Figure 3
LAK cell binding of MDA-MB-231 breast carcinoma cell lines as shown by conjugate formation assay. 1 × 105 LAK cells (0.1 ml) and 1 × 105 target cells (0.1 ml) were mixed in the same tube, centrifuged for 2 min at 500 g and incubated at 37°C for 10 min. The cells stained with trypan blue were observed under phase contrast microscope. 2 LAK cells forming a conjugate with a live tumor cell is demonstrated in Fig. 4. A LAK cell was observed to form a conjugate with a blue-dead tumor cell is visible in Fig. 5. Two blue-dead tumor cells are also seen in this picture. The percentage of LAK cells attached to the targets and vice versa was counted in a modified Cunningham chamber. And the data represent the arithmetic mean ± standard deviation of the mean percent LAK cells conjugated to targets (LAK:Target) of 4 independent experiments. The percentage of LAK:Target cell conjugates formed by the MDR breast carcinoma cell lines was found to be higher than that formed by the drug-sensitive parent cell line MDA-MB-231. This increase was statistically significant at p < 0.05 for MPAM 26, MPAHS-1-10, and MPAHS-DOX150, and at p = 0.01 for MPAHS-1-300 (Student's paired "t" test, 1-sided). 1 = MDA-MB-231 2 = MPAM 26 3 = MPAHS-1-10 4 = MPAHS-1-300 5 = MPAHS-DOX-150