Erythroblast Transformation-specific Related Gene Research Articles

Erythroblast transformation-specific-related gene promotes metastasis of oral squamous cell carcinoma by transcriptionally upregulating peroxiredoxin 1.

Some studies confirmed that erythroblast transformation-specific-related gene (ERG) may be a pathogenic factor of oral squamous cell carcinoma (OSCC). However, the undergoing molecular mechanism has not been elucidated yet. In this study, the investigation will focus on how the transcription factor ERG modulates the biological behaviors of OSCC. In this study, cancer tissue specimens and corresponding paracancer tissues were collected from 54 patients. Real-time polymerase chain reaction analysis and Western blots were employed to detect the expression of multiple genes. Cell proliferation assays, Transwell, and flow cytometry assay were utilized to detect the proliferation, invasion, and apoptosis of OSCC cell, respectively. Dual luciferase reporter gene and chromatin immunoprecipitation assays were conducted to verify the regulation of ERG on PRDX1. ERG exhibits high expression levels in OSCC. Inhibition of ERG has been shown to effectively suppress the malignant growth of OSCC cells. Moreover, ERG has been found to transcriptionally upregulate the expression of PRDX1. The knockdown of PRDX1 has demonstrated its ability to inhibit the malignant growth of OSCC cells. Interestingly, when PRDX1 is overexpressed, it attenuates the inhibitory effect of si-ERG on the malignant growth of OSCC cells. This suggests that PRDX1 may play a crucial role in mediating the impact of ERG on malignancy in OSCC cells. The transcription factor ERG promotes the expression of PRDX1, which could enhance the proliferation and invasion while inhibiting the apoptosis of OSCC cells.

An intricate regulatory circuit between FLI1 and GATA1/GATA2/LDB1/ERG dictates erythroid vs. megakaryocytic differentiation.

During hematopoiesis, megakaryocytic erythroid progenitors (MEPs) differentiate into megakaryocytic or erythroid lineages in response to specific transcriptional factors, yet the regulatory mechanism remains to be elucidated. Using the MEP‑like cell line HEL western blotting, RT‑qPCR, lentivirus‑mediated downregulation, flow cytometry as well as chromatin immunoprecipitation (ChIp) assay demonstrated that the E26 transformation‑specific (ETS) transcription factor friend leukemia integration factor 1 (Fli‑1) inhibits erythroid differentiation. The present study using these methods showed that while FLI1‑mediated downregulation of GATA binding protein 1 (GATA1) suppresses erythropoiesis, its direct transcriptional induction of GATA2 promotes megakaryocytic differentiation. GATA1 is also involved in megakaryocytic differentiation through regulation of GATA2. By contrast to FLI1, the ETS member erythroblast transformation‑specific‑related gene (ERG) negatively controls GATA2 and its overexpression through exogenous transfection blocks megakaryocytic differentiation. In addition, FLI1 regulates expression of LIM Domain Binding 1 (LDB1) during erythroid and megakaryocytic commitment, whereas shRNA‑mediated depletion of LDB1 downregulates FLI1 and GATA2 but increases GATA1 expression. In agreement, LDB1 ablation using shRNA lentivirus expression blocks megakaryocytic differentiation and modestly suppresses erythroid maturation. These results suggested that a certain threshold level of LDB1 expression enables FLI1 to block erythroid differentiation. Overall, FLI1 controlled the commitment of MEP to either erythroid or megakaryocytic lineage through an intricate regulation of GATA1/GATA2, LDB1 and ERG, exposing multiple targets for cell fate commitment and therapeutic intervention.

Loss of feedback regulation between FAM3B and androgen receptor driving prostate cancer progression.

Although the fusion of the transmembrane serine protease 2 gene (TMPRSS2) with the erythroblast transformation-specific-related gene (ERG), or TMPRSS2-ERG, occurs frequently in prostate cancer, its impact on clinical outcomes remains controversial. Roughly half of TMPRSS2-ERG fusions occur through intrachromosomal deletion of interstitial genes and the remainder via insertional chromosomal rearrangements. Because prostate cancers with deletion-derived TMPRSS2-ERG fusions are more aggressive than those with insertional fusions, we investigated the impact of interstitial gene loss on prostate cancer progression. We conducted an unbiased analysis of transcriptome data from large collections of prostate cancer samples and employed diverse in vitro and in vivo models combined with genetic approaches to characterize the interstitial gene loss that imposes the most important impact on clinical outcome. This analysis identified FAM3B as the top-ranked interstitial gene whose loss is associated with a poor prognosis. The association between FAM3B loss and poor clinical outcome extended to fusion-negative prostate cancers where FAM3B downregulation occurred through epigenetic imprinting. Importantly, FAM3B loss drives disease progression in prostate cancer. FAM3B acts as an intermediator of a self-governing androgen receptor feedback loop. Specifically, androgen receptor upregulates FAM3B expression by binding to an intronic enhancer to induce an enhancer RNA and facilitate enhancer-promoter looping. FAM3B, in turn, attenuates androgen receptor signaling. Loss of FAM3B in prostate cancer, whether through the TMPRSS2-ERG translocation or epigenetic imprinting, causes an exit from this autoregulatory loop to unleash androgen receptor activity and prostate cancer progression. These findings establish FAM3B loss as a new driver of prostate cancer progression and support the utility of FAM3B loss as a biomarker to better define aggressive prostate cancer.

Intercellular adhesion molecule 2 as a novel prospective tumor suppressor induced by ERG promotes ubiquitination-mediated radixin degradation to inhibit gastric cancer tumorigenicity and metastasis

BackgroundGastric cancer (GC) is a fatal cancer with unclear pathogenesis. In this study, we explored the function and potential mechanisms of intercellular adhesion molecule 2 (ICAM2) in the development and advancement of GC.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were performed to quantify ICAM2 expression in harvested GC tissues and cultured cell lines. Immunohistochemical analyses were conducted on a GC tissue microarray to quantify ICAM2 expression and explore its implication on the prognosis of GC patients. In vitro experiments were carried out to reveal the biological functions of ICAM2 in GC cell lines. Further, in vivo experiments were conducted using xenograft models to assess the impact of ICAM2 on GC development and metastasis. Western blot, immunofluorescence, immunoprecipitation, luciferase assay, chromatin immunoprecipitation, and ubiquitination analysis were employed to investigate the underlying mechanisms.ResultsICAM2 expression was downregulated in GC, positively correlating with advanced T stage, distant metastasis, advanced clinical stage, vessel invasion, and shorter patient survival time. ICAM2 overexpression suppressed the proliferation, migration, invasion, metastasis of GC cells as well as their ability to form tumors, whereas ICAM2 knockdown yielded opposite results. Erythroblast transformation-specific-related gene (ERG) as a transcription factor promoted the transcription of ICAM2 by binding to the crucial response element localized within its promoter region. Further analysis revealed that ICAM2 reduced radixin (RDX) protein stability and expression. In these cells, ICAM2 bound to the RDX protein to promote the ubiquitination and degradation of RDX via NEDD4 Like E3 Ubiquitin Protein Ligase (NEDD4L), and this post-translational modification resulted in the inhibition of GC.ConclusionsIn summary, this study demonstrates that ICAM2, which is induced by ERG, suppresses GC progression by enhancing the ubiquitination and degradation of RDX in a NEDD4L-dependent manner. Therefore, these results suggest that ICAM2 is a potential prognostic marker and a therapeutic target for GC.

Cytokine-Mediated Degradation of the Transcription Factor ERG Impacts the Pulmonary Vascular Response to Systemic Inflammatory Challenge.

During infectious diseases, proinflammatory cytokines transiently destabilize interactions between adjacent vascular endothelial cells (ECs) to facilitate the passage of immune molecules and cells into tissues. However, in the lung, the resulting vascular hyperpermeability can lead to organ dysfunction. Previous work identified the transcription factor ERG (erythroblast transformation-specific-related gene) as a master regulator of endothelial homeostasis. Here we investigate whether the sensitivity of pulmonary blood vessels to cytokine-induced destabilization is due to organotypic mechanisms affecting the ability of endothelial ERG to protect lung ECs from inflammatory injury. Cytokine-dependent ubiquitination and proteasomal degradation of ERG were analyzed in cultured human umbilical vein ECs. Systemic administration of TNFα (tumor necrosis factor alpha) or the bacterial cell wall component lipopolysaccharide was used to cause a widespread inflammatory challenge in mice; ERG protein levels were assessed by immunoprecipitation, immunoblot, and immunofluorescence. Murine Erg deletion was genetically induced in ECs (Ergfl/fl;Cdh5[PAC]-CreERT2), and multiple organs were analyzed by histology, immunostaining, and electron microscopy. In vitro, TNFα promoted the ubiquitination and degradation of ERG in human umbilical vein ECs, which was blocked by the proteasomal inhibitor MG132. In vivo, systemic administration of TNFα or lipopolysaccharide resulted in a rapid and substantial degradation of ERG within lung ECs but not ECs of the retina, heart, liver, or kidney. Pulmonary ERG was also downregulated in a murine model of influenza infection. Ergfl/fl;Cdh5(PAC)-CreERT2 mice spontaneously recapitulated aspects of inflammatory challenges, including lung-predominant vascular hyperpermeability, immune cell recruitment, and fibrosis. These phenotypes were associated with a lung-specific decrease in the expression of Tek-a gene target of ERG previously implicated in maintaining pulmonary vascular stability during inflammation. Collectively, our data highlight a unique role for ERG in pulmonary vascular function. We propose that cytokine-induced ERG degradation and subsequent transcriptional changes in lung ECs play critical roles in the destabilization of pulmonary blood vessels during infectious diseases.

PLVAP as an Early Marker of Glomerular Endothelial Damage in Mice with Diabetic Kidney Disease.

Plasmalemma vesicle-associated protein (PLVAP) is the main component of endothelial diaphragms in fenestrae, caveolae, and transendothelial channels. PLVAP is expressed in the adult kidney glomerulus upon injury. Glomerular endothelial injury is associated with progressive loss of kidney function in diabetic kidney disease (DKD). This study aimed to investigate whether PLVAP could serve as a marker for glomerular endothelial damage in DKD. Glomerular PLVAP expression was analyzed in different mouse models of DKD and their respective healthy control animals using automatic digital quantification of histological whole kidney sections. Transgenic mice expressing a dominant-negative GIP receptor (GIPRdn) in pancreatic beta-cells as a model for diabetes mellitus (DM) type 1 and black and tan brachyuric (BTBR) ob/ob mice, as a model for DM type 2, were used. Distinct PLVAP induction was observed in all diabetic models studied. Traces of glomerular PLVAP expression could be identified in the healthy control kidneys using automated quantification. Stainings for other endothelial injury markers such as CD31 or the erythroblast transformation-specific related gene (ERG) displayed no differences between diabetic and healthy groups at the time points when PLVAP was induced. The same was also true for the mesangial cells marker α8Integrin, while the podocyte marker nephrin appeared to be diminished only in BTBR ob/ob mice. Glomerular hypertrophy, which is one of the initial morphological signs of diabetic kidney damage, was observed in both diabetic models. These findings suggest that PLVAP is an early marker of glomerular endothelial injury in diabetes-induced kidney damage in mice.

Expression of ERG in Prostatic Acinar Adenocarcinoma Diagnosed on TRUS-guided Biopsy and its Association with WHO Grade Group- A Prospective Observational Study

Introduction: Prostate cancer is a common malignancy affecting men and the second leading cause of cancer related death in India. Numerous molecular biomarkers have been evaluated for their potential role in predicting disease progression, their response to therapy and survival. Erythroblast Transformation Specific (ETS) related Gene (ERG) is one of the newest addition in the existing list of biomarkers of prostate cancer. Aim: To analyse the expression of ERG in prostatic adenocarcinoma and to evaluate its association with World Health Organisation (WHO) grade group. Materials and Methods: This was a prospective observational study was conducted in the Department of Pathology in association with Department of Urology, IPGME&R, SSKM Hospital, Kolkata, West Bengal, India. The duration of the study was 1.5 years, from January 2019 to June 2020. A total of 267 cases of Transrectal Ultrasound (TRUS) guided tru-cut biopsy was included. Clinical data including preoperative Prostate Specific Antigen (PSA) level, Digital Rectal Examination (DRE) were obtained. Histopathological reports were prepared by two pathologists along with Gleason scoring and WHO grading as per 2014 International Society of Urological Pathology (ISUP) consensus conference on gleason grading of prostatic carcinoma. Formalin Fixed Paraffin Embedded (FFPE) sections of representative blocks of each tumour was selected for Immunohistochemistry (IHC) study. Only the cases which had more than 10% nuclear staining were considered as positive. Statistical analysis was performed with help of Epi Info (TM) 7.2.2.2 and Chi-square test was used to test the association of different study variables. Results: The mean age of the study participants was 65.55 years, and the age range was 45-93 years. Among the 80 malignant cases where, ERG immunostaining was assessed, 28 cases (35%) showed positive expression. Among these positive cases, 50% cases were weakly positive, 28.57% showed moderate positivity and 21.43% had strong positive expression. Highest positivity was observed in WHO grade group V (44.83%). The intensity of ERG expression was also higher in high grade group (13) than low grade group cancer patients. Conclusion: ERG expression in the prostate cancer can be a prognostic factor as the expression and intensity of expression both increases with higher grade group of cancer.

Diagnostic utility of ERG immunostaining in dermatofibroma

AimsDermatofibroma/fibrous histiocytoma (DF/FH) is a common cutaneous mesenchymal neoplasm exhibiting benign biological behaviour. However, the immunohistochemical utility of erythroblast transformation-specific-related gene (ERG) for diagnosing DF remains unknown. The authors reviewed...

Primary hepatic angiosarcoma in an elderly patient.

Primary hepatic angiosarcoma is a high-grade mesenchymal tumor with very aggressive behavior, and accounts for 0.1-2% of all liver malignancies.1 Most of the time, patients present with abdominal pain, fatigue, weight loss, hepatosplenomegaly, ascites, jaundice, and anemia. This neoplasm is known for intraperitoneal rupture. Poor prognostic factors include older age, large tumor size, and a high Ki-67 index. It occurs in association with exposure to known chemical carcinogens such as vinyl chloride monomer, thorotrast, anabolic steroids, and arsenic. However, in 75% of cases, the etiology is not known. The current molecular data revealed KRAS mutations in sporadic cases and TP53 mutations in vinyl chloride-related cases.2 Primary hepatic angiosarcoma may have different growth patterns on imaging. It includes 1) Multiple nodules, 2) Large dominant mass, 3) Mixed pattern of dominant mass with nodules, and 4) Diffuse infiltrating micronodular mass.3 The liver biopsy is the gold standard for confirming the diagnosis of primary hepatic angiosarcoma. Microscopically, the lesion is heterogeneous, ranging from well-defined anastomotic vessels (Vaso formative) to solid sheets of epithelioid or spindled cells; some tumors may show mixed patterns. Immunohistochemically, ERG (erythroblast transformation specific-related gene) and endothelial markers such as CD31 and CD34 show expression, indicating the endothelial origin of the tumor. D2-40 and CD10 may also show positivity. Of note, the epithelioid variant may show keratin expression. Surgical resection seems the best therapeutic option, leading to a median overall survival of between 17 and 19 months.4 We describe gross examination and supportive microscopic findings of primary hepatic angiosarcoma in a 66-year-old gentleman with no predisposing environmental risk factors. He presented with fatigue, weight loss, jaundice, abdominal pain, and swelling in the right hypochondrium. On investigation, he was found to have raised serum levels of ammonia (183.8 µmol/L; RR: 11-32 µmol/L), AST (89.5 U/L; RR: 5-40 U/L), ALT (77.6 U/L; RR: 7-56 U/L), ALP (410 IU/L; RR: 44-147 IU/L). Viral markers were negative, and the coagulation profile was within the normal limit. Hepatocellular carcinoma and Cholangiocarcinoma involving the right lobe were differential diagnoses based on clinical and imaging studies. Right hepatectomy was done and submitted for histopathological examination. Gross examination showed a dominant mass, measuring 18x10x5cm, and nodules of variable size. The liver capsule was smooth, shiny and there was no breach by the tumor. The cut surface of the tumor appeared variegated and showed pale white to yellowish firm areas with intervening areas of hemorrhage and necrosis (Figure 1 A). The adjacent native liver parenchyma was non-cirrhotic. Microscopically, the tumor was ill-defined, and the cells were arranged along with abortive vascular spaces and as clusters (Figure 1B). The tumor cells displayed moderate to marked degrees of nuclear pleomorphism with oval to plump to spindle-shaped vesicular nuclei, prominent nucleoli, and moderate eosinophilic cytoplasm (Figure 1C). Mitotic activity was brisk (>8 per 10 high power fields). Lymphovascular emboli were seen. Areas of necrosis and hemorrhage were present. The tumor cells exhibited membranous positivity for CD31 (Figure 1D) and CD34 immunomarkers. HepPar1, Arginase, and Keratin 7 were negative. Based on the light microscopy and immunohistochemistry findings, the diagnosis of primary hepatic angiosarcoma was offered. Figure 1 A – Gross view of the surgical specimen. Slices of right hepatectomy specimen showing the mixed growth pattern with dominant mass, measuring 18x10x5cm and nodules of variable size. Cut surface of the tumor showing pale white to yellowish firm areas with areas of hemorrhage and necrosis (scale bar = 15 cm); B – Microscopy showing an infiltrating tumor with areas of hemorrhage and fibrosis. (H&E,40 x); C – Higher magnification depicting the large, pleomorphic tumor cells lining the abortive sinusoids. (H&E, 200 x); D – Immunohistochemistry for CD31 showing membranous positivity in the tumor cells (400x).:

Clinicopathological Features and Expression of P504s,E-cadherin,Erythroblast Transformation-specific Related Gene and Estrogen Receptor in Prostate Adenocarcinoma in Tibet

Objective To investigate the clinicopathological features and immunohistochemical expression of P504s,E-cadherin,erythroblast transformation-specific related gene(ERG)and estrogen receptor(ER)in prostate adenocarcinoma in Tibet.Methods The clinical data of 15 patients with prostate adenocarcinoma diagnosed by the Department of Pathology of Tibet Autonomous Region People's Hospital from September 2013 to September 2020 were analyzed retrospectively.All patients were assigned to prognostic grade groups based on Gleason score according to the WHO 2016 criteria.Immunostaining of P504s,E-cadherin,ERG,and ER was performed.Results The age of all 15 patients ranged from 61 to 86 years.The serum prostate specific antigen(PSA)concentration was ≥20 ng/ml in 12 patients and<20 ng/ml in 3 patients.Among the 15 patients,11 underwent needle biopsy,1 transurethral resection of the prostate,and 3 radical prostatectomy.Prognostic grouping results revealed 5 cases in grade groups 1-3,4 cases in grade group 4,and 6 cases in grade group 5.Immunohistochemistrically,15 cases(100%)were positive for P504s,E-cadherin and PSA;one case(7%)was positive for ERG;all cases were negative for P63,ER and CK34βE12.Thirteen cases were followed up for 2-48 months,with 2 cases treated with total prostatectomy and 11 cases with non-surgical treatment.Two cases were lost to follow-up. Conclusions Prostate adenocarcinoma is rare relatively in Tibet.The accuracy of diagnosis can be improved by using multiple immunohistochemical markers.The cases of grades 4 and 5 by pathological confirmed are relatively common in Tibet.P504s and E-cadherin are highly expressed in prostate adenocarcinoma patients in Tibet,while ERG presents low expression,ER is unexpressed.

Successful endoscopic diagnosis of angiosarcoma of the small intestine: A case report.

A 51‐year‐old man had hematochezia, anemia, and an intraabdominal mass. Gastroscopy and colonoscopy showed no significant lesions with intraluminal bleeding, while radiological examinations showed bulky swelling of the lymph nodes around the abdominal aorta and a tumor in the left ischial bone. Small intestine endoscopy detected a dark purpuric protruding tumor of the jejunum and its biopsy specimen brought a definitive diagnosis of primary jejunal epithelioid angiosarcoma from positive staining of AE1/AE3, CD31, and erythroblast transformation specific related gene in immunohistochemical studies. The patient underwent surgical resection with adjuvant chemotherapy but died of progression of metastases 7 months after the diagnosis. Epithelioid angiosarcoma of the gastrointestinal tract is an extremely rare malignancy with poor prognosis and it is challenging to distinguish from undifferentiated carcinoma or melanoma. Immunohistochemistry is necessary for a definitive diagnosis. Sufficient biopsy specimen may aid a prompt diagnosis of this disease of the small intestine, which may present as obscure gastrointestinal bleeding.

Single-Cell Transcriptome Analysis Reveals Dynamic Cell Populations and Differential Gene Expression Patterns in Control and Aneurysmal Human Aortic Tissue.

Ascending thoracic aortic aneurysm (ATAA) is caused by the progressive weakening and dilatation of the aortic wall and can lead to aortic dissection, rupture, and other life-threatening complications. To improve our understanding of ATAA pathogenesis, we aimed to comprehensively characterize the cellular composition of the ascending aortic wall and to identify molecular alterations in each cell population of human ATAA tissues. We performed single-cell RNA sequencing analysis of ascending aortic tissues from 11 study participants, including 8 patients with ATAA (4 women and 4 men) and 3 control subjects (2 women and 1 man). Cells extracted from aortic tissue were analyzed and categorized with single-cell RNA sequencing data to perform cluster identification. ATAA-related changes were then examined by comparing the proportions of each cell type and the gene expression profiles between ATAA and control tissues. We also examined which genes may be critical for ATAA by performing the integrative analysis of our single-cell RNA sequencing data with publicly available data from genome-wide association studies. We identified 11 major cell types in human ascending aortic tissue; the high-resolution reclustering of these cells further divided them into 40 subtypes. Multiple subtypes were observed for smooth muscle cells, macrophages, and T lymphocytes, suggesting that these cells have multiple functional populations in the aortic wall. In general, ATAA tissues had fewer nonimmune cells and more immune cells, especially T lymphocytes, than control tissues did. Differential gene expression data suggested the presence of extensive mitochondrial dysfunction in ATAA tissues. In addition, integrative analysis of our single-cell RNA sequencing data with public genome-wide association study data and promoter capture Hi-C data suggested that the erythroblast transformation-specific related gene(ERG) exerts an important role in maintaining normal aortic wall function. Our study provides a comprehensive evaluation of the cellular composition of the ascending aortic wall and reveals how the gene expression landscape is altered in human ATAA tissue. The information from this study makes important contributions to our understanding of ATAA formation and progression.

PTEN and ERG expression in MRI-ultrasound guided fusion biopsy correlated with radical prostatectomy findings in men with prostate cancer.

Conventional systematic prostate biopsies (SBx) have multiple limitations, and magnetic resonance imaging (MRI)-ultrasound fusion targeting is increasingly applied (fusion biopsies [FBx]). In our previous studies, we have shown that loss of the tumor suppressor gene phosphatase and tensin homolog (PTEN) in radical prostatectomy (RP) specimens predicts poor disease-specific survival, andin active surveillance (AS), PTEN loss in SBx predicts an adverse AS outcome, although SBx PTEN status does not correlate well with the corresponding RP status. Here, we have hypothesized that PTEN and erythroblast transformation-specific related gene (ERG) status in FBx correlate better with RP than they would in SBx. A total of 106 men, who had undergone FBx and subsequent RP in a single center between June 2015 and May 2017 were included. Fifty-three of the men had concomitant or previous SBx's. All biopsy and RP specimens were collected, and tissue microarrays (TMA) were constructed from RP specimens. Immunohistochemical stainings for PTEN and ERG expression were conducted on biopsies and RP TMAs and results were compared by using Fisher's exact test. The immunohistochemical predictive power of FBx, determined by the concordance of biopsy PTEN and ERG status with RP, is superior to SBx (77.6% vs 66.7% in PTEN, 92.4% vs 66.6% in ERG). FBx was superior to SBx in correlation with RP Gleason Grade Groups and MRI prostate imaging reporting and data system scores. FBx grading correlates with RP histology and MRI findings and predicts the biomarker status in the RP specimens more accurately than SBx. A longer follow-up is needed to evaluate if this translates to better prediction of disease outcomes, especially in AS and radiation therapy where prostatectomy specimens are not available for prognostication.

Abstract IA38: What causes the increased risk of acute lymphoblastic leukemia in Latinos?

Abstract Acute lymphoblastic leukemia (ALL) is the most common childhood cancer and, despite high cure rates, remains one of the leading causes of cancer-related mortality in children. Moreover, childhood ALL survivors are faced with severe long-term treatment-related morbidities, including increased risk of cardiovascular disease, secondary cancers, and pulmonary disease. Children of Latino ethnicity have the highest incidence of ALL in the United States. This increased risk likely has a genetic component, although the rising incidence of ALL in recent decades, which is increasing fastest in Latinos, points towards a role for environmental exposures. In this talk, I will discuss recent research from our group and others that has shed light on the potential etiologies of the increased ALL risk in Latinos. Genome-wide association studies (GWAS) of childhood ALL have pinpointed several risk loci at genes involved in B-cell development and hematopoiesis. In our earlier studies of ALL in the genetically admixed Latino population of California, we capitalized on their altered linkage disequilibrium patterns (compared to non-Latino whites) to identify putative causal variants, including a missense SNP in CDKN2A. More recently, we performed a large multiethnic GWAS of ALL including Latinos, non-Latino whites, and African-Americans, and identified new ALL risk loci at 8q24 and IKZF3. Fine-mapping at known loci also helped to confirm an independent risk locus at chromosome 10p12.31 and pinpointed a likely causal variant in an enhancer region for BMI1. Our group and others previously showed that the risk allele frequencies of several loci, including ARID5B, PIP4K2A, and GATA3, are higher in Latino populations and are associated with Native American ancestry. In two recent, independent GWAS of ALL in Latinos, a novel risk locus was identified at the erythroblast transformation-specific (ETS)-related gene (ERG) on chromosome 21, which was found to confer stronger leukemia risk in Latinos than in non-Latino whites. Moreover, within Latinos the effect of this risk locus increased with increasing Native American ancestry. We subsequently confirmed ERG as the first identified genetic risk locus for ALL in children with Down syndrome (DS-ALL), in which the effect size was again stronger in Latino than in non-Latino white children with DS. Our research group has also identified varied associations between Latinos and non-Latino whites for risk factors pertaining to immune stimulation (childhood contacts) and infection (cytomegalovirus). Future studies of ALL risk factors in Latinos, including even larger GWAS, polygenic risk score analysis, admixture mapping, as well as continued investigation of environmental risk factors, will be critical for our understanding the etiology of this disease and for identifying possible avenues to reduce the ethnic disparity in ALL incidence. Citation Format: Adam J. de Smith, Qianxi Feng, Kyle M. Walsh, Soyoung Jeon, Libby M. Morimoto, Andrew T. DeWan, Charleston Chiang, Catherine Metayer, Xiaomei Ma, Joseph L. Wiemels. What causes the increased risk of acute lymphoblastic leukemia in Latinos? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr IA38.

Methamphetamine‐induced retinal hyperpermeability, hypoxia, and vascularization

PurposeMethamphetamine (METH), a highly addictive stimulant of neurotransmitters induces central retinal artery occlusion with retinal atrophy and neovascularization. We previously have identified METH‐induced loss of endothelial surface molecules including platelet and endothelial cell adhesion molecule‐1 (PECAM‐1) and glycocalyx in mice. However, the pathophysiologic pathway of METH‐induced retinal vascular dysfunction has been insufficiently investigated. The purpose of this study is to investigate the METH‐induced alteration of the retinal vascular circulation.Materials and methodsC57BL/6J male and female mice were administrated progressively increasing doses of METH (0 to 6 mg/kg) by repetitive intraperitoneal injections (4 times per day) for 4 weeks. Norepinephrine levels in plasma were measured by ELISA. Cross‐sections of the retina were stained with hematoxylin and eosin. Levels of hypoxia in the retina were determined by immunostaining of pimonidazole adducts with Hypoxyprobe. Retinal blood vessels were visualized with fluorescent plasma tracers injected via femoral vein injection for live imaging, and immunostained with griffonia simplicifolia lectin 1 (GSL‐1) for retinal flatmounts. Expression of various proteins was determined by immunoblot.ResultsThe level of pimonidazole adduct was increased in METH‐treated retinas, compared with saline‐treated retinas, indicating METH‐induced retinal hypoxia. Plasma norepinephrine levels, which can promote hypoxia‐inducible factor 1a (HIF‐1a) at the transcriptional level, were elevated by METH, compared with saline treatment at 1 week (2.2±0.9 vs 7.8±1.6 ng/mL, P&lt;0.01), 2 weeks (0.8±0.3 vs 5.5±1.8 ng/mL, P&lt;0.05), and 4 weeks (0.9±0.2 vs 2.0±0.4 ng/mL, P&lt;0.05). Retinal protein expression levels of HIF‐1a and angiogenic proteins, such as vascular endothelial growth factor a (VEGFa), erythroblast transformation‐specific (ETS)‐related gene (ERG), and Protein C‐ets‐1 (ETS‐1) were increased in the METH‐treated retinas. Counts of retinal arterioles and capillaries were higher in METH‐treated mice than in saline‐treated mice. Moreover, protein concentration in the vitreous humor and immunoreactivity of immunoglobulin in retina, which are measures of retinal permeability, were increased by METH treatment.ConclusionOur present data suggest that METH is associated with retinal neovascularization and hyperpermeability with increases in hypoxia, plasma norepinephrine, and HIF‐1a activation.Support or Funding InformationThis work was supported by funding from the National Institute of Health (NIH) EY025632.

An AR-ERG transcriptional signature defined by long-range chromatin interactomes in prostate cancer cells.

The aberrant activities of transcription factors such as the androgen receptor (AR) underpin prostate cancer development. While the AR cis-regulation has been extensively studied in prostate cancer, information pertaining to the spatial architecture of the AR transcriptional circuitry remains limited. In this paper, we propose a novel framework to profile long-range chromatin interactions associated with AR and its collaborative transcription factor, erythroblast transformation-specific related gene (ERG), using chromatin interaction analysis by paired-end tag (ChIA-PET). We identified ERG-associated long-range chromatin interactions as a cooperative component in the AR-associated chromatin interactome, acting in concert to achieve coordinated regulation of a subset of AR target genes. Through multifaceted functional data analysis, we found that AR-ERG interaction hub regions are characterized by distinct functional signatures, including bidirectional transcription and cotranscription factor binding. In addition, cancer-associated long noncoding RNAs were found to be connected near protein-coding genes through AR-ERG looping. Finally, we found strong enrichment of prostate cancer genome-wide association study (GWAS) single nucleotide polymorphisms (SNPs) at AR-ERG co-binding sites participating in chromatin interactions and gene regulation, suggesting GWAS target genes identified from chromatin looping data provide more biologically relevant findings than using the nearest gene approach. Taken together, our results revealed an AR-ERG-centric higher-order chromatin structure that drives coordinated gene expression in prostate cancer progression and the identification of potential target genes for therapeutic intervention.

Upregulation of centromere protein F is linked to aggressive prostate cancers.

BackgroundCentromere protein F (CENPF) is a key component of the kinetochore complex and plays a crucial role in chromosome segregation and cell cycle progression. Recent work suggests that CENPF upregulation is linked to aggressive tumor features in a variety of malignancies including prostate cancer.Materials and methodsUsing a highly annotated tissue microarray, we analyzed CENPF protein expression from a cohort of 8,298 prostatectomized patients by immunohistochemistry to study its effect on prostate-specific antigen recurrence-free survival.ResultsCENPF overexpression was found in 53% of cancers, and was linked to higher Gleason grade, advanced pathological tumor stage, accelerated cell proliferation, and lymph node metastasis (p<0.0001, each). A comparison with other key molecular features accessible through the microarray revealed strong associations between CENPF overexpression and presence of erythroblast transformation-specific (ETS)-related gene (ERG) fusion as well as phosphatase and tensin homolog deletion (p<0.0001, each). CENPF overexpression was linked to early biochemical recurrence. A subset analysis revealed that this was driven by the ERG-negative subset (p<0.0001). This was independent of established preoperative and postoperative prognostic parameters in multivariate analyses.ConclusionThe results of our study identify CENPF overexpression as an important mechanism and a potential biomarker for prostate cancer aggressiveness.

High concordance of TMPRSS-ERG fusion between primary prostate cancer and its lymph node metastases.

Approximately 50% of prostate cancer types harbor the transmembrane protease, serine 2: Erythroblast transformation-specific-related gene (ERG) fusion, resulting in oncogenic expression of the ERG transcription factor. ERG represents an attractive target for potential future anticancer therapy in advanced and metastatic prostate cancer. To better understand whether the analysis of the primary cancer is sufficient to estimate the ERG expression status of the lymph node metastases, the present study examined patterns of immunohistochemical ERG expression in a tissue microarray created from multiple primary and metastatic sites of 77 prostate cancer tissues. Among the identified tumor types, 80% were either entirely ERG-positive (38%) or ERG-negative (42%) across all (at least 9) analyzed different tumor sites. The results were heterogeneous in 20% of the tumor types and typically resulted from small ERG-negative areas within otherwise ERG-positive tumor types. Comparison of the ERG expression status in 51 primary cancer types with at least three interpretable lymph node metastases revealed an entirely identical ERG status in all tumor sites in 75% of the cases, including 16 ERG-positive and 22 ERG-negative cancer types. The remaining 13 cancer types exhibited ERG heterogeneity within the primary tumor, while all metastases had an identical (12 positive and 1 negative) ERG status. The results of the present study revealed a high degree of concordance of the ERG expression status between primary prostate cancer types and their lymph node metastases. Therefore, potential anti-ERG therapy may also be effective against lymph node metastases in the majority of cases of ERG-positive metastatic prostate cancer.

Association between pathologic factors and ERG expression in prostate cancer: finding pivotal networking.

To evaluate associations between pathologic factors and erythroblast transformation-specific (ETS)-related gene (ERG) expression in prostate cancer patients. Using next-generation sequencing, we identified target genes and regulatory networks. ERG expression in 60 radical prostatectomies was compared with pathological findings by association rule mining with the Apriori algorithm. Whole-exome and RNA sequencing were performed on three formalin-fixed, paraffin-embedded ERG-positive and negative prostate cancer samples. A network diagram identifying dominant altered genes was constructed using Cytoscape open-source bioinformatics platform and GeneMania plugin. Pathologic conditions positive for perineural invasion, apical margins, and Gleason score 3 + 4 = 7 were significantly more likely to be ERG-positive than other pathologic conditions (p = 0.0008), suggesting an association between ERG positivity, perineural invasion, apical margins, and Gleason score 3 + 4 = 7 (Firth's logistic regression: OR 42.565, 95% CI 1.670-1084.847, p = 0.0232). Results of whole-exome and RNA sequencing identified 97 somatic mutations containing common mutated genes. Regulatory network analysis identified NOTCH1, MEF2C, STAT3, LCK, CACNA2D3, PCSK7, MEF2A, PDZD2, TAB1, and ASGR1 as pivotal genes. NOTCH1 appears to function as a hub, because it had the highest node degree and betweenness. NOTCH1 staining was found 8 of 60 specimens (13%), with a significant association between ERG and NOTCH1 positivity (p = 0.001). Evaluating the association between ERG expression and pathologic factors, and identifying the regulatory network and pivotal hub may help to understand the clinical significance of ERG-positive prostate cancer.

TMPRSS2:ERG Gene Fusions in Prostate Cancer of West African Men and a Meta-Analysis of Racial Differences.

The prevalence of fusions of the transmembrane protease, serine 2, gene (TMPRSS2) with the erythroblast transformation-specific-related gene (ERG), or TMPRSS2:ERG, in prostate cancer varies by race. However, such somatic aberration and its association with prognostic factors have neither been studied in a West African population nor been systematically reviewed in the context of racial differences. We used immunohistochemistry to assess oncoprotein encoded by the ERG gene as the established surrogate of ERG fusion genes among 262 prostate cancer biopsies from the Ghana Prostate Study (2004-2006). Poisson regression with robust variance estimation provided prevalence ratios and 95% confidence intervals of ERG expression in relation to patient characteristics. We found that 47 of 262 (18%) prostate cancers were ERG-positive, and being negative for ERG staining was associated with higher Gleason score. We further conducted a systematic review and meta-analysis of TMPRSS2:ERG fusions in relation to race, Gleason score, and tumor stage, combining results from Ghana with 40 additional studies. Meta-analysis showed the prevalence of TMPRSS2:ERG fusions in prostate cancer to be highest in men of European descent (49%), followed by men of Asian (27%) and then African (25%) descent. The lower prevalence of TMPRSS2:ERG fusions in men of African descent implies that alternative genomic mechanisms might explain the disproportionately high prostate cancer burden in such populations.