Glycyrrhetinic Acid as a Hepatocyte Targeting Ligand-Functionalized Platinum(IV) Complexes for Hepatocellular Carcinoma Therapy and Overcoming Multidrug Resistance.

Promising targeted therapy options to overcome drug resistance and side effects caused by platinum(II) drugs for treatment in hepatocellular carcinoma are urgently needed. Herein, six novel multifunctional platinum(IV) complexes through linking platinum(II) agents and glycyrrhetinic acid (GA) were designed and synthesized. Among them, complex 20 showed superior antitumor activity against tested cancer cells including cisplatin resistance cells than cisplatin and simultaneously displayed good liver-targeting ability. Moreover, complex 20 can significantly cause DNA damage and mitochondrial dysfunction, promote reactive oxygen species generation, activate endoplasmic reticulum stress, and eventually induce apoptosis. Additionally, complex 20 can effectively inhibit cell migration and invasion and trigger autophagy and ferroptosis in HepG-2 cells. More importantly, complex 20 demonstrated stronger tumor inhibition ability than cisplatin or the combo of cisplatin/GA with almost no systemic toxicity in HepG-2 or A549 xenograft models. Collectively, complex 20 could be developed as a potential anti-HCC agent for cancer treatment.

Enhanced Efficacy against Drug-Resistant Tumors Enabled by Redox-Responsive Mesoporous-Silica-Nanoparticle-Supported Lipid Bilayers as Targeted Delivery Vehicles.

Multidrug resistance (MDR) is frequently induced after long-term exposure to reduce the therapeutic effect of chemotherapeutic drugs, which is always associated with the overexpression of efflux proteins, such as P-glycoprotein (P-gp). Nano-delivery technology can be used as an efficient strategy to overcome tumor MDR. In this study, mesoporous silica nanoparticles (MSNs) were synthesized and linked with a disulfide bond and then coated with lipid bilayers. The functionalized shell/core delivery systems (HT-LMSNs-SS@DOX) were developed by loading drugs inside the pores of MSNs and conjugating with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and hyaluronic acid (HA) on the outer lipid surface. HT-LMSNs-SS and other carriers were characterized and assessed in terms of various characteristics. HT-LMSNs-SS@DOX exhibited a dual pH/reduction responsive drug release. The results also showed that modified LMSNs had good dispersity, biocompatibility, and drug-loading capacity. In vitro experiment results demonstrated that HT-LMSNs-SS were internalized by cells and mainly by clathrin-mediated endocytosis, with higher uptake efficiency than other carriers. Furthermore, HT-LMSNs-SS@DOX could effectively inhibit the expression of P-gp, increase the apoptosis ratios of MCF-7/ADR cells, and arrest cell cycle at the G0/G1 phase, with enhanced ability to induce excessive reactive oxygen species (ROS) production in cells. In tumor-bearing model mice, HT-LMSNs-SS@DOX similarly exhibited the highest inhibition activity against tumor growth, with good biosafety, among all of the treatment groups. Therefore, the nano-delivery systems developed herein achieve enhanced efficacy towards resistant tumors through targeted delivery and redox-responsive drug release, with broad application prospects.

[Stellera chamaejasme against multidrug resistance of triple-negative breast cancer MDA-MB-231 cell through Nrf2].

This study aims to investigate the effect and mechanism of Stellera chamaejasme extract(SCL) on multidrug resistance(MDR) in breast cancer. Human triple-negative breast cancer cell line MDA-MB-231 and its adriamycin-resistant cell line MDA-MB-231/ADR were used in the experiment. Cell viability was detected by methyl thiazolyl tetrazolium(MTT) assay, and cell apoptosis was detected by DAPI staining and Annexin-V/Pi double staining. Western blot(WB) was used to detect the expression levels of Keap1, Nrf2, HO-1, Bcl-2, Bax, caspase-9, and caspase-3. Immunofluorescence staining was used to observe the distribution of Nrf2 in the cell, and flow cytometry was used to detect the level of reactive oxygen species(ROS) in the cell. The results showed that the resis-tance factor of SCL was 0.69, and that of adriamycin and paclitaxel was 8.40 and 16.36, respectively. DAPI staining showed that SCL could cause nuclear shrinkage and fragmentation of breast cancer cells. Annexin-V/Pi double staining showed that the average apoptosis rate of the drug-resistant cells was 32.64% and 50.29%, respectively under medium and high doses of SCL. WB results showed that SCL could significantly reduce the expression levels of anti-apoptotic proteins Bcl-2, caspase-9, and caspase-3 and significantly increase the expression level of pro-apoptotic protein Bax. Further studies showed that SCL could significantly promote the expression of Keap1, significantly inhibit the expression of Nrf2 and HO-1, and significantly reduce the expression level of Nrf2 in the nucleus. Correspondingly, flow cytometry showed that the intracellular ROS level was significantly increased. In conclusion, SCL can significantly inhibit the proliferation of MDA-MB-231 multidrug-resistant cells of triple-negative breast cancer and cause cell apoptosis, and the mechanism is related to inhibiting Keap1/Nrf2 signaling pathway, leading to ROS accumulation in drug-resistant cells and increasing the expression of apoptosis-related proteins.

Novel pyxinol amide derivatives bearing an aliphatic heterocycle as P-glycoprotein modulators for overcoming multidrug resistance.

P-glycoprotein (Pgp) modulators are promising agents for overcoming multidrug resistance (MDR) in cancer chemotherapy. In this study, via structural optimization of our lead compound S54 (nonsubstrate allosteric inhibitor of Pgp), 29 novel pyxinol amide derivatives bearing an aliphatic heterocycle were designed, synthesized, and screened for MDR reversal activity in KBV cells. Unlike S54, these active derivatives were shown to transport substrates of Pgp. The most potent derivative 4c exhibited promising MDR reversal activity (IC50 of paclitaxel = 8.80 ± 0.56 nM, reversal fold = 211.8), which was slightly better than that of third-generation Pgp modulator tariquidar (IC50 of paclitaxel = 9.02 ± 0.35 nM, reversal fold = 206.6). Moreover, the cytotoxicity of this derivative was 8-fold lower than that of tariquidar in human normal HK-2 cells. Furthermore, 4c blocked the efflux function of Pgp and displayed high selectivity for Pgp but had no effect on its expression and distribution. Molecular docking revealed that 4c bound preferentially to the drug-binding domain of Pgp. Overall, 4c is a promising lead compound for developing Pgp modulators.

(2,6-Dimethylphenyl)arsonic Acid Induces Apoptosis through the Mitochondrial Pathway, Downregulates XIAP, and Overcomes Multidrug Resistance to Cytostatic Drugs in Leukemia and Lymphoma Cells In Vitro.

Cancer treatment is greatly challenged by drug resistance, highlighting the need for novel drug discoveries. Here, we investigated novel organoarsenic compounds regarding their resistance-breaking and apoptosis-inducing properties in leukemia and lymphoma. Notably, the compound (2,6-dimethylphenyl)arsonic acid (As2) demonstrated significant inhibition of cell proliferation and induction of apoptosis in leukemia and lymphoma cells while sparing healthy leukocytes. As2 reached half of its maximum activity (AC50) against leukemia cells at around 6.3 µM. Further experiments showed that As2 overcomes multidrug resistance and sensitizes drug-resistant leukemia and lymphoma cell lines to treatments with the common cytostatic drugs vincristine, daunorubicin, and cytarabine at low micromolar concentrations. Mechanistic investigations of As2-mediated apoptosis involving FADD (FAS-associated death domain)-deficient or Smac (second mitochondria-derived activator of caspases)/DIABLO (direct IAP binding protein with low pI)-overexpressing cell lines, western blot analysis of caspase-9 cleavage, and measurements of mitochondrial membrane integrity identified the mitochondrial apoptosis pathway as the main mode of action. Downregulation of XIAP (x-linked inhibitor of apoptosis protein) and apoptosis induction independent of Bcl-2 (B-cell lymphoma 2) and caspase-3 expression levels suggest the activation of additional apoptosis-promoting mechanisms. Due to the selective apoptosis induction, the synergistic effects with common anti-cancer drugs, and the ability to overcome multidrug resistance in vitro, As2 represents a promising candidate for further preclinical investigations with respect to refractory malignancies.

Using nanotechnology to progress the utilization of marine natural products in combating multidrug resistance in cancer: A prospective strategy.

Achieving targeted, customized, and combination therapies with clarity of the involved molecular pathways is crucial in the treatment as well as overcoming multidrug resistance (MDR) in cancer. Nanotechnology has emerged as an innovative and promising approach to address the problem of drug resistance. Developing nano-formulation-based therapies using therapeutic agents poses a synergistic effect to overcome MDR in cancer. In this review, we aimed to highlight the important pathways involved in the progression of MDR in cancer mediated through nanotechnology-based approaches that have been employed to circumvent them in recent years. Here, we also discussed the potential use of marine metabolites to treat MDR in cancer, utilizing active drug-targeting nanomedicine-based techniques to enhance selective drug accumulation in cancer cells. The discussion also provides future insights for developing complex targeted, multistage responsive nanomedical drug delivery systems for effective cancer treatments. We propose more combinational studies and their validation for the possible marine-based nanoformulations for future development.

A convenient protonated strategy for constructing nanodrugs from hydrophobic drug-inhibitor conjugates to reverse tumor multidrug resistance.

Combination therapy has proven effective in counteracting tumor multidrug resistance (MDR). However, the pharmacokinetic differences among various drugs and inherent water insolubility for most small molecule agents greatly hinder their synergistic effects, which makes the delivery of drugs for combination therapy in vivo a key problem. Herein, we propose a protonated strategy to transform a water-insoluble small molecule drug-inhibitor conjugate into an amphiphilic one, which then self-assembles into nanoparticles for co-delivery in vivo to overcome tumor MDR. Specifically, paclitaxel (PTX) is first coupled with a third-generation P-glycoprotein (P-gp) inhibitor zosuquidar (Zos) through a glutathione (GSH)-responsive disulfide bond to produce a hydrophobic drug-inhibitor conjugate (PTX-ss-Zos). Subsequently treated with hydrochloric acid ethanol solution (HCl/EtOH), PTX-ss-Zos is transformed into the amphiphilic protonated precursor and then forms nanoparticles (PTX-ss-Zos@HCl NPs) in water by molecular self-assembly. PTX-ss-Zos@HCl NPs can be administered intravenously and accumulated specifically at tumor sites. Once internalized by cancer cells, PTX-ss-Zos@HCl NPs can be degraded under the overexpressed GSH to release PTX and Zos simultaneously, which synergistically reverse tumor MDR and inhibit tumor growth. This offers a promising strategy to develop small molecule self-assembled nanoagents to reverse tumor MDR in combination therapy.

The SMAC mimetic GDC-0152 is a direct ABCB1-ATPase activity modulator and BIRC5 expression suppressor in cancer cells.

Upregulation of the multidrug efflux pump ABCB1/MDR1 (P-gp) and the anti-apoptotic protein BIRC5/Survivin promotes multidrug resistance in various human cancers. GDC-0152 is a DIABLO/SMAC mimetic currently being tested in patients with solid tumors. However, it is still unclear whether GDC-0152 is therapeutically applicable for patients with ABCB1-overexpressing multidrug-resistant tumors, and the molecular mechanism of action of GDC-0152 in cancer cells is still incompletely understood. In this study, we found that the potency of GDC-0152 is unaffected by the expression of ABCB1 in cancer cells. Interestingly, through in silico and in vitro analysis, we discovered that GDC-0152 directly modulates the ABCB1-ATPase activity and inhibits ABCB1 multidrug efflux activity at sub-cytotoxic concentrations (i.e., 0.25×IC50 or less). Further investigation revealed that GDC-0152 also decreases BIRC5 expression, induces mitophagy, and lowers intracellular ATP levels in cancer cells at low cytotoxic concentrations (i.e., 0.5×IC50). Co-treatment with GDC-0152 restored the sensitivity to the known ABCB1 substrates, including paclitaxel, vincristine, and YM155 in ABCB1-expressing multidrug-resistant cancer cells, and it also restored the sensitivity to tamoxifen in BIRC5-overexpressing tamoxifen-resistant breast cancer cells in vitro. Moreover, co-treatment with GDC-0152 restored and potentiated the anticancer effects of paclitaxel in ABCB1 and BIRC5 co-expressing xenograft tumors in vivo. In conclusion, GDC-0152 has the potential for use in the management of cancer patients with ABCB1 and BIRC5-related drug resistance. The findings of our study provide essential information to physicians for designing a more patient-specific GDC-0152 clinical trial program in the future.

Mechanism of Induction of P-gp Activity During MET Induced by DEX in Lung Cancer Cell Line.

Lung cancer metastasis often leads to a poor prognosis for patients. Mesenchymal-epithelial transition (MET) is one key process associated with metastasis. MET has also been linked to multidrug drug resistance (MDR). MDR arises from the overactivity of drug efflux transporters such as P-glycoprotein (P-gp) which operate at the cell plasma membrane, under the regulatory control of the scaffold proteins ezrin (Ezr), radixin (Rdx), and moesin (Msn), collectively known as ERM proteins. The current study was intended to clarify the functional changing of P-gp and the underlying mechanisms in the context of dexamethasone (DEX)-induced MET in lung cancer cells. We found that the mRNA and membrane protein expression of Ezr and P-gp was increased in response to DEX treatment. Moreover, the DEX-treated group exhibited an increase in Rho123 efflux, and it was reversed by treatment with the P-gp inhibitor verapamil or Ezr siRNA. The decrease in cell viability with paclitaxel (PTX) treatment was mitigated by pretreatment with DEX. The increased expression and activation of P-gp during the progression of lung cancer MET was regulated by Ezr. The regulatory mechanism of P-gp expression and activity may differ depending on the cell status.

Paynantheine more effectively reverses multidrug resistance in malignant EPG85.257RDB and MCF7MX cells than morphine and speciociliatine.

The possible interactions of morphine, paynantheine and speciociliatine alkaloids with ATP-binding cassette (ABC) transporters was investigated. The compounds were docked against ABCG2 and ABCB1 to predict the binding mode of alkaloids in active binding sites. The cytotoxicity of morphine, paynantheine and speciociliatine for EPG85.257RDB and MCF7MX cells was determined and ABCB1 and ABCG2 gene and protein expression were determined. The binding score of paynantheine to ABCB1 was higher in the docking studies. Paynantheine and speciociliatine had similar binding scores to ABCB1, but higher binding scores to ABCG2 than did morphine. Paynantheine and speciociliatine were more effective against MCF7MX and EPG85.257RDB cells and showed greater cyctotoxicity in the MTT assay. The effect of morphine and paynantheine on the ABCB1 gene and protein expression suggests these compounds can reduce resistance in cancer patients, but that speciociliatine may not be a suitable candidate because of its increased ABCB1 expression while speciociliatine decreased the expression of ABCG2 in MCF7MX cells. This indicates that speciociliatine is a better candidate for reducing drug resistance in this cell line. Structural modification, drug-metabolizing enzymes and differences in the binding sites could cause functional differences between these compounds.

Acquired Multidrug Resistance in AML Is Caused by Low Apoptotic Priming in Relapsed Myeloblasts.

In many cancers, mortality is associated with the emergence of relapse with multidrug resistance (MDR). Thus far, the investigation of cancer relapse mechanisms has largely focused on acquired genetic mutations. Using acute myeloid leukemia (AML) patient-derived xenografts (PDX), we systematically elucidated a basis of MDR and identified drug sensitivity in relapsed AML. We derived pharmacologic sensitivity for 22 AML PDX models using dynamic BH3 profiling (DBP), together with genomics and transcriptomics. Using in vivo acquired resistant PDXs, we found that resistance to unrelated, narrowly targeted agents in distinct PDXs was accompanied by broad resistance to drugs with disparate mechanisms. Moreover, baseline mitochondrial apoptotic priming was consistently reduced regardless of the class of drug-inducing selection. By applying DBP, we identified drugs showing effective in vivo activity in resistant models. This study implies evasion of apoptosis drives drug resistance and demonstrates the feasibility of the DBP approach to identify active drugs for patients with relapsed AML. SIGNIFICANCE: Acquired resistance to targeted therapy remains challenging in AML. We found that reduction in mitochondrial priming and common transcriptomic signatures was a conserved mechanism of acquired resistance across different drug classes in vivo. Drugs active in vivo can be identified even in the multidrug resistant state by DBP.

Novel hybrid compounds of sclareol and doxorubicin as potential anticancer nanotherapy for glioblastoma.

Two novel hybrid compounds, CON1 and CON2, have been developed by combining sclareol (SC) and doxorubicin (DOX) into a single molecular entity. These hybrid compounds have a 1:1 molar ratio of covalently linked SC and DOX. They have demonstrated promising anticancer properties, especially in glioblastoma cells, and have also shown potential in treating multidrug-resistant (MDR) cancer cells that express the P-glycoprotein (P-gp) membrane transporter. CON1 and CON2 form nanoparticles, as confirmed by Zetasizer, transmission electron microscopy (TEM), and chemical modeling. TEM also showed that CON1 and CON2 can be found in glioblastoma cells, specifically in the cytoplasm, different organelles, nucleus, and nucleolus. To examine the anticancer properties, the U87 glioblastoma cell line, and its corresponding multidrug-resistant U87-TxR cell line, as well as patient-derived astrocytoma grade 3 cells (ASC), were used, while normal human lung fibroblasts were used to determine the selectivity. CON1 and CON2 exhibited better resistance and selectivity profiles than DOX, showing less cytotoxicity, as evidenced by real-time cell analysis, DNA damage determination, cell death induction, mitochondrial respiration, and mitochondrial membrane depolarization studies. Cell cycle analysis and the ß-galactosidase activity assay suggested that glioblastoma cells die by senescence following CON1 treatment. Overall, CON1 and CON2 showed great potential as they have better anticancer features than DOX. They are promising candidates for additional preclinical and clinical studies on glioblastoma.

Evaluation of ABT-751, a novel anti-mitotic agent able to overcome multi-drug resistance, in melanoma cells.

PURPOSE: Drug efflux transporter associated multi-drug resistance (MDR) is a potential limitation in the use of taxane chemotherapies for the treatment of metastatic melanoma. ABT-751 is an orally bioavailable microtubule-binding agent capable of overcoming MDR and proposed as an alternative to taxane-based therapies. METHODS: This study compares ABT-751 to taxanes in vitro, utilizing seven melanoma cell line models, publicly available gene expression and drug sensitivity databases, a lung cancer cell line model of MDR drug efflux transporter overexpression (DLKP-A), and drug efflux transporter ATPase assays. RESULTS: Melanoma cell lines exhibit a low but variable protein and RNA expression of drug efflux transporters P-gp, BCRP, and MDR3. Expression of P-gp and MDR3 correlates with sensitivity to taxanes, but not to ABT-751. The anti-proliferative IC50 profile of ABT-751 was higher than the taxanes docetaxel and paclitaxel in the melanoma cell line panel, but fell within clinically achievable parameters. ABT-751 IC50 was not impacted by P-gp-overexpression in DKLP-A cells, which display strong resistance to the P-gp substrate taxanes compared to DLKP parental controls. The addition of ABT-751 to paclitaxel treatment significantly decreased cell proliferation, suggesting some reversal of MDR. ATPase activity assays suggest that ABT-751 is a potential BCRP substrate, with the ability to inhibit P-gp ATPase activity. CONCLUSION: Our study confirms that ABT-751 is active against melanoma cell lines and models of MDR at physiologically relevant concentrations, it inhibits P-gp ATPase activity, and it may be a BCRP and/or MDR3 substrate. ABT-751 warrants further investigation alone or in tandem with other drug efflux transporter inhibitors for hard-to-treat MDR melanoma.

Fostensavir trometamol 600 mg para o tratamento de indivíduos adultos vivendo com HIV multirresistentes aos antirretrovirais / Fostensavir trometamol 600 mg for the treatment of individuals adults living with multidrug-resistant HIV

INTRODUÇÃO: O HIV-1 é um vírus que apresenta em seu envelope viral a glicoproteína gp120, capaz de se ligar aos receptores CD4+ dos linfócitos T do hospedeiro, inviabilizando o funcionamento normal ou levando à destruição das células do sistema imune da pessoa vivendo com esse agente infeccioso. No contexto do tratamento contra o vírus, as quasispécies de HIV-1 podem sofrer uma ou mais mutações genéticas que afetam a atividade de um ou mais ARVs que já foram efetivos anteriormente, processo que é denominado resistência. Segundo a Organização Mundial de Saúde (OMS), observa-se em diversos países que a resistência atinge mais de 10% dos indivíduos em início ou reinício do tratamento contra o HIV. PERGUNTA: Fostensavir 600 mg é eficaz, custo-efetivo e seguro no tratamento de pessoas adultas vivendo com HIV-1 multirresistente aos ARVs? EVIDÊNCIAS CLÍNICAS: A partir da pergunta de pesquisa, foi desenvolvida estratégia de busca nas bases de dados MEDLINE via PubMed e EMBASE. A busca realizada resultou em 318 publicações. Foram inicialmente excluídas 72 por serem duplicatas. Posteriormente, foram excluídas outras 220 após triagem. Após leitura dos textos completos, chegou-se ao resultado de cinco publicações elegíveis, todas fruto do ensaio clínico randomizado de fase III, BRIGHTE. Foram relatados os desfechos de média de redução de carga viral, resposta virológica, falha virológica, variação média de linfócitos T CD4+, eventos adversos, morte, qualidade de vida e adesão ao tratamento. Em geral, o nível de certeza das evidências foi classificado como baixo, com risco de viés grave. AVALIAÇÃO ECONÔMICA: Utilizando um modelo de árvore de decisão, foi realizada uma análise para estimar a razão de custo-efetividade incremental (RCEI) do fostensavir 600 mg para pessoas vivendo com HIV-Aids, adultos e com multirresistência a pelo menos quatro classes terapêuticas de antirretrovirais desde que combinado a pelo menos um ARV totalmente ativo para um ano. O modelo comparou o fostensavir à terapia de base otimizada (TBO) apresentada no estudo pivotal BRIGHTE. ANÁLISE DE IMPACTO ORÇAMENTÁRIO: Foram projetados dois cenários de incorporação para a difusão do fostensavir: conservador e moderado. No cenário de difusão conservador (market share 10% ao ano), o impacto da incorporação do fostensavir em cinco anos variou entre R$ 10.975.053,60 e R$ 65.109.874,58, de 2024 a 2028 respectivamente. O impacto orçamentário acumulado em cinco anos no cenário conservador foi R$ 185.241.468,80. No cenário de difusão moderado (market share 20% ao ano), o impacto da incorporação em cinco anos variou entre R$ 10.975.053,60 e R$ 117.197.774,25, de 2024 a 2028. O impacto orçamentário acumulado em cinco anos no cenário de difusão moderado foi R$ 310.435.446,95. Monitoramento do horizonte tecnológico: Foram identificadas duas tecnologias para o tratamento de pessoas adultas convivendo com HIV multirresistente. Lenacapavir, que está registrado nas agências EMA e FDA, e ibalizumabe, com registro na FDA. PERSPECTIVA DO PACIENTE: A chamada pública nº 30/2023 ficou aberta entre 14 e 24 de agosto de 2023. Duas pessoas se inscreveram. O representante titular contou que tem 50 anos e há 25 vive com HIV. Acredita já ter usado todas as classes de medicamentos por conta da multirresistência do HIV aos ARV, chegando a ficar sem opção terapêutica por cinco ou seis anos. Atualmente utiliza a combinação maraviroque, dolutegravir, tenofovir, lamivudina, darunavir e ritonavir, com a qual consegue obter a supressão da carga viral. Ressaltou que quem vive com HIV há muito tempo corre o risco de ficar sem opção de medicamentos e que a incorporação de novas tecnologias pode beneficiar pessoas como ele. RECOMENDAÇÃO PRELIMINAR DA CONITEC: Os membros do Comitê de Medicamentos presentes na 125ª Reunião Ordinária, realizada no dia 6 de dezembro de 2023, deliberaram, por unanimidade, encaminhar o tema para consulta pública com recomendação preliminar favorável à incorporação do fostensavir trometamol 600 mg para o tratamento de pessoas vivendo com HIV-Aids multirresistentes a terapia antirretroviral. Considerou-se a oportunidade de uma opção terapêutica aos indivíduos multirresitentes, a capacidade das Câmaras Técnicas Estaduais e da área técnica do Ministério da Saúde no monitoramento dos benefícios clínicos e dos eventos adversos do fostensavir e a expectativa de uma nova proposta de preço encaminhada pela empresa durante a consulta pública. CONSULTA PÚBLICA: A consulta pública (CP) nº 69/2023 foi realizada entre os dias 29/12/2023 e 17/01/2024. Foram recebidas 11 contribuições, sendo sete pelo formulário para contribuições técnico-científico e quatro pelo formulário pra contribuições sobre experiência ou opinião de pacientes, familiares, amigos ou cuidadores de pacientes, profissionais de saúde ou pessoas interessadas no tema. Sobre as contribuições técnicas, todas foram favoráveis às recomendações preliminares da Conitec e uma possuía referencial teórico para a abordagem técnico-científica. Entretanto, não se identificou nenhuma evidência científica adicional que pudesse modificar o entendimento preliminar da Conitec. Nas contribuições de experiência ou opinião, todos os participantes manifestaram-se favoráveis à recomendação preliminar da tecnologia avaliada. Os argumentos relevantes foram classificados em "Sobrevida do paciente", uma vez que a abordagem foi especificamente quanto às falhas terapêuticas do uso de outros antirretrovirais e a evolução para complicações e óbito. Metade dos respondedores apontaram ter experiência com o fostensavir. No que diz respeito à experiência com outras tecnologias, um dos três respondentes, o paciente, mencionou o uso de medicamentos, como tenofovir, lamivudina, efavirenz e dolutegravir e apontou como evento negativo os seus efeitos colaterais. Além disso, destacaram o valor elevado da aquisição do fostensavir como uma das principais dificuldades para acesso a este tratamento. NOVA PROPOSTA COMERCIAL: Foi submetida ao DGITS/SECTICS/MS o valor de USD 38,67 por comprimido, com uma quantidade mínima de aquisição estabelecida em 360.000 (trezentos e sessenta mil) unidades. Considerando o novo valor proposto, o custo mensal do tratamento será de R$ 11.513,40, representando aproximadamente 65,59% de desconto em relação ao preço CMED PMVG 18% e uma redução de 1,66% em relação à proposta apresentada em 2023. Ainda com base no novo valor proposto, atualizou-se a avaliação econômica e a AIO. Os critérios considerados englobam os termos da recente proposta comercial e a taxa de câmbio do dólar no dia 15 de fevereiro de 2024, fixada em 1 USD = R$ 4,9624. A RCEI foi estimada em R$ 257.370,65, apresentando uma efetividade incremental de 0,54. No cenário conservador da nova AIO, levando em consideração uma participação de mercado de 10% ao ano, o impacto orçamentário incremental em cinco anos foi R$ 100.714.577,75. Já no cenário moderado, com um aumento de 20% após o primeiro ano, o impacto orçamentário acumulado em cinco anos foi R$ 247.300.234,85. RECOMENDAÇÃO FINAL DA CONITEC: Os membros do Comitê de Medicamentos presentes na 127ª Reunião Ordinária, realizada no dia 6 de março de 2024, deliberaram, por unanimidade, recomendar a incorporação do fostensavir trometamol 600 mg para o tratamento de indivíduos adultos vivendo com HIV multirresistentes aos antirretrovirais, conforme Protocolo Clínico do Ministério da Saúde. Considerou-se as expectativas da ampliação das opções terapêuticas e da redução da carga viral aos pacientes multirresistentes. Foi assinado o Registro de Deliberação nº 881/2024. DECISÃO: incorporar, no âmbito do Sistema Único de Saúde - SUS, o fostensavir trometamol 600 mg para o tratamento de indivíduos adultos vivendo com HIV multirresistente aos antirretrovirais, conforme Protocolo Clínico do Ministério da Saúde, publicada no Diário Oficial da União nº 77, seção 1, página 177, em 22 de abril de 2024.

RXR agonist, Bexarotene, effectively reduces drug resistance via regulation of RFX1 in embryonic carcinoma cells.

Aberrant expression of multidrug resistance (MDR) proteins is one of the features of cancer stem cells (CSCs) that make them escape chemotherapy. A well-orchestrated regulation of multiple MDRs by different transcription factors in cancer cells confers this drug resistance. An in silico analysis of the major MDR genes revealed a possible regulation by RFX1 and Nrf2. Previous reports also noted that Nrf2 is a positive regulator of MDR genes in NT2 cells. But we, for the first time, report that Regulatory factor X1 (RFX1), a pleiotropic transcription factor, negatively regulates the major MDR genes, Abcg2, Abcb1, Abcc1, and Abcc2, in NT2 cells. The levels of RFX1 in undifferentiated NT2 cells were found to be very low, which significantly increased upon RA-induced differentiation. Ectopic expression of RFX1 reduced the levels of transcripts corresponding to MDRs and stemness-associated genes. Interestingly, Bexarotene, an RXR agonist that acts as an inhibitor of Nrf2-ARE signaling, could increase the transcription of RFX1. Further analysis revealed that the RFX1 promoter has binding sites for RXRα, and upon Bexarotene exposure RXRα could bind and activate the RFX1 promoter. Bexarotene, alone or in combination with Cisplatin, could inhibit many cancer/CSC-associated properties in NT2 cells. Also, it significantly reduced the expression of drug resistance proteins and made the cells sensitive towards Cisplatin. Our study proves that RFX1 could be a potent molecule to target MDRs, and Bexarotene can induce RXRα-mediated RFX1 expression, therefore, would be a better chemo-assisting drug during therapy.

Resistencia antimicrobiana, una pandemia silenciosa / Antimicrobial resistance, a silent pandemic / Resistência antimicrobiana, uma pandemia silenciosa

Introducción: la resistencia a los antimicrobianos ha sido una problemática creciente a nivel global, la problemática afecta no solo la salud de personas, animales y el ambiente en general, sino que ha generado impactos de índole productivo y comercial. Una de las estrategias para abordar esta problemática es el enfoque de una salud. Este enfoque destaca la participación multidisciplinaria para combatir la resistencia antimicrobiana; y es así que cada profesión o actividad laboral genera unas responsabilidades innatas para la profesión veterinaria. Los veterinarios tienen un rol fundamental para este propósito, ya que son ellos quienes integran la aplicabilidad de estrategias de promoción y prevención a nivel agropecuario, y de consolidación e interlocución entre los diferentes componentes del enfoque (animal, humano, ambiente) desde el ámbito de la salud pública veterinaria. Materiales y Método: se realizó una búsqueda de la literatura en diferentes bases de datos, con el objetivo de realizar una revisión actualizada sobre la resistencia antimicrobiana. Resultados: dentro de las principales estrategias se debería fomentar un uso adecuado y bajo prescripción de antimicrobianos en la producción animal. Promover buenas prácticas de higiene, bioseguridad y vacunación, facilitando un correcto diagnóstico de enfermedades infecciosas en animales. Discusión: la adopción de normas internacionales para el uso responsable de los antibióticos y las directrices establecidas por la Organización Mundial de la Salud y Organización de las Naciones Unidas para la Alimentación y la Agricultura, a través del Codex Alimentarius y la Organización Mundial de Sanidad Animal, son fundamentales para hacer frente al desafío que representa el problema de la resistencia a los antimicrobianos.

Introduction: Antimicrobial resistance has been a growing problem at a global level, affecting not only the health of people, animals and the environment in general, but it has also generated impacts of a productive and commercial nature. One of the strategies to address this problem is the one-health approach. This approach emphasizes multidisciplinary participation to combat antimicrobial resistance; and thus, each profession or work activity generates innate responsibilities for the veterinary profession. Veterinarians have a fundamental role for this purpose, since they are the ones who integrate the applicability of promotion and prevention strategies at the agricultural level, and of consolidation and interlocution between the different components of the approach (animal, human, environment) from the field of veterinary public health. Materials and Method: a literature search was carried out in different databases, with the aim of carrying out an updated review on antimicrobial resistance. Results: one of the main strategies should be to promote an adequate use and under prescription of antimicrobials in animal production. Promote good hygiene, biosecurity and vaccination practices, facilitating a correct diagnosis of infectious diseases in animals. Discussion: the adoption of international standards for the responsible use of antibiotics and the guidelines established by the World Health Organization and the Food and Agriculture Organization of the United Nations, through Codex Alimentarius and the World Organization for Animal Health, are fundamental to face the challenge posed by the problem of antimicrobial resistance.

Introdução: A resistência antimicrobiana tem sido um problema crescente em todo o mundo, afetando não apenas a saúde dos seres humanos, dos animais e do meio ambiente em geral, mas também causando impactos na produção e no comércio. Uma das estratégias para lidar com esse problema é a abordagem One Health. Essa abordagem enfatiza o envolvimento multidisciplinar no combate à resistência antimicrobiana, com cada profissão ou atividade de trabalho gerando responsabilidades inatas à profissão veterinária. Os veterinários têm um papel fundamental nesse sentido, pois são eles que integram a aplicabilidade das estratégias de promoção e prevenção em nível agropecuário e de consolidação e interlocução entre os diferentes componentes da abordagem (animal, humano, ambiental) do campo da saúde pública veterinária. Materiais e Métodos: foi realizada uma pesquisa bibliográfica em diferentes bases de dados, com o objetivo de realizar uma revisão atualizada sobre a resistência antimicrobiana. Resultados: uma das principais estratégias deve ser a promoção do uso adequado e com baixa prescrição de antimicrobianos na produção animal. Promover boas práticas de higiene, biossegurança e vacinação, facilitando o diagnóstico correto de doenças infecciosas em animais. Discussão: A adoção de padrões internacionais para o uso responsável de antibióticos e as diretrizes estabelecidas pela Organização Mundial da Saúde e pela Organização das Nações Unidas para Agricultura e Alimentação, por meio do Codex Alimentarius e da Organização Mundial de Saúde Animal, são essenciais para enfrentar o desafio representado pelo problema da resistência antimicrobiana.

In Vitro Antibacterial and Phytochemical Screening of Hypericum perforatum Extract as Potential Antimicrobial Agents against Multi-Drug-Resistant (MDR) Strains of Clinical Origin.

Background: The perennial plant Hypericum perforatum is widely distributed around the world. It has been used for many years in conventional medicine to treat a variety of illnesses, including stress, mild to moderate depression, and minor injuries. This study examined the antimicrobial activity of the H. perforatum total extract and its fractions (n-hexane, ethyl acetate, chloroform, and aqueous) against multi-drug-resistant (MDR) isolates that were gathered from clinical samples, including methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Escherichia coli, and Klebsiella pneumonia. Materials and Methods: Aerial parts of H. perforatum were collected and extracted using various solvents and were tested versus different isolated bacterial species. The inhibition zone of tested extracts was detected using an agar diffusion assay, and MICs were measured. Phytochemical analysis of promising H. perforatum extract was done using LC-ESI-MS/MS. Ultrastructure examination for the most altered bacteria used transmission electron microscopy. Antioxidant assays were done using DPPH and ABTS scavenging capacity methods. Cytotoxicity was reported versus Vero cells. Results: Different extracts of H. perforatum showed promising antibacterial activity against the pathogens. While the subfractions of the total extract were observed to show lesser inhibition zones and higher MIC values than the total extract of H. perforatum against MDR strains, the total extract of H. perforatum demonstrated the most potent antimicrobial action with an inhibition zone range of 17.9-27.9 mm. MDR-K. pneumoniae was discovered to be the most susceptible strain, which is consistent with the antibacterial inhibitory action of H. perforatum whole extract. Additionally, after treatment at the minimum inhibitory concentration (MIC 3.9 µg/ml), the transmission electron microscope showed alterations in the ultrastructure of the K. pneumoniae cells. Methanol extract from H. perforatum has a CC50 value of 976.75 µg/ml. Conclusion: Future inhibitors that target MDR strains may be revealed by these findings. Additionally, the extracts that were put to the test demonstrated strong antioxidant effects as shown by DPPH or ABTS radical-scavenging assays.

Imidazo[1,2-a]Pyridine Derivatives as Novel Dual-Target Inhibitors of ABCB1 and ABCG2 for Reversing Multidrug Resistance.

ABCB1 and ABCG2 are the important ATP-binding cassette (ABC) transporters associated with multidrug resistance (MDR). Herein, we designed a series of imidazo[1,2-a]pyridine derivatives as dual-target inhibitors of ABCB1 and ABCG2 through the scaffold hopping strategy. Compound Y22 displayed potential efflux function inhibitory toward both ABCB1 and ABCG2 (reversal fold: ABCB1 = 8.35 and ABCG2 = 2.71) without obvious cytotoxicity. Y22 also enhanced the potency of antiproliferative drugs in vitro. Mechanistic studies demonstrated that Y22 slightly suppressed ATPase activity but did not affect the protein expression of ABCB1 or ABCG2. Notably, Y22 exhibited negligible CYP3A4 inhibition and enhanced the antiproliferative activity of adriamycin in vivo by restoring the sensitivity of resistant cells. Thus, Y22 may be effective clinically in combination with common chemotherapy agents. In summary, Y22 is a potential dual-target inhibitor that reverses MDR by blocking the efflux function of ABCB1 and ABCG2.

Tetrandrine overcomes drug resistance mediated by bone marrow microenvironment by regulating the expression of P-glycoprotein in acute leukemia.

Objectives: To study the effect of TET on the reversal of drug resistance in the bone marrow microenvironment, and to further promote the research on drug reversal.Methods: We established a co-culture system of bone marrow mesenchymal stem cells (BM-MSC) and K562 cell lines, and compared the cell inhibition rate of K562 cells between the co-culture group and K562 singleculture group by daunorubicin (DNR) single-drug intervention with CCK-8 and also compared K562 proliferation in the co-culture group and K562 single-culture group after combined intervention with DNR and TET, then used Western blot and RT-qPCR to verify the expression of P-gp of K562 cells at protein and mRNA levels, confirmed the concentration of DNR in K562 of different experimental groups by HPLC-MS.Results: According to the results of CCK-8, after co-culture with bone marrow mesenchymal stem cells (BM-MSCs), the inhibition rate of DNR on K562 decreased significantly. When TET (1µmol/L) combined with daunorubicin (DNR) treated on the co-culture group, the inhibition rate increased significantly. Then, the results of RT-qPCR and western blot showed a remarkable difference of the expression of P-glycoprotein (P-gp). After co-culture with BM-MSCs, the protein expression of P-gp showed a significant upward trend. After adding TET intervention, the expression of P-gp decreased both in mRNA and protein levels. Also, the DNR concentration in K562 also performed the correspondent trend.Conclusion: The bone marrow microenvironment can promote the MDR of acute leukemia. TET can reverse the MDR mediated by the bone marrow microenvironment by inhibiting the expression of P-glycoprotein.