# MONOCLONAL ANTIBODIES TO MAMMARY TUMOR GROWTH FACTORS

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON · 1987 · $29,244

## Abstract

We have proposed previously that estrogens promote mammary tumor cell
growth in vivo via induction of a new group of mediator growth factors
tentatively designated estromedins.  These mitogenic polypeptides are
either endocrine factors that are produced in one target tissue (under
estrogen control), secreted into plasma and act on distant target cells, or
instead, are locally acting autocrine (autostimulatory) forms that are
released and act in the target tissue in response to estrogen stimulation.

In ongoing studies of the endocrine mechanism, we have purified mg amounts
of three new mammary tumor cell growth factors from sheep uterus, mature
ewe kidney and whole sheep pituitaries.  These activities are all acetic
acid and heat stable peptides of Mr = 3,900 to 4,200 and are shown to be
distinct by biochemical and biological analyses.

In parallel studies, we have shown that the MTW9/PL rat mammary tumor cells
in culture possess an estradiol inducible, acetic acid and heat stable
autostimulatory factor (Mr = 4,200) that we have partially purified in mg
amounts from these tumors growing in W/Fu rats.  Complete purification of
this autocrine activity is now in progress using new HPLC methods.

In this application we propose to define the role of these growth factors
in estrogen responsive and autonomous mammary tumor growth.  The specific
aims are (1) to determine the conditions for raising monoclonal antibodies
to the purified growth factors using in vitro immunization methods, (2) to
determine whether the growth factors are immunologically distinguishable,
(3) to determine whether the antibodies to the endocrine forms of
estromedins are able to inhibit mammary estrogen responsive and/or
autonomous mammary tumor cell growth in W/Fu rats, and finally (4) to
better define the role of autocrine (autostimulatory) factors in conversion
of estrogen-responsive growth to autonomy.

It is our working hypothesis that estrogen-responsive mammary tumor growth
is dependent upon endocrine and autocrine factors, whereas, autonomous
tumor growth requires only autocrine factors.  The studies proposed are
aimed at establishing whether antigrowth factor monoclonal antibodies are
effective therapeutic agents for mammary tumors.

## Key facts

- **NIH application ID:** 3176011
- **Project number:** 3R01CA038024-03S1
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
- **SAM.gov UEI:** ZUFBNVZ587D4
- **Principal Investigator:** DAVID A SIRBASKU
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $29,244
- **Award type:** 3
- **Project period:** 1984-08-01 → 1988-03-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3176011

## Citation

> US National Institutes of Health, RePORTER application 3176011, MONOCLONAL ANTIBODIES TO MAMMARY TUMOR GROWTH FACTORS (3R01CA038024-03S1). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3176011. Licensed CC0.

---

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