[Changes of centrosome and related protein in malignant transformation of BEAS-2B cell induced by coal tar pitch smoke extracts].

OBJECTIVE: To analyze the centrosome abnormalities in the malignant transformation of human bronchial epithelial cells (BEAS-2B) induced by coal tar pitch smoke extracts and to investigate the role and action mechanism of centrosome in the lung cancer induced by coal tar pitch. METHODS: Medium-temperature coal tar pitch smoke extracts were used to treat immortalized human bronchial epithelial cells (BEAS-2B) and establish a malignant transformation model. The treated BEAS-2B cells were used as exposure group, and solvent control group and normal control group were also set for passage culture. The changes of centrosome in BEAS-2B cells seeded on coverslips were evaluated by indirect immunofluorescence assay. The mRNA expression of p53, p21, and cyclin E in BEAS-2B cells was measured by real-time quantitative RT-PCR, and their protein levels in BEAS-2B cells seeded on coverslips were measured by semiquantitative immunohistochemical analysis. RESULTS: The overall rate of centrosome abnormalities in BEAS-2B cells at passage 20 was 6.56±1.01% in the exposure group, significantly higher than those in the normal control group (3.40±0.86%) and solvent control group (3.14±0.59%) (P < 0.05). In addition, the exposure group had a significantly higher overall rate of centrosome abnormalities in BEAS-2B cells at passage 30 compared with the normal control group and solvent control group (22.39±9.5% vs 4.34±1.04%, P < 0.05; 22.39±9.5% vs 4.33±1.20%, P < 0.05). Compared with the normal control group and solvent control group, the exposure group had significantly decreased mRNA and protein expression of p53 and significantly increased mRNA and protein expression of cyclin E in BEAS-2B cells at passages 20 and 30 (P < 0.05). CONCLUSION: Centrosome abnormalities occur before the malignant transformation in BEAS-2B cells treated with coal tar pitch smoke extracts, and they may be mediated by the p53/p21/cyclin E signaling pathway.

[The change of telomere protein in BEAS-2B malignant transformation cell induced by coal tar pitch smoke extracts].

OBJECTIVE: By testing the changes of telomere binding protein in malignant transformation BEAS-2B cells induced by coal tar pitch smoke extracts, to study the role of protection of telomeres 1 (POT1), telomeric repeat binding factor 1 (TRF1) and TRF2 in tumorgenesis that contact with coal tar pitch. METHODS: The BEAS-2B cells were induced by coal tar pitch smoke extracts to form malignant transformation cell model in vitro. The gene expression levels of mRNA were assessed by real-time quantitative RT-PCR, the protein expression variations were determined by cell culture overslip of immunohistochemical methods. RESULTS: In malignant transformation cells, the mRNA expression level (POT1: 0.63 ± 0.04, TRF1: 0.36 ± 0.01) and the protein expression level (POT1: 0.36 ± 0.05, TRF1: 0.09 ± 0.03) of POT1 and TRF1 was statistically significant decreased compared to that of BEAS-2B group (mRNA: POT1: 1.00 ± 0.04, TRF1: 1.01 ± 0.16; protein: POT1: 0.55 ± 0.07, TRF1: 0.27 ± 0.07) and DMSO group (mRNA: POT1: 0.89 ± 0.12, TRF1: 0.90 ± 0.08; protein: POT1: 0.55 ± 0.10, TRF1: 0.26 ± 0.04) (P < 0.05); mRNA expression level (1.45 ± 0.07) and the protein expression level (0.88 ± 0.06) of TRF2 was increased compared to that of BEAS-2B group (mRNA: 1.00 ± 0.07, protein: 0.48 ± 0.06) and DMSO group (mRNA: 1.00 ± 0.06, protein: 0.50 ± 0.06) (P < 0.05). CONCLUSION: The change of gene and protein expression level in POT1, TRF1, and TRF2 involved in the process that evolved into malignant transformation in bronchial epithelial cells BEAS-2B induced by coal tar pitch smoke extracts.

[Change of structural maintenance of chromosome (SMC)1, SMC3, Separase and Securin expression in BEAS-2B malignant transformation cell induced by coal tar pitch smoke extracts].

OBJECTIVE: to study the role of structural maintenance of chromosome (SMC)1, SMC3, Separase and Securin in tumorgenesis that contact with coal tar pitch. METHODS: the BEAS-2B cells was induced by coal tar pitch smoke extracts to form malignant transformation cell model in vitro. The gene expression levels of mRNA were assessed by real-time quantitative RT-PCR, and the protein expression variation were determined by cell culture overslip of immunohistochemical methods. RESULTS: in malignant transformation cells, the mRNA and the protein expression level of SMC1 gene was not statistically significantly different compared with the BEAS-2B group and DMSO group (P > 0.05); SMC3 and Separase was increased and Securin was decreased (P < 0.05), while the difference between other two control groups was not significant (P > 0.05). CONCLUSIONS: the up expression level of SMC3 and Separase and the down expression level of Securin are involved in the process that evolves into malignant transformation in bronchial epithelial cells BEAS-2B induced by coal tar pitch smoke extracts.