Distinct expression of C4.4A in colorectal cancer detected by different antibodies

Hirofumi Yamamoto, Ryota Oshiro, Masahisa Ohtsuka, Mamoru Uemura, Naotsugu Haraguchi, Junichi Nishimura, Ichiro Takemasa, Tsunekazu Mizushima, Yuichiro Doki, Masaki Mori

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)197-201
Number of pages5
JournalInternational journal of oncology
Issue number1
Publication statusPublished - Jan 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Oncology
  • Cancer Research


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