ckshs expression is linked to cell proliferation in normal and malignant human lymphoid cells.
Cyclin kinase sub-units (CKS) are known to interact with cyclin-dependent kinases (CDKs), but their functions are not completely understood and their expression in human tissues is not documented. For analyzing relationships of CKS with cell proliferation and/or with differentiation, we investigated the expression of ckshs1 and ckshs2 in normal and malignant human lymphoid cells. ckshs1 and ckshs2 expression appeared to be related to cell proliferation: (i) mRNAs increased with stimulation of normal peripheral-blood lymphocytes, and from the G1 to the SG2M phase in elutriated cells; (ii) P9 proteins were also induced by lymphocyte stimulation and were localized in nucleus where phosphorylated forms of CDK1 were also found; (iii) in vitro, the phosphorylated forms of CDK1 and CDK2 were preferentially linked to CKS. Among 45 patients presenting acute or chronic lymphoid malignancy, ckshs1 and ckshs2 mRNAs varied in a similar way and were significantly correlated to cell proliferation (p < 0.0001). When analysis was restricted solely to acute lymphoblastic leukemia (ALL) this correlation was still found and ckshs1 and ckshs2 were significantly more expressed in T-cell ALL than in B-cell-lineage ALL. These results confirm relationships between ckshs expression and cell proliferation, and pose the question of a link with cell differentiation.
Urbanowicz-Kachnowicz
I
I
Laboratoire de Cytologie Analytique, Université Claude Bernard, Lyon, France.
Baghdassarian
N
N
Nakache
C
C
Gracia
D
D
Mekki
Y
Y
Bryon
P A
PA
Ffrench
M
M
D000818:Animals; D042846:CDC2-CDC28 Kinases; D002352:Carrier Proteins / Q000235:genetics*; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002455:Cell Division; D002460:Cell Line; D018844:Cyclin-Dependent Kinases; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism* / Q000473:pathology; D011494:Protein Kinases; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits
C093090:CKS1B protein, human; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D012333:RNA, Messenger; D011494:Protein Kinases; D042846:CDC2-CDC28 Kinases; C083689:CKS2 protein, human; D018844:Cyclin-Dependent Kinases