Table 1 Efficacy of chemotherapeutic drugs in TS

From: A model of quiescent tumour microregions for evaluating multicellular resistance to chemotherapeutic drugs

 

TS P

TS Q

Drug

IC50 (μ M)

Extent of cell kill (% of total cells)

IC50 (μ M)

Extent of cell kill (% of total cells)

Vinblastine

1.4±0.7

88±5

No IC50 at max conc.

34±12

Doxorubicin

0.8±0.2

93±5

13±5a

81±10

Cisplatin

3.3±1.2

100±0

84±30a

80±12

5-FU

25±8

88±4

No IC50 at max conc.

11±11

  1. TSP=proliferating tumour spheroids; TSQ=quiescent tumour spheroids; 5-FU=5-fluorouracil.
  2. TSP and TSQ were exposed to a range of concentrations of chemotherapeutic drugs (1 nM to 316 μm (up to 1 mM for 5-FU)) for 16 h. The TS were incubated in drug-free medium for a further 6-day (recovery) period to allow the cytotoxic effects of the drugs to be realised. After this time, the methylene blue assay was performed. The potency of the drug to elicit cytotoxicity was expressed as an IC50 value determined from dose–response curves as described in the Materials and Methods. The extent of the cell kill in the TS was expressed as a percentage of control for the highest concentration of drug tested. Six replicates were performed for each drug concentration with the values obtained from three or more independent observations being shown as mean±s.e.m.
  3. aIndicates statistical significance (P<0.05).
Back to article page