Rat Model Of Colorectal Cancer Research Articles

Banxia Xiexin Decoction inhibits colitis-associated colorectal cancer development by modulating STAT3 signaling and gut microbiota

ObjectiveTo investigate the therapeutic effects of Banxia Xiexin Decoction (BXD), a herbal medicine formula, on inflammation and the imbalance of the gut microbiota in a rat model of colorectal cancer (CRC) induced by azoxymethane (AOM) /dextran sulfate sodium (DSS). MethodsA total of 75 male C57BL/6 mice were randomly divided into five groups: normal control group (NC), model group (MODEL), low-dose BXD treatment group (L-BXD), high-dose BXD treatment (H-BXD) group and MS treatment group (MS). BXD and MS were used in CRC mice at the doses of 3.915 g/kg, 15.66 g/kg, 0.6 g/kg for 3 weeks consecutively.Histopathological changes in the colon were observed using hematoxylin-eosin (HE) staining. The content of inflammatory factors in serum was detected by an enzyme-linked immunosorbent assay (ELISA), and the expression of mRNA and protein of genes related to immunity, apoptosis, inflammation, and inflammatory factors was evaluated. Changes in the intestinal flora of mouse fecal were determined based on high-throughput sequencing of the 16S rRNA microbial gene. ResultsCompared to the model group, the low-dose BXD and high-dose BXD groups decreased the number of colon tumors, reversed weight loss, and shortened colon length of mice. The pathological examination showed that BXD alleviated the malignancy of intestinal tumors. It also suppressed signal transducer and activator of transcription 3 (STAT3), matrix metalloproteinase-9 (MMP-9), and transforming growth factor beta 1 (TGF-β1) expression, while increasing the expression of the tight junction protein ZO-1 in colon tissues. Additionally, the levels of key pathway proteins involved in inflammation (phosphorylated-STAT3, Bcl-2, COX-2) and cell cycle regulatory molecules (c-Myc and PCNA) were reduced. According to 16S rRNA sequence analysis, BXD enhanced the relative abundance of potentially beneficial bacteria, while that of cancer-related bacteria decreased. ConclusionBXD plays a preventive role in developing colorectal cancer; its mechanisms are related to the inhibition of inflammation and tumor proliferation, as well as maintenance of intestinal homeostasis.

Pharmacokinetic evaluation of oxaliplatin combined with S-1 (SOX) chemotherapy in a rat model of colorectal cancer with acute kidney injury: predictive renal biomarkers for dose optimisation

Dose adjustment based on renal function is essential in S-1, which contains the 5‑fluorouracil prodrug tegafur, and platinum-based agent oxaliplatin (SOX) combination chemotherapy for colorectal cancer in patients with chronic kidney disease. However, limited evidence on dose adjustment in acute kidney injury (AKI) and challenges in determining dosing strategies. This study investigated the pharmacokinetics of SOX chemotherapy and renal biomarkers in rats. AKI was prepared by renal ischaemia-reperfusion injury in 1,2-dimethylhydrazine-induced colorectal cancer model rats. Serum creatinine (sCr) levels were determined as a renal biomarker. After administration of S-1 (2 mg/kg tegafur) and oxaliplatin (5 mg/kg), drug concentrations of tegafur, 5-FU, and platinum were measured in the plasma and tumours. No alterations in the area under the plasma concentration–time curve (AUC0-24h ) values of 5-fluorouracil were observed between control and AKI model rats. The tumour concentrations of 5-fluorouracil in the mild and severe AKI groups were significantly lower than control group. The AUC0-24h for platinum increased with AKI severity. Notably, population pharmacokinetic analysis identified sCr as a covariate in platinum distribution after SOX chemotherapy. To optimise dose adjustment of SOX chemotherapy in patients with AKI, sCr may be a key factor in determining the appropriate dose.

Anti-inflammatory and antioxidant effect of methanol extract of latex of Calotropis procera in rat model of colorectal cancer

Ethnopharmacological relevancePreparations derived from the plant Calotropis procera, have been used for medicinal purpose though the plant is known for its toxic effects. The aerial parts of the plant contain latex in plenty and have been found effective in treating disorders of gastrointestinal system and cancer. Aim of the studyThis study evaluated the efficacy of C. procera dried latex extract prepared in methanol (MeDL) against inflammation and oxidative stress in experimental model of colorectal carcinoma (CRC). Materials and methodsTwo subcutaneous injections of chemical carcinogen, 1,2-dimethylhydrazine (DMH; 150 mg/kg) were given at an interval of one week to induce CRC in rats. The MeDL (50 and 150 mg/kg) and aspirin (60 mg/kg) were given daily and their effect was evaluated on markers of oxidative stress and inflammation after completion of 8 weeks following second injection of carcinogen. A comparison was made with normal and experimental control groups. The colon tissue levels of glutathione (GSH), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), nitrite and myeloperoxidase (MPO) were determined. Enzyme-linked immunosorbent assay was performed to determine the levels of prostaglandin E2 (PGE2) and tumor necrosis factor-alpha (TNF-α) and immunohistochemical analysis was performed for IL-1β. ResultsInduction of cancerous changes in the colon resulted in altered oxidative homeostasis as evident from a reduction in GSH level and SOD activity and rise in TBARS level when compared with normal rats. Elevated levels of nitrite, MPO, TNF-α, PGE2 and immunoreactivity of IL-1β were also observed in these rats. The levels of these markers were normalized when the rats were treated with MeDL or anti-inflammatory drug, aspirin. ConclusionThis study demonstrates that suppression of oxidative stress and inflammation contributes to the beneficial effect of MeDL in rat model of colon carcinogenesis.

Effects of atmospheric low temperature plasma on the rat model of colorectal cancer

Effects of atmospheric low temperature plasma on the rat model of colorectal cancer

The Effects of Plasma-Activated Saline and Medium on Colorectal Cancer in Rat Models and the Human Colon Adenocarcinoma Cell Line COLO 205

Colorectal cancer affects a large number of people. There is an urgent need to develop novel treatments for this disease. In recent years, research on medical applications of atmospheric low temperature plasma (ALTP) has been actively conducted, and cancer treatment is one of the targets. In this study, we focused on colorectal cancer and evaluated plasma as a new treatment method. In vivo and in vitro experiments were conducted using plasma-treated saline (PTS) and plasma-treated medium (PTM) prepared by submerged bubbling treatment using ALTP. In vivo experiments using a rat model of colorectal cancer revealed that PTS administration to the colon slowed tumor progression based on endoscopic and histopathological observations. To investigate the cause of the inhibition of tumor progression, we evaluated the impact of ALTP on colon cancer cells. As a result of culturing colorectal cancer cells with PTM, cell proliferation was inhibited. Also, cell death was induced by cell swelling. qPCR revealed that PTMs induced cell death of cancer cells through signaling of tumor necrosis factor α (TNF-α), an inflammatory cytokine. Therefore, the inhibition of cancer progression by PTS in the rat model occurs by inducing cell death through the dissolution of ALTP components in the liquid.

Reposition of the anti-inflammatory drug diacerein in an in-vivo colorectal cancer model

Excessive interleukin (IL)-6 production is a driver for malignancy and drug resistance in colorectal cancer (CRC). Our study investigated a seven-week post-treatment with the anti-inflammatory drug, Diacerein (Diac), alone or in combination with 5-fluorouracil (5-FU), using a 1,2-dimethylhydrazine (DMH) rat model of CRC. Diac alone and 5-FU+Diac reduced serum levels of carcino-embryonic antigen (CEA), while all regimens decreased serum levels of colon cancer-specific antigen (CCSA), a more specific CRC biomarker. Additionally, Diac, 5-FU and their combination suppressed colonic content/gene expression of IL-6, its downstream oncogene, Kirsten rat sarcoma viral oncogene homolog (K-Ras), and consequently Notch intracellular domain and nuclear factor-kappa B (NF-κB) p65. In turn, NF-κB downstream factors, viz., matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), c-Myc, and B-cell lymphoma-2 (Bcl-2) were also downregulated, while E-cadherin was elevated. Additionally, the drugs reduced the immunoreactivity of CD31 to prove their anti-angiogenic effect, while the TUNEL assay confirmed the apoptotic effect. The apoptotic effect was confirmed by transferase dUTP nick-end labeling assay. Moreover, these drugs inhibited colon content of p-Akt, β-catenin, and cyclin D1 immunoreactivity. The drugs also activated the tumor suppressor glycogen synthase kinase 3- β (GSK3-β) and upregulated the expression of the Nur77 gene, which represents the second arm of IL-6 signaling. However, only 5-FU upregulated miR-200a, another K-Ras downstream factor. The in-vitro cytotoxic and migration/invasion assays verified the molecular trajectories. Accordingly, we evaluated the antineoplastic effect of Diac alone and its possible chemosensitization effect when added to 5-FU. This combination may target critical oncogenic pathways, including the IL-6/K-Ras/Notch/NF-κB p65 axis, p-Akt/GSK3-β/β-catenin/cyclin D-1 hub, and Nur77.

Survival effect of probiotics in a rat model of colorectal cancer treated with capecitabine.

BACKGROUNDProbiotics are used to manage a number of gastrointestinal disorders due to their beneficial properties. Clinical reports showed that probiotics also improve the life quality of patients with colorectal cancer (CRC) subjected to oncologic treatment. In a CRC animal model, probiotics supplementation has the potential to decrease the formation of aberrant crypts and ameliorate tumor malignancy, enhancing the antitumor effect of 5-fluorouracil (5-FU) chemotherapy. Based on these data, we hypothesize that the administration of probiotics impact positively in the overall survival and life quality of rats with CRC under the treatment of capecitabine, which is the pro drug of 5-FU. AIMTo evaluate the probiotics effects in a rat CRC model treated with capecitabine and followed until the end of life.METHODS1,2-Dimethylhidrazine dihydrochloride (1,2-DMH) was employed as carcinogen inductor of CRC. Fifty male Wistar-Lewis rats were randomly assigned to one of five following groups: Control (n = 5), Control + probiotics (Control-P group, n = 5), 1,2-DMH alone (DMH group, n = 10), 1,2-DMH + capecitabine (DMH-C group, n = 10), 1,2-DMH + probiotics (DMH-P group, n = 10) and 1,2-DMH + capecitabine + probiotics (DMH-C-P group, n = 10). All parametric data were expressed as the mean ± SD. The statistical significance of differences was analyzed using one-way ANOVA. Data were analyzed with InfoStat software. The results were considered statistically significant at P < 0.05. Overall survival was evaluated with the Kaplan-Meier estimator with the log-rank test.RESULTSThe data of mean overall survival for DMH, DMH-P, DMH-C, DMH-C-P, Control and Control-P groups were 250 d [95% confidence interval (CI): 242.5-253.1], 268 d (95%CI: 246.3-271.4), 380 d (95%CI: 337.8-421.9), 480 d (95%CI: 436.9-530.7), 588 d (95%CI: 565.8-609.3) and 590 d (95%CI: 564.3-612.9), respectively, with a significant difference between DMH-C and DMH-C-P groups (P = 0.001). Comparing all groups by Kaplan-Meier estimator, we found a significantly different in the overall survival of DMH and DMH-P groups respect to DMH-C (P = 0.001) and DMH-C-P (P = 0.001) groups; interestingly, there were no meaningful differences between Control, Control-P and DMH-C-P groups (P = 0.012). The tendency of change in body weight gain of the rats at 90 d of finishing DMH administration was similar in Control group compared with DMH-C and DMH-C-P groups; however, and of relevance, DMH-C-P group has experienced a higher body weight gain at the end of animal’s life than DMH-C group (P = 0.001). In DMH-C-P group we found a positive effect of probiotics in clinical manifestations since diarrhea, constipation and blood stool were absenting. Also, the tumor burden was lower in DMH-C-P than DMH-C, DMH-P or DMH groups (1.25 vs 1.81 vs 3.9 vs 4.8 cm2, respectively). DMH-C and DMH-C-P groups showed only mucinous carcinoma type while in other DMH groups the tumor types were variable. However, mucinous carcinoma from DMH-C-P group showed invasion until muscularis propria layer. Interestingly, metastatic lymph node was observed in DMH, DMH-C and DMH-P groups but not in DMH-C-P. All animals in Control group died from natural causes without objective injuries. All animals of DMH and DMH-P groups died from tumor complications (i.e., obstruction or intestinal perforation); however, this cause was seen only in 44.5% of DMH-C and DMH-C-P groupsCONCLUSIONProbiotics administration improves life quality of rats with CRC under capecitabine treatment and also has a positive effect in the overall survival of these animals treated with this drug.

Protective effect of methanol extract of latex of Calotropis procera in an experimental model of colorectal cancer

Ethnopharmacological relevanceThe plant, Calotropis procera, has been used for treating various gastrointestinal disorders and cancer. Some of these medicinal properties have been attributed to the latex produced by the plant. Aim of the studyTo evaluate the efficacy of methanol extract of air-dried latex (MeDL) of C. procera in the rat model of colorectal cancer (CRC). Materials and methodsCRC was induced in the rats by 1,2-dimethylhydrazine (DMH) and the effect of MeDL was evaluated at two doses (50 and 150 mg/kg). MeDL and reference drug aspirin (60 mg/kg) were administered orally starting from 1 h before injecting DMH till 8 weeks after the second dose of DMH. The study also included experimental and normal control groups. Microscopic analysis was carried out to determine the count for aberrant crypt foci (ACF) and histology score whereas enzyme-linked immunosorbent assay and immunohistochemical analyses were performed for markers of carcinogenesis and angiogenesis. Other parameters that were evaluated include deoxyribonucleic acid (DNA) fragmentation, laddering, Bcl2 and Bax immunoreactivity, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity. ResultsSubcutaneous injection of DMH induced pre-neoplastic changes in the colon of rats with the appearance of ACF with multiple crypts (1–3, 4–6 or >6). In the experimental control group, total ACF count was 3.49 ± 0.23/cm of the colon length and the median histology score was 2.0 for architectural abnormalities, 2.0 for dilatation of crypts and 1.5 for hyperplasia/dysplasia against 1.0 for all the characteristics in normal rats. Oral administration of MeDL similar to aspirin, led to a reduction in ACF count and histology score of CRC concomitant with a decrease in the levels of markers of carcinogenesis - β-catenin and proliferating cell nuclear antigen (PCNA); markers of angiogenesis - matrix metallopeptidase-9 (MMP-9) and vascular endothelial growth factor (VEGF), and an increase in apoptotic DNA fragmentation. ConclusionMeDL confers protection in the rat model of CRC and the study suggests its therapeutic potential in this condition.

Proton Pump Inhibitor Omeprazole Suppresses Carcinogen-induced Colonic Adenoma Progression to Adenocarcinoma in F344 Rat.

Colorectal cancer causes over 53,000 deaths annually in the United States. Its rising incidences worldwide and particularly in young adults is a major concern. Here, we evaluated the efficacy of omeprazole that is clinically approved for treating acid reflux, to enable its repurposing for colorectal cancer prevention. In the azoxymethane-induced rat colorectal cancer model, dietary omeprazole (250 and 500 ppm) was administered at early adenoma stage (8 weeks after azoxymethane) to assess the progression of early lesions to adenocarcinoma. Administration of omeprazole at 250 or 500 ppm doses led to suppression of total colon adenocarcinoma incidence by 15.7% and 32% (P < 0.01), respectively. Importantly, invasive carcinoma incidence was reduced by 59% (P < 0.0005) and 90% (P < 0.0001) in omeprazole-administered rats in a dose-dependent manner. There was also a strong and dose-dependent inhibition in the adenocarcinoma multiplicity in rats exposed to omeprazole. Administration of 250 and 500 ppm omeprazole inhibited total colon adenocarcinoma multiplicity by approximately 49% and approximately 65% (P < 0.0001), respectively. While noninvasive adenocarcinomas multiplicity was suppressed by approximately 34% to approximately 48% (P < 0.02), the invasive carcinomas multiplicity was reduced by approximately 74% to approximately 94% (P < 0.0001) in omeprazole-exposed rats in comparison with the untreated rats. Biomarker analysis results showed a decrease in cell proliferation and anti-apoptotic/pro-survival proteins with an increase in apoptosis. Transcriptome analysis of treated tumors revealed a significant increase in adenocarcinoma inhibitory genes (Olmf4; Spink4) expression and downregulation of progression promoting genes (SerpinA1, MMP21, IL6). In summary, omeprazole showed significant protection against the progression of adenoma to adenocarcinoma. PREVENTION RELEVANCE: Preventing colon cancer is urgently needed because of its high incidence and mortality rates worldwide. Toward this end, preventive efficacy of omeprazole, a common medication, was evaluated in animal model of colorectal cancer and was found to suppress colonic adenoma progression to carcinoma. These findings warrant its further evaluation in humans.

RNF6 promotes colorectal cancer invasion and migration via the Wnt/β-catenin pathway by inhibiting GSK3β activity

BackgroundThe purpose of this study was to explore the molecular mechanism underlying the interaction between ring finger protein 6 (RNF6) and glycogen synthase kinase 3β (GSK3β) in colorectal cancer (CRC). MethodsIn this study, cell models of overexpressed or silenced RNF6 were established by liposome transfection, and IM-12 was used as the inhibitor of GSK3β. Real-time quantitative PCR and western blots were used to detect the expression of RNF6, p-GSK3β, GSK3β, and β-catenin, and MTT assays were used to quantify cell proliferation. The tumorigenicity of cells was observed by plate clonal formation assay; the invasiveness of cells was examined in Transwell Boyden chambers, and the migratory capacity of cells was tested by scratch wound assays. The rat CRC model was induced by AOM/DSS, in which we verified activity in the Wnt/β-catenin pathway by examining GSK3β phosphorylation. ResultsRNF6 was upregulated in CRC samples and cell lines. Silencing or overexpressing RNF6 in colorectal cancer cells inhibited or promoted, respectively, the proliferation, tumorigenicity, invasion and migration of CRC cells, as well as expression of p-GSK3β, GSK3β and β-catenin. IM-12 reversed the Wnt/β-catenin-activated state change induced by RNF6 silencing and the inhibition of cell proliferation, tumorigenicity, invasion and migration. The same results were observed in vivo in the rat CRC model. ConclusionsOverexpression of RNF6 in CRC increased the GSK3β phosphorylation level, which led to activation of the Wnt/β-catenin pathway and promoted the invasion and migration of CRC cells, suggesting that RNF6 may be a novel target for the treatment of CRC.

Effect of mesenchymal stem cells on cytochrome-c release and inflammation in colon cancer induced by 1,2-dimethylhydrazine in Wistar albino rats.

Colon cancer is one of the most common causes of deaths by cancer worldwide. Stem cells have immunosuppressive properties that promote tumor targeting and circumvent obstacles currently in gene therapy. Bone marrow stem cells are believed to have anticancer potential. The transplantation of mesenchymal stem cells (MSCs), a type of bone marrow stem cells, has been considered a potential therapy for patients with solid tumors due to their capability to enhance the immune response; MSC transplantation has received renewed interest in recent years. The present study aimed to evaluate the antiapoptotic effects of the MSCs on 1,2-dimethylhydrazine (DMH)-induced inflammation in the rat model of colorectal cancer. The rats were randomly allocated into four groups: control, treated with MSCs, induced by DMH, and induced by DMH and treated with MSCs. The MSCs were intra-rectally injected, and DMH was subcutaneously injected at 20 mg/kg body weight once a week for 15 weeks. The administration of MSCs into rats starting from day 0 of the DMH injection was found to enhance the histopathological picture. The MSC treatment resulted in fewer inflammatory cells than in the DMH group. Therefore, our findings suggest that BMCs have antitumor effects by modulating the cellular redox status and down-regulating the pro-inflammatory genes. Thus, BMCs may provide therapeutic value for colon cancer treatment.

Effect of intact oxaliplatin in plasma on a cold allodynia after multiple administrations in colorectal cancer model rats

Oxaliplatin (L-OHP)-induced acute neuropathy is a major factor for influencing treatment compliance in patients receiving chemotherapy for colorectal cancer (CRC). Acute neuropathy is caused by the intact L-OHP affecting the function of transient receptor potential vanilloid 1 (TRPV1) channel. In this study, the effectiveness of the detection of the intact L-OHP and the association with the severity of L-OHP-induced acute neuropathy were investigated using a rat model of CRC. Wistar male rats were prepared as models of CRC by using 1,2-dimethylhydrazine (DMH) and dextran sulfate. Intravenous L-OHP was administered (weekly) to CRC rats for 4 weeks, at doses of 3, 5, or 8 mg/kg, respectively. Pharmacokinetic and tumor distribution profiles of animals with intact L-OHP were observed on days 1 and 22. Cold allodynia was determined as a read-out of acute neuropathy using the acetone test over the 4 weeks. The mean AUC0-∞ values for the intact L-OHP were increased dose-dependently at the three doses. The accumulation of intact L-OHP was confirmed following an increase in L-OHP concentration on day 22. Acute neuropathy was observed from day 2 at all doses and the withdrawal response correlated with AUC (R2 =0.9816). To prevent the onset of L-OHP-induced acute neuropathy, the timely detection of the intact L-OHP is important. These findings could be a basis of the establishment a pharmacokinetic and toxicodynamic model to aid the planning of therapy cycle completion for CRC.

Abstract 15: Hypertension drug Olmesartan medoxomil promotes colonic tumorigenesis in AOM-induced CRC rat model

Abstract Some retrospective studies suggest an inverse risk-association between the use of angiotensin signaling inhibitors and colorectal cancer (CRC). The angiotensin receptor blocker olmesartan medoxomil (OLM) is commonly prescribed for hypertension treatment. Here we sought to determine the chemopreventive efficacy of OLM using the azoxymethane (AOM)-induced CRC rat model. Male and female F344 rats (n=6/gender/group) were randomized and subcutaneously injected with 20 mg/kg of AOM once weekly for two weeks. One week later, AIN76-A diets containing OLM (0 ppm to 480 ppm) were fed to rats. Six weeks after treatment, rats were euthanized and evaluated for toxicity and aberrant crypt foci (ACF) inhibition. OLM-fed rats, particularly at ≥160 ppm, showed signs of toxicity. There was a modest decrease in the total ACFs without any change in multicrypt ACFs in male rats; however in females there was an increase in multicrypt ACFs as compared to the control diet group. For tumor efficacy evaluation, 5-week-old F344 rats were randomized (n=30/gender/group) and CRC was induced as described above. At the adenoma stage (12-weeks after AOM-treatment), rats were administered OLM (0, 20 and 40 ppm) in the diet for 33 weeks, and colonic tumors were evaluated. In the control group, there was a huge disparity in colonic tumor incidence and multiplicity between genders with ~3-fold less tumors in female rats. Surprisingly, colon tumor incidence was significantly increased (3-fold; p&amp;lt;0.0002) in the OLM-treated female rats (77% OLM vs 24% control). Colon tumor multiplicity analysis also showed tumor promoting effects. In the 20 ppm OLM-treated male and female rats, colonic adenocarcinoma multiplicities were increased by ~91% (p&amp;lt;0.01) and ~362% (p&amp;lt;0.0001), respectively, when compared with their respective controls. Although there was no dose response, similar tumor promoting effects were found in 40 ppm OLM-treated rats. To understand male vs female colon tumor disparities and OLM tumor promoting effects, we carried out RNA-Seq analysis of colonic tumors. Reflecting tumor data, gene expression analysis also showed significant differences between male and female rats with respect to type II-interferon, PI3K-AKT, cholesterol, lipid droplet, mucin, IL-3, cell-cycle and nucleotide GPCR signaling pathways. OLM treatment significantly upregulated 586 and 740 genes, and downregulated 648 and 564 genes in male and female rat tumors, respectively. Of the 293 common genes identified, Irx5, Lrrn1, Ly6g6e, Sccpdh, Hoxd12, Igfbp1, Krt81 and DSC3 were upregulated up to 245-fold; and Rfxapl1, Serpinb3a, REg3b, Bnc1 and Ak4 were down-regulated 10 - 200-fold with OLM treatment. In conclusion, chronic administration of OLM did not provide any chemopreventive benefit against colonic tumors in the AOM-induced F344 rat CRC model. Further studies are warranted to assess the risk of colon cancer associated with long-term OLM use, particularly in females. (Supported by NCI HHSN 261201500038I and VA Merit Award) Citation Format: Venkateshwar Madka, Yuting Zhang, Gopal Pathuri, Janani Panneerselvam, Nicole Stratton, Anil Singh, Shizuko Sei, Jennifer Fox, Chinthalapally V. Rao. Hypertension drug Olmesartan medoxomil promotes colonic tumorigenesis in AOM-induced CRC rat model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 15.

Possible correlation between Lactobacillus paracasei X12 intake and tumor characteristics in the rat model of colorectal cancer

Introduction: There are many different therapeutic approaches to control colorectal cancer (CRC) which is recognized as one of the deadliest diseases in the world today. One of the most recent of which is the probiotic interventions to change the gut microbiome. Probiotics can be related to the control of gastrointestinal cancers in a variety of ways. Therefore, the present study aimed to investigate the relationship between supplement use with macroscopic and physiological changes of tumor in 1,2-dimethylhydrazine (DMH) -induced rats. Methods: The male Wistar rats were divided into three groups. Lactobacillus paracasei X12 was administrated (40 weeks) to the DMH-induced rats. DMH injection (30 mg/kg BW) was used for 12 weeks to induce CRC. The "AgNOR method" was applied for the evaluation of cell proliferation. Real-time polymerase chain reaction (PCR) was used to measure the gene expression of apoptotic markers. Results: The findings of this study indicated that L. paracasei X12 intake prevented weight loss caused by CRC (P=001), and probiotic consumption could significantly prevent tumor growth. Additionally, a significant correlation was observed between apoptosis markers and weight of animals, and a strong negative correlation (P=000) between apoptosis parameters and tumor characteristics (incidence, volume, and multiplicity of adenomas). A close association between cell proliferation and tumor characteristics was illuminated as well (P&lt;001). Conclusion: This study revealed a strong correlation between tumor incidence and growth and probiotic intake in CRC. Moreover, it could be believed that cancer prevention is a far more essential and cost-effective way than its cure.

Preventive and Tumor-Suppressive Effects of Lactobacillus Paracasei X12 in Rat Model of Colorectal Cancer.

The paper in hand seeks to evaluate the tumor-suppressive and apoptotic effects of L. paracasei X12 in 1, 2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. The rats were divided into three groups (n = 8-12 per group); L. paracasei X12 was administrated to these animals for forty weeks. The findings of this study indicated that L. paracasei X12 administration prevented severe weight loss in DMH-treated rats. It was also determined that L. paracasei X12 administration could prevent the neoplasia incidence, cell proliferation and it also could suppress the tumors’ growth. Additionally, a significant improvement was observed in apoptosis indexes and cell proliferation in probiotic-treated rats. In conclusion, this study provides insights into the therapeutic potential of L. paracasei X12 with emphasis on the issue that modulation of apoptosis pathway could leave beneficial effects in the prevention and suppression of colorectal cancer (CRC). However, further studies are in support to clarify the mechanisms involved in the tumor-suppressive effect of probiotics.

NIR-II Fluorescence Endoscopy for Targeted Imaging of Colorectal Cancer.

Endoscopy is a clinical gold standard to exam the interior of a hollow organ or body cavity. For the first of time, this study presents the design and construction of a fluorescent endoscopic system that harnesses the power of the second near-infrared window II (NIR-II) fluorescence imaging. An NIR-II fluorescent molecular probe, indocyanine green (ICG) conjugated bevacizumab (Bev-ICG) that targets vascular endothelial growth factor (VEGF), is successfully synthesized and evaluated along with the NIR-II endoscopy imaging system. Simultaneous NIR-II fluorescence and white-light (WL) imaging of VEGF is validated in an orthotopic rat colorectal cancer model. This NIR-II endoscopy system is a generalizable design, and it is compatible with the most of current clinic endoscopies. Similar hardware upgrades are expected to greatly promote the application of NIR-II fluorescent imaging in the clinic.

Assessment of Oxaliplatin-induced Chronic Neuropathy and Anticancer Efficacy Through Pharmacokinetic and Toxicodynamic Evaluation of a Rat Model of Colorectal Cancer.

Oxaliplatin-induced chronic neuropathy is a prominent factor for dose reduction and not completing all cycles of chemotherapy for patients with colorectal cancer (CRC). The aim of the study was to investigate the pharmacokinetics and toxicodynamics of oxaliplatin-induced chronic neuropathy in CRC rats to ensure effective management. A rat model of CRC was developed using 1,2-Dimethylhydrazine and dextran sulfate. Oxaliplatin (L-OHP) was administered intravenously to CRC rats every week. The pharmacokinetic profiles and tumor distribution of L-OHP and chronic neuropathies were investigated for over four weeks. The mean values of the area under the concentration-time curve for L-OHP showed a dose-dependent increase. Chronic neuropathy occurred from Day 14 in the 8 mg/kg group and Day 19 in the 3 and 5 mg/kg groups. These results provide preliminary information for the development of a pharmacokinetic and toxicodynamic model of L-OHP for CRC therapy cycles.

Design, optimization and validation of genes commonly used in expression studies on DMH/AOM rat colon carcinogenesis model.

Colorectal cancer (CRC), also known as colon cancer, is the third most common form of cancer worldwide in men and the second in women and is characterized by several genetic alterations, among them the expression of several genes. 1,2-dimethylhydrazine (DMH) and its metabolite azoxymethane (AOM) are procarcinogens commonly used to induce colon cancer in rats (DMH/AOM rat model). This rat model has been used to study changes in mRNA expression in genes involved in this pathological condition. However, a lack of proper detailed PCR primer design in the literature limits the reproducibility of the published data. The present study aims to design, optimize and validate the qPCR, in accordance with the MIQE (Minimum Information for Publication of Quantitative Real-Time PCR Experiments) guidelines, for seventeen genes commonly used in the DMH/AOM rat model of CRC (Apc, Aurka, Bax, Bcl2, β-catenin, Ccnd1, Cdkn1a, Cox2, Gsk3beta, IL-33, iNOs, Nrf2, p53, RelA, Smad4, Tnfα and Vegfa) and two reference genes (Actb or β-actin and B2m). The specificity of all primer pairs was empirically validated on agarose gel, and furthermore, the melting curve inspection was checked as was their efficiency (%) ranging from 90 to 110 with a correlation coefficient of r2 > 0.980. Finally, a pilot study was performed to compare the robustness of two candidate reference genes.

Phytic acid improves intestinal mucosal barrier damage and reduces serum levels of proinflammatory cytokines in a 1,2-dimethylhydrazine-induced rat colorectal cancer model.

Phytic acid (PA) has been demonstrated to have a potent anticarcinogenic activity against colorectal cancer (CRC). Defects of the intestinal mucosal barrier and inflammation processes are involved in the development and progression of CRC. In the present study, we evaluated the effect of PA on the intestinal mucosal barrier and proinflammatory cytokines. After a 1-week acclimatisation period, sixty Wistar male rats were divided into the following five groups, with twelve rats per group: the control group (CG), model group (MG), low-PA-dose group (0·25 g/kg per d), middle-PA-dose group (0·5 g/kg per d), and high-PA-dose group (1 g/kg per d). 1,2-Dimethylhydrazine (DMH) at a dosage of 30 mg/kg of body weight was injected weekly to induce CRC for 18 weeks. We examined the expression of genes related to the intestinal mucosal barrier in the model. The results demonstrated that tumour incidence was decreased following PA treatment. The mRNA and protein expression of mucin 2 (MUC2), trefoil factor 3 (TFF3) and E-cadherin in the MG were significantly lower than those in the CG (P<0·05). The mRNA and protein expression of claudin-1 in the MG were significantly higher than those in the CG (P<0·05). PA elevated the mRNA and protein expression of MUC2, TFF3 and E-cadherin, and diminished the mRNA and protein expression of claudin-1. Furthermore, PA decreased serum levels of proinflammatory cytokines, which included TNF-α, IL-1β and IL-6. In conclusion, this study suggests that PA has favourable effects on the intestinal mucosal barrier and may reduce serum proinflammatory cytokine levels.

Evaluation of a Tumor-Targeting, Near-Infrared Fluorescent Peptide for Early Detection and Endoscopic Resection of Polyps in a Rat Model of Colorectal Cancer.

The goal of these studies was to use a tumor-targeting, near-infrared (NIR) fluorescent peptide to evaluate early detection and to guide surgical removal of polyps in a genetically engineered rat model of spontaneous colorectal cancer. This peptide, LS301, was conjugated to Cy7.5 and applied topically to the colon of adenoma-bearing Pirc rats. Ten minutes after administration, rats underwent targeted NIR laser colonoscopy. Rats were also evaluated by white light colonoscopy and narrow-band imaging, for comparison to the NIR technique. Unlike white light and narrow-band colonoscopy, NIR imaging detected unexpected flat lesions in young Pirc rats. NIR imaging was also used to assess resection margins after electrocauterization of polyps. Tumor margins remained negative at 5 weeks postsurgery, demonstrating successful polypectomy. The present studies show that NIR-targeted colonoscopy is an attractive strategy to improve screening for and resection of colorectal neoplasia.