大肠癌患者外周血细胞CD133的表达

背景：近期有报道称在肿瘤患者外周血中检测出了高于正常值的CD133阳性细胞。 目的：观察CD133 mRNA和蛋白在大肠癌患者外周血中的表达并探讨其临床意义。 方法：应用流式细胞技术与RT-PCR反应检测29例大肠癌患者和20例正常对照外周血中CD133 抗原与mRNA的表达。 结果与结论：发生转移的大肠癌患者外周血中CD133阳性细胞比例显著高于正常对照及无转移的大肠癌患者(P < 0.01)。正常健康人群和无转移大肠癌患者外周血中CD133mRNA表达为阴性,发生转移的部分大肠癌患者外周血中CD133mRNA表达阳性,阳性率为35.7%(5/14),在超过38个以上循环时表达为弱阳性。结果表明,无转移大肠癌患者外周血中CD133 mRNA和蛋白表达与正常对照无区别,发生转移的大肠癌患者外周血中CD133 mRNA和蛋白高于正常对照和未发生转移者。     

Safety profile and pharmacokinetic analyses of the anti-CTLA4 antibody tremelimumab administered as a one hour infusion

The aim of this study was to assess the prognostic and predictive values of circulating tumor cell (CTC) analysis in colorectal cancer patients. Presence of CTCs was evaluated in 60 colorectal cancer patients before systemic therapy - from which 33 patients were also evaluable for CTC analysis during the first 3 months of treatment - through immunomagnetic enrichment, using the antibodies BM7 and VU1D9 (targeting mucin 1 and EpCAM, respectively), followed by real-time RT-PCR analysis of the tumor-associated genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5. Patients were stratified into groups according to CTC detection (CTC negative, when all marker genes were negative; and CTC positive when at least one of the marker genes was positive). Patients with CTC positivity at baseline had a significant shorter median progression-free survival (median PFS 181.0 days; 95% CI 146.9-215.1) compared with patients with no CTCs (median PFS 329.0 days; 95% CI 299.6-358.4; Log-rank P < .0001). Moreover, a statistically significant correlation was also founded between CTC detection during treatment and radiographic findings at the 6 month staging. This correlation applied to CTC results before therapy (odds ratio (OR), 6.22), 1 to 4 weeks after beginning of treatment (OR, 5.50), 5 to 8 weeks after beginning of treatment (OR, 7.94) 9 to 12 weeks after beginning of treatment (OR, 14.00) and overall CTC fluctuation during the course of treatment (OR, 20.57). The present study provides evidence of a strong correlation between CTC detection and radiographic disease progression in patients receiving chemotherapy for colorectal cancer. Our results suggest that in addition to the current prognostic factors, CTC analysis represent a potential complementary tool for prediction of colorectal cancer patients’ outcome. Moreover, the present test allows for molecular characterization of CTCs, which may be of relevance to the creation of personalized therapies.     

Detection of metastatic colon cancer cells in sentinel nodes by flow cytometry

In colon cancer the presence of metastases in the regional lymph nodes is an important prognostic factor. Currently, examination is based on histological and immunohistochemical evaluations of lymph node sections. However, these methods are time-consuming, labour intensive and micro-metastases might be missed. The sentinel node technique may be used to identify the direct tumour draining lymph node. In this study the possible use of flow cytometry for detection of sentinel node metastases in patients with colon cancer has been investigated.

Peripheral blood mononuclear cells (PBMC) with the addition of DLD-1 colon cancer cells were stained intracellularly for cytokeratin 20 (CK20), and for the cell surface markers epithelial cell adhesion molecule (EpCAM) and carbohydrate antigen 19-9 (CA19-9). CK20 positive colon cancer cells were reliably detected with as few as 0.037% events. However, PBMCs from both colon cancer patients and from healthy individuals contained CK20 positive cells. Staining for EpCAM resulted in an almost complete recovery of tumour cells, and as few as 0.037% added cells were detected. Low intra-assay variability was determined for EpCAM (CV 8.8) and CA19-9 (CV 9.7) stainings. The results from staining for CK20 or for EpCAM and CA19-9 concorded, but the degree to which respective antigens were expressed varied. The use of flow cytometry for detection of metastatic colon cancer cells was verified in fourteen sentinel nodes specimens from patients with colon cancer.

Herein we have explored the potential of flow cytometry to become a fast, sensitive and reliable method for detection of lymphatic metastases in patients with colon cancer using direct fluorophore-conjugated antibodies against multiple surface antigens. The method seems feasible and further testing is warranted.     

Combined use of positive and negative immunomagnetic isolation followed by real-time RT-PCR for detection of the circulating tumor cells in patients with colorectal cancers

To establish a novel molecular diagnostic method of detecting circulating tumor cells (CTCs) LS174T colon cancer cells were serially diluted with normal blood. Additional peripheral blood samples were collected from 25 patients with colorectal carcinoma. Mononuclear cells (MNCs) were collected, equally divided into four parts, and then cancer cells were enriched by four methods: method A, nonimmunobead method; method B, negative immunobead method: CD45 immunomagnetic beads were used to deplete the leukocytes; method C, positive immunobead method: Ber-EP4 immunomagnetic beads were used to enrich cancer cells; method D, negative-and-positive immunobead method: CD45 immunomagnetic beads were first used to deplete the leukocytes from MNC and then Ber-EP4 immunomagnetic beads were used to enrich cancer cells. Finally, real-time quantitative RT-PCR was used to monitor mRNA expression of ₂-mircoglobulin (2M) and carcinoembryonic antigen (CEA). The relative CEA mRNA values were corrected with reference to 2M mRNA, to CEA mRNA/2M mRNA ratios according to a CEA mRNA external standards prepared with tenfold serial dilutions (1–10⁴ IS174T cells) of cDNA and 2M mRNA external standards prepared with tenfold serial dilutions (10²–10⁷ leukocytes) of cDNA. In recovery experiments a significant correlation between the number of cancer cells and CEA mRNA expression was found when CD45 or Ber-EP4 immunomagnetic beads were used alone. A highly significant correlation was found when CD45 and Ber-EP4 immunomagnetic beads were used successively. The sensitivity of method D was one cancer cell per milliliter of blood. Circulating cancer cells were detected in 19 of 25 patients with colorectal cancers. The relative CEA mRNA value obtained by method D was the smallest. The positive detection rate of circulating cancer cells in patients at Dukes B, C, and D stages were 25.0% (1/4), 83.3% (10/12), and 88.9% (8/9). Combinative use of immunomagnetic isolation followed by real-time RT-PCR is a useful technique to detect circulating tumor cells in patients with colorectal carcinomas. Applying negative and positive immunomagnetic beads successively yields the highest correlation with amount of tumor cells.     

A simple pyramid-shaped microchamber towards highly efficient isolation of circulating tumor cells from breast cancer patients

Isolation and detection of circulating tumor cells (CTCs) has showed a great clinical impact for tumor diagnosis and treatment monitoring. Despite significant progresses of the existing technologies, feasible and cost-effective CTC isolation techniques are more desirable. In this study, a novel method was developed for highly efficient isolation of CTCs from breast cancer patients based on biophysical properties using a pyramid-shaped microchamber. Through optimization tests, the outlet height of 6 μm and the flow rate of 200 μL/min were chosen as the optimal conditions. The capture efficiencies of more than 85% were achieved for cancer cell lines (SKBR3, BGC823, PC3, and H1975) spiked in DMEM and healthy blood samples without clogging issue. In clinic assay, the platform identified CTCs in 13 of 20 breast cancer patients (65%) with an average of 4.25?±?4.96 CTCs/2 mL, whereas only one cell was recognized as CTC in 1 of 15 healthy blood samples. The statistical analyses results demonstrated that both CTC positive rate and CTC counts were positive correlated with TNM stage (p < 0.001; p?=?0.02, respectively). This microfluidic platform successfully demonstrated the clinical feasibility of CTC isolation and would hold great potential of clinical application in predicting and monitoring the prognosis of cancer patients.     

Imaging cytometry for counting circulating tumor cells: comparative analysis of the CellSearch vs ImageStream systems

Circulating tumor cell (CTC) enumeration is important clinically for identifying prognostic and predictive factors in patients with solid cancers. The CellSearch device (Veridex) is an immunomagnetic CTC selection and enumeration system used in clinical practice. The ImageStream (Amnis) combines the strengths of flow cytometry and fluorescent microscopy in a single platform and has potential application for CTC counting. The performance in CTC enumeration was compared between the ImageStream and CellSearch systems. Various numbers of PANC‐1 tumor cells were spiked into 7.5 mL of peripheral blood from a healthy donor. Before cell analysis by the ImageStream, tumor cell enrichment was performed by immunomagnetic selection with anti‐EpPCAM. Anti‐CD45 and anti‐CK markers were used to discriminate between tumor cells and leukocytes. The ratios of tumor cells recovered from each dilution were calculated for both methods. The Wilcoxon rank test was applied to compare the results of the two methods and the reference value. The results of the two tested methods differed significantly from the reference value, but did not differ between them. Nevertheless, lower level of trueness and precision was observed in ImageStream when fewer numbers of CTCs were analyzed. Our results suggest that ImageStream platform for CTC enumeration has a potential value for the early diagnosis of disseminated disease, but needs an improvement of precision for the enumeration of low number of CTC.     

Detection of a circulating gastrointestinal cancer antigen in sera of patients with gastrointestinal malignancies by a double determinant immunoassay with monoclonal antibodies against human blood group determinants.

Monoclonal antibodies (MoAbs) produced against determinants A and B of the human ABO blood group system and against the Lea and Leb determinants of the Lewis (Le) blood group system detected these determinants on molecules released by cultured cells of human colorectal, gastric and/or pancreatic carcinoma (Ca) but not by a variety of other cells maintained in culture. Circulating Le antigen could be demonstrated in sera of patients by inhibiting the binding of MoAbs to a target preparation. A double determinant radioimmunoassay (DDIA) was then developed to detect the association of blood group determinants with a previously defined gastrointestinal cancer antigen (GICA). The DDIA with the anti-blood group and anti-GICA antibody was in some cases more sensitive in detecting GICA in sera than using the anti-GICA MoAb alone. Of 55 sera from patients with primary and early recurrent colorectal carcinoma (CRC), 10 (18%) were scored positive in the DDIA using only anti-GICA MoAb. When MoAb binding to a determinant on Leb and on H, type I, was used as first antibody in DDIA followed by anti-GICA MoAb 11 additional sera were reactive, increasing the percentage of positive sera to 38. Using the same combinations of MoAbs, the sensitivity of detection of GICA was only slightly improved from 63 to 66% in sera of patients with advanced CRC. The number of false positive sera from patients with non-malignant gastrointestinal diseases or from healthy donors remained at low levels when anti-blood group determinant antibodies were used together with anti-GICA MoAb. The results indicate that DDIAs with MoAbs against different blood group determinants and tumour associated antigens can improve the detection of circulating antigens in patients with early stage cancer.     

In vitro validation of an ultra‐sensitive scanning fluorescence microscope for analysis of Circulating Tumor Cells

Analysis of circulating tumor cells (CTC) holds promise of providing liquid biopsies from patients with cancer. However, current methods include enrichment procedures. We present a method (CytoTrack^®), where CTC from 7.5 mL of blood is stained, analyzed and counted by a scanning fluorescence microscope. The method was validated by breast cancer cells (MCF‐7) spiked in blood from healthy donors. The number of cells spiked in each blood sample was exactly determined by cell sorter and performed in three series of three samples spiked with 10, 33 or 100 cells in addition with three control samples for each series. The recovery rate of 10, 33 and 100 tumor cells in a blood sample was 55%, 70% and 78%, percent coefficient of variation (CV%) for samples was 59%, 32% and 18%, respectively. None of the control samples contained CTC. In conclusion, the method has been validated to highly sensitively detect breast cancer cells in spiking experiments and should be tested on blood samples from breast cancer patients. The method could benefit from automation that could reduce the CV%, and further optimization of the procedure to increase the recovery.     

Isolated tumor cells and circulating CK20 mRNA in pN0 colorectal cancer patients

Micrometastases in lymph nodes and blood may provide important prognostic information. In this study, cytokeratin 20 (CK20) positive cells in lymph nodes and circulating CK20 mRNA were studied using 57 paraffin-embedded lymph node specimens and blood from 24 patients with pN0 colorectal cancer (CRC), respectively. Results showed that 29 out of 56 (52%) lymph node specimens had CK20-positive cells (range: 1-35). Follow-up of the patients for 12 months indicated that 4 patients (7%) had CRC metastases to liver, lung, and bone. In addition, 8 out of 24 (33%) samples had at least 2-fold circulating CK20 mRNA expression higher than the pooled normal sample. This study provides evidence that CK20-positive cells were found in the lymph nodes and differentially expressed circulating CK20 mRNA was also detected in the blood from patients with pN0 CRC. Long-term follow-up is necessary to study their prognostic use in patients with non-metastatic CRC.     

Circulating CD137+CD8+ T cells accumulate along with increased functional regulatory T cells and thoracic tumour burden in lung cancer patients

CD137 is a promising target for immunostimulation strategies against cancer. Previous studies showed that CD137⁺CD8⁺ T cells are enriched in antitumour effector T cells in both preclinical tumour models and cancer patients, but to date, such T cells in the blood of lung cancer patients have not been sufficiently investigated. In this study, circulating antigen‐activated CD8⁺ T cell subsets, identified as CD137⁺CD8⁺ or PD‐1⁺ (programmed cell death protein 1) CD8⁺, and regulatory T cells (Treg), identified as CD4⁺CD25⁺CD127^low/?, in 40 untreated lung cancer patients and in 49 age‐ and sex‐matched healthy controls (HCs) were assessed by flow cytometry. Results were evaluated for associations with lung cancer patient clinical characteristics. Correlations between antigen‐activated CD8⁺ T cells and effector Treg (CTLA‐4⁺ [cytotoxic T‐lymphocyte antigen 4] CD4⁺CD25⁺CD127^low/?) were also investigated. Higher percentages of PD‐1⁺, CD137⁺ and PD‐1⁺CD137⁺ amongst CD8⁺ T cells were observed in lung cancer patients compared with HCs. The percentages of CD137⁺CD8⁺ and PD‐1⁺CD137⁺CD8⁺ T cell subsets amongst CD8⁺ T cells were positively correlated with thoracic tumour burden and were strongly positively correlated with the percentage of effector Treg subset. Smoking patients harboured higher percentages of the PD‐1⁺CD8⁺ T cell subset compared with non‐smoking patients. This study demonstrated that circulating antigen‐activated CD8⁺ T cells accumulated in lung cancer patients along with increased effector Treg and thoracic tumour burden. These findings aid a better understanding of immune‐host interactions in lung cancer patients using peripheral blood, and further support immunotherapeutic intervention strategies using combination therapy for differential control of Treg and activation of tumour‐specific effector T cells.     

Cancer stem cell marker CD133+ tumour cells and clinical outcome in rectal cancer

Aims:  The CD133 antigen has been identified as a putative stem cell marker in colorectal cancer tissues. According to the cancer stem cell hypothesis, CD133+ cells determine long-term tumour growth and are therefore suspected of influencing clinical outcome. The aim was to investigate the prognostic value of CD133 expression in rectal cancer patients after preoperative radiation and curative resection.
Methods and results:  The expression of the CD133 stem cell antigen in a series of 73 patients with rectal cancer of various ypTNM stages was analysed by immunohistochemistry on formalin-fixed paraffin-embedded sections. The prognostic value of CD133 expression and other clinicopathological factors was evaluated. On multivariate survival analysis, the proportion of CD133+ cells was a significant ( P  < 0.05) prognostic factor for adverse disease-free survival and overall survival independent of ypTNM stage, tumour differentiation or lymphovascular invasion.
Conclusions:  CD133 stem cell antigen expression correlates with patient survival in rectal cancer, lending support to the current cancer stem cell hypothesis.     

胃癌患者外周血中CK20 mRNA的检测及其临床意义

目的:检测胃癌患者外周血中CK20 mRNA的表达情况,并探讨其存在的临床意义.方法:应用逆转录聚合酶链反应,检测66例胃癌、良性胃病患者38例及对照组40例外周血中的表达.结果:对照组40例及良性胃病组38例外周血中CK20 mRNA均为阴性表达.胃癌组外周血中阳性表达率为34.8%,胃癌患者外周血中的阳性表达率与肿瘤组织学类型、TNM分期具有相关性(P＜0.05),与肿瘤的部位、病人性别无明显相关性(P＞0.05).手术后复查阳性表达率上升为60%,系手术操作所致.结论:胃癌患者外周血中的阳性表达可作为肿瘤细胞血行播散的标志,有助于胃癌预后的判断.手术操作可促使肿瘤细胞释放入血,胃癌手术中应采用"不接触肿瘤的游离技术"以减少癌细胞的播散.     

Expression of mucins (MUC1, MUC2, MUC5AC,and MUC6) and type 1 Lewis antigens in cases with and without Helicobacter pylori colonization in metaplastic glands of the human stomach

Dendritic cells (DCs) take up tumour-specific antigen and migrate to regional lymph nodes to generate anti-tumour immunity. Although DC infiltration within human tumour tissue has been reported, the subset distribution has not been fully investigated. This study used immunohistochemistry to investigate DC subset distribution in colorectal adenocarcinoma. DCs expressing CD83, which are considered to be mature DCs, were present mainly in the invasive margin of cancer stroma. CD83(+) DCs in the invasive margin formed clusters with lymphocytes, the majority of which were CD45RO(+) T cells. The number of CD4(+) T cells was greater than that of CD8(+) T cells in these DC-lymphocyte clusters. The elongated cytoplasmic processes of CD83(+) DCs engulfed CD4(+) T cells. DCs that express CD1a were located throughout tumour tissue. Although the number of CD1a(+) DCs was almost the same as that of CD83(+) DCs in the invasive margin of cancer stroma, CD1a(+) DCs were mostly scattered and rarely formed clusters with lymphocytes. DCs that expressed both CD1a and CD83 were rare. Moreover, about 20% of lymphocytes in DC-lymphocyte clusters were positive for Ki-67, and CD83(+) DCs were attached to Ki-67(+) cells. CD83(+) DCs were also present in T-cell areas that had a distinctive structure involving the presence of B-cell lymphoid follicles. These results suggest that in the invasive margin of the colorectal cancer stroma, mature CD83(+) DCs form clusters with T cells to promote T-cell activation for the generation of tumour-specific immunity.     

Expression of CD176 (Thomsen-Friedenreich antigen) on lung, breast and liver cancer-initiating cells

The cancer-initiating capacity of most malignant tumours is considered to reside in a small subpopulation of cells. Therapeutical interventions should target these cells rather than the tumour mass. Numerous studies have shown that the carbohydrate antigen structure CD176 (Thomsen-Friedenreich antigen, core-1) is present in many types of cancer and absent in normal adult human tissues. In this study, we assessed whether CD176 is co-expressed with CD44 or CD133 [markers of cancer-initiating cells (CIC)] in human lung, breast and liver carcinoma. A variety of human cancer cell lines and surgical specimens of these malignancies were examined. It was found that in most cases the majority of tumour cells stained strongly for CD44 by immunohistochemistry and flow cytometry, whereas CD133 expression was found on a smaller, but varying proportion of cells. Co-expression of CD176 with CD44 was found at a surprisingly high percentage of cancer cells in vitro and in vivo. Co-expression of CD176 with CD133 was also detected, although at a lower rate. Tamoxifen treatment of MDA-435 breast cancer cells enhanced the CD44(+) /CD176(+) phenotype. Evidence is provided through a new sandwich solid-phase enzyme-linked immunosorbent assay (ELISA) suggesting that CD44 is a carrier molecule for CD176 not only in colorectal cancer as previously reported, but also in lung, breast and liver cancer. The expression of CD176 in CIC suggests that it may represent an effective target for tumour therapies.