量子点应用于人骨肉瘤HOS细胞系研究的生物毒性评价

目的:将合成的两种量子点应用于研究人骨肉瘤HOS细胞系,初步检测其生物毒性,以确定本研究所制备量子点可否应用于骨肉瘤的基础研究。方法:将生长良好的HOS细胞与制备的两种量子点分别共培养,使用MTT试剂盒检测不同时间点细胞活性,实验进行三次,取其平均值,分析所得数据,并绘制出量子点浓度-细胞活性曲线,分析得出两者之间的量效关系。结果:1.4μM的CdTe/ZnS QDs和0.275μM的Cd Te/Cd S QDs分别是本实验中对HOS细胞的最高毒性浓度。较短时间(30 min)的暴露分别导致了48.6±0.9%和31.9±0.8%的细胞死亡,3 h后分别有33.7±2.3%和49.4±1.1%的细胞存活。而在孵育了18 h之后,只有28.0±1.6%和15.3±1.6%的细胞存活。我们可以观察到均为典型的时间/浓度曲线。结论:选用适宜浓度以及共培养时间,本实验制备的量子点完全可以满足纳米量子点粒子使用于HOS细胞研究的基本生物学条件,可以进行人骨肉瘤HOS细胞测温等的一些列实验操作。由于量子点自身优越的光学性能以及可接受的生物安全性,在肿瘤研究领域具有很大的潜力,将会成为肿瘤示踪、检测、以及靶向治疗新的有力工具。     

Contrasting effects of stanniocalcin-related polypeptides on macrophage foam cell formation and vascular smooth muscle cell migration

Stanniocalcin (STC) is a calcium- and phosphate-regulating hormone secreted by the corpuscles of Stannius, an endocrine gland of bony fish. Its human homologues, STC1 and STC2 showing 34% amino acid identity each other, are expressed in a variety of human tissues. To clarify their roles in atherosclerosis, we investigated the effects of their full-length proteins, STC1(18–247) and STC2(25–302), and STC2-derived fragment peptides, STC2(80–100) and STC2(85–99), on inflammatory responses in human umbilical vein endothelial cells (HUVECs), human macrophage foam cell formation, the migration and proliferation of human aortic smooth muscle cells (HASMCs) and the extracellular matrix expression. All these polypeptides suppressed lipopolysaccharide-induced expressions of interleukin-6, monocyte chemotactic protein-1, and intercellular adhesion molecule-1 in HUVECs. Oxidized low-density lipoprotein-induced foam cell formation was significantly decreased by STC1(18–247) and increased by STC2(80–100) and STC2(85–99), but not STC2(25–302), in human macrophages. Expression of acyl-CoA:cholesterol acyltransferase-1 (ACAT1) was significantly suppressed by STC1(18–247) but stimulated by STC2(80–100) and STC2(85–99). Expression of ATP-binding cassette transporter A1 was significantly stimulated by STC1(18–247). Neither STC1(18–247) nor STC2-derived peptides significantly affected CD36 expression in human macrophages or HASMC proliferation. STC2(80–100) and STC2(85–99) significantly increased HASMC migration, whereas STC1(18–247) significantly suppressed the angiotensin II-induced HASMC migration. Expressions of collagen-1, fibronectin, matrix metalloproteinase-2, and elastin were mostly unchanged with the exception of fibronectin up-regulation by STC2(80–100). Our results demonstrated the contrasting effects of STC1 and STC2-derived peptides on human macrophage foam cell formation associated with ACAT1 expression and on HASMC migration. Thus, STC-related polypeptides could serve as a novel therapeutic target for atherosclerosis.     

Binding of B‐cell maturation antigen to B‐cell activating factor induces survival of multiple myeloma cells by activating Akt and JNK signaling pathways

B‐cell maturation antigen (BCMA) is expressed on normal and malignant plasma cells and represents a potential target for therapeutic intervention. In this study, we characterized the mechanism underlying the protein kinase B (Akt) and c‐Jun N‐terminal kinase (JNK) pathways and BCMA interactions in regulating multiple myeloma (MM) cell survival. It was found that the expression levels of B cell‐activating factor (BAFF) and BCMA were increased in MM cells as compared with those in normal controls. The proliferation of U266 cells was induced by recombinant human BAFF (rhBAFF) and could also be decreased by BCMA siRNA. The expression of Bcl‐2 protein was up‐regulated, and Bax protein was down‐regulated after rhBAFF treatment, which could be reversed by BCMA siRNA. Similarly, the protein p‐JNK and p‐Akt were activated by rhBAFF and could be changed by BCMA siRNA. In addition, the BCMA mRNA and protein expression levels were decreased after treatment with Akt and JNK pathway inhibitors. These results suggest that Akt and JNK pathways are involved in the regulation of BCMA. A novel BAFF/BCMA signalling pathway in MM may be a new therapeutic target for MM. Copyright © 2016 John Wiley & Sons, Ltd.     

The effect of chronic cadmium exposure on the pharmacokinetics of theophylline and ciprofloxacin in rats

Cadmium has been associated with a number of adverse health effects but the impact of those effects on the pharmacokinetics of different drugs has not been investigated. Therefore, the pharmacokinetics of theophylline and ciprofloxacin were studied in cadmium-exposed and control rats (72 rats) following i.p. (6.5mg/kg) and p.o. (10mg/kg) administration, respectively. The third-generation offsprings of rats exposed to 100 microg/mL of cadmium chloride in drinking water were used in this study. Following 8 weeks of exposure, animals received the drugs as a single dose. Blood samples were withdrawn at different time-points and the plasma concentrations of both drugs were analyzed by HPLC. The pharmacokinetic parameters of theophylline and ciprofloxacin were altered significantly in the cadmium-exposed animals. For theophylline, a statistically significant increase (p<0.0001) in C(max) (69%) and AUC(0-)(infinity) (68%) of theophylline in the cadmium-exposed rats as compared to the control were observed. A corresponding significant (p<0.0001) reduction of 41% in clearance (CL/F) of theophylline was detected in the exposed group. Neither the half-life nor the mean residence time (MRT) showed any significant change due to the exposure to cadmium. For ciprofloxacin, no significant difference was seen in the C(max) of the exposed group as compared to the control animals. However, a delay in T(max) was observed in the exposed group (from 0.16(+/-0.003) to 0.37(+/-0.14)h). A small, but significant increase in t(1/2) (p<0.05) was detected (1.74(+/-0.25) vs. 1.45(+/-0.12)h). A significant reduction (p<0.05) of CL/F from 30.54(+/-1.9) to 24.01(+/-3.81)mL/min/kg was seen in the treated group. The current investigation showed that chronic exposure to cadmium could have a very significant impact on altering the pharmacokinetic parameters of various drugs. Therefore, in cadmium-polluted areas, dose adjustments and drug monitoring, especially for drugs with a narrow therapeutic window, should be carried out.     

CA9 transcriptional expression determines prognosis and tumour grade in tongue squamous cell carcinoma patients

CA9 is a member of the carbonic anhydrases’ family, that is often expressed in cancer cells under hypoxic condition. However, the role of CA9 in the molecular mechanisms of tongue squamous cell carcinoma (TSCC) pathogenesis remains unclear. CA9 expression was analysed using the TCGA database, and its influence on survival was performed using Kaplan-Meier, LASSO and COX regression analyses. The correlation between CA9 and immune infiltration was investigated by CIBERSORT and ESTIMATE. Moreover, the relationship between CA9 expression and downstream molecular regulation pathways was analysed by GSEA, GO and WGCNA. CA9 expression correlated with clinical prognosis and tumour grade in TSCC. Moreover, CA9 expression potentially contributes to the regulation of cancer cell differentiation and mediates tumour-associated genes and signalling pathways, including apoptosis, hypoxia, G2M checkpoint, PI3K/AKR/mTOR signalling and TGF-beta signalling pathways. However, the follicular helper T cells, regulatory T cells, immune and stromal scores showed no significance between high and low CA9 expression groups. These findings suggested that CA9 plays a critical role of TSCC prognosis and tumour grade. CA9 expression significantly correlated with the regulation of cell differentiation, various oncogenes and cancer-associated pathways.     

Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane

Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications.     

Alpha‐fetoprotein accelerates the progression of hepatocellular carcinoma by promoting Bcl‐2 gene expression through an RA‐RAR signalling pathway

Previous studies have found that alpha‐fetoprotein (AFP) can promote the proliferation of hepatoma cells and accelerate the progression of hepatocellular carcinoma (HCC). However, the exact mechanism of action remains unclear. Recent bioinformatics studies have predicted the possible interaction between AFP and retinoic acid receptors (RARs). Thus, the purpose of this study was to investigate the molecular mechanism through which AFP promotes tumour cell proliferation by interfering with the RA‐RAR signal pathway. Our data indicated that AFP could significantly promote the proliferation and weaken ATRA‐induced apoptosis of hepatoma cells. Besides, cytoplasmic AFP interacts with RAR, disrupting its entrance into the nucleus, which in turn affects the expression of the Bcl‐2 gene. In addition, knockdown of AFP in HepG2 cells was synchronously associated with an incremental increase of RAR binding to DNA, as well as down‐regulation of Bcl‐2; the opposite effect was observed in AFP gene‐transfected HLE cells. Moreover, a similar effect of AFP was detected in tumour tissues with high serum AFP, but not in adjacent non‐cancerous liver tissues, or HCC tissues with low serum AFP levels. These results indicate that AFP acts as signalling molecule and prevents RAR from entering into the nucleus by interacting with RAR, thereby promoting the expression of Bcl‐2. Our data reveal a novel mechanism through which AFP regulates Bcl‐2 expression and further suggest that AFP may be used as a novel target for treating HCC.     

Androgen receptor suppresses vasculogenic mimicry in hepatocellular carcinoma via circRNA7/miRNA7‐5p/VE‐cadherin/Notch4 signalling

Androgen receptor (AR) can suppress hepatocellular carcinoma (HCC) invasion and metastasis at an advanced stage. Vasculogenic mimicry (VM), a new vascularization pattern by which tumour tissues nourish themselves, is correlated with tumour progression and metastasis. Here, we investigated the effect of AR on the formation of VM and its mechanism in HCC. The results suggested that AR could down‐regulate circular RNA (circRNA) 7, up‐regulate micro RNA (miRNA) 7‐5p, and suppress the formation of VM in HCC Small hairpin circR7 (ShcircR7) could reverse the impact on VM and expression of VE‐cadherin and Notch4 increased by small interfering AR (shAR) in HCC, while inhibition of miR‐7‐5p blocked the formation of VM and expression of VE‐cadherin and Notch4 decreased by AR overexpression (oeAR) in HCC. Mechanism dissection demonstrated that AR could directly target the circR7 host gene promoter to suppress circR7, and miR‐7‐5p might directly target the VE‐cadherin and Notch4 3′UTR to suppress their expression in HCC. In addition, knockdown of Notch4 and/or VE‐cadherin revealed that shVE‐cadherin or shNotch4 alone could partially reverse the formation of HCC VM, while shVE‐cadherin and shNotch4 together could completely suppress the formation of HCC VM. Those results indicate that AR could suppress the formation of HCC VM by down‐regulating circRNA7/miRNA7‐5p/VE‐Cadherin/Notch4 signals in HCC, which will help in the design of novel therapies against HCC.