Synergy of Histone Acetyltransferase Inhibitor (HATi) with Quercetin Inhibits Biofilm Formation in Candida tropicalis.

Histone acetyltransferase inhibitors (HATi) are mechanism-based inhibitors that show promise in the treatment of several illnesses, including diabetes, hyperlipidemia, cancer, and Alzheimer's disease. The work emphasizes the significance of HATi as a possible treatment strategy against Candida species biofilms. Here, in this study, we found that combining a HATi, anacardic acid, and quercetin, a known flavonoid, significantly prevented biofilm formation by C. tropicalis. We further show that C. tropicalis exhibited a considerable downregulation of drug-resistance gene expression (CDR1 and MDR1) when co-administrated. Additionally, in silico studies revealed that the anacardic acid (AA) interacts strongly with a histone acetyltransferase, Rtt109, which may account for the observed biofilm inhibitory effect. In conclusion, the study illustrates how HATi may be used to potentiate the inhibitory action of phytoactives or antifungals against drug-resistant yeast infections.

Assessing the therapeutic efficacy of artemether-lumefantrine for uncomplicated malaria in Lagos, Nigeria: a comprehensive study on treatment response and resistance markers.

BACKGROUND: The burden of malaria persists in sub-Saharan Africa and the emergence of artemisinin resistance has introduced complexity to control efforts. Monitoring the efficacy of artemisinin-based treatment for malaria is crucial to address this challenge. This study assessed treatment efficacy of artemether-lumefantrine (AL) and genetic diversity of Plasmodium falciparum isolates in a Nigerian population. METHODS: Participants presenting with clinical symptoms of uncomplicated malaria at a health centre in Lagos, Nigeria, were screened for P. falciparum. Enrolled participants were treated with AL and monitored through scheduled check-up visits, clinical and laboratory examinations for 28 days. Parasite clearance and genetic diversity were assessed through polymerase chain reaction (PCR) analysis of merozoite surface proteins (msp1 and msp2). The prevalence of drug resistance mutations was assessed by P. falciparum multidrug resistance gene 1 (mdr1) genotyping followed by P. falciparum ubiquitin-specific protease 1 (ubp1) gene sequencing. RESULTS: The PCR-uncorrected treatment outcome revealed 94.4% adequate clinical and parasitological response (ACPR) and 5.6% late parasitological failure (LPF) rates. After PCR correction, no suspected LPF case was detected and ACPR 67/67 (100%) was achieved in all the individuals. Moreover, a high prevalence of wild-type alleles for mdr1 N86Y (93.7%), and mdr1 D1246Y (87.5%) was observed. Genetic diversity analysis revealed predominant K1 allelic family for msp1 (90.2%) and FC27 for msp2 (64.4%). Estimated multiplicity of infection (MOI) was 1.7, with the highest MOI observed in the 5-15 years age group. ubp1 sequence analysis identified one nonsynonymous E1528D polymorphism at a low frequency (1.6%). CONCLUSION: The study demonstrated sustained efficacy of AL for treating uncomplicated P. falciparum malaria. Genetic diversity analysis revealed various allelic types, suggesting occurrences of polyclonal infections. Nonetheless, the detection of a significant ubp1 polymorphism could have future implications for the epidemiology of anti-malarial drug resistance in the population.

Effect of MDR1 C3435T and CYP2C19 genetic polymorphisms on the outcome of Helicobacter pylori eradication treatment in children with gastritis and peptic ulcer, Vietnam.

BACKGROUND: Helicobacter pylori eradication therapy based on antimicrobial susceptibility in Vietnamese children currently get low efficiency. There are causes of treatment failure, among host genetic factors namely MDR1 C3435T and CYP2C19 affect the absorption and metabolism of proton pump inhibitors - a crucial component of eradication therapy. The study aimed to investigate the effect of MDR1 C3435T and CYP2C19 genetic polymorphisms on the cure rate. METHODS: 207 pediatric patients with gastritis and peptic ulcer infecting Helicobacter pylori completed the eradication therapy based on antimicrobial susceptibility with proton pump inhibitor esomeprazole. Eradication efficacy was assessed after at least 4 weeks by the urease breath test. MDR1 C3435T genetic polymorphism and CYP2C19 genotype were determined using a sequencing method based on Sanger's principle. RESULTS: Among 207 children recruited in this study, the ratio of CYP2C19 EM, IM, and PM phenotypes was 40.1%, 46.4%, and 16.9%, respectively. The patient with MDR1 3435 C/C polymorphism accounted for 43.0%, MDR1 3435 C/T was 40.1%, and MDR1 3435T/T was 16.9%. The cure rate of Helicobacter pylori infection in patients with CYP2C19 EM genotype was 78.3%; 83.3% of those with the IM genotype, and PM genotype was 96,4% (p = 0.07). Successful eradication rates for Helicobacter pylori were 85.4%, 86.7%, and 68.6% in patients with the MDR1 3435 C/C, C/T, and T/T, respectively (p = 0.02). Multiple logistic regression analysis found that MDR1 C3435T genetic polymorphisms of patients were significant independent risk factors for treatment failure, and CYP2C19 genotype did not affect Helicobacter pylori eradication. CONCLUSIONS: The Helicobacter pylori eradication rates by regimens based on antibiotic susceptibility and esomeprazole were not significantly different between the CYP2C19 phenotypes. The MDR1 C3435T polymorphism is one of the factors impacting Helicobacter pylori eradication results in children.

Effect of ABCB1 most frequent polymorphisms on the accumulation of bictegravir in recombinant HEK293 cell lines.

Bictegravir, a key second-generation integrase strand transfer inhibitor in the treatment of HIV, is subject to active efflux transport mediated by ABCB1 (P-glycoprotein). Several coding variants of ABCB1 have been described and associated with variable effects on substrate drugs pharmacokinetics. Here, we investigated the effect of the four most common coding ABCB1 single nucleotide polymorphisms (i.e., c.1199G > A, c.1236C > T, c.2677G > T and c.3435C > T) on the intracellular accumulation of bictegravir. Using a previously validated HEK293 recombinant cell line model, we found decreased bictegravir intracellular concentrations in cell lines overexpressing ABCB1 as compared to control cell lines, in line with the known role of ABCB1 in bictegravir transport. However, we were unable to demonstrate any significant difference in bictegravir intracellular accumulation when comparing HEK293 cells overexpressing the wild type (1236C-2677G-3435C, 1199G) or the variant (1236C-2677G-3435T, 1236T-2677T-3435T or 1199A) proteins. These findings suggest that the ABCB1 c.1199G > A and c.1236C > T-c.2677G > T-c.3435C > T variants have no or at least limited impact on the active transport of bictegravir by ABCB1.

A descriptive study of the single-nucleotide polymorphisms known to affect the Tacrolimus trough concentration per dose, among a population of kidney failure patients in a tertiary hospital in Ghana.

BACKGROUND: The burden of chronic kidney disease (CKD) and kidney failure in Ghana is on the ascendency, with the prevalence of CKD estimated at 13.3%. Patients with CKD who progress to kidney failure require life sustaining kidney replacement therapy (KRT) which is almost exclusively available in Ghana as haemodialysis. Kidney transplantation is considered the best KRT option for patients with irreversible kidney failure due to its relative cost efficiency as well as its superiority in terms of survival and quality of life. However, because transplants may trigger an immune response with potential organ rejection, immunosuppressants such as tacrolimus dosing are required. OBJECTIVE: This study sought to determine single nucleotide polymorphisms in CYP3A5, CYP3A4 and MDR1 genes that affect the pharmacokinetics of Tacrolimus in a population of Ghanaian patients with kidney failure. METHOD: This cross-sectional study comprised of 82 kidney failure patients undergoing maintenance haemodialysis at the Renal and Dialysis unit of Korle-Bu Teaching Hospital (KBTH). Clinical and demographic data were collected and genomic DNA isolated. Samples were genotyped for specific SNPs using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). RESULTS: Participants, 58/82 (70.73%) harbored the wildtype CYP3A5*1/*1 AA genotype, 20/82 (24.39%) carried the heterozygous CYP3A5*1/*3 AG genotype, and 4/82 (4.88%) had the homozygous mutant CYP3A5*3/*3 GG genotype. Also, 6/82 (7.32%) carried the wildtype AA genotype, 11/82 (13.41%) had the heterozygous AG genotype, and 65/82 (79.27%) harbored the homozygous mutant GG genotype of CYP3A4*1B (-290 A>G). For MDR1_Ex21 (2677 G>T), 81/82 (98.78%) carried the wildtype GG genotype, while 1/82 (1.22%) had the heterozygous GT genotype. For MDR1_Ex26 (3435 C>T), 63/82 (76.83%) had the wildtype CC genotype, while 18/82 (21.95%) carried the heterozygous CT genotype, and 1/82 (1.22%) harbored the mutant TT genotype. CONCLUSION: SNPs in CYP3A4, CYP3A5, and MDR1 genes in a population of Ghanaian kidney failure patients were described. The varying SNPs of the featured genes suggest the need to consider the genetic status of Ghanaians kidney failure patients prior to transplantation and tacrolimus therapy.

Role of ERG11 and MDR1 genes in cycloheximide and multidrug resistance in Candida species.

Candida species are amongst the commensals of the mucosal surfaces of the human body which include the oral cavity, vagina, and intestinal mucosa. Fungal infections are on the rise worldwide. The overall burden of infections due to fungi is difficult to estimate because the majority of them remain undiagnosed. The present study aims to determine the burden of antifungal resistance in low socioeconomic country, Pakistan and the frequency of ERG11 and MDR1 genes involved. A total of 636 Candida isolates were obtained from various tertiary care institutions in Lahore in the form of culture on various culture plates. Sabouraud agar culture plates were used to culture the Candida spp. Antifungal resistance was determined against Fluconazole, Itraconazole, Ketoconazole, and Nystatin via disk diffusion technique. Most resistance was observed against Fluconazole followed by Itraconazole, Ketoconazole, and Nystatin. The Candida isolates recovering from CVP tip and tissue have a high resistance profile. Candida species resistant to at least two antifungals were chosen for further ERG11 and MDR1 detection through real-time PCR. Among 255 Candida isolates, 240 contained ERG11 gene while MDR1 gene is present in 149 Candida isolates. The isolates carrying both genes were tested by the broth microdilution technique for the susceptibility against cycloheximide, all of them were able to grow in cycloheximide. The genetic determinants of antifungal resistance such as ERG11 and MDR1 are as important in the multidrug resistance against a variety of compounds and antifungal drugs.

Identification of exosomal microRNAs and related hub genes associated with imatinib resistance in chronic myeloid leukemia.

Chemotherapy resistance is a major obstacle in cancer therapy, and identifying novel druggable targets to reverse this phenomenon is essential. The exosome-mediated transmittance of drug resistance has been shown in various cancer models including ovarian and prostate cancer models. In this study, we aimed to investigate the role of exosomal miRNA transfer in chronic myeloid leukemia drug resistance. For this purpose, firstly exosomes were isolated from imatinib sensitive (K562S) and resistant (K562R) chronic myeloid leukemia (CML) cells and named as Sexo and Rexo, respectively. Then, miRNA microarray was used to compare miRNA profiles of K562S, K562R, Sexo, Rexo, and Rexo-treated K562S cells. According to our results, miR-125b-5p and miR-99a-5p exhibited increased expression in resistant cells, their exosomes, and Rexo-treated sensitive cells compared to their sensitive counterparts. On the other hand, miR-210-3p and miR-193b-3p were determined to be the two miRNAs which exhibited decreased expression profile in resistant cells and their exosomes compared to their sensitive counterparts. Gene targets, signaling pathways, and enrichment analysis were performed for these miRNAs by TargetScan, KEGG, and DAVID. Potential interactions between gene candidates at the protein level were analyzed via STRING and Cytoscape software. Our findings revealed CCR5, GRK2, EDN1, ARRB1, P2RY2, LAMC2, PAK3, PAK4, and GIT2 as novel gene targets that may play roles in exosomal imatinib resistance transfer as well as mTOR, STAT3, MCL1, LAMC1, and KRAS which are already linked to imatinib resistance. MDR1 mRNA exhibited higher expression in Rexo compared to Sexo as well as in K562S cells treated with Rexo compared to K562S cells which may suggest exosomal transfer of MDR1 mRNA.

Applicability of MDR1 Overexpressing Abcb1KO-MDCKII Cell Lines for Investigating In Vitro Species Differences and Brain Penetration Prediction.

Implementing the 3R initiative to reduce animal experiments in brain penetration prediction for CNS-targeting drugs requires more predictive in vitro and in silico models. However, animal studies are still indispensable to obtaining brain concentration and determining the prediction performance of in vitro models. To reveal species differences and provide reliable data for IVIVE, in vitro models are required. Systems overexpressing MDR1 and BCRP are widely used to predict BBB penetration, highlighting the impact of the in vitro system on predictive performance. In this study, endogenous Abcb1 knock-out MDCKII cells overexpressing MDR1 of human, mouse, rat or cynomolgus monkey origin were used. Good correlations between ERs of 83 drugs determined in each cell line suggest limited species specificities. All cell lines differentiated CNS-penetrating compounds based on ERs with high efficiency and sensitivity. The correlation between in vivo and predicted Kp,uu,brain was the highest using total ER of human MDR1 and BCRP and optimized scaling factors. MDR1 interactors were tested on all MDR1 orthologs using digoxin and quinidine as substrates. We found several examples of inhibition dependent on either substrate or transporter abundance. In summary, this assay system has the potential for early-stage brain penetration screening. IC50 comparison between orthologs is complex; correlation with transporter abundance data is not necessarily proportional and requires the understanding of modes of transporter inhibition.

Emerging Role of ABC Transporters in Glia Cells in Health and Diseases of the Central Nervous System.

ATP-binding cassette (ABC) transporters play a crucial role for the efflux of a wide range of substrates across different cellular membranes. In the central nervous system (CNS), ABC transporters have recently gathered significant attention due to their pivotal involvement in brain physiology and neurodegenerative disorders, such as Alzheimer's disease (AD). Glial cells are fundamental for normal CNS function and engage with several ABC transporters in different ways. Here, we specifically highlight ABC transporters involved in the maintenance of brain homeostasis and their implications in its metabolic regulation. We also show new aspects related to ABC transporter function found in less recognized diseases, such as Huntington's disease (HD) and experimental autoimmune encephalomyelitis (EAE), as a model for multiple sclerosis (MS). Understanding both their impact on the physiological regulation of the CNS and their roles in brain diseases holds promise for uncovering new therapeutic options. Further investigations and preclinical studies are warranted to elucidate the complex interplay between glial ABC transporters and physiological brain functions, potentially leading to effective therapeutic interventions also for rare CNS disorders.

Digestion of surfactants does not affect their ability to inhibit P-gp-mediated transport in vitro.

While various non-ionic surfactants at low concentrations have been shown to increase the transport of P-gp substrates in vitro, in vivo studies in rats have shown that a higher surfactant concentration is needed to increase the oral absorption of e.g. the P-gp substrates digoxin and etoposide. The aim of the present study was to investigate if intestinal digestion of surfactants could be the reason for this deviation between in vitro and in vivo data. Therefore, Kolliphor EL, Brij-L23, Labrasol and polysorbate 20 were investigated for their ability to inhibit P-gp and increase digoxin absorption in vitro. Transport studies were performed in Caco-2 cells, while P-gp inhibition and cell viability assays were performed in MDCKII-MDR1 cells. Polysorbate 20, Kolliphor EL and Brij-L23 increased absorptive transport and decreased secretory digoxin transport in Caco-2 cells, whereas only polysorbate 20 and Brij-L23 showed P-gp inhibiting properties in the MDCKII-MDR1 cells. Polysorbate 20 and Brij-L23 were chosen for in vitro digestion prior to transport- or P-gp inhibiting assays. Brij-L23 was not digestible, whereas polysorbate 20 reached a degree of digestion around 40%. Neither of the two surfactants showed any significant difference in their ability to affect absorptive or secretory transport of digoxin after pre-digestion. Furthermore, the P-gp inhibiting effects of polysorbate 20 were not decreased significantly. In conclusion, the mechanism behind the non-ionic surfactant mediated in vitro P-gp inhibition seemed independent of the intestinal digestion and the results presented here did not suggest it to be the cause of the observed discrepancy between in vitro and in vivo.

Up-regulation of CDR1 and MDR1 efflux pump genes and fluconazole resistance are involved in recurrence in Candida albicans-induced vulvovaginal candidiasis.

Recurrent vulvovaginal candidiasis (RVVC) due to fluconazole resistance in Candida albicans isolates causes a wide range of complications. A number of 63 Candida albicans isolates obtained from vulvovaginal candidiasis (VVC) were identified by Internal Transcribed Spacer-Restriction Fragment Length Polymorphism (ITS-RFLP). Antifungal susceptibility testing was performed by broth microdilution method according to the CLSI protocol. The role of CDR1 and MDR1 genes in progress of VVC to RVVC was examined and the activity of virulence-related enzymes was assessed. Candida albicans was diagnosed in 62.4 % cases, of which 22.2 % were confirmed as RVVC. Voriconazole was the most active drug among five tested antifungals. The mean expression level of CDR1 and MDR1 was higher in RVVC isolates compared to multidrug azole-resistant VVC isolates. Our results demonstrated that the expression of CDR1 and MDR1 and the level of phospholipase and proteinase activities could be quite important to induce fluconazole resistance in C. albicans and to progress of VVC to become RVVC in involved patients.

Combination drug therapy by herbal nanomedicine prevent multidrug resistance protein 1: promote apoptosis in Lung Carcinoma.

Given the numerous adverse effects of lung cancer treatment, more research on non-toxic medications is urgently needed. Curcumin (CUR) and berberine (BBR) combat drug resistance by controlling the expression of multidrug resistant pump (MDR1). Fascinatingly, combining these medications increases the effectiveness of preventing lung cancer. Their low solubility and poor stability, however, restrict their therapeutic efficacy. Because of the improved bioavailability and increased encapsulation effectiveness of water-insoluble medicines, surfactant-based nanovesicles have recently received a great deal of attention. The current study sought to elucidate the Combination drug therapy by herbal nanomedicine prevent multidrug resistance protein 1: promote apoptosis in Lung Carcinoma. The impact of several tween (20, 60, and 80) types with varied hydrophobic tails on BBR/CUR-TNV was evaluated. Additionally, the MDR1 activity and apoptosis rate of the BBR/CUR-TNV combination therapy were assessed. The encapsulation effectiveness of TNV was affected by the type of tween. With the TNV made from tween 60, cholesterol, and PEG (47.5: 47.5:5), more encapsulation effectiveness was attained. By combining CUR with BBR, especially when given in TNV, apoptosis increased. Additionally, when CUR and BBR were administered in combination, they significantly reduced the risk of MDR1 development. The current work suggests that the delivery of berberine and curcumin as a combination medication therapy via tween-based nanovesicles may be a potential lung cancer treatment.

The roles of ABCB1/P-glycoprotein drug transporters in regulating gut microbes and inflammation: insights from animal models, old and new.

Commensal enteric bacteria have evolved systems that enable growth in the ecologic niche of the host gastrointestinal tract. Animals evolved parallel mechanisms to survive the constant exposure to bacteria and their metabolic by-products. We propose that drug transporters encompass a crucial system to managing the gut microbiome. Drug transporters are present in the apical surface of gut epithelia. They detoxify cells from small molecules and toxins (xenobiotics) in the lumen. Here, we review what is known about commensal structure in the absence of the transporter ABCB1/P-glycoprotein in mammalian models. Knockout or low-activity alleles of ABCB1 lead to dysbiosis, Crohn's disease and ulcerative colitis in mammals. However, the exact function of ABCB1 in these contexts remain unclear. We highlight emerging models-the zebrafish Danio rerio and sea urchin Lytechinus pictus-that are poised to help dissect the fundamental mechanisms of ATP-binding cassette (ABC) transporters in the tolerance of commensal and pathogenic communities in the gut. We and others hypothesize that ABCB1 plays a direct role in exporting inflammatory bacterial products from host epithelia. Interdisciplinary work in this research area will lend novel insight to the transporter-mediated pathways that impact microbiome community structure and accelerate the pathogenesis of inflammatory bowel disease when perturbed. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Valproate modulates the activity of multidrug resistance efflux pumps, as a chemoresistance factor in gastric cancer cells.

BACKGROUND: Drug resistance is one of the most critical problems in gastric cancer therapy. This study was performed to investigate the valproic acid effects on the proliferation of sensitive and resistant cell lines of human gastric cancer, and to explore the mechanism of the agent on multi drug resistance and apoptosis genes. METHODS: The cytotoxicity effect of valproic acid on the EPG85.257 and EPG85.257RDB cells was assessed by the MTT assay, and the IC50 concentration was evaluated. Apoptosis, genotoxicity, and drug resistance pump activity were evaluated using comet assay, Real-time PCR, and flow cytometry, respectively. Cell proliferation was assayed using a scratch test. RESULTS: Dose-dependent toxicity was recorded after treatment of cells with valproic acid. Valproic acid represented a significant growth inhibition on EPG85.257 cells with IC50 values of 5.84 µM and 4.78 µM after 48 h and 72 h treatment, respectively. In contrast, the drug-resistant counterpart represented 8.7 µM and 7.02 µM IC50 values after the same treatment time. Valproic acid induced PTEN, Bcl2, P53, Bax, P21, and caspase3 expression in EPG85.257 cells, whereas p21, p53, PTEN, and ABCB1 were overexpressed in EPG5.257RDB. Valproic acid hindered cell migration in both cell lines (P < 0.01). Valproate genotoxicity was significantly higher in the parent cells than in their resistant EPG85.257RDB counterparts. Valproate led to a 62% reduction in the daunorubicin efflux of the MDR1 pump activity. CONCLUSIONS: Valproate can affect drug resistance in gastric cancer via a unique mechanism independent of MDR1 expression.

4-{3-[(Pyridin-4-ylmethyl)amino]-[1,2,4]triazolo[4,3-b][1,2,4]triazin-6-yl}phenol: An improved anticancer agent in hepatocellular carcinoma and a selective MDR1/MRP modulator.

Hepatocellular carcinoma is the most common type of primary liver cancer. However, multidrug resistance (MDR) is a major obstacle to the effective chemotherapy of cancer cells. This report documents the rational design, synthesis, and biological evaluation of a novel series of triazolotriazines substituted with CH2NH-linked pyridine for use as dual c-Met/MDR inhibitors. Compound 12g with IC50 of 3.06 µM on HepG2 cells showed more potency than crizotinib (IC50 = 5.15 µM) in the MTT assay. In addition, 12g inhibited c-Met kinase at a low micromolar level (IC50 = 0.052 µM). 12g significantly inhibited P-gp and MRP1/2 efflux pumps in both cancerous HepG2 and BxPC3 cells starting from the lower concentrations of 3 and 0.3 µM, respectively. 12g did not inhibit MDR1 and MRP1/2 in noncancerous H69 cholangiocytes up to the concentration of 30 and 60 µM, respectively. Current results highlighted that cancerous cells were more susceptible to the effect of 12g than normal cells, in which the inhibition occurred only at the highest concentrations, suggesting a further interest in 12g as a selective anticancer agent. Overall, 12g, as a dual c-Met and P-gp/MRP inhibitor, is a promising lead compound for developing a new generation of anticancer agents.

Association of Chemotherapy Response Score with Multidrug Resistance 1 and CA125 ELIMination Rate Constant K in Patients with Advanced Ovarian Cancer Treated with Neoadjuvant Chemotherapy.

AIM: The relationship between chemotherapy response score (CRS), a widely used response predictor of neoadjuvant chemotherapy-interval debulking surgery (NAC-IDS), and multidrug resistance 1 (MDR1) and CA125 ELIMination rate constant K (KELIM), is undetermined. We evaluated CRS in advanced ovarian cancer patients undergoing NAC and looked for associations between CRS and MDR1 and CA125 KELIM. Our aim was to predict the therapeutic effect of NAC before interval debulking surgery (IDS) by examining its association with CRS. METHODS: This retrospective cohort study included patients who underwent NAC-IDS (first-line treatment) at Kurume University Hospital, Japan, between 2004 and 2017. CRS association with MDR1 and CA125 KELIM was examined using Cox proportional hazard regression analyses. Survival curves used Kaplan-Meier method, and survival differences between groups used log-rank test. RESULTS: Overall, 55 patients were classified into CRS1 (n=22), CRS2 (n=19), and CRS3 (n=14). The CRS3 group had a significantly better prognosis than the CRS1 or CRS2 group. CRS, age, and IDS status were clinical prognostic factors for ovarian cancer. MDR1 positivity for excision repair cross-complementing group 1, ß-tubulin, and Y-box binding protein-1 occurred in 15, 17, and 11 patients, respectively, but these were not associated with CRS. CA125 KELIM was <0.5 (n=8), 0.5-1.0 (n=30), and ≥ 1.0 (n=17) but not associated with CRS. CONCLUSION: CRS is reconfirmed as a treatment response predictor for NAC-IDS, but its association with drug resistance factors remains unconfirmed.

Cholesterol Conjugates of Small Interfering RNA: Linkers and Patterns of Modification.

Cholesterol siRNA conjugates attract attention because they allow the delivery of siRNA into cells without the use of transfection agents. In this study, we compared the efficacy and duration of silencing induced by cholesterol conjugates of selectively and totally modified siRNAs and their heteroduplexes of the same sequence and explored the impact of linker length between the 3' end of the sense strand of siRNA and cholesterol on the silencing activity of "light" and "heavy" modified siRNAs. All 3'-cholesterol conjugates were equally active under transfection, but the conjugate with a C3 linker was less active than those with longer linkers (C8 and C15) in a carrier-free mode. At the same time, they were significantly inferior in activity to the 5'-cholesterol conjugate. Shortening the sense strand carrying cholesterol by two nucleotides from the 3'-end did not have a significant effect on the activity of the conjugate. Replacing the antisense strand or both strands with fully modified ones had a significant effect on silencing as well as improving the duration in transfection-mediated and carrier-free modes. A significant 78% suppression of MDR1 gene expression in KB-8-5 xenograft tumors developed in mice promises an advantage from the use of fully modified siRNA cholesterol conjugates in combination chemotherapy.

EGR1 mediates MDR1 transcriptional activity regulating gemcitabine resistance in pancreatic cancer.

BACKGROUND: Gemcitabine is a cornerstone drug for the treatment of all stages of pancreatic cancer and can prolong the survival of patients with pancreatic cancer, but resistance to gemcitabine in pancreatic cancer patients hinders its efficacy. The overexpression of Early growth response 1(EGR1) in pancreatic ductal adenocarcinoma as a mechanism of gemcitabine chemoresistance in pancreatic cancer has not been explored. The major mechanisms of gemcitabine chemoresistance are related to drug uptake, metabolism, and action. One of the common causes of tumor multidrug resistance (MDR) to chemotherapy in cancer cells is that transporter proteins increase intracellular drug efflux and decrease drug concentrations by inducing anti-apoptotic mechanisms. It has been reported that gemcitabine binds to MDR1 with high affinity. The purpose of this research was to investigate the potential mechanisms by which EGR1 associates with MDR1 to regulate gemcitabine resistance in pancreatic cancer cells. METHODS: The following in vitro and in vivo techniques were used in this research to explore the potential mechanisms by which EGR1 binds to MDR1 to regulate gemcitabine resistance in pancreatic cancer cells. Cell culture; in vitro and in vivo study of EGR1 function by loss of function analysis. Binding of EGR1 to the MDR1 promoter was detected using the ChIP assay. qRT-PCR, Western blot assays to detect protein and mRNA expression; use of Annexin V apoptosis detection assay to test apoptosis; CCK8, Edu assay to test cell proliferation viability. The animal model of pancreatic cancer subcutaneous allograft was constructed and the tumours were stained with hematoxylin eosin and Ki-67 expression was detected using immunohistochemistry. FINDINGS: We revealed that EGR1 expression was increased in different pancreatic cancer cell lines compared to normal pancreatic ductal epithelial cells. Moreover, gemcitabine treatment induced upregulation of EGR1 expression in a dose- and time-dependent manner. EGR1 is significantly enriched in the MDR1 promoter sequence.Upon knockdown of EGR1, cell proliferation was impaired in CFPAC-1 and PANC-1 cell lines, apoptosis was enhanced and MDR1 expression was decreased, thereby partially reversing gemcitabine chemoresistance. In animal experiments, knockdown of EGR1 enhanced the inhibitory effect of gemcitabine on tumor growth compared with the sh-NC group. CONCLUSIONS: Our study suggests that EGR1 may be involved in the regulation of MDR1 to enhance gemcitabine resistance in pancreatic cancer cells. EGR1 could be a novel therapeutic target to overcome gemcitabine resistance in pancreatic cancer.

Multidrug resistance Gene-1 polymorphisms (C3435T and G2677T) and the risk of inflammatory bowel disease in Egyptian patients.

BACKGROUND AND STUDY AIMS: The multidrug resistance 1 (MDR1) gene is a gene involved in the pathogenesis of inflammatory bowel disease (IBD).The aim of the study is to investigate the association of MDR-1 gene polymorphisms (C2345T and G2677T) and IBD incidence in Egyptian patients, and its relation with disease severity. PATIENTS AND METHODS: This is a case-control study where genotyping of MDR-1 gene C3435T and G2677T single nucleotide polymorphisms (SNPs) were assayed. RESULTS: Forty naïve IBD patients, who were composed of 25 UC and 15CD, were compared to 60 healthy controls. They were young aged with significant female predominance, particularly in CD (P = 0.004). UC was mainly (48 %) presented in moderate severity while CD was mainly (53.3 %) presented with mild severity. MDR-1 gene C3435T SNP was not statistically related to IBD, whether in terms of genotypes or alleles, yet its T allele was significantly related to moderate cases of UC (P = 0.014). However, GG genotype of G2677T SNP was significantly low in IBD (P = 0.013), while TT genotype and T allele were significantly related to CD (P = 0.011, and 0.012 respectively). Moreover, G allele proved to be associated significantly with moderate cases of UC (P = 0.001) and mild cases of CD (P = 0.002). CONCLUSIONS: MDR-I gene G2677T SNP GG genotype proved to be protective against IBD, thus may be considered in diagnostic workup of IBD including its severity.

In ovarian cancer maraviroc potentiates the antitumoral activity and further inhibits the formation of a tumor-promoting microenvironment by trabectedin.

Ovarian cancer (OC) is the fifth most frequent cause of cancer-related death in women. Chemotherapy agent trabectedin, affecting cancer cells and tumor microenvironment, has been approved for the treatment of relapsed platinum-sensitive OC patients. CCR5-antagonist maraviroc inhibits tumor growth, metastasis, and enhances the antitumoral activity of DNA-damaging drugs. Here, we found that OC cells expressed CCR5 receptor but did not secret CCR5-ligands. Maraviroc treatment did not affect OC cell viability, but strongly potentiated the antiproliferative activity, apoptosis induction, cell cycle blockage, DNA damage, and ROS formation by trabectedin. In A2780cis cisplatin-resistant cells, the cross-resistance to trabectedin was overcame by the combination with maraviroc. Maraviroc enhanced trabectedin cytotoxicity in OC 3Dimensional spheroids and THP-1-monocytes. Both maraviroc and trabectedin interact with drug efflux pump MDR1/P-gp, overexpressed in recurrent OC patients. Maraviroc increased trabectedin intracellular accumulation and the MDR1-inhibitor verapamil, like maraviroc, increased trabectedin cytotoxicity. In OC tumor xenografts the combination with maraviroc further reduced tumor growth, angiogenesis, and monocyte infiltration by trabectedin. In conclusion, this study offers a preclinical rationale for the use of maraviroc as new option to improve trabectedin activity in relapsed chemoresistant OC patients.