Adult Germ Cells Research Articles

IPLA2-VIA is required for healthy aging of neurons, muscle, and the female germline in Drosophila melanogaster.

Neurodegenerative disease (ND) is a growing health burden worldwide, but its causes and treatments remain elusive. Although most cases of ND are sporadic, rare familial cases have been attributed to single genes, which can be investigated in animal models. We have generated a new mutation in the calcium-independent phospholipase A2 (iPLA2) VIA gene CG6718, the Drosophila melanogaster ortholog of human PLA2G6/PARK14, mutations in which cause a suite of NDs collectively called PLA2G6-associated neurodegeneration (PLAN). Our mutants display age-related loss of climbing ability, a symptom of neurodegeneration in flies. Although phospholipase activity commonly is presumed to underlie iPLA2-VIA function, locomotor decline in our mutants is rescued by a transgene carrying a serine-to-alanine mutation in the catalytic residue, suggesting that important functional aspects are independent of phospholipase activity. Additionally, we find that iPLA2-VIA knockdown in either muscle or neurons phenocopies locomotor decline with age, demonstrating its necessity in both neuronal and non-neuronal tissues. Furthermore, RNA in situ hybridization shows high endogenous iPLA2-VIA mRNA expression in adult germ cells, and transgenic HA-tagged iPLA2-VIA colocalizes with mitochondria there. Mutant males are fertile with normal spermatogenesis, while fertility is reduced in mutant females. Mutant female germ cells display age-related mitochondrial aggregation, loss of mitochondrial potential, and elevated cell death. These results suggest that iPLA2-VIA is critical for mitochondrial integrity in the Drosophila female germline, which may provide a novel context to investigate its functions with parallels to PLAN.

Epigenomic modifications induced by hatchery rearing persist in germ line cells of adult salmon after their oceanic migration.

Human activities induce direct or indirect selection pressure on natural population and may ultimately affect population's integrity. While numerous conservation programs aimed to minimize human‐induced genomic variation, human‐induced environmental variation may generate epigenomic variation potentially affecting fitness through phenotypic modifications. Major questions remain pertaining to how much epigenomic variation arises from environmental heterogeneity, whether this variation can persist throughout life, and whether it can be transmitted across generations. We performed whole genome bisulfite sequencing (WGBS) on the sperm of genetically indistinguishable hatchery and wild‐born migrating adults of Coho salmon (Oncorhynchus kisutch) from two geographically distant rivers at different epigenome scales. Our results showed that coupling WGBS with fine‐scale analyses (local and chromosomal) allows the detection of parallel early‐life hatchery‐induced epimarks that differentiate wild from hatchery‐reared salmon. Four chromosomes and 183 differentially methylated regions (DMRs) displayed a significant signal of methylation differentiation between hatchery and wild‐born Coho salmon. Moreover, those early‐life epimarks persisted in germ line cells despite about 1.5 year spent in the ocean following release from hatchery, opening the possibility for transgenerational inheritance. Our results strengthen the hypothesis that epigenomic modifications environmentally induced during early‐life development persist in germ cells of adults until reproduction, which could potentially impact their fitness.

ZSP‐1 is a Z granule surface protein required for Z granule fluidity and germline immortality in Caenorhabditis elegans

Germ granules are biomolecular condensates that form in germ cells of all/most animals, where they regulate mRNA expression to promote germ cell function and totipotency. In the adult Caenorhabditis elegans germ cell, these granules are composed of at least four distinct sub-compartments, one of which is the Z granule. To better understand the role of the Z granule in germ cell biology, we conducted a genetic screen for genes specifically required for Z granule assembly or morphology. Here, we show that zsp-1, which encodes a low-complexity/polyampholyte-domain protein, is required for Z granule homeostasis. ZSP-1 localizes to the outer surface of Z granules. In the absence of ZSP-1, Z granules swell to an abnormal size, fail to segregate with germline blastomeres during development, and lose their liquid-like character. Finally, ZSP-1 promotes piRNA- and siRNA-directed gene regulation and germline immortality. Our data suggest that Z granules coordinate small RNA-based gene regulation to promote germ cell function and that ZSP-1 helps/is need to maintain Z granule morphology and liquidity.

Tumors Widely Express Hundreds of Embryonic Germline Genes.

Simple SummaryMany current cancer treatments also target healthy cells, leading to severe side effects, including infertility. Alternative more cancer specific targets, not expressed in any healthy tissue, would result in fewer side effects. To this aim we identified hundreds of genes expressed by cancer cells that are normally only expressed during the embryonic development of reproductive cells. Because these genes are not expressed in any healthy adult tissue, including the adult testis or ovary, their possible targeting is likely not to have any side effects. Moreover, many of these germ cell genes appear to contribute to typical cancer cell characteristics such as genome instability and metastasis. We indeed found that a relatively high amount of germ cell genes in lung cancer leads to a poor prognosis. We expect that these results will lead to a better understanding of cancer and provide multiple new targets with reduced side effects.We have recently described a class of 756 genes that are widely expressed in cancers, but are normally restricted to adult germ cells, referred to as germ cell cancer genes (GC genes). We hypothesized that carcinogenesis involves the reactivation of biomolecular processes and regulatory mechanisms that, under normal circumstances, are restricted to germline development. This would imply that cancer cells share gene expression profiles with primordial germ cells (PGCs). We therefore compared the transcriptomes of human PGCs (hPGCs) and PGC-like cells (PGCLCs) with 17,382 samples from 54 healthy somatic tissues (GTEx) and 11,003 samples from 33 tumor types (TCGA), and identified 672 GC genes, expanding the known GC gene pool by 387 genes (51%). We found that GC genes are expressed in clusters that are often expressed in multiple tumor types. Moreover, the amount of GC gene expression correlates with poor survival in patients with lung adenocarcinoma. As GC genes specific to the embryonic germline are not expressed in any adult tissue, targeting these in cancer treatment may result in fewer side effects than targeting conventional cancer/testis (CT) or GC genes and may preserve fertility. We anticipate that our extended GC dataset enables improved understanding of tumor development and may provide multiple novel targets for cancer treatment development.

PRIMARY MEDIASTINAL SEMINOMA FOUND ON EVALUATION FOR WEIGHT LOSS

SESSION TITLE: Medical Student/Resident Disorders of the Mediastinum Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Extragonadal germ cell tumors (GCTs) typically arise in midline locations such as mediastinum and retroperitoneum. They are formed either due to failure of primordial germ cells to migrate to the gonadal ridges [1] or reverse migration of the transformed germ cells in the testes [2]. Mediastinal seminomas are rare tumors constituting about 1/3rd of malignant mediastinal GCTs and 2-4 percent of mediastinal masses [3]. CASE PRESENTATION: A 55-year-old man with a history of active smoking (½ pack cigarettes per day), hepatitis C, bipolar disorder, prior alcohol/intravenous drug use (heroin and cocaine) presented with shortness of breath and 50-pound weight loss. Chest computed tomography (CT) revealed a 3.0 x 1.1 cm para-aortic lymph node. Positron emission tomography (PET/CT) scan showed hypermetabolic activity (maximum standardized uptake value of 10). Bronchoscopy with EBUS (endoscopic ultrasound) and mediastinoscopy were considered as methods to obtain tissue but discarded due to the location of the mass. He underwent a left Video-assisted thoracoscopic surgery (VATS) which showed seminoma. H&E (hematoxylin and eosin) slides revealed pale tumor cells with distinct nuclei and prominent central nucleoli in a background of lymphocytic infiltrate. The tumor cells stained positive for germ cell markers CD117, Oct 3/4 and Sall 4; but were negative for melanoma markers (Mart1a, S100), as well as CK20, CK7, Pancytokeratin, CD30, CD15, TTF1 and CDX2. DISCUSSION: Mediastinal seminomas occur mainly in men aged 20 to 40 years. They are typically slow growing and can be very bulky by the time they cause symptoms. Serum beta subunit of human chorionic gonadotropin (beta-hCG) is elevated in approximately one-third of patients. They do not produce alpha-fetoprotein (AFP). Ultrasound is advised in all cases to evaluate for any testicular primary. Seminomas are exquisitely sensitive to both cisplatin-based chemotherapy and radiotherapy (RT) but local control with surgery and RT only have modest success due to their typically later presentation. The commonly used chemotherapy regimens are 3 cycles of bleomycin/etoposide/cisplatin (BEP) or 4 cycles of etoposide/cisplatin (EP) (in patients who have previously received RT, who have underlying lung disease or age more than 50 years to avoid bleomycin lung toxicity). Long-term disease-free survival is achieved in roughly 90 percent of patients treated with chemotherapy. CONCLUSIONS: Primary mediastinal seminoma is a malignant extragonadal GCT most commonly found in the anterior mediastinum. Usually, young men in their 20-40s present with large 4-11cm anterior mediastinal masses which cause symptoms by compressing local structures. Or, as in our case, they are found incidentally. Surgery/RT can be considered but many patients present late so local control is not possible. However, these tumors respond well to chemotherapy with complete response rates of 90% Reference #1: Intracranial germ cell tumors: a comprehensive review of proposed embryologic derivation; Glenn OA, Barkovich AJ; Pediatr Neurosurg. 1996;24(5):242; PMID 8933567 Reference #2: Genetics and biology of adult human male germ cell tumors; Chaganti RS, Houldsworth J; Cancer Res. 2000;60(6):1475; PMID 10749107 Reference #3: Primary germ cell tumors of the mediastinum: II. Mediastinal seminomas--a clinicopathologic and immunohistochemical study of 120 cases; Moran CA, Suster S, Przygodzki RM, Koss MN; Cancer. 1997;80(4):691; PMID 9264352 DISCLOSURES: No relevant relationships by William Han, source=Web Response No relevant relationships by Sahib Singh, source=Web Response

Genome-wide identification of estrogen receptor binding sites reveals novel estrogen-responsive pathways in adult male germ cells.

Spermatogenesis occurs in the seminiferous epithelium that shows the presence of estrogen receptors alpha (ERα) and beta (ERβ), both of which regulate gene transcription by binding to the DNA. Estrogen responsive phases of spermatogenesis are well documented; however, the genes regulated remain inexplicit. To study the regulation of genes by estrogen in male germ cells, we performed chromatin immunoprecipitation (ChIP) sequencing for ERα and ERβ under normal physiological conditions. A total of 27 221 DNA binding regions were enriched with ERα and 20 926 binding sites with ERβ. Majority of the peaks were present in the intronic regions and located 20 kb upstream or downstream from the transcription start site (TSS). Pathway analysis of the genes enriched by ChIP-Seq showed involvement in several biological pathways. Genes involved in pathways whose role in spermatogenesis is unexplored were validated; these included prolactin, GnRH, and oxytocin signaling. All the selected genes showed the presence of estrogen response elements (EREs) in their binding region and were also found to be significantly enriched by ChIP-qPCR. Functional validation using seminiferous tubule culture after treatment with estrogen receptor subtype-specific agonist and antagonist confirmed the regulation of these genes by estrogen through its receptors. The genes involved in these pathways were also found to be regulated by the respective receptor subtypes at the testicular level in our in vivo estrogen receptor agonist rat models. Our study provides a genome-wide map of ERα and ERβ binding sites and identifies the genes regulated by them in the male germ cells under normal physiological conditions.

CDK4/6 inhibition presents as a therapeutic option for paediatric and adult germ cell tumours and induces cell cycle arrest and apoptosis via canonical and non-canonical mechanisms

BackgroundGerm cell tumours (GCTs) are the most common solid malignancies in young men. Although high cure rates can be achieved, metastases, resistance to cisplatin-based therapy and late toxicities still represent a lethal threat, arguing for the need of new therapeutic options. In this study, we analysed the potential of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors palbociclib and ribociclib (PaRi) as molecular drugs to treat cisplatin-resistant and -sensitive paediatric and adult GCTs.MethodsTen GCT cell lines, including cisplatin-resistant subclones and non-malignant controls, were treated with PaRi and screened for changes in viability (triphenyl tetrazolium chloride (XTT) assay), apoptosis rates (flow cytometry, caspase assay), the cell cycle (flow cytometry), the transcriptome (RNA-sequencing, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and on protein level (western blot). Expression profiling was performed on paediatric and adult GCT tissues (expression microarrays, qRT-PCR, immunohistochemistry, ‘The Cancer Genome Atlas’ database).ResultsWe demonstrate that adult GCTs highly express CDK4, while paediatric GCTs strongly express CDK6 instead. Thus, both GCT types are potentially treatable by PaRi. GCTs presented as highly sensitive towards PaRi, which caused a decrease in viability, cell cycle arrest and apoptosis. Although GCTs mainly arrested in the G1/G0 phase, some embryonal carcinoma cell lines were able to bypass the G1/S checkpoint and progressed to the G2/M phase. We found that upregulation of CDK3 and downregulation of many mitosis regulation factors, like the HAUS genes, might be responsible for bypassing the G1/S checkpoint and termination of mitosis, respectively. We postulate that GCT cells do not tolerate these alterations in the cell cycle and eventually induce apoptosis.ConclusionOur study highlights PaRi as therapeutic options for cisplatin-resistant and -sensitive paediatric and adult GCTs.

RiboTag Immunoprecipitation in the Germ Cells of the Male Mouse.

Quantifying differences in mRNA abundance is a classic approach to understand the impact of a given gene mutation on cell physiology. However, characterizing differences in the translatome (the whole of translated mRNAs) provides an additional layer of information particularly useful when trying to understand the function of RNA regulating or binding proteins. A number of methods for accomplishing this have been developed, including ribosome profiling and polysome analysis. However, both methods carry significant technical challenges and cannot be applied to specific cell populations within a tissue unless combined with additional sorting methods. In contrast, the RiboTag method is a genetic-based, efficient, and technically straightforward alternative that allows the identification of ribosome associated RNAs from specific cell populations without added sorting steps, provided an applicable cell-specific Cre driver is available. This method consists of breeding to generate the genetic models, sample collection, immunoprecipitation, and downstream RNA analyses. Here, we outline this process in adult male mouse germ cells mutant for an RNA binding protein required for male fertility. Special attention is paid to considerations for breeding with a focus on efficient colony management and the generation of correct genetic backgrounds and immunoprecipitation in order to reduce background and optimize output. Discussion of troubleshooting options, additional confirmatory experiments, and potential downstream applications is also included. The presented genetic tools and molecular protocols represent a powerful way to describe the ribosome-associated RNAs of specific cell populations in complex tissues or in systems with aberrant mRNA storage and translation with the goal of informing on the molecular drivers of mutant phenotypes.

Interaction between oocytes, cortical germ cells and granulosa cells of the mouse and bat, following the dissociation-re-aggregation of adult ovaries.

It is widely accepted that the oocyte plays a very active role in promoting the growth of the follicle by directing the differentiation of granulosa cells and secreting paracrine growth factors. In turn, granulosa cells regulate the development of the oocytes, establishing close bidirectional communication between germ and somatic cells. The presence of cortical cells with morphological characteristics, similar to primordial germ cells that express specific germline markers, stem cells and cell proliferation, known as adult cortical germ cells (ACGC) have been reported in phyllostomid bats. Using magnetic cell separation techniques, dissociation-cellular re-aggregation and organ culture, the behaviour of oocytes and ACGC was analyzed by interacting in vitro with mouse ovarian cells. Bat ACGC was mixed with disaggregated ovaries from a transgenic mouse that expressed green fluorescent protein. The in vitro reconstruction of the re-aggregates was evaluated. We examined the viability, integration, cellular interaction and ovarian morphogenesis by detecting the expression of Vasa, pH3, Cx43 and Laminin. Our results showed that the interaction between ovarian cells is carried out in the adult ovary of two species, without them losing their capacity to form follicular structures, even after having been enzymatically dissociated.

Frequent EGFR expression/EGFR amplification and lack of activating mutation in testicular choriocarcinoma

Choriocarcinoma (CC) is the rarest but most aggressive histological component of adult testicular germ cell tumor (TGCT). Although we previously reported a putative role of epidermal growth factor receptor (EGFR) alterations in the progression of CC, little is known about the kinase-activating mutation status of EGFR, which predicts the response to EGFR-tyrosine kinase inhibitors. In this study, we clinicopathologically reviewed a total of 12 cases of mixed TGCTs with CC components. Immunohistochemistry, fluorescence in situ hybridization, and direct sequencing was performed to investigate EGFR expression, EGFR copy number alterations, and functional mutation of EGFR in these CC components, respectively. Four (33%) of 12 cases exhibited predominant CC components (>50%), and all these patients died due to disease within 62 months. Overexpression of EGFR, higher copy number of EGFR, and amplification of EGFR was observed in 12 (100%), 10 (83%), and 9 (75%) of 12 CC components, respectively. None of the cases showed any mutational events in exons 18 to 24, which encode the tyrosine kinase domain of EGFR. These results confirm an important role of EGFR in the tumor aggressiveness of testicular CCs and may suggest its possible innate resistance against conventional anti-EGFR therapies.

A rare case of adult Mixed Germ Cell Tumor of Head and Neck

Germ cells tumors most frequently occur in the gonads. Extra gonadal localization is rare and occurs mainly in the mediastinum, retro peritoneum and pineal gland. There are case reports and case series in children of primary head and neck region mixed germ cell tumors. These are even rarer in adults. We present a rare case of an adult patient with a mixed germ cell tumor located primarily in the head and neck region diagnosed after a complete neck dissection. A 40 years old male presented with left sided submandibular swelling and bleeding per mouth. Initial biopsy revealed mucoepidermoid carcinoma but final histopathology reported mixed germ cell tumor after complete left neck dissection. There was no residual disease on the post-operative scans. He was treated with two lines of chemotherapy regimens followed by palliative radiotherapy with some clinical benefit. He is currently on active surveillance.

Visualization and Quantification of Transposon Activity in Caenorhabditis elegans RNAi Pathway Mutants.

RNA silencing pathways play critical roles in maintaining quiescence of transposons in germ cells to promote genome integrity. However the precise mechanism by which different types of transposons are recognized by these pathways is not fully understood. Furthermore, the location in the germline where this transposition occurs after disruption of transposon silencing was previously unknown. Here we utilize the spatial and temporal organization of the Caenorhabditis elegans germline to demonstrate that transposition of DNA transposons in RNA silencing pathway mutants occur in all stages of adult germ cells. We further demonstrate that the double-strand breaks generated by transposons can restore homologous recombination in a mutant defective for the generation of meiosis-specific double-strand breaks. Finally, we detected clear differences in transposase expression and transposon excision between distinct branches of the RNA silencing pathway, emphasizing that there are multiple mechanisms by which transposons can be recognized and routed for small-RNA-mediated silencing.

Investigation of VASA Gene and Protein Expression in Neonate and Adult Testicular Germ Cells in Mice In Vivo and In Vitro.

Objective We aimed to examine the expression levels of the VASA gene and protein in testis sections of neonate and adult mice as well as testicular cell cultures. Materials and Methods In this experimental study, in order to investigate the expression of this germ cell marker gene in more detail, we analyzed the expression of VASA by immunocytochemistry, immunohistochemistry and fluidigm reverse transcription-polymerase chain reaction (RT-PCR). Results The immunohistochemical assays showed that the VASA protein was exclusively expressed in germ cells in the seminiferous tubules of the neonate and adult testis and not in somatic cells. VASA was not detectable in PLZF positive spermatogonial stem cells (SSCs), was weakly expressed in proliferating spermatogonia, and became abundant in spermatocytes and round spermatozoa. Counting VASA-positive cells in the seminiferous tubules of the neonate and adult testis depicted significant higher expression (P<0.05) of VASA in the adult testis in comparison to its neonate counterpart. SSC colonies were established in vitro after digestion of the testis and characterized by immunocytochemistry for CD90 and stage-specific embryonic antigens 3 (SSEA3). Immunocytochemistry confirmed that in contrast to the not detectable signal in vivo, VASA protein was strongly localized in the cytoplasm of both neonate and adult mouse SSCs under in vitro conditions. The results of Fluidigm RT-PCR revealed a significant higher expression of the germ cell gene VASA in adult SSCs in comparison to neonate SSCs in cell culture (P<0.05). ConclusionThe VASA protein is, therefore, an extremely specific marker of testicular germ cell differentiation in vivo and mostly expressed in the adult testis in spermatocytes and round spermatids. The immunohistochemical signal in spermatogonia is very low. So, PLZF positive SSCs are negative for VASA in vivo, while in contrast, once isolated from the testicular niche VASA is also strongly expressed in SSCs under in vitro conditions.

GCT-06 - Overlapping genetic aetiology in adult and paediatric germ cell tumours

GCT-06 - Overlapping genetic aetiology in adult and paediatric germ cell tumours

GCT-45 - Insights into the mechanisms of expression and (specific) secretion of microRNA (-371a-3p) in malignant paediatric and adult germ cell tumours: towards a clinical applicable protocol

GCT-45 - Insights into the mechanisms of expression and (specific) secretion of microRNA (-371a-3p) in malignant paediatric and adult germ cell tumours: towards a clinical applicable protocol

Current research on pediatric and adult germ cell tumors : Areport from the first "Düsseldorfer Testis Cancer Day"

Current research on pediatric and adult germ cell tumors : Areport from the first "Düsseldorfer Testis Cancer Day"

Comparative studies on duplicated tdrd7 paralogs in teleosts: Molecular evolution caused neo-functionalization

The third-round whole genome duplication (3R-WGD) event occurred in the stem lineage of teleost during evolution, and is considered to be responsible for the biological diversification of ray-finned fishes. TUDOR domain containing protein 7 (Tdrd7), which belongs to the Tudor family proteins has been widely discussed in mammals. However, information about this gene in teleost is still lacking. In this study, two teleost tdrd7 genes (tdrd7a and tdrd7b) were identified in the transcriptome of Japanese flounder (Paralichthys olivaceus). Through genomic structure, phylogenetic, synteny analysis and online bioinformatic mining of tdrd7 duplications in other selected species, we confirmed that tdrd7a/7b were originated from the teleost-specific 3R-WGD. The tdrd7a is specific to teleost except for spotted gar. The tdrd7a showed a higher molecular evolution rate than tdrd7b with longer branch-length in the phylogenetic tree and multiple positively selected sites. Interestingly, it showed gonad specific expression pattern in adult tissues and germ cell specific distribution in embryos and gonads. Its 3′-untranslated region (3′UTR) labeled eGFP/DsRED could visualize primordial germ cells (PGCs) in zebrafish embryos. The tdrd7b did not show similar tissue and cell type specificity. These characteristic differences between the duplicated tdrd7 paralogues suggest that tdrd7a and tdrd7b have undergone neofunctionalization in Japanese flounder. Our results provide novel insight into the evolution and functional diversification of teleost tdrd7 genes deserving further investigations.

A Huge Intraabdominal Lump in a Male Patient of 32 Year with Congenital Absence of Left Testis - A Case Report

Undescended testis is a common risk factor for the testicular neoplasm. The risk of malignancy in an undescended testis is highest when the testis lies in the abdomen. It usually presents with a painless intraabdominal lump. Seminoma is the most common adult germ cell tumour of testis whereas Yolk sac tumour in seen in the pediatric age group. Pure yolk sac testicular tumor in an adult is extremely uncommon. Here we present a case where an adult male presented to us with a painless left sided intraabdominal lump with undescended testis on the same side was previously diagnosed as metastatic adenocarcinoma of unknown primary. In a private hospital he received three cycles of chemotherapy; but the lump did not reduce in size and he was reffered to our care for better management. The lump was excised and histopathological report revealed yolk sac tumour of left testis which is a rare presentation in adult.&#x0D; J Shaheed Suhrawardy Med Coll, December 2018, Vol.10(2); 115-117

The Expression of Human Telomerase Reverse Transcriptase in Adult Acute Myeloid Leukemia and Its Correlation With Various Clinico-Pathological Parameters

BACKGROUND: Acute myeloid leukemia (AML) is a heterogeneous disorder characterized by clonal expansion of myeloid progenitors (blasts) in the bone marrow and peripheral blood, AML accounts for 80% of acute leukemia in adults, its incidence increase with age. AML can be a fatal disease so research to predict prognosis is important. Telomerase (TA) is an enzyme that stabilizes the telomere length and makes the cell immortal. It is present in some of the normal cells, fetal cells, adult germ cells, and presents in 85% of tumors in humans, it has been shown that TA can be used as a prognostic marker in some solid and hematological neoplasms. Telomere length is a factor that predicts telomere function.&#x0D; &#x0D; AIM: We test the quantitative amount of human telomerase reverse transcriptase (hTERT) gene expression in AML (diagnosed according to FAB) adult and its correlation with various clinic-pathological parameters.&#x0D; &#x0D; PATIENTS &amp;amp; METHODS: We used the TRAP assay to assess the hTERT gene expression in mononuclear blood cells from 40 newly diagnosed AML patients, 25 AML patients after completing their course of treatment, and 15 control health subjects.&#x0D; &#x0D; RESULTS: The mean value of hTERT in AML and control groups were [1.59 &amp;plusmn; 1.27 anm and 0.035 &amp;plusmn; 0.046 anm respectively], and this difference was significantly higher in patients than in control group (p = 0.0001). The telomerase activity was positive in 27 (67.5%) AML patients, while 13 (32.5%) AML patients were negative for telomerase activity. Twenty-five patients after induction chemotherapy were followed up by bone marrow and peripheral blood examination to determine the patient&amp;rsquo;s response to therapy. Complete hematological remission was achieved in 12 (48.0%) patients and incomplete hematological remission in 13 (52.0%) patients (14%). The hTERT level was significantly higher in patients before induction chemotherapy than after completion of the induction course (p = 0.0001). The hTERT level at diagnosis in patients who did not achieve complete hematological remission was significantly higher than that in patients who achieved complete hematological remission (p = = 0.026). The hTERT level after induction therapy was significantly higher in patients who did not achieve complete hematological remission than in patients who achieved complete hematological remission (p = 0.003).&#x0D; &#x0D; CONCLUSION: Our research suggests that the hTERT expression could serve as a prognostic marker for AML patients.&amp;nbsp;

Targeting RNA helicase DDX3 in stem cell maintenance and teratoma formation.

DDX3 is an RNA helicase that has antiapoptotic properties, and promotes proliferation and transformation. Besides the role of DDX3 in transformed cells, there is evidence to indicate that DDX3 expression is at its highest levels during early embryonic development and is also expressed in germ cells of adults. Even though there is a distinct pattern of DDX3 expression during embryonic development and in adults, very little is known regarding its role in embryonic stem cells and pluripotency. In this work, we examined the relationship between DDX3 and human embryonic stem cells and its differentiated lineages. DDX3 expression was analyzed by immunohistochemistry in human embryonic stem cells and embryonal carcinoma cells. From the data obtained, it was evident that DDX3 was overexpressed in undifferentiated stem cells compared to differentiated cells. Moreover, when DDX3 expression was abrogated in multiple stem cells, proliferation was decreased, but differentiation was facilitated. Importantly, this resulted in reduced potency to induce teratoma formation. Taken together, these findings indicate a distinct role for DDX3 in stem cell maintenance.