HCT116 Human Colon Cancer Cells Research Articles

Colon cancer inhibitory properties of Caulerpa lentillifera polysaccharide and its molecular mechanisms based on three-dimensional cell culture model

Caulerpa lentillifera is rich in polysaccharides, and its polysaccharides show a significant effect in different biological activities including anti-cancer activity. As an edible algae-derived polysaccharide, exploring the role of colon cancer can better develop the application from a dietary therapy perspective. However, more in-depth studies of C. lentillifera polysaccharide on anti-colon cancer activity and mechanism are needed. In this study, we found that Caulerpa lentillifera polysaccharides (CLP) showed potential anti-colon cancer effect on human colon cancer cell HT29 in monolayer (IC50 = 1.954 mg/mL) and spheroid (IC50 = 0.402 mg/mL). Transcriptomics and metabolomics analyses revealed that CLP had an inhibitory effect on HT29 3D spheroid cells by activating aminoacyl-tRNA biosynthesis as well as arginine and proline metabolism pathways. Furthermore, the anti-colon cancer effects of CLP were confirmed through other human colon cancer cell HCT116 and LoVo in monolayer cells (IC50 = 1.890 mg/mL and 1.437 mg/mL, respectively) and 3D spheroid cells (IC50 = 0.344 mg/mL and 0.975 mg/mL, respectively), and three patient-derived organoids with IC50 values of 6.333–8.780 mg/mL. This study provided basic data for the potential application of CLP in adjuvant therapeutic food for colon cancer on multiple levels, while further investigation of detailed mechanism in vivo was still required.

R-phycoerythrin alginate/shellac beads by external gelation: Process optimization and the effects of gastrointestinal digestion for nutraceutical applications

This study aimed to evaluate an alginate/shellac mixture as wall material to develop an aqueous phycoerythrin (R-PE) encapsulation system by external gelation and to determine the effect of encapsulation on the biological properties of R-PE released during simulated gastrointestinal digestion. The Taguchi method was implemented to formulate beads with a high R-PE encapsulation efficiency (EE). The effect of the variables: feeding flow (90 and 20 mL h−1), distance (5 and 10 cms), and CaCl2 (5 and 15 g L−1) were optimized, and the bead size, sphericity factor (SF), and total R-PE content were characterized. Finally, the optimal alginate/shellac beads were subjected to in vitro dynamic gastrointestinal digestion. The results show that the beads formed under optimal conditions reached an EE value of 97.5 %. The CaCl2 concentration and feeding flow most affected the R-PE EE. The release of R-PE from alginate/shellac was affected at acid pH 1; however, the concentration was under 10 % of the total R-PE content showing promising targeting properties in terms of time and pH. The R-PE extracts and capsules were partially degraded in gastric and intestinal conditions; the mouth did not detect signals from the protein profile. The encapsulation of alginate/shellac led to higher R-PE contents at the end of digestion than non-encapsulated R-PE, suggesting a protective role. Significantly, from permeate streams, equivalent to the absorption of encapsulated R-PE, the bioavailability was 2.5 times higher than non-encapsulated R-PE. NMR results indicate the presence of R-PE and its methyl amino acids and oligosaccharides between 0.5 and 2.5 and 3.8–6.8 ppm, respectively. Cytotoxicity activity was observed for the R-PE extract on the HCT-116 human colon cancer cell line. The alginate/shellac as a wall material and ionic gelation technology used may determine the release of the R-PE pigment at an intestinal site and its antiproliferative effect on health.

Green synthesis of silver nanoparticles using Illicium verum extract: Optimization and characterization for biomedical applications

Abstract The synthesis of noble metal nanoparticles is currently experiencing substantial development and considerable attention. Plant extracts are commonly used for the biological synthesis of nanoparticles because they contain biologically active constituents. In our present study, silver nanoparticles (AgNPs) were synthesized using an aqueous Illicium verum (Star anise) extract to evaluate their antimicrobial, antioxidant, and cytotoxicity activities. For maximum yields of AgNPs, the extract (2.5 ml), silver ions (500 µM), and pH (8) were shown to be the ideal nanoparticle production parameters. The visual colour shifted from pale brown to dark brown when the ultraviolet-visible spectrophotometer was used to validate the synthesis of AgNPs. A transmission electron microscope was utilized to evaluate nanoparticles’ physical nature. The presence of silver metal with face-centred cubic symmetry was confirmed by X-ray diffraction analysis. Fourier-transform infrared spectroscopy was used to identify the functional groups in charge of reducing silver ions (Ag+) and the stability of AgNPs produced using the I. verum aqueous extract. The agar well diffusion method investigated the antibacterial activity of I. verum silver nanoparticles (Iv-AgNPs) against pathogenic bacteria and fungi. At higher doses (100 µg·mL−1), the highest zone of inhibition was observed, and spherical AgNPs demonstrated the antibacterial activity. The I. verum extract and Iv-AgNPs enhanced (70%) their free radical scavenging activity at 500 µg·mL−1 according to the 2,2-diphenyl-1-picrylhydrazyl assay. Moreover, the cytotoxicity of Iv-AgNPs against the HCT-116 human colon cancer cell line indicated cell inhibition in a dose-dependent manner. Ultimately, the findings of this study indicate that techniques used to produce AgNPs are environmental friendly, cost-effective, harmless, uncomplicated, and can effectively tackle a broad spectrum of medical and nutritional concerns.

Everolimus exerts anticancer effects through inhibiting the interaction of matrix metalloproteinase-7 with syndecan-2 in colon cancer cells.

Previous work showed that matrix metalloproteinase-7 (MMP-7) regulates colon cancer activities through an interaction with syndecan-2 (SDC-2) and SDC-2-derived peptide that disrupts this interaction and exhibits anticancer activity in colon cancer. Here, to identify potential anticancer agents, a library of 1,379 Food and Drug Administration (FDA)-approved drugs that interact with the MMP-7 prodomain were virtually screened by protein-ligand docking score analysis using the GalaxyDock3 program. Among five candidates selected based on their structures and total energy values for interacting with the MMP-7 prodomain, the known mechanistic target of rapamycin kinase (mTOR) inhibitor, everolimus, showed the highest binding affinity and the strongest ability to disrupt the interaction of the MMP-7 prodomain with the SDC-2 extracellular domain in vitro. Everolimus treatment of the HCT116 human colon cancer cell line did not affect the mRNA expression levels of MMP-7 and SDC-2 but reduced the adhesion of cells to MMP-7 prodomain-coated plates and the cell-surface localization of MMP-7. Thus, everolimus appears to inhibit the interaction between MMP-7 and SDC-2. Everolimus treatment of HCT116 cells also reduced their gelatin-degradation activity and anticancer activities, including colony formation. Interestingly, cells treated with sirolimus, another mTOR inhibitor, triggered less gelatin-degradation activity, suggesting that this inhibitory effect of everolimus was not due to inhibition of the mTOR pathway. Consistently, everolimus inhibited the colony-forming ability of mTOR-resistant HT29 cells. Together, these data suggest that, in addition to inhibiting mTOR signaling, everolimus exerts anticancer activity by interfering with the interaction of MMP-7 and SDC-2, and could be a useful therapeutic anticancer drug for colon cancer.NEW & NOTEWORTHY The utility of cancer therapeutics targeting the proteolytic activities of MMPs is limited because MMPs are widely distributed throughout the body and involved in many different aspects of cell functions. This work specifically targets the activation of MMP-7 through its interaction with syndecan-2. Notably, everolimus, a known mTOR inhibitor, blocked this interaction, demonstrating a novel role for everolimus in inhibiting mTOR signaling and impairing the interaction of MMP-7 with syndecan-2 in colon cancer.

A Facile Ugi/Ullmann Cascade Reaction to Access Fused Indazolo-Quinoxaline Derivatives with Potent Anticancer Activity.

A facile methodology for the construction of a complex heterocycle indazolo-fused quinoxalinone has been developed via an Ugi four-component reaction (U-4CR) followed by an intramolecular Ullmann reaction. The expeditious process features an operationally simple approach, time efficiency, and a broad substrate scope. Biological activity was evaluated and demonstrated that compound 6e inhibits human colon cancer cell HCT116 proliferation with an IC50 of 2.1 μM, suggesting potential applications for developing a drug lead in medicinal chemistry.

Synthesis, molecular docking study, and biological evaluation and of new thiadiazole and thiazole derivatives incorporating isoindoline-1,3-dione moiety as anticancer and antimicrobial agents

To highlight the importance of thiazole and thiadiazole derivatives in the progression of cancer and microbial treatments and to aid in drug design, we have synthesized a new series of 1,3,4-thiadiazole and 1,3-thiazole derivatives. These were created by a two-step reaction process: initially, 2-(4-(2-bromoacetyl)phenyl)isoindoline-1,3-dione was reacted with potassium thiocyanate, and then the resulting thiocyanate intermediate was coupled with aryl diazonium salts to produce iminothiadiazole derivatives. These derivatives served as crucial intermediates for further synthesizing a range of thiadiazole derivatives using different reagents. Additionally, treating 2-(4-(2-bromoacetyl) phenyl)isoindoline-1,3-dione with thiourea resulted in aminothiazole derivatives. These were further coupled with arenediazonium chloride to form 5-arylazoaminothiazole derivatives. All the synthesised compounds were characterised using IR, 1H NMR and 13C NMR spectrum data, as well as physical data. The assessment of the synthesized compounds on the HCT-116 human colon cancer cell line has yielded promising results. Specifically, compounds 3a, 3b, 4b, 5b, 6b, and 9b have shown noteworthy efficacy, suggesting their potential as anticancer agents. These compounds have demonstrated a greater potency compared to the standard drug, doxorubicin, highlighting their significance in cancer treatment research. The study assessed the activity of various newly synthesized compounds against diverse microorganisms, including bacteria and fungi. Notably, two of these compounds, specifically 4b and 7b, exhibited significant efficacy against both gram-positive and gram-negative bacteria, surpassing the performance of a standard antibacterial reference agent. Furthermore, molecular docking of new products revealed interactions with enzyme binding sites, aligning with in vitro findings. Additionally, in-silico studies confirmed their favourable oral bioavailability through ADME profiling.

Bacterial amidohydrolases and modified 5-fluorocytidine compounds: Novel enzyme-prodrug pairs.

Gene-directed enzyme prodrug therapy is an emerging strategy for cancer treatment based on the delivery of a gene that encodes an enzyme that is able to convert a prodrug into a potent cytotoxin exclusively in target cancer cells. However, it is limited by the lack of suitable enzyme variants and a scarce choice of chemical bonds that could be activated. Therefore, this study is aimed to determine the capability of bacterial amidohydrolases YqfB and D8_RL to activate novel prodrugs and the effect such system has on the viability of eukaryotic cancer cells. We have established cancer cell lines that stably express the bacterial amidohydrolase genes and selected several N4-acylated cytidine derivatives as potential prodrugs. A significant decrease in the viability of HCT116 human colon cancer cell lines expressing either the YqfB or the D8_RL was observed after exposure to the novel prodrugs. The data we acquired suggests that bacterial YqfB and D8_RL amidohydrolases, together with the modified cytidine-based prodrugs, may serve as a promising enzyme-prodrug system for gene-directed enzyme prodrug therapy.

Metabolomics reveals that Curcuma longa and demethoxycurcumin inhibit HCT116 human colon cancer cell growth

Studies on the use of natural products to treat cancer are ongoing, and turmeric (Curcuma longa L.), a medicinal crop, is known for various effects including anticancer activity. In this study, the inhibitory effect of C. longa and demethoxycurcumin on cancer cell growth in a colorectal cancer cell line (HCT116) was investigated by using nuclear magnetic resonance (NMR) spectroscopy-based metabolomics. For this analysis, HCT116 cells were treated with doxorubicin (positive control), C. longa extract, or demethoxycurcumin (20, 40, and 60 μM). In the NMR spectra of the HCT116 cell extract, 45 metabolites were identified and quantified. The quantified metabolites were analyzed by biomarker analysis, and significantly changed metabolites were filtered by the area under the curve (AUC) of the receiver operator characteristic (ROC) curve. Multivariate statistical analysis of NMR spectra was conducted to confirm the distribution among groups. Through an S-line plot, it was possible to identify metabolites that contributed to the differences seen in the OPLS-DA score plot. Taken together, the results reveal that C. longa extract induces oxidative stress and changes the energy metabolism in HCT116 cells, and that demethoxycurcumin inhibits the energy metabolism strategy for the survival of cancer cells, escape from immune cells, and cancer cell proliferation, thereby enabling the survival of HCT116 cells.

Combination of Selenite and Butyrate Enhances Efficacy Against Colon Cancer by Targeting ASCT2-Mediated Amino Acid Metabolism.

Drug combination is considered to be an effective approach to improve the efficacy of cancer therapy and chemoprevention. Selenite, a representative of inorganic form of selenium, and butyrate, a major short-chain fatty acid, are two well-documented colon cancer dietary chemopreventive agents with distinct molecular mechanisms. We hypothesized that combination of selenite and butyrate might produce improved outcome against colon cancer. This hypothesis was tested using both HCT116 human colon cancer cells and its xenograft mouse model in the present study. The in vitro study showed a synergistically inhibitory effect on HCT116 colon cancer cells but not on NCM460 normal human colon mucosal epithelial cells. Consistent with the in vitro study, results of the xenograft mouse model further demonstrated that combination of selenite and butyrate led to improved efficacy in comparison with each agent alone. Mechanistically, the induction of alanine-serine-cysteine transporter 2 (ASCT2) by selenite repressed its inhibitory effect on colon cancer cells, which was reversed by its co-treatment with butyrate. The findings of the present study denote the likely potential for developing selenite/butyrate combination remedy to combat against colon cancer.

Elucidation of the anti-colon cancer mechanism of Phellinus baumii polyphenol by an integrative approach of network pharmacology and experimental verification

Colon cancer, a prevalent malignant tumor affecting the digestive system, presents a substantial risk to human health due to its high occurrence and mortality rates. Phellinus baumii polyphenol (PBP), a natural product derived from traditional Chinese medicine, has gained widespread popularity due to its low toxicity and minimal side effects, compared to radiation and chemotherapy. This study used an integrated approach of network pharmacology and experimental verification to elucidate the anti-colon cancer effects of PBP and its potential mechanisms. In network pharmacology, the identification of relevant targets involved a comprehensive search across multiple databases using keywords such as “active components of PBP” and “colon cancer”. Venn diagram analysis was subsequently performed to ascertain the shared targets. To identify the key active components and core targets, we constructed a network of “Disease-Drug-Pathways-Targets” and a protein-protein interaction (PPI) network among the targets using Cytoscape 3.9.1. Furthermore, molecular docking was carried out to predict the binding affinity and conformation between the main active compounds (davallialactone and citrinin) of PBP and the core targets (TP53, STAT3, CASP3, CTNNB1, PARP1, MYC). To validate our findings, in vitro experiments were conducted. We verified that PBP exerted an anti-colon cancer effect on human colon cancer HCT116 cells by significantly inhibiting cell proliferation, promoting apoptosis and arresting the cell cycle in S phase by using Cell Counting Kit-8 (CCK-8) and flow cytometry. Finally, we determined the key regulatory proteins related to apoptosis and the cell cycle by western blot analysis, and proposed the potential mechanism by which PBP exerts an anti-colon cancer effect by inducing the caspase-dependent mitochondrial-mediated intrinsic apoptotic pathway and arresting the cell cycle in S phase in HCT116 cells. These results suggest that PBP possesses substantial potential for the treatment of colon cancer and may serve as a viable alternative therapeutic strategy in colon cancer treatment.

Quantitative Chemical Proteomics Reveals Triptolide Selectively Inhibits HCT116 Human Colon Cancer Cell Viability and Migration Through Binding to Peroxiredoxin 1 and Annexin A1.

Triptolide (TPL), a natural product extracted from Tripterygium wilfordii Hook F, exerts potential anti-cancer activity. Studies have shown that TPL is involved in multiple cellular processes and signal pathways; however, its pharmaceutical activity in human colorectal cancer (CRC) as well as the underlying molecular mechanism remain elusive. In this study, the effects of TPL on HCT116 human colon cancer cells and CCD841 human colon epithelial cells are first evaluated. Next, the protein targets of TPL in HCT116 cells are identified through an activity-based protein profiling approach. With subsequent in vitro experiments, the mode of action of TPL in HCT116 cells is elucidated. As a result, TPL is found to selectively inhibit HCT116 cell viability and migration. A total of 54 proteins are identified as the targets of TPL in HCT116 cells, among which, Annexin A1 (ANXA1) and Peroxiredoxin I/II (Prdx I/II) are picked out for further investigation due to their important role in CRC. The interaction between TPL and ANXA1 or Prdx I is confirmed, and it is discovered that TPL exerts inhibitory effect against HCT116 cells through binding to ANXA1 and Prdx I. The study reinforces the potential of TPL in the CRC therapy, and provides novel therapeutic targets for the treatment of CRC.

Luteolin exhibits synergistic therapeutic efficacy with erastin to induce ferroptosis in colon cancer cells through the HIC1-mediated inhibition of GPX4 expression

Colon cancer continues to be a prevalent gastrointestinal malignancy with a bleak prognosis. The induction of ferroptosis, a new form of regulated cell death, has emerged as a potentially effective strategy for the treatment of colon cancer. However, numerous colon cancer cells display resistance to ferroptosis induced by erastin, a well-established ferroptosis inducer. Finding drugs that can enhance the susceptibility of colon cancer cells to erastin is of utmost importance. This study aimed to examine the synergistic therapeutic impact of combining erastin with a bioactive flavonoid compound luteolin on the ferroptosis-mediated suppression of colon cancer. Human colon cancer HCT116 and SW480 cells were used for the in vitro studies and a xenograft of colon cancer model in BALB/c nude mice was established for the in vivo experiments. The results showed that combinative treatment of luteolin and erastin effectively inhibited the viability and proliferation of colon cancer cells. Luteolin and erastin cotreatment synergistically induced ferroptosis, concomitant with a reduction in glutathione and an elevation in lipid peroxides. In vivo, combinative treatment of luteolin and erastin exhibited a pronounced therapeutic effect on xenografts of colon cancer, characterized by a significant induction of ferroptosis. Mechanistically, luteolin in combination with erastin synergistically reduced the expression of glutathione peroxidase 4 (GPX4), an antioxidase overexpressed in colon cancer cells. Furthermore, luteolin and erastin cotreatment significantly upregulated the expression of hypermethylated in cancer 1 gene (HIC1), a transcriptional repressor also recognized as a tumor suppressor. HIC1 overexpression notably augmented the suppression of GPX4 expression and facilitated ferroptotic cell death. In contrast, HIC1 silencing attenuated the inhibition of GPX4 expression and eliminated the ferroptosis. Conclusively, these results clearly demonstrated that luteolin acts synergistically with erastin and renders colon cancer cells vulnerable to ferroptosis through the HIC1-mediated inhibition of GPX4 expression, which may act as a promising therapeutic strategy.

Stereoselective synthesis and antiproliferative effect of methoxylated spirooxindoles on colon cancer cell lines

Background: Safe and effective anticancer drug discovery is still a challenge for medicinal chemists. Spirooxindoles have shown promising pre-clinical results in designing newer cancer therapeutic candidates. In order to find out the effect of electron-withdrawing groups on its effect on colon cancer, a series of pyrrolizidine and N-methyl pyrrolidine spirooxindole derivatives were synthesized and evaluated against human colon cancer cell lines. Methods: A highly efficient one-pot, multi component and stereoselective [3+2] cyclo addition reaction were employed to synthesize a series of pyrrolizidine and N-methyl pyrrolidine spirooxindole derivatives with electron-withdrawing methoxy substitutions. This method involves previously optimized reaction condition developed in our lab to achieve excellent regio- and stereoselectivity. The newly synthesized spirooxindole derivatives were evaluated for their antiproliferative efficacy against human colon cancer cell lines HT29 and HCT116. Results: The synthesized compounds were characterized using FTIR, NMR, and ESI-MS. RP-HPLC determined the purity, and the structure while the assigned stereochemistry were confirmed using X-ray crystallography. Compound 14a produced the best antiproliferative activity with IC50 values of 62.66 and 18.48 µM against HT29 and HCT116 human colon cancer cell lines. Conclusion: The described one-pot, multicomponent, [3+2] cycloaddition reaction proved to be a catalyst-free reaction with high atom economy and single-step reaction. The effectiveness of the compounds was determined through in vitro cell viability assays which revealed their potency against colon cancer. Thus the study can be explored further as a hit-to-lead studies by designing compounds with varied substituents.

Synthesis and In Vitro Anti-tumor Evaluation of Novel Glycoconjugated SN38 Derivatives

Abstract Five types of novel glycoconjugated 7-ethyl-10-hydroxycamptothecin (SN38) derivatives were synthesized to evaluate their anti-tumor activity against HCT116 human colon cancer cells, and the results showed that all of them demonstrated potent anti-tumor activity. Notably, glucose and galactose conjugates exhibited the better anti-tumor activity, while the mannose and allose conjugates had slightly lower activity. Our findings suggested that the anti-tumor activity of glycoconjugated SN38 derivatives was affected by the type of modifying molecule used and the position of the modification. These findings could have implications for the development of novel anti-tumor agents targeting glucose transporters.

Regulation of Epithelial-Mesenchymal Transition by Cyrtopodion Scabrum: An in vitro Study against Colorectal Cancer Cells.

Natural treatment of cancer has received a lot of attention recently due to its advantages including low cost, and fewer side effects. In this study, we aimed to investigate the antimetastatic properties of Cyrtopodion scabrum, a common home gecko, through Epithelial-Mesenchymal Transition (EMT) process. Human colon cancer HCT116 cell line was selected and allocated into the following experimental groups: untreated control, vehicle control (DMSO), Retinoic acid (RA), and two treatment groups including aqueous C.scabrum Whole Extract (CWE) and C.scabrum Cell Extract (CCE) groups. The effects of the two different extracts on the viability, migration, and morphology of HCT116 cells were investigated using MTT, colony formation, and wound healing assay as well as microscopic evaluation. We also investigated the gene expression of E-cad, N-cad, and Snail genes using Real-Time PCR analysis. Our findings revealed that CWE and CCE were toxic to the HCT116 cell line with IC50 values of 590 and 680 µg/mL, respectively. Colony formation and migration ability of cancer cells were also inhibited by the two extracts, and the morphology of the cells were determined as epithelial phenotype. Moreover, the expression of N-cad and Snail were remarkably decreased in CWE and CCE, and RA groups, while E-cad didn't change significantly as compared to the control. The results suggest that C. scabrum extract (CsE) may induce its anti-cancer activity through the inhibition of cancer cell growth and the EMT process. CCE, as a valuable natural source, could be also suggested, to be used as an alternative/complementary medicine for the treatment of cancer, in clinical trials.

Manganese nanocarrier for matrix metalloproteinase 9 responsive delivery of irinotecan for colon cancer treatment

Enzyme responsive nanocarriers are reactive or sensitive towards a specific enzyme and, therefore, have the advantages of low systemic toxicity, targeted delivery, and superior therapeutic effect with high efficiency. In this study, we have developed a matrix metalloproteinase 9 (MMP9) enzyme responsive manganese nanocarrier for the site-specific delivery of anticancer drugs. Manganese nanoparticles were coated with G5 PAMAM dendrimers and loaded with irinotecan hydrochloride (IRI). The drug loaded nanoparticles were further coated with collagen-IV (Col-IV) peptide, an MMP9 substrate, to make them MMP9 responsive (Col-IV@IRI-G5MNP). The developed nanoparticles were monodispersed with size of about 12 nm and high IRI encapsulation efficiency (80%). A faster but controlled IRI release was observed from Col-IV@IRI-G5MNP in HEPES buffer containing MMP9 enzyme. When incubated with human red blood cells, the nanoformulation was hemocompatible and caused <2% hemolysis. The anticancer activity of Col-IV@IRI-G5MNP against HCT116 human colon cancer cells was better than free IRI. The cell viability of HCT116 cells incubated with 25 µg/mL Col-IV@IRI-G5MNP was significantly lower (p < 0.001) than the cells incubated with free IRI. Further, Col-IV@IRI-G5MNP showed paramagnetic nature and good T2 relaxivity at a very low concentration, suggesting its potential use for diagnosis through magnetic resonance imaging.

Engineering siRNA-loaded and RGDfC-targeted selenium nanoparticles for highly efficient silencing of DCBLD2 gene for colorectal cancer treatment

Effective and safe delivery of small interfering RNA (siRNA) by nanomaterials to cancer cells is one of the main challenges in cancer treatment. In this study, we constructed the selenium nanoparticles conjugated with RGDfC (one tumor-targeted polypeptide) to prepare a biocompatible gene vector (RGDfC-SeNPs) and then loaded with siDCBLD2 to synthesize the RGDfC-Se@siDCBLD2 for colorectal cancer (CRC) therapy. As expected, RGDfC-SeNPs could enhance the cellular uptake of siDCBLD2 in human HCT-116 colon cancer cells by targeting polypeptide RGDfC on the surface of colon cancer cells. RGDfC-Se@siDCBLD2 could be effectively internalized by HCT-116 cells mainly through a clathrin-related endocytosis pathway. In addition, RGDfC-Se@siDCBLD2 exhibited high siRNA release efficiency in an acidic tumor environment. Moreover, RGDfC-Se@siDCBLD2 could inhibit the proliferation and induce apoptosis in HCT-116 cells by special silencing gene DCBLD2 expression. RGDfC-Se@siDCBLD2 could be specifically accumulated to the tumor sites and exhibited significantly anti-CRC efficacy on HCT-116 tumor-bearing mice without obvious side effects. Taken together, these results suggest that selenium nanoparticles can be used as an effective gene vector with good biocompatibility, and RGDfC-Se@siDCBLD2 provides a promising strategy for combining tumor-target and siRNA delivery in treating CRC.

Are the Cytotoxic Properties of Conjugated Unsaturated Ketones Inactivated by Thiols?

The focus of this study was to examine whether the conversion of cytotoxic conjugated unsaturated ketones (or enones) into the corresponding thiol adducts leads to a reduction or abolition of cytotoxic potencies. A number of enones and related thiol adducts were evaluated against human HCT116 and HT29 colon cancer cells. Some 63% of the IC50 values are less than 10 μM and several compounds are more toxic than 5-FU. The thiol adducts are either more potent or are equipotent with the corresponding enones. A number of compounds are far more toxic to HCT116 and HT29 neoplasms than non-malignant CRL1790 cells leading to impressive Selectivity Index figures. An additional positive feature of these compounds is that they have favorable ADME properties.

Concurrent Dual-Contrast Enhancement Using Fe3O4 Nanoparticles to Achieve a CEST Signal Controllability.

Traditional T2 magnetic resonance imaging (MRI) contrast agents have defects inherent to negative contrast agents, while chemical exchange saturation transfer (CEST) contrast agents can quantify substances at trace concentrations. After reaching a certain concentration, iron-based contrast agents can "shut down" CEST signals. The application range of T2 contrast agents can be widened through a combination of CEST and T2 contrast agents, which has promising application prospects. The purpose of this study is to develop a T2 MRI negative contrast agent with a controllable size and to explore the feasibility of dual contrast enhancement by combining T2 with CEST contrast agents. The study was carried out in vitro with HCT-116 human colon cancer cells. A GE SIGNA Pioneer 3.0 T medical MRI scanner was used to acquire CEST images with different saturation radio-frequency powers (1.25/2.5/3.75/5 μT) by 2D spin echo-echo planar imaging (SE-EPI). Magnetic resonance image compilation (MAGiC) was acquired by a multidynamic multiecho 2D fast spin-echo sequence. The feasibility of this dual-contrast enhancement method was assessed by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, dynamic light scattering, ζ potential analysis, inductively coupled plasma, X-ray photoelectron spectroscopy, X-ray powder diffraction, vibrating-sample magnetometry, MRI, and a Cell Counting Kit-8 assay. The association between the transverse relaxation rate r2 and the pH of the iron-based contrast agents was analyzed by linear fitting, and the linear relationship between the CEST effect in different B1 fields and pH was analyzed by the ratio method. Fe3O4 nanoparticles (NPs) with a mean particle size of 82.6 ± 22.4 nm were prepared by a classical process, and their surface was successfully modified with -OH active functional groups. They exhibited self-aggregation in an acidic environment. The CEST effect was enhanced as the B1 field increased, and an in vitro pH map was successfully plotted using the ratio method. Fe3O4 NPs could stably serve as reference agents at different pH values. At a concentration of 30 μg/mL, Fe3O4 NPs "shut down" the CEST signals, but when the concentration of Fe3O4 NPs was less than 10 μg/mL, the two contrast agents coexisted. The prepared Fe3O4 NPs had almost no toxicity, and when their concentration rose to 200 μg/mL at pH 6.5 or 7.4, they did not reach the half-maximum inhibitory concentration (IC50). Fe3O4 magnetic NPs with a controllable size and no toxicity were successfully synthesized. By combining Fe3O4 NPs with a CEST contrast agent, the two contrast agents could be imaged simultaneously; at higher concentrations, the iron-based contrast agent "shut down" the CEST signal. An in vitro pH map was successfully plotted by the ratio method. CEST signal inhibition can be used to realize the pH mapping of solid tumors and the identification of tumor active components, thus providing a new imaging method for tumor efficacy evaluation.

Metallohelices stabilize DNA three-way junctions and induce DNA damage in cancer cells.

DNA three-way junctions (3WJ) represent one of the simplest supramolecular DNA structures arising as intermediates in homologous recombination in the absence of replication. They are also formed transiently during DNA replication. Here we examine the ability of Fe(II)-based metallohelices to act as DNA 3WJ binders and induce DNA damage in cells. We investigated the interaction of eight pairs of enantiomerically pure Fe(II) metallohelices with four different DNA junctions using biophysical and molecular biology methods. The results show that the metallohelices stabilize all types of tested DNA junctions, with the highest selectivity for the Y-shaped 3WJ and minimal selectivity for the 4WJ. The potential of the best stabilizer of DNA junctions and, at the same time, the most selective 3WJ binder investigated in this work to induce DNA damage was determined in human colon cancer HCT116 cells. These metallohelices proved to be efficient in killing cancer cells and triggering DNA damage that could yield therapeutic benefits.