[Modulation of invasiveness and invasion/metastasis-associated gene expression of a mouse mammary adenocarcinoma by interferons].

OBJECTIVE

To investigate the effects of IFNs on the in vitro invasiveness and the expression of several genes related to invasion and metastatic behavior of MA-891 cells.

METHODS

The invasiveness was assessed by penetration through a matrigel-coated filter. Cell surface antigen and mRNA levels were analyzed by flow cytometry and Northern blot respectively.

RESULTS

IFN-gamma pretreatment increased the invasiveness of MA-891 (P < 0.01). Pretreatment with IFN-alpha decreased the invasiveness of cells, but it was not statistically significant. Cell surface ICAM-1 was not found on MA-891 cells even after treatment with IFN-alpha, but was strongly induced after IFN-gamma treatment. Another adhesion molecule CD44v mRNA, absent on MA-891 cells, could not be induced to express by either IFN. Both 72,000 and 92,000 type IV collagenase mRNAs were detectable in MA-891 cells. The 72 kD-type IV collagenase expression was up-regulated by IFN-gamma and IFN-alpha, but the levels of expression were significantly higher in cells treated with IFN-gamma than those treated with IFN-alpha. IFN-gamma and IFN-alpha treatment had little or no effect on expression of the 92,000 type IV collagenase. Treatment with IFN-gamma had no effects on antimetastasis nm23 gene expression whereas treatment with IFN-alpha resulted in marked up-regulation of its expression.

CONCLUSION

IFN-gamma and IFN-alpha differ in their effects on the expression of genes related to invasion and metastasis of MA-891 cells, thereby differentially modulating metastatic potential.