Research progress of the regulation of orphan nuclear receptors on chronic liver diseases / 生理学报

The development of chronic liver disease can be promoted by excessive fat accumulation, dysbiosis, viral infections and persistent inflammatory responses, which can lead to liver inflammation, fibrosis and carcinogenesis. An in-depth understanding of the etiology leading to chronic liver disease and the underlying mechanisms influencing its development can help identify potential therapeutic targets for targeted treatment. Orphan nuclear receptors (ONRs) are receptors that have no corresponding endogenous ligands to bind to them. The study of these ONRs and their biological properties has facilitated the development of synthetic ligands, which are important for investigating the effective targets for the treatment of a wide range of diseases. In recent years, it has been found that ONRs are essential for maintaining normal liver function and their dysfunction can affect a variety of liver diseases. ONRs can influence pathophysiological activities such as liver lipid metabolism, inflammatory response and cancer cell proliferation by regulating hormones/transcription factors and affecting the biological clock, oxidative stress, etc. This review focuses on the regulation of ONRs, mainly including retinoid related orphan nuclear receptors (RORs), pregnane X receptor (PXR), leukocyte cell derived chemotaxin 2 (LECT2), Nur77, and hepatocyte nuclear factor 4α (HNF4α), on the development of different types of chronic liver diseases in different ways, in order to provide useful references for the therapeutic strategies of chronic liver diseases based on the regulation of ONRs.

Role of Androgen Receptor in Prostate Cancer: A Review

Androgen receptor (AR) is a steroid receptor transcriptional factor for testosterone and dihydrotestosterone consisting of four main domains, the N-terminal domain, DNA-binding domain, hinge region, and ligand-binding domain. AR plays pivotal roles in prostate cancer, especially castration-resistant prostate cancer (CRPC). Androgen deprivation therapy can suppress hormone-naïve prostate cancer, but prostate cancer changes AR and adapts to survive under castration levels of androgen. These mechanisms include AR point mutations, AR overexpression, changes of androgen biosynthesis, constitutively active AR splice variants without ligand binding, and changes of androgen cofactors. Studies of AR in CRPC revealed that AR was still active in CRPC, and it remains as a potential target to treat CRPC. Enzalutamide is a second-generation antiandrogen effective in patients with CRPC before and after taxane-based chemotherapy. However, CRPC is still incurable and can develop drug resistance. Understanding the mechanisms of this resistance can enable new-generation therapies for CRPC. Several promising new AR-targeted therapies have been developed. Apalutamide is a new Food and Drug Administration-approved androgen agonist binding to the ligand-binding domain, and clinical trials of other new AR-targeted agents binding to the ligand-binding domain or N-terminal domain are underway. This review focuses on the functions of AR in prostate cancer and the development of CRPC and promising new agents against CRPC.

Potential Role for a Panel of Immunohistochemical Markers in the Management of Endometrial Carcinoma

BACKGROUND: In order to improve the efficacy of endometrial carcinoma (EC) treatment, identifying prognostic factors for high risk patients is a high research priority. This study aimed to assess the relationships among the expression of estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptor 2 (HER2), Ki-67, and the different histopathological prognostic parameters in EC and to assess the value of these in the management of EC. METHODS: We examined 109 cases of EC. Immunohistochemistry for ER, PR, HER2, and Ki-67 were evaluated in relation to age, tumor size, International Federation of Gynecology and Obstetrics (FIGO) stage and grade, depth of infiltration, cervical and ovarian involvement, lymphovascular space invasion (LVSI), and lymph node (LN) metastasis. RESULTS: The mean age of patients in this study was 59.8 ± 8.2 years. Low ER and PR expression scores and high Ki-67 expression showed highly significant associations with non-endometrioid histology (p = .007, p < .001, and p < .001, respectively) and poor differentiation (p = .007, p < .001, and p <. 001, respectively). Low PR score showed a significant association with advanced stage (p = .009). Low ER score was highly associated with LVSI (p = .006), and low PR scores were associated significantly with LN metastasis (p = .026). HER2 expression was significantly related to advanced stages (p = .04), increased depth of infiltration (p = .02), LVSI (p = .017), ovarian involvement (p = .038), and LN metastasis (p = .038). There was a close relationship between HER2 expression and uterine cervical involvement (p = .009). Higher Ki-67 values were associated with LN involvement (p = .012). CONCLUSIONS: The over-expression of HER2 and Ki-67 and low expression of ER and PR indicate a more malignant EC behavior. An immunohistochemical panel for the identification of high risk tumors can contribute significantly to prognostic assessments.

Characteristic Changes in Decidual Gene Expression Signature in Spontaneous Term Parturition

BACKGROUND: The decidua has been implicated in the “terminal pathway” of human term parturition, which is characterized by the activation of pro-inflammatory pathways in gestational tissues. However, the transcriptomic changes in the decidua leading to terminal pathway activation have not been systematically explored. This study aimed to compare the decidual expression of developmental signaling and inflammation-related genes before and after spontaneous term labor in order to reveal their involvement in this process. METHODS: Chorioamniotic membranes were obtained from normal pregnant women who delivered at term with spontaneous labor (TIL, n = 14) or without labor (TNL, n = 15). Decidual cells were isolated from snap-frozen chorioamniotic membranes with laser microdissection. The expression of 46 genes involved in decidual development, sex steroid and prostaglandin signaling, as well as pro- and anti-inflammatory pathways, was analyzed using high-throughput quantitative real-time polymerase chain reaction (qRT-PCR). Chorioamniotic membrane sections were immunostained and then semi-quantified for five proteins, and immunoassays for three chemokines were performed on maternal plasma samples. RESULTS: The genes with the highest expression in the decidua at term gestation included insulin-like growth factor-binding protein 1 (IGFBP1), galectin-1 (LGALS1), and progestogen-associated endometrial protein (PAEP); the expression of estrogen receptor 1 (ESR1), homeobox A11 (HOXA11), interleukin 1β (IL1B), IL8, progesterone receptor membrane component 2 (PGRMC2), and prostaglandin E synthase (PTGES) was higher in TIL than in TNL cases; the expression of chemokine C-C motif ligand 2 (CCL2), CCL5, LGALS1, LGALS3, and PAEP was lower in TIL than in TNL cases; immunostaining confirmed qRT-PCR data for IL-8, CCL2, galectin-1, galectin-3, and PAEP; and no correlations between the decidual gene expression and the maternal plasma protein concentrations of CCL2, CCL5, and IL-8 were found. CONCLUSIONS: Our data suggests that with the initiation of parturition, the decidual expression of anti-inflammatory mediators decreases, while the expression of pro-inflammatory mediators and steroid receptors increases. This shift may affect downstream signaling pathways that can lead to parturition.

In silico investigation of agonist activity of a structurally diverse set of drugs to hPXR using HM-BSM and HM-PNN / 华中科技大学学报（医学）（英德文版）

The human pregnane X receptor (hPXR) plays a critical role in the metabolism, transport and clearance of xenobiotics in the liver and intestine. The hPXR can be activated by a structurally diverse of drugs to initiate clinically relevant drug-drug interactions. In this article, in silico investigation was performed on a structurally diverse set of drugs to identify critical structural features greatly related to their agonist activity towards hPXR. Heuristic method (HM)-Best Subset Modeling (BSM) and HM-Polynomial Neural Networks (PNN) were utilized to develop the linear and non-linear quantitative structure-activity relationship models. The applicability domain (AD) of the models was assessed by Williams plot. Statistically reliable models with good predictive power and explain were achieved (for HM-BSM, r (2)=0.881, q LOO (2) =0.797, q EXT (2) =0.674; for HM-PNN, r (2)=0.882, q LOO (2) =0.856, q EXT (2) =0.655). The developed models indicated that molecular aromatic and electric property, molecular weight and complexity may govern agonist activity of a structurally diverse set of drugs to hPXR.

Effect of polymorphisms of NF-κB and PXR on platinum-based chemotherapy for non-small cell lung cancer / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of polymorphisms of NF-κB rs230521, NF-κB rs4648068 and pregnane X receptor (PXR) rs3814058 on platinum-based chemotherapy for non-small cell lung cancer patients. 
@*METHODS@#We collected 262 cases of non-small cell lung cancer patients, and then analyzed the genotypes of NF-κB and PXR by MassARRAY method. The impact of polymorphisms on efficacy, gastrointestinal toxicity and hematological toxicity was analyzed by logistic regression.
@*RESULTS@#Compared to patients with GG genotype, patients with NF-κB rs230521 CC genotype had the higher risk to suffer hematological toxicity (OR=3.485, P=0.011). Patients with PXR rs3814058 CC and CT genotype exhibited higher possibility to suffer hematological toxicity than those with TT (OR=2.045, P=0.048). Polymorphism of NF-κB rs4648068 did not show significant effect on chemotherapy efficacy and occurrence of gastrointestinal toxicity and hematological toxicity.
@*CONCLUSION@#Patients with NF-κB rs230521 CC, PXR rs3814058 CC and CT had higher risk to suffer hematological toxicity during platinum-based chemotherapy for non-small cell lung cancer. A rational dosage and course of treatment should be chosen to protect the patients with high risk genotype suffering hematological toxicity during their platinum-based therapy.

Effects of Garcinia Acid Combined with Daunorubicin on Expression of Pregnane X Receptor in Leukemia Cell Line K562/A02 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the expression of PXR (Pregnane X receptor) in several malignant hematological cell lines, and to investigate the reversal effect of Gambogic acid (GA) on multi-drug resistance (MDR) of K562/A02 cell line and its reversal mechanism.</p><p><b>METHODS</b>Transcription of PXR was detected by real-time PCR in several malignant hematological cell lines. The growth inhibition rate of K562/A02 in different experimental groups was assayed by MTT method, and the expression of PXR protein was measured by Western blot.</p><p><b>RESULTS</b>PXR gene transcription could be detected in several hematological malignancy cell lines, and it was significantly higher in K562/A02 cell line, compared with the other cell lines used in this experiment. Low-dose GA could enhance cell growth inhibition rate, increasing the effect of chemotherapy, which may be associated with down-regulation of PXR expression. PXR gene transcription and protein expression in GA and DNR+GA groups decreased as compared with control group and the DNR group, suggesting that low-dose GA can down-regulate PXR gene transcription and protein expression.</p><p><b>CONCLUSION</b>PXR gene transcription can be detected in several hematological malignancy cell line, which is significantly higher in K562/A02 cell line, as compared with the other cell lines used in this experiment. Low-dose GA can enhance cell growth inhibition rate, increasing the effect of chemotherapy, which may be associated with down-regulation of PXR expression.</p>

Pharmacology research on PXR as a potential target in screening bioactive components of Chinese material medica / 中国中药杂志

Pregnane X receptor (PXR) is key transcription factors which mainly regulate the expression of CYP3A genes. At the molecular level, PXR has been revealed the protection mechanism of the body against xenochemicals and a major mode of the drug-drug interactions. Besides playing an important role in drug metabolism and interactions, PXR and its target genes also play an important role in maintaining normal physiological function and homeostasis. Therefore, it is necessary to study the regulation of PXR and its related pharmacological effects of TCM and natural products, and to provide new clues for the new pharmacological pathway.

The role of arecoline on hepatic insulin resistance in type 2 diabetes rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the effects of arecoline on hepatic insulin resistance in type 2 diabetes rats and to elucidate its possible mechanism.</p><p><b>METHODS</b>Forty five Wistar rats were fed with high fructose diet for 12 weeks to induce type 2 diabetic rat model. rats were randomly divided into 5 groups (n = 8): control group, model group and model group were treated with different dose (0, 0.5, 1, 5 mg/kg) of arecoline. After 4 weeks, the fasting blood glucose, blood lipid and insulin level measured , mRNA expression of liver constitutive androstane receptor (CAR), pregnane X receptor (PXR), glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were detected by reverse transcription polymerase chain reaction (RT-PCR), the protein expression of p-AKT and glucose transporter4 (GLUT4) were detected by Western blot.</p><p><b>RESULTS</b>1.5 mg/kg arecoline could significantly decrease the level of fasting blood glucose, blood lipid, blood insulin level and liver G6Pase, PEPCK, IL-6, TNF-alpha mRNA level in type 2 diabetes rats. 1.5 mg/kg arecoline also could significantly increase CAR, PXR mRNA level and p-AKT and GLUT4 protein expression.</p><p><b>CONCLUSION</b>Arecoline improved hepatic insulin resistance in type 2 diabetes rats by increasing the mRNA levels of CAR and PXR leading to the creased glucose metabolism and inflammation related genes expression.</p>

Screening active components in compound danshen based on PXR-CYP3A4: an experimental study / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To screen active components in Compound Danshen (CD) based on pregnane X receptor-cytochrome P450 3A4 (PXR-CYP3A4).</p><p><b>METHODS</b>By using PXR-CYP3A stable transfection human hepatoblastoma G2 (HepG2) cell lines engineering cell strain combined reporter genes technology, active components that induce or inhibit PXR-CYP3A4 paths in CD were screened, and confirmed at the level of enzymic activities. The experiment was divided into the positive control group (RIF 10 micro mol/L), the DMSO group (DMSO 0.1%), each dose of treatment groups (ginsenoside Rc, Rf, Rb2, Rg2, F2, F1, tanshinone I , isoborneol 5, 10, 25, 50, 100, and 200 micro mol/L; each with six duplicates). Cells medium was removed 36, 48, and 60 h after treatment. The activity of CYP3A4 was then determined in the supernant and the fold induction was calculated.</p><p><b>RESULTS</b>Compared with the DMSO group, the fold induction increased when ginsenoside Rc, Rf, Rb2, Rg2, F2, F1, tanshinone I , and isoborneol 50 and 100 micro mol/L was respectively intervened for 36, 48, and 60 h (P <0.05). When cells were treated with isoborneol 200 micro mol/L for 48 and 60 h,the fold induction of ginsenoside Rb2, Rg2, and F1 was significantly higher than that of the RIF group (P <0.05). Enzymic activity results showed that ginsenoside Rc, Rf, Rb2, F2, and F1 could increase the enzyme activity of CYP3A4 at 48 h (P <0.05).</p><p><b>CONCLUSION</b>Ginsenoside Rc, Rf, Rb2, F2, F1, tanshinone I, and isoborneol in DC could induce CYP3A4 enzymes.</p>

Influence of PPARA, RXRA, NR1I2 and NR1I3 gene polymorphisms on the lipid-lowering efficacy and safety of statin therapy / Influência de polimorfismos nos genes PPARA, RXRA, NR1I2 e NR1I3 na eficácia hipolipemiante e na segurança da terapia com estatinas

OBJECTIVE: The aim of the present study was investigate the association between six genetic variants in the nuclear receptor genes PPARA, RXRA, NR1I2 and NR1I3 and the lipid-lowering efficacy and safety of statin therapy. SUBJECTS AND METHODS: The study was carried out on 240 Brazilian hypercholesterolemic patients on simvastatin and atorvastatin therapy. The polymorphisms were analyzed by PCR-based methods. RESULTS: The NR1I3 rs2307424 genotype distribution was different between subjects with and without adverse drug reactions. Among subjects in the ADR group, no T/T homozygotes were observed for this polymorphism, while in the non-ADR group the frequency of this genotype was 19.4% (P = 0.007, after multiple testing corrections P = 0.042). CONCLUSION: The polymorphisms investigated in PPARA (rs1800206), RXRA (rs11381416), and NR1I2 (rs1523130) did not influence the lipid-lowering efficacy and safety of statin. Our results show the possible influence of NR1I3 genetic variant on the safety of statin.

OBJETIVO: O objetivo deste estudo foi investigar a associação de seis variantes genéticas nos genes de receptores nucleares PPARA, RXRA, NR1I2 e NR1I3 na eficácia hipolipemiante e na segurança da terapia com estatinas. SUJEITOS E MÉTODOS: O estudo foi realizado com 240 pacientes hipercolesterolêmicos em terapia com sinvastina e atorvastatina. Os polimorfismos foram analisados por meio de métodos baseados em PCR. RESULTADOS: A distribuição da frequência genotípica do polimorfismo NR1I3 rs2307424 foi diferente entre os pacientes com e sem efeito adverso à medicação; entre os sujeitos do grupo com efeitos adversos, nenhum homozigoto T/T foi observado, enquanto no grupo de indivíduos sem efeitos adversos a frequência desse genótipo foi 19,4% (P = 0,007, após correção para múltiplos testes P = 0,042). CONCLUSÃO: Os polimorfismos investigados nos genes PPARA (rs1800206), RXRA (rs11381416) e NR1I2 (rs1523130) não foram associados com eficácia hipolipemiante e segurança da terapia com estatinas. Nossos resultados mostram uma possível influência de variantes do gene NR1I3 (rs2307424) no desenvolvimento de efeitos adversos à terapia com estatinas.

Study on effect of Curculiginis Rhizoma and its active ingredient on PXR-CYP3A of L02 cells in different states / 中国中药杂志

<p><b>OBJECTIVE</b>To define the effect of Curculiginis Rhizoma and its active ingredient orcinol glucoside on PXR-CYP3A of L02 cells in normal and deficiency-cold states, in order to lay a foundation for studies on the mechanism of efficacy expression differentiation of Curculiginis Rhizoma in different states.</p><p><b>METHOD</b>Serums of normal and deficiency-cold rats were adopted to culture L02 cells and induce cells in normal and deficiency-cold states. After aqueous extracts from Curculiginis Rhizoma and its active ingredient orcinol glucoside were used in cells in different states, PXR protain expression and CYP3A activity of L02 cells in normal and deficiency-cold states were observed.</p><p><b>RESULT</b>MTT results showed that aqueous extracts from Curculiginis Rhizoma and orcinol glucoside could significantly enhance viability of L02 cells. Aqueous extracts from Curculiginis Rhizoma could significantly reduce PXR protein expression of L02 cells in normal state, while orcinol glucoside could significantly reduce CYP3A activity and PXR protein expression of L02 cells in normal state. Meanwhile, aqueous extracts from Curculiginis Rhizoma could significantly increase CYP3A activity and PXR protein expression of L02 cells in deficiency-cold state, while orcinol glucoside could significantly reduce CYP3A activity and increase PXR protein expression of L02 cells in deficiency-cold state.</p><p><b>CONCLUSION</b>Curculiginis Rhizoma can activate PXR and induce CYP3A activity of L02 cells in deficiency-cold state, but with no effect or even counteraction on PXR and its induced CYP3A of L02 cells in normal state.</p>

Survival of women with ovarian carcinomas and borderline tumors is not affected by estrogen and progesterone receptor status / 부인종양

OBJECTIVE: To examine the patterns of estrogen receptor (ER) and progesterone receptor (PR) expression in borderline ovarian tumors (BOTs) and ovarian carcinomas. We also assessed the disease-free survival (DFS) and overall survival (OS) in women with ovarian carcinoma, in relation to ER and/or PR expression. METHODS: We examined ER/PR expression in 38 BOTs and 172 ovarian carcinomas removed from patients treated at the State University of Campinas-UNICAMP (Brazil), from 1993 to 2008 and followed for up to 60 months using tissue microarray-based immunohistochemistry. RESULTS: Twenty-eight (73.7%) mucinous and 10 (26.3%) serous BOTs were included. Ovarian carcinomas consisted mainly of 79 (46.0%) serous, 44 (25.5%) mucinous, 17 (9.8%) endometrioid, 10 (5.8%) clear-cell types. There was no significant difference of the ER/PR expression between BOT and ovarian carcinoma (p=0.55 for ER alone, 0.90 for PR alone, and 0.12 for combined expression). The level of ER/PR expression in BOTs was significantly higher in serous than in mucinous tumors (p<0.01). In carcinomas, ER/PR was higher in serous tumors than in mucinous (p<0.01) and clear cell tumors (p=0.02), and higher in endometrioid tumors than in mucinous tumors (p<0.01). DFS was affected neither by the clinical characteristics nor by combined steroid receptor status. OS was found to be significantly worse (p<0.01) only in women with stages II-IV tumors and those with residual disease after surgery (p<0.01). CONCLUSION: Overall, serous and endometrioid tumors were predominantly ER/PR positive, whereas mucinous and clear-cell tumors were preponderantly ER/PR negative. DFS and OS were not affected by ER/PR expression.

Reversing effects of silybin on TAA-induced hepatic CYP3A dysfunction through PXR regulation / 中国天然药物

AIM@#Silybin (SB), a major constituent of the milk thistle, has been used to treat several liver disorders. However, liver diseases were always accompanied by CYP450 dysfunction. This study was designed to explore the relationship between the hepatoprotective effect and CYP3A regulation of SB during thioacetamide (TAA)-induced rat liver injury.@*METHODS@#Serum biochemical analysis and histopathological study were taken to evaluate the hepatoprotectinve effect of SB. α-SMA were detected by immunohistochemical analysis and cytokine release in rat liver was determined by ELISA assay. CYP3A and PXR expression were determined by RT-PCR and Western blot analysis, and CYP3A activity was based on the midazolam 4-hydroxylation reaction. Also, siRNA transfection was induced in HepG2 cells to evaluate the effect of PXR on cytotoxicity and CYP3A4 dysregulation caused by TAA.@*RESULTS@#SB showed powerful hepatoprotective effects, and anti-inflammatory and anti-fibrosis effects, and reversed the loss of CYP3A and PXR in TAA-injured rat liver, and decreased PXR translocation into the cell nucleus. PXR silencing weakened the effect of SB on cytoprotection and CYP3A regulation.@*CONCLUSIONS@#PXR was a very important factor of CYP3A regulation and might be the target of SB in TAA-induced liver disease. Also, because of the potential interactions of SB and co-administered medicines, it might be necessary to adjust the dosage in the clinical medication of liver disease.

Distribution of myofibroblast cells and microvessels around invasive ductal carcinoma of the breast and comparing with the adjacent range of their normal-to-DCIS zones

This study seeks to determine the relationships between manifestation of myofibroblast in the stroma tissue of hyperplastic pre-invasive breast lesions to invasive cancer by investigating clinicopathological data of patients, their effect on steroid receptor expression and HER2, and angiogenesis according to CD34 antigen expression. Handred cases of invasive ductal carcinoma were immunohistochemically investigated for the presence of smooth muscle actin [SMA], ER/PR, HER2, anti-CD34 antibody and microvessel count [MVC]. Patients were scored in four different zones of invasive areas: invasive cancer, DCIS, fibrocystic disease +/- ductal intraepithelial neoplasia [FCD +/- DIN], and normal tissue. There was a significant difference in stromal myofibroblast between all areas except for the stroma of DCIS and FCD +/- DIN [P < 0.001]. We observed positive significant correlations between stromal myofibroblast, HER2 expression, and the numbers of involved lymph nodes in invasive cancer, DCIS, and FCD +/- DIN [P < 0.001]. More myofibroblast were present in grade III cases, with the least frequent observed among grade I cases in the stroma of those with invasive disease, DCIS, and FCD +/- DIN [P < 0.001]. MVC was inversely related to stromal myofibroblast in invasive cancer [P < 0.001] and DCIS [P < 0.001], whereas there was a positive correlation in the stroma of FCD +/- DIN [P = 0.002] and normal areas [P = 0.054]. There was a significant difference in MVC observed in all areas except for DCIS and FCD +/- DIN [P < 0.001]. We noted significant inverse correlations between MVC, HER2 expression, and the numbers of involved lymph nodes in invasive cancer and DCIS [P < 0.001]. Most MVC were present in grade I, with the least frequent observed in grade III cases in the stroma of invasive cancer, DCIS and FCD +/- DIN [P < 0.001]. Angiogenesis can be observed before any significant myofibroblastic changes in the pre-invasive breast lesions. The elevated content of myofibroblast in stroma of tumor; probably may be a worse prognostic factor and the steps from atypical epithelial hyperplasia to DCIS and then to the invasive carcinoma do not appear to be always part of a linear progression

Establishment of in vitro evaluation model for CYP2B6 induction and its application to screen inducers among TCMs / 药学学报

This paper is to report the development of a high-throughput in vitro system to screen hPXR/CAR mediated CYP2B6 drug inducers, and the application of it into the quick determination of induction activity toward CYP2B6 by various commonly used traditional Chinese medicines (TCMs) extract. Dual reporter gene assays were performed. The hPXR/CAR expression vectors and the reporter vector pGL3-CYP2B6-Luc involved in the distal and proximal promoters of CYP2B6 were co-transfected into HepG2 cells. Relative luciferase activities in cell lysate were analyzed after 48 h treatment of blank vehicle or drugs to determine the induction activity toward CYP2B6 by various commonly used TCMs extract. The positive hPXR/hCAR activators rifampicin and CITCO were applied to make sure that the reporter gene model was successfully established. Then 5 kinds of commonly used TCM extracts and 1 herbal compound were successfully investigated, some were found to activate hPXR or hCAR and therefore have the potential to induce CYP2B6 enzyme. This is the first domestic article to report the hCAR3-mediated CYP2B6 induction model and the establishment of a reporter gene system for hPXR/CAR-mediated CYP2B6 induction can be an effective and systemic in vitro method to investigate the drug inducers of CYP2B6 and to explain the mechanism involved.

Screening of pregnane X receptor activation from ginsenosides / 药学学报

In order to study effects of ginseng on the metabolism of drug belong to CYP3A4 substrate, screening of pregnane X receptor activation from ginsenosides was performed by reporter assay. Based on PXR-CYP3A stable translation cell lines, 13 ginsenosides were screened for pregnane X receptor activation by reporter assays, and RIF as the positive control. The effect of ginsenosides Rg1 onCYP3A4 mRNA expression was also investigated by RT-PCR. The PXR-CYP3A stable translation cell lines had good response to RIF, and the EC50 is 2.51 micro mol x L(-1). When the condition of final concentration was 10 micromol x L(-1), ginsenoside F2 and protopanaxatriol had moderate inductive effects on PXR. Panaxotriol, Rg2, pseudoginsenoside F11, Rg1, ginsenoside and Rb3 had inhibitory effects on PXR. Ginsenoside Rf1, Rg3, Rh2 and protopanaxdiol had no obvious effects on PXR. Rg1 down-regulated CYP3A4 mRNA expression in a concentration-dependent manner. Activation of pregnane X receptor by ginsenosides may influence the metabolism of drug belong to CYP3A4 substrate, and cause ginseng-drug interactions.

Expression of androgen receptor in breast cancer & its correlation with other steroid receptors & growth factors.

Background & objectives: Breast cancer is the second most common malignancy in Indian women. Among the members of the steroid receptor superfamily the role of estrogen and progesterone receptors (ER and PR) is well established in breast cancer in predicting the prognosis and management of therapy, however, little is known about the clinical significance of androgen receptor (AR) in breast carcinogenesis. The present study was aimed to evaluate the expression of AR in breast cancer and to elucidate its clinical significance by correlating it with clinicopathological parameters, other steroid receptors (ER and PR) and growth factors receptors (EGFR and CD105). Methods: Expression of AR, ER, PR, epidermal growth factor receptor (EGFR) and endoglin (CD105) was studied in 100 cases of breast cancer by immunohistochemistry (IHC). Risk ratio (RR) along with 95% confidence interval (CI) was estimated to assess the strength of association between the markers and clinicopathological characteristics. Categorical principal component analysis (CATPCA) was applied to obtain new sets of linearly combined expression, for their further evaluation with clinicopathological characteristics (n=100). Results: In 31 cases presenting with locally advanced breast cancer (LABC), the expression of AR, ER, PR, EGFR and CD105 was associated with response to neoadjuvant chemotherapy (NACT). The results indicated the association of AR+ (P=0.001) and AR+/EGFR- (P=0.001) with the therapeutic response to NACT in LABC patients. The AR expression exhibited maximum sensitivity, specificity and likelihood ratio of positive and negative test. The present results showed the benefit of adding AR, EGFR and CD105 to the existing panel of markers to be able to predict response to therapy. Interpretation & conclusions: More studies on the expression profiles of AR+, AR+/CD105+ and AR+/EGFR- in larger set of breast cancer patients may possibly help in confirming their predictive role for therapeutic response in LABC patients.

Effects of isorhamnetin on CYP3A4 and herb-drug interaction / 药学学报

The study is to report the investigation of the effects of isorhamnetin on CYP3A4 and herb-drug interaction. A reporter gene assay is used to test pregnane X receptor transactivation action, qRT-PCR and a luminescence-based assay were applied to determine mRNA induction and enzyme activity of CYP3A4 after isorhamnetin treatment. The interaction of irinotecan and isorhamnetin was assessed by inhibition assay of cell proliferation. Isorhamnetin at 1, 10 and 25 micromol x L(-1) transactivated the CYP3A4 reporter construct and upregulated CYP3A4 mRNA as well in a dose-dependent manner. However, isorhamnetin had no effect on enzyme activity of CYP3A4 and irinotecan HepG2 cytotoxicity. In conclusion, activation of PXR by isorhamnetin played a role in the upregulation of CYP3A4 mRNA. Moreover, joint action of isorhamnetin with other drugs may not be associated with the herb-drug interaction.

Modulation of nuclear receptors on drug-metabolizing enzymes and transporters / 药学学报

PXR, CAR and PPAR, widely distributed in the body, are important members of the nuclear receptors (NRs) family. The activities and gene expressions of drug-metabolizing enzymes (DMEs) and transporters can be regulated by the activation of NRs, which effect the drug disposition. Multidrug resistance (MDR) is the leading cause of failure in cancer therapy. NRs, including PXR, CAR and PPAR, were shown to regulate the expressions of DMEs and transporters involved in the drug metabolism and clearance, suggesting that the modulation of NRs can be considered as a new target to overcome MDR. This review described the research progress of NR family members PXR, CAR, PPAR and their transcriptional activation mechanism, the regulation of DMEs and transporters by NRs, which may provide a valuable reference for clinical medication and overcome of MDR.