Protein assay analysis of colorectal cancer

Protein microarray screening

We performed the screening using the ProtoArray v5.1 human protein microarray system (Thermo Fisher Scientific, Waltham, MA), which comprises 9375 protein species. We employed Alexa Fluor 647-anti-human IgG detection reagent to quantify the serum IgG bound to immobilized proteins and made pairwise comparisons between the 2 sample populations. The algorithm to select candidate antigens in our study determined that the antigen positivity rate in the sera of patients with CRC was more than 60%, and the positivity rate in the sera of HDs was less than 20% as described [1, 2].

Ref. 1.  Naito A, Hiwasa T, Tanabe N, Sanada TJ, Sugiura T, Shigeta A, Terada J, Takizawa H, Kashiwado K, Sakao S, et al. Elevated levels of autoantibodies against EXD2 and PHAX in the sera of patients with chronic thromboembolic pulmonary hypertension. PLoS One. 2019;14:e0211377. PMID: 30759165

Ref. 2. Hiwasa T, Wang H, Goto K, Mine S, Machida T, Kobayashi E, Yoshida Y, Adachi A, Matsutani T, Sata M, et al. Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke. BMC Medicine. 2021;19:131. doi:10.1186/s12916-021-02001-9. PMID:34103026