Quantitative proteomics data using mTRAQ/MRM looking at human AKR family members in cancer cell lines

Members of the human aldo-keto reductaseAKRsuperfamily have been reported to be involved in cancer progression, and to investigate their role further a quantitative method to measure human AKR proteins in cells using mTRAQ-based multiple reaction monitoring (MRM) has been developed. AKR peptides with multiple transitions were carefully selected upon tryptic digestion of the recombinant AKR proteins, while AKR proteins were identified by SDS-PAGE fractionation coupled with LC MS/MS. Utilizing mTRAQ triplex labeling to produce the derivative peptides, calibration curves were generated using the mixed lysate as background, and no significantly different quantification of AKRs was elicited from the two sets of calibration curves under the mixed and single lysate as background. This approach was employed to quantitatively determine the 6 AKR proteins, AKR1A1, AKR1B1, AKR1B10, AKR1C1/C2, AKR1C3 and AKR1C4 in 7 different cancer cell lines, and for the first time to obtain the absolute quantities of all the AKR proteins in each cell. The cluster plot revealed that AKR1A and AKR1B were widely distributed in most cancer cells with relatively stable abundances, whereas AKR1Cs were unevenly detected among cells demonstrating diverse dynamic abundances. The AKR quantitative distribution in different cancer cells, and may enable further insight on the role of AKR proteins are involved in tumorigenesis.