Le(y) glycolipid acts as a co-factor for tumor procoagulant activity

An integrated computational and experimental study uncovers FUT9 as a metabolic driver of colorectal cancer

Metabolic alterations play an important role in cancer and yet, few metabolic cancer driver genes are known. Here we perform a combined genomic and metabolic modeling analysis searching for metabolic drivers of colorectal cancer. Our analysis predicts FUT9, which catalyzes the biosynthesis of Ley glycolipids, as a driver of advanced-stage colon cancer. Experimental testing reveals FUT9's complex dual role; while its knockdown enhances proliferation and migration in monolayers, it suppresses colon cancer cells expansion in tumorspheres and inhibits tumor development in a mouse xenograft models. These results suggest that FUT9's inhibition may attenuate tumor-initiating cells (TICs) that are known to dominate tumorspheres and early tumor growth, but promote bulk tumor cells. In agreement, we find that FUT9 silencing decreases the expression of the colorectal cancer TIC marker CD44 and the level of the OCT4 transcription factor, which is known to support cancer stemness. Beyond its current application, this work presents a novel genomic and metabolic modeling computational approach that can facilitate the systematic discovery of metabolic driver genes in other types of cancer.

Cell-in-cell structures formed between human cancer cell lines and the cytotoxic regulatory T-cell line HOZOT

We previously established a novel cell line, termed HOZOT, derived from umbilical cord blood mononuclear cells that is characterized as a human cytotoxic regulatory T (Treg) cell line with a FOXP3(+)CD4(+)CD8(+)CD25(+) phenotype. Here, we describe a new property of HOZOT cells: they actively penetrate into a variety of human cancer cell lines, but not into normal cell lines, and form apparent cell-in-cell structures. In the process of cell penetration, we observed that HOZOT cells adhered to target cells seemed to first insert their nuclei into the cytoplasm of target cells, distinct from the process of phagocytosis. In addition, blocking experiments showed that major histocompatibility complex class I is one of the target cell recognition molecules for HOZOT cells. Furthermore, we propose that cell-in-cell structures between HOZOT cells and target cancer cells could be one of the cytotoxic mechanisms of HOZOT cells.

ABH and Lewis histo-blood group antigens, a model for the meaning of oligosaccharide diversity in the face of a changing world

Antigens of the ABH and Lewis histo-blood group family have been known for a long time. Yet their biological meaning is still largely obscure. Based on the available knowledge about the genes involved in their biosynthesis and about their tissue distribution in humans and other mammals, we discuss here the selective forces that may maintain or propagate these oligosaccharide antigens. The ABO, alpha 1,2fucosyltransferase and alpha 1,3fucosyltransferase enzyme families have been generated by gene duplications. Members of these families contribute to biosynthesis of the antigens through epistatic interactions. We suggest that the highly polymorphic genes of each family provide intraspecies diversity that allows coping with diverse and rapidly evolving pathogens. In contrast, the genes of low frequency polymorphism are expected to play roles at the cellular level, although they may be dispensable at the individual level. In addition, some members of these three gene families are expected to be functionally redundant and may either provide a reservoir for additional diversity in the future or become inactivated. We also discuss the role of the ABH and Lewis histo-blood group antigens in pathologies such as cancer and cardiovascular diseases, but argue that it is merely incidental and devoid of evolutionary impact.

ABH and Lewis histo-blood group antigens in cancer

Antigens of the ABH and Lewis histo-blood group family can be found on many normal cells, mainly of epithelial type. In carcinomas, altered expression of the various carbohydrate epitopes of this family occur, and are often strongly associated with either a good or bad prognosis. A review of the available data on these tumor-associated markers, their biosynthesis and their prognostic value is proposed here. For a long time it has been unclear whether their presence could affect the behavior of carcinoma cells. Recent data, however, indicate that they play biological roles in the course of tumor progression. The presence of sialyl-Le(a) or sialyl-Le(x), which are ligands for selectins, promotes the metastatic process by facilitating interaction with the endothelium of distant organs. The loss of A and B antigens increases cellular motility, while the presence of H epitopes increases resistance to apoptosis by mechanisms that remain to be defined. The Le(y) antigen has procoagulant and angiogenic activities. All these observations are used to present a model that may account for the described associations between the presence or loss of these markers and the outcome of disease. Finally, their potential clinical applications as tumor-associated markers or as targets of immunotherapy are reviewed.

Changes of the coagulation and fibrinolysis system in malignancy: their possible impact on future diagnostic and therapeutic procedures

The interaction between malignant cell growth and the coagulation and fibrinolysis system has been a well known phenomenon for decades. During recent years, this area of research has received new attention. Experimental data suggest a role for the coagulation and fibrinolysis system in tumor development, progression and metastasis. Also, clinical research suggests that targeting the coagulation system or fibrinolysis system might influence the course of malignant disease beneficially. This paper reviews data on various hemostatic and fibrinolytic parameters in malignancy; the possible use of such parameters as risk markers in oncology patients; and possible targets of anti-neoplastic therapies using anticoagulant and/or antifibrinolytic strategies. Current evidence suggests that the tissue factor/factor VIIa pathway mediates the most abundant procoagulant stimulus in malignancy via the increase in thrombin generation. Tissue factor has been suggested to mediate pro-metastatic properties via coagulation-dependent and coagulation-independent pathways; tissue factor has also been implicated in tumor neo-angiogenesis. However, so far no model has been validated that would allow the use of tissue factor in its soluble or insoluble form as a marker for risk stratification in tumor patients. On the other hand, there is now good evidence that parts of the fibrinolytic system, such as urokinase-type plasminogen activator and its receptor ("uPAR"), can be used as strong predictors of outcome in several types of cancer, specifically breast cancer. Observation of various treatment options in patients with thromboembolic disease and cancer as well as attempts to use anticoagulants and/or therapies modulating the fibrinolytic system as anti-neoplastic treatment strategies have yielded exciting results. These data indicate that anticoagulant therapy, and specifically low molecular weight heparin therapy, is likely to have anti-neoplastic effects; and that their use in addition to chemotherapy will probably improve outcome of tumor treatment in certain types of cancer. However, the body of clinical data is still relatively small and the question whether or not we should routinely consider the coagulation and/or fibrinolysis system as therapeutic targets in cancer patients is yet to be answered.

Breast cancer progression and expression of blood group-related tumor-associated antigens

There is sufficient evidence that blood group related Lewis antigens are tumor-associated molecules. We have conducted immunohistochemical analysis of the expression of Lewis antigens in breast cancer tissue as an indicator of the degree of malignancy and as a prognostic factor. The studies were performed by examining 43 female patients diagnosed with invasive ductal carcinoma of the breast. Postoperative specimens were stained immunohistochemically using a panel of monoclonal antibodies (MAbs) specific for tumor-associated antigens: sialosyl LewisA, LewisA, LewisB, Lewisx, and LewisY. The aims of the study were to compare the appearance of metastases, degree of cancer stage (pTNM), and its histologic differentiation with the expression of Lewis phenotype. The evaluation of antigen expression was performed quantitatively and independently by two pathologists. Statistical significance was defined by Mann-Whitney test. The presented analysis of Lewis antigens showed higher expression of LeB and LeA (p = 0.03) in patients in stage N2 than in stage N1. The expression of LeB and LeY was higher in patients in stage T4 than in stage T1 (p = 0.02). No differences were observed for histologic differentiation. These data suggest that the expression of sialosyl-LeA and LeB antigens in breast cancer may predict metastases to lymph nodes.