Caco-2 Colorectal Cancer Cells Research Articles

Chemical composition, cytotoxic potential and antioxidant properties of Punica granatum peel extract

Purpose: To evaluate the antioxidant activity of pomegranate peel extract and its effects on the survival of colorectal cancer cells (Caco-2) and kidney cells (HEK293). Methods: An ethanol extract was prepared from the outer layer of pomegranate peels. The chemical composition of the extract was examined using high-performance liquid chromatography with diodearray detection (HPLC-DAD) and liquid chromatography with tandem mass spectrometry (LC-MS-MS). Antioxidant activity was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'- azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) assays. Cytotoxicity was tested against Caco-2 colorectal cancer cells and HEK293 normal kidney cells using MTT assay. Results: The pomegranate peel extract was rich in phenolic compounds and demonstrated significant antioxidant activity, with IC50 values comparable to Trolox in DPPH and ABTS assays. The extract exhibited selective and concentration-dependent cytotoxicity against Caco-2 cells, with an EC50 of 121.05 ± 13.12 µg/mL, while showing minimal toxicity towards HEK293 cells. Conclusion: Pomegranate peel extract's high phenolic content and potent antioxidant properties highlight its potential as a therapeutic agent against colorectal cancer. The findings suggest that this extract could serve as a viable, natural alternative with reduced toxicity for colorectal cancer treatment.

Multifunctional nanoplatforms based on alumina-coated mesoporous silica with potential for cancer theranostics applications

Multifunctional nanoplatforms based on mesoporous silica coated with alumina were successfully and sustainably synthesized using sodium silicate extracted from rice husk ash (RHA), demonstrating the potential for cancer theranostics. The hybrid nanostructures produced (C2-600 and C4-600), from two different calcination times, exhibited distinct morphologies, textural parameters, and degrees of mesoscopic organization. As expected, the Al2O3 coating on the mesoporous silica nanoparticles (MSNs) reduced the specific surface area from 720 m2/g to 122 m2/g (C2-600) and 57 m2/g (C4-600), while preserving their mesoporous structure. Additionally, both C2-600 and C4-600 showed relatively good stability across a wide pH interval, with a zeta potential of ζ = -15 mV and hydrodynamic diameter (Dh) ranging from 160 to 670 nm, depending on the pH of the medium. These peculiar characteristics resulted in high encapsulation efficiency (EE ≈ 90%) for the doxorubicin (DOX) anticancer drug, as well as sustained drug release in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.4). Appreciably, C4-600-DOX released approximately 83% of the drug over 96 hours and demonstrated significant biodegradation in simulated biological media. Furthermore, the hybrid nanoplatforms exhibited strong optical absorption between 250 and 420 nm, along with broad and intense photoluminescence (PL) in the near-infrared (NIR) region (680-900 nm), which is highly desirable for NIR-fluorescence diagnostic imaging. Notably, the hybrid nanoplatforms without DOX were non-cytotoxic to fibroblast and Caco-2 cells, while the DOX-loaded nanoplatforms exhibited selectivity and potent anticancer activity, inhibiting approximately 80% of Caco-2 colorectal cancer cells after 72 hours. These findings demonstrate that C2-600 and C4-600 are innovative, multifunctional and biodegradable nanoplatforms with powerful potential as drug carriers and fluorescence imaging agents, making them promising candidates for cancer theranostics.

Synergistic Enhancement of Carboplatin Efficacy through pH-Sensitive Nanoparticles Formulated Using Naturally Derived Boswellia Extract for Colorectal Cancer Therapy.

Carboplatin (Cp) is a potent chemotherapeutic agent, but its effectiveness is constrained by its associated side effects. Frankincense, an oleo-gum resin from the Boswellia sacra tree, has demonstrated cytotoxic activity against cancer cells. This study explored the synergistic potential of nanoparticles formulated from Boswellia sacra methanolic extract (BME), to enhance the therapeutic efficacy of Cp at reduced doses. Nanoparticles were prepared via the nanoprecipitation method, loaded with Cp, and coated with positively charged chitosan (CS) for enhanced cell interaction, yielding Cp@CS/BME NPs with an average size of 160.2 ± 4.6 nm and a zeta potential of 12.7 ± 1.5 mV. In vitro release studies revealed a pH-sensitive release profile, with higher release rates at pH 5.4 than at pH 7.4, highlighting the potential for targeted drug delivery in acidic tumor environments. In vitro studies on HT-29 and Caco-2 colorectal cancer cell lines demonstrated the nanoformulation's ability to significantly increase Cp uptake and cytotoxic activity. Apoptosis assays further confirmed increased induction of cell death with Cp@CS/BME NPs. Cell-cycle analysis revealed that treatment with Cp@CS/BME NPs led to a significant increase in the sub-G1 phase, indicative of enhanced apoptosis, and a marked decrease in the G1-phase population coupled with an increased G2/M-phase arrest in both cell lines. Further gene expression analysis demonstrated a substantial downregulation of the anti-apoptotic gene Bcl-2 and an upregulation of the pro-apoptotic genes Bax, PUMA, and BID following treatment with Cp@CS/BME NPs. Thus, this study presents a promising and innovative strategy for enhancing the therapeutic efficacy of chemotherapeutic agents using naturally derived ingredients while limiting the side effects.

Investigation of the effects of Protocatechuic acid on apoptosis, oxidant and antioxidant status in Caco-2 colorectal cancer cells

Aim: Protocatechuic acid (PCA) is one of the common phenolic acids found in many foods and plants and it has multiple biological activities. Although PCA has been investigated for its antioxidant, anti-inflammatory, and anticancer effects in various cell lines, its effects on molecules involved in the apoptotic pathway, especially in human colon cancer (Caco-2) cells, have not been fully elucidated. This study aimed to investigate the effects of PCA on possible oxidant, antioxidant, and apoptosis mechanisms in Caco-2 cells, depending on dose and time. Methods: In the experimental study, 4 groups were created: control (K), PCA (250-500-1000 µM). Total oxidant capacity (TOC), total antioxidant capacity (TAC), Oxidative stress index (OSI), Bax, Bad, Bcl-2, Bcl-xl, and Caspase 9 protein levels were determined by the ELISA method in the cell lysates obtained from the groups. Results: The results showed that PCA treatment had apoptotic effects on Caco-2 cells at 24 and 48 h. PCA also decreased OSI levels by increasing TAC levels and decreasing TOC levels in a dose-dependent manner. Conclusion: As a result, it was determined that PCA has an apoptotic effect on the Caco-2 cell line and can be useful in the prevention and/or treatment of colon cancer.

GOLPH3 inhibits erastin-induced ferroptosis in colorectal cancer cells.

Ferroptosis is a novel form of programmed cell death and is considered to be a druggable target for colorectal cancer (CRC) therapy. However, the role of ferroptosis in CRC and its underlying mechanism are not fully understood. In the present study we found that a protein enriched in the Golgi apparatus, Golgi phosphoprotein 3 (GOLPH3), was overexpressed in human CRC tissue and in several CRC cell lines. The expression of GOLPH3 was significantly correlated with the expression of ferroptosis-related genes in CRC. The overexpression of GOLPH3 in Erastin-induced Caco-2 CRC cells reduced ferroptotic phenotypes, whereas the knockdown of GOLPH3 potentiated ferroptosis in HT-29 CRC cells. GOLPH3 induced the expression of prohibitin-1 (PHB1) and prohibitin-2 (PHB2), which also inhibited ferroptosis in Erastin-treated CRC cells. Moreover, GOLPH3 interacted with PHB2 and nuclear factor erythroid 2-related factor 2 (NRF2) in Caco-2 cells. These observations indicate that GOLPH3 is a negative regulator of ferroptosis in CRC cells. GOLPH3 protects these cells from ferroptosis by inducing the expression of PHB1 and PHB2, and by interacting with PHB2 and NRF2.

Stress-induced Rab11a-exosomes induce amphiregulin-mediated cetuximab resistance in colorectal cancer.

Exosomes are secreted vesicles made intracellularly in the endosomal system. We have previously shown that exosomes are not only made in late endosomes, but also in recycling endosomes marked by the monomeric G-protein Rab11a. These vesicles, termed Rab11a-exosomes, are preferentially secreted under nutrient stress from several cancer cell types, including HCT116 colorectal cancer (CRC) cells. HCT116 Rab11a-exosomes have particularly potent signalling activities, some mediated by the epidermal growth factor receptor (EGFR) ligand, amphiregulin (AREG). Mutant activating forms of KRAS, a downstream target of EGFR, are often found in advanced CRC. When absent, monoclonal antibodies, such as cetuximab, which target the EGFR and block the effects of EGFR ligands, such as AREG, can be administered. Patients, however, inevitably develop resistance to cetuximab, either by acquiring KRAS mutations or via non-genetic microenvironmental changes. Here we show that nutrient stress in several CRC cell lines causes the release of AREG-carrying Rab11a-exosomes. We demonstrate that while soluble AREG has no effect, much lower levels of AREG bound to Rab11a-exosomes from cetuximab-resistant KRAS-mutant HCT116 cells, can suppress the effects of cetuximab on KRAS-wild type Caco-2 CRC cells. Using neutralising anti-AREG antibodies and an intracellular EGFR kinase inhibitor, we show that this effect is mediated via AREG activation of EGFR, and not transfer of activated KRAS. Therefore, presentation of AREG on Rab11a-exosomes affects its ability to compete with cetuximab. We propose that this Rab11a-exosome-mediated mechanism contributes to the establishment of resistance in cetuximab-sensitive cells and may explain why in cetuximab-resistant tumours only some cells carry mutant KRAS.

O209: Stress-induced extracellular vesicles promote EGFR-ERK dependent growth and cetuximab resistance in colorectal cancer

Abstract Introduction Extracellular vesicles (EVs) are nanoized vesicles, which deliver bioactive cargoes to target cells. Our lab has shown that metabolic stress leads to changes in the trafficking and also the cargo and functions of EVs secreted from colorectal cancer (CRC) cells: a so-called “EV switch”. Proteomic analysis revealed that switched EVs carry increased levels of the EGFR-ligand Amphiregulin (AREG). The aim of this work was to investigate the pro-tumorigenic properties of switched EVs in vitro and in vivo. Methods Size exclusion chromatography was used to isolate EVs from HCT116 and Caco-2 CRC cells grown under glutamine-replete and -depleted conditions, and their effect on recipient cell growth measured using the IncuCyte Live Cell Imager. Co-incubation assays with an AREG-neutralising antibody were undertaken to test the role of switched EVs. The in vivo role of switched EVs were investigated using a novel chick embryo model. In addition, we tested whether the growth inhibitory effects of cetuximab could be reversed by co-treatment with switched EVs. Results Switched EVs from HCT116 and Caco-2 cells contain increased levels of AREG and promote EGFR-ERK dependent growth in recipient cells in vitro and in vivo. These effects were inhibited by co-treatment with an AREG neutralising antibody. Caco-2 (KRAS-wild type), but not HCT116 (KRAS-mutant), cell growth was inhibited by cetuximab, which was partially reversed by co-treatment with switched EVs. AREG neutralisation reversed this EV-induced cetuximab rescue. Conclusion Switched EVs mediate CRC cell growth and cetuximab resistance, and could serve as novel biomarkers to predict treatment response.

Involucrasin B Inhibits the Proliferation of Caco-2 Cells by Regulating the TGFβ/SMAD2-3-4 Pathway.

(1) Background: Colorectal cancer (CRC) is the third most common malignant tumor worldwide and the second most common cause of cancer death. However, effective anti-CRC drugs are still lacking in clinical settings. This article investigated the anti-proliferative effect of involucrasin B on CRC Caco-2 cells. (2) Methods: This study employed a sulforhodamine B (SRB) method, colony formation experiments, flow cytometry, FastFUCCI assay, dual luciferase assay, and Western blot analysis for the investigation. (3) Results: The SRB method and colony formation experiments showed that involucrasin B exhibited an inhibitory effect on the Caco-2 cells cultured in vitro. Subsequently, the flow cytometry, FastFUCCI assay, and Western blotting results showed that involucrasin B induced cell cycle arrest in the G1 phase dose-dependently. Involucrasin B significantly enhanced the TGFβ RII protein level and SMAD3 phosphorylation, thus inhibiting the expression of CDK4 and cyclin D1 and causing G1 cell cycle arrest. (4) Conclusion: This study shows that involucrasin B exerts its anti-proliferative effect by regulating the TGFβ/SMAD2-3-4 pathway to cause G1 cycle arrest in Caco-2 cells.

The combined anticancer of peanut skin procyanidins and resveratrol to CACO-2 colorectal cancer cells.

Colorectal cancer is one of the leading causes of cancer deaths worldwide. Currently, chemotherapy is the primary way for colorectal cancer, but with severe side effects. Therefore, it is urgent to find safer and more effective adjuvant treatment methods. At present, natural active substances are promising alternatives, as numerous studies have demonstrated possible synergistic anticancer effects in plant-active polyphenols. In the present study, the combined effect of procyanidins (PC) (from peanut skin) and resveratrol (RES) (from peanut buds) on the synergistic anticancer potential was investigated. CACO-2 and HCT-8 cells were served as colorectal cancer models, and HEPG-2 and HUH-7 cells were served as liver cancer models to observe the effects of PC and RES alone or in combination on the growth and proliferation of these four types of cancer cells. The results revealed that both PC and RES could inhibit the cells' proliferation in a manner with concentration-dependent, but they exerted synergistic anticancer effects only on CACO-2 cells. PC and RES could synergistically inhibit CACO-2 cell clone formation, inducing apoptosis of CACO-2 cells and blocking their cell cycle in G0/G1 phase. Additionally, as observed by the results of Western blot assay, the combined effect of PC and RES also inhibited the phosphorylation of Thr308, Ser473, and ERK and promoted the phosphorylation of IKBα and NF-κB in CACO-2 cells. These findings collectively indicate that PC combined with RES might exert synergistic anticancer effects by regulating AKT, ERK, and NF-κB signaling pathways.

In vitro study on antitumor activity of aurantiamide acetate extracted from Polygonum capitatum

Aurantiamide acetate is a dipeptide derivative with antibacterial, antiviral, anti-inflammatory and analgesic activities. However, its antitumor activity has not been documented. This study aimed to prepare aurantiamide acetate from Polygonum capitatum and investigate its antitumor activity in vitro. The petroleum ether extract fraction of 80% ethanol extract from P. capitatum was separated by silica gel column chromatography. Aurantiamide acetate was obtained and identified by physicochemical properties, MS and NMR spectral data. The inhibitory effect of different doses of this compound on the proliferation of human umbilical vein endothelial cells (HUVECs), human gastric cancer BGC-823 cells, lung cancer A549 cells and colorectal cancer Caco-2 cells was detected by CCK-8 method. Morphological changes of BGC-823 cells were observed under the inverted microscope. The effect of aurantiamide acetate on BGC-823 apoptosis and cycle was detected by flow cytometry. The expression of Bax and caspase-3 in BGC-823 cells was detected by Western blotting. Aurantiamide acetate inhibited BGC-823, A549 and Caco-2 cell proliferation at the concentrations from 25 μmol/L to 100 μmol/L, but had no inhibitory effect on HUVECs at the concentrations from 12.5 μmol/L to 100 μmol/L. The inhibitory effect of Aurantiamide acetate was most pronounced on BGC-823 cell proliferation at IC50 of 56.73 μmol/L, most probably by increasing the protein expression of caspase-3 and Bax in BGC-823 cells, and arresting cell cycle in G2/M phase. This is the first time that we isolated aurantiamide acetate from P. capitatum with a purity of 98.21%, and found that Aurantiamide acetate could in inhibit the proliferation of various cancer cell types in vitro. This finding may provide a new resource for developing anti-tumor drugs in future.

Anticancer properties of red beetroot hydro-alcoholic extract and its main constituent; betanin on colorectal cancer cell lines

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Red beetroot (Beta vulgaris) contains Betanin as its major betacyanin, possessing wide proapoptotic effects. This study aimed to investigate the anticancer and pro-papoptotic effects of beetroot hydro-alcoholic extract (BHE) and betanin, on colorectal cancer cell lines. BHE and betanin were used to treat Caco-2 and HT-29 colorectal cancer cells. MTT assay, DAPI staining, and FACS-flow cytometry tests were used to determine the half-maximal inhibitory concentration (IC50) and apoptosis-inducing evaluations. Intended genes were assessed by real-time polymerase chain reaction (RT-PCR). The IC50 for HT-29 and Caco-2 cell lines were 92 μg/mL, 107 μg/mL for BHE, and 64 μg/mL, 90 μg/mL for betanin at 48 h, respectively. BHE and betanin significantly inhibited the growth of both cancer cell lines time and dose-dependently. DAPI staining and flow cytometry results revealed significant apoptosis symptoms in treated cancerous cell lines. The expression level of proapoptotic genes (BAD, Caspase-3, Caspase-8, Caspase-9, and Fas-R) in treated HT-29 and Caco-2 cells was higher than in untreated and normal cells. In contrast, the anti-apoptotic gene (Bcl-2) was significantly downregulated. BHE and betanin effectively inhibited cancer cell proliferation and induced apoptosis via the modification of effective genes.

Colorectal cancer-secreted exosomal circ_001422 plays a role in regulating KDR expression and activating mTOR signaling in endothelial cells by targeting miR-195-5p.

As non-coding RNAs, exosomal circular RNAs (circRNAs) regulate colorectal cancer (CRC) progression, although the functional mechanisms by which such molecules affect the tumor microenvironment are still elusive. Herein, we aimed to explore the potential clinical significance of a signature of five serum-derived circRNAs in CRC and investigated the mechanisms underlying endothelial cell angiogenesis mediated by CRC-secreted exosomal circ_001422. The expression of a signature of five serum-derived circRNAs (circ_0004771, circ_0101802, circ_0082333, circ_0072309, and circ_001422) were measured by RT-qPCR, and their associations with tumor staging and lymph node metastasis were further evaluated in CRC patients. In silico analysis was used to show the relationship between circ_001422, miR-195-5p, and KDR, validated by dual-luciferase reporter and Western blotting assays. CRC cell-derived exosomes were isolated and characterized by scanning electron microscopy and Western blotting. Endothelial cell uptake of PKH26-labeled exosomes was demonstrated using a spectral confocal microscope. In vitro genetic strategies were used to exogenously alter the expression level of circ_001422 and miR-195-5p expression. Cell proliferation assay, transwell migration assay, and capillary tube formation assay were conducted to explore the role of CRC-secreted exosomal circ_001422 in endothelial cell function in vitro. The expression levels of serum-derived circ_0004771, circ_0101802, circ_0082333, and circ_001422 were significantly higher in CRC and were positively correlated with the lymph node metastasis status. However, circ_0072309 showed a significant down-regulation in CRC than in healthy individuals. Furthermore, a higher expression level of circ_001422 in both cellular and exosomal fractions was found in HCT-116 CRC cells. We found that HCT-116 exosomes considerably enhanced proliferation and migration of endothelial cells through shuttling of circ_001422. We also observed that exosomes derived from HCT-116 cell, but not non-aggressive Caco-2 CRC cells, increased in vitro tubulogenesis of endothelial cells. Importantly, knockdown of circ_001422 impaired the capability of endothelial cells to form the capillary-like tube structures. CRC-secreted circ_001422 acted as an endogenous miR-195-5p sponge to inhibit miR-195-5p activity, which led to increased KDR expression and mTOR signaling activation in endothelial cells. Importantly, ectopic expression of miR-195-5p mimicked the effect of circ_001422 silencing on KDR/mTOR signaling in endothelial cells. This study attributed a biomarker role for circ_001422 in CRC diagnosis and proposed a novel mechanism whereby circ_001422 up-regulates KDR through sponging miR-195-5p. These interactions may give rise to the activation of mTOR signaling and may be a possible clarification for the pro-angiogenesis effects of CRC-secreted exosomal circ_001422 on endothelial cells.

Daphnanes diterpenes from the latex of Hura crepitans L. and their PKCζ-dependent anti-proliferative activity on colorectal cancer cells

Hura crepitans L. (Euphorbiaceae) is a thorn-covered tree widespread in South America, Africa and Asia which produces an irritating milky latex containing numerous secondary metabolites, notably daphnane-type diterpenes known as Protein Kinase C activators. Fractionation of a dichloromethane extract of the latex led to the isolation of five new daphnane diterpenes (1–5), along with two known analogs (6–7) including huratoxin. Huratoxin (6) and 4′,5′-epoxyhuratoxin (4) were found to exhibit significant and selective cell growth inhibition against colorectal cancer cell line Caco-2 and primary colorectal cancer cells cultured as colonoids. The underlying mechanism of 4 and 6 was further investigated revealing the involvement of PKCζ in the cytostatic activity.

The Oncosuppressive Properties of KCTD1: Its Role in Cell Growth and Mobility.

The KCTD protein family is traditionally regarded as proteins that play key roles in neurological physiopathology. However, new studies are increasingly demonstrating their involvement in many other biological processes, including cancers. This is particularly evident for KCTD proteins not involved in protein ubiquitination and degradation, such as KCTD1. We explored the role of KCTD1 in colorectal cancer by knocking down this protein in the human colon adenocarcinoma cell line, SW480. We re-assessed its ability to downregulate β-catenin, a central actor in the WNT/β-catenin signalling pathway. Interestingly, opposite effects are observed when the protein is upregulated in CACO2 colorectal cancer cells. Moreover, interrogation of the TCGA database indicates that KCTD1 downregulation is associated with β-catenin overexpression in colorectal cancer patients. Indeed, knocking down KCTD1 in SW480 cells led to a significant increase in their motility and stemness, two important tumorigenesis traits, suggesting an oncosuppressor role for KCTD1. It is worth noting that similar effects are induced on colorectal cancer cells by the misregulation of KCTD12, a protein that is distantly related to KCTD1. The presented results further expand the spectrum of KCTD1 involvement in apparently unrelated physiopathological processes. The similar effects produced on colorectal cancer cell lines by KCTD1 and KCTD12 suggest novel, previously unreported analogous activities among members of the KCTD protein family.

Preparation and Characterization of Rutin-Encapsulated Polymeric Micelles and Studies of Synergism with Bioactive Benzoic Acids and Triazolofluoroquinolones as Anticancer Nanomedicines.

The study aimed to examine rutin micelles of advanced superlative dual cytotoxicity-antiinflammtion bioefficacies in substantially novel submicro-nanoaffinities vs. both the raw rutin and reference proapoptotic cisplatin. Antiproliferative capabilities of rutin, benzoic acid (BA) and triazolofluoroqunolone (TFQ) derivatives were reported; hence chemosensitizing effects of rutin or its polymeric micelles (of improved solubility and bioavailability via direct dissolution using the amphiphilic copolymer Pluronic P123) in co-incubations with 5 BAs or 3 TFQ derivatives in a panel of 6 cancer cell lines were verified. Rutin loading in micelles was achieved with a loading efficiency of 59.5 ± 2.9%. The particle size of the micelles was found to be 18 ± 2 nm. Though Rutin loaded nanomicelles were of minimal DPPH radical scavenging activity; they had nitrogen oxide (NO) radical scavenging activity in lipopolysaccharide-induced RAW264.7 macrophages with equipotency to indomethacin (IC50 values (µM) 73.03 vs. 60.88; p=0.057). Remarkably nano-micelle formulation of rutin was proved of significantly more potent antineoplastic bioactivity with submicro-nanomolar affinities in the 6 cancer cell lines vs. both free rutin's and cisplatin's (except A549 lung cancer cell line). Rrutin nanomicelles chemo-sensitized all selected 8 cotreatments with BA derivatives and TFQs and, thus reducing the dose used against breast cancer MCF7 cells to submicro-nanomolar affinities of greater potencies than cisplatin's. Except for Triazolo-4-anisidine cipro butyl acid in PANC1, 2-Amino-3,5-Di iodo BA in A375 and 4-Nitrophenol in A549 incubations; rutin loaded nanomicelles chemosensitized 7/8 cotreating selected benzoic acid (BAs) derivatives and TFQs and chemosensitized pancreatic PANC1, skin A375 and lung A549 cancer cell lines, thus reducing the dose to submicro-nanomolar affinities of greater potencies than cisplatin's. Rutin loaded nanomicelles chemosensitize 6/8 cotreating selected benzoic acid (BA) derivatives and TFQs (except for 2-Amino-5-Bromo Benzoic Acid and Triazolo-4-anisidine cipro butyl acid), thus reducing the dose used against resistant CACO2 colorectal cancer cells.

Phytochemical Analysis and Anticancer Properties of Drimia maritima Bulb Extracts on Colorectal Cancer Cells.

Cancer is a worldwide health problem and is the second leading cause of death after heart disease. Due to the high cost and severe side effects associated with chemotherapy treatments, natural products with anticancer therapeutic potential may play a promising role in anticancer therapy. The purpose of this study was to investigate the cytotoxic and apoptotic characteristics of the aqueous Drimia maritima bulb extract on Caco-2 and COLO-205 colorectal cancer cells. In order to reach such a purpose, the chemical composition was examined using the GC-MS method, and the selective antiproliferative effect was determined in colon cancer cell lines in normal gingival fibroblasts. The intracellular ROS, mitochondrial membrane potential, and gene expression changes in selected genes (CASP8, TNF-α, and IL-6 genes) were assessed to determine the molecular mechanism of the antitumor effect of the extract. GC-MS results revealed the presence of fifty-seven compounds, and Proscillaridin A was the predominant secondary metabolite in the extract. The IC50 of D. maritima bulb extract on Caco-2, COLO-205, and the normal human gingival fibroblasts were obtained at 0.9 µg/mL, 2.3 µg/mL, and 13.1 µg/mL, respectively. The apoptotic effect assay indicated that the bulb extract induced apoptosis in both colon cancer cell lines. D. maritima bulb extract was only able to induce statistically significant ROS levels in COLO-205 cells in a dose-dependent manner. The mitochondrial membrane potential (MMP) revealed a significant decrease in the MMP of Caco-2 and COLO-205 to various concentrations of the bulb extract. At the molecular level, RT-qPCR was used to assess gene expression of CASP8, TNF-α, and IL-6 genes in Caco-2 and COLO-205 cancer cells. The results showed that the expression of pro-inflammatory genes TNF-α and IL-6 were upregulated. The apoptotic initiator gene CASP8 was also upregulated in the Caco-2 cell line and did not reach significance in COLO-205 cells. These results lead to the conclusion that D. maritima extract induced cell death in both cell lines and may have the potential to be used in CRC therapy in the future.

Chemopreventive Effects of Onosma mutabilis against Azoxymethane-Induced Colon Cancer in Rats via Amendment of Bax/Bcl-2 and NF-κB Signaling Pathways.

Onosma species (Boraginaceae) are well known as medicinal plants due to their wide range of pharmaceutical potential. The present study aims to investigate the anticancer (in vitro) and chemo-protective (in vivo) efficacies of Onosma mutabilis extract (OME) in the azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rats. The in vitro antiproliferative effects of OME were determined on two human tumor cell lines (Caco-2 and HT-29) via MTT assay. The in vivo chemoprotective effects of OME were investigated by performing various biochemical analyses in serum and tissue homogenates of albino rats, along with determining oxidative stress biomarkers. Inflammatory biomarkers of colon, colonic gross morphology (by methylene blue), ACF formation, and colonic histopathology (H & E stain) were determined. The immunohistochemistry of colonic tissues was also assessed by Bax and Bcl-2 protein expression. The results showed that the antitumor activity of OME against Caco-2 and HT-29 colorectal cancer cells ranged between 22.28-36.55 µg/mL. OME supplementation caused a significant drop in the ACF values and improved the immunohistochemistry of the rats shown by up-regulation of Bax and down-regulation of Bcl-2 protein expressions. These outcomes reveal that O. mutabilis may have chemoprotective efficiency against AOM-induced colon cancer represented by the attenuation of ACF formation possibly through inhibition of free radicals, inflammation, and stimulation of the colon antioxidant armory (SOD, CAT, and GPx) and positive regulation of the Nrf2-Keap1 pathway.

Plantaricin BM-1 decreases viability of SW480 human colorectal cancer cells by inducing caspase-dependent apoptosis.

Plantaricin BM-1 is a class IIa bacteriocin produced by Lactobacillus plantarum BM-1 that has significant antimicrobial activity against food-borne bacteria. In this study, a cell proliferation assay and scanning electron microscopy were used to detect changes in the viability of SW480, Caco-2, and HCT-116 colorectal cancer cells treated with plantaricin BM-1. We found that plantaricin BM-1 significantly reduced the viability of all colorectal cancer cell lines tested, especially that of the SW480 cells. Scanning electron microscopy showed that plantaricin BM-1 treatment reduced the number of microvilli and slightly collapsed the morphology of SW480 cells. Fluorescence microscopy and flow cytometry demonstrated that plantaricin BM-1 induced apoptosis of SW480 cells in a concentration-dependent manner. Western blotting further showed that plantaricin BM-1-induced apoptosis of SW480 cells was mediated by the caspase pathway. Finally, transcriptomic analysis showed that 69 genes were differentially expressed after plantaricin BM-1 treatment (p < 0.05), of which 65 were downregulated and four were upregulated. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that expression levels of genes involved in the TNF, NF-κB, and MAPK signaling pathways, as well as functional categories such as microRNAs in cancer and transcriptional misregulation in cancer, were affected in SW480 cells following the treatment with plantaricin BM-1. In conclusion, plantaricin BM-1 induced death in SW480 cells via the caspase-dependent apoptosis pathway. Our study provides important information for further development of plantaricin BM-1 for potential applications in anti-colorectal cancer.

Glutamine induces remodeling of tight junctions in Caco-2 colorectal cancer cell

Malignant cells often exhibit significant metabolic alterations, including the utilization of different nutrients to meet energetic and biosynthetic demands. Recent studies have shown that glutamine can support primary colorectal tumor growth and also serve as an alternate energy source during distant metastasis under glucose-limited conditions. However, the overall effects of glutamine on cancer cell physiology are not completely understood. In this study, we investigated how glutamine impacts epithelial integrity in colorectal cancer cells under glucose deprivation. Human colorectal cancer (Caco-2) cells were grown to confluency in transwells and cultured in glucose/pyruvate-free DMEM with various glutamine concentrations (0–50 mM). Cell viability was assessed, and monolayer integrity was examined in terms of transepithelial resistance (TER) and paracellular permeability. Tight junction (TJ) component proteins were examined by immunofluorescence staining and Western blotting. A dose-dependent decrease in TER was observed in Caco-2 cells, but paracellular permeability was not affected after 24 h incubation with glutamine. At the same time, the TJ proteins, zonula occludens (ZO)-1 and Claudin-1, showed lateral undulations and punctate staining patterns accompanied by enlargement of cellular and nuclear sizes. Furthermore, decreased protein levels of ZO-1, but not claudin-1, were found in detergent-insoluble cellular fractions. Notably, the decreased TER and alterations in TJ structure were not associated with cell viability changes. Moreover, the addition of glutamate, which is produced by the first step of glutamine catabolism, had no impact on TER. Our results suggested that the enteral glutamine may play an important role in the regulation of TJ dynamics in colorectal cancer cells.

Design, synthesis and molecular docking of novel substituted azepines as inhibitors of PI3K/Akt/TSC2/mTOR signaling pathway in colorectal carcinoma

A series of novel substituted azepines (2–7) was synthesized using both traditional and ultrasonic techniques. The efficiency of the reaction rate and yield was improved by sonication technique. We identified the newly synthesized compounds based on their melting points, elemental analyses, and spectral data. Human cancers are regulated mainly by the phosphatidylinositol 3-kinase/protein kinases B (PI3K/Akt) pathway, and its abnormal activation is linked to carcinogenesis, and angiogenesis. Using in-silico studies, we evaluated the ability of all the novel substituted diazepines and oxazepines to prevent cancer growth and metastasis by targeting the PI3K/Akt signaling pathway. Based on our findings, compounds 4a and 7a were chosen for in-vitro testing as they ranked via molecular docking the highest binding energies of −10.9, −10.3, −10.6, and −10.4 kcal/mol respectively. Compounds 4a and 7a displayed significant cytotoxicity on Caco-2 colorectal cancer cells with IC50 values of 8.445 ± 2.26 and 33.04 ± 2.06 μM, respectively. Additionally, they considerably suppressed the PI3K/Akt proteins and generated reactive oxygen species (ROS), which increased p53 and Bax, decreased Bcl-2 levels, and arrested the cell cycle at sub-G0/G1 phase. We also observed a remarkable overexpression of the Tuberous Sclerosis Complex 2 (TSC2) gene, an inhibitor of the mammalian target of rapamycin (mTOR). These results showed that compounds 4a and 7a obeyed Lipinski's rule of five and might be potential cancer treatment scaffolds by preventing metastasis and proliferation via blocking the PI3K/Akt/TSC2/m-TOR signaling pathway. This supports our hypothesis that diazepine 4a and oxazepine 7a are promising drug candidates for colorectal cancer.