OBJECTIVE: To study the effect of MDR1 (P-gp) and ABCG2 on the drug resistance in Hep 2 cells. METHOD: Flow cytometry was used to detect the variations of the antitumor drugs accumulation and discharging, and activity variations when MDR1 and ABCG2 inhibitors were used in Hep-2. RESULT: The accumulation and discharging of mitoxantrone was significantly higher than the control group when ABCG2 inhibitor FTC was used in Hep-2 (P<0. 05). In contrast, P-gp did not appear similar case; To the mitoxantrone and cisplatin, there was no statistical correlation about activity of Hep-2 between P-gp or ABCG2 antagonist and the control; To the doxorubicin, combining FTC and P-gp, the activity of Hep-2 was higher than the control and difference was significant (P<. 05), In contrast, FTC and P-gp did not appear similar case when used alone; To the 5-FU, when PGP used, the activity of Hep-2 was higher than that in the control and difference was significant (P<0. 05), In con- trast, FTC and FTC+P-gp did not appear similar case; To the paclitaxel, when P-gp or FTC+P-gp used, the activity of Hep-2 was higher than that in the control and difference was significant(P<0. 05). CONCLUSION ABCG2 may lead to drug resistance mainly by changing the ability of cell in accumulating and discharging chemotherapy drugs. P-gp has other way. P-gp and ABCG2 play different roles in different drug resistance.
ATP Binding Cassette Transporter, Subfamily B ; metabolism ; ATP Binding Cassette Transporter, Subfamily G, Member 2 ; ATP-Binding Cassette Transporters ; metabolism ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; Mitoxantrone ; pharmacology ; Neoplasm Proteins ; metabolism ; Paclitaxel ; pharmacology

Laportea bulbifera extract is effective in resisting inflammation and shows a good therapeutic effect on rheumatoid arthritis in rats. However, the absorption characteristics of active components in L. bulbifera extract in Caco-2 cells are still unclear, which limits the in-depth development of L. bulbifera resources. The purpose of this study was to investigate the absorption and transport mechanism of the active components of L. bulbifera extract in the Caco-2 cell model and explore the effects of different factors(concentration, time, pH value, temperature, and efflux transporter inhibitor) on its uptake and transport. The results showed that L. bulbifera extract at the concentration of 2.0-8.0 mg·mL~(-1) showed no toxicity to Caco-2 cells. The uptake and transport of L. bulbifera extract in the Caco-2 cell model were concentration-dependent and time-dependent. The main absorption mechanism was passive diffusion, and acidic condition(pH 5.0-6.0) and 37 ℃ were more favorable for drug absorption. P_(app)>1.0×10~(-6 )cm·s~(-1) of each component indicated that L. bulbifera was a moderately absorbed drug. P-gp, MRP2, and BCRP were not involved in its uptake and transport.
Humans ; Rats ; Animals ; Caco-2 Cells ; ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics* ; Intestinal Absorption ; Neoplasm Proteins/metabolism* ; Urticaceae ; Biological Transport ; Plant Extracts/pharmacology*

OBJECTIVE: To establish cytarabine-resistant acute lymphoblastic leukemia (ALL) cell lines and investigate its possible resistant mechanism. METHODS: Low-concentration cytarabine (Ara-C) continuously induced and cultured Jurkat and Nalm-6 cells to construct cytarabine-resistant cell lines Jurkat/Ara-C and Nalm-6/Ara-C. The cell viability was detected by CCK-8 assay, and the distribution of cell cycle was detected by flow cytometry. Real-time fluorescence quantitative PCR was used to detect the mRNA expression levels of multidrug resistant gene and Ara-C metabolic enzymes. The expression levels of cyclin were detected by Western blot. RESULTS: Jurkat/Ara-C and Nalm-6/Ara-C drug-resistant cell lines were successfully established, the resistance index of which was 1 973.908±161.163 and 7 231.643± 1 190.624, respectively. Drug-resistant cell lines had no cross-resistance to commonly used chemotherapeutic drugs, such as doxorubicin. Flow cytometry showed that the ratio of G CONCLUSION Cytarabine-resistant ALL cell lines are successfully established by using low concentration continuous induction method, and its drug-resistant mechanism may be related to the deficiencies of DCK and cyclinB1.
ATP Binding Cassette Transporter, Subfamily G, Member 2 ; Cell Line ; Cytarabine/pharmacology* ; Drug Resistance, Neoplasm ; Humans ; Neoplasm Proteins ; Precursor Cell Lymphoblastic Leukemia-Lymphoma

Drug metabolism will change significantly during inflammation, including the reduction of expression and activity of many drug metabolizing enzymes and transporters. Body would release a series of inflammatory cytokines which can regulate drug metabolizing enzymes. Recent studies have revealed that drug transporters are also regulated by the cytokines with obvious species difference. Mechanism studies show that several transcription factors play important roles during the signal pathways of regulation. This review focuses on the progress in the regulation of drug transporters during inflammation.
ATP Binding Cassette Subfamily B Member 11 ; ATP Binding Cassette Transporter, Sub-Family B ; metabolism ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; metabolism ; Animals ; Biological Transport ; Humans ; Inflammation ; metabolism ; Membrane Transport Proteins ; metabolism ; Multidrug Resistance-Associated Proteins ; metabolism ; Neoplasm Proteins ; metabolism ; Organic Anion Transporters ; metabolism ; Organic Cation Transport Proteins ; metabolism ; Signal Transduction

OBJECTIVE: To construct three short hairpin RNA (shRNA) interference expression plasmid vectors of human ABCG2 gene, to assay the expression of ABCG2 in a human nasopharyngeal carcinoma (NPC) cell line, CEN-2 cell line, and to detect the RNAi effect of shRNA. METHOD: Targeting ABCG2 gene sequence, three plasmid expression vectors coding for shRNA and a control vector containing random DNA fragment were constructed. The recombinant plasmids were amplified in Ecoli. DH5 and then identified by restriction digestion, PCR and sequencing. The recombinant plasmids were transfected into CEN-2 cells. ABCG2 expression was assayed by real-time quantitative PCR and Western blot. RESULT: The construction of pGC-silencer-U6/Neo/GFP/ABCG2 was succeed. The shRNA plasmids significantly down-regulated the ABCG2 expression in CEN-2 cells, at both mRNA level and protein level. Recombinant plasmid 1 had the strongest effect compared with plasmids 2 and 3 (P < 0.05), with an inhibition ratio of 75% at the mRNA level and 68% at the protein level. CONCLUSION pGC-silencer-U6/Neo/GFP/ABCG2 has been successfully constructed and it can down-regulate ABCG2 expression after transfected into CEN-2 cells, which could help further studies of ABCG2 functions CEN-2 cell line and contribute to the NPC gene therapy.
ATP Binding Cassette Transporter, Subfamily G, Member 2 ; ATP-Binding Cassette Transporters ; genetics ; Cell Line, Tumor ; Gene Expression ; Genetic Vectors ; Humans ; Nasopharyngeal Neoplasms ; genetics ; Neoplasm Proteins ; genetics ; Plasmids ; RNA Interference ; RNA, Messenger ; genetics ; RNA, Small Interfering ; Transfection

ABCG2 is a half ATP-binding cassette (ABC) transporter that facilitates efflux of a wide variety of substrates ranging from natural products to synthetic anticancer drugs. Over-expression of ABCG2 has been shown to cause multidrug resistance in both laboratory model cell lines and in clinical settings. The polymorphism in ABCG2 has also been suggested to affect the function and clinical outcome in cancer patients. More recently, ABCG2 has been suggested to play a protective role for cancer and normal stem cells. Thus, ABCG2 is an ideal target for therapeutic development to chemo-sensitize drug resistant cancers. In this paper, the recent progress on understanding the structure, function, and pharmacology of ABCG2 and its role in drug resistance and cancer stem cells will be reviewed.
ATP Binding Cassette Transporter, Subfamily G, Member 2 ; ATP-Binding Cassette Transporters ; chemistry ; genetics ; pharmacology ; Drug Resistance, Multiple ; Genes, MDR ; Humans ; Neoplasm Proteins ; chemistry ; genetics ; pharmacology ; Neoplastic Stem Cells ; metabolism ; Polymorphism, Genetic

ATP Binding Cassette Subfamily B Member 11 ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; physiology ; ATP-Binding Cassette, Sub-Family B, Member 1 ; physiology ; Animals ; Bile ; metabolism ; Biliary Tract ; physiology ; Drug Interactions ; Drug Resistance, Multiple ; Humans ; Liver ; physiology ; Multidrug Resistance-Associated Proteins ; physiology ; Neoplasm Proteins ; physiology ; Organic Anion Transporters ; physiology ; Organic Anion Transporters, Sodium-Dependent ; physiology ; Organic Cation Transport Proteins ; physiology ; Symporters ; physiology

OBJECTIVE: To investigate the biological characteristics of ABCG2 and its effect on side population cells (SP cells) of multiple myeloma (MM) so as to find the way for reversing drug resistance. METHODS: The silence of ABCG2 expression was performed throngh interfering the MM cells by using siRNA. then the ratio of SP cell of MM, speed of cell proliferation and sensitivity of cells to chermotherapentic drugs before and after interference were compared, the biological functions of ABCG2 and its role in regulation of SP cells and PTEN/PI3K/AKT signaling pathway was clarified. RESULTS: siRNA interference could down regulate the expression of ABCG2 at both mRNA and protein level. After siRNA interference, the proliferation of multiple myeloma cells was decreased slightly, the expression of PTEN was increased, the activity of PI3K/AKT pathway was inhibited, and the ratio of SP cells was decreased. CONCLUSION In multiple myeloma, down-regulation of expression ABCG2 can negatively regulate the expression of PTEN, the PI3K/AKT signaling pathway is inhibited,the ratio of SP decreased,and the response to drug is increased.
ATP Binding Cassette Transporter, Subfamily G, Member 2 ; Cell Line, Tumor ; Humans ; Multiple Myeloma ; Neoplasm Proteins ; PTEN Phosphohydrolase ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt ; Side-Population Cells ; Signal Transduction

Mutations in the epithelial growth factor receptor (EGFR) is a driving factor that causes non-small cell lung carcinoma (NSCLC). The epithelial growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is a crucial discovery in the treatment of lung cancer, particularly the efficacy of EGFR-TKIs is superior to that of the standard chemotherapy for patients with EGFR mutation-positive advanced NSCLC. Patients with NSCLC use EGFR-TKIs and other medications simultaneously is commonly seen, especially among those with comorbidities, which increases the risk of drug-drug interactions (DDIs) of EGFR-TKIs. The most common mechanisms underlying the DDIs of EGFR-TKIs are modulations of cytochrome P450 (CYP) and drug transporters [including P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP)], as well as gastrointestinal acid-inhibitory drugs [proton pump inhibitors (PPIs) and H(2) receptor antagonists (H(2)RA)]. Inhibitors or inducers of CYP enzymes and drug transporters can inhibit or accelerate the metabolism of EGFR-TKIs, which increase or reduce the exposure of EGFR-TKIs, thereby affect the efficacy and safety of EGFR-TKIs. In addition, PPIs or H(2)RA can decrease the solubility, bioavailability and efficacy of EGFR-TKIs. This review summarizes the mechanisms of DDIs of gefitinib, erlotinib, icotinib, afatinib, dacomitinib and osimertinib; the management recommendations for DDIs of those EGFR-TKIs from the Chinese and global guideline, as well as from the recent pre-clinical and clinical studies, which provide the reference and evidence for managing the combination therapies of EGFR-TKIs and other medications in clinics.
ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics* ; Carcinoma, Non-Small-Cell Lung/pathology* ; Drug Interactions ; ErbB Receptors/genetics* ; Humans ; Lung Neoplasms/pathology* ; Mutation ; Neoplasm Proteins/metabolism* ; Protein Kinase Inhibitors/adverse effects*

OBJECTIVE: To analyze the correlation between the mRNA levels of breast cancer resistance protein (BCRP) and lung-specific X protein (LUNX) genes with pathological types and stages of patients with non-small cell lung cancer (NSCLC) and their significance for prognosis. METHODS: Eighty nine patients with NSCLC admitted to Huaihe Hospital of Henan University between June 2015 and June 2018 were recruited, with 55 patients with benign lung lesions admitted during the same period of time selected as the control group. The mRNA levels of BCRP and LUNX genes were detected in the peripheral blood samples from the two groups, and their correlation with the clinicopathological characteristics and prognosis of the patients was analyzed. RESULTS: The expression rates of BCRP and LUNX mRNA in the NSCLC group were significantly higher compared with the control group (P < 0.05). The level of BCRP mRNA of the NSCLC patients has correlated with the degree of differentiation and TNM staging (P < 0.05), but not with gender, age, smoking, pathological types and lymph node metastasis (P > 0.05). The level of LUNX mRNA of them has correlated with the degree of differentiation, TNM staging and lymph node metastasis (P < 0.05), but not with gender, age, smoking, and pathological types (P > 0.05). Compared with those with no expression, the overall survival rate of patients with BCRP and LUNX expression was significantly lower (P < 0.05). The degree of differentiation, TNM staging, lymph node metastasis, and expression of the BCRP and LUNX mRNA may all affect the prognosis of the patients. CONCLUSION The levels of BCRP and LUNX mRNA in the peripheral blood of patients with NSCLC are significantly increased. The expression of BCRP mRNA is correlated with the degree of differentiation and TNM staging, whilst the expression of LUNX mRNA is correlated with the differentiation degree, TNM staging and lymph node metastasis. Both may be used as independent predictors for the prognosis of patients with NSCLC.
Humans ; ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics* ; Biomarkers, Tumor/genetics* ; Carcinoma, Non-Small-Cell Lung/pathology* ; Glycoproteins/genetics* ; Lung Neoplasms/pathology* ; Lymphatic Metastasis ; Neoplasm Proteins/genetics* ; Phosphoproteins/genetics* ; Prognosis ; RNA, Messenger/genetics*