CD133 expression and the prognosis of colorectal cancer: a systematic review and meta-analysis

Informed by Cancer Stem Cells of Solid Tumors: Advances in Treatments Targeting Tumor-Promoting Factors and Pathways

Cancer stem cells (CSCs) represent a subpopulation within tumors that promote cancer progression, metastasis, and recurrence due to their self-renewal capacity and resistance to conventional therapies. CSC-specific markers and signaling pathways highly active in CSCs have emerged as a promising strategy for improving patient outcomes. This review provides a comprehensive overview of the therapeutic targets associated with CSCs of solid tumors across various cancer types, including key molecular markers aldehyde dehydrogenases, CD44, epithelial cellular adhesion molecule, and CD133 and signaling pathways such as Wnt/β-catenin, Notch, and Sonic Hedgehog. We discuss a wide array of therapeutic modalities ranging from targeted antibodies, small molecule inhibitors, and near-infrared photoimmunotherapy to advanced genetic approaches like RNA interference, CRISPR/Cas9 technology, aptamers, antisense oligonucleotides, chimeric antigen receptor (CAR) T cells, CAR natural killer cells, bispecific T cell engagers, immunotoxins, drug-antibody conjugates, therapeutic peptides, and dendritic cell vaccines. This review spans developments from preclinical investigations to ongoing clinical trials, highlighting the innovative targeting strategies that have been informed by CSC-associated pathways and molecules to overcome therapeutic resistance. We aim to provide insights into the potential of these therapies to revolutionize cancer treatment, underscoring the critical need for a multi-faceted approach in the battle against cancer. This comprehensive analysis demonstrates how advances made in the CSC field have informed significant developments in novel targeted therapeutic approaches, with the ultimate goal of achieving more effective and durable responses in cancer patients.

Tumor cell stemness in gastrointestinal cancer: regulation and targeted therapy

The cancer stem cells are a rare group of self-renewable cancer cells capable of the initiation, progression, metastasis and recurrence of tumors, and also a key contributor to the therapeutic resistance. Thus, understanding the molecular mechanism of tumor stemness regulation, especially in the gastrointestinal (GI) cancers, is of great importance for targeting CSC and designing novel therapeutic strategies. This review aims to elucidate current advancements in the understanding of CSC regulation, including CSC biomarkers, signaling pathways, and non-coding RNAs. We will also provide a comprehensive view on how the tumor microenvironment (TME) display an overall tumor-promoting effect, including the recruitment and impact of cancer-associated fibroblasts (CAFs), the establishment of an immunosuppressive milieu, and the induction of angiogenesis and hypoxia. Lastly, this review consolidates mainstream novel therapeutic interventions targeting CSC stemness regulation.

A Validation Study of CD133 as a Reliable Marker for Identification of Colorectal Cancer Stem-Like Cells

Colorectal carcinoma (CRC) is maintained by putative colorectal cancer stem-like cells (CRC-CSCs) that are responsible for CRC metastasis and relapse. Targeting these CSCs can be an effective treatment of CRC. However, reliable identification of CRC-CSCs remains controversial due to the absence of specific markers. It is assumed that glycoprotein CD133 can serve as a useful marker for identification of CRC-CSCs. In this study, we employed CD133 as a marker to identify CRC-CSCs in human (LoVo, HCT116, and SW620) and mouse (CT26) CRC cell lines. In these lines, CD133+ cells were isolated and identified by magnetic-activated cell sorting and flow cytometry. Proliferation, colony formation, and drug resistance of CD133+ cells were analyzed in vitro, and their tumorigenicity was determined in vivo on mice. Proliferation, colony-forming ability, drug resistance, and tumorigenicity of CD133+ cells were higher than those of CD133- cells. Thus, cultured CD133+ cells had the characteristics of CSCs. Hence, glycoprotein CD133 is a reliable marker to identify CRC-CSCs. These results can be used for designing a novel therapeutic target in CRC treatment.

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.

Cryptolepine Suppresses Colorectal Cancer Cell Proliferation, Stemness, and Metastatic Processes by Inhibiting WNT/β-Catenin Signaling

Colorectal cancer (CRC) is the third most frequent cancer and the second leading cause of cancer-related deaths globally. Evidence shows that over 90% of CRC cases are initiated by a deregulated Wingless Integrated Type-1 (WNT)/β-catenin signaling pathway. The WNT/β-catenin pathway also promotes CRC cell proliferation, stemness, and metastasis. Therefore, modulators of the WNT/β-catenin pathway may serve as promising regimens for CRC. This study investigated the effect of cryptolepine-a plant-derived compound-on the WNT/β-catenin pathway in CRC. Two CRC cell lines, COLO205 and DLD1, were treated with cryptolepine or XAV 939 (a WNT inhibitor) in the presence or absence of WNT3a (a WNT activator). Using a tetrazolium-based assay, cryptolepine was found to reduce cell viability in a dose- and time-dependent manner and was a more potent inhibitor of viability than XAV 939. RT-qPCR analyses showed that cryptolepine reverses WNT3a-induced expression of β-catenin, c-MYC, and WISP1, suggesting that cryptolepine inhibits WNT3a-mediated activation of WNT/β-catenin signaling. Cryptolepine also repressed WNT3a-induced OCT4 and CD133 expression and suppressed colony formation of the cells, indicating that cryptolepine inhibits the stemness of CRC cells. Additionally, cryptolepine inhibited WNT3a-induced epithelial-to-mesenchymal transition by reducing the expression of SNAI1 and TWIST1 genes. In a wound healing assay, cryptolepine was found to suppress cell migration under unstimulated and WNT3a-stimulated conditions. Moreover, cryptolepine downregulated WNT3a-induced expression of MMP2 and MMP9 genes, which are involved in cancer cell invasion. Altogether, cryptolepine suppresses CRC cell proliferation, stemness, and metastatic properties by inhibiting WNT3a-mediated activation of the WNT/β-catenin signaling pathway. These findings provide a rationale for considering cryptolepine as a potential WNT inhibitor in CRC.

In vitro study to evaluate the effect of granulocyte colony stimulating factor on colorectal adenocarcinoma and on mesenchymal stem cells trans differentiation into cancer stem cells by cancer cells derived exosomes

Background

Colorectal cancer (CRC) is a common and lethal malignancies with poor prognosis. CRC cells release extracellular vesicles called exosomes to facilitate tumor progression by passing bioactive molecules such as proteins and nucleic acids between cells of the tumor and their microenvironment. Granulocyte colony stimulating factor (G-CSF) is a hematopoietic growth factor which mainly affects the lineage of neutrophil and exerts direct anti-tumor effects on various tumor types. The purpose of our study is to investigate the effect of G-CSF on CRC cells and to evaluate its capability to attenuate the potentiality of CRC cells derived exosomes to induce bone marrow-derived mesenchymal stem cells (BM-MSCs) malignant transformation into cancer stem cells (CSCs).

Results

The level of both lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT-1) (p = 0.014) & β-catenin (p = 0.01) was significantly decreased, whereas programmed cell death 4 (PDCD4) (p = 0.018) was increased in CRC exosomes pre-treated with G-CSF compared to untreated CRC exosomes. Additionally, there was a significant decrease in the cell proliferation in CRC cells pre-treated with G-CSF compared to untreated CRC cells (p = 0.008). Flow cytometric analysis of BM-MSCs showed that G-CSF could attenuate their transformation into CSCs.

Conclusion

G-CSF can be a promising therapeutic agent for CRC treatment.

New Horizons in Metastatic Colorectal Cancer: Prognostic Role of CD44 Expression

BACKGROUND

The transmembrane glycoprotein CD44, the major hyaluronan (HA) receptor, has been proven to regulate cell growth, survival, differentiation, and migration. It is therefore widely considered to be involved in carcinogenesis. Its role as a new therapeutic target in solid tumors is under evaluation in clinical trials. The prognostic value remains controversial. Here, we aimed to investigate the correlation between CD44 expression and the clinicopathological features and survival in metastatic colorectal cancer (mCRC) patients.

METHODS

Data from 65 mCRC patients of the Medical Oncology Unit, University Hospital and University of Cagliari were retrospectively collected from 2008 to 2021. Immunohistochemical analysis was performed at the Pathology Division, University Hospital of Cagliari on 3 μm thick sections obtained from paraffin blocks. The intensity of immunohistochemical staining was subclassified into four groups: score 0 if negative or weak membrane staining in less than 10% of tumor cells; score 1+ if weak membrane staining in at least 10% of tumor cells or moderate membrane staining in less than 10% of tumor cells; score 2+ if moderate membrane staining in at least 10% of tumor cells or intensive membrane staining in less than 10% of tumor cells; score 3+ if intense membrane staining in at least 10% of tumor cells. Based on this score, we distinguished patients into low CD44 expression (score 0, 1+, 2+) and high CD44 expression (score 3+). Statistical analysis was performed with MedCalc (survival distribution: Kaplan-Meier; survival comparison: log-rank test; association between categorical variables: Fisher's exact test).

RESULTS

Patients' median age was 66 years (range 49-85). Regarding CD44 expression, score was 0 in 18 patients, 1+ in 15 patients, 2+ in 18 patients, and 3+ in 14 patients. Median overall survival (mOS) was 28.1 months (95%CI: 21.3-101). CD44 overexpression (3+) was correlated with poor prognosis (p = 0.0011; HR = 0.2), with a mOS of 14.5 months (95%CI 11.7 to 35.9) versus 30.7 months (95%CI 27.8 to 101) in lower CD44 expression. Higher CD44 expression was associated with clinically poor prognostic features: age ≥ 70 years (p = 0.0166); inoperable disease (p = 0.0008); stage IV at diagnosis (p = 0.0241); BRAF mutated (p = 0.0111), high-grade tumor (p = 0.0084).

CONCLUSIONS

CD44 markedly correlated with aggressive tumor behavior and contributed to the earlier progression of disease, thus suggesting its role as a novel prognostic marker and potential therapeutic target for mCRC patients.

The cAMP/PKA/CREB and TGFβ/SMAD4 Pathways Regulate Stemness and Metastatic Potential in Colorectal Cancer Cells

SIGNIFICANCE

This study identifies signaling pathways essential for maintaining the stemness and metastatic potential of colorectal cancer cells and proposes CREB as a therapeutic target in metastatic colorectal cancer.

Expression and Prognostic Significance of Stem Cell Marker CD133 in Survival Rate of Patients with Colon Cancer

INTRODUCTION

Today, colon cancer is one of the most common types of gastrointestinal cancer worldwide. CD133 as a known cancer stem cell marker has been found effective in cell proliferation and differentiation in various cancers, including colon cancer. We aimed to investigate the relationship between CD133 expression in colon cancer with prognostic factors and survival rate of patients with colon cancer by immunohistochemistry.

METHODS

Formalin-fixed paraffin-embedded (FFPE) tissue was taken from patients with colon cancer. Histopathology examination was done using hematoxylin and eosin staining. Immunohistochemistry was performed to determine CD133 expression. Association between CD133 expression and clinicopathological profile was then assessed.

RESULTS

There was a statistically significant association between CD133 protein expression and sex , cancer stage, and lymphatic invasion (p = 0.044, p = 0.131, and p = 0.002, respectively). However, no significant correlation was identified between CD133 expression and other factors, including age of patients with colorectal cancer (CRC) (p = 0.267), tumor location (p = 0.494), tumor differentiation grade (p = 0.263), neural tissue invasion, and 5-year survival (p = 0.054).

CONCLUSION

CD133 is a useful predictive or prognostic biomarker for CRC in clinical assessment and may serve as a potential therapeutic target for CRC.

Cancer stem cell marker expression and methylation status in patients with colorectal cancer

The number of individuals diagnosed with colorectal cancer (CRC) has been on an alarming upward trajectory over the past decade. In some countries, this cancer represents one of the most frequently diagnosed types of neoplasia. Therefore, it is an important demand to study the pathology underlying this disease to gain insights into the mechanism of resistance to treatment. Resistance of tumors to chemotherapy and tumor aggressiveness have been associated with a minor population of neoplastic cells, which are considered to be responsible for tumor recurrence. These types of neoplastic cells are known as cancer stem cells, which have been previously reported to serve an important role in pathogenesis of this malignant disease. Slovakia has one of the highest incidence rates of CRC worldwide. In the present study, the aim was to classify the abundance of selected stem cell markers (CD133, CD166 and Lgr5) in CRC tumors using flow cytometry. In addition, the methylation status of selected genomic regions of CRC biomarkers (ADAMTS16, MGMT, PROM1 (CD133), LGR5 and ALCAM) was investigated by pyrosequencing in a cohort of patients from Martin University Hospital, Martin, Slovakia. Samples from both primary tumors and metastatic tumors were tested. Analysis of DNA methylation in the genomic regions of indicated five CRC biomarkers was also performed, which revealed the highest levels of methylation in the A disintegrin and metalloproteinase with thrombospondin motifs 16 and O6-methyguanine-DNA methyl transferase genes, whereas the lowest levels of methylation were found in genes expressing prominin-1, leucine-rich repeat-containing G-protein-coupled receptor 5 and activated leukocyte cell adhesion molecule. Furthermore, tumor tissues from metastases showed significantly higher levels of CD133⁺ cells compared with that in primary tumors. Higher levels of CD133⁺ cells correlated with TNM stage and the invasiveness of CRC into the lymphatic system. Although relatively small number of samples was processed, CD133 marker was consider to be important marker in pathology of CRC.

Therapeutic strategies targeting Wnt/β‑catenin signaling for colorectal cancer (Review)

Colorectal cancer (CRC) is one of the most common carcinomas. Although great progress has been made in recent years, CRC survival remains unsatisfactory due to high metastasis and recurrence. Understanding the underlying molecular mechanisms of CRC tumorigenesis and metastasis has become increasingly important. Recently, aberrant Wnt/β‑catenin signaling has been reported to be strongly associated with CRC tumorigenesis, metastasis and recurrence. Therefore, the Wnt/β‑catenin signaling pathway has potential value as a therapeutic target for CRC. In the present review, the dysregulation of this pathway in CRC and the promoting or suppressing function of therapeutic targets on CRC were explored. In addition, the interaction between this pathway and epithelial‑mesenchymal transition (EMT), cell stemness, mutations, metastasis‑related genes and tumor angiogenesis in CRC cells were also investigated. Numerous studies on this pathway may help identify the potential diagnostic and prognostic markers and therapeutic targets for CRC.

Epithelial-to-Mesenchymal Plasticity in Circulating Tumor Cell Lines Sequentially Derived from a Patient with Colorectal Cancer

Simple Summary

Metastasis is a complex dynamic multistep process; however, our knowledge is still limited. Very few circulating tumor cells (CTCs) are metastatic precursor cells and represent the intermediate stage of metastasis. Epithelial–mesenchymal plasticity (EMP) has crucial roles in tissue development and homeostasis, and also in metastasis formation. In this study, we explored the EMP phenotype of a unique series of CTC lines, obtained from a patient with colon cancer during the disease course and treatment, by detecting markers involved in the epithelial–mesenchymal and mesenchymal–epithelial (MET) transitions. This study shows that these colon CTC lines have acquired only few mesenchymal features to migrate and intravasate, whereas an increase of MET-related markers was observed, suggesting that metastasis-competent CTCs need to revert quickly to the epithelial phenotype to reinitiate a tumor at a distant site.

Abstract

Metastasis is a complicated and only partially understood multi-step process of cancer progression. A subset of cancer cells that can leave the primary tumor, intravasate, and circulate to reach distant organs are called circulating tumor cells (CTCs). Multiple lines of evidence suggest that in metastatic cancer cells, epithelial and mesenchymal markers are co-expressed to facilitate the cells’ ability to go back and forth between cellular states. This feature is called epithelial-to-mesenchymal plasticity (EMP). CTCs represent a unique source to understand the EMP features in metastatic cascade biology. Our group previously established and characterized nine serial CTC lines from a patient with metastatic colon cancer. Here, we assessed the expression of markers involved in epithelial–mesenchymal (EMT) and mesenchymal–epithelial (MET) transition in these unique CTC lines, to define their EMP profile. We found that the oncogenes MYC and ezrin were expressed by all CTC lines, but not SIX1, one of their common regulators (also an EMT inducer). Moreover, the MET activator GRHL2 and its putative targets were strongly expressed in all CTC lines, revealing their plasticity in favor of an increased MET state that promotes metastasis formation.

Clinical relevance of stem cell surface markers CD133, CD24, and CD44 in colorectal cancer

Colon cancer stem cells (CSC) identified by cell surface markers CD133, CD24, and CD44, have been shown to be involved with tumor formation, chemotherapy resistance, and the progression of metastatic disease. Using an in silico translational approach, we hypothesize that a combination of these CSC markers has prognostic value in a large cohort of patients with colorectal cancer. Clinicopathologic and RNA expression data from a total of 594 colorectal cancer (CRC) patients from TCGA were analyzed. The expression of CD133, CD24, and CD44 was individually defined as "high" or "low" based on the median expression. Disease specific survival (DSS) and overall survival (OS) were not associated with tumors that are CD133-high or CD44-high alone. Patients with CD24-high tumors have significantly better DSS (P<0.001) and OS (P = 0.043). CD24-high, CD44-high and CD133-high tumors were associated with significantly greater EGFR, KRAS and Ki67 expression (all P<0.001). CD133, CD24 and CD44-high tumors were independently enriched for conventional stemness-related signaling pathways such as Wnt/β-catenin and Hedgehog signaling pathways. There was no survival difference linked to CD133-high/CD44-low patients, but CD44-high/CD24-low patients have worse DSS (P = 0.005) compared with CD44-low/CD24-high patients. CD133-high/CD24-low tumors show significant negative enrichment of MYC targets, E2F targets, G2M checkpoint and mitotic spindle gene sets, suggesting less cell proliferation in these tumors. Patients with CD133-high/CD24-low tumors have worse DSS (P = 0.004) and OS (P = 0.044), and are more likely to have early and late recurrences. In conclusion, we demonstrated that CD133-high/CD24-low tumors may predict colorectal cancer prognosis.

Current understanding of epigenetics mechanism as a novel target in reducing cancer stem cells resistance

At present, after extensive studies in the field of cancer, cancer stem cells (CSCs) have been proposed as a major factor in tumor initiation, progression, metastasis, and recurrence. CSCs are a subpopulation of bulk tumors, with stem cell-like properties and tumorigenic capabilities, having the abilities of self-renewal and differentiation, thereby being able to generate heterogeneous lineages of cancer cells and lead to resistance toward anti-tumor treatments. Highly resistant to conventional chemo- and radiotherapy, CSCs have heterogeneity and can migrate to different organs and metastasize. Recent studies have demonstrated that the population of CSCs and the progression of cancer are increased by the deregulation of different epigenetic pathways having effects on gene expression patterns and key pathways connected with cell proliferation and survival. Further, epigenetic modifications (DNA methylation, histone modifications, and RNA methylations) have been revealed to be key drivers in the formation and maintenance of CSCs. Hence, identifying CSCs and targeting epigenetic pathways therein can offer new insights into the treatment of cancer. In the present review, recent studies are addressed in terms of the characteristics of CSCs, the resistance thereof, and the factors influencing the development thereof, with an emphasis on different types of epigenetic changes in genes and main signaling pathways involved therein. Finally, targeted therapy for CSCs by epigenetic drugs is referred to, which is a new approach in overcoming resistance and recurrence of cancer.

High expression of CD133 - stem cell marker for prediction of clinically agressive type of colorectal cancer

&lt;b&gt; Background:&lt;/b&gt; Colorectal cancer (CRC) is one of the most common malignancies in the world. The cancer stem cell (CSC) markers are associated with aggressive cancer types and poor prognosis. The objective of the study was to evaluate the CD133 expression and to correlate it with clinicopathological features in patients with CRC. &lt;br&gt;&lt;b&gt;Material and Methods:&lt;/b&gt; Our study included ninety patients with CRC who underwent curative surgical resection from 2012 to 2017 at the University Clinic for Digestive Surgery, Skopje, North Macedonia. Tumor samples were first analyzed with standard histopathological methods and then the CD133 expression was investigated immunohistochemically. The level of expression of CD133 was classified semiquantitatively. Low positivity was defined as positive immunoreactivity in &lt;50% of tumor glands, and high positivity was defined as positive immunoreactivity in ≥50% of tumor glands. Furthermore, clinicopathological features of patients were retrospectively reviewed. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; High expression of CD133 was found in 47.8% of patients' CRC samples. In 69.6% of patients with metastatic lesions in visceral organs we found high expression of CD133. We found statistically significant differences in the expression of CD133 between patients with and without visceral metastatic lesions (P = 0.0153), between patients with a different T category (P = 0.0119), N status (P = 0.0066) and grade (G) (P = 0.0115). Our results showed that the stage of disease has the greatest impact on expression of CD133 (P &lt; 0.00001). &lt;br&gt;&lt;b&gt;Conclusion:&lt;/b&gt; High expression of CD133 is a useful marker for prediction of the clinically aggressive type of CRC and can be routinely implemented in standard pathohistological diagnostics.

Gold nanoparticles conjugated with anti-CD133 monoclonal antibody and 5-fluorouracil chemotherapeutic agent as nanocarriers for cancer cell targeting

The enhanced permeability and retention effect allows for passive targeting of solid tumours by nanoparticles carrying anticancer drugs. However, active targeting by incorporation of various ligands onto nanoparticles can provide for a more selective and enhanced chemotherapeutic effect and complement the deficiencies of the passive targeting approach. Here we report on the design of the carboxyl-terminated PEGylated gold nanoparticles (AuNPs), their functionalization with anti-CD133 monoclonal antibody (mAb) via a crosslinking reaction, and subsequent 5-fluorouracil (5-FU) drug loading. The synthesized products in the form of stable colloids were characterised using a range of physicochemical techniques, including X-ray diffraction (XRD), UV-Vis spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Conjugation of anti-CD133 mAb onto PEGylated AuNPs was confirmed with the use of UV-Vis, BCA protein assay and fluorescence microscopy. HCT116 colorectal cancer cells abundantly expressed CD133: 92.4 ± 1.3%, as measured by flow cytometry. Whereas PEGylated AuNPs not conjugated with anti-CD133 mAb accumulated mainly at the cellular membrane, nanoparticles conjugated with anti-CD133 mAb were contained within the nuclear region of the cells. Anti-CD133 mAb conjugation facilitated the specific intracellular uptake due to specific antigen-antibody binding interaction. In vitro cytotoxicity studies on HCT116 cells showed that PEGylated AuNPs and PEGylated AuNPs-CD133 did not elicit any toxicity at any of the tested concentrations. Meanwhile, 5-FU-PEGylated AuNPs-CD133 significantly reduced the cell viability relative to the treatment with 5-FU-PEGylated AuNPs without anti-CD133 mAb conjugates (p < 0.0001). This study shows that the conjugation of nanocarriers with the anti-CD133 antibody improves the specific targeting of 5-FU against colorectal cancer cells. These results demonstrate that simultaneous functionalisation of PEGylated AuNPs with antibodies and chemotherapeutic drugs is a viable strategy to combat cancer through targeted drug delivery.

[Effectiveness of intraperitoneal chemotherapy for t4 colon cancer]

OBJECTIVE

To determine the effect of intraperitoneal chemotherapy (IPC) with mitomycin C on expression of intraperitoneal cancer cells markers in patients with T4 colon cancer.

MATERIAL AND METHODS

For the period from January 2019 to April 2020, 65 patients with T4 colon cancer were included in prospective comparative study. There were 46 patients in the main group and 19 patients in the control group. In the main group, surgical procedure was followed by IPC with mitomycin C. No IPC was performed in the control group. An effectiveness of IPC was evaluated using CD133, CD24, CD26, CD44, CD184 markers expression in peritoneal lavages.

RESULTS

Significant between-group differences were observed for CD133 (p=0.0168), CD24 (p=0.0455) and CD44 (p=0.0012). There was a tendency to decrease in the level of CD184 expression in both groups in the second lavage (p=0.0605).

CONCLUSION

IPC in patients with T4 colon cancer can reduce the expression and proliferative potential of free cancer cells.

Clinicopathological Significance of Tumor Stem Cell Markers ALDH1 and CD133 in Colorectal Carcinoma

Background & Objective:

Colorectal cancer (CRC) is the third most common cancer worldwide with a high mortality rate. The main causes of death in patients are recurrence and metastasis which are mainly attributed to the small subpopulation of cells within tumors called cancer stem cells (CSCs). This study aimed to evaluate the correlation between the expression of ALDH1 and CD133 as CSC associated markers and clinicopathological characteristics in CRC.

Methods:

In this cross-sectional study, a total of 483 CRC tumor samples were immunohistochemically stained for detection of CD133 and ALDH1 markers. Correlations of marker expression with clinicopathological factors were also evaluated.

Results:

There was a significant correlation between the luminal intensity of CD133 and neural invasion (P=0.05) and between the cytoplasmic intensity of CD133 and metastasis (P=0.05). In terms of H-score, a positive significant relation was observed between cytoplasmic expression of CD133 and lymph node (P=0.02), neural (P=0.04) and vascular invasion (P=0.02). The ALDH1 cytoplasmic expression showed a significant correlation with tumor size (P=0.001).

Conclusion:

Our findings showed that increased expression of CD133 and ALDH1 is associated with tumor progression and worse outcomes in CRC patients. These markers can be good candidates for localized targeting of CSCs using antibodies. Future researches need to be improved approaches for early detection of CRC, and treatment monitoring for CRC and other cancers.

Knocking down LSD1 inhibits the stemness features of colorectal cancer stem cells

As a top leading cause of cancer death in many countries, colorectal cancer (CRC) has drawn increasing attention to the study of the pathological mechanism. According to the “cancer stem cell hypothesis”, malignancies originate from a small fraction of cancer cells that show self-renewal properties to initiate and sustain tumor growth and tumor metastasis. Therefore, these cancer stem cells (CSC) probably play important roles in tumor recurrence, metastasis, and drug resistance. Previous research reported that lysine-specific histone demethylase 1 (LSD1) maintains cancer stemness through up-regulating stemness markers SOX2 and OCT4. CD133 is believed to be the most robust surface marker for CRC stem cells, however the regulatory effect of LSD1 on stemness of CD133+ CRC has never been reported. In this study, our objectives included: 1) to isolate pure CD133+ and CD133− cells from SW620 cell line; 2) to investigate the effect of LSD1 on the characteristics of CD133+ stem cancer cells by knocking down the target gene. Results suggested that the SW620 cell line had both CD133+ and CD133− subsets. The CD133+ subset exhibited more CSC-like characteristics compared with the CD133− subset with higher viability, colony formation rate, migration and invasion rate, resistance to anti-cancer drugs, and apoptosis in vitro. The CD133+ also induced faster tumor formation and larger tumors in vivo. In the LSD1-knockdown CD133+ cells, the CSC-like characteristics had been all weakened. We conclude that LSD1 was important for CSCs to maintain their “stemness” features, which could be a potential therapeutic target of CRC.

Bufalin reverses multidrug resistance by regulating stemness through the CD133/nuclear factor-κB/MDR1 pathway in colorectal cancer

Recent studies have shown that MDR could be induced by the high stemness of cancer cells. In a previous study, we found bufalin could reverse MDR and inhibit cancer cell stemness in colorectal cancer, but the relationship between them was unclear. Here we identified overexpressing CD133 increases levels of Akt/nuclear factor‐κB signaling mediators and MDR1, while increasing cell chemoresistance. Furthermore, bufalin reverses colorectal cancer MDR by regulating cancer cell stemness through the CD133/nuclear factor‐κB/MDR1 pathway in vitro and in vivo. Taken together, our results suggest that bufalin could be developed as a novel 2‐pronged drug that targets CD133 and MDR1 to eradicate MDR cells and could ultimately be combined with conventional chemotherapeutic agents to improve treatment outcomes for patients with colorectal cancer.

Targeting CD133 reverses drug-resistance via the AKT/NF-κB/MDR1 pathway in colorectal cancer

BACKGROUND

Recent studies have shown that multidrug resistance may be induced by the high stemness of cancer cells. Following prolonged chemotherapy, MDR protein 1 (MDR1) and CD133 increase in CRC, but the relationship between them is unclear.

METHODS

The relationship between MDR and CSC properties in CRC was determined via CCK-8 assay, apoptosis assay, DOX uptake and retention, immunohistochemistry, immunofluorescence and flow cytometry. The correlations between their expression levels were evaluated using Spearman's rank statistical test and the Mann-Whitney test. Furthermore, the effect of CD133 on the repression of the AKT/NF-κB/MDR1 signalling pathway was investigated in vitro and in vivo.

RESULTS

We found that CD133 increased with the emergence of drug-resistance phenotypes, and the high expression of MDR1/P-gp was consistently accompanied by positive expression of CD133 as demonstrated by the analysis of patient samples. Up- or downregulation of CD133 could regulate MDR via AKT/NF-κB/MDR1 signalling in CRC. A rescue experiment showed that the AKT/NF-κB signalling pathway is the main mechanism by which CD133 regulates MDR1/P-gp expression in CRC.

CONCLUSIONS

Taken together, our results suggest that targeting CD133 reverses drug resistance via the AKT/NF-κB/MDR1 pathway and that this pathway might serve as a potential therapeutic target to reverse MDR in CRC.

The role of mouse models in colorectal cancer research-The need and the importance of the orthotopic models

Colorectal cancer is a worldwide health burden, with high incidence and mortality, especially in the advanced stages of the disease. Preclinical models are very important and valuable to discover and validate early and specific biomarkers as well as new therapeutic targets. In order to accomplish that, the animal models must replicate the clinical evolution of the disease in all of its phases. In this article, we review the existent mouse models, with their strengths and weaknesses in the replication of human cancer disease progression, with major focus on orthotopic models.

Overexpression of a panel of cancer stem cell markers enhances the predictive capability of the progression and recurrence in the early stage cholangiocarcinoma

Background

Cancer recurrence is the important problem of cholangiocarcinoma (CCA) patients, lead to a very high mortality rate. Therefore, the identification of candidate markers to predict CCA recurrence is needed in order to effectively manage the disease. This study aims to examine the predictive value of cancer stem cell (CSC) markers on the progression and recurrence of CCA patients.

Methods

The expression of 6 putative CSC markers, cluster of differentiation 44 (CD44), CD44 variant 6 (CD44v6), CD44 variants 8-10 (CD44v8-10), cluster of differentiation 133 (CD133), epithelial cell adhesion molecule (EpCAM), and aldehyde dehydrogenase 1A1 (ALDH1A1), was investigated in 178 CCA tissue samples using immunohistochemistry (IHC) and analyzed with respect to clinicopathological data and patient outcome including recurrence-free survival (RFS) and overall survival (OS). The candidate CSC markers were also investigated in serum from CCA patients, and explored for their predictive ability on CCA recurrence.

Results

Elevated protein level of CD44 and positive expression of CD44v6 and CD44v8-10 were significantly associated with short RFS and OS, while high levels of ALDH1A1 were correlated with a favorable prognosis patient. The elevated CD44v6 level was also correlated with higher tumor staging, whereas a decreasing level of ALDH1A1 was correlated with lower tumor staging. The levels of CD44, CD44v6 and CD44v8-10 were also correlated and were associated with a poor outcome. Furthermore, soluble CD44, CD44v6, CD44v8-10 and EpCAM were significantly increased in the recurrence group for early stage CCA; they also correlated with high levels of the tumor marker CA19-9. Elevated levels of CD44, CD44v6, CD44v8-10 or EpCAM alone or in combination has the potential to predict CCA recurrence.

Conclusions

The overexpression of CD44, CD44v6, CD44v8-10 and EpCAM increases predictability of post-operative CCA recurrence. Moreover, the overexpression of the panel of CSC markers combined with CA19-9 could improve our predictive ability for tumor recurrence in early stage CCA patients. This result may be beneficial for the patients in order to predict the outcome after treatment and may be useful for clinical intervention in order to improve patient survival.

A. I. Colorectal cancer stem cells: a review of targeted drug delivery by gold nanoparticles

The proposed schematic mechanismviawhich 5-fluorouracil-loaded gold nanoparticles conjugated with CD133 antibody target colorectal cancer stem cells.

Immunohistochemical Expression of CD133 and LGR5 in Ulcerative Colitis-associated Colorectal Cancer and Dysplasia

BACKGROUND/AIM

Cluster of differentiation 133 (CD133) and leu cine-rich orphan G-protein-coupled receptor 5 (LGR5) are the most putative stem cell markers for colorectal cancer (CRC), and are associated with poor prognosis of patients with CRC. However, the role of CD133 and LGR5 in the inflammation-dysplasia-carcinoma sequence has not been fully elucidated. We examined the expression of CD133 and LGR5 in ulcerative colitis-associated CRC (UC-CRC; n=20) and UC-associated colorectal dysplasia (n=16) by immunohistochemistry.

RESULTS

The rate of CD133-positive cases in UC-CRC was significantly higher than that in dysplasia (p=0.026), but that of LGR5 expression was not. Moreover, LGR5 expression was significantly positively associated with p53 expression (p=0.03), whereas CD133 expression positively correlated with p53 expression, but not significantly (p=0.10).

CONCLUSION

CD133 may play an important role in tumor development in the context of the inflammation-dysplasia-carcinoma sequence. LGR5-positive cancer stem cells may play a critical role in the development of UC-CRC, particularly upon loss of p53 function.

Expression of CD133 as a cancer stem cell marker in invasive gastric carcinoma

Introduction

Gastric cancer is considered to be the fourth most common malignancy worldwide and the second cause of cancer deaths. Regarding the cancer stem cells (CSCs) theory, they are a small group of tumor cells with unrestricted self-renewal and differentiation abilities that help tumor formation. There is an interest in the utility of CD133 as a promising marker to detect the tumor stem cell population for a variety of solid malignancies including gastric cancer. Tumors that express stem cell markers such as CD133 are found to be more aggressive tumors with poor prognosis and high liability for recurrence. This study aimed to evaluate the immunohistochemical expression of CD133 in invasive gastric carcinoma and study the relation between CD133 immunohistochemical expression and different clinicopathological parameters.

Material and methods

77 cases of gastric carcinoma were collected from the surgical pathology unit at the Gastroenterology Center, Mansoura University, Egypt. CD133 expression in tumor tissue was evaluated by immunohistochemistry.

Results

CD133 expression positively correlated with tumor metastasis and recurrence. Multivariate analysis revealed CD133 positivity to be an independent prognostic factor for tumor recurrence (P = 0.03).

Conclusion

CD133 is a good marker that can predict tumor recurrence and metastasis in gastric carcinoma. Even though, studies regarding CSCs are still in their initial stages especially those related to CD133 in gastric cancer.

Detection of circulating colorectal cancer cells by a custom microfluid system before and after endoscopic metallic stent placement

Although the detection of circulating tumor cells (CTCs) should be crucial for future personalized medicine, no efficient and flexible methods have been established. The current study established a polymeric custom-made chip for capturing CTCs with a high efficiency and flexibility. As an example of clinical application, the effects of self-expandable metallic stent (SEMS) placement on the release of cancer cells into the blood of patients with colorectal cancer and bowel obstruction were analyzed. This was assessed as the placement of SEMS may cause mechanical damage and physical force to malignant tissue, increasing the risk of cancer cell release into the bloodstream. The present study examined the number of CTCs using a custom-made chip, before, at 24 h after and at 4 days after SEMS placement in patients with colorectal cancer. The results revealed that, among the 13 patients examined, the number of CTCs was increased in three cases at 24 h after SEMS placement. However, this increase was temporary. The number of CTCs also decreased at 4 days after stent placement in most cases. The CTC chip of the current study detected the number of CD133-positive cancer stem-like cells, which did not change, even in the patient whose total number of CTCs temporarily increased. The results indicated that this custom-made microfluid system can efficiently and flexibly detect CTCs, demonstrating its potential for obtaining information during the management of patients with cancer.

CD133: An emerging prognostic factor and therapeutic target in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of death worldwide. Recently, the role of cancer stem cells (CSCs) has been highlighted as a crucial emerging factor in chemoresistance, cancer relapse, and metastasis. CD133 is a surface marker of CSCs and has been argued to have prognostic and therapeutic values in CRC along with its related pathways such as Wnt, Notch, and hedgehog. Several studies have successfully applied targeted therapies against CD133 in CRC models namely bispecific antibodies (BiAbs) and anti-Wnt and notch pathways agents. These studies have yielded initial promising results in this regard. However, none of the therapeutics have been used in the clinical setting and their efficacy and adverse effects profile are yet to be elucidated. This review aims to gather the old and most recent data on the prognostic and therapeutic values of CD133 and CD133-targeted therapies in CRC.

CD44/CD133-Positive Colorectal Cancer Stem Cells are Sensitive to Trifluridine Exposure

Cancer stem cells (CSCs) are involved in metastatic colorectal cancer recurrence, but no effective therapy targeting these cells is currently available. Because trifluridine (FTD)/tipiracil therapy is used for refractory colorectal cancer, we sought to determine whether FTD is effective against CSC-like cells. CD44⁺CD133⁺ high-expressing and other populations of human DLD-1 colon cancer cells were separately isolated through fluorescence-activated cell sorting. The sphere-forming activity of each population and the anti-sphere-forming effects of FTD and fluorouracil (5-FU) on CD44⁺CD133⁺ cells were then measured. CD44⁺CD133⁺ DLD-1 cells formed substantially more spheres than other cells. Moreover, treating CD44⁺CD133⁺ DLD-1 cells with subtoxic concentrations of FTD (1 µM) inhibited sphere formation, and this was superior to the effect of subtoxic concentrations (1 µM) of 5-FU. The associated inhibition rates for FTD and 5-FU were 58.2% and 26.1%, respectively. Further, CD44⁺CD133⁺ DLD-1 cells expressed higher levels of thymidine kinase 1, which is responsible for FTD phosphorylation, than DLD-1 cells, and FTD was incorporated into the DNA of CD44⁺CD133⁺ DLD-1 cells. Thus, our data show that FTD treatment is effective against CSC-like cells and might be applied as CSC-targeting chemotherapy for tumor subtypes with high CD44 and CD133 expression.

Emerging insights into the biology of metastasis: A review article

Metastasis means the dissemination of the cancer cells from one organ to another which is not directly connected to the primary site. Metastasis has a crucial role in the prognosis of cancer patients. A few theories, different types of cell and several molecular pathways have been proposed to explain the mechanism of metastasis. In this work, the related articles in the limited period of time, 2000-mid -2018 were reviewed, through search in PubMed, Google Scholar and Scopus database. The articles published in the last two decades related to the biology of cancer metastasis were selected and the most important factors were discussed. Metastasis is critical factor to predict survival in patients with advanced cancer and prognosis determines the treatment plan. Many different cell types and various signaling pathways control the metastatic process. Metastasis is a multistep process. Many signaling pathways and molecules are involved in metastasis. Increasing knowledge about the mechanism of metastasis can help in finding the promising targets of cancer therapy.

Inhibitor of DNA binding 1 (Id1) mediates stemness of colorectal cancer cells through the Id1-c-Myc-PLAC8 axis via the Wnt/β-catenin and Shh signaling pathways

Background

Inhibitor of DNA binding 1 (Id1) is upregulated in multiple cancers, and Id1overexpression correlates with cancer aggressiveness and poor clinical outcomes in cancer patients. However, its roles in cancer stem-like cells (CSCs) and epithelial-mesenchymal transition (EMT) are still elusive.

Purpose

This study aimed to examine the role of Id1 on the mediation of CRC stemness and explore the underlying mechanisms.

Methods

Id1 and CD133 expression was detected by qPCR assay and immunohistochemistry (IHC) in normal mucosal and primary colorectal cancer (CRC) specimens. Id1 was stably knocked down (KD) in human CRC cell lines. Spheres forming assay and tumorigenic assay were performed to evaluate self-renewal capacity and tumor initiation. Expression of CSC- and EMT-related markers and TCF/LEF activity were assessed in HCT116 cells after Id1 KD.

Results

qPCR assay showed higher Id1 and CD133 expression in CRC specimens than in normal mucosal specimens (P<0.05). IHC detected high cytoplasmic Id1 expression in 35 CRC specimens (46.7%), and high CD133 expression in 22 CRC specimens (29.3%) and negative expression in 18 normal mucosal specimens. High Id1 expression positively correlated with poor differentiation (P=0.034), and CD133 expression correlated with T category in CRC patients (P=0.002). Spearman correlation analysis revealed a positive correlation between Id1 and CD133 expression in CRC patients (P<0.05). Id1 KD resulted in suppression of proliferation, cell-colony formation, self-renewal capability and CSC-like features in HCT116 cells, and impaired the tumor-initiating capability in CRC cells. In addition, Id1 maintained the stemness of CRC cells via the Id1-c-Myc-PLAC8 axis through activating the Wnt/β-catenin and Shh signaling pathways.

Conclusions

Id1 expression significantly correlates with CD133 expression in CRC patients, and Id1 KD impairs CSC-like capacity and reverses EMT traits, partially via the Wnt/β-catenin signaling. Id1 may be a promising therapeutic target against colon CSCs.

Regulatory mechanisms of microRNAs in colorectal cancer and colorectal cancer stem cells

Colorectal cancer (CRC) is one of the most lethal and hard-to-treat cancers in the world, which in its advanced stages, surgery and chemotherapy are the main common treatment approaches. The microRNAs (miRNAs), as novel markers for CRC detection, promote their regulatory effects via the 3'-untranslated binding region (3'-UTR) of target messenger RNA in posttranscriptional regulation of genes and also play a pivotal role in modulating resistance to chemotherapeutic agents. These small noncoding RNAs have also a critical role in CRC stem cells (CRCSCs) regulation, comprising self-renewal, differentiation, and tumorigenesis. Cancer stem cells (CSCs) are distinctive cell types inside a tumor tissue that are believed to derive from normal somatic stem cells. The CSCs have self-renewal abilities, angiogenesis, as well as specific surface markers expression characteristics. Furthermore, they are frequently criticized for tumor maintenance, treatment resistance, tumor development, and distant metastasis. In this review, we discuss the current understandings of CRCSCs and their environment with a focus on the role of miRNAs on the regulation of CSCs and their targeting application in CRC treatment.

An Fc-Optimized CD133 Antibody for Induction of Natural Killer Cell Reactivity against Colorectal Cancer

The introduction of monoclonal antibodies (mAbs) has largely improved treatment options for cancer patients. The ability of antitumor mAbs to elicit antibody-dependent cellular cytotoxicity (ADCC) contributes to a large extent to their therapeutic efficacy. Many efforts accordingly aim to improve this important function by engineering mAbs with Fc parts that display enhanced affinity to the Fc receptor CD16 expressed, e.g., on natural killer (NK) cells. Here we characterized the CD133 mAb 293C3-SDIE that contains an engineered Fc part modified by the amino acid exchanges S239D/I332E—that reportedly increase the affinity to CD16—with regard to its ability to induce NK reactivity against colorectal cancer (CRC). 293C3-SDIE was found to be a stable protein with favorable binding characteristics achieving saturating binding to CRC cells at concentrations of approximately 1 µg/mL. While not directly affecting CRC cell growth and viability, 293C3-SDIE potently induced NK cell activation, degranulation, secretion of Interferon-γ, as well as ADCC resulting in potent lysis of CRC cell lines. Based on the preclinical characterization presented in this study and the available data indicating that CD133 is broadly expressed in CRC and represents a negative prognostic marker, we conclude that 293C3-SDIE constitutes a promising therapeutic agent for the treatment of CRC and thus warrants clinical evaluation.

New emerging roles of CD133 in cancer stem cell: Signaling pathway and miRNA regulation

Cancer stem cells (CSC) are rare immortal cells within a tumor that are able to initiate tumor progression, development, and resistance. Advances studies show that, like normal stem cells, CSCs can be both self-renewed and given rise to many cell types, therefore form tumors. A number of cell surface markers, such as CD44, CD24, and CD133 are frequently used to identify CSCs. CD133, a transmembrane glycoprotein, either alone or in collaboration with other markers, has been mainly considered to identify CSCs from different solid tumors. However, the exactness of CD133 as a cancer stem cell biomarker has not been approved yet. The clinical importance of CD133 is as a CSC marker in many cancers. Also, it contributes to shorter survival, tumor progression, and tumor recurrence. The expression of CD133 is controlled by many extracellular or intracellular factors, such as tumor microenvironment, epigenetic factors, signaling pathways, and miRNAs. In this study, it was attempted to determine: 1) CD133 function; 2) the role of CD133 in cancer; 3) CD133 regulation; 4) the therapeutic role of CD133 in cancers.

Augmented CD133 expression in distal margin correlates with poor prognosis in colorectal cancer

Pathological assessment of excised tumour and surgical margins in colorectal cancer (CRC) play crucial role in prognosis after surgery. Molecular assessment of margins could be more sensitive and informative than conventional histopathological analysis. Considering this view, we evaluated the distal surgical margins for expression of cancer stem cell (CSC) markers. Cellular and molecular assessment of normal, tumour and distal margin tissues were performed by flow cytometry, real-time q-PCR and immuno-histochemical analysis for CRC patients after tumour excision. CRC patients were evaluated for expression of CSC markers in their normal, tumour and distal tissues. Flow cytometry assay revealed CD133 and CD44 enriched cells in distal margin and tumour compared to normal colorectal tissues, which was further confirmed by immunohistochemistry. Most importantly, immunohistochemistry also revealed the enrichment of CSC markers expression in pathologically negative distal margins. Patients with distal margin enriched for CD133 expression showed an increased recurrence rate and decreased disease-free survival. This study proposes that although distal margin seems to be tumour free in conventional histopathological analysis, it could harbour cells enriched for CSC markers. Further CD133 could be a promising molecule to be used in molecular pathology for disease prognosis after surgery in CRC patients.

Microfluidic Isolation of Circulating Tumor Cells and Cancer Stem-Like Cells from Patients with Pancreatic Ductal Adenocarcinoma

Background: Pancreatic ductal adenocarcinoma (PDAC) requires multimodal therapeutic approaches and disease monitoring for effective treatment. Liquid biopsy biomarkers, including circulating tumor cells (CTCs) and cancer stem-like cells (CSCs), hold promise for evaluating treatment response promptly and guiding therapeutic modifications.

Methods: From 24 patients with metastatic PDAC (stage IV, M1) undergoing active systemic treatment, we collected 78 blood samples at different time points for CTC and CSC isolation using a microfluidic platform functionalized with antibodies against a CTC biomarker, epithelial cell adhesion molecule (EpCAM), or a CSC biomarker, CD133. These isolated cells were further verified, via fluorescent staining and imaging, using cytokeratin (CK), CD45, and nucleic acid stain 4',6-diamidino-2-phenylindole (DAPI).

Results: The majority (84.4%) of patient blood samples were positive for CTCs (EpCAM⁺CK⁺CD45^-DAPI⁺) and 70.8% of patient blood samples were positive for CSCs (CD133⁺CK⁺CD45^-DAPI⁺), using the highest baseline value of healthy samples as threshold. The CTC subtypes (EpCAM⁺CK⁺CD45^-DAPI⁺CD133⁺ and EpCAM⁺CK⁺CD45^-DAPI⁺CD133^-) and CSC subtypes (CD133⁺CK⁺CD45^-DAPI⁺EpCAM⁺ and CD133⁺CK⁺CD45^-DAPI⁺EpCAM^-) were also analyzed using immunochemical methods. In several cases, CSCs exhibited cytokeratin expression that did not express EpCAM, indicating that they will not be detected using EpCAM-based isolation.

Conclusion: The microfluidic platform enabled the reliable isolation of CTCs and CSCs from PDAC patient samples, as well as their subtypes. Complementary assessment of both CTCs and CSCs appears advantageous to assess the profile of tumor progressing in some cases. This research has important implications for the application and interpretation of approved methods to detect CTCs.

Pretreatment detection of circulating and tissue CD133+ CD44+ cancer stem cells as a prognostic factor affecting the outcomes in Egyptian patients with colorectal cancer

Background and aim

Colorectal cancer is one of the most common malignant tumors worldwide. As CD133 and CD44 are notable markers of cancer stem cells (CSCs) identity, it is thought to be a predictive indicator for colorectal cancer. The aim of this study was to investigate the cell cycle state of CD133⁺ CD44⁺ and CD133⁻ CD44⁻cells, isolated from primary human colorectal tumors, and to assess the clinical impact of CD133⁺ CD44⁺ CSCs on patients’ outcome regarding disease-free survival (DFS) and overall survival (OS).

Materials and methods

Tissue samples were collected from 50 primary colorectal cancer patients. Flow cytometric analysis was performed to isolate tissue CD133⁺ CD44⁺ CSCs and CD133⁻ CD44⁻ tumor cells from primary colorectal cancer tissue to compare the cell cycle of both types of cells. Also circulating CSCs were assessed by flow cytometry.

Results

Higher percentage of tissue CD133⁺ CD44⁺ CSCs isolated from colorectal cancer patients was found in G0/G1 phase. However, tissue CD133⁻ CD44⁻ tumor cells were predominantly found in the S phase; there were significant negative correlations between tissue CD133⁺ CD44⁺ CSCs and DFS and OS (r=−0.470, P<0.001, respectively and r=−0.487, P<0.001, respectively), also significant negative correlations between tissue CSCs and DFS and OS (r=−0.548, P<0.001, respectively and r=−0.497, P<0.001, respectively). Only the pathological grade (P<0.004) and T stage (P<0.004) had a significant effect on circulating CSC counts.

Conclusion

Tissue CD133⁺ CD44⁺ CSCs were more quiescent than tissue CD133⁻ CD44⁻ tumor cells and both circulating CSCs and tissue CSCs were considered independent negative prognostic factors on OS and DFS.

Ping-Pong-Tumor and Host in Pancreatic Cancer Progression

Metastasis is the main cause of high pancreatic cancer (PaCa) mortality and trials dampening PaCa mortality rates are not satisfying. Tumor progression is driven by the crosstalk between tumor cells, predominantly cancer-initiating cells (CIC), and surrounding cells and tissues as well as distant organs, where tumor-derived extracellular vesicles (TEX) are of major importance. A strong stroma reaction, recruitment of immunosuppressive leukocytes, perineural invasion, and early spread toward the peritoneal cavity, liver, and lung are shared with several epithelial cell-derived cancer, but are most prominent in PaCa. Here, we report on the state of knowledge on the PaCIC markers Tspan8, alpha6beta4, CD44v6, CXCR4, LRP5/6, LRG5, claudin7, EpCAM, and CD133, which all, but at different steps, are engaged in the metastatic cascade, frequently via PaCIC-TEX. This includes the contribution of PaCIC markers to TEX biogenesis, targeting, and uptake. We then discuss PaCa-selective features, where feedback loops between stromal elements and tumor cells, including distorted transcription, signal transduction, and metabolic shifts, establish vicious circles. For the latter particularly pancreatic stellate cells (PSC) are responsible, furnishing PaCa to cope with poor angiogenesis-promoted hypoxia by metabolic shifts and direct nutrient transfer via vesicles. Furthermore, nerves including Schwann cells deliver a large range of tumor cell attracting factors and Schwann cells additionally support PaCa cell survival by signaling receptor binding. PSC, tumor-associated macrophages, and components of the dysplastic stroma contribute to perineural invasion with signaling pathway activation including the cholinergic system. Last, PaCa aggressiveness is strongly assisted by the immune system. Although rich in immune cells, only immunosuppressive cells and factors are recovered in proximity to tumor cells and hamper effector immune cells entering the tumor stroma. Besides a paucity of immunostimulatory factors and receptors, immunosuppressive cytokines, myeloid-derived suppressor cells, regulatory T-cells, and M2 macrophages as well as PSC actively inhibit effector cell activation. This accounts for NK cells of the non-adaptive and cytotoxic T-cells of the adaptive immune system. We anticipate further deciphering the molecular background of these recently unraveled intermingled phenomena may turn most lethal PaCa into a curatively treatable disease.

Impact of prenatal exercise on maternal harms, labour and delivery outcomes: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review of the relationships between prenatal exercise and maternal harms including labour/delivery outcomes.

DESIGN

Systematic review with random effects meta-analysis and meta-regression.

DATASOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if they were published in English, Spanish or French and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise, alone ["exercise-only"] or in combination with other intervention components [e.g., dietary; "exercise + co-intervention"]) and outcome (preterm/prelabour rupture of membranes, caesarean section, instrumental delivery, induction of labour, length of labour, vaginal tears, fatigue, injury, musculoskeletal trauma, maternal harms (author defined) and diastasis recti).

RESULTS

113 studies (n=52 858 women) were included. 'Moderate' quality evidence from exercise-only randomised controlled trials (RCTs) indicated a 24% reduction in the odds of instrumental delivery in women who exercised compared with women who did not (20 RCTs, n=3819; OR 0.76, 95% CI 0.63 to 0.92, I ²= 0 %). The remaining outcomes were not associated with exercise. Results from meta-regression did not identify a dose-response relationship between frequency, intensity, duration or volume of exercise and labour and delivery outcomes.

SUMMARY/CONCLUSIONS

Prenatal exercise reduced the odds of instrumental delivery in the general obstetrical population. There was no relationship between prenatal exercise and preterm/prelabour rupture of membranes, caesarean section, induction of labour, length of labour, vaginal tears, fatigue, injury, musculoskeletal trauma, maternal harms and diastasis recti.

Effects of prenatal exercise on fetal heart rate, umbilical and uterine blood flow: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis examining the influence of acute and chronic prenatal exercise on fetal heart rate (FHR) and umbilical and uterine blood flow metrics.

DESIGN

Systematic review with random-effects meta-analysis and meta-regression.

DATA SOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone ["exercise-only"] or in combination with other intervention components [eg, dietary; "exercise + co-intervention"]), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcomes (FHR, beats per minute (bpm); uterine and umbilical blood flow metrics (systolic:diastolic (S/D) ratio; Pulsatility Index (PI); Resistance Index (RI); blood flow, mL/min; and blood velocity, cm/s)).

RESULTS

'Very low' to 'moderate' quality evidence from 91 unique studies (n=4641 women) were included. Overall, FHR increased during (mean difference (MD)=6.35bpm; 95% CI 2.30 to 10.41, I²=95%, p=0.002) and following acute exercise (MD=4.05; 95% CI 2.98 to 5.12, I²=83%, p<0.00001). The incidence of fetal bradycardia was low at rest and unchanged with acute exercise. There were no significant changes in umbilical or uterine S/D, PI, RI, blood flow or blood velocity during or following acute exercise sessions. Chronic exercise decreased resting FHR and the umbilical artery S/D, PI and RI at rest.

CONCLUSION

Acute and chronic prenatal exercise do not adversely impact FHR or uteroplacental blood flow metrics.

The most reliable surface marker for the identification of colorectal cancer stem-like cells: A systematic review and meta-analysis

Several surface markers have been proposed for the identification and characterization of colorectal cancer stem-like cells (CR-CSLCs). However, their reliability in CR-CSLCs identification remains controversial. This study evaluated the correlation between all candidate surface marker's expression and CSLCs properties (tumorigenicity) through monitoring in vivo tumor incidence and final tumor volume. PubMed, Web of Science, and Scopus databases were systematically searched until November 2017. A total of 27 studies were found that met the inclusion criteria for cluster of differentiation 133 (CD133) and CD44 markers. Results indicated that either CD133 or CD44 positive cells caused about twofold increase in tumor volume compared with the negative cells (p < 0.05). In two groups of cells derived from primary tumors and cell lines, CD133 ⁺ cells had 25 and 1.45 times higher tumor incidence potential than CD133 ^- cells, respectively ( p < 0.05). Also, cohort evaluation showed that CD133 overexpression at protein level is a marker of poor overall survival in colorectal cancer (CRC) patients. While CD44 ⁺ cells displayed twofold tumorigenicity compared with the negative cells ( p < 0.05), combination of CD44 and CD133 showed about sevenfold tumorigenicity potential ( p < 0.05). In conclusion, the present meta-analysis suggests that CD133 is a robust biomarker to identify primary tumor CSLCs and can be proposed as a prognostic marker of CRC patient whereas it should be used with caution in cell lines. It seems to be more reliable to use CD133 in combination with CD44 as target biomarkers for the isolation of CR-CSLCs in both cell line and primary tumor cells populations.

An intestinal stem cell niche in Apc mutated neoplasia targetable by CtBP inhibition

C-terminal binding protein 2 (CtBP2) drives intestinal polyposis in the Apc^min mouse model of human Familial Adenomatous Polyposis. As CtBP2 is targetable by an inhibitor of its dehydrogenase domain, understanding CtBP2’s role in adenoma formation is necessary to optimize CtBP-targeted therapies in Apc mutated human neoplasia. Tumor initiating cell (TIC) populations were substantially decreased in Apc^minCtbp2^+/- intestinal epithelia. Moreover, normally nuclear Ctbp2 was mislocalized to the cytoplasm of intestinal crypt stem cells in Ctbp2^+/- mice, both Apc^min and wildtype, correlating with low/absent CD133 expression in those cells, and possibly explaining the lower burden of polyps in Apc^min Ctbp2^+/- mice. The CtBP inhibitor 4-chloro-hydroxyimino phenylpyruvate (4-Cl-HIPP) also robustly downregulated TIC populations and significantly decreased intestinal polyposis in Apc^min mice. We have therefore demonstrated a critical link between polyposis, intestinal TIC’s and Ctbp2 gene dosage or activity, supporting continued efforts targeting CtBP in the treatment or prevention of Apc mutated neoplasia.

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 role of CD133 in cancer: a concise review

Despite the abundant ongoing research efforts, cancer remains one of the most challenging diseases to treat globally. Due to the heterogenous nature of cancer, one of the major clinical challenges in therapeutic development is the cancer’s ability to develop resistance. It has been hypothesized that cancer stem cells are the cause for this resistance, and targeting them will lead to tumor regression. A pentaspan transmembrane glycoprotein, CD133 has been suggested to mark cancer stem cells in various tumor types, however, the accuracy of CD133 as a cancer stem cell biomarker has been highly controversial. There are numerous speculations for this, including differences in cell culture conditions, poor in vivo assays, and the inability of current antibodies to detect CD133 variants and deglycosylated epitopes. This review summarizes the most recent and relevant research regarding the controversies surrounding CD133 as a normal stem cell and cancer stem cell biomarker. Additionally, it aims to establish the overall clinical significance of CD133 in cancer. Recent clinical studies have shown that high expression of CD133 in tumors has been indicated as a prognostic marker of disease progression. As such, a spectrum of immunotherapeutic strategies have been developed to target these CD133^pos cells with the goal of translation into the clinic. This review compiles the current therapeutic strategies targeting CD133 and discusses their prognostic potential in various cancer subtypes.

Cancer stem cells as functional biomarkers

According to the American Association of Cancer Research (AACR), a Cancer Stem Cell is a cell within a tumor that possesses the capacity to self-renew and to cause the heterogeneous lineages of cancer cells that constitutes the tumor [1]. Cancer Stem Cells (CSCs) are involved in the metastatic process, in the resistance to therapeutic treatments of many types of human cancers and consequently in the onset of recurrences. Numerous translational studies have been conducted to understand CSC characteristics and evaluate association between CSC-related biomarkers and clinical outcomes. The CSC theory can explain also a tumor relapse after that a tumor has been completely surgically removed (R0 macroscopical zero residual resection) or after an apparently complete response to chemotherapy. CSCs, in fact, showed a marked ability to reduce intracellular accumulation of chemotherapic agents by active drug extrusion, increased chemoresistance and survival, as well as elevated membrane transporter activity. In addition, it is possible that these cancer stem cells may nest in the "secured" (niche) sites of our body, where they may remain undisturbed for a long time, even years, until a stimulus arrives to awaken them, causing the disease to resume. CSCs, in fact, are able to use a variety of cellular pathways to survive to anticancer treatments. More recently CSCs have been described in several solid tumors, expressing specific biomarkers. Another field of research should be focused on the realization of diagnostic instruments to follow up patients after R0 surgical resection or after a complete response for an early detection and management of relapse and metastasis.

ATP-binding cassette member B5 (ABCB5) promotes tumor cell invasiveness in human colorectal cancer

ABC member B5 (ABCB5) mediates multidrug resistance (MDR) in diverse malignancies and confers clinically relevant 5-fluorouracil resistance to CD133-expressing cancer stem cells in human colorectal cancer (CRC). Because of its recently identified roles in normal stem cell maintenance, we hypothesized that ABCB5 might also serve MDR-independent functions in CRC. Here, in a prospective clinical study of 142 CRC patients, we found that ABCB5 mRNA transcripts previously reported not to be significantly expressed in healthy peripheral blood mononuclear cells are significantly enriched in patient peripheral blood specimens compared with non-CRC controls and correlate with CRC disease progression. In human-to-mouse CRC tumor xenotransplantation models that exhibited circulating tumor mRNA, we observed that cancer-specific ABCB5 knockdown significantly reduced detection of these transcripts, suggesting that the knockdown inhibited tumor invasiveness. Mechanistically, this effect was associated with inhibition of expression and downstream signaling of AXL receptor tyrosine kinase (AXL), a proinvasive molecule herein shown to be produced by ABCB5-positive CRC cells. Importantly, rescue of AXL expression in ABCB5-knockdown CRC tumor cells restored tumor-specific transcript detection in the peripheral blood of xenograft recipients, indicating that ABCB5 regulates CRC invasiveness, at least in part, by enhancing AXL signaling. Our results implicate ABCB5 as a critical determinant of CRC invasiveness and suggest that ABCB5 blockade might represent a strategy in CRC therapy, even independently of ABCB5's function as an MDR mediator.

Colorectal cancer: genetic abnormalities, tumor progression, tumor heterogeneity, clonal evolution and tumor-initiating cells

Colon cancer is the third most common cancer worldwide. Most colorectal cancer occurrences are sporadic, not related to genetic predisposition or family history; however, 20-30% of patients with colorectal cancer have a family history of colorectal cancer and 5% of these tumors arise in the setting of a Mendelian inheritance syndrome. In many patients, the development of a colorectal cancer is preceded by a benign neoplastic lesion: either an adenomatous polyp or a serrated polyp. Studies carried out in the last years have characterized the main molecular alterations occurring in colorectal cancers, showing that the tumor of each patient displays from two to eight driver mutations. The ensemble of molecular studies, including gene expression studies, has led to two proposed classifications of colorectal cancers, with the identification of four/five non-overlapping groups. The homeostasis of the rapidly renewing intestinal epithelium is ensured by few stem cells present at the level of the base of intestinal crypts. Various experimental evidence suggests that colorectal cancers may derive from the malignant transformation of intestinal stem cells or of intestinal cells that acquire stem cell properties following malignant transformation. Colon cancer stem cells seem to be involved in tumor chemoresistance, radioresistance and relapse.

Metformin as an anti-cancer agent: actions and mechanisms targeting cancer stem cells

Metformin, a first line medication for type II diabetes, initially entered the spotlight as a promising anti-cancer agent due to epidemiologic reports that found reduced cancer risk and improved clinical outcomes in diabetic patients taking metformin. To uncover the anti-cancer mechanisms of metformin, preclinical studies determined that metformin impairs cellular metabolism and suppresses oncogenic signaling pathways, including receptor tyrosine kinase, PI3K/Akt, and mTOR pathways. Recently, the anti-cancer potential of metformin has gained increasing interest due to its inhibitory effects on cancer stem cells (CSCs), which are associated with tumor metastasis, drug resistance, and relapse. Studies using various cancer models, including breast, pancreatic, prostate, and colon, have demonstrated the potency of metformin in attenuating CSCs through the targeting of specific pathways involved in cell differentiation, renewal, metastasis, and metabolism. In this review, we provide a comprehensive overview of the anti-cancer actions and mechanisms of metformin, including the regulation of CSCs and related pathways. We also discuss the potential anti-cancer applications of metformin as mono- or combination therapies.

CD133 expression predicts post-operative recurrence in patients with colon cancer with peritoneal metastasis

Despite extensive research on cancer stem cells in colorectal cancer, the impact of stem cell markers on patient survival remains unclear, particularly in those with distant metastasis. In this study, we focused on colon cancer with peritoneal metastasis and investigated the association between the expression of CD133, aldehyde dehydrogenase-1 (ALDH1) and leucine-rich repeating G-protein coupled receptor-5 (Lgr5), and disease prognosis. Putative stem cell marker expression was immunohistochemically evaluated in samples from 142 primary tumours and 75 peritoneal nodules. The associations between the expression of these markers and clinicopathological characteristics, overall survival and disease-free survival were analysed. The expression of CD133, ALDH1 and Lgr5 was found to be positive in 55.6, 47.2 and 78.9% of the primary tumour samples, respectively. While their expression was not associated with overall survival, disease-free survival was significantly worse in the CD133‑negative group (36.1 vs. 13.7%, P=0.041). Multivariable analysis confirmed that a negative CD133 expression was an independent risk factor for a reduced disease-free survival (P=0.005). Furthermore, the benefit of systemic chemotherapy was significantly greater in the CD133-negative group (P=0.039). On the whole, our data indicated that patients with colon cancer with CD133-negative expression had a reduced disease-free survival. Thus, we propose that CD133 expression may be a useful clinical biomarker in the treatment of colon cancer with peritoneal metastasis.