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.

OBJECTIVEA total of 27 samples belonging to 5 cultivars of Fructus Aurantii (Citrus aurantium), i. e. cv. Xiucheng, cv. Xiangcheng, cv. Lecheng, cv. Jizicheng, and cv. Youzicheng, collected at Changfu and Huanggang, Zhangshu City, Jiangxi Province, were assayed to reveal the genetic relationship among the cultivars and the accordance between morphological and molecular markers.

METHODCultivar identification was based on morphology and cultivar relationship was based on Inter-simple sequence repeats (ISSR).

RESULTTwenty out of 40 ISSR primers screened generated 392 loci across all 27 samples with 315 informative loci. The UPGMA dendrogram showed that samples within cv. Xiucheng and cv. Xiangcheng from Changfu were closely related. However, samples of cv. Lecheng, cv. Jizicheng and cv. Youzicheng from Huanggang, or cv. Xiucheng and cv. Xiangcheng from both Changfu and Huanggang did not exhibited close relationships within each cultivars.

CONCLUSIONBased on morphology the same cultivar grown in different plantations, or even within a single plantation sometimes do not show close genetic relationship, indicating diverse origin of the cultivars. Synonyms or homonyms are believed to common phenomenon in Fructus Aurantii production. To solve the problem ISSR markers can serve a kind of molecular markers which are preferable to partition genetic variations within and between cultivars and to establish genetic relationships among them.

Citrus ; anatomy & histology ; classification ; genetics ; DNA Primers ; DNA, Plant ; genetics ; Fruit ; anatomy & histology ; genetics ; Genetic Markers ; Genetic Variation ; Phylogeny ; Plants, Medicinal ; anatomy & histology ; classification ; genetics ; Repetitive Sequences, Nucleic Acid

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

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

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

OBJECTIVETo study hypertension control, follow up and the factors associated with the rate of hypertension control.

METHODSThrough a community-based study, the routine data were collected through a community hypertension managing software for one year.

RESULTSThere were 3375 hypertension patients above 60 years old recruited in the information system. In the baseline, the rate of blood pressure control was 63.5%, and arranging intervals up to 6 months was 66.9%. Hypertension control rate for the baseline, the third month and the sixth month was 61.8%, 62.4% and 61.6%, respectively (chi2 = 0.16, P = 0.69). Among hypertensives whose blood pressure was stabilized in baseline, hypertension control rates for the third month and the sixth month was 72.9.8% and 72.1%, respectively (chi2 = 0.26, P = 0.61). Blood pressure stabilized over 6 months in comparing with others, and the proportion for regular taking medication was 96.2% and 97.7% (chi2 = 3.58, P = 0.06). The proportion for physical activity, less salt intake, weight control was significantly higher in the patients whose blood pressure control well over 6 month.

CONCLUSIONRate of blood pressure control among elderly patient with hypertension who frequently consults the doctor in the community is high. Ineffectiveness in systolic and diabetes control is the important factor, which decreases the rate of blood pressure. Physical activity, less salt intake, and weight control are of help to hypertension control. For those, the blood pressure are stabilized, a follow up with 3 to 6 months interval is appropriate.

Aged ; Antihypertensive Agents ; therapeutic use ; Blood Pressure ; Female ; Follow-Up Studies ; Humans ; Hypertension ; drug therapy ; physiopathology ; Male

BACKGROUNDAtrial fibrillation (AF) is the most frequent tachyarrhythmia in patients with a permanent pacemaker. Angiotensin II receptor antagonists have a protective effect against the occurrence of AF in patients with heart diseases. This study aimed to assess the effectiveness of olmesartan in the prevention of new-onset AF and AF burden in atrioventricular block (AVB) patients with dual-chamber (DDD) pacemaker implantation.

METHODSThis was a single-center, prospective, randomized, single-blind, controlled clinical study. A total of 116 AVB patients, who received DDD pacemakers implantation with the percentage of ventricular pacing (VP%) ≥40% from April 22, 2011 to December 24, 2012, were prospectively randomized to olmesartan group (20 mg per day; n = 57) or control group (n = 59). Patients were followed up using pacemaker programming, 12-lead electrocardiography in the intrinsic sinus rhythm, laboratory examinations, and transthoracic echocardiography at 24 months. Atrial high rate events (AHREs) were defined as 180 beats/min over a minimum of 5 min. AF burden was calculated by the number of hours with AHREs divided by the number of measurement hours.

RESULTSTen (17.5%) patients in the olmesartan group and 24 patients (40.7%) in the control group occurred new-onset AF, and the difference between two groups was statistically significant (P = 0.04). AF burden was lower in olmesartan group than that in control group (8.02 ± 3.10% vs. 13.66 ± 6.14%, P = 0.04). There were no significant differences in mean days to the first occurrence of AHREs and mean cumulative numbers of AHREs between two groups (P = 0.89 and P = 0.42, respectively). Moreover, olmesartan group had smaller values of maximal P-wave durations and P-wave dispersion (PD) after 24 months follow-up compared with the control group (109.5 ± 7.4 ms vs. 113.4 ± 7.1 ms, P = 0.00; and 40.6 ± 4.5 ms vs. 43.3 ± 4.4 ms, P = 0.02, respectively). Left ventricular end-diastolic diameter and left ventricular ejection fraction were not significantly different between two groups (both P > 0.05).

CONCLUSIONThis study suggested that 24-month of olmesartan therapy could reduce new-onset AF and AF burden in patients with DDD pacemakers.

CLINICAL TRIAL REGISTRATIONChiCTR-TRC-12004443; http://www.chictrdb.org.

Aged ; Angiotensin Receptor Antagonists ; therapeutic use ; Atrial Fibrillation ; drug therapy ; Atrioventricular Block ; drug therapy ; Female ; Humans ; Imidazoles ; therapeutic use ; Male ; Middle Aged ; Single-Blind Method ; Tetrazoles ; therapeutic use

OBJECTIVE: To explore the mechanisms underlying the proliferative inhibition of Chinese herbal medicine Kang-Ai injection (KAI) in gastric cancer cells. METHODS: Gastric cancer cell lines MGC803 and BGC823 were treated by 0, 0.3%, 1%, 3% and 10% KAI for 24, 48 and 72 h, respectively. The cell proliferation was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The apoptosis and cell cycle were evaluated by flow cytometry. Interleukin (IL)-6 mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA), respectively. The protein expression levels of cyclin A, cyclin E, cyclin B1, cyclin D1, p21, retinoblastoma (RB), protein kinase B (AKT), extracellular regulated protein kinases (ERK), signal transducer and activator of transcription (STAT) 1 and STAT3 were detected by Western blot. RESULTS: KAI inhibited the proliferation of MGC803 and BGC823 gastric cancer cells in dose- and time-dependent manner. After treated with KAI for 48 h, the proportion of G1 phase was increased, expression level of cyclin D1 and phosphorylation-RB were down-regulated, whereas the expression of p21 was up-regulated (all P<0.01). Furthermore, 48-h treatment with KAI decreased the phosphorylation level of STAT3, inhibited the mRNA and protein expressions of IL-6 (all P<0.01). IL-6 at dose of 10 ng/mL significantly attenuated the proliferative effect of both 3% and 10% KAI, and recovered KAI-inhibited STAT3 phosphorylation and cyclin D1 expression level (all P<0.01). CONCLUSION KAI exerted an anti-proliferative function by inhibiting IL-6/STAT3 signaling pathway followed by the induction of G₁ phase arrest in gastric cancer cells.
Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1/pharmacology* ; Humans ; Interleukin-6/metabolism* ; RNA, Messenger/metabolism* ; STAT3 Transcription Factor/metabolism* ; Stomach Neoplasms/genetics*