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The antiandrogenic activity of 5-fluorouracil
555
THE ANTIANDROGENIC ACTIVITY OF !+FLUOROURACIL Ralph I. Dorfman Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts
ReceivedOctober 11, 1963 ABSTRACT 5-Fluorouracil is a highly effective antiandrogen in the testosterone stimulated castrated mouse assay. on a weight basis, it is about 10 to 20 times more active than progesterone. This antitumor agent was inactive as an antiestrogen in the estrone stimulated immature mouse test using uterine weight as the endpoint. Paschkis et a1.l and Xagerman and Cantarow2 demonstrated that testosterone induced growth of the seminal vesicles in the castrated rat may be inhibited by 5-fluorouracil.
The
inhibition produced by this compound could be overcome by increasing the dosage of androgens to 100 mg per day2.
The
antiandrogenic activity of 5-fluorouracil has now been extended to a test system employing the testosterone stimulated castrated mouse. METHODS The antiandrogen method used in this study has been published3 and involves the use of the castrated immature mouse stimulated with a total dose of 0.8 mg of testosterone dissolved in sesame oil and injected subcutaneously once daily for 7 days.
5-Fluorouracil, varying in total dose frcm
STEROIDS
556
25
0.1 to 1.6 mg, was suspended in an aqueous suspending medium consisting of sodium chloride carboxymethylcellulose
(0.9%), polysorbate 80 (0.4x),
(0.5%) and benzyl alcohol (0.9%) and
was injected subcutaneously once daily for 7 days.
Twenty-four
hours after the last injection, the mice were sacrificed and body, ventral prostate, and seminal vesicle weights were determined.
The tissue responses are recorded as the ratio
of milligrams of tissue per gram of body weight. The antiestrogenic activity of 5-fluorouracil was evaluated by a method previously described by Dorfman et a1.4 which employs the estrone stimulated twenty to twenty-two day old Swiss Albino mouse with the test compound being administered simultaneously and at another site.
Autopsy was performed
one day after the last injection, and the results expressed as the ratio of mg of uterine weight per gram of body weight. PEZULTS AND CONCLUSIONS Table 1 presents the antiandrogenic activity of 5-fluorouracil as compared to that of progesterone.
In experi-
ment I, progesterone at 40 mg produced a highly significant inhibition of the activity of testosterone and 5-fluorouracil at a total dose of 0.8 mg was similarly effective on the seminal vesicle only. was toxic.
At the 1.6 mg dose level, 5-fluorouracil
Progesterone was included as a positive control.
Nov.
1963
STEROIDS
557
TABLE 1 EFFECT OF 5-FLUOROURACIL ON TESTOSTERONE INDUCED GROWTH OF TEE CASTRATED MOUSE ACCESSORIES Total Dose of
TEST COMPOUND Total Dose mg
ExP. No. Designation 0
1
0 Progesterone S-Fluorouracil II
0 0 5-Fluorouracil Progesterone
III
0 0 Progesterone
5-Fluorouracil
XV
0 0 Progesterone 5-Fluorouracil
TeStOS-
terone mg
0
0
0 40 0.8 1.6 0 0 0.4 0.8 10 20 0 0 5 10 20 0.1 0.2 0.4 0.8 0 0 2.5 20 0.2 0.8
0.8 0.8 0.8 0.8 0 0.8 0.8 0.8 0.8 0.8 0 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0 0.8 0.8 0.8 0.8 0.8
Mean Body No.of Wt. Mice g 10 19 10 19 10 17 6 17 ALLDEAD 9 17 9 16 8 17 8 16 4 14 10 15 10 15 10 17 10 21 8 18 9 16 8 16 6 16 9 16 11 18 10 17 8 21 10 18 7 15 10 17 9 19
TISSUE RATIO + S-E. Seminal ventral Prostate Vesicles 0.14kO.01 0.22kO.01 0.22f0.02 0.87kO.08 0.12+0.02 0.38+0.05 0.19-r-0.02 0.69kO.06 0.05t0.01 0*15-f0.01 0.23rtO.02 1.13-fO.09 0.16kO.02 0.73k0.10 0.18ttO.02 O-73+0.07 0.21kO.03 1.01*0,23 O.lSrt-0.02 O-74+0.12 0.07+0.01 0.14rto.01 0.20-+0.02 1.25-+0.12 0.19+0*01 l.Olf0.05 0.22kO.19 0.91-cO.08 0.291tO.03 0,66-+0.07 0.25kO.29 1.11~0.13 0.26-eO.17 1.12-e0.16 0.2XkO.17 1.05-fO.08 0.22kO.12 l.Off0.12 0.12f0.01 0.29-+0.04 0.22+0.02 l-5620.28 0.18f0.02 0.95+0.08 0.19-+0,02 0.693-0.07 0.24kO.01 O-96*0,10 0.22rto.02 0.88kO.08
As seen by the summary in Table 2, progesterone was effective in each of four trials at total doses of 20 and 40 mg.
A
comparison of the relative potency of 5-fluorouracil and progesterone
indicates that the antitumor agent is some 10 to
2:5
STEROIDS
558
20 times more active as an antiandrogen on a weight basis. In spite of the rather striking antiandrogenic effect of 5-fluorouracil, this antitumor agent did not produce any convincing antiestrogenic effects at total doses up to 640 pg. TABLE 2 SUMMARY OF ANTIANDROGENIC ACTIVITY OF PROGESTERONE AND 5-FLUOROURACIL ON THE BASIS OF SEMINAL VESICLE END-POINT
Compound Progesterone
5-Fluorouracil
Total Dose m9 2.5 5 10 20 40
Number Of Trials Positive Negative
0.1 0.2 0.4 0.8
1 1 1 3 1
0 0 1 0 0
0 1 1 4
1 1 1 0
TABLE 3 LACK OF EFFECT OF 5-FLUOROURACIL ON ESTROGEN INDUCED GROWTH IN TBE IMMATURE MOUSE UTERUS Estrone Total DOSe Of 0 0 10 40 160 640
Total
Dose
NO. Of
0 0.4 0.4 0.4 0.4 0.4
11 12 11 11 12 12
Mean Uterine Ratio rf: S.E. 1.12 + 0.03 6.29 + 0.22 5.37 + 0.25 5.98 k 0.38 5.99 + 0.35 5.47 + 0.30
Nov. 1963
STEROIDS
559
ACKNOWLEDGMENTS supported in part by U. S. Public Health Service Grant CA-02193
REFERENCES 1. 2. 3. 4.
Paschkis, K. E., Bartuska, D., Zagerman, J., Goddard, J. w -> and Cantarow, A., CANCER RESEARCH 19, 1196 (1959). Zagerman, J., Cantarow, A., CANCER CHEMOTHERAPY REPORTS 22, 37 (1962). Dorfman, R. I., PROC. SOC. EXPTL. BIOL. MED. 111, 441 (1962). Dorfman, R. I., METHODS IN HORMONE RESEARCH, edited by R. I. Dorfman, Academic Press, New York, 1962, volume II, p. 113.
THE ANTIANDROGENIC ACTIVITY OF !+FLUOROURACIL Ralph I. Dorfman Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts
ReceivedOctober 11, 1963 ABSTRACT 5-Fluorouracil is a highly effective antiandrogen in the testosterone stimulated castrated mouse assay. on a weight basis, it is about 10 to 20 times more active than progesterone. This antitumor agent was inactive as an antiestrogen in the estrone stimulated immature mouse test using uterine weight as the endpoint. Paschkis et a1.l and Xagerman and Cantarow2 demonstrated that testosterone induced growth of the seminal vesicles in the castrated rat may be inhibited by 5-fluorouracil.
The
inhibition produced by this compound could be overcome by increasing the dosage of androgens to 100 mg per day2.
The
antiandrogenic activity of 5-fluorouracil has now been extended to a test system employing the testosterone stimulated castrated mouse. METHODS The antiandrogen method used in this study has been published3 and involves the use of the castrated immature mouse stimulated with a total dose of 0.8 mg of testosterone dissolved in sesame oil and injected subcutaneously once daily for 7 days.
5-Fluorouracil, varying in total dose frcm
STEROIDS
556
25
0.1 to 1.6 mg, was suspended in an aqueous suspending medium consisting of sodium chloride carboxymethylcellulose
(0.9%), polysorbate 80 (0.4x),
(0.5%) and benzyl alcohol (0.9%) and
was injected subcutaneously once daily for 7 days.
Twenty-four
hours after the last injection, the mice were sacrificed and body, ventral prostate, and seminal vesicle weights were determined.
The tissue responses are recorded as the ratio
of milligrams of tissue per gram of body weight. The antiestrogenic activity of 5-fluorouracil was evaluated by a method previously described by Dorfman et a1.4 which employs the estrone stimulated twenty to twenty-two day old Swiss Albino mouse with the test compound being administered simultaneously and at another site.
Autopsy was performed
one day after the last injection, and the results expressed as the ratio of mg of uterine weight per gram of body weight. PEZULTS AND CONCLUSIONS Table 1 presents the antiandrogenic activity of 5-fluorouracil as compared to that of progesterone.
In experi-
ment I, progesterone at 40 mg produced a highly significant inhibition of the activity of testosterone and 5-fluorouracil at a total dose of 0.8 mg was similarly effective on the seminal vesicle only. was toxic.
At the 1.6 mg dose level, 5-fluorouracil
Progesterone was included as a positive control.
Nov.
1963
STEROIDS
557
TABLE 1 EFFECT OF 5-FLUOROURACIL ON TESTOSTERONE INDUCED GROWTH OF TEE CASTRATED MOUSE ACCESSORIES Total Dose of
TEST COMPOUND Total Dose mg
ExP. No. Designation 0
1
0 Progesterone S-Fluorouracil II
0 0 5-Fluorouracil Progesterone
III
0 0 Progesterone
5-Fluorouracil
XV
0 0 Progesterone 5-Fluorouracil
TeStOS-
terone mg
0
0
0 40 0.8 1.6 0 0 0.4 0.8 10 20 0 0 5 10 20 0.1 0.2 0.4 0.8 0 0 2.5 20 0.2 0.8
0.8 0.8 0.8 0.8 0 0.8 0.8 0.8 0.8 0.8 0 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0 0.8 0.8 0.8 0.8 0.8
Mean Body No.of Wt. Mice g 10 19 10 19 10 17 6 17 ALLDEAD 9 17 9 16 8 17 8 16 4 14 10 15 10 15 10 17 10 21 8 18 9 16 8 16 6 16 9 16 11 18 10 17 8 21 10 18 7 15 10 17 9 19
TISSUE RATIO + S-E. Seminal ventral Prostate Vesicles 0.14kO.01 0.22kO.01 0.22f0.02 0.87kO.08 0.12+0.02 0.38+0.05 0.19-r-0.02 0.69kO.06 0.05t0.01 0*15-f0.01 0.23rtO.02 1.13-fO.09 0.16kO.02 0.73k0.10 0.18ttO.02 O-73+0.07 0.21kO.03 1.01*0,23 O.lSrt-0.02 O-74+0.12 0.07+0.01 0.14rto.01 0.20-+0.02 1.25-+0.12 0.19+0*01 l.Olf0.05 0.22kO.19 0.91-cO.08 0.291tO.03 0,66-+0.07 0.25kO.29 1.11~0.13 0.26-eO.17 1.12-e0.16 0.2XkO.17 1.05-fO.08 0.22kO.12 l.Off0.12 0.12f0.01 0.29-+0.04 0.22+0.02 l-5620.28 0.18f0.02 0.95+0.08 0.19-+0,02 0.693-0.07 0.24kO.01 O-96*0,10 0.22rto.02 0.88kO.08
As seen by the summary in Table 2, progesterone was effective in each of four trials at total doses of 20 and 40 mg.
A
comparison of the relative potency of 5-fluorouracil and progesterone
indicates that the antitumor agent is some 10 to
2:5
STEROIDS
558
20 times more active as an antiandrogen on a weight basis. In spite of the rather striking antiandrogenic effect of 5-fluorouracil, this antitumor agent did not produce any convincing antiestrogenic effects at total doses up to 640 pg. TABLE 2 SUMMARY OF ANTIANDROGENIC ACTIVITY OF PROGESTERONE AND 5-FLUOROURACIL ON THE BASIS OF SEMINAL VESICLE END-POINT
Compound Progesterone
5-Fluorouracil
Total Dose m9 2.5 5 10 20 40
Number Of Trials Positive Negative
0.1 0.2 0.4 0.8
1 1 1 3 1
0 0 1 0 0
0 1 1 4
1 1 1 0
TABLE 3 LACK OF EFFECT OF 5-FLUOROURACIL ON ESTROGEN INDUCED GROWTH IN TBE IMMATURE MOUSE UTERUS Estrone Total DOSe Of 0 0 10 40 160 640
Total
Dose
NO. Of
0 0.4 0.4 0.4 0.4 0.4
11 12 11 11 12 12
Mean Uterine Ratio rf: S.E. 1.12 + 0.03 6.29 + 0.22 5.37 + 0.25 5.98 k 0.38 5.99 + 0.35 5.47 + 0.30
Nov. 1963
STEROIDS
559
ACKNOWLEDGMENTS supported in part by U. S. Public Health Service Grant CA-02193
REFERENCES 1. 2. 3. 4.
Paschkis, K. E., Bartuska, D., Zagerman, J., Goddard, J. w -> and Cantarow, A., CANCER RESEARCH 19, 1196 (1959). Zagerman, J., Cantarow, A., CANCER CHEMOTHERAPY REPORTS 22, 37 (1962). Dorfman, R. I., PROC. SOC. EXPTL. BIOL. MED. 111, 441 (1962). Dorfman, R. I., METHODS IN HORMONE RESEARCH, edited by R. I. Dorfman, Academic Press, New York, 1962, volume II, p. 113.