Highly Sensitive Detection of HER2 Extracellular Domain in the Serum of Breast Cancer Patients by Piezoelectric Microcantilevers

Abstract

Rapid and sensitive detection of serum tumor biomarkers are needed to monitor cancer patients for disease progression. Highly sensitive piezoelectric microcantilever sensors (PEMS) offer an attractive tool for biomarker detection, however their utility in the complex environment encountered in serum has yet to be determined. As a proof of concept, we have functionalized PEMS with antibodies that specifically bind to HER2, a biomarker (antigen) that is commonly overexpressed in the blood of breast cancer patients. The function and sensitivity of these anti-HER2 PEMS biosensors was initially assessed using recombinant HER2 spiked into human serum. Their ability to detect native HER2 present in the serum of breast cancer patients was then determined. We have found that the anti-HER2 PEMS were able to accurately detect both recombinant and naturally occurring HER2 at clinically relevant levels (>2 ng/ml). This indicates that PEMS-based biosensors provide a potentially effective tool for biomarker detection.

Label-free Her2 detection and dissociation constant assessment in diluted human serum using a longitudinal extension mode of a piezoelectric microcantilever sensor

“…Therefore, the time average of the resonance frequency shifts over the period t = 50 - 60 min at each concentration was obtained to approximate the “equilibrium” resonance frequency shifts, Δf. This method for calculating Δf was described in a previous publication [36]. The obtained Δf were -2200±53, -1082±54, -528±38, -194±42, and -28±15 Hz for 60,000, 6,000, 600, 60, and 6 ng/ml of Her2 in diluted serum, respectively.…”

Challenges in the clinical utility of the serum test for HER2 ECD

“…Detection limit, however, is still an issue and highlights the need for ultrasensitive immunological tests. Loo et al developed a piezoelectric microcantilever sensors (PEMS) with 5 fold higher sensitivity than ELISA and was able to detect HER2 ECD in serum at concentrations below the low end of normal range (2 ng/ml)[79]. A new assay based on linear RNA amplification termed Fluorescent Amplification Catalyzed by T7 RNA polymerase Technology (FACTT) reported even higher sensitivities [80].…”

Advances in membrane proteomics and cancer biomarker discovery: Current status and future perspective

“…The studies have shown that it is overexpressed in approximately 30% of breast cancers, and its presence is associated with a poor prognosis . Recently, it has also been reported that the glycosylated peptides from HER2 have been detected in the serum of breast cancer patients and could be used as promising therapeutic target . PGRMC1 is another important biomarker for breast cancer progression.…”