Effects of talactoferrin alpha on lung adenoma prevention in A/J mice June 2, 2016

Talactoferrin alpha is a promising non-toxic solid tumor cancer agent that met with success in the treatment of early-stage lung cancer clinically in humans. It is well-tolerated, anddendritic cell-stimulation is a target. We tested the efficacy of this agent in a chemoprevention setting in A/J mice. All groups received benzo[a]pyrene (B[a]P) by oral gavage in three doses of 3 mg/kg body weight over the course of one week. Animals were then randomized into 5 groups of 24 mice per group based on weight. Experimental diets oftalactoferrin alpha (Agennix Inc., Indianapolis, IN), at 1.40% and 0.42% of the diet, were started one week or eight weeks after the last dose of B[a]P. Animals were continued on the feeding schedule, weighed weekly, and monitored for toxicity. The study was concluded 16 weeks after administration of B[a]P. The agent was well-tolerated for the duration of the experiment and there was no observable toxicity or weight change. The average number of adenomas per animal was 14.04 ± 0.93 (N=24) in the control group, 18.14 ± 1.45 (N=22) in the early low-dose group, 16.70 ± 1.30 (N=23) in the late low-dose group, 15.09 ± 1.41 (N=23) in the early high-dose group and 14.46 ± 1.21 (N=24) in the late high-dose group. We conclude talactoferrinalpha is well-tolerated. However, it did not inhibit carcinogenesis at a dose of 1.4% or 0.42% of the diet, which equates to human doses of 1.12 g/kg/day or 0.336 g/kg/day.

Thiazolidinediones abrogate cervical cancer growth

Peroxisome proliferator-activated receptor gamma (PPAR γ) is activated by thiazolidinedione drugs (TZDs) and can promote anti-cancer properties. We used three TZDs (pioglitazone, rosiglitazone, and ciglitazone) to target cervical cancer cell lines and a nude mouse animal model. Each agent increased activation of PPAR γ, as judged by a luciferase reporter gene assay in three HPV-associated cell lines (CaSki, SiHa, and HeLa cells) while decreasing cellular proliferation in a dose-dependent manner. They also promoted Oil Red O accumulation in treated cell lines and upregulated the lipid differentiation marker adipsin. Interestingly, xenograft HeLa tumors in nude mice treated with 100mg/kg/day pioglitazone exhibited decreased growth compared to control mice or mice treated with standard cervical chemotherapy. In conclusion, TZDs slow tumor cell growth in vitro and in vivo with decreases in cell proliferation and increases in PPAR γ and adipsin. These agents may be interesting treatments or treatment adjuncts for HPV-associated cancers or perhaps even precancerous conditions.

Fixed-Dose Combinations of Pioglitazone and Metformin for Lung Cancer Prevention

Combination treatment with pioglitazone and metformin is utilized clinically in the treatment of type II diabetes. Treatment with this drug combination reduced the development of aerodigestive cancers in this patient population. Our goal is to expand this treatment into clinical lung cancer chemoprevention. We hypothesized that dietary delivery of metformin/pioglitazone would prevent lung adenoma formation in A/J mice in a benzo[a]pyrene (B[a]P)-induced carcinogenesis model while modulating chemoprevention and anti-inflammatory biomarkers in residual adenomas. We found that metformin (500 and 850 mg/kg/d) and pioglitazone (15 mg/kg/d) produced statistically significant decreases in lung adenoma formation both as single-agent treatments and in combination, compared with untreated controls, after 15 weeks. Treatment with metformin alone and in combination with pioglitazone resulted in statistically significant decreases in lung adenoma formation at both early- and late-stage interventions. Pioglitazone alone resulted in significant decreases in adenoma formation only at early treatment intervention. We conclude that oral metformin is a viable chemopreventive treatment at doses ranging from 500 to 1,000 mg/kg/d. Pioglitazone at 15 mg/kg/d is a viable chemopreventive agent at early-stage interventions. Combination metformin and pioglitazone performed equal to metformin alone and better than pioglitazone at 15 mg/kg/d. Because the drugs are already FDA-approved, rapid movement to human clinical studies is possible. Cancer Prev Res; 10(2); 116-23. ©2017 AACR.

Safety and Preclinical Efficacy of Aerosol Pioglitazone on Lung Adenoma Prevention in A/J Mice

Pioglitazone is a PPARγ agonist commonly prescribed for the clinical treatment of diabetes. We sought to expand its use to lung cancer prevention in a benzo[a]pyrene (B[a]P) mouse model with direct lung delivery via inhalation. Initially, we conducted inhalational toxicity experiments with 0, 15, 50, 150, and 450 μg/kg body weight/day pioglitazone in 40 A/J mice. We examined the animals for any physical toxicity and bronchoalveolar lavage fluids for inflammatory and cytotoxicity markers. Doses up to and including 450 μg/kg bw/d failed to demonstrate toxicity with aerosol pioglitazone. For chemoprevention experiments, A/J mice were randomized to treatment groups of inhaled doses of 0, 50, 150, or 450 μg/kg bw/d pioglitazone 1 or 8 weeks after the last dose of B[a]P. For the early treatment group, we found up to 32% decrease in lung adenoma formation with 450 μg/kg bw/d pioglitazone. We repeated the treatments in a second late-stage experiment and found up to 44% decreases in lung adenoma formation in doses of pioglitazone of 150 and 450 μg/kg bw/day. Both the early- and the late-stage experiments demonstrated biologically relevant and statistically significant decreases in adenoma formation. We conclude that aerosol pioglitazone is well-tolerated in the A/J mouse model and a promising chemoprevention agent for the lower respiratory tract. Cancer Prev Res; 10(2); 124-32. ©2016 AACR.

Correlation analysis of oral lesion sizes by various standardized criteria

OBJECTIVE

Requirements of an NCI contract examining a novel treatment for leukoplakia were to compare standard bi-dimensional measurement of oral lesions to examine for correlation with Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and to examine the feasibility of digital image analysis for automated measurements.

STUDY DESIGN

Retrospective review.

METHODS

We examined 13 patients by bi-dimensional measurement and compared these measurements to 1) RECIST criteria, 2) scalar digital measurements using a standardized measuring device within the photograph, and 3) pixel number.

RESULTS

RECIST criteria correlated (r-squared=0.8535, p<0.0001) with bi-dimensional measurements. Digitized measures in photographs correlated with bi-dimensional measurements (r-squared=0.6661, p=0.0007), but were time consuming. There was minimal to no correlation between pixel number in Adobe Photoshop and the other measures.

CONCLUSION

Bi-dimensional measurement of oral leukoplakia and RECIST criteria are highly correlated. Digital photography measurements, though highly correlative, are very cumbersome. We recommend bi-dimensional or longest length measurement and a simple photograph as standard of documentation for leukoplakia lesions.

Abstract 2611: Effects of chalcones, nicotinamide, and resveratrol on PPAR gamma activation in oral cancer cells

Several classes of natural products have cancer prevention potential and PPAR gamma is an intriguing chemoprevention target as a nuclear receptor that controls multiple growth and differentiation processes. We have previously tested many classes of natural products in A/J mice and have found that the following chemoprevention compounds had no significant dietary toxicities: inositol, eucalyptol, chalcones, nicotinamides, and resveratrol. We tested these compounds for their capacity to activate PPAR gamma reporter genes in CA-9-22 oral cancer cells. In several repeated experiments we found that Inositol hexaphosphate did not activate PPAR gamma reporter genes at high concentrations of 1-4 mM. We found that eucalyptol, trans-Chalcone, 4 methoxy chalcone, Nicotinic Acid, and Nicotinamide had the capacity for statistically significant activation of PPAR gamma reporter genes in oral cancer cells from 20-60% at concentrations of 1-100 uM. We found that resveratrol was the most potent agent and could activate PPAR gamma reporter genes 2 fold. As a reference, this was about half the activity of the prototypic PPAR gamma activator pioglitazone. We performed additional experiments with resveratrol and found that it could activate the PPAR gamma dependent squamous differentiation gene Involucrin in oral cancer cells and BEAS 2B cells. Additionally, resveratrol significantly decreased BEAS 2 B proliferation from 48-96 hours at concentrations of 10 uM. From this data we conclude that resveratrol has the capacity to activate PPAR gamma in vitro and resveratrol and its derivatives may also function as PPAR gamma activators as an additional mechanism of action. We also conclude that inositol, eucalyptol, chalcones, and nicotinamides do not activate PPAR gamma.

Citation Format: Jennifer Diaz, Beverly Wuertz, Art Galbraith, Frank G. Ondrey. Effects of chalcones, nicotinamide, and resveratrol on PPAR gamma activation in oral cancer cells. [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 2611.

Induction of Heat Shock Protein 70 Inhibits NF-kappa-B in Squamous Cell Carcinoma

OBJECTIVE: To determine the relationship between heat shock proteins (HSPs) and the proinflammatory, anti-apoptosis mediator NF-kappa-B in squamous cell carcinoma.

STUDY DESIGN AND SETTING: CA-9-22 cells were exposed to heat stress to induce the production of HSPs. Immunoblot and reporter gene experiments determined the inducibility of HSP production and the activation of cytokine-induced NF-kappa-B. Immunoblot experiments determined the presence of the inhibitor- k-B-α (I kBα).

RESULTS: CA-9-22 cells can be induced by heat stress to produce HSPs at 100-fold above baseline levels. The induction of HSPs prevents the activation and nuclear translocation of NF-kappa-B despite stimulation with IL-1β and TNF-α.

CONCLUSIONS: Constitutive activation of NF-kappa-B is prevented by HSP induction through an increase in I kBα synthesis.

SIGNIFICANCE: The induction of HSP70 alters the inflammatory milieu associated with squamous cell carcinoma progression through the inhibition of NF-kappa-B and may ultimately promote apoptosis in head and neck carcinoma.

PPAR Activation and Decreased Proliferation in Oral Carcinoma Cells With 4-HPR

OBJECTIVE: To explore whether the mechanism of action of 4-hydroxyphenylretinamide (4-HPR, fenretidine), a synthetic retinoid, involves the functional activation of the nuclear hormone receptor class known as PPARs (peroxisome proliferator-activated receptors). Also, to examine whether anti-proliferative effects of this agent in head and neck cancer cells occur at biologically relevant concentrations.

STUDY DESIGN/METHODS: CA 9–22, NA, and UM SCC 11B cells were treated with 4-HPR during their log phase growth and functional activation of PPAR γ was evaluated by plate luminometry. Cellular proliferation was analyzed by standard MTT cell proliferation assays and cell counting. Student's t tests were performed for all experiments.

RESULTS: Significant dose-dependent increases in PPAR γ activation occurred in response to 4-HPR treatment. Proliferation was significantly inhibited by 4-HPR in a dose-dependent manner as judged by MTT and cell counting assays. These effects occurred at equimolar concentrations in both types of experiments within a range of clinically achievable doses (1–4 μM) of 4-HPR.

CONCLUSIONS: 4-HPR can functionally activate PPAR γ at clinically achievable doses. Decreased cancer cell proliferation secondary to PPAR γ activation has been observed in other malignancies as well as upper aerodigestive cancer. PPAR γ activation by 4-HPR represents another potential anti-cancer mechanism of action for this drug.

CLINICAL SIGNIFICANCE: PPAR γ activation represents a novel target for anti-cancer therapy for head and neck cancer and the current level of clinical toxicity of 4-HPR would be judged acceptable to utilize this agent alone or in combination chemotherapy.

Functional activation of PPARγ in human upper aerodigestive cancer cell lines

Upper aerodigestive cancer is an aggressive malignancy with relatively stagnant long-term survival rates over 20 yr. Recent studies have demonstrated that exploitation of PPARγ pathways may be a novel therapy for cancer and its prevention. We tested whether PPARγ is expressed and inducible in aerodigestive carcinoma cells and whether it is present in human upper aerodigestive tumors. Human oral cancer CA-9-22 and NA cell lines were treated with the PPAR activators eicosatetraynoic acid (ETYA), 15-deoxy-δ- 12,14-prostaglandin J2 (PG-J2), and the thiazolidinedione, ciglitazone, and evaluated for their ability to functionally activate PPARγ luciferase reporter gene constructs. Cellular proliferation and clonogenic potential after PPARγ ligand treatment were also evaluated. Aerodigestive cancer specimens and normal tissues were evaluated for PPARγ expression on gene expression profiling and immunoblotting. Functional activation of PPARγ reporter gene constructs and increases in PPARγ protein were confirmed in the nuclear compartment after PPARγ ligand treatment. Significant decreases in cell proliferation and clonogenic potential resulted from treatment. Lipid accumulation was induced by PPARγ activator treatment. 75% of tumor specimens and 100% of normal control tissues expressed PPARγ RNA, and PPARγ protein was confirmed in 66% of tumor specimens analyzed by immunoblotting. We conclude PPARγ can be functionally activated in upper aerodigestive cancer and that its activation downregulates several features of the neoplastic phenotype. PPARγ expression in human upper aerodigestive tract tumors and normal cells potentially legitimizes it as a novel intervention target in this disease. © 2016 Wiley Periodicals, Inc.

Abstract LB-264: Effects of dietary metformin/pioglitazone on lung adenoma formation in A/J mice

Introduction: Metabolomics and cancer chemoprevention are important contemporary concepts in cancer prevention and gaining traction as potential clinical trial topics. Our group has worked with type II diabetes agents clinically in oral cancer prevention and clinically and preclinically in both lung and head and neck cancer. Both pioglitazone and metformin are type II diabetes agents, and both drugs have promising epidemiologic evidence for efficacy as solid tumor prevention agents. They are well tolerated clinically for many years in millions of patients worldwide with acceptable toxicity profiles. We hypothesize these agents would be suitable in the chemoprevention setting and tested this hypothesis in experimental lung carcinogenesis in a benzo[a]pyrene (B[a]P) mouse model.

Materials and Methods: We utilized 224 seven week old female A/J mice. All groups received 3 weekly doses of B[a]P by oral intubation and were randomized into 8 groups of 27 mice per group based on weights. Experimental diets were started one week after the last dose of B[a]P. Metformin (12 mg/g and 10.2 mg/g) and/or pioglitazone (0.18mg/g) were administered in the diet for 18 weeks, whereas late stage inhibition diets were started at 8 weeks post carcinogen. Animals were continued on the feeding schedule, weighed weekly, and monitored for weight loss, behavior changes, rough hair coat, or other signs of ill health.

Results: The average number of adenomas per animal was 17.44 +/- 1.39 (SEM) in the control group. At the early stage intervention the average number of adenomas was 5.00 +/- 0.69 (P&lt;0.0001) in the highest dose of metformin, 6.15 +/- 0.57 (P&lt;0.0001) for the low dose metformin, and 11.92 +/-1.00 (P = 0.0023) for pioglitazone treatment. Metformin (low dose) and pioglitazone in combination resulted in 5.26 +/- 0.78 (P&lt;0.0001) adenomas per animal. At the late stage intervention the average number of adenomas was 10.89 +/- 1.161 (P = 0.0007) for the low dose metformin, and 14.42 +/-1.24 (P = 0.1126, not significant) for pioglitazone treatment. Metformin (low dose) and pioglitazone in combination resulted in 9.77 +/- 0.85 (P&lt;0.0001) adenomas per animal. The agents were well tolerated for the duration of the experiment from all physical appearance and other standard toxicities. However, animals treated with metformin had a 15% weight loss at the beginning of the experiment and completed the experiment with body weights 15% lower compared to non-metformin treated animals.

Conclusions: We conclude metformin and pioglitazone are promising agents for lung adenoma prevention in A/J mice. We also conclude dose adjustments of these drugs may require further optimization. Drugs of the thiazolidinedione class and sulfonylureas are powerful controllers of glucose metabolism. Although we did not have observable toxicity in the animals, it is likely glucose metabolism was altered and this contributed to the 15% differences in weight between the animal groups. Therefore, well designed metabolomic studies may be helpful in the future.

Citation Format: Donna Seabloom, Art Galbraith, Beverly Wuertz, Anna Haynes, Mark S. Miller, Vernon Steele, Lee Wattenberg, Frank G. Ondrey. Effects of dietary metformin/pioglitazone on lung adenoma formation in A/J 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 LB-264. doi:10.1158/1538-7445.AM2015-LB-264

Abstract 914: Pioglitazone and metformin as potential chemopreventative treatments in Fanconi anemia related oral squamous carcinoma

Fanconi anemia (FA) is a genetic disorder which leads to bone marrow failure and cancer due to mutations in DNA repair mechanisms. FA is also a solid tumor-prone disease, affecting patients decades earlier and at a rate several hundred-fold higher than the general population necessitating regular cancer surveillance. To better understand the features of post-BMT oral SCC tumors and assist in development of preventative, survival-enhancing therapies for FA patients, we established a cell line and treated it with a panel of emerging chemopreventatives and natural compounds. An adjunct therapy with a minimal side effect profile will help this population in which chemotherapy and radiation are particularly damaging.

We established a cell line from a post bone marrow transplant FA patient with a T2N2bM0 oral SCC grown as an adherent monolayer culture. The chemopreventative compound panel we used included Pioglitazone and Metformin. We also tested the synthetic retinoid Bexarotene, and commonly used chemotherapeutics Taxol and Cisplatin. MTT assays determined cell viability after 1, 2, and 3 days of treatment. Clonogenic assays were performed to determine survival and proliferation over 1-2 weeks. Reporter gene assays were performed to determine the effect of treatments on several target genes, to investigate pathway response and potential candidate biomarkers.

Our results show Pioglitazone at all concentrations (5, 10, 20, 40μM) decreases cell proliferation compared to solvent controls (P&lt;0.0001). Metformin (1 - 100μM) unexpectedly increased cell proliferation or was otherwise equal in growth with the controls, with the exception of the high dose (10mM) which decreased cell proliferation (P&lt;0.0001). Taxol, Cisplatin, and Bexarotene were also found to decrease cell proliferation in a dose-dependent manner. Clonogenic assays demonstrated dose-dependent decreases in colony forming ability with Pioglitazone and Bexarotene, however no significant changes were shown with Metformin treatments. Reporter gene assays revealed that PPAR ligand binding activity was upregulated in FA cells treated with Pioglitazone (P&lt;0.02 at 40μM, P = 0.0003 at 10μM) compared to controls. Conversely PPAR activity was decreased compared to controls in FA cells treated with Metformin (P&lt;0.0001 for all concentrations of Metformin) and Bexarotene (P&lt;0.0001 for all concentrations of Bexarotene 1, 2, 4μM).

Pioglitazone seems to be a promising chemopreventative adjunct treatment for HNSCC in FA patients. Further studies are underway to evaluate the contribution of decreased cell proliferation versus apoptotic mechanisms. Metformin does not appear to decrease tumor cell proliferation at doses up to 100 uM in our FA cell line.

Citation Format: Kim Miller, Beverly Wuertz, Frank G. Ondrey. Pioglitazone and metformin as potential chemopreventative treatments in Fanconi anemia related oral squamous carcinoma. [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 914. doi:10.1158/1538-7445.AM2015-914

Abstract 2174: Association of diabetes and obesity with risk of esophageal and gastric adenocarcinoma in the Iowa Women's Health Study (IWHS)

Incidence rates of esophageal and gastric cancers have increased rapidly in developing countries during the past four decades. The rate of esophageal adenocarcinomas has approximately tripled among US whites and now exceeds that of esophageal squamous cell carcinomas. Incidence of gastric cardia adenocarcinomas has also risen significantly during this period, though to a lesser extent. These cancers often respond poorly to treatment, highlighting the importance of identifying modifiable risk factors with a view to prevention. The association between diabetes and gastroesophageal adenocarcinoma has been examined in only a few studies and findings are inconsistent. While obesity is a significant risk factor for esophageal and gastric adenocarcinomas, few analyses have been conducted in prospective cohorts. We examined the association between diabetes, BMI, and waist circumference and incidence of esophageal, non-cardia gastric and gastric cardia adenocarcinomas in a large prospective cohort of postmenopausal women. A mailed survey at baseline (1986) collected information on self-reported diabetes and anthropometric measures and included a detailed food-frequency questionnaire. The 34,466 initially cancer free women were followed for 24 years with annual cancer incidence obtained through the State Health Registry of Iowa, part of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program; 83 women developed gastroesophageal adenocarcinoma. Associations were examined using proportional hazards regression models: hazard ratios (HR) and 95% confidence intervals (CI) were calculated. Significant associations were observed in age-adjusted models for diabetes (yes/no) [HR: 2.09, 95% CI: 1.01-4.34], body mass index (kg per meters squared) [HR: 1.09, 95% CI: 1.03-1.15], and waist circumference (cm) [HR: 1.24, 95% CI: 1.01-1.53]. Additionally, a positive association between diabetes and adenocarcinoma of the gastroesophageal junction was found in both age-adjusted [HR: 3.43, 95% CI: 1.32-8.90] and multivariate-adjusted models [HR: 3.00, 95% CI: 1.13-7.99]. An inverse association was found with increasing daily fiber intake (g/day) and all gastroesophageal adenocarcinomas [HR: 0.84, 95% CI: 0.73-0.96]. These findings support the view that diabetes, body mass index and waist circumference increase risk of gastroesophageal adenocarcinoma while increased fiber intake may decrease risk.

Citation Format: Bryan P. LaBore, Anna E. Prizment, Frank G. Ondrey, Kristin E. Anderson. Association of diabetes and obesity with risk of esophageal and gastric adenocarcinoma in the Iowa Women's Health Study (IWHS). [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 2174. doi:10.1158/1538-7445.AM2014-2174

Abstract 2140: Efficacy of aerosolized pioglitazone in lung carcinogenesis in A/J mice

Pioglitazone is a PPAR gamma agonist commonly utilized clinically in the treatment of diabetes. There have been clinical trials with this agent in oral cancer prevention and we sought to potentially expand its use in lung cancer in a B[a]P mouse model. Directed epithelial delivery in lung cancer is an attractive treatment approach and we felt pioglitazone would be amenable to aerosol delivery. Initially, a maximum tolerated dose experiment examining standard toxicity parameters, including animal behavior characteristics, weight, general health, and increases in markers of cytotoxicity in bronchoalveolar lavage was conducted. We found no statistically significant indications of increased toxicity in the animals with administration of aerosolized pioglitazone and proceeded with the prevention protocol. We utilized 192 seven week old female A/J mice. All groups received Benzo[a]pyrene by oral gavage in 3 doses of 3mg/kg body weight over the course of 1 week. Animals were then randomized into 8 groups of 24 mice per group based on weight. Experimental diets, 0, 50, 150, and 450µg/kg body weight pioglitazone formulated into 0.6µm average diameter respiratory particles, were started 1 week or 8 weeks after last dose of B[a]P. Animals were continued on the feeding schedule, weighed weekly, and monitored for weight loss, attenuation, rough hair coat, or other signs of ill health. The study was concluded 16 weeks after administration of B[a]P. The agent was well tolerated for the duration of the experiment and there was no observable toxicity. The average number of adenomas per animal in the late treatment group was 10.69 ± 1.685 in the control, 12.27 ± 1.761 in the 50µg, 6.000 ± 0.6359 in the 150 µg, and 7.267 ± 1.071 in the 450µg groups but low control tumor counts in the early treatment group precluded analysis. The same tumor initation protocol was used with 72 mice. Animals were randomized into 3 groups of 24 animals and treated with 0, 150, or 450µg/kg body weight aerosol pioglitazone for 16 weeks starting 1 week after the last B[a]P dose. The average number of adenomas per animal was 9.217 ± 1.004 in the control, 7.957 ± 0.9440 in the in the 150 µg, and 6.304 ± 0.8653 in the 450µg groups. We conclude aerosol pioglitazone is well tolerated in the A/J mouse model and a promising chemoprevention agent in the aerodigestive tract.

Citation Format: Donna Seabloom, Art Galbraith, Beverly Wuertz, Anna Haynes, Jenny Antonides, alisha fujita, Vernon Steele, Lee Wattenberg, Frank G. Ondrey. Efficacy of aerosolized pioglitazone in lung carcinogenesis in 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 2140. doi:10.1158/1538-7445.AM2014-2140

Mechanism and efficacy of sub-50-nm tenfibgen nanocapsules for cancer cell-directed delivery of anti-CK2 RNAi to primary and metastatic squamous cell carcinoma

Improved survival for patients with head and neck cancers (HNC) with recurrent and metastatic disease warrants that cancer therapy is specific, with protected delivery of the therapeutic agent to primary and metastatic cancer cells. A further objective should be that downregulation of the intracellular therapy target leads to cell death without compensation by an alternate pathway. To address these goals, we report the utilization of a sub-50-nm tenfibgen (s50-TBG) nanocapsule that delivers RNAi oligonucleotides directed against the essential survival signal protein kinase CK2 (RNAi-CK2) in a cancer cell-specific manner. We have evaluated mechanism and efficacy of using s50-TBG-RNAi-CK2 nanocapsules for therapy of primary and metastatic head and neck squamous cell carcinoma (HNSCC). s50-TBG nanocapsules enter cancer cells via the lipid raft/caveolar pathway and deliver their cargo (RNAi-CK2) preferentially to malignant but not normal tissues in mice. Our data suggest that RNAi-CK2, a unique single-stranded oligonucleotide, co-opts the argonaute 2/RNA-induced silencing complex pathway to target the CK2αα' mRNAs. s50-TBG-RNAi-CK2 inhibited cell growth corresponding with reduced CK2 expression in targeted tumor cells. Treatment of three xenograft HNSCC models showed that primary tumors and metastases responded to s50-TBG-RNAi-CK2 therapy, with tumor shrinkage and 6-month host survival that was achieved at relatively low doses of the therapeutic agent without any adverse toxic effect in normal tissues in the mice. We suggest that our nanocapsule technology and anti-CK2 targeting combine into a therapeutic modality with a potential of significant translational promise.

Quantitative proteomic analysis of oral brush biopsies identifies secretory leukocyte protease inhibitor as a promising, mechanism-based oral cancer biomarker

A decrease in the almost fifty percent mortality rate from oral cancer is needed urgently. Improvements in early diagnosis and more effective preventive treatments could affect such a decrease. Towards this end, we undertook for the first time an in-depth mass spectrometry-based quantitative shotgun proteomics study of non-invasively collected oral brush biopsies. Proteins isolated from brush biopsies from healthy normal tissue, oral premalignant lesion tissue (OPMLs), oral squamous cell carcinoma (OSCC) and matched control tissue were compared. In replicated proteomic datasets, the secretory leukocyte protease inhibitor (SLPI) protein stood out based on its decrease in abundance in both OPML and OSCC lesion tissues compared to healthy normal tissue. Western blotting in additional brushed biopsy samples confirmed a trend of gradual decreasing SLPI abundance between healthy normal and OPML tissue, with a larger decrease in OSCC lesion tissue. A similar SLPI decrease was observed in-vitro comparing model OPML and OSCC cell lines. In addition, exfoliated oral cells in patients’ whole saliva showed a loss of SLPI correlated with oral cancer progression. These results, combined with proteomics data indicating a decrease in SLPI in matched healthy control tissue from OSCC patients compared to tissue from healthy normal tissue, suggested a systemic decrease of SLPI in oral cells correlated with oral cancer development. Finally, in-vitro experiments showed that treatment with SLPI significantly decreased NF-kB activity in an OPML cell line. The findings indicate anti-inflammatory activity in OPML, supporting a mechanistic role of SLPI in OSCC progression and suggesting its potential for preventative treatment of at-risk oral lesions. Collectively, our results show for the first time the potential for SLPI as a mechanism-based, non-invasive biomarker of oral cancer progression with potential in preventive treatment.

Not significant but important

Armstrong and colleagues report the result of a large Phase IIb randomized trial evaluating the effectiveness of a preparation of the Bowman Birk Inhibitor compared with an oral placebo in reversing the extent of oral leukoplakia as measured visually by pathology or a battery of intermediate end points. In this editorial, we review the report of this negative clinical trials result to highlight the clinical trial process used in evaluating this previously promising chemoprevention agent. Publishing this report is important to address concerns with publication bias. The challenges in running a chemoprevention trial are reviewed with suggestions to enhance progress going forward. Conceptually, developing drugs to intercept the early stages of carcinogenesis is very attractive, but progress in this area has been slow. Two opportunities to overcome this reality are discussed. These measures include the broader use of neoadjuvant, window-of-opportunity trials with new candidate chemoprevention agents to get more textured information about the mechanistic impact of the drug exposure in previously untreated early tumor tissue. In addition, we discuss the use of new intermediate end point markers such as with optical imaging tools to obtain a more objective and quantitative assessment of drug response.

Abstract 4865: Lack of efficacy of aerosolized resveratrol on B[A]P induced pulmonary adenoma formation in A/J mice

Natural products constitute an emerging class of compounds for carcinogenesis prevention in a variety of solid tumor malignancies. Resveratrol is a compound that has outstanding efficacy on cancer prevention in in vitro carcinogenesis models but rapid solubility and metabolism limits its efficacy in animal models when delivered in the diet. However, if regional or topical delivery could be achieved effects of first pass metabolism might be avoided. In the present study, we sought to use aerosol resveratrol to examine whether it could inhibit Benzpyrene inducd pulmonary adenoma formation in A/J mice. Eight groups of 24 mice were given Benzpyrene and aerosol resveratrol was started either one week or 8 weeks after the conclusion of the Benzpyrene. Aerosolized resveratrol (1.0, 0.3, and 0.1 mg/kg) was delivered 5x per week Monday through Friday for weeks 2- 15. At the conclusion of the experiment animals were sacrificed and adenomas counted. We found that the animals tolerated the aerosol resveratrol without toxicity and without weight differences between all groups. Animals formed between 9 and 12 adenomas, on average throughout all groups. There were no effects of aerosol resveratrol on either early stage or late stage carcinogenesis, nor were there any trends between the groups. We conclude that the high water solubility of resveratrol likely allowed for its rapid transit and metabolism through the bronchioles and lung parenchyma and that possibly chemical modifications of resveratrol that allow for its deposition in the lung fields in a way to increase its residence time would allow for better efficacy.

Citation Format: Donna Seabloom, Art Gailbraith, Jenny Antonides, Beverly Wuertz, Lee Wattenberg, Frank G. Ondrey. Lack of efficacy of aerosolized resveratrol on B[A]P induced pulmonary adenoma formation in A/J mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4865. doi:10.1158/1538-7445.AM2013-4865

Id2 regulates the proliferation of squamous cell carcinoma in vitro via the NF-κB/Cyclin D1 pathway

Squamous cell carcinoma (SCC) is a significant cause of cancer morbidity and mortality worldwide, with an incidence of up to 166 cases per 100 000 population. It arises in the skin, upper aerodigestive tract, lung, and cervix and affects more than 200 000 Americans each year. We report here that a microarray experiment comparing 41 SCC and 13 normal tissue specimens showed that Id2, a gene that controls the cell cycle, was significantly up-regulated in SCC. Enforced expression of Id2 in vitro stimulated the proliferation of SCC cells and up-regulated the transcription of nuclear factor kappa B (NF-κB) and cyclin D1. Enhancement of the NF-κB activity with p65 significantly increased the cell proliferation and the transcription of cyclin D1, whereas inhibition of the NF-κB activity with I kappa B alpha mutant (IκBα M) and pyrroline dithiocarbamate (PDTC) abrogated cell proliferation and transcription of cyclin D1. Furthermore, a mutated NF-κB binding site in the cyclin D1 promoter fully abrogated the Id2-induced transcription of cyclin D1. Taken together, these data indicate that Id2 induces SCC tumor growth and proliferation through the NF-κB/cyclin D1 pathway.

DeCIDE: A phase III randomized trial of docetaxel (D), cisplatin (P), 5-fluorouracil (F) (TPF) induction chemotherapy (IC) in patients with N2/N3 locally advanced squamous cell carcinoma of the head and neck (SCCHN)

5500

Background: IC is associated with lower distant failure (DF) rates in SCCHN but an improvement in overall survival (OS) has not been validated. The goal of this trial was to determine whether IC prior to chemoradiotherapy (CRT) improves survival compared to CRT alone. Methods: In this phase 3, open-label trial, subjects with pathologically confirmed SCCHN; N2/N3 disease without metastases; no prior therapy; KPS ³ 70%; and intact organ function were randomized to CRT alone (CRT arm) [5 days of D (25 mg/m2), F (600 mg/m2), hydroxyurea (500 mg BID), and RT (150 cGy BID) followed by a 9 day break] or to 2 cycles of IC [D (75 mg/m2), P (75 mg/m2), F (750 mg/m2 day 1-5)] followed by the same CRT (IC arm). Primary endpoint was OS. Secondary endpoints included DF free survival, failure pattern, and recurrence-free survival (RFS). 280 subjects provided 80% power to detect a hazard ratio HR=0.5 for OS (a=0.05). Results: 280 subjects were accrued from 2004-09 with minimum follow-up 24 months. Of 142 patients randomized to IC, 91% received 2 cycles and 87% continued to CRT. Treatment adherence during CRT was high for docetaxel and hydroxyurea, but fewer than 75% of the patients received target dose of 5FU in both arms. RT was delivered without major deviations in 94% and 95% of patients on IC and CRT arms, respectively. The most common grade 3-4 toxicities during IC were febrile neutropenia (9%) and mucositis (8%), and during CRT (both arms combined) they were mucositis (45%), dermatitis (19%), and leukopenia (17%). Only grade 3-4 leukopenia and neutropenia rates were significantly higher in IC (p=0.002 and p=0.02, respectively). Table shows efficacy. Conclusions: High survival rates were observed in both arms. Further analysis and follow-up may provide insight into why the significant decrease in DF did not translate into improved OS. [Table: see text]

A comparison of screening methods in two early phase oral leukoplakia clinical trials

OBJECTIVES/INTRODUCTION

Clinical trial accrual for oral dysplasia is difficult in the United States and elsewhere. Patients with dysplastic oral leukoplakia progress to frank invasive carcinoma at a rate of 5-37% over 5 years. We compared two clinical trial screening efforts to hopefully devise better accrual strategies to these types of clinical trials.

METHODS

For the first trial, we identified 244 patients with dysplastic oral leukoplakia in our university database and a media campaign. Patients were notified and screened by examination and biopsy. For the second clinical trial, we established a preneoplastic lesions clinic and teaching and communications network with regional oral healthcare professionals.

RESULTS

Only one of 244 patients accrued to the first clinical trial through an organized screening effort based on database/medical records review. The second clinical trial accrued 16/30 screened patients through redirected efforts in teaching, communications, and a preneoplastic lesions clinic.

CONCLUSION

We conclude that significant difficulties resulted from medical record/database review of leukoplakia patients as a screening method for leukoplakia clinical trial entry. We feel that persistent direct contact and education of healthcare professionals who are likely to examine leukoplakia patients improved accrual to the second clinical trial.

Abstract 601: PPARδ mediated p21 induction in aerodigestive preneoplastic cell lines

PPARδ activating strategies are currently being tested preclinically and clinically in aerodigestive cancer prevention. Thiazolidinedione drugs like pioglitazone are clinically used for the treatment of diabetes and activate PPARδ as a primary target. P21/WAF1 is a cell cycle protein that is a cyclin dependent kinase inhibitor that reguylates cell cycle progression at the G1 phase; therefore its induction may be associated with cell cycle downregulation in precancerous cells experiencing increased proliferation. In our present study we examined the effects of pioglitazone on proliferation in human leukoplakia cells (MSK 1) and transformed lung (BEAS 2B) cells. We found that pioglitazone significantly inhibited cell proliferation in both cell lines in a dose dependent fashion at concentrations between 0 and 40 uM, as judged by MTT assays from 1-5 days. We found p21/WAF 1 induction by western blot within the first eight hours after the intitiation of treatment with pioglitazone, which were preceded by measureable increases in p21 induction on q PCR. In an analysis of an Affymetrix database of human head and neck tumors (41 tumors compared to 13 normal oral mucosa samples), we found significant dysregulation in several p21 activated kinases. We conclude the PPARδ activator, pioglitazone, can activate p21, which is associated with decreased proliferation in 2 aerodigestive preneoplastic cell lines. We also conclude that this gene may be a potential hypothesis driven biomarker in translational studies of pioglitazone as a chemoprevention agent for aerodigestive cancer.

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 601. doi:1538-7445.AM2012-601

The effect of indomethacin on paclitaxel sensitivity and apoptosis in oral squamous carcinoma cells: the role of nuclear factor-κB inhibition

OBJECTIVE

To investigate new strategies to intensify chemosensitivity in head and neck squamous cell carcinoma.

DESIGN

Oral squamous carcinoma cells were examined for nuclear factor-κB (NF-κB) activation and binding activity by paclitaxel, an agent currently used in head and neck cancer chemotherapy. Electromobility shift assays were used to assess the effect of indomethacin on NF-κB binding activity. Cell proliferation assays were used to study cell sensitivity to paclitaxel. To examine whether cytotoxicity could be increased by specifically inhibiting NF-κB, a dominant negative cell line, inhibitor kappa B-alpha (IκBα), was stably expressed in CA-9-22 cells.

RESULTS

Paclitaxel possessed the capacity to functionally activate NF-κB, as demonstrated by luciferase reporter gene assays and electromobility shift assay. Indomethacin was able to inhibit paclitaxel-mediated NF-κB activation and promote apoptosis of paclitaxel-treated cells at 24 hours. Indomethacin augmented the paclitaxel cell-killing effect. The dominant negative IκBα cell line exhibited increased chemosensitization to paclitaxel by 2- to 10-fold.

CONCLUSIONS

Paclitaxel has the capacity to activate NF-κB in oral squamous carcinoma cells. Indomethacin can reverse this activation to decrease cell proliferation and increase apoptosis. Treatment strategies that combine paclitaxel with indomethacin may have therapeutic benefits attributable to paclitaxel chemosensitization through NF-κB inhibition.