The impact of E-cadherin expression on non-small cell lung cancer survival: a meta-analysis

Meta-analysis of downregulated E-cadherin as a diagnostic biomarker for cervical cancer

OBJECTIVE

Downregulation of E-cadherin function or expression has been implicated in the progression of cervical cancer. This meta-analysis of updated publications was performed to assess the association of expression alteration of E-cadherin with disease severity and then to determine the diagnostic accuracy of E-cadherin in discriminating cervical lesions including cervical intraepithelial neoplasia (CIN) grade 1 (CIN1), CIN grade 2 (CIN2), CIN grade 3 (CIN3), and cervical cancer.

METHODS

The articles published from inception to January 2021 were searched in PubMed, EBSCO, CNKI, and WanFang Database and then evaluated according to the criteria of meta-analysis. The eligible studies were retrieved and further analyzed. A bivariate mixed effects binary regression model was applied to determine pooled effect estimates.

RESULTS

16 studies with 2436 subjects from 7 countries were eligible for this meta-analysis. When compared with CIN1 control, the pooled odds ratios (ORs) with 95% confidence interval (CI) for the association of E-cadherin positivity with CIN2, CIN3, and cervical cancer were 0.34 (95% CI 0.23-0.51), 0.23 (95% CI 0.10-0.54), and 0.10 (95% CI 0.07-0.14), respectively. The pooled sensitivity and specificity for CIN3 or worse were 0.60 (95% CI 0.48-0.70) and 0.82 (95% CI 0.73-0.88) respectively, with the AUC of 0.78 (95% CI 0.74-0.82). Similar performance was found in CIN2 or worse.

CONCLUSION

These findings demonstrated that the loss of E-cadherin protein was associated with worsened cervical lesions. E-cadherin might serve as a promising diagnostic biomarker to facilitate the discrimination of precancerous and cancerous lesions.

LncCDH5-3:3 Regulates Apoptosis, Proliferation, and Aggressiveness in Human Lung Cancer Cells

(1) Lung cancer (both small cell and non-small cell) is the leading cause of new deaths associated with cancers globally in men and women. Long noncoding RNAs (lncRNAs) are associated with tumorigenesis in different types of tumors, including lung cancer. Herein, we discuss: (1) An examination of the expression profile of lncCDH5-3:3 in non-small cell lung cancer (NSCLC), and an evaluation of its functional role in lung cancer development and progression using in vitro models; (2) A quantitative real-time polymerase chain reaction assay that confirms lncCDH5-3:3 expression in tumor samples resected from 20 NSCLC patients, and that shows its statistically higher expression levels at stage III NSCLC, compared to stages I and II. Moreover, knockout (KO) and overexpression, as well as molecular and biochemical techniques, were used to investigate the biological functions of lncCDH5-3:3 in NSCLC cells, with a focus on the cells’ proliferation and migration; (3) The finding that lncCDH5-3:3 silencing promotes apoptosis and probably regulates the cell cycle and E-cadherin expression in adenocarcinoma cell lines. In comparison, lncCDH5-3:3 overexpression increases the expression levels of proliferation and epithelial-to-mesenchymal transition markers, such as EpCAM, Akt, and ERK1/2; however, at the same time, it also stimulates the expression of E-cadherin, which conversely inhibits the mobility capabilities of lung cancer cells; (4) The results of this study, which provide important insights into the role of lncRNAs in lung cancer. Our study shows that lncCDH5-3:3 affects important features of lung cancer cells, such as their viability and motility. The results support the idea that lncCDH5-3:3 is probably involved in the oncogenesis of NSCLC through the regulation of apoptosis and tumor cell metastasis formation.

SATB1 protein is associated with the epithelial‑mesenchymal transition process in non‑small cell lung cancers

Lung cancer is one of the most frequently diagnosed neoplasms and the leading cause of cancer‑related mortality worldwide. Its predominant subtype is non‑small cell lung cancer (NSCLC), which accounts for over 80% of the cases. Surprisingly, the majority of lung cancer‑related deaths are caused not by a primary tumour itself, but by its metastasis to distant organs. Therefore, it becomes especially important to identify the factors involved in lung cancer metastatic spread. Special AT‑rich binding protein 1 (SATB1) is a nuclear matrix protein that mediates chromatin looping and plays the role of global transcriptional regulator. During the past decade, it has received much attention as a factor promoting tumour invasion. In breast, colorectal and prostate cancers, SATB1 has been shown to influence the epithelial‑mesenchymal transition (EMT) process, which is thought to be crucial for cancer metastasis. The aim of this study was to analyse the possible correlations between the expression of SATB1 and major EMT‑associated proteins in NSCLC clinical samples. Additionally, the impact of EMT induction in NSCLC cell lines on SATB1 mRNA expression was also investigated. Immunohistochemistry was used to assess the expression of SATB1, SNAIL, SLUG, Twist1, E‑cadherin, and N‑cadherin in 242 lung cancer clinical samples. EMT was induced by TGF‑β1 treatment in the A549 and NCI‑H1703 lung cancer cell lines. Changes in gene expression profiles were analyzed using real‑time PCR and Droplet Digital PCR. SATB1 expression was positively correlated with the expression of SNAIL (R=0.129; P=0.045), SLUG (R=0.449; P<0.0001), and Twist1 (R=0.264; P<0.0001). Moreover, SATB1 expression significantly increased after in vitro EMT induction in A549 and NCI‑H1703 cell lines. The results obtained may point to the role of SATB1 as one of the regulators of EMT in NSCLC.

Clinicopathological significance and prognostic value of E-cadherin expression in non-small cell lung cancer: A protocol for systematic review and meta-analysis

BACKGROUND

E-cadherin, a calcium-dependent cell adhesion molecule, as an important mediator of adhesion and signaling pathway, plays a key role in maintaining tissue integrity. However, the association of E-cadherin expression with clinicopathological features and prognostic value in non-small cell lung cancer (NSCLC) is still controversial. Therefore, the purpose of the study is to explore the clinicopathological features and prognostic value of E-cadherin expression in non-small cell lung cancer by meta-analysis.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched to collect the studies about expression of E-cadherin and clinicopathological features and prognosis of non-small cell lung cancer. The last search time was May 2020. Stata 15.0 software was used for statistical analysis.

RESULTS

A total of 35 studies were included, of which the results showed that high expression of E-cadherin compared with its low expression, for overall survival, HR = 0.68 (95% CI:0.64-0.73, P < .05); for disease-free survival or progression-free survival, HR = 0.54 (95% CI: 0.44-0.67); low differentiation of lung cancer compared with moderate and high differentiation, OR = 0.40 (95% CI: 0.27-0.58, P < .05); Advanced lung cancer compared with early stage, OR = 0.54 (95% CI: 0.44-0.66, P < .05); lymph node metastasis compared with non-lymph node metastasis, OR = 0.49 (95% CI: 0.31∼0.77).

CONCLUSION

Low expression of E-cadherin is closely related to poor prognosis of patients with NSCLC, promoting tumor staging and lymph node metastasis, inhibiting tumor differentiation as well.

Artesunate inhibits epithelial-mesenchymal transition in non-small-cell lung cancer (NSCLC) cells by down-regulating the expression of BTBD7

In recent years, more and more studies have shown that antiparasitic drugs can affect a variety of biological processes of tumor cells and exhibit a potential anti-tumor activity. Although artesunate (ART), a strong bioactive derivative of artemisinin and widely used clinically against malaria, was found to have an inhibitory effect on tumor cells, it is still unclear whether ART could regulate the tumor malignancy of non-small-cell lung cancer (NSCLC) cells. In this study, we aimed to investigate the effect of ART on migration capacities in NSCLC cell lines of A549 and H1975. Cell migration capacity was remarkably inhibited by ART treatment. The expression of epithelial marker E-cadherin was upregulated, while mesenchymal markers (N-cadherin, vimentin and FN1) were inhibited by ART in both protein and mRNA levels in A549 and H1975 cells, indicating ART could suppress the epidermal interstitial transformation (EMT) of NSCLC cells. Meanwhile, BTBD7 was found highly expressed in tumor tissues of NSCLC patient and associated with poor prognosis. The anti-migration activity of ART was found to be mediated by the inhibition of BTBD7 mRNA expression and was reversed when the cells were transiently transfected with the BTBD7 overexpression plasmid. Our study demonstrated the potent anti-migratory activity of ART, thereby presenting it as a new candidate for clinical therapy in NSCLC.

Overexpression of Raf-1 kinase inhibitor protein inhibits cell invasion and migration in lung cancer cells through suppressing epithelial-mesenchymal transition

Background

Raf-1 kinase inhibitor protein (RKIP) is a small evolutionary conserved protein that was associated with the Raf-MEK-ERK pathway. However, whether RKIP would alter the invasion and metastasis of non-small cell lung cancer (NSCLC) and play the role through suppressing epithelial-mesenchymal transition (EMT) remains to be explored.

Methods

A549 cells were transfected with RKIP-GV141 plasmid for overexpression of RKIP. Colony formation assay and MTT assay were performed to measure the effects of RKIP on the proliferation and cell viability assay of A549 cells. Transwell, Migration Assay and wound healing assay were performed to analyze the effects of RKIP on the invasion and metastasis of A549 cells. E-cadherin and vimentin were measured by Western blot to conform RKIP affects invasion and metastasis of NSCLC via inhibiting EMT.

Results

RKIP is downregulated in NSCLC tissues compared to adjacent normal lung tissues by IHC. Decreased expression of RKIP contributes to poor prognosis in lung adenocarcinoma patients. Age and pTNM stage were independent prognostic factors for adenocarcinoma patients. Overexpression of RKIP reduces the cell viability and limits the proliferation, invasion, and migration of A549 cells in vitro. Wound healing assay showed the degressive ability of metastasis. High expression of E-cadherin and low expression of vimentin indicated that RKIP affects invasion and metastasis of NSCLC via inhibiting EMT.

Conclusions

RKIP is decreased in NSCLC tissues. Overexpression of RKIP in A549 cells would decrease the cellular proliferation, viability, invasion ability, and metastasis ability probably via inhibiting EMT through upregulating E-cadherin expression and downregulating vimentin expression.

Impact of EMT in stage IIIB/IV NSCLC treated with erlotinib and bevacizumab when compared with cisplatin, gemcitabine and bevacizumab

The aim of the present study was to assess the expression of epithelial-mesenchymal transition biomarkers (E-cadherin and vimentin) and their potential significance as prognostic markers in patients with stage IIIB/IV non-squamous non-small cell lung cancer (NSCLC) enrolled in the INNOVATIONS trial, receiving treatment with either erlotinib/bevacizumab (EB) or cisplatin/gemcitabine/bevacizumab (PGB). The tumor tissues of 104 patients were retrospectively analyzed using immunohistochemistry to assess the expression of E-cadherin and vimentin. The distribution between the treatment arms was 46 patients in the EB-arm and 58 in the PGB-arm. Comparing the treatment arms according to E-cadherin and vimentin expression, the analysis revealed that progression-free survival (PFS) was increased in the PGB treatment group when compared with EB treatment in patients with low expression of E-cadherin [hazard ratio (HR)=0.353; 95% confidence interval (CI) 0.189- 0.658; log-rank P=0.0007] and in those with high expression of vimentin [HR=0.276 (95% CI, 0.115- 0.659), log-rank P=0.0021]. In patients that exhibited high E-cadherin and were negative for vimentin, there was no difference in the PFS between the PGB and EB treatment groups. In conclusion, in non-squamous NSCLC with downregulated E-cadherin and upregulated vimentin, the efficacy of chemotherapy with PGB was superior compared with EB; but the same effect was not observed in patients with high E-cadherin and low vimentin. Although increased PFS was observed in patients with PGB treatment compared with EB treatment in the whole analysis populations, in the subgroup of patients with the mesenchymal phenotype, no prognostic or predictive value of either biomarker could be identified. The potential role of bevacizumab in overcoming chemotherapy resistance in the population with the mesenchymal phenotype has to be further explored.

E-Cadherin Loss Accelerates Tumor Progression and Metastasis in a Mouse Model of Lung Adenocarcinoma

Metastatic disease is the primary cause of death of patients with lung cancer, but the mouse models of lung adenocarcinoma do not accurately recapitulate the tumor microenvironment or metastatic disease observed in patients. In this study, we conditionally deleted E-cadherin in an autochthonous lung adenocarcinoma mouse model driven by activated oncogenic Kras and p53 loss. Loss of E-cadherin significantly accelerated lung adenocarcinoma progression and decreased survival of the mice. Kras;p53;E-cadherin mice had a 41% lung tumor burden, invasive grade 4 tumors, and a desmoplastic stroma just 8 weeks after tumor initiation. One hundred percent of the mice developed local metastases to the lymph nodes or chest wall, and 38% developed distant metastases to the liver or kidney. Lung adenocarcinoma cancer cell lines derived from these tumors also had high migratory rates. These studies demonstrate that the Kras;p53;E-cadherin mouse model better emulates the tumor microenvironment and metastases observed in patients with lung adenocarcinoma than previous models and may therefore be useful for studying metastasis and testing new lung cancer treatments in vivo.

Non-coding RNAs as emerging regulators of epithelial to mesenchymal transition in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains a major health problem that patients suffer from around the world. The epithelial to mesenchymal transition (EMT) has attractive roles in increasing malignant potential and reducing sensitivity to conventional therapeutics in NSCLC cells. Meanwhile, it is now evident that non-coding RNAs (ncRNAs), primarily microRNAs and long non-coding RNAs contribute to tumorigenesis partially via regulating EMT. This article briefly summarizes current researches about EMT-related ncRNAs in NSCLC and discusses their crucial roles in the complex regulatory network. Also, the authors will show the evidence that ncRNAs not only contribute to cancer cells migration and invasion, but also take charge of the resistance of chemotherapy, radiotherapy and EGFR-TIKs. Then, we will further discuss the potential of inhibition of EMT via manipulating relevant ncRNAs to change our current treatment of NSCLC patients.

Mechanism of BRG1 silencing in primary cancers

BRG1 (SMARCA4) is a documented tumor suppressor and a key subunit of the SWI/SNF chromatin remodeling complex that is silenced in many cancer types. Studies have shown that BRG1 is mutated in cancer-derived cell lines, which led to the assertion that BRG1 is also mutated in primary human tumors. However, the sequencing of BRG1-deficient tumors has revealed a paucity of mutations; hence, the cause of BRG1 silencing in tumors remains an enigma. We conducted immunohistochemistry (IHC) on a number of tumor microarrays to characterize the frequency of BRG1 loss in different tumor types. We also analyzed BRG1-deficient tumors by sequencing the genomic DNA and the mRNA. We then tested if BRG1 expression could be induced in BRG1-negative cell lines (i.e., that lack mutations in BRG1) after the application of several different epigenetic agents, including drugs that inhibit the AKT pathway. We found that a subset of BRG1-negative cell lines also demonstrated aberrant splicing of BRG1, and in at least 30% of BRG1-deficient tumors, BRG1 expression appeared to be suppressed due to aberrant BRG1 splicing. As the majority of BRG1-deficient tumors lack mutations or splicing defects that could drive BRG1 loss of expression, this suggests that other mechanisms underlie BRG1 silencing. To this end, we analyzed 3 BRG1-deficient nonmutated cancer cell lines and found that BRG1 was inducible in these cell lines upon inhibition of the AKT pathway. We show that the loss of BRG1 is associated with the loss of E-cadherin and up-regulation of Vimentin in primary tumors, which explains why BRG1 loss is associated with a poor prognosis in multiple tumor types.

E-cadherin: Its dysregulation in carcinogenesis and clinical implications

E-cadherin is a transmembrane glycoprotein which connects epithelial cells together at adherens junctions. In normal cells, E-cadherin exerts its tumour suppressing role mainly by sequestering β-catenin from its binding to LEF (Lymphoid enhancer factor)/TCF (T cell factor) which serves the function of transcribing genes of the proliferative Wnt signaling pathway. Despite the ongoing debate on whether the loss of E-cadherin is the cause or effect of epithelial-mesenchymal transition (EMT), E-cadherin functional loss has frequently been associated with poor prognosis and survival in patients of various cancers. The dysregulation of E-cadherin expression that leads to carcinogenesis happens mostly at the epigenetic level but there are cases of genetic alterations as well. E-cadherin expression has been linked to the cellular functions of invasiveness reduction, growth inhibition, apoptosis, cell cycle arrest and differentiation. Studies on various cancers have shown that these different cellular functions are also interdependent. Recent studies have reported a rapid expansion of E-cadherin clinical relevance in various cancers. This review article summarises the multifaceted effect E-cadherin expression has on cellular functions in the context of carcinogenesis as well as its clinical implications in diagnosis, prognosis and therapeutics.

The prognostic implication of slug in all tumour patients - a systematic meta-analysis

BACKGROUND

E-cadherin is an invasion suppressor molecule which counteracts tumour metastasis and progression. Slug, one of the crucial transcriptional repressors of E-cadherin gene, has been widely reported on its prognostic role in patients with carcinoma, but the results are controversial. Thus, it is necessary to conduct a meta-analysis to draw a convincing conclusion.

DESIGN

PubMed, Embase and Web of Science databases were searched for studies published until August 1st, 2015. Studies using immunohistochemistry (IHC) to detect the protein expression level in tumour tissues were set as protein group, while studies applying real-time quantitative polymerase chain reaction (RT-qPCR) to probe mRNA transcriptional level were set as mRNA group. Pooled hazard ratio (HR) and their corresponding 95% confidence interval (95% CI) were extracted to evaluate the prognostic role. Funnel plots, Begg's test and Egger's test were used to evaluate the publication bias. Sensitivity and heterogeneity analysis were also conducted.

RESULTS

The pooled HR of 23 studies in the protein group was 1·85 (95% CI: 1·51-2·28, I(2)  = 55·4%, P = 0·001), including 1·98 ((95% CI: 1·53-2·58, I(2)  = 55·9%, P = 0·004) for overall survival (OS) and 1·46 (95% CI: 1·18-1·82, I(2)  = 52·0%, P = 0·012) for progression-free/ recurrence-free/ disease-free/ cancer-free survival (PFS/RFS/DFS/CFS). The high expression of Slug in the protein group indicated poor prognosis of the tumour patients. However, the pooled HR of 6 studies in the mRNA group was 0·85 (95% CI: 0·48-1·53, I(2)  = 77·2%, P = 0·001), suggesting no statistical significance. Subgroup analysis was performed to avoid heterogeneity caused by tumour types. Besides, publication bias was not observed in all studies except for the mRNA transcription studies.

CONCLUSIONS

The protein expression rather than mRNA transcription of Slug should be considered as a potent biomarker for poor prognosis of tumours, particularly head and neck cancer as well as lung and urinary carcinomas.

The role of SOX-2 on the survival of patients with non-small cell lung cancer

BACKGROUND

Lung cancer is the most commonly diagnosed cancer as well as the leading cause of cancer death worldwide. Observational studies on the prognostic role of SOX-2 in non-small-cell lung cancer (NSCLC) are controversial.

METHODS

To clarify the impact of SOX-2 in NSCLC survival, we performed this meta-analysis that included eligible studies. The combined hazard ratios and their corresponding 95% confidence intervals (95% CI) were calculated in terms of overall survival.

RESULTS

A total of seven studies with 1,944 patients were evaluable for this meta-analysis. The studies were categorized by histology, disease stage and patient race. Our results suggested that SOX-2 overexpression had a favorable impact on survival of patients with NSCLC, the HR (95% CI) was 0.57 (0.48 to 0.65). However, highly significant heterogeneity was detected among these studies (I(2)=76.7%, P=0.000).

CONCLUSIONS

SOX-2 overexpression indicates a favorable prognosis for patients with NSCLC.

[Advances in the molecular mechanisms and prognostic significance of EMT in non-small cell lung cancer]

上皮细胞-间叶细胞转化（epithelial to mesenchymal transition, EMT）不仅在胚胎的发育过程中起着十分重要的作用，还参与非小细胞肺癌（non-small cell lung cancer, NSCLC）的转移过程。近期的研究发现，发生EMT的细胞不仅出现了形态的改变，还出现了相关表型的改变。既往有关EMT发生机制的研究多数是针对其他肿瘤的，因此很有必要研究NSCLC中是否有类似发生机制。随着研究的进展，EMT相关的基础研究逐渐被用于预测NSCLC的预后。本文将对NSCLC中EMT的发生机制及其临床应用的研究进展进行探讨。

Neuroendocrine tumors of the pancreas: a retrospective single-center analysis using the ENETS TNM-classification and immunohistochemical markers for risk stratification

Background

This study was performed to assess the 2006 introduced ENETS TNM-classification with respect to patient survival and surgical approach for patients who underwent surgery for a neuroendocrine tumor of the pancreas (PNET).

Methods

Between 2001 and 2010 38 patients after resection of a PNET were investigated regarding tumor localization and size. Further, patient survival with regards to the new TNM-classification, the operation methods and immunohistochemical markers was analyzed.

Results

The estimated mean survival time of the 38 patients was 91 ± 10 months (female 116 ± 9, male 56 ± 14 months; p = 0.008). The 5-year survival rate was 63.9%. Patient survival differed significantly depending on tumor size (pT1 107 ± 13, pT2 94 ± 16, pT3 44 ± 7 and pT4 18 ± 14 months; P = 0.006). Patients without lymph node metastasis survived significantly longer compared to patients with positive lymph node status (108 ± 9 vs. 19 ± 5 months; P < 0.001). However, survival in patients with and without distant metastasis did not differ significantly (92 ± 11 vs. 80 ± 23 months; P = 0.876). Further, the tumor grading significantly influenced patient survival (G1 111 ± 12, G2 68 ± 12 and G3 21 ± 14 months; P = 0.037).

Conclusions

As part of the TNM-classification especially lymph node status and also tumor size and grading were identified as important factors determining patient survival. Further, gender was demonstrated to significantly influence survival time. If an R0 resection was achieved in patients with distant metastases patient survival was comparable to patients without metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12893-015-0033-1) contains supplementary material, which is available to authorized users.

PD-L1 over-expression and survival in patients with non-small cell lung cancer: a meta-analysis

BACKGROUND

Observational studies on the prognostic role of programmed cell death-ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC) are controversial.

METHODS

To clarify the impact of PD-L1 in NSCLC survival, we performed this meta-analysis that included eligible studies. The combined hazard ratios (HR) and their corresponding 95% confidence intervals (CIs) were calculated in terms of overall survival.

RESULTS

A total of five studies with 877 patients were evaluable for this meta-analysis. Our results suggested that PD-L1 overexpression had a poor impact on survival of patients with NSCLC, the HR (95% CI) was 1.43 (1.24-1.63) overall, 1.51 (1.24-1.7954) in Asian patients, 1.35 (1.08-1.63) in non-Asian patients. Moreover, there was no heterogeneity between the studies.

CONCLUSIONS

PD-L1 overexpression indicates a poor prognosis for patients with NSCLC.

Prognostic value of TTF-1 expression in patients with non-small cell lung cancer: A meta-analysis

BACKGROUND

Observational studies on the prognostic role of thyroid transcription factor 1 (TTF-1) in non-small-cell lung cancer (NSCLC) are controversial.

METHODS

To clarify the impact of TTF-1 in NSCLC survival, we performed this meta-analysis that included eligible studies. The combined hazard ratios and their corresponding 95% confidence intervals were calculated in terms of overall survival.

RESULTS

A total of 17 studies with 2235 patients were evaluable for this meta-analysis. The studies were categorized by histology, disease stage and patient race. Our results suggested that TTF-1 overexpression had a favorable impact on survival of patients with NSCLC, the HR (95% CI) was 0.49 (0.42 to 0.55) overall, 0.46 (0.38-0.54) in Asian patients, 0.52 (0.42-0.63) in non-Asian patients, 0.45 (0.38-0.52) in adenocarcinoma, 0.63 (0.39-0.86) in stage I NSCLC, and 0.43 (0.33-0.53) in stage IIIb-IV NSCLC. The data collected were not sufficient to determine the prognostic value of VEGF in patients with squamous cell lung carcinomas. But there was a high heterogeneity between the studies.

CONCLUSION

TTF-1 overexpression indicates a favorable prognosis for patients with NSCLC, this effect appears also significant when the analysis is restricted in lung AC patients, stage I and stage IIIb-IV NSCLC.

Prognostic role of Twist or Snail in various carcinomas: a systematic review and meta-analysis

BACKGROUND

Twist and Snail are considered as key transcriptional repressors of E-cadherin tightly related to epithelial-to-mesenchymal transition (EMT) and cancer progression. Numerous studies have investigated the prognostic value of Twist and Snail. However, the published results were controversial or even opposite. Our article aimed to evaluate the prognostic role of Twist and Snail in patients with cancer.

DESIGN

A comprehensive literature search of PubMed, Embase and Web of Science was conducted. Pooled hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were assessed to quantify the prognostic role.

RESULTS

The pooled HR with 38 studies for Twist was 2·18 (95% CI: 1·77-2·68, I(2) = 69·8%, P = 0·000) and for Snail with 40 studies was 1·58 (95% CI: 1·33-1·87, I(2) = 70·0%, P = 0·000), suggesting high Twist/Snail expression predicted poor prognosis related to all clinical outcomes. For Twist, the pooled HR for overall survival (OS) was 2·07 (95% CI: 1·63-2·63, I(2) = 72·6%, P = 0·000) and for progression-free/recurrence-free/metastasis-free/disease-free/cancer-free survival (PFS/RFS/MFS/DFS/CFS) was 2·36 (95% CI: 1·76-3·17, I(2) = 65·0%, P = 0·000). For Snail, the pooled HR for OS was 1·63 (95% CI: 1·33-1·99, I(2) = 70·8%, P = 0·000) and for PFS/RFS/MFS/DFS/CFS was 1·54 (95% CI: 1·17-2·02, I(2) = 59·1%, P = 0·001). All of those results were suggesting that high Twist/Snail expression was associated with poor prognosis. Furthermore, when grouped into different types of cancers, the pooled HRs were also calculated for the subgroups. No publication bias was found except studies evaluating all clinical outcomes of Twist (P = 0·006 for Begg's test and 0·006 for Egger's test).

CONCLUSIONS

Elevated Twist or Snail expression in tumour tissue indicated poor prognosis for cancer.

Bioinformatic approaches to augment study of epithelial-to-mesenchymal transition in lung cancer

Bioinformatic approaches are intended to provide systems level insight into the complex biological processes that underlie serious diseases such as cancer. In this review we describe current bioinformatic resources, and illustrate how they have been used to study a clinically important example: epithelial-to-mesenchymal transition (EMT) in lung cancer. Lung cancer is the leading cause of cancer-related deaths and is often diagnosed at advanced stages, leading to limited therapeutic success. While EMT is essential during development and wound healing, pathological reactivation of this program by cancer cells contributes to metastasis and drug resistance, both major causes of death from lung cancer. Challenges of studying EMT include its transient nature, its molecular and phenotypic heterogeneity, and the complicated networks of rewired signaling cascades. Given the biology of lung cancer and the role of EMT, it is critical to better align the two in order to advance the impact of precision oncology. This task relies heavily on the application of bioinformatic resources. Besides summarizing recent work in this area, we use four EMT-associated genes, TGF-β (TGFB1), NEDD9/HEF1, β-catenin (CTNNB1) and E-cadherin (CDH1), as exemplars to demonstrate the current capacities and limitations of probing bioinformatic resources to inform hypothesis-driven studies with therapeutic goals.

Emerging lung cancer therapeutic targets based on the pathogenesis of bone metastases

Lung cancer is the second most common cancer and the leading cause of cancer related mortality in both men and women. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined. It is widely accepted that tumor metastasis is a formidable barrier to effective treatment of lung cancer. The bone is one of the frequent metastatic sites for lung cancer occurring in a large number of patients. Bone metastases can cause a wide range of symptoms that could impair quality of life of lung cancer patients and shorten their survival. We strongly believe that molecular targets (tumor-related and bone microenvironment based) that have been implicated in lung cancer bone metastases hold great promise in lung cancer therapeutics. Thus, this paper discusses some of the emerging molecular targets that have provided insights into the cascade of metastases in lung cancer with the focus on bone invasion. It is anticipated that the information gathered might be useful in future efforts of optimizing lung cancer treatment strategies.

Prognostic and clinicopathological significance of downregulated E-cadherin expression in patients with non-small cell lung cancer (NSCLC): a meta-analysis

Background

Many studies have investigated the prognostic role of E-cadherin in patients with NSCLC; however, the result still remains inconclusive. An up-to data system review and meta-analysis was necessary to give a comprehensive evaluation of prognostic role of E-cadherin in NSCLC.

Methods

Eligible studies were searched in Pubmed, Embase and Web of Science databases. The inclusion criteria were studies that assessed the relationship between E-cadherin expression detected by immunohistochemistry (IHC) and the prognosis or clinicopathological features in patients with NSCLC. Subgroup analysis according to race, percentage of reduced/negative E-cadherin expression, histological type, and sample size were also conducted. Odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) were calculated to examine the risk or hazard association.

Results

A total of 29 studies including 4010 patients were qualified for analysis. The analysis suggested that downregulated E-cadherin expression was significant associated with unfavorable overall survival (OS) and disease-free survival/progression-free survival (DFS/PFS) in patients with NSCLC. Subgroup analysis by race, percentage of reduced/negative E-cadherin expression, sample size also found the significant association in OS. When only the stage I NSCLC were considered, downregulated E-cadherin expression still had an unfavorable impact on OS. Additionally, downregulated E-cadherin expression was significantly associated with differentiation grade, lymphnode metastasis, vascular invasion, and TNM stage.

Conclusion

Downregulated E-cadherin expression detected by IHC seems to correlate with tumour progression and could serve as an important prognostic factor in patients with NSCLC.

VEGF +936C/T and +460C/T gene polymorphisms and oral cancer risk: a meta-analysis

Many studies have examined the association between the VEGF +936C/T (rs833061) and +460C/T (rs3025039) gene polymorphisms and oral cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, we performed a meta-analysis. The PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases were searched for case-control studies that were published up to January 2013. Data were extracted and pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated. Ultimately, six studies were included, comprising 1006 oral cancer cases and 1016 controls. Overall, the pooled OR for VEGF +936 T allele carriers (TC + TT) versus the wild-type homozygotes (CC) was 1.28 (95 % CI 1.04-1.58; P = 0.228 for heterogeneity), the pooled OR for TT versus CC was 1.64 (95 % CI 1.34-1.98; P = 0.315 for heterogeneity), and the pooled OR for the T allele versus the C allele was 1.42 (95 % CI 1.22-1.76; P = 0.286 for heterogeneity). In the stratified analysis by ethnicity, significant risks were found among Caucasians but not Asians. However, there were no associations between VEGF +460C/T and oral cancer risk in only two of the included studies. In conclusion, this meta-analysis demonstrates that the VEGF +936 T allele may be associated with an increased risk of oral cancer, especially among Caucasian populations.

Downregulated E-cadherin expression indicates worse prognosis in Asian patients with colorectal cancer: evidence from meta-analysis

BACKGROUND

Epithelial-mesenchymal transition (EMT) plays a crucial role in the progression and aggressiveness of colorectal carcinoma. E-cadherin is the best-characterized molecular marker of EMT, but its prognostic significance for patients with CRC remains inconclusive.

METHODOLOGY

Eligible studies were searched from the PubMed, Embase and Web of Science databases. Correlation between E-cadherin expression and clinicopathological features and prognosis was analyzed. Subgroup analysis was also performed according to study location, number of patients, quality score of studies and cut-off value.

PRINCIPAL FINDINGS

A total of 27 studies comprising 4244 cases met the inclusion criteria. Meta-analysis suggested that downregulated E-cadherin expression had an unfavorable impact on overall survival (OS) of CRC (n = 2730 in 14 studies; HR = 2.27, 95%CI: 1.63-3.17; Z = 4.83; P = 0.000). Subgroup analysis indicated that low E-cadherin expression was significantly associated with worse OS in Asian patients (n = 1054 in 9 studies; HR = 2.86, 95%CI: 2.13-3.7, Z = 7.11; P = 0.000) but not in European patients (n = 1552 in 4 studies; HR = 1.14, 95%CI: 0.95-1.35, Z = 1.39; P = 0.165). In addition, reduced E-cadherin expression indicated an unfavorable OS only when the cut off value of low E-cadherin expression was >50% (n = 512 in 4 studies; HR = 2.08, 95%CI 1.45-2.94, Z = 4.05; P = 0.000). Downregulated E-cadherin expression was greatly related with differentiation grade, Dukes' stages, lymphnode status and metastasis. The pooled OR was 0.36(95%CI: 0.19-0.7, Z = 3.03, P = 0.002), 0.34(95%CI: 0.21-0.55, Z = 6.61, P = 0.000), 0.49(95%CI: 0.32-0.74, Z = 3.02, P = 0.002) and 0.45(95%CI: 0.22-0.91, Z = 3.43, P = 0.001), respectively.

CONCLUSIONS

This study showed that low or absent E-cadherin expression detected by immunohistochemistry served as a valuable prognostic factor of CRC. However, downregulated E-cadherin expression seemed to be associated with worse prognosis in Asian CRC patients but not in European CRC patients. Additionally, this meta-analysis suggested that the negative threshold of E-cadherin should be >50% when we detected its expression in the immunohistochemistry stain.

Prognostic value of COX-2 expression in patients with non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Cyclooxygenase-2 (COX-2) has been implicated in tumorigenesis and metastasis, and it presumably mediates the proliferation of endothelial cells and promotes vascular permeability. However, the prognostic value of COX-2 overexpression in patients with non-small cell lung cancer (NSCLC) remains controversial.

METHODS

A systematic review of eligible studies with meta-analysis was performed to quantitatively review the correlation of COX-2 overexpression with survival in patients with NSCLC.

RESULTS

We conducted a final analysis of 1,892 patients from 16 studies. The studies were categorized by histology, disease stage, patient race and laboratory techniques used. Combined hazard ratios (HR) suggested that COX-2 overexpression was not associated with a significant impact on survival, the HR (95% CI) was 0.90 (95% CI: 0.76-1.04) overall, 0.99 (0.71-1.26) in Asian patients, 0.87 (0.71-1.03) in non-Asian patients, 0.63 (0.33-0.93) in adenocarcinoma, 1.42 (1.02-1.81) in stage I NSCLC, 0.83 (0.72-1.08) in NSCLC by IHC, 3.28 (1.48-5.13) in NSCLC by RT-PCR.

CONCLUSIONS

COX-2 overexpression seems to have no significant impact on survival of NSCLC patients. However, the statistically significant was found in stage I NSCLC, suggesting that COX-2 expression could be useful at early stages to distinguish those with a worse prognosis.

Key molecular mechanisms in lung cancer invasion and metastasis: a comprehensive review

Lung cancer remains one of the most common and malignant cancers worldwide. It is most often diagnosed at late stages, when it has already presented local invasion and distal metastases. The basic stages of invasion and metastasis involve the detachment of tumor cells from the extracellular matrix, invasion of surrounding tissues and basal lamina, intravasation into the blood stream, survival and transport through the blood stream, migration, arrest and extravasation at a distal site and formation of a metastatic lesion. These steps require fundamental mechanisms such as angiogenesis, degradation of matrix barriers, disruption of cell-cell and cell-matrix adhesion and inducement of cellular motility. Genes that regulate functions like unlimited growth potential, survival, genomic instability, angiogenesis, epithelial to mesenchymal transition and apoptosis evasion, are involved in giving lung cancer tumors invasive and metastatic competence. Improving of understanding of the underlying molecular and cellular mechanisms remains an urgent and essential issue, in order to develop new more effective strategies in preventing and treating lung cancer.