Transformation Potential of E2 Exposed Breast Cancer Susceptibility Gene Mutation Heterozygous Epithelial Breast Cells

July 24, 2013 updated by: Asher Salmon, Hadassah Medical Organization

Identification of the Transformation Potential of Normal Estrogen Exposed BRCA1 (Breast Cancer Susceptibility Gene 1) and BRCA2 (Breast Cancer Susceptibility Gene 2) Heterozygous Epithelial Breast Cells Due to Irradiation

Susceptibility to breast cancer is related to the combination of genetic, hormonal and multiple other environmental risk factors, such as mutations in the BRCA gene and excess exposure to exogenous estrogen, respectively. BRCA is a nuclear protein that maintains genome stability, by acting as a key player in the DNA repair complex. Recently, evidence has emerged that BRCA mutation heterozygosis itself enhances aborted DNA repair and can contribute to breast cancer initiation after exposure to irradiation. In our preliminary results on short-term lymphocyte cultures, we found additional evidence that healthy heterozygous BRCA1 and BRCA2 mutation carriers have a different response to DNA damage than do non-carriers.

The main aim of our ongoing project is to identify the transcriptional modulation and transformation potential of normal BRCA1 and BRCA2 mutation heterozygous epithelial breast cells following irradiation and to examine how it is affected by exposure to estrogen. Our hypotheses will be investigated by RNA-seq and microRNA-seq in order to identify a unique molecular expression profile of the estrogen exposed cells following ionizing irradiation.

Understanding the role of BRCA heterozygosity in cell response to exposure to estrogen and to irradiation may facilitate the development of more appropriate diagnostic and therapeutic strategies for these individuals.

Study Overview

Status

Unknown

Conditions

Detailed Description

To study the different cell lineages, we plan to isolate and propagate luminal progenitors from a normal human breast tissue. To this end, 10 human breast tissue samples will be obtained from risk-reducing mastectomy in healthy premenopausal women with BRCA1 mutations. Tissues from 10 premenopausal women undergoing esthetic breast surgery with no family history of breast or ovarian cancers will serve as a control group. In order to isolate primary epithelial cells, human mammary tissue will be minced and enzymatically digested overnight in collagenase and hyaluronidase to yield suspension of epithelial organoids. These organoids will be collected and further digested with trypsin, dispase and deoxyribonuclease 1 (DNAse), will be filtered to generate a single cell suspension, resuspended in Hank's + 2% fetal bovine serum (FBS) and 0.1 mg/mL DNAse, and also incubated with a blocking antibody for 15 minutes on ice.

Cells will be treated with estrogen (E2) (10 nM) for 48 h and then will be irradiated for inducing double-strand break. Cells will be irradiated with 8 Gray (Gy) using a Co60 source.

To accomplish our study, estrogen exposed and unexposed BRCA mutation heterozygous epithelial breast cells will be irradiated and 1 h later RNA will be extracted from the cells using Tri-reagent (Sigma). The RNA will be converted to a library of cDNA (complementary DNA) fragments and will be sent for deep sequencing in the illumina Hi-Seq platform.

Study Type

Observational

Enrollment (Anticipated)

30

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

25 years to 50 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

human breast tissue samples will be obtained from risk-reducing mastectomy in healthy premenopausal women with BRCA1 and BRCA2 mutations. Tissues from premenopausal women undergoing esthetic breast surgery with no family history of breast or ovarian cancers also will be obtained.

Description

Inclusion Criteria:

  • healthy
  • premenopausal
  • women
  • BRCA1 mutations
  • BRCA2 mutations

Exclusion Criteria:

  • women with breast or ovarian cancer

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
non-carriers
Tissues from premenopausal women undergoing esthetic breast surgery with no family history of breast or ovarian cancers will be obtained.epithelial breast cells will be isolated, treated with estrogen for 48 h and then will be irradiated.
BRCA1 mutation carriers
Tissues from risk-reducing mastectomy in healthy premenopausal women with BRCA1 mutations undergoing.epithelial breast cells will be isolated, treated with estrogen for 48 h and then will be irradiated.
BRCA2 mutation carriers
Tissues from risk-reducing mastectomy in healthy premenopausal women with BRCA2 mutations undergoing.epithelial breast cells will be isolated, treated with estrogen for 48 h and then will be irradiated.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The transcriptional profile of heterozygous epithelial breast cells
Time Frame: human breast tissue samples will be obtained from premenopausal women undergoing breast surgery. cells will be isolated immediatly and 48h later the transcriptional profile will be identified.
we will perform a RNA-seq expression profiling analysis of normal estrogen exposed BRCA heterozygous epithelial cells following irradiation.
human breast tissue samples will be obtained from premenopausal women undergoing breast surgery. cells will be isolated immediatly and 48h later the transcriptional profile will be identified.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hadassah Medical Organization

Investigators

  • Principal Investigator: Asher Y Salmon, MD, PhD, Hadassah Medical Organization

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2013

Primary Completion (ANTICIPATED)

September 1, 2014

Study Completion (ANTICIPATED)

September 1, 2015

Study Registration Dates

First Submitted

July 22, 2013

First Submitted That Met QC Criteria

July 24, 2013

First Posted (ESTIMATE)

July 25, 2013

Study Record Updates

Last Update Posted (ESTIMATE)

July 25, 2013

Last Update Submitted That Met QC Criteria

July 24, 2013

Last Verified

July 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ISF-1702/12

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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