COX-2 mRNA expression in esophageal squamous cell carcinoma (ESCC) and effect by NSAID

Arbidol inhibits human esophageal squamous cell carcinoma growth in vitro and in vivo through suppressing ataxia telangiectasia and Rad3-related protein kinase

Human esophageal cancer has a global impact on human health due to its high incidence and mortality. Therefore, there is an urgent need to develop new drugs to treat or prevent the prominent pathological subtype of esophageal cancer, esophageal squamous cell carcinoma (ESCC). Based upon the screening of drugs approved by the Food and Drug Administration, we discovered that Arbidol could effectively inhibit the proliferation of human ESCC in vitro. Next, we conducted a series of cell-based assays and found that Arbidol treatment inhibited the proliferation and colony formation ability of ESCC cells and promoted G1-phase cell cycle arrest. Phosphoproteomics experiments, in vitro kinase assays and pull-down assays were subsequently performed in order to identify the underlying growth inhibitory mechanism. We verified that Arbidol is a potential ataxia telangiectasia and Rad3-related (ATR) inhibitor via binding to ATR kinase to reduce the phosphorylation and activation of minichromosome maintenance protein 2 at Ser108. Finally, we demonstrated Arbidol had the inhibitory effect of ESCC in vivo by a patient-derived xenograft model. All together, Arbidol inhibits the proliferation of ESCC in vitro and in vivo through the DNA replication pathway and is associated with the cell cycle.

Parecoxib inhibits esophageal squamous cell carcinoma progression via the PDK1-AKT pathway

BACKGROUND

Parecoxib plays an important role in inhibition of human cancer. However, the effect of parecoxib on esophageal squamous cell carcinoma (ESCC) is still not well known. The purpose of this study was to investigate the effect of parecoxib on ESCC and its underlying mechanism.

METHODS

RNA-sequence analysis was performed to identify functional alterations and mechanisms. Cell cycle, proliferation, invasion, and migration were assessed using flow cytometry, CCK-8 assay, colony formation, transwell, and wound healing assays. Extracellular matrix (ECM) degradation was detected by substrate gel zymography and 3D cell culture assay. Western blotting was used to detect parecoxib-dependent mechanisms involving cell cycle, proliferation, invasion, and migration. Tumor formation in vivo was detected by mouse assay.

RESULTS

Functional experiments indicated that parecoxib induced ESCC cell cycle arrest in G2 phase, and inhibited cell proliferation, invasion, and migration in vitro. Western blotting revealed that parecoxib downregulated the phosphorylation levels of AKT and PDK1, as well as the expression of the mutant p53, cyclin B1, and CDK1, while upregulating p21waf1. Parecoxib inhibited matrix metalloproteinase-2 (MMP2) secretion and invadopodia formation, which were related to ECM degradation. Furthermore, we found that parecoxib suppressed ESCC growth in heterotopic tumor models.

CONCLUSION

Parecoxib inhibits ESCC progression, including cell cycle, proliferation, invasion, and migration, via the PDK1-AKT signaling pathway.

Over-Expression of Cyclooxygenase-2 in Colorectal Cancer Patients

Background:

Colorectal carcinoma (CRC) is the most common neoplasm of the gastrointestinal tract. COX-2 plays an important role in CRC development and is a key target for the regression of colorectal tumorigenesis by non-steroidal anti-inflammatory drugs. The present study was conducted to examine the relationship of the levels of COX-2 in CRC patients with the clinico-pathological parameters and also to assess its usefulness as a potential biomarker for diagnosis of CRC.

Methods:

Prior to surgery, 30 CRC patients were enrolled and the samples from colon tumors and surrounding tissues were taken after they underwent surgical intervention at PGIMER, Chandigarh. mRNA expression levels of COX-2 were examined in 30 CRC and adjacent normal colonic mucosa by quantitative polymerase chain reaction (qPCR). The expression of COX-2 was assessed by immunohistochemical method using rabbit polyclonal antibodies against human COX-2 protein.

Results:

The quantitative relative expression of COX-2 mRNA was observed to be significantly higher (p<0.05) in colorectal cancer tissues as compared to adjacent normal colon tissues. Also, female CRC patients showed significantly higher (p<0.009) expression of COX-2 mRNA vis-a-vis male colorectal cancer patients. This is the first study which has reported a direct relationship between COX-2 mRNA expressions in male colorectal cancer patients versus females. Further, immunohistochemistry of COX-2 confirmed the quantitative real time-PCR findings.

Conclusion:

Our study shows that COX-2 over expression in colorectal carcinoma patients is closely associated with clinico-pathological parameters and is more pronounced in males versus females. Further, COX-2 mRNA expression can serve as a potential biomarker for the diagnosis of CRC.

miR-196a regulates the proliferation, invasion and migration of esophageal squamous carcinoma cells by targeting ANXA1

MicroRNA (miR)-196a is upregulated in various types of malignancy, including esophageal squamous cell carcinoma (ESCC); however, its role in ESCC is currently unclear. The present study aimed to investigate the biological role and molecular mechanism of miR-196a in ESCC. The expression levels of miR-196a in 25 tumor tissues and adjacent non-tumor tissues from patients with ESCC were measured by reverse transcription-quantitative polymerase chain reaction. In addition, miR-196a expression levels were assessed in the human normal esophageal epithelial cell line Het-1A and the ESCC cell line EC109. The effects of miR-196a on the proliferation, apoptosis, invasion and migration of EC109 cells were determined by MTT, flow cytometry and Transwell assays, respectively. A luciferase reporter assay and western blotting were performed to confirm the target gene of miR-196a, and to explore the molecular mechanism underlying the effects of miR-196a on regulation of ESCC cell phenotypes. The results demonstrated that miR-196a was markedly upregulated in ESCC tissues and EC109 cells. In addition, miR-196a downregulation suppressed EC109 cell proliferation, invasion and migration, but did not affect apoptosis. Annexin A1 (ANXA1) was demonstrated to be a direct target gene of miR-196a. ANXA1 protein knockdown reversed the effects of miR-196a inhibition on EC109 cell proliferation, invasion and migration. Furthermore, alongside the downregulation of miR-196a and the increase in ANXA1 expression, cyclooxygenase 2 (COX2), matrix metalloproteinase (MMP)-2 and Snail were downregulated, and E-cadherin was upregulated in EC109 cells. The results of the present study suggested that miR-196a may act as an oncogene in ESCC, and that miR-196a may regulate the proliferation, invasion and migration of ESCC cells by targeting ANXA1. Subsequently, ANXA1 may further modulate the expression levels of COX2, MMP-2, Snail and E-cadherin. In conclusion, the miR-196a/ANXA1 axis may represent a potential therapeutic target in ESCC.

Simvastatin, but not pravastatin, inhibits the proliferation of esophageal adenocarcinoma and squamous cell carcinoma cells: a cell-molecular study

Background and objective

Long-term statin therapy has been shown to protect against several cancers, including esophageal cancer (EC). While the mechanisms underlying this effect are not clear. We investigated the effect of hydrophobic simvastatin and hydrophilic pravastatin on the proliferation of EC cells and sought to explore the underlying mechanisms.

Methods

Esophageal adenocarcinoma OE-19 cells and esophageal squamous cell carcinoma Eca-109 cells were treated with different concentrations of simvastatin or pravastatin for 24 h and 48 h. Cell proliferation was assessed by Cell Counting Kit-8 assay. Malondialdehyde (MDA) levels were measured by thiobarbituric acid (TBA) assay. mRNA and protein expression of COX-2 were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively; The expression of prostaglandin E₂ (PGE₂) was measured by ELISA.

Results

Simvastatin, but not pravastatin, significantly inhibited the proliferation of OE-19 and Eca-109 cells in a dose- and time-dependent manner, accompanying with the increasing of the MDA level. Moreover, simvastatin suppressed the expression of COX-2 and PGE₂ in both OE-19 and Eca-109 cells in a dose-dependent manner.

Conclusions

Lipophilic simvastatin, but not hydrophilic pravastatin, had significant inhibitory effects on the proliferation of Eca-109 and OE-19 cells. The reduction of COX-2 and PGE₂ by simvastatin suggested that the inhibitory effect of simvastatin on the proliferation of EC cells may be independent of its lipid-lowering effect. Simvastatin may be a promising agent for the prevention and treatment of EC.

Association between cyclooxygenase-2 gene polymorphisms and head and neck squamous cell carcinoma risk

Cyclooxygenase-2 (COX-2) is an inducible enzyme that catalyzes prostaglandins through inflammatory response, which may be involved in autoimmune diseases and cancer pathogenesis. Two potentially functional genetic single-nucleotide polymorphisms (COX-2 -1195G>A and 8473T>C) were supposed to contribute to head and neck squamous cell carcinoma (HNSCC) susceptibility. The aim of this study was to determine the association of these polymorphisms with HNSCC susceptibility in a Chinese Han population. In this study, 2 SNPs were genotyped by TaqMan methods in a patient-control study including 260 patients with HNSCC and 1047 cancer-free controls in a Chinese Han population. We found significant difference in the frequency of alcohol consumption between the patients with HNSCC and controls (P < 0.001), but the genotype frequencies of the 2 polymorphisms were not significantly different between the patients and controls. Further stratified analysis indicated that none of the genotypes were associated with increased risk for HNSCC. This research indicated that the COX-2 -1195G>A and 8473T>C polymorphisms may not be involved in the development of HNSCC in the Chinese Han population. However, further perspective studies are warranted to test these findings and further investigate the potential interactions involving the COX-2 polymorphism and HNSCC.

Cyclooxygenase-2 gene polymorphisms and the risk of colorectal cancer: A population-based study

The aim of the present study was to determine the association between polymorphisms in the cyclooxygenase-2 (COX-2) gene promoter region, rs20417 G/C and rs2745557 G/A, and the susceptibility to colorectal cancer (CRC) in a Han Chinese population in Shaanxi, China. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to detect the polymorphisms of COX-2, rs20417 G/C and rs2745557 G/A, in 300 patients with CRC and 300 healthy individuals in the present case-control study. The results revealed that for the COX-2 rs20417 G/C polymorphism, the GC+CC allele frequency was 80% in CRC patients and 71% in healthy controls [odds ratio (OR)=1.63; 95% confidence interval (CI), 1.12-2.38; P=0.01]. For the COX-2 rs2745557 G/A polymorphism, the GA+AA allele frequency was 84% in CRC patients and 73% in healthy controls (OR=1.94; 95% CI, 1.30-2.90; P<0.01). In addition, among individuals with a smoking history, drinking history or family history of CRC, those who were COX-2 rs20417 (GC+CC) or COX-2 rs2745557 (GA+AA) carriers had a significantly increased risk of developing CRC compared with that of GG genotype carriers (P<0.05). Furthermore, the allelic frequencies of COX-2 rs20417 G/C and rs2745557 G/A in patients with lymph node metastasis in stage III/IV of CRC were significantly different from those of COX-2 rs20417 G/C and rs2745557 G/A in patients without lymph node metastasis in stage I/II (P<0.05). In conclusion, the results of the present study revealed that COX-2 rs20417 C allele carriers and rs2745557 A allele carriers have a significantly increased risk of CRC compared with GG genotype carriers; in addition, the frequencies of these alleles were demonstrated to be associated with lymph node metastasis and CRC progression.

Prevention of head and neck squamous cell carcinoma: removing the "chemo" from "chemoprevention"

The concept of chemoprevention whereby the use of a systemic agent is intended to halt the carcinogenesis process has been an attractive topic in head and neck squamous cell carcinoma (HNSCC). Yet, despite the significant efforts over the past decades and the substantial gain in knowledge of the biology of pre-malignant lesions of the head and neck, no tangible indications for chemoprevention have emerged for this disease. The negative results observed in the earlier larger studies using retinoids did not encourage further trials with these agents. Attention has been more recently focused on epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) as well as cyclo-oxygenase 2 (COX-2) inhibitors with early studies showing encouraging responses but rather poor tolerance to therapy. Natural compounds have gained more interest recently given preclinical evidence of activity as well as a low side effect profile. We herein offer a comprehensive overview of the field of chemoprevention in HNSCC with an in depth analysis of the challenges we face and discuss a road map for future directions.

Effect of nimesulide on the growth of human laryngeal squamous cell carcinoma

PURPOSE

To investigate the effect of nimesulide on the growth of human laryngeal squamous cell carcinoma.

MATERIALS AND METHODS

The effect of NIM on Hep-2 cell proliferation was measured by the MTT assay. Flow cytometry was used to evaluate the cell cycle and apoptosis in Hep-2 cells. A Western blot analysis was used to detect changes in the protein expression levels of COX-2, Survivin and proliferating cell nuclear antigen (PCNA) in Hep-2 cells. A Hep-2 tumor xenograft model was established in nude mice to observe tumor growth. The changes in the xenograft tumors were observed after hematoxylin/eosin staining. The expression levels of COX-2, Survivin and PCNA proteins and mRNA were measured by immunohistochemical analysis and RT-PCR, respectively.

RESULTS

NIM had time- and dose-dependent inhibitory effect on the proliferation of Hep-2 cells. NIM could prevent the progression of the cell cycle. After NIM treatment, COX-2, Survivin and PCNA protein levels were reduced in the Hep-2 cells. The volume and weight of the xenograft tumors in the NIM treatment group were significantly reduced. The NIM treatment group also exhibited significantly reduced expression levels of COX-2, Survivin and PCNA at both the protein and mRNA levels.

CONCLUSIONS

Our results suggested that NIM has significant inhibitory effects on the growth of Hep-2 cells and xenograft tumors in nude mice. Selective COX-2 inhibitors could potentially become part of a comprehensive treatment for laryngeal squamous cell carcinoma. Additional research and development will provide new and broader prospects for the prevention and treatment of laryngeal squamous cell carcinoma.

Over-expression of COX-2 mRNA in colorectal cancer

BACKGROUND

Cyclooxygenase-2 (COX-2, PTGS2) is an enzyme involved in the synthesis of prostaglandins and thromboxanes, which are regulators of biologic processes such as inflammation, cell proliferation and angiogenesis. COX-2 over-expression was reported in many (pre) malignant tissues, but data strongly vary and seem to depend on the methodology used.

METHODS

Normal colorectal mucosa and paired cancerous tissue from 60 patients with colorectal cancer was investigated for the levels of COX-2 mRNA by real-time quantitative Polymerase Chain Reaction (qPCR). COX-2 levels were expressed relative to either: tissue weight or levels of the housekeeping genes beta-2 microglobulin (B2M) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH).

RESULTS

COX-2 mRNA levels, normalized with respect to tissue weight or mRNA levels of the housekeeping genes B2M or GAPDH, were over-expressed in 80%, 70% and 40% of the colorectal tumor tissues, as compared to the paired adjacent normal colorectal mucosa samples, respectively. Highest mRNA COX-2 ratios tumor/normal were measured when expressed per mg tissue (mean ratio 21.6). When normalized with respect to the housekeeping genes B2M or GAPDH, mean tumor/normal ratios were 16.1 and 7.5, respectively.

CONCLUSION

Expression of COX-2 mRNA levels per mg tissue is most simple in comparison to normalization with respect to the housekeeping genes B2M or GAPDH. Levels of COX-2 mRNA are found over-expressed in almost 80% of the colorectal tumors, compared to paired adjacent normal colorectal mucosa, suggesting a role of COX-2 as a potential biomarker for cancer risk, whereas inhibitors of COX-2 could be of value in chemoprevention of colon cancer.

A genetic variant in 3'-untranslated region of cyclooxygenases-2 gene is associated with risk of gastric cancer in a Chinese population

Cyclooxygenase-2 (COX-2) involves in multiple processes in carcinogenesis, including inflammation, apoptosis inhibition, immune response suppression, tumor cell invasion, and angiogenesis. COX-2 is overexpressed in various cancers, including gastric cancer. COX-2 is encoded by prostaglandin endoperoxide synthase 2 (PTGS2) gene. We hypothesized that potentially functional polymorphisms in PTGS2 may contribute to gastric cancer risk. To assess this hypothesis, we conducted a case-control study with 1681 gastric cancer cases and 1916 control subjects in a Chinese population to evaluate the association between a polymorphism in 3'-untranslated region of PTGS2, rs5275, and the risk of gastric cancer. Logistic regression analysis revealed that variant allele (C) of rs5275 was significantly associated with an increased risk of gastric cancer (per allele odds ratio [OR] = 1.14, 95% confidence interval [CI] = 1.01-1.29, p = 0.030). This association was more prominent in females (per allele OR = 1.42, 95% CI = 1.11-1.81, p = 0.005) and nonsmokers (per allele OR = 1.35, 95% CI = 1.14-1.59, p = 0.001). Interestingly, we detected a negative interaction between rs5275 and smoking on the gastric cancer risk (p = 0.007). Our findings indicate that PTGS2 rs5275T/C may be a candidate genetic marker for gastric cancer susceptibility.

Dual inhibition of 5-LOX and COX-2 suppresses esophageal squamous cell carcinoma

COX-2 and 5-LOX are up-regulated in ESCC. This study aims to determine the efficacy of COX-2 inhibitor, 5-LOX inhibitor and their combination on ESCC. Nimesulide can suppress cell growth and promote apoptosis, accompanied with a decrease of PGE(2) production. AA861 has the similar effect with a down-regulation of LTB(4). In animal experiment, the tumor volumes in drug-treated groups were significantly smaller with the lowest rates of Ki-67 positive cells. In conclusion, either COX-2 inhibitor or 5-LOX inhibitor can suppress ESCC. Dual inhibition of COX-2 and 5-LOX pathway may present a superior anticancer efficacy to either inhibition of COX-2 or 5-LOX alone.

Cyclooxygenase-2 polymorphisms and susceptibility to esophageal cancer: a meta-analysis

Esophageal cancer (EC) is one of the most common cancers worldwide with 5-year survival rate less than 10%. However, there is a lack of specific genetic markers that could help better understanding the mechanisms of esophageal carcinogenesis, improving the detection rate of EC, and distinguishing histological types. Cyclooxygenase-2 (COX-2) as an inducible enzyme in cancer development and progression is involved in esophageal carcinogenesis. A large number of studies have demonstrated a strong association between COX-2 polymorphisms and EC risk. However, the overall results are still controversial. This controversy may be partly due to the mix-up of esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAC). The aim of this study was to investigate the association between COX-2 polymorphisms and susceptibility to ESCC or EAC by conducting a meta-analysis. Seven studies were retrieved reporting a total of 1450 ESCC patients, 523 EAC patients, and 2663 cancer-free control subjects. Five COX-2 polymorphisms were addressed, including -765G>C (rs20417), -1195G>A (rs689465), -1290A>G (rs689466), -8473T>C (rs5275) and -1759G>A (rs3218625). Meta-analysis results showed that the -765C allele is significantly associated with the susceptibility to both ESCC and EAC especially in Asian populations. In addition, there was a significant association between the -8473C allele and the susceptibility to EAC in Caucasian populations. In conclusion, our meta-analysis suggests that the -765C allele of the COX-2 gene might be a potential risk factor for both ESCC and EAC especially in Asian populations, while the -8473C allele might be a risk factor for EAC in Caucasian populations.

Alterations of folliculogenesis in women with polycystic ovary syndrome

The objective of the present study was to examine some factors involved in follicular development of women with polycystic ovary syndrome (PCOS). Women with PCOS showed increased levels of serum luteinizing hormone (LH) but decreased follicular production of progesterone and estradiol by pre-ovulatory follicles. The mRNA expression corresponding to steroidogenic acute regulatory protein (StAR), and 20alpha-hydroxysteroid dehydrogenase (20α-HSD) was increased, while that corresponding to cytochrome P450 aromatase (P450arom) was decreased in PCOS follicles as compared to controls. No changes in the mRNA expression for 3beta-hydroxysteroid dehydrogenase 2 (3β-HSD2), cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 alpha hydroxylase/lyase (P450c17), cyclooxygenase 2 (COX2), and transcription factors (GATA-4 and GATA-6) were found. We conclude that despite the hyper-luteinized environment of PCOS follicles, these follicles produce lower levels of progesterone and estradiol, and that this is characterized by increased degradation of progesterone and decreased estradiol synthesis. Our data demonstrate that the synthesis of prostaglandin F2α (PGF2α) may be affected in PCOS-follicles and that the transcription factors GATA-4 and GATA-6 are present in PCOS-follicles but they are not involved in the abnormal transcription observed in the steroidogenic enzymes.

Potentially functional COX-2-1195G>A polymorphism increases the risk of digestive system cancers: a meta-analysis

BACKGROUND AND AIM

Three potentially functional polymorphisms: -765G>C, -1195G>A, and 8473T>C in the cyclooxygenase-2 (COX-2) gene were identified and proposed to be associated with cancer susceptibility. The aim of this meta-analysis was to evaluate the association between these three polymorphisms and the risk of cancer in diverse populations.

METHODS

All case-control studies published up to November 2009 on the association between the three polymorphisms of COX-2 and cancer risk were identified by searching PubMed. The cancer risk associated with the three polymorphisms of the COX-2 gene was estimated for each study by OR together with its 95% confidence interval (CI), respectively.

RESULTS

A total of 47 case-control studies were included, and variant genotypes GA/AA of -1195G>A were associated with a significantly increased cancer risk (GA/AA vs GG: odds ratio [OR], 1.29; 95% CI, 1.18-1.41; P(heterogeneity) = 0.113), and this significant association was mainly observed within cancers of the digestive system (e.g. colorectal, gastric, esophageal, oral, biliary tract, gallbladder, and pancreatic) without between-study heterogeneity (GA/AA vs GG: OR, 1.36; 95% CI; 1.23-1.51; P(heterogeneity) = 0.149). Furthermore, a stratification analysis showed that the risk of COX-2-1195G>A associated with cancers in the digestive system was more evident among Asians than Caucasians. However, for COX-2-765G>C and 8473T>C, no convincing association between the two polymorphisms and risk of cancer or cancer type was observed.

CONCLUSIONS

The effect of three potentially functional polymorphisms (-765G>C, -1195G>A, and 8473T>C) in the COX-2 gene on cancer risk provided evidence that the COX-2-1195G>A polymorphism was significantly associated with increased risk of digestive system cancers, especially among Asian populations.

A review of in vitro and in vivo models of oesophageal and gastric cancer

IMPORTANCE OF THE FIELD

Oesophageal and gastric cancers are leading causes of cancer-related mortality. In the era of targeted therapy and individualized treatment strategies, novel treatments for upper-gastrointestinal cancers are only just emerging compared to significant advances in other solid tumour types such as colorectal, breast and lung cancers. Clinical trials are investigating the value of established targeted agents for the treatment of oesophageal and gastric malignancies; however none are used in routine clinical practice.

AREAS COVERED IN THIS REVIEW

In this review we have looked at current in vitro and in vivo models of oesophageal and gastric cancers which may improve our understanding of the biology of these tumours and lead to the development of new preventative, diagnostic and therapeutic approaches.

WHAT THE READER WILL GAIN

We discuss the limitations of our current models and the challenges associated with research into these cancers.

TAKE HOME MESSAGE

The lack of appropriate models for drug development in oesophageal and gastric cancers has hindered the progress of targeted therapy in this field.

Cyclooxygenase-2 polymorphisms and the risk of esophageal adeno- or squamous cell carcinoma

AIM: To determine whether -1195 A→G and/or -765 G→C polymorphisms in Cyclooxygenase-2 (COX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population.

METHODS: Two study groups were recruited, 252 patients with esophageal carcinoma and 240 healthy controls, matched for race, age, gender and recruiting area. DNA was isolated from whole blood and used for genotyping. PCR products were digested with restriction enzymes and products were analyzed by agarose gel electrophoresis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated.

RESULTS: The distribution of the -1195 A→G polymorphism was significantly different in esophageal cancer patients compared to controls. The -1195 GG genotype resulted in a higher risk of developing esophageal adenocarcinoma (OR = 3.85, 95% CI: 1.45-10.3) compared with the -1195 AA genotype as a reference. The -765 G→C genotype distribution was not different between the two groups. The GG/GG haplotype was present more often in esophageal adenocarcinoma patients than in controls (OR = 3.45, 95% CI: 1.24-9.58; with AG/AG as a reference). The same trends were observed in patients with squamous cell carcinomas, however, the results did not reach statistical significance.

CONCLUSION: Presence of the COX-2 -1195 GG genotype and of the GG/GG haplotype may result in a higher risk of developing esophageal carcinoma.

Effects of the inhibition of cyclooxygenase-2 on human esophageal cancer cells: inhibition of cell proliferation and induction of apoptosis

Cyclooxygenase-2 (COX-2) has been shown to be upregulated in a variety of tumors so that COX-2 may be a potential target in the treatment of cancer. In order to further explore the mechanism, we used RNA interference to study effects of the inhibition of COX-2 on esophageal squamous cell carcinoma (ESCC) lines. Western blot analysis demonstrated that COX-2 expression was significantly reduced in ESCC cells treated with the COX-2-specific siRNA. Furthermore, the COX-2 siRNA treatment inhibited cell proliferation and induced apoptosis in ESCC cells. In addition, the combination treatment of COX-2 siRNA and acidum acetil salicylicum (aspirin) has a synergistic effect. Therefore, this combination has potential as an anticancer therapy for the treatment of ESCC.