BACKGROUND: Lung adenocarcinoma (LUAD), largely remains a primary cause of cancer-related death worldwide. The molecular mechanisms in LUAD metastasis have not been completely uncovered.
METHODS: In this study, we identified differentially expressed genes (DEGs), miRNAs (DEMs) and lncRNAs (DELs) underlying metastasis of LUAD from The Cancer Genome Atlas database. Intersection mRNAs were used to perform gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and co-expression network analysis. In addition, survival analyses of intersection mRNAs were conducted. Finally, intersection mRNAs, miRNAs and lncRNAs were subjected to construct miRNA-mRNA-lncRNA network.
RESULTS: A total of 1015 DEGs, 54 DEMs and 22 DELs were identified in LUAD metastasis and non-metastasis samples. GO and KEGG pathway analysis had proven that the functions of intersection mRNAs were closely related with many important processes in cancer pathogenesis. Among the co-expression interactions network, 22 genes in the co-expression network were over the degree 20. These genes imply that they have connections with many other gene nodes. In addition, 14 target genes (ARHGAP11A, ASPM, HELLS, PRC1, TMPO, ARHGAP30, CD52, IL16, IRF8, P2RY13, PRKCB, PTPRC, SASH3 and TRAF3IP3) were found to be associated with survival in patients with LUAD significantly (log-rank P < 0.05). Two lncRNAs (LOC96610 and ADAM6) acting as ceRNAs were identified based on the miRNA-mRNA-lncRNA network.
CONCLUSIONS: Taken together, the results may provide a novel perspective to develop a multiple gene diagnostic tool for LUAD prognosis, which might also provide potential biomarkers or therapeutic targets for LUAD.

Leukemic stem cells (LSCs) are an emerging target of curative anti-leukemia therapy. In acute lymphoblastic leukemia (ALL), LSCs frequently express CD34 and often lack CD38. However, little is known about markers and targets expressed in ALL LSCs. We have examined marker- and target expression profiles in CD34

BACKGROUND: Thymic epithelial tumours are rare cancers for which new treatment options are required. Identification of putative predictive markers is important for developing clinical trials. We studied the expression of five putative predictive biomarkers, potentially actionable by approved experimental drugs.
METHODS: CD52, CD22, CD26, EG5, and IGF-1R expression were investigated by immunohistochemistry in formalin-fixed surgical samples of thymic epithelial tumour patients. All samples containing 10% positive epithelial tumour cells, independent of tumour cell intensity, were considered as positive. Correlation with histological subtype was performed.
RESULTS: 106 surgical samples (89 thymomas, 12 thymic carcinoma, and 5 thymic neuroendocrine tumours) were evaluated. Overall, CD52, CD22, CD26, EG5 and IGF-1R expression was observed in 7%, 42%, 25%, 42% and 77% of samples, respectively. CD52 expression was more frequent in B2 and B3 thymoma. All TET subtypes stained for CD22, mainly AB thymoma (68%). CD26 expression also correlated with AB thymoma (68%), and A thymoma (50%) subtype, while IGFR1 was the most common marker expressed by thymic carcinoma samples (92%), followed by EG5 (60%). Only EG5 expression was significantly higher in thymic carcinomas than in thymomas (75% vs. 38%, p=0.026).
CONCLUSIONS: Our data were consistent with a previous study of IGF-1R expression. Based on their expression, activity of agents targeting CD52, CD 22, CD26 and EG5 could be further explored in TET patients.

T-prolymphocytic leukemia (T-PLL) is a rare mature T-cell neoplasm characterized by proliferation of prolymphocytes. Most cases involve the T-cell leukemia-1 (TCL1) gene at 14q11.2 resulting in overexpression of TCL-1, which is helpful for distinguishing T-PLL from other T-cell neoplasms. We report a patient with T-PLL whose leukemic cells were positive for TCL-1 by immunohistochemistry but with a normal karyotype. The patient had anti-CD52 antibody therapy for 12 weeks. In a follow-up bone marrow biopsy specimen, numerous TCL-1-positive cells were present, which raised the differential diagnosis of residual T-PLL. However, further immunophenotypic studies confirmed that these cells were hematogones. Therefore a diagnosis of recovering bone marrow was established. The patient underwent stem cell transplant and is now in complete remission. This case demonstrates that hematogones can express TCL-1, and this knowledge is very important for the differential diagnosis in the follow-up marrow of T-PLL patients.

Autologous T cells engineered to express chimeric antigen receptor against the B cell antigen CD19 (CAR19) are achieving marked leukemic remissions in early-phase trials but can be difficult to manufacture, especially in infants or heavily treated patients. We generated universal CAR19 (UCART19) T cells by lentiviral transduction of non-human leukocyte antigen-matched donor cells and simultaneous transcription activator-like effector nuclease (TALEN)-mediated gene editing of T cell receptor α chain and CD52 gene loci. Two infants with relapsed refractory CD19

Adoptive immunotherapy using autologous T cells endowed with chimeric antigen receptors (CAR) has emerged as a powerful means of treating cancer. However, a limitation of this approach is that autologous CAR T cells must be generated on a custom-made basis. Here we show that electroporation of transcription activator-like effector nuclease (TALEN) mRNA allows highly efficient multiplex gene editing in primary human T cells. We use this TALEN-mediated editing approach to develop a process for the large-scale manufacturing of T cells deficient in expression of both their αβ T-cell receptor (TCR) and CD52, a protein targeted by alemtuzumab, a chemotherapeutic agent. Functionally, T cells manufactured with this process do not mediate graft-versus-host reactions and are rendered resistant to destruction by alemtuzumab. These characteristics enable the administration of alemtuzumab concurrently or prior to engineered T cells, supporting their engraftment. Furthermore, endowing the TALEN-engineered cells with a CD19 CAR led to efficient destruction of CD19(+) tumor targets even in the presence of the chemotherapeutic agent. These results demonstrate the applicability of TALEN-mediated genome editing to a scalable process, which enables the manufacturing of third-party CAR T-cell immunotherapies against arbitrary targets. As such, CAR T-cell immunotherapies can therefore be used in an "off-the-shelf" manner akin to other biologic immunopharmaceuticals

T cell prolymphocytic leukemia (T-PLL) is a rare, mature T cell neoplasm with distinct features and an aggressive clinical course. Early relapse and short overall survival are commonplace. Use of the monoclonal anti-CD52 antibody alemtuzumab has improved the rate of complete remission and duration of response to more than 50% and between 6 and 12 months, respectively. Despite this advance, without an allogeneic transplant, resistant relapse is inevitable. We report seven complete and one partial remission in eight patients receiving alemtuzumab and cladribine with or without a histone deacetylase inhibitor. These data show that administration of epigenetic agents can overcome alemtuzumab resistance. We also report epigenetically induced expression of the surface receptor protein CD30 in T-PLL. Subsequent treatment with the anti-CD30 antibody-drug conjugate brentuximab vedotin overcame organ-specific (skin) resistance to alemtuzumab. Our findings demonstrate activity of combination epigenetic and immunotherapy in the incurable illness T-PLL, particularly in the setting of previous alemtuzumab therapy.

The presence of chronic lymphocytic leukaemia (CLL) cells in the thyroid gland is most likely due to a secondary involvement by a systemic disease. The reported incidence of CLL involving the thyroid is extremely low, representing about 3-4% of all thyroid lymphoproliferative neoplasm. We report a rare case of CLL presenting initially in the thyroid gland. Systemic disease was detected as a result of thyroid investigation. An 85 years old woman, with multinodular goiter without adenophaties, was referred to our department, carrying a fine needle aspiration biopsy (FNAB) report of a private institution referring "lymphoid monomorphic proliferation" and suggesting a "Core-needle biopsy" for further investigation. She was euthyroid (TSH-0.5 uU/mL (0.4-4.0), thyroid antibodies negative, including TRab). The patient denied systemic symptoms and at physical examination there were no adenophaties or organomegalies. FNAB analysis was repeated. Although the patient denied constitutional symptoms and there were no relevant findings in physical examination, technetium 99m thyroid gamagraphy (GG) and blood count were additionally asked. FNAB analysis concluded lymphocytic tiroiditis, but thyroid GG revelled global hypocaptation and blood count showed 173.4 x 109 leukocyte/L with 94% lymphocyte. An ecoguided FNAB with flow cytometry identified thyroid infiltration by monotonous population of blasts with phenotype consistent with CLL/malignancy of mature B-cells. CLL/malignancy of mature B-cells was also detected in peripheral blood analysis, suggesting systemic disease with secondary thyroid involvement. The patient started chemotherapy with rituximab and chlorambucil with good response. Pos-treatment GG revelled "Increased levels of uptake in the middle third of the right lower lobe, with low uptake of the remaining parenchyma". In conclusion, good communication with the pathologist can improve diagnostic accuracy and dictate appropriate therapy. The use of techniques such as flow cytometry, immunoglobulin gene rearrangements, and immunohistochemistry has improved diagnostic accuracy and obviated more invasive procedures, such as core needle or open surgery biopsy. Apart from chemotherapy, immunochemotherapy with anti-CD20 and anti-CD52 monoclonal antibodies can be used in the treatment of CLL.

Alemtuzumab is a humanized mouse antibody targeting the CD52 cell surface, which has been effective in patients with advanced stage mycosis fungoides (MF) including erythrodermic MF and Sézary syndrome. There are a few descriptions of large cell transformation after its administration. A young patient with an acute onset of Sézary syndrome treated initially unsuccessfully with fludarabine and cyclophosphamide and later on successfully with alemtuzumab has been described. Three weeks after the beginning of therapy, however, she developed transformed T-cell lymphoma indistinguishable from CD30 anaplastic large-cell lymphoma. After bone marrow transplantation, the transformed CD30 cutaneous T-cell lymphoma recurred as a transformed CD30 plaque MF. All 3 types of lesions showed the same T-cell receptor clonal gene rearrangement, which supports the notion that Sézary syndrome, CD30 anaplastic large-cell lymphoma, and MF are interrelated.

Targeted therapies represent a major breakthrough in the treatment of adult acute lymphoblastic leukaemia (ALL). Because lymphoblastic leukaemia cells express a variety of specific antigens, those ones can serve as targets for monoclonal antibodies (MoAbs). Anti-CD20 (rituximab), anti-CD19 (blinatumomab, SAR3419), anti-CD22 (epratuzumab, inotuzumab ozogamicin) and anti-CD52 (alemtuzumab) have therefore been developed. Possible strategies even include recruitment of CD3 cytotoxic T cells (blinatumomab) or adoptive T-cell therapy by gene transfer of CD19-chimeric antigen receptors (CD19-CARs). Recent data show that antibody-based therapy is a highly promising treatment approach. However, optimal treatment approach still needs to be defined.

Little is known about aberrant antigen expression patterns and their association with cytogenetic aberrations in multiple myeloma (MM). We examined the correlation between flow cytometry and florescence in situ hybridization (FISH) in 167 marrow specimens with MM. Gene expression profiling of CD56, CD117, CD52 and CD20 mRNA in plasma cells (PCs) from patients treated on Total Therapy 2 and Total Therapy 3 trials were also evaluated. Higher expression of CD56 and CD117 was associated with hyperdiploidy. High CD52 mRNA expression was associated with c-MAF and FGFR3 subgroups. Higher expression of CD56 mRNA, but lower Kit expression, were noted in association with FGFR3. In contrast, the c-MAF subgroup showed high Kit expression but lacked NCAM mRNA expression. CKS1B amplification showed positive correlation with CD52 (p=0.0065) but negative correlation with CD20 (p=0.0207). These findings indicate that phenotypic differences in MM are associated with distinct genetic subgroups, which potentially has important diagnostic and prognostic value.

PURPOSE: The CD52-targeted antibody alemtuzumab induces major clinical responses in a group of patients with myelodysplastic syndromes (MDS). The mechanism underlying this drug effect remains unknown.
EXPERIMENTAL DESIGN: We asked whether neoplastic stem cells (NSC) in patients with MDS (n = 29) or acute myelogenous leukemia (AML; n = 62) express CD52.
RESULTS: As assessed by flow cytometry, CD52 was found to be expressed on NSC-enriched CD34(+)/CD38(-) cells in 8/11 patients with MDS and isolated del(5q). In most other patients with MDS, CD52 was weakly expressed or not detectable on NSC. In AML, CD34(+)/CD38(-) cells displayed CD52 in 23/62 patients, including four with complex karyotype and del(5q) and one with del(5q) and t(1;17;X). In quantitative PCR (qPCR) analyses, purified NSC obtained from del(5q) patients expressed CD52 mRNA. We were also able to show that CD52 mRNA levels correlate with EVI1 expression and that NRAS induces the expression of CD52 in AML cells. The CD52-targeting drug alemtuzumab, was found to induce complement-dependent lysis of CD34(+)/CD38(-)/CD52(+) NSC, but did not induce lysis in CD52(-) NSC. Alemtuzumab also suppressed engraftment of CD52(+) NSC in NSG mice. Finally, CD52 expression on NSC was found to correlate with a poor survival in patients with MDS and AML.
CONCLUSIONS: The cell surface target Campath-1 (CD52) is expressed on NSC in a group of patients with MDS and AML. CD52 is a novel prognostic NSC marker and a potential NSC target in a subset of patients with MDS and AML, which may have clinical implications and may explain clinical effects produced by alemtuzumab in these patients.

Advanced systemic mastocytosis (SM) is an aggressive hematopoietic neoplasm with poor prognosis and short survival times. So far, no curative therapy is available for affected patients. We have identified the cell surface antigen CD52 (CAMPATH-1) as a molecular target expressed abundantly on the surface of primary neoplastic mast cells (MCs) in patients with advanced SM. In contrast, neoplastic MCs of patients with indolent SM and normal MCs expressed only low levels or did not express CD52. To study the mechanisms of CD52 expression and the value of this antigen as a potential therapeutic target, we generated a human MC cell line, designated MCPV-1, by lentiviral immortalization of cord blood-derived MC progenitor cells. Functional studies revealed that activated RAS profoundly promotes surface expression of CD52. The CD52-targeting antibody alemtuzumab induced cell death in CD52(+) primary neoplastic MCs obtained from patients with SM as well as in MCPV-1 cells. NSG mice xenotransplanted with MCPV-1 cells survived significantly longer after treatment with alemtuzumab (median survival: 31 d untreated vs. 46 d treated; P=0.0012). We conclude that CD52 is a novel marker and potential therapeutic target in neoplastic MCs in patients with advanced SM.

The randomized Haemato Oncology Foundation for Adults in The Netherlands 68 phase 3 trial compared front-line chemotherapy with chemotherapy plus the CD52 monoclonal antibody alemtuzumab for high-risk chronic lymphocytic leukemia, defined as at least 1 of the following: unmutated immunoglobulin heavy chain genes, deletion 17p or 11q, or trisomy 12. Fit patients were randomized to receive either 6 28-day cycles of oral FC chemotherapy (days 1 through 3: fludarabine 40 mg/m(2) per day and cyclophosphamide 250 mg/m(2) per day: n = 139) or FC plus subcutaneous alemtuzumab 30 mg day 1 (FCA, n = 133). FCA prolonged the primary end point, progression-free survival (3-year progression-free survival 53 vs 37%, P = .01), but not the secondary end point, overall survival (OS). However, a post hoc analysis showed that FCA increased OS in patients younger than 65 years (3-year OS 85% vs 76%, P = .035). FCA also increased the overall response rate (88 vs 78%, P = .036), and the bone marrow minimal residual disease-negative complete remission rate (64% vs 43%, P = .016). Opportunistic infections were more frequent following FCA, but without an increase in treatment related mortality (FCA: 3.8%, FC: 4.3%). FCA improves progression-free survival in high-risk chronic lymphocytic leukemia. As anticipated, FCA is more immunosuppressive than FC, but with due vigilance, does not lead to a higher treatment-related mortality. This study was registered at www.trialregister.nl as trial no. NTR529.

Chronic lymphocytic leukemia (CLL) is clinically heterogeneous. While some patients have indolent disease for many years, 20-30% will progress and ultimately die of their disease. CLL may be classified by the Rai or Binet staging system, mutational status of the immunoglobulin variable heavy-chain gene (IGVH), ZAP-70 overexpression, cytogenetic abnormalities (13q-, + 12, 11q-, 17p-) and expression of several cell surface antigens (CD38, CD49d) that correlate with risk of disease progression. However, none of these markers identify all cases of CLL at risk. In a recent review, we summarized those CD antigens known to correlate with the prognosis of CLL. The present study has identified surface profiles of CD antigens that distinguish clinically progressive CLL from slow-progressive and stable CLL. Using an extended DotScan(™) CLL antibody microarray (Version 3; 182 CD antibodies), and with refined analysis of purified CD19 + B-cells, the following 27 CD antigens were differentially abundant for progressive CLL: CD11a, CD11b, CD11c, CD18, CD19, CD20 (two epitopes), CD21, CD22, CD23, CD24, CD25, CD38, CD40, CD43, CD45, CD45RA, CD52, CD69, CD81, CD84, CD98, CD102, CD148, CD180, CD196 and CD270. The extensive surface profiles obtained provide disease signatures with an accuracy of 79.2%, a sensitivity of 83.9% and a specificity of 72.5% that could provide the basis for a rapid test to triage patients with CLL according to probability of clinical progression and potential earlier requirement for treatment.

Bortezomib has been known as the most promising anti-cancer drug for multiple myeloma (MM). However, recent studies reported that not all MM patients respond to bortezomib. To overcome such a stumbling-block, studies are needed to clarify the mechanisms of bortezomib resistance. In this study, we established a bortezomib-resistant cell line (U266/velR), and explored its biological characteristics. The U266/velR showed reduced sensitivity to bortezomib, and also showed crossresistance to the chemically unrelated drug thalidomide. U266/velR cells had a higher proportion of CD138 negative subpopulation, known as stem-like feature, compared to parental U266 cells. U266/velR showed relatively less inhibitory effect of prosurvival NF-κB signaling by bortezomib. Further analysis of RNA microarray identified genes related to ubiquitination that were differentially regulated in U266/velR. Moreover, the expression level of CD52 in U266 cells was associated with bortezomib response. Our findings provide the basis for developing therapeutic strategies in bortezomib-resistant relapsed and refractory MM patients.

The outlook for adults with refractory and relapsed acute lymphocytic leukemia (ALL) is poor. CD52 is expressed in most patients with ALL. Alemtuzumab is an anti-CD52 humanized monoclonal antibody. This phase II study assessed the efficacy of alemtuzumab combined with granulocyte-colony stimulating factor (G-CSF) to boost antibody-dependent cell cytotoxicity mediated by neutrophils. Twelve patients with relapsed (n = 11) or refractory (n = 1) ALL, including four relapses postallogeneic stem cell transplantation, were treated and monitored between October 2006 and January 2011. Patients received 1 wk of alemtuzumab every other day at increasing doses of 3, 10, and 30 mg to test tolerance and 30 mg three times a week for 12-18 infusions. If in complete remission (CR), patients received maintenance therapy for 1 wk, every 2 months. G-CSF was administered at 5 μg/kg per day during alemtuzumab administration. The primary endpoint was disappearance of blast cells on a marrow aspirate. CD52 was expressed in all patients. Four patients reached CR. In one additional patient, clearance of blast cells was observed in peripheral blood but not in the marrow. The most frequent adverse events during course 1 of treatment were fever and chills (n = 3), skin rash (n = 3), and bronchospasm (n = 2). Tumor lysis syndrome was observed at treatment initiation in one patient who reached CR. All patients progressed within a few months and all but one died. The surviving patient is still alive after relapse and a second allogeneic stem cell transplantation. This study shows that in relapse/refractory ALL, alemtuzumab with G-CSF can produce good responses of short duration.

Peripheral T-cell lymphoma, not otherwise specified is a heterogeneous group of aggressive neoplasms with indistinct borders. By gene expression profiling we previously reported unsupervised clusters of peripheral T-cell lymphomas, not otherwise specified correlating with CD30 expression. In this work we extended the analysis of peripheral T-cell lymphoma molecular profiles to prototypical CD30(+) peripheral T-cell lymphomas (anaplastic large cell lymphomas), and validated mRNA expression profiles at the protein level. Existing transcriptomic datasets from peripheral T-cell lymphomas, not otherwise specified and anaplastic large cell lymphomas were reanalyzed. Twenty-one markers were selected for immunohistochemical validation on 80 peripheral T-cell lymphoma samples (not otherwise specified, CD30(+) and CD30(-); anaplastic large cell lymphomas, ALK(+) and ALK(-)), and differences between subgroups were assessed. Clinical follow-up was recorded. Compared to CD30(-) tumors, CD30(+) peripheral T-cell lymphomas, not otherwise specified were significantly enriched in ALK(-) anaplastic large cell lymphoma-related genes. By immunohistochemistry, CD30(+) peripheral T-cell lymphomas, not otherwise specified differed significantly from CD30(-) samples [down-regulated expression of T-cell receptor-associated proximal tyrosine kinases (Lck, Fyn, Itk) and of proteins involved in T-cell differentiation/activation (CD69, ICOS, CD52, NFATc2); upregulation of JunB and MUM1], while overlapping with anaplastic large cell lymphomas. CD30(-) peripheral T-cell lymphomas, not otherwise specified tended to have an inferior clinical outcome compared to the CD30(+) subgroups. In conclusion, we show molecular and phenotypic features common to CD30(+) peripheral T-cell lymphomas, and significant differences between CD30(-) and CD30(+) peripheral T-cell lymphomas, not otherwise specified, suggesting that CD30 expression might delineate two biologically distinct subgroups.

Adult T-cell leukemia (ATL) is an aggressive malignancy of CD4(+)CD25(+) lymphocytes caused by human T-cell lymphotropic virus type 1. Currently, there is no accepted curative therapy for ATL. In gene expression profiling, the antiapoptotic protein survivin (BIRC5) demonstrated a striking increase in ATL, and its expression was increased in patient ATL cells resistant to the anti-CD52 monoclonal antibody alemtuzumab (Campath-1H). In this study, we investigated the antitumor activity of a small-molecule survivin suppressant YM155 alone and in combination with alemtuzumab in a murine model of human ATL (MET-1). Both YM155 alone and its combination with alemtuzumab demonstrated therapeutic efficacy by lowering serum soluble IL-2Rα (sIL-2Rα) levels (P < .001) and prolonged the survival of tumor-bearing mice (P < .0001). Moreover, the combination of YM155 with alemtuzumab demonstrated markedly additive antitumor activity by significantly lowering serum sIL-2Rα levels and improving the survival of leukemia-bearing mice compared with monotherapy with either YM155 (P < .001) or alemtuzumab (P < .05). More significantly, all mice that received the combination therapy survived and were tumor free >6 months after treatment. Our data support a clinical trial of the combination of YM155 with alemtuzumab in ATL. This trial was registered at www.clinicaltrials.gov as #NCT00061048.

PURPOSE: In chronic lymphocytic leukemia (CLL), TP53 deletion/mutation is strongly associated with an adverse outcome and resistance to chemotherapy-based treatment. In contrast, TP53 defects are not associated with resistance to the anti-CD52 monoclonal antibody alemtuzumab or methylprednisolone. In an attempt to improve the treatment of TP53-defective CLL, a multicenter phase II study was developed to evaluate alemtuzumab and methylprednisolone in combination.
PATIENTS AND METHODS: Thirty-nine patients with TP53-deleted CLL (17 untreated and 22 previously treated) received up to 16 weeks of treatment with alemtuzumab 30 mg three times a week and methylprednisolone 1.0 g/m(2) for five consecutive days every 4 weeks. Antimicrobial prophylaxis consisted of cotrimoxazole, itraconazole, and aciclovir (or valganciclovir for asymptomatic cytomegalovirus viremia). The primary end point was response as assigned by an end-point review committee. Secondary end points were safety, progression-free survival (PFS) and overall survival (OS).
RESULTS: The overall response rate, complete response rate (including with incomplete marrow recovery), median PFS, and median OS were 85%, 36%, 11.8 months, and 23.5 months, respectively, in the entire cohort and 88%, 65%, 18.3 months, and 38.9 months, respectively, in previously untreated patients. Grade 3 to 4 hematologic and glucocorticoid-associated toxicity occurred in 67% and 23% of patients, respectively. Grade 3 to 4 infection occurred in 51% of the overall cohort and in 29% of patients less than 60 years of age. Treatment-related mortality was 5%.
CONCLUSION: Alemtuzumab plus methypredisolone is the most effective induction regimen hitherto reported in TP53-deleted CLL. The risk of infection is age related and, in younger patients, seems only marginally higher than that associated with rituximab, fludarabine, and cyclophosphamide.

Although numerous mouse models of B-cell malignancy have been developed via the enforced expression of defined oncogenic lesions, the feasibility of generating lineage-defined human B-cell malignancies using mice reconstituted with modified human hematopoietic stem cells (HSCs) remains unclear. In fact, whether human cells can be transformed as readily as murine cells by simple oncogene combinations is a subject of considerable debate. Here, we describe the development of humanized mouse model of MYC/BCL2-driven 'double-hit' lymphoma. By engrafting human HSCs transduced with the oncogene combination into immunodeficient mice, we generate a fatal B malignancy with complete penetrance. This humanized-MYC/BCL2-model (hMB) accurately recapitulates the histopathological and clinical aspects of steroid-, chemotherapy- and rituximab-resistant human 'double-hit' lymphomas that involve the MYC and BCL2 loci. Notably, this model can serve as a platform for the evaluation of antibody-based therapeutics. As a proof of principle, we used this model to show that the anti-CD52 antibody alemtuzumab effectively eliminates lymphoma cells from the spleen, liver and peripheral blood, but not from the brain. The hMB humanized mouse model underscores the synergy of MYC and BCL2 in 'double-hit' lymphomas in human patients. Additionally, our findings highlight the utility of humanized mouse models in interrogating therapeutic approaches, particularly human-specific monoclonal antibodies.

Rarer chronic lymphoid leukaemias represent a challenge to the clinicians due to the limited information on their pathogenesis, difficulties on setting up prospective clinical trials and to their refractoriness to drugs used in the most common form of chronic lymphocytic leukaemia (CLL). In this review all these issues are addressed in three B-cell leukaemias: B-cell prolymphocytic leukaemia (B-PLL), hairy cell leukaemia (HCL) and HCL-variant and three T-cell leukaemias: T-cell prolymphocytic leukaemia (T-PLL), T-cell large granular lymphocytic leukaemia (T-cell LGLL) and adult T-cell leukaemia lymphoma (ATLL). Data will be presented on the natural history, current therapies and emerging drugs potentially useful in the treatment of patients with these leukaemias. Emphasis is made on: 1- the novel agents targeting a variety of B and T-cell antigens expressed on the surface of the leukaemic cells; these are either unconjugated monoclonal antibodies (McAb) such as Rituximab (anti-CD20), the second and third generation of anti-CD20 McAbs, Alemtuzumab (anti-CD52), Siplizumab (anti-CD2), Daclizumab (anti-CD25) and KW-0761, an anti-chemokine receptor 4 (CCR4) or McAbs conjugated to toxins such as CD22 linked to the pseudomonas exotoxin or radiolabelled McAb; 2- the use of new purine nucleosides such as nelarabine and 3- agents targeting deregulated genes in the leukaemic cells from these diseases such as the Poly (ADP-ribose) polymerase (PARP) Olarapib in T-PLL with deregulation of the ataxia telangiectasia mutated (ATM) gene. Data of phase I and II clinical studies with these agents as well as the potential and current use of other drugs are outlined.

Peripheral T-cell lymphomas (PTCLs) are heterogeneous and uncommon malignancies characterized by an aggressive clinical course and a mostly poor outcome with current treatment strategies. The recent genome-wide molecular characterization of several entities has provided novel insights into their pathobiology and led to the identification of new biomarkers with diagnostic, prognostic or therapeutic implications for PTCL patients. Cell lineage and differentiation antigens (markers of γδ or NK lineage, of cytotoxicity, of follicular helper T cells) reflect the tumour's biological behaviour, and their detection in tissue samples may refine the diagnostic and prognostic stratification of the patients. Previously unrecognized gene rearrangements are being discovered (ITK-SYK translocation, IRF4/MUM1 and DUSP22 rearrangements), and may serve as diagnostic genetic markers. Deregulated molecules within oncogenic pathways (NF-κB, Syk, PDGFRα) and immunoreactive cell-surface antigens (CD30, CD52) have been brought to the fore as potential targets for guiding the development of novel therapies.

The molecular changes induced by alemtuzumab following binding of CD52 on B tumor cells were investigated. Alemtuzumab alone had no detectable impact on cell signaling but cross-linking of alemtuzumab on the surface of B tumor lines with anti-human Fc antibodies induced a transient Ca(2+) flux followed by phosphorylation of several kinases involved in stress and survival pathways, and expression of associated proteins including TNF-α. Cross-linking of alemtuzumab also induced capping and caspase-dependent apoptosis of the tumor lines. When using primary cells from B-CLL patients, alemtuzumab alone was capable of inducing protein phosphorylation and apoptosis through the cross-linking of alemtuzumab by FcγRIIb receptors on B-CLL cells. Apoptosis was prevented by blocking of FcγRIIb receptors with anti-CD32 antibody. Overall, our results indicate that cross-linking of alemtuzumab on B tumor cells can occur naturally through Fc receptor interaction and leads to the activation of specific cellular pathways and induction of apoptosis.

Ecotropic viral integration site 1 (EVI1) is an oncogenic transcription factor in human acute myeloid leukemia (AML) with chromosomal alterations at 3q26. Because a high expression of EVI1 protein in AML cells predicts resistance to chemotherapy with a poor outcome, we have searched for molecular targets that will treat these patients with AML. In this study, we determined that CD52, which is mainly expressed on lymphocytes, is highly expressed in most cases of AML with a high EVI1 expression (EVI1(High)). CAMPATH-1H, a humanized monoclonal antibody against CD52, has been used to prevent graft-versus-host disease and treat CD52-positive lymphoproliferative disorders. Here, we investigated the antitumor effect of CAMPATH-1H on EVI1(High) AML cells. CAMPATH-1H significantly inhibited cell growth and induced apoptosis in CD52-positive EVI1(High) leukemia cells. Furthermore, CAMPATH-1H induced complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity against CD52-positive EVI1(High) leukemia cells. After an intravenous injection of CAMPATH-1H into NOD/Shi-scid/IL-2Rγ;null mice with subcutaneous engraftment of EVI1(High) leukemia cells, tumor growth rates were significantly reduced, and the mice survived longer than those in the phosphate-buffered saline-injected control group. Thus, CAMPATH-1H is a potential therapeutic antibody for the treatment of patients with EVI1(High) leukemia.

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) does correspond to a heterogeneous group of nodal and extranodal mature T-cell lymphomas, with a low prevalence in Western countries. PTCL-NOS accounts for about 25% of all PTCL, which represent over 15% of all lymphomas. In the lymph node, PTCL-NOS shows paracortical or diffuse infiltrates with effacement of the normal architecture, with a broad cytological spectrum and a frequently observed inflammatory background. Some morphological variants include: lymphoepithelioid or Lennert's type, T-zone, and follicular. PTCL-NOS is characterized by an aberrant T-cell phenotype, with frequent loss of CD5 and CD7. A CD4+/CD8- phenotype predominates in nodal cases. CD4/CD8 +/+ or -/- is at times seen, as is CD8, CD56 and cytotoxic granule expression. Ki-67 rate is typically high. TCR β-chain is usually expressed; TCR genes are most often clonally rearranged. PTCL-NOS typically occurs in adults (median age 55-60 years), with a higher prevalence in males. It presents more often as disseminated disease, occasionally with eosinophilia, pruritis or hemophagocytic syndrome. Patients often have B symptoms, generalized lymphadenopathy, bone marrow infiltration, and extranodal involvement, with high or high-intermediate IPI score in 50-70% of cases. Prognosis is poor, with a 5-year OS of 20-30%. Some variables, like ST2(L), CXCR5, CXCR3, EBV infection, cytotoxic granule expression, high proliferative index, NF-κB expression, were proposed as prognostic indicators, but the IPI score, and its variant called PIT, remains the most effective prognostic factor. Patients with PTCL-NOS should be treated with anthracycline-containing chemotherapy, followed by radiotherapy in cases of stage I-II disease. This strategy is associated with an overall response rate higher than 60%, but the 5-year overall survival is only 20-30%. Upfront high-dose chemotherapy supported by autologous or allogeneic SCT is an investigational approach, with a 4-year overall survival of about 40%. Patients with chemosensitive relapse respond favorably to high-dose chemotherapy and ASCT, with long-term survival rates of 35-45%. Graft-versus-lymphoma effect following allogeneic SCT has been observed; and reduced intensity conditioning emerges as an attractive strategy for frail patients. Most patients with PTCL-NOS are enrolled in prospective trials to explore new approaches, and new agents, like gemcitabine, alemtuzumab and pralatrexate, are being investigated.

We present the results of an open-label clinical trial and the clinical use of alemtuzumab in 19 heavily pretreated patients with advanced erythrodermic cutaneous T-cell lymphomas (CTCL) (erythrodermic mycosis fungoides and Sézary syndrome). Ten patients received alemtuzumab intravenously using an escalating dose regimen with a final dose of 30 mg three times weekly for 4 weeks followed by subcutaneous administration for 8 weeks. Nine patients were treated with only the SQ or IV dosing. The overall response rate was 84%, with 9 (47%) complete and 7 (37%) partial remissions. The median follow-up was 24 months (range, 6 to 62+ months). Median overall survival was 41 months whereas median progression free survival was 6 months. Minimal residual disease by T-cell gene rearrangement studies was detected in 11 patients who achieved complete response and partial response. Toxicities included myelosuppression and infections; however, the majority of side effects were of Grade 2 in severity and transient. One patient was diagnosed with a concurrent lymphoma (mantle cell lymphoma) 6 months after completing alemtuzumab therapy. Alemtuzumab is particularly effective in patients with erythrodermic CTCL with acceptable toxicities. Combined strategies with alemtuzumab may achieve molecular remissions with longer response durations.

BACKGROUND: T-cell large granular lymphocytic leukemia is a clonal proliferation of cytotoxic T-lymphocytes which often results in severe cytopenia. Current treatment options favor chronic immunosuppression. Alemtuzumab, a humanized monoclonal antibody against glycophosphatidylinositol-anchored CD52, is approved for patients refractory to therapy in other lymphoid malignancies.
DESIGN AND METHODS: We retrospectively examined treatment outcomes in 59 patients with CD8+ T-cell large granular lymphocytic leukemia, 41 of whom required therapy. Eight patients with severe refractory cytopenia despite multiple treatment regimens had been treated with subcutaneous alemtuzumab as salvage therapy. Flow cytometry was used to monitor expression of glycophosphatidylinositol-anchored CD52, CD55, and CD59 as well as to characterize T-cell clonal expansions by T-cell receptor variable beta-chain (Vbeta) repertoire.
RESULTS: Analysis of the effects of alemtuzumab revealed remissions with restoration of platelets in one of one patient, red blood cell transfusion independence in three of five patients and improvement of neutropenia in one of three, resulting in an overall response rate of 50% (4/8 patients). Clonal large granular lymphocytes exhibited decreased CD52 expression post-therapy in patients refractory to treatment. Samples of large granular lymphocytes collected prior to therapy also unexpectedly had a significant proportion of CD52-negative cells while a healthy control population had no such CD52 deficiency (p=0.026).
CONCLUSIONS: While alemtuzumab may be highly effective in large granular lymphocytic leukemia, prospective serial monitoring for the presence of CD52-deficient clonal cytotoxic T-lymphocytes should be a component of clinical trials investigating the efficacy of this drug. CD52 deficiency may explain lack of response to alemtuzumab, and such therapy may confer a survival advantage to glycophosphatidylinositol-negative clonal cytotoxic T-lymphocytes.

Treatment results of mantle cell lymphomas (MCL) are not satisfactory and novel therapeutic approaches are warranted. Because "shared" tumor antigens like the group of cancer testis antigens are only rarely expressed in MCL, we applied serological analysis of antigens using recombinant expression cloning (SEREX) to a complementary DNA library derived from five cases of MCL using the sera of eight patients with MCL in order to define MCL-associated antigens that are immunogenic in these patients and might be used as vaccines for patients with MCL. Five antigens were detected by SEREX. Four of the five detected antigens (hypothetical protein FLK10233, recombining binding protein suppressor, a chromosomal sequence, and interleukin-1 receptor associated kinase) are also expressed by a wide spectrum of normal human cells, excluding their use as vaccines. In contrast, the expression of CD52, which was detected by antibodies in the serum of an MCL patient, is restricted to hematopoietic cells. Interestingly, anti-CD52 antibodies were detected in this patient before and >2 years after allogeneic transplantation, indicating that both the autologous as well as the allogeneic immune system recognized CD52. Since the anti-CD52 monoclonal antibody alemtuzumab has shown activity in MCL, a vaccine consisting of recombinant CD52 alone or combined with passive immunotherapy using alemtuzumab warrants furthers clinical and immunological evaluation in MCL.

Graft failure is a significant cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). We used a nonmyeloablative conditioning regimen consisting of the lympho-depleting humanized CD52-antibody Campath-1H and fludarabine to rescue 12 consecutive children age 9 months to 17 years with engraftment failure after initial myeloablative HSCT. Primary diagnoses included lymphohematologic malignancies (n=6), severe combined immunodeficiency syndrome (SCID) (n=4), and metabolic diseases (n=2). The same stem cell donor was used as for the primary graft: mismatched family member (n=7), matched unrelated donor (n=4), or matched related donor (n=1). The patients received doses of CD34+ cells that did not significantly differ from those used in the initial, failed transplant. At a median follow-up of 51 months (range, 4 to 84 months), 6 of 6 patients with nonmalignant diseases and 4 of 6 patients with malignancy were alive. Two patients died, 1 patient from pulmonary toxicity and 1 from relapse, at 51 days and 8 months posttransplantation, respectively. All 12 patients initially achieved sustained neutrophil engraftment and complete donor chimerism by day 28. Six patients received donor lymphocyte infusion (DLI) after "rescue" therapy to maintain donor chimerism. At 6 months, 4 patients had complete donor cell engraftment, 4 had 15% to 89% stable donor chimerism, and 3 had developed secondary graft failure. This conditioning regimen was generally well tolerated; 4 of the 12 patients never became neutropenic, and 9 never became thrombocytopenic. Only 1 patient developed graft-versus-host disease (GVHD; grade 1), and none had chronic GVHD. Thus, the regimen that we describe can be used with minimal toxicity to effectively overcome graft failure after myeloablative HSCT in children.