HDAC2, proliferating cell nuclear antigen, B cell lymphoma 2, cyclin-dependent kinase 2, and cell division cycle homolog 25C expression levels and increased p53 expression levels. These observations demonstrate the chemopreventive efficacy of OSU-HDAC42 against chemically induced and polyposis models of intestinal tumorigenesis.

Abstract A15: Chemopreventive efficacy of Phospho-Ibuprofen, Rosuvastatin and their combination on AOM-induced colon adenocarcinoma formation in F344 rats

Phospho-Ibuprofen (P-I) is a derivative of ibuprofen designed to reduce the traditional toxicities of non-steroidal anti-inflammatory drugs (NSAIDs). P-I is studied for its anti-inflammatory and cancer properties in arthritis, breast cancer models and showed better gastrointestinal safety compared to NSAIDs. Statins has been effective for cholesterol lowering and protecting cardiovascular diseases in addition to its antineoplastic effects in preclinical and clinical observations. A promising strategy to enhance the cancer preventive efficacy of statins and NSAIDs in combination is to produce synergy without any unwanted side effects. Hence, experiments were designed to evaluate the chemopreventive efficacies of P-I and Rosuvastatin, which were administered individually and in combination on azoxymethane (AOM)-induced colon cancer formation in F344 rats. Male F344 rats (~30-45 animals/group) were fed AIN-76A diet and colon tumors were induced with two weekly doses of AOM (15 mg/kg body wt). Eight weeks after the AOM-treatment, groups of rats were fed AIN-76A diets containing ibuprofen (200 ppm), P-I (360 and 720 ppm), Rosuvastatin (50 and 100 ppm), or their low dose combinations for 40 weeks. Colonic tumors were evaluated histopathologically as invasive and noninvasive adenocarcinomas (AdCa) and modulating effects of P-I, and Rosuvastatin and combinations were studied on markers of colon tumor cell proliferation and apoptosis.

Results: Administration of P-I at 720 ppm significantly suppressed AOM-induced colon non-invasive and invasive AdCa formation (multiplicity (Mean±SEM): Non-invasive AdCa: Untreated, 1.37±0.22; P-I treated, 0.70±0.14 (p&lt;0.006); Invasive AdCa, Untreated, 2.22±0.35; P-I treated, 1.27±0.20 (p&lt;0.01). Rosuvastatin showed significant inhibition of noninvasive AdCa [50 ppm 1.43±0.21 (p&lt;0.03); 100 ppm 1.06±0.18 (p&lt;0.003)]. Importantly, low dose combination of 360 ppm P-I + 50 ppm Rosuvastatin showed significant synergistic/additive effect on the inhibition of colon non-invasive (44.5%, p&lt;0.016) and invasive AdCa (58.2%, p&lt;0.0002) multiplicity, suggesting a more pronounced effect on invasive AdCa. Whereas administration of 200 ppm Ibuprofen equalant to 360 ppm P-I failed to show any significant protective (p&gt;0.05) effect on AOM-induced AdCa multiplicity or incidence. Proliferation markers, proliferating cell nuclear antigen (PCNA), Cdk2, Cdc25C and Cav1, in tumors of rats exposed to P-I, Rosuvastatin and/or combinations were significantly suppressed. Also, colonic tumors from rats fed combination diet showed significant suppression of Erk and pErk protein expression as compared to colon tumors from rats fed the control diet. This is the first report on the combination using low-dose P-I and Rosuvastatin, which significantly suppressed the colon adenocarcinomas. Our results suggest that low-dose P-I with Rosuvastatin might potentially be a useful combination for colon cancer prevention/treatment in high risk individuals. (Supported by NCI-CN-N01-53300).

Citation Format: Naveena B. Janakiram, Altaf Mohammed, Yuting Zhang, Misty Brewer, Taylor Bryant, Laura Biddick, Stan Lightfoot, Vernon E. Steele, Chinthalapally V. Rao. Chemopreventive efficacy of Phospho-Ibuprofen, Rosuvastatin and their combination on AOM-induced colon adenocarcinoma formation in F344 rats. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A15.

β-Escin inhibits NNK-induced lung adenocarcinoma and ALDH1A1 and RhoA/Rock expression in A/J mice and growth of H460 human lung cancer cells

Lung cancer is the leading cause of cancer-related deaths. β-Escin, a triterpene saponin isolated from horse chestnut seeds, was tested for inhibition of lung adenoma and adenocarcinoma induced by the tobacco carcinogen 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in female A/J mice; and its possible mode of action was evaluated using the H460 human lung cancer cell line. At 6 weeks of age, 35 mice were fed AIN-76A-modified diet, and one week later, lung tumors were induced with a single intraperitoneal (i.p.) injection of 10 μmol NNK/mouse. Three weeks after the NNK treatment, groups of mice were fed either control or experimental diets containing 500 ppm for 20 weeks (10 control, 5 β-escin) or 36 weeks (15 control, 5 β-escin) and evaluated for lung tumor via histopathologic methods. Administration of 500 ppm β-escin significantly suppressed lung tumor (adenoma + adenocarcinoma) formation by more than 40% (P < 0.0015) at 20 weeks and by 53.3% (P < 0.0001) at 37 weeks. β-Escin inhibited NNK-induced lung adenocarcinoma formation by 65% (P < 0.001) at 20 weeks and by 53% (P < 0.0001) at 37 weeks. Immunohistochemical analysis revealed that lung tumors from mice exposed to β-escin showed significantly reduced aldehyde dehydrogenase (ALDH)1A1 and phospho-Akt (p-Akt) expression when compared with those in mice fed control diet. Aldefluor assay for ALDH revealed that among H460 lung cancer cells treated with different concentrations of β-escin (0-40 μmol/L), the subpopulation of cells with elevated ALDH activity was inhibited significantly. Our findings suggest that β-escin inhibits tobacco carcinogen-induced lung tumor formation by modulating ALDH1A1-positive cells and RhoA/Rock signaling.

Abstract LB-182: Licofelone inhibits NNK-induced lung adenocarcinoma formation in A/J mice by suppressing COX/LOX and inhibits human lung cancer cell growth by p21 up-regulation

Lung cancer is the leading causes of cancer deaths. Inflammation plays an important role in lung tumor progression; in that eicosanoids levels derived from cyclooxygenase (COX)-2 and 5-lipoxygenase (LOX) positively influence the tumor growth. We have evaluated chemopreventive effects of a novel dual LOX/ COX inhibitor, Licofelone {[6-(4-chlorophenyl)-2,2-dimethyl-7-phenyl-2,3-dihydro-1H-pyrrolizin-5-yl] acetic acid on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung adenoma and adenocarcinoma formation in female A/J mice and its possible mode of action was evaluated using human lung cancer cell line A549. For bioassay, at 6 weeks of age, mice were randomized and fed control AIN-76A modified diet. At 7 weeks of age (25-mice/group) intended for carcinogen treatment received one dose of 10 μmol NNK /mouse by i.p. injection. Three weeks after the NNK treatment, groups intended for Licofelone treatment were administered 200 and 400 ppm in diet for either 17 weeks (10 mice/group) and/or 34 weeks (15 mice/group) to assess efficacy against lung adenoma and adenocarcinoma. Intervention with 200 or 400 ppm Licofelone significantly suppressed lung adenomas by 29% (p&lt;0.004) and 38.3% (p&lt;0.0004); lung adenocarcinoma by 46% (p&lt;0.0005) and 62% (p&lt;0.0001), respectively after 17 weeks exposure. Also, dietary 200 and 400 ppm Licofelone significantly (p&lt;0.0001) suppressed lung adenocarcinomas by 40% and 56%, respectively, after 34 weeks exposure. These results suggest that licofelone a dual 5LOX/COX inhibitor inhibits the NNK induced lung adenomas and more so by suppressing adenocarcinoma formation in a dose-dependent manner. IHC analysis of lung tumors from NNK treated mice exposed to licofelone showed a significantly reduced proliferating cell nuclear antigen (PCNA) positive index, increased TUNEL positive cells and p21 expression as compared to lung adenocarcinomas from NNK treated mice fed with control diet. Treatment with Licofelone significantly suppressed both COX and 5-LOX expression and its metabolite formation in NNK induced lung tumors and human lung cancer cell line growth inhibition was associated with p21-upregulation. These findings suggest that dietary Licofelone inhibits tobacco carcinogen-induced lung adenoma and adenocarcinoma formation in a dose-dependent manner by modulating COX-2 and 5-LOX activities. {Supported by NIH, NCI grants NO1-CN-53300 and Kerley-Cade Chair}

Citation Format: Jagan Mohan Reddy Patlolla, Levy Kopelovich, Li Qian, Laura Biddick, Yuting Zhang, Dhimant Desai, Shantu Amin, Stan Lightfoot, Chinthalapally V. Rao. Licofelone inhibits NNK-induced lung adenocarcinoma formation in A/J mice by suppressing COX/LOX and inhibits human lung cancer cell growth by p21 up-regulation. [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 LB-182. doi:10.1158/1538-7445.AM2013-LB-182

Abstract 186: Clinically relevant low dose combination of rosuvastatin and difluoromethylornithine provides effective chemopreventive efficacy against AOM-induced colon cancers in F344 rats

Preclinical and clinical studies suggest that statins and polyamine inhibitors suppress growth, invasion and progression of malignant colon tumors. Experiments were designed to evaluate the human clinical relevant doses of Rosuvastatin and Difluromethylornithine (DFMO), individually and in combination, on azoxymethane (AOM)-induced colon adenocarcinomas (AdCa) in male F344 rats. Eight weeks of age, rats (30-36/group) treated with AOM to induce the colonic tumors and nine weeks after the AOM treatment, groups of rats were fed AIN-76A diets containing Rosuvastatin (50 or 100 ppm), DFMO (500 or 1000 ppm), or their low dose combination for an additional 40 weeks. AOM-treated rats fed control diet showed AdCa multiplicity of 3.59 ± 0.48 (Mean ±SEM) and AdCa incidence of 96.6 %. 50 or 100 ppm Rosuvastatin significantly suppressed AdCa multiplicities (29%, p&lt;0.046 and 42%, p&lt;0.007, respectively). 100 ppm Rosuvastatin, but not the lower dose, significantly inhibited colon AdCa incidence (p&lt;0.02) and caused &gt;52% (p&lt;0.003) more inhibition of invasive AdCa multiplicity. As anticipated, DFMO at both doses significantly inhibited AdCa multiplicity (p&lt;0.003 - p&lt;0.0001) and incidence (p&lt;0.05-0.001) as compared to control diet. The combination of low-dose Rosuvastatin plus low dose DFMO suppressed colon AdCa multiplicity by 76% (p&lt;0.0001) as compared to low-dose Rosuvastatin (29%) and low-dose DFMO (46%), suggesting an additive effect. This low dose combination also resulted in delay of colonic AdCa progression, as revealed by the presence of a higher number of adenomas in the treated group as compared to the low adenoma/high AdCa occurrence in the control diet group. DFMO, Rosuvastatin and/or combinations caused significantly decreased expression of cyclin E, cdk2, cav-1, laminin 1β, and mutant p53 proteins, and increased expression of wild type p53, cdc25c and p21 compared to control tumors by Western immunoblotting and Immunohistochemistry. The inflammatory markers IL-6, stat3, and COX-2 and the proliferation markers β-catenin and cyclin D1 also were down-regulated significantly in tumors of rats fed low-dose combinations as compared to low doses of Rosuvastatin or DFMO alone. This first report on combination treatment using clinically relevant doses of statin plus DFMO shows significant suppression of colon AdCa. Further studies are warranted using low-dose combinations of Rosuvastatin and DFMO in individuals at high risk for colon cancer. (Supported by R01-CA-94962 & NCI-CN-N01-53300)

Citation Format: Naveena B. Janakiram, Altaf Mohammed, Taylor Bryant, Yuting Zhang, Misty Brewer, Ashley Duff, Laura Biddick, Stan Lightfoot, Vernon Steele, Chinthalapally V. Rao. Clinically relevant low dose combination of rosuvastatin and difluoromethylornithine provides effective chemopreventive efficacy against AOM-induced colon cancers in F344 rats . [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 186. doi:10.1158/1538-7445.AM2013-186

Abstract LB-177: A supercritical turmeric extract prevents small intestinal and colonic tumors in the APCMin/+ mice by suppressing proliferation and cancer stem cell markers

CRC is one of the most commonly diagnosed cancers in the United States. Curcumin, a principle compound in turmeric, has been extensively investigated and proven to be antiinflammatory and anticarcinogenic against numerous cancers including CRC. Turmeric is consumed as a dietary ingredient by large populations and turmeric extracts as a dietary supplement by healthy as well as high-risk individuals with various chronic diseases. Turmeric, however, contains over 300 different compounds including essential oils; curcuminoids, turmerones, etc. Most turmeric extracts commonly used as dietary supplements contains &lt;6% curcuminoids; however, to date no studies have been undertaken to determine whether these turmeric extracts are effective or not in comparison to curcumin in preventing colonic tumors. In this study, we tested a supercritical extract of turmeric (TurmericForce™) in comparison to an equal amount of curcumin against the APC-min/+ SI and colon polyposis model. Six-week-old male APC-Min/+ mice (n = 15 per group) were fed with control AIN-76A diet or diets containing 2,000 ppm turmeric extract or 2,000 ppm or 120 ppm curcumin for 14 weeks; intestinal tumors were then evaluated for tumor incidence and multiplicity. Mice fed with either 2,000 ppm turmeric extract or curcumin exhibited a significantly suppressed SI polyp multiplicity by 26.3 ±8.3 (Mean±SD; 45.5%, p&lt;0.0001) and 32.5 ±7.8 (32.5%, P&lt;0.0001), respectively. Importantly, the 2,000 ppm turmeric extract showed significantly (p&lt;0.026) better inhibitory effect compared to 2,000 ppm curcumin in SI polyp suppression. Colon tumor incidences were 77%, 54%, and 50% for mice fed control, turmeric extract and curcumin, respectively. Furthermore, colonic tumor multiplicities were 1.46 ± 1.1 (control); 0.57± 0.6 (turmeric extract, 61%inhibition, p&lt;0.01) and 0.61±0.65 (2,000 ppm curcumin, 56% inhibition, p&lt;0.015). In contrast, 120 ppm curcumin (equal to curcumin content in turmeric extract) produced limited SI tumor inhibitory effects (14% inhibition) in APC-Min/+ mice. Both turmeric extract and curcumin showed a significant reduction is PCNA and β-catenin expression levels and an increase in p21 and TUNEL positive cells. Also, Real time PCR and IHC analysis showed a significant reduction in cancer stem (CD133 and ALDH1) marker positive cells by the turmeric extract and curcumin. These results suggest that the supercritical turmeric extract had equal or better chemopreventive properties than curcumin alone in suppressing intestinal tumorigenesis. {Supported by Kerley-Cade Endowment}

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-177. doi:1538-7445.AM2012-LB-177