Knock-down of PRAME increases retinoic acid signaling and cytotoxic drug sensitivity of Hodgkin lymphoma cells

Shedding light on PRAME expression in dysplastic nevi: a cohort study

Dysplastic nevi represent one of the least agreed-upon entities in dermatopathology despite the existence of established criteria. This study explores preferentially expressed antigen in melanoma (PRAME) in dysplastic nevi, an uncharted area. We examined 22 common melanocytic nevi (CMN), 20 cutaneous melanomas (CM), 48 low-grade dysplastic nevi (LG-DN), and 40 high-grade dysplastic nevi (HG-DN). PRAME was immunohistochemically assessed using a five-tiered system (0 to 4 +). Among CMN, 59% scored 0, 32% scored 1 + , and 9% scored 2 + . CM had score 2 + and 4 + in 11% and 89% of cases, respectively. Among LG-DN, 38% presented score 0, 31% score 1 + , 17% score 2 + , 8% score 3 + , and 6% score 4 + . Thirty per cent of HG-DN demonstrated a score 0, 30% with score 1 + , 15% score 2 + , 10% score 3 + , and 15% score 4 + . Compared to CMN and CM, LG-DN and HG-DN showed heterogeneous expression profiles of PRAME. PRAME positivity effectively distinguished HG-DN from CM with 85% specificity and 80% sensitivity (p < 0.0001). Predictive values were 87% (negative) and 76% (positive). Furthermore, a trend of increased PRAME expression from LG-DN to HG-DN was observed. However, the applicability of PRAME in the differential diagnosis of dysplastic lesions remains unclear as can yield conflicting results with morphology, which remains the primary diagnostic tool for melanocytic lesions.

Expression of Preferentially Expressed Antigen in Melanoma, a Cancer/Testis Antigen, in Carcinoma In Situ of the Urinary Tract

Carcinoma in situ (CIS) of the urinary tract comprises 1-3% of all urothelial malignancies and is often a precursor to muscle-invasive urothelial carcinoma (UC). This study aimed to examine the expression profiles of preferentially expressed antigen in melanoma (PRAME), a cancer/testis antigen, and assess its diagnostic and therapeutic applications in CIS, given that its expression in UC has been minimally studied and has not yet been analyzed in CIS. We selected consecutive patients with CIS who underwent biopsy and/or transurethral tumor resection at the Osaka Medical and Pharmaceutical University Hospital. Immunohistochemical staining for PRAME and p53 was performed. Overall, 53 patients with CIS (6 females and 47 males) were included. Notably, PRAME expression was observed in 23 of the 53 patients (43.4%), whereas it was absent in the non-neoplastic urothelial epithelium. Furthermore, no correlation was found between PRAME expression and aberrant p53 expression. Therefore, PRAME expression may serve as a useful marker for CIS of the urinary tract. Furthermore, PRAME may be a candidate for the novel therapeutic target for standard treatment-refractory CIS patients.

Single-cell analysis reveals altered tumor microenvironments of relapse- and remission-associated pediatric acute myeloid leukemia

Acute myeloid leukemia (AML) microenvironment exhibits cellular and molecular differences among various subtypes. Here, we utilize single-cell RNA sequencing (scRNA-seq) to analyze pediatric AML bone marrow (BM) samples from diagnosis (Dx), end of induction (EOI), and relapse timepoints. Analysis of Dx, EOI scRNA-seq, and TARGET AML RNA-seq datasets reveals an AML blasts-associated 7-gene signature (CLEC11A, PRAME, AZU1, NREP, ARMH1, C1QBP, TRH), which we validate on independent datasets. The analysis reveals distinct clusters of Dx relapse- and continuous complete remission (CCR)-associated AML-blasts with differential expression of genes associated with survival. At Dx, relapse-associated samples have more exhausted T cells while CCR-associated samples have more inflammatory M1 macrophages. Post-therapy EOI residual blasts overexpress fatty acid oxidation, tumor growth, and stemness genes. Also, a post-therapy T-cell cluster associated with relapse samples exhibits downregulation of MHC Class I and T-cell regulatory genes. Altogether, this study deeply characterizes pediatric AML relapse- and CCR-associated samples to provide insights into the BM microenvironment landscape.

Transcriptome Analysis of Diffuse Large B-Cell Lymphoma Cells Inducibly Expressing MyD88 L265P Mutation Identifies Upregulated CD44, LGALS3, NFKBIZ, and BATF as Downstream Targets of Oncogenic NF-κB Signaling

During innate immune responses, myeloid differentiation primary response 88 (MyD88) functions as a critical signaling adaptor protein integrating stimuli from toll-like receptors (TLR) and the interleukin-1 receptor (IL-1R) family and translates them into specific cellular outcomes. In B cells, somatic mutations in MyD88 trigger oncogenic NF-κB signaling independent of receptor stimulation, which leads to the development of B-cell malignancies. However, the exact molecular mechanisms and downstream signaling targets remain unresolved. We established an inducible system to introduce MyD88 to lymphoma cell lines and performed transcriptomic analysis (RNA-seq) to identify genes differentially expressed by MyD88 bearing the L265P oncogenic mutation. We show that MyD88L265P activates NF-κB signaling and upregulates genes that might contribute to lymphomagenesis, including CD44, LGALS3 (coding Galectin-3), NFKBIZ (coding IkBƺ), and BATF. Moreover, we demonstrate that CD44 can serve as a marker of the activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) and that CD44 expression is correlated with overall survival in DLBCL patients. Our results shed new light on the downstream outcomes of MyD88L265P oncogenic signaling that might be involved in cellular transformation and provide novel therapeutical targets.

Cancer testis antigen PRAME: An anti-cancer target with immunomodulatory potential

PReferentially expressed Antigen in Melanoma (PRAME) is a cancer testis antigen with restricted expression in somatic tissues and re‐expression in poor prognostic solid tumours. PRAME has been extensively investigated as a target for immunotherapy, however, its role in modulating the anti‐tumour immune response remains largely unknown. Here, we show that PRAME tumour expression is associated with worse survival in the TCGA breast cancer cohort, particularly in immune‐unfavourable tumours. Using direct and indirect co‐culture models, we found that PRAME overexpressing MDA‐MB‐468 breast cancer cells inhibit T cell activation and cytolytic potential, which could be partly restored by silencing of PRAME. Furthermore, silencing of PRAME reduced expression of several immune checkpoints and their ligands, including PD‐1, LAG3, PD‐L1, CD86, Gal‐9 and VISTA. Interestingly, silencing of PRAME induced cancer cell killing to levels similar to anti‐PD‐L1 atezolizumab treatment. Comprehensive analysis of soluble inflammatory mediators and cancer cell expression of immune‐related genes showed that PRAME tumour expression can suppress the expression and secretion of multiple pro‐inflammatory cytokines, and mediators of T cell activation, differentiation and cytolysis. Together, our data indicate that targeting of PRAME offers a potential, novel dual therapeutic approach to specifically target tumour cells and regulate immune activation in the tumour microenvironment.

Emerging roles of dehydrogenase/reductase member 2 (DHRS2) in the pathology of disease

Dehydrogenase/reductase member 2 (DHRS2) belongs to the short-chain dehydrogenase/reductase (SDR) family. It was initially isolated from the nuclear extract of hepatocellular carcinoma HepG2 cells and was identified as a specific cell cycle regulator. DHRS2 is a reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent carbonyl reductase and catalyzes the reduction of dicarbonyl compounds. It is also functionally active in lipid metabolism and acts as a metabolic enzyme of hormones. Recent studies have shown that DHRS2 reprograms lipid metabolism and redox homeostasis to regulate proliferation, migration, invasion, and drug resistance of cancer cells. Here, we describe the structure, organelle localization and function of DHRS2, and also highlight its roles in the pathologic progression of diseases.

Preferentially expressed antigen in melanoma as a novel diagnostic marker differentiating thymic squamous cell carcinoma from thymoma

Thymic squamous cell carcinoma (TSQCC), accounting for 70-80% of thymic carcinoma cases, is distinct from thymoma. However, differential diagnosis for type B3 thymoma is sometimes challenging, even with established markers for TSQCC, including KIT and CD5, which are expressed in ~ 80% of TSQCCs and ~ 3% of thymomas. Novel TSQCC-specific markers would facilitate precise diagnosis and optimal treatment. Herein, we found that preferentially expressed antigen in melanoma (PRAME) may be a novel TSQCC-specific diagnostic marker. We comprehensively profiled 770 immune-related mRNAs in 10 patients with TSQCC and two healthy controls, showing that PRAME and KIT were significantly upregulated in TSQCC (adjusted p values = 0.045 and 0.0011, respectively). We then examined PRAME expression in 17 TSQCCs and 116 thymomas via immunohistochemistry. All 17 (100%) TSQCCs displayed diffuse and strong PRAME expression, whereas eight of 116 (6.8%) thymomas displayed focal and weak expression (p < 0.0001). KIT and CD5 were positive in 17 (100%) and 16 (94.1%) TSQCCs, respectively, whereas one (0.9%) type B3 thymoma showed double positivity for KIT and CD5. The KIT-/CD5-positive type B3 thymoma was negative for PRAME. Thus, combinatorial evaluation of PRAME with KIT and CD5 may facilitate a more precise diagnosis of TSQCC.

Immunopeptidome screening to design An immunogenic construct against PRAME positive breast cancer; An in silico study

BACKGROUND

Metastasis is the main cause of breast cancer (BC) lethality, especially in early stages, led to improvements in therapeutic procedures. Lately, by improvements in our perception of biological processes and immune system new classes of vaccines are emerged that grant us the opportunity of designing resolute constructs against desired antigens. In the current study, we used a variety of immunoinformatics tools to design a novel cancer vaccine against Preferentially Expressed Antigen of Melanoma (PRAME), which counts as a cancer testis antigen for various human cancers including BC. The PRAME up-regulation leads to strengthen BC stem cells maintenance, drug resistance, cell survival, adaptation, and apoptosis evading in cancerous cells.

METHODS AND RESULTS

The PRAME co-expressed genes were mined and validated through BC RNA-sequencing of TCGA data. The immunodominant T-cell predicted epitopes were fused and engineered to form the vaccine. The safety, allergenicity, and immunogenic capabilities of the vaccine were confirmed by promising immunoinformatics tools. The vaccine's structure was verified to be hydrophilic in most areas through Kyte and Doolittle hydrophobicity plotting. The interactions between the designed vaccine and immune receptors of TLR4 and IL1R were confirmed by protein-protein docking after modeling its tertiary structure. Finally, codon optimization and in silico cloning were performed to guarantee better in-vivo results.

CONCLUSION

In conclusion, concerning in silico assessments' results in this study, the designed vaccine can potentially boost immune responses against PRAME, therefore may decrease BC development and metastasis. According to the mined PRAME co-expressed genes and their functional annotation, cell cycle regulation is the prime mechanism opted by this construct and its adjacent regulatory genes along boosting immune reactions.

Deletion of the mouse X-linked Prame gene causes germ cell reduction in spermatogenesis

Preferentially expressed antigen in melanoma (PRAME) is cancer/testis antigen and a transcriptional repressor, inhibiting the signaling of retinoic acid through the retinoic acid receptor (RAR) for promoting cell proliferation and preventing cell apoptosis in cancer cells. The role of PRAME in testis and germline is unknown. We report here the generation and characterization of an X-linked Prame conditional knockout (cKO) mouse. Although fertile, the testis size (p < .01) and sperm count (p < .05) of the Prame cKO mice were significantly reduced by 12% at 4 months of age compared with the Prame floxed mice. Histological, immunofluorescence with germ cell-specific markers and terminal deoxynucleotidyl transferase dUTP nick end labeling analyses of testis cross-sections at postnatal day 7 (P7), P14, P21, P35, P120, and P365 indicated a significant increase in apoptotic germ cells at P7 and P14 and an increase in abnormal seminiferous tubules at P21 and P35. Germ cells were gradually lost resulting in two different phenotypes in the Prame cKO testes: Sertoli-cell-only for some of the affected tubules in young mice (at P35) and germ cell arrest at spermatogonia stage for other affected tubules in mature mice. Both phenotypes were a consequence of disruption in RAR signaling pathway by the depletion of Prame at a different time point during the first and subsequent rounds of spermatogenesis. The results suggest that Prame plays a minor, but important role in spermatogenesis and different paralogs in the Prame gene family may be functionally and partially redundant.

PRAME promotes epithelial-to-mesenchymal transition in triple negative breast cancer

Background

The triple negative breast cancer (TNBC) paradox marks a major challenge in the treatment-decision making process. TNBC patients generally respond better to neoadjuvant chemotherapy compared to other breast cancer patients; however, they have a substantial higher risk of disease recurrence. We evaluated the expression of the tumor-associated antigen PReferentially Antigen expressed in MElanoma (PRAME) as a prognostic biomarker in breast cancer and explored its role in cell migration and invasion, key hallmarks of progressive and metastatic disease.

Methods

TCGA and GTeX datasets were interrogated to assess the expression of PRAME in relation to overall and disease-free survival. The role of PRAME in cell migration and invasion was investigated using gain- and loss-of-function TNBC cell line models.

Results

We show that PRAME promotes migration and invasion of TNBC cells through changes in expression of E-cadherin, N-cadherin, vimentin and ZEB1, core markers of an epithelial-to-mesenchymal transition. Mechanistic analysis of PRAME-overexpressing cells showed an upregulation of 11 genes (SNAI1, TCF4, TWIST1, FOXC2, IL1RN, MMP2, SOX10, WNT11, MMP3, PDGFRB, and JAG1) and downregulation of 2 genes (BMP7 and TSPAN13). Gene ontology analyses revealed enrichment of genes that are dysregulated in ovarian and esophageal cancer and are involved in transcription and apoptosis. In line with this, interrogation of TCGA and GTEx data demonstrated an increased PRAME expression in ovarian and esophageal tumor tissues in addition to breast tumors where it is associated with worse survival.

Conclusions

Our findings indicate that PRAME plays a tumor-promoting role in triple negative breast cancer by increasing cancer cell motility through EMT-gene reprogramming. Therefore, PRAME could serve as a prognostic biomarker and/or therapeutic target in TNBC.

Blood Gene Expression Profile Predicts Response to Antipsychotics

Antipsychotic drugs are one of the largest types of prescribed drugs and have large inter-individual differences in efficacy, but there is no methodology to predict their clinical effect. Here we show a four-gene blood expression profile to predict the response to antipsychotics in schizophrenia patients before treatment. We sequenced total mRNA from blood samples of antipsychotic naïve patients who, after 3 months of treatment, were in the top 40% with the best response (15 patients) and in the bottom 40% with the worst response (15 patients) according to the Brief Psychiatric Rating Scale (BPRS). We characterized the transcriptome before treatment of these 30 patients and found 130 genes with significant differential expression (P_adj value < 0.01) associated with clinical response. Then, we used Random Forests, an ensemble learning method for classification and regression, to obtain a list of predictor genes. The expression of four genes can predict the response to antipsychotic medication with a cross-validation accuracy estimation of 0.83 and an area under the curve of 0.97 using a logistic regression. We anticipate that this approach is a gateway to select the specific antipsychotic that will produce the best response to treatment for each specific patient.

Inhibitor of vasculogenic mimicry restores sensitivity of resistant melanoma cells to DNA-damaging agents

The increasing incidence of melanoma makes this cancer an important public health problem. Therapeutic resistance is still a major obstacle to the therapy of patients with metastatic melanomas. The aim of this study was to develop the melanoma cell line resistant to DNA-alkylating agents and to elucidate the mechanisms involved in acquired drug resistance. We established a unique melanoma subline Mel MeR resistant to DNA-alkylating drug aranoza by continuous stepwise selection of the Mel Me/WT cell line with increasing concentrations of this drug. Mel MeR cells were also cross-resistant to streptozotocin or cisplatin. Here, we show that aranoza-resistant melanoma cells modulate the ABC transporter activity, upregulate the expression of PRAME, adopt a vascular-related phenotype and engage in vasculogenic mimicry. LCS1269, a vasculogenic mimicry low-molecular-weight inhibitor, reverses the sensitivity of resistant melanoma cells to DNA-damaging agents. In this study, we provide experimental evidence that LCS1269 might be considered as a new potential anticancer agent capable of overcoming multidrug resistance for DNA-damaging agents in melanoma.

PRAME expression and promoter hypomethylation in epithelial ovarian cancer

PRAME is a cancer-testis antigen (CTA) and potential immuno-therapeutic target, but has not been well-studied in epithelial ovarian cancer (EOC) or its high grade serous (HGSC) subtype. Compared to normal ovary, PRAME expression was significantly increased most EOC, regardless of stage and grade. Interestingly, PRAME mRNA expression was associated with improved survival in the HGSC subtype. The PRAME locus was a frequent target for copy number alterations (CNA) in HGSC but most changes were heterozygous losses, indicating that elevated PRAME expression is not typically due to CNA. In contrast, PRAME promoter DNA hypomethylation was very common in EOC and HGSC and correlated with increased PRAME expression. PRAME expression and promoter hypomethylation both correlated with LINE-1 hypomethylation, a biomarker of global DNA hypomethylation. Pharmacologic or genetic disruption of DNA methyltransferase (DNMT) enzymes activated PRAME expression in EOC cells. Immunohistochemistry (IHC) of PRAME in EOC revealed frequent, but low level, protein expression, and expression was confined to epithelial cells and localized to the cytoplasm. Cytoplasmic PRAME expression was positively associated with PRAME mRNA expression and negatively associated with promoter methylation, but the latter correlation was not statistically significant. PRAME protein expression did not correlate with EOC clinicopathology or survival. In summary, PRAME is frequently expressed in EOC at the mRNA and protein levels, and DNA methylation is a key mechanism regulating its expression. These data support PRAME as an immunotherapy target in EOC, and suggest treatment with DNMT inhibitors as a means to augment PRAME immunotherapy.

Candidate genes and pathways downstream of PAX8 involved in ovarian high-grade serous carcinoma

Understanding the biology and molecular pathogenesis of ovarian epithelial cancer (EOC) is key to developing improved diagnostic and prognostic indicators and effective therapies. Although research has traditionally focused on the hypothesis that high-grade serous carcinoma (HGSC) arises from the ovarian surface epithelium (OSE), recent studies suggest that additional sites of origin exist and a substantial proportion of cases may arise from precursor lesions located in the Fallopian tubal epithelium (FTE). In FTE cells, the transcription factor PAX8 is a marker of the secretory cell lineage and its expression is retained in 96% of EOC. We have recently reported that PAX8 is involved in the tumorigenic phenotype of ovarian cancer cells. In this study, to uncover genes and pathways downstream of PAX8 involved in ovarian carcinoma we have determined the molecular profiles of ovarian cancer cells and in parallel of Fallopian tube epithelial cells by means of a silencing approach followed by an RNA-seq analysis. Interestingly, we highlighted the involvement of pathways like WNT signaling, epithelial-mesenchymal transition, p53 and apoptosis. We believe that our analysis has led to the identification of candidate genes and pathways regulated by PAX8 that could be additional targets for the therapy of ovarian carcinoma.

Pharmacological restoration and therapeutic targeting of the B-cell phenotype in classical Hodgkin lymphoma

A pharmacological screening identified compounds that reactivate B-cell–specific gene expression in cHL cell lines. B-cell phenotype-restoring drug combinations render cHL cell lines susceptible to B-NHL–reminiscent targeted therapies.

Prognostic Biomarkers for Hodgkin Lymphoma

The prognosis of patients with classical Hodgkin lymphoma following chemo- and radiotherapy has been excellent during the last 4 decades. However, the development of secondary malignancies is of major concern. Therefore, the reduction of radiotherapy application is a major objective of ongoing clinical trials. De-escalation of treatment may increase the risk of relapses and thus may lead to reappearance of prognostic factors. Prognostic biomarkers might help to identify patients who are at increased risk of relapse. This review summarizes the current knowledge about potential prognostic biomarkers for patients with classical Hodgkin lymphoma.

Impact of Preferentially Expressed Antigen of Melanoma on the Prognosis of Hepatocellular Carcinoma

BACKGROUND

Retinoids, vitamin A and its derivatives, have an antitumor effect on hepatocellular carcinoma (HCC). The function of retinoids is exerted by the complex of retinoic acid (RA) with the heterodimer of retinoid X receptor and the RA receptor. The preferentially expressed antigen of melanoma (PRAME) acts as a dominant repressor of RA signaling by binding to the complex. The significance of PRAME on the prognosis of HCC remains to be clarified.

METHODS

PRAME mRNA expression was examined by quantitative real-time polymerase chain reaction in both tumor and non-tumor tissues of 100 HCC patients who received surgical resection. The effect of PRAME knockdown on DR5-mediated RA transcriptional activity was examined.

RESULTS

In tumor tissues, there were significant associations among PRAME expression, clinical stage, tumor markers, and tumor numbers. In non-tumor tissues, there were significant associations among PRAME expression, overall survival, and disease-free survival. The knockdown of PRAME caused no reduction in DR5-mediated transcriptional activity of RA, suggesting that PRAME acts via other mechanisms than the DR5 RA-responsive elements.

CONCLUSION

Our findings indicate that PRAME expression is a novel prognostic marker in HCC patients.

Curcuma Contra Cancer? Curcumin and Hodgkin's Lymphoma

Curcumin, a phytochemical isolated from curcuma plants which are used as coloring ingredient for the preparation of curry powder, has several activities which suggest that it might be an interesting drug for the treatment or prevention of cancer. Curcumin targets different pathways which are involved in the malignant phenotype of tumor cells, including the nuclear factor kappa B (NFKB) pathway. This pathway is deregulated in multiple tumor entities, including Hodgkin’s lymphoma (HL). Indeed, curcumin can inhibit growth of HL cell lines and increases the sensitivity of these cells for cisplatin. In this review we summarize curcumin activities with special focus on possible activities against HL cells.