Recent Advances From Basic and Clinical Studies of Esophageal Squamous Cell Carcinoma

Long noncoding RNAs are novel potential prognostic biomarkers for esophageal squamous cell carcinoma: an overview

Esophageal squamous cell carcinoma (ESCC) still has a poor prognosis. The prognostic biomarkers of ESCC are not yet well established. Long noncoding RNAs (lncRNAs) have recently been intensively investigated in various cancers including ESCC, and are found to be closely correlated to ESCC. Dysregulated expression of lncRNAs was widely observed in ESCC tumor tissue and was closely related to the tumorigenesis and progression of ESCC. More and more studies have found that lncRNAs were significantly correlated with the prognosis and diagnosis of patients with ESCC. Therefore, all those accumulating evidence indicated that lncRNAs could serve as a prognostic biomarker of ESCC. In this, we summarized the relation between lncRNAs and ESCC as well as the potential biomarker role of lncRNAs in ESCC, especially the prognostic value of lncRNAs. Our current review highlighted the need of further studies to explore the biomarker functions as well as therapeutic values of lncRNAs in ESCC.

Coexpression of periostin and EGFR in patients with esophageal squamous cell carcinoma and their prognostic significance

BACKGROUND

Both periostin (PN) and epidermal growth factor receptor (EGFR) can predict the prognosis of several carcinomas alone. However, coexpression of PN and EGFR in esophageal squamous cell carcinoma (ESCC) still remains unknown. We aimed to clarify their relationship with clinicopathological factors and prognostic significance of their coexpression in ESCC.

PATIENTS AND METHODS

In this single-center retrospective study, immunohistochemistry was performed to evaluate the expression of PN and EGFR in ESCC and paracarcinomatous tissues of 83 patients. The quantitative expression levels of PN and EGFR were examined in two ESCC and tumor-adjacent tissues. The levels of PN and EGFR expression were correlated with clinicopathological parameters by the χ (2) or Kruskal-Wallis method. Spearman's rank correlation test was performed to determine the relationship between PN and EGFR expression levels. Kaplan-Meier and Cox regression analyses were used to detect the prognostic factors of disease-free survival (DFS) and overall survival (OS).

RESULTS

The high expression of PN protein in ESCC tissues was significantly associated with tumor length (P=0.044), differentiation grade (P=0.003), venous invasion (P=0.010), invasion depth (P=0.007), lymphatic metastasis (P=0.000), and tumor stage (P=0.000). The high expression of EGFR protein in ESCC tissues was only significantly related to lymphatic metastasis (P=0.000), invasion depth (P=0.022), and tumor stage (P=0.000). Kaplan-Meier analysis showed that high expression of PN was closely correlated to reduced OS (P=0.000) and DFS (P=0.000), which was consistent with EGFR expression. Cox regression analysis identified PN and EGFR as independent poor prognostic factors of OS and DFS in the ESCC patients (P<0.05). Moreover, the risk of death for the ESCC patients with low expression of two biomarkers and high expression of single biomarker was 0.243 times (P=0.000) and 0.503 times (P=0.030), respectively, than that for patients with high expression of two biomarkers.

CONCLUSION

PN and EGFR are related to miscellaneous clinicopathologic characteristics. Coexpression of PN and EGFR is more closely to be of predictive value on ESCC development and progression, which may offer a novel and potential target strategy for ESCC treatment in the future.

Somatically Acquired LINE-1 Insertions in Normal Esophagus Undergo Clonal Expansion in Esophageal Squamous Cell Carcinoma

Squamous cell carcinoma of the esophagus (SCC) is the most common form of esophageal cancer in the world and is typically diagnosed at an advanced stage when successful treatment is challenging. Understanding the mutational profile of this cancer may identify new treatment strategies. Because somatic retrotransposition has been shown in tumors of the gastrointestinal system, we focused on LINE-1 (L1) mobilization as a source of genetic instability in this cancer. We hypothesized that retrotransposition is ongoing in SCC patients. The expression of L1 encoded proteins is necessary for retrotransposition to occur; therefore, we evaluated the expression of L1 open reading frame 1 protein (ORF1p). Using immunohistochemistry, we detected ORF1p expression in all four SCC cases evaluated. Using L1-seq, we identified and validated 74 somatic insertions in eight tumors of the nine evaluated. Of these, 12 insertions appeared to be somatic, not genetically inherited, and sub-clonal (i.e., present in less than one copy per genome equivalent) in the adjacent normal esophagus (NE), while clonal in the tumor. Our results indicate that L1 retrotransposition is active in SCC of the esophagus and that insertion events are present in histologically NE that expands clonally in the subsequent tumor.

Rare tumors of esophageal squamous mucosa

In spite of increasing incidence of esophageal adenocarcinoma in the last few decades, esophageal squamous cell carcinoma (SCC) still remains the dominant subtype of esophageal cancer worldwide. Apart from conventional SCC, some rare unconventional tumors of esophageal squamous mucosa are also well known. This study provides an introduction to these and presents a brief review of the literature, including the diagnostic and prognostic importance of each variant.

The association between four SNPs of X-ray repair cross complementing protein 1 and the sensitivity to radiotherapy in patients with esophageal squamous cell carcinoma

Early stage diagnosis and therapeutic outcomes of esophageal squamous cell carcinoma remain poor. In order to evaluate the association between 4 single nucleotide polymorphisms (SNPs) of X-ray repair cross complementing protein 1 (XRCC1) and the sensitivity to radiotherapy in patients with esophageal squamous cell carcinoma (ESCC), the present study identified 4 SNPs of XRCC1 and evaluated the distribution of these genotypes among patients with ESCC. Venous blood samples from 175 patients with ESCC were collected and DNA was extracted. The 4 SNPs of the XRCC1 gene fragment were amplified using three primer pairs, which were sequenced. The mismatches were analyzed and identified using Basic Local Alignment Search Tool software. The sensitivity to radiotherapy was graded as effective and non-effective, according to the treatment results of the patients. The present study successfully amplified and sequenced 4 SNPs of XRCC1 in 112 out of the 175 patients with ESCC. The effective response rate of radiotherapy was 84.8% among the 112 patients. The effective response rate of patients with no mutation in the SNPs was 74.3%, and the rate increased to 89.6% in patients that had ≥1 mutation out of the 4 SNPs (χ2=4.389; P=0.036). For G28152A and G28152A mutations the effective response rate of patients was 91.2% (χ2=4.014; P=0.045) and 91.5% (χ2=4.451; P=0.035), respectively, which was significantly different compared to patients with no mutation (P=0.045 and P=0.035, respectively). The present results suggest that the 4 SNPs of XRCC1 are associated with the effective response rate of radiotherapy in patients with ESCC. The mutation of SNP G28152A was particularly important and may be a potential genomic predictor for radiotherapy sensitivity in patients with ESCC.

BC200 LncRNA a potential predictive marker of poor prognosis in esophageal squamous cell carcinoma patients

OBJECTIVE

To explore the expression and prognosis significance of BC200 in esophageal squamous cell carcinoma (ESCC) patients who received radical resection.

METHODS

We used quantitative real-time polymerase chain reaction to detect the expression level of BC200 in cancer tissue and paired adjacent normal tissue samples from 70 ESCC patients who received radical surgical resection and analyzed the correlation of the relative expression level of BC200 with clinical-pathological features and prognosis.

RESULTS

We found that the relative expression of BC200 was significantly higher in ESCC tissues compared with adjacent normal tissue samples (P=0.023). But the expression of BC200 were not related to clinical-pathological features, such as age, TNM stages, and histological grade (P>0.05). Kaplan-Meier analysis showed that high expression levels of BC200 were correlated with poor prognosis in ESCC patients. Patients with a high level of BC200 had a shorter disease-free survival and overall survival than those with low BC200 expression (P=0.034 and P=0.031, respectively). On multivariate analysis, the hazard ratio (HR) of BC200 expression was 2.17 (95% confidence interval [CI]=1.12-4.19, P=0.022) for disease-free survival and 2.24 (95% CI=1.12-4.49, P=0.023) for overall survival.

CONCLUSION

Our results indicate that high expression of BC200 reflects poor prognosis and could serve as a novel predictive marker for ESCC patients who received radical resection.