SOX11 expression correlates to promoter methylation and regulates tumor growth in hematopoietic malignancies

SOX on tumors, a comfort or a constraint?

The sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) family, composed of 20 transcription factors, is a conserved family with a highly homologous HMG domain. Due to their crucial role in determining cell fate, the dysregulation of SOX family members is closely associated with tumorigenesis, including tumor invasion, metastasis, proliferation, apoptosis, epithelial-mesenchymal transition, stemness and drug resistance. Despite considerable research to investigate the mechanisms and functions of the SOX family, confusion remains regarding aspects such as the role of the SOX family in tumor immune microenvironment (TIME) and contradictory impacts the SOX family exerts on tumors. This review summarizes the physiological function of the SOX family and their multiple roles in tumors, with a focus on the relationship between the SOX family and TIME, aiming to propose their potential role in cancer and promising methods for treatment.

SOX10 promotes the malignant biological behavior of basal-like breast cancer cells by regulating EMT process

Background

The diagnostic utility of SRY-box transcription factor 10 (SOX10) expression in basal-like breast cancer (BLBC) has been reported previously. However, the effect of SOX10 on the malignancy of BLBC cells and the underlying molecular mechanisms remain unelucidated. Here, we investigate the regulatory mechanisms and roles of SOX10 in BLBC progression.

Methods

Sequencing data from patients with BLBC were extracted from the Cancer Genome Atlas database to determine the transcriptomic levels of SOX10 across breast cancer subtypes. Subsequently, the bioinformatics relevance of SOX10 in BLBC was investigated. Immunohistochemical assays were used to corroborate the protein expression of SOX10 in clinicopathological specimens (human breast cancer paraffin tissues). RNA interference was used to downregulate SOX10 expression, and the efficiency of interference was evaluated using quantitative PCR. The expression levels of molecules related to the epithelial-mesenchymal transition (EMT) pathway were determined by western blotting. Various assays, such as transwell, colony formation, and flow apoptosis assays, were conducted to assess the malignancy of BLBC cells (MDA-MB-231).

Results

Bioinformatics analyses revealed the differential expression of SOX10 in various breast cancer subtypes. An association between SOX10 and immune checkpoint expression was observed in BLBC. Additionally, immune correlation analysis indicated a positive relationship between SOX10 expression and effector immune cells. SOX10 was identified as a potential immunotherapeutic target. Juxtaposed with non-basal-like breast cancer (N-BLBC) and breast adenosis, immunohistochemical analysis revealed the upregulated expression of SOX10 in BLBC, indicating its potential diagnostic significance. Single-gene functional enrichment analysis indicated that SOX10 is associated with EMT and the tumor inflammatory index. Experimental outcomes from cellular assays suggested that the downregulation of SOX10 inhibited multiple malignancy-associated behaviors in MDA-MB-231 cells, specifically affecting the EMT process, migration, invasion, proliferation, clone formation, and anti-apoptotic activities.

Conclusions

We concluded that SOX10 contributes to the malignancy of BLBC cells by modulating the EMT pathway. Moreover, we observed a notable correlation between SOX10 expression and immune responses, indicating the potential significance of SOX10 in immunotherapy.

Transcriptomic Heterogeneity of Skin Across Different Anatomic Sites

Multiomic studies, including RNA sequencing, single-cell RNA sequencing, and epigenomics, can provide insight into the connection between anatomically heterogeneous gene expression profile of the skin and dermatoses-predisposed sites, in which RNA sequencing is essential. Therefore, in this study, 159 skin samples collected mainly from discarded normal skin tissue during surgical treatment for benign skin tumors were used for RNA sequencing. On the basis of cluster analysis, the skin was divided into four regions, with each region showing specific physiological characteristics through differentially expressed gene analysis. The results showed that the head and neck region, perineum, and palmoplantar area were closely associated with lipid metabolism, hormone metabolism, blood circulation, and related neural regulation, respectively. Transcription factor enrichment indicated that different regions were associated with the development of adjacent tissues. Specifically, the head and neck region, trunk and extremities, perineum, and palmoplantar area were associated with the central nervous, axial, urogenital, and vascular systems, respectively. The results were imported into an open website (https://dermvis.github.io/) for retrieval. Our transcriptomic data elucidated that human skin exhibits transcriptomic heterogeneity reflecting physiological and developmental variation at different anatomic sites and provided guidance for further studies on skin development and dermatoses predisposed sites.

MiR-937-3p promotes metastasis and angiogenesis and is activated by MYC in lung adenocarcinoma

Background

Non-small cell lung cancer (NSCLC) is still one of the diseases with the highest mortality and morbidity, and lung adenocarcinoma (LUAD) accounts for more than half of all NSCLC cases in most countries. miRNA can be used as a potential biological marker and treatment for lung adenocarcinoma. However, the effect of miR-937-3p to the invasion and metastasis of LUAD cells is not clear.

Methods

miRNA microarray is used to analyze the expression of miRNA in lung adenocarcinoma tissue. Transwell migration, Wound-healing assay and Western blot analysis are used to analyze cell migration, invasion and epithelial-mesenchymal transition (EMT) capabilities. Tube formation is used to assess angiogenesis ability. In addition, dual luciferase reporter gene detection is used to identify the potential binding between miRNA and target mRNA. In vivo experiments were performed on male NOD/SCID nude mice by tail vein injection to establish a transplanted tumor model. The CHIP experiment is used to verify the transcription factors of miRNA.

Result

In our study, miR-937-3p was high-regulated in LUAD cell lines and tissues, and its expression level was related to tumor progression. We found that miR-937-3p high-expression has an effect on cell invasion and metastasis. In molecular mechanism, miR-937-3p causes SOX11 reduction by directly binding to the 3′-UTR of SOX11.In addition, MYC affects miR-937-3p transcription by binding to its promoter region.

Conclusions

Our research shows that miR-937-3p is mediated by MYC and can control the angiogenesis, invasion and metastasis of LUAD by regulating SOX11, thereby promoting the progress of LUAD. We speculate that miR-937-3p can be used as a therapeutic target and potential biomarker for LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02453-w.

Histone deacetylase 8 inhibition suppresses mantle cell lymphoma viability while preserving natural killer cell function

Mantle Cell Lymphoma (MCL) is a non-Hodgkin lymphoma with a median survival rate of five years. Standard treatment with high-dose chemotherapy plus rituximab (anti-CD20 antibody) has extended overall survival although, the disease remains incurable. Histone deacetylases (HDAC) are a family of enzymes that regulate multiple proteins and cellular pathways through post-translational modification. Broad spectrum HDAC inhibitors have shown some therapeutic promise, inducing cell cycle inhibition and apoptosis in leukemia and non-Hodgkin's lymphoma. However, the therapeutic effects of these broad-spectrum HDAC inhibitors can detrimentally dampen Natural Killer (NK) cell cytotoxicity, reduce NK viability, and downregulate activation receptors important for NK mediated anti-tumor responses. Impairment of NK function in MCL patients during therapy potentially limits therapeutic activity of rituximab. Thus, there is an unmet need to decipher specific roles of individual HDACs in order to preserve and/or enhance NK function, while, directly impairing MCL viability. We investigated the impact of HDAC8 in MCL cell lines. Inhibition or genetic loss of HDAC8 caused MCL cells to undergo apoptosis. In contrast, exposure of primary human NK cells to an HDAC8 inhibitor does not alter viability, receptor expression, or antibody dependent cellular cytotoxicity (ADCC). However, an increase in effector cytokine interferon-gamma (IFNγ) producing NK cells was observed in response to HDAC8 inhibition. Taken together these data suggest that selective HDAC8 inhibitors may simultaneously preserve NK functional activity, while impairing MCL tumor growth, establishing a rationale for future clinical evaluation.

Cancer and SOX proteins: New insight into their role in ovarian cancer progression/inhibition

Transcription factors are potential targets in disease therapy, particularly in cancer. This is due to the fact that transcription factors regulate a variety of cellular events, and their modulation has opened a new window in cancer therapy. Sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are potential transcription factors that are involved in developmental processes such as embryogenesis. It has been reported that abnormal expression of SOX proteins is associated with development of different cancers, particularly ovarian cancer (OC). In the present review, our aim is to provide a mechanistic review of involvement of SOX members in OC. SOX members may suppress and/or promote aggressiveness and proliferation of OC cells. Clinical studies have also confirmed the potential of transcription factors as diagnostic and prognostic factors in OC. Notably, studies have demonstrated the relationship between SOX members and other molecular pathways such as ST6Ga1-I, PI3K, ERK and so on, leading to more complexity. Furthermore, SOX members can be affected by upstream mediators such as microRNAs, long non-coding RNAs, and so on. It is worth mentioning that the expression of each member of SOX proteins is corelated with different stages of OC. Furthermore, their expression determines the response of OC cells to chemotherapy. These topics are discussed in this review to shed some light on role of SOX transcription factors in OC.

SOX11 inhibits tumor proliferation and promotes cell adhesion mediated-drug resistance via a CD43 dependent manner in mantle cell lymphoma

SOX11 is a critical biomarker for mantle cell lymphoma (MCL) diagnosis; however, its role remains unclear in MCL. Here, clinical-pathological analysis showed Ki67 index was negatively relevant to SOX11 expression only in CD43 positive cases. Coexpression of SOX11/CD43 indicated longer overall survival. In vitro, knockout/overexpression of SOX11 or CD43 promoted/inhibited cell proliferation respectively. CD43 overexpression reversed tumor proliferation induced by SOX11 knockdown. Furthermore, overexpressing/silencing the SOX11/CD43 gene affects phosphorylation of p38-MAPK while p38 inhibitor reversed proliferation induced by si-SOX11 or si-CD43, respectively. In CAM-DR model, both SOX11 and CD43 in MCL cells were elevated when co-cultured with M2-10B4 bone marrow fibroblasts or fibronectin. Knockdown/overexpression of SOX11 decreased/increased cell adhesion, respectively, and the effect induced by silencing SOX11 was reversed by overexpression of CD43. Collectively, SOX11 could inhibit tumor proliferation and promote CAM-DR in a CD43 dependent manner.

Genome-wide DNA methylation profile of early-onset endometrial cancer: its correlation with genetic aberrations and comparison with late-onset endometrial cancer

The present study was performed to clarify the significance of DNA methylation alterations during endometrial carcinogenesis. Genome-wide DNA methylation analysis and targeted sequencing of tumor-related genes were performed using the Infinium MethylationEPIC BeadChip and the Ion AmpliSeq Cancer Hotspot Panel v2, respectively, for 31 samples of normal control endometrial tissue from patients without endometrial cancer and 81 samples of endometrial cancer tissue. Principal component analysis revealed that tumor samples had a DNA methylation profile distinct from that of control samples. Gene Ontology enrichment analysis revealed significant differences of DNA methylation at 1034 CpG sites between early-onset endometrioid endometrial cancer (EE) tissue (patients aged ≤40 years) and late-onset endometrioid endometrial cancer (LE) tissue, which were accumulated among 'transcriptional factors'. Mutations of the CTNNB1 gene or DNA methylation alterations of genes participating in Wnt signaling were frequent in EEs, whereas genetic and epigenetic alterations of fibroblast growth factor signaling genes were observed in LEs. Unsupervised hierarchical clustering grouped EE samples in Cluster EA (n = 22) and samples in Cluster EB (n = 12). Clinicopathologically less aggressive tumors tended to be accumulated in Cluster EB, and DNA methylation levels of 18 genes including HOXA9, HOXD10 and SOX11 were associated with differences in such aggressiveness between the two clusters. We identified 11 marker CpG sites that discriminated EB samples from EA samples with 100% sensitivity and specificity. These data indicate that genetically and epigenetically different pathways may participate in the development of EEs and LEs, and that DNA methylation profiling may help predict tumors that are less aggressive and amenable to fertility preservation treatment.

Clinicopathological features and prognostic value of SOX11 in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia is marked by aberrant transcriptional features that alter cell differentiation, self-renewal, and proliferative features. We sought to identify the transcription factors exhibiting altered and subtype-specific expression patterns in B-ALL and report here that SOX11, a developmental and neuronal transcription factor, is aberrantly expressed in the ETV6-RUNX1 and TCF3-PBX1 subtypes of acute B-cell leukemias. We show that a high expression of SOX11 leads to alterations of gene expression that are typically associated with cell adhesion, migration, and differentiation. A high expression is associated with DNA hypomethylation at the SOX11 locus and a favorable outcome. The results indicate that SOX11 expression marks a group of patients with good outcomes and thereby prompts further study of its use as a biomarker.

SOX11: friend or foe in tumor prevention and carcinogenesis?

Sex-determining region Y-related high-mobility-group box transcription factor 11 (SOX11) is an essential member of the SOX transcription factors and has been highlighted as an important regulator in embryogenesis. SOX11 studies have only recently shifted focus from its role in embryogenesis and development to its function in disease. In particular, the role of SOX11 in carcinogenesis has become of major interest in the field. SOX11 expression is elevated in a wide variety of tumors. In many cancers, dysfunctional expression of SOX11 has been correlated with increased cancer cell survival, inhibited cell differentiation, and tumor progression through the induction of metastasis and angiogenesis. Nevertheless, in a limited number of malignancies, SOX11 has also been identified to function as a tumor suppressor. Herein, we review the correlation between the expression of SOX11 and tumor behaviors. We also summarize the mechanisms underlying the regulation of SOX11 expression and activity in pathological conditions. In particular, we focus on the pathological processes of cancer targeted by SOX11 and discuss whether SOX11 is protective or detrimental during tumor progression. Moreover, SOX11 is highlighted as a clinical biomarker for the diagnosis and prognosis of various human cancer. The information reviewed here should assist in future experimental designs and emphasize the potential of SOX11 as a therapeutic target for cancer.

SOX11, a key oncogenic factor in mantle cell lymphoma

PURPOSE OF REVIEW

SOX11 has emerged as a key transcription factor in the pathogenesis of mantle cell lymphoma (MCL) whereas it is not expressed in normal B cells or virtually in any other mature B-cell neoplasm. This review will examine the role of SOX11 as a biomarker in MCL, the new information on its transcriptional targets, and the mechanisms regulating its expression in MCL.

RECENT FINDINGS

SOX11 is highly expressed in conventional MCL, including cyclin D1-negative cases, but it is not expressed in the indolent leukemic nonnodal MCL subtype. These two MCL subtypes also differ in their cell-of-origin, IGHV mutational status and genomic instability. SOX11 promotes tumor growth of MCL cells in vivo and regulates a broad transcriptional program that includes B-cell differentiation pathways and tumor-microenvironment interactions, among others. The mechanisms upregulating SOX11 in MCL are not well understood but are mediated in part by the three-dimensional reconfiguration of the DNA, bringing together a distant enhancer region and the SOX11 promoter.

SUMMARY

SOX11 is a relevant element in the pathogenesis of MCL and has been instrumental to identify two distinct clinicobiological subtypes of this tumor. Further studies should clarify the mechanisms mediating its oncogenic potential and leading to its intriguing expression in these tumors.

Regulation of SOX11 expression through CCND1 and STAT3 in mantle cell lymphoma

The neural transcription factor SOX11 is usually highly expressed in typical mantle cell lymphoma (MCL), but it is absent in the more indolent form of MCL. Despite being an important diagnostic marker for this hard-to-treat malignancy, the mechanisms of aberrant SOX11 expression are largely unknown. Herein, we describe 2 modes of SOX11 regulation by the cell-cycle regulator cyclin D1 (CCND1) and the signal transducer and activator of transcription 3 (STAT3). We found that ectopic expression of CCND1 in multiple human MCL cell lines resulted in increased SOX11 transcription, which correlated with increased acetylated histones H3K9 and H3K14 (H3K9/14Ac). Increased H3K9/14Ac and SOX11 expression was also observed after histone deacetylase 1 (HDAC1) or HDAC2 was depleted by RNA interference or inhibited by the HDAC inhibitor vorinostat. Mechanistically, we showed that CCND1 interacted with and sequestered HDAC1 and HDAC2 from the SOX11 locus, leading to SOX11 upregulation. Interestingly, our data revealed a potential inverse relationship between phosphorylated Y705 STAT3 and SOX11 expression in MCL cell lines, primary tumors, and patient-derived xenografts. Functionally, inactivation of STAT3 by inhibiting the upstream Janus kinase (JAK) 1 or JAK2 or by STAT3 knockdown was found to increase SOX11 expression, whereas interleukin-21 (IL-21)-induced STAT3 activation or overexpression of the constitutively active form of STAT3 decreased SOX11 expression. In addition, targeting SOX11 directly by RNA interference or indirectly by IL-21 treatment induced toxicity in SOX11⁺ MCL cells. Collectively, we demonstrate the involvement of CCND1 and STAT3 in the regulation of SOX11 expression, providing new insights and therapeutic implications in MCL.

Whole-exome sequencing capture kit biases yield false negative mutation calls in TCGA cohorts

The Cancer Genome Atlas (TCGA) provides a genetic characterization of more than ten thousand tumors, enabling the discovery of novel driver mutations, molecular subtypes, and enticing drug targets across many histologies. Here we investigated why some mutations are common in particular cancer types but absent in others. As an example, we observed that the gene CCDC168 has no mutations in the stomach adenocarcinoma (STAD) cohort despite its common presence in other tumor types. Surprisingly, we found that the lack of called mutations was due to a systematic insufficiency in the number of sequencing reads in the STAD and other cohorts, as opposed to differential driver biology. Using strict filtering criteria, we found similar behavior in four other genes across TCGA cohorts, with each gene exhibiting systematic sequencing depth issues affecting the ability to call mutations. We identified the culprit as the choice of exome capture kit, as kit choice was highly associated with the set of genes that have insufficient reads to call a mutation. Overall, we found that thousands of samples across all cohorts are subject to some capture kit problems. For example, for the 6353 samples using the Broad Institute’s Custom capture kit there are undercalling biases for at least 4833 genes. False negative mutation calls at these genes may obscure biological similarities between tumor types and other important cancer driver effects in TCGA datasets.

Aberrant methylation of FAT4 and SOX11 in peripheral blood leukocytes and their association with gastric cancer risk

Background: Aberrant DNA methylation, especially tumor suppressor gene hypermethylation, is a well-recognized biomarker of initial tumorogenesis stages. FAT4 and SOX11 are putative tumor suppressor genes and can be down-regulated by hypermethylation in various cancers tissues. However, in peripheral blood leukocytes, the association between these two genes methylation status, as well as the effects of gene-environment interactions, and gastric cancer (GC) risk remain unclear.

Methods: A hospital-based case-control study including 375 cases and 394 controls was conducted. Peripheral blood leukocytes DNA methylation status were detected by methylation-sensitive high-resolution melting (MS-HRM) assay. Logistic regression was adopted to analyze the relationship of FAT4 and SOX11 methylation with GC susceptibility.

Results: Positive methylation (Pm) and total positive methylation (Tpm) of FAT4 were significantly increased the risk of GC (OR = 2.204, 95% CI: 1.168-4.159, P = 0.015; OR = 1.583, 95% CI: 1.031-2.430, P = 0.036, respectively). Compared with controls, cases exhibited higher SOX11 Pm frequencies with OR of 2.530 (95% CI: 1.289-4.969, P = 0.007). Nonetheless, no statistically significant association between SOX11 Tpm and GC risk was observed. Additionally, interactions between FAT4 Tpm and increased consumption of freshwater fish (≥1 times/week) displayed an antagonistic effect on GC (OR = 0.328, 95% CI: 0.142-0.762, P = 0.009), and high salt intake interacted with SOX11 Tpm also showed statistically significant (OR = 0.490, 95% CI: 0.242-0.995, P = 0.048).

Conclusions:FAT4 aberrant methylation in peripheral blood leukocytes and gene-environment interactions were associated with the risk of GC, while SOX11 was controversial and needed to be more investigated.

Promoter hypermethylation of SOX11 correlates with adverse clinicopathological features of human prostate cancer

Currently available tools for early diagnosis and prognosis of prostate cancer lack sufficient accuracy. There is a need to identify novel biomarkers for this common malignancy. SOX family genes play an important role in embryogenesis and are also implicated in various cancers. SOX11 has been recently recognized as a potential tumour suppressor that is downregulated in prostate cancer. We hypothesized that hypermethylation may be responsible for SOX11 silencing in human prostate cancer. The aim of the study was to investigate SOX11 promoter methylation in prostate adenocarcinoma by comparing it with benign prostatic hyperplasia (BPH). A total of 143 human prostate tissue samples, 62 from patients with prostate cancer and 81 from patients with BPH were examined by methylation-specific PCR. Associations between SOX11 promoter methylation and clinicopathological parameters were assessed by univariate statistics. Detection rates of SOX11 promoter methylation were 80.6% and 35.8% in prostate cancer and BPH respectively (P < 0.001). SOX11 hypermethylation was associated with adverse clinicopathological characteristics of prostate cancer, including higher PSA level (P < 0.01), Gleason score ≥ 7 (P = 0.03) and perineural invasion (P = 0.03). SOX11 methylation was positively correlated with the PSA level (P = 0.001). Our data indicated that SOX11 can be a promising methylation marker candidate for differential diagnosis and risk stratification for prostate cancer.

The SOX11 transcription factor is a critical regulator of basal-like breast cancer growth, invasion, and basal-like gene expression

Basal-like breast cancers (BLBCs) are aggressive breast cancers associated with poor survival. Defining the key drivers of BLBC growth will allow identification of molecules for targeted therapy. In this study, we performed a primary screen integrating multiple assays that compare transcription factor expression and activity in BLBC and non-BLBC at the RNA, DNA, and protein levels. This integrated screen identified 33 transcription factors that were elevated in BLBC in multiple assays comparing mRNA expression, DNA cis-element sequences, or protein DNA-binding activity. In a secondary screen to identify transcription factors critical for BLBC cell growth, 8 of the 33 candidate transcription factors (TFs) were found to be necessary for growth in at least two of three BLBC cell lines. Of these 8 transcription factors, SOX11 was the only transcription factor required for BLBC growth, but not for growth of non-BLBC cells. Our studies demonstrate that SOX11 is a critical regulator of multiple BLBC phenotypes, including growth, migration, invasion, and expression of signature BLBC genes. High SOX11 expression was also found to be an independent prognostic indicator of poor survival in women with breast cancer. These results identify SOX11 as a potential target for the treatment of BLBC, the most aggressive form of breast cancer.

miR-223 is repressed and correlates with inferior clinical features in mantle cell lymphoma through targeting SOX11

Mantle cell lymphoma (MCL) is an aggressive lymphoid malignancy characterized by cytogenetic aberration of t(11;14), although it is not the prerequisite. Until now, the pathogenesis of MCL has not been fully interpreted. Our current study showed that microRNA (miR)-223 was downregulated in purified CD19⁺ lymphocytes from MCL patients (n = 21) compared with that of healthy donors (n = 20). In addition, patients with a high-risk Mantle Cell Lymphoma International Prognostic Index (MIPI) score, elevated lactate dehydrogenase, and Eastern Cooperative Oncology Group performance status >2 were more likely to have much lower miR-223 expression. Furthermore, low miR-223 expression predicted inferior overall survival regardless of treatment in our cohort of 21. To explore the role of miR-223 in MCL, we constructed an ectopic miR-223 MCL cell line and revealed that miR-223 inhibited cell proliferation and promoted G₀/G₁ accumulation and cell apoptosis. A database search showed that SOX11, a crucial transcription factor in MCL, is the putative target of miR-223. In support of this, we observed a much lower level of SOX11 protein in miR-223-overexpressing cells than in parental cells. Further, the luciferase reporter assay confirmed that miR-223 at the posttranscriptional level suppressed the wild-type 3'-untranslated region of SOX11 but not the mutated one. Finally, miR-223 was found to be negatively correlated with the mRNA level of SOX11 in clinical samples. Our work demonstrates for the first time that miR-223 is repressed and correlated with high-risk clinical features in MCL, which provides a potential molecule to target to optimize MCL management.

SOX10 induces epithelial-mesenchymal transition and contributes to nasopharyngeal carcinoma progression

OBJECTIVE

The aim of this study was to investigate the role of SOX10 in nasopharyngeal carcinoma (NPC) and the underlying molecular mechanisms.

METHODS

The expression of SOX10 was initially assessed in human NPC tissues and a series of NPC cell lines through quantitative real-time PCR (qRT-PCR) and Western blot. Then, cell proliferation, cycle, migration, and the invasiveness of NPC cells with knockdown of SOX10 were examined by MTT, flow cytometry, and Transwell migration and invasion assays, respectively. Finally, nude mice tumorigenicity experiments were performed to evaluate the effects of SOX10 on NPC growth and metastasis in vivo.

RESULTS

SOX10 was significantly increased in NPC tissues and cell lines. In-vitro experiments revealed that loss of SOX10 obviously inhibited cell proliferation, migration, and invasiveness, as well as the epithelial-mesenchymal transition (EMT) process in NPC cells. In-vivo experiments further demonstrated that disrupted SOX10 expression restrained NPC growth and metastasis, especially in lung and liver.

CONCLUSION

Taken together, our data confirmed the role of SOX10 as an oncogene in NPC progression, and revealed that SOX10 may serve as a novel biomarker for diagnosis of NPC, as well as a potential therapeutic target against this disease.

Galectin-9: From cell biology to complex disease dynamics

Galectins is a family of non-classically secreted, beta-galactoside-binding proteins that has recently received considerable attention in the spatio-temporal regulation of surface 'signal lattice' organization, membrane dynamics, cell-adhesion and disease therapeutics. Galectin-9 is a unique member of this family, with two non-homologous carbohydrate recognition domains joined by a linker peptide sequence of variable lengths, generating isoforms with distinct properties and functions in both physiological and pathological settings, such as during development, immune reaction, neoplastic transformations and metastasis. In this review, we summarize the latest knowledge on the structure, receptors, cellular targets, trafficking pathways and functional properties of galectin-9 and discuss how galectin-9-mediated signalling cascades can be exploited in cancers and immunotherapies.

Identification of V-ATPase as a molecular sensor of SOX11-levels and potential therapeutic target for mantle cell lymphoma

Background

Mantle cell lymphoma (MCL) is an aggressive disease with short median survival. Molecularly, MCL is defined by the t(11;14) translocation leading to overexpression of the CCND1 gene. However, recent data show that the neural transcription factor SOX11 is a disease defining antigen and several involved signaling pathways have been pin-pointed, among others the Wnt/β-catenin pathway that is of importance for proliferation in MCL. Therefore, we evaluated a compound library focused on the Wnt pathway with the aim of identifying Wnt-related targets that regulate growth and survival in MCL, with particular focus on SOX11-dependent growth regulation.

Methods

An inducible SOX11 knock-down system was used to functionally screen a library of compounds (n = 75) targeting the Wnt signaling pathway. A functionally interesting target, vacuolar-type H⁺-ATPase (V-ATPase), was further evaluated by western blot, siRNA-mediated gene silencing, immunofluorescence, and flow cytometry.

Results

We show that 15 out of 75 compounds targeting the Wnt pathway reduce proliferation in all three MCL cell lines tested. Furthermore, three substances targeting two different targets (V-ATPase and Dkk1) showed SOX11-dependent activity. Further validation analyses were focused on V-ATPase and showed that two independent V-ATPase inhibitors (bafilomycin A1 and concanamycin A) are sensitive to SOX11 levels, causing reduced anti-proliferative response in SOX11 low cells. We further show, using fluorescence imaging and flow cytometry, that V-ATPase is mainly localized to the plasma membrane in primary and MCL cell lines.

Conclusions

We show that SOX11 status affect V-ATPase dependent pathways, and thus may be involved in regulating pH in intracellular and extracellular compartments. The plasma membrane localization of V-ATPase indicates that pH regulation of the immediate extracellular compartment may be of importance for receptor functionality and potentially invasiveness in vivo.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2550-4) contains supplementary material, which is available to authorized users.

SOXC and MiR17-92 gene expression profiling defines two subgroups with different clinical outcome in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a heterogeneous B-cell lymphoid malignancy where most patients follow an aggressive clinical course whereas others are associated with an indolent performance. SOX4, SOX11, and SOX12 belong to SOXC family of transcription factors involved in embryonic neurogenesis and tissue remodeling. Among them, SOX11 has been found aberrantly expressed in most aggressive MCL patients, being considered a reliable biomarker in the pathology. Several studies have revealed that microRNAs (miRs) from the miR-17-92 cluster are among the most deregulated miRNAs in human cancers, still little is known about this cluster in MCL. In this study we screened the transcriptional profiles of 70 MCL patients for SOXC cluster and miR17, miR18a, miR19b and miR92a, from the miR-17-92 cluster. Gene expression analysis showed higher SOX11 and SOX12 levels compared to SOX4 (P ≤ 0.0026). Moreover we found a negative correlation between the expression of SOX11 and SOX4 (P < 0.0001). miR17-92 cluster analysis showed that miR19b and miR92a exhibited higher levels than miR17 and miR18a (P < 0.0001). Unsupervised hierarchical clustering revealed two subgroups with significant differences in relation to aggressive MCL features, such as blastoid morphological variant (P = 0.0412), nodal presentation (P = 0.0492), CD5(+) (P = 0.0004) and shorter overall survival (P < 0.0001). Together, our findings show for the first time an association between the differential expression profiles of SOXC and miR17-92 clusters in MCL and also relate them to different clinical subtypes of the disease adding new biological information that may contribute to a better understanding of this pathology. © 2016 Wiley Periodicals, Inc.

The transcriptional coregulator MAML1 affects DNA methylation and gene expression patterns in human embryonic kidney cells

Mastermind-like 1 (MAML1) is a transcriptional coregulator that has been associated with early development of many systems such as neuronal, muscular and urogenital. The present study aimed to explore the genome wide effects of MAML1 on DNA methylation and RNA expression in human embryonic kidney cells. Infinium HumanMethylation450 BeadChip Illumina array, methylation-sensitive high-resolution melt technique, Chip Analysis Methylation Pipeline and RNA profiling approaches were used to study MAML1 effects on the epigenome. We found that 11802 CpG sites were differentially methylated in MAML1-expressing cells while only 225 genes were differentially expressed. MAML1 overexpression induced more global differential hypermethylation than hypomethylation changes. In addition, the differentially methylated regions were mapped predominantly to 3'untranslated regions, intragenic regions and gene bodies and to a lesser extent to gene regulatory sequences. Gene ontology analysis revealed that the differentially changed genes (including HOXC11, HTATIP2, SLFN12 and SOX11) are involved in the regulation of urogenital system development, cell adhesion and embryogenesis. This study is the first report that shows the global effect of a single coregulator on DNA methylation and gene expression. Our results stress and support the effects of transcriptional coregulators on the cell methylome.

SOX10, a novel HMG-box-containing tumor suppressor, inhibits growth and metastasis of digestive cancers by suppressing the Wnt/β-catenin pathway

SOX10 was identified as a methylated gene in our previous cancer methylome study. Here we further analyzed its epigenetic inactivation, biological functions and related cell signaling in digestive cancers (colorectal, gastric and esophageal cancers) in detail. SOX10 expression was decreased in multiple digestive cancer cell lines as well as primary tumors due to its promoter methylation. Pharmacologic or genetic demethylation reversed SOX10 silencing. Ectopic expression of SOX10in SOX10-deficient cancer cells inhibits their proliferation, tumorigenicity, and metastatic potentials in vitro and in vivo. SOX10 also suppressed the epithelial to mesenchymal transition (EMT) and stemness properties of digestive tumor cells. Mechanistically, SOX10 competes with TCF4 to bind β-catenin and transrepresses its downstream target genes via its own DNA-binding property. SOX10 mutations that disrupt the SOX10-β-catenin interaction partially prevented tumor suppression. SOX10is thus a commonly inactivated tumor suppressor that antagonizes Wnt/β-catenin signaling in cancer cells from different digestive tissues.

Chromatin remodelers HELLS and UHRF1 mediate the epigenetic deregulation of genes that drive retinoblastoma tumor progression

The retinoblastoma (Rb) family of proteins are key regulators of cell cycle exit during development and their deregulation is associated with cancer. Rb is critical for normal retinal development and germline mutations lead to retinoblastoma making retinae an attractive system to study Rb family signaling. Rb coordinates proliferation and differentiation through the E2f family of transcription factors, a critical interaction for the role of Rb in retinal development and tumorigenesis. However, whether the roles of the different E2fs are interchangeable in controlling development and tumorigenesis in the retina or if they have selective functions remains unknown. In this study, we found that E2f family members play distinct roles in the development and tumorigenesis. In Rb;p107-deficient retinae, E2f1 and E2f3 inactivation rescued tumor formation but only E2f1 rescued the retinal development phenotype. This allowed the identification of key target genes for Rb/E2f family signaling contributing to tumorigenesis and those contributing to developmental defects. We found that Sox4 and Sox11 genes contribute to the developmental phenotype and Hells and Uhrf1 contribute to tumorigenesis. Using orthotopic human xenografts, we validated that upregulation of HELLS and UHRF1 is essential for the tumor phenotype. Also, these epigenetic regulators are important for the regulation of SYK.

DNA methylation and histone modifications regulate SOX11 expression in lymphoid and solid cancer cells

Background

The neural transcription factor SOX11 is present at specific stages during embryo development with a very restricted expression in adult tissue, indicating precise regulation of transcription. SOX11 is strongly up-regulated in some malignancies and have a functional role in tumorgenesis. With the aim to explore differences in epigenetic regulation of SOX11 expression in normal versus neoplastic cells, we investigated methylation and histone modifications related to the SOX11 promoter and the possibility to induce re-expression using histone deacetylase (HDAC) or EZH2 inhibitors.

Methods

The epigenetic regulation of SOX11 was investigated in distinct non-malignant cell populations (n = 7) and neoplastic cell-lines (n = 42) of different cellular origins. DNA methylation was assessed using bisulfite sequencing, methylation-specific melting curve analysis, MethyLight and pyrosequencing. The presence of H3K27me3 was assessed using ChIP-qPCR. The HDAC inhibitors Vorinostat and trichostatin A were used to induce SOX11 in cell lines with no endogenous expression.

Results

The SOX11 promoter shows a low degree of methylation and strong enrichment of H3K27me3 in non-malignant differentiated cells, independent of cellular origin. Cancers of the B-cell lineage are strongly marked by de novo methylation at the SOX11 promoter in SOX11 non-expressing cells, while solid cancer entities display a more varying degree of SOX11 promoter methylation. The silencing mark H3K27me3 was generally present at the SOX11 promoter in non-expressing cells, and an increased enrichment was observed in cancer cells with a low degree of SOX11 methylation compared to cells with dense methylation. Finally, we demonstrate that the HDAC inhibitors (vorinostat and trichostatin A) induce SOX11 expression in cancer cells with low levels of SOX11 methylation.

Conclusions

We show that SOX11 is strongly marked by repressive histone marks in non-malignant cells. In contrast, SOX11 regulation in neoplastic tissues is more complex involving both DNA methylation and histone modifications. The possibility to re-express SOX11 in non-methylated tissue is of clinical relevance, and was successfully achieved in cell lines with low levels of SOX11 methylation. In breast cancer patients, methylation of the SOX11 promoter was shown to correlate with estrogen receptor status, suggesting that SOX11 may be functionally re-expressed during treatment with HDAC inhibitors in specific patient subgroups.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1208-y) contains supplementary material, which is available to authorized users.

Aberrant SOX11 promoter methylation is associated with poor prognosis in gastric cancer

BACKGROUND

Gastric cancer (GC) is the second most common cause of cancer mortality world-wide. In recent years, aberrant SOX11 expression has been observed in various solid and hematopoietic malignancies, including GC. In addition, it has been reported that SOX11 expression may serve as an independent prognostic factor for the survival of GC patients. Here, we assessed the SOX11 gene promoter methylation status in various GC cell lines and primary GC tissues, and evaluated its clinical significance.

METHODS

Five GC cell lines were used to assess SOX11 expression by qRT-PCR. The effect of SOX11 expression restoration after 5-aza-2'-deoxycytidine (5-Aza-dC) treatment on GC growth was evaluated in GC cell line MKN45. Subsequently, 89 paired GC-normal gastric tissues were evaluated for their SOX11 gene promoter methylation status using methylation-specific PCR (MSP), and 20 paired GC-normal gastric tissues were evaluated for their SOX11 expression in relation to SOX11 gene promoter methylation. GC patient survival was assessed by Kaplan-Meier analyses and a Cox proportional hazard model was employed for multivariate analyses.

RESULTS

Down-regulation of SOX11 mRNA expression was observed in both GC cell lines and primary GC tissues. MSP revealed hyper-methylation of the SOX11 gene promoter in 55.1% (49/89) of the primary GC tissues tested and in 7.9% (7/89) of its corresponding non-malignant tissues. The SOX11 gene promoter methylation status was found to be related to the depth of GC tumor invasion, Borrmann classification and GC differentiation status. Upon 5-Aza-dC treatment, SOX11 expression was found to be up-regulated in MKN45 cells, in conjunction with proliferation inhibition. SOX11 gene promoter hyper-methylation was found to be significantly associated with a poor prognosis and to serve as an independent marker for survival using multivariate Cox regression analysis.

CONCLUSIONS

Our results indicate that aberrant SOX11 gene promoter methylation may underlie its down-regulation in GC. SOX11 gene promoter hyper-methylation may serve as a biomarker to predict the clinical outcome of GC.

The role of tumor suppressor gene SOX11 in prostate cancer

SOX genes play an important role in a number of developmental processes. The transcription factor SOX11 is one of the members of the SOX family emerging as important transcriptional regulators. The aim of this study was to investigate the role of SOX11 in prostate cancer (PCa) and its expression pattern and clinical significance. The gene expression of SOX11 in human PCa tissues compared with benign prostate hyperplasia (BPH) tissues was detected using real-time quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) analysis and immunohositochemistry. SOX11 overexpression cell model was used to examine the role of SOX11 in cell growth and metastasis in vitro. The results showed that the positive rate of SOX11 staining was 16.67 % (10/60) in cases of prostatic carcinoma and 81.67 % (49/60) in cases of BPH, and the difference of SOX11 expression between PCa and BPH was statistically significant (P < 0.001). SOX11 mRNA level was lowly expressed in PCa cell lines compared to RWPE-1. SOX11 overexpression suppresses PCa cell migration and invasion. In conclusion, our findings demonstrate that SOX11 could suppress cell proliferation, migration, and invasion of PCa in vitro.

SOX11 and TP53 add prognostic information to MIPI in a homogenously treated cohort of mantle cell lymphoma--a Nordic Lymphoma Group study

Mantle cell lymphoma (MCL) is an aggressive B cell lymphoma, where survival has been remarkably improved by use of protocols including high dose cytarabine, rituximab and autologous stem cell transplantation, such as the Nordic MCL2/3 protocols. In 2008, a MCL international prognostic index (MIPI) was created to enable stratification of the clinical diverse MCL patients into three risk groups. So far, use of the MIPI in clinical routine has been limited, as it has been shown that it inadequately separates low and intermediate risk group patients. To improve outcome and minimize treatment-related morbidity, additional parameters need to be evaluated to enable risk-adapted treatment selection. We have investigated the individual prognostic role of the MIPI and molecular markers including SOX11, TP53 (p53), MKI67 (Ki-67) and CCND1 (cyclin D1). Furthermore, we explored the possibility of creating an improved prognostic tool by combining the MIPI with information on molecular markers. SOX11 was shown to significantly add prognostic information to the MIPI, but in multivariate analysis TP53 was the only significant independent molecular marker. Based on these findings, we propose that TP53 and SOX11 should routinely be assessed and that a combined TP53/MIPI score may be used to guide treatment decisions.

The metastasis suppressor SOX11 is an independent prognostic factor for improved survival in gastric cancer

SOX11 is involved in gastrulation and in malignant diseases. The aim of this study was to investigate the role of SOX11 in gastric cancer and its expression pattern and clinical significance. SOX11 overexpression cell model was used to examine in vitro and in vivo the role of SOX11 in cell growth and metastasis. Cell cycle analysis and Annexin V/PI double staining were used to investigate the effect of SOX11 on cell cycle progression and apoptosis. The expression of SOX11 in human gastric cancer was examined by immunohistochemistry. The correlation of SOX11 expression with clinicopathological characteristics and survival of patients was analyzed by Pearson’s χ² and Kaplan-Meier analyses, respectively. Cox’s proportional hazard model was employed in multivariate analysis. SOX11 overexpression did not inhibit cell growth but strongly suppressed cell migration/invasion in vitro and in vivo. We found a significant correlation between high SOX11 protein levels and Lauren’s classification (intestinal type), differentiation status (high and medium), and early TNM stage. SOX11 is an independent prognostic factor for improved survival in gastric cancer patients. SOX11 was a potential tumor-suppressor and an independent positive prognostic factor in gastric cancer patients with less advanced clinicopathological features.

Promoter methylation status of the tumor suppressor gene SOX11 is associated with cell growth and invasion in nasopharyngeal carcinoma

BACKGROUND

The transcription factor SOX11 is one of members of the SRY box-containing (SOX) family emerging as important transcriptional regulators. In recent years, up-regulation of SOX11 has been detected in various types of solid tumors. In this study, the effects of promoter methylation of the SOX11 gene on SOX11 expression and cell growth and invasion of nasopharyngeal carcinoma were investigated.

METHODS

In this study,methylation-specific PCR and real time quantitative PCR have been applied to investigate the effect of promoter methylation of the SOX11 gene on SOX11 expression in the nasopharyngeal carcinoma and chronic inflammation tissues. The nasopharyngeal carcinoma cell line (CNE2) was treated with 5-aza-2'-deoxycytidine. The effect of promoter methylation of SOX11 on growth and invasion of nasopharyngeal carcinoma cells was detected with MTT test and Boyden chamber Matrigel invasion assay.

RESULTS

No or weak expression of SOX11 mRNA was detected in the nasopharyngeal carcinoma tissues of SOX11 gene promoter methylation. Strong expression of SOX11 mRNA was detected in the nasopharyngeal carcinoma tissues of SOX11 gene promoter unmethylation and chronic inflammation tissues of pharynx nasalis. SOX11 mRNA and protein were re-expressed, SOX11 gene was demethylated, and growth and invasion of cells were inhibited in CNE2 cell line after 5-aza-2'-deoxycytidine treatment.

CONCLUSIONS

The results of the study indicate that expression of SOX11 mRNA and protein were related to SOX11 gene methylation status. SOX11 gene methylation may be plays a role in growth and invasion of nasopharyngeal carcinoma cells.

SOXC transcription factors in mantle cell lymphoma: the role of promoter methylation in SOX11 expression

The related transcription factors SOX11, SOX4 and SOX12 (classified as the SOXC family) compete for the same target genes. SOX11 is expressed in most mantle cell lymphomas (MCL) but a small subset is, like normal lymphocytes, SOX11 negative. Here we report the variable expression of SOX4 and high expression of SOX12 in MCL compared to non-malignant tissue. Our results show that the expression of the SOXC genes is highly correlated in SOX11 positive MCL. SOX11 expression is epigenetically regulated but there are partly conflicting results regarding the underlying mechanisms. Here we report that the SOX11 promoter region is hypomethylated in both MCL and normal B-lymphocytes. Methylation at other sites is important for sustaining high SOX11 in MCL since treatment with 5-azacytidine decreased SOX11 levels in SOX11 positive MCL cell lines: Granta519 and Rec1. Furthermore, 5-azacytidine treatment of the SOX11 negative MCL cell line, JVM2, induced SOX4 but not SOX11.

Nuclear T-STAR protein expression correlates with HER2 status, hormone receptor negativity and prolonged recurrence free survival in primary breast cancer and decreased cancer cell growth in vitro

T-STAR (testis-signal transduction and activation of RNA) is an RNA binding protein, containing an SH3-binding domain and thus potentially playing a role in integration of cell signaling and RNA metabolism. The specific function of T-STAR is unknown and its implication in cancer is poorly characterized. Expression of T-STAR has been reported in human testis, muscle and brain tissues, and is associated with a growth-inhibitory role in immortalized fibroblasts. The aim of this paper was to investigate the functional role of T-STAR through (i) survival analysis of patients with primary invasive breast cancer and (ii) experimental evaluation of the effect of T-STAR on breast cancer cell growth. T-STAR protein expression was analysed by immunohistochemistry (IHC) in tissue microarrays with tumors from 289 patients with primary invasive breast cancer, and correlations to clinicopathological characteristics, recurrence-free and overall survival (RFS and OS) and established tumor markers such as HER2 and ER status were evaluated. In addition, the function of T-STAR was investigated using siRNA-mediated knock-down and overexpression of the gene in six breast cancer cell lines. Of the tumors analysed, 86% showed nuclear T-STAR expression, which was significantly associated with an improved RFS and strongly associated with positive HER2 status and negative hormone receptor status. Furthermore, experimental data showed that overexpression of T-STAR decreased cellular growth while knock-down increased it, as shown both by thymidine incorporation and metabolic activity. In summary, we demonstrate that T-STAR protein expression correlates with an improved RFS in primary breast cancer. This is supported by functional data, indicating that T-STAR regulation is of importance both for breast cancer biology and clinical outcome but future studies are needed to determine a potential role in patient stratification.

Increased expression of sex determining region Y-box 11 (SOX11) in cutaneous malignant melanoma

OBJECTIVES

To observe sex determining region Y-box 11 (SOX11) gene expression in cutaneous malignant melanoma and its effect on tumour cell proliferation.

METHODS

Clinicopathological data and tissue samples from patients with cutaneous malignant melanoma, together with tissue samples from healthy volunteers (controls), were retrospectively reviewed. Protein levels of SOX11 and the antigen identified by monoclonal antibody Ki-67 (Ki-67) in skin lesions were analysed using immunohistochemistry. The correlation between protein levels and clinipathological parameters was investigated.

RESULTS

Out of 40 patient samples, 25 (62.5%) were positive for SOX11 protein in malignant melanoma tissue. This was significantly higher than in 40 control tissue samples, in which no SOX11 protein was detected. Presence of SOX11 protein was positively related to the proliferation index of cutaneous malignant melanoma tumour cells. Presence of SOX11 protein in cutaneous malignant melanoma was related to tumour type, tumour location, lymph node metastasis and 5-year survival rate.

CONCLUSION

Human cutaneous malignant melanoma tissues expressed high levels of SOX11 compared with healthy controls, suggesting that SOX11 may be a new prognostic marker for malignant melanoma.

An ensemble prognostic model for colorectal cancer

Colorectal cancer can be grouped into Dukes A, B, C, and D stages based on its developments. Generally speaking, more advanced patients have poorer prognosis. To integrate progression stage prediction systems with recurrence prediction systems, we proposed an ensemble prognostic model for colorectal cancer. In this model, each patient was assigned a most possible stage and a most possible recurrence status. If a patient was predicted to be recurrence patient in advanced stage, he would be classified into high risk group. The ensemble model considered both progression stages and recurrence status. High risk patients and low risk patients predicted by the ensemble model had a significant different disease free survival (log-rank test p-value, 0.0016) and disease specific survival (log-rank test p-value, 0.0041). The ensemble model can better distinguish the high risk and low risk patients than the stage prediction model and the recurrence prediction model alone. This method could be applied to the studies of other diseases and it could significantly improve the prediction performance by ensembling heterogeneous information.

Sox11 expression in astrocytic gliomas: correlation with nestin/c-Met/IDH1-R132H expression phenotypes, p-Stat-3 and survival

Background:

Sox11 is a transcription factor expressed in foetal and neoplastic brain tissue, including gliomas. It has been shown to suppress the tumourigenicity of glioma stem cells in vivo, thereby being hypothesised to function as a tumour suppressor.

Methods:

We investigated the expression of Sox11 in 132 diffuse astrocytomas in relation to the regulator cell marker nestin, c-Met and IDH1-R132H, which have shown to be differentially expressed among the molecular subgroups of malignant gliomas, as well as to an inducer of astrocytic differentiation, that is, signal transducer and activator of transcription (p-STAT-3), clinicopathological features and survival.

Results:

Sox11 immunoreactivity was identified in all tumours irrespective of grade, but being correlated with p-STAT-3. Three out of seven cases showed partial Sox11 promoter methylation. In >50% of our cases neoplastic cells coexpressed Sox11 and nestin, a finding further confirmed in primary glioblastoma cell cultures. Furthermore, nestin, c-Met and IDH1-R132H expression differed among grade categories. Cluster analysis identified four groups of patients according to c-Met, nestin and IDH1-R132H expression. The c-Met/nestin high-expressor group displayed a higher Sox11 expression. Sox11 expression was an indicator of favourable prognosis in glioblastomas, which remained in multivariate analysis and validated in an independent set of 72 cases. The c-Met/nestin high-expressor group was marginally with shorter survival in univariate analysis.

Conclusions:

We highlight the importance of Sox11 expression as a favourable prognosticator in glioblastomas. c-Met/nestin/IDH1-R132H expression phenotypes recapitulate the molecular subgroups of malignant glioma.

Recent advances in mantle cell lymphoma: report of the 2012 Mantle Cell Lymphoma Consortium Workshop

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma characterized by overexpression of cyclin D1 and the t(11;14)(q13;q32) chromosomal translocation. MCL is biologically and clinically heterogeneous and frequently disseminates to extranodal areas. While a subset of patients have an indolent clinical course, the overall outcome for patients with MCL remains poor. There is no proven curative therapy, and no standard of care has been established for initial or subsequent lines of therapy. Several regimens are highly active in previously untreated patients, and recent research has led to improvements in currently available therapy. Moreover, investigational agents have recently demonstrated promising activity in clinical trials. A workshop was held to review recent data on MCL pathogenesis, novel molecular targets and alternative approaches to immunotherapy, and to discuss recent and ongoing clinical trials in MCL. The presentations are summarized in this article, which is intended to highlight areas of active investigation and identify important avenues for future research.

SOX15 is a candidate tumor suppressor in pancreatic cancer with a potential role in Wnt/β-catenin signaling

Pancreatic cancer is among the top five deadliest cancers in developed countries. Better knowledge of the molecular mechanisms contributing to its tumorigenesis is imperative to improve patient prognosis. Identification of novel tumor suppressor genes (TSGs) in pancreatic cancer will reveal new mechanisms of pathway deregulation and will ultimately help improve our understanding of this aggressive disease. According to Knudson's two-hit model, TSGs are classically disrupted by two concerted genetic events. In this study, we combined DNA methylation profiling with copy number and mRNA expression profiling to identify novel TSGs in a set of 20 pancreatic cancer cell lines. These data sets were integrated for each of ∼12 000 genes in each cell line enabling the elucidation of those genes that undergo DNA hypermethylation, copy-number loss and mRNA downregulation simultaneously in multiple cell lines. Using this integrative genomics strategy, we identified SOX15 (sex determining region Y-box 15) as a candidate TSG in pancreatic cancer. Expression of SOX15 in pancreatic cancer cell lines with undetectable expression resulted in reduced viability of cancer cells both in vitro and in vivo demonstrating its tumor suppressive capability. We also found reduced expression, homozygous deletion and aberrant DNA methylation of SOX15 in clinical pancreatic tumor data sets. Furthermore, we deduced a novel role for SOX15 in suppressing the Wnt/β-catenin signaling pathway, which we hypothesize is a pathway through which SOX15 may exert its tumor suppressive effects in pancreatic cancer.

Expression of Sox4 and Sox11 is regulated by multiple mechanisms during retinal development

Sox11 and Sox4 play critical roles in retinal development, during which they display specific and unique expression patterns. The expression of Sox11 and Sox4 is temporally sequential, albeit spatially overlapping in some retinal subtypes. Gain-of-function and loss-of-function analyses suggested that Notch signaling suppresses Sox4 expression in the early developing retina but not during the later period of development. The levels of histone H3-acetylation and H3-lysine 4 tri-methylation at the Sox11 locus declined during development, as did the levels of Sox11. A similar but less marked change was seen for Sox4. For both genes, histone H3-lysine 27 methylation was low during development and increased markedly in the adult.

Mantle cell lymphoma: a clinically heterogeneous disease in need of tailored approaches

BACKGROUND

Mantle cell lymphoma (MCL) remains incurable using conventional chemotherapeutic approaches. New clinical data show that some patients have a chronic/indolent course and others have a more fulminant course and short survival, similar to that of patients with acute leukemias.

METHODS

This review presents an overview of this aggressive disease, including the diagnosis, epidemiology, prognosis, and management of this protean and challenging condition.

RESULTS

Distinguishing indolent MCL from in situ MCL is important but can be challenging. Molecular exploration has identified SOX11 and HDAC11 as potential candidate genes for discrimination of indolent cases. Improvements in the prognosis in MCL are likely the result of earlier identification of more indolent cases and the application of modern modalities, including rituximab and autologous transplantation. Younger patients may be able to tolerate more intensive therapy, while treatment for elderly or frail patients may focus on maintenance to prolong remission. For patients with relapsed disease, some agents have shown promise, such as lenalidomide and bortezomib. Emerging drugs such as PCI37625 and CAL-101 are being explored in phase I and II studies.

CONCLUSIONS

Although patients with MCL continue to experience poor outcomes, new treatment approaches for various stages of disease are showing promise in improving survival.

Expanded clinical and experimental use of SOX11 - using a monoclonal antibody

BACKGROUND

The transcription factor SOX11 is of diagnostic and prognostic importance in mantle cell lymphoma (MCL) and epithelial ovarian cancer (EOC), respectively. Thus, there is an unmet clinical and experimental need for SOX11-targeting assays with low background, high specificity and robust performance in multiple applications, including immunohistochemistry (IHC-P) and flow cytometry, which until now has been lacking.

METHODS

We have developed SOX11-C1, a monoclonal mouse antibody targeting SOX11, and successfully evaluated its performance in western blots (WB), IHC-P, fluorescence microscopy and flow cytometry.

RESULTS

We confirm the importance of SOX11 as a diagnostic antigen in MCL as 100% of tissue micro array (TMA) cases show bright nuclear staining, using the SOX11-C1 antibody in IHC-P. We also show that previous reports of weak SOX11 immunostaining in a fraction of hairy cell leukemias (HCL) are not confirmed using SOX11-C1, which is consistent with the lack of transcription. Thus, high sensitivity and improved specificity are demonstrated using the monoclonal SOX11-C1 antibody. Furthermore, we show for the first time that flow cytometry can be used to separate SOX11 positive and negative cell lines and primary tumors. Of note, SOX11-C1 shows no nonspecific binding to primary B or T cells in blood and thus, can be used for analysis of B and T cell lymphomas from complex clinical samples. Dilution experiments showed that low frequencies of malignant cells (~1%) are detectable above background using SOX11 as a discriminant antigen in flow cytometry.

CONCLUSIONS

The novel monoclonal SOX11-specific antibody offers high sensitivity and improved specificity in IHC-P based detection of MCL and its expanded use in flow cytometry analysis of blood and tissue samples may allow a convenient approach to early diagnosis and follow-up of MCL patients.