Biomedical subjects

Tao Wang

Publications and source records attributed to Tao Wang.

At least 127 records · Page 7Linked to original sources

PubMed2005

Overexpression of endoplasmic reticulum molecular chaperone GRP94 and GRP78 in human lung cancer tissues and its significance.

BACKGROUND: To investigate the relationship between the expression of glucose-regulated protein94 (GRP94) and GRP78 at the level of mRNA and protein in vivo and in human lung cancer. METHODS: RT-PCR, real-time PCR, immunohistochemistry and/or Western blot were used in 54 cases of lung cancer and corresponding normal lung tissue. RESULTS: The expression pattern of GRP94 and GRP78 was similar. There was a significant overexpression of GRP94 and GRP78 at both mRNA and protein levels in cancer tissues as compared to normal tissues. The relative levels of GRP94 and GRP78 mRNA evaluated by RT-PCR in cancer and normal lung tissue were: GRP94: 3.48+/-2.06 versus 2.01+/-1.83; GRP78: 3.64+/-1.87 versus 2.21+/-1.54; by real-time PCR were: GRP94: 2.89+/-0.64 versus 1.12+/-0.54; GRP78: 2.56+/-0.82 versus 0.96+/-0.42. The relative level of GRP94 and GRP78 protein by Western blot in cancer and normal lung tissue were: GRP94: 3.46+/-1.72 versus 1.81+/-0.92; GRP78: 4.84+/-2.55 versus 1.91+/-1.15, indicating an approximate 2-fold and a 3-fold increase in GRP94 and GRP78 protein in cancer tissue as compared with normal tissue. Immunohistochemistry result for GRP94 and GRP78 in cancer and normal tissue was similar, that is: a stronger stain was observed in cancer tissue (main intensity of staining ++ to +++) compared to normal tissue (main intensity of staining + to ++). All the difference for GRP94 and GRP78 between the two tissues were significant (p<0.05). Furthermore, the overexpression of GRP94 and GRP78 in the cancer tissue correlated with grade of differentiation and stage of tumors. There was stronger expression in poorly differentiated tumors than in well-moderately differentiated tumors (p<0.05). There was also stronger expression in stage III than in stages I and II tumors (p<0.05). No statistically significant differences were found among various pathologic types of tumors. Correlation analysis showed that there is a positive correlation between GRP94 and GRP78. CONCLUSION: The expression pattern of GRP94 and GRP78 was similar in human lung cancer. They both were related with the differentiation and progression of the cancer. The expression at mRNA and protein level may be valuable in evaluating the grade of differentiation and clinical stage of human lung cancer.

Adult↗

PubMed2005

[Surgical treatment of primary pulmonary cryptococcosis].

OBJECTIVE: To assess the clinical feature, diagnosis and treatment of primary pulmonary cryptococcosis. METHODS: From 1996 to 2004, 11 patients with primary pulmonary cryptococcosis were surgical treated and confirmed by histologic study. At the same period, 2715 patients with pulmonary abnormalities received surgery. Their clinical data were retrospectively reviewed. RESULTS: Sixty-four percent (7/11) of the patients were symptomatic at the time of diagnosis. All 11 cases were misdiagnosed as lung cancer or inflammatory or tuberculosis by X-ray and CT scan before surgery. Three cases received fluorine-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) scan and their primary pulmonary lesions showed FDG avid. All 11 patients were treated by antibiotics and antituberculosis therapy but no responses appeared. Primary pulmonary cryptococcosis was diagnosed by ultrasound-guided fine needle aspiration biopsy in only 2 cases, but antifungal therapy was not effective. All 11 patients underwent thoracotomy and their pulmonary cryptococcosis were resected. Only 1 patient with multiple nodules received antifungal therapy postoperatively. No recurrence was found in any patients. CONCLUSIONS: Primary pulmonary cryptococcosis is non-specific and can be confused with lung cancer, tuberculosis, etc. The pulmonary abnormalities should be resected unless the diagnosis is established. Antifungal therapy is not necessary in patients whose abnormality has been resected thoroughly.

Adult↗

PubMed2005

Schistosoma mansoni infection promotes SHIV clade C replication in rhesus macaques.

OBJECTIVE: To evaluate the hypothesis that parasitic infections that induce T-helper type 2 (Th2) immune responses, such as schistosomiasis, upregulate HIV-1 replication. DESIGN: The effect of concomitant Schistosoma mansoni infection was tested in a primate model of acute and chronic simian-human immunodeficiency virus (SHIV) infection in rhesus macaques using a novel SHIV strain encoding the R5 env gene of a primary HIV clade C isolate from sub-Saharan Africa. METHODS: S. mansoni-infected rhesus macaques and controls were exposed to SHIV to assess the effects of schistosomiasis on acute viral infection. Effects on chronic viral infection were evaluated by exposing virus-infected animals to parasites. S. mansoni infection was confirmed by the presence of parasite eggs in stool and eosinophilia. Viral RNA loads, cytokine and chemokine mRNA expression were measured by real time reverse transcription-PCR. RESULTS: S. mansoni coinfection increased the expression of Th2-associated cytokine responses and SHIV replication during both acute and chronic phases of SHIV infection. CONCLUSIONS: These results support the hypothesis that concomitant schistosomiasis upregulates replication of immunodeficiency viruses in coinfected hosts, raising the possibility that parasite-infected individuals may also be more susceptible to acquisition of HIV-1 infection.

AIDS-Related Opportunistic Infections↗

PubMed2005

Paclitaxel modulates TGFbeta signaling in scleroderma skin grafts in immunodeficient mice.

BACKGROUND: Systemic sclerosis (SSc) is characterized by excessive fibrosis and obliterative vascular lesions. Abnormal TGFbeta activation is implicated in the pathogenesis of SSc. Aberrant TGFbeta/Smad signaling can be controlled by stabilization of microtubules with paclitaxel. METHODS AND FINDINGS: SSc and healthy human skin biopsies were incubated in the presence or absence of paclitaxel followed by transplantation into severe combined immunodeficient mice. TGFbeta signaling, fibrosis, and neovessel formation were evaluated by quantitative RT-PCR and immunohistochemical staining. Paclitaxel markedly suppressed Smad2 and Smad3 phosphorylation and collagen deposition in SSc grafts. As a result, the autonomous maintenance/reconstitution of the SSc phenotype was prevented. Remarkably, SSc grafts showed a 2-fold increase in neovessel formation relative to normal grafts, regardless of paclitaxel treatment. Angiogenesis in SSc grafts was associated with a substantial increase in mouse PECAM-1 expression, indicating the mouse origin of the neovascular cells. CONCLUSION: Low-dose paclitaxel can significantly suppress TGFbeta/Smad activity and lessen fibrosis in SCID mice. Transplantation of SSc skin into SCID mice elicits a strong angiogenesis-an effect not affected by paclitaxel. Although prolonged chemotherapy with paclitaxel at higher doses is associated with pro-fibrotic and anti-angiogenic changes, the findings described here indicate that low-dose paclitaxel may have therapeutic benefits for SSc via modulating TGFbeta signaling.

Adult↗

PubMed2005

Differential effects of B and T lymphocyte attenuator and programmed death-1 on acceptance of partially versus fully MHC-mismatched cardiac allografts.

Although fully MHC-mismatched murine cardiac allografts are rapidly rejected, allografts mismatched at only MHC class I or class II alleles survive long term; the immunologic basis for the long-term survival of MHC class I- or II-mismatched allografts is unknown. We examined the roles of two recently described inhibitory receptors, B and T lymphocyte attenuator (BTLA) and programmed death-1 (PD-1), in the survival of partially or fully MHC-mismatched allografts using gene-deficient recipients as well as through use of blocking mAbs in wild-type hosts. Partially MHC-mismatched allografts showed strong induction of BTLA, but not PD-1 mRNA and survived long term in wild-type recipients, whereas targeting of BTLA or its ligand, herpesvirus entry mediator, but not PD-1, prompted their rapid rejection. By contrast, fully MHC-mismatched cardiac allografts were acutely rejected in wild-type recipients despite the induction of both BTLA and PD-1. Targeting of PD-1 in several fully MHC-mismatched models accelerated rejection, whereas targeting of BTLA unexpectedly enhanced PD-1 induction by alloreactive CD4 and CD8 T cells and prolonged allograft survival. In vitro studies using allogeneic dendritic cells and T cells showed that at low levels of T cell activation, BTLA expression was primarily induced, but that with increasing degrees of T cell activation, the expression of PD-1 was strongly up-regulated. These data suggest that BTLA and PD-1 exert distinct inhibitory actions in vivo, with the BTLA/herpesvirus entry mediator pathway appearing to dominate in regulating responses against a restricted degree of allogeneic mismatch.

Animals↗

PubMed2005

Metabolic acidosis in peritoneal dialysis patients: the role of residual renal function.

BACKGROUND: Metabolic acidosis (MA) is common in chronic renal insufficiency (CRI) patients, and its pattern changes as renal function deteriorates. Although the prevalence of acidosis in peritoneal dialysis has been reported to be rather high, the causes of it have not been well studied. The present study was performed to examine the prevalence of metabolic acidosis in our continuous ambulatory peritoneal dialysis (CAPD) patients and its possible causes. METHODS: In this cross-sectional study, we analyzed data from patients who received maintenance CAPD in our hospital and had been on dialysis for at least one month. Patients' demographic features, medications, and intercurrent medical conditions were recorded. Data including blood biochemistry, dialysis adequacy, and nutrition were collected. A serum bicarbonate concentration of less than 23 mmol/l was defined as having acidosis. The normal value of the serum anion gap (AG) was defined as 12+/- 4 mmol/l. RESULTS: A total of 154 patients (76 males and 78 females) with age of 60.04+/- 13.92 years and the time on dialysis of 16.83+/- 21.59 months were included in this study. Sixty-six patients (43%) had a serum bicarbonate of less than 23 mmol/l, among whom 12 patients (8%) were identified as having MA with increased AG, 54 (35%) were identified as having MA with normal AG. Patients who had better residual renal function (RRF) had a significantly lower serum bicarbonate level despite their higher total KT/V(urea) as compared to those with lower RRF. In addition, patients with MA and normal AG had the highest RRF and highest total KT/V(urea). All patients with MA and increased AG had significantly lower values of dietary protein intake (DPI) as compared to their values of normalized protein nitrogen appearance (nPNA), and had higher serum urea and phosphate levels as compared with those patients without MA. CONCLUSION: Our study suggested that CAPD patients with better RRF were more susceptible to metabolic acidosis, which was characterized by normal anion gap and hyperchloremia. Thus, we speculate that renal loss of bicarbonate may to a large extent be responsible for the occurrence of MA in these patients.

Acidosis↗

PubMed2005

[Study on the effect of adrenomedulin and urotensin-II on pulmonary hypertension of patients with congenital heart disease].

OBJECTIVE: To evaluate the effect and clinical significance of adrenomedulin (ADM) and urotensin-II (UII) on pulmonary hypertension (PH), by detecting their levels of patients with congenital heart disease and pulmonary hypertension. METHODS: 52 patients with congenital heart disease who had left-to-right shunt were selected randomly. 52 patients were divided three groups according to pulmonary artery systolic pressure (PASP): group A was not pulmonary hypertension (PASP < 30 mm Hg, n = 17); group B was mild pulmonary hypertension (PASP30-49 mm Hg, n = 18); group C was moderate and severe pulmonary hypertension (PASP > or = 50 mm Hg, n = 17). The plasma levels of ADM and UII were detected at each period by radioimmunoassay (RIA) method. It was analyzed the changes of their levels within pre-operation, 20 mins and 7 days post-operation and the interrelation between them and PASP. RESULTS: (1) Following the severity degree of pulmonary hypertension, the plasma levels of ADM increase. There is positive correlation between PAP and plasma level of ADM (pre-operation r = 0.8012, P < 0.01; 20 min post-operation r = 0.6325, P < 0.01; 7 d post-operation r = 0.7126, P < 0.01). (2) Following the severity degree of pulmonary hypertension, the plasma levels of UII don't change obviously. There is no correlation between PAP and plasma level of UII (P > 0.05). (3) The plasma levels of ADM: group A (pre-operation: 33 pg/ml +/- 5 pg/ml, 20 mins post-operation: 29 pg/ml +/- 4 pg/ml, 7 d post-operation: 20 pg/ml +/- 3 pg/ml); group B (pre-operation: 44 pg/ml +/- 8 pg/ml, 20 mins post-operation: 40 pg/ml +/- 6 pg/ml, 7 d post-operation: 34 pg/ml +/- 4 pg/ml); group C (pre-operation: 60 pg/ml +/- 10 pg/ml, 20 mins post-operation: 58 pg/ml +/- 8 pg/ml, 7d post-operation: 38 pg/ml +/- 4 pg/ml). Plasma level of ADM of each group after CPB is lower than that of each group before operation. It is statistical difference only 7 days post-operation (group A q = 5.41, P < 0.01; group B q = 4.76, P < 0.01; group C q = 6.32, P < 0.01). (4) The plasma levels of UII: group A (pre-operation: 2.2 pmol/L +/- 0.5 pmol/L, 20 mins post-operation: 2.2 pmol/L +/- 0.44 pmol/L, 7 d post-operation: 2.2 pmol/L +/- 0.6 pmol/L); group B (pre-operation: 2.7 pmol/L +/- 0.6 pmol/L, 20 mins post-operation: 2.6 pmol/L +/- 0.6 pmol/L, 7 d post-operation: 2.6 pmol/L +/- 0.5 pmol/L); group C (pre-operation: 2.9 pmol/L +/- 0.6 pmol/L, 20 mins post-operation: 2.6 pmol/L +/- 0.7 pmol/L, 7 d post-operation: 2.8 pmol/L +/- 0.4 pmol/L). Compared with that of each group before operation, Plasma level of UII of each group after operation is no obvious difference (P > 0.05). CONCLUSION: (1) Following the severity degree of pulmonary hypertension, the plasma levels of ADM increase. ADM plays an important role in the formation of pulmonary hypertension and restructure. (2) Following the severity degree of pulmonary hypertension, the plasma levels of UII don't change obviously. There is no correlation between PAP and plasma level of UII, but UII may be play an important role in the formation of pulmonary hypertension and restructure. (3) Measuring the levels of ADM may be a reliable method to follow the change of pulmonary pressure and worsening of pulmonary hypertension.

Adolescent↗

PubMed2005

Synthesis and biological evaluation of deoxy salacinols, the role of polar substituents in the side chain on the alpha-glucosidase inhibitory activity.

Three analogs (5, 6, and 7) lacking polar substituents in the side chain of a naturally occurring alpha-glucosidase inhibitor, salacinol (1a), were synthesized by the coupling reaction of a thiosugar, 1,4-dideoxy-1,4-epithio-D-arabinitol (3), with cyclic sulfates (8, 9, and 10), and their alpha-glucosidase inhibitory activities were examined. All these simpler analogs (5, 6, and 7) showed less inhibitory activity compared to 1a, and proved the importance of cooperative role of the polar substituents for the alpha-glucosidase inhibitory activity. A practical synthetic route to 3 starting from D-xylose is also described.

Animals↗

PubMed2005

Schisandrin B--a novel inhibitor of P-glycoprotein.

P-glycoprotein-mediated drug efflux is one of the major causes of the cancer multidrug resistance (MDR). Inhibition of P-glycoprotein could reverse cancer MDR. Here, we show that schisandrin B, a naturally occurring compound from Schisandra chinensis (Turcz.) Baill, bears strong potency to inhibit P-glycoprotein. Schisandrin B reversed the drug resistance of four MDR cell lines characterized with overexpression of P-glycoprotein and fully restored the intracellular drug accumulation by interacting with P-glycoprotein. Schisandrin B has a core structure of dibenzocyclooctadiene, representing a novel P-glycoprotein inhibitor. To our best knowledge, the role of schisandrin B to inhibit P-glycoprotein has not been reported.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2005

The effect of substituents on electronic states' ordering in meta-xylylene diradicals: qualitative insights from quantitative studies.

Equation-of-motion spin-flip coupled-cluster method with single and double substitutions (EOM-SF-CCSD) is employed to study how substituents affect the electronic states' ordering in meta-xylylene diradicals. The electronegativity of substituents and the incorporation of a heteroatom are found to have a negligible effect. The effect of charges on energy gaps is much more pronounced, in agreement with the proposal of Dougherty and co-workers [J. Am. Chem. Soc. 118, 1452 (1996)]. Resonance structure theory and molecular orbital analysis are employed to explain this phenomenon. The changes in the exocyclic C-C bond length in substituted meta-xylylenes, derived from equilibrium structures calculated by using analytic gradients for the EOM-SF-CCSD method, support the original resonance theory explanation by West et al. However, a similar resonance-theory-based reasoning fails to explain the quantitative difference between positively and negatively charged systems as well as the observed strong stabilization of an open-shell singlet state in the N-oxidized pyridinium analog of meta-xylylene.

Journal Article↗

PubMed2005

Gene expression in rats with Barrett's esophagus and esophageal adenocarcinoma induced by gastroduodenoesophageal reflux.

AIM: To study the different gene expression profiles in rats with Barrett's esophagus (BE) and esophageal adenocarcinoma (EA) induced by gastro-duodeno-esophageal reflux. METHODS: Esophagoduodenostomy was performed in 8-wk old Sprague-Dawley rats to induce gastro-duodeno-esophageal reflux, and a group of rats that received sham operation served as control. Esophageal epithelial pathological tissues were dissected and frozen in liquid nitrogen immediately. The expression profiles of 4096 genes in EA and BE tissues were compared to normal esophagus epithelium in normal control (NC) by cDNA microarray. RESULTS: Four hundred and forty-eight genes in BE were more than three times different from those in NC, including 312 upregulated and 136 downregulated genes. Three hundred and seventy-seven genes in EA were more than three times different from those in NC, including 255 upregulated and 142 downregulated genes. Compared to BE, there were 122 upregulated and 156 downregulated genes in EA. In the present study, the interested genes were those involved in carcinogenesis. Among them, the upregulated genes included cathepsin C, aminopeptidase M, arachidonic acid epoxygenase, tryptophan-2,3-dioxygenase, ubiquitin-conjugating enzyme, cyclic GMP-stimulated phosphodiesterase, tissue inhibitor of metalloproteinase-1, betaine-homocysteine methyltransferase, lysozyme, complement 4b binding protein, complement 9 protein, insulin-like growth factor binding protein, UDP-glucuronosyltransferase, tissue inhibitor of metalloproteinase-3, aldolase B, retinoid X receptor gamma, carboxylesterase and testicular cell adhesion molecule 1. The downregulated genes included glutathione synthetase, lecithin-cholesterol acyltransferase, p55CDC, heart fatty acid binding protein, cell adhesion regulator and endothelial cell selectin ligand. CONCLUSION: Esophageal epithelium exposed excessively to harmful ingredients of duodenal and gastric reflux may develop into BE and even EA gradually. The gene expression level is different between EA and BE, and may be related to the occurrence and progression of EA.

Adenocarcinoma↗

PubMed2005

Oral immunization with pBsVP6-transgenic alfalfa protects mice against rotavirus infection.

A critical factor in edible plant-derived vaccine development is adequate expression of the exogenous antigens in transgenic plants. We synthesized a codon-optimized gene (sVP6) encoding the VP6 protein of human group A rotavirus and inserted it into the alfalfa genome using agrobacterium-mediated transformation. As much as 0.28% of the total soluble protein of the pBsVP6-transgenic alfalfa was sVP6. Female BALB/c mice were gavaged weekly with 10 mg of transgenic alfalfa extract containing 24 microg of sVP6 protein and 10 microg of CpG-rich oligodeoxynucleotides as mucosal adjuvant. Immunized mice developed high titers of anti-VP6 serum IgG and mucosal IgA. Offspring of immunized dams developed less severe diarrhea after challenge with simian rotavirus SA-11, indicating that antibodies generated in the dams provided passive heterotypic protection to the pups. These results suggest that oral immunization with pBsVP6-transgenic alfalfa provides a potential means of protecting children and young animals from severe acute rotavirus-induced diarrhea.

Administration, Oral↗

PubMed2005

Diabetic patients can do as well on peritoneal dialysis as nondiabetic patients.

BACKGROUND: It is not uncommon that diabetic peritoneal dialysis (PD) patients are volume overloaded and this may have contributed to the inferior outcome of diabetic patients. In the present cohort study, we compared the difference between diabetics and nondiabetics during the first year of PD after implementing strict volume control. METHODS: Seventeen diabetic and 40 nondiabetic incident PD patients were followed for 1 year. Fluid status was evaluated by bioimpedance analysis and blood pressure. Nutritional status was evaluated by subjective global nutritional assessment. RESULTS: At the initiation, compared with the nondiabetics, diabetics had a significantly higher extracelluar volume, systolic blood pressure and lower serum albumin. One year later, there were no statistical differences in these parameters between the two groups. The prevalence of malnutrition decreased in all patients, although malnutrition remained slightly higher in diabetic patients. CONCLUSIONS: Our study suggests that diabetics can do as well as nondiabetics on PD. Appropriate diabetic care, especially strict volume control, may be critical for the success of diabetic patients on PD treatment.

Adult↗

PubMed2005

Mutation of DNA polymerase beta in esophageal carcinoma of different regions.

AIM: To observe the variation of DNA polymerase beta (polbeta) in esophageal carcinoma. METHODS: Thirty specimens containing adjacent normal epithelial tissues were collected from patients in Linzhou region (a high risk area for esophageal squamous carcinoma) and 25 specimens were from a non-high risk area. Total RNA was extracted from the samples and reverse transcription polymerase chain reaction (RT-PCR) was performed. PCR products were cloned and sequenced to investigate the polbeta gene with DNASIS and OMIGA. Statistical significance was evaluated using the chi(2) test. RESULTS: High-incidence area group: polbeta gene variation was detected in 13 of 30 esophageal carcinoma tissue specimens, and only one variation was found in 30 corresponding adjacent normal tissue specimens. Non high-incidence area group: polbeta gene variation was detected in 5 of 25 esophageal carcinoma tissue specimens, and no variation was found in 25 corresponding adjacent normal tissue specimens. The incidence of polbeta gene variation observed in the high-incidence area group was significantly higher than in the non-high incidence area group. Two mutation hot spots (454-466 and 648-670 nt) and a 58 bp deletion (177-234 nt) were found. CONCLUSION: Variations of polbeta perform different functions between the high-incidence areas and the other areas, and may play a more important role in the high-incidence areas.

Base Sequence↗

PubMed2005

1.88 A crystal structure of the C domain of hCyP33: a novel domain of peptidyl-prolyl cis-trans isomerase.

Cyclophilins (CyPs) are a widespreading protein family in living organisms and possess the activity of peptidyl-prolyl cis-trans isomerase (PPIase), which is inhibited by cyclosporin A (CsA). The human nuclear cyclophilin (hCyP33) is the first protein which was found to contain two RNA binding domains at the amino-terminus and a PPIase domain at the carboxyl-terminus. We isolated the hCyP33 gene from the human hematopoietic stem/progenitor cells and expressed it in Escherichia coli, and determined the crystal structure of the C domain of hCyP33 at 1.88 A resolution. The core structure is a beta-barrel covered by two alpha-helices. Superposition of the structure of the C domain of hCyP33 with the structure of CypA suggests that the C domain contains PPIase active site which binds to CsA. Furthermore, C domain seems to be able to bind with the Gag-encoded capsid (CA) of HIV-1 and may affect the viral replication of HIV-1. A key residue of the active site is changed from Ala-103-CypA to Ser-239-hCyP33, which may affect the PPIase domain/substrates interactions.

Crystallography, X-Ray↗

PubMed2005

Simultaneous analysis of insect repellent DEET, sunscreen oxybenzone and five relevant metabolites by reversed-phase HPLC with UV detection: application to an in vivo study in a piglet model.

N,N-Diethyl-m-toluamide (DEET) and oxybenzone are two essential active ingredients in insect repellent and sunscreen preparations. We developed and validated a simple, sensitive, and selective HPLC assay to simultaneously measure DEET, oxybenzone and five primary metabolites of DEET and oxybenzone in biological samples including plasma, urine and skin strips. The compounds were separated on a reversed-phase C18 column using three-stage gradient steps with methanol and water. DEET and two relevant metabolites were detected at 254 nm, while oxybenzone and three relevant metabolites were detected at 289 nm. The limit of detection was 0.6 ng for DEET and 0.5 ng for oxybenzone, respectively. The developed method was further applied to analyze various biological samples from an in vivo animal study that evaluated concurrent use of commercially available insect repellent and sunscreen preparations.

Animals↗

PubMed2005

[Effects of schisandrin B on reversing multidrug resistance in human breast cancer cells transfected with mdr1 gene].

OBJECTIVE: To investigate the multidrug resistance (MDR) reversal activity of schisandrin B (SchB) in transfected human breast cancer cell line MCF-7/MDR1. METHODS: Human breast cancer cells of the line MCF-7 were cultured and transfected with mdr1 gene so as to establish a P-glycoprotein (P-gp) stable-expressing cell line MCF-7/MDR1. The expression of P-gp in the MCF-7/mdr1 cells was assayed by flow cytometry using fluorescent antibody. MCF-7 cells transfected with blank plasmid MCF-7/neo was used as controls. Adriamycin (ADR), verapamil (VER), pacilitaxel (taxol), and homoharringtonine (HHT) were added into the culture fluid of the MCF-7/mdr1 cells and MTT method was used to detect the IC(50) of these drugs. The culture fluid of the MCF-7/MDR1 cells was added with SchB of the concentrations of 2.5, 12.5, 25, and 50 micromol/L and then added with ADR1 cells, MTT method was used to calculate the reversal effect (RF) of SchB on the MDR phenotype of the MCF-7/mdr1 cells. MTT method was used to calculate the RF. Another culture fluid of MCF-7/mdr1 cells was added with 25 micromol/L SchB and then with ADR, vincristine (VCR), pacilitaxel, and HHT with that added with 10 micromol/L VER as control. After treatment with SchB the MF7/mgr1 cells were co-incubated with 5 micromol/L rhodamine (Rh)-123, then flow cytometry was used to detect the accumulation of Rh-123 within the cells. After treatment with 25 micromol/L SchB for 0, 0.5, 1, 6, 24, 48, and 72 hours flow cytometry was used to detect the P-gp expression in the MF7/mgr1 cells. RESULTS: The transfected MCF-7/MDR1 cells overexpressed P-gp and exhibited resistance to multiple drugs, including ADR, VCR, pacilitaxel and HHT. SchB (25 micromol/L) significantly enhanced the sensitivity of the MCF-7/MDR1 cells to above mentioned chemotherapeutic agents, with a reversal factors of 6.03 to 23.94 times. The effect of SchB (25 micromol/L) on Rh-123 accumulation in MDR cells was equivalent to that of 10 micromol/L VER, however no significant difference was found in the effect of SchB (25 micromol/L) on the P-gp expression in the MCF-7/MDR1 cells. CONCLUSION: SchB is able to restore the drug sensitivity in the transfected MCF7/MDR1 cells, with a possible mechanism of increasing the drug influx via inhibiting the P-gp function.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2005

Differences in biological features of gastric dysplasia, indefinite dysplasia, reactive hyperplasia and discriminant analysis of these lesions.

AIM: To investigate the differences in biological features of gastric dysplasia (Dys), indefinite dysplasia (IDys) and reactive hyperplasia (RH) by studying the biomarker alterations in cell proliferation, cell differentiation, cell cycle control and the expression of house-keeping genes, and further to search for markers which could be used in guiding the pathological diagnosis of three lesions. METHODS: Expressions of MUC5AC, MUC6, adenomatous polyposis coli (APC), p53, Ki-67, proliferation cell nuclear antigen (PCNA) and EGFR were studied by immunohistochemistry with a standard Envision technique in formalin-fixed and paraffin-embedded specimens from 43 RH, 35 IDys, 35 Dys and 36 intestinal type gastric carcinomas (IGC). In addition, Bayes discriminant analysis was used to investigate the value of markers studied in differential diagnosis of RH, IDys, Dys and IGC. RESULTS: The MUC5AC and MUC6 antigen expressions in RH, IDys, Dys and IGC decreased gradually (MUC5AC: 86.04%, 77.14%, 28.57%, 6.67%; MUC6: 65.15%, 54.29%, 20.00%, 25.00%, respectively). The expressions of the two markers had no significant difference between RH and IDys, but were all significantly higher than those of the other two lesions (MUC5AC: chi2=27.607, 38.027 and 17.33, 26.092; MUC6: chi2=16.54, 12.665 and 9.282, 6.737, P<0.01). There was no significant difference between RH and IDys, Dys and IGC in MUC6 expression. The APC gene expression in the four lesions had a similar decreasing tendency (RH 69.76%, IDys 68.57%, Dys 39.39%, IGC 22.86%), and it was significantly higher in the first two lesions than in the last two (chi2=7.011, 16.995 and 14.737, 19.817, P<0.05). The p53 expression in RH, IDys, Dys and IGC was 6.98%, 20%, 57.14% and 50%, respectively. There was no significant difference between RH and IDys or Dys and IGC, but the p53 expression in RH and IDys was significantly lower than that in Dys and IGC (chi2=7.011, 16.995 and 14.737, 19.817, P<0.01). The Ki-67 label index was significantly different among four lesions (RH: 0.298+/-8.92%, IDys: 0.358+/-9.25%, Dys: 0.498+/-9.03%, IGC: 0.620+/-10.8%, P<0.001). Positive immunostaining of PCNA was though observed in all specimens, significant differences were detected among four lesions (F=95.318, P<0.01). In addition, we used Bayes discriminant analysis to investigate molecular pathological classification of the lesions, and obtained the best result with the combination of MUC5AC, Ki-67 and PCNA. The overall rate of correct classification was 67.4% (RH), 68.6% (IDys), 70.6% (Dys) and 84.8% (IGC), respectively. CONCLUSION: Dys has neoplastic biological characteristics, while RH and IDys display hyperplastic characteristics. MUC5AC and proliferation-related biomarkers (Ki-67, PCNA) are more specific in distinguishing Dys from RH and IDys.

Biomarkers↗