# INHIBITORY EFFECT OF MOLYBDATE ON MAMMARY CARCINOGENESIS

> **NIH NIH R01** · TEXAS TECH UNIVERSITY · 1987 · $93,201

## Abstract

We have recently demonstrated, for the first time, molybdenum (Mo)
supplementation significantly reduce the incidences of chemically induced
esophageal and mammary cancers in rats, and tungsten (W) supplementation to
counter the effect of Mo.  The addition of Mo also significantly prolonged
the estrous cycle.  Our present plan is to attempt to elucidate the
mechanism involved in the inhibitory effect of Mo on mammary carcinogenesis.

Three animal experiments are designed.  The first experiment is to
determine the effect of graded levels of Mo supplementation on mammary
carcinogenesis, while the second experiment is to investigate the timing of
Mo supplementation on the inhibition of mammary carcinogenesis, and the
third, the influence of dietary fat on the inhibitory effect of Mo on
mammary carcinogenesis.  Female weanling inbred Sprague-Dawley rats will be
fed ad libitum for 30 weeks a nutritionally adequate semipurified (AIN-76)
diet containing 0.026ppm Mo and 0.064 ppm W, and demineralized drinking
water without or with Mo supplementation.  At 50 days of age, animals will
receive a single subcutaneous injection of 5 mg N-nitroso-N-methylurea
(NMU)/100 g body weight.  Four animals randomly selected from each
experimental group will be transferred into individual metabolism cages for
a 24-hour urine collection immediately prior to the initiation of the
experiment, 24 hours after the NMU treatment and at weeks 7, 9, 11 and 30
of the experimental period.  Immediately after the completion of urine
collection, the animals will be sacrificed for the determination of (1)
Mo-containing enzyme activities in liver, mammary gland and other tissues,
(2) uric acid and other purine metabolites in plasma and urine, (3)
metabolites associated with sulfite oxidase activity in plasma and urine,
and (4) histopathological changes of mammary gland and other tissues.
Emphasis will also be directed toward the effect of Mo supplementation on
hormones and their receptors.  For this, animals will be treated with the
most optimal level and timing of Mo supplementation established in the
above experiments.  The timings of the carcinogen treatment and sacrifice
will be adjusted individually so that the animals will be at the same stage
of the estrous cycle.  Plasma hormone contents and hormone receptors in the
cytosol of mammary gland will be assayed.

## Key facts

- **NIH application ID:** 3178365
- **Project number:** 5R01CA039418-03
- **Recipient organization:** TEXAS TECH UNIVERSITY
- **SAM.gov UEI:** EGLKRQ5JBCZ7
- **Principal Investigator:** SHIANG P YANG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $93,201
- **Award type:** 5
- **Project period:** 1985-09-01 → 1988-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3178365

## Citation

> US National Institutes of Health, RePORTER application 3178365, INHIBITORY EFFECT OF MOLYBDATE ON MAMMARY CARCINOGENESIS (5R01CA039418-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3178365. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*