HCT116 Colon Cancer Cells Research Articles

Hyperforin and Myrtucommulone Derivatives Act as Natural Modulators of Wnt/β-Catenin Signaling in HCT116 Colon Cancer Cells

The therapeutic activities of natural plant extracts have been well known for centuries. Many of them, in addition to antiviral and antibiotic effects, turned out to have anti-tumor activities by targeting different signaling pathways. The canonical Wnt pathway represents a major tumorigenic pathway deregulated in numerous tumor entities, including colon cancer. Here, we investigated the acylphloroglucinols hyperforin (HF) from St. John’s wort (Hypericum perforatum L.) and myrtucommulone A (MC A) from myrtle (Myrtus communis) and semi-synthetic derivatives thereof (HM 177, HM 297, HM298) for their effects on Wnt/β-catenin signaling. None of these substances revealed major cytotoxicity on STF293 embryonic kidney and HCT116 colon carcinoma cells at concentrations up to 10 μM. At this concentration, HF and HM 177 showed the strongest effect on cell proliferation, whereas MC A and HM 177 most prominently inhibited anchorage-independent growth of HCT116 cells. Western blot analyses of active β-catenin and β-catenin/TCF reporter gene assays in STF293 cells revealed inhibitory activities of HF, MC A and HM 177. In line with this, the expression of endogenous Wnt target genes, Axin and Sp5, in HCT116 cells was significantly reduced. Our data suggest that the acylphloroglucinols hyperforin, myrtucommulone A and its derivative HM 177 represent potential new therapeutic agents to inhibit Wnt/β-catenin signaling in colon cancer.

Effects of Bismuth Oxide Nanoparticles, Cisplatin and Baicalein-rich Fraction on ROS Generation in Proton Beam irradiated Human Colon Carcinoma Cells

Abstract Introduction: Proton beam radiotherapy is an advanced cancer treatment technique, which would reduce the effects of radiation on the surrounding healthy cells. The usage of radiosensitizers in this technique might further elevate the radiation dose towards the cancer cells. Material and methods: The present study investigated the production of intracellular reactive oxygen species (ROS) due to the presence of individual radiosensitizers, such as bismuth oxide nanoparticles (BiONPs), cisplatin (Cis) or baicalein-rich fraction (BRF) from Oroxylum indicum plant, as well as their combinations, such as BiONPs-Cis (BC), BiONPs-BRF (BB), or BiONPs-Cis-BRF (BCB), on HCT-116 colon cancer cells under proton beam radiotherapy. Results: It was found that the ROS in the presence of Cis at 3 Gy of radiation dose was the highest, followed by BC, BiONPs, BB, BRF, and BCB treatments. The properties of bismuth as a radical scavenger, as well as the BRF as a natural compound, might contribute to the lower intracellular ROS induction. The ROS in the presence of Cis and BC combination were also time-dependent and radiation dose-dependent. Conclusions: As the prospective alternatives to the Cis, the BC combination and individual BiONPs showed the capacities to be developed as radiosensitizers for proton beam therapy.

In Vitro Screening for Cytotoxic Effect of Pore Forming Colicin N and Its Domains on Human Cancer Cells.

Protein-based drugs have increasingly become an important segment of cancer treatment. In comparison with chemotherapy, they offer high efficacy and fewer side effects due to specifically targeting only cancer cells. Monoclonal antibodies are currently the main protein-based drugs in the market but their complexity and limitations in tumour penetration led to the development of alternative protein therapeutics such as pore-forming toxins. Colicin N (ColN), a pore-forming protein produced by E. coli, was previously found to exhibit cytotoxicity and selectivity in human lung cancer cells with promising potential for further development. Here we aimed to screen for the cytotoxicity of ColN in breast (MCF-7 and MDA-MB-231), lung (A549) and colon cancer cells (HT-29 and HCT-116) by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay with various concentrations for 72 h and to investigate the cytotoxic effect of ColN domains on cancer cells. It showed that ColN mildly mediated the decrease in cell viability except for MCF-7. The highest effect was seen in A549 and HCT-116 cells which showed 31.9% and 31.5% decrease in cell viability, respectively. The mild inhibition or promotion of cancer cell proliferation by ColN tend to be based on the cell types. Furthermore, to search for the functional domain of ColN used for cytotoxicity, full-length ColN and truncated ColN with deletion of translocating, receptor binding and pore-forming domains were also tested on HCT-116 colon cancer cells. The findings indicated that HCT-116 cells were not significantly sensitive to ColN but full length ColN caused slight decrease in cancer cell viability. The data in this study will benefit the further development of ColN for alternative protein-based cancer therapy.

In PD-1+ human colon cancer cells NIVOLUMAB promotes survival and could protect tumor cells from conventional therapies

BackgroundColorectal cancer (CRC) is one of the most prevalent and deadly tumors worldwide. The majority of CRC is resistant to anti-programmed cell death-1 (PD-1)-based cancer immunotherapy, with approximately 15% with...

Effect of Sodium Butyrate on p16INK4a, p14ARF, p15INK4b, Class I HDACs (HDACs 1, 2, 3) Class II HDACs (HDACs 4, 5, 6), Cell Growth Inhibition and Apoptosis Induction in Pancreatic Cancer AsPC-1 and Colon Cancer HCT-116 Cell Lines.

Background:In higher eukaryotes, cell-cycle transitions are regulated by different cyclin-dependent kinases (Cdks) and Cdk inhibitors (CKIs). CKIs include two groups, the Ink4 (p16INK4a, p15INK4b, p18INK4c, and p19INK4d) and the Cip/Kip (p21Cip1, p27Kip1, and p57Kip2) families. The hyperactivity of histone deacetylases (HDACs) is associated with cancer induction. Histone deacetylase inhibitors (HDACIs) such as sodium butyrate (NaBT) can inhibit HDAC activity resulting in apoptosis induction. The present study was designed to investigate the effect of sodium butyrate on p16INK4a, p14ARF, p15INK4b, class I HDACs (HDACs 1, 2, 3), and class II HDACs (HDACs 4, 5, 6), cell growth inhibition, and apoptosis induction in pancreatic cancer AsPC-1 and colon cancer HCT-116 cell lines. In fact, we want to know whether sodium butyrate can reactivate Ink4 and Cip/Kip families by HDACs inhibition. Materials and Methods:The AsPC-1 and HCT-116 cells were treated with sodium butyrate at different periods. Then, the MTT assay, cell apoptosis assay, and qRT-PCR were done to determine viability, apoptosis, and the relative expression level of the genes respectively. Results:The sodium butyrate increased p16INK4a, p14ARF, and p15INK4b and decreased class I and II HDACs significantly. Besides, HCT-116 cell was more sensitive to sodium butyrate in comparison to AsPC-1 cell. Conclusion: The sodium butyrate can reactivate the p16INK4a, p14ARF, and p15INK4b through inhibition of HDACs in AsPC-1 and HCT-116 cell lines.

Upregulation of BAX and caspase-3, as well as downregulation of Bcl-2 during treatment with indeno[1,2-b]quinoxalin derivatives, mediated apoptosis in human cancer cells.

Cancer is the world's foremost cause of death. There are over 100 different forms of cancer. Cancers are frequently named after the organs or tissues in which they develop. As a part of our aim to develop promising anticancer agents, a series of new indeno[1,2-b]quinoxaline derivatives were synthesized. All of the synthesized compounds were tested for anticancer activity in vitro in three human cancer cell lines: the HCT-116 colon cancer cell line, the HepG-2 liver cancer cell line, and the MCF-7 breast cancer cell line. Among the tested derivatives, 2, 3, 5, 12, 21, and 22 showed exceptional antiproliferative activities against the three tested cell lines compared to the reference standard imatinib. These compounds were, therefore, selected for further investigations. Evaluation of their cytotoxicity against a normal human cell line (WI-38) was performed, to ensure their safety and selectivity (IC50 > 92 μM). Then, induction of apoptosis by the most active compounds was found to be accomplished by downregulation of Bcl-2 and upregulation of BAX and caspase-3. After that, the most promising apoptotic compound that increases the caspase-3 and BAX expression and downregulates Bcl-2 activity (3) was assessed for its impact on the cell cycle distribution in HepG-2 cells: The most potent derivative (3) induced cell cycle arrest at the G2/M phase. Finally, in silico evaluation of the ADME properties indicated that compound 3 is orally bioavailable and can be readily synthesized on a large scale.

Thymopentin-Mediated Inhibition of Cancer Stem Cell Stemness Enhances the Cytotoxic Effect of Oxaliplatin on Colon Cancer Cells.

Thymopentin (TP5) is an immunomodulatory pentapeptide that has been widely used in malignancy patients with immunodeficiency due to radiotherapy and chemotherapy. Here, we propose that TP5 directly inhibits the stemness of colon cancer cells HCT116 and therefore enhances the cytotoxicity of oxaliplatin (OXA) in HCT116 cells. In the absence of serum, TP5 was able to induce cancer stemness reduction in cultured HCT116 cells and significantly reduced stemness-related signals, such as the expression of surface molecular markers (CD133, CD44 and CD24) and stemness-related genes (ALDH1, SOX2, Oct-4 and Nanog), and resulted in altered Wnt/β-catenin signaling. Acetylcholine receptors (AchRs) are implicated in this process. OXA is a common chemotherapeutic agent with therapeutic effects in various cancers. Although TP5 had no direct effect on the proliferation of HCT116, this pentapeptide significantly increased the sensitivity of HCT116 to OXA, where the effect of TP5 on the stemness of colon cancer cells through stimulation of AchRs may contribute to this process. Our results provide a promising strategy for increasing the sensitivity of colon cancer cells to chemotherapeutic agents by incorporating immunomodulatory peptides.

Discovery, Synthesis, and Biological Evaluation of Anaenamides C and D from a New Marine Cyanobacterium, Hormoscilla sp.

Our ongoing efforts to explore the chemical space associated with marine cyanobacteria from coral reefs of Guam have yielded two new members of the anaenamide family of natural products, anaenamides C (3) and D (4). These compounds were isolated from a novel Hormoscilla sp. (VPG16-58). Our phylogenetic profiling (16S rDNA) of this cyanobacterium indicated that VPG16-58 is taxonomically distinct from the previously reported producer of the anaephenes, VPG16-59 (Hormoscilla sp.), and other previously documented species of the genus Hormoscilla. The planar structures of 3 and 4 were determined via spectroscopic methods, and absolute configurations of the α-hydroxy acids were assigned by enantioselective HPLC analysis. To address the requirement for sufficient material for testing, we first adapted our published linear synthetic approach for 1 and 2 to generate anaenoic acid (7), which served as a point for diversification, providing the primary amides 3 and 4 from synthetic intermediates 5 and 6, respectively. The compounds were then tested for effects on HCT116 colon cancer cell viability and in an ARE-luciferase reporter gene assay for Nrf2 modulation using HEK293 human embryonic kidney cells. Our findings indicate that, in contrast to cytotoxic methyl esters 1 and 2, the primary amides 3 and 4 activate the Nrf2 pathway at noncytotoxic concentrations. Overall, our data suggest that the anaenamide scaffold is tunable to produce differential biological outcomes.

UHMK1-dependent phosphorylation of Cajal body protein coilin alters 5-FU sensitivity in colon cancer cells

Resistance to 5-fluorouracil (5-FU) in chemotherapy and recurrence of colorectal tumors is a serious concern that impedes improvements to clinical outcomes. In the present study, we found that conditioned medium (CM) derived from 5-FU-resistant HCT-8/FU cells reduced 5-FU chemosensitivity in HCT-8 colon cancer cells, with corresponding changes to number and morphology of Cajal bodies (CBs) as observable nuclear structures. We found that U2AF homology motif kinase 1 (UHMK1) altered CB disassembly and reassembly and regulated the phosphorylation of coilin, a major component of CBs. This subsequently resulted in a large number of variations in RNA alternative splicing that affected cell survival following 5-FU treatment, induced changes in intracellular phenotype, and transmitted preadaptive signals to adjacent cells in the tumor microenvironment (TME). Our findings suggest that CBs may be useful for indicating drug sensitivity or resistance in tumor cells in response to stress signals. The results also suggest that UHMK1 may be an important factor for maintaining CB structure and morphology by regulating splicing events, especially following cellular exposure to cytotoxic drugs.Graphical EzAUFb-Sx6xbWL9vLuNL_4Video

Synthesis, solubility and antitumor activity of maslinic acid derivatives

Maslinic acid (MA), a pentacyclic triterpenoid obtained from olives that is characterized by its antiproliferative activity in tumor cells, has become a promising molecule that could be modified to improve cancer treatment. In this work we have synthesized in good yields several new MA conjugates, including glycerin, oligo(ethylene glycol), and amino acid derivatives (compounds 3a-f). The synthesis offers the possibility of recovering unreacted MA, and thus the scaling up of the process. For the tyramine-MA conjugate, compound 3f or TMA, the preparation has been optimized to a one-pot reaction. Solubility of conjugates in polar solvents has been measured, showing a marked increase of solubility with respect to MA. Moreover, we selected the tyramidyl maslinic acid conjugate (3f or TMA) to determine antitumor capacity over a wide range of cancer cell lines, including glioblastoma, melanoma, breast, lung, colorectal and pancreatic cancer. Our results clearly demonstrated that TMA induced higher cytotoxicity in all cancer cell types compared to MA. TMA was more effective than MA, especially in breast cancer cells (MCF-7) and melanoma cells (B16–F10) where IC50 reductions of 4.12 and 4.72, respectively, was detected. Interestingly, TMA showed a remarkable antitumor ability against the resistant HCT-15 colon cancer cell line. Furthermore, we demonstrated for the first time a relevant effect of a MA derivative against glioblastoma cells (A172 and SF-268). These results suggest that TMA is able to improve the antitumor characteristics of MA in a wide range of cancers and that it may be a promising compound for various tumor types, including resistant cancer.

Cordycepin inhibits colon cancer proliferation by suppressing MYC expression

BackgroundCordycepin is a purine nucleoside anti-metabolite and anti-biotic isolated from the fungus Cordyceps militaris, which has potential anti-neoplastic activities. This study aimed to investigate the effect of cordycepin in inhibiting colon cancer development.MethodsThe proliferation of cordycepin-treated HCT116 and Caco-2 colon cancer cell lines was assessed with 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the viability was measured with colony formation assay. At the same time, cordycepin responsive gene and microRNAs (miRNAs, miRs) were screened by qRT-PCR. MYC over-expressing HCT116 and Caco-2 cell lines were constructed, which were further transfected with miR-26a. Inhibitory effect of cordycepin on cell proliferation was evaluated with cell viability assay, cell number count, and colony formation assay. The relative expression of MYC and miR-26a was detected by qRT-PCR and Western blot.ResultsCordycepin inhibited colon cancer cell proliferation by down-regulating MYC mRNA/protein expression and up-regulating miR-26a in both HCT116 and Caco-2 cells. MYC over-expression could suppress the expression of miR-26a, which could be restored by cordycepin treatment. Additional miR-26a transfection in MYC over-expressing cells could reverse MYC over-expression-promoted proliferation, which could be further potentiated by cordycepin treatment.ConclusionCordycepin is able to suppress colon cancer cell proliferation, likely mediated by the MYC/miR-26a pathway, supporting its potential for the treatment of colon cancer.

Ceftazidime and cefepime antagonize 5-fluorouracil\u2019s effect in colon cancer cells

BackgroundDrug-drug interaction (DDI), which can occur at the pharmacokinetics and/or the pharmacodynamics (PD) levels, can increase or decrease the therapeutic or adverse response of a drug itself or a combination of drugs. Cancer patients often receive, along their antineoplastic agents, antibiotics such as ß-lactams to treat or prevent infection. Despite the narrow therapeutic indices of antibiotics and antineoplastic agents, data about their potential interaction are insufficient. 5-fluorouracil (5-FU), widely used against colon cancer, is known for its toxicity and large intra- and inter- individual variability. Therefore, knowledge about its interaction with antibiotics is crucial.MethodsIn this study, we evaluated at the PD levels, against HCT-116 colon cancer cells, DDI between 5-FU and several ß-lactams (ampicillin, benzypenicillin, piperacillin, meropenem, flucloxacillin, ceftazidime (CFT), and cefepime (CFP)), widely used in intensive care units. All drugs were tested at clinically achieved concentrations. MTT assay was used to measure the metabolic activity of the cells. Cell cycle profile and apoptosis induction were monitored, in HCT-116 and DLD-1 cells, using propidium iodide staining and Caspase-3/7 activity assay. The uptake of CFT and CFP by the cells was measured using LC-MS/MS method.ResultsOur data indicate that despite their limited uptake by the cells, CFT and CFP (two cephalosporins) antagonized significantly 5-FU-induced S-phase arrest (DLD-1 cells) and apoptosis induction (HCT-116 cells). Remarkably, while CFP did not affect the proliferation of colon cancer cells, CFT inhibited, at clinically relevant concentrations, the proliferation of DLD-1 cells via apoptosis induction, as evidenced by an increase in caspase 3/7 activation. Unexpectedly, 5-FU also antagonized CFT’s induced cell death in DLD-1 cells.ConclusionThis study shows that CFP and CFT have adverse effects on 5-FU’s action while CFT is a potent anticancer agent that inhibits DLD-1 cells by inducing apoptotic cell death. Further studies are needed to decipher the mechanism(s) responsible for CFT’s effects against colon cancer as well as the observed antagonism between CFT, CFP, and 5-FU with the ultimate aim of translating the findings to the clinical settings.

Effect of Thymidine Phosphorylase Gene Demethylation on Sensitivity to 5-Fluorouracil in Colorectal Cancer Cells.

Chemotherapy is used for recurrent and metastatic colorectal cancer, but the response rate of 5-fluorouracil (5-FU), the standard treatment for colorectal cancer, is low. We hypothesized that thymidine phosphorylase (TYMP) expression, a rate-limiting activating enzyme of 5-FU, is regulated by methylation of the gene promoter region, and demethylation of TYMP would increase sensitivity to 5-FU. HCT116 colon cancer cells were treated with 5-aza-2'-deoxycytidine, a demethylating agent, and changes in TYMP transcription and sensitivity to 5-FU were evaluated. TYMP expression increased over 54-fold in HCT116 transfected with TYMP. The cytotoxicity of 5-FU increased up to 5.5-fold. In comparison, in HCT116 treated with 5-aza-2'-deoxycytidine, TYMP expression increased 5.8-fold. However, the cytotoxicity of 5-FU remained unchanged. Demethylating agent alone did not promote the cytotoxicity of 5-FU against colorectal cancer. To further increase the sensitivity to 5-FU, combination with adjuvant therapy focusing on metabolic pathways other than the TYMP pathway appear necessary.

Disruption of Crystal Packing in Thieno[2,3-b]pyridines Improves Anti-Proliferative Activity.

3-Amino-2-arylcarboxamido-thieno[2,3-b]pyridines have been shown to have anti-proliferative activity, but are also known to have poor solubility. This has been previously proposed to be due to their extensive planarity, which allows for intermolecular stacking and crystal packing. We herein report the synthesis of fifteen novel thieno[2,3-b]pyridines that have incorporated bulky, but easily cleavable, ester and carbonate functional groups in an effort to decrease crystal packing. The addition of these ‘prodrug-like’ moieties into the thieno[2,3-b]pyridine resulted in compounds with increased activity against HCT-116 colon cancer cells and the triple-negative breast cancer cell line MDA-MB-231.

The Effect of Liposomal Diallyl Disulfide and Oxaliplatin on Proliferation of Colorectal Cancer Cells: In Vitro and In Silico Analysis.

Diallyl disulfide (DADS) is one of the main bioactive organosulfur compounds of garlic, and its potential against various cancer models has been demonstrated. The poor solubility of DADS in aqueous solutions limits its uses in clinical application. The present study aimed to develop a novel formulation of DADS to increase its bioavailability and therapeutic potential and evaluate its role in combination with oxaliplatin (OXA) in the colorectal cancer system. We prepared and characterized PEGylated, DADS (DCPDD), and OXA (DCPDO) liposomes. The anticancer potential of these formulations was then evaluated in HCT116 and RKO colon cancer cells by different cellular assays. Further, a molecular docking-based computational analysis was conducted to determine the probable binding interactions of DADS and OXA. The results revealed the size of the DCPDD and DCPDO to be 114.46 nm (95% EE) and 149.45 nm (54% EE), respectively. They increased the sensitivity of the cells and reduced the IC50 several folds, while the combinations of them showed a synergistic effect and induced apoptosis by 55% in the cells. The molecular docking data projected several possible targets of DADS and OXA that could be evaluated more precisely by these novel formulations in detail. This study will direct the usage of DCPDD to augment the therapeutic potential of DCPDO against colon cancer in clinical settings.

The Anticancer Ruthenium Compound BOLD-100 Targets Glycolysis and Generates a Metabolic Vulnerability towards Glucose Deprivation.

Cellular energy metabolism is reprogrammed in cancer to fuel proliferation. In oncological therapy, treatment resistance remains an obstacle and is frequently linked to metabolic perturbations. Identifying metabolic changes as vulnerabilities opens up novel approaches for the prevention or targeting of acquired therapy resistance. Insights into metabolic alterations underlying ruthenium-based chemotherapy resistance remain widely elusive. In this study, colon cancer HCT116 and pancreatic cancer Capan-1 cells were selected for resistance against the clinically evaluated ruthenium complex sodium trans-[tetrachlorobis(1H-indazole)ruthenate(III)] (BOLD-100). Gene expression profiling identified transcriptional deregulation of carbohydrate metabolism as a response to BOLD-100 and in resistance against the drug. Mechanistically, acquired BOLD-100 resistance is linked to elevated glucose uptake and an increased lysosomal compartment, based on a defect in downstream autophagy execution. Congruently, metabolomics suggested stronger glycolytic activity, in agreement with the distinct hypersensitivity of BOLD-100-resistant cells to 2-deoxy-d-glucose (2-DG). In resistant cells, 2-DG induced stronger metabolic perturbations associated with ER stress induction and cytoplasmic lysosome deregulation. The combination with 2-DG enhanced BOLD-100 activity against HCT116 and Capan-1 cells and reverted acquired BOLD-100 resistance by synergistic cell death induction and autophagy disturbance. This newly identified enhanced glycolytic activity as a metabolic vulnerability in BOLD-100 resistance suggests the targeting of glycolysis as a promising strategy to support BOLD-100 anticancer activity.

Synthesis, Crystal Structure, Hirshfeld Surface Analysis and Docking Studies of a Novel Flavone–Chalcone Hybrid Compound Demonstrating Anticancer Effects by Generating ROS through Glutathione Depletion

The flavone–chalcone hybrid compound, (E)-6-bromo-3-(3-(2-methoxyphenyl)-3-oxoprop-1-enyl)-4H-chromen-4-one (3), was synthesized and its three dimensional structure was identified by X-ray crystallography. The compound 3, C19H13BrO4, was crystallized in the triclinic space group P-1 with the following cell parameters: a = 8.2447(6) Å; b = 8.6032(6) Å; c = 11.7826(7) Å; α = 92.456(2)°; β = 91.541(2)°; γ = 106.138(2)°; V = 801.42(9) Å3 and Z = 2. In an asymmetric unit, two molecules are packed by a pi–pi stacking interaction between two flavone rings that are 3.790 Å apart from each other. In the crystal, two hydrogen bonds form inversion dimers and these dimers are extended along the a axis by another hydrogen bond. Hirshfeld analysis revealed that the H–H (34.3%), O–H (19.2%) and C–H (16.7%) intermolecular contacts are the major dominants, while the C–O (6.7%) and C–C (6.5%) are minor dominants. When HCT116 cells were treated with various concentrations of hybrid compound 3, reduced cell viability and induced apoptosis in HCT116 cells were observed in a dose-dependent manner. The treatment of HCT116 colon cancer cells with compound 3, decreased the intracellular glutathione (GSH) levels and generated a reactive oxygen species (ROS). In silico docking experiments between the compound 3 and glutathione S-transferase (GST) containing glutathione were performed to confirm whether the compound 3 binds to glutathione. Their binding energy ranged from −6.6 kcal/mol to −5.0 kcal/mol, and the sulfur of glutathione is very close to the Michael acceptor regions of the compound 3, so it is expected that they would easily react with each other. Compound 3 may be a promising novel anticancer agent by ROS generation through glutathione depletion.

Hinokiflavone, as a MDM2 inhibitor, activates p53 signaling pathway to induce apoptosis in human colon cancer HCT116 cells

Hinokiflavone (HF), a natural biflavonoid that possesses various biological activities, has reported that HF could be a pre-mRNA splicing modulator, whereas its underlying mechanisms remain elusive. In the present study, we identified HF as a potential MDM2 inhibitor. What's more, we found that HF suppressed mdm2 mRNA synthesis at the transcriptional level. Then, this MDM2 inhibition led in turn to increase p53 protein expression and activate p53 pathway, which could decrease the survival of HCT116 colon cells by G2/M phase arrest and apoptosis induction. Then, bioinformatics suggested that ESR1 was a predicted and potential target of HF. Finally, we used molecular docking and molecular dynamics simulation to demonstrate the binding patterns of HF and ESR1. To sum up, our study unearthed that HF was a feasible agent for MDM2 inhibitor through down-regulating mdm2 RNA level and activating p53 signaling pathway.

Effect of 5'-fluoro-2'-deoxycytidine, 5-azacytidine, and 5-aza-2'–deoxycytidine on DNA Methyltransferase 1, CIP/KIP Family, and INK4a/ARF in Colon Cancer HCT-116 Cell Line

Background: Cyclin-dependent kinase inhibitors (CKIs) are the negative regulator of cell cycle progression, which inhibits cyclin-cdk complexes, resulting in cell cycle arrest. Recently, we evaluated the effect of 5-Aza-CdR on DNMT1 gene expression in the WCH-17 hepatocellular carcinoma (HCC) cell line. Objectives: The current study was designed to analyze the effects of 5-aza-2'–deoxycytidine (5-Aza-CdR, decitabine), 5-azacytidine (5-AzaC, vidaza), and 5'-fluoro-2'-deoxycytidine (FdCyd) on INK4a/ARF, CIP/KIP, and DNA methyltransferase 1 gene expression, apoptosis induction, and cell growth inhibition in colon cancer HCT-116 cell line. Methods: The colon cancer HCT-116 cell line was treated with 5-azaC, 5-Aza-CdR, and FdCyd at 24 and 48h. To determine colon cancer HCT-116 cell viability, cell apoptosis, and the relative expression level of the INK4a/ARF, CIP/KIP, and DNA methyltransferase 1 genes, MTT assay, flow cytometry, and qRT-PCR were done, respectively. Results: 5-azaC, 5-Aza-CdR, and FdCyd significantly inhibited colon cancer HCT-116 cell growth and induced apoptosis. Besides, they significantly increased CIP/KIP (p21CIP1, p27KIP1, and p57KIP2) and INK4 (p14ARF, p15INK4b, and p16INK4a) and decreased DNMT1 gene expression. Besides, minimal and maximal apoptosis were seen in the groups treated with FdCyd and 5-Aza-CdR, respectively. The IC50 for CAF for FdCyd was 1.72 ± 0.23 and 1.63 ± 0.21μM at 24 and 48h, respectively. The IC50 for CAF for 5-AzaC was 2.18 ± 0.33 and 1.98 ± 0.29 μM at 24 and 48h, respectively. The IC50 for CAF for 5-Aza-CdR was 4.08 ± 0.61 and 3.18 ± 0.50 μM at 24 and 48h, respectively. Conclusions: The 5-azac, 5-Aza-CdR, and FdCyd can reactivate the INK4a/ARF and CIP/KIP families through inhibition of DNMT1 activity.

Fucoidan and Alginate from the Brown Algae Colpomenia sinuosa and Their Combination with Vitamin C Trigger Apoptosis in Colon Cancer.

Brown seaweeds are producers of bioactive molecules which are known to inhibit oncogenic growth. Here, we investigated the antioxidant, cytotoxic, and apoptotic effects of two polysaccharides from the brown algae Colpomenia sinuosa, namely fucoidan and alginate, in a panel of cancer cell lines and evaluated their effects when combined with vitamin C. Fucoidan and alginate were isolated from brown algae and characterized by HPLC, FTIR, and NMR spectroscopy. The results indicated that highly sulfated fucoidans had higher antioxidant and cytotoxic effects than alginate. Human colon cancer cells were the most sensitive to the algal treatments, with fucoidan having an IC50 value (618.9 µg/mL−1) lower than that of alginate (690 µg/mL−1). The production of reactive oxygen species was increased upon treatment of HCT-116 cells with fucoidan and alginate, which suggest that these compounds may trigger cell death via oxidative damage. The combination of fucoidan with vitamin C showed enhanced effects compared to treatment with fucoidan alone, as evidenced by the significant inhibitory effects on HCT-116 colon cancer cell viability. The combination of the algal polysaccharides with vitamin C caused enhanced degeneration in the nuclei of cells, as evidenced by DAPI staining and increased the subG1 population, suggesting the induction of cell death. Together, these results suggest that fucoidan and alginate from the brown algae C. sinuosa are promising anticancer compounds, particularly when used in combination with vitamin C.