A cancer-related protein 14-3-3ζ is a potential tumor-associated antigen in immunodiagnosis of hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. Serum alpha-fetoprotein (AFP) is the conventional biomarker currently used in clinical diagnosis of this malignancy. However, AFP is not reliable for early diagnosis, and especially the sensitivity and specificity of AFP in HCC diagnosis are not optimal. Early detection of HCC is an important issue because of the very poor prognosis and usually no more than 6 months survival after diagnosis. Therefore, there is a need for the development of more sensitive and specific methods that can supplement AFP in the early detection of this cancer. In this study, autoantibody responses to 14-3-3ζ in HCC were evaluated by enzyme-linked immunosorbent assay (ELISA), western blot, and indirect immunofluorescence assay. Immunohistochemistry (IHC) with tissue array slides was also performed to analyze protein expression of 14-3-3ζ in HCC and control tissues. The prevalence of autoantibodies against 14-3-3ζ was 16.7 % (28/168) in HCC, which was significantly higher than that in liver cirrhosis (LC), chronic hepatitis (CH), and normal human sera (NHS) (P<0.01). The average titer of autoantibodies against 14-3-3ζ in HCC sera was higher compared to that in LC, CH, and NHS (P<0.01). In the further study, anti-14-3-3ζ antibodies have been detected in the sera from several HCC patients with serial bleeding samples. A stronger reactive band with 14-3-3ζ in western blot can be seen in sera at 9 months before the clinical diagnosis of HCC. Our preliminary data indicate that anti-14-3-3ζ autoantibodies may be potential biomarkers for early-stage HCC screening and diagnosis.

Tumor-associated autoantibodies are useful biomarkers in immunodiagnosis of α-fetoprotein-negative hepatocellular carcinoma

“…Our previous studies[8,14,19] have shown that the levels of NPM1, anti-14-3-3zeta and anti-MDM2 autoantibodies were all significantly higher in the HCC patient sera, with a 16.7%-22.4% positive rate, which was confirmed in the present study. In addition, we specifically evaluated the diagnostic value of three TAA autoantibodies and their different combinations in immunodiagnosis of AFP-negative HCC.…”

Early detection of hepatocellular carcinoma using autoantibody profiles from a panel of tumor-associated antigens

“…The sources of the 12 genes' cDNA clones were described in detail in a previous study [7]. cDNAs of HCC1, IMP1, Koc, MDM2, NPM1, p53, p62, survivin, RalA, survivin, and 14-3-3 ζ genes were subcloned into pET28a vector producing a fusion protein with NH-terminal 6× histidine and T7 epitope tags [8-14]. The recombinant proteins expressed in Escherichia coli BL21 (DE3) were purified using nickel column chromatography.…”

14-3-3zeta positive cells show more tumorigenic characters in human glioblastoma

“…They should be treated differently by special molecular status for a good outcome, such as HeR-2 positive expression in human breast cancer with Herceptin chemotherapy (27) and MGMT inactivation in human glioblastoma with TMZ therapy (11). 14-3-3zeta expression is upregulated in various types of malignancies, including prostate cancer, breast cancer, lung carcinoma and hepatocellular carcinoma (15,17,18,20). A high cell percentage of 14-3-3zeta positive expression was found in these tumor tissues, especially in human glioblastoma tissue (30).…”

“…There are some possible potential molecular pathways. A previous study shows that 14-3-3zeta affects many tumorigenic pathways and factors, including erbB2, miR221, Hsp27, Wnt, STAT3 and PI3K pathways, during tumor onset, cell proliferation, progression and malignant transformation (7, 13,17,18,22,26,31,32). Knockdown of 14-3-3zeta enhanced chemosensitivity and radiosensitivity in several types of tumor, including CD133+ cancer stem cells (6,12,14).…”