Carcinogenesis In Mice Research Articles

Abstract 6516: Comparison study between a ketogenic diet and a high-fat diet on pancreatic cancer incidence in mice

Abstract Pancreatic Ductal Adenocarcinoma (PDAC) remains among the most lethal cancers. PDAC can take up to 15-20 years to develop from the occurrence of the first initiating mutational event, which opens the opportunity for intervention and prevention strategies. In particular, nutritional interventions could provide an avenue to prevent or slow down pancreatic carcinogenesis, since certain diets such as high-fat diets (HFD) have shown to promote it. On the other hand, ketogenic diets (KD), characterized by a high fat and very low carbohydrate content, have gained attention for their anti-tumor and anti-inflammatory potential. However, the role of a KD in the onset and progression of PDAC is still unknown. In this project, we investigated the impact of both a HFD and a KD on late-stage pancreatic carcinogenesis. For this purpose, we used an animal model of pancreatic cancer carrying a pancreas-specific oncogenic KRASG12D mutation [LSL-KRASG12D; P48+/Cre; (KC mice)]. On average, KC mice develop PDAC at 12-15 months of age, so they are a valuable tool to study late-stage carcinogenesis. We hypothesized that a HFD would accelerate PDAC progression while a KD would slow it down. To test our hypothesis, 6 months-old male and female KC mice (n=18/group) were randomized and fed, either a control diet (CD), a HFD, or a KD for 6 months and then euthanized at 12-months of age to evaluate pancreatic cancer incidence and progression. At 12-months of age, HFD-fed mice had significantly higher body weight compared to the other two groups. Moreover, KD-fed mice had significantly higher levels of blood ketone bodies, with lower levels of glucose and serum insulin levels, when compared to KC mice fed a HFD. However, after 6 months on the diets, no significant differences in pancreas weight nor in PDAC incidence were observed across all diet groups. Of note, male KC mice experienced double the PDAC incidence rates (55%) than female KC mice (27%), irrespectively of the group. In addition, no significant differences among the groups were observed in RAS/RAF/ERK and PI3K/AKT/mTOR pathways, known to be associated with cancer proliferation. In summary, despite the improvement in insulin and increases in ketone bodies, consumption of a strict KD failed to improve late-stage pancreatic carcinogenesis in mice. Citation Format: Tarek Bacha, Natalia Cortez Penso, Maria Rodriguez, Brian Hong, Gerardo Mackenzie. Comparison study between a ketogenic diet and a high-fat diet on pancreatic cancer incidence in mice. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6516.

The participation of tumor residing pericytes in oral squamous cell carcinoma

Pericytes are perivascular cells related to vessel structure and angiogenesis that can interact with neoplastic cells, interfering with cancer progression and outcomes. This study focused on the characterization of pericytes in oral squamous cell carcinoma (OSCC) using clinical samples and a transgenic mouse model of oral carcinogenesis. Nestin-/NG2+ (type-1) and nestin+/NG2+ (type-2) pericytes were analyzed by direct fluorescence after induction of oral carcinogenesis (4-nitroquinoline-1-oxide). Gene expression of neuron glial antigen-2 (NG2), platelet-derived growth factor receptor beta (PDGFR-β), and cluster of differentiation 31 (CD31) was examined in human OSCC tissues. The protein expression of von Willebrand factor and NG2 was assessed in oral leukoplakia (i.e., oral potentially malignant disorders) and OSCC samples. Additionally, clinicopathological aspects and survival data were correlated and validated by bioinformatics using The Cancer Genome Atlas (TCGA). Induction of carcinogenesis in mice produced an increase in both NG2+ pericyte subsets. In human OSCC, advanced-stage tumors showed a significant reduction in CD31 mRNA and von Willebrand factor-positive vessels. Low PDGFR-β expression was related to a shorter disease-free survival time, while NG2 mRNA overexpression was associated with a reduction in overall survival, consistent with the TCGA data. Herein, oral carcinogenesis resulted in an increase in NG2+ pericytes, which negatively affected survival outcomes.

Abstract 5266: Metabolic rewiring and epigenetic reprogramming by the environmental carcinogen benzo[a]pyrene in a two-stage skin carcinogenesis mouse model and cancer interception by triterpenoid ursolic acid

Abstract Nonmelanoma skin cancer (NMSC) is the most common skin cancer burden on the U.S. population. Environmental exposure to chemical carcinogens is one of the major causes of NMSC initiation, promotion, and progression. Ursolic acid (UA) is a naturally abundant pentacyclic triterpenoid showing anticancer potentials against diverse cancers. In the current study, we developed a two-stage skin carcinogenesis model in SKH1 hairless mice by administering cancer-initiating agent benzo[a]pyrene (B[a]P) and promoting agent 12-O-tetra-decanoylphorbol-13-acetate to study the epigenetic, transcriptomic, and metabolic changes at different stages (5, 20, and 26 weeks) during the development of NMSC, and investigated how UA regulates B[a]P-mediated alterations for NMSC interception. We found that UA protects against B[a]P-induced tumorigenesis at different phases of NMSC. Epigenetic CpG methyl-seq showed UA abrogated B[a]P-mediated alterations in differentially methylated regions (DMRs) profiles. Transcriptomic RNA-seq data exhibited UA reversed the differentially expressed genes (DEGs) of several inflammatory genes, such as chemokine ligand 8 (Ccl8) and interleukin 17F (Il17f), and epigenetic genes, such as DNA-methyltransferase 3-like (Dnmt3l) and protein-l-isoaspartate O-methyltransferase domain-containing protein 1 (Pcmtd1) during different stages of NMSC. Association study between DEGs and DMRs showed that B[a]P promoted transcription of kallikrein-related peptidase 13 (Klk13) by promoter demethylation, while UA suppressed Klk13 expression through hypermethylation in the promoter during the initiation stage, indicating the early intervention of UA. Ingenuity pathway analysis further showed significant upregulation of macrophage-stimulating protein-recepteur d'origine nantais (MSP-RON) signaling pathway by B[a]P during the initiation stage while suppressed by UA treatment. The metabolomic study revealed UA modulated cancer-associated changes in metabolisms, including the TCA cycle and pyruvate metabolism/metabolites during the promotion phase, indicating UA plays a critical role in regulating B[a]P-regulated metabolic changes and intercepting NMSC progression. In summary, UA protects against the environmental carcinogen B[a]P-driven epigenetic, transcriptomic, and metabolic changes during the initiation, promotion, and progression of NMSC, potentially contributing to the anticancer effects of UA. (Supported by NIH R01 CA200129 to A.N.K) Citation Format: Md. Shahid Sarwar, Christina N. Ramirez, Hsiao-Chen Dina Kuo, Pochung Chou, Renyi Wu, Davit Sargsyan, Ahmad Shannar, Rebecca Mary Peter, Ran Yin, Yujue Wang, Xiaoyang Su, Ah-Ng Kong. Metabolic rewiring and epigenetic reprogramming by the environmental carcinogen benzo[a]pyrene in a two-stage skin carcinogenesis mouse model and cancer interception by triterpenoid ursolic acid. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5266.

MP69-01 ESTABLISHMENT OF A NOVEL ANIMAL MODEL IN CARCINOGENESIS OF UPPER TRACT UROTHELIAL CARCINOMA AND ITS GENE PROFILE

You have accessJournal of UrologyCME1 Apr 2023MP69-01 ESTABLISHMENT OF A NOVEL ANIMAL MODEL IN CARCINOGENESIS OF UPPER TRACT UROTHELIAL CARCINOMA AND ITS GENE PROFILE Akinaru Yamamoto, Atsunari Kawashima, Kentaro Jingushi, Yuichi Motoyama, Satoshi Nojima, Sassi Nesrine, Yohei Okuda, Toshiki Oka, Toshihiro Uemura, Gaku Yamamichi, Eisuke Tomiyama, Kosuke Nakano, Makoto Matsushita, Yu Ishizuya, Yoshiyuki Yamamoto, Taigo Kato, Koji Hatano, Tsujikawa Kazutake, and Norio Nonomura Akinaru YamamotoAkinaru Yamamoto More articles by this author , Atsunari KawashimaAtsunari Kawashima More articles by this author , Kentaro JingushiKentaro Jingushi More articles by this author , Yuichi MotoyamaYuichi Motoyama More articles by this author , Satoshi NojimaSatoshi Nojima More articles by this author , Sassi NesrineSassi Nesrine More articles by this author , Yohei OkudaYohei Okuda More articles by this author , Toshiki OkaToshiki Oka More articles by this author , Toshihiro UemuraToshihiro Uemura More articles by this author , Gaku YamamichiGaku Yamamichi More articles by this author , Eisuke TomiyamaEisuke Tomiyama More articles by this author , Kosuke NakanoKosuke Nakano More articles by this author , Makoto MatsushitaMakoto Matsushita More articles by this author , Yu IshizuyaYu Ishizuya More articles by this author , Yoshiyuki YamamotoYoshiyuki Yamamoto More articles by this author , Taigo KatoTaigo Kato More articles by this author , Koji HatanoKoji Hatano More articles by this author , Tsujikawa KazutakeTsujikawa Kazutake More articles by this author , and Norio NonomuraNorio Nonomura More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003332.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Upper urinary tract (UT) and bladder are known to differ from the embryology stage. There have been numerous reports of mouse models of bladder carcinogenesis, but there are few reports of mouse models of upper tract urothelial carcinogenesis. The aim of this study is to establish a novel mouse model of upper tract urothelial carcinogenesis. METHODS: We used two strains including C57/BL6 of male and female mice. We fed 0.05% N-butyl-N-(4-hydro-oxybutyl) nitorosamine (BBN) from 6 weeks old to the harvest day. The harvested organs were diagnosed by two different pathologists with histopathological evaluation using Hematoxylin and Eosin staining. Both sides of UT from mouse drinking BBN were subjected to whole transcriptome sequencing (WTS). In human samples, 74 upper tract urothelial carcinoma (UTUC) tissues and 73 adjacent normal (AN) tissues also subjected to WTS from 74 UTUC patients. RESULTS: Female mice of certain strain showed early weight loss compared to the others. They showed high incidence of UTUC with less incidence of bladder cancer (Figure 1), while the others rarely had UTUC. The total incidence of UTUC in this mouse strain was 83.3%, with the earliest UTUC observed at 8 weeks after the start of BBN drinking. The incidence of bilateral UTUC was 22.2%, and these individuals showed weight loss relatively early after the start of BBN drinking. The cancerous side of UT expressed a basal type of mRNA expression profile, with increased expression of Cd44, Cdh3, and Krt14, similar to previous reports of bladder carcinogenesis mouse model (Figure 2). We detected 593 differential expressed genes between cancerous side and non-cancerous side of UT in this mouse model, which could also classify human UTUC and AN samples. In pathway enrichment analysis of these genes, several pathways associated with DNA replication were commonly upregulated in cancer tissues between mouse and human samples. CONCLUSIONS: We have established the novel animal model developing UTUC with high probability. This model could reflect the human UTUC. Source of Funding: This work was supported by a KAKENHI grant (21K20968, 22K09523) © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e963 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Akinaru Yamamoto More articles by this author Atsunari Kawashima More articles by this author Kentaro Jingushi More articles by this author Yuichi Motoyama More articles by this author Satoshi Nojima More articles by this author Sassi Nesrine More articles by this author Yohei Okuda More articles by this author Toshiki Oka More articles by this author Toshihiro Uemura More articles by this author Gaku Yamamichi More articles by this author Eisuke Tomiyama More articles by this author Kosuke Nakano More articles by this author Makoto Matsushita More articles by this author Yu Ishizuya More articles by this author Yoshiyuki Yamamoto More articles by this author Taigo Kato More articles by this author Koji Hatano More articles by this author Tsujikawa Kazutake More articles by this author Norio Nonomura More articles by this author Expand All Advertisement PDF downloadLoading ...

Chemomodulatory Potential of n-Hexane Extract of Conyza bonariensis Against Skin Carcinogenesis in Mice Induced by Carcinogens: An in Vitro and in Vivo Study

Conyza bonariensis (CB) is a cosmopolitan herb, family Asteraceae (Compositeae), commonly known as mrich booti or gulava previously used to cure cancer in traditional medicine. In the present study, n-hexane fraction by CB's triterpenoid constituents was assessed for their cytotoxic property using the human skin carcinoma cell line (SCC-13) and human peripheral blood mononuclear cells (PBMC). The chemo modulatory potential of CB n-hexane was evaluated against skin carcinogenesis in mice induced by (7-12-dimethylbenz(a)antheracene) DMBA and Croton oil. CB n-hexane extract was orally administered at the doses of 3, 6, and 9 mg/kg/day, and 9 mg/kg was also applied locally on mice skin for 16 weeks. The results from cell lines revealed that CB induces cytotoxicity against the SCC-13 cells (IC50=7.5 µM). It was found to be 4.05 times more selective in exerting cytotoxicity against SCC-13 than the PBMC (IC50=30.4 µM). The results from the mice model of skin carcinogenesis have shown that whole plant n-hexane extract administered via oral and topical routes, both reduced the number of precancerous skin papillomas and their incidence. At these concentrations, CB n-hexane also augmented the actions of catalase and superoxide dismutase, glutathione content and reduced the skin lipid peroxidation levels. These outcomes presented the cytotoxic and antioxidative effects of CB n-hexane whole plant extract and also authenticates the traditional assertions and strengthen the technical base of its chemopreventive activity.

Interleukin-34 deficiency aggravates development of colitis and colitis-associated cancer in mice

Although expression of interleukin (IL)-34 is upregulated in active ulcerative colitis (UC), the molecular function and underlying mechanism are largely unclear. To investigate the function of IL-34 in acute colitis, in a wound healing model and in colitis-associated cancer in IL-34-deficient mice. Colitis was induced by administration of dextran sodium sulfate (DSS), and carcinogenesis was induced by azoxymethane (AOM). Whether the impact of IL-34 on colitis was dependent on macrophages was validated by depletion of macrophages in a murine model. The association between IL-34 expression and epithelial proliferation was studied in patients with active UC. IL-34 deficiency aggravated murine colitis in acute colitis and in wound healing phase. The effect of IL-34 on experimental colitis was not dependent on macrophage differentiation and polarization. IL-34-deficient mice developed more tumors than wild-type mice following administration of AOM and DSS. No significant difference was shown in degree of cellular differentiation in tumors between wild-type and IL-34-deficient mice. IL-34 was dramatically increased in the active UC patients as previously reported. More importantly, expression of IL-34 was positively correlated with epithelial cell proliferation in patients with UC. IL-34 deficiency exacerbates colonic inflammation and accelerates colitis-associated carcinogenesis in mice. It might be served as a potential therapeutic target in UC.

Identification of a Novel GRHL3/HOPX/Wnt/β-Catenin Proto-oncogenic Axis in Squamous Cell Carcinoma of the Esophagus

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with a poor long-term prognosis. The molecular mechanisms underlying the initiation and progression of this tumor are largely unknown. The transcription factor GRHL3 functions as a potent tumor suppressor in SCC of skin, head, and neck. This study aims to determine whether GRHL3 also plays a role in the homeostasis of the esophageal epithelium and in the development of ESCC. The effects of Grhl3 deletion on squamous epithelial homeostasis in embryos and adult mice were examined using immunohistochemistry, transmission electron microscopy, and real-time polymerase chain reaction. The conditionally deleted mice were subsequently used to determine susceptibility to ESCC. Whole-transcriptome sequencing (RNA-seq) was performed on ESCC in wild-type and Grhl3 deleted animals. To decipher the signaling pathways, real-time polymerase chain reaction, immunohistochemistry, analysis of chromatin immunoprecipitation sequencing, chromatin immunoprecipitation-polymerase chain reaction, and RNA seq datasets were used. Primary human samples were used to validate the findings in the mouse model. Loss of Grhl3 perturbs the proliferation-differentiation balance in the esophageal epithelium, thereby increasing the susceptibility to esophageal carcinogenesis in adult mice. Grhl3 imparts its tumor suppressor function by regulating the expression of HOPX. We have identified the Wnt/β-catenin pathway as the downstream effectors of GRHL3 and HOPX through our integrated approach using patient-derived ESCC samples and mouse models. GRHL3 conveys its tumor suppressor function in ESCC through regulating its target gene HOPX, which limits Wnt/β-catenin signaling. Targeted therapies to inhibit thispathway could be a potential treatment strategy for ESCC patients with reduced GRHL3 expression.

Abstract B067: Genetic and pharmacological inhibition of phospholipase D1 reduces pancreatic carcinogenesis in mice

Abstract Pancreatic ductal adenocarcinoma (PDA) is a leading cause of cancer-related death in the United States and is characterized by its sudden manifestation, poor prognosis, high incidence of metastasis, and aggressive tumor growth. Phospholipase D1 (PLD1) is a lipid-signaling enzyme that plays a role in signaling pathways that lead to cell proliferation, survival/apoptosis as well as downstream oncogenic transformation involved in cancer progression. PLD1 activity has been shown to promote tumor progression in other cancer types, however, the role and mechanisms of PLD1 in pancreatic cancer is not yet understood. The objective of this study is to determine the role of PLD1 regulation in pancreatic carcinogenesis through genetic-ablation and pharmacological inhibition of PLD1. In this study, we crossed the LSL-KrasG12D/+;Ptf1Cre/+ (KC) mice into PLD1 knockout (Pld1-/-) mice to generate KC; Pld1-/- mice in the C57BL/6 background to examine whether PLD1 is required for pancreatic tumorigenesis. Cohorts of male and female KC and KC; Pld1-/- mice, (8-12 mice per group), were euthanized at 4 and 8 months old and the pancreas was carefully resected. At 8 months of age, there was a significant difference (p<0.05) in the pancreas weight at sacrifice between the KC mice and the KC; Pld1-/- mice in a sex-dependent manner. This was due, in part, by a reduction in tumor proliferation as determined by Ki67 expression. To assess whether pharmacological inhibition of PLD could prevent pancreatic carcinogenesis in KC mice, cohorts of 9-12 male 7-month-old KC mice received daily intraperitoneal injections of a small molecule inhibitor of PLD (FIPI) at a dosage of 3 mg/kg of body weight for a duration of 5 weeks. The mice were euthanized at 8.5 months of age and the pancreas was carefully resected. Histological analysis indicated that FIPI-treated KC mice displayed less acinar cell loss compared to vehicle-treated KC controls. Moreover, treatment with FIPI significantly reduced cell proliferation (p<0.01) in KC mice in comparison to vehicle-treated KC mice. In summary, these results indicate that PLD1 plays a critical role in pancreatic carcinogenesis and may represent a novel therapeutic target. Additional studies are underway to explore the cellular mechanisms of how PLD1 inhibition modulates pancreatic carcinogenesis. Citation Format: Hala A. Addassi, Gerardo G. Mackenzie. Genetic and pharmacological inhibition of phospholipase D1 reduces pancreatic carcinogenesis in mice [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B067.

Amination Potentially Augments the Ameliorative Effect of Curcumin on Inhibition of the IL-6/Stat3/c-Myc Pathway and Gut Microbial Modulation in Colitis-Associated Tumorigenesis.

Epigallocatechin gallate and tetrahydrocurcumin are aminated as colonic metabolites, preserving their bioactivities and improving their capabilities. We compared the bioactivities of unaminated (CUR) and aminated (AC) curcumin in inflammatory colitis-associated tumorigenesis. The anti-inflammatory and anticancer capabilities of CUR and AC were evaluated using RAW264.7 and HT29 cell lines, respectively. An azoxymethane/dextran sodium sulfate-induced colitis-associated carcinogenesis mouse model was used with CUR and two-dose AC interventions. AC had a greater anti-inflammatory effect but a similar anticancer effect as CUR in vitro. CUR and low-dose AC (LAC) significantly preserved colon length and reduced tumor number in vivo. Both CUR and LAC inhibited activation of the protein kinase B (AKT)/nuclear factor kappa B (NF-κB) signaling pathway, its downstream cytokines, and the interleukin (IL)-6/signal transducer and activator of transcription 3 (STAT3)/c-myelocytomatosis oncogene (c-MYC) pathway. However, only LAC significantly preserved E-cadherin, reduced N-cadherin, and facilitated beneficial gut microbial growth, including Akkermansia and Bacteroides, potentially explaining AC's better ameliorative effect at low than high doses.

PHYTOMODULATORY EFFECTS OF MURRAYA KOENIGII IN DMBA/TPA INDUCED ANGIOGENESIS, HEPATOTOXICITY AND RENAL TOXICITY DURING SKIN CARCINOGENESIS IN MICE

The present study was aimed to evaluate the protective effects of Hydroethanolic Murraya koenigii leaves extract (HEMKLE) against DMBA/TPA-induced angiogenesis, hepatotoxicity and renal toxicity during skin carcinogenesis in mice. For the study, male LACA mice were divided into four groups: Group I (C), Group II (DMBA/TPA), Group III (HEMKLE), and Group IV (HEMKLE+DMBA/TPA). 7, 12-dimethylbenz(a) anthracene (DMBA), and 12-O-tetradecanoyl phorbol-13-acetate (TPA) were applied on the depilated skin of the mice to raise skin tumors in Group II and Group IV. The chemopreventive response of HEMKLE was evident by histoarchitectural and morphometric analysis of skin/tumors in Group IV (HEMKLE+DMBA/TPA). In addition, HEMKLE administration also decreased the mRNA and protein expression of HIF-1α, HMOX-1, VEGF, bFGF, and ANGPT-2 in Group IV (HEMKLE+DMBA/TPA) when compared to Group II (DMBA/TPA) that suggest its anti-angiogenic effect. Moreover, HEMKLE administration protected the liver and kidney tissues from damages incurred during skin carcinogenesis as evident through histological analysis, assessment of ROS and LPO levels, assessment of liver and kidney function markers (viz., SGOT, SGPT, D-bilirubin, T-bilirubin, ALP, urea, creatinine and BUN) and activities of the antioxidant enzymes in Group IV (HEMKLE +DMBA/TPA) when compared to Group II (DMBA/TPA). The outcome of the present study showed that HEMKLE administration markedly alleviated the angiogenesis and also showed the protective effects against damages incurred in liver and kidney tissues during skin carcinogenesis. However, further extensive studies are needed to explore the efficacy of HEMKLE on metastasis before going to human trials.

Shenbai Jiedu Fang inhibits AOM/DSS-induced colorectal adenoma formation and carcinogenesis in mice via miRNA-22-mediated regulation of the PTEN/PI3K/AKT signaling pathway

To observe the inhibitory effect of Shenbai Jiedu Fang (SBJDF, a compound recipe of traditional Chinese herbal drugs) on chemically induced carcinogenesis of colorectal adenoma in mice and explore the role of PTEN/PI3K/AKT signaling pathway in mediating this effect. Four-week-old male C57BL/6 mice were randomly divided into control group (n=10), AOM/DSS model group (n=20), low-dose (14 g/kg) SBJDF group (n=10) and high-dose (42 g/kg) SBJDF group (n= 10). In the latter 3 groups, the mice were treated with azoxymethane (AOM) and dextran sodium sulphate (DSS) to induce carcinogenesis of colorectal adenoma. In the two SBJDF treatment groups, SBJDF was administered daily by gavage during the modeling. The survival rate, body weight, general condition of the mice, and intestinal adenoma formation and carcinogenesis were observed. The expressions of proteins associated with the PTEN/PI3K/AKT signaling pathway in the intestinal tissue were detected using immunohistochemistry. Compared with those in the model group, the mice treated with SBJDF, especially at the high dose, showed a significantly lower incidence of intestinal carcinogenesis and had fewer intestinal tumors with smaller tumor volume. Pathological examination showed the occurrence of adenocarcinoma in the model group, while only low-grade and high-grade neoplasia were found in low-dose SBJDF group; the mice treated with high-dose SBJDF showed mainly normal mucosal tissues in the intestines with only a few lesions of low-grade neoplasia of adenoma. Compared with those in the control group, the mice in the model group had significantly elevated plasma miRNA-222 level (P < 0.05), which was obviously lowered in the two SBJDF groups (P < 0.01). The results of immunohistochemistry revealed that compared with the model group, the two SBJDF groups, especially the high-dose group, had significantly up-regulated expressions of PTEN, P-PTEN and GSK-3β and down-regulated expressions of p-GSK-3 β, PI3K, AKT, P-AKT, β-catenin, c-myc, cyclinD1 and survivin in the intestinal tissues. SBJDF can significantly inhibit colorectal adenoma formation and carcino-genesis in mice possibly through regulating miRNA-222 and affecting PTEN/PI3K/AKT signaling pathway.

A new method for the preparation of a purified glucosylceramide and ceramide from shiitake mushroom

Ingestion of plant and fungal glucosylceramides is known to reduce colon carcinogenesis and skin barrier damage in mice and humans. However, such effects in animal experiments have not been revealed for plant and fungal ceramides because the content of ceramides contained in plants and fungi is so low that the large amount required for animal experiments is difficult to obtain. Noting that the fungus shiitake mushroom (Lentinula edodes) is rich in a glucosylceramide, (4E,8E)-N-d-2'-hydroxypalmitoyl-1-O-β-d-glucopyranosyl-9-methyl-4,8-sphingadienine [Glc-d19:2(4E,8E,9Me)-h16:0], we developed a new method to purify this fungal glucosylceramide using ethanol precipitation and high-performance liquid chromatography. We also developed a new method to produce large amounts of a ceramide [d19:2(4E,8E,9Me)-h16:0] from this purified glucosylceramide using human glycoside hydrolase family 30 glucocerebrosidase (imiglucerase). These methods will be useful for elucidating the physiological function by ingestion of fungal ceramides in animal experiments.

Impact of Cyanotoxin Ingestion on Liver Cancer Development Using an At-Risk Two-Staged Model of Mouse Hepatocarcinogenesis.

Exposure to cyanobacterial hepatotoxins has been linked to the promotion and increased incidence of liver cancer in pre-clinical and epidemiologic studies. The family of hepatotoxins, microcystins (MCs), are produced by over 40 cyanobacterial species found in harmful algal blooms (HABs) worldwide, with MC-LR being the most common and potent MC congener. In the current study, we hypothesized that the low-dose chronic ingestion of Microcystis cyanotoxins via drinking water would promote liver carcinogenesis in pre-initiated mice. Four groups of C3H/HeJ mice received one intraperitoneal (i.p.) injection of diethylnitrosamine (DEN) at 4 weeks of age. Three weeks later, the mice were administered ad libitum drinking water containing one of the following: (1) reverse osmosis, deionized water; (2) water containing 500 mg/L phenobarbital (PB500); (3) water with purified MC-LR (10 µg/L) added; or (4) water containing lysed Microcystis aeruginosa (lysate; 10 µg/L total MCs). The exposure concentrations were based on environmentally relevant concentrations and previously established Ohio EPA recreational water MC guidelines. Throughout the 30-week exposure, mouse weights, food consumption, and water consumption were not significantly impacted by toxin ingestion. We found no significant differences in the number of gross and histopathologic liver lesion counts across the treatment groups, but we did note that the PB500 group developed lesion densities too numerous to count. Additionally, the proportion of lesions classified as hepatocellular carcinomas in the MC-LR group (44.5%; p < 0.05) and lysate group (55%; p < 0.01) was significantly higher compared to the control group (14.9%). Over the course of the study, the mice ingesting the lysate also had a significantly lower survival probability (64.4%; p < 0.001) compared to water (96.8%), PB500 (95.0%), and MC-LR (95.7%) exposures. Using cyanotoxin levels at common recreational water concentration levels, we demonstrate the cancer-promoting effects of a single cyanotoxin MC congener (MC-LR). Furthermore, we show enhanced hepatocarcinogenesis and significant mortality associated with combinatorial exposure to the multiple MCs and bioactive compounds present in lysed cyanobacterial cells—a scenario representative of the ingestion exposure route, such as HAB-contaminated water and food.

The carbonic anhydrase inhibitor acetazolamide inhibits urinary bladder cancers via suppression of β-catenin signaling.

Carbonic anhydrases (CAs) play an important role in maintaining pH homeostasis. We previously demonstrated that overexpression of CA2 was associated with invasion and progression of urothelial carcinoma (UC) in humans. The purpose of the present study was to evaluate the effects of the CA inhibitor acetazolamide (Ace) on N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN)‐induced bladder carcinogenesis in mice and explore the function of CA2 in muscle invasion by UC. Male mice were treated with 0.025% (experiment 1) or 0.05% BBN (experiment 2) in their drinking water for 10 weeks, then treated with cisplatin (Cis), Ace, or Cis plus Ace for 12 weeks. In experiment 1, the overall incidence of BBN‐induced UCs was significantly decreased in the BBN→Ace and BBN→Cis+Ace groups. In experiment 2, the overall incidence of BBN‐induced UCs was significantly decreased in the BBN→Cis+Ace group, and the incidence of muscle invasive UC was significantly decreased in both the BBN→Ace and the BBN→Cis+Ace groups. We also show that overexpression of CA2 by human UC cells T24 and UMUC3 significantly increased their migration and invasion capabilities, and that Ace significantly inhibited migration and invasion by CA2‐overexpressing T24 and UMUC3 cells. These data demonstrate a functional association of CA2 with UC development and progression, confirming the association of CA2 with UC that we had shown previously by immunohistochemical analysis of human UC specimens and proteome analysis of BBN‐induced UC in rats. Our finding that inhibition of CA2 inhibits UC development and muscle invasion also directly confirms that CA2 is a potential therapeutic target for bladder cancers.

FRI559 - Genetic ablation of miR-22 fosters hepatic carcinogenesis in mice

FRI559 - Genetic ablation of miR-22 fosters hepatic carcinogenesis in mice

Molecular interaction of cryptophycin 52 with Caspase 8 for the management of lung cancer during coronavirus outbreak : A computational study.

It has been seen that, during COVID-19 outbreak lung cancer (LC) patients are noted as a high-risk population which make a more challenging to treatment of the LC patients. The active form of caspase-8 is involved in lung carcinogenesis in both humans and mice. In this study, the virtual screening was performed among 200 compounds retrieved from several resources for the searching of potent lead against Caspase 8 (Casp8). Cryptophycin 52 was found to have a strong inhibiting efficacy based on the free energy of binding with the active site of Casp8. The lowest binding energy was found to be -8.05 kcal/mole and was further analyzed for molecular dynamic simulation. Casp8 enzyme was determined to interact with cryptophycin 52 through twelve amino acid residues, specifically ARG260, SER316, GLY318, ASP319, THR337, VAL354, PHE355, PHE356, ILE357, GLN358, ALA359 and CYS360 along with six hydrogen bond particular, ILE357:N-UNK1: O7, UNK1: O14-PHE355:O, UNK1: C25-PHE355:O, UNK1: C35-THR337:O, UNK1: H65-HE355:O and UNK1: C25-PHE356. In addition, MD simulations for 50ns were performed for optimization, flexibility estimation and assessment of Casp8-cryptophycin 52 complex stability. This complex was seen as reasonably stable according to the RMSD, RMSF, and radius of gyration graph. Results obtained indicate cryptophycin 52 may be a lead compound with significant anti-cancer ability against Casp8. Further experimental work, however, is expected to support the compound's anti-cancer viewpoint.

Protective effects of andrographolide sodium bisulfate on UV-induced skin carcinogenesis in mice model

Although the mortality of skin cancer patients is relatively low, there are still a large number of patients died of these tumors at high incidence rate. Chronic exposure to solar UV irradiation is the most common cause of nonmelanoma skin tumors. Our research aimed to explore the effects of andrographolide sodium bisulfate (ASB) on UV-induced skin cancer and to reveal the underlying molecular mechanism. In the present study, histopathology changes, immunohistochemical analysis, ELISA analysis and western blot analysis were mainly used in vivo. The results indicated that ASB significantly inhibited increase of skin epidermal thickness, inflammatory cells infiltration and fibers damage in dermis, oxidative stress injury and skin carcinogenesis. Moreover, the western blot analysis showed that protein expressions of NF-κB, Nrf2, p62, LC3 II/I and p-p62 (Ser 349) in mouse skin induced by UV were dramatically suppressed in the ASB-pretreated groups. Overall, these results suggested that ASB exerted a strong preventive effect and potential therapeutic value against UV-induced skin carcinogenesis in mice through inhibiting NF-κB and Nrf2 signaling pathways and restoring autophagy.

A Biscuit Containing Fucoxanthin Prevents Colorectal Carcinogenesis in Mice

Fucoxanthin (Fx) is a critical pigment required for photosynthesis in brown algae and microalgae. Fx is also a dietary marine carotenoid that with potent anticancer activity in vitro and in vivo. Some popular light meals for increased satiety, such as biscuits, cereals, and crackers, are frequently fortified with micronutrients for human health benefits. However, data on the anticancer potential of Fx-supplemented light meals in humans and animal models remain limited. In the present study, we investigated the anticancer effects of a Fx-supplemented biscuit using a carcinogenic murine azoxymethane/dextran sodium sulfate (AOM/DSS) model. We observed that periodic administration of biscuits containing 0.3% Fx (Fx-biscuit) at an interval of 3 days (each 15 h) per week for 15 weeks significantly inhibited colorectal carcinogenesis in AOM/DSS mice. Comprehensive gene analysis demonstrated that the Fx-biscuit significantly altered the expression of 138 genes in the colorectal mucosal tissue of the mice. In particular, the expression of heat shock protein 70 (HSP70) genes, Hspa1b (–35.7-fold) and Hspa1a (–34.9-fold), was markedly downregulated. HSP70 is a polyfunctional chaperone protein that is involved in cancer development. Compared to the control-biscuit group, the number of cells with markedly high fluorescence for HSP70 protein (HSP70high) in colorectal mucosal crypts and adenocarcinomas significantly reduced by 0.3- and 0.2-fold, respectively, in the Fx-biscuit group. Our results suggested that Fx-biscuit possesses chemopreventive potential in the colorectal cancer of AOM/DSS mice via the downregulation of HSP70.

Caffeine and Chlorogenic Acid Combination Attenuate Early-Stage Chemically Induced Colon Carcinogenesis in Mice: Involvement of oncomiR miR-21a-5p.

Colorectal cancer (CRC) is one of most common cancers worldwide, with high rates of mortality. Epidemiological findings demonstrate that coffee consumption reduces the risk of developing CRC by ~13%. In general, in vivo and in vitro findings demonstrate the antiproliferative, antioxidant and proapoptotic effects of brewed coffee or major bioavailable coffee compounds. Thus, it was assessed whether caffeine (CAF) and/or chlorogenic acid (CGA) attenuates the early-stage of chemically induced mouse colon carcinogenesis. Male Swiss mice were submitted to a 1,2-dimethylhydrazine/deoxycholic acid (DMH/DCA)-induced colon carcinogenesis model. These animals received CAF (50 mg/kg), CGA (25 mg/kg) or CAF+CGA (50 + 25 mg/kg) intragastrically for five times/week for ten weeks. CAF+CGA had the most pronounced effects on decreasing epithelial cell proliferation (Ki-67) and increasing apoptosis (cleaved caspase-3) in colonic crypts. This treatment also decreased the levels of proinflammatory cytokines IL-6, IL-17 and TNF-α, and downregulated the oncomiR miR-21a-5p in the colon. Accordingly, the analysis of miR-21a-5p targets demonstrated the genes involved in the negative regulation of proliferation and inflammation, and the positive regulation of apoptosis. Ultimately, CAF+CGA attenuated preneoplastic aberrant crypt foci (ACF) development. Our findings suggest that a combination of coffee compounds reduces early-stage colon carcinogenesis by the modulation of miR-21a-5p expression, highlighting the importance of coffee intake to prevent CRC.

Kub5‐Hera Deficiency Promotes R‐Loop‐Induced Genomic Instability and Carcinogenesis Following Whole‐Body Exposure to Ionizing Radiation

Formation of persistent R‐loops (a structure containing an RNA:DNA hybrid and a displaced single‐stranded DNA) during transcription are now emerging as a direct threat to genomic stability with links to cancer and various neurodegenerative, autoimmune, and developmental disorders. However, the molecular mechanisms by which R‐loops are resolved or aberrantly formed to induce DNA damage and genomic instability remains unclear. Aberrant accumulation of these nucleic acid structures through compromised transcription and exposure to genotoxic agents (e.g., ionizing radiation, IR) imposes a roadblock to ongoing replication and transcription causing genomic instability by generating double‐stranded DNA breaks (DSBs). Kub5‐Hera (Ku70‐binding protein 5‐Hera, K‐H; also known as RPRD1B, Regulation of nuclear pre‐mRNA‐domain‐containing protein 1B) is a novel factor discovered in our lab that is involved in transcription termination and DNA repair. We found that loss of K‐H increases R‐loop‐induced DSBs that activates the error‐prone alternative non‐homologous end‐joining (alt‐EJ or back‐up NHEJ) due to defects in classical NHEJ (c‐NHEJ) and homologous recombination (HR). Using our transgenic mouse model, we discovered that a complete knockout of K‐H is embryonic lethal suggesting a critical role for this protein in cellular development and proliferation. Interestingly, deletion of one K‐H allele in mice caused rapid development of cancer‐related deaths over time after whole‐body exposure to IR in a dose‐dependent manner compared to their wild‐type littermates. Using targeted gene silencing, western blot, proximity ligation and immunofluorescent assays in our cell line models and mouse tissues, we showed that depletion of K‐H increases the formation of R‐loop‐induced double‐stranded breaks (DSBs) and PARP1 activity due to a compromised homologous recombination (HR). Loss of K‐H in cells increases the error‐prone activity of PARP1 in alt‐EJ to possibly repair harmful R‐loop‐induced single‐stranded breaks (SSBs) and DSBs due to HR and c‐NHEJ deficiency, which could provide the mechanism of carcinogenesis in mice after exposure to IR. Overall, our studies offer new mechanistic insights into carcinogenesis caused by K‐H genetic alterations and persistent R‐loops, as well as identify novel strategies to leverage Kub5‐Hera expression or the formation of lethal R‐loop‐induced‐DSBs for innovative therapeutic approaches.