Distinct expression of C4.4A in colorectal cancer detected by different antibodies.
Distinct expression of C4.4A in colorectal cancer detected by different antibodies.
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DOI：
10.3892/ijo.2012.1714
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发表时间：
2013
影响因子：
5.2
通讯作者：
Hirofumi Yamamoto;Ryota Oshiro;Masahisa Ohtsuka;M. Uemura;N. Haraguchi;J. Nishimura;I. Takemasa;T. Mizushima;Y. Doki;M. Mori
中科院分区：
文献类型：
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作者：
Hirofumi Yamamoto;Ryota Oshiro;Masahisa Ohtsuka;M. Uemura;N. Haraguchi;J. Nishimura;I. Takemasa;T. Mizushima;Y. Doki;M. Mori
转移相关基因C4.4A编码糖脂锚定膜蛋白，在几种人类恶性肿瘤中表达。本研究旨在从细胞内定位、肿瘤内定位和分子量差异方面对结直肠癌组织中C4.4A的表达进行详细评估。为了推进这一目标，我们开发了三种新的抗C4.4A蛋白的抗体（两种多克隆抗体：C4.4A-119和C4.4A-277和一种单克隆抗体：C4.4A GPI-M），除了两种以前生产的多克隆抗体（C4.4A-81，C4.4A GPI-P）之外，还使用。通过吸收试验证实了抗体特异性。蛋白质印迹分析和免疫组织化学显示，C4.4A-119和C4.4-277 Abs检测到70-kDa C4.4A，主要在细胞质中，无论肿瘤内位置如何。C4.4A GPI-P和C4.4A GPI-M Ab仅在肿瘤浸润前沿与膜性~40-kDa C4.4A反应，并且各自检测到相同的肿瘤细胞群。所测试的抗体在33个CRC组织中显示不同的C4.4A检测率。C4.4A-277抗体在33例结直肠癌组织中的阳性率最高（87.9%），而C4.4A GPI-P和C4.4A GPI-M抗体的阳性率分别为33.3%。目前的研究结果表明，GPI锚信号序列可能是必不可少的检测膜C4.4A在大肠癌组织的浸润前沿。
The metastasis-associated gene C4.4A encodes a glycolipid-anchored membrane protein expressed in several human malignancies. The present study aimed to perform a detailed assessment of C4.4A expression in colorectal cancer tissues, in terms of intra-cellular localization, intra-tumoral location and difference in molecular weight. To advance this goal, we developed three new antibodies against the C4.4A protein (two polyclonal Abs: C4.4A-119 and C4.4A-277 and one monoclonal Ab: C4.4A GPI-M) to use in addition to the two previously produced polyclonal Abs (C4.4A-81, C4.4A GPI-P). Antibody specificities were confirmed by absorption tests. Western blot analysis and immunohistochemistry showed that the C4.4A-119 and C4.4-277 Abs detected 70-kDa C4.4A, mainly in the cytoplasm, irrespective of intra-tumoral location. The C4.4A GPI-P and C4.4A GPI-M Abs reacted with the membranous ~40-kDa C4.4A, exclusively at the tumor invasive front, and each detected an identical tumor cell population. The tested antibodies showed varied C4.4A detection rates in 33 CRC tissues. The C4.4A-277 Ab yielded the highest positive rate in 29 of 33 CRC tissues (87.9%), while the C4.4A GPI-P and C4.4A GPI-M Abs each only showed 33.3% positivity. The present findings suggest that the GPI anchor signaling sequence may be essential for detecting membranous C4.4A at the invasive front of CRC tissues.