[Mechanism of lncRNA-SRLR induced invasion and metastasis in U2OS osteosarcoma cells]

Objective: To explore the potential mechanism of sorafenib resistance associated long non-coding RNA (lncRNA-SRLR) promoted invasion and metastasis in U2OS osteosarcoma cells. Methods: We transfected U2OS cells with negative control lentivirus (LV-NC) or lncRNA-SRLR overexpressed lentivirus (LV-over/SRLR) particles. LV-NC and LV-over/SRLR stable transfected cells (U20S/NC and U20S/SRLR) were selected by primary cell culture medium containing puromycin. The mRNA expressions of lncRNA-SRLR and procollagen-lysine, procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The effect of lncRNA-SRLR on the invasion of U2OS cells were determined by wound-healing assay and Transwell migration assay. The effect of SRLR on the interleukin-6 (IL-6) secretion of U2OS cells was evaluated by enzyme-linked immunosorbent assay (ELISA) analysis. The subcellular distribution of SRLR in U2OS cells was detected by fluorescence in situ hybridization (FISH) analysis.The expression of PLOD2 in cells was detected by immunofluorescence (IF). The expressions of PLOD2 and focal adhesion kinase (FAK)/signal transducer and activator of transcription 3 (STAT3) signal pathway related proteins in U2OS/NC and U2OS/SRLR cells were detected by western blotting. Results: qRT-PCR assay showed that mRNA expressions of lncRNA-SRLR and PLOD2 in U2OS/SRLR cells were (3 964.97±0.05) and (2.77±0.11), respectively, significantly higher than those in U2OS/NC cells (P<0.001 or P<0.01). The results of wound-healing and Transwell migration assay showed that over-expression of SRLR markedly promoted the invasion ability of U2OS cells (P<0.05). The result of ELISA analysis showed that the IL-6 secretions in U2OS/NC or U2OS/SRLR cells were (125.38±11.22) pg/ml or (119.97±13.43) pg/ml, without statistical significance (P>0.05). The subcellular distribution assay revealed that lncRNA-SRLR is predominately located in the nucleus. The result of IF showed that compared with U2OS/NC cells, the expression of PLOD2 was up-regulated in U2OS/SRLR cells. The result of western blotting showed that over-expression of SRLR significantly increased the expression levels of PLOD2, phosphorylation (p)-FAK and p-STAT3 in U2OS cells (P<0.01). Conclusion: lncRNA-SRLR promotes invasion and metastasis of osteosarcoma by activating PLOD2-FAK/STAT3 signal axis.

[Mechanism of PLOD2 induced osimertinib resistance in non-small cell lung cancer HCC827 cells]

Objective: To investigate the effects of osimertinib on proliferation, migration and invasion of procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2) overexpressing HCC827 cells and explore the potential mechanism of PLOD2 induced osimertinib resistance. Methods: We transfected HCC827 cells with LV-vector and LV-over/PLOD2. The expression of PLOD2 was detected by quantitative real time polymerase chain reaction (qRT-PCR) and western blotting. The effects of osimertinib on the proliferation of HCC827-vector and HCC827-PLOD2 cells were evaluated by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay. The effects of osimertinib on the migration and invasion of HCC827-vector and HCC827-PLOD2 cells were determined by Transwell assays. The expressions of E-cadherin and vimentin in cells were detected by immunofluorescence (IF). The expressions of epithelial-mesenchymal transition (EMT), FAK-PI3K/AKT and MAPK signal pathway related proteins were detected by western blotting. Results: The MTT assay showed that HCC827-PLOD2 cells were hyposensitive to osimertinib. The 50% inhibitory concentration (IC(50)) and resistance index of osimertinib for HCC827-PLOD2 cells was over 1 000 nmol/L and over 100, respectively. The result of wound healing assay showed that the migration distance of HCC827-PLOD2 was about (2.13±0.21) fold changes as that of HCC827-vector cells. The result of Transwell assay showed that the numbers of HCC827-PLOD2 passing through the matrix membrane were (212.78±10.43), significantly higher than (101.32±12.52) of HCC827-vector cells (P<0.01). The result of IF showed that compared with HCC827-vector cells, the expression of E-cadherin was down-regulated while vimentin was up-regulated in HCC827-PLOD2 cells. Osimertinb downregulated E-cadherin and upregulated vimentin expression in HCC827-vector cells but had limited effect in HCC827-PLOD2 cells. The result of western blotting showed that PLOD2 significantly increased vimentin expression level while decreased E-cadherin expression level. Osimertinib inhibited the expression of p-EGFR, but did not affect the expressions of PLOD2, p-FAK, p-AKT, p-ERK, vimentin and E-cadherin in HCC827-PLOD2 cells. Conclusion: PLOD2 confers resistance to osimertinib in HCC827 cells by regulating EMT, FAK-PI3K/AKT and MAPK signal pathways.

[The clinical characteristics and prognosis of 20 patients with H7N9 avian influenza]

Objective: To analyzed the clinical characteristics and prognosis of patients with H7N9 avian influenza. Methods: The baseline characteristics, clinical manifestations, treatments, laboratory and imaging findings were collected and analyzed for 20 patients with H7N9 avian influenza admitted to the First Affiliated Hospital of Nanchang University from December 2016 to March 2017. According to the final clinical outcome, the patients were divided into the death group and the survival group. Ten patients in the death group died, and 10 patients in the survival group were discharged. The data with normal distribution were analyzed by t test. The data with non-normal distribution were analyzed by Wilcoxon rank sum test. Results: Of the 20 patients, 13 were males and 7 were females, aging 40-82 years, with a mean age of (60±12) years. Twelve patients had a definite history of poultry exposure and 10 had chronic underlying diseases such as hypertension and diabetes. The clinical manifestations were mainly fever, cough, hemoptysis, respiratory distress, fatigue, etc. In the survival group, the platelet count was(167-315)×10(9)/L, while it was (78-152)×10(9)/L in the death group. The average white blood cell count was (7.78-11.52)×10(9)/L and (9.91-15.93)×10(9)/L in the survival and death groups respectively. The average value of lymphocyte count was (0.69-1.59)×10(9)/L and (0.58-0.86)×10(9)/L in the survival and death groups respectively. In the death group the glutamic-pyruvic transaminase (ALT) value was (14.0-352.0) U/L, the total bilirubin value was (6.9-34.5) μmol/L, the creatine kinase MB (CK-MB) was (16.0-162.0) U/L, the serum calcium value was (1.4-2.0) mmol/L, the C-reactive protein value was (33.1-414.0) mg/L, and the calcium reduction prime value was (0.6-100.0) μg/L. In the survival group,the ALT value was (25.0-181.0) U/L, the total bilirubin value was (4.8-25.9) μmol/L, the CK-MB value was (15.0-40.0) U/L, the serum calcium value was (1.9-2.4) mmol/L, the C-reaction protein value was (12.8-52.5) mg/L, and the procalcitonin value was (0.3-23.3) μg/L. Sixteen cases suffered severe pneumonia. Twelve patients received extracorporeal membrane oxygenation (ECMO), and 4 survived. The cause of death was mainly related to factors such as age, chronic underlying diseases and severity of illness. Conclusions: Human infection with H7N9 avian influenza virus was highly pathogenic, and prone to progress into severe pneumonia, with a high mortality. Decreased platelet count was associated with mortality (t=4.07, P=0.001), predictive of patient outcome.

[Expression of PLOD2 in esophageal squamous cell carcinoma and its correlation with invasion and metastasis]

Objective: To investigate PLOD2 expression in esophageal squamous cell carcinoma, and to explore the potential mechanism by which PLOD2 promotes tumor metastasis. Methods: The expression of PLOD2 in 60 cases of esophageal squamous cell carcinoma (the patients were collected at the first Affiliated Hospital of Xinxiang Medical University, from January 2016 to December 2017) was investigated by immunohistochemistry. Fibrillar collagen formation and collagen deposition were detected by picrosirius red staining. Correlation of PLOD2 expression with clinical pathologic features of the patients was performed using χ(2) test and Kaplan-Meier analysis. After EC-109 cells were transfected with LV-vector and LV-over/PLOD2, the expression of PLOD2 was detected by real time PCR and the impact of POLD2 on invasion in EC-109 cells was determined by transwell migration and invasion assays. The expression of PLOD2/AKT epithelial-to-mesenchymal transition signal pathway related proteins was detected by Western blot. Results: The expression level of PLOD2 in esophageal squamous cell carcinoma was 81.7% (49/60 cases),higher than their paired noncancerous tissues(8.3%, 5/60; P<0.01), and correlated significantly with tumor depth of invasion and nodal metastasis (P<0.01). Picrosirius red staining showed that collagen deposition was increased and the degree of fibrillar organization was enhanced in carcinoma tissues that had higher PLOD2 expression. Transwell migration and invasion assays showed that PLOD2 significantly promoted the migration and invasion ability of EC-109 cells. Western blot showed that PLOD2 significantly increased the expression levels of p-FAK, p-AKT and vimentin in EC-109 cells. Conclusions: Esophageal squamous cell carcinoma has a high expression of PLOD2 that correlates with tumor invasion and lymph node metastasis. PLOD2 promotes invasion and metastasis of esophageal squamous cell carcinoma through epithelial-to-mesenchymal transition via FAK/AKT signal pathway.

[Mechanism of long non-coding RNA-metastasis associated lung adenocarcinoma transcript 1 induced invasion and metastasis of esophageal cancer cell EC-109]

Objective: To investigate the effect and mechanism of long non-coding RNA-metastasis associated lung adenocarcinoma transcript 1, (LncRNA-MALAT1) on invasion and metastasis of esophageal cancer cell EC-109. Methods: EC-109 cells were transfected with lentiviral vector carrying short hairpin RNA of MALAT1( shRNA-MALAT1) or a nonspecific shRNA control (shRNA-control). The expressions of MALAT1, microRNA-200a, ZEB1 and ZEB2 were detected by qRT-PCR. The effect of shRNA-MALAT1 on invasion of EC-109 cells was determined by transwell assay. The expressions of components of epithelial-msenchymal transition pathway in EC-109 cells were determined by immunofluorescence array and western blotting. The expression relationship between MALAT1 and miR-200a in EC-109 cells was detected by dual-luciferase reporter assay. Results: The result of qRT-PCR showed that the expressions levels of MALAT1, ZEB1 and ZEB2 in shRNA-MALAT1 group were 0.43±0.06, 0.64±0.04 and 0.51±0.04, respectively, significantly lower than 0.97±0.08, 1.06±0.07 and 0.98±0.05 in shRNA-control group and 1 in control group, respectively(all P<0.05). Transwell assay showed that the number of invaded cells in shRNA MALAT1 group was (96.81±10.43) per low-power field, markedly lower than that of (278.44±13.28) per low-power field in shRNA-control group (P<0.01). Immunofluorescence staining and Western blotting showed that MALAT1 downregulation significantly reduced the expressions of proteins related to EMT signal pathway in EC-109 cells.Dual luciferase reporter assay showed that compared to negative control, the activities of luciferase reporter in EC-109 cells co-transfected with pmirGLO-MALAT1-wt and miR-200a were significantly down-regulated. While co-transfected pmirGLO-MALAT1-mut with miR-200a mimics had no effect on the luciferase reporter activities of MALAT1. Conclusion: LncRNA MALAT1 functions as a competing endogenous RNA to regulate the expressions of ZEB1 and ZEB2 by sponging miR-200a and promotes invasion and migration of esophageal cancer cells through inducing epithelial-mesenchymal transition.

Development of SCAR Markers and an SYBR Green Assay to Detect Puccinia striiformis f. sp. tritici in Infected Wheat Leaves

Stripe rust, caused by the pathogenic fungus Puccinia striiformis f. sp. tritici, is an important disease of wheat worldwide. A rapid and reliable detection of the pathogen in latent infected wheat leaves is useful for accurate and early forecast of outbreaks and timely application of fungicides for managing the disease. Using the previously reported primer pair Bt2a/Bt2b, a 362-bp amplicon was obtained from P. striiformis f. sp. tritici and a 486-bp amplicon was obtained from both P. triticina (the leaf rust pathogen) and P. graminis f. sp. tritici (the stem rust pathogen). Based on the sequence of the 362-bp fragment, two pairs of sequence characterized amplified region (SCAR) primers were designed. PSTF117/PSTR363 produced a 274-bp amplicon and TF114/TR323 produced a 180-bp amplicon from P. striiformis f. sp. tritici, whereas they did not produce any amplicon from P. triticina, P. graminis f. sp. tritici, or any other wheat-infecting fungi. The detection limit of PSTF117/PSTR363 was 1 pg/µl and TF114/TR323 was 100 fg/µl. Both SCAR markers could be detected in wheat leaves 9 h post inoculation. An SYBR Green RT-PCR method was also developed to detect P. striiformis f. sp. tritici in infected leaves with the detection limit of 1.0 fg DNA from asymptomatic leaf samples of 6 h after inoculation. These methods should be useful for rapid diagnosis and accurate detection of P. striiformis f. sp. tritici in infected wheat leaves for timely control of the disease.

Isolation and characterization of the anthocyanidin genes PAL, F3H and DFR of Scutellaria viscidula (Lamiaceae)

Anthocyanidin is a group of flavonoid compounds used as a vegetable pigment and plays an important role in flower coloration and environmental adaptations of the Chinese ornamental plant Scutellaria viscidula. We determined the cDNA sequences of phenylalanine ammonia-lyase (SvPAL), flavanone 3-hydroxylase (SvF3H) and dihydroflavonol 4-reductase (SvDFR) genes in S. viscidula. Comparative analysis showed that the protein products of these three genes did not have a transit peptide at their N-terminal portion, which indicated that these enzymes were directly involved in the substrate conversion in the cytoplasmic matrix. Bioinformatic analysis further revealed that Svpal, Svf3h and Svdfr were the members of flavonoid biosynthetic genes with highly conserved motifs. Based on phylogenetic tree analysis, it appears that PAL, F3H or DFR from different plants might have originated from the same ancestor. This study can help to map and regulate the important stages involved in anthocyanidin biosynthesis by genetic engineering to diversify flower color and improve the ornamental value of S. viscidula.