Analysis of the E-cadherin and P-cadherin promoters in murine keratinocyte cell lines from different stages of mouse skin carcinogenesis.
We previously isolated the 5' upstream sequences of the mouse P-cadherin gene, in which putative binding sites for several transcription factors were identified between nt-101 and +30. In the study reported here, the promoter activity of the postulated 5' cis-acting sequences of the P-cadherin promoter, and the activity of the proximal E-cadherin promoter were investigated in several murine keratinocyte cell lines showing different levels of P- and E-cadherin expression as well as different morphology and tumorigenic behavior. Cell-type specificity and optimal activity of P-cadherin expression in murine keratinocytes was conferred by 5' sequences located between nt -200 and +30, and the GC-rich region (nt -101 to +80) and a CCAAT box element (nt -65) had a major regulatory role. The cell-type specificity of the E-cadherin promoter, on the other hand, was mediated by a combination of positive regulatory elements, a GC-rich region (nt -58 to -24), and a CCAAT box (nt -65) and repressor elements inside the E-pal sequence. Interestingly, the maximum repressor effect of the E-pal element was observed in non-expressing undifferentiated spindle cells. In vitro binding studies indicated that the GC-rich region of the P-cadherin promoter was mainly recognized by Sp1-related nuclear factors, whereas both AP2- and Sp1-related factors were involved in the interaction of the GC-rich region of the E-cadherin promoter. Common factors (probably related to the CP1 family) seemed also to be involved in the recognition of the CCAAT-box element of both the E- and P-cadherin promoters, but additional specific factors participated in the interaction with the CCAAT box of the E-cadherin promoter. Our studies also support the hypothesis that loss or modification of some of the regulatory factors occurs during mouse skin tumor progression.
Faraldo
M L
ML
Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Cientificas, Departamento de Bioquímica, Universidad Autónoma de Madrid, Spain.
Rodrigo
I
I
Behrens
J
J
Birchmeier
W
W
Cano
A
A
D000818:Animals; D001483:Base Sequence; D015820:Cadherins / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D018983:DNA Footprinting; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D015603:Keratinocytes / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000502:physiology*; D012045:Regulatory Sequences, Nucleic Acid; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D014157:Transcription Factors / Q000378:metabolism
D015820:Cadherins; D004273:DNA, Neoplasm; D014157:Transcription Factors