miR-129-5p inhibits anchorage-independent growth through silencing of ACTN1 and the ELK4/c-FOS axis in HPV-transformed keratinocytes

A persistent infection with human papillomavirus (HPV) can induce precancerous lesions of the cervix that may ultimately develop into cancer. Cervical cancer development has been linked to altered microRNA (miRNA) expression, with miRNAs regulating anchorage-independent growth being particularly important for the progression of precancerous lesions to cancer. In this study, we set out to identify and validate targets of miR-129-5p, a previously identified tumor suppressive miRNA involved in anchorage-independent growth and HPV-induced carcinogenesis. We predicted 26 potential miR-129-5p targets using online databases, followed by KEGG pathway enrichment analysis. RT-qPCR and luciferase assays confirmed that 3'UTR regions of six genes (ACTN1, BMPR2, CAMK4, ELK4, EP300, and GNAQ) were targeted by miR-129-5p. Expressions of ACTN1, CAMK4, and ELK4 were inversely correlated to miR-129-5p expression in HPV-transformed keratinocytes, and their silencing reduced anchorage-independent growth. Concordantly, miR-129-5p overexpression decreased protein levels of ACTN1, BMPR2, CAMK4 and ELK4 in anchorage-independent conditions. Additionally, c-FOS, a downstream target of ELK4, was downregulated upon miR-129-5p overexpression, suggesting regulation through the ELK4/c-FOS axis. ACTN1 and ELK4 expression was also upregulated in high-grade precancerous lesions and cervical cancers, supporting their clinical relevance. In conclusion, we identified six targets of miR-129-5p involved in the regulation of anchorage-independent growth, with ACTN1, BMPR2, ELK4, EP300, and GNAQ representing novel targets for miR-129-5p. For both ACTN1 and ELK4 functional and clinical relevance was confirmed, indicating that miR-129-5p-regulated ACTN1 and ELK4 expression contributes to HPV-induced carcinogenesis.

Downregulation of miR-193a/b-3p during HPV-induced cervical carcinogenesis contributes to anchorage-independent growth through PI3K/AKT pathway regulators

Cervical cancer is caused by a persistent infection with high-risk types of HPV and an accumulation of (epi)genetic alterations in host cell. Acquisition of anchorage-independent growth represents a critical hallmark during HPV-induced carcinogenesis, thereby yielding the most valuable biomarkers for early diagnosis and therapeutic targets. In a previous study, we found that miR-193a-3p and miR-193b-3p were involved in anchorage-independent growth. This study aimed to delineate the role of miR-193a/b-3p in HPV-induced carcinogenesis and to identify their target genes related to anchorage-independent growth. Cell viability and colony formation were assessed in SiHa cancer cells and HPV-16 and -18 immortalized keratinocytes upon miR-193a/b-3p overexpression. Both miRNAs reduced cell growth of all three cell lines in low-attachment conditions and showed a minor effect in adherent conditions. Online target predicting programs and publicly available expression data were used to find candidate mRNAs targets of miR-193a/b-3p. Seven targets showed reduced mRNA expression upon miR-193a/b-3p overexpression. For 3 targets Western blot analysis was also performed, all showing a reduced protein expression. A direct interaction was confirmed using luciferase assays for 6 genes: LAMC1, PTK2, STMN1, KRAS, SOS2, and PPP2R5C, which are PIK3/AKT regulators. All 6 targets were overexpressed in cervical cancers and/or precursor lesions. Together with an oberserved downregulation of phosphorylated-AKT upon miR-193a/b-3p overexpression, this underlines the biological relevance of miR-193a/b-3p downregulation during HPV-induced cervical carcinogenesis. In conclusion, downregulation of miR-193a-3p and miR-193b-3p is functionally involved in the acquisition of HPV-induced anchorage independence by targeting regulators of the PIK3/AKT pathway. This article is protected by copyright. All rights reserved.

[Self-harming behavior of patients on a closed psychiatric ward]

BACKGROUND

Self-harming behavior is a frequent problem seen in patients admitted to a closed ward in a psychiatric hospital. Little is known about prevalence and characteristics of this behavior as well as the preceding triggering factors.

AIM

To gain insights in the self-harming behavior of patients admitted to a closed ward in a psychiatric hospital.

METHOD

From September 2019 till January 2021 was gathered information on self-harming incidents and aggressive behavior towards others or objects, of 27 patients admitted to the closed department of the Centre Intensive Treatment (Centrum Intensieve Behandeling).

RESULTS

20 of 27 patients examined (74%) showed 470 incidents of self-harming behavior. Head banging (40.9%) and self-harming using straps/ropes (29.7%) occured most. Tension/stress as triggering factor was mentioned most (19.1%). Self-harming behavior occured more during evenings. Besides self-harm, a high degree of aggressive behavior towards others or objects was registered.

CONCLUSION

This study delivers insights in self-harming behavior of patients admitted to closed psychiatric departments that can be used for prevention and treatment.

Self-harm on a closed psychiatric ward

Introduction

Self-harming behavior is a frequent problem seen at patients admitted to closed wards in psychiatric hospitals. People who self-harm have al higher risk of other forms of aggressive behavior as well. Little is known about prevalence and characteristics of this behavior, the preceding triggering factors and the relation with other aggressive behaviors.

Objectives

To gain insights in the self-harming behavior of patients admitted to a closed ward in a psychiatric hospital.

Methods

From September 2019 till January 2021 information on self-harming incidents and aggressive behavior towards others or objects, of 27 patients admitted to the closed department of the Centre Intensive Treatment (Centrum Intensieve Behandeling), has been gathered. The Self-Harm Scale and Social Dysfunction and Agression Scale were used to gather the data.

Results

Twenty of 27 patients examined (74%) showed self-harming behavior. Head banging (41,9%) and self-harming using straps/ropes (30%) occurred most. Tension/stress as triggering factor was mentioned most (19,1%), followed by reliving (13,5%) and team interaction (11,8%). Self-harming behavior occurred more in evenings then during the rest of the day. No significant difference was found in the degree of aggressive behavior towards others or objects between the group of patients harming themselves and the group that didn’t.

Conclusions

This study delivers insights in self-harming behavior of patients admitted to closed psychiatric departments that can be used for prevention and treatment.

Disclosure

No significant relationships.

[Medulloblastoma : management of a usually pediatric tumour in a young adult]

Medulloblastoma is a cerebellar grade IV tumour according to the WHO classification, mainly seen in children under the age of 15. This cancer can nevertheless occur in adults. We report the case of a 22-year-old patient with a medulloblastoma disseminated in the spine. The patient had a type 1 Arnold-Chiari malformation causing hydrocephalus treated by ventriculoperitoneal shunt. The current condition began with perineal and lower limb hypoesthesia, ataxic gait, erectile dysfunction and urinary incontinence. Subsequently, a predominant paraparesis of the right lower limb appeared. The patient was treated according to the PNET HR+5 protocol combining two courses of conventional chemotherapy followed by two courses of high-dose chemotherapy with autograft recovery. Given the excellent response, a proton therapy was then delivered to the whole cerebrospinal axis with boosts to the primary tumour sites. The case of this young adult patient shows on the one hand an atypical presentation, and on the other hand underlines, in the absence of a specific therapeutic strategy established for adults, the importance of collaboration between the adult and pediatric oncology departments, with management integrating innovations such as proton therapy and molecular typing.

[Overview of the general management of acute leukemia for adults]

Acute leukemias are a heterogeneous group of malignant hemopathies which are subdivided according to the cytological orientation of the pathological blast cell into lymphoblastic (ALL) and myeloblastic (AML) acute leukemias. Recent advances in the biological and genetic understanding of these diseases have led to improved treatments. Specific chemotherapy treatment or so-called «targeted» treatments, advances in bone marrow transplantation and better supportive care have gradually improved the prognosis. This review, focused on the adult patient, aims to describe recent progress in terms of diagnosis, prognostic markers and therapy.

[Hemophagocytic lymphohistiocytosis on Epstein-Barr Virus reactivation]

We describe the case of a 43-years-old female patient admitted in the emergency department for impairment of general condition and dyspnea. This patient is on immunosuppressive medication for Behçet's disease and will develop a lymphoma and hemophagocytic lymphohistiocytosis following Epstein-Barr virus (EBV) reactivation. This clinical case introduces a brief literature review about hemophagocytic lymphohistiocytosis (HLH).

Identification of Deregulated Pathways, Key Regulators, and Novel miRNA-mRNA Interactions in HPV-Mediated Transformation

Next to a persistent infection with high-risk human papillomavirus (HPV), molecular changes are required for the development of cervical cancer. To identify which molecular alterations drive carcinogenesis, we performed a comprehensive and longitudinal molecular characterization of HPV-transformed keratinocyte cell lines. Comparative genomic hybridization, mRNA, and miRNA expression analysis of four HPV-containing keratinocyte cell lines at eight different time points was performed. Data was analyzed using unsupervised hierarchical clustering, integrated longitudinal expression analysis, and pathway enrichment analysis. Biological relevance of identified key regulatory genes was evaluated in vitro and dual-luciferase assays were used to confirm predicted miRNA-mRNA interactions. We show that the acquisition of anchorage independence of HPV-containing keratinocyte cell lines is particularly associated with copy number alterations. Approximately one third of differentially expressed mRNAs and miRNAs was directly attributable to copy number alterations. Focal adhesion, TGF-beta signaling, and mTOR signaling pathways were enriched among these genes. PITX2 was identified as key regulator of TGF-beta signaling and inhibited cell growth in vitro, most likely by inducing cell cycle arrest and apoptosis. Predicted miRNA-mRNA interactions miR-221-3p_BRWD3, miR-221-3p_FOS, and miR-138-5p_PLXNB2 were confirmed in vitro. Integrated longitudinal analysis of our HPV-induced carcinogenesis model pinpointed relevant interconnected molecular changes and crucial signaling pathways in HPV-mediated transformation.

Lenalidomide added to standard intensive treatment for older patients with AML and high-risk MDS

More effective treatment modalities are urgently needed in patients with acute myeloid leukemia (AML) of older age. We hypothesized that adding lenalidomide to intensive standard chemotherapy might improve their outcome. After establishing a safe lenalidomide, dose elderly patients with AML were randomly assigned in this randomized Phase 2 study (n = 222) to receive standard chemotherapy ("3 + 7") with or without lenalidomide at a dose of 20 mg/day 1-21. In the second cycle, patients received cytarabine 1000 mg/m² twice daily on days 1-6 with or without lenalidomide (20 mg/day 1-21). The CR/CRi rates in the two arms were not different (69 vs. 66%). Event-free survival (EFS) at 36 months was 19% for the standard arm versus 21% for the lenalidomide arm and overall survival (OS) 35% vs. 30%, respectively. The frequencies and grade of adverse events were not significantly different between the treatment arms. Cardiovascular toxicities were rare and equally distributed between the arms. The results of the present study show that the addition of lenalidomide to standard remission induction chemotherapy does not improve the therapeutic outcome of older AML patients. This trial is registered as number NTR2294 in The NederlandsTrial Register (www.trialregister.nl).

miR-9-5p Exerts a Dual Role in Cervical Cancer and Targets Transcription Factor TWIST1

Squamous cell carcinoma (SCC) and adenocarcinoma (AC) represent the major cervical cancer histotypes. Both histotypes are caused by infection with high-risk HPV (hrHPV) and are associated with deregulated microRNA expression. Histotype-dependent expression has been observed for miR-9-5p, showing increased expression in SCC and low expression in AC. Here, we studied the regulation and functionality of miR-9-5p in cervical SCCs and ACs using cervical tissue samples and hrHPV-containing cell lines. Expression and methylation analysis of cervical tissues revealed that low levels of miR-9-5p in ACs are linked to methylation of its precursor genes, particularly miR-9-1. Stratification of tissue samples and hrHPV-containing cell lines suggested that miR-9-5p depends on both histotype and hrHPV type, with higher expression in SCCs and HPV16-positive cells. MiR-9-5p promoted cell viability and anchorage independence in cervical cancer cell lines SiHa (SCC, HPV16) and CaSki (metastasized SCC, HPV16), while it played a tumor suppressive role in HeLa (AC, HPV18). TWIST1, a transcription factor involved in epithelial-to-mesenchymal transition (EMT), was established as a novel miR-9-5p target. Our results show that miR-9-5p plays a dual role in cervical cancer in a histotype- and hrHPV type-dependent manner. MiR-9-5p mediated silencing of TWIST1 suggests two distinct mechanisms towards EMT in cervical cancer.

Abstract 5059: Comprehensive molecular profiling of HPV-induced transformation over time

Although persistent infection with high-risk human papillomavirus (HPV) is generally acknowledged as necessary cause for cervical cancer, additional molecular changes are required for the development of cancer. Those changes include chromosomal aberrations that result in deregulated expression of coding and non-coding RNAs. In this study we performed a comprehensive and longitudinal molecular characterization of HPV-transformed keratinocyte cell lines, to identify the sequential order and relevance of these molecular alterations for HPV-induced transformation. Genome-wide chromosomal, mRNA and miRNA expression profiles were generated from 4 HPV-transformed keratinocyte cell lines at 8 different passages representing progressive stages of transformation. Unsupervised hierarchical clustering of DNA copy number, mRNA and miRNA profiles revealed that in all 4 cell lines most pronounced changes were associated with the acquisition of anchorage independence, a hallmark of transformation. Approximately one third of differentially expressed mRNAs and miRNAs was directly attributable to DNA copy number alterations. Focal adhesion, TGF-β signalling and mTOR signalling pathways were enriched among these genes. In addition, longitudinal analysis identified more than 600 potential miRNA-mRNA interactions that were negatively correlated during passaging. Four interactions were also predicted by 3 independent prediction algorithms, and have in part already been functionally validated, thereby demonstrating the validity of our approach. In conclusion, integrated longitudinal analysis of our HPV-induced transformation model enabled us to pinpoint relevant interconnected molecular changes and affected signalling pathways. Increased understanding of the interplay between different molecular alterations and affected pathways will be of importance for the clinical management of patients diagnosed with HPV-induced (pre)cancerous lesions.

Citation Format: Iris Babion, Viktorian Miok, Annelieke Jaspers, Wessel N. van Wieringen, Renske D. Steenbergen, Saskia M. Wilting. Comprehensive molecular profiling of HPV-induced transformation over time [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5059.

Triage of high-risk HPV-positive women in population-based screening by miRNA expression analysis in cervical scrapes; a feasibility study

Background

Primary testing for high-risk HPV (hrHPV) is increasingly implemented in cervical cancer screening programs. Many hrHPV-positive women, however, harbor clinically irrelevant infections, demanding additional disease markers to prevent over-referral and over-treatment. Most promising biomarkers reflect molecular events relevant to the disease process that can be measured objectively in small amounts of clinical material, such as miRNAs. We previously identified eight miRNAs with altered expression in cervical precancer and cancer due to either methylation-mediated silencing or chromosomal alterations. In this study, we evaluated the clinical value of these eight miRNAs on cervical scrapes to triage hrHPV-positive women in cervical screening.

Results

Expression levels of the eight candidate miRNAs in cervical tissue samples (n = 58) and hrHPV-positive cervical scrapes from a screening population (n = 187) and cancer patients (n = 38) were verified by quantitative RT-PCR. In tissue samples, all miRNAs were significantly differentially expressed (p < 0.05) between normal, high-grade precancerous lesions (CIN3), and/or cancer. Expression patterns detected in cervical tissue samples were reflected in cervical scrapes, with five miRNAs showing significantly differential expression between controls and women with CIN3 and cancer. Using logistic regression analysis, a miRNA classifier was built for optimal detection of CIN3 in hrHPV-positive cervical scrapes from the screening population and its performance was evaluated using leave-one-out cross-validation. This miRNA classifier consisted of miR-15b-5p and miR-375 and detected a major subset of CIN3 as well as all carcinomas at a specificity of 70%. The CIN3 detection rate was further improved by combining the two miRNAs with HPV16/18 genotyping. Interestingly, both miRNAs affected the viability of cervical cancer cells in vitro.

Conclusions

This study shows that miRNA expression analysis in cervical scrapes is feasible and enables the early detection of cervical cancer, thus underlining the potential of miRNA expression analysis for triage of hrHPV-positive women in cervical cancer screening.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0509-9) contains supplementary material, which is available to authorized users.

Aberrant methylation-mediated silencing of microRNAs contributes to HPV-induced anchorage independence

Cervical cancer and a subset of anogenital and head-and-neck carcinomas are caused by high-risk types of the human papillomavirus (hrHPV). During hrHPV-induced malignant transformation keratinocytes become able to grow anchorage independently, a tumorigenic trait at least partly associated with inactivation of tumor suppressor genes. We used hrHPV-containing keratinocytes to investigate the role of DNA methylation-mediated silencing of microRNAs (miRNAs) in the acquisition of anchorage independence.

Anchorage dependent (n=11) and independent passages (n=19) of 4 hrHPV-immortalized keratinocyte cell lines were treated with 2′-deoxy-5-azacytidine (DAC). Genome-wide miRNA expression profiles before and after treatment were compared to identify miRNAs silenced by methylation. Bisulfite sequencing and methylation-specific PCR showed increased methylation of hsa-mir-129-2/-137/-935/-3663/-3665 and -4281 in anchorage independent HPV-transformed keratinocytes and cervical cancer cell lines. Mature miRNAs derived from hsa-mir-129-2/-137/-3663 and -3665 showed functional relevance as they decreased anchorage independence in cervical cancer cell lines. Cervical (pre)cancerous lesions demonstrated increased methylation of hsa-mir-129-2/-935/-3663/-3665 and -4281, underlining the clinical relevance of our findings.

In conclusion, methylation-mediated silencing of tumor suppressive miRNAs contributes to acquisition of an anchorage independent phenotype. This study further substantiates the importance of miRNAs during early stages of carcinogenesis and underlines their potential as both disease markers and therapeutic targets.

tigaR: integrative significance analysis of temporal differential gene expression induced by genomic abnormalities

Background

To determine which changes in the host cell genome are crucial for cervical carcinogenesis, a longitudinal in vitro model system of HPV-transformed keratinocytes was profiled in a genome-wide manner. Four cell lines affected with either HPV16 or HPV18 were assayed at 8 sequential time points for gene expression (mRNA) and gene copy number (DNA) using high-resolution microarrays. Available methods for temporal differential expression analysis are not designed for integrative genomic studies.

Results

Here, we present a method that allows for the identification of differential gene expression associated with DNA copy number changes over time. The temporal variation in gene expression is described by a generalized linear mixed model employing low-rank thin-plate splines. Model parameters are estimated with an empirical Bayes procedure, which exploits integrated nested Laplace approximation for fast computation. Iteratively, posteriors of hyperparameters and model parameters are estimated. The empirical Bayes procedure shrinks multiple dispersion-related parameters. Shrinkage leads to more stable estimates of the model parameters, better control of false positives and improvement of reproducibility. In addition, to make estimates of the DNA copy number more stable, model parameters are also estimated in a multivariate way using triplets of features, imposing a spatial prior for the copy number effect.

Conclusion

With the proposed method for analysis of time-course multilevel molecular data, more profound insight may be gained through the identification of temporal differential expression induced by DNA copy number abnormalities. In particular, in the analysis of an integrative oncogenomics study with a time-course set-up our method finds genes previously reported to be involved in cervical carcinogenesis. Furthermore, the proposed method yields improvements in sensitivity, specificity and reproducibility compared to existing methods. Finally, the proposed method is able to handle count (RNAseq) data from time course experiments as is shown on a real data set.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2105-15-327) contains supplementary material, which is available to authorized users.

Abstract 2971: Methylation-mediated silencing of microRNAs during cervical carcinogenesis

Deregulated expression of microRNAs (miRNAs) is common and biologically relevant in cervical carcinogenesis and appears only partly related to chromosomal changes. We recently identified 34 miRNAs showing decreased expression in cervical high-grade precursor lesions and carcinomas not associated with a chromosomal loss, 6 of which were located within a CpG island. This study aimed to investigate to what extent these miRNAs are subject to DNA methylation-mediated silencing in cervical carcinogenesis.

Methylation-specific PCR (MSP) analysis on a cell line panel representing different stages of human papillomavirus (HPV) induced transformation revealed an increase in methylation of hsa-miR-149, -203, and -375 with progression to malignancy, whereas expression of these miRNAs was restored upon treatment with a demethylating agent. All three miRNAs showed significantly increased levels of methylation in cervical carcinomas, whereas methylation levels of hsa-miR-203 and -375 were also significantly increased in high-grade cervical intraepithelial neoplasia (CIN). A pilot analysis showed that increased hsa-miR-203 methylation was also detectable in HPV-positive cervical scrapes of women with high-grade CIN compared to controls. Similar to recent findings on hsa-miR-375, ectopic expression of hsa-miR-203 in cervical cancer cells decreased both the proliferation rate and anchorage independent growth.

We found evidence for methylation-mediated silencing of hsa-miR-149, -203 and -375 in cervical cancer. Methylation of the latter two was already apparent in precancerous lesions and represent functionally relevant events in HPV-mediated transformation. In addition, as demonstrated for hsa-miR-203, these methylated miRNAs may provide valuable markers for assessment of the presence of (pre)cancerous cervical lesions in HPV-positive women.

Citation Format: Saskia Marije Wilting, Wina Verlaat, Annelieke Jaspers, Nour A. Makazaji, Reuven Agami, Chris JLM Meijer, Peter JF Snijders, Renske DM Steenbergen. Methylation-mediated silencing of microRNAs during cervical carcinogenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2971. doi:10.1158/1538-7445.AM2013-2971

Methylation-mediated transcriptional repression of microRNAs during cervical carcinogenesis

Deregulated expression of microRNAs (miRNAs) is common and biologically relevant in cervical carcinogenesis and appears only partly related to chromosomal changes. We recently identified 32 miRNAs showing decreased expression in high-grade cervical intraepithelial neoplasia (CIN) and carcinomas not associated with a chromosomal loss, 6 of which were located within a CpG island. This study aimed to investigate to what extent these miRNAs are subject to DNA methylation-mediated transcriptional repression in cervical carcinogenesis.   Methylation-specific PCR (MSP) analysis on a cell line panel representing different stages of human papillomavirus (HPV) induced transformation revealed an increase in methylation of hsa-miR-149, -203 and -375 with progression to malignancy, whereas expression of these miRNAs was restored upon treatment with a demethylating agent. All three miRNAs showed significantly increased levels of methylation in cervical carcinomas, whereas methylation levels of hsa-miR-203 and -375 were also significantly increased in high-grade CIN. A pilot analysis showed that increased hsa-miR-203 methylation was also detectable in HPV-positive cervical scrapes of women with high-grade CIN compared with controls. Similar to recent findings on hsa-miR-375, ectopic expression of hsa-miR-203 in cervical cancer cells decreased both the proliferation rate and anchorage independent growth. We found evidence for methylation-mediated transcriptional repression of hsa-miR-149, -203 and -375 in cervical cancer. Methylation of the latter two was already apparent in precancerous lesions and represent functionally relevant events in HPV-mediated transformation. Increased hsa-miR-203 methylation was detectable in scrapes of women with high-grade CIN, indicating that methylated miRNAs may provide putative markers to assess the presence of (pre)cancerous lesions.

Focal aberrations indicate EYA2 and hsa-miR-375 as oncogene and tumor suppressor in cervical carcinogenesis

Cervical cancer results from persistent infection with high-risk human papillomavirus (hrHPV). Common genetic aberrations in cervical (pre)cancers encompass large genomic regions with numerous genes, hampering identification of driver genes. This study aimed to identify genes functionally involved in HPV-mediated transformation by analysis of focal aberrations (<3 Mb) in high-grade cervical intraepithelial neoplasia (hgCIN). Focal chromosomal aberrations were determined in high-resolution array comparative genomic hybridization data of 60 hgCIN. Genes located within focal aberrations were validated using 2 external gene expression datasets or qRT-PCR. Functional roles of candidate genes EYA2 (20q13) and hsa-miR-375 (2q35) were studied by siRNA-mediated knock-down and overexpression, respectively, in hrHPV-containing cell lines. We identified 74 focal aberrations encoding 305 genes. Concurrent altered expression in hgCIN and/or cervical carcinomas compared with normal cervical samples was shown for ATP13A3, HES1, OPA1, HRASLS, EYA2, ZMYND8, APOBEC2, and NCR2. Gene silencing of EYA2 significantly reduced viability, migratory capacity, and anchorage-independent growth of HPV16-transformed keratinocytes. For hsa-miR-375, a direct correlation between a (focal) loss and significantly reduced expression was found. Downregulation of hsa-miR-375 expression was confirmed in an independent series of cervical tissues. Ectopic expression of hsa-miR-375 in 2 cervical carcinoma cell lines reduced cellular viability. Our data provide a proof of concept that chromosomal aberrations are actively contributing to HPV-induced carcinogenesis and identify EYA2 and hsa-miR-375 as oncogene and tumor suppressor gene, respectively.

[Mantle cell lymphoma]

Mantle cell lymphoma comprises 3 to 10% of non-Hodgkin's lymphomas. Cyclin D1 expression due to t(11 ;14) (q13 ;32) is considered as a hallmark of this lymphoma and plays a pivotal role in the pathophysiology of lymphoma transformation. Median age at diagnosis ranges from 60 to 70 years, and diagnosis is often made at an advanced stage with widespread lymphadenopathy and extranodular (particularly bone marrow and gastrointestinal) infiltration. First line treatment consists of combination chemotherapy followed with autologous hematopoietic cell transplantation (HCT) in younger patients, while allogeneic HCT following non-myeloablative conditioning might have a role in patients relapsing after autologous HCT.

In vivo dynamics of stable chronic lymphocytic leukemia inversely correlate with somatic hypermutation levels and suggest no major leukemic turnover in bone marrow

Although accumulating evidence indicates that chronic lymphocytic leukemia (CLL) is a disease with appreciable cell dynamics, it remains uncertain whether this also applies to patients with stable disease. In this study, (2)H(2)O was administered to a clinically homogeneous cohort of nine stable, untreated CLL patients. CLL dynamics in blood and bone marrow were determined and compared with normal B-cell dynamics in blood from five healthy individuals who underwent a similar (2)H(2)O labeling protocol. Average CLL turnover rates (0.08-0.35% of the clone per day) were approximately 2-fold lower than average B-cell turnover rates from healthy individuals (0.34-0.89%), whereas the rate at which labeled CLL cells in blood disappeared (0.00-0.39% of B cells per day) was approximately 10-fold lower compared with labeled B cells from healthy individuals (1.57-4.24% per day). Leukemic cell turnover variables inversely correlated with the level of somatic hypermutation of the CLL clone (IgVH mutations). Although CLL cells in bone marrow had a higher level of label enrichment than CLL cells in blood, no difference between proliferation rates and proapoptotic and antiapoptotic profiles of CLL cells from these compartments was observed. These data suggest that, in stable disease, there is a biological relationship between the degree of somatic hypermutation of the CLL clone and its dynamics in vivo. Furthermore, in contrast to lymph nodes, the bone marrow does not seem to be a major CLL proliferation site.

Differential Noxa/Mcl-1 balance in peripheral versus lymph node chronic lymphocytic leukemia cells correlates with survival capacity

The gradual accumulation of chronic lymphocytic leukemia (B-CLL) cells is presumed to derive from proliferation centers in lymph nodes and bone marrow. To what extent these cells possess the purported antiapoptotic phenotype of peripheral B-CLL cells is unknown. Recently, we have described that, in B-CLL samples from peripheral blood, aberrant apoptosis gene expression was not limited to protective changes but also included increased levels of proapoptotic BH3-only member Noxa. Here, we compare apoptosis gene profiles from peripheral blood B-CLL (n = 15) with lymph node B-CLL (> 90% CD5+/CD19+/CD23+ lymphocytes with Ki67+ centers; n = 9). Apart from expected differences in Survivin and Bcl-xL, a prominent distinction with peripheral B-CLL cells was the decreased averaged level of Noxa in lymph nodes. Mcl-1 protein expression showed a reverse trend. Noxa expression could be reduced also in vitro by CD40 stimulation of peripheral blood B-CLL. Direct manipulation of Noxa protein levels was achieved by proteasome inhibition in B-CLL and via RNAi in model cell lines. In each instance, cell viability was directly linked with Noxa levels. These data indicate that suppression of Noxa in the lymph node environment contributes to the persistence of B-CLL at these sites and suggest that therapeutic targeting of Noxa might be beneficial.

CD40 stimulation of B-cell chronic lymphocytic leukaemia cells enhances the anti-apoptotic profile, but also Bid expression and cells remain susceptible to autologous cytotoxic T-lymphocyte attack

To enhance the poor antigen-presenting capacity of B-cell chronic lymphocytic leukaemia (B-CLL), CD40 triggering has been considered as an active immunotherapy. However, CD40 stimulation also has an anti-apoptotic effect and may further impair the dysregulated response of B-CLL to apoptotic stimuli. Therefore, we measured the expression of virtually all regulators of apoptosis before and after CD40 stimulation. These findings were correlated with sensitivity for chemotherapy- and death-receptor-induced apoptosis and T-cell-mediated killing. CD40 stimulation enhanced the constitutive anti-apoptotic profile of B-CLL cells by upregulation of Bcl-xL and Bfl-1 and downregulation of the BH3-only protein Harakiri. Unexpectedly, the BH3-only protein Bid was strongly induced. Functionally, CD40-stimulated B-CLL cells became resistant to drug-induced apoptosis and, despite upregulation of CD95 and Bid, were not sensitive to CD95L. In contrast, autologous T cell killing, triggered by loading CLL cells with viral (CMV) peptides, was very efficient both before and after CD40 stimulation. Upon CTL interaction, CLL targets underwent mitochondrial depolarization and caspase-3 activation. Thus, despite an increased anti-apoptotic profile, CD40 triggered B-CLL cells remain excellent targets for resident cytotoxic T cells. These data support therapeutic exploitation of CD40 stimulation in B-CLL, provided that a strong CTL component is induced.