Liping Peng

Nanomicelles loaded with doxorubicin and curcumin for alleviating multidrug resistance in lung cancer

Purpose A new type of polymeric micelle (PM) was assembled using a polyethylene glycol (PEG)-linked (PEGylated) amphiphilic copolymer and d-tocopheryl PEG1000 succinate (TPGS1000). The micelles were used to deliver doxorubicin (DOX) and curcumin (CUR) for alleviating multidrug resistance (MDR) in lung cancer cells while enhancing the therapeutic efficacy of DOX. Methods Micelles loaded with DOX and CUR were assembled using a film-forming technique. Micelles were used to treat A549/Adr cells to find out whether micelles had the ability to reverse the MDR of A549/Adr cells. Some investigations were conducted using tumor-bearing mice to assess whether these micelles had enhanced antitumor efficacy as compared to DOX alone or the combination of DOX and CUR. Results Some micelles (DOX + CUR)–PMs had a small average size of about 17 nm and showed definite ability to deliver both DOX and CUR into DOX-resistant A549/Adr cells. The PMs had high cytotoxicity toward A549/Adr cells when the applied equivalent DOX dose was 1 µg/mL or higher. The cellular uptake of (DOX + CUR)–PMs into A549/Adr cells was found to be associated with an energy-dependent, caveolae-mediated, and clathrin-independent mechanism. (DOX + CUR)–PMs helped to prolong the circulation of DOX or CUR as compared to the individual administration of DOX or CUR, and they exhibited high inhibiting efficiency against the growth of tumors and were able to reduce the side effects of DOX. Conclusion TPGS1000 and CUR could synergistically reverse DOX-resistance of A549/Adr cells. In vivo examinations confirmed that the micelles had the capability to increase the plasma concentration of DOX or CUR, as well as to prolong their respective blood circulation. These micelles were able to significantly inhibit tumor growth in Lewis lung carcinoma tumor-bearing mice while reducing the side effects of DOX. The micelles showed potential in the treatment of lung cancer.

piR-55490 inhibits the growth of lung carcinoma by suppressing mTOR signaling

Lung carcinoma is the most common human cancer with poor prognosis and has an increasing incidence in recent years. However, the related mechanism of lung cancer onset has not been completely explored. Piwi-interacting RNA (piRNA) is a type of noncoding small RNA with established function in germ cells, and interestingly, piRNA has also been shown to be implicated in cancer biology. In this study, piR-55490 was found to be silenced in lung carcinoma specimens and cell lines, compared with normal lung tissues and cells. Intriguingly, the expression level of piR-55490 is negatively associated with patients’ survival. Restoration of piR-55490 can reduce the proliferation rates of lung cancer cells, while piR-55490 suppression led to the gain in the proliferation rates. Animal model study showed that piR-55490 can suppress the growth of lung carcinoma xenograft. Further study revealed that piR-55490 suppressed the activation of Akt/mTOR pathway in lung cancer cells. Surprisingly, piR-55490 was found to bind 3′UTR of mTOR messenger RNA (mRNA) and induce its degradation in a mechanism similar to microRNA (miRNA). The introduction of an mTOR construct resistant to action of piR-55490 was able to abolish the effect of piR-55490 on lung cancer cells. In conclusions, we found that piRNA can contribute to the suppression of cancer cell phenotypes by directly targeting a oncogene mRNA. This finding facilitates our understanding of piRNA’s function and its association with human cancer.

miR-218 suppressed the growth of lung carcinoma by reducing MEF2D expression

Lung carcinoma is a deadly malignant disease with poor prognosis and increasing incidence in recent years. However, the molecular mechanism underlying the initiation and progression of lung cancer is still not completely elucidated. Recently, myocyte enhancer factor 2D (MEF2D) has been reported to promote the growth of liver cancer, but its implication in lung cancer is still unknown. This study is aimed to determine the role of MEF2D in lung carcinoma. Quantitative PCR (qPCR) and immunoblot assays showed that MEF2D was overexpressed in lung cancer tissues and cell lines, compared with the matched normal tissues and cell lines. Small interfering RNA (siRNA) suppression of MEF2D was able to reduce the proliferation, survival, and invasion of lung carcinoma cells. The transfection of MEF2D-expressing constructs into normal lung fibroblast cells promoted their proliferation and motility. The role of MEF2D in the growth of lung cancer was also confirmed in mice. Further study revealed that miR-218, which was underexpressed in lung carcinoma, was predicted to bind the 3′-untranslated region (UTR) of MEF2D mRNA. miR-218 was shown to suppress the activity of luciferase with MEF2D 3′-UTR. The changes in miR-218 levels affected the expression of MEF2D in lung cancer cells and normal fibroblast cells. There is also an inverse association between miR-218 abundance and MEF2D levels in the lung carcinoma specimen. Furthermore, the transfection of a plasmid that expressed MEF2D resistance to miR-218 regulation abolished the inhibitory effect of miR-218 on lung cancer cells. Collectively, MEF2D overexpression participated in the growth of lung cancers and its aberrant expression may result from the reduction of tumor suppressor miR-218.

Exposure to PM2.5 induces aberrant activation of NF-κB in human airway epithelial cells by downregulating miR-331 expression.

Exposure to particulate matter (PM) with an aerodynamic diameter≤2.5μm (PM2.5) induces reactive oxygen species (ROS) and pro-inflammatory cytokine production, leading to airway epithelial injury. However, the mechanisms underlying the toxicity of PM2.5 have not been clarified. Here, we show that exposure to PM2.5 induces sustained activation of the nuclear factor kappa B (NF-κB) signaling in human airway epithelial Beas-2B (B2B) cells. In addition, PM2.5 exposure significantly decreased miR-331 expression in B2B cells, which was abrogated by inhibition of ROS or phosphoinositide 3-kinase (PI3K)/Akt pathway. Induction of miR-331 overexpression attenuated the PM2.5 exposure-induced NF-kBp65 nuclear translocation, IL-6 and IL-8 expression in B2B cells. Furthermore, miR-331 targeted the inhibitor of NF-κB kinase beta (IKK-β) by down-regulating the IKK-β-regulated luciferase activity in HEK293 cells. Moreover, induction of miR-331 over-expression inhibited IKK-β expression while induction of IKK-β over-expression prevented the inhibition of miR-331 on the PM2.5 exposure-induced NF-kBp65 nuclear translocation, IL-6 and IL-8 expression in B2B cells. Therefore, PM2.5 exposure decreased miR-331 expression via the ROS/PI3K/Akt pathway, resulting in an increase in the IKK-β expression and sustained NF-κB activation in human airway epithelial cells. Our findings may provide new insights into the molecular mechanisms underlying the toxicity of PM2.5 exposure and aid in design of new therapeutic strategies to prevent PM2.5-induced toxicity.

Let-7a modulates particulate matter (≤ 2.5 μm)-induced oxidative stress and injury in human airway epithelial cells by targeting arginase 2

Epidemiological studies show that particulate matter (PM) with an aerodynamic diameter ≤ 2.5 μm (PM2.5) is associated with cardiorespiratory diseases via the induction of excessive oxidative stress. However, the precise mechanism underlying PM2.5‐mediated oxidative stress injury has not been fully elucidated. Accumulating evidence has indicated the microRNA let‐7 family might play a role in PM‐mediated pathological processes. In this study, we investigated the role of let‐7a in oxidative stress and cell injury in human bronchial epithelial BEAS2B (B2B) cells after PM2.5 exposure. The let‐7a level was the most significantly decreased in B2B cells after PM2.5 exposure. The overexpression of let‐7a suppressed intracellular reactive oxygen species levels and the percentage of apoptotic cells after PM2.5 exposure, while the let‐7a level decreased arginase 2 (ARG2) mRNA and protein levels in B2B cells by directly targeting the ARG2 3′‐untranslated region. ARG2 expression was upregulated in B2B cells during PM2.5 treatment, and ARG2 knockdown could remarkably reduce oxidative stress and cellular injury. Moreover, its restoration could abrogate the protective effects of let‐7a against PM2.5‐induced injury. In conclusion, let‐7a decreases and ARG2 increases resulting from PM2.5 exposure may exacerbate oxidative stress, cell injury and apoptosis of B2B cells. The let‐7a/ARG2 axis is a likely therapeutic target for PM2.5‐induced airway epithelial injury. Copyright

Strong evidence for LncRNA ZNRD1-AS1, and its functional Cis- eQTL locus contributing more to the susceptibility of lung cancer

Long noncoding RNAs (IncRNAs), involved in cancer biology, contributing to essential cancer cell functions such as proliferation, invasion, and metastasis, have received increasing attention recently. Human Zinc ribbon domain containing 1 (ZNRD1) has been confirmed to be involved in carcinogenesis and development of multiple cancers. ZNRD1-AS1, a lncRNA in the upstream region of ZNRD1 which could down-regulate the expression of ZNRD1, has been identified as a possible component in carcinogenesis. The underlying relations of ZNRD1-AS1 with lung cancer development and metastasis remain obscure. In current study, we first evaluated the expression ZNRD1-AS1 and ZNRD1 among lung cancer tissues and corresponding normal tissues, which showed higher expression of ZNRD1-AS1 and lower expression of ZNRD1. To reveal the underlying mechanisms, we then investigated the associations between ZNRD1 eQTLs SNPs in ZNRD1-AS1 and risk of lung cancer in Han Chinese populations. G allele of SNP rs9261204 was significantly associated with an increased risk of lung cancer when compared with A allele (OR: 1.45; 95% CI: 1.19–1.75; P = 1.06 × 10−4). A weaker, but similar effect was also observed in bladder cancer. SNP rs3757328 was also associated with increased risk of lung cancer (OR: 1.34; 95% CI: 1.07–1.67; P = 0.011). Our findings first confirmed the contribution of LncRNA ZNRD1-AS1 to the development of lung cancer in Asian population.

miR-144-5p Enhances the Radiosensitivity of Non-Small-Cell Lung Cancer Cells via Targeting ATF2

MicroRNAs (miRNAs or miRs) regulate gene expression at the posttranscriptional level and are involved in many biological processes such as cell proliferation and migration, stem cell differentiation, inflammation, and apoptosis. In particular, miR-144-3p is downregulated in various cancers, and its overexpression inhibits the proliferation and metastasis of cancer cells. However, the role of miR-144-5p in non-small-cell lung cancer (NSCLC), especially radiosensitivity, is unknown. In this study, we found that miR-144-5p was downregulated in NSCLC clinical specimens as well as NSCLC cell lines exposed to radiation. Enhanced expression of miR-144-5p promoted the radiosensitivity of NSCLC cells in vitro and A549 cell mouse xenografts in vivo. Furthermore, we identified activating transcription factor 2 (ATF2) as the direct and functional target of miR-144-5p using integrated bioinformatics analysis and a luciferase reporter assay. In addition, restoration of ATF2 expression inhibited miR-144-5p-induced NSCLC cell sensitivity to radiation in vitro and in vivo. Our findings suggest that deregulation of the miR-144-5p/ATF2 axis plays an important role in NSCLC cell radiosensitivity, thus representing a new potential therapeutic target for NSCLC.

Memory and Executive Screening for the Detection of Cognitive Impairment in Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is commonly associated with cognitive dysfunction, which is more apparent in severe OSA and impairs quality of life. However, the clinical screening methods for these impairments in OSA are still limited. In this study, we evaluated the feasibility of using the Memory and Executive Screening (MES) for assessing cognitive performance in OSA. Materials and Methods: Twenty‐four patients with nonsevere OSA and 36 patients with severe OSA participated in this study. All participants underwent comprehensive, laboratory‐based polysomnography and completed assessments of cognitive function, which included both the MES and the Beijing version of the Montreal Cognitive Assessment (MoCA‐BJ). Results: Both the total MES scores and 5 recall scores of the MES (MES‐5R) were significantly lower in the severe OSA group than those in the nonsevere OSA group. The patients with severe OSA performed worse on the memory subtests of the MES‐5R, especially on immediate recall. The sensitivity and specificity of the MES for identifying cognitive impairment in patients with OSA were 63.89% and 66.67%, respectively, for a cutoff value of <92 out of 100 points. An optimal cutoff between nonsevere and severe OSA was also set at 45 points (MES‐5R) and at 0.94 points (MES ratio). Compared with the MES, the MoCA‐BJ had similar sensitivity (61.11%) and specificity (66.67%). Conclusions: The MES is an acceptable tool for detecting cognitive dysfunction in patients with OSA. The sensitivity and specificity of the MES were similar to those of the MoCA‐BJ. The MES‐5R and total MES scores can assess the presence and severity of cognitive impairment in patients with severe OSA.

Associations of Overweight, Obesity and Related Factors with Sleep-Related Breathing Disorders and Snoring in Adolescents: A Cross-Sectional Survey

Background: Sleep-related breathing disorders (SRBD) have been identified as a major public health problem closely related to adolescent obesity. We aimed to estimate the prevalences of SRBD and snoring in adolescents in Changchun City, Northeastern China, and to evaluate the associated factors in this population. Methods: In total, 1955 adolescents aged 11–18 years were recruited in Changchun City using stratified cluster sampling. Parents and caretakers of children completed the questionnaires, which included demographic characteristics, anthropometric parameters and a pediatric sleep questionnaire (SRBD scale). Logistic regression was used to analyze the relationship between SRBD, snoring and other factors. Results: The prevalences of SRBD and snoring in our population were 3.7% and 3.3%, respectively, and the prevalences of overweight and obesity were 12.6% and 4.9%. Multivariate logistic regression showed that urban residence (OR = 2.356, 95%CI: 1.251–4.435) and post-term birth (OR = 3.275, 95%CI: 1.396–7.683) were significantly associated with SRBD. Preterm birth (OR = 2.255, 95%CI: 1.021–4.980) and parental education level of university and above (OR = 0.265, 95%CI: 0.083–0.850) were significantly associated with snoring. Overweight (OR = 2.063, 95%CI: 1.062–4.006) was also related to snoring. Conclusions: The prevalences of SRBD and snoring were similar to those reported in previous studies. Urban residence and post-term birth were important influencing factors for SRBD; overweight, highest parental education level (university and above) and preterm birth were key factors affecting snoring in adolescents.

6-O-Galloylpaeoniflorin Attenuates Cerebral Ischemia Reperfusion-Induced Neuroinflammation and Oxidative Stress via PI3K/Akt/Nrf2 Activation

6′-O-galloylpaeoniflorin (GPF), a galloylated derivative of paeoniflorin isolated from peony root, has been proven to possess antioxidant potential. In this present study, we revealed that GPF treatment exerted significant neuroprotection of PC12 cells following OGD, as evidenced by a reduction of oxidative stress, inflammatory response, cellular injury, and apoptosis in vitro. Furthermore, treatment with GPF increased the levels of phosphorylated Akt (p-Akt) and nuclear factor-erythroid 2-related factor 2 (Nrf2), as well as promoted Nrf2 translocation in PC12 cells, which could be inhibited by Ly294002, an inhibitor of phosphoinositide 3-kinase (PI3K). In addition, Nrf2 knockdown or Ly294002 treatment significantly attenuated the antioxidant, anti-inflammatory, and antiapoptotic activities of GPF in vitro. In vivo studies indicated that GPF treatment significantly reduced infarct volume and improved neurological deficits in rats subjected to CIRI, as well as decreased oxidative stress, inflammation, and apoptosis, which could be inhibited by administration of Ly294002. In conclusion, these results revealed that GPF possesses neuroprotective effects against oxidative stress, inflammation, and apoptosis after ischemia-reperfusion insult via activation of the PI3K/Akt/Nrf2 pathway.