Expression of Ki-67, Bcl-2, Survivin and p53 Proteins in Patients with Pulmonary Carcinoma.

Apoptosis is the fundamental process necessary for eliminating damaged or mutated cells. Alterations in the apoptotic pathway appear to be key events in cancer development and progression. Bcl-2 is the key member of the Bcl-2 family of apoptosis regulator proteins with anti-apoptotic effects. Survivin acts as an inhibitor of apoptosis as well and has been implicated in both inhibition of apoptosis and mitosis regulation. p53 is one of the tumor suppressor proteins, prevents tumor formation through cell cycle blocking and eliminates damaged cells via the activation of apoptosis. The Ki-67 protein is a cellular marker for proliferation. To investigate the possible interactions of the aforementioned proteins, we examined their expression in 76 patients with diagnosed lung cancer using immunohistochemical visualisation. Ki-67 protein was expressed in the cancer cells of all patients with small cell lung cancer (SCLC). We found a negative correlation between survivin and p53 expression. A decreased intensity of survivin expression and fewer cells positive for survivin (66.7%) in SCLC in comparison with other lung cancer types (98.0%) was detected. Reversely, expression of Bcl-2 was found in more than 90% of cases with SCLC. We hypothesize that high expression and intensity of Bcl-2 protein could be a factor behind a bad prognosis in SCLC.

Lung cancer incidence and survival in chromium exposed individuals with respect to expression of anti-apoptotic protein survivin and tumor suppressor P53 protein.

OBJECTIVE: Workers chronically exposed to hexavalent chromium have elevated risk of lung cancer. Our study investigates the incidence of lung cancer types, age at onset of the disease, and survival time among chromium exposed workers with respect to the expression of anti-apoptotic p53 and pro-apoptotic survivin proteins. MATERIAL AND METHODS: 67 chromium exposed workers and 104 male controls diagnosed with lung cancer were analyzed. The mean exposure time among workers was 16.7 ±10.0(SD) years (range 1- 41 years). To investigate the possible regulation of survivin by p53 we examined the expression of both proteins using immohistochemical visualization. RESULTS: Chromium exposure significantly decreases the age of onset of the disease by 3.5 years (62.2 ±9.1 in the exposed group vs. 65.7 ±10.5 years in controls; P=0.018). Small cell lung carcinoma (SCLC) amounted for 25.4% of all cases in chromium exposed workers and for 16.3% in non-exposed individuals. The mean survival time in the exposed group was 9.0 ±12.7 vs. 12.1 ±21.9 months in controls, but this difference was not significant. Survivin was predominantly expressed in both cell nucleus and cytoplasm, whereas p53 was expressed in the nucleus. There was a negative correlation between survivin and p53 expression. A decreased intensity of expression and fewer cells positive for survivin was detected in SCLC compared with other types of lung cancer. p53 was expressed in 94.1% and survivin in 79.6% of the samples analyzed. CONCLUSION: The study calls attention to decreased expression of survivin, as opposed to p53, in small cell lung carcinoma.

Expression of anti-apoptotic protein survivin and tumor suppressor p53 protein in patients with pulmonary carcinoma.

BACKGROUND: Survivin is one of the inhibitors of the apoptosis gene family that has been implicated in both inhibition of apoptosis and mitosis regulation. p53 is one of the tumor suppressor genes; prevents tumor formation through cell cycle blocking and eliminates damaged cells via activation of apoptosis. OBJECTIVE: To investigate the possible regulation of survivin by p53, we examined the expression of both proteins in 67 patients with diagnosed lung cancer using immunohistochemical visualization. RESULTS: Survivin was predominantly expressed in both nucleus and cytoplasm, whereas p53 was expressed in the nucleus. There was a negative correlation between survivin and p53 expression. A decreased intensity of expression and fewer cells positive for survivin in small cell lung cancer in comparison with other lung cancer types were detected. There was no significant difference in the intensity of expression and the number of cells positive for p53 between small cell and non-small cell lung cancer types. CONCLUSION: The present study suggests that survivin expression, as opposed to that of p53, is decreased in small cell lung cancer, which may differentiate this cancer from other lung cancer types other types.