Correlation of p53, MDM2 and p14(ARF) protein expression in human esophageal squamous cell carcinoma

Functional identification and prediction of lncRNAs in esophageal cancer

Esophageal cancer is a highly lethal malignancy with poor prognosis, and the identification of molecular biomarkers is crucial for improving diagnosis and treatment. Long non-coding RNAs (lncRNAs) have been shown to play important roles in the development and progression of esophageal cancer. However, due to the time cost of biological experiments, only a small number of lncRNAs related to esophageal cancer have been discovered. Currently, computational methods have emerged as powerful tools for identifying and characterizing lncRNAs, as well as predicting their potential functions. Therefore, this article proposes a transformer-based method for identifying esophageal cancer-related lncRNAs. Experimental results show that the AUC and AUPR of this method are superior to other comparison methods, with an AUC of 0.87 and an AUPR of 0.83, and the identified lncRNA targets are closely associated with esophageal cancer. We focus on the role of esophageal cancer-related lncRNAs in the immune microenvironment, and fully explore the functions of the target genes regulated by lncRNAs. Enrichment analysis shows that the predicted target genes are related to multiple pathways involved in the occurrence, development, and prognosis of esophageal cancer. This not only demonstrates the effectiveness of the method but also indicates the accuracy of the prediction results.

High Expression of MDM2 and the p53 Protein is Predictive Biomarkers for Poor Prognosis of Oesophageal Squamous Cell Carcinoma

Background and Objective

In the present study, we detected the expression of MDM2 and p53 in oesophageal squamous cell carcinoma (OSCC) specimens, studied their relationship with the survival of OSCC patients, and explored the potential of MDM2 and p53 to serve as predictive OSCC tumour markers.

Patients and Methods

Through immunohistochemistry and fluorescence in situ hybridization (FISH), we detected the expression of MDM2 and the p53 protein in 157 OSCC specimens that met the inclusion and exclusion criteria. After scoring the results, Pearson’s chi-square test and Cox regression were used for analysis.

Results

The results showed that the rates of high MDM2 and p53 expression in OSCC tissues were 60.5% and 51.0%, respectively. The expression levels of MDM2 and p53 in OSCC were significantly positively correlated (p<0.001, r=0.414). In addition, the pathological metastasis (M) status and MDM2 protein expression in OSCC were significantly correlated (p=0.027), and high expression of the p53 protein was positively correlated with OSCC transfer (p=0.005), pathological node status (p=0.008), and clinical stage (p=0.003). Kaplan-Meier survival analysis showed that the high expression of MDM2 and p53 was significantly related to the poor prognosis of OSCC. Moreover, subgroup analysis of the TNM staging of OSCC patients showed that the high expression of MDM2 and p53 was significantly correlated with poor OS and DFS of OSCC patients in either stage I–II or III–IV patients. Both univariate and Cox multivariate analyses showed that p53 and MDM2 can be used as independent factors for the prognosis of OSCC patients. Finally, our FISH detection results for MDM2 showed that the high expression of MDM2 was significantly correlated with the amplification of MDM2 (p=0.015).

Conclusion

This study shows that MDM2 and p53 can be used as independent predictors of the prognosis of patients with oesophageal squamous cell carcinoma.

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.

p16 gene silencing along with p53 single-nucleotide polymorphism and risk of esophageal cancer in Northeast India

The high incidence of esophageal cancer in Northeast India and the unique ethnic background and dietary habits provide a great opportunity to study the molecular genetics behind esophageal squamous cell carcinoma in this part of the region. We hypothesized that in addition to currently known environmental risk factors for esophageal cancer, genetic and epigenetic factors are also involved in esophageal carcinogenesis in Northeast India. Therefore, in this study, we explored the possible association between the two important G1 cell cycle regulatory genes p16 and p53 and environmental risk factors and risk of esophageal carcinogenesis. A total of 100 newly diagnosed esophageal cancer cases along with equal number of age-, sex-, and ethnicity-matched controls were included in this study. Methylation-specific polymerase chain reaction was used to determine the p16 promoter methylation status. Single-nucleotide polymorphism at codon 72 of p53 gene was assessed by the polymerase chain reaction-restriction fragment length polymorphism method. Aberrant methylation of p16 gene was seen in 81% of esophageal cancer cases. Hypermethylation of p16 gene was not found in healthy controls. p53 Pro/Pro genotype was found to be a risk genotype in Northeast India compared with Arg/Pro and Arg/Arg. p53 variant/polymorphism was significantly associated with esophageal cancer risk in the study population under all three genetic models, namely, dominant model (Arg/Pro + Pro/Pro vs Arg/Arg odds ratio = 2.25, confidence interval = 1.19-4.26; p = 0.012), recessive model (Arg/Arg + Arg/Pro vs Pro/Pro odds ratio = 2.35, confidence interval = 1.24-4.44; p = 0.008), and homozygous model (Pro/Pro vs Arg/Arg odds ratio = 3.33, confidence interval = 1.54-7.20; p = 0.002). However, p53 variant/polymorphism was not statistically associated with esophageal cancer risk under the heterozygous model (Pro/Pro vs Arg/Pro). In the case-only analysis based on p16 methylation, the p53 variant/polymorphism (Pro/Pro or Arg/Pro) showed significant association for esophageal cancer risk (odds ratio = 3.33, confidence interval = 1.54-7.20; p = 0.002). Gene-gene and gene-environment interaction using the case-only approach revealed a strong association between p16 methylation, p53 single-nucleotide polymorphism, and environmental factors and esophageal cancer risk. Cases with p16 methylation and p53 variant/polymorphism (Pro/Pro or Arg/Pro) along with both betel quid and tobacco chewing habit (odds ratio = 8.29, confidence interval = 1.14-60.23; p = 0.037) conferred eightfold increased risk toward esophageal cancer development. This study reveals a synergistic interaction between epigenetic, genetic, and environmental factors and risk of esophageal cancer in this high-incidence region of Northeast India. The inactivation of either p16 or p53 in a majority of esophageal cancer cases in this study suggests the possible crosstalk between the important cell cycle genes.

A high number of stromal tumor-infiltrating lymphocytes is a favorable independent prognostic factor in M0 (stages I-III) esophageal squamous cell carcinoma

Esophageal cancer is a highly invasive tumor with a poor prognosis. Lymphocytes play an important role in systemic immune responses, but their role in cancers varies depending on the specific tumor microenvironment. The aim of this study was to provide evidence for tumor-infiltrating lymphocytes (TILs) as a prognostic biomarker in esophageal squamous cell carcinoma. TIL analysis was retrospectively performed on full-face hematoxylin and eosin-stained sections from 127 patients. A majority (92.6%) of tumors had at least 10% stromal TILs (sTILs) (range, 10%-90%), and 84.3% of cancers had at least 10% intraepithelial TILs (iTILs) (range, 10%-40%). Multivariate analysis showed progressively better overall survival (P < 0.001, hazard ratio = 0.968, 95% confidence interval 0.955-0.981) and disease-free survival (P = 0.005, hazard ratio = 0.982, 95% confidence interval 0.970-0.995) in patients with higher sTILs. Marginal increases in overall survival and disease-free survival were found in the higher iTILs cohort versus the lower iTILs cohort, but the difference was not significant. In conclusion, in addition to tumor stage increasing stromal lymphocytic infiltration is an independent prognostic factor for esophageal squamous cell carcinoma treated by radical resection.

Genetic variants in CHEK1 gene are associated with the prognosis of thoracic esophageal squamous cell carcinoma patients treated with radical resection

CHEK1 gene is known to play an important role in tumor progression by cell cycle control. However, the association between CHEK1 and the prognosis of esophageal squamous cell carcinoma (ESCC) is unclear. In this study, we explored the association between genetic variants in CHEK1 gene and prognosis of ESCC patients treated with radical resection. A total of 131 thoracic ESCC patients who underwent radical resection were included in this retrospective study and genotyped using the MassArray method. According to the univariate Cox hazard analysis, the GT/TT genotype of CHEK1 rs555752 was shown to be strongly related to a decreased overall survival (OS) (HR=2.560, 95% CI: 1.415-4.631, P=0.002) and disease-free survival (DFS) (HR=2.160, 95% CI: 1.258-3.710, P=0.005). Furthermore, according to the multivariate Cox hazard analysis and multiple testing, patients with the GT/TT genotype of CHEK1 rs555752 had a notably decreased OS (HR=2.735, 95% CI: 1.468-5.096, P=0.002, Pc=0.006) and DFS (HR=2.282, 95% CI: 1.292-4.023, P=0.004, Pc=0.012). In conclusion, genetic variants of the CHEK1 gene are significantly related to OS and DFS of ESCC patients, and may therefore be predictors of the prognosis of thoracic ESCC after surgery.

Translocation of BBAP from the cytoplasm to the nucleus reduces the metastatic ability of vemurafenib-resistant SKMEL28 cells

To the best of our knowledge, the present study is the first to demonstrate that treatment of vemurafenib-resistant SKMEL28 (SKMEL28-R) cells with paclitaxel leads to a shift in localization of the E3-ligase BBAP from the cytoplasm to the nucleus, consequently decreasing the metastatic ability of this cell line. The present study revealed that the movement of BBAP from the cytoplasm to nucleus initiated a change in cell morphology. In addition, the translocation of BBAP led to a decrease of metastatic characteristics in SKMEL28‑R cells, including migration and invasion via downregulation of the phosphorylated form of focal adhesion kinase and N‑cadherin, as well as an upregulation of p21 and E-cadherin. The results of the present study suggested that BBAP may not only be a novel biomarker for melanoma, but also a novel therapeutic target for treatment of metastatic melanoma.

BRCA1 and MDM2 as independent blood-based biomarkers of head and neck cancer

We investigated the role of BRCA1, MDM2, and p53 in the pathogenesis of head and neck cancer (HNC) and evaluated their potential utility as blood-based predictive biomarkers of HNC. Immunostaining of tissue biopsies and whole blood lymphocytes (WBL) of 36 HNC patients were evaluated by immunohistochemistry (IHC) and immunocytochemistry (ICC), respectively. The staining intensities of BRCA1 and MDM2 in matched tissue and blood samples were significantly associated with cancer stage. Furthermore, the cellular levels of BRCA1, MDM2, and p53 were evaluated in peripheral blood lymphocytes (PBL) of 134 HNC patients and 126 controls by slot blotting. Expression levels of all three proteins in PBL of HNC patients varied significantly with respect to those of controls (p < 0.0001) with BRCA1 downregulated to 75 % of control and MDM2 and p53 upregulated to 1.7- and 1.4-fold the control level, respectively. Moreover, positive correlation was observed between expression levels of BRCA1, MDM2, and p53 in matched tissue biopsies-WBL (r s = 0.840, 0.754, and 0.806, respectively), tissue biopsies-PBL (r s = 0.745, 0.736, and 0.776, respectively), and PBL-WBL (r s = 0.709, 0.758, and 0.740, respectively), validating the hypothesis that these proteins may serve as blood-based biomarkers of HNC. Bias-corrected and accelerated (BCa) bootstrap cross-validation estimation of receiver operating characteristics (ROC) analysis established BRCA1 (AUC = 0.726, sensitivity = 89 %, NPV = 82 %) and MDM2 (AUC = 0.827, sensitivity = 85 %, NPV = 81 %) as predictive biomarkers for HNC. In conclusion, this study suggests that BRCA1 and MDM2 play a crucial role in the pathogenesis of HNC and could be used independently as predictive biomarkers for HNC.

Association between positive murine double minute 2 expression and clinicopathological characteristics of esophageal squamous cell carcinoma: a meta-analysis

The correlations of murine double minute 2 (MDM2) T309G and esophageal cancer were elucidated because the association between MDM2 expression states and clinicopathological parameters of esophageal squamous cell carcinoma (ESCC) is controversial. We conducted a meta-analysis on studies screened from PubMed, Web of Science, Embase, the Cochrane Library, and the Chinese Biomedical Literature Databases that were published before October 2014. All studies describing the association between MDM2 and ESCC were traced. Meta-analysis was performed using the STATA software (Stata Corp., College Station, TX, USA). A total of 9 studies with 707 cases and 324 controls were included. MDM2 expression was higher in ESCC than in normal esophageal epithelium (odds ratio [OR] 10.38, 95% confidence interval [CI] 6.42-16.78, P < 0.001). High MDM2 expression was associated with early primary tumor stage (T1/T2 vs. T3/T4, OR 0.59, 95% CI 0.38-0.92, P = 0.018) and increased risk of regional lymph node metastasis (N0 vs. N1, OR 1.66, 95% CI 1.03-2.67, P = 0.039). However, no relationship was observed between MDM2 expression and the risk of distant metastasis (OR = 2.09, 95% CI 1.00-4.36, P = 0.050), and MDM2 was not significantly correlated with TP53 expression (OR 1.22, 95% CI 0.53-2.77, P = 0.643). Our analysis suggests that MDM2 acts as a potent marker of early primary tumor stage but higher risk of regional lymph node metastasis in ESCC. However, because of the limited number of studies included, the result should be further clarified by well-designed prospective studies.

Genetic Variants in the p14ARF/MDM2/TP53 Pathway Are Associated with the Prognosis of Esophageal Squamous Cell Carcinoma Patients Treated with Radical Resection

The p14ARF/MDM2/ TP53 pathway is known to play an important role in tumor progression by cell cycle control, although the association between this pathway and the prognosis of esophageal squamous cell carcinoma (ESCC) is unclear. In this study, we explored the association between genetic variants in the p14ARF/MDM2/TP53 pathway and prognosis in ESCC patients with radical resection. 124 ESCC patients with radical resection were included in this retrospective study and genotyped using the MassArray method. According to multivariate Cox hazard analysis and multiple testing, the TC/CC genotype of p14ARF rs3814960 was shown to be strongly related to a decreased overall survival (OS) (HR = 2.77, 95% CI: 1.33–5.75, P = 0.006, Pc = 0.030) and disease-free survival (DFS) (HR = 2.45, 95% CI: 1.30–4.61, P = 0.005, Pc = 0.025). Moreover, patients with the DEL/A +AA genotype of MDM2 rs34886328 had a notably increased OS (HR = 0.27, 95% CI: 0.13–0.56, P = 4.7×10⁻⁴, Pc = 0.003) and DFS (HR = 0.22, 95% CI: 0.11–0.43, P = 1.1×10⁻⁵, Pc = 6.6×10⁻⁵). We also found that these two SNPs had a cumulative effect on the prognosis of ESCC, with the OS (P < 0.001) and DFS (P < 0.001) being shortest for patients carrying both of these unfavorable genotypes. In conclusion, genetic variants of the p14ARF/MDM2/TP53 pathway are significantly related to OS and DFS, and may be predictors of the prognosis of ESCC after surgery. We speculate the individuals with the TC/CC genotype of p14ARF rs3814960 and/or the DEL/DEL genotype of MDMD2 rs34886328 should have more aggressive treatment and may greatly benefit from early prediction and prevention of an unfavorable prognosis by genotyping before the initiation of therapy. These findings should be further validated in a larger population.

Prognostic significance of p53 expression in patients with esophageal cancer: a meta-analysis

Background

The prognostic value of p53 protein expression in esophageal cancer has been evaluated, but the results remain inconclusive and no consensus has yet been achieved. This meta-analysis was conducted to quantitatively assess the prognostic significance of p53 expression in esophageal cancer.

Methods

Publications that assessed the clinical or prognostic significance of p53 expression in esophageal cancer and were published before July 1, 2015 were identified by searching the PubMed and EMBASE databases. A meta-analysis was performed to clarify the association between p53 expression and the clinical outcomes.

Results

A total of 36 publications met the criteria and included 4577 cases. Analysis of these data showed that p53 expression in esophageal cancer was significantly associated with poorer 5-year survival (RR = 1.30, 95 % CI: 1.11–1.51, P = 0.0008). Subgroup analyses according to histological type, continent of the patients, and cut-off value revealed the similar results. The results also indicated that p53 expression was highly associated with advanced TNM stages (I/II vs. III/IV, OR = 0.74, 95 % CI: 0.55–0.99, P = 0.04), lymph node metastasis (OR = 0.77, 95 % CI: 0.66–0.90, P = 0.001), and distant metastasis (OR = 0.46, 95 % CI: 0.26–0.80, P = 0.006). However, p53 expression in the included studies was not significantly associated with tumor size (≤ 5 cm vs. > 5 cm, OR = 1.13, 95 % CI: 0.92–1.40, P = 0.24), tumor location (upper + middle vs. lower, OR = 0.91, 95 % CI: 0.70–1.17, P = 0.45), grade of differentiation (well + moderate vs. poor, OR = 1.10, 95 % CI: 0.90–1.34, P = 0.35), and the depth of invasion (T1/T2 vs. T3/T4, OR = 0.86, 95 % CI: 0.71–1.03, P = 0.09).

Conclusions

This meta-analysis showed that p53 expression may be a useful biomarker for predicting poorer prognosis in patients with esophageal cancer.

Relationship between P53 status and prognosis and clinicopathologic characteristics in esophagus squamous cell carcinoma: A systematic review

AIM: To evaluate the prognostic role of p53 status and its relationship with clinicopathologic characteristics in esophagus squamous cell carcinoma (ESCC).

METHODS: A systematic search of PubMed, SCI-Ex-panded, EMBASE, the Cochrane library, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Database (CBM), and science and technology periodical database (VIP) was performed. Related references were also searched for additional clinical studies. Two reviewers independently performed screening of identified studies and data extracting according to inclusion and exclusion criteria. The quality assessment was conducted on the basis of the Newcastle-Ottawa Quality Assessment Scale (NOS). The evaluation of the publication bias of the included studies and data synthesis were performed with RevMan 5.3. A fixed-effect or random effects model was adopted according to heterogeneity.

RESULTS: A total of 85 studies involing 8825 cases met the inclusion criteria. The experimental group (4608 cases) was positive for either p53 gene mutation or protein expression, and the control group (4217 cases) was negative for either p53 gene mutation or protein expression. The pooled hazard ratio (HR) for OS was 1.35 (95%CI: 1.23-1.47, P < 0.00001; heterogeneity: P = 0.39, I² = 5%). The pooled risk ratio (RR) for the 5-year and 3-year survival rates was 0.73 (95%CI: 0.62-0.87, P = 0.0003; heterogeneity: P = 0.001, I² = 50%) and 0.87 (95%CI: 0.74-1.02, P = 0.09; heterogeneity: P = 0.28, I² = 18%). p53 gene mutation or protein expression was significantly associated with poorer T stage (RR = 1.09, P = 0.004), N stage (RR = 1.24, P < 0.00001), M stage (RR = 1.65, P < 0.00001), TNM stage (RR = 1.25, P < 0.00001) and differentiation degree (RR = 1.06, P = 0.03). However, there were no association between P53 status and vascular invasion, tumor location, size, age or gender in ESCC (P>0.05).

CONCLUSION: p53 gene mutation or protein expression abnormality is a marker of poor prognosis in patients with ESCC. Meantime, patients with P53 abnormalities are associated with higher depth of invasion, higher rate of lymph node metastasis and distant metastasis, later TNM stage, and poorer grade of differentiation.

The clinical significance of preoperative plasma fibrinogen level and platelet count in resectable esophageal squamous cell carcinoma

Background

Patients with malignant disease frequently present with activated coagulation pathways, which are potentially associated with tumor progression and prognosis. The aims of the study were to investigate the clinical significance of preoperative plasma fibrinogen level and platelet count in esophageal squamous cell carcinoma (ESCC) treated by curative surgery.

Methods

A total of 119 patients with ESCC treated by curative surgery in Qilu Hospital of Shandong University were included in the study.

Results

The preoperative plasma fibrinogen levels in the patients with ESCC ranged from 2.2 to 6.91 g/L (mean ± SD, 3.85 ± 0.95 g/L). The incidence of hyperfibrinogenemia was 43.7% (52/119, cut-off value 4.0 g/L). Hyperfibrinogenemia was found to be positively correlated with increased tumor length (P = 0.027), increased depth of invasion (P = 0.013), advanced pathological stages (P = 0.011), and disease recurrence (P = 0.026). The platelet counts ranged from 78 × 10⁹/L to 936 × 10⁹/L (mean ± SD, 254.51 ± 89.26 × 10⁹/L). The incidence of thrombocytosis was 20.2% (24/119, cut-off value 300 × 10⁹/L). Thrombocytosis was more frequently seen in male gender (P = 0.029) and non-smokers (P = 0.008). Plasma fibrinogen levels were significantly correlated with platelet counts (r = 0.018, P = 0.048). Hyperfibrinogenemia was significantly associated with poor disease-free (P = 0.009, hazard ratio (HR) = 1.784, 95% confidence interval (CI) = 1.153 to 2.761) and overall (P = 0.003, HR = 1.992, 95% CI = 1.259 to 3.152) survivals in univariate analysis, but not an independent prognostic indicator in multivariate analysis. Thrombocytosis was not significantly associated with disease-free (P = 0.765, HR = 0.918, 95% CI = 0.524 to 1.608) or overall (P = 0.809, HR = 1.072, 95% CI = 0.618 to 1.891) survivals in univariate analysis.

Conclusions

The study suggested that hyperfibrinogenemia is a valuable predictor for disease progression in ESCC. Anticoagulation therapy might be considered to control cancer progression in future studies.

Murine double minute 2 predicts response of advanced esophageal squamous cell carcinoma to definitive chemoradiotherapy

BACKGROUND

Definitive chemoradiotherapy (dCRT) has recently become one of the most effective therapies for the treatment of esophageal squamous cell carcinoma (ESCC). However, it is also true this treatment has not been effective in all patients. Therefore, it is very important to evaluate the surrogate marker of dCRT in order to improve clinical outcomes of patients with ESCC. On the other hand, our previous study had suggested that murine double minute 2 (MDM2) and p16 were associated with chemoradioresistance in ESCC.

METHODS

We selected pretreatment biopsy specimens of ESCC patients from our prospective clinical study on dCRT. Seventy-nine cases histologically diagnosed as ESCC were used. We immunohistochemically investigated these specimens using antibodies against MDM2, p53, p16, and Ki-67.

RESULTS

The patients included 68 males and 11 females with a mean age of 63.3 years. The number of patients in each clinical stage was as follows: 22 in c-Stage I; 17 in c-Stage II; and 40 in c-Stage III. cT, cN, and cStage were significantly more advanced in the Failure group (including patients with persistent and recurrent disease after dCRT) than in the complete response (CR) group (patients with persistent CR after dCRT). The clinical stage inversely correlated with the CR rate and the rescue rate after failure. The overall survival rate was significantly worse in the patients with advanced cT, cN, and cStage levels, and in the Failure group. MDM2 positivity was significantly higher in the Failure group than in the CR group in cStageIII (P = 0.014). The number of patients with an absence of p16 immunoreactivity was significantly higher in the Failure group than in the CR group in cStageIII (P = 0.010) but not in cStageI or cStageII. Moreover, the overall survival with a Ki-67 ≥ 33.7% was significantly better than that with <33.7% for patients in cStageIII (P = 0.024).

CONCLUSIONS

The results of this study suggested that MDM2 and p16 are predictive markers for chemoradioresistance in cStageIII ESCC and Ki-67 is a prognostic marker following dCRT in cStageIII ESCC. These issues could contribute to the formulation of treatment strategy for patients with advanced ESCC.

Squamous Cell Carcinoma - Similarities and Differences among Anatomical Sites

Squamous cell carcinoma (SCC) is an epithelial malignancy involving many anatomical sites and is the most common cancer capable of metastatic spread. Development of early diagnosis methods and novel therapeutics are important for prevention and mortality reduction. In this effort, numerous molecular alterations have been described in SCCs. SCCs share many phenotypic and molecular characteristics, but they have not been extensively compared. This article reviews SCC as a disease, including: epidemiology, pathology, risk factors, molecular characteristics, prognostic markers, targeted therapy, and a new approach to studying SCCs. Through this comparison, several themes are apparent. For example, HPV infection is a common risk factor among the four major SCCs (NMSC, HNSC, ESCC, and NSCLC) and molecular abnormalities in cell-cycle regulation and signal transduction predominate. These data reveal that the molecular insights, new markers, and drug targets discovered in individual SCCs may shed light on this type of cancer as a whole.

Stepwise expression of CDKN2A and RB1 proteins in esophageal mucosa from patients at high risk for squamous cell carcinoma

Squamous cell carcinoma of the esophagus is a lethal cancer and carries a poor prognosis because of late diagnosis. Identification of molecular markers may aid early diagnosis. We assessed the expression of CDKN2A/RB1 in the esophageal mucosa and its association with the histology. Esophageal biopsies were collected from 38 patients with no esophageal lesion (group 1), from iodine-negative areas of 108 alcoholics/smokers (group 2), and from tumor and nontumor areas in 41 patients with squamous cell carcinoma (group 3). The histologic diagnosis was compared with immunoexpression of CDKN2A/RB1. In group 1, histology showed normal mucosa/mild esophagitis and no expression of CDKN2A/RB1. In groups 2 and 3, the diagnosis was: normal mucosa (38.4%), esophagitis (44.4%), dysplasia and carcinoma in situ (2.8%), and carcinoma (14.3%). The immunoexpression of CDKN2A/RB1 increased in a stepwise manner from the normal mucosa, to esophagitis, dysplasia/carcinoma in situ, and carcinoma (P<0.01). CDKN2A/RB1 was not expressed in the esophageal mucosa of patients without risk factors. p16/pRb expression increased in a stepwise manner, according to the severity of histologic lesions, in biopsies from patients exposed to risk factors or with carcinoma. Esophageal mucosa exposed to risk factors with the expression of those proteins may be at risk for malignant transformation.

CtBP2 contributes to malignant development of human esophageal squamous cell carcinoma by regulation of p16INK4A

C-terminal binding protein-2 (CtBP2), as a transcriptional co-repressor, has been shown to mediate the repression of p16(INK4A) , a tumor suppressor gene product, in primary human cells. Here we aimed to investigate how the correlation between CtBP2 and p16(INK4A) influenced the development of esophageal squamous cell carcinoma (ESCC). Immunohistochemistry of ESCC tissue sections indicated that the CtBP2 and p16(INK4A) expressions were inversely correlated to each other with a linear regression coefficient of -0.747 (P < 0.05), and Western blot analysis revealed that CtBP2 was higher expressed in tumorous tissues than in adjacent non-tumorous tissues. Either CtBP2 or p16(INK4A) expression was significantly related to histological differentiation (P = 0.016 or 0.001) and to the expression of Ki-67, a proliferating marker (P = 0.006 or 0.02), and patients with higher CtBP2 and lower p16(INK4A) expressions had shorter overall survival. We also observed that CtBP2 modulated the cell proliferation and cell cycle in ECA109 cells, an ESCC cell line, by inhibiting p16(INK4A) . Overexpression or knockdown of CtBP2 in ECA109 cells was found to inhibit or activate the mRNA or protein expression of p16(INK4A) , which in turn altered the cell proliferation and cell cycle in ECA109 cells, as measured by flow cytometry and cell count assay. Additionally, after ECA109 cells silenced for CtBP2 were treated with cisplatin (an anti-ESCC agent), the p16(INK4A) expression was up-regulated, and the cell apoptosis was promoted, thus confirming the repression of p16(INK4A) by CtBP2. Collectively, all results suggested that CtBP2 might contribute to the progression of ESCC through a negative transcriptional regulation of p16(INK4A).

Bidirectional functions of arsenic as a carcinogen and an anti-cancer agent in human squamous cell carcinoma

Bidirectional cancer-promoting and anti-cancer effects of arsenic for cancer cells have been revealed in previous studies. However, each of these effects (cancer-promoting or anti-cancer) was found in different cells at different treated-concentration of arsenic. In this study, we for the first time indicated that arsenic at concentration of 3 µM, equal to average concentration in drinking water in cancer-prone areas in Bangladesh, simultaneously expressed its bidirectional effects on human squamous cell carcinoma HSC5 cells with distinct pathways. Treatment with 3 µM of arsenic promoted cell invasion via upregulation of expression of MT1-MMP and downregulation of expression of p14ARF and simultaneously induced cell apoptosis through inhibition of expression of N-cadherin and increase of expression of p21(WAF1/CIP1) at both transcript and protein levels in HSC5 cells. We also showed that inhibition of MT1-MMP expression by NSC405020 resulted in decrease of arsenic-mediated invasion of HSC5 cells involving decrease in phosphorylated extracellular signal-regulated kinases (pERK). Taken together, our biological and biochemical findings suggested that arsenic expressed bidirectional effects as a carcinogen and an anti-cancer agent in human squamous cell carcinoma HSC5 cells with distinct pathways. Our results might play an important scientific evident for further studies to find out a better way in treatment of arsenic-induced cancers, especially in squamous cell carcinoma.

The clinical significance of tumor-infiltrating neutrophils and neutrophil-to-CD8+ lymphocyte ratio in patients with resectable esophageal squamous cell carcinoma

Background

The interaction between tumor cells and inflammatory cells has not been systematically investigated in esophageal squamous cell carcinoma (ESCC). The main aims of the study were to investigate the clinical significance of tumor-infiltrating neutrophils and neturophil-to-CD8+ lymphocyte ratio (NLR), and to analyze the distribution of tumor-infiltrating neutrophils and CD8+ lymphocytes in ESCC treated by curative resection.

Methods

The expressions of CD66b and CD8 were assessed with double staining immunohistochemistry in the surgical specimens from 90 patients with ESCC treated by curative surgery.

Results

We showed that increased intratumoral neutrophils were significantly associated with lymph node metastasis (P = 0.016), and advanced pathological stages (P = 0.013). Decreased peritumoral CD8+ lymphocyte density was more frequently observed in patients with single positive lymph node (p = 0.045). Peritumoral NLR was significantly associated with advanced T stages (p < 0.001), lymph node metastasis (p = 0.041) and a trend towards advanced pathological stages (p = 0.053). Increased intratumoral neutrophils were significantly associated with decreased disease-free survival (p < 0.001) and overall survival (p < 0.001) in univariate analysis and were identified as an independent prognostic factor for disease-free survival (p = 0.006) and overall survival (p = 0.037) in multivariate analysis. Neither the density nor the distribution of tumor-infiltrating neutrophils was significantly correlated with that of CD8+ lymphocytes. The density of intratumoral CD8+ lymphocytes was significantly lower than (P < 0.001) and moderately correlated with (r = 0.434, p < 0.001) that in peritumoral area.

Conclusions

Increased intratumoral neutrophils were an independent poor prognostic factor and peritumoral NLR was significantly associated with disease progression in ESCC treated by curative surgery, suggesting the possible effect of immune misbalance of tumor microenvironment in facilitating ESCC progression. Immunotherapy targeted to the above predictors should be considered in the future.

Systematic review and meta-analysis of tumor biomarkers in predicting prognosis in esophageal cancer

BACKGROUND

Esophageal cancer (EC) is a frequently occurring cancer with poor prognosis despite combined therapeutic strategies. Many biomarkers have been proposed as predictors of adverse events. We sought to assess the prognostic value of biomarkers in predicting the overall survival of esophageal cancer and to help guide personalized cancer treatment to give patients the best chance at remission.

METHODS

We conducted a systematic review and meta-analysis of the published literature to summarize evidence for the discriminatory ability of prognostic biomarkers for esophageal cancer. Relevant literature was identified using the PubMed database on April 11, 2012, and conformed to the REMARK criteria. The primary endpoint was overall survival and data were synthesized with hazard ratios (HRs).

RESULTS

We included 109 studies, exploring 13 different biomarkers, which were subjected to quantitative meta-analysis. Promising markers that emerged for the prediction of overall survival in esophageal squamous cell cancer included VEGF (18 eligible studies, n=1476, HR=1.85, 95% CI, 1.55-2.21), cyclin D1 (12 eligible studies, n=1476, HR=1.82, 95% CI, 1.50-2.20), Ki-67 (3 eligible studies, n=308, HR=1.11, 95% CI, 0.70-1.78) and squamous cell carcinoma antigen (5 eligible studies, n=700, HR=1.28, 95% CI, 0.97-1.69); prognostic markers for esophageal adenocarcinoma included COX-2 (2 eligible studies, n=235, HR=3.06, 95% CI, 2.01-4.65) and HER-2 (3 eligible studies, n=291, HR=2.15, 95% CI, 1.39-3.33); prognostic markers for uncategorized ECs included p21 (9 eligible studies, n=858, HR=1.27, 95% CI, 0.75-2.16), p53 (31 eligible studies, n=2851, HR=1.34, 95% CI, 1.21-1.48), CRP (8 eligible studies, n=1382, HR=2.65, 95% CI, 1.64-4.27) and hemoglobin (5 eligible studies, n=544, HR=0.91, 95% CI, 0.83-1.00).

CONCLUSIONS

Although some modest bias cannot be excluded, this review supports the involvement of biomarkers to be associated with EC overall survival.

p14ARF repression induced by promoter methylation associated with metastasis in esophageal squamous cell carcinoma

The objective of this study is to evaluate the promoter methylation status of the p14ARF in esophageal squamous cell carcinoma (ESCC). Cell lines were treated with the demethylation agent 5-aza-2'-deoxycytidine, and p14ARF messenger RNA (mRNA) expression was detected by reverse transcription-polymerase chain reaction. We analyzed the methylation status of p14ARF promoter by methylation-specific polymerase chain reaction in 50 ESCC and their noncarcinoma tissues. Then demethylation caused by 5-aza-2'-deoxycytidine increased the p14ARF mRNA expression level in esophagus cancer cell lines. p14ARF methylation was found in 48% (24 of 50) of ESCC patients but only in 18% (9 of 50) corresponding noncarcinoma tissues (P = 0.001). There was a statistically significant correlation between the presence of methylation and tumor metastasis (P < 0.001). The p14ARF mRNA was lower in ESCC tissues than nontumor tissues (mean ± standard deviation, 0.47 ± 0.32 vs. 1.40 ± 0.58; P = 0.002). Meanwhile, a signification association was found between the methylation status of p14ARF promoter and p14ARF mRNA expression in tissues (P < 0.05). The aberrant promoter methylation of p14ARF is a common phenomenon in ESCC, which may be an important mechanism of downregulating p14ARF mRNA expression.

MDM2 is overexpressed and regulated by the eukaryotic translation initiation factor 4E (eIF4E) in human squamous cell carcinoma of esophagus

BACKGROUND

We investigated the association between the increased eukaryotic translation initiation factor 4E (eIF4E) level and MDM2 overexpression in the esophageal cancer tissue and cells.

METHODS

This was a retrospective study of specimens from esophageal cancer patients treated over a 5-year period in a Taiwan university hospital. The predictor variable was eIF4E level in esophageal tumors and CE48T/VGH and TE6 esophageal carcinoma cell lines. The main outcome variable was MDM2 overexpression. Appropriate descriptive and univariate statistics were computed, and a P value of <0.05 was considered statistically significant.

RESULTS

There were two study sample groups. Immunohistochemistry analyses of the first sample group (51 esophageal tumors) revealed that 19 specimens demonstrated MDM2 elevation and 20 specimens had eIF4E overexpression. eIF4E elevation was evidenced by accumulation of the protein in the cytoplasm. There was a significant association between the eIF4E and MDM2 expression (P < 0.001). Western blot analysis and semiquantitative reverse transcriptase-polymerase chain reaction of the second specimen group (20 pairs of tumors and normal tissues) revealed the co-elevation of MDM2 and eIF4E (P = 0.008). There was no increased mdm2 transcript in most of the specimens. Without significant alterations in the mdm2 mRNA level and subcellular distribution, MDM2 protein was upregulated in CE48T/VGH cultured cells expressing ectopic eIF4E. Conversely, reduction of eIF4E by specific siRNA enabled TE6 cells synthesizing reduced amounts of MDM2.

CONCLUSIONS

Our findings indicate that MDM2 protein levels are strongly associated with and regulated by eIF4E in a posttranscriptional mechanism in esophageal cancer.