<b>BACKGROUNDb>Proteasome subunits (PSMB) and transporter associated with antigen processing (TAP) loci are located in the human leukocyte antigen (HLA) Class II region play important roles in immune response and protein degradation in neurodegenerative diseases. This study aimed to explore the association between single nucleotide polymorphisms (SNPs) of PSMB and TAP and Parkinson's disease (PD).

<b>METHODSb>A case-control study was conducted by genotyping SNPs in PSMB8, PSMB9, TAP1, and TAP2 genes in the Chinese population. Subjects included 542 sporadic patients with PD and 674 healthy controls. Nine identified SNPs in PSMB8, PSMB9, TAP1, and TAP2 were genotyped through SNaPshot testing.

<b>RESULTSb>The stratified analysis of rs17587 was specially performed on gender. Data revealed that female patients carry a higher frequency of rs17587-G/G versus (A/A + G/A) compared with controls. But there was no significant difference with respect to the genotypic frequencies of the SNPs in PSMB8, TAP1, and TAP2 loci in PD patients.

<b>CONCLUSIONb>Chinese females carrying the rs17587-G/G genotype in PSMB9 may increase a higher risk for PD, but no linkage was found between other SNPs in HLA Class II region and PD.

ATP-Binding Cassette Sub-Family B Member 2 ; genetics ; ATP-Binding Cassette, Sub-Family B, Member 3 ; genetics ; Adult ; Aged ; Antigen Presentation ; Case-Control Studies ; Cysteine Endopeptidases ; genetics ; Female ; Humans ; Male ; Middle Aged ; Parkinson Disease ; genetics ; immunology ; Polymorphism, Single Nucleotide ; Proteasome Endopeptidase Complex ; genetics

To study the effect of Siwu decoction on the function and expression of P-glycoprotein (P-gp) in Caco-2 cells. The Real-time quantitative poly-merase chain reaction (Q-PCR) was used to analyze the mRNA expression of MDR1 gene in Caco-2 cells. Flow cytometer was used to study the effect of Siwu decoction on the uptake of Rhodamine 123 in Caco-2 cells, in order to evaluate the efflux function of P-gp. Western blotting method was used to detect the effect of Siwu decoction on the P-gp protein expression of Caco-2 cells. Compared with the blank control group, after Caco-2 incubation with Siwu decoction at concentrations of 3.3, 5.0, 10.0 g x L(-1) for 24, 48, 72 h, the mRNA expression of MDR1 was up-regulated, suggesting the effect of Siwu decoction in inducing the expression of MDR1. After the administration with Siwu decoction in Caco-2 cells for 48 h, the uptake of Rhodamine 123 in Caco-2 cells decreased by respectively 16.6%, 22.1% (P < 0.05) and 45.4% (P < 0.01), indicating that the long-term administration of Siwu decoction can enhance the P-gp efflux function of Caco-2 cells. After the incubation of Caco-2 cells with Siwu decoction for 48 h, the P-gp protein expression on Caco-2 cell emebranes, demonstrating the effect of Siwu decoction in inducing the protein expression of P-gp.
ATP Binding Cassette Transporter, Sub-Family B ; genetics ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Caco-2 Cells ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Up-Regulation ; drug effects

<b>OBJECTIVEb>To explore the expression of breast cancer resistance protein (ABCG2), p-glycoprotein (P-gp) in residual breast cancer tissue after chemotherapy and their correlation with epithelial mesenchymal transition (EMT).

<b>METHODSb>Seventy-six cases of breast cancer were collected. The expression of ABCG2, P-gp and EMT markers E-cadherin and vimentin in residual breast cancer tissue after chemotherapy was detected by immunohistochemistry (EnVision method). MCF7 cells were divided into three group:untreated control group, positive control (TGF-β1 induced) group and drug surviving cells (DSC) group (selected viable MCF7 cells after docetaxel and epirubicin treatment). The expression of EMT markers E-cadherin and vimentin was detected by immunofluorescence. The mRNA and protein expression of ABCG2, P-gp and EMT markers were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively.

<b>RESULTSb>Compared with breast cancer tissue before chemotherapy, ABCG2, P-gp and vimentin protein were highly expressed in residual breast cancer tissue after chemotherapy. The expression of ABCG2 and P-gp correlated positively with vimentin protein (r1=0.97, P1=0.000; r2=0.83, P2=0.001) and negatively with E-cadherin protein (r3=-0.55, P3=0.010; r4=-0.43, P4=0.020) expression. RT-PCR results showed that ABCG2, P-gp and vimentin mRNA were highly expressed in residual breast cancer tissue after chemotherapy. The expression of ABCG2 and P-gp mRNA correlated positively with vimentin mRNA (r1=0.99, r2=0.96, P<0.05) but negatively with E-cadherin protein (r3=-0.99, r4=-0.98, P<0.05); Western blot showed that ABCG2, P-gp and vimentin protein were highly expressed in residual breast cancer tissue after chemotherapy. The expression of ABCG2 and P-gp protein correlated positively with vimentin protein (r1=0.98, r2=0.89, P<0.05) and negatively with E-cadherin protein (r3=-0.47, r4=-0.33, P<0.05).

<b>CONCLUSIONSb>The expression of resistance-associated proteins in the residual breast cancer tissue after chemotherapy is significantly correlated with EMT. The expression of EMT profile may be one of important mechanisms for multidrug resistance in breast cancer.

ATP Binding Cassette Transporter, Sub-Family B ; genetics ; metabolism ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Adult ; Aged ; Antibiotics, Antineoplastic ; pharmacology ; Antineoplastic Agents ; pharmacology ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Breast Neoplasms ; metabolism ; pathology ; therapy ; Cadherins ; genetics ; metabolism ; Cyclophosphamide ; therapeutic use ; Doxorubicin ; therapeutic use ; Epirubicin ; pharmacology ; Epithelial-Mesenchymal Transition ; Female ; Humans ; MCF-7 Cells ; Middle Aged ; Neoplasm Proteins ; genetics ; metabolism ; Neoplasm, Residual ; metabolism ; RNA, Messenger ; metabolism ; Taxoids ; pharmacology ; therapeutic use ; Vimentin ; genetics ; metabolism

Multidrug regimens and corresponding drug interactions cause many adverse reactions and treatment failures. Drug efflux transporters: P-glycoprotein (P-gp), multidrug resistance associated protein (MRP) and breast cancer resistance protein (BCRP) in conjunction with metabolizing enzymes (cytochrome P450, CYP450) are major factors in such interaction. In recent years, a large number of studies have shown that P-gp plays a role in the oxidative metabolism of its substrates that are also substrates of CYP3A4. Combined actions of P-gp and CYP3A could account in some part for the low oral bioavailability determined for many of these dual substrates. P-gp along with efflux transporters (MRP and BCRP) having overlapping substrate specificity plays critical role in drug disposition. The relationship between MRP or BCRP and CYP3A is similar to that between P-gp and CYP3A. In this paper, we summarize the classification of efflux transporters, the main metabolizing enzymes CYP3A, clinical significance interactions mediated by efflux transporters and CYP450 enzymes and in vitro studies.
ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Biological Availability ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Drug Interactions ; Humans ; Multidrug Resistance-Associated Proteins ; metabolism ; Neoplasm Proteins ; metabolism ; Substrate Specificity

<b>OBJECTIVEb>To investigate the reversal effect of targeted modulation of bcl-2 expression by miR-15a and miR-16 on drug resistance of human colon cancer cells.

<b>METHODSb>Mimics or inhibitors of miR-15a and miR-16 were transfected into HCT8 or HCT8/VCR cells with the help of Lipofectamine 2000. The expressions of miR-15a and miR-16 mRNA were detected by RT-qPCR. The levels of bcl-2 and P-gp proteins were measured by Western blot. The inhibitory effects of VCR on growth of HCT8 and HCT8/VCR cells were detected by CCK8.

<b>RESULTSb>After transfection of the mimics, the expression of miR-15a in the blank control group, negative control group and miR-15a mimic group was 1.00, 0.87 ± 0.24, and 223.44 ± 59.07, respectively, and miR-15a was increased significantly (P < 0.001). The expression of miR-16 in the blank control group, negative control group and miR-16 mimic group was 1.00, 0.66 ± 0.19, and 107.32 ± 22.58, respectively, and miR-16 expression was increased significantly (P < 0.001). The Western blot assay showed that the relative expressions of bcl-2 protein in the blank control group, negative control group, miR-15a mimic group and miR-16 mimic group were 1.00, 0.97 ± 0.02, 0.51 ± 0.06, and 0.65 ± 0.03, respectively, and the expression of bcl-2 protein was decreased significantly (P < 0.05), however, the expressions of P-gp protein showed no significant difference. The CCK8 test showed that at 1, 5, 25 and 125 µg/ml concentration of VCR, the survival rates of HCT8/VCR cells were basically the same in the blank control group, negative control group, miR-15a mimic group and miR-16 mimic group, but the survival rate of HCT8/VCR cells was significantly decreased after transfection of mimics (P < 0.05). After transfection of the inhibitors, the expressions of both miR-15a and miR-16 were decreased significantly (P < 0.001). The Western blot showed that the expression of bcl-2 protein was increased (P < 0.05), while the expression of P-gp protein showed no significant difference. The CCK8 test showed that the survival rate of HCT8 cells which were transfected with inhibitors was significantly higher than that of the blank control group (P < 0.05).

<b>CONCLUSIONSb>miR-15a and miR-16 may reverse the drug resistance in human colon cancer cells. A possible mechanism is regulating the expression of bcl-2.

ATP-Binding Cassette, Sub-Family B, Member 1 ; Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Cell Line, Tumor ; Colonic Neoplasms ; Drug Resistance ; Humans ; MicroRNAs ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; Transfection

<b>OBJECTIVEb>To evaluate the underlying mechanism of Jianpi Jiedu Recipe (, JJR) in the reversion of multidrug resistance concerning colorectal cancer in vitro and in vivo.

<b>METHODSb>Mice were treated orally with JJR at a daily 4.25 g/(kg·day) or injected with vinblastine (VCR) 2.5 mg/(kg·day) for 3 weeks after having been inoculated with HCT8/V cells; tumor tissues were assayed by hematoxylin and eosin staining. Firstly, the effects of JJR on the expression of cyclooxygenase-2 (COX-2) were tested by real-time polymerase chain reaction (PCR) technique and COX-2 gene silenced by siRNA. Secondly, the variation of intracellular concentration of oxaliplatin (L-OHP) was evaluated by the inductively coupled plasma mass spectroscopy (ICPMS) in HCT8/V and its COX-2 siRNA cells; the concentration of JJR combined with chemotherapeutic drugs and the reverse effect of multidrug resistance (MDR) in HCT8/V cells was evaluated by the MTT assay. Thirdly, real-time quantitative PCR and Western blot analysis were used to detect the multidrug resistance gene 1 (MDR1) mRNA and P-gp expression.

<b>RESULTSb>JJR had an inhibitory effect on the growth of tumors in vivo, and it, in combination with chemotherapeutic drugs, could reverse the drug-resistance of HCT8/V cells and increase the sensitivity of HCT8/V cells to VCR, DDP, 5-Fu, and THP. ICP-MS results showed that JJR could increase the concentration of drugs in HCT8/V cells (P<0.01). Furthermore, it was shown that JJR could reverse drug resistance of colorectal cancer cells by decreasing MDR1 expression and P-gp level via downregulation of COX-2, which has been represented as one of the major mechanisms that contributes to the MDR phenotype (P<0.01).

<b>CONCLUSIONb>JJR reversed multidrug resistance and enhanced the sensitivity to chemotherapy, which could be attributed to the down-regulation of COX-2 in MDR1/P-gp-mediated MDR colorectal cancer after chemotherapy.

ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Animals ; Cell Line, Tumor ; Cell Proliferation ; Colorectal Neoplasms ; drug therapy ; enzymology ; pathology ; Cyclooxygenase 2 ; genetics ; metabolism ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Green Fluorescent Proteins ; metabolism ; Humans ; Intracellular Space ; metabolism ; Mice, Inbred BALB C ; Organoplatinum Compounds ; metabolism ; RNA, Small Interfering ; metabolism ; Signal Transduction ; drug effects ; Vinblastine ; pharmacology ; therapeutic use ; Xenograft Model Antitumor Assays

<b>OBJECTIVEb>To explore the relationship between CD133(+) subsets cells in human gastric cancer (GC) and molecules of drug resistance and their sensitivity to 5-FU.

<b>METHODSb>Three gastric cancer cell lines therein KATO-III(, SGC7901 and MKN45 were sorted by immunomagnetic beads cell sorting method. Then above cell lines were further divided into un-sorted GC cells, CD133(+) subgroup and CD133(-) subgroup. The expressions of CD133, P-gp, Bax and Bcl-2 were determined by RT-PCR, Western blot and immunoflurescence. Meanwhile, the sensitivity to 5-FU of three subgroups was detected by CCK-8 Kit. The apoptosis induced by 5-FU in three subgroups was determined by Hoechst 33258.

<b>RESULTSb>Expressions of CD133 in three CD133(+) subgroups were significantly higher than those in un-sorted GC cells and CD133(-) subgroup (all P<0.05). Expressions of P-gp and Bcl-2 in the three GC cell lines were different (all P<0.05). There were significant differences of expressions of P-gp, Bcl-2 and Bax among CD133(+) cells, un-sorted GC cells and CD133(-) cells (all P<0.05). CCK-8 detection showed that CD133(-) subgroup of MKN45 GC cell line was more sensitive than CD133(+) cells to 5-FU (P<0.05). Hoechst 33258 staining showed that there were more apoptotic cells in CD133(-) subgroup as compared to other two subgroups, and the least apoptotic cells were observed in CD133(+) subgroup of MKN45 GC cell line (P<0.05). CD133 sirna was transfected into MKN45 GC cell line and could down-regulate the expressions of CD133, P-gp, Bcl-2 and p-Akt, while the expression of Bax increased (all P<0.05).

<b>CONCLUSIONSb>CD133 may contribute to the resistance of GC cells to chemotherapy drug through P-gp, Bcl-2 and Bax. PI3K/Akt signal pathway may be involved in this process.

AC133 Antigen ; ATP-Binding Cassette, Sub-Family B, Member 1 ; Antigens, CD ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Fluorouracil ; Glycoproteins ; metabolism ; Humans ; Peptides ; metabolism ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt ; RNA, Small Interfering ; Stomach Neoplasms ; drug therapy ; metabolism ; pathology ; bcl-2-Associated X Protein

<b>OBJECTIVEb>To compare the expression differences of breast cancer resistance protein(BCRP/ABCG2) and P-glycoprotein(P-gp) in breast cancer tissue before chemotherapy and in residual breast cancer tissue, and to explore its correlation with breast cancer stem cells.

<b>METHODSb>Immunohistochemistry was used to detect the expression of ABCG2, P-gp, and breast cancer stem cells(BCSCs) markers(CD44 and CD24) in breast cancer tissue before chemotherapy and residual breast cancer tissue after chemotherapy. Immunofluorescence was applied for determination of the CD44 and CD24 protein expressions of BCSCs microspheres cells. The monoclone-forming ability of BCSCs microspheres cells was detected by limited dilution assay. The expressions of ABCG2, P-gp, CD44, and CD24 proteins were detected by Western blot.

<b>RESULTSb>Compared with those in breast cancer tissue before chemotherapy, the expression levels of ABCG2 and P-gp were positively correlated with the expression level of CD44 protein(Χ(2)=41.34, r=0.83;Χ(2)=22.81, r=0.61) in residual breast cancer tissue after chemotherapy;meanwhile, they were negatively correlated with the expression of CD24 protein(Χ(2)=-21.25, r=0.72;Χ(2)=-17.26, r=0.65) (all P<0.05) .The diameter of BCSCs microspheres were increased significantly after chemotherapy.The content of BCSCs increased by about 2.5 times after chemotherapy.The expressions of ABCG2, P-gp and CD44 proteins significantly increased and that of CD24 protein significantly declined(P<0.05) .

<b>CONCLUSIONb>Chemotherapy endows residual breast cancer tissue with cancer stem cells-like features, leading to multidrug resistance of breast cancer.

ATP Binding Cassette Transporter, Sub-Family B ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Adult ; Aged ; Breast Neoplasms ; drug therapy ; metabolism ; CD24 Antigen ; metabolism ; Cell Culture Techniques ; Drug Resistance, Neoplasm ; Female ; Humans ; Hyaluronan Receptors ; metabolism ; Middle Aged ; Neoplasm Proteins ; metabolism ; Neoplasm, Residual ; Neoplastic Stem Cells ; cytology ; metabolism

<b>OBJECTIVEb>To detect the expression of PSF1 (partner of Sld five 1) in colon cancer specimens, and to explore the effect of RNA interference targeting PSF1 on the proliferation of colon cancer cells and its mechanism.

<b>METHODSb>Expression level of PSF1 protein in colon cancer specimens was detected by Western blot in 40 patients with colon cancer from May 2004 to December 2006. The short hairpin RNA (shRNA) plasmid targeting PSF1 was transfected into LOVO, HT-29 and HCT116 cells with liposome, then the expression level of PSF1 protein was measured by Western blot, the effect of PSF1 shRNA plasmid transfection on cell proliferation by MTT assay, anchorage-independent growth by soft agar colomy-formation assay, and PSF2, PSF3 and SLD5 mRNA expression by quantitative reverse transcription polymerase chain reaction.

<b>RESULTSb>The relative expression level of PSF1 protein in colon cancer tissues was 0.485±0.113, which was significantly higher than that in adjacent normal mucosa tissues (0.056±0.014, P<0.01). Western blot showed that the expression level of PSF1 protein was significantly decreased in colon cancer cells transfected with PSF1 shRNA plasmid. After PSF1 shRNA plasmid transfection, cell proliferation was significantly suppressed, the soft agar colony-forming rates of LOVO, HT-29 and HCT116 cells were significantly lower than those in control groups (P<0.05), meanwhile the expression levels of PSF2, PSF3 and SLD5 mRNA were significantly decreased (P<0.05).

<b>CONCLUSIONSb>PSF1 is significantly up-regulated in colon cancer tissues compared with adjacent normal mucosa tissues. ShRNA plasmid targeting PSF1 can inhibit the expression of PSF1 gene, suppress the proliferation of colon cancer cells, suggesting that it may be a new therapeutic target for colon cancer.

ATP-Binding Cassette Sub-Family B Member 2 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Adult ; Aged ; Cell Line, Tumor ; Cell Proliferation ; Colonic Neoplasms ; metabolism ; pathology ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; Middle Aged ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection

<b>OBJECTIVEb>To study the transport mechanism of baicalin of Scutellariae Radix extracts and the effect of Angelica dahurica extracts on the intestinal absorption of baicalin by using Caco-2 cell monolayer model, in order to analyze the effect mechanism of Angelica dahurica extracts on the intestinal absorption of baicalin.

<b>METHODb>The Caco-2 cell monolayer model was established with human colonic adenocarcinoma cells, and used to study the effect of pH, time, drug concentration and temperature on the transport of baicalin in Scutellariae Radix extracts, the effect of P-gp and MRP protein-dedicated inhibitors on the bidirectional transport of baicalin in Caco-2 cell model, and the effect of angelica root extracts on baicalin absorption and transport.

<b>RESULTb>Baicalin was absorbed well at 37 degrees C and under pH 7.4 condition and concentration dependent. Its proteins became inactive at 4 degrees C, with a low transport. The bi-drectional transfer PDR was 0. 54. After P-gp inhibitor verapamil and MRP inhibitor probenecid were added, the value of PappBL-AP of baicalin decreased, but without any difference in PDR. The transport of baicalin was improved by 2.34, 3.31 and 3.13 times, after A. dahurica extract coumarin, volatile oil, and mixture of coumarin and volatile oil.

<b>CONCLUSIONb>The transport mechanism of baicalin is mainly passive transfer and supplemented with efflux proteins involved. A. dahurica extracts can enhance the absorption of baicalin, which may be related to the passive transfer merchanism of baicalin. A. dahurica extracts' effect in opening the close junction among cells may be related to its expression or function in inhibiting efflux proteins.

ATP-Binding Cassette, Sub-Family B, Member 1 ; antagonists & inhibitors ; metabolism ; Angelica ; chemistry ; Biological Transport ; drug effects ; Caco-2 Cells ; Cell Line, Tumor ; Coumarins ; chemistry ; pharmacology ; Drug Interactions ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Flavonoids ; pharmacokinetics ; Humans ; Intestinal Absorption ; drug effects ; physiology ; Oils, Volatile ; chemistry ; pharmacology ; Plant Extracts ; chemistry ; pharmacology ; Plant Roots ; chemistry ; Probenecid ; pharmacology ; Scutellaria baicalensis ; chemistry ; Verapamil ; pharmacology