Chronic lymphocytic leukemia: diagnosis and treatment

Leukemia cancer cells and immune cells derived-exosomes: Possible roles in leukemia progression and therapy

Exosomes have a significant impact on tumor survival, proliferation, metastasis, and recurrence. They also open up new therapeutic options and aid in the pathological identification and diagnosis of cancers. Exosomes have been shown in numerous studies to be essential for facilitating cell-to-cell communication. In B-cell hematological malignancies, the proteins and RNAs that are encased by circulating exosomes are thought to represent prospective sources for therapeutic drugs as well as biomarkers for diagnosis and prognosis. Additionally, exosomes can offer a "snapshot" of the tumor and the metastatic environment at any given point in time. In this review study, we concluded that leukemia-derived exosomes could be utilized as prognostic, diagnostic, and therapeutic biomarkers for individuals suffering from leukemia. Moreover, clinical studies have demonstrated that immune cells like dendritic cells create exosomes, which have the ability to activate the immune system against leukemia.

Unexpected hematologic malignancies after prostatectomy: Case report and literature review

INTRODUCTION

Voiding symptoms, storage symptoms and post-voiding symptoms together constitute lower urinary tract symptoms (LUTS). Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. The most common finding is lymphadenomegaly. Although infrequent, extranodal sites of involvement such as prostate can be detected. Mantle cell lymphoma (MCL) is a subtype of B cell non-Hodgkin lymphomas. Extranodal involvement findings such as prostate may be observed. In this case report, we will present a case in which we performed an open suprapubic prostatectomy (Freyer's) and had CLL as a result of pathology, and a case whose pathology was MCL after transurethral resection of the prostate.

CASE 1

A 60-year-old male patient with LUTS for 6 years. Open suprapubic prostatectomy (Freyer's) was performed on the patient. The pathology result of the prostatectomy material was compatible with CLL involvement.

CASE 2

A 62-year-old male patient with LUTS for 4 years. Transurethral resection of the prostate (TUR-P) was performed on the patient. The pathology result of the prostate was compatible with MCL involvement.

DISCUSSION AND CONCLUSION

There are limited number of cases have been reported about CLL pathology after prostatectomy due to benign prostatic obstruction (BPO). There is no study indicating how often CLL pathology is seen after open prostatectomy or TUR-P due to BPO. In patients with CLL pathology after RRP, open prostatectomy, TUR-P, the need for additional surgery, the difference in prognosis or the difference between the treatment have not been shown in the studies. It should be kept in mind that patients with leukocytosis, lymphocytosis, cytopenias, and LUTS in their clinical presentation and who have not yet been diagnosed with CLL and other hematological malignancies such as mantle cell lymphoma may also have prostate gland involvement and can be diagnosed incidentally by any prostatic intervention.

Anti-Tumour Activity of Glycodendrimer Nanoparticles in a Subcutaneous MEC-1 Xenograft Model of Human Chronic Lymphocytic Leukemia

BACKGROUND

Chronic Lymphocytic Leukaemia (CLL) is an indolent disorder, which mainly affects older adults. Since the advent of chemoimmunotherapy, great progress has been made in its treatment. However, some patients develop a more aggressive form of the disease and are included in the group of high-risk CLL patients with a dismal prognosis and a need for new therapies.

OBJECTIVE

Maltotriose-modified poly(propylene imine) dendrimers were presented as potential agents in targeted therapy for CLL in the murine xenograft model.

METHODS

Tumour, brain and internal organs resected from NOD scid gamma mice were subjected to gross and histopathological evaluation.

RESULTS

The results of ex vivo tissue examination indicated that open-shell glycodendrimers prevented/inhibited the spread of CLL into the brain and internal organs and its transformation into a more aggressive form.

CONCLUSION

The results of the study have a potentially important impact on the design of future personalized therapies as well as clinical trials.

Prognostic Significance of PET/CT in Patients with Chronic Lymphocytic Leukemia (CLL) Treated with Frontline Chemoimmunotherapy

The role of positron emission tomography/computed tomography (PET/CT) in identifying Richter Syndrome (RS) is well established, while its impact on the survival of patients with chronic lymphocytic leukemia (CLL) has been less explored. The clinical characteristics and PET/CT data of 40 patients with a biopsy-proven CLL who required frontline chemoimmunotherapy, FCR (fludarabine, cyclophosphamide, rituximab) in 20 patients, BR (bendamustine, rituximab) in 20, were retrospectively analyzed. Standardized uptake volume (SUV_max) values ≥ 5 were observed more frequently in patients with deletion 11q (p = 0.006) and biopsies characterized by a rate of Ki67 positive cells ≥ 30% (p = 0.02). In the multivariate analysis, the presence of large and confluent PCs emerged as the only factor with a negative impact on progression-free survival (PFS), and overall survival (OS). Deletion 11q also revealed a significant and independent effect on PFS. SUV_max values ≥ 5 showed no statistical impact on PFS while in multivariate analysis, they revealed a significant adverse impact on OS (median survival probability not reached vs. 56 months; p = 0.002). Moreover, patients with higher SUV_max values more frequently developed Richter Syndrome (p = 0.015). Our results show that higher SUV_max values identify CLL patients with a pronounced rate of proliferating cells in the lymph-node compartment, inferior survival, and an increased risk of developing RS.

Combined analysis of ZAP-70 and CD38 expression in sudanese patients with B-cell chronic lymphocytic leukemia

OBJECTIVE

To investigate the ZAP-70 and CD38 expressions and their combined expressions in Sudanese B-CLL patients and their relationships with clinical and hematological characteristics as well as the disease staging at presentation.

RESULTS

In the present cross-sectional descriptive study, analysis of ZAP-70 expression showed that 36/110 (32.7%) patients positively expressed ZAP-70 and insignificant higher presentation in intermediate and at advanced stages as well as no correlation was seen with hematological parameters and clinical features compared with negatively ZAP-70, on the other hand, 41/110 (37.3%) were CD38+ and no significant correlation was shown with the stage at presentation, clinical characteristics (except Splenomegaly, P = 0.02) and hematological parameters. However, in combined expressions of both ZAP-70 and CD38 together, 20/110 (18.2%) were concordantly ZAP-70+/CD38+, 53/110 (48.2%) concordantly ZAP-70-/CD38- and 37/110 (33.6%) either ZAP-70+ or CD38+, and these three groups showed insignificant correlation with clinical (except Splenomegaly, P = 0.03) and hematological parameters, and the stage at presentation. Our data showed the combined analysis of these two markers, lead to classify our patients into three subgroups (either concordant positive, negative or discordant expressions) with statistically insignificant correlation with clinical presentation (except Splenomegaly), hematological parameters and stage at presentation of B-CLL patients.

Ofatumumab - a valid treatment option for chronic lymphocytic leukemia patients

Ofatumumab Arzerra^® is a human monoclonal antibody, which induces killing of a panel of tumor B-cell lines and primary tumor cells by the activation of in vitro complement-dependent cytotoxicity and antibody-dependent, cell-mediated cytotoxicity. The humanized anti-CD20 monoclonal antibody has been approved by the US Food and Drug Administration for the treatment of chronic lymphocytic leukemia patients. This article summarizes this antibody's therapeutic effect on chronic lymphocytic leukemia.

Breed Distribution and Clinical Characteristics of B Cell Chronic Lymphocytic Leukemia in Dogs

BACKGROUND

B-cell chronic lymphocytic leukemia (B-CLL) is the most common hematopoietic malignancy in humans in the developed world and the primary risk factor is genetic. Dogs also develop B-CLL, but there is no systematic description of the disease in dogs. Understanding the epidemiology of B-CLL in dogs may help practitioners recognize the disease and position the dog as a model for future genetic studies.

OBJECTIVES

To describe B-CLL presentation in dogs, its clinicopathologic findings, and breed predisposition.

ANIMALS

Four hundred and ninety-one dogs with B-CLL and 5,673 control dogs with suspicion of a lymphoproliferative disorder (LPD).

METHODS

Retrospective cross-sectional study of dogs for which samples were submitted to the Colorado State University Clinical Immunology Laboratory for immunophenotyping between 2010 and 2014. To assess breed predilection, dogs with B-CLL were compared to those with suspicion of other LPDs using logistic regression.

RESULTS

The median age was 11 years with no sex predilection. Half of the dogs presented with peripheral lymphadenopathy or splenomegaly and 26% had anemia. Eleven small-breed dogs had significantly increased odds of B-CLL. In addition, English Bulldogs had an increased risk and a unique presentation: these dogs were diagnosed at a median of 6 years and expressed lower class II MHC and CD25.

CONCLUSIONS

B-cell chronic lymphocytic leukemia is overrepresented in small-breed dogs. Future genetic studies of these breeds may identify genetic risk factors. The unique presentation of English Bulldogs provides evidence of multiple forms of this disease. Additional studies are necessary to determine whether presenting signs are associated with survival.

Attenuating homologous recombination stimulates an AID-induced antileukemic effect

Inhibition of the RAD51 homologous recombination factor prevents the repair of AID-initiated DNA breaks and induces apoptosis preferentially in AID-expressing human CLL.

Activation-induced cytidine deaminase (AID) is critical in normal B cells to initiate somatic hypermutation and immunoglobulin class switch recombination. Accumulating evidence suggests that AID is also prooncogenic, inducing cancer-promoting mutations or chromosome rearrangements. In this context, we find that AID is expressed in >40% of primary human chronic lymphocytic leukemia (CLL) cases, consistent with other reports. Using a combination of human B lymphoid leukemia cells and mouse models, we now show that AID expression can be harnessed for antileukemic effect, after inhibition of the RAD51 homologous recombination (HR) factor with 4,4′-diisothiocyanatostilbene-2-2′-disulfonic acid (DIDS). As a proof of principle, we show that DIDS treatment inhibits repair of AID-initiated DNA breaks, induces apoptosis, and promotes cytotoxicity preferentially in AID-expressing human CLL. This reveals a novel antineoplastic role of AID that can be triggered by inhibition of HR, suggesting a potential new paradigm to treat AID-expressing tumors. Given the growing list of tumor types with aberrant AID expression, this novel therapeutic approach has potential to impact a significant patient population.

ABT-737 resistance in B-cells isolated from chronic lymphocytic leukemia patients and leukemia cell lines is overcome by the pleiotropic kinase inhibitor quercetin through Mcl-1 down-regulation

Chronic lymphocytic leukemia (CLL) is the most frequent form of leukemia in adult population and despite numerous studies, it is considered an incurable disease. Since CLL is characterized by overexpression of pro-survival Bcl-2 family members, treatments with their antagonists, such as ABT-737, represent a promising new therapeutic strategy. ABT-737 is a BH3 mimetic agent which binds Bcl-2, Bcl-XL and Bcl-w with high affinity, while weakly interacts with Mcl-1 and Bfl-1. Previous studies demonstrated that quercetin, a flavonoid naturally present in food and beverages, was able to sensitize B-cells isolated from CLL patients to apoptosis when associated with death ligands or fludarabine, through a mechanism involving Mcl-1 down-regulation. Here, we report that the association between ABT-737 and quercetin synergistically induces apoptosis in B-cells and in five leukemic cell lines (Combination Index <1). Peripheral blood mononuclear cell from healthy donors were not affected by quercetin treatment. The molecular pathways triggered by quercetin have been investigated in HPB-ALL cells, characterized by the highest resistance to both ABT-737 and quercetin when applied as single molecules, but highly sensitivity to the co-treatment. In this cell line, quercetin down-regulated Mcl-1 through the inhibition of PI3K/Akt signaling pathway, leading to Mcl-1 instability. The same mechanism was confirmed in B-cells. These results may open new clinical perspectives based on a translational approach in CLL therapy.

Myc roles in hematopoiesis and leukemia

Hematopoiesis is a process capable of generating millions of cells every second, as distributed in many cell types. The process is regulated by a number of transcription factors that regulate the differentiation along the distinct lineages and dictate the genetic program that defines each mature phenotype. Myc was first discovered as the oncogene of avian leukemogenic retroviruses; it was later found translocated in human lymphoma. From then on, evidence accumulated showing that c-Myc is one of the transcription factors playing a major role in hematopoiesis. The study of genetically modified mice with overexpression or deletion of Myc has shown that c-Myc is required for the correct balance between self-renewal and differentiation of hematopoietic stem cells (HSCs). Enforced Myc expression in mice leads to reduced HSC pools owing to loss of self-renewal activity at the expense of increased proliferation of progenitor cells and differentiation. c-Myc deficiency consistently results in the accumulation of HSCs. Other models with conditional Myc deletion have demonstrated that different lineages of hematopoietic cells differ in their requirement for c-Myc to regulate their proliferation and differentiation. When transgenic mice overexpress c-Myc or N-Myc in mature cells from the lymphoid or myeloid lineages, the result is lymphoma or leukemia. In agreement, enforced expression of c-Myc blocks the differentiation in several leukemia-derived cell lines capable of differentiating in culture. Not surprising, MYC deregulation is recurrently found in many types of human lymphoma and leukemia. Whereas MYC is deregulated by translocation in Burkitt lymphoma and, less frequently, other types of lymphoma, MYC is frequently overexpressed in acute lymphoblastic and myeloid leukemia, through mechanisms unrelated to chromosomal translocation, and is often associated with disease progression.

Optimal management of older patients with chronic lymphocytic leukemia: some facts and principles guiding therapeutic choices

Chronic lymphocytic leukemia (CLL) is a disease of older patients and median age at diagnosis is 72 years. This older group is under-represented in clinical trials, (median age 58-62 years). Here we review background data on incidence, survival, definitions of older age, fitness criteria, frailty and co-morbidities. Issues influencing the choice of therapy in older patients are also addressed and different therapeutic options are highlighted based on recent available data. Fit older patients with less co-morbidities benefit most from the very effective chemoimmunotherapy (FC-R) given for younger patients today, but whether other novel drug combinations or new agents are more suitable for less fit patients is still unsettled. Based on careful evaluation of published data from larger clinical trials and major referral centers we present our concept of therapy as a guide to optimal management for subgroups of older patients with CLL.

Quercetin downregulates Mcl-1 by acting on mRNA stability and protein degradation

Background:

We recently demonstrated that quercetin, a flavonoid naturally present in food and beverages belonging to the large class of phytochemicals, was able to sensitise leukaemic cells isolated from patients with chronic lymphocytic leukaemia (CLL) when associated with recombinant tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) or anti-CD95. We also showed that quercetin potentiated the effect of fludarabine on resistant B cells from CLL patients. Resistance to therapy in CLL depends on the expression and activity of anti-apoptotic proteins of the Bcl-2 family. Among these, myeloid cell leukaemia-1 (Mcl-1) has been associated with apoptotic resistance in CLL. Therefore, we investigate here whether the sensitising activity of this flavonoid, which leads to increased apoptosis in both cell lines and CLL, could be related to Mcl-1 expression and stability.

Results:

B cells isolated from CLL patients showed different levels of Mcl-1 protein expression, resulting, in several cases, in increased sensitivity to fludarabine. Quercetin significantly enhanced the downregulation of Mcl-1 in B cells isolated from selected patients expressing detectable levels of Mcl-1. In U-937 cells, quercetin increased Mcl-1 mRNA instability in the presence of actinomycin D. When cells were treated with MG-132, a proteasome inhibitor, Mcl-1 protein level increased. However, quercetin, in the presence of Z-Vad-FMK, continued to lower Mcl-1 protein expression, indicating its independence from caspase-mediated degradation. In contrast, co-treatment of quercetin and MG-132 did not revert the effect of MG-132 mono-treatment, thus suggesting a possible interference of quercetin in regulating the proteasome-dependent degradation of Mcl-1. Gossypol, a small-molecule inhibitor of Bcl-2 family members, mimics the activity of quercetin by lowering Mcl-1 expression and sensitising U-937 cells to apoptosis induced by recombinant TRAIL and the Fas-ligand.

Conclusion:

This study demonstrates that in U-937 cells, quercetin downregulates Mcl-1 acting directly or indirectly on its mRNA stability and protein degradation, suggesting that the same mechanism may bypass resistance to apoptosis in leukaemic cells isolated from CLL patients and sensitise B cells to apoptosis induced by drugs and death receptor inducers.

STAT-3 activates NF-kappaB in chronic lymphocytic leukemia cells

NF-κB plays a major role in the pathogenesis of B-cell neoplasms. A broad array of mostly extracellular stimuli has been reported to activate NF-κB, to various degrees, in chronic lymphocytic leukemia (CLL) cells. Because CLL cells harbor high levels of unphosphorylated STAT-3 (USTAT-3) and USTAT-3 was reported to activate NF-κB, we sought to determine whether USTAT-3 activates NF-κB in CLL. Using the electrophoretic mobility shift assay (EMSA), we studied peripheral blood low-density cells from 15 patients with CLL and found that CLL cell nuclear extracts from all the samples bound to an NF-κB DNA probe, suggesting that NF-κB is constitutively activated in CLL. Immunoprecipitation studies showed that STAT-3 bound NF-κB p65, and confocal microscopy studies detected USTAT-3/NF-κB complexes in the nuclei of CLL cells, thereby confirming these findings. Furthermore, infection of CLL cells with retroviral STAT-3-short hairpin RNA attenuated the binding of NF-κB to DNA, as assessed by EMSA, and downregulated mRNA levels of NF-κB-regulated genes, as assessed by quantitative PCR. Taken together, our data suggest that USTAT-3 binds to the NF-κB p50/p65 dimers and that the USTAT-3/NF-κB complexes bind to DNA and activate NF-κB-regulated genes in CLL cells.

Autologous hematopoietic stem cell transplantation in chronic lymphocytic leukemia: results of European intergroup randomized trial comparing autografting versus observation

We present results of a phase 3 randomized trial of autografting in chronic lymphocytic leukemia versus observation for responding patients after first- or second-line treatment. The primary objective was to demonstrate that autografting improves the 5-year event-free survival (EFS) from 30% to 50%. There were 223 enrolled patients, 72% men and 28% women, 83% after first and 17% after second-line treatment. Binet stages were progressive A 13%, B 67%, C 20%; at randomization, 59% were in complete remission, and 41% in less than complete remission. Patients were randomized between autografting (n = 112) and observation (n = 111). Median EFS was 24.4 months (range, 16.7-32 months) in the observation group and 51.2 months (39.8-62.5 months) in the autografting group; the 5-year EFS was 24% and 42%, respectively (P < .001). Accordingly, the 5-year relapse incidence was 76% versus 54% (P < .001). Median time to relapse requiring therapy or death was 40 months (25-56 months) in the observation arm and 65 months (59-71 months) after autografting (P = .002). Cox modeling confirmed that autografting significantly improved EFS (hazard ratio 0.44, 95% confidence interval 0.30-0.65; P < .001). At 5 years, the probability of OS was 85.5% and 84.3% for autografting and observation, respectively (P = .77). In chronic lymphocytic leukemia, consolidating autografting reduces the risk of progression by more than 50% but has no effect on overall survival.

Stem cells in clinical practice: applications and warnings

Stem cells are a relevant source of information about cellular differentiation, molecular processes and tissue homeostasis, but also one of the most putative biological tools to treat degenerative diseases. This review focuses on human stem cells clinical and experimental applications. Our aim is to take a correct view of the available stem cell subtypes and their rational use in the medical area, with a specific focus on their therapeutic benefits and side effects. We have reviewed the main clinical trials dividing them basing on their clinical applications, and taking into account the ethical issue associated with the stem cell therapy.

Stat3 activates the receptor tyrosine kinase like orphan receptor-1 gene in chronic lymphocytic leukemia cells

Background

The receptor tyrosine kinase like orphan receptor (ROR)-1 gene is overexpressed in chronic lymphocytic leukemia (CLL). Because Stat3 is constitutively activated in CLL and sequence analysis revealed that the ROR1 promoter harbors γ-interferon activation sequence-like elements typically activated by Stat3, we hypothesized that Stat3 activates ROR1.

Methodology/Principal Findings

Because IL-6 induced Stat3 phosphorylation and upregulated Ror1 protein levels in MM1 cells, we used these cells as a model. We transfected MM1 cells with truncated ROR1 promoter luciferase reporter constructs and found that IL-6 induced luciferase activity of ROR1-195 and upstream constructs. Co-transfection with Stat3 siRNA reduced the IL-6-induced luciferase activity, suggesting that IL-6 induced luciferase activity by activating Stat3. EMSA and the ChIP assay confirmed that Stat3 binds ROR1, and EMSA studies identified two Stat3 binding sites. In CLL cells, EMSA and ChIP studies determined that phosphorylated Stat3 bound to the ROR1 promoter at those two ROR1 promoter sites, and ChIP analysis showed that Stat3 co-immunoprecipitated DNA of STAT3, ROR1, and several Stat3-regulated genes. Finally, like STAT3-siRNA in MM1 cells, STAT3-shRNA downregulated STAT3, ROR1, and STAT3-regulated genes and Stat3 and Ror1 protein levels in CLL cells.

Conclusion/Significance

Our data suggest that constitutively activated Stat3 binds to the ROR1 promoter and activates ROR1 in CLL cells.

Quercetin induced apoptosis in association with death receptors and fludarabine in cells isolated from chronic lymphocytic leukaemia patients

Background:

Quercetin is a flavonoid naturally present in food and beverages belonging to the large class of phytochemicals with potential anti-cancer properties. Here, we investigated the ability of quercetin to sensitise primary cells from chronic lymphocytic leukaemia (CLL) to death receptor (DR) agonists, recombinant TNF-related-apoptosis-inducing ligand (rTRAIL) and anti-CD95, and to fludarabine, a widely used chemotherapeutic drug against CLL.

Methods:

Peripheral white blood cells were isolated from patients and incubated with medium containing 50 ng ml anti-CD95 agonist antibody; 10 ng ml recombinant TRAIL; 10–25 μM quercetin and 3.5–14 μM fludarabine. Neutral Red assay was used to measure cell viability, where as apoptosis was assessed by determining caspase-3 activity, exposure to Annexin V and PARP fragmentation.

Results:

Quercetin significantly enhanced anti-CD95- and rTRAIL-induced cell death as shown by decreased cell viability, increased caspase-3 and -9 activities, and positivity to Annexin V. In addition, association of quercetin with fludarabine increases the apoptotic response in CLL cells of about two-fold compared with quercetin monotreatment.

Conclusion:

This work shows that resistance to DR- and fludarabine-induced cell death in leukaemic cells isolated from CLL patients can be ameliorated or bypassed by the combined treatment with quercetin. Considering the low toxicity of the molecule, our study results are in favour of a potential use of quercetin in adjuvant chemotherapy in combination with other drugs.

STAT3 is constitutively phosphorylated on serine 727 residues, binds DNA, and activates transcription in CLL cells

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western hemisphere, but its pathogenesis is still poorly understood. Constitutive tyrosine phosphorylation (p) of signal transducer and activator of transcription (STAT) 3 occurs in several solid tumors and hematologic malignancies. In CLL, however, STAT3 is constitutively phosphorylated on serine 727, not tyrosine 705, residues. Because the biologic significance of serine pSTAT3 in CLL is not known, we studied peripheral blood cells of 106 patients with CLL and found that, although tyrosine pSTAT3 was inducible, serine pSTAT3 was constitutive in all patients studied, regardless of blood count, disease stage, or treatment status. In addition, we demonstrated that constitutive serine pSTAT3 translocates to the nucleus by the karyopherin-beta nucleocytoplasmic system and binds DNA. Dephosphorylation of inducible tyrosine pSTAT3 did not affect STAT3-DNA binding, suggesting that constitutive serine pSTAT3 binds DNA. Furthermore, infection of CLL cells with lentiviral STAT3-small hairpin RNA reduced the expression of several STAT3-regulated survival and proliferation genes and induced apoptosis, suggesting that constitutive serine pSTAT3 initiates transcription in CLL cells. Taken together, our data suggest that constitutive phosphorylation of STAT3 on serine 727 residues is a hallmark of CLL and that STAT3 be considered a therapeutic target in this disease.

A review of pharmacologic options for previously untreated chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia and has a heterogeneous clinical course. Some patients experience an indolent disease course, which does not require treatment or affect their overall quality of life. Other patients present with symptomatic advanced disease that rapidly progresses and requires therapy. For these patients, chemotherapy is the mainstay of treatment and has undergone significant evolution in the past few decades. From alkylating agents to purine analogs, response rates have greatly improved with new chemotherapy regimens. The development of chemoimmunotherapy regimens has also transformed the treatment of CLL. This article will review front-line treatment options for CLL and discuss the updated National Comprehensive Cancer Network guidelines.

Differential heat shock protein localization in chronic lymphocytic leukemia

Mechanisms behind carcinogenesis and resistance of tumor cells to treatment regimes remain elusive. The major stress proteins Hsp72, Hsp90, and Hsp27 are credible candidates to provide this resistance, as their overexpression in many cancer types is well documented. In addition to being present inside tumor cells, where they confer resistance to apoptosis, Hsp72, in particular, is presented externally, embedded in the cell membrane of cancer cells. This study aimed to investigate the localization of Hsp72, Hsp90, and Hsp27 in leukocytes from patients with CLL and age-matched control subjects. CLL patients were found to express significantly higher levels of iHsp90 (CLL=2463 MFI; control=748 MFI) and iHsp27 (CLL=2190 MFI; control=1031 MFI) in lymphocytes than that expressed by lymphocytes from control subjects. Furthermore, expression of iHsp90 was shown to be related to stage of disease, and expression of iHsp27 correlated with levels of active caspase-3. Patients were found to express very high levels or very low levels of sHsp72 and iHsp72 in CD5(+)/CD19(+) cells, although surface and intracellular datasets did not correlate. Levels of extracellular Hsp72 circulating in the serum were found to correlate with internal levels of Hsp72 and were also found to be significantly lower in patients receiving corticosteroid treatment than in patients not receiving corticosteroid treatment. Finally, analysis of the number of circulating Tregs revealed significantly elevated numbers in CLL patients compared with control subjects.

Adding fresh frozen plasma to rituximab for the treatment of patients with refractory advanced CLL

BACKGROUND

Many patients with chronic lymphocytic leukaemia (CLL) develop progressive, treatment-resistant disease. Rituximab (RTX), a monoclonal antibody targeting CD20 on B lymphocytes and widely used in other indolent B cell neoplasms is less efficacious in CLL, possibly due to associated complement deficiencies.

OBJECTIVE

To examine in open trial whether providing complement by concurrent administration of fresh frozen plasma (FFP) will enhance the effect of RTX in CLL.

SETTING

Outpatient haematology clinics in Israel and Greece.

PATIENTS

Five patients with severe treatment-resistant CLL. All had been previously treated with fludarabine and three also failed treatment with RTX.

INTERVENTION

Two units of FFP followed with RTX 375 mg/m(2) as a single agent, repeated every 1-2 weeks, as needed.

RESULTS

A rapid and dramatic clinical and laboratory response was achieved in all patients. Lymphocyte counts dropped markedly followed by shrinkage of lymph nodes and spleen and improvement of the anaemia and thrombocytopenia. This could be maintained over 8 months (median) with additional cycles if necessary. Treatment was well tolerated in all cases.

CONCLUSION

Adding FFP to RTX may provide a useful therapeutic option in patients with advanced CLL resistant to treatment.

Modulation of the human equilibrative nucleoside transporter1 (hENT1) activity by IL-4 and PMA in B cells from chronic lymphocytic leukemia

Nucleoside transporters (NTs) are essential for the uptake of therapeutic nucleoside analogs, broadly used in cancer treatment. The mechanisms responsible for NT regulation are largely unknown. IL-4 is a pro-survival signal for chronic lymphocytic leukemia (CLL) cells and has been shown to confer resistance to nucleoside analogs. The aim of this study was to investigate whether IL-4 is able to modulate the expression and function of the human equilibrative NT1 (hENT1) in primary cultures of CLL cells and, consequently, to affect cytotoxicity induced by therapeutic nucleosides analogs. We found that treatment with IL-4 (20 ng/ml for 24 h) increased mRNA hENT1 expression in CLL cells without affecting that of normal B cells. Given that the enhanced mRNA levels of hENT1 in CLL cells did not result in increased transport activity, we examined the possibility that hENT1 induced by IL-4 may require post-translational modifications to become active. We found that the acute stimulation of PKC in IL-4-treated CLL cells by short-term incubation with PMA significantly increased hENT1 transport activity and favoured fludarabine-induced apoptosis. By contrast, and in line with previous reports, IL-4 plus PMA protected CLL cells from a variety of cytotoxic agents. Our findings indicate that the combined treatment with IL-4 and PMA enhances hENT1 activity and specifically sensitizes CLL cells to undergo apoptosis induced by fludarabine.

Systematic review of high dose chemotherapy and autologous haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: what is the published evidence?

Despite improved responses, chronic lymphocytic leukaemia (CLL) remains incurable with conventional chemotherapy. Patients with poor-risk factors or who fail conventional chemoimmunotherapy are offered autografts, preferably after achieving remission. This report presents the totality of evidence through a systematic review that assessed the efficacy of autografts in CLL. A search of MEDLINE databases from 1966-2006 and hand-search of references identified 82 prospective-randomized, non-randomized comparisons or single-arm trials, of which only nine met our inclusion criteria: two trials were funded by public/government, one by private foundations, one jointly by private/public, and was unclear in five. No randomized controlled trials comparing autografts versus conventional chemotherapy (or chemoimmunotherapy) were found. Six studies were single-arm and three were non-randomized with a control-arm (autologous versus allogeneic). Overall, 361 patients were enrolled, but only 292 were transplanted. Transplant-related mortality ranged from 0% to 9%. Complete responses ranged from 74% to 100% and molecular responses ranged from 57% to 88%. Overall survival ranged from 68% at 3 years to 58% at 6 years. It is uncertain whether autograft is superior to conventional therapy. The high incidence of myelodysplastic syndrome (9-12%) is particularly concerning in CLL, where median survival is 9 years.

Hematopoietic Cell Transplantation for Chronic Lymphocytic Leukemia: An Evolving Concept

Recent years have brought major strides to our understanding of prognostic pathobiologic factors in patients with chronic lymphocytic leukemia. This has allowed identification of high-risk patients who may benefit from more aggressive therapies, including hematopoietic cell transplantation. High-dose chemotherapy followed by autologous hematopoietic cell transplantation is feasible, and results in encouraging responses, including molecular responses, with low transplant-associated mortality. However, it has failed to show a plateau effect on survival curves. On the other hand, there is convincing evidence that immunologically mediated graft-versus-leukemia effect of donor T cells are responsible for lowering the incidence of relapse and allowing possible "cure" in allograft recipients, albeit at the expense of high treatment-associated mortality using conventional myeloablation. Reducing the intensity of conditioning regimens has translated into lesser toxicity with reasonable preservation of its curative potential. Autologous or allogeneic hematopoietic cell transplantation in high-risk chronic lymphocytic leukemia remain promising and evolving treatment options. Treatment of CLL should consider stratification according to modern prognostic markers.