67th Annual Meeting Abstracts

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MALDI Mass Spectrometry Tissue Imaging and Clinical Applications for Renal Cell Carcinoma
*David Staneck, *Lisa Cazares, *Dean Troyer, *Richard Drake, *Stephen Riggs
Eastern Virginia School of Medicine, Norfolk, VA

Introduction:
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a novel tool for investigating tumor biology as it allows analysis of protein distribution directly from intact tissue sections. We report a pilot study evaluating MALDI MSI in clear cell renal cell carcinoma (cRCC) and papillary renal cell carcinoma (pRCC).
Materials & Methods:
Frozen tissue from surgical specimens of pathologically confirmed cRCC and pRCC were used for analysis. Adjacent tissue sections were prepared for IHC analysis and MALDI MSI from 10 specimens of cRCC and pRCC. 5 specimens of normal renal parenchyma were used as a control. A Bruker Daltonics Ultraflex III MALDI time of flight (TOF) system was used to generate spectra from the 3 tissue groups . Differences in protein expression were determined using FlexImaging software.
Results:
Significant differences in spectra obtained from the 3 groups. For cRCC the spectra revealed high intensity protein peaks at 4632.23 m/z (mass to charge ratio) and 9261.06 m/z that were less in the spectra for pRCC and normal renal parenchyma. Unique to pRCC and cRCC was a peak at 3443.55 m/z which was significantly more intense in pRCC compared to cRCC. This was not seen in the spectra for normal renal parenchyma.
Conclusions:
We report the novel use of MALDI MSI as a potential adjunct to pathologic examination of RCC. Clear differences in protein expression were seen between cRCC and pRCC. Future evaluation of this technology will focus on all RCC histologic subtypes and itspotential application to percutaneous renal biopsies.

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