PDF - 982K, Supplementary figure 2. Common gene network for NO-naproxen and naproxen treated rat liver.
PDF file - 40K, Effect of Erlotinib (6 mg/kg BW/day) on Time of Appearance of Methylnitrosourea- Induced Mammary Cancers in Female Sprague-Dawley Rats.
PDF - 1022K, Supplementary figure 1. Common gene network for NO-naproxen and naproxen treated rat liver.
PDF - 73K, Supplementary Table S1. Effects of Various NSAIDs on Urinary 11-α-hydroxy-9, 15-dioxo-2, 3, 4, 5-tetranor-prostane-1, 20-dioic acid (PGE-M) levels.
BACKGROUND: There are few effective treatments specifically aimed at basal bladder cancer. OBJECTIVE: Female F344 rats administered N-butyl-N-(4-hydroxybutyl)-nitrosamine (OH-BBN) develop large invasive bladder cancers. We determined the efficacy of daily vs weekly dosing of EGFR inhibitors, determined the efficacy of naproxen combined with an EGFR inhibitor, and performed RNA analysis of bladder tumors treated for 5 days with EGFR inhibitors or NO-naproxen to identify pharmacodynamic biomarkers. METHODS: Erlotinib (6 mg/Kg BW daily or 21 or 42 mg/Kg BW weekly), lapatinib (25 or 75 mg/Kg BW daily or 263 or 525 mg/Kg BW weekly) and/or naproxen (30 mg/Kg BW daily) were administered to OH-BBN-treated rats beginning 2–12 weeks post OH-BBN. Rats were sacrificed 28 weeks after the final OH-BBN treatment to determine the effects of the EGFR inhibitors + naproxen on bladder weights and tumor development. In a separate study, rats were treated with OH-BBN. When palpable tumors developed, rats were treated with erlotinib, lapatinib, gefitinib, or the NSAID NO-naproxen for 5 days. RNA analysis was performed on the tumors. RESULTS: Daily or weekly dosing of erlotinib or lapatinib and daily dosing of naproxen reduced large tumor formation up to 70%, while combining daily lapatinib and naproxen reduced tumors 100%. RNA Analysis: All EGFR inhibitors strongly reduced cell proliferation and chromosome replication pathways, while NO-naproxen altered the G protein receptor, oxygen homeostasis and immune function pathways. CONCLUSIONS: While daily and weekly dosing with EGFR inhibitors and naproxen were effective, combining lapatinib and naproxen yielded no tumors. This might encourage its clinical use in an adjuvant setting with superficial basal tumors, and perhaps even in a more advanced setting. Furthermore, RNA analysis identified specific pathways that might be potential pharmacodynamic biomarkers in clinical trials.
AbstractDaily dosing of either NSAIDs or EGFR inhibitors has been shown to prevent bladder cancer development in a N-butyl-(4-hydroxybutyl)nitrosamine (OH-BBN)-induced rat model. However, these inhibitors cause gastrointestinal ulceration and acneiform rash, respectively, limiting their continuous use in a clinical prevention setting. We studied chemopreventive efficacy of pulsatile dosing of EGFR inhibitor erlotinib (42 mg/kg BW, once/week) combined with intermittent or continuous low doses of the NSAID naproxen (30 mg/kg BW/day, 3 weeks on/off or 128 ppm daily in diet) in the OH-BBN induced rat bladder cancer model. The interventions were started either at 1 or 4 weeks (early intervention) or 3 months (delayed intervention) after the last OH-BBN treatment, by which time the rats had developed microscopic bladder lesions. All combination regimens tested as early versus late intervention led to the reduction of the average bladder tumor weights (54%–82%; P < 0.01 to P < 0.0001), a decrease in tumor multiplicity (65%–85%; P < 0.01 to P < 0.0001), and a decrease in the number of rats with large palpable tumors (>200 mg; 83%–90%; P < 0.01 to P < 0.0001). Levels of signal transduction markers, Ki-67, cyclin D1, IL1β, pSTAT3, and pERK, were significantly (P < 0.05 to P < 0.001) reduced in the treated tumors, demonstrating their potential utility as predictive markers for efficacy. These findings demonstrate that significant chemopreventive efficacy could be achieved with alternative intervention regimens designed to reduce the toxicity of agents, and that starting erlotinib and/or naproxen treatments at the time microscopic tumors were present still conferred the efficacy.
AbstractIn both estrogen receptor/progesterone receptor–positive (ER+/PR+) human breast cancer and in ER+/PR+ cancers in the methylnitrosourea (MNU)-induced rat model, short-term modulation of proliferation in early cancers predicts preventive/therapeutic efficacy. We determined the effects of known effective/ineffective chemopreventive agents on proliferative index (PI) in both rat mammary epithelium and small cancers. Female Sprague-Dawley rats were treated with MNU at 50 days of age. Five days later, the rats were treated with the individual compounds for a period of 14 days. At that time, normal mammary tissue from the inguinal gland area was surgically removed. After removal, the rats remained on the agents for an additional 5 months. This cancer prevention study confirmed our prior results of striking efficacy with tamoxifen, vorozole, Targretin, and gefitinib, and no efficacy with metformin, naproxen, and Lipitor. Employing a separate group of rats, the effects of short-term (7 days) drug exposure on small palpable cancers were examined. The PI in both small mammary cancers and in normal epithelium from control rats was >12%. In agreement with the cancer multiplicity data, tamoxifen, vorozole, gefitinib, and Targretin all strongly inhibited proliferation (>65%; P < 0.025) in the normal mammary epithelium. The ineffective agents metformin, naproxen, and Lipitor minimally affected PI. In the small cancers, tamoxifen, vorozole, and Targretin all reduced the PI, while metformin and Lipitor failed to do so. Thus, short-term changes in the PI in either normal mammary epithelium or small cancers correlated with long-term preventive efficacy in the MNU-induced rat model.
Signal transducer and activator of transcription 3 (STAT3) plays a key role in the transformation of normal cells to cancerous cells. Although inhibitors of STAT3 have been shown to suppress the growth of multiple cancer types in vitro and in vivo, such agents are of particular interest for the prevention of breast cancer, which affects over 200,000 women and claims more than 40,000 lives in the United States each year. In the present study, we employed the MMTV/Neu transgenic mouse model, which develops estrogen receptor (ER)‑negative, Neu‑overexpressing tumors, and the Sprague‑Dawley (SD) rat model, which develops ER‑positive tumors upon exposure to the carcinogen 7,12‑dimethylbenz[a]anthracene (DMBA), to test the efficacy of the STAT3 inhibitor GLG‑302 in the prevention of mammary cancer. Orally administered GLG‑302 and its trizma salt derivative reduced mammary cancer incidence, multiplicity, and tumor weights in female MMTV/Neu mice, and GLG‑302 reduced tumor multiplicity and weights in female DMBA‑treated rats. Consistent with the mechanism of action of STAT3 inhibitors, the reductions in mammary tumors were correlated with decreases in STAT3 phosphorylation and cell proliferation. These data suggest that GLG‑302 is a novel agent with potential for prevention of mammary cancer and support the further development of STAT3 inhibitors for this cause.
The AKT inhibitor employed in this article was identified as MK 2206 (8‑[4‑(1‑aminocyclobutyl) phenyl]‑9‑phenyl‑1,2,4‑ triazolo[3,4‑f][1,6]naphthyridin‑3(2H)‑one hydrochloride (1:2). However, another AKT inhibitor was actually used, which is typically identified as Akt I‑1,2 (HC,I. IPA (2‑[4‑(3‑phenylquinoxalin‑2‑yl)phenyl]propan‑2‑amine hydrochloride isopropanol (1:1:1). Therefore, all references to MK 2206 in the paper should have been made to Akt I‑1.2. Based on the experience of the present authors with a range of targeted inhibitors, it is expected that both inhibitors would have given rise to similar results; therefore, the results obtained in the paper are not likely to have been greatly affected as a consequence of the use of the alternative inhibitor. The authors regret that this error was not identified sooner, prior to the publication of the article, and regret any inconvenience that has been caused. [the original article was published in Oncology Reports 40: 1545‑1553, 2018; DOI: 110.3892/or.2018.6313]
Metformin is a biguanide employed in treating type II diabetes. Its potential efficacy for treating cancer has been demonstrated epidemiologically (lower cancer incidence in metformin users compared with users of sulfonylureas or insulin) and mechanistically, primarily in cell culture. Metformin decreases the levels of insulin-like growth factor 1 and secondarily inhibits the mammalian target of rapamycin pathway to exhibit anticancer effects. The current study examined its cancer preventive efficacy in multiple standard in situ arising cancer models. Metformin was administered orally by gavage or in the diet, at human equivalent doses, in numerous cancer models. In the hydroxybutyl(butyl)nitrosamine-induced model of invasive urinary bladder cancer, metformin (50 or 150 mg/kg body weight/day, intragastric) was ineffective despite high urinary concentrations of metformin. Metformin (250 or 500 ppm in diet) failed to decrease the incidence or invasiveness of squamous cell cancer of the tongue in a 4-nitroquinoline-1-(4NQO)-induced model. Finally, in the Min mouse model of gastrointestinal cancer, metformin (400 or 1,200 ppm in diet) was ineffective. Notably, a slight increase in intestinal tumor multiplicity was observed at the higher dose. Therefore, metformin lacked efficacy in multiple standard cancer models in non-diabetic rodents. This lack of efficacy may discourage any large phase clinical cancer trials in non-diabetic individuals in the absence of clear phase-II studies.
Abstract The preventive efficacy of the triterpenoid 5MeCDDO was tested in two models of mammary cancer, the Min model of intestinal cancer, and a chemically induced model of head and neck cancer. In one model of mammary cancer, female Sprague-Dawley rats were administered MNU at 50 days of age, and 5MeCDDO (27 ppm) was administered in the diet beginning 5 days later for the duration of the study; 5MeCDDO was ineffective. In contrast, in a model examining initiation of mammary cancers by the procarcinogen dimethyl-benzanthracene, 5, 6-benzoflavone (500 ppm, an Ah receptor agonist) or 5MeCDDO (27 or 2.7 ppm) decreased tumor multiplicity by 90%, 80%, and 50%, respectively. This anti-initiating effect which is presumably mediated by altered metabolic activation parallels our observation that 5MeCDDO induced proteins of various antioxidant response element (ARE)-related phase II drug-metabolizing enzymes [e.g., GST Pi, AKR 7A3 (aflatoxicol), epoxide hydrolase, and quinone reductase] in the liver. 5MeCDDO tested in the 4-nitroquinoline-l-oxide (4-NQO) head and neck cancer model failed to decrease tumor incidence or invasiveness. In the Min mouse model of intestinal cancer, a high dose of 5MeCDDO (80 ppm) was weakly effective in reducing adenoma multiplicity [∼30% (P < 0.05)]; however, a lower dose was totally ineffective. These findings question whether measuring increased levels of certain ARE-related genes (e.g., quinone reductase, GST Pi), indicating decreased carcinogen activation are sufficient to imply general chemopreventive efficacy of a given agent or mixture. Cancer Prev Res; 9(7); 616–23. ©2016 AACR.
Abstract The COX inhibitors (NSAID/Coxibs) are a major focus for the chemoprevention of cancer. The COX-2–specific inhibitors have progressed to clinical trials and have shown preventive efficacy in colon and skin cancers. However, they have significant adverse cardiovascular effects. Certain NSAIDs (e.g., naproxen) have a good cardiac profile, but can cause gastric toxicity. The present study examined protocols to reduce this toxicity of naproxen. Female Fischer-344 rats were treated weekly with the urinary bladder–specific carcinogen hydroxybutyl(butyl)nitrosamine (OH-BBN) for 8 weeks. Rats were dosed daily with NPX (40 mg/kg body weight/day, gavage) or with the proton pump inhibitor omeprazole (4.0 mg/kg body weight/day) either singly or in combination beginning 2 weeks after the final OH-BBN. OH-BBN–treated rats, 96% developed urinary bladder cancers. While omeprazole alone was ineffective (97% cancers), naproxen alone or combined with omeprazole-prevented cancers, yielding 27 and 35% cancers, respectively. In a separate study, OH-BBN–treated rats were administered naproxen: (A) daily, (B) 1 week daily naproxen/1week vehicle, (C) 3 weeks daily naproxen/3 week vehicle, or (D) daily vehicle beginning 2 weeks after last OH-BBN treatment. In the intermittent dosing study, protocol A, B, C, and D resulted in palpable cancers in 27%, 22%, 19%, and 96% of rats (P < 0.01). Short-term naproxen treatment increased apoptosis, but did not alter proliferation in the urinary bladder cancers. Two different protocols that should decrease the gastric toxicity of NSAIDs in humans did not alter chemopreventive efficacy. This should encourage the use of NSAIDs (e.g., naproxen) in clinical prevention trials. Cancer Prev Res; 8(4); 296–302. ©2015 AACR.
Epidemiologic studies have shown that diabetics receiving the biguanide metformin, as compared with sulfonylureas or insulin, have a lower incidence of breast cancer. Metformin increases levels of activated AMPK (AMP-activated protein kinase) and decreases circulating IGF-1; encouraging its potential use in both cancer prevention and therapeutic settings. In anticipation of clinical trials in nondiabetic women, the efficacy of metformin in nondiabetic rat and mouse mammary cancer models was evaluated. Metformin was administered by gavage or in the diet, at a human equivalent dose, in standard mammary cancer models: (i) methylnitrosourea (MNU)-induced estrogen receptor–positive (ER+) mammary cancers in rats, and (ii) MMTV-Neu/p53KO ER− (estrogen receptor–negative) mammary cancers in mice. In the MNU rat model, metformin dosing (150 or 50 mg/kg BW/d, by gavage) was ineffective in decreasing mammary cancer multiplicity, latency, or weight. Pharmacokinetic studies of metformin (150 mg/kg BW/d, by gavage) yielded plasma levels (Cmax and AUC) higher than humans taking 1.5 g/d. In rats bearing small palpable mammary cancers, short-term metformin (150 mg/kg BW/d) treatment increased levels of phospho-AMPK and phospho-p53 (Ser20), but failed to reduce Ki67 labeling or expression of proliferation-related genes. In the mouse model, dietary metformin (1,500 mg/kg diet) did not alter final cancer incidence, multiplicity, or weight. Metformin did not prevent mammary carcinogenesis in two mammary cancer models, raising questions about metformin efficacy in breast cancer in nondiabetic populations. Cancer Prev Res; 8(3); 231–9. ©2015 AACR.
Background: Osteopontin (OPN) is a matricellular glycoprotein that is markedly expressed in cutaneous squamous cell carcinomas (cSCCs) and in actinic keratoses implicating its role in photocarcinogenesis.Objective: To determine whether OPN facilitates the development of cSCC and its function.Methods: cSCCs development was compared between wild-type (WT) and OPN-null mice subjected to UVB irradiation for 43 weeks. UVB-induced OPN expression was determined by Western blot, immunoprecipitation, ELISA, and semi-quantitative RT-PCR. Epidermal layer and TUNEL analyses assessed if OPN mediates UVB-induced epidermal hyperplasia or suppresses UVB-induced apoptosis of basal keratinocytes, respectively. In vitro experiments determined whether OPN enhances cell survival of UVB-induced apoptosis and its potential mechanisms. Immunohistochemical analyses of epidermis assessed the expression of CD44 and focal adhesion kinase (FAK), molecules that mediate OPN survival function.Results: Compared to female WT mice, OPN-null mice did not develop cSCCs. UVB irradiation stimulated OPN protein expression in the dorsal skin by 11 h and remains high at 24-48 h. OPN did not mediate UVB-induced epidermal hyperplasia; instead, it protected basal keratinocytes from undergoing apoptosis upon UVB exposure. Likewise, the addition of OPN suppressed UVB-induced OPN-null cSCC cell apoptosis, the activation of caspase-9 activity, and increased phosphorylation of FAK at Y397. Furthermore, the expression of CD44 and FAK in WT mice epidermis was greater than that of OPN-null mice prior to and during early acute UVB exposure.Conclusion: These data support the hypothesis that chronic UVB-induced OPN expression protects the survival of initiated basal keratinocytes and, consequently, facilitates cSCC develop. (C) 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
Abstract Urinary bladder cancer prevention studies were performed with the nonsteroidal anti-inflammatory drugs (NSAID) naproxen (a standard NSAID with a good cardiovascular profile), sulindac, and their nitric oxide (NO) derivatives. In addition, the effects of the ornithine decarboxylase inhibitor, difluoromethylornithine (DFMO), alone or combined with a suboptimal dose of naproxen or sulindac was examined. Agents were evaluated at their human equivalent doses (HED), as well as at lower doses. In the hydroxybutyl(butyl)nitrosamine (OH-BBN) model of urinary bladder cancer, naproxen (400 or 75 ppm) and sulindac (400 ppm) reduced the incidence of large bladder cancers by 82%, 68%, and 44%, respectively, when the agents were initially given 3 months after the final dose of the carcinogen; microscopic cancers already existed. NO-naproxen was highly effective, whereas NO-sulindac was inactive. To further compare naproxen and NO-naproxen, we examined their effects on gene expression in rat livers following a 7-day exposure. Limited, but similar, gene expression changes in the liver were induced by both agents, implying that the primary effects of both are mediated by the parent NSAID. When agents were initiated 2 weeks after the last administration of OH-BBN, DFMO at 1,000 ppm had limited activity, a low dose of naproxen (75 ppm) and sulindac (150 ppm) were highly and marginally effective. Combining DFMO with suboptimal doses of naproxen had minimal effects, whereas the combination of DMFO and sulindac was more active than either agent alone. Thus, naproxen and NO-naproxen were highly effective, whereas sulindac was moderately effective in the OH-BBN model at their HEDs. Cancer Prev Res; 7(2); 246–54. ©2013 AACR.
Abstract EGF receptor (EGFR) inhibitors are used in the therapy of lung and pancreatic cancers and effectively prevent cancers in multiple animal models. Although daily dosing with erlotinib is effective, weekly dosing may reduce toxicity and have advantages, particularly for prevention. We tested alternative dosing regimens for preventive/therapeutic efficacy in a rat mammary cancer model. For prevention, erlotinib was administered by gavage beginning 5 days after methylnitrosourea (MNU). For therapy and biomarker studies, rats with palpable mammary cancers were treated for six weeks or for six days, respectively. Experiment A, erlotinib (6 mg/kg body weight/day, intragastric): daily (7 times/week); one day on/one day off; and two days on/two days off. All regimens decreased tumor incidence, increased tumor latency, and decreased cancer multiplicity versus controls (P < 0.01). However, intermittent dosing was less effective than daily dosing (P < 0.05). Experiment B, erlotinib (6 mg/kg body weight/day) daily or two days on/two days off or one time per week at 42 mg/kg body weight. All regimens reduced cancer incidence and multiplicity versus controls (P < 0.01). Interestingly, daily and weekly dosing were equally effective (P > 0.5). Experiment C, erlotinib administered at 42 or 21 mg/kg body weight 1 time per week, decreased tumor incidence and multiplicity (P < 0.01). Erlotinib had a serum half-life of ≤8 hours and weekly treatment yielded effective serum levels for ≤48 hours. Daily or weekly treatment of cancer bearing rats reduced mammary tumor size 25% to 35%, whereas control cancers increased >250%. Levels of phosphorylated extracellular signal-regulated kinase (ERK) were strongly decreased in rats treated daily/weekly with erlotinib. Thus, altering the dose of erlotinib retained most of its preventive and therapeutic efficacy, and based on prior clinical studies, is likely to reduce its toxicity. Cancer Prev Res; 6(5); 448–54. ©2013 AACR.
The matricellular protein osteopontin (OPN), expressed in various cancer types and elevated in the blood of cancer patients, is thought to have different functions when derived from host versus cancer cells. To assess the effect of host‐derived OPN on growth of cancers of epithelial origin, we established a line of cutaneous squamous cell carcinoma (SCC) cells, named ONSC, which lacks the OPN gene and develops SCC in syngeneic wild‐type (WT) and OPN‐null mice. At 8 and/or 10 week after subcutaneous injection of ONSC cells in mice, however, there was a lower tumor incidence in WT mice, suggesting that host‐derived OPN is associated with suppression of early growth of extrinsic cancer cells. Histological, immunohistochemical, biochemical and hematological analyses were performed on the tumor microenvironment and blood from tumor‐bearing mice during the first week after implantation. Host‐derived OPN suppression of extrinsic ONSC cell progression is likely mediated through elicitation of an early innate inflammatory response, through its function as a chemoattractant and/or by enhancing survival of inflammatory cells. Further, consistent with a previous report, the serum levels of host‐derived OPN, which are elevated during the early phase of tumor growth in mice implanted with ONSC, appear to reflect an anti‐tumor progression effect.