Salmonella-mediated methionine deprivation drives immune activation and enhances immune checkpoint blockade therapy in melanoma.

BACKGROUND: Although immune checkpoint inhibitor (ICI)-based therapy is advantageous for patients with advanced melanoma, resistance and relapse are frequent. Thus, it is crucial to identify effective drug combinations and develop new therapies for the treatment of melanoma. SGN1, a genetically modified Salmonella typhimurium species that causes the targeted deprivation of methionine in tumor tissues, is currently under investigation in clinical trials. However, the inhibitory effect of SGN1 on melanoma and the benefits of SGN1 in combination with ICIs remain largely unexplored. Therefore, this study aims to investigate the antitumor potential of SGN1, and its ability to enhance the efficacy of antibody-based programmed cell death-ligand 1 (PD-L1) inhibitors in the treatment of murine melanoma. METHODS: The antitumor activity of SGN1 and the effect of SGN1 on the efficacy of PD-L1 inhibitors was studied through murine melanoma models. Further, The Cancer Genome Atlas-melanoma cohort was clustered using ConsensusClusterPlus based on the methionine deprivation-related genes, and immune characterization was performed using xCell, Microenvironment Cell Populations-counter, Estimation of Stromal and Immune cells in MAlignant Tumor tissues using Expression data, and immunophenoscore (IPS) analyses. The messenger RNA data on programmed death-1 (PD-1) immunotherapy response were obtained from the Gene Expression Omnibus database. Gene Set Enrichment Analysis of methionine deprivation-up gene set was performed to determine the differences between pretreatment responders and non-responders. RESULTS: This study showed that both, the intratumoral and the intravenous administration of SGN1 in subcutaneous B16-F10 melanomas, suppress tumor growth, which was associated with an activated CD8+T-cell response in the tumor microenvironment. Combination therapy of SGN1 with systemic anti-PD-L1 therapy resulted in better antitumor activity than the individual monotherapies, respectively, and the high therapeutic efficacy of the combination was associated with an increase in the systemic level of tumor-specific CD8+ T cells. Two clusters consisting of methionine deprivation-related genes were identified. Patients in cluster 2 had higher expression of methionine_deprivation_up genes, better clinical outcomes, and higher immune infiltration levels compared with patients in cluster 1. Western blot, IPS analysis, and immunotherapy cohort study revealed that methionine deficiency may show a better response to ICI therapy CONCLUSIONS：: This study reports Salmonella-based SGN1 as a potent anticancer agent against melanoma, and lays the groundwork for the potential synergistic effect of ICIs and SGN1 brought about by improving the immune microenvironment in melanomas.

Prognosis prediction based on methionine metabolism genes signature in gliomas.

BACKGROUND: Glioma cells have increased intake and metabolism of methionine, which can be monitored with 11 C-L-methionine. However, a short half-life of 11 C (~ 20 min) limits its application in clinical practice. It is necessary to develop a methionine metabolism genes-based prediction model for a more convenient prediction of glioma survival. METHODS: We evaluated the patterns of 29 methionine metabolism genes in glioma from the Cancer Genome Atlas (TCGA). A risk model was established using Lasso regression analysis and Cox regression. The reliability of the prognostic model was validated in derivation and validation cohorts (Chinese Glioma Genome Atlas; CGGA). GO, KEGG, GSEA and ESTIMATE analyses were performed for biological functions and immune characterization. RESULTS: Our results showed that a majority of the methionine metabolism genes (25 genes) were involved in the overall survival of glioma (logrank p and Cox p < 0.05). A 7-methionine metabolism prognostic signature was significantly related to a poor clinical prognosis and overall survival of glioma patients (C-index = 0.83). Functional analysis revealed that the risk model was correlated with immune responses and with epithelial-mesenchymal transition. Furthermore, the nomogram integrating the signature of methionine metabolism genes manifested a strong prognostic ability in the training and validation groups. CONCLUSIONS: The current model had the potential to improve the understanding of methionine metabolism in gliomas and contributed to the development of precise treatment for glioma patients, showing a promising application in clinical practice.

[Effects of Methionine Restriction on Proliferation, Cell Cycle, and Apoptosis of Human Acute Leukemia Cells].

OBJECTIVE: To investigate the effects of methionine restriction on proliferation, cell cycle and apoptosis of human acute leukemia cells. METHODS: Cell Counting Kit-8 (CCK-8) assay was used to detect the effect of methionine restriction on HL-60 and Jurkat cells proliferation. The effect of methionine restriction on cell cycle of HL-60 and Jurkat cells was examined by PI staining. Annexin V-FITC / PI double staining was applied to detect apoptosis of HL-60 and Jurkat cells following methionine restriction. The expression of cell cycle-related proteins cyclin B1, CDC2 and apoptosis-related protein Bcl-2 was evaluated by Western blot assay. RESULTS: Methionine restriction significantly inhibited the proliferation of HL-60 and Jurkat cells in a time-dependent manner (HL-60: r =0.7773, Jurkat: r =0.8725), arrested the cells at G2/M phase (P < 0.001), and significantly induced apoptosis of HL-60 and Jurkat cells (HL-60: P < 0.001; Jurkat: P < 0.05). Furthermore, Western blot analysis demonstrated that methionine restriction significantly reduced the proteins expression of Cyclin B1 (P < 0.05), CDC2 (P < 0.01) and Bcl-2 (P < 0.001) in HL-60 and Jurkat cells. CONCLUSION: Acute leukemia cells HL-60 and Jurkat exhibit methionine dependence. Methionine restriction can significantly inhibit the proliferation, promote cell cycle arrest and induce apoptosis of HL-60 and Jurkat cells, which suggests that methionine restriction may be a potential therapeutic strategy for acute leukemia.

Targeted deprivation of methionine with engineered Salmonella leads to oncolysis and suppression of metastasis in broad types of animal tumor models.

The strong dependency of almost all malignant tumors on methionine potentially offers a pathway for cancer treatment. We engineer an attenuated strain of Salmonella typhimurium to overexpress an L-methioninase with the aim of specifically depriving tumor tissues of methionine. The engineered microbes target solid tumors and induce a sharp regression in several very divergent animal models of human carcinomas, cause a significant decrease in tumor cell invasion, and essentially eliminate the growth and metastasis of these tumors. RNA sequencing analyses reveal that the engineered Salmonella reduce the expression of a series of genes promoting cell growth, cell migration, and invasion. These findings point to a potential treatment modality for many metastatic solid tumors, which warrants further tests in clinical trials.

Endogenous production of ω-3 polyunsaturated fatty acids mitigates cisplatin-induced myelosuppression by regulating NRF2-MDM2-p53 signaling pathway.

Cisplatin is a chemotherapy medication used to treat a wide range of cancers. A common side effect of cisplatin is myelosuppression. Research suggests that oxidative damages are strongly and consistently related to myelosuppression during cisplatin treatment. ω-3 polyunsaturated fatty acids (PUFAs) can enhance the antioxidant capacity of cells. Herein, we investigated the protective benefit of endogenous ω-3 PUFAs on cisplatin-induced myelosuppression and the underlying signaling pathways using a transgenic mfat-1 mouse model. The expression of mfat-1 gene can increase endogenous levels of ω-3 PUFAs by enzymatically converting ω-6 PUFAs. Cisplatin treatment reduced peripheral blood cells and bone marrow nucleated cells, induced DNA damage, increased the production of reactive oxygen species, and activated p53-mediated apoptosis in bone marrow (BM) cells of wild-type mice. In the transgenics, the elevated tissue ω-3 PUFAs rendered a robust preventative effect on these cisplatin-induced damages. Importantly, we identified that the activation of NRF2 by ω-3 PUFAs could trigger an antioxidant response and inhibit p53-mediated apoptosis by increasing the expression of MDM2 in BM cells. Thus, endogenous ω-3 PUFAs enrichment can strongly prevent cisplatin-induced myelosuppression by inhibiting oxidative damage and regulating the NRF2-MDM2-p53 signaling pathway. Elevation of tissue ω-3 PUFAs may represent a promising treatment strategy to prevent the side effects of cisplatin.

Pharmacological targeting of type phosphodiesterase 4 inhibits the development of acute myeloid leukemia by impairing mitochondrial function through the Wnt/ß-catenin pathway.

Acute myeloid leukemia (AML) is prone to drug-resistant relapse with a low 5-year survival rate. New therapeutic modalities are sorely needed to provide hope for AML relapse patients. Herein, we demonstrated a specific inhibitor of type 4 phosphodiesterase (PDE4), Zl-n-91, could significantly reduce the proliferation of AML cells, block DNA replication process, and increase AML cell death. Zl-n-91 also impeded the growth of subcutaneous xenograft and prolonged the survival of the MLL-AF9-driven AML model. Bioinformatic analysis revealed that elevated mitochondrial gene signatures inversely correlate with the survival of AML patients; and importantly, Zl-n-91 strongly suppressed the function of mitochondria. In addition, this PDE4 inhibitor induced alterations in multiple signaling pathways, including the reduction of ß-catenin activity. Stimulation of the Wnt/ß-catenin pathway could attenuate the inhibitory effect of Zl-n-91 on AML cell proliferation as well as mitochondrial function. Taken together, we revealed for the first time that targeting PDE4 activity could attenuate mitochondrial function through a Wnt/ß-catenin pathway, which in turn would block the growth of AML cells. Specific PDE4 inhibitors can potentially serve as a new treatment modality for AML patients.

Effective extraction of bioactive alkaloids from the roots of Stephania tetrandra by deep eutectic solvents-based ultrasound-assisted extraction.

The efficient and green extraction of bioactive ingredients from natural plants play a vital role in their corresponding drug effects and subsequent studies. Recently, deep eutectic solvents (DESs) have been considered promising new green solvents for efficiently and selectively extracting substances from varied plants. In this work, an environment-friendly DESs-based ultrasonic-assisted extraction (DESs-UAE) procedure was developed for highly efficient and non-polluting extraction of alkaloids from the roots of Stephania tetrandra (ST). A total of fifteen different combinations of DESs, compared with traditional organic solvents (methanol and 95% ethanol) and water, were evaluated for extraction of bioactive alkaloids (FAN and TET) from ST, and the results revealed that DESs system made up of choline chloride and ethylene glycol with mole ratio of 1:2 exhibited the optimal extraction efficiency for alkaloids. Additionally, a four-factor and three-level Box-Behnken design (BBD), a particular pattern of response surface methodology (RSM), was used to optimize extraction conditions. RSM results indicated that the maximum extraction yields of FAN, TET, and TA were attained 7.23, 13.36, 20.59 mg/g, respectively, within extraction temperature of 52 °C, extraction time of 82 min, DES water content of 23% (v/v), and liquid-solid ratio of 23 mL/g. The measured results were consistent with the predicted values. Notably, the optimized DES extraction efficiency of TA, according to the experimental data analysis, is 2.2, 3.3 and 4.1 times higher than methanol, 95% ethanol and water, respectively. Meanwhile, based on 3D response surface plots, interactive effects plots and contour maps, the effects of the aforementioned four essential factors on the extraction yield and their interactions on the response were visualized. The results revealed that the mutual interactions between extraction temperature and liquid-solid ratio exhibited positive effects on all responses, while extraction time and water content in DES posed a negative effect. Therefore, these results suggest that DESs, as a class of novel green solvents, with the potential to substitute organic solvent and water, can be widely and effectively applied to extract bioactive compounds from natural plants.

Resistin Promotes Nasopharyngeal Carcinoma Metastasis through TLR4-Mediated Activation of p38 MAPK/NF-κB Signaling Pathway.

NPC is a type of malignant tumor with a high risk of local invasion and early distant metastasis. Resistin is an inflammatory cytokine that is predominantly produced from the immunocytes in humans. Accumulating evidence has suggested a clinical association of circulating resistin with the risk of tumorigenesis and a relationship between blood resistin levels and the risk of cancer metastasis. In this study, we explored the blood levels and the role of resistin in NPC. High resistin levels in NPC patients were positively associated with lymph node metastasis, and resistin promoted the migration and invasion of NPC cells in vitro. These findings were also replicated in a mouse model of NPC tumor metastasis. We identified TLR4 as a functional receptor in mediating the pro-migratory effects of resistin in NPC cells. Furthermore, p38 MAPK and NF-κB were intracellular effectors that mediated resistin-induced EMT. Taken together, our results suggest that resistin promotes NPC metastasis by activating the TLR4/p38 MAPK/NF-κB signaling pathways.

Adiponectin Suppresses Metastasis of Nasopharyngeal Carcinoma through Blocking the Activation of NF-κB and STAT3 Signaling.

Adiponectin is an adipocytokine with anti-inflammatory and anticancer properties. Our previous study has shown that blood adiponectin levels were inversely correlated to the risk of nasopharyngeal carcinoma (NPC), and that adiponectin could directly suppress the proliferation of NPC cells. However, the effect of adiponectin on NPC metastasis remains unknown. Here, we revealed in clinical studies that serum adiponectin level was inversely correlated with tumor stage, recurrence, and metastasis in NPC patients, and that low serum adiponectin level also correlates with poor metastasis-free survival. Coculture with recombinant adiponectin suppressed the migration and invasion of NPC cells as well as epithelial-mesenchymal transition (EMT). In addition, recombinant adiponectin dampened the activation of NF-κB and STAT3 signaling pathways induced by adipocyte-derived proinflammatory factors such as leptin, IL-6, and TNF-α. Pharmacological activation of adiponectin receptor through its specific agonist, AdipoRon, largely stalled the metastasis of NPC cells. Taken together, these findings demonstrated that adiponectin could not only regulate metabolism and inhibit cancer growth, but also suppress the metastasis of NPC. Pharmacological activation of adiponectin receptor may be a promising therapeutic strategy to stall NPC metastasis and extend patients' survival.

ZL-n-91, a specific Phosphodiesterase-4 inhibitor, suppresses the growth of triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that frequently develops resistance to chemotherapy. A new approach to treating TNBC is required to improve patient survival. Phosphodiesterase-4 (PDE4) is an enzyme that is predominantly involved in the modulation of intracellular signaling mediated by cAMP. Although the efficacy of PDE4 inhibitors in several human inflammatory diseases is well documented, their clinical utility has been limited by side effects, including nausea and emesis. Recently, PDE4 has been used as a potential therapeutic target for different cancer types. In the present study, we investigated the anticancer effects of a novel PDE4 inhibitor ZL-n-91 on TNBC and the underlying mechanism. We showed that ZL-n-91 inhibited the proliferation of TNBC cells, induced cell apoptosis, and caused cell cycle arrest. Western blot analysis showed that ZL-n-91 increased Bax level and reduced Bcl-2 expression. Furthermore, downregulation of the cell cycle-related proteins, such as CDK2, CDK4, cyclin D1, PCNA, p-RB, and ZL-n-91, significantly inhibited the transcription of DNA repair genes and triggered an intracellular DNA damage response. Moreover, ZL-n-91 prevented the growth of the transplanted MDA-MB-231 tumor xenograft in nude mice and increased the γ-H2AX expression. These data demonstrate the anticancer effects of ZL-n-91 on TNBC cells and suggest its potential use in anticancer therapy.

Adiponectin suppresses tumor growth of nasopharyngeal carcinoma through activating AMPK signaling pathway.

BACKGROUND: Adiponectin is an adipocyte-secreted cytokine that enhances insulin sensitivity and attenuates inflammation. Although circulating adiponectin level is often inversely associated with several malignancies, its role in the development of nasopharyngeal carcinoma (NPC) remains unclear. Here, we investigated the clinical association between circulating adiponectin level and NPC, and examined the impact of adiponectin, as well as the underlying mechanisms, on NPC growth both in vitro and in vivo. METHODS: The association between circulating adiponectin level and the risk of developing NPC was assessed in two different cohorts, including a hospital-based case-control study with 152 cases and 132 controls, and a nested case-control study with 71 cases and 142 controls within a community-based NPC screening cohort. Tumor xenograft model, cell proliferation and cycle assays were applied to confirm the effects of adiponectin on NPC growth in cultured cells and in xenograft models. We also investigated the underlying signaling mechanisms with various specific pharmacological inhibitors and biochemistry analysis. RESULTS: High adiponectin levels were associated with a monotonic decreased trend of NPC risk among males in both the hospital-based case-control study and a nested case-control study. In vitro, recombinant human full-length adiponectin significantly inhibited NPC cell growth and arrested cell cycle, which were dependent on AMPK signaling pathway. The growth of xenograft of NPC tumor was sharply accelerated in the nude mice carrying genetic adiponectin deficiency. An adiponectin receptor agonist, AdipoRon, displayed strong anti-tumor activity in human xenograft models. CONCLUSIONS: These findings demonstrated for the first time that circulating adiponectin is not only inversely associated with NPC, but also controls the development of NPC via AMPK signaling pathway. Stimulation of adiponectin function may become a novel therapeutic modality for NPC.

Adiponectin deficiency promotes endometrial carcinoma pathogenesis and development via activation of mitogen-activated protein kinase.

Obesity is one of the major risk factors for cancer. Clinical studies have demonstrated that circulating levels of adiponectin are inversely correlated, not only with the extent of adiposity, but also with the incidence of several types of cancer, particularly endometrial cancer (EC). However, thus far, adiponectin remains a correlative factor, without definitive evidence to show a causal effect in EC and the potential mechanism(s) involved. To address this issue, we introduced an Apn-null mutation into Pten haploid-deficient (Pten+/- ) mice. The Pten heterozygous mutation alone led to the development of EC in less than 30% of female mice; however, when combined with the Apn-null mutation, the incidence of endometrial lesions rose to at least two-thirds. Although Apn deficiency did not further potentiate the Akt activation caused by the Pten mutation, it elevated the phosphorylation of mitogen-activated protein kinase (MAPK) p42/44, indicating activation of the MAPK signaling pathway. Treatment of Apn-/- ;Pten+/- mice with a MEK inhibitor blocked the development of EC. Finally, xenografts of a PTEN-proficient human EC cell line grew faster in Apn-deficient mice, whereas an adiponectin receptor agonist reduced xenograft growth of a PTEN-deficient human EC cell line. Thus, reduction of adiponectin activity promotes EC development, at least in the context of Pten mutation, by activating MAPK. © 2022 The Pathological Society of Great Britain and Ireland.

[The Effect of Novel Phosphodiesterase 4 Inhibitor ZL-n-91 to the Proliferation of Leukemia Cells].

OBJECTIVE: To investigate the inhibitory effects of novel phosphodiesterase 4 inhibitor ZL-n-91 to the proliferation of leukemia cells L1210 and K562. METHODS: CCK-8 method was used to detect the effect of ZL-n-91 to the proliferation of L1210 and K562 cells, and the proliferation rate, IC50 were calculated. The effects of ZL-n-91 to the cycle of L1210 and K562 cells was detected by PE single staining, and the effects of ZL-n-91 to the apoptosis of L1210 and K562 cells was detected by PE/7AA-D double staining. Western blot was used to detect the effect of ZL-n-91 to the expression levels of apoptosis related proteins. Subcutaneous tumor transplantation model of acute lymphoblastic leukemia L1210 was established in the nude mice, and the inhibitory effect of oral administration of ZL-n-91 to the xenograft was observed. RESULTS: ZL-n-91 showed a significant inhibitory effect to the proliferation of leukemia cells L1210 and K562 in a dose-dependent manner (P<0.001). After treated by ZL-n-91, the leukemia cells L1210 and K562 in the S-phase in cell cycle decreased significantly compared with those in control group (P<0.01). The apoptosis of leukemia cells L1210 and K562 could be induced by ZL-n-91 (P<0.001), and the expression level of apoptosis related protein BAX significantly increased. In the animal experiment, the result showed that ZL-n-91 could significantly inhibit the growth of subcutaneously transplantation tumor (P<0.05). CONCLUSION: The novel phosphodiesterase 4 inhibitor ZL-n-91 can effectively inhibit the proliferation of leukemia cells L1210 and K562, which has the potential of anti-leukemia drug development.

Endogenous production of n-3 polyunsaturated fatty acids protects mice from carbon tetrachloride-induced liver fibrosis by regulating mTOR and Bcl-2/Bax signalling pathways.

NEW FINDINGS: What is the central question of this study? What is the protective benefit of n-3 polyunsaturated fatty acids (PUFAs) on liver fibrosis and what are the relevant signalling pathways in a transgenic mouse model overexpressing the mfat-1 enzyme? What is the main finding and its importance? n-3 PUFA elevation strongly prevented carbon tetrachloride (CCl4 )-induced hepatic damage and inhibited the activation of hepatic stellate cells. n-3 PUFAs suppressed CCl4 -induced activation of mTOR, elevated Bcl-2 expression, and reduced Bax level, suggesting that n-3 PUFAs can render strong protective effects against liver fibrosis and point to the potential of mfat-1 gene therapy as a treatment modality. ABSTRACT: Liver fibrosis is a reversible wound healing response with excessive accumulation of extracellular matrix proteins. It is a globally prevalent disease with ultimately severe pathological consequences. However, very few current clinical therapeutic options are available. Nutritional addition of n-3 polyunsaturated fatty acids (PUFAs) can delay and lessen the development of liver fibrosis. Herein, this study examined the protective benefit of n-3 PUFAs on liver fibrosis and the relevant signalling pathways using a transgenic mouse model overexpressing the mfat-1 enzyme that converts n-6 to n-3 PUFAs. Male C57BL/6 wild-type and mfat-1 transgenic mice were administered carbon tetrachloride (CCl4 ) or control corn oil by intraperitoneal injection. Blood alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were subsequently measured. CCl4 -induced hepatic damage and fibrosis were assessed using haematoxylin-eosin and Masson's trichrome staining. Western blot assays were used to detect and quantify fibrosis-related proteins and mechanistic target of rapamycin (mTOR) and B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) signalling components. The direct effect of docosahexaenoic acid (DHA) on primary hepatic stellate cells (HSCs) was also investigated in a co-culture experiment. n-3 PUFAs, as a result of mfat-1 activity, had a strong protective effect on liver fibrosis. The elevation of ALT and AST induced by CCl4 was significantly lessened in the mfat-1 mice. Histological determination revealed the protective effects of n-3 PUFAs on liver inflammation and collagen deposition. Co-incubation with DHA reduced the expression of profibrogenic factors in the primary HSCs. Moreover, mfat-1 transgenic mice showed significant reduction of proteins that are involved in mTOR and Bcl-2/Bax signalling pathways. Collectively, these results suggest that n-3 PUFA elevation strongly prevents CCl4 -induced hepatic damage by directly inhibiting the activation of HSCs and regulating the basal activity of the mTOR and Bcl-2/Bax signalling pathways. Gene therapy applying mfat-1 and elevating n-3 PUFAs represents a promising treatment strategy to prevent liver fibrosis.

Inhibition of acute leukemia with attenuated Salmonella typhimurium strain VNP20009.

Acute leukemia is a common hematological malignancy. Despite recent promising progress, the prognosis of acute leukemia patients remains to be improved. New therapies are therefore still needed. Salmonella typhimurium has been shown to be highly effective as an anti-tumor agent in many solid cancer models, but it has not been applied in acute leukemia. Here, we report an attenuated Salmonella typhimurium strain, VNP20009, can induce apoptosis in multiple types of leukemia cells both in vivo and in vitro. Furthermore, VNP20009 significantly inhibited the proliferation of MLL-AF9-induced acute myeloid leukemia cells and prolonged the survival of the AML-carrying mice. VNP20009 restored the counts of white blood cell (WBC) and its five subsets in peripheral blood (PB) to near-physiological values, and elevated the levels of certain cytokines, such as tumor necrosis factor-α (TNF-α), leukemia inhibitory factor (LIF), interferon-γ (IFN-γ), chemokine C-X-C motif ligand-10 (CXCL-10) and C-C motif ligand-2 (CCL-2). Moreover, the ratio of immune cells, including natural killer cells (NKs), CD4+ Th1-type cells and CD8+ IFN-γ-producing effector T cells were highly upregulated in the AML mice treated with VNP20009. The results of the present study potentially provide an alternative therapeutic strategy for hematologic malignancies through boosting the innate and adaptive anti-tumor immunity.

Inhibition of lung cancer growth and metastasis by DHA and its metabolite, RvD1, through miR-138-5p/FOXC1 pathway.

BACKGROUND: Non small cell lung cancer (NSCLC) is one of the most common cancers in the world. DHA is known to be capable of suppressing NSCLC cell proliferation and metastasis. However, the mechanisms by which DHA exhibits its antitumor effects are unknown. Here we aimed to identify the effects and mechanisms of DHA and its metabolites on lung cancer cell growth and invasion. METHODS: As measures of cell proliferation and invasion ability, the cell viability and transwell assays were used in vitro. Transgenic mfat-1 mice, which convert ω-6 PUFAs to ω-3 PUFAs, were used to detect the effect of endogenous DHA on tumor transplantation. An LC - MS/MS analysis identified the elevation of several eicosanoid metabolites of DHA. By using qPCR miRNA microarray, online prediction software, luciferase reporter assays and Western blot analysis, we further elucidated the mechanisms. RESULTS: Addition of exogenous DHA inhibited the growth and invasion in NSCLC cells in vitro. Endogenously produced DHA attenuated LLC-derived tumor growth and metastasis in the transgenic mfat-1 mice. Among the elevation of DHA metabolites, resolvin D1 (RvD1) significantly contributed to the inhibition in cell growth and invasion. MiRNA microarray revealed that the level of miR-138-5p was significantly increased after RvD1 treatment. MiR-138-5p mimics decreased cell viability and invasion; while miR-138-5p inhibitor abolished RvD1-mediated suppression of cell viability and invasion. The expression of FOXC1 was significantly reduced upon overexpression of miR-138-5p while luciferase reporter assay showed that FOXC1 was a direct target of miR-138-5p. In vivo, endogenous DHA by the mfat-1 transgene enhanced miR-138-5p expression and decreased FOXC1 expression. Furthermore, overexpression of FOXC1 reversed the inhibition in cell viability and invasion induced by RvD1 treatment. CONCLUSIONS: These data identified the RvD1/miR-138-5p/FOXC1 pathway as a novel mechanism by DHA and its metabolite, RvD1, and the potential of targeting such pathway as a therapeutic strategy in treating NSCLC.

Guidelines and recommendations on the clinical use of shear wave elastography for evaluating thyroid nodule1.

Ultrasound elastography has been introduced into clinical practice for a decade and arisen continuous increasing attention worldwide. Shear wave elastography (SWE) is a further extension of ultrasound elastography on the basis of strain elastography, providing a two-dimensional distribution map of tissue stiffness and quantitative measurement of the tissue stiffness in Young's modulus (kPa) and/or shear wave speed (m/s). The Society of Ultrasound in Medicine, Chinese Medical Association (CMA) has recently released a series of guidelines for the use of SWE, including the technique and principle of SWE, and use of SWE in liver fibrosis, breast, thyroid, and musculoskeletal system. Herein, a part of SWE in thyroid nodules is presented. In this guideline, the background, classification and technology of SWE, examination methods, diagnostic performance, prognosis evaluation, reproducibility, and limitations are discussed and recommendations are given. The recommendations are based on the published literatures with regard to SWE with different levels of evidence, particularly a mid-term result of the prospective multi-center clinical trial of SWE in thyroid, as well as the Society of Ultrasound in Medicine, CMA expert's consensus. The document provides an overall analysis of SWE in thyroid from clinical perspective, which aimed to provide recommendations to the clinicians with regard to the management of thyroid nodules by the assistance of SWE.

An Ω-3 fatty acid desaturase-expressing gene attenuates prostate cancer proliferation by cell cycle regulation.

Previous studies have reported that Ω-6 and Ω-3 fatty acids have opposing effects on cancer development. Consuming high levels of long-chain Ω-3 polyunsaturated fatty acids (PUFAs) has been shown to reduce prostate cancer risk and increase chemotherapy sensitivity. The sdd17 gene encodes an Ω-3 fatty acid desaturase, which converts arachidonic acid into eicosapentaenoic acid (EPA). However, little is known regarding the function of the sdd17 gene in tumor cells in vitro. In the present study, prostate cancer cells were infected with the msdd17 gene, which allowed the endogenous production of Ω-3 PUFAs. The cells that expressed the msdd17 gene had high levels of long-chain Ω-3 PUFAs compared with the control cells. Expression of the msdd17 gene significantly inhibited prostate cancer cell proliferation. EPA exposure and msdd17 gene transfection each induced G2 cell cycle arrest and reduced E2F transcription factor 1 expression in prostate cancer cells. These results suggest that msdd17 gene transfection suppressed prostate cancer cell proliferation and induced G2 cell cycle arrest.

Suppression of pancreatic ductal adenocarcinoma growth by intratumoral delivery of attenuated Salmonella typhimurium using a dual fluorescent live tracking system.

Pancreatic ductal adenocarcinoma (PDAC) has the poorest prognosis among all malignancies and is resistant to almost all current therapies. Attenuated Salmonella typhimurium strain VNP20009 has been deployed as powerful anticancer agent in a variety of animal cancer models, and previous phase 1 clinical trials have proven its safety profiles. However, thus far, little is known about its effect on PDAC. Here, we established CFPAC-1 cell lines expressing an mKate2 protein and thus emitting far-red fluorescence in the subsequent xenograft implant. VNP20009 strain was further engineered to carry a luciferase cDNA, which catalyzes the light-emitting reaction to allow the observation of salmonella distribution and accumulation within tumor with live imaging. Using such VNP20009 strain and intratumoral delivery, we could reduce the growth of pancreatic cancer by inducing apoptosis and severe necrosis in a dosage dependent manner. Consistent with this finding, intratumoral delivery of VNP20009 also increase caspase-3 activity and the expression of Bax protein. In summary, we revealed that VNP20009 is a promising bacterial agent for the treatment of PDAC, and that we have established a dual fluorescent imaging system as a valuable tool for noninvasive live imaging of solid tumor and engineered bacterial drug.