Expression of Epstein-Barr virus latent infection genes and oncogenes in lymphoma cell lines derived from pyothorax-associated lymphoma

✍ Scribed by Hiroyuki Kanno; Yutaka Yasunaga; Masahiko Ohsawa; Masafumi Taniwaki; Keiji It chi; Norifumi Naka; Kei Torikai; Masanori Shimoyama; Katsuyuki Aozasa

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: French
• Weight: 857 KB
• Volume: 67
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19960703)67:1<86::aid-ijc15>3.0.co;2-a

✦ Synopsis

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. The term pyothoraxassociated lymphoma (PAL) has been proposed for this type of tumor. Most PALs are diffuse lymphomas of the B-cell type and contain Epstein-Barr virus (EBV) DNA. We have established 2 lymphoma cell lines from biopsy specimens of PAL cases, OPL-I and OPL-2. and examined their growth characteristics and the expression of EBV latent infection genes and oncogenes. OPL-2 exhibited a more rapid growth and higher saturation density than OPL-I, and only OPL-2 exhibited colony-forming activity in soft agar. OPL-I and -2 were positive for B-cell differentiation markers and showed clonal surface immunoglobulins. Both lines contained a single predominant form of episomal EBV DNA, indicating clonal cellular proliferation of an EBV-infected progenitor cell. OPL-I and -2 contained type B and A EBV genome, respectively. Expression of EBV nuclear antigen (EBNA)2 mRNA and protein was detected by Northern and Western blot analysis in OPL-I, but not in OPL-2. On the other hand, the expression of latent membrane protein (LMP) I mRNA in both OPL-I and -2 was extremely weak and detectable only by reverse transcription-polymerase chain reaction. Protein expression of LMPl was not observed by Western blot analysis or immunocytochemistry. Both lines expressed c-myc mRNA. Only OPL-I expressed mRNA of c-fgr, an oncogene whose expression is upregulated by EBNA2. Both OPLs expressed bcl-2 mRNA without detectable expression of LMPl protein.