Inhibition of tumor formation and metastasis by a monoclonal antibody against lymphatic vessel endothelial hyaluronan receptor 1

Abstract

Although cancer metastasis is associated with poor prognosis, the mechanisms of this event, especially via lymphatic vessels, remain unclear. Lymphatic vessel endothelial hyaluronan receptor 1 (LYVE‐1) is expressed on lymphatic vessel endothelium and is considered to be a specific marker of lymphatic vessels, but it is unknown how LYVE‐1 is involved in the growth and metastasis of cancer cells. We produced rat monoclonal antibodies (mAb) recognizing the extracellular domain of mouse LYVE‐1, and investigated the roles of LYVE‐1 in tumor formation and metastasis. The mAb 38M and 64R were selected from hybridoma clones created by cell fusion between spleen cells of rats immunized with RH7777 rat hepatoma cells expressing green fluorescent protein (GFP)‐fused mouse LYVE‐1 proteins and mouse myeloma cells. Two mAb reacted with RH7777 and HEK293F human embryonic kidney cells expressing GFP‐fused mouse LYVE‐1 proteins in a GFP expression‐dependent manner, and each recognized a distinct epitope. On immunohistology, the 38M mAb specifically stained lymphatic vessels in several mouse tissues. In the wound healing assay, the 64R mAb inhibited cell migration of HEK293F cells expressing LYVE‐1 and mouse lymphatic endothelial cells (LEC), as well as tube formation by LEC. Furthermore, this mAb inhibited primary tumor formation and metastasis to lymph nodes in metastatic MDA‐MB‐231 xenograft models. This shows that LYVE‐1 is involved in primary tumor formation and metastasis, and it may be a promising molecular target for cancer therapy.

Anti‐tumor effects of mAb against l‐type amino acid transporter 1 (LAT1) bound to human and monkey LAT1 with dual avidity modes

“…In this context, we have recently reported a novel therapy targeting lymphangiogenesis, but not angiogenesis, using an anti-LYVE-1 mAb. 53 At present, many transporters are not considered to be target molecules for cancer therapy; however, this study strongly suggests that inhibition of cancer metabolism by mAbs against amino acid transporters will play a significant role in future cancer therapies.…”

“…The target molecules of existing anticancer therapeutic antibodies are divided into: (i) receptor‐type tyrosine kinases; (ii) differentiation antigens; (iii) angiogenesis‐related molecules; and (iv) immune checkpoint molecules. In this context, we have recently reported a novel therapy targeting lymphangiogenesis, but not angiogenesis, using an anti‐LYVE‐1 mAb . At present, many transporters are not considered to be target molecules for cancer therapy; however, this study strongly suggests that inhibition of cancer metabolism by mAbs against amino acid transporters will play a significant role in future cancer therapies.…”

Lymphangiogenesis and Lymph Node Metastasis in Oral Squamous Cell Carcinoma

“…LYVE-1 was associated with tumor progression and metastasis, which could be used to identify tumor-associated lymphogenesis (17). Hara et al showed that LYVE-1 was involved in primary tumor formation and metastasis (18). It was up-regulated in muscleinvasive bladder cancers, exhibiting positive lympho-vascular invasion and LN metastasis compared to non-muscle invasive bladder cancers (19).…”

Novel functional anti-HER3 monoclonal antibodies with potent anti-cancer effects on various human epithelial cancers

“…Cell lines originated from various organs, which are depicted and listed in Figure 3, and described in a previous publication [50]. All cells were cultured in RD medium [51], which is a 1:1 mixture of Dulbecco's modified Eagle's and RPMI-1640 medium (Nissui Pharmaceutical Co, Ltd, Tokyo, Japan) supplemented with 7% heat-inactivated fatal bovine serum (FBS, Thermo Fisher Scientific Inc., Waltham, MA, USA), humidified in CO 2 incubators.…”