A simple method for sphingolipid analysis of tissues embedded in optimal cutting temperature compound.

Area of Science:

• Biochemistry
• Molecular Biology
• Pathology

Background:

• Mass spectrometry (MS)-assisted lipidomic tissue analysis is crucial for understanding sphingolipid metabolism in disease.
• Biorepositories offer valuable human tissue resources, but cryopreservation media like OCT compound hinder MS analysis.
• OCT compound interferes with protein quantification and sphingolipid measurements.

Purpose of the Study:

• To develop and validate a method for removing OCT compound from cryopreserved tissues for lipidomic analysis.
• To assess the impact of OCT compound removal on sphingolipid quantification accuracy.
• To analyze sphingolipid alterations in lung cancer and determine long-term sphingolipid stability in cryopreserved tissues.

Main Methods:

• Development and validation of a simple, inexpensive protocol to remove OCT compound from embedded tissues.
• Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for sphingolipid quantification.
• Comparative analysis of sphingolipids in lung tumors versus adjacent normal lung tissues.
• Assessment of sphingolipid stability in OCT compound-cryopreserved normal lung tissues over time.

Main Results:

• The developed method effectively removes OCT compound without significantly affecting sphingolipid measurement accuracy.
• Lung cancer tumors exhibit significantly altered sphingolipid profiles compared to normal lung tissues.
• Sphingolipids remain stable for up to 16 years in OCT compound-cryopreserved normal lung tissues.

Conclusions:

• A validated OCT compound removal protocol enhances the utility of biorepository tissues for sphingolipidomic studies.
• This method facilitates the investigation of sphingolipid metabolism in diseases like lung cancer.
• Sphingolipids are stable in cryopreserved tissues, supporting retrospective clinical studies.