Cyclin D1 and retinoblastoma protein expression in Kaposi's sarcoma.

TitleCyclin D1 and retinoblastoma protein expression in Kaposi's sarcoma.
Publication TypeJournal Article
Year of Publication1997
AuthorsHorenstein MG, Cesarman E, Wang X, Linkov I, Prieto VG, Louie DC
JournalJ Cutan Pathol
Date Published1997 Nov
KeywordsAntibodies, Monoclonal, Blotting, Western, Cyclin D1, Disease Progression, Humans, Immunohistochemistry, Neoplasm Staging, Retinoblastoma Protein, Sarcoma, Kaposi

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 D1 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 D1 and pRb. We detected cyclin D1 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 D1 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 D1. Advanced and disseminated KS lesions tend to have overexpression of endogenous cyclin D1. Therefore, cellular cyclin D1 expression appears to correlate with tumor progression in KS. The endogenous cyclin D1 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.

Alternate JournalJ Cutan Pathol
PubMed ID9449484
Grant ListCA68939 / CA / NCI NIH HHS / United States
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Ethel Cesarman, M.D., Ph.D.

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