Table 1 Glucose and insulin increase proliferation and migratory activity of different tumour cell lines

	2.75 m M	5.5 m M	11 m M	22 m M	5.5 m M +insulin	11 m M +insulin
(A) Proliferation (%) in comparison to 5.5 m M glucose
HT29	89.8^*	100.0	113.4^*	125.5^**	110.2^*	126.7^**
SW480	92.4^*	100.0	134.6^**	129.4^**	105.8 NS	144.2^**
MDA MB468	84.1^**	100.0	117.8^*	118.8^*	108.9^*	133.7^***
MCF-7	92.5^*	100.0	108.6 NS	115.1^*	104.3 NS	123.3^**
PC3	97.3 NS	100.0	104.3 NS	106.6^*	102.7 NS	107.0 NS
T24	95.3 NS	100.0	106.8 NS	93.8 NS	109.0 NS	107.5^*
(b) Average migratory activity (%)
HT29	1.3	7.4	16.9	18.9	12.9	27.9
SW480	2.7	12.6	18.4	16.2	15.8	26.0
MDA MB468	6.8	9.6	14.4	17.4	12.3	24.6
MCF-7	5.5	18.8	23.5	19.2	24.0	29.4
PC3	12.2	12.0	17.3	16.3	17.9	37.5
T24	15.3	29.0	46.8	26.5	28.0	52.3
(C) Distance migrated (μm)
HT29	7.8	12.4	15.6	18.4	17.7	16.0
SW480	3.5	10.5	16.1	19.8	17.8	29.2
MDA MB468	8.6	17.8	32.8	27.0	35.5	57.5
MCF-7	2.4	7.6	8.2	7.3	10.8	14.1
PC3	10.9	12.6	16.9	15.9	13.0	15.4
T24	18.8	26.1	48.7	20.7	25.8	51.8

Abbreviation: NS=not significant.
^*P>0.05; ^**P>0.01; ^***P>0.001.
(A) End point determination of tumour cell proliferation after cultivation at either 5.5 mM glucose, 11 mM glucose or 11 mM glucose plus 100 ng ml⁻¹ insulin. (1E5 cells per sample were seeded and cultured for 1 week). All samples are compared with the physiological glucose concentration of 5.5 mM (100%). (B) Comparison of the average migratory activity of tumour cell lines revealed increased activity with increased glucose levels (2.75 mM<5.5 mM<11 mM), but also differences between the cell lines with regard to the ability to further increase activity at very high glucose concentrations (22 mM). (C) 3D-migration assays revealed up to three-fold increase in distance migrated (e.g. MDA MB468) cells were treated with high glucose (5.5 mM vs 11 mM) and insulin (100 ng ml⁻¹) concentrations. The table show mean values of three independent experiments (90 cells were analyzed per sample). Statistical comparison between specified values was made either by two-tailed unpaired t-test.

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