Metabolism Of Anticancer Drugs Research Articles

COSMIC Database and Structural Modeling Analysis of CYP2D6 Mutations in Human Cancers.

Single nucleotide polymorphisms (SNPs) in cytochrome P450 (CYP450) enzymes alter the metabolism of a variety of drugs. Numerous medications, including chemotherapies, are metabolized by CYP450 enzymes, making the expression of this suite of enzymes in tumor cells relevant to prescription regimens for cancer patients. We analyzed the characteristics of mutations of the CYP2D6 enzymes in cancer patients obtained from the Catalogue of Somatic Mutations in Cancer (COSMIC), including mutation type, age of the patient, tissue type, and histology. Mutations were analyzed through the Cancer-Related Analysis of Variants Toolkit (CRAVAT) software along with CHASM and VEST4 algorithms to determine the likelihood of being a driver and/or pathogenic mutation. For mutations with significant CHASM and VEST4 scores, structural analysis of each corresponding mutant protein was performed. The effect of each mutation was evaluated for its impact on the overall protein stability and ligand binding using Foldit Standalone and SwissDock, respectively. Structural analysis revealed that several missense mutations in CYP2D6 resulted in altered stability after energy minimization. Three missense mutations of CYP2D6 significantly altered docking stability and those located on alpha-helices near the docking site had a more significant impact than those not found in secondary protein structures. In conclusion, we have identified a series of mutations to CYP2D6 enzymes with possible relevance to cancer pathologies. Significance Statement CYP2D6 is responsible for the metabolism of many anti-cancer drugs. This study identified and characterized a series of mutations in the CYP2D6 enzyme that occurred in tumors. We found it likely that many of these mutations would alter enzyme function, leading to changes in drug metabolism in the tumor. We provide a basis for predicting the likelihood of a patient carrying these mutations to identify patients who may benefit from a precision medicine approach to drug selection and dosing.

Examining dietary supplements containing Euterpe oleracea Mart. (açaí) for potential botanical-drug interactions involving CYP3A4 inhibition

BackgroundBotanical dietary supplements (BDS) are consumed more by cancer patients than otherwise healthier patients to alleviate side effects of chemotherapy drugs or increase quality of life. The enzyme responsible for the metabolism of most anticancer drugs is CYP3A4, an enzyme predominantly located in the liver. HypothesisOur research team examined the potential risk between CYP3A4-interactive cancer drugs and Euterpe oleracea Mart. (açaí) berry and found that the compounds that passively and non-passively diffused from methanol açaí extract displayed significant inhibition of liver CYP3A4 – suggesting the potential for interactions between açaí and drugs metabolized by CYP3A4 if used synchronously. This study aims to identify the compounds responsible for the CYP3A4 inhibition using the newly automated Bioactivity – Global Natural Product Social Molecular Networking (GNPS) tool. MethodsDietary supplement capsules from two manufacturers (F1 and F2) containing aqueous extracts of açaí fruits were extracted separately by methanol (ME) and acidic methanol (AC) and standardized to cyanidin-3-O-glucoside (CG) concentration at a human-relevant dose. After solvent removal, a parallel artificial membrane permeability assay (PAMPA) was utilized to filter intestinal passive diffusion of the four extract constituents so that compounds could be tested for inhibition of hepatic CYP3A4. Passively and non-passively diffused constituents of extracts from PAMPA assays were injected into the liquid chromatography-mass spectrometry (LC–MS) and characterized for visualization and comparison of chemical entities. To elucidate the non-passively diffused compounds responsible for significant CYP3A4 inhibition, the Bioactivity – GNPS tool was used to hypothesize which compounds within the formulation extract were potentially active to accelerate their identification. ResultsThere was no significant inhibition of CYP3A4 by passively diffused constituents for any extract. There was, however, significant inhibition by non-passively diffused constituents of both F1ME and F1AC extracts with 50 % CYP3A4 inhibition at the donor compartment concentrations 5.764 and 15.58 ng/ml CG, respectively. Six compounds were predicted to be inhibitors of CYP3A4 from methanol F1 extract, including betaine and 5 unknown compounds. ConclusionThis indicates that BDS containing açaí may not inhibit CYP3A4 through passively diffused compounds. Compounds from açaí BDS that inhibit CYP3A4 may be absorbed through other mechanisms, such as transporters.

Germline cis variant determines epigenetic regulation of the anti-cancer drug metabolism gene dihydropyrimidine dehydrogenase (DPYD)

Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome-edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.

Germline cis variant determines epigenetic regulation of the anti-cancer drug metabolism gene dihydropyrimidine dehydrogenase (DPYD).

Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome-edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.

Association between the MDR1 rs1045642 polymorphism and breast cancer risk: An updated meta‑analysis.

Multidrug resistance 1 (MDR1) is a transmembrane transporter on the cell membrane. As an ATP-dependent efflux pump, MDR1 is mainly responsible for the adsorption, distribution, metabolism, excretion and transportation of anticancer drugs to cancer cells. Mutations of the MDR1 gene may be associated with the incidence of cancer. In the past decade, associations found between the MDR1 rs1045642 polymorphism and breast cancer have been inconsistent and inconclusive. Therefore, the present study performed a meta-analysis including studies published up until August 16, 2023 to systematically evaluate the association between the MDR1 rs1045642 polymorphism and breast cancer risk. A total of 21 published case studies involving 6,815 patients with breast cancer and 9,227 healthy participants were included in the meta-analysis. Overall, the MDR1 rs1045642 polymorphism was not significantly associated with breast cancer-associated risk. However, in the subgroup analysis, the MDR1 rs1045642 polymorphism was found to be notably associated with a higher risk of breast cancer among Asian populations in recessive models [TT vs. CT + CC; odds ratio (OR)=1.393; 95% confidence interval (CI), 1.143-1.698; P=0.001; I2<25%]. The MDR1 C3435T polymorphism was also associated with a notable decrease in the incidence of breast cancer in mixed ethnicity populations (TT and CT + CC; OR=0.578; 95% CI, 0.390-0.856; P=0.006; I2<25%). In Caucasian populations, the MDR1 rs1045642 polymorphism was not associated with breast cancer risk. In conclusion, the present meta-analysis demonstrated that the MDR1 rs1045642 polymorphism may increase the risk of breast cancer in Asian populations, is associated with a reduced risk of breast cancer in mixed populations but has no notable effect in Caucasian populations.

When cancer drug resistance meets metabolomics (bulk, single-cell and/or spatial): Progress, potential, and perspective.

Resistance to drug treatment is a critical barrier in cancer therapy. There is an unmet need to explore cancer hallmarks that can be targeted to overcome this resistance for therapeutic gain. Over time, metabolic reprogramming has been recognised as one hallmark that can be used to prevent therapeutic resistance. With the advent of metabolomics, targeting metabolic alterations in cancer cells and host patients represents an emerging therapeutic strategy for overcoming cancer drug resistance. Driven by technological and methodological advances in mass spectrometry imaging, spatial metabolomics involves the profiling of all the metabolites (metabolomics) so that the spatial information is captured bona fide within the sample. Spatial metabolomics offers an opportunity to demonstrate the drug-resistant tumor profile with metabolic heterogeneity, and also poses a data-mining challenge to reveal meaningful insights from high-dimensional spatial information. In this review, we discuss the latest progress, with the focus on currently available bulk, single-cell and spatial metabolomics technologies and their successful applications in pre-clinical and translational studies on cancer drug resistance. We provide a summary of metabolic mechanisms underlying cancer drug resistance from different aspects; these include the Warburg effect, altered amino acid/lipid/drug metabolism, generation of drug-resistant cancer stem cells, and immunosuppressive metabolism. Furthermore, we propose solutions describing how to overcome cancer drug resistance; these include early detection during cancer initiation, monitoring of clinical drug response, novel anticancer drug and target metabolism, immunotherapy, and the emergence of spatial metabolomics. We conclude by describing the perspectives on how spatial omics approaches (integrating spatial metabolomics) could be further developed to improve the management of drug resistance in cancer patients.

Effects of CYP3A43 Expression on Cell Proliferation and Migration of Lung Adenocarcinoma and Its Clinical Significance.

The cytochrome P450s (CYP450s) include key oxidative enzymes involved in the metabolism of various carcinogens and anticancer drugs. Bioinformatic studies have demonstrated the association of CYP3A43 with liver cancer and ovarian cancer. However, the biological function of CYP3A43 in tumor progression remains unclear. To further reveal the role of CYP3A43 in tumor progression, we first analyzed the data from the UALCAN database and found that CYP3A43 was negatively correlated to the cancer staging and lymph node metastasis of lung adenocarcinoma (LUAD). We established stable CYP3A43-knockdown LUAD H1299 cell line and found that its knockdown enhanced cell proliferation, colony formation, and migration in vitro, and promoted the growth of tumor xenograft in vivo. Interestingly, when CYP3A43 was ectopically-expressed in the LUAD cell lines, decreased cell proliferation and ERK1/2 phosphorylation level were observed. Lastly, we also identified CYP3A43 co-expressed genes in LUAD from LinkedOmics database followed by GO and KEGG analyses. In conclusion, our results indicate the unprecedented role of CYP3A43 in the suppression of LUAD and provide new possibilities for targeted therapy of this life-threatening disease.

The Somatic Mutation Landscape of UDP-Glycosyltransferase (UGT) Genes in Human Cancers.

The human UDP-glycosyltransferase (UGTs) superfamily has a critical role in the metabolism of anticancer drugs and numerous pro/anti-cancer molecules (e.g., steroids, lipids, fatty acids, bile acids and carcinogens). Recent studies have shown wide and abundant expression of UGT genes in human cancers. However, the extent to which UGT genes acquire somatic mutations within tumors remains to be systematically investigated. In the present study, our comprehensive analysis of the somatic mutation profiles of 10,069 tumors from 33 different TCGA cancer types identified 3427 somatic mutations in UGT genes. Overall, nearly 18% (1802/10,069) of the assessed tumors had mutations in UGT genes with huge variations in mutation frequency across different cancer types, ranging from over 25% in five cancers (COAD, LUAD, LUSC, SKCM and UCSC) to less than 5% in eight cancers (LAML, MESO, PCPG, PAAD, PRAD, TGCT, THYM and UVM). All 22 UGT genes showed somatic mutations in tumors, with UGT2B4, UGT3A1 and UGT3A2 showing the largest number of mutations (289, 307 and 255 mutations, respectively). Nearly 65% (2260/3427) of the mutations were missense, frame-shift and nonsense mutations that have been predicted to code for variant UGT proteins. Furthermore, about 10% (362/3427) of the mutations occurred in non-coding regions (5' UTR, 3' UTR and splice sites) that may be able to alter the efficiency of translation initiation, miRNA regulation or the splicing of UGT transcripts. In conclusion, our data show widespread somatic mutations of UGT genes in human cancers that may affect the capacity of cancer cells to metabolize anticancer drugs and endobiotics that control pro/anti-cancer signaling pathways. This highlights their potential utility as biomarkers for predicting therapeutic efficacy and clinical outcomes.

Influence of cytochrome P450 3A4 and membrane lipid composition on doxorubicin activity

Drug resistance is known to depend on the interactions with cell membranes and other molecules such as human cytochromes P450 (CYPs) which are anchored on the endoplasmic reticulum (ER) membrane and involved in the metabolism of anticancer drugs. In this study, we determined the influence from cytochrome P450 3A4 (CYP3A4) on the interaction between the drug doxorubicin (DOX) and Langmuir monolayers mimicking cell membranes. The lipid composition was varied by changing the relative concentrations of cholesterol (Chol), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and L-α-phosphatidylinositol (PI). Three compositions were studied in detail which represented a healthy cell membrane and cancerous cell membranes. DOX induced an expansion in the surface pressure isotherms for all monolayers, with stronger effect for the composition of cancerous cell with a high Chol content, thus confirming the relevance of lipid composition. This effect decreased considerably when CYP3A4 was incorporated with the formation of CYP3A4-DOX complexes, according to results from polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) measurements. Taken together, these results support the hypothesis of CYP3A4 being involved in drug resistance, which may be exploited to design strategies to enhance chemotherapy efficacy.

Host and gut bacteria share metabolic pathways for anti-cancer drug metabolism.

Pharmaceuticals have extensive reciprocal interactions with the microbiome, but whether bacterial drug sensitivity and metabolism is driven by pathways conserved in host cells remains unclear. Here we show that anti-cancer fluoropyrimidine drugs inhibit the growth of gut bacterial strains from 6 phyla. In both Escherichia coli and mammalian cells, fluoropyrimidines disrupt pyrimidine metabolism. Proteobacteria and Firmicutes metabolized 5-fluorouracil to its inactive metabolite dihydrofluorouracil, mimicking the major host mechanism for drug clearance. The preTA operon was necessary and sufficient for 5-fluorouracil inactivation by E. coli, exhibited high catalytic efficiency for the reductive reaction, decreased the bioavailability and efficacy of oral fluoropyrimidine treatment in mice and was prevalent in the gut microbiomes of colorectal cancer patients. The conservation of both the targets and enzymes for metabolism of therapeutics across domains highlights the need to distinguish the relative contributions of human and microbial cells to drug efficacy and side-effect profiles.

222P Is quality of life (QoL) during chemotherapy affected by body composition?

Clinical studies conducted in patients with different types of tumours showed a significant influence of body composition on the metabolism of anticancer drugs and consequently on the response to treatment and its toxicity which could affect the overall prognosis. Available data clearly defines the impact of chemotherapy and its side effects on QoL of breast cancer patients, however there have been few studies that have analysed the impact of body composition on chemotherapy tolerance as well as on the QoL of breast cancer patients in the course of treatment.

Inhibitory effects of Thai herbal extracts on the cytochrome P450 3A-mediated the metabolism of gefitinib, lapatinib and sorafenib

Herbal products are widely used in cancer patients via co−administration with chemotherapy. Previous studies have demonstrated that pharmacokinetic interactions between herbs and anticancer drugs exist due to inhibition of drug−metabolizing enzymes, particularly cytochrome P450s (CYPs). The aim of this study was to determine the inhibitory effects of Andrographis paniculata, Curcuma zedoaria, Ganoderma lucidum, Murdannia loriformis and Ventilago denticulata extracts on the metabolism of gefitinib, lapatinib and sorafenib. The activities of CYP3A in human liver microsome on the metabolism of gefitinib, lapatinib and sorafenib in the absence and presence of Thai herbal extracts were assayed using high-performance liquid chromatography analysis. Curcuma zedoaria extract potently inhibited CYP3A−mediated lapatinib and sorafenib metabolism with IC50 values of 4.18 ± 3.20 and 7.59 ± 1.23 μg/mL, respectively, while the metabolism of gefitinib was strongly inhibited by Murdannia loriformis and Ventilago denticulata extracts with IC50 values of 7.53 ± 2.87 and 7.06 ± 1.23 μg/mL, respectively. Andrographis paniculata and Ganoderma lucidum extracts had less effect on the metabolism of the tested anticancers (IC50 values >10 μg/mL). In addition, kinetic analysis of the ability of Curcuma zedoaria extract to inhibit CYP3A-mediated metabolism of anticancer drugs was best described by the noncompetitive and competitive inhibition models with Ki values of 20.08 and 11.55 μg/mL for the metabolism of gefitinib and sorafenib, respectively. The present study demonstrated that there were potential pharmacokinetic interactions between tyrosine kinase inhibitors and herbal extracts.

Circadian Timekeeping in Anticancer Therapeutics: An Emerging Vista of Chronopharmacology Research.

Intrinsic rhythms in host and cancer cells play an imperative role in tumorigenesis and anticancer therapy. Circadian medicine in cancer is principally reliant on the control of growth and development of cancer cells or tissues by targeting the molecular clock and implementing time-of-day-based anticancer treatments for therapeutic improvements. In recent years, based on extensive high-throughput studies, we witnessed the arrival of several drugs and drug-like compounds that can modulate circadian timekeeping for therapeutic gain in cancer management. This perspective article intends to illustrate the current trends in circadian medicine in cancer, focusing on clock-modulating pharmacological compounds and circadian regulation of anticancer drug metabolism and efficacy. Scope and Approach: Considering the critical roles of the circadian clock in metabolism, cell signaling, and apoptosis, chronopharmacology research is exceedingly enlightening for understanding cancer biology and improving anticancer therapeutics. In addition to reviewing the relevant literature, we investigated the rhythmic expression of molecular targets for many anticancer drugs frequently used to treat different cancer types. Key Findings and Conclusion: There are adequate empirical pieces of evidence supporting circadian regulation of drug metabolism, transport, and detoxification. Administration of anticancer drugs at specific dosing times can improve their effectiveness and reduce the toxic effects. Moreover, pharmacological modulators of the circadian clock could be used for targeted anticancer therapeutics such as boosting circadian rhythms in the host can markedly reduce the growth and viability of tumors. All in all, precision chronomedicine can offer multiple advantages over conventional anticancer therapy.

Novel nanomedicines to overcome cancer multidrug resistance.

Chemotherapy remains a powerful tool to eliminate malignant cells. However, the efficacy of chemotherapy is compromised by the frequent emergence of intrinsic and acquired multidrug resistance (MDR). These chemoresistance modalities are based on a multiplicity of molecular mechanisms of drug resistance, including : 1) Impaired drug uptake into cancer cells; 2) Increased expression of ATP-binding cassette efflux transporters; 3) Loss of function of pro-apoptotic factors; 4) Enhanced DNA repair capacity; 5) Qualitative or quantitative alterations of specific cellular targets; 6) Alterations that allow cancer cells to tolerate adverse or stressful conditions; 7) Increased biotransformation or metabolism of anticancer drugs to less active or completely inactive metabolites; and 8) Intracellular and intercellular drug sequestration in well-defined organelles away from the cellular target. Hence, one of the major aims of cancer research is to develop novel strategies to overcome cancer drug resistance. Over the last decades, nanomedicine, which focuses on targeted delivery of therapeutic drugs into tumor tissues using nano-sized formulations, has emerged as a promising tool for cancer treatment. Therefore, nanomedicine has been introduced as a reliable approach to improve treatment efficacy and minimize detrimental adverse effects as well as overcome cancer drug resistance. With rationally designed strategies including passively targeted delivery, actively targeted delivery, delivery of multidrug combinations, as well as multimodal combination therapy, nanomedicine paves the way towards efficacious cancer treatment and hold great promise in overcoming cancer drug resistance. Herein, we review the recent progress of nanomaterials used in medicine, including liposomal nanoparticles, polymeric nanoparticles, inorganic nanoparticles and hybrid nanoparticles, to surmount cancer multidrug resistance. Finally, the future perspectives of the application of nanomedicine to reverse cancer drug resistance will be addressed.

Pharmacogenetic markers of chemotherapy toxicity in gastrointestinal tumors: a preliminary analysis

Aim. To assess the association between the carriage of minor allelic variants of 8 genes that encode key enzymes involved in the metabolism of anticancer drugs (DPYD, GSTP1, MTHFR, UGT1A1) and cell repair (XPC, ERCC1, TYMP, NQO1) and the severity of adverse drug events in patients with common gastrointestinal tumors. Tasks. To study the frequency of minor allelic variants of the DPYD, GSTP1, MTHFR, UGT1A1, XPC, ERCC1, TYMP, NQO1 genes; to assess the frequency and severity of adverse drug events of chemotherapy treatment in the study population. Materials and methods. For the period from October 2020 to April 2021, 56 patients (women 29, men 27) with verified malignant tumors of the gastrointestinal tract were included in a prospective clinical study as a part of the RSF grant No. 20-75-10158. The mean age was 62.311.4 years. Colon cancer was detected in 24 patients, tumors of the esophagus and stomach in 19 patients, tumors of pancreas and biliary tract in 13 patients. First-line palliative chemotherapy was given to 27 patients, adjuvant 19 patients, neoadjuvant 10 patients. All patients had not previously received cytotoxic or radiation treatment. Point nucleotide variants of genes DPYD, XPC, GSTP1, MTHFR, ERCC1, UGT1A1, TYMPS, NQO1 were determined by hybridization analysis on biological microchips. Differences in the tolerance of cytotoxic therapy (5-fluorouracil, platinum preparations, irinotecan) depending on the genotype were assessed using Fishers exact test. Results. The average number of chemotherapy courses received was 4.22.6 (112). There was a statistically significant difference in the tolerability of chemotherapy in patients with minor allelic variants of the GSTP1 rs1695 (p=0.03), ERCC1 rs11615 (p=0.01), and UGT1A1 rs8175347 (p=0.003) genes. Conclusion. The use of hybridization analysis on biological microchips to assess allelic variants responsible for the tolerability of cytotoxic therapy is reasonable and requires further prospective assessment.

CYP2B6 Functional Variability in Drug Metabolism and Exposure Across Populations-Implication for Drug Safety, Dosing, and Individualized Therapy.

Adverse drug reactions (ADRs) are one of the major causes of morbidity and mortality worldwide. It is well-known that individual genetic make-up is one of the causative factors of ADRs. Approximately 14 million single nucleotide polymorphisms (SNPs) are distributed throughout the entire human genome and every patient has a distinct genetic make-up which influences their response to drug therapy. Cytochrome P450 2B6 (CYP2B6) is involved in the metabolism of antiretroviral, antimalarial, anticancer, and antidepressant drugs. These drug classes are commonly in use worldwide and face specific population variability in side effects and dosing. Parts of this variability may be caused by single nucleotide polymorphisms (SNPs) in the CYP2B6 gene that are associated with altered protein expression and catalytic function. Population variability in the CYP2B6 gene leads to changes in drug metabolism which may result in adverse drug reactions or therapeutic failure. So far more than 30 non-synonymous variants in CYP2B6 gene have been reported. The occurrence of these variants show intra and interpopulation variability, thus affecting drug efficacy at individual and population level. Differences in disease conditions and affordability of drug therapy further explain why some individuals or populations are more exposed to CYP2B6 pharmacogenomics associated ADRs than others. Variabilities in drug efficacy associated with the pharmacogenomics of CYP2B6 have been reported in various populations. The aim of this review is to highlight reports from various ethnicities that emphasize on the relationship between CYP2B6 pharmacogenomics variability and the occurrence of adverse drug reactions. In vitro and in vivo studies evaluating the catalytic activity of CYP2B6 variants using various substrates will also be discussed. While implementation of pharmacogenomic testing for personalized drug therapy has made big progress, less data on pharmacogenetics of drug safety has been gained in terms of CYP2B6 substrates. Therefore, reviewing the existing evidence on population variability in CYP2B6 and ADR risk profiles suggests that, in addition to other factors, the knowledge on pharmacogenomics of CYP2B6 in patient treatment may be useful for the development of personalized medicine with regards to genotype-based prescription.

Potential cytochrome P450-mediated pharmacokinetic interactions between herbs, food, and dietary supplements and cancer treatments.

Herbs, food and dietary supplements (HFDS), can interact significantly with anticancer drug treatments via cytochrome p450 isoforms (CYP) CYP3A4, CYP2D6, CYP1A2, and CYP2C8. The objective of this review was to assess the influence of HFDS compounds on these cytochromes. Interactions with CYP activities were searched for 189 herbs and food products, 72 dietary supplements in Web of Knowledge® databases. Analyses were made from 140 of 3125 clinical trials and 236 of 3374 in vitro, animal model studies or case reports. 18 trials were found to report direct interactions between 9 HFDS with 8 anticancer drugs. 21 HFDS were found to interact with CYP3A4, a major metabolic pathway for many anticancer drugs. All 261 HFDS were classified for their interaction with the main cytochromes P450 involved in the metabolism of anticancer drugs. We provided an easy-to-use colour-coded table to easily match potential interactions between 261 HFDS and 117 anticancer drugs.

Decoding variants in drug-metabolizing enzymes and transporters in solid tumor patients by whole-exome sequencing.

BackgroundPharmacogenetics is involved in customizing therapy according to the genetic makeup of an individual, and is applicable for chemotherapy, radiotherapy as well as targeted therapy. Drug metabolizing enzymes (DMEs) involving both phase I, and phase II reactions are widely studied. Our study was involved in whole exome sequencing (WES) of cancer patients, followed by analysis for identifying key variations in DMEs, and associated transporters that have a potential impact on treatment outcome.MethodologyA total of 181 solid tumor patients at stage >/= III were subjected to WES by the SureSelectXT Human All Exon V6 + UTR library preparation kit, and sequencing in the Illumina NextSeq 550 system. Bioinformatics analysis involved use of GATK pipeline, and the variants were further assessed for population frequency, functional impact with annovar insilico algorithms. Further variant information from significant DMEs, and transporters were extracted and analyzed with PharmGKB to assess level of evidence and infer their impact on the pathways involved in drug response.ResultsThe total study cohort of 181 solid tumor patients included 60 males, and 121 females respectively. Among DMEs, deleterious mutation in dihydropyrimidine dehydrogenase (DPYD; rs67376798), solute carrier organic anion transporter family member 1B1 (SLCO1B1*5), and cytochrome P450 2D6 (CYP2D6*10) associated with metabolism of anticancer drugs was detected to be in high frequency of 26%, 21% and 25% respectively.ConclusionOur analysis detected variations in both phase I and phase II DMEs, as well as associated transporter genes which has been documented to reduce drug efficacy, as well as cause grade 3 and 4 toxicity. Our study reiterates the significance of pharmacogenomics in stratifying patients for appropriate therapy regimen focused at better treatment outcome and quality of life.

The association between genetic variants in the genes for cytochrome P450 B1 and ATP-binding cassette transporter genes and breast cancer risk.

Breast cancer is among the most common malignancies in women. Recent studies have shown that polymorphisms in genes involved in the metabolism and transport of anticancer drugs are associated with outcomes of several malignancies, e.g., breast cancer. In this study we evaluate whether CYP1B1/rs1056836 and ABCB1/rs2032582 gene variants are associated with breast cancer. Eighty eight cases and 200 controls, were genotyped for polymorphisms of the CYP1B1 and ABCB1 genes using Taqman®-based methods. Logistic regression was also used to test the associations between breast cancer risk and the various genotypes involved. The GG genotype of rs2032582 locus had a frequency of 43.5% with 0.38 MAF; while the GT and TT genotypes in the control group were 40% and 16.5%, respectively. The GG, GT and TT genotype frequencies in the patients with breast cancer were 45.5%, 12.5% and 26.1%, respectively. An association was observed between the TT genotype of ABCB1/rs2032582 locus and a larger breast cancer tumor size (P < 0.05). However, neither the relationship between the CYP1B1 polymorphism and breast cancer type nor the risk of breast cancer were statistically significant. Our data suggest a potential association of the ABCB1 genetic variant with breast cancer tumor size, however further investigation in a larger population is necessary to show its value as a risk stratification biomarker.

Drug-metabolizing enzymes: role in drug resistance in cancer.

Although continuous researches are going on for the discovery of new chemotherapeutic agents, resistance to these anticancer agents has made it really difficult to reach the fruitful results. There are many causes for this resistance that are being studied by the researchers across the world, but still, success is far because there are several factors that are going along unattended or have been studied less. Drug-metabolizing enzymes (DMEs) are one of these factors, on which less study has been conducted. DMEs include Phase I and Phase II enzymes. Cytochrome P450s (CYPs) are major Phase I enzymes while glutathione-S-transferases (GSTs), UDP-glucuronosyltransferases (UGTs), dihydropyrimidine dehydrogenases are the major enzymes belonging to the Phase II enzymes. These enzymes play an important role in detoxification of the xenobiotics as well as the metabolism of drugs, depending upon the tissue in which they are expressed. When present in tumorous tissues, they cause resistance by metabolizing the drugs and rendering them inactive. In this review, the role of these various enzymes in anticancer drug metabolism and the possibilities for overcoming the resistance have been discussed.