The application of single-genome amplification and sequencing in genomic analysis of an attenuated EIAV vaccine / 病毒学报

Our previous studies found that the Chinese attenuated EIAV vaccine was composed of a pool of quasispecies, which showed a complicated diversity called "multi-species". Further determining the viral composition of these species in the vaccine should improve the identification of predominant viruses in the vaccine and facilitate the analysis of in vivo evolution of EIAV and the vaccine. In this study, the comparison of fidelities in amplifying and sequencing the V3 to V5 fragment of EIAV envelope gp90 gene by either a single-genome amplification (SGA) approach or the traditional RT-PCR (bulk PCR) was performed. Results revealed that the diversities were 1.84% and 1.88% for SGA- and bulk PCR-derived sequences, respectively. Futher analysis revealed that beside the sequences highly homologous to those derived by the bulk PCR, nine of 73 sequences derived by SGA contained a deduced amino acid domain that was identical to the corresponding domain in the virulent strain LN40. In addition, sequences with deletion of one predicted amino acid residual was detected by using SGA The presence of these less populated sequences provided additional evidence for the "multi-species" hypothesis for the action mechanism of the EIAV vaccine. Furthermore, based on the analysis of sampling bias, Our results that the difference in copy number of each viral specie in the pool of quasispecies resulted in the inefficiency to amplify viral sequences that were in low population by bulk PCR. Therefore, the sequences amplified by bulk PCR could not correctly represent the composition of quasispecies. As an approach based on the amplification and sequencing single isolated genome, SGA significantly improved the weakness of bulk PCR and appeared its advantage in analysis of EIAV genome composition with high variety.

Expression of survivin and proliferating cell nuclear antigen in human non-small cell lung cancer / 中南大学学报(医学版)

OBJECTIVE@#To determine the expressions of survivin and proliferating cell nuclear antigen (PCNA)in non-small cell lung cancer (NSCLC) and to explore its clinical pathological significance.@*METHODS@#Immunohistochemical SP method was used to detect the expressions of survivin and PCNA in 43 patients with NSCLC and 15 normal epithelial tissues of the lung. PCNA labeling proliferative index was assessed. Forty-three patients with NSCLC were followed up for more than 5 years.@*RESULTS@#The positive expression of survivin in NSCLC (79.1%) was significantly higher than that in normal epithelial tissues of the lung (P 0.05). The mean proliferative index of PCNA in NSCLC was much higher than that in normal epithelial tissues of the lung (P < 0.01). A positive correlation was present between the proliferative index and the tumor size, lymph node metastase, and clinical stage (P <0.01), while a negative correlation between the proliferative index and survival time (P <0.01). There was no correlation between proliferative index and age, sex, site, histological type and grade. The proliferative index was larger in patients with moderate or strong positive survivin expression than that in patients with negative or weak survivin expression (P < 0.05).@*CONCLUSION@#Over expression of survivin and PCNA is closely correlated to the progression and prognosis of patients with NSCLC, which is helpful to evaluate the progression of cancer and to predict the prognosis of NSCLC. The up-regulation of survivin expression and its close relationship with the cell proliferation in NSCLC suggest that survivin may play an important role in the carcinogenesis and development of lung cancer.