Atezolizumab Monotherapy or Plus Chemotherapy in First-Line Treatment for Advanced Non-Small Cell Lung Cancer Patients: A Meta-Analysis

Background

Atezolizumab plus chemotherapy has been recommended as a first-line treatment option for patients with advanced non-small cell lung carcinoma (NSCLC) irrespective of programmed cell death-ligand 1 (PD-L1) expression. Currently, little is known about the efficacy and treatment-related adverse effects (TRAEs) of subtracting chemotherapy from the combination for patients with high PD-L1 expression. Thus, we performed an indirect comparison between atezolizumab plus chemotherapy and atezolizumab alone.

Methods

A total of five eligible randomized controlled trials (RCTs) were identified from PubMed, EMBASE, and Cochrane Central controlled trial registries, using keywords including atezolizumab, PD-1, PD-L1, NSCLC, and RCT. The clinical outcomes of objective response rate (ORR), progression-free survival (PFS), OS, and TRAEs were extracted and evaluated. Using indirect analysis, the efficacy and TRAEs were compared between arm A (atezolizumab plus chemotherapy) and arm C (atezolizumab), linked by arm B (chemotherapy).

Results

Direct comparison revealed that both atezolizumab plus chemotherapy (HR 0.65, P = 0.003) and atezolizumab alone (HR 0.59, P = 0.010) significantly improved OS compared with chemotherapy. More importantly, the indirect comparison showed that atezolizumab plus chemotherapy was not superior to atezolizumab regarding OS (RR 1.10, P =0.695) and ORR (RR 1.11, P = 0.645). However, patients who received atezolizumab combined with chemotherapy experienced more ≥ grade 3 TRAEs (RR 4.23, P<0.001) and TRAEs leading to drug discontinuation (RR 3.60, P<0.001) than those treated with atezolizumab monotherapy.

Conclusions

Atezolizumab monotherapy might be a better treatment option for patients with advanced NSCLC and high PD-L1 expression than atezolizumab plus chemotherapy.

[Prognostic factor analysis of patients with unresectablelung squamous cell carcinoma]

Objective: To investigate the prognostic factors associated with unresectable (stage Ⅲa-Ⅳ, according to the 7th edition of the AJCC cancer staging manual) lung squamous cell carcinoma. Methods: We retrospectively analyzed 350 patients with inoperable locally advanced, recurrent or metastatic lung squamous cell carcinoma who were admitted to the First Affiliated Hospital of Chinese Medical University from January 2005 to June 2018. The clinical pathological data, treatment and survival follow-up information of the patients were collected. Kaplan-Meier survival was used to compare the overall survival rate of different risk groups. Univariate analysis and multivariate Cox regression analysis were used to determine the independent prognostic factors. Results: A total of 350 patients were enrolled. The median overall survival (OS) of these patients was 16.7 months. Univariate analysis showed the stage, Eastern Cooperative Oncology Group(ECOG), first-line chemotherapy evaluation (RECIST version 1.1), radiation therapy, number of systemic chemotherapy lines, carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), C reactive protein (CRP), lactate dehydrogenase (LDH), whether liver, brain, boneor metastasis were associated with the OS of patients with advanced lung squamous cell carcinoma (all P<0.05). Multivariate analysis showed that ECOG score (HR=1.855, 95% CI: 1.063-3.239, P=0.030), whether underwent lung resection (HR=0.476, 95%CI: 0.302-0.751, P=0.001), first-line chemotherapy evaluation [stable disease (SD): HR=0.293, 95%CI: 0.159-0.540, P<0.001; complete response (CR)+ partial response (PR): HR=0.223, 95%CI: 0.120-0.413, P<0.001], CRP (HR=1.715, 95% CI: 1.080-2.723, P=0.042), LDH (HR=1.116, 95%CI: 0.780-1.596, P=0.002) and CEA (HR=1.855, 95%CI: 1.361-2.528, P<0.001) before chemotherapy, liver metastasis (HR=2.453, 95%CI: 1.461-4.120, P=0.001) are independent prognostic factors for patients with unresectable lung squamous cell carcinoma. Conclusion: The ECOG score, surgical treatment history, first-line chemotherapy, LDH, CEA and CRP before chemotherapy, liver metastasis are independent prognostic factors for patients with advanced lung squamous cell carcinoma.

FEN1 is a prognostic biomarker for ER+ breast cancer and associated with tamoxifen resistance through the ERα/cyclin D1/Rb axis

Background

Tamoxifen is an important choice in endocrine therapy for patients with oestrogen receptor-positive (ER+) breast cancer, and disease progression-associated resistance to tamoxifen therapy is still challenging. Flap endonuclease-1 (FEN1) is used as a prognostic biomarker and is considered to participate in proliferation, migration, and drug resistance in multiple cancers, especially breast cancer, but the prognostic function of FEN1 in ER+ breast cancer, and whether FEN1 is related to tamoxifen resistance or not, remain to be explored.

Methods

On-line database Kaplan-Meier (KM) plotter, GEO datasets, and immunohistochemistry were used to analyse the prognostic value of FEN1 in ER+ breast cancer from mRNA and protein levels. Cell viability assay and colony formation assays showed the response of tamoxifen in MCF-7 and T47D cells. Microarray data with FEN1 siRNA versus control group in MCF-7 cells were analysed by Gene Set Enrichment Analysis (GSEA). The protein levels downstream of FEN1 were detected by western blot assay.

Results

ER+ breast cancer patients who received tamoxifen for adjuvant endocrine therapy with poor prognosis showed a high expression of FEN1. MCF-7 and T47D appeared resistant to tamoxifen after FEN1 over-expression and increased sensitivity to tamoxifen after FEN1 knockdown. Importantly, FEN1 over-expression could activate tamoxifen resistance through the ERα/cyclin D1/Rb axis.

Conclusions

As a biomarker of tamoxifen effectiveness, FEN1 participates in tamoxifen resistance through ERα/cyclin D1/Rb axis. In the future, reversing tamoxifen resistance by knocking-down FEN1 or by way of action as a small molecular inhibitor of FEN1 warrants further investigation.

Biological and clinical significance of flap endonuclease‑1 in triple‑negative breast cancer: Support of metastasis and a poor prognosis

Flap endonuclease‑1 (FEN1), a structure‑specific nuclease participating in DNA replication and repair processes, has been confirmed to promote the proliferation and drug resistance of tumor cells. However, the biological functions of FEN1 in cancer cell migration and invasion have not been defined. In the present study, using online database analysis and immunohistochemistry of the specimens, it was found that FEN1 expression was associated with a highly invasive triple‑negative breast cancer (TNBC) subtype in both breast cancer samples from the Oncomine database and from patients recruited into the study. Furthermore, FEN1 was an important biomarker of lymph node metastasis and poor prognosis in patients with TNBC. FEN1 promoted migration of TNBC cell lines and FEN1 knockdown reduced the number of spontaneous lung metastasis in vivo. Ingenuity Pathway Analysis of FEN1‑related transcripts in 198 patients with TNBC demonstrated that the polo‑like kinase family may be the downstream target of FEN1. PLK4 was further identified as a critical target of FEN1 mediating TNBC cell migration, by regulating actin cytoskeleton rearrangement. The results of the present study validate FEN1 as a therapeutic target in patients with TNBC and revealed a new role for FEN1 in regulating TNBC invasion and metastasis.

FKBP10 Acts as a New Biomarker for Prognosis and Lymph Node Metastasis of Gastric Cancer by Bioinformatics Analysis and in Vitro Experiments

Purpose

To explore the role of FKBP prolyl isomerase 10 (FKBP10) protein in the progression of gastric cancer.

Methods

Four independent gastric cancer databases (GSE27342, GSE29272, GSE54129 and TCGA-STAD) were used to identify differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was used to identify the abnormally active pathways in patients with gastric cancer. Univariate Cox regression analysis was used to identify genes with stable prognostic value in gastric cancer patients based on three independent gastric cancer databases (GSE15459, GSE62254, TCGA-STAD). Gene set enrichment analysis (GSEA) was used to explore the possible pathways related to FKBP10. The reverse transcription-polymerase chain reaction (RT-PCR) was employed to determine the expression of FKBP10 mRNA in the HGC-27 and MKN-7 cell lines. Adhesion assay was used to detect changes in cell adhesion ability. FKBP10, ITGA1, ITGA2, ITGA5, ITGAV, ITGA6, P-AKT₄₇₃, P-AKT₃₀₈, AKT, and β-actin were evaluated by Western blot (WB).

Results

We first performed differential expression genes (DEGs) screening of four independent GC databases (GSE27342, GSE29272, GSE54129 and TCGA-STAD). Eighty-nine genes showed consistent up-regulation in GC, the results of pathway analysis showed that they were related to “Focal adhesion”. The prognostic value of these 89 genes was tested in three independent GC databases GSE15459, GSE62254 and TCGA-STAD cohort. Finally, 12 genes, in which the expression of FKBP10 was prominently increased in patients with lymph node metastasis (LNM), showed stable prognostic value. The following gene set enrichment analysis (GSEA) also showed that FKBP10 is mainly involved in cell adhesion process, while adhesion experiments confirmed that cell adhesion was down-regulated after silencing FKBP10 in GC cells, and adhesion-related molecules integrin αV and α6 were down-regulated.

Conclusion

FKBP10 may be used as a marker for lymph node metastasis of GC and could be used as a potential target for future treatment of GC.

Integrated bioinformatics analysis for the identification of potential key genes affecting the pathogenesis of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (CCRCC) is a typical type of RCC with the worst prognosis among the common epithelial neoplasms of the kidney. However, its molecular pathogenesis remains unknown. Therefore, the aim of the present study was to screen for effective and potential pathogenic biomarkers of CCRCC. The gene expression profile of the GSE16441, GSE36895, GSE40435, GSE46699, GSE66270 and GSE71963 datasets were downloaded from the Gene Expression Omnibus database. First, the limma package in R language was used to identify differentially expressed genes (DEGs) in each dataset. The robust and strong DEGs were explored using the robust rank aggregation method. A total of 980 markedly robust DEGs were identified (429 upregulated and 551 downregulated). According to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, these DEGs exhibited an obvious enrichment in various cancer-related biological pathways and functions. The Search Tool for the Retrieval of Interacting Genes/Proteins database was used for the construction of a protein-protein interaction (PPI) network, the Cytoscape MCODE plug-in for module analysis and the cytoHubba plug-in to identify hub genes from the aforementioned DEGs. A total of four key modules were identified in the PPI network. A total of six hub genes, including C-X-C motif chemokine ligand 12, bradykinin receptor B2, adenylate cyclase 7, calcium sensing receptor (CASR), kininogen 1 and lysophosphatidic acid receptor 5, were identified. The DEG results of the hub genes were verified using The Cancer Genome Atlas database, and CASR was found to be significantly associated with the prognosis of patients with CCRCC. In conclusion, the present study provided new insight and potential biomarkers for the diagnosis and prognosis of CCRCC.

Effects of Apatinib on the Pharmacokinetics of Nifedipine and Warfarin in Patients with Advanced Solid Tumors

Background and Purpose

Apatinib is a small-molecule tyrosine kinase inhibitor for the treatment of recurrent or progressive advanced-stage gastric adenocarcinoma or gastroesophageal junction cancer. The in vitro inhibition studies suggested that apatinib exerted potent inhibition on CYP3A4 and CYP2C9. To evaluate the potential of apatinib as a perpetrator in CYP450-based drug–drug interactions in vivo, nifedipine and warfarin were, respectively, selected in the present study as the probe substrates of CYP3A4 and CYP2C9 for clinical drug–drug interaction studies. Since hypertension and thrombus are common adverse effects of vascular targeting anticancer agents, nifedipine and warfarin are usually coadministered with apatinib in clinical practice.

Methods

A single-center, open-label, single-arm, and self-controlled trial was conducted in patients with advanced solid tumors. The patients received a single dose of 30 mg nifedipine on Day 1/14 and a single dose of 3 mg warfarin on Day 3/16. On Day 9–21, the subjects received a daily dose of 750 mg apatinib, respectively. The pharmacokinetics of nifedipine and warfarin in the absence or presence of apatinib was, respectively, investigated.

Results

Compared with the single oral administration, coadministration with apatinib contributed to the significant increases of AUC_0–48h and C_max of nifedipine by 83% (90% confidence interval [CI] 1.46–2.31) and 64% (90% CI 1.34–2.01), respectively. Similarly, coadministration with apatinib contributed to the significant increases of AUC_0-t and C_max of S-warfarin by 92% (90% CI 1.68–2.18) and 24% (90% CI 1.10–1.39), respectively.

Conclusion

Concomitant apatinib administration resulted in significant increases in systemic exposure to nifedipine and S-warfarin. Owing to the risk of pharmacokinetic drug–drug interactions based on CYP3A4/CYP2C9 inhibition by apatinib, caution is advised in the concurrent use of apatinib with either CYP2C9 or CYP3A4 substrates.

Inhibition of FEN1 Increases Arsenic Trioxide-Induced ROS Accumulation and Cell Death: Novel Therapeutic Potential for Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer, which is very difficult to treat and commonly develops resistance to chemotherapy. The following study investigated whether the inhibition of Flap Endonuclease 1 (FEN1) expression, the key enzyme in the base excision repair (BER) pathway, could improve the anti-tumor effect of arsenic trioxide (ATO), which is a reactive oxygen species (ROS) inducer. Our data showed that ATO could increase the expression of FEN1, and the knockdown of FEN1 could significantly enhance the sensitivity of TNBC cells to ATO both in vitro and in vivo. Further mechanism studies revealed that silencing FEN1 in combination with low doses of ATO might increase intracellular ROS and reduce glutathione (GSH) levels, by reducing the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2); elevating ROS leaded to apoptosis and p38 and JNK pathway activating. In conclusion, our study suggested the combination of FEN1 knockdown and ATO could induce TNBC cell death by promoting ROS production. FEN1 knockdown can effectively decrease the application concentrations of ATO, thus providing a possibility for the treatment of TNBC with ATO.

DNMT3a promotes proliferation by activating the STAT3 signaling pathway and depressing apoptosis in pancreatic cancer

Background

Although aberrant DNA methyltransferase 3a (DNMT3a) expression is important to the tumorigenesis of pancreatic ductal adenocarcinoma (PDAC), the role of DNMT3a in PDAC prognosis is not clarified yet due to the limited studies and lacking of underlying molecular mechanism.

Methods

The expression of DNMT3a was examined by immunohistochemistry in PDAC tissues. Gene expression profiles assays were conducted to explore the impact of DNMT3a on biological processes and signal pathways. Cell cycle and apoptosis were measured by flow cytometry. Western blotting and real-time qPCR assays were used to explore the impact of DNMT3a on expression of protein and mRNA related to cell cycle, STAT3 signaling pathway and apoptosis.

Results

DNMT3a was overexpressed and closely associated with poor outcomes of PDAC. DNMT3a knockdown restrained PDAC cell proliferation, induced cell cycle arrest and promoted apoptosis in vitro. Affymetrix GeneChip Human Transcriptome Array identified that the cell cycle-related process was most significantly associated with DNMT3a. DNMT3a knockdown induced G1-S phase transition arrest by decreasing the expression of cyclin D1, which was mediated by the reduction of IL8 and the subsequent inactivation of STAT3 signaling pathway. Furthermore, exogenous apoptosis was also promoted after DNMT3a knockdown, probably via up-regulation of DNA transcription and expression in CASP8.

Conclusion

These findings indicate that DNMT3a plays an important role in PDAC progression. DNMT3a may serve as a prognostic biomarker and a therapeutic strategy candidate in PDAC.

DYNC1I1 Promotes the Proliferation and Migration of Gastric Cancer by Up-Regulating IL-6 Expression

Gastric cancer is one of the top five malignant tumors worldwide. At present, the molecular mechanisms of gastric cancer progression are still not completely clear. Cytoplasmic dynein regulates intracellular transport and mitotic spindle localization, and its abnormal function is crucial for tumorigenesis, promotes tumor cell cycle progression, and tumor migration. DYNC1I1 is an important binding subunit of cytoplasmic dynein. However, studies on DYNC1I1 in tumors are currently limited. In the current study, we found that high DYNC1I1 expression in gastric cancer is associated with poor prognosis and is an independent prognostic factor. DYNC1I1 promoted the proliferation and migration of gastric cancer cells both in vitro and in vivo. DYNC1I1 also upregulated IL-6 expression by increasing NF-κB nuclear translocation. Collectively, these data revealed an important role for the DYNC1I1-driven IL-6/STAT pathway in gastric cancer proliferation and migration, suggesting that DYNC1I1 may be a potential therapeutic target for gastric cancer.

Genomewide identification of a novel six-LncRNA signature to improve prognosis prediction in resectable hepatocellular carcinoma

The current prognostic long noncoding RNA (lncRNA) signatures for hepatocellular carcinoma (HCC) are still controversial and need to be optimized by systematic bioinformatics analyses with suitable methods and appropriate patients. Therefore, we performed the study to establish a credible lncRNA signature for HCC outcome prediction and explore the related mechanisms. Based on the lncRNA profile and the clinical data of carefully selected HCC patients (n = 164) in TCGA, six of 12727 lncRNAs, MIR22HG, CTC‐297N7.9, CTD‐2139B15.2, RP11‐589N15.2, RP11‐343N15.5, and RP11‐479G22.8 were identified as the independent predictors of patients’ overall survival in HCC by sequential univariate Cox and 1000 times Cox LASSO regression with 10‐fold CV, and multivariate Cox analysis with 1000 times bootstrapping. In the Kaplan‐Meier analysis with patients trichotomized by the six‐lncRNA signature, high‐risk patients showed significantly shorter survival than mid‐ and low‐risk patients (log‐rank test P < 0.0001). According to the ROCs, the six‐lncRNA signature showed superior predictive capacity than the two existing four‐lncRNA combinations and the traditional prognostic clinicopathological parameter TNM stage. Furthermore, low MIR22HG and CTC‐297N7.9, but high CTD‐2139B15.2, RP11‐589N15.2, RP11‐343N15.5, and RP11‐479G22.8, were, respectively, demonstrated to be related with the malignant phenotypes of HCC. Functionally, the six lncRNAs were disclosed to involve in the regulation of multiple cell cycle and stress response‐related pathways via mediating transcription regulation and chromatin modification. In conclusion, our study identified a novel six‐lncRNA signature for resectable HCC prognosis prediction and indicated the underlying mechanisms of HCC progression and the potential functions of the six lncRNAs awaiting further elucidation.

Distinction Between Variability-Based Modulation and Mean-Based Activation Revealed by BOLD-fMRI and Eyes-Open/Eyes-Closed Contrast

Recent BOLD-fMRI studies have revealed spatial distinction between variability- and mean-based between-condition differences, suggesting that BOLD variability could offer complementary and even orthogonal views of brain function with traditional activation. However, these findings were mainly observed in block-designed fMRI studies. As block design may not be appreciate for characterizing the low-frequency dynamics of BOLD signal, the evidences suggesting the distinction between BOLD variability and mean are less convincing. Based on the high reproducibility of signal variability modulation between continuous eyes-open (EO) and eyes-closed (EC) states, here we employed EO/EC paradigm and BOLD-fMRI to compare variability- and mean-based EO/EC differences while the subjects were in light. The comparisons were made both on block-designed and continuous EO/EC data. Our results demonstrated that the spatial patterns of variability- and mean-based EO/EC differences were largely distinct with each other, both for block-designed and continuous data. For continuous data, increases of BOLD variability were found in secondary visual cortex and decreases were mainly in primary auditory cortex, primary sensorimotor cortex and medial nuclei of thalamus, whereas no significant mean-based differences were observed. For the block-designed data, the pattern of increased variability resembled that of continuous data and the negative regions were restricted to medial thalamus and a few clusters in auditory and sensorimotor networks, whereas activation regions were mainly located in primary visual cortex and lateral nuclei of thalamus. Furthermore, with the expanding window analyses we found variability results of continuous data exhibited a rather slower dynamical process than typically considered for task activation, suggesting block design is less optimal than continuous design in characterizing BOLD variability. In sum, we provided more solid evidences that variability-based modulation could represent orthogonal views of brain function with traditional mean-based activation.

Single nucleotide polymorphisms of casitas B-lineage lymphoma proto-oncogene-b predict outcomes of patients with advanced non-small cell lung cancer after first-line platinum based doublet chemotherapy

Background

Casitas B-lineage lymphoma proto-oncogene-b (CBLB) influences the threshold of T cell activation and controlling peripheral T cell tolerance. In the present study, we hypothesize that potentially functional single nucleotide polymorphisms (SNPs) in CBLB are associated with clinical outcomes in patients advanced non-small cell lung cancer (NSCLC) treated with the first-line chemotherapy.

Methods

We genotyped three SNPs (rs2305035, rs3772534 and rs9657904) at CBLB in 116 advanced NSCLC patients with progression free survival (PFS) data and 133 advanced NSCLC patients with overall survival (OS) data, and we assessed their associations, 95% confidence interval (CI), with clinical outcomes by using Cox proportional hazards regression analyses. In silico functional analysis was also performed for the SNPs under investigation.

Results

We found that associations between the three SNPs and PFS/OS were not significant in the overall NSCLC patients. The rs2305035 AA genotype was associated with a worse PFS in female patients and those of non-smokers or light smokers (95% CI, 1.14-11.81, P=0.030; 95% CI, 1.42-10.24, P=0.008; and 95% CI, 1.39-9.93, P=0.009; respectively), compared with the GG+AA genotypes. We also found that the rs9657904 CC genotype was significantly associated with a worse OS than TT + TC genotypes in male advanced NSCLC patients. Further in silico functional analysis revealed that the rs965704 T allele was significantly associated with lower mRNA expression levels of the CBLB gene.

Conclusions

Our findings identified two CBLB SNPs (rs2305035 and rs9657904) that were significantly associated with PFS and OS in several subgroups of Chinese advanced NSCLC patients after the first-line chemotherapy.

SPARC expression in gastric cancer predicts poor prognosis: Results from a clinical cohort, pooled analysis and GSEA assay

Background

The prognostic role of Secreted Protein Acidic and Rich in Cysteine (SPARC) in gastric cancer (GC) remains controversial. We investigated the clinical significance, the survival relevance, and potential function of SPARC in GC with resected samples, online gene set GSE62254, and cell line SGC7901.

Results

High immunostaining of SPARC significantly correlated with tumor differentiation (P = 0.004), and independently predicted shorter overall survival (OS) (HR = 1.446, P = 0.022), based on the current IHC evaluation. The accuracy of the results was further validated with 1000 times bootstrapping and the time-dependent receiver-operating characteristics (ROC) curves. The meta-analysis (pooled HR = 1.60, 95% CI: 1.01−2.53) confirmed SPARC as the predictor for reduced OS in GC. Moreover, the association between enhanced SPARC expression and Adriamycin (Adr) sensitivity was revealed by GSEA, and then confirmed by comparative cellular experiments, such as the protein level analysis of SGC7901and SGC7901/Adr cell line.

Materials and Methods

Immunohistochemistry (IHC) method was used to detect SPARC expression in 137 GC cases. Meta-analysis was performed based on 5 studies published in English on PubMed up to March 2016. GSEA was performed using online data set GSE62254 and GC-related functional gene sets derived from molecular signatures database (MSigDB). Western Blot was carried out to compare protein-level differences between gastric carcinoma SGC7901 cell line and Adr resistant SGC7901/Adr cell line. MTT assay was done to confirm the induction of SPARC on Adr sensitivity

Conclusions

Increased SPARC expression in GC led to a worse clinical outcome of patients and might induce Adr sensitivity of GC cells.

FEN1 knockdown improves trastuzumab sensitivity in human epidermal growth factor 2-positive breast cancer cells

Trastuzumab has been widely applied as a treatment for human epidermal growth factor 2 (HER2)-overexpressing breast cancer. However, the therapeutic efficacy of trastuzumab is limited. Flap endonuclease 1 (FEN1) is a multifunctional endonuclease that has a crucial role in DNA recombination and repair. Inhibition of FEN1 is associated with the reversal of anticancer drug resistance. However, it is unclear whether FEN1 is involved in trastuzumab resistance. In the present study, it was demonstrated that trastuzumab increases the expression of FEN1, and FEN1 knockdown significantly enhanced the sensitivity of BT474 cells to trastuzumab (P<0.05). It was also revealed that trastuzumab induced HER receptor activation, increased binding with FEN1 and estrogen receptor α (ERα), and upregulated ERα-target gene transcription (P<0.05). Upon silencing of FEN1 expression with siRNA, activation of HER receptor and FEN1 binding to ERα were decreased, and trastuzumab-induced ERα target gene upregulation was partially ameliorated (P<0.05). These results suggest that FEN1 may mediate trastuzumab resistance via inducing HER receptor activation and enhancing ERα-target gene transcription. The findings of the present study indicate a novel role of FEN1 in trastuzumab resistance, suggesting that targeting FEN1 may enhance the efficiency of trastuzumab as a treatment for HER2-positive breast cancer.

Exploring Northwest China's agricultural water-saving strategy: analysis of water use efficiency based on an SE-DEA model conducted in Xi'an, Shaanxi Province

Worldwide, water scarcity threatens delivery of water to urban centers. Increasing water use efficiency (WUE) is often recommended to reduce water demand, especially in water-scarce areas. In this paper, agricultural water use efficiency (AWUE) is examined using the super-efficient data envelopment analysis (DEA) approach in Xi'an in Northwest China at a temporal and spatial level. The grey systems analysis technique was then adopted to identify the factors that influenced the efficiency differentials under the shortage of water resources. From the perspective of temporal scales, the AWUE increased year by year during 2004-2012, and the highest (2.05) was obtained in 2009. Additionally, the AWUE was the best in the urban area at the spatial scale. Moreover, the key influencing factors of the AWUE are the financial situations and agricultural water-saving technology. Finally, we identified several knowledge gaps and proposed water-saving strategies for increasing AWUE and reducing its water demand by: (1) improving irrigation practices (timing and amounts) based on compatible water-saving techniques; (2) maximizing regional WUE by managing water resources and allocation at regional scales as well as enhancing coordination among Chinese water governance institutes.

Clinical outcome of medium-sized hepatocellular carcinoma treated with microwave ablation

AIM: To evaluate the outcomes of patients with medium-sized hepatocellular carcinoma (HCC) who underwent percutaneous microwave ablation (MWA).

METHODS: We retrospectively reviewed all patients with a single medium-sized HCC who underwent percutaneous MWA from January 2010 to January 2013. Technical success, technical effectiveness and complications were subsequently observed. Survival curves were constructed using the Kaplan-Meier method. The Cox proportional hazards model was fitted to each variable. The relative prognostic significance of the variables for predicting overall survival rate, recurrence-free survival rate and local tumor recurrence(s) was assessed using univariate analysis. All variables with a P value < 0.20 were subjected to multivariate analysis.

RESULTS: The study included 182 patients (mean age, 58 years; age range: 22-86 years) with a single HCC (mean size, 3.72 ± 0.54 cm; range: 3.02-5.00 cm). The estimated technical effectiveness rate was 93% in 182 patients. The major complication rate was 2.7% (5/182), including liver abscess in 4 cases, and abdominal bleeding at the puncture site in 1 case. Thirty-day mortality rate was 0.5% (1/182). One patient died due to liver abscess-related septicemia. Cumulative recurrence-free survival and overall survival (OS) rates were 51%, 36%, 27% and 89%, 74%, 60% at 1, 2, and 3 years, respectively. Age (P = 0.017) and tumor diameter (P = 0.029) were independent factors associated with local tumor recurrence. None of the factors had a statistically significant impact on recurrence-free survival. Serum albumin level (P = 0.009) and new lesion(s) (P = 0.029) were independently associated with OS.

CONCLUSION: Percutaneous MWA is a relatively safe and effective treatment for patients with medium-sized HCC.

Prognostic role of the let-7 family in various carcinomas: A meta-analysis update

PURPOSE

The role of let-7 family members in cancer prognosis has been the subject of increasing interest; however, the correlation between let-7 expression and cancer prognosis remains unknown. The goal of this study was to investigate the prognostic role of let-7 expression by performing a meta-analysis update of 31 studies.

METHODS

All relevant studies were searched on PubMed and Web of Science. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated, and subgroup analysis was performed for overall survival (OS) and disease-free survival (DFS) to evaluate the relationship between high let-7 expression and cancer prognosis. Heterogeneity and publication bias were also investigated.

RESULTS

We discovered that high let-7 expression can predict a better OS (pooled HR=0.69, 95% CI 0.60-0.80, transformed from lnHR and its 95% CI) and DFS (pooled HR=0.72, 95% CI 0.54-0.96, transformed from lnHR and its 95% CI) in various carcinomas, especially in digestive cancer. Subgroup analysis showed that high let-7 expression was significantly associated with a better DFS in Asians (pooled HR=0.50, 95% CI 0.39-0.64, transformed from lnHR and its 95% CI).

CONCLUSIONS

This meta-analysis showed that high let-7 expression is a prognostic factor for better OS and DFS in cancer patients, with particularly better DFS among the Asian populations. These results suggest that clinicians should treat patients with low let-7 expression more carefully. Future studies in large-scale populations among different ethnicities and regions are needed to definitively determine if let-7 expression can be used as a predicative biomarker for clinical assessment.

Serum calcium level used as a prognostic predictor in patients with resectable pancreatic ductal adenocarcinoma

BACKGROUND AND OBJECTIVE

There is a relative scarcity of reports to evaluate the associations between serum calcium level and the prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to determine whether serum calcium level is a significant predictor for survival in PDAC patients.

METHODS

This is a retrospective cohort study. The clinicopathological characteristics, preoperative serum calcium levels and the survival data of 114 patients who underwent surgery for PDAC between January 1, 2009 and January 31, 2012 were collected. The associations between serum calcium level and overall survival were evaluated using the multivariate Cox proportional hazards model.

RESULTS

The median age of the patients was 60 years, and 64 (56.1%) of them were male. Eighty-one cases (71.1%) were dead at the last follow up. Forty-four patients (38.6%) died within the first year after surgery. The receiver operating characteristics (ROC) curve indicated a significant result for serum calcium level in predicting one-year death after surgery [area under the curve (AUC), 0.629; 95% CI 0.527-0.730, P=0.021]. In multivariate analysis, higher serum calcium levels [hazard ratio (HR), 1.922; P=0.036], diabetes (HR, 1.820; P=0.017), histologically poorly-differentiated tumor (HR, 3.342; P=0.001) and vessel invasion (HR, 1.729; P=0.023) were independent predictors of poor prognosis. Similarly, the albumin-adjusted albumin level was also an independent prognostic factor.

CONCLUSIONS

The higher serum calcium level is associated with poor prognosis in patients with resectable PDAC and the level of serum calcium can predict death within one year after surgery.

Correlation between PARP-1 Val762Ala polymorphism and the risk of lung cancer in a Chinese population

The aim of this study was to investigate the relationship of the PARP-1 Val762Ala (rs1136410 T>C) polymorphism and the risk of lung cancer. A population-based case-control study of 373 lung cancer patients and 360 healthy control subjects (individually matched on age and gender) in a Chinese population was conducted. Genomic DNA was extracted by the phenol-chloroform method from the peripheral blood. PARP-1 Val762Ala polymorphism was identified using polymerase chain reaction-restriction fragments length polymorphism technique. After adjusting for age, tobacco smoking, gender, smoking index, and drinking status, logistic regression analysis demonstrated that CC genotype in PARP-1 Val762Ala polymorphism had an increased risk of lung cancer compared with TT genotype (OR = 1.59, 95 % CI = 1.03 ~ 2.50, P = 0.048), a statistically difference that still existed when merging CC and TC genotypes (OR = 1.56, 95 % CI = 1.03 ~ 2.44, P = 0.042). However, no obvious difference was found between TT and TC (OR = 1.54, 95 % CI = 0.96 ~ 2.44, P = 0.073). Subgroup analysis by histological type indicated that adenocarcinoma patients had higher frequencies of CC or TC+CC genotypes than healthy controls (CC: OR = 1.85, 95 % CI = 1.12 ~ 3.03, P = 0.015; TC+CC: OR = 1.67, 95 % CI = 1.06 ~ 2.63, P = 0.027, respectively), but no statistically significant difference within each genotype in squamous cell carcinoma or small cell lung cancer (all P > 0.05). Our findings support the view that PARP-1 Val762Ala polymorphism may contribute to an increased risk of lung cancer in the Chinese population, especially for adenocarcinoma.

Silencing of the caveolin-1 gene inhibits proliferation and migration of multidrug resistant gastric adenocarcinoma cells

AIM: To investigate the effect of silencing of the caveolin-1 (cav-1) gene on the proliferation and migration of multidrug resistant gastric adenocarcinoma cells (SGC7901/ADR) and to explore the underlying mechanisms.

METHODS: A siRNA specific for the cav-1 gene was transfected into SGC7901/ADR cells using Lipofectamine 2000. The proliferation and migration of SGC7901/ADR cells were detected by MTT assay and transwell assay, respectively. The mRNA expression of cav-1 was determined by RT-PCR. The protein expression of Cyclin D1, Cyclin A1 and Cyclin E was determined by Western blot.

RESULTS: Compared with the control group, the mRNA expression of cav-1 was significantly decreased in SGC7901/ADR cells after transfection (P < 0.05). The proliferation and migration of SGC7901/ADR cells were inhibited significantly after cav-1 silencing. Additionally, the protein expression of Cyclin D1 and Cyclin A1 was obviously inhibited. However, silencing of cav-1 did not affect Cyclin E expression.

CONCLUSION: Silencing of the cav-1 gene inhibits the proliferation and migration of human gastric cancer SGC7901/ADR cells possibly by decreasing the expression of Cyclin D1 and Cyclin A1.

Monoclonal antibody-related drugs for cancer therapy

Much progress has been made during the last few decades in the treatment of malignancies. Many types of cancer cells comprising the tumor mass carry molecular markers that are not expressed or are expressed at much lower levels in normal cells. These findings provide new leads to drug design and development of therapeutic strategies involving monoclonal antibodies (mAbs) or related antibody drugs to treat malignancies. This article reviews recent advances in this targeting approach with a focus on the evolution and current use of prospective antibody drugs as effective ways to treat cancer. Additionally, the development of prospective antibody-drug conjugates will also be briefly described.

Protective autophagy antagonizes oxaliplatin-induced apoptosis in gastric cancer cells

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.

c-Met: A potential therapeutic target for hepatocellular carcinoma

The approval of receptor tyrosine kinase (RTK) targeted agent sorafenib as the first effective drug for the systemic treatment of advanced hepatocellular carcinoma (HCC) represents a milestone in the treatment of this disease. A better understanding of HCC pathogenesis will lead to development of novel targeted treatments. As a typical member of the RTK family, c-Met represents an intriguing target for cancer therapy. The c-Met signaling pathway has been shown to be deregulated and to correlate with poor prognosis in a number of major human cancers. This review discusses the possibility of c-Met as a target in HCC treatment from the following respects: i) c-Met expression and activation profile in HCC, ii) relationship between c-Met and clinicopathologic state and prognosis of HCC, iii) role of c-Met signaling activity in HCC genesis and progression, and iv) strategy of c-Met pathway targeting therapy in HCC treatment.

Prospects for using pre-exposure prophylaxis to control the prevalence of HIV/AIDS in China

Although important progress has been achieved in combating HIV/AIDs over the past 30 years, HIV/AIDs is still a serious threat to today's world. In China, figures on the incidence of this disease have painted a less than optimistic outlook. As the prevailing methods of preventing HIV/AIDS are all partially effective, novel and effective preventive interventions are needed in order to control the spread of the disease. Pre-exposure prophylaxis (PrEP) is one of the most promising prevention strategies and has garnered great attention worldwide. Current clinical trials on the efficacy and safety of this strategy have had some favorable results though major challenges around the world remain. Thus, China has taken an active part in the PrEP study to limit the prevalence of HIV/AIDS. This article describes the status of the PrEP study and discusses the opportunities and challenges encountered when implementing this strategy in China.

Evidence-based research on traditional Japanese medicine, Kampo, in treatment of gastrointestinal cancer in Japan

Gastrointestinal cancer is a great threat to human health in Japan. Conventional anticancer therapies including surgery, radiation, and chemotherapy are the main strategies and play important roles in curing this disease or extending the life of patients with these cancers. On the other hand, patients undergo great suffering induced by these treatments. Kampo, the Japanese traditional medicine, has been used in clinics to reduce side effects and to improve the quality of life of gastrointestinal cancer patients in Japan. In order to testify to the efficacy and safety of these Kampo medicines and to clarify the underlying mechanisms, a number of clinical and basic studies were implemented in the past several decades. These studies suggested the benefits of Kampo medicine as an adjuvant to conventional anti-cancer therapies in treating gastrointestinal cancer. Since the safety and efficacy as well as quality control of traditional medicine have long been focused worldwide, the development course of Kampo medicine may provide reference to other countries in the world.

[Expression of c-Cbl, Cbl-b, and epidermal growth factor receptor in gastric carcinoma and their clinical significance]

BACKGROUND AND OBJECTIVE

c-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.

METHODS

The 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.

RESULTS

The 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.

CONCLUSIONS

Overexpressions 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.

β-Elemene induces apoptosis as well as protective autophagy in human non-small-cell lung cancer A549 cells

OBJECTIVES

β-Elemene, a novel traditional Chinese medicine, has been shown to be effective against a wide range of tumours. In this study, the antitumour effect of β-elemene on human non-small-cell lung cancer (NSCLC) A549 cells and the mechanism involved have been investigated.

METHODS

Cell viability and apoptosis were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Protein expression was assayed by Western blotting. Autophagy was evaluated under fluorescence microscopy and transmission electron microscopy.

KEY FINDINGS

β-Elemene inhibited the viability of A549 cells in a dose-dependent manner. This suppression of cell viability was due to the induction of apoptosis. Further study showed that β-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway, and at the same time it triggered a robust autophagy. The autophagy was characterized by the accumulation of punctate LC3 dots in the cytoplasm, morphological changes, and the increased levels of LC3-II as well as Atg5-Atg12 conjugated proteins. Inhibition of autophagy with chlorochine significantly enhanced the antitumour effect of β-elemene.

CONCLUSIONS

Our data indicated that β-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway in human NSCLC A549 cells, which resulted in apoptosis as well as protective autophagy. A combination of β-elemene with autophagy inhibitor might be an effective therapeutic option for advanced NSCLC.

Ubiquitin ligase c-Cbl is involved in tamoxifen-induced apoptosis of MCF-7 cells by downregulating the survival signals

BACKGROUND

Tamoxifen (TAM) is a nonsteroidal antiestrogen that has been widely used in the treatment of breast cancer through its anti-estrogen activity. Recent studies show that TAM is cytotoxic to both estrogen receptor (ER)-positive and ER-negative cells via the induction of apoptosis. However, the molecular mechanisms of this effect are not well understood. In the present study, we investigated the roles of c-Src, ERK, AKT and c-Cbl ubiquitin ligases during TAM-induced apoptosis of MCF-7 cells.

MATERIAL AND METHODS

MCF-7 cell proliferation and apoptosis were measured by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and flow cytometry, respectively. c-Cbl expression, and the activity of c-Src, ERK, AKT were assayed by Western blotting. Overexpression of the wild and the dominant-negative type of c-Cbl (70Z/Cbl) were achieved by transient transfection of plasmids encoding c-Cbl and 70Z/Cbl, respectively, and were confirmed by Western blotting. Statistical analysis was performed using the t-test, and a p-value <0.05 was considered to be statistically significant.

RESULTS

A high concentration of TAM (25 μM) induced a time-dependent apoptosis of MCF-7 cells. ERK1/2 and AKT were activated during TAM-induced apoptosis. The ERK1/2 inhibitor PD98059, the PI3K/Akt inhibitor LY294002, and the c-Src inhibitor PP2 all enhanced TAM action. Moreover, the ubiquitin ligase c-Cbl was up-regulated during this process. Over-expression of c-Cbl significantly enhanced the apoptosis-inducing effects of TAM, while 70Z/Cbl suppressed the apoptosis-inducing effects of TAM. Further investigation revealed that, overexpression of c-Cbl significantly downregulated the c-Src protein levels and TAM-induced AKT activity. But 70Z/Cbl significantly upregulated TAM-induced ERK and AKT activity.

CONCLUSIONS

This study demonstrates that c-Src, ERK, and AKT played a protective role during TAM-induced apoptosis, and that c-Cbl sensitized MCF-7 cells to TAM by modulating the expression of c-Src, and TAM-induced ERK and AKT activity.

In vitro antitumor effect of the proteasome inhibitor bortezomib on human gastric cancer SGC7901 cells

AIM: To investigate the anti-tumor effect of bortezomib, a proteasome inhibitor, on human gastric cancer SGC7901 cells and to explore possible mechanism involved.

METHODS: Human gastric cancer SGC7901 cells were cultured and treated with different concentrations of bortezomib (1-500 nmol/L) for 24-48 h. Cell viability was determined by MTT assay. Apoptosis was detected by flow cytometry. The cleavage of PARP and caspase-3 and level of phosphor-Akt were determined by Western blot.

RESULTS: Bortezomib inhibited the viability of SGC7901 cells in a dose- and time-dependent manner. The IC₅₀ value at 48 h was 67.39 nmol/L. Treatment with 60 or 180 nmol/L of bortezomib induced cell cycle arrest at G₂/M phase at both 24 and 48 h but induced apoptosis only at 48 h. The cleavage of caspase-3 and PARP was observed in cells treated with 60 or 180 nmol/L of bortezomib for 48 h. Treatment with bortezomib for 48 h down-regulated the level of phosphor-Akt in SGC7901 cells.

CONCLUSION: Bortezomib induced apoptosis and cell cycle arrest at G₂/M phase by inhibiting the activity of the PI3K/Akt signaling pathway in human gastric cancer SGC7901 cells.

Treatment with β-elemene inhibits ERK activation and down-regulates GST-π expression in human gastric cancer cell line SGC7901/Adr

AIM: To investigate the effect of treatment with β-elemene on the activation of extracellular signal-regulated kinase (ERK) and expression of glutathione transferase-π (GST-π) in human gastric cancer cell line SGC7901/Adr.

METHODS: After SGC7901/Adr cells were treated with different concentrations of β-elemene for different durations, cell proliferation was measured by MTT assay, and protein expression was detected by Western blot. All experimental data were analyzed with the SPSS 13.0 software package.

RESULTS: β-elemene inhibited the proliferation of SGC7901/Adr cells in a time-dependent manner. The half maximal inhibitory concentrations of β-elemene at 24, 48, and 72 h in SGC7901/Adr cells were 53.48, 28.78 and 14.78 mg/L, respectively. In untreated control cells, ERK was basically phosphorylated. Treatment with β-elemene (50 mg/L) for 24 h significantly decreased the expression of phosphorylated ERK and GST-π in SGC7901/Adr cells.

CONCLUSION: β-elemene could inhibit the activation of the ERK signaling pathway and thereby down-regulate the expression of GST-π in SGC7901/Adr cells.

Role of PI3K/Akt and MAPK/ERK pathways in gastric cancer exosome-mediated promotion of tumor cell proliferation

AIM: To investigate the effect of gastric cancer exosomes on homologous tumor cell proliferation and to evaluate the role of PI3K/Akt and MAPK/ERK pathways in this process.

METHODS: Exosomes were isolated and purified from human gastric cancer MGC803 cells by serial centrifugation and sucrose gradient ultracentrifugation and observed by electron microscopy. Cell proliferation was measured by MTT assay, and protein expression was assayed by Western blot.

RESULTS: Gastric cancer exosomes had a characteristic saucer-like shape that was limited by a lipid bilayer, and their diameter ranged from 30 to 100 nm. CD9 and TSG101 were abundantly distributed on the surface of exosomes. Gastric cancer exosomes significantly increased MGC803 and SGC7901 cell proliferation in a time- and dose-dependent manner. Treatment with exosomes up-regulated the expression of phosphorylated Akt and ERK in a time-dependent manner.

CONCLUSION: Gastric cancer exosomes promote homologous tumor cell proliferation possibly by activating the PI3K/Akt and MAPK/ERK pathways.

Protective autophagy inhibits 5-FU-induced apoptosis in human gastric cancer cell line MGC803

AIM: To investigate whether 5-fluorouracil (5-FU) induces autophagy in human gastric cancer cell line MGC803 and to identify the role of autophagy in 5-FU -induced cell apoptosis.

METHODS: After cultured MGC803 cells were treated with 5-FU, cell proliferation was measured using MTT assay; cell apoptosis was determined by flow cytometry; protein expression was detected by Western blot; and autophagy was observed by fluorescent microscopy.

RESULTS: The concentration of 5-FU inducing a 50% inhibition of cell proliferation (IC₅₀) was 2.07 mg/L ± 1.14 mg/L in MGC803 cells. After treatment with 2 and 5 mg/L 5-FU for 48 h, the rates of cell apoptosis were 22.46% ± 3.21% and 32.27% ± 4.52%, respectively. Autophagy, characterized by an increase in the number of punctate LC3 dots and the level of LC3-II protein, was observed in cells treated with 5-FU. The activity of the PI3K/Akt/mTOR pathway was inhibited by 5-FU treatment. Inhibition of autophagy with chlorochine significantly enhanced 5-FU -induced apoptosis (P < 0.05).

CONCLUSION: 5-FU-induced protective autophagy prevents MGC803 cells from apoptosis. Combination therapy with 5-FU and autophagy inhibitors may be a promising therapeutic strategy for gastric cancer.

Role of tyrosine kinase Src in gastric cancer exosome-mediated promotion of tumor cell proliferation

AIM: To investigate the effect of gastric cancer exosomes on tumor cell proliferation and to evaluate the role of tyrosine kinase Src in this process.

METHODS: Exosomes were isolated and purified from gastric cancer SGC7901 cells by serial centrifugation and sucrose gradient ultracentrifugation and observed by electron microscopy. Cell proliferation was measured by MTT assay. Protein expression was assayed by Western blot.

RESULTS: Gastric cancer exosomes had a characteristic saucer-like shape that was limited by a lipid bilayer, and their diameter ranged from 30 to 100 nm. CD9 and TSG101 were abundant on the surface of exosomes. Gastric cancer exosomes significantly increased SGC7901 cell proliferation in a time- and dose-dependent manner. Compared with control cells, the proliferation of cells treated with 200 and 400 mg/L exosomes for 72 h were increased to 138% and 144%, respectively (both P < 0.01). The expression of phosphorylated Src in SGC7901 cells was up-regulated in a time- and dose-dependent manner after treatment with exosomes.

CONCLUSION: Gastric cancer exosomes promote tumor cell proliferation possibly by activating tyrosine kinase Src.

Bortezomib synergizes TRAIL-induced apoptosis in gastric cancer cells

Background/Aims Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as a newly identified biological agent has shown promising antitumor effects in a wide range of cancers. However, gastric cancer cells are less sensitive than other cancer cells to TRAIL-induced apoptosis.Here, we combined TRAIL with bortezomib, a proteasomal inhibitor to induce apoptosis in three gastric cancer cell lines.Methods After the cells were treated with TRAIL and/or bortezomib, the cell viability, apoptosis and cell cycle distribution were examined. The levels of death receptors and the mitochondrial membrane potential were also detected. The expression of apoptosis-associated proteins was determined by Western blot.Results Bortezomib at low concentration significantly(P<0.05) enhanced the cytotoxic effect of TRAIL by enhancing apoptosis as well as cell cycle arrest at G2/M phase. The enhancement of efficiency of TRAIL by bortezomib involved up-regulation of death receptor 4 and 5, as well as reduction of the mitochondrial membrane potential. Further study showed that combined treatment with TRAIL and bortezomib down-regulated anti-apoptotic protein cIAP-1, and over expression of cIAP-1 significantly(P\0.05) reduced the synergistic effect between TRAIL and bortezomib.Conclusions Bortezomib synergizes TRAIL-induced apoptosis in human gastric cancer cells. The synergistic effect between these two drugs is associated with up-regulation of death receptors and down-regulation of cIAP-1.The combination of TRAIL and bortezomib might be an effective regimen for the treatment of advanced gastric cancer.

Oxaliplatin enhances TRAIL-induced apoptosis of gastric cancer BGC823 cells

AIM: To determine whether there is a synergistic effect between oxaliplatin and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in inducing the apoptosis of gastric cancer BGC823 cells.

METHODS: After BGC823 cells were cultured and treated with TRAIL and/or oxaliplatin, cell proliferation was measured using MTT assay; cell apoptosis was determined by flow cytometry after propidium iodide staining; and the distribution of lipid rafts and death receptors 4 (DR4) on cell membrane was analyzed by immunofluorescence staining with anti-cholera toxin B subunit, anti-DR4 antibody and rhodamine-conjugated fluorescent secondary antibody.

RESULTS: After BGC823 cells were treated with 1-1 000 µg/L TRAIL for 24 h, the reduced rates of cell proliferation did not exceed 20%. Treatment with 100 µg/L TRAIL for 24 h induced about 10% inhibition of cell proliferation and 4.12% ± 1.26% cell apoptosis. After BGC823 cells were treated with 1-50 mg/L oxaliplatin for 24 h, it was found that the half maximal inhibitory concentration (IC₅₀) was 37.36 mg/L ± 8.12 mg/L. Treatment with oxaliplatin (38 mg/L, IC₅₀ dose) plus TRAIL resulted in a dramatic increase in cell apoptosis when compared to treatment with TRAIL alone (19.83% ± 4.21% vs 40.42% ± 5.78%, P < 0.05). TRAIL at a concentration of 100 µg/L did not induce obvious lipid raft aggregation or DR4 clustering. Oxaliplatin (38 mg/L) significantly promoted lipid raft aggregation and DR4 clustering and induced the co-localization of DR4 and lipid rafts. Treatment with oxaliplatin and TRAIL for 24 h also induced DR4 clustering into aggregated lipid rafts.

CONCLUSION: Oxaliplatin enhances TRAIL-induced BGC823 cell apoptosis by clustering DR4 into lipid rafts.

Role of MAPK/ERK signaling pathway in gastric cancer exosome-induced apoptosis of Jurkat T cells

AIM: To investigate the role of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase (ERK) signaling pathway in gastric cancer exosome-induced apoptosis of Jurkat T cells.

METHODS: Gastric cancer exosomes were isolated and purified by serial centrifugation and sucrose gradient ultracentrifugation. The morphology of gastric cancer exosomes was observed by electron microscopy. Cell apoptosis was determined by propidium iodide staining and flow cytometry. The expression of caspase-3 and -8 and p-ERK was assayed by Western blot.

RESULTS: Gastric cancer exosomes, ranging in diameter from 30 to 100 nm, had a characteristic saucer-like shape that was limited by a lipid bilayer. These exosomes induced Jurkat T cell apoptosis in a time- and dose-dependent manner. Activation of caspase-3 and -8 and down-regulation of p-ERK expression were noted in exosome-induced apoptosis of Jurkat T cells.

CONCLUSION: Gastric cancer exosomes induce apoptosis of Jurkat T cells possibly by inhibiting the MAPK/ERK pathway.

Bortezomib enhances the sensitivity of gastric cancer cells to TRAIL-induced apoptosis by inhibiting the PI3K/Akt pathway

AIM: To investigate the effect of bortezomib on TRAIL-induced apoptosis in human gastric cancer cells, and to elucidate the role of the phosphoinositide 3-kinases (PI3K)/Akt signaling pathway in TRAIL-induced apoptosis of gastric cancer cells.

METHODS: Human gastric cancer MGC803 cells were cultured and treated with TRAIL and/or bortezomib. Cell viability was determined by MTT assay. Apoptosis was detected by flow cytometry. Caspase cleavage and the level of phosphor-Akt were determined by Western blot.

RESULTS: Cells were treated with either 20 or 50 nmol/L bortezomib, or 100 μg/L TRAIL for 24 h, or pretreated with bortezomib for 2 h followed by exposure to TRAIL for an additional 24 h. Compared with cells treated with TRAIL alone, cell viability was obviously lower and apoptosis rate was obviously higher in cells co-treated with TRAIL and 50 nmol/L bortezomib (cell viability: 35.1% ± 2.7% vs 71.0% ± 4.3%, P < 0.01; apoptosis rate: 31.3% ± 2.0% vs 8.2% ± 0.8%, P < 0.01). Pretreatment with 20 nmol/L bortezomib did not enhance the sensitivity of cells to TRAIL-induced apoptosis. TRAIL engagement led to PI3K/Akt activation. Bortezomib blocked the activation of PI3K/Akt signaling and enhanced the sensitivity of cells to TRAIL-induced apoptosis.

CONCLUSION: Bortezomib enhances TRAIL-induced apoptosis by blocking the activation of PI3K/Akt signaling pathway in human gastric cancer MGC803 cells.

The role of cbl family of ubiquitin ligases in gastric cancer exosome-induced apoptosis of Jurkat T cells

BACKGROUND. Exosomes are nanometer-sized vesicles with immunomodulatory functions, which are released by a diverse range of living cells. Although recent studies have shown that tumor-derived exosomes can suppress the function of T cells, the molecular mechanisms are not well understood. In the present study, we investigated the role of the Casitas B lineage lymphoma (cbl) family of ubiquitin ligases in gastric cancer exosome-induced apoptosis of Jurkat T cells. MATERIALS AND METHODS. By serial centrifugation and sucrose gradient ultracentrifugation, we isolated and purified the exosomes from gastric cancer SGC7901 cells, and identified them by electron microscopy and Western blotting. Cell apoptosis was detected using propidium iodide staining. Western blotting and RT-PCR was exploited to evaluate the expression of proteins and mRNA, respectively. RESULTS. Gastric cancer exosomes induced Jurkat T cell apoptosis in a time- and dose-dependent manner and activated caspases 3, 8 and 9. The expression of Cbl-b and c-Cbl was up-regulated during exosome-induced apoptosis of cells. Meanwhile, exosomes induced ubiquitination of the p85 subunit of phosphoinositide 3-kinase (PI3K) and reduced downstream Akt activity. Inhibition of proteasome led to partial restoration of Akt activity and cell apoptosis. DISCUSSION AND CONCLUSIONS. The Cbl family of ubiquitin ligases might be involved in regulation of exosome-induced apoptosis of Jurkat T cells by increasing PI3K proteasome degradation, inactivation of PI3K/Akt signaling, thus mediating some effects of caspase activation.

[Effects of Bufalin on SYK and CBL family proteins in induction of HL-60 cell apoptosis]

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.

Reversal effect of PI3-K inhibitor LY294002 on P-glycoprotein-mediated multidrug resistance of human leukemia cell line K562/DNR and gastric cancer cell line SGC7901/ADR

BACKGROUND AND OBJECTIVE

Phosphatidylinositol-3-kinase/protein kinase B (PI3-K/Akt) signaling pathway plays an important role in cell survival. This study was to explore the reversal effect of PI3-K inhibitor LY294002 on p-glycoprotein (P-gp)-mediated multidrug resistance in human leukemia cell line K562/DNR and gastric cancer cell line SGC7901/ADR.

METHODS

The cells were divided into simple drug-treated groups and LY294002 pretreated groups: the former groups received treatment of daunorubicin (DNR), adriamycin (ADR), vincristine (VCR) and etoposide (VP-16), respectively; the latter groups received pretreatment of LY294002 before drug treatment. Trypan blue dye exclusion method and MTT assay were used to detect the drug sensitivity of K562/DNR and SGC7901/ADR cells, and the effect of LY294002 on the drug resistance. The expression of P-gp and phosphorylated Akt (p-Akt) in K562/DNR, SGC7901/ADR and their parental cell lines K562 and SGC7901 was detected by Western blot. Intracellular drug accumulation was measured by flow cytometry (FCM).

RESULTS

LY294002 pretreatment significantly decreased the 50% inhibition concentration (IC(50)) of DNR, ADR, VCR and VP-16 for K562/DNR cells, with reverse efficiencies of 72.4%, 64.9%, 60.4% and 52.8%. In SGC7901/ADR cells, the similar result was obtained with a reverse efficiency of 31.0%. LY294002 pretreatment partially inhibited the expression of p-Akt and P-gp, and promoted the intracellular accumulation of DNR and ADR in K562/DNR and SGC7901/ADR cells, respectively.

CONCLUSION

LY294002 could partially reverse multidrug resistance in K562/DNR and SGC7901/ADR cells in vitro via inhibiting PI3-K/Akt pathway.

[The influence of bortezomib on HL-60 cell function induced by all-trans retinoic acid plus bufalin and its mechanism]

OBJECTIVE

To investigate changes in the adherent ability, the expression of adhesion related proteins Pyk2 and paxillin during HL-60 cells differentiation into granulocyte-monocyte induced by low-dose (LD) bufalin in combination with all-trans retinoic acid (ATRA), and to explore the effects of bortezomib on cellular adhesion and the expression of Pyk2 and paxillin.

METHODS

The expression of CD11b was detected by flow cytometry, cellular adherence ability by MTT assay, and the expressions of Pyk2, paxillin and tubulin by Western blot.

RESULTS

The combination of 5 nmol/L bufalin and 30 nmol/L ATRA induced HL-60 cells differentiation in a time-dependent manner, the percentages of CD11b positive cells treated for 2 d and 4 d being (20.0 +/- 2.8)% and (75.0 +/- 5.3)%, respectively, with the increasing of cellular adherence ability. Meanwhile the expressions of Pyk2 and Paxillin were also up-regulated in a time-dependent manner. Bortezomib suppressed HL-60 cell adhesion in a dose-dependent manner. At concentrations of 1 nmol/L and 10 nmol/L the adherence level were (7.8 +/- 0.1)% and (5.3 +/- 0.3)%, respectively, with down-regulation of Pyk2 but not Paxillin.

CONCLUSION

Pyk2 is involved in the regulation of cellular adherence function. Bortezomib might inhibit HL-60 cells adhension function by down-regulation of Pyk2 expression.

Dynamic of modernizing traditional Chinese medicine and the standards system for its development

This article reviewed the process of Traditional Chinese Medicine's modernization on a global scale. This process is motivated by the potential need for traditional medicine as a result of health transitions and increasing drug R&D based on know-how from TCM. The established standards system for modern medicine serves as a basic model yet has limitations in terms of comprehensively evaluating TCM. Spurred by policy committments, research to provide supplements suited to TCM's features and principles is underway. Advanced and interdisciplinary technology and methodology is expected to play an essential role in TCM development.

China-Japan enhance joint research cooperation for drug discoveries and development: News from CJMWDDT 2007 in Jinan, China

Viral hepatitis is currently a major global cause of morbidity and mortality. In some Asian countries like China and Japan, Hepatitis B and C in particular are the most common extremely infectious diseases and are likely to develop into liver cirrhosis. Furthermore, statistics indicate that patients with liver cirrhosis resulting from hepatitis B and C have an increased risk of developing hepatocellular carcinoma (HCC). Scientists have worked tirelessly to find curative therapeutic strategies to control chronic hepatitis and liver cirrhosis, accompanied by improvements in public health and living conditions. China's Shandong University and the University of Tokyo in Japan previously established a longterm cooperative relationship. Cooperative programs include co-training of postgraduates, exchanges of visiting scholars, academic symposia, and a bilateral international joint research program. Some substantive progress has been made as a result of bilateral endeavors. For instance, the Shandong University China-Japan Cooperation Center for Drug Discovery & Screening (SDU-DDSC) has enhanced to serve as an important platform for further close cooperation. At the same time, the International Advancement Center for Medicine & Health Research (IACMHR) - "Drug Discoveries and Therapeutics" and International Research and Cooperation Association for Bio & Socio-Sciences Advancement (IRCA-BSSA) - "BioScience Trends" were established (Visit http://www.ddtjournal.com and http://www.biosciencetrends.com ). The first China-Japan conference on new drug discoveries and therapeutics (CJMWDDT 2007) was recently held in Jinan, China May 27-29, 2007, which provided opportunities for further communication and cooperation and increased knowledge of new drug research and clinical cures for hepatitis. Financially supported by the National Natural Science Foundation of China (NSFC) and the Japan Society for the Promotion of Science (JSPS), the conference covered a wide range of topics in different areas of chemical biology, phytochemistry, medicinal chemistry, and pharmacology and it resulted in informed and genial discussions of hepatitis cures that yielded fruitful results. The active involvement and participation by attendees gave the conference a congenial atmosphere. In the end, an agreement was reached to work together on new drug discovery and effective hepatitis therapeutic strategies, and some agreements have resulted in the creation of handover protocols. The CJMWDDT 2007 was a highly successful scientific event that strengthened and promoted extensive cooperation between China and Japan for the development of new pharmaceutical products and hepatitis cures.

GMP implementation in China: A double-edged sword for the pharmaceutical industry

China's Good Manufacturing Practice (GMP) standards that mainly parallel WHO standards were made compulsory in 2004. However, GMP implementation had both positive as well as negative impacts on the pharmaceutical industry, with negatives including pharmaceutical companies suffering economic hardships, poor execution of GMP standards, and sequent health scares. This report briefly describes the problems with GMP implementation in China.

[Effect of bufalin-inducing apoptosis on Bcl-2 and PKC in HL-60 cells]

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.