Integrative analysis of copy number alteration and gene expression profiling in ovarian clear cell adenocarcinoma

Noninvasive early differential diagnosis and progression monitoring of ovarian cancer using the copy number alterations of plasma cell-free DNA

Ovarian cancer (OV) is the most lethal gynecological malignancy and requires improved early detection methods and more effective intervention to achieve a better prognosis. The lack of sensitive and noninvasive biomarkers with clinical utility remains a challenge. Here, we conducted a genome-wide copy number variation (CNV) profiling analysis using low-coverage whole genome sequencing (LC-WGS) of plasma cfDNA in patients with nonmalignant and malignant ovarian tumors and identified 10 malignancy-specific and 12 late-stage-specific CNV markers from plasma cfDNA LC-WGS data. Concordance analysis indicated a significant correlation of identified CNV markers between CNV profiles of plasma cfDNA and tissue DNA (Pearson's r = 0.64, P = 0.006 for the TCGA cohort and r = 0.51, P = 0.04 for the Dariush cohort). By leveraging these specific CNV markers and machine learning algorithms, we developed robust predictive models showing excellent performance in distinguishing between malignant and nonmalignant ovarian tumors with F1-scores of 0.90 and ranging from 0.75 to 0.99, and prediction accuracy of 0.89 and ranging from 0.66 to 0.98, respectively, as well as between early- and late-stage ovarian tumors with F1-scores of 0.84 and ranging from 0.61 to 1.00, and prediction accuracy of 0.82 and ranging from 0.63 to 0.96 in our institute cohort and other external validation cohorts. Furthermore, we also discovered and validated certain CNV features associated with survival outcomes and platinum-based chemotherapy response in multicenter cohorts. In conclusion, our study demonstrated the clinical utility of CNV profiling in plasma cfDNA using LC-WGS as a cost-effective and accessible liquid biopsy for OV.

Chasing Immune Checkpoint Inhibitors in Ovarian Cancer: Novel Combinations and Biomarker Discovery

A deep understanding of the tumor microenvironment and the recognition of tumor-infiltrating lymphocytes as a prognostic factor have resulted in major milestones in immunotherapy that have led to therapeutic advances in treating many cancers. Yet, the translation of this knowledge to clinical success for ovarian cancer remains a challenge. The efficacy of immune checkpoint inhibitors as single agents or combined with chemotherapy has been unsatisfactory, leading to the exploration of alternative combination strategies with targeted agents (e.g., poly-ADP-ribose inhibitors (PARP)and angiogenesis inhibitors) and novel immunotherapy approaches. Among the different histological subtypes, clear cell ovarian cancer has shown a higher sensitivity to immunotherapy. A deeper understanding of the mechanism of immune resistance within the context of ovarian cancer and the identification of predictive biomarkers remain central discovery benchmarks to be realized. This will be critical to successfully define the precision use of immune checkpoint inhibitors for the treatment of ovarian cancer.

Review the progression of ovarian clear cell carcinoma from the perspective of genomics and epigenomics

Ovarian clear cell carcinoma (OCCC) is a rare subtype of epithelial ovarian cancer with unique molecular characteristics, specific biological and clinical behavior, poor prognosis and high resistance to chemotherapy. Pushed by the development of genome-wide technologies, our knowledge about the molecular features of OCCC has been considerably advanced. Numerous studies are emerging as groundbreaking, and many of them are promising treatment strategies. In this article, we reviewed studies about the genomics and epigenetics of OCCC, including gene mutation, copy number variations, DNA methylation and histone modifications.

New insights into the role of dipeptidyl peptidase 8 and dipeptidyl peptidase 9 and their inhibitors

Dipeptidyl peptidase 8 (DPP8) and 9 (DPP9) are widely expressed in mammals including humans, mainly locate in the cytoplasm. The DPP8 and DPP9 (DPP8/9) belong to serine proteolytic enzymes, they can recognize and cleave N-terminal dipeptides of specific substrates if proline is at the penultimate position. Because the localization of DPP8/9 is different from that of DPP4 and the substrates for DPP8/9 are not yet completely clear, their physiological and pathological roles are still being further explored. In this article, we will review the recent research advances focusing on the expression, regulation, and functions of DPP8/9 in physiology and pathology status. Emerging research results have shown that DPP8/9 is involved in various biological processes such as cell behavior, energy metabolism, and immune regulation, which plays an essential role in maintaining normal development and physiological functions of the body. DPP8/9 is also involved in pathological processes such as tumorigenesis, inflammation, and organ fibrosis. In recent years, related research on immune cell pyroptosis has made DPP8/9 a new potential target for the treatment of hematological diseases. In addition, DPP8/9 inhibitors also have great potential in the treatment of tumors and chronic kidney disease.

Whole-genome/exome analysis of circulating tumor DNA and comparison to tumor genomics from patients with heavily pre-treated ovarian cancer: subset analysis of the PERMED-01 trial

Introduction

The poor prognosis of ovarian carcinoma (OvC) is due to the advanced stage at diagnosis, a high risk of relapse after first-line therapies, and the lack of efficient treatments in the recurrence setting. Circulating tumor DNA (ctDNA) analysis is a promising tool to assess treatment-resistant OvC and may avoid iterative tissue biopsies. We aimed to evaluate the genomic profile of recurrent heavily pre-treated OvC.

Methods

We performed tumor panel-based sequencing as well as low-coverage whole-genome sequencing (LC-WGS) of tumor and plasma collected in patients with ovarian cancer included in the PERMED-01 trial. Whole-exome sequencing (WES) data of plasma samples were also analyzed and compared to mutation and copy number alteration (CNA) tumor profiles. The prognostic value [progression-free survival (PFS)] of these alterations was assessed in an exploratory analysis.

Results

Tumor and plasma genomic analyses were done for 24 patients with heavily pretreated OvC [67% high-grade serous carcinoma (HGSC)]. Tumor mutation burden was low (median 2.04 mutations/Mb) and the most frequent mutated gene was TP53 (94% of HGSC). Tumor CNAs were frequent with a median of 50% of genome altered fraction. Plasma LC-WGS and WES detected ctDNA in 21/24 cases (88%) with a median tumor fraction of 12.7%. We observed a low correlation between plasma and tumor CNA profiles. However, this correlation was significant in cases with the highest circulating tumor fraction. Plasma genome altered fraction and plasma mutation burden (p = 0.011 and p = 0.041, respectively, log-rank tests) were associated with PFS.

Conclusions

Combination of LC-WGS and WES can detect ctDNA in most pre-treated OvCs. Some ctDNA characteristics, such as genome altered fraction and plasma mutation burden, showed prognostic value. ctDNA assessment with LC-WGS may be a promising and non-expansive tool to evaluate disease evolution in this disease with high genomic instability.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT02342158, identifier NCT02342158.

Identification of Candidate Genes Associated with Susceptibility to Ovarian Clear Cell Adenocarcinoma Using cis-eQTL Analysis

Ovarian clear cell adenocarcinoma (Ov-CCA) has a higher prevalence in the Japanese ancestry than other populations. The ancestral disparities in Ov-CCA prevalence suggests the presence of Ov-CCA-specific genetic alterations and may provide an opportunity to identify the novel genes associated with Ov-CCA tumorigenesis. Using 94 previously reported genes as the phenotypic trait, we conducted multistep expression quantitative trait loci (eQTL) analysis with the HapMap3 project datasets. Four single-nucleotide polymorphisms (SNPs) (rs4873815, rs12976454, rs11136002, and rs13259097) that had different allele frequencies in the Japanese ancestry and seven genes associated in cis (APBA3, C8orf58, KIAA1967, NAPRT1, RHOBTB2, TNFRSF10B, and ZNF707) were identified. In silico functional annotation analysis and in vitro promoter assay validated the regulatory effect of rs4873815-TT on ZNF707 and rs11136002-TT on TNFRSF10B. Furthermore, ZNF707 was highly expressed in Ov-CCA and had a negative prognostic value in disease recurrence in our sample cohort. This prognostic power was consistently observed in The Cancer Genome Atlas (TCGA) clear cell renal cell carcinoma dataset, suggesting that ZNF707 may have prognostic value in clear cell histology regardless of tissue origin. In conclusion, rs4873815-TT/ZNF707 may have clinical significance in the prognosis and tumorigenesis of Ov-CCA, which may be more relevant to clear cell histology. Besides, this study may underpin the evidence that cis-eQTL analysis based on ancestral disparities can facilitate the discovery of causal genetic alterations in complex diseases, such as cancer.

CD26/DPP4 - a potential biomarker and target for cancer therapy

CD26/dipeptidyl peptidase (DPP)4 is a membrane-bound protein found in many cell types of the body, and a soluble form is present in body fluids. There is longstanding evidence that various primary tumors and also metastases express CD26/DPP4 to a variable extent. By cleaving dipeptides from peptides with a proline or alanine in the penultimate position at the N-terminus, it regulates the activity of incretin hormones, chemokines and many other peptides. Due to these effects and interactions with other molecules, a tumor promoting or suppressing role can be attributed to CD26/DPP4. In this review, we discuss the existing evidence on the expression of soluble or membrane-bound CD26/DPP4 in malignant diseases, along with the most recent findings on CD26/DPP4 as a therapeutic target in specific malignancies. The expression and possible involvement of the related DPP8 and DPP9 in cancer are also reviewed. A higher expression of CD26/DPP4 is found in a wide variety of tumor entities, however more research on CD26/DPP4 in the tumor microenvironment is needed to fully explore its use as a tumor biomarker. Circulating soluble CD26/DPP4 has also been studied as a cancer biomarker, however, the observed decrease in most cancer patients does not seem to be cancer specific. Encouraging results from experimental work and a recently reported first phase clinical trial targeting CD26/DPP4 in mesothelioma, renal and urological tumors pave the way for follow-up clinical studies, also in other tumor entities, possibly leading to the development of more effective complementary therapies against cancer.

Genomics to immunotherapy of ovarian clear cell carcinoma: Unique opportunities for management

Ovarian clear cell carcinoma (OCCC) is distinctive from other histological types of epithelial ovarian cancer, with genetic/epigenetic alterations, a specific immune-related molecular profile, and epidemiologic associations with ethnicity and endometriosis. These findings allow for the exploration of unique and specific treatments for OCCC. Two major mutated genes in OCCC are PIK3CA and ARID1A, which are frequently coexistent with each other. Other genes' alterations also contribute to activation of the PI3K (e.g. PIK3R1 and PTEN) and dysregulation of the chromatin remodeling complex (e.g. ARID1B, and SMARKA4). Although the number of focal copy number variations is small in OCCC, amplification is recurrently detected at chromosome 20q13.2 (including ZNF217), 8q, and 17q. Both expression and methylation profiling highlight the significance of adjustments to oxidative stress and inflammation. In particular, up-regulation of HNF-1β resulting from hypomethylation contributes to the switch from anaerobic to aerobic glucose metabolism. Additionally, up-regulation of HNF-1β activates STAT3 and NF-κB signaling, and leads to immune suppression via production of IL-6 and IL-8. Immune suppression may also be induced by the increased expression of PD-1, Tim-3 and LAG3. Mismatch repair deficient (microsatellite instable) tumors as found in Lynch syndrome also induce immune suppression in some OCCC. In a recent phase II clinical trial in heavily-treated platinum-resistant ovarian cancer, two out of twenty cases with a complete response to the anti-PD-1 antibody, nivolumab, were OCCC subtypes. Thus, the immune-suppressive state resulting from both genetic alterations and the unique tumor microenvironment may be associated with sensitivity to immune checkpoint inhibitors in OCCC. In this review, we highlight recent update and progress in OCCC from both the genomic and immunologic points of view, addressing the future candidate therapeutic options.

Comprehensive assessment of the expression of the SWI/SNF complex defines two distinct prognostic subtypes of ovarian clear cell carcinoma

Somatic mutations in the ARID1A tumor-suppressor gene have been frequently identified in ovarian clear cell carcinoma (CCC) cases. BAF250a encoded by ARID1A is a member of the SWI/SNF complex, but the expression and mutation status of other SWI/SNF subunits have not been explored. The current study aimed to elucidate the biological and clinical significance of the SWI/SNF complex subunits, by assessing the expression and mutation status of SWI/SNF subunits, and distinct genomic aberrations associated with their expression. Of 82 CCC specimens, 38 samples presented no BAF250a expression, and 50 samples exhibited the loss of at least one subunit of the SWI/SNF complex. Cases which lack at least one SWI/SNF complex component exhibited significantly more advanced stages, faster growth and stronger nuclear atypia compared with SWI/SNF-positive samples (p<0.05). Although BAF250a expression is not related to poor prognosis, the group presenting the loss of at least one SWI/SNF complex subunit exhibited significantly shorter overall and progression-free survivals (p<0.05). A multivariate analysis suggested that the expression status of the SWI/SNF complex serves as an independent prognostic factor (p<0.005). The cases positive for all SWI/SNF subunits demonstrated significantly greater DNA copy number alterations, such as amplification at chromosomes 8q.24.3 and 20q.13.2-20q.13.33 (including ZNF217) and deletion at chromosomes 13q12.11-13q14.3 (including RB1), 17p13.2-17p13.1 (including TP53) and 19p13.2-19p13.12. In conclusion, the CCCs exhibiting the loss of one or multiple SWI/SNF complex subunits demonstrated aggressive behaviors and poor prognosis, whereas the CCCs with positive expression for all SWI/SNF components presented more copy number alterations and a favorable prognosis.

Integrated Analysis of Genome-Wide Copy Number Alterations and Gene Expression Profiling of Lung Cancer in Xuanwei, China

Objectives

Lung cancer in Xuanwei (LCXW), China, is known throughout the world for its distinctive characteristics, but little is known about its pathogenesis. The purpose of this study was to screen potential novel “driver genes” in LCXW.

Methods

Genome-wide DNA copy number alterations (CNAs) were detected by array-based comparative genomic hybridization and differentially expressed genes (DEGs) by gene expression microarrays in 8 paired LCXW and non-cancerous lung tissues. Candidate driver genes were screened by integrated analysis of CNAs and DEGs. The candidate genes were further validated by real-time quantitative polymerase chain reaction.

Results

Large numbers of CNAs and DEGs were detected, respectively. Some of the most frequently occurring CNAs included gains at 5p15.33-p15.32, 5p15.1-p14.3, and 5p14.3-p14.2 and losses at 11q24.3, 21q21.1, 21q22.12-q22.13, and 21q22.2. Integrated analysis of CNAs and DEGs identified 24 candidate genes with frequent copy number gains and concordant upregulation, which were considered potential oncogenes, including CREB3L4, TRIP13, and CCNE2. In addition, the analysis identified 19 candidate genes with a negative association between copy number change and expression change, considered potential tumor suppressor genes, including AHRR, NKD2, and KLF10. One of the most studied oncogenes, MYC, may not play a carcinogenic role in LCXW.

Conclusions

This integrated analysis of CNAs and DEGs identified several potential novel LCXW-related genes, laying an important foundation for further research on the pathogenesis of LCXW and identification of novel biomarkers or therapeutic targets.

Feasibility of urinary microRNA profiling detection in intrahepatic cholestasis of pregnancy and its potential as a non-invasive biomarker

Intrahepatic cholestasis of pregnancy (ICP), a pregnancy-related liver disease, leads to complications for both mother and fetus. Circulating microRNAs (miRNAs) have emerged as candidate biomarkers for many diseases. So far, the circulating miRNAs profiling of ICP has not been investigated. To assess the urinary miRNAs as non-invasive biomarkers for ICP, a differential miRNA profiling was initially analyzed by individual quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay in urinary samples from a screening set including 10 ICP and 10 healthy pregnancies. The selected candidate miRNAs were then validated by a validation set with 40 ICP and 50 healthy pregnancies using individual qRT-PCR assay. Compared with the expression in urine of healthy pregnant women, the expression levels of hsa-miR-151-3p and hsa-miR-300 were significantly down-regulated, whereas hsa-miR-671-3p and hsa-miR-369-5p were significantly up-regulated in urine from ICP patients (p < 0.05 and false discovery rate < 0.05). A binary logistic regression model was constructed using the four miRNAs. The area under the receiver operating characteristic curve was 0.913 (95% confidence interval = 0.847 to 0.980; sensitivity = 82.9%, specificity = 87.0%). Therefore, urinary microRNA profiling detection in ICP is feasible and maternal urinary miRNAs have the potential to be non-invasive biomarkers for the diagnosis of ICP.

MicroRNA Species in Follicular Fluid Associating With Polycystic Ovary Syndrome and Related Intermediary Phenotypes

CONTEXT

Polycystic ovary syndrome (PCOS) has a largely unknown etiology and presents with a clinical heterogeneous patient group. Small noncoding microRNA (miRNA) might prove promising as biomarker candidates for PCOS patient stratification. Altered miRNA expression profiles have been observed in few studies.

OBJECTIVE

The aim was to assess the miRNA expression profile in follicular fluid from PCOS patients and healthy, regularly cycling, matched controls.

DESIGN AND SETTING

Experimental case-control study including 49 PCOS women (19 of which were hyperandrogenic and 30 normo-androgenic) and 21 healthy matched women all undergoing in vitro fertilization treatment.

INTERVENTIONS AND MAIN OUTCOME

Anthropometric and relevant clinical baseline measurements were obtained. Relative expression of miRNA levels were estimated using miRNA quantitative PCR arrays and validated by quantitative RT-PCR. Correlation between miRNAs and clinical relevant measurements was estimated.

RESULTS

PCOS women, both normo-androgenic and hyperandrogenic, had decreased levels of miR-24-3p, -29a, -151-3p, and -574-3p compared with controls. Furthermore, miR-518f-3p was differentially expressed within the PCOS group with high levels observed in the hyperandrogenic group compared with the normo-androgenic PCOS patients. Serum levels of total and free T were positively correlated with miR-518f-3p in PCOS subjects (P = .001). Distinction between PCOS and controls could be made using miR-151-3p alone with an area under the curve of 0.91 or a combination of four selected miRNAs (area under the curve, 0.93). Bioinformatic target analysis points to an involvement of these miRNAs in biological pathways involving regulation of cell proliferation, extracellular matrix, and processes in intermediary metabolism.

CONCLUSION

Our study provides evidence that the miRNA expression profile in follicular fluid is altered in PCOS and indicates that specific follicular fluid miRNAs are associated with phenotypical traits of PCOS. An altered miRNA profile holds potentials for new methods of PCOS patient stratification and may contribute to and in part explain the heterogeneous nature found within PCOS women.

Identification of ovarian cancer subtype-specific network modules and candidate drivers through an integrative genomics approach

Identification of cancer subtypes and associated molecular drivers is critically important for understanding tumor heterogeneity and seeking effective clinical treatment. In this study, we introduced a simple but efficient multistep procedure to define ovarian cancer types and identify core networks/pathways and driver genes for each subtype by integrating multiple data sources, including mRNA expression, microRNA expression, copy number variation, and protein-protein interaction data. Applying similarity network fusion approach to a patient cohort with 379 ovarian cancer samples, we found two distinct integrated cancer subtypes with different survival profiles. For each ovarian cancer subtype, we explored the candidate oncogenic processes and driver genes by using a network-based approach. Our analysis revealed that alterations in DLST module involved in metabolism pathway and NDRG1 module were common between the two subtypes. However, alterations in the RB signaling pathway drove distinct molecular and clinical phenotypes in different ovarian cancer subtypes. This study provides a computational framework to harness the full potential of large-scale genomic data for discovering ovarian cancer subtype-specific network modules and candidate drivers. The framework may also be used to identify new therapeutic targets in a subset of ovarian cancers, for which limited therapeutic opportunities currently exist.

Discovering potential cancer driver genes by an integrated network-based approach

An integrated network-based approach is proposed to nominate driver genes. It is composed of two steps including a network diffusion step and an aggregated ranking step, which fuses the correlation between the gene mutations and gene expression, the relationship between the mutated genes and the heterogeneous characteristic of the patient mutation.

Copy Number Gains at 8q24 and 20q11-q13 in Gastric Cancer Are More Common in Intestinal-Type than Diffuse-Type

The present study was aimed at discovering DNA copy number alterations (CNAs) involved in the carcinogenesis of stomach and at understanding their clinicopathological significances in the Korean population. DNA copy numbers were analyzed using Agilent 244K or 400K array comparative genomic hybridization (aCGH) in fresh-frozen tumor and matched normal tissues from 40 gastric cancer patients. Some of the detected CNA regions were validated using multiplex ligation-dependent probe amplification (MLPA) in six of the 40 patients and customized Agilent 60K aCGH in an independent set of 48 gastric cancers. The mRNA levels of genes at common CNA regions were analyzed using quantitative real-time PCR. Copy number gains were more common than losses across the entire genome in tumor tissues compared to matched normal tissues. The mean number of alterations per case was 64 for gains and 40 for losses, and the median aberration length was 44016 bp for gains and 4732 bp for losses. Copy number gains were frequently detected at 7p22.1 (20%), 8q24.21 (27%-30%), 8q24.3 (22%-48%), 13q34 (20%-31%), and 20q11-q13 (25%-30%), and losses at 3p14.2 (43%), 4q35.2 (27%), 6q26 (23%), and 17p13.3 (20%-23%). CNAs at 7p22.1, 13q34, and 17p13.3 have not been reported in other populations. Most of the copy number losses were associated with down-regulation of mRNA levels, but the correlation between copy number gains and mRNA expression levels varied in a gene-dependent manner. In addition, copy number gains tended to occur more commonly in intestinal-type cancers than in diffuse-type cancers. In conclusion, the present study suggests that copy number gains at 8q24 and 20q11-q13 and losses at 3p14.2 may be common events in gastric cancer but CNAs at 7p22.1, 13q34, and 17p13.3 may be Korean-specific.

Multifocal endometriotic lesions associated with cancer are clonal and carry a high mutation burden

Endometriosis is a significant risk factor for clear cell and endometrioid ovarian cancers and is often found contiguous with these cancers. Using whole‐genome shotgun sequencing of seven clear cell ovarian carcinomas (CCC) and targeted sequencing in synchronous endometriosis, we have investigated how this carcinoma may evolve from endometriosis. In every case we observed multiple tumour‐associated somatic mutations in at least one concurrent endometriotic lesion. ARID1A and PIK3CA mutations appeared consistently in concurrent endometriosis when present in the primary CCC. In several cases, one or more endometriotic lesions carried the near‐complete complement of somatic mutations present in the index CCC tumour. Ancestral mutations were detected in both tumour‐adjacent and ‐distant endometriotic lesions, regardless of any cytological atypia. These findings provide objective evidence that multifocal benign endometriotic lesions are clonally related and that CCCs arising in these patients progress from endometriotic lesions that may already carry sufficient cancer‐associated mutations to be considered neoplasms themselves, albeit with low malignant potential. We speculate that genomically distinct classes of endometriosis exist and that ovarian endometriosis with high mutational burden represents one class at high risk for malignant transformation. © 2015 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Identification of multiple DNA copy number alterations including frequent 8p11.22 amplification in conjunctival squamous cell carcinoma

PURPOSE

Little is known about the molecular alterations that drive formation and growth of conjunctival squamous cell carcinoma (cSCC). We therefore sought to identify genetic changes that could be used as diagnostic markers or therapeutic targets.

METHODS

The DNA extracted from 10 snap-frozen cSCC tumor specimens and 2 in situ carcinomas was analyzed using array-based comparative genomic hybridization (aCGH), and further examined with NanoString and quantitative PCR.

RESULTS

The number of regions of DNA loss ranged from 1 to 23 per tumor, whereas gains and amplifications ranged from 1 to 15 per tumor. Most large regions of chromosomal gain and loss were confirmed by NanoString karyotype analysis. The commonest alteration was amplification of 8p11.22 in 9 tumors (75%), and quantitative PCR analysis revealed 100-fold or greater overexpression of ADAM3A mRNA from 8p11.22 locus. In addition, recurring losses were observed at 14q13.2 and 22q11.23, both lost in 5 (42%) of the 12 tumors, and at 12p13.31, lost in 4 (33%) of the 12 samples. Of the eight loci associated with the DNA damage repair syndrome xeroderma pigmentosum, three showed loss of at least one allele in our aCGH analysis, including XPA (9q22.33, one tumor), XPE/DDB2 (11p11.2, one tumor) and XPG/ERCC5 (13q33.1, three tumors).

CONCLUSIONS

Conjunctival SCC contains a range of chromosomal alterations potentially important in tumor formation and growth. Amplification of 8p11.22 and overexpression of ADAM3A suggests a potential role for this protease. Our findings also suggest that defects in DNA repair loci are important in sporadic cSCC.

Constitutional and somatic deletions of the Williams-Beuren syndrome critical region in non-Hodgkin lymphoma

Here, we report and investigate the genomic alterations of two novel cases of Non-Hodgkin Lymphoma (NHL) in children with Williams-Beuren syndrome (WBS), a multisystem disorder caused by 7q11.23 hemizygous deletion. Additionally, we report the case of a child with NHL and a somatic 7q11.23 deletion. Although the WBS critical region has not yet been identified as a susceptibility locus in NHL, it harbors a number of genes involved in DNA repair. The high proportion of pediatric NHL reported in WBS is intriguing. Therefore, the role of haploinsufficiency of genes located at 7q11.23 in lymphomagenesis deserves to be investigated.