Anti-podocalyxin antibody exerts antitumor effects via antibody-dependent cellular cytotoxicity in mouse xenograft models of oral squamous cell carcinoma

Abstract

Podocalyxin (PODXL) overexpression is associated with progression, metastasis, and poor outcomes in cancers. We recently produced the novel anti-PODXL monoclonal antibody (mAb) PcMab-47 (IgG1, kappa). Herein, we engineered PcMab-47 into 47-mG2a, a mouse IgG2a-type mAb, to add antibody-dependent cellular cytotoxicity (ADCC). We further developed 47-mG2a-f, a core fucose-deficient type of 47-mG2a to augment its ADCC. Immunohistochemical analysis of oral cancer tissues using PcMab-47 and 47-mG2a revealed that the latter stained oral squamous cell carcinoma (OSCC) cells in a cytoplasmic pattern at a much lower concentration. PcMab-47 and 47-mG2a detected PODXL in 163/201 (81.1%) and in 197/201 (98.0%) OSCC samples, respectively. 47-mG2a-f also detected PODXL in OSCCs at a similar frequency as 47-mG2a. In vitro analysis revealed that both 47-mG2a and 47-mG2a-f exhibited strong complement-dependent cytotoxicity (CDC) against CHO/hPODXL cells. In contrast, 47-mG2a-f exhibited much stronger ADCC than 47-mG2a against OSCC cells, indicating that ADCC and CDC of those anti-PODXL mAbs depend on target cells. In vivo analysis revealed that both 47-mG2a and 47-mG2a-f exerted antitumor activity in CHO/hPODXL xenograft models at a dose of 100 μg or 500 μg/mouse/week administered twice. 47-mG2a-f, but not 47-mG2a, exerted antitumor activity in SAS and HSC-2 xenograft models at a dose of 100 μg/mouse/week administered three times. Although both 47-mG2a and 47-mG2a-f exerted antitumor activity in HSC-2 xenograft models at a dose of 500 μg/mouse/week administered twice, 47-mG2a-f also showed higher antitumor activity than 47-mG2a. These results suggested that a core fucose-deficient anti-PODXL mAb could be useful for antibody-based therapy against PODXL-expressing OSCCs.

Anti-Metastatic Activity of an Anti-EGFR Monoclonal Antibody against Metastatic Colorectal Cancer with KRAS p.G13D Mutation

“…However, EMab-17 could not inhibit or diminish the presence of all CRC cells in the liver. As previously reported by this and other research groups, afucosylation of the Fc domain to increase the ADCC, and/or the combination of EMab-17 with anti-cancer drugs, are needed to enhance the anti-metastatic activity of EMab-17 [ 36 , 37 , 38 , 39 ]. In future studies, we need to generate a human/mouse chimeric anti-EGFR antibody from EMab-17 in order to develop the therapeutic antibody.…”

“…Additional antibodies were injected on days 7 and 14. The tumor diameter and volume were determined as previously described [ 38 ]. The mice were euthanized 21 days after cell implantation.…”

PODXL Might Be a New Prognostic Biomarker in Various Cancers: A Meta-analysis and Sequential Verification with TCGA Datasets

“…High expression of miR-509-3-5p and miR-5100 inhibited the invasion and metastasis of gastric cancers and pancreatic cancers by directly targeting PODXL, functioning as a tumor suppressor [27,40]. A core fucose-deficient monoclonal antibody (mAb) of PODXL might be a new antibody-based therapy method against PODXL high-expressed oral squamous cell carcinoma [47].…”

Podocalyxin is crucial for the growth of oral squamous cell carcinoma cell line HSC-2

“…In our previous study, we established specific and sensitive anti-PODXL mAbs: PcMab-47 (mouse IgG 1 , kappa) [20] , 47-mG 2a (mouse IgG 2a -type of PcMab-47), and 47-mG 2a -f (core fucose-deficient type of 47-mG 2a ) [21] . We demonstrated that 47-mG 2a -f significantly reduced tumor growth in OSCC xenograft models.…”

“…We demonstrated that 47-mG 2a -f significantly reduced tumor growth in OSCC xenograft models. [21] . To investigate the function of PODXL in the growth of oral cancer cells, we previously generated PODXL-knock out (PODXL-KO) cell lines using SAS OSCC cell lines.…”