AHNAK is highly expressed and plays a key role in cell migration and invasion in mesothelioma

Int J Oncol. 2014 Feb;44(2):530-8. doi: 10.3892/ijo.2013.2183. Epub 2013 Nov 20.

Abstract

The worldwide incidence of the highly aggressive tumor mesothelioma is expected to increase. Mesothelioma is classified into three main histological subtypes: epithelioid, sarcomatoid and biphasic. Although the pathological diagnostic markers for epithelioid are established, to date no adequate marker for sarcomatoid mesothelioma has been found. Thus, a reliable diagnostic marker of sarcomatoid mesothelioma is necessary. In this study, to identify an unknown protein with 120 kDa expressed only in the mesothelioma cell line 211H, we conducted proteomic analysis and found five candidate proteins. One such protein, AHNAK, was highly expressed in all seven mesothelioma cell lines (211H, H28, H226, H2052, H2452, MESO1 and MESO4), but not in the mesothelial cell line MeT-5A by RT-PCR and immunofluorescence staining. Furthermore, we confirmed high AHNAK expression not only in xenografts but also in human mesothelioma specimens including sarcomatoid, epithelioid and biphasic mesothelioma using immunohistochemical staining. These findings suggest that AHNAK has the potential to be a new marker for detecting mesothelioma. Since AHNAK is involved in cell migration and invasion in other metastatic tumor cells, we conducted migration and invasion assays in mesothelioma cell lines. The number of migrating cells in six of seven mesothelioma cell lines and the number of invading cells in all seven cell lines were significantly increased compared with those in MeT-5A. Knockdown of AHNAK significantly reduced the cell migration and invasion ability in all seven mesothelioma cell lines. These results support further clinical evaluation of the association of AHNAK and metastasis in mesothelioma.

MeSH terms

  • Animals
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Blotting, Western
  • Cell Movement*
  • Cell Proliferation
  • Female
  • Fluorescent Antibody Technique
  • Humans
  • Immunoenzyme Techniques
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology*
  • Membrane Proteins / antagonists & inhibitors
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mesothelioma / genetics
  • Mesothelioma / metabolism
  • Mesothelioma / pathology*
  • Mesothelioma, Malignant
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasm Invasiveness
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Pleural Neoplasms / genetics
  • Pleural Neoplasms / metabolism
  • Pleural Neoplasms / pathology*
  • Proteomics
  • RNA, Messenger / genetics
  • RNA, Small Interfering / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • AHNAK protein, human
  • Biomarkers, Tumor
  • Membrane Proteins
  • Neoplasm Proteins
  • RNA, Messenger
  • RNA, Small Interfering