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Triploidy is a genetic occurrence in which the chromosome count is 3n = 69 with a double (2n) chromosomal contribution to the conceptus from one parent. Such pregnancies are usually nonviable and are estimated to account for approximately 1% of recognized conceptions and 10% of recognized miscarriages. Majority opinion is that fetal losses due to triploidies are caused by the presence of 2 copies of paternal chromosomes. In this study, we present a digynic monoandric triploid miscarriage from a 32-year-old G7P1051 at approximately 13 weeks gestation, in which 2 copies of the maternal chromosomes are present in the fetus. This unusual phenomenon is supported by nonmolar placental histology, chromosomal microarray, and short tandem repeat assays, with the latter 2 being discussed in detail. Furthermore, this study includes discussion of recurrent miscarriage, recurrent triploidy, and long-term clinical follow-up of the patient.

The ongoing pandemic of coronavirus disease 2019 (COVID-19), which results from the rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a significant global public health threat, with molecular mechanisms underlying its pathogenesis largely unknown. Small non-coding RNAs (sncRNAs) are known to play important roles in almost all biological processes. In the context of viral infections, sncRNAs have been shown to regulate the host responses, viral replication, and host-virus interaction. Compared with other subfamilies of sncRNAs, including microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), tRNA-derived RNA fragments (tRFs) are relatively new and emerge as a significant regulator of host-virus interactions. Using T4 PNK-RNA-seq, a modified next-generation sequencing (NGS), we recently found that nasopharyngeal swabs (NPS) samples from SARS-CoV-2 positive and negative subjects show a significant difference in sncRNA profiles. There are about 166 SARS-CoV-2-impacted sncRNAs. Among them, tRFs are the most significantly affected and almost all impacted tRFs are derived from the 5’-end of tRNAs (tRF5). Using a modified qRT-PCR, which was recently developed to specifically quantify tRF5s by isolating the tRF signals from its corresponding parent tRNA signals, we validated that tRF5s derived from tRNA GluCTC (tRF5-GluCTC), LysCTT (tRF5-LysCTT), ValCAC (tRF5-ValCAC), CysGCA (tRF5-CysGCA) and GlnCTG (tRF5-GlnCTG) are enhanced in NPS samples of SARS-CoV2 patients and SARS-CoV2-infected airway epithelial cells. In addition to host-derived ncRNAs, we also identified several sncRNAs derived from the virus (svRNAs), among which a svRNA derived from CoV2 genomic site 346 to 382 (sv-CoV2-346) has the highest expression. The induction of both tRFs and sv-CoV2-346 has not been reported previously, as the lack of the 3’-OH ends of these sncRNAs prevents them to be detected by routine NGS. In summary, our studies demonstrated the involvement of tRFs in COVID-19 and revealed new CoV2 svRNAs.

Caspases play a vital role during apoptosis. In addition to apoptosis, caspases play a role in cytokine gene induction and work to inhibit apoptosis. In order for individuals to thrive with useful tissue growth, the rate of cell growth and division must surpass the rate of cell division. It is well established that excessive cell death of embryonic cells is a vital process occurring before structural abnormalities, regardless of their nature. Here we describe a 13-month-old male patient with a 4.7Mb interstitial duplication of chromosome 2q33.1. This duplication was identified by chromosomal microarray (CMA) which is the first-tier clinical diagnostic test to identify copy number variants (CNVs) for patients with unexplained developmental delay or intellectual disability. This patient presents with global developmental delay, especially in speech, language, hypotonia, and bilateral simian creases. The duplicated region contains several disease-causing genes. We believe that the phenotype in this patient's case was likely related to the gain of caspase 8 and 10 genes.

In hepatocyte-derived cell lines, either loss of aryl hydrocarbon receptor (AhR) function or treatment with a persistent AhR agonist such as 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) can disrupt G 1 phase cell cycle progression. The present study used liver regeneration to explore mechanistically how AhR activity modulates hepatocyte proliferation in vivo. Treatment of mice with 20 μg/kg TCDD 1 day before 70% partial hepatectomy (PH) resulted in a 50 to 75% suppression in liver regeneration. Impaired proliferation was not associated with changes in levels of interleukin-6 or tumor necrosis factor-α, which prime quiescent hepatocytes to enter G 1 phase. In fact, administration of TCDD 12 h after PH, a period well beyond the priming phase, still induced the G 1 arrest. Decreased proliferation in TCDD-treated mice correlated with reduced cyclin-dependent kinase-2 (CDK2) activity, a pivotal regulator of G 1 /S phase transition. In contrast to observations made in cell culture, suppressed CDK2 activity was not strictly associated with increased binding of the CDK2 inhibitors p21 Cip1 or p27 Kip1 . However, TCDD decreased levels of cyclin E binding to CDK2, despite normal cyclin E expression. The evidence also suggests that TCDD-induced hepatic growth arrest depends upon sustained AhR activity because transient AhR activation in response to endogenous queues failed to suppress the regenerative response. These findings establish a functional role for the AhR in regulating normal cell cycle control during liver regeneration.

The liver is the only solid organ that can respond to major tissue loss or damage by regeneration to restore liver biomass. The aryl hydrocarbon receptor (AhR) agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can disrupt the regenerative process, as evidenced by suppression of DNA synthesis in rat primary hepatocytes in culture and in vivo liver regeneration after partial hepatectomy. Independent observations demonstrated that AhR-mediated G(1) phase cell cycle arrest depends on an interaction with the retinoblastoma tumor suppressor protein (pRb), but differences exist regarding proposed mechanisms of action. Two distinct models have been proposed, one supporting the AhR-pRb interaction functioning in corepression of E2F activity and the other favoring an AhR-pRb interaction participating in transcriptional coactivation of genes encoding G(1) phase regulatory proteins. In the present study, experiments in rat hepatoma cells using dominant-negative DNA-binding-defective AhR and Ah receptor nuclear translocator (Arnt) mutants provided evidence that TCDD-induced AhR-mediated G(1) arrest is only partially regulated by direct AhR transcriptional activity, suggesting that both coactivation and corepression are involved. Studies using a small interfering RNA to down-regulate Arnt protein expression revealed that TCDD-induced G(1) arrest is absolutely dependent on the Arnt protein.

Background Hyper-methylation of CpG dinucleotides in the promoter region of inhibitor of cyclin-dependent kinase 4A (INK4A) has been reported in 60%-80% of hepatocellular carcinoma (HCC). As INK4A promoter hypermethylation event occurs early in HCC progression, the quantification of INK4A promoter methylation in blood sample may represent a useful biomarker for non-invasive diagnosis and prediction of response to therapy. Methods We examined INK4A promoter methylation using circulating cell-free DNA (ccfDNA) in a total of 109 serum specimens, including 66 HCC and 43 benign chronic liver diseases. Methylation of the individual seven CpG sites was examined using pyrosequencing. Results Our results showed that there were significantly higher levels of methylated INK4A in HCC specimens than controls and that the seven CpG sites had different levels of methylation and might exist in different PCR amplicons. The area under receiver operating characteristic (ROC) curve was 0.82, with 65.3% sensitivity and 87.2% specificity at 5% (LOD), 39.0% sensitivity and 96.5% specificity at 7% LOD, and 20.3% sensitivity and 98.8% specificity at 10% LOD, respectively. Conclusions Our results support additional studies incorporating INK4A methylation testing of ccfDNA to further validate the diagnostic, predictive, and prognostic characteristics of this biomarker in HCC patients. The knowledge of the existence of epi-alleles should help improve assay design to maximize detection.

HERV-K viral RNA has been reported in plasma specimens of HIV-1 infected individuals. Emerging data support the regulation and functional interaction between HERV-K and HIV-1, which warrant development of accurate HERV-K assays to evaluate HERV-K activation. In this study, we examined HERV-K RNA expression after careful removal of "contaminating" cellular DNA using DNase I. We found that DNase I digestion effectively reduced HERV-K RT-PCR positive signal. We also found that levels of HERV-K expression did not correlate with HIV-1 viral load. Our study is in agreement with the published studies on HERV-K activation in HIV-1 positive plasma specimens, and in addition, calls for careful removal of cellular DNA to accurately evaluate HERV-K RNA expression.

Human endogenous retroviruses (HERVs) are thought to be germline-integrated genetic remnants of exogenous retroviral infections and comprise approximately 8% of the human genome [1, 2]. Similar to exogenous retroviruses such as human immunodeficiency virus (HIV) and human T cell leukemia virus (HTLV), a complete HERV sequence is composed of GAG, POL, and ENV genes flanked by two long terminal repeats (LTRs). Although most HERVs are degenerated with disruptive open reading frames, a few proviruses have retained intact genes, and the corresponding proteins can thus be expressed [1, 3]. HERVs have been implicated in the etiology of cancer, chronic inflammation, and other diseases [2], and emerging data support a role of HERV-K in melanomagenesis. For example, HERV-K is activated in melanomas but not in melanocytes [4, 5], and inhibition of HERV-K by RNA interference (RNAi) suppresses the in vivo growth of melanoma cells [6-9]. We have demonstrated recently that expression of K-type human endogenous retrovirus (HERV-K) correlates with ERK activation and p16 loss in human melanoma specimens, and that inhibition of MEK and CDK4 in combination, suppresses HERV-K expression [10, 11]. Importantly, if HERV-K drives melanomagenesis downstream of the BRAF-MEK-ERK and p16/CDK4 pathways, when HERV-K is already turned on, cells may be resistant to thera‐ pies targeting BRAF-MEK-ERK and p16-CDK4. Triple therapies, such as simultaneous targeting of HERV-K, BRAF/MEK and CDK4, may be necessary to produce more effective and long-lasting therapeutic effects. This strategy is analogous to HIV “cocktail” therapy that disrupts human immunodeficiency virus (HIV) at different stages of viral replication and has brought many acquired immune deficiency syndrome (AIDS) patients from near death to fairly normal and productive lives.

Circulating extracellular nucleic acids, especially DNA, was discovered more than sixty years ago, but it is becoming hot just in the last two decades because it is now widely recognized as a very promising biomarker for the early diagnosis, monitoring, and evaluation of prognosis of cancer. In addition, compared with traditional surgical approaches and other biochemical tests, circulating DNA as a biomarker, owns many obvious advantages. It is easily accessible, reliable, reproducible and early detectable in cancer. It is also very sensitive and specific if cancer specific DNA alterations are tested instead of elevation of circulating DNA concentration. But the clinical application of this biomarker is still just limited to obstetrics and prenatal diagnosis. This review throws light on its history, current research update and potential clinical application in cancer diagnosis and management. In addition, major detection technologies of circulating DNA are summarized concisely and comprehensively.

The aryl hydrocarbon receptor (AhR) is a mediator of xenobiotic toxicity, best recognized for conveying the deleterious effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. The AhR functions as a ligand-activated transcription factor that binds to a canonical xenobiotic response element (XRE) in association with the heterodimerization partner, the AhR nuclear translocator (Arnt) protein. However, within the repertoire of AhR target genes identified in recent years, many lack a clearly defined XRE highlighting the growing realization that AhR-mediated gene expression seems to involve additional mechanisms distinct from the well characterized process involving the XRE. The present study characterized a novel nonconsensus XRE (NC-XRE) in the promoter of the plasminogen activator inhibitor-1 (PAI-1) gene that recruits a novel protein-DNA complex responsible for TCDD-inducible expression. DNA binding studies and reporter assays identified key residues in the NC-XRE necessary for protein-DNA binding and function, respectively. Functional studies with AhR expression constructs confirm that TCDD-inducibility is AhR-dependent and requires direct AhR-DNA binding to the NC-XRE. Chromatin immunoprecipitation and RNA interference studies reveal that the Arnt protein is not a component of the NC-XRE-bound AhR complex, suggesting that in contrast to the XRE, AhR-dependent gene expression mediated through the NC-XRE may involve a new DNA binding partner.

Liver homeostasis is achieved by the removal of diseased and damaged hepatocytes and their coordinated replacement to maintain a constant liver cell mass. Cirrhosis, viral hepatitis, and toxic drug effects can all trigger apoptosis in the liver as a means of removing the unwanted cells, and the Fas “death receptor” pathway comprises a major physiological mechanism by which this occurs. The susceptibility to Fas-mediated apoptosis is, in part, a function of the hepatocyte9s proteome. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor known to influence apoptosis, conceivably by regulating the expression of genes involved in apoptotic signaling. In this article, we present evidence demonstrating that AhR expression and function promote apoptosis in liver cells in response to Fas stimulation. Reintroduction of the AhR into the AhR-negative BP8 hepatoma cells as well as into primary hepatocytes from AhR knockout mice increases the magnitude of cell death in response to Fas ligand. Enhanced apoptosis correlates with increased caspase activity and mitochondrial cytochrome c release but not with the expression of several Bcl-2 family proteins. In vivo studies showed that in contrast to wild-type mice, AhR knockout mice are protected from the lethal effects of the anti-Fas Jo2 antibody. Moreover, down-regulation of the aryl hydrocarbon receptor nuclear translocator protein in vivo by adenovirus-mediated RNA interference to suppress AhR activity provided wild-type mice partial protection from Jo2-induced lethality.

Introduction and Hypothesis: Nuclear atypia with features of multi nuclei have been detected in human melanoma specimens. We found that the K type human endogenous retroviral element (HERV K) is expressed in such cells. Since cellular syncytia can form when cells are infected with retroviruses, we hypothesized that HERV K expressed in melanoma cells may contribute to the formation of multinuclear atypia cells in melanoma. Experiments and Results: We specifically inhibited HERV K expression using RNA interference (RNAi) and monoclonal antibodies and observed dramatic reduction of intercellular fusion of cultured melanoma cells. Importantly, we identified loss of heterozygosity (LOH)of D19S433 in a cell clone that survived and proliferated after cell fusion. Conclusion: Our results support the notion that proteins encoded by HERV K can mediate intercellular fusion of melanoma cells, which may generate multinuclear cells and drive the evolution of genetic changes that provide growth and survival advantages.