Bleomycin-induced chromosomal aberrations in Epstein-Barr virus-transformed human lymphoblastoid cells.

We have evaluated the induction of complete (i.e., without open ends) and incomplete (i.e., with non-rejoined or open ends) chromosomal aberrations by the radiomimetic antibiotic bleomycin (BLM) in human lymphoblastoid cells immortalized with the Epstein-Barr virus (EBV). An EBV-induced lymphoblastoid cell line (T-37) was exposed to BLM (10-200 µg/mL) for 2 h at 37ºC, and chromosomal aberrations were analyzed 24 h after treatment, using PNA-FISH with pan-telomeric and pan-centromeric probes. Both complete (multicentrics, rings, compound acentric fragments, and interstitial deletions) and incomplete (incomplete chromosomes or IC, and terminal acentric fragments or TAF) chromosomal aberrations increased significantly in BLM-exposed cells, although the concentration-response relationship was non-linear. Of the acentric fragments (ace) induced by BLM, 40 % were compound fragments (CF, ace +/+). TAF (ace, +/-) and interstitial fragments (IAF, ace -/-) were induced at similar frequencies (30 %). 230 ICE were induced by BLM, of which 52 % were IC and 48 % TAF. The average ratio between total incomplete chromosome elements (ICE) and multicentrics was 1.52. These findings suggest that human lymphoblastoid cells exhibit less repair capacity than human lymphocytes, with respect to BLM-induced ICE, and that chromosomal incompleteness is a common event following exposure of these cells to BLM.

Prevention of chemotherapy-related bone loss with doxorubicin-loaded solid lipid nanoparticles.

Aim: Breast cancer and its metastases involve high mortality even with advances in chemotherapy. Solid lipid nanoparticles provide a platform for drug delivery, reducing side effects and treatment-induced bone loss. A solid nanoparticle containing doxorubicin was evaluated for its ability to prevent bone loss in a pre-clinical breast cancer model.Methods: We investigated the effects of SLNDox in an aggressive metastatic stage IV breast cancer model, which has some important features that are interesting for bone loss investigation. This study evaluates bone loss prevention potential from solid lipid nanoparticles containing doxorubicin breast cancer treatment, an evaluation of the attenuation of morphological changes in bone tissue caused by the treatment and the disease and an assessment of bone loss imaging using computed tomography and electron microscopy.Results: Chemotherapy-induced bone loss was also observed in tumor-free animals; a solid lipid nanoparticle containing doxorubicin prevented damage to the growth plate and to compact and cancellous bones in the femur of tumor-bearing and healthy animals.Conclusion: The association of solid lipid nanoparticles with chemotherapeutic drugs with proven efficacy promotes the prevention of serious consequences of chemotherapy, reducing tumor progression, increasing quality of life and improving prognosis and survival.

[Box: see text].

Synergy between isobavachalcone and doxorubicin suppressed the progression of anaplastic thyroid cancer through ferroptosis activation.

The objective of this study was to explore the effects and mechanisms of the combination of isobavachalcone (IBC) and doxorubicin (DOX) on the progression of anaplastic thyroid cancer (ATC). Cell viability of 8505C and CAL62 cells was observed by CCK-8 assay. Kits were used to detect the presence of reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and cellular iron. Protein expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) was detected using western blot, and CD31 was detected through immunofluorescence. Tumor xenograft models of 8505C cells were constructed to observe the effect of IBC and DOX on ATC growth in vivo. The co-administration of IBC and DOX exhibited a synergistic effect of suppressing the growth of 8505C and CAL62 cells. The concurrent use of IBC and DOX resulted in elevated iron, ROS, and MDA levels, while reducing GSH levels and protein expression of SLC7A11 and GPX4. However, the Fer-1 ferroptosis inhibitor effectively counteracted this effect. In vitro and in vivo, the inhibitory effect on ATC cell proliferation and tumor growth was significantly enhanced by the combination of IBC and DOX. The combination of IBC and DOX can inhibit the growth of ATC by activating ferroptosis, and might prove to be a potent chemotherapy protocol for addressing ATC.

Doxorubicin-induced Immunogenic Cell Death Impairs Tumor Progression and Distant Metastasis in a 4T1 Breast Cancer Tumor Model.

INTRODUCTION: Cancer is an individual disease and its formation and development are specific to each host. Conventional treatments are ineffective in complex cases, such as metastasis, and have severe adverse side effects. New strategies are needed to address the problem, and the use of immunogenic cell death (ICD) as a trigger or booster of the immune system through the exposure of damage-associated molecular patterns, along with tumor antigens, by cancerous cells is presented as an immunization approach in this work. METHODS: For this purpose, 4T1 cells were exposed to doxorubicin (DOX) for 24 hours and then, these cells undergoing ICD were subcutaneously administered to mice. The ICD induction by DOX on 4T1 was assessed by flow cytometry and image analysis. This immunization process was performed three times and after the last administration, the immunized mice were challenged with a subcutaneous xenograft of live cancer cells. RESULTS: The results demonstrate that the mice immunized with cells undergoing ICD after exposure to DOX presented no primary tumor or indications of distant metastatic lesion development. CONCLUSION: In summary, our findings indicate that the immunization process utilizing ICD is indeed efficacious in managing this aggressive form of pre-clinical breast cancer.

Protective Effect of Long Noncoding RNA OXCT1-AS1 on Doxorubicin-Induced Apoptosis of Human Myocardial Cells by the Competitive Endogenous RNA Pattern. / Efeito Protetor do RNA Não Codificante Longo OXCT1-AS1 na Apoptose de Células Miocárdicas Humanas Induzida pela Doxorrubicina pelo Padrão Competitivo de RNA Endógeno.

BACKGROUND: The anthracycline chemotherapeutic antibiotic doxorubicin (DOX) can induce cumulative cardiotoxicity and lead to cardiac dysfunction. Long non-coding RNAs (lncRNAs) can function as important regulators in DOX-induced myocardial injury. OBJECTIVE: This study aims to investigate the functional role and molecular mechanism of lncRNA OXCT1 antisense RNA 1 (OXCT1-AS1) in DOX-induced myocardial cell injury in vitro. METHODS: Human cardiomyocytes (AC16) were stimulated with DOX to induce a myocardial cell injury model. OXCT1-AS1, miR-874-3p, and BDH1 expression in AC16 cells were determined by RT-qPCR. AC16 cell viability was measured by XTT assay. Flow cytometry was employed to assess the apoptosis of AC16 cells. Western blotting was used to evaluate protein levels of apoptosis-related markers. Dual-luciferase reporter assay was conducted to verify the binding ability between miR-874-3p and OXCT1-AS1 and between miR-874-3p and BDH1. The value of p<0.05 indicated statistical significance. RESULTS: OXCT1-AS1 expression was decreased in DOX-treated AC16 cells. Overexpression of OXCT1-AS1 reversed the reduction of cell viability and promotion of cell apoptosis caused by DOX. OXCT1-AS1 is competitively bound to miR-874-3p to upregulate BDH1. BDH1 overexpression restored AC16 cell viability and suppressed cell apoptosis under DOX stimulation. Knocking down BDH1 reversed OXCT1-AS1-mediated attenuation of AC16 cell apoptosis under DOX treatment. CONCLUSION: LncRNA OXCT1-AS1 protects human myocardial cells AC16 from DOX-induced apoptosis via the miR-874-3p/BDH1 axis.

FUNDAMENTO: O antibiótico quimioterápico antraciclina doxorrubicina (DOX) pode induzir cardiotoxicidade cumulativa e levar à disfunção cardíaca. RNAs não codificantes longos (lncRNAs) podem funcionar como importantes reguladores na lesão miocárdica induzida por DOX. OBJETIVO: Este estudo tem como objetivo investigar o papel funcional e o mecanismo molecular do RNA antisense lncRNA OXCT1 1 (OXCT1-AS1) na lesão celular miocárdica induzida por DOX in vitro. MÉTODOS: Cardiomiócitos humanos (AC16) foram estimulados com DOX para induzir um modelo de lesão celular miocárdica. A expressão de OXCT1-AS1, miR-874-3p e BDH1 em células AC16 foi determinada por RT-qPCR. A viabilidade das células AC16 foi medida pelo ensaio XTT. A citometria de fluxo foi empregada para avaliar a apoptose de células AC16. Western blotting foi utilizado para avaliar os níveis proteicos de marcadores relacionados à apoptose. O ensaio repórter de luciferase dupla foi conduzido para verificar a capacidade de ligação entre miR-874-3p e OXCT1-AS1 e entre miR-874-3p e BDH1. O valor de p<0,05 indicou significância estatística. RESULTADOS: A expressão de OXCT1-AS1 foi diminuída em células AC16 tratadas com DOX. A superexpressão de OXCT1-AS1 reverteu a redução da viabilidade celular e a promoção da apoptose celular causada pela DOX. OXCT1-AS1 está ligado competitivamente ao miR-874-3p para regular positivamente o BDH1. A superexpressão de BDH1 restaurou a viabilidade das células AC16 e suprimiu a apoptose celular sob estimulação com DOX. A derrubada do BDH1 reverteu a atenuação da apoptose de células AC16 mediada por OXCT1-AS1 sob tratamento com DOX. CONCLUSÃO: LncRNA OXCT1-AS1 protege células miocárdicas humanas AC16 da apoptose induzida por DOX através do eixo miR-874-3p/BDH1.

Doxorubicin-galactomannan nanoconjugates for potential cancer treatment.

In this study, we report the synthesis and characterization of pH-responsive nanoconjugates for targeted drug delivery. Galactomannan extracted from D. regia seeds was oxidized to form aldehyde groups, achieving a percentage of oxidation of 25.6 %. The resulting oxidized galactomannan (GMOX) was then copolymerized with PINIPAm-NH2, yielding a copolymer. The copolymer exhibited signals from both GMOX and PNIPAm-NH2 in its NMR spectrum, confirming successful copolymerization. Critical association concentration (CAC) studies revealed the formation of nanostructures, with lower CAC values observed at higher temperatures. The copolymer and GMOX reacted with doxorubicin (DOX), resulting in nanoconjugates with controlled drug release profiles, especially under acidic conditions similar to tumor microenvironments. Cytotoxicity assays demonstrated significant efficacy of the nanoconjugates against melanoma cells with reduced toxicity towards healthy cells. These findings underscore the potential of the pH-responsive nanoconjugates as promising candidates for targeted cancer therapy, offering improved therapeutic efficacy and reduced systemic side effects.

Doxorubicin-induced chemoresistance in Duke's type B colon adenocarcinoma cell line is aggravated in the presence of TGF-ß2 through non-apoptotic cell death.

BACKGROUND: The current challenge in clinical cancer treatment is chemoresistance. Colon cells have inherently higher xenobiotic transporters expression and hence can attain resistance rapidly. Increased levels of TGF-ß2 expression in patients have been attributed to cancer progression, aggressiveness, and resistance. To investigate resistance progression, we treated doxorubicin (dox) to HT-29 colon adenocarcinoma cells in the presence or absence of TGF-ß2 ligand. METHODS: After 1, 3-, and 7-day treatment, we investigated cell proliferation, viability, and cytotoxicity by MTT, trypan blue staining, and lactate dehydrogenase enzyme release. The mechanism of cell death was elucidated by hoechst33342 and propidium iodide dual staining and apoptosis assay. The development of resistance was detected by rhodamine123 efflux and P-glycoprotein (P-gp)/MDR1 antibody staining through fluorimetry and flow cytometry. The colony formation ability of the cells was also elucidated. RESULTS: Inhibition of cell proliferation was noted after day 1, while a significant reduction in viability and a significant increase in lactate dehydrogenase release was detected after day 3. Reduction of intracellular rhodamine123 levels was detected after day 3 and was significantly lower in dox with TGF-ß2 treatment compared to dox alone. Increased surface P-gp levels after days 3 and 7 were observed in the treated groups. Hoechst33342/propidium iodide staining and apoptosis assay indicated non-apoptotic cell death. The cells treated with TGF-ß2 had higher colony formation ability. CONCLUSIONS: TGF-ß2 expression might play a significant role in the development of chemoresistance to doxorubicin in Duke's type B colon adenocarcinoma cell line, HT-29.

Agaricus bisporus ß-(1 → 6)-d-glucan induces M1 phenotype on macrophages and increases sensitivity to doxorubicin of triple negative breast cancer cells.

Mushroom ß-d-glucans have demonstrated immunomodulatory activity, which is initiated by their recognition by specific receptors on immune system cells surfaces. Studies indicated that ß-d-glucans may present a synergistic effect with chemotherapy drugs. In this study, a linear ß-(1 â†’ 6)-d-glucan (B16), isolated from A. bisporus and previously characterized (Mw: 8.26 × 104 g/mol), was evaluated about its capacity to modulate THP-1 macrophages towards an M1 phenotype and induce an antitumoral activity. This was evidenced by the production of pro-inflammatory markers upon B16 treatment (30; 100 µg/mL). The breast tumor cells (MDA-MB-231) viability was not affected by treatment with B16, however, their viability markedly decreased upon treatment with the drug doxorubicin. The results showed a synergic effect of B16 and doxorubicin, which reduced the viability of MDA-MB-231 cells by 31%. Furthermore, B16 treatment provided a sustainable M1 state environment and contributed to increase the sensitivity of breast cancer cells to the doxorubicin treatment.

Integrin α2ß1 Targeting DGEA-Modified Liposomal Doxorubicin Enhances Antitumor Efficacy against Breast Cancer.

Breast cancer was the leading cause of newly diagnosed cases of tumors in 2020, ranking as the second highest cause of female death. Chemotherapy remains the conventional treatment of choice for breast tumors in most clinical cases. However, it is often accompanied by a poor prognosis and severe side effects, resulting from an insufficient accumulation of the drug at tumor sites and an unsystematic distribution of the drug across the body. Inspired by the fact that breast tumor cells overexpress integrin α2ß1 on the surface, we designed and constructed an integrin α2ß1 targeting DGEA-modified liposomal doxorubicin (DGEA-Lipo-DOX) platform for application in breast cancer therapy. The DGEA-Lipo-DOX was stable with a uniform particle size of 121.1 ± 3.8 nm and satisfactory drug encapsulation. Demonstrated in vitro and in vivo, the constructed platform exhibited improved antitumor ability. The DGEA-Lipo-DOX showed 4-fold enhanced blood circulation and 6-fold increased accumulation of DOX at the tumor sites compared to those of free DOX, resulting in a significantly enhanced antitumor efficacy in tumor-bearing mice. A preliminary safety evaluation suggested that the systemic toxicity of DOX was relieved by DGEA-Lipo delivery. Collectively, binding integrin α2ß1 by DGEA may represent an alternative therapeutic strategy for potentially safer breast cancer treatment.

CIP2A silencing alleviates doxorubicin resistance in MCF7/ADR cells through activating PP2A and autophagy.

BACKGROUND: Cancerous inhibitor of protein phosphatase 2A (CIP2A) plays a critical role in the pathogenesis of various types of cancer. Here, we investigated whether manipulating CIP2A abundance could enhance the treatment effects of doxorubicin in MCF-7/ADR cells. METHODS: CIP2A silencing was achieved by specific siRNAs. Proliferation of breast cancer cell line MCF-7/ADR under effective doxorubicin concentrations after CIP2A silencing was examined by MTT assay. Wound healing assay was performed to quantify cell migration and caspase-3/-7 activities were measured for assessing the extent of apoptosis. RESULTS: First, our data confirmed that MCF-7/ADR cell proliferation was suppressed by doxorubicin in a dose-dependent manner. Additionally, knocking down of CIP2A could further decrease MCF-7 cell proliferation and migration, even in the presence of doxorubicin. Mechanistically, we have found that CIP2A silencing promoted cell apoptosis relative to doxorubicin alone or vehicle control groups. Lastly, phosphatase2A (PP2A) activity was potentiated and the autophagy markers, LC3B and Beclin1, were upregulated after knocking down CIP2A. CONCLUSION: Our findings support the potential benefits of using CIP2A inhibitor as a therapeutic agent to treat doxorubicin-resistant breast cancer.

Proteomics Approach of Rapamycin Anti-Tumoral Effect on Primary and Metastatic Canine Mammary Tumor Cells In Vitro.

Rapamycin is an antifungal drug with antitumor activity and acts inhibiting the mTOR complex. Due to drug antitumor potential, the aim of this study was to evaluate its effect on a preclinical model of primary mammary gland tumors and their metastases from female dogs. Four cell lines from our cell bank, two from primary canine mammary tumors (UNESP-CM1, UNESP-CM60) and two metastases (UNESP-MM1, and UNESP-MM4) were cultured in vitro and investigated for rapamycin IC50. Then, cell lines were treated with rapamycin IC50 dose and mRNA and protein were extracted in treated and non-treated cells to perform AKT, mTOR, PTEN and 4EBP1 gene expression and global proteomics by mass spectrometry. MTT assay demonstrated rapamycin IC50 dose for all different tumor cells between 2 and 10 µM. RT-qPCR from cultured cells, control versus treated group and primary tumor cells versus metastatic tumor cells, did not shown statistical differences. In proteomics were found 273 proteins in all groups, and after data normalization 49 and 92 proteins were used for statistical analysis for comparisons between control versus rapamycin treatment groups, and metastasis versus primary tumor versus metastasis rapamycin versus primary tumor rapamycin, respectively. Considering the two statistical analysis, four proteins, phosphoglycerate mutase, malate dehydrogenase, l-lactate dehydrogenase and nucleolin were found in decreased abundance in the rapamycin group and they are related with cellular metabolic processes and enhanced tumor malignant behavior. Two proteins, dihydrolipoamide dehydrogenase and superoxide dismutase, also related with metabolic processes, were found in higher abundance in rapamycin group and are associated with apoptosis. The results suggested that rapamycin was able to inhibit cell growth of mammary gland tumor and metastatic tumors cells in vitro, however, concentrations needed to reach the IC50 were higher when compared to other studies.

Initial Identification of UDP-Glucose Dehydrogenase as a Prognostic Marker in Breast Cancer Patients, Which Facilitates Epirubicin Resistance and Regulates Hyaluronan Synthesis in MDA-MB-231 Cells.

UDP-glucose-dehydrogenase (UGDH) synthesizes UDP-glucuronic acid. It is involved in epirubicin detoxification and hyaluronan synthesis. This work aimed to evaluate the effect of UGDH knockdown on epirubicin response and hyaluronan metabolism in MDA-MB-231 breast cancer cells. Additionally, the aim was to determine UGDH as a possible prognosis marker in breast cancer. We studied UGDH expression in tumors and adjacent tissue from breast cancer patients. The prognostic value of UGDH was studied using a public Kaplan-Meier plotter. MDA-MB-231 cells were knocked-down for UGDH and treated with epirubicin. Epirubicin-accumulation and apoptosis were analyzed by flow cytometry. Hyaluronan-coated matrix and metabolism were determined. Autophagic-LC3-II was studied by Western blot and confocal microscopy. Epirubicin accumulation increased and apoptosis decreased during UGDH knockdown. Hyaluronan-coated matrix increased and a positive modulation of autophagy was detected. Higher levels of UGDH were correlated with worse prognosis in triple-negative breast cancer patients that received chemotherapy. High expression of UGDH was found in tumoral tissue from HER2--patients. However, UGDH knockdown contributes to epirubicin resistance, which might be associated with increases in the expression, deposition and catabolism of hyaluronan. The results obtained allowed us to propose UGDH as a new prognostic marker in breast cancer, positively associated with development of epirubicin resistance and modulation of extracellular matrix.

ST8SIA1 inhibition sensitizes triple negative breast cancer to chemotherapy via suppressing Wnt/ß-catenin and FAK/Akt/mTOR.

BACKGROUND: Chemoresistance is the major cause of therapeutic failure in triple negative breast cancer (TNBC). In this work, we investigated the molecular mechanism for the development of TNBC chemoresistance. METHODS: mRNA and protein levels of ST8SIA1 were analyzed in chemosensitive and chemoresistant TNBC cells and tissues. Proliferation and survival assays were performed to determine the role of ST8SIA1 in TNBC chemoresistance. RESULTS: We found that ST8SIA1 mRNA and protein levels were increased in multiple TNBC cell lines after prolonged exposure to chemotherapeutic drugs. Consistently, retrospective study demonstrated that the majority of TNBC patients who developed chemoresistance displayed upregulation of ST8SIA1. We further found that chemoresistant TNBC cells were more sensitive than chemosensitive cells to ST8SIA1 inhibition in decreasing growth and viability. Consistently, ST8SIA1 inhibition augmented the efficacy of chemotherapy in TNBC cells. Mechanism studies demonstrated that ST8SIA1 inhibition led to suppression of FAK/Akt/mTOR and Wnt/ß-catenin signalling pathways. CONCLUSIONS: These findings provide an explanation for the heterogeneity of chemotherapy responses across TNBC individuals and reveal the supportive roles of ST8SIA1in TNBC chemoresistance.

Doxorubicin-loaded pH-sensitive micelles: A promising alternative to enhance antitumor activity and reduce toxicity.

Doxorubicin (DOX) is an anthracycline antibiotic widely used in the treatment of cancer, however, it is associated with the occurrence of adverse reactions that limits its clinical use. In this context, the encapsulation of DOX in micelles responsive to pH variations has shown to be a strategy for tumor delivery of the drug, with the potential to increase therapeutic efficacy and to reduce the toxic effects. In addition, radiolabeling nanoparticles with a radioactive isotope is of great use in preclinical studies, since it allows the in vivo monitoring of the nanostructure through the acquisition of quantitative images. Therefore, this study aimed to develop, characterize, and evaluate the antitumor activity of a pH-sensitive micelle composed of DSPE-PEG2000, oleic acid, and DOX. The micelles had a diameter of 13 nm, zeta potential near to neutrality, and high encapsulation percentage. The critical micellar concentration (CMC) was 1.4 × 10-5 mol L-1. The pH-sensitivity was confirmed in vitro through a drug release assay. Cytotoxicity studies confirmed that the encapsulation of DOX into the micelles did not impair the drug cytotoxic activity. Moreover, the incorporation of DSPE-PEG2000-DTPA into the micelles allowed it radiolabeling with the technetium-99 m in high yield and stability, permitting its use to monitor antitumor therapy. In this sense, the pH-sensitive micelles were able to inhibit tumor growth significantly when compared to non-pH-sensitive micelles and the free drug. in vivo toxicity evaluation in the zebrafish model revealed significantly lower toxicity of pH-sensitive micelles compared to the free drug. These results indicate that the developed formulation presents itself as a promising alternative to potentiate the treatment of tumors.

Mechanistic insights into the intracellular release of doxorubicin from pH-sensitive liposomes.

pH-sensitive liposomes are interesting carriers for drug-delivery, undertaking rapid bilayer destabilization in response to pH changes, allied to tumor accumulation, a desirable behavior in the treatment of cancer cells. Previously, we have shown that pH-sensitive liposomes accumulate in tumor tissues of mice, in which an acidic environment accelerates drug delivery. Ultimately, these formulations can be internalized by tumor cells and take the endosome-lysosomal route. However, the mechanism of doxorubicin release and intracellular traffic of pH-sensitive liposomes remains unclear. To investigate the molecular mechanisms underlying the intracellular release of doxorubicin from pH-sensitive liposomes, we followed HeLa cells viability, internalization, intracellular trafficking, and doxorubicin's intracellular delivery mechanisms from pH-sensitive (SpHL-DOX) and non-pH-sensitive (nSpHL-DOX) formulations. We found that SpHL-DOX has faster internalization kinetics and intracellular release of doxorubicin, followed by strong nuclear accumulation compared to nSpHL-DOX. The increased nuclear accumulation led to the activation of cleaved caspase-3, which efficiently induced apoptosis. Remarkably, we found that chloroquine and E64d enhanced the cytotoxicity of SpHL-DOX. This knowledge is paramount to improve the efficiency of pH-sensitive liposomes or to be used as a rational strategy for developing new formulations to be applied in vivo.

Streptozotocin induces brain glucose metabolic changes and alters glucose transporter expression in the Lobster cockroach; Nauphoeta cinerea (Blattodea: Blaberidae).

The development of new models to study diabetes in invertebrates is important to ensure adherence to the 3R's principle and to expedite knowledge of the complex molecular events underlying glucose toxicity. Streptozotocin (STZ)-an alkylating and highly toxic agent that has tropism to mammalian beta cells-is used as a model of type 1 diabetes in rodents, but little is known about STZ effects in insects. Here, the cockroach; Nauphoeta cinerea was used to determine the acute toxicity of 74 and 740 nmol of STZ injection per cockroach. STZ increased the glucose content, mRNA expression of glucose transporter 1 (GLUT1) and markers of oxidative stress in the head. Fat body glycogen, insect survival, acetylcholinesterase activity, triglyceride content and viable cells in head homogenate were reduced, which may indicate a disruption in glucose utilization by the head and fat body of insects after injection of 74 and 740 nmol STZ per nymph. The glutathione S-transferase (GST) activity and reduced glutathione levels (GSH) were increased, possibly via activation of nuclear factor erythroid 2 related factor as a compensatory response against the increase in reactive oxygen species. Our data present the potential for metabolic disruption in N. cinerea by glucose analogues and opens paths for the study of brain energy metabolism in insects. We further phylogenetically demonstrated conservation between N. cinerea glucose transporter 1 and the GLUT of other insects in the Neoptera infra-class.

Partial acquisition of stemness properties in tumorspheres obtained from interleukin-8-treated MCF-7 cells.

The interleukin-8 is an important regulator of the tumor microenvironment, promoting the epithelial-mesenchymal transition and the acquisition of stem-like cell properties in cancer cells. The tumorsphere-formation assay has been used for the identification of cancer stem cell. Interleukin-8 induces the formation of larger tumorspheres in Michigan Cancer Foundation-7 (MCF-7) cells, suggesting cancer stem cell enrichment. In this work, we aimed to study the phenotypic and functional characteristics of the cells present within the tumorspheres of MCF-7 cells previously treated with interleukin-8. MCF-7 cells treated for 5 days or not with this cytokine were further cultivated in ultralow attachment plates for another 5 days to allow tumorspheres formation. We showed that the enhanced sphere formation by MCF-7 cells was not a consequence of higher cell proliferation by interleukin-8 stimulation. Despite maintaining an epithelial-mesenchymal transition phenotype with the presence of epithelial and mesenchymal markers, basic stemness properties were impaired in tumorspheres and in those treated with interleukin-8, while others were increased. Self-renewal capacity was increased in interleukin-8-treated cells only in the first generation of tumorspheres but was not sustained in consecutive assays. Accordingly, self-renewal and reprogramming gene expression, differentiation capacity to adipocytes, and clonogenicity were also impaired. We showed also that tumorspheres were enriched in differentiated luminal cells (EpCAM+/CD49f-). Nevertheless, cells were more quiescent and maintain a partial epithelial-mesenchymal transition, consistent with their increased resistance to Paclitaxel and Doxorubicin. They also presented higher migration and interleukin-8-directed invasion. Therefore, the breast cancer cell line MCF-7, having a low stemness index, might partially acquire some stem-like cell attributes after interleukin-8 stimulation, increasing its aggressiveness.

Effects of doxorubicin associated with amniotic membrane stem cells in the treatment of canine inflammatory breast carcinoma (IPC-366) cells.

BACKGROUND: Tumours in mammary glands represent the most common neoplasia in bitches, as in humans. This high incidence results in part from the stimulation of sex hormones on these glands. Among mammary tumours, inflammatory carcinoma is the most aggressive, presenting a poor prognosis to surgical treatment and chemotherapy. One of the most widely used chemotherapy drugs for breast cancer treatment is doxorubicin (DOXO). Alternative therapies have been introduced in order to assist in these treatments; studies on treatments using stem cells have emerged, since they have anti-inflammatory and immunomodulatory properties. The aim of this study was to evaluate the effects of DOXO and canine amniotic membrane stem cells (AMCs) on the triple-negative canine inflammatory mammary carcinoma cell line IPC-366. METHODS: Four experimental groups were analysed: a control group without treatment; Group I with DOXO, Group II with AMC and Group III with an association of DOXO and AMCs. We performed the MTT assay with DOXO in order to select the best concentration for the experiments. The growth curve was performed with all groups (I-III) in order to verify the potential of treatments to reduce the growth of IPC-366. For the cell cycle, all groups (I-III) were tested using propidium iodide. While in the flow cytometry, antibodies to progesterone receptor (PR), estrogen receptor (ER), PCNA, VEGF, IL-10 and TGF-ß1 were used. For steroidogenic pathway hormones, an ELISA assay was performed. RESULTS: The results showed that cells treated with 10 µg/mL DOXO showed a 71.64% reduction in cellular growth after 72 h of treatment. Reductions in the expression of VEGF and PCNA-3 were observed by flow cytometry in all treatments when compared to the control. The intracellular levels of ERs were also significantly increased in Group III (4.67% vs. 27.1%). Regarding to the levels of steroid hormones, significant increases in the levels of estradiol (E2) and estrone sulphate (S04E1) were observed in Groups I and III. On the other hand, Group II did not show differences in steroid hormone levels in relation to the control. We conclude that the association of DOXO with AMCs (Group III) promoted a reduction in cell growth and in the expression of proteins related to proliferation and angiogenesis in IPC-366 triple-negative cells. CONCLUSIONS: This treatment promoted ER positive expression, suggesting that the accumulated oestrogen conducted these cells to a synergistic state, rendering these tumour cells responsive to ERs and susceptible to new hormonal cancer therapies.

Antiproliferative Flavanoid Dimers Isolated from Brazilian Red Propolis.

Herein reported are results of the chemical and biological investigation of red propolis collected at the Brazilian Northeast coastline. New propolones A-D (1-4), with a 3-{3-[(2-phenylbenzofuran-3-yl)methyl]phenyl}chromane skeleton; propolonones A-C (5-7), with a 3-[3-(3-benzylbenzofuran-2-yl)phenyl]chromane skeleton; and propolol A (8), with a 6-(3-benzylbenzofuran-2-yl)-3-phenylchromane skeleton, were isolated as constituents of Brazilian red propolis by cytotoxicity-guided assays and structurally identified by analysis of their spectroscopic data. Propolone B (2) and propolonone A (5) display significant cytotoxic activities against an ovarian cancer cell line expressing a multiple drug resistance phenotype when compared with doxorubicin.

IKAROS and CK2 regulate expression of BCL-XL and chemosensitivity in high-risk B-cell acute lymphoblastic leukemia.

High-risk B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive disease, often characterized by resistance to chemotherapy. A frequent feature of high-risk B-ALL is loss of function of the IKAROS (encoded by the IKZF1 gene) tumor suppressor. Here, we report that IKAROS regulates expression of the BCL2L1 gene (encodes the BCL-XL protein) in human B-ALL. Gain-of-function and loss-of-function experiments demonstrate that IKAROS binds to the BCL2L1 promoter, recruits histone deacetylase HDAC1, and represses BCL2L1 expression via chromatin remodeling. In leukemia, IKAROS' function is impaired by oncogenic casein kinase II (CK2), which is overexpressed in B-ALL. Phosphorylation by CK2 reduces IKAROS binding and recruitment of HDAC1 to the BCL2L1 promoter. This results in a loss of IKAROS-mediated repression of BCL2L1 and increased expression of BCL-XL. Increased expression of BCL-XL and/or CK2, as well as reduced IKAROS expression, are associated with resistance to doxorubicin treatment. Molecular and pharmacological inhibition of CK2 with a specific inhibitor CX-4945, increases binding of IKAROS to the BCL2L1 promoter and enhances IKAROS-mediated repression of BCL2L1 in B-ALL. Treatment with CX-4945 increases sensitivity to doxorubicin in B-ALL, and reverses resistance to doxorubicin in multidrug-resistant B-ALL. Combination treatment with CX-4945 and doxorubicin show synergistic therapeutic effects in vitro and in preclinical models of high-risk B-ALL. Results reveal a novel signaling network that regulates chemoresistance in leukemia. These data lay the groundwork for clinical testing of a rationally designed, targeted therapy that combines the CK2 inhibitor, CX-4945, with doxorubicin for the treatment of hematopoietic malignancies.