PEG10 promotes human breast cancer cell proliferation, migration and invasion

Abrogation of USP9X Is a Potential Strategy to Decrease PEG10 Levels and Impede Tumor Progression in Cutaneous T-Cell Lymphoma

Advanced-stage cutaneous T-cell lymphomas (CTCLs) are notorious for their highly aggressive behavior, resistance to conventional treatments, and poor prognosis, particularly when large-cell transformation occurs. PEG10 has been recently proposed as a potent driver for large-cell transformation in CTCL. However, the targeting of PEG10 continues to present a formidable clinical challenge that has yet to be addressed. In this study, we report an important post-translational regulatory mechanism of PEG10 in CTCL. USP9X, a deubiquitinase, interacted with and deubiquitinated PEG10, thereby stabilizing PEG10. Knockdown of USP9X or pharmacological targeting of USP9X resulted in a prominent downregulation of PEG10 and its downstream pathway in CTCL. Moreover, USP9X inhibition conferred tumor cell growth disadvantage and enhanced apoptosis in vitro, an effect that occurred in part through its regulation on PEG10. Furthermore, we demonstrated that inhibition of USP9X obviously restrained CTCL tumor growth in vivo and that high expression of USP9X is associated with poor survival in patients with CTCL. Collectively, our findings uncover USP9X as a key post-translational regulator in the stabilization of PEG10 and suggest that targeting PEG10 stabilization through USP9X inhibition may represent a promising therapeutic strategy for advanced-stage CTCL.

Paternal Expressed Gene 10 (PEG10) is decreased in early-onset preeclampsia

BACKGROUND

Preeclampsia is a severe complication of pregnancy which is attributed to placental dysfunction. The retrotransposon, Paternal Expressed Gene 10 (PEG10) harbours critical placental functions pertaining to placental trophoblast cells. Limited evidence exists on whether PEG10 is involved in preeclampsia pathogenesis. This study characterised the expression and regulation of PEG10 in placentas from patients with early-onset preeclampsia compared to gestation-matched controls.

METHODS

PEG10 expression was measured in plasma and placentas collected from patients with early-onset preeclampsia (< 34 weeks') and gestation-matched controls using ELISA (protein) and RT-qPCR (mRNA). First-trimester human trophoblast stem cells (hTSCs) were used for in vitro studies. PEG10 expression was measured during hTSC differentiation and hTSC exposure to hypoxia (1% O₂) and inflammatory cytokines (IL-6 and TNFα) using RT-qPCR. Functional studies used PEG10 siRNA to measure the effect of reduced PEG10 on canonical TGF-[Formula: see text] signalling and proliferation using luciferase and xCELLigence assays, respectively.

RESULTS

PEG10 mRNA expression was significantly reduced in placentas from patients with early-onset preeclampsia (< 34 weeks' gestation) relative to controls (p = 0.04, n = 78 vs n = 18 controls). PEG10 protein expression was also reduced in preeclamptic placentas (p = 0.03, n = 5 vs n = 5 controls, blinded assessment of immunohistochemical staining), but neither PEG10 mRNA nor protein could be detected in maternal circulation. PEG10 was most highly expressed in hTSCs, and its expression was reduced as hTSCs differentiated into syncytiotrophoblasts (p < 0.0001) and extravillous trophoblasts (p < 0.001). Trophoblast differentiation was not altered when hTSCs were treated with PEG10 siRNA (n = 5 vs n = 5 controls). PEG10 was significantly reduced in hTSCs exposed to hypoxia (p < 0.01). PEG10 was also reduced in hTSCs treated with the inflammatory cytokine TNF [Formula: see text] (p < 0.01), but not IL-6. PEG10 knocked down (siRNA) in hTSCs showed reduced activation of the canonical TGF-β signalling effector, the SMAD binding element (p < 0.05) relative to controls. PEG10 knockdown in hTSCs however was not associated with any significant alterations in proliferation.

CONCLUSIONS

Placental PEG10 is reduced in patients with early-onset preeclampsia. In vitro studies suggest that hypoxia and inflammation may contribute to PEG10 downregulation. Reduced PEG10 alters canonical TGF-[Formula: see text] signalling, and thus may be involved in trophoblast dysfunction associated with this pathway.

Bioinformatics and network biology approach to identifying type 2 diabetes genes and pathways that influence the progression of breast cancer

Breast cancer is the second most prevalent malignancy affecting women. Postmenopausal women breast tumor is one of the top causes of death in women, accounting for 23% of cancer cases. Type 2 diabetes, a worldwide pandemic, has been connected to a heightened risk of several malignancies, although its association with breast cancer is still uncertain. In comparison to non-diabetic women, women with T2DM had a 23% elevated likelihood of developing breast cancer. It is difficult to determine causative or genetic susceptibility that connect T2DM and breast cancer. We created a large-scale network-based quantitative approach employing unbiased methods to discover abnormally amplified genes in both T2DM and breast cancer, to solve these issues. We performed transcriptome analysis to uncover identical genetic biomarkers and pathways to clarify the connection between T2DM and breast cancer patients. In this study, two RNA-seq datasets (GSE103001 and GSE86468) from the Gene Expression Omnibus (GEO) are used to identify mutually differentially expressed genes (DEGs) for breast cancer and T2DM, as well as common pathways and prospective medicines. Firstly, 45 shared genes (30 upregulated and 15 downregulated) between T2D and breast cancer were detected. We employed gene ontology and pathway enrichment to characterize prevalent DEGs' molecular processes and signal transduction pathways and observed that T2DM has certain connections to the progression of breast cancer. Using several computational and statistical approaches, we created a protein-protein interactions (PPI) network and revealed hub genes. These hub genes can be potential biomarkers, which may also lead to new therapeutic strategies for investigated diseases. We conducted TF-gene interactions, gene-microRNA interactions, protein-drug interactions, and gene-disease associations to find potential connections between T2DM and breast cancer pathologies. We assume that the potential drugs that emerged from this study could be useful therapeutic values. Researchers, doctors, biotechnologists, and many others may benefit from this research.

The functional role of circular RNAs in the pathogenesis of retinoblastoma: a new potential biomarker and therapeutic target?

Retinoblastoma (RB) is a common cancer in infants and children. It is a curable disease; however, a delayed diagnosis or treatment makes the treatment difficult. Genetic mutations have a central role in the pathogenesis of RB. Genetic materials such as RNAs (coding and non-coding RNAs) are also involved in the progression of the tumor. Circular RNA (circRNA) is the most recently identified RNA and is involved in regulating gene expression mainly through "microRNA sponges". The dysregulation of circRNAs has been observed in several diseases and tumors. Also, various studies have shown that circRNAs expression is changed in RB tissues. Due to their role in the pathogenesis of the disease, circRNAs might be helpful as a diagnostic or prognostic biomarker in patients with RB. In addition, circRNAs could be a suitable therapeutic target to treat RB in a targeted therapy approach.

Cellular Transcriptomics of Carboplatin Resistance in a Metastatic Canine Osteosarcoma Cell Line

Osteosarcoma prognosis has remained unchanged for the past three decades. In both humans and canines, treatment is limited to excision, radiation, and chemotherapy. Chemoresistance is the primary cause of treatment failure, and the trajectory of tumor evolution while under selective pressure from treatment is thought to be the major contributing factor in both species. We sought to understand the nature of platinum-based chemotherapy resistance by investigating cells that were subjected to repeated treatment and recovery cycles with increased carboplatin concentrations. Three HMPOS-derived cell lines, two resistant and one naïve, underwent single-cell RNA sequencing to examine transcriptomic perturbation and identify pathways leading to resistance and phenotypic changes. We identified the mechanisms of acquired chemoresistance and inferred the induced cellular trajectory that evolved with repeated exposure. The gene expression patterns indicated that acquired chemoresistance was strongly associated with a process similar to epithelial–mesenchymal transition (EMT), a phenomenon associated with the acquisition of migratory and invasive properties associated with metastatic disease. We conclude that the observed trajectory of tumor adaptability is directly correlated with chemoresistance and the phase of the EMT-like phenotype is directly affected by the level of chemoresistance. We infer that the EMT-like phenotype is a critical component of tumor evolution under treatment pressure and is vital to understanding the mechanisms of chemoresistance and to improving osteosarcoma prognosis.

Identification of a neural development gene expression signature in colon cancer stem cells reveals a role for EGR2 in tumorigenesis

Recent evidence demonstrates that colon cancer stem cells (CSCs) can generate neurons that synapse with tumor innervating fibers required for tumorigenesis and disease progression. Greater understanding of the mechanisms that regulate CSC driven tumor neurogenesis may therefore lead to more effective treatments. RNA-sequencing analyses of ALDHPositive CSCs from colon cancer patient-derived organoids (PDOs) and xenografts (PDXs) showed CSCs to be enriched for neural development genes. Functional analyses of genes differentially expressed in CSCs from PDO and PDX models demonstrated the neural crest stem cell (NCSC) regulator EGR2 to be required for tumor growth and to control expression of homebox superfamily embryonic master transcriptional regulator HOX genes and the neural stem cell and master cell fate regulator SOX2. These data support CSCs as the source of tumor neurogenesis and suggest that targeting EGR2 may provide a therapeutic differentiation strategy to eliminate CSCs and block nervous system driven disease progression.

A 16-gene signature associated with homologous recombination deficiency for prognosis prediction in patients with triple-negative breast cancer

Homologous recombination deficiency (HRD) commonly occurs in breast cancer, which is the second cause of cancer death in women with a high rate of relapse and poor outcomes. Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Thus, we aim to develop a prognostic signature based on HRD expecting to help improve outcomes in TNBC. The Cancer Genome Atlas (TCGA)–TNBC cohort was divided into the training set and the testing set randomly. Sixteen genes were filtered from the prognostic HRD-associated genes to establish a prognostic model in the training set. Patients were divided into high-risk and low-risk groups based on the median value of the risk score. Prognosis analysis showed that the high-risk group was associated with a worse prognosis in the training set, the testing set, the entire TCGA–TNBC cohort, and the METABRIC–TNBC cohort. The time-dependent receiver operating characteristic curve showed that our model had very good accuracy in the prediction of 1–5-year overall survival in the TCGA–TNBC cohort. Besides, a comparison of the area under curve value and C-index between our model and four published models showed that our model had the best predictive efficiency compared to other models. Subsequently, a nomogram was established. Finally, our finding also indicated that our model was associated with immunoregulation in TNBC and had the potential to be the target for TNBC treatment. Therefore, our findings not only provided a new strategy in the personalized prognosis management of TNBC but also offered new insight into precision treatment in TNBC.

Gag-like proteins: Novel mediators of prenatal alcohol exposure in neural development

Background

We previously showed that ethanol did not kill fetal neural stem cells (NSCs), but that their numbers nevertheless are decreased due to aberrant maturation and loss of self‐renewal. To identify mechanisms that mediate this loss of NSCs, we focused on a family of Gag‐like proteins (GLPs), derived from retroviral gene remnants within mammalian genomes. GLPs are important for fetal development, though their role in brain development is virtually unexplored. Moreover, GLPs may be transferred between cells in extracellular vesicles (EVs) and thereby transfer environmental adaptations between cells. We hypothesized that GLPs may mediate some effects of ethanol in NSCs.

Methods

Sex‐segregated male and female fetal murine cortical NSCs, cultured ex vivo as nonadherent neurospheres, were exposed to a dose range of ethanol and to mitogen‐withdrawal‐induced differentiation. We used siRNAs to assess the effects of NSC‐expressed GLP knockdown on growth, survival, and maturation and in silico GLP knockout, in an in vivo single‐cell RNA‐sequencing dataset, to identify GLP‐mediated developmental pathways that were also ethanol‐sensitive.

Results

PEG10 isoform‐1, isoform‐2, and PNMA2 were identified as dominant GLP species in both NSCs and their EVs. Ethanol‐exposed NSCs exhibited significantly elevated PEG10 isoform‐2 and PNMA2 protein during differentiation. Both PEG10 and PNMA2 were mediated apoptosis resistance and additionally, PEG10 promoted neuronal and astrocyte lineage maturation. Neither GLP influenced metabolism nor cell cycle in NSCs. Virtual PEG10 and PNMA2 knockout identified gene transcription regulation and ubiquitin‐ligation processes as candidate mediators of GLP‐linked prenatal alcohol effects.

Conclusions

Collectively, GLPs present in NSCs and their EVs may confer apoptosis resistance within the NSC niche and contribute to the abnormal maturation induced by ethanol.

Evolutionarily conservative and non-conservative regulatory networks during primate interneuron development revealed by single-cell RNA and ATAC sequencing

The differences in size and function between primate and rodent brains, and the association of disturbed excitatory/inhibitory balance with many neurodevelopmental disorders highlight the importance to study primate ganglionic eminences (GEs) development. Here we used single-cell RNA and ATAC sequencing to characterize the emergence of cell diversity in monkey and human GEs where most striatal and cortical interneurons are generated. We identified regional and temporal diversity among progenitor cells which give rise to a variety of interneurons. These cells are specified within the primate GEs by well conserved gene regulatory networks, similar to those identified in mice. However, we detected, in human, several novel regulatory pathways or factors involved in the specification and migration of interneurons. Importantly, comparison of progenitors between our human and published mouse GE datasets led to the discovery and confirmation of outer radial glial cells in GEs in human cortex. Our findings reveal both evolutionarily conservative and nonconservative regulatory networks in primate GEs, which may contribute to their larger brain sizes and more complex neural networks compared with mouse.

Cellular architecture of human brain metastases

Brain metastasis (BrM) is the most common form of brain cancer, characterized by neurologic disability and an abysmal prognosis. Unfortunately, our understanding of the biology underlying human BrMs remains rudimentary. Here, we present an integrative analysis of >100,000 malignant and non-malignant cells from 15 human parenchymal BrMs, generated by single-cell transcriptomics, mass cytometry, and complemented with mouse model- and in silico approaches. We interrogated the composition of BrM niches, molecularly defined the blood-tumor interface, and revealed stromal immunosuppressive states enriched with infiltrated T cells and macrophages. Specific single-cell interrogation of metastatic tumor cells provides a framework of 8 functional cell programs that coexist or anticorrelate. Collectively, these programs delineate two functional BrM archetypes, one proliferative and the other inflammatory, that are evidently shaped through tumor-immune interactions. Our resource provides a foundation to understand the molecular basis of BrM in patients with tumor cell-intrinsic and host environmental traits.

Transcriptional regulator CTR9 promotes hepatocellular carcinoma progression and metastasis via increasing PEG10 transcriptional activity

Cln Three Requiring 9 (CTR9), a scaffold protein of the polymerase-associated factor-1 (PAF1) complex (PAF1c), is primarily localized in the nucleus of cells. Recent studies show that CTR9 plays essential roles in the development of various human cancers and their occurrence; however, its regulatory roles and precise mechanisms in hepatocellular carcinoma (HCC) remain unclear. In this study, we investigated the roles of CTR9 using in vitro assays and a xenograft mouse model. We found that CTR9 protein is upregulated in tumor tissues from HCC patients. Knockdown of CTR9 substantially reduced HCC cell proliferation, invasion, and migration, whereas its overexpression promoted these activities. In addition, in vitro results revealed that CTR9 silencing dramatically increased cell cycle regulators, p21 and p27, but markedly decreased matrix metalloproteinases, MMP2 and MMP9, with these outcomes reversed upon CTR9 overexpression. Furthermore, the underlying molecular mechanism suggests that CTR9 promoted the oncogene paternally expressed gene 10 (PEG10) transcription via its promoter region. Finally, the oncogenic roles of CTR9 were confirmed in a xenograft mouse model. This study confirms that CTR9, an oncoprotein that promotes HCC cell proliferation, invasion, and migration, increases tumor growth in a xenograft mouse model. CTR9 could be a novel therapeutic target. Further investigation is warranted to verify CTR9 potential in novel therapies for HCC.

Multi‑faceted role of cancer‑associated adipocytes in the tumor microenvironment (Review)

Adipocytes are a type of stromal cell found in numerous different tissues that serve an active role in the tumor microenvironment. Cancer-associated adipocytes (CAAs) display a malignant phenotype and are found at the invasive tumor front, which mediates the crosstalk network between adipocytes (the precursor cells that will become cancer-associated adipocytes in the future) and cancer cells. The present review covers the mechanisms of adipocytes in the development of cancer, including metabolic reprogramming, chemotherapy resistance and adipokine regulation. Furthermore, the potential mechanisms involved in the adipocyte-cancer cell cycle in various types of cancer, including breast, ovarian, colon and rectal cancer, are discussed. Deciphering the complex network of CAA-cancer cell crosstalk will provide insights into tumor biology and optimize therapeutic strategies.

Circ_0075804 promotes the malignant behaviors of retinoblastoma cells by binding to miR-138-5p to induce PEG10 expression

BACKGROUND

It has been gradually recognized that circular RNAs (circRNAs) are important modulators in multiple malignancies. Here, we analyzed the function of circ_0075804 and explored its associated mechanism in regulating retinoblastoma (RB) progression.

METHODS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were utilized to measure RNA and protein expression, respectively. Cell proliferation was analyzed by Cell counting kit-8 (CCK8) assay and 5-Ethynyl-2'-deoxyuridine (EdU) assay. Cell apoptosis was assessed by flow cytometry. Cell migration and invasion abilities were analyzed by wound healing assay and transwell invasion assay. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were applied to verify intermolecular target relations. Xenograft tumor model was used to analyze the role of circ_0075804 in tumor growth in vivo.

RESULTS

Circ_0075804 expression was markedly up-regulated in RB tissues and cell lines. Circ_0075804 knockdown restrained the proliferation, migration and invasion whereas promoted the apoptosis of RB cells. Circ_0075804 acted as a molecular sponge for microRNA-138-5p (miR-138-5p), and circ_0075804 silencing-induced effects were partly reversed by miR-138-5p knockdown in RB cells. MiR-138-5p interacted with the 3' untranslated region (3'UTR) of paternally expressed 10 (PEG10). Circ_0075804 positively regulated PEG10 level by sponging miR-138-5p in RB cells. PEG10 overexpression largely overturned miR-138-5p overexpression-mediated effects in RB cells. Circ_0075804 knockdown blocked xenograft tumor growth in vivo.

CONCLUSION

Circ_0075804 promoted RB progression via miR-138-5p-dependent regulation of PEG10, which provided new insight in RB therapy.

Periconceptional Maternal Diet Characterized by High Glycemic Loading Is Associated with Offspring Behavior in NEST

Maternal periconceptional diets have known associations with proper offspring neurodevelopment. Mechanisms for such associations include improper energy/nutrient balances between mother and fetus, as well as altered offspring epigenetics during development due to maternal nutrient and inflammatory status. Using a comprehensive food frequency questionnaire and assessing offspring temperament with the Infant-Toddler Social and Emotional Assessment (n = 325, mean age = 13.9 months), we sought to test whether a maternal periconceptional diet characterized by high glycemic loading (MGL) would affect offspring temperament using adjusted ordinal regression. After limiting false discovery to 10%, offspring born to mothers in tertile 3 of glycemic loading (referent = tertile 1) were more likely to be in the next tertile of anxiety [OR (95% CI) = 4.51 (1.88-11.07)] and inhibition-related behaviors [OR (95% CI) = 3.42 (1.49-7.96)]. Male offspring were more likely to exhibit impulsive [OR (95% CI) = 5.55 (1.76-18.33)], anxiety [OR (95% CI) = 4.41 (1.33-15.30)], sleep dysregulation [OR (95% CI) = 4.14 (1.34-13.16)], empathy [6.68 (1.95-24.40)], and maladaptive behaviors [OR (95% CI) = 9.86 (2.81-37.18)], while females were more likely to exhibit increased anxiety-related behaviors [OR (95% CI) = 15.02 (3.14-84.27)]. These associations persisted when concurrently modeled with the maternal-Mediterranean dietary pattern. In a subset (n = 142), we also found MGL associated with increased mean methylation of the imprint control region of SGCE/PEG10. In conclusion, these findings highlight the importance of maternal dietary patterns on offspring neurodevelopment, offering avenues for prevention options for mothers.

A novel 13 RNA binding proteins (RBPs) signature could predict prostate cancer biochemical recurrence

BACKGROUND

Cancer precision medicine requires biomarkers or signatures to predict prognosis and therapeutic benefits. Driven by this, we established a biochemical recurrence (BCR) predictive model for prostate cancer (PCA) patients based on RNA-binding proteins (RBPs).

METHODS

RNA-sequencing and corresponding clinicopathological data were downloaded from the Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database. Univariate COX, LASSO and multivariate COX regression analyses were carried out to develop the BCR predictive riskScore model. Survival analysis, ROC curve, independent prognostic analysis, nomogram were also performed to evaluate this signature internally and externally.

RESULTS

A total of 13 RBPs including TRMT1L, WBP4, MBNL3, SMAD9, NSUN7, ENG9, PIWIL4, PEG10, CSDC2, HELZ2, CELF2, YBX2 and ESRP2 were eventually identified as BCR-related hub biomarkers and utilized to establish a riskScore. Further analysis including external and internal verification indicated that the patients with high riskScores had shorter time to BCR compared to those with low riskScores in both TCGA and GSE116918. The area under the curve (AUC) of the time-dependent receiver operator characteristic curve (ROC) of the predictive model exhibited a good predictive performance. The signature was also proven to be a valuable independent prognostic factor (all P < 0.05). We also established a nomogram based on the 13 RBPs to visualize the relationships between individual predictors and 1-, 3- and 5-year BCR for PCA.

CONCLUSIONS

Our results successfully screened out 13 RBPs as a robust BCR-predictive signature in PCA by external and internal verification, helping clinician predict patients' cancer progression status and promoting the specific individualized treatment than original clinical parameters.

Integrative analysis of transcriptional profile reveals LINC00052 as a suppressor of breast cancer cell migration

BACKGROUND

Long-non-coding RNAs, a class of transcripts with lengths > 200 nt, play key roles in tumour progression. Previous reports revealed that LINC00052 (long intergenic non-coding RNA 00052) was strongly downregulated during breast cancer multicellular spheroids formation and suggested a role in cell migration and oxidative metabolism.

OBJECTIVE

To examine the function of LINC00052 in MCF-7 breast cancer cells.

METHODS

Loss-of-function studies were performed to evaluate LINC00052 role on MCF-7 breast cancer cells. Microarray expression assays were performed to determine genes and cellular functions modified after LINC00052 knockdown. Next, the impact of LINC00052 depletion on MCF-7 cell respiration and migration was evaluated.

RESULTS

1,081 genes were differentially expressed upon LINC00052 inhibition. Gene set enrichment analysis, Gene Ontology and Key Pathway Advisor analysis showed that signalling networks related to cell migration and oxidative phosphorylation were enriched. However, whereas LINC00052 knockdown in MCF-7 cells revealed marginal difference in oxygen consumption rates when compared with control cells, LINC00052 inhibition enhanced cell migration in vitro and in vivo, as observed using a Zebrafish embryo xenotransplant model.

CONCLUSION

Our data show that LINC00052 modulates MCF-7 cell migration. Genome-wide microarray experiments suggest that cancer cell migration is affected by LINC00052 through cytoskeleton modulation and Notch/β-catenin/NF-κB signalling pathways.

Differential Expression of PEG10 Contributes to Aggressive Disease in Early Versus Late-Onset Colorectal Cancer

BACKGROUND

Colorectal cancer is a leading cause of cancer-related death. Early onset colorectal cancer (age ≤45 y) is increasing and associated with advanced disease. Although distinct molecular subtypes of colorectal cancer have been characterized, it is unclear whether age-related molecular differences exist.

OBJECTIVE

We sought to identify differences in gene expression between early and late-onset (age ≥65 y) colorectal cancer.

DESIGN

We performed a review of our institution's colorectal cancer registry and identified patients with colorectal cancer with tissue specimens available for analysis. We used the Cancer Genome Atlas to initially identify differences in gene expression between early and late-onset colorectal cancer. In vitro experiments were performed on 2 colorectal cancer cell lines.

SETTINGS

The study was conducted at a tertiary medical center.

PATIENTS

Patients with early onset (n = 28) or late onset (age ≥65 y; n = 38) at time of diagnosis were included.

MAIN OUTCOME MEASURES

The primary outcome was differential gene expression in patients with early versus late-onset colorectal cancer. The secondary outcome was patient mortality.

RESULTS

Seven genes had increased expression in younger patients using The Cancer Genome Atlas. Only PEG10 was sufficiently expressed with quantitative polymerase chain reaction and had increased expression in our early onset group. Multivariable linear regression analysis identified age as a significant independent predictor of increased PEG10 expression. Outcomes data from The Cancer Genome Atlas suggests that PEG10 is associated with poor overall survival. In vitro studies in HCT-116 and HT-29 cell lines showed that PEG10 contributes to cellular proliferation and invasion in colorectal cancer.

LIMITATIONS

Tissue samples were from formalin-fixed, paraffin-embedded sections. Many patients did not have mutational status for review.

CONCLUSIONS

PEG10 is differentially expressed in early onset colorectal cancer and may functionally contribute to tumor cell proliferation and invasion. An increase in PEG10 expression correlates with decreased overall survival. See Video Abstract at http://links.lww.com/DCR/B343. LA EXPRESIÓN DIFERENCIAL DE PEG10 CONTRIBUYE A LA ENFERMEDAD AGRESIVA EN EL CÁNCER COLORRECTAL DE INICIO TEMPRANO VERSUS INICIO TARDÍO: El cáncer colorrectal es una de las principales causas de muerte relacionada con el cáncer. El cáncer colorrectal de inicio temprano (edad ≤45 años) está en aumento y asociado con enfermedad avanzada. Aunque se han caracterizado distintos subtipos moleculares del cáncer colorrectal, no está claro si existen diferencias moleculares relacionadas con la edad.Se buscó identificar diferencias en la expresión génica entre el cáncer colorrectal de inicio temprano y tardío (edad ≥ 65 años).Realizamos una revisión del registro de cáncer colorrectal de nuestra institución e identificamos pacientes con cáncer colorrectal con muestras de tejido disponibles para su análisis. Utilizamos el Atlas del Genoma del Cáncer para identificar inicialmente las diferencias en la expresión génica entre el cáncer colorrectal de inicio temprano y de inicio tardío. Se realizaron experimentos in vitro en dos líneas celulares de cáncer colorrectal.El estudio se realizó en un centro médico de tercer nivel.Se incluyeron pacientes con inicio temprano (n = 28) e inicio tardío (edad ≥65 años, n = 38) al momento del diagnóstico.El resultado primario fue la expresión diferencial de genes en pacientes con cáncer colorrectal de inicio temprano versus tardío. El resultado secundario fue la mortalidad de los pacientes.Siete genes aumentaron su expresión en pacientes más jóvenes usando el Atlas del Genoma del Cáncer. Solo PEG10 se expresó suficientemente con la reacción en cadena de la polimerasa cuantitativa y tuvo una mayor expresión en nuestro grupo de inicio temprano. El análisis de regresión lineal multivariable identificó la edad como un predictor independiente significativo del aumento de la expresión de PEG10. Los datos de resultados de el Atlas del Genoma del Cáncer sugieren que PEG10 está asociado con una pobre supervivencia general. Los estudios in vitro en líneas celulares HCT-116 y HT-29 mostraron que PEG10 contribuye a la proliferación e invasión celular en el cáncer colorrectal.Las muestras de tejido fueron de portaobjetos embebidos en parafina fijados con formalina. Muchos pacientes no tenían el estado de mutación para su revisión.El PEG10 se expresa diferencialmente en el cáncer colorrectal de inicio temprano y puede contribuir funcionalmente a la proliferación e invasión de células tumorales. El aumento en la expresión de PEG10 se correlaciona con la disminución de la supervivencia general. Consulte Video Resumen en http://links.lww.com/DCR/B343.

Long Non-Coding RNA Paternally Expressed Imprinted Gene 10 (PEG10) Elevates Diffuse Large B-Cell Lymphoma Progression by Regulating Kinesin Family Member 2A (KIF2A) via Targeting MiR-101-3p

Background

Diffuse large B-cell lymphoma (DLBCL) is a common malignant tumor in the immune system with high mortality. We investigated the functional effects of long non-coding RNA paternally expressed imprinted gene 10 (PEG10) on DLBCL progression.

Material/Methods

Real-time quantitative polymerase chain reaction was used to measure the level of PEG10, kinesin family member 2A (KIF2A) and microRNA-101-3p (miR-101-3p) in DLBCL tissues and cell lines. The relative protein level was detected by western blot analysis. The biological behaviors including cell proliferation, apoptosis, migration, and invasion were determined by MTT assay, flow cytometry analysis, and Transwell assays, respectively. Bioinformatics analysis and dual-luciferase reporter assay were performed to evaluate the interaction among PEG10, miR-101-3p, and KIF2A.

Results

PEG10 and KIF2A level were significantly upregulated, while miR-101-3p was downregulated in DLBCL tissues and cells. PEG10 positively regulated KIF2A level in DLBCL. PEG10, or KIF2A deletion significantly inhibited the proliferative, migratory, and invasive abilities of DLBCL cells and elevated cell apoptosis in DLBCL cells. KIF2A upregulation partially reversed the effects of PEG10 downregulation on cell growth, metastasis, and apoptosis in DLBCL. Moreover, PEG10 negatively regulated miR-101-3p level and miR-101-3p upregulation exerted inhibition effects on the progression of DLBCL. Besides, miR-101-3p was a target of PEG10 and miR-101-3p could directly target KIF2A. PEG10 promoted KIF2A level by sponging miR-101-3p.

Conclusions

Our findings revealed that PEG10 played an oncogenic role in DLBCL progression, which might be a potential target for the treatment of DLBCL.

MiR-20a inhibits the progression of human arthritis fibroblast-like synoviocytes and inflammatory factor expression by targeting ADAM10

MiR-20a has been reported as a key regulator to pro-inflammatory factor release in fibroblast-like synoviocytes (FLS), which caused rheumatoid arthritis (RA). However, the molecular mechanism of miR-20a in RA remains to be further elucidated. This study aimed to investigate the roles of miR-20a in RA pathology. RA (n = 24) and osteoarthritis (OA, n = 20) and normal healthy tissues (n = 16) were collected from operation. TargetScan and dual-luciferase reporter were performed to predict and confirm the potential binding sites of miR-20a on ADAM metallopeptidase domain 10 (ADAM10). Pearson's analysis was adopted to evaluate the correlation between miR-20a and ADAM10 expression. It was found that MiR-20a was downregulated in RA tissues, and overexpressed miR-20a inhibited cell viability, migration and invasion, and the expression of inflammatory factors in RA-FLS MH7A cells. ADAM10 was identified as the target gene of miR-20a, and upregulation of ADAM10 reversed the inhibitory effects of miR-20a. In conclusion, miR-20a inhibits the progression of RA-FLS as well as the inflammatory factor expression by targeting ADAM10.

Lung CSC-derived exosomal miR-210-3p contributes to a pro-metastatic phenotype in lung cancer by targeting FGFRL1

Lung cancer has the highest mortality rate among human cancers, and the majority of deaths can be attributed to metastatic spread. Lung cancer stem cells (CSCs) are a component of the tumour microenvironment that contributes to this process. Exosomes are small membrane vesicles secreted by all types of cells that mediate cell interactions, including cancer metastasis. Here, we show that lung CSC-derived exosomes promote the migration and invasion of lung cancer cells, up-regulate expression levels of N-cadherin, vimentin, MMP-9 and MMP-1, and down-regulate E-cadherin expression. Moreover, we verified that these exosomes contribute to a pro-metastatic phenotype in lung cancer cells via miR-210-3p transfer. The results of bioinformatics analysis and dual-luciferase reporter assays further indicated that miR-210-3p may bind to fibroblast growth factor receptor-like 1 (FGFRL1); silencing FGFRL1 enhanced the metastatic ability of lung cancer cells, whereas overexpressing FGFRL1 suppressed metastasis. Taken together, our results provide new insights into a potential molecular mechanism whereby lung CSC-derived exosomal miR-210-3p targets FGFRL1 to promote lung cancer metastasis. FGFRL1 may be a promising therapeutic target in lung cancer.

Reawakening the Developmental Origins of Cancer Through Transposable Elements

Transposable elements (TEs) have an established role as important regulators of early human development, functioning as tissue-specific genes and regulatory elements. Functional TEs are highly active during early development, and interact with important developmental genes, some of which also function as oncogenes. Dedifferentiation is a hallmark of cancer, and is characterized by genetic and epigenetic changes that enable proliferation, self-renewal and a metabolism reminiscent of embryonic stem cells. There is also compelling evidence suggesting that the path to dedifferentiation in cancer can contribute to invasion and metastasis. TEs are frequently expressed in cancer, and recent work has identified a newly proposed mechanism involving extensive recruitment of TE-derived promoters to drive expression of oncogenes and subsequently promote oncogenesis—a process termed onco-exaptation. However, the mechanism by which this phenomenon occurs, and the extent to which it contributes to oncogenesis remains unknown. Initial hypotheses have proposed that onco-exaptation events are cancer-specific and arise randomly due to the dysregulated and hypomethylated state of cancer cells and abundance of TEs across the genome. However, we suspect that exaptation-like events may not just arise due to chance activation of novel regulatory relationships as proposed previously, but as a result of the reestablishment of early developmental regulatory relationships. Dedifferentiation in cancer is well-documented, along with expression of TEs. The known interactions between TEs and pluripotency factors such as NANOG and OCTt4 during early development, along with the expression of some placental-specific TE-derived transcripts in cancer support a possible link between TEs and dedifferentiation of tumor cells. Thus, we hypothesize that onco-exaptation events can be associated with the epigenetic reawakening of early developmental TEs to regulate expression of oncogenes and promote oncogenesis. We also suspect that activation of these early developmental regulatory TEs may promote dedifferentiation, although at this stage it is hard to predict whether TE activation is one of the initial drivers of dedifferentiation. We expect that developmental TE activation occurs as a result of the establishment of an epigenetic landscape in cancer that resembles that of early development and that developmental TE activation may also enable cancers to exploit early developmental pathways, repurposing them to promote malignancy.

RETRACTED: LncRNA MIR7-3HG executes a positive role in retinoblastoma progression via modulating miR-27a-3p/PEG10 axis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors since upon institutional inspection, the reproducibility of the CCK-8 assay was not sufficient and considered not to be valid and therefore could not support the conclusions of the article.

Functional Study of the Retrotransposon-Derived Human PEG10 Protease

Paternally expressed gene 10 (PEG10) is a human retrotransposon-derived imprinted gene. The mRNA of PEG10 encodes two protein isoforms: the Gag-like protein (RF1_PEG10) is coded by reading frame 1, while the Gag-Pol-like polyprotein (RF1/RF2_PEG10) is coded by reading frames 1 and 2. The proteins are translated by a typical retroviral frameshift mechanism. The protease (PR) domain of RF2_PEG10 contains an -Asp-Ser-Gly- sequence, which corresponds to the consensus -Asp-Ser/Thr-Gly- active-site motif of retroviral aspartic proteases. The function of the aspartic protease domain of RF2_PEG10 remains unclear. To elucidate the function of PEG10 protease (PR_PEG10), we designed a frameshift mutant (_fsRF1/RF2_PEG10) for comparison with the RF1/RF2_PEG10 form. To study the effects of PR_PEG10 on cellular proliferation and viability, mammalian HEK293T and HaCaT cells were transfected with plasmids coding for either RF1/RF2_PEG10, the frameshift mutant (_fsRF1/RF2_PEG10), or a PR active-site (D370A) mutant _fsRF1/RF2_PEG10. Our results indicate that _fsRF1/RF2_PEG10 overexpression results in increased cellular proliferation. Remarkably, transfection with _fsRF1/RF2_PEG10 had a detrimental effect on cell viability. We hypothesize that PR_PEG10 plays an important role in the function of this retroviral remnant, mediating the proliferation of cells and possibly implicating it in the inhibition of apoptosis.

Improving Cancer Drug Discovery by Studying Cancer across the Tree of Life

Despite a considerable expenditure of time and resources and significant advances in experimental models of disease, cancer research continues to suffer from extremely low success rates in translating preclinical discoveries into clinical practice. The continued failure of cancer drug development, particularly late in the course of human testing, not only impacts patient outcomes, but also drives up the cost for those therapies that do succeed. It is clear that a paradigm shift is necessary if improvements in this process are to occur. One promising direction for increasing translational success is comparative oncology-the study of cancer across species, often involving veterinary patients that develop naturally-occurring cancers. Comparative oncology leverages the power of cross-species analyses to understand the fundamental drivers of cancer protective mechanisms, as well as factors contributing to cancer initiation and progression. Clinical trials in veterinary patients with cancer provide an opportunity to evaluate novel therapeutics in a setting that recapitulates many of the key features of human cancers, including genomic aberrations that underly tumor development, response and resistance to treatment, and the presence of comorbidities that can affect outcomes. With a concerted effort from basic scientists, human physicians and veterinarians, comparative oncology has the potential to enhance the cost-effectiveness and efficiency of pipelines for cancer drug discovery and other cancer treatments.

Prediction of relapse and prognosis by expression levels of long noncoding RNA PEG10 in glioma patients

BACKGROUND

Long noncoding RNA paternally expressed 10 (lncRNA PEG10) is highly expressed in a variety of human cancers and related to the clinical prognosis of patients. However, to date there has been no previous study evaluating the prognostic significance of lncRNA PEG10 in gliomas. In the present study, we investigated the expression levels of lncRNA PEG10 to determine the prognostic value of this oncogene in human gliomas.

METHODS

Expression levels of lncRNA PEG10 were detected by real-time polymerase chain reaction in a hospital-based study cohort of 147 glioma patients and 23 cases of patients with craniocerebral trauma tissues. Associations of lncRNA PEG10 expression with clinicopathological variables and clinical outcome of glioma patients were investigated.

RESULTS

The results indicated that expression levels of lncRNA PEG10 were significantly increased in human gliomas compared to normal control brain tissues. In addition, lncRNA PEG10 expression was progressively increased from pathologic grade I to IV (P = .009) and correlated with the Karnofsky performance status (P = .018) in glioma patients. Furthermore, we also found that glioma patients with increased expression of lncRNA PEG10 had a higher risk to relapse and a statistically significant shorter overall survival (OS) than patients with reduced expression of lncRNA PEG10. In multivariate analysis, expression level of lncRNA PEG10 was found to be an independent prognostic factor for both progression-free survival and OS in glioma patients.

CONCLUSIONS

LncRNA PEG10 served as an oncogene and played crucial roles in the progression of glioma. Molecular therapy targeted on lncRNA PEG10 might bring significant benefits to the clinical outcome of malignant glioma.

Phosphorylated E2F1 is stabilized by nuclear USP11 to drive Peg10 gene expression and activate lung epithelial cells

Phosphorylation affects ubiquitination, stability, and activity of transcriptional factors, thus regulating various cellular functions. E2F transcriptional factor 1 (E2F1) regulates paternally expressed imprinted gene 10 (Peg10) expression, thereby promoting cell proliferation. However, the effect of E2F1 stability on Peg10 expression and the molecular regulation of E2F1 stability by its phosphorylation have not been well demonstrated. Here, we describe a new pathway in which phosphorylation of E2F1 by GSK3β increases E2F1 association with the deubiquitinating enzyme, ubiquitin-specific protease 11 (USP11), which removes K63-linked ubiquitin chains thereby preventing E2F1 degradation in the nuclei. Downregulation of USP11 increases E2F1 ubiquitination and reduces E2F1 stability and protein levels, thereby decreasing Peg10 mRNA levels. Physiologically, USP11 depletion suppresses cell proliferation and wound healing in lung epithelial cells, and these effects are reversed by E2F1 and PEG10 overexpression. Thus, our study reveals a new molecular model that phosphorylation promotes substrate stability through increasing its association with a deubiquitinating enzyme. The data suggest that GSK3β and USP11 act in concert to modulate E2F1 abundance and PEG10 expression in lung epithelial cells to affect cell wound healing. This study provides new therapeutic targets to lessen lung injury by improving lung epithelial cell repair and remodeling after injury.

Exploring the Molecular Mechanism of the Drug-Treated Breast Cancer Based on Gene Expression Microarray

: Breast cancer (BRCA) remains the leading cause of cancer morbidity and mortality worldwide. In the present study, we identified novel biomarkers expressed during estradiol and tamoxifen treatment of BRCA. The microarray dataset of E-MTAB-4975 from Array Express database was downloaded, and the differential expressed genes (DEGs) between estradiol-treated BRCA sample and tamoxifen-treated BRCA sample were identified by limma package. The pathway and gene ontology (GO) enrichment analysis, construction of protein-protein interaction (PPI) network, module analysis, construction of target genes-miRNA interaction network and target genes-transcription factor (TF) interaction network were performed using bioinformatics tools. The expression, prognostic values, and mutation of hub genes were validated by SurvExpress database, cBioPortal, and human protein atlas (HPA) database. A total of 856 genes (421 up-regulated genes and 435 down-regulated genes) were identified in T47D (overexpressing Split Ends (SPEN) + estradiol) samples compared to T47D (overexpressing Split Ends (SPEN) + tamoxifen) samples. Pathway and GO enrichment analysis revealed that the DEGs were mainly enriched in response to lysine degradation II (pipecolate pathway), cholesterol biosynthesis pathway, cell cycle pathway, and response to cytokine pathway. DEGs (MCM2, TCF4, OLR1, HSPA5, MAP1LC3B, SQSTM1, NEU1, HIST1H1B, RAD51, RFC3, MCM10, ISG15, TNFRSF10B, GBP2, IGFBP5, SOD2, DHF and MT1H) , which were significantly up- and down-regulated in estradiol and tamoxifen-treated BRCA samples, were selected as hub genes according to the results of protein-protein interaction (PPI) network, module analysis, target genes-miRNA interaction network and target genes-TF interaction network analysis. The SurvExpress database, cBioPortal, and Human Protein Atlas (HPA) database further confirmed that patients with higher expression levels of these hub genes experienced a shorter overall survival. A comprehensive bioinformatics analysis was performed, and potential therapeutic applications of estradiol and tamoxifen were predicted in BRCA samples. The data may unravel the future molecular mechanisms of BRCA.

PEG10 is associated with treatment-induced neuroendocrine prostate cancer

Neuroendocrine (NE) differentiation of advanced prostate adenocarcinoma following androgen receptor (AR) axis-directed therapy is becoming increasingly recognized. Several models of this transdifferentiation provide insight into its molecular pathogenesis and have highlighted the placental gene PEG10 for further study. Using our unique model of enzalutamide resistance (ENZR) and NE differentiation, we studied PEG10/AR interplay in enzalutamide treatment-resistant cell lines 42DENZR and 42FENZR compared to LNCaP and castration-resistant 16DCRPC cells. ENZR cell lines with positive terminal NE marker status also displayed higher baseline expression of PEG10 compared to LNCaP and 16DCRPC. Antagonism of AR activity increased PEG10 expression followed by an increase in terminal NE markers. Conversely, stimulating AR activity via androgen supplementation reversed PEG10 and NE marker expression in a time and dose-dependent manner. These results were supported by human data showing that PEG10 expression is highest in NEPC and that AR-dependent gene, PSA, is negatively correlated with PEG10 in adenocarcinoma. Further, ChIP assay confirmed binding of activated AR to the PEG10 enhancer, decreasing PEG10 expression. While PEG10 did not drive NEPC, its knockdown reduced NE markers in our cell lines. Moreover, PEG10 knockdown in vitro- and in vivo-attenuated tumor growth. Overall, these observations indicate that PEG10 is an AR-repressed gene which modulates NE markers in ENZR cells and targeting PEG10 in advanced prostate cancer with NE features is a rational and viable option.

PEG10 counteracts signaling pathways of TGF-β and BMP to regulate growth, motility and invasion of SW1353 chondrosarcoma cells

Recently, we reported highly active transforming growth factor (TGF)-β and bone morphogenetic protein (BMP) signaling in human chondrosarcoma samples and concurrent downregulation of paternally expressed gene 10 (PEG10). PEG10 expression was suppressed by TGF-β signaling, and PEG10 interfered with the TGF-β and BMP-SMAD pathways in chondrosarcoma cells. However, the roles of PEG10 in bone tumors, including chondrosarcoma, remain unknown. Here, we report that PEG10 promotes SW1353 chondrosarcoma cell growth by preventing TGF-β1-mediated suppression. In contrast, PEG10 knockdown augments the TGF-β1-induced motility of SW1353 cells. Individually, TGF-β1 and PEG10 siRNA increase AKT phosphorylation, whereas an AKT inhibitor, MK2206, mitigates the effect of PEG10 silencing on cell migration. SW1353 cell invasion was enhanced by BMP-6, which was further increased by PEG10 silencing. The effect of siPEG10 was suppressed by inhibitors of matrix metalloproteinase (MMP). BMP-6 induced expression of MMP-1, -3, and -13, and PEG10 lentivirus or PEG10 siRNA downregulated or further upregulated these MMPs, respectively. PEG10 siRNA increased BMP-6-induced phosphorylation of p38 MAPK and AKT, whereas the p38 inhibitor SB203580 and MK2206 diminished SW1353 cell invasion by PEG10 siRNA. SB203580 and MK2206 impeded the enhancing effect of PEG10 siRNA on the BMP-6-induced expression of MMP-1, -3, and -13. Our findings suggest dual functions for PEG10: accelerating cell growth by suppressing TGF-β signaling and inhibiting cell motility and invasion by interfering with TGF-β and BMP signaling via the AKT and p38 pathways, respectively. Thus, PEG10 might be a molecular target for suppressing the aggressive phenotypes of chondrosarcoma cells.

TSG101 promotes the proliferation, migration and invasion of hepatocellular carcinoma cells by regulating the PEG10

The tumour susceptibility gene 101 (TSG101) is reported to play important roles in the development and progression of several human cancers. However, its potential roles and underlined mechanisms in human hepatocellular carcinoma (HCC) are still needed to be further clarified. In the present study, we reported that knock down of TSG101 suppressed the proliferation, migration and invasion of HCC cells, while overexpression of TSG101 facilitated them. Molecularly, the results revealed that knock down of TSG101 significantly decreased the cell cycle related regulatory factor p53 and p21. In another point, knock down of TSG101 also obviously decreased the level of metallopeptidase inhibitor TIMP1 (Tissue inhibitors of metalloproteinases 1), which results in inhibition of MMP2, MMP7 and MMP9. In contrast, overexpression of TSG101 had opposite effects. The iTRAQ proteomics analysis identified that oncogenic protein PEG10 (Paternally expressed gene 10) might be a potential downstream target of TSG101. Further investigation showed that TSG101 interacted with PEG10 and protected it from proteasomal degradation thereby regulating the expression of p53, p21 and MMPs. Finally, we found that both TSG101 and PEG10 proteins are up-regulated and presented a direct correlation in HCC patients. In conclusion, these results suggest that TSG101 is up-regulated in human HCC patients, which may accelerate the proliferation, migration and invasion of HCC cells through regulating PEG10.

Periconceptional Maternal Mediterranean Diet Is Associated With Favorable Offspring Behaviors and Altered CpG Methylation of Imprinted Genes

Background: Maternal diet during pregnancy has been shown to influence the child neuro-developmental outcomes. Studies examining effects of dietary patterns on offspring behavior are sparse. Objective: Determine if maternal adherence to a Mediterranean diet is associated with child behavioral outcomes assessed early in life, and to evaluate the role of differentially methylated regions (DMRs) regulating genomically imprinted genes in these associations. Methods: Among 325 mother/infant pairs, we used regression models to evaluate the association between tertiles of maternal periconceptional Mediterranean diet adherence (MDA) scores derived from a Food Frequency Questionnaire, and social and emotional scores derived from the Infant Toddler Social and Emotional Assessment (ITSEA) questionnaire in the second year of life. Methylation of nine genomically imprinted genes was measured to determine if MDA was associated with CpG methylation. Results: Child depression was inversely associated with maternal MDA (Bonferroni-corrected p = 0.041). While controlling for false-discovery, compared to offspring of women with the lowest MDA tertile, those with MDA scores in middle and high MDA tertiles had decreased odds for atypical behaviors [OR (95% CI) = 0.40 (0.20, 0.78) for middle and 0.40 (0.17, 0.92) for highest tertile], for maladaptive behaviors [0.37 (0.18, 0.72) for middle tertile and 0.42 (0.18, 0.95) for highest tertile] and for an index of autism spectrum disorder behaviors [0.46 (0.23, 0.90) for middle and 0.35 (0.15, 0.80) for highest tertile]. Offspring of women with the highest MDA tertile were less likely to exhibit depressive [OR = 0.28 (0.12, 0.64)] and anxiety [0.42 (0.18, 0.97)] behaviors and increased odds of social relatedness [2.31 (1.04, 5.19)] behaviors when compared to low MDA mothers. Some associations varied by sex. Perinatal MDA score was associated with methylation differences for imprinted control regions of PEG10/SGCE [females: Beta (95% CI) = 1.66 (0.52, 2.80) - Bonferroni-corrected p = 0.048; males: -0.56 (-1.13, -0.00)], as well as both MEG3 and IGF2 in males [0.97 (0.00, 1.94)] and -0.92 (-1.65, -0.19) respectively. Conclusion: In this ethnically diverse cohort, maternal adherence to a Mediterranean diet in early pregnancy was associated with favorable neurobehavioral outcomes in early childhood and with sex-dependent methylation differences of MEG3, IGF2, and SGCE/PEG10 DMRs.

PEG10 as an oncogene: expression regulatory mechanisms and role in tumor progression

Cancer is a major public health problem as one of the leading causes of death worldwide. Deciphering the molecular regulation mechanisms of tumor progression can make way for tumor diagnosis and therapy. Paternally expressed gene 10 (PEG10), located on human chromosome 7q21.3, has turned out to be an oncogene implicated in the proliferation, apoptosis and metastasis of tumors. PEG10 has been found to be positively expressed in a variety of cancers with seemingly complex expression regulation mechanisms. In this review, we focus on the most vital factors influencing PEG10 expression and recapitulate some of the currently known and potential mechanisms of PEG10 affecting tumor progression, as understanding the molecular regulatory mechanisms of tumor progression can provide potential PEG10 related diagnosis and biomarker specific targeted therapies.

Prognostic value of PEG10 in Asian solid tumors: A meta-analysis

BACKGROUND

The involvement of paternally expressed gene 10 (PEG10) in the development of solid tumors has been demonstrated. However, the available data have not yet been fully analyzed. We conducted this meta-analysis to evaluate the correlations between PEG10 and the clinicopathological characteristics in patients with solid tumors.

METHODS

An electronic search for relevant articles was conducted in PubMed, Web of Science, Cochrane Library, EMBASE, Chinese CNKI, and Wan Fang. The relationships between PEG10 and the clinicopathological features and prognosis of patients with cancer were determined using pooled odds ratios and hazard ratios with 95% confidence interval (CI).

RESULTS

Ten studies comprising 1014 patients were included. The pooled analyses indicated the significant association of PEG10 overexpression with the risk of cancer, differentiation, lymph node metastasis and advanced TNM stage, but not with gender in cancer patients. Moreover, a high level of PEG10 expression correlated with poor prognosis and could be used as an independent prognostic biomarker for patients with solid tumors.

CONCLUSIONS

PEG10 expression is associated with advanced clinicopathological characteristics and can be used as a prognostic biomarker in patients with solid tumors.

Profiling, clinicopathological correlation and functional validation of specific long non-coding RNAs for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent and aggressive malignancies worldwide. Studies seeking to advance the overall understanding of lncRNA profiling in HCC remain rare.

Methods

The transcriptomic profiling of 12 HCC tissues and paired adjacent normal tissues was determined using high-throughput RNA sequencing. Fifty differentially expressed mRNAs (DEGs) and lncRNAs (DELs) were validated in 21 paired HCC tissues via quantitative real-time PCR. The correlation between the expression of DELs and various clinicopathological characteristics was analyzed using Student’s t-test or linear regression. Co-expression networks between DEGs and DELs were constructed through Pearson correlation co-efficient and enrichment analysis. Validation of DELs’ functions including proliferation and migration was performed via loss-of-function RNAi assays.

Results

In this study, we identified 439 DEGs and 214 DELs, respectively, in HCC. Furthermore, we revealed that multiple DELs, including NONHSAT003823, NONHSAT056213, NONHSAT015386 and especially NONHSAT122051, were remarkably correlated with tumor cell differentiation, portal vein tumor thrombosis, and serum or tissue alpha fetoprotein levels. In addition, the co-expression network analysis between DEGs and DELs showed that DELs were involved with metabolic, cell cycle, chemical carcinogenesis, and complement and coagulation cascade-related pathways. The silencing of the endogenous level of NONHSAT122051 or NONHSAT003826 could significantly attenuate the mobility of both SK-HEP-1 and SMMC-7721 HCC cells.

Conclusion

These findings not only add knowledge to the understanding of genome-wide transcriptional evaluation of HCC but also provide promising targets for the future diagnosis and treatment of HCC.

Co-option of endogenous viral sequences for host cell function

Eukaryotic genomes are littered with sequences of diverse viral origins, termed endogenous viral elements (EVEs). Here we used examples primarily drawn from mammalian endogenous retroviruses to document how the influx of EVEs has provided a source of prefabricated coding and regulatory sequences that were formerly utilized for viral infection and replication, but have been occasionally repurposed for cellular function. While EVE co-option has benefited a variety of host biological functions, there appears to be a disproportionate contribution to immunity and antiviral defense. The mammalian embryo and placenta offer opportunistic routes of viral transmission to the next host generation and as such they represent hotbeds for EVE cooption. Based on these observations, we propose that EVE cooption is initially driven as a mean to mitigate conflicts between host and viruses, which in turn acts as a stepping-stone toward the evolution of cellular innovations serving host physiology and development.

The H19-PEG10/IGF2BP3 axis promotes gastric cancer progression in patients with high lymph node ratios

We previously demonstrated that the lymph node ratio (LNR) is a prognostic factor associated with EGFR expression, among first priority genes amplified or overexpressed in cancer. Here, we investigated the associations between high LNR and second, third, and fourth priority genes. We performed mRNA expression microarray analysis of tumor tissue from patients with stage III gastric cancer and high or low LNRs. Candidate high LNR-associated genes were further evaluated in 39 patients with stage III gastric cancer. The functional relevance of these genes was evaluated in gastric cancer cell lines. We focused on five genes: H19,PEG10, IGF2BP3, CD177, and PGA3. H19 and PEG10 were confirmed as high LNR-associated genes. H19, PEG10, and IGF2BP3 were found to promote each other’s expression. Knocking down H19 or PEG10 using RNAi decreased cell proliferation, invasion, anchorage-independent growth, and chemoresistance. These genes had a mutual relationship in MKN7 cells. H19 knockdown decreased expression of epithelial-mesenchymal transition-associated genes in MKN74 cells to suppress transformation. Thus, H19 promotes epithelial-mesenchymal transition in gastric cancer and is a potential therapeutic target.

Expression of Radioresistant Gene PEG10 in OSCC Patients and Its Prognostic Significance

Background:

Oral squamous cell carcinoma (OSCC) is one of the most common forms of cancer occurring worldwide. PEG10 is well known as a paternally expressed gene from a newly recognized imprinted region at human chromosome 7q21. Previous study had demonstrated that the significant expression of PEG10 was found in radioresistant OSCC cell line and its expression was significantly associated with poor survival in several cancers. Therefore it has been evaluated as a potential marker in OSCC patients undergoing radiotherapy.

Objective:

This study was conducted to analyze the mRNA expression of PEG10 in OSCC and its expression in relation to clinicpathological features, radiotherapy treatment response and survival.

Methods:

This study included tissue specimens obtained via biopsy of 118 patients with OSCC who were recommended for radiotherapy treatment and 80 healthy control tissues analysis of mRNA expression of PEG10 was done by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Patients were treated with 70 Gy of radiation dose by shrinking field technique using Cobalt-60 teletherapy machine.

Results:

Significantly higher mRNA expression of PEG10 was found in OSCC patients when compared with matched controls. High level of PEG10 mRNA expression showed a significant correlation with lymph node metastasis (p = 0.0047) and tumor stage (p = 0.0499). Multivariate Cox regression analysis revealed that high level of mRNA expression of PEG10 was significantly associated with poor survival (p < 0.05). Our research demonstrated that the expression of PEG10 was higher in radioresistant tumor.

Conclusion:

We observed significantly increased expression of PEG10 in context of lymph node status, advanced stage and poor survival in our study. Thus PEG10 gene can be used as potential predictive and prognostic biomarker in OSCC patients undergoing radiotherapy.

Identification of the potential biomarkers for the metastasis of rectal adenocarcinoma

Rectal cancer is a common malignant tumor of the digestive tract, with a high incidence and high mortality. This study aimed to identify the potential biomarkers and therapeutic targets for rectal adenocarcinoma (RAC) metastasis. The expression profiling of RAC patients with metastasis and RAC patients without metastasis was downloaded from The Cancer Genome Atlas (TCGA) database. The datasets were used to identify the genes associated with RAC metastasis. Fifty up-regulated genes and seventeen down-regulated genes were identified in the primary tumor loci of RAC metastasis compared with non-metastasis. Sixty-seven dysregulated gens were conducted to construct the protein-protein network, and CCND3 was the hub protein. The dysregulated genes were significantly enriched in pancreatic secretion, cell adhesion molecules pathways, response to vitamin D of biological process, and retinoid binding of molecular function. Quantitative real-time polymerase chain reaction results demonstrated that CCND3, AQP3, PEG10, and RAB27B had the up-regulated tendency in RAC metastasis; ADCY1 had the down-regulated tendency in RAC metastasis. CCND3, AQP3, PEG10, RAB27B, and ADCY1 might play essential roles in the metastasis process of RAC through pancreatic secretion and cell adhesion molecules pathways. The five genes could be potential diagnosis biomarkers or therapeutic targets for RAC metastasis.

PEG10 is imperative for TGF-β1-induced epithelial‑mesenchymal transition in hepatocellular carcinoma

Substantial evidence indicates that transforming growth factor-beta 1 (TGF-β1) plays a vital role in epithelial-mesenchymal transition (EMT). PEG10 has been shown involved in invasion and metastasis of tumors. The present study investigated the role of PEG10 in TGF-β1-triggered EMT in hepatocellular carcinoma (HCC) progression. Immunohistochemistry and real-time PCR were used to measure the expression level of PEG10 in clinical HCC tissues with or without lymph node metastasis, and normal tissues. The results showed that PEG10 expression is higher in HCC tissues and associated with overall survival (OS) and lymph node metastasis. Moreover, PEG10 expression level was remarkably higher in hepatic cancer cells than the normal hepatic cell line L02. In the present study, we constructed an adenovirus vector containing the coding area of PEG10 (Ad-PEG10) and infected HepG2 cells and found that overexpression of PEG10 promoted the cell migration, invasion ability and EMT of HepG2 cells. TGF-β1 acted on HepG2 cells by enhancing cell migration, invasion, EMT and upregulating PEG10 expression level. However, cells pretreated with adenovirus vector of PEG10 shRNAs (Ad-shRNA1 and Ad-shRNA2) did not occur EMT prior to TGF-β1 stimulation. Moreover, TGF-β1 did not increase the migration and invasion of cells with PEG10 knockdown and overexpression of PEG10 confers chemoresistance to HepG2 cells. Accordingly, sufficient PEG10 expression level is essential for TGF-β1 induced EMT and associated with the chemoresistance in HepG2 cells.