p27Kip1 as a prognostic factor in breast cancer: a systematic review and meta‐analysis

The aim of this study was to comprehensively evaluate via a meta‐analysis the association between p27 expression and clinical outcome in breast cancer patients. We conducted a meta‐analysis of 20 studies (n= 6463 patients) that evaluated the correlation between p27 expression and indicators of breast cancer clinical outcome, including overall survival (OS), disease‐free survival (DFS) and relapse‐free survival (RFS). Data pooling was performed by RevMan 4.2. A total of 60% (9 of 15) of the studies showed a significant association between p27 high expression and OS, whereas 25% (2 of 8) and 60% (3 of 5) studies demonstrated a correlation between p27 high expression and DFS and RFS, respectively. The relative risks (RRs) were 1.34 (1.26–1.42) for OS (P < 0.00001), 1.27 (1.10–1.47) for DFS (P= 0.001) and 1.49 (0.92–2.42) for RFS (P= 0.10). In lymph node‐negative breast cancer patients, the RRs for OS and RFS were 1.84 (1.30–2.59; P= 0.0005) and 1.30 (0.20–8.50; P= 0.78), respectively. In lymph node‐positive breast cancer patients, the RRs for OS and RFS were 2.99 (1.77–5.07; P < 0.0001) and 1.49 (0.80–2.77; P= 0.21), respectively. This meta‐analysis indicates that reduced p27 is an independent prognostic factor for poor overall and disease‐free cancer survival.     

The potential of microRNAs as human prostate cancer biomarkers: A meta‐analysis of related studies

Prostate cancer (PC) is a very important kind of male malignancies. When PC evolves into a stage of hormone resistance or metastasis, the fatality rate is very high. Currently, discoveries and advances in miRNAs as biomarkers have opened the potential for the diagnosis of PC, especially early diagnosis. miRNAs not only can noninvasively or minimally invasively identify PC, but also can provide the data for optimization and personalization of therapy. Moreover, miRNAs have been shown to play an important role to predict prognosis of PC. The purpose of this meta‐analysis is to integrate the currently published expression profile data of miRNAs in PC, and evaluate the value of miRNAs as biomarkers for PC. All of relevant records were selected via electronic databases: Pubmed, Embase, Cochrane, and CNKI based on the assessment of title, abstract, and full text. we extracted mean ± SD or fold change of miRNAs expression levels in PC versus BPH or normal controls. Pooled hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS) and recurrence‐free survival (RFS), were also calculated to detect the relationship between high miRNAs expression and PC prognosis. Selected 104 articles were published in 2007‐2017. According to the inclusion criteria, 104 records were included for this meta‐analysis. The pooled or stratified analyze showed 10 up‐regulated miRNAs (miR‐18a, miR‐34a, miR‐106b, miR‐141, miR‐182, miR‐183, miR‐200a/b, miR‐301a, and miR‐375) and 14 down‐regulated miRNAs (miR‐1, miR‐23b/27b, miR‐30c, miR‐99b, miR‐139‐5p, miR‐152, miR‐187, miR‐204, miR‐205, miR‐224, miR‐452, miR‐505, and let‐7c) had relatively good diagnostic and predictive potential to discriminate PC from BPH/normal controls. Furthermore, high expression of miR‐32 and low expression of let‐7c could be used to differentiate metastatic PC from local/primary PC. Additional interesting findings were that the expression profiles of five miRNAs (miR‐21, miR‐30c, miR‐129, miR‐145, and let‐7c) could predict poor RFS of PC, while the evaluation of miR‐375 was associated with worse OS. miRNAs are important regulators in PC progression. Our results indicate that miRNAs are suitable for predicting the different stages of PC. The detection of miRNAs is an effective way to control patient's prognosis and evaluate therapeutic efficacy. However, large‐scale detections based on common clinical guidelines are still necessary to further validate our conclusions, due to the bias induced by molecular heterogeneity and differences in study design and detection methods.     

Interleukin‐8 ‐251A/T gene polymorphism and lung cancer susceptibility: a meta‐analysis

Many studies have examined the association between the interleukin‐8 ‐251T/A ( rs4073 ) gene polymorphism and lung cancer risk in various populations, but the results have been inconsistent. In this meta‐analysis, PubMed was searched for case–control studies published through 01 December 2013. The data were extracted, and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. We assessed six published studies on the association between the interleukin‐8 ‐251T/A polymorphism and lung cancer risk. The included studies yielded a total of 3265 lung cancer cases and 3607 controls. For the homozygous A/A and A allele carriers (T/A + A/A), the pooled ORs for all studies combining 3265 cases and 3607 controls were 1.03 (95% CI = 0.92–1.14; P = 0.235 for heterogeneity) and 1.07 (95% CI = 0.96–1.19; P = 0.245 for heterogeneity) when compared with the homozygous wild‐type genotype (T/T). When the analysis was stratified by ethnicity, significant risks were found among Asians for both the A allele carriers and the homozygous A/A individuals. However, no significant associations were found in non‐Asian populations using any of the genetic models. This meta‐analysis suggests that the interleukin‐8 ‐251A allele confer an increased risk for the development of lung cancer among Asians.     

TGF‐β1 rs1982073 polymorphism contributes to radiation pneumonitis in lung cancer patients: a meta‐analysis

Transforming growth factor beta 1(TGF‐β1) polymorphism was associated with radiation pneumonitis (RP) susceptibility, but their results have been inconsistent. The PubMed and CNKI were searched for case‐control studies published up to Januray 01, 2016 was Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. In this meta‐analysis, we assessed eight publications involving 368 radiation pneumonitis cases and 855 controls of the association between TGF‐β1 T869C (rs1982073) and G915C (rs1800471) polymorphism and RP susceptibility. Our analysis suggested that TGF‐β1 T869C rs1982073 polymorphism was associated with lower RP risk for CT combined CC versus TT model (OR = 0.58, 95% CI = 0.43–0.77). However, for the G915C rs1800471 polymorphism, no association was found between the polymorphism and the susceptibility to RP in GC combined CC versus GG model (OR = 0.82, 95% CI = 0.50–1.35). These results from the meta‐analysis suggest that T869C rs1982073 polymorphism of TGF‐β1 may be associated with RP risk, and there may be no association between G915C polymorphism and RP risk.     

Fisetin induces apoptosis in breast cancer MDA‐MB‐453 cells through degradation of HER2/neu and via the PI3K/Akt pathway

Overexpression of human epidermal growth factor receptor 2 (HER2) is observed in breast cancer. The major snag faced by the human population is the development of chemoresistance to HER2 inhibitors by advanced stage breast cancer cells. Moreover, recent researchers focussed on fisetin as an antiproliferative and chemotherapeutic agent. Therefore, this study was intended to analyze the effects of fisetin on HER2/neu‐overexpressing breast cancer cell lines. Our results depicted that fisetin induced apoptosis of these cells by various mechanisms, such as inactivation of the receptor, induction of proteasomal degradation, decreasing its half‐life, decreasing enolase phosphorylation, and alteration of phosphatidylinositol 3‐kinase/Akt signaling.     

miR‐126 reduces trastuzumab resistance by targeting PIK3R2 and regulating AKT/mTOR pathway in breast cancer cells

MicroRNAs (miRNAs) have been found to play a key role in drug resistance. In the current study, we aimed to explore the potential role of miR‐126 in trastuzumab resistance in breast cancer cells. We found that the trastuzumab‐resistant cell lines SKBR3/TR and BT474/TR had low expression of miR‐126 and increased ability to migrate and invade. The resistance, invasion and mobilization abilities of the cells resistant to trastuzumab were reduced by ectopic expression of miR‐126 mimics. In comparison, inhibition of miR‐126 in SKBR3 parental cells had the opposite effect of an increased resistance to trastuzumab as well as invasion and migration. It was also found that miR‐126 directly targets PIK3R2 in breast cancer cells. PIK3R2‐knockdown cells showed decreased resistance to trastuzumab, while overexpression of PIK3R2 increased trastuzumab resistance. In addition, our finding showed that overexpression of miR‐126 reduced resistance to trastuzumab in the trastuzumab‐resistant cells and that inhibition of the PIK3R2/PI3K/AKT/mTOR signalling pathway was involved in this effect. SKBR3/TR cells also showed increased sensitivity to trastuzumab mediated by miR‐126 in vivo. In conclusion, the above findings demonstrated that overexpression of miR‐126 or down‐regulation of its target gene may be a potential approach to overcome trastuzumab resistance in breast cancer cells.     

Targeting the ROS/PI3K/AKT/HIF‐1α/HK2 axis of breast cancer cells: Combined administration of Polydatin and 2‐Deoxy‐d‐glucose

It is well established that cancer cells depend upon aerobic glycolysis to provide the energy they need to survive and proliferate. However, anti‐glycolytic agents have yielded few positive results in human patients, in part due to dose‐limiting side effects. Here, we discovered the unexpected anti‐cancer efficacy of Polydatin (PD) combined with 2‐deoxy‐D‐glucose (2‐DG), which is a compound that inhibits glycolysis. We demonstrated in two breast cell lines (MCF‐7 and 4T1) that combination treatment with PD and 2‐DG induced cell apoptosis and inhibited cell proliferation, migration and invasion. Furthermore, we determined the mechanism of PD in synergy with 2‐DG, which decreased the intracellular reactive oxygen (ROS) levels and suppressed the PI3K/AKT pathway. In addition, the combined treatment inhibited the glycolytic phenotype through reducing the expression of HK2. HK2 deletion in breast cancer cells thus improved the anti‐cancer activity of 2‐DG. The combination treatment also resulted in significant tumour regression in the absence of significant morphologic changes in the heart, liver or kidney in vivo. In summary, our study demonstrates that PD synergised with 2‐DG to enhance its anti‐cancer efficacy by inhibiting the ROS/PI3K/AKT/HIF‐1α/HK2 signalling axis, providing a potential anti‐cancer strategy.     

Prognostic significance of EZH2 expression in patients with oesophageal cancer: a meta‐analysis

Enhancer of zeste 2 (EZH2), a key component of polycomb repressive complex 2 (PRC2), was of great importance in human cancer pathogenesis. Various studies examined the relationship between EZH2 overexpression with the clinical outcome in patients with digestive cancers, but yielded conflicting results. Electronic databases updated to January 2015 were searched to find relevant studies. A meta‐analysis was conducted with eligible studies which quantitatively evaluated the relationship between EZH2 overexpression and survival of patients with digestive cancers. Survival data were aggregated and quantitatively analysed. We performed a meta‐analysis of 10 studies (n = 1461 patients) that evaluated the correlation between EZH2 overexpression and survival in patients with digestive cancers. Combined hazard ratios suggested that EZH2 overexpression was associated with poor prognosis of overall survival (HR = 1.54, 95% CI: 1.27–1.81) in patients with oesophageal cancer. In the stratified analysis, no significant risks were found among gastric cancer (HR = 0.66, 95% CI: 0.16–1.15) and colorectal cancer (HR = 0.91, 0.63–1.19), indicating that EZH2 was not an indicator of poor prognosis in gastric cancer or colorectal cancer. Enhancer of zeste 2 overexpression indicates a poor prognosis for patients with oesophageal cancer, but not among gastric cancer or colorectal cancer.     

Growth differentiation factor 15 is a promising diagnostic and prognostic biomarker in colorectal cancer

Although various studies have demonstrated that growth differentiation factor 15 (GDF15) might be a potential diagnostic and prognostic marker in colorectal cancer (CRC) patients, the results are inconsistent and the statistical power of individual studies is also insufficient. An original study was conducted to explore the diagnostic and prognostic value of serum GDF15 in CRC patients. We also conducted a meta‐analysis study which aimed to summarize the diagnostic and prognostic performance of serum GDF15 in CRC. We searched PubMed and ISI Web of Knowledge up to 1 November 2014 for eligible studies. In order to explore the diagnostic performance of GDF15, standardized mean difference (SMD) and their 95% confidence intervals (CI) were estimated and receiver‐operating characteristic (ROC) curves were constructed. For prognostic meta‐analysis, study‐specific hazard ratios (HRs) of serum GDF15 for survival were summarized. A total of eight studies were included in the meta‐analyses. Our results revealed that serum GDF15 levels in CRC patients were higher than those in healthy controls (SMD = 1.08, 95% CI: 0.56–1.59, P < 0.001). For discriminating CRC from healthy controls, the AUC of GDF15 was 0.816 (95% CI: 0.792–0.838). The sensitivity and specificity were 58.9% (95% CI: 55.0–62.8) and 92.08% (95% CI: 89.2–94.4), respectively, when a cut‐off value of 1099 pg/ml was established. Besides, higher GDF15 expression level was associated with worse overall survival for CRC patients (pooled HR = 2.09, 95% CI: 1.47–2.96). In conclusion, the present meta‐analysis suggests that serum GDF15 may be a useful diagnostic and prognostic biomarker for CRC.     

Comprehensive analysis of autophagy‐related prognostic genes in breast cancer

Accumulating evidence revealed that autophagy played vital roles in breast cancer (BC) progression. Thus, the aim of this study was to investigate the prognostic value of autophagy‐related genes (ARGs) and develop a ARG‐based model to evaluate 5‐year overall survival (OS) in BC patients. We acquired ARG expression profiling in a large BC cohort (N = 1007) from The Cancer Genome Atlas (TCGA) database. The correlation between ARGs and OS was confirmed by the LASSO and Cox regression analyses. A predictive model was established based on independent prognostic variables. Thus, time‐dependent receiver operating curve (ROC), calibration plot, decision curve and subgroup analysis were conducted to determine the predictive performance of ARG‐based model. Four ARGs (ATG4A, IFNG, NRG1 and SERPINA1) were identified using the LASSO and multivariate Cox regression analyses. A ARG‐based model was constructed based on the four ARGs and two clinicopathological risk factors (age and TNM stage), dividing patients into high‐risk and low‐risk groups. The 5‐year OS of patients in the low‐risk group was higher than that in the high‐risk group (P < 0.0001). Time‐dependent ROC at 5 years indicated that the four ARG–based tool had better prognostic accuracy than TNM stage in the training cohort (AUC: 0.731 vs 0.640, P < 0.01) and validation cohort (AUC: 0.804 vs 0.671, P < 0.01). The mutation frequencies of the four ARGs (ATG4A, IFNG, NRG1 and SERPINA1) were 0.9%, 2.8%, 8% and 1.3%, respectively. We built and verified a novel four ARG–based nomogram, a credible approach to predict 5‐year OS in BC, which can assist oncologists in determining effective therapeutic strategies.     

A population‐averaged approach to diagnostic test meta‐analysis

The meta‐analysis of diagnostic accuracy studies is often of interest in screening programs for many diseases. The typical summary statistics for studies chosen for a diagnostic accuracy meta‐analysis are often two dimensional: sensitivities and specificities. The common statistical analysis approach for the meta‐analysis of diagnostic studies is based on the bivariate generalized linear‐mixed model (BGLMM), which has study‐specific interpretations. In this article, we present a population‐averaged (PA) model using generalized estimating equations (GEE) for making inference on mean specificity and sensitivity of a diagnostic test in the population represented by the meta‐analytic studies. We also derive the marginalized counterparts of the regression parameters from the BGLMM. We illustrate the proposed PA approach through two dataset examples and compare performance of estimators of the marginal regression parameters from the PA model with those of the marginalized regression parameters from the BGLMM through Monte Carlo simulation studies. Overall, both marginalized BGLMM and GEE with sandwich standard errors maintained nominal 95% confidence interval coverage levels for mean specificity and mean sensitivity in meta‐analysis of 25 of more studies even under misspecification of the covariance structure of the bivariate positive test counts for diseased and nondiseased subjects.     

Immunocytochemical detection of prognostic markers in breast cancer; technical considerations

The purpose of this study was to establish a good technical procedure for immunocytochemical (IC) staining of prognostic markers in breast cancer specimens. The influence of various preparation, fixation and storage methods on ER, P53 and Ki-67 IC staining was assessed, using cells of two breast cancer cell lines T47D (ER/P53+) and ZR-75-ER (ER+, P53-). In addition we searched for a suitable transport medium. Depending on the technical procedure, great variations in expression of the tested antigens were found. Cytospins fixed and stored according to the Abbott method gave the best results. Histocon appeared to be the medium of choice. A good concordance of IC and immunohistochemical (IH) results was found when the adopted method was tested on material of 10 breast cancers. This study underlines the importance of quality controlled standardization of cell processing, fixation and storage of fine needle aspiration (FNA) aspirates in order to obtain reproducible and consistent IC results.     

Predictive value of plasma copeptin level for the risk and mortality of heart failure: a meta‐analysis

Epidemiologic studies are inconsistent regarding the association between plasma copeptin level and heart failure (HF). The aim of this study was to perform a meta‐analysis to determine whether high level of copeptin is correlated with incidence of HF and mortality in patients with HF. We searched PUBMED and EMBASE databases for studies conducted from 1966 through May 2016 to identify studies reporting hazard ratio (HR) estimates with 95% confidence intervals (CIs) for the association between plasma copeptin level and HF. A random‐effects model was used to combine study‐specific risk estimates. A total of 13 studies were included in the meta‐analysis, with five studies on the incidence of HF and eight studies on the mortality of patients with HF. For incidence of HF, the summary HR indicated a borderline positive association of high plasma copeptin level with HF risk (HR, 1.60; 95% CI, 0.90–2.85). Furthermore, an increase of 1 standard deviation in log copeptin level was associated with a 17% increase in the risk of incident HF (HR, 1.17; 95% CI, 1.02–1.33). For all‐cause mortality of patients with HF, we also found a significant association between elevated plasma copeptin level and increased mortality of HF (HR, 1.76; 95% CI, 1.33–2.33). Our dose–response analysis indicated that an increment in copeptin level of 1 pmol/l was associated with a 3% increase in all‐cause mortality (HR, 1.03; 95% CI, 1.01–1.05). In conclusion, our results suggest that elevated plasma copeptin level is associated with an increased risk of HF and all‐cause mortality in patients with HF.     

A meta‐analysis of dispersal in butterflies

Dispersal has recently gained much attention because of its crucial role in the conservation and evolution of species facing major environmental changes such as habitat loss and fragmentation, climate change, and their interactions. Butterflies have long been recognized as ideal model systems for the study of dispersal and a huge amount of data on their ability to disperse has been collected under various conditions. However, no single ‘best’ method seems to exist leading to the co‐occurrence of various approaches to study butterfly mobility, and therefore a high heterogeneity among data on dispersal across this group. Accordingly, we here reviewed the knowledge accumulated on dispersal and mobility in butterflies, to detect general patterns. This meta‐analysis specifically addressed two questions. Firstly, do the various methods provide a congruent picture of how dispersal ability is distributed across species? Secondly, is dispersal species‐specific? Five sources of data were analysed: multisite mark‐recapture experiments, genetic studies, experimental assessments, expert opinions, and transect surveys. We accounted for potential biases due to variation in genetic markers, sample sizes, spatial scales or the level of habitat fragmentation. We showed that the various dispersal estimates generally converged, and that the relative dispersal ability of species could reliably be predicted from their relative vagrancy (records of butterflies outside their normal habitat). Expert opinions gave much less reliable estimates of realized dispersal but instead reflected migration propensity of butterflies. Within‐species comparisons showed that genetic estimates were relatively invariable, while other dispersal estimates were highly variable. This latter point questions dispersal as a species‐specific, invariant trait.     

Statin induces inhibition of triple negative breast cancer (TNBC) cells via PI3K pathway

Primary TNBCs are treated as if they were a single disease entity, yet it is clear they do not behave as a single entity in response to current therapies. Recently, we reported that statins might have a potential benefit for TNBCs associated with ets-1 overexpression. The aim of this study is to investigate the role of PTEN loss in the effects of statin on TNBC cells. In addition, we analyze the relationship between AKT downstream pathways and the effects of statin on TNBC cells. We investigated the effect of a statin on TNBC cells and analyzed the association of PI3K pathways using various TNBC cells in terms of PTEN loss and AKT pathways. Simvastatin treatments resulted in decreased cell viabilities in various TNBC cell lines. Compared with PTEN wild-type TNBC cells, PTEN mutant-type TNBC cells showed a decreased response to simvastatin. Expressions of phosphorylated Akt and total Akt showed an inverse relationship with PTEN expression. The TNBC cell lines, which showed increased expression of p-Akt, appeared to attenuate the expression of p-Akt by PTEN loss in simvastatin-treated TNBC cells. The Akt inhibitor, LY294002, augmented the effect of simvastatin on PTEN wild-type TNBC cells. Simvastatin induces inhibition of TNBC cells via PI3K pathway activation.