[Small cell carcinoma and carcinoids of the lung: morphology of apoptosis and expression of biomolecular markers of tumor growth]. / Melkokletochnyii rak i kartsinoidy legkikh: morfologiia apoptoza i ékspressiia biomolekuliarnykh markerov opukholevogo rosta.

Neuroendocrine lung tumors (NELT) from 50 patients were studied immunohistochemically. Malignant carcinoid and small-cell lung carcinoma (SCC) have a higher level of apoptosis than ordinary carcinoid. An increase of apoptosis index in NELT coincides with an increase in NELT proliferative activity (Ki-67, Bcl-2, c-myc, p-53) as compared to a typical carcinoid. Phagocytosis of apoptotic bodies was absent in SCC. Classic SCC differs from combined SCC by a higher apoptosis index and lower expression of p-53 and Bcl-2. Metastatic SCC differs from SCC without metastases by lower apoptosis level and higher level of proliferative indices (Ki-67, Bcl-2) of tumor cells. Development of unbalance between apoptosis and proliferation may result from mitosis and apoptosis pathology.

Role of Bcl-2, Bax, and Bak in spontaneous apoptosis and proliferation in neuroendocrine lung tumors: immunohistochemical study.

Fifty-six primary neuroendocrine lung tumors were examined morphologically and histologically and their apoptosis level was determined. Malignant carcinomas were characterized by increased apoptotic index and enhanced expression ofBcl-2, Bak, p53, and Ki-67 compared to typical carcinoid. However, apoptosis in these tumors was not completed. Proteins of the Bcl family play an important role in the regulation of spontaneous apoptosis in neuroendocrine lung tumors. Bcl-2 accumulating in the nucleus is a morphological analogue of phosphorylated inactive form of this protein, which does not inhibit apoptosis. Expression of Bcl-2 and Bax decreases in small-cell lung carcinoma (SCLC) with metastases indicating attenuation of apoptosis and development of metastatic clones resistant to apoptosis induces.