Doxorubicin Treatment Research Articles

Inhibition of CISD2 enhances sensitivity to doxorubicin in diffuse large B-cell lymphoma by regulating ferroptosis and ferritinophagy

BackgroundCDGSH iron-sulfur domain 2 (CISD2), an iron-sulfur protein with a [2Fe-2S] cluster, plays a pivotal role in the progression of various cancers, including Diffuse Large B-cell Lymphoma (DLBCL). However, the mechanisms by which CISD2 regulates the occurrence and development of DLBCL remain to be fully elucidated.MethodsThe potential role of CISD2 as a predictive marker in DLBCL patients treated with the R-CHOP regimen was investigated through bioinformatics analysis and clinical cohort studies. DLBCL cell lines (SUDHL-4 and HBL-1) were employed in this research. Adenoviral (AV) plasmids were used to either silence or overexpress CISD2 in these DLBCL cell lines. Additionally, the induction of ferroptosis in DLBCL cell lines was assessed. Various parameters, including cell proliferation, intracellular free iron levels, lipid peroxides, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP), were measured. Furthermore, the expression of proteins associated with ferroptosis and ferritinophagy was analyzed. Drug-resistant DLBCL cell lines were developed by gradually increasing doxorubicin (DOX) concentration over 6 months. The biological role of CISD2 in these drug-resistant DLBCL cell lines was subsequently assessed.ResultsElevated CISD2 levels were found to be associated with decreased sensitivity of DLBCL patients to the R-CHOP regimen, as indicated by bioinformatics and clinical cohort analysis. Silencing CISD2 significantly reduced cell proliferation, increased iron accumulation, depleted glutathione (GSH), and elevated malondialdehyde (MDA) levels, alongside the accumulation of ROS and increased MMP. Additionally, BECN1 and NCOA4 expressions were upregulated, while p62, FTH1, and GPX4 expressions were downregulated. Conversely, overexpression of CISD2 reversed these effects. Treatment of DLBCL cell lines with Erastin led to decreased CISD2 levels. Notably, in drug-resistant DLBCL cell lines, CISD2 knockdown promoted ferroptosis and ferritinophagy, restoring sensitivity to DOX and enhancing the efficacy of Erastin treatment.ConclusionOur findings suggest that CISD2 may play a role in the drug resistance observed in DLBCL patients. Inhibition of CISD2 could enhance ferroptosis and ferritinophagy, potentially improving the sensitivity of DLBCL cells to DOX treatment.

Heterogeneous Formation of DNA Double-Strand Breaks and Cell-Free DNA in Leukemia T-Cell Line and Human Peripheral Blood Mononuclear Cells in Response to Topoisomerase II Inhibitors

Background: Improving precision medicine in chemotherapy requires highly sensitive and easily applicable diagnostic tools. In addition, non-invasive molecular real-time monitoring of cytotoxic response is highly desirable. Here, we employed the kinetics of DNA double-strand breaks (DSB) and cell-free DNA (cfDNA) in a cell model of topoisomerase II-inhibitors in T cell leukemia (Jurkat cells) compared to normal cells (peripheral blood mononuclear cells, PBMCs). Methods: We applied automated microscopy to quantify immuno-stained phosphorylated H2AX (γH2AX) as a marker for either DNA damage response (DDR) or cell death and quantitative PCR-based analysis of nuclear and mitochondrial cfDNA concentrations. Results: Jurkat cells displayed a DDR to cytotoxic drug treatment significantly earlier than PBMCs, and etoposide (ETP) induced DSB formation faster than doxorubicin (DOX) in both Jurkat and PBMCs. Jurkat cells exhibited an earlier cytotoxic response compared to PBMC, with a significantly increased mitochondrial cfDNA formation after 2 h of DOX application. In PBMCs, increased cell death was detected after 4 h of incubation with ETP, whereas DOX treatment was less effective. Conclusions: Both automated microscopy and mitochondrial cfDNA quantification analysis indicate that (malignant) Jurkat cells are more sensitive to DOX than (healthy) PBMC. Our real-time approach can improve DDR inducing drug selection and adaptation in cancer therapy and aids in decisions for optimal patient biosampling.

Disruption of Ferroptosis Inhibition and Immune Evasion with Tumor‐Activatable Prodrug for Boosted Photodynamic/Chemotherapy Eradication of Drug‐Resistant Tumors

AbstractBreast cancer is a malignant tumor that threatens the life and health of women worldwide. As the first‐line chemotherapy drug for breast cancer, doxorubicin (DOX) can inhibit the synthesis of RNA and DNA, and it exhibits strong inhibitory activity against breast cancer. However, drug‐induced systemic toxicity and drug resistance can occur with DOX treatment. In this work, TSPO protein is identified as a promising target for overcoming drug resistance and we designed a novel BT‐DOX/PDP conjugate to solve these problems in drug chemotherapy. It is found that BT‐DOX/PDP can effectively downregulate TSPO1 protein and sensitize MCF‐7/Adr to DOX. Furthermore, due to its positive charge, BT‐DOX/PDP is readily loaded into puerarin (PUE), the resulting BT‐DOX/PDP@PUE exhibited minimal systemic toxicity but enhanced antitumor activity in animal models, as compared with BT‐DOX/PDP. This study demonstrates the advantages of combined chemotherapy and photodynamic therapy in overcoming drug resistance, which may be applied in the design of other photodynamic therapy‐based conjugates to enhance antitumor therapy.

Abstract 4118086: Doxorubicin Induces a Cytotoxic T-cell Inflammatory Response That Contributes to Cardiac Fibrosis and Systolic Dysfunction

Background: Doxorubicin (DR), the most commonly used chemotherapy, results in dose-dependent cardiotoxicity in part by causing oxidative stress, cardiomyocyte death, and cardiac fibrosis. Whether these elicit a cardiac immune response that contributes to DR cardiomyopathy and could be targeted for cardio-protection is unknown. We hypothesized that an aberrant T-cell immune response secondary to cardiac damage contributes to DR cardiomyopathy. Methods: We treated wild type (WT) mice and CD8 + T-cell antigen restricted OTI mice with 5.0 mg/kg of DR or PBS weekly for 4 or 8 weeks and performed targeted antibody depletion of CD8 + and CD4 + T-cells. Primary mouse T-cells and cardiac fibroblasts (CFB) were used for mechanistic studies. Whole blood was analyzed by flow cytometry and proteomics in human and canine lymphoma patients before and after DR initiation. Results: DR treated mice exhibited cardiac CD8 + T-cell infiltration alongside hallmarks of DR cardiomyopathy, including declined ejection fraction (EF) measured by echocardiography, cardiac cell death, and fibrosis determined by TUNEL and picrosirius red stain. Cardiac CD8 + T-cells co-localized with αSMA + CFB and had enhanced expression of the degranulation marker CD107a and IFNγ in DR compared to PBS treated mice. DR hearts also showed increased gene and protein expression of the IFNγ inducible chemokines Cxcl9 and Cxcl10 . DR resulted in increased circulating CD8 + T-cells and the frequency of activated CD8 + cells in the cardiac draining lymph nodes. Targeted antibody depletion of CD8 + but not CD4 + T-cells in the onset of DR treatment improved EF and decreased cardiac fibrosis. OTI mice were protected from DR induced EF decline, cardiac T-cell infiltration, and cardiac fibrosis, indicating an antigen-specific CD8 + T-cell response . Mechanistically, DR induced ICAM-1 expression on CFB and ICAM-1 dependent adhesion of activated CD8 + T-cells, which in turn increased CFB αSMA expression. Contact between CD8 + T-cells and DR-treated CFB caused CD8 + T-cell degranulation and Granzyme B release that contributed to CFB activation. Human and canine cancer patients followed longitudinally had increased circulating CD8 + T-cells after anthracycline treatment, and human plasma levels of CXCL9/CXCL10 correlated with decreased EF post DR. Conclusion: Our data demonstrate a novel role for cytotoxic T-cells in DR cardiomyopathy across 3 species, through CXCL9/10-dependent cardiotropism and CD8 + T-cell dependent fibrosis.

Mitochondrial elongation confers protection against doxorubicin-induced cardiotoxicity

Doxorubicin (DOX)-induced cardiac damage remains a leading cause of death amongst cancer survivors. DOX-induced cardiotoxicity (DIC) is mediated by disturbed mitochondrial dynamics, but it remains debated that the mechanisms by which DOX disrupted equilibrium between mitochondrial fission and fusion. In the present study, we observed DOX induced mitochondrial elongation in multiple cardiovascular cell lines. Mechanically, DOX not only downregulated the mitochondrial fusion proteins including Mitofusin 1/2 (MFN1/2) and Optic atrophy 1 (OPA1), but also induced lower motility of dynamin-related protein 1(Drp1) and its phosphorylation on 637 serine, which could inhibit mitochondrial fission. Interestingly, DOX failed to induce mitochondrial elongation in cardiomyocytes co-treated with protein kinase A (PKA) inhibitor H89 or expressing phosphodeficient Drp1-S637A variants. Besides, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was able to blocked the mitochondrial elongation induced by DOX treatment, which could be phenocopied by OPA1 knockdown. Therefore, we speculated that DOX inhibited both mitochondrial fission and fusion simultaneously, yet enabled mitochondrial fusion dominate the mitochondrial dynamics, resulting in mitochondrial elongation as the main manifestation. Notably, blocking mitochondrial elongation by inhibiting Drp1-S637 phosphorylation or OPA1 knockdown aggravated DOX-induced cardiomyocytes death. Based on these results, we propose a novel mechanistic model that DOX-induced mitochondrial elongation is attributed to the equilibrium disturbance of mitochondrial dynamics, which serves as an adaptive response and confers protection against DIC.

Predictive Value of Immune Activity Changes in Breast Cancer Patients Treated With Dose-dense Neoadjuvant Chemotherapy: A Retrospective Study.

Dose-dense chemotherapy is recommended for patients with breast cancer who have a high recurrence risk. However, whether dose-dense neoadjuvant chemotherapy (ddNAC) improves patient prognoses compared to the normal-dose regimen remains controversial. In this study, we evaluated the predictive value of immune activities on short-term outcomes for patients treated with ddNAC. We classified 82 patients with human epidermal growth factor receptor 2-negative breast cancer treated with NAC into a normal dose group (62 patients) and ddNAC group (20 patients) and examined the differences in clinicopathological features. The ddNAC group was further divided according to patient responses to NAC and the predictive factors for pathological complete response (pCR) were evaluated. There were no differences in the clinicopathological features before NAC between the normal dose and ddNAC groups. Although the pCR rates tended to be higher in the ddNAC group compared than those in the normal dose group (35.0% vs. 25.8%), there was not significant difference (p=0.264). Among all patients treated with ddNAC, the absolute lymphocyte count decreased and the neutrophil-to-lymphocyte ratio increased during dose-dense doxorubicin plus cyclophosphamide treatment. There was no significant correlation between the pCR and any of the clinicopathological parameters tested including systemic peripheral markers and tumor-infiltrating lymphocyte levels. ddNAC affected the levels of systemic peripheral immune markers. However, monitoring these markers may not be useful for predicting responses to ddNAC.

Pyroptosis is not likely to play a major role in anthracycline-induced cytotoxicity in H9c2 cardiomyocytes and human cardiac endothelial cells

Abstract Background Although anthracyclines are widely used as effective chemotherapeutic agents, anthracycline-induced cardiotoxicity (AIC) causes significant morbidity and mortality. The precise mechanism of AIC remains elusive, although apoptosis may be involved. Recent research suggests pyroptosis, a programmed lytic cell death pathway, might also contribute to AIC. Although studies have focused on AIC in the myocardium, emerging evidence suggests that AIC may also affect vascular cells. Furthermore, the cytotoxicity of doxorubicin (DOX) or its supposed active metabolite, doxorubicinol (DOXOL), has not been widely investigated in cardiac vascular cells. Purpose This study examines the hypothesis that pyroptosis plays a role in DOX and DOXOL cytotoxicity in H9c2 immortalised rat cardiac myoblasts and two types of human cardiac endothelial cells. Methods In vitro experiments were conducted to ascertain dose-dependent toxicity in H9c2, and cardiac endothelial cells following treatment with DOX or DOXOL. The type of cell death was determined by assessing cell morphology and fluorescent staining with markers of apoptosis (Annexin V) and lytic cell death (Propidium Iodide PI) following DOX or DOXOL treatment in comparison to known inducers of pyroptosis (LPS & Nigericin). Western blot experiments were conducted to study the expression of GSDMD (involved in pyroptosis), and caspase 3 (involved in apoptosis), following DOX or DOXOL. A human monocytic acute myeloid leukaemia cell line (THP-1 cells) was used as a positive control for pyroptosis. Results Dose-dependent cell death following DOX treatment was higher than with DOXOL in both H9c2 and cardiac endothelial cells. DOX caused apoptotic changes in all cell types. In contrast, DOXOL had weaker effects, inducing early apoptosis. No cleavage (activation) of GSDMD or caspase 3 was detected after DOX or DOXOL. Interestingly, in THP-1 cells, DOX induced predominantly apoptotic cell death, whereas DOXOL induced predominantly pyroptotic cell death, assessed both morphologically and by caspase 3 and GSDMD cleavage. Conclusion DOX and DOXOL primarily induce apoptotic cell death in H9c2 cardiomyocytes and cardiac endothelial cells. Interestingly, DOXOL, supposedly the active metabolite, was less cytotoxic than DOX. THP-1 cells undergo apoptotic or pyroptotic cell death with DOX or DOXOL, respectively. In conclusion, anthracycline-induced cytotoxicity is likely to be due to apoptotic injury rather than pyroptosis.

Changes in blood metabolomes as potential biomarkers for severity and prognosis in doxorubicin-induced heart failure: a study in HER2-positive and HER2-negative breast cancer patients

Abstract Background The use of doxorubicin for breast cancer treatment is often limited due to cardiotoxicity. Doxorubicin was shown to cause the alterations of cardiac metabolome levels in doxorubicin-treated rats. Interestingly, these changes were robustly associated with the development of doxorubicin-induced heart failure. Unfortunately, measurements of cardiac metabolome levels are rarely possible in humans. Hence, non-invasive biomarkers as representatives of doxorubicin-induced heart failure are required in clinical research and practice. Human epidermal growth factor receptor 2 (HER2) is a point of interest in breast cancer treatment. HER2 is associated with tumor aggressiveness. However, it was observed that HER2 protected against systemic oxidative stress and dilated cardiomyopathy. Therefore, we hypothesized that the alterations of blood metabolome levels and cardiac functions following doxorubicin treatment were different between HER2-positive and HER2-negative breast cancer patients. Purpose We determined the potential roles of changes in blood metabolomes as severity and prognostic markers of doxorubicin-induced heart failure. In addition, the changes in blood metabolomes and cardiac parameters following doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients were compared. Methods HER2-positive (n=37) and HER2-negative (n=37) breast cancer patients were enrolled. Echocardiography, heart rate variability, and blood collection were performed at baseline and 2 weeks after completion of doxorubicin treatment in all patients, as well as at 3 months after completion of doxorubicin treatment in HER2-negative breast cancer patients. Blood obtained at all 3 time points was processed for measuring cardiac injury markers. Blood obtained at baseline and 2 weeks after completion of doxorubicin treatment was also processed for measuring oxidative stress in peripheral blood mononuclear cells using flow cytometry and 85 metabolome levels in plasma using mass spectrometry-based targeted metabolomics. Results Cardiac injury and systolic dysfunction at 2 weeks after completion of doxorubicin treatment were comparable between HER2-positive and HER2-negative breast cancer patients. However, only HER2-negative breast cancer patients exhibited increased systemic oxidative stress and cardiac autonomic dysfunction at this time point. Moreover, 33 and 29 blood metabolomes were altered at 2 weeks after completion of doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients, respectively (Figure). Interestingly, the changes in most of these metabolomes were correlated with the changes in cardiac parameters, both at 2 weeks and 3 months after completion of doxorubicin treatment (Figure). Conclusions The changes in blood metabolomes following doxorubicin treatment were dependent on HER2 status, which might be served as severity and prognostic markers of doxorubicin-induced heart failure.

Ivabradine prevents doxorubicin-induced cardiotoxicity via attenuating mitochondrial dysfunction and mitochondrial dynamic imbalance in H9C2 cells and rats

Abstract Background Doxorubicin (DOX) is a widely used chemotherapeutic agent, and cardiotoxicity is one of its well-known side effects, which is mediated by cardiac mitochondrial dysfunction. Ivabradine (IVA), a heart rate reduction drug, exerts benefits in various cardiac diseases as shown in both preclinical and clinical studies. However, its roles on DOX-induced cardiotoxicity have never been investigated. Purpose We determined whether IVA reduces DOX-induced cardiotoxicity by directly promoting mitochondrial function and maintaining mitochondrial dynamic balance. Methods H9C2 cells were divided into 4 groups: 1) Control, 2) DOX (10 μM, 25 h), 3) IVA (3 μM, 25 h), 4) Pretreatment with IVA (3 μM, 1 h), followed by DOX treatment (10 μM, 24 h). Then, cell viability and mitochondrial function were determined. In animal study, male Wistar rats were divided into 4 groups: 1) Control, 2) IVA (10 mg/kg/d, PO), 3) DOX (3 mg/kg/d, 6 doses, IP), 4) Co-treatment with IVA (10 mg/kg/d, PO) and DOX (3 mg/kg/d, 6 doses, IP) for 30 days. Then, heart rate, cardiac function, and cardiac mitochondrial dynamic proteins were determined. Result DOX reduced %cell viability of H9C2 cells via increasing cellular and mitochondrial oxidative stress, and reducing mitochondrial respiration (Figure 1A, B). Under DOX-induced cellular injury condition, pretreatment with IVA resulted in increasing %cell viability by 11%, decreasing cellular and mitochondrial oxidative stress; however, IVA did not affect mitochondrial respiration. Consistent with in vitro study, DOX induced cardiac dysfunction as indicated by reduced heart rate and ejection fraction, impaired mitochondrial function and mitochondrial dynamics balance (Figure 1C, D). Co-treatment with DOX and IVA had no further impact on heart rate. DOX-IVA attenuated cardiac mitochondrial dysfunction and mitochondrial dynamics imbalance, thus prevented cardiac dysfunction. Conclusion IVA effectively protected against DOX-induced cardiotoxicity through improvement of mitochondrial function, mitochondrial dynamics, and reduction of oxidative stress. These findings suggest the therapeutic potential of IVA in preventing Dox-induced cardiotoxicity.

In vivo delivery of PBAE/ZIF-8 enhances the sensitivity of colorectal cancer to doxorubicin through sh-LncRNA ASB16-AS1.

The aim of this study is to investigate the impact of sh-LncRNA ASB16-AS1 on doxorubicin (DOX) resistance in colorectal cancer (CRC). First, an in vitro study was conducted to investigate the effects of LncRNA ASB16-AS1, miR-185-5p, and TEAD1 on drug resistance in CRC cells. Subsequently, utilizing nanotechnology, poly(beta amino esters) (PBAE)/zeolitic imidazolate framework-8 (ZIF-8)@sh-LncRNA ASB16-AS1 nanoparticles (PZSNP) were synthesized and characterized, evaluating their cellular toxicity and hemolytic activity. Finally, a mouse subcutaneous tumor model was established by subcutaneous injection of SW480/DOX cell suspension to investigate the impact of PZSNP on the tumor. Under DOX treatment, downregulation of LncRNA ASB16-AS1, overexpression of miR-185-5p, or downregulation of TEAD1 suppressed the viability and proliferation of drug-resistant CRC cells while promoting apoptosis. Conversely, overexpression of LncRNA ASB16-AS1, inhibition of miR-185-5p, or overexpression of TEAD1 enhanced the viability and proliferation of drug-resistant CRC cells while inhibiting apoptosis. The synthesized PZSNP exhibited a spherical shape with an average particle size of 123.6 nm, possessed positive charge, displayed good stability. It effectively encapsulated shRNA and displayed low cellular toxicity and hemolytic activity. Under DOX treatment, significant tumor necrosis was observed in the PZSNP group, and tumor growth was suppressed without causing weight loss. LncRNA ASB16-AS1, miR-185-5p, and TEAD1 are involved in regulating cell viability, proliferation, and apoptosis, contributing to drug resistance in CRC cells. sh-LncRNA ASB16-AS1 enhances the sensitivity of CRC cells to DOX during treatment, and in vivo delivery of PZSNP may serve as an effective strategy to overcome chemotherapy resistance in CRC.

Napabucasin Inhibits Proliferation and Migration of Glioblastoma Cells (U87) by Regulating JAK2/STAT3 Signaling Pathway.

Background and Objectives: Napabucasin (NP) was discovered as a natural compound that suppresses cancer stemness by inhibiting the signal transducer and activator of the transcription 3 (STAT3) signaling pathway. In this study, the anti-proliferative and apoptotic effects of NP and the chemotherapy agent doxorubicin (DX), a natural compound, on glioblastoma cells (U87) were investigated. Materials and Methods: In this study, the effects of NP and DX on cell viability on the glioblastoma U87 cell line were determined by MTT test. Expressions of Jak2/Stat3 genes were examined by qRT-PCR. Apoptosis was evaluated by Hoescht 33258 staining. Moreover, NP, its antagonistic-synergistic effects and IC50 doses of the combined treatment of DX were determined. Results: Napabucacin and doxorubicin were found to inhibit glioblastoma U87 cell proliferation. It was determined that NP applied in the range of 0.3-1 µM and its combination with DX killed almost all of the glioblastoma cells in 48 h of application. Additionally, it was observed that Jak2/Stat3 expressions downregulated. Conclusions: These results show that NP suppresses the proliferation of glioblastoma cells. It was shown that the combination of NP and DX can prevent invasion of the U87 cell line due to its Jak2/Stat3 inhibitory effect. Since it can suppress Jak2/Stat3, an important cancer cell proliferation pathway in glioblastoma, the combination of NP and DX can be used as an alternative treatment agent. But no synergistic effect of NP and DX on the U87 cells of the glioblastoma cell line was observed.

2'3'-cGAMP interactome identifies 2'3'-cGAMP/Rab18/FosB signaling in cell migration control independent of innate immunity.

c-di-GAMP was first identified in bacteria to promote colonization, while mammalian 2'3'-cGAMP is synthesized by cGAS to activate STING for innate immune stimulation. However, 2'3'-cGAMP function beyond innate immunity remains elusive. Here, we report that 2'3'-cGAMP promotes cell migration independent of innate immunity. 2'3'-cGAMP interactome analysis identifies the small GTPase Rab18 as a 2'3'-cGAMP binding partner and effector in cell migration control. Mechanistically, 2'3'-cGAMP binds Rab18 to facilitate GTP loading and subsequent Rab18 activation, which further promotes FosB transcription in facilitating cell migration. Induced synthesis of endogenous 2'3'-cGAMP by intrabreast tumor bacterium S. aureus infection or low-dose doxorubicin treatment facilitates cell migration depending on the cGAS/cGAMP/Rab18/FosB signaling. We find that lovastatin induces Rab18 deprenylation that abolishes 2'3'-cGAMP recognition therefore suppressing cell migration. Together, our study reveals a previously unidentified 2'3'-cGAMP function in cell migration control via the 2'3'-cGAMP/Rab18/FosB signaling that provides additional insights into clinical applications of 2'3'-cGAMP.

Cardiomyocyte-specific knockout of ADAM17 alleviates doxorubicin-induced cardiomyopathy via inhibiting TNFα–TRAF3–TAK1–MAPK axis

The pathogenesis of doxorubicin-induced cardiomyopathy remains unclear. This study was carried out to test our hypothesis that ADAM17 aggravates cardiomyocyte apoptosis induced by doxorubicin and inhibition of ADAM17 may ameliorate doxorubicin-induced cardiomyopathy. C57BL/6J mice were intraperitoneally injected with a cumulative dose of doxorubicin to induce cardiomyopathy. Cardiomyocyte-specific ADAM17-knockout (A17α-MHCKO) and ADAM17-overexpressing (AAV9-oeA17) mice were generated. In addition, RNA sequencing of the heart tissues in different mouse groups and in vitro experiments in neonatal rat cardiomyocytes (NRCMs) receiving different treatment were performed. Mouse tumor models were constructed in A17fl/fl and A17α-MHCKO mice. In addition, cardiomyocyte-specific TRAF3-knockdown and TRAF3-overexpressing mice were generated. ADAM17 expression and activity were markedly upregulated in doxorubicin-treated mouse hearts and NRCMs. A17α-MHCKO mice showed less cardiomyocyte apoptosis induced by doxorubicin than A17fl/fl mice, and cardiomyocyte ADAM17 deficiency did not affect the anti-tumor effect of doxorubicin. In contrast, AAV9-oeA17 mice exhibited markedly aggravated cardiomyocyte apoptosis relative to AAV9-oeNC mice after doxorubicin treatment. Mechanistically, doxorubicin enhanced the expression of transcription factor C/EBPβ, leading to increased expression and activity of ADAM17 in cardiomyocyte, which enhanced TNF-α shedding and upregulated the expression of TRAF3. Increased TRAF3 promoted TAK1 autophosphorylation, resulting in activated MAPKs pathway and cardiomyocyte apoptosis. ADAM17 acted as a positive regulator of cardiomyocyte apoptosis and cardiac remodeling and dysfunction induced by doxorubicin by upregulating TRAF3/TAK1/MAPKs signaling. Thus, targeting ADAM17/TRAF3/TAK1/MAPKs signaling holds a promising potential for treating doxorubicin-induced cardiotoxicity.

Metformin-mediated protection against doxorubicin-induced cardiotoxicity

BackgroundA phase II clinical trial of metformin (MET) for the treatment of doxorubicin (DOX)-induced cardiotoxicity (NCT02472353) failed. ObjectivesThe aims of this study were to confirm MET-mediated protection against DOX-induced cardiotoxicity and its mechanism using H9C2 cells, and to establish a Wistar rat model of DOX-induced cardiotoxicity. Subsequently, Wistar rats were utilized to identify clinically relevant indicators for evaluating MET-mediated protection against DOX-induced cardiotoxicity, thereby facilitating early transition towards successful clinical trials. MethodsMET-mediated protection was assessed using cell viability and cytotoxicity experiments. Additionally, intramitochondrial reactive oxygen species (ROS) levels were measured using an ROS fluorescent probe (dihydroethidium) to confirm the oxidative stress mechanism. Eighteen Wistar rats were randomly allocated to the control, DOX, and DOX+MET groups; and the body weight, adverse drug reactions (ADRs), myocardial injury, cardiac function, oxidative stress, and histopathology of heart tissues were compared between groups. ResultsH9C2 cells treated with MET/Dexrazoxane demonstrated dose-dependent protection against DOX-induced cardiotoxicity. The fluorescence intensity of H9C2 cells suggested DOX-induced cardiomyocyte toxicity and MET-mediated protection against DOX-induced cardiotoxicity. In vivo experiments confirmed that a rat model of DOX-induced cardiotoxicity was successfully established, but MET-mediated protection against DOX-induced cardiotoxicity was not demonstrated. This was attributed to insufficient energy intake because of ADRs, such as vomiting. ConclusionsWe confirmed the MET-mediated protection against DOX-induced cardiomyocyte toxicity and its mechanism involving the inhibition of oxidative stress in vitro experiments. It is imperative to investigate the optimal conditions for MET-mediated protection against DOX-induced cardiotoxicity in vivo or clinical trials.

Prognostic implications of metabolism-related genes in acute myeloid leukemia.

Acute myeloid leukemia(AML) is a diverse malignancy with a prognosis that varies, being especially unfavorable in older patients and those with high-risk characteristics. Metabolic reprogramming has become a significant factor in AML development , presenting new opportunities for prognostic assessment and therapeutic intervention. Metabolism-related differentially expressed genes (mDEGs) were identified by integrating KEGG metabolic gene lists with AML gene expression data from GSE63270. Using TCGA data, we performed consensus clustering and survival analysis to investigate the prognostic significance of mDEGs. A metabolic risk model was constructed using LASSO Cox reg ression and enhanced by a nomogram incorporated clinical characteristics. The model was validated through receiver operating characteristic (ROC) curves and survival statistics. Gene network analysis was conducted to identify critical prognostic factors. The tumor immune microenvironment was evaluated using CIBERSORT and ESTIMATE algorithms, followed by correlation analysis between immune checkpoint gene expression and risk scores. Drug sensitivity predictions and in vitro assays were performed to explore the effects of mDEGs on cell proliferation and chemoresistance. An 11-gene metabolic prognostic model was established and validated. High-risk patients had worse overall survival in both training and validation cohorts (p < 0.05). The risk score was an independent prognostic factor. High-risk patients showed increased immune cell infiltration and potential response to checkpoint inhibitors but decreased drug sensitivity. The model correlated with sensitivity to drugs such as venetoclax. Carbonic anhydrase 13 (CA13) was identified as a key gene related to prognosis and doxorubicin resistance. Knocking down CA13 reduced proliferation and increased cell death with doxorubicin treatment. A novel metabolic gene signature was developed to stratify risk and predict prognosis in AML, serving as an independent prognostic factor. CA13 was identified as a potential therapeutic target. This study provides new insights into the prognostic and therapeutic implications of metabolic genes in AML.

Sensitization of Multidrug Resistant Cancer Cells to Doxorubicin Using Ebselen by Disturbing Cellular Redox Status.

Multidrug resistance (MDR) poses a significant problem in cancer treatment, often causing adverse effects during chemotherapy. Ebselen (Ebs), a synthetic organoselenium compound, affects cellular redox status in cancer cells. In the study, we observed that Ebs disrupted cellular redox balance and sensitized drug-resistant cells to doxorubicin (DOX) treatment. The combination of Ebs and DOX led to increased intracellular reactive oxygen species (ROS) levels and lipid peroxidation while decreasing the activity of thioredoxin reductase (TrxR) and cellular antioxidants in drug-resistant cells. Furthermore, this combination treatment demonstrated notable chemosensitizing effects by reducing cell viability and proliferation in MDR cells compared to DOX treatment alone. Additionally, the combination of Ebs and DOX induced DNA fragmentation and exhibited G2/M phase cell cycle arrest. Immunofluorescent analysis revealed that the Ebs and DOX combination upregulated the expression of p53 and p21, which activated the mitochondrial-dependent apoptotic pathway. The combination treatment also enhanced the upregulation of proapoptotic markers such as Bax, Caspase-3, -9, and cytochrome C, while downregulating the expression of the antiapoptotic marker Bcl-2. Therefore, the current discoveries suggest that Ebs could be employed as a drug candidate for reversing MDR in cancer cells by regulating cellular redox homeostasis.

Bag2 protects against doxorubicin-induced cardiotoxicity by maintaining Pink1-mediated mitophagy

The clinical application of Doxorubicin (DOX) is limited due to its cardiotoxicity. Mitophagy dysfunction is the primary cause of DOX-induced cardiotoxicity (DIC). However, the precise mechanism by which DOX regulates mitophagy remains elusive. Bag2 (BCL2-associated athanogene 2) is a cochaperone implicated in multiple pathological states. The aim of this study was to investigate the potential cardio-protective effects of Bag2 in DIC. C57BL/6 mice and AC16 cells were used to establish DIC model. The expression of Bag2 were measured by western blotting and immunohistochemical. The effects of Bag2 on DIC were assessed through functional gain and loss experiments. Through in vitro and in vivo experiments, we found that Bag2 expression was significantly reduced after DOX treatment. Both Bag2 knockdown and DOX administration resulted in apoptosis, mitochondrial dysfunction, and impaired mitophagy. Conversely, Bag2 overexpression exerted protective effects against these phenotypes induced by DOX stimulation. Mechanistically, Bag2 maintained mitophagy activation by binding to Pink1 and protecting it from proteasome-dependent degradation, thereby preserving mitochondrial function and protecting against myocardial lesions. Our findings suggest that Bag2 may serve as a promising therapeutic target for the treatment of DIC.

Virtual screening, molecular dynamics simulations, and in vitro validation of EGFR inhibitors as breast cancer therapeutics

A high abundance of Epidermal Growth Factor Receptor (EGFR) in malignant cells makes them a prospective therapeutic target for basal breast tumors. Although EGFR inhibitors are in development as anticancer therapeutics, there exists limitations due to the dose-limiting cytotoxicity that limits their clinical utilization, thereby necessitating the advancement of effective inhibitors. In the present study, we have developed common pharmacophore hypotheses using 30 known EGFR inhibitors. The best pharmacophore hypothesis DHRRR_1 was utilized for virtual screening (VS) of the Phase database containing 4.3 × 106 fully prepared compounds. The top 1000 hits were further subjected to ADME filtration followed by structure-based VS and Molecular Dynamics (MD) simulation investigations. Based on pharmacophore hypothesis matching, XP glide score, interactions between ligands and active site residues, ADME properties, and MD simulations, the five best hits (SN-01 through SN-05) were preferred for in-vitro cytotoxicity studies. All the molecules except SN-02 exhibited cytotoxicity in Triple Negative Breast Cancer (TNBC) cells. These potential EGFR inhibitors effectively downregulated the EGF-induced proliferation, migration, in-vitro tumorigenic capability, and EGFR activation (pEGFR) in the TNBCs. Additionally, in combination with doxorubicin, the identified EGFR inhibitors significantly decreased the EGF-induced proliferation. SN-04, and SN-05 in the presence of a lower concentration of doxorubicin markedly increased the apoptotic markers expression in the TNBCs, an effect which was comparable to a higher concentration of doxorubicin treatment, alone. These observations suggest that both SN-04 and/or SN-05 can improve the efficacy of chemotherapeutic drug, doxorubicin at a lower concentration to avert the higher dose of chemotherapeutic-induced side effects during breast cancer treatment.

P66Shc Protein—Oxidative Stress Sensor or Redox Enzyme: Its Potential Role in Mitochondrial Metabolism of Human Breast Cancer

This work presents a comprehensive evaluation of the role of p66Shc protein in mitochondrial physiology in MDA-MB-231 breast cancer cells. The use of human breast cancer cell line MDA-MB-231 and its genetically modified clones (obtained with the use of the CRISPR-Cas9 technique), expressing different levels of p66Shc protein, allowed us to demonstrate how the p66Shc protein affects mitochondrial metabolism of human breast cancer cells. Changes in the level of p66Shc (its overexpression, and overexpressing of its Serine 36-mutated version, as well as the knockout of p66Shc) exert different effects in breast cancer cells. Interestingly, knocking out p66Shc caused significant changes observed mostly in mitochondrial bioenergetic parameters. We have shown that an MDA-MB-231 (which is a strong metastatic type of breast cancer) clone lacking p66Shc protein is characterized by a significant shift in the metabolic phenotype in comparison to other MDA-MB-231 clones. Additionally, this clone is significantly more vulnerable to doxorubicin treatment. We have proved that p66Shc adaptor protein in human breast cancer cells may exert a different role than in noncancerous cells (e.g., fibroblasts).

The Effects of Photodynamic Therapy with Low-Level Diode Laser Compared with Doxorubicin on HT-29 Colorectal Adenocarcinoma Cells Viability.

Background and Objective: Colorectal adenocarcinoma is considered one of the major causes of cancer-related lethality among other type of malignancies. Given the several limitations and adverse outcomes of conventional therapeutic regimens against colorectal cancer, the focus of many investigations has been attributed to the introduction of a novel combined regimen with harmless agents. The purpose of the present study was to investigate the effect of combined doxorubicin (DOX) treatment and photodynamic therapy (PDT) on colorectal adenocarcinoma cells. Material and Methods: HT-29 cells were exposed to different concentrations of DOX, low-level (630 nm) diode laser, and methylene blue (MB) as a photosensitizer substrate separately and a combination of them. The cytotoxic effect of the DOX, laser, MB, and their combination and the IC50 value for each treatment group were calculated by 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT). The malondialdehyde (MDA) content as a biomarker of the lipid peroxidation process and liberated lactate dehydrogenase (LDH) enzyme into supernatant was determined. Results: The results of our study evidenced that a combination of photodynamic light (laser plus MB) and DOX caused a significant reduction in the percentage of HT-29 viable cells compared with control and other treatment groups. In addition, this mentioned combination led to a considerable decrease in IC50 of DOX. Increased cell membrane lipid peroxidation and cell destruction processes in the combination therapy group were proven through significant elevation of MDA content and LDH activity in the medium, respectively. Conclusion: The findings of the present study suggested that DOX combined with PDT had a better therapeutic impact on HT-29 colorectal adenocarcinoma cells. Hence, the simultaneous application of PDT along with antineoplastic drugs improves the chemosensitivity of cancerous cells via the disruption of their membrane and triggering death processes that lead to the decrease of chemotherapeutic agents required doses and undesirable effects.