Glypican-3, heat shock protein 70, and glutamine synthetase (GS) are markers currently used, as a single panel, to discriminate the nature of a <2 cm hepatocellular lesion lacking radiological features of hepatocellular carcinoma (HCC) detected in a cirrhotic patient under surveillance.
Glypican-3 (GPC3) is a promising new marker for hepatocellular carcinoma, but the reported values for serum GPC3 differ markedly between currently available kits.
GPC3 (glypican-3) is an emerging target for HCC, given the findings that 1) GPC3 is highly expressed in more than 70% of HCC; (2) elevated GPC3 expression is linked with poor HCC prognosis; and (3) GPC3-specific therapeutics, including immunotoxin, bispecific antibody and chimeric antigen receptor T cells. have shown promising results.
A new re-anchored protein GPC3+afp-EGFP expressed by recombinant pGPC3+afp-EGFP was localized on the cytoplasmic membrane, and had multiple functions against HCC, such as inhibition of transfected HepG2 cell proliferation, promotion of transfected HepG2 apoptosis and induction of antitumor cytokine excretion.
A second experiment conducted to compare macrophage infiltration between the xenograft tissues of a GPC3-transfected HCC cell line and its parent GPC3-nonexpressing cell line revealed that the increase in macrophages was stimulated by membrane expression of GPC3.
After hepatoma, cells were transfected with shRNA, GPC-3 expression or proliferation was inhibited with promoting apoptosis, cell cycle arrested in G1 phase, alteration of hepatoma cell migration and invasion behaviors with down-regulation of β-catenin, IGF-II, and VEGF, and growth of nude mice xenograft tumors was significantly suppressed with the decreases in β-catenin, p-GSK3β, and cyclinD1 expression, suggesting that GPC-3 not only is a specific biomarker for HCC diagnosis, but also is a valuable molecular-target for HCC gene therapy.
All 7 patients with GPC3-expressing HCCs exhibited an increase in GPC3-specific CTLs after RFA or TACE, whereas none of the 7 patients did after surgical resection.
All GPC3-CARs rendered T cells highly cytotoxic to GPC3-positive hepatocellular carcinoma, hepatoblastoma, and malignant rhabdoid tumor cell lines in vitro.