Background and purpose:Remarkable advances have been made in cancer chemotherapy by developing new anticancer drugs and therapy strategies.However,multidrug resistance in human cancers remains a major clinical challenge for cancer treatment.Attempts in several clinical studies to reverse multidrug resistance protein (MDR) by using MDR modulators have not yet generated promising results.Our aim was to explored the mechanism of reversal of multidrug resistance in human leukemia K562 cells by PI3-K inhibitor.Methods:Trypanblue dye exclusion method was used to observe the drug sensitivity and the effect of LY294002 on the drug resistance.Western blot to analyze P-gp and p-Akt phenotypes,and flow cytometer was used to measure the intracellular drug accumulation. Results:K562/D induced by DNR was cross resistant to DNR,ADR,VCR and VP16 (Resistance Index:65,52,134 and 50 respectively).DNR induced over-expressions of P-gp and p-Akt in K562/D cells;LY294002 increased the intracellular drug accumulation,and then reversed the drug resistance to DNR,ADR,VCR and VPI6 in K562/D cells(Resistance Index:23,21,63 and 29 respectively),but not in the sensitive cells (K562/S).Conclusion:The multidrug resistance of K562/D cells can be induced by DNR which is related to the P-gp and p-Akt over-expressions, and LY294002 can reverse multidrug resistance in human leukemia cells in vitro via inhibits PI3-K/Akt pathway.

BACKGROUND AND OBJECTIVEc-Cbl and Cbl-b are two ubiquitous members of the Casitas B-lineage lymphoma (Cbl) family, which play important roles in the downregulation of epidermal growth factor receptor (EGFR) by acting as E3 ubiquitin ligases and multiadaptor proteins. This study investigated the expression of c-Cbl, Cbl-b, and EGFR in gastric carcinoma and its clinical significance.

METHODSThe expressions of c-Cbl, Cbl-b, and EGFR were detected by immunohistochemistry using tissue microarrays consisting of 124 specimens of gastric carcinoma and 16 specimens of normal gastric mucosa. The relationship between the expressions of c-Cbl, Cbl-b, and EGFR and clinicopathologic factors of gastric carcinoma were analyzed statistically.

RESULTSThe positive rates of c-Cbl, Cbl-b, and EGFR were higher in the gastric carcinoma group than in the normal group (71.0% vs. 18.0%, P<0.01; 82.3% vs. 25.0%, P<0.01; 56.5% vs. 12.5%, P<0.01, respectively). The expression of c-Cbl was positively correlated with depth of invasion (r=0.219, P=0.015), and TNM staging (r=0.266, P=0.003). The expression of Cbl-b was positively correlated with lymph node metastasis (r=0.190, P<0.034) and TNM staging (r=0.298, P<0.001). The expression of EGFR was positively correlated with depth of invasion (r=0.286, P<0.001) and TNM staging (r=0.362, P=0.000). The expression of both c-Cbl and Cbl-b was positively correlated with EGFR (r=0.241, P=0.007; r=0.183, P=0.042, respectively). Synchronous strong-positive expressions of c-Cbl, Cbl-b, and EGFR were observed in 27 specimens of gastric carcinoma, most of which were at advanced stage.

CONCLUSIONSOverexpressions of c-Cbl, Cbl-b, and EGFR are closely related to the invasion and progression of gastric carcinoma. c-Cbl and Cbl-b may serve as novel molecular markers for gastric carcinoma.

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; metabolism ; pathology ; Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; metabolism ; Disease Progression ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Staging ; Proto-Oncogene Proteins c-cbl ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; Young Adult

OBJECTIVEGastric cancer cells are insensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). To sensitize gastric cancer cells to TRAIL, we treated gastric cancer MGC803 cells with TRAIL and cisplatin.

METHODSCell proliferation was measured using MTT assay. Cell apoptosis was determined by flow cytometry. Expression of proteins was analyzed by Western blot. The distribution of lipid rafts and death receptors was analyzed by immunofluorescence microscopy. MGC803 cells were pretreated with 50 mg/L nystatin for 1 h, and followed by the treatment of cisplatin and TRAIL.

RESULTS100 µg/L TRAIL resulted in (8.51 ± 3.45)% inhibition of cell proliferation and caused (3.26 ± 0.89)% cell apoptosis in MGC803 cells. Compared with the treatment with cisplatin alone, treatment with TRAIL (100 µg/L) and cisplatin (8.49 mg/L, IC(50) dose of 24 h) led to a dramatic increase in both inhibition of cell proliferation [(52.58 ± 4.57)% vs. (76.43 ± 5.35)%, P < 0.05] and cell apoptosis [(23.10 ± 3.41)% vs. (42.56 ± 4.11)%, P < 0.05]. Moreover, cleavage of caspase-8 and caspase-3 was detected. TRAIL (100 µg/L) did not induce obvious lipid rafts aggregation and death receptor 4 (DR4) clustering, while cisplatin (8.49 mg/L) significantly promoted the localization of DR4 in aggregated lipid rafts. Pretreatment with 50 mg/L nystatin, a cholesterol-sequestering agent, triggered (3.66 ± 0.52)% cell apoptosis after 24 h. Pretreatment with nystatin for 1 h before the addition of 8.49 mg/L cisplatin for 24 h caused a decreased tendency to cell apoptosis [(25.74 ± 3.28)% vs. (22.76 ± 2.97)%]. While, pretreatment with nystatin before the addition of cisplatin and TRAIL, the proportion of apoptotic cells decreased from (43.16 ± 4.26)% to (31.52 ± 3.99)% (P < 0.05).

CONCLUSIONCisplatin enhances TRAIL-induced apoptosis in gastric cancer MGC803 cells through clustering death receptors into lipid rafts.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cisplatin ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; Membrane Microdomains ; metabolism ; Nystatin ; pharmacology ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; TNF-Related Apoptosis-Inducing Ligand ; pharmacology

Global longitudinal strain (GLS) at rest on two-dimensional speckle tracking echocardiography (2D STE) was demonstrated to help detect coronary artery disease (CAD).However,the optimal cut-off point of GLS and its diagnostic power for detecting critical CAD in non-diabetes mellitus (DM) patients are unknown.In the present study,211 patients with suspected CAD were prospectively included,with DM patients excluded.All patients underwent echocardiography and subsequently coronary angiography within 3 days.Left ventricular (LV) GLSs were quantified by 2D STE.Territorial peak systolic longitudinal strains (TLSs) were calculated based on the perfusion territories of the 3-epicardial coronary arteries in a 17-segment LV model.Critical CAD was defined as an area stenosis ≥70％ in ≥1 epicardial coronary artery (≥50％ in left main coronary artery).Totally 145 patients were diagnosed as having critical CAD by coronary angiography.Significant differences were observed in all strain parameters between patients with and without critical CAD.The area under the receiver operating charcteristic (ROC) curve (AUC) for GLS in the detection of left main (LM) or threevessel CAD was 0.875 at a cut-off value of-19.05％ with sensitivity of 78.1％ and specificity of 72.7％,which increased to 0.926 after exclusion of apical segments (cut-off value-18.66％;sensitivity 84.4％ and specificity 81.8％).The values of TLSs were significantly lower in regions supplied by stenotic arteries than in those by non-stenotic arteries.The AUC for the TLSs to identify critical stenosis of left circumflex (LCX) artery,left anterior descending (LAD) artery and right coronary artery (RCA),in order of diagnostic accuracy,was 0.818 for LCX,0.764 for LAD and 0.723 for RCA,respectively.In conclusion,in non-DM patients with suspected CAD,GLS assessed by 2D STE is an excellent predictor for LM or three-vessel CAD with high diagnostic accuracy,and a higher cut-off point than reported before should be used.Excluding apical segments in the calculation of GLS can further improve the predictive accuracy of GLS.It is unsatisfactory for TLSs to be used to identify stenotic coronary arteries.

Previous study revealed that bufalin can inhibit proliferation, and induce apoptosis in some human cancer cell lines. However, the mechanism of its anticancer effect has not been fully understood. The present study was designed to investigate the effects of bufalin-induced apoptosis on Bcl-2 and PKC in human leukemic HL-60 cells. The cell viability was determined by trypan blue dye exclusion. The apoptosis was detected by morphology, flow cytometry and DNA agarose gel electrophoresis. The expressions of Bcl-2 and PKC were analyzed by Western blot, and activity of PKC was assayed by [gamma-(32)P] isotope incorporation method. The results showed as follows: (1) proliferation of HL-60 cells was inhibited by bufalin and the IC(50) at 24, 48, 72 hours were (25.8 +/- 2.1), (8.0 +/- 1.2) and (2.3 +/- 0.3) nmol/L, respectively. (2) apoptosis of HL-60 cells was induced when the cells were treated with bufalin at concentration of 50 nmol/L for 24 hours. (3) compared with control, treatment with bufalin at concentration of 50 nmol/L for 6 - 24 hours resulted in downregulation of protein expression, decrease of phosphorylation, and cleavage of Bcl-2, simultaneously. (4) the activity of total PKC was unchanged when HL-60 cells were exposed to 1 - 100 nmol/L bufalin for 30 minutes, but PKCbetaII underwent translocation from cytosol to membrane. It is concluded that apoptosis induced by bufalin is associated with downregulation of protein expression, dephosphorylation, and cleavage of Bcl-2 in HL-60 cells.
Apoptosis ; drug effects ; Bufanolides ; pharmacology ; Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; HL-60 Cells ; Humans ; Materia Medica ; pharmacology ; Phosphorylation ; Protein Kinase C ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics

Oxaliplatin-based chemotherapy is used for treating gastric cancer. Autophagy has been extensively implicated in cancer cells; however, its function is not fully understood. Our study aimed to determine if oxaliplatin induce autophagy in gastric cancer MGC803 cells and to assess the effect of autophagy on apoptosis induced by oxaliplatin. MGC803 cells were cultured with oxaliplatin. Cell proliferation was measured using MTT assay, and apoptosis was determined by flow cytometry. Protein expression was detected by Western blot. Autophagy was observed using fluorescent microscopy. Our results showed that the rate of apoptosis was 9.73% and 16.36% when MGC803 cells were treated with 5 and 20 μg/mL oxaliplatin for 24 h, respectively. In addition, caspase activation and poly ADP-ribose polymerase (PARP) cleavage were detected. Furthermore, when MGC803 cells were treated with oxaliplatin for 24 h, an accumulation of punctate LC3 and an increase of LC3-II protein were also detected, indicating the activation of autophagy. Phosphorylation of Akt and mTOR were inhibited by oxaliplatin. Compared to oxaliplatin alone, the combination of autophagy inhibitor chlorochine and oxaliplatin significantly enhanced the inhibition of cell proliferation and the induction of cell apoptosis. In conclusion, oxaliplatin-induced protective autophagy partially prevents apoptosis in gastric cancer MGC803 cells. The combination of autophagy inhibitor and oxaliplatin may be a new therapeutic option for gastric cancer.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Autophagy ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Organoplatinum Compounds ; pharmacology ; Phosphatidylinositol 3-Kinase ; metabolism ; Poly(ADP-ribose) Polymerases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects ; Stomach Neoplasms ; metabolism ; pathology ; TOR Serine-Threonine Kinases ; metabolism

The study was aimed to explore the mechanism of SYK and CBL family of ubiquitin ligases in Bufalin-induced HL-60 cells apoptosis. Cell viability was tested by trypan blue staining and apoptosis was detected by using flow cytometry. The expressions of CBL and CBL-b and the phosphorylation of SYK were detected by using immunoprecipitation and Western blot. The results showed that Bufalin inhibited HL-60 cell proliferation in time- and dose-dependent manners. IC(50) of suppressing cell viability at 24, 48 and 72 hours were about 26.3, 7.8 and 2.0 nmol/L respectively. The high dose of bufalin already induced apoptosis of HL-60 cells at 8 hours. SYK was quickly phosphorylated, and the expressions of CBL and CBL-b were down-regulated after treatment with Bufalin. It is concluded that SYK activation and CBL protein down-regulation may be involved in Bufalin-induced HL-60 cell apoptosis.
Apoptosis ; drug effects ; Bufanolides ; pharmacology ; Cell Proliferation ; drug effects ; Down-Regulation ; Gene Expression Regulation, Leukemic ; HL-60 Cells ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Proto-Oncogene Proteins c-cbl ; metabolism ; Signal Transduction ; Syk Kinase

CD151 is a member of the tetraspanin family that is implicated as a promoter of pathological or physiological angiogenesis. C-Met is expressed on a variety of cells including vascular endothelial cells (VECs) and up-regulated during angiogenesis. In this study, we investigated whether CD151 regulated migration, proliferation, tube formation and angiogenesis of human umbilical VECs (HUVECs) with activation of C-Met. Moreover, we studied whether CD151 could affect the angiogenic molecules such as nitric oxide (NO), vascular cell adhesion molecule-1 (VCAM-1) and vascular endothelial growth factor (VEGF). The expression of CD151 was determined by Western blotting. The cell proliferation assay was performed using the cell counting kit-8 (CCK-8) method and cell migration was assessed in microchemotaxis chambers by using fetal bovine serum (FBS) as the chemotactic stimulus. The angiogenic molecules were evaluated using ELISA. The NO level was detected using NO detection kit. The potential involvement of various signaling pathways was explored using relevant antibodies. We found that proliferation, migration and tube formation of HUVECs were promoted by CD151 with activation of C-Met, FAK and CDC42, while they were suppressed with CD151 knockdown by RNAi. Similarly, the levels of NO, VCAM-1 and VEGF in HUVECs were increased by CD151, but they were inhibited with CD151 knockdown by RNAi. These data suggested that CD151 could promote migration, proliferation, tube formation and angiogenesis of HUVECs, which was possibly related to the C-Met signaling pathways.
Base Sequence ; Human Umbilical Vein Endothelial Cells ; Humans ; Neovascularization, Physiologic ; RNA, Small Interfering ; genetics ; Receptor Protein-Tyrosine Kinases ; metabolism ; Signal Transduction ; Tetraspanin 24 ; genetics ; metabolism

Background: Cervical cancer is the sixth most common cancer in Chinese women. A standard treatment modality for cervical cancer is the combination of surgery, chemotherapy, external-beam radiotherapy and intracavitary brachytherapy. The aim of this study was to retrospectively assess the long-term treatment outcomes of patients with cervical cancer who were treated with californium-252 neutron brachytherapy combined with external-beam radiotherapy plus concurrent chemotherapy.Methods: We retrospectively analyzed the medical records of 150 patients with primary stages IB-IVB cervical cancer who received neutron brachytherapy combined with external-beam radiotherapy concurrently with cisplatin chemotherapy.All patients were followed up. Using an actuarial analysis, patient outcomes and treatment-related adverse effects were evaluated and compared.Results: The median overall survival (OS) was 33.2 months. The 3-year progression-free survival rates for patients with stages Ⅰ—Ⅱ, Ⅲ, and Ⅳ diseases were 81.0% (68/84), 65.0% (39/60), and 0% (0/6), respectively; the 3-year OS rates were 90.5% (76/84), 85.0% (51/60), and 16.7% (1/6), respectively. Vaginal bleeding was controlled within the median time of 4.0 days. One month after treatment, 97.3% of patients achieved short-term local control. The local recurrence rates for patients with stages Ⅰ—Ⅱ, Ⅲ, and Ⅳ disease were 4.8% (4/84), 11.7% (7/60), and 33.3% (2/6), respectively, and the occurrence rates of distant metastasis were 16.7% (14/84), 25.0% (15/60), and 100.0% (6/6), respectively. Cancer stage,tumor size, and lymph node metastasis were identified as prognostic risk factors, but only lymph node metastasis was found to be an independent prognostic factor. The most common adverse effects during treatment were grades 1 and 2 irradiation-related proctitis and radiocystitis.Conclusion: For patients with cervical cancer, neutron brachytherapy combined with external-beam radiotherapy plus concurrent chemotherapy produces a rapid response and greatly improves local control and long-term survival rates with tolerable adverse effects.

Objective To investigate the efficacy of CD151 gene delivery in promoting blood perfusion in swines after myocardial infarction.Metheds Swines received coronary artery ligation and intramyocardial iniection with rAAV-CD151,rAAV-anti-CD151 or rAAV-GFP.Eight weeks after vector injection,Western blot,immunostaining and 13N-labeled NH3 PET were performed to detect gene expression and biological effects of various treatments.Results High level of CD151 protein expression was detected in the rAAV-CD151 group.The capillary density in the rAAV-CD151 group[(83.8±6.7)n/mm2]was significantly higher than that in the control group[(33.2±4.5)n/mm2]and rAAV-GFP group[(41.6±5.6)n/mm2](all P＜0.05);the arteriole density in the rAAV-CD151 group[(16.4±2.5)n/mm2]was also higher than that in the control group[(6.6±2.3)n/mm2]and the rAAV-GFP group[(8.4±1.6)n/mm2](all P＜0.05).However,the lowest capillary density and arteriole density were evldanced in rAAV-anti-CD151 group.Myocardial blood perfusion was significantly increased in rAAV-CD151 group and significantly reduced in rAAV-anti-CD151 group(a11 P＜0.05 vs.control).Conclusion Intramyocardial injection of rAAV-CD151 could enhance the myoeardial express of CD151 protein,increase capillary and arteriole densities and improve blood perfusion in swine with myoeardial infarction.