Inhibits Colon Cancer Cell Growth Research Articles

Synthetic free fatty acid receptor (FFAR) 2 agonist 4-CMTB and FFAR4 agonist GSK13764 inhibit colon cancer cell growth and migration and regulate FFARs expression in in vitro and in vivo models of colorectal cancer.

Free fatty acid receptors (FFARs) are G protein-coupled receptors that divide into 4 subtypes; FFAR2 and FFAR3 are activated by short-chain fatty acids, while FFAR1 and FFAR4 - by long-chain fatty acids. Recent studies show the potential involvement of FFARs in the pathophysiology of colorectal cancer (CRC). A decrease in FFAR2 and FFAR4 gene expression is observed in patients with CRC. The aim of our study was to evaluate the anti-cancer effect of FFAR2 and FFAR4 stimulation by selective synthetic agonists in in vitro and in vivo models of CRC. FFAR2 agonist, 4-CMTB, and FFAR4 agonist, GSK137647 were used. Cell viability (CCD 841 CoN and SW-480) was determined after 48h incubation with tested compounds using MTT assay. Real-time qPCR and Western Blot were used to identify changes in FFARs expression. Migration and invasion were characterized by commercially available tests. Colitis-associated CRC (CACRC) mouse model was induced by azoxymethane and dextran sodium sulfate. 4-CMTB and GSK137647 significantly reduced cancer cell growth as well as migration and invasion capacities. Both synthetic compounds increased FFAR2 and FFAR4 expression in SW-480 cells. Neither 4-CMTB nor GSK137647 influenced the course of AOM/DSS-induced CACRC in mice, however, 4-CMTB elevated FFAR2 protein expression in mouse tissues. We presented that stimulation of FFAR2 and FFAR4 may inhibit CRC cell viability and migration and that the FFAR2 and FFAR4 expression decreased in CRC can be restored by treatment with respective agonists, indicating new promising pharmacological targets in CRC treatment.

Siah2 inhibitor and the metabolic antagonist Oxamate retard colon cancer progression and downregulate PD1 expression.

Solid tumors such as colon cancer are characterized by rapid and sustained cell proliferation, which ultimately results in hypoxia, induction of hypoxia-inducible factor-1α (HIF-1α), and activation of glycolysis to promote tumor survival and immune evasion. We hypothesized that a combinatorial approach of menadione (MEN) as an indirect HIF-1α inhibitor and sodium oxamate (OX) as a glycolysis inhibitor may be a promising treatment strategy for colon cancer. We investigated the potential efficacy of this combination for promoting an antitumor immune response and suppressing tumor growth in a rat model of colon cancer. Colon cancer was induced by once-weekly subcutaneous injection of 20 mg/kg dimethylhydrazine (DMH) for 16 weeks. Control rats received the vehicle and then no further treatment (negative control) or MEN plus OX for 4 weeks (drug control). Dimethylhydrazine-treated rats were then randomly allocated to four groups: DMH alone group and other groups treated with MEN, OX, and a combination of (MEN and OX) for 4 weeks. Serum samples were assayed for the tumor marker carbohydrate antigen (CA19.9), while expression levels of HIF-1α, caspase-3, PHD3, LDH, and PD1 were evaluated in colon tissue samples by immunoassay and qRT-PCR. Additionally, Ki-67 and Siah2 expression levels were examined by immunohistochemistry. The combination of MEN plus OX demonstrated a greater inhibitory effect on the expression levels of HIF-1α, Siah2, LDH, Ki-67, and PD1, and greater enhancement of caspase-3 and PHD3 expression in colon cancer tissues than either drug alone. Simultaneous targeting of hypoxia and glycolysis pathways by a combination of MEN and OX could be a promising therapy for inhibiting colon cancer cell growth and promoting antitumor immunity [1].

Knockdown of B3GNT3 inhibits colon cancer cell growth and migration

Knockdown of B3GNT3 inhibits colon cancer cell growth and migration

Quercetin-induced pyroptosis in colon cancer through NEK7-mediated NLRP3 inflammasome-GSDMD signaling pathway activation.

Pyroptosis, a gasdermin-mediated lytic cell death, is a new hotspot topic in cancer research, and induction of tumor pyroptosis has emerged as a new target in cancer management. Quercetin (Que), a natural substance, demonstrates promising anticancer action. However, further information is required to fully comprehend the function and mechanism of Que in pyroptosis in colon cancer. This study revealed the underlying mechanism of Que-induced pyroptosis in colon cancer in vitro and in vivo. Que inhibited colon cancer cell growth through gasdermin D (GSDMD)-mediated pyroptosis. Depletion of GSDMD, rather than gasdermin E (GSDME), reversed the cytotoxic effects of Que on colon cancer cells. Que treatment upregulated NIMA-related kinase 7 (NEK7) protein expression, thus facilitating the assembly of the NLRP3 inflammasome and cleavage of GSDMD. NEK7 silencing resulted in colon cancer cell growth in vitro and in vivo. Mechanistically, NEK7 depression restrained the activation of the NLRP3 inflammasome-GSDMD pathway, thus attenuating pyroptosis triggered by Que in colon cancer cells. Furthermore, lower NEK7 and NLRP3 expression levels indicated colon cancer progression. Our results unveiled a novel pattern of anti-colon cancer activity of Que, and activation of NEK7-mediated pyroptosis is potentially a promising therapeutic target for colon cancer, which provides novel experimental proof for the clinical application of Que.

Ginger Root Bioactive Compounds Specifically Inhibits Growth of Colon Cancer Cells in Culture.

Colon cancer is affluent among many people, and having cancer greatly impacts the lives of many. Ginger is a common food, particularly in Asian cuisine. However, the health benefits of ginger as a whole food and 6-gingerol, its bioactive compound in prevention of colon cancer have not been fully addressed. This experiment investigated effects of ginger juice and 6-gingerol on colon cancer cell growth and death. Fresh ginger roots were homogenized for juice preparation. Total phenolic contents of ginger juice were measured using Folin-C assay. Colon cancer SW480 cells and normal colon epithelial cells CCD-18Co were treated with ginger juice and/or 6-gingerol. Cell metabolic activity was assessed by MTT assay. Cell apoptosis and cell cycle arrest were accessed by immunoblotting. Data were analyzed by 2-way ANOVA with a Tukey post-hoc test and statistical significance was set at P < .05. The results showed that ginger juice selectively inhibited SW480 cell growth at 25 µL/mL for 40 hours. High doses of ginger juice (at 50 and 100 µL/mL for 40 hours) inhibited the growth of both cell types. This was independent of caspase-3 activation. Six-gingerol specifically inhibited SW480 cell growth starting at 0.5 µmoL/L (P < .01). More than 1 µmoL/L 6-gingerol did not give more power to inhibit SW480 cell growth. The results also showed that CCD-18Co cell growth rates were not changed after 6-gingerol treatments (up to 10 µmoL/L, P > .1). Immunoblotting results revealed that the elevation of Myt1 levels and decreases in CDK1, p21 Wafl/Cip1 and pSer642-Wee1 only occurred in SW480 but not CCD-18Co cells when treated with 1 and/or 2.5 µmoL/L 6-gingerol for 40 hours. 6-gingerol can specifically inhibit SW480 cancer cells without killing normal CCd-18Co cells, through cell cycle arrest. Ginger juice can selectively inhibit colon cancer cell growth in a narrow window at ~25 µL/mL.

LncRNA MYLK antisense RNA 1 activates cell division cycle 42/Neutal Wiskott-Aldrich syndrome protein pathway via microRNA-101-5p to accelerate epithelial-to-mesenchymal transition of colon cancer cells.

Long noncoding RNA MYLK antisense RNA 1 (MYLK-AS1) is the crux in multiple diseases. Therefore, the purpose of this study was to investigate the possible mechanism of MYLK-AS1. A total of 62 colon cancer (CC) specimens and paired adjacent normal tissues were collected, and the expression of MYLK-AS1, microRNA (miR)-101-5p/cell division cycle 42 (CDC42) was detected. CC cell lines were transfected with MYLK-AS1, miR-101-5p, CDC42-related plasmids, and the biological functions and markers of epithelial-mesenchymal transition (EMT) were analyzed. The binding relationship between MYLK-AS1, miR-101-5p, and CDC42 was evaluated. In CC tissues and cell lines, MYLK-AS1 and CDC42 were highly expressed, and miR-101-5p was lowly expressed. Inhibition of MYLK-AS1 or upregulation of miR-101-5p can inhibit CC cell growth and EMT. miR-101-5p inhibited CDC42/N-wasp axis activation in CC cells by targeting CDC42. Knockdown of CDC42 or upregulation of miR-101-5p partially reversed the effects caused by upregulation of MYLK-AS1. MYLK-AS1, which is significantly upregulated in CC, may be a molecular sponge for miR-101-5p, and MYLK-AS1 promotes the activation of the CDC42/N-wasp axis in CC cells by targeting CDC42 through miR-101-5p, which in turn promotes tumor development. MYLK-AS1 may be a potential biomarker and target for CC therapy.

Mechanism of Bazhen decoction in the treatment of colorectal cancer based on network pharmacology, molecular docking, and experimental validation.

Bazhen Decoction (BZD) is a common adjuvant therapy drug for colorectal cancer (CRC), although its anti-tumor mechanism is unknown. This study aims to explore the core components, key targets, and potential mechanisms of BZD treatment for CRC. The Traditional Chinese Medicine Systems Pharmacology (TCMSP) was employed to acquire the BZD's active ingredient and targets. Meanwhile, the Drugbank, Therapeutic Target Database (TTD), DisGeNET, and GeneCards databases were used to retrieve pertinent targets for CRC. The Venn plot was used to obtain intersection targets. Cytoscape software was used to construct an "herb-ingredient-target" network and identify core targets. GO and KEGG pathway enrichment analyses were conducted using R language software. Molecular docking of key ingredients and core targets of drugs was accomplished using PyMol and Autodock Vina software. Cell and animal research confirmed Bazhen Decoction efficacy and mechanism in treating colorectal cancer. BZD comprises 173 effective active ingredients. Using four databases, 761 targets related to CRC were identified. The intersection of BZD and CRC yielded 98 targets, which were utilized to construct the "herb-ingredient-target" network. The four key effector components with the most targets were quercetin, kaempferol, licochalcone A, and naringenin. Protein-protein interaction (PPI) analysis revealed that the core targets of BZD in treating CRC were AKT1, MYC, CASP3, ESR1, EGFR, HIF-1A, VEGFR, JUN, INS, and STAT3. The findings from molecular docking suggest that the core ingredient exhibits favorable binding potential with the core target. Furthermore, the GO and KEGG enrichment analysis demonstrates that BZD can modulate multiple signaling pathways related to CRC, like the T cell receptor, PI3K-Akt, apoptosis, P53, and VEGF signaling pathway. In vitro, studies have shown that BZD dose-dependently inhibits colon cancer cell growth and invasion and promotes apoptosis. Animal experiments have shown that BZD treatment can reverse abnormal expression of PI3K, AKT, MYC, EGFR, HIF-1A, VEGFR, JUN, STAT3, CASP3, and TP53 genes. BZD also increases the ratio of CD4+ T cells to CD8+ T cells in the spleen and tumor tissues, boosting IFN-γ expression, essential for anti-tumor immunity. Furthermore, BZD has the potential to downregulate the PD-1 expression on T cell surfaces, indicating its ability to effectively restore T cell function by inhibiting immune checkpoints. The results of HE staining suggest that BZD exhibits favorable safety profiles. BZD treats CRC through multiple components, targets, and metabolic pathways. BZD can reverse the abnormal expression of genes such as PI3K, AKT, MYC, EGFR, HIF-1A, VEGFR, JUN, STAT3, CASP3, and TP53, and suppresses the progression of colorectal cancer by regulating signaling pathways such as PI3K-AKT, P53, and VEGF. Furthermore, BZD can increase the number of T cells and promote T cell activation in tumor-bearing mice, enhancing the immune function against colorectal cancer. Among them, quercetin, kaempferol, licochalcone A, naringenin, and formaronetin are more highly predictive components related to the T cell activation in colorectal cancer mice. This study is of great significance for the development of novel anti-cancer drugs. It highlights the importance of network pharmacology-based approaches in studying complex traditional Chinese medicine formulations.

β-Sitosterol blocks the LEF-1-mediated Wnt/β-catenin pathway to inhibit proliferation of human colon cancer cells

ObjectivesThis study aimed to investigate the LEF-1-mediated Wnt/β-catenin pathway for its biological functions and prognostic value in colon cancer (CC). Furthermore, the potential molecular mechanism of β-sitosterol in CC was investigated in vitro. MethodsClinical information and gene expression profiles from CC patients were obtained based on Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In addition, we applied R software “Limma” package for the differential analysis of LEF-1 between cancer and para-carcinoma tissue samples. Kaplan–Meier (KM) survival analysis was adopted for analyzing whether LEF-1 was of prognostic significance. Moreover, gene set enrichment analysis (GSEA) was adopted for pathway enrichment analysis and visualization. In addition, CCK8, plate cloning, scratch and high-content screening (HCS) imaging assays were performed to examine the therapeutic efficacy of β-sitosterol in human CC HCT116 cells. siRNA technology was employed to knock down LEF1 expression in HCT116 cells. qRT-PCR and Western-blot (WB) analysis were carried out to analyze the HCT-116 mRNA and protein expression levels, respectively. ResultsLEF-1 was up-regulated within CC and acted as an oncogenic gene. LEF-1 up-regulation predicted the dismal prognostic outcome and activated the Wnt/β-catenin pathway. β-sitosterol effectively suppressed HCT116 cells proliferation and invasion. For the mechanism underlying β-sitosterol, β-sitosterol was found to significantly down-regulate LEF-1 gene and protein expression and disrupt Wnt/β-catenin pathway transmission in HCT116 cells. After suppressing LEF-1 expression, its downstream targets including C-myc, Survivin and CCND1 were also down-regulated. ConclusionAccording to our results, LEF-1 down-regulation can effectively block Wnt/β-catenin pathway, inhibit CC cell growth and migration. Collectively, β-sitosterol can be used to treat CC, which can provide anti-tumor activity by targeting LEF-1.

DGG-300273, a novel WNT/β-catenin inhibitor, induces apoptotic cell death by activating ROS-BIM signaling in a Wnt-dependent manner in colon cancer cells.

Dysregulated Wnt signaling is associated with malignant oncogenic transformation, especially in colon cancer. Recently, numerous drugs have been developed based on tumorigenesis biomarkers, thus having high potential as drug targets. Likewise, WNT/β-catenin pathway members are attractive therapeutic targets for colon cancer and are currently in various stages of development. However, although inhibitors of proteins regulating the WNT/β-catenin signaling pathway have been extensively studied, they have yet to be clinically approved, and the underlying molecular mechanism(s) of their anticancer effects remain poorly understood. Herein, we show that a novel WNT/β-catenin inhibitor, DGG-300273, inhibits colon cancer cell growth in a Wnt-dependent manner due to upregulation of the BCL2-family protein Bim and caspase-dependent apoptotic cell death. Additionally, DGG-300273-mediated cell death occurs by increased reactive oxygen species (ROS), as shown by abrogation of apoptotic cell death and ROS production following pretreatment with the antioxidant N-acetylcysteine. These results suggest that DGG-300273 represents a promising investigational drug for the treatment of Wnt-associated cancer, thus warranting further characterization and study.

Magnetomechanical Stress-Induced Colon Cancer Cell Growth Inhibition

The application of magnetomechanical stress in cells using internalized magnetic nanoparticles (MNPs) actuated by low-frequency magnetic fields has been attracting considerable interest in the field of cancer research. Recent developments prove that magnetomechanical stress can inhibit cancer cells’ growth. However, the MNPs’ type and the magnetic field’s characteristics are crucial parameters. Their variability allows multiple combinations, which induce specific biological effects. We previously reported the antiproliferative effects induced in HT29 colon cancer cells by static-magnetic-field (200 mT)-actuated spherical MNPs (100 nm). Herein, we show that similar growth inhibitory effects are induced in other colon cancer cell lines. The effect of magnetomechanical stress was also examined in the growth rate of tumor spheroids. Moreover, we examined the biological mechanisms involved in the observed cell growth inhibition. Under the experimental conditions employed, no cell death was detected by PI (propidium iodide) staining analysis. Flow cytometry and Western blotting revealed that G2/M cell cycle arrest might mediate the antiproliferative effects. Furthermore, MNPs were found to locate in the lysosomes, and a decreased number of lysosomes was detected in cells that had undergone magnetomechanical stress, implying that the mechanical activation of the internalized MNPs could induce lysosome membrane disruption. Of note, the lysosomal acidic conditions were proven to affect the MNPs’ magnetic properties, evidenced by vibrating sample magnetometry (VSM) analysis. Further research on the combination of the described magnetomechanical stress with lysosome-targeting chemotherapeutic drugs could lay the groundwork for the development of novel anticancer combination treatment schemes.

Abstract 5505: ADAM10-targeting CAR-T cells inhibit colon cancer cell growth in vivo

Abstract Chimeric antigen receptor (CAR) T cell therapy has demonstrated a high degree of efficacy in patients with hematological malignancies such as acute lymphatic leukemia. However, its efficacy in solid tumors remains to be demonstrated. There are a number of issues currently limiting therapeutic treatment of solid tumors with CAR-T cells, none more important than target antigen selection. This is a major challenge in solid tumors due to their heterogenous characteristics and the potential for off-cancer effects. ADAM10, A Disintegrin And Metalloproteinase 10, plays critical roles in a wide range of pathophysiological processes during development and inflammation. These proteolytically active multifunctional proteins act as sheddases by cleaving transmembrane-bound proteins such as growth factors, adhesion molecules and chemokine receptors, which can then contribute to migration and invasion of cancer cells. An active form of ADAM10 that has undergone a conformational change has been identified in several cancer types, particularly colorectal cancer. In this study, a novel CAR was generated based on a previously characterized cancer-specific ADAM10 antibody. ADAM-10-targeting CAR-T cells were manufactured using T cells from the peripheral blood of the healthy donors. The CAR-T cells displayed the naïve and central memory phenotype that has been shown to differentiate and proliferate within tumor microenvironments, with little expression of exhaustion markers. These CAR-T cells were capable of killing several human colorectal tumor cell lines in vitro, assessed in a bioluminescence-based cytotoxicity assay. Furthermore, treatment of NSG mice bearing human LoVo colon cancer cell tumors with ADAM-10-targeting CAR-T cells led to significant inhibition of tumor growth compared with either untransduced control T cells or PBS treatment. Overall, these data suggest that targeting ADAM-10 via CAR-T cell therapy is a promising novel avenue of treatment of colorectal cancer. Citation Format: Elaheh Rohani Rad, Jade Foeng, Dylan McPeak, Timona Tyllis, Caitlin Abbott, Veronika bandara, Silvana Napoli, Batjargal gundsambuu, Simon Barry, Timothy Sadlon, shaun McColl. ADAM10-targeting CAR-T cells inhibit colon cancer cell growth in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5505.

Isoalantolactone Enhances the Antitumor Activity of Doxorubicin by Inducing Reactive Oxygen Species and DNA Damage.

Colon cancer is one of the most common cancer in the world. Doxorubicin (DOX) is a classical anti-tumor drug which widely used in treatment of cancers, however, high toxicity limited its further clinical application. Thus, it is urgent to find new drugs with low toxicity and high efficiency to treat colon cancer. Isoalantolactone (IATL), an isomeric sesquiterpene lactone isolated from the plant of inula helenium, has been reported to have anti-cancer activity against a variety of cancer cells. However, the function of IATL in colon cancer remains unclear. Here, we demonstrated that IATL inhibited colon cancer cell growth by increasing cellular reactive oxygen species (ROS) production. Further study showed that ROS accumulation contributed to DNA damage and JNK signaling pathway activation. In addition, we found that IATL markedly enhanced DOX-induced cell cytotoxicity in colon cancer cells. IATL in combination with DOX significantly increased the ROS production, induced DNA damage and activated JNK signaling pathway. Taken together, our data suggested that combined treatment with IATL and DOX may serve as a potential therapeutics for colon cancer.

Alpha-linolenic acid rich Allium porrum methanolic extract potentially inhibits HT-115 human colon cancer cells proliferation via mitochondria mediated apoptotic mechanism

Colon cancer is the third most devastating cancer type in morbidity and mortality associated with severe comorbidities in developing and developed countries. Dietary supplementation of alpha-linolenic acid has a beneficial effect on intestinal dysfunction. In the present study, we processed Allium porrum (Leek) for extraction and identified the bioactive metabolites with the potential of antiproliferative effect in HT-115 (human colon carcinoma) cells. We preliminarily analyzed the cytotoxic effects of methanol, chloroform, and hexane extracts of leek on HT-115 cells. In vitro cytotoxicity assay revealed that leek methanol extract (LME) significantly prohibited cell proliferation in a dose-as well as time-dependent manner, compared with hexane and chloroform extracts of leek. We found that LME at 0.4 and 0.2 μg/mL inhibited HT-115 cell proliferation by 50% at both 24 and 48 h. Cell morphological analysis and nuclear staining indicated that 22% of cells became apoptotic and ∼4% were necrotic after treatment with 0.4 μg/mL of LME. RT-PCR and western blot analysis showed that mRNA and protein expression levels of apoptotic markers such as p53, Bax, caspase-9, and caspase-3 were up-regulated, whereas Bcl-2 was down-regulated in cells exposed with 0.4 μg/mL LME, compared with the levels in untreated control cells. Lipid peroxidation marker (LPO) was significantly elevated in LME-treated cell lysates. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were significantly decreased in LME-treated cell lysates when compared with control HT-115 cells. In conclusion, the observed results demonstrate that LME significantly inhibits colon cancer cell growth via the mitochondria mediated caspase-dependent apoptosis mechanism.

Inoscavin A, a pyrone compound isolated from a Sanghuangporus vaninii extract, inhibits colon cancer cell growth and induces cell apoptosis via the hedgehog signaling pathway

BackgroundSanghuangporus vaninii, a large precious medicinal fungus called Sanghuang in China, has significant antitumor activity. We previously reported that a Sanghuangporus vaninii extract could lead to apoptosis in HT-29 cells through the intrinsic apoptotic pathway. We further found that Inoscavin A exhibited anti-colon cancer activity, but its specific mechanisms have not been fully elucidated. MethodsInoscavin A was obtained from Sanghuangporus vaninii by the classic phytochemical separation technology. The male BALB/c nude mice were injected with HT-29 colon cancer cells as animal model. In order to observe the pathological changes of tumor section, the hematoxylin-eosin(H&E) staining was applied in the histological analysis. Metabolomics was utilized for the investigation of the overall changes of serum metabolites in animal model, and the potential targets of Inoscavin A were analyzed by Ingenuity Pathway Analysis (IPA). We further employed a molecular docking approach to predict the degree of combination of Inoscavin A and Smo. Then we further performed Western blotting and immunofluorescence analysis to investigate the expression of proteins involved in Hh-related pathways in tumor tissues. In addition, the colony formation assay, scratch-wound assay and transwell migration and invasion assay were conducted to evaluate the anti-colon-cancer activity of Inoscavin A. Concurrently, the mitochondrial membrane potential assay and TUNEL apoptosis assay were detected to demonstrate the effect of Inoscavin A on promoting HT-29 cells apoptosis. Western blot experiments verified the anti-tumor effects of Inoscavin A were modulated the protein expression of Shh, Ptch1, Smo and Gli1 in HT-29 cells. ResultsWe showed that Inoscavin A, a pyrone compound isolated from the Sanghuangporus vaninii extract, exerted its antitumor activity in an HT-29 colon cancer cell xenograft mouse model. Subsequently, we first time prove that the antitumor effects of Inoscavin A were related to the hedgehog (Hh) signaling pathway. Furthermore, we demonstrated that Smo, the core receptor of the Hh pathway, was critical for the induction of apoptosis of Inoscavin A and that overexpression of this target could significantly rescue cell apoptosis induced by Inoscavin A treatment. ConclusionThus, our studies first propose that the natural outgrowth Inoscavin A exerted its anti-cancer effects by inhibiting Smo to suppress the activity of the Hh pathway though inhibiting cell proliferation and promoting apoptosis. These findings further indicate that Inoscavin A will be expected to be a prospective remedical compound for the treatment of colon cancer.

Shikonin suppresses colon cancer cell growth and exerts synergistic effects by regulating ADAM17 and the IL‑6/STAT3 signaling pathway.

Signal transducer and activator of transcription 3 (STAT3) activation is associated with drug resistance induced by anti-epidermal growth factor receptor (anti-EGFR) therapy in the treatment of colon cancer. Thus, the combined inhibition of EGFR and STAT3 may prove beneficial for this type of cancer. STAT3 has been proven to play a critical role in colon cancer initiation and progression, and is considered the primary downstream effector driven by interleukin-6 (IL-6). A disintegrin and metalloproteinase 17 (ADAM17), documented as an oncogene, catalyzes the cleavage of both EGF and IL-6R, inducing EGFR signaling and enabling IL-6 trans-signaling to activate STAT3 in a wide range of cell types to promote inflammation and cancer development. As a natural product, shikonin (SKN) has been found to function as an antitumor agent; however, its role in the regulation of ADAM17 and IL-6/STAT3 signaling in colon cancer cells remains unknown. In the present study, it was found that SKN inhibited colon cancer cell growth, suppressed both constitutive and IL-6-induced STAT3 phosphorylation, and downregulated the expression of ADAM17. ADAM17 expression was not altered in response to STAT3 knockdown, while IL-6-induced STAT3 activation did not induce ADAM17 transcripts. Furthermore, it was demonstrated that SKN did not affect the expression of key proteins involved in the maturation and degradation of ADAM17. SKN decreased ADAM17 expression possibly through reactive oxygen species (ROS)-mediated translational inhibition, as evidenced by the increased ADAM17 mRNA and phosphorylation levels of eukaryotic initiation factor 2α (eIF2α). The expression of ADAM17 and p-eIF2α was reversed by N-acetylcysteine (NAC, a ROS scavenger). Taken together, these results indicate that the concurrent inhibition of ADAM17 and IL-6/STAT3 signaling by SKN may synergistically contribute to the suppression of colon cancer cell growth.

Anticancer Activity of Biogenic Selenium Nanoparticles: Apoptotic and Immunogenic Cell Death Markers in Colon Cancer Cells.

Simple SummaryColorectal cancer remains a major health problem worldwide, with high prevalence and mortality rates. Innovative approaches and advanced therapeutic anticancer strategies need to be developed. In this frame, the aim of the present study was to assess the potential of biogenic selenium nanoparticles, produced by a probiotic microorganism, to induce apoptotic and immunogenic cell death in colon cancer cell lines. The findings of the present study confirmed that treatment of colon cancer cell lines with selenium nanoparticles induced pro-apoptotic and immunogenic cell death markers (indicating immunogenic cell death) and highlighted their potential to provide an efficient strategy for destroying tumour cells not only directly by apoptotic cell death, but also indirectly through enhanced immunogenicity.Colorectal cancer is a health problem with high mortality rates and prevalence. Thus, innovative treatment approaches need to be developed. Biogenic nanoparticles are nanomaterials that can be synthesised in biological systems and, compared to chemically synthesised nanoparticles, have better bioavailability while being more cost-effective, eco-friendlier, and less toxic. In our previous studies, the probiotic strain Lactobacillus casei ATCC 393 was used to synthesise selenium nanoparticles (SeNps), which were shown to inhibit colon cancer cell growth in vitro and in vivo. Herein, we have further investigated SeNps’ pro-apoptotic activity and their ability to induce immunogenic cell death (ICD) in colon cancer cells. The SeNps’ effect on Caco-2 cells growth was examined along with their potential to induce caspase activation. Moreover, the expression of typical pro-apoptotic and ICD markers were examined in SeNps-treated HT29 and CT26 cells by flow cytometry, Western blot, ELISA and fluorescence microscopy. Elevated caspase-3 activation and surface phosphatyldoserine, that subsided upon co-incubation with a pan-caspase inhibitor, were detected in SeNps-treated cells. Furthermore, nanoparticles induced modulation of the expression of various apoptosis-related proteins. We also report the detection of biomarkers involved in ICD, namely the translocation of calreticulin and ERp57, the release of HMGB1 and ATP, and the secretion of pro-inflammatory cytokines from SeNps-treated cells. Moreover, RAW246.7 macrophages exhibited a higher rate of phagocytosis against treated CT26 when compared to control cells. Taken together, our findings indicate that treatment with SeNps might be an efficient strategy to destroy tumour cells by inducing apoptotic cell death and triggering immune responses.

Recombinant water stress protein 1 (Re-WSP1) suppresses colon cancer cell growth through the miR-539/β-catenin signaling pathway.

Nostoc commune Vauch. is a nitrogen-fixing blue-green algae that expresses a large number of active molecules with medicinal properties. Our previous study found that a water stress protein (WSP1) from N. commune and its recombinant counterpart (Re-WSP1) exhibited significant anti-colon cancer activity both in vitro and in vivo. This study is to investigate the effects of Re-WSP1 on proliferation of colon cancer cells and to elucidate the relevant mechanisms. Real-time quantitative PCR was used to detect the expression of miR-539 in colon cancer HT-29 and DLD1 cells. Colon cancer cells were transfected with miR-539 mimics and negative controls, and cell proliferation were detected by CCK8 and clonogenic assays. The target gene of miR-539 was predicted, and the dual luciferase reporter gene experiment was used to verify the target gene. After colon cancer cells were transfected with miR-539 mimics or inhibitors, the expression of target gene β-catenin was detected by Western blot. miR-539 inhibitor confirmed cell proliferation. Re-WSP1 inhibited colon cancer cell growth in a dose-dependent manner. Re-WSP1 inhibited the expression of β-catenin, which was partly reversed by LiCl treatment. Quantitative PCR analysis showed that the expression of miR-539 was significantly upregulated after Re-WSP1 treatment. Moreover, miR-539 negatively regulated the expression of β-catenin by directly binding to the 3'UTR of β-catenin mRNA. The cell growth inhibition and the decrease in β-catenin expression induced by Re-WSP1 were significantly reversed by miR-539 inhibitor. Re-WSP1 suppresses colon cancer cell growth via the miR-539/β-catenin axis.

Suppression of Colon Tumorigenesis in Mutant Apc Mice by a Novel PDE10 Inhibitor that Reduces Oncogenic β-Catenin.

Previous studies have reported that phosphodiesterase 10A (PDE10) is overexpressed in colon epithelium during early stages of colon tumorigenesis and essential for colon cancer cell growth. Here we describe a novel non-COX inhibitory derivative of the anti-inflammatory drug, sulindac, with selective PDE10 inhibitory activity, ADT 061. ADT 061 potently inhibited the growth of colon cancer cells expressing high levels of PDE10, but not normal colonocytes that do not express PDE10. The concentration range by which ADT 061 inhibited colon cancer cell growth was identical to concentrations that inhibit recombinant PDE10. ADT 061 inhibited PDE10 by a competitive mechanism and did not affect the activity of other PDE isozymes at concentrations that inhibit colon cancer cell growth. Treatment of colon cancer cells with ADT 061 activated cGMP/PKG signaling, induced phosphorylation of oncogenic β-catenin, inhibited Wnt-induced nuclear translocation of β-catenin, and suppressed TCF/LEF transcription at concentrations that inhibit cancer cell growth. Oral administration of ADT 061 resulted in high concentrations in the colon mucosa and significantly suppressed the formation of colon adenomas in the Apc+/min-FCCC mouse model of colorectal cancer without discernable toxicity. These results support the development of ADT 061 for the treatment or prevention of adenomas in individuals at risk of developing colorectal cancer. PREVENTION RELEVANCE: PDE10 is overexpressed in colon tumors whereby inhibition activates cGMP/PKG signaling and suppresses Wnt/β-catenin transcription to selectively induce apoptosis of colon cancer cells. ADT 061 is a novel PDE10 inhibitor that shows promising cancer chemopreventive activity and tolerance in a mouse model of colon cancer.

Multilevel regulation of Wnt signaling by Zic2 in colon cancer due to mutation of \u03b2-catenin

Zinc-finger of the cerebellum 2 (Zic2) is widely implicated in cancers, but the role of Zic2 in tumorigenesis is bilateral. A recent study indicated that Zic2 could render colon cancer cells more resistant to low glucose-induced apoptosis. However, the functional roles of Zic2 in colon cancer and the underlying molecular mechanism remain elusive. Herein, we demonstrated that Zic2 was highly expressed in colon cancer tissues and correlated with poor survival. Knockdown of Zic2 inhibited colon cancer cell growth, arrested the cell cycle transition from G0/G1 to S phase, and suppressed tumor sphere formation in vitro; in addition, silencing Zic2 retarded xenograft tumor formation in vivo. Consistently, ectopic expression of Zic2 had the opposite effects. Mechanistically, Zic2 executed its oncogenic role in colon cancer by enhancing Wnt/β-catenin signaling. Zic2 directly binds to the promoter of Axin2 and transcriptionally represses Axin2 expression and subsequently promotes the accumulation and nuclear translocation of β-catenin. Meanwhile, Zic2 could activate Wnt signaling by interacting with β-catenin. Intriguingly, in HCT116 cells with intrinsic Ser45 mutation of β-catenin, which blocks the degradation-related phosphorylation of β-catenin by CK1, modified Zic2 expression did not affect the protein level of β-catenin. Altogether, our findings uncover a novel multilevel mechanism for the oncogenic activity of Zic2 in colon cancer and suggest Zic2 as a potential therapeutic target for colon cancer patients.

Microencapsulated Bifidobacterium bifidum and Lactobacillus gasseri in Combination with Quercetin Inhibit Colorectal Cancer Development in ApcMin/+ Mice.

Recent studies have suggested that flavonoids such as quercetin and probiotics such as Bifidobacterium bifidum (Bf) and Lactobacillus gasseri (Lg) could play a relevant role in inhibiting colon cancer cell growth. Our study investigated the role of dietary supplementation with microencapsulated probiotics (Bf and Lg) along with quercetin in the development of mouse colorectal cancer (CRC). Methods: Adenomatous polyposis coli/multiple intestinal neoplasia (ApcMin/+) mice were fed a standard diet or the same diet supplemented with microencapsulated probiotics (Bf and Lg strains, 107 CFU/100 g food) or both probiotics strains plus microencapsulated quercetin (15 mg/100 g food) for 73 days. Changes in body and organ weights, energy metabolism, intestinal microbiota, and colon tissue were determined. The expression of genes related to the Wnt pathway was also analyzed in colon samples. Results: Dietary supplementation with microencapsulated probiotics or microencapsulated probiotics plus quercetin reduced body weight loss and intestinal bleeding in ApcMin/+ mice. An improvement in energy expenditure was observed after 8 weeks but not after 10 weeks of treatment. A supplemented diet with microencapsulated Bf and Lg reduced the number of aberrant crypt foci (ACF) and adenomas by 45% and 60%, respectively, whereas the supplementation with Bf, Lg and quercetin decreased the number of ACF and adenomas by 57% and 80%, respectively. Microencapsulated Bf and Lg in combination with quercetin could exert inhibition of the canonical Wnt/β-catenin signaling pathway in the colon of ApcMin/+ mice Conclusions: The administration of microencapsulated Bf and Lg, individually or in combination with quercetin, inhibits the CRC development in ApcMin/+ mice.