In vitro thymidine labeling indices of human lung cancers and squamous metaplasia of the bronchus were measured employing autoradiography for the assessment of tumor cell proliferation.
The tissues for culture were obtained with fiberoptic bronchoscopic biopsy from the 15 patients. The biopsy specimens consisted of six squamous cell carcinomas, four small cell carcinomas, and five squamous metaplasias. The biopsy specimens were incubated with Eagle´s MEM culture media containing tritiated thymidine (specific activity, 20Ci/mmol) for 30 minutes.
The mean value with standard deviation of thymidine labeling indices was 19.65 5.92 % for squamous cell carcinomas, 18.57 5.77% for small cell carcinomas, and 7.82 + 2.53% for squamous metaplasias, respectively. A wide range of individual labeling indices was noticed in the lung cancers.
In conclusion, tritiated thymidine labeling indices of human lung cancers were significantly, higher than those of squamous metaplasia.
|