Dual approach: micellar delivery of chlorambucil prodrug with concurrent glutathione depletion and GST inhibition for enhanced anticancer activity.

Although chlorambucil (CHL) is a long-established anticancer drug, the drug failure of CHL, mediated by the intracellular defense system consisting of glutathione (GSH) and GSH S-transferase pi (GST-pi), has significantly limited the application of CHL. To overcome this issue, we first designed a GSH-responsive small-molecule prodrug (EA-SS-CHL) by combining CHL and ethacrynic acid (EA). Subsequently, drug-loaded nanoparticles (ECPP) were formed by the self-assembly between EA-SS-CHL and amphiphilic PEG-PDLLA to improve the water solubility of the prodrug and its ability to target tumor sites. Upon exposure to high intracellular GSH concentration, EA-SS-CHL gradually degrades, leading to the release of EA and CHL. The presence of EA facilitates the depletion of GSH and inhibition of GST-pi, ultimately attenuating the detoxification of the intracellular defense system to CHL. Cytotoxicity studies and apoptosis assays demonstrate that ECPP exhibits higher therapeutic efficiency than CHL. Additionally,in vivotumor suppression effects and biocompatibility provide further evidence for the superiority of ECPP. This work presents a promising strategy to enhance the efficacy of CHL in cancer therapy.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell.

BACKGROUND: Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation. PURPOSE: The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation. METHODS: The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay. RESULTS: Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation. CONCLUSION: Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

Voluntary running exercise modifies astrocytic population and features in the peri-infarct cortex.

Rehabilitative exercise following a brain stroke has beneficial effects on the morphological plasticity of neurons. Particularly, voluntary running exercise after focal cerebral ischemia promotes functional recovery and ameliorates ischemia-induced dendritic spine loss in the peri-infarct motor cortex layer 5. Moreover, neuronal morphology is affected by changes in the perineuronal environment. Glial cells, whose phenotypes may be altered by exercise, are known to play a pivotal role in the formation of this perineuronal environment. Herein, we investigated the effects of voluntary running exercise on glial cells after middle cerebral artery occlusion. Voluntary running exercise increased the population of glial fibrillary acidic protein-positive astrocytes born between post-operative days (POD) 0 and 3 on POD15 in the peri-infarct cortex. After exercise, transcriptomic analysis of post-ischemic astrocytes revealed 10 upregulated and 70 downregulated genes. Furthermore, gene ontology analysis showed that the 70 downregulated genes were significantly associated with neuronal morphology. In addition, exercise reduced the number of astrocytes expressing lipocalin 2, a regulator of dendritic spine density, on POD15. Our results suggest that exercise modifies the composition of astrocytic population and their phenotype.

Targeting GSTP1 as Therapeutic Strategy against Lung Adenocarcinoma Stemness and Resistance to Tyrosine Kinase Inhibitors.

Glutathione S-transferase pi (GSTP1), a phase II detoxification enzyme, is known to be overexpressed and mediates chemotherapeutic resistance in lung cancer. However, whether GSTP1 supports cancer stem cells (CSCs) and the underlying mechanisms in lung adenocarcinoma (LUAD) remain largely unknown. This study unveiled that GSTP1 is upregulated in lung CSCs and supports tumor self-renewal, metastasis, and resistance to targeted tyrosine kinase inhibitors of LUAD both in vitro and in vivo. Mechanistically, CaMK2A (calcium/calmodulin-dependent protein kinase 2 isoform A)/NRF2 (nuclear factor erythroid 2-related factor 2)/GSTP1 is uncovered as a regulatory axis under hypoxia. CaMK2A increased GSTP1 expression through phosphorylating the Sersine558 residue of NRF2 and promoting its nuclear translocation, a novel mechanism for NRF2 activation apart from conventional oxidization-dependent activation. Upregulation of GSTP1 in turn suppressed reactive oxygen species levels and supported CSC phenotypes. Clinically, GSTP1 analyzed by immunohistochemistry is upregulated in a proportion of LUAD and serves as a prognostic marker for survival. Using patient-derived organoids from an ALK-translocated LUAD, the therapeutic potential of a specific GSTP1 inhibitor ezatiostat in combination treatment with the ALK inhibitor crizotinib is demonstrated. This study demonstrates GSTP1 to be a promising therapeutic target for long-term control of LUAD through targeting CSCs.

Guhong injection mitigates myocardial ischemia/reperfusion injury by activating GST P to inhibit ASK1-JNK/p38 pathway.

BACKGROUND: Guhong injection (GHI), a novel compound preparation that is composed of a chemical drug, namely aceglutamide, and the aqueous extract of safflower (Carthamus tinctorius L.), exhibits extreme antioxidative, antiapoptotic, anti-inflammatory, and neuroprotective effects. Since oxidative stress, apoptosis, and inflammatory response are all the dominant mechanisms of myocardial ischemia/reperfusion (MI/R) injury, we probe into the protective mechanism of GHI on MI/R injury for the first time. METHODS: In this research, we first employed molecular docking to determine whether three active ingredients in GHI, acetylglutamine (NAG), hydroxysafflor yellow A (HSYA), and syringin, possessed the potential activity to modulate the protein, glutathione S-transferase P (GST P). We further identified the protective effect of GHI on myocardial tissue with TTC staining, HE staining, TUNEL staining, and ELISA, and on H9c2 with flow cytometry and ELISA. We next explored whether the cardioprotective effect of GHI on left anterior descending ligation-reperfusion in rats and hypoxia/reoxygenation (H/R) in H9c2 cells was related to activate GST P to inhibit ASK1-JNK/p38 pathway via approaches of qRT-PCR and Western blot. RESULTS: Results of molecular docking indicated that all three compounds spontaneously docked to GST P, among them the binding affinities of both HSYA and syringin to GST P were higher than NAG. In vivo, GHI reduced myocardial infarction size and mitigated myocardial pathological injury. In vitro, GHI enhanced cell viability and extenuated depolarization of mitochondrial membrane potential. In addition, the results of in vivo and in vitro studies demonstrated that the cardioprotection of GHI was associated with improving the mRNA and protein expression levels of GST P to modulate oxidative stress, and inhibiting the levels of mRNA expression and protein phosphorylation of ASK1, JNK, and p38. However, the suppressed effect of GHI on ASK1-JNK/p38 pathway was reversed by ethacrynic acid (EA, a GST inhibitor), indicating that the regulation of GHI on ASK1-JNK/p38 was related to the activity of GST P. Besides, the in vitro results of qRT-PCR and western-blot also certified that the inhibited JNK and p38 further reduced Bax expression and elevated Bcl-2 expression to reduce the expression of caspase-3 to exert anti-apoptosis effects. CONCLUSION: Taken together, the cardioprotection of GHI mainly incarnated in activating GST P to relieve oxidation properties, thereby inhibiting ASK1-JNK/p38 pathway to suppress apoptosis.

GUIDE: a randomised non-comparative phase II trial of biomarker-driven intermittent docetaxel versus standard-of-care docetaxel in metastatic castration-resistant prostate cancer (clinical trial protocol).

Objective: To determine the efficacy and safety of intermittent docetaxel chemotherapy guided by circulating methylated glutathione S-transferase Pi-1 (mGSTP1) in men with metastatic castration-resistant prostate cancer (CRPC). Patients and Methods: GUIDE (NCT04918810) is a randomised, two-arm, non-comparative phase-2 trial recruiting 120 patients at six Australian centres. Patients with Prostate Cancer Working Group-3 defined metastatic CRPC who are commencing docetaxel 75 mg/m2 q3w will be pre-screened for detectable mGSTP1 at baseline ± following two cycles of treatment. Those with detectable plasma mGSTP1 at baseline that becomes undetectable after two cycles of chemotherapy will be eligible for GUIDE. Prior to Cycle 4 of docetaxel, these patients are randomised 2:1 to one of two treatment arms: Arm A (cease docetaxel and reinstitute if mGSTP1 becomes detectable) or Arm B (continue docetaxel 75 mg/m2 q3w in accordance with clinician's usual practice). The primary endpoint is radiographic progression-free survival. Secondary endpoints include time on treatment holidays, safety, patient-reported outcomes, overall survival, health resource use, and cost associated with treatment. Enrolment commenced November 2021. Results and Conclusion: The results of this trial will generate data on the clinical utility of mGSTP1 as a novel biomarker to guide treatment de-escalation in metastatic CRPC.

Association between Genetic Polymorphism of GSTP1 and Toxicities in Patients Receiving Platinum-Based Chemotherapy: A Systematic Review and Meta-Analysis.

Platinum-based chemotherapy regimens have been proven to be effective in various cancers; however, considerable toxicities may develop and can even lead to treatment discontinuation. Diverse factors may influence adverse treatment events, with pharmacogenetic variations being one prime example. Polymorphisms within the glutathione S-transferase pi 1 (GSTP1) gene may especially alter enzyme activity and, consequently, various toxicities in patients receiving platinum-based chemotherapy. Due to a lack of consistency in the degree of elevated complication risk, we performed a systematic literature review and meta-analysis to determine the level of platinum-associated toxicity in patients with the GSTP1 rs1695 polymorphism. We conducted a systematic search for eligible studies published before January 2022 from PubMed, Web of Science, and EMBASE based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association between the rs1695 polymorphism and various toxicities. Ten eligible studies met the inclusion criteria. The pooled ORs for hematological toxicity and neutropenia in the patients with the variant (G) allele were 1.7- and 2.6-times higher than those with the AA genotype (95% CI 1.06-2.73 and 1.07-6.35), respectively. In contrast, the rs1695 polymorphism resulted in a 44% reduced gastrointestinal toxicity compared to wild-type homozygotes. Our study found that the GSTP1 rs1695 polymorphism was significantly correlated with platinum-induced toxicities. The study also revealed that rs1695 expression exhibited tissue-specific patterns and thus yielded opposite effects in different tissues. A personalized chemotherapy treatment based on these polymorphisms may be considered for cancer patients in the future.

Systematic analysis of potential targets of the curcumin analog pentagamavunon-1 (PGV-1) in overcoming resistance of glioblastoma cells to bevacizumab.

BACKGROUND: Glioblastoma is one of the most aggressive and deadliest malignant tumors. Acquired resistance decreases the effectiveness of bevacizumab in glioblastoma treatment and thus increases the mortality rate in patients with glioblastoma. In this study, the potential targets of pentagamavunone-1 (PGV-1), a curcumin analog, were explored as a complementary treatment to bevacizumab in glioblastoma therapy. METHODS: Target prediction, data collection, and analysis were conducted using the similarity ensemble approach (SEA), SwissTargetPrediction, STRING DB, and Gene Expression Omnibus (GEO) datasets. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted using Webgestalt and DAVID, respectively. Hub genes were selected based on the highest degree scores using the CytoHubba. Analysis of genetic alterations and gene expression as well as Kaplan-Meier survival analysis of selected genes were conducted with cBioportal and GEPIA. Immune infiltration correlations between selected genes and immune cells were analyzed with database TIMER 2.0. RESULTS: We found 374 targets of PGV-1, 1139 differentially expressed genes (DEGs) from bevacizumab-resistant-glioblastoma cells. A Venn diagram analysis using these two sets of data resulted in 21 genes that were identified as potential targets of PGV-1 against bevacizumab resistance (PBR). PBR regulated the metabolism of xenobiotics by cytochrome P450. Seven potential therapeutic PBR, namely GSTM1, AKR1C3, AKR1C4, PTGS2, ADAM10, AKR1B1, and HSD17B110 were found to have genetic alterations in 1.2%-30% of patients with glioblastoma. Analysis using the GEPIA database showed that the mRNA expression of ADAM10, AKR1B1, and HSD17B10 was significantly upregulated in glioblastoma patients. Kaplan-Meier survival analysis showed that only patients with low mRNA expression of AKR1B1 had significantly better overall survival than the patients in the high mRNA group. We also found a correlation between PBR and immune cells and thus revealed the potential of PGV-1 as an immunotherapeutic agent via targeting of PBR. CONCLUSION: This study highlighted seven PBR, namely, GSTM1, AKR1C3, AKR1C4, PTGS2, ADAM10, AKR1B1, and HSD17B110. This study also emphasized the potential of PBR as a target for immunotherapy with PGV-1. Further validation of the results of this study is required for the development of PGV-1 as an adjunct to immunotherapy for glioblastoma to counteract bevacizumab resistance.

Potential role of glutathione S-transferase P1 gene polymorphism and metabolic syndrome in lower urinary tract symptoms attributed to benign prostatic hyperplasia.

OBJECTIVE: The aim of the study is to investigate the effects of glutathione S-transferase P1 (GSTP1) gene polymorphism and metabolic syndrome (MS) on lower urinary tract symptoms (LUTS) attributed to benign prostatic hyperplasia (BPH). METHODS: This study included 195 patients diagnosed with LUTS secondary to BPH as case group, divided into simple BPH group (S-BPH group) and combined with MS group (MS-BPH group). Control group included 200 healthy elderly men without LUTS. Use peripheral blood samples detected the GSTP1 gene polymorphism (Ile 105 Val A → G polymorphism) by polymerase chain reaction-restriction fragment length polymorphism. Recorded age, GSTP1 gene polymorphism, international prostate symptom score (IPSS), prostate volume (PV), residual urine volume (RV), maximal urinary flowrate (Qmax), and prostate-specific antigen (PSA) to statistical analysis. RESULTS: Pairwise compared between control group, S-BPH group and MS-BPH, the PV (P < 0.001), PSA (P < 0.001), RV (P < 0.001), Qmax (P < 0.001), IPSS (P < 0.001), frequencies of GSTP1 gene (P < 0.05) were shown significant different, and MS-BPH group had larger PV, and more severe LUTS. In case group, variation genotypes (GSTP1 A/G + G/G) always had larger PV, higher PSA and IPSS, more RV and lower Qmax than homozygote (GSTP1 A/A) and the comparison were significant different (P < 0.05). Variation genotypes were positively correlated with PV (ß = 0.092, P < 0.001), RV (ß = 0.228, P = 0.004), IPSS (ß = 0.274, P = 0.038), PSA (ß = 1.243, P < 0.001) and negatively correlated with Qmax (ß = -0.362, P = 0.025). CONCLUSION: In patients with BPH, GSTP1 variation genotypes and MS might be potential risk factors for faster progression of benign prostatic enlargement and LUTS, which might increase the surgical rate. TRIAL REGISTRATION: ChiCTR-IPR-14005580.

An Ethacrynic Acid-Brominated BODIPY Photosensitizer (EA-BPS) Construct Enhances the Lethality of Reactive Oxygen Species in Hypoxic Tumor-Targeted Photodynamic Therapy.

Despite being a clinically approved intervention for cancer, photodynamic therapy (PDT) still suffers from limitations. Prime among these is a therapeutic response that is mostly oxygen dependent. This limits the utility of PDT in treating hypoxic tumors since lower levels of cytotoxic reactive oxygen species (ROS) are generated in regions of low oxygen tension. Glutathione-pi (GST-pi) is a key enzyme that militates against ROS-mediated apoptosis. We report herein a new construct, EA-BPS, that contains both a brominated BODIPY photosensitizer (BPS) and an ethacrynic acid (EA) GST-pi inhibitor. Photoirradiation of EA-BPS induces a synergistic antitumor effect that results from the combination of ROS production and GST-pi inhibition. Relative to BPS alone, an enhanced cell-killing effect is seen under hypoxic conditions both in vitro and in vivo. We conclude that by making better use of the available oxygen in tumor environments, improved therapeutic PDT outcomes should be achievable even under hypoxic conditions.

GSTP1 and cancer: Expression, methylation, polymorphisms and signaling (Review).

Glutathione S­transferase Pi (GSTP1) is an isozyme encoded by the GST pi gene that plays an important regulatory role in detoxification, anti­oxidative damage, and the occurrence of various diseases. The aim of the present study was to review the association between the expression of GSTP1 and the development and treatment of various cancers, and discuss GSTP1 methylation in several malignant tumors, such as prostate, breast and lung cancer, as well as hepatocellular carcinoma; to review the association between polymorphism of the GSTP1 gene and various diseases; and to review the effects of GSTP1 on electrophilic oxidative stress, cell signal transduction, and the regulation of carcinogenic factors. Collectively, GSTP1 plays a major role in the development of various diseases.

Effects of total parenteral nutrition on drug metabolism gene expression in mice.

Parenteral nutrition-associated liver disease (PNALD) is a liver dysfunction caused by various risk factors presented in patients receiving total parenteral nutrition (TPN). Omega-6 rich Intralipid® and omega-3 rich Omegaven® are two intravenous lipid emulsions used in TPN. TPN could affect the hepatic expression of genes in anti-oxidative stress, but it's unknown whether TPN affects genes in drug metabolism. In this study, either Intralipid®- or Omegaven®-based TPN was administered to mice and the expression of a cohort of genes involved in anti-oxidative stress or drug metabolism was analyzed, glutathione (GSH) levels were measured, and protein levels for two key drug metabolism genes were determined. Overall, the expression of most genes was downregulated by Intralipid®-based TPN (Gstp1, Gstm1, 3, 6, Nqo1, Ho-1, Mt-1, Gclc, Gclm, Cyp2d9, 2f2, 2b10, and 3a11). Omegaven® showed similar results as Intralipid® except for preserving the expression of Gstm1 and Cyp3a11, and increasing Ho-1. Total GSH levels were decreased by Intralipid®, but increased by Omegaven®. CYP3A11 protein levels were increased by Omegaven®. In conclusion, TPN reduced the expression of many genes involved in anti-oxidative stress and drug metabolism in mice. However, Omegaven® preserved expression of Cyp3a11, suggesting another beneficial effect of Omegaven® in protecting liver functions.

Antioxidant-Rich Diet, GSTP1 rs1871042 Polymorphism, and Gastric Cancer Risk in a Hospital-Based Case-Control Study.

BACKGROUND: Chronic gastritis along with Helicobacter pylori (H. pylori) infection has been implicated in inflammatory response-related genes linked to the causation of gastric cancer. Glutathione S-transferase Pi (GSTP1) plays a role in regulating oxidative stress and detoxification against carcinogenesis. In this study, we aimed to determine whether an antioxidant-rich diet is associated with gastric cancer risk and identify how this association could be altered by GSTP1 genetic variants. METHODS: This study included 1,245 participants (415 cases and 830 controls) matched for age and sex. The dietary antioxidant capacity was estimated based on the oxygen radical absorbance capacity (ORAC) incorporated with a semiquantitative food frequency questionnaire. Five single nucleotide polymorphisms (SNPs) of GSTP1 (rs1695, rs749174, rs1871042, rs4891, and rs947895) were selected among the exome array genotype data. RESULTS: High dietary ORAC was inversely associated with gastric cancer (hydrophilic ORAC OR T3 vs . T1, 95% CI = 0.57, 0.39-0.82, P = 0.004; lipophilic ORAC = 0.66, 0.45-0.95, P = 0.021; total phenolics = 0.57, 0.39-0.83, P = 0.005). The polymorphism rs1871042 increased the risk of gastric cancer (OR, 95% CI = 1.55, 1.10-2.16, P = 0.01, CT+TT vs. CC). A remarkably reduced risk of gastric cancer was observed among those who had a high dietary ORAC according to rs1871042 polymorphism (hydrophilic ORAC OR T3 vs . T1, 95% CI = 0.36, 0.17-0.78, P for trend = 0.013; lipophilic ORAC = 0.58, 0.37-0.93, P for trend = 0.021; total phenolics = 0.38, 0.17-0.83, P for trend = 0.019). CONCLUSIONS: Our findings indicate that dietary ORAC intake may be inversely associated with the risk of gastric cancer altered by genetic variants of GSTP1, providing new intervention strategies for gastric cancer patients.

Polymorphisms and endometriosis: a systematic review and meta-analyses.

BACKGROUND: Endometriosis is an estrogen-dependent gynecological disorder that affects at least 10% of women of reproductive age. It may lead to infertility and non-specific symptoms such as chronic pelvic pain. Endometriosis screening and diagnosis are difficult and time-consuming. Late diagnosis (with a delay ranging from 3.3 to 10.7 years) is a major problem and may contribute to disease progression and a worse response to treatment once initiated. Efficient screening tests might reduce this diagnostic delay. As endometriosis is presumed to be a complex disease with several genetic and non-genetic pathogenic factors, many researchers have sought to identify polymorphisms that predispose to this condition. OBJECTIVE AND RATIONALE: We performed a systematic review and meta-analysis of the most regularly reported polymorphisms in order to identify those that might predispose to endometriosis and might thus be of value in screening. SEARCH METHODS: The MEDLINE database was searched for English-language publications on DNA polymorphisms in endometriosis, with no date restriction. The PubTator text mining tool was used to extract gene names from the selected publications' abstracts. We only selected polymorphisms reported by at least three studies, having applied strict inclusion and exclusion criteria to their control populations. No stratification based on ethnicity was performed. All steps were carried out according to PRISMA guidelines. OUTCOMES: The initial selection of 395 publications cited 242 different genes. Sixty-two genes (corresponding to 265 different polymorphisms) were cited at least in three publications. After the application of our other selection criteria (an original case-control study of endometriosis, a reported association between endometriosis and at least one polymorphism, data on women of reproductive age and a diagnosis of endometriosis in the cases established by surgery and/or MRI and confirmed by histology), 28 polymorphisms were eligible for meta-analysis. Only five of the 28 polymorphisms were found to be significantly associated with endometriosis: interferon gamma (IFNG) (CA) repeat, glutathione S-transferase mu 1 (GSTM1) null genotype, glutathione S-transferase pi 1 (GSTP1) rs1695 and wingless-type MMTV integration site family member 4 (WNT4) rs16826658 and rs2235529. Six others showed a significant trend towards an association: progesterone receptor (PGR) PROGINS, interCellular adhesion molecule 1 (ICAM1) rs1799969, aryl-hydrocarbon receptor repressor (AHRR) rs2292596, cytochrome family 17 subfamily A polypeptide 1 (CYP17A1) rs743572, CYP2C19 rs4244285 and peroxisome proliferator-activated receptor gamma (PPARG) rs1801282), and 12 showed a significant trend towards the lack of an association: tumor necrosis factor (TNF) rs1799964, interleukin 6 (IL6) rs1800796, transforming growth factor beta 1 (TGFB1) rs1800469, estrogen receptor 1 (ESR1) rs2234693, PGR rs10895068, FSH receptor (FSHR) rs6166, ICAM1 rs5498, CYP1A1 rs4646903, CYP19A1 rs10046, tumor protein 53 (TP53) rs1042522, X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1) rs25487 and serpin peptidase inhibitor clade E member 1 (SERPINE1) rs1799889; however, for the 18 polymorphisms identified in the latter two groups, further studies of the potential association with the endometriosis risk are needed. The remaining five of the 28 polymorphisms were not associated with endometriosis: glutathione S-transferase theta 1 (GSTT1) null genotype, vascular endothelial growth factor alpha (VEGFA) rs699947, rs833061, rs2010963 and rs3025039. WIDER IMPLICATIONS: By carefully taking account of how the control populations were defined, we identified polymorphisms that might be candidates for use in endometriosis screening and polymorphisms not associated with endometriosis. This might constitute the first step towards identifying polymorphism combinations that predispose to endometriosis (IFNG (CA) repeat, GSTM1 null genotype, GSTP1 rs1695, WNT4 rs16826658 and WNT4 rs2235529) in a large cohort of patients with well-defined inclusion criteria. In turn, these results might improve the diagnosis of endometriosis in primary care. Lastly, our present findings may enable a better understanding of endometriosis and improve the management of patients with this disease.

Oridonin overcomes the gemcitabine resistant PANC-1/Gem cells by regulating GST pi and LRP/1 ERK/JNK signalling.

Background: Chemotherapy remains a primary treatment method for advanced pancreatic cancer. However, chemotherapy resistance can influence the therapeutic effect of pancreatic cancer. The resistance mechanism of chemotherapeutic agents such as gemcitabine, which is an agent typically used to treat pancreatic cancer, is complicated and can be influenced by genes and the environment. Oridonin is a tetracyclic diterpenoid compound extracted from the traditional Chinese herb Rabdosia labtea. Oridonin may overcome drug resistance in pancreatic cancer, but researching pancreatic cancer drug resistance of chemotherapy by oridonin is not completely understood. Purpose: The present study aimed to assess the impact of oridonin on multidrug resistance proteins, apoptosis-associated proteins and energy metabolism in gemcitabine-resistant PANC-1 (PANC-1/Gem) pancreatic cancer cells. Methods: Gemcitabine resistance in PANC-1/Gem cells was induced using a concentration gradient of gemcitabine. Cell Counting Kit-8 assays were used to detect the impact of gemcitabine and oridonin on the proliferation of PANC-1 and PANC-1/Gem cells. Western blot analysis and immunofluorescence were used to detect the expression of multidrug resistance proteins, apoptosis-associated proteins and low-density lipoprotein receptor protein 1 (LRP1) proteins in PANC-1/Gem cells. The effects of gemcitabine and oridonin on PANC-1/Gem cells apoptosis were detected using flow cytometry. Animal xenograft tumor assays were used to detect the effect of gemcitabine and oridonin on pancreatic cancer in vivo. Furthermore, the ATP Assay kit was used to determine the effects of gemcitabine and oridonin on ATP levels in PANC-1/Gem cells. Immunofluorescence assays were used to detect the effects of gemcitabine and oridonin on the expression of low-density lipoprotein receptor protein 1 (LRP1) in PANC-1/Gem cells. In addition, LRP1 expression was knocked down in PANC-1/Gem cells via lentiviral vector-mediated RNA silencing. Clone formation assays and Western blot analysis were used to detect the effect of LRP1 knockdown on the proliferation of PANC-1/Gem cells. Results: The present results demonstrate that oridonin overcomes PANC-1/Gem cells gemcitabine reistance by regulating GST pi and LRP1/ERK/JNK signaling. Conclusion: In conclusion, the present study indicated that oridonin could overcome gemcitabine resistance in PANC-1/Gem cells by regulating GST pi and LRP1/ ERK/JNK signaling, inducing cell apoptosis. Therefore, oridonin with gemcitabine may be a promising preoperative treatment for patients who suffer from pancreatic cancer.

The Relation between Polymorphisms in Exon 5 and Exon 6 of GSTP1 Gene and the Risk of Lung Cancer in Iranian People

Objective: The GSTP1 gene, which is located on chromosome 11q13, consists of 7 exons and 6 introns. There are two polymorphisms in GSTP1 that have been exposed to a transposition for codon 105 (Ile/Val) and 114 (Ala/Val) in exons 5 and 6, which have been studied previously in relation to lung cancer. Since the level of GSTP1 expression in lung tissues and other human epithelial tissues is high, GSTP1Val-105 polymorphism is recognized as a sensitive factor for tobacco-related cancers, especially lung cancer. Methods: One hundred and twenty tissue block samples of patients with lung cancers and 120 peripheral blood samples of the control group were obtained from two referral cancer centers in Tehran, Iran, from 2011 to 2016. Genomic DNA was extracted from tissue blocks and buffy coat of study cases to detect SNP of GSTP1 gene using Tetra-primer ARMS-PCR. Results: There was a notable correlation between the incidence of lung cancer and variant Val105 (P-value=0.001; OR=2/6; 95% CI=1.49-4.53) and Ile105 (P-value=0.003; OR=0.41; 95% CI=0.23-0.73). The odds ratio for lung cancer in the homozygous Ile105/Ile105 genotype was 3.56 times higher than that of individual with heterozygous Ile105/Val105 (P-value<0.001; OR=3/56; 95% CI=1.826-6.934) genotype, that was statistically significant. Furthermore, the results showed that there was no significant correlation between Ala114/Val114 genotypes and lung cancer. The BC (P-value=0.007; OR=0.16; 95% CI=0.04-0.61) and AA (P=0.001) genotypes were statistically significant (P-value <0.05); and for those who had AA genotype, the odds ratio was almost six times higher than those with BC genotype. Conclusions: The study of GSTP1 polymorphisms indicated that unlike the polymorphism in exon 5, the GSTP1 exon 6 polymorphism correlated with the lung cancer risk in the select group of Iranian people. Likewise, the potential use of this genetic polymorphism as a lung cancer predictor is confirmed.

GSTP1 as a potential predictive factor for adverse events associated with platinum-based antitumor agent-induced peripheral neuropathy.

Glutathione S-transferase (GST) exhibits antidotal effects on numerous drugs, including platinum-based antineoplastic drugs. Furthermore, GST Pi 1 (GSTP1) polymorphism is associated with peripheral neuropathy. In the present study, it was determined whether GSTP1 can predict adverse events associated with platinum-based antitumor agent-induced peripheral neuropathy among Japanese patients. The subjects included 122 patients, among whom 105 patients had colorectal, 16 had gastric, and one patient had pancreatic cancer. It was indicated that wild type (AA) GSTP1 was expressed in 99 patients (81.1%), whereas heterozygous (AG) and homozygous (GG) GSTP1 polymorphisms were present in 22 (18.0%) and 1 (0.8%) patients, respectively. Among patients with colorectal cancer, the expression of homozygous GSTP1 was observed in 88 patients (83.8%), whereas that of heterozygous GSTP1 was observed in 17 patients (16.2%). Peripheral neuropathy of grade ≥3 occurred in 10 patients (9.5%) receiving mFOLFOX therapy (a biweekly cycle consisting of a 2-h infusion of 85 mg/m2 oxaliplatin and 200 mg/m2 leucovorin followed by a bolus administration of 400 mg/m2 5-fluorouracil and a continuous 48-h infusion of 2,400 mg/m2 5-fluorouracil) for colorectal cancer, which included 6 patients with the AA allele (6.8%) and 4 patients with the AG allele (23.5%). The number of peripheral neuropathy cases of grade ≥3 was increased among patients with the AG allele, compared with patients with the AA allele (P=0.032). In patients with gastric cancer, the AA and AG types of GSTP1 were expressed in 11 (68.8%) and 5 (31.2%) patients, respectively. Cisplatin, administered to patients with gastric cancer, did not induce peripheral neuropathy. The aforementioned indicated that GSTP1 genetic polymorphism is associated with peripheral neuropathy induced by oxaliplatin treatment for colorectal cancer, and therefore serves as a predictive marker. Furthermore, early dose reduction or drug withdrawal should be implemented depending on the severity of peripheral neuropathy as a potential method for reducing the number of patients discontinuing the drug, due to adverse events involving peripheral neuropathy.

Radiogenomic Analysis of F-18-Fluorodeoxyglucose Positron Emission Tomography and Gene Expression Data Elucidates the Epidemiological Complexity of Colorectal Cancer Landscape.

PURPOSE: Transcriptomic profiling has enabled the neater genomic characterization of several cancers, among them colorectal cancer (CRC), through the derivation of genes with enhanced causal role and informative gene sets. However, the identification of small-sized gene signatures, which can serve as potential biomarkers in CRC, remains challenging, mainly due to the great genetic heterogeneity of the disease. METHODS: We developed and exploited an analytical framework for the integrative analysis of CRC datasets, encompassing transcriptomic data and positron emission tomography (PET) measurements. Profiling data comprised two microarray datasets, pertaining biopsy specimen from 30 untreated patients with primary CRC, coupled by their F-18-Fluorodeoxyglucose (FDG) PET values, using tracer kinetic analysis measurements. The computational framework incorporates algorithms for semantic processing, multivariate analysis, data mining and dimensionality reduction. RESULTS: Transcriptomic and PET data feature sets, were evaluated for their discrimination performance between primary colorectal adenocarcinomas and adjacent normal mucosa. A composite signature was derived, pertaining 12 features: 7 genes and 5 PET variables. This compact signature manifests superior performance in classification accuracy, through the integration of gene expression and PET data. CONCLUSIONS: This work represents an effort for the integrative, multilayered, signature-oriented analysis of CRC, in the context of radio-genomics, inferring a composite signature with promising results for patient stratification.

Inhibition of glutathione S-transferase-pi triggers c-jun N-terminal kinase-dependent neuronal death in Zn-induced Parkinsonism.

Oxidative stress is recognized as one of the major wrongdoers in Parkinson's disease (PD) while glutathione S-transferase (GST), an endogenous antioxidant, protects from oxidative stress-induced neurodegeneration. Despite GST-pi (GST-π) encounters the toxic manifestations in PD, its role in zinc (Zn)-induced nigrostriatal dopaminergic neurodegeneration remains elusive. The study aimed to explore the role of GST-π in Zn-induced Parkinsonism and its underlying molecular mechanism. Male Wistar rats were treated intraperitoneally with zinc (zinc sulfate), twice a week, for 2-12 weeks. GST-π inducer, benzyl isothiocyanate (BITC) was also administered in a few sets of experiments along with respective vehicle. Catalytic activity and expression of GST-π protein, total GST activity, neurobehavioral indexes, striatal dopamine and its metabolites, nigral tyrosine hydroxylase (TH)-positive neurons and expression of TH and B-cell lymphoma-2 (Bcl-2) proteins were reduced in Zn-treated rats. Conversely, oxidative stress indicators, c-jun N-terminal kinase (JNK) activation, c-jun phosphorylation, cytochrome c release, Bcl-2-associated X protein (Bax) translocation, and procaspase 3/9 to caspase 3/9 conversion were significantly increased in Zn-exposed rats. BITC ameliorated GST-π activity/expression and normalized Zn-induced changes in neurodegenerative indicators, oxidative stress, JNK activation, c-jun phosphorylation and apoptotic indexes. The results demonstrate that Zn inhibits GST-π expression leading to increased oxidative stress and JNK activation, which induce apoptosis thereby degeneration of the nigrostriatal dopaminergic neurons.

Glutathione S-transferase π: a potential role in antitumor therapy.

Glutathione S-transferase π (GSTπ) is a Phase II metabolic enzyme that is an important facilitator of cellular detoxification. Traditional dogma asserts that GSTπ functions to catalyze glutathione (GSH)-substrate conjunction to preserve the macromolecule upon exposure to oxidative stress, thus defending cells against various toxic compounds. Over the past 20 years, abnormal GSTπ expression has been linked to the occurrence of tumor resistance to chemotherapy drugs, demonstrating that this enzyme possesses functions beyond metabolism. This revelation reveals exciting possibilities in the realm of drug discovery, as GSTπ inhibitors and its prodrugs offer a feasible strategy in designing anticancer drugs with the primary purpose of reversing tumor resistance. In connection with the authors' current research, we provide a review on the biological function of GSTπ and current developments in GSTπ-targeting drugs, as well as the prospects of future strategies.