Induction of invasive and metastatic potential in mouse T-lymphoma cells (BW5147) by treatment with 5-azacytidine

Abstract

Non-invasive, non-metastatic mouse BW5147 T-lymphoma cells were treated with non-mutagenic concentrations of the hypomethylating agent 5-azacytidine (5-aza-C). Subsequently, invasive variants were selected on monolayers of rat embryo fibroblasts. The estimated frequency of induction of invasive variants was smaller than 1 in 10(6) cells. We obtained several independent clones that were stable in the expression of the invasive phenotype. In contrast to the parental cell line, the highly invasive clones produced widespread metastases upon tail vein injection in all the syngeneic AKR mice tested, whereas clones with an intermediate level of invasiveness formed metastases only in part of the mice tested. DNA analysis using the methylation-sensitive and insensitive restriction enzymes, Hpa-II and Msp-I, respectively, showed that the DNA of the invasive variants remained hypomethylated, up to 6 months after 5-aza-C treatment. 5-aza-C is thus able to induce invasive and metastatic potential in the BW5147 T-lymphoma cells, similar to the activated human c-Ha-ras oncogene or human chromosome 7, as studied previously. The acquisition of invasive and metastatic potential is presumably caused by DNA hypomethylation and thus activation of one or more silent invasion controlling genes.

DNA demethylation and invasive cancer: implications for therapeutics

“…It was reported that 0.2 μM 5-azaC inhibits invasiveness of human breast carcinoma MDA-MB-468 cells (Bandyopadhyay et al, 2004); 5 μM 5-azaC reduces migration of a human non-small cell lung carcinoma cell line H1299 (Mateen et al, 2013); 10 μM 5-azaC reduces migration and invasiveness in ovarian tumour cells BeWo (Rahnama et al, 2006), and 5-azadC inhibits migration and invasion of bladder cancer T24 cell line . However, other studies that span several decades have demonstrated an increase in cell invasion and metastasis in animal tumour models (Olsson and Forchhammer, 1984;Habets et al, 1990). One and 5 μM 5-azadC convert nonmetastatic breast cancer cell lines (MCF-7 and ZR-75-1) to invasive cells in vitro and in vivo (Ateeq et al, 2008;Chik et al, 2014); 5 μM 5-azadC increases human fibrosarcoma HT1080 cells invasion through induction of matrix metalloproteinase-1 (MMP-1), which was up-regulated 44.6-fold through recruitment of RNA Pol II and Sp1 to its promoter compared with non-treated cells.…”

Patterns of methylation of the c-myc gene in human colorectal cancer progression

“…We Methylation of cytosine residues of DNA, especially in CpG dinucleotide sequences, is thought to be closely involved with gene expression (Razin & Riggs, 1980;Bird, 1986). It has been established for some time that both the extent and the specific pattern of DNA metlylation may be altered in human tumours (Feinberg & Vogelstein, 1983); treatment of cultured T-lymphoma cells with the hypomethylating agent 5-azacytidine causes them to become invasive and metastatic in vivo (Habets et al, 1990). Hypomethylation of the 5' end of a gene tends to be associated with its expression; altered methylation patterns of genes involved in regulation of the cell cycle and proliferation may thus be directly related to the mechanism of malignancy.…”

Sublocalization of an invasion-inducing locus and other genes on human chromosome 7

“…1987b). by DNA hypomethylation (Habets et al, 1990), and by somatic cell hybridization (Roos et al, 1985;Collard et al, 1987a) leads to concomitant acquisition of metastatic potential, indicating that invasive capacity of these T-lymphomas is a major prerequisite for metastasis formation. In the somatic cell hybridization studies we found that T-cell hybridomas gener ated by in vitro fusion of noninvasive mouse BW5147 cells with either activated normal mouse (Roos et al, 1985;la Rivière et al, 1988) or human T-cells (Collard et al.…”