Stromal Versican Regulates Tumor Growth by Promoting Angiogenesis

Keiichi Asano,Noriko Aramaki-Hattori,Sumeda Nandadasa,Suneel S Apte,Tyler Alban,Daniel J Lindner,Takashi Ohtsuki,Junko Inagaki,Courtney M Nelson,Toshitaka Oohashi,Satoshi Hirohata

doi:10.1038/s41598-017-17613-6

Keiichi Asano, Noriko Aramaki-Hattori + Show 9 more

Open Access

https://doi.org/10.1038/s41598-017-17613-6

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Abstract

The proteoglycan versican is implicated in growth and metastases of several cancers. Here we investigated a potential contribution of stromal versican to tumor growth and angiogenesis. We initially determined versican expression by several cancer cell lines. Among these, MDA-MB231 and B16F10 had none to minimal expression in contrast to Lewis lung carcinoma (LLC). Notably, tumors arising from these cell lines had higher versican levels than the cell lines themselves suggesting a contribution from the host-derived tumor stroma. In LLC-derived tumors, both the tumor and stroma expressed versican at high levels. Thus, tumor stroma can make a significant contribution to tumor versican content. Versican localized preferentially to the vicinity of tumor vasculature and macrophages in the tumor. However, an ADAMTS protease-generated versican fragment uniquely localized to vascular endothelium. To specifically determine the impact of host/stroma-derived versican we therefore compared growth of tumors from B16F10 cells, which produced littleversican, in Vcanhdf/+ mice and wild-type littermates. Tumors in Vcanhdf/+ mice had reduced growth with a lower capillary density and accumulation of capillaries at the tumor periphery. These findings illustrate the variability of tumor cell line expression of versican, and demonstrate that versican is consistently contributed by the stromal tissue, where it contributes to tumor angiogenesis.

Highlights

Angiogenesis, the formation of neovasculature from pre-existing capillaries, is a crucial event during malignant tumor progression
B16F10- cells did not express versican, whereas Lewis lung carcinoma (LLC) cells showed high levels of Vcan V0 and V1 mRNA comparable to the aorta (Supplementary Fig. S2C,D)
Western blotting confirmed a lack of versican GAGβ, representing isoforms V0/V1 in MDA-MB231- and B16F10-cells compared to LLC cells and mouse embryo lysate as a positive control (Fig. 1A)

Summary

Introduction

Angiogenesis, the formation of neovasculature from pre-existing capillaries, is a crucial event during malignant tumor progression. The tumor contains an extracellular matrix (ECM), which may be contributed by the stromal or tumor cells. It includes proteoglycans, hyaluronan (HA), collagens, and a variety of glycoproteins. Versican and its recombinant domains are implicated in regulating cell proliferation, differentiation, apoptosis, migration and adhesion in a variety of cancers[12,13]. Cleave versican at a specific site in the GAGβ region and ADAMTS4 has been shown to cleave an additional, poorly characterized site in the GAGα domain (Supplementary Fig. S1C)[9]. ADAMTS proteolysis of the V1 isoform generates an N-terminal G1 domain-containing fragment named versikine, which was implicated in regulation of apoptosis during limb development and myeloma growth[33]. We investigated the contribution of stromal production of versican and of versican cleavage to tumor angiogenesis

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