Significance of CD133 expression in esophageal squamous cell carcinoma

Prognostic and clinicopathological value of Ki-67 in patients with oesophageal squamous cell carcinoma: a systematic review and meta-analysis

OBJECTIVES

The relationship between Ki-67 expression and the prognosis of patients with oesophageal squamous cell carcinoma (ESCC) has been extensively studied. However, their findings were inconsistent. Consequently, the present meta-analysis was performed to identify the precise value of Ki-67 in predicting the prognosis of ESCC.

DESIGN

The current meta-analysis was carried out in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

DATA SOURCES

Electronic databases of PubMed, Embase, Web of Science and Cochrane Library were systematically searched until 26 September 2023.

STATISTICAL METHODS

Pooled HRs and corresponding 95% CIs were calculated to estimate the role of Ki-67 in predicting overall survival (OS) and disease-free survival (DFS) in ESCC. Between-study heterogeneity was evaluated using Cochrane's Q test and I2 statistics. Specifically, significant heterogeneities were identified based on p<0.10 on the Q statistic test or I2>50% so the random-effects model should be used; otherwise, the fixed-effects model should be used. The relationship between Ki-67 and clinicopathological characteristics of ESCC was evaluated by combining ORs with their corresponding 95% CIs.

RESULTS

11 articles with 1124 patients were included in the present meta-analysis. Based on our analysis, increased Ki-67 expression was markedly associated with poor OS (HR 1.62, 95% CI 1.15 to 2.28, p=0.006) and DFS (HR 1.72, 95% CI 1.22 to 2.43, p=0.002) in ESCC. Moreover, subgroup analysis revealed that Ki-67 upregulation significantly predicted OS and DFS when a Ki-67 threshold of >30% was used. Nonetheless, Ki-67 was not significantly associated with sex, T stage, N stage, TNM stage, tumour differentiation or tumour location.

CONCLUSIONS

In the present meta-analysis, high Ki-67 expression significantly predicted OS and DFS in patients with ESCC, especially when Ki-67>30% was used as the threshold. These results suggest that Ki-67 could serve as an effective and reliable prognostic indicator for ESCC.

PFKFB3 works on the FAK-STAT3-SOX2 axis to regulate the stemness in MPM

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm and often acquires chemoresistance by increasing stemness in tumour tissue, thereby generating cancer stem cells (CSCs). CSCs escape treatment by deploying metabolic pathways to trigger dormancy or proliferation, also gaining the ability to exit and re-enter the cell cycle to hide their cellular identity.

METHODS

We employed various cellular and biochemical assays to identify the role of the glycolytic enzyme PFKFB3, by knocking it down and pharmacologically inhibiting it with PFK158, to determine its anticancer effects in vitro and in vivo by targeting the CSC population in MPM.

RESULTS

Here, we have identified PFKFB3 as a strategic player to target the CSC population in MPM and demonstrated that both pharmacologic (PFK158) and genetic inhibition of PFKFB3 destroy the FAK-Stat3-SOX2 nexus resulting in a decline in conspicuous stem cell markers viz. ALDH, CD133, CD44, SOX2. Inhibition of PFKFB3 accumulates p21 and p27 in the nucleus by decreasing SKP2. Lastly, PFK158 diminishes tumour-initiating cells (TICs) mediated MPM xenograft in vivo.

CONCLUSIONS

This study confers a comprehensive and mechanistic function of PFKFB3 in CSC maintenance that may foster exceptional opportunities for targeted small molecule blockade of the TICs in MPM.

Oral Cancer Stem Cells: Therapeutic Implications and Challenges

Head and neck squamous cell carcinoma (HNSCC) is currently one of the 10 most common malignancies worldwide, characterized by a biologically highly diverse group of tumors with non-specific biomarkers and poor prognosis. The incidence rate of HNSCC varies widely throughout the world, with an evident prevalence in developing countries such as those in Southeast Asia and Southern Africa. Tumor relapse and metastasis following traditional treatment remain major clinical problems in oral cancer management. Current evidence suggests that therapeutic resistance and metastasis of cancer are mainly driven by a unique subpopulation of tumor cells, termed cancer stem cells (CSCs), or cancer-initiating cells (CICs), which are characterized by their capacity for self-renewal, maintenance of stemness and increased tumorigenicity. Thus, more understanding of the molecular mechanisms of CSCs and their behavior may help in developing effective therapeutic interventions that inhibit tumor growth and progression. This review provides an overview of the main signaling cascades in CSCs that drive tumor repropagation and metastasis in oral cancer, with a focus on squamous cell carcinoma. Other oral non-SCC tumors, including melanoma and malignant salivary gland tumors, will also be considered. In addition, this review discusses some of the CSC-targeted therapeutic strategies that have been employed to combat disease progression, and the challenges of targeting CSCs, with the aim of improving the clinical outcomes for patients with oral malignancies. Targeting of CSCs in head and neck cancer (HNC) represents a promising approach to improve disease outcome. Some CSC-targeted therapies have already been proven to be successful in pre-clinical studies and they are now being tested in clinical trials, mainly in combination with conventional treatment regimens. However, some studies revealed that CSCs may not be the only players that control disease relapse and progression of HNC. Further, clinical research studying a combination of therapies targeted against head and neck CSCs may provide significant advances.

Effect of Linc-POU3F3 on radiotherapy resistance and cancer stem cell markers of esophageal cancer cells

OBJECTIVES

Long non-coding RNA (LncRNA) is an important transcriptional and post-transcriptional regulatory molecule in the body. In recent years, relationship between LncRNA and malignant phenotype of tumor cells has been revealed gradually. This study aims to investigate the expression characteristics of pit-oct-unc class 3 homeobox 3 related long non-coding RNA (Linc-POU3F3) in esophageal cancer and its relationship with radiation resistance (IR) as well as the expressions of cancer stem cell (CSC) markers in esophageal cancer cells.

METHODS

The expression characteristics and potential interaction molecules of Linc-POU3F3 in esophageal cancer were collected from the public database via bioinformatics retrieval. Forty-two pair samples of esophageal cancer tissues and corresponding adjacent tissues were collected. Human normal esophageal epithelial cells (HEEC) and human esophageal cancer cell lines (ECA109, TE-1, TE-2, TE-13) were cultured. Real-time quantitative PCR (qPCR) was used to detect the expression level of Linc-POU3F3 in clinical tissues and cells. The formation of TE-13 IR cell line induced by different doses of radiation served as IR group cells, and the same condition treated with 0 Gy dose was set as control group (control) cells. Meanwhile, we used cell transfection technology to construct random interference sequence (siControl) cells and interference (siLinc-POU3F3) cells. In ECA109 cells, we transfected blank and over expressed Linc-POU3F3 plasmids as vector and over-expressed group (oeLinc-POU3F3). The mRNA and protein expressions of CD44, CD133 and CD90 were detected by qPCR and Western blotting, respectively. MTS [3-(4,5-dimenthylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] was used to detect the cell viability under different radiation doses, and the resistance of IR cells was verified by clone formation experiment.

RESULTS

The expression of Linc-POU3F3 was correlated with the tumor progression and poor prognosis of esophageal cancer. The level of Linc-POU3F3 mRNA expression was significantly higher in esophageal cancer tissues and cell lines than that in normal adjacent tissues and cell lines (all P<0.01). The expressions of Linc-POU3F3 mRNA and protein expressions of CD44, CD133, and CD90 in IR cells were significantly higher than those in control cells (all P<0.01). The expression of Linc-POU3F3 in siLinc-POU3F3 cell was significantly lower than that in the siControl cells (P<0.01), and the inhibition rate was 87.21%. The mRNA and protein expressions of CD44, CD133, and CD90 in the siLinc-POU3F3 cells were significantly lower than those in the siControl cells (all P<0.05). The expressions of linc-POU3F3, CD44, CD133, and CD90 mRNA and protein in the oeLinc-POU3F3 cells were significantly higher than those in the vector cells. The relative activity and clone formation ability in the IR cells were significantly higher than those in the control cells at 2, 4, and 8 Gy doses (all P<0.01). The relative activity in the siLinc-POU3F3 cells was significantly lower than that in the siControl cells at 4 and 8 Gy doses (P<0.01). The relative activity in the oeLinc-POU3F3 cells was significantly higher than that in the vector cells at 4 and 8 Gy doses (P<0.01).

CONCLUSIONS

Linc-POU3F3 is up-regulated in esophageal cancer and can promote IR and the expression of CSC markers in esophageal cancer cells.

Expression of CD44 and CD133 stem cell markers in squamous cell carcinoma of esophagus

Context

Role of cancer stem cells in the esophageal carcinogenesis is not clear.

Aim

To assess the expression of CD44 and CD133 cancer stem cell markers in esophageal squamous cell carcinoma (ESCC) and its predisposing lesions by immunohistochemistry.

Setting and Design

Prospective study as a part of an intramural research project.

Materials and Methods

Tissues samples were obtained with endoscopic biopsy and from surgically resected esophageal specimens. Fifty cases each of histopathologically diagnosed cases of esophageal squamous cell carcinoma and its predisposing lesions (mild, moderate, and severe dysplasia and esophagitis) were evaluated for stem cell marker CD44 and C133 by immunohistochemistry using a scoring system.

Statistical Analysis

Chi-square test, analysis of variance (ANOVA), post-hoc tests (Tukey-HSD) were used as appropriate for data analysis. Two sided P < 0.05 was considered as significant.

Results

CD44 expression was significantly higher in ESCC as compared to dysplasia and esophagitis (mean IS 7.92 ± 1.45 vs. 6.34 ± 0.80 vs 5.15 ± 0.86 respectively, P < 0.001). CD133 expression was also significantly higher in ESCC as compared to dysplasia (mean IS 6.82 ± 1.57 vs. 1.00 ± 0.00 respectively, P < 0.001) while esophagitis showed no expression. CD44 and CD133 expressions were significantly higher in poorly differentiated ESCC than moderately differentiated and well differentiated lesions (CD44 mean IS 6.94 ± 1.44 vs 8.17 ± 1.38 vs. 8.63 ± 1.02 respectively, P < 0.001 and CD 133 mean IRS 5.63 ± 0.81 vs 6.00 ± 00 vs. 9.0 ± 00 respectively, P < 0.001).

Conclusion

Significantly higher expression of CD44 and CD133 cancer stem cell markers in ESCC as compared to its predisposing lesions (esophagitis and dysplasia) suggests its role in esophageal carcinogenesis.

CD133 Role in Oral Carcinogenesis

Objective:

to investigate CD133 immunoexpression, cancer stem cells marker, in oral epithelial dysplasias (OEDs) and oral squamous cells carcinomas (OSCCs) and understandits possible involvement in the malignant transformation process of these lesions and to better elucidate their biological behavior.

Material and methods:

Tissue samples of 15 cases of OSCCs and 15 OEDs were subjected to CD133 antibody immunohistochemistry reactions. The analysis used quantitative parameters (number of immunostained cells regardless of immunostaining sublocations).

Results:

All samples of OSCCs and OEDs showed positive immunostaining, with no significant difference between these groups (p = 0.283). We did not observe statistical difference between the degree of dysplasia and the amount of CD133+ cells (p = 0.899). CD133 immunoexpression showed no association with the OEDs and OSCCs sites. It was observed that nuclear and cytoplasmic immunostaining was more evident with the progression of the malignant process.

Conclusion:

It is suggested that the CD133 cellular localization together with the histopathological criteria of OEDs classification can contribute to provide more concrete indications about the oral carcinogenesis process.

Prognostic value of stem cell markers in esophageal and esophagogastric junction cancer: a meta-analysis

Background: Esophageal cancer is an aggressive tumor, with poor prognosis and low survival rates. Although diagnosis and treatment have improved considerably, more efficient prognostic factors are urgently needed to prevent postoperative recurrence and metastasis. Cancer stem cells are key players in tumor progression and several studies have investigated the association between the expression of stemness genes and clinical outcome. However, the prognostic value of stemness markers in esophageal cancer remains controversial. We identified six factors involved in angiogenesis, anti-apoptosis and self-renewal that have been associated to poor prognosis in other types of cancer. We conducted a review of the literature and a meta-analysis to assess their potential prognostic role in this malignancy.

Material and Methods: The database of PMC, PubMed, Web of Science, Embase and The Cochrane Library were searched to investigate the association between CD34, CD133, Nucleostemin, OCT-4, NANOG and CD90, and the survival of patients affected by esophageal squamous cell carcinoma or esophageal adenocarcinoma. Among the 615 eligible studies, a total of 19 articles (including 1586 patients) met the inclusion criteria for the meta-analysis, and the pooled hazard ratio and 95% confidence intervals were calculated.

Results: Data showed that high expression of CD34 (HR 2.10; 95%CI 1.41-3.14; I²=56%; p=0.0003), CD133 (HR 1.91; 95%CI 1.15-3.19; I²=55%; p=0.01) and Nucleostemin (HR 2.97; 95%CI 1.11-7.98; I²=0%; p=0.03) were associated with poor prognosis in patients affected by esophageal cancer. The expression of NANOG and OCT-4 showed no significant association with survival of patients, whereas no study involving CD90 was included in this meta-analysis. Conclusion: CD34, CD133 and Nucleostemin might represent useful prognostic markers in patients affected by esophageal cancer.

Clinical implications of cancer stem cells in digestive cancers: acquisition of stemness and prognostic impact

Digestive system cancers are the most frequent cancers worldwide and often associated with poor prognosis because of their invasive and metastatic characteristics. Recent studies have found that the plasticity of cancer cells can impart cancer stem-like properties via the epithelial-mesenchymal transition (EMT). Cancer stem-like properties such as tumor initiation are integral to the formation of metastasis, which is the main cause of poor prognosis. Numerous markers of cancer stem cells (CSCs) have been identified in many types of cancer. Therefore, CSCs, via their stem cell-like functions, may play an important role in prognosis after surgery. While several reports have described prognostic analysis using CSC markers, few reviews have summarized CSCs and their association with prognosis. Herein, we review the prognostic potential of eight CSC markers, CD133, CD44, CD90, ALDH1A1, EPCAM, SOX2, SOX9, and LGR5, in digestive cancers including those of the pancreas, colon, liver, gastric, and esophagus.

Detention and Identification of Cancer Stem Cells in Esophageal Squamous Cell Carcinoma

Cancer stem cells (CSCs) are a small subpopulation of cells associated with cancer initiation, progression, metastasis, therapy resistant, and recurrence. In esophageal squamous cell carcinoma (ESCC), several cell surface and intracellular markers, for example, CD44, ALDH, Pygo2, MAML1, Twist1, Musashi1, side population (SP), CD271, and CD90, have been proposed to identify CSCs. In addition, stem cell markers such as ALDH1, HIWI, Oct3/4, ABCG2, SOX2, SALL4, BMI-1, NANOG, CD133, and podoplanin were associated with pathological stages of cancer, cancer recurrence, prognosis, and therapy resistance of patients with ESCC. Identification and isolation of CSCs could play an important part of improved cancer management regime in ESCC. Furthermore, CSCs may be used as the predictive tool for chemoradiotherapy response in ESCC. Different methods such as in vitro functional assays, cell sorting using various intracellular, and cell surface markers and xenotransplantation techniques are frequently used for the identification and isolation of CSCs in different cancers, including ESCC. However, none of these methods solely can guarantee complete isolation of CSC population. Therefore, a combination of methods is used for reliable detection and isolation of CSCs. Herein, we describe the identification and isolation of CSCs from ESCC cells by cell sorting after Hoechst 33342 staining followed by in vitro functional assays and in vivo mouse xenotransplantation techniques.

Targeting cancer stem cells in squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive tumor and the sixth most common cancer worldwide. Current treatment strategies for HNSCC are surgery, radiotherapy, chemotherapy, immunotherapy or combinatorial therapies. However, the overall 5-year survival rate of HNSCC patients remains at about 50%. Cancer stem cells (CSCs), a small population among tumor cells, are able to self-renew and differentiate into different tumor cell types in a hierarchical manner, similar to normal tissue. In HNSCC, CSCs are proposed to be responsible for tumor initiation, progression, metastasis, drug resistance, and recurrence. In this review, we discuss the molecular and cellular characteristics of CSCs in HNSCC. We summarize current approaches used in the literature for identification of HNSCC CSCs, and mechanisms required for CSC regulation. We also highlight the role of CSCs in treatment failure and therapeutic targeting options for eliminating CSCs in HNSCC.

Cancer Stem Cells in Head and Neck Carcinomas: Identification and Possible Therapeutic Implications

The recurrence and/or lack of response of certain tumors to radio- and chemotherapy has been attributed to a small subpopulation of cells termed cancer stem cells (CSCs). CSCs have been identified in many tumors (including solid and hematological tumors). CSCs are characterized by their capacity for self-renewal, their ability to introduce heterogeneity within a tumor mass and its metastases, genomic instability, and their insensitivity to both radiation and chemotherapy. The latter highlights the clinical importance of studying this subpopulation since their resistance to traditional treatments may lead to metastatic disease and/or tumor relapse. Head and neck squamous cell carcinomas (HNSCCs) are the sixth most common malignancy worldwide with the highest incidence occurring in East Asia and eastern and southern Africa. Several cellular subpopulations believed to have CSC properties have been isolated from HNSCCs, but at present, identification and characterization of CSCs remains an experimental challenge with no established or standardized protocols in place to confirm their identity. In this review we discuss current approaches to the study of CSCs with a focus on HNSCCs, particularly in the context of what this might mean from a therapeutic perspective.

The transcription factor LEF1 promotes tumorigenicity and activates the TGF-β signaling pathway in esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is the most difficult subtype of esophageal cancer to treat due to the paucity of effective targeted therapy. ESCC is believed to arise from cancer stem cells (CSCs) that contribute to metastasis and chemoresistance. Despite advances in diagnosis and treatment, the prognosis of ESCC patients remains poor.

Methods

In this study, we applied western blot, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry, RNA-Seq analysis, luciferase reporter assay, Chip-qPCR, bioinformatics analysis, and a series of functional assays to show the potential role of LEF1 in regulating esophageal CSCs.

Results

We found that the overexpression of LEF1 was associated with aberrant clinicopathological characteristics and the poor prognosis of ESCC patients. In addition, the elevated expression of LEF1 and OV6 was significantly associated with aberrant clinicopathological features, and poor patient prognosis. Moreover, the overexpression of LEF1 was observed in esophageal CSCs purified by the magnetic sorting of adherent and spheroidal ESCC cells. The increased level of LEF1 in CSCs facilitated the expression of CSC markers, stem cell-like properties, resistance to chemotherapy, and tumorigenicity and increased the percentage of CSCs in ESCC samples. Conversely, the knockdown of LEF1 significantly diminished the self-renewal properties of ESCC. We showed that LEF1 played an important mechanical role in activating the TGF-β signaling pathway by directly binding to the ID1 gene promoter. A positive association between LEF1 and ID1 expression was also observed in clinical ESCC samples.

Conclusion

Our results indicate that the overexpression of LEF1 promotes a CSC-like phenotype in and the tumorigenicity of ESCC by activating the TGF-β signaling pathway. The inhibition of LEF1 might therefore be a novel therapeutic target to inactivate CSCs and inhibit tumor progression.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1296-7) contains supplementary material, which is available to authorized users.

PRMT1 regulates the tumour-initiating properties of esophageal squamous cell carcinoma through histone H4 arginine methylation coupled with transcriptional activation

Esophageal squamous cell carcinoma (ESCC) is the most difficult subtype of esophageal cancer to treat due to a paucity of effective targeted therapy. ESCC is believed to arise from tumour initiating cells (TICs), which contribute to metastasis and chemoresistance. In this study, we found that Protein arginine methyltransferase 1(PRMT1) was highly expressed in ESCCs and associated with aberrant clinicopathological characteristics of ESCC patients. In ESCC specimens, the elevated expression of PRMT1 and OV6 was significantly associated with histologic grade, TNM stage and poor patient prognosis. Moreover, overexpression of PRMT1 was observed in esophageal TICs purified by magnetic sorting of adherent and spheroid ECA109/TE1 cells. The increased level of PRMT1 in TICs facilitated the expression of TIC markers, stem cell-like properties, resistance to chemotherapy, tumorigenicity and increased their percentages in ECSS samples. Conversely, knockdown of PRMT1 significantly diminished the self-renewal properties of ESCC. Moreover, we show that PRMT1 can catalyse histone H4R3 asymmetric dimethylation and promote transcription activation of down-stream genes. Further RNA-Seq transcriptome analysis reveals that overexpression of PRMT1 in ESCC cell lines activates Wnt/β-catenin and Notch signaling pathway. Together, our studies highlight that PRMT1 activates and maintains esophageal TICs by mediating transcription alteration through histone H4 arginine methylation.

IGF2 induces CD133 expression in esophageal cancer cells to promote cancer stemness

Failure to eradicate cancer stem cells (CSC) during primary therapy may lead to cancer recurrence. We recently reported that CD133 is a functional biomarker for CSCs in esophageal squamous cell carcinoma (ESCC) but the molecular pathways critical for maintenance of CD133-positive CSCs are largely unknown. Here, we revealed that knockdown of IGF2 or treatment with PI3K/AKT inhibitors markedly inhibited the abilities of CD133-positive ESCC cells to self-renew, resist chemotherapeutic drugs, and form tumors. Further functional analysis identified miR-377 as a downstream regulator of PI3K/AKT signaling, and a mediator of the effects of IGF2 on CD133 expression and CSC properties. We found that the expression levels of IGF2 and CD133 were positively correlated with each other in primary ESCC, and that concurrent elevation of IGF2 and CD133 expression was significantly associated with poor patient survival. Furthermore, in vivo experiments demonstrated that IGF2-neutralizing antibody enhanced the sensitivity of tumor xenografts in nude mice to 5-fluorouracil treatment. This study underpins the importance of the IGF2-PI3K/AKT-miR-377-CD133 signaling axis in the maintenance of cancer stemness and in the development of novel therapeutic strategy for treatment of esophageal cancer.

Clinical significances of p27 in digestive tract cancers: a comprehensive analysis on immunohistochemistry staining, published literatures, microarray and RNA-seq data

In the present study, we conducted a comprehensive analysis on the clinical roles of p27 protein and p27 gene in digestive tract cancers (DTCs). First, we performed immunohistochemistry staining and found that p27 protein was down-regulated in DTCs. Then we collected 62 publications and calculated the combined hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (95% CIs) to clarify the relationships of p27 protein expression with prognoses and clinicopathological parameters. The overall HRs indicated that the down-regulated p27 protein was an independent prognostic biomarker for overall survival (HR: 1.58, 95% CI: 1.38-1.81, P < 0.0001) but not for disease-free survival and cancer-specific survival. The combined ORs indicated that a low expression of p27 protein was positively related to lymph node metastasis (OR: 2.15, 95% CI: 1.57-2.96, P < 0.0001), distant metastasis (OR: 2.02, 95% CI: 1.12-3.63, P = 0.019) and pathology grading (OR: 2.14, 95% CI: 1.75-2.62, P < 0.0001). Additionally, 60 DTCs-related microarray and RNA-seq datasets were obtained to investigate the expression level and clinical value of p27 gene in DTCs patients. We found that the expression level of p27 gene in DTCs was similar to that in normal controls. And no significant associations of p27 gene expression with prognoses and clinicopathological factors were observed. In conclusion, according to our results, it was p27 protein, but not p27 gene, that can function as an effective biomarker to predict the clinical outcome in patients with DTCs. The down-regulation of p27 protein in DTCs may not result from the altered expression of p27 gene.

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.

Expression and significance of GRHL2 in esophageal cancer

Esophageal cancer (EC) is one of the most common causes of cancer-related mortality in the world. Although much effort has been made to improve the 5-year survival rate of patients with EC, it still remains low due to diagnosis at an advanced stage, aggressive local invasion, early metastasis, and resistance to chemotherapy. Although grainyhead-like 2 (GRHL2) has attracted interest since it has been recently identified as a novel suppressor of the epithelial–mesenchymal transition, clinical values of GRHL2 and its relationship with the metastasis-related factors, such as hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF), remain unclear. In order to investigate the expression of GRHL2, HIF-1α, and VEGF, and their correlation with angiogenesis in EC, 63 patients with EC were examined. The expression of GRHL2, HIF-1α, and VEGF in tumor tissues was higher than that in adjacent tissues and was associated with tumor differentiation. GRHL2 expression was significantly correlated with lymph node metastasis and invasion depth, whereas VEGF expression was associated with tumor (TNM) stage. A significant correlation was found between the expression of GRHL2 and HIF-1α. The patients expressing low GRHL2 and high HIF-1α showed significant reduction in both overall survival rate and disease-free survival rate. The results demonstrated that abnormal expression of GRHL2 is common in EC, and low expression of GRHL2 accompanied by a high expression of HIF-1α indicates poor prognosis.

Predictive value for lymph node metastasis of epithelial-mesenchymal transition and cancer stem cell marker expression in early gastric cancer

BACKGROUND

Minimally invasive therapies, including endoscopic mucosal resection or sentinel node navigation surgery, have been widely applied in early gastric cancer because of their benefits in promoting patient quality of life. However, lymph node dissection is beyond the capability of endoscopic therapy, and in sentinel node navigation surgery, the potential for skip metastasis is not negligible. Therefore, the possibility of lymph node metastasis is the most important factor to consider when deciding whether to apply the minimally invasive therapies. In the present study, the significance of epithelial mesenchymal transition and stem cell marker expression in lymph node metastasis in early gastric cancer was investigated.

METHODS

We evaluated the significance of the expression of 5 epithelial mesenchymal transition-related markers (E-cadherin, MMP7, S100A, Snail-1, and HGF) and 6 stem cell markers (ALDH1, SOX2, CD24, CD44, CD54, and CD133) in 119 early gastric cancer specimens using immunohistochemistry. Because protein expression is heterogeneous in gastric cancer, we analyzed the expression of these markers in two selected regions (one each at the superficial zone and the deep invasive front).

RESULTS

Expression of E-cadherin, MMP7, HGF, and CD133 at the deep invasive front was associated with the absence of lymph node metastasis (P=0.013, 0.018, <0.001, and 0.026, respectively). Presence of diffuse-type component, lymphatic invasion, and lack of expression of HGF and CD133 at the deep invasive front were independent predictive markers of lymph node metastasis (P=0.019, <0.001, 0.015, and 0.047, respectively).

CONCLUSIONS

Lymph node metastasis is strongly associated with expression status of HGF and CD133 at the deep invasive front, suggesting the usefulness of these proteins as independent predictive markers of lymph node metastasis in early gastric cancer.

Expression status of CD44 and CD133 as a prognostic marker in esophageal squamous cell carcinoma treated with neoadjuvant chemotherapy followed by radical esophagectomy

Cancer stem cells (CSCs) have self-renewal and pluripotency capabilities and contribute to cancer progression and chemoresistance. It has been proposed that the treatment resistance and heterogeneity of CSCs are deeply involved in the prognosis of patients with esophageal squamous cell carcinoma (ESCC). The objective of this study was to identify the influence of the expression status of the CSC markers CD44 and CD133 on chemotherapeutic efficacy and prognosis in ESCC patients who underwent radical esophagectomy after neoadjuvant chemotherapy (NAC). Endoscopically biopsied specimens taken before NAC and surgically resected specimens after NAC were immunohistochemically assessed for CD44 and CD133 expression for 47 ESCC patients who underwent NAC followed by radical esophagectomy. The correlation between CD44 and CD133 expression status and clinicopathological findings and the prognosis of ESCC patients after NAC followed by esophagectomy were analyzed. The percentages of CD44-positive cells and CD133-positive cells in specimens were increased after NAC. CD44 and CD133 expression status before NAC did not correlate with the degree of tumor progression and had no impact on the chemotherapeutic effect. However, strong expression of CD44 or CD133 and a high proportion of CD133-expressing cells before NAC were significantly associated with poorer esophageal cancer-specific survival. Patients with strong expression of CD44 or CD133 and those with a high ratio of CD133-positive tumor cells showed significantly poor prognosis regardless of the effect of chemotherapy. Multivariate analysis showed that simultaneous strong expression of CD44 and CD133 before NAC, a high rate of CD133-positive tumor cells before NAC, and primary tumor remission assessed by preoperative endoscopy were significant independent prognostic factors for ESCC. Our data indicate that CD44 and CD133 expression status prior to treatment dictates the malignant potential of ESCC and may be a novel predictor of recurrence and prognosis of ESCC patients after treatment.

CD133 initiates tumors, induces epithelial-mesenchymal transition and increases metastasis in pancreatic cancer

CD133 has been implicated as a cancer stem cell (CSC) surface marker in several malignancies including pancreatic cancer. However, the functional role of this surface glycoprotein in the cancer stem cell remains elusive. In this study, we determined that CD133 overexpression induced “stemness” properties in MIA-PaCa2 cells along with increased tumorigenicity, tumor progression, and metastasis in vivo. Additionally, CD133 expression induced epithelial-mesenchymal transition (EMT) and increased in vitro invasion. EMT induction and increased invasiveness were mediated by NF-κB activation, as inhibition of NF-κB mitigated these effects. This study showed that CD133 expression contributes to pancreatic cancer “stemness,” tumorigenicity, EMT induction, invasion, and metastasis.

Esophageal cancer stem cells and implications for future therapeutics

Esophageal carcinoma (EC) is a lethal disease with high morbidity and mortality worldwide, and the incidence has been increasing in recent years. Although the diagnosis and treatment of EC have improved considerably, EC has rapidly progressed in the clinical setting and has a poor prognosis for its metastasis and recurrence. The general idea of cancer stem cells (CSCs) is primarily based on clinical and experimental observations, indicating the existence of a subpopulation of cells that can self-renew and differentiate. The EC stem cells, which can be isolated from normal pluripotent stem cells by applying similar biomarkers, may participate in promoting esophageal tumorigenesis through renewal and repair. In this review, major emphasis is given to CSC markers, altered CSC-specific pathways, and molecular targeting agents currently available to target CSCs of esophageal cancer. The roles of numerous markers (CD44, aldehyde dehydrogenase, CD133, and ATP-binding cassette subfamily G member 2) and developmental signaling pathways (Wnt/β-catenin, Notch, hedgehog, and Hippo) in isolating esophageal CSCs are discussed in detail. Targeting CSCs can be a logical strategy to treat EC, as these cells are responsible for carcinoma recurrence and chemoradiation resistance.

Prognostic significance of overexpressed p16(INK4A) in esophageal squamous cell carcinoma: a meta-analysis

BACKGROUND

The prognostic value of p16(INK4A) in esophageal squamous cell carcinoma (ESCC) has been evaluated for several years although the results remain controversial.

MATERIALS AND METHODS

Various databases were systematically searched to identify studies published on the p16(INK4A) survival rate of ESCC patients. The pooled risk ratios and odds ratios with their corresponding 95% CIs were used to estimate the effect sizes.

RESULTS

A total of 16 studies comprising 1314 patients were included. p16(INK4A) overexpression was significantly associated with improved 5-year overall survival, disease-free survival, early tumor TNM stages, better tumor histological grade, no lymph node metastasis and more shallow tumor invasive depth (p < 0.05).

CONCLUSION

p16(INK4A) expression could be a useful biomarker to predict better prognosis for ESCC patients.

DNA Damage in CD133-Positive Cells in Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus (BE) caused by gastroesophageal reflux is a major risk factor of Barrett's esophageal adenocarcinoma (BEA), an inflammation-related cancer. Chronic inflammation and following tissue damage may activate progenitor cells under reactive oxygen/nitrogen species-rich environment. We previously reported the formation of oxidative/nitrative stress-mediated mutagenic DNA lesions, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-nitroguanine, in columnar epithelial cells of BE tissues and cancer cells of BEA tissues. We investigated the mechanisms of BEA development in relation to oxidative/nitrative DNA damage and stem cell hypothesis. We examined 8-nitroguanine and 8-oxodG formation and the expression of stem cell marker (CD133) in biopsy specimens of patients with BE and BEA by immunohistochemical analysis in comparison with those of normal subjects. CD133 was detected at apical surface of columnar epithelial cells of BE and BEA tissues, and the cytoplasm and cell membrane of cancer cells in BEA tissues. DNA lesions and CD133 were colocalized in columnar epithelial cells and cancer cells. Their relative staining intensities in these tissues were significantly higher than those in normal subjects. Our results suggest that BE columnar epithelial cells with CD133 expression in apical surface undergo inflammation-mediated DNA damage, and mutated cells acquire the property of cancer stem cells with cytoplasmic CD133 expression.

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.

Prognostic value of cancer stem cell marker CD133 expression in esophageal carcinoma: A meta-analysis

CD133 has been identified as a putative neoplastic stem cell marker in esophageal carcinoma. However, the prognostic value of CD133 overexpression in patients with esophageal carcinoma remains controversial. A meta-analysis of previous studies was performed, in order to assess the association of CD133 overexpression with the clinicopathological characteristics of esophageal carcinoma patients. A total of 7 studies, including 538 patients, were subjected to the final analysis. Our results indicated that a positive CD133 expression was significantly associated with lymph node metastasis [odds ratio (OR)=3.09, 95% confidence interval (CI): 1.93-4.95; P<0.00001], clinical stage (OR=4.26, 95% CI: 1.55-11.73; P=0.005) and histopathological grade (OR=2.40, 95% CI: 1.16-4.94; P=0.02). There was no statistically significant association of CD133 with depth of invasion (OR=1.89, 95% CI: 0.42-8.43; P=0.41). Based on the results of this study, we concluded that CD133 is an efficient prognostic factor in esophageal carcinoma. Higher CD133 expression is significantly associated with lymph node metastasis, clinical stage and histopathological grade.

Expression of CD44 and CD29 by PEComa cells suggests their possible origin of mesenchymal stem cells

BACKGROUND

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. The perivascular epithelioid cell (PEC) co-expresses melanocytic and muscle markers. Since no normal counterpart to the PEC has ever been identified in any normal tissue, the cell origin of these tumors is still uncertain. Although, several hypotheses have recently been advanced to explain the histogenesis of PEComa, it remains unclear.

METHODS

The aim of this study was to discuss whether differential expression of stem cell-associated proteins could be used to aid in determining the histogenesis of PEComa. For this purpose, we detected the immunoexpression of 5 kinds of stem cell markers on PEComas, including CD29, CD44, CD133, ALDH1, and nestin. In addition to observed histopathologic morphology, we also performed PEComa relevant clinical diagnostic markers (HMB-45, SMA, melan-A, Desmin, Ki-67, S-100 and TFE3) to identify whether they belonged to PEComas.

RESULTS

Our study included 13 PEComa samples, and we obtained positive immunoexpression results as follows: CD29 (13/13), CD44 (8/13), ALDH1 (10/13), nestin (1/13), and CD133 (0/13).

CONCLUSIONS

Since CD44 and CD29 are surface proteins associated with MSCs, these results suggest that PEComa might arise from MSCs. However, whether MSCs are the origin of PEComa needs to be further explored in the future.

Analysis of indoleamine 2-3 dioxygenase (IDO) and EGFR co-expression in breast cancer tissue by immunohistochemistry

BACKGROUND

To determine the amount of co-expression of IDO and EGFR in breast cancer patients.

MATERIALS AND METHODS

In order to obtain the distribution of co-expression of IDO and EGFR in breast cancer, we tested 110 breast cancer paraffin tissue blocks with immunohistochemical methods. Then we investigated the relationship between the diagnostic and pathologic characteristics (tumor size, lymph node status, histologic grade, the gene expression of ER, PR, HER2, p53, Ki67 and PCNA) with the situation of co-expression of IDO and EGFR by reviewing the medical records of 32 breast cancer patients.

RESULTS

Among 110 breast cancers, 32 cases demonstrated IDO and EGFR co-expression (29.1%), IDO and EGFR synchronous co-expression being found in 19.1% and asynchronous in 10.0%.

CONCLUSIONS

IDO and EGFR were co-expressed in breast cancer, including synchronous and asynchronous co-expression. The results suggest that considering IDO and EGFR as two indicators for breast cancer treatment or prognosis analysis provides a potential option of individual treatment for the portion of breast cancer patients with co-expression of IDO and EGFR.

Cancer stem cells in oesophageal squamous cell carcinoma: Identification, prognostic and treatment perspectives

Cancer stem cells (CSCs) are a vital subpopulation of cells to target for the treatment of cancers. In oesophageal squamous cell carcinoma (ESCC), there are several markers such as CD44, ALDH, Pygo2, MAML1, Twist1, Musashi1, Side population (SP), CD271 and CD90 that have been proposed to identify the cancer stem cells in individual cancer masses. It has also been demonstrated that stem cell markers like ALDH1, HIWI, Oct3/4, ABCG2, SOX2, SALL4, BMI-1, NANOG, CD133 and podoplanin are associated with patient's prognosis, pathological stages, cancer recurrence and therapy resistance. Finding new cancer stem cell targets or designing drugs to manipulate the known molecular targets in CSCs could be useful for improvements in clinical outcomes of the disease. To conclude, data suggest that CSCs in oesophageal squamous cell carcinoma are related to resistance to therapy and poor prognosis of patients with ESCC. Therefore, innovative insights into CSC biology and CSC-targeted therapies will help to achieve more effective management of patients with oesophageal squamous cell carcinoma.

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.

p53 is an independent prognostic factor in operable esophageal squamous cell carcinoma: a large-scale study with a long follow-up

The p53 protein is involved in many biological functions in cancer, such as cell cycle arrest, DNA repair, apoptosis, senescence, DNA metabolism, angiogenesis, and cellular differentiation. However, the association between p53 expression and clinicopathological findings or prognosis in esophageal squamous cell carcinoma (ESCC) is controversial. We designed a large-scale study of 830 operable ESCC patients with a long follow-up to investigate the relationship between p53 expression and the clinicopathological characteristics and prognosis of patients. Immunohistochemistry was used to detect p53 protein expression. When the patients were divided into two groups, a positive expression group and a negative expression group, p53-positive expression positively correlated with a poorer differentiation level (P = 0.044). The overexpression of p53 was associated with a more advanced clinical stage (P = 0.015). A total of 775 patients were available for survival analysis. The median OS of 160 patients who had p53-positive expression and 486 patients who had p53-negative expression were 58.8 and 46.3 months, respectively (P = 0.021); the median PFS of the two groups were 39.6 and 27.5 months, respectively (P = 0.015). Lymph node metastasis, gender, differentiation, depth of invasion, and p53 protein expression were proven to have an influence on both OS and PFS in a univariate analysis. In the multivariate analysis, p53-positive expression maintained its independent prognostic impact on OS (P = 0.048) and PFS (P = 0.039), as did lymph node metastasis, differentiation, and depth of invasion. We identified that p53 protein-positive expression can serve as an independent, unfavorable prognosis biomarker in ESCC.

Inhibition of human esophageal squamous cell carcinomas by targeted silencing of tumor enhancer genes: an overview

Esophageal cancer has been reported as the ninth most common malignancy and ranks as the sixth most frequent cause of death worldwide. Esophageal cancer treatment involves surgery, chemotherapy, radiation therapy, or combination therapy. Novel strategies are needed to boost the oncologic outcome. Recent advances in the molecular biology of esophageal cancer have documented the role of genetic alterations in tumorigenesis. Oncogenes serve a pivotal function in tumorigenesis. Targeted therapies are directed at the unique molecular signature of cancer cells for enhanced efficacy with low toxicity. RNA interference (RNAi) technology is a powerful tool for silencing endogenous or exogenous genes in mammalian cells. Related results have shown that targeting oncogenes with siRNAs, specifically the mRNA, effectively reduces tumor cell proliferation and induces apoptotic cell death. This article will briefly review studies on silencing tumor enhancer genes related to the induction of esophageal cancer.

p53 immunohistochemical expression and patient prognosis in esophageal squamous cell carcinoma

It is generally accepted that overexpression of p53 protein is associated with poor prognosis in gastric, lung, and other types of cancer. However, the prognostic significance of p53 aberrations in esophageal cancer remains unclear. This is the largest study (n = 266) examining clinical and prognostic features of p53 immunohistochemical expression in esophageal squamous cell carcinoma. In 139 (52%) esophageal tumors, nuclear immunoreactivity for p53 protein was detected. p53 aberrant expression was not associated with sex, age, preoperative treatment, TNM stage, or histological grade. Furthermore, p53 expression did not correlate with disease-free survival (P = 0.73) or overall survival (P = 0.62). In addition, no significant modification effect by any of the covariates in the survival analysis was observed (all P > 0.15). In conclusion, our large-scale study demonstrates that p53 expression has no impact on the prognosis of esophageal squamous cell carcinoma.