Downregulation of BRCA1 in A375 melanoma cell line increases radio-sensitivity and modifies metastatic and angiogenic gene expression.
The participation of BRCA1 (breast cancer 1) in DNA repair is well established, especially in mammary and ovarian cells. Our purpose was to develop a new in vivo radio-sensitizing therapy for melanoma. We therefore investigated the effect of downregulation of BRCA1 on irradiated melanoma cells using an anti-BRCA1 ribozyme. Our results show that BRCA1 downregulation increased radio-sensitivity of the A375 cell line, suggesting that BRCA1 could act as a caretaker in melanoma; however, as BRCA1 functions are not limited to maintaining genomic integrity but also regulate transcription and the cell cycle, we confirmed that the proliferative rate of BRCA1 downregulated clones did not change. We also demonstrate that: (1) among the major pro-angiogenic genes, FGF-2 was not increased before or after irradiation and vascular endothelial growth factor strongly inhibited after irradiation; (2) expression of two important metalloproteinases, matrix metalloproteinase 2 and 9, involved in melanoma metastasis were decreased before and after irradiation; (3) expression of their major inhibitor, tissue inhibitor of metalloproteinase, was mainly upregulated; and (4) that invasion of BRCA1 downregulated cells was modified. Together these data suggest that BRCA1 downregulation in melanoma cells did not make them more aggressive and could lead to new therapeutic strategies for this tumor, which is so difficult to control once metastasized.
Laboratoire d'Oncologie Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France.
Cédric
C
Hesling
Michel
M
D'Incan
Chantal
C
D'Incan
Pierre
P
Souteyrand
Jean-Claude
JC
Monboisse
Sylvie
S
Pasco
Jean-Claude
JC
Madelmont
Yves Jean
YJ
Bignon
D052160:Benzothiazoles; D002352:Carrier Proteins / Q000235:genetics*; D002455:Cell Division / Q000502:physiology / Q000528:radiation effects; D045744:Cell Line, Tumor / Q000502:physiology / Q000528:radiation effects; D002470:Cell Survival / Q000502:physiology / Q000528:radiation effects; D003959:Diamines; D015536:Down-Regulation; D016222:Fibroblast Growth Factor 2 / Q000235:genetics; D005456:Fluorescent Dyes; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects*; D006801:Humans; D059648:Kisspeptins; D020781:Matrix Metalloproteinase 1 / Q000235:genetics; D020778:Matrix Metalloproteinase 2 / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D008545:Melanoma / Q000235:genetics*; D009389:Neovascularization, Pathologic / Q000235:genetics*; D009930:Organic Chemicals; D011506:Proteins / Q000235:genetics; D011804:Quinolines; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012878:Skin Neoplasms / Q000235:genetics*; D019700:Thrombospondin 1 / Q000235:genetics; D019699:Thrombospondins / Q000235:genetics; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D000099262:Thrombospondin 2
D052160:Benzothiazoles; D002352:Carrier Proteins; D003959:Diamines; D016222:Fibroblast Growth Factor 2; D005456:Fluorescent Dyes; D059648:Kisspeptins; D020781:Matrix Metalloproteinase 1; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D009930:Organic Chemicals; D011506:Proteins; D011804:Quinolines; D019700:Thrombospondin 1; D019699:Thrombospondins; D019715:Tissue Inhibitor of Metalloproteinase-1; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D042461:Vascular Endothelial Growth Factor A; D000099262:Thrombospondin 2; C106628:KISS1 protein, human; C098022:SYBR Green I; C111164:BRAP protein, human