丙戊酸协同顺铂抑制乳腺癌和结直肠癌细胞生长

摘要 目的：探究丙戊酸（Valproic acid, VPA）协同顺铂抑制乳腺癌和结直肠癌细胞增殖。方法：首先使用Western blot 检测 VPA 对Acetyl-Histone H3蛋白水平的影响,使用Cell Counting Kit-8（CCK-8）法检测 VPA 对乳腺癌和结直肠癌细胞的细胞活力的影响。其次单药顺铂、VPA 和联合用药处理乳腺癌细胞 MDA-MB-231 和结直肠癌细胞 HCT-15,使用 IncuCyte 动态检测细胞生长过程和生长终点。结果：发现VPA 可抑制组蛋白去乙酰化酶的功能,升高Acetyl-Histone H3的蛋白水平,VPA 可抑制乳腺癌细胞和结直肠癌细胞增殖,且对 VPA 的药物敏感性相似;顺铂和 VPA 连用后可显著抑制乳腺癌和结直肠癌细胞增殖和活力。结论：本文发现 VPA 抑制组蛋白去乙酰化酶发挥抑制乳腺癌和结直肠癌细胞生长的新机制,并可以与顺铂连用提高抗肿瘤效果和药物敏感性,为同时患有癫痫和肿瘤的人群提供新的治疗思路。     

1,2,3,4,6-Penta-O-galloyl-β-d-glucose suppresses colon cancer through induction of tumor suppressor

Colon cancer is the third most common malignancy in both sexes of Korea. Here, we investigated anti-colorectal cancer effects of 1,2,3,4,6-penta-O-galloyl-β-d-glucose (PGG), a gallotannin from Galla rhois, and its possible mechanisms. PGG induced cytotoxicity and decreased proliferation of colon cancer cells without affecting normal colon fibroblasts. PGG inhibited clonogenic ability and induced apoptosis in cancer cells. One of the underlying mechanisms of the anti-cancer effect exerted by PGG, was owing to the induction p53 expression, a well-known tumor suppressor, and increased in P21, the representative target gene of p53. PGG affected cell-cycle- or apoptosis-related proteins such as cyclin E, CDK2, and Bcl-2, cleaved caspase-3. Also, PGG induced caspase-3/7 activity. These data suggest that PGG exerts anti-colorectal cancer effects.     

ω-3 Polyunsaturated fatty acids and their cytochrome P450-derived metabolites suppress colorectal tumor development in mice

Many studies have shown that dietary intake of ω-3 polyunsaturated fatty acids (PUFAs) reduces the risks of colorectal cancer; however, the underlying mechanisms are not well understood. Here we used a LC–MS/MS-based lipidomics to explore the role of eicosanoid signaling in the anti-colorectal cancer effects of ω-3 PUFAs. Our results showed that dietary feeding of ω-3 PUFAs-rich diets suppressed growth of MC38 colorectal tumor, and modulated profiles of fatty acids and eicosanoid metabolites in C57BL/6 mice. Notably, we found that dietary feeding of ω-3 PUFAs significantly increased levels of epoxydocosapentaenoic acids (EDPs, metabolites of ω-3 PUFA produced by cytochrome P450 enzymes) in plasma and tumor tissue of the treated mice. We further showed that systematic treatment with EDPs (dose=0.5 mg/kg per day) suppressed MC38 tumor growth in mice, with reduced expressions of pro-oncogenic genes such as C-myc, Axin2, and C-jun in tumor tissues. Together, these results support that formation of EDPs might contribute to the anti-colorectal cancer effects of ω-3 PUFAs.     

Antitumor and immunostimulating effects of Anoectochilus formosanus Hayata.

The water extract of Anoectochilus formosanus Hayata showed a potent tumor inhibitory activity in BALB/c mice after subcutaneous transplantation of CT-26 murine colon cancer cells. The tumor-inhibition ratios of mice pre-administered with A. formosanus for 2 days before tumor transplantation, and treated further for 12 consecutive days, were 55.4% and 58.9% at the oral dose of 50 and 10 mg/mouse per day, respectively. Even for the tumor-bearing mice, after oral administration of the water extract of A. formosanus for 12 consecutive days, the tumor inhibition ratios were still 23.8% and 40.5% at doses of 50 and 10 mg/mouse, respectively. Because the low-concentration water extract of A. formosanus does not show direct cytotoxicity in CT-26 tumor cells, we observed further that oral administration of the water extract of A. formosanus may activate murine immune responses, such as stimulating the proliferation of lymphoid tissues and activating the phagocytosis of peritoneal macrophages against Staphylococcus aureus. This study suggests that the antitumor activity of A. formosanus may be associated with its potent immunostimulating effect. It is worth further analyzing the immunomodulating component purified from A. formosanus, and evaluating its potential value for the treatment of human cancers.     

Convallatoxin promotes apoptosis and inhibits proliferation and angiogenesis through crosstalk between JAK2/STAT3 (T705) and mTOR/STAT3 (S727) signaling pathways in colorectal cancer

BackgroundAberrant activation of STAT3 is frequently encountered and promotes survival, cellular proliferation, migration, invasion and angiogenesis in tumor cell. Convallatoxin, triterpenoid ingredient, exhibits anticancer pharmacological properties.PurposeIn this work, we investigated the anticancer potential of convallatoxin and explored whether convallatoxin mediates its effect through interference with the STAT3 activation in colorectal cancer cells.MethodsIn vitro, the underlying mechanisms of convallatoxin at inhibiting STAT3 activation were investigated by homology modeling and molecular docking, luciferase reporter assay, MTT assay, RT-PCR, Western blotting and immunofluorescence assays. Changes in cellular proliferation, apoptosis, migration, invasion and angiogenesis were analyzed by EdU labeling assay, colony formation assay, flow cytometry assay, wound-healing assay, matrigel transwell invasion assay and tube formation assays. And in vivo, antitumor activity of convallatoxin was assessed in a murine xenograft model of HCT116 cells.ResultsConvallatoxin decreased the viability of colorectal cancer lines. Moreover, convallatoxin reduced the P-STAT3 (T705) via the JAK1, JAK2, and Src pathways and inhibited serine-727 phosphorylation of STAT3 via the PI3K-AKT-mTOR-STAT3 pathways in colorectal cancer cells. Interestingly, we discovered the crosstalk between mTOR and JAK2 in mTOR/STAT3 and JAK/STAT3 pathways, which collaboratively regulated STAT3 activation and convallatoxin play a role in it. Convallatoxin also downregulated the expression of target genes involved cell survival (e.g., Survivin, Bcl-xl, Bcl-2), proliferation (e.g., Cyclin D1), metastasis (e.g., MMP-9), and angiogenesis (e.g., VEGF). Indeed, we found that convallatoxin inhibited tube formation, migration, and invasion of endothelial cells, and inhibited the proliferation. Finally, in vivo observations were confirmed by showing antitumor activity of convallatoxin in a murine xenograft model.ConclusionThe result of the current study show that convallatoxin promotes apoptosis and inhibits proliferation and angiogenesis through crosstalk between JAK2/STAT3 (T705) and mTOR/STAT3 (S727) signaling pathways in colorectal cancer cells and indicate that convallatoxin could be a valuable candidate for the development of colorectal cancer therapeutic.     

Britannin stabilizes T cell activity and inhibits proliferation and angiogenesis by targeting PD-L1 via abrogation of the crosstalk between Myc and HIF-1α in cancer

BackgroundProgrammed cell death-ligand 1 (PD-L1) is overexpressed in tumor cells, which causes tumor cells to escape T cell killing, and promotes tumor cell survival, cell proliferation, migration, invasion, and angiogenesis. Britannin is a natural product with anticancer pharmacological effects.PurposeIn this work, we studied the anticancer potential of britannin and explored whether britannin mediated its effect by inhibiting the expression of PD-L1 in tumor cells.MethodsIn vitro, the mechanisms underlying the inhibition of PD-L1 expression by britannin were investigated by MTT assay, homology modeling and molecular docking, RT-PCR, western blotting, co-immunoprecipitation, and immunofluorescence. The changes in tumor killing activity, cell proliferation, cell cycle, migration, invasion, and angiogenesis were analyzed by T cell killing assays, EdU labeling, colony formation, flow cytometry, wound healing, matrigel transwell invasion, and tube formation, respectively. In vivo, the antitumor activity of britannin was evaluated in the HCT116 cell xenograft model.ResultsBritannin reduced the expression of PD-L1 in tumor cells by inhibiting the synthesis of the PD-L1 protein but did not affect the degradation of the PD-L1 protein. Britannin also inhibited HIF-1α expression through the mTOR/P70S6K/4EBP1 pathway and Myc activation through the Ras/RAF/MEK/ERK pathway. Mechanistically, britannin inhibited the expression of PD-L1 by blocking the interaction between HIF-1α and Myc. In addition, britannin could enhance the activity of cytotoxic T lymphocytes and inhibit tumor cell proliferation and angiogenesis by inhibiting PD-L1. Finally, in vivo observations were confirmed by demonstrating the antitumor activity of britannin in a murine xenograft model.ConclusionBritannin inhibits the expression of PD-L1 by blocking the interaction between HIF-1α and Myc. Moreover, britannin stabilizes T cell activity and inhibits proliferation and angiogenesis by inhibiting PD-L1 in cancer. The current work highlights the anti-tumor effect of britannin, providing insights into the development of cancer therapeutics via PD-L1 inhibition.     

Anti-cancer effect of marchantin C via inducing lung cancer cellular senescence associated with less secretory phenotype

BackgroundLung cancer is the leading cause of global cancer deaths. Current chemotherapeutic agents for lung cancer treatment are generally accompanied with severe side effects. Here, we report that marchantin C (Mar-C), a potential natural compound with little chemotherapeutic toxicity, exerts a well anti-tumor effect against lung cancer via inducing cellular senescence.MethodsThe antitumor activity of Mar-C was evaluated by MTT and colony formation in vitro cytotoxicity assays, and xenograft and homograft in vivo model. Antitumor mechanisms of Mar-C were investigated through SA-β-gal staining, Q-PCR, immunoblotting, immunofluorescence, protein array and siRNA knocking-down analysis.ResultsMar-C selectively induces senescence of lung cancer cells with limited cytotoxicity on normal or non-neoplastic cells. Mar-C-induced senescence was associated with the elevation of ROS and activation of DNA-damage, and largely dependent of prolonged p21^CIP1 accumulation. The senescence-associated secretory phenotype (SASP) induced by Mar-C was distinct from doxorubicin-induced. Furthermore, Mar-C exhibited an inhibitory activity on tumor growth with little toxicity in animal studies, and significantly prolonged the survival time of tumor-bearing mice than that of doxorubicin or vehicle treatments.ConclusionMar-C selectively inhibited tumor growth via the induction of cancer cell senescence and had little chemotherapeutic toxicity, suggesting the potential of Mar-C as a promising anticancer agent.General significanceThis study provided evidence to identify a novelty of Mar-C that exerted antitumor activity on lung cancer through induction of senescence with limited toxicity.     

Enhanced immunostimulatory and antitumor activity of different derivatives of κ-carrageenan oligosaccharides from <Emphasis Type="Italic">Kappaphycus striatum</Emphasis>

Chemical modification of carbohydrates can lead to differences in their biological activities. We previously showed that κ-carrageenan oligosaccharides from Kappaphycus striatum have antitumor and immunomodulation effects on S180-bearing mice. In this study, we tested the hypothesis that different chemical modifications of carrageenan oligosaccharides enhance their activities. The mice inoculated with S180 cell suspension were treated p.o. with carrageenan oligosaccharides and their sulfated, acetylated, and phosphorylated derivatives (50, 100, and 200 μg g⁻¹) for 14 days. Transplantable tumor inhibition rate and macrophage phagocytosis, quantitative hemolysis of sheep red blood cells, lymphocyte proliferation, the activity of natural killer cells, production of interleukin-2, and tumor necrosis factor-α were also analyzed. As expected, treatment with different κ-carrageenan oligosaccharides derivatives resulted in an increase in tumor inhibition rate and macrophage phagocytosis and cellular immunity, especially on spleen lymphocyte proliferation. The sulfated derivative at the dose 200 μg g⁻¹ per day showed the highest antitumor activity with the 54.12% tumor weight inhibition and elicited an increase in nature killer cells activity up to 76.1% on S180-bearing mice, which were both significantly higher than the unmodified oligosaccharides. It suggested that chemical modification (especially sulfation) of carrageenan oligosaccharides can enhance their antitumor effect and boost their antitumor immunity.     

Antitumor activity of sulfated extracellular polysaccharides of Ganoderma lucidum from the submerged fermentation broth

Water-soluble extracellular polysaccharides are known to possess weak or no in vitro antitumor activity. In this experiment, a mixture of extracellular Ganoderma lucidum polysaccharides (GLP) from the submerged fermentation broth was sulfated and studied on their antitumor activity. The sulfated GLP performed significant inhibition on the proliferation of assayed carcinoma cells in a dose-dependent manner, and present a degree of substitution-dependent suppressing to HepG2 cells. Meanwhile, the sulfated GLP presented remarkable but not dose-dependent inhibition on Heps hepatona in mice. With same degree of substitution, the sulfation protocol with aminosulfonic acid-pyridine yielded GLP sulfates with higher activity on HepG2 cells. In comparison, the native GLP showed no or little antitumor activity on the assayed cell lines but remarkable inhibition on suppressing the proliferation of rat Heps. The highest in vivo inhibition rate of 55.5% provided by sulfated GLP was observed on suppressing the proliferation of rat Heps.     

Antitumor Efficacy of the Dual PI3K/mTOR Inhibitor PF-04691502 in a Human Xenograft Tumor Model Derived from Colorectal Cancer Stem Cells Harboring a PIK3CA Mutation

PIK3CA (phosphoinositide-3-kinase, catalytic, alpha polypeptide) mutations can help predict the antitumor activity of phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway inhibitors in both preclinical and clinical settings. In light of the recent discovery of tumor-initiating cancer stem cells (CSCs) in various tumor types, we developed an in vitro CSC model from xenograft tumors established in mice from a colorectal cancer patient tumor in which the CD133+/EpCAM+ population represented tumor-initiating cells. CD133+/EpCAM+ CSCs were enriched under stem cell culture conditions and formed 3-dimensional tumor spheroids. Tumor spheroid cells exhibited CSC properties, including the capability for differentiation and self-renewal, higher tumorigenic potential and chemo-resistance. Genetic analysis using an OncoCarta™ panel revealed a PIK3CA (H1047R) mutation in these cells. Using a dual PI3K/mTOR inhibitor, PF-04691502, we then showed that blockage of the PI3K/mTOR pathway inhibited the in vitro proliferation of CSCs and in vivo xenograft tumor growth with manageable toxicity. Tumor growth inhibition in mice was accompanied by a significant reduction of phosphorylated Akt (pAKT) (S473), a well-established surrogate biomarker of PI3K/mTOR signaling pathway inhibition. Collectively, our data suggest that PF-04691502 exhibits potent anticancer activity in colorectal cancer by targeting both PIK3CA (H1047R) mutant CSCs and their derivatives. These results may assist in the clinical development of PF-04691502 for the treatment of a subpopulation of colorectal cancer patients with poor outcomes.     

Atractylenolide I inhibits colorectal cancer cell proliferation by affecting metabolism and stemness via AKT/mTOR signaling

BackgroundAtractylenolide I (ATL-1) is a natural herbal compound used in traditional Chinese medicine that has exhibited anti-cancer properties. The anti-tumorigenic activity of ATL-1 against colorectal cancer (CRC) and the underlying signaling pathways involved in its mechanisms are examined here.HypothesisATL-1 exerts therapeutic effect against CRC by disrupting glucose metabolism and cancer stem cell maintenance via AKT/mTOR pathway regulation.Study designIn vitro studies were performed in COLO205 and HCT116 CRC cell lines and in vivo studies were conducted in a mouse xenograft model of CRC tumor.MethodsCRC cells were treated with ATL-1 at various concentrations, with or without inhibitors of AKT or mTOR. Cell proliferation, apoptosis, invasion, stemness maintenance, glucose metabolism, and AKT/mTOR signaling were evaluated. CRC tumor-xenografted mice were treated with an AKT inhibitor and/or ATL-1, and glucose metabolism and stemness maintenance were examined in tumor tissues.ResultsATL-1 significantly inhibited the invasion of CRC cells by inducing their apoptosis, possibly via the excessive production of reactive oxygen species. Glucose metabolism (Warburg effect) was also altered and stem-like traits were suppressed by ATL-1. In addition, ATL-1 effectively acted as an inhibitor or AKT/mTOR by downregulating the phosphorylation of proteins related to the AKT/mTOR pathway. In vivo studies showed that tumor weight and volume were reduced by ATL-1 and that aerobic glycolysis, stemness maintenance, and AKT/mTOR activation were impaired by ATL-1 in colorectal tumors.ConclusionsATL-1 acts as an effective agent to suppress colorectal tumor progression, mainly by inhibiting CRC cell proliferation through altering apoptosis, glucose metabolism, and stem-like behavior. These processes were mediated by the AKT/mTOR signaling pathway both in vitro and in vivo. ATL-1 may be a potential agent to be used in molecular-targeted strategies for cancer treatment.     

Benzochalcones bearing pyrazoline moieties show anti-colorectal cancer activities and selective inhibitory effects on aurora kinases

Colorectal cancer is the third and fourth leading cause of cancer in males and females, respectively. Flavonoids, including chalcones, are secondary metabolites in plants that exhibit diverse biological activities, including antibacterial, antimalarial, and antitumor activities. In order to find potent and novel chemotherapy drugs for colorectal cancer, a series of benzochalcone derivatives, in which an α,β-unsaturated carbonyl group was replaced with a pyrazoline, was designed and synthesized. A clonogenic survival assay was performed with each derivative to evaluate antitumor activity. 1-(5-(2,4-Dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl)naphthalen-2-ol (derivative 7) had the most potent inhibitory effect on the long-term clonogenicity of HCT116 human colorectal cancer cells (IC₅₀ = 2.4 μM). The results of Western blot and flow cytometric analyses suggested that derivative 7 could inhibit the proliferation of colorectal cancer cells through inhibition of cell cycle progression and induction of apoptosis. To elucidate its molecular mechanism, in vitro kinase binding assays were carried out, which demonstrated that derivative 7 inhibited aurora kinases A and B selectively. The binding modes between the compound and aurora kinases were interpreted using in silico docking experiments to explain the selective inhibitory effects on aurora kinases A and B. These findings will facilitate the design of potent novel benzochalcones as anticancer agents.     

Hsa_circ_0136666 activates Treg-mediated immune escape of colorectal cancer via miR-497/PD-L1 pathway

PurposeIn the rankings of cancer mortality and incidence worldwide, colorectal cancer ranks fourth and the third, respectively. Circular RNA hsa_circ_0136666 (hsa_circ_0136666) is reported to participate in the growth of colorectal cancer. However, the mechanism by which hsa_circ_0136666 regulates the tumorigenesis of colorectal cancer needs to be further explored. In this study, we report here the role of hsa_circ_0136666 in the aberrant activation of Treg cells and immune evasion of tumor cells, providing a new strategy for the treatment of colorectal cancer.MethodsWestern blotting assay and qRT-PCR assay were used to determine protein and mRNA expression levels. Dual-luciferase reporter assay was used to evaluate the targeted regulatory relationship. RNA immunoprecipitation was used to detect RNA binding. Colony formation assay was utilized to measure the cell proliferation. Flow cytometry was used to assess cell apoptosis. Xenograft model was setup to evaluate tumor growth.ResultsThe results showed that hsa_circ_0136666 and PD-L1 was increased in colorectal cancer cells while miR-497 was decreased in colorectal cancer cells when compared with normal colon epithelial cell line. Hsa_circ_0136666 was demonstrated to directly target miR-497, which also regulated PD-L1 by binding to its 3′UTR. Further mechanistic studies identified that hsa_circ_0136666 controlled cell proliferation and apoptosis via targeting miR-497 and regulating PD-L1 expression. Of note, hsa_circ_0136666 stimulated Treg cells mediated by miR-497/PD-L1 axis and its downstream signal pathway in Treg cells. Finally, hsa_circ_0136666 was found to accelerate the tumor growth in vivo.ConclusionsOur findings demonstrated that hsa_circ_0136666 promoted the expression of PD-L1 by inhibiting miR-497 level in colorectal cancer, thus inducing the activation of Treg cells and leading to the immune escape of tumor, providing a novel mechanistic insight into the pathogenesis of colorectal cancer.     

ATG4B promotes colorectal cancer growth independent of autophagic flux

Autophagy is reported to suppress tumor proliferation, whereas deficiency of autophagy is associated with tumorigenesis. ATG4B is a deubiquitin-like protease that plays dual roles in the core machinery of autophagy; however, little is known about the role of ATG4B on autophagy and proliferation in tumor cells. In this study, we found that ATG4B knockdown induced autophagic flux and reduced CCND1 expression to inhibit G₁/S phase transition of cell cycle in colorectal cancer cell lines, indicating functional dominance of ATG4B on autophagy inhibition and tumor proliferation in cancer cells. Interestingly, based on the genetic and pharmacological ablation of autophagy, the growth arrest induced by silencing ATG4B was independent of autophagic flux. Moreover, dephosphorylation of MTOR was involved in reduced CCND1 expression and G₁/S phase transition in both cells and xenograft tumors with depletion of ATG4B. Furthermore, ATG4B expression was significantly increased in tumor cells of colorectal cancer patients compared with adjacent normal cells. The elevated expression of ATG4B was highly correlated with CCND1 expression, consistently supporting the notion that ATG4B might contribute to MTOR-CCND1 signaling for G₁/S phase transition in colorectal cancer cells. Thus, we report that ATG4B independently plays a role as a positive regulator on tumor proliferation and a negative regulator on autophagy in colorectal cancer cells. These results suggest that ATG4B is a potential biomarker and drug target for cancer therapy.     

Sulfation of (1→3)-β-d-glucan from the fruiting bodies of Russula virescens and antitumor activities of the modifiers

A water-insoluble (1→3)-β-d-glucan isolated from the fresh fruiting bodies of Russula virescens was sulfated using sulfur trioxide-pyridine complex as reagent in dimethyl sulfoxide. Depending on the reaction conditions, the products showed different degrees of sulfation (DS) ranging from 0.17 to 1.17 and different weight average molecular weights (M_ws) ranging from 2.5 × 10⁴ to 1.2 × 10⁵ Da. Moreover, the antitumor activities of the five sulfated derivatives against Sarcoma 180 tumor cell were tested both in vitro and in vivo. The results indicated that the native (1→3)-β-d-glucan did not show antitumor activity, while the sulfated derivatives exhibited enhanced antitumor activities. This study demonstrated that DS and M_w could influence the antitumor activities of the sulfated derivatives.     

Empty liposomes induce antitumoral effects associated with macrophage responses distinct from those of the TLR1/2 agonist Pam3CSK4 (BLP)

Liposomes are frequently used in cancer therapy to encapsulate and apply anticancer drugs. Here, we show that a systemic treatment of mice bearing skin tumors with empty phosphatidylcholine liposomes (PCL) resulted in inhibition of tumor growth, which was similar to that observed with the synthetic bacterial lipoprotein and TLR1/2 agonist Pam₃CSK₄ (BLP). Both compounds led to a substantial decrease of macrophages in spleen and in the tumor-bearing skin. Furthermore, both treatments induced the expression of typical macrophage markers in the tumor-bearing tissue. As expected, BLP induced the expression of the M1 marker genes Cxcl10 and iNOS, whereas PCL, besides inducing iNOS, also increased the M2 marker genes Arg1 and Trem2. In vitro experiments demonstrated that neither PCL nor BLP influenced proliferation or survival of tumor cells, whereas both compounds inhibited proliferation and survival and increased the migratory capacity of bone marrow-derived macrophages (BMDM). However, in contrast to BLP, PCL did not activate cytokine secretion and induced a different BMDM phenotype. Together, the data suggest that similar to BLP, PCL induce an antitumor response by influencing the tumor microenvironment, in particular by functional alterations of macrophages, however, in a distinct manner from those induced by BLP.     

Anti-tumor effect of aquaporin 3 monoclonal antibody on syngeneic mouse tumor model

Aquaporin-3 (AQP3), a water channel protein, has been found to be involved in cancer progression via water and small molecule transport function. However, drug development targeting AQP3 has not yet begun.Here, we showed that a recently established anti-AQP3 monoclonal antibody (mAb) suppresses tumor growth in allograft mouse colorectal tumor models produced using CT26 or MC38 cancer cells. Administration of the anti-AQP3 mAb to BALB/c mice with transplanted CT26 cells increased the M1/M2 ratio of tumor-associated macrophages (TAM) and improved the mitochondrial function of T cells in the tumor microenvironment (TME). Administration of anti-AQP3 mAb also restored the TAM-induced decrease in T cell proliferation. Macrophage depletion in wild-type mice counteracted the antitumor effect of anti-AQP3 mAb in the mouse tumor model, suggesting that one of the primary targets of anti-AQP3 mAb is macrophages. In in vitro studies using mice bone marrow monocytes and human monocyte THP-1 cells, anti-AQP3 mAb attenuated carcinoma cell-mediated polarization of monocytes into M2-like TAMs.These data suggest that anti-AQP3 mAb suppresses tumor growth by attenuating immunosuppressive M2-like TAMs, which in turn maintains the antitumor function of T cells in the TME. Thus, the anti-AQP3 mAb is a potential cancer therapy that functions by targeting TAMs.     

Gansui-Banxia Decoction extraction inhibits MDSCs accumulation via AKT /STAT3/ERK signaling pathways to regulate antitumor immunity in C57bl/6 mice

BackgroundGansui-Banxia Decoction (GSBXD) is a classic formula of traditional Chinese medical (TCM) sage Zhang Zhongjing to treat stagnation of evil heat and obstruction of qi. At present GSBXD is wildly used to treat cancerous ascites, pleural effusion, peritoneal effusion, pericardial effusion, cranial cavity effusion and several types of cancers, such as hepatocellular carcinoma (HCC) and esophageal cancer. Myeloid-derived suppressor cells (MDSCs) are a kind of immature and heterogeneous cells which can suppress lymphocytes activation by forming a suppressive environment. MDSCs accumulation in peripheral blood and tumors are closely related to the cancer stage and low survival rate of clinical patients. The antitumor immune effect of GSBXD has not received widespread attention.PurposeTo investigate the effects of GSBXD on MDSCs accumulation and the mediators including AKT/STAT3/ERK signaling pathways.MethodsThe chemical components of GSBXD were analyzed by UHPLC-MS, and the putative pathways of GSBXD based on Network pharmacology were predicted. Mice were vaccinated with Hepatoma 22 (H22) to establish tumor growth model, which were then administrated with GSBXD ethanol extraction (0.49 mg/kg/day, 1.75 mg/kg/day), sorafenib (60 mg/kg) or saline for 14 days. The cell morphology was evaluated by hematoxylin and eosin (H&E) staining, and immunity cells were determined through flowcytometry analysis. The levels of cytokines production in blood were evaluated by using ELISA kits. STAT3, ERK and AKT/mTOR signaling transduction associated proteins were determined by Western blot.ResultsGSBXD could inhibit tumor growth and splenomegaly in H22 tumor model mice. Importantly, GSBXD reduced MDSCs accumulation and differentiation, and inhibited proliferation of F4/80⁺ CD11b⁺ macrophages and apoptosis of T cells and B cells, and increased the percentage of CD 3⁻ NK1.1⁺ NK cells. To better understand the active component of GSBXD, the ethanol-extraction powdered GSBXD was prepared and analyzed by UHPLC-MS. Combined with these main chemical compounds, we predicted that the anti-tumor effect of GSBXD mainly mediated PI3K-AKT and RAS-MAPK signal pathways based on Network Pharmacology. Western blot analysis of tumor tissues and MDSCs cells demonstrated that phosphorylation of AKT, ERK and STAT3 were significantly reduced, specially the activation of ERK. The levels of IL-1β and IFN-γ were significantly decreased by ELISA analysis.ConclusionGSBXD exhibited antitumor immune activity by reducing the accumulation of MDSCs in vivo, which is possible via down-regulation of AKT/STAT3/ERK signaling pathway and suppression of IL-1β and IFN-γ.     

Identification of the sAPRIL Binding Peptide and Its Growth Inhibition Effects in the Colorectal Cancer Cells

Background

A proliferation-inducing ligand (APRIL) is a member of the tumor necrosis factor (TNF) super family. It binds to its specific receptors and is involved in multiple processes during tumorigenesis and tumor cells proliferation. High levels of APRIL expression are closely correlated to the growth, metastasis, and 5-FU drug resistance of colorectal cancer. The aim of this study was to identify a specific APRIL binding peptide (BP) able to block APRIL activity that could be used as a potential treatment for colorectal cancer.

Methods

A phage display library was used to identify peptides that bound selectively to soluble recombinant human APRIL (sAPRIL). The peptides with the highest binding affinity for sAPRIL were identified using ELISA. The effects of sAPRIL-BP on cell proliferation and cell cycle/apoptosis in vitro were evaluated using the CCK-8 assay and flow cytometry, respectively. An in vivo mouse model of colorectal cancer was used to determine the anti-tumor efficacy of the sAPRIL-BP.

Results

Three candidate peptides were characterized from eight phage clones with high binding affinity for sAPRIL. The peptide with the highest affinity was selected for further characterization. The identified sAPRIL-BP suppressed tumor cell proliferation and cell cycle progression in LOVO cells in a dose-dependent manner. In vivo in a mouse colorectal challenge model, the sAPRIL-BP reduced the growth of tumor xenografts in nude mice by inhibiting proliferation and inducing apoptosis intratumorally. Moreover, in an in vivo metastasis model, sAPRIL-BP reduced liver metastasis of colorectal cancer cells.

Conclusions

sAPRIL-BP significantly suppressed tumor growth in vitro and in vivo and might be a candidate for treating colorectal cancers that express high levels of APRIL.     

Gomisin A ameliorates metastatic melanoma by inhibiting AMPK and ERK/JNK-mediated cell survival and metastatic phenotypes

BackgroundGomisin A (G.A), a lignan compound extracted from the fruits of Schisandra chinensis, is known to exert anti-tumor effects on hepatocarcinoma and colorectal cancer cells. Suppression of proliferation and metastatic abilities of cancer cells are some effective cancer treatment methods.PurposeThe objective of this study is to investigate the effects of G.A on metastatic melanoma, and the mechanism by which it affects metastatic melanoma.Study designThe anti-proliferative and anti-metastatic effects of G.A were observed in in vitro and in vivo.MethodsWST assay and flow cytometry were conducted to investigate the effect of G.A on proliferation, cell cycle arrest, and apoptosis in metastatic melanoma cell lines. Migration and invasion abilities of G.A-treated melanoma cells were observed by wound healing and invasion assays.ResultsG.A (25–100 μM) decreased the viability of melanoma cells by inducing cell cycle arrest and apoptosis. These anti-proliferative effects of G.A were found to be mediated by AMPK, ERK, and JNK activation. G.A (5–20 μM) decreased the migration and invasion of melanoma cells by suppressing epithelial-mesenchymal transition (EMT). Consequently, G.A (2–50 mg/kg) inhibited lung metastasis by suppressing EMT and inducing cell cycle arrest and apoptosis in melanoma cells.ConclusionThese results conclude that G.A has the potential to reduce metastatic melanoma through its anti-proliferative and anti-metastatic effects.