CT26 Colon Cancer Research Articles

Amide Derivative of Arjunolic Acid TA-1,4-BiP Enhances ROSmediated Apoptosis in Colorectal Cancer Cells.

Arjunolic acid, a well-known natural product with various medicinal properties, was isolated from the heartwood of Terminalia arjuna. Various amides of arjunolic acid were synthesized using different aryl and cyclic amines, characterized, and evaluated for their anti-cancer activities at the National Cancer Institute (NCI). All the derivatives were active against all the cell lines of NCI compared to the parent molecule arjunolic acid. Eight compounds were selected for dose-dependent activity based on the preliminary results. IC50 of selected eight compounds was evaluated. Based on IC50 values against various cell lines, compound 2l was further investigated to understand the mechanism of action against HCT-116 and CT-26 colon cancer cell lines. Mechanistic studies of compound 2l in these two cell lines demonstrated that compound 2l arrested the colon cancer cells at the G/G1 phase. Compound 2l-treated cells were also found to have an increased percentage of ROS compared to untreated cells. It induced apoptosis in both these cell lines. Compound 2l was found to inhibit cancer growth in the mice model and was very effective against all the cancer cell lines. Therefore, it could be used for further development to treat colon cancer.

Expression, characterization and anti-colon cancer activity of recombinant ginseng peptides with amino acid tandem repeats.

Ginseng peptides, small molecule active ingredients in ginseng, are mainly extracted naturally or synthesised chemically, but high costs and difficulties hinder further research. In this study, a ginseng hexapeptide FKEHGY, named antitumor peptide 0601 (AT0601) and its five tandem sequence repeats AT0605, were expressed in Bacillus subtilis WB600 for the first time, and the bioactivity study showed that the anticancer activity of AT0605 was even significantly higher than that of AT0601 for colon cancer CT26 cells, with IC50s of 16.82±1.3 μM (48 h) and 855.57±6.04 μM (48 h), respectively, i.e. AT0605 achieves the same inhibition rate for CT26 cells at a concentration 50 times lower than that of AT0601. Similar to the ginseng peptide AT0601, recombinant AT0605 also inhibited cell growth by blocking cells in the G1 phase and activated the mitochondria-associated caspase pathway to induce apoptosis. In conclusion, all two kinds of the recombinant ginseng peptides could also inhibit cell proliferation through mechanisms such as inhibiting cell cycle arrest and inducing a decrease in mitochondrial membrane potential.

Research on curcumin mediating immunotherapy of colorectal cancer by regulating cancer associated fibroblasts.

The objective was to investigate curcumin's (Cur) function and associated molecular mechanisms in regulating tumor immunity in colon cancer. Primary cancer-associated fibroblasts (CAFs) from mouse CT26 colon cancer tumors were isolated. Validation of primary CAFs using immunofluorescence assay was done. Cell Counting Kit-8 experiments, real-time quantitative PCR (qPCR), and enzyme linked immunosorbent assay experiments were conducted to investigate how curcumin affected the growth and cytokine secretion functions of CAFs. The effect of curcumin on regulating PD-L1 expression on CT26 cells through CAFs in vitro was explored through coculture of CAFs and tumor cells, qPCR, and western blot experiments. A mouse colon cancer cell model was established in Balb/c nude mice to explore the effect of curcumin on colon tumor cells. Changes in the tumor microenvironment were detected by flow cytometry to explore the synergistic effect of curcumin combined with anti-PD-1 monoclonal antibody in the treatment of mouse colon cancer. In vitro, curcumin prevented the growth and TGF-β secretion of CT26 cells. At the same time, curcumin inhibited the secretion of TGF-β by CAFs, thereby downregulating the PD-L1 expression of CT26 cells. In vivo, curcumin combined with anti-PD-1 antibodies can further enhance the inhibitory effect of PD-1 antibodies on tumors and increase the number of tumor-suppressing immune cells in the tumor microenvironment, such as M1 macrophages and CD8 T cells, thus inhibiting tumors. Immune M2 macrophages, regulatory T cells, and other cells were reduced. In conclusion, curcumin reduces the expression of PD-L1 in colon cancer cells and improves the tumor immune microenvironment by inhibiting the proliferation of CAFs and the secretion of TGF-β. Curcumin and anti-PD-1 treatment have synergistic inhibitory effects on colon cancer.

PPARδ Antagonist Inhibited CD47 Expression and Phagocytosis.

Increasing evidence suggests that CD47 is highly expressed in multiple types of cancer, which could bind to SIRPα on macrophage, leading to inhibition of macrophage phagocytosis and promotion of tumor growth. However, the regulatory mechanism of CD47 gene expression is not completely clear. Our results indicated that colon cancer cells treated with GSK0660 drug, which is one of the PPARδ antagonists, significantly reduced CD47 gene and protein expression levels in a time and dose-dependent manner. CD47 reporter plasmid was constructed and dual-luciferase analysis was performed. The results suggest that GSK0660 treatment markedly reduced CD47 gene transcriptional activity. Moreover, co-cultured analysis showed that GSK0660 treatment increased phagocytosis. BALB/C mice implanted with CT-26 colon cancer cells were treated with GSK0660, and the results showed that GSK0660 significantly inhibited tumor growth. Moreover, the combination of CD47 monoclonal antibody with GSK0660 drug significantly inhibited tumor growth compared to GSK0660 or CD47 antibody treatment alone. These findings suggest that GSK0660 synergized with CD47 antibody to enhance antitumor immunotherapy.

Concise Three Step Synthesis of the Bioactive Alkaloid Huajiaosimuline via a Zn(OTf)2-Promoted Meinwald Rearrangement.

The synthesis of the biologically active alkaloid huajiaosimulne, isolated from the roots of Zanthoxylum simulans, is reported. The natural product was assembled from simple commercial reagents via initial domino Knoevenagel/oxa-6π-electrocyclization followed by epoxidation and an epoxide/ketone rearrangement promoted by Zn(OTf)2. In vitro cytotoxicity assays identified natural products huajiaosimuline and simulansine as moderate antiproliferative agents against murine colon cancer CT26 cells.

Chrysanthemum indicum L. ameliorates muscle atrophy by improving glucose tolerance in CT26-induced cancer cachexia.

Cancer cachexia is associated with various metabolic mechanisms such as inflammatory response, insulin resistance, and increased muscle proteolysis. However, effective treatment methods have not yet been standardized. Chrysanthemum indicum L. (CI) is a perennial plant belonging to the Asteraceae family, and its flowers have been used for the treatment of headaches, colds, and rhinitis in Asia. This study investigated the effect of CI on cancer cachexia. We subcutaneously injected CT26 colon cancer cells (5 × 105 cells/mouse) into the right flank of BALB/c mice. After 1week, the mice were orally administered vehicle, CI (100mg/kg), or Celecoxib (50mg/kg) for 3weeks. CI improved loss of body weight and impaired glucose tolerance, but celecoxib did not recover the body weight and glucose intolerance. CI not only improved the decreased myofiber diameters but also inhibited muscle protein degradation factors, MAFbx and MuRF1. CI also increased cellular membrane GLUT4 in CT26 conditioned medium-treated C2C12 myofibers and cancer cachexia-induced mice. Furthermore, we found that linarin, a constituent of CI, was responsible for the improvement of muscle atrophy. Our findings indicate that CI can ameliorate muscle atrophy by improving glucose uptake, suggesting that CI could be a therapeutic agent for cancer cachexia.

The HDAC6 inhibitor AVS100 (SS208) induces a pro-inflammatory tumor microenvironment and potentiates immunotherapy.

Histone deacetylase 6 (HDAC6) inhibition is associated with an increased pro-inflammatory tumor microenvironment and antitumoral immune responses. Here, we show that the HDAC6 inhibitor AVS100 (SS208) had an antitumoral effect in SM1 melanoma and CT26 colon cancer models and increased the efficacy of anti-programmed cell death protein 1 treatment, leading to complete remission in melanoma and increased response in colon cancer. AVS100 treatment increased pro-inflammatory tumor-infiltrating macrophages and CD8 effector T cells with an inflammatory and T cell effector gene signature. Acquired T cell immunity and long-term protection were evidenced as increased immunodominant T cell clones after AVS100 treatment. Last, AVS100 showed no mutagenicity, toxicity, or adverse effects in preclinical good laboratory practice studies, part of the package that has led to US Food and Drug Administration clearance of an investigational new drug application for initiating clinical trials. This would be a first-in-human combination therapy of pembrolizumab with HDAC6 inhibition for locally advanced or metastatic solid tumors.

Ultrasound-Responsive Lipid Nanoplatform with Nitric Oxide and Carbon Monoxide Release for Cancer Sono-Gaso-Therapy.

Local gas therapy is emerging as a potential cancer treatment approach due to its specificity as gas-containing molecules can be packed into a nanodelivery system to release the corresponding gaseous molecules around the tumor site upon a suitable stimulus. Single-gas therapy has been reported, while synergistic dual-gas therapy has rarely been reported. Herein, we report a dual-gas-containing nanoplatform for synergistic cancer gasotherapy upon ultrasound irradiation. First, a robust ultrasound-responsive lipid-coated nanosystem was prepared with suitable particle size and characteristics. A low-intensity ultrasound (1.25 W/cm2) was found to simultaneously modulate carbon monoxide (CO) and nitric oxide (NO) release from the nanosystem in media and CT26 colon cancer cells for efficient therapeutic effect. The intracellular release promoted the overgeneration of reactive oxygen species (ROS) and triggered cancer cell apoptosis synergistically. The in vivo test demonstrated that the optimal dual-gas-containing formulation efficiently inhibited tumor growth (by ∼87%) at relatively low doses upon ultrasound irradiation (1.25 W/cm2, 5 min). This therapeutic efficacy shows that the current responsive lipid-coated delivery system has potential for ultrasound-triggered dual-gas therapy of both superficially and deeply seated cancers.

Mitigating the skin phototoxicity of sonodynamic therapy via singlet oxygen-consuming metal-organic frameworks

Sonodynamic anti-cancer therapy relies on the highly active singlet oxygen to induce potent cell death. However, the non-specific biodistribution of sonosensitizers post systemic administration results in a significant accumulation in the skin, and hence the daylight-induced phototoxicity. Here, we report a smart metal-organic framework-based nanocarrier with titanium dioxide (TiO2) as the sonosensitizer for reduced phototoxicity in the skin. The organic ligand bears the imidazole moiety that can facilely consume singlet oxygen in the skin without compromising the anti-cancer efficacy. The reaction between imidazole moiety and singlet oxygen was confirmed by the density functional theory (DFT). Upon light irradiation, the nanocarrier can significantly reduce the phototoxicity post light irradiation in a range of normal cells in vitro and in a mouse model in vivo. Meanwhile, the ligand contains a disulfide moiety that can deplete glutathione and orchestrate the singlet oxygen-induced toxicity in the CT-26 colon cancer cells. As a result, the nanocarrier showed superior in vivo antitumor efficacy in a CT-26 tumor-bearing mice model, leading to significant suppression of tumor growth and improved animal survival rates. The current work provides a tailored nanoscale particle engineering approach to simultaneously minimize phototoxicity in the skin and sensitize sonodynamic anti-cancer therapy.

Resistance Training and Resveratrol Supplementation Improve Cancer Cachexia and Tumor Volume in Muscle Tissue of Male Mice Bearing Colon Cancer CT26 Cell Tumors.

Losing muscle functions due to reducing muscle mass and quality is one of the main features of cancer cachexia that impairs patients' quality of life and decrease their survival. This study aimed to investigate the synergistic effects of resistance training and resveratrol supplementation on cachexia induced by CT26 tumors in male mice. Forty-eight mice were divided into eight groups randomly: healthy sedentary vehicle (HSV), healthy exercise vehicle (HEV), healthy sedentary resveratrol (HSR), healthy exercise resveratrol (HER), CT-26 tumor-bearing sedentary vehicle (TSV), CT-26 tumor-bearing exercise vehicle (TEV), CT-26 tumor-bearing sedentary resveratrol (TSR) and CT-26 tumor-bearing exercise resveratrol (TER). Training groups performed ladder climbing with weights tied to their tails, for six weeks. Resveratrol-treated groups received 50 mg/kg daily by gavage. The results showed muscle weight, and mTORC1 phosphorylation decreased in TSV compared to the HSV group. mTORC1 phosphorylation was increased in TER compared to TSV, TEV, and TSR. In addition, AMPK phosphorylation was more elevated in HER compared to HSV, HEV, and HSR. LC3BII/I ratio was higher in TSV than HSV group. Tumor volume was increased in all groups, with the lowest increase in TER group. In tumor tissue, mTORC1 phosphorylation was decreased in TER than in TSV, TEV, and TSR groups; AMPK phosphorylation and LC3BII/I ratio were increased in TSV than in TEV, TSR, and TER groups. In conclusion, the synergistic effect of resistance training and resveratrol supplementation is the most effective in reducing tumor volume. These advantages were mostly in line with molecular findings.

Remodeling the tumor immune microenvironment through hydrogel encapsulated G-Rh2 in situ vaccine and systemic immunotherapy

Ginsenoside Rh2 (G-Rh2) is a vital bioactive compound in Traditional Chinese Medicine, celebrated for its strong pharmacological properties, particularly its potent antitumor effects. However, its poor water solubility and limited bioavailability have necessitated the development of a novel drug delivery method. In this study, we utilized an indocyanine green carboxylic acid-hydroxypropyl cellulose-abietic acid-bovine serum albumin hydrogel (ICG-HPC-AA/BSA hydrogel) as a tumor in situ vaccine to enhance the permeability, retention, and tumor-targeted therapeutic efficacy of G-Rh2. We examined the therapeutic impact of a G-Rh2-loaded hydrogel combined with systemic PD-1 antibody treatment in murine models of H22 liver cancer and CT26 colon cancer. Additionally, we explored the immune microenvironment of the tumors influenced by this in situ vaccination strategy.

Engineered PLGA Core-Lipid Shell Hybrid Nanocarriers Improve the Efficacy and Safety of Irinotecan to Combat Colon Cancer.

Poly(lactide-co-glycolide) (PLGA) is a biocompatible and biodegradable copolymer that has gained high acceptance in biomedical applications. In the present study, PLGA (Mw = 13,900) was synthesized by ring-opening polymerization in the presence of a biocompatible zinc-proline initiator through a green route. Irinotecan (Ir) loaded with efficient PLGA core-lipid shell hybrid nanocarriers (lipomers, LPs) were formulated with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino (polyethylene glycol)-2000] (DSPE-PEG-2000), using soya lecithin, by a nanoprecipitation method, and the fabricated LPs were designated as P-DSPE-Ir and P-DSPE-PEG-Ir, respectively. The formulated LPs were further validated for their physicochemical properties and biological potential for colon cancer application. The potential delivery of a poorly water-soluble chemotherapeutic drug (Ir) was studied for the treatment of colon cancer. LPs were successfully prepared, providing controlled size (80-120 nm) and surface charge (∼ -35 mV), and the sustained release properties and cytotoxicity against CT-26 colon cancer cells were studied. The in vivo biodistribution and tumor site retention in CT-26 xenograft tumor-bearing Balb/C mice showed promising results for tumor uptake and retention for a prolonged time period. Unlike P-DSPE-Ir, the P-DSPE-PEG-Ir LP exhibited significant tumor growth delay as compared to untreated and blank formulation-treated groups in CT-26 (subcutaneous tumor model) after 4 treatments of 10 mg irinotecan/kg dose. The biocompatibility and safety of the LPs were confirmed by an acute toxicity study of the optimized formulation. Overall, this proof-of-concept study demonstrates that the PLGA-based LPs improve the efficacy and bioavailability and decrease neutropenia of Ir to combat colon cancer.

Dihydroartemisinin restores the immunogenicity and enhances the anticancer immunosurveillance of cisplatin by activating the PERK/eIF2α pathway

BackgroundImmunosurveillance is pivotal in the effectiveness of anticancer therapies and tumor control. The ineffectiveness of cisplatin in activating the immunosurveillance is attributed to its lack of adjuvanticity resulting from its inability to stimulate endoplasmic reticulum stress. Dihydroartemisinin demonstrates the anti-tumor effects through various mechanisms, including the activation of the endoplasmic reticulum stress. This study aimed to develop a novel strategy to enhance the immunogenicity of dying tumor cells by combining cisplatin with dihydroartemisinin, thereby triggering effective anti-tumor immunosurveillance and improving the efficacy of cisplatin in clinical practice.MethodsLewis lung carcinoma (LLC) and CT26 colon cancer cell lines and subcutaneous tumor models were used in this study. The importance of immunosurveillance was validated in both immunocompetent and immunodeficient mouse models. The ability of dihydroartemisinin and cisplatin therapy to induce immunogenic cell death and tumor growth control in vivo was validated by prophylactic tumor vaccination and therapeutic tumor models. The underlying mechanism was elucidated through the pharmaceutical or genetic intervention of the PERK/eIF2α pathway in vitro and in vivo.ResultsDihydroartemisinin enhanced the generation of reactive oxygen species in cisplatin-treated LLC and CT26 cancer cells. The combination treatment of dihydroartemisinin with cisplatin promoted cell death and ensured an optimal release of damage-associated molecular patterns from dying cancer cells, promoting the phagocytosis of dendritic cells. In the tumor vaccination model, we confirmed that dihydroartemisinin plus cisplatin treatment induced immunogenic cell death. Utilizing immunocompetent and immunodeficient mouse models, we further demonstrated that the combination treatment suppressed the tumor growth of CT26 colon cancer and LLC lung cancer, leading to an improved prognosis through the restoration of cytotoxic T lymphocyte responses and reinstatement of anti-cancer immunosurveillance in vivo. Mechanistically, dihydroartemisinin restored the immunogenicity of cisplatin by activating the adjuvanticity of damage-associated molecular patterns, such as calreticulin exposure, through the PERK/eIF2α pathway. Additionally, the inhibition of eIF2α phosphorylation attenuated the anti-tumor efficiency of C + D in vivo.ConclusionsWe highlighted that dihydroartemisinin acts as an immunogenic cell death rescuer for cisplatin, activating anticancer immunosurveillance in a PERK/eIF2α-dependent manner and offering a strategy to enhance the anti-tumor efficacy of cisplatin in clinical practice.

Exploring the Therapeutic Potential of 5-Fluorouracil-Loaded Calcium Carbonate Nanoparticles Combined with Natural Compound Thymoquinone for Colon Cancer Treatment.

Given the need for novel and effective therapies for colon cancer, this study aimed to investigate the effects of 5-fluorouracil-loaded calcium carbonate nanoparticles (5FU-CaCO3np) combined with thymoquinone (TQ) against colon cancer. A shaking incubator and a high-speed homogenizer were used to prepare the optimal 5FU-CaCO3np, with characterizations of physicochemical properties, in vitro drug release profile, and biocompatibility. In vitro experiments and molecular docking were employed to evaluate the therapeutic potential of the combination for colon cancer treatment. Study results revealed that 5FU-CaCO3np with a size of approximately 130 nm was synthesized using the high-speed homogenizer. Its favorable biocompatibility, pH sensitivity, and sustained release properties facilitated reduced toxic side effects of 5-FU on NIH3T3 normal cells and enhanced inhibitory effects on CT26 colon cancer cells. The combination of 5FU-CaCO3np (1.875 μM) and TQ (30 μM) showed significantly superior anti-colon cancer effects to 5FU-CaCO3np alone in terms of cell proliferation and migration inhibition, cell apoptosis induction, and spheroid growth suppression in CT26 cells (p < 0.05), with strong interactions between the drugs and targets (E-cadherin, Bcl-2, PCNA, and MMP-2). These results provide evidence for 5FU-CaCO3np as a novel regimen against colon cancer. Combining 5FU-CaCO3np and TQ may offer a new perspective for colon cancer therapy.

Extracellular Membrane Vesicles of Escherichia coli Induce Apoptosis of CT26 Colon Carcinoma Cells.

Escherichia coli (E. coli) is commonly utilized as a vehicle for anti-tumor therapy due to its unique tumor-targeting capabilities and ease of engineering modification. To further explore the role of E. coli in tumor treatment, we consider that E. coli outer membrane vesicles (E. coli-OMVs) play a crucial role in the therapeutic process. Firstly, E. coli-OMVs were isolated and partially purified by filtration and ultracentrifugation, and were characterized using techniques such as nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western Blot (WB). The obtained extracellular nanoparticles, containing OMVs, were found to inhibited the growth of CT26 tumor in mice, while the expression of Bax protein was increased and the expression of Bcl-2 protein decreased. In vitro experiments showed that E. coli-OMVs entered CT26 cells and inhibited cell proliferation, invasion and migration. In addition, in the presence of E. coli-OMVs, we observed an increase in apoptosis rate and a decrease in the ratio of Bcl-2/Bax. These data indicate that E. coli-OMVs inhibits the growth of CT26 colon cancer by inducing apoptosis of CT26 cells. These findings propose E. coli-OMVs as a promising therapeutic drug for colorectal cancer (CRC), providing robust support for further research in related fields.

Antibody targeting of anaerobic bacteria warms cold tumors and improves the abscopal effect of radiotherapy

BackgroundThe combination of immune checkpoint inhibitors with radiotherapy can enhance the immunomodulation by RT and reduce the growth of distant unirradiated tumors (abscopal effect); however, the results are still not very satisfactory. Therefore, new treatment options are needed to enhance this effect. Our previous study showed that the combination of Bifidobacterium (Bi) and its specific monoclonal antibody (mAb) could target and alleviate hypoxia at the tumor site and act as a radiosensitizer. In this study, we explored the anti-tumor efficacy of quadruple therapy (Bi + mAb and RT + αPD-1). The current study also aimed to probe into the complex immune mechanisms underlying this phenomenon.MethodsConstructed 4T1 breast and CT26 colon cancer tumor models. A comprehensive picture of the impact of constructed quadruple therapy was provided by tumor volume measurements, survival analysis, PET/CT imaging, immune cell infiltration analysis and cytokine expression levels.ResultsThe abscopal effect was further amplified in the “cold” tumor model and prolonged survival in tumor-bearing mice. Bi can colonized in primary and secondary tumors and direct the mAb to reach the tumor site, activate complement, enhance the ADCC effect and initiate the innate immune response. Then combined with αPD-1 and radiotherapy to stimulate adaptive immune response and synergize with cytokines to expand the immune efficacy and generate effective anti-tumor immune response.ConclusionsBi was used as an artificially implanted anaerobic target to cause a transient “infection” at the tumor, causing the tumor to become locally inflamed and “hot”, and at the same time, mAb was used to target Bi to enhance the local immune effect of the tumor, and then combined with radiotherapy and αPD-1 to amplify the abscopal effect in multiple dimensions. Therefore, the present study provided a new idea for the multipotent immune-activating function of antibody-targeted anaerobic bacteria for the RT treatment of extensively metastasized cancer patients.

Codelivery of methotrexate and silibinin by niosome nanoparticles for enhanced chemotherapy of CT26 colon cancer cells

Colon cancer (CC) is one of the most prevalent cancers in the world, and chemotherapy is widely applied to combat it. However, chemotherapy drugs have severe side effects and emergence of multi drug resistance (MDR) is common. This bottleneck can be overcome by niosome nanocarriers that minimize drug dose/toxicity meanwhile allow co-loading of incompatible drugs for combination therapy. In this research, silibinin (Sil) as a hydrophobic drug was loaded into the lipophilic part, and methotrexate (MTX) into the hydrophilic part of niosome by the thin film hydration (TFH) method to form Nio@MS NPs for CT26 colon cancer therapy in vitro. Our results indicated synthesis of ideal niosome nanoparticles (NPs) with spherical morphology, size of ∼100 nm, and a zeta potential of −10 mV. The IC50 value for Nio@MS was determined ∼2.6 µg ml−1, which was significantly lower than MTX-Sil (∼6.86 µg ml−1), Sil (18.46 µg ml−1 ), and MTX (9.8 µg ml−1 ). Further, Nio@MS significantly reduced cell adhesion density, promoted apoptosis and increased gene expression level of caspase 3 and BAX while promoted significant downregulation of BCL2. In conclusion, the design and application of niosome to co-administer Sil and MTX can increase the drugs cytotoxicity, reduce their dose and improve anti-cancer potential by combating MDR.

Baicalin Prevents Colon Cancer by Suppressing CDKN2A Protein Expression.

To observe the therapeutic effects and underlying mechanism of baicalin against colon cancer. The effects of baicalin on the proliferation and growth of colon cancer cells MC38 and CT26. WT were observed and predicted potential molecular targets of baicalin for colon cancer therapy were studied by network pharmacology. Furthermore, molecular docking and drug affinity responsive target stability (DARTS) analysis were performed to confirm the interaction between potential targets and baicalin. Finally, the mechanisms predicted by in silico analyses were experimentally verified in-vitro and in-vivo. Baicalin significantly inhibited proliferation, invasion, migration, and induced apoptosis in MC38 and CT26 cells (all P<0.01). Additionally, baicalin caused cell cycle arrest at the S phase, while the G0/G1 phase was detected in the tiny portion of the cells. Subsequent network pharmacology analysis identified 6 therapeutic targets associated with baicalin, which potentially affect various pathways including 39 biological processes and 99 signaling pathways. In addition, molecular docking and DARTS predicted the potential binding of baicalin with cyclin dependent kinase inhibitor 2A (CDKN2A), protein kinase B (AKT), caspase 3, and mitogen-activated protein kinase (MAPK). In vitro, the expressions of CDKN2A, MAPK, and p-AKT were suppressed by baicalin in MC38 and CT26 cells. In vivo, baicalin significantly reduced the tumor size and weight (all P<0.01) in the colon cancer mouse model via inactivating p-AKT, CDKN2A, cyclin dependent kinase 4, cyclin dependent kinase 2, interleukin-1, tumor necrosis factor α, and activating caspase 3 and mouse double minute 2 homolog signaling (all P<0.05). Baicalin suppressed the CDKN2A protein level to prevent colon cancer and could be used as a therapeutic target for colon cancer.

Non-viral-mediated gene transfer of OX40 ligand for tumor immunotherapy.

Immune checkpoint blockade (ICB) is rapidly becoming a standard of care in the treatment of many cancer types. However, the subset of patients who respond to this type of therapy is limited. Another way to promote antitumoral immunity is the use of immunostimulatory molecules, such as cytokines or T cell co-stimulators. The systemic administration of immunotherapeutics leads to significant immune-related adverse events (irAEs), therefore, the localized antitumoral action is needed. One way to achieve this is intratumoral non-viral gene-immune therapy, which allows for prolonged and localized gene expression, and multiple drug administration. In this study, we combined the previously described non-viral gene delivery system, PEG-PEI-TAT copolymer, PPT, with murine OX40L-encoding plasmid DNA. The resulting OX40L/PPT nanoparticles were characterized via gel mobility assay, dynamic light scattering analysis and in vitro transfection efficiency evaluation. The antitumoral efficacy of intratumorally (i.t.) administered nanoparticles was estimated using subcutaneously (s.c.) implanted CT26 (colon cancer), B16F0 (melanoma) and 4T1 (breast cancer) tumor models. The dynamics of stromal immune cell populations was analyzed using flow cytometry. Weight loss and cachexia were used as irAE indicators. The effect of combination of i.t. OX40L/PPT with intraperitoneal PD-1 ICB was estimated in s.c. CT26 tumor model. The obtained OX40L/PPT nanoparticles had properties applicable for cell transfection and provided OX40L protein expression in vitro in all three investigated cancer models. We observed that OX40L/PPT treatment successfully inhibited tumor growth in B16F0 and CT26 tumor models and showed a tendency to inhibit 4T1 tumor growth. In B16F0 tumor model, OX40L/PPT treatment led to the increase in antitumoral effector NK and T killer cells and to the decrease in pro-tumoral myeloid cells populations within tumor stroma. No irAE signs were observed in all 3 tumor models, which indicates good treatment tolerability in mice. Combining OX40L/PPT with PD-1 ICB significantly improved treatment efficacy in the CT26 subcutaneous colon cancer model, providing protective immunity against CT26 colon cancer cells. Overall, the anti-tumor efficacy observed with OX40L non-viral gene therapy, whether administered alone or in combination with ICB, highlights its potential to revolutionize cancer gene therapy, thus paving the way for unprecedented advancements in the cancer therapy field.

Resiquimod-loaded cationic liposomes cure mice with peritoneal carcinomatosis and induce specific anti-tumor immunity

Peritoneal carcinomatosis (PC) is characterized by a high recurrence rate and mortality following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC), primarily due to incomplete cancer elimination. To enhance the standard of care for PC, we developed two cationic liposomal formulations aimed at localizing a toll-like receptor agonist, resiquimod (R848), in the peritoneal cavity to activate the immune system locally to specifically eradicate residual tumor cells. These formulations effectively extended R848 retention in the peritoneum by >10-fold, resulting in up to a 2-fold increase in interferon α (IFN-α) induction in the peritoneal fluid, without increasing the plasma levels. In a CT26 colon cancer model with peritoneal metastases, these liposomal R848 formulations, when combined with oxaliplatin (OXA)—an agent used in HIPEC that induces immunogenic cell death—increased tumor infiltration of effector immune cells, including DCs, CD4, and CD8 T cells. This led to the complete elimination of PC in 60–70% of the mice, while the control mice reached humane endpoints by 30 days. The cured mice developed specific antitumor immunity, as re-challenging them with the same tumor cells did not result in tumor establishment. However, inoculation with a different tumor line led to tumor development. Additionally, exposing CT26 tumor antigens to the splenocytes isolated from the cured mice induced the expansion of CD4 and CD8 T cells and the release of IFN-γ, demonstrating long-term immune memory to the specific tumor. The anti-tumor efficacy of these liposomal R848 formulations was mediated via CD8 T cells with different levels of involvement of CD4 and B cells, and the combination with an anti-PD-1 antibody achieved a cure rate of 90%.