GPR91 Receptor Mediates Protection against Doxorubicin-Induced Cardiotoxicity without Altering Its Anticancer Efficacy. An In Vitro Study on H9C2 Cardiomyoblasts and Breast Cancer-Derived MCF-7 Cells

RNA sequencing of formalin fixed paraffin-embedded heart tissue provides transcriptomic information about chemotherapy-induced cardiotoxicity

Gene expression of formalin-fixed paraffin-embedded (FFPE) tissue may serve for molecular studies on cardiovascular diseases. Chemotherapeutics, such as doxorubicin (DOX) may cause heart injury, but the mechanisms of these side effects of DOX are not well understood. This study aimed to investigate whether DOX-induced gene expression in archival FFPE heart tissue in experimental rats would correlate with the gene expression in fresh-frozen heart tissue by applying RNA sequencing technology. The results showed RNA from FFPE samples was degraded, resulting in a lower number of uniquely mapped reads. However, DOX-induced differentially expressed genes in FFPE were related to molecular mechanisms of DOX-induced cardiotoxicity, such as inflammation, calcium binding, endothelial dysfunction, senescence, and cardiac hypertrophy signaling. Our data suggest that, despite the limitations, RNA sequencing of archival FFPE heart tissue supports utilizing FFPE tissues from retrospective studies on cardiovascular disorders, including DOX-induced cardiotoxicity.

2-Methoxyestradiol ameliorates doxorubicin-induced cardiotoxicity by regulating the expression of GLUT4 and CPT-1B in female rats

The clinical usage of doxorubicin (DOX) is hampered due to cardiomyopathy. Studies reveal that estrogen (E2) modulates DOX-induced cardiotoxicity. Yet, the exact mechanism is unclear. The objective of the current study is to evaluate the influence of E2 and more specifically its metabolite 2-methoxyestradiol (2ME) on cardiac remodeling and the reprogramming of cardiac metabolism in rats subjected to DOX cardiotoxicity. Seventy-two female rats were divided into groups. Cardiotoxicity was induced by administering DOX (2.5 mg/kg three times weekly for 2 weeks). In some groups, the effect of endogenous E2 was abolished by ovariectomy (OVX) or by using the estrogen receptor (ER) blocker Fulvestrant (FULV). The effect of administering exogenous E2 or 2ME in the OVX group was studied. Furthermore, the influence of entacapone (COMT inhibitor) on induced cardiotoxicity was investigated. The evaluated cardiac parameters included ECG, histopathology, cardiac-related enzymes (creatine kinase isoenzyme-MB (CK-MB) and lactate dehydrogenase (LDH)), and lipid profile markers (total cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL)). The expression levels of key metabolic enzymes (glucose transporter-4 (GLUT4) and carnitine palmitoyltransferase-1B (CPT-1B)) were assessed. Our results displayed that co-treatment of E2 and/or 2ME with DOX significantly reduced DOX-induced cardiomyopathy and enhanced the metabolism of the heart through the maintenance of GLUT4 and CPT-1B enzymes. On the other hand, co-treatment of DOX with OVX, entacapone, or FULV increased the toxic effect of DOX by further reducing these important metabolic enzymes. E2 and 2ME abrogate DOX-induced cardiomyopathy partly through modulation of GLUT 4 and CPT-1B enzymes.

The critical role and functional mechanism of microRNA-146a in doxorubicin-induced apoptosis in breast cancer cells

BACKGROUND

Breast cancer among women is the most frequently diagnosed cancer and the leading cause of death worldwide. There many advances in diagnosing and treating this disease, early diagnosis and treatment are still a significant challenge in the early stages. In recent years, microRNAs have attracted much attention in cancer diagnosis and treatment. However, the role of miR-146a in breast cancer is still controversial. We aimed to investigate the roles of miR-146a in apoptosis in breast cancer cells.

METHODS

A microarray dataset from the GEO database was selected, and using the GEO2R tool, the gene expression profile of this dataset was extracted. Then, the target scan database was used to explore the miR-146a target genes. The link between the signaling pathways was collected. We used miR-146a mimic, which was transfected to the MCF-7 cells to investigate the miR-146a roles in the apoptosis. The expression levels of miR-146a and BAX, BCL-2, and p-21(most essential genes in the apoptosis) were quantified by qPCR and western blot analysis.

RESULTS

Our findings indicated that doxorubicin induces miR-146a expression. In addition, overexpression of miR-146a affected MCF-7 cell viability, induced apoptosis, and led to reduced expression levels of BCL-2 and P-21, as well as increased BAX expression levels.

CONCLUSION

Considering the role of doxorubicin in inducing apoptosis and increasing the expression of miR-146a, it can be suggested that this miR is involved in inducing apoptosis in BC cells. In addition, miR-146a can be considered a therapeutic candidate.

In vitro to clinical translation of combinatorial effects of doxorubicin and dexrazoxane in breast cancer: a mechanism-based pharmacokinetic/pharmacodynamic modeling approach

Dexrazoxane (DEX) is the only drug clinically approved to treat Doxorubicin-induced cardiotoxicity (DIC), however its impact on the anticancer efficacy of DOX is not extensively studied. In this manuscript, a proof-of-concept in vitro study is carried out to quantitatively characterize the anticancer effects of DOX and DEX and determine their nature of drug-drug interactions in cancer cells by combining experimental data with modeling approaches. First, we determined the static concentration-response of DOX and DEX in breast cancer cell lines, JIMT-1 and MDA-MB-468. With a three-dimensional (3D) response surface analysis using a competitive interaction model, we characterized their interaction to be modestly synergistic in MDA-MB-468 or modestly antagonistic in JIMT-1 cells. Second, a cellular-level, pharmacodynamic (PD) model was developed to capture the time-course effects of the two drugs which determined additive and antagonistic interactions for DOX and DEX in MDA-MB-468 and JIMT-1, respectively. Finally, we performed in vitro to in vivo translation by utilizing DOX and DEX clinical dosing regimen that was previously identified to be maximally cardioprotective, to drive tumor cell PD models. The resulting simulations showed that a 10:1 DEX:DOX dose ratio over three cycles of Q3W regimen of DOX results in comparable efficacy based on MDA-MB-468 (additive effect) estimates and lower efficacy based on JIMT-1 (antagonistic effect) estimates for DOX + DEX combination as compared to DOX alone. Thus, our developed cell-based PD models can be used to simulate different scenarios and better design preclinical in vivo studies to further optimize DOX and DEX combinations.

[Hesperetin Alleviates Doxorubicin-Induced Cytotoxicity in H9c2 Cells by Activating SIRT1/NRF2 Signaling]

Objective

To investigate whether hesperetin (Hes) alleviates doxorubicin (DOX)-induced cardiomyocytotoxicity by reducing oxidative stress via regulating silent information regulator 1 (SIRT1)/nuclear transcription factor E2-related factor 2 (NRF2) signaling in H9c2 cells.

Methods

H9c2 cells were treated with DOX to establish the cardiotoxicity model and were randomly assigned to four groups, a control group (Control) and three treatment groups, receiving respectively DOX (the DOX group), Hes+DOX (the DOX+Hes group), and Hes+SIRT1 inhibitor EX527+DOX (the DOX+Hes+EX527 group). Cellular morphology was observed by the light microscope. Cell viability was evaluated by CCK-8. DOX-induced apoptosis in H9c2 cells was examined by flow cytometry. The levels of reactive oxygen species (ROS) in the H9c2 cells of the four groups were determied with 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. The activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD), catalase (CAT), and SIRT1 as well as the malondialdehyde (MDA) content were measured using ELISA kits. The expressions of cleaved caspase-3, cytochrome c, SIRT1, Ac-FOXO1, NRF2, and heme oxygenase 1 (HO-1) were determined by Western blot.

Results

Compared with the Control group, the DOX group showed swollen cellular morphology, decreased cell density and viability, and increased LDH activity in the medium ( P<0.01); both apoptosis and the expression of cleaved caspase-3 and cytochrome c increased ( P<0.01); the activities of CAT and SOD decreased while the contents of MDA and ROS increased ( P<0.01); the expression of SIRT1, NRF2, and HO-1 decreased, the activity of SIRT1 decreased, and the expression of Ac-FOXO1 increased ( P<0.01). Compared with the DOX group, the DOX+Hes group showed improved cellular morphology, increased cell density and viability, and decreased LDH activity in the medium ( P<0.01); the apoptosis and the expression of cleaved caspase-3 and cytochrome c decreased ( P<0.01); the activities of CAT and SOD increased while the levels of MDA and ROS decreased ( P<0.01); the expression of SIRT1, NRF2, and HO-1 increased, the activity of SIRT1 increased, and the expression of Ac-FOXO1 decreased ( P<0.01). Comparison of the findings for the DOX+Hes group and the DOX+Hes+EX527 group showed that EX527 could block the protective effects of Hes against DOX-induced cell injury, oxidative stress, and SIRT1/NRF2 signaling.

Conclusion

Hes inhibits oxidative stress and apoptosis via regulating SIRT1/NRF2 signaling, thereby reducing DOX-induced cardiotoxicity in H9c2 cells.

Magnesium hexacyanoferrate nanocatalysts attenuate chemodrug-induced cardiotoxicity through an anti-apoptosis mechanism driven by modulation of ferrous iron

Distressing and lethal cardiotoxicity is one of the major severe side effects of using anthracycline drugs such as doxorubicin for cancer chemotherapy. The currently available strategy to counteract these side effects relies on the administration of cardioprotective agents such as Dexrazoxane, which unfortunately has unsatisfactory efficacy and produces secondary myelosuppression. In the present work, aiming to target the characteristic ferrous iron overload in the doxorubicin-contaminated cardiac microenvironment, a biocompatible nanomedicine prepared by the polyvinylpyrrolidone-directed assembly of magnesium hexacyanoferrate nanocatalysts is designed and constructed for highly efficient intracellular ferrous ion capture and antioxidation. The synthesized magnesium hexacyanoferrate nanocatalysts display prominent superoxide radical dismutation and catalytic H₂O₂ decomposition activities to eliminate cytotoxic radical species. Excellent in vitro and in vivo cardioprotection from these magnesium hexacyanoferrate nanocatalysts are demonstrated, and the underlying intracellular ferrous ion traffic regulation mechanism has been explored in detail. The marked cardioprotective effect and biocompatibility render these magnesium hexacyanoferrate nanocatalysts to be highly promising and clinically transformable cardioprotective agents that can be employed during cancer treatment.

In Vitro Growth Inhibition, Caspase-Dependent Apoptosis, and S and G2/M Phase Arrest in Breast Cancer Cells Induced by Fluorine-Incorporated Gold I Compound, Ph3PAu[SC(OMe)=NC6H4F-3]

Gold-based anticancer compounds have been attracting increasing research interest due to their ability to kill cancer cells resistant to platinum-based compounds. Gold I- and gold III-based complexes have shown satisfactory anticancer activities. In this study, two new fluorine-incorporated gold (I) compounds such as Ph3PAu[SC(OMe)=NC6H4F-3] and DPPFeAu2[(SC(OMe)=NC6H4F-3)]2 were evaluated for their in vitro activities against human breast cancer cell lines, primary breast cancer cells, and breast cancer stem cells (parental breast cancer stem cells, BCSC-P, and breast cancer stem cells, BCSC). Assays for growth inhibition and cytotoxicity, including real-time cell analysis, were carried out to screen effective antibreast cancer compounds. In addition, further in vitro assays such as apoptosis, caspase 3/7 activity, and cell cycle analysis were performed to observe the action and mechanism of killing breast cancer cells by the selected gold I compound, Ph3PAu[SC(OMe)=NC6H4F-3]. The gold (I) compound, Ph3PAu[SC(OMe)=NC6H4F-3], showed low toxicity to H9c2 normal cells and significant growth inhibition in MDA-MB-231 and MCF-7 cells, primary breast cancer cells, and breast cancer stem cells (BCSC-P and BCSC). The IC50 doses of the gold (I) compound Ph3PAu[SC(OMe)=NC6H4F-3] against the breast cancer cell lines MDA-MB-231 and MCF-7 were approximately 6-fold lower than that of cisplatin (cis-diamineplatinum (II) dichloride, CDDP). Moreover, the compound Ph3PAu[SC(OMe)=NC6H4F-3] induced caspase 3/7-dependent apoptosis and cell cycle arrest at S and G2/M phases. Ph3PAu[SC(OMe)=NC6H4F-3], a gold (I) compound incorporated with fluorine, is a potential candidate for the treatment of breast cancer.

Improvement of stability and in vivo antioxidant effect of human glutathione peroxidase mutant by PEGylation

Human glutathione peroxidase (GPx), as an important kind of antioxidant enzyme, is often used for the removal of reactive oxygen species. Unfortunately, the application has been hindered by its limited source and poor stability. To solve these problems, human glutathione peroxidase mutant (GPxM) with high activity and yield was obtained using Escherichia coli BL21(DE3) cys auxotrophic strain and the single-protein production system in our previous work. However, the antioxidant effect of this novel recombinant protein drug in animals has not been demonstrated, and its immunogenicity and short biological half-life as a biological macromolecule may have seriously hindered its clinical application. Therefore, it is important to find an effective strategy to address the above issues. In this work, PEGylated GPxM was prepared by conjugating the corresponding mutant with monomethoxy polyethylene glycol succinimidyl succinate (SS-mPEG). We researched the structure, stability, pharmacokinetic properties, antioxidant effect in vivo and protective mechanism against adriamycin (ADR)-mediated cardiotoxicity of modified products, and compared with the above properties of GPxM. The results revealed that GPxM had an excellent antioxidant effect in vivo, and PEGylation can enhance the stability, half-life and antioxidant effect of GPxM while reducing immunogenicity. In addition, the above improvement of PEGylated GPx1M was stronger than that of monoPEGylated GPx4M. Hence, PEGylation might be an effective method to broaden the applications of GPxM as the important antioxidant drug, especially the PEGylated GPx1M with high antioxidant effect.