The candidate tumor suppressor gene, RASSF1A, from human chromosome 3p21.3 is involved in kidney tumorigenesis.
Clear cell-type renal cell carcinomas (clear RCC) are characterized almost universally by loss of heterozygosity on chromosome 3p, which usually involves any combination of three regions: 3p25-p26 (harboring the VHL gene), 3p12-p14.2 (containing the FHIT gene), and 3p21-p22, implying inactivation of the resident tumor-suppressor genes (TSGs). For the 3p21-p22 region, the affected TSGs remain, at present, unknown. Recently, the RAS association family 1 gene (isoform RASSF1A), located at 3p21.3, has been identified as a candidate lung and breast TSG. In this report, we demonstrate aberrant silencing by hypermethylation of RASSF1A in both VHL-caused clear RCC tumors and clear RCC without VHL inactivation. We found hypermethylation of RASSF1A's GC-rich putative promoter region in most of analyzed samples, including 39 of 43 primary tumors (91%). The promoter was methylated partially or completely in all 18 RCC cell lines analyzed. Methylation of the GC-rich putative RASSF1A promoter region and loss of transcription of the corresponding mRNA were related causally. RASSF1A expression was reactivated after treatment with 5-aza-2'-deoxycytidine. Forced expression of RASSF1A transcripts in KRC/Y, a renal carcinoma cell line containing a normal and expressed VHL gene, suppressed growth on plastic dishes and anchorage-independent colony formation in soft agar. Mutant RASSF1A had reduced growth suppression activity significantly. These data suggest that RASSF1A is the candidate renal TSG gene for the 3p21.3 region.
Dreijerink
K
K
Laboratory of Immunobiology and Intramural Research Support Program, Science Applications International Corporation, National Cancer Institute, Frederick, MD 21702, USA.
Braga
E
E
Kuzmin
I
I
Geil
L
L
Duh
F M
FM
Angeloni
D
D
Zbar
B
B
Lerman
M I
MI
Stanbridge
E J
EJ
Minna
J D
JD
Protopopov
A
A
Li
J
J
Kashuba
V
V
Klein
G
G
Zabarovsky
E R
ER
D001374:Azacitidine / Q000494:pharmacology; D002292:Carcinoma, Renal Cell / Q000235:genetics*; D002448:Cell Adhesion; D002455:Cell Division / Q000187:drug effects; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3; D019175:DNA Methylation; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000737:chemistry / Q000378:metabolism; D004318:Doxycycline / Q000633:toxicity; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016147:Genes, Tumor Suppressor; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D017931:DNA Primers; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; C411762:RASSF1 protein, human; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; D001374:Azacitidine; D004318:Doxycycline