Venetoclax resistance induced by activated T cells can be counteracted by sphingosine kinase inhibitors in chronic lymphocytic leukemia.

The treatment of chronic lymphocytic leukemia (CLL) patients with venetoclax-based regimens has demonstrated efficacy and a safety profile, but the emergence of resistant cells and disease progression is a current complication. Therapeutic target of sphingosine kinases (SPHK) 1 and 2 has opened new opportunities in the treatment combinations of cancer patients. We previously reported that the dual SPHK1/2 inhibitor, SKI-II enhanced the in vitro cell death triggered by fludarabine, bendamustine or ibrutinib and reduced the activation and proliferation of chronic lymphocytic leukemia (CLL) cells. Since we previously showed that autologous activated T cells from CLL patients favor the activation of CLL cells and the generation of venetoclax resistance due to the upregulation of BCL-XL and MCL-1, we here aim to determine whether SPHK inhibitors affect this process. To this aim we employed the dual SPHK1/2 inhibitor SKI-II and opaganib, a SPHK2 inhibitor that is being studied in clinical trials. We found that SPHK inhibitors reduce the activation of CLL cells and the generation of venetoclax resistance induced by activated T cells mainly due to a reduced upregulation of BCL-XL. We also found that SPHK2 expression was enhanced in CLL cells by activated T cells of the same patient and the presence of venetoclax selects resistant cells with high levels of SPHK2. Of note, SPHK inhibitors were able to re-sensitize already resistant CLL cells to a second venetoclax treatment. Our results highlight the therapeutic potential of SPHK inhibitors in combination with venetoclax as a promising treatment option for the patients.

[Bruton tyrosine kinase inhibitors. What does the oncohematologist and the cardiologist need to know?] / Inhibidores de Bruton tirosina quinasa ¿qué necesita saber el oncohematólogo y el cardiólogo?

Advances in knowledge incorporated in the last decade have modified the treatment paradigm in most of the malignant hematological diseases. In particular, the introduction of Bruton tyrosine kinase inhibitors (BTKi) and other target drugs together with new monoclonal antibodies have become agents of choice for both chronic lymphocytic leukemia (CLL) and other peripheral "B" lymphomas such as mantle cell lymphoma (MCL). The results of efficacy against genotoxic therapy are so successful that the end of chemoimmunotherapy, especially for CLL, is already a postulate recognized by the main research groups. On the other hand, the new drugs modified the profile of adverse events, which forced the development of new subspecialties such as cardio-oncology, which currently constitutes a bastion for the rational management of these patients. This review aims to highlight the current state of knowledge on these pathologies, pharmacological principles together with new adverse events of iBTK and the invaluable contribution of cardiology for correct management of these patients.

Los avances en el conocimiento incorporados en la última década han modificado en gran parte el paradigma del tratamiento de las enfermedades hematológicas malignas. Particularmente la introducción de los inhibidores de la Bruton tirosina quinasa (iBTK) y otras drogas blanco junto a nuevos anticuerpos monoclonales se han transformado en los agentes de elección, tanto para la leucemia linfática crónica (LLC) como para otros linfomas "B" periféricos como el linfoma de células del manto (LCM). Los resultados de eficacia frente a la terapia genotóxica son tan exitosos que el fin de la quimio inmunoterapia, sobre todo para la LLC, es ya un postulado reconocido por los principales grupos de investigación. Por otra parte, los nuevos fármacos modificaron el perfil de eventos adversos lo que obligó al desarrollo de nuevas subespecialidades como la cardiooncología, la cual constituye actualmente un baluarte para el manejo racional de estos pacientes. La presente revisión tiene como objetivo destacar el estado actual del conocimiento sobre estas enfermedades, los principios farmacológicos junto a los nuevos eventos adversos de los iBTK y el invalorable aporte de la cardiología para un correcto tratamiento y control de estos pacientes.

Inhibidores de bruton tirosina quinasa. ¿Qué necesita saber el oncohematólogo y el cardiólogo? / Bruton tyrosine kinase inhibitors. What does the oncohematologist and the cardiologist need to know?

Resumen Los avances en el conocimiento incorporados en la última década han modificado en gran parte el paradigma del tratamiento de las enfermedades hematológicas malignas. Particularmente la intro ducción de los inhibidores de la Bruton tirosina quinasa (iBTK) y otras drogas blanco junto a nuevos anticuerpos monoclonales se han transformado en los agentes de elección, tanto para la leucemia linfática crónica (LLC) como para otros linfomas "B" periféricos como el linfoma de células del manto (LCM). Los resultados de eficacia frente a la terapia genotóxica son tan exitosos que el fin de la quimio inmunoterapia, sobre todo para la LLC, es ya un postulado reconocido por los principales grupos de investigación. Por otra parte, los nuevos fármacos modificaron el perfil de eventos adversos lo que obligó al desarrollo de nuevas subespecialidades como la cardio-oncología, la cual constituye actualmente un baluarte para el manejo racional de estos pacientes. La presente revisión tiene como objetivo destacar el estado actual del conocimiento sobre estas enfermedades, los principios farmacológicos junto a los nuevos eventos adversos de los iBTK y el invalorable aporte de la cardiología para un correcto tratamiento y control de estos pacientes.

Abstract Advances in knowledge incorporated in the last decade have modified the treatment paradigm in most of the malignant hematological diseases. In particular, the introduction of Bruton tyrosine kinase inhibitors (BTKi) and other target drugs together with new monoclonal antibodies have become agents of choice for both chronic lym phocytic leukemia (CLL) and other peripheral "B" lymphomas such as mantle cell lymphoma (MCL). The results of efficacy against genotoxic therapy are so successful that the end of chemoimmunotherapy, especially for CLL, is already a postulate recognized by the main research groups. On the other hand, the new drugs modified the profile of adverse events, which forced the development of new subspecialties such as cardio-oncology, which currently constitutes a bastion for the rational management of these patients. This review aims to highlight the current state of knowledge on these pathologies, pharmacological principles together with new adverse events of iBTK and the invaluable contribution of cardiology for correct management of these patients.

Revisiting the role of interleukin-8 in chronic lymphocytic leukemia.

The proliferation and survival of malignant B cells in chronic lymphocytic leukemia (CLL) depend on signals from the microenvironment in lymphoid tissues. Among a plethora of soluble factors, IL-8 has been considered one of the most relevant to support CLL B cell progression in an autocrine fashion, even though the expression of IL-8 receptors, CXCR1 and CXCR2, on leukemic B cells has not been reported. Here we show that circulating CLL B cells neither express CXCR1 or CXCR2 nor they respond to exogenous IL-8 when cultured in vitro alone or in the presence of monocytes/nurse-like cells. By intracellular staining and ELISA we show that highly purified CLL B cells do not produce IL-8 spontaneously or upon activation through the B cell receptor. By contrast, we found that a minor proportion (<0.5%) of contaminating monocytes in enriched suspensions of leukemic cells might be the actual source of IL-8 due to their strong capacity to release this cytokine. Altogether our results indicate that CLL B cells are not able to secrete or respond to IL-8 and highlight the importance of methodological details in in vitro experiments.

Neutrophils from chronic lymphocytic leukemia patients exhibit an increased capacity to release extracellular traps (NETs).

Chronic lymphocytic leukemia (CLL) is characterized by immune defects that contribute to a high rate of infections and autoimmune cytopenias. Neutrophils are the first line of innate immunity and respond to pathogens through multiple mechanisms, including the release of neutrophil extracellular traps (NETs). These web-like structures composed of DNA, histones, and granular proteins are also produced under sterile conditions and play important roles in thrombosis and autoimmune disorders. Here we show that neutrophils from CLL patients are more prone to release NETs compared to those from age-matched healthy donors (HD). Increased generation of NETs was not due to higher levels of elastase, myeloperoxidase, or reactive oxygen species production. Instead, we found that plasma from CLL patients was able to prime neutrophils from HD to generate higher amounts of NETs upon activation. Plasmatic IL-8 was involved in the priming effect since its depletion reduced plasma capacity to enhance NETs release. Finally, we found that culture with NETs delayed spontaneous apoptosis and increased the expression of activation markers on leukemic B cells. Our study provides new insights into the immune dysregulation in CLL and suggests that the chronic inflammatory environment typical of CLL probably underlies this inappropriate neutrophil priming.

Telomere shortening associated with increased genomic complexity in chronic lymphocytic leukemia.

Telomeric dysfunction has been proposed as an emerging prognostic factor in chronic lymphocytic leukemia (CLL). We have explored the relationship between telomere length (TL) and chromosome alterations studied by fluorescence in situ hybridization (FISH) and conventional cytogenetics in 107 newly diagnosed CLL patients; 61 normal controls were also evaluated. Results were correlated with clinical parameters and outcome. Absolute TL measurement was carried out on DNA samples by real-time quantitative PCR. A significant telomere shortening in patients compared to controls was observed (p = 0.0001). The analysis taking into account FISH risk groups showed shorter TLs in cases with del11q/17p compared to patients with 13q14 deletion as a single alteration (p = 0.0037), no alterations (NA) (p = 0.028), and cases with abnormal karyotypes (p = 0.014). In addition, a significant TL reduction in cases with two or more anomalies with respect to those with NA (p = 0.033) and with one alteration (p = 0.045), and no differences compared to cases with deletions 11q/17p were observed. Patients with only one anomaly did not show statistical differences with respect to controls; meanwhile, a significant TL reduction in cases with two or more aberrations was observed (p = 0.025). The shortest telomeres were associated to 11q/17p deletion with significant differences compared to the remaining groups (p ≤ 0.045). Significantly shorter treatment free survival in patients with two or more alterations compared to those with NA plus one abnormality was observed (p = 0.0006). Our findings support the association between short TL and chromosome alterations in CLL and indicate the importance of telomere dysfunction in driving genomic instability in this pathology.

Surface localization of high-mobility group nucleosome-binding protein 2 on leukemic B cells from patients with chronic lymphocytic leukemia is related to secondary autoimmune hemolytic anemia.

Chronic lymphocytic leukemia (CLL) is the main cause of autoimmune hemolytic anemia (AHA). However, the cellular basis underlying this strong association remains unclear. We previously demonstrated that leukemic B cells from patients with CLL recognize the erythrocyte protein Band 3, a prevalent autoantigen in AHA. Here we show that the major binding site of Band 3 on leukemic cells is an extrinsic protein identified as high-mobility group nucleosome binding protein 2 (HMGN2), a nucleosome-interacting factor which has not been previously reported at the cell surface. T lymphocytes do not express HMGN2 or bind Band 3. Removal of HMGN2 from the cell membrane abrogated the capacity of Band 3-pulsed CLL cells to induce CD4 + T cell proliferation. We conclude that surface HMGN2 in leukemic B cells is involved in Band 3 binding, uptake and presentation to CD4 + T lymphocytes, and as such may favor the initiation of AHA secondary to CLL.

The expression of sphingosine-1 phosphate receptor-1 in chronic lymphocytic leukemia cells is impaired by tumor microenvironmental signals and enhanced by piceatannol and R406.

Chronic lymphocytic leukemia (CLL) is characterized by the progressive accumulation of clonal B lymphocytes. Proliferation occurs in lymphoid tissues upon interaction of leukemic cells with a supportive microenvironment. Therefore, the mobilization of tissue-resident CLL cells into the circulation is a useful therapeutic strategy to minimize the reservoir of tumor cells within survival niches. Because the exit of normal lymphocytes from lymphoid tissues depends on the presence of sphingosine-1 phosphate (S1P) and the regulated expression of S1P receptor-1 (S1PR1), we investigated whether the expression and function of S1PR1 can be modulated by key microenvironment signals. We found that activation of CLL cells with CXCL12, fibroblast CD40L(+), BCR cross-linking, or autologous nurse-like cells reduces their S1PR1 expression and the migratory response toward S1P. Moreover, we found that S1PR1 expression was reduced in the proliferative/activated subset of leukemic cells compared with the quiescent subset from the same patient. Similarly, bone marrow-resident CLL cells expressing high levels of the activation marker CD38 showed a lower expression of S1PR1 compared with CD38(low) counterparts. Finally, given that treatment with BCR-associated kinase inhibitors induces a transient redistribution of leukemic cells from lymphoid tissues to circulation, we studied the effect of the Syk inhibitors piceatannol and R406 on S1PR1 expression and function. We found that they enhance S1PR1 expression in CLL cells and their migratory response toward S1P. Based on our results, we suggest that the regulated expression of S1PR1 might modulate the egress of the leukemic clone from lymphoid tissues.

Structural alterations in chronic lymphocytic leukaemia. Cytogenetic and FISH analysis.

In this study, we described cytogenetics and fluorescence in situ hybridization (FISH) analysis performed in chronic lymphocytic leukaemia (CLL) patients with structural alterations. Results were correlated with clinical characteristics. A total of 38 CLL patients: 16 cases with complex and 22 with simple karyotypes were studied. For comparison of clinical parameters, a control group of 78 CLL patients with normal karyotype and without FISH genomic alterations were also evaluated. We found 38 structural abnormalities not previously described in the literature, 28 (74%) of them were translocations. In cases with complex karyotypes, chromosomes 6, 8 and 13 were the most frequently involved in new alterations (nine each), followed by chromosomes 12, 14 and 15 (six each). Chromosome 8p was particularly involved in losses, being 8p21-pter the commonest region of overlap. Cases with simple karyotypes, showed del(6q) as the most frequent alteration (39%). Del(9)(q11) was recurrent in our series. Analysis of clinical parameters showed significant differences in white blood count (p = 0.005) and platelet count (p = 0.015) between patients with structural alterations and the control group. In addition, patients with structural alterations had a significantly shorter time to first treatment (TFT) (29 months) than the control group (69 months) (p = 0.037). Cases with complex karyotypes had a lower proportion of patients in Rai 0 clinical stage (15.4% vs 75%) (p = 0.005) and higher ß2 microglobulin levels (3.3 vs 2.5 µg/mL) (p = 0.037) than those with simple karyotypes. Furthermore, a shorter TFT (13 months) and overall survival (56 months) in the complex karyotypes group compared with controls (69 and 144 months, respectively) (p = 0.015 and p = 0.005, respectively) were also found. Our results support the importance of cytogenetic analysis for clinical outcome in CLL and suggest that the diversity of genomic alterations is much greater than previously appreciated.

The cytotoxic activity of Aplidin in chronic lymphocytic leukemia (CLL) is mediated by a direct effect on leukemic cells and an indirect effect on monocyte-derived cells.

Aplidin is a novel cyclic depsipeptide, currently in Phase II/III clinical trials for solid and hematologic malignancies. The aim of this study was to evaluate the effect of Aplidin in chronic lymphocytic leukemia (CLL), the most common leukemia in the adult. Although there have been considerable advances in the treatment of CLL over the last decade, drug resistance and immunosuppression limit the use of current therapy and warrant the development of novel agents. Here we report that Aplidin induced a dose- and time-dependent cytotoxicity on peripheral blood mononuclear cells (PBMC) from CLL patients. Interestingly, Aplidin effect was markedly higher on monocytes compared to T lymphocytes, NK cells or the malignant B-cell clone. Hence, we next evaluated Aplidin activity on nurse-like cells (NLC) which represent a cell subset differentiated from monocytes that favors leukemic cell progression through pro-survival signals. NLC were highly sensitive to Aplidin and, more importantly, their death indirectly decreased neoplasic clone viability. The mechanisms of Aplidin-induced cell death in monocytic cells involved activation of caspase-3 and subsequent PARP fragmentation, indicative of death via apoptosis. Aplidin also showed synergistic activity when combined with fludarabine or cyclophosphamide. Taken together, our results show that Aplidin affects the viability of leukemic cells in two different ways: inducing a direct effect on the malignant B-CLL clone; and indirectly, by modifying the microenvironment that allows tumor growth.

Risk-adapted therapy with three or six cycles of doxorubicin/bleomycin/vinblastine/dacarbazine plus involved-field radiation therapy in Hodgkin lymphoma, based on prognosis at diagnosis and early response: results from the GATLA study.

BACKGROUND: Doxorubicin/bleomycin/vinblastine/dacarbazine (ABVD) plus involved-field radiation therapy (IFRT) is the gold-standard treatment for early and advanced stages of Hodgkin lymphoma (HL). We evaluated the outcomes of patients according to prognosis at diagnosis and over time to determine who achieved complete remission (CR). PATIENTS AND METHODS: Treatment-naive patients under the age of 75 years at all stages of HL were eligible. The favorable group (FG) contained patients with stage IA-IIIA disease without bulky areas who achieved CR after the third cycle of ABVD. They received only IFRT at 25 Gy. Patients in the unfavorable group (UG) exhibited stages IIIB and IV HL. The UG also included all patients with bulky disease and the subset of the FG without CR after 3 cycles of ABVD, ie, slow responders (FGSR). The UG received 6 cycles of ABVD plus IFRT at 30 Gy to bulky areas at diagnosis or to those areas remaining positive after the third cycle of ABVD. RESULTS: In total, 584 patients were evaluable: 285 of them belonged to the FG, and 299 to the UG. Rates of CR were 98% and 85% for the FG and the UG, respectively (P < .001). Sixty patients in the FG received 6 cycles of ABVD because they had not achieved CR after 3 cycles (ie, the FGSR subgroup). The 5-year event-free survival rate was 89% for the FG, 66% for the FGSR, and 72% for the UG (P < .001). The overall survival at 5 years was significantly better for the FG (98%) than for the FGSR (87%) and the UG (88%; P < .001). CONCLUSION: Patients from the FG demonstrated excellent outcomes compared with those from the FGSR and UG, despite receiving less chemotherapy and fewer doses of IFRT.

Biallelic deletion 13q14.3 in patients with chronic lymphocytic leukemia: cytogenetic, FISH and clinical studies.

BACKGROUND AND OBJECTIVE: Monoallelic deletion of 13q14.3 (13q14x1) is the most common abnormality in chronic lymphocytic leukemia (CLL). As a sole alteration, it predicts a favorable outcome. Biallelic 13q14.3 (13q14x2) deletion or concomitant 13q14x1/13q14x2 has been scarcely evaluated in the literature. We present the clinical, cytogenetic and fluorescence in situ hybridization (FISH) analysis of six CLL patients with normal karyotypes and 13q14x2 and their comparison to cases with 13q14x1 as a single abnormality. PATIENTS AND METHODS: A total of 103 CLL patients were studied. Cytogenetic and FISH analysis were performed on stimulated peripheral blood lymphocytes. Specific fluorescence DNA probes for CLL were used. RESULTS: Six out of 103 (5.8%) patients showed normal karyotypes and 13q14x2. It was observed as a single alteration in one patient and combined with 13q14x1 in five cases. Biallelic clones were larger than monoallelic ones in 3/5 patients (60%). The comparison of clinical and hematological data between 13q14x1 and 13q14x2 groups showed progression of the disease in all 13q14x2 patients respect to 12/32 (37.5%) cases with 13q14x1 (P = 0.008), significant differences in the distribution by Rai stage (P = 0.042) and a tendency of a higher lactate dehydrogenase level in 13q14x2 patients (P = 0.054). Treatment free survival for 13q14x2 group was 28.5 months, shorter than those observed in patients with 13q14x1 alone (49 months). CONCLUSIONS: Our data would suggest that 13q14x2 could represent a more aggressive FISH anomaly than 13q14x1 alone, probably as a consequence of clonal evolution and/or due to the complete inactivation of this critical region by mean of more complex mechanisms.

Niveles séricos del factor de crecimiento semejante a la insulina tipo I como posible marcador de la evolución de pacientes con leucemia linfática crónica / Growth factor similar insulin like 1 serum levels as prognostic factor of patients with chronic lymphotic leukemia evolution

La leucemia linfática crónica (LLC) es una enfermedad caracterizada por la acumulación de linfocitos B,usualmente CD5+, que tienen una larga vida y se encuentran detenidos en la fase GO/1 temprana del ciclo celular debido aun defecto en su apoptosis. Como el factor de crecimiento semejante a la insulina tipo I (IGF-I) es un conocido factor antiapoptótico en diferentes tipos celulares, hemos investigado su posible participación autocrina/paracrina en las células leucémicas. Observamos que los niveles de IGF-I séricos en pacientes con LLC fueron elevados mientras que la hormona de crecimiento (HC) se mantuvo normal. Las células LLC expresaron el ARNm del IGF-I y fueron capaces de secretar el factor de crecimiento in vitro. Por lo tanto, la producción local del IGF-I puede ser responsable del aumento de los niveles séricos de IGF-I, de forma independiente de la HC y podría estar relacionada al control autocrino/paracrino de la supervivencia de los linfocitos. Más aun, los pacientes estables que tuvieron IGF-I sérico elevado, mostraron una sobrevida más corta en un seguimiento de 4 años. Nuestros hallazgos indican que los niveles séricos de IGF-I en pacientes estables podrían ser utilizados como un marcador pronóstico en LLC.

Niveles séricos del factor de crecimiento semejante a la insulina tipo I como posible marcador de la evolución de pacientes con leucemia linfática crónica / Growth factor similar insulin like 1 serum levels as prognostic factor of patients with chronic lymphotic leukemia evolution

La leucemia linfática crónica (LLC) es una enfermedad caracterizada por la acumulación de linfocitos B,usualmente CD5+, que tienen una larga vida y se encuentran detenidos en la fase GO/1 temprana del ciclo celular debido aun defecto en su apoptosis. Como el factor de crecimiento semejante a la insulina tipo I (IGF-I) es un conocido factor antiapoptótico en diferentes tipos celulares, hemos investigado su posible participación autocrina/paracrina en las células leucémicas. Observamos que los niveles de IGF-I séricos en pacientes con LLC fueron elevados mientras que la hormona de crecimiento (HC) se mantuvo normal. Las células LLC expresaron el ARNm del IGF-I y fueron capaces de secretar el factor de crecimiento in vitro. Por lo tanto, la producción local del IGF-I puede ser responsable del aumento de los niveles séricos de IGF-I, de forma independiente de la HC y podría estar relacionada al control autocrino/paracrino de la supervivencia de los linfocitos. Más aun, los pacientes estables que tuvieron IGF-I sérico elevado, mostraron una sobrevida más corta en un seguimiento de 4 años. Nuestros hallazgos indican que los niveles séricos de IGF-I en pacientes estables podrían ser utilizados como un marcador pronóstico en LLC.(AU)

Autocrine/paracrine involvement of insulin-like growth factor-I and its receptor in chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is characterized by the accumulation of long-lived B lymphocytes blocked in G(0/1) by impaired apoptosis. As insulin-like growth factor-I (IGF-I) is known for its antiapoptotic effects in different cell types, we investigated whether IGF-I and its receptor (IGF-IR) participate in autocrine/paracrine loops affecting the survival of CLL cells. IGF-IR protein and mRNA was present in CLL cells in 44% and 59% of patients respectively. IGF-IR expression in CLL patients was positively correlated with the expression of the antiapoptotic protein Bcl-2 and was involved in CLL cell survival in vitro. Serum IGF-I was elevated in CLL patients, but growth hormone (GH) was normal. CLL cells expressed IGF-I mRNA and secreted the growth factor in vitro. Therefore, local production of IGF-I can account for the increased levels of serum IGF-I, independently of GH, and may be related to autocrine/paracrine control of lymphocyte survival acting at IGF-IR. This is the first demonstration of IGF-IR expression in a subgroup of CLL patients and of its antiapoptotic effects in vitro, highlighting the importance of this growth factor receptor as a possible therapeutic target in CLL.