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

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.

Leucine-rich repeat-containing G protein-coupled receptor 5 and CD133 expression is associated with tumor progression and resistance to preoperative chemoradiotherapy in low rectal cancer

Preoperative chemoradiotherapy has been performed as a standard therapy for advanced low rectal cancer. Cancer stem cells (CSCs) have been reported to contribute to resistance to treatment and patient prognosis. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) and cluster of differentiation (CD133) are putative markers for CSCs. However, their prognostic ability remains unknown, and evaluation of a single marker can be insufficient due to the heterogeneity of cancer. LGR5 and CD133 expression was immunohistochemically evaluated in surgical specimens of 56 patients who received curative resection following chemoradiotherapy for advanced low rectal cancer. In addition, the correlations between their expression levels, and clinicopathological features and patient prognosis were asessed. LGR5 expression was significantly correlated with lymphatic invasion, lymph node metastasis, and tumor node metastasic (TNM) stage. CD133 expression was significantly correlated with vascular invasion and the tumor regression grade. Combined expression was significantly correlated with lymphatic invasion, tumor regression grade and TNM stage, but not with overall, and disease-free survival. LGR5 and CD133 expressions may represent useful markers associated with tumor progression and resistance to chemoradiotherapy in patients with low rectal cancer. Furthermore, combined expression of these markers may be a more useful marker compared with the expression of each single marker.

Sciellin mediates mesenchymal-to-epithelial transition in colorectal cancer hepatic metastasis

Hepatic metastasis is the major cause of mortality in colorectal cancer (CRC) patients. Using proteomic analysis, we found sciellin (SCEL) to be specifically expressed in hepatic metastatic CRC cell lines. SCEL knockdown increased CRC cell migration and invasion, while overexpression had the opposite effect. SCEL knockdown also caused cancer cells to form more invasive structures within 3D cultures, increased the mesenchymal marker vimentin, and attenuated the epithelial marker E-cadherin. SCEL increased WNT signaling by activating β-catenin and its downstream target c-myc, and activated mesenchymal-to-epithelial transition (MET) through a SCEL-β-catenin-E-cadherin axis. SCEL showed higher expression in late stage primary CRC than in its hepatic metastatic counterpart. SCEL expression is dynamically modulated by TGF-β1 and hypoxia, revealing a plastic MET mechanism for tumor colonization. Intrahepatic injection in immunodeficient mice revealed that SCEL is necessary for metastatic CRC tumor growth in the liver. These results demonstrate that SCEL is a MET inducer dynamically regulated through the metastasis process. They suggest SCEL may be a useful therapeutic target for preventing or eliminating CRC hepatic metastasis.

Cytoplasmic expression of CD133 stemness marker is associated with tumor aggressiveness in clear cell renal cell carcinoma

Prominin-1 (CD133) is one of the most commonly used markers for cancer stem cells (CSCs), which are characterized by their ability for self-renewal and tumorigenicity. However, the clinical and prognostic significance of CSCs in renal cell carcinoma (RCC) remains unclear. The aim of this study was to investigate the expression patterns and prognostic significance of the cancer stem cell marker CD133 in different histological subtypes of RCC. CD133 expression was evaluated using immunohistochemistry in 193 well-defined renal tumor samples on tissue microarrays, including 136 (70.5%) clear cell renal cell carcinomas (CCRCCs), 26 (13.5%) papillary RCCs, and 31 (16.1%) chromophobe RCCs. The association between CD133 expression and clinicopathological features as well as the survival outcomes was determined. There was a statistically significant difference between CD133 expression among the different RCC subtypes. In CCRCC, higher cytoplasmic expression of CD133 was significantly associated with increase in grade, stage, microvascular invasion (MVI) and lymph node invasion (LNI), while no association was found with the membranous expression. Moreover, on multivariate analysis, TNM stage and nuclear grade were independent prognostic factors for overall survival (OS) in cytoplasmic expression. We showed that higher cytoplasmic CD133 expression was associated with more aggressive tumor behavior and more advanced disease in CCRCC but not in the other examined subtypes. Our results demonstrated that higher cytoplasmic CD133 expression is clinically significant in CCRCC and is associated with increased tumor aggressiveness and is useful for predicting cancer progression.

CD133 in brain tumor: the prognostic factor

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

The effects of the location of cancer stem cell marker CD133 on the prognosis of hepatocellular carcinoma patients

BACKGROUND

CD133 (prominin-1) is widely believed to be a cancer stem cell marker in various solid tumor types, and CD133 has been correlated with tumor-initiating capacity. Recently, the nuclear location of CD133 expression in tumors has been discussed, but hepatocellular carcinoma (HCC) has not been included in these discussions. The goal of this study was to investigate the location of CD133 expression in HCC and this location's potential value as a prognostic indicator of survival in patients with HCC.

METHODS

We enrolled 119 cancerous tissues and pair-matched adjacent normal liver tissue from HCC patients. These tissues were obtained immediately after operation, and tissue microarrays were subsequently constructed. The expression of CD133 was measured by immunohistochemistry (IHC), and the correlations between this expression and clinical characteristics and prognosis was estimated using statistical analysis.

RESULTS

The results showed that the CD133 protein expression levels of HCC in both the cytoplasm and nucleus were significantly higher than adjacent normal liver tissue. Kaplan-Meier survival and Cox regression analyses revealed that high CD133 expression in the cytoplasm was an independent predictor of poor prognosis for the overall survival (OS) and relapse-free survival (RFS) rates of HCC patients (P = 0.028 and P = 0.046, respectively). Surprisingly, high nuclear CD133 expression of HCC was an independent predictor of the good prognosis of the OS and RFS rates of HCC patients (P = 0.023 and P = 0.012, respectively).

CONCLUSIONS

The clinical evidence that revealed cytoplasmic CD133 expression was correlated with poor prognosis, while nuclear CD133 expression was significantly correlated with favorable prognosis.

Prognostic significance of CD133 and ezrin expression in colorectal carcinoma

Despite the improvement in the diagnostic and the therapeutic modalities, colorectal cancer (CRC) morbidity and mortality remain high in both the developed and the developing countries. So, we are in a need to recognize new efficient diagnostic and prognostic biomarkers of CRC. That may help in providing individualized targeted therapy for this lethal malignancy. In this study, we investigated the expression and the prognostic significance of CD133 and ezrin mRNA and protein by quantitative RT-PCR and immunohistochemical analysis in primary CRC cases and the surrounding normal colonic mucosa. The correlations between the expression of both markers and clinicopathological parameters were performed. Compared to control, the expression of CD133 and ezrin mRNA and protein in CRC were significantly up-regulated (P < 0.05). In addition, a strong positive correlation between both markers was found (r = 0.867, P < 0.001). Moreover, elevated levels of both markers were significantly associated with the stage, lymph node involvement, distant metastasis, and recurrence at both mRNA and protein levels (P < 0.05). In conclusion, there is a clinical significance of CD133 and ezrin as potential biomarkers for predicting CRC patients of aggressive behavior and poor prognosis. © 2017 IUBMB Life, 69(5):328-340, 2017.

Differential Gene Expression in Ductal Carcinoma In Situ of the Breast Based on ERBB2 Status

BACKGROUND

The molecular signature of ductal carcinoma in situ (DCIS) in the breast is not well understood. Erb-b2 receptor tyrosine kinase 2 (ERBB2 [formerly known as HER2/neu]) positivity in DCIS is predictive of coexistent early invasive breast carcinoma. The aim of this study is to identify the gene-expression signature profiles of estrogen receptor (ER)/progesterone receptor (PR)-positive, ERBB2, and triple-negative subtypes of DCIS.

METHODS

Based on ER, PR, and ERBB2 status, a total of 18 high nuclear grade DCIS cases with no evidence of invasive breast carcinoma were selected along with 6 non-neoplastic controls. The 3 study groups were defined as ER/PR-positive, ERBB2, and triple-negative subtypes.

RESULTS

A total of 49 genes were differentially expressed in the ERBB2 subtype compared with the ER/PR-positive and triple-negative groups. PROM1 was overexpressed in the ERBB2 subtype compared with ER/PR-positive and triple-negative subtypes. Other genes differentially expressed included TAOK1, AREG, AGR3, PEG10, and MMP9.

CONCLUSIONS

Our study identified unique gene signatures in ERBB2-positive DCIS, which may be associated with the development of invasive breast carcinoma. The results may enhance our understanding of the progression of breast cancer and become the basis for developing new predictive biomarkers and therapeutic targets for DCIS.

Expression of the stem cell marker CD133 is related to tumor development in colorectal carcinogenesis

BACKGROUND/OBJECTIVE

CD133 is currently considered the most robust surface marker for colorectal cancer stem cells. Two meta-analysis reports have suggested that CD133 expression is significantly associated with shorter survival, and CD133 may play an important role in the progression of colorectal cancer. However, the role of CD133 in colorectal adenoma has not been fully elucidated.

METHODS

We used immunohistochemistry to evaluate CD133 expression in 200 endoscopically resected colorectal polyps from 200 patients and 20 normal mucosae between January 1993 and December 1996.

RESULTS

CD133 staining was positive in 17.9% of the colorectal adenomas. Moreover, CD133 expression was associated with differentiation status (p = 0.003) and tumor size (p = 0.03).

CONCLUSION

CD133 might play an important role in tumor development.

[Molecular markers of cancer stem cells verified in vivo]

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

CD133 expression may be useful as a prognostic indicator in colorectal cancer, a tool for optimizing therapy and supportive evidence for the cancer stem cell hypothesis: a meta-analysis

We performed a meta-analysis of CD133-related clinical data to investigate the role of cancer stem cells (CSCs) in the clinical outcomes of colorectal cancer (CRC) patients, analyzing the effectiveness of various therapeutic strategies and examining the validity of the CSC hypothesis. For 28 studies (4546 patients), the relative risk (RR) to survival outcomes associated with CD133+ CRCs were calculated using STATA 12.0 software. Pooled results showed that CD133High patients had poor 5-year overall survival (RR 0.713, 95% CI 0·616-0·826) and 5-year disease free survival (RR 0·707, 95% CI 0·602-0·831). Both associations were consistently observed across different races, research techniques and therapeutic strategies. In a subgroup receiving adjuvant therapy, CD133Low patients achieved significantly better survival than CD133High patients. The findings suggest that CD133 could serve as a predictive marker of poor prognosis and treatment failure in CRC. CD133Low patients could benefit from adjuvant treatments, while CD133High patients should be given novel treatments besides adjuvant therapy. Our results also provide evidence in support of the CSC hypothesis.

Role of CD44(high)/CD133(high) HCT-116 cells in the tumorigenesis of colon cancer

This study aimed to explore cell surface biomarkers related to cancer stem cells (CSCs) and their role in the tumorigenesis of colon cancer. Various colon cancer cell lines were screened for CD133 and CD44 expression. CD44^high/CD133^high and CD44^low/CD133^low cells were separately isolated by Fluorescence-Activated Cell Sorting (FACS). The cell proliferation, colony formation, cell cycle characteristics, and tumorigenic properties in CD44^high/CD133^high and CD44^low/CD133^low cells were investigated through in vitro experiments and in vivo tumor xenograft models. The expression profiles of stem cell-related genes were examined by RT-PCR. With HCT-116 cells, flow cytometry analysis revealed that CD44^high/CD133^high cells had higher proliferation potency than CD44^low/CD133^low cells. Compared to CD44^low/CD133^low cells, CD44^high/CD133^high cells had more stem cell-related genes, and displayed increased tumorigenic ability. In summary, CD44^high/CD133^high cells isolated from HCT-116 cells harbor CSC properties that may be related to the tumor growth of colon cancer. These results suggest that CD44 and CD133 could be strong markers of colorectal cancer stem cells.

LGR5 and CD133 as prognostic and predictive markers for fluoropyrimidine-based adjuvant chemotherapy in colorectal cancer

BACKGROUND

Expression of leucine-rich-repeat-containing G-protein-coupled receptor 5 (LGR5) gene is associated with a metastatic phenotype and poor prognosis in colorectal cancer (CRC). CD133 expression is a putative cancer stem cell marker and a proposed prognostic marker in CRC, whereas the predictive value of CD133 expression for effect of adjuvant chemotherapy in CRC is unclear.

MATERIAL AND METHODS

For the study of LGR5 mRNA and CD133 expression, tissue microarrays from 409 primary CRC stage II and III tumors, where patients had been randomized to adjuvant chemotherapy or surgery only, were available. LGR5 mRNA and CD133 expression were assessed by in situ hybridization (ISH) and immunohistochemistry (IHC), respectively. LGR5 mRNA and CD133 expression as prognostic and predictive markers were evaluated by univariate and multivariate analyses.

RESULTS

For all CRC patients, positive LGR5 mRNA and CD133 expression were associated with classic adenocarcinoma histology type (p = 0.001 and p = 0.014, respectively). Positive LGR5 mRNA expression was also associated with smaller tumor diameter for CRC stage II (p = 0.005), but not for CRC stage III (p = 0.054). For CRC stage II, lack of LGR5 mRNA expression was associated with longer time to recurrence (TTR) in Kaplan-Meier (p = 0.045) and in multivariate Cox analysis (HR 0.27, 95% CI 0.08-0.95, p = 0.041). For colon cancer stage III patients, lack of CD133 expression was associated with better effect of adjuvant chemotherapy (p = 0.016) in Kaplan-Meier univariate analysis, but the interaction between CD133 and adjuvant chemotherapy was not statistically significant in multivariate analysis (HR 0.59, 95% CI 0.18-1.89, p = 0.374).

CONCLUSION

LGR5 mRNA expression is a prognostic factor for CRC stage II patients, whereas the value of CD133 expression as prognostic and predictive biomarker is inconclusive.

From Normal Skin to Squamous Cell Carcinoma: A Quest for Novel Biomarkers

Squamous cells carcinoma (SCC) is the second most frequent of the keratinocyte-derived malignancies after basal cell carcinoma and is associated with a significant psychosocial and economic burden for both the patient himself and society. Reported risk factors for the malignant transformation of keratinocytes and development of SCC include ultraviolet light exposure, followed by chronic scarring and inflammation, exposure to chemical compounds (arsenic, insecticides, and pesticides), and immune-suppression. Despite various available treatment methods and recent advances in noninvasive or minimal invasive diagnostic techniques, the risk recurrence and metastasis are far from being negligible, even in patients with negative histological margins and lymph nodes. Analyzing normal, dysplastic, and malignant keratinocyte proteome holds special promise for novel biomarker discovery in SCC that could be used in the future for early detection, risk assessment, tumor monitoring, and development of targeted therapeutic strategies.

Effect of MUC1/β-catenin interaction on the tumorigenic capacity of pancreatic CD133+ cells

Despite the fact that the biological function of cluster of differentiation (CD)133 remains unclear, this glycoprotein is currently used in the identification and isolation of tumor-initiating cells from certain malignant tumors, including pancreatic cancer. In the present study, the involvement of mucin 1 (MUC1) in the signaling pathways of a highly tumorigenic CD133+ cellular subpopulation sorted from the pancreatic cancer cell line HPAF-II was evaluated. The expression of MUC1-cytoplasmic domain (MUC1-CD) and oncogenic signaling transducers (epidermal growth factor receptor, protein kinase C delta, glycogen synthase kinase 3 beta and growth factor receptor-bound protein 2), as well as the association between MUC1 and β-catenin, were characterized in HPAF-II CD133+ and CD133low cell subpopulations and in tumor xenografts generated from these cells. Compared with HPAF CD133^low cells, HPAF-II CD133+ cancer cells exhibited increased tumorigenic potential in immunocompromised mice, which was associated with overexpression of MUC1 and with the accordingly altered expression profile of MUC1-associated signaling partners. Additionally, MUC1-CD/β-catenin interactions were increased both in the HPAF-II CD133+ cell subpopulation and derived tumor xenografts compared with HPAF CD133^low cells. These results suggest that, in comparison with HPAF CD133^low cells, CD133+ cells exhibit higher expression of MUC1, which contributes to their tumorigenic phenotype through increased interaction between MUC1-CD and β-catenin, which in turn modulates oncogenic signaling cascades.

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

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

Accumulation of ALDH1-positive cells after neoadjuvant chemotherapy predicts treatment resistance and prognosticates poor outcome in ovarian cancer

Although ovarian cancer is a highly chemosensitive disease, it is only infrequently cured. One of the major reasons lies in the presence of drug-resistant cancer stem-like cells, sufficient to fuel recurrence. We phenotyped cancer stem-like cells by flow cytometry and immunohistochemistry in 55 matched samples before and after taxane/platinum-based neoadjuvant chemotherapy. All used markers of stemness (ALDH1, CD24, CD117, CD133) isolated low frequencies of malignant cells. ALDH1 was the most valuable marker for tracking stemness in vivo. The enrichment of ALDH1 expression after treatment was associated with a poor response to chemotherapy, with platinum resistance and independently prognosticated unfavorable outcome. Our results suggest that increased ALDH1 expression after treatment identifies patients with aggressive tumor phenotypes.

Characterization of sphere-forming HCT116 clones by whole RNA sequencing

PURPOSE

To determine CD133(+) cells defined as cancer stem cells (CSCs) in colon cancer, we examined whether CD133(+) clones in HCT116 demonstrate known features of CSCs like sphere-forming ability, chemodrug-resistance, and metastatic potential.

METHODS

Magnetic cell isolation and cell separation demonstrated that <1% of HCT116 cells expressed CD133, with the remaining cells being CD133(-) clones. In colon cancer cells, radioresistance is also considered a CSC characteristic. We performed clonogenic assay using 0.4 Gy γ-irradiation.

RESULTS

Interestingly, there were no differences between HCT116 parental and HCT116 CD133(+) clones when the cells comprised 0.5% of the total cells, and CD133(-) clone demonstrated radiosensitive changes compared with parental and CD133(+) clones. Comparing gene expression profiles between sphere-forming and nonforming culture conditions of HCT116 subclones by whole RNA sequencing failed to obtain specific genes expressed in CD133(+) clones.

CONCLUSION

Despite no differences of gene expression profiles in monolayer attached culture conditions of each clone, sphere-forming conditions of whole HCT116 subclones, parental, CD133(+), and CD133(-) increased 1,761 coding genes and downregulated 1,384 genes related to CSCs self-renewal and survival. Thus, spheroid cultures of HCT116 cells could be useful to expand colorectal CSCs rather than clonal expansion depending on CD133 expressions.

[Cancer stem cell markers and their prognostic value]

Based on an analysis of a large number of sources of literature, the paper gives general information on the markers for cancer stem cells (CSCs), which allow the detection of this rare cell subpopulation, on the possibilities of estimating their immunohistochemical or immunofluorescent expression in tumors, and on the prognostic and predictive values of these molecules. For their detection, investigators generally use definite molecules, the so-called markers of CSCs, among which there are CD44, CD133, CD24, aldehyde dehydrogenase, and others. The expression of these molecules in the tumor tissue obtained from patients affects survival rates and permits the prediction of a response to therapy. A better insight into the immunophenotype of CSCs, the role of CSC markers in retaining the special properties of this call population, and the clinical significance of the expression of CSC markers will be able to elaborate new approaches to therapy for malignancies.

CD133 Expression at the Metastatic Site Predicts Patients' Outcome in Colorectal Cancer with Synchronous Liver Metastasis

BACKGROUND

CD133 is a transmembrane protein that is proposed to be a stem cell marker of colorectal cancer (CRC); however, the correlation between CD133 expression and survival of CRC patients with liver metastasis has not been fully examined.

METHODS

CD133 expression was evaluated immunohistochemically, both in primary tumors and synchronous liver metastases of 88 consecutive CRC patients, as well as recurrent lesions in the remnant liver of 27 of these 88 patients. The relationship between CD133 expression and clinicopathological characteristics, recurrence-free survival, and overall survival (OS) was analyzed.

RESULTS

CD133 expression in liver metastases (mCD133) was detected in 50 of 88 patients (56.8 %), and had significant correlation with CD133 expression in primary lesions (pCD133) (p < 0.001). CD133 expression in liver recurrent lesions (recCD133) also had a significant correlation with mCD133 (p < 0.001). mCD133+ patients had significantly longer disease-free survival (p = 0.043) and OS (p = 0.014) than mCD133- patients. In addition, mCD133+ patients had a significantly lower rate of extrahepatic recurrence (p < 0.001).

CONCLUSIONS

Patients without CD133 expression in liver metastasis had significantly shorter survival, perhaps because mCD133- patients had a significantly higher rate of extrahepatic recurrence.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

5-fluorouracil resistant colon cancer cells are addicted to OXPHOS to survive and enhance stem-like traits

Despite marked tumor shrinkage after 5-FU treatment, the frequency of colon cancer relapse indicates that a fraction of tumor cells survives treatment causing tumor recurrence. The majority of cancer cells divert metabolites into anabolic pathways through Warburg behavior giving an advantage in terms of tumor growth. Here, we report that treatment of colon cancer cell with 5-FU selects for cells with mesenchymal stem-like properties that undergo a metabolic reprogramming resulting in addiction to OXPHOS to meet energy demands. 5-FU treatment-resistant cells show a de novo expression of pyruvate kinase M1 (PKM1) and repression of PKM2, correlating with repression of the pentose phosphate pathway, decrease in NADPH level and in antioxidant defenses, promoting PKM2 oxidation and acquisition of stem-like phenotype. Response to 5-FU in a xenotransplantation model of human colon cancer confirms activation of mitochondrial function. Combined treatment with 5-FU and a pharmacological inhibitor of OXPHOS abolished the spherogenic potential of colon cancer cells and diminished the expression of stem-like markers. These findings suggest that inhibition of OXPHOS in combination with 5-FU is a rational combination strategy to achieve durable treatment response in colon cancer.

Minnelide effectively eliminates CD133(+) side population in pancreatic cancer

Background

Pancreatic Ductal Adenocarcinoma (PDAC) is a devastating disease hallmarked by limited patient survival. Resistance to chemotherapy, a major cause of treatment failure in PDAC patients, is often attributed to Cancer Stem Cells (CSCs). Pancreatic CSCs are a small subset of quiescent cells within a tumor represented by surface markers like CD133. These cells are responsible not only for tumor recurrence, but also poor prognosis based on their “stem-like” characteristics. At present, conventional therapy is directed towards rapidly dividing PDAC cells and thus fails to target the CSC population.

Methods

MIA PaCa-2, S2-013 and AsPC-1 were treated with 12.5 nM triptolide (12 T cells) for 7 days. The surviving cells were recovered briefly in drug-free growth media and then transferred to Cancer Stem cell Media (CSM). As a control, untreated cells were also transferred to CSM media (CSM). The 12 T and CSM cells were tested for stemness properties using RNA and protein markers. Low numbers of CSM and 12 T cells were implanted subcutaneously in athymic nude mice to study their tumorigenic potential. 12 T and CSM cells were sorted for CD133 expression and assayed for their colony forming ability and sphere forming ability. Invasiveness of 12 T cells, CSM and MIA PaCa-2 were compared using Boyden chamber assays.

Results

Treated 12 T cells displayed increased expression of the surface marker CD133 and the drug transporter ABCG2 compared to untreated cells (CSM cells). Both 12 T and CSM cells formed subcutaneous tumors in mice confirming their tumor-initiating properties. When tested for invasion, 12 T cells had increased invasiveness compared to CSM cells. CD133⁺ cells in both CSM and 12 T showed greater colony and sphere forming ability compared to CD133⁻ cells from each group. Consistent with these data, when injected subcutaneously in mice, CD133⁻ cells from CSM or 12 T did not form any tumors whereas CD133⁺ cells from both groups showed tumor formation at a very low cell number. Despite pre-exposure to triptolide in 12 T CD133⁺ cells, treatment of tumors formed by these cells with Minnelide, a triptolide pro-drug, showed significant tumor regression.

Conclusion

Our results indicated that triptolide enhanced and enriched the “stemness” in the PDAC cell lines at a low dose of 12.5 nM, but also resulted in the regression of tumors derived from these cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0470-6) contains supplementary material, which is available to authorized users.

Prognostic value of CD44 expression in renal cell carcinoma: a systematic review and meta-analysis

CD44 is a marker of cancer stem-like cells in renal cell carcinoma (RCC). However, the prognostic value of CD44 in RCC remains controversial. This study evaluated the correlation of CD44 expression with the clinicopathological features of RCC through a meta-analysis. We systematically searched PubMed, ISI Web of Science and Embase for relevant studies until February 2015. We collected and analysed data on clinical stage, Fuhrman grade, microvascular invasion, recurrence, five-year overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS). Twenty studies involving 1672 patients satisfied the inclusion criteria. Results showed that high CD44 expression in RCC was a poor prognostic marker for five-year OS (RR = 0.69, 95% CI 0.60–0.78) in a fixed-effects model and for five-year DSS (RR = 0.46, 95% CI 0.27–0.80) and five-year DFS (RR = 0.63, 95% CI 0.43–0.93) in a random-effects model. CD44 expression also correlated with Furhman grade (RR = 0.61, 95% CI 0.48–0.77), tumour recurrence (RR = 7.42, 95% CI 3.74–14.70) and MVI (Microvascular invasion) (RR = 3.63, 95% CI 1.97–6.71). This meta-analysis suggests that CD44 is a prognostic marker in RCC. High CD44 expression correlates with high Fuhrman grade, recurrence, MVI and poor prognosis.

Colorectal cancer stem cells: from the crypt to the clinic

Since their first discovery, investigations of colorectal cancer stem cells (CSCs) have revealed some unexpected properties, including a high degree of heterogeneity and plasticity. By exploiting a combination of genetic, epigenetic, and microenvironmental factors, colorectal CSCs metastasize, resist chemotherapy, and continually adapt to a changing microenvironment, representing a formidable challenge to cancer eradication. Here, we review the current understanding of colorectal CSCs, including their origin, relationship to stem cells of the intestine, phenotypic characterization, and underlying regulatory mechanisms. We also discuss limitations to current preclinical models of colorectal cancer and how understanding CSC plasticity can improve the development of clinical strategies.

Expression of stemness genes in primary breast cancer tissues: the role of SOX2 as a prognostic marker for detection of early recurrence

The events leading to breast cancer (BC) progression or recurrence are not completely understood and new prognostic markers aiming at identifying high risk-patients and to develop suitable therapy are highly demanded. Experimental evidences found in cancer cells a deregulated expression of some genes involved in governance of stem cell properties and demonstrated a relationship between stemness genes overexpression and poorly differentiated BC subtypes. In the present study 140 primary invasive BC specimens were collected. The expression profiles of 13 genes belonging to the OCT3/SOX2/NANOG/KLF4 core circuitry by RT-PCR were analyzed and any correlation between their expression and the BC clinic-pathological features (CPfs) and prognosis was investigated. In our cohort (117 samples), NANOG, GDF3 and SOX2 significantly correlated with grade 2, Nodes negative status and higher KI67 proliferation index, respectively (p=0.019, p=0.029, p= 0.035). According to multivariate analysis, SOX2 expression resulted independently associated with increased risk of recurrence (HR= 2,99; p= p=0,004) as well as Nodes status (HR=2,44; p=0,009) and T-size >1 (HR=1,77; p=0,035). Our study provides further proof of the suitable use of stemness genes in BC management. Interestingly, a prognostic role of SOX2, which seems to be a suitable marker of early recurrence irrespective of other clinicopathological features.

Concise Review: Targeting Cancer Stem Cells Using Immunologic Approaches

Cancer stem cells (CSCs) represent a small subset of tumor cells which have the ability to self-renew and generate the diverse cells that comprise the tumor bulk. They are responsible for local tumor recurrence and distant metastasis. However, they are resistant to conventional radiotherapy and chemotherapy. Novel immunotherapeutic strategies that specifically target CSCs may improve the efficacy of cancer therapy. To immunologically target CSC phenotypes, innate immune responses to CSCs have been reported using Natural killer cells and γδ T cells. To target CSC specifically, in vitro CSC-primed T cells have been successfully generated and shown targeting of CSCs in vivo after adoptive transfer. Recently, CSC-based dendritic cell vaccine has demonstrated significant induction of anti-CSC immunity both in vivo in immunocompetent hosts and in vitro as evident by CSC reactivity of CSC vaccine-primed antibodies and T cells. In addition, identification of specific antigens or genetic alterations in CSCs may provide more specific targets for immunotherapy. ALDH, CD44, CD133, and HER2 have served as markers to isolate CSCs from a number of tumor types in animal models and human tumors. They might serve as useful targets for CSC immunotherapy. Finally, since CSCs are regulated by interactions with the CSC niche, these interactions may serve as additional targets for CSC immunotherapy. Targeting the tumor microenvironment, such as interrupting the immune cell, for example, myeloid-derived suppressor cells, and cytokines, for example, IL-6 and IL-8, as well as the immune checkpoint (PD1/PDL1, etc.) may provide additional novel strategies to enhance the immunological targeting of CSCs.

Clinicopathological significance and prognostic value of the expression of the cancer stem cell marker CD133 in hepatocellular carcinoma: a meta-analysis

To conduct a meta-analysis to assess the association between CD133 expression and clinicopathological significance and prognostic value in hepatocellular carcinoma patients. Studies were identified via an electronic comprehensive literature search through the Pubmed, Chinese CNKI, and Wanfang databases. This meta-analysis was performed using Stata statistical software version 12.0. The outcomes included various clinicopathological and survival parameters (P < 0.05 was consider to indicate a statistical significance). A total of 21 studies comprising 2592 patients were included in this meta-analysis. CD133 overexpression was significantly associated with a series of clinicopathological parameters, such as low tumor differentiation (pooled odds ratio (OR) = 2.26, 95% CI: 1.59-3.21, P < 0.00001), advanced tumor stage (pooled OR = 2.17, 95% CI: 1.70-2.77, P < 0.00001), vascular invasion (pooled OR = 2.06, 95% CI: 1.25-3.39, P = 0.005), and vascular thrombosis (pooled OR = 1.47, 95% CI: 1.08-1.99, P = 0.015). However, CD133 expression was not correlated with hepatitis, cirrhosis, α-fetoprotein level, tumor number, tumor size, encapsulation, or metastasis. Regarding survival outcome, CD133 overexpression was significantly correlated with poor overall survival (pooled hazard ratio (HR) = 2.01, 95% CI: 1.45-2.80, P = 0.00002) and poor disease-free survival (pooled HR = 1.82, 95% CI: 1.45-2.29, P < 0.00001). This meta-analysis indicated that CD133 overexpression is significantly associated with clinicopathological factors and poorer survival outcome.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Characterization and propagation of tumor initiating cells derived from colorectal liver metastases: trials, tribulations and a cautionary note

Tumor initiating cells (TIC) are increasingly being put forward as a potential target for intervention within colorectal cancer. Whilst characterisation and outgrowth of these cells has been extensively undertaken in primary colorectal cancers, few data are available describing characteristics within the metastatic setting. Tissue was obtained from patients undergoing surgical resection for colorectal liver metastases, and processed into single cell suspension for assessment. Tumor initiating cells from liver metastases were characterised using combinations of EPCAM, Aldehyde dehydrogenase activity, CD133 and CD26. CD133 expression was significantly lower in patients who had received chemotherapy, but this was accounted for by a decrease observed in the male patient cohort only. ALDHhigh populations were rare (0.4 and 0.3% for EPCAM+/ALDHhigh/CD133- and EPCAM+/ALDHhigh/CD133+ populations respectively) and below the limits of detection in 28% of samples. Spheroid outgrowth of metastatic tumor cells across all samples could not be readily achieved using standard spheroid-formation techniques, thus requiring further method validation to reliably propagate cells from the majority of tissues. Spheroid formation was not enhanced using additional growth factors or fibroblast co-culture, but once cells were passaged through NOD-SCID mice, spheroid formation was observed in 82% samples, accompanied by a significant increase in CD26. Order of spheroid forming ability was ALDHhigh>CD133>CD26. Samples sorted by these markers each had the ability to reform ALDHhigh, CD133 and CD26 positive populations to a similar extent, suggestive of a high degree of plasticity for each population. Ex vivo TIC models are increasingly being utilised to assess efficacy of therapeutic interventions. It is therefore essential that such investigations use well-characterised models that are able to sustain TIC populations across a large patient cohort in order that the inherent heterogeneity observed in cancer populations is maintained.

Prognostic Value of Cancer Stem Cell Marker ALDH1 Expression in Colorectal Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

Many studies have indicated the prognostic and clinicopathological value of aldehyde dehydrogenase 1 (ALDH1) in colorectal cancer (CRC) patients still remains controversial. Thus we performed this study to clarify the relationship between high ALDH1 expression in CRC and its impact on survival and clinicopathological features.

METHODS

Publications for relevant studies in Pubmed, the Cochrane Library, Embase, and China National Knowledge Infrastructure (CNKI) through April 2015 were identified. Only articles describing ALDH1 antigen with immunohistochemistry in CRC were included. The software RevMan 5.1 was used to analyze the outcomes, including 5-year overall survival (OS), disease-free survival (DFS) and clinicopathological features.

RESULTS

9 studies with 1203 patients satisfying the criteria were included. The overall rate of high ALDH1 expression was 46.5% by immunohistochemical staining. High ALDH1 expression as an independent prognostic factor was significantly associated with the 5-year OS and DFS (OR = 0.42, 95%CI: 0.26-0.68, P = 0.0004; OR = 0.38, 95%CI: 0.24-0.59, P < 0.0001, respectively). High ALDH1 expression was highly correlated with the tumor (T) stage (T3 + T4 vs. T1 + T2; OR = 2.16, 95%CI: 1.09-4.28, P = 0.03), lymph node (N) stage (N1 + N2 vs. N0; OR = 1.8; 95%CI: 1.17-2.79, P = 0.008), and tumor differentiation (G3 vs. G1 + G2; OR = 1.88; 95%CI: 1.07-3.30, P = 0.03). However, high ALDH1 expression was not significantly correlated with the patient age (>60 years old vs. <60 years old; OR = 1.11, 95%CI: 0.63-1.94, P = 0.72).

CONCLUSIONS

High ALDH1 expression indicates a poor prognosis in CRC patients. Moreover, high ALDH1 expression correlates with the T stage, N stage, and tumor differentiation, but not with age.

CTC enumeration and characterization: moving toward personalized medicine

The primary cause of tumor-related death in breast cancer (BC) is still represented by distant metastasization. The dissemination of tumor cells from the primary tumor to distant sites through bloodstream cannot be early detected by standard imaging methods. The enumeration of circulating tumor cells (CTCs) represents an effective prognostic and predictive biomarker, which is able to monitor efficacy of adjuvant therapies, detect early development of (micro)metastases and at last, assess therapeutic responses of advanced disease earlier than traditional imaging methods. Moreover, since repeated tissue biopsies are invasive, costly and not always feasible, the assessment of tumor characteristics on CTCs, by a peripheral blood sample as a 'liquid biopsy', represents an attractive opportunity. The implementation of molecular and genomic characterization of CTCs could contribute to improve the treatment selection and thus, to move toward more personalized treatments. This review describes the current state of the art on CTC detection strategies, the evidence to demonstrate their clinical validity, and their potential impact for both future clinical trial design and, decision-making process in our daily practice.

CD133-positive tumor cell content is a predictor of early recurrence in colorectal cancer

BACKGROUND

The aims of this study were to demonstrate the tumorigenicity of CD133+ colon cancer cells in vitro, analyze the correlations between spheroid formation and clinicopathologic variables, and screen for overexpressed genes in CD133+ colon cancer stem cells. Moreover, the aim of this study was to establish a living tumor tissue bank using surgically resected specimens.

METHODS

Using LoVo cell line, we isolated CD133+ cells and performed clonogenic assay and animal experiment to test tumorigenicity of CD133+ cells. Twenty-nine surgical samples were freshly collected from 27 patients who received curative or palliative surgery, and the samples were mechanically and enzymatically dissociated into single cells.

RESULTS

We confirmed the enhanced tumorigenicity of CD133+ cells isolated from LoVo cell line both in vitro and in vivo. Of these 29 samples, 8 (28%) contained >3% CD133+ cells. Sphere formation was significantly higher in samples from patients with lymphatic invasion than in those without lymphatic invasion [54.5% (6/11) vs. 12.5% (2/16); P=0.033] and in samples containing >3% of CD133+ cells than in those containing ≤3% of CD133+ cells [36.4% (4/11) vs. 0% (0/16); P=0.019].

CONCLUSIONS

These findings indicate that CD133 is a valid marker for identifying cancer stem cells from fresh surgically resected colorectal cancer tissues. Furthermore, we successfully established a living tumor tissue bank using surgically resected colorectal tissues with a viability of >70%.

Prom1 function in development, intestinal inflammation, and intestinal tumorigenesis

Prom1/CD133 has been identified in colorectal, hepatocellular, and pancreatic cancer as a cancer stem cell marker and has been used as such to predict colon cancer recurrence in humans. Its potential molecular function as well as its role as a marker of intestinal regeneration is still not fully known. We evaluated the role of Prom1 in intestinal regeneration in inflammatory bowel disease (IBD), determined the function of Prom1, and characterized the effect of a lack of Prom1 on intestinal tumor formation in animal models. Our results suggest that Apc mutations lead to an increase in Prom1 expressing cells in the intestinal crypt stem cell compartment and in early intestinal adenomas. Also, Prom1 knockout mice are more susceptible to intestinal tumor formation. We conclude that Prom1 likely plays a role in regulating intestinal homeostasis and that these results clearly illustrate the role of Prom1 in intestinal regeneration. We further conclude that Prom1 may provide a novel therapeutic target for patients with gastrointestinal conditions such as IBD, short bowel syndrome, and colorectal cancer.

Comparison of putative circulating cancer stem cell detection between the hepatic portal system and peripheral blood in colorectal cancer patients

PURPOSE

The present pilot study was conducted to detect putative cancer stem cell (CSC) from the hepatic portal system and peripheral blood in the colorectal cancer patients and to compare them to healthy donor and diverticulitis patients.

METHODS

Laboratory study was performed to identify the expression of cell surface markers, epithelial cell adhesion molecule (EpCAM), cytokeratin (CK) 18, CK20, CD44, and CD133, on several colon cancer cell lines. Clinical pilot study was conducted to detect putative circulating CSC as EpCAM(+)CD133(+) cell in colorectal cancer (n = 10), diverticulitis (n = 5), and four healthy donors, by using flow cytometry. Blood was drawn from the hepatic portal system and peripheral vein.

RESULTS

On laboratory study, EpCAM was expressed in whole colon cancer cell lines, and CD44 and CD133 were simultaneously expressed in 50% of the cell lines with stemness phenotype, but CK18 and CK20 were not expressed in most of the cell lines. On clinical study, the mean EpCAM(+)CD133(+) cell counts of 11.6/10(5) in the hepatic portal system were somewhat lower than 15.4/10(5) in peripheral vein (P = 0.241). As for diverticulitis patients, EpCAM(+)CD133(+) cells were also detected to have steeper dropped to near zero, after the surgery.

CONCLUSION

The numbers of putative CSC were not statistically different between the detection sites of the portal vein and peripheral vein in the colon cancer patients. Therefore, we may not have benefitted by getting the cells from the hepatic portal system. In addition, the CD133(+)EpCAM(+) cells in the colon cancer patients might contain normal stem cells from cancer inflammation similar to diverticulitis.

Preoperative low dose NSAID treatment influences the genes for stemness, growth, invasion and metastasis in colorectal cancer

Preclinical data, and an increasing list of clinical investigations, show anti-inflammatory agents to favourably influence the biology of colorectal tumor. We have earlier reported on re-expression of activated immune cells after three days preoperative treatment of patients with colorectal carcinoma, randomized to receive oral NSAID (indomethacin or celebrex). Antisecretory prophylaxis (esomeprasol) was provided to all patients and served as sham treatment. Concomittant to MHC locus activation, Prominin1/CD133, a marker associated with stemness and poor prognosis in several solid tumors, was downregulated. The aim of the present study was to evaluate expression of additional regulators belonging to the stem cell niche, OCT4, SOX2 and BMP7, as well as some microRNAs, reported to act as tumor suppressors or oncomiRs. Peroperative tumor biopsies were analyzed by microarrays, quantitative real-time PCR and immunohistochemistry (IHC). The stem cell master regulator SOX2 was increased by NSAIDs (p<0.01), as well as the tumor suppressor miR-630 (p<0.01), while BMP7, a marker for poor prognosis in CRC, was downregulated by NSAID (indomethacin, p<0.02). The upregulation of SOX2, but not of its heterodimer binding partner OCT4, could imply a negative feed-back loop, with a switch‑off for stemness preservation of tumor cells. This is supported by the overall evaluation of gene expression profiles with subsequent events, indicating less aggressive tumors following NSAID treatment.

Colorectal cancers mimic structural organization of normal colonic crypts

Colonic crypts are stereotypical structures with distinct stem cell, proliferating, and differentiating compartments. Colorectal cancers derive from colonic crypt epithelia but, in contrast, form morphologically disarrayed glands. In this study, we investigated to which extent colorectal cancers phenocopy colonic crypt architecture and thus preserve structural organization of the normal intestinal epithelium. A subset of colon cancers showed crypt-like compartments with high WNT activity and nuclear β-Catenin at the leading tumor edge, adjacent proliferation, and enhanced Cytokeratin 20 expression in most differentiated tumor epithelia of the tumor center. This architecture strongly depended on growth conditions, and was fully reproducible in mouse xenografts of cultured and primary colon cancer cells. Full crypt-like organization was associated with low tumor grade and was an independent prognostic marker of better survival in a collection of 221 colorectal cancers. Our findings suggest that full activation of preserved intestinal morphogenetic programs in colon cancer requires in vivo growth environments. Furthermore, crypt-like architecture was linked with less aggressive tumor biology, and may be useful to improve current colon cancer grading schemes.

Stem cells, colorectal cancer and cancer stem cell markers correlations

: The idea of stem cells as being progenitors of cancer was initially controversial, but later supported by research in the field of leukemia and solid tumors. Afterwards, it was established that genetic abnormalities can affect the stem and progenitor cells, leading to uncontrolled replication and deregulated differentiation. These alterations will cause the changeover to cancerous stem cells (CSC) having two main characteristics: tumor initiation and maintenance. This review will focus on the colorectal cancer stem cell (CR-CSCs) theory which provides a better understanding of different tumor processes: initiation, aggressive growth, recurrence, treatment resistance and metastasis. A search in PubMed/Medline was performed using the following keywords: colorectal cancer stem cells (CR-CSCs), colorectal neoplasms stem cells, colorectal cancer stem cell (CR-CSCs) markers, etc. Electronic searches were supplemented by hand searching reference lists, abstracts and proceedings from meetings. Isolation of CR-CSCs can be achieved by targeting and selecting subpopulation of tumor cells based on expression of one or multiple cell surface markers associated with cancer self-renewal, markers as: CD133, CD166, CD44, CD24, beta1 integrin-CD29, Lgr5, EpCAM (ESA), ALDH-1, Msi-1, DCAMLK1 or EphB receptors. The identification and localization of CR-CSCs through different markers will hopefully lead to a better stratification of prognosis and treatment response, as well as the development of new effective strategies for cancer management.

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.

Evaluation of cancer stem cell markers CD133, CD44, CD24: association with AKT isoforms and radiation resistance in colon cancer cells

The cell surface proteins CD133, CD24 and CD44 are putative markers for cancer stem cell populations in colon cancer, associated with aggressive cancer types and poor prognosis. It is important to understand how these markers may predict treatment outcomes, determined by factors such as radioresistance. The scope of this study was to assess the connection between EGFR, CD133, CD24, and CD44 (including isoforms) expression levels and radiation sensitivity, and furthermore analyze the influence of AKT isoforms on the expression patterns of these markers, to better understand the underlying molecular mechanisms in the cell. Three colon cancer cell-lines were used, HT-29, DLD-1, and HCT116, together with DLD-1 isogenic AKT knock-out cell-lines. All three cell-lines (HT-29, HCT116 and DLD-1) expressed varying amounts of CD133, CD24 and CD44 and the top ten percent of CD133 and CD44 expressing cells (CD133high/CD44high) were more resistant to gamma radiation than the ten percent with lowest expression (CD133low/CD44low). The AKT expression was lower in the fraction of cells with low CD133/CD44. Depletion of AKT1 or AKT2 using knock out cells showed for the first time that CD133 expression was associated with AKT1 but not AKT2, whereas the CD44 expression was influenced by the presence of either AKT1 or AKT2. There were several genes in the cell adhesion pathway which had significantly higher expression in the AKT2 KO cell-line compared to the AKT1 KO cell-line; however important genes in the epithelial to mesenchymal transition pathway (CDH1, VIM, TWIST1, SNAI1, SNAI2, ZEB1, ZEB2, FN1, FOXC2 and CDH2) did not differ. Our results demonstrate that CD133high/CD44high expressing colon cancer cells are associated with AKT and increased radiation resistance, and that different AKT isoforms have varying effects on the expression of cancer stem cell markers, which is an important consideration when targeting AKT in a clinical setting.

Immunohistochemical detection of cancer stem cell related markers CD44 and CD133 in metastatic colorectal cancer patients

Aim. The goal of this study was to semiquantitatively detect presence of cancer stem cells markers CD44 and CD133 in immunohistochemically stained paired samples of colorectal cancer (CRC) and colorectal liver metastases (CLM). Level of staining intensity was compared to clinical and pathological characteristics of tumors with the aim to identify impact of CD44 or CD133 expression on tumor behavior. Patients and Methods. Formalin fixed paraffin embedded samples from 94 patients with colorectal tumor and liver metastases were collected at Sikl's Department of Pathology. Samples were stained by antibodies against CD44 and CD133. Presence and intensity of staining was assessed semiquantitatively by three trained researchers. Results. Patients with higher level of CD133 staining in CRC had longer disease free interval (Cox-Mantel P = 0.0244), whereas we found no relation between CD44 expression and overall survival or disease free interval. CD133 expression in CRC and CLM differed based on CRC grading; in case of CD44 we found differences in staining intensity in individual stages of tumor lymph node invasion. Conclusion. Effect of cancer stem cell markers on prognosis of colorectal cancer can vary depending on pathological classification of tumor, and we have shown that CD133, generally considered to be a negative marker, can bear also clinically positive prognostic information in group of patients with colorectal liver metastases.

Molecular profiling in colorectal cancer: current state of play and future directions

SUMMARY In the era of molecular scientific discovery, there is a continuing gap between our growing scientific knowledge and its utility at the bedside. This phenomenon probably occurs more frequently in colorectal cancer than in other cancer streams, with thousands of scientific studies having produced only a handful of molecular interventions. This review examines our current practices of molecular profiling in colorectal cancer and the scientific research that may impact on this area in the future.

Prognostic role of neutrophil-to-lymphocyte ratio in colorectal cancer: a systematic review and meta-analysis

The prognostic role of inflammation index like neutrophil-to-lymphocyte ratio (NLR) in colorectal cancer (CRC) remains controversial. We conduct a meta-analysis to determine the predictable value of NLR in the clinical outcome of CRC patients. The analysis was carried out based on the data from 16 studies (19 cohorts) to evaluate the association between NLR and overall survival (OS) and progression-free survival (PFS) in patients with CRC. In addition, the relationship between NLR and clinicopathological parameters was assessed. Hazard ratio (HR) or odds ratio (OR) with its 95% confidence interval (CI) was used as the effect size estimate. Our analysis results indicated that elevated pretreatment NLR predicted poorer OS (HR: 1.813, 95% CI: 1.499-2.193) and PFS (HR: 2.102, 95% CI: 1.554-2.843) in patients with CRC. Increased NLR is also significantly associated with the poorer differentiation of the tumor (OR: 1.574, 95% CI: 1.226-2.022) and higher carcino-embryonie antigen (CEA) level (OR: 1.493, 95% CI: 1.308-1.705). By these results, we conclude that NLR gains a prognostic value for patients with CRC. NLR should be monitored in CRC patients for rational stratification of the patients and adjusting the treatment strategy.

Effects of metformin on CD133+ colorectal cancer cells in diabetic patients

In diabetic patients complicated with colorectal cancer (CRC), metformin treatment was reported to have diverse correlation with CRC-specific mortality. In laboratory studies, metformin was reported to affect the survival of cancer stem cells (CSCs) in breast and pancreatic cancers and glioblastoma. Although cscs play a critical role in the resistance to 5-fluorouracil (5-FU) chemotherapy in CRC patients, the effect of metformin on cscs in CRC patients and the synergistic effect of metformin in combination with 5-FU on cscs are not reported. In the present study pathological examinations were performed in 86 CRC patients complicated with type 2 DM who had been divided into a metformin group and a non-metformin group. Comparisons regarding pathological type, incidence of metastasis, expression of CD133 and β-catenin were conducted between the two groups. We explored the synergistic effects of metformin in combination with 5-FU on the proliferation, cell cycle, apoptosis and the proportion of CD133+ cscs of SW620 human colorectal cancer cell lines. The results show that metformin treatment had reverse correlations with the proportion of patients with poorly differentiated adenocarcinoma, the proportion of CD133+ cscs in CRC patients with type 2 DM. Metformin enhanced the antiproliferative effects of 5-FU on CD133+ cscs in SW620 cells. These findings provide an important complement to previous study. Inhibition of the proliferation of CD133+ cscs may be a potential mechanism responsible for the association of metformin use with improved CRC outcomes in CRC patients with type 2 diabetes.