Glycoengineering in cancer therapeutics: a review with fucose-depleted trastuzumab as the model.

Experimentally modified trastuzumab antibodies show increased cytotoxic potency when used with human effector cells against HER2-overexpressing human breast cancer cells in vitro and ex vivo. Furthermore, the superior efficacy of 'glycoengineered' trastuzumab has been confirmed in vivo utilizing a preclinical xenograft model of human HER2-amplified, trastuzumab-resistant human breast cancer. The increased cytotoxic potency coupled with other improvements are achieved by a seemingly modest change in trastuzumab's structure, that is, depletion of two α-L-fucose residues from trastuzumab's heavy chains. Fucose-free trastuzumab binds with much greater affinity to human natural killer cells. This improved binding induces much greater antibody-dependent cellular cytotoxicity against HER2-overexpressing cells. The pharmaceutical industry has recognized the advantages of fucose-free therapeutic antibodies and has developed technologies that aim to mass produce such antibodies for human use. Here, we summarize data from multiple academic and pharmaceutical laboratories highlighting fucose depletion of antibodies as a key strategy of glycoengineering in cancer therapeutics. We use fucose-depleted trastuzumab as a model to show the advantages of this new class of anticancer agents. We predict that these advantages will translate clinically into improved therapeutics for many patients including those with HER2-overexpressing neoplasms.

The emerging importance of α-L-fucose in human breast cancer: a review.

Breast cancer cells incorporate the simple sugar alpha-L-fucose (fucose) into glycoproteins and glycolipids which, in turn, are expressed as part of the malignant phenotype. We have noted that fucose is not simply a bystander molecule, but, in fact, contributes to many of the fundamental oncologic properties of breast cancer cells. Here, we summarize the evidence from us and others that fucose is necessary for key functions of neoplastic progression including hematogenous metastasis, tumor invasion through extracellular matrices including basement membranes and up-regulation of the Notch signaling system, with implications for epithelial-to-mesenchymal transition and activation of breast cancer stem cells. Additionally, certain breast cancer biomarkers are fucose-rich while a well-known marker of breast cancer progression, soluble E-selectin, is a known counter-receptor of fucosylated selectin ligands. We provide illustrative examples and supportive evidence drawn from work with human breast cancer cell lines in vitro as well as clinical studies with human pathologic material. And finally, we discuss evidence that fucose (or its absence) is central to the mechanisms of action of several experimental targeted therapies which may prove useful in breast cancer treatment. We propose that alpha-L-fucose is essential in order to construct first, the malignant and then the metastatic phenotype of many human breast cancers. This knowledge may inform the search for novel treatment approaches in breast cancer.

Systemic CD5+ MALT lymphoma: presentation with Waldenstrom syndrome.

We report a case of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in a 75-year-old woman with a neuropathy related to high levels of serum immunoglobulin M and a history of rheumatoid arthritis and polymyositis. The patient developed a mass in the right submandibular salivary gland, and this mass demonstrated histopathologic features that are typical of MALT lymphoma, including infiltrates of small monocytoid B cells in the epithelium (forming "lymphoepithelial lesions"), a reactive background of florid germinal center hyperplasia, and follicular colonization by the monocytoid B cells. Many plasma cells in the background expressed cytoplasmic immunoglobulin M lambda, matching the serum spike. Flow cytometric analysis confirmed the presence of clonal mature B cells; however, unlike most MALT lymphomas, these cells coexpressed dim CD5. Clinical staging revealed evidence of systemic distribution with documented disease involving the bone marrow, the lung, and a paratracheal lymph node. Analysis of this unusual systemic MALT lymphoma, and a comparison with similar examples from the literature, illuminates relationships among MALT lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, and Waldenstrom macroglobulinemia.

An unusual presentation of Teflon granuloma: case report and discussion.

For more than 25 years, Teflon was the most commonly used material for injection laryngoplasty. However, the incidence of Teflon granuloma and the consequent deterioration of glottic function ultimately led to the development of other injectable materials, and as a result, Teflon granulomas are no longer frequently encountered. We present a case of Teflon granuloma that was unusual in that (1) a long period of time had elapsed between the injection and the granuloma formation and (2) there was no change in the patient's glottic function.

Cell surface associated alpha-L-fucose moieties modulate human breast cancer neoplastic progression.

Glycosylation drives critical processes important for mammalian cell-cell and cell-matrix interactions. Alpha-L-fucose (alpha-L-f) is a key monosaccharide component of oligosaccharides that has been found to be overexpressed during tumor progression. Modification of cell surface fucosylation, we hypothesized, alters tumor cell phenotype and function at the end of the neoplastic progression cascade including tumor invasion. Alpha-L-fucosidase (alpha-L-fase) is a glycosidase that specifically removes (alpha-L-f) from oligosaccharide sites. We first verified the effectiveness of the alpha-L-fase to specifically decrease the level of alpha-L-f on the cell surface of several human breast cancer cell lines and also examined the recovery time for these cells to repopulate their surfaces. To investigate the potential effect of defucosylation on tumor functions, we studied the proliferation, and invasion in vitro of human breast cancer MDA-MB-231 cells as the representative cell model. We further examined several fucose-associated molecules previously shown to be involved in tumor progression, including CD44 and CD15 (Lewis X antigen). We found that alpha-L: -fase pretreatment significantly decreased the invasive capability of breast cancer cells. Deoxyfuconojirimycin (DFJ), a specific alpha-L: -fase inhibitor, reversed this effect. After fucosidase treatment, the level of both CD15 and CD44 were found to be reduced as measured by flow cytometry. alpha-L-fase treatment, further, did not affect tumor cell proliferation in vitro under identical experimental conditions. Gelatin zymography of conditioned media from tumor cells treated with alpha-L-fase demonstrated no change in MMP-2 activity while MMP-9 was significantly reduced. In summary, fucose containing glycans were found widely distributed on the cell surface of breast cancer cells and could be effectively removed by alpha-L-fase treatment. This decreased fucosylation, in turn, was seen to impair the interaction between tumor cells and extracellular matrices, and thus affected key cell functions modulating tumor invasion. Further elucidation of the molecular pathways involved in the inhibition of tumor cell invasion may suggest a rationale for the use of glycobiologic therapeutics to deter tumor progression.

Alterations in human breast cancer adhesion-motility in response to changes in cell surface glycoproteins displaying alpha-L-fucose moieties.

Glycosylation of proteins plays multiple roles in cell-cell and cell-matrix interactions. Fucose is a monosaccharide associated with glycosylation events and is known to be over-expressed in many malignant tumors. By using alpha-L-fucosidase (alpha-L-fase), a glycosidase that specifically removes alpha-L-fucose (alpha-L-f), we have examined the potential effects of defucosylation on tumor functions, focusing on tumor progression in the context of the interaction of tumor cells with the extracellular microenvironment. In this submission, we report that alpha-L-fase treatment decreases, in static assays, tumor cell adhesion to a wide variety of ECM components including fibronectin, laminin, collagen I, hyaluronic acid and the complex human biomatrix, HuBiogel(R). By immunofluorescence, co-localization of beta1 integrin and alpha-L-f was found to decrease accordingly. Sialyl Lewis X, an alpha-L-f-containing tetrasaccharide, which modulates the rolling of leukocytes and tumor cells on endothelium, was found to be diminished on human breast cancer cells after alpha-L-fase treatment. Using a dynamic flow chamber system, we were able to determine that defucosylation impaired the rolling of mammary cancer cells on human umbilical vein endothelial cells while significantly increasing their flow speed. Further, the rolling capability of these defucosylated tumor cells was also impaired on purified E and P-selectin matrices. Based on these data, we hypothesize that decreased fucosylation impairs the interaction between tumor cells and their external milieu, which in turn, affects key cell functions modulating tumor progression. Building on our previous studies which demonstrated alpha-L-fase decreased tumor cell invasion while significantly reducing MMP-9 activity, when added to the fact that decreased adhesion on HUVEC occurs in the presence of alpha-L-fase also leads us to propose that defucosylation may modulate metastasis, and thus provides a promising additional glycobiotic target for novel therapies.

An intriguing case: malignant mesothelioma presenting as inguinal lymph node metastases.

A 56-year-old woman presented with a right inguinal mass. Biopsy revealed multiple lymph nodes involved with papillary and gland-like structures extending into the surrounding fibroadipose tissue. There was no history of carcinoma or other malignancy. Ultrastructural findings included long microvilli, desmosomes, and tonofilament bundles, indicating metastatic malignant mesothelioma. Malignant mesothelioma only rarely presents as a lymph node metastasis, and electron microscopy is very useful in establishing this diagnosis.

Multiple Langerhans cell nodules in an incidental thymectomy.

The isolated appearance of Langerhans cell histiocytosis in the thymus is quite rare. We report the finding of multiple small Langerhans cell nodules in the thymus of an 11-month-old infant who had undergone thymectomy in the course of surgical correction of tetralogy of Fallot. The subtle appearance of some of these nodules and aggregates was unlike the pattern of massive thymic infiltration seen in 7 previously reported cases of thymic Langerhans cell histiocytosis in childhood. This difference led us to consider whether these aggregates might be common in the thymus but overlooked in thymus glands removed incidental to cardiac surgery. We examined histologic material from 22 sequential thymectomy specimens removed during cardiac surgery from infants and children. None (0/22) had cohesive aggregates of Langerhans cells, as were seen in the index patient's thymus. Our patient's small thymic nodules resemble more closely a pattern found in adult patients with myasthenia gravis who have been incidentally shown to have Langerhans cell histiocytosis.

Composite mycosis fungoides and B-cell chronic lymphocytic leukemia.

Concordant or composite mycosis fungoides and B-cell chronic lymphocytic leukemia (B-CLL) is exceedingly rare, with only 10 cases previously described to our knowledge. We report a case of a 64-year-old woman who developed generalized erythroderma 5 years after the diagnosis of early stage B-CLL. Over the next 6 years of her clinical course multiple sequential samples of skin, peripheral blood, and one enlarged lymph node were studied in detail by flow cytometry, immunohistochemistry, molecular diagnostics, and electron microscopy. The progressive cutaneous infiltrates were initially characterized as leukemia cutis, infiltration by B-CLL. Three years later, when she developed worsening skin disease and lymphadenopathy, the cutaneous infiltrates were characterized as cutaneous T-cell lymphoma. At that point, a biopsy of an enlarged lymph node revealed a composite lymphoma of both B-CLL and cutaneous T-cell lymphoma, and the peripheral blood also contained circulating cells of both neoplasms. Herein we summarize the literature on concordant cutaneous T-cell lymphoma and B-CLL, and the literature on concordant T- and B-cell neoplasms in general, with a review of the postulated relationships between these neoplasms.

A practical approach to the diagnosis of Hodgkin lymphoma.

The diagnosis of Hodgkin lymphoma has become more difficult in recent years, paradoxically because of great strides made in the understanding of the molecular mechanisms driving the lymphomas. Extensive panels of monoclonal antibodies, coupled with flow cytometric analyses and molecular diagnostic studies, have served to define more lymphoma subtypes that cannot be identified based on morphologic evidence alone. This overview is intended to provide useful criteria for the recognition of Hodgkin lymphoma and to recommend tools that will aid in separating Hodgkin lymphoma from a series of common benign and malignant look-alikes. The relationships among Hodgkin lymphoma, the B-cell non-Hodgkin lymphomas, and the T-cell non-Hodgkin lymphomas are discussed, and useful immunohistochemical markers for the routine diagnosis of Hodgkin lymphoma are suggested.