-
Cancer Cell International May 2013The multidrug resistance (MDR) 1 gene encodes a 170-kDa membrane transporter called P-glycoprotein, which plays an important role in protecting cells against lipophilic...
BACKGROUND
The multidrug resistance (MDR) 1 gene encodes a 170-kDa membrane transporter called P-glycoprotein, which plays an important role in protecting cells against lipophilic xenobiotics by the way of an ATP-dependent cellular efflux mechanism. Three polymorphisms of MDR1, 3435C > T located in exon 26, 1236C > T in exon 12 and 2677G > T/A in exon 21 were the most extensively studied and were identified functionally important and ethnically diverse mapping to the gene region. Considering the potential influence of altering MDR1 activity, it is plausible that MDR1 polymorphisms might play a role in the development of cancer. Although the effects of MDR1 polymorphisms on susceptibility to human cancer have been investigated in many studies, the results still remain conflicting.
METHODS
To resolve these conflicts, we performed a quantitative synthesis of the association between these three polymorphisms and cancer risk, including 52 studies (15789 cases and 20274 controls) for 3435C > T polymorphism, 10 studies (2101 cases and 2842 controls) for 1236C > T polymorphism and 18 studies (3585 cases and 4351 controls) for 2677G > T/A polymorphism.
RESULTS
The stratified analyses for 3435C > T polymorphism, individuals with T-allele in 3435C > T had significantly higher ALL risks (TT versus CC: OR =1.286, 95% CI =1.123-1.474); significantly elevated risks were observed among Caucasian populations (TT versus CC: OR =1.276, 95% CI =1.112-1.464). When restricting the analysis to the source of controls, we found that HB (hospital-based) genetic models had higher risks (TT versus CC: OR =1.307, 95% CI =1.046-1.632), as well as in PB (population-based) genetic models (TT versus CC: OR =1.294, 95% CI =1.079-1.55).The T/A-allele frequency of 2677G > T/A polymorphism was associated with higher risk of cancer (TT + TA + AA vs. GG: OR =1.348, 95% CI =1.031-1.762), significantly elevated risks were observed among Asian populations (TT + TA + AA vs. GG: OR =1.642, 95% CI =1.340-2.012), and elevated risks could be associated with PB models (TT + TA + AA vs. GG: OR =1.641, 95% CI =1.018-2.646).
CONCLUSIONS
Our meta-analysis suggested that 3435C > T polymorphism and 2677G > T/A polymorphism were associated with cancer risk when all studies were pooled together, while 1236C > T polymorphism not.
PubMed: 23687985
DOI: 10.1186/1475-2867-13-46 -
Pharmaceutical Research May 2021The involvement of the intestinally expressed xenobiotic transporters P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) have been implicated in...
PURPOSE
The involvement of the intestinally expressed xenobiotic transporters P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) have been implicated in rivaroxaban disposition based on in vitro studies, similar to what had previously been proposed for apixaban. We recently showed that these efflux transporters were not clinically relevant for apixaban disposition and examine here their relevance for this second Factor Xa inhibitor.
METHODS
Using recently published methodologies to discern metabolic- from transporter- mediated drug interactions, a critical evaluation was undertaken of 9 rivaroxaban studies reporting 12 DDIs, one study of food effects and one study of hepatic function.
RESULTS
Rationale examination of these clinical studies using basic pharmacokinetic theory finds little support for the clinical significance of intestinal efflux transporters in rivaroxaban disposition. Drug-drug interactions are most likely adequately predicted based on the level of CYP 3A metabolism.
CONCLUSION
These analyses indicate that inhibition of efflux transporters appears to have negligible, clinically insignificant effects on the rivaroxaban absorption process, which is consistent with the concern that predictions based on in vitro measures may not translate to a clinically relevant interaction in vivo. We emphasize the need to evaluate gastric emptying, dissolution and other processes related to absorption when using MAT changes to indicate efflux transporter inhibition.
Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily G, Member 2; Administration, Oral; Drug Interactions; Drug Liberation; Factor Xa Inhibitors; Gastric Emptying; Gastrointestinal Absorption; Humans; Intestinal Mucosa; Neoplasm Proteins; Pyrazoles; Pyridones; Rivaroxaban; Tissue Distribution
PubMed: 33847849
DOI: 10.1007/s11095-021-03039-3 -
Current Cancer Drug Targets 2020Breast cancer is the most probable cancer among women. However, the available treatment is based on targeting different stages of breast cancer viz., radiation therapy,...
PURPOSE
Breast cancer is the most probable cancer among women. However, the available treatment is based on targeting different stages of breast cancer viz., radiation therapy, hormonal therapy, chemotherapy, and surgical interventions, which have some limitations. The available chemotherapeutics are associated with problems like low solubility, low permeability, high first-pass metabolism, and P-glycoprotein efflux. Hence, the aforementioned restrictions lead to ineffective treatment. Multiple chemotherapeutics can also cause resistance in tumors. So, the purpose is to develop an effective therapeutic regimen for the treatment of breast cancer by applying a nanomedicinal approach.
METHODS
This review has been conducted on a systematic search strategy, based on relevant literature available on Pub Med, MedlinePlus, Google Scholar, and Sciencedirect up to November 2019 using keywords present in abstract and title of the review. As per our inclusion and exclusion criteria, 226 articles were screened. Among 226, a total of 40 articles were selected for this review.
RESULTS
The significant findings with the currently available treatment is that the drug, besides its distribution to the target-specific site, also distributes to healthy cells, which results in severe side effects. Moreover, the drug is less bioavailable at the site of action; therefore, to overcome this, a high dose is required, which again causes side effects and lower the benefits. Nanomedicinal approaches give an alternative approach to avoid the associated problems of available chemotherapeutics treatment of breast cancer.
CONCLUSION
The nanomedicinal strategies are useful over the conventional treatment of breast cancer and deliver a target-specific drug-using different novel drug delivery approaches.
Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Drug Delivery Systems; Female; Humans; Nanostructures; Theranostic Nanomedicine
PubMed: 32228423
DOI: 10.2174/1568009620666200331124113 -
Journal of Interventional Cardiac... Jan 2019Amiodarone is a potent inhibitor of the CYP450:3A4 and inhibitor of the P-glycoprotein, both of which metabolize new oral anticoagulants (NOACs). Patients who are on... (Comparative Study)
Comparative Study
PURPOSE
Amiodarone is a potent inhibitor of the CYP450:3A4 and inhibitor of the P-glycoprotein, both of which metabolize new oral anticoagulants (NOACs). Patients who are on NOACs and are concomitantly treated with amiodarone may have a higher risk of major bleeding according to recent retrospective trials. Whether this increased risk outweighs the benefits of NOACs compared to warfarin is unknown. We aimed to compare clinical outcomes between NOACs and warfarin in patients with atrial fibrillation (AF) being treated with amiodarone.
METHODS
We performed a systematic review of MEDLINE, Cochrane, and Embase for randomized controlled trials that compared NOACs to warfarin for prophylaxis of ischemic stroke/thromboembolic events (TEs) in patients with AF and reported outcomes on TE, major bleeding, and intracranial bleeding (ICB). Risk ratio (RR) and 95% confidence intervals were measured using the Mantel-Haenszel method. Fixed effects model was used, and if heterogeneity (I2) was > 25%, effects were analyzed using a random model.
RESULTS
A total of four studies comparing NOACs to warfarin were included in the analysis. The total number of patients on amiodarone was 6197. Mean follow up was 23 ± 5 months. No statistically significant difference for TE prevention (RR, 0.73; 95% CI 0.50-1.07), major bleeding (RR, 1.02; 95% CI 0.68-1.53), or ICB outcomes (RR, 0.58; 95% CI 0.22-1.51) between patients on NOACs + amiodarone when compared to patients on warfarin + amiodarone.
CONCLUSION
Among patients with AF taking amiodarone, there is no increased risk of stroke, major bleeding, or ICB with NOACs compared to warfarin.
Topics: Administration, Oral; Aged; Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Female; Humans; Male; Middle Aged; Prognosis; Randomized Controlled Trials as Topic; Risk Assessment; Severity of Illness Index; Stroke; Survival Rate; Thromboembolism; Treatment Outcome; Warfarin
PubMed: 30128801
DOI: 10.1007/s10840-018-0427-y -
BMC Complementary Medicine and Therapies Jun 2020African Potato (hypoxis hemerocallidea), is used for enhancing immune system in Southern Africa. It is among the plants of intense commercial and scientific interest;...
BACKGROUND
African Potato (hypoxis hemerocallidea), is used for enhancing immune system in Southern Africa. It is among the plants of intense commercial and scientific interest; hence, the aim of this study was to describe its chemistry and pharmacology.
METHODS
PubMed, Cochrane Controlled Trials Register (CENTRAL) and Google Scholar were searched independently for relevant literature. The last search occurred in October 2018. Other research material was obtained from Google. The following search terms were used, but not limited to: "African Potato", "hypoxis", "hemerocallidea", "rooperol." Articles that were explaining the chemistry and pharmacology of hypoxis hemerocallidea were included.
RESULTS
Thirty articles from PubMed, Cochrane and Google Scholar were eligible. Three webpages were included from Google. Results showed that the tuberous rootstock (corm) of African Potato is used traditionally to treat wasting diseases, testicular tumours, insanity, barrenness, impotency, bad dreams, intestinal parasites, urinary infection, cardiac disease and enhancing immunity. The plant contains hypoxoside, which is converted rapidly to a potent antioxidant, rooperol in the gut. The corm contains sterols, sterol glycosides, stanols, terpenoids, saponins, cardiac glycosides, tannins and reducing sugars. A dose of 15 mg/kg/day of hypoxoside is reportedly therapeutic. Preclinical studies of African Potato have shown immunomodulation, antioxidant, antinociceptive, hypoglycaemic, anti-inflammatory, anticonvulsant, antibacterial, uterolytic, antimotility, spasmolytic and anticholinergic effects. The common side effects of African Potato are nausea and vomiting, which subside over time. In vitro, African Potato demonstrated inhibitory effects on CYP1A2, 2C9, 2D6, 3A4, 3A5, CYP19-metabolism and induction of P-glycoprotein. In vivo, it did not alter the pharmacokinetics of efavirenz or lopinavir/ritonavir.
CONCLUSION
African Potato is mainly used as an immunostimulant. The exact mechanisms of action for all the pharmacological actions are unknown. More research is required to substantiate claims regarding beneficial effects. There are many research gaps that require investigation including pharmacokinetic interactions with conventional drugs, especially those used in HIV/AIDS.
Topics: Africa; Catechols; Humans; Hypoxis; Medicine, African Traditional; Plant Extracts; Plants, Medicinal
PubMed: 32527245
DOI: 10.1186/s12906-020-02956-x -
Oncogene Jan 2023Over the last 40 years osteosarcoma (OS) survival has stagnated with patients commonly resistant to neoadjuvant MAP chemotherapy involving high dose methotrexate,...
Over the last 40 years osteosarcoma (OS) survival has stagnated with patients commonly resistant to neoadjuvant MAP chemotherapy involving high dose methotrexate, adriamycin (doxorubicin) and platinum (cisplatin). Due to the rarity of OS, the generation of relevant cell models as tools for drug discovery is paramount to tackling this issue. Four literature databases were systematically searched using pre-determined search terms to identify MAP resistant OS cell lines and patients. Drug exposure strategies used to develop cell models of resistance and the impact of these on the differential expression of resistance associated genes, proteins and non-coding RNAs are reported. A comparison to clinical studies in relation to chemotherapy response, relapse and metastasis was then made. The search retrieved 1891 papers of which 52 were relevant. Commonly, cell lines were derived from Caucasian patients with epithelial or fibroblastic subtypes. The strategy for model development varied with most opting for continuous over pulsed chemotherapy exposure. A diverse resistance level was observed between models (2.2-338 fold) with 63% of models exceeding clinically reported resistance levels which may affect the expression of chemoresistance factors. In vitro p-glycoprotein overexpression is a key resistance mechanism; however, from the available literature to date this does not translate to innate resistance in patients. The selection of models with a lower fold resistance may better reflect the clinical situation. A comparison of standardised strategies in models and variants should be performed to determine their impact on resistance markers. Clinical studies are required to determine the impact of resistance markers identified in vitro in poor responders to MAP treatment, specifically with respect to innate and acquired resistance. A shift from seeking disputed and undruggable mechanisms to clinically relevant resistance mechanisms may identify key resistance markers that can be targeted for patient benefit after a 40-year wait.
Topics: Humans; Antineoplastic Combined Chemotherapy Protocols; Bone Neoplasms; Cisplatin; Clinical Relevance; Doxorubicin; Neoplasm Recurrence, Local; Osteosarcoma; Drug Resistance, Neoplasm
PubMed: 36434179
DOI: 10.1038/s41388-022-02529-x -
Journal of Drug Targeting Jul 2020Cellular assays are essential in pharmaceutical development of protein-loaded nanomedicine. Cell lines provide robust and efficient models to characterise cytotoxicity,...
Cellular assays are essential in pharmaceutical development of protein-loaded nanomedicine. Cell lines provide robust and efficient models to characterise cytotoxicity, cellular uptake, absorption mechanism, intracellular stability, exocytosis mechanism and therapeutic effects of nanomedicine. GI epithelial cells and goblet cells have been employed to examine protein-loaded nanoparticles . However, the existence of different research protocols hampers the comparison of formulations and obtained results. Although advanced novel microscopy and fluorescent detection techniques are available for facilitating the development of nano-sized formulation, optimised research designs and validated instrument operation procedure are crucial to increase the reliability and validity of research findings. In the current review article, we examined a number of cellular assays, including cellular culture, cytotoxicity assay, cellular uptake assay, transepithelial studies, permeability assays, glucose consumption assays, and exocytosis and endocytosis studies, that have been widely employed for the development of orally administered insulin-loaded nanoparticles. Meanwhile, the role of various technologies, such as CLSM, flow cytometry, ELISA, fluorescence microscopy, microplate reader, and transmission electron microscopy, on visualisation of nanoparticle cellular uptake was evaluated. The following four challenges, including limited nanoparticle diffusion across mucus barrier, unwanted apical exocytosis, P-glycoprotein efflux pumps, endosomal entrapment and lysosomal degradation on protein-loaded nanoparticles, should be addressed in future studies. During formulation optimisation, strategies that can overcome the above hinderance are warranted to maximise oral bioavailability, minimise waste in research funding and facilitate the translation of therapeutic protein-loaded nanomedicine into clinical settings.
Topics: Administration, Oral; Cell Line, Tumor; Humans; Nanoparticles; Proteins
PubMed: 32013626
DOI: 10.1080/1061186X.2020.1726356 -
Hamostaseologie Dec 2020Recombinant interleukin-2 (rIL-2) is indicated for metastatic renal cell carcinoma and melanoma. Over recent years low-dose rIL-2 has been studied for the treatment of...
Recombinant interleukin-2 (rIL-2) is indicated for metastatic renal cell carcinoma and melanoma. Over recent years low-dose rIL-2 has been studied for the treatment of autoimmune diseases and acute coronary syndrome because of its ability to expand and activate T regulatory (T) cells. However, several medical conditions potentially benefiting from rIL-2 administrations are characterized by an intrinsic prothrombotic risk, thus requiring concurrent anticoagulation. In our systematic review of the literature, we investigated the potential for drug interactions between oral anticoagulants and rIL-2 by assessing the influence of rIL-2 administration on transporters and cytochromes determining the pharmacokinetics of (direct) oral anticoagulants. We extracted data from 12 studies, consisting of 11 animal studies and one study in humans. Eight studies investigated the pharmacokinetics of P-glycoprotein (P-gp) substrates and reported that the intraperitoneal rIL-2 administration may inhibit intestinal P-gp. Four studies on hepatic cytochrome P450 yielded conflicting results. The only human study included in this systematic review concluded that rIL-2 suppresses the hepatic cytochrome P450, but only if given at higher doses. Based on the results from animal studies, the co-administration of rIL-2 and dabigatran etexilate, a substrate of intestinal P-gp, may lead to higher dabigatran plasma concentrations and bioavailability. Human studies should confirm whether this potential interaction is clinically relevant.
Topics: Animals; Drug Interactions; Factor Xa Inhibitors; Humans; In Vivo Dosimetry; Interleukin-2
PubMed: 32325520
DOI: 10.1055/a-1120-4064 -
Pharmacogenetics and Genomics Aug 2012In the present study, we performed a systematic review and meta-analysis on published data to examine the impact of CYP3A5 6986A>G and ABCB1 3435C>T polymorphisms on... (Meta-Analysis)
Meta-Analysis
The effect of CYP3A5 6986A>G and ABCB1 3435C>T on tacrolimus dose-adjusted trough levels and acute rejection rates in renal transplant patients: a systematic review and meta-analysis.
In the present study, we performed a systematic review and meta-analysis on published data to examine the impact of CYP3A5 6986A>G and ABCB1 3435C>T polymorphisms on tacrolimus dose-adjusted trough levels (C0/D) and acute rejection rates in adult renal transplant patients. Despite the presence of significant heterogeneity in all comparisons, random-effects model showed significantly higher tacrolimus C0/D in CYP3A53/3 compared with CYP3A51 allele carriers, either in the overall analysis and when stratifying for ethnicity or time of post-transplantation (≤1, 3-6, 12-24 months). In contrast, no consistent evidence of an effect of the ABCB1 3435C>T variant was detected on tacrolimus C0/D, except for a modest effect limited to the first month after renal transplantation. In addition, from the current evidence available, CYP3A5 6986A>G and ABCB1 3435C>T polymorphisms seem to have little or no effect on the acute rejection rates in renal transplant patients under immunosuppressive therapy with tacrolimus.
Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Alleles; Cytochrome P-450 CYP3A; Genetic Association Studies; Genotype; Graft Rejection; Humans; Immunosuppressive Agents; Kidney Transplantation; Survival Rate; Tacrolimus
PubMed: 22786571
DOI: 10.1097/FPC.0b013e3283557c74 -
The Pharmacogenomics Journal Apr 2015The ABCB1 gene encodes for P-glycoprotein (P-gp), an efflux pump for a variety of xenobiotics. The role of ABCB1 polymorphisms in acute myeloid leukemia (AML) outcomes... (Meta-Analysis)
Meta-Analysis
The ABCB1 gene encodes for P-glycoprotein (P-gp), an efflux pump for a variety of xenobiotics. The role of ABCB1 polymorphisms in acute myeloid leukemia (AML) outcomes of standard chemotherapy (cytarabine plus anthracyclines) remains controversial. A systematic search was made of studies evaluating the association between ABCB1 polymorphisms 1236C>T, 2677G>T/A and 3435C>T and effectiveness variables. We found seven cohort studies (1241 patients) showing a significantly higher overall survival (OS) among carriers of the variant allele of 1236C>T at year 4 (odds ratio (OR): 1.47, 95% confidence interval (CI): 1.07-2.01), 2677G>T/A at years 4-5 (OR: 1.37, 95% CI: 1.01-1.86) and 3435C>T at years 3 (OR: 1.41, 95% CI: 1.03-1.94) and 4-5 (OR: 1.42, 95% CI: 1.05-1.91). In the subgroup analysis according to ethnicity, Caucasians carrying variant allele showed consistent results in OS. ABCB1 influence upon complete remission could not be demonstrated. Future studies based on larger populations and multiethnic groups should help clarify the effect of P-gp polymorphisms upon other outcomes.
Topics: ATP Binding Cassette Transporter, Subfamily B; Adolescent; Adult; Aged; Aged, 80 and over; Anthracyclines; Child; Child, Preschool; Cohort Studies; Cytarabine; Female; Humans; Infant; Leukemia, Myeloid, Acute; Male; Middle Aged; Observational Studies as Topic; Polymorphism, Genetic; Treatment Outcome; Young Adult
PubMed: 25558979
DOI: 10.1038/tpj.2014.80