22 Jul Beyond Tamoxifen: How (Z)-Endoxifen May Transform ER+ Breast Cancer Treatment — and Offer New Hope in Duchenne Muscular Dystrophy
MedicalResearch.com Interview with:
Steven Quay, MD, PhD
Founder, Chairman of the Board and Chief Executive Officer
Atossa Therapeutics
Publications discussed: The rise of selective estrogen receptor modulators (SERMs) in breast cancer therapy: a promising horizon and (Z)-Endoxifen as a Potential Modulator of Utrophin Pathways in Duchenne Muscular Dystrophy: A Mechanistic and Transcriptomic Perspective
[caption id="attachment_75169" align="alignleft" width="240"]
Dr. Steven C. Quay[/caption]
MedicalResearch.com: What is the background for these studies? What are the main findings of the reviews?
Dr. Quay: Breast cancer remains the most common cancer diagnosis and the second leading cause of cancer death among women in the United States. Around 70% of these cases are estrogen receptor-positive (ER+), meaning the tumor cells use the body's natural estrogen as fuel to multiply and grow. While traditional endocrine therapies like tamoxifen have saved countless lives, patients frequently face severe side effects or eventually develop resistance to the treatment.
To bridge this gap, these studies show the promise of next-generation selective estrogen receptor modulators (SERMs), specifically (Z)-endoxifen. The main findings indicate that this active-form drug delivers more consistent, well-tolerated exposure to keep pace with a patient's unique biology. We are looking at the whole picture — from cancer prevention in high-risk patients to shrinking tumors before cases worsen. Ultimately, this approach builds on tamoxifen's legacy and blocks estrogen signaling to provide patients with more effective therapy options. For context on risk factors in breast cancer prevention, see this overview of breast cancer risk and dense breast tissue.
Prof. Ruth Shemer[/caption]
MedicalResearch.com: What types of cells were used in the study, ie keratinocytes, muscle cells etc?
Response: The primary tissue used in this study was peripheral blood from over 300 healthy human donors (18-78 years old). To further understand how the methylation changes are associated with changes in blood cell composition, we also sorted immune cell types including neutrophils, monocytes, B cells, and T cells. For forensics applications, we also tested the clock on urine and saliva samples.
[caption id="attachment_69522" align="alignleft" width="125"]
Prof. Yuval Dor[/caption]
MedicalResearch.com: Does this study relate at all to telomere length?Response:
Response: No, this study does not investigate or reference telomere length. It focuses entirely on DNA methylation changes at few genomics regions, each covering multiple clustered DNA methylation sites, where methylation changes are indicative of chronological age, independently of telomere biology.
MedicalResearch.com: What are the main findings?
Response: - A single-molecule analysis using DNA sequencing, revealed that
Shani Vaknine[/caption]
Shani Vaknine, Ph.D. candidate
Brain and Behavioral Sciences
The Hebrew University
MedicalResearch.com: What is the background for this study?
Response: We’ve long known that maternal stress during pregnancy can affect her baby’s development, but the molecular mechanisms behind this remained unclear. In our study, we explored how psychosocial stress experienced by the mother in late pregnancy influences tiny molecular fragments in the newborn’s blood. These fragments, called transfer RNA fragments or tRFs, were considered for many years to be disposable, but have recently been shown to have important biological functions.
Dr. Moyland[/caption]
Cynthia Moylan, MD
Associate Professor of Medicine,
Division of Gastroenterology
Duke University Health System
MedicalResearch.com: What is the background for this study?
Response: Metabolic dysfunction can lead to several health problems including metabolic dysfunction associated steatotic liver disease (MASLD), is driven by different factors, including: a person’s behavioral or lifestyle factors, environmental factors, and genetics. Limited research exists regarding genetic , epigenetic, or other factors that might impact development of metabolic dysfunction and MASLD. Our group has previously shown that alterations in DNA methylation (a type of epigenetic change), identifiable both in liver tissue and in blood, associate with MASLD and its progression to more severe liver disease. Whether DNA methylation that impacts imprinted gene expression also associates with metabolic dysfunction and MASLD risk remains largely unknown.
In this project, we explored imprinted genes: imprinting is a normal process that regulates genes by silencing one parental copy (either the maternal or the paternal) so that only one copy is expressed. Imprinting is an important biological process for development and has a disproportionate impact on disease - in fact, imprinted genes are hypothesized to affect 1-6% of the human genome. We sought to explore how altered DNA methylation of imprint control regions (ICRs) that help ‘control’ these imprinted genes might impact development of metabolic dysfunction in children (and hence potentially even in adults).
Dr. Zeynep Gümüş[/caption]
Zeynep H. Gümüş, PhD
Associate Professor
Icahn School of Medicine at Mount Sinai
MedicalResearch.com: What is the background for this study?
Response: The germline genome of each individual person has a unique combination of millions of genetic variants that influence virtually all biological processes throughout life, including cancer evolution. In this study, we have investigated the impact of germline variants – genetic defects one is born with – on gene expression and protein abundance in tumors across cancer types.
MedicalResearch.com: Would you describe the technique of precision peptidomics?
Response: We have leveraged a cohort of 1,064 patients with multiple cancer types to explore the impact of germline variations on cancer-relevant genes through multiple-omics layers: from DNA to RNA, protein abundance and post-translational modifications. To assess the effects of coding variants and their association with cognate proteins, we used precision peptidomics, which is the quantification of peptides carrying genetic variants from individual patients. Through this approach, we mapped 337,469 protein coding germline variants onto patient peptides, revealing their potential impact on protein modifications, protein stability, allele-specific expression, and protein structure by leveraging the relevant protein databases.
Prof. Michaelides[/caption]
Professor Michel Michaelides BSc MB BS MD(Res) FRCOphth FACS
Professor of Ophthalmology and Consultant Ophthalmic Surgeon
UCL Institute of Ophthalmology and Moorfields Eye Hospital
MedicalResearch.com: What is the background for this study?
Dr. Yu Mengge[/caption]
Dr Yu Mengge
Research Fellow, Cancer & Stem Cell Biology Signature Research Programme
Duke-NUS Medical School
MedicalResearch.com: What is the background for this study?
Response: The background of this study is rooted in the observation that certain genetic variations among East Asian populations, notably the BIM deletion polymorphism (BDP), impact treatment outcomes in chronic myeloid leukaemia (CML).
Patients with the BDP show resistance to conventional treatments, specifically tyrosine kinase inhibitors like imatinib. This resistance stems from the variant's role in promoting cancer cell survival, which leads to more aggressive disease progression.
Dr. Nas[/caption]
Dr Zeynep Nas Ph.D.
Postdoctoral Research Fellow
Department of Behavioural Science and Health
Institute of Epidemiology & Health Care
University College London
MedicalResearch.com: What is the background for this study?
Response: We were interested in why some children are more selective in their food intake and more reluctant to try new foods compared to those who are not. We investigated this question in a twin study, which compares identical twins (who share all of their genes) to non-identical twins (who share half) to understand the relative influence of genetics versus the environment in shaping individual differences in fussy eating.
Dr. Walsh[/caption]
Christopher Walsh, M.D., Ph.D.
Chief, Division of Genetics and Genomics
Bullard Professor of Pediatrics and Neurology at Harvard Medical School
and researcher who has used material donated to the brain bank
MedicalResearch.com: What is the background for this study?
Response: Many different types of genetic variants contribute to neurodevelopmental disorders such as autism. Copy number variants are large pieces of genetic material that are duplicated or deleted. We have known for many years that many copy number variants at certain genetic locations are linked to autism. Because these copy number variants may include lots of different genes, it has been difficult to understand how these copy number variants alter human brain function. Furthermore, although animal models are important, autism is in many ways defined by differences in uniquely human cognitive and social functioning. Better understanding of how these copy number variants change human brain function will shed light on universal mechanisms that regulate neurodevelopment. We studied a copy number variant called dup15q, that is associated with almost 40-fold higher rates of autism vs. the general population. We studied post-mortem human brain tissue from individuals with dup15q, individuals with autism not related to dup15q, and neurotypical controls, to better understand how the human brain is impacted by dup15q. We focused on frontal cortex, an important brain region in executive function and social perspective taking. We applied cutting edge techniques that allow us to assess individual cells in the brain.
Ben Petrazzini[/caption]
Ben Omega Petrazzini, B.Sc.
Associate Bioinformatician
Dr. Patel[/caption]
Rima Patel, MD
Assistant Professor, Division of Hematology/Oncology
The Tisch Cancer Institute
Icahn School of Medicine at Mount Sinai
MedicalResearch.com: What is the background for this study?
Response: The 21-gene Oncotype DX Recurrence Score (RS) and 70-gene MammaPrint (MP) assays provide prognostic information for distant recurrence and are used to guide chemotherapy use in hormone receptor (HR)-positive, HER2-negative early breast cancer (EBC). Previous reports have demonstrated racial differences in the prognostic accuracy of the RS. In both the TAILORx and RxPONDER trials, Black women with low genomic risk (RS 0-25) had a higher recurrence risk than White women. In another study using the NCDB database,