Stable reversal of multidrug resistance in A549/DDP cells by shRNA targeting MRP1 gene

AIM: To reverse multidrug resistance (MDR) of A549/DDP cells with short hairpin RNA (shRNA) expression vectors. METHODS: Two multidrug resistance-associated protein 1( MRP1 ) gene-specific shRNA expression plasmids pSilencer 2.1-U6 neo-MRP1 were constructed and introduced into A549/DDP cells. MRP1 mRNA was assayed by real-time fluorescent quantitative PCR. The MRP1 function was determined by rhodamine 123(Rho123) retention and the protein expression of MRP1 was detected by immunofluorescent staining. The viability of A549/DDP cells was evaluated by MTT method. RESULTS: MRP1 shRNA expression plasmids were successfully constructed. The expression of MRP1 at mRNA and protein levels was significantly decreased after sh-MRP1-2.1-1 and sh-MRP1-2.1-2 were transfected into A549/DDP cells. The intracellular accumulation of Rho123 significantly increased from(16.93±0.58)% to (89.02±0.59)% and (82.56±1.37)%. IC₅₀ of cisplatin were decreased from (101.45±0.64) μmol/L to (38.06±0.05) μmol/L and (53.72±0.36) μmol/L. IC₅₀ of 5-fluorouracil were decreased from (263.20±2.00) μmol/L to (98.82±1.16) μmol/L and (141.81±0.49) μmol/L. CONCLUSION: The shRNA expression plasmid pSilencer 2.1-U6 neo-MRP1 can stably and permanently inhibit MRP1 gene. The sensitivity of A549/DDP cells to drug is reversed.     

Effect of zacopride on angiotensin Ⅱ-induced myocardial fibrosis

AIM:To investigate the effect of inwardly rectifying potassium channel (I_K1) agonist zacopride (Zac) on angiotensin Ⅱ (Ang Ⅱ)-induced viability and apoptosis of cardiac fibroblasts (CFb) and to explore the underlying anti-fibrosis mechanism.METHODS:The ventricular fibroblasts from neonatal SD rats were isolated and cultured by tissue digestion and differential adherence methods. The model of rat cardiac fibroblast activation induced by angiotensin Ⅱ was established. The CFb were randomly divided into control group, Ang Ⅱ model group, Ang Ⅱ+Zac group, Ang Ⅱ+Zac+BaCl₂ group, AngⅡ+Zac+chloroquine group and Ang Ⅱ+captopril group. CCK-8 assay was used to detect the effect of Zac on the viability of CFb. The amount of collagen I and collagen Ⅲ secreted by CFb was determined by ELISA. The apoptosis of the CFb was analyzed by flow cytometry. The protein expression of Kir2.1 was determined by Western blot. RESULTS:Compared with the control group, the viability and collagen synthesis of the CFb were significantly increased, along with decreased Kir2.1 expression (P<0.05). Compared with the Ang Ⅱ model group, Zac treatment inhibited the viability and collagen synthesis of the CFb, induced apoptosis and up-regulated Kir2.1 expression (P<0.05). I_K1 blockers BaCl₂ and chloroquine reversed the effect of Zac. CONCLUSION:By enhancing I_K1 (Kir2.1) expression, Zac attenuates Ang Ⅱ-induced ventricular fibrosis, in response to the inhibition of cell viability and induction of apoptosis.     

HAPLN1 induces resistance to MTX in human colorectal cancer HT-29 cells though IKK/p65 pathway

AIM:To investigate the changes of hyaluronan and proteoglycan link protein 1 (HAPLN1) expression before and after resistance to methotrexate (MTX) in human colorectal cancer HT-29 cells and its effect on this drug resistance, and to explore the molecular mechanism in the process. METHODS:The drug-resistant HT-29/MTX cells were established by stepwise exposure of the cells to MTX, and then the HT-29/MTX cells were stably transfected with specific shRNA interference plasmid vectors targeting HAPLN1 and multidrug resistance-associated protein 2 (MRP2). The mRNA expression levels of HAPLN1 and MRP2 were measured by RT-PCR. CCK-8 assay was used to detect the viability of HT-29/MTX cells. The apoptosis rate was analyzed by flow cytometry. The protein levels of HAPLN1, MRP2, IκB kinase (IKK) α/β, p-IKKα/β (Ser176/Ser177), p65 and p-p65 (Ser536) were determined by Western blot. RESULTS:The HT-29/MTX cells had significantly higher mRNA and protein levels of HAPLN1 and MRP2 than HT-29 cells (P<0.05) with resistant factor of 463.756. HAPLN1 and MRP2 gene silencing significantly increased the cytotoxicity and apoptosis of HT-29/MTX cells induced by MTX (P<0.05). The IC₅₀ value was decreased from 15.304 μmol/L to 6.119 μmol/L and 7.801 μmol/L, respectively, and their reversal folds were 2.501 and 1.962, respectively. Silencing of HAPLN1 and IKK inhibitor IKK16 inhibited the phosphorylation of IKKα/β and p65 (P<0.05), and down-regulated the protein level of MRP2 in the HT-29/MTX cells (P<0.05). However, IKK16 did not affect the protein level of HAPLN1 in the HT-29/MTX cells.CONCLUSION:Knock-down of HAPLN1 gene expression reverses the resistance to MTX in human colorectal cancer HT-29/MTX cells possibly by blocking the IKK/p65 signaling pathway and thus down-regulating the expression of MRP2.     

Effects of ATP-competitive GSK-3 inhibitor on multidrug resistance of human esophageal squamous-cell carcinoma cells

AIM: To study the changes and correlations of β-catenin, multidrug resistance-associated protein 2 (MRP2), P-glycoprotein (P-gp), Bcl-2 and the free ATP level in esophageal squamous-cell carcinoma (ESCC) cell line EC-109 induced by ATP-competitive glycogen synthase kinase(GSK-3) inhibitor 6-bromoindirubin-3'-oxime (BIO). METHODS: The methods of flow cytometry, immunofluorescence, cytochemistry and ATP assay were used to study the expression levels of MRP2, P-gp, β-catenin and Bcl-2, the efflux capability of ATP-binding cassette (ABC) transporters, and the free ATP level in ESCC cells. RESULTS: After induced by BIO, up-regulation of β-catenin and Bcl-2 expression in cytoplasm and accumulation of β-catenin in nucleus were found in ESCC cells. The expression of MRP2 was up-regulated in cytoplasm and cell membrane. On the contrary, the expression of P-gp was down-regulated in cytoplasm and cell membrane. The free ATP level and the efflux capability of ABC transporters increased in ESCC cells. CONCLUSION: The multidrug resistance of ESCC cells in enhanced by BIO treatment.     

PI3K/Akt/GSK-3β pathway mediates ABC transporter regulating multidrug resistance in human colon cancer HCT-15 cells

AIM: To investigate whether the PI3K/Akt signaling pathway regulates the expression of ABC transporter through the downstream glycogen synthase kinase-3β (GSK-3β) pathway and participates in the multidurg resistance of colorectal cancer (CRC) HCT-15 cells. METHODS: Colorectal cancer HCT-15 cells were cultured and then treated with GSK-3β inhibitor (HY-19807) and PI3K/Akt pathway inhibitor (HY-13898), respectively. The median inhibitory concentration (IC₅₀) of oxaliplatin for HCT-15 cells in each group was detected by CCK-8 assay, the inhibition rate and resistance index were also calculated. The protein levels of Akt, p-Akt, GSK-3β, p-GSK3β-Ser9 and ABC transporters P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP-2) in the HCT-15 cells were determined by Western blot. The mRNA expression of ABC transporter in the HCT-15 cells was detected by RT-qPCR. The cell cycle distributions were analyzed by flow cytometry assasy. RESULTS: After GSK-3β inhibitor HY-19807 was used in the HCT-15 cells, the median inhibitory concentration of oxaliplatin was significantly increased, the protein levels of p-GSK3β-Ser9, P-gp and MRP-2 were up-regulated compared with control group (P<0.05), the changes of Akt and p-Akt were not obvious compared with control group (P>0.05). The results of RT-qPCR also showed that the mRNA levels of ABCB1 and ABCC2 were increased (P<0.01). Meanwhile, analysis of the cell cycle distribution showed that GSK-3β inhibitor HY-19807 promoted HCT-15 cell transition from G₁ phase to S phase, and cell proliferation was vigorous. After the PI3K/Akt pathway inhibitor HY-13898 was applied to HCT-15 cells, the IC₅₀ of oxaliplatin was decreased compared with control group (P<0.05). Moreover, the protein levels of p-Akt, p-GSK3β-Ser9, P-gp and MRP-2 were down-regulated (P<0.01). RT-qPCR results also showed that the mRNA expression of ABCB1 and ABCC2 was decreased (P<0.01). At the same time, G₁ phase was prolonged, which inhibited cell transition from G₁ phase to S phase, and inhibited cell proliferation. The protein expression of total GSK-3β was consistent in each group. CONCLUSION: The PI3K/Akt signaling pathway is involved in the proliferation and multidrug resistance of colorectal cancer HCT-15 cells by regulating the phosphorylation of GSK-3β and changing the expression of ABC transporter.     

Reversing effect of naringin on cisplatin resistance in human lung cancer A549/DDP cells

AIM: To investigate the effect of naringin (NRG) on cisplatin (DDP) resistance in human lung cancer A549/DDP cells and its possible mechanism. METHODS: A549/DDP cells were cultured in vitro and treated with NRG and/or DDP at different concentrations for 24 h, and then the cell viability were measured by CCK-8 assay. The combination index (CI) of NRG and DDP were analyzed by Chou-Talalay method. The apoptosis rate was analyzed by flow cytometry. Western blot was performed to detect the protein levels of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), p-Akt, CXC chemokine receptor 4 (CXCR4), cleaved caspase-3, Bcl-2 and Bax.RESULTS: The protein levels of P-gp, MRP1, p-Akt and CXCR4 in the A549/DDP cells were higher than those in the A549 cells (P<0.05). The cell viability was remarkably reduced in a dose-dependent manner when A549/DDP cells were exposed to NRG and/or DDP (P<0.05), and the IC₅₀ values of NRG and DDP were 36.92 μmol/L and 129.77 μmol/L, respectively. When the inhibition rate exceeded 15%, NRG in combination with DDP produced a synergistic effect (CI<1). Combination treatment with NRG and DDP significantly induced apoptosis (P<0.05), up-regulated the protein levels of cleaved caspase-3 and Bax, and down-regulated the protein level of Bcl-2 (P<0.05). Meanwhile, NRG remarkably down-regulated the protein levels of P-gp, MRP1, p-Akt and CXCR4 in a dose-dependent manner (P<0.05). CONCLUSION: NRG may enhance the sensibility of A549/DDP cells to DDP most likely via up-regulating the protein level of Bax and down-regulating the protein levels of Bcl-2, P-gp, MRP1, p-Akt and CXCR4.     

Zacopride attenuates pressure overload-induced ventricular remodeling in rats

AIM:To investigate the protective effect of zacopride (ZAC) on the pressure-overload left ventricular remodeling in the rats induced by coarctation of abdominal aorta. METHODS:Male Sprague-Dawley (SD) rats with pressure overload were induced by the coarctation of abdominal aorta. The model rats were intraperitoneally administered with ZAC, chloroquine (Chlor), and zacopride+chlorquine (ZAC+Chlor). The study duration was 8 weeks. The cardiac structure and function were assessed by echocardiography. The heart weight/body weight (HW/BW) ratio and the left ventricular weight/body weight (LVW/BW) ratio were calculated. The changes of structure and shape in myocardial tissue were observed with HE staining. The ultrastructure of the myocytes was observed under transmission electron microscope. The inward rectifier potassium channel (I_K1) protein expression was determined by Western blot. The mRNA expression of Kir2.1 was detected by RT-PCR. RESULTS:Compared with vehicle group, ZAC improved cardiac function, as indicated by the decreased left ventricular end-diastolic dimension (LVEDD) and left ventricular end systolic dimension (LVESD) (P<0.05), and the increased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) (P<0.01). The HW/BW and LVW/BW ratios were significantly decreased, and the cross-sectional area of the cardiomyocytes was significantly less in ZAC group than that in vehicle group (P<0.01). The ultrastructure of the myocytes was significantly improved. Chlor blocked the protective effect of zacopride on the pressure-overload left ventricular remodeling. The protein level of I_K1 and mRNA expression of Kir2.1 in the cardiac tissues in ZAC group were significantly increased compared with vehicle group (P<0.01). CONCLUSION:I_K1 agonist ZAC significantly attenuates pressure overload-induced ventricular remodeling in rats.     

Roles of the Kv1.2, Kv1.5, Kv2.1 potassium channels in hypoxia pulmonary vasoconstriction

AIM: To determine the role of Kv1.2, Kv1.5, Kv2.1 in the hypoxia pulmonary vasoconstriction (HPV). METHODS: Male Wistar rats were divided into two groups: normoxic group and hypoxic group. The single smooth muscle cell was obtained from pulmonary artery of Wistar rats with acute enzymatic digestion method. The conventional whole-cell patch clamp technique was used to record the resting membrane potential (Em) and the potassium currents of voltage-gated potassium channel (IKv) in rat pulmonary arterial smooth muscle cells (PASMC). Intracellular application of Kv1.2/Kv1.5/Kv2.1 antibodies (1∶125) was conducted through the whole-cell patch clamp system. RESULTS: ① Em of PASMC was depolarized after 24 h hypoxia compared with that of control cells . IKv of PASMC was decreased after 24 h hypoxia, . ② The mixture of Kv1.2/Kv1.5/Kv2.1 antibodies depolarized Em and inhibited IKv in PASMC from normoxic rat, whereas the mixture of Kir2.1/Kir2.3/Kir4.1 antibodies had no effects on them. ③ The mixture of Kv1.2/Kv1.5/Kv2.1 antibodies and the mixture of Kir2.1/Kir2.3/Kir4.1 antibodies had no effects on IKv and Em from rats hypoxic for 24 h. CONCLUSION: Kv1.2, Kv1.5, Kv2.1 might be oxygen sensitive potassium channels which mediated HPV.     

Effect of sorcin expression on sensitivity of human glioma cells to cisplatin

AIM：To investigate the effect of sorcin expression on the sensitivity of human glioma cells to cisplatin. METHODS：pSilencerTM 3.1-H1-sorcin siRNA recombinant plasmid was constructed, and transfected into human glioma U251 cells. RT-PCR and Western blotting were used to analyze the expression of sorcin at mRNA and protein levels after transfection. The viability of U251 cells was measured by MTT assay. The protein expression of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) in U251 cells was detected by Western blotting. RESULTS：The plasmid pSilencerTM 3.1-H1-sorcin siRNA was successfully constructed, and was confirmed by restriction enzyme digestion and sequence analysis. The expression of sorcin at mRNA and protein levels was significantly decreased after sorcin siRNA was transfected into U251 cells (P<0.05). Inhibition of sorcin expression significantly decreased the viability of U251 cells treated with cisplatin (P<0.05), and the expression of P-gp and MRP1 proteins was also inhibited (P<0.05). CONCLUSION：Inhibition of sorcin expression increases the sensitivity of U251 cells to cisplatin by decreasing the expression of resistance-related proteins P-gp and MRP1, suggesting that sorcin may be associated with the resistance of glioma cells to cisplatin.     

Effects of ginsenoside Rg1 of Panax notoginseng on brain tissue injury and Nrf2/HO-1 signal pathway after cerebral ischemia/reperfusion in mice

AIM:To observe the effects of ginsenoside Rg1 of Panax notoginseng on brain tissue injury after mouse cerebral ischemia/reperfusion(I/R), and to explore the mechanisms involving nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) signal pathway. METHODS:C57BL/6 mice were randomly divided into sham group, cerebral I/R group, ginsenoside Rg1+cerebral I/R group and edaravone+cerebral I/R group. Ginsenoside Rg1 was successively administered for 3 d. One hour after final administration, bilateral common carotid arteries were ligated to induce brain tissue injury for 20 min, and then reperfusion for 24 h. Edaravone, a drug for anti-oxidative stress injury in the treatment of ischemic cerebro-vascular disease, was used as a positive control. The brain tissues were obtained to determine the neural cellular pathology in hippocampal CA1 region. The mRNA expression of Nrf2 and HO-1 was detected by RT-PCR. The protein levels of Nrf2 in the nucleus and cytoplasm and HO-1 in the whole cells in the brain tissues were measured by Western blotting. RESULTS:After ischemia/reperfusion for 24 h, the pathological injury in the neural cells was obvious, and the cell survival rate decreased. Ginsenoside Rg1 and edaravone attenuated the neural cell injury, and significantly increased the cell survival rate. After ischemia/reperfusion for 24 h, the mRNA expression of Nrf2 and HO-1 significantly increased in the brain tissues. The protein levels of Nrf2 in the nucleus and cytoplasm in the brain tissues were increased, the nuclear translocaition rate and the protein expression of HO-1 also increased. Ginsenoside Rg1 and edaravone both decreased the protein levels of Nrf2 in the cytoplasm of the brain tissues, increased that in the nucleus, and also increased Nrf2 nuclear translocation rate and the protein expression of HO-1. The effect of edaravone was higher than that of ginsenoside Rg1, but they had no significant effect on the mRNA expression of Nrf2 in the brain tissues. CONCLUSION: Ginsenoside Rg1 has the effect of anti-brain tissue injury on cerebral ischemia/reperfusion. The mechanisms may be related to activating the Nrf2/HO-1 signal pathway, promoting Nrf2 synthesis and nuclear translocation, thus promoting the expression of downstream antioxidant protein HO-1.     

Expression of mic2/CD99 protein and their correlation with Eber-1/LMP-1 in Hodgkin and Reed-Sternberg cells of classical Hodgkin's lymphoma

AIM: To study the expression of mic2/CD99 protein and their correlation with Eber-1/LMP-1 in Hodgkin and Reed-Sternberg cells of classical Hodgkin's lymphoma. METHODS: Immunohistochemical staining, in situ hybrization and tissue microarry technique were used to detect the expressions of mic2/CD99 and Eber-1/LMP-1 of H/RS cells in 43 cases of cHL and 16 cases of NHL. RESULTS: The positive rate of CD99 protein expression in 43 cases of cHL was 2.3％ (1/43), mic2 was 55.8％ (24/43), LMP1 was 58.1％ (25/43) and Eber-1 was 53.5％ (23/43). The expressions of CD99 and mic2 in the NHL group were higher than those in cHL group (P<0.05). The expressions of LMP1 and Eber-1 in NHL group were lower than those in cHL group (P<0.05). The expression of mic2 was higher than CD99 in cHL group (P<0.05). There was no difference between the expression of Eber-1 and LMP1 in cHL group statistically (P>0.05). There was a negative correlation between the expression of CD99 protein and LMP1 in H/RS cells (P<0.05). No correlation was found between the expression of any other markers in H/RS cells and patients' sex (P>0.05). There was a significant correlation between the high expression of LMP1 and a low expression of CD99 in the young patients (P<0.05), but no correlation was found between the expression of mic2 and Eber-1 in young patients (P>0.05). CONCLUSION: There is a negative correlation between the expression of LMP1 and CD99 in Hodgkin and Reed-Sternberg cells of classical Hodgkin's lymphoma.     

Endoplasmic reticulum stress is involved in cardiomyocyte apoptosis induced by β1-adrenoceptor autoantibody

AIM: To investigate the role of endoplasmic reticulum (ES) stress in cardiomyocyte apoptosis induced by β₁-adrenoceptor autoantibody (β₁-AA). METHODS: The rat model of active immunization with the second extracellular loop of β₁-adrenoceptor was established, and SA-ELISA was applied to detect the level of β₁-AA in serum of actively immunized rats. The apoptosis of cardiomyocytes was detected by TUNEL staining, and the protein expression levels of glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and caspase-12 in rat heart tissues were determined by Western blot and immunohistochemistry. After purified β₁-AA obtained by affinity chromatography was used to treat H9c2 myocardial cells, the cell viability was measured by CCK-8 assay and the apoptosis was analyzed by flow cytometry with Annexin V-FITC/PI double staining. The H9c2 cells were treated with ER stress inhibitor 4-phenoxybutyric acid (4-PBA) before interfered with β₁-AA, and the changes of cell viability and apoptosis were determined by CCK-8 assay and flow cytometry. RESULTS: Compared with vehicle group, the level of β₁-AA in the serum of rats was significantly increased after active immunization for 2 weeks and further rised in 8 weeks, and increased apoptosis was observed in cardiomyocytes after active immunization for 2 weeks, lasting till 8 weeks. Compared with vehicle group, the protein expression of GRP78, CHOP and caspase-12 increased after active immunization for 4 weeks and 8 weeks. Continuous reduction of cell viability and increased apoptosis of H9c2 cells were induced by β₁-AA. ER stress inhibitor 4-PBA pretreatment in H9c2 cells reversed the increased apoptosis and decreased cell viability induced by β₁-AA, indicating that suppression of ER stress effectively reduced cardiomyocyte apoptosis. CONCLUSION: β₁-AA induces increased apoptosis in cardiomyocytes by activating ER stress.     

Mutation of ATP-sensitive K+ channels and neonatal diabetes iDEND syndrome

Activating mutation in the KCNJ11 gene encoding Kir6.2 subunit of adenosine triphosphate (ATP)-sensitive potassium (K_ATP) channel gives rise to intermediate developmental delay, epilepsy and neonatal diabetes (iDEND) syndrome, a rare hereditary endocrine metabolic disorder characterized by neonatal diabetes accompanied by developmental delay and muscle weakness, but no epilepsy. The Kir6.2 Val⁵⁹→Met⁵⁹ (V59M) activating mutation is the common cause of iDEND syndrome (>50%). Activating mutation causes iDEND syndrome by inhibiting normal closure of ATP-sensitive K⁺ channel, which leads to reduce insulin secretion. Most of such patients are more sensitive to sulfonylurea. High blood-brain barrier permeability and sulfonylurea receptor 1 (SUR1)-specific drugs are expected to become a major therapy.     

Expression of drug resistance related proteins in osteosarcoma and soft tissue sarcoma and its correlations with chemotherapy resistance

AIM: To explore the expression of four kinds of drug resistance related protein: P-glycoprotein (P-gp), glutathione-S-transferases-π (GST-π), lung resistance protein (LRP), multidrug resistance related protein (MRP) in osteosarcoma cell lines Saos2 and U2OS, and in osteosarcoma and soft tissue sarcoma tissues from 34 patients and their correlations with chemotherapy resistance.METHODS: The expression of protein was detected by flow cytometry (FCM).Chemotherapy resistance was analyzed by MTT assay.RESULTS: Expression of drug resistance related protein was lower in Saos2 cell line than that in U2OS cells.Chemotherapy sensitivity on adriamycin (ADM), cisplatinum (DDP), fluorouracilum (5-Fu), mitomycin (MMC), dacarbazine (DTIC), vincristine (VCR) was higher in Saos2 than those in U2OS cells.After the two cell lines were treated respectively with 1/5 50% inhibitory concentration (IC50) doses of ADM and DDP, the expression increasing range of GST-π was 33%-43%.The nonsensitive rate on ADM, DDP, 5-Fu, MMC, DTIC, VCR, methotrexate (MTX) in 34 patients were 41.18％, 17.65％, 47.06％, 50.00％, 76.47％, 61.76％ and 52.94％, respectively.The expression of P-gp, GST-π, LRP, MRP were 1.54, 2.58, 1.91 and 1.86, respectively.The correlation analysis showed that the expression of P-gp had positive correlation with resistance on ADM (r=0.485, P<0.01), the expression of GST-π had correlations with resistance on ADM, DDP, 5-Fu and MMC.The r value was 0.402, 0.458, 0.364 and 0.500,respectively.The corresponding value of P was <0.05, <0.01, <0.05 and <0.01,respectively.The observed expression of resistance related proteins was not significant difference between different gender, different age, different pathological type and different tumor size in osteosarcoma and soft tissue sarcoma patients (P>0.05).The expression of GST-π was increased dramatically in patients receiving chemotherapy preoperatively.The preoperative level of GST-π was higher in recurrent patients by follow-up survey than that in patients without recurrence (P<0.05).CONCLUSIONS: Individual difference was obvious in chemotherapy sensitivity and expression of resistance related proteins in different patients.Chemotherapy induced the upregulation of GST-π expression.Primary high expression of GST-π was the main mechanism of resistance in osteosarcoma and soft tissue sarcoma patients, and related with prognosis.     

Angiogenic effect of HIF-1α on extranodal nasal-type NK/T-cell lymphoma

AIM: To study the angiogenic effect of hypoxia inducible factor 1α(HIF-1α) and its significance on human extranodal nasal-type NK/T-cell lymphoma. METHODS: The protein levels of HIF-1α, vascular endothelial growth factor(VEGF) and VEGF receptor 2(VEGFR2) in human extranodal nasal-type NK/T-cell lymphoma were detected by immunohistochemistry. Microvessel density (MVD) of the tumor tissues was determined by labeling of microvessel endothelium with CD34 antibody. The correlation between the expression of HIF-1α, VEGF and VEGFR2 and MVD was analyzed with SPSS 13.0 statistical software. RESULTS: The positive expression of HIF-1α was observed in 39 cases (39/50, 78%) and the positive expression of VEGFR2 was 27 cases (27/50, 54%) of human extranodal nasal-type NK/T-cell lymphoma. A statistical difference of HIF-1α and VEGFR2 expression between tumor tissues and normal lymphocytes in lymph node was observed (P<0.05). In the tumor tissues, the co-expression of VEGF or VEGFR2 with HIF-1α was 72% and 64%, respectively, significantly higher than that without HIF-1α co-expression (P<0.05). The expression of HIF-1α, VEGFR and VEGFR2 was positively correlated with MVD of the tumor tissues (P<0.01). HIF-1α was expressed in all 15 cases of extranodal nasal-type NK/T-cell lymphoma with angiocentric infiltration.CONCLUSION: HIF-1α may promote angiogenesis of extranodal nasal-type NK/T-cell lymphoma through VEGF/VEGFR2 signaling pathway.     

Expression of eEF1A2 in hepatocellular carcinoma

AIM: To study the expression of eukaryotic elongation factor 1A2 (eEF1A2) in the hepatocellular carcinoma (HCC) tissues and the effects of eEF1A2 over-expression on the biological behaviors of the HCC cells. ME-THODS: The expression of eEF1A2 at mRNA and protein levels in the HCC tissues and matched liver tissues from 62 HCC patients, and 20 normal liver tissues were detected by the methods of real-time PCR and immunohistochemical staining, respectively. The mRNA and protein expression of eEF1A2 in the HCC cells was also determined by real-time PCR and Western blot, respectively. The lentivirus containing eEF1A2 gene was constructed, and was used to infect the HCC cells with low eEF1A2 expression. The expression of eEF1A2 at mRNA and protein levels in the infected cells was detected by real-time PCR and Western blot, respectively. The cell activity, cell cycle and mRNA expression of albumin were measured by MTT assay, DNA ploid analysis and real-time PCR, respectively.RESULTS: The mRNA expression levels and protein expression positive rates of eEF1A2 in the 62 cases of HCC tissues, were significantly higher than those of 62 matched liver tissues and 20 normal liver tissues (P<0.01). eEF1A2 mRNA and protein were highly expressed in SMMC-7721 cells and BEL-7402 cells, and expressed in SK-HEP-1 cells at low level. The expression of eEF1A2 at mRNA and protein levels in the SK-HEP-1 cells was significantly enhanced by infection of GV287-eEF1A2 expression lentivirus.Compared with negative control group (transfected with negative control lentivirus), the cell activity in eEF1A2 over-expression group (transfected with GV287-eEF1A2 expression lentivirus) was significantly enhanced, the mRNA expression of albumin was remarkably reduced, and the cells in G₀/G₁ phase were significantly decreased with increased percentage of the cells in S and G₂/M phases.CONCLUSION: eEF1A2 is selectively over-expressed in human HCC cancer tissues. eEF1A2 might be a putative oncoprotein in HCC. eEF1A2 over-expression has noticeable effects on the HCC cell proliferation enhancement, differentiation inhibition, and cell cycle acceleration through the G₀/G₁ phase to S phase and G₂/M phases.