The absence of p 21 Cipl / wAF 1 alters keratinocyte growth and differentiation and promotes r a s-t u m o r progression

p21Cipl/wAF1 was the first cyclin-dependent kinase (CDK) inhibitor to be identified, as a mediator of p53 in D N A damage-induced growth arrest, cell senescence, and direct CDK regulation, p21 may also play an important role in differentiation-associated growth arrest, as its expression is augmented in many terminally differentiating cells. A general involvement of p21 in growth/differentiation control and tumor suppression has been questioned, as mice lacking p21 undergo a normal development, harbor no gross alterations in any of their organs, and exhibit no increase in spontaneous tumor development. However, a significant imbalance between growth and differentiation could be unmasked under conditions where normal homeostatic mechanisms are impaired. We report here that primary keratinocytes derived from p21 knockout mice, transformed with a ras oncogene, and injected subcutaneously into nude mice exhibit a very aggressive tumorigenic behavior, which is not observed with wild-type control keratinocytes nor with keratinocytes with a disruption of the closely related p27 gene. p21 knockout keratinocytes tested under well-defined in vitro conditions show a significantly increased proliferative potential, which is also observed but to a lesser extent with p27 knockout cells. More profound differences were found in the differentiation behavior of p21 versus p27 knockout keratinocytes, with p21 (but not p27) deficiency causing a drastic down-modulation of differentiation markers linked with the late stages of the keratinocyte terminal differentiation program. Thus, our results reveal a so far undetected role of p21 in tumor suppression, demonstrate that this function is specific as it cannot be attributed to the closely related p27 molecule, and point to an essential involvement of p21 in terminal differentiation control, which may account for its role in tumor suppression.

[1]  K. Kinzler,et al.  p 53-Dependent and independent expression of p 21 during cell growth , differentiation , and DNA damage , 2007 .

[2]  Nobuyuki Shishido,et al.  Mice Lacking p27 Kip1 Display Increased Body Size, Multiple Organ Hyperplasia, Retinal Dysplasia, and Pituitary Tumors , 1996, Cell.

[3]  James M. Roberts,et al.  A Syndrome of Multiorgan Hyperplasia with Features of Gigantism, Tumorigenesis, and Female Sterility in p27 Kip1 -Deficient Mice , 1996, Cell.

[4]  K. Manova-Todorova,et al.  Enhanced Growth of Mice Lacking the Cyclin-Dependent Kinase Inhibitor Function of p27 Kip1 , 1996, Cell.

[5]  L. Tsai,et al.  The brain-specific activator p35 allows Cdk5 to escape inhibition by p27Kip1 in neurons. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[6]  L. Chin,et al.  Role of the INK4a Locus in Tumor Suppression and Cell Mortality , 1996, Cell.

[7]  James Brugarolas,et al.  Radiation-induced cell cycle arrest compromised by p21 deficiency , 1995, Nature.

[8]  E. Nabel,et al.  The p21 cyclin–dependent kinase inhibitor suppresses tumorigenicity in vivo , 1995, Nature Medicine.

[9]  A. Zantema,et al.  Inhibition of cyclin-dependent kinase activity triggers neuronal differentiation of mouse neuroblastoma cells , 1995, The Journal of cell biology.

[10]  R. Ezzell,et al.  fyn tyrosine kinase is involved in keratinocyte differentiation control. , 1995, Genes & development.

[11]  H. Moses,et al.  Transforming growth factor beta 1 inhibits mouse keratinocytes late in G1 independent of effects on gene transcription. , 1995, Cancer research.

[12]  Stephen J. Elledge,et al.  Mice Lacking p21 CIP1/WAF1 undergo normal development, but are defective in G1 checkpoint control , 1995, Cell.

[13]  A. Iavarone,et al.  Kip/Cip and Ink4 Cdk inhibitors cooperate to induce cell cycle arrest in response to TGF-beta. , 1995, Genes & development.

[14]  B. Dynlacht,et al.  p107 uses a p21CIP1-related domain to bind cyclin/cdk2 and regulate interactions with E2F. , 1995, Genes & development.

[15]  L. Tsai,et al.  Involvement of the cell-cycle inhibitor Cip1/WAF1 and the E1A-associated p300 protein in terminal differentiation. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[16]  J. Massagué,et al.  Cell-cycle inhibition by independent CDK and PCNA binding domains in p21Cip1 , 1995, Nature.

[17]  Z. Su,et al.  The melanoma differentiation-associated gene mda-6, which encodes the cyclin-dependent kinase inhibitor p21, is differentially expressed during growth, differentiation and progression in human melanoma cells. , 1995, Oncogene.

[18]  M. Kirschner,et al.  Separate domains of p21 involved in the inhibition of Cdk kinase and PCNA , 1995, Nature.

[19]  G. Hannon,et al.  Correlation of terminal cell cycle arrest of skeletal muscle with induction of p21 by MyoD , 1995, Science.

[20]  S. Elledge,et al.  p53-independent expression of p21Cip1 in muscle and other terminally differentiating cells , 1995, Science.

[21]  James M. Roberts,et al.  lnterleukin-2-mediated elimination of the p27Kipl cyclin-dependent kinase inhibitor prevented by rapamycin , 1994, Nature.

[22]  C. Sherr.  G1 phase progression: Cycling on cue , 1994, Cell.

[23]  J. Massagué,et al.  Cyclic AMP-induced G1 phase arrest mediated by an inhibitor (p27 Kip1 ) of cyclin-dependent kinase 4 activation , 1994, Cell.

[24]  Z. Su,et al.  Induction of differentiation in human promyelocytic HL-60 leukemia cells activates p21, WAF1/CIP1, expression in the absence of p53. , 1994, Oncogene.

[25]  G. Hannon,et al.  Differential effects by the p21 CDK inhibitor on PCNA-dependent DNA replication and repair , 1994, Nature.

[26]  R. Weinberg,et al.  Extensive contribution of Rb‐deficient cells to adult chimeric mice with limited histopathological consequences. , 1994, The EMBO journal.

[27]  James M. Roberts,et al.  Cloning of p27 Kip1 , a cyclin-dependent kinase inhibitor and a potential mediator of extracellular antimitogenic signals , 1994, Cell.

[28]  G. Hannon,et al.  The p21 inhibitor of cyclin-dependent kinases controls DNA replication by interaction with PCNA , 1994, Nature.

[29]  J. R. Smith,et al.  Cloning of senescent cell-derived inhibitors of DNA synthesis using an expression screen. , 1994, Experimental cell research.

[30]  R. Weinberg,et al.  Tumor spectrum analysis in p53-mutant mice , 1994, Current Biology.

[31]  David Beach,et al.  p21 is a universal inhibitor of cyclin kinases , 1993, Nature.

[32]  L. Donehower,et al.  Reduction of p53 gene dosage does not increase initiation or promotion but enhances malignant progression of chemically induced skin tumors , 1993, Cell.

[33]  S. Yuspa,et al.  Coordinate changes in gene expression which mark the spinous to granular cell transition in epidermis are regulated by protein kinase C , 1993, The Journal of cell biology.

[34]  C. Missero,et al.  Different levels of v‐Ha‐ras p21 expression in primary keratinocytes transformed with harvey sarcoma virus correlate with benign versus malignant behavior , 1993, Molecular carcinogenesis.

[35]  S. Reed,et al.  Association of human cyclin E with a periodic G1-S phase protein kinase. , 1992, Science.

[36]  C. Marshall.  Tumor suppressor genes , 1991, Cell.

[37]  A. Pardee.  G1 events and regulation of cell proliferation. , 1989, Science.

[38]  T. Palmer,et al.  Efficient retrovirus-mediated transfer and expression of a human adenosine deaminase gene in diploid skin fibroblasts from an adenosine deaminase-deficient human. , 1987, Proceedings of the National Academy of Sciences of the United States of America.

[39]  D. Lowy,et al.  An activated Harvey ras oncogene produces benign tumours on mouse epidermal tissue , 1986, Nature.

[40]  R. Weinberg,et al.  Specific growth response of ras-transformed embryo fibroblasts to tumour promoters , 1985, Nature.

[41]  Karen Holbrook,et al.  Calcium regulation of growth and differentiation of mouse epidermal cells in culture , 1980, Cell.