Oridonin attenuates liver ischemia-reperfusion injury by suppressing PKM2/NLRP3-mediated macrophage pyroptosis.

BACKGROUND: The NOD-like receptor protein 3 (NLRP3) mediated pyroptosis of macrophages is closely associated with liver ischemia reperfusion injury (IRI). As a covalent inhibitor of NLRP3, Oridonin (Ori), has strong anti-inflammasome effect, but its effect and mechanisms for liver IRI are still unknown. METHODS: Mice and liver macrophages were treated with Ori, respectively. Co-IP and LC-MS/MS analysis of the interaction between PKM2 and NLRP3 in macrophages. Liver damage was detected using H&E staining. Pyroptosis was detected by WB, TEM, and ELISA. RESULTS: Ori ameliorated liver macrophage pyroptosis and liver IRI. Mechanistically, Ori inhibited the interaction between pyruvate kinase M2 isoform (PKM2) and NLRP3 in hypoxia/reoxygenation（H/R）-induced macrophages, while the inhibition of PKM2/NLRP3 reduced liver macrophage pyroptosis and liver IRI. CONCLUSION: Ori exerted protective effects on liver IRI via suppressing PKM2/NLRP3-mediated liver macrophage pyroptosis, which might become a potential therapeutic target in the clinic.

Nanotargeted Cationic Lipid Microbubbles Carrying HSV-TK Gene Inhibit the Development of Subcutaneous Liver Tumor Model After HIFU Ablation.

OBJECTIVES: High-intensity focused ultrasound (HIFU) has been widely used in clinical settings and has achieved suitable results in the treatment of many cancerous or noncancerous diseases. However, in the treatment of liver cancer, because the tumor is located deep within the liver tissue, when ultrasound penetrates the tissue, it will inevitably produce sound energy attenuation. This attenuation limits the reliability of HIFU treatment, reduce the efficacy of HIFU, and increase the risk of tumor recurrence. METHODS: Cationic microbubbles (CMB) were successfully linked with GPC3 and HSV-TK plasmids, and targeted gene-carrying CMB were successfully constructed. Moreover, the gene-targeted cation microbubbles had suitable targeting and can specifically bind with liver cancer cells. RESULTS: The HSV-TK transfection efficiency was high and had a significant inhibitory effect on the proliferation and invasion of liver cancer cells. After the gene-carrying cation microbubbles entered the animal body, they had a great targeting effect in vivo. They transfected the target genes into liver cancer cells, and the HSV-TK/GCV system initiated cell death, demonstrating that these targeted microbubbles, enhanced HIFU treatment. CONCLUSIONS: Overall, CMB combined with a GPC3 antibody and HSV-TK plasmid can target residual subcutaneous liver tumor cells under the guidance of GPC3 antibody, and kill residual subcutaneous liver tumor cells under the action of ultrasound, thus enhancing the therapeutic effect of HIFU on liver cancer.

INKA2-AS1 Is a Potential Promising Prognostic-Related Biomarker and Correlated with Immune Infiltrates in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a malignancy with one of the worst prognoses. Long noncoding RNAs (lncRNAs) may be important in cancer development and may serve as new biomarkers for the diagnosis and treatment of various tumors, according to mounting research. The purpose of this study was to investigate the expression of INKA2-AS1 and clinical importance in HCC patients. The TCGA database was used to obtain the human tumor samples, while the TCGA and GTEx databases were used to gather the human normal samples. We screened differentially expressed genes (DEGs) between HCC and nontumor tissues. Investigations were made into the statistical significance and clinical significance of INKA2-AS1 expression. A single-sample gene set enrichment analysis (ssGSEA) was used to examine potential relationships between immune cell infiltration and INKA2-AS1 expression. In this investigation, we found that HCC specimens had considerably greater levels of INKA2-AS1 expression than nontumor specimens. When utilizing the TCGA datasets and the GTEx database, high INKA2-AS1 expression showed an AUC value for HCC of 0.817 (95% confidence interval: 0.779 to 0.855). Pan-cancer assays revealed that numerous tumor types had dysregulated levels of INKA2-AS1. Gender, histologic grade, and pathologic stage were all substantially correlated with high INKA2-AS1 expression. A survival study indicated that HCC patients with high INKA2-AS1 expression have shorter OS, DSS, and PFI than those with low INKA2-AS1 expression. Multivariate analysis indicated that INKA2-AS1 expression was an independent prognostic factor for OS of patients with HCC. According to immune analysis, the expression of INKA2-AS1 was favorably correlated with T helper cells, Th2 cells, macrophages, TFH, and NK CD56bright cells and negatively correlated with Th17 cells, pDC, cytotoxic cells, DC, Treg, Tgd, and Tcm. The results of this study collectively suggest that INKA2-AS1 has the potential to be a novel biomarker for predicting the prognosis of HCC patients as well as a significant immune response regulator in HCC.

[Evaluation of Extrathyroidal Extension of Papillary Thyroid Microcarcinoma With Three-Dimensional Tomographic Ultrasound Imaging].

Objective To evaluate extrathyroidal extension (ETE) in papillary thyroid microcarcinoma (PTMC) with three-dimensional tomographic ultrasound imaging (3D-TUI). Methods A total of 97 thyroid nodules of 79 patients with PTMC treated in PUMC Hospital from February 2016 to January 2018 were included in this study.Two ultrasound experts performed independent blinded assessment of the relationship between thyroid nodules and thyroid capsule by two-dimensional ultrasound (2D-US) and 3D-TUI.The results of 2D-US and 3D-TUI in evaluating ETE were compared with intraoperative findings and postoperative histological and pathological results. Results Among the 97 nodules,54 (55.7%) nodules had ETE.The diagnostic sensitivity (68.5% vs.37.0%;χ2=10.737,P=0.002),accuracy (74.5% vs.56.7%;χ2=6.686,P=0.015),and area under the receiver operating characteristic curve[0.761 (95%CI=0.677-0.845) vs.0.592 (95%CI=0.504-0.680);Z=3.500,P<0.001] of 3D-TUI were higher than those of 2D-US.However,3D-TUI and 2D-US showed no significant difference in the specificity (84.1% vs.81.4%;χ2=0.081,P=0.776),negative predictive value (67.9% vs.50.7%;χ2=3.645,P=0.066),or positive predictive value (84.1% vs.71.4%;χ2=1.663,P=0.240). Conclusion Compared with 2D-US,3D-TUI demonstrates increased diagnostic efficiency for ETE of PTMC.

Metal Phenolic Network-Integrated Multistage Nanosystem for Enhanced Drug Delivery to Solid Tumors.

Metal-phenolic networks (MPNs) are an emerging class of supramolecular surface modifiers with potential use in various fields including drug delivery. Here, the development of a unique MPN-integrated core-satellite nanosystem (CS-NS) is reported. The "core" component of CS-NS comprises a liposome loaded with EDTA (a metal ion chelator) in the aqueous core and DiR (a near-infrared photothermal transducer) in the bilayer. The "satellite" component comprises mesoporous silica nanoparticles (MSNs) encapsulating doxorubicin and is coated with a Cu2+ -tannic acid MPN. Liposomes and MSNs self-assemble into the CS-NS through adhesion mediated by the MPN. When irradiated with an 808 nm laser, CS-NS liberated the entrapped EDTA, leading to Cu2+ chelation and subsequent disassembly of the core-satellite nanostructure. Photo-conversion from the large assembly to the small constituent particles proceeded within 5 min. Light-triggered CS-NS disassembly enhanced the carrier and cargo penetration and accumulation in tumor spheroids in vitro and in orthotopic murine mammary tumors in vivo. CS-NS is long circulating in the blood and conferred improved survival outcomes to tumor-bearing mice treated with light, compared to controls. These results demonstrate an MPN-integrated multistage nanosystem for improved solid tumor treatment.

Nanobowl-Supported Liposomes Improve Drug Loading and Delivery.

Liposomal drug delivery for cancer therapy can be limited due to drug leakage in circulation. Here, we develop a new method to enhance the stability of actively loaded liposomal doxorubicin (DOX) through embedding a stiff nanobowl in the liposomal water cavity. Nanobowl-supported liposomal DOX (DOX@NbLipo) resists the influence of plasma protein and blood flow shear force to prevent drug leakage. This approach yields improved drug delivery to tumor sites and enhanced antitumor efficacy. Compared to alternative methods of modifying liposome surface and composition for stability, this approach designs a physical support for an all-aqueous nanoliposomal cavity. Nanobowl stabilization of liposomes is a simple and effective method to improve carrier stability and drug delivery.

Enhanced Drug Delivery by Nanoscale Integration of a Nitric Oxide Donor To Induce Tumor Collagen Depletion.

Delivery of therapeutics into the solid tumor microenvironment is a major challenge for cancer nanomedicine. Administration of certain exogenous enzymes which deplete tumor stromal components has been proposed as a method to improve drug delivery. Here we present a protein-free collagen depletion strategy for drug delivery into solid tumors, based on activating endogenous matrix metalloproteinases (MMP-1 and -2) using nitric oxide (NO). Mesoporous silica nanoparticles (MSN) were loaded with a chemotherapeutic agent, doxorubicin (DOX) as well as a NO donor ( S-nitrosothiol) to create DN@MSN. The loaded NO results in activation of MMPs which degrade collagen in the tumor extracellular matrix. Administration of DN@MSN resulted in enhanced tumor penetration of both the nanovehicle and cargo (DOX), leading to significantly improved antitumor efficacy with no overt toxicity observed.

MiRNAs and LncRNAs: Dual Roles in TGF-ß Signaling-Regulated Metastasis in Lung Cancer.

Lung cancer is one of the most malignant cancers around the world, with high morbidity and mortality. Metastasis is the leading cause of lung cancer deaths and treatment failure. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs), two groups of small non-coding RNAs (nc-RNAs), are confirmed to be lung cancer oncogenes or suppressors. Transforming growth factor-ß (TGF-ß) critically regulates lung cancer metastasis. In this review, we summarize the dual roles of miRNAs and lncRNAs in TGF-ß signaling-regulated lung cancer epithelial-mesenchymal transition (EMT), invasion, migration, stemness, and metastasis. In addition, lncRNAs, competing endogenous RNAs (ceRNAs), and circular RNAs (circRNAs) can act as miRNA sponges to suppress miRNAs, thereby mediating TGF-ß signaling-regulated lung cancer invasion, migration, and metastasis. Through this review, we hope to cast light on the regulatory mechanisms of miRNAs and lncRNAs in TGF-ß signaling-regulated lung cancer metastasis and provide new insights for lung cancer treatment.

Acetyl-3-Aminoethyl Salicylate Ameliorates Hepatic Ischemia/Reperfusion Injury and Liver Graft Survival Through a High-Mobility Group Box 1/Toll-Like Receptor 4-Dependent Mechanism.

In liver transplant cases, severe hepatic ischemia/reperfusion injury (HIRI) is a strong predictor of adverse liver graft and overall outcomes. During HIRI, high-mobility group box 1 (HMGB1) promotes hepatocellular death and proinflammatory cytokine secretion by toll-like receptor 4 (TLR4). Because salicylates inhibit HMGB1/TLR4 interaction, we hypothesized that salicylates may ameliorate HIRI-induced liver damage by inhibiting HMGB1/TLR4 axis activation. Using a murine model of HIRI, we found that the salicylate acetyl-3-aminoethyl salicylic acid (ac3AESA) reduced serum alanine aminotransferase and aspartate aminotransferase as well as Suzuki scores and apoptotic cell counts after HIRI. Ac3AESA also down-regulated hepatocellular HMGB1 and TLR4 expression, phosphorylated inhibitor of κBα, extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, cleaved caspase 3, and cleaved caspase 1 levels after HIRI. Ac3AESA reduced liver Kupffer cell transcription of proinflammatory mediators tumor necrosis factor α (TNF-α), interleukin (IL) 6, IL1ß, chemokine (C-X-C motif) ligand (CXCL) 1, CXCL2, and CXCL8 after HIRI. Ac3AESA also dose-dependently reduced in vitro release of Kupffer cell TNF-α. Employing a murine orthotopic liver transplantation model, we found daily ac3AESA administration up to day 10 after transplant improved liver graft survival, suppressed allograft damage, and down-regulated HMGB1/TLR4 signaling. These benefits to survival and allograft health were maintained for cold ischemia times of 12 and 18 hours. Notably, TLR4 knockout eliminated all foregoing ac3AESA-induced effects. In conclusion, ac3AESA partially rescues the negative effects of HIRI and prolongs liver graft survival in a TLR4-dependent manner.

Ultrasonographic Multimodality Diagnostic Model of Thyroid Nodules.

The aim of this study was to identify independent risk factors for thyroid cancer, establish an ultrasonographic multimodality diagnostic model for thyroid nodules, and explore the diagnostic value of the model. From November 2011 to February 2015, 307 patients with a total of 367 thyroid nodules underwent conventional ultrasound, contrast-enhanced ultrasound (CEUS), and ultrasound elastography examinations before surgery. A binary logistic regression analysis was performed to identify independent risk factors for thyroid cancer and to establish a multimodality diagnostic model for thyroid nodules. The diagnostic performance of conventional ultrasound, CEUS, ultrasound elastography, and the multimodality diagnostic model was assessed and compared. The following seven independent risk factors were included in the logistic regression models: age, irregular shape, hypoechoic pattern, marked hypoechoic pattern, irregular blood flow distribution, heterogeneous enhancement, and an elastic score of 3/4. The multimodality diagnostic model had a diagnostic accuracy of 86.9%, with a sensitivity of 93.5% and a specificity of 77.3%. The multimodality diagnostic model improved the diagnostic accuracy compared with that of conventional ultrasound, CEUS, and ultrasound elastography. Independent risk factors for thyroid cancer included age, irregular shape, hypoechoic pattern, marked hypoechoic pattern, irregular blood flow distribution, heterogeneous enhancement, and an elastic score of 3/4. The multimodality diagnostic model was demonstrated to be effective in the diagnosis of thyroid nodules.

Cdc42: A Novel Regulator of Insulin Secretion and Diabetes-Associated Diseases.

Cdc42, a member of the Rho GTPases family, is involved in the regulation of several cellular functions including cell cycle progression, survival, transcription, actin cytoskeleton organization and membrane trafficking. Diabetes is a chronic and metabolic disease, characterized as glycometabolism disorder induced by insulin deficiency related to ß cell dysfunction and peripheral insulin resistance (IR). Diabetes could cause many complications including diabetic nephropathy (DN), diabetic retinopathy and diabetic foot. Furthermore, hyperglycemia can promote tumor progression and increase the risk of malignant cancers. In this review, we summarized the regulation of Cdc42 in insulin secretion and diabetes-associated diseases. Organized researches indicate that Cdc42 is a crucial member during the progression of diabetes, and Cdc42 not only participates in the process of insulin synthesis but also regulates the insulin granule mobilization and cell membrane exocytosis via activating a series of downstream factors. Besides, several studies have demonstrated Cdc42 as participating in the pathogenesis of IR and DN and even contributing to promote cancer cell proliferation, survival, invasion, migration, and metastasis under hyperglycemia. Through the current review, we hope to cast light on the mechanism of Cdc42 in diabetes and associated diseases and provide new ideas for clinical diagnosis, treatment, and prevention.

[Association of Body Mass Index and Risk Stratification of Thyroid Nodules in a Multi-center Healthy Population].

Objective To investigate the relationship between body mass index(BMI)and risk levels of thyroid nodules in a multi-center healthy population. Methods A total of 6070 subjects were enrolled from five medical physical examination centers in China from January 2015 to December 2017. All the participants'general information and parameters were recorded. Thyroid nodules were detected by color Doppler ultrasonography. All ultrasound doctors received uniform training before study. Results Among all the subjects,5773(95.1%;with 4274 nodules identified in 2833 subjects)were from northern China and 297(4.9%,with 183 nodules identified in 158 subjects)from central China(χ2=1.923,P=0.092). The nodules were single in 1479 of 2991 subjects(49.4%)and multiple in 1512 subjects(50.6%). Nodules larger than 1 cm accounted for 13.3% and nodules smaller than 1 cm accounted for 86.7%. Compared with the non-thyroid nodule group,the thyroid nodule group had significantly more women(χ2=156.36,P=0.000),older age(t=-18.768,P=0.000),and higher fasting blood glucose(FBG) level(t=-3.808,P=0.000). Among all the nodules,the prevalence rates of benign,very-low-risk,low-risk,moderate risk,and high risk were 4.5%,6.6%,85.0%,0.1%,and 3.7%,respectively,according to the ATA guidelines. Notably,there were 4291 nodules at moderate or lower risks and 166 nodules at high risk. Compared with the former,patients with high-risk nodules had significantly lower BMI(χ2=25.161,P=0.000)and high FBG(t=3.357,P=0.000). Multivariate non-conditional Logistic regression showed low BMI(OR=2.900,95%CI:1.461-5.783,P=0.002)and high FBG level(OR=0.803,95%CI:0.675-0.955,P=0.013)were independent risk factors for high-risk nodules. Compared with subjects with normal weight or obese populations,subjects with low BMI had significantly higher detection rate of high-risk nodules(χ2=25.16,P=0.000). In ≥55 year-old group,significantly more high-risk nodules were detected in low BMI group(χ2=44.868,P=0.000). Conclusion Low weight is associated with high-risk thyroid nodules among people ≥55 years old.

Synthesis and biological evaluation of 173-dicarboxylethyl-pyropheophorbide-a amide derivatives for photodynamic therapy.

Three novel 173-dicarboxylethyl-pyropheophorbide-a amide derivatives as photosensitizers for photodynamic therapy (PDT) were synthesized from pyropheophorbide-a (Ppa). Their photophysical and photochemical properties, intracellular localization, photocytotoxicity in vitro and in vivo were investigated. All target compounds exhibited low cytotoxicity in the dark and remarkable photocytotoxicity against human esophageal cancer cells. Among them, 1a showed highest singlet oxygen quantum yield. Upon light activation, 1a exhibited significant photocytotoxicity. After PDT treatment, the growth of Eca-109 tumor in nude mice was significantly inhibited. Therefore, 1a is a powerful and promising antitumor photosensitizer for PDT.

Interleukin-33: Its Emerging Role in Allergic Diseases.

Allergic diseases, which include asthma, allergic rhinitis (AR), chronic rhinosinusitis (CRS), atopic dermatitis (AD), food allergy (FA), allergic keratoconjunctivitis, seriously affect the quality of life of people all over the world. Recently, interleukin-33 (IL-33) has been found to play an important role in these refractory disorders, mainly by inducing T helper (Th) 2 immune responses. This article reviews the mobilization and biological function of IL-33 in allergic disorders, providing novel insights for addressing these hypersensitive conditions.

Diagnostic Value of Elastography for Thyroid Nodules in Hashimoto's Thyroiditis.

Objective To evaluate the diagnostic performance of elastography in the diagnosis of thyroid nodules in the context of Hashimoto's thyroiditis(HT). Methods The study evaluated 43 thyroid nodules by conventional ultrasound (CU) and elastography in 38 patients co-existed with HT who were referred for operation. The patients underwent CU and elastography before operation. The sensitivity,specificity,positive and negative predictive values,and accuracy for CU,elastography,and combination of these two techniques were assessed by using histopathological results as the gold standard. Results Among these 43 thyroid nodules,pathology confirmed 29 (67.4%) malignant nodules and 14 (32.6%) benign ones. There were statistically significant differences between malignant and benign groups in features such as solid shape (96.6% vs. 64.0%;OR:15.6,95%CI:1.600-151.262,P=0.004),irregularity (90.0% vs. 42.9%;OR:11.6,95%CI:2.341-57.032,P=0.001),taller than wide shape (72.0% vs. 21.4%;OR:9.6,95% CI:2.117-43.753,P=0.002),microcalcification (69% vs. 28.6%;OR:5.6,95% CI:1.368-22.556,P=0.012) and irregular blood flow (90.0% vs. 28.6%;OR:17.3,95%CI:3.186-94.290,P=0.000). The diagnostic performance of elastography and CU was as follows:sensitivity (86.2 % vs.96.6%),specificity (71.4% vs.42.9%),positive predictive value (86.2% vs.77.8%),negative predictive value (71.4% vs.85.7%),and accuracy (81.4% vs.79.0%). The combination of these two techniques had a sensitivity of 93.1%,a specificity of 71.4%,a positive predictive value of 87.1%,a negative predictive value of 83.3%,and an accuracy of 86.0%. Conclusions Elastography has a higher specificity in the diagnosis of thyroid nodules in HT,while its sensitivity is slightly lower than that of CU. Combination of these two techniques can increase the specificity and accuracy.

Synthesis and evaluation of new 5-aminolevulinic acid derivatives as prodrugs of protoporphyrin for photodynamic therapy.

Protoporphyrin IX (PpIX) is used as a photosensitizer in the photodynamic diagnosis (PDD) and photodynamic therapy (PDT) of cancer and is synthesized intracellularly from 5-aminolevulinic acid (5-ALA) precursors. Thirteen novel 5-ALA derivatives were designed and synthesized appropriately with tailored hydrophilicity and lipophilicity. The generation of PpIX was detected and their antitumor activity in vitro and in vivo was also investigated. It was shown that compounds 9b-c, 11b-c and 13a displayed a characteristic long wavelength absorption peak at 593 nm after 5 h incubation in mice fibrosarcoma S180 cells. After being exposed to 600 nm laser light irradiation, these compounds can inhibit cell proliferation in S180 cells in vitro. The growth of S180 cell tumors in Kunming mice was significantly inhibited by these compounds in vivo. Among these compounds, 13a has low dark toxicity and high phototoxicity, which makes it an effective and promising prodrug for PDT.

Comparison of Ultrasound Features of Primary Metastatic Papillary Thyroid Carcinoma and Recurrent/Persistent Metastatic Cervical Lymph Nodes.

Objective To explore the ultrasound features and levels of cervical lymph node metastases in primary and recurrent/persistent papillary thyroid cancer (PTC).Methods We retrospectively analyzed the clinical data of 2181 patients who underwent cervical lymph nodes dissection for PTC from January 1st 2015 to January 1st 2016.Totally 418 PTC patients (with 622 lymph nodes) who met the inclusion criteria entered the final analysis.Patients who had not received any prior thyroid treatment (surgery with or without radioactive iodine) were categorized as the primary group (352 patients with 527 metastatic lymph nodes),and patients who had received prior treatment (thyroidectomy with or without radioactive iodine) for PTC were categorized as recurrent/persistent group (66 patients with 95 metastatic lymph nodes).Pathological results from lymph node dissections were used as the gold standards by means of level-to-level analysis.Results The mean of the minimum axis diameter of the lymph nodes in the primary group was (6.7±3.6)mm,and that of the recurrent/persistent group was (6.6±3.1)mm (U=0.180,P=0.857).The proportion of metastasis in the central area of primary group was 40.0%,which was significantly higher than that in the recurrent/persistent group (12.6%);the proportion of metastasis in the lateral area was 60.6% in the primary group,which was significantly lower than that in the recurrent/persistent group (87.4%)(χ2=26.288,P<0.001).In lateral metastatic lymph nodes,Ⅲ level was the most common place in both groups.Level Ⅴ metastatic lymph was rare in both primary group and recurrent/persistent group.Calcifications (63.1% vs. 48.2%;χ2=7.207,P=0.007) and peripheral vascularity (81.1% vs. 59.4%;χ2= 16.147, P<0.001) were more common in the recurrent/persistent group.The round shape,absence of an echogenic hilum,hyperechogenicity,and cystic aspects were not significantly different between these two groups (all P>0.05).Conclusions Primary metastatic lymph nodes often occur in the central area of lymph nodes,while lateral metastatic lymph nodes are more common in recurrent/persistent PTC.For metastatic lymph nodes,calcifications and peripheral vascularity are more common in recurrent/persistent PTC.

[Anti-tumor effect and impact on tumor immune microenvironment of tumor-targeted Salmonella VNP20009].

Salmonella is a gram-negative bacterium that has an ability of tumor-targeting growth and proliferation. Attenuated Salmonella VNP20009 is a virulence genes-knockout bacterial strain based on Salmonella typhimurium, and it has an advantage of good therapeutic effect and low toxicity. One of the mechanisms of anti-tumor effect of VNP20009 is the induction of inflammatory reaction within tumor tissues. We used B16F10 melanoma model to investigate the mechanism of the anti-tumor effect of VNP20009. VNP20009 treatment effectively inhibited tumor growth and promoted the apoptosis and necrosis of tumor cells. VNP20009 increased the accumulation or infiltration of CD8(+) T cells and CD11b(+) monocytes within tumor tissue by raising the level of immune response and thus, induce the production of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) to kill tumor cells by breaking the immuno-evasion barrier in the tumor microenvironment.

Antitumor activity of photodynamic therapy with a chlorin derivative in vitro and in vivo.

Chlorin derivatives are promising photosensitive agents for photodynamic therapy (PDT) of tumors. The aim of the current study is to investigate the PDT therapeutic effects of a novel chlorin-based photosensitizer, meso-tetra[3-(N,N-diethyl)aminomethyl-4-methoxy]phenyl chlorin (TMPC) for gliomas in vitro and in vivo. Physicochemical characteristics of TMPC were recorded by ultraviolet visible spectrophotometer and fluorescence spectrometer. The rate of singlet oxygen generation of TMPC upon photo-excitation was detected by using 1,3-diphenylisobenzofuran (DPBF). The accumulation of TMPC in gliomas U87 MG cells was measured by fluorescence spectrometer. The efficiency of TMPC-PDT in vitro was analyzed by MTT assay and clonogenic assay. The biodistribution and clearance of TMPC were determined by fluorescence measuring. Human gliomas U87 MG tumor-bearing mice model was used to evaluate the antitumor effects of TMPC-PDT. TMPC shows a singlet oxygen generation rate of 0.05 and displays a characteristic long wavelength absorption peak at 653 nm (ε = 15,400). The accumulation of TMPC increased with the increase of incubation time. In vitro, PDT using TMPC and laser showed laser dose- and concentration-dependent cytotoxicity to U87 MG cells. In U87 MG tumor-bearing mice, TMPC-PDT significantly reduced the growth of the tumors. Both in vitro and in vivo, TMPC showed little dark toxicity. In vitro and in vivo studies, it found that TMPC has excellent antitumor activities. It suggests that TMPC is a potential photosensitizer of photodynamic therapy for cancer.

The association between Salt-inducible kinase 2 (SIK2) and gamma isoform of the regulatory subunit B55 of PP2A (B55gamma) contributes to the survival of glioma cells under glucose depletion through inhibiting the phosphorylation of S6K.

BACKGROUND: PPP2R2C encodes a gamma isoform of the regulatory subunit B55 subfamily consisting PP2A heterotrimeric with A and C subunits. Currently, the precise functions of B55gamma in cancer are still under investigating. In this project, we reported a novel function of B55gamma in the regulation of glucose metabolism in Glioma cells. METHODS: Western blot and immunoprecipitation were performed to determine protein expression and interaction. Cell viability was measured by Typan Blue staining and direct cell counting using hematocytometer. siRNA technology was used to down regulate protein expression. RESULTS: Glucose uptake and lactate product were suppressed by overexpression of B55gamma in Glioma cells. In addition, cancer cells with larger amount of B55gamma showed higher survival advantages in response to glucose starvation through the dephosphorylation of S6K. From proteomic analysis, we found B55gamma binds with and up regulates SIK2 through the stabilization of SIK2 protein which is required for the B55gamma-mediated suppression of S6K pathway. Knocking down of SIK2 in B55gamma over expressing cells recovered the phosphorylation of S6K. CONCLUSION: In summary, our project will provide novel insight into the design and development of therapeutic strategies to target the B55gamma-mediated glucose metabolism for the treatment of human brain tumor patients.