Table 2 TEC-1 did not induce micronucleus formation in TK9 cells with or without a rat liver microsome fraction (S9).

From: Discovery of a CNS penetrant small molecule SMN2 splicing modulator with improved tolerability for spinal muscular atrophy

Group

Test article

Concentration

µg/mL

Treatment conditions

Relative population doubling (%)

Micronucleated cells

Well 1

Well 2

Total

(%)

1

DMSO

10 μL/mL

3 h -S9 mix

100

13

13

26

(0.65)

2

TEC-1

1.9 (4.9 µM)

68.6

13

16

29

(0.73)

3

 

2.1 (5.4 µM)

65.4

16

20

36

(0.9)

4

 

2.3 (5.9 µM)

35.0

29

27

56

(1.4) **,##

5

MMC

0.1 (0.3 µM)

N.D.

59

59

118

(2.95) **

6

DMSO

10 μL/mL

3 h + S9 mix

100

10

14

24

(0.6)

7

TEC-1

2.5 (6.4 µM)

76.4

18

15

33

(0.83)

8

 

2.7 (6.9 µM)

58.7

24

21

45

(1.13) **

9

 

2.9 (7.4 µM)

46.8

17

13

30

(0.75)

10

CP

6 (21 µM)

N.D.

39

46

85

(2.13) **

11

DMSO

10 μL/mL

24 h -S9 mix

100

18

12

30

(0.75)

12

TEC-1

1.1 (2.8 µM)

81.7

21

13

34

(0.85)

13

 

1.3 (3.3 µM)

74.4

17

12

29

(0.73)

14

 

1.5 (3.9 µM)

69.5

17

15

32

(0.8)

15

COL

0.01 (0.03 µM)

N.D.

45

51

96

(2.4) **

  1. Experiments were performed under the following three treatment conditions. 1: short-term treatment for 3 h without S9 mix, followed by a 21-h culture (3 h −S9 mix, shown in groups 1–5), 2: short-term treatment for 3 h with S9 mix, followed by 21-h culture (3 h + S9 mix, shown in groups 6–10), 3: continuous treatment for 24 h without S9 mix (24 h −S9 mix, shown in group 11–15). Mitomycin (MMC) for 3 h −S9 mix, cyclophosphamide (CP) for 3 h + S9 mix, and colcemid (COL) for 24 h −S9 mix were used as positive controls. These articles have been recommended for use in the OECD test guideline (Test No. 487)49. DMSO was served as negative control. The numbers of micronucleated cells were counted in 4000 cells and percentages of micronucleated cells were calculated for statistical analyses. ## < 0.01 as assessed by Cochran-Armitage test for dose-relationship. **p < 0.01 as assessed by Fisher’s exact test using negative control-treated cells. N.D. indicates Not Determined.