Open AccessDecreased expression of 14‐3‐3 σ, an early event of malignant transformation of respiratory epithelium, also facilitates progression of squamous cell lung cancer
Author(s) -
Sun Nan,
Wu Yongkai,
Huang Bo,
Liu Qian,
Dong Yinan,
Ding Jianqiao,
Liu Yongyu
Publication year - 2015
Publication title -
thoracic cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.823
H-Index - 28
eISSN - 1759-7714
pISSN - 1759-7706
DOI - 10.1111/1759-7714.12246
Subject(s) - carcinogenesis , squamous metaplasia , medicine , dysplasia , lung cancer , malignant transformation , pathology , immunohistochemistry , metaplasia , carcinoma in situ , cancer research , tumor progression , cancer , lung , carcinoma , epithelium , cell , cell growth , biology , genetics
Background It has been shown that 14‐3‐3 σ serves as a tumor suppressor gene, and is downregulated in various tumor tissues. However, the role of 14‐3‐3 σ during the initiation and progression of lung squamous cell carcinoma ( SqCC ) is not well understood. Methods The expression status of 14‐3‐3 σ in archival tissue samples from 40 lung SqCC patients (36 with normal bronchia, 19 squamous metaplasia, and 17 dysplasia/carcinoma in situ , in their tissue samples) was examined by immunohistochemical analysis. The proliferation rate and tumor formation ability of the H520 cell transfected with 14‐3‐3 σ was tested with methyl thiazolyl tetrazolium assay and nude mice subcutaneous injection, respectively. Results In the normal bronchial epithelia, 14‐3‐3 σ was highly expressed, whereas it was significantly decreased in precancerous and cancerous tissues. Compared with matched invasive cancer tissues, the expression level of 14‐3‐3 σ in squamous metaplasia was significantly higher ( P = 0.049), while that in dysplasia/carcinoma in situ showed no significant changes ( P = 0.135). Statistical analysis showed that the expression level of 14‐3‐3 σ in tumor tissue was associated with the differentiation grade of the tumor ( P = 0.001) and the prognosis of the patient ( P = 0.003). The overexpression of 14‐3‐3 σ significantly suppressed the proliferation of H520 cells in vitro and in vivo . Conclusion The inactivation of 14‐3‐3 σ may be a very early event in tumorigenesis and could facilitate the initiation and progression of lung SqCC in a sustainable way.