Breast-conserving in centrally located breast cancer patients confirmed safe by SEER based study.

BACKGROUND: Due to the lack of high-level data, there is still controversy over the oncological safety of breast conservation in patients with centrally located breast cancer. This study aimed to assess the safety of breast-conserving surgery in patients with centrally located breast cancer based on the data from the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: We collected data for all cases diagnosed with breast cancer who underwent breast-conserving surgery from 2012-2014 in the SEER database. The primary outcome of our study was disease-specific survival (DSS) and overall survival (OS). The PSM was used to eliminate the effects of non-random statistics. Chi-square test, Kaplan-Meier method and Cox proportional hazards regression model on univariate and multivariate analysis were used to analyze the data. RESULTS: Data from 79,214 patients who had undergone breast-conserving surgery were analyzed in this study, including those with breast cancer in the central region (n=3,128) and outside the central region (n=76,086). The DSS of central breast cancer patients and outside the central breast cancer patients was 58.1 months versus 58.0 months (P>0.05), respectively, while the OS of the 2 groups was 58.0 months versus 58.0 months (P>0.05), respectively. CONCLUSIONS: Breast cancer in the central region should not be contraindicated for breast conserving surgery and breast-conserving surgery can benefit a wider range of patients.

Atezolizumab compared to chemotherapy for first-line treatment in non-small cell lung cancer with high PD-L1 expression: a cost-effectiveness analysis from US and Chinese perspectives.

BACKGROUND: The IMpower110 trial revealed that atezolizumab treatment had significantly longer overall survival (OS) than chemotherapy in non-small cell lung cancer (NSCLC) patients with high-programmed death ligand 1 (PD-L1) expression. The purpose of the present study was to estimate the cost-effectiveness of atezolizumab versus platinum-based chemotherapy for first-line treatment in metastatic NSCLC with high PD-L1 expression, from the perspective of US and Chinese payers. METHODS: A partitioned survival model was constructed based on information from the IMpower110 clinical trial to estimate cost-effectiveness of atezolizumab versus chemotherapy as first-line treatment of metastatic NSCLC. Costs were estimated from US and Chinese payer perspectives. The impact of uncertainty was explored by performing one-way and probabilistic sensitivity analyses. RESULTS: In the United States, treatment with atezolizumab was estimated to increase 0.87 quality adjusted life years (QALYs) at a cost of $123,424/QALY. In China, the use of atezolizumab cost an additional $68,489 compared with chemotherapy, yielding an incremental cost-effectiveness ratio (ICER) of $78,936/QALY. Sensitivity analysis indicated that the cost of atezolizumab was the most influential factor in both countries. CONCLUSIONS: In the United States, which had a willingness-to-pay (WTP) threshold of $100,000 to $150,000 per QALY, atezolizumab was a cost-effective strategy for first-line treatment in metastatic NSCLC patients with high PD-L1 expression when compared to chemotherapy. For China, with a WTP threshold of $33,210 per QALY, atezolizumab was not considered good-value treatment for NSCLC, and a price reduction of 52% appeared to be justified.

Association between long non-coding RNA (lncRNA) GAS5 polymorphism rs145204276 and cancer risk.

OBJECTIVE: The long non-coding RNA (lncRNA) growth arrest­specific transcript 5 (GAS5) plays an important role in various tumors, and an increasing number of studies have explored the association of the GAS5 rs145204276 polymorphism with cancer risk with inconclusive results. METHODS: PubMed, Medline, EMBASE, Cochrane databases, and Web of Science were searched, and nine studies involving 6107 cases and 7909 controls were deemed eligible. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the relationship between rs145204276 and cancer risk in six genetic models. RESULTS: The pooled results suggest that the variant allele del was not associated with overall cancer risk. However, the subgroup analysis showed that allele del was significantly associated with a 22% decreased risk of gastrointestinal cancer (OR = 0.78, 95% CI: 0.72-0.85). Both sensitivity analyses and trial sequential analyses (TSA) demonstrated that the subgroup results were reliable and robust. Moreover, False-Positive Report Probability (FPRP) analysis indicated that the results had true significant correlations. CONCLUSION: These findings provide evidence that the GAS5 rs145204276 polymorphism is associated with the susceptibility to gastrointestinal cancer. Further studies with different ethnicities and larger sample sizes are warranted to confirm these results.

Herb-Drug Interaction Potential of Licorice Extract and Paclitaxel: A Pharmacokinetic Study in Rats.

BACKGROUND AND OBJECTIVES: Licorice is the dried roots and rhizomes of Glycyrrhiza uralensis Fisch (Leguminosae), which is often used with paclitaxel to alleviate paclitaxel-induced pain in clinics. However, the herb-drug interaction between licorice and paclitaxel is still unknown. Our study evaluates the effects of oral licorice on the paclitaxel in rats via pharmacokinetic studies. METHODS: A simple and rapid ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to determine paclitaxel in rat. SD rats were randomly divided into 3 groups of 6 animals each as follows: two groups of rats that were pretreated with a daily gavage of licorice (3 g/kg) for 1 or 14 successive days; Control group that was administered distilled water. All rats were then intravenously administered with paclitaxel (3 mg/kg). RESULTS: The results showed that 14 days pretreatment of licorice could decrease the area under the curve (AUC0-t) (from 7483.08 ± 528.78 to 6679.12 ± 266.56 mg/L × h) (P < 0.01), and increase the total clearance (CL) (from 0.36 ± 0.02 to 0.39 ± 0.02 L/h/kg) of paclitaxel (P < 0.01). However, a single co-administration of licorice did not significantly alter the pharmacokinetic parameters of paclitaxel, such as AUC0-t (from 7483.08 ± 528.78 to 7201.24 ± 292.76 mg/L × h) (P > 0.05) and CL (from 0.36 ± 0.02 to 0.36 ± 0.01 L/h/kg) (P > 0.05). CONCLUSIONS: The results will contribute to better use of licorice in the adjunctive therapy and provide information to study the interaction between herbs and chemotherapy.

Endoplasmic Reticulum Stress Promotes Autophagy and Apoptosis and Reduces Chemotherapy Resistance in Mutant p53 Lung Cancer Cells.

BACKGROUND/AIMS: Lung cancer (LC) continues to be one of the most prevalent cancers around the world. During this study we aimed to investigate the involvement of endoplasmic reticulum stress (ERS) in autophagy, apoptosis, and chemotherapy resistance of mutant p53 LC cells. METHODS: Immunohistochemistry was employed to help determine the p53 mutation status of cancer cells from 92 primary LC patients, who were subsequently assigned to either the mutant p53 (n = 39) or wild-type p53 group (n = 53). RESULTS: Mutant p53 cells exhibited increased expression of the C/EBP homologous protein (CHOP), glucose-regulated protein 78 (GRP78), and inositol-requiring enzyme-1α (IRE1α). The Mutant p53 cells were also found to be sensitive to chemotherapy and displayed decreased expression of PI3K, Akt, and mTOR. The mutant p53 cell lines were treated with tunicamycin to induce ERS and rapamycin in order to inhibit mTOR. Both agents increased the expression of CHOP, GRP78, IRE1α, LC3-II/LC3-I, Atg5, Atg7, caspase-3, caspase-12, cleaved caspase-3, cleaved caspase-12, as well as decreases in cell proliferation as well as the expression levels of PI3K, Akt, and mTOR. Enhanced levels of cell apoptosis and reduced chemotherapy resistance were also detected. CONCLUSION: The findings of our study suggest that ERS promotes autophagy and apoptosis, while acting to reduce chemotherapy resistance in mutant p53 LC cells by downregulating the PI3K/Akt/mTOR signaling pathway.

TUSC3 induces autophagy in human non-small cell lung cancer cells through Wnt/ß-catenin signaling.

We investigated the effects of tumor suppressor candidate 3 (TUSC3) on autophagy in human non-small cell lung cancer (NSCLC) cells. A total of 118 NSCLC patients (88 males and 30 females) who underwent surgery at our institute were enrolled in the study. Immunohistochemical analysis revealed that TUSC3 protein expression was lower in NSCLC specimens than adjacent normal tissue. Correspondingly, there was greater methylation of TUSC3 in NSCLC than adjacent normal tissue. After transient transfection of A549 NSCLC cells with constructs designed to up-regulate or down-regulate TUSC3 expression, we analyzed the effects of inhibiting the Wnt pathway (XAV939) and autophagy (chloroquine, CQ) on the behavior of NSCLC cells. We also performed TOP/FOP-Flash reporter assays, MTT assays, Annexin V-FITC/propidium iodide staining, and acridine orange staining to evaluate Wnt/ß-catenin signaling, cell proliferation, apoptosis, and autophagy, respectively. Expression of Wnt/ß-catenin pathway components and autophagy-related proteins was analyzed using qRT-PCR and Western blotting. We found that TUSC3 inhibited cell proliferation and promoted both apoptosis and autophagy in A549 cells. In addition, TUSC3 increased expression of autophagy-related proteins. It also increased expression of Wnt/ß-catenin signaling pathway components and promoted nuclear transfer of ß-catenin, resulting in activation of Wnt/ß-catenin signaling. TUSC3 thus induces autophagy in human NSCLC cells through activation of the Wnt/ß-catenin signaling pathway.

Lysophosphatidic Acid is a Biomarker for Peritoneal Carcinomatosis of Gastric Cancer and Correlates with Poor Prognosis.

BACKGROUND: Peritoneal carcinomatosis (PC) is an important cause of morbidity and mortality among patients with gastric cancer. Thus, it is important to identify an ideal biomarker for PC. METHODS: Plasma and ascites samples were collected from gastric cancer patients with PC and a control group. Lysophosphatidic acid (LPA) levels were tested and analyzed. RESULTS: The plasma LPA levels of gastric cancer patients with PC were significantly higher than those in gastric cancer patients after radical resection (p = 0.046) and healthy volunteers (p < 0.001). Besides, plasma LPA levels were statistically lower after chemotherapy in gastric cancer patients with PC (p = 0.028). Furthermore, the ascites LPA levels were significantly higher in gastric cancer patients with peritoneal carcinomatosis than those in liver cirrhosis patients (p < 0.001). Moreover, ascites LPA levels were statistically lower after intraperitoneal chemotherapy injection than before (p < 0.001). In addition, the plasma LPA levels were significantly associated with serum CA125 levels (p = 0.032) and TNM stage in gastric cancer patients (p = 0.009). Individuals with plasma LPA levels >20,000 ng/mL had significantly worse overall survival (OS) than those with plasma LPA levels <20,000 ng/mL group (p = 0.006). In addition the group with ascites LPA levels >24,000 ng/mL showed significantly worse progression-free survival (PFS) and OS (p < 0.001 in PFS and OS). CONCLUSIONS: This study demonstrated that LPA levels in plasma and ascites may be useful diagnostic biomarkers for PC of gastric cancer and that higher levels are associated with poor prognosis.

Inhibition of microRNA-196a might reverse cisplatin resistance of A549/DDP non-small-cell lung cancer cell line.

We aimed to explore the possible mechanism of microRNA-196a (miR-196a) inhibition and reversion of drug resistance to cisplatin (DDP) of the A549/DDP non-small-cell lung cancer (NSCLC) cell line. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect expression differences of miR-196a in the drug-resistant A549/DDP NLCLC cell line and the parental A549 cell line, and expressions of miR-196a in the A549/DDP NLCLC cell line transfected with miR-196a inhibitor (anti-miR-196a group) and the miR-196a negative control (miR-NC) group and blank group (without transfection). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test was applied in examining the cell viability of A549/DDP cell line before and after transfection. Clonogenic assay was used to detect cell proliferation ability. Flow cytometry was applied in detecting apoptosis rate of assayed tumor cell and rhodamine-123 changes in cells. Western blot was applied in detecting proteins of drug-resistant related gene in A549/DDP cell line. Significantly higher expression of miR-196a was detected in the drug-resistant A549/DDP cell line than that in the parental A549 cell line (P < 0.05). However, miR-196a expression in the anti-miR-196a group decreased obviously compared to that in the blank group and the miR-NC group (both P < 0.05); The value of IC50 in the anti-miR-196a group showed remarkably lower than that in the blank group and the miR-NC group (both P < 0.05); Rh-123 absorbing ability in the anti-miR-196a group increased 2.51 times and 2.49 times respectively compared to that in the blank group and the miR-NC group (both P < 0.05). No statistical differences in the apoptosis rate of A549/DDP cell line in the early stage were found among the three groups (all P > 0.05), but the late-stage apoptosis rate in the anti-miR-196a group was significantly higher than that in the blank group and the miR-NC group (both P < 0.05); The expressions of human multidrug resistance 1 (MDR1), multidrug resistance protein 1 (MRP1), excision repair cross-complementation 1 (ERCC1), survivin, and B cell lymphoma 2 (Bcl-2) decreased significantly while RhoE increased significantly in the anti-miR-196a group than the blank group and the miR-NC group (all P < 0.05). Inhibition of miR-196a could reverse cisplatin resistance of A549/DDP cell lines, which might relate with inhibition of drug efflux, down-regulation of drug-resistant protein expression, cell apoptosis, and cell proliferation suppression.

Identification of integrin ß1 as a prognostic biomarker for human lung adenocarcinoma using 2D-LC-MS/MS combined with iTRAQ technology.

To discover novel lung adenocarcinoma (AdC) biomarkers, isobaric tags for relative and absolute quantitation (iTRAQ)-tagging combined with 2D-LC-MS/MS analysis was used to identify differentially expressed plasma membrane proteins in lung AdC and paired paraneoplastic normal lung tissues (PNLTs) adjacent to tumors. In this study, significant caveolin-1 downregulation and integrin ß1 upregulation was observed in primary lung AdC vs. PNLT. As there has been no report on the association of integrin ß1 with lung AdC, immunohistochemical staining was performed to detect the expression of integrin ß1 in an independent set of archival tissue specimens including 42 cases of PLNT, 46 cases of without lymph node metastasis primary AdC (non-LNM AdC) and 62 cases of LNM AdC; the correlation of their expression levels with clinicopathological characteristics and clinical outcomes were evaluated. Based on the data, upregulation of integrin ß1 was significantly correlated with advanced clinical stage and lymph node metastasis. Integrin ß1 overexpression was significantly associated with advanced clinical stage (P<0.05), lymph node metastasis (P<0.05), increased relapse rate (P<0.05) and decreased overall survival (P<0.05) in AdCs. Cox regression analysis indicated that integrin ß1 overexpression is an independent prognostic factor. The data suggest that integrin ß1 is a potential biomarker for LNM and prognosis of AdC and integrin ß1 upregulation may play an important role in the pathogenesis of AdC.

Evaluation of gene ontology semantic similarities on protein interaction datasets.

BACKGROUND: Because of the importance of protein interactions in organisms, researchers are interested in the functional similarity between interacted proteins. Gene ontology semantic similarity provides a novel way to measure the similarity between gene products, including proteins. Various methods have been proposed for calculating the semantic similarity between GO terms and gene products, therefore evaluating these measurements on protein interaction data is helpful and necessary for related studies. RESULTS: 35 different definitions of GO semantic similarity are evaluated by receiver operating characteristic analysis, information gain and Chi-square on core PPIs of four organisms, human, rat, mouse and fruit fly, from DIP database. CONCLUSIONS: For the identification of interacted proteins, CoutoEnriched is the best definition of the similarity between GO terms, and there is no significant difference between most methods calculating the semantic similarity between two sets of GO terms.

Case-control study of single nucleotide polymorphisms of PSCA and MUC1 genes with gastric cancer in a Chinese.

AIMS: A case-control study of 300 gastric cancer patients and 300 controls was conducted to investigate whether the polymorphisms rs2294008 in PSCA and rs2070803 in MUC1 might be associated with risk of gastric cancer in a Chinese population. METHODS: Single nucleotide polymorphisms (SNPs) were genotyped using the Sequenom MassARRAY platform. RESULTS: The data showed that the rs2294008 TT genotype increased gastric cancer risk to an adjusted odds ratio (OR) of 2.26 (95%CI 1.25-4.07), TC to 1.72 (95%CI 1.23-2.42) and TC/TT to 1.81 (95% CI 1.31-2.50), while the rs2070803 GA genotype was associated with a decrease in risk to an adjusted OR of 0.42 (95% CI 0.28-0.62) and rs2070803 GA / AA to 0.46 (95% CI 0.32-0.67). Further stratification analysis revealed that rs2294008 in PSCA consistently increased risk of both intestinal and diffuse-type gastric cancers. The effect of rs2070803 in MUC1 was noteworthily also consistent with both subtypes. CONCLUSIONS: Our study suggested rs2294008 in the PSCA gene to be associated with increased risk of gastric cancer and rs2070803 in MUC1 to play a protective role in a Chinese population.

Identification of flotillin-1 as a novel biomarker for lymph node metastasis and prognosis of lung adenocarcinoma by quantitative plasma membrane proteome analysis.

To identify a novel lung adenocarcinoma (AdC) biomarker, iTRAQ-tagging combined with 2D LC-MS/MS analysis was used to identify differentially expressed plasma membrane (PM) proteins in primary lung AdCs and paraneoplastic normal lung tissues (PNLTs). As a result, 36 differentially expressed membrane proteins were identified. Two differential PM proteins flotillin-1 and caveolin-1 were selectively validated by Western blotting. As there has been no report on the association of flotillin-1 with lung AdC, immunohistochemistry was further performed to detect the expression of flotillin-1 in the archival tissue specimens including 42 cases of PNLTs, 62 cases of primary lung AdCs with lymph node metastasis (LNM AdCs), and 46 cases of primary lung AdCs without lymph node metastasis (non-LNM AdCs), and the correlation of flotillin-1 expression levels in lung AdCs with clinicopathological features and clinical outcomes were evaluated. The results showed that up-regulation of flotillin-1 expression in lung AdCs was significantly correlated with advanced clinical stage, lymph node metastasis, increased postoperative relapse and decreased overall survival. Cox regression analysis revealed that the expressional level of flotillin-1 was an independent prognostic factor. The data suggest that flotillin-1 is a potential novel biomarker for lymph node metastasis and prognosis of lung AdC, and flotillin-1 up-regulation might play an important role in the pathogenesis of lung AdC.

Identification of heat shock protein 27 as a radioresistance-related protein in nasopharyngeal carcinoma cells.

PURPOSE: To identify the proteins involved in radioresistance in nasopharyngeal cancer (NPC) cells. METHODS: Sublethal ionizing radiation was applied to establish a radioresistant NPC cell line from its parental NPC cell line CNE1. Clonogenic survival assay, cell growth assay and flow cytometry analysis were used to examine the difference of radiosensitivity in the radioresistant CNE1 cells (CNE1-IR) and control CNE1 cells. Comparative proteomics was performed to identify the differential proteins in the two cell lines. Association of HSP27, one of upregulated proteins in CNE1-IR cells, with NPC cell radioresistance was selected for further investigation using antisense oligonucleotides (ASOs), clonogenic survival assay, Hoechst 33258 staining of apoptotic cells and MTT assay of cell viability. RESULTS: Radioresistant NPC cell line CNE1-IR derived from its parental cell line CNE1 was established. Thirteen differential proteins in the CNE1-IR and CNE1 cells were identified by proteomics, and differential expression of HSP27, one of identified proteins, was selectively confirmed by western blot. Inhibition of HSP27 expression by HSP27 ASOs decreased clonogenic survival and cell viability and increased cell apoptosis of CNE1-IR cells after irradiation, that is, enhanced radiosensitivity of CNE1-IR cells. CONCLUSION: The data suggest that HSP27 is a radioresistant protein in NPC cells, and its upregulation may be involved in the NPC radioresistance.

Identification of candidate biomarkers for early detection of human lung squamous cell cancer by quantitative proteomics.

To discover novel biomarkers for early detection of human lung squamous cell cancer (LSCC) and explore possible mechanisms of LSCC carcinogenesis, iTRAQ-tagging combined with two dimensional liquid chromatography tandem MS analysis was used to identify differentially expressed proteins in human bronchial epithelial carcinogenic process using laser capture microdissection-purified normal bronchial epithelium (NBE), squamous metaplasia (SM), atypical hyperplasia (AH), carcinoma in situ (CIS) and invasive LSCC. As a result, 102 differentially expressed proteins were identified, and three differential proteins (GSTP1, HSPB1 and CKB) showing progressively expressional changes in the carcinogenic process were selectively validated by Western blotting. Immunohistochemistry was performed to detect the expression of the three proteins in an independent set of paraffin-embedded archival specimens including various stage tissues of bronchial epithelial carcinogenesis, and their ability for early detection of LSCC was evaluated by receiver operating characteristic analysis. The results showed that the combination of the three proteins could perfectly discriminate NBE from preneoplastic lesions (SM, AH and CIS) from invasive LSCC, achieving a sensitivity of 96% and a specificity of 92% in discriminating NBE from preneoplatic lesions, a sensitivity of 100% and a specificity of 98% in discriminating NBE from invasive LSCC, and a sensitivity of 92% and a specificity of 91% in discriminating preneoplastic lesions from invasive LSCC, respectively. Furthermore, we knocked down GSTP1 in immortalized human bronchial epithelial cell line 16HBE cells, and then measured their susceptibility to carcinogen benzo(a)pyrene-induced cell transformation. The results showed that GSTP1 knockdown significantly increased the efficiency of benzo(a)pyrene-induced 16HBE cell transformation. The present data first time show that GSTP1, HSPB1 and CKB are novel potential biomarkers for early detection of LSCC, and GSTP1 down-regulation is involved in human bronchial epithelial carcinogenesis.

Identification of GLIPR1 tumor suppressor as methylation-silenced gene in acute myeloid leukemia by microarray analysis.

PURPOSE: To identify methylation-silenced genes in acute myeloid leukemia (AML). METHODS: Microarray analyses were performed in AML cell line HL-60 cells exposed to the demethylating agent 5-aza-2dC. The methylation status and expression of glioma pathogenesis-related protein 1 (GLIPR1), one of highly induced genes by demethylation, were further detected in six hematopoietic malignancy cell lines and 260 bone marrow samples from leukemia patients and nonmalignant diseases as control, as well as pre-treated and post-treated bone marrow samples from 24 complete remission AML patients received chemotherapy using MS-PCR, bisulfite DNA sequencing, RT-PCR, and Western blotting. RESULTS: One hundred and nine genes were significantly induced by demethylation in HL-60 cells, 12 genes of which were confirmed by RT-PCR. GLIPR1, a tumor suppressor gene, was frequently methylation-silenced in AML cell lines and AML patients, but not in the other hematopoietic malignancy cell lines and patients. The frequencies of methylation-silenced GLIPR1 in the pre-treatment were significantly higher than those in the post-treatment in complete remission AML patients. CONCLUSION: We identify 109 genes induced by demethylation in HL-60 cells, and demonstrate that GLIPR1 is a methylation-silenced gene in the AML patients, and may serve as a marker for monitoring disease activity during therapy in the AML patients. The data provide the important information for studying the pathogenesis of AML and discovering the target genes of methylating agents.

Impact of lymphatic vessel invasion on survival in curative resected gastric cancer.

BACKGROUND: Lymphatic vessel invasion (LV) has been regarded as a prognostic factor in some solid tumors. The aim was to clarify the impact of lymphatic vessel invasion on survival in curative resected gastric cancer. METHODS: In this retrospective study, we reviewed the records of 1,024 patients who underwent curative resection for gastric cancer. Among all of the studied patients, 285 of them (27.8%) had lymphatic vessel invasion. RESULTS: There were significant differences in tumor size, tumor location, depth of invasion, and lymph node metastasis (LN) between the patients with lymphatic vessel invasion and those without. The 5-year survival rates in patients were 80.1%, 59.2%, 40.9%, and 30.5% for LN-LV-, LN-LV+, LN+LV-, and LN+LV+ group, respectively. Multivariate analysis revealed that age, tumor location, the depth of invasion, and lymph node metastasis were independent prognostic factors for curative resected gastric cancer. Lymphatic vessel invasion was not an independent prognostic factor in node-positive gastric cancer; however, it was true in node-negative gastric cancer. CONCLUSION: Lymphatic vessel invasion is one of the independent prognostic factors for node-negative gastric cancer after curative resection.

Alterations of microRNAs in cisplatin-resistant human non-small cell lung cancer cells (A549/DDP).

ABSTRACT MicroRNAs (miRNAs) are a class of small, noncoding RNAs that posttranscriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. Accumulating evidence suggests that miRNAs may play a role in chemoresistance and may be involved in the modulation of some drug resistance-related pathways in cancer cells. Here, the authors investigated the possible role of miRNAs in the development of drug resistance in lung cancer cell line. The results showed that 14 miRNAs were presented significantly (>2-fold), including up-regulation of 9 miRNAs and down-regulation of 5 miRNAs in A549/DDP cell line, compared with the parental A549 cell line. Up-regulation of miR-138 increased the sensitivity of A549/DDP cells to cisplatin in in vitro drug sensitivity assay, and increased apoptosis assessed by flow cytometry. The authors also found that excision repair cross-complementation group 1 (ERCC1) was negatively regulated by miR-138 and that down-regulation of ERCC1 at the protein level largely correlated with elevated levels of miR-138 in A549/DDP cells. Taken together, these findings suggest that miR-138 could play an important role in the development of cisplatin resistance in non-small cell lung cancer (NSCLC).

Analysis of EGFR signaling pathway in nasopharyngeal carcinoma cells by quantitative phosphoproteomics.

BACKGROUND: The epidermal growth factor receptor (EGFR) is usually overexpressed in nasopharyngeal carcinoma (NPC) and is associated with pathogenesis of NPC. However, the downstream signaling proteins of EGFR in NPC have not yet been completely understood at the system level. The aim of this study was identify novel downstream proteins of EGFR signaling pathway in NPC cells. RESULTS: We analyzed EGFR-regulated phosphoproteome in NPC CNE2 cells using 2D-DIGE and mass spectrometry analysis after phosphoprotein enrichment. As a result, 33 nonredundant phosphoproteins including five known EGFR-regulated proteins and twenty-eight novel EGFR-regulated proteins in CNE2 were identified, three differential phosphoproteins were selectively validated, and two differential phosphoproteins (GSTP1 and GRB2) were showed interacted with phospho-EGFR. Bioinformatics analysis showed that 32 of 33 identified proteins contain phosphorylation modification sites, and 17 identified proteins are signaling proteins. GSTP1, one of the EGFR-regulated proteins, associated with chemoresistance was analyzed. The results showed that GSTP1 could contribute to paclitaxel resistance in EGF-stimulated CNE2 cells. Furthermore, an EGFR signaling network based on the identified EGFR-regulated phosphoproteins were constructed using Pathway Studio 5.0 software, which includes canonical and novel EGFR-regulated proteins and implicates the possible biological roles for those proteins. CONCLUSION: The data not only can extend our knowledge of canonical EGFR signaling, but also will be useful to understand the molecular mechanisms of EGFR in NPC pathogenesis and search therapeutic targets for NPC.

Activation of EGFR promotes squamous carcinoma SCC10A cell migration and invasion via inducing EMT-like phenotype change and MMP-9-mediated degradation of E-cadherin.

EGFR is a potent stimulator of invasion and metastasis in head and neck squamous cell carcinomas (HNSCC). However, the mechanism by which EGFR may stimulate tumor cell invasion and metastasis still need to be elucidated. In this study, we showed that activation of EGFR by EGF in HNSCC cell line SCC10A enhanced cell migration and invasion, and induced loss of epitheloid phenotype in parallel with downregulation of E-cadherin and upregulation of N-cadherin and vimentin, indicating that EGFR promoted SCC10A cell migration and invasion possibly by an epithelial to mesenchymal transition (EMT)-like phenotype change. Interestingly, activation of EGFR by EGF induced production of matrix metalloproteinase-9 (MMP-9) and soluble E-cadherin (sE-cad), and knockdown of MMP-9 by siRNA inhibited sE-cad production induced by EGF in SCC10A. Moreover, both MMP-9 knockdown and E-cadherin overexpression inhibited cell migration and invasion induced by EGF in SCC10A. The results indicate that EGFR activation promoted cell migration and invasion through inducing MMP-9-mediated degradation of E-cadherin into sE-cad. Pharmacologic inhibition of EGFR, MEK, and PI3K kinase activity in SCC10A reduced phosphorylated levels of ERK-1/2 and AKT, production of MMP-9 and sE-cad, cell migration and invasion, and expressional changes of EMT markers (E-cadherin and N-cadherin) induced by EGF, indicating that EGFR activation promotes cell migration and invasion via ERK-1/2 and PI3K-regulated MMP-9/E-cadherin signaling pathways. Taken together, the data suggest that EGFR activation promotes HNSCC SCC10A cell migration and invasion by inducing EMT-like phenotype change and MMP-9-mediated degradation of E-cadherin into sE-cad related to activation of ERK-1/2 and PI3K signaling pathways.