Project description:Development of resistance to chemotherapy drugs is a significant problem in treating human malignancies in the clinic. Overexpression of ABC transporter proteins, including P-170 glycoprotein (P-gp), and breast cancer resistance protein (BCRP, ABCG2) have been implicated in this multi-drug resistance (MDR). These ABC transporters are ATP-dependent efflux proteins. We have recently shown that nitric oxide (NO) inhibits the ATPase activities of P-gp, resulting in a significant enhancement of drug accumulation and the reversal of multi-drug resistance in NCI/ADR-RES cells, a P-gp-overexpressing human MDR cell line. In this study, we used [O<sup>2</sup>-(2,4-dinitrophenyl)-1-[(4-ethoxycarbonyl)-piperazin-1?yl]-diazene-1-ium-1-2-diolate] (JS-K), a tumor-specific NO-donor to study the reversal of drug resistance in both P-gp- and BCRP-overexpressing human tumor cells. We report here that while JS-K was extremely effective in reversing adriamycin resistance in the P-gp-overexpressing tumor cells (NCI/ADR-RES); it was significantly resistant to BCRP-overexpressing (MCF-7/MX) tumor cells, suggesting that JS-K may be a substrate for BCRP. Using another NO-donor (DETNO), we show that NO directly inhibits the ATP activities of BCRP, inducing significant increases in the accumulations of both Hoechst 33342 dye and topotecan, substrates for BCRP. Furthermore, NO treatment significantly reversed topotecan and mitoxantrone resistance to MCF-7/MX tumor cells. Molecular docking studies indicated that while DETNO and JS-K bind to ATP binding site in both ABC proteins, binding score was significantly reduced, compared to the ATP binding. Our results indicate that appropriately designed NO donors may find success in reversing multidrug resistance in the clinic.
Project description:Multidrug resistance (MDR) is a major impediment to successful cancer chemotherapy. Co-delivery of novel MDR-reversing agents and anticancer drugs to cancer cells holds great promise for cancer treatment. MicroRNA-21 (miR-21) overexpression is associated with the development and progression of MDR in breast cancer, and it is emerging as a novel and promising MDR-reversing target. In this study, a multifunctional nanocomplex, composed of polyethylenimine (PEI)/poly(sodium 4-styrenesulfonates) (PSS)/graphene oxide (GO) and termed PPG, was prepared using the layer-by-layer assembly method to evaluate the reversal effects of PPG as a carrier for adriamycin (ADR) along with miR-21 targeted siRNA (anti-miR-21) in cancer drug resistance. ADR was firstly loaded onto the PPG surface (PPGADR) by physical mixing and anti-miR-21 was sequentially loaded onto PPGADR through electric absorption to form (anti-miR-21)PPGADR. Cell experiments showed that PPG significantly enhanced the accumulation of ADR in MCF-7/ADR cells (an ADR resistant breast cancer cell line) and exhibited much higher cytotoxicity than free ADR, suggesting that PPG could effectively reverse ADR resistance of MCF-7/ADR. Furthermore, the enhanced therapeutic efficacy of PPG could be correlated with effective silencing of miR-21 and with increased accumulation of ADR in drug-resistant tumor cells. The endocytosis study confirmed that PPG could effectively carry drug molecules into cells via the caveolae and clathrin-mediated endocytosis pathways. These results suggest that this PPG could be a potential and efficient non-viral vector for reversing MDR, and the strategy of combining anticancer drugs with miRNA therapy to overcome MDR could be an attractive approach in cancer treatment.
Project description:The aim of this study is to evaluate the effects of pravastatin on Adriamycin (ADR)-induced nephropathy and the mechanisms involved. Forty rats were divided into the following 4 groups: control, ADR (15 mg.kg-1, IP), ADR plus pravastatin (20 mg.kg-1 which was started 5 days prior to ADR injection), and ADR plus pravastatin (20 mg.kg-1 which was started 5 days after ADR injection). On day 20 after ADR injection, the animals were sacrificed. The results showed that administration of pravastatin decreased the levels of 24-h urinary protein (24-h UP), blood urea nitrogen (BUN), and creatinine (p < 0.05) which had increased after the injection of ADR; in addition, pravastatin reversed structural changes seen in ADR group. Furthermore, pravastatin elevated mRNA and protein expression of nephrin (p < 0.05) which had been reduced in ADR group. We conclude that pravastatin protects and treats renal injury induced by ADR.
Project description:N6-Methyladenosine (m6A) is the most abundant post-transcriptional modification in eukaryotes, the imbalance of which is reported to be associated with various pathological processes, including drug resistance. In this study, we analyzed the methylated RNA immunoprecipitation combined with next-generation sequencing (MeRIP-seq) data of AML cell line HL60 and its adriamycin-resistant cell line HL60/ADR. We found a total of 40550 peaks, representing 15640 genes in HL60, and a total of 38834 peaks, representing 15285 genes in HL60/ADR. A total of 4437 differentially methylated m6A peaks within 3461 genes have been found between HL60 and HL60/ADR. Among them, 3587 differentially m6A peaks within 2790 genes were hyper-methylated, and 850 m6A peaks within 671 genes were hypo-methylated. KEGG pathway analysis showed that pathways were enriched in tumor and drug-resistant related signaling pathway. Results of MeRIP-seq showed that fold enrichment of global m6A peaks was higher in HL60/ADR compared to HL60. This study provides a framework for the application of comprehensive mRNA m6A profiling towards acute myeloid leukemia cell line (HL60) and its adriamycin-resistant acute myeloid leukemia cell line (HL60/ADR). Overall design: mRNA N6-methyladenosine profiles of acute myeloid leukemia cell line (HL60) and its adriamycin-resistant acute myeloid leukemia cell line (HL60/ADR)
Project description:Aim:This study aimed to explore the regulative mechanisms of miR-27a-3p in chemo-resistance of breast cancer cells. Materials and Methods:qRT-PCR was employed to determine miR-27a-3p expression in two breast cancer cell lines, MCF-7 and MCF-7/adriamycin-resistant cell line (MCF-7/ADR). The two cell lines were treated with miR-27a-3p mimics or inhibitors or corresponding negative control (NC), respectively. The changes were investigated by qRT-PCR, CCK-8 assay, Western blot (WB), colony formation assay, and flow cytometry assay. Moreover, luciferase reporter assay was analyzed to verify the downstream target gene of miR-27a-3p. Further investigation in the correlation between miR-27a-3p and BTG2 was launched by WB, flow cytometry assay, and CCK-8 assay. The expression of Akt and p-Akt was detected by WB. Key Findings:Significantly higher miR-27a-3p expression was confirmed in MCF-7/ADR as compared with sensitive cell line MCF-7 (P<0.05). The down-regulation of miR-27a-3p in MCF-7/ADR enhanced the sensitivity of cancer cells to adriamycin treatment, decreased multidrug resistance gene 1/P-glycoprotein (MDR1/P-gp) expression, enhanced the apoptosis-related proteins expression, increased adriamycin-induced apoptosis, and inhibited cell proliferation as compared to NC groups (P<0.05). The up-regulation of miR-27a-3p in MCF-7 showed the opposite results. BTG2 is identified as a direct target of miR-27a-3p and its down-regulation reversed ADR-resistance. BTG2 treatment exhibited inhibitory effect on PI3K/Akt pathway in MCF-7/ADR cells. Significance:miR-27a-3p might be associated with resistance of breast cancer cells to adriamycin treatments, modulating cell proliferation and apoptosis by targeting BTG2 and promoting the PI3K/Akt pathway in breast cancer cells. miR-27a-3p/BTG2 axis might be a potential therapeutic target for clinical BC resistance.
Project description:Oncogene-induced senescence (OIS), a terminal cell cycle block countering (pre)neoplastic lesions, is characterised on the molecular level by trimethylated histone H3 lysine 9 (h3K9me3), a transcriptionally repressive chromatin mark linked to silencing of S-phase-promoting genes. Whether H3K9-governed chromatin remodelling influences anticancer treatment-induced senescence (TIS) and whether functional control of this mark impacts on treatment outcome is not known. We used global gene expression profiling by microarrays to gain insight into the molecular responses of Emu-myc; Suv39h1-/- B-cell lymphoma cells to senescence-inducing anticancer agent Adriamycin (ADR). Primary lymphoma cells isolated from lymph nodes of Emu-Myc; Suv39h1-/- mice were used. In this model, the c-Myc oncogene is constitutively expressed in the cells of the B-cell lineage, leading to spontaneous development of aggressive B-cell lymphomas. Adriamycin (ADR), a cytostatic drug used as a standard part of several lymphoma treatment regimens, is known to massively induce TIS in Suv39h1-proficient lymphomas, protected from apoptosis by Bcl-2 over expression (Myc;Bcl2). In order to discern the impact of Suv39h1 to TIS induction under these conditions, we analysed here transcriptional profiles of matched pairs of Emu-myc;Suv39h1-/-;Bcl2 lymphomas, untreated or treated for 5 days with ADR.
Project description:Numerous clinical studies have established the debilitating neurocognitive side effects of chemotherapy in the treatment of breast cancer, often referred as chemobrain. We hypothesize that cognitive impairments are associated with elevated microglial inflammation in the brain. Thus, either elimination of microglia or restoration of microglial function could ameliorate cognitive dysfunction. Using a rodent model of chronic Adriamycin (ADR) treatment, a commonly used breast cancer chemotherapy, we evaluated two strategies to ameliorate chemobrain: 1) microglia depletion using the colony stimulating factor-1 receptor (CSF1R) inhibitor PLX5622 and 2) human induced pluripotent stem cell-derived microglia (iMG)-derived extracellular vesicle (EV) treatment. In strategy 1 mice received ADR once weekly for 4?weeks and were then administered CSF1R inhibitor (PLX5622) starting 72?h post-ADR treatment. ADR-treated animals given a normal diet exhibited significant behavioral deficits and increased microglial activation 4-6?weeks later. PLX5622-treated mice exhibited no ADR-related cognitive deficits and near complete depletion of IBA-1 and CD68+ microglia in the brain. Cytokine and RNA sequencing analysis for inflammation pathways validated these findings. In strategy 2, 1 week after the last ADR treatment, mice received retro-orbital vein injections of iMG-EV (once weekly for 4?weeks) and 1 week later, mice underwent behavior testing. ADR-treated mice receiving EV showed nearly complete restoration of cognitive function and significant reductions in microglial activation as compared to untreated ADR mice. Our data demonstrate that ADR treatment elevates CNS inflammation that is linked to cognitive dysfunction and that attenuation of neuroinflammation reverses the adverse neurocognitive effects of chemotherapy.
Project description:As a prevalent tumor among women, breast cancer is still an incurable disease due to drug resistance. In this study, we report microRNA-221 to have a significant effect on breast cancer resistance to adriamycin. The microRNA-221 is elevated in tumor tissue compared with nearby nontumor samples, as well as in breast cancer cell line with adriamycin resistance (MCF-7/ADR) compared to its parental line (MCF-7) and the normal breast epithelial cell line (MCF-10A). Enforced level of microRNA-221 promotes cancer resistance to adriamycin, which in turn sustains cell survival and exacerbates malignant formation. Reciprocally, the silence of microRNA-221 in cancer cells augments the sensitivity to chemotherapy, thereby resulting in enhanced apoptosis of MCF-7/ADR cells. Mechanistically, we identify PTEN as a direct target of microRNA-221, which was conversely associated with a microRNA-221 level in breast tumors. The knock-down of PTEN partially reversed the stimulatory role of microRNA-221 in the modulation of the Akt/mTOR signaling. Taken together, these findings suggest microRNA-221 suppresses PTEN transcription and activates Akt/mTOR pathway, which in turn enhances breast cancer resistance to adriamycin and promotes cancer development. Our data thus illuminate the microRNA-221/PTEN axis may act as a promising strategy for the treatment of chemotherapy-resistant breast tumors.
Project description:Inflammation has recently been attributed to dysbiosis of the gut microbiome, which has been linked to proteinuria in chronic kidney disease. Since Adriamycin® (ADR) is widely used to induce proteinuria in mouse models, the aim of this study was to explore the potential effect of gut microbiome on this process. Both ADR resistant (C57BL/6) and susceptible (BALB/C) strains were part of the induced nephropathy with ADR injection. BALB/C mice significantly presented increased urinary albumin/creatinine ratio (UACR) with renal lesions in pathology, but C57BL/6 mice were absent from kidney damage. Species and genus level resolution analysis showed a shift in gut microbial profile between BALB/C and C57BL/6 mice. ADR further altered the stool microbiome in BALB/C mice, particularly with enrichment of Odoribacter and depletion of Turicibacter, Marvinbryantia and Rikenella. Moreover, the level of UACR in BALB/C mice was marked related to the abundance of Marvinbryantia, Odoribacter and Turicibacter in stool. Meanwhile, ADR remarkably increased the serum levels of interleukin (IL)-2 in BALB/C mice, but not in C57BL/6 mice. It is suggested that the favorably altered stools as shown in the microbiome might promote the inflammation and proteinuria in ADR-sensitive mice, which provides a new insight on the pathogenicity of chronic kidney disease.
Project description:Adriamycin (ADR) is a commonly used chemotherapeutic agent that also produces significant tissue damage. Mutations to mitochondrial DNA (mtDNA) and reductions in mtDNA copy number have been identified as contributors to ADR-induced injury. ADR nephropathy only occurs among specific mouse inbred strains, and this selective susceptibility to kidney injury maps as a recessive trait to chromosome 16A1-B1. Here, we found that sensitivity to ADR nephropathy in mice was produced by a mutation in the Prkdc gene, which encodes a critical nuclear DNA double-stranded break repair protein. This finding was confirmed in mice with independent Prkdc mutations. Overexpression of Prkdc in cultured mouse podocytes significantly improved cell survival after ADR treatment. While Prkdc protein was not detected in mitochondria, mice with Prkdc mutations showed marked mtDNA depletion in renal tissue upon ADR treatment. To determine whether Prkdc participates in mtDNA regulation, we tested its genetic interaction with Mpv17, which encodes a mitochondrial protein mutated in human mtDNA depletion syndromes (MDDSs). While single mutant mice were asymptomatic, Prkdc/Mpv17 double-mutant mice developed mtDNA depletion and recapitulated many MDDS and ADR injury phenotypes. These findings implicate mtDNA damage in the development of ADR toxicity and identify Prkdc as a MDDS modifier gene and a component of the mitochondrial genome maintenance pathway.