Poly(A)-specific ribonuclease protein promotes the proliferation,invasion and migration of esophageal cancer cells

BACKGROUND Bioinformatics analysis showed that the expression of the poly(A)-specific ribonuclease(PARN)gene in gastric cancer,head and neck squamous cell carcinoma,melanoma,cervical cancer and lung squamous cell carcinoma tissues was significantly higher than that in normal tissues and was associated with high stage and poor prognosis.The expression of the PARN gene in esophageal cancer(EC)tissue is also significantly higher than that in normal tissues,but the effect of PARN on the proliferation,migration and invasion of EC cells remains unclear.AIM To investigate the relationship between PARN and the proliferation,migration and invasion of EC cells.METHODS The EC tissues of 91 patients after EC surgery and 63 paired precancerous healthy tissues were collected.PARN mRNA levels were measured using a tissue microarray,and the PARN expression level was evaluated using immunohistochemistry to analyze the relationship between PARN expression and clinicopathologic features as well as the survival and prognosis of patients.In addition,the effects of PARN gene knockout on tumor cell proliferation,invasion and migration were studied by using shRNA during the in vitro culture of EC cell lines Eca-109 and TE-1,and the effects of the PARN gene on tumor growth in vivo were verified by a xenotransplantation nude mice model.RESULTS The expression of PARN in EC tissues was higher than that in adjacent normal tissues,and the level of PARN expression was significantly positively correlated with lymphatic metastasis.Patients with high PARN levels had poor overall survival.BIM,IGFBP-5 and p21 levels were significantly increased in the PARN knockout group,while the expression levels of the antiapoptotic proteins Survivin and sTNF-R1 were significantly decreased in the apoptotic antibody array data.In addition,the expression levels of Akt,p-Akt,PIK3CA and CCND1 in the downstream signaling pathway regulating EC progression were significantly decreased.The culture of EC cell lines confirmed that the apoptosis rate of EC cells was significantly increased,the growth and proliferation of tumor cells were significantly inhibited,and the invasion and migration ability of tumor cells were significantly decreased after PARN gene knockout.In vivo experiments of BALB/c nude mice transfected with Eca-109 cells expressing control shRNA(sh-NC)and PARN shRNA(sh-PARN)showed that the tumor volume and weight of nude mice treated with sh-PARN were significantly decreased compared with those of nude mice treated with sh-NC,indicating that PARN knockdown significantly inhibited tumor growth in vivo.CONCLUSION PARN has antiapoptotic effects on EC cells and promotes their proliferation,invasion and migration,which is associated with the development of EC and poor patient prognosis.PARN may become a potential target for the diagnosis,prognosis prediction and treatment of EC.

2种麻醉剂对红耳龟麻醉时效及听力的影响

为研究水合氯醛和戊巴比妥钠对红耳龟Trachemys scripta elegans麻醉效果及听力的影响,选取雌性(体质量:911.39 g±61.37 g,n=16)和雄性(体质量:871.06 g±76.64 g,n=16)红耳龟为实验对象,分别注射剂量为6 mL·kg^(−1)的5%水合氯醛和3 mL·kg^(−1)的0.5%戊巴比妥钠,记录了麻醉起效时间和维持时间。采用听性脑干反应测定了红耳龟的听觉阈值和反应时间。结果发现:水合氯醛和戊巴比妥钠的麻醉起效时间和维持时间在两性间均无显著差异(P>0.05),但水合氯醛的麻醉起效时间(66.00 min±3.71 min)和维持时间(406.44 min±11.32 min)均显著长于戊巴比妥钠的麻醉起效时间(32.13 min±2.91 min)和维持时间(183.38 min±6.26 min)(P<0.05)。采用水合氯醛和戊巴比妥钠麻醉的相同性别红耳龟的听觉阈值和反应时间均无显著差异(P>0.05)。水合氯醛和戊巴比妥钠对红耳龟均具有较好的麻醉效果,且水合氯醛具有较长的麻醉维持时间。2种麻醉剂均可用于开展红耳龟听力的相关研究。本研究首次报道了5%水合氯醛和0.5%戊巴比妥钠对红耳龟的麻醉时效及听力测试结果的影响,为龟类听觉等相关生理学方面的研究提供了依据。

Effect of fragile histidine triad gene transduction on proliferation and apoptosis of human hepatocellular carcinoma cells

AIM:To evaluate the inhibitory effects of human fragile histidine triad(FHIT) gene on cell proliferation and apoptosis in human hepatocellular carcinoma line Hep3B in vitro. METHODS:A recombinant pcDNA3.1(+) /FHIT including the functional region of FHIT gene was constructed and transferred into human hepatocellular carcinoma cells in vitro. mRNA and protein expression of the FHIT gene in the transfected cells was detected by RT-PCR and Western blot,respectively. The effect of FHIT on proliferation was detected by MTT assay. Changes in cell cycle and apoptosis were assayed by flow cytometry. Five mice received subcutaneous transplantation of Hep3B-FHIT;5 mice received subcutaneous transplantation of normal Hep3B and Hep3B-C as controls. The body weight of nude mice and tumor growth were measured. RESULTS:RT-PCR and Western blot analysis showed that the expression level of FHIT-mRNA and FHIT protein was higher in Hep3B cells after infection withpcDNA3.1(+) /FHIT. The growth of Hep3B cells treated with pcDNA3.1(+) /FHIT was significantly inhibited. The pcDNA3.1(+) /FHIT-transfected Hep3B cells showed a significantly higher cell rate at G0-G1 phase and increased apoptosis in comparison with controls(P < 0.05) . The growth of transplanted tumor was inhibited markedly by FHIT. Tumors arising from the Hep3B-FHIT cells occurred much later than those arising from the Hep3B and Hep3B-C cells. The growth of Hep3B-FHIT cells was slow and the tumor volume was low. CONCLUSION:Transduction of FHIT gene inhibits the growth of human hepatocellular carcinoma cells and induces cell apoptosis in vivo and in vitro.

Sonocatalytic Damage of Bovine Serum Albumin (BSA) in the Presence of Nanometer Titanium Dioxide (TiO_2) Catalyst

The sonocatalytic damage of bovine serum albumin （BSA） was studied in the presence of nanometer titanium dioxide （TiO2） powders by low frequency （80 kHz） ultrasound. The destruction of secondary structure and change of α-helical structure of BSA were reflected by ultraviolet （UV） and circular dichroism （CD） spectroscopies.

Non-ionizing radiation-induced cellular senescence and age-related diseases

Cellular senescence has emerged as an important contributor to aging and age-related diseases.Non-ionizing radiation(NIR),including ultraviolet radiation and electromagnetic fields,has been increasingly recognized as a key inducer of premature senescence.In this review,we discuss the molecular mechanisms of NIR-induced cellular senescence and its effects on aging and age-related diseases.We also summarize the modulation strategies for NIR-induced cellular senescence.A better understanding of the complex relationship between nonionizing radiation,cellular senescence and age-related pathology may lead to interventions to ameliorate radiation damage and delay aging.Further research is still needed to elucidate the precise mechanisms,dose-response effects,and to develop protective strategies against radiation-induced senescence.

Biophoton signaling in mediation of cell-to-cell communication and radiation-induced bystander effects

This paper presents a comprehensive overview of the historical trajectory and development in biophoton studies over the past 100 years,with a particular focus on the recent progress regarding the pivotal role of biophoton in mediating radiation-induced bystander effects(RIBE).The exploration of biophoton mystery starts from the initial observation of mitogenetic radiation and continues to develop to the contemporary science of biophotonics.The properties and underlying mechanisms of biophoton emission are described with illustrative examples from diverse biological systems such as plants,animals and humans.The conclusive evidence of cell-to-cell commu-nication facilitated by biophoton signaling is presented,followed by an elaborate interpretation of potential mechanisms through which biophoton mediates RIBE.The engagement of mitochondria and exosomes in this process is extensively clarified,by highlighting their significant roles in biophoton-mediated RIBE.The advances in biophoton research in respect of bystander response to ionizing radiation may offer profound insights into radiobiology and provide for possible future applications as well in radiation medicine and protection.

Solidification Behavior and Segregation of Re-containing Cast Ni-base Superalloy with Different Cr Content

The effect of chromium（Cr） on solidification and segregation behavior of Re-containing cast Ni-base superalloys was investigated by optical microscopy（OM）,scanning electron microscopy（SEM） and electronic probe micro analysis（EPMA）.The results show that Cr has significant effect on solidification and segregation behavior of Re-containing cast Ni-base superalloys.The liquidus and solidus of alloy decrease with increasing Cr in alloys.The segregation coefficient（K） of Mo increases and that of W and Re decreases gradually with increasing Cr element.

Hot deformation behavior and microstructure evolution of an Fe–30Cr–2Mo ultra-pure super ferritic stainless steel

The hot deformation behavior and microstructure evolution of an Fe–30Cr–2Mo ultra-pure super ferritic stainless steel were investigated at the temperature range of 950–1150℃ and strain rate varying from 0.01 to 10 s^(−1).A strain compensated constitutive equation based on the Arrhenius-type model was established to predict the flow stress.The hot processing map based on the dynamic materials model was achieved to identify the optimum processing parameters.In addition,the features of microstructure evolution combined with the processing map were systematically investigated.The experimental results revealed that the flow stress increased with decreasing deformation temperature or increasing strain rate.Dynamic recovery was confirmed to be the predominant softening mechanism.The values of flow stress predicted by the strain compensated constitutive equation agreed well with the experimental values.The extent of dynamic recrystallization and recrystallized grain size increased with increasing deformation temperature or decreasing strain rate,and the continuous dynamic recrystallization was attributed to be the predominant mechanism of recrystallization during hot deformation.The optimum hot working parameters were determined to be the deformation temperature of 1070–1150℃ and strain rate of 0.1–1 s^(−1) with a peak power dissipation efficiency of 42%.

Thermal fatigue behavior of K125L superalloy

The thermal fatigue behavior of K125 L superalloy at the peak temperature of 1,050 °C was investigated by optical microscope（OM）, X-ray diffraction（XRD）, and scanning electron microscope（SEM）. The experimental results show that the crack initiation sites of tested alloys are at the V-notch tip and the V-notch tip propagates by way of continuous cracking along grain boundaries. The formation of high-temperature oxides and MC carbides accelerates the crack propagation, and no secondary carbides precipitate out. Oxides between cracks are mainly the Al2O3 as well as Cr_2O_3, and carbides are Ta-rich and Tirich MC carbides.

Opinion on reconsideration of lung cancer risk from domestic radon exposure

Two extensive collaborative meta studies including 13 residential case-control studies from Europe and 7 from North America have demonstrated that domestic radon clearly poses a risk for lung cancer at exposure levels approaching those for underground miners.An excess risk for lung cancer of 0.08–0.16 per 100 Bq/m3 increase in radon concentration was obtained,with a positive trend of increased relative risk at above 200 Bq/m3.However,estimation of the cancer risk associated with domestic radon obtained by the pooling of multiple casecontrol studies has led to inaccuracies of the derived risk estimates in the low dose range,mainly due to smoking misclassification bias,uncertainties with respect to radon dosimetry,the histopathological characterization of lung cancers,as well as confounding by co-exposures with tobacco smoke and other indoor air pollutants.Together with a lack of biological plausibility,these deficiencies have a negative impact on the reliability of reported statistical relations between radon exposure and lung cancer at concentrations below 200 Bq/m3.It is vital that costly remedial actions to reduce domestic radon exposure are based on a scientifically robust risk assessment,and in view of aforementioned flaws,the hitherto proposed risk estimates need to be reconsidered.

Aging and age-related health effects of ionizing radiation

There is increasing evidence showing a close relationship between human radiation sensitivity and age-related health effects including cancer.Individuals exposed to ionizing radiation(IR)are the most radiosensitive at early ages,and decrease in radiation sensitivity until maturity,but increase again at older ages,as measured with incidence of carcinogenic events.This article reviews the historical and current status of aging and age-related health effects induced by IR,with results obtained from epidemiological,animal and in vitro studies over the last 20 years.Mechanistic studies underlying these radiation-induced effects are summarized in terms of DNA damage and genomic instability,telomere erosion,oxidative stress and inflammation,as well as radiation-associated cellular senescence and epigenetic alterations.Since individual radiosensitivity changes with age and the life expectancy of population rises steadily,there is a pressing need for a better understanding of the aging-radiation exposure association so as to improve radiation protection in clinical practice.