RESUMO
The relationship between nitric oxide synthase II (NOS II) inducibility and the metastatic ability of UV-2237 murine fibrosarcoma cells was determined. Highly metastatic cells survived to produce numerous lung metastases after i.v. injection in syngeneic C3H/HeN mice, whereas poorly metastatic cells did not. Highly metastatic clones exhibited higher levels of NOS II than did poorly metastatic clones in response to interleukin 1alpha and IFN-gamma stimulation. Furthermore, both poorly and highly metastatic clones contained an identical p53 mutation. Overexpression of NOS II in a highly metastatic clone by transfection with NOS II gene retarded tumor growth and completely suppressed metastasis. Our data indicate that a low to moderate level of NOS II expression directly correlates with metastatic ability of UV-2237 fibrosarcoma cells carrying mutant p53 and that a high level of nitric oxide production suppresses tumor growth and metastasis.
Assuntos
Fibrossarcoma/patologia , Genes p53 , Metástase Neoplásica/genética , Proteínas de Neoplasias/biossíntese , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico/fisiologia , Animais , Indução Enzimática , Fibrossarcoma/genética , Camundongos , Camundongos Endogâmicos C3H , Proteínas de Neoplasias/genética , Transplante de Neoplasias , Neoplasias Induzidas por Radiação/genética , Neoplasias Induzidas por Radiação/patologia , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase Tipo II , Proteínas Recombinantes de Fusão/fisiologia , Transfecção , Células Tumorais CultivadasRESUMO
Deciphering the genetic mechanisms in cancer development requires analysis of a large number of tumors for consistent genetic alterations. Single-strand conformational polymorphism (SSCP) analysis is a fast and efficient method for detecting mutations, deletions, insertions and loss of alleles. The primary advantage of this method is speed and ability to screen a large number of samples at one time. Here we report the use of the SSCP technique for rapidly screening tumor and normal tissues for mutations and polymorphisms in the p53 tumor suppressor gene. Because the DNA extracted from specific aberrant bands from different samples always give rise to the same nucleotide sequence upon sequencing analysis, the SSCP technique can be used as a diagnostic tool to identify the presence of such genetic alterations without having to spend time on further sequencing analysis.