Human Colorectal HCT116 Cells Research Articles

Synthesis and evaluation of chalcone analogues containing a 4-oxoquinazolin-2-yl group as potential anti-tumor agents

The chalcone motif can be found in many molecules that contribute to essential biological processes, and many chalcone-containing compounds exhibit potent anti-cancer activity. Here, we synthesized two series of chalcone analogues (3a−s and 6a−s) based on substituting the chalcone B-ring or A-ring with a 4-oxoquinazolin-2-yl group, and then evaluated them for cytotoxic activity in human colorectal HCT-116 and breast cancer MCF-7 cell lines. Compounds 3a−s (in which a 4-oxoquinazolin-2-yl group functioned as the B-ring) were markedly more cytotoxic than compounds 6a−s (in which 4-oxoquinazolin-2-yl group functioned as the A-ring), based on their IC50 values to inhibit proliferation. Compound 3f was found as the most potent among 38 analogues and the mechanism of its cytotoxicity was investigated. Flow cytometry indicated that HCT-116 cells treated with compound 3f resulted in a dose-dependent accumulation of cells in the sub-G1 phase, which is representative of apoptotic cells. Subsequent assays (including Annexin V-FITC/PI, AO-EB, MitoSOX™ Red and JC-1 staining) confirmed that 3f exposure induced apoptosis in HCT-116 cells. Immunoblotting analysis indicated that cellular exposure to 3f increased the cleavage of PARP1 and caspases 3, 7, and 9. Taken together, this novel chalcone analogue has a cytotoxic effect on cultured cancer cell-lines that is likely mediated by inducing apoptosis via the mitochondrial death pathway.

The impact of p53 function on the metabolic activation of the carcinogenic air pollutant 3-nitrobenzanthrone and its metabolites 3-aminobenzanthrone and N-hydroxy-3-aminobenzanthrone in human cells.

The tumour suppressor p53, encoded by TP53, is a key player in a wide network of signalling pathways. We investigated its role in the bioactivation of the environmental carcinogen 3-nitrobenzanthrone (3-NBA)found in diesel exhaust and its metabolites 3-aminobenzanthrone (3-ABA) and N-hydroxy-3-aminobenzanthrone (N-OH-3-ABA) in a panel of isogenic human colorectal HCT116 cells differing only with respect to their TP53 status [i.e. TP53(+/+), TP53(+/−), TP53(−/−), TP53(R248W/+) or TP53(R248W/−)]. As a measure of metabolic competence, DNA adduct formation was determined using 32P-postlabelling. Wild-type (WT) p53 did not affect the bioactivation of 3-NBA; no difference in DNA adduct formation was observed in TP53(+/+), TP53(+/−) and TP53(−/−) cells. Bioactivation of both metabolites 3-ABA and N-OH-3-ABA on the other hand was WT-TP53 dependent. Lower 3-ABA- and N-OH-3-ABA-DNA adduct levels were found in TP53(+/−) and TP53(−/−) cells compared to TP53(+/+) cells, and p53’s impact was attributed to differences in cytochrome P450 (CYP) 1A1 expression for 3-ABA whereas for N-OH-3-ABA, an impact of this tumour suppressor on sulphotransferase (SULT) 1A1/3 expression was detected. Mutant R248W-p53 protein function was similar to or exceeded the ability of WT-p53 in activating 3-NBA and its metabolites, measured as DNA adducts. However, identification of the xenobiotic-metabolising enzyme(s) (XMEs), through which mutant-p53 regulates these responses, proved difficult to decipher. For example, although both mutant cell lines exhibited higher CYP1A1 induction after 3-NBA treatment compared to TP53(+/+) cells, 3-NBA-derived DNA adduct levels were only higher in TP53(R248W/−) cells but not in TP53(R248W/+) cells. Our results show that p53’s influence on carcinogen activation depends on the agent studied and thereby on the XMEs that mediate the bioactivation of that particular compound. The phenomenon of p53 regulating CYP1A1 expression in human cells is consistent with other recent findings; however, this is the first study highlighting the impact of p53 on sulphotransferase-mediated (i.e. SULT1A1) carcinogen metabolism in human cells.

Zebrafish embryonic development-interfering macrolides from Streptomyces californicus impact growth and mitochondrial function in human colorectal cancer cells

Abstract Microorganisms are now recognized as a keysource of medicine. In this study, we aim to identify and characterize target-specific inhibitors from actinobacteria using zebrafish embryo developmental defect as readouts. From our preliminary screen, we evaluated 176 Malaysian actinobacteria extracts and from these, 15 extracts (8.52%) were observed to be toxic to embryos at 20 μg/mL at 72-h post fertilization (hpf). Detailed characterization of these 15 toxic hits uncovered one extract derived from Streptomyces californicus TY004-069 that arrested zebrafish embryonic development at 4–6 hpf after 24 h treatment, a phenotype indicative potentially targeting mitochondrial activity. Subsequent validation on one of the three isolated compounds from this extract, dimeric dinactin (DD) revealed its ability to disrupt mitochondrial membrane potential (MMP) in human colorectal HCT116 and HT29 cancer cells in a dose-dependent manner and impacting cell proliferation through a cell cycle G1 block. Overall, using zebrafish phenotypic assay, we identified a potential mitochondrial function inhibitor from actinobacteria that warrants further detailed analysis and also demonstrated that macrolides may hold promise as therapeutic molecules for human diseases including cancer.

New chalcone derivative exhibits antiproliferative potential by inducing G2/M cell cycle arrest, mitochondrial-mediated apoptosis and modulation of MAPK signalling pathway

In the present study, we investigated antiproliferative activity of seven newly synthesized chalcone derivatives. Among tested compounds, (2 E)-3-(acridin-9-yl)-1-(2,6-dimethoxyphenyl)prop-2-en-1-one (1C) was the most potent with IC50 = 4.1 μmol/L in human colorectal HCT116 cells and was selected for further studies. Inhibition of cell proliferation was associated with cell cycle arrest in G2/M phase and dysregulation of α, α1 and β5 tubulins. Moreover, 1C caused disruption of the mitochondrial membrane potential and increased number of cells with sub G0/G1 DNA content which is considered as marker of apoptosis. Apoptosis was confirmed by annexin V/PI and AO/PI staining. Furthermore, we found increased concentration of cytochrome c, Smac/Diablo and increased caspase-3 and caspase-9 activity, cleavage of PARP as well as activation of DNA repair mechanisms in 1C-treated HCT116 cancer cells. Moreover this chalcone derivative up-regulated proapoptotic Bax expression and down-regulated antiapoptotic Bcl-2 and Bcl-xL expression. Additionally, 1C treatment led to modulation of MAPKs and Akt signalling pathways.In conclusion, our data showed ability of 1C to suppress cancel cell growth and provide the rationale for further in vivo study.

Resveratrol analogue, (E)-N-(2-(4-methoxystyryl) phenyl) furan-2-carboxamide induces G2/M cell cycle arrest through the activation of p53-p21CIP1/WAF1 in human colorectal HCT116 cells.

Resveratrol, a naturally occurring polyphenolic antioxidant, is a potential chemoprophylactic agent for various cancers, including colorectal cancer. Although emerging evidence continually suggests that a number of resveratrol derivatives may be better cancer chemopreventive candidates than resveratrol, studies on the mechanism of action of these derivatives are limited. This is the first study which investigates the mechanism underlying the cytotoxic effect of a synthesized resveratrol analogue, (E)-N-(2-(4-methoxystyryl) phenyl) furan-2-carboxamide (CS) on colorectal cancer. Previously, our group reported a series of synthesized resveratrol analogues, which showed cytotoxicity against a panel of cancer cell lines, in particular on colon cancer cells. In this study, we further discovered that CS also exerts a potent suppressive effect on HCT116 colorectal cancer cells. In contrast, normal colon cells (CCD-112 Con) were not sensitive to CS up to 72h post treatment. CS caused cytotoxicity in HCT116 cells through several apoptotic events including activation of the Fas death receptor, FADD, caspase 8, caspase 3, caspase 9, and cleaved PARP, which occurred alongside cell cycle arrest from the up-regulation of p53 and p21. The results show that CS causes apoptosis via the activation of an extrinsic pathway leading to caspase activation and cell cycle arrest from activated p53. These findings suggest that CS may be a potential candidate for development as an anti-tumor agent in the future.

Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells.

The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis, Lactococcus. lactis subsp. Cremoris, Lactococcus. Lactis subsp. Lactis biovar diacetylactis, Lactobacillus plantarum, Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei. In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma) increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

The impact of chemotherapeutic drugs on the CYP1A1-catalysed metabolism of the environmental carcinogen benzo[a]pyrene: Effects in human colorectal HCT116 TP53(+/+), TP53(+/−) and TP53(−/−) cells

Polycyclic aromatic hydrocarbons such as benzo[a]pyrene (BaP) can induce cytochrome P450 1A1 (CYP1A1) via a p53-dependent mechanism. The effect of different p53-activating chemotherapeutic drugs on CYP1A1 expression, and the resultant effect on BaP metabolism, was investigated in a panel of isogenic human colorectal HCT116 cells with differing TP53 status. Cells that were TP53(+/+), TP53(+/–) or TP53(–/–) were treated for up to 48 h with 60 μM cisplatin, 50 μM etoposide or 5 μM ellipticine, each of which caused high p53 induction at moderate cytotoxicity (60–80% cell viability). We found that etoposide and ellipticine induced CYP1A1 in TP53(+/+) cells but not in TP53(–/–) cells, demonstrating that the mechanism of CYP1A1 induction is p53-dependent; cisplatin had no such effect. Co-incubation experiments with the drugs and 2.5 μM BaP showed that: (i) etoposide increased CYP1A1 expression in TP53(+/+) cells, and to a lesser extent in TP53(–/–) cells, compared to cells treated with BaP alone; (ii) ellipticine decreased CYP1A1 expression in TP53(+/+) cells in BaP co-incubations; and (iii) cisplatin did not affect BaP-mediated CYP1A1 expression. Further, whereas cisplatin and etoposide had virtually no influence on CYP1A1-catalysed BaP metabolism, ellipticine treatment strongly inhibited BaP bioactivation. Our results indicate that the underlying mechanisms whereby etoposide and ellipticine regulate CYP1A1 expression must be different and may not be linked to p53 activation alone. These results could be relevant for smokers, who are exposed to increased levels of BaP, when prescribing chemotherapeutic drugs. Beside gene-environment interactions, more considerations should be given to potential drug-environment interactions during chemotherapy.

Effect of AICAR and 5-Fluorouracil on X-ray Repair, Cross-Complementing Group 1 Expression, and Consequent Cytotoxicity Regulation in Human HCT-116 Colorectal Cancer Cells.

Colorectal cancer (CRC) is one of the leading causes of cancer mortality and 5-Fluorouracil (5-FU) is the most common chemotherapy agent of CRC. A high level of X-ray repair cross complementing group 1 (XRCC1) in cancer cells has been associated with the drug resistance occurrence. Moreover, the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) has been indicated to regulate the cancer cell survival. Thus, this study was aimed to examine whether XRCC1 plays a role in the 5-FU/AMPK agonist (AICAR)-induced cytotoxic effect on CRC and the underlying mechanisms. Human HCT-116 colorectal cells were used in this study. It was shown that 5-FU increases the XRCC1 expression in HCT-116 cells and then affects the cell survival through CXCR4/Akt signaling. Moreover, 5-FU combined with AICAR further result in more survival inhibition in HCT-116 cells, accompanied with reduced CXCR4/Akt signaling activity and XRCC1 expression. These results elucidate the role and mechanism of XRCC1 in the drug resistance of HCT-116 cells to 5-FU. We also demonstrate the synergistic inhibitory effect of AMPK on 5-FU-inhibited HCT-116 cell survival under the 5-FU and AICAR co-treatment. Thus, our findings may provide a new notion for the future drug regimen incorporating 5-FU and AMPK agonists for the CRC treatment.

Herbal prescription, Danggui-Sayuk-Ga-Osuyu-Senggang-Tang, inhibits TNF-α-induced epithelial-mesenchymal transition in HCT116 colorectal cancer cells.

Tumor necrosis factor‑α‑mediated (TNF‑α) epithelial‑mesenchymal transition (EMT) is associated with distant metastasis in patients with colorectal cancer with poor prognosis. Although traditional herbal medicines have long been used to treat colorectal cancer, the incidence and mortality in patients with colorectal cancer has continued to increase. Danggui‑Sayuk‑Ga‑Osuyu‑Saenggang‑Tang (DSGOST) has long been used for treatment of chills, while few studies have reported its anticancer effect. This study aimed to demonstrate the inhibitory effect of DSGOST on TNF‑α‑mediated invasion and migration of colorectal cancer HCT116 cell lines. MTT was used to measure cell viability. Wound healing and Τranswell invasion assay were used to detect migration and invasion of cells, respectively. The intracellular localization of proteins of interest was assessed by immunocytochemistry. Western blotting was performed to determine the expression level of various proteins. A non‑toxic dose of DSGOST (50µg/ml) on HCT116 cells was determined by MTT assay. Furthermore, DSGOST prevented the TNF‑α‑induced invasive phenotype in HCT116 cells. DSGOST inhibition of the invasive phenotype was also associated with increased expression of EMT markers. Furthermore, DSGOST treatment blocked TNF‑α‑induced migration and invasion of HCT116 cells. In addition, DSGOST treatment inhibited TNF‑α‑mediated nuclear translocation of Snail. DSGOST treatment also downregulated TNF‑α‑induced phosphorylation of AKT and glycogen synthase kinase‑3β. Therefore, the findings of the current study suggest that DSGOST exhibits anti‑migration and anti‑invasion effects in TNF‑α‑treated HCT116 human colorectal cells.

Antiproliferative and apoptosis inducing effects of citral via p53 and ROS-induced mitochondrial-mediated apoptosis in human colorectal HCT116 and HT29 cell lines

Despite various anticancer reports, antiproliferative and apoptosis inducing activity of citral in HCT116 and HT29 cells have never been reported. This study aimed to evaluate the cytotoxic and apoptosis inducing effects of citral in colorectal cancer cell lines. The citral-treated cells were subjected to MTT assay followed by flow cytometric Annexin V-FITC/PI, mitochondrial membrane potential and intracellular reactive oxygen species (ROS) determination. The apoptotic proteins expression was investigated by Western blot analysis. Citral inhibited the growth of HCT116 and HT29 cells by dose- and time-dependent manner without inducing cytotoxicity in CCD841-CoN normal colon cells. Flow cytometric analysis showed that citral (50–200μM; 24–48h) induced the externalization of phoshpotidylserine and reduced the mitochondrial membrane potential in HCT116 and HT29 cells. Citral elevated intracellular ROS level while attenuating GSH levels in HCT116 and HT29 cells which were reversed with N-acetycysteine (2mM) pre-treatment indicating that citral induced mitochondrial-mediated apoptosis via augmentation of intracellular ROS. Citral induced the phosphorylation of p53 protein and the expression of Bax while decreasing Bc-2 and Bcl-xL expression which promoted the cleavage of caspase-3. Collectively, our data suggest that citral induced p53 and ROS-mediated mitochondrial-mediated apoptosis in human colorectal cancer HCT116 and HT29 cells.

MicroRNA-335 inhibits colorectal cancer HCT116 cells growth and epithelial-mesenchymal transition (EMT) process by targeting Twist1.

Colorectal cancer is one of the most commonly diagnosed cancers. Recently, several microRNAs (miRNAs) have been characterized as oncogenes or tumor suppressors in colorectal cancer. This study was aimed to explore the tumor suppressive effects and its underling mechanism of miR-335 on colorectal cancer cells. Human colorectal cancer HCT116 cells were employed and the expression of miR-335 in cells was altered by transfection with miR-335 mimic and miR-335 inhibitor. Thereafter, CCK-8 assay, flow cytometry, Transwell assay and Western blotting were used to detect cell viability, apoptosis, migration, invasion, and the expression of epithelial-mesenchymal transition (EMT)-related proteins. Dual luciferase activity assay was performed to test whether Twist1 was a direct target of miR-335. Moreover, cells were co-transfected with miR-335 inhibitor and Twist1 siRNA, and then cell growth and metastasis were re-evaluated. miR-335 overexpression inhibited cell viability, migration and invasion, and promoted apoptotic cells rate. miR-335 overexpression up-regulated E-Cadherin, while down-regulated N-Cadherin, Vimentin and Snail. Twist1 was a direct target of miR-335, and Twist1 silence promoted apoptosis, and abolished miR-335 suppression induced increases in cell viability, migration, invasion, and abnormal expressions of EMT-related proteins. Besides, Twist1 silence abolished miR-335 suppression induced activations of p65 and IκBα, and miR-335 suppression induced up-regulations of Wnt3a, Wnt5a and β-Catenin. miR-335 inhibited HCT116 cells growth, migration, invasion, and ETM process. miR-335 exhibited tumor suppressive effects possibly by inhibition of Twsit1 and thus inactivating NF-κB and Wnt/β-catenin pathways.

Optimization of Aqueous Extraction and Biological Activity of Harpagophytum procumbens Root on Ex Vivo Rat Colon Inflammatory Model.

Harpagophytum procumbens has a long story of use for the treatment of inflammatory diseases. Considering both the antiinflammatory effects of H. procumbens in multiple tissues and the stability of harpagoside in artificial intestinal fluid, the aim of the present study was to explore the possible protective role of a microwave-assisted aqueous Harpagophytum extract (1-1000μg/mL) on mouse myoblast C2C12 and human colorectal adenocarcinoma HCT116 cell lines, and isolated rat colon specimens challenged with lipopolysaccharide (LPS), a validated ex vivo model of acute ulcerative colitis. In this context, we evaluated the effects on C2C12 and HCT116 viability, and on LPS-induced production of serotonin (5-HT), tumor necrosis factor (TNF)-α, prostaglandin (PG)E2 and 8-iso-prostaglandin (8-iso-PG)F2α . Harpagophytum extract was well tolerated by C2C12 cells, while reduced HCT116 colon cancer cell viability. On the other hand, Harpagophytum extract reduced H2 O2 -induced (1mM) reactive oxygen species (ROS) production, in both cell lines, and inhibited LPS-induced colon production of PGE2 , 8-iso-PGF2α , 5-HT and TNFα. Concluding, we demonstrated the efficacy of a microwave-assisted Harpagophytum aqueous extract in modulating the inflammatory, oxidative stress and immune response in an experimental model of inflammatory bowel diseases (IBD), thus suggesting a rational use of Harpagophytum in the management and prevention of ulcerative colitis in humans. Copyright © 2017 John Wiley & Sons, Ltd.

Indole phytoalexin derivatives induce mitochondrial-mediated apoptosis in human colorectal carcinoma cells.

AIMTo investigate the mechanism of the antiproliferative effect of synthetic indole phytoalexin derivatives on human colorectal cancer cell lines.METHODSChanges in cell proliferation and the cytotoxic effect of the tested compounds on human colorectal cancer cell lines and human fibroblasts were evaluated using MTS and BrdU assay, allowing us to choose the most potent substance. Cell cycle alterations were analyzed using flow cytometric analysis. The apoptosis-inducing effect of compound K-453 on the HCT116 cell line was examined with annexin V/PI double staining using flow cytometry, as well as acridine orange/propidium iodide (AO/PI) staining. The flow cytometry method also allowed us to measure changes in levels or activation states of other factors associated with apoptosis, such as poly (ADP-ribose) polymerase (PARP), caspase-3 and -9, cytochrome c, Bcl-2 family proteins, and also the integrity of the mitochondrial membrane. To evaluate activity of the transcription factors and proteins involved in signaling pathways we used Western blot analysis together with flow cytometry.RESULTSAmong the ten tested compounds, compound K-453 {(±)-trans-1,2-dimethoxy-2’-(3,5-bis-trifluoromethylphenylamino)spiro{indoline-3,5’[4’,5’]dihydrothiazol} exhibited the most potent activity with IC50 = 32.22 ± 1.14 μmol/L in human colorectal HCT116 cells and was thus selected for further studies. Flow cytometric analysis revealed a K-453-induced increase in the population of cells with sub-G1 DNA content, which is considered as a marker of apoptotic cell death. The apoptosis-inducing effect of compound K453 was also confirmed by annexin V/PI double staining and AO/PI staining. The apoptosis was associated with the loss of mitochondrial membrane potential, PARP cleavage, caspase-3 and caspase-9 activation, release of cytochrome c, as well as changes in the levels of Bcl-2 family members. Moreover, flow cytometry showed that compound K-453 stimulates phosphorylation of p38 MAPK but decreases phosphorylation of Akt and Erk 1/2. Activation of p38 MAPK was also confirmed using Western blot analysis. This analysis also revealed down-regulation of NF-κB1 (p50) and RelA (p65) proteins and the loss of their anti-apoptotic activity.CONCLUSIONIn our study compound K-453 exhibited an antiproliferative effect by induction of intrinsic apoptosis as well as modulation of several signaling pathways.

Multifunctional Hyaluronic Acid and Chondroitin Sulfate Nanoparticles: Impact of Glycosaminoglycan Presentation on Receptor Mediated Cellular Uptake and Immune Activation.

Hyaluronic acid (HA) and chondroitin sulfate (CS) polymers are extensively used for various biomedical applications, such as for tissue engineering, drug delivery, and gene delivery. Although both these biopolymers are known to target cell surface CD44 receptors, their relative cellular targeting properties and immune activation potential have never been evaluated. In this article, we present the synthesis and characterization of novel self-assembled supramolecular HA and CS nanoparticles (NPs). These NPs were developed using fluorescein as a hydrophobic component that induced amphiphilicity in biopolymers and also efficiently stabilized anticancer drug doxorubicin (DOX) promoting a near zero-order drug release. The cellular uptake and cytotoxicity studies of these NPs in different human cancer lines, namely, human colorectal carcinoma cell line HCT116 and human breast cancer cell line MCF-7 demonstrated dose dependent cytotoxicity. Interestingly, both NPs showed CD44 dependent cellular uptake with the CS-DOX NP displaying higher dose-dependent cytotoxicity than the HA-DOX NP in different mammalian cells tested. Immunological evaluation of these nanocarriers in an ex vivo human whole blood model revealed that unlike unmodified polymers, the HA NP and CS NP surprisingly showed platelet aggregation and thrombin-antithrombin complex formation at high concentrations (0.8 mg/mL). We also observed a clear difference in early- and late-stage complement activation (C3a and sC5b-9) with CS and CS NP triggering significant complement activation at high concentrations (0.08-0.8 mg/mL), unlike HA and HA NP. These results offer new insight into designing glycosaminoglycan-based NPs and understanding their hematological responses and targeting ability.

Dihydrochelerythrine and its derivatives: Synthesis and their application as potential G-quadruplex DNA stabilizing agents

A convenient route was envisaged toward the synthesis of dihydrochelerythrine (DHCHL), 4 by intramolecular Suzuki coupling of 2-bromo-N-(2-bromobenzyl)-naphthalen-1-amine derivative 5 via in situ generated arylborane. This compound was converted to (±)-6-acetonyldihydrochelerythrine (ADC), 3 which was then resolved by chiral prep-HPLC. Efficiency of DHCHL for the stabilization of promoter quadruplex DNA structures and a comparison study with the parent natural alkaloid chelerythrine (CHL), 1 was performed. A thorough investigation was carried out to assess the quadruplex binding affinity by using various biophysical and biochemical studies and the binding mode was explained by using molecular modeling and dynamics studies. Results clearly indicate that DHCHL is a strong G-quadruplex stabilizer with affinity similar to that of the parent alkaloid CHL. Compounds ADC and DHCHL were also screened against different human cancer cell lines. Among the cancer cells, (±)-ADC and its enantiomers showed varied (15–48%) inhibition against human colorectal cell line HCT116 and breast cancer cell line MDA-MB-231 albeit low enantio-specificity in the inhibitory effect; whereas DHCHL showed 30% inhibition against A431 cell line only, suggesting the compounds are indeed cancer tissue specific.

한방이화주 주박 추출물에 의한 암세포 항성장 및 세포사멸 기전 연구

본 연구에서는 한국 전통 막걸리 중 하나인 한방 이화주의 주박으로부터 에탄올 추출물과 그것의 순차적인 유기용매 분획물을 획득하고, 이들 시료들이 인간 대장암 세포인 HCT116 세포주의 cell viability와 pro-apoptotic 유전자인 ATF-3와 NAG-1의 발현에 미치는 영향을 연구하였다. 처리된 유기용매 시료 가운데 KSD-E3-2 분획물 (hexane 분획물)과 KSD-E3-3 분획물 (ethyl acetate 분획물)의 처리에 의해 현저하게 세포생존율이 감소하였으며, 두 분획물에 의해 농도의존적으로 세포 생존율이 감소하였다. 또한, 두 분획물의 처리에 의해 pro-apoptotic 유전자인 NAG-1과 ATF-3의 유전자와 단백질의 발현이 증가함을 확인하였다. 특히, KSD-E3-3 분획물 0.1 mg/ml의 처리에 의해 NAG-1 단백질의 발현이 현저하게 증가하였으며, 또한 apoptosis의 지표인 PARP cleavage가 관찰되었다. 이러한 KSD-E3-3 분획물에 의해 유도된 apoptosis는 NAG-1 siRNA transfection에 의해 회복됨을 확인하였다. 따라서, KSD-E3-3 분획물에 의한 NAG-1 단백질의 발현증가와 apoptosis 간의 직접적인 관련성이 있음을 시사한다. 종합적으로 본 연구 결과는 한방이화주 주박에 함유된 생리활성물질의 암세포 항 성장 활성 및 apoptosis기전을 이해하는데 도움을 줄 것으로 생각된다. In the present study, ethanol extracts and their subsequent organic solvent fractions were extracted from the lees of Ehwa Makgeolli containing oriental herbs, a commercialized traditional Korean rice wine, and the prepared lees samples were designated as from KSD-E3-1 to KSD-E3-5. First, their effects on cell viability and on the expression of pro-apoptotic ATF3 and NAG-1 genes in human colorectal HCT116 cells were investigated. Among the treated lees samples, the hexane fraction (KSD-E3-2) and the ethyl acetate fraction (KSD-E3-3) of lees extracts from Ehwa Makgeolli significantly reduced cell viabilities, in a dose dependent manner. The treatment with KSD-E3-2 and KSD-E3-3 also increased the expression of pro-apoptotic NAG-1 and ATF-3 genes and their proteins, which were detected with RT-PCR and Western blot analysis, respectively. In addition, poly-(ADP-ribose) polymerase (PARP) cleavage was detected by treatment with the fraction KSD-E3-3, indicating that KSD-E3-3 could induce apoptosis in HCT116 cells. Interestingly, this PARP cleavage was recovered by transfection of NAG-1 small interfering RNA. The results indicate that NAG-1 is one of the genes responsible for apoptosis induced by the fraction KSD-E3-3 from Ehwa Makgeolli. Overall, the findings may help in understanding the molecular mechanisms of the anti-proliferative and pro-apoptotic activities mediated by the lees of Ehwa Makgeolli.

DUSP6 is a novel transcriptional target of p53 and regulates p53-mediated apoptosis by modulating expression levels of Bcl-2 family proteins

p53 regulates various cellular responses through transcriptional regulation of distinct sets of target genes. Dual specificity phosphatase 6 (DUSP6) is a cytosolic phosphatase that inactivates the extracellular-signal-regulated kinase 1/2 (ERK1/2). This study demonstrates that p53 transactivates DUSP6 in human colorectal HCT116 cells to regulate ERK1/2 in p53-mediated cell death. DUSP6 is transactivated by p53 overexpression and genotoxic agents, and chromatin immunoprecipitation revealed two p53-binding sites in the DUSP6 promoter responsible for DUSP6 induction. Expression of shDUSP6 inhibited 5′-FU-induced cell death, whereas overexpression of DUSP6 increased susceptibility to 5′-FU. 5′-FU treatment dephosphorylated ERK in a DUSP6-dependent manner, resulting in destabilization of Bcl-2 and stabilization of Bad. These results provide insights on the modulatory role of p53 in the survival pathway by up-regulating DUSP6.

Abstract 938: Metabolomic analysis on pharmacological responses to oxaliplatin plus 5-FU in colorectal cancer cells

Abstract Purpose: Oxaliplatin (L-OHP) in combination with 5-fluorouracil (5-FU)/leucovorin (FOLFOX regimen) is an important treatment of metastatic colorectal cancer. However, metabolic functions to determine pharmacological response to L-OHP in combination with 5-FU are still unclear. The purpose of this study is to elucidate metabolomic responses to L-OHP in combination with 5-FU and key pathways relating to chemosensitivity. Experimental Procedures: Human colorectal carcinoma, HCT116 (high-sensitive) and DLD-1 (low-sensitive) cells, were exposed to L-OHP, 5-FU or L-OHP plus 5-FU. After treatment with the anti-cancer agents, the intracellular metabolites were extracted by liquid-liquid extraction and simultaneously and quantitatively analyzed by capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). The mRNA expression level of spermidine/spermine N1-acetyltransferase (SSAT) was measured by real-time quantitative RT-PCR (Taqman PCR). Results: N1-acetylspermine and N8-acetylspermidine in polyamine metabolism were accumulated to a greater extent after L-OHP exposure in drug-sensitive cancer cells. The mRNA expression level of SSAT-1, a key enzyme in polyamine catabolism, increased after L-OHP exposure in drug-sensitive cancer cells but not drug-resistant cancer cells. In addition to the up-regulation of polyamine metabolism in drug-sensitive cancer cells, the intracellular levels of endogenous nucleotides remarkably increased after L-OHP exposure in drug-sensitive cancer cells. These results imply the changes in nucleotide metabolism due to the disruption of DNA synthesis by L-OHP. The intracellular level of α-alanine also accumulated after L-OHP exposure in drug-sensitive cancer cells. α-alanine is known as a pyrimidine catabolite of uracil. These results show that nucleotide metabolism and polyamine metabolism may be important metabolic pathways relating to L-OHP chemosensitivity. Furthermore, in drug-sensitive cancer cells, polyamine metabolism, glutathione metabolism, and nucleotide metabolism were up-regulated after exposure to L-OHP plus 5-FU. On the other hand, metabolites belonging to each metabolic pathway on the whole increased moderately after exposure to L-OHP plus 5-FU in drug-resistant cancer cells. Conclusions: Polyamine metabolism, glutathione metabolism, and nucleotide metabolism are important metabolic pathways relating to responsiveness to L-OHP plus 5-FU. The present CE-TOFMS metabolome analysis created a new finding on metabolomic response to L-OHP plus 5-FU in colorectal cancer cells with different chemosensitivities. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 938. doi:1538-7445.AM2012-938

브로콜리 유래 sulforaphane에 의한 NAG-1과 p21 유전자의 발현 조절

본 연구에서는 대장암 세포주 모델에서 브로콜리 유래 sulforaphane에 의한 항 성장 활성과 항암 단백질 NAG-1과 p21의 발현 및 발현 조절에 대해서 연구하였다. 그 결과, 처리한 sulforaphane의 농도가 증가됨에 따라 세포사멸이 증가되었고, 세포 생존율은 감소하였다. 또한, sulforaphane에 의한 항암 단백질 NAG-1과 p21의 발현증가를 농도별, 시간대별로 확인한 결과, 두 단백질 모두 sulforaphane 농도와 처리시간 의존적으로 발현이 증가됨을 확인하였다. Sulforaphane에 의한 NAG-1과 p21의 발현의 p53 의존성을 연구한 결과, p21의 발현은 p53에 의존적 이지만 NAG-1의 발현은 p53에 비 의존적인 것으로 생각된다. 또한, sulforaphane이 dietary histone deacetylase inhibitor로서 NAG-1의 발현을 증가시킬 가능성은 매우 미미한 것으로 생각된다. 전사조절인자인 ATF3의 발현을 sulforaphane을 시간대 별로 처리한 후 확인한 결과, 2시간째부터 발현이 증가되어 NAG-1의 발현 보다 먼저 증가됨을 확인하였다. 이러한 연구 결과는 sulforaphane의 항암 기능을 이해하는 새로운 기전을 제시해 줄 것으로 기대된다. We investigated the anti-proliferative activity of sulforaphane and expression changes of NAG-1 and p21 genes in response to sulforaphane treatment in human colorectal HCT116 cells. The results showed that sulforaphane decreased cell viabilities in a dose-dependent manner and induced expression of NAG-1 and p21 proteins in a dose-dependent and time-dependent manner. In addition, we found that NAG-1 expression by sulforaphane was not dependent on the presence of p53, whereas p21 expression was dependent on p53 presence. The results indicated that up-regulation of NAG-1 was not related with the activity of a dietary histone deacetylase inhibitor of sulforaphane. ATF3 induction was detected from 2 hr after sulforaphane treatment, indicating that ATF3 could be a transcription factor to up-regulate NAG-1 expression. The results of this study may help to increase our understanding of the molecular mechanism of anti-cancer activity mediated by sulforaphane in human colorectal cancer cells.

장수상황버섯 균사체를 이용한 고체 발효한약재의 대장암 세포성장 억제 활성

본 연구에서는, 장수상황버섯(Phellinus baumii) 균사체를 이용한 한약재 고체발효 추출물의 암세포 성장억제 효과를 확인하고자 36종의 한약재 및 이들의 고체발효 한약재 추출물을 대상으로, 인간 대장암세포(HCT116) 성장억제능, 정상세포(HEK-293, 3T3-L1 및MC3T3-E1)에 대한 세포독성 및 인간 적혈구 용혈활성을 평가하였다. 선별된 36종의 한약재 추출물은 100 <TEX>${\mu}g/ml$</TEX> 농도에서, 사인, 천궁, 석곡, 백선피, 시체, 두충, 백과, 신이, 와송, 삼칠, 견우자, 원지 및 괄루인의 13종에서 암세포 성장률이 50% 이하를 나타내었으며, 균사체 추출물은 46.3%의 성장률을 나타내었다. 반면 25종의 발효한약재 추출물은 대부분 암세포 성장억제능의 변화가 미미하였으나, 백선피, 백과, 신이, 황부자, 산약, 현삼 및 괄루인은 암세포 증식억제능이 유의적으로 감소하였으며, 도인, 골쇄보, 구기자 및 패모에서는 암세포 성장억제능이 유의적으로 증가하였다. 특히 골쇄보, 구기자 및 패모 추출물의 대장암세포에 대한 <TEX>$IC_{50}$</TEX>는 각각 394, 917 및 149 <TEX>${\mu}g/ml$</TEX>이었으나, 발효 후 각각 28, 85 및 80 <TEX>${\mu}g/ml$</TEX>를 나타내었다. 또한 발효 골쇄보, 구기자 및 패모 추출물은 200 <TEX>${\mu}g/ml$</TEX> 농도까지 정상세포에서 미미한 세포독성을 나타내었다. 이러한 결과는 장수상황버섯 균사체를 이용한 한약재 고체발효가 새로운 항암 활성물질 개발 및 신규의 생리활성물질 생산에 이용될 수 있음을 제시하고 있다. This study was carried out to investigate the anti-proliferative activity of solid-state fermented medicinal herbs which include Phellinus baumii. Methanol extracts were prepared from 36 different medicinal herbs and their fermented counterparts. These extracts were used to treat human colorectal HCT116 cell, human embryonic kidney cell HEK-293, pre-adipocyte cell 3T3-L1, and pre-osteoblast cell MC3T3-E1 for 24 hr. At a concentration of 100 <TEX>${\mu}g/ml$</TEX>, the extracts of Amomum villosum, Cnidium officinale Makino, Dendrobium moniliforme, Dictamnus dasycarpus, Diospyros kaki Thunb, Eucommia ulmoides Oliv, Ginkgo biloba L, Magnolia denudata Desrousseaux, Orostachys japonicus, Panax notoginseng, Pharbitis nil Choisy, Polygala tenuifolia and Trichosanthes kirilowii (seed) led to a < 50% decrease in cell proliferation, and mycelium of P. baumii showed a 46.3% decrease in cell proliferation. Meanwhile, the extracts of the 25 fermented herbs showed similar anti-proliferative activities compared to those of individual non-fermented herbs. However, the extracts of the fermented Drynaria fortunei Kunze (1), Lycium chinense Mill (2), Fritillaria thunbergii Miquel (3) and Prunus persica showed increased anti-proliferative activity. The <TEX>$IC_{50}s$</TEX> of (1), (2) and (3) were especially decreased to 28, 85 and 80 <TEX>${\mu}g/ml$</TEX> from 394, 917 and 149 <TEX>${\mu}g/ml$</TEX>, respectively. Furthermore, the cytotoxicity of the extracts of fermented (1), (2) and (3) against HEK-293, 3T3-L1, and MC3T3-E1was negligible up to 200 <TEX>${\mu}g/ml$</TEX>. These results suggest that solid-state fermentation using the mycellium of P. baumiiproduce potential anti-cancer agents or strengthen the bioactivity of medicinal herbs.