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Hypothesis Because of some inconsistencies in the traditional model of human colorectal carcinogenesis, the cancer stem cell (CSC) model was recently proposed, in which tumor results from neoplastic transformation of stem cells, which become CSCs. Identification of CSCs by expression of surface antigens remains a critical issue because no biomarker has been shown to be completely reliable. CD133 and CD44 are commonly used as CSC markers, and correlation of their expression with colorectal cancer (CRC) clinicopathological features and outcomes may be useful. Design Pilot study. Setting University hospital. Patients Thirty-six consecutive patients with CRC.CD133 and CD44 expression (alone or combined) was determined in nontumor cells and in tumor cells by flow cytometry, which identified viable cells only. Main Outcome Measures Correlation of CD133 and CD44 expression with each other, with other prognostic indicators, and with disease-free survival. Results CD133 and CD44 expression was significantly higher in tumor cells than in nontumor cells, and expression of one did not necessarily correlate with expression of the other. CD133 or CD44 expression alone was variable, while combined CD133/CD44 expression identified a small subset of cells positive for CRC. CD133 or CD44 overexpression was not associated with CRC recurrence; only high frequencies of CD133 + /CD44 + cells were a strong indicator of worse disease-free survival and an independent risk factor for CRC recurrence. Conclusion Evaluation of combined CD133/CD44 expression could be useful to identify putative colorectal CSCs and tumors with a poor prognosis.

The kinin B1 receptor plays a critical role in the chronic phase of pain and inflammation. The development of B1 antagonists peaked in recent years but almost all promising molecules failed in clinical trials. Little is known about these molecules&rsquo, mechanisms of action and additional information will be necessary to exploit the potential of the B1 receptor. With the aim of contributing to the available knowledge of the pharmacology of B1 receptors, we designed and characterized a novel class of allosteric non-peptidic inhibitors with peculiar binding characteristics. Here, we report the binding mode analysis and pharmacological characterization of a new allosteric B1 antagonist, DFL20656. We analyzed the binding of DFL20656 by single point mutagenesis and radioligand binding assays and we further characterized its pharmacology in terms of IC50, B1 receptor internalization and in vivo activity in comparison with different known B1 antagonists. We highlighted how different binding modes of DFL20656 and a Merck compound (compound 14) within the same molecular pocket can affect the biological and pharmacological properties of B1 inhibitors. DFL20656, by its peculiar binding mode, involving tight interactions with N114, efficiently induced B1 receptor internalization and evoked a long-lasting effect in an in vivo model of neuropathic pain. The pharmacological characterization of different B1 antagonists highlighted the effects of their binding modes on activity, receptor occupancy and internalization. Our results suggest that part of the failure of most B1 inhibitors could be ascribed to a lack of knowledge about target function and engagement.

NTRODUCTION: Circulating tumor cells are thought to play a crucial role in the development of distant metastases. Their detection in the blood of colorectal cancer patients may be linked to poor outcome, but current evidence is controversial. MATERIALS AND METHODS: Pre- and postoperative flow cytometric analysis of blood samples was carried out in 76 colorectal cancer patients undergoing surgical resection. The EpCAM/CD326 epithelial surface antigen was used to identify circulating tumor cells. RESULTS: Fifty-four (71%) patients showed circulating tumor cells preoperatively, and all metastatic patients showed high levels of circulating tumor cells. Surgical resection resulted in a significant decrease in the levels of circulating tumor cells. Among 69 patients undergoing radical surgery, 16 had high postoperative levels of circulating tumor cells, and 12 (75%) experienced tumor recurrence. High postoperative level of circulating tumor cells was the only independent variable related to cancer relapse. In patients without circulating tumor cells, the progression-free survival rate increased from 16 to 86%, with a reduction in the risk of tumor relapse greater than 90%. CONCLUSIONS: High postoperative levels of circulating tumor cells accurately predicted tumor recurrence, suggesting that assessment of circulating tumor cells could optimize tailored management of colorectal cancer patients.

Cancer stem cell characterization represents a breakthrough in cancer research. Despite evidence showing the existence and the role of cancer stem cells in osteosarcoma (OS) onset and progression, little is known about their specific surface phenotype. To address this issue, we carried out a cytometric analysis with an antibody-array comprising 245 membrane proteins comparing the stem and differentiated OS cells. As experimental model, we chose the stem-like cell line 3aminobenzamide-OS and its parental, differentiated, cell line MG63. We identified 50 differentially expressed, 23 homogeneously expressed, and 172 not expressed proteins in the two cell line models, thus defining a surface protein signature specific for each of them. Furthermore, we selected ERK1/2 (p44/42 mitogen-activated protein kinases) as a potential pathway correlated with processes that characterize tumorigenic potential and stemness of 3aminobenzamide-OS cells.

In colorectal cancer, CD133+ cells from fresh biopsies proved to be more tumorigenic than their CD133– counterparts. Nevertheless, the function of CD133 protein in tumorigenic cells seems only marginal. Moreover, CD133 expression alone is insufficient to isolate true cancer stem cells, since only 1 out of 262 CD133+ cells actually displays stem-cell capacity. Thus, new markers for colorectal cancer stem cells are needed. Here, we show the extensive characterization of CD133+ cells in 5 different colon carcinoma continuous cell lines (HT29, HCT116, Caco2, GEO and LS174T), each representing a different maturation level of colorectal cancer cells. Markers associated with stemness, tumorigenesis and metastatic potential were selected. We identified 6 molecules consistently present on CD133+ cells: CD9, CD29, CD49b, CD59, CD151, and CD326. By contrast, CD24, CD26, CD54, CD66c, CD81, CD90, CD99, CD112, CD164, CD166, and CD200 showed a discontinuous behavior, which led us to identify cell type-specific surface antigen mosaics. Finally, some antigens, e.g. CD227, indicated the possibility of classifying the CD133+ cells into 2 subsets likely exhibiting specific features. This study reports, for the first time, an extended characterization of the CD133+ cells in colon carcinoma cell lines and provides a “dictionary” of antigens to be used in colorectal cancer research.

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 (CD66cbright) in CD133-positive cells from colon cancer samples. In vitro experiments demonstrated that colon spheres were considerably enriched in a CD66cbright 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: CD66cbright 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.

The cancer stem cell (CSC) theory represents a breakthrough in cancer research. We characterized the protein pattern of CSCs to identify specific intracellular pathways in this subpopulation of tumor cells. We studied colon CSCs using two different colon cancer cell lines: CaCo-2 and HCT- 116. Putative CSCs were separated from non-CSCs by flow cytometry using CD133 as stemness marker. Total protein extracts of CD133+ cells were then compared to protein extracts of CD133- cells by 2D DIGE. The protein spots differentially expressed in the two subpopulation of cells were analyzed by mass spectrometry. Bioinformatics analysis of the identified proteins indicated alteration of two main processes: energy metabolism and the Wnt pathway. Interestingly, we observed up-regulation of the splicing factor SRp20, a newly identified target gene of the Wnt/??- catenin pathway, and we demonstrated a direct cause-effect relationship between Wnt pathway activation and the increased SRp20 expression. Our results also show that SRp20 influences cell proliferation, which suggests it plays a role in the tumorigenicity of CD133+ cells. In conclusion, activation of the Wnt pathway in CD133+ cells and up-regulation of SRp20, which is implicated in tumorigenesis, raises the possibility of a sequential series of molecular events occurring in connection with this process.

During the last decades, extended characterizations were performed of human full-term cord blood (hTCB) cells, but little information is available on human early preterm cord blood (hEPCB) hematopoietic stem cells (HSCs). In our study, we analyzed by flow cytometry 19 hEPCB and 17 hTCB samples. First, we observed that the percentage of CD34(Pos)CD45(Dim) cells was higher in hEPCB compared with hTCB and that it decreased during 16th-20th week of pregnancy. Within the CD34(Pos)CD45(Dim) population, we examined the expression of CD29, CD31, CD38, CD90, CD117, CD133, CD135, CD200, CD243, and CD338. We found that CD135 intensity and CD243(Pos) cells percentage were lower in hEPCB compared with hTCB. As to CD38, we observed that hEPCB samples were richer in undifferentiated CD34(Pos)CD45(Dim)CD38(Neg) HSCs compared with hTCB counterparts. We also compared the expression of the above-mentioned molecules in undifferentiated and committed HSCs residing in hEPCB and hTCB. In particular, although CD34(Pos)CD45(Dim)CD38(Pos) HSCs from both hEPCB and hTCB expressed relatively higher amounts of CD29, CD71, and CD135 compared with CD34(Pos)CD45(Dim)CD38(Neg) cells, a higher expression of CD31 was restricted to CD34(Pos)CD45(Dim)CD38(Pos) cells from hEPCB samples, and a higher expression of CD117 was demonstrated in CD34(Pos)CD45(Dim)CD38(Pos) cells from hTCB samples. Moreover, our data showed that CD34(Pos)CD45(Dim) cell population from hEPCB displayed higher percent of undifferentiated CD38(Neg)CD133(Pos) cells compared with hTCB samples. Finally, analyzing monocytes and lymphocytes within the two samples, we observed that T-cell percentages were higher in hTCB, whereas B-cell percentages were higher in hEPCB. We, therefore, studied the B-cell lineage maturation and found a higher percent of pro-B and pre-B cells in hEPCB compared with hTCB samples. Taken together, these results evidence the hematopoietic peculiarity of hEPCB, potentially useful for highlighting early steps of human hematolymphopoiesis as well as for developing novel strategies of stem cell-based therapy.

Background Mollicutes contamination is recognized to be a critical issue for the cultivation of continuous cell lines. In this work we characterized the effect of Mycoplasma hyorhinis contamination on CD133 expression in human colon cancer cell lines. Methods MycoAlert® and mycoplasma agar culture were used to detect mycoplasma contamination on GEO, SW480 and HT-29 cell lines. Restriction fragment length polymorphism assay was used to determine mycoplasma species. All cellular models were decontaminated by the use of a specific antibiotic panel (Enrofloxacin, Ciprofloxacin, BM Cyclin 1 and 2, Mycoplasma Removal Agent and MycoZap®). The percentage of CD133 positive cells was analyzed by flow cytometry on GEO, SW480 and HT-29 cell lines, before and after Mycoplasma hyorhinis eradication. Results Mycoplasma hyorhinis infected colon cancer cell lines showed an increased percentage of CD133+ cells as compared to the same cell lines rendered mycoplasma-free by effective exposure to antibiotic treatment. The percentage of CD133 positive cells increased again when mycoplasma negative cells were re-infected by Mycoplasma hyorhinis. Conclusions Mycoplasma hyorhinis infection has an important role on the quality of cultured human colon cancer cell lines giving a false positive increase of cancer stem cells fraction characterized by CD133 expression. Possible explanations are (i) the direct involvement of Mycoplasma on CD133 expression or (ii) the selective pressure on a subpopulation of cells characterized by constitutive CD133 expression. In keeping with United Kingdom Coordinating Committee on Cancer Research (UKCCCR) guidelines, the present data indicate the mandatory prerequisite, for investigators involved in human colon cancer research area, of employing mycoplasma-free cell lines in order to avoid the production of non-reproducible or even false data.

International audience; Transformation to acute myeloid leukemia (AML) is a known complication of myeloproliferative neoplasia (MPN). Recent studies reported the high incidence (53%) of JAK2 negative blasts from transformed JAK2V617F-MPN. We collected, by cell sorting, blast cells and mature cells (GRA) from total bone marrow (BM) of 34 patients newly diagnosed of secondary AML. At MPN diagnosis (PMF n = 18; PV n = 9; ET n = 7), JAK2 was mutated in 22 of 34 patients. Twenty of 22 JAK2V617F-MPN (91%) maintained the mutation in blasts and GRA after leukemic switch, while in 2 of 22 patients the selected compartments lost the mutation. Surprisingly we also found the first case of JAK2V617F-AML from a wild type (WT)-MPN. In contrast to the previous study, we conclude that JAK2V617F-MPN yields rarely (9%) a JAK2WT-AML and any JAK2-status modification/persistence involves always the entire BM during leukemic transformation.

Background Mortality is high in patients with esophageal carcinoma as tumors are rarely detected before the disease has progressed to an advanced stage. Here, we sought to isolate cell-free DNA released into the plasma of patients with esophageal carcinoma, to analyze copy number variations of marker genes in the search for early detection of tumor progression. Methods Plasma of 41 patients with esophageal carcinoma was prospectively collected before tumor resection and chemotherapy. Our dataset resulted heterogeneous for clinical data, resembling the characteristics of the tumor. DNA from the plasma was extracted to analyze copy number variations of the erbB2 gene using real-time PCR assays. Results The real-time PCR assays for erbB2 gene showed significant (P = 0.001) copy number variations in the plasma of patients with esophageal carcinoma, as compared to healthy controls with high sensitivity (80%) and specificity (95%). These variations in erbB2 were negatively correlated to the progression free survival of these patients (P = 0.03), and revealed a further risk category stratification of patients with low VEGF expression levels. Conclusion The copy number variation of erbB2 gene from plasma can be used as prognostic marker for early detection of patients at risk of worse clinical outcome in esophageal cancer.

// Francesca Puca 1 , Marianna Colamaio 1 , Antonella Federico 1 , Marica Gemei 2 , Nadia Tosti 1 , Andre Uchimura Bastos 1 , Luigi Del Vecchio 2 , Salvatore Pece 3 , Sabrina Battista 1 and Alfredo Fusco 1 1 Istituto di Endocrinologia ed Oncologia Sperimentale - CNR e/o Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita degli Studi di Napoli “Federico II”, Naples, Italy 2 CEINGE, Biotecnologie Avanzate, Naples, Italy 3 Istituto Europeo di Oncologia, Milan, Italy Correspondence: Alfredo Fusco, email: // Sabrina Battista, email: // Keywords : HMGA1, cancer stem cells, p53, colon carcinoma, NUMB Received : March 04, 2014 Accepted : April 16, 2014 Published : April 18, 2014 Abstract High-mobility group A1 (HMGA1) proteins are architectural chromatinic proteins, abundantly expressed during embryogenesis and in most cancer tissues, but expressed at low levels or absent in normal adult tissues. Several studies have demonstrated that HMGA1 proteins play a causal role in neoplastic cell transformation. The aim of this study was to investigate the role of these proteins in the control of cancer stem cells (CSCs), which have emerged as a preferred target in cancer therapy, because of their role in cancer recurrence. We observed that HMGA1 is overexpressed in colon tumour stem cell (CTSC) lines compared to normal and colon cancer tissues. We demonstrated that HMGA1 silencing in CTSCs increases stem cell quiescence and reduces self-renewal and sphere-forming efficiency (SFE). The latter, together with the upregulation and asymmetric distribution of NUMB, is indicative of the recovery of an asymmetric division pattern, typical of normal stem cells. We further found that HMGA1 transcriptionally regulates p53, which is known to control the balance between symmetric and asymmetric divisions in CSCs. Therefore, our data indicate a critical role for HMGA1 in regulating both self-renewal and the symmetric/asymmetric division ratio in CSCs, suggesting that blocking HMGA1 function may be an effective anti-cancer therapy.