Long non-coding RNA XIST: a novel oncogene in multiple cancers.

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is an important lncRNA derived from the XIST gene in mammals. XIST is abnormally expressed in numerous tumors, in most of which XIST functions as an oncogene. XIST is involved in multiple aspects of carcinogenesis, including tumor onset, progression, and prognosis. In our review, we collected and analyzed the recent studies on the impact of XIST in human tumor development. The multilevel molecular functions of XIST in human tumors are comprehensively reviewed to clarify the pathologic mechanisms and to offer a novel direction for further study.

Hsa_circRNA_0088036 acts as a ceRNA to promote bladder cancer progression by sponging miR-140-3p.

Circular RNAs (circRNAs) are a class of non-coding RNAs that play vital roles in cancer biology. However, the potential role of hsa_circRNA_0088036 in bladder cancer (BCa) remains unknown. Hsa_circRNA_0088036 was identified by microarray analysis and validated by quantitative real-time polymerase chain reaction. Functional assays were conducted to confirm the effects of hsa_circRNA_0088036 on the growth, migration, invasion, tumorigenesis, and metastasis of BCa cells. The luciferase reporter assay and RNA pull down assay were performed to investigate the interactions between hsa_circRNA_0088036, miR-140-3p, and forkhead box protein Q1 (FOXQ1). Upregulated expression of hsa_circRNA_0088036 in BCa tissues and cell lines was positively correlated with overall survival and clinicopathologic characteristics. Knockdown of hsa_circRNA_0088036 inhibited the growth, migration, and invasion of BCa cells both in vivo and in vitro. Mechanistically, hsa_circRNA_0088036 could directly interact with miR-140-3p and act as a miRNA sponge to modulate FOXQ1 expression. Knockdown of hsa_circRNA_0088036 inhibited the proliferation, migration, and metastasis of BCa cells via miR-140-3p/FOXQ1 signaling, suggesting that hsa_circRNA_0088036 is a potential biomarker and therapeutic target for BCa.

Identification and characterization of a complex pure mosaic of small supernumerary marker chromosomes involving 11p11.12 → q12.1 and 19p12 → q12 regions in a child featuring multiple congenital anomalies.

Unstable, gene-rich pericentric regions have been associated with various structural aberrations including small supernumerary marker chromosomes (sSMCs). We hereby report on a complex pure mosaic sSMCs derived from chromosomes 11 and 19 in a child featuring multiple congenital anomalies. As indicated by microarray analysis, the sSMCs have involved materials from 11p11.12 → q12.1 and 19p12 → q12 in complex forms (with four cell lines harboring from 1 to 4 sSMCs) in all peripheral blood lymphocytes. The patient featured facial dysmorphism, generalized hypotonia, cryptorchidism, transverse palmar creases, cerebral hemorrhage, atrial septal defect secundum, strabismus, epilepsy, immunodeficiency, and severe cognitive and motor impairment. Literature review indicated this to be a unique sSMCs case simultaneously involving chromosomes 11 and 19, with one sSMC containing materials from the both chromosomes. We propose that the involved chromosomal regions may contain dosage-sensitive genes which are important for the development, and that the sSMCs derived from multiple origins have formed by a complex mechanism.

[Chromosomal abnormality diagnosis of male infertility by QF-PCR].

To assess the clinical practice of quantitative fluorescence PCR (QF-PCR) in genetic diagnosis of male infertility patients, 78 nonobstructive male infertility patients were pooled for semen routine screening and sexual hormone determination; QF-PCR was applied to detect the polymorphic short tandem repeat (STR) and specific sequence tagged site (STS) of sex chromosomes; routine chromosome G-band was used for karyotype analysis and PCR was used for the detection of AZF microdeletion. Routine screening of semen found 18 azoospermia and 20 oligospermia patients (48.72%). Three patients with 47, XXY, two with 46,XX(SRY+)and one with AZFc microdeletion were detected using QF-PCR technique which were verified by chromosome G-band and PCR. This study suggests that QF-PCR is a comprehensive, rapid and reliable method for detecting abnormal chromosomal regions and microstructures compared with traditional tests and provides a better candidate for diagnosis of male infertility caused by chromosomal anomalies and gene mutation.

LncRNA H19: A novel oncogene in multiple cancers.

Long non-coding RNAs (lncRNAs) are a series of non-coding RNAs that lack open reading frameworks. Accumulating evidence suggests important roles for lncRNAs in various diseases, including cancers. Recently, lncRNA H19 (H19) became a research focus due to its ectopic expression in human malignant tumors, where it functioned as an oncogene. Subsequently, H19 was confirmed to be involved in tumorigenesis and malignant progression in many tumors and had been implicated in promoting cell growth, invasion, migration, epithelial-mesenchymal transition, metastasis, and apoptosis. H19 also sequesters some microRNAs, facilitating a multilayer molecular regulatory mechanism. In this review, we summarize the abnormal overexpression of H19 in human cancers, which suggests wide prospects for further research into the diagnosis and treatment of cancers.

PD-L1 tumor-intrinsic signaling and its therapeutic implication in triple-negative breast cancer.

Although the immune checkpoint role of programmed death ligand 1 (PD-L1) has been established and targeted in cancer immunotherapy, the tumor-intrinsic role of PD-L1 is less appreciated in tumor biology and therapeutics development, partly because of the incomplete mechanistic understanding. Here we demonstrate a potentially novel mechanism by which PD-L1 promotes the epithelial-mesenchymal transition (EMT) in triple-negative breast cancer (TNBC) cells by suppressing the destruction of the EMT transcription factor Snail. PD-L1 directly binds to and inhibits the tyrosine phosphatase PTP1B, thus preserving p38-MAPK activity that phosphorylates and inhibits glycogen synthase kinase 3ß (GSK3ß). Via this mechanism, PD-L1 prevents the GSK3ß-mediated phosphorylation, ubiquitination, and degradation of Snail and consequently promotes the EMT and metastatic potential of TNBC. Significantly, PD-L1 antibodies that confine the tumor-intrinsic PD-L1/Snail pathway restricted TNBC progression in immunodeficient mice. More importantly, targeting both tumor-intrinsic and tumor-extrinsic functions of PD-L1 showed strong synergistic tumor suppression effect in an immunocompetent TNBC mouse model. Our findings support that PD-L1 intrinsically facilitates TNBC progression by promoting the EMT, and this potentially novel PD-L1 signaling pathway could be targeted for better clinical management of PD-L1-overexpressing TNBCs.

Genotype-phenotype correlation in 75 patients with small supernumerary marker chromosomes.

BACKGROUND: Small supernumerary marker chromosomes (sSMCs) are rare structural abnormalities in the population; however, they are frequently found in children or fetuses with hypoevolutism and infertile adults. sSMCs are usually observed first by karyotyping, and further analysis of their molecular origin is important in clinical practice. Next-generation sequencing (NGS) combined with Sanger sequencing helps to identify the chromosomal origins of sSMCs and correlate certain sSMCs with a specific clinical picture. RESULTS: Karyotyping identified 75 sSMCs in 74,266 samples (0.1% incidence). The chromosomal origins of 27 of these sSMCs were detected by sequencing-related techniques (NGS, MLPA and STR). Eight of these sSMCs are being reported for the first time. sSMCs mainly derived from chromosomal X, Y, 15, and 18, and some sSMC chromosomal origins could be correlated with clinical phenotypes. However, the chromosomal origins of the remaining 48 sSMC cases are unknown. Thus, we will develop a set of economical and efficient methods for clinical sSMC diagnosis. CONCLUSIONS: This study details the comprehensive characterization of 27 sSMCs. Eight of these sSMCs are being reported here for the first time, providing additional information to sSMC research. Identifying sSMCs may reveal genotype-phenotype correlations and integrate genomic data into clinical care.

[Association of -63A/C polymorphism of glutathione S-transferase M3 gene with essential hypertension in Chinese population].

OBJECTIVE: To investigate the distribution of -63A/C polymorphism of human glutathione S-transferase M3(GSTM3) gene in Chinese Han population and the association of -63A/C polymorphism with essential hypertension (EH). METHODS: -63A/C polymorphism of GSTM3 gene was examined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 234 patients with EH and 328 healthy controls. The genotypes were confirmed partially by DNA sequencing. RESULTS: The distribution of GSTM3 -63A/C was in Hardy-Weinberg equilibrium. The CC genotype frequency in EH group (6%) was significantly higher than that in control group(1.8%) (P < 0.05). After adjustment for age, body mass index, and other risk factors, the CC genotype was independently associated with hypertension (OR=3.447, 95%CI: 1.19-7.63; P=0.04). CONCLUSION: The GSTM3 -63A/C polymorphism was associated with EH in Chinese Han population, the C allele might be a risk factor for EH in Chinese Han nationality.

Type Iγ phosphatidylinositol phosphate kinase regulates PD-L1 expression by activating NF-κB.

The programmed death-ligand 1 (PD-L1), by binding to PD-1 on the surface of immune cells, activates a major immune checkpoint pathway. Elevated expression of PD-L1 in tumor cells mediates tumor-induced T-cell exhaustion and immune suppression; therefore protect the survival of tumor cells. Although blockade of the PD-1/PD-L1 axis exhibits great potential in cancer treatment, mechanisms driving the up-regulation of PD-L1 in tumor cells remain not fully understood. Here we found that type Iγ phosphatidylinositol 4-phosphate (PtdIns(4)P) 5-kinase (PIPKIγ) is required for PD-L1 expression in triple negative breast cancer cells. Depletion of PIPKIγ inhibits both intrinsic and induced PD-L1 expression. Results from further analyses suggest that PIPKIγ promotes the transcription of the PD-L1 gene by activating the NF-κB pathway in these cells. These results demonstrate that PIPKIγ-dependent expression of PD-L1 is likely important for the progression of triple negative breast cancer.

A new small supernumerary marker chromosome involving 14pter → q12 in a child with severe neurodevelopmental retardation: case report and literature review.

Unstable, gene-rich pericentric regions have been associated with various structural aberrations including small supernumerary marker chromosomes (sSMCs). We hereby report on a new sSMC derived from chromosome 14, generating trisomy 14pter → q12 in a child with severe neurodevelopmental delay. The patient featured facial dysmorphism, generalized hypotonia, transverse palmar creases, structural brain abnormality, and severe cognitive and motor impairment. Literature review indicated this to be a unique case of sSMC 14 which was only composed of pter → q12, and the phenotype secondary to duplications of the similar region partially overlaps with the phenotype reported in this study. The genetic analysis on our case helps to better delineate karyotype-phenotype correlations between proximal trisomy 14 and associated clinical phenomena, and we also propose that the involved chromosomal regions may contain dosage-sensitive genes which are important for the development.

Over-expression of human cytomegalovirus miR-US25-2-3p downregulates eIF4A1 and inhibits HCMV replication.

It has been reported that human cytomegalovirus (HCMV) miR-US25-2 reduces DNA viral replication including HCMV. However, the mechanism remains unknown. In our study, eukaryotic translation initiation factor 4A1 (eIF4A1) was identified to be a direct target of miR-US25-2-3p. Small interfering RNA (siRNA) and miR-US25-2-3p mediated eIF4A1 knockdown experiments revealed that high level of miR-US25-2-3p in MRC-5 cells decreased HCMV and host genomic DNA synthesis, and inhibited cap-dependent translation and host cell proliferation. However, eIF4A1 up-regulation induced by miR-US25-2-3p inhibitor increased HCMV copy number. Therefore, the over-expression of miR-US25-2-3p and consequent lower expression of eIF4A1 may contribute to the inhibition of HCMV replication.

Identification of immediate early gene X-1 as a cellular target gene of hcmv-mir-UL148D.

Human cytomegalovirus (HCMV) is a herpesvirus that causes congenital diseases and opportunistic infections in immunocompromised individuals. Its functional proteins and microRNAs (miRNAs) facilitate efficient viral propagation by altering host cell behavior. The identification of functional target genes of miRNAs is an important step in the study of HCMV pathogenesis. HCMV encodes at least 14 miRNAs, including hcmv-mir-UL148D, which resides in the HCMV UL/b' region. hcmv-mir-UL148D is the only miRNA encoded by the HCMV UL/b' region; however, its targets and functional effects have not yet been eludidated. In this study, hybrid-PCR screening was used to identify target genes and dual luciferase reporter assay was used to evaluate the binding effect of hcmv-miR-UL148D to the 3' untranslated region (3'UTR) of IEX-1. In addition, western blot analysis was used to detect the expression kinetics of IEX-1 protein and apoptosis assay was used to identify the effects of hcmv-miR-UL148D on cell apoptosis. The hybrid-PCR results showed that only one binding site in the 3'UTR of the cellular gene, human immediate early gene X-1 (IEX-1), was completely complementary to an 11 nucleotide (nt) sequence in the 5' terminus of hcmv-mir-UL148D, including the entire seed region. The binding site was demonstrated to be functional by dual luciferase reporter assay with a 47% repression of the relative luciferase activity. In an in vitro system of human embryonic kidney 293 (HEK293) cells, the ectopically expressed hcmv-mir-UL148D exhibited a downregulatory effect on IEX-1 expression, and decreased the cell apoptosis induced by transfected IEX-1. Our data demonstrate that hcmv-mir-UL148D targets the cellular gene, IEX-1, downregulating its expression and thus results in anti-apoptotic effects.

MicroRNA-195-5p suppresses glucose uptake and proliferation of human bladder cancer T24 cells by regulating GLUT3 expression.

It has been reported that expression of glucose transporter member 3 (GLUT3) is up-regulated in bladder cancers. However, the regulating mechanism remains unknown. Here, we assessed whether microRNAs (miRNAs) regulate GLUT3 expression in bladder cancers. In our study, miR-195-5p was identified to directly targeted GLUT3 3'-untranslated region (UTR) in bladder cancer T24 cells. Small interfering RNA (siRNA)- and miR-195-5p-mediated GLUT3 knockdown experiments revealed that miR-195-5p decreased T24 cells glucose uptake, inhibited cell growth and promoted cell apoptosis through suppression of GLUT3 expression. Therefore, miR-195-5p is a novel and also the first identified miRNA that targets GLUT3, and the aberrant decreased expression of miR-195-5p and consequent GLUT3 up-regulation may contribute to bladder carcinogenesis.

Two novel mutations in the BCKDHB gene (R170H, Q346R) cause the classic form of maple syrup urine disease (MSUD).

Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder that is caused by mutations in the subunits of the branched-chain α-ketoacid dehydrogenase (BCKD) complex. BCKD is a mitochondrial complex encoded by four nuclear genes (BCKDHA, BCKDHB, DBT, and DLD) and is involved in the metabolism of branched-chain amino acids (BCAAs). In this study, we investigated the DNA sequences of BCKDHA, BCKDHB and DBT genes for mutations in a Chinese newborn with the classic form of MSUD and predicted the associated conformational changes using molecular modeling. We identified two previously unreported mutations in the BCKDHB gene, R170H (c.509G>A) in exon 5 and Q346R (c.1037 A>G) in exon 9. In silico analysis of the two novel missense mutations revealed that the mutation R170H-ß alters the spatial orientation with both Y195-ß' and S206-α, which results in unstable ß-ß' assembly and an unstable K(+) ion binding loop of the α subunit, respectively; The Q346R mutation is predicted to disrupt the spatial conformation between Q346-ß and I357-ß', which reduces the affinity of the ß-ß' subunits. These results indicate that R170-ß and Q346-ß are crucial for the activity of the E1 component. These two novel mutations, R170H and Q346R result in the patient's clinical manifestation of the classic form of MSUD.