Effect of histamine on the expression of metalloproteinases and cell adhesion in breast cancer cell lines

Abstract

Changes in cell adhesion and matrix metalloproteinases production (MMPs) are pivotal for tumour progression to occur. MMPs degrade extracellular matrix, MMP2, MMP9 and MMP7 being associated with the malignant potential of cancer cells. MMPs proteolytic activity is precisely regulated by the endogenous tissue inhibitors of metalloproteinases (TIMPs). Histamine (HA) has been demonstrated to be an autocrine and paracrine growth factor in several neoplasms, modulating cell survival and invasiveness. Our aim was to study the effect of HA on cell adhesion, expression and activity of MMP2, MMP7 and MMP9 in human tumorigenic and non-tumorigenic mammary cell lines, MDA-MB-231 and HBL-100, respectively. MMPs protein expression was evaluated by immunocytochemistry, mRNA levels by RT-PCR and gelatinolytic activity by zimography. TIMP1 and TIMP2 mRNA levels were measured by RT-PCR. Cell adhesion was assessed by spectrophotometric measurement of methylene blue stained adherent cells. HBL-100 showed lower basal gelatinolitic levels than MDA-MB-231 cells. Basal activity and mRNA levels of MMP2 were higher than MMP9 in HBL-100, while MMP9 acitivity and RNA levels were predominant in MDA-MB-231. MMP7 protein and mRNA levels were very low in both cell lines. A significant basal expression of TIMP1 and TIMP2 mRNA levels was observed in these cell lines. 10 microM HA treatment reduced MMP9 and MMP2 activity and mRNA levels in MDAMB- 231 cells, while TIMP1 and TIMP2 mRNA levels were unaffected. In HBL-100, 10 microM HA slightly reduced MMP2 activity. Regarding cell adhesion, it was diminished by 10 microM HA in MDA-MB-231, but increased in HBL100 cells. These results disclose the ability of HA to modulate MMPs and cell adhesion in both cell lines, suggesting a potential role of HA in the events involved in mammary carcinoma progression.