• 제목/요약/키워드: Germ cell

검색결과 523건 처리시간 0.033초

Tra2${\alpha}$ and hnRNP K might be Functional Partners of Rbm for Regulation of RNA Processes during Spermatogenesis

  • Lee, Jungmin;Kim, Euisu;Jang, Sung Key;Rhee, Kunsoo
    • Animal cells and systems
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    • 제8권1호
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    • pp.65-70
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    • 2004
  • Rbm is a male infertility gene located in the AZFb region of the Y chromosome. Expression pattern of Rbm indicates that Rbm is critical for early phase of male germ cell development. It shares strong structural homology with hnRNP G, suggesting a function as an RNA processing factor. In order to gain a clue on the molecular mechanisms of Rbm on male germ cell development, we examined interactions of Rbm with selected proteins in yeast. The results revealed specific interactions between Rbm, hnRNP K and Tra2${\alpha}$. These results suggest that hnRNP K and Tra2${\alpha}$ may be functional partners of Rbm in male germ cells. We propose a model in which hnRNP K may playa role as a platform for Rbm and Tra2${\alpha}$.

Sacrococcygeal Teratoma : A Tumor at the Center of Embryogenesis

  • Phi, Ji Hoon
    • Journal of Korean Neurosurgical Society
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    • 제64권3호
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    • pp.406-413
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    • 2021
  • Sacrococcygeal teratoma (SCT) is an extragonadal germ cell tumor (GCT) that develops in the fetal and neonatal periods. SCT is a type I GCT in which only teratoma and yolk sac tumors arise from extragonadal sites. SCT is the most common type I GCT and is believed to originate through epigenetic reprogramming of early primordial germ cells migrating from the yolk sac to the gonadal ridges. Fetal SCT diagnosed in utero presents many obstetrical problems. For high-risk fetuses, fetal interventions (devascularization and debulking) are under development. Most patients with SCT are operated on after birth. Complete surgical resection is the key for tumor control, and the anatomical location of the tumor determines the surgical approaches. Incomplete resection and malignant histology are risk factors for recurrence. Approximately 10-15% of patients have a tumor recurrence, which is frequently of malignant histology. Long-term surveillance with monitoring of serum alpha fetoprotein and magnetic resonance imaging is required. Survivors of SCT may suffer anorectal, urological, and sexual sequelae later in their life, and comprehensive evaluation and care are required.

A Novel Feeder-Free Culture System for Expansion of Mouse Spermatogonial Stem Cells

  • Choi, Na Young;Park, Yo Seph;Ryu, Jae-Sung;Lee, Hye Jeong;Arauzo-Bravo, Marcos J.;Ko, Kisung;Han, Dong Wook;Scholer, Hans R.;Ko, Kinarm
    • Molecules and Cells
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    • 제37권6호
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    • pp.473-479
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    • 2014
  • Spermatogonial stem cells (SSCs, also called germline stem cells) are self-renewing unipotent stem cells that produce differentiating germ cells in the testis. SSCs can be isolated from the testis and cultured in vitro for long-term periods in the presence of feeder cells (often mouse embryonic fibroblasts). However, the maintenance of SSC feeder culture systems is tedious because preparation of feeder cells is needed at each subculture. In this study, we developed a Matrigel-based feeder-free culture system for long-term propagation of SSCs. Although several in vitro SSC culture systems without feeder cells have been previously described, our Matrigel-based feeder-free culture system is time- and cost-effective, and preserves self-renewability of SSCs. In addition, the growth rate of SSCs cultured using our newly developed system is equivalent to that in feeder cultures. We confirmed that the feeder-free cultured SSCs expressed germ cell markers both at the mRNA and protein levels. Furthermore, the functionality of feeder-free cultured SSCs was confirmed by their transplantation into germ cell-depleted mice. These results suggest that our newly developed feeder-free culture system provides a simple approach to maintaining SSCs in vitro and studying the basic biology of SSCs, including determination of their fate.

Identification and Characterization of Rodent Germ Cells-Specific Hyaluronidases

  • Kim, Ekyune;Chang, Kyu-Tae
    • Reproductive and Developmental Biology
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    • 제36권3호
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    • pp.155-161
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    • 2012
  • Germ cell-specific hyaluronidases such as sperm adhesion molecule 1 (SPAM1) and hyaluronoglucosaminidase 5 (Hyal5) are in part responsible for dispersal of the cumulus cell mass, which is a critical step in establishing fertilization in mammals. In this study, we identified two testis-hyaluronidases, SPAM1 and Hyal5, in hamster and rat. These two genes were expressed specifically in the testis. At the protein level, hamster SPAM1 and Hyal5 display 78.7% and 75.4% identity with mouse SPAM1 and Hyal5. Further, the activity of the enzymes with respect to cumulus cell dispersion did not differ, although we observed that the enzymatic activity differed in pH range. These studies suggest that different sperm hyaluronidases are capable of dispersing the cumulus cell mass despite differences in enzyme activity.

New strategies for germ cell cryopreservation: Cryoinjury modulation

  • Sang-Eun Jung;Buom-Yong Ryu
    • Clinical and Experimental Reproductive Medicine
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    • 제50권4호
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    • pp.213-222
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    • 2023
  • Cryopreservation is an option for the preservation of pre- or post-pubertal female or male fertility. This technique not only is beneficial for human clinical applications, but also plays a crucial role in the breeding of livestock and endangered species. Unfortunately, frozen germ cells, including oocytes, sperm, embryos, and spermatogonial stem cells, are subject to cryoinjury. As a result, various cryoprotective agents and freezing techniques have been developed to mitigate this damage. Despite extensive research aimed at reducing apoptotic cell death during freezing, a low survival rate and impaired cell function are still observed after freeze-thawing. In recent decades, several cell death pathways other than apoptosis have been identified. However, the relationship between these pathways and cryoinjury is not yet fully understood, although necroptosis and autophagy appear to be linked to cryoinjury. Therefore, gaining a deeper understanding of the molecular mechanisms of cryoinjury could aid in the development of new strategies to enhance the effectiveness of the freezing of reproductive tissues. In this review, we focus on the pathways through which cryoinjury leads to cell death and propose novel approaches to enhance freezing efficacy based on signaling molecules.

Clinical Profile, Treatment and Survival Outcome of Testicular Tumors: A Pakistani Perspective

  • Bhatti, Abu Bakar Hafeez;Ahmed, Irfan;Ghauri, Rashid Khan;Saeed, Qamar;Mir, Khurram
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권1호
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    • pp.277-280
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    • 2014
  • Background: Testicular cancer management is considered a marvel of modern science with excellent treatment results. Pakistan has a distinct ethnic variation and geographic distribution but data regarding clinical presentation of testicular tumors and their management is under reported. The objective of this study was to determine clinical profile, treatment modalities and survival outcome of testicular tumors in the Pakistani population. Materials and Methods: A retrospective review of patients who received treatment for testicular cancer at Shaukat Khanum Cancer Hospital from January 2009 to December 2012 was performed. Patient demographics, clinical features at presentation and treatment modalities were assessed. For categorical variables chi square test was used. Survival was calculated using Kaplan Meier survival curves and Log rank test was employed to determine significance. Results: The most common tumor was mixed germ cell tumor in 49% patients. For all tumor variants except seminoma, stage III was the most common clinical stage at presentation. Majority of patients with non seminomatous germ cell tumors presented in the15-30 year age group as compared to seminoma which was most prevalent in the 30-40 year age group. Orchiectomy followed by chemotherapy was the most common treatment modality in 80% patients. Expected 5 year survival for seminomas and non-seminomatous germ cell tumors was 96% and 90% respectively which was not significantly different (p=0.2). Conclusions: Despite a distinct clinical profile of testicular tumors in Pakistani population, survival is comparable with published reports.

Understanding the Treatment Strategies of Intracranial Germ Cell Tumors : Focusing on Radiotherapy

  • Kim, Joo-Young;Park, Jeonghoon
    • Journal of Korean Neurosurgical Society
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    • 제57권5호
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    • pp.315-322
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    • 2015
  • Intracranial germ cell tumors (ICGCT) occur in 2-11% of children with brain tumors between 0-19 years of age. For treatment of germinoma, relatively low radiation doses with or without chemotherapy show excellent 10 year survival rate of 80-100%. Past studies showed that neoadjuvant chemotherapy combined with focal radiotherapy resulted in unacceptably high rates of periventricular tumor recurrence. The use of generous radiation volume which covers the whole ventricular space with later boost treatment to primary site is considered as standard treatment of intracranial germinomas. For non-germinomatous germ cell tumors (NGGCT), 10-year overall survival rate is still much inferior than that of intracranial germinoma despite intensive chemotherapy and high-dose radiotherapy. Craniospinal radiotherapy combined with cisplatin-based chemotherapy provides the best treatment outcome for NGGCT; 60-70% of overall survival rate. There is a debate on the surgical role whether surgery can contribute to improved treatment outcome of NGGCT when added to combined chemoradiotherapy. Because higher dose of radiotherapy is required for treatment of NGGCT than for germinoma, it is tested whether whole ventricular irradiation can replace craniospinal irradiation in intermediate risk group of NGGCT to minimize radiation-related late toxicity in the recent studies. To minimize the treatment-related neural deficit and late sequelae while maintaining long-term survival rate of ICGCT patients, optimized administration of chemotherapy and radiotherapy should be selected. Use of technically upgraded radiotherapy modalities such as intensity-modulated radiotherapy or proton beam therapy is expected to bring an improved neurocognitive outcome with longitudinal assessment of the patients.

Clinicopathological Features and Survival of Young Turkish Patients with Testicular Germ Cell Tumors

  • Ozgun, Alpaslan;Karagoz, Bulent;Tuncel, Tolga;Emirzeoglu, Levent;Celik, Serkan;Bilgi, Oguz
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권11호
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    • pp.6889-6892
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    • 2013
  • Background: Testicular germ cell tumors (TGCTs) are a relatively common malignancy in young men. The aim of this study was to investigate the clinicopathological features and survival of young Turkish patients with TGCT. Materials and Methods: In this retrospective study, the clinical and pathological characteristics of young Turkish patients with TGCT who were monitored by the Department of Medical Oncology of a military hospital between 2008 and 2013 were investigated. Overall survival data were analyzed. Results: Ninety-six patients were included in the study. The mean age was 26.4 years. Among the patients, 17.7% had seminoma and 43.8% had mixed non-seminomatous germ cell tumors. Some 46.9% were Stage I, 30.2% were Stage II, and 22.9 were Stage III. Of the patients, 83.3% received chemotherapy, 25% underwent retroperitoneal lymph node dissection (RPLND), 3.1% received radiotherapy, and 12.5% were followed-up without treatment. In addition, 18.8% of the patients were administered salvage chemotherapy due to relapse or progression. The 5-year overall survival rate was 90.2% for all patients. The 2-year overall survival rate was 100% for Stage I patients, 94% for Stage II patients, and 70.2% for Stage III patients. The difference between the survival curves of stages was statistically significant (p=0.029). Conclusions: In young Turkish patients with TGCT, good results were obtained with appropriate treatment, most receiving chemotherapy. The prognosis of the disease was good even in the advanced stage.

Germ Cell Differentiations during Spermatogenesis and Taxonomic Values of Mature Sperm Morphology of $Atrina$ ($Servatrina$) $pectinata$ (Bivalvia, Pteriomorphia, Pinnidae)

  • Kang, Hee-Woong;Chung, Ee-Yung;Kim, Jin-Hee;Chung, Jae-Seung;Lee, Ki-Young
    • 한국발생생물학회지:발생과생식
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    • 제16권1호
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    • pp.19-29
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    • 2012
  • The ultrastructural characteristics of germ cell differentiations during spermatogenesis and mature sperm morphology in male $Atrina$ ($Servatrina$) $pectinata$ were evaluated via transmission electron microscopic observation. The accessory cells, which contained a large quantity of glycogen particles and lipid droplets in the cytoplasm, are assumed to be involved in nutrient supply for germ cell development. Morphologically, the sperm nucleus and acrosome of this species are ovoid and conical in shape, respectively. The acrosomal vesicle, which is formed by two kinds of electron-dense or lucent materials, appears from the base to the tip: a thick and slender elliptical line, which is composed of electron-dense opaque material, appears along the outer part (region) of the acrosomal vesicle from the base to the tip, whereas the inner part (region) of the acrosomal vesicle is composed of electron-lucent material in the acrosomal vesicle. Two special characteristics, which are found in the acrosomal vesicle of A. ($S$) $pectinata$ in Pinnidae (subclass Pteriomorphia), can be employed for phylogenetic and taxonomic analyses as a taxonomic key or a significant tool. The spermatozoa were approximately $45-50{\mu}m$ in length, including a sperm nucleus (about $1.43{\mu}m$ in length), an acrosome (about $0.51{\mu}m$ in length), and a tail flagellum (about $46-47{\mu}m$). The axoneme of the sperm tail evidences a 9+2 structure.