ß-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation.

AIM: To explore the potential of ß-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms. METHODS: SGC7901, MKN45, MKN28, N87, and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was used to determine the effects of ß-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death, respectively. A proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), was employed to screen the proteins regulated by ß-elemene pretreatment prior to ionizing radiation (IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1 (Pak1) to target Pak1 signaling. Protein levels of PAK1IP1 (p21-activated protein kinase-interacting protein 1), total Pak1 (t-Pak1), phospho-Pak1 (T423), phospho-ERK1/2 (Thr202/Tyr204), and cleaved caspase-3 (17 kDa) were assessed by western blotting. RESULTS: MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. ß-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally, ß-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45 (10.4% ± 0.9% vs 34.8% ± 2.8%, P < 0.05) and SGC7901 (11.6% ± 0.9% vs 46.7% ± 5.2%, P < 0.05) human gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Through iTRAQ analysis and western blot validation, we found that ß-elemene upregulated PAK1IP1 and downregulated phospho-Pak1 (T423) and phospho-ERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1 (T423). Pretreatment with ß-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition, IPA-3 increased radiation-induced cell death in MKN45 (13.4% ± 0.3% vs 26.6% ± 1.0%, P < 0.05) and SGC7901 (16.0% ± 0.6% vs 37.3% ± 1.7%, P < 0.05) gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation. CONCLUSION: This is the first demonstration that ß-elemene enhances radiosensitivity of gastric cancer cells, and that the mechanism involves inhibition of Pak1 signaling.

Anticancer effects of ß-elemene in gastric cancer cells and its potential underlying proteins: a proteomic study.

Gastric cancer is a common malignancy with a poor prognosis. ß-elemene is a broad-spectrum anticancer drug extracted from the traditional Chinese medicinal herb Curcuma wenyujin. In the present study, we investigated the anticancer effects of ß-elemene in gastric cancer cells and the potential proteins involved. Human SGC7901 and MKN45 gastric cancer cells were treated with different concentrations of ß-elemene. Cell viability, clonogenic survival and apoptotic cell death were assessed. ß-elemene inhibited viability and decreased clonogenic survival of gastric cancer cells in a dose-dependent manner. Apoptosis induction contributed to the anticancer effects. We then employed a proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), to detect the proteins altered by ß-elemene. In total, 147 upregulated proteins and 86 downregulated proteins were identified in response to ß-elemene treatment in SGC7901 gastric cancer cells. Among them, expression of p21-activated protein kinase­interacting protein 1 (PAK1IP1), Bcl-2-associated transcription factor 1 (BTF) and topoisomerase 2-α (TOPIIα) were validated by western blot analyses and the trends were consistent with iTRAQ results. Top pathways involved in ß-elemene treatment in SGC7901 gastric cancer cells included ribosome signaling, peroxisome proliferator-activated receptors (PPARs) signaling pathway, regulation of actin cytoskeleton, phagosome, biosynthesis and metabolism of some amino acids. Collectively, our results suggest a promising therapeutic role of ß-elemene in gastric cancer. The differentially expressed proteins provide further insight into the potential mechanisms involved in gastric cancer treatment using ß-elemene.

[Relevance between carotid plaque scores and the severity of coronary atherosclerosis].

OBJECTIVE: To explore the relevance between carotid plaque and the severity of coronary artery disease. METHODS: A total of 207 patients(149 males,58 females) undergoing coronary angiography were definitely diagnosed with coronary heart disease. They were divided into 3 groups of one-vessel disease (1VD, n = 69), two-vessel disease (2VD, n = 57) and three-or-more vessel disease (3VD, n = 81) by the number of involved vessels. Their physical findings, biochemical data and carotid ultrasonographic results were collected. And the scores of Crouse, Gensini and Leaman were calculated to compare the relevance. RESULTS: No significant differences existed among all three groups except for a higher age and the presence of plaque in 2VD and 3VD groups than 1VD group ((63 ± 11) and (60 ± 11) vs (57 ± 10)years old, 82%(n = 47) and 81%(n = 66) vs 65%(n = 45), both P < 0.05) . Crouse had a positive correlation with Gensini (r = 0.455, P < 0.01) and Leaman scores (r = 0.358, P < 0.01) . CONCLUSION: Assessment of plaque scores by carotid ultrasonography is clinically relevant for predicting the severity of coronary artery disease.

[The expression of nicotinamide phosphoribosyl transferase and vascular endothelial growth factor-A in gastric carcinoma and their clinical significance].

OBJECTIVES: To study the expression of nicotinamide phosphoribosyl transferase (Nampt) and vascular endothelial growth factor-A (VEGF-A) in gastric carcinoma and investigate their correlations to clinicopathologic features and prognostic significance. METHODS: The proteins of Nampt and VEGF-A in 68 specimens of gastric carcinoma and 59 specimens normal gastric tissue were detected by immunohistochemistry during January 2000 to December 2004, and the 68 patients were followed up. RESULTS: Nampt protein was detected in the cytoplasm of both tissues, and Nampt in gastric carcinoma (13 ± 5) were significantly higher than that in normal gastric tissue (6 ± 3) (t = 7.46, P < 0.01). The expression of Nampt was correlated to invasive depth (F = 4.693, P = 0.034), lymph node metastasis (F = 4.027, P = 0.049), clinical TNM stage (F = 9.979, P = 0.002), but not to gender, age, tumor location, tumor size, differentiation (P > 0.05). The expression of Nampt is correlated with survival of patients that underwent surgical resection for gastric cancer. The survival rate of patients in negative of Nampt was very higher than that of the positive patients, and its co-expression with VEGF-A showed a trend towards poorer survival. The positive correlation was found between the expression of Nampt and VEGF-A in gastric carcinoma (r = 0.293, P = 0.015). CONCLUSIONS: The expression of Nampt is positively correlated to that of VEGF-A in gastric carcinoma. The correlation between the expression of Nampt and VEGF-A in gastric carcinoma plays an important role cooperatively in carcinogenesis, development and metastasis of gastric carcinoma.

[Preliminary study of real-time three-dimensional dobutamine stress echocardiography for coronary artery disease assessment].

OBJECTIVE: To evaluate the efficacy and safety of real-time three-dimensional dobutamine stress echocardiography for coronary artery disease assessment. METHODS: A total of 14 patients suspected of coronary artery disease (CAD) underwent real-time three-dimensional dobutamine stress echocardiography. The initial infusion rate of dobutamine was 5 µg×kg⁻¹ ×min⁻¹, followed by 10 µg×kg⁻¹×min⁻¹ and peak infusion 20 µg×kg⁻¹×min⁻¹ in 3 min stages. At baseline state, stress stages and after the study, the real-time three-dimensional (RT3D) images were captured and assessed by wall motion score index (WMSI) and regional ejection fraction (rEF). And the parameters of these two modalities versus coronary angiography (CAG) were compared and analyzed. Adverse reactions were also observed. RESULTS: All patients completed the stress study uneventfully. As compared with CAG, these two modalities showed no significant difference (P > 0.05) and satisfactory agreement (κ values of 0.704 and 0.759 respectively). The diagnostic parameters of these modalities were: sensitivity (78% vs 89%), specificity (92% vs 88%), positive predictive value (PPV) (88% vs 84%), negative predictive value (NPV) (85% vs 91%) and overall accuracy (86% vs 88%). CONCLUSION: Real-time three-dimensional dobutamine stress echocardiography is an effective, rapid and safe technique of assessing coronary artery disease. It is worthy of wider clinical applications.

Synthesis and photonic band calculations of NCP face-centered cubic photonic crystals of TiO2 hollow spheres.

With the help of self-assembly, thermal sintering, selective etching techniques and sol-gel process, the non-close packed (ncp) face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The photonic bandgap calculations indicate that the ncp structure of TiO2 hollow spheres was easier to open the pseudogaps than close packed system at the lowest energy.