MALDI-based imaging mass spectrometry revealed abnormal distribution of phospholipids in colon cancer liver metastasis.
We present the results of matrix-assisted laser desorption/ionization (MALDI) imaging and direct molecular identification using tandem mass spectrometry (MS/MS) in colon cancer liver metastasis. Cancer tissue was removed from a Japanese patient and frozen immediately without any fixations. The sections were sliced to a thickness of 3 microm. The matrix for lipid ionization was 2,6-dihydroxy acetophenone. The matrix solution was applied with an airbrush into a thin uniform matrix layer on the tissue surface. After two-dimensional laser scanning, the images were reconstructed as a function of m/z from a few hundred obtained spectra. In the obtained images, the existence of molecules was represented by a pseudo-color corresponding to the signal intensity. In a feasibility study, we picked up a localized signal, m/z 725 in a cancerous area. The MS/MS result suggested that m/z 725 was sphingomyelin(16:0)+Na. Thus, we successfully show the feasibility of MALDI imaging as a tool for the analysis of pathological specimens.
Shimma
Shuichi
S
Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Aichi, Japan.
Sugiura
Yuki
Y
Hayasaka
Takahiro
T
Hoshikawa
Yutaka
Y
Noda
Tetsuo
T
Setou
Mitsutoshi
M
D003110:Colonic Neoplasms / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary*; D010743:Phospholipids / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D010743:Phospholipids