Cyclin D1 expression and HHV8 in Kaposi sarcoma.
BACKGROUND
Human herpesvirus 8 (HHV8) appears to be the agent responsible for Kaposi sarcoma. The mechanism remains undetermined but may involve cell cycle regulating genes including D type cyclins which are pivotal in cell cycle progression. Recent HHV8 genetic analysis has revealed the presence of a v-cyclin which is homologous to D type cyclins.


OBJECTIVE
First, to assess whether there is an independent relation between endogenous cyclin D1 expression in Kaposi sarcoma and HHV8 status; second to determine whether v-cyclin mRNA expression varies with Kaposi sarcoma stage.


METHODS
Cyclin D1 immunohistochemistry was performed on 17 paraffin embedded Kaposi sarcoma samples from 16 patients. HHV8 status was assessed in 15 of these using nested polymerase chain reaction (PCR) to ORF 26 and the newly described technique of TaqMan PCR. An additional 10 fresh Kaposi sarcoma samples (early and nodular) were examined for HHV8 v-cyclin RNA.


RESULTS
One case, which did not contain amplifiable HHV8, showed strong cyclin D1 staining. The remaining cases were negative or weakly staining; v-cyclin transcript load was higher in early Kaposi sarcoma.


CONCLUSIONS
While endogenous cyclin D1 expression is independent of HHV8 status, v-cyclin transcription is higher in early lesions, supporting the "viral hit" hypothesis.
Kennedy
M M
MM
Nuffield Department of Pathology and Bacteriology, University of Oxford, UK.
Biddolph
S
S
Lucas
S B
SB
Howells
D D
DD
Picton
S
S
McGee
J O
JO
Silva
I
I
Uhlmann
V
V
Luttich
K
K
O'Leary
J J
JJ
D019938:Cyclin D1 / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D019288:Herpesvirus 8, Human / Q000302:isolation & purification*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D012514:Sarcoma, Kaposi / Q000378:metabolism / Q000821:virology*; D014764:Viral Proteins / Q000378:metabolism
C118264:HHV8-Vcyc protein, Human herpesvirus 8; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D019938:Cyclin D1