# A CYTOPLASMIC ROLE IN CARCINOGEN-INDUCED TUMORIGENICITY

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 1988 · $172,443

## Abstract

We have made NIH/3T3 cells tumorigenic by treatment with the ultimate
carcinogen of benzo(a)pyrene, namely r-7,
t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydro-benzo(a)-pyrene (anti-BPDE)
and passaging in culture.  Using these cells and mouse embryo fibroblasts
(MEF) we propose to examine by somatic cell genetic approaches (1)
suppression of tumorigenicity by fusion of cytoplasts of MEF or untreated
NIH/3T3 cells to karyoplasts of BPDE-treated NIH/3T3 cells; (2) suppression
of tumorigenicity of potentially transformed cells by fusion of cytoplasts
of MEF or NIH/3T3 cells to karyoplasts of BPDE-NIH/3T3 cells which are not
tumorigenic at passage 5; (3) induction of immortality of MEF by fusion of
their karyoplasts to cytoplasts of BPDE-treated NIH/3T3 cells; and (4)
induction of tumorigenicity by fusing cytoplasts derived BPDE-treated
NIH/3T3 cells to karyoplasts of untreated NIH/3T3 cells.

We have chosen to work with BPDE since it binds to mitochondrial DNA with a
50-100 times greater affinity than to nuclear DNA and produces tumors in
rats and mice.  Because many tumor cells have altered mitochondrial
function, we will examine mitochondrial DNA for BPDE-induced mutations.
Since it has been shown that BPDE introduces a specific mutation in the
ras-Hal oncogene at codons 11 and 12 leading to a loss of an Mspl
restriction site, we will initially analyze for loss of an Mspl restriction
site in mitochondrial DNA obtained from BPDE-induced tumorigenic cells.  To
increase the probability of detection of such a mutation, mitochondrial DNA
from tumorigenic BPDE-treated NIH/3T3 cells and nontumorigenic NIH/3T3
cells will be cloned.  By examining which of the mitochondrial DNA eleven
Mspl sites have been eliminated, we will be able to pinpoint the mutated
gene(s).

## Key facts

- **NIH application ID:** 3179526
- **Project number:** 5R01CA040065-03
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **SAM.gov UEI:** YZJ6DKPM4W63
- **Principal Investigator:** Jerry William Shay
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $172,443
- **Award type:** 5
- **Project period:** 1986-05-01 → 1990-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3179526

## Citation

> US National Institutes of Health, RePORTER application 3179526, A CYTOPLASMIC ROLE IN CARCINOGEN-INDUCED TUMORIGENICITY (5R01CA040065-03). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3179526. Licensed CC0.

---

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