Cancer HCT116 Cells Research Articles

Synthesis and in silico studies of certain benzo[f]quinoline-based heterocycles as antitumor agents

A series of benzoquinoline-employing heterocycles was synthesized by treating 3-chlorobenzo[f]quinoline-2-carbaldehyde with N-phenyl-3-methylpyrazolone, 4-aminoacetophenone, 1,2-diaminoethane, and 2-cyanoethanohydrazide. Also, pyridine, chromene, α,β-unsaturated nitrile, thiosemicarbazone, and 1,2-bis-aryl hydrazine derivatives were prepared from the cyanoethanohydrazone obtained. The DFT calculations and experiment outcomes were consistent. In vitro screening of their antiproliferative efficacy was examined against HCT116 and MCF7 cancer cell lines. The pyrazolone 2 and cyanoethanohydrazone 5 derivatives exhibited the most potency, which was demonstrated by their molecular docking towards the CDK-5 enzyme. The binding energies of compounds 2 and 5 were − 6.6320 kcal/mol (with RMSD of 0.9477 Å) and − 6.5696 kcal/mol (with RMSD of 1.4889 Å), respectively, which were near to that of co-crystallized ligand (EFP). This implies a notably strong binding affinity towards the CDK-5 enzyme. Thus, pyrazolone derivative 2 would be considered a promising candidate for further optimization to develop new chemotherapeutic agents. In addition, the ADME (absorption, distribution, metabolism, and excretion) analyses displayed its desirable drug-likeness and oral bioavailability properties.

Oxidative Stress Induction by Gold Nanoparticles in HCT-116 Colon Cancer Cells

Background: Gold nanoparticles (AuNPs), a new cancer treatment, have few side effects. Objectives: This study aimed to investigate the effect of AuNPs on oxidative stress in HCT-116 colon cancer cells. Methods: The viability of HCT-116 cells was evaluated using the 3-(4,5-dimethylthiazol-2,5-diphenyl) tetrazolium bromide (MTT) assay after 24 and 48 hours of incubation with different concentrations of AuNPs (0 - 50 μg/mL). The state of oxidative stress, total antioxidant capacity (TAC), total oxidative status (TOS), reactive oxygen species (ROS) levels, and the activity of antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT), were determined by colorimetric and fluorometric methods. Results: Oxidative stress parameters and ROS were significantly increased in cells treated with 25 and 50 μg/mL concentrations of AuNPs during 24 and 48 hours of incubation compared to control cells (P < 0.001). In contrast, the level of TAC and the activity of antioxidant enzymes SOD, GPX, and CAT were significantly decreased in the treated groups compared to the untreated cells after 48 hours of incubation (P < 0.05). Conclusions: This study showed that AuNPs affect HCT-116 cancer cells by increasing ROS and oxidative stress while reducing the activity of antioxidant enzymes.

Investigation the Cytotoxic and Antimicrobial Effect of Ranunculus Poluninii

Ranunculus plant species, one of the endemic plants, are used in the treatment of various diseases such as febrile diseases, rheumatism and inflammatory rashes due to their pharmacological and toxicological activities. Considering these features, it was aimed to investigate the cytotoxic effects of Ranunculus poluninii on cancer cell lines, bacteria and yeasts. For this purpose, the extract of the plant was obtained by methanol extraction. Different concentrations of stock were prepared from this plant and applied to A549 and HCT116 cancer cell lines, and MTT assay was performed to determine cell viability. In addition, MIC values were determined by applying the prepared plant extract to Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, Candida albicans and Candida glabrata. Our results showed that Ranunculus poluninii was reduced cell viability to 83.7% at 100 µg/mL and 79% at 200 µg/mL on A549 and HCT116 respectively. In addition, it decreased both Candida albicans and Candida glabrata growth to 91.5% at 800 µg/m and 95.1% at 50 µg/mL respectively. Our results suggest that Ranunculus poluninii has anticancer effect and antifungal activity.

An Efficient Synthesis of Novel Aminothiazolylacetamido-Substituted 3,5-Bis(arylidene)-4-piperidone Derivatives and Their Cytotoxicity Studies.

The expansion of 3,5-bis(arylidene)-4-piperidone derivatives with heterocyclic compounds such as 1,3-thiazole should take into account this correlation. The synthesized aminothiazolylacetamido-substituted 3,5-bis(arylidene)-4-piperidone derivatives 3a-j were found to have GI50 values in the range of 0.15-0.28 μM against HeLa and HCT116 cancer cell lines. In silico docking studies confirmed that the proteasome inhibition mechanism involves a nucleophilic attack from the N-terminal threonine residue of the β-subunits to the C=O group of compounds. A C=O group of amide was able to interact with the NH group of the alanine residue and the 5g NH group of amino thiazole, along with an OH group of the serine residue. These results strongly suggest that the synthesized compounds could be a potential candidate inhibitor of the 20S proteasome. These molecules have the potential to be developed as cytotoxic and anticancer agents, as revealed by this study.

Optimisation of Levilactobacillus brevis-fermented finger millet (Eleusine coracana) and evaluation of its effects on cancer cells (HCT116 and MDA-MB-231)

The objective of this study was to optimise the millet formulation using Levilactobacillus brevis and to evaluate its anticarcinogenic potential in vitro. The formula was developed in the course of the fermentation of finger millet (Eleusine coracana) using L. brevis MTTC 4460 and optimised by response surface methodology and validation by artificial neural networking (ANN). The optimised millet formulation could be obtained using 2 % of bacterial inoculum, 2 % of glucose, and a fermentation duration of 3.3 days with a yield of 5.98 mg/mL lactic acid and 3.38 log10 (CFU/mL) viable L. brevis with overall desirability value of 1. The fermented millet formulation exhibited antiproliferative and antimigratory effects on MDA-MB-231 and HCT116 cancer cell lines. In addition, the outcomes observed in western blot analysis revealed that the formulation elicited apoptotic responses mediated by the Bcl-2 family of proteins in MDA-MB-231 and HCT116 cell lines while demonstrating no discernible impact on HEK293 normal cells.

A New Source and Large Quantity of Resveratrol in Cratoxylum Species and Their Activities on Normal Human and Cancer Cells.

Cratoxylum formosum ssp. formosum (Cff), C. formosum ssp. pruniflorum (Cfp), and C. sumatranum (Cs) were investigated for phytochemical analysis. Toxicity testing, programmed cell death, and cell cycle arrest were tested on CHL-1, HCT-116, and HepG2 cancer cell lines, and human normal PBMCs. The results are revealed in the following order. The phytochemical percentages varied in each species, the quantity and concentration of α-amyrin and resveratrol were 0.038 mg/g and 0.955 mg/mL, and 0.064 mg/g and 0.640 mg/mL. The most studied Cratoxylum extracts showed IC50 values in PBMCs and cancer cell lines except for the hexane Cff and ethanol Cfp extracts. All studied extracts did not induce DNA breaks in PBMCs but caused significant DNA breaks in the cancer cell lines. All studied extracts induced both apoptosis and necrosis in cancer cell lines, and the DNA quantity in the S and G2-M phases decreased significantly but did not induce apoptosis and necrosis in PBMCs. Except for the ethanolic extracts of Cff and Cfp that induced PBMCs apoptosis and necrosis, these data confirmed that the three studied Cratoxylum samples have inhibiting properties for the growth of cancer cells and low toxicity to PBMCs. Cs showed more toxicity to cancer cell lines than Cf and cisplatin.

Distribution and Level of Bioactive Monoacylglycerols in 12 Marine Microalgal Species.

Microalgae are currently considered an attractive source of highly valuable metabolites potentially exploitable as anticancer agents, nutraceuticals and cosmeceuticals and for bioenergy purposes. Their ease of culturing and their high growth rates further promote their use as raw material for the production of specialty products. In the present paper, we focused our attention on specific glycerol-based lipid compounds, monoacylglycerols (MAGs), which displayed in our previous studies a selective cytotoxic activity against the haematological U-937 and the colon HCT-116 cancer cell lines. Here, we performed a quali/quantitative analysis of MAGs and total fatty acids (FAs) along with a profiling of the main lipid classes in a panel of 12 microalgal species, including diatoms and dinoflagellates. Our results highlight an inter- and intraspecific variability of MAG profile in the selected strains. Among them, Skeletonema marinoi (strain FE7) has emerged as the most promising source for possible biotechnological production of MAGs.

Phytochemical characterization and multifaceted bioactivity assessment of essential oil from Clinopodium nepeta subsp. ascendens: potential for the food and pharmaceutical sectors

ABSTRACT This study delves into the biological characteristics of Clinopodium nepeta subsp. ascendens (CNEO) essential oil, an indigenous subspecies of eastern Morocco. Distinguished by its purple or pale pinkish-white flowers, CNEO was subjected to thorough phytochemical analysis via gas chromatography-mass spectrometry (GC-MS), revealing 21 terpene compounds, notably Dihydrocarvone (22.70%), Neoisomenthol (43.59%), and Pulegone (20.55%). These compounds, recognized for their biological and pharmacological attributes, were further investigated for their potential applications. Notably, CNEO exhibited dose-dependent anti-inflammatory effects by attenuating nitric oxide (NO) and prostaglandin E2 (PGE2) production. Moreover, it demonstrated promising anticancer activity against MDA-MB-468, HepG2, and HCT-15 cancer cell lines, rivaling doxorubicin’s effectiveness. These findings underscore CNEO’s nutraceutical potential, particularly in food science and industry, suggesting its use as a functional food additive with both nutritional and health benefits

Synthesis and in vitro antitumor evaluation of new thieno[2,3-d]pyrimidine derivatives as EGFR and DHFR inhibitors

New thienopyrimidine derivatives 2–16 have been synthesized and their in vitro cytotoxicity was evaluated against five different human cancer cell lines HCT-116, Hela, MDA-MB-231, MCF7 and PC3. Compounds 6e, 7a, 7b, 7d, 10c and 10e displayed the highest antitumor activity against all tested cell lines compared to Doxorubicin. Enzyme inhibition assay revealed that compounds 6e and 10e showed high inhibitory activity against EGFR-TK, with IC50 values of 0.133 and 0.151 µM, compared to Olmutinib (IC50 = 0.028 µM); while the highest DHFR inhibitory activity was shown by compounds 7d and 10e with IC50 values of 0.462 and 0.541 µM, compared to Methotrexate (IC50 = 0.117 µM). Cell cycle analysis following a flow cytometric study using colorectal HCT-116 cancer cell line proved that compound 6e induced cell cycle arrest in G0-G1 phase, while compound 10e arrested the cell cycle at both G0-G1 and S phases. Additionally, both compounds (6e and 10e) were potently able to induce apoptosis in HCT-116 cell line. Docking results of compounds 6e and 10e into the pocket of EGFR active site showed their similar main binding features with Olmutinib, while compounds 7d and 10e showed only moderate fitting into DHFR compared to methotrexate. In silico studies revealed that most of the tested compounds obeyed Lipinski’s RO5 and showed positive drug likeness scores.

Ultrasound-assisted synthesis of novel Schiff bases from 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxaldehyde and their cytotoxicity, apoptosis, cell cycle, molecular docking, and ADMET profiling

With the ultimate goal of discovering new anticancer agents, this study involved the design and synthesis of fifteen novel Schiff bases 4a,b, 5, 6a–d, 7a–e, and 8–10 which contain 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole moiety. The synthetic method depended on reaction of 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxaldehyde (3) with a series of aromatic and heteroaryl amines under ultrasound irradiation to explore the influence of aromatic and heteroaryl rings on biological activity. The chemical structures of these Schiff bases were fully elucidated using various spectral and elemental analyses. The antiproliferative activities of the Schiff bases were studied by the standard SRB method. Among the new 15 Schiff bases, derivatives 4a,b, 5, and 7b have significant cytotoxic effects against PC3, HepG2, and HCT116 cancer cell lines. These four bioactive Schiff bases significantly increased the late apoptosis of all studied tumor cells. Also, both products 4a and 4b arrested the cell cycle at the G1 phase, while both compounds 5 and 7b arrested the S and G2 phases against PC3 cells. In addition, the products 4a, 4b, 5, and 7b have promising high abilities to arrest the cell cycle at the G2 phase against HepG2 and HCT116 cells. The different substitutions on the aryl ring were the basis for the structure–activity relationship study. The molecular docking study confirmed good binding interactions of these compounds with Cyclin-dependent kinase 8 (CDK-8) receptor, while the absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction supported that these bioactive products can be promising anticancer agents.

Three new nonenes from culture broth of marine-derived fungus Albifimbria verrucaria and their cytotoxic and anti-viral activities.

Three new nonenes, verrucanonenes A‒C (1‒3), were isolated from culture broth of marine-derived fungus Albifimbria verrucaria. These compounds were isolated using silica gel column chromatography, reversed-phase medium pressure liquid chromatography, Sephadex LH-20 column chromatography, and preparative HPLC. Their structures were determined using a spectroscopic method. Cytotoxicities of these isolated compounds to A549, DU145, HCT116, and HT1080 cancer cell lines were assessed. Compounds 1‒3 exhibited cytotoxicities to DU145 cancer cell line, with IC50 values of 23.4, 28.6, and 20.1 µM, respectively. Compound 2 decreased H1N1-induced cytopathic effects on MDCK cells in a dose-dependent manner.

Cytotoxic activity and mechanism of action of Smp43 scorpion peptide against colorectal cancer cell line HCT-116

This study was conducted to extend our previous investigations to examine the cytotoxic efficacy of Smp43 scorpion peptide against colorectal cancer cell line (HCT-116) and revealing its molecular mechanisms of action. Using MTT assay, Smp43 significantly induced cytotoxic effects on HCT-116 cancer cells compared to normal colon epithelial cell line (FHC) of IC50 4.11 and 62.17 µg/ml, respectively. Flow cytometric apoptosis assay showed that IC50 (4.11 µg/ml) of Smp43 induced a remarkable increase in the proportion of HCT-116 cancer cells undergoing late apoptotic cell death. Also, Smp43 caused cell cycle arrest at the S phase. RT-PCR analysis showed highly significant downregulation of Bcl-2 anti-apoptotic gene and ki-67 proliferative markers in HCT-116 treated with IC50 of Smp43. In contrast, caspase-3, −8, −9, Bax, and p53 apoptotic genes were upregulated. Protein expression levels of caspase-3, −8, −9, and p53 were similarly elevated in treated cells using a western blot analysis. The apoptotic characteristics were also confirmed through scanning and transmission electron microscopy. The Smp43 treated HCT-116 cancer cells showed cell membrane blebbing, pore formation, heterochromatin condensation toward the nuclear envelope, leakage of cell organelles, and formation of apoptotic bodies. Consequently, Smp43 peptide provides a great starting point for creating effective cytotoxic agents against human colorectal cancer.

Mitochondria-Selective Dicationic Small-Molecule Ligand Targeting G-Quadruplex Structures for Human Colorectal Cancer Therapy.

Mitochondria are important drug targets for anticancer and other disease therapies. Certain human mitochondrial DNA sequences capable of forming G-quadruplex structures (G4s) are emerging drug targets of small molecules. Despite some mitochondria-selective ligands being reported for drug delivery against cancers, the ligand design is mostly limited to the triphenylphosphonium scaffold. The ligand designed with lipophilic small-sized scaffolds bearing multipositive charges targeting the unique feature of high mitochondrial membrane potential (MMP) is lacking and most mitochondria-selective ligands are not G4-targeting. Herein, we report a new small-sized dicationic lipophilic ligand to target MMP and mitochondrial DNA G4s to enhance drug delivery for anticancer. The ligand showed marked alteration of mitochondrial gene expression and substantial induction of ROS production, mitochondrial dysfunction, DNA damage, cellular senescence, and apoptosis. The ligand also exhibited high anticancer activity against HCT116 cancer cells (IC50, 3.4 μM) and high antitumor efficacy in the HCT116 tumor xenograft mouse model (∼70% tumor weight reduction).

Novel Tetracyclic Azaphenothiazines with the Quinoline Ring as New Anticancer and Antibacterial Derivatives of Chlorpromazine.

Phenothiazine derivatives are widely studied in various fields such as biology, chemistry, and medicine research because of their pharmaceutical effects. The first compound used successfully in the treatment of psychosis was a phenthiazine derivative, chlorpromazine. Apart from its activity in neurons, chlorpromazine has also been reported to display anticancer and antibacterial properties. In this study, we present the synthesis and research on the activity of A549, MDA, MiaPaCa, PC3, and HCT116 cancer cell lines and of S. aureus, S. epidermidis, E. coli, and P. aeruginosa bacterial strains against a series of new tetracyclic chlorpromazine analogues containing a quinoline scaffold in their structure instead of the benzene ring and various substituents at the thiazine nitrogen. The structure of these novel molecules has been determined by 1H NMR, 13C NMR, and HRMS spectral techniques. The seven most active of the twenty-four new chlorpromazine analogues tested were selected to study the mechanism of cytotoxic action. Their ability to induce apoptosis or necrosis in cancer cells was assessed by flow cytometry analysis. The results obtained confirmed the proapoptotic activity of selected compounds, especially in terms of inducing late apoptosis or necrosis in cancer cell lines A549, MiaPaCa-2, and HCT-116. Furthermore, studies on the induction of cell cycle arrest suggest that the new chlorpromazine analogues exert antiproliferative effects by inducing cell cycle arrest in the S phase and, consequently, apoptosis.

Decreasing the ability of HCT116 cells to escape from therapy induced senescence by increasing the duration of doxorubicin treatment

Contacts: Maria Anatolievna Zamkova zamkovam@gmail.com Introduction. Due to the toxicity of high doses of chemotherapy, low concentrations used in cancer treatment leads to the development of senescence phenotype in tumor cells, characterized by a block in the cell cycle progression and the absence of division; changes in the transcriptional and metabolic profile of cells. A negative consequence of this stage is acquisition of individual cells the ability to escape from senescence and return to re-proliferation.Aim. To estimate the effect of the duration of drug treatment of HCT116 tumor cells on their ability to escape from therapy induced senescence.Materials and methods. The senescence phenotype was confirmed by the analysis of β-galactosidase activity; cell cycle analysis; estimation of protein levels by western blotting. Colonies were stained with crystal violet dye.Results. In our study, we showed that the duration of HCT116 cells incubation with low-dose doxorubicin affects their ability to return to re-proliferation – increasing the treatment time using same drug dose reduces the process of colony formation. The duration of doxorubicin treatment does not affect the formation of the senescence phenotype, which was confirmed by analyzing different markers of this stage (changes in β-galactosidase activity, cell cycle analysis, assessment of p21 and γH2AX protein levels). However, there is a delay in the development of cellular response to DNA damage caused by doxorubicin in cells exposed to prolong treatment protocol (increase in β-galactosidase activity, formation of polyploid cells).Conclusion. The duration of doxorubicin treatment of HCT116 cancer cells affects long-term consequences, reducing the ability of senescent cells to escape this stage when the incubation time with the drug is extended.

Assessment of the cytotoxic effect of carboxymethyl chitosan-loaded amygdalin nanoparticles against human normal and cancer cell lines

In recent years, the development of antitumor drugs has been dedicated to natural products. Amygdalin is a natural herbal cyanoglycoside that has anticarcinogenic effect on many types of cancers once hydrogen cyanide (HCN) is released. The main objective of the present study is to synthesize and investigate the potential of carboxymethyl chitosan nanoparticles (CMC NPs) as drug delivery agents for amygdalin encapsulation and its delivery to cancer and normal cell lines. In this study, carboxymethyl chitosan nanoparticles encapsulated with amygdalin (CMC-Am NPs) were prepared and characterized through their particle size, surface charge, chemical structure and dielectric properties. Also, the invitro drug release of amygdalin from CMC NPs was studied. Additionally, the cytotoxcity of the amygdalin and CMC-loaded amygdalin NPs were evaluated through MTT assay. The results showed that the prepared CMC-loaded amygdalin NPs exhibited a small particle size of 129 nm, high zeta potential value of − 43 mV and confirmed the amygdalin stability and compatibility with CMC NPs. Furthermore, the CMC NPs demonstrated sustained release of amygdalin during 24 h. Moreover, compared to free amygdalin, amygdalin-loaded CMC NPs have significant anti-cancerous effect on human colon HCT-116 and breast MCF-7 cancer cell lines while being safe on normal cells BJ1. In conclusion, CMC NPs can be employed as an efficient drug delivery vehicle for controlled and sustained amygdalin release with enhanced cytotoxicity on malignant cells without harming normal cells.

Evaluation of poly(2-hydroxyethyl methacrylate) and poly(N-hydroxyethyl acrylamide) cryogels as potential quercetin release matrices

Fabrication of a suitable drug delivery system forms an attractive strategy to overcome the low bioavailability of quercetin. Poly(2-hydroxyethyl methacrylate–co-N-hydroxyethyl acrylamide), P(HEMA-co-HEAA) copolymer samples, and homopolymers of 2-hydroxyethyl methacrylate (PHEMA) and N-hydroxyethyl acrylamide (PHEAA) offer potential as quercetin delivery matrices owing to their favorable properties rendered in this study. Free radical polymerization applied under cryogenic conditions produced the polymer gels. The homopolymers and copolymers are noncytotoxic, porous, soft cryogels with surfaces resistant to protein and HCT-116 cancer cell adhesion. In vitro, quercetin release studies from samples reveal swelling-controlled, zero-order drug release at pH = 7.4 and 37 °C with high cumulative release percentages ranging from 92.03% to 94.82%. The durability of the cryogels and limited quercetin release at pH = 2.0 indicate that these cryogels are promising matrices for successfully delivering quercetin to the small intestine, where its primary absorption occurs.

Antioxidant Activity and Antitumor Potential of Hedyotis chrysotricha Extract in Human Colorectal Cancer and Breast Cancer Cell Lines

Background: Cancer is a serious disease severely endangering human health and life in the world in the world, and conventional anticancer drugs have frequently suffered from severe side effects and resistance. Therefore, developing novel and effective therapeutic strategies is urgently needed. As a Chinese herbal medicine with important medical values, Hedyotis chrysotricha has been suggested to be useful for the treatment of many diseases, especially cancer. Objective: Our aim was to investigate the antioxidant and antitumor activities of the phytochemical extracts of H. chrysotricha. Methods: 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay was applied to determine antioxidant property. 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide assay, wound healing assay, transwell matrix assay, flow cytometry and cell morphology were established to observe anti-proliferative, anti-migration, anti-invasion and apoptosis induction effects. The intracellular reactive oxygen species generation was detected by reactive oxygen species detection assay. Results: The ethyl acetate fraction showed promising antioxidant activity with IC50 of 98.67±0.49 μg/ml, and petroleum ether fraction exhibited the most potent antiproliferative effect on various human cancer cell lines, especially MDA-MB-231 (IC50 = 8.90±1.23 μg/ml) and HCT-116 (IC50 = 9.69±3.69 μg/ml) cancer cells. Further investigation revealed that the petroleum ether fraction suppressed the proliferation, migration and invasion of the cancer cells significantly. Additionally, it promoted cell apoptosis by increasing reactive oxygen species levels. Conclusion: H. chrysotricha extract possessed excellent antioxidant and antitumor activities. Therefore, it could be useful as a source of antioxidants and compounds for cancer therapy.

Synthesis of Cycloartan-16β-ol from 16β 24R-Epoxy-Cycloartane and Their Cytotoxicity Evaluation Against Human Cancer Cell Lines.

It was found that Argentatins A and B triterpenoids make up approximately 20-30 % of the waste resin produced from the industrial processes to isolate rubber from P. argentatum. We have developed an efficient protocol for synthesizing cycloartane-16β-ol derivatives by opening the oxepane ring of argentatin B acetate (2) with BF3-OEt2. Although three new cycloartenol derivatives showed high cytotoxicity against PC-3 and HCT-15 cancer cell lines, nevertheless, the best results were obtained for (16β,24R) -(16,24-epoxy-cycloartan-2(1H)-ylidene) acetate (14), compound with intact oxepane ring. These results indicate that the substituents in the argentatin nucleus and a side chain account for the cytotoxic activity. However, according to the selectivity index (SI), 14 did not show selectivity activity to cancer cell lines over the HaCat noncancerous cell line. The compound 3β,16β-Dihydroxy-cycloartan-24-one (5), synthesized by oxepane opening, demonstrated high cytotoxic activity to cancer cell lines and showed a remarkable selectivity to cancer cell lines over the noncancerous ones. These results suggest that 5 could lead to the development of new anticancer compounds.

Enhanced bacterial cancer therapy delivering therapeutic RNA interference of c-Myc

BackgroundBacterial cancer therapy was first trialled in patients at the end of the nineteenth century. More recently, tumour-targeting bacteria have been harnessed to deliver plasmid-expressed therapeutic interfering RNA to a range of solid tumours. A major limitation to clinical translation of this is the short-term nature of RNA interference in vivo due to plasmid instability. To overcome this, we sought to develop tumour-targeting attenuated bacteria that stably express shRNA by virtue of integration of an expression cassette within the bacterial chromosome and demonstrate therapeutic efficacy in vitro and in vivo.ResultsThe attenuated tumour targeting Salmonella typhimurium SL7207 strain was modified to carry chromosomally integrated shRNA expression cassettes at the xylA locus. The colorectal cancer cell lines SW480, HCT116 and breast cancer cell line MCF7 were used to demonstrate the ability of these modified strains to perform intracellular infection and deliver effective RNA and protein knockdown of the target gene c-Myc. In vivo therapeutic efficacy was demonstrated using the Lgr5creERT2Apcflx/flx and BlgCreBrca2flx/flp53flx/flx orthotopic immunocompetent mouse models of colorectal and breast cancer, respectively. In vitro co-cultures of breast and colorectal cancer cell lines with modified SL7207 demonstrated a significant 50–95% (P < 0.01) reduction in RNA and protein expression with SL7207/c-Myc targeted strains. In vivo, following establishment of tumour tissue, a single intra-peritoneal administration of 1 × 106 CFU of SL7207/c-Myc was sufficient to permit tumour colonisation and significantly extend survival with no overt toxicity in control animals.ConclusionsIn summary we have demonstrated that tumour tropic bacteria can be modified to safely deliver therapeutic levels of gene knockdown. This technology has the potential to specifically target primary and secondary solid tumours with personalised therapeutic payloads, providing new multi-cancer detection and treatment options with minimal off-target effects. Further understanding of the tropism mechanisms and impact on host immunity and microbiome is required to progress to clinical translation.