Melanocyte and keratinocyte carcinogenesis: p53 family protein activities and intersecting mRNA expression profiles.
Melanocytes and keratinocytes were analyzed for potential roles of p53, p73, and p63 tumor suppressor family proteins and of malignancy-specific gene expression changes in the etiology of multi-step cancer. Melanocytes expressed deltaNp73alpha, two p63 isoforms and p53. Although p21 and Noxa mRNA levels increased following DNA damage, p53 family member binding to p21 and Noxa DNA probes was undetectable, suggesting p53 family-independent responses. In contrast, keratinocytes expressed multiple isoforms each of p73 and p63 that were induced to bind p21 and Noxa DNA probes after ionizing (IR) or after ultraviolet B (UVB) irradiation, correlating with p21 and Noxa mRNA induction and with apoptosis. Interestingly, IR-resistant malignant melanocytes and keratinocytes both exhibited Noxa mRNA induction after UVB treatment, correlating with DNA binding of p53 family proteins to the Noxa probe only in keratinocytes. To uncover other malignancy-specific events, we queried mouse initiated keratinocyte clones for early changes that were exacerbated in malignant derivatives and also differentially expressed in human advanced melanoma versus normal melanocytes. Using a new method for ranking and normalization of microarray data for 5000 probe sets, 27 upregulated and 13 downregulated genes satisfied our query. Of these, the majority was associated with late-stage human cancers and six were novel genes. Thus, clonal lineage mouse models representing early through late cancer progression stages may inform the focus on early, potentially causal events from microarray studies of human cancers, facilitating prognosis and molecular therapy.
Kulesz-Martin
Molly
M
Department of Dermatology, Oregon Health & Science University, Portland, Oregon 97239, USA. kuleszma@ohsu.edu
Lagowski
James
J
Fei
Suzanne
S
Pelz
Carl
C
Sears
Rosalie
R
Powell
Marianne Broome
MB
Halaban
Ruth
R
Johnson
Jodi
J
D000818:Animals; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology*; D020869:Gene Expression Profiling; D016147:Genes, Tumor Suppressor / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D008544:Melanocytes / Q000378:metabolism*; D051379:Mice; D009687:Nuclear Proteins / Q000502:physiology*; D010750:Phosphoproteins / Q000502:physiology*; D012878:Skin Neoplasms / Q000209:etiology*; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*; D025521:Tumor Suppressor Proteins
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C115051:TP63 protein, human; C000606460:TP73 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; C000606368:Trp73 protein, mouse; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D004247:DNA