Higher Prevalence of Generalized Pustular Psoriasis in Asia? A Population-Based Study Using Claim Data in China and a Systematic Review.

BACKGROUND: Few studies have reported the burden of generalized pustular psoriasis (GPP), a severe and potentially life-threatening skin disease, especially at a national level. OBJECTIVES: The aim of this study is to estimate the nationwide burden of GPP in China and make a systemic review of the published data. METHODS: We conducted a population-based study using Urban Basic Medical Insurance in China from 2012 to 2016. GPP cases were identified by primary diagnoses including the international classification of Diseases codes (ICD-10: L40.1 and ICD-9: 694.3). A systematic review was conducted using relevant databases up to January 2022. RESULTS: The crude prevalence and incidence of GPP in 2016 were 1.403 (95% confidence interval [CI]: 1.115-1.691) and 0.629 (95% CI: 0.483-0.775) per 100,000 person-years, respectively. The rates were higher in males than in females for both prevalence (1.429 vs. 1.135) and incidence (0.635 vs. 0.520). The prevalence and incidence showed a bimodal age distribution, with the first peak occurring in the 0- to 3-year age-group and the second peak occurring in the 30- to 39-year age-group. The per capita total cost per year for 1 patient with GPP was 609.26 (± 45.77) US dollars. Seven studies were identified in a systematic review, according to which the prevalence (per 100,000) of GPP tended to be higher in Asian countries (0.746-8.178 in Japan and 12.230 in Korea) than in France (0.176), Sweden (6.25), and Brazil (0.7). CONCLUSIONS: This is the largest study concerning the disease burden of GPP, and in this study, the prevalence seemed to be higher in Asia. Although the direct economic burden of GPP did not seem high during the study period, the future usage of biologics and the humanistic burden should also be considered for policy-related decision-making.

Vacuum Based Gas Sensing Material Characterization System for Precise and Simultaneous Measurement of Optical and Electrical Responses.

Gas sensing performance characterization systems are essential for the research and development of gas sensing materials and devices. Although existing systems are almost completely automatically operated, the accuracies of gas concentration control and of pressure control and the ability to simultaneously detect different sensor signals still require improvement. In this study, a high-precision gas sensing material characterization system is developed based on vacuum technology, with the objective of enabling the precise and simultaneous measurement of electrical responses. Because of the implementation of vacuum technology, the gas concentration control accuracy is improved more than 1600 times, whereas the pressure of the test ambient condition can be precisely adjusted between vacuum and 1.2 bar. The vacuum-assisted gas-exchanging mechanism also enables the sensor response time to be determined more accurately. The system is capable of performing sensitivity, selectivity, and stability tests and can control the ambient relative humidity in a precise manner. More importantly, the levels of performance of three different optical signal measurement set-ups were investigated and compared in terms of detection range, linearity, noise, and response time, based on which of their scopes of application were proposed. Finally, single-period and cyclical tests were performed to examine the ability of the system to detect optical and electrical responses simultaneously, both at a single wavelength and in a spectral region.

Two new quinic acid derivatives from the leaves of Schisandra chinensis.

Two new (1-2) and three known quinic acid derivatives (3-5) were isolated from the leaves of Schisandra chinensis (Turcz) Baill. The structures of the compounds were determined by spectroscopic methods, especially the NMR techniques, and also by comparison with reported data in the literature. The cytotoxicity activities of these compounds were evaluated on human tumor cell lines LN229 and three of them showed a certain activity.

Pyroglutamate Aminopeptidase I Promotes Hepatocellular Carcinoma via IL-6/STAT3 Activation as Revealed by a Specific Biosensor.

As a global health challenge, hepatocellular carcinoma (HCC) is strongly associated with chronic inflammation. Targeting inflammation, particularly inflammatory factors, is regarded as an important strategy for HCC diagnosis and treatment. Pyroglutamic aminopeptidase I (PGP-I), a common exopeptidase, was recently identified as a novel inflammatory cytokine in cells. However, whether PGP-I is involved in HCC development and can be regarded as a biomarker remains unclear. To address this issue, endogenous PGP-I was imaged in live cells and in vivo, and the related biochemical and pathological processes were analyzed accordingly with a newly developed fluorogenic PGP-I biosensor. Bioimaging with the specific biosensor demonstrated the aberrant expression of PGP-I in HCC cell lines and tumor-bearing nude mice. Moreover, overexpression of PGP-I in HCC cells promoted tumor progression, whereas knockdown of PGP-I significantly suppressed tumor cell growth and migration. The activity of PGP-I was further identified to be highly related to the phosphorylation of STAT3, which could be impeded by the natural product parthenolide. Collectively, these findings suggest that PGP-I, which can promote hepatocellular tumor progression through the classical inflammation-/tumor-related IL-6/STAT3 pathway, may serve as a potential HCC biomarker and therapeutic target.

HBx facilitates ferroptosis in acute liver failure via EZH2 mediated SLC7A11 suppression.

BACKGROUND: Acute liver failure (ALF) is a syndrome of severe hepatocyte injury with high rate of mortality. Hepatitis B virus (HBV) infection is the major cause of ALF worldwide, however, the underlying mechanism by which HBV infection leads to ALF has not been fully disclosed. METHODS: D-GalN-induced hepatocyte injury model and LPS/D-GalN-induced ALF mice model were used to investigate the effects of HBV X protein (HBx) in vitro and in vivo, respectively. Cell viability and the levels of Glutathione (GSH), malondialdehyde (MDA) and iron were measured using commercial kits. The expression of ferroptosis-related molecules were detected by qRT-PCR and western blotting. Epigenetic modification and protein interaction were detected by chromatin immunoprecipitation (ChIP) assay and co-immunoprecipitation (co-IP), respectively. Mouse liver function was assessed by measuring aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The histological changes in liver tissues were monitored by hematoxylin and eosin (H&E) staining, and SLC7A11 immunoreactivity was assessed by immunohistochemistry (IHC) analysis. RESULTS: D-GalN triggered ferroptosis in primary hepatocytes. HBx potentiated D-GalN-induced hepatotoxicity and ferroptosis in vitro, and it suppressed SLC7A11 expression through H3K27me3 modification by EZH2. In addition, EZH2 inhibition or SLC7A11 overexpression attenuated the effects of HBx on D-GalN-induced ferroptosis in primary hepatocytes. The ferroptosis inhibitor ferrostatin-1 (Fer-1) protected against ALF and ferroptosis in vivo. By contrast, HBx exacerbates LPS/D-GalN-induced ALF and ferroptosis in HBx transgenic (HBx-Tg) mice. CONCLUSION: HBx facilitates ferroptosis in ALF via EZH2/H3K27me3-mediated SLC7A11 suppression.

Lignans and Terpenoids from the Leaves of Schisandra chinensis.

Fifteen constituents, including one new lignan (schisandroside E) and one new terpenoid (schisandenoid A) as well as nine known lignans and four known terpenoids, were isolated from Schisandra chinensis leaves. The structures of schisandroside E and schisandenoid A were established by entirely meticulous spectroscopic analysis (NMR, MS, CD, IR and UV). All compounds were tested for cytotoxicity against MGC-803, Caco-2 and Ishikawa cell lines. Some compounds showed strong cytotoxicity against these three cancer cell lines with IC50 <1 µm.

Knockdown of eukaryotic translation initiation factor 3 subunit D (eIF3D) inhibits proliferation of acute myeloid leukemia cells.

Various eukaryotic translation initiation factors (eIFs) have been implicated in carcinoma development. Eukaryotic translation initiation factor 3 subunit D (eIF3D) has recently been shown to regulate the growth of several types of human cancer cells. However, the function of eIF3D in acute myeloid leukemia (AML) remains unclear. In this study, we investigated the expression of eIF3D in three AML cell lines and a lymphoblast cell line, and found that eIF3D was expressed in all four leukemia cell lines. To explore the role of eIF3D in AML cell proliferation, lentivirus-mediated RNA interference was applied to knock down the expression of eIF3D in U937 cells. The expression of eIF3D was significantly downregulated in U937 cells after eIF3D knockdown, as confirmed by quantitative real-time PCR (qRT-PCR) and Western blot analysis. Knockdown of eIF3D significantly inhibited proliferation of U937 cells. Furthermore, flow cytometry analysis revealed that eIF3D silencing induced cell cycle arrest at the G2/M phase, ultimately leading to apoptosis. Our results indicate that eIF3D plays a key role in the proliferation of AML cells, and suggest that eIF3D silencing might be a potential therapeutic strategy for leukemia.

[Functional annotation of rice WRKY transcription factors based on their transcriptional features].

Transcription factors regulate alteration of transcription levels. Recently, huge amount of transcriptomic data are accumulated via the application of high throughput sequencing technology, and it is reasonable to postulate that in-depth analysis of transcription data could be used to enhance gene annotation. In this study, we chose the gene family of rice WRKY transcription factors. Based on literature search, the transcriptional data under different biological processes, including biotic and abiotic stress, development, and nutrient absorption and hormone treatments were analyzed systematically. To the end, we summarize the list of differentially expressed WRKY genes. We also expect that such information will enrich their functional annotation and also provide direct clues for subsequent functional studies.

A down-regulated epi-allele of the genomes uncoupled 4 gene generates a xantha marker trait in rice.

KEY MESSAGE: A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation (xnt), which turns plants yellow and makes them visually distinguishable from normal green rice, has been generated and bred into male sterile lines for hybrid rice production. The xnt locus was previously fine mapped to a ~100-kb interval on chromosome 11, but its identity was unknown. In this study, xnt was further narrowed down to a 57-kb fragment carrying eight opening reading frames (ORFs). All eight ORFs had identical genomic sequences and all but ORF2 (g enomes uncoupled 4, OsGUN4) had similar transcript abundance in the xantha mutant Huangyu B (HYB) and its parental variety Longtefu B (LTB). The expression of OsGUN4, however, was significantly reduced in HYB compared with LTB in terms of both transcript abundance (0.2% that of LTB) and expressed protein level (barely detectable in HYB but greater than the heat shock protein reference in LTB). Therefore, OsGUN4 was identified as the candidate gene underlying the xantha trait. The function of OsGUN4 in the xantha phenotype was confirmed by identification and characterization of new allelic OsGUN4 mutations. Comparative bisulfite genomic sequencing of OsGUN4 revealed increased methylation in a promoter region in the mutant, and the correlation between increased methylation and the xantha phenotype was further verified by demethylation treatment. In summary, we have identified an epi-allele of OsGUN4 as the causal gene of the xantha marker trait and revealed that enhanced methylation in its promoter down-regulated its expression in rice.

Identification of new autoantigens for primary biliary cirrhosis using human proteome microarrays.

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown etiology and is considered to be an autoimmune disease. Autoantibodies are important tools for accurate diagnosis of PBC. Here, we employed serum profiling analysis using a human proteome microarray composed of about 17,000 full-length unique proteins and identified 23 proteins that correlated with PBC. To validate these results, we fabricated a PBC-focused microarray with 21 of these newly identified candidates and nine additional known PBC antigens. By screening the PBC microarrays with additional cohorts of 191 PBC patients and 321 controls (43 autoimmune hepatitis, 55 hepatitis B virus, 31 hepatitis C virus, 48 rheumatoid arthritis, 45 systematic lupus erythematosus, 49 systemic sclerosis, and 50 healthy), six proteins were confirmed as novel PBC autoantigens with high sensitivities and specificities, including hexokinase-1 (isoforms I and II), Kelch-like protein 7, Kelch-like protein 12, zinc finger and BTB domain-containing protein 2, and eukaryotic translation initiation factor 2C, subunit 1. To facilitate clinical diagnosis, we developed ELISA for Kelch-like protein 12 and zinc finger and BTB domain-containing protein 2 and tested large cohorts (297 PBC and 637 control sera) to confirm the sensitivities and specificities observed in the microarray-based assays. In conclusion, our research showed that a strategy using high content protein microarray combined with a smaller but more focused protein microarray can effectively identify and validate novel PBC-specific autoantigens and has the capacity to be translated to clinical diagnosis by means of an ELISA-based method.

Characterization of OsMIK in a rice mutant with reduced phytate content reveals an insertion of a rearranged retrotransposon.

The rice low phytic acid (lpa) mutant Os-lpa-XS110-1(XS-lpa) has ~45 % reduction in seed phytic acid (PA) compared with the wild-type cultivar Xiushui 110. Previously, a single recessive gene mutation was shown to be responsible for the lpa phenotype and was mapped to a region of chromosome 3 near OsMIK (LOC_Os03g52760) and OsIPK1 (LOC_Os03g51610), two genes involved in PA biosynthesis. Here, we report the identification of a large insert in the intron of OsMIK in the XS-lpa mutant. Sequencing of fragments amplified through TAIL-PCRs revealed that the insert was a derivative of the LINE retrotransposon gene LOC_Os03g56910. Further analyses revealed the following characteristics of the insert and its impacts: (1) the inserted sequence of LOC_Os03g56910 was split at its third exon and rejoined inversely, with its 5' and 3' flanking sequences inward and the split third exon segments outward; (2) the LOC_Os03g56910 remained in its original locus in XS-lpa, and the insertion probably resulted from homologous recombination repair of a DNA double strand break; (3) while the OsMIK transcripts of XS-lpa and Xiushui 110 were identical, substantial reductions of the transcript abundance (~87 %) and the protein level (~60 %) were observed in XS-lpa, probably due to increased methylation in its promoter region. The above findings are discussed in the context of plant mutagenesis, epigenetics and lpa breeding.

[Effect of hepatitis B virus X protein on suppressor of cytokine signaling-1 expression].

OBJECTIVE: To investigate the effect of hepatitis B virus-encoded X protein (HBx) on the expression of host-encoded suppressor of cytokine signaling-1 (SOCS-1) and to explore the possibility of an underlying mechanism involving modulation of CpG island methylation in the SOCS-1 gene promoter. METHODS: The immortalized human derived non-tumor liver cell line QSG7701 was transfected with a recombinant HBx plasmid (pcDNA-X) or an empty vector control plasmid (pcDNA3.0) and stably transfected clones were selected by G418 resistance screening. Untransfected cells served as negative controls. Expression of SOCS-1 mRNA and protein was detected by real-time quantitative PCR and western blotting. The methylation status of SOCS-1 was detected by methylation-specific PCR (MSP). The significance of intergroup differences was analyzed by one-way ANOVA or pairwise comparison with post-hoc LSD test. RESULTS: SOCS-1 mRNA level was significantly lower in the pcDNA-X/QSG7701 cells compared to that in the pcDNA3.0/QSG7701 and untransfected cells (0.3249+/-0.0536 vs. 1.0543+/-0.1937 and 1.00; F = 19.6, P = 0.042). SOCS-1 protein level was similarly lower in the pcDNA-X/QSG7701 cells (0.1496+/-0.0106 vs. 0.1984+/-0.0438 and 0.2152+/-0.0816; F = 19.4, P = 0.048). The SOCS-1 promoter region showed methylation only in the pcDNA-X/QSG7701 cells. CONCLUSION: HBx-expressing human hepatocytes have down-regulated SOCS-1 expression, both at the mRNA and protein levels, and this effect corresponds to increased methylation in the SOCS-1 promoter region harboring CpG islands.

[Effect of microRNA on proliferation caused by mutant HBx in human hepatocytes].

To study the effect of micro (mi)RNA on cellular proliferation induced by hepatitis B x protein, HBx, in human liver cells and to investigate the underlying molecular mechanism of this cancer-related effect. The human L02 hepatocyte cell line was stably transfected with HBx (L02/HBx) or an HBx mutant (L02/HBx-d382) that induces higher levels of cellular proliferation. The differential miRNA expression profiles were determined by microarray analysis and confirmed by real-time PCR. Two miRNAs, miR-338-3p and miR-551b, that were found to be significantly down-regulated in the L02/HBx-d382 cells were selected for further study and transfected individually into cells using the lipofectamine procedure. The cell survival rate was analyzed by MTT assay, and cell cycles were assessed by flow cytometry. Expressions of cyclinD1, cyclinG1, and E2F1 were assessed by real-time PCR and Western blotting. Compared with the microarray miRNA profile of L02/pcDNA3.0 cells, six miRNAs were up-regulated and five miRNAs were down-regulated in the L02/HBx-d382 cells, while four miRNAs were up-regulated and 12 were down-regulated in the L02/HBx cells. The microarray results were consistent with real-time PCR results. Transfection of miR-338-3p and miR-551b significantly inhibited the cell survival rates (P less than 0.001) and induced G0/G1 phase cycle arrest. According to MTT results: for L02/HBx-d382 cells, compared with lipofectamine or non-transfected (NC) controls, the t value of miR-338-3p was 10.402, 9.133 and the t value of miR-551b was 8.763, 7.403; for L02/HBx cells, compared with lipofectamine or NC controls, the t value of miR-338-3p was 9.105, 8.074 and the t value of miR-551b was 7.673, 7.52. According to flow cytometry results: for L02/HBx-d382 cells, compared with lipofectamine or NC controls, the t value of miR-338-3p was 12.173, 11.107 and the t value of miR-551b was 15.364, 13.377; for L02/HBx cells, compared with lipofectamine or NC controls, the t value of miR-338-3p was 15.416, 13.378, and the t value of miR-551b was 13.276, 13.109. The protein levels of cyclinD1, cyclinG1, and E2F1 were significantly reduced by both miR-338-3p and miR-551b ( P less than 0.001). For L02/HBx-d382 cells, compared with lipofectamine or NC controls: E2F1 had t = 11.132, 10.031 and 12.017, 10.973, respectively; cyclinD1 had t = 15.654, 15.013 and 15.447, 14.733, respectively; cyclinG1 had t = 8.017, 7.661 and 7.402, 7.417, respectively. For L02/HBx cells, compared with lipofectamine or NC controls: E2F1 had t = 14.244, 13.331 and 15.022, 14.468, respectively; cyclinD1 had t = 8.695, 8.137 and 7.877, 7.503, respectively; cyclinG1 had t = 7.73, 7.471 and 7.596, 7.41, respectively. In contrast, the mRNA levels for E2F1, cyclinD1, and cylcinG1 showed no significant differences between the miRNA transfected cells and controls. Wild-type HBx and the high proliferation-inducing mutant HBx can influence the miRNA expression profile of L02 cells. HBx down-regulates miR-338-3p and miR-551b in L02 cells, and the high proliferation-inducing mutant has a more robust effect. The mechanism of miR-338-3p- or miR-551b-mediated cell growth inhibition appears to be related to the direct modulation of cyclinD1, cyclinG1, and E2F1.

Prevalence and incidence of pseudomyxoma peritonei in urban China: A nationwide retrospective cohort study.

BACKGROUND: Pseudomyxoma peritonei (PMP) is an extremely rare condition. Information regarding the disease burden of PMP in developing countries is limited. This study aimed to determine the epidemiology of PMP in China. METHODS: PMP data were extracted from the national databases of Urban Basic Medical Insurance. All cases were identified using the International Classification of Diseases (ICD) codes and Chinese diagnostic terms. The national prevalence from 2012 to 2016 and incidence in 2016 were estimated. RESULTS: In total, 153 patients with PMP were identified. The crude prevalence of PMP in 2016 was 2.47 (95% confidence interval [CI] 1.71 to 3.23) per million person-year, with a higher prevalence in females than males. Prevalence increased with age, with the first peak in those aged 15-29 years and the highest in those aged >80 years. The crude incidence of PMP in 2016 was 1.19 (95% CI 0.59 to 1.78) per million person-years. Similar to the prevalence, the rates were higher in women than in men. The incidence also increased with age, with the highest prevalence in those aged >80 years. Besides, the most frequent comorbidities before and after the first diagnosis of PMP were unspecified secondary malignancies and malignancies of unspecified sites, followed by abdominal malignant tumours. CONCLUSIONS: The rate of PMP was lower in mainland China than in European countries and increased with advancing age. Women were more likely to have PMP than men. Furthermore, an insufficient understanding of this rare disease presents a major challenge in accurately evaluating the disease burden.

Association of Ethnicity, Sex, and Age With Cancer Diagnoses and Health Care Utilization Among Children in Inner Mongolia, China.

Importance: China is experiencing a sustained increase in childhood cancer. However, whether differences exist in disease burden by ethnicity remains unclear. Objective: To compare differences in cancer diagnoses and health care utilization in Inner Mongolia among children subgrouped by ethnicity (Han vs Mongolian), sex, and age. Design, Setting, and Participants: This retrospective cohort study in Inner Mongolia, China, used data on children aged 0 to 14 years with cancer from the Inner Mongolia Regional Health Information Platform, which comprises the National Basic Medical Insurance database and the Inner Mongolia cause-of-death reporting system, from January 1, 2013, to December 31, 2019. Ethnicities analyzed included Han and Mongolian; patients of other ethnicities were not included in the analysis because of the small sample size. Cancer was broadly defined as a primary malignant tumor or hematologic cancer; benign central nervous system tumors were also included. A 2-year washout period was used to exclude prevalent cases. After diagnosis, the patients were followed up until the date of death or the end of the insured status, whichever came first. Exposures: Ethnicity (Han vs Mongolian), sex (male vs female), and age (0-4, 5-9, and 10-14 years). Main Outcomes and Measures: Crude incidence, 5-year prevalence, and survival rates at 1 year and 3 years after diagnosis; health care utilization, represented by medical costs during the first year and first 3 years after diagnosis; and hospital attendance with level (tertiary vs secondary and lower-level hospitals) and location of each unique visit. Results: From 2013 to 2019, 1 106 684 (2013), 1 330 242 (2014), 1 763 746 (2015), 2 400 343 (2016), 2 245 963 (2017), 2 901 088 (2018), and 2 996 580 (2019) children aged 0 to 14 years were registered in the NBMI database. Among the 2 996 580 children enrolled in 2019, the mean (SD) age was 6.8 (4.3) years, of whom 1 572 096 (52.5%) were male, 2 572 091 (85.8%) were Han, and 369 400 (12.3%) were Mongolian. A total of 1910 patients with cancer were identified (1048 were male [54.9%]; 1559 were Han [81.6%], and 300 were Mongolian [15.7%]). There were 764 hematologic cancers (40.0%) and 1146 solid tumors (60.0%). The overall crude incidence of cancer from 2015 to 2019 was 129.85 per million children (95% CI, 123.63-136.06), with a higher incidence among Mongolian than among Han children (155.12 [95% CI, 136.81-173.43] vs 134.39 [95% CI, 127.46-141.32]). The 5-year prevalence was 428.97 per million (95% CI, 405.52-452.42) in 2020, with a higher prevalence among Mongolian than among Han children (568.49 [95% CI, 91.62-645.36] vs 404.34 [95% CI, 379.77-428.91]). The combined 1-year (2015-2019) and 3-year (2015-2017) survival rates were 72.5% (95% CI, 67.5%-77.5%) and 66.8% (95% CI, 61.6%-71.9%), respectively. The 1-year (median [IQR], $1991 [$912-$10 181] vs $3991 [$1171-$15 425]) and 3-year (median [IQR], $2704 [$954-$13 909] vs $5375 [$1283-$22 466]) postdiagnosis costs were lower among Mongolian than among Han children. A higher proportion of Mongolian patients attended low-level hospitals (45.9% vs 17.4%). Conclusions and Relevance: In this cohort study, Mongolian children had a higher incidence and prevalence of cancer but a lower demand for medical care, suggesting that further investigations are needed to identify mechanisms underlying ethnic disparities and ensure that care is equitable.

Daturmetesides A-E, five new ergostane-type C28 sterols from the leaves of Datura metel L.

Five undescribed ergostane-type C28 sterols, daturmetesides A-E (1-5), were isolated from the leaves of Datura metel L. The chemical structures of these new compounds were characterized through extensive spectroscopic analysis and comparison with literatures. Among them, the absolute structures of daturmetesides A and C were unambiguously determined by X-ray crystallography. The anti-inflammatory effect of daturmetesides A-E was all tested by measuring nitric oxide production in lipopolysaccharide-activated RAW264.7 cells. Daturmetesides A, C and D moderatelylowered the NO production with IC50 values ranging from 17.05 ± 0.35 to 24.88 ± 0.93 µM.

[Study on tumor formation of hepatocyte transformed by hepatitis B virus X gene in nude mice.].

OBJECTIVES: To investigate whether hepatitis B virus X gene alone is sufficient to transform the non-transformed immortalized human liver cell line QSG7701 and induce hepatocellular carcinoma in vivo. METHODS: pCMVX/QSG7701 cells were transplanted into subcutaneous tissue of nude mice. pRcCMV2/QSG7701 and QSG7701 cells were used as control. Tumor formation was checked within 5 weeks after transplantation. The activity and food intake of the nude mice were recorded. The texture, volume and metastasis of transplantation tumor were observed grossly, and the HE stained transplantation tumor tissues were observed under optical microscope. RESULTS: The transplantation tumor occurred in all of the six nude mice inoculated with pCMVX/QSG7701 cells at the second week after inoculation. No metastatic tumor was found in other organs. Transplant tumor was not formed in all of the negative control groups. The activity, eating and drinking of the nude mice transplanted with pCMVX/QSG7701 cells were normal, while their weights were increased gradually in the first 3 weeks. Since the 4th week after transplantation with pCMVX/QSG7701 cells, the activity of the mice was decreased and their body weight was no longer increased. It is interesting that the mental state and eating of those nude mice inoculated with pRcCMV2/QSG7701and QSG7701 cells were normal, and the weight was increasing all the time after inoculation. HE staining analysis confirmed that the transplanted tumor was hepatocellular carcinoma. CONCLUSION: HBx alone is sufficient to transform the non-transformed immortalized human liver cell line QSG7701 and induce hepatocellular carcinoma in vivo.

Knockdown of immature colon carcinoma transcript 1 induces suppression of proliferation, S-phase arrest and apoptosis in leukemia cells.

Immature colon carcinoma transcript 1 (ICT1), a human mitochondrial translation release factor, is a ribosome-dependent codon-independent peptidyl-tRNA hydrolase. ICT1-deficiency has been recognized as a cell growth inhibitor of hepatoblastoma and glioblastoma multiforme. To explore the role of ICT1 in human leukemia, 2 short hairpin RNAs (shRNAs) targeting ICT1 sequences were designed in leukemia U937 cells. The successful infection of ICT1 in the U937 cells was observed under a fluorescence microscope and further quantified by western blotting and quantitative real-time PCR (qRT-PCR) analysis. Tetrazolium dye (MTT) assay revealed a significant decrease in proliferation of ICT1-knockdown U937 cells on the fourth and fifth day as compared with the control. Depletion of ICT1 resulted in an increase in S phase and sub-G1 (representing cell apoptosis) fractions. Annexin V-APC/7-AAD staining assay confirmed that knockdown of ICT1 played a crucial role in boosting early and late apoptotic programs in U937 cells. Downregulation of ICT1 also altered cyclin A2 transcription expression, caspase-3 activity and p21 protein expression. Additionally, decreased levels of heat shock protein 27 (HSP27) phosphorylation at Ser78 was correlated with knockdown of ICT1 in U937 cells. Thus, we concluded that the regulatory role of ICT1 in leukemia may be used as a potential therapeutic target for the treatment of leukemia.

[Expression and autophosphorylation analysis of XA21 and PI-D2 protein kinases in Saccharomyces cerevisiae].

Rice bacterial blight and blast are the most crucial rice disease. Xa21 confers resistance to bacterial blight, while Pi-d2 confers resistance to rice blast. Both Xa21 and Pi-d2 encode receptor kinase-like proteins. Biochemical properties of XA21 kinase expressed in bacterial were characterized in our previous report. In this study, both XA21 and PI-D2 kinase domain were PCR amplified and cloned into yeast expression vector pEGH via recombinational cloning strategy, kinase proteins expressed in eukaryotic yeast system was purified and autophosphorylation assay was carried out. The results indicated that XA21 and PI-D2 protein can be detected by SDS-PAGE and showed expected molecular weight. Autophosphorylation assay indicated that yeast expressed XA21 and PI-D2 were active when incubated with P32 labelled ATP. The experiment provided basic materials for biochemical prosperity analysis, protein-protein interaction and substrate screening research.

[Advances of rice bacterial blight disease resistance gene Xa21].

Gene Xa21 is the first disease resistance gene cloned from rice (Oryza sativa L.), which encodes a receptor-like kinase and confers broad spectrum resistance against Xanthomonas oryzae pv. oryzae (Xoo). In this paper, the discovery, mapping and cloning of Xa21 were reviewed briefly. The molecular mechanism of resistance and its breeding application, including biochemical properties of the kinase domain of XA21, AvrXa21 identification, the disease resistance pathway mediated by Xa21, and the mechanism of disease resistance were summarized. Future perspective on Xa21-related research is also discussed.