[Correlation of Ca2+ current features of nasopharyngeal carcinoma cells with different metastatic potentiality to their moving abilities]

Abstract

Background & objective: The metastatic potentiality of malignancies is closely associated with their biological dynamic properties, which are affected by intracellular Ca2+ current activity. This study was to investigate the correlation of Ca2+ current features of sub-clonal nasopharyngeal carcinoma (NPC) cell lines 5-8F and 6-10B with different metastatic potentiality to their moving abilities.

Methods: 5-8F cells, with higher metastatic potentiality, and 6-10B cells, with lower metastatic potentiality, were cultured with herbal medicine-containing serum, which holds significant metastasis-inhibiting effect on tumor cells. Cell proliferation was assessed by MTT assay. The expression of nm23-H1 was detected by Western blot. Intracellular Ca2+ current features were detected with patch clamp technique in a whole cell recording way, while cell moving ability was determined by streak culturing assay.

Results: The expression of nm23-H1 was significantly lower in 5-8F cells than in 6-10B cells (2.3+/-0.2 vs. 2.9+/-0.4). The Ca2+ release-activated Ca2+ influx current (ICRAC) was significantly lower in 5-8F cells than in 6-10B cells [(-1.39+/-0.36) nA vs. (-0.66+/-0.40) nA, P < 0.05]. The number of cells moved across the streak was significantly higher in 5-8F cells than in 6-10B cells (350+/-3 vs. 246+/-1, P< 0.05). When cultured with herbal medicine-containing serum, no significant difference in proliferation was found between 5-8F cells and 6-10B cells; the expression of nm23-H1 was significantly higher in 5-8F cells than in 6-10B cells(3.9+/-0.1 vs.1.0+/-0.1,P<0.05)û the ICRAC was decreased to (-1.27+/-0.35) nA in 5-8F cells and decreased to (-0.37+/-0.23) nA in 6-10B cell, and the inhibition rate was significantly higher in 5-8F cells than in 6-10B cells [(1.90+/-0.47)% vs. (0.46+/-0.12)%, P < 0.05]û the number of cells moved across the streak was significantly lower in 5-8F cells than in 6-10B cells (94+/-6 vs. 229+/-6, P < 0.05).

Conclusions: There are significant differences in nm23-H1 protein expression, ICRAC level and cell moving ability between 5-8F and 6-10B cells. Medicine intervention could inhibit Ca2+ current and moving ability of 5-8F cells, and meanwhile increase the nm23-H1 activity.