Anti‑tumor effects of an aqueous extract of Ecklonia cava in BALB/cKorl syngeneic mice using colon carcinoma CT26 cells

Ecklonia cava (E. cava) is well known as one of edible alga that contains various unique polyphenols. The anti‑tumor activity of an aqueous extract of E. cava (AEC) against colon carcinoma was evaluated by analyzing the alterations in tumor growth, histopathological structure and molecular mechanisms in CT26 tumor‑bearing BALB/cKorl syngeneic mice after administrating AEC for five weeks. AEC contained high total phenolic contents and demonstrated significant scavenging activity against 2,2‑diphenyl‑1‑picrylhydrazyl radicals. Marked anti‑tumor effects were demonstrated in the AEC‑treated CT26 cells. In the in vivo syngeneic model, the AEC treatment decreased the volume and weight of CT26 tumors, and expanded the necrotic region in the hematoxylin and eosin stained tumor sections. The inhibitory effects of AEC on tumor growth were reflected by the increased level of apoptotic proteins, inhibition of cell proliferation, suppression of metastasis ability and increase in tumor‑suppressing activity in CT26 tumor‑bearing BALB/cKorl syngeneic mice. The potential function of phlorotannin (PT), one of the primary active compounds in AEC, was demonstrated by the increased cytotoxicity, apoptosis and suppression of cell proliferation in PT‑treated CT26 cells. Overall, the results of the present study provide novel scientific evidence that AEC can suppress the growth of CT26 colon cancer by activating apoptosis, suppressing cell proliferation, inhibiting cell migration and enhancing the tumor‑suppressing activity.

Abstract 6217: Inhibiting ataxia-telangiectasia mutated and RAD3-related (ATR) by BAY 1895344 overcomes chemoresistance to oxaliplatin and promotes synergistic anti-tumor effect in pancreatic cancer

Pancreatic Ductal Adenocarcinoma (PDAC) is a highly aggressive disease with a poor prognosis and a limited response to most of the treatments. Despite a platinum-based drug such as oxaliplatin or cisplatin is one of the most effective chemotherapy drugs for PDAC, resistance to it is a major limiting factor in PDAC treatment, indicating an urgent need for new approaches. Recently, targeting major DNA damage response (DDR) regulators such as ATM (Ataxia-telangiectasia mutated) or ATR (Ataxia telangiectasia mutated and Rad3-related) kinase has shown therapeutic potential in cancer treatment. This shows that it may be possible to enhance the responsiveness of platinum medicines via a DDR inhibition strategy. The most recently developed ATR inhibitor with the greatest potency, BAY 1895344, showed an anti-proliferative effect in clinical trials. Here, we aimed to evaluate the effect of ATR inhibition using BAY 1895344 on responsiveness to oxaliplatin in pancreatic cancer, for the first time. CFPAC-1 and Capan-2 are selected among six kinds of pancreatic cancer cell lines as oxaliplatin-sensitive and -resistant cells, respectively. According to BRAID analysis, combining the BAY 1895344 and oxaliplatin resulted in strong synergistic effects in both cell lines, particularly in Capan-2. The synergism is also confirmed in all four organoids derived from PDAC patients. We found that p-Chk1, coordinating DDR and cell cycle checkpoint, was considerably suppressed by the combined treatments, which was associated with elevated γ-H2AX intensity, cell cycle arrest and apoptosis. Moreover, we investigated the in vivo synergistic anti-tumor efficacy of combination therapy using a tumor-bearing nude mice model with CFPAC-1 and Capan-2 cells, demonstrating a substantial reduction of tumor growth in combination therapy when compared to single treatment. In conclusion, ATR inhibition enhanced the anticancer effect of oxaliplatin, and this combined therapeutic strategy may be effective in overcoming chemo-resistance in PDAC. (This study is supported by National Cancer Center, Republic of Korea (No. 2212470, 2010330))

Citation Format: Hye Won Shon, Jung Won Chun, Jeong Eun Gong, Mi Rim Lee, Yu-Sun Lee, Sumin Kang, Sunshin Kim, Sang Myung Woo, In Rae Cho, Woo Hyun Paik, Woo Jin Lee, Ji Kon Ryu, Yong-Tae Kim, Sang Hyub Lee, Yun-Hee Kim. Inhibiting ataxia-telangiectasia mutated and RAD3-related (ATR) by BAY 1895344 overcomes chemoresistance to oxaliplatin and promotes synergistic anti-tumor effect in pancreatic cancer [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 6217.

Abstract 161: Patient-derived organoids (PDOs) hub of National Cancer Center, Korea: pre-clinical model for drug screening

Purpose Cancer is one of the leading causes of death worldwide. Patient-derived tumor cells can serve as a powerful resource for studying pathophysiologic mechanisms and developing robust strategies for precision medicine. To address this problem, we launched the patient-derived organoids (PDOs) Hub to establish a comprehensive model of various tumor organoids from pancreatic, biliary tract, liver, colorectal, breast, gastric, ovarian, and oral cancers, with matching clinical data and molecular characteristics.

Methods All specimens were collected from histologically confirmed cancer patients at the National Cancer Center. Samples obtained from surgery, biopsy, or body fluid (malignant ascites or pleural effusion) were collected for ex vivo culture of tumor cells. PDOs were managed according to our standard operating procedure (SOP), which included specimen delivery process, separation of cells from tissues, criteria for subculture, quality control (QC), production of genomic and histologic data, and the 384-well-based drug response evaluation system. Organoids were considered to be successfully cultured when they were maintained for five or more passages.

Results A total of 263 PDOs were established from various cancer types, including oral cancer (N = 89), pancreatic cancer (N = 48), ovarian cancer (N = 32), breast cancer (N = 30), biliary tract cancer (N = 29), hepatocellular carcinoma (N = 17), gallbladder cancer (N = 8), gastric cancer (N = 7) and colorectal cancer (N = 3). PDOs broadly recapitulated the histologic and genetic characteristics of the patient’s tumor. These organoids available for long-term culture were cryopreserved, and a total of 2986 stocks have been accumulated. Drug screening tests were performed with 60 PDOs (pancreatic cancer, N = 36; breast cancer, N = 15; ovarian cancer, N = 6; gastric cancer, N = 3) using selected agents among the 47 drugs for each type of cancer. Profiles of cytotoxic agents were well correlated with the patient’s clinical responses to the matched drugs and tested investigational agents also showed promising antitumor activity.

Conclusions We have established a model of several human cancer organoids. This will serve as the platform that can recapitulate the physiology and drug response profiles of human cancer and pave the way for screening innovative drugs, identifying novel targets, and stratifying patients for pertinent therapeutic options.

(This work was supported by National Research Foundation of Korea grant, funded by the Korean government (MSIT) (No. 2020M3A9A5036362))

Citation Format: Yebeen Yu, Mi Rim Lee, Wonyoung Choi, Sumin Kang, Jeong Eun Gong, Soobeen Heo, Hye Ju Park, Sang Myung Woo, So-Youn Jung, Sung Weon Choi, Jong-Ho Lee, Myong Cheol Lim, Ji Yeon Baek, Bo Hyun Kim, Ji Hoon Kim, Yuri Cho, Sang-Jae Park, Yun-Hee Kim, Sun-Young Kong. Patient-derived organoids (PDOs) hub of National Cancer Center, Korea: pre-clinical model for drug screening [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 161.

Comparison of immunophenotypes between Rag2 knockout mice derived from two different sources

BACKGROUND

Recombination activating gene2 (Rag2) knockout (KO) mice are used widely in various research fields, including vaccine development, transplantation studies, and hematopoiesis research, but few studies have compared their phenotypes. This study examined whether there were differences in the immunophenotypes between Rag2 KO mice derived from different sources. In particular, the changes in the organ weight, histological structure, and subpopulation of T and B cells were compared in the spleen and thymus of C57BL/6-Rag2^em1hwl/Korl (Rag2/Korl KO) and B6.Cg-Rag2^tm1.1Cgn/J (Rag2/J KO) mice.

RESULTS

The weight of the spleen and thymus similarly decreased in the Rag2/Korl and Rag2/J KO mice compared to their wild type (WT) mice, even though the other organs were kept at the same weight. A slight difference between the Rag2/Korl and Rag2/J KO group were detected in the number of white blood cells (WBC), lymphocytes (LYM), red cell distribution width (RDW), and platelets (PLT). In addition, the white pulp of the spleen and the cortex region of the thymus decreased in both Rag2 KO mice compared to WT mice. On the other hand, significant differences in the number of CD8⁺ T and B cell subpopulations between WT and Rag2 KO mice were observed between Rag2/Korl and Rag2/J KO group, while the CD4⁺ T subpopulation was maintained similarly in both groups.

CONCLUSIONS

These results suggest that Rag2/Korl and Rag2/J KO mice exhibit similar immunophenotypes in the spleen and thymus except for the differences in the number of CD8⁺ T and B cell subpopulations.

Novel role of Dipterocarpus tuberculatus as a stimulator of focal cell adhesion through the regulation of MLC2/FAK/Akt signaling pathway

To investigate a novel function of Dipterocarpus tuberculatus on focal cell adhesion stimulation, alterations to the regulation of focal cell adhesion-related factors were analyzed in NHDF cells and a calvarial defect rat model after treatment with methanol extracts of D. tuberculatus (MED). MED contained gallic acid, caffeic acid, ellagic acid, and naringenin in high concentrations. The proliferation activity, focal cell adhesion ability, adhesion receptors-mediated signaling pathway in NHDF cells were increased by MED. Also, a dense adhered tissue layer and adherent cells on MED-coated titanium plate (MEDTiP) surfaces were detected during regeneration of calvarial bone. The results of the present study provide novel evidence that MED may stimulate focal cell adhesion in NHDF cells and a calvarial defect rat model.

Comparison of cisplatin-induced anti-tumor response in CT26 syngeneic tumors of three BALB/c substrains

Background

To determine whether the background of BALB/c substrains affects the response to anti-tumor drugs, we measured for alterations in tumor growth, histopathological structure of the tumor, and expressions of tumor-related proteins in three BALB/c substrains derived from different sources (BALB/cKorl, BALB/cA and BALB/cB), after exposure to varying concentrations of cisplatin (0.1, 1 and 5 mg/kg).

Results

Cisplatin treatment induced similar responses for body and organ weights, serum analyzing factors, and blood analyzing factors in all BALB/c substrains with CT26 syngeneic tumor. Few differences were detected in the volume and histopathological structure of the CT26 tumor. Growth inhibition of CT26 tumors after exposure to cisplatin was greater in the BALB/cB substrain than BALB/cKorl and BALB/cA substrains, and a similar pattern was observed in the histopathological structure of tumors. However, the expression levels of other tumor-related factors, including Ki67, p27, p53, Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), caspase-3 (Cas-3), matrix metallopeptidase 2 (MMP2) and vascular endothelial growth factor (VEGF) proteins, were constantly maintained in the tumors of all three substrains after cisplatin treatment. A similar decrease pattern was observed for the expressions of inflammatory cytokines, including interleukin (IL)-1β, IL-6 and IL-10, in the CT26 tumors of the three BALB/c substrains.

Conclusions

Taken together, results of the present study indicate that the genetic background of the three BALB/c substrains has no major effect on the therapeutic responsiveness of cisplatin, except growth and histopathology of the CT26 syngeneic tumor.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42826-021-00110-3.

Inflammatory response in the mid colon of ICR mice treated with polystyrene microplastics for two weeks

Background

The oral administration of polystyrene-microplastics (PS-MPs) causes chronic constipation of ICR mice, but there are no reports on their effects on the inflammatory response in the colon. To determine if the oral administration of MPs causes inflammation in the colon, the changes in the apoptosis-associated speck like protein containing a caspase recruitment domain (ASC)-inflammasome pathway, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway, and inflammatory cytokine expression were evaluated in the mid colon of ICR mice treated with 0.5 μm size PS-MPs for two weeks.

Results

The thicknesses of the mucosa, muscle, flat luminal surface, and crypt layer were decreased significantly (p < 0.01) in the mid colon of the MPs treated group compared to the Vehicle treated group. On the other hand, a remarkable increase in the expression levels of NOD-like receptor pyrin domain-containing protein (NLRP) 3, ASC, and Cleaved Caspase (Cas)-1 protein was observed in the MPs treated group. In addition, similar increasing pattern in the levels of p-NF-κB and phospho-inhibitory subunit of NF-κB (p-IkB) α protein was detected. Four inflammatory cytokines, including NF-κB, interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β, showed an increased expression level after the MPs treatment.

Conclusions

Therefore, the present study suggests that PS-MPs can be a novel cause of an inflammatory response in the mid colon of ICR mice.

Dysbiosis of Fecal Microbiota From Complement 3 Knockout Mice With Constipation Phenotypes Contributes to Development of Defecation Delay

Significant phenotypes for constipation were detected in complement 3 (C3) knockout (KO) mice, although no research has been conducted on an association with alteration of gut microbiota. To investigate the effects of dysbiosis on fecal microbiota from C3 KO mice with constipation, the composition of fecal microbiota was characterized in mid-colons of 16-week-old C3 KO mice, and their function for defecation delay development was examined after fecal microbiota transplantation (FMT) of C3 KO mice. Some significant alterations in constipation phenotypes, including stool parameters and histopathological structure, were detected in 16-week-old C3 KO mice compared to those of wild-type (WT) mice. Fecal microbiota of C3 KO mice exhibited decreases in Anaerocolumna, Caecibacterium, Christensenella, Kineothrix, and Oscillibacter populations and increases in Prevotellamassilia, Reuthenibacterium, Prevotella, Eubacterium, Culturomica, Bacteroides, and Muribaculum populations. In FMT study, key stool parameters, including weight and water content, were remarkably declined in a transplanted KO (KFMT) group of antibiotics-induced depletion of microbiota (AiDM)-WT and AiDM-KO mice, and a similar change was observed in fecal morphology. However, intestine length decreased in only the KFMT group of AiDM-WT mice compared with that of AiDM-KO mice. The mucosal layer and muscle thickness were commonly decreased in the KFMT group of AiDM-WT and AiDM-KO mice, and significant alterations in the crypt structure of Lieberkuhn and molecular regulators, including AQP8, C-kit, and 5-HT, were observed in the same group. Taken together, results of the present study indicate that dysbiosis of fecal microbiota from C3 KO mice with constipation phenotypes has a key role in the induction and regulation of defecation delay.

Loperamide-induced Constipation activates Inflammatory Signaling Pathways in the Transverse Colon of SD rats via Complement C3 and its receptors

BACKGROUND

Complement component 3 (C3) receptors play an important role as an inflammatory mediator in the innate immune system, although their mechanism was not well studied during constipation.

OBJECTIVE

The aim of this study is to investigate the regulatory role of C3 and its receptors' downstream signaling during constipation.

METHODS

Alterations in the C3, C3a receptor (C3aR), and C3b receptor (C3bR) expressions, PI3K/AKT pathway, RhoA/MLC pathway, MAP kinase pathway, and inflammatory cytokine expressions were measured in the transverse colon of loperamide (Lop) treated SD rats.

RESULTS

Lop treatment successfully induced constipation phenotypes, including decreased stool parameters and histological structure alterations. The expression levels of C3 were significantly increased, whereas expressions of C3aR and C3bR were observed to decrease during Lop-induced constipation. Moreover, significant upregulation was observed in the phosphorylation levels of PI3K, AKT, and GSK3 in transverse colons of Lop treated SD rats. The expression of RhoA and phosphorylation of MLC were also enhanced in the Lop treated group. Furthermore, a similar pattern was detected in the MAP kinase pathway and inflammatory cytokine expressions. Subsequent to Lop treatment, the phosphorylation of ERK and p38, as well as the mRNA levels of NF-κB, TNF-α, IL-6 and IL-1α were remarkably increased in the transverse colon.

CONCLUSION

These results indicate that Lop-induced constipation is tightly linked to the downregulation of C3aR and C3bR expressions and upregulation of the C3, C3Rs downstream signaling pathway, including PI3K/AKT, RhoA/MLC, and MAP kinase pathways as well as inflammatory cytokine expressions in the transverse colon of SD rats.</P>.

Antioxidant activity and laxative effects of tannin-enriched extract of Ecklonia cava in loperamide-induced constipation of SD rats

To investigate the role of tannin-enriched extracts of Ecklonia cava (TEE) on the regulation of oxidative balance and laxative activity in chronic constipation, we investigated alterations after exposure to TEE, on constipation phenotypes, muscarinic cholinergic regulation, and oxidative stress responses in the transverse colons of SD rats with loperamide (Lop)-induced constipation. This extract contains high levels of total condensed tannin content (326.5 mg/g), and exhibited high inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. TEE treatment induced significant improvements in reactive oxygen species (ROS) production, superoxide dismutase (SOD) expression and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation in primary smooth muscles of rat intestine cells (pRISMCs) and transverse colon of constipation model. Also, Lop+TEE treated groups showed alleviated outcomes for the following: most stool parameters, gastrointestinal transit, and intestine length were remarkably recovered; a similar recovery pattern was observed in the histopathological structure, mucin secretion, water channel expression and gastrointestinal hormones secretion in the transverse colon; expressions of muscarinic acetylcholine receptors M2/M3 (mAChR M2/M3) and their mediators on muscarinic cholinergic regulation were significantly recovered. Taken together, these results provide the first evidence that TEE stimulates oxidative stress modulation and muscarinic cholinergic regulation when exerting its laxative effects in chronic constipation models.

Comparison of response to LPS-induced sepsis in three DBA/2 stocks derived from different sources

Sepsis, one of the most fatal diseases in the world, is known to culminate in multiple organ failure due to an uncontrolled inflammatory response. Hence, the use of animal models in sepsis research is very important to study complex immune responses. The current study was undertaken to compare commercial stocks with KFDA stocks of DBA/2 mice as an animal model for sepsis study. To compare responses of DBA/2 mice to lipopolysaccharides (LPS)-induced sepsis, we measured altered characteristics of various factors associated with sepsis, including survival curves, organ failure and inflammatory response, in DBA/2Korl stock and two commercial stocks (DBA/2A and DBA/2B). Survival rates after LPS exposure were similar for DBA/2Korl and DBA/2B; however, for times over 20 h, survival rates were reduced and concentration dependent in DBA/2A. In order to evaluate multiple organ failure caused by sepsis, H&E stains were evaluated for liver and spleen tissues obtained in the early (2 h) and later (20 h) stages after exposure to LPS; no significant differences were observed between the three stocks. mRNA and protein levels of proinflammatory cytokines were assessed for evaluating inflammatory reactions, and were found to increase in a dose-dependent manner in most DBA/2 mice after LPS treatment. However, no changes were observed in the mRNA levels of proinflammatory cytokines at 20 h after LPS exposure in the DBA/2A stock. The induction of inflammation-mediated factors by LPS exposure did not induce alterations in the mRNA levels of COX-2 and iNOS in all three DBA/2 stocks. Our results indicate that response of DBA/2Korl to LPS-induced sepsis is similar to the two commercial DBA/2 stocks, thus representing its potential as a useful biological resource established in Korea.

Anti-inflammatory effects of Capparis ecuadorica extract in phthalic-anhydride-induced atopic dermatitis of IL-4/Luc/CNS-1 transgenic mice

CONTEXT

The natural products derived from Capparis ecuadorica H.H. Iltis (Capparaceae) could have great potential for anti-inflammation since they inhibited the inflammatory response in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.

OBJECT

This study investigated the anti-inflammatory effects and related mechanism of methanol extract of C. ecuadorica leaves (MCE) during atopic dermatitis (AD) responses.

MATERIALS AND METHODS

Alterations in the phenotypical markers for AD, luciferase signal, iNOS-mediated COX-2 induction pathway, and inflammasome activation were analysed in non-Tg (n = 5) and 15% phthalic anhydride (PA) treated IL-4/Luc/CNS-1 transgenic (Tg) HR1 mice (n = 5 per group), subsequent to treatment with acetone-olive oil (AOO), vehicle (DMSO) and two dose MCE (20 and 40 mg/kg) three times a week for 4 weeks.

RESULTS

MCE treatment reduced the intracellular ROS level (48.2%), NO concentration (7.1 mmol/L) and inflammatory cytokine expressions (39.1%) in the LPS-stimulated RAW264.7 cells. A significant decrease was detected for ear thickness (16.9%), weight of lymph node (0.7 mg), IgE concentration (1.9 µg/mL), and epidermal thickness (31.8%) of the PA + MCE treated Tg mice. MCE treatment induced the decrease of luciferase signal derived from the IL-4 promoter and the recovery of the IL-4 downstream regulator cytokines. PA + MCE treated Tg mice showed decreasing infiltration of mast cells (42.5%), iNOS-mediated COX-2 induction pathway, MAPK signalling pathway and inflammasome activation in the ear tissue.

CONCLUSIONS

These findings provide the first evidence that MCE may have great potential to suppress chemical-induced skin inflammation through the suppression of IL-4 cytokine and the iNOS-mediated COX-2 induction pathway, and activation of inflammasome.

Influence of three BALB/c substrain backgrounds on the skin tumor induction efficacy to DMBA and TPA cotreatment

Differences in responsiveness of BALB/c substrains have been investigated in various fields, including diabetes induction, corpus callosum deficiency, virus-induced demyelinating disease, aggressive behavior and osteonecrosis. However, induction efficacy of skin tumor remains untried. We therefore investigated the influence of BALB/c substrain backgrounds on the skin tumor induction efficacy in response to DMBA (7,12-Dimethylbenz[a]anthracene) and TPA (12-O-tetradecanoylphorbol-13-acetate) cotreatment. Alterations in the levels of tumor growth related factors, histopathological structure, and the expression to tumor related proteins were measured in three BALB/c substrains (BALB/cKorl, BALB/cA and BALB/cB) after exposure to DMBA (25 μg/kg) and three different doses of TPA (2, 4 and 8 μg/kg). The average number and induction efficacy of tumors in response to DMBA+TPA treatment were significantly greater in the BALB/cKorl substrain than in BALB/cA and BALB/cB. However, cotreatment with DMBA+TPA induced similar responses for body and organ weights of all three substrains. Few differences were detected in the serum analyzing factors, while similar responsiveness was observed for blood analyzing factors after DMBA+TPA treatment. Furthermore, the three BALB/c substrains exhibited similar patterns in their histopathological structure in DMBA+TPA-induced tumors. The expression levels of apoptotic proteins and tumor related proteins were constantly maintained in all three BALB/c substrains treated with DMBA+TPA. In addition, the responsiveness to cisplatin treatment was overall very similar in the three BALB/c substrains with DMBA+TPA-induced tumors. Taken together, these results indicate that genetic background of the three BALB/c substrains does not have a major effect on the DMBA+TPA-induced skin carcinogenesis and therapeutic responsiveness of cisplatin, except induction efficacy.