scholarly journals Targeting mTOR and Glycolysis in HER2-Positive Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2922
Author(s):  
Ryan W. Holloway ◽  
Paola A. Marignani
Keyword(s):  
Breast Cancer ◽  
Treatment Strategies ◽  
Mtor Pathway ◽  
Breast Cancers ◽  
Her2 Receptor ◽  
Her2 Positive ◽  
Risk Of Recurrence ◽  
Her2 Positive Breast Cancer ◽  
Positive Breast Cancer

Up to one third of all breast cancers are classified as the aggressive HER2-positive subtype, which is associated with a higher risk of recurrence compared to HER2-negative breast cancers. The HER2 hyperactivity associated with this subtype drives tumor growth by up-regulation of mechanistic target of rapamycin (mTOR) pathway activity and a metabolic shift to glycolysis. Although inhibitors targeting the HER2 receptor have been successful in treating HER2-positive breast cancer, anti-HER2 therapy is associated with a high risk of recurrence and drug resistance due to stimulation of the PI3K-Akt-mTOR signaling pathway and glycolysis. Combination therapies against HER2 with inhibition of mTOR improve clinical outcomes compared to HER2 inhibition alone. Here, we review the role of the HER2 receptor, mTOR pathway, and glycolysis in HER2-positive breast cancer, along with signaling mechanisms and the efficacy of treatment strategies of HER2-positive breast cancer.

scholarly journals The HER2 Receptor in Breast Cancer: Pathophysiology, Clinical Use, and New Advances in Therapy

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Zahi Mitri ◽  
Tina Constantine ◽  
Ruth O'Regan
Keyword(s):  
Breast Cancer ◽  
Cardiac Myocyte ◽  
Early Stage ◽  
Standard Of Care ◽  
Breast Cancers ◽  
Trastuzumab Resistance ◽  
Her2 Receptor ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Positive Breast Cancer

Human epidermal growth factor receptor 2 (HER2) is overexpressed in around 20–30% of breast cancer tumors. It is associated with a more aggressive disease, higher recurrence rate, and increased mortality. Trastuzumab is a HER2 receptor blocker that has become the standard of care for the treatment of HER2 positive breast cancer. The effectiveness of Trastuzumab has been well validated in research as well as in clinical practice. The addition of Trastuzumab to standard of care chemotherapy in clinical trials has been shown to improve outcomes for early stage as well as metastatic HER2 positive breast cancer. The most clinically significant side effect of Trastuzumab is the risk of cardiac myocyte injury, leading to the development of congestive heart failure. The emergence of patterns of resistance to Trastuzumab has led to the discovery of new monoclonal antibodies and other targeted agents aimed at overcoming Trastuzumab resistance and improving survival in patients diagnosed with HER2 positive breast cancers.

scholarly journals Linc01638 Promotes Tumorigenesis in HER2+ Breast Cancer

2018 ◽  
Vol 19 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Peng Liu ◽  
Hailin Tang ◽  
Jiali Wu ◽  
Xingsheng Qiu ◽  
Yanan Kong ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Apoptosis ◽  
Breast Cancer Cells ◽  
Her2 Positive ◽  
Mouse Xenograft ◽  
Her2 Positive Breast Cancer ◽  
Mouse Xenograft Model ◽  
Positive Breast Cancer

Background: Long non-coding RNAs play crucial roles in various biological activities and diseases. The role of long intergenic non-coding RNA01638 (linc01638) in breast cancer, especially in HER2-positive breast cancer, remains largely unknown. Objective: To investigate the effect of linc01638 on tumorigenesis in HER2-positive breast cancer. </P><P> Methods: We first used qRT-PCR to detect linc01638 expression in HER2-positive breast cancer cells and tissues. Then we analyzed the effects of linc01638 expression in HER2-positive breast cancer cells through cell apoptosis assay, cell proliferation assay, colony formation assay, and cell invasion assay. We conducted mouse xenograft model to further confirm the role of linc01638 in HER2-positive breast cancer. Moreover, we used Western blot and IHC analysis to access the effect of linc01638 on DNMTs, BRCA1 and PTEN expressions in transplanted tumors. Results: Linc01638 was found to be remarkably overexpressed in HER2-positive breast cancer cells and tissues. Suppression of linc01638 enhanced cell apoptosis, as well as inhibited the growth and invasiveness of HER2-positive breast cancer cells in vitro and tumor progression and metastasis in vivo. Furthermore, inhibition of linc01638 by shRNA attenuated expression of DNMT1, DNMT3a, and DNMT3b, and promoted expression of BRCA1 and PTEN in HER2-positive breast cancer cells and mouse xenograft models. Linc01638 might be a promising biomarker and therapeutic target for treatment of HER2-positive breast cancer.

Influence of Anthropometric Characteristics in Patients With Her2-Positive Breast Cancer on Initial Plasma Concentrations of Trastuzumab

2017 ◽  
Vol 51 (11) ◽  
pp. 976-980 ◽  
Author(s):  
Jonathan González García ◽  
Fernando Gutiérrez Nicolás ◽  
Gloria Julia Nazco Casariego ◽  
José Norberto Batista López ◽  
Isaac Ceballos Lenza ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Standard Dose ◽  
Plasma Concentrations ◽  
Breast Cancers ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Initial Plasma ◽  
Anthropometric Characteristics ◽  
Secondary Objective ◽  
Positive Breast Cancer

Background: Plasma concentrations of trastuzumab <20 µg/mL in patients with gastric cancer are associated with reduced progression-free and overall survival. In breast cancer treatment, this relationship has not yet been studied, but a suboptimal pharmacodynamic exposure to trastuzumab could be a reason for therapeutic failure of treatment of HER2-positive breast cancer. Objective: The objective of the present study was to determine the proportion of nonmetastatic HER2-positive breast cancers that do not reach a minimum plasma concentration ( Cmin) of 20 µg/mL after first drug administration, established as therapeutically effective in clinical trials. The secondary objective was to identify the physiological and anthropometric characteristics that determine interindividual pharmacokinetic variability. Methods: Serum concentrations of trastuzumab were assessed by ELISA on day 1 of the second cycle before administration of the second dose ( Cmin). Results: Of 19 patients included, 9 (47.4%) had a mean Cmin of 19.0 µg/mL (±12.1) after the first administration. Body mass index (BMI) and weight was the main variable that determined the achievement of therapeutic levels after the first administration. Thus, the proportion of patients reaching the target concentration was 89% when BMI was ≤30 kg/m2 but only 11% when BMI was >30 kg/m2 ( P < 0.01). Conclusions: The standard dose of 600 mg subcutaneous trastuzumab did not ensure adequate pharmacodynamic exposure from the first administration in 52% of patients, with weight and BMI being related to the plasma levels obtained.

The role of TP53 pathogenic variants in early-onset HER2-positive breast cancer

2020 ◽  
Author(s):  
Carla Escudeiro ◽  
Carla Pinto ◽  
Joana Vieira ◽  
Ana Peixoto ◽  
Pedro Pinto ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Early Onset ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Pathogenic Variants ◽  
Positive Breast Cancer

scholarly journals Epigenetic downregulation of HER2 during EMT leads to tumor resistance to HER2-targeted therapies in breast cancer

2020 ◽  
Author(s):  
Babak Nami ◽  
Avrin Ghanaeian ◽  
Zhixiang Wang
Keyword(s):  
Breast Cancer ◽  
Tyrosine Kinase ◽  
Gene Silencing ◽  
Receptor Tyrosine Kinase ◽  
Breast Cancer Cells ◽  
Breast Cancers ◽  
Her2 Expression ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Positive Breast Cancer

ABSTRACTHER2 receptor tyrosine kinase (encoded by ERBB2 gene) is overexpressed in approximately 25% of all breast cancer tumors (known as HER2-positive breast cancers). Overexpression of HER2 causes overactivation of downstream receptor tyrosine kinase pathways including PI3K/Akt and MAPK pathways and is a poor prognosis factor in breast cancer. Tyrosine kinase inhibitor lapatinib and anti-HER2 monoclonal antibodies trastuzumab and pertuzumab are FDA-approved HER2-targeted drugs for treatment of HER2-positive breast cancers. However, development of de novo resistance to HER2 blockade occurs in majority of patients after treatment started. Resistance to HER2 targeting therapies partially due to the loss of HER2 expression on their tumor cells during the treatment. But little is known about the exact mechanism of loss of HER2 on originally HER2-positive tumor cells. Downregulation of extracellular HER2 by metalloproteinases during epithelial-mesenchymal transition (EMT) in trastuzumab-resistant/lapatinib-sensitive cells has been shown by limited studies, however, the mechanism of ERBB2 gene silencing during EMT and in the mesenchymal-like cells derived from trastuzumab-resistant/lapatinib-resistant HER2-positive breast tumors was entirely unknown. In this study, hypothesized that EMT abrogates HER2 expression by chromatin-based epigenetic silencing of ERBB2 gene as a mechanism of acquired resistance to HER2-targeted therapies. we found that HER2 expression is positively and negatively correlated with the expression of epithelial and mesenchymal phenotype marker genes respectively in breast cancer tumors. We also found that chromatin of ERBB2 gene in HER2-high epithelial-like breast cancer cells is active, while, the chromatin is inactive in HER2-low mesenchymal-like cells. HER2-low breast cancer cell line also revealed less promoter-enhancer interaction and small chromatin loops compared to the HER2-high cell lines. The lower HER2 expression, the higher EMT phenotype, and inactivated chromatin all were found correlated with a lower response to lapatinib. The higher EMT phenotype was found correlated with a lower response to lapatinib. We also found that induction of EMT of HER2-positive breast cancer BT474 cells results in downregulated HER2 expression and lower binding rate of trastuzumab to the cells. These results show that the downregulation of HER2 in mesenchymal-like cells in the culture of HER2-positive breast cancer cell lines was due to ERBB2 gene silencing by epigenetic reprogramming of the cells during EMT. These results indicate that ERBB2 gene silencing by epigenetic regulation during EMT is the main mechanism of resistance of HER2-positive breast cancer cells to trastuzumab and lapatinib.

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