C26 Murine Colon Carcinoma Cells Research Articles

A Multifunctional Nanotherapy for Targeted Treatment of Colon Cancer by Simultaneously Regulating Tumor Microenvironment.

Colitis-associated colon cancer (CAC) is a widely recognized cancer, while treatment with the existing chemotherapeutic drugs affords limited clinical benefits. Herein we proposed a site-specific, combination nanotherapy strategy for targeted treatment of CAC by the oral route.Methods: A reactive oxygen species (ROS)-responsive and hydrogen peroxide-eliminating material OCD was synthesized, which was further produced into a functional nanoparticle (OCD NP). The antioxidative stress and anti-inflammatory effects of OCD NP were examined by in vitro and in vivo experiments. By packaging an anticancer drug camptothecin-11 (CPT-11) into OCD NP, a ROS-responsive nanotherapy CPT-11/OCD NP was obtained, and its antitumor activity was evaluated by both in vitro and in vivo studies. Preliminary safety studies were also performed for CPT-11/OCD NP in mice.Results: OCD NP significantly attenuated oxidative stress and inhibited inflammatory response in different cells and mice with induced colitis. CPT-11/OCD NP could selectively release drug molecules under intestinal pH conditions and at high levels of ROS. In C26 murine colon carcinoma cells, this nanotherapy showed significantly higher antitumor activity compared to free CPT-11 and a non-responsive CPT-11 nanotherapy. Correspondingly, oral delivery of CPT-11/OCD NP notably inhibited tumorigenesis and tumor growth in mice with induced CAC. By combination therapy with the nanovehicle OCD NP in the inflammatory phase, more desirable therapeutic effects were achieved. Furthermore, CPT-11/OCD NP displayed excellent safety profile for oral administration at a dose that is 87.3-fold higher than that employed in therapeutic studies.Conclusions: Anticancer nanotherapies derived from intrinsic anti-inflammatory nanocarriers are promising for targeted combination treatment of inflammation-associated tumors by simultaneously shaping pro-inflammatory microenvironment toward a relatively normal niche sensitive to chemotherapy.

Self-Assembled Metal-Phenolic Nanoparticles for Enhanced Synergistic Combination Therapy against Colon Cancer.

Engineering functional nanomaterials to have both high therapeutic efficacy and minimal side-effects has become a promising strategy for next-generation cancer treatments. Herein, an adenosine triphosphate (ATP) depletion and reactive oxygen species-enhanced combination chemotherapy platform is introduced whereby therapeutic samarium (Sm3+ ) ions and (-)-epicatechin (EC) are integrated via a metal-phenolic network (SmIII -EC). The independent pathway between Sm3+ and EC can achieve a synergistic therapeutic effect through the mitochondrial dysfunction process. SmIII -EC nanoparticles cause a significant reduction of viability of C26 murine colon carcinoma cells while with lower systemic toxic effects on normal cell lines. SmIII -EC nanoparticles are used to directly compare with a clinic anticancer drug 5-fluorouracil. SmIII -EC nanoparticles not only decrease the tumor volume but also do not affect the body weight of mice and normal organs, showing significant advantages over clinic counterpart. These facts suggest that SmIII -EC nanoparticles represent a clinically promising candidate for colon cancer treatment with a targeted therapeutic effect and minimum side toxicity.

Liposomal prednisolone phosphate potentiates the antitumor activity of liposomal 5-fluorouracil in C26 murine colon carcinoma in vivo

ABSTRACTThe antitumor efficacy of 5-fluorouracil (5-FU) in advanced colorectal cancer (CRC) is hindered not only by the low therapeutic index, but also by tumor cell resistance to this cytotoxic drug. Therefore, to enhance the 5-FU antitumor activity, the present research used a novel tumor-targeted therapy based on the co-administration of 5-FU encapsulated in long-circulating liposomes (LCL-5-FU) together with liposomal prednisolone phosphate (LCL-PLP), a formulation with known anti-angiogenic actions on C26 murine colon carcinoma cells. Thus, we assessed the in vivo effects of the combined liposomal drug therapy on C26 carcinoma growth as well as on the production of molecular markers with key roles in tumor development such as angiogenic, inflammatory, and oxidative stress molecules. To get further insight into the polarization state of tumor microenvironment after the treatment, we determined the IL-10/IL-12p70 ratio in tumors. Our results showed that combined liposomal drug therapy inhibited almost totally tumor growth and was superior as antitumor activity to both single liposomal drug therapies tested. The antitumor efficacy of the combined therapy was mainly related to the anti-angiogenic and anti-inflammatory actions on C26 carcinoma milieu, being favored by its controlling effect on intratumor oxidative stress and the skewing of polarization of tumor microenvironmental cells toward their antineoplastic phenotypes. Thus, our study unveils a promising treatment strategy for CRC that should be furthermore considered.

Optimization of prednisolone-loaded long-circulating liposomes via application of Quality by Design (QbD) approach

Quality by design principles (QbD) were used to assist the formulation of prednisolone-loaded long-circulating liposomes (LCL-PLP) in order to gain a more comprehensive understanding of the preparation process. This approach enables us to improve the final product quality in terms of liposomal drug concentration, encapsulation efficiency and size, and to minimize preparation variability. A 19-run D-optimal experimental design was used to study the impact of the highest risk factors on PLP liposomal concentration (Y1- μg/ml), encapsulation efficiency (Y2-%) and size (Y3-nm). Out of six investigated factors, four of them were identified as critical parameters affecting the studied responses. PLP molar concentration and the molar ratio of DPPC to MPEG-2000-DSPE had a positive impact on both Y1 and Y2, while the rotation speed at the formation of the lipid film had a negative impact. Y3 was highly influenced by prednisolone molar concentration and extrusion temperature. The accuracy and robustness of the model was further on confirmed. The developed model was used to optimize the formulation of LCL-PLP for efficient accumulation of the drug to tumor tissue. The cytotoxicity of the optimized LCL-PLP on C26 murine colon carcinoma cells was assessed. LCL-PLP exerted significant anti-angiogenic and anti-inflammatory effects on M2 macrophages, affecting indirectly the C26 colon carcinoma cell proliferation and development.

Growth inhibition effects of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid on colorectal carcinoma cells and colon carcinoma-bearing mice.

The aim of the present study was to investigate the mechanism underlying the antitumor effects of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) in colorectal cancer (CRC). 5F was isolated and used to treat C26 murine colon carcinoma cells, a xenograft tumor mouse model (induced by C26 cells) and a CRC mouse model [induced by 1,2-dimethylhydrazine (DMH)/dextran sodium sulfate (DSS)]. C26 cell growth was inhibited by 5F in a dose- and time-dependent manner in vitro. In addition, 5F induced cell apoptosis and cell cycle arrest in the G2 phase, increased the activity of caspase-3 and caspase-9, but did not affect the activity of cascase‑8, suggesting that 5F induced apoptosis via activation of the mitochondrial signaling pathway rather than the death‑receptor signaling pathway. Furthermore, treatment of C26 cells with 5F resulted in upregulation of cyclin‑dependent kinase inhibitor 1A (p21, Cip1), Bcl‑2‑associated X protein, nuclear factor of κ light polypeptide gene enhancer in B‑cells inhibitor, α and downregulation of B‑cell lymphoma 2, nuclear factor κ‑light‑chain enhancer of activated B cells and survivin. In vivo animal models demonstrated that 5F treatment protected mice from carcinogenesis induced by DMH/DSS and markedly decreased the xenograft tumor weight with minimal side effects. Therefore, 5F may have potential as an anti-CRC therapeutic agent for use in the clinical setting.

Biosynthesized silver nanoparticles performing as biogenic SERS-nanotags for investigation of C26 colon carcinoma cells

In this work, two classes of silver nanoparticles (AgNPs) were biosynthesized with the goal to assess their reliability in vitro as surface-enhanced Raman scattering (SERS) nanotags. Mycosynthesized silver nanoparticles (MAgNPs) and phytosynthesized silver nanoparticles (PAgNPs) were produced through environmentally friendly procedures by reduction of silver nitrate with Fusarium oxysporum cell filtrate and Azadirachta indica extract, respectively. Two cell lines, namely C26 murine colon carcinoma cells as example of cancer cells and human immortalized keratinocyte cells (HaCaT) as representative of healthy cell line, were selected for in vitro investigation. The in vitro toxicity studies show that M(P)AgNPs present lower cytotoxic effect on both cell lines as compared with standard citrate coated AgNPs. The internalization of M(P)AgNPs by colon carcinoma cells and structural alterations induced in the morphology of treated cells were analyzed by dark-field (DF) and differential interference contrast (DIC) microscopy, respectively. The most informative data about the cellular uptake and tracking potential of M(P)AgNPs were provided by scanning Confocal Raman Microscopy (CRM) and multivariate K-means cluster analysis of collected Raman spectra. The analysis reveals the subcellular components and the localization of AgNPs inside the cell via the intrinsic SERS signature of biogenic coating material. The use of unique biological material to perform synthesis, stability, biocompatibility and SERS tagging is relevant both from the point of view of encoding nanoparticles with Raman reporters and further applications in cell investigation via Raman/SERS imaging.

Hydroquinone analog 4-[(Tetrahydro-2H-pyran-2‑yl)oxy]phenol induces C26 colon cancer cell apoptosis and inhibits tumor growth invivo.

The 4[(Tetrahydro‑2H‑pyran‑2‑yl) oxy] phenol (XG‑d) hydroquinone analog, is found in Vaccinium vitis‑idaea L. Although it is known for its antioxidant properties and high level of safety, its antitumor activity remains to be elucidated. In the present study, the anticancer effect of XG‑d was determined invitro and invivo. The cytotoxicity of XG‑d against C26 murine colon carcinoma cells was found to occur in a time‑ and concentration‑dependent manner, whereas little effect was observed in the two normal cell lines (HK‑2 and L02) investigated. Oral administration of XG‑d (100mg/kg) had effects on the tumor growth of tumor‑bearing mice. Furthermore, marked apoptosis was observed using Hoechst33258 staining and flow cytometric analysis with annexinV/propidium iodide double staining. XG‑d also downregulated the expression of B‑cell lymphoma2 (Bcl‑2), increased the expression levels of Bcl‑2‑associated Xprotein and activated caspase‑9, caspase‑3 and poly(adenosine diphosphate‑ribose) polymerase. The present study demonstrated for the first time, to the best of our knowledge, that XG‑d inhibited cancer cell growth via the induction of apoptosis and was also able to inhibit tumor growth invivo. These results demonstrated that XG‑d may be used as a potential natural agent for cancer therapy with low toxicity.

Abstract B10: LFA-1/ICAM-1 interaction switches on an orchestrated prometastatic microenvironmental shift during experimental liver metastasis of colon C26 cancer cells.

Abstract Intercellular adhesion molecule (ICAM)-1 is the main counter-receptor for the lymphocyte function associated antigen (LFA)-1. However, the role this interaction plays during liver metastasis of colorectal cancer cells and its underlying mechanisms remain unclear. Previously, we showed that mannose receptor (ManR) stimulation on liver sinusoidal endothelial cells (LSECs) resulted in a reduced cytotoxic potential of liver infiltrating lymphocytes (LIL) towards C26 murine colon carcinoma cells. Using ICAM-1 specific siRNAs in vivo, we aimed to study the role of hepatic ICAM-1 in the prometastatic shift of the liver microenvironment. Livers of control and silenced mice, 24 hours and 14 days after C26 cell inoculation, were compared for: percentage of detained C26 cells, number and volume of metastatic foci, levels of recruited immune, myofibroblastic and inflammatory cells and whole liver expression of pro-inflammatory genes. Detained cancer cells and metastatic foci number were reduced in silenced mice compared to controls, along with a decrease in myeloid suppressor cells and recruited macrophages and myofibroblasts. On the contrary, significant higher numbers of lymphocytic cells were observed in mice with reduced ICAM-1. Finally, silencing of ICAM1 resulted in altered total liver mRNA levels of proinflammatory factors in the tumor-bearing mice. Therefore, an orchestrated prometastatic program might be switched on in the liver microenvironment by LFA-1/ICAM-1 interaction which, in turn, could lead not only to a reduced antitumor citotoxicity but, also, to activation of the stromal compartment favoring tumor progression, and, opening liver's doors to tumor cells to aggressively metastasize. Based on these results, LFA-1/ICAM-1 interaction arises as a potential therapeutic target in cancer treatment. Citation Format: Aitor Benedicto, Joana Marquez, Elvira Olaso, Beatriz Arteta. LFA-1/ICAM-1 interaction switches on an orchestrated prometastatic microenvironmental shift during experimental liver metastasis of colon C26 cancer cells.. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr B10. doi:10.1158/1538-7445.CHTME14-B10

Optimizing long-circulating liposomes for delivery of simvastatin to C26 colon carcinoma cells

Simvastatin (SIM) is a lipophilic statin that has potential benefits for prevention and treatment of several types of malignancies. However, its low water solubility and the toxicity associated with administration of high doses recommend it for encapsulation in carriers able to deliver the therapeutic dose in the tumor. In this work, liposomes with long-circulating properties were proposed as delivery systems for SIM. The objective of this study was to optimize the formulation of SIM-loaded long-circulating liposomes (LCL-SIM) by using D-optimal experimental design. The influence of phospholipids concentration, phospholipids to cholesterol molar ratio and SIM concentration was studied on SIM liposomal concentration, encapsulation efficiency and liposomal size. The optimized formulation had liposomal SIM concentration 6238 µg/ml, EE % of 83.4 % and vesicle size of 190.5 nm. Additionally we evaluated the in vitro cytotoxicity of the optimized liposomal SIM (LCL-SIM-OPT) on C26 murine colon carcinoma cells cultivated in monoculture as well as in co-culture with murine peritoneal macrophages at a cell density ratio that provides an approximation of physiological conditions of colon carcinoma development in vivo. Our preliminary studies suggested that LCL-SIM-OPT exerted cytotoxicity on C26 cells probably via enhancement of oxidative stress in co-culture environment.

Erythromycin inhibits the proliferation of HERG K+ channel highly expressing cancer cells and shows synergy with anticancer drugs

To investigate the effects of erythromycin on the proliferation of the human ether-a-go-go related gene (HERG) K(+) channel highly expressing cancer cells and its synergy with antitumor chemotherapeutic agents. Human fibrosarcoma cell of the line HT-1080, murine colon carcinoma cells of the line C26, human colon carcinoma cells of the line HT-29, human pulmonary epithelial cells of the line A549, and human neuroblastoma cells of the line SH-SY5Y were cultured. Western blotting was used to detect the protein expression of the HERG K(+) channel protein. Erythromycin, taxol, and vincristine were added into the culture fluid. to observe the proliferation of the cancer cells. Collagen I was used to coat 96-well plate, HT-29 cells were put into, and Erythromycin, taxol, and vincristine were added, MTT method was used to examine the cell adhesion. SDS-PAGE was used to detect the secretion of gelatinase. Flow cytometry was used to detect the cell cycle and apoptosis. The coefficient of drug interaction (CDI) was calculated. HERG K(+) channel expression was found in both HT-29 human colon carcinoma cells and C26 murine colon carcinoma cells. The expression level in HT-29 cells was higher than that in the positive control SHSY5Y neuroblastoma cells. Erythromycin suppressed the proliferation of HT-29 and C26 cells in a dose-dependent manner. There existed a remarkable G(2)/M arrest after the cells were exposed to erythromycin. Induction of apoptosis in HT-29 cells and inhibition of cell adhesion to collagen I were found. Erythromycin inhibited the secretion of MMP-2 from HT-29 cells in a dose-dependent manner. At sub-cytotoxic concentration, erythromycin potentiated the cytotoxicity of vincristine, taxol, and hydroxyl-camptothecin to C26 cells. The IC(50) values for vincristine and vincristine plus erythromycin (50 micromol/L) were 62.65 nmol/Land and 4.68 nmol/L respectively. Erythromycin inhibits the proliferation and induces the apoptosis of cancer cells with high HERG K(+) channel expression. Synergy is found in the combination of erythromycin with other anticancer agents.

Enhancement of 5-fluorouracil cytotoxicity by human thymidine-phosphorylase expression in cancer cells: in vitro and in vivo study.

Transferring a gene into cancer cells in order to sensitize them to drugs is an important approach in human cancer gene-therapy research. Thymidine phosphorylase (TP) is the first enzyme in the metabolic activation pathway of 5-fluorouracil (5-FU) to fluorodeoxyribonucleotides, thus, it could be used to increase the sensitivity of cancer cells to this anti-pyrimidine agent. In this study, an expression vector containing the human TP cDNA was transfected into C26 murine colon-carcinoma cells. Stable transfectants were selected; all showed increased TP activity, ranging from 2- to 10-fold when compared with wild-type cells. The in vitro sensitivity of transfectants to 5-FU and 5'-deoxy-5-fluorouridine (5'-DFUR) was enhanced, in agreement with the observed increase in TP activity. Then, tumors were generated by s.c. injection of TP-transfected or wild-type C26 cells in syngeneic BALB/c mice. 5-FU (25 mg/kg, i.p.) induced a growth delay of TP-transfected C26 tumors as compared with C26 wild-type tumors. These data suggest that TP could be transfected in tumor cells to increase the sensitivity to 5-FU for subsequent cancer gene therapy.