Expression ofnma, a novel gene, inversely correlates with the metastatic potential of human melanoma cell lines and xenografts

Abstract

Metastatic melanoma is one of the most invasive cancers, the incidence of which has rapidly increased in the past decade. The process of metastasis is thought to be characterized by subsequent distinct stages as defined by Clark et at. (1984) and Hcrlyn et ul. (1987), and cventually cnablcs a primary tumor to sprcad and colonize at sccondary sites. A sct of biological markers defining unequivocally each stage of tumor development is lacking. New markers are thus sought for better diagnosis and therapeutic strategies. They may also lead to a better understanding of the tumor biology of melanoma.In cultured human melanocytic cells, several tumor markers have been defined that are possibly indicative for metastatic potential (Wcterman et al., 1994). Some of these markers may be vcry useful in clinical practice as wcll as in studies of tumor biology. Several strategies have been used to isolate tumor progression markers. The use of monoclonal antibodies (MAbs). in particular, was successful in the isolation of membrane associated proteins, such as membrane receptors and adhesion molecules (Real et al., 1985). A number of melanoma markers represent (potential) tumor suppressor activities, e.g., nm23 (Leone et uL, 1091) andpZ6 (Kamb el al., 1994).In the last few ycars, we have idcntified scveral potcntial progression markers, e.g., calcyclin (Weterman et ul., 1992), thymosin-pl0 (Weterman et al., 1993), nmb (Weterman et al., 1995 and nma (this report), by using differential and subtractive hybridization techniques. Calcyclin and thymosin-pl0 are expressed in highly metastatic human melanoma cell lines: whereas nrna and nrnb are expressed in poorly metastatic human melanoma cell lines.Thc absence of cxpression of nrna and nmb in highly metastatic ccll lines docs not imply a rolc in tumor progrcssion, It merely indicates that these markers are part of the phenotype of a non-metastasizing cell line. Because this phenotype may be relevant for tumor biology, we now present a characterization of the nma gene. MATERIAL AND METHODS Biological ma teria IsHuman melanoma cell lines 1F6,530, BLM, MV3 and MV1 (van Muijen et al., 1991a, b, c ) were cultured as described by Weterman et al. (1992). In this pancl of ccll lincs, BLM and MV3 reprcscnt thc highly metastatic cell lines, i.e., those i n which metastases occur in more than 50% of the tumorbearing mice. 1F6, 530 and MV1 produced metastases in less than 10% of the tumor-bearing mice, representing the poorly metastatic cell lines (van Muijen et al., 1 9 9 1~) ; 3 X lo6 cells were used for S.C. inoculation into nude mice (nulmu BALB/c; Bomholtgaard, Ry, Denmark). Excision and processing of the human tissues was pcrformcd as described by Weterman et al. (1995).

nmd, a novel gene differentially expressed in human melanoma cell lines, encodes a new atypical member of the enzyme family of lipases

“…Its presence, however, in a considerable number of human melanoma metastatic lesions seems to be in contrast with this suggestion. It is remarkable that other potential early progression markers, notably «TO23 [25], nma [26] and nmb [27] display a similar expression distribution. Genes like wm23, nma, nmb and also nmd may be involved in attenuating metastatic properties of melanoma cells, possibly as a consequence of tumor-host interactions.…”

“…Genes like wm23, nma, nmb and also nmd may be involved in attenuating metastatic properties of melanoma cells, possibly as a consequence of tumor-host interactions. Tumor progression may require that genes are (temporarily) switched off in the course of metastasis, but sometimes turned on again later in a secondary, distantly growing tumor [4,26].…”

Mel-CAM-specific genetic suppressor elements inhibit melanoma growth and invasion through loss of gap junctional communication

“…Aggregation between cells was measured by a doublecolor assay (Degen et al, 1998) in which two separate cell suspensions were stained for 60 min with¯uorescent green 5-sulfo¯uorescein diacetate 50 mg/ml or red hydroxyethidine 40 mg/ml, washed and mixed in equal numbers. After 30-min incubation at 378C, cells were ®xed in 2% paraformaldehyde and analysed in a¯ow cytometer.…”

The Pseudoreceptor BMP and Activin Membrane-bound Inhibitor Positively Modulates Wnt/β-Catenin Signaling

“…The human BAMBI, initially named as nma, is down-regulated in metastatic melanoma cell lines (22), and has been implicated to promote cell growth and invasion in human gastric carcinoma cell lines (27). A recent study has also suggested that BAMBI is involved in Toll-like receptor 4-and lipopolysaccharide-mediated hepatic fibrosis (26).…”