The long-term survival of the doublet regimen of concurrent chemoradiation therapy for locoregionally advanced nasopharyngeal carcinoma: a retrospective study.

OBJECTIVE: This study introduces innovative strategies, the doublet regimen of concurrent chemoradiotherapy, to ensure longer survival for locoregionally advanced nasopharyngeal carcinoma. METHODS: We retrospectively reviewed 104 locoregionally advanced nasopharyngeal carcinoma patients who underwent taxane combined platinum-based concurrent chemoradiotherapy in our center between January 2013 and December 2018. All statistical analyses were performed using the Kaplan-Meier method (SPSS 23.0). Different groups were compared with the Wilcoxon rank-sum test. RESULTS: Ultimately, 104 patients were selected for this study, including 18 and 86 who received either concurrent chemoradiation therapy alone or concurrent chemoradiation therapy plus adjuvant chemotherapy, respectively. The median follow-up time for progression free survival was 53.0 months (IQR 48.5-57.5). The 3-years progression-free survival (PFS), overall survival (OS), local-regional recurrence-free survival (LRRFS) and distant metastasis-free survival (DMFS) rates of the doublet regimen of concurrent chemotherapy for locoregionally advanced nasopharyngeal carcinoma were 85.9%, 96.0%, 96.0% and 90.8%, respectively. Additionally, we analyzed the subgroups and found that the 3-years PFS, OS, LRRFS and DMFS rates for stage III versus stage IVa were 97.8% versus 75.5% (P = 0.000), 100% versus 92.5% (P = 0.004), 100% versus 92.4% (P = 0.015) and 97.8% versus 82.8% (P = 0.002), respectively. During concurrent chemotherapy, acute chemotherapy adverse events of grade 3 or 4 was only 18.3%. Leukopenia was the most common acute chemotherapy adverse event (in 10 patients [9.6%]), followed by neutropenia (in 8 patients [7.6%]). CONCLUSION: The doublet regimen of taxane plus platinum concurrent chemoradiotherapy resulted in improved long-term survival of locoregionally advanced nasopharyngeal carcinoma patients, especially for local control rate and warrants further prospective evaluation.

Long non-coding RNA SNHG16 promotes human placenta-derived mesenchymal stem cell proliferation capacity through the PI3K/AKT pathway under hypoxia.

BACKGROUND: The effect of hypoxia on mesenchymal stem cells (MSCs) is an emerging topic in MSC biology. Although long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) are reported to play a critical role in regulating the biological characteristics of MSCs, their specific expression and co-expression profiles in human placenta-derived MSCs (hP-MSCs) under hypoxia and the underlying mech anisms of lncRNAs in hP-MSC biology are unknown. AIM: To reveal the specific expression profiles of lncRNAs in hP-MSCs under hypoxia and initially explored the possible mechanism of lncRNAs on hP-MSC biology. METHODS: Here, we used a multigas incubator (92.5% N2, 5% CO2, and 2.5% O2) to mimic the hypoxia condition and observed that hypoxic culture significantly promoted the proliferation potential of hP-MSCs. RNA sequencing technology was applied to identify the exact expression profiles of lncRNAs and mRNAs under hypoxia. RESULTS: We identified 289 differentially expressed lncRNAs and 240 differentially expressed mRNAs between the hypoxia and normoxia groups. Among them, the lncRNA SNHG16 was upregulated under hypoxia, which was also validated by reverse transcription-polymerase chain reaction. SNHG16 was confirmed to affect hP-MSC proliferation rates using a SNHG16 knockdown model. SNHG16 overexpression could significantly enhance the proliferation capacity of hP-MSCs, activate the PI3K/AKT pathway, and upregulate the expression of cell cycle-related proteins. CONCLUSION: Our results revealed the specific expression characteristics of lncRNAs and mRNAs in hypoxia-cultured hP-MSCs and that lncRNA SNHG16 can promote hP-MSC proliferation through the PI3K/AKT pathway.

Hypoxia-inducible factor-1α-mediated upregulation of CD99 promotes the proliferation of placental mesenchymal stem cells by regulating ERK1/2.

BACKGROUND: As human placenta-derived mesenchymal stem cells (hP-MSCs) exist in a physiologically hypoxic microenvironment, various studies have focused on the influence of hypoxia. However, the underlying mechanisms remain to be further explored. AIM: The aim was to reveal the possible mechanisms by which hypoxia enhances the proliferation of hP-MSCs. METHODS: A hypoxic cell incubator (2.5% O2) was used to mimic a hypoxic microenvironment. Cell counting kit-8 and 5-ethynyl-20-deoxyuridine incorporation assays were used to assay the proliferation of hP-MSCs. The cell cycle was profiled by flow cytometry. Transcriptome profiling of hP-MSCs under hypoxia was performed by RNA sequencing. CD99 mRNA expression was assayed by reverse transcription-polymerase chain reaction. Small interfering RNA-mediated hypoxia-inducible factor 1α (HIF-1α) or CD99 knockdown of hP-MSCs, luciferase reporter assays, and the ERK1/2 signaling inhibitor PD98059 were used in the mechanistic analysis. Protein expression was assayed by western blotting; immunofluorescence assays were conducted to evaluate changes in expression levels. RESULTS: Hypoxia enhanced hP-MSC proliferation, increased the expression of cyclin E1, cyclin-dependent kinase 2, and cyclin A2, and decreased the expression of p21. Under hypoxia, CD99 expression was increased by HIF-1α. CD99-specific small interfering RNA or the ERK1/2 signaling inhibitor PD98059 abrogated the hypoxia-induced increase in cell proliferation. CONCLUSION: Hypoxia promoted hP-MSCs proliferation in a manner dependent on CD99 regulation of the MAPK/ERK signaling pathway in vitro.

Antitumor activity of the pachymic acid in nasopharyngeal carcinoma cells.

OBJECTIVE: To investigate the antitumour efficacy of pachymic acid (PA), which is a fungal extract component, on nasopharyngeal carcinoma (NPC) cells CNE-1, CNE-2. METHODS: We have chosen NPC cell line CNE-2 for the study, and the cells were treated with PA before the detection. CCK-8 assay was used to detect the proliferative ability, and Annexin V-PI double staining was used for the detection of apoptosis rate; and the nucleus damage was detected by transmission electron microscope, the protein expression of the DNA damage pathway were detected by Western blot. RESULTS: PA can significantly inhibited proliferation of CNE-1, CNE-2 cells. The proportion of apoptotic cells of all cell lines gradually increased in a dose-dependent manner induced by PA, P < 0.05. Meanwhile, the nucleus could be caused morphological changes and the expression of DNA damage-related proteins was upregulated by PA in CNE-2. CONCLUSIONS: PA can significantly inhibit cell proliferation and increase the apoptosis rates and may induce the apoptosis of the human NPC cells.

Down-regulation of PTEN by HCV core protein through activating nuclear factor-κB.

The hepatitis C virus (HCV) core protein is an important causative agent in HCV related hepatocellular carcinoma (HCC). Tumor suppressor gene PTEN appears to act in the liver at the crossroad of processes controlling cell proliferation. In this study we investigated the effect of the HCV core protein on the PTEN pathway in hepatocarcinogenesis. The HCV core was transfected stably into HepG2 cell. The effect of HCV core on cell proliferation and viability were detected by 3-(4, 5)-dimethylthiahiazo-(-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay, clonogenic survival assay and Fluorescence Activating Cell Sorter (FACS) analysis. The expressions of PTEN were detected by real time RT-PCR and/or Western blot analysis, also the mechanism of down-regulation of PTEN was explored by western blot, luciferase assay and RNA interference. We found the HCV core promoted cell proliferation, survival and G2/M phase accumulation. It downregulated PTEN at mRNA and protein level and activated PTEN downstream gene Akt accompanied with NF-κB activation. Furthermore, the inhibition of HCV core by its specific shRNAs decreased the effect of growth promotion and G2/M phase arrest, inhibited the expression of nuclear p65 and increased PTEN expression. The activity of PTEN was restored when treated with NF-κB inhibitor PDTC. By luciferase assay we found that NF-κB inhibited PTEN promoter transcription activity directly in HCV core cells, while PDTC was contrary. Our study suggests that HCV proteins could modulate PTEN by activating NF-κB. Furthermore strategies designed to restore the expression of PTEN may be promising therapies for preventing HCV dependent hepatocarcinogenesis.

Gadolinium triggers unfolded protein responses (UPRs) in primary cultured rat cortical astrocytes via promotion of an influx of extracellular Ca2+.

Gadolinium (Gd) and its complexes are utilized widely in industrial and clinical diagnoses. As a rare earth metal ion, free gadolinium (Gd(3+)) in the human body poses neurotoxic risks during its in vivo release and retention. In the central nervous system, astrocytes play a pivotal role in processing toxic metal ions. The present study evaluates the effects of Gd on cellular calcium homeostasis, a common mechanism that causes cell death, and on unfolded protein responses (UPRs), a mechanism for cell survival in response to toxic stimuli in mammalian cells. The experimental results indicate that the influx of extracellular Ca(2+) increases greatly after the exposure of astrocytes to Gd; however, no cell deaths were observed. Further evidence suggests the up-regulated expression of the endoplasmic reticulum (ER)-resident chaperone protein GRP78 by ER stress-mediated signal transductions, specifically the activation of ATF6, eIF2a, and IRE1. These results suggest that Gd promotes Ca(2+) influx, thus triggering UPRs, which can be closely associated to the resistance of astrocytes to Gd-induced cytotoxicity.

His-tagged protein purification by metal-chelate affinity extraction with nickel-chelate reverse micelles.

Di(2-ethylhexyl) phosphoric acid (HDEHP) was used as a transition metal ion chelator and introduced to the nonionic reverse micellar system composed of equimolar Triton X-45 and Span 80 at a total concentration of 30 mmol/L. Ni(II) ions were chelated to the HDEHP dimers in the reverse micelles, forming a complex denoted as Ni(II)R(2). The Ni(II)-chelate reverse micelles were characterized for the purification of recombinant hexahistidine-tagged enhanced green fluorescent protein (EGFP) expressed in Escherichia coli. The affinity binding of EGFP to Ni(II)R(2) was proved by investigation of the forward and back extraction behaviors of purified EGFP. Then, EGFP was purified with the affinity reverse micelles. It was found that the impurities in the feedstock impeded EGFP transfer to the reverse micelles, though they were little solubilized in the organic phase. The high specificity of the chelated Ni(2+) ions toward the histidine tag led to the production of electrophoretically pure EGFP, which was similar to that purified by immobilized metal affinity chromatography. A two-stage purification by the metal-chelate affinity extraction gave rise to 87% recovery of EGFP. Fluorescence spectrum analysis suggests the preservation of native protein structure after the separation process, indicating the system was promising for protein purification.

Synthesis, biocompatibility and cell labeling of L-arginine-functional beta-cyclodextrin-modified quantum dot probes.

A series of quantum dots (QDs), CdSe, CdSe/CdS and CdSe/ZnSe, coated with L-arginine-modified beta-cyclodextrin (beta-CD-L-Arg) were prepared in a solution of H2O and hexane by ultrasonic method and characterized using PL, UV-vis, TEM, EDX and FTIR techniques. We observed that beta-CD-L-Arg-coated QDs are water-soluble and stable with high colloidal properties in water. Their photophysical properties are similar to those of trioctylphosphine oxide (TOPO)-coated nanocrystals. The quantum yield (QY) of beta-CD-L-Arg/CdSe/ZnSe QDs in water is 68%, which is much higher than those of beta-CD-L-Arg/CdSe/CdS (26%) and beta-CD-L-Arg/CdSe (13%). The in vitro cytotoxicity of these QDs was evaluated in ECV-304, SH-SY5Y and Hela cells and low cytotoxicity was observed. In particular, the beta-CD-L-Arg/CdSe/ZnSe QDs presented lower cytotoxicity to these cells (CC(50) value is 173 microg/mL in ECV-304 cells for 48h). This may be due to the presence of the ZnSe and beta-CD-L-Arg outlayer, which may improve the biocompatibility of QDs. The QDs were further investigated for biological labeling in ECV-304 cells using confocal laser scanning fluorescence microscopy. We found that these QDs were capable of localing to the cytoplasm of cells. These results demonstrate that the beta-CD-L-Arg-coated QDs could be used as a potential photoluminescent nanocrystal probing agent with good biocompatibility.

A metal-chelate affinity reverse micellar system for protein extraction.

A new nonionic reverse micellar system is developed by blending two nonionic surfactants, Triton X-45 and Span 80. At total surfactant concentrations lower than 60 mmol/L and molar fractions of Triton X-45 less than 0.6, thermodynamically stable reverse micelles of water content (W(0)) up to 30 are formed. Di(2-ethylhexyl) phosphoric acid (HDEHP; 1-2 mmol/L) is introduced into the system for chelating transition metal ions that have binding affinity for histidine-rich proteins. HDEHP exists in a dimeric form in organic solvents and a dimer associated with one transition metal ion, including copper, zinc, and nickel. The copper-chelate reverse micelles (Cu-RM) are characterized for their W(0), hydrodynamic radius (R(h)), and aggregation number (N(ag)). Similar with reverse micelles of bis-2-ethylhexyl sodium sulfosuccinate (AOT), R(h) of the Cu-RM is also linearly related to W(0). However, N(ag) is determined to be 30-90 at W(0) of 5-30, only quarter to half of the AOT reverse micelles. Then, selective metal-chelate extraction of histidine-rich protein (myoglobin) by the Cu-RM is successfully performed with pure and mixed protein systems (myoglobin and lysozyme). The solubilized protein can be recovered by stripping with imidazole or ethylinediaminetetraacetic acid (EDTA) solution. Because various transition metal ions can be chelated to the reverse micelles, it is convinced that the system would be useful for application in protein purification as well as simultaneous isolation and refolding of recombinant histidine-tagged proteins expressed as inclusion bodies.

High doses of bifendate elevate serum and hepatic triglyceride levels in rabbits and mice: animal models of acute hypertriglyceridemia.

AIM: To investigate the effects of bifendate on serum and hepatic lipids level in rabbits and mice. METHODS: Animals were administered bifendate [powdered pill suspended in 0.5% sodium carboxymethylcellulose (CMC)] at increasing doses (0.25-1 g/kg, ig). Blood lipid and apolipoprotein levels were measured using commercially available assay kits. RESULTS: The treatment of rabbits with a single dose of bifendate (0.3 g/kg) caused a time-dependent and biphasic change in serum triglyceride (TG) levels, with the value reaching a maximum (3-fold increase compared to the baseline value) between 24 and 36 h post-dosing. When mice were orally treated with bifendate (0.25-1 g/kg), serum TG levels increased by 39%-76% and 14%-39% at 24 and 48 h post-dosing, respectively. When given at daily doses of 0.25 and 1 g/kg for 4 d, bifendate increased serum TG levels (56%-79%), with concomitant elevations in apolipoprotein A-I and apolipoprotein B levels at 24 h after the last dosing. TG levels were also increased (11%-43%) in liver samples of mice receiving single or multiple doses of bifendate. However, bifendate treatment caused slight reductions in serum and hepatic total cholesterol levels (9%-13%). The hypertriglyceridemia induced by bifendate was ameliorated by fenofibrate but not inositol nicotinate treatment in mice. CONCLUSION: The findings suggest that bifendate treatment at high oral doses can cause an acute elevation in serum and hepatic TG levels.