Relationship between apoptosis and immunohistochemical staining for proliferating cell nuclear antigen and Ki-67 in non-small cell lung cancer

The relationship between apoptosis and cellular proliferative activity in h uman non-small cell lung cancer (25 cases) was investigated using the in si tu DNA nick-end labeling method and immunohistochemistry for both prolifera ting cell nuclear antigen (PCNA) and Ki-67 antigen. Comparison of the distr ibution of Ki-67-positive cells to that of apoptotic cells shows an inverse correlation in semi-serial sections. The PCNA labeling rates were closely correlated with Ki-67 labeling rates in nonsmall cell hmg cancer: It was co ncluded that the immunostainings of PCNA and Ki-67 were almost equally valu able for assessing the poliferative activity in paraffin-embedded tissue fr om non-small cell lung cancer and that apoptosis may be related with the ce ll cycle in this cancer.