Novel amplification unit at chromosome 3q25-q27 in human prostate cancer

ProstaMine: a bioinformatics tool for identifying subtype-specific co-alterations associated with aggressiveness in prostate cancer

Background

Prostate cancer is a leading cause of cancer-related deaths among men, marked by heterogeneous clinical and molecular characteristics. The complexity of the molecular landscape necessitates tools for identifying multi-gene co-alteration patterns that are associated with aggressive disease. The identification of such gene sets will allow for deeper characterization of the processes underlying prostate cancer progression and potentially lead to novel strategies for treatment.

Methods

We developed ProstaMine to systematically identify co-alterations associated with aggressiveness in prostate cancer molecular subtypes defined by high-fidelity alterations in primary prostate cancer. ProstaMine integrates genomic, transcriptomic, and clinical data from five primary and one metastatic prostate cancer cohorts to prioritize co-alterations enriched in metastatic disease and associated with disease progression.

Results

Integrated analysis of primary tumors defined a set of 17 prostate cancer alterations associated with aggressive characteristics. We applied ProstaMine to NKX3-1-loss and RB1-loss tumors and identified subtype-specific co-alterations associated with metastasis and biochemical relapse in these molecular subtypes. In NKX3-1-loss prostate cancer, ProstaMine identified novel subtype-specific co-alterations known to regulate prostate cancer signaling pathways including MAPK, NF-kB, p53, PI3K, and Sonic hedgehog. In RB1-loss prostate cancer, ProstaMine identified novel subtype-specific co-alterations involved in p53, STAT6, and MHC class I antigen presentation. Co-alterations impacting autophagy were noted in both molecular subtypes.

Conclusion

ProstaMine is a method to systematically identify novel subtype-specific co-alterations associated with aggressive characteristics in prostate cancer. The results from ProstaMine provide insights into potential subtype-specific mechanisms of prostate cancer progression which can be formed into testable experimental hypotheses. ProstaMine is publicly available at: https://bioinformatics.cuanschutz.edu/prostamine.

Knocking down SOX2 overcomes the resistance of prostate cancer to castration via notch signaling

BACKGROUND

Castration-resistant prostate cancer (CRPC) is a terminal type of advanced cancer resistant to androgen deprivation therapy (ADT). Due to the poor therapeutic response of CRPC, novel treatment strategies are urgently required. This study aimed to clarify the regulatory roles of the SOX2/Notch axis in CRPC.

METHODS

For the evaluation of the SOX2, Notch, and Hey1 expression in the prostate cancer (PCa) and CRPC tissues, we conducted immunohistochemistry (IHC) analyses. RT-PCR, Western blotting, and immunofluorescence were performed to evaluate SOX2 and Notch expression in enzalutamide-resistant LNCaP cells (Enza-R). CCK-8, Transwell, Wound healing, and Western blotting assays were used to assess the viability, invasion, migration, cell cycle, and drug-resistant in Enza-R cells.

RESULTS

Compared to the PCa tissues, CRPC tissues exhibited significantly elevated SOX2, Notch1, and Hey1 expression. SOX2-positive patients were more likely to develop bone metastases than SOX2-negative ones. Significant activation of the signaling associated with SOX2 and Notch was detected in Enza-R cells. The suppression of SOX2 clearly inactivated the Notch signaling and inhibited malignant behaviors, including proliferation, invasion, migration, and drug resistance in Enza-R cells. Theγsecretase inhibitor, GSI-IX, abrogated the enzalutamide resistance by inhibiting Notch signaling in vitro in vitro. Also, GSI-IX alone had a significant anti-tumor effect in Enza-R cells.

CONCLUSION

We demonstrated that SOX2/Notch signaling was responsible for Enzalutamide resistance in CRPC. Targeting SOX2/Notch signaling might represent a new choice for the treatment and therapy of CRPC.

The pan-cancer lncRNA PLANE regulates an alternative splicing program to promote cancer pathogenesis

Genomic amplification of the distal portion of chromosome 3q, which encodes a number of oncogenic proteins, is one of the most frequent chromosomal abnormalities in malignancy. Here we functionally characterise a non-protein product of the 3q region, the long noncoding RNA (lncRNA) PLANE, which is upregulated in diverse cancer types through copy number gain as well as E2F1-mediated transcriptional activation. PLANE forms an RNA-RNA duplex with the nuclear receptor co-repressor 2 (NCOR2) pre-mRNA at intron 45, binds to heterogeneous ribonucleoprotein M (hnRNPM) and facilitates the association of hnRNPM with the intron, thus leading to repression of the alternative splicing (AS) event generating NCOR2-202, a major protein-coding NCOR2 AS variant. This is, at least in part, responsible for PLANE-mediated promotion of cancer cell proliferation and tumorigenicity. These results uncover the function and regulation of PLANE and suggest that PLANE may constitute a therapeutic target in the pan-cancer context.

Emerging Roles of PRDM Factors in Stem Cells and Neuronal System: Cofactor Dependent Regulation of PRDM3/16 and FOG1/2 (Novel PRDM Factors)

PRDI-BF1 (positive regulatory domain I-binding factor 1) and RIZ1 (retinoblastoma protein-interacting zinc finger gene 1) (PR) homologous domain containing (PRDM) transcription factors are expressed in neuronal and stem cell systems, and they exert multiple functions in a spatiotemporal manner. Therefore, it is believed that PRDM factors cooperate with a number of protein partners to regulate a critical set of genes required for maintenance of stem cell self-renewal and differentiation through genetic and epigenetic mechanisms. In this review, we summarize recent findings about the expression of PRDM factors and function in stem cell and neuronal systems with a focus on cofactor-dependent regulation of PRDM3/16 and FOG1/2. We put special attention on summarizing the effects of the PRDM proteins interaction with chromatin modulators (NuRD complex and CtBPs) on the stem cell characteristic and neuronal differentiation. Although PRDM factors are known to possess intrinsic enzyme activity, our literature analysis suggests that cofactor-dependent regulation of PRDM3/16 and FOG1/2 is also one of the important mechanisms to orchestrate bidirectional target gene regulation. Therefore, determining stem cell and neuronal-specific cofactors will help better understanding of PRDM3/16 and FOG1/2-controlled stem cell maintenance and neuronal differentiation. Finally, we discuss the clinical aspect of these PRDM factors in different diseases including cancer. Overall, this review will help further sharpen our knowledge of the function of the PRDM3/16 and FOG1/2 with hopes to open new research fields related to these factors in stem cell biology and neuroscience.

Down-regulation of lncRNA UCA1 enhances radiosensitivity in prostate cancer by suppressing EIF4G1 expression via sponging miR-331-3p

BACKGROUND

We aimed to explore the role of long noncoding RNA urothelial carcinoma-associated 1 (lncRNA UCA1) and its underlying mechanism in the radioresistance of prostate cancer (PCa).

METHODS

QRT-PCR was conducted to measure the expression of UCA1, microRNA-331-3p (miR-331-3p) and eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in PCa tissues and cells. The relative protein level was determined by western blot assay. Cell proliferation and apoptosis were detected by MTT, colony formation assay, and flow cytometry, respectively. The target interaction between miR-331-3p and UCA1 or EIF4G1 was predicted through bioinformatics analysis, and verified by dual-luciferase reporter gene assay system.

RESULTS

The high levels of UCA1 and EIF4G1 as well as the low level of miR-331-3p were observed in PCa tissues and cell lines. UCA1 and EIF4G1 expression were significantly upregulated by Gy radiation treatement. UCA1 or EIF4G1 knockdown repressed cell growth and enhanced cell apoptosis in 22RV1 and DU145 cells under radiation. Moreover, overexpression of EIF4G1 abolished UCA1 knockdown-induced effect on 6 Gy irradiated PCa cells. UCA1 sponged miR-331-3p to regulate EIF4G1 expression.

CONCLUSIONS

LncRNA UCA1 deletion suppressed the radioresistance to PCa by suppressing EIF4G1 expression via miR-331-3p. UCA1 acted as a potential regulator of radioresistance of PCa, providing a promising therapeutic target for PCa.

Multifaceted Role of PRDM Proteins in Human Cancer

The PR/SET domain family (PRDM) comprise a family of genes whose protein products share a conserved N-terminal PR [PRDI-BF1 (positive regulatory domain I-binding factor 1) and RIZ1 (retinoblastoma protein-interacting zinc finger gene 1)] homologous domain structurally and functionally similar to the catalytic SET [Su(var)3-9, enhancer-of-zeste and trithorax] domain of histone methyltransferases (HMTs). These genes are involved in epigenetic regulation of gene expression through their intrinsic HMTase activity or via interactions with other chromatin modifying enzymes. In this way they control a broad spectrum of biological processes, including proliferation and differentiation control, cell cycle progression, and maintenance of immune cell homeostasis. In cancer, tumor-specific dysfunctions of PRDM genes alter their expression by genetic and/or epigenetic modifications. A common characteristic of most PRDM genes is to encode for two main molecular variants with or without the PR domain. They are generated by either alternative splicing or alternative use of different promoters and play opposite roles, particularly in cancer where their imbalance can be often observed. In this scenario, PRDM proteins are involved in cancer onset, invasion, and metastasis and their altered expression is related to poor prognosis and clinical outcome. These functions strongly suggest their potential use in cancer management as diagnostic or prognostic tools and as new targets of therapeutic intervention.

EVI1 as a Marker for Lymph Node Metastasis in HNSCC

BACKGROUND

HNSCC is the sixth most common cancer in humans and has still a very poor prognosis. The treatment methods so far are very often associated with mutilation and impairment in the quality of life. Except for p16 expression, there are no reliable prognostic markers in HNSCC so far. Ecotropic Viral Integration Site 1 (EVI1) is a well-described prognostic marker in leukemia and different types of solid cancers. In these, a high EVI1 expression is associated with a poor prognosis. In HNSCC, it is not known so far if EVI1 has any prognostic relevance.

MATERIALS AND METHODS

We used our representative tissue cohort of 389 primary HNSCCs, of which 57.2% had one or more lymph node metastases. Here EVI1 expression was analyzed via immunohistochemistry and correlated with the clinical characteristics of these patients.

RESULTS

Although in HNSCC EVI1 expression does not predict poor survival, a high EVI1 expression in the primary tumor correlates with a lymph node metastatic disease.

CONCLUSION

Consequently, EVI1 may serve as a biomarker to predict an occult lymph node metastasis in a clinical nodal negative (cN0) HNSCC.

SRY‑related HMG box‑2 role in anaplastic thyroid cancer aggressiveness is related to the fibronectin 1 and PI3K/AKT pathway

Anaplastic thyroid cancer (ATC) is a rare thyroid tumor associated with high mortality rates; thus, the identification of novel molecular targets and the development of therapeutic strategies are urgently required. The present study aimed to investigate the role of SRY-related HMG box-2 (SOX2) in ATC cells and explore whether the underlying mechanism was associated with fibronectin 1 (FN1). The proliferative, migratory and invasive ability of ATC cell lines was investigated using Cell Counting Kit-8, colony formation, wound-healing and Transwell assays, respectively; SOX2 expression in FRO cells was knocked down using small interfering RNA and SOX2 overexpression in FRO cells was achieved using cDNA constructs; and reverse transcription-quantitative PCR and western blotting were used to identify the mechanism of action underlying the SOX-2 mediated increased in cell aggressive phenotypes. Increased protein expression levels of SOX2 protein were observed in ATC tissue, and FRO and 8505c ATC cell lines. SOX2 overexpression increased the cell viability, and proliferative, migratory and invasive abilities of FRO cell lines. SOX2 overexpression increased FN1, p65, phosphorylated PI3K and AKT expression levels, whereas the knockdown of SOX2 promoted the opposite effects. In conclusion, the present study suggested a possible model of SOX2-mediated gene regulation in ATC cells, in which the overexpression of SOX2 promoted FN1 expression via the PI3K/AKT signaling pathway to induce the aggressive phenotype of ATC. These findings may provide crucial molecular insights into ATC pathogenesis and may demonstrate potential to develop into novel therapeutic interventions for patients with ATC.

SOX2 in development and cancer biology

The transcription factor SOX2 is essential for embryonic development and plays a crucial role in maintaining the stemness of embryonic cells and various adult stem cell populations. On the other hand, dysregulation of SOX2 expression is associated with a multitude of cancer types and it has been shown that SOX2 positively affects cancer cell traits such as the capacity to proliferate, migrate, invade and metastasize. Moreover, there is growing evidence that SOX2 mediates resistance towards established cancer therapies and that it is expressed in cancer stem cells. These findings indicate that studying the role of SOX2 in the context of cancer progression could lead to the development of new therapeutic options. In this review, the current knowledge about the role of SOX2 in development, maintenance of stemness, cancer progression and the resistance towards cancer therapies is summarized.

Multisite analysis of high-grade serous epithelial ovarian cancers identifies genomic regions of focal and recurrent copy number alteration in 3q26.2 and 8q24.3

High-grade serous epithelial ovarian cancer (HGS-EOC) is a systemic disease, with marked intra and interpatient tumor heterogeneity. The issue of spatial and temporal heterogeneity has long been overlooked, hampering the possibility to identify those genomic alterations that persist, before and after therapy, in the genome of all tumor cells across the different anatomical districts. This knowledge is the first step to clarify those molecular determinants that characterize the tumor biology of HGS-EOC and their route toward malignancy. In our study, -omics data were generated from 79 snap frozen matched tumor biopsies, withdrawn before and after chemotherapy from 24 HGS-EOC patients, gathered together from independent cohorts. The landscape of somatic copy number alterations depicts a more homogenous and stable genomic portrait than the single nucleotide variant profile. Genomic identification of significant targets in cancer analysis identified two focal and minimal common regions (FMCRs) of amplification in the cytoband 3q26.2 (region α, 193 kb long) and 8q24.3 (region β, 495 kb long). Analysis in two external databases confirmed regions α and β are features of HGS-EOC. The MECOM gene is located in region α, and 15 genes are in region β. No functional data are yet available for the genes in the β region. In conclusion, we have identified for the first time two FMCRs of amplification in HGS-EOC, opening up a potential biological role in its etiopathogenesis.

The Contributions of Prostate Cancer Stem Cells in Prostate Cancer Initiation and Metastasis

Research in the last decade has clearly revealed a critical role of prostate cancer stem cells (PCSCs) in prostate cancer (PC). Prostate stem cells (PSCs) reside in both basal and luminal layers, and are the target cells of oncogenic transformation, suggesting a role of PCSCs in PC initiation. Mutations in PTEN, TP53, and RB1 commonly occur in PC, particularly in metastasis and castration-resistant PC. The loss of PTEN together with Ras activation induces partial epithelial–mesenchymal transition (EMT), which is a major mechanism that confers plasticity to cancer stem cells (CSCs) and PCSCs, which contributes to metastasis. While PTEN inactivation leads to PC, it is not sufficient for metastasis, the loss of PTEN concurrently with the inactivation of both TP53 and RB1 empower lineage plasticity in PC cells, which substantially promotes PC metastasis and the conversion to PC adenocarcinoma to neuroendocrine PC (NEPC), demonstrating the essential function of TP53 and RB1 in the suppression of PCSCs. TP53 and RB1 suppress lineage plasticity through the inhibition of SOX2 expression. In this review, we will discuss the current evidence supporting a major role of PCSCs in PC initiation and metastasis, as well as the underlying mechanisms regulating PCSCs. These discussions will be developed along with the cancer stem cell (CSC) knowledge in other cancer types.

Eukaryotic Translation Initiation Factor 4 Gamma 1 (eIF4G1) is upregulated during Prostate cancer progression and modulates cell growth and metastasis

eIF4G1, a critical component of the eIF4F complex, is required for cap-dependent mRNA translation, a process necessary for tumor growth and survival. However, the role of eIF4G1 has not been evaluated in Prostate Cancer (PCa). We observed an increased eIF4G1 protein levels in PCa tissues as compared to normal tissues. Analysis of the TCGA data revealed that eIF4G1 gene expression positively correlated with higher tumor grade and stage. Furthermore, eIF4G1 was over-expressed and or amplified, in 16% patients with metastatic PCa (SU2C/PCF Dream Team dataset) and in 59% of castration-resistant prostate cancer (CRPC) patients (Trento/Cornell/Broad dataset). We showed for the first time that eIF4G1 expression was increased in PCa and that increased eIF4G1 expression associated with tumor progression and metastasis. We also observed high protein levels of eIF4G1 in PCa cell lines and prostate tissues from the TRAMP model of PCa as compared to normal prostate cell line and prostate tissues from the wild type mice. Knockdown of eIF4G1 in PCa cells resulted in decreased Cyclin D1 and p-Rb protein level, cell cycle delay, reduced cell viability and proliferation, impaired clonogenic activity, reduced cell migration and decreased mRNA loading to polysomes. Treatment with eIF4G complex inhibitor also impaired prostasphere formation. eIF4G1 knockdown or treatment with eIF4G complex inhibitor sensitized CRPC cells to Enzalutamide and Bicalutamide. Our results showed that eIF4G1 plays an important role in PCa growth and therapeutic resistance. These data suggested that eIF4G1 functions as an oncoprotein and may serve as a novel target for intervention in PCa and CRPC.

The dark side of SOX2: cancer - a comprehensive overview

The pluripotency-associated transcription factor SOX2 is essential during mammalian embryogenesis and later in life, but SOX2 expression can also be highly detrimental. Over the past 10 years, SOX2 has been shown to be expressed in at least 25 different cancers. This review provides a comprehensive overview of the roles of SOX2 in cancer and focuses on two broad topics. The first delves into the expression and function of SOX2 in cancer focusing on the connection between SOX2 levels and tumor grade as well as patient survival. As part of this discussion, we address the developing connection between SOX2 expression and tumor drug resistance. We also call attention to an under-appreciated property of SOX2, its levels in actively proliferating tumor cells appear to be optimized to maximize tumor growth - too little or too much SOX2 dramatically alters tumor growth. The second topic of this review focuses on the exquisite array of molecular mechanisms that control the expression and transcriptional activity of SOX2. In addition to its complex regulation at the transcriptional level, SOX2 expression and activity are controlled carefully by microRNAs, long non-coding RNAs, and post-translational modifications. In the Conclusion and Future Perspectives section, we point out that there are still important unanswered questions. Addressing these questions is expected to lead to new insights into the functions of SOX2 in cancer, which will help design novels strategies for more effectively treating some of the most deadly cancers.

3q26-29 Amplification in head and neck squamous cell carcinoma: a review of established and prospective oncogenes

Head and neck squamous cell carcinoma (HNSCC) is significantly underrepresented in worldwide cancer research, yet survival rates for the disease have remained static for over 50 years. Distant metastasis is often present at the time of diagnosis, and is the primary cause of death in cancer patients. In the absence of routine effective targeted therapies, the standard of care treatment remains chemoradiation in combination with (often disfiguring) surgery. A defining characteristic of HNSCC is the amplification of a region of chromosome 3 (3q26-29), which is consistently associated with poorer patient outcome. This review provides an overview of the role the 3q26-29 region plays in HNSCC, in terms of both known and as yet undiscovered processes, which may have potential clinical relevance.

HER2 gene amplification in patients with prostate cancer: Evaluating a CISH-based method

Prostate cancer (PCa) is one of the most widespread malignancies in the world. The role of the human epidermal growth factor receptor 2 (HER2) in the pathogenesis and progression of human PCa remains poorly understood. In contradiction with breast cancer, studies on HER2 overexpression and gene amplification in PCa have produced varying results, although the HER2 oncogene has been implicated in the biology of numerous tumor types, and serves as a prognostic marker and therapeutic target in breast cancer. Technical challenges are considered the main reasons for data discrepancies. Amplification of the HER2 gene has previously been reported in PCa, in which it was associated with tumor progression. The present study aimed to evaluate the prevalence and clinical significance of HER2 amplification in PCa. A total of 32 biopsy samples obtained from human prostate adenocarcinomas were evaluated by chromogenic in situ hybridization (CISH) to determine the frequency of patients with HER2 gene amplifications. High copy numbers of HER2 were detected in 19 of the prostate tumors analyzed. The results of the present study suggested that, in patients without amplification of HER2, high levels of prostate-specific antigen or a high Gleason score were not significantly correlated with a high pathologic stage. Furthermore, amplification levels of the HER2 gene were directly associated with pathologic stage in patients with PCa. Therefore, the potential use of HER2 as a prognostic factor or therapeutic target for PCa warrants further study.

Ecotropic viral integration site 1, a novel oncogene in prostate cancer

Prostate cancer (PCa) is the most commonly diagnosed non-cutaneous cancer in men in the western world. Mutations in tumor suppressor genes and in oncogenes are important for PCa progression, whereas the role of stem cell proteins in prostate carcinogenesis is insufficiently examined. This study investigates the role of the transcriptional regulator Ecotropic Viral Integration site 1 (EVI1), known as an essential modulator of hematopoietic and leukemic stem cell biology, in prostate carcinogenesis. We show that in healthy prostatic tissue, EVI1 expression is confined to the prostate stem cell compartment located at the basal layer, as identified by the stem cell marker CD44. Instead, in a PCa progression cohort comprising 219 samples from patients with primary PCa, lymph node and distant metastases, EVI1 protein was heterogeneously distributed within samples and high expression is associated with tumor progression (P<0.001), suggesting EVI1 induction as a driver event. Functionally, short hairpin RNA-mediated knockdown of EVI1 inhibited proliferation, cell cycle progression, migratory capacity and anchorage-independent growth of human PCa cells, while enhancing their apoptosis sensitivity. Interestingly, modulation of EVI1 expression also strongly regulated stem cell properties (including expression of the stem cell marker SOX2) and in vivo tumor initiation capacity. Further emphasizing a functional correlation between EVI1 induction and tumor progression, upregulation of EVI1 expression was noted in experimentally derived docetaxel-resistant PCa cells. Importantly, knockdown of EVI1 in these cells restored sensitivity to docetaxel, in part by downregulating anti-apoptotic BCL2. Together, these data indicate EVI1 as a novel molecular regulator of PCa progression and therapy resistance that may control prostate carcinogenesis at the stem cell level.

Mitochondrial ribosomal protein S18-2 evokes chromosomal instability and transforms primary rat skin fibroblasts

We have shown earlier that overexpression of the human mitochondrial ribosomal protein MRPS18-2 (S18-2) led to immortalization of primary rat embryonic fibroblasts. The derived cells expressed the embryonic stem cell markers, and cellular pathways that control cell proliferation, oxidative phosphorylation, cellular respiration, and other redox reactions were activated in the immortalized cells.Here we report that, upon overexpression of S18-2 protein, primary rat skin fibroblasts underwent cell transformation. Cells passed more than 300 population doublings, and two out of three tested clones gave rise to tumors in experimental animals. Transformed cells showed anchorage-independent growth and loss of contact inhibition; they expressed epithelial markers, such as E-cadherin and β-catenin. Transformed cells showed increased telomerase activity, disturbance of the cell cycle, and chromosomal instability. Taken together, our data suggest that S18-2 is a newly identified oncoprotein that may be involved in cancerogenesis.

Long non-coding RNA SOX2OT: expression signature, splicing patterns, and emerging roles in pluripotency and tumorigenesis

SOX2 overlapping transcript (SOX2OT) is a long non-coding RNA which harbors one of the major regulators of pluripotency, SOX2 gene, in its intronic region. SOX2OT gene is mapped to human chromosome 3q26.3 (Chr3q26.3) locus and is extended in a high conserved region of over 700 kb. Little is known about the exact role of SOX2OT; however, recent studies have demonstrated a positive role for it in transcription regulation of SOX2 gene. Similar to SOX2, SOX2OT is highly expressed in embryonic stem cells and down-regulated upon the induction of differentiation. SOX2OT is dynamically regulated during the embryogenesis of vertebrates, and delimited to the brain in adult mice and human. Recently, the disregulation of SOX2OT expression and its concomitant expression with SOX2 have become highlighted in some somatic cancers including esophageal squamous cell carcinoma, lung squamous cell carcinoma, and breast cancer. Interestingly, SOX2OT is differentially spliced into multiple mRNA-like transcripts in stem and cancer cells. In this review, we are describing the structural and functional features of SOX2OT, with an emphasis on its expression signature, its splicing patterns and its critical function in the regulation of SOX2 expression during development and tumorigenesis.

Significant association of combination of OCT4, NANOG, and SOX2 gene polymorphisms in susceptibility and response to treatment in North Indian breast cancer patients

PURPOSE

Dysregulations of regulatory genes in embryonic stem cells (ESCs) gene polymorphisms may lead to breast cancer cell growth, differentiation, and tumor metastasis.

METHODS

Polymorphisms in OCT4 (rs3130932), NANOG (rs11055786), LIN28 (rs4274112), and SOX2 (rs11915160) genes were evaluated for susceptibility in 297 breast cancer females and 273 healthy controls from north Indian population. Response to neo-adjuvant chemotherapy was followed in 128 locally advanced breast cancer patients along with clinicopathological features. Genotyping was done using TaqMan allelic discrimination assays. Statistical analysis was performed using SPSS and multifactor dimensionality reduction (MDR).

RESULTS

For OCT4 gene polymorphism, protective effect of genotypes AC [P corr = 0.031, OR = 0.63 (0.44-0.91)] and AC+CC [P corr = 0.031, OR = 0.68 (0.48-0.95)] was seen in patients. However, no association of NANOG, LIN28, and SOX2 gene polymorphisms was found with overall breast cancer susceptibility. Further, significant association of AG+GG genotype [P corr = 0.021, OR = 6.08 (1.83-20.15)] and G allele [P corr = 0.021, OR = 3.07 (1.21-7.77)] of rs4274112 polymorphism was seen with positive lymph node. For OCT4, significant association of allele C was seen with patients having negative hormone receptor [P corr = 0.021, OR = 0.51 (0.29-0.90)], but no association of any of the studied polymorphisms individually was found with response to NACT. On MDR analysis, we found combination of SNPs SOX2 rs11915160, OCT4 rs3130932, and NANOG rs11055786 to be the best interaction model for predicting breast cancer risk [p for permutation test <10(-3), OR = 2.04 (1.43-2.910] and response to NACT [p for permutation test = 0.005, OR = 2.09 (1.24-3.52)].

CONCLUSION

Combination of genetic variants of ESCs gene may have a profound effect in breast cancer risk and response to NACT.

Emerging role of long non-coding RNA SOX2OT in SOX2 regulation in breast cancer

The transcription factor SOX2 is essential for maintaining pluripotency in a variety of stem cells. It has important functions during embryonic development, is involved in cancer stem cell maintenance, and is often deregulated in cancer. The mechanism of SOX2 regulation has yet to be clarified, but the SOX2 gene lies in an intron of a long multi-exon non-coding RNA called SOX2 overlapping transcript (SOX2OT). Here, we show that the expression of SOX2 and SOX2OT is concordant in breast cancer, differentially expressed in estrogen receptor positive and negative breast cancer samples and that both are up-regulated in suspension culture conditions that favor growth of stem cell phenotypes. Importantly, ectopic expression of SOX2OT led to an almost 20-fold increase in SOX2 expression, together with a reduced proliferation and increased breast cancer cell anchorage-independent growth. We propose that SOX2OT plays a key role in the induction and/or maintenance of SOX2 expression in breast cancer.

Activation of SOX2 expression by BRD4-NUT oncogenic fusion drives neoplastic transformation in NUT midline carcinoma

BRD4 is implicated in the pathogenesis of a number of different cancers. It is also the target of translocation t(15;19) that accounts for the highly aggressive NUT midline carcinoma (NMC). We discovered that t(15;19) NMC cells display the ability to grow into stem cell-like spheres and express an exceptionally high level of the stem cell marker, SOX2. The BRD4-NUT fusion oncogene resulting from t(15;19) translocation is required for the abnormal activation of SOX2, which drives the stem cell-like proliferation and cellular transformation in NMC cells. SOX2 knockdown phenocopies the effects of BRD4-NUT inhibition, whereas ectopic SOX2 expression rescues the phenotype. The BRD4-NUT-induced abnormal SOX2 activation was observed in multiple NMC cell lines as well as in NMC primary tumors. We further demonstrate that BRD4-NUT oncoprotein recruits p300 to stimulate transcription activation and that inhibition of p300 represses SOX2 transcription in NMC cells. These studies identify this stem cell marker as a novel BRD4-NUT target that supports the highly aggressive transforming activity of t(15;19) carcinomas. Our study provides new mechanistic insights for understanding how alteration of BRD4 function by BRD4-NUT oncogene leads to the highly malignant NMC carcinoma. Because abnormal stem cell self-renewal is frequently observed during tumor formation and metastasis, the aberrant stem cell-like proliferation associated with BRD4 dysregulation observed in NMC carcinoma may have implications for studying the oncogenic mechanism of other BRD4-associated tumors.

Roles of eukaryotic initiation factor 5A2 in human cancer

Eukaryotic initiation factor 5A (eIF5A), the only known cellular protein containing the amino acid hypusine, is an essential component of translation elongation. eIF5A2, one of the two isoforms in the eIF5A family, is reported to be a novel oncogenic protein in many types of human cancer. Both in vitro and in vivo studies showed that eIF5A2 could initiate tumor formation, enhance cancer cell growth, and increase cancer cell motility and metastasis by inducing epithelial-mesenchymal transition. Accumulatied evidence suggests that eIF5A2 is a useful biomarker in the prediction of cancer prognoses and serves as an anticancer molecular target. In this review, we will focus on updating current knowledge of the EIF5A2 gene in human cancers. The molecular mechanisms of EIF5A2 related to tumorigenesis will also be discussed.

SOX2 plays a critical role in EGFR-mediated self-renewal of human prostate cancer stem-like cells

SOX2 is an essential transcription factor for stem cells and plays a role in tumorigenesis, however its role in prostate cancer stem cells (PCSCs) remains unclear. We report here a significant upregulation of SOX2 at both mRNA and protein levels in DU145 PCSCs propagated as suspension spheres in vitro. The expression of SOX2 in DU145 PCSCs is positively regulated by epidermal growth factor receptor (EGFR) signaling. Activation of EGFR signaling, following the addition of epidermal growth factor (EGF) or ectopic expression of a constitutively-active EGFR mutant (EGFRvIII), increased SOX2 expression and the self-renewal of DU145 PCSCs. Conversely, a small molecule EGFR inhibitor (AG1478) blocked EGFR activation, reduced SOX2 expression and inhibited PCSC self-renewal activity, implicating SOX2 in mediating EGFR-dependent self-renewal of PCSCs. In line with this notion, ectopic SOX2 expression enhanced EGF-induced self-renewal of DU145 PCSCs, while SOX2 knockdown reduced PCSC self-renewal with EGF treatment no longer capable of enhancing their propagation. Furthermore, SOX2 knockdown reduced the capacity of DU145 PCSCs to grow under anchorage-independent conditions. Finally, DU145 PCSCs generated xenograft tumors more aggressively with elevated levels of SOX2 expression compared to xenograft tumors derived from non-PCSCs. Collectively, we provide evidence that SOX2 plays a critical role in EGFR-mediated self-renewal of DU145 PCSCs.

Pleiotropic function of SRY-related HMG box transcription factor 4 in regulation of tumorigenesis

In addition to their critical roles in embryonic development, cell fate decision, and differentiation, members of Sox (Sry-related high-mobility group box) family of transcription factors including Sox4 have been implicated in various cancers. Multiple studies have revealed an increased expression along with specific oncogenic function of Sox4 in tumors, while others observed a reduced expression of Sox4 in different types of malignancies and suppression of tumor initiation or progression by this protein. More interestingly, the prognostic value of Sox4 is debated due to obvious differences between various reports as well as inconsistencies within specific studies. This review summarizes our current understanding of Sox4 expression pattern and its transcription-dependent, as well as transcription-independent, functions in tumor initiation or progression and its correlation with patient survival. We also discuss the existing discrepancies between different reports and their possible explanations.

Silencing of ghrelin receptor expression inhibits endometrial cancer cell growth in vitro and in vivo

Ghrelin is a 28-amino acid peptide hormone produced predominantly in the stomach but also in a range of normal cell types and tumors, where it has endocrine, paracrine, and autocrine roles. Previously, we have demonstrated that ghrelin has proliferative and antiapoptotic effects in endometrial cancer cell lines, suggesting a potential role in promoting tumor growth. In the present study, we investigated the effect of ghrelin receptor, GHSR, and gene silencing in vitro and in vivo and characterized ghrelin and GHSR1a protein expression in human endometrial tumors. GHSR gene silencing was achieved in the Ishikawa and KLE endometrial cancer cell lines, using a lentiviral short-hairpin RNA targeting GHSR. The effects of GHSR1a knockdown were further analyzed in vivo using the Ishikawa cell line in a NOD/SCID xenograft model. Cell proliferation was reduced in cultured GHSR1a knockdown Ishikawa and KLE cells compared with scrambled controls in the absence of exogenously applied ghrelin and in response to exogenous ghrelin (1,000 nM). The tumor volumes were reduced significantly in GHSR1a knockdown Ishikawa mouse xenograft tumors compared with scrambled control tumours. Using immunohistochemistry, we demonstrated that ghrelin and GHSR1a are expressed in benign and cancerous glands in human endometrial tissue specimens, although there was no correlation between the intensity of staining and cancer grade. These data indicate that downregulation of GHSR expression significantly inhibits endometrial cancer cell line and mouse xenograft tumour growth. This is the first preclinical evidence that downregulation of GHSR may be therapeutic in endometrial cancer.

Eukaryotic translation initiation factors in cancer development and progression

Eukaryotic gene expression is a complicated process primarily regulated at the levels of gene transcription and mRNA translation. The latter involves four main steps: initiation, elongation, termination and recycling. Translation regulation is primarily achieved during initiation which is orchestrated by 12 currently known eukaryotic initiation factors (eIFs). Here, we review the current state of eIF research and present a concise summary of the various eIF subunits. As eIFs turned out to be critically implicated in different oncogenic processes the various eIF members and their contribution to onset and progression of cancer are featured.

The ghrelin axis--does it have an appetite for cancer progression?

Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHSR), is a peptide hormone with diverse physiological roles. Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems. Ghrelin and the GHSR are expressed in a wide range of normal and tumor tissues, and a fluorescein-labeled, truncated form of ghrelin is showing promise as a biomarker for prostate cancer. Plasma ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a biomarker for cancer, but may be useful as a marker for cancer cachexia. Some single nucleotide polymorphisms in the ghrelin and GHSR genes have shown associations with cancer risk; however, larger studies are required. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, inflammation, and angiogenesis; however, the role of ghrelin in cancer is currently unclear. Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against cancer-related inflammation. Ghrelin and its analogs show promise as treatments for cancer-related cachexia. Further studies using in vivo models are required to determine whether ghrelin has a role in cancer progression.

Genetic heterogeneity in Finnish hereditary prostate cancer using ordered subset analysis

Prostate cancer (PrCa) is the most common male cancer in developed countries and the second most common cause of cancer death after lung cancer. We recently reported a genome-wide linkage scan in 69 Finnish hereditary PrCa (HPC) families, which replicated the HPC9 locus on 17q21-q22 and identified a locus on 2q37. The aim of this study was to identify and to detect other loci linked to HPC. Here we used ordered subset analysis (OSA), conditioned on nonparametric linkage to these loci to detect other loci linked to HPC in subsets of families, but not the overall sample. We analyzed the families based on their evidence for linkage to chromosome 2, chromosome 17 and a maximum score using the strongest evidence of linkage from either of the two loci. Significant linkage to a 5-cM linkage interval with a peak OSA nonparametric allele-sharing LOD score of 4.876 on Xq26.3-q27 (ΔLOD=3.193, empirical P=0.009) was observed in a subset of 41 families weakly linked to 2q37, overlapping the HPCX1 locus. Two peaks that were novel to the analysis combining linkage evidence from both primary loci were identified; 18q12.1-q12.2 (OSA LOD=2.541, ΔLOD=1.651, P=0.03) and 22q11.1-q11.21 (OSA LOD=2.395, ΔLOD=2.36, P=0.006), which is close to HPC6. Using OSA allows us to find additional loci linked to HPC in subsets of families, and underlines the complex genetic heterogeneity of HPC even in highly aggregated families.

Aberrant expression and biological significance of Sox2, an embryonic stem cell transcriptional factor, in ALK-positive anaplastic large cell lymphoma

Sox2 (sex-determining region Y-Box) is one of the master transcriptional factors that are important in maintaining the pluripotency of embryonic stem cells (ESCs). In line with this function, Sox2 expression is largely restricted to ESCs and somatic stem cells. We report that Sox2 is expressed in cell lines and tumor samples derived from ALK-positive anaplastic large cell lymphoma (ALK⁺ALCL), for which the normal cellular counterpart is believed to be mature T-cells. The expression of Sox2 in ALK⁺ALCL can be attributed to nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), the oncogenic fusion protein carrying a central pathogenetic role in these tumors. By confocal microscopy, Sox2 protein was detectable in virtually all cells in ALK⁺ALCL cell lines. However, the transcriptional activity of Sox2, as assessed using a Sox2-responsive reporter construct, was detectable only in a small proportion of cells. Importantly, downregulation of Sox2 using short interfering RNA in isolated Sox2^active cells, but not Sox2^inactive cells, resulted in a significant decrease in cell growth, invasiveness and tumorigenicity. To conclude, ALK⁺ALCL represents the first example of a hematologic malignancy that aberrantly expresses Sox2, which represents a novel mechanism by which NPM-ALK mediates tumorigenesis. We also found that the transcriptional activity and oncogenic effects of Sox2 can be heterogeneous in cancer cells.

Increased Levels of Circulating and Tissue mRNAs of Oct-4, Sox-2, Bmi-1 and Nanog is ESCC Patients: Potential Tool for Minimally Invasive Cancer Diagnosis

Background

Early stages of esophageal cancer lack a specific symptom, a reliable biomarker and accurate non-invasive diagnostic modalities prompting the pressing need for identification of a marker for early diagnosis of this disease.

Methods

In the present study we investigated the levels of circulating and tissue mRNAs of Oct-3/4, Sox-2, Nanog and Bmi-1 in esophageal cancer patients using Reverse-Transcription Polymerase Chain Reaction (RT-PCR) with the aim of evaluating their potential as minimally invasive diagnostic markers.

Result

Increased transcript levels of Oct-4, Sox-2, Bmi-1 and Nanog were detected in (92%), (95%), (75%) and (67%) of the esophageal cancer tissues, respectively as compared with the matched distant normals.

Conclusion

Interestingly, most of the preneoplastic tissues exhibited increased transcript levels of these stemness markers suggesting their role in early stages of esophageal tumorigenesis. Furthermore, the detection of elevated levels of circulating mRNAs of Oct-4 and Nanog in sera of esophageal cancer patients emphasizes their potential as minimally invasive diagnostic markers for esophageal cancer.

Implications of the Use of Eukaryotic Translation Initiation Factor 5A (eIF5A) for Prognosis and Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy and accounts for most of the total liver cancer cases. Lack of treatment options and late diagnosis contribute to high mortality rate of HCC. In eukaryotes, translation of messenger RNA (mRNA) to protein is a key process in protein biosynthesis in which initiation of translation involves interaction of different eukaryotic translation initiation factors (eIFs), ribosome subunits and mRNAs. Eukaryotic translation initiation factor 5A (eIF5A) is one of the eIFs involved in translation initiation and eIF5A2, one of its isoforms, is upregulated in various cancers including HCC as a result of chromosomal instability, where it resides. In HCC, eIF5A2 expression is associated with adverse prognosis such as presence of tumor metastasis and venous infiltration. Based on eIF5A2 functional studies, suppressing eIF5A2 expression by short interfering RNA alleviates the tumorigenic properties of HCC cells in vitro while ectopic expression of eIF5A2 enhances the aggressiveness of HCC cells in vivo and in vitro by inducing epithelial-mesenchymal transition. In conclusion, eIF5A2 is a potential prognostic marker as well as a therapeutic target for HCC.

DeltaN TP63 reactivation, epithelial phenotype maintenance, and survival in lung squamous cell carcinoma

Genes, active during normal development, are frequently reactivated during neoplastic transformation and may be related to progression. One of them, the transcription factor TP63, is crucial for pulmonary epithelial development and a possible target of the recurrent 3q amplifications in lung squamous cell carcinoma (SCC). Here, we explored whether TP63 reactivation could be associated to cancer progression in lung SCC through an epithelial to mesenchymal transition. We studied TP63 amplification and TP63 expression at RNA and protein levels and we analyzed the ΔNTP63/TATP63 ratio that quantifies the proportion of the isoform lacking the transactivation domain/the isoform containing the transactivation domain. We correlated TP63 status to survival and to the expression of epithelial (E-cadherin and plakoglobin) and mesenchymal (N-cadherin, vimentin, TWIST1, and SNAIL) markers. We found that high ΔN/TA TP63 ratio was related to high E-cadherin and plakoglobin mRNA levels (P < 0.05) and that E-cadherin mRNA level was the only marker related to survival. Kaplan-Meier survival curves stratified according to the expression level of E-cadherin showed, as already reported in breast cancer, that patients with low (first quartile) or high (last quartile) E-cadherin expression had a worse survival with respect to patients with intermediate E-cadherin expression. Altogether, our results indicate that a reactivation of ΔNTP63 is linked to the maintenance of epithelial markers and suggest that E-cadherin has a dual role in lung SCC.

Translational control gone awry: a new mechanism of tumorigenesis and novel targets of cancer treatments

Translational control is one of primary regulation mechanisms of gene expression. Eukaryotic translational control mainly occurs at the initiation step, the speed-limiting step, which involves more than ten translation initiation factors [eIFs (eukaryotic initiation factors)]. Changing the level or function of these eIFs results in abnormal translation of specific mRNAs and consequently abnormal growth of cells that leads to human diseases, including cancer. Accumulating evidence from recent studies showed that the expression of many eIFs was associated with malignant transformation, cancer prognosis, as well as gene expression regulation. In the present paper, we perform a critical review of recent advances in understanding the role and mechanism of eIF action in translational control and cancer as well as the possibility of targeting eIFs for therapeutic development.

Sox2 expression in breast tumours and activation in breast cancer stem cells

The cancer stem cell (CSC) model does not imply that tumours are generated from transformed tissue stem cells. The target of transformation could be a tissue stem cell, a progenitor cell, or a differentiated cell that acquires self-renewal ability. The observation that induced pluripotency reprogramming and cancer are related has lead to the speculation that CSCs may arise through a reprogramming-like mechanism. Expression of pluripotency genes (Oct4, Nanog and Sox2) was tested in breast tumours by immunohistochemistry and it was found that Sox2 is expressed in early stage breast tumours. However, expression of Oct4 or Nanog was not found. Mammosphere formation in culture was used to reveal stem cell properties, where expression of Sox2, but not Oct4 or Nanog, was induced. Over-expression of Sox2 increased mammosphere formation, effect dependent on continuous Sox2 expression; furthermore, Sox2 knockdown prevented mammosphere formation and delayed tumour formation in xenograft tumour initiation models. Induction of Sox2 expression was achieved through activation of the distal enhancer of Sox2 promoter upon sphere formation, the same element that controls Sox2 transcription in pluripotent stem cells. These findings suggest that reactivation of Sox2 represents an early step in breast tumour initiation, explaining tumour heterogeneity by placing the tumour-initiating event in any cell along the axis of mammary differentiation.

Silencing of the SEC62 gene inhibits migratory and invasive potential of various tumor cells

Sec62 is part of the protein translocation apparatus in the membrane of the endoplasmic reticulum (ER). In yeast, Sec62 participates in the post-translational translocation of proteins into the ER, but its function in mammals remains elusive. Previously we described the amplification and over-expression of the SEC62 gene in prostate cancer cell lines and the protein has been described as a potential target gene in prostate cancer. In the current study we show that in the tumor tissue of prostate cancer patients Sec62 protein levels are elevated compared with tumor-free tissue derived from the same patients or from prostates of control group patients and that the higher Sec62 protein content correlates with an increasing de-differentiation of the cells. Therefore, up-regulation of Sec62 protein content indeed is a phenomenon associated with prostate cancer progression. Analysis of a multi-tissue tumor array showed that in addition to prostate cancer, overproduction of Sec62 is observed in various other tumors, most significantly in tumors of the lung and the thyroid. To examine the tumor-related functions of Sec62, we silenced the SEC62 gene in the prostate cancer cell-line PC3 as well as in a set of other tumor cell-lines with two different siRNAs. In general, after silencing of SEC62 the cell migration and the invasive potential of the cells was blocked or at least dramatically reduced while cell viability was hardly affected. Thus, the SEC62 gene may indeed be considered as a target gene in the therapy of various tumors.

Downregulation of transcription factor SOX2 in cancer stem cells suppresses growth and metastasis of lung cancer

Background:

The cancer stem cell hypothesis suggests that neoplastic clones are maintained exclusively by a small subpopulation of cells, which have indefinite proliferation and differentiation potentials and give rise to phenotypically diverse cancer cells. Cancer stem cells have been isolated by their ability to efflux Hoechst 33342 dye and are referred to as the ‘side population’ (SP).

Methods and results:

The Hoechst efflux assay was used to isolate and characterize the SP from murine D121 lung carcinoma cells. Here, we demonstrated that D121-SP cells contain cancer stem cell characteristics, that is, upregulation of the transcription factors SOX2 and Oct 4 in D121-SP cells. In addition, the migration of D121-SP was decreased, and apoptosis of D121-SP was upregulated following knocking down of SOX2 in D121 cells. Importantly, downregulation of SOX2 in D121 cells markedly suppressed their metastatic potential in syngeneic mice.

Conclusions:

These results suggest that the SP is an enriched source of lung tumour cells with stem cell properties and that SOX2 has an important role in maintaining stem cell properties and functions that may be a potential target for effective lung cancer therapy.

Activation of neural and pluripotent stem cell signatures correlates with increased malignancy in human glioma

The presence of stem cell characteristics in glioma cells raises the possibility that mechanisms promoting the maintenance and self-renewal of tissue specific stem cells have a similar function in tumor cells. Here we characterized human gliomas of various malignancy grades for the expression of stem cell regulatory proteins. We show that cells in high grade glioma co-express an array of markers defining neural stem cells (NSCs) and that these proteins can fulfill similar functions in tumor cells as in NSCs. However, in contrast to NSCs glioma cells co-express neural proteins together with pluripotent stem cell markers, including the transcription factors Oct4, Sox2, Nanog and Klf4. In line with this finding, in high grade gliomas mesodermal- and endodermal-specific transcription factors were detected together with neural proteins, a combination of lineage markers not normally present in the central nervous system. Persistent presence of pluripotent stem cell traits could only be detected in solid tumors, and observations based on in vitro studies and xenograft transplantations in mice imply that this presence is dependent on the combined activity of intrinsic and extrinsic regulatory cues. Together these results demonstrate a general deregulated expression of neural and pluripotent stem cell traits in malignant human gliomas, and indicate that stem cell regulatory factors may provide significant targets for therapeutic strategies.

The p53 target Wig-1: a regulator of mRNA stability and stem cell fate?

Wig-1 is a transcriptional target of the tumor suppressor p53 and encodes an unusual zinc-finger protein involved in post-transcriptional gene regulation. Wig-1 is expressed in all cell types investigated so far, with the highest levels in the brain, and is enriched in stem cells as compared with more differentiated cells of the same lineage. Wig-1 binds to both long double-stranded (ds) RNA and short microRNA-like dsRNA. We have shown that Wig-1 acts in a positive feedback loop that stabilizes p53 mRNA through an AU-rich element (ARE) in the p53 3'untranslated region. Our preliminary data indicate a more general effect of Wig-1 on ARE-containing mRNA. Here we shall summarize current knowledge about Wig-1 and discuss possible implications on p53 function and other cellular processes.

Expression of the embryonic stem cell marker SOX2 in early-stage breast carcinoma

Background

The SRY-related HMG-box family of transcription factors member SOX2 has been mainly studied in embryonic stem cells as well as early foregut and neural development. More recently, SOX2 was shown to participate in reprogramming of adult somatic cells to a pluripotent stem cell state and implicated in tumorigenesis in various organs. In breast cancer, SOX2 expression was reported as a feature of basal-like tumors. In this study, we assessed SOX2 expression in 95 primary tumors of postmenopausal breast cancer patients.

Methods

Samples from 95 patients diagnosed and treated at the University of Tuebingen Institute of Pathology and Women's Hospital were analyzed by immunohistochemistry for SOX2 expression in the primary tumor samples and in corresponding lymph node metastasis, where present. Furthermore, SOX2 amplification status was assessed by FISH in representative samples. In addition, eighteen fresh frozen samples were analyzed for SOX2, NANOG and OCT4 gene expression by real-time PCR.

Results

SOX2 expression was detected in 28% of invasive breast carcinoma as well as in 44% of ductal carcinoma in situ (DCIS) lesions. A score of SOX2 expression (score 0 to 3) was defined in order to distinguish SOX2 negative (score 0) from SOX2 positive samples (score 1-3) and among latter the subgroup of SOX2 high expressors (score 3 > 50% positive cells). Overall, the incidence of SOX2 expression (score 1-3) was higher than previously reported in a cohort of lymph node negative patients (28% versus 16.7%). SOX2 expression was detected across different breast cancer subtypes and did not correlate with tumor grading. However, high SOX2 expression (score 3) was associated with larger tumor size (p = 0.047) and positive lymph node status (0.018). Corresponding metastatic lymph nodes showed higher SOX2 expression and were significantly more often SOX2 positive than primary tumors (p = 0.0432).

Conclusions

In this report, we show that the embryonic stem cell factor SOX2 is expressed in a variety of early stage postmenopausal breast carcinomas and metastatic lymph nodes. Our data suggest that SOX2 plays an early role in breast carcinogenesis and high expression may promote metastatic potential. Further studies are needed to explore whether SOX2 can predict metastatic potential at an early tumor stage.

SOX2 identified as a target gene for the amplification at 3q26 that is frequently detected in esophageal squamous cell carcinoma

SOX2 is a transcription factor with a high-mobility group DNA-binding domain that functions as a master regulator during embryogenesis and organogenesis. We investigated DNA copy number aberrations in esophageal squamous cell carcinoma (ESCC) cell lines using a high-density oligonucleotide microarray and found frequent amplification at the chromosomal region 3q26. The estimated extent of the minimal overlapping region of amplification was 1.3 Mb. This chromosomal region includes a single gene, SOX2. The SOX2 protein was overexpressed in cell lines in which the gene was amplified. Knockdown experiments showed that SOX2 promotes proliferation of ESCC cells. Genes potentially modulated by SOX2 were determined by expression array analyses combined with small interfering RNA cell-transfection studies. A copy number gain of SOX2 (>2-fold) was observed in 6 of the 40 primary ESCCs (15%). Immunohistochemical study revealed that expression of the SOX2 protein was significantly elevated in 62 of the 89 ESCC tumors (70%), compared with their nontumorous counterparts, and that upregulated expression of SOX2 was associated with poor differentiation of ESCC. Our results suggest that SOX2 is likely to be a target of the 3q26 amplification and may therefore be involved in the development or progression of ESCC.

Evidence that SOX2 overexpression is oncogenic in the lung

Background

SOX2 (Sry-box 2) is required to maintain a variety of stem cells, is overexpressed in some solid tumors, and is expressed in epithelial cells of the lung.

Methodology/Principal Findings

We show that SOX2 is overexpressed in human squamous cell lung tumors and some adenocarcinomas. We have generated mouse models in which Sox2 is upregulated in epithelial cells of the lung during development and in the adult. In both cases, overexpression leads to extensive hyperplasia. In the terminal bronchioles, a trachea-like pseudostratified epithelium develops with p63-positive cells underlying columnar cells. Over 12–34 weeks, about half of the mice expressing the highest levels of Sox2 develop carcinoma. These tumors resemble adenocarcinoma but express the squamous marker, Trp63 (p63).

Conclusions

These findings demonstrate that Sox2 overexpression both induces a proximal phenotype in the distal airways/alveoli and leads to cancer.

Diabetes genes and prostate cancer in the Atherosclerosis Risk in Communities study

There is a known inverse association between type 2 diabetes (T2D) and prostate cancer (PrCa) that is poorly understood. Genetic studies of the T2D-PrCa association may provide insight into the underlying mechanisms of this association. We evaluated associations in the Atherosclerosis Risk in Communities study between PrCa and nine T2D single nucleotide polymorphisms from genome-wide association studies of T2D (in CDKAL1, CDKN2A/B, FTO, HHEX, IGF2BP2, KCNJ11, PPARG, SLC30A8, and TCF7L2) and four T2D single nucleotide polymorphisms from pre-genome-wide association studies (in ADRB2, CAPN10, SLC2A2, and UCP2). From 1987 to 2000, there were 397 incident PrCa cases among 6,642 men ages 45 to 64 years at baseline. We used race-adjusted Cox proportional hazards models to estimate associations between PrCa and increasing number of T2D risk-raising alleles. PrCa was positively associated with the CAPN10 rs3792267 G allele [hazard ratio (HR) 1.20; 95% confidence interval (CI), 1.00-1.44] and inversely associated with the SLC2A2 rs5400 Thr110 allele (HR, 0.85; 95% CI, 0.72, 1.00), the UCP2 rs660339 Val55 allele (HR, 0.84; 95% CI, 0.73, 0.97) and the IGF2BP2 rs4402960 T allele (HR, 0.79; 95% CI, 0.61-1.02; blacks only). The TCF7L2 rs7903146 T allele was inversely associated with PrCa using a dominant genetic model (HR, 0.79; 95% CI, 0.65-0.97). Further knowledge of T2D gene-PrCa mechanisms may improve understanding of PrCa etiology.

Derivative (22)t(3;22)(q12;p11.1) in desmoplastic medulloblastoma

Medulloblastoma is a malignant invasive embryonal tumor of the cerebellum, representing 15-30% of pediatric brain tumors. An i(17q) abnormality appears in 40% of medulloblastomas, and usually not as a sole aberration; however, cytogenetic data for medulloblastoma are limited. Cytogenetic work-up of tumors is an important tool for diagnosis and prognosis, and in some cases has led to the development of new therapeutic modalities. In the present case, cytogenetic analysis of a medulloblastoma revealed an unbalanced karyotype in all cells analyzed: 46,XY,der(22)t(3;22)(q12;p11.1). This sole unbalanced translocation led to partial trisomy of 3q. The significance of this finding and its role in the pathogenesis of medulloblastoma need further clarification.