WGA and SBA reduced levels of B cell lymphoma-2 (Bcl-2), phosphorylation of Bcl-2-associated death promoter (Bad), cyclin-dependent kinase 4 (Cdk4), and phosphorylation of the retinoblastoma (Rb).
Collectively, these findings establish a context-specific tumor suppressor function for CDK4 that prevents genomic instability, which contributes to B cell lymphoma.
To compare the expression status of G1 cyclins, these EBV-associated lymphoma lines (6 EBV[-] human SCID mouse lymphoma lines, 13 human B cell lymphomas and 8 samples of human tonsil tissue) were examined by reverse transcription-polymerase chain reaction-Southern blotting, Western blotting and immunohistochemistry. mRNA expression of cyclin D1 (CCND1), cyclin D2 (CCND2), cyclin E (CCNE), cyclin-dependent kinase 2 (CDK2) and 4 (CDK4) was found in all 3 types of lymphomas.
Twenty primary central nervous system lymphomas (PCNSL) from immunocompetent patients (nineteen B-cell lymphomas and one T-cell lymphoma) were investigated for genetic alterations and/or expression of the genes BCL2, CCND1, CDK4, CDKN1A, CDKN2A, MDM2, MYC, RB1, REL, and TP53.