[Molecular mechanism of anti-apoptotic action of survivin in NCI-H446 lung cancer cells].

OBJECTIVE: To investigate cell apoptosis induced by survivin ASODN and clarify the precise mechanism of anti-apoptotic action of survivin. METHODS: Cells of lung cancer cell line NCI-H446 were treated with survivin ASODN at different concentrations. The changes of survivin mRNA and protein expression were assessed by RT-PCR and Western blot assay. The apoptosis index (AI) and proliferation index (PI) were determined by flow cytometry (FCM). After 500 mmol/L survivin ASODN treatment, cells were stained with Rh123 to detect changes of mitochondrial membrane potential (deltapsim) by FCM. The concentration of cytoplasmic cytochrome c (cyt-c) was continuously determined by ELISA. Relative activities of caspase-9 and caspase-3 were assessed by colorimetric assay. The expression of caspase-8 protein was measured by Western blot assay. The apoptotic rates of lung cancer cells induced by survivin ASODN with or without mitochondrial permeability transition pole (MPTP) inhibitor CsA treatment were assessed by FCM. RESULTS: Down-regulated survivin mRNA was shown to be in dose-dependent and time-dependent manners. Its maximal effect was achieved at a concentration of 500 nmol/L for 72 h, at which mRNA was down-regulated by 62.7%, the expression of survivin protein in NCI-H446 cells was also obviously decreased. After treatment with survivin ASODN at concentration of 500 mmol/L for 72 h, AI was 48.35%, higher than that of control, lipofectin, NSODN, survivin ASODN 100 mmol/L and 300 mmol/L groups (3.75%, 3.41%, 4.69%, 19.85% and 34.39%, respectively). PI was 24.38%, lower than that of control, lipofectin, NSODN, survivin ASODN100 and 300 mmol/L groups (75.74%, 73.12%, 71.76%, 51.03% and 38.94%, respectively). Deltapsim was decreased in 9.54% of NCI-H446 cells treated with survivin ASODN for 3 h and 97.06% for 24 h. Following it, release of cyt-c from mitochondria to cytosol and activation of caspase-9 and caspase-3 increased significantly. The above mentioned indicators changed with a time-dependent and time diversity relationship. In the presence of CsA, the apoptotic rate of lung cancer cells induced by survivin ASODN was decreased significantly. No up-regrulation and activation in caspase-8 protein was observed. CONCLUSION: Survivin inhibits apoptosis via regulation of mitochondrial-dependent pathway. survivin ASODN can not only induce apoptosis but also inhibit cell proliferation through blocking the expression of survivin mRNA and protein.

[The expression of survivin messenger RNA in sputum and cancerous tissue in human lung cancer].

OBJECTIVE: To study the diagnostic significance of the expression of survivin mRNA in transbronchial biopy samples and sputum samples in lung cancer. METHODS: The resected lung cancer tissues and their para-carcinomatous normal tissue specimens of 41 patients with lung cancer and tissue specimens of 9 patients with benign pulmonary diseases were studied. 110 bronchial biopsy specimens from 80 patients with lung cancer and 30 patients with benign pulmonary diseases and their 160 sputum samples were also evaluated. RT-PCR was performed for the detection of survivin mRNA expression in specimens. The results were compared with their histological or cytological examinations. RESULTS: (1) The positive rate of survivin mRNA in resected lung cancer tissues (29/41; 70.7%) was higher than that in the para-carcinomatous normal tissues (7/41; 17.1%) and the benign pulmonary tissues (1/9; 11.1%, P < 0.05). There was no statistical difference (P > 0.05) in the positive rate of survivin mRNA between para-carcinomatous normal tissues and the benign pulmonary disease tissues. In the bronchial biopsy samples, the positive rate of survivin mRNA in 80 lung cancer tissues (51/80; 63.8%) was also higher than that in the benign pulmonary tissues (4/30; 13.3%, P < 0.05). There were no relationships between survivin mRNA expression and age, sex, histopathological subtype, differentiation, or lymph node metastases of the patients. The sensitivity and specificity of diagnosis for lung cancer by detecting survivin mRNA in resected cancer tissue and transbronchial biopsy tissue were 63.8% - 70.7% and 86.7% - 88.9%, respectively. (2) The sensitivity of cytological examinations combined with detecting survivin mRNA in sputum samples was higher than that of either cytological examination or survivin mRNA detection of sputum samples alone (P < 0.05). The sensitivity of the diagnosis for lung cancer increased from 47.1% (sputum cytology alone) to 80.2% (sputum survivin mRNA detection combined with sputum cytology, P < 0.05) and the negative predictive value increased from 37.9% for sputum cytology alone to 57.9% (P < 0.01) for sputum survivin mRNA detection combined with sputum cytology. The specificity did not change significantly. CONCLUSIONS: Detecting survivin mRNA expression from bronchial biopsy specimens might be used as one of the specific molecular markers for diagnosis of lung cancer, while the detection of survivin mRNA from sputum samples as a new ancillary diagnostic method for lung cancer.

[The effect of cyclosporine A on lipopolysaccharide-induced acute lung injury in mice].

OBJECTIVE: To investigate the effect of mitochondrial permeability transition pore inhibitor cyclosporine A (CsA) on lipopolysaccharide (LPS)-induced acute lung injury in mice. METHODS: All male ICR mice were randomly divided into five groups (n = 24): control group, LPS group, dexamethasone group, cyclosporine A(CsA) group and CsA + atractyloside(Atr) group. Six hours after treatment with LPS, the activity of lactate dehydrogenlase (LDH) in bronchoalveolar lavage fluid (BALF) and level of tumor necrosis factor-alpha (TNF-alpha) in lung tissue were detected. The lung wet weight/dry weight ratio and the pulmonary capillary permeability index were also detected. RESULTS: In contrast to LPS group, the mitochondrial permeability transition pore inhibitor CsA induced a decrease in LDH activity in the BALF and TNF-alpha level in lung tissue, lung wet weight/dry weight ratio and the pulmonary capillary permeability index were declined. Atractyloside, the activator of mitochondrial permeability transition pore, almost abolished the role of CsA on LPS-induced lung injury. CONCLUSION: These results suggested that CsA plays the protective effect on LPS-induced lung injury in mice, it is likely through inhibiting the opening of mitochondrial permeability transition pore.