Oncology Pathology, Department of Pathology and Host-Defence, Faculty of Medicine, Kagawa University, Kagawa, 761-0793, Japan.
Kaisei General Hospital, Kagawa, 762-0007, Japan.
Sci Rep. 2020 Apr 20;10(1):6647. doi: 10.1038/s41598-020-63667-4.
Crystalline silica (quartz) is known to induce silicosis and cancer in the lungs. In the present study, we investigated the relationship between quartz-induced chronic inflammation and lung carcinogenesis in rat lungs after a single exposure to quartz. F344 rats were treated with a single intratracheal instillation (i.t.) of quartz (4 mg/rat), and control rats were treated with a single i.t. of saline. After 52 or 96 weeks, the animals were sacrificed, and the lungs and other organs were used for analyses. Quartz particles were observed in the lungs of all quartz-treated rats. According to our scoring system, the lungs of rats treated with quartz had higher scores for infiltration of lymphocytes, macrophages and neutrophils, oedema, fibrosis, and granuloma than the lungs of control rats. After 96 weeks, the quartz-treated rats had higher incidences of adenoma (85.7%) and adenocarcinoma (81.0%) than control rats (20% and 20%, respectively). Quartz-treated and control rats did not show lung neoplastic lesions at 52 weeks after treatment. The number of lung neoplastic lesions per rat positively correlated with the degree of macrophage and lymphocyte infiltration, oedema, fibrosis, and lymph follicle formation around the bronchioles. In conclusion, single i.t. of quartz may induce lung cancer in rat along with chronic inflammation.
结晶二氧化硅（石英）已知可引起矽肺和肺癌。在本研究中，我们研究了大鼠单次气管内注入石英后慢性炎症与肺癌发生之间的关系。F344 大鼠经单次气管内滴注（i.t.）石英（4mg/大鼠）处理，对照组大鼠经单次 i.t.生理盐水处理。52 或 96 周后，处死动物，取肺及其他器官进行分析。所有接受石英处理的大鼠的肺中均观察到石英颗粒。根据我们的评分系统，与对照组大鼠相比，接受石英处理的大鼠的肺中淋巴细胞、巨噬细胞和中性粒细胞浸润、水肿、纤维化和肉芽肿的评分更高。96 周后，与对照组（分别为 20%和 20%）相比，石英处理组大鼠的腺瘤（85.7%）和腺癌（81.0%）发生率更高。处理后 52 周，石英处理组和对照组大鼠均未出现肺肿瘤病变。每只大鼠的肺肿瘤病变数与巨噬细胞和淋巴细胞浸润、水肿、纤维化以及细支气管周围淋巴滤泡形成的程度呈正相关。总之，单次气管内注入石英可能会导致大鼠发生肺癌，并伴有慢性炎症。
