The absolute quantification of eight inter-α-trypsin inhibitor heavy chain 4 (ITIH4)-derived peptides in serum from breast cancer patients.

Purpose: Various studies exploring the potential of the low-molecular-weight serum peptidome have identified proteolytic cleavage products of inter-α-trypsin inhibitor heavy chain-4 (ITIH(4)) as potential markers for different types of cancer, presumably generated by tumor-associated exoproteases. However, further elucidation of the discriminative properties of such peptides requires specific quantitative analytical methods.

Experimental Design: Using a recently developed and fully validated liquid chromatography-tandem mass spectrometric method, we have compared absolute serum concentrations of eight peptides derived from ITIH(4 [658-687]) to ([667-687]) (ITIH(4)-30 to -21) between breast cancer patients (n=45) and controls (n=78).

Serum degradome markers for the detection of breast cancer.

Many proteins have been proposed as potential biomarkers for breast cancer. Yet, validation of their discriminative value using quantitative methods has scarcely been performed. In this study, we investigated the discriminative value of six peptides that were previously proposed to be generated by breast cancer specific exoproteases: bradykinin, des-Arg(9)-bradykinin, Hyp(3)-bradykinin, and fragments of fibrinogen alpha-chain (Fib-alpha ([605-629])), complement component 4a (C4a ([1337-1350])), and interalpha trypsin inhibitor heavy chain 4 (ITIH4 ([666-687])).

Validation of previously identified serum biomarkers for breast cancer with SELDI-TOF MS: a case control study.

Background: Serum protein profiling seems promising for early detection of breast cancer. However, the approach is also criticized, partly because of difficulties in validating discriminatory proteins. This study's aim is to validate three proteins previously reported to be discriminative between breast cancer cases and healthy controls.