Adhesive anastomosis for organ transplantation.

The recent development of tough tissue adhesives has stimulated intense interests among material scientists and medical doctors. However, these adhesives have seldom been tested in clinically demanding surgeries. Here we demonstrate adhesive anastomosis in organ transplantation. Anastomosis is commonly conducted by dense sutures and takes a long time, during which all the vessels are occluded. Prolonged occlusion may damage organs and even cause death. We formulate a tough, biocompatible, bioabsorbable adhesive that can sustain tissue tension and pressurized flow. We expose the endothelial surface of vessels onto a gasket, press two endothelial surfaces to the adhesive using a pair of magnetic rings, and reopen the bloodstream immediately. The time for adhesive anastomosis is shortened compared to the time for sutured anastomosis. We have achieved adhesive anastomosis of a great vein in transplanting the liver of a pig. After the surgery, the adhesive is absorbed, the vein heals, and the pig lives for over one month.

SRY is a Key Mediator of Sexual Dimorphism in Hepatic Ischemia/Reperfusion Injury.

OBJECTIVES: To identify the role and mechanism of a male specific gene, SRY, in I/R-induced hepatic injury. BACKGROUND: Males are more vulnerable to I/R injury than females. However, the mechanism of these sex-based differences remains poorly defined. METHODS: Clinicopathologic data of patients who underwent hepatic resection were identified from an international multi-institutional database. Liver specific SRY TG mice were generated, and subjected to I/R insult with their littermate WT controls in vivo. In vitro experiments were performed by treating primary hepatocytes from TG and WT mice with hypoxia/reoxygen-ation stimulation. RESULTS: Clinical data showed that postoperative aminotransferase level, incidence of overall morbidity and liver failure were markedly higher among 1267 male versus 508 female patients who underwent hepatic resection. SRY was dramatically upregulated during hepatic I/R injury. Overexpression of SRY in male TG mice and ectopic expression of SRY in female TG mice exacerbated liver I/R injury compared with WTs as manifested by increased inflammatory reaction, oxidative stress and cell death in vivo and in vitro. Mechanistically, SRY interacts with Glycogen synthase kinase-3ß (GSK-3ß) and ß-catenin, and promotes phosphorylation and degradation of ß-catenin, leading to suppression of the downstream FOXOs, and activation of NF-κBand TLR4 signaling. Furthermore, activation of ß-catenin almost completely reversed the SRYoverexpression-mediated exacerbation of hepatic I/R damage. CONCLUSIONS: SRY is a novel hepatic I/R mediator that promotes hepatic inflammatory reaction, oxidative stress and cell necrosis via inhibiting Wnt/ß-catenin signaling, which accounts for the sex-based disparity in hepatic I/R injuries.

Liver fibrosis promotes immune escape in hepatocellular carcinoma via GOLM1-mediated PD-L1 upregulation.

Immune checkpoint blockade is considered a breakthrough in cancer treatment. However, with the low response rates and therapeutic resistance of patients with hepatocellular carcinoma (HCC), the challenges facing the application of this treatment are tremendous. Liver fibrosis is a key driver of tumor immune escape, the underlying mechanism has never been clarified. This study sought to explore the role of liver fibrosis in regulating tumor-infiltrating lymphocytes (TILs) and inducing tumor immunosuppression. Ninety-nine fixed HCC tissue samples were used to analyze the association between liver fibrosis and immune escape using immunohistochemistry. In HCC patients, low FIB-4 values and high CD8+ T cell infiltration were correlated with prolonged survival. Elevated expression of immune checkpoints and attenuated antitumor immunity were observed in CCl4-induced mice liver fibrosis models and human fibrotic livers compared to control group. GOLM1 levels were increased in livers of patients with fibrosis and mice in response to CCl4-induced liver fibrosis. CD8+ T cell infiltrations were significantly decreased and PD-L1 expression was significantly increased in tumor tissues from hepatocyte-specific GOLM1 transgenic mice (Alb/GOLM1 mice) inducing chemical carcinogenesis compared to their corresponding control WT mice. GOLM1 induced PD-L1 expression via EGFR pathway activation. EGFR inhibitors, especially together with anti-PD-L1 therapy, improved the efficacy of immunotherapy in HCC. These findings illustrate the importance of liver fibrosis-induced immunosuppression as a tumor-promoting mechanism. GOLM1, which is highly upregulated in the fibrotic liver, regulates tumor microenvironmental immune escape via the EGFR/PD-L1 signaling pathway. EGFR blockade may bolster the efficacy of immune checkpoint inhibitors for HCC treatment.

MicroRNA-148b-colony-stimulating factor-1 signaling-induced tumor-associated macrophage infiltration promotes hepatocellular carcinoma metastasis.

BACKGROUND: MicroRNAs (miRNAs) are small non-coding molecules that exhibit important regulatory roles in various biological or cellular functions, including tumor metastasis. However, the detailed mechanisms of the expression and functions of miRNAs in hepatocellular carcinoma (HCC) have not yet been completely investigated. METHODS: In this study, the levels of miR-148b in HCC cells and patient specimens were determined using qPCR assays. MiR-148b-overexpressing HCC cells were used to investigate the effect of miR-148b in vitro and in vivo. The relationship between the expression of miR-148b and colony stimulating factor-1 (CSF1) in HCC patients and the infiltration of macrophages into the tumor microenvironment were assessed by immunohistochemical staining. RESULTS: MiR-148b expression was decreased in metastatic HCC cells. A positive association between downregulated miR-148b expression and several clinical parameters, including recurrence, metastasis, and poor prognosis, was observed in patients with HCC. The results of bio-functional experiments indicated that the biological characteristics of HCC cells were not affected by miR-148b deficiency in vitro. However, miR-148b deficiency significantly enhanced the progression and metastasis of HCC in nude mice. By analyzing the gene expression profiles, we demonstrated that CSF1 was regulated by miR-148b and that miR-148b deficiency promoted HCC growth and metastasis through CSF1/CSF1 receptor (CSF1R)-mediated tumor-associated macrophage (TAM) infiltration. These results were supported by the negative relationship between miR-148b and CSF1 expression and TAM infiltration in HCC patients. Moreover, HCC patients with low miR-148b levels and high TAM infiltration were associated with poorer prognosis. CONCLUSION: MiR-148b-CSF1 signaling-induced TAM infiltration promotes HCC metastasis. Therefore, miR-148b plays a suppressor role in HCC and might be a potential prognostic factor and therapeutic candidate for HCC.

Baicalein and baicalin promote antitumor immunity by suppressing PD-L1 expression in hepatocellular carcinoma cells.

Blocking the PD-L1/PD-1 pathway to prevent the immune evasion of tumor cells is a powerful approach for treating multiple cancers, including hepatocellular carcinoma (HCC). Previous studies have shown that baicalein and baicalin are directly cytotoxic to some tumors, here we demonstrate that in addition to direct cytotoxicity, these two flavonoids stimulate the T cell mediated immune response against tumors through reduction of PD-L1 expression in cancer cells. Interestingly, more significant tumor regression was observed in BALB/c mice than in BALB/c-nu/nu mice after baicalein and baicalin treatment. PD-L1 upregulation induced by interferon-γ (IFN-γ) was significantly inhibited by these two flavonoids in vitro. Both baicalein and baicalin enhanced the cytotoxicity of T cells to eliminate tumor cells, which was abrogated after HCC cells were transfected with a PD-L1 overexpression plasmid or after T cells were pretreated with an anti-PD-1 blocking antibody. Further mechanistic research indicated that the IFN-γ-induced expression and promoter activity of PD-L1 were suppressed by these two flavonoids, and these effects were mediated by STAT3 activity inhibition. Therefore, baicalein and baicalin decreased STAT3 activity, further downregulated IFN-γ-induced PD-L1 expression and subsequently restored T cell sensitivity to kill tumor cells. Our findings provide novel insight into the anticancer effects of baicalein and baicalin through which tumor growth is inhibited by PD-L1 expression downregulation and suggest that these flavonoids have great potential for clinical treatment.

Serum GP73 predicts posthepatectomy outcomes in patients with hepatocellular carcinoma.

BACKGROUND AND AIMS: Serum GP73 is a useful biomarker in assessing hepatic fibrosis degree. The aim of this study was to evaluate the predictive value of serum GP73 level for posthepatectomy short-term outcomes in hepatocellular carcinoma (HCC) patients. METHODS: A total of 280 patients undergoing liver resection for HCC between October 2015 and April 2018 were included in this study. Detailed preoperative clinicopathological data were collected and GP73 levels in serum obtained the day before hepatectomy were examined. Receiver operating characteristic (ROC) analysis was used to calculate the optimal cutoff of GP73, and independent risk factors for postoperative outcomes was assessed by logistic regression model. RESULTS: The mean GP73 level in patients was 111.8 ± 153.3 ng/mL. Serum GP73 levels were correlated with the METAVIR fibrosis score. Overall complications occurred in 145 patients and major complications developed in 29 patients. ROC analysis demonstrated that the predictive power of serum GP73 for postoperative outcomes was greater than the Child-Pugh score, ALBI score, FIB-4 index and APRI score. The optimal value of serum GP73 to predict overall complications and major complications was 80.9 and 79.2 respectively. Serum GP73 levels were independent factors affecting the incidence of overall complications (odds ratio [OR], 3.996; 95% CI 2.152-7.421; P < 0.001) and major complications (OR, 4.970; 95% CI 1.654-14.934; P = 0.004) by multivariate analysis. CONCLUSION: Serum GP73 is a useful tool to stratify HCC patients and to predict short-term outcomes after hepatectomy.

Serum Irisin Predicts Posthepatectomy Complications in Patients with Hepatocellular Carcinoma.

BACKGROUND: Hepatectomy remains one of the most effective treatments for patients with hepatocellular carcinoma (HCC); however, it can lead to serious complications. Irisin, a key regulator of energy metabolism, is secreted into the circulation by shedding of the extracellular portion of the fibronectin type III domain-containing 5 (FNDC5). We have shown that irisin administration alleviates liver ischemia-reperfusion injury in mice. However, the role of preoperative irisin levels in HCC patients who underwent hepatectomy remained unknown. The purpose of this study was to determine how irisin expression changes in HCC and to explore the relationship between preoperative serum irisin levels and complications after hepatectomy. METHODS: FNDC5/irisin expression data in HCC were extracted from The Cancer Genome Atlas (TCGA) dataset. A total of 219 participants, including 102 healthy controls and 117 HCC patients, were recruited in this study. All HCC patients underwent hepatectomy at the First Affiliated Hospital of the Xi'an Jiaotong University. Preoperative serum irisin levels were measured by ELISA. Postoperative complications were assessed using the comprehensive complication index (CCI) score. The Pearson rank correlation coefficient was computed to assess the correlation between preoperative serum irisin levels and postoperative CCI scores. RESULTS: In TCGA dataset, FNDC5/irisin expression was downregulated in HCC tissues (P < 0.001). Similarly, serum irisin levels were decreased in HCC patients (P < 0.001). Low preoperative serum irisin levels were significantly correlated with high CCI scores after hepatectomy. CONCLUSIONS: Irisin may be a novel serum biomarker in the diagnosis of HCC and a predictor of complications after hepatectomy.

Gamma-glutamyl transpeptidase to platelet ratio predicts short-term outcomes in hepatocellular carcinoma patients undergoing minor liver resection.

BACKGROUND: There is a strong correlation between liver fibrosis and postoperative morbidity after hepatectomy in hepatocellular carcinoma (HCC) patients. The aim of this study was to evaluate which noninvasive fibrosis index (gamma-glutamyl transpeptidase to platelet ratio [GPR], aspartate aminotransferase to platelet ratio index, fibrosis-4 index, or Forns index) was best able to predict complications in patients undergoing hepatectomy for HCC. MATERIALS AND METHODS: This retrospective analysis included 275 patients who underwent hepatectomy for HCC from January 2008 to December 2012. Postoperative mortality was defined as death within 90 d after surgery. Complications were grouped into seven grades on the basis of the modified Clavien classification, and major postoperative complications were defined as grade 3 or above. The influence of noninvasive fibrosis indices on postoperative outcomes was assessed by receiver operating characteristic analysis. The primary outcomes were overall complications and major complications, estimated by univariate and multivariate analysis. RESULTS: Patients with HCC undergoing anatomical liver resection in the authors' department were evaluated for this study. Finally, 275 patients who underwent minor liver resection (≤2 liver segments) were included. Of these, 231 (84%) were male. The multivariate analysis indicated that the GPR index was not only independently associated with overall complications (hazard ratio, 2.692; 95% confidence interval [CI], 1.626-4.250; P < 0.001) but also independently predictive of major complications (hazard ratio, 1.143; 95% CI, 1.046-1.249; P = 0.03). The areas under the receiver operating characteristic curve for predicting overall complications and major complications for the GPR index were 0.704 (95% CI, 0.643-0.765; P < 0.001) and 0.752 (95% CI, 0.638-0.865; P < 0.001), respectively. CONCLUSIONS: The data suggested that the GPR index could be a promising predictor of overall postoperative complications and major complications after minor hepatectomy for HCC.

Natural killer T cell ligand alpha-galactosylceramide protects against gut ischemia reperfusion-induced organ injury in mice.

BACKGROUND & AIMS: Gut ischemia reperfusion (I/R) injury is a life-threatening condition. The immune response plays an important role in I/R-induced organ injury. Alpha-galactosylceramide (α-GalCer) is a potent natural killer T (NKT) cell stimulator. Activation of NKT cells by α-GalCer has been shown to reduce I/R-induced injury in the liver and heart. However, whether α-GalCer has any protective effects on gut I/R-induced organ injury remained unknown. The aim of this study was to test the hypothesis that α-GalCer attenuates gut I/R-induced local and remote organ injury through modulating immune responses. METHODS: Gut ischemia was induced by placing a microvascular clip across the superior mesenteric artery for 30 min in male adult mice. After removing the clip, α-GalCer (2 µg/mouse) or normal saline containing 0.5% Tween 20 (Vehicle) was administered intraperitoneally. Blood, gut, lung and mesenteric lymph node (MLN) samples were collected 4 h after reperfusion to detect bacterial translocation, tight junction protein, tissue damage, edema, apoptosis, IL-4, IL-10, IFN-γ and TNF-α levels. RESULTS: α-GalCer significantly reduced bacterial translocation to the MLN, restored tight junction protein and attenuated gut and lung injury after gut I/R. α-GalCer markedly stimulated the production of IL-4, IL-10 and IFN-γ, but had no obvious effects on TNF-α production in gut I/R mice. Pretreatment with anti-CD1d, IL-4 or IL-10, but not IFN-γ blocking antibodies abolished the protective effects of α-GalCer in gut I/R. CONCLUSIONS: α-GalCer treatment improved gut barrier function and attenuated gut and lung injury after gut I/R. The beneficial effects of α-GalCer in gut I/R were NKT cell dependent and mediated through upregulation of IL-4 and IL-10. Thus, activation of NKT cells by α-GalCer may serve as a novel option in the treatment of gut I/R injury.

MEL-pep, an analog of melittin, disrupts cell membranes and reverses 5-fluorouracil resistance in human hepatocellular carcinoma cells.

Chemotherapy resistance represents a major obstacle in the treatment of patients with hepatocellular carcinoma (HCC). The purpose of this study was to investigate the anti-cancer effect of MEL-pep, a novel analog of the natural antibacterial peptide melittin (MEL), on human 5-fluorouracil-resistant HCC cells (BEL-7402/5-FU) and to clarify the molecular mechanisms involved in these effects. We found that MEL-pep inhibited the proliferation of BEL-7402/5-FU cells and reversed 5-FU resistance in vitro. MEL-pep directly bound to BEL-7402/5-FU cells and disrupted the cell membrane. P-glycoprotein (P-gp) plays an important role in the development of resistance to anticancer drugs. We found that MEL-pep inhibited P-gp expression and increased the intracellular accumulation of the P-gp substrate rhodamine-123 in BEL-7402/5-FU cells. Additionally, the phosphorylation of Akt and NF-κB/p65 nuclear translocation was all inhibited by MEL-pep. Insulin - like growth factor I, a phosphatidylinositol 3 kinase(PI3K) /protein kinase B(AKT) agonist, reversed MEL-pep induced P-gp suppression. Therefore, MEL-pep inhibited P-gp expression by deactivating the PI3K/Akt signaling pathway. Finally, in a BEL-7402/5-FU cell-derived xenograft tumor model in mice, we found that the intratumoral administration of MEL-pep inhibited tumor growth in a dose-dependent manner. Thus, MEL-pep could be a promising candidate in the treatment of chemotherapy resistant HCC.

Collagen I promotes hepatocellular carcinoma cell proliferation by regulating integrin ß1/FAK signaling pathway in nonalcoholic fatty liver.

Nonalcoholic fatty liver disease (NAFLD) has become a major risk factor for hepatocellular carcinoma (HCC) worldwide. However, the underlying mechanism remains insufficiently elucidated. The expression of Collagen I, an important component of extracellular matrix (ECM), was increased during the progression from simple steatosis to NASH. The purpose of this study was to investigate the role of Collagen I in NAFLD-related HCC. To study this, the decellularized liver matrix, which preserves the pathological changes of ECM, was prepared from the human fatty liver (FLM) and human normal liver (NLM). HepG2 cells cultured in FLM had a higher proliferation rate than those in NLM. SMMC-7721 and HepG2 cells cultured on Collagen I-coated plates grew faster than those on either Collagen IV- or fibronectin-coated plates. This effect was dose-dependent and associated with elevated integrin ß1 expression and activation of downstream phospho-FAK. Knocking down the expression of integrin ß1 significantly decreased the proliferation of HCC cells. Additionally, an orthotopic tumor model was established in NAFLD mice at different stages. The over-expressed Collagen I in the mice liver increased the expression of integrin ß1 and downstream phospho-FAK, resulting in the proliferation of HCC cells. This proliferation could be inhibited by blocking the integrin ß1/FAK pathway. In summary, our study demonstrated that Collagen I promoted HCC cell proliferation by regulating the integrin ß1/FAK pathway. Decellularized liver matrix can be used as a platform to three-dimensionally culture HCC cells and reproduce the impact of changed ECM on the progression of NAFLD-related HCC.

Activation of SRY accounts for male-specific hepatocarcinogenesis: Implication in gender disparity of hepatocellular carcinoma.

Sex affects the risk, treatment responses and outcome of many types of cancers. The mechanism of gender disparity in development of hepatocellular carcinoma (HCC) remains obscure. Sex-determining region on Y chromosome (SRY) was overexpressed in approximate 84% male patient HCC. Moreover, we are the first to generate a liver-specific transgenic (TG) murine model with overexpression of the male specific gene SRY. Subject to a single intraperitoneal injection N-nitrosodiethylamine (DEN) at day 14, TG and wildtype (WT) mice of both genders were sacrificed at different time points (6-13.5 months). Overexpression of SRY in male TG and ectopic expression of SRY in female TG livers promoted DEN-induced hepatocarcinogenesis compared to age- and sex-matched WT. This accelerated tumorigenesis in TG of both genders was a consequence of increased injury and inflammation, fibrosis, and compensatory enhancement in hepatocytes proliferation secondary to activation of downstream targets Sox9 and platelet-derived growth factor receptor α (PDGFRα)/phosphoinositide 3-kinase (PI3K)/Akt and c-myc/CyclinD1. In conclusion, activation of SRY and its downstream Sox9 and PDGFRα pathways are commonly involved in male hepatocarcinogenesis, which provides novel insights into gender disparity and sex-specific therapeutic strategies of HCC.

A polysaccharide component from Strongylocentrotus nudus eggs inhibited hepatocellular carcinoma in mice by activating T lymphocytes.

A component purified from Strongylocentrotus nudus eggs on a diethylaminoethyl cellulose-52 chromatography column and eluted using a NaCl solution gradient (SEP-S), is a homogeneous polysaccharide of α-D-glucan with a reduced molecular weight of 9.33×105 Da, compared with that of S. nudus egg polysaccharide (SEP). In an in vivo antitumor assay of histocompatibility-22 hepatocellular carcinoma in tumor-bearing mice, the inhibitory rates at SEP-S doses of 5, 10 and 20 mg/kg/day were 38.8, 50.7 and 70.3%, respectively. In addition, the spleen and thymus indices and the percentages of cluster of differentiation (CD) 4+ and CD8+ T cells were significantly increased, and the activity of cytotoxic T lymphocytes was notably enhanced, suggesting that the anti-hepatocellular carcinoma activity is mediated by boosting the immune system. In vitro experiments also demonstrated that splenocyte proliferation induced by SEP-S was inhibited by the toll-like receptor (TLR) 2 and TLR4 monoclonal antibodies. These data indicate that SEP-S is a polysaccharide component possessing high anti-hepatocellular carcinoma activity and may be a potential immunotherapy candidate for the treatment of liver cancer.

Prognostic nutritional index predicts short-term outcomes after liver resection for hepatocellular carcinoma within the Milan criteria.

BACKGROUND: The prognostic nutritional index (PNI) is calculated based on the serum albumin concentration and the total lymphocyte count. The aim of this study was to investigate the prognostic ability of the PNI for postoperative complications after liver resection to treat hepatocellular carcinoma (HCC) within the Milan criteria. RESULTS: Postoperative complications were observed in 166 (44.6%) patients. The optimal cutoff value of the PNI was set at 45.6 for postoperative complications. Patients in the PNI-low (PNI < 45.6) group were more likely to have postoperative complications, more blood loss, a longer surgery time and a longer hospital stay than patients in the PNI-high group (PNI > 45.6). Our regression analysis demonstrated that the preoperative PNI and albumin-bilirubin (ALBI) score were significantly associated with postoperative complications (Pearson correlation coefficient, -0.865, p < 0.001). The multivariate analysis revealed that the PNI was an independent predictor of postoperative complications. MATERIALS AND METHODS: Three-hundred and seventy-two patients who underwent partial hepatectomy for HCC from 2003 to 2014 were identified. The cutoff value of the PNI was determined by a receiver operating characteristic (ROC) curve analysis. Univariate and multivariate analyses were performed to identify clinicopathological features associated with postoperative complications. CONCLUSION: The PNI may be a significant prognostic factor for evaluating short-term outcomes of patients with HCC after partial hepatectomy.

SEP enhanced the antitumor activity of 5-fluorouracil by up-regulating NKG2D/MICA and reversed immune suppression via inhibiting ROS and caspase-3 in mice.

Chemotherapy and immunotherapy are the main remedies used in cancer treatment. Because immunotherapy can not only reduce the toxicity of chemotherapeutics but also enhance antitumor effects in vivo, combining these two therapies is a trend that continues to gain more attention in clinic. SEP, a polysaccharide isolated from Strongylocentrotus nudus egg, has been reported to display antitumor activity by stimulating immune cells, including NK and T cells, via TLR2 and TLR4. In the present study, the synergistic effect between SEP and 5-fluorouracil (5-FU), a traditional cytotoxic drug, in vitro and in vivo was investigated. The results obtained indicated that SEP alone stimulated NK-92 cytotoxicity and coordinated with 5-FU to augment the cytotoxicity of NK-92 cells against HepG-2 or A549 cells in vitro. SEP promoted NK-92 activity by stimulating NKG2D and its downstream DAP10/PI3K/Erk signaling pathway. Additionally, 5-FU could increase MICA expression on HepG-2 or A549 cells and prevent membrane MICA from shedding as soluble MICA, which were abrogated in the tumor cells transfected with ADAM 10 overexpression plasmid. Moreover, in H22- or Lewis lung cancer (LLC)-bearing mouse models, SEP reversed 5-FU-induced atrophy and apoptosis in both the spleen and bone marrow in vivo by suppressing ROS generation and caspase-3 activation. All of these results highlight the potential for the combination of SEP and 5-FU in cancer therapy in the future.

The anti-lung cancer activity of SEP is mediated by the activation and cytotoxicity of NK cells via TLR2/4 in vivo.

Strongylocentrotus nudus egg polysaccharide (SEP) has been reported to display antitumor activity. However, the effects of SEP and its underlying mechanism in the treatment of lung cancer remain unclear, particularly with an immunodeficient mouse model of human non-small cell lung cancer (NSCLC). In the present study, we investigated the anti-lung cancer effects of SEP and its underlying mechanism of action in both Lewis lung cancer (LLC)-bearing C57/BL6J mice and human NSCLC H460-bearing nude mice. Although SEP showed no inhibitory effects on tumor cells in vitro, it markedly stimulated the percentage of CD3-NK1.1(+) cells and natural killer (NK) cell cytotoxicity in the spleens of nude mice and C57/BL6J mice. In LLC-bearing mice, SEP not only inhibited tumor growth but also promoted NK-mediated cytotoxicity, the NK1.1(+) cell population, and IL-2 and IFN-γ secretion. SEP significantly suppressed H460 growth in nude mice, which was abrogated by the selective depletion of NK cells via the intraperitoneal injection of anti-asialo GM-1 antibodies. Furthermore, anti-TLR2/4 antibodies blocked both SEP and NK cell binding and SEP-induced perforin secretion. SEP-induced proliferation and IFN-γ secretion by NK cells in wild type mice were partially impaired in TLR2 or TLR4 knockout mice. These results suggest that SEP-promoted NK cytotoxicity, which was partially mediated via TLR2 and TLR4, was the main contributing factor to lung cancer inhibition in vivo and that SEP may be a potential immunotherapy candidate for the treatment of lung cancer.

The cathelicidin-BF Lys16 mutant Cbf-K16 selectively inhibits non-small cell lung cancer proliferation in vitro.

The 30-amino acid antimicrobial peptide Cbf-K16 is a cathelicidin-BF (BF-30) Lys16 mutant derived from the snake venom of Bungarus fasciatus. Our previous study found that BF-30 selectively inhibited the proliferation of the metastatic melanoma cell line B16F10 in vitro and in vivo, but had a negligible effect on human lung cells. In the present study, it was demonstrated for the first time that Cbf-K16 selectively inhibits the proliferation of lung carcinoma cells in vitro, with low toxicity to normal cells. The half-maximal inhibitory concentrations (IC50) of Cbf-K16 against H460 human non-small cell lung carcinoma cells and mouse Lewis lung cancer cells were only 16.5 and 10.5 µM, respectively, which were much less compared to that of BF-30 (45 and 40.3 µM). Data using a transmission electron microscope (TEM) assay showed that, at 20 and 40 µM, Cbf-K16 induced the rupture of the cytoplasmic membrane, which was consistent with data obtained from lactate dehydrogenase (LDH) release assays. The LDH release increased from 17.8 to 52.9% as the duration and dosage of Cbf-K16 increased. Annexin V-fluorescein and propidium iodide staining assays indicated that there were no obvious apoptotic effects at the different dosages and times tested. In H460 cells, the rate of genomic DNA binding increased from 51.9 to 86.8% as the concentration of Cbf-K16 increased from 5 to 10 µM. These data indicate that Cbf-K16 selectively inhibits the proliferation of lung carcinoma cells via cytoplasmic membrane permeabilization and DNA binding, rather than apoptosis. Although Cbf-K16 displayed significant cytotoxic activity (40 µM) against tumor cells, in splenocytes no significant inhibitory effect was observed and hemolysis was only 5.6%. These results suggest that Cbf-K16 is a low-toxicity anti-lung cancer drug candidate.

BF-30 selectively inhibits melanoma cell proliferation via cytoplasmic membrane permeabilization and DNA-binding in vitro and in B16F10-bearing mice.

Cathelicidin-BF (BF-30) is a cathelicidin-like polypeptide composed of 30 amino acids and is a natural antibacterial peptide extracted from the venom of the snake Bungarus fasciatus. In our previous study, BF-30 showed broad antimicrobial activity against drug-resistant bacteria through enhancing the cytoplasmic membrane permeability. However, the anticancer activity of BF-30 has not yet been investigated. In this study, the effects of BF-30 on the proliferation of the metastatic melanoma cell line B16F10 in vitro and in vivo, as well as the mechanism were studied. Assay of cell viability, a B16F10-bearing mouse model, and histochemical examination were utilized to investigate the anti-tumor effects of BF-30. In addition, transmission electron microscope analysis, lactate dehydrogenase release assay, DNA retardation assay, Real-time PCR, Western blot, wound healing assay, and chick embryo chorioallantoic membrane assay were applied to elucidate the mechanism of BF-30 on B16F10. BF-30 inhibited B16F10 and B16 proliferation in vitro in a dose- and time-dependent manner with an IC50 of 7.3 µM and 13.9 µM, respectively. Moreover, BF-30 significantly suppressed melanoma growth in B16F10-bearing mice without body weight loss. The observed inhibition were 41.4%, 49.5% and 63.5% at the doses of 0.75, 1.5 and 3 mg/kg/day, respectively. This inhibition of metastatic melanoma cell proliferation was partially dependent on disrupting the cytoplasmic membrane, binding to genomic DNA, preventing transcription and translation of the VEGF gene. This inhibition restrained B16F10 migration and angiogenesis. These results further suggest that BF-30 may be a candidate for the treatment of malignant melanoma.

Effective inhibition of a Strongylocentrotus nudus eggs polysaccharide against hepatocellular carcinoma is mediated via immunoregulation in vivo.

This study was aimed at evaluating the inhibitory effect of a polysaccharide that was isolated from Strongylocentrotus nudus eggs (SEP) against hepatocellular carcinoma in H22-bearing mice and elucidating its immunological mechanisms by determining its effects on the growth of transplanted tumors and immune response in H22-bearing mice. ICR mice inoculated with mouse hepatoma carcinoma cell lines H22 were treated with SEP at doses of 4, 8, 16 mg/kg/d for 12 days. The effects of SEP were measured via the growth of the transplanted tumors, splenocyte proliferation, T lymphocytes counts, CTL activity, the production of cytokines from splenocytes and the levels of serum Ig in tumor-bearing mice. In addition, the effects of SEP on Erk phosphorylation in mouse splenocytes and on the transcriptional activity of NFAT in Jurkat T cells were also investigated. Our results showed that SEP significantly inhibited the growth of transplanted tumors in mice. SEP could not only remarkably enhance splenocyte proliferation, CD4(+) and CD8(+) T cell numbers as well as CTL activity, but it also elevated IL-2 and TNF-α secretion as well as IgA, IgM and IgG levels in the serum. Furthermore, the activation of Erk phosphorylation and the NFAT promoter by SEP promoted the transcription and expression of downstream gene IL-2. In conclusion, our study demonstrates that SEP effectively inhibits hepatocellular carcinoma in vivo via enhancement of host immune system function, and it could be a potential therapeutic drug for hepatocarcinoma.