ABSTRACT
The Xuanwei county in China has a high incidence of lung cancer and related mortality. Previous studies have suggested that these cases may be associated with a distinctive pattern of mutations in the epithelial growth factor receptor (EGFR) gene. In this retrospective study, we investigated the mutation profile of EGFR in non-small-cell lung cancer (NSCLC) tissues from patients in Xuanwei, and the associated clinicopathological characteristics. Specimens from 258 consecutive patients with lung cancer (90 from Xuanwei and 168 from other areas of Yunnan province) were subjected to amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) to detect EGFR mutations. In 67 specimens from Xuanwei, the results were confirmed by direct DNA sequencing for EGFR mutations. Immunohistochemistry (IHC) for the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion protein was performed on all specimens from Xuanwei. We observed that Xuanwei patients presented with distinctive clinicopathological characteristics, including female gender predominance, younger age, higher rate of lymph node metastasis, higher rate of adenocarcinoma histological classification and lower disease stage, and a low rate of the 'classical' mutations on EGFR exons 19 and 21 compared with non-Xuanwei patients (7.8 and 21.6% vs. 49.3 and 39.7%, respectively; P<0.05 for combined data). However, a significantly higher percentage of Xuanwei patients harbored co-mutation of EGFR exons 18 and 20 compared with non-Xuanwei patients (45.1 vs. 4.1%, respectively; P<0.0001). Specimens from 2 Xuanwei patients (2.2%) were positive for the EML4-ALK fusion protein; by IHC, neither harbored EGFR mutations. There was no obvious association between EGFR mutations and disease stage or lymph node involvement. Thus, NSCLC patients in Xuanwei presented with a unique EGFR profile of high rates of co-mutation of exons 18 and 20, and low rates of exon 19 or 21 mutations when compared with patients from other areas in the same province, whereas only few of the tumors from Xuanwei patients expressed the EML4-ALK oncogene.
ABSTRACT
We examined the effect of respiratory syncytial virus (RSV) infection on viperin protein expression in the permissive HEp2 and non-permissive RAW 264.7 macrophage cell lines. In RSV-infected HEp2 cells low levels of the viperin protein was localized to the virus-induced inclusion bodies and did not impair virus transmission in these cells. In contrast, RSV-infected RAW 264.7 cells increased expression of the STAT1 protein occurred at between 6 and 12h post-infection, which coincided with the appearance of P-STAT1. A relatively high level of viperin protein expression was detected in infected RAW 264.7 cells, and it was extensively localized throughout the cytoplasm of infected cells. The effect of early viperin protein expression on RSV infection in cells that are normally permissive to RSV cultivation was examined by using either transient transfected HEp2 cells or stable transfected HeLa cells that expressed the viperin protein. The early expression of viperin in HeLa cells did not prevent virus infection, and no significant inhibitory effect on either virus protein expression or targeting of virus proteins to the cell surface was noted. However, while inclusion body formation was not inhibited, early viperin protein expression was associated with the inhibition of virus filament formation and reduced cell-to-cell virus transmission. Inhibition of virus filament formation was also observed in HEp2 cells expressing viperin. Collectively our data suggested that viperin impaired RSV transmission by inhibiting virus filament formation, providing a basis for its anti-virus activity in RSV-infected cells.
