Small Intestinal Tumor Multiplicity Research Articles

Targeting IL-23 for the interception of obesity-associated colorectal cancer

Inflammation and obesity are two major factors that promote Colorectal cancer (CRC). Our recent data suggests that interleukin (IL)-23, is significantly elevated in CRC tumors and correlates with patient obesity, tumor grade and survival. Thus, we hypothesize that obesity and CRC may be linked via inflammation and IL-23 may be a potential target for intervention in high-risk patients. TCGA dataset and patient sera were evaluated for IL-23A levels. IL-23A [IL-23 p19−/−] knockout (KO) mice were crossed to Apcmin/+ mice and progeny were fed low-fat or high-fat diets. At termination intestines were evaluated for tumorigenesis. Tumors, serum, and fecal contents were analyzed for protein biomarkers, cytokines, and microbiome profile respectively. IL-23A levels are elevated in the sera of patients with obesity and colon tumors. Genetic ablation of IL-23A significantly suppressed colonic tumor multiplicity (76–96 %) and incidence (72–95 %) in male and female mice. Similarly, small-intestinal tumor multiplicity and size were also significantly reduced in IL-23A KO mice. IL-23A knockdown in Apcmin/+ mice fed high-fat diet, also resulted in significant suppression of colonic (50–58 %) and SI (41–48 %) tumor multiplicity. Cytokine profiling showed reduction in several circulating pro-inflammatory cytokines including loss of IL-23A. Biomarker analysis suggested reduced tumor cell proliferation and immune modulation with an increase in tumor-infiltrating CD4+ and CD8+ T-lymphocytes in the IL-23A KO mice compared to controls. Fecal microbiome analysis revealed potentially beneficial changes in the bacterial population profile. In summary, our data indicates a tumor promoting role for IL-23 in CRC including diet-induced obesity. With several IL-23 targeted therapies in clinical trials, there is a great potential for targeting this cytokine for CRC prevention and therapy.

Abstract LB225: Colon cancer preventive efficacy of licofelone and its analogue LFA-9 in PIRC rat model of FAP

Abstract Inflammation is a key hallmark of many cancers and potent target for chemoprevention. Experimental and clinical intervention studies indicate strong cancer preventive efficacy of cyclooxygenase (COX)-2 inhibitors. Their use for chemoprevention is limited due to increased cardiovascular (CV) toxicities. Selective COX-2 inhibition diverts arachidonic acid to the 5-lipoxygenase (5-LOX) pathway resulting in accumulation of prothrombotic leukotrienes while depleting antithrombotic prostaglandin (PG)I2, leading to increased risk of CV events. To overcome side effects, balanced dual inhibitors targeting COX-2/5-LOX or microsomal PGE synthase (mPGES)-1/5-LOX enzymes are being developed for chemoprevention. In this study, the clinically advanced dual COX-2/5-LOX inhibitor, licofelone, and its glycine analogue (LFA-9), the mPGES-1/5-LOX dual inhibitor, were evaluated for colon cancer preventive efficacy in the FAP relevant PIRC rat model. In preclinical dose range finding and preliminary toxicity studies in F344 rats, dietary administration of licofelone <500ppm and LFA9 <1,600ppm for 8 weeks showed no signs of toxicity based on by body weight gain, organs histopathology, blood cell counts, and serum chemistry. For efficacy evaluation, male and female PIRC rats were randomized by age (n≥15/group/gender). All rats had pre-intervention colonoscopies (8 weeks age) to determine baseline colonic polyps and were fed AIN-76A diets containing licofelone (250 ppm), LFA-9 (800ppm) or control until 32 (male) or 40 (female) weeks of age. Colonoscopies were repeated every 8 weeks for longitudinal monitoring of tumor development. At the end of the treatment period, rats were euthanized and intestines were evaluated for tumor multiplicity as an efficacy endpoint. Colonoscopy data suggested no significant difference in pretreatment colonic polyp multiplicity. However, there was a marked delay in colon tumor development in rats in the intervention group compared to control. Colonic tumor multiplicity at termination indicated that licofelone treated male rats developed 32% less tumors (21.87±1.23 (Mean±SEM); p<0.0001), while LFA-9 treated male rats had 31% less tumors (22.13±1.19; p<0.0001) compared to controls (32.25±1.37). There was no significant difference in tumor multiplicity between licofelone and LFA-9 treatment groups. In females, licofelone treatment led to 51% inhibition of colonic tumors (9.18±1.25; p<0.0002) while LFA-9 treatment led to 37% inhibition (11.89±0.86; p<0.002) compared to control (18.91±1.88). Although licofelone trended toward better inhibitory effect in females, this was not significantly different from the LFA-9 group. Colon tumor volume and small intestinal tumor multiplicity was notably inhibited in both licofelone and LFA-9 treated rats when compared to control. Our data suggest both licofelone and LFA-9 exhibit moderate and uniform chemopreventive efficacy against FAP-associated intestinal tumorigenesis in the PIRC rat model. (Supported by NCI HHSN HHSN261201500024I) Citation Format: Venkateshwar Madka, Nagendra S. Yarla, Gopal Pathuri, Yuting Zhang, Anh Bao, Nicole C. Stratton, Anil Singh, David L. McCormick, Altaf Mohammed, Shizuko Sei, Jennifer Fox, Chinthalapally V. Rao. Colon cancer preventive efficacy of licofelone and its analogue LFA-9 in PIRC rat model of FAP [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB225.

Abstract 5248: ED-71, an analogue of Vitamin D3, blocks the promotion but not the initiation of colorectal tumors in the Apc+/Min-FCCC mouse model

Abstract Results from several studies demonstrate an inverse relationship between circulating levels of Vitamin D and risk of colorectal cancer. Eldecalcitol (1α,25-dihydroxy-2β-(3-hydroxypropyloxy) Vitamin D3; ED-71) is a novel analog of calcitriol, the most active form of Vitamin D3. ED-71 is more potent in stimulating bone remodeling and has been approved in Japan for the treatment of osteoporosis. The goal of this study was to assess the ability of ED-71 to inhibit spontaneous colorectal adenomas in a unique strain of multiple intestinal neoplasia (Apc+/Min-FCCC) mice. Male mice (6 wks of age) were randomized to treatment groups based on colon tumor status (endoscopic confirmation as tumor-free or -bearing) and body weight (bw) and administered: vehicle (MCT), calcitriol (0.25 μg/kg bw), or ED-71 (0.05 or 0.1 μg/kg bw) by gavage. Mice were treated every other day and bws were recorded weekly. After 14 wks of treatment, the small intestines and colons were excised and examined for gross tumors. Colorectal tumors >3 mm in diameter were frozen for gene expression analyses. The remaining tissue was fixed in formalin and processed for histological review. The multiplicity of gross small intestinal tumors in animals treated with ED-71 (both doses) was comparable to that of vehicle-treated controls. In contrast, the multiplicity of small intestinal tumors was elevated 34.6% over that of controls in animals treated with calcitriol (Mean ± SEM: 28.4 ± 2.6 vs. 21.1 ± 2.8, respectively; P = 0.034). The ability of ED-71 to inhibit colon tumorigenesis was evaluated independently in mice with vs. without tumors at treatment initiation. In tumor-bearing mice, neither calcitriol nor ED-71 (both doses) had any significant effect on the multiplicity of colorectal tumors as compared to control mice. However in tumor-free mice, ED-71 (0.1 μg/kg bw) reduced the mean incidence of adenomas (> 4 crypts) by 47% (ED-71 - 45.5%, controls 92.3%; P = 0.02) and the multiplicity by 47.6% (Mean ± SEM: ED-71 - 1.1 ± 0.39, controls - 2.1 ± 0.72; P > 0.05). In contrast, the multiplicity of microadenomas (≤ 4 crypts) was increased in mice treated with ED-71 (0.1 μg/kg bw) as compared to controls (0.9 ± 0.22 vs. 0.5 ± 0.25 P = 0.06, respectively). These findings suggest that ED-71 is effective in preventing the transition of microadenomas to mature adenomas. The lack of an effect of ED-71 on colon tumor development in mice bearing tumors at baseline could be due in part to loss of the Vitamin D receptor in colon adenomas, as confirmed by real-time PCR. Insight into the mechanism by which ED-71 inhibits adenoma development is being gained from analyses of Vitamin D signaling and microRNA expression in treated colonic epithelial cells. These promising data provide support for future studies to determine the potential utility of ED-71 in preventing colorectal cancer in high-risk patients found to be tumor-free during surveillance endoscopy. (Supported by NCI HHSN261201200015I) Citation Format: Wen-Chi L. Chang, Harry S. Cooper, Esther Kaunga, Lisa Vanderveer, Jing Peng, Suen S. Chen, Margie L. Clapper. ED-71, an analogue of Vitamin D3, blocks the promotion but not the initiation of colorectal tumors in the Apc+/Min-FCCC mouse model. [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 5248.

High-Energy Particle-Induced Tumorigenesis Throughout the Gastrointestinal Tract

Epidemiological data reveals the gastrointestinal (GI) tract as one of the main sites for low-LET radiation-induced cancers. Importantly, the use of particle therapy is increasing, but cancer risk by high-LET particles is still poorly understood. This gap in our knowledge also remains a major limiting factor in planning long-term space missions. Therefore, assessing risks and identifying predisposing factors for carcinogenesis induced by particle radiation is crucial for both astronauts and cancer survivors. We have previously shown that exposure to relatively high doses of high-energy (56)Fe ions induced higher intestinal tumor frequency and grade in the small intestine of Apc(Min/+) mice than γ rays. However, due to the high number of spontaneous lesions (∼30) that develop in Apc(Min/+) animals, this Apc mutant model is not suitable to investigate effects of cumulative doses <1 Gy, which are relevant for risk assessment in astronauts and particle radiotherapy patients. However, Apc(1638N/+) mice develop a relatively small number of spontaneous lesions (∼3 per animal) in both small intestine and colon, and thus we propose a better model for studies on radiation-induced carcinogenesis. Here, we investigated model particle radiation increases tumor frequency and grade in the entire gastrointestinal tract (stomach and more distal intestine) after high- and low-radiation doses whether in the Apc(1638N/+). We have previously reported that an increase in small intestinal tumor multiplicity after exposure to γ rays was dependent on gender in Apc(1638N/+) mice, and here we investigated responses to particle radiation in the same model. Phenotypical and histopathological observations were accompanied by late changes in number and position of mitotic cells in intestinal crypts from animals exposed to different radiation types.

Chemopreventive efficacy of Targretin in rodent models of urinary bladder, colon/intestine, head and neck and mammary cancers

The chemopreventive efficacy of Targretin was evaluated in various rodent cancer models. In the rat model of 4-hydroxybutyl(butyl)nitrosamine (OH-BBN)-induced urinary bladder cancer, it was found that Targretin administered in the diet (beginning one week after the last OH-BBN treatment) for 5.5 months increased the number and size of urinary bladder cancers. In the azoxymethane (AOM)-induced model of colon carcinogenesis (in which rats develop minimally invasive colonic cancers), Targretin was ineffective as a chemopreventive agent, decreasing neither tumor incidence nor multiplicity. Treatment of Min mice with Targretin for 45 days similarly failed to decrease the multiplicity of small intestinal tumors. Similarly, no preventive efficacy was noted for Targretin when the incidence of tumors in the head and neck model (squamous cell tongue tumors) induced by 4-nitroquinoline 1-oxide (4-NQO) were examined. In contrast, use of even a suboptimal dose of Targretin (40ppm) in a sensitive breast cancer model [methylnitrosourea (MNU)-induced ER+ mammary cancers] reduced cancer multiplicity by 60%. Finally, based on the hypothesis that Targretin may decrease the expression of COX‑2, the effects of Targretin and COX inhibitors were compared in these models. There was minimal overlap of efficacy. That is, models which were relatively susceptible to NSAIDs or COX-2 inhibitors tended not to be sensitive to Targretin and vice versa.

Inhibitory effects of calcium against intestinal cancer in human colon cancer cells andApcMin/+mice

The aim of the study was to investigate the inhibitory effects of calcium against intestinal cancer in vitro and in vivo. We first investigated the effects of calcium treatment in HCT116 and HT29 human colon cancer cells. At the concentration range of 0.8-2.4 mM, calcium significantly inhibited cell growth (by 9-29%), attachment (by 12-26%), invasion (by 15-31%), and migration (by 19-61%). An immunofluorescence microscope analysis showed that the treatment with calcium (1.6 mM) for 24 h increased plasma membrane β-catenin but decreased nuclear β-catenin levels in HT29 cells. We then investigated the effect of dietary calcium on intestinal tumorigenesis in ApcMin/+ mice. Mice received dietary treatment starting at 6 weeks of age for the consecutive 8 weeks. The basal control diet contained high-fat (20% mixed lipids by weight) and low-calcium (1.4 mg/g diet) to mimic the average Western diet, while the treatment diet contained an enriched level of calcium (5.2 mg calcium/g diet). The dietary calcium treatment decreased the total number of small intestinal tumors (by 31.4%; P < 0.05). The largest decrease was in tumors which were ≥ 2 mm in diameter, showing a 75.6% inhibition in the small intestinal tumor multiplicity (P < 0.001). Immunohistochemical analysis showed significantly reduced nuclear staining of β-catenin (expressed as nuclear positivity), but increased plasma membrane staining of β-catenin, in the adenomas from the calcium-treated groups in comparison to those from the control group (P < 0.001). These results demonstrate intestinal cancer inhibitory effects of calcium both in human colon cancer cells and ApcMin/+ mice. The decreased β-catenin nuclear localization caused by the calcium treatment may contribute to the inhibitory action.

Effect of Dietary Corn Bran and Autohydrolyzed Lignin on 3,2′-Dimethyl-4-aminobiphenyl-Induced Intestinal Carcinogenesis in Male F344 Rats&lt;xref ref-type="fn" rid="FN2"&gt;2&lt;/xref&gt;&lt;xref ref-type="fn" rid="FN3"&gt;3&lt;/xref&gt;

The effect of dietary corn bran and autohydrolyzed lignin on 3,2'-dimethyl-4-aminobiphenyl (DMAB)-induced intestinal carcinogenesis was studied in male inbred F344 rats. Groups of weanling rats were fed semipurified diets containing 15% corn bran or 7.5% lignin or a semipurified diet without these fibers (control diet). At 7 weeks of age, all animals, except vehicle-treated controls, were given sc injections of 50 mg DMAB/kg body weight/week for 20 weeks. All animals were autopsied 20 weeks after the last injection of DMAB. The incidence of colon tumors (percentage of animals with tumors) and colon tumor multiplicity (tumors/animal) were increased in rats fed the corn bran diet as compared to the tumor incidence and multiplicity in rats fed the control diet. The incidence of small intestinal tumors was slightly lower in rats fed the corn bran diet as compared to the incidence in rats fed the control diet. The concentrations (mg/g dry feces) of fecal deoxycholic acid and total bile acids and the daily output of fecal deoxycholic acid, lithocholic acid, hyodeoxycholic acid, and total bile acids were increased in rats fed the corn bran diet as compared to the concentrations and daily output in rats fed the control diet. The incidence and multiplicity of small intestinal tumors as well as the number of colon adenocarcinomas per tumor-bearing animal were lower in animals fed the lignin diet than in those fed the control diet. Lignin had no effect on the concentrations of fecal bile acids, but the daily output of total bile acids was increased in animals fed the lignin diet as compared to the daily output in rats fed the control diet. This study thus indicates that the protection against colon cancer depends on the type of fiber.