Cancer stem cell marker expression in hepatocellular carcinoma and liver metastases is not sufficient as single prognostic parameter

Recent findings suggest that the presence of cancer stem cells could be linked with patients’ survival. We profiled suggested cancer stem cell markers in tissue specimens of hepatocellular carcinoma and colorectal carcinoma liver metastases. About 1% of cells co-expressed cancer stem cell antigens, but there was no correlation between the amount of CD133⁺, CD133⁺/CD44⁺ or CD133⁺/CD24⁻ cells and the patients’ clinical–pathological status or with the cancer stem cell marker-positive cells localization. CD133⁺ and CD133⁻ fractions of Huh7 cells did not differ in migratory properties. Therefore, presence of markers alone should be taken with caution as single prognostic parameters.     

Still proliferating CD44+/Ki67+ tumor cells after neoadjuvant radiochemotherapy identify rectal cancer patients with poor survival

IntroductionDistant recurrence, especially liver metastases, occurs in one-third of rectal cancer patients initially treated with curative therapy and is still an unsolved problem. The identification of patients at risk is crucial for enabling individualized treatment.Material and methodsAll patients undergoing curative resection for histologically confirmed rectal cancer after neoadjuvant radiochemotherapy between January 2001 and December 2015 were included. Sections were stained for Ki67, CD44, apoptosis and CD133. Patients were categorized based on whether they were found to have (CD44⁺/Ki67⁺) or not have (CD44⁺/Ki67⁺) still proliferating tumor cells.Results218 patients who underwent R0 resection for stage I-III rectal cancer were selected. In 37 (17%) of these patients, CD44⁺/Ki67⁺ tumor cells were found. In multivariable Cox regression analysis, patients with CD44⁺/Ki67⁺ cells had significantly impaired overall (hazard ratio (HR): 3.84, 95% CI: 1.77–8.31, p = 0.001) and relative survival (HR 3.44, 95% CI: 1.46–8.09). The previous results were confirmed after propensity-score matching. In mediation-analysis, the presence of CD44⁺/Ki67⁺ cells was associated with a substantial direct effect on overall (HR 1.92, 95% CI: 1.09–9.28) and relative survival (HR 1.63, 95% CI: 1.31–6.38).ConclusionsThe presence of still proliferating CD44⁺/Ki67⁺ tumor cells after neoadjuvant radiochemotherapy was associated with impaired oncological long-term outcomes. Characterization of these cells should be performed.     

CD133 + cell infusion in patients with colorectal liver metastases going to be submitted to a major liver resection (CELLCOL): A randomized open label clinical trial

BackgroundTreatment of liver metastases of colorectal carcinoma is surgical resection. However, only 10–15% of the patients in this context will be candidate for curative resection arising other 10–13% after response to neoadyuvant chemotherapy. In order to perform the liver metastases surgery, it is necessary to have a sufficient remnant liver volume (RLV) which allows maintaining an optimal liver function after resection.Studies on liver regeneration have determined that CD133 + stem cells are involved in liver hypertrophy developed after an hepatectomy with encouraging results. As presented in previous studies, CD133 + stem cells can be selected from peripheral blood after stimulation with G-CSF, being able to obtain a large number of them. We propose to treat patients who do not meet criteria for liver metastases surgery because of insufficient RLV (<40%) with CD133 + cells together with portal embolization, in order to achieve enough liver volume which avoids liver failure.Methods/Design: The aim of this study is to evaluate the effectiveness of preoperative PVE plus the administration of CD133 + mobilized from peripheral blood with G-CSF compared to PVE only.Secondary aims areto compare the grade of hypertrophy, speed and changes in liver function, anatomopathological study of hypertrophied liver, to determine the safety of the treatment and analysis of postoperative morbidity and surveillance.Study designProspective randomized longitudinal phase IIb clinical trial, open, to evaluate the efficacy of portal embolization (PVE) together with the administration of CD133 + cells obtained from peripheral blood versus PVE alone, in patients with hepatic metastasis of colorectal carcinoma (CCRHM).DiscussionThe number of CD133 + obtained from peripheral blood after G –CSF stimulation will be far greater than the number obtained with direct puncture of bone marrow. This will allow a greater intrahepatic infusion, which could have a direct impact on achieving a larger and quicker hypertrophy. Consequently, it will permit the treatment of a larger number of patients with an increase on their survival.Trial registrationClinicalTrials.gov, ID NCT03803241.     

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.     

Tumour CD133 mRNA expression and clinical outcome in surgically resected colorectal cancer patients

BackgroundHuman prominin-1 (CD133) is a novel pentaspan membrane protein which was originally classified as a marker of primitive haematopoietic and neural stem cells. Cancer stem cells have been isolated and expanded from leukaemia and several solid tumours, and have been associated with metastasis, chemoresistance and relapse. CD133 is recognised as a stem cell marker and is capable of identifying a tumour-initiating subpopulation in brain, colon, melanoma and other solid tumours.MethodsWe assessed CD133 mRNA expression levels by RT-QPCR in tumour and matched normal tissue from 64 stages I–III colorectal cancer (CRC) patients and correlated tumour CD133 levels with clinicopathological characteristics and clinical outcome.ResultsIn four patients, CD133 mRNA was not expressed in tumour or in normal tissue. In the remaining 60 patients, expression levels were higher in tumour than in normal tissue (p = 0.001). Higher levels of CD133 expression were associated with shorter relapse-free interval (RFI) (p = 0.004) and overall survival (OS) (p < 0.0001). In the multivariate analyses, CD133 levels emerged as a prognostic marker for RFI and OS.ConclusionsWe have observed longer RFI and OS in patients with lower levels of CD133, regardless of adjuvant treatment and other clinical characteristics. If these findings are confirmed in larger prospective studies, CD133 assessment may prove useful for new diagnostic and therapeutic procedures for CRC patients.     

The expression and clinical significance of β-catenin and colorectal cancer stem cells marker EpCAMhigh/CD44+ in colorectal cancer

Objective

The aim of the study was to explore the role of Wnt/β-catenin signalling pathway in the maintenance, invasion and metastasis of colorectal cancer stem cells.

Methods

Double immunohistochemical staining was used to detect the expression of EpCAM^high/CD44⁺ which is regarded as the marker of colorectal cancer stem cells in 80 cases of colorectal cancer and their corresponding liver metastases. The SP method of immunohistochemistry was used to detect the expression of the key protein β-catenin in the Wnt pathway in these tissue. The expression and correlation of β-catenin and EpCAM^high/CD44⁺ in colorectal cancer were analyzed and their role on the biological behavior of colorectal cancer was explored.

Results

The abnormal expression of β-catenin was significantly higher in colorectal cancer than in the paraneoplastic normal intestinal mucosa [55% (44/80) vs 10% (2/20), P < 0.05]. The positive expression of EpCAM^high/CD44⁺ was significantly higher in colorectal cancer than in the paraneoplastic normal intestinal mucosa [66.25% (53/80) vs 0% (0/20), P < 0.05]. In the 80 cases of colorectal cancer, the abnormal expression of β-catenin has no correlation with gender (P = 0.079), age (P = 0.416) and the magnitude (P = 0.816) of the tumor (P > 0.05), but it was significantly correlated with degree of differentiation (P = 0.001), depth of invasion (P = 0.001), clinical stage (P = 0.000) and metastasis (P = 0.000). In the colorectal cancer, the expression of EpCAM^high/CD44⁺ cells has no correlation with gender (P = 0.934) and the magnitude (P = 0.160) of the tumor (P > 0.05), but was significantly correlated with age (P = 0.021), degree of differentiation (P = 0.013), depth of invasion (P = 0.000), clinical stage (P = 0.000) and metastasis (P = 0.000). In the corresponding liver metastases, we could also detecte EpCAM^high/CD44⁺ cells. In cases with abnormal expression of β-catenin, the positive expression rate of EpCAM^high/CD44⁺ was significantly higher than those with normal expression of β-catenin (84.1% vs 44.4%), and the difference was statistically significant (P < 0.05).

Conclusion

The abnormal activation of Wnt/β-catenin signalling pathway may prompt the abnormal proliferation of the colorectal cancer stem cells, which leads to the recurrence and metastasis of the cancer.     

Expression and prognostic value of epithelial-to-mesenchymal transition and cancer stem cellmarkersin primary lesions and liver metastases of colorectal cancers

Cancer stem cells (CSCs) and epithelial mesenchymal transition (EMT) markers are considered useful indicators associated with metastasis and prognosis of colorectal cancers (CRCs). However, only a few studies have focused on the expression of these useful markers in metastases. Metastasectomy is widely used in advanced CRCs, and thus the postoperative prognostic factors are worth investigating. The present study investigated the consistency and differences of target proteins between primary and metastatic lesions of colorectal cancer, and discussed the prognostic indicators following resection of colorectal liver metastases. Clinical data of 56 patients with liver metastases from colorectal cancer were collected and the expression levels of target proteins (Ki-67, CD133, CD44, Snail, E-cadherin and β-catenin) were detected in primary tumor and matched liver metastases via immunohistochemistry analysis. Paired comparison between both tissue types was performed. The prognostic values of the target proteins for resectable colorectal cancer liver metastases were assessed. No significant differences were observed between the primary tissues and metastatic tissues. The consistency rates of these protein expression levels ranged from 51.8–78.6%. The maximum diameter of the liver metastases was <5 cm. Low Snail expression in metastases was associated with a longer overall survival (OS) time following resection of colorectal liver metastases. Furthermore, N0 stage and low carcinoembryonic antigen levels were associated with a longer progression-free survival time. Notably, no significant differences were observed in expression levels of the target proteins between the primary tumors and liver metastases. Taken together, the results of the present study suggest that Snail expression in liver metastases may be used as a novel independent prognostic factor for OS following resection of colorectal liver metastases.     

Prognostic impact of the expression of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and ALDH1 in colorectal cancer

Background:

The aim of this study was to elucidate the prognostic impact of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and aldehyde dehydrogenase-1 (ALDH1) in colorectal cancer.

Methods:

A tissue microarray of 1420 primary colorectal cancers and 57 normal mucosa samples was immunostained for CD133, CD166, CD44s, EpCAM, and ALDH1 in addition to 101 corresponding whole tissue sections. Invasive potential of three colorectal cancer cell lines was tested.

Results:

Differences between normal tissue and cancer were observed for all markers (P<0.001). Loss of membranous CD166 and CD44s were linked to higher pT (P=0.002, P=0.014), pN (P=0.004, P=0.002), an infiltrating growth pattern (P<0.001, P=0.002), and worse survival (P=0.015, P=0.019) in univariate analysis only. Loss of membranous EpCAM expression was also linked to higher pN (P=0.023) and infiltrating growth pattern (P=0.005). The CD44s, CD166, and EpCAM expression were lost towards the invasive front. The CD44−/CD166− cells from three colorectal cancer cell lines exhibited significantly higher invasive potential in vitro than their positive counterparts.

Conclusions:

Loss, rather than overexpression, of membranous CD44s, CD166, and EpCAM is linked to tumour progression. This supports the notion that the membranous evaluation of these proteins assessed by immunohistochemistry may be representative of their cell adhesion rather than their intra-cellular functions.     

Brca1 breast tumors contain distinct CD44+/CD24- and CD133+ cells with cancer stem cell characteristics

Introduction

Whether cancer stem cells occur in BRCA1-associated breast cancer and contribute to therapeutic response is not known.

Methods

We generated and characterized 16 cell lines from five distinct Brca1deficient mouse mammary tumors with respect to their cancer stem cell characteristics.

Results

All cell lines derived from one tumor included increased numbers of CD44⁺/CD24^- cells, which were previously identified as human breast cancer stem cells. All cell lines derived from another mammary tumor exhibited low levels of CD44⁺/CD24^- cells, but they harbored 2% to 5.9% CD133⁺ cells, which were previously associated with cancer stem cells in other human and murine tumors. When plated in the absence of attachment without presorting, only those cell lines that were enriched in either stem cell marker formed spheroids, which were further enriched in cells expressing the respective cancer stem cell marker. In contrast, cells sorted for CD44⁺/CD24^- or CD133⁺ markers lost their stem cell phenotype when cultured in monolayers. As few as 50 to 100 CD44⁺/CD24^- or CD133⁺ sorted cells rapidly formed tumors in nonobese diabetic/severe combined immunodeficient mice, whereas 50-fold to 100-fold higher numbers of parental or stem cell depleted cells were required to form few, slow-growing tumors. Expression of stem cell associated genes, including Oct4, Notch1, Aldh1, Fgfr1, and Sox1, was increased in CD44⁺/CD24^- and CD133⁺ cells. In addition, cells sorted for cancer stem cell markers and spheroid-forming cells were significantly more resistant to DNA-damaging drugs than were parental or stem cell depleted populations, and they were sensitized to the drugs by the heat shock protein-90 inhibitor 17-DMAG (17-dimethylaminoethylamino-17-demethoxygeldanamycin hydrochloride).

Conclusion

Brca1-deficient mouse mammary tumors harbor heterogeneous cancer stem cell populations, and CD44⁺/CD24^- cells represent a population that correlates with human breast cancer stem cells.     

CD133+ liver cancer stem cells modulate radioresistance in human hepatocellular carcinoma

CD133 is a cancer stem-cell (CSC) marker associated with radioresistance and chemoresistance in various cancers. In the present study, CD133-expressing liver cancer cells following radiation exposure showed higher activation of MAPK/PI3K signaling pathway and reduction in reactive oxygen species levels compared to CD133⁻ cells. The in vivo study with a xenograft model showed increased tumor formation in irradiated CD133⁺ cell-injected nude mice compared to the CD133⁻ group, suggesting that CD133 contributes to radioresistance in HCC. Therefore, CD133-expressing liver cancer cells have anti-apoptotic and radioresistance properties that may be useful to improve anti-cancer treatments, including chemotherapy/radiotherapy of HCC.     

Treatment of metachronous colorectal cancer metastases in the Netherlands: A population-based study

BackgroundThis study aimed to describe the treatment of metachronous colorectal cancer metastases in a recent population-based cohort.MethodPatients with stage I-III colorectal cancer (CRC), diagnosed between January 1st and June 30th^, 2015 who were surgically treated with curative intent were selected from the Netherlands Cancer Registry. Follow-up was at least 3 years after diagnosis of the primary tumour. Treatment of metachronous metastases was categorized into local treatment, systemic treatment, and best supportive care. Overall survival was estimated using Kaplan-Meier method.ResultsOut of 5412 patients, 782 (14%) developed metachronous metastases, of whom 393 (50%) underwent local treatment (LT) with or without systemic therapy, 30% of patients underwent only systemic therapy (ST) and 19% only best supportive care (BSC). The most common metastatic site was the liver (51%) followed by lungs (33%) and peritoneum (22%). LT rates were 69%, 66%, and 44% for liver-only, lung-only and, peritoneal-only metastases respectively. Patients receiving LT and ST were significantly younger than patients receiving LT alone, while patients receiving BSC were significantly older than the other groups (p < 0.001). Patients with liver-only or lung-only metastases had a 3-year OS of 50.2% (43.3–56.7 95% CI) and 61.5% (50.7–70.6 95% CI) respectively. Patients with peritoneal-only disease had a lower 3-year OS, 18.1% (10.1–28.0 95% CI).ConclusionPatients with metastases confined to the liver and lung have the highest rates of local treatment for metachronous metastatic colorectal cancer. The number of patients who underwent local treatment is higher than reported in previous Dutch and international studies.     

Impact of Size and Location of Metastases on Early Tumor Shrinkage and Depth of Response in Patients With Metastatic Colorectal Cancer: Subgroup Findings of the Randomized,Open-Label Phase 3 Trial FIRE-3/AIO KRK-0306

BackgroundThe Response Evaluation Criteria in Solid Tumors (RECIST) are used to define degrees of response to chemotherapy. For accelerated response evaluation, early tumor shrinkage (ETS) of ≥ 20% has been suggested as a predictor for outcome in metastatic colorectal cancer (mCRC). Together with depth of response (DpR), new alternative metrics have been provided, yielding promising outcome parameters. In this analysis, we aimed to further characterize ETS and DpR.Patients and MethodsThis analysis was based on FIRE-3, a randomized phase 3 trial comparing first-line FOLFIRI plus either cetuximab or bevacizumab in KRAS exon 2 wild-type mCRC. ETS and DpR were determined on the basis of RECIST 1.1 in a blinded radiologic review. ETS was evaluated as a categorized (≥ 20% shrinkage) and continuous parameter. The impact of baseline location and size of metastases on ETS and DpR were evaluated by univariate and multivariate analyses.ResultsOf 592 patients, 395 (66.7%) had data available for radiologic review. Median continuous ETS for lung, liver, and suspected lymph node metastases was 20%, 23%, and 30%, respectively. The median DpR was −32%, −44%, and −50%, respectively (all P < .01). In multivariate analysis, lung metastases were significantly associated with inferior DpR (P = .021), whereas hepatic metastases led to higher DpR (P = .024). Large metastases were associated with favorable ETS, whereas small metastases were correlated with higher DpR (P < .001).ConclusionETS and DpR depend on the location and size of metastases in mCRC. These associations may establish the basis for further research to optimize the predictive accuracy of both parameters. This may help basing treatment decisions on ETS and DpR.     

Prognostic impact of immune response in resectable colorectal liver metastases treated by surgery alone or surgery with perioperative FOLFOX in the randomised EORTC study 40983

AimTo investigate whether the immune response in colorectal liver metastases is related to progression free survival (PFS) and if this may be influenced by systemic therapy.MethodsA retrospective central collection of tumour tissue was organised for the European Organisation for Research and Treatment of Cancer (EORTC) study 40983, where patients with colorectal liver metastases were treated by either resection alone or resection with perioperative FOLFOX. Immunostaining on whole slides was performed to recognise T-lymphocytes (CD3+, CD4+, CD8+), B-lymphocytes (CD20+), macrophages (CD68+) and mast cells (CD117+) inside the tumour, at the tumour border (TNI) and in normal liver tissue surrounding the tumour (0.5–2 mm from the TNI). Immunological response was compared between treatment arms and correlated to PFS.ResultsTumour tissue and immune response profiles were available for 82 resected patients, 38 in the perioperative chemotherapy arm and 44 in the surgery alone arm. Baseline patient and disease characteristics were similar between the treatment arms. In response to chemotherapy, we observed increased CD3+ lymphocyte and mast cell counts inside the tumour (p < 0.01), lower CD4+ lymphocytes in the normal liver tissue (p = 0.02) and lower macrophage counts in normal tissue (p < 0.01) and at the TNI (p = 0.02). High number of CD3+ lymphocyte and mast cells, and high T-cell score were correlated with tumour regression grade (TRG). Prolonged PFS correlated with the presence of mast cells in the tumour (9.8 versus 16.5 months, Hazard ratio (HR) 0.54 p = 0.03), higher CD3+ lymphocyte count at the TNI (10.8 versus 22.8 months, HR 0.57, p = 0.03) and T-cell score >2 (10.8 versus 38.6 months, HR 0.51, p = 0.04).ConclusionOur analyses in the context of a randomised study suggest that chemotherapy influences immune cell profiles, independent of patient characteristics. Immune responses of lymphocytes and mast cells were associated with pathological response to chemotherapy and to increased PFS. High CD3+ lymphocytes at the tumour front and intratumoural mast cells appear to be prognostic for patients with colorectal liver metastases.     

Radioembolisation for liver metastases: Results from a prospective 151 patient multi-institutional phase II study

PurposeTo investigate the safety, response rate, progression-free and overall survival of patients with liver metastases treated with ⁹⁰Y (glass) radioembolisation in a prospective, multicenter phase II study.Methods151 patients with liver metastases (colorectal n = 61, neuroendocrine n = 43 and other tumour types n = 47) refractory to standard of care therapies were enrolled in this prospective, multicenter, phase II study under an investigational device exemption. Clinical/laboratory/imaging follow-up were obtained at 30 days followed by 3-month intervals for 1 year and every 6 months thereafter. The primary end-point was progression-free survival (PFS); secondary end-points included safety, hepatic progression-free survival (HPFS), response rate and overall survival.ResultsMedian age was 66 (range 25–88). Grade 3/4 adverse events included pain (12.8%), elevated alkaline phospatase (8.1%), hyperbilirubinemia (5.3%), lymphopaenia (4.1%), ascites (3.4%) and vomiting (3.4%). Treatment parameters including dose delivery were reproducible among centers. Disease control rates were 59%, 93% and 63% for colorectal, neuroendocrine and other primaries, respectively. Median PFS was 2.9 and 2.8 months for colorectal and other primaries, respectively. PFS was not achieved in the neuroendocrine group. Median survival from ⁹⁰Y treatment was 8.8 months for colorectal and 10.4 months for other primaries. Median survival for neuroendocrine patients has not been reached.ConclusionPatients with liver metastases can be safely treated with ⁹⁰Y microspheres. This study is the first to demonstrate technical and dose reproducibility of ⁹⁰Y glass microspheres between centers in a prospective setting. Based on these promising data, three international, multicenter, randomised phase III studies in colorectal and hepatocellular carcinoma have been initiated.     

Cancer stem cell enrichment marker CD98: A prognostic factor for survival in patients with human papillomavirus-positive oropharyngeal cancer

PurposeSeveral hypotheses have been proposed to explain the relatively good prognosis of patients with a human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) and one of these is a higher sensitivity to (chemo)radiation. Previous studies have suggested that treatment failure in OPSCC patients is caused by resistance of cancer stem cells (CSCs). The purpose of this study was to evaluate the association between the number of CSCs and prognosis in HPV-positive OPSCC patients.Experimental designAll OPSCC patients (n = 711) treated between 2000 and 2006 in two Dutch university hospitals were included. Presence of HPV in a tumour tissue specimen was tested by p16-immunostaining followed by HPV DNA GP5+/6+polymerase chain reaction (PCR). The presence and intensity of tumour CSC markers CD44 and CD98 were determined by immunohistochemistry and semiquantitative scoring was performed. Overall survival (OS) and progression-free survival (PFS) rates were compared between patients with low and high CD44/CD98 expression in relation to HPV status.ResultsHPV-positive tumours showed a lower percentage of cells with CD44 and CD98 expression than HPV-negative tumours (p < 0.001, χ²-test). Within the group of patients with HPV-positive OPSCC, a high percentage of CD98-positive tumour cells was associated with a significantly worse 5-year OS and PFS (OS: 36.4% and PFS: 27.3%) compared to patients with a low percentage of CD98-positive cells (OS: 71.9% and PFS: 70.5%, respectively) (p < 0.001).ConclusionsHPV-positive OPSCCs harbour fewer cells expressing the CSC enrichment markers CD44 and CD98. Furthermore, OS and PFS were significantly worse for patients with HPV-positive OPSCC with a high percentage of CD98-positive cells.     

Efficacy and Tolerability of Selective Internal Radiotherapy With Yttrium-90 as Consolidation Treatment After Chemotherapy in Metastatic Colorectal Cancer

BackgroundSelective internal radiotherapy (SIRT) with yttrium-90 (Y-90)-labeled resin microspheres may have a role in consolidating the response to chemotherapy in patients with metastatic colorectal cancer unamenable to resection after assessment of the best response to first-line chemotherapy.Patients and MethodsThis was a retrospective analysis of outcomes in patients who had received SIRT as consolidation therapy after one or more lines of chemotherapy. Eligible patients were 18 years or older, had confirmed colorectal liver metastases, and had disease unsuitable for surgical resection or local ablation with curative intent. The primary endpoint was progression-free survival.ResultsSixty-eight patients with colorectal liver metastases were treated with at least one SIRT procedure after receiving one or more lines of chemotherapy. Median progression-free survival was significantly longer in patients who received SIRT after prior first-line chemotherapy compared to those who received SIRT after two or more lines of chemotherapy (9 vs. 3 months, respectively; hazard ratio = 0.07; 95% confidence interval, 0.02854‒0.2039; P < .001), and in patients with liver-only disease compared to those who had extrahepatic metastases (6.4 vs. 4.1 months, respectively; hazard ratio = 0.57; 95% confidence interval, 0.34-0.95; P = .0318). There were no grade 3 or higher adverse events.ConclusionSIRT represents a valid option for the treatment of colorectal liver metastases. Earlier use of SIRT may provide a greater survival benefit compared to that afforded by the procedure when used in salvage settings.     

CD66c is a novel marker for colorectal cancer stem cell isolation,and its silencing halts tumor growth in vivo

BACKGROUND:

Despite the well recognized expression of the cell surface markers cluster of differentiation 44 (homing cell adhesion molecule) and CD133 (Prominin 1) on human colorectal cancer stem cells (CCSCs), these molecules do not appear to be effective targets for stem cell‐directed therapies. Because the surface marker CD66c (also known as carcinoembryonic antigen‐related cell adhesion molecule 6) has demonstrated promise as a therapeutic target in pancreatic malignancy, the authors evaluated its potential as a target for stem cell‐directed treatment of colorectal cancer.

METHODS:

First, the authors characterized CD66c expression by flow cytometry and immunohistochemistry in colon cancer samples and in normal colon tissues. Then, the coexpression of CD66c and CD133 was evaluated on putative CCSCs. CD66c expression also was measured in stem cell‐enriched colon spheres. Finally, the effects of small‐interfering RNA‐mediated CD66c silencing on the in vitro and in vivo growth of Caco2 colon cancer cells were evaluated.

RESULTS:

CD66c expression was significantly higher in colon cancers than in contiguous normal colon tissues and paralleled cancer stage. CD66c was absent in CD133‐positive cells that were isolated from normal colon, whereas its expression was brightest (CD66c^bright) in CD133‐positive cells from colon cancer samples. In vitro experiments demonstrated that colon spheres were considerably enriched in a CD66c^bright population in a fashion comparable to the enrichment observed in fresh liver metastases. In vitro proliferation and clonogenic potential were hampered when CD66c was silenced in Caco2 cells. Finally, in vivo xenograft experiments demonstrated that CD66c silencing almost completely abrogated the tumorigenic potential of Caco2 cells.

CONCLUSIONS:

CD66c^bright expression was associated with colon cancer stem cells and CD66c silencing blocked tumor growth, thereby opening the way to a potential new treatment for colon cancer. Cancer 2013. © 2012 American Cancer Society.     

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%.