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Cyclin D1 and retinoblastoma protein expression in Kaposi's sarcoma
Author(s) -
Horenstein Marcelo G.,
Cesarman Ethel,
Wang Xiao,
Linkov Irina,
Prieto Victor G.,
Louie Diane C.
Publication year - 1997
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/j.1600-0560.1997.tb01088.x
Subject(s) - retinoblastoma protein , cyclin d1 , cyclin , cyclin d , biology , cancer research , cyclin e , cyclin a , cyclin b , cyclin a2 , cell cycle , microbiology and biotechnology , cell , biochemistry
Cyclins are implicated in the induction and control of the cell cycle. Cyclin D1 regulates G1‐phase progression by phosphorylation of the retinoblastoma protein (pRb). The Kaposi's sarcoma‐associated herpesvirus/human herpesvirus 8 (KSHV) contains and transcribes an open reading frame with sequence similarities to cellular D‐type cyclins. The KSHV‐cyclin protein is associated with kinase activity capable of phosphorylating pRb in vitro. Here, we study for the first time the endogenous cyclin Dl and Rb protein expression in Kaposi's sarcoma (KS) tissue. Twenty‐four consecutive biopsies of AIDS‐related (n=21) and classical (n=3) KS were studied by immunohistochemistry with monoclonal antibodies against cyclin Dl and pRb. We detected cyclin Dl in 1 of 13 patch/plaque stage, in 4 of 5 nodular stage and in 3 of 6 visceral KS lesions. By Western blot analysis, this cellular cyclin Dl monoclonal antibody did not cross‐react with the purified KSHV‐cyclin protein. The pRb was consistently detected in 24 of 24 KS lesions. In summary, early KS lesions rarely have detectable expression of endogenous cyclin Dl. Advanced and disseminated KS lesions tend to have overexpression of endogenous cyclin Dl. Therefore, cellular cyclin Dl expression appears to correlate with tumor progression in KS. The endogenous cyclin Dl is antigenically distinct from the KSHV‐cyclin homolog. The pRb, which may serve as a substrate for KSHV‐cyclin, is found in all KS lesions examined.