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. Author manuscript; available in PMC: 2018 Jun 12.
Published in final edited form as: Proteomics. 2017 Mar;17(6):10.1002/pmic.201600335. doi: 10.1002/pmic.201600335

Figure 3. LC-SRM Assay Implementation in Breast Tumors.

Figure 3

IP-LC-SRM quantification of ER expression (A) and PR expression (B) in tumor tissues and the positive control, MCF7 cells, indicates separation between the ER+ and ER− patients with the exception of 9306, which had low cellularity (see Figure 2E). The dotted line indicates a cutoff value of 10 fmol/mg, which can be used for molecular classification. SDS-PAGE-LC-SRM HER2 expression measurements (C) in another set of tumor tissues and the BT474 positive control also indicate the ability to differentiate between groups using a cutoff value of 500 fmol/mg total protein for molecular classification, with the exception of sample 9423, which had a high degree of blood infiltration (see Figure 2E). Both ER and HER2 cutoffs are based on existing clinical values for intact protein measurements. Clinical calls based on IHC and FISH have been added to the bottom of panels B and C to indicate the status for the biomarkers not assessed by LC-SRM in these samples using the following designations: positive (P), negative (N), no data (ND), and equivocal (EQ).