# CALCIUM AND CELL CYCLE CONTROL IN HUMAN FIBROBLASTS

> **NIH NIH R01** · SYRACUSE UNIVERSITY AT SYRACUSE · 1987 · $51,796

## Abstract

Substantial evidence exists indicating that the ability of certain growth
factors and hormones to regulate cell proliferation may depend on a
synergistic interaction with extracellular and/or plasma membrane-bound
Ca2+ and that this relationship may be modified in transformed cells.
Transformed cells exhibit reduced growth factor or serum requirements and a
reduced requirement for extracellular Ca2+.  Ca2+ appears to modulate
either serum or EGF requirements for fibroblasts and epithelial cells, and
recent reports indicate Ca2+ requirements for EGF, NGF, and insulin
binding and/or internalization and degradation.

We have demonstrated a Ca2+ requirement in early and late G1 phase for
human and mouse fibroblasts, and this has been confirmed by others in rat
fibroblasts.  The absence of Ca2+ at either of these positions in G1
phase prevents GO-early G1 exit and late G1 to S phase entrance.  We now
will investigate these Ca2+ requirements in regard to recent evidence
dealing with growth factor-hormone (GFH) regulation of G1 progression and
rate of entry to S phase.  These two processes are conceivably regulated at
the same time specific Ca2+ requirements have been identified in the G1
phase.  We shall evaluate the changes in Ca2+ transport and
compartmentation during G1 phase and their sensitivity to various GFH
treatments using isotope flux techniques.  We shall evaluate the ability of
GFH to alter the lag phase versus rate of entry to S phase and establish
whether such effects relate to Ca2+ metabolism.  We shall evaluate the
relationship of GFH to the regulation of four membrane transport systems,
which we have demonstrated to be regulated by serum and Ca2+.  We shall
evaluate Ca2+ metabolism and its regulation by various GFHs during G1
phase in the transformed fibroblast.  This should be possible due to our
recent ability to syn-chronize SV40-transformed cells.  Essentially no
information is available regarding these processes in transformed cells.
Lastly, we shall examine effects of serum growth conditions versus defined
media growth conditions on Ca2+ metabolism, since recent reports indicate
that ionic metabolism may well differ under the two growth states.  (N)

## Key facts

- **NIH application ID:** 3174356
- **Project number:** 5R01CA036784-04
- **Recipient organization:** SYRACUSE UNIVERSITY AT SYRACUSE
- **Principal Investigator:** JOSEPH T TUPPER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $51,796
- **Award type:** 5
- **Project period:** 1984-04-01 → 1988-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3174356

## Citation

> US National Institutes of Health, RePORTER application 3174356, CALCIUM AND CELL CYCLE CONTROL IN HUMAN FIBROBLASTS (5R01CA036784-04). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3174356. Licensed CC0.

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