ABSTRACT
Extranodal nasal-type natural killer cell lymphoma (ENKL) is a high-grade malignancy and is associated with Epstein-Barr virus (EBV) latent infection. Little is known about its molecular abnormalities. Here, we studied the expression of Skp2 and p27 proteins in 48 cases of ENKL, and we evaluated their correlations with EBV status and clinical outcomes. EBV infection was observed in 90% of the cases. In all, 71% of the ENKLs were positive to Skp2 and 73% were negative to p27. A significant negative correlation was observed between the expression of Skp2 and p27 proteins (P = 0.022). Fifty-eight percent of the cases were Skp2+/p27- phenotype and correlated with EBV status (P = 0.047). The overall survival was influenced by the expression of Skp2, p27, and Skp2/p27. Patients with Skp2+, p27-, and Skp2+/p27- phenotypes had worse overall survival (P < 0.01, P = 0.016, and P < 0.01, respectively). Multivariance analysis showed the Skp2/p27 expression profile was an independent prognostic factor for overall survival (RR = 3.09, P < 0.01, 95% CI: 1.27-7.51). In conclusion, the Skp2/p27 expression profile is a helpful prognostic factor for ENKL. Latent EBV infection may increase the expression levels of Skp2, and consequently, p27 protein degradation is accelerated. EBV may be a good target for treatment of EBV-associated ENKL.
Subject(s)
Cyclin-Dependent Kinase Inhibitor p27/metabolism , Herpesvirus 4, Human/physiology , Lymphoma, Extranodal NK-T-Cell/metabolism , Lymphoma, Extranodal NK-T-Cell/virology , S-Phase Kinase-Associated Proteins/metabolism , Female , Gene Expression Profiling , Humans , Immunohistochemistry , Lymphoma, Extranodal NK-T-Cell/pathology , Male , Phenotype , Survival AnalysisABSTRACT
<p><b>OBJECTIVE</b>To establish human bronchial epithelial cell lines over expressing oncogene and to investigate its application in detection of carcinogen-induced cell transformation.</p><p><b>METHODS</b>Mediated by retrovirus infection, human telomerase catalytic subunit, hTERT was introduced into immortal human bronchial epithelial cells (16HBE) and followed by introduction of the oncogenic allele H-Ras(V12), or c-Myc or empty vector, creating cell lines 16HBETR, 16HBETM and 16HBETV, respectively. Biological characteristics of these cell lines including morphology, proliferation, and chromosomal aberration were examined to access whether they were transformed. Soft agar experiment and nude mice subcutaneous injection were performed using pre-transformed 16HBE cells induced by known carcinogens, nickel sulfate (NiSO4) and 7, 8, -dihydrodiol-9, 10-epoxide benzo[a] pyrene (BPDE).</p><p><b>RESULTS</b>With detection of telomerase activity and Western blotting, the expression of target proteins was verified. Thus, the transgenic 16HBE cell lines were successfully established. Cells expressing oncogene H-Ras or c-Myc grew 30.3% or 10.4% faster than control cells. However, these cells failed to form colonies in soft agar or form tumor in nude mice. 16HBETR, 16HBETM cells obtained transformed phenotype at 5 wks, 11 wks, respectively after treatment with BPDE, which are 15 wks and 9 wks earlier than control cells 16HBETV (20 wks). Meanwhile, 16HBETR, 16HBETM cells obtained transformed phenotype at 11 wks, 14 wks, respectively after treatment with nickel sulfate, which are 21 wks and 18 wks earlier than control cells (32 wks).</p><p><b>CONCLUSION</b>With the advantage of shorter latency, transgenic human cell transformation models could be used in potent carcinogen screening and applied to chemical-carcinogenesis mechanism study.</p>
