Pancreatic Ductal Cell-Derived Extracellular Vesicles Are Effective Drug Carriers to Enhance Paclitaxel's Efficacy in Pancreatic Cancer Cells through Clathrin-Mediated Endocytosis.

Chemo-resistance challenges the clinical management of pancreatic ductal adenocarcinoma (PDAC). A limited admittance of chemotherapeutics to PDAC tissues is a key obstacle in chemotherapy of the malignancy. An enhanced uptake of drugs into PDAC cells is required for a more effective treatment. Extracellular vesicles (EVs), especially small EVs (sEVs), have emerged as drug carriers for delivering chemotherapeutics due to their low immunogenicity and propensity for homing toward tumor cells. The present study evaluated sEVs derived from six different human cell lines as carriers for paclitaxel (PTX). The encapsulation of the chemotherapeutics was achieved using incubation, sonication and electroporation. The cytotoxicity of the EV drugs was evaluated by MTS assay. While sonication led to a higher efficiency of drug loading than incubation and electroporation, PTX loaded through incubation with HPNE-derived sEVs (HI-PTX) was the most efficacious in killing PDAC cells. Furthermore, HI-PTX was taken up by PDAC cells more efficiently than other EV drugs, implying that the efficacy of HI-PTX is associated with its efficient uptake. This was supported by the observation that the cytotoxicity and uptake of HI-PTX is mediated via the clathrin-dependent endocytosis. Our results indicate that the hTERT-HPNE cell-derived EVs are effective drug carriers to enhance paclitaxel's efficacy in PDAC cells.

MFAP2 Promotes the Proliferation of Cancer Cells and Is Associated With a Poor Prognosis in Hepatocellular Carcinoma.

BACKGROUNDS: Microfibril-associated protein 2 (MFAP2) is an extracellular matrix protein that regulates the function of microfibrils by interacting with fibrillin. MFAP2 has been reported to play an important role in metabolic diseases and has been shown to be significantly overexpressed in head and neck squamous cell carcinoma and Hepatocellular carcinoma (HCC). However, the molecular function and prognostic value of MFAP2 have never been reported in HCC or other tumors. METHODS: In the present study, expression characteristics of MFAP2 in HCC, its influence on the development of HCC, as well as its function and potential mechanism in HCC were verified by Quantitative reverse transcription-polymerase chain reaction, bioinformatics data mining and in vitro cell experiments. RESULTS: MFAP2 was prominently high-expressed in HCC and associated with cancer stages. HCC patients with higher MFAP2 expression displayed lower overall survival (OS) and disease-specific survival(DSS), while there was no significant difference in recurrence-free survival (RFS). In vitro experiments showed that downregulation of MFAP2 inhibited proliferation, migration level of HCC cells. Transcription factors, DNA methyltransferases, immune factors may interact with MFAP2 mRNA to promote tumor progression in HCC. CONCLUSION: These findings suggest that MFAP2 may play a key role in the development of HCC. Therefore, MFAP2 may be a valuable prognostic marker and an effective anticancer target in HCC.

Extracellular Vesicles in the Development of Cancer Therapeutics.

Extracellular vesicles (EVs) are small lipid bilayer-delimited nanoparticles released from all types of cells examined thus far. Several groups of EVs, including exosomes, microvesicles, and apoptotic bodies, have been identified according to their size and biogenesis. With extensive investigations on EVs over the last decade, it is now recognized that EVs play a pleiotropic role in various physiological processes as well as pathological conditions through mediating intercellular communication. Most notably, EVs have been shown to be involved in cancer initiation and progression and EV signaling in cancer are viewed as potential therapeutic targets. Furthermore, as membrane nanoparticles, EVs are natural products with some of them, such as tumor exosomes, possessing tumor homing propensity, thus leading to strategies utilizing EVs as drug carriers to effectively deliver cancer therapeutics. In this review, we summarize recent reports on exploring EVs signaling as potential therapeutic targets in cancer as well as on developing EVs as therapeutic delivery carriers for cancer therapy. Findings from preclinical studies are primarily discussed, with early phase clinical trials reviewed. We hope to provide readers updated information on the development of EVs as cancer therapeutic targets or therapeutic carriers.

Study on the oxidation potential of the water-soluble components of ambient PM2.5 over Xi'an, China: Pollution levels, source apportionment and transport pathways.

Reactive oxygen species (ROS) are a class of substances that are of general concern in terms of human health and are used to represent the oxidation potential (OP) of the atmosphere. In this study, the ROS levels in 116 daily fine particulate matter (PM2.5) samples taken over Xi'an in 2017 were measured with the dithiothreitol (DTT) method. The sources of DTTv (volume-based DTT consumption) in PM2.5 as well as their contributions were identified by both positive matrix factorization (PMF) and multiple linear regression (MLR) based on the measured chemical species in particulate matter (PM). The results showed that the yearly average DTTv over Xi'an was 0.53 nmol/min/m3 (0.19-1.10 nmol/min/m3). The highest DTTv level occurred in winter, followed by spring, summer and autumn. DTTv was the most strongly correlated with the water-soluble organic carbon (WSOC; r = 0.85), but the effects of WSOC on DTTv were very limited. SO2, NO2, CO, elemental carbon (EC) and K+ (r > 0.64) had moderate correlations with DTTv and were moderately related to environmentally persistent free radicals (EPFRs) (r = 0.56). The linear mixed-effects model showed that pollutants originating from incomplete combustion had greater effects on DTTv than those from complete combustion. Source apportionment results from PMF showed that motor vehicle emissions (27.4%), secondary sulfates (21.6%) and coal combustion sources (18.8%) were more important contributors to the DTTv in PM2.5 than dust sources (8.4%), metal processing (4.9%), industrial emissions (11.3%) and secondary nitrates (7.5%). The PMF results for the DTTv were consistent with the MLR results, which verified that both PMF and MLR are feasible methods for source apportionment of PM2.5 as well as specific species such as ROS and EPFRs. Backward trajectory clusters showed that the dominant cluster groups were local and regional transport, while the OP of the PM2.5 over Xi'an was affected more by long-range transport than by local transport. As stated above, the improvement of atmospheric oxidation potential require not only regional efforts but also large-scale joint cooperation. Furthermore, this study on the OP of PM as well as the specific source information provides important guidance for health effect research.

Environmentally Persistent Free Radical (EPFR) Formation by Visible-Light Illumination of the Organic Matter in Atmospheric Particles.

A secondary process may be an important source of environmentally persistent free radicals (EPFRs) in atmospheric particulates; yet, this process remains to be elucidated. This study demonstrated that secondary EPFRs could be generated by visible-light illumination of atmospheric particulate matter (PM), and their lifetimes were only 30 min to 1 day, which were much shorter than the lifetimes of the original EPFRs in PM. The yields of secondary EPFRs produced by PM could reach 15-60% of those of the original EPFRs. The extractable organic matter contributed to the formation of secondary EPFRs (∼55%), and a humic-like substance was the main precursor of the secondary EPFRs and was also the most productive precursor compared to the other aerosol components. The results of simulation experiments showed that the secondary EPFRs generated by the extractable and nonextractable PM components were similar to those produced by phenolic compounds and polycyclic aromatic hydrocarbons, respectively. We have found that oxygen molecules play an important role in the photochemical generation and decay of EPFRs. The reactive oxygen capture experiments showed that the original EPFRs may contribute to singlet oxygen generation, while the secondary EPFRs generated by photoexcitation may not produce singlet oxygen or hydroxyl radicals.

Source apportionment of environmentally persistent free radicals (EPFRs) in PM2.5 over Xi'an, China.

Environmentally persistent free radicals (EPFRs) have recently attracted considerable attention as a new type of environmental risk substance due to their potential health effects. However, the sources and contributions of EPFRs in PM2.5 are not yet clear. Therefore, this study reports the sources of EPFRs in PM2.5 based on chemical analysis and positive matrix factorization (PMF). Daily PM2.5 samples (116) were collected in Xi'an city from April 4 to December 29, 2017, and were quantitatively analyzed for EPFRs and other chemical constituents. The PMF model revealed contributions from five main sources of EPFRs in PM2.5 (dust sources, coal combustion, secondary nitrates, industrial emissions and motor vehicle emissions). Coal combustion, motor vehicle emissions and dust sources are the top three contributors to EPFRs (76.12% in total). Coal combustion is highly important for PM2.5 (35.10%) and EPFRs (16.75%). A high dust source contribution to EPFRs in spring may be due to dust storm events. Motor vehicle emissions are the top contributor to EPFRs, with a mean percentage of 32.13%. Secondary nitrates barely contributes to EPFRs (3.42%), indicating an EPFR origin from primary emissions rather than secondary inorganic reactions. Industrial emissions contribute less to PM2.5 (4.31%) than to EPFRs (11.71%), which implies that fossil fuels contains many high-molecular-weight organics that could emit EPFRs. Integrating the PMF results with meteorological data revealed that atmospheric pollutants emitted in Xi'an city center could be transported to the sampling site by southern winds. These results suggest the need for further studies on the public health effects of EPFRs and can be used to help formulate source control measures to reduce the potential health risks posed by EPFRs in PM2.5.

[Characteristics of Carbonaceous Aerosol Pollution in PM2.5 in Xi'an].

Mass concentration, seasonal variation and sources of organic carbon (OC), element carbon (EC), methanol-soluble organic carbon (MSOC), and seven carbon components (OC1-4, EC1-3) were detected by thermal-optical analysis of 353 PM2.5 samples in Xi'an in 2017. The results show that the average mass concentrations of OC, EC, and MSOC were (17.56±11.83), (4.08±2.95) and (11.10±6.77) µg·m-3, respectively. The seasonal trend of the OC concentration follows the order winter > spring > summer > autumn. The seasonal trend in EC concentration follows the order winter > spring≈autumn > summer. The average MSOC/OC value is 0.64±0.20. The highest value is observed in winter and the lowest in summer. The correlation between OC and EC is good in spring (r2=0.76), but the correlation is poor in winter (r2=0.43). These results indicate that the source of the carbon aerosols was different. The content of secondary organic aerosols was estimated by the EC tracing method. The average mass concentration of SOC accounted for 51.9%, 38.4%, 37.3% and 44.0% of OC in spring, summer, autumn, and winter, respectively. The main sources of carbonaceous aerosols were analyzed by principal component analysis. The results show that carbonaceous aerosols originate mainly from coal and vehicle emissions in Xi'an.

The Efficacy of Cognitive Behavioral Therapy to Treat Depression and Anxiety and Improve Quality of Life Among Early-Stage Breast Cancer Patients.

PURPOSE: Positive results have appeared among nonmetastatic breast cancer patients with the use of cognitive behavioral therapy (CBT). However, earlier stage patient results have been mixed. This novelty of this study was the focus on stage I and II breast cancer patients. The objective of the current study was to conduct a meta-analysis of psychosocial functions in early-stage breast cancer survivors to determine its efficacy. METHODS: A search of Cochrane Library, EMBASE, MEDLINE, PsycInfo, and PubMed yielded 3237 abstracts, which were independently evaluated by research pairs. Meta-analysis was conducted on 8 studies that included a total of 1053 patients. Psychosocial functions were categorized according to 3 domains: (1) anxiety, (2) depression, and (3) quality of life. RESULTS: Improvement in anxiety was observed in patients treated with CBT relative to controls without CBT ( P = .04). Depression and quality of life improvement was not observed in the CBT group within or after 4 months of treatment ( P > .05). CONCLUSIONS: The results indicated that observed improvements in anxiety in patients with early-stage breast cancer were moderate. The effectiveness of CBT for the improvement of patient outcomes could not be determined, given the methodological and clinical shortcomings of the included trials.

Characteristics of environmentally persistent free radicals in PM2.5: Concentrations, species and sources in Xi'an, Northwestern China.

Environmentally persistent free radicals (EPFRs) are a new class of environmental risk substances that can stably exist in atmospheric particles and pose a potential threat to human health. In this study, electron paramagnetic resonance (EPR) spectroscopy was used to study the concentration levels, species characteristics, and sources of EPFRs in PM2.5 in Xi'an in 2017. The results showed that the concentrations of EPFRs in PM2.5 in Xi'an in 2017 ranged from 9.8 × 1011 to 6.9 × 1014 spins/m3. The highest concentration of EPFRs occurred in winter when the average concentration was 2.1 × 1014 spins/m3. The lowest concentration of EPFRs occurred in autumn when the average concentration was 7.0 × 1013 spins/m3. According to the annual average atmospheric concentration of EPFRs, the amount of EPFRs inhaled by people in Xi'an is equivalent to approximately 5 cigarettes per person per day and approximately 23 cigarettes per person per day in winter when haze occurs. The results of the study on the EPFR characteristics show that the EPFRs in PM2.5 in Xi'an are mainly C-center organic radicals that are primarily non-decaying types, accounting for approximately 75% and 85% of total concentration of EPFRs in autumn and winter, respectively. Finally, a correlation analysis was used to explore the origins of EPFRs in PM2.5. Significant positive correlations were found between EPFRs and SO2, NO2 and the thermally derived OC3 and OC4 carbonaceous components. The results suggested that coal-fired and traffic may be important sources of EPFRs in PM2.5 in Xi'an. In addition, EPFRs are significantly positively correlated with O3 in summer, suggesting that some EPFRs may also originate from secondary processes. This study provides important basic data and evidence for further assessments of the potential health risks of EPFRs in PM2.5 and the development of effective air pollution control measures.

Enhanced health risks from exposure to environmentally persistent free radicals and the oxidative stress of PM2.5 from Asian dust storms in Erenhot, Zhangbei and Jinan, China.

Asian dust storms can increase the level of atmospheric pollution over regions downwind of dust storms and may have adverse health effects on residents along the sandstorm transmission route. This study was the first to report the concentration levels, properties and possible sources of environmentally persistent free radicals (EPFRs) and oxidative potential in atmospheric PM2.5 at the three sites of Erenhot, Zhangbei, and Jinan along the transport route of Asian dust storms during the occurrence of Asian dust storms in the spring of 2016. Under non-sandstorm weather conditions, the average EPFR concentrations at the three sites were Zhangbei>Jinan>Erenhot, while the PM-induced oxidative potential levels were Erenhot>Jinan>Zhangbei. The PM2.5 concentration increased significantly during dust storm events, and the total atmospheric concentration of EPFRs (spins/m3) and total oxidation potential (a.u./m3) of PM2.5 simultaneously increased. However, the EPFR concentration in PM2.5 (spins/g) and the unit mass of the PM oxidation potential (a.u./g) were significantly reduced. Electron paramagnetic resonance analysis combined with backward trajectory analysis and MODIS products showed that Asian dust storms can carry EPFRs over long distances. Correlation analysis showed that the atmospheric concentrations of EPFRs were positively correlated with elemental carbon (EC) for the Zhangbei and Jinan samples but were not significantly correlated with EC for the Erenhot samples, indicating that combustion may be an important source of EPFRs for the Zhangbei and Jinan samples. In contrast, the EPFRs in the Erenhot samples were more affected by dust/sand. The EPFR concentration levels showed a significant positive correlation with the oxidation potentials for the Erenhot and Zhangbei samples and showed negative correlations for the Jinan samples, suggesting that the EPFRs in the Erenhot and Zhangbei samples may provide an important contribution to the oxidative stress in PM2.5. In contrast, the oxidation potential for the Jinan samples was mainly caused by substances other than EPFRs. This study presents a basic understanding of the potential health effects of Asian dust storms, and this information can be used to assess the health risks of Asian dust storms in future studies.

Combined pretreatment with 18F-FDG PET/CT and Comet assay guides the concurrent chemoradiotherapy of locally advanced cervical cancer: study protocol for a randomized controlled trial.

BACKGROUND: Cisplatin-based chemoradiation is the standard of care for patients with locally advanced cervical cancer. Nevertheless, an increasing number of radio-resistant tumors still recur. METHODS AND DESIGN: Three hundred cervical cancer patients with FIGO stages IB2-IVA and no para-aortic lymphadenopathy (> 10 mm) will be enrolled. All patients will be randomly divided into four arms to receive either (1) intensity modulated radiation therapy (IMRT), (2) RapidArc, (3) positron emission tomography/computed tomography (PET/CT) with F-18 fluorodeoxyglucose (FDG), or (4) Comet assay-guided IMRT, PET/CT, and Comet assay-guided RapidArc. All patients will receive definitive radiotherapy consisting of external beam whole pelvic radiation therapy and high-dose rate intracavitary brachytherapy. Cisplatin 30 mg/m2 weekly will be administered concurrently for five courses. Two to four cycles of TP (Taxol 135 mg/m2, D1, and DDP 75 mg/m2, D1-3) sequential chemotherapy will be performed according to MRI or PET/CT after cisplatin-based chemoradiation. The primary outcome measure is progression-free survival, and the second outcome measures are overall survival and time to progression. DISCUSSION: RapidArc has an obvious advantage in improving the degree of target coverage, improving organs at risk, sparing healthy tissue, and significantly reducing the treatment time. FDG-PET/CT can increase the agreement between biopsies and delineated tumor volume and has the potential to positively impact the course of treatment. The Comet assay is attractive as a potential clinical test of tumor radiosensitivity. During radiotherapy, accurately defining disease areas is critical to avoid the unnecessary irradiation of normal tissue. Based on FDG-PET/CT and Comet assay, higher doses can be safely delivered to accurate tumor volumes, while the doses to the bladder and rectum are relatively low. TRIAL REGISTRATION: ClinicalTrials.gov Protocol Registration and Results System Receipt Release Date: May 21, 2017 - Retrospectively registered. NCT03163979 .

Dominant Fraction of EPFRs from Nonsolvent-Extractable Organic Matter in Fine Particulates over Xi'an, China.

To understand the nature and possible sources of environmentally persistent free radicals (EPFRs) in atmospheric aerosols, the present study used a solvent extraction method to fractionate aerosol components with different polarities and solvent resistance in fine particulate matter (PM2.5) from Xi'an, China. The characteristics of EPFRs, that is., their concentration, type and lifetime, were obtained based on their electron paramagnetic resonance spectra. The results showed that the EPFRs in the PM2.5 samples were carbon-centered with a nearby heteroatom ( g = 2.0031) and had a long half-life of more than 3 years. Nearly all of the extractable EPFRs were detected in the water-insoluble organic fraction and showed characteristics indicating that may contain oxygen-centered radical ( g = 2.0038). Most of the total EPFRs in the PM2.5 were derived from solvent-resistant organic matter (88%), which likely consisted of graphene oxide analogues. The results suggest that previous studies may have missed the major proportion of EPFRs in atmospheric particulates if they only focused on solvent-extractable or metallic oxide-formed EPFRs. Our results showed that the EPFR concentration was significantly and positively correlated with the elemental carbon and NO2 concentrations, suggesting that traffic emissions may be an important source of EPFRs in PM2.5 over Xi'an.

Elevated DNA polymerase iota (Poli) is involved in the acquisition of aggressive phenotypes of human esophageal squamous cell cancer.

DNA polymerase iota (Polι) can repair several types of DNA damage but has extremely low fidelity. Previous studies have shown an aberrantly elevated Polι expression in human esophageal squamous cell cancer tissues. However, there were few reports describing the role of Polι in esophageal cancer progression. Based on Real-time PCR assay, we found Polι expression was up-regulated in esophageal cancer tissues compared to adjacent normal tissues and overexpression of Polι was correlated to lymph node metastasis. Clonogenic assay and transwell chamber assay showed that overexpression of Polι had higher clongenic capability and invasive tendency in human esophageal squamous cell cancer cells. Expression of cyclin D1, an important cell cycle regulator, was found to be associated with that of Polι in tissue samples and cancer cells as analyzed by real-time PCR, immunohistochemistry, Western blotting and immunofluorescence assay. Flow cytometry analysis further showed that cell cycle distribution was altered in Polι overexpressing cells. These results indicated that expression of Polι correlates significantly with tumor proliferation and invasion. We conclude that Polι is involved in the degree of aggressiveness of human esophageal squamous cell cancer.