Abstract Hepatocellular carcinoma (HCC) is one of the most lethal cancers for humans. Early diagnosis of HCC can significantly enhance the treatment outcomes and reduce disease mortality. MAN2A1-FER is one of the most frequent oncogenic fusion genes in HCC. Our previous studies showed that MAN2A1-FER ectopically phosphorylated the extracellular domain of PDGFRA. The present study aimed to examine the diagnostic utility of antibodies specific for the ectopically phosphorylated PDGFRA generated by MAN2A1-FER in HCC patients’ serum samples. In this study, 130 serum samples from HCC (65) patients and non-HCC (65) patients were analyzed. Our results showed that the antibody levels specific for the ectopically phosphorylated PDGFRA were 3.5- to 10-fold elevated in the serum samples from HCC patients in comparison with individuals without liver cancers and negative for MAN2A1-FER gene fusion. The higher titers of anti-ectopic-pPDGFRA-N-terminus in the serum samples correlated with the HCC diagnosis and outperformed the serum alpha-fetal protein for the diagnosis of HCC. The presence of these antibodies was also highly correlated with the levels of MAN2A1-FER mRNA in these serum samples. We concluded that the elevated serum levels of anti-pPDGFRA-N-terminus antibodies are highly predictive of liver cancer and can be utilized as a potential diagnostic marker for HCC. Citation Format: Jian-Hua Luo, Muhamuda Kader, Yan-Ping Yu. Detection of ectopic phosphorylated PDGFRA antibodies in the serum samples of HCC patients abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6340.
Luo et al. (Fri,) studied this question.