Ras Gene alterations in invasive and non-invasive rat bladder carcinomas induced by N-methyl-N-nitrosourea
1991

Ras Gene Changes in Rat Bladder Cancer

Sample size: 62 publication Evidence: moderate

Author Information

Author(s): Y. Yura, M. Azuma, K. Uchida, H. Momose, R. Oyasu

Primary Institution: Northwestern University Medical School

Hypothesis

The study aims to investigate the role of ras gene alterations in the development of invasive and non-invasive rat bladder carcinomas induced by N-methyl-N-nitrosourea (MNU).

Conclusion

The study found that about half of the non-invasive and invasive carcinomas induced by MNU contained activated ras oncogenes or the oncogene product p21, but this activation did not correlate with the aggressiveness of the tumors.

Supporting Evidence

  • The incidence of muscle-invasive carcinomas was proportional to the total dose of MNU administered.
  • Activated H-ras gene was detected in only one non-invasive carcinoma.
  • Seven of 18 carcinomas showed activated ras p21 when examined by immunoblot analysis.

Takeaway

Researchers gave rats a chemical to see if it would cause bladder cancer and found that some tumors had changes in a specific gene, but those changes didn't always mean the cancer was worse.

Methodology

The study used a heterotopically transplanted urinary bladder system in rats to induce carcinomas through repeated injections of MNU and examined the alterations in ras oncogenes and their products.

Limitations

The study's findings may not fully represent human bladder cancer due to differences in tumor biology between species.

Participant Demographics

Male Fischer 344 rats were used in the study.

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