[Silencing of SLP-2 inhibits the migration and invasion of cervical cancer cells in vitro].

OBJECTIVE: To investigate the effect of SLP-2 silencing on the migration and invasion of human cervical cancer cells and explore the mechanism. METHODS: Small interfering RNA (siRNA) was used to knockdown the expression of SLP-2 in Hela cells and Siha cells. At 48 h after the transfection, the cells were examined for SLP-2 expression with Western blotting, and wound healing assay and Transwell assay were used to evaluate the changes in the cell migration; Matrigel Transwell assay was used to evaluate the changes in the invasion ability of the cells. The expressions of E-cadherin, ß-catenin, vimentin and Twist in Hela and Siha cells following the transfection were detected with Western blotting. RESULTS: Compared with the control cells, siRNA transfection significantly lowered the expression of SLP-2 and suppressed the migration and invasion ability of Hela cells and Siha cells (P < 0.01). Silencing SLP-2 induced obvious up-regulation of epithelial cell phenotype proteins E-cadherin and ß-catenin, down- regulated the expression of interstitial cell phenotype protein vimentin, and lowered the expression of Twist in the cells. CONCLUSIONS: Silencing SLP-2 via siRNA transfection can inhibit epithelial-mesenchymal transition of human cervical cancer cells and lower their migration and invasion abilities possibly in relation with downregulated expression of Twist.

Association between the XRCC1 polymorphisms and clinical outcomes of advanced NSCLC treated with platinum-based chemotherapy: a meta-analysis based on the PRISMA statement.

BACKGROUND: Base excision repair (BER) pathway is a DNA repair pathway that is important in carcinogenesis and in response to DNA-damaging chemotherapy. XRCC1 is one of important molecular markers for BER. So far, the role of XRCC1 polymorphisms with clinical outcomes of advanced NSCLC treated with platinum-based chemotherapy is inconclusive. To explore the relationship between XRCC1 polymorphisms and platinum-based chemotherapy in advanced NSCLC patients, we performed this meta-analysis. METHODS: Crude odds ratios (ORs), Cox proportional hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) were adopted to assess the strength of association between XRCC1 polymorphisms and response rate, Overall survival (OS) and progression free survival (PFS) of advanced NSCLC treated with platinum-based chemotherapy. Q test and I 2 test were used for the assessment of heterogeneity. Subgroup analyses were conducted when heterogeneity exists. Begg's funnel plots and Egger's linear regression test were used to estimate publication bias. Sensitivity analysis was performed to evaluate the stability of the result. RESULTS: A total of 19 studies including 2815 individuals were eligible for the analysis, results showed XRCC1 194Arg allele was negatively associated with the objective response rate relative to 194Trp, and results of homozygous model, dominant model and heterozygous model suggested a gene dosage effect negative correlation between 194Arg allele and objective response rate(ArgArg vs TrpTrp: OR = 0.64(95%CI: 0.44-0.91); ArgArg + TrpArg vs TrpTrp: OR = 0.79(95%CI: 0.57-1.11); TrpArg vs TrpTrp: OR = 1.05(95%CI: 0.73-1.51)). XRCC1 399Gln may indicate favorable overall survival (GlnGln + GlnArg vs ArgArg: HR = 0.65(95%CI: 0.43-0.98)) and favorable PFS (GlnGln vs ArgArg: HR = 0.72(95%CI: 0.48-0.97)) in Asian patients; while in Caucasian patients, XRCC1 399Gln indicated poorer overall survival (GlnGln vs ArgArg: HR = 2.29(95%CI: 1.25-3.33)). CONCLUSIONS: Our results indicated that in NSCLC patients treated with platinum-based regimen, XRCC1 194Arg allele suggest poor objective response rate, the GlnGln genotype of XRCC1 399 suggest poorer overall survival in Caucasian patients, and longer PFS in Asian patients.

MicroRNA-19 triggers epithelial-mesenchymal transition of lung cancer cells accompanied by growth inhibition.

The miR-19 family (miR-19a and miR-19b-1) are key oncogenic components of the miR-17-92 cluster. Overexpression of miR-19 is strongly associated with cancer invasion and metastasis, and poor prognosis of cancer patients. However, the underlying mechanisms remain largely unknown. In the present study, we found that enforced expression of miR-19 including miR-19a and miR-19b-1 triggered epithelial-mesenchymal transition (EMT) of lung cancer cells A549 and HCC827 as shown by mesenchymal-like morphological conversion, downregulation of epithelial proteins (e.g., E-cadherin, ZO-1 (zona occludens 1), and α-catenin), upregulation of mesenchymal proteins (e.g., vimentin, fibronectin 1, N-cadherin, and snail1), formation of stress fibers, and reduced cell adhesion. In addition, enhanced migration and invasion were observed in the cancer cells A549 and HCC827 undergoing EMT. In contrast, silencing of endogenous miR-19 reversed EMT and reduced the migration and invasion abilities of A549 and HCC827 cells. DNA microarray results revealed significant changes of the expression of genes related to EMT, migration, and metastasis of miR-19-expressing A549 cells. Moreover, siRNA-mediated knockdown of PTEN, a target of miR-19, also resulted in EMT, migration, and invasion of A549 and HCC827 cells, suggesting that PTEN is involved in miR-19-induced EMT, migration and invasion of lung cancer cells. Furthermore, lung cancer cells undergoing EMT induced by miR-19 demonstrated reduced proliferation in vitro and in vivo, and enhanced resistance to apoptosis caused by TNF-α. Taken together, these findings suggest that miR-19 triggers EMT, which has an important role in the invasion and migration of lung cancer cells, accompanied by the reduced proliferation of cells.

Periostin, a stroma-associated protein, correlates with tumor invasiveness and progression in nasopharyngeal carcinoma.

Recently, the tumor microenvironment is increasingly recognized as playing an important role in cancer proliferation, invasion, and metastasis. To screen stroma-associated proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, laser capture microdissection (LCM) and quantitative proteomic analysis were employed to assess different protein expression of the stroma between NPC and normal nasopharyngeal mucosa (NNM). In this study, periostin was identified to be significantly up-regulated in NPC stroma compared with NNM stroma and the result was further confirmed by Western blotting. Immunohistochemistry showed that over-expression of periostin was frequently observed in the stroma of NPC and matched lymph node metastases (LNM) compared with the stroma of NNM. Statistical analysis showed over-expression of periostin was significantly associated with advanced clinical stage (P < 0.001) and lymph node metastasis (P < 0.001) and decreased overall survival (P < 0.001) in NPC. Cox regression analysis indicated over-expression of periostin was an independent prognostic factor. Furthermore, ectopic expression of periostin was used to examine its effect on invasiveness of NPC cell in vitro and the result showed that periostin was able to promote invasiveness of NPC cell. In conclusion, periostin expression is correlated with tumor stage, lymph node metastasis, and patient survival. Periostin is a potential biomarker for the differentiation and prognosis of NPC, and it might play an important role in the progression of NPC.

Proteomic analysis of the stroma-related proteins in nasopharyngeal carcinoma and normal nasopharyngeal epithelial tissues.

The stroma surrounding cancer cell population is increasingly recognized as playing an important role in cancer proliferation, invasion, and metastasis. To identify the stromal proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, differences in protein expression of the stroma from NPC and normal nasopharyngeal epithelium tissues (NNET) were assessed using a comparative proteomic approach combined with laser capture microdissection (LCM). LCM was performed to purify stromal cells from NPC and NNET, respectively. Proteins between the pooled microdissected tumor and normal stroma were separated by two-dimensional electrophoresis (2-DE) and differential proteins were identified by mass spectrometry (MS). Sixty differential proteins between normal stroma (NS) and tumor stroma (TS) were identified, and the expression of CapG protein was further confirmed by western blotting and immunohistochemical analysis. Our results will be helpful to study the role of stroma in the NPC carcinogenesis and may provide helpful clues for pathogenesis, early diagnosis, and progression of NPC.

Epidemiology of human influenza A and B viruses in Myanmar from 2005 to 2007.

OBJECTIVES: To perform genetic analysis of influenza A and B viruses in Myanmar from 2005 to 2007 and to determine the prevalence of amantadine-resistant influenza A viruses. METHODS: Phylogenies of the HA and NA genes were analyzed and mutations in M2 that confer resistance to amantadine were screened. RESULTS: Influenza in Myanmar exhibited seasonality, which coincided during the rainy season from June to August. Out of 2,618 samples, 76 influenza A and 132 influenza B viruses were isolated. Phylogenetic analysis showed that in 2005, 11 A/H1N1 isolates formed one cluster with A/Solomon Islands/3/2006 and were amantadine-sensitive strains. One A/H3N2 isolate was amantadine-resistant harboring S31N mutation in M2 and possessing S193F and D225N substitutions in HA (clade N), similar to A/Wisconsin/67/2005. No viruses were isolated in 2006 due to sample storage failure. In 2007, all 64 A/H3N2 isolates were amantadine-resistant and similar to A/Brisbane/10/2007. For influenza B, 3 Yamagata-lineage and 17 Victoria-lineage isolates were detected in 2005 and 112 Victoria-lineage viruses were isolated in 2007. All Victoria-lineage isolates were reassortants possessing NA derived from the Yamagata lineage. CONCLUSION: Continuous surveillance in tropical countries is important for elucidating the seasonality of influenza and determining the molecular characteristics of circulating strains.

Triosephosphate isomerase and peroxiredoxin 6, two novel serum markers for human lung squamous cell carcinoma.

There is currently substantial interest in the identification of human tumor antigens for the diagnosis and immunotherapy of cancer. In our previous study, secretion character and up-regulation of triosephosphate isomerase were observed in lung squamous cell carcinoma, and autoantibodies against triosephosphate isomerase and peroxiredoxin 6 were detected in the sera from over 25% of patients, but in none of the healthy controls. In this study, peroxiredoxin 6 was also found at higher levels in the sera of the patients. Up-regulated triosephosphate isomerase and peroxiredoxin 6 were further validated by enzyme-linked immunosorbent assay in an additional 61 lung squamous cell carcinoma patients, 23 lung adenocarcinoma patients, 56 other types of carcinoma patients, 12 benign lung disease patients, and 59 healthy controls. We found that both triosephosphate isomerase and peroxiredoxin 6 were specifically elevated in lung squamous cell carcinoma sera compared with other groups, with the exception of peroxiredoxin 6 in lung adenocarcinoma patients. Positive correlation between triosephosphate isomerase and distant metastasis was found. At the cut-off point 0.221 (optical density value) on the receiver operating characteristic curve, triosephosphate isomerase could comparatively discriminate lung squamous cell carcinoma from healthy controls with a sensitivity of 65.6%, specificity 84.7%, and total accuracy 75%. For peroxiredoxin 6, at the cut-off point 0.151, it could discriminate the two groups with a sensitivity of 70.5%, specificity 62.7%, and total accuracy 65.8%. With both triosephosphate isomerase and peroxiredoxin 6, discriminant analysis results showed that 68.9% of the lung squamous cell carcinoma and 83.1% of healthy controls were correctly classified. We concluded that triosephosphate isomerase and peroxiredoxin 6 could be markers for lung squamous cell carcinoma.

Identificating 14-3-3 sigma as a lymph node metastasis-related protein in human lung squamous carcinoma.

In this study, we aim to screen metastasis-related proteins in human lung squamous carcinoma (LSC) using laser capture microdissection and a proteomic approach. Twenty two differential proteins were identified from pooled microdissected primary LSC and matched lymph node (LN) metastatic tissues. Expression of the differential protein 14-3-3 sigma was determined by Western blotting and immunohistochemistry. In cell invasion assay, down-regulated 14-3-3 sigma by siRNA increased in vitro invasive ability of HTB-182 and A549 cells, up-regulation of 14-3-3 sigma by pcDNA3.0/14-3-3 sigma decreased in vitro invasive ability of HTB-182 and A549 cells. The data suggest that 14-3-3 sigma is a potential LN metastasis-related protein in LSC, and its dysregulation might play an important role in the LN metastatic process of LSC.

Molecular evolution of human influenza A viruses in a local area during eight influenza epidemics from 2000 to 2007.

A total of 1,041 human influenza A virus isolates were collected at a clinic in Niigata, Japan, during eight influenza seasons from 2000 to 2007. The H3N2 subtype accounted for 75.4% of the isolates, and the rest were H1N1. Extremely high rates of amantadine-resistant strains of H3N2 subtype were observed in 2005/2006 (100%) and 2006/2007 (79.4%), while amantadine-resistant strains of H1N1 subtype were only detected in 2006/2007 (48.2%). Sequence and phylogenetic analysis of the HA1 subunit of the hemagglutinin (HA) gene revealed a characteristic linear trunk in the case of H3N2 viruses and a multi-furcated tree in the case of H1N1 and showed a higher sequence diversity among H3N2 strains than H1N1 strains. Mutations in the HA1 from both subtypes were mainly found in the globular region, and only one-third of these were retained for two or more successive years. Higher diversity of H3N2 viruses was mainly attributable to a higher fixation rate of non-synonymous mutations and to a lesser extent to a higher nucleotide substitution rate than for H1N1. Our analysis showed evidence of four positively selected sites in the HA1 of H1 and five sites in that of H3, four of which were novel. Finally, acquisition or loss of N-glycosylation sites was shown to contribute to the evolution of influenza A virus, especially in the case of H3N2, which had a higher tendency to acquire new glycosylation sites.

[Comparative proteome analysis of laser capture microdissection for purified primary tumor and lymph node metastatic tumor in human lung squamous carcinoma].

OBJECTIVE: To search for lymph node metastasis-associated proteins in human lung squamous carcinoma (hLSC). METHODS: Laser capture microdissection (LCM) was used to purify the target cells from lung primary tumor and matched lymph node metastatic tumor in hLSC. Two-dimensional gel electrophoresis (2-DE) was performed to separate the total proteins of microdissected tumor cells from lung primary tumor and matched lymph node metastatic tumor. PDQuest software was applied to analyze 2-DE images. Differential protein spots between the two types of tissues were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). The expression of Rho-GDIalpha, one of the differential proteins, in the microdissected lung primary tumor cells (LPTC) and matched lymph node metastatic tumor cells (LNMTC) was detected by Western blot. RESULTS: In the present study, 2-DE patterns of microdissected LPTC and LNMTC were established, and 22 differential proteins in the above two tissues were identified, of which 14 were down-regulated in LNMTC and 8 were up-regulated in LNMTC. CONCLUSION: The 22 differential proteins may play some roles in the process of lymph node metastasis in hLSC, and the data provide new clues for metastasis-associated biomarker screen and mechanism of hLSC.

In vivo and in vitro alterations in influenza A/H3N2 virus M2 and hemagglutinin genes: effect of passage in MDCK-SIAT1 cells and conventional MDCK cells.

No mutations were detected in the hemagglutinin gene of influenza A/H3N2 virus isolates from patients undergoing short-term amantadine treatment. However, genetic changes occurred after serial passage in either MDCK or MDCK-SIAT1 cells. Our results showed that only a few mutations were observed in MDCK-SIAT1-passaged isolates in the presence of amantadine.

Effectiveness of oseltamivir treatment among children with influenza A or B virus infections during four successive winters in Niigata City, Japan.

Oseltamivir has been used for treatment of influenza A and B infections, but recent reports documented that it was less active against the latter. We compared the effectiveness of oseltamivir in children between laboratory confirmed influenza A and B over 4 influenza seasons from 2001 to 2005 in a pediatric clinic in Japan. Among 1,848 patients screened, 299 influenza A and 209 influenza B patients were administered oseltamivir (treated groups), and 28 influenza A and 66 influenza B patients were assigned as non-treated groups. The duration of fever, defined as period when patients had the maximum temperature higher than 37.5 degrees C in three-time measurements in a day after the clinic visit, was evaluated among the four groups. In uni-variate analysis, the duration of fever was shorter for treated group than non-treated for influenza A (1.8 +/- 0.9 days vs 2.6 +/- 1.3 days, p < 0.01), but it was not significant for influenza B (2.4 +/- 1.3 days vs 2.8 +/- 1.2 days, p = 0.9). The fever duration was longer in treated influenza B than A patients (p < 0.01). Multi-variate analysis indicated younger age (< 6 years old) and higher body temperature at the clinic visit prolonged the duration of fever. Adjusted average duration of fever indicated that oseltamivir was effective for both types, but more effective on influenza A, and the benefit increased for younger children. Our data provide evidence that oseltamivir is beneficial for influenza infections, but the effectiveness is differed by type and age.

Recurrence and persistence of fever in children who developed amantadine-resistant influenza viruses after treatment.

In recent years, a dramatic increase of amantadine-resistant influenza A has occurred globally, but limited data have been available on the clinical course of patients developed amantadine-resistant viruses. We compared fever reduction between patients who developed resistance or remained sensitive in a pediatric clinic in Niigata, Japan, from 2000 to 2006. A total of 2,802 clinical samples were collected from patients who visited the pediatric outpatient clinic with influenza like illness during the seven influenza epidemic seasons. Patients were divided into 4 groups and analyzed for the fever reduction after amantadine treatment: emerged amantadine-resistant (n = 15); amantadine-sensitive (n = 35); patients administered no antiviral drugs (n = 42); and oseltamivir-treated patients (n = 320), which served as references. All 4 groups showed alleviation of fever up to day 3. The amantadine-resistant group had a significant recurrence of fever on day 4 and/or 5, and as a consequence, the course of illness was prolonged. Considering the pattern of fever, recurrent and persistent patterns were found significantly at higher rates in children with emerged resistant virus compared to other groups, and the age tended to be younger in amantadine-resistant compared to amantadine-sensitive group (3.9 +/- 3.0 vs 6.7 +/- 4.1 years old, n.s.). Therefore, we concluded that younger children were prone to develop amantadine-resistance after treatment and showed a significant recurrence of fever on day 4 and/or 5, and the course of illness was consequently prolonged.

Genetic analysis of influenza A/H3N2 and A/H1N1 viruses circulating in Vietnam from 2001 to 2006.

Influenza A virus has the ability to overcome immunity from previous infections through the acquisition of genetic changes. Thus, understanding the evolution of the viruses in humans is important for the surveillance and the selection of vaccine strains. A total of 30 influenza A/H3N2 viruses and 35 influenza A/H1N1 viruses that were collected in Vietnam from 2001 to 2006 were used to analyze the evolution of the hemagglutinin (HA), neuraminidase (NA), and matrix protein (M) genes. Phylogenetic analysis of individual gene segments revealed that the HA and the NA genes of the influenza A viruses evolved in a sequential way. However, the evolutionary pattern of the M gene proved to be nonlinear and was not linked with that of the HA and NA genes. Genetic drift in HA1 segments, especially in the antigenic sites of A/H3N2 viruses, occurred more frequently in A/H3N2 viruses than it did in A/H1N1 viruses. Two reassortants, one influenza A/H3N2 strain and one A/H1N1 strain, were found on the basis of the phylogenetic analysis of the three genes. While both genetic mutation and reassortment contributed to their evolution, the frequency of genetic changes and reassortment events differs between the two subtypes. As influenza viruses circulate throughout the year, we emphasize the importance of surveillance in tropical and subtropical zones, where the emergence of new strains may be detected earlier than it is in temperate zones.

High prevalence of amantadine-resistance influenza a (H3N2) in six prefectures, Japan, in the 2005-2006 season.

Substantial increase in amantadine-resistant influenza A (H3N2) was reported in Asia and North America in 2005. In this study the frequency and genetic characteristics of amantadine-resistant influenza A, circulated in Japan in 2005-2006 season, were investigated. Isolates were tested by amantadine susceptibility test (TCID(50)/0.2 ml method), and sequencing of the M2 gene to identify mutations that confer resistance. Additionally, the hemagglutinin (HA) and neuraminidase (NA) genes of the viruses were examined. In total, 415 influenza A isolates from six prefectures were screened, and 231 (65.3%) of 354 influenza A (H3N2) were amantadine-resistant, with a serine to asparagine (S31N) change in the M2 gene. However, none of 61 A (H1N1) isolates were resistant. In addition, genetic analyses of the HA gene showed all amantadine-resistant viruses clustered in one (named clade N), possessing specific double mutations at 193, serine to phenylalanine (S193F), and at 225, asparatic acid to asparagine (D225N), and sensitive viruses belonged to another group (clade S). The clinical presentations at the clinical visit did not differ between patients shedding clade N virus and those shedding clade S virus. None of the patients had received previous treatment with amantadine. The results indicate an unusually high prevalence and wide circulation of the amantadine-resistance influenza A (H3N2) in Japan in the 2005-2006 season. These strains had the characteristic double mutations in the HA, in addition to the M2 mutation responsive for resistance. Antiviral resistance monitoring should be intensified and maintained for rapid feedback into treatment strategies, and selection of alternative therapeutic agents.

An off-seasonal amantadine-resistant H3N2 influenza outbreak in Japan.

An off-season community influenza outbreak with high prevalence of amantadine-resistant influenza A/H3N2 occurred during September-October 2005 in Nagasaki Prefecture, Japan, prior to standard influenza circulation. A total of 48 patients with influenza-like-illness (ILI) visited a clinic during the outbreak and 27 (69.2%) of 39 ILI patients were positive for influenza A with rapid antigen testing (Quick Vue Rapid SP Influ). Nine patients were not tested because their symptoms were compatible for influenza without examination. Nasopharyngeal swabs were obtained from 4 of 27 rapid test positive patients, and influenza H3N2 strain was isolated from one out of four. The 4 nasopharyngeal samples were positive for influenza A M2 gene in polymerase chain reaction, and sequencing results all showed identical mutation at position 31, serine to asparagine (S31N) in the gene, conferring amantadine resistance. The phylogenetic tree analysis demonstrated that the hemagglutinin (HA) gene sequences of the 4 samples formed a distinct cluster (named clade N) from recent circulating H3N2 strains, characterized by dual mutations at position 193, serine to phenylalanine (S193F), and at position 225, asparatic acid to asparagine (D225N). Our findings suggested that an off-season community influenza outbreak in Nagasaki was caused by a distinct clade in H3N2 (named clade N), which possessed characteristics of amantadine resistance.

EPIDEMIOLOGICAL STUDY OF INFLUENZA VIRUS INFECTIONS IN YANGON, MYANMAR

Although influenza is a highly contagious acute respiratory illness of global importance, little is known about the disease in tropical countries. An influenza survey was conducted in three sentinel sites in Yangon, Myanmar from September 2003 to December 2004. Throat or nasal swabs were collected from 616 patients with influenza-like symptoms and tested using rapid diagnostic test kits and virus isolation. Influenza B virus was detected in 6 patients from September to October, 2003. Influenza A viruses were detected in 133 patients from June to September, 2004, and the 51 influenza A viruses isolated from 72 specimens were all A⁄H3N2. Influenza virus infections occurred mainly in the rainy season in Yangon, Myanmar, but continuous ongoing influenza surveillance is needed.