# The Function of EGFL6 in Ovarian Cancer Cell Biology, Tumor Initiation, and Therapy

> **NIH NIH R01** · MAGEE-WOMEN'S RES INST AND FOUNDATION · 2021 · $343,538

## Abstract

ABSTRACT: Ovarian cancer is a deadly disease with the 3rd-highest mortality:incidence ratio of all cancers.
High-grade serous cancer (HGSC) is the most aggressive ovarian cancer subtype for which we have seen only
little or no improvement in patient survival. Thus there is a clear unmet need to identify and develop new
therapeutic targets in HGSC. We recently showed that the stem cell regulatory factor EGFL6 is a critical
regulator of ALDH+ HGSC cancer stem-like cells (CSC), cells associated with therapeutic resistance. EGFL6
promotes the migration and asymmetric division of ALDH+HGSC CSC, while EGFL6 knockdown in HGSC
cancer cells leads to loss of stemness and dramatically reduced tumor growth in mice. We therefore
hypothesize that EGFL6 is a promising therapeutic target for HGSC. Understanding the therapeutic potential
EGFL6-directed agents will require greater understanding of EGFL6's roles in ovarian cancer cell biology. The
EGFL6 receptor on cancer cells is unknown. As disruption of ligand/receptor signaling has proven a very
effective therapeutic mechanism in other pathways, we propose SA1: To Identify the EGFL6 receptor and
characterize the EGFL6 signaling complex. In addition to regulating HGSC CSC, EGFL6 is an important
regulator of normal stem cells. Mutated normal stem cells are a proposed source of cancer initiating cells. We
hypothesize EGFL6 as a regulator of both normal stem cells and HGSC CSC may be essential for ovarian
cancer initiation and growth. We therefore propose SA2: To evaluate the role of EGFL6 in cancer initiation.
We will use a novel genetic mouse model of HGSC to assess (i) the impact of EGFL6 knockout or (ii) the effect
of EGFL6 neutralizing antibodies on HGSC initiation and growth. We have shown that the murine EGFL6
neutralizing antibody we developed has excellent therapeutic activity versus human cancer cell lines in mice.
To translate these studies into clinical trials we developed a a panel of humanized EGFL6-blocking antibodies
(hEGFL6-Ab). We propose SA3: To validate hEGFL6-Ab and determine if EGFL6 expression by patients'
tumors predicts response to anti-EGFL6 therapy. Using in vitro assays and a novel humanized stroma-
patient derived xenograft model we will identify the most effective hEGFL6-Ab. We hypothesize that patients
whose tumor cells express EGFL6 and/or exhibit EGFL6 pathway activation will be most responsive to such
therapy. Using expression analysis of hEGFL6-Ab responsive and non-responsive tumors, we propose to
generate an algorithm to predict patients' responses to anti-EGFL6 therapy.
IMPACT: These studies will 1) define the EGFL6 signaling cascade in ovarian cancer cells, 2) define
requirements for cancer cell EGFL6 expression in HGSC initiation and growth, and 3) create and validate a
novel humanized anti-EGFL6-Ab and an accompanying algorithm that identifies/stratifies patients who are
most apt to respond to such therapy. Ultimately, the project will produce a promising therapeutic agent
p...

## Key facts

- **NIH application ID:** 10061581
- **Project number:** 5R01CA218026-03
- **Recipient organization:** MAGEE-WOMEN'S RES INST AND FOUNDATION
- **Principal Investigator:** Ronald J Buckanovich
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $343,538
- **Award type:** 5
- **Project period:** 2018-12-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10061581

## Citation

> US National Institutes of Health, RePORTER application 10061581, The Function of EGFL6 in Ovarian Cancer Cell Biology, Tumor Initiation, and Therapy (5R01CA218026-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10061581. Licensed CC0.

---

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