Discovery of oral chemotherapeutic reversal agents for treating multidrug resistance cancer.

The major limitation of cancer treatment is multidrug resistance (MDR), which leads to the inactivation of chemotherapeutic drugs and greater than 90% mortality. To solve this ordeal, we applied ligand-based drug design and bioiosteric replacement strategy from an indazole to a pyrazole ring to discover compounds 27 and 43 with good potential for reversing drug resistance in combination with paclitaxel, and their reversal fold values were 53.2 and 51.0 at 5 µM, respectively, against an MDR cancer cell line (KBvin). Based on the PK profile results, we selected compound 43 with a longer half-life for mechanistic and animal experiments. Combination treatment with compound 43 and paclitaxel-induced apoptosis and enhanced subG1 by decreasing mitochondrial membrane potential in KBvin cells. In addition, 43 also inhibited P-gp function by interfering with ATPase activity. Meanwhile, cotreatment with compound 43 and paclitaxel significantly suppressed tumor growth (TGI = 55.5%) at a dose of 200 mg/kg (PO) in a xenograft model and showed no obvious liver or kidney toxicity by H&E staining. Overall, compound 43 may serve as a safe and effective oral resistance reversal chemotherapeutic agent.

Mosloflavone from Fissistigma petelotii ameliorates oncogenic multidrug resistance by STAT3 signaling modulation and P-glycoprotein blockade.

BACKGROUND: Oncogenic multidrug resistance (MDR) is a tough question in cancer therapy. However, no effective medications targeting oncogenic MDR are currently available. Studies have demonstrated that mosloflavone exerts anti-inflammatory effects, yet, its potential to ameliorate MDR remains unclear. PURPOSE: This study aimed to access the capability and elucidate molecular mechanisms of mosloflavone as a MDR resensitizing candidate. METHODS: We investigated the ability of mosloflavone to reverse oncogenic MDR and investigated its underlying mechanisms through cytotoxicity assay, cell cycle assay, apoptosis assay, and zebrafish xenograft model. The modulatory interplay between mosloflavone and P-gp was investigated through analysis of calcein-AM uptake, substrate efflux, ATPase assays, and molecular docking simulation. RESULTS: Mosloflavone inhibited P-gp efflux function in an uncompetitive manner without altering ABCB1 gene expression. In addition, it stimulated P-gp ATPase activity by binding to an active site distinct from that of verapamil. Regarding MDR reversal potential, mosloflavone resensitized MDR cancer cells to chemotherapies by arresting cell cycle and triggering apoptosis, possibly by enhancing reactive oxygen species accumulation and reducing phospho-STAT3. Moreover, in the zebrafish xenograft model, mosloflavone significantly potentiated the antitumor effect of paclitaxel. CONCLUSION: Our findings underscore the potential of mosloflavone as a novel dual modulator of STAT3 and P-gp, indicating it is a promising candidate for overcoming MDR in cancer treatment.

Novel (-)-arctigenin derivatives inhibit signal transducer and activator of transcription 3 phosphorylation and P-glycoprotein function resensitizing multidrug resistant cancer cells in vitro and in vivo.

Multidrug resistance (MDR) is considered one of the significant chemotherapy failures of cancer patients and resulting in tumor recurrence and refractory cancer. The collateral sensitivity phenomenon is suggested as a potential alternative therapy for coring multidrug resistance in cancer. To achieve better effects and reduce toxicity, a polypharmacology strategy was applied. Arctigenin has been reported as a signal transducer and activator of transcription 3 (STAT3) inhibitor as an anticancer drug with low toxicity. However, the effective dosage of arctigenin was too high for re-sensitization in MDR cell lines. Therefore, we have designed and synthesized arctigenin derivatives and have evaluated their chemoreversal effects in KBvin and KB cells. The results conveyed that compounds 9, 10, and 12 displayed significant collateral sensitivity effects on MDR cancer cells, and the corresponding calculated RF values were 32, 174, and 133, respectively. In addition, compounds 9, 10, and 12 were identified to influence the activation of STAT3 and the function of P-glycoprotein in KBvin cells. Combining the active compounds (9, 10, and 12) with paclitaxel significantly inhibits MDR tumor growth in a zebrafish xenograft tumor model without toxicity. Thus, this study provided novel effective arctigenin derivatives and is considered a potential co-treatment with paclitaxel for treating MDR tumors.

Method Development for Determination of Doripenem in Human Plasma via Capillary Electrophoresis Coupled with Field-Enhanced Sample Stacking and Sweeping.

In this study, we established a novel capillary electrophoresis method for monitoring the concentration of doripenem in human plasma. As a time-dependent antibiotic, doripenem maximizes its antibacterial effects and minimizes the potential for antibiotic resistance through careful therapeutic drug monitoring. Two online preconcentration techniques, field-enhanced sample stacking (FESS) and sweeping, were coupled to enhance the detection sensitivity. Briefly, an uncoated fused silica capillary (40 cm × 50 µm i.d) was rinsed with a high conductivity buffer (HCB) composed of 150 mM phosphate buffer (NaH2PO4, pH 2.5) and 20% methanol. A large sample plug prepared in a low-conductivity phosphate buffer (50 mM NaH2PO4, pH 2.5) was then hydrodynamically injected (5 psi, 80 s) into the capillary. Under an applied voltage of -30 kV, the analyte was accumulated at the FESS boundary and swept by the negatively charged micelles toward the UV detector. Plasma samples were pretreated by solid-phase extraction (SPE) to eliminate endogenous interferences. The validation results demonstrated a high coefficient of determination (r2 > 0.9995) for the regression curve with impressive precision and accuracy: relative standard deviation (RSD) <5.86% and relative error <4.63%. The limit of detection (LOD, S/N = 3) for doripenem was determined to be 0.4 µg/mL. Compared to the conventional micellar electrokinetic chromatography method, our developed method achieved a sensitivity enhancement of up to 488-fold for doripenem. Furthermore, the newly developed method successfully quantified doripenem concentrations in plasma samples obtained from patients accepting doripenem regimens, proving its application potential in the clinical realm.

Pinostrobin and Tectochrysin Conquer Multidrug-Resistant Cancer Cells via Inhibiting P-Glycoprotein ATPase.

Enhanced drug efflux through ATP-binding cassette transporters, particularly P-glycoprotein (P-gp), is a key mechanism underlying multidrug resistance (MDR). In the present study, we investigated the inhibitory effects of pinostrobin and tectochrysin on P-gp in MDR cancer cells and the underlying mechanisms. Fluorescence substrate efflux assays, multidrug resistance 1 (MDR1) shift assays, P-gp ATPase activity assays, Western blotting, and docking simulation were performed. The potential of the test compounds for MDR reversal and the associated molecular mechanisms were investigated through cell viability assay, cell cycle analysis, apoptosis assay, and further determining the combination index. Results demonstrated that pinostrobin and tectochrysin were not the substrates of P-gp, nor did they affect the expression of this transporter. Both compounds noncompetitively inhibited the efflux of rhodamine 123 and doxorubicin through P-gp. Furthermore, they resensitized MDR cancer cells to chemotherapeutic drugs, such as vincristine, paclitaxel, and docetaxel; thus, they exhibited strong MDR reversal effects. Our findings indicate that pinostrobin and tectochrysin are effective P-gp inhibitors and promising candidates for resensitizing MDR cancer cells.

Comparative efficacy and safety of non-polymyxin antibiotics against nosocomial pneumonia, complicated intra-abdominal infection, or complicated urinary tract infection: A network meta-analysis of randomised clinical trials.

OBJECTIVES: The increasing epidemic of infections caused by drug-resistant Gram-negative bacteria has led to the development of several antibiotic therapies. Owing to the scarcity of head-to-head comparisons of current and emerging antibiotics, the present network meta-analysis aimed to compare the efficacy and safety of antibiotics in patients with nosocomial pneumonia, complicated intra-abdominal infection, or complicated urinary tract infection. METHODS: Two independent researchers systematically searched databases up to August 2022 and included 26 randomised controlled trials that fulfilled the inclusion criteria. The protocol was registered in the Prospective Register of Systematic Reviews, PROSPERO (CRD42021237798). The frequentist random effects model (R version 3.5.1, netmeta package) was utilized. The DerSimonian-Laird random effects model was used to estimate heterogeneity. The calculated P-score was applied to rank the interventions. Additionally, inconsistencies, publication bias, and subgroup effects were assessed in the present study to avoid bias. RESULTS: There was no significant difference among included antibiotics in terms of clinical response and mortality, probably because most antibiotic trials were designed to be non-inferior. In terms of P-score ranking, carbapenems may be the recommended choice considering both adverse events and clinical responses. On the other hand, for carbapenem-sparing options, ceftolozane-tazobactam was the preferred antibiotic for nosocomial pneumonia; eravacycline, for complicated intra-abdominal infection; and cefiderocol, for complicated urinary tract infection. CONCLUSION: Carbapenems may be preferable options in terms of safety and efficacy for the treatment of Gram-negative bacterial complicated infections. However, to preserve the effectiveness of carbapenems, it is important to consider carbapenem-sparing regimens.

Pharmacological Interventions for Excessive Daytime Sleepiness in Adults with Narcolepsy: A Systematic Review and Network Meta-Analysis.

Narcolepsy is a neurological disease characterized by a core symptom of excessive daytime sleepiness (EDS). Although effective pharmacological interventions for narcolepsy have been developed, a lack of comparative evidence supporting the relative efficacy among these medications leads to clinical treatment challenge. Therefore, we performed a network meta-analysis to overcome this lack of head-to-head comparisons. Databases were searched systematically for randomized controlled trials that compared pharmacological interventions for narcolepsy. The primary outcomes were changes in the Epworth Sleepiness Scale (ESS) and the Maintenance of Wakefulness Test (MWT). A random-effects frequentist network meta-analysis was conducted. A total of 19 RCTs involving 2504 patients were included. Solriamfetol achieved the highest ranking based on the P-scores, and was superior to pitolisant (MD -2.88, 95% CI -4.89--0.88) and sodium oxybate (MD -2.56, 95% CI -4.62--0.51) for ESS change. Consistently, solriamfetol achieved the highest ranking according to MWT change, and was superior to pitolisant (SMD 0.45, 95% CI 0.02-0.88) and modafinil (SMD 0.42, 95% CI 0.05-0.79). Although solriamfetol demonstrated superior efficacy in EDS improvement, evidence from the clustered ranking plot supported that efficacy-safety profiles of pitolisant, sodium oxybate, and modafinil are more balanced than solriamfetol. Therefore, the choice of medication for EDS in narcolepsy should be made on an individual basis.

Reversal of multidrug resistance by Fissistigma latifolium-derived chalconoid 2-hydroxy-4,5,6-trimethoxydihydrochalcone in cancer cell lines overexpressing human P-glycoprotein.

Cancer treatment is an evolving field with various challenges to clinical practice. One unresolved problem in this field is multidrug resistance (MDR) mediated by ABC efflux transporters, particularly P-glycoprotein (P-gp). In this study, by prescreening compounds, we identified the potential of a dihydrochalcone compound, 2-hydroxy-4,5,6-trimethoxydihydrochalcone, for P-gp inhibition. Therefore, we investigated its ability to inhibit P-gp and reverse P-gp-mediated MDR, as well as the underlying mechanisms. The P-gp-inhibitory effects of 2-hydroxy-4,5,6-trimethoxydihydrochalcone were investigated as follows. A P-gp efflux assay and an ATPase assay were used to understand the modulatory mechanisms in the drug-binding and ATP-binding areas, respectively. Prominent reversal effects observed in MDR cancer cell lines; thus, reversal, cytotoxicity, cell cycle, apoptosis, and reactive oxygen species assays were conducted to investigate the underlying mechanism. The results indicated that 2-hydroxy-4,5,6-trimethoxydihydrochalcone functionally inhibited P-gp in a noncompetitive manner, and this inhibition was unrelated to expression. In addition, 2-hydroxy-4,5,6-trimethoxydihydrochalcone served as an ATPase stimulator but not as a P-gp substrate. Moreover, a low binding energy of - 6.85 kcal/mol and one hydrogen bond were obtained, indicating that 2-hydroxy-4,5,6-trimethoxydihydrochalcone has a high affinity for P-gp. P-gp-mediated MDR was reversed by 31.6 µM 2-hydroxy-4,5,6-trimethoxydihydrochalcone in combination with paclitaxel, with a reversal fold value of 379.42. In conclusion, this study provides evidence of the ability of 2-hydroxy-4,5,6-trimethoxydihydrochalcone to inhibit P-gp and reverse MDR.

Novel application of rhein and its prodrug diacerein for reversing cancer-related multidrug resistance through the dual inhibition of P-glycoprotein efflux and STAT3-mediated P-glycoprotein expression.

Multidrug resistance (MDR) is a multifactorial issue in cancer treatment. Drug efflux transporters, particularly P-glycoprotein (P-gp), are major contributors to such resistance. In the present study, we evaluated the P-gp-inhibiting and MDR-reversing effects of two compounds, namely rhein, an anthraquinone, and diacerein, the acetylated prodrug of rhein. ABCB1/Flp-In-293 was used as a model for investigating the related molecular mechanisms, and the multi-drug-resistant cancer cell line KB/VIN was used as a platform for evaluating the reversal of MDR0. The results indicated that at a concentration of 2.5 µM, both diacerein and rhein significantly inhibited P-gp efflux function. They also downregulated P-gp expression by interacting with the signal transducer and activator of transcription 3. Further investigation of the inhibitory mechanism of these compounds revealed that both stimulated P-gp ATPase activity dose dependently and engaged in the noncompetitive inhibition of rhodamine 123 efflux. Furthermore, rhein was revealed to be a potent reverser of MDR in cancer, and the combination of 30 µM rhein and 1000 nM vincristine exerted a strong synergistic effect, achieving a high combination index (CI) of 0.092. Diacerein demonstrated potential applications as a selective cytotoxic agent against multi-drug-resistant cancer cells at a concentration of > 18.92 µM and as a mild MDR reverser at doses of < 10 µM. In conclusion, diacerein and rhein are potential candidates for P-gp inhibition and MDR reversal in cancer cells.

Design, Synthesis and Evaluation of Novel Derivatives of Curcuminoids with Cytotoxicity.

Curcumin and curcuminoids have been discussed frequently due to their promising functional groups (such as scaffolds of α,ß-unsaturated ß-diketone, α,ß-unsaturated ketone and ß'-hydroxy-α,ß-unsaturated ketone connected with aromatic rings on both sides) that play an important role in various bioactivities, including antioxidant, anti-inflammatory, anti-proliferation and anticancer activity. A series of novel curcuminoid derivatives (a total of 55 new compounds) and three reference compounds were synthesized with good yields using three-step organic synthesis. The anti-proliferative activities of curcumin derivatives were examined for six human cancer cell lines: HeLaS3, KBvin, MCF-7, HepG2, NCI-H460 and NCI-H460/MX20. Compared to the IC50 values of all the synthesized derivatives, most α,ß-unsaturated ketones displayed potent anti-proliferative effects against all six human cancer cell lines, whereas ß'-hydroxy-α,ß-unsaturated ketones and α,ß-unsaturated ß-diketones presented moderate anti-proliferative effects. Two potent curcuminoid derivatives were found among all the novel derivatives and reference compounds: (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a). These were selected for further analysis after the evaluation of their anti-proliferative effects against all human cancer cell lines. The results of apoptosis assays revealed that the number of dead cells was increased in early apoptosis and late apoptosis, while cell proliferation was also decreased after applying various concentrations of (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) to MCF-7 and HpeG2 cancer cells. Analysis of the gene expression arrays showed that three genes (GADD45B, SESN2 and BBC3) were correlated with the p53 pathway. From the quantitative PCR analysis, it was seen that (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) effectively induced the up-regulated expression of GADD45B, leading to the suppression of MCF-7 cancer cell formation and cell death. Molecular docking analysis was used to predict and sketch the interactions of the GADD45B-α,ß-unsaturated ketone complex for help in drug design.

Cinnamophilin overcomes cancer multi-drug resistance via allosterically modulating human P-glycoprotein on both drug binding sites and ATPase binding sites.

Cancer multi-drug resistance (MDR) caused by P-glycoprotein (P-gp) efflux is a critical unresolved clinical concern. The present study analyzed the effect of cinnamophilin on P-gp inhibition and MDR reversion. The effect of cinnamophilin on P-gp was investigated through drug efflux assay, ATPase assay, MDR1 shift assay, and molecular docking. The cancer MDR-reversing ability and mechanisms were analyzed through cytotoxicity and combination index (CI), cell cycle, and apoptosis experiments. P-gp efflux function was significantly inhibited by cinnamophilin without influencing the drug's expression or conformation. Cinnamophilin uncompetitively inhibited the efflux of doxorubicin and rhodamine 123 and exhibited a distinct binding behavior compared with verapamil, the P-gp standard inhibitor. The half maximal inhibitory concentration of cinnamophilin for doxorubicin and rhodamine 123 efflux was 12.47 and 11.59 µM, respectively. In regard to P-gp energy consumption, verapamil-stimulated ATPase activity was further enhanced by cinnamophilin at concentrations of 0.1, 1, 10, and 20 µM. In terms of MDR reversion, cinnamophilin demonstrated synergistic cytotoxic effects when combined with docetaxel, vincristine, or paclitaxel. The CI was < 0.7 in all experimental combination treatments. The present study showed that cinnamophilin possesses P-gp-modulating effects and cancer MDR resensitizing ability.

Comprehensive Comparison of the Effect of Inotropes on Cardiorenal Syndrome in Patients with Advanced Heart Failure: A Network Meta-Analysis of Randomized Controlled Trials.

Prevention of cardiorenal syndrome through treatment with inotropic agents remains challenging. This network meta-analysis evaluated the safety and renoprotective effects of inotropes on patients with advanced heart failure (HF) using a frequentist random-effects model. A systematic database search was performed until 31 January 2021, and a total of 37 trials were included. Inconsistency, publication bias, and subgroup analyses were conducted. The levosimendan group exhibited significantly decreased mortality compared with the control (odds ratio (OR): 0.62; 95% confidence interval (CI): 0.46-0.84), milrinone (OR: 0.50; 95% CI: 0.30-0.84), and dobutamine (OR: 0.75; 95% CI: 0.57-0.97) groups. In terms of renal protection, levosimendan (standardized mean difference (SMD): 1.67; 95% CI: 1.17-2.18) and dobutamine (SMD: 1.49; 95% CI: 0.87-2.12) more favorably improved the glomerular filtration rate (GFR) than the control treatment did, but they did not significantly reduce the incidence of acute kidney injury. Furthermore, levosimendan had the highest P-score, indicating that it most effectively reduced mortality and improved renal function (e.g., GFR and serum creatinine level), even in patients with renal insufficiency. In conclusion, levosimendan is a safe alternative for protecting renal function on cardiorenal syndrome in patients with advanced HF.

Chemoreversal Agents from Taiwanofungus Genus and Their More Potent Methyl Derivatives Targeting Signal Transducer and Activator of Transcription 3 (STAT3) Phosphorylation.

Multidrug resistance (MDR), for which the mechanisms are not yet fully clear, is one of the major obstacles to cancer treatment. In recent years, signal transducer and activator of transcription 3 (STAT3) were found to be one of the important MDR mechanism pathways. Based on the previous research, zhankuic acid A, B, and C were found to have collateral sensitivity effects on MDR cancer cells, and MDR inhibitory activity of zhankuic acid methyl ester was found to be better than that of its acid. Therefore, we executed a systematic examination of the structure-activity relationship of zhankuic acid methyl ester derivatives to collateral sensitivity in MDR cancer cells. The results showed that compound 12 is the best in terms of chemoreversal activity, where the reversal fold was 692, and the IC50 value of paclitaxel combined with 10 µM compound 12 treatment was 1.69 nM in MDR KBvin cells. Among all the derivatives, methyl ester compounds were found to be better than their acids, and a detailed discussion of the structure-activity relationships of all of the derivatives is provided in this work. In addition, compounds 8, 12, and 26 were shown to influence the activation of STAT3 in KBvin cells, accounting for part of their chemoreversal effects. Our results may provide a new combined therapy with paclitaxel to treat multidrug-resistant cancers and provide a new therapy option for patients.

Bioactive naphthoquinones and triterpenoids from the fruiting bodies of Taiwanofungus salmoneus.

Drug resistance of cancer cells stands for the major problem of the treatment failure for chemotherapy or target therapy. Overexpression of efflux pumps leading to multidrug resistance (MDR) is still an important issue needed to be solved. In the present study, Taiwanofungus salmoneus was selected as the topic and eleven undescribed constituents including four naphthoquinones salmonones A-D (1-4) and seven triterpenoids salmoneatins A-G (5-11), along with one chromanone (12) and two benzenoids (13 and 14) reported from the natural sources for the first time, as well as twenty-one known compounds were characterized. The structures of undescribed compounds were established by the spectroscopic and spectrometric analyses. In addition, the plausible biosynthetic mechanism of purified naphthoquinones was proposed and these compounds may be the excellent chemotaxonomic markers. Moreover, the isolates were evaluated for their P-gp inhibitory effects and the results showed that most of the examined compounds were effective. Among the tested compounds, 5, 10, 2,3-dimethoxy-5-(2',5'-dimethoxy-3',4'-methylenedioxyphenyl)-7-methyl-[1,4]naphthoquinone, zhankuic acid A methyl ester, and camphoratin F can reverse the resistance of paclitaxel or vincristine with the reversal folds in the range of 51093.3 and 259.5. These experimental data would initiate the possible development of Taiwanofungus salmoneus for the cancer therapy in the future.

Comprehensive Comparisons among Inotropic Agents on Mortality and Risk of Renal Dysfunction in Patients Who Underwent Cardiac Surgery: A Network Meta-Analysis of Randomized Controlled Trials.

Several kinds of inotropes have been used in critically ill patients to improve hemodynamics and renal dysfunction after cardiac surgery; however, the treatment strategies for reducing mortality and increasing renal protection in patients who underwent cardiac surgery remain controversial. Therefore, we performed a comprehensive network meta-analysis to overcome the lack of head-to-head comparisons. A systematic database was searched up to 31 December 2020, for randomized controlled trials that compared different inotropes on mortality outcomes and renal protective effects after cardiac surgery. A total of 29 trials were included and a frequentist network meta-analysis was performed. Inconsistency analyses, publication bias, and subgroup analyses were also conducted. Compared with placebo, use of levosimendan significantly decreased the risks of mortality (odds ratio (OR): 0.74; 95% confidence interval (CI): 0.56-0.97) and risk of acute renal injury (OR: 0.61; 95% CI: 0.45-0.82), especially in low systolic function patients. Use of levosimendan also ranked the best treatment based on the P-score (90.1%), followed by placebo (64.5%), milrinone (49.6%), dopamine (49.5%), dobutamine (29.1%), and fenoldopam (17.0%). Taking all the available data into consideration, levosimendan was a safe renal-protective choice for the treatment of patients undergoing cardiac surgery, especially for those with low systolic function.

A novel flavonoid from Fissistigma cupreonitens, 5­hydroxy­7,8­dimethoxyflavanone, competitively inhibited the efflux function of human P-glycoprotein and reversed cancer multi-drug resistance.

BACKGROUND: P-glycoprotein (P-gp) over-expression plays a vital role in not only systemic drug bioavailability but also cancer multi-drug resistance (MDR). Develop functional inhibitors of P-gp can conquer both problems. PURPOSE AND STUDY DESIGN: The aim of the present study was to research the P-gp modulating effects and MDR reversing ability of a novel flavonoid from Fissistigma cupreonitens, the underlying inhibitory mechanisms were further elucidated as well. METHODS: Calcein-AM, rhodamine 123, and doxorubicin were fluorescent substrates for the evaluation of P-gp inhibitory function and detailed drug binding modes. Docking simulation was performed to reveal the in silico molecular bonding. ATPase assay and MDR1 shift assay were adopted to reveal the ATP consumption and conformational change of P-gp. The MDR reversing effects were demonstrated through cytotoxicity, cell cycle, and apoptosis analyses. RESULTS: 5­hydroxy­7,8­dimethoxyflavanone inhibited the efflux of rhodamine 123 and doxorubicin in a competitive manner, and increased the intracellular fluorescence of calcein at a concentration as low as 2.5 µg/ml. 5­hydroxy­7,8­dimethoxyflavanone slightly changed P-gp's conformation and only stimulated ATPase at very high concentration (100 µg/ml). The docking results showed that 5­hydroxy­7,8­dimethoxyflavanone and verapamil exhibited similar binding affinity to P-gp. The MDR reversing effects were prominent in the vincristine group, the reversal folds were 23.01 and 13.03 when combined with 10 µg/ml 5­hydroxy­7,8­dimethoxyflavanone in the P-gp over-expressing cell line (ABCB1/Flp-In™-293) and MDR cancer cell line (KB/VIN), respectively. CONCLUSION: The present study demonstrated that 5­hydroxy­7,8­dimethoxyflavanone was a novel effective flavonoid in the P-gp efflux inhibition and in vitro cancer MDR reversion.

A Matrix Metalloproteinase-2-Based Nomogram to Assess the Risk of Encapsulating Peritoneal Sclerosis in Peritoneal Dialysis Patients.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis (PD). So far, there is no biomarker-based prediction tool available for EPS. Matrix metalloproteinase-2 (MMP-2) is a protein involved in the breakdown of the extracellular matrix, and the effluent MMP-2 can be a potential biomarker of EPS. This study is aimed at developing a nomogram for EPS based on effluent MMP-2 levels. Patients and Methods. We enrolled 18 EPS patients and 90 gender-matched PD patients without EPS in this cross-sectional case-controlled study. The effluent MMP-2 levels and possible risk factors for EPS were analyzed using multivariable logistic regression, and a nomogram was developed. The nomogram was validated using 200 bootstrap resamples to reduce overfit bias. RESULTS: The effluent MMP-2 levels in EPS patients were significantly higher than those in normal PD patients (p < 0.001, Manny-Whitney U test). Effluent MMP-2 levels and PD duration were independently associated with EPS risks (p < 0.001 and p = 0.001) in multivariate logistic regression. A nomogram based on MMP-2 levels and PD duration was proposed. The AUC of MMP-2 was 0.824, and the AUC of the nomogram was 0.907 (p = 0.05). CONCLUSION: A nomogram based on effluent MMP-2 levels and PD duration may predict EPS with high accuracy.

Identification of GSN and LAMC2 as Key Prognostic Genes of Bladder Cancer by Integrated Bioinformatics Analysis.

Bladder cancer is a common malignancy with mechanisms of pathogenesis and progression. This study aimed to identify the prognostic hub genes, which are the central modulators to regulate the progression and proliferation in the specific subtype of bladder cancer. The identification of the candidate hub gene was performed by weighted gene co-expression network analysis to construct a free-scale gene co-expression network. The gene expression profile of GSE97768 from the Gene Expression Omnibus database was used. The association between prognosis and hub gene was evaluated by The Cancer Genome Atlas database. Four gene-expression modules were significantly related to bladder cancer disease: the red module (human adenocarcinoma lymph node metastasis), the darkturquioise module (grade 2 carcinoma), the lightgreen module (grade 3 carcinoma), and the royalblue module (transitional cell carcinoma lymphatic metastasis). Based on betweenness centrality and survival analysis, we identified laminin subunit gamma-2 (LAMC2) in the grade 2 carcinoma, gelsolin (GSN) in the grade 3 carcinoma, and homeodomain-interacting protein kinase 2 (HIPK2) in the transitional cell carcinoma lymphatic metastasis. Subsequently, the protein levels of LAMC2 and GSN were respectively down-regulated and up-regulated in tumor tissue with the Human Protein Atlas (HPA) database. Our results suggested that LAMC2 and GSN are the central modulators to transfer information in the specific subtype of the disease.

Synthesis and biological evaluation of thiophenylbenzofuran derivatives as potential P-glycoprotein inhibitors.

P-Glycoprotein (P-gp) overexpression is a major mechanism by which cancer cells acquire the multidrug resistance (MDR) phenotype, and is associated with poor clinical outcome in patients. In an effort to develop MDR-reversal agents, we synthesized and evaluated a series of thiophenylbenzofuran derivatives (4-31) as P-gp inhibitors, among which compounds 4, 10, and 14 represented the optimal agent in reversing the MDR phenotype. These P-gp inhibitors were dramatically effective than verapamil in sensitizing the human ABCB1-overexpressing ABCB1/Flp-In™-293 cells and MDR KBvin cells to a series of chemotherapeutic agents, including vincristine and paclitaxel, as manifested by multi-fold decreases in the respective IC50 values to therapeutically attainable levels.

Wilforine resensitizes multidrug resistant cancer cells via competitive inhibition of P-glycoprotein.

BACKGROUND AND PURPOSE: Multidrug resistance (MDR) remains the main obstacle in cancer treatment and overexpression of P-glycoprotein (P-gp) is one of the most common causes of chemoresistance. The development of novel P-gp inhibitors from natural products is a prospective strategy to combat MDR cancers. Among the natural sesquiterpene compounds, sesquiterpene pyridine alkaloids exhibit various biological properties. Therefore, in the present study, we evaluated the modulatory effects of wilforine on P-gp expression and function. The molecular mechanisms and kinetic models of wilforine-mediated P-gp inhibition were further investigated. METHODS: The human P-gp stable expression cells (ABCB1/Flp-InTM-293) and human cervical cancer cells (sensitive: HeLaS3; MDR: KBvin) were used. The cell viability was assessed by SRB assay. The inhibitory effect of wilforine on P-gp efflux and the underlying mechanism were evaluated by assays for calcein-AM uptake, rhodamine123 and doxorubicin efflux, ATPase activity, real-time quantitative RT-PCR, apoptosis, and cell cycle analysis. Molecular docking was performed by the docking software CDOCKER with BIOVIA Discovery Studio 4.5 (D.S. 4.5). RESULTS: We found that wilforine significantly inhibited the efflux activity of P-gp in a concentration-dependent manner. Further kinetic analysis demonstrated that wilforine significantly inhibited P-gp efflux function by competitive inhibition and stimulated the basal P-gp ATPase activity. In addition, wilforine re-sensitized MDR cancer cells to chemotherapeutic drugs. The docking model indicated that wilforine was bound to residues of P-gp such as LEU884, LYS887, THR176 and ASN172. CONCLUSION: These results suggest a novel future therapeutic strategy for MDR cancer using wilforine as an adjuvant treatment with chemotherapy.