YOLO and residual network for colorectal cancer cell detection and counting

The HT-29 cell line, derived from human colon cancer, is valuable for biological and cancer research applications. Early detection is crucial for improving the chances of survival, and researchers are introducing new techniques for accurate cancer diagnosis. This study introduces an efficient deep learning-based method for detecting and counting colorectal cancer cells (HT-29). The colorectal cancer cell line was procured from a company. Further, the cancer cells were cultured, and a transwell experiment was conducted in the lab to collect the dataset of colorectal cancer cell images via fluorescence microscopy. Of the 566 images, 80 % were allocated to the training set, and the remaining 20 % were assigned to the testing set. The HT-29 cell detection and counting in medical images is performed by integrating YOLOv2, ResNet-50, and ResNet-18 architectures. The accuracy achieved by ResNet-18 is 98.70 % and ResNet-50 is 96.66 %. The study achieves its primary objective by focusing on detecting and quantifying congested and overlapping colorectal cancer cells within the images. This innovative work constitutes a significant development in overlapping cancer cell detection and counting, paving the way for novel advancements and opening new avenues for research and clinical applications. Researchers can extend the study by exploring variations in ResNet and YOLO architectures to optimize object detection performance. Further investigation into real-time deployment strategies will enhance the practical applicability of these models.

Exploring the Bioactive Potential of Calostoma insigne, an Endangered Culinary Puffball Mushroom, from Northeastern Thailand

Calostoma insigne puffball mushrooms are only found in forests with rich biodiversity in very few countries including Thailand, and their biofunctions remain largely unexplored. This study used the agar disk diffusion assay, the anti-glucosidase assay, and the 3, 4, 5-dimethylthiazol-2-yl-2-5-diphenyltetrazolium bromide (MTT) assay to evaluate the bioactive potential of these endangered puffball mushrooms. Internal transcribed spacer (ITS) gene analysis identified C. insigne, a puffball mushroom with green, globose, and spiny spores. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the polysaccharide structure while scanning electron microscopy (SEM) revealed a fiber-like network. The ethanolic gelatinous fruiting body extract exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging capacity (57.96%), a ferric ion-reducing antioxidant power (FRAP) value of 1.73 mg FeSO4/g, and α-glucosidase inhibition (73.18%). C. insigne cytotoxicity was effective towards HT-29 colon cancer cells using the MTT assay (IC50 of 770.6 µg/mL at 72 h) and also showed antiproliferative capacity (IC50 of 297.1 µg/mL). This puffball mushroom stimulated apoptotic genes and proteins (caspase-3, Bax, and p21) via an intrinsic apoptotic pathway in HT-29 cells. In the laboratory, the medium formula consisting of 20% potato, 2% sucrose, and 0.2% peptone was optimal to increase fungal mycelial biomass (2.74 g DW/100 mL), with propagation at pH 5.0 and 30 °C. Puffball mushrooms are consumed as local foods and also confer several potential health benefits, making them worthy of conservation for sustainable utilization.

Chlorogenic acid induces apoptosis and cell-cycle arrest in colorectal cancer cells

BACKGROUND

Apoptotic agents from natural products like phenolic compounds can be used effectively in the treatment of cancer. Chlorogenic acid (CGA) is one of the phenolic compounds in medicinal plants with anti-cancer properties. In this research, we aimed to explore the anti-cancer mode of action of CGA on colorectal cancer (CRC) cells in vitro conditions.

METHODS

HT-29 and HEK-293 cells were cultured after MTT assay for 24 h with CGA 100 µM, and without CGA. Then, flow cytometry assays and the expression of apoptosis-related genes including caspase 3 and 9, Bcl-2 and Bax, and cell cycle-related genes including P21, P53 and NF-κB at mRNA and protein levels were examined. Finally, we measured the amount of intracellular reactive oxygen species (ROS).

RESULTS

The cell viability of all two-cell lines decreased in a dose-dependent manner. Moreover, CGA induces cell cycle arrest in HT-29 cells by increasing the expression of P21 and P53. It also induces apoptosis in HT-29 cells by mitigating Bcl-2 and NF-κB expression and elevating caspase 3 and 9 expression and ROS levels.

CONCLUSIONS

Considering the cytotoxicity and cell cycle arrest and induction of apoptosis in the colon cancer cell line by CGA, it can be concluded that CGA is a suitable option for the treatment of colon cancer.

Evaluation of SgK269 expression in colon cancer patients and the effects of hAMSCs secretome on tumor invasion through SgK269/c-Src/p-P130Cas/p-Paxillin/p-ERK1/2 signaling pathway in HT-29 colon cancer cells

Colon cancer is the fifth leading cause of cancer-related deaths worldwide. Stem cells have unique characteristics and are considered as a novel therapeutic platform for cancer. Sugen Kinase 269 (SgK269) is considered as an oncogenic scaffolding pseudo kinase which governs the rearranging of the cytoskeleton, cellular motility, and invasion. The aim of this study is to evaluate the expression of SgK269 in colon cancer patients and explore the therapeutic effects of human amniotic mesenchymal stromal cells (hAMSCs) on invasion and proliferation of colon cancer cells (HT-29) through analyzing SgK269/c-Src/p-P130Cas/p-Paxillin/p-ERK1/2 signaling pathway. In this regard, we collected 30 samples from colon cancer patients and evaluated SgK269 expression using quantitative real-time PCR (qRT-PCR). Next, we employed a co-culture system using Transwell 6-well plates and after 72 h, tumor growth promotion and invasion were analyzed in hAMSCs-treated HT-29 cells through SgK269/c-Src/p-P130Cas/p-Paxillin/p-ERK1/2/Rac signaling pathway using qRT-PCR, western blot method, MTT assay, wound healing assay, and DAPI staining. Our results showed upregulation of SgK269 in colon cancer patients. Treatment of HT-29 colon cancer cells with hAMSCs secretome can inhibit SgK269/c-Src/p-P130Cas/p-Paxillin/p-ERK1/2/Rac signaling pathway and the resulting suppression of cell invasion and proliferation. Our results suggest that SgK269 is an important target in colon cancer therapy and MSCs secretome may be an effective therapeutic approach to inhibit colon cancer cell invasion and proliferation through SgK269/c-Src/p-P130Cas/p-Paxillin/p-ERK1/2/Rac signaling pathway.

Piper nigrum Extract Inhibits the Growth of Human Colorectal Cancer HT-29 Cells by Inducing p53-Mediated Apoptosis

Colorectal cancer (CRC) is a prevalent malignancy of the digestive tract with the second highest mortality rate globally. Piper nigrum is a widely used traditional medicinal plant, exhibiting antitumor activity against various tumor cells. At present, research on the effect of Piper nigrum on CRC is limited to in vitro cytotoxicity, lacking comprehensive mechanism investigations. This study aimed to explore the inhibitory effect and mechanism of Piper nigrum extract (PNE) on HT-29 cells. Firstly, we identified the chemical components of PNE. Then, MTT assay, colony formation assay, JC-1 staining, and flow cytometry were used to analyze the effect of PNE on HT-29 cells in vitro. A xenograft model, histopathological examination, immunohistochemistry, and western blot were used to evaluate the tumor growth inhibitory activity and mechanism of PNE in vivo. The results indicated that PNE could inhibit cell proliferation and colony formation, reduce mitochondrial membrane potential, induce cell apoptosis in vitro, and inhibit tumor growth in vivo. Furthermore, PNE could regulate p53 and its downstream proteins, and subsequently activate the caspase-3 pathway. In summary, PNE probably induced apoptosis of HT-29 cells through the mitochondrial pathway mediated by p53. All these results suggested that PNE might be a potential natural-origin anti-CRC drug candidate.

Isorhamnetin Influences the Viability, Superoxide Production and Interleukin-8 Biosynthesis of Human Colorectal Adenocarcinoma HT-29 Cells In Vitro

Isorhamnetin has gained research interest for its anti-inflammatory, anti-proliferative and chemoprotective properties. In this study, human colon adenocarcinoma cells were cultured in the presence or absence of different isorhamnetin concentrations (5-150 μM) for 24 h or 48 h of cultivation to explore the impact on several parameters of viability/proliferation (mitochondrial function using an MTT test, metabolic activity, cell membrane integrity and lysosomal activity using a triple test). The intracellular generation of superoxide radicals using an NBT test and ELISA analysis was performed to observe the biosynthesis of interleukin 8 (IL-8) in cells stimulated with zymosan, as well as in basal conditions. The antiproliferative activity of isorhamnetin was demonstrated by significantly reduced values of mitochondrial and metabolic activity, integrity of cell membranes and lysosomal activity. Its high prooxidant potential was reflected by the significantly elevated generation of superoxides even in cells with low viability status. The anti-inflammatory effect of isorhamnetin was evident due to decreased IL-8 production, and the most significant decline in IL-8 concentration was observed after 24 h treatment in cells with induced inflammation. We demonstrated that isorhamnetin can suppress the proliferation of HT-29 cells, and this effect was correlated with pro-oxidative and anti-inflammatory activity of isorhamnetin.

Wild Asparagus Shoots Constitute a Healthy Source of Bioactive Compounds

Wild Asparagus shoots are consumed worldwide, although most species remain understudied. In this work, a total of four wild Asparagus species were collected from different locations and analyzed compared with farmed A. officinalis. Shoots were screened for (i) phenolic compounds by HPLC-DAD and LC-MS; (ii) total phenolic acids and total flavonoid content by the Folin-Ciocalteu and aluminum chloride methods; (iii) vitamin C by HPLC-DAD; (iv) antioxidant activity by the DPPH and ABTS•+ methods; and (v) the in vitro antiproliferative activities against HT-29 colorectal cancer cells by the MTT assay. Phenolics ranged from 107.5 (A. aphyllus) to 605.4 mg/100 g dry weight (dw) (A. horridus). Vitamin C ranged from 15.8 (A. acutifolius) to 22.7 mg/100 g fresh weight (fw) (A. officinalis). The antioxidant activity was similar in all species, standing out in A. officinalis with 5.94 (DPPH) and 4.64 (ABTS) mmol TE/100 g dw. Among phenolics, rutin reached the highest values (574 mg/100 g dw in A. officinalis), followed by quercetin, nicotiflorin, asterin, and narcissin. The MTT assay revealed the inhibitory effects of ethanol extracts against HT-29 cancer cells, highlighting the cell growth inhibition exercised by A. albus (300 µg/mL after 72 h exposure to cells). This work improves knowledge on the phytochemicals and bioactivities of the shoots of wild Asparagus species and confirms their suitability for use as functional foods.

Bacterial extracellular vesicles induced oxidative stress and mitophagy through mTOR pathways in colon cancer cells, HT-29: Implications for bioactivity

Bacterial-extracellular-vesicles (BEVs) derived from Escherichia coli, strain-A5922, were used as a therapeutic tool to treat colon cancer cells, HT-29. BEVs induced oxidative stress, and observed mitochondrial autophagy, known as mitophagy, were crucial in initiation of treatment. The mitophagy, induced by the BEVs in HT-29 cells, produced adenocarcinomic cytotoxicity, and stopped the cells growth. The trigger for mitophagy, and an increase in productions of reactive oxygen species led to cellular oxidative stress, that eventually led to cells death. A reduction in the mitochondrial membrane potential, and an increase in the PINK1 expressions confirmed the oxidative stress involvements. The BEVs triggered cytotoxicity, and mitophagy in the HT-29 carcinoid cells, channelized through the Akt/mTOR pathways connecting the cellular oxidative stress, effectively played its part to cause cells death. These findings substantiated the BEVs' potential as a plausible tool for treating, and possibly preventing the colorectal cancer.

paracasei X12 Strain Induces Apoptosis in HT-29 Cells through Activation of the Mitochondrial Pathway

L. paracasei subsp. paracasei X12 was obtained from traditional cheese produced in northwestern China. In this study, we showed that whole peptidoglycan (WPG), extracted from L. paracasei subsp. paracasei X12, inhibited proliferation and induced apoptosis in HT-29 cells in a dose-dependent manner. In addition, WPG-induced apoptosis was associated with the loss of mitochondrial membrane potential (Ψm), the release of cytochrome c (Cyto-C) from mitochondrialto cytosolic spaces, activation of Caspase 3, and accumulation of intracellular reactive oxygen species (ROS). Finally, semi-quantitative RT-PCR showed that these events were accompanied by upregulation of proapoptotic genes (Bax or Bad) and downregulation of antiapoptotic genes (Bcl-xl). Taken together, our results demonstrated that WPG induced apoptosis in HT-29 cells through activation of the mitochondrial pathway. WPG exerted only minor toxicity upon noncancerous cells and therefore might be used as a natural agent in the treatment of cancer in future.

Recombinant Escherichia coli BL21 with LngA Variants from ETEC E9034A Promotes Adherence to HT-29 Cells

The CS21 pilus produced by enterotoxigenic Escherichia coli (ETEC) is involved in adherence to HT-29 intestinal cells. The CS21 pilus assembles proteins encoded by 14 genes clustered into the lng operon.

AIM

This study aimed to determine whether E. coli BL21 (ECBL) transformed with the lng operon lacking the lngA gene (pE9034AΔlngA) and complemented in trans with lngA variants of ETEC clinical strains, as well as point substitutions, exhibited modified adherence to HT-29 cells.

METHODS

A kanamycin cassette was used to replace the lngA gene in the lng operon of the E9034A strain, and the construct was transformed into the ECBL strain. The pJET1.2 vector carrying lngA genes with allelic variants was transformed into ECBLpE9034AΔlngA (ECBLΔlngA). The point substitutions were performed in the pJETlngA_FMU073332 vector.

RESULTS

Bioinformatic alignment analysis of the LngA proteins showed hypervariable regions and clustered the clinical ETEC strains into three groups. Variations in amino acid residues affect the adherence percentages of recombinant ECBL strains with lngA variants and site-specific mutations with HT-29 cells.

CONCLUSION

In this study, ECBL carrying the lng operon harboring lngA variants of six clinical ETEC strains, as well as point substitutions, exerted an effect on the adherence of ECBL to HT-29 cells, thereby confirming the importance of the CS21 pilus in adherence.

Probiotic potential of β‑galactosidase‑producing lactic acid bacteria from fermented milk and their molecular characterization

Probiotics have attained significant interest in recent years as a result of their gut microbiome modulation and gastrointestinal health benefits. Numerous fermented foods contain lactic acid bacteria (LAB) which are considered as GRAS and probiotic bacteria. The present study aimed to investigate indigenous LAB from homemade fermented milk samples collected in remote areas of Karnataka (India), in order to isolate the most potent and well-adapted to local environmental conditions bacteria, which were then evaluated using a step-by-step approach focused on the evaluation of probiotic traits and β-galactosidase-producing ability. LAB were screened using 5-bromo-4-chloro-3-indole-D-galactopyranoside (X-Gal) and O-nitrophenyl-β-D-galactopyranoside (ONPG) as substrate, and exhibited β-galactosidase activity ranging from 728.25 to 1,203.32 Miller units. The most promising isolates were selected for 16S rRNA gene sequence analysis and identified as Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Lactiplantibacillus pentosus and Lactiplantibacillus sp. Furthermore, these isolates were evaluated by in vitro, viz., survival in gastrointestinal tract, antibiotic susceptibility, antimicrobial activity, cell surface characteristics, and haemolytic activity. All eight isolates demonstrated strong adherence and prevented pathogen penetration into HT-29 cells, indicating potential of the bacteria to scale up industrial level production of milk products for lactose intolerants.

Anti-rotavirus Properties and Mechanisms of Selected Gram-Positive and Gram-Negative Probiotics on Polarized Human Colonic (HT-29) Cells

Probiotics have been investigated to improve the universal rotavirus (RV) vaccination as well as to ameliorate the RV infection. However, underlying mechanisms how probiotics mediate beneficial effects needs more investigation. Thus, in the present study, we used polarized HT-29 cells to assess the anti-RV properties of Gram-positive, (Lactobacillus acidophilus, Lacticaseibacillus rhamnosus GG, and Bifidobacterium subsp. Lactis Bb12) and Gram negative, (Escherichia coli Nissle 1917) probiotics and study their underlying mechanisms. Our results showed that pre-treatment of HT-29 cells for 4 h with probiotics, significantly reduced (p < 0.05) human RV replication and this effect was most pronounced for E. coli Nissle followed by L. acidophilus and L. rhamnosus GG. Strikingly, only pre-treatment with live bacteria or their supernatants demonstrated anti-RV properties. Except Gram negative E. coli Nissle, the Gram-positive probiotics tested did not bind to RV. Ingenuity pathway analysis of tight junction (TJ)- and innate immune-associated genes indicated that E. coli Nissle or E. coli Nissle + RV treatments improved cell-cell adhesion and cell contact, while L. acidophilus or L. acidophilus + RV treatments also activated cell-cell contact but inhibited cell movement functions. RV alone inhibited migration of cells event. Additionally, E. coli Nissle activated pathways such as the innate immune and inflammatory responses via production of TNF, while RV infection activated NK cells and inflammatory responses. In conclusion, E. coli Nissle's ability to bind RV, modulate expression of TJ events, innate immune and inflammatory responses, via specific upstream regulators may explain superior anti-RV properties of E. coli Nissle. Therefore, prophylactic use of E. coli Nissle might help to reduce the RV disease burden in infants in endemic areas.

Arecaceae Seeds Constitute a Healthy Source of Fatty Acids and Phenolic Compounds

Seeds of most Arecaceae species are an underutilized raw material that can constitute a source of nutritionally relevant compounds. In this work, seeds of 24 Arecaceae taxa were analyzed for fatty acids (FAs) by GC-FID, for phenolics by HPLC-DAD and LC-MS, and for their antitumor activity against the HT-29 colorectal cancer cell line by the MTT assay. Lauric, oleic, and linoleic acids were the prominent FAs. Cocoseae species contained total FAs at 28.0-68.3 g/100 g seeds, and in other species total FAs were from 1.2 (Livistona saribus) to 9.9 g/100 g (Washingtonia robusta). Sabal domingensis, Chamaerops humilis, and Phoenix dactylifera var. Medjool had unsaturated/saturated FA ratios of 1.65, 1.33-1.78, and 1.31, respectively, and contained 7.4, 5.5-6.3, and 6.4 g FAs/100 g seeds, respectively. Thus, they could be used as raw materials for healthy oilseed production. Phenolics ranged between 39 (Livistona fulva) and 246 mg/100 g (Sabal palmetto), and of these, caffeic acid, catechin, dactylifric acid, and rutin had the highest values. (-)-Epicatechin was identified in most seed extracts by LC-MS. Hydroalcoholic extracts from five species showed a dose-dependent inhibitory effect on HT-20 cells growth at 72 h (GI₅₀ at 1533-1968 µg/mL). Overall, Arecaceae seeds could be considered as a cheap source of health-promoting compounds.

Transcriptional responses of human intestinal epithelial HT-29 cells to spore-displayed p40 derived from Lacticaseibacillus rhamnosus GG

BACKGROUNDS

The aims of this study were to construct spore-displayed p40, a Lacticaseibacillus rhamnosus GG-derived soluble protein, using spore surface display technology and to evaluate transcriptional responses in human intestinal epithelial cells.

RESULTS

p40 was displayed on the surface of Bacillus subtilis spores using spore coat protein CotG as an anchor protein. Effects of spore-displayed p40 (CotG-p40) on gene expression of intestinal epithelial cell line HT-29 were evaluated by transcriptome analysis using RNA-sequencing. As a result of differentially expressed gene (DEG) analysis, 81 genes were up-regulated and 82 genes were down-regulated in CotG-p40 stimulated cells than in unstimulated cells. Gene ontology enrichment analysis showed that CotG-p40 affected biological processes such as developmental process, metabolic process, cell surface receptor linked signaling pathway, and retinoic acid metabolic process. Gene-gene network analysis suggested that 10 DEGs (EREG, FOXF1, GLI2, PTGS2, SPP1, MMP19, TNFRSF1B, PTGER4, CLDN18, and ALDH1A3) activated by CotG-p40 were associated with probiotic action.

CONCLUSIONS

This study demonstrates the regulatory effects of CotG-p40 on proliferation and homeostasis of HT-29 cells. This study provided comprehensive insights into the transcriptional response of human intestinal epithelial cells stimulated by CotG-p40.

Surface layer protein A from hypervirulent Clostridioides difficile ribotypes induce significant changes in the gene expression of tight junctions and inflammatory response in human intestinal epithelial cells

Background

Surface layer protein A (SlpA), the primary outermost structure of Clostridioides difficile, plays an essential role in C. difficile pathogenesis, although its interaction with host intestinal cells are yet to be understood. The aim of this study was to investigate the effects of SlpA extracted from C. difficile on tight junction (TJ) proteins expression and induction of pro-inflammatory cytokines in human colon carcinoma cell line HT-29. SlpA was extracted from three toxigenic C. difficile clinical strains including RT126, RT001, RT084 as well as C. difficile ATCC 700057 as non-toxigenic strain. Cell viability was performed by MTT assay, and the mRNA expression of TJ proteins and inflammation-associated genes was determined using quantitative RT-PCR. Additionally, the secretion of IL-8, IL-1β and TNF-α cytokines was measured by ELISA.

Results

C. difficile SlpA from selected RTs variably downregulated the expression level of TJs-assassinated genes and increased the expression level of TLR-4 and pro-inflammatory cytokines in HT-29 treated cells. SlpA from RT126 significantly (p_adj<0.05) decreased the gene expression level of claudins family and JAM-A and increased the secretion of IL-8, TNF-α and IL1-β as compared to untreated cells. Moreover, only SlpA from RT001 could significantly induce the expression of IL-6 (p_adj<0.05).

Conclusion

The results of the present study highlighted the importance of SlpA in the pathogenesis of CDI and C. difficile-induced inflammatory response in the gut. Further studies are required to unravel the significance of the observed results in promoting the intestinal inflammation and immune response induced by C. difficile SlpA from different RTs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02665-0.

Potential effects of fructus aurantii ethanol extracts against colitis-associated carcinogenesis through coordination of Notch/NF-κB/IL-1 signaling pathways

Colitis-associated cancer (CAC) is the colorectal cancer (CRC) subtype that is difficult to treat, and shows high mortality. The consumption of flavonoid-rich fructus aurantii extracts (FAE) has been associated with multiple beneficial effects including anti-inflammatory and anti-cancer properties, but the potential effects on the colitis-associated carcinogenesis have not been thoroughly investigated. Recent clinical data show that, as yet, few agents clearly inhibited CRC development in long-standing inflammatory bowel diseases. Here, we identified that FAE showed significant efficiency to inhibit HT-29 cell proliferation. The potential of FAE in vivo was further evaluated in an AOM/DSS-induced CAC mouse model. Intriguingly, FAE diminished the number of polyps in mice. Furthermore, FAE inhibited CAC by regulating the gene expression of Notch/ NF-κB/IL-1 signaling pathways. Collectively, these results were indicative of FAE has great potential in CAC prevention and treatment.

The Effect of Avidin on Viability and Proliferation of Colorectal Cancer Cells HT-29

Objective:

The aim of this study was to analyze the effect of avidin treatment on cell viability, proliferation and cyclin D1 expression in colorectal cancer cells HT-29.

Methods:

Colorectal cancer cell line HT-29 incubated with 50, 100, 150, and 200 μg/mL of avidin concentration during 24, 48, and 72 hours, then the cell viability and proliferation were analyzed. Each avidin concentration was conducted together with HT-29 cell line without avidin treatment as a control group. The cell viability was measured by MTS assay and the proliferation was measured by BrdU (5-bromo-2′-deoxyuridine) cell proliferation assay. According to cell viability and proliferation result, we determined the 100 μg/mL avidin concentration for analyzing mRNA and protein of cyclin D1.

Results:

We demonstrated that the viability and proliferation of HT-29 cells were significantly decreased in all concentration of avidin treatment compared to control. The cell proliferation showed larger reduction in avidin treatment rather than cell viability. This proves avidin could inhibit proliferation of colorectal cancer cell HT-29 quite well. The expression of cyclin D1, both mRNA and protein, was also significantly decreased after the avidin treatment group compared to control group, it supports the suppression of proliferation result.

Conclusion:

We concluded that avidin treatment could decrease cell viability and proliferation, accompanied by suppression of cyclin D1 expression in colorectal cells HT-29.

Enhanced Growth Inhibition and Apoptosis Induction in Human Colon Carcinoma HT-29 Cells of Soluble Longan Polysaccharides with a Covalent Chemical Selenylation

The selenylated polysaccharides chemically belong to the organic Se-conjugated macromolecules and have recently been attracting more and more attention due to their potential to promote body health or prevent cancers. Longan (Dimocarpus longan L.), as a subtropical fruit, contains soluble and non-digestible polysaccharides that are regarded with health care functions in the body. In this study, the longan polysaccharides (LP) were obtained via enzyme-assisted water extraction, and then chemically selenylated using a reaction system composed of HNO₃–Na₂SeO₃ to yield two selenylated products, namely, SeLP1 and SeLP2, with Se contents of 1.46 and 4.79 g/kg, respectively. The anti-cancer effects of the three polysaccharide samples (LP, SeLP1, and SeLP2) were thus investigated using the human colon cancer HT-29 cells as the cell model. The results showed that SeLP1 and SeLP2 were more able than LP to inhibit cell growth, alter cell morphology, cause mitochondrial membrane potential loss, increase intracellular reactive oxygen and [Ca²⁺]_i levels, and induce apoptosis via regulating the eight apoptosis-related genes and proteins including Bax, caspases-3/-8/-9, CHOP, cytochrome c, DR5, and Bcl-2. It was thereby proven that the selenylated polysaccharides could induce cell apoptosis via activating the death receptor, mitochondrial-dependent, and ER stress pathways. Collectively, both SeLP1 and SeLP2 showed higher activities than LP in HT-29 cells, while SeLP2 was consistently more active than SeLP1 in exerting these assessed anti-cancer effects on the cells. In conclusion, this chemical selenylation covalently introduced Se into the polysaccharide molecules and caused an enhancement in their anti-cancer functions in the cells, while higher selenylation extent was beneficial to the activity enhancement of the selenylated products.

Immuno-modulatory effect of probiotic E. coli Nissle 1917 in polarized human colonic cells against Campylobacter jejuni infection

Campylobacter jejuni is among the leading causes of bacterial foodborne illness. Poultry is the major reservoir and source of human campylobacteriosis. Currently, there is no effective and practical method to decrease C. jejuni colonization in chickens or to reduce human infections. Additionally, antibiotic-resistant infections pose a serious public health concern; therefore, antibiotic-alternative approaches are needed to reduce transmission of C. jejuni including resistant bacteria from chickens to humans. Here, we evaluated the effect of E. coli Nissle 1917 (EcN) on innate responses of polarized HT-29 cells and consequently on C. jejuni 81176 infections in HT-29 cells. Pre-treatment of HT-29 cells with EcN for 4 h had a significant effect on the invasion of different C. jejuni strains (2 h post-infection) (P < .05) and no intracellular C. jejuni (24 h post-infection) were recovered. To further understand how EcN mediates its impact on C. jejuni's survival inside the cells, we used Human Antibacterial RT² Profiler^TM PCR arrays to profile gene expression in HT-29 cells after treatment with EcN with or without C. jejuni 81-176 infection. Our results suggest that pre-treatment of the HT-29 cells with EcN induced the anti-inflammatory cytokines and activated the anti-apoptotic Akt signaling which likely to protect the cells against the proinflammatory and apoptosis responses induced by C. jejuni. EcN also positively affected the expression of genes involved in cellular maintenance, growth, development, and proliferation. Further, EcN modulated the expression of genes involved in protective innate immunity, such as TLRs, ERK1/2, p38 MAPK, Ap1, JNK, IL1B, IL17A, and NF-κB signaling.

Benzo(a)pyrene-induced cytotoxicity, cell proliferation, DNA damage, and altered gene expression profiles in HT-29 human colon cancer cells

In the US alone, around 60,000 lives/year are lost to colon cancer. In order to study the mechanisms of colon carcinogenesis, in vitro model systems are required in addition to in vivo models. Towards this end, we have used the HT-29 colon cancer cells, cultured in Dulbecco's Modified Eagle Medium (DMEM), which were exposed to benzo(a)pyrene (BaP), a ubiquitous and prototypical environmental and dietary toxicant at 1, 10, 100 nM and 1, 5, 10, and 25 μM concentrations for 96 h. Post-BaP exposure, growth, cytotoxicity, apoptosis, and cell cycle changes were determined. The BaP metabolite concentrations in colon cells were identified and measured. Furthermore, the BaP biotransformation enzymes were studied at the protein and mRNA levels. The BaP exposure-induced damage to DNA was assessed by measuring the oxidative damage to DNA and the concentrations of BaP-DNA adducts. To determine the whole repertoire of genes that are up- or downregulated by BaP exposure, mRNA transcriptome analysis was conducted. There was a BaP exposure concentration (dose)-dependent decrease in cell growth, cytotoxicity, and modulation of the cell cycle in the treatment groups compared to untreated or dimethylsulfoxide (DMSO: vehicle for BaP)-treated categories. The phase I biotransformation enzymes, CYP1A1 and 1B1, showed BaP concentration-dependent expression. On the other hand, phase II enzymes did not exhibit any marked variation. Consistent with the expression of phase I enzymes, elevated concentrations of BaP metabolites were generated, contributing to the formation of DNA lesions and stable DNA adducts, which were also BaP concentration-dependent. In summary, our studies established that biotransformation of BaP contributes to cytotoxicity, proliferation of tumor cells, and alteration of gene expression by BaP. • Benzo(a)pyrene (BaP) is an environmental and dietary toxicant. • BaP causes cytotoxicity in cultured HT-29 colon cancer cells. • mRNA transcriptome analyses revealed that BaP impacts cell growth, cell cycle, biotransformation, and DNA damage.

TRAIL Conjugated Silver Nanoparticle Synthesis, Characterization and Therapeutic Effects on HT-29 Colon Cancer Cells

Colon cancer is one of the most prominent causes of cancer-related morbidity and mortality and curable if detected in the early stages. TNF-related apoptosis-inducing ligand (TRAIL) is a therapeutic protein and has a potential anti-cancer activity that is widely used for the treatment of several cancers. In this study, we aimed to develop a silver nanoparticle system conjugated with TRAIL and coated with PEG (AgCTP NPs) to improve the therapeutic effects of colon cancer. AgCTP NPs were characterized by UV spectrum, FTIR and zetasizer. Cytotoxicity, hemolysis assay and apoptotic effects of nanoparticles were investigated using a colon cancer cell line (HT-29) in-vitro. Treatment with AgCTP NPs effectively inhibited proliferation and colony formation of HT-29 cells. The apoptotic effects of nanoparticles on HT-29 cells were determined as Bax, Bcl-2, PARP and clv-PARP protein expression levels using Western blot. Apoptotic proteins were upregulated by AgCTP NPs. In this study, we demonstrated that AgCTP NPs had an anti-cancer effect by activating cell death. Thus, we have confirmed that silver nanoparticles can be selected as a good carrier for TRAIL therapeutic proteins that can be used to treat colon cancer.

Cell-Free Lactobacillus casei 21L10 Modulates Nitric Oxide Release and Cell Proliferation/Cell Death in Lipopolysaccharide-Challenged HT-29 Cells

Lactobacillus casei (L. casei) is one of the probiotic strains that may influence intestinal injury and inflammation in nonspecific intestinal diseases. We aimed to evaluate the effect of cell-free Lactobacillus casei 21L10 supernatant (LC) on the cell line HT-29 challenged with lipopolysaccharide (LPS) in order to modulate production of NO, cell proliferation, and apoptosis. Cell line HT-29 was stimulated with LPS in the presence or absence of LC. Our results showed that LC from L. casei 21L10 did not affect the viability of unstimulated HT-29 cells line. HT-29 cell line treatment with LC caused significant decrease of LPS induced NO production after 3 h, and 24 h, but not after 48 h. Proliferation activity of LPS stimulated HT-29 cell line analysed with MTT assay significantly decreased after 24 h and 48 h, but not after 3 h. The majority of LPS stimulated HT-29 cell line treated with LC showed annexin V/PI positivity at 48 h survival, which corresponded to late apoptotic/necrotic cell features. The observed differences suggest that cell-free L. casei 21L10 supernatant could participate in attenuation of LPS-induced inflammation, and may exhibit anti-proliferative and pro-apoptotic/necrotic effects. This study provides pilot data for the further development of L. casei exoproducts as an anti-inflammatory or anti-proliferative agent for the treatment of inflammatory and cancer diseases in gut. However, more data is needed before final conclusions of L. casei cell-free supernatant's efficacy can be drawn.

Diterpenoids Isolated from Podocarpus macrophyllus Inhibited the Inflammatory Mediators in LPS-Induced HT-29 and RAW 264.7 Cells

Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest pain, arthritis, rheumatism, and sexually transmitted diseases. To identify natural products having efficacy against inflammatory bowel disease (IBD), we identified a new, 16-hydroxy-4β-carboxy-O-β-D-glucopyranosyl-19-nor-totarol (4) together with three known diterpenoids from P. macrophyllus. Furthermore, all the extracts, fractions, and isolates 1–4 were investigated for their anti-inflammatory effects by assessing the expression on nitric oxide (NO) production and proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 and HT-29 cells. Among them, nagilactone B (2) exhibited a potent anti-inflammatory effect against NO production on RAW 264.7 cells; therefore, nagilactone B was further assessed for anti-inflammatory activity. Western blot analysis revealed that nagilactone B significantly decreased the expression of LPS-stimulated protein, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and phosphorylated extracellular regulated kinase (pERK)1/2. In addition, nagilactone B downregulated tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 levels in LPS-induced macrophages and colonic epithelial cells. To our best knowledge, this is the first report on the inhibitory effect of nagilactone B (pure state) and rakanmakilactone G against NO production in LPS-stimulated RAW 264.7 cells. Thus, diterpenoids isolated from P. macrophyllus could be employed as potential therapeutic phytochemicals for IBD.

Clostridium butyricum Induces the Production and Glycosylation of Mucins in HT-29 Cells

C. butyricum is a common gut commensal bacterium, which has many positive functions in human intestine. In this study, we investigated the effects of monosaccharide and its derivatives on the adhesion of C. butyricum to the mucus of HT-29 cells. RNA interference was performed to assess the roles of MUC2 and glycan in the adhesion of C. butyricum to HT-29 cells. The effects of C. butyricum on the glycosylation of mucins were assayed with fluorescence microscope. The expression levels of mucins and glycotransferases were also determined. The results showed that C. butyricum could adhere to the mucins secreted by HT-29 cells. Several kinds of monosaccharides inhibited the adhesion of C. butyricum to HT-29 cells, which suggested that the mucus glycan was the attaching sites of this bacterium. Knockdown of MUC2, FUT2 or GALNT7 significantly decreased the numbers of the bacteria adhering to HT-29 cells. When colonizing on the surface of HT-29 cells, C. butyricum could increase the production of mucins, promote the expression of glycotransferase, and induce the glycosylation of mucins. These results demonstrated that the glycan of mucus played important roles in the adhesion of C. butyricum to HT-29 cells. This study indicates for the first time that C. butyricum possesses the ability to modulate the glycosylation profile of mucus secreted by HT-29 cells. These findings contribute to understanding the mechanism of interaction between colonic epithelial cells and commensal bacteria.

A Polylactosamine-Specific Lectin From Adenia Hondala Induces Apoptosis And Necrosis In Human Epithelial Colon Cancer Ht-29 Cells

BACKGROUND

Altered expression of N-glycans such as polylactosamine is observed in colon cancer. AHL, a polylactosamine specific lectin from Adenia hondala from a medicinal plant from the Passifloraceae family, has been reported earlier.

OBJECTIVE

The aim of the present study is to study the interaction of AHL with human colon cancer epithelial HT-29 cells and colon cancer tissues.

METHODS

Cell viability was determined by MTT [3-[4, 5- dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide] assay, while cell surface binding and apoptosis by Annexin-V-PI assay. ROS production was analyzed using DCFDA [2',7' - dichlorofluorescindiacetate] kit method by flow cytometry. Immunohistochemistry was performed using biotinylated AHL and protein purification by affinity chromatography using asialofetuin-coupled Sepahrose -4B column.

RESULTS

AHL strongly binds to HT-29 cells with a Mean Fluorescence Intensity of 12.4, which could be blocked by competing for glycoprotein asialofetuin. AHL inhibits HT-29 cell growth in a dose and time-dependent manner with IC50 of 2.5µg/ml and differentially binds to human normal and cancerous tissues. AHL induces apoptosis and slight necrosis in HT-29 cells, increasing the early apoptotic population by 25.1% and 36% for 24 h and 48h, respectively, and necrotic population by 1.5% and 4.6 % at 24h and 48h, respectively, as revealed by Annexin-V-PI assay. AHL induces the release of Reactive Oxygen Species in HT-29 cells in a dose-dependent manner.

CONCLUSION

To the best of knowledge, this is the first report on lectin from Adenia hondala, which is not a RIP with apoptotic and necrotic effect. These findings support the promising potential of AHL in cancer research.

Rosmarinic acid inhibits migration, invasion, and p38/AP-1 signaling via miR-1225-5p in colorectal cancer cells

Elucidating the molecular mechanism of the migration and invasion is critical for identifying novel therapeutic targets and may significantly improve the prognosis of colorectal cancer. Emerging evidence suggests an involvement of dysregulated microRNAs in the process of tumorigenesis. Here, we show that miR-1225-5p prevents migration and invasion of colorectal cancer cells. Overexpression of miR-1225-5p significantly decreases the expression of Matrix Metalloproteases (MMPs)-1, 3, and 9. Knockdown of miR-1225-5p elevates ROS level via regulating Keap1/Nrf2 pathway. Furthermore, miR-1225-5p attenuates IL-17A-induced p38/AP-1-signaling pathway by suppressing IL-17RA expression. We also examined the biological effects of Rosmarinic acid (RA) on metastatic colorectal cancer cells. RA inhibited EMT via the p38/AP-1 signaling, and miR-1225-5p is essential for RA-mediated anti-metastatic effects.

Native Chilean Berries Preservation and In Vitro Studies of a Polyphenol Highly Antioxidant Extract from Maqui as a Potential Agent against Inflammatory Diseases

The best conservation method for native Chilean berries has been investigated in combination with an implemented large-scale extract of maqui berry, rich in total polyphenols and anthocyanin to be tested in intestinal epithelial and immune cells. The methanolic extract was obtained from lyophilized and analyzed maqui berries using Folin–Ciocalteu to quantify the total polyphenol content, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) to measure the antioxidant capacity. Determination of maqui’s anthocyanins profile was performed by ultra-high-performance liquid chromatography (UHPLC-MS/MS). Viability, cytotoxicity, and percent oxidation in epithelial colon cells (HT-29) and macrophages cells (RAW 264.7) were evaluated. In conclusion, preservation studies confirmed that the maqui properties and composition in fresh or frozen conditions are preserved and a more efficient and convenient extraction methodology was achieved. In vitro studies of epithelial cells have shown that this extract has a powerful antioxidant strength exhibiting a dose-dependent behavior. When lipopolysaccharide (LPS)-macrophages were activated, noncytotoxic effects were observed, and a relationship between oxidative stress and inflammation response was demonstrated. The maqui extract along with 5-aminosalicylic acid (5-ASA) have a synergistic effect. All of the compiled data pointed out to the use of this extract as a potential nutraceutical agent with physiological benefits for the treatment of inflammatory bowel disease (IBD).

Synthesis and Anticancer Evaluation of New 1,3,4-Oxadiazole Derivatives

In order to develop novel chemotherapeutic agents with potent anticancer activities, a series of new 2,5-diaryl/heteroaryl-1,3,4-oxadiazoles were designed and synthesized. The structures of the new compounds were established using elemental analyses, IR and NMR spectral data. The compounds were evaluated for their anticancer potential on two standardized human cell lines, HT-29 (colon adenocarcinoma) and MDA-MB-231 (breast adenocarcinoma). Cytotoxicity was measured by MTS assay, while cell cycle arrest and apoptosis assays were conducted using a flow cytometer, the results showing that the cell line MDA-MB-231 is more sensitive to the compounds' action. The results of the predictive studies using the PASS application and the structural similarity analysis indicated STAT3 and miR-21 as the most probable pharmacological targets for the new compounds. The promising effect of compound 3e, 2-[2-(phenylsulfanylmethyl)phenyl]-5-(4-pyridyl)-1,3,4-oxadiazole, especially on the MDA-MB-231 cell line motivates future studies to improve the anticancer profile and to reduce the toxicological risks. It is worth noting that 3e produced a low toxic effect in the D. magna 24 h assay and the predictive studies on rat acute toxicity suggest a low degree of toxic risks.

HDAC8 Activates AKT through Upregulating PLCB1 and Suppressing DESC1 Expression in MEK1/2 Inhibition-Resistant Cells

Inhibition of the RAF-MEK1/2-ERK signaling pathway is an ideal strategy for treating cancers with NRAS or BRAF mutations. However, the development of resistance due to incomplete inhibition of the pathway and activation of compensatory cell proliferation pathways is a major impediment of the targeted therapy. The anthrax lethal toxin (LT), which cleaves and inactivates MEKs, is a modifiable biomolecule that can be delivered selectively to tumor cells and potently kills various tumor cells. However, resistance to LT and the mechanism involved are yet to be explored. Here, we show that LT, through inhibiting MEK1/2-ERK activation, inhibits the proliferation of cancer cells with NRAS/BRAF mutations. Among them, the human colorectal tumor HT-29 and murine melanoma B16-BL6 cells developed resistance to LT in 2 to 3 days of treatment. These resistant cells activated AKT through a histone deacetylase (HDAC) 8-dependent pathway. Using an Affymetrix microarray, followed by qPCR validation, we identified that the differential expression of the phospholipase C-β1 (PLCB1) and squamous cell carcinoma-1 (DESC1) played an important role in HDAC8-mediated AKT activation and resistance to MEK1/2-ERK inhibition. By using inhibitors, small interference RNAs and/or expression vectors, we found that the inhibition of HDAC8 suppressed PLCB1 expression and induced DESC1 expression in the resistant cells, which led to the inhibition of AKT and re-sensitization to LT and MEK1/2 inhibition. These results suggest that targeting PLCB1 and DESC1 is a novel strategy for inhibiting the resistance to MEK1/2 inhibition.

Light-responsive polymeric nanoparticles based on a novel nitropiperonal based polyester as drug delivery systems for photosensitizers in PDT

Although nanoparticles (NPs) bear a great potential in tumour therapy, just a few nanosized drug delivery systems are commercially available. Besides their advantages like passive drug targeting and stable embedment of lipophilic active pharmaceutical ingredients, targeted drug release is a major challenge for a safe therapy. While drug release of commonly used materials depends on physiological factors, nanoparticles prepared by using stimuli responsive polymers offer a promising approach. External irradiation of light-sensitive nanoparticles enables local drug release, resulting in selective accumulation and consequently more effective treatment with less side effects. In this study light-responsive nanoparticles based on a new innovative light-responsive polyester (Nip-SLrPE) combined with poly(DL-lactide-co-glycolide) (PLGA) were prepared and examined for their physicochemical characteristics and light-triggered properties. As model drug the photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl)chlorine (mTHPC) was incorporated and light-depending drug release was investigated. Furthermore, cytotoxic potential of selected formulations for PDT and intracellular accumulation of mTHPC were evaluated. In conclusion, nanoparticles based on the new light-sensitive Nip-SLrPE showed auspicious light-responsive properties, resulting in promising results for a smart drug delivery system.

MicroRNA In Situ Hybridization in Paraffin-Embedded Cultured Cells

MicroRNA-21 (miR-21) is one of the most abundant microRNAs in cancer tissues and is considered a strong prognostic biomarker. In situ hybridization (ISH) analyses using locked nucleic acid (LNA) probes have shown that miR-21 is expressed in stromal fibroblastic cells and in subsets of cancer cells. Image analysis of the miR-21 ISH signal has shown that increased expression estimate is associated with poor prognosis in colon cancer. However, assessment of the ISH signal by image analysis to obtain quantitative estimates has been done in retrospective studies without normalization of the expression estimates to reference parameters. The ISH signal output is sensitive to several experimental parameters, including hybridization temperature, probe concentration, and pretreatment, and therefore improved standardized procedures are warranted. We considered the use of paraffin-embedded cultured cells (PECCs) as reference standards that potentially can accompany staining of clinical cancer samples. We found that the cancer cell lines HT-29, CACO-2, and HeLa cells express miR-21 when measured by ISH, and used those cell lines to obtain PECCs. In this methods chapter we present a fixation and embedding procedure to obtain PECCs suitable for microRNA ISH and a double-fluorescence protocol to stain microRNAs together with protein markers in the PECCs.

Genotoxic and Cytotoxic Properties of Zinc Oxide Nanoparticles Phyto-Fabricated from the Obscure Morning Glory Plant Ipomoea obscura (L.) Ker Gawl

The study was undertaken to investigate the antioxidant, genotoxic, and cytotoxic potentialities of phyto-fabricated zinc oxide nanoparticles (ZnO-NPs) from Ipomoea obscura (L.) Ker Gawl. aqueous leaf extract. The UV-visible spectral analysis of the ZnO-NPs showed an absorption peak at 304 nm with a bandgap energy of 3.54 eV, which are characteristics of zinc nanoparticles. Moreover, the particles were of nano-size (~24.26 nm) with 88.11% purity and were agglomerated as observed through Scanning Electron Microscopy (SEM). The phyto-fabricated ZnO-NPs offered radical scavenging activity (RSA) in a dose-dependent manner with an IC50 of 0.45 mg mL-1. In addition, the genotoxicity studies of ZnO-NPs carried out on onion root tips revealed that the particles were able to significantly inhibit the cell division at the mitotic stage with a mitotic index of 39.49%. Further, the cytotoxic studies on HT-29 cells showed that the phyto-fabricated ZnO-NPs could arrest the cell division as early as in the G0/G1 phase (with 92.14%) with 73.14% cells showing early apoptotic symptoms after 24 h of incubation. The results of the study affirm the ability of phyto-fabricated ZnO-NPs from aqueous leaf extract of I. obscura is beneficial in the cytotoxic application.

Comparison of content-toxicity-activity of six ingenane-type diterpenoids between Euphorbia kansui before and after stir-fried with vinegar by using UFLC-MS/MS, zebrafish embryos and HT-29 cells

The dried roots of Euphorbia kansui (EK) are especially beneficial for the treatment of edema, but the severe toxicity limits their clinical applications. Euphorbia kansui stir-fried with vinegar (VEK) is traditionally employed to reduce the toxicity of EK. However, the material basis for the toxicity reduction with effectivity conservation is still unclear. Therefore, in this study, a rapid, sensitive, and reliable ultra-fast liquid chromatography tandem mass spectrometry (UFLC-MS/MS) method was firstly established to simultaneously determine six ingenane-type diterpenoids, i.e. kansuiphorin C (1), 5-O-benzoyl-20-deoxyingenol (2), 20-deoxyingenol (3), 3-O-(2'E,4'E-decadienoyl)-20-O-acetylingenol (4), 20-O-(2'E,4'Z-decadienoyl)ingenol (5), and ingenol (6), in EK and VEK based on the processing conversion. Then, the toxicity evaluation on zebrafish embryos and modulation of the expression of aquaporin-3 (AQP3) proteins in HT-29 cells were employed to investigate the toxicity-activity of six compounds. Chromatographic separation was obtained on Waters BEH RP18 column (2.1 mm × 100 mm, 2.5 μm) with the mobile phase composed of 0.1 % formic acid in acetonitrile and water, respectively. The column temperature was 35 ℃ at a flow rate of 0.4 mL min^-1. Multiple reaction monitoring was conducted in both positive and negative modes for quantitative analysis. The method was then successfully used for the determination of six compounds in EK and VEK. In addition, 1, 2, 4, and 5 had evident cardiotoxicity, intestinal irritation and nutrient absorption disorders on zebrafish larvae, while no in-vivo toxicity was seen for groups given 3 and 6 (LC₅₀ > 200 μM). Meanwhile, 1, 2, 4, 5, and 6 significantly increased the expression of AQP3 protein (p < 0.05) to promote the excretion of water in the colon. This study demonstrated that toxic ingenane-type diterpenoids converted into the less toxic compounds with the same core structure through the breakage of multiple ester bonds in the side chain. At the same time, the laxative effect was retained, providing useful information for the optimization of the process of EK and quality evaluation of other similar toxic Chinese herbal medicines.

Cytotoxicity, apoptosis, and IL-8 gene expression induced by some foodborne pathogens in presence of Bacillus coagulans in HT-29 cells

Food poisoning caused by bacteria is one of the most important concerns in food hygiene. The use of probiotics in prevention, control, and treatment of these infections has been considerably increased in recent years. This study evaluated the effect of B. coagulans cell free supernatant (CFS) on growth of Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, non-pathogenic Escherichia coli, and Escherichia coli 0157:H7 by the broth dilution method. The cytotoxicity, and apoptosis induced by pathogens alone and in co-culture with B. coagulans or its CFS were measured by trypan blue, and fluorescence staining methods. The expression level of interleukin-8 (IL-8) cytokine-encoding genes was also investigated by a qRT-PCR assay in all pathogens and co-cultured groups in HT-29 cells. Our results showed that 4% B. coagulans CFS reduced pathogen growth. The highest rate of growth inhibition was observed in L. monocytogenes. We also found that B. coagulans, and its 4% CFS reduced the cytotoxic effects of pathogens, with the exception of S. aureus. Non-pathogenic E. coli also had no significant cytotoxic effect on the cells. Examination of the treated cells with acridine orange/ethidium bromide staining showed reductions in the rate of cell damage (including early apoptosis, late apoptosis, and necrosis) in pathogen-probiotic co-cultures. Furthermore, we showed that co-culture of pathogens with B. coagulans significantly down-regulated IL-8 gene expression (P < 0.05). The greatest down-regulation compared with pathogen alone was observed in S. aureus. Hence, B. coagulans can be considered as an appropriate probiotic to diminish cytotoxicity, and inflammatory response of enteropathogenic bacteria.

Exposure to cadmium and copper triggers cytotoxic effects and epigenetic changes in human colorectal carcinoma HT-29 cells

Recent scientific evidence suggests a link between epigenetic changes (DNA methylation) and tumorigenesis. Moreover, a potential carcinogenic mechanism of cadmium was associated with changes in DNA methylation. In this study we investigated the impact of CdCl₂ and CuSO₄ aqueous solutions on DNA methylation in HT-29 cells by quantifying DNA methyltransferase (DNMT1, DNMT3A and DNMT3B) mRNA expression. Furthermore, we also studied the cytotoxic and anti-migratory potential of these substances. The results showed a dose-dependent decrease of viable cell percentage following 24 h of exposure (at concentrations of 0.05; 0.2; 1; 10 and 100 µg/ml), and an inhibitory effect on HT-29 cell migration capacity. In addition, RT-qPCR results showed that cadmium acts as a hypomethylating agent by suppressing DNMT expression, whereas copper acts as a hypermethylating compound by increasing DNMT expression. These findings suggest a cytotoxic potential of both cadmium and copper on HT-29 cells and their capacity to induce epigenetic changes.

High Concentrations of Aspartame Induce Pro-Angiogenic Effects in Ovo and Cytotoxic Effects in HT-29 Human Colorectal Carcinoma Cells

Aspartame (ASP), an artificial sweetener abundantly consumed in recent years in an array of dietary products, has raised some concerns in terms of toxicity, and it was even suggested a link with the risk of carcinogenesis (colorectal cancer), though the present scientific data are rather inconclusive. This study aims at investigating the potential role of aspartame in colorectal cancer by suggesting two experimental approaches: (i) an in vitro cytotoxicity screening in HT-29 human colorectal carcinoma cells based on cell viability (Alamar blue assay), cell morphology and cell migration (scratch assay) assessment and (ii) an in ovo evaluation in terms of angiogenic and irritant potential by means of the chorioallantoic membrane method (CAM). The in vitro results showed a dose-dependent cytotoxic effect, with a significant decrease of viable cells at the highest concentrations tested (15, 30 and 50 mM) and morphological cellular changes. In ovo, aspartame (15 and 30 mM) proved to have a pro-angiogenic effect and a weak irritant potential at the vascular level. These data suggest new directions of research regarding aspartame’s role in colorectal cancer.

Methylsulfonylmethane Induces Cell Cycle Arrest and Apoptosis, and Suppresses the Stemness Potential of HT-29 Cells

BACKGROUND/AIM

Colorectal cancer is one of the most common malignancies worldwide. Small molecule-based chemotherapy is an attractive approach for the chemoprevention and treatment of colorectal cancer. Methylsulfonylmethane (MSM) is a natural organosulfur compound with anticancer properties, as revealed by studies on in vitro models of gingival, prostate, lung, hepatic, and breast cancer. However, the molecular mechanisms underlying the effects of MSM in colon cancer cells remain unclear.

MATERIALS AND METHODS

Here, we investigated the effects of MSM, especially on the cell cycle arrest and apoptosis, in HT-29 cells.

RESULTS

MSM suppressed the viability of HT-29 cells by inducing apoptosis and cell cycle arrest at the G₀/G₁ phase. MSM suppressed the sphere-forming ability and expression of stemness markers in HT-29 cells.

CONCLUSION

MSM has anti-cancer effects on HT-29 cells, and induces cell cycle arrest and apoptosis, while suppressing the stemness potential.

Anti-cancer effects of Porphyra haitanensis polysaccharides on human colon cancer cells via cell cycle arrest and apoptosis without causing adverse effects in vitro

In this study, the anticancer effects of Porphyra haitanensis polysaccharides (PHPs) on human colon cancer cells and non-cancerous cells were evaluated. PHP was extracted by an ultrasonic/microwave-assisted method, and three fractions of polysaccharides (PHP-F1, PHP-F2 and PHP-F3) were obtained through a DEAE-52 cellulose ion-exchange column. The results of the cytotoxicity test showed that all of the PHP fractions had inhibitory effects on the growth of colon cancer cells HT-29, LoVo and SW-480, but no toxic effects on the normal human cells HaCaT. The fractions PHP-F2 and PHP-F3 had the most significant cytotoxicity on HT-29 cells. Studies on intracellular reactive oxygen species (ROS) levels, cell apoptosis, the apoptosis index (using Hoechst 33342 staining) and analysis of cell cycle arrest using flow cytometry revealed that the fractions PHP-F2 and PHP-F3 could apparently induce oxidative stress and apoptosis in HT-29 cells and cause cell G0-G1 phase arrest. These findings suggest that polysaccharides from P. haitanensis have anticancer effects on human colon cancer cells and therefore might be regarded as new candidates for the prevention and treatment of colon cancers.

Arachidonic acid induces ER stress and apoptosis in HT-29 human colon cancer cells

Polyunsaturated fatty acids (PUFAs) have important functions in biological systems. The beneficial effects of dietary PUFAs against inflammatory diseases, cardiovascular diseases, and metabolic disorders have been shown. Studies using cancer cells have presented the anti-tumorigenic effects of docosahexaenoic acid (DHA), an n-3 PUFA, while arachidonic acid (AA), an n-6 PUFA, has been shown to elicit both pro- and anti-tumorigenic effects. In the current study, the anti-tumorigenic effects of AA were evaluated in HT-29 human colon cancer cells. Upon adding AA in the media, more than 90% of HT-29 cells died, while the MCF7 cells showed good proliferation. AA inhibited the expression of SREBP-1 and its target genes that encode enzymes involved in fatty acid synthesis. As HT-29 cells contained lower basal levels of fatty acid synthase, a target gene of SREBP-1, than that in MCF7 cells, the inhibitory effects of AA on the fatty acid synthase levels in HT-29 cells were much stronger than those in MCF-7 cells. When oleic acid (OA), a monounsaturated fatty acid that can be synthesized endogenously, was added along with AA, the HT-29 cells were able to proliferate. These results suggested that HT-29 cells could not synthesize enough fatty acids for cell division in the presence of AA because of the suppression of lipogenesis. HT-29 cells may incorporate more AA into their membrane phospholipids to proliferate, which resulted in ER stress, thereby inducing apoptosis. AA could be used as an anti-tumorigenic agent against cancer cells in which the basal fatty acid synthase levels are low.

The Effects of Lactobacillus plantarum-12 Crude Exopolysaccharides on the Cell Proliferation and Apoptosis of Human Colon Cancer (HT-29) Cells

The exopolysaccharide (EPS) of some Lactobacillus strains has been reported to exert anti-cancer activities. In this study, the effects of crude EPSs produced by four Lactobacillus plantarum strains (Lactobacillus plantarum-12, L. plantarum-14, L. plantarum-32, and L. plantarum-37) on HT-29 cell proliferation and apoptosis were studied. The results showed that the inhibition rate of the crude EPS produced by L. plantarum-12 on HT-29 cell proliferation was significantly higher than that of the EPS produced by the other three strains. L. plantarum-12 crude EPS (50, 100, 250, 500 μg/ml) exerted inhibitory effects on the expression of proliferating cell nuclear antigen (PCNA) in HT-29 cells in a positive dose-dependent manner. The reactive oxygen species (ROS) level and apoptosis rate were also increased in HT-29 cells treated with different concentrations of L. plantarum-12 crude EPS compared with control cells. Further studies found that the expression of the pro-apoptotic proteins Bax, Cyt C, caspase-3, caspase-8 and caspase-9 was upregulated and that the expression of the anti-apoptosis protein Bcl-2 was decreased in HT-29 cells treated with L. plantarum-12 crude EPS compared with control cells. The results suggested that the EPS produced by L. plantarum-12 could inhibit the proliferation of the human colon cancer cell line HT-29 through the mitochondrial pathway.

Microwave-Assisted Synthesis of Potential Bioactive Benzo-, Pyrido- or Pyrazino-thieno[3,2-d]pyrimidin-4-amine Analogs of MPC-6827

Efficient microwave-assisted chemical processes were applied to the synthesis of an array of novel N-(4-methoxyphenylamino)-2-methyl benzo-, pyrido- or pyrazino-thieno[3,2-d]pyrimidin-4-amine derivatives. These heteroaromatic systems were envisioned as potent bioisosteric analogues of MPC-6827, an anticancer agent previously developed until phase II clinical studies. A brief evaluation and comparison of their antiproliferative activity on HT-29 and Caco-2, two human colorectal cancer cell lines, were also reported. At the tested concentrations (5 and 10 µM), thieno[3,2-d]pyrimidin-4-amines 4a and 4c exhibited an inhibitory effect similar to MPC-6827 on human colorectal cancer cell proliferation.

Evaluation of isoindole derivatives: Antioxidant potential and cytotoxicity in the HT-29 colon cancer cells

Norcantharimides have an isoindole skeleton structure, and some isoindoline derivatives have positive effects on inflammatory pathologies, including cancers. The present study aims to evaluate the antioxidant and cytotoxic potential of four synthesized isoindoline derivatives (NCTD1-4). HT-29 cells exposed to 10, 50, 100, and 200 µM doses of each derivative were incubated for 24 and 48 h, respectively. The cytotoxicity of the new derivatives was analyzed using the cell growth inhibition assay and the cell membrane damage test. In vitro antioxidant activity studies showed that the derivatives have free radical-scavenging effects in a dose-dependent manner. NCTD3 and NCTD4 apparently have antioxidant effects when compared with the control group treated with dimethyl sulfoxide. Furthermore, NCTD4 inhibited the growth of the HT-29 cells due to membrane damage and exhibited a dose-dependent cytotoxic effect on colon adenocarcinoma cells. The findings suggest that NDTD4 has the highest potential for colon cancer treatment and may be interpreted as a candidate anticancer agent.

Cytotoxic Effects of Cannabinoids on Human HT-29 Colorectal Adenocarcinoma Cells: Different Mechanisms of THC, CBD, and CB83

In this study, we investigated the effects of exposition to IC₅₀ dose for 24 h of a new synthetic cannabinoid (CB83) and of phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on HT-29 colorectal carcinoma cells. Cell viability and proliferative activity evaluated using the MTT, lactate dehydrogenase (LDH), and CyQUANT assays showed that cell viability was significantly affected when CB83, THC, and CBD were administered to cells. The results obtained showed that the reduced glutathione/oxidized glutathione ratio was significantly reduced in the cells exposed to CBD and significantly increased in the cells treated with the CB83 when compared to the controls. CBD treatment causes a significant increase in malondialdehyde content. The catalase activity was significantly reduced in HT-29 cells after incubation with CB83, THC, and CBD. The activities of glutathione reductase and glutathione peroxidase were significantly increased in cells exposed to THC and significantly decreased in those treated with CBD. The ascorbic acid content was significantly reduced in cells exposed to CB83, THC, and CBD. The ultrastructural investigation by TEM highlighted a significantly increased percentage of cells apoptotic and necrotic after CB83 exposition. The Annexin V-Propidium Iodide assay showed a significantly increased percentage of cells apoptotic after CB83 exposition and necrotic cells after CBD and THC exposition. Our results proved that only CBD induced oxidative stress in HT-29 colorectal carcinoma cells via CB receptor-independent mechanisms and that CB83 caused a mainly CB2 receptor-mediated antiproliferative effect comparable to 5-Fuorouracil, which is still the mainstay drug in protocols for colorectal cancer.

α-Linolenic and γ-linolenic acids exercise differential antitumor effects on HT-29 human colorectal cancer cells

α-Linolenic acid (ALA, 18:3n-3) and γ-gamma linolenic acid (GLA, 18:3n-6) are polyunsaturated fatty acids (PUFA) that improve the human health. The present study focused on testing the in vitro antitumor actions of pure ALA and GLA on the HT-29 human colorectal cancer cell line. Cell viability was checked by MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, cell membrane damage by the lactate dehydrogenase assay, apoptosis was tested by both caspase-3 activity trial and transmission electron microscopy images, and protein composition was analyzed by quantitative proteomics analysis. MTT test revealed IC₅₀ values of 230 and 255 μM for ALA and GLA, respectively, at 72 h. After 24 h of incubation, both ALA and GLA induced apoptosis on HT-29 colorectal cancer cells according to the caspase-3 assay and microscopy images. SWATH/MS analysis evidenced that ALA significantly affected the mitochondrial protein import pathway and the citric acid cycle pathway, while GLA did not significantly affect any particular pathway. In summary, both ALA and GLA showed concentration-dependent inhibitory effects on HT-29 cells viability and induced cell death by apoptosis. ALA significantly affected cellular pathways, while GLA does not have specific actions on either pathway. Both n-3 and n-6 C18 PUFA are bioactive food components useful in the colorectal cancer prevention.

Antibiofilm Activity of Lactobacillus plantarum 12 Exopolysaccharides against Shigella flexneri

In developing countries, Shigella flexneri is the most common enteric pathogen causing bacillary dysentery. Biofilm formation by S. flexneri can cause the emergence of antibiotic-resistant strains, which poses serious threats to food safety and human health. In this study, the effects of Lactobacillus plantarum 12 exopolysaccharides (L-EPSs) and S. flexneri exopolysaccharides (S-EPSs) on S. flexneri CMCC51574 biofilm formation were investigated. The results showed that L-EPS could decrease polysaccharide production in the extracellular polymeric matrix of S. flexneri and inhibit biofilm formation by S. flexneri L-EPS could decrease the minimum biofilm elimination concentration (MBEC) of antibiotics against S. flexneri biofilm and inhibit S. flexneri adhesion to and invasion into HT-29 cell monolayers, which might be ascribed to S. flexneri biofilm disturbance by L-EPS. In contrast, S-EPS exhibited the opposite effects compared to L-EPS. The monosaccharide composition analysis showed that L-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, galactose, and xylose, with the molar ratio of 32.26:0.99:1.79:5.63:0.05:4.07, while S-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, and galactose, with the molar ratio of 25.43:2.28:7.13:5.35. L-EPS was separated into the neutral polysaccharide L-EPS 1-1 and the acidic polysaccharide L-EPS 2-1 by ion-exchange chromatography and gel chromatography. L-EPS 2-1 exerted higher antibiofilm activity than L-EPS 1-1. The antibiofilm activity of L-EPS might be associated with its structure.IMPORTANCES. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the strain. In the present study, it was demonstrated that L-EPSs secreted by Lactobacillus plantrum 12 could inhibit S. flexneri biofilm formation on, adhesion to, and invasion into HT-29 cells. Also, L-EPSs could decrease the minimum biofilm elimination concentration (MBEC) of the antibiotics used against S. flexneri biofilm. Therefore, L-EPSs were shown to be bioactive macromolecules with the potential ability to act against S. flexneri infections.

A Whey Fraction Rich in Immunoglobulin G Combined with Bifidobacterium longum subsp. infantis ATCC 15697 Exhibits Synergistic Effects against Campylobacter jejuni

Evidence that whey proteins and peptides have health benefits beyond basic infant nutrition has increased dramatically in recent years. Previously, we demonstrated that a whey-derived immunoglobulin G-enriched powder (IGEP) enhanced adhesion of Bifidobacterium longum subsp. infantis ATCC 15697 (B. infantis) to HT-29 cells. In this study, we investigated the synergistic effect of IGEP-treated B. infantis on preventing the attachment of highly invasive Campylobacter jejuni 81–176 (C. jejuni) to intestinal HT-29 cells. The combination decreased the adherence of C. jejuni to the HT-29 cells by an average of 48% compared to the control (non-IGEP-treated B. infantis). We also confirmed that treatment of IGEP with sodium metaperiodate, which disables the biological recognition of the conjugated oligosaccharides, reduced adhesion of B. infantis to the intestinal cells. Thus, glycosylation of the IGEP components may be important in enhancing B. infantis adhesion. Interestingly, an increased adhesion phenotype was not observed when B. infantis was treated with bovine serum-derived IgG, suggesting that bioactivity was unique to milk-derived immunoglobulin-rich powders. Notably, IGEP did not induce growth of B. infantis within a 24 hours incubation period, as demonstrated by growth curves and metabolite analysis. The current study provides insight into the functionality of bovine whey components and highlights their potential in positively impacting the development of a healthy microbiota.

DNA damage and DNA protection from digested raw and griddled green pepper (poly)phenols in human colorectal adenocarcinoma cells (HT-29)

PURPOSE

To determine whether (poly)phenols from gastrointestinal-digested green pepper possess genoprotective properties in human colon cells and whether the application of a culinary treatment (griddling) on the vegetable influences the potential genoprotective activity.

METHODS

(Poly)phenols of raw and griddled green pepper (Capsicum annuum L.) submitted to in vitro-simulated gastrointestinal digestion were characterized by LC-MS/MS. Cytotoxicity (MTT, trypan blue and cell proliferation assays), DNA damage and DNA protection (standard alkaline and formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay) of different concentrations of (poly)phenolic extracts were assessed in colon HT-29 cells.

RESULTS

A total of 32 (poly)phenolic compounds were identified and quantified in digested raw and griddled green pepper. Twenty of them were flavonoids and 12 were phenolic acids. Griddled pepper doubled the (poly)phenol concentration compared to raw; luteolin 7-O-(2-apiosyl)-glucoside and quercitrin constituted the major (poly)phenols in both extracts. Raw and griddled pepper (poly)phenolic extracts impaired cell proliferation and induced low levels of Fpg-sensitive sites, in a dose-dependent manner, even at a non-cytotoxic concentration. None of the concentrations tested induced DNA strand breaks or alkaline labile sites. Nor did they show significant genoprotection against the DNA damage induced by H₂O₂ or KBrO₃.

CONCLUSIONS

Green pepper (poly)phenols did not show genoprotection against oxidatively generated damage in HT-29 cells at simulated physiological concentrations, regardless of the application, or not, of a culinary treatment (griddling). Furthermore, high concentrations of (poly)phenolic extracts induced a slight pro-oxidant effect, even at a non-cytotoxic concentration.

Tumor suppressor p53 independent apoptosis in HT-29 cells by auransterol from Penicillium aurantiacobrunneum

Colorectal cancer is the third leading cause of cancer related-death in the United States. Search for new alternatives to treat this type of cancer is necessary. In a previous report, auransterol from Penicillium aurantiacobrunneum showed cytotoxicity in HT-29 cancer cells. Thus, the goal of this study was to examine the potential cytotoxic mechanism of auransterol in HT-29 cells. Real-time cytotoxicity of auransterol was determined in HT-29 colon cancer cells, using the SRB assay. Loss of MTP, overproduction of ROS, cell cycle, cell migration, and caspase activity were analyzed. Western blot analysis was used to evaluate protein expression. Auransterol reduced cell proliferation rate in a time and concentration-dependent manner, with an IC₅₀ value > 100, 49.1 and 23.8 μM at 24, 48 and 72 h of treatment, respectively. After 24 h of treatment, 50 μM of auransterol induced loss of MTP, overproduction of ROS, increased caspase activity, induced cell cycle G₁ phase accumulation and inhibition of migration in HT-29 cells compared to control. These results were supported by protein upregulation of Cyt c, BAX, PARP-1, p21 and procaspase-3, and downregulation of Bcl-2 with no modifications in procaspase-7 and p53. The cytotoxic effect of auransterol in HT-29 colon cancer cells is mediated by mitochondrial apoptosis independent of p53 activation, cell cycle G₁ phase arrest, and inhibition of cell migration. This work encourages further preclinical and clinical studies of auransterol and suggests auransterol as a good candidate for colorectal cancer treatment.

Apoptotic-Induced Effects of Acacia Catechu Willd. Extract in Human Colon Cancer Cells

The research for innovative treatments against colon adenocarcinomas is still a great challenge. Acacia catechu Willd. heartwood extract (AC) has health-promoting qualities, especially at the gastrointestinal level. This study characterized AC for its catechins content and investigated the apoptosis-enhancing effect in human colorectal adenocarcinoma HT-29 cells, along with its ability to spare healthy tissue. MTT assay was used to describe the time course, concentration dependence and reversibility of AC-mediated cytotoxicity. Cell cycle analysis and AV-PI and DAPI-staining were performed to evaluate apoptosis, together with ROS formation, mitochondrial membrane potential (MMP) changes and caspase activities. Rat ileum and colon rings were tested for their viability and functionality to explore AC effects on healthy tissue. Quantitative analysis highlighted that AC was rich in (±)-catechin (31.5 ± 0.82 mg/g) and (−)-epicatechin (12.5 ± 0.42 mg/g). AC irreversibly decreased cell viability in a concentration-dependent, but not time-dependent fashion. Cytotoxicity was accompanied by increases in apoptotic cells and ROS, a reduction in MMP and increases in caspase-9 and 3 activities. AC did not affect rat ileum and colon rings’ viability and functionality, suggesting a safe profile toward healthy tissue. The present findings outline the potential of AC for colon cancer treatment.

Bifidobacterium longum subsp. infantis ATCC 15697 and Goat Milk Oligosaccharides Show Synergism In Vitro as Anti-Infectives against Campylobacter jejuni

Bifidobacteria are known to inhibit, compete with and displace the adhesion of pathogens to human intestinal cells. Previously, we demonstrated that goat milk oligosaccharides (GMO) increased the attachment of Bifidobacterium longum subsp. infantis ATCC 15697 to intestinal cells in vitro. In this study, we aimed to exploit this effect as a mechanism for inhibiting pathogen association with intestinal cells. We examined the synergistic effect of GMO-treated B. infantis on preventing the attachment of a highly invasive strain of Campylobacter jejuni to intestinal HT-29 cells. The combination decreased the adherence of C. jejuni to the HT-29 cells by an average of 42% compared to the control (non-GMO treated B. infantis). Increasing the incubation time of the GMO with the Bifidobacterium strain resulted in the strain metabolizing the GMO, correlating with a subsequent 104% increase in growth over a 24 h period when compared to the control. Metabolite analysis in the 24 h period also revealed increased production of acetate, lactate, formate and ethanol by GMO-treated B. infantis. Statistically significant changes in the GMO profile were also demonstrated over the 24 h period, indicating that the strain was digesting certain structures within the pool such as lactose, lacto-N-neotetraose, lacto-N-neohexaose 3′-sialyllactose, 6′-sialyllactose, sialyllacto-N-neotetraose c and disialyllactose. It may be that early exposure to GMO modulates the adhesion of B. infantis while carbohydrate utilisation becomes more important after the bacteria have transiently colonised the host cells in adequate numbers. This study builds a strong case for the use of synbiotics that incorporate oligosaccharides sourced from goat′s milk and probiotic bifidobacteria in functional foods, particularly considering the growing popularity of formulas based on goat milk.