Fujita J, Ohtsuki Y, Bandoh S, Ueda Y, Kubo A, Tojo Y, Yamaji Y, Ishida T
First Department of Internal Medicine, Kagawa Medical University, 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, Japan.
Lung Cancer. 2003 Jan;39(1):31-6. doi: 10.1016/s0169-5002(02)00390-2.
It has been suggested that thyroid transcription factor-1 (TTF-1) is frequently expressed in human lung cancer, especially in adenocarcinoma and small cell lung cancer, and the TTF-1 expression is closely related with the expression of surfactant protein. We hypothesized that TTF-1 is expressed in human lung cancer cell lines and its expression might be related to the expression of surfactant protein. To test this, expressions of TTF-1 and surfactant protein A (SP-A) were immunohistochemically evaluated in 16 human lung cancer cell lines. In addition, expressions of mRNAs for TTF-1 and SP-A were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and sequencing. As a result, nuclear staining of TTF-1 was observed in two of six adenocarcinoma cell lines, none of seven small cell lung cancer cell lines, and none of three squamous lung cancer cell lines. Among the 16 cell lines, six cell lines (PC3, LC2/Ad, A549, RERF-LC-OK, HI1017, and PC9) expressed significant amounts of mRNA for TTF-1. In contrast, cytoplasmic staining of TTF-1 was observed in five of six adenocarcinoma cell lines, in six of seven small cell lung cancer cell lines, and in all three squamous cell lung cancer cell lines. One of the two adenocarcinoma cell lines those showed positive nuclear staining and cytoplasmic SP-A staining released a significant amount of SP-A in culture supernatant. Our present study demonstrates that the frequency of TTF-1 expression in the nucleus was very low in human lung cancer cell lines; however, their cytoplasmic positivities should be further investigated.
有人提出，甲状腺转录因子-1（TTF-1）在人类肺癌中经常表达，尤其是在腺癌和小细胞肺癌中，并且TTF-1的表达与表面活性物质蛋白的表达密切相关。我们推测TTF-1在人类肺癌细胞系中表达，其表达可能与表面活性物质蛋白的表达有关。为了验证这一点，我们采用免疫组织化学方法评估了16种人类肺癌细胞系中TTF-1和表面活性物质蛋白A（SP-A）的表达。此外，通过逆转录聚合酶链反应（RT-PCR）和测序分析了TTF-1和SP-A的mRNA表达。结果显示，在6种腺癌细胞系中有2种观察到TTF-1的核染色，7种小细胞肺癌细胞系中均未观察到，3种肺鳞癌细胞系中也均未观察到。在这16种细胞系中，有6种细胞系（PC3、LC2/Ad、A549、RERF-LC-OK、HI1017和PC9）表达大量的TTF-1 mRNA。相比之下，在6种腺癌细胞系中有5种观察到TTF-1的胞质染色，7种小细胞肺癌细胞系中有6种观察到，3种肺鳞癌细胞系中均观察到。在显示核染色阳性且胞质SP-A染色阳性的2种腺癌细胞系中，有1种在培养上清液中释放了大量的SP-A。我们目前的研究表明，在人类肺癌细胞系中，TTF-1在细胞核中的表达频率非常低；然而，其胞质阳性情况仍需进一步研究。
