Anaplastic Lymphoma Kinase (ALK)

Systemic anaplastic large cell lymphoma (ALCL) is a distinct disease classification provisionally sub-divided into ALCL, Anaplastic Lymphoma Kinase (ALK)(+) and ALCL, ALK(-) entities. More recently, another category of ALCL has been increasingly reported in the literature and is associated with the presence of breast implants. A comprehensive review of the 71 reported cases of breast implant associated ALCL (iALCL) is presented indicating the apparent risk factors and main characteristics of this rare cancer. The average patient is 50 years of age and most cases present in the capsule surrounding the implant as part of the periprosthetic fluid or the capsule itself on average at 10 years post-surgery suggesting that iALCL is a late complication. The absolute risk is low ranging from 1:500,000 to 1:3,000,000 patients with breast implants per year. The majority of cases are ALK-negative, yet are associated with silicone-coated implants suggestive of the mechanism of tumorigenesis which is discussed in relation to chronic inflammation, immunogenicity of the implants and sub-clinical infection. In particular, capsulotomy alone seems to be sufficient for the treatment of many cases suggesting the implants provide the biological stimulus whereas others require further treatment including chemo- and radiotherapy although reported cases remain too low to recommend a therapeutic approach. However, CD30-based therapeutics might be a future option.

Sorbonne Université (Pierre & Marie Curie, Paris VI), Faculty of Sciences. N° national de thèse: 2006PA066115 https://www.worldcat.org/search?q=no%3A494198160 During development of the nervous system, Receptors with Tyrosine Kinase (RTK) activity play essential roles in a wide variety of fundamental physiological cellular processes such as proliferation, survival, or differentiation. In the RTK family, Alk has been one of the last to be identified. It remains, to date, considered as orphan, as no ligand has been yet attributed in vertebrates. It is essentially expressed in specific regions of the central and peripheral nervous system, and transiently during development. This expression strongly suggests therefore that it could play a fundamental role in the development and functioning of the nervous system. This role still remains however to be clearly identified. Thus, the studies I conducted these last years participate to the general understanding of the role of ALK in neuronal development. My thesis works focused therefore on the study of its function and mechanisms of action, in the frame of the neuronal differentiation of PC12 cells. These works also attempted, more generally, to bring matter to the current thoughts concerning the biochemical/cellular factors and parameters that can determine the specificity of biological responses and their cellular mechanisms of action. Specifically, they focused on the study of the role of the subcellular localization of a Tyrosine Kinase domain (of ALK, in particular) in the orchestration of the signals that determine neuronal development. Therefore, the results I obtained during this thesis, in their whole, have allowed not only to better understand the signalling pathways and the biological effects induced by the activation of the receptor ALK, but they further strongly support that membrane attachment of the ALK Tyrosine Kinase domain is crucial for the control and specificity of the signalling and biological pathways engaged by ALK. Thus, these works, more generally, underline the fundamental importance of the subcellular localization of a Tyrosine Kinase domain in the decision of the fate in which the cell will be engaged, and in particular the immature neuronal cell during the development of the nervous system.

BackgroundAnaplastic lymphoma kinase-positive diffuse large B-cell lymphoma (ALK-DLBCL) is a rare lymphoma with several clinicopathological differences from ALK-positive anaplastic large cell lymphoma (ALCL). The latest WHO classification of lymphomas recognizes ALK-DLBCL as a separate entity.MethodsA comprehensive comparison was made between the clinical and pathological features of the 4 cases reported and those found in an extensive literature search using MEDLINE through December 2008.ResultsIn our series, three cases were adults and one was pediatric. Two cases had primary extranodal disease (multifocal bone and right nasal fossa). Stages were I (n = 1), II (n = 1), III (n = 1) and IV (n = 1). Two cases had increased LDH levels and three reported B symptoms. IPI scores were 0 (n = 1), 2 (n = 2) and 3 (n = 1). All cases exhibited plasmablastic morphology. By immunohistochemistry, cases were positive for cytoplasmic ALK, MUM1, CD45, and EMA; they marked negative for CD3, CD30 and CD20. Studies for EBV and HHV-8 were negative. The survival for the patients with stage I, II, III and IV were 13, 62, 72 and 11 months, respectively.ConclusionALK-DLBCL is a distinct variant of DLBCL with plasmacytic differentiation, which is characterized by a bimodal age incidence curve, primarily nodal involvement, plasmablastic morphology, lack of expression of CD20, aggressive behavior and poor response to standard therapies, although some cases can have prolonged survival as the cases reported in this study. ALK-DLBCL does not seem associated to immunosuppression or the presence of EBV or HHV8. Further prospective studies are needed to optimize therapies for this entity.

Oncogenic rearrangements of the tyrosine kinase receptor anaplastic lymphoma kinase (ALK), most commonly represented by the nucleophosmin/ALK fusion protein (NPM/ALK), are involved in the pathogenesis of anaplastic large-cell lymphomas (ALCLs). In an effort to identify new intracellular transducers operative in ALK-positive malignancies, we have investigated the potential involvement of diacylglycerol kinase (DGK). Here we show that alphaDGK is constitutively activated in the NPM/ALK-positive ALCL-derived cell line Karpas 299 and in NPM/ALK-infected 32D hematopoietic cells. These results were further validated in fibroblastic NIH-3T3 cells expressing a previously described chimeric epidermal growth factor receptor (EGFR)/ALK molecule that allows dissection of ALK enzymatic function under conditions of controlled ligand-induced activation. In this cell system, we also show that ALK-mediated alphaDGK activation is dependent on p60src tyrosine kinase, with which alphaDGK forms a comple...

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase that is transiently expressed in specific regions of the central and peripheral nervous systems, suggesting a role in its normal development and function. The nature of the cognate ligands of ALK in vertebrate is still a matter of debate. We produced a panel of monoclonal antibodies (mAbs) directed against the extracellular domain of the human receptor. Two major species of ALK (220 and 140 kDa) were identified in transfected cells, and the use of our mAbs established that the 140-kDa species results from a cleavage of the 220-kDa form. Two mAbs, in the nm range, induced the differentiation of PC12 cells transiently transfected with ALK. In human embryonic kidney 293 cells stably expressing ALK, these two mAbs strongly activated the receptor and subsequently the mitogen-activated protein kinase pathway. We further showed for the first time that activation of ALK also resulted in a specific activation of STAT3. In contrast, other mAbs presented the characteristics of blocking antibodies. Finally, in these cell systems, a mitogenic form of pleiotrophin, a proposed ligand of ALK, failed to activate this receptor. Thus, in the absence of clearly established ligand(s) in vertebrates, the availability of mAbs allowing the activation or the inhibition of the receptor will be essential for a better understanding of the biological roles of ALK.

Chemokine receptors mediate the migration of lymphocytes through the binding of soluble ligands, and their expression is differentially regulated in lymphocyte subsets. The pattern of chemokine receptor expression in T-cell non-Hodgkin lymphoma has not been previously studied. Using a panel of mouse monoclonal antibodies, we studied the immunohistochemical expression of the Th1-associated chemokine receptor CXCR3 in 141 patients with T-cell lymphoma, and we studied the receptors CCR4 and CCR5 and some of their ligands in a subset of these tumors. Expression of CXCR3 was typical of the smaller T cells in angioimmunoblastic lymphoma (15 of 18 patients), angiocentric lymphoma (3 of 3 patients), histiocyte-rich tumors (4 of 5 patients), and unspecified T-cell lymphomas (17 of 39 patients). CXCR3 expression was seen in only 1 of 15 patients with anaplastic lymphoma kinase (ALK)-positive anaplastic large-cell lymphoma. In contrast, all ALK-positive tumors showed diffuse reactivity for the...

Primary Cutaneous Anaplastic Large‑cell Lymphoma (PC‑ALCL) is the second most common cutaneous T‑cell Lym‑
phoma. PCALCL is composed of large cells with an anaplastic, pleomorphic, or immunoblastic cytomorphology, and
expression of the CD30 antigen by the majority (>75%) of tumor cells .Wehere by report a case of unusually aggressive
PC‑ALCL in a young adult.

Here, we report an unusual case of gastric anaplastic large cell lymphoma (ALCL), lymphohistiocytic variant, in a 70-year-old female patient who presented with epigastric pain, tarry stool and body weight loss. Endoscopic and imaging findings revealed a Bormann type II tumor in the stomach with perigastric lymphadenopathy and multiple tumor nodules in the liver. Total gastrectomy and liver biopsy were performed. Histologically, both gastric and hepatic tumors demonstrated anaplastic large neoplastic cells scattered among numerous reactive histiocytes. Immunostaining of these tumor cells reacted positively for CD30, CD3, CD45RO/UCHL1, and negatively for epithelial membrane antigen, CD68, lysozyme, CD15, CD79a, CD138, PAX5 and anaplastic lymphoma kinase. Both the morphologic and immunophenotypic findings supported the diagnosis of gastric ALCL of lymphohistiocytic variant with liver metastasis. This patient then received chemotherapy and was still alive after 17 months of follow-up, without evidence of residual disease.