Figure 5. IP3K2 expression and Ca²⁺ entry were up-regulated in osteosarcoma cells following treatment with chemotherapeutic drugs.

(A and B) Analyses of IP3K2 mRNA and protein levels in Soas-2 cells after drug treatment. (C and D) Analyses of IP3K2 mRNA and protein levels in MG-63 cells after drug treatment. (E) Representative tracings of Fura-2 fluorescence ratio in fluorescence spectrometry during and after Ca²⁺ depletion with subsequent thapsigargin (1 μM) addition in Soas-2 cells without (white squares) and with presence of Dox (0.2 μg/ml, black squares) or Cis (20 nM, grey squares). (F and G) Arithmetic means (±S.E.M., n=5–6, each experiment 10–30 cells) of slope (C) and peak (D) increase in Fura-2 fluorescence ratio following Ca²⁺ readdition in the absence (white bars) and presence of drug (black or grey bars). * (P<0.05) indicate statistically significant difference from control.