IDENTIFICATION OF CD133+/NESTIN+ PUTATIVE CANCER STEM CELLS IN NON-SMALL CELL LUNG CANCER

Natural compounds as a potential modifier of stem cells renewal: Comparative analysis

Cancer stem cells (CSCs) are indispensable for development, progression, drug resistance, and tumor metastasis. Current cancer-directed interventions target targeting rapidly dividing cancer cells and slow dividing CSCs, which are the root cause of cancer origin and recurrence. The most promising targets include several self-renewal pathways involved in the maintenance and renewal of CSCs, such as the Wnt/β-Catenin, Sonic Hedgehog, Notch, Hippo, Autophagy, and Ferroptosis. In view of safety, natural compounds are coming to the front line of treatment modalities for modifying various signaling pathways simultaneously involved in maintaining CSCs. Therefore, targeting CSCs with natural compounds is a promising approach to treating various types of cancers. In view of this, here we provide a comprehensive update on the current status of natural compounds that effectively tune key self-renewal pathways of CSCs. In addition, we highlighted surface expression markers in several types of cancer. We also emphasize how natural compounds target these self-renewal pathways to reduce therapy resistance and cancer recurrence properties of CSCs, hence providing valuable cancer therapeutic strategies. The inclusion of nutraceuticals is believed to enhance the therapeutic efficacy of current cancer-directed interventions significantly.

Cancer stem cells and tumor heterogeneity: Deciphering the role in tumor progression and metastasis

Tumor heterogeneity, in principle, reflects the variation among different cancer cell populations. It can be termed inter- or intra-tumoral heterogeneity, respectively, based on its occurrence in various tissues from diverse patients or within a single tumor. The intra-tumoral heterogeneity is one of the leading causes of cancer progression and treatment failure, with the cancer stem cells (CSCs) contributing immensely to the same. These niche cells, similar to normal stem cells, possess the characteristics of self-renewal and differentiation into multiple cell types. Moreover, CSCs contribute to tumor growth and surveillance by promoting recurrence, metastasis, and therapeutic resistance. Diverse factors, including intracellular signalling pathways and tumor microenvironment (TME), play a vital role in regulating these CSCs. Although a panel of markers is considered to identify the CSC pool in various cancers, further research is needed to discriminate cancer-specific CSC markers in those. CSCs have also been found to be promising therapeutic targets for cancer therapy. Several small molecules, natural compounds, antibodies, chimeric antigen receptor T (CAR-T) cells, and CAR-natural killer (CAR-NK) cells have emerged as therapeutic tools for specific targeting of CSCs. Interestingly, many of these are in clinical trials too. Despite being a much-explored avenue of research for years, and we have come to understand its nitty-gritty, there is still a tremendous gap in our knowledge concerning its precise genesis and regulation. Hence, a concrete understanding is needed to assess the CSC-TME link and how to target different cancer-specific CSCs by designing newer tools. In this review, we have summarized CSC, its causative, different pathways and factors regulating its growth, association with tumor heterogeneity, and last but not least, discussed many of the promising CSC-targeted therapies for combating cancer metastasis.

Nestin-Expressing Cells in the Lung: The Bad and the Good Parts

Nestin is a member of the intermediate filament family, which is expressed in a variety of stem or progenitor cells as well as in several types of malignancies. Nestin might be involved in tissue homeostasis or repair, but its expression has also been associated with processes that lead to a poor prognosis in various types of cancer. In this article, we review the literature related to the effect of nestin expression in the lung. According to most of the reports in the literature, nestin expression in lung cancer leads to an aggressive phenotype and resistance to chemotherapy as well as radiation treatments due to the upregulation of phenomena such as cell proliferation, angiogenesis, and metastasis. Furthermore, nestin may be involved in the pathogenesis of some non-cancer-related lung diseases. On the other hand, evidence also indicates that nestin-positive cells may have a role in lung homeostasis and be capable of generating various types of lung tissues. More research is necessary to establish the true value of nestin expression as a prognostic factor and therapeutic target in lung cancer in addition to its usefulness in therapeutic approaches for pulmonary diseases.

Polycaprolactone Electrospun Scaffolds Produce an Enrichment of Lung Cancer Stem Cells in Sensitive and Resistant EGFRm Lung Adenocarcinoma

Simple Summary

The culture of lung cancer stem cells (LCSCs) is not possible using traditional flat polystyrene surfaces. The study of these tumor-initiating cells is fundamental due to their key role in the resistance to anticancer therapies, tumor recurrence, and metastasis. Hence, we evaluated the use of polycaprolactone electrospun (PCL-ES) scaffolds for culturing LCSC population in sensitive and resistant EGFR-mutated lung adenocarcinoma models. Our findings revealed that both cell models seeded on PCL-ES structures showed a higher drug resistance, enhanced levels of several genes and proteins related to epithelial-to-mesenchymal process, stemness, and surface markers, and the activation of the Hedgehog pathway. We also determined that the non-expression of CD133 was associated with a low degree of histological differentiation, disease progression, distant metastasis, and worse overall survival in EGFR-mutated non-small cell lung cancer patients. Therefore, we confirmed PCL-ES scaffolds as a suitable three-dimensional cell culture model for the study of LCSC niche.

Abstract

The establishment of a three-dimensional (3D) cell culture model for lung cancer stem cells (LCSCs) is needed because the study of these stem cells is unable to be done using flat surfaces. The study of LCSCs is fundamental due to their key role in drug resistance, tumor recurrence, and metastasis. Hence, the purpose of this work is the evaluation of polycaprolactone electrospun (PCL-ES) scaffolds for culturing LCSCs in sensitive and resistant EGFR-mutated (EGFRm) lung adenocarcinoma cell models. We performed a thermal, physical, and biological characterization of 10% and 15%-PCL-ES structures. Several genes and proteins associated with LCSC features were analyzed by RT-qPCR and Western blot. Vimentin and CD133 tumor expression were evaluated in samples from 36 patients with EGFRm non-small cell lung cancer through immunohistochemistry. Our findings revealed that PC9 and PC9-GR3 models cultured on PCL-ES scaffolds showed higher resistance to osimertinib, upregulation of ABCB1, Vimentin, Snail, Twist, Sox2, Oct-4, and CD166, downregulation of E-cadherin and CD133, and the activation of Hedgehog pathway. Additionally, we determined that the non-expression of CD133 was significantly associated with a low degree of histological differentiation, disease progression, and distant metastasis. To sum up, we confirmed PCL-ES scaffolds as a suitable 3D cell culture model for the study of the LCSC niche.

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.

Targeting cancer stem cell pathways for cancer therapy

Since cancer stem cells (CSCs) were first identified in leukemia in 1994, they have been considered promising therapeutic targets for cancer therapy. These cells have self-renewal capacity and differentiation potential and contribute to multiple tumor malignancies, such as recurrence, metastasis, heterogeneity, multidrug resistance, and radiation resistance. The biological activities of CSCs are regulated by several pluripotent transcription factors, such as OCT4, Sox2, Nanog, KLF4, and MYC. In addition, many intracellular signaling pathways, such as Wnt, NF-κB (nuclear factor-κB), Notch, Hedgehog, JAK-STAT (Janus kinase/signal transducers and activators of transcription), PI3K/AKT/mTOR (phosphoinositide 3-kinase/AKT/mammalian target of rapamycin), TGF (transforming growth factor)/SMAD, and PPAR (peroxisome proliferator-activated receptor), as well as extracellular factors, such as vascular niches, hypoxia, tumor-associated macrophages, cancer-associated fibroblasts, cancer-associated mesenchymal stem cells, extracellular matrix, and exosomes, have been shown to be very important regulators of CSCs. Molecules, vaccines, antibodies, and CAR-T (chimeric antigen receptor T cell) cells have been developed to specifically target CSCs, and some of these factors are already undergoing clinical trials. This review summarizes the characterization and identification of CSCs, depicts major factors and pathways that regulate CSC development, and discusses potential targeted therapy for CSCs.

A typical carcinoid of the lung - a case report with pathological correlation and propagation of the cancer stem cell line BKZ1 with synaptophysin expression

RATIONALE

Neuroendocrine tumors (NETs) of the lung account for 5% of all cases of lung cancer, which itself is the leading cause of cancer-related death worldwide. In accordance to its rarity, only few cell lines of NETs exist, which even often lack key characteristics of the primary tumor, making it difficult to study underlying molecular mechanisms.

PATIENT CONCERNS

The patient reported in this case is a 71-year old woman, which never smoked but suffered under dry cough.

DIAGNOSES

Chest CT-scan showed a paracardiac nodule of the lingula with 2 × 1.8 cm in diameter.

INTERVENTIONS

The detected paracardiac nodule of the lingula was anatomically resected using video assisted thoracic surgery.

OUTCOMES

Histopathological diagnostic of the removed tissue identified the tumor as a well-differentiated typical carcinoid (TC), which represents one of the four subgroups of pulmonary NETs. Next to the successful treatment of the patient, we were able to propagate cancer stem cells (CSCs) out of the resected tumor tissue. To the best of our knowledge, we firstly isolated CSCs of a typical carcinoid, which were positive for the prominent CSC markers CD44, CD133 and nestin, confirming their stem cell properties. Additionally, CSCs, further referred as BKZ1, expressed the neuroendocrine marker synaptophysin, verifying their neuroendocrine origin. However, nuclear synaptophysin protein was also present in other stem cell populations, suggesting a role as general stem cell marker.

LESSON

In line with the importance of CSCs in cancer treatment and the lack of CSC-models for neuroendocrine neoplasms, the here described BKZ1 cancer stem cell line of a typical carcinoid represents a promising new model to study pulmonary carcinoids and particular NETs.

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.

Association of SOX2 and Nestin DNA amplification and protein expression with clinical features and overall survival in non-small cell lung cancer: A systematic review and meta-analysis

Up to now, the prognosis of non-small cell lung cancer (NSCLC) is poor. With progress of cancer biology, a number of genes have been investigated for predicting prognosis of NSCLC, such as cancer stem cell markers SRY (sex determining region Y)-box 2 (SOX2) and Nestin. Recently, a series of studies have been performed to examine the associations of SOX2 and Nestin with clinical parameters and prognosis in NSCLC, however, the results were not consistent. In the present study, we conducted a systematic review and meta-analysis to summarize the associations. Four English databases (PubMed, ISI web of science, Embase, and Ovid) were used to search the relevant studies with the last date of November 10, 2015. The pooling analyses were stratified by DNA amplification and protein expression. The pooling ORs or HRs were used to assess the strength of the associations. Finally, we included 19 articles for SOX2 and six articles for Nestin according to the inclusion and exclusion criteria. The pooling analyses revealed that there were significant associations between SOX2 DNA amplification and clinical features of NSCLC, gender, smoking status, squamous cell cancer (SCC) histology, and differentiations. And significant associations were also identified between SOX2 protein expression and clinical parameters, smoking status and SCC histology. For Nestin, its protein expression was correlated with lymph node metastasis and stage. Simultaneously, we found that high/positive SOX2 alterations, either DNA amplification or protein expression, were favorable for overall survival (OS) in NSCLC. On the contrary, high/positive Nestin protein expression was poor for OS.

Clinicopathological and prognostic significance of Nestin expression in patients with non-small cell lung cancer: a systematic review and meta-analysis

Latest evidence indicates that Nestin expression may be associated with the high malignancy and poor prognosis of non-small cell lung cancer (NSCLC), but a relevant consensus has not been reached until now. Therefore, we conducted this meta-analysis to evaluate the clinicopathological and prognostic significance of Nestin expression in patients with NSCLC. We searched PubMed, EMBASE and the Web of Science for eligible full-text articles. Odds ratio (OR) and hazard ratio (HR) with 95 % confidence interval (95 % CI) severed as the summarized statistics. Q-test and I ²-statistic were applied to evaluate the heterogeneity, and sensitivity analysis was conducted for adjustments. Publication bias was detected by Begg's test and Egger's test. Finally, eight eligible articles with 834 NSCLC cases were included. Nestin expression was found to be significantly associated with the unfavorable outcomes of differentiation degree (OR: 2.47; 95 % CI 1.61-3.79; P < 0.001), lymphatic metastasis (OR: 2.45; 95 % CI 1.41-4.25; P = 0.001), TNM stage (OR: 1.73; 95 % CI 1.07-2.79; P = 0.025) and tumor size (OR: 2.68; 95 % CI 1.20-5.98; P = 0.016), but not associated with gender, age, smoking status and NSCLC subtypes. Nestin expression could significantly predict the lower overall survival of NSCLC (HR: 2.41; 95 % CI 1.72-3.38; P < 0.001). The prognostic value of Nestin remained statistically reliable in the subgroups stratified by statistical analysis, patients' origins and follow-up periods, but not significant in patients with squamous cell carcinoma. In conclusion, Nestin expression may be an independent predictor for the poor prognosis and clinicopathological characteristics of NSCLC. Further studies are necessary to validate our discoveries.

Enhancement of Radiation Sensitivity in Lung Cancer Cells by a Novel Small Molecule Inhibitor That Targets the β-Catenin/Tcf4 Interaction

Radiation therapy is an important treatment choice for unresectable advanced human lung cancers, and a critical adjuvant treatment for surgery. However, radiation as a lung cancer treatment remains far from satisfactory due to problems associated with radiation resistance in cancer cells and severe cytotoxicity to non-cancer cells, which arise at doses typically administered to patients. We have recently identified a promising novel inhibitor of β-catenin/Tcf4 interaction, named BC-23 (C₂₁H₁₄ClN₃O₄S), which acts as a potent cell death enhancer when used in combination with radiation. Sequential exposure of human p53-null non-small cell lung cancer (NSCLC) H1299 cells to low doses of x-ray radiation, followed 1 hour later by administration of minimally cytotoxic concentrations of BC-23, resulted in a highly synergistic induction of clonogenic cell death (combination index <1.0). Co-treatment with BC-23 at low concentrations effectively inhibits Wnt/β-catenin signaling and down-regulates c-Myc and cyclin D1 expression. S phase arrest and ROS generation are also involved in the enhancement of radiation effectiveness mediated by BC-23. BC-23 therefore represents a promising new class of radiation enhancer.

HABP2 is a Novel Regulator of Hyaluronan-Mediated Human Lung Cancer Progression

Background

Lung cancer is a devastating disease with limited treatment options. Many lung cancers have changes in their microenvironment including upregulation of the extracellular matrix glycosaminoglycan, hyaluronan (HA), which we have previously demonstrated can regulate the activity of the extracellular serine protease, hyaluronan binding protein 2 (HABP2). This study examined the functional role of HABP2 on HA-mediated human lung cancer dynamics.

Methods

Immunohistochemical analysis was performed on lung cancer patient samples using anti-HABP2 antibody. Stable control, shRNA, and HABP2 overexpressing human lung adenocarcinoma cells were evaluated using immunoblot analysis, migration, extravasation, and urokinase plasminogen activator (uPA) activation assays with or without high-molecular weight HA or low-molecular weight HA (LMW-HA). In human lung cancer xenograft models, primary tumor growth rates and lung metastasis were analyzed using consecutive tumor volume measurements and nestin immunoreactivity in nude mouse lungs.

Results

We provide evidence that HABP2 is an important regulator of lung cancer progression. HABP2 expression was increased in several subtypes of patient non-small cell lung cancer samples. Further, HABP2 overexpression increased LMW-HA-induced uPA activation, migration, and extravasation in human lung adenocarcinoma cells. In vivo, overexpression of HABP2 in human lung adenocarcinoma cells increased primary tumor growth rates in nude mice by ~2-fold and lung metastasis by ~10-fold compared to vector control cells (n = 5/condition).

Conclusion

Our data suggest a possible direct effect of HABP2 on uPA activation and lung cancer progression. Our observations suggest that exploration of HABP2 in non-small cell lung carcinoma merits further study both as a diagnostic and therapeutic option.

Nestin as a marker of cancer stem cells

The crucial role of cancer stem cells (CSCs) in the pathology of malignant diseases has been extensively studied during the last decade. Nestin, a class VI intermediate filament protein, was originally detected in neural stem cells during development. Its expression has also been reported in different tissues under various pathological conditions. Specifically, nestin has been shown to be expressed in transformed cells of various human malignancies, and a correlation between its expression and the clinical course of some diseases has been proved. Furthermore, the coexpression of nestin with other stem cell markers was described as a CSC phenotype that was subsequently verified using tumorigenicity assays. The primary aim of this review is to summarize the recent findings regarding nestin expression in CSCs, its possible role in CSC phenotypes, particularly with respect to capacity for self-renewal, and its utility as a putative marker of CSCs.

Re-Punching Tissue Microarrays Is Possible: Why Can This Be Useful and How to Do It

Tissue microarray (TMA) methodology allows the concomitant analysis of hundreds of tissue specimens arrayed in the same manner on a recipient block. Subsequently, all samples can be processed under identical conditions, such as antigen retrieval procedure, reagent concentrations, incubation times with antibodies/probes, and escaping the inter-assays variability. Therefore, the use of TMA has revolutionized histopathology translational research projects and has become a tool very often used for putative biomarker investigations. TMAs are particularly relevant for large scale analysis of a defined disease entity. In the course of these exploratory studies, rare subpopulations can be discovered or identified. This can refer to subsets of patients with more particular phenotypic or genotypic disease with low incidence or to patients receiving a particular treatment. Such rare cohorts should be collected for more specific investigations at a later time, when, possibly, more samples of a rare identity will be available as well as more knowledge derived from concomitant, e.g., genetic, investigations will have been acquired. In this article we analyze for the first time the limits and opportunities to construct new TMA blocks using tissues from older available arrays and supplementary donor blocks. In summary, we describe the reasons and technical details for the construction of rare disease entities arrays.

Novel strategies targeting cancer stem cells through phytochemicals and their analogs

Cancer stem cells (CSCs) are cells that exist within a tumor with a capacity of self-renewal and an ability to differentiate, giving rise to heterogeneous populations of cancer cells. These cells are increasingly being implicated in resistance to conventional therapeutics and have also been implicated in tumor recurrence. Several cellular signaling pathways including Notch, Wnt, phosphoinositide-3-kinase-Akt-mammalian target of rapamycin pathways, and known markers such as CD44, CD133, CD166, ALDH, etc. have been associated with CSCs. Here, we have reviewed our current understanding of self-renewal pathways and factors that help in the survival of CSCs with special emphasis on those that have been documented to be modulated by well characterized natural agents such as curcumin, sulforaphane, resveratrol, genistein, and epigallocatechin gallate. With the inclusion of a novel derivative of curcumin, CDF, we showcase how natural agents can be effectively modified to increase their efficacy, particularly against CSCs. We hope that this article will generate interest among researchers for further mechanistic and clinical studies exploiting the cancer preventive and therapeutic role of nutraceuticals by targeted elimination of CSCs.

The changes of angiogenesis and immune cell infiltration in the intra- and peri-tumoral melanoma microenvironment

Malignant melanoma (MM) urgently needs identification of new markers with better predictive value than currently-used clinical and histological parameters. Cancer cells stimulate the formation of a specialized tumor microenvironment, which reciprocally affects uncontrolled proliferation and migration. However, this microenvironment is heterogeneous with different sub-compartments defined by their access to oxygen and nutrients. This study evaluated microvascular density (MVD), CD3+ lymphocytes (TILs) and FOXP3+ T-regulatory lymphocytes (Tregs) on formalin-fixed paraffin-embedded tissue sections using light microscopy. We analyzed 82 malignant melanomas, divided according to the AJCC TNM classification into four groups--pT1 (35), pT2 (17), pT3 (18) and pT4 (12)--and 25 benign pigmented nevi. All parameters were measured in both the central areas of tumors (C) and at their periphery (P). A marked increase in all parameters was found in melanomas compared to nevi (p = 0.0001). There was a positive correlation between MVD, TILs, FOXP3+ Tregs and the vertical growth phase. The results show that MVD, TILs and FOXP3+ Tregs substantially influence cutaneous melanoma microenvironment. We found significant topographic differences of the parameters between central areas of tumors and their boundaries.

High CD133 expression in the nucleus and cytoplasm predicts poor prognosis in non-small cell lung cancer

Objective. The aim of this study was to investigate the expression of Prominin-1 (CD133) in cancer cells and its potential value as a prognostic indicator of survival in patients with non-small cell lung cancer (NSCLC). Methods. Cancerous tissues and matched normal tissues adjacent to the carcinoma from 239 NSCLC patients were obtained immediately after surgery. Immunohistochemistry of tissue microarrays was used to characterize the expression of CD133 in NSCLC and adjacent tissues. The correlation of CD133 expression with clinical characteristics and prognosis was determined by statistical analysis. Results. CD133 protein expression levels in both the cytoplasm and nucleus were significantly higher in NSCLC tissues compared with corresponding peritumoral tissue (P < 0.05). CD133 expression in the nucleus of NSCLC cells was related to tumor diameter (P = 0.027), tumor differentiation (P < 0.001), and TNM stage (P = 0.007). Kaplan-Meier survival and Cox regression analyses revealed that high CD133 expression in the nucleus was an independent predictor of poor prognosis of NSCLC, as was high cytoplasmic CD133 expression (P < 0.001). Conclusion. Our findings provide the first evidence that high expression of CD133 in both the nucleus and cytoplasm is associated with poor prognosis in NSCLC.

Downregulation of Msi1 suppresses the growth of human colon cancer by targeting p21cip1

Musashi1 (Msi1), a member of the RNA-binding protein (RBP) family, is highly expressed in neural progenitor or stem cells for the maintenance of stemness as well as in various cancers. Emerging studies have demonstrated that it regulates cell processes by translational activation or suppresses specifically bound mRNA. In the present study, we initially reported remarkably increased expression of Msi1 in colon cancer tissues compared with adjacent non-tumor tissues. Knockdown of Msi1 significantly suppressed the proliferation, colony formation, tumorsphere formation and the progression of implanted colon cancers, and induced cell cycle attest at G0/G1 phase, along with the upregulated expression of p21(cip1). Reporter assays using a chimeric mRNA that combined luciferase and the 3'-UTR of p21(cip1) revealed that Msi1 decreased the reporter activity through the specific motif. Thus, the current results suggested that downregulation of Msi1 could inhibit the growth of colon cancers and Msi1 may be a promising therapeutic target molecule for human colon cancers.

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

Background

The clinical and prognostic significance of CD133 in non-small-cell lung cancer (NSCLC) remains controversial. To clarify a precise determinant of the clinical significance of CD133, we conducted a systematic review and meta-analysis to evaluate the association of CD133 with prognosis and clinicopathological features of NSCLC patients.

Methods

The electronic and manual searches were performed through the database of Pubmed, Medline, Web of Science, Scopus, and Chinese CNKI (from January 1, 1982 to January 1, 2014) for titles and abstracts by using the following keywords: “CD133”, “ac133” or “Prominin-1”, and “lung cancer” to identify the studies eligible for our analysis. Meta-analysis was performed by using Review Manager 5.0 and the outcomes included the overall survival and various clinicopathological features.

Results

A total of 23 studies were finally included, and our results showed that CD133 level was significantly correlated with the overall survival (OR = 2.25, 95% CI: 1.24–4.07, P = 0.008) of NSCLC patients but not with the disease free survival (OR = 1.33, 95% CI = 0.77–2.30, P = 0.31). With respect to clinicopathological features, CD133 level was positively correlated with lymph node metastasis (OR = 1.99, 95%CI = 1.06–3.74, P = 0.03), but not correlated with the histological classification (OR = 1.00, 95%CI = 0.81–1.23, P = 0.99(ac), OR = 0.87, 95%CI = 0.61–1.24, P = 0.45(sc)), or differentiation (OR = 0.94, 95%CI 0.53–1.68, Z = 0.20, P = 0.84 random-effect) of NSCLC patients.

Conclusion

High level of CD133 expression trends to correlate with a worse prognosis and a higher rate of lymph node metastasis in NSCLC patients, revealing CD133 as a potential pathological prognostic marker for NSCLC patients.

Clinicopathological significance of cancer stem cells marked by CD133 and KAI1/CD82 expression in laryngeal squamous cell carcinoma

Background

Presently, CD133 is one of the hottest markers to characterize cancer stem cells and KAI1/CD82 is reported as an important marker for the metastasis and prognosis of many cancers. The purpose of our study is to explore the relationship between cancer stem cells (CSCs) marked by CD133 and KAI1/CD82 expression and the clinicopathological characteristics of patients with laryngeal squamous cell carcinoma (LSCC).

Methods

Immunohistochemical analysis was used to detect the expression of CD133 and KAI1/CD82 in 83 archival surgical specimens of human LSCC and 83 cases of normal laryngeal tissues.

Results

In LSCC, positive rates of 49.4% and 41.0% were obtained for CD133 and KAI1/CD82, respectively. The expression of CD133 in LSCC tissues was significantly higher than that in normal tissues (P < 0.001), and the expression of CD133 was positively associated with pTNM stage (P = 0.005), pathological grade (P = 0.001), and lymph node metastasis (P < 0.001). The reduced expression of KAI1/CD82 was present in LSCC tissues. The positive rate of KAI1/CD82 expression was negatively correlated with pTNM stage (P = 0.014), pathological grade (P < 0.001), and lymph node metastasis (P = 0.007). A correlation analysis showed that there was a negative relationship between the expression of CD133 and KAI1/CD82 protein in LSCC tissues (P < 0.001). By Kaplan-Meier analysis, the expression of CD133 was negatively correlated with overall survival (OS) (log-rank = 40.949, P < 0.001) and disease-free survival (DFS) (log-rank = 39.307, P < 0.001) time of LSCC. The expression of KAI1/CD82 was positively correlated with OS (log-rank = 40.279, P < 0.001) and DFS (log-rank = 39.271, P < 0.001) time of LSCC. Cox regression analysis: the expression of CD133 and KAI1/CD82, and pTNM stages were independent prognostic factors of LSCC (P < 0.05).

Conclusions

Thus the detection of CD133 and KAI1/CD82 proteins may be used as a potential indicator of LSCC prognosis.

Nestin regulates proliferation, migration, invasion and stemness of lung adenocarcinoma

Lung cancer is the most common cancer and the most common cause of cancer-related death in the world. Nestin, a class VI intermediate filament, is known to be a cancer stem cell (CSC) marker as well as a neuroepithelial stem cell marker. High expression levels of nestin are reported in several types of cancers including lung, pancreatic and prostate cancers. Nestin is thought to regulate tumor cell proliferation, migration, invasion and CSC properties. Here, we confirmed nestin expression in non-small cell lung cancer (NSCLC): Immunohistochemical analysis in surgical specimens detected nestin protein expression in the cytoplasm of 20 of 48 adenocarcinoma (AD) cases (41.7%) and 25 of 47 squamous cell carcinoma cases (53.2%). Nestin immunoreactivity significantly correlated with not only tumor size and lymph node metastasis in NSCLC, but also poor survival in surgical patients with AD. High and moderate expression levels of nestin were confirmed in several lung AD cell lines including H1975 and PC-3. Nestin inhibition by shRNA decreased proliferation, migration, invasion and sphere formation in AD cells. Correspondingly, nestin upregulation by nestin gene transfection resulted in the opposite changes. Moreover, Akt inhibitor IV effectively decreased nestin expression via SRY-box containing protein 2 (Sox2) downregulation and overcame the enhanced sphere formation induced by nestin upregulation. Overall, our results show that nestin correlates with the aggressiveness and stemness of AD. Regulation of nestin via Akt/Sox2 is, thus, a promising candidate for novel therapeutic approaches to eradicate CSCs in lung AD.

Lung cancer stem cell: fancy conceptual model of tumor biology or cornerstone of a forthcoming therapeutic breakthrough?

Cancer research has received a fresh impetus from the concept of cancer stem cell (CSC) which postulates the existence of a tumor cell population uniquely endowed with self-renewal capacity and therapy resistance. Despite recent progresses including targeted therapy, lung cancer treatment remains a challenge owing largely to disease recurrence. Providing a conceptual model of tumor resistance and disease relapse, the lung CSC has received extensive attention, leading to a flourishing literature and several ongoing clinical trials. In this study, we will discuss the data suggesting the existence of CSC in lung tumors and the potential clinical utility of CSCs as prognostic markers or cellular targets of new therapeutic strategies. We will also touch on the new fundamental developments of the CSC concept that ought to be considered if the integration of the CSC concept into clinical practice is to be successful and impact on lung cancer treatment.

Small molecule antagonist of the bone morphogenetic protein type I receptors suppresses growth and expression of Id1 and Id3 in lung cancer cells expressing Oct4 or nestin

Background

Bone morphogenetic proteins (BMP) are embryonic morphogens that are aberrantly expressed in lung cancer. BMPs mediate cell fate decisions and self-renewal of stem cells, through transcription regulation of inhibitor of differentiation protein/DNA binding proteins (Id1-3). Inhibition of BMP signaling decreases growth and induces cell death of lung cancer cells lines by downregulating the expression of Id proteins. It is not known whether the BMP signaling cascade regulates growth and the expression of Id proteins of lung cancer cells expressing the stem cell markers Oct4 and/or nestin.

Methods

Lung cancer cells expressing Oct4 or nestin were isolated from lung cancer cell lines by stably transfecting the Oct4 promoter or nestin promoter expression vectors that induce expression of the green fluorescent protein reporter.

Results

Our studies suggest that lung cancer cells expressing Oct4 or nestin are different cell populations. Microarray and quantitative RT-PCR demonstrated that the expression of specific stem cell markers were different between isolated Oct4 and nestin cells. Both the Oct4 and nestin populations were more tumorigenic than controls but histologically they were quite different. The isolated Oct4 and nestin cells also responded differently to inhibition of BMP signaling. Blockade of BMP signaling with the BMP receptor antagonist DMH2 caused significant growth inhibition of both the Oct4 and nestin cell populations but only increased cell death in the nestin population. DMH2 also induced the expression of nestin in the Oct4 population but not in the nestin cells. We also show that BMP signaling is an important regulator of Id1 and Id3 in both the Oct4 and nestin cell populations. Furthermore, we show that NeuN is frequently expressed in NSCLC and provide evidence suggesting that Oct4 cells give rise to cancer cells expressing nestin and/or NeuN.

Conclusion

These studies show that although biologically different, BMP signaling is growth promoting in cancer cells expressing Oct4 or nestin. Inhibition of BMP signaling decreases expression of Id proteins and suppresses growth of cancer cells expressing Oct4 or Nestin. Small molecule antagonists of the BMP type I receptors represent potential novel drugs to target the population of cancer cells expressing stem cell markers.

Clinicopathological significance of CD133 in lung cancer: A meta-analysis

CD133 is one of the most commonly used markers of lung cancer stem cells (CSCs), which are characterized by their ability for self-renewal and tumorigenicity. However, the clinical value and significance of CD133 in lung cancer remains controversial. Due to the limited size of the individual studies, the association between CD133 and the clinicopathological characteristics of lung cancer had not been fully elucidated. A meta-analysis based on published studies was performed with the aim of evaluating the effect of CD133 on the clinicopathological characteristics of lung cancer and to investigate the role of CSCs in the prognosis of lung cancer. A total of 15 eligible studies were included in this meta-analysis and our results indicated that a positive CD133 expression was significantly associated with poor differentiation and lymph node metastasis, although it was not associated with tumor stage or histological type. Therefore, CD133 may be considered as a prognostic maker of lung cancer. Further clinical studies, with larger patient samples, unified methods and cut-off levels to detect CD133 expression, classified by tumor stage, therapeutic schedule, follow-up time and survival events, are required to determine the role of CD133 in clinical application and the association between CD133 and the prognosis of lung cancer.

Aberrant expression of CD133 in non-small cell lung cancer and its relationship to vasculogenic mimicry

Background

To investigate on expressions and clinical significances of CD133 protein and vasculogenic mimicry (VM) in primary non-small cell lung cancer (NSCLC).

Methods

The specimens of NSCLC from 305 Chinese patients with follow-up were analyzed for CD133 protein expression and VM by immunohistochemical and histochemical staining.

Results

In NSCLC, positive rates of 48.9% and 35.7% were obtained for CD133 and VM, respectively. The VM and expression of CD133 were significantly higher in carcinoma than in normal. There were a positive relationship between the VM and expression of CD133 and the tumor grade, lymph node metastasis and clinical stage (all P<0.05). The overall mean survival time of the patients with CD133 and VM positive expression was lower than that of patients with negative expression. Microvessel density (MVD) was positive corresponded with the grade, lymph node metastasis and clinical stage (all P<0.05). The overall mean survival time of the patients with MVD≥22’s group was shorter than that of patients with MVD<22’s group. Pathological-tumor-node-metastasis (pTNM) stage, positive expression of CD133 and VM, postoperative therapy and MVD were independent prognostic factors of NSCLC (P<0.05). Immunohistochemistry revealed an important intratumoral heterogeneity in all four CD133 expression profiles.

Conclusions

VM, MVD and expression of CD133 are related to differentiation, lymph node metastasis, clinical stage, and prognosis. It is suggested that CD133, VM and MVD should be considered as a potential marker for the prognosis.

Residual tumor cells that drive disease relapse after chemotherapy do not have enhanced tumor initiating capacity

Although chemotherapy is used to treat most advanced solid tumors, recurrent disease is still the major cause of cancer-related mortality. Cancer stem cells (CSCs) have been the focus of intense research in recent years because they provide a possible explanation for disease relapse. However, the precise role of CSCs in recurrent disease remains poorly understood and surprisingly little attention has been focused on studying the cells responsible for re-initiating tumor growth within the original host after chemotherapy treatment. We utilized both xenograft and genetically engineered mouse models of non-small cell lung cancer (NSCLC) to characterize the residual tumor cells that survive chemotherapy treatment and go on to cause tumor regrowth, which we refer to as tumor re-initiating cells (TRICs). We set out to determine whether TRICs display characteristics of CSCs, and whether assays used to define CSCs also provide an accurate readout of a cell's ability to cause tumor recurrence. We did not find consistent enrichment of CSC marker positive cells or enhanced tumor initiating potential in TRICs. However, TRICs from all models do appear to be in EMT, a state that has been linked to chemoresistance in numerous types of cancer. Thus, the standard CSC assays may not accurately reflect a cell's ability to drive disease recurrence.

CD133(+)EpCAM(+) phenotype possesses more characteristics of tumor initiating cells in hepatocellular carcinoma Huh7 cells

BACKGROUND

EpCAM or CD133 has been used as the tumor initiating cells (TICs) marker in hepatocellular carcinoma (HCC). We investigated whether cells expressing with both EpCAM and CD133 surface marker were more representative for TICs in hepatocellular carcinoma Huh7 cells.

METHODS

Four different phenotypes of CD133(+)EpCAM(+), CD133(+)EpCAM(-), CD133(-)EpCAM(+) and CD133(-)EpCAM(-) in Huh7 cells were sorted by flow cytometry. Then cell differentiation, self-renewal, drug-resistance, spheroid formation and the levels of stem cell-related genes were detected to compare the characteristics of TICs. The ability of tumorigenicity was measured in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice to verify TICs.

RESULTS

CD133(+)EpCAM(+) cells have many characteristics of TICs in Huh7 cells compared with CD133(+)EpCAM(-), CD133(-)EpCAM(+), CD133(-)EpCAM(-) cells, including enrichment in side population cells, higher differentiation capacity, increased colony-formation ability, preferential expression of stem cell-related genes, appearance of drug-resistant to some chemotherapeutics, more spheroid formation of culture cells and stronger tumorigenicity in NOD/SCID mice.

CONCLUSION

CD133(+)EpCAM(+) phenotype is precisely represented TICs in Huh7 cells. It might be useful for studying biology mechanism of TICs in hepatocellular carcinoma and screening new targets for cancer therapy.

CD133(+)EpCAM(+) phenotype possesses more characteristics of tumor initiating cells in hepatocellular carcinoma Huh7 cells

Background: EpCAM or CD133 has been used as the tumor initiating cells (TICs) marker in hepatocellular carcinoma (HCC). We investigated whether cells expressing with both EpCAM and CD133 surface marker were more representative for TICs in hepatocellular carcinoma Huh7 cells.

Methods: Four different phenotypes of CD133⁺EpCAM⁺, CD133⁺EpCAM^-, CD133^-EpCAM⁺ and CD133^-EpCAM^- in Huh7 cells were sorted by flow cytometry. Then cell differentiation, self-renewal, drug-resistance, spheroid formation and the levels of stem cell-related genes were detected to compare the characteristics of TICs. The ability of tumorigenicity was measured in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice to verify TICs.

Results: CD133⁺EpCAM⁺ cells have many characteristics of TICs in Huh7 cells compared with CD133⁺EpCAM^-, CD133^-EpCAM⁺, CD133^-EpCAM^- cells, including enrichment in side population cells, higher differentiation capacity, increased colony-formation ability, preferential expression of stem cell-related genes, appearance of drug-resistant to some chemotherapeutics, more spheroid formation of culture cells and stronger tumorigenicity in NOD/SCID mice.

Conclusion: CD133⁺EpCAM⁺ phenotype is precisely represented TICs in Huh7 cells. It might be useful for studying biology mechanism of TICs in hepatocellular carcinoma and screening new targets for cancer therapy.

The Role of PEC Progenitors in ADPKD Progression

BACKGROUND AND OBJECTIVES

Autosomal dominant polycystic kidney disease is a pathology mainly characterized by the progressive development and enlargement of cysts in each kidneys. Such as many adult epithelial tissue, renal tubule replaces damaged or death cells through the presence of stem/progenitor cells CD133(+)CD24(+) Obviously, in ADPKD the repair of damages is insufficient to block the disease, but renal stem cells could have a role in the pathology. In this study we investigate the localization and the involvement of cells CD133(+)CD24(+) in ADPKD progression.

METHODS AND RESULTS

Two normal kidneys and two ADPKD kidneys were examined. CD133 and CD24 expression was investigated by confocal microscopy and immunoblotting. Renal tissue and cells were analyzed. CD133 and CD24 have the same localization in ADPKD tissues and in normal kidneys: a subset of epithelial cells (PEC) of Bowman' s capsule and luminal side of tubules. It is interesting that CD133(+) CD24(+) cells are statistically more represented in ADPKD tubules (p＜ 0.001) and in healthy glomeruli (p= 0.0016). Cysts express CD133 and CD24.

CONCLUSIONS

Renal epithelial progenitors demonstrate to be involved in ADPKD pathogenesis but their role will have to be clarified and possibly managed to obtain improvement, or at least stabilization, of disease.

Efficient enrichment of hepatic cancer stem-like cells from a primary rat HCC model via a density gradient centrifugation-centered method

Background

Because few definitive markers are available for hepatic cancer stem cells (HCSCs), based on physical rather than immunochemical properties, we applied a novel method to enrich HCSCs.

Methodology

After hepatic tumor cells (HTCs) were first isolated from diethylinitrosamine-induced F344 rat HCC model using percoll discontinuous gradient centrifugation (PDGC) and purified via differential trypsinization and differential attachment (DTDA), they were separated into four fractions using percoll continuous gradient centrifugation (PCGC) and sequentially designated as fractions I–IV (FI–IV). Morphological characteristics, mRNA and protein levels of stem cell markers, proliferative abilities, induced differentiation, in vitro migratory capacities, in vitro chemo-resistant capacities, and in vivo malignant capacities were determined for the cells of each fraction.

Findings

As the density of cells increased, 22.18%, 11.62%, 4.73% and 61.47% of primary cultured HTCs were segregated in FI–FIV, respectively. The cells from FIII (density between 1.041 and 1.062 g/ml) displayed a higher nuclear-cytoplasmic ratio and fewer organelles and expressed higher levels of stem cell markers (AFP, EpCAM and CD133) than cells from other fractions (P<0.01). Additionally, in vitro, the cells from FIII showed a greater capacity to self-renew, differentiate into mature HTCs, transit across membranes, close scratches, and carry resistance to chemotherapy than did cells from any other fraction; in vivo, injection of only 1×10⁴ cells from FIII could generate tumors not only in subcutaneous tissue but also in the livers of nude mice.

Conclusions

Through our novel method, HCSC-like cells were successfully enriched in FIII. This study will greatly contribute to two important areas of biological interest: CSC isolation and HCC therapy.

The developing cancer stem-cell model: clinical challenges and opportunities

During the past decade, a stem-cell-like subset of cancer cells has been identified in many malignancies. These cells, referred to as cancer stem cells (CSCs), are of particular interest because they are believed to be the clonogenic core of the tumour and therefore represent the cell population that drives growth and progression. Many efforts have been made to design therapies that specifically target the CSC population, since this was predicted to be the crucial population to eliminate. However, recent insights have complicated the initial elegant model, by showing a dominant role for the tumour microenvironment in determining CSC characteristics within a malignancy. This is particularly important since dedifferentiation of non-tumorigenic tumour cells towards CSCs can occur, and therefore the CSC population in a neoplasm is expected to vary over time. Moreover, evidence suggests that not all tumours are driven by rare CSCs, but might instead contain a large population of tumorigenic cells. Even though these results suggest that specific targeting of the CSC population might not be a useful therapeutic strategy, research into the hierarchical cellular organisation of malignancies has provided many important new insights in the biology of tumours. In this Personal View, we highlight how the CSC concept is developing and influences our thinking on future treatment for solid tumours, and recommend ways to design clinical trials to assess drugs that target malignant disease in a rational fashion.

[Enrichment and function research of large cell lung cancer stem cell-like cells]

背景与目的

目前国内外还没有确切的、得到公认的肺癌干细胞的筛选标记分子、指标和方法，常用方法为通过流式细胞技术，借鉴其他肿瘤干细胞分选标记来分选肺癌干细胞，但其筛选特异性低、工作量巨大。本研究采用无血清悬浮培养法富集肺癌干细胞，对肺癌干细胞的筛选方法进行探索。

方法

采用添加生长因子的无血清培养基对人大细胞肺癌细胞株L9981进行悬浮培养，获得肺癌细胞球体。对含血清培养贴壁L9981细胞和无血清培养成球后的L9981细胞，通过显微镜下观察比较二者的生物学形态，应用Vi-cell细胞活力分析仪计数细胞并绘制生长曲线比较二者的增殖能力，通过Transwell实验研究它们的侵袭能力差异，并通过接种裸鼠观察二者在体内的成瘤性来研究肺癌细胞球体的生物学功能。

结果

与血清贴壁培养L9981细胞相比，无血清培养L9981细胞成球形生长，贴壁L9981和L9981球体细胞的倍增时间分别为（56.05±1.95）h和（33.00±1.44）h，球体细胞的侵袭和成瘤能力分别为贴壁L9981细胞的5倍和20倍。

结论

通过无血清悬浮培养的L9981细胞可以形成肺癌球体细胞群，L9981球体细胞的侵袭和成瘤能力均明显高于贴壁L9981细胞，显示L9981球体细胞中富集了肺癌干细胞样的细胞。无血清悬浮培养肺癌球体细胞可作为富集肺癌干细胞样细胞的一种候选方法。