Human breast-cancer metastasis formation in a nude-mouse model: Studies of hyaluronidase, hyaluronan and hyaluronan-binding sites in metastatic cells

Abstract

Few animal models are available to study metastasis formation. The purpose of the present study was to obtain a useful model of metastasis formation in nude mice in an attempt to analyze the stroma reaction and in particular the production and the expression of hyaluronan (HA), hyaluronidase, and HA‐binding sites by cultivated cells, and HA and hyaluronectin (HN) in the invasive areas of tumors. Nude mice were subjected to i.p. injections of several human cancer cell lines (PLC/PRF/5, HepG2, CB 191, CB 193, PC3, CAL 51, SA 87 and SA 98), and formation of metastases was analyzed in different organs (lung, liver, kidney, spleen and axillary nodes) by immunohistochemical techniques. CAL 51, a breast‐cancer‐metastasis‐derived cell line with a normal karyotype, produced i.p. tumors in 75% animals and metastases in 90% animals (detected in the liver and axillary nodes). Two modes of invasion by CAL 51 cells were observed in the liver: one, direct, from the surface of the liver and the other, indirect, via the bloodstream. HA and HN were strongly expressed at the invasion areas. A cell line derived from hepatic metastasis of CAL 51 (HMD CAL 51) presented an abnormal karyotype. HMD CAL 51 produced more hyaluronidase (12‐fold) and HA (10‐fold) and expressed more CD44 (1.6‐fold) and other HA‐binding sites (9.5‐fold) than the established cell line CAL 51. Our results show that i.p. injection of the CAL 51 cell line into nude mice provides a useful model of metastasis formation. The passage of the CAL 51 cells from the primary state to the metastatic state was characterized by a dramatic increase of HA and hyaluronidase production, and expression of HA, HN and HA‐binding sites. Int. J. Cancer 82:77–83, 1999. © 1999 Wiley‐Liss, Inc.

Hyaluronidase gene profiling and role of HYAL‐1 overexpression in an orthotopic model of prostate cancer

“…In these situations, hyal-1 expression was frequently upregulated in the xenografts. This has been previously observed with the CAL51 cell line, 42 where it is suggested that the increase in hyal-1 expression plays a role in extravasation and metastasis. In addition it was recently shown by immunohistochemistry that hyal-1 has a stromal and epithelial pattern of staining that increased with prostate cancer grade and metastasis.…”

“…No increase was seen in the incidence, number, or size of tumor nodules across a range of sites after 80 days for the hyal-1 overexpressing cell line (data not shown). Interestingly, Victor et al 42 showed metastasis in nude mice after i.p. CAL51 administration and in addition the transition of these cells from the primary to the metastatic state was characterized by increased HA and hyaluronidase production.…”

Sublethal Irradiation Induces Vascular Endothelial Growth Factor and Promotes Growth of Hepatoma Cells: Implications for Radiotherapy of Hepatocellular Carcinoma

“…On the other hand, VEGF secretion can enhance distant metastasis, but metastasis formation also depends on the stroma reaction and cell type. That we did not see metastasis in the animal model might be because the microenvironment is not damaged by radiotherapy and the HepG2 cell line is nonmetastatic in nude mice (47). However, we did note that radiotherapy promoted both intrahepatic and extrahepatic tumor progression in hepatocellular carcinoma patients.…”

HYAL1 Hyaluronidase: A Molecular Determinant of Bladder Tumor Growth and Invasion

“…Contrarily, Victor et al showed that passage of a human breast cancer line CAL 51 from the primary state to metastatic stage increases hyaluronidase production (39). Expression of HYAL1 in a prostate cancer line that produces little hyaluronidase did not affect tumor growth but caused a slight increase in lung metastasis (40).…”