Expression of fragile histidine triad (FHIT) protein and Ki-67 in transformed epithelial cells induced by Yunnan tin mine dust / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the expression and significance of fragile histidine triad (FHIT) and Ki-67 in transformed epithelial cells induced by Yunnan tin mine dust.</p><p><b>METHODS</b>Every second generation of immortalized human bronchial epithelial cells (BEAS-2B) and human embryo lung fibroblasts (WI-38) were exposed to 100 µg/ml Yunnan tin mine dust for 72 h, until the ninth generation. The cells were subsequently co-cultured from the 11th generation. Experimental setup: B group, B (W) group, B (W 100) group, B100 group, B100 (W) group, B100 (W100) group. The expressions of FHIT and Ki-67 in epithelial cells were determined by the method of immunocytochemistry at the 16th, 26th and 36th generation. The percentage of Ki-67 positive cells was calculated as proliferation index.</p><p><b>RESULTS</b>The expression of FHIT was observed in BEAS-2B cells. The expression levels of FHIT among B group, B (W) group and B (W 100) group had not instinctive difference. At the 16th generation, the expression of FHIT in the B100 group was decreased compared with that in the B group and the expression of FHIT between B100 (W) group and B100 (W100) group was lower than that in the B100 group. At the 26th generation, the expression of FHIT was decreased compared with that at the 16th generation in the B100, B100 (W) and B100 (W100) groups. However, At the 36th generation, positive expression were observed again in the B100, B100 (W) and B100 (W100) groups and the expression levels were in incremental order. At the 16th, 26th and 36th generation, the proliferation indexes of B group, B (W) group and B (W 100) group were all < 3%. The proliferation indexes of B100, B100 (W) and B100 (W100) were increased step by step with the generation elongation.</p><p><b>CONCLUSIONS</b>FHIT could be a target at which Yunnan tin mine dust induces transformation of BEAS-2B cells. The proliferation activation of BEAS-2B cells can be improved by Yunnan tin mine dust.</p>

Expression of hTERT and Mad1 in lung cancer in Gejiu and Xuanwei of Yunnan Province / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the expression of hTERT mRNA and Mad1 protein in lung cancer of Gejiu and Xuanwei and normal lung tissue and to investigate their correlations with lung cancer.</p><p><b>METHODS</b>Mad1 protein was detected by immunohistochemistry S-P method, and hTERT message RNA (mRNA) was detected by in situ hybridization (ISH) in 40 specimens of lung cancer of Gejiu Tin miners and 20 specimens of lung cancer of Xuanwei peasants and 20 specimens of normal lung tissue. The positive signals were quantitatively analyzed by HPIAS-100.</p><p><b>RESULTS</b>The positive unit (PU) of Mad1 protein was 16.77 +/- 6.01 in Gejiu Tin Miners lung cancer group, and 19.36 +/- 4.54 in Xuanwei peasant lung cancer group, compared with the normal lung tissue (46.05 +/- 7.26). The difference was highly significant (P < 0.01); The PU of hTERT mRNA was 72.10 +/- 13.07 in Gejiu Tin miners lung cancer group, and 74.20 +/- 15.17 in Xuanwei peasant lung cancer group, which was higher than that in normal tissue group (10.70 +/- 2.21). The difference was significant (P < 0.01). The expression of Mad1 protein was negatively correlated with the expression hTERT mRNA (P < 0.05, r = 0.9881, r = -0.999).</p><p><b>CONCLUSION</b>Reduced hTERT mRNA expression may play an important role in the occurrence of lung cancer. The expression of hTERT mRNA and deletion of Mad1 protein are closely related to pathogenesis of lung cancer.</p>

Interaction between malignant transformation of human pulmonary epithelial cells and activation of fibroblasts induced by Yunnan tin mine dust / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the interaction between transformation of human pulmonary epithelial cells and activation of fibroblasts induced by Yunnan tin mine dust.</p><p><b>METHODS</b>(1) The immortalized human bronchial epithelial cell line BEAS-2B and human embryo lung fibroblast cell line WI-38 were grown in MEM medium containing 5% and 10% FBS, respectively, at 37 degrees C and 5% CO2 with saturated humidity. The cells were subcultured every 6 days. BEAS-2B cells and WI-38 cells were induced with Yunnan tin mine dust on every other generation at the concentration of 100 microg/ml. From the 11th generation, the cells were co-cultured. Epithelial cell transformation was tested using concanavalin A (ConA) agglutination and anchorage-independent growth assays. The cell cycles were analyzed through flow cytometry. The expressions of alpha-SMA in fibroblasts were determined with immunocytochemistry.</p><p><b>RESULTS</b>(1) Cell morphology of mine dust-exposed epithelial cells began to transform at the 28th generation. Similar transformations were observed with mine dust-induced epithelial cells co-cultured with fibroblasts from the 20th generation and mine dust-induce epithelial cells co-cultured with mine dust-induced fibroblasts from the 16th generation. ConA agglutination assay and anchorage-independent growth assays were negative in normal BEAS-2B cells. At the 26 th generation, the agglutination test result of the mine dust-exposed epithelial cells was positive. Co-cultured with fibroblasts and mine dust-exposed fibroblasts, the agglutination time of the mine dust-exposed epithelial cells became short. Epithelial cell anchorage-independent growth assay was positive for mine dust-exposed epithelial cells co-cultured with fibroblasts at the 36th generations and for mine dust-exposed epithelial cells co-cultured with mine dust-exposed fibroblasts at the 26th generations. The clone formation rate of the 26th generation was 6.00 per thousand +/- 1.00 per thousand and 15.33 per thousand +/- 2.52 per thousand respectively, with the significant differences (P < 0.05). With generation adding, the portion of S phase increased for mine dust-exposed epithelial cells. (2) At the 26th generations, fibroblasts expressed alpha-SMA. Co-cultured with epithelial cell, the alpha-SMA expression of fibroblasts increased. Especially, positive cell numbers and intensity of staining dramatically increased with generation adding.</p><p><b>CONCLUSIONS</b>(1) The tin mine dust can induce malignant transformation of human pulmonary epithelial cells BEAS-2B and activation of fibroblasts WI-38. (2) The epithelial cells are major target in carcinogenesis induced by Yunnan tin mine dust. (3) Transformation of epithelia and activation of fibroblasts co-evolve in the developing process of induced lung cancer by Yunnan tin mine dust.</p>

Expression of p14(ARF) and E2F-1 in lung cancer in Gejiu and Xuanwei regions of Yunnan Province / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the correlations between p14(ARF) and E2F-1, and the role of their alterations in the tumorigenesis of the lung cancer in Gejiu and Xuanwei regions in Yunnan Province for providing the important experiment basis in revealing the molecular mechanism and looking for new markers for early diagnosis of lung cancer.</p><p><b>METHODS</b>The expression of p14(ARF) and E2F-1 was detected at theirs protein level by Immunohistochemistry S-P method in 30 specimens of lung cancer of Gejiu tin miners, 30 specimens of lung cancer of Xuanwei peasants and 20 specimens of normal lung tissue. E2F-1 mRNA was detected by ISH in 25 specimens of lung cancer of Gejiu tin miners, 25 specimens of lung cancer of Xuanwei peasants and 10 specimens of normal lung tissue. The positive signals were quantitatively analysed by HPIAS-100.</p><p><b>RESULTS</b>The positive unit (PU) of p14(ARF) and E2F-1 was 16.44 +/- 4.85 and 47.39 +/- 5.43 in Gejiu group, and 16.79 +/- 3.55 and 48.15 +/- 9.11 in Xuanwei group. Expression of p14(ARF) and E2F-1 protein in lung cancer of Gejiu and Xuanwei were statistically different compared with that in the normal lung (P < 0.01) respectively; The PU of E2F-1 mRNA was 48.58 +/- 7.75 in Gejiu group, and 49.41 +/- 8.53 in Xuanwei group, which was higher than that in normal tissue group. The differences were significant (P < 0.01). There was positive correlation between the expression of E2F-1 protein and E2F-1 mRNA in Gejiu group, Xuanwei group and normal group (P < 0.01, r = 0.833). The expression of p14(ARF) protein was significantly negatively correlated with the expression of E2F-1 protein (P < 0.01, r = -0.830).</p><p><b>CONCLUSION</b>There is the over-expression of E2F-1 gene and the deletion of p14(ARF) gene in the tumorigenesis of the lung cancer in Gejiu and Xuanwei regions in Yunnan Province. Over-expression of E2F-1 protein in lung cancer may be caused by enhanced transcription.</p>

Pathological study of lung cancer induced by Yunnan tin mine dusts in F344 rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To set up animal models of the lung cancer induced by Yunnan tin mineral dusts (no radon) in F344 rats and to explore the process of carcinogenesis and pathologic alterations in various stages of malignant transformation in the animal models.</p><p><b>METHODS</b>One hundred and ninety F344 rats were randomly divided into Yunnan tin mineral dust group (100 rats), furfural physiological saline group (30 rats), physiological saline group (30 rats) and normal control group (30 rats). The intratracheal instillation with mass fraction of 6% suspension liquid mixture Yunnan tin mineral dusts, volume fraction of 2% furfural physiological saline and physiological saline 0.2 ml was performed in the rates once per week respectively except normal control group. Then the rats were sacrificed in batch periodically after one week. The last rat was exposed to the tin mine dusts for 100 weeks. The morphological process and tumor formation were dynamically observed under LM and TEM. Immunohistochemistry detection of cytokeratin of High MW and low MW was used for tumor classification. Pollak stein was used to evaluate the development of fibrosis of lung in the rats.</p><p><b>RESULTS</b>Bronchoalveolar inflammation occurred in the early stage after the intratracheal instillation of Yunnan tin mineral dust was performed in F344 rates. Along with reduction of inflammation, collagen fibrils increased at alveolar interstices. Simple hyperplasia, papillary hyperplasia and metaplasia of the epithelial cells in alveolar and bronchi were observed, followed by atypical adenomatous hyperplasia and squamous dysplasia. Lung cancer was induced in the end. Among the 14 cases of lung cancer, 9 cases were adenocarcinoma, 2 squamous cell carcinoma and 3 mixed carcinoma. No lung cancer occurred in other three control groups. There was a significant difference in the malignancy rate between the experimental group and the three control groups (P < 0.01). The squamous metaplasia and squamous carcinoma were found in alveoli that expressed cytokeratin of High MW. Lung fibrosis was found in 31 cases of in the tin mineral dust group. The greater the mineral dust deposit was, the more serious the alveolar fibrosis was.</p><p><b>CONCLUSION</b>Yunnan tin mineral dusts without radon induce lung cancer in rates. The adenocarcinoma and squamous carcinomas induced in F344 rat lung can occur in the alveoli. The further study on whether type II alveolar epithelial cells are the origin cells of adenocarcinoma and some peripheral squamous lung carcinomas is worthwhile.</p>