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In vitro models are required for the study of these cancers, and several cell lines have already been established and characterised (Lafargues & Ozzello, 1958;Soule et al., 1973;Cailleau et al., 1974;Engel et al., 1978;Whitehead et al., 1983;Yamane et al., 1984;Chu et al., 1985;Vandewalle et al., 1987). Nevertheless, owing to the heterogenity and the diversity of mammary cancers, a great number of cell models is necessary to understand the reasons for this diversity and the effect of anticancer drugs on tumour cells.Cytogenetic studies of mammary adenocarcinoma cell lines are essential for comprehension of the pathogenesis of these cancers (Trent, 1985;Gebhart et al., 1986). The implication of chromosomal alterations in these pathologies has opened a new and promising route towards better knowledge of these cancers (Cervenka & Koulischer, 1973). Chromosomal alterations are generally numerous, and markers often demonstrate hyperploidy in these cancers (Sandberg, 1980). Demonstration of the minimum genetic alterations indispensable for cell transformation is difficult, and might be easier on cells with a karyotype closer to normal. Sandberg and Wolman mentioned the existence of such cells, but most of their results concerned karyotype studies without chromosome banding (Sandberg, 1980;Wolman, 1983 [-', hyaluronidase 25 IU for 20 ml, Hepes buffer 4.8 g 1' in distilled water). Cells were then fixed in acetic acid:methanol (1:3) and dropped onto grease-free, cooled slides for chromosome counting and examination. R bands were obtained by heat denaturation of the chromosomes according to the method of Dutrillaux and Lejeune (1971). Xenografted CAL51 cells were plated and studied in vitro in the same manner.

Permanent human osteosarcoma cell lines are important tools for the study of bone cancer. As representative of an osteoblastic phenotype, they partly reflect their normal osteoblastic counterparts and, thus, may represent appropriate models to investigate the mechanisms involved in bone remodelling and in haematopoietic differentiation. In the present work, we describe a new human cell line, CAL 72, obtained from an osteosarcoma of the knee of a 10‐year‐old boy. These cells grow in continuous culture, and karyotypic analysis has revealed clonal abnormalities in number and structure, especially loss of chromosome Y. These cells exhibit morphological, immuno‐histochemical and molecular characteristics of the osteoblastic lineage. Using RT‐PCR, we have shown that the CAL 72 cell line expresses high levels of mRNA coding for several cytokines, such as G‐CSF, GM‐CSF, IL‐1β and IL‐6. In view of this expression profile, the CAL 72 phenotype appears to be closer to normal primary osteoblasts than other reported osteosarcomas. Moreover, these cells express mRNA for both HGF and its receptor c‐MET, suggesting that this autocrine loop might contribute to the invasiveness of the tumour from which CAL 72 originated. Int. J. Cancer82:282–285, 1999. © 1999 Wiley‐Liss, Inc.

Lacassagne, 36 voie Romaine, 06054 Nice Cedex, France.S_mary The qualitative and quantitative importance of tamoxifen (TMX) metabolism in vivo led us to investigate further the metabolic profile of this major anti-oestrogenic drug in a significant group of 81 breast cancer patients and to evaluate the respective in vitro activity of each metabolite. TMX and its four metabolites described until now (NDT, Y, Z) were measured in blood (HPLC method) at the time of first drug intake and at the steady state. Between these two states, the unchanged drug relative proportion dropped from 65% to 27%. Demethylation was the major metabolic pathway. For 13 clinically evaluable patients, there was no significant difference in the distribution of serum levels of TMX and metabolites as a function of response to treatment. In vitro studies were performed on two human breast cancer cell lines: MCF-7, oestrogen receptor and progesterone receptor positive (ER+, PR+) and CAL-18 B (ER-, PR-). Cytostatic effects were evaluated by the tritiated thymidine incorporation test. TMX and all metabolites were active on these two cell lines, but the 50% inhibitory concentrations (IC 50) were 4-250-fold higher in CAL-18 B than in MCF-7, depending on the metabolite considered. For the MCF-7 cells only, the antiproliferating activity was parallel to the relative binding affmity for ER. Moreover, for the MCF-7 cells only, the effects of these drugs were partially reversed by oestradiol (E2), the higher the metabolite affinity for ER, the lower the reversal efficacy. These compounds were tested in mixtures at proportions duplicating those found in patients after initial drug intake (mixture Dl), and the steady state (mixture Css). The mixtures were also compared to the equimolar unchanged drug. No differences were seen among these three experimental conditions for either MCF-7 or CAL-18 B. A dose-effect relationship was noted. Overall, TMX and its metabolites exert a dual effect when concentrations are below a threshold between 2 x 10 -6 and 10-5 M, the drugs are mainly cytostatic; this effect is related to their affinity for ER. At higher relevant clinical concentrations, a cytotoxic activity is observed and it appears independent of the presence of ER.Tamoxifen (TMX) is one of the most widely used form of endocrine therapy for patients with breast cancer (Furr & Jordan, 1984). Several trials have established the importance of this agent in delaying relapse (Baum et al., 1985) and in significantly prolonging survival (Fischer et al., 1987). It is generally recognised that breast cancer patients with positive oestradiol (E2) and progesterone (P) receptors (R) respond better to TMX than those with negative receptors. But there are both clinical (Baum et al., 1985; Vogel et al., 1987) and experimental (Miller et al., 1984; Katzenellenbogen et al., 1985) data which suggest that the effects of TMX on tumour growth should not be considered as merely an inhibition of the action of oestrogens. Several reports have pointed out the quantitative (Ada...

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.