Enhanced mechanical properties and antibacterial activities of chitosan films through incorporating zein-gallic acid conjugate stabilized cinnamon essential oil Pickering emulsion.

In this study, zein-gallic acid covalent complex prepared by alkali treatment was utilized as an emulsifier to stabilize cinnamon essential oil (CEO) Pickering emulsion, and the chitosan-based (CZGE) films loaded with CEO Pickering emulsion were prepared by blending. The influences of different contents of CEO Pickering emulsion on the physical properties and biological activities of CZGE films were investigated. The results showed that Pickering emulsion had good compatibility with chitosan matrix and enhanced the interaction between film-forming matrix polymer. In addition, incorporating with CEO Pickering emulsion (15 %, v/v) significantly improved the mechanical and barrier properties of the films, and also enhanced the light transmittance and thermal stability of the films. Furthermore, the loading of emulsion also improved the antioxidant activities of the films and led to the formation of high antimicrobial property against food pathogens, and the slow-release behavior of CEO could effectively extend the biological activity of the films. These results suggested that Pickering emulsion has potential as a loading system and a plasticizer in active packaging, and the feasibility of CZGE film in food packaging.

Oxidized phospholipids facilitate calcific aortic valve disease by elevating ATF4 through the PERK/eIF2α axis.

In this study we sought to analyze the critical role of oxidized phospholipid (OxPL) in the progression of calcific aortic valve disease (CAVD) with the involvement of activating transcription factor 4 (ATF4). Differentially expressed genes related to CAVD were identified using bioinformatics analysis. Expression of ATF4 was examined in mouse models of aortic valve calcification (AVC) induced by the high cholesterol (HC) diet. Valvular interstitial cells (VICs) were then isolated from mouse non-calcified valve tissues, induced by osteogenic induction medium (OIM) and co-cultured with OxPAPC-stimulated macrophages. The effect of OxPLs regulating ATF4 on the macrophage polarization and osteogenic differentiation of VICs was examined with gain- and loss-of-function experiments in VICs and in vivo. In aortic valve tissues and OIM-induced VICs, ATF4 was highly expressed. ATF4 knockdown alleviated the osteogenic differentiation of VICs, as evidenced by reduced expression of bone morphogenetic protein-2 (BMP2), osteopontin (OPN), and osteocalcin. In addition, knockdown of ATF4 arrested the AVC in vivo. Meanwhile, OxPL promoted M1 polarization of macrophages and mediated osteogenic differentiation of VICs. Furthermore, OxPL up-regulated ATF4 expression through protein kinase R-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2 subunit alpha (eIF2α) pathway. In conclusion, OxPL can potentially up-regulate the expression of ATF4, inducing macrophages polarized to M1 phenotype, osteogenic differentiation of VICs and AVC, thus accelerating the progression of CAVD.

Insulin-Like Growth Factor 1 and Risk of Cardiovascular Disease: Results From the UK Biobank Cohort Study.

CONTEXT: Relationships between insulin-like growth factor 1 (IGF-1) levels and cardiovascular disease (CVD) in the general population remain unclear. OBJECTIVE: This study aims to investigate the association of circulating IGF-1 concentrations with CVD from a population-based cohort study. METHODS: A total of 394 082 participants without CVD and cancer at baseline from UK Biobank were included with measurements of serum IGF-1 at baseline. Main outcomes were incidence of CVD, including CVD mortality, coronary heart disease (CHD), myocardial infarction (MI), heart failure (HF), and stroke. RESULTS: Over a median 11.6 years of follow-up, UK Biobank documented 35 803 incident CVD cases, including 4231 from CVD-related death, 27 051 from CHD, 10 014 from MI, 7661 from HF, and 6802 from stroke. Dose-response analysis showed a U-shaped relationship between IGF-1 levels and cardiovascular events. Compared with the third quintile of IGF-1, the lowest category of IGF-1 was associated with increased risk of CVD (hazard ratio 1.128; 95% CI, 1.093 to 1.164), CVD mortality (1.294; 1.181 to 1.418), CHD (1.118; 1.078 to 1.159), MI (1.071; 1.008 to 1.139), HF (1.185; 1.107 to 1.268), and stroke (1.149, 1.070 to 1.235); also, the highest category was associated with increased risk of CVD (1.056; 1.020 to 1.094), CVD mortality (1.111; 1.000 to 1.236), CHD (1.070; 1.028 to 1.114), MI (1.111; 1.041 to 1.187) and HF (1.098; 1.015 to 1.188) after multivariable adjustment. CONCLUSION: This study indicates that both low and high levels of circulating IGF-1 are associated with increased risk of CVD in general population. These results highlight the importance of monitoring IGF-1 status on cardiovascular health.

Associations of fish oil supplementation with incident dementia: Evidence from the UK Biobank cohort study.

Background: Although numerous studies have investigated the association of dietary intake of omega-3 fatty acids with cognitive function and the risks of dementia, the relationship between fish oil supplementation and incident dementia in a large population-based cohort study has not yet well studied. Materials and methods: A total of 211,094 community-dwelling older persons over 60 years from the UK Biobank cohorts enrolled between 2006 and 2010 that reported regularly taking fish oil and had no dementia at baseline, was included in the present study. All participants completed an electronic questionnaire regarding habitual use of supplements including fish oil. Results: Overall, 83,283 (39.5%) participants reported regularly taking fish oil at baseline. Of 211,094 participants with the median age was 64.1 years, 5,274 participants developed dementia events during a median follow-up of 11.7 years, with 3,290 individuals derived from fish oil non-users. In the multivariable adjusted models, the adjusted hazard ratios (HRs) associated with fish oil supplementation for all-cause dementia, vascular dementia, frontotemporal dementia, and other dementia were 0.91 [CI = 0.84-0.97], 0.83 [CI = 0.71-0.97], 0.43 [CI = 0.26-0.72], 0.90 [CI = 0.82-0.98], respectively (all P < 0.05). However, no significant association between fish oil supplementation and Alzheimer's disease was found (HR = 1.00 [CI = 0.89-1.12], P = 0.977). In the subgroup analyses, the associations between use of fish oil and the risk of all-cause dementia (P for interaction = 0.007) and vascular dementia were stronger among men (P for interaction = 0.026). Conclusion: Among older adults, regular fish oil supplementation was significantly associated with a lower risks of incident all-cause dementia, as well as vascular dementia, frontotemporal dementia and other dementia but not Alzheimer's disease. These findings support that habitual use of fish oils may be beneficial for the prevention of dementia in clinical practice.

Isolation, Characterization, and Depolymerization of l-Cysteine Substituted Eucalyptus Lignin.

Lignin condensation reactions are hard to avoid or control during separation, which is a deterrent to lignin isolation and post-conversation, especially for the full utilization of lignocelluloses. Selective protection of ß-aryl ether linkages in the isolation process is crucial to lignin valorization. Herein, a two-step acid/alkali separation method assisted with l-cysteine for eucalyptus lignin separation is developed, and the isolated l-cysteine lignins (LCLs) are comprehensively characterized by 2D NMR, 31P NMR, thioacidolysis, etc. Compared to the two-step control treatment, a much higher ß-O-4 content is preserved without reducing the separation efficiency assisted by l-cysteine, which is also significantly higher than alkali lignin and kraft lignin. The results of hydrogenolysis show that LCLs generate a much higher monomer yield than that of control sample. Structural analysis of LCLs suggests that lignin condensation reaction, to some extent, is suppressed by adding l-cysteine during the two-step acid/alkali separation. Further, mechanistic studies using dimeric model compound reveals that l-cysteine may be the α-carbon protective agent in the two-step separation. The role of l-cysteine in the two-step lignin isolation method provides novel insights to the selective fractionation of lignin from biomass, especially for the full valorization of lignocellulosic biomass.

Prognostic signature of esophageal adenocarcinoma based on pyroptosis-related genes.

BACKGROUND: The role of pyroptosis-related genes (PRGs) in esophageal adenocarcinoma (EAC) remains unknown. METHODS: In this study, the first PRGs prognostic signature (PPS) of EAC was constructed based on the results of multivariate stepwise Cox regression analysis. Based on 1,047 samples of EAC and normal esophagus (NE), differentially expressed PRGs were selected for the establishment of the PPS. The discrimination effect of this PPS was detected by receiver operating characteristic curves, and the prognosis value of this PPS was determined through Cox regression analysis and Kaplan-Meier curves. Net benefits of the EAC patients from the nomogram (constructed based on the PPS and some clinical parameters) were assessed via decision curve analysis. The potential molecular mechanism of the PPS in EAC was explored via gene set enrichment analysis. The ability of PPS to distinguish EAC and NE was evaluated based on the results of summary receiver operating characteristic curves. RESULTS: The significant prognostic value of PPS can be observed at all of the training cohort, test cohort, and validation cohort, such as its independent risk role in the prognosis of the EAC patients (hazard ratio > 0; 95% CI not including 0). The positive net benefits of the nomogram for the EAC patients can be detected via decision curve analysis, and the potential molecular mechanism of the PPS in EAC is likely related to cell pyroptosis. Last, some of the PRGs (particularly CASP5) included in this PPS specifically support its feasibility for identifying EAC (area under the curves > 0.7). CONCLUSIONS: The construction of this PPS in EAC enhances the present understanding of the relationship between PRGs and EAC, thus representing a novel approach to the clinical identification and management of EAC based on PRGs.

Synergistic Effect of La and TiB2 Particles on Grain Refinement in Aluminum Alloy.

Synergistic effect of TiB2 (in form of Al-5Ti-1B) and La on grain refining results in Al-2Cu alloy was investigated. α-Al grains are significantly refined by Al-5Ti-1B. When trace La is added to the melt, further refinement is exhibited. Average grain size and nucleation undercooling of α-Al reduce first and then almost remain unchanged with La addition. Satisfactory grain refining result achieves when La addition level reaches 600 ppm. When more than 600 ppm La is added to the melt, La-rich particles form and the effect of solute La left in matrix on the microstructure almost no longer changes. Theoretical calculation results demonstrate that solute La segregates to Al melt/TiB2 particles interface along with Ti and Cu prior to α-Al nucleation and the synergistic effect of La and TiB2 particles on grain refinement mainly attributes to the enhancement in the potency of TiB2 particles to heterogeneously nucleate α-Al by trace La addition.

BCAT1: A risk factor in multiple cancers based on a pan-cancer analysis.

BACKGROUND: Although branched chain amino acid transaminase 1 (BCAT1) has been identified to play an essential role in multiple tumors, no studies on its role in pan-cancer have been consulted before. METHODS: The study comprehensively analyzes the expression, potential mechanisms, and clinical significance of BCAT1 in pan-cancer through utilizing 16,847 samples, providing novel clues for the treatment of cancers. A Kruskal-Wallis test and the Wilcoxon rank-sum and signed-rank tests were applied to investigate diverse BCAT1 expression between various groups (e.g., cancer tissues versus normal tissues). Spearman's rank correlation coefficient was used in all correlation analyses in the study. Cox analyses and Kaplan-Meier curves were utilized to identify the prognosis significance of BCAT1 expression in cancers. The significance of BCAT1 expression in differentiating cancer and non-cancer tissues was explored via the area under the receiver operating characteristic curves (AUC). RESULTS: The differential expression of BCAT1 was detected in various cancers (p < 0.05), which is relevant to some DNA methyltransferases expression. BCAT1 expression was associated with mismatch repair gene expression, immune checkpoint inhibitors expression, microsatellite instability, and tumor mutational burden in some cancers, indicating its potential in immunotherapy. BCAT1 expression showed prognosis significance and played a risk role in multiple cancers (hazard ratio > 0, p < 0.05). BCAT1 expression also demonstrated conspicuous ability to distinguish some cancers tissues from their normal tissues (AUC > 0.7), indicating its potential to detect cancers. Further analyses on head and neck squamous cell carcinoma certified upregulated BCAT1 expression at both mRNA and protein levels in this disease based on in-house tissue microarrays and multicenter datasets. CONCLUSIONS: For the first time, the research comprehensively demonstrates the overexpression of BCAT1 in pan-cancer, which improves the understanding of the pathogenesis of BCAT1 in pan-cancer. Upregulated BCAT1 expression represented a poor prognosis for cancers patients, and it serves as a potential marker for cancer immunotherapy.

Downregulation of miR-125b-5p and Its Prospective Molecular Mechanism in Lung Squamous Cell Carcinoma.

Background: To explore the clinical significance of miR-125b-5p and its potential mechanisms in lung squamous cell carcinoma (LUSC). Materials and Methods: An integrated analysis of data from in-house quantitative real-time polymerase chain reaction (qRT-PCR), microRNA-sequencing, and microarray assays to appraise the expression level of miR-125b-5p in LUSC tissues compared to adjacent noncancerous controls. The authors identified the candidate targets of miR-125b-5p and conducted functional analysis using computational biology strategies from gene ontology, the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, disease ontology (DO), and protein-protein interaction (PPI) network analyses to investigate the prospective mechanisms. Results: According to qRT-PCR results, the expression level of miR-125b-5p was markedly decreased in LUSC tissues compared to noncancerous control tissues. Receiver operating characteristic and summary receiver operating characteristic analyses showed that miR-125b-5p had good specificity and sensitivity for distinguishing LUSC tissue from noncancerous lung tissue. The standard mean difference revealed that men and women with lower expression levels of miR-125b-5p may have a higher risk for LUSC. KEGG analysis and DO analysis intimated that target genes were evidently enriched in pyrimidine metabolism and pancreatic carcinoma. The PPI network of the top assembled KEGG pathway indicated that RRM2, UMPS, UCK2, and CTPS1 were regarded as crucial target genes for miR-125b-5p, and RRM2 was eventually deemed a key target. Conclusions: The authors' findings implicate a low expression level of miR-125b-5p in LUSC. A tumor-suppressive role of miR-125b-5p is proposed, based on its effects on LUSC tumor growth, clinical stage progression, and lymph node metastasis.

Laryngeal Squamous Cell Carcinoma: Clinical Significance and Potential Mechanism of Cell Division Cycle 45.

Background: Cell division cycle 45 (CDC45) plays an important role in the occurrence and development of numerous carcinomas, but its effect in laryngeal squamous cell carcinoma (LSCC) remains unclear. Materials and Methods: The messenger RNA and protein expression levels of CDC45 in LSCC were evaluated with a t test and the standard mean difference (SMD). The ability of CDC45 expression to distinguish the LSCC was assessed through receiver operating characteristic (ROC) curves. Gene set enrichment analysis (GSEA), protein-protein interaction, public databases, and online tools were used to explore the potential molecular mechanism of CDC45 in LSCC. Results: A high expression of CDC45 was identified in LSCC (SMD = 2.61, 95% confidence interval [1.62-3.61]). Through ROC curves, the expression of CDC45 makes it feasible to distinguish the LSCC group from the non-LSCC counterpart. CDC45 was relevant to the progression-free interval of LSCC patients (log-rank p = 0.03). GSEAs show that CDC45 is related to the cell cycle. CDC45, CDC6, KIF2C, and AURKB were identified as hub genes of LSCC. E2F1 may be the regulatory transcription factor of CDC45. Conclusions: High expression of CDC45 likely demonstrates carcinogenic effects in LSCC, and CDC45 is a potential target in screening and treatment of LSCC.

LPCAT1 overexpression promotes the progression of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) remains one of the most common malignant neoplasms. Lysophosphatidylcholine acyltransferase 1 (LPCAT1) plays a key role in the lipid remodelling and is correlated with various neoplasms. Nonetheless, the biological functions and molecular mechanisms of LPCAT1 underlying HCC remain obscure. METHODS: In the present study, we investigated the role of LPCAT1 in the progression of HCC. In-house RT-qPCR, tissue microarrays, and immunohistochemistry were performed to detect the expression levels and the clinical value of LPCAT1 in HCC. External datasets were downloaded to confirm the results. Proliferation, migration, invasiveness, cell cycle, and apoptosis assays were conducted to reveal the biological effects LPCAT1 has on SMMC-7721 and Huh7 cells. HCC differentially expressed genes and LPCAT1 co-expressed genes were identified to explore the molecular mechanisms underlying HCC progression. RESULTS: LPCAT1 showed upregulated expression in 3715 HCC specimens as opposed to 3105 non-tumour specimens. Additionally, LPCAT1 might be an independent prognostic factor for HCC. LPCAT1-knockout hampered cellular proliferation, migration, and metastasis in SMMC-7721 and Huh7 cells. More importantly, the cell cycle and chemical carcinogenesis were the two most enriched signalling pathways. CONCLUSIONS: The present study demonstrated that increased LPCAT1 correlated with poor prognosis in HCC patients and fuelled HCC progression by promoting cellular growth, migration, and metastasis.

Upregulation of microRNA miR-141-3p and its prospective targets in endometrial carcinoma: a comprehensive study.

The clinicopathological value of microRNA-141-3p (miR-141-3p) and its prospective target genes in endometrial carcinoma (EC) remains unclear. The present study determined the expression level of miR-141-3p in EC via quantitative real-time PCR (RT-qPCR). RT-qPCR showed a markedly higher expression level of miR-141-3p in EC tissues than in non-EC endometrium tissues (P < 0.0001). The microarray and miRNA-seq data revealed upregulation of miR-141-3p. Integrated analysis based on 675 cases of EC and 63 controls gave a standardized mean difference of 1.737, confirmed the upregulation of miR-141-3p. The Kaplan-Meier survival curve showed that a higher expression of miR-141-3p positively corelated with a poorer prognosis. Combining the predicted targets and downregulated genes in EC, we obtained 271 target genes for miR-141-3p in EC. Two potential targets, PPP1R12A and PPP1R12B, were downregulated at both the mRNA and protein levels. This study indicates that the overexpression of miR-141-3p may play an important part in the carcinogenesis of EC. The overexpression of miR-141-3p may be a risk factor for the prognosis of patients with EC.

Integrated expression analysis revealed RUNX2 upregulation in lung squamous cell carcinoma tissues.

This study aimed to investigate the clinicopathological significance and prospective molecular mechanism of RUNX family transcription factor 2 (RUNX2) in lung squamous cell carcinoma (LUSC). The authors used immunohistochemistry (IHC), RNA-seq, and microarray data from multi-platforms to conduct a comprehensive analysis of the clinicopathological significance and molecular mechanism of RUNX2 in the occurrence and development of LUSC. RUNX2 expression was significantly higher in 16 LUSC tissues than in paired non-cancerous tissues detected by IHC (P < 0.05). RNA-seq data from the combination of TCGA and genotype-tissue expression (GTEx) revealed significantly higher expression of RUNX2 in 502 LUSC samples than in 476 non-cancer samples. The expression of RUNX2 protein was also significantly higher in pathologic T3-T4 than in T1-T2 samples (P = 0.031). The pooled standardised mean difference (SMD) for RUNX2 was 0.87 (95% CI, 0.58-1.16), including 29 microarrays from GEO and one from ArrayExpress. The co-expression network of RUNX2 revealed complicated connections between RUNX2 and 45 co-expressed genes, which were significantly clustered in pathways including ECM-receptor interaction, focal adhesion, protein digestion and absorption, human papillomavirus infection and PI3K-Akt signalling pathway. Overexpression of RUNX2 plays an essential role in the clinical progression of LUSC.

Clinical significance of transcription factor RUNX2 in lung adenocarcinoma and its latent transcriptional regulating mechanism.

RUNX family transcription factor 2 (RUNX2) overexpression has been found in various human malignancies. However, the expression levels of RUNX2 mRNA and protein in lung adenocarcinoma (LUAD) were not investigated. This study aims to thoroughly analysis the expression level and potential mechanisms of RUNX2 mRNA in LUAD. We applied in-house immunohistochemistry, high-throughput RNA-sequencing, and gene microarrays to comprehensively investigate the expression level of RUNX2 in LUAD. A pool standard mean difference (SMD) and summary receiver operating characteristic curves (SROC) were calculated to assess the integrated expression value of RUNX2 in LUAD. The hazard ratios (HRs) were integrated to evaluate the overall prognostic effect of RUNX2 on the LUAD patients. The differentially expressed genes (DEGs) of LUAD, the potential target genes of RUNX2, and its co-expressed genes were overlapped to obtain a set of specific genes for GO and KEGG enrichment analyses. RUNX2 overexpression in LUAD was validated using a large number of cases (2 418 LUAD and 1 574 non-tumor lung samples). The pooled SMD was 0.85 (95 % CI: 0.64-1.05) and the area under the curve (AUC) of the SROC was 0.86 (95 %CI: 0.83-0.89). The integrated HR was 1.20 [1.04-1.38], indicating that increased expression of RUNX2 was an independent risk factor for the poor survival of the LUAD patients. RUNX2 and its transcriptionally regulates potential target genes may promote cell proliferation and drug resistance of LUAD by modulating the cell cycle and MAPK signaling pathways. RUNX2 can provide new research directions for targeted drug therapy and drug resistance for LUAD treatment.

The Clinical Significance and Potential Molecular Mechanism of PTTG1 in Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is the major histological type of esophageal cancers worldwide. Transcription factor PTTG1 was seen highly expressed in a variety of tumors and was related to the degree of tumor differentiation, invasion, and metastasis. However, the clinical significance of PTTG1 had yet to be verified, and the mechanism of abnormal PTTG1 expression in ESCC was not clear. In this study, the comprehensive analysis and evaluation of PTTG1 expression in ESCC were completed by synthesizing in-house immunohistochemistry (IHC), clinical sample tissue RNA-seq (in-house RNA-seq), public high-throughput data, and literature data. We also explored the possible signaling pathways and target genes of PTTG1 in ESCC by combining the target genes of PTTG1 (displayed by ChIP-seq), differentially expressed genes (DEGs) of ESCC, and PTTG1-related genes, revealing the potential molecular mechanism of PTTG1 in ESCC. In the present study, PTTG1 protein and mRNA expression levels in ESCC tissues were all significantly higher than in non-cancerous tissues. The pool standard mean difference (SMD) of the overall PTTG1 expression was 1.17 (95% CI: 0.72-1.62, P < 0.01), and the area under curve (AUC) of the summary receiver operating characteristic (SROC) was 0.86 (95% CI: 0.83-0.89). By combining the target genes displayed by ChIP-seq of PTTG1, DEGs of ESCC, and PTTG1-related genes, it was observed that PTTG1 may interact with these genes through chemokines and cytokine signaling pathways. By constructing a protein-protein interaction (PPI) network and combining ChIP-seq data, we obtained four PTTG1 potential target genes, SPTAN1, SLC25A17, IKBKB, and ERH. The gene expression of PTTG1 had a strong positive correlation with SLC25A17 and ERH, which suggested that PTTG1 might positively regulate the expression of these two genes. In summary, the high expression of PTTG1 may play an important role in the formation of ESCC. These roles may be completed by PTTG1 regulating the downstream target genes SLC25A17 and ERH.

10-Hydroxycamptothecin (HCPT) nanosuspensions stabilized by mPEG1000-HCPT conjugate: high stabilizing efficiency and improved antitumor efficacy.

In this study, polyethylene glycol (PEG)ylated 10-hydroxycamptothecin (mPEG1000-HCPT) was synthesized and used as a stabilizer to prepare 10-hydroxycamptothecin (HCPT) nanosuspensions for their in vitro and in vivo antitumor investigation. The resultant HCPT nanosuspensions (HCPT-NSps) had a very high drug payload of 94.90% (w/w) and a mean particle size of 92.90±0.20 nm with narrow size distribution (polydispersity index of 0.16±0.01). HCPT-NSps could be lyophilized without the need of the addition of any cryoprotectant and then be reconstituted into nanosuspensions of a similar size by direct resuspension in water. HCPT was in crystalline form in HCPT-NSps. Using mPEG1000-HCPT as stabilizer, insoluble camptothecin and 7-ethyl-10-hydroxycamptothecin could also be easily made into nanosuspensions with similar features such as high drug payload, small particle size, and cryoprotectant-free freeze drying. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay indicated that the HCPT-NSps had a significantly higher cytotoxicity than HCPT injections, with 3.77 times lower IC50 value against HepG2 cells and 14.1 times lower IC50 value against MCF-7 cells. An in vivo study in H22 tumor-bearing mice after intravenous injection of HCPT-NSps demonstrated that HCPT-NSps significantly improved the antitumor efficacy compared to the commercially available HCPT injections (86.38% vs 34.97%) at the same dose of 5 mg/kg. Even at 1/4 of the dose, HCPT-NSps could also achieve a similar antitumor efficacy to that of HCPT injections. mPEG1000-HCPT may be a highly efficient stabilizer able to provide camptothecin-based drugs, and probably other antitumor agents containing aromatic structure, with unique nanosuspensions or nanocrystals for improved in vivo therapeutic efficacy.

High Drug Payload 10-Hydroxycamptothecin Nanosuspensions Stabilized by Cholesterol-PEG: In Vitro and In Vivo Investigation.

The objective of this study was to evaluate the feasibility of producing 10-hydroxycamptothecin nanosuspensions with high drug payload and to then determine the in vitro and in vivo characteristics of these nanosuspensions. Using cholesterol-PEG600 as a stabilizer, 10-hydroxycamptothecin nanosuspensions were successfully prepared using a precipitation-combined high-pressure homogenization method. A satisfactory drug payload of 90.39% (w/w) was achieved. The obtained nanosuspensions were spherical, with a mean particle size of 115.0 ± 0.4 nm, and they were monodisperse with a polydispersity index of 0.134 ± 0.001. The 10-hydroxycamptothecin remained in the same crystalline form in both the nanosuspensions and the bulk powder. In vitro, the 10-hydroxycamptothecin nanosuspensions released the encapsulated drug with nearly zero-order kinetics, and the accumulative release reached 90% within 72 hours. In vitro cytotoxicity assay showed that the 1 0-hydroxycamptothecin nanosuspensions had significantly enhanced cytotoxicity against HepG2 cells compared to the commercially available 10-hydroxycamptothecin injections. The in vivo study with H22 tumor-bearing mice and intravenous injection of the drug showed that in contrast to the 10-hydroxycamptothecin injections, the 10-hydroxycamptothecin nanosuspensions exhibited significantly enhanced biodistribution, particularly in the lung (393.40-fold AUC(0-24h)), liver (192.35-fold AUC(0-24h)), spleen (141.67-fold AUC(0-24h)) and tumor (64.21-fold AUC(0-24h)). The 10-hydroxycamptothecin nanosuspensions also showed improved antitumor therapeutic efficacy over the injections (89.83% vs. 30.56%). This suggests that cholesterol-PEG600 may be an effective stabilizer for the preparation of hydrophobic drug nanosuspensions and that 10-hydroxycamptothecin nanosuspensions are a promising drug delivery system for tumor treatment.

Uncoupling of K+ and Cl- transport across the cell membrane in the process of regulatory volume decrease.

It is accepted that K(+) and Cl(-) flows are coupled tightly in regulatory volume decrease (RVD). However, using self referencing microelectrodes, we proved that K(+) and Cl(-) transport mainly by channels in RVD was uncoupled in nasopharyngeal carcinoma CNE-2Z cells, with the transient K(+) efflux activated earlier and sustained Cl(-) efflux activated later. Hypotonic challenges decreased intracellular pH (pH(i)), and activated a proton pump-dependent H(+) efflux, resulting in a decline of extracellular pH (pH(o)). Modest decreases of pH(o) inhibited the volume-activated K(+) outflow and RVD, but not the Cl(-) outflow, while inhibition of H(+) efflux or increase of pH(o) buffer ability promoted K(+) efflux and RVD. The results suggest that the temporal dynamics of K(+) channel activities is different from that of Cl(-) channels in RVD, due to differential sensitivity of K(+) and Cl(-) channels to pH(o). H(+) efflux may play important roles in cell volume regulation, and may be a therapeutic target for human nasopharyngeal carcinoma.

Differential expression and roles of volume-activated chloride channels in control of growth of normal and cancerous nasopharyngeal epithelial cells.

We have previously shown that chloride channel activities were cell cycle-dependent and were involved in cell proliferation in nasopharyngeal carcinoma cells. In this study, the expression and roles of volume-activated chloride channels in cell growth were investigated in the poorly-differentiated human nasopharyngeal carcinoma cell (CNE-2Z) and its counterpart, the normal human nasopharyngeal epithelial cell (NP69-SV40T). Consistent with growth ability, the background chloride currents recorded under isotonic condition, the volume-activated chloride currents induced by 47% hypotonic challenges and the hyponinicity-induced regulatory volume decrease (RVD) were much larger in CNE-2Z cells than in NP69-SV40T cells, suggesting the up-regulation of expression of volume-activated chloride channels in cancerous cells. This was proved by the up-regulation of ClC-3 proteins, a candidate of volume-activated chloride channels, in the cancerous cells. Functional inhibition of chloride channel activities by the chloride channel blockers, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and tamoxifen, and knock-down of ClC-3 expression by specific ClC-3 siRNA attenuated the background currents, suppressed the activation of volume-activated chloride currents, decreased the hyponinicity-induced RVD and inhibited cell growth in the cancerous and normal cells. However, the sensitivities of the cancerous cells were much higher than that of the normal cells. Our data suggest that volume-activated chloride channels play a more important role in control cell proliferation in the cancerous cells than in the normal cells; the growth of cancerous cells is more dependent on the activities of volume-activated chloride channels than that of the normal cells. ClC-3 protein may be considered as a potential tumor marker and therapeutic target for human nasopharyngeal carcinoma.

ClC-3 is a main component of background chloride channels activated under isotonic conditions by autocrine ATP in nasopharyngeal carcinoma cells.

In this study, the activation mechanisms of the background chloride current and the role of the current in maintaining of basal cell volume were investigated in human nasopharyngeal carcinoma CNE-2Z cells. Under isotonic conditions, a background chloride current was recorded by the patch clamp technique. The current presented the properties similar to those of the volume-activated chloride current in the same cell line and was inhibited by chloride channel blockers or by cell shrinkage induced by hypertonic challenges. Extracellular applications of reactive blue 2, a purinergic receptor antagonist, suppressed the background chloride current in a concentration-dependent manner under isotonic conditions. Depletion of extracellular ATP with apyrase or inhibition of ATP release from cells by gadolinium chloride decreased the background current. Extracellular applications of micromolar concentrations of ATP activated a chloride current which was inhibited by chloride channel blockers and hypertonic solutions. Extracellular ATP could also reverse the action of gadolinium chloride. Transfection of CNE-2Z cells with ClC-3 siRNA knocked down expression of ClC-3 proteins, attenuated the background chloride current and prevented activation of the ATP-induced current. Furthermore, knockdown of ClC-3 expression or exposures of cells to ATP (10 mM), the chloride channel blockers 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and tamoxifen, or reactive blue 2 increased cell volume under isotonic conditions. The results suggest that ClC-3 protein may be a main component of background chloride channels which can be activated under isotonic conditions by autocrine/paracrine ATP through purinergic receptor pathways; the background current is involved in maintenance of basal cell volume.