The Breasties stage 4 research
with Magee-Womens Research Institute
support the breasties stage 4 research fund
history
2019
2021 /2022
In 2021 The Breasties decide to expand their mission to include funding a $50k grant to fund stage 4 metastatic breast cancer.
In true Breastie fashion, we wanted our community to feel a part of the entire process.
We tapped into Breastie expert Laila Roudsari – the Director of Cell Biology in the Regenerative Medicine lab at United Therapeutics, overseeing Cell Isolation, Research, and Process Development teams – to help as well.
Together we decided to partner with Magee on our first research grant, awarding them $50,000 to fund Estrogen Receptor mutations in resistance to hormonal therapies. The major goal of the project is to determine how mutations in the estrogen receptor (ER) cause resistance to hormonal therapies, including tamoxifen and aromatase inhibitors, and metastases.
The Breasties Progress Report
Grant Term: July 1, 2022 – June 30, 2023
Interim Progress Report Period: July 1, 2022 – January 31, 2023
Steffi Oesterreich, PhD
Research Question
Estrogen Receptor mutations in resistance to hormonal therapies. The major goal of the project is to determine how mutations in the estrogen receptor (ER) cause resistance to hormonal therapies, including tamoxifen and aromatase inhibitors, and metastases.
As a brief background, approx. 70 percent of all breast tumors express ER and patients with ER-positive breast tumors receive hormonal therapies. And of those, depending on tumor size, lymph node involvement and the molecular make-up of the tumor, approx. 20 percent will suffer a recurrence, and once the tumor recurs as endocrine resistant disease in a distant organ, like liver, lung, brain, bone etc., the disease can no longer be cured. Over the last 10 years, a number of groups including ours, have shown that mutations in the target of hormonal therapies (i.e., ER) cause endocrine resistance in 30-40 percent of tumors.
These mutations include the change of single base pairs in the gene or translocation of parts of the gene to other genes on other chromosomes (causing so-called “fusion genes”).
during the first part of the funding period, we have focused on:
Generation and characterization of ER mutant models
a) Patient-derived organoids (PDO)We were able to expand our collection of PDOs, (i.e., 3D cultures of breast tumors) collected directly from surgery (in close collaboration with our surgeons). We have expanded those and confirmed ER mutation status with very sensitive and quantitative methods.
b) Syngeneic modelsThere is increasing interest in the role of the immune system in tumor development and progression. It is challenging to study immune cell infiltration in dishes in the lab, and a common model is the mouse, but we cannot use human models injected into mice as they will be rejected. We have therefore spent some time and effort in the generation of mouse breast cancer models with wildtype and mutant ER.
Characterization of ER mutant metastases
We have started to characterize phenotypes of our ER mutant models such as breast cancer cell lines with some interesting ER fusion genes. The cells move more in the dishes and have higher motility. We will expand these studies over the next few months.We are also currently determining which metastatic samples from our Rapid Autopsy program have ER mutations, and once finished, we will do additional sequencing studies on these metastatic samples. Of note, the rapid autopsy program was recently renamed into the “Hope for OTHERS” program based on interaction with breast cancer advocates.
In addition, Dr. Oesterreich was honored to participate in The Breasties Instagram LIVE on October 10, 2022. She enjoyed this interaction very much.
2023
Dr. Steffi presented to The Breastie community at Camp Breastie in June. Here is the most current progress report:
The Breasties Progress report August 2023
(the grant is in No Cost Extension, NCE)
Steffi Oesterreich, PhD
As a brief background, approx. 70% of all breast tumor express ER and patients with ER-positive breast tumors receive hormonal therapies. And of those, depending on tumor size, lymph node involvement and also molecular make-up of the tumor, approx. 20% will suffer a recurrence, and once the tumor recurs as endocrine resistant disease in a distant organ, like liver, lung, brain, bone etc, the disease cannot be cured anylonger. Over the last 10 years, a number of groups including ours have shown that mutations in the target of hormonal therapies ie ER cause endocrine resistance in 30-40% of tumors.
These mutations include change of single base pairs in the gene or translocation of parts of the gene to other genes on other chromosomes (causing so-called “fusion genes”).
During the last six months, we have continued to generate additional models representing breast tumors with ER mutations seen in patients, and also to characterize ER mutant metastases.
Generation and characterization of ER mutant models
We continued the studies which were started at the beginning of the funding proposal, namely, to generate additional patient-derived organoids (PDOs) from samples with wildtype (“normal”) and mutant ER. We attempted to characterize expression of ER in these PDOs, and did run into technical problems. We were unable to use common techniques like immunohistochemistry to stain for ER, and we are still troubleshooting. It is likely that the unique growth condition, including the media in which the PDOs are cultured, interferes with the staining.
Nevertheless, we have confirmed responses to estrogen and anti-estrogen in these PDOs by measuring expression of RNA of ER and its targets. We now have in hand some models that faithfully represent breast tumors harboring ER mutations. Since these PDOs are limited to the tumor cells, and don’t contain immune cells, we have also expanded our work on the generation of mouse breast cancer cells with ER mutations that can then be injected and grown in mice where the tumors will be infiltrated withimmune cells from the mice. We have successfully generated five cell line models and have confirmed increased activity of ER mutation in these cells. We are currently generating 3 additional models (representing 3 other ER mutations), and the next step will be to characterize those. Once this has been completed, the next goal will be to understand growth, metastases, and immune infiltration in the mice(the latter would be outside the scope of the current proposal).
Characterization of ER mutant metastases
We have identified metastatic lesions from our “Hope for OTHERS” (aka Rapid Autopsy) program which have ER mutations. The next step will be to isolate RNA from these samples, and perform detailed molecular characterization. We will use the BREASTIES funds to start these studies, and the preliminary results will be used to apply for additional funding (since the planned sequencing studies are very expensive).IN SUMMARY, we have made significant progress towards our goal to generate and characterize models to study estrogen receptor mutant breast cancer. This is of high clinical relevance since ER mutations are the major cause of death in patients with breast cancer.
In addition, I was honored to participate and present in the BREASTIES Camp June 1st- June 2nd 2023 where I shared our research progress on the project, as well as other ongoing breast cancer research efforts. This was a unique experience which I enjoyed very much, and I hope to have contributed a tiny bit to the success of this event. And of course, we were delighted to host Trish Michelle and Bri Majsiak in Pittsburgh for the 34th Magee Survivorship Celebration & Workshop, and show them our breast cancer research labs.
— Dr. Oesterreich
Trish and Bri were the keynote speakers at the 34th Magee Survivorship Celebration.