OBJECTIVE To investigate the mechanism of disruptor of telomeric silencing 1-like(DOT1L)on epithelial mesenchymal transition(EMT)in laryngeal squamous cell carcinoma(LSCC)via Notch1 signal pathway.METHODS Fresh tumor tissues and adjacent normal tissues from 30 pathologically confirmed LSCC patients were selected.The positive expression rates of DOT1L and its catalytic product H3K79me3 were detected by immunohistochemistry staining,the relative mRNA expression levels of DOT1L and H3K79me3 were measured by qRT-PCR.The human LSCC cell line TU686 was selected and divided into blank control group,over-expression group,and low-expression group.After 48 hours of cultivation,cell proliferation rate was measured using MTT method,cell apoptosis rate was measured using flow cytometry,and the relative expression levels of Notch1,E-cadherin,N-cadherin,and Vimentin proteins were detected using Western blot.RESULTS 1.Compared with normal tissues adjacent to cancer,the positive expression rates[(41.5±8.9)%vs.(18.3±3.6)%,t=56.963,P＜0.001;(40.5±7.7)%vs.(10.2±2.3)%,t=96.635,P＜0.001]and mRNA expression levels[(0.69±0.13)vs.(0.13±0.09),t=102.302,P＜0.001;(0.42±0.19)vs.(0.09±0.03),t=85.659,P＜0.001]of DOT1L and H3K79me3 in tumor tissues were significantly increased.2.Compared with the blank control group,cell proliferation rate in the over-expression group was significantly higher(t=45.628,P＜0.001),while apoptosis rate was lower(t=40.125,P＜0.001),Notch1,N-cadherin,and Vimentin proteins expressions were increased,E-cadherin was decreased(t=22.524,30.263,45.629,27.859,P＜0.001).The cell proliferation rate in the low expression group was significantly decreased(t=33.427,P＜0.001),but apoptosis rate was increased(t=78.529,P＜0.001),levels of Notch1,N-cadherin,and Vimentin proteins were lower,E-cadherin was higher,too(t=19.864,23.524,28.957,33.426,P＜0.001).CONCLUSION DOT1L is highly expressed in LSCC,affecting the methylation level of histones,thereby regulating cell proliferation,apoptosis,and EMT behavior.DOT1L is expected to become a new site for tumor targeted intervention.

OBJECTIVE：To st udy the effects of α7 nicotinic acetylcholine receptor agonists （PNU282987）on improving cardiac remodeling of mice and Janus kinase 2/signal transducer and activator of transcription 3（JAK2/STAT3）signaling pathway. METHODS：Male Kunming mice were randomly divided into normal control group ，model group ，propranolol group （positive control，i.g. 40 mg/kg）and PNU 282987 low-dose，medium-close and high-dose groups （intraperitoneal injection of 0.5，1.0，3.0 mg/kg），with 10 mice in each group. Except for the normal control group ，mice in the other groups were given isoproterenol （ISO，30 mg/kg） subcutaneously for 7 days to induce the cardiac remodeling model. After 30 minutes of ISO injection ， administration groups were given relevant liquid ，once a day ，for 7 consecutive days. Twelve hours after last administration ，the left ventricular ejection fraction （EF）and left ventricular short axis shortening rate （FS）of mice in each group were measured ，and the whole heart mass index （HMI）was calculated ；the pathological changes of myocardium were observed. The serum contents of lactate dehydrogenase （LDH），creatine kinase （CK），tumor necrosis factor α（TNF-α），interleukin 6（IL-6），the protein expression of intercellular adhesion molecule 1（ICAM-1）and adhesion molecule 1（VCAM-1）were also determined. The ratios of p-JAK2/JAK2，p-STAT3/STAT3 in myocardial tissue were detected. RESULTS ：Compared with normal control group ，EF and FS of model group were significantly reduced ，HMI，the contents of LDH，CK，TNF-α and IL-6，the protein expression of ICAM- 1 and VCAM- 1，the ratio of p-JAK 2/JAK2 and p-STAT 3/STAT3 were increased significantly （P＜0.05 or P＜0.01）； blue collagen deposition in the interstitium of myocardium was obvious，and the degree of fibrosis was severe. Compared with model group ， the EF and FS of the mice in the medium-dose and high-dose groups were increased significantly ， HMI （except for PNU 282987 medium-dose group ），the contents of LDH （except for PNU 282987 medium-dose group ），CK，TNF-α and IL-6，the protein expression of ICAM- 1 and VCAM- 1，the ratio of p-JAK 2/JAK2 and p-STAT 3/STAT3 were decreased significantly （P＜0.05 or P＜ 0.01）；blue collagen deposition in the myocardial interstitium was significantly reduced ，and the degree of myocardial fibrosis was significantly reduced. There was no significant difference in the comparison of the above indicators in PNU 282987 low-dose group （P＞0.05）. CONCLUSIONS ：PNU282987 can improve cardiac remodeling of mice ，the mechanism of which may be associated with inhibiting JAK 2/STAT3 signaling pathway.

OBJECTIVE To explore the protective effect and mechanism of Longshengzhi capsules on cerebral ischemia- reperfusion injury in rats. METHODS The model of middle cerebral artery occlusion （MCAO） was established by using the improved thread occlusion method. The experiment was divided into six groups： sham surgery group （only separating blood vessels without inserting thread plugs， given the same volume of normal saline）， model group （modeling， given the same volume of normal saline）， nimodipine group （positive control， modeling， dose of 20 mg/kg）， and low-dose， medium-dose， and high-dose groups of Longshengzhi capsules （modeling， doses of 0.72， 1.44 and 2.88 g/kg， respectively）， with 10 mice in each group. Each group was given corresponding medication solution/normal saline by gavage， once a day， for 7 consecutive days. One hour after the last administration， the Zea Longa scoring method was used to score the neurological deficits in each group of rats， and the ABC enzyme-linked immunosorbent assay was used to detect the serum levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in rats； TTC staining was used to observe the volume of cerebral infarction in rats and calculate the cerebral infarction volume ratio. Hematoxylin eosin staining was used to observe the pathological changes in the brain tissue of rats. Immunohistochemical staining was used to detect the positive expression of NLRP3 protein in the brain tissue of rats. Real-time fluorescence quantitative PCR was used to detect mRNA relative expressions of Toll-like receptor 4 （TLR4） and nuclear factor-κB （NF-κB） in the brain tissue of rats. Western blot assay was adopted to detect the relative expressions of TLR4， NLRP3 and phosphorylated NF-κB （p-NF-κB） protein in the brain tissue of rats and its intracellular NF-κB protein. RESULTS Compared with the sham surgery group， the neural dysfunction score， serum levels of TNF-α and IL-6， cerebral infarction volume ratio， relative expression levels of NF-κB and TLR4 mRNA， as well as protein relative expressions of TLR4， NLRP3 and p-NF-κB in the brain tissue， and relative protein expression of intracellular NF-κB were increased significantly in the model group （P＜0.01）； the enlarged gap and significant edema were observed in cortical nerve cells of brain tissue in rats， with a large amount of inflammatory cell infiltration； the positive expression of NLRP3 protein in brain tissue of rats obviously increased. Compared with the model group， the levels of the above indicators in the medium-dose and high-dose groups of Longshengzhi capsules， as well as the Nimodipine group， were reversed to varying degrees， and most differences were statistically significant （P＜0.05 or P＜0.01）； the pathological morphology observation showed a significant improvement， and the positive expression of NLRP3 protein in the brain tissue of rats was obviously reduced. CONCLUSIONS Longshengzhi capsules may inhibit TLR4/NF-κB/NLRP3 signaling pathway and neuroinflammatory response， thereby achieving a protective effect against cerebral ischemia-reperfusion injury in rats.