PAG1 stimulates proliferation and metastasis of nasopharyngeal carcinoma through downregulating PTEN.

OBJECTIVE: We aim to uncover the expression pattern and biological functions of PAG1 in the progression of nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: PAG1 levels in 28 paired NPC tissues and paracancerous tissues were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Then, the potential influences of PAG1 on proliferative, migratory and invasive abilities of SUNE2 and CNE2 cells were assessed by cell counting kit-8 (CCK-8) and transwell assay, respectively. Next, the interaction between PAG1 and its direct target gene of phosphate and tension homology deleted on chromosome ten (PTEN) was verified by Dual-Luciferase reporter gene assay. At last, rescue experiments were conducted to uncover the role of PAG1/PTEN axis in the malignant progression of NPC. RESULTS: PAG1 was highly expressed in NPC tissues and cell lines. Knockdown of PAG1 blocked NPC cells to proliferate, migrate, and invade. Dual-Luciferase reporter gene assay indicated the binding relationship between PAG1 and PTEN. In addition, both mRNA and protein levels of PTEN were negatively regulated by PAG1 in NPC cells. Notably, PTEN was responsible for PAG1-regulated malignant progression of NPC. CONCLUSIONS: PAG1 is upregulated in NPC tissues and cells and stimulates the proliferative and metastatic abilities in NPC by targeting PTEN, thus aggravating the malignant progression of NPC.

HBP1 deficiency protects against stress-induced premature senescence of nucleus pulposus.

OBJECTIVE: Senescence of nucleus pulposus (NP) cells is involved in the pathological process of intervertebral disc degeneration (IVDD). HMG-box transcription factor 1 (HBP1) is a transcriptional inhibitor that prevents proliferation and regulates premature senescence of cells. The aim of this study was to confirm whether HBP1 deficiency could protect stress-induced NP cells premature senescence. PATIENTS AND METHODS: Firstly, HBP1 protein level in human degenerated intervertebral disc tissues was detected. Then, NP cells were isolated from disc samples and transfected with plasmid to upregulate HBP1expression. H2O2 and interleukin-1b (IL-1b) were used to induce NP cells premature senescence in a different manner. Thereafter, cell viability, proliferation, and apoptosis were measured, and the protein expressions of collagen II, HBP1, and p16, were determined by Western blot or immunofluorescence. Finally, the mRNA levels of aggrecan, collagen I, IL-6, Transforming Growth Factor-α (TNF-α), and matrix metalloproteinase-3 (MMP-3) were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). RESULTS: The data indicated that HBP1 was upregulated in degenerated NP tissues. HBP1 gene overexpression increased p16 expression, affected NP cell proliferation, and caused cell apoptosis. In addition, HBP1 also decreased the collagen II and aggrecan expressions but increased collagen I, IL-6, TNF-α, and MMP-3 levels. Moreover, the silencing of HBP1 markedly reversed the H2O2 and IL-1b induced NP cell senescence by reducing p16 expression, apoptotic cell population, and inflammatory response and by promoting cell proliferation. CONCLUSIONS: In summary, HBP1 accumulation contributes to the senescence of NP cells, and HBP1 deficiency protects stress-induced NP cells premature senescence.

Evaluating the ability of the Sodergren score to guide the management of internal haemorrhoidal disease.

AIM: The Sodergren score was developed to objectively measure the severity of haemorrhoidal symptoms. This study aimed to determine if there was a difference in the Sodergren score between patients who were offered surgery and patients who underwent successful rubber band ligation of internal haemorrhoidal disease and to assess its performance in guiding management. METHOD: This is a prospective, observational study. The preintervention Sodergren scores of subjects with internal haemorrhoidal disease were recorded and blinded to the surgeon in charge. Sodergren scores of subjects in the two arms were unblinded and compared at the end of the study. RESULTS: The results for 290 patients were available for final analysis. The median scores of those offered surgery and those who underwent successful rubber band ligation differed significantly [4 (interquartile range 3-10) vs 0 (interquartile range 0-4), P = 0.001]. In predicting treatment, the Sodergren score had an area under the receiver operating characteristic curve of 0.735 (95% CI 0.675-0.795). CONCLUSION: There is a significant difference in scores between patients who were offered surgery and patients with successful rubber band ligation. Our study suggests that the Sodergren score has an acceptable discrimination in predicting the need for surgery in internal haemorrhoidal disease. We propose that patients with a Sodergren score of 6 or more be considered for upfront surgery. This score could potentially be used to standardize outcomes of future haemorrhoid trials.

Apelin-13/APJ system delays intervertebral disc degeneration by activating the PI3K/AKT signaling pathway.

OBJECTIVE: To study the effect of Apelin-13/APJ system on intervertebral disc degeneration and its mechanism. PATIENTS AND METHODS: This study detected the expression of APJ in human intervertebral disc tissue with varying degrees of degeneration. IL-1ß is used to stimulate the degeneration of nucleus pulposus cells. We used recombinant human Apelin-13 and Ala13 to activate and inhibit the APJ receptor, respectively. The inhibitor LY294002 was used to inhibit the PI3K/AKT signaling pathway. We studied the effects of Apelin-13/APJ system on nucleus pulposus cells and its mechanism by Western blot, RT-PCR, and so on. RESULTS: APJ is lowly expressed in the nucleus pulposus of patients with a high degree of degeneration. IL-1ß stimulates the nucleus pulposus cells and reduces the expression of APJ in nucleus pulposus cells. Recombinant human Apelin-13 reduces the degradation of nucleus pulposus extracellular matrix, promotes proliferation, and reduces the levels of apoptosis and inflammation. In addition, the Apelin-13/APJ system increases the expression of PI3K and AKT and activates the PI3K/AKT signaling pathway. CONCLUSIONS: Apelin-13/APJ system activates PI3K/AKT signaling pathway activity, reduces the degradation of nucleus pulposus extracellular matrix, promotes proliferation, and reduces the level of apoptosis and inflammation, thus delaying the degeneration of the intervertebral disc.

Effects of Vitamin B12 on postoperative cognitive dysfunction induced by isoflurane anesthesia in rats.

OBJECTIVE: Postoperative cognitive dysfunction is a clinical syndrome associated with cognitive decline in patients after anesthesia. This study aimed to investigate the effect of VB12 (Vitamin B12), a kind of necessary micronutrients promoting the growth and development of the nervous system, on cognitive dysfunction induced by isoflurane anesthesia. MATERIALS AND METHODS: Eighteen-month-old rats were exposed to or were not exposed to 1.4% isoflurane for 2 h. Two hours before isoflurane exposure, rats in groups with VB12 were injected intramuscularly with VB12 at 10 or 20 µg. Two weeks later, rats were subjected to Barnes maze and Morris water maze. RESULTS: Rats exposed to isoflurane had significant impairments in long-term spatial memory assessed by Barnes maze. There was no statistical significance in the percentage of swimming time and path length in the Morris water maze tests among five groups, suggesting that isoflurane may not impair the recall of learned information in rats. Isoflurane increased the expression of interleukin 1ß (IL-1ß) and activated caspase 3 in the hippocampus, but not cortex of the rats. The increase of IL-1ß and activated caspase 3 was attenuated by VB12. However, isoflurane did not change the amount of tumor necrosis factor-α (TNF-α) and ß-amyloid peptide in the hippocampus and cerebral cortex. CONCLUSIONS: VB12 can attenuate cognitive dysfunction induced by isoflurane anesthesia. At the same time, IL-1ß may play an important role in this isoflurane effect.

[The reliability of electrochemical enzyme-linked immunosorbent assay for detection of dentin sialophosphoprotein in gingival crevicular fluid].

OBJECTIVE: To investigate the reliability of electrochemical enzyme-linked immunosorbent assay(ELISA)for the detection of dentin sialophosphoprotein(DSPP)in gingival crevicular fluid(GCF)of orthodontic patients. METHODS: GCF were collected from the orthodontic patients, and then the amount of DSPP in GCF were detected by electrochemical ELISA and spectroscopic ELISA respectively. The difference between the results of two methods were analyzed. RESULTS: In electrochemical ELISA, the second order derivative linear sweep voltammetric peak current was linear with DSPP concentration in the range from 0.25-800.00 ng/L. It was found that the detection limit of the electrochemical method(0.25 ng/L)was much lower than that of the spectroscopic method. The paired-samples rank sum test showed no significant difference between the DSPP concentrations in human GCF samples measured by spectroscopic ELISA procedure and those measured by electrochemical ELISA procedure(P=0.063). CONCLUSIONS: Electrochemical ELISA is a viable way of detecting DSPP in GCF with higher sensitivity than spectroscopic ELISA.

DVP parametric imaging for characterizing ovarian masses in contrast-enhanced ultrasound.

AIM: To evaluate whether parametric imaging with contrast-enhanced ultrasound is an approach capable of for the differential diagnosis of ovarian masses. MATERIALS AND METHODS: The authors analysed 50 cases of ovarian masses by routine ultrasound and contrast-enhanced ultrasound with a new dedicated parametric image processing software-Sonoliver. The angiogenesis and blood perfusion mode on a digital video recorder were recorded and the morphological characteristics of time-intensity curve (TIC) and dynamic vascular pattern (DVP) curve were subsequently described. The quantity factor, including time to peak (TTP), maximum intensity (IMAX), rise time, (RT), mean transit time (mTT), generated by Sonoliver software were compared in both histological gradings. RESULTS: There were 24 cases (86%) displaying mainly hypo-enhanced with blue imaging in those with benign masses and 15 cases (68%) displaying mainly hyper-enhanced imaging with red in those with malignant masses. The difference was statistically significant (p < 0.05). DVP curves were unipolar below the baseline in 23 cases (82%) of benign masses and unipolar above the baseline in 15 cases (68%) of malignant masses. IMAX, TTP, and mTT were all significantly higher in those with malignant masses than those with benign ones (all p < 0.05), but, no statistical difference in the RT between the two groups was found (p > 0.05). CONCLUSIONS: According to the results, DVP parametric imaging is a new approach capable of differential diagnoses of overian masses with contrast-enhanced ultrasound.

Correlation between the genetic polymorphism of ORMDL3 gene and asthma risk: a meta-analysis.

While increasing scientific evidence suggests that the ORMDL3 rs7216389 polymorphism may contribute to a higher susceptibility to asthma, many of the current studies have yielded inconclusive results. This meta-analysis aimed to assess the association between the ORMDL3 rs7216389 polymorphism and the risk of asthma. An extensive literature search for relevant studies was conducted in PubMed, Embase, the Web of Science, the Cochrane Library, Chinese National Knowledge Infrastructure, and Google Scholar. This meta-analysis was performed using the STATA 12.0 software. Crude odds ratios (OR) and their 95% confidence intervals (CI) were calculated. Thirteen studies were included with a total of 14,851 subjects, comprised of 6739 patients with asthma and 8112 healthy controls. Our meta-analysis results revealed that the ORMDL3 rs7216389 polymorphism may be associated with an increased risk of asthma (allele model: OR = 1.39, 95%CI = 1.27-1.52, P < 0.001; dominant model: OR = 1.46, 95%CI = 1.31-1.62, P < 0.001; recessive model: OR = 1.57, 95%CI = 1.37-1.81, P < 0.001; homozygous model: OR = 1.58, 95%CI = 1.32-1.90, P < 0.001; heterozygous model: OR = 1.54, 95%CI = 1.30-1.82, P < 0.001). We also found significant associations in our subgroup analyses based on ethnicity and type of asthma. However, in our subgroup analysis based on sources of controls, an association was found in the population-based case-control subgroup but not in the hospital-based case-control subgroup. This meta-analysis indicates that ORMDL3 rs7216389 may contribute to increasing susceptibility to asthma.

Combination of a novel photosensitizer DTPP with 650 nm laser results in efficient apoptosis, arresting cell cycle and cytoskeleton protein changes in lung cancer A549 cells.

Photodynamic therapy (PDT) using photosensitized reaction to produce cytotoxicity was used for cancer therapy in recent years. To study the effectiveness of PDT mediated by a novel photosensitizer (PS), DTPP 5-(4'-(2″-dicarboxymethylamino)acetamidophenyl)-10, 15, 20-triphenylporphyrin, on lung cancer A549 cell lines in vitro, DTPP was employed in different concentrations (2, 4, 6, 8, 10, 12, 15, 20, 25, and 30 µg/ml) and combined with 650 nm laser of different power densities (0.6, 1.2, 2.4, 4.8, 7.2, and 9.6 J/cm(2)) that resulted in obvious inhibition of cell proliferation and apoptosis. Results showed that cell survival rates have a dependent relationship with time and PS concentrations and no significant cytotoxicity was induced by DTPP itself. Apoptosis and cell cycle S arrest were observed; cytoskeleton morphologic observation revealed collapse, sparkling, and shrunken shapes. Apoptosis-related protein caspase-3 overexpression was detected while caspase-9, bcl-2, and cytoskeleton protein beta-catenin were in low levels of expression than the control. Cleavage of beta-catenin by caspase-3 or other proteases from the lysosome might be the main reason for the cytoskeleton collapse as beta-tubulin and actin were at a stable level 12 h after PDT. This paper gives a better understanding of the effectiveness of DTPP-mediated PDT in lung cancer A549 cells both with regard to dosimetry and apoptosis changes.

Combination of a novel photosensitizer DTPP with 650 nm laser results in efficient apoptosis and cytoskeleton collapse in breast cancer MCF-7 cells.

Luminal A type breast cancer was suitable for Photodynamic therapy (PDT) as its strong adhesion ability, low malignancy and easily being exposed to laser. To examine the novel photosensitizer agent 5-5-(4-N, N-diacetoxylphenyl-10, 15, 20-tetraphenylporphyrin)(DTPP) mediate PDT in breast cancer cell, Luminal A type breast cancer MCF-7 cells were used in this study, various concentrations of DTPP (0, 2, 4, 6, 8, 10, 12, 15, 20, 25, 30 µg/mL) and different time intervals (0, 0.5, 1, 2, 4, 6, 8 min) of laser exposure at 650 nm wavelength (power of 20 mW) were tested in PDT. The survival rates of MCF-7 cells were measured using a sensitive cell proliferation assay (MTT) to establish optimal semilethal dose and optimal time exposure, a further study of effects on cytoskeleton and apoptosis were also performed. Cell cycle and apoptosis variation were assayed by flow cytometry. Microtubule, microfilament, and nuclei were observed using laser scanning confocal microscopy. Oncoproteins Bcl-2, beta-tubulin, and beta-catenin were detected by means of electrophoresis. The novel DTPP showed an efficient growth inhibition of MCF-7 during PDT, effective combinations in MCF-7 cells were shown to be 4 µg mL(-1) PS irradiated for 8 min at least or 15 µg mL(-1) irradiated for 2 min at least. Microtubule, microfilament, and nucleus staining demonstrated that cytoskeletal collapse occurs at 0.5 h after PDT. Bcl-2 and skeleton adhesion proteins beta-catenin were reduced in the level of expression; whereas, skeleton proteins beta-tubulin and actin maintained similar levels of expression 12 h after PDT. These results provided a better understanding of DTPP-PDT in MCF-7 cells.

Exercise induces mitochondrial biogenesis after brain ischemia in rats.

Stroke is a major cause of death worldwide. Previous studies have suggested both exercise and mitochondrial biogenesis contribute to improved post-ischemic recovery of brain function. However, the exact mechanism underlying this effect is unclear. On the other hand, the benefit of exercise-induced mitochondrial biogenesis in brain has been confirmed. In this study, we attempted to determine whether treadmill exercise induces functional improvement through regulation of mitochondrial biogenesis after brain ischemia. We subjected adult male rats to ischemia, followed by either treadmill exercise or non-exercise and analyzed the effect of exercise on the amount of mitochondrial DNA (mtDNA), expression of mitochondrial biogenesis factors, and mitochondrial protein. In the ischemia-exercise group, only peroxisome proliferator activated receptor coactivator-1 (PGC-1) expression was increased significantly after 3 days of treadmill training. However, after 7 days of training, the levels of mtDNA, nuclear respiratory factor 1, NRF-1, mitochondrial transcription factor A, TFAM, and the mitochondrial protein cytochrome C oxidase subunit IV (COXIV) and heat shock protein-60 (HSP60) also increased above levels observed in non-exercised ischemic animals. These changes followed with significant changes in behavioral scores and cerebral infarct volume. The results indicate that exercise can promote mitochondrial biogenesis after ischemic injury, which may serve as a novel component of exercise-induced repair mechanisms of the brain. Understanding the molecular basis for exercise-induced neuroprotection may be beneficial in the development of therapeutic approaches for brain recovery from the ischemic injury. Based upon our findings, stimulation or enhancement of mitochondrial biogenesis may prove a novel neuroprotective strategy in the future.

The role of T-helper 17 (Th17) cells in patients with medulloblastoma.

As a new member of the CD4(+) effector T-cell family, T-helper 17 (Th17) cells, have emerged as an important mediator in inflammatory and autoimmune diseases. Th17 cells preferentially produce interleukin (IL)-17A, IL-17F, IL-21, IL-22, and IL-26 in humans. Recent studies suggest a potential role for Th17 cells in tumour development. The current study was designed to investigate the possible involvement of Th17 cells in the brain tumour medulloblastoma. Compared with 17 healthy volunteers, 23 patients with medulloblastoma had a higher proportion of Th17 cells in their peripheral blood. Increased populations of Th17 cells were also present in medulloblastoma-infiltrating T-cells. Furthermore, the mRNA levels for Th17-related factors (IL-17, IL-23 and retinoid orphan nuclear receptor) in tumour tissues and the serum concentrations of IL-17 and IL-23 protein were significantly increased in patients with medulloblastoma. The results indicate that Th17 cells may contribute to medulloblastoma pathogenesis.

Removal efficiency of high-concentration H2S in a pilot-scale biotrickling filter.

A pilot-scale biotrickling filter (BTF) packed with polyurethane (PU) foam was installed at one pharmaceutical factory in Zhejiang Province to study the removal of high-concentration H2S from water treatment plant. Experiments were performed at different empty bed residence times (EBRTs), H2S input load, ratio of liquid flow rate to gas inlet rate (L/G) and sulfate concentration in recirculating liquid to examine their effects on the performance of the BTF. The performance of this bioreactor was monitored continuously over a period of 56 days. After the start-up within 8 days, H2S removal efficiency remained between 90% and 100% with inlet concentration fluctuating from 238 to 590 mg m(-3). H2S removal efficiency was consistently greater than 90%, even at a short EBRT of 9 s and inlet H2S load higher than 187 g m(-3) h(-1). Profiles over the height of the reactor indicated that H2S removal took place mostly in the first section of the column. The performance of BTF could be maintained at high and stable levels when L/G was below 0.005 and sulfate concentration down to 28 g l(-1). The results led to the conclusion that BTF is the optimal choice for treating high-concentration H2S.

An Acupuncture-like Quantitative Mechanical Stimulator.

A stimulator that analogs the needle puncture has been designed to deliver quantitative mechanical stimulus to a small area of muscle. A friction coupler is designed to transmit the driving force from motor to a needle which is used to deliver stimulus. Rotation of the needle may be stopped but the friction will be maintained between the needle and the tissue when this friction moment comes to the driving moment of the coupler. Experiments were done on 6 hindlimb muscles in 2 cats and the results show the value of the stimulator in probing the mechanisms of acupuncture.

Effect of resveratrol on peritoneal macrophages in rats with severe acute pancreatitis.

OBJECTIVE: The literature on resveratrol in severe acute pancreatitis (SAP) is limited though it has been widely studied in infections and trauma. The aim of this study was to investigate the inhibitory effect of resveratrol on inflammatory responses in a rat model of SAP. METHODS: Male Sprague-Dawley (SD) rats were randomly divided into 3 groups: SAP group, resveratrol group and control group. 4.0% sodium taurocholate was injected into the pancreatic duct to induce SAP. In the resveratrol group, resveratrol (10 mg/kg) was injected through penal vein 5 min after SAP was induced. The peritoneal macrophages of the rats were collected 3, 6 and 12 h after stimulus and then incubated for 24 h. The expression of nuclear factor kappa B (NF-kappaB) and inducible nitric oxide synthase (iNOS) in peritoneal macrophages was measured. The levels of tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1) and nitric oxide (NO) in culture medium of peritoneal macrophages and serum of rats were evaluated. RESULTS: Histological examination of pancreas indicated that the damage in the SAP group was more severe than that in the resveratrol group. The expression of NF-kappaB and iNOS in peritoneal macrophages was significantly higher in the SAP group than in the resveratrol group. The concentrations of TNF-alpha, IL-1 and NO in culture medium and serum were significantly elevated in the SAP group when compared with the resveratrol group. CONCLUSIONS: The inhibiting effect on the inflammatory response and the decreased expression of TNF-alpha, IL-1 and NO in peritoneal macrophages suggest resveratrol as a novel anti-inflammatory agent for reducing the severity of SAP.

Remodelling of zero-stress state of small intestine in streptozotocin-induced diabetic rats. Effect of gliclazide.

BACKGROUND: Biomechanical properties in terms of residual strains in diabetic small intestine have not been studied. Furthermore, no data have been reported on affect of gliclazide on gastrointestinal complications of diabetes. AIMS: To determine remodelling of zero-stress state of small intestine in streptozotocin-induced diabetic rats and effect of gliclazide treatment. MATERIALS: Morphological properties and residual strains were studied in duodenum, jejunum and ileum obtained from diabetic rats, gliclazide-treated diabetic rats and normal rats (n = 8 each group). METHODS: Diabetes was induced by single intraperitoneal injection of 65 mg/kg streptozotocin. Gliclazide (10 mg kg(-1) day(-1) was injected directly into stomach lumen by intragastric gavage twice daily. Experimental period was 35 days. To approach no-load state; intestinal segments were surgically excised and cut transversely into short ring-shaped segments. Each ring was cut radially to obtain geometry of zero-stress state. Circumferential length, the wall thickness and opening angle were measured from digital images of each specimen and residual strains were computed. RESULTS: Blood glucose level of diabetic group (approximately 20 mmol/l) was consistently higher than that in normal group (approximately 4 mmol/l) after induction of diabetes (p < 0.001). Gliclazide lowered average blood glucose level to between 10 and 15 mmol/l (p < 0.001). Plasma insulin levels of both diabetic groups (average between 10 and 15 pmol/l) were significantly lower than those in normal group (average approximately 18 pmol/l, p < 0.05). Wet weight per unit length and wall thickness of duodenum, jejunum and ileum were significantly higher in Diabetes group than those in Normal group (p < 0.05). Opening angle and absolute value of residual strain were significantly smaller in duodenum and larger in jejunum and ileum in Diabetes group than in Normal group (p < 0.001). Gliclazide treatment partly restored these changes (p < 0.05). CONCLUSIONS: Diabetes induced morphometric and biomechanical remodelling in intestine. Gliclazide partly restored these changes.

[Detection of telomerase activity in the blood of patients with lung cancer].

BACKGROUND: To study the telomerase activity in blood cancer cells by TRAP for monitoring tumor metastasis in blood. METHODS: Twenty-five patients with lung cancer surgically treated and 35 patients before chemotherapy were determined for telomerase activity of cancer cells in the blood by TRAP, and 30 patients with non-tumor diseases as control. RESULTS: In the operative group,13 patients(52%) showed telomerase activity in pulmonary artery blood during operation, which was much higher than that of peripheral blood before operation (24%,P<0.05). Telomerase positive rate was significantly higher in stage III to IV (64%) than that in stage I to II (30%,P<0.05).In the peripheral blood of patients with non-tumor diseases, telomerase was negative. CONCLUSIONS: Telomerase activity may be an indicator for detecting lung cancer cells in peripheral blood as well as tumor metastasis and relapse.

[Analysis of circulating lung cancer cells in the peripheral blood in patients with lung cancer by flow cytometry].

BACKGROUND: To analyze circulating lung cancer cells in the peripheral blood in patients with lung cancer by flow cytometry (FCM). METHODS: The monocyte fraction in peripheral blood was isolated by Ficoll-Hypaque gradient centrifugation. The cells obtained were labeled with antibodies against CD45, cytokeratin (CK) and antigen (2F7/S5A). The CD45(-) CK(+) 2F7/S5A(+) cells were analyzed by FCM. RESULTS: Fifty cases out of 165 patients with lung cancer (30.30%) were found to have cancer cells in the peripheral blood. Positive rate in non-small cell lung cancer was 30.67%(45/150) and that in small cell lung cancer was 33.33%(5/15) respectively. Meanwhile, there was distinct correlation between detective rate of cancer cells in the peripheral blood and pathological stage(P<0.05). CONCLUSIONS: Examination of lung cancer presented in the peripheral blood by FCM might be helpful for staging and finding metastatic potential of lung cancer.

[An establishment of murine drug-resistant cell line transfected with human MDR-1 gene.].

BACKGROUND: To investigate the relationship between MDR-1 gene expression and drug resistance in lung cancer cells. METHODS: The multidrug resistant cell line (3LL-MDR-1) was established by transfecting human MDR-1 gene expressing vector into a murine Lewis lung cancer cell line (3LL) . Drug resistance and the effect of valapamil (VLP) on the resistance were evaluated by MTT assay. The expression of MDR-1 gene product , P-gp , was measured immunohistochemically. The influx and efflux of Rhodamine 123 was tested with flow cytometry. RESULTS: The MDR cell line expressing P-gp was established , which exhibited a typical drug resistance to vincristine (VCR) , vindesin (VDS) , etoposide (VP-16) , mitomycin (MMC) , taxol and navelbine (NOR) . Valapamil was able to reverse the resistance of the gene-transfected cells and the reversion was dose-dependent. Flow cytometric analysis showed that the resistant cells had much higher ability to export Rhodamine 123 than the parent cells did. The expression of P-gp protein was visualized immunohistochemically. CONCLUSIONS: The results indicate that drug resistance in lung cancer cells is closely related to the MDR-1 gene expression.