SUMMARY Tonguesquamouscellcarcinoma(TSCC)isthemostcommontypeoforalcancerandis well known for its high rate of proliferation and lymph nodal metastasis.Exploring the underlying path-ways regulating TSCC could provide novel ideas for diagnosis and prognosis of TSCC patients,as well as molecular targets for treatment of TSCC.MicroRNAs (miRNAs)are small noncoding RNAs that inhibit gene expression through the 3′untranslated regions (3′UTRs)of their target messenger RNAs.They play crucial roles in numerous biological processes,including cancer progression.Although great efforts have been made,what role miRNAs may play in the early detection and diagnosis of TSCC is not fully under-stood .Recently,our team has performed a series of basic and clinical researches in an attempt to investi-gate the relationships between miRNA expressions and prognosis of patients with TSCC and the mecha-nisms under regulation of TSCC.The results showed that miR-1 95,miR-34a,miR-29b,miR-375 and miR-26a could inhibit TSCC cells progression and development via a sophisticated network of genes.Spe-cifically,the anti-tumor effects of miR-1 95 in TSCC may be partially mediated by its inhibition of Cy-clinD1 and Bcl-2 expression.The expression of miR-34a could inhibit migration and invasion of TSCC cell lines via targeting MMP9 and MMP1 4.The function of miR-29b may be through the miR-29b/Sp1 /PTEN/AKT axis.Overexpression of miR-375 inhibited Sp1 expression by targeting the 3′untranslated re-gion of the Sp1 transcript.MEG3 and miR-26a inhibited TSCC cell proliferation,cycle progression and promoted cell apoptosis and miR-26a could increase the MEG3 expression through reduction of the ex-pression of DNMT3B in TSCC.In light of the role of those miRNAs in diagnosis and prognosis of TSCC, we reported that decreased miR-1 95 and miR-375 expression was associated with poor overall survival rate of the TSCC patients,while miR-34a expression was negatively correlated with cervical lymph node me-tastases.Furthermore,combined low expression levels of miR-26a and MEG3 emerged as an independent prognostic factor for poor clinical outcomes in TSCC patients,suggesting that combined miR-26a and MEG3 expression might prove useful as an independent biomarker of clinical prognosis among TSCC pa-tients.

Objective To construct eukaryotic expressing vector of mouse soluble CD160 and stably transfect into CHO cells for eukaryotic expression.Methods Recombinant soluble CD160(rsCD160) was constructed by gene recombination.Total RNA was extracted from the spleen of C57BL/6 mice.cDNA was amplified for the soluble form of CD160.Then,the PCR product was cloned tO pcDNA3.1 and pEGFP-N1.The recombinant plasmid was identified by restriction map and sequence analy-sis.The soluble CDl 60 expression in CHO cells transfected with recombinant psCDl 60 was verified by RT-PCR and Westernblot.The binding ability of psCD160 tO its ligand was detected by FACS.Results 520 bp mouse soluble CD160 gene was obtained.Recombinant mouse psCD160 was successfully constructed.After transfection,soluble CD160 expression in the culture supernatant of CHO cells was successfully detected.FACS analysis indicated that soluble CD160 could bind tO its ligand.Conclusion Recombinant mouse psCD160 is successfully constructed,which will benefit our further study on soluble CD160 for immune therapy against tumor in the future experiments.

Objective:To investigate the clinicopathological features, and diagnostic and differential diagnostic characteristics of extranodal nasal type natural killer/T-cell lymphoma (ENKTCL) of the digestive system.Methods:Thirteen cases of ENKTCL in the digestive system were collected at the Henan Provincial People′s Hospital, Zhengzhou, China, from August 2000 to August 2020. The histopathological, immunohistochemical and in situ hybridization features were analyzed, as well as those of T-cell receptor (TCR) gene rearrangement in some cases. The patients were followed up.Results:There were 11 males and 2 females. The age ranged from 28 to 80 years (median=53 years). Seven cases were present in the colorectum, and 3 cases were present in the small intestine. The other three cases were in stomach, gallbladder and liver (one case each). The main clinical symptoms were fever, and abdominal pain, often accompanied by fatigue, diarrhea, hematochezia, elevated serum albumin, elevated lactate dehydrogenase, and increased peripheral blood EB virus DNA copy. Histologically, the tumor accompanied by a heavy admixture of inflammatory cells (small lymphocytes, plasma cells and histiocytes). There was diffuse dense tumor cell infiltrate, with prominent coagulative necrosis. The lymphomatous infiltrate had angiocentric and angio-necrotic changes. Immunohistochemically, lymphoid cells expressed CD3 in all cases. Some of them showed weakened/absent other T cell markers, while all of them expressed CD56 except 1 case. A few of the cases showed CD4 -/CD8 + killer T cell phenotypes. In situ hybridization showed EB virus encoded RNA (EBER) was positive in all cases. Clonal TCR gene rearrangement was not detected in all 7 cases tested. The median survival time was 9 months. Conclusions:ENKTCL of the digestive system is extremely rare. It often predisposes the patients to acute abdomen such as perforation of the gastrointestinal tract. The treatment outcomes are dismal, and the prognosis is poor. Clinical and imaging studies are often non-specific. It is also easy to be misdiagnosed as non-specific ulcers. Combined with immunohistochemistry, in situ hybridization and TCR gene rearrangement analysis and better understanding of this tumor′s clinicopathological characteristics can help improve its diagnosis and early treatment.

Objective:To investigate the effect of systemic lupus erythematosus (SLE) on the status of hepatitis B virus (HBV) infection, and provide data for clarifying the relationship between autoimmunity and infection.Methods:SLE patients in the department of rheumatology and immunology of the First Affiliated Hospital of Xi'an Jiaotong University from January 2016 to December 2019 were screened. A retrospective case-control study was carried out. SLE patients with positive hepatitis B surface antigen (HBsAg) were gender and age matched with chronic hepatitis B (CHB) in a 1∶4 ratio. Chi-square test was used to compared the positive rates of hepatitis B e antigen (HBeAg) and Paired-Samples t test or Signed rank Wilcoxon test was used to compare the HBV DNA load and HBsAg titer. Results:The positive rate of HBsAg in SLE patients was lower than the prevalence rate of HBsAg in general population in the second Chinese National Hepatitis Seroepidemiological Survey in 2006 [2.2%(27/1 227) vs 7.2%], but the positive rate of HBcAb was not obviously different from that in general population in China [33.9%(416/1 227) vs 34.1%]. Compared with matched CHB patients, the positive rate of HBeAg [37.0%(10/27) vs 58.3%(63/108), χ2=3.94, P=0.047], the HBV DNA load [0(0, 3.7) lg U/ml vs 4.8(2.2, 3.7) lg U/ml, Z=-5.37, P<0.001] and HBsAg titer [(2.0±1.5) lg U/ml vs (3.3±1.1) lg U/ml, t=-4.26, P<0.001] in SLE patients were lower. Conclusion:The HBV infection status of SLE patients is different from that of patients with chronic hepatitis B and the HBV infection is more likely to be controlled.

Objective:To investigate the role and mechanism of mitochondrial DNA N6-methyladenine (6mA) in the hippocampal neurons in vascular cognitive impairment.Methods:(1) In vivo experiments: SPF male rats were randomly divided into sham-operated group and chronic cerebral hypoperfusion (CCH) group ( n=12). CCH models in the CCH group were established by ligating bilateral carotid arteries, while rats in the sham-operated group were only bilaterally dissected without ligation. Exploratory ability was detected by open field test 50 d after modeling, cognitive function was evaluated by novel object recognition test 51-53 d after modeling, and learning and memory abilities were tested by Morris water maze 54-59 d after modeling. And then, rats were sacrificed; ATP concentration and reactive oxygen species (ROS) level in the hippocampal tissues were detected, and neuron apoptosis in the hippocampal CA1 area was detected by TUNEL. (2) In vitro experiments: HT-22 cells were divided into normal control (NC) group, oxygen-glucose deprivation (OGD) group, OGD+siControl group, and OGD+siMETTL4 group. Cells in the NC group were cultured routinely, cells in the OGD group were subjected to low sugar and low oxygen for 12 h, and cells in the OGD+siControl group and OGD+siMETTL4 group were, respectively, transfected with NC-siRNA or METTL4-siRNA after being subjected to low sugar and low oxygen for 12 h. Mitochondria morphology was observed by transmission electron microscopy, ROS was detected by flow cytometry, mitochondria membrane potential was detected by JC-1 fluorescent staining, and mitochondrial complex I and III activity was detected by kit. (3) In vivo and in vitro experiments: METTL4 and DNA 6mA expressions in neuronal mitochondria of rat hippocampal tissues and mitochondria of HT-22 cells were detected by immunofluorescent staining and Western blotting. Results:(1) CCH rats had cognitive impairment: compared with the sham-operated group, CCH group had significantly increased frequency of entering the central area and reduced time in exploring new objects in open field experiment,and significantly decreased frequency of crossing the platform and prolonged escape latency in water maze experiment ( P<0.05). Compared with rats in the sham-operated group, rats in the CCH group had significantly decreased hippocampal ATP content ([18.820±1.177] nmol/L vs. [10.190±0.519] nmol/L) and increased ROS content ([4 488.00±255.70] AU vs. [11 644.00±530.20] AU, P<0.05). TUNEL results showed that the number of apoptotic neurons in the hippocampal CA1 area of CCH group was obviously increased than that in sham-operated group. Immunofluorescent staining results showed that 6mA and METTL4 mainly distributed in the mitochondria of hippocampal neurons in CCH group, and the 6mA and METTL4 expressions were obviously increased compared with those in the sham-operated group. Western blotting results showed that METTL4 expression in the hippocampal mitochondria of CCH group was significantly higher than that in the sham-operated group (1.729±0.168 vs. 1.000±0.000). (2) In vitro experiment: under transmission electron microscope, compared with the NC group, HT-22 cells in the OGD group showed obvious mitochondrial ridge disappearance, membrane rupture and vacuolation. Compared with the OGD group, the OGD+siMETTL4 group had significantly increased ATP production, decreased mtROS production, increased mitochondrial membrane potential, and increased mitochondrial complex I and III activities ( P<0.05). Immunofluorescent staining results showed that the mtDNA 6mA and METTL4 expressions in the OGD group were obviously higher than those in the NC group, and both mainly expressed in the mitochondria; mtDNA 6mA expression in the OGD+siMETTL4 group was obviously lower than that in OGD group. Western blotting results showed that METTL4 expression in the OGD+siMETTL4 group was significantly higher than that in the OGD group (1.578±0.261 vs. 2.970±0.280). Conclusion:Specific high expression of methylase METTL4 in hippocampal neurons of rats with cognitive impairment after CCH promotes the increased mtDNA 6mA expression and leads to mitochondrial energy metabolism disorders and increased ROS, which is speculated to be one of the mechanisms causing vascular cognitive impairment.