Inhibition of anaplastic lymphoma kinase (ALK) activity provides a therapeutic approach for CLTC-ALK-positive human diffuse large B cell lymphomas

ALK positive diffuse large B-cell lymphomas (DLBCL) are a distinct lymphoma subtype associated with a poor outcome. Most of them feature a t(2;17) encoding a clathrin (CLTC)-ALK fusion protein. The contribution of deregulated ALK-activity in the pathogenesis and maintenance of these DLBCLs is not yet known. We established and characterized the first CLTC-ALK positive DLBCL cell line (LM1). LM1 formed tumors in NOD-SCID mice. The selective ALK inhibitor NVP-TAE684 inhibited growth of LM1 cells in vitro at nanomolar concentrations. NVP-TAE684 repressed ALK-activated signalling pathways and induced apoptosis of LM1 DLBCL cells. Inhibition of ALK-activity resulted in sustained tumor regression in the xenotransplant tumor model. These data indicate a role of CLTC-ALK in the maintenance of the malignant phenotype thereby providing a rationale therapeutic target for these otherwise refractory tumors.     

A patient death attributable to implant-related primary anaplastic large cell lymphoma of the breast

Implant-related primary anaplastic large cell lymphoma (ALCL) of the breast is a rare clinical entity. With increasing attention being paid to this disease, most cases reported to date in the literature have demonstrated indolent clinical courses responsive to explantation, capsulectomy, chemotherapy, and/or radiotherapy. The authors describe a case of bilateral implant-related primary ALCL of the breast that proved refractory to both standard and aggressive interventions, ultimately resulting in patient death secondary to disease progression. The authors situate this case in the context of the current state of knowledge regarding implant-related primary ALCL of the breast and suggest that this entity is generally, but not universally, indolent in nature. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, V.     

Spontaneous anaplastic large cell lymphoma in a chimpanzee: A clinicopathological and immunohistochemical study

Abstract: An anaplastic large cell lymphoma with disseminated abdominal metastases was diagnosed in a 35-year-old male chimpanzee. Clinically, the animal displayed lethargy, weight loss, ascites, and abdominal distention. Imaging studies showed several large abdominal masses. At necropsy, variably sized masses of neoplastic mesenteric lymph nodes that encompassed several intestinal loops were present throughout the abdomen. The largest mass measured 9 × 5 cm and had cauliflower-like protrusions into the jejunal lumen. The entire abdominal cavity was covered by a sheet of neoplastic tissue. Histopathologically, the tumor consisted of solid sheets of proliferating lymphoid cells forming a cohesive growth that filled the lymph node sinuses. The tumor had invaded the intestinal wall. Anaplastic large cell lymphoma was diagnosed from immunohistochemistry findings on the basis of positive reaction to the CD3 and CD30 markers and negative reaction to the CD20 marker. Serologic analysis revealed positive titers for Epstein-Barr, cytomegalo-, and varicella-zoster viruses. Both serologic and virologic studies showed no evidence of detectable retroviral infection. This type of tumor has not been reported before in the chimpanzee.     

The TRAF3 adaptor protein drives proliferation of anaplastic large cell lymphoma cells by regulating multiple signaling pathways

T cells devoid of tumor necrosis factor receptor associated factor-3 (Traf3) exhibit decreased proliferation, sensitivity to apoptosis, and an improper response to antigen challenge. We therefore hypothesized that TRAF3 is critical to the growth of malignant T cells. By suppressing TRAF3 protein in different cancerous T cells, we found that anaplastic large cell lymphoma (ALCL) cells require TRAF3 for proliferation. Since reducing TRAF3 results in aberrant activation of the noncanonical nuclear factor-κB (NF-κB) pathway, we prevented noncanonical NF-κB signaling by suppressing RelB together with TRAF3. This revealed that TRAF3 regulates proliferation independent of the noncanonical NF-κB pathway. However, suppression of NF-κB-inducing kinase (NIK) along with TRAF3 showed that high levels of NIK have a partial role in blocking cell cycle progression. Further investigation into the mechanism by which TRAF3 regulates cell division demonstrated that TRAF3 is essential for continued PI3K/AKT and JAK/STAT signaling. In addition, we found that while NIK is dispensable for controlling JAK/STAT activity, NIK is critical to regulating the PI3K/AKT pathway. Analysis of the phosphatase and tensin homolog (PTEN) showed that NIK modulates PI3K/AKT signaling by altering the localization of PTEN. Together our findings implicate TRAF3 as a positive regulator of the PI3K/AKT and JAK/STAT pathways and reveal a novel function for NIK in controlling PI3K/AKT activity. These results provide further insight into the role of TRAF3 and NIK in T cell malignancies and indicate that TRAF3 differentially governs the growth of B and T cell cancers.     

Cytomorphologic differentiation of Hodgkin's lymphoma and Ki-1+ anaplastic large cell lymphoma in fine needle aspirates

OBJECTIVE: To cytomorphologically differentiate Hodgkin's lymphoma (HL) from Ki-1+ anaplastic large cell lymphoma (ALCL) in fine needle aspirates. STUDY DESIGN: We blindly reviewed 63 fine needle aspiration (FNA) smears from histologically and immunophenotypically proven cases of ALCL (n = 15) and HL (n = 48). The smears were reviewed for the following criteria: (1) estimated percentages of abnormal cells, (2) pattern of the smears (polymorphous vs. dimorphous), and (3) presence or absence of multilobated cells. RESULTS: All cases were phenotyped by immunohistochemistry for CD3, CD15, CD20, CD30 and CD45, with flow cytometric immunophenotpyping in 41 cases. Flow cytometric phenotyping was not successful in any of the cases. The smears were polymorphous in all 15 cases of ALCL and in 1 case of HL (2%). The percentage of abnormal cells ranged from 10% to 90% in cases of ALCL (median, 30%) whereas it ranged from 1% to 25% in HL (median 3%; P = .0003). Three cases of HL showed abnormal cells constituting > or = 20% of the smears. They were all grade 2 disease. Multilobated cells were identified in 14 of the 15 cases of ALCL (93%) and in 3 of the 48 cases of HL (6.25%; P = .0008). CONCLUSION: Our findings indicate that the differentiation of ALCL from HL can be achieved in FNA smears through identification of abnormal cells representing > 30% of the population, a spectrum of abnormal cells and the presence of multilobated nuclei. Rare cases of grade 2 HL may be difficult to differentiate from ALCL.     

Detection of anaplastic lymphoma kinase (ALK) gene rearrangement in non-small cell lung cancer and related issues in ALK inhibitor therapy: a literature review

Anaplastic lymphoma kinase (ALK) encodes a receptor tyrosine kinase, and ALK gene rearrangement (ALK+) is implicated in the oncogenesis of non-small cell lung carcinomas (NSCLCs), especially adenocarcinomas. The ALK inhibitor crizotinib was approved in August 2011 by the US Food and Drug Administration (FDA) for treating late-stage NSCLCs that are ALK+, with a companion fluorescent in situ hybridization (FISH) test using the Vysis ALK Break Apart FISH Probe Kit. This review covers pertinent issues in ALK testing, including approaches to select target patients for the test, pros and cons of different detection methods, and mechanisms as well as monitoring of acquired crizotinib resistance in ALK+ NSCLCs.     

Study of the cytolethal distending toxin-induced cell cycle arrest in HeLa cells: involvement of the CDC25 phosphatase

HeLa cells exposed to Escherichia coli cytolethal distending toxins (CDT) arrest their cell cycle at the G2/M transition. We have shown previously that in these cells the CDK1/cyclin B complex is inactive and can be reactivated in vitro using recombinant CDC25 phosphatase. Here we have investigated in vivo the effects of CDC25 on this cell cycle checkpoint. We report that overexpression of CDC25B or CDC25C overrides an established CDT-induced G2 cell cycle arrest and leads the cells to accumulate in an abnormal mitotic stage with condensed chromatin and high CDK1 activity. This effect can be counteracted by coexpression of the WEE1 kinase. In contrast, overexpression of CDC25B or C prior to CDT treatment prevents G2 arrest and allows most of the cells to progress through mitosis with only a low percentage of cells arrested in abnormal mitosis. The implications of these results on the biochemical nature of the CDT-induced cell cycle arrest are discussed.     

Regulation of the stability and activity of CDC25A and CDC25B by protein phosphatase PP2A and 14-3-3 binding

Cyclin-dependent kinase (CDK)-activating phosphatases, CDC25A and CDC25B, are labile proteins, and their levels vary in a cell cycle-dependent manner. Immediate-early response IER5 protein negatively regulates the cellular CDC25B levels, and stress-induced IER5 expression potentiates G2/M arrest. IER5 binds to protein phosphatase PP2A and regulates the PP2A substrate specificity. We show that IER5 binds to CDC25B and assists PP2A to convert CDC25B to hypophosphorylated forms. Hypophosphorylation at Ser323 results in the dissociation of CDC25B from 14‐3-3 phospho-binding proteins. In IER5 expressing cells, CDC25B dissociated from 14‐3-3 is unstable but slightly activated, because 14‐3-3 inhibits CDC25B polyubiquitination and CDC25B binding to CDK1. The 14‐3-3 binding to CDC25A also impedes CDC25A degradation and CDC25A-CDK2 interaction. We propose that 14‐3-3 is an important regulator of CDC25A and CDC25B and that PP2A/IER5 controls the stability and activity of CDC25B through regulating the interaction of CDC25B and 14‐3-3.     

Ability of human CDC25B phosphatase splice variants to replace the function of the fission yeast Cdc25 cell cycle regulator

CDC25 phosphatases are essential and evolutionary-conserved actors of the eukaryotic cell cycle control. To examine and compare the properties of three splicing variants of human CDC25B, recombinant fission yeast strains expressing the human proteins in place of the endogenous Cdc25 were generated and characterized. We report, that the three CDC25B variants: (i) efficiently replace the yeast counterpart in vegetative growth, (ii) partly restore the gamma and UV radiation DNA damage-activated checkpoint, (iii) fail to restore the DNA replication checkpoint activated by hydroxyurea. Although these yeast strains do not reveal the specific functions of the human CDC25B variants, they should provide useful screening tools for the identification of new cell cycle regulators and pharmacological inhibitors of CDC25 phosphatase.     

Proteome-wide changes induced by the Hsp90 inhibitor, geldanamycin in anaplastic large cell lymphoma cells

The molecular chaperone heat shock protein 90 (Hsp90) affects the function of many oncogenic signaling proteins including nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) expressed in anaplastic large cell lymphoma (ALCL). While ALK-positive ALCL cells are sensitive to the Hsp90 inhibitor and the geldanamycin (GA) analog, 17-allylamino-17-demethoxygeldanamycin (17-AAG), the proteomic effects of these drugs on ALK-positive ALCL cells are unpublished. In this study, we investigated the cellular, biologic, and proteomic changes occurring in ALK-positive ALCL cells in response to GA treatment. GA induced G2/M cell cycle arrest and caspase-3-mediated apoptosis. Furthermore, quantitative proteomic changes analyzed by cleavable isotope-coded affinity tag-LC-MS/MS (cICAT-LC-MS/MS) identified 176 differentially expressed proteins. Out of these, 49 were upregulated 1.5-fold or greater and 70 were downregulated 1.5-fold or greater in GA-treated cells. Analysis of biological functions of differentially expressed proteins revealed diverse changes, including induction of proteins involved in the 26S proteasome as well as downregulation of proteins involved in signal transduction and protein and nucleic acid metabolism. Pathway analysis revealed changes in MAPK, WNT, NF-kappaB, TGFbeta, PPAR, and integrin signaling components. Our studies reveal some of the molecular and proteomic consequences of Hsp90 inhibition in ALK-positive ALCL cells and provide novel insights into the mechanisms of its diverse cellular effects.     

The discovery and development of brentuximab vedotin for use in relapsed Hodgkin lymphoma and systemic anaplastic large cell lymphoma

Progress has been made recently in developing antibody-drug conjugates (ADCs) that can selectively deliver cancer drugs to tumor cells. In principle, the idea is simple: by attaching drugs to tumor-seeking antibodies, target cells will be killed and nontarget cells will be spared. In practice, many parameters needed to be addressed to develop safe and effective ADCs, including the expression profiles of tumor versus normal tissues, the potency of the drug, the linker attaching the drug and placement of the drug on the antibody, and the pharmacokinetic and stability profiles of the resulting ADC. All these issues had been taken into account in developing brentuximab vedotin (Adcetris), an ADC that recently received accelerated approval by the US Food and Drug Administration for the treatment of relapsed Hodgkin lymphoma and systemic anaplastic large cell lymphoma (ALCL). Research is under way to extend the applications of brentuximab vedotin and to advance the field by developing other ADCs with new linker and conjugation strategies.     

Alternative splicing in the regulatory region of the human phosphatases CDC25A and CDC25C

CDC25 phosphatases play key roles in cell proliferation by activating cell cycle-specific cyclin-dependent kinases (CDKs). We identified four new splice variants in the amino-terminal regulatory region of human cdc25C and one in cdc25A. All variants except one retain an intact catalytic domain. Alternative splicing results in loss of phosphorylation sites for kinases like CDK and the calcium/calmodulin-dependent kinase II (CaMKII), which influence CDC25 activity and compartmental localization. In NT2 teratocarcinoma cells, induced for nerve cell differentiation, the smaller sized variant of cdc25C was upregulated. At the protein level both phosphorylation state and isoform distribution differed between cell lines and cell cycle phases.     

The Pan-Immune-Inflammation Value predicts the survival of patients with anaplastic lymphoma kinase-positive non-small cell lung cancer treated with first-line ALK inhibitor

BackgroundAnaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have significantly improved the clinical outcomes of patients with ALK-positive non-small cell lung cancer (NSCLC). However, reliable biomarkers to predict the prognostic role of this treatment are lacking. The Pan-Immune-Inflammation Value (PIV) has recently been demonstrated as a novel comprehensive biomarker to predict survival of patients with solid tumors. Our study aimed to evaluate the prognostic power of PIV in this group of patients.Patients and methods94 patients with advanced ALK-positive NSCLC who received first-line ALK inhibitors were enrolled in this study. PIV was calculated as the product of peripheral blood neutrophil, monocyte, and platelet counts divided by lymphocyte count. Kaplan-Meier method and Cox hazard regression models were used for survival analyses.ResultsThe 1-year progression-free survival (PFS) was 63.5%, and the 5-year overall survival (OS) rate was 55.1%. Patients with higher PIV, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune inflammation index (SII) had worse PFS in univariate analysis, but only the PIV (hazard ratio [HR] = 2.90, 95% confidence interval [CI]: 1.79–4.70, p < 0.001) was an independent prognostic factor in multivariate analysis. Similarly, patients with higher PIV, NLR, PLR, and SII had a worse OS in the univariate analysis, but only the PIV (HR = 4.70, 95% CI: 2.00–11.02, p < 0.001) was significantly associated with worse OS in multivariate analysis.ConclusionPIV is a comprehensive and convenient predictor of both PFS and OS in patients with ALK-positive advanced NSCLC who received first-line ALK TKIs. Prospective clinical trials are required to validate the value of this new parameter.