Expression Pathology Incorporated

Adele Blackler

Todd Hembrough

David B Krizman

Sheeno Thyparambil

Wei-Li Liao

Fabiola Cecchi

Eunkyung An

Paolo Nuciforo

The current disclosure provides for specific peptides, and derived ionization characteristics of the peptides, from the tyrosine-protein kinase receptor UFO protein (AXL) that are particularly advantageous for quantifying the AXL protein directly in biological samples that have been fixed in formalin by the method of Selected Reaction Monitoring (SRM) mass spectrometry, or what can also be termed as Multiple Reaction Monitoring (MRM) mass spectrometry. Such biological samples are chemically preserved and fixed wherein said biological sample is selected from tissues and cells treated with formaldehyde containing agents/fixatives including formalin-fixed tissue/cells, formalin-fixed/paraffin embedded (FFPE) tissue/cells, FFPE tissue blocks and cells from those blocks, and tissue culture cells that have been formalin fixed and or paraffin embedded. A protein sample is prepared from said biological sample using the Liquid Tissue reagents and protocol and the AXL protein is quantitated in the Liquid Tissue sample by the method of SRM/MRM mass spectrometry by quantitating in the protein sample at least one or more of the peptides described. These peptides can be quantitated if they reside in a modified or an unmodified form. An example of a modified form of an AXL peptide is phosphorylation of a tyrosine, threonine, serine, and/or other amino acid residues within the peptide sequence.

SRM/MRM assay for the tyrosine-protein kinase receptor UFO(AXL) protein

Methods of treating breast cancer are provided where a quantitative Her2 assay is used to identify whether a breast tumor will be responsive to treatment with anti-Her2 therapeutic agents such as lapatinib and trastuzumab, followed by selection of a suitable treatment regimen and administration of the regimen. A specific Her2 fragment peptide is precisely quantitated by SRM-mass spectrometry directly in breast tumor cells collected from breast tumor tissue that was obtained from a cancer patient and compared to a reference level in order to determine if the breast cancer patient will positively respond to treatment with a therapeutic agent that specifically targets the Her2 protein.

Methods for treating Her2-positive breast cancer

Peptides from the tyrosine-protein kinase receptor UFO protein (AXL) are provided that are particularly advantageous for quantifying the AXL protein directly in biological samples that have been fixed in formalin by the method of Selected Reaction Monitoring (SRM)/Multiple Reaction Monitoring (MRM) mass spectrometry. Such biological samples are chemically preserved and fixed and include formalin-fixed tissue/cells, formalin-fixed/paraffin embedded (FFPE) tissue/cells, FFPE tissue blocks and cells from those blocks. A protein digest is prepared from the biological sample and the AXL protein is quantitated in the Liquid Tissue sample by the method of SRM/MRM mass spectrometry by quantitating in the protein sample at least one or more of the peptides described.

SRM/MRM assay for the tyrosine-protein kinase receptor UFO (AXL) protein

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Rockville, MD, United States of America

Adele Blackler