María Begoña García-Cenador

Expression of MALT1 oncogene in hematopoietic stem/progenitor cells recapitulates the pathogenesis of human lymphoma in mice

Chromosomal translocations involving the MALT1 gene are hallmarks of mucosa-associated lymphoid tissue (MALT) lymphoma. To date, targeting these translocations to mouse B cells has failed to reproduce human disease. Here, we induced MALT1 expression in mouse Sca1+Lin− hematopoietic stem/progenitor cells, which showed NF-κB activation and early lymphoid priming, being selectively skewed toward B-cell differentiation. These cells accumulated in extranodal tissues and gave rise to clonal tumors recapitulating the principal clinical, biological, and molecular genetic features of MALT lymphoma. Deletion of p53 gene accelerated tumor onset and induced transformation of MALT lymphoma to activated B-cell diffuse large-cell lymphoma (ABC-DLBCL). Treatment of MALT1-induced lymphomas with a specific inhibitor of MALT1 proteolytic activity decreased cell viability, indicating that endogenous Malt1 signaling was required for tumor cell survival. Our study shows that human-like lymphomas can be modeled in mice by targeting MALT1 expression to hematopoietic stem/progenitor cells, demonstrating the oncogenic role of MALT1 in lymphomagenesis. Furthermore, this work establishes a molecular link between MALT lymphoma and ABC-DLBCL, and provides mouse models to test MALT1 inhibitors. Finally, our results suggest that hematopoietic stem/progenitor cells may be involved in the pathogenesis of human mature B-cell lymphomas.

Cancer as a reprogramming-like disease: implications in tumor development and treatment.

Cancer is a clonal malignant disease originated in a single cell and characterized by the accumulation of partially differentiated cells that are phenotypically reminiscent of normal stages of differentiation. Given the fact that human cancer is diagnosed at later stages and cannot be monitored during its natural evolution, the origin of tumors has been a subject of continuing discussion. Animal models provide a means to determine the identity of the cell-of-origin leading to malignancy and to develop new treatments. Recent findings in mice have shown that cancer stem cells could arise through a reprogramming-like mechanism, suggesting that genetic lesions that initiate the cancer process might be dispensable for tumor progression and maintenance. This review addresses the impact of these results toward a better understanding of carcinogenesis and proposes research avenues for tackling these issues in the future.

Infection Exposure Is a Causal Factor in B-cell Precursor Acute Lymphoblastic Leukemia as a Result of Pax5-Inherited Susceptibility.

UNLABELLED Earlier in the past century, infections were regarded as the most likely cause of childhood B-cell precursor acute lymphoblastic leukemia (pB-ALL). However, there is a lack of relevant biologic evidence supporting this hypothesis. We present in vivo genetic evidence mechanistically connecting inherited susceptibility to pB-ALL and postnatal infections by showing that pB-ALL was initiated in Pax5 heterozygous mice only when they were exposed to common pathogens. Strikingly, these murine pB-ALLs closely resemble the human disease. Tumor exome sequencing revealed activating somatic, nonsynonymous mutations of Jak3 as a second hit. Transplantation experiments and deep sequencing suggest that inactivating mutations in Pax5 promote leukemogenesis by creating an aberrant progenitor compartment that is susceptible to malignant transformation through accumulation of secondary Jak3 mutations. Thus, treatment of Pax5(+/-) leukemic cells with specific JAK1/3 inhibitors resulted in increased apoptosis. These results uncover the causal role of infection in pB-ALL development. SIGNIFICANCE These results demonstrate that delayed infection exposure is a causal factor in pB-ALL. Therefore, these findings have critical implications for the understanding of the pathogenesis of leukemia and for the development of novel therapies for this disease.

Comparison of sublingual therapeutic vaccine with antibiotics for the prophylaxis of recurrent urinary tract infections.

Objective: To compare the clinical impact of a prophylactic treatment with sublingual immunostimulation in the prevention of recurrent urinary tract infections (rUTIs) with the use of antibiotics. Material and Methods: Retrospective cohort study evaluating the medical records of 669 women with rUTIs; 339 had a 6-month prophylaxis with antibiotics and 360 a 3-month prophylaxis with a sublingual bacterial preparation (MV 140-Uromune®). The time frame after the prophylaxis-period until the appearance of a new infection (assessed by uroculture) was scored and followed during 1 year. The absolute risk reduction (ARR) and number needed to treat (NNT) were also calculated. Results: All patients treated with antibiotics experienced a new UTI during the scoring period of 12 months, being 19 days the median number of days free of UTIs (range 5–300). In the group treated with the bacterial preparation, 35 (9.7%) patients experienced an UTI in the same period. Kaplan-Meier curves comparing the accumulated survival (disease-free time) between both groups were significant different (P < 0.0001). The absolute risk reduction (ARR) was 90.28% (87.18–93.38) and the number needed to treat (NNT) 1.1 (1.1–1.1). Conclusions: These results suggest that the treatment with this bacterial preparation significantly reduces the incidence of rUTIs, arising as an effective strategy to reduce the frequency of rUTIs. It reduces antibiotic consumption, matching the current recommendations due to the raise of antimicrobial resistance. Randomized, double-blind and placebo-controlled, clinical trials are needed to establish, more accurately, the clinical impact of this bacterial preparation in patients with rUTIs.

Infection exposure promotes ETV6-RUNX1 precursor B cell leukemia via impaired H3K4 demethylases

ETV6-RUNX1 is associated with the most common subtype of childhood leukemia. As few ETV6-RUNX1 carriers develop precursor B-cell acute lymphocytic leukemia (pB-ALL), the underlying genetic basis for development of full-blown leukemia remains to be identified, but the appearance of leukemia cases in time-space clusters keeps infection as a potential causal factor. Here, we present in vivo genetic evidence mechanistically connecting preleukemic ETV6-RUNX1 expression in hematopoetic stem cells/precursor cells (HSC/PC) and postnatal infections for human-like pB-ALL. In our model, ETV6-RUNX1 conferred a low risk of developing pB-ALL after exposure to common pathogens, corroborating the low incidence observed in humans. Murine preleukemic ETV6-RUNX1 pro/preB cells showed high Rag1/2 expression, known for human ETV6-RUNX1 pB-ALL. Murine and human ETV6-RUNX1 pB-ALL revealed recurrent genomic alterations, with a relevant proportion affecting genes of the lysine demethylase (KDM) family. KDM5C loss of function resulted in increased levels of H3K4me3, which coprecipitated with RAG2 in a human cell line model, laying the molecular basis for recombination activity. We conclude that alterations of KDM family members represent a disease-driving mechanism and an explanation for RAG off-target cleavage observed in humans. Our results explain the genetic basis for clonal evolution of an ETV6-RUNX1 preleukemic clone to pB-ALL after infection exposure and offer the possibility of novel therapeutic approaches. Cancer Res; 77(16); 4365-77. ©2017 AACR.

PDE-5 inhibitors in monotherapy versus combination therapy in a sample of 1200 patients with erectile dysfunction

OBJECTIVES To compare the effectiveness in the treatment of erectile dysfunction when using PDE-5 inhibitors (PDE5i), alprostadil (PG-E1) and testosterone (TES) in monotherapy or combination therapy. MATERIAL AND METHODS Observational multicentre retrospective study of men diagnosed and treated for ED between January 2008 and January 2014. Age, social and employment situation, pathological medical history, risk factors, usual treatments, IIEF-5 at the first consultation and at first and each 6 months follow-ups, physical examination, calculated total and free testosterone and received treatment were analysed. Descriptive statistics, one-way ANOVA analysis, Chi2 for qualitative data, t-test, Fishers exact test and Pearsons correlation coefficient were used; p < 0.05 is considered significant. RESULTS Average age was 58.61 years, SD5.02, average follow- up time 48.21 months, SD 6.21, range 6-174 months. Out of the patients 76.12% were married, 9.81% divorced/separated, 10.04% single, 4.03% widowed; 85.14% of the total in stable partnership but 66.16% were not accompanied by their partners. In total 844 patients received monotherapy (597 PDE5i; 62 PG-E1; 36 TES; 27 penile prosthesis; 121 psychotherapy/alternative therapies) and 357 combination therapy (167 PDE5i+TES; 124 PDE5i+PGE1; 66 PG-E1+TES). There was a homogeneous distribution between risk factors and medical history groups. Satisfactory response according to IIEF-5 was achieved for 72.33% of patients on PDE5i monotherapy, 46.65% of patients on PDE5i+PG-E1 combination therapy and 83.41% of patients on PDE5i+TES. CONCLUSIONS The best therapeutic success for ED in this series was achieved through a combination of testosterone+PDE-5 inhibitors without increasing morbidity and maintaining the response over time. Larger studies with longer follow-up will corroborate these findings.

Genetic background affects susceptibility to tumoral stem cell reprogramming

The latest studies of the interactions between oncogenes and its target cell have shown that certain oncogenes may act as passengers to reprogram tissue-specific stem/progenitor cell into a malignant cancer stem cell state. In this study, we show that the genetic background influences this tumoral stem cell reprogramming capacity of the oncogenes using as a model the Sca1-BCRABLp210 mice, where the type of tumor they develop, chronic myeloid leukemia (CML), is a function of tumoral stem cell reprogramming. Sca1-BCRABLp210 mice containing FVB genetic components were significantly more resistant to CML. However, pure Sca1-BCRABLp210 FVB mice developed thymomas that were not seen in the Sca1-BCRABLp210 mice into the B6 background. Collectively, our results demonstrate for the first time that tumoral stem cell reprogramming fate is subject to polymorphic genetic control.

The Making of Leukemia

Due to the clonal nature of human leukemia evolution, all leukemic cells carry the same leukemia-initiating genetic lesions, independently of the intrinsic tumoral cellular heterogeneity. However, the latest findings have shown that the mode of action of oncogenes is not homogeneous throughout the developmental history of leukemia. Studies on different types of hematopoietic tumors have shown that the contribution of oncogenes to leukemia is mainly mediated through the epigenetic reprogramming of the leukemia-initiating target cell. This driving of cancer by a malignant epigenetic stem cell rewiring is, however, not exclusive of the hematopoietic system, but rather represents a common tumoral mechanism that is also at work in epithelial tumors. Tumoral epigenetic reprogramming is therefore a new type of interaction between genes and their target cells, in which the action of the oncogene modifies the epigenome to prime leukemia development by establishing a new pathological tumoral cellular identity. This reprogramming may remain latent until it is triggered by either endogenous or environmental stimuli. This new view on the making of leukemia not only reveals a novel function for oncogenes, but also provides evidence for a previously unconsidered model of leukemogenesis, in which the programming of the leukemia cellular identity has already occurred at the level of stem cells, therefore showing a role for oncogenes in the timing of leukemia initiation.

Loss of Pax5 exploits Sca1-BCR-ABLp190 susceptibility to confer the metabolic shift essential for pB-ALL

Preleukemic clones carrying BCR-ABLp190 oncogenic lesions are found in neonatal cord blood, where the majority of preleukemic carriers do not convert into precursor B-cell acute lymphoblastic leukemia (pB-ALL). However, the critical question of how these preleukemic cells transform into pB-ALL remains undefined. Here, we model a BCR-ABLp190 preleukemic state and show that limiting BCR-ABLp190 expression to hematopoietic stem/progenitor cells (HS/PC) in mice (Sca1-BCR-ABLp190) causes pB-ALL at low penetrance, which resembles the human disease. pB-ALL blast cells were BCR-ABL-negative and transcriptionally similar to pro-B/pre-B cells, suggesting disease onset upon reduced Pax5 functionality. Consistent with this, double Sca1-BCR-ABLp190+Pax5+/- mice developed pB-ALL with shorter latencies, 90% incidence, and accumulation of genomic alterations in the remaining wild-type Pax5 allele. Mechanistically, the Pax5-deficient leukemic pro-B cells exhibited a metabolic switch toward increased glucose utilization and energy metabolism. Transcriptome analysis revealed that metabolic genes (IDH1, G6PC3, GAPDH, PGK1, MYC, ENO1, ACO1) were upregulated in Pax5-deficient leukemic cells, and a similar metabolic signature could be observed in human leukemia. Our studies unveil the first in vivo evidence that the combination between Sca1-BCR-ABLp190 and metabolic reprogramming imposed by reduced Pax5 expression is sufficient for pB-ALL development. These findings might help to prevent conversion of BCR-ABLp190 preleukemic cells.Significance: Loss of Pax5 drives metabolic reprogramming, which together with Sca1-restricted BCR-ABL expression enables leukemic transformation. Cancer Res; 78(10); 2669-79. ©2018 AACR.

Results of the surgical correction of urinary stress incontinence according to the type of transobturator tape utilized

OBJECTIVES To analyze the short and long term results of tapes of different materials used to treat stress urinary incontinence (SUI). A secondary objective was to evaluate the ability to adjust the tape after implantation. MATERIALS AND METHODS Retrospective chart review of 355 patients with SUI operated between March 2003 and October 2011. Eight different types of transobturator tapes were used: Gynecare TVT-O®, Monarc®, SAFYRE®, Contasure KIM®, I-Stop®, DynaMesh®, Aris® Bandellete and Swing-band®. Results and complications were recorded. RESULTS The mean age at operation was 61 years. Correction of SUI was achieved in 87.88% of cases. The best results were obtained with Contasure KIM® (98.26 % continence). The tape was well tolerated and was elastic enough to be able to be adjusted 48-72 hours after implantation without deformation. Slings with macropores and over lock stitches on the superior and inferior borders presented the lower rates of postoperative urinary retention, pain, perior postoperative bleeding and urinary tract infections. CONCLUSIONS Transobturator tension free tapes require a short operation time and have a low complication rate. The possibility of adjustment in the early postoperative period increases the success rate and reduces complications. Knotless meshes with macropores and over lock stitches appear to be better balanced, are quite resistant to stretching and deformation when readjusted after implantation and present a low infection rate.