Is CD133 expression a prognostic biomarker of non-small-cell lung cancer? A systematic review and meta-analysis

PROM2 upregulation promotes cancer cell migration and confers a poor prognosis in lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) remains a difficult-to-treat disease with a poor prognosis. While prominin-1 (PROM1/CD-133) is largely investigated in a variety of malignancies, the role of prominin-2 (PROM2), the other member of the prominin family, has not been studied in LUSC. Transcriptomic data derived from matched tumor and adjacent non-tumorous lung tissues of LUSC patients were employed to conduct an in-depth analysis of the genetic and epigenetic regulation of prominin genes within LUSC, utilizing bioinformatic approaches. Furthermore, cellular behavior experiments were executed to discern the biological functions of PROM2. It was observed that PROM2, in contrast to PROM1, exhibited significant upregulation and overexpression at both the mRNA and protein levels in LUSC, and this upregulation was correlated with shortened patient survival. Transcriptomic analysis unveiled DNA methylation as an epigenetic regulatory mechanism associated with PROM2 expression. Notably, two transcription factors, CBFB and NRIP1, were identified as potential regulators of PROM2 expression. Subsequent in vitro investigations demonstrated that knocking down PROM2 led to the inhibition of cancer cell migration and the epithelial-to-mesenchymal transition (EMT). In summary, the pronounced upregulation of PROM2 in LUSC patients was linked to an unfavorable prognosis, possibly attributable to its influence on cancer cell migration and EMT. These findings suggest that PROM2 could serve as a promising diagnostic biomarker and therapeutic target in the management of LUSC. Consequently, further research into the mechanistic aspects and potential therapeutic interventions targeting PROM2 is warranted in the clinical context.

Heterogeneity of cancer stem cell-related marker expression is associated with three-dimensional structures in malignant pleural effusion produced by lung adenocarcinoma

INTRODUCTION

Cancer stem cells have been described in lung adenocarcinoma-associated malignant pleural effusion. They show clinically important features, including the ability to initiate new tumours and resistance to treatments. However, their correlation with the three-dimensional tumour structures in the effusion is not well understood.

METHODS

Cell blocks produced from lung adenocarcinoma patients' pleural effusion were examined for cancer stem cell-related markers Nanog and CD133 using immunocytochemistry. The three-dimensional cancer cell structures and CD133 expression patterns were visualized with tissue-clearing technology. The expression patterns were correlated with tumour cell structures, genetic variants and clinical outcomes.

RESULTS

Thirty-nine patients were analysed. Moderate-to-strong Nanog expression was detected in 27 cases (69%), while CD133 was expressed by more than 1% of cancer cells in 11 cases (28%). Nanog expression was more homogenous within individual specimens, while CD133 expression was detected in single tumour cells or cells within small clusters instead of larger structures in 8 of the 11 positive cases (73%). Although no statistically significant correlation between the markers and tumour genetic variants or patient survival was observed, we recorded seven cases with follow-up specimens after cancer treatment, and four (57%) showed a change in stem cell-related marker expression corresponding to treatment response.

CONCLUSIONS

Lung adenocarcinoma cells in the pleural effusion show variable expression of cancer stem cell-related markers, some showing a correlation with the size of cell clusters. Their expression level is potentially correlated with cancer treatment effects.

Can CD133 Be Regarded as a Prognostic Biomarker in Oncology: Pros and Cons

The CD133 cell membrane glycoprotein, also termed prominin-1, is expressed on some of the tumor cells of both solid and blood malignancies. The CD133-positive tumor cells were shown to exhibit higher proliferative activity, greater chemo- and radioresistance, and enhanced tumorigenicity compared to their CD133-negative counterparts. For this reason, CD133 is regarded as a potential prognostic biomarker in oncology. The CD133-positive cells are related to the cancer stem cell subpopulation in many types of cancer. Recent studies demonstrated the involvement of CD133 in the regulation of proliferation, autophagy, and apoptosis in cancer cells. There is also evidence of its participation in the epithelial-mesenchymal transition associated with tumor progression. For a number of malignant tumor types, high CD133 expression is associated with poor prognosis, and the prognostic significance of CD133 has been confirmed in a number of meta-analyses. However, some published papers suggest that CD133 has no prognostic significance or even demonstrate a certain correlation between high CD133 levels and a positive prognosis. This review summarizes and discusses the existing evidence for and against the prognostic significance of CD133 in cancer. We also consider possible reasons for conflicting findings from the studies of the clinical significance of CD133.

An Analysis of JADE2 in Non-Small Cell Lung Cancer (NSCLC)

The JADE family comprises three members encoded by individual genes and roles for these proteins have been identified in chromatin remodeling, cell cycle progression, cell regeneration and the DNA damage response. JADE family members, and in particular JADE2 have not been studied in any great detail in cancer. Using a series of standard biological and bioinformatics approaches we investigated JADE2 expression in surgically resected non-small cell lung cancer (NSCLC) for both mRNA and protein to examine for correlations between JADE2 expression and overall survival. Additional correlations were identified using bioinformatic analyses on multiple online datasets. Our analysis demonstrates that JADE2 expression is significantly altered in NSCLC. High expression of JADE2 is associated with a better 5-year overall survival. Links between JADE2 mRNA expression and a number of mutated genes were identified, and associations between JADE2 expression and tumor mutational burden and immune cell infiltration were explored. Potential new drugs that can target JADE2 were identified. The results of this biomarker-driven study suggest that JADE2 may have potential clinical utility in the diagnosis, prognosis and stratification of patients into various therapeutically targetable options.

Clinical relevance of stem cells in lung cancer

Lung cancer is the major cause of cancer-related deaths worldwide, it has one of the lowest 5-year survival rate, mainly because it is diagnosed in the late stage of the disease. Lung cancer is classified into two groups, small cell lung cancer (SCLC) and non-SCLC (NSCLC). In turn, NSCLC is categorized into three distinct cell subtypes: Adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. NSCLC is the most common lung cancer, accounting for 85% of all lung cancers. Treatment for lung cancer is linked to the cell type and stage of the disease, involving chemotherapy, radiation therapy, and surgery. Despite improvements in therapeutic treatments, lung cancer patients show high rates of recurrence, metastasis, and resistance to chemotherapy. Lung stem cells (SCs) are undifferentiated cells capable of self-renewal and proliferation, are resistant to chemotherapy and radiotherapy and, due to their properties, could be involved in the development and progression of lung cancer. The presence of SCs in the lung tissue could be the reason why lung cancer is difficult to treat. The identification of lung cancer stem cells biomarkers is of interest for precision medicine using new therapeutic agents directed against these cell populations. In this review, we present the current knowledge on lung SCs and discuss their functional role in the initiation and progression of lung cancer, as well as their role in tumor resistance to chemotherapy.

Multicellular Effects of STAT3 in Non-small Cell Lung Cancer: Mechanistic Insights and Therapeutic Opportunities

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and accounts for 85% of lung cancer cases. Aberrant activation of the Signal Transducer and Activator of Transcription 3 (STAT3) is frequently observed in NSCLC and is associated with a poor prognosis. Pre-clinical studies have revealed an unequivocal role for tumor cell-intrinsic and extrinsic STAT3 signaling in NSCLC by promoting angiogenesis, cell survival, cancer cell stemness, drug resistance, and evasion of anti-tumor immunity. Several STAT3-targeting strategies have also been investigated in pre-clinical models, and include preventing upstream receptor/ligand interactions, promoting the degradation of STAT3 mRNA, and interfering with STAT3 DNA binding. In this review, we discuss the molecular and immunological mechanisms by which persistent STAT3 activation promotes NSCLC development, and the utility of STAT3 as a prognostic and predictive biomarker in NSCLC. We also provide a comprehensive update of STAT3-targeting therapies that are currently undergoing clinical evaluation, and discuss the challenges associated with these treatment modalities in human patients.

LncRNA DUXAP10 Upregulation and the Hedgehog Pathway Activation Are Critically Involved in Chronic Cadmium Exposure-Induced Cancer Stem Cell-Like Property

Cadmium (Cd) is a well-known lung carcinogen. However, the mechanism of Cd carcinogenesis remains to be clearly defined. Cd has been shown to act as a weak mutagen, suggesting that it may exert tumorigenic effect through nongenotoxic ways, such as epigenetic mechanisms. Long noncoding RNAs (lncRNAs) refer to RNA molecules that are longer than 200 nucleotides in length but lack protein-coding capacities. Regulation of gene expressions by lncRNAs is considered as one of important epigenetic mechanisms. The goal of this study is to investigate the mechanism of Cd carcinogenesis focusing on the role of lncRNA dysregulations. Cd-induced malignant transformation of human bronchial epithelia BEAS-2B cells was accomplished by a 9-month low-dose Cd (CdCl2, 2.5 µM) exposure. The Cd-exposed cells formed significantly more colonies in soft agar, displayed cancer stem cell (CSC)-like property, and formed tumors in nude mice. Mechanistically, chronic low-dose Cd exposure did not cause significant genotoxic effects but dysregulated lncRNA expressions. Further Q-PCR analysis confirmed the significant upregulation of the oncogenic lncRNA DUXAP10 in Cd-transformed cells. DUXAP10 knockdown in Cd-transformed cells significantly reduced their CSC-like property. Further mechanistic studies showed that the Hedgehog pathway is activated in Cd-transformed cells and inhibition of this pathway reduces Cd-induced CSC-like property. DUXAP10 knockdown caused the Hedgehog pathway inactivation in Cd-transformed cells. Furthermore, Pax6 expression was upregulated in Cd-transformed cells and Pax6 knockdown significantly reduced their DUXAP10 levels and CSC-like property. In summary, these findings suggest that the lncRNA DUXAP10 upregulation may play an important role in Cd carcinogenesis.

Jorunnamycin A Suppresses Stem-Like Phenotypes and Sensitizes Cisplatin-Induced Apoptosis in Cancer Stem-Like Cell-Enriched Spheroids of Human Lung Cancer Cells

It has been recognized that cancer stem-like cells (CSCs) in tumor tissue crucially contribute to therapeutic failure, resulting in a high mortality rate in lung cancer patients. Due to their stem-like features of self-renewal and tumor formation, CSCs can lead to drug resistance and tumor recurrence. Herein, the suppressive effect of jorunnamycin A, a bistetrahydroisoquinolinequinone isolated from Thai blue sponge Xestospongia sp., on cancer spheroid initiation and self-renewal in the CSCs of human lung cancer cells is revealed. The depletion of stemness transcription factors, including Nanog, Oct-4, and Sox2 in the lung CSC-enriched population treated with jorunnamycin A (0.5 μM), resulted from the activation of GSK-3β and the consequent downregulation of β-catenin. Interestingly, pretreatment with jorunnamycin A at 0.5 μM for 24 h considerably sensitized lung CSCs to cisplatin-induced apoptosis, as evidenced by upregulated p53 and decreased Bcl-2 in jorunnamycin A-pretreated CSC-enriched spheroids. Moreover, the combination treatment of jorunnamycin A (0.5 μM) and cisplatin (25 μM) also diminished CD133-overexpresssing cells presented in CSC-enriched spheroids. Thus, evidence on the regulatory functions of jorunnamycin A may facilitate the development of this marine-derived compound as a novel chemotherapy agent that targets CSCs in lung cancer treatment.

Prospects for Using Expression Patterns of Paramyxovirus Receptors as Biomarkers for Oncolytic Virotherapy

Simple Summary

Some non-pathogenic viruses that do not cause serious illness in humans can efficiently target and kill cancer cells and may be considered candidates for cancer treatment with virotherapy. However, many cancer cells are protected from viruses. An important goal of personalized cancer treatment is to identify viruses that can kill a certain type of cancer cells. To this end, researchers investigate expression patterns of cell entry receptors, which viruses use to bind to and enter host cells. We summarized and analyzed the receptor expression patterns of two paramyxoviruses: The non-pathogenic measles and the Sendai viruses. The receptors for these viruses are different and can be proteins or lipids with attached carbohydrates. This review discusses the prospects for using these paramyxovirus receptors as biomarkers for successful personalized virotherapy for certain types of cancer.

Abstract

The effectiveness of oncolytic virotherapy in cancer treatment depends on several factors, including successful virus delivery to the tumor, ability of the virus to enter the target malignant cell, virus replication, and the release of progeny virions from infected cells. The multi-stage process is influenced by the efficiency with which the virus enters host cells via specific receptors. This review describes natural and artificial receptors for two oncolytic paramyxoviruses, nonpathogenic measles, and Sendai viruses. Cell entry receptors are proteins for measles virus (MV) and sialylated glycans (sialylated glycoproteins or glycolipids/gangliosides) for Sendai virus (SeV). Accumulated published data reviewed here show different levels of expression of cell surface receptors for both viruses in different malignancies. Patients whose tumor cells have low or no expression of receptors for a specific oncolytic virus cannot be successfully treated with the virus. Recent published studies have revealed that an expression signature for immune genes is another important factor that determines the vulnerability of tumor cells to viral infection. In the future, a combination of expression signatures of immune and receptor genes could be used to find a set of oncolytic viruses that are more effective for specific malignancies.

SNP rs2240688 in CD133 gene on susceptibility and clinicopathological features of hepatocellular carcinoma

Background

CD133 is one of the important cancer stem cells (CSCs) markers of hepatocellular carcinoma (HCC). The aim of this study was to explore the relationship between CD133 single-nucleotide polymorphisms (SNPs) and risk factors associated with HCC susceptibility and clinicopathological features in HCC cases and healthy controls from the Guangxi region of southern China.

Methods

A case control study was conducted, including 565 HCC patients and 561 control subjects. The genotyping of rs2240688 was performed using the SNaPshot method. Unconditional logistic regression was used to correct for gender, age, and other confounding factors. Odds ratio (OR) and its 95% confidence interval (CI) were calculated to analyze the relationship between allele and genotype frequency and the risk of HCC.

Results

The distribution frequencies of CD133 alleles and genotypes in the HCC case group and the control group were statistically significant (P<0.05). The CA heterozygous (P=0.003, OR =1.463, 95% CI: 1.134–1.887) and CC homozygous genotypes (P=0.036, OR =1.910, 95% CI: 1.044–3.493), as well as C carrier status (P=0.004, OR =1.465, 95% CI: 1.136–1.889) and C alleles (P=0.004, OR =1.465, 95% CI: 1.136–1.889), were associated with an increased risk of HCC. Additionally, in the subgroup analysis of CD133 rs2240688 polymorphism and clinical characteristics, the results showed that the genotype distribution of CD133 rs2240688 was significantly different in genotype distribution of metastasis and alanine aminotransferase (ALT).

Conclusions

the expression of miRNA binding site rs2240688 of tumor stem cell marker gene CD133 in HCC may be a promising marker for the prediction of HCC, but larger studies are still needed.

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.

CD133 as a regulator of cancer metastasis through the cancer stem cells

Cancer stem cells are the cancer cells that have abilities to self-renew, differentiate into defined progenies, and initiate and maintain tumor growth. They also contribute to cancer metastasis and therapeutic resistance, both of which are the major causes of cancer mortality. Among the reported makers of the cancer stem cells, CD133 is the most well-known marker for isolating and studying cancer stem cells in different types of cancer. The CD133^high population of cancer cells are not only capable of self-renewal, proliferation, but also highly metastatic and resistant to therapy. Despite very limited information on physiological functions of CD133, many ongoing studies are aimed to reveal the mechanisms that CD133 utilizes to modulate cancer dissemination and drug resistance with a long-term goal for bringing down the number of cancer deaths. In this review, in addition to the regulation of CD133, and its involvement in cancer initiation, and development, the recent updates on how CD133 modulates cancer dissemination, and therapeutic resistance are provided. The key signaling pathways that are upstream or downstream of CD133 during these processes are summarized. A comprehensive understanding of CD133-mediated cancer initiation, development, and dissemination through its pivotal role in cancer stem cells will offer new strategies in cancer therapy.

CD133 Expression as a Helicobacter pylori-independent Biomarker of Gastric Cancer Progression

BACKGROUND/AIM

Gastric adenocarcinoma is the fourth most common cancer worldwide. While gastric cancer prevalence varies globally and incidence rates are decreasing in the West, many cases continue to be diagnosed at an advanced stage and the 5-year survival rate still falls below 30%. Early treatment of gastric cancer by endoscopic and/or surgical therapy may decrease mortality; yet reliable, universally applicable biomarkers for early detection of gastric cancer have still not been established.

MATERIALS AND METHODS

The present work compares the expression of CD133 (prominin-1), a potential biomarker of disease progression in gastric cancer, between independent cohorts of H. pylori (+) and H. pylori (-) patients at each respective stage of carcinogenesis. H. pylori (-) patients (N=45) who underwent gastric biopsy at the Moffitt Cancer Center (MCC) in Tampa, Florida, and H. pylori (+) patients (N=59) who underwent gastric biopsy at the Instituto de Patologia Mejia Jimenez (IPMJ) in Cali, Colombia were evaluated and immunostained for CD133.

RESULTS

A statistically significant increase in CD133 expression (in terms of the Allred score) was observed between all stages of progression (normal mucosa, inflammation/metaplasia, low-grade dysplasia and gastric adenocarcinoma) for each respective patient cohort. No statistically significant difference in CD133 expression at each respective stage of disease was observed between the H. pylori-positive and negative-cohorts.

CONCLUSION

The observation of distinct stepwise increases in CD133 expression in both patient cohorts, and the lack of any significant difference between groups, suggests that CD133 expression may serve as a biomarker for early detection of gastric cancer independent of bacterial status and strain, and corresponding differences in disease histomorphology and classification. This warrants further validation on larger independent cohorts across multiple geographic regions and incorporating multiple bacterial strain types.

The prognostic value of CSCs biomarker CD133 in NSCLC: a meta-analysis

The prognostic value of cancer stem cells (CSCs) marker CD133 in non-small-cell lung cancer (NSCLC) remains controversial. We performed this meta-analysis of 32 eligible studies to clarify the prognostic value of CD133 and provide evidence for CSCs hypothesis. We calculated pooled hazard ratio (HR) for survival outcomes and pooled odds ratio (OR) for clinical parameters associated with CD133 in total 3595 NSCLC patients by STATA. Our results showed that NSCLC patients with higher CD133 expression had shorter overall survival time only in Asian patients (HR = 3.80, 95% CI: 3.12-4.04, p < 0.001; I2 = 32%) but not in Caucasian patients (HR = 1.15, 95% CI: 0.88-1.52, p = 0.307; I2 = 0%), suggesting that differential prognostic value of CD133 in distinct ethnic group. We speculated that the intrinsic EGFR gene status of CSCs might be responsible for this racial difference. Additionally, we found that higher expression of CD133 was associated with poor differentiation (OR = 2.03, 95% CI: 1.32-3.14, p = 0.001) and lymph node metastasis (OR = 2.39, 95% CI: 1.62-3.52, p < 0.001) but there was no significant difference of CD133 expression between adenocarcinoma and squamous carcinoma (OR = 1.13, 95% CI: 0.93-1.38, p = 0.3) in NSCLC patients. These results may provide a new therapeutic perspective on the treatment of NSCLC patients according to the expression of CD133 in distinct ethnic group.

Expression of ORAOV1, CD133 and WWOX correlate with metastasis and prognosis in gastric adenocarcinoma

BACKGROUND

Oral cancer overexpressed 1 (ORAOV1) which is a novel candidate oncogene is a useful biomarker of metastasis and prognosis in various cancers. CD133 which is a biomarker of cancer stem cells is overexpressed in many cancers and promotes cancer cells growth and metastasis. WW domain-containing oxidoreductase (WWOX) which is a suppressor gene of tumor can inhibit proliferation and promote apoptosis in various cancers. However, associations among ORAOV1, CD133, and WWOX and their clinicopathological significance in gastric adenocarcionma (GAC) are unclear. In this study, we analyzed associations among ORAOV1, CD133, and WWOX in GAC, and their respective associations with clinicopathological characteristics and survival in GAC.

METHOD

Positive expression of ORAOV1, CD133, and WWOX in 236 whole GAC tissue samples were detected by immunohistochemistry staining. Patients' clinical data were also collected.

RESULTS

Levels of ORAOV1 and CD133 were significantly higher, and levels of WWOX significantly lower, in GAC tissues than in normal gastric tissues. Levels of ORAOV1 and CD133 were positively associated with tumor grade, invasion of depth, lymph node metastasis (LNM), and tumor-node metastasis (TNM) stages, and inversely with patients overall survival time; levels of WWOX was negatively correlated with tumor grade, invasion of depth, LNM, and TNM stages, and the WWOX-positive subgroup had significantly longer overall survival time than did the WWOX-negative subgroup. In multivariate analysis, high expression of ORAOV1 and CD133, invasion of depth, and TNM stages, and low expression of WWOX were potential to be independent prognostic factors for overall survival time in patients with GAC.

CONCLUSIONS

The expression of ORAOV1, CD133, and WWOX represent promising biomarkers for metastasis and prognosis, and potential therapeutic targets for GAC.

CD133 in brain tumor: the prognostic factor

CD133 has been shown to be an important stem cell factor that promotes glioma progression. However, the mechanism for CD133-mediated glioma progression has yet to be fully elucidated. In this study, we found that CD133 mRNA expression was a prognostic marker in three independent glioma patient cohorts, corroborating a putative role for CD133 in glioma progression. Importantly, we found that CD133 expression in glioma was highly correlated with the expression of HOX gene stem cell factors (HOXA5, HOXA7, HOXA10, HOXC4 and HOXC6). The expression of these HOX genes individually was significantly associated with survival. Interestingly, the prognostic significance of CD133 was dependent on the expression level of HOX genes, and vice versa. CD133 (p = 0.021) and HOXA7 (p = 0.001) were independent prognostic markers when the three glioma patient cohorts were combined (n = 231). Our results suggest that HOX genes may play a more important role in progression of glioma when CD133 expression is low. Furthermore, we showed that low-level expression of LIM2 in CD133-high glioma was associated with poorer survival, suggesting that LIM2 could be a therapeutic target for glioma expressing a high level of CD133. Connectivity mapping identified vinblastine and vincristine as agents that could reverse the CD133/HOX genes/LIM2-signature, and we confirmed this by in vitro analysis in glioma cell lines, demonstrating that CD133 and HOX genes were co-expressed and could be downregulated by vincristine. In conclusion, our data show that CD133 and HOX genes are important prognostic markers in glioma and shed light on possible treatment strategies for glioma expressing a high level of CD133.

Prognostic value of number of negative lymph node in patients with stage II and IIIa non-small cell lung cancer

Background

The definitive validation evidence of the implications of lymph node metastases regarding the survival of Non-Small Cell Lung Cancer (NSCLC) patients is lacking. We aimed to evaluate the prognostic impact of several lymph node metastases-associated risk factors including Number of Negative Lymph Node (NLN) and risk-stratify NSCLC patients into subsets with different prognosis.

Method

A total of 482 patients with N1 and N2 NSCLC were included in this study. The prognostic importance of a set of risk factors was examined by univariate and multivariate analysis. The cut-off points and 5 years survival rates were calculated to test the best grouping system to stratify the patients with difference outcome.

Results

Our analysis indicated that both Ratio of the Metastatic Lymph nodes (RML) and Number of Negative Lymph Node (NLN) were associated with overall survival (OS) and disease free survival (DFS). RML percentage 20% and 55%, and NLN counts 10 and 30 were proved as the optimal cut-off points to predict OS by classifying patients into 3 groups, respectively. RML and NLN actually are more powerful in predicting survival outcome for male patients compared to female patients. Stratified survival analyses using combined factors indicated that the 5-year survival rate (5-YSR) is high in RML I + NLN I/III subgroup (5-YSR = 57.1% and 43.3%) and low in RML III + NLN II/III subgroup (5-YSR = 0.0 % each).

Conclusions

NLN is a strong prognostic factor for OS and DFS of stage II/IIIa NSCLC patients, and provides a useful classification scheme for NSCLC patients when combined with RML.

Immunohistochemical Markers as Predictors of Histopathologic Response and Prognosis in Rectal Cancer Treated with Preoperative Adjuvant Therapy: State of the Art

We explain the state of the art of the immunohistochemical markers of response in rectal cancers treated with neoadjuvant medical therapies and its implication with prognosis. Neoadjuvant chemoradiotherapy is widely used to improve the outcome of patients with locally advanced rectal cancer, and the evaluation of the effects of medical therapy is to date based on histomorphological examination by applying four grading systems of response to therapy (tumor regression grade (TRG)). The need to identify immunohistochemical markers that could ensure a better assessment of response and possibly provide additional prognostic information has emerged. We identified p53, p27kip1, Ki67, matrix metalloprotease-9, survivin, Ki67 proliferative index, CD133, COX2, CD44v6, thymidylate synthase, thymidine phosphorylase, and dihydropyrimidine dehydrogenase as the most common markers studied in literature to date, and we explained their prognostic potential and their implications in the evaluation of the response to preoperative therapies in rectal cancers.

[Molecular markers of cancer stem cells verified in vivo]

This systematic review aims to analyze molecular markers of cancer stem cells. Only studies that confirmed tumor-initiating capacity of this population by in vivo assay in immunodeficient mice were included. Final sample of papers that fully correspond with initial aim consists of 97 original studies. The results of their analysis reveal that markers commonly used for cancer stem cells deriving were as follows: CD133, СD44, ALDH, CD34, CD24 and EpCAM. The review also contains description of molecular features of some cancer stem cell markers, modern approaches to cancer treatment by targeting this population and brief assessment of cancer stem cell theory development.

Polycomb complex protein BMI-1 promotes invasion and metastasis of pancreatic cancer stem cells by activating PI3K/AKT signaling, an ex vivo, in vitro, and in vivo study

Cancer stem cell theory indicates cancer stem cells are the key to promote tumor invasion and metastasis. Studies showed that BMI-1 could promote self-renew, differentiation and tumor formation of CSCs and invasion/metastasis of human cancer. However, whether BMI-1 could regulate invasion and metastasis ability of CSCs is still unclear. In our study, we found that up-regulated expression of BMI-1 was associated with tumor invasion, metastasis and poor survival of pancreatic cancer patients. CD133+ cells were obtained by using magnetic cell sorting and identified of CSCs properties such as self-renew, multi-differentiation and tumor formation ability. Then, we found that BMI-1 expression was up-regulated in pancreatic cancer stem cells. Knockdown of BMI-1 expression attenuated invasion ability of pancreatic cancer stem cells in Transwell system and liver metastasis capacity in nude mice which were injected CSCs through the caudal vein. We are the first to reveal that BMI-1 could promote invasion and metastasis ability of pancreatic cancer stem cells. Finally, we identified that BMI-1 expression activating PI3K/AKT singing pathway by negative regulating PTEN was the main mechanism of promoting invasion and metastasis ability of pancreatic CSCs. In summary, our findings indicate that BMI-1 could be used as the therapeutic target to inhibiting CSCs-mediated pancreatic cancer metastasis.

Activation of D2 Dopamine Receptors in CD133+ve Cancer Stem Cells in Non-small Cell Lung Carcinoma Inhibits Proliferation, Clonogenic Ability, and Invasiveness of These Cells

Lung carcinoma is the leading cause of cancer-related death worldwide, and among this cancer, non-small cell lung carcinoma (NSCLC) comprises the majority of cases. Furthermore, recurrence and metastasis of NSCLC correlate well with CD133+ve tumor cells, a small population of tumor cells that have been designated as cancer stem cells (CSC). We have demonstrated for the first time high expression of D₂ dopamine (DA) receptors in CD133+ve adenocarcinoma NSCLC cells. Also, activation of D₂ DA receptors in these cells significantly inhibited their proliferation, clonogenic ability, and invasiveness by suppressing extracellular signal-regulated kinases 1/2 (ERK1/2) and AKT, as well as down-regulation of octamer-binding transcription factor 4 (Oct-4) expression and matrix metalloproteinase-9 (MMP-9) secretion by these cells. These results are of significance as D₂ DA agonists that are already in clinical use for treatment of other diseases may be useful in combination with conventional chemotherapy and radiotherapy for better management of NSCLC patients by targeting both tumor cells and stem cell compartments in the tumor mass.

Expression of CD133 cancer stem cell marker in melanoma: a systematic review and meta-analysis

BACKGROUND

CD133-positive melanoma cells are thought to be melanoma-initiating cells with cancer stem cell (CSC) characteristics. Some researchers have reported that CD133-negative subsets can also initiate tumors, so the clinical significance of a CD133-positive subpopulation of cells in melanoma remains controversial. This systematic review was designed to assess the value of CD133 as a CSC marker in melanomas. A meta-analysis was also performed to cumulatively analyze the data on CD133 expression levels in the selected studies.

MATERIALS AND METHOD

Eligible studies were identified via an electronic search through various databases including PubMed, MEDLINE, Ovid MEDLINE, and Web of Science (from May 2005 through September 2014) using the following keywords: "CD133 or prominin-1", "cancer stem cells", and "melanoma". Only articles in which CD133 antigen was detected by immunohistochemistry (IHC) were included. A meta-analysis was performed to identify any association between CD133 expression and clinical outcomes.

RESULTS

Two hundred and ninety-nine melanoma cases from 5 studies were evaluated for expression levels of CD133 using IHC. Large heterogeneity was observed among the results (p&lt;0.001, I2 = 94%). Approximately 47.9% (95% CI 23.7%-72.1%) of the studied melanoma cases had high CD133 expression. The I2 value and Q-test p value for heterogeneity were 89.0% and &lt;0.001, respectively, and the pooled estimate of CD133 expression was 61.7% (95% CI 25.1%-98.4%).

CONCLUSIONS

Our findings suggest that CD133 is not yet proven to be an appropriate biomarker in identifying CSCs of melanoma. Thus, detection of CD133 in combination with other putative CSC markers may be more valuable for clinical application.

Galectin-1 is overexpressed in CD133+ human lung adenocarcinoma cells and promotes their growth and invasiveness

Previous studies demonstrated that a subpopulation of cancer cells, which are CD133 positive (CD133+) feature higher invasive and metastatic abilities, are called cancer stem cells (CSCs). By using tumor cells derived from patients with lung adenocarcinoma, we found that galectin-1 is highly overexpressed in the CD133+ cancer cells as compared to the normal cancer cells (CD133-) from the same patients. We overexpressed galectin-1 in CD133- cancer cells and downregulated it in CSCs. We found that overexpression of galectin-1 promoted invasiveness of CD133- cells, while knockdown of galectin-1 suppressed proliferation, colony formation and invasiveness of CSCs. Furthermore, tumor growth was significantly inhibited in CSCs xenografts with knockdown of galectin-1 as compared to CSCs treated with scramble siRNAs. Biochemical studies revealed that galectin-1 knockdown led to the suppression of COX-2/PGE2 and AKT/mTOR pathways, indicating galectin-1 might control the phenotypes of CSCs by regulating these signaling pathways. Finally, a retrospective study revealed that galectin-1 levels in blood circulation negatively correlates with overall survival and positively correlates with lymph node metastasis of the patients. Taken together, these findings suggested that galectin-1 plays a major role on the tumorigenesis and invasiveness of CD133+ cancer cells and might serve as a potential therapeutic target for treatment of human patients with lung adenocarcinoma.

Effect of CXCR4 and CD133 co-expression on the prognosis of patients with stage II~III colon cancer

BACKGROUND

To explore the relationship between CXCR4, CD133 co-expression and clinicopathological features as well as prognosis of patients with phase II~III colon cancer.

MATERIALS AND METHODS

Forty-nine paraffin-embedded samples of tumor tissue and epithelial tissue adjacent to cancer were collected from patients with colon cancer undergoing radical surgery in Baotou Cancer Hospital from January, 2010 to June, 2011. CXCR4 and CD133 expression was detected using immunohistochemistry and its relationship with clinicopathological features and the 3-year survival rate was analyzed.

RESULTS

In the tumor tissue and colonic epithelial tissue adjacent to cancer, the positive expression rates of CXCR4 were respectively 61.2% (30/49) and 8.16% (4/49), while those of CD133 being 36.7% (18/49) and 6.12% (3/49). CXCR4 and CD133 expression in tumor tissue was not related to patient age, gender, primary focal sites, tumor size, TNM staging, histological type, tumor infiltration depth and presence or absence of lymphatic metastasis, but CXCR4 and CD133 co-expression was associated with TNM staging and lymphatic metastasis. The 3-year survival rate of patients with CXCR4 and CD133 co-expression was 27.3% (3/11), and that of the remainderwas 76.3% (29/38), the difference being significant (χ2=7.0206, p=0.0081).

CONCLUSIONS

CXCR4 and CD133 co-expression may be a risk factor for poor prognosis of patients with stage II~III colon cancer.

Association between epithelial-mesenchymal transition and cancer stemness and their effect on the prognosis of lung adenocarcinoma

The epithelial-mesenchymal transition (EMT) and cancer stemness (CS) are reported to be pivotal phenomena involved in metastasis, recurrence, and drug-resistance in lung cancer; however, their effects on tumor malignancy in clinical settings are not completely understood. The mutual association between these factors also remains elusive and are worthy of investigation. The purpose of this study was to elucidate the association between EMT and CS, and their effect on the prognosis of patients with lung adenocarcinoma. A total of 239 lung adenocarcinoma specimens were collected from patients who had undergone surgery at Kyoto University Hospital from January 2001 to December 2007. Both EMT (E-cadherin,vimentin) and CS (CD133, CD44, aldehyde dehydrogenase) markers were analyzed through immunostaining of tumor specimens. The association between EMT and CS as well as the patients' clinical information was integrated and statistically analyzed. The molecular expression of E-cadherin, vimentin, and CD133 were significantly correlated with prognosis (P = 0.003, P = 0.005, and P < 0.001). A negative correlation was found between E-cadherin and vimentin expression (P < 0.001), whereas, a positive correlation was found between vimentin and CD133 expression (P = 0.020). CD133 was a stronger prognostic factor than an EMT marker. Elevated CD133 expression is the signature marker of EMT and CS association in lung adenocarcinoma. EMT and CS are associated in lung adenocarcinoma. Importantly, CD133 is suggested to be the key factor that links EMT and CS, thereby exacerbating tumor progression.

Prognostic value of cancer stem cell marker CD133 in ovarian cancer: a meta-analysis

OBJECTIVE

To investigate the association between CD133 expression and prognosis and clinicopathological features of ovarian cancer.

METHODS

The electronic and manual searches were performed through the database of PubMed Chinese Wanfang databases (up to September 15, 2014) was performed using the following keywords ovarian cancer, CD133, AC133, prominin-1. Meta-analysis was performed by using Review Manager 5.2 and the outcomes included the overall survival and various clinicopathological features.

RESULTS

A total of 1051 ovarian cancer patients from 8 studies were included. Meta-analysis showed that overexpression of CD133 was highly correlated with reduced 2-year overall survival (OR = 1.67, 95% CI: 1.06-2.63, P = 0.03, fixed-effect). With respect to clinicopathological features, CD133 level was positively correlated with tumor stage (OR = 0.26, 95% CI: 0.12-0.58, P = 0.001 random-effect). But not correlated with patients' age (OR = 1.12, 95% CI: 0.68-1.86, P = 0.65 fixed-effect), tumor grade (OR = 1.20, 95% CI: 0.06-1.62, P = 0.17 random-effect), histological type (OR = 1.10, 95% CI: 0.82-1.47, P = 0.54 fixed-effect) and response to treatment (OR = 0.84, 95% CI: 0.61-1.16, P = 0.29 fixed-effect).

CONCLUSION

On the basis of current retrospective evidence, the present meta-analysis indicated that high level of CD133 expression trends to correlate with a worse prognosis in patients with ovarian cancer.

Targeting lung cancer through inhibition of checkpoint kinases

Inhibitors of checkpoint kinases ATR, Chk1, and Wee1 are currently being tested in preclinical and clinical trials. Here, we review the basic principles behind the use of such inhibitors as anticancer agents, and particularly discuss their potential for treatment of lung cancer. As lung cancer is one of the most deadly cancers, new treatment strategies are highly needed. We discuss how checkpoint kinase inhibition in principle can lead to selective killing of lung cancer cells while sparing the surrounding normal tissues. Several features of lung cancer may potentially be exploited for targeting through inhibition of checkpoint kinases, including mutated p53, low ERCC1 levels, amplified Myc, tumor hypoxia and presence of lung cancer stem cells. Synergistic effects have also been reported between inhibitors of ATR/Chk1/Wee1 and conventional lung cancer treatments, such as gemcitabine, cisplatin, or radiation. Altogether, inhibitors of ATR, Chk1, and Wee1 are emerging as new cancer treatment agents, likely to be useful in lung cancer treatment. However, as lung tumors are very diverse, the inhibitors are unlikely to be effective in all patients, and more work is needed to determine how such inhibitors can be utilized in the most optimal ways.