NPM-ALK: A Driver of Lymphoma Pathogenesis and a Therapeutic Target

Initially discovered in anaplastic large cell lymphoma (ALCL), the ALK anaplastic lymphoma kinase is a tyrosine kinase which is affected in lymphomas by oncogenic translocations, mainly NPM-ALK. To date, chemotherapy remains a viable option in ALCL patients with ALK translocations as it leads to remission rates of approximately 80%. However, the remaining patients do not respond to chemotherapy and some patients have drug-resistant relapses. It is therefore crucial to identify new and better treatment options. Nowadays, different classes of ALK tyrosine kinase inhibitors (TKI) are available and used exclusively for EML4-ALK (+) lung cancers. In fact, the significant toxicities of most ALK inhibitors explain the delay in their use in ALCL patients, who are predominantly children. Moreover, some ALCL patients do not respond to Crizotinib, the first generation TKI, or develop an acquired resistance months following an initial response. Combination therapy with ALK inhibitors in ALCL is th..... READ ARTICLE

Cancers (Basel) DOI:10.3390/cancers13010144

Authors: Elissa Andraos, Joséphine Dignac, Fabienne Meggetto

The Transcriptional Roles of ALK Fusion Proteins in Tumorigenesis

Anaplastic lymphoma kinase (ALK) is a tyrosine kinase involved in neuronal and gut development. Initially discovered in T cell lymphoma, ALK is frequently affected in diverse cancers by oncogenic translocations. These translocations involve different fusion partners that facilitate multimerisation and autophosphorylation of ALK, resulting in a constitutively active tyrosine kinase with oncogenic potential. ALK fusion proteins are involved in diverse cellular signalling pathways, such as Ras/extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K)/Akt and Janus protein tyrosine kinase (JAK)/STAT. Furthermore, ALK is implicated in epigenetic regulation, including DNA methylation and miRNA expression, and an interaction with nuclear proteins has been described. Through these mechanisms, ALK fusion proteins enable a transcriptional programme that drives the pathogenesis of a range of ALK-related malignancies. READ ARTICLE

Cancers (Basel) DOI:10.3390/cancers11081074

Authors: Stephen P Ducray, Karthikraj Natarajan, Gavin D Garland, Suzanne D Turner, Gerda Egger

EditorialKirk SmithJuly 30, 2019ALCL, ALK, ALK-translocation proteins, EML4-ALK, NPM-ALK, NSCLC, epigenetics

The biology and management of systemic anaplastic large cell lymphoma

Systemic anaplastic large cell lymphoma (ALCL) is an aggressive CD30+ non-Hodgkin lymphoma. Anaplastic lymphoma kinase–positive (ALK+) ALCL is associated with the NPM-ALK t(2;5) translocation, which is highly correlated with the identification of the ALK protein by immunohistochemistry. ALK+ ALCL typically occurs in younger patients and has a more favorable prognosis with 5-year survival rates of 70% to 90% in comparison with 40% to 60% for ALK-negative (ALK−) ALCL. Studies support young age as a strong component of the favorable prognosis of ALK+ ALCL. Until recently, no recurrent translocations were identified in ALK− ALCL. However, emerging data now highlight that ALK− ALCL is genetically and clinically heterogeneous with a subset having either a DUSP22 translocation and a survival rate similar to ALK+ ALCL or a less common P63 translocation, the latter associated with an aggressive course. Anthracycline-based regimens such as cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) remain the standard first-line treatment choice for systemic ALCL, but in many patients with ALK− ALCL, it is ineffective, and thus it is often followed by consolidative autologous stem cell transplantation. However, selection of appropriate patients for intensified therapy remains challenging, particularly in light of genetic and clinical heterogeneity in addition to the emergence of new, effective therapies. The antibody drug conjugate brentuximab vedotin is associated with a high response rate (86%) and durable remissions in relapsed/refractory ALCL and is under investigation in the first-line setting. In the future, combining clinical and genetic biomarkers may aid in risk stratification and help guide initial patient management. READ ARTICLE

Blood DOI: 10.1182/blood-2014-10-567461

Authors: Greg Hapgood, Kerry J. Savage