Meta-analysis: clinicopathological and prognostic significance of cyclooxygenase-2 expression on oesophageal squamous cell carcinoma

Oleuropein inhibits esophageal cancer through hypoxic suppression of BTG3 mRNA

Esophageal cancer (EC) is among the severest cancers causing most fatalities around the world with an increasing incidence. Oleuropein exhibits anti-tumor properties in several human cancers. We aimed to investigate the effect of oleuropein in human EC, and to reveal the molecular target involved in EC tumorigenesis. Cell proliferation, migration and invasion assays were performed to assess the effect of oleuropein on EC cells. A xenograft tumor mouse model was utilized to assess the in vivo effect of oleuropein. Hypoxia-inducible factor-1α (HIF1α) and B-cell translocation gene 3 (BTG3) expressions were examined in oleuropein-treated EC cells. The regulatory effect of HIF1α on BTG3 mRNA was evaluated by chromatin immunoprecipitation and luciferase reporter assays. Oleuropein inhibited the growth of EC cells and xenograft EC tumor, as well as inhibiting HIF1α and upregulating BTG3 expressions. BTG3 mRNA expression was under hypoxia inhibition through the HRE in its promoter region. BTG3 knockdown abolished the inhibitory effect of oleuropein on EC cells in vitro, as well as on EC xenograft tumor in vivo. Oleuropein inhibits EC tumorigenesis through hypoxic suppression of BTG3 mRNA, supporting the clinical application of oleuropein, and HIF1α and BTG3 mRNA as potential molecular targets in treatment against EC.

Systematic review: the etiology of esophageal squamous cell carcinoma in low-income settings

Esophageal carcinoma causes over 380 000 deaths per year, ranking sixth worldwide in mortality amongst all malignancies. Globally, the squamous cell subtype is most common and accounts for 80% of esophageal cancers. Nonetheless, esophageal squamous cell carcinoma is much more poorly understood than esophageal adenocarcinoma, including what is driving such high prevalences, why it often presents in young patients, and shows such marked geographical delineations Areas covered: The current literature was searched for articles focusing on aetiopathogenesis of squamous cell esophageal carcinoma via a systematic review, particularly in low-resource settings. This was supplemented by papers of interest known to the authors. Expert commentary: Current putative mechanisms include polycyclic aromatic hydrocarbons, nitrosamines, acetaldehyde, cyclo-oxygenase-2 pathways, androgen and their receptor levels, as well as smoking & alcohol, micronutrient deficiencies and diet, mycotoxins, thermal damage, oral hygiene and microbiotal factors, inhaled smoke, viral infections such as HPV, and chronic irritative states. Etiology is likely multifactorial and varies geographically. Though smoking and alcohol play a predominant role in high-income settings, there is strong evidence that mycotoxins, diet and temperature effects may play an under-recognized role in low and middle-income settings.

Roles of Cyclooxygenase-2 gene -765G > C (rs20417) and -1195G > A (rs689466) polymorphisms in gastric cancer: A systematic review and meta-analysis

BACKGROUND

The roles of cyclooxygenase-2 (COX2) -765G > C (rs20417) and -1195G > A (rs689466) polymorphisms in gastric cancer were intensively analyzed, but the results of these studies were inconsistent. We conducted a meta-analysis and trial sequential analysis to elucidate the associations between these two COX2 polymorphisms and gastric cancer risk.

METHODS

Eligible studies were searched in PubMed, Embase, Cochrane library databases, China National Knowledge Infrastructure, Vip, and Wanfang databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the genetic correlation between COX2 polymorphisms and gastric cancer susceptibility in five genetic models. Trial sequential analysis (TSA) was conducted to estimate whether the evidence of the results is sufficient. Furthermore, their interactions with Helicobacter pylori (H. pylori) or smoking in gastric cancer were also assessed using a case-only method.

RESULTS

The COX2 gene -765G > C polymorphism showed no significant association with gastric cancer susceptibility under all the five genetic models (take the allelic model for example: OR = 1.41, 95% CI: 0.95-2.09) in total analysis, and the stratification analysis by ethnicity indicated a similar association in Caucasian group under four genetic models (allelic model, dominant model, homozygous model, and heterozygous model). But in the subgroup of the Asian population, the -765G > C polymorphism was significantly associated with gastric cancer risk under the same contrast. The COX2 -1195G > A polymorphism showed significant correlation with gastric cancer susceptibility in total analysis, and stratification analysis by ethnicity also revealed a similar association in both Asian and Caucasian groups under the same contrast. Moreover, TSA confirmed such associations. Both H. pylori infection and cigarette smoking interacted with -765 C allele in gastric cancer (OR = 3.79, 95% CI: 1.15-12.43 and OR = 2.48, 95% CI: 1.38-4.48, respectively), but not in -1195 A allele (OR = 1.96, 95% CI: 0.62-6.21, and OR = 1.24, 95% CI: 0.93-1.64, respectively).

CONCLUSIONS

COX2 -765G > C polymorphism may serve as a genetic biomarker of gastric cancer in Asians, but not in Caucasians. COX2 -1195G > A polymorphism may serve as a genetic biomarker of gastric cancer in both Asians and Caucasians. The -765G > C, rather than -1195G > A polymorphism interacted with H. pylori infection or cigarette smoking to increase gastric cancer risk.

Impact of cyclooxygenase-2 over-expression on the prognosis of colorectal cancer patients. An experience from Western Saudi Arabia

OBJECTIVES

To evaluate cyclooxygenase-2 (COX-2) over-expression in colorectal cancer (CRC) and its role in carcinogenesis and prognosis.

METHODS

It was a retrospective study. Archival samples were obtained from Pathology Department at King Fahad Hospital, Madinah, Saudi Arabia, over 11 years' period (January 2006 to December 2017). Samples were analyzed using immunohistochemistry for COX-2 and Ki67 over-expression in 324 CRC patients, 40 cases of colorectal adenomas and 20 cases of normal colonic mucosa.

RESULTS

Cyclooxygenase-2 over-expression was observed in 40% of normal colonic mucosa, 65% of colorectal adenoma and 84.6% of CRC cases. There were no significant correlations between COX-2 over-expression and age, gender, tumor site, or tumor size. However, COX-2 over-expression revealed highly significant correlations with tumor differentiation, lymph node metastasis, lympho-vascular invasion, distant metastasis, advanced stages, and high Ki67 expression. Univariate Kaplan-Meir survival analysis showed that patients with high COX-2 expression had significantly shorter periods of survival. Multivariate analysis by means of the COX-2 regression model revealed that high COX-2 over-expression, AJCC, and Ki67 expression were the only significant independent prognostic indicators.

CONCLUSION

Cyclooxygenase-2 over-expression increases during normal-adenoma-carcinoma sequence, moreover COX-2 over-expression is associated with advanced tumor stage and Ki67 over-expression. These findings suggest a significant role of COX-2 in the carcinogenesis and prognosis of CRC in our study population.

Immunohistochemical prognostic markers of esophageal squamous cell carcinoma: a systematic review

Background

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy, with a high incidence and poor prognosis. In the past several decades, hundreds of proteins have been reported to be associated with the prognosis of ESCC, but none has been widely accepted to guide clinical care. This study aimed to identify proteins with great potential for predicting prognosis of ESCC.

Methods

We conducted a systematic review on immunohistochemical (IHC) prognostic markers of ESCC according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. Literature related to IHC prognostic markers of ESCC were searched from PubMed, Embase, Web of Science, and Cochrane Library until January 30th, 2017. The risk of bias of these original studies was evaluated using the Quality in Prognosis Studies (QUIPS) tool.

Results

We identified 11 emerging IHC markers with reproducible results, including eight markers [epidermal growth factor receptor (EGFR), Cyclin D1, vascular endothelial growth factor (VEGF), Survivin, Podoplanin, Fascin, phosphorylated mammalian target of rapamycin (p-mTOR), and pyruvate kinase M2 (PKM2)] indicating unfavorable prognosis and 3 markers (P27, P16, and E-cadherin) indicating favorable prognosis of ESCC.

Conclusion

Strong evidence supports that these 11 emerging IHC markers or their combinations may be useful in predicting prognosis and aiding personalized therapy decision-making for ESCC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40880-017-0232-5) contains supplementary material, which is available to authorized users.

The prognostic value of cyclooxygenase-2 expression in patients with esophageal cancer: evidence from a meta-analysis

Published studies have investigated the prognostic role of cyclooxygenase-2 (COX-2) expression in patients with esophageal cancer (EC), but the result remains controversial. Thus, this meta-analysis was conducted to comprehensively evaluate the impact of COX-2 expression on the prognostic value in patients with EC. Relevant studies were identified from PubMed, EMBASE, and Web of Science databases. Studies that detected the COX-2 expression by immunohistochemistry and evaluated the relationship between COX-2 expression and overall survival (OS) or clinicopathological parameters were used in our analysis. The summary hazard ratios (HRs) or odds ratios were calculated to assess the risk or hazard association. A total of 25 studies, which included 2,465 patients, were included in our meta-analysis. Our analysis suggested that overexpression of COX-2 was associated with poor OS (HR =1.60, 95% CI =1.32–1.94, P<0.001). Subgroup analyses by race, percentage of high/positive COX-2 expression, histology type, treatment, and sample size all suggested significant association. Moreover, overexpression of COX-2 was significantly associated with depth of invasion, lymph node metastasis, distant metastasis, and TNM stage. This meta-analysis suggested that overexpression of COX-2 might serve as a prognostic biomarker for EC. Large well-designed prospective studies are needed to confirm our conclusion.

Prediagnosis aspirin use and outcomes in a prospective cohort of esophageal cancer patients

BACKGROUND

Esophageal cancer remains associated with poor outcomes, yet little is known regarding factors that influence survival. Aspirin use prior to cancer diagnosis may influence outcomes. We aimed to assess the effects of prediagnosis aspirin use in patients with esophageal cancer.

METHODS

We conducted a prospective cohort study of newly-diagnosed esophageal cancer patients at two tertiary care centers. We assessed history of prediagnosis aspirin use, and prospectively followed patients and assessed mortality, cause of death, and development of metastases.

RESULTS

We enrolled 130 patients, the majority of whom were male (81.5%) and had adenocarcinoma (80.8%). Overall, 57 patients (43.9%) were regular aspirin users. In unadjusted analyses, we found no difference in all-cause mortality between aspirin users and nonusers. In multivariate analyses, prediagnosis aspirin use was not associated with all-cause mortality [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.48-1.57] or esophageal cancer-specific mortality (HR 1.07, 95% CI 0.52-2.21). Prediagnosis aspirin use was associated with a significantly increased risk of interval metastasis (HR 3.59, 95% CI 1.08-11.96).

CONCLUSIONS

In our cohort of esophageal cancer patients, prediagnosis aspirin use was not associated with all-cause or cancer-specific mortality. However, risk of interval metastatic disease was increased among those who took aspirin regularly prediagnosis. Future studies are warranted to assess whether aspirin influences the molecular characteristics of esophageal tumors, with potential prognostic and therapeutic implications.

Overexpression of phospholipase A2 Group IIA in esophageal squamous cell carcinoma and association with cyclooxygenase-2 expression

BACKGROUND

Esophageal cancer is one of the most frequently occurring malignancies and the seventh leading cause of cancer-related deaths in the world. The esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer worldwide.

MATERIALS AND METHODS

Our goal in this study was to detect phospholipase A2 Group IIA (PLA2G2A) and cyclooxygenase-2 (COX-2) immuno-expression in ESCC in a high- risk population in China.

RESULTS

Positive expression of PLA2G2A protein was observed in 57.2% (166/290) of the cases, while COX-2 was found in 257 of 290 samples (88.6%), both PLA2G2A and COX-2 being expressed in 153 cases (52.8%), with a significant agreement (Kappa=0.091, p=0.031).Overexpression of PLA2G2A was significantly correlated with the depth of invasion (p=0.001). Co-expression of PLA2G2A and COX-2 not only significantly correlated with the depth of invasion (p=0.004) but also with TNM stage (p=0.04).

CONCLUSIONS

Our results showed that in patients with ESCC, PLA2G2A overexpression and PLA2G2A co-expression with COX-2 is significantly correlated with advanced stage. The biological role and pathophysiologic regulation of PLA2G2A and COX-2 overexpression in ESCC deserve further investigation.

Esophageal squamous cell carcinoma (ESCC): advance in genomics and molecular genetics

Esophageal cancer is aggressive and has poor prognosis. Esophageal squamous cell carcinoma (ESCC) is histologically the most prevalent type of esophageal cancer and ranked as the sixth leading cause of cancer death worldwide. In recent years, cancer has been widely regarded as genetic disease, as well as epigenetic abnormalities including DNA methylation, histone deacetylation, chromatin remodeling, gene imprinting and noncoding RNA regulation. In this review, we will provide a general overview of genes, proteins and microRNAs that are involved in the development of ESCC, which aims to enhance our understanding of molecular mechanisms implicated in ESCC development and progression.

Forthcoming prognostic markers for esophageal cancer: a systematic review and meta-analysis

BACKGROUND

The incidence of esophageal cancer is rising, and survival rates remain poor. This meta-analysis summarizes five molecular mechanisms of disease progression, which are related to prognosis.

PATIENTS AND METHODS

A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. Original data was abstracted from each study and used to calculate a pooled event rate and 95% confidence interval (95% CI).

RESULTS

Our analysis included five octamer-binding transcription factor 4 (OCT4) studies (564 patients), six sex determining region Y-box 2 (SOX2) studies (336 patients), five oestrogen receptor (ER) studies (367 patients), seven MET or MNNG HOS Transforming gene (c-Met) studies (1,015 patients) and six insulin like growth factor receptor studies (764 patients). Incidence of OCT4 in SCC was 53.60% (95% CI: 0.182-0.857) and the overall hazard ratio for poor clinic outcome was 2.9 (95% CI: 1.843-4.565). The incidence of SOX2 in SCC was 69.2% (95% CI: 0.361-0.899) however, was associated with significant heterogeneity of 90.94%. The prevalence of Oestrogen receptor α and β in SCC were 37.90% (95% CI: 0.317-0.444) and 67.20% (95% CI: 0.314-0.901) respectively. The prevalence of MET in EAC was 33.20% (95% CI: 0.031-0.884) and the incidence of insulin-like growth factor-1 receptor (IGF-1R) in EAC was 67.70% (95% CI: 0.333-0.898).

CONCLUSIONS

Our results show that the status of ER, OCT4 and SOX2 expression correlates with the unfavourable prognosis in patients with esophageal squamous cell carcinoma (ESCC). This study also highlights the potential impact of the IGF-1R on the biology of EAC and the expression of Met was recognised as a significant prognostic factor. Our data supports the concept of IGF axis, ER, Met, OCT4 and SOX2 inhibition as (neo-) adjuvant treatment.

Cyclooxygenase-2 expression is associated with poor overall survival of patients with gastric cancer: a meta-analysis

BACKGROUND

Cyclooxygenase-2 (COX-2) is believed to be involved in gastric carcinogenesis. However, it is still controversial whether COX-2 expression can be regarded as a prognostic factor for gastric cancer patients.

AIM

To obtain a more accurate relationship between COX-2 overexpression and prognosis in gastric cancer by meta-analysis.

METHOD

Relevant articles published up to May 2013 were searched by use of several keywords in electronic databases. Separate hazard ratio (HR) estimates and 95 % confidence intervals (95 % CI) for COX-2 overexpression and overall survival (OS) and disease-free survival (DFS) with gastric cancer were extracted. Combined HR with 95 % CI was calculated by use of Stata11.0 software to estimate the size of the effect. Publication bias testing and sensitivity analysis were also performed.

RESULTS

A total of 27 studies which included 3,891 gastric cancer patients were combined in the final analysis. Combined results suggested that COX-2 overexpression was associated with an unfavorable OS (HR 1.58, 95 % CI 1.36-1.84) but not DFS (HR 1.15, 95 % CI 0.93-1.43) among patients with gastric cancer. Publication bias was absent. Sensitivity analysis suggested that the results of this meta-analysis were robust.

CONCLUSIONS

The results of this meta-analysis suggest that high COX-2 expression may be an independent risk factor for poor OS of patients with gastric cancer. More large prospective studies are now needed to further clarify the prognostic value of COX-2 expression for DFS in gastric cancer.

Quantitative assessment of the association of COX-2 (Cyclooxygenase-2) immunoexpression with prognosis in human osteosarcoma: a meta-analysis

Background

Numerous studies examining the relationship between Cyclooxygenase-2 (COX-2) immunoexpression and clinical outcome in osteosarcoma patients have yielded inconclusive results.

Methods

We accordingly conducted a meta-analysis of 9 studies (442 patients) that evaluated the correlation between COX-2 immunoexpression and clinical prognosis (death). Pooled odds ratios (OR) and risk ratios (RR) with 95% confidence intervals (95% CI) were calculated using the random-effects or fixed-effects model.

Results

Meta–analysis showed no significant association between COX-2 positivity and age, gender, tumor location, histology, stage, metastasis or 90% necrosis. Conversely, COX-2 immunoexpression was associated with overall survival rate (RR=2.12; 95% CI: 1.10–3.74; P=0.009) and disease-free survival rate (RR=1.63; 95% CI: 1.17–2.28; P=0.004) at 2 years. Sensitivity analysis performed by omitting low quality studies showed that the pooled results were stable.

Conclusions

COX-2 positivity was associated with a lower 2-year overall survival rate and disease-free survival rate. COX-2 expression change is an independent prognostic factor in patients with osteosarcoma.

Targeted treatments for metastatic esophageal squamous cell cancer

Squamous cell carcinoma, one of the two major sub-types of esophageal carcinomas, constitutes the great majority of tumors in the upper and middle third of the organ. Declining in incidence in western countries, it continues to be a significant public health problem in the far east. Targeted treatments are novel therapies introduced in the clinical therapeutic armamentarium of oncology in the last 10-15 years. They represent a rational way of treating various cancers based on their molecular lesions. Although no such agent has been approved so far for the treatment of esophageal squamous cell carcinomas (ESCC), several are in clinical trials and several others have displayed pre-clinical activity that would justify the efforts and risks of pursuing their clinical development in this disease. This paper discusses some of these targeted agents in more advanced development in metastatic ESCC, as well as some promising drugs with pre-clinical or initial clinical data in the disease.

Prognostic significance of COX-2 immunohistochemical expression in colorectal cancer: a meta-analysis of the literature

Background

Cyclooxygenase-2 (COX-2) is believed to be an important enzyme in the pathogenesis of colorectal cancer (CRC). Correlations between the expression of COX-2 with tumor growth and distant metastasis have become an issue; thus, attention has been paid to COX-2 as a prognostic factor. Various studies examined the relationship between COX-2 immunohistochemistry (IHC) overexpression with the clinical outcome in patients with colorectal cancer, but yielded conflicting results. The prognostic significance of COX-2 overexpression in colorectal cancer remains controversial.

Methods

Electronic databases updated to October 2012 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between COX-2 overexpression and survival of patients with colorectal cancer. Survival data were aggregated and quantitatively analyzed.

Results

We performed a meta-analysis of 23 studies (n  =  4567 patients) that evaluated the correlation between COX-2 overexpression detected by IHC and survival in patients with colorectal cancer. Combined hazard ratios suggested that COX-2 overexpression had an unfavorable impact on overall survival (OS) (HR [hazard ratio]  =  1.193, 95% CI [confidence interval]: 1.02 ∼ 1.37), but not disease free survival (DFS) (HR  =  1.25, 95% CI: 0.99 ∼ 1.50) in patients with colorectal cancer.

Conclusions

Cox-2 overexpression in colorectal cancer detected by IHC appears to have slightly worse overall survival. However, the prognostic value of COX-2 on survival in colorectal cancer still needs further large-scale prospective trials to be clarified.

Hypoxia activates the cyclooxygenase-2-prostaglandin E synthase axis

Hypoxia-inducible factors (HIFs), in particular HIF-1alpha, have been implicated in tumor biology. However, HIF target genes in the esophageal tumor microenvironment remain elusive. Gene expression profiling was performed upon hypoxia-exposed non-transformed immortalized human esophageal epithelial cells, EPC2-hTERT, and comparing with a gene signature of esophageal squamous cell carcinoma (ESCC). In addition to known HIF-1alpha target genes such as carbonic anhydrase 9, insulin-like growth factor binding protein-3 (IGFBP3) and cyclooxygenase (COX)-2, prostaglandin E synthase (PTGES) was identified as a novel target gene among the commonly upregulated genes in ESCC as well as the cells exposed to hypoxia. The PTGES induction was augmented upon stabilization of HIF-1alpha by hypoxia or cobalt chloride under normoxic conditions and suppressed by dominant-negative HIF-1alpha. Whereas PTGES messenger RNA (mRNA) was negatively regulated by normoxia, PTGES protein remained stable upon reoxygenation. Prostaglandin E(2) (PGE(2)) biosynthesis was documented in transformed human esophageal cells by ectopic expression of PTGES as well as RNA interference directed against PTGES. Moreover, hypoxia stimulated PGE(2) production in a HIF-1alpha-dependent manner. In ESCC, PTGES was overexpressed frequently at the mRNA and protein levels. Finally, COX-2 and PTGES were colocalized in primary tumors along with HIF-1alpha and IGFBP3. Activation of the COX-2-PTGES axis in primary tumors was further corroborated by concomitant upregulation of interleukin-1beta and downregulation of hydroxylprostaglandin dehydrogenase. Thus, PTGES is a novel HIF-1alpha target gene, involved in prostaglandin E biosynthesis in the esophageal tumor hypoxic microenvironment, and this has implications in diverse tumors types, especially of squamous origin.