• BMB Reports
• /
• v.45 no.8
• /
• pp.427-432
• /
• 2012

Primary cilia, single hair-like appendage on the surface of the most mammalian cells, were once considered to be vestigial cellular organelles for a past century because of their tiny structure and unknown function. Although they lack ancestral motility function of cilia or flagella, they share common ground with multiciliated motile cilia and flagella on internal structure such as microtubule based nine outer doublets nucleated from the base of mother centrioles called basal body. Making cilia, ciliogenesis, in cells depends on the cell cycle stage due to reuse of centrioles for cell division forming mitotic spindle pole (M phase) and assembling cilia from basal body (starting G1 phase and maintaining most of interphase). Ciliary assembly required two conflicting processes such as assembly and disassembly and balance between these two processes determines the length of cilia. Both process required highly conserved transport system to supply needed substance to grow tip of cilia and bring ciliary turnover product back to the base of cilia using motor protein, kinesin and dynein, and transport protein complex, IFT particles. Disruption of ciliary structure or function causes multiple human disorder called ciliopathies affecting disease of diverse ciliated tissues ranging from eye, kidney, respiratory tract and brain. Recent explosion of research on the primary cilia and their involvement on animal development and disease attracts scientific interest on how extensively the function of cilia related to specific cell physiology and signaling pathway. In this review, I introduce general features of primary cilia and recent progress in understanding of the ciliary length control and signaling pathways transduced through primary cilia in vertebrates.

• The Korean Journal of Cytopathology
• /
• v.11 no.1
• /
• pp.59-63
• /
• 2000

Extraskeletal osteosarcoma is an uncommon tumor originated from soft tissue without evidence of skeletal involvement. It usually affects adults and its common locations are extremity, buttock, and retroperitoneum. Although the histologic feature of this tumor is well known, there have been few reports on the fine needle aspiration cytologic findings. We report the imprint cytologic feature of extraskeletal osteosarcoma. The patient was a 49-year-old man with a mass of the left anterior chest for 2 years. On the Imprint preparation, the smears showed malignant round, polygonal or spindle cells with coarsely clumped chromatin and occasionally prominent nucleoli. The malignant cells occur singly, in clusters, or associated with amorphous eosinophilic osteoid. Mitotic figures are also seen.

• ALGAE
• /
• v.25 no.4
• /
• pp.197-204
• /
• 2010

Cytoskeletal changes were observed during cell division of the green alga Zygnema cruciatum using flourescein isothiocynate (FITC)-conjugated phallacidin for F-actin staining and FITC-anti-$\alpha$-tubulin for microtubule staining. Z. cruciatum was uninucleate with two star-shaped chloroplasts. Nuclear division and cell plate formation occurred prior to chloroplast division. Actin filaments appeared on the chromosome and nuclear surface during prophase, and the F-actin ring appeared as the cleavage furrow developed. FITC-phallacidin revealed that actin filaments were attached to the chromosomes during metaphase. The F-actin ring disappeared at late metaphase. At telophase, FITC-phallacidin staining of actin filaments disappeared. FITC-anti-$\alpha$-tubulin staining revealed that microtubules were arranged beneath the protoplasm during interphase and then localized on the nuclear region at prophase, and that the mitotic spindle was formed during metaphase. The microtubules appeared between dividing chloroplasts. The results indicate that a coordination of actin filaments and microtubules might be necessary for nuclear division and chromosome movement in Z. cruciatum.

• BMB Reports
• /
• v.47 no.5
• /
• pp.249-255
• /
• 2014

Polo-like kinase-1 (Plk1) belongs to a family of serine-threonine kinases and plays a critical role in mitotic progression. Plk1 involves in the initiation of mitosis, centrosome maturation, bipolar spindle formation, and cytokinesis, well-reported as traditional functions of Plk1. In this review, we discuss the role of Plk1 during DNA damage response beyond the functions in mitotsis. When DNA is damaged in cells under various stress conditions, the checkpoint mechanism is activated to allow cells to have enough time for repair. When damage is repaired, cells progress continuously their division, which is called checkpoint recovery. If damage is too severe to repair, cells undergo apoptotic pathway. If damage is not completely repaired, cells undergo a process called checkpoint adaptation, and resume cell division cycle with damaged DNA. Plk1 targets and regulates many key factors in the process of damage response, and we deal with these subjects in this review.

• The Korean Journal of Cytopathology
• /
• v.6 no.1
• /
• pp.58-61
• /
• 1995

Fine-needle aspiration (FNA) biopsy has become the procedure of choice for initial diagnosis of adrenal masses. However, there have been relatively few reports discussing the FNA cytologic features of adrenal cortical carcinoma. Recently, we experienced a case of FNA cytology of bilateral adrenal cortical carcinoma in a 61-year old man. The smear revealed loosely cohesive pleomorphic tumor cells with hemorrhagic and necrotic background. The tumor cells showed oval to spindle hyperchromatic nuclei and prominent nucleoli with frequent mitotic figures. The cytoplasm of tumor cells was relatively abundant and sometimes vacuolated. These cytologic findings were interpreted as an ad renal cortical carcinoma, undifferentiated pattern.

• Development and Reproduction
• /
• v.18 no.1
• /
• pp.65-71
• /
• 2014

Cell cycle process is regulated by a number of protein kinases and among them, serine/threonine kinases carry phosphate group from ATP to substrates. The most important three kinase families are Cyclin-dependent kinase (Cdk), Polo-like kinase (Plk), and Aurora kinase. Polo-like kinase family consists of 5 members (Plk1-Plk5) and they are involved in multiple functions in eukaryotic cell division. It regulates a variety of aspects such as, centrosome maturation, checkpoint recovery, spindle assembly, cytokinesis, apoptosis and many other features. Recently, it has been reported that Plks are related to tumor development and over-expressed in many kinds of tumor cells. When injected the anti-Plk antibody into human cells, the cells show aneuploidy, and if inhibit Plks, most of the mitotic cell division does not proceed properly. For that reasons, many inhibitors of Plk have been recently emerged as new target for remedy of the cancer therapeutic research. In this paper, we reviewed briefly the characteristics of Plk families and how Plks work in regulating cell cycles and cancer formation, and the possibilities of Plks as target for cancer therapy.

• Reproductive and Developmental Biology
• /
• v.35 no.4
• /
• pp.499-502
• /
• 2011

Aurora A kinase is a mitotic serine/threonine kinase whose proposed functions include the maturation of centrosomes, G2/M transition, alignment of chromosomes at metaphase, and cytokinesis. In this study, we investigated the effect of MLN8237, an aurora A kinase inhibitor, on the postovulatory aging of oocytes based on the frequency of oocyte fragmentation, cdk1 kinase activity, and cyclin B degradation. The fragmentation of ovulated oocytes during prolonged culture was inhibited by treatment with MLN8237 in a concentration-dependent manner. The frequency of fragmented oocytes was significantly lower in oocytes treated with 2 ${\mu}M$ MLN8237 (13%) than in control oocytes (64%) after two days of culture. Most of the control (non-fragmented) oocytes (91%) were activated after two days of culture. In comparison, only 22% of the MLN8237-treated oocytes were activated; the rest of the oocytes (78%) were still in metaphase with an abnormal spindle and dispersed chromosomes. Next, cdk1 activity and the level of cyclin B were examined. The level of cyclin B and cdk1 activity in MLN8237-treated oocytes were nearly equal to those in control oocytes. Our results indicate that MLN8237 inhibited the fragmentation of ovulated oocytes during prolonged culture, although it blocked the spontaneous decrease in activity of cdk1 and degradation of cyclin B. This mechanism of inhibition is different from that in oocytes treated with nocodazole, which have high levels of cdk1 activity and cyclin B.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.46 no.4
• /
• pp.282-287
• /
• 2020

Undifferentiated pleomorphic sarcoma (UPS) is a high-grade neoplasm that is usually located in the extremities and retroperitoneum. In the past, UPS was considered the most common soft tissue sarcoma in adults; due to improvements in diagnostic techniques, most cases have been reclassified as other lineage-specific tumors. Gnathic bones are rarely affected, and the clinicopathological characteristics of this neoplasm when diagnosed in the jaw remain to be better described. In this report, we present a rare case of mandibular UPS affecting an 88-year-old female who demonstrated a painful swelling on the right side of the mandible that was accompanied by a pathological fracture. Microscopic examination revealed a pleomorphic spindle-cell neoplasm with mitotic figures and necrosis. The patient underwent surgery and adjuvant radiotherapy but experienced metastasis after 12 months of follow-up and died. Diagnosis of UPS is challenging, and oral pathologists must be aware of this entity when dealing with aggressive undifferentiated neoplasms.

• Korean Journal of Veterinary Research
• /
• v.46 no.3
• /
• pp.275-278
• /
• 2006

A 7-month-old brown pig with a discoid and pedunculate mass measuring $14.0{\times}12.5{\times}2.5cm$ on the skin of the right shoulder was noted at the slaughter house in Jeju. The surface of mass approximately $7{\times}4cm$ was interfaced with skin. The color of mass with firm consistency was mainly black and partially white on cut surface. Histopathologically, numerous unencapsulated endocrine-like cellular nodules of epithelioid cell type with abundant intracytoplasmic black pigment, melanin, were occupied in dermis and subcutis. Most of nodules in deep dermis were surrounded by lightly pigmented spindle cells and loose fibrous tissues. Mitotic figures were infrequently observed. The overlying epidermis was hyperplastic due to the down-growth of rete peg. Based on the gross and histopathologic findings, this case was diagnosed as cutaneous melanoma. In our best knowledge, this is the first case of swine cutaneous melanoma in Korea.

• Archives of Craniofacial Surgery
• /
• v.15 no.1
• /
• pp.43-46
• /
• 2014

Nodular fasciitis is a reactive, non-neoplastic lesion that is most commonly found in the subcutaneous or superficial fascia of the extremities and trunk. Head and neck lesions are relatively uncommon and reports vary from 7% to 15% depending on the authors. Nodular fasciitis grows quickly, and shows a pleomorphic spindle cell pattern with increased mitotic activity. Such factors lead to cases where the lesion is mistaken for a malignancy such as fibrosarcoma and the case may end up with unnecessarily aggressive treatments. The intent of this paper is to report a relatively rare case of nodular fasciitis occurring in the periorbital area and also to highlight the importance of accurate diagnosis and non-aggressive management of this benign lesion.