Opportunities and challenges of long term anti-estrogenic adjuvant therapy: treatment forever or intermittently?

The crucial role of epigenetic regulation in breast cancer anti-estrogen resistance: Current findings and future perspectives

Breast cancer (BC) cell de-sensitization to Tamoxifen (TAM) or other selective estrogen receptor (ER) modulators (SERM) is a complex process associated with BC heterogeneity and the transformation of ER signalling. The most influential resistance-related mechanisms include modifications in ER expression and gene regulation patterns. During TAM/SERM treatment, epigenetic mechanisms can effectively silence ER expression and facilitate the development of endocrine resistance. ER status is efficiently regulated by specific epigenetic tools including hypermethylation of CpG islands within ER promoters, increased histone deacetylase activity in the ER promoter, and/or translational repression by miRNAs. Over-methylation of the ER α gene (ESR1) promoter by DNA methyltransferases was associated with poor prognosis and indicated the development of resistance. Moreover, BC progression and spreading were marked by transformed chromatin remodelling, post-translational histone modifications, and expression of specific miRNAs and/or long non-coding RNAs. Therefore, targeted inhibition of histone acetyltransferases (e.g. MYST3), deacetylases (e.g. HDAC1), and/or demethylases (e.g. lysine-specific demethylase LSD1) was shown to recover and increase BC sensitivity to anti-estrogens. Indicated as a powerful molecular instrument, the administration of epigenetic drugs can regain ER expression along with the activation of tumour suppressor genes, which can in turn prevent selection of resistant cells and cancer stem cell survival. This review examines recent advances in the epigenetic regulation of endocrine drug resistance and evaluates novel anti-resistance strategies. Underlying molecular mechanisms of epigenetic regulation will be discussed, emphasising the utilization of epigenetic enzymes and their inhibitors to re-program irresponsive BCs.

Novel Strategies on Personalized Medicine for Breast Cancer Treatment: An Update

Breast cancer is the most common cancer type among women worldwide. With breast cancer patients and survivors being reported to experience a repertoire of symptoms that are detrimental to their quality of life, the development of breast cancer treatment strategies that are effective with minimal side effects is therefore required. Personalized medicine, the treatment process that is tailored to the individual needs of each patient, is recently gaining increasing attention for its prospect in the development of effective cancer treatment regimens. Indeed, recent studies have identified a number of genes and molecules that may be used as biomarkers for predicting drug response and severity of common cancer-associated symptoms. These would provide useful clues not only for the determination of the optimal drug choice/dosage to be used in personalized treatment, but also for the identification of gene or molecular targets for the development of novel symptom management strategies, which ultimately would lead to the development of more personalized therapies for effective cancer treatment. In this article, recent studies that would provide potential new options for personalized therapies for breast cancer patients and survivors are reviewed. We suggest novel strategies, including the optimization of drug choice/dosage and the identification of genetic changes that are associated with cancer symptom occurrence and severity, which may help in enhancing the effectiveness and acceptability of the currently available cancer therapies.

A brief discussion of aspects in breast cancer research, science mentorship and the workplace culture today

Balkees Abderrahman speaks to Roshaine Wijayatunga, managing commissioning editor: Balkees Abderrahman is a Fellow of Breast Medical Oncology at MD Anderson Cancer Center and a Fellow of the Royal Society of Medicine of Great Britain. She is a PhD trainee under model “Applicants of Very High Quality” at the Faculty of Medicine, The University of Leeds, West Yorkshire, Great Britain. She works with Professor V Craig Jordan, OBE, FMedSci. Dr. Abderrahman is the author of “Steroid Receptors in Breast Cancer, The Breast: Comprehensive Management of Benign and Malignant Diseases 2017”, “Hormones and Cancer, Oxford Textbook of Cancer Biology 2018”, “First Targeted Therapy – History of Tamoxifen, Estrogen Receptor and Breast Cancer, Cancer Drug Discovery and Development, Springer Nature 2018” and “Selective Estrogen Receptor Modulators (SERMs), Estrogen Receptor and Breast Cancer, Cancer Drug Discovery and Development, Springer Nature 2018”. She has published several articles in breast cancer research. She is also the author of “Love at the Gate” and “Oliver and the Rock” and a contributor at Nature, the Pharmaceutical Journal of the Royal Pharmaceutical Society of Great Britain, The Independent, The American Society of Clinical Oncology (ASCO) Post, The Huffington Post, US News and World Report, The Hill and The Nation. She was a finalist for the Outstanding Youth Award at the United Nations from over 86 countries for “Her outstanding work in tackling some of our greatest social, economic, and environmental challenges”.