Glypican-1-targeted antibody-drug conjugate inhibits the growth of glypican-1-positive glioblastoma.

Glioblastoma is the deadliest form of brain tumor. The presence of the blood-brain barrier (BBB) significantly hinders chemotherapy, necessitating the development of innovative treatment options for this tumor. This report presents the in vitro and in vivo efficacy of an antibody-drug conjugate (ADC) that targets glypican-1 (GPC1) in glioblastoma. The GPC1-ADC was created by conjugating a humanized anti-GPC1 antibody (clone T2) with monomethyl auristatin E (MMAE) via maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl linkers. Immunohistochemical staining analysis of a glioblastoma tissue microarray revealed that GPC1 expression was elevated in more than half of the cases. GPC1-ADC, when bound to GPC1, was efficiently and rapidly internalized in glioblastoma cell lines. It inhibited the growth of GPC1-positive glioma cell lines by inducing cell cycle arrest in the G2/M phase and triggering apoptosis in vitro. We established a heterotopic xenograft model by subcutaneously implanting KALS-1 and administered GPC1-ADC intravenously. GPC1-ADC significantly inhibited tumor growth and increased the number of mitotic cells. We also established an orthotopic xenograft model by intracranially implanting luciferase-transfected KS-1-Luc#19. After injecting Evans blue and resecting brain tissues, dye leakage was observed in the implantation area, confirming BBB disruption. We administered GPC1-ADC intravenously and measured the luciferase activity using an in vivo imaging system. GPC1-ADC significantly inhibited tumor growth and extended survival. In conclusion, GPC1-ADC demonstrated potent intracranial activity against GPC1-positive glioblastoma in an orthotopic xenograft model. These results indicate that GPC1-ADC could represent a groundbreaking new therapy for treating glioblastoma beyond the BBB.

The Prognostic Impact of Leucine-Rich α-2-Glycoprotein-1 in Cholangiocarcinoma and Its Association With the IL-6/TGF-ß1 Axis.

BACKGROUND: Leucine-rich α-2-glycoprotein-1 (LRG) has been found to participate in the development of various cancers through its involvement in TGF-ß1-induced epithelial-mesenchymal transition (EMT) and/or angiogenesis and can be induced by inflammatory cytokines, such as IL-6. As we previously showed the implication of IL-6/TGF-ß axis in EMT of cholangiocarcinoma cells, we herein explored the prognostic impact of LRG in postoperative intrahepatic cholangiocarcinoma (ICC) and assessed the association between tumor LRG and factors such as TGF-ß1, IL-6, and the tumor microvessel density. METHODS: We determined the expression of LRG, IL-6, TGF-ß1, and CD31 in cancer tissues from 50 ICC patients by immunohistochemistry and analyzed their association with the prognosis. RESULTS: The LRG expression was closely associated with recurrence-free survival (RFS) and overall survival (OS) in postoperative ICC. A multivariate Cox regression model indicated that LRG as an independently associated with poor RFS (hazard ratio = 2.4339, P = 0.0354) and OS (hazard ratio = 2.8892, P = 0.0268). The LRG expression was significantly associated with the expression of TGF-ß1 (P = 0.0003) and IL-6 (P = 0.0164). CONCLUSIONS: The upregulation of LRG in tumors was an independent prognostic factor in patients with postoperative ICC. LRG was closely associated with the TGF-ß1 expression and seems to be an important member of the IL-6/TGF-ß1 axis.

Epithelial-mesenchymal transition via transforming growth factor beta in pancreatic cancer is potentiated by the inflammatory glycoprotein leucine-rich alpha-2 glycoprotein.

We previously showed that an inflammation-related, molecule leucine-rich alpha-2 glycoprotein (LRG) enhances the transforming growth factor (TGF)-ß1-induced phosphorylation of Smad proteins and is elevated in patients with pancreatic ductal adenocarcinoma (PDAC). As TGF-ß/Smad signaling is considered to play a key role in epithelial-mesenchymal transition (EMT), we attempted to clarify the mechanism underlying LRG-related EMT in relation to metastasis in PDAC. We cultured LRG-overexpressing PDAC cells (Panc1/LRG) and evaluated the morphology, EMT-related molecules and TGF-ß/Smad signaling pathway in these cells. We also assessed the LRG levels in plasma and resected specimens from patients with PDAC. Inflammatory cytokines induced LRG production in PDAC cells. A spindle-like shape was visualized more frequently than other shapes in Panc1/LRG with TGF-ß1 exposure. The expression of E-cadherin in Panc1/LRG was decreased with TGF-ß1 exposure. Invasion increased with TGF-ß1 stimulation of Panc1/LRG. The phosphorylation of smad2 in Panc1/LRG was increased in comparison with parental Panc1 under TGF-ß1 stimulation. In the plasma LRG-high group, the recurrence rate tended to be higher and the recurrence-free survival (RFS) tended to be worse in comparison with the plasma LRG-low group. LRG enhanced EMT induced by TGF-ß signaling, thus indicating that LRG has a significant effect on the metastasis of PDAC.