scholarly journals Letrozole Accelerates Metabolic Remodeling through Activation of Glycolysis in Cardiomyocytes: A Role beyond Hormone Regulation

2022 ◽  
Vol 23 (1) ◽  
pp. 547
Author(s):  
Jun H. Heo ◽  
Sang R. Lee ◽  
Seong Lae Jo ◽  
Hyun Yang ◽  
Hye Won Lee ◽  
...  

Estrogen receptor-positive (ER+) breast cancer patients are recommended hormone therapy as a primary adjuvant treatment after surgery. Aromatase inhibitors (AIs) are widely administered to ER+ breast cancer patients as estrogen blockers; however, their safety remains controversial. The use of letrozole, an AI, has been reported to cause adverse cardiovascular effects. We aimed to elucidate the effects of letrozole on the cardiovascular system. Female rats exposed to letrozole for four weeks showed metabolic changes, i.e., decreased fatty acid oxidation, increased glycolysis, and hypertrophy in the left ventricle. Although lipid oxidation yields more ATP than carbohydrate metabolism, the latter predominates in the heart under pathological conditions. Reduced lipid metabolism is attributed to reduced β-oxidation due to low circulating estrogen levels. In letrozole-treated rats, glycolysis levels were found to be increased in the heart. Furthermore, the levels of glycolytic enzymes were increased (in a high glucose medium) and the glycolytic rate was increased in vitro (H9c2 cells); the same was not true in the case of estrogen treatment. Reduced lipid metabolism and increased glycolysis can lower energy supply to the heart, resulting in predisposition to heart failure. These data suggest that a letrozole-induced cardiac metabolic remodeling, i.e., a shift from β-oxidation to glycolysis, may induce cardiac structural remodeling.

2021 ◽  
pp. 1-10
Author(s):  
Yu Wang ◽  
Han Zhao ◽  
Ping Zhao ◽  
Xingang Wang

BACKGROUND: Pyruvate kinase M2 (PKM2) was overexpressed in many cancers, and high PKM2 expression was related with poor prognosis and chemoresistance. OBJECTIVE: We investigated the expression of PKM2 in breast cancer and analyzed the relation of PKM2 expression with chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated whether PKM2 could reverse chemoresistance in breast cancer cells in vitro and in vivo. METHODS: Immunohistochemistry (IHC) was performed in 130 surgical resected breast cancer tissues. 78 core needle biopsies were collected from breast cancer patients before neoadjuvant chemotherapy. The relation of PKM2 expression and multi-drug resistance to NAC was compared. The effect of PKM2 silencing or overexpression on Doxorubicin (DOX) sensitivity in the MCF-7 cells in vitro and in vivo was compared. RESULTS: PKM2 was intensively expressed in breast cancer tissues compared to adjacent normal tissues. In addition, high expression of PKM2 was associated with poor prognosis in breast cancer patients. The NAC patients with high PKM2 expression had short survival. PKM2 was an independent prognostic predictor for surgical resected breast cancer and NAC patients. High PKM2 expression was correlated with neoadjuvant treatment resistance. High PKM2 expression significantly distinguished chemoresistant patients from chemosensitive patients. In vitro and in vivo knockdown of PKM2 expression decreases the resistance to DOX in breast cancer cells in vitro and tumors in vivo. CONCLUSION: PKM2 expression was associated with chemoresistance of breast cancers, and could be used to predict the chemosensitivity. Furthermore, targeting PKM2 could reverse chemoresistance, which provides an effective treatment methods for patients with breast cancer.


Oncogene ◽  
2021 ◽  
Author(s):  
Francesco Pantano ◽  
Martine Croset ◽  
Keltouma Driouch ◽  
Natalia Bednarz-Knoll ◽  
Michele Iuliani ◽  
...  

AbstractBone metastasis remains a major cause of mortality and morbidity in breast cancer. Therefore, there is an urgent need to better select high-risk patients in order to adapt patient’s treatment and prevent bone recurrence. Here, we found that integrin alpha5 (ITGA5) was highly expressed in bone metastases, compared to lung, liver, or brain metastases. High ITGA5 expression in primary tumors correlated with the presence of disseminated tumor cells in bone marrow aspirates from early stage breast cancer patients (n = 268; p = 0.039). ITGA5 was also predictive of poor bone metastasis-free survival in two separate clinical data sets (n = 855, HR = 1.36, p = 0.018 and n = 427, HR = 1.62, p = 0.024). This prognostic value remained significant in multivariate analysis (p = 0.028). Experimentally, ITGA5 silencing impaired tumor cell adhesion to fibronectin, migration, and survival. ITGA5 silencing also reduced tumor cell colonization of the bone marrow and formation of osteolytic lesions in vivo. Conversely, ITGA5 overexpression promoted bone metastasis. Pharmacological inhibition of ITGA5 with humanized monoclonal antibody M200 (volociximab) recapitulated inhibitory effects of ITGA5 silencing on tumor cell functions in vitro and tumor cell colonization of the bone marrow in vivo. M200 also markedly reduced tumor outgrowth in experimental models of bone metastasis or tumorigenesis, and blunted cancer-associated bone destruction. ITGA5 was not only expressed by tumor cells but also osteoclasts. In this respect, M200 decreased human osteoclast-mediated bone resorption in vitro. Overall, this study identifies ITGA5 as a mediator of breast-to-bone metastasis and raises the possibility that volociximab/M200 could be repurposed for the treatment of ITGA5-positive breast cancer patients with bone metastases.


Blood ◽  
1993 ◽  
Vol 82 (9) ◽  
pp. 2605-2610 ◽  
Author(s):  
AA Ross ◽  
BW Cooper ◽  
HM Lazarus ◽  
W Mackay ◽  
TJ Moss ◽  
...  

Abstract Although peripheral blood stem cell collections (PBSC) are thought to have less tumor involvement than bone marrow (BM), the incidence of circulating tumor cells in patients with breast cancer has not been widely investigated. We prospectively investigated the incidence and viability of tumor cell involvement in PBSC and BM collections from breast cancer patients undergoing high-dose chemotherapy/hematopoietic stem cell transplantation. Paired samples of PBSC and BM from 48 patients were analyzed using an immunocytochemical technique that detects one epithelial-derived tumor cell per 5 x 10(5) mononuclear cells. Immunostained tumor cells were detected in 9.8% (13/133) PBSC specimens from 9/48 (18.7%) patients and in 62.3% (38/61) BM specimens from 32/48 (66.7%) patients, a significantly higher rate than in PBSC (P < .005). The geometric mean concentration of tumor cells in contaminated PBSC specimens was 0.8/10(5) mononuclear cells (range 0.33 to 2.0/10(5)) compared with 22.9/10(5) mononuclear cells in BM (range 1 to 3,000/10(5), P < .0001). In culture experiments, clonogenic tumor colonies grew in 21/26 immunocytochemically positive specimens. No tumor colony growth was detected in 30/32 immunocytochemically negative specimens. Immunocytochemical detection of tumor involvement in BM and PBSC correlated significantly with in vitro clonogenic growth (P < .0001). We conclude that PBSC contain fewer tumor cells than paired BM specimens from patients with advanced breast cancer and that these tumor cells appear to be capable of clonogenic growth in vitro.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2505-2505 ◽  
Author(s):  
L. Fan ◽  
J. Y. Guo ◽  
C. I. Wong ◽  
R. Lim ◽  
H. L. Yap ◽  
...  

2505 Background: Human carbonyl reductase 3 (CBR3) is one of the main metabolizing enzymes to extensively reduce doxorubicin to its major active metabolite, doxorubicinol in normal and tumor tissues. Recently, the CBR3 958G>A (V244M) genetic variant has been described to alter function in vitro. We postulate that CBR3 genetic variants could contribute to the inter-individual variability of doxorubicin pharmacokinetics in breast cancer patients. Methods: We studied 101 female breast cancer patients (66 Chinese, 26 Malay, 7 Indian and 2 of other ethnic origins) who were treated with doxorubicin at 75mg/m2 every 3 weeks. Comprehensive sequencing of the 3 exons of CBR3, including the splice-site junctions was performed. Plasma concentrations of doxorubicin and doxorubicinol were analyzed during the first doxorubicin cycle. Results: Five CBR3 coding region variants (239G>A, 483C>T, 507C>T, 598G>A and 958G>A) were detected, of which 239G>A, 598G>A and 958G>A were non-synonymous. 598G>A was novel, and was found in 1 Malay patient who was heterozygous. The genotype distributions of 239G>A and 958G>A were 36%/30%/34%, and 40%/36%/24% respectively for GG/AG/AA. The 239GG variant was associated with significantly higher AUC of doxorubicinol and AUC ratio of doxorubicinol to doxorubicin than the AG and AA variants (AUC of doxorubicinol 2.18±1.37ug/ml*h (GG) vs 2.04±2.11ug/ml*h (AG), p=0.05, and 1.55±0.61ug/ml*h (AA), p=0.004; AUC ratio of doxorubicinol to doxorubicin 1.90±1.29 (GG) vs 1.72±1.34 (AG), p=0.025, and 1.45±0.67 (AA), p=0.006). Patients with the 958AA variant had significantly higher AUC of doxorubicinol than those with the 958GG variant (2.29±1.60ug/ml*h vs 1.56±0.60ug/ml*h, p=0.009). The 239GG variant was more common in our population than in Caucasians (36% vs 20%. p=0.027), while the 958AA variant was more common than reported in Caucasians (24% vs 8%, p=0.014) and Japanese (24% vs 7%, p=0.016). Conclusions: CBR3 genetic variants may influence the pharmacokinetics of doxorubicin and its major metabolite doxorubicinol. Inter-ethnic differences in frequencies of CBR3 genetic variants exist and may account for differences in pharmacokinetics and pharmacodynamics of doxorubicin between different populations. No significant financial relationships to disclose.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3096-3096
Author(s):  
Ritesh Patil ◽  
Guy T. Clifton ◽  
Jennifer Keating Litton ◽  
Nathan M. Shumway ◽  
Timothy J Vreeland ◽  
...  

3096 Background: GP2 is a 9 amino acid HLA-A2/A3 restricted HER2-derived peptide. GP2 + GM-CSF has been shown to be safe and effective in eliciting anti-HER2 immune response in breast cancer patients. Preclinical data has demonstrated that pretreatment of cells with trastuzumab (Tz) enhances susceptibility to lysis by GP2-specific cytotoxic T lymphocytes (CTLs). We conducted a phase Ib study to evaluate the combination of the GP2 vaccine and Tz. Methods: HLA-A2/A3 + patients with HER2 overexpressing breast cancer receiving Tz as standard therapy were enrolled. The study was designed as a 3+3 dose escalation trial with an expansion cohort evaluating 4 dose levels of the vaccine administered as 6 inoculations given every 3 weeks in combination with Tz (6mg/kg). Toxicity was graded 48-72 hr post vaccination using NCI Toxicity Criteria. Ejection fraction (EF) was monitored every 3 mo. Immunologic response was assessed in vivo by injection site local reaction (LR) and in vitro by quantifying the number of GP2-specific CTLs by HLA-A2: IgG dimer assays and their functional activity by ELISPOT. Results: 19 patients enrolled (median age 47 yr, mean tumor size 3.4 cm, 74% were grade 3, 53% ER/PR+, 63% node positive, 74% received anthracycline based therapy). Maximum local toxicities were grade 1 (77% of patients) and grade 2 (6%), and maximum systemic toxicities were grade 1 (24%) and grade 2 (5%). There were no grade 3 or 4 local or systemic toxicities. There was no significant change in EF at 3 mo (57± 1%, p=0.23) or 6 mo (59±1%, p=0.8) compared to baseline (58±0.9%). Mean post-vaccine series LR was significantly larger than initial vaccination LR (68.2 ± 8.6 mm vs 28.0 ± 10.3 mm, p=0.0004). In vitro assays demonstrated an increase in the maximal number of post- versus pre-vaccination GP2-specific CTLs by dimer assay (1.45 ± 0.19 vs 0.96 ± 0.19%, p=0.06) and increased ELISPOT activity [median 86 range (3-194) vs 34 (range 0-295) spots/106 cells]. Conclusions: GP2 vaccine in combination with Tz is both safe and immunogenic in HER2-overexpressing breast cancer patients in the adjuvant setting. Toxicity was limited to mild local and systemic reactions. There were no dose limiting toxicities or cardiac events.


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