• Title/Summary/Keyword: Proliferating cell nuclear antigen

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Cell clusters in intervertebral disc degeneration: an attempted repair mechanism aborted via apoptosis

  • Polly Lama;Jerina Tiwari;Pulkit Mutreja;Sukirti Chauhan;Ian J Harding;Trish Dolan;Michael A Adams;Christine Le Maitre
    • Anatomy and Cell Biology
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    • v.56 no.3
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    • pp.382-393
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    • 2023
  • Cell clusters are a histological hallmark feature of intervertebral disc degeneration. Clusters arise from cell proliferation, are associated with replicative senescence, and remain metabolically, but their precise role in various stages of disc degeneration remain obscure. The aim of this study was therefore to investigate small, medium, and large size cell-clusters. For this purpose, human disc samples were collected from 55 subjects, aged 37-72 years, 21 patients had disc herniation, 10 had degenerated non-herniated discs, and 9 had degenerative scoliosis with spinal curvature <45°. 15 non-degenerated control discs were from cadavers. Clusters and matrix changes were investigated with histology, immunohistochemistry, and Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Data obtained were analyzed with spearman rank correlation and ANOVA. Results revealed, small and medium-sized clusters were positive for cell proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) in control and slightly degenerated human discs, while large cell clusters were typically more abundant in severely degenerated and herniated discs. Large clusters associated with matrix fissures, proteoglycan loss, matrix metalloproteinase-1 (MMP-1), and Caspase-3. Spatial association findings were reconfirmed with SDS-PAGE that showed presence to these target markers based on its molecular weight. Controls, slightly degenerated discs showed smaller clusters, less proteoglycan loss, MMP-1, and Caspase-3. In conclusion, cell clusters in the early stages of degeneration could be indicative of repair, however sustained loading increases large cell clusters especially around microscopic fissures that accelerates inflammatory catabolism and alters cellular metabolism, thus attempted repair process initiated by cell clusters fails and is aborted at least in part via apoptosis.

Effect of Sofosbuvir on rats' ovaries and the possible protective role of vitamin E: biochemical and immunohistochemical study

  • Neven A. Ebrahim;Hussein Abdelaziz Abdalla;Neimat Abd Elhakam Yassin;Aya Elsayed Maghrabia;Amira Ibrahim Morsy
    • Anatomy and Cell Biology
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    • v.56 no.4
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    • pp.526-537
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    • 2023
  • Hepatitis C virus (HCV) infection is a major health problem worldwide and its eradication is mandatory. Direct acting HCV polymerase inhibitors, such as Sofosbuvir (SOF), is an effective regimen. However, it has some side effects like mutagenesis, carcinogenesis, and the impairment of testicular function. It is important to evaluate the safety of SOF on the ovary, as there are no studies yet. Increasing the production of Reactive Oxygen Species (ROS), causes oxidative stress, which affects ovulation process, female reproduction, and fertility. Accumulation of SOF in the cells was demonstrated to promote ROS generation. Vitamin E (Vit E) is an antioxidant agent that has an essential role in the female reproductive system, its deficiency can cause infertility. We explored the effect of SOF treatment alone and co-treated with Vit E on ovarian ROS level and ovarian morphology experimentally using biochemical and immunohistochemical studies. Significant changes in oxidative stress markers; nitric oxide and malondialdehyde lipid peroxidation, antioxidant enzymes; catalase, super oxide dismutase, and reduced glutathione, proliferating markers; proliferation cell nuclear antigen and Ki-67 antigen and caspase 3 apoptotic marker were demonstrated. It was shown that where SOF induced oxidative stress, it also aggravated ovarian dysfunction. The essential role of Vit E as an antioxidant agent in protecting the ovarian tissue from the effect of oxidative stress markers and preserving its function was also displayed. This could be guidance to add Vit E supplements to SOF regimens to limit its injurious effect on ovarian function.

Busulfan Inhibits PCNA Expression but Induces The Expression of pRB

  • 천영신;주학진;권득남;김진희
    • Proceedings of the KSAR Conference
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    • 2001.03a
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    • pp.21-21
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    • 2001
  • 일반적으로 세포는 방사능이나 항암제 등의 자극에 의해 DNA가 손상받았을 때 DNA를 합성하기 전, DNA변이를 복구하기 위해 cell cycle을 정지시키게 된다. pRB(retinoblatoma protein)는 이러한 cell cycle의 조절기작에서 중요한 역할을 담당하는 것으로 알려져 있다. G1기에서 S기로 진행하는 것을 조절하는 단백질인 pRB 은 E2F(cell cycle transcription factor)와 상호작용하여 cell cycle 진행에 필요한 전사활성을 억제, PCNA (proliferating cell nuclear antigen)의 합성을 저해한다. 또한, E2F와 결합된 pRB는 apoptosis를 제어하는 유전자를 조절하는 것으로 알려져 있다. Cell cycle에 영향을 미치는 항암제의 일종인 busulfan을 처리하면, 정소 내에 존재하는 대부분의 생식세포들은 사멸되고 spermatogonia만 남는 것으로 알려져 있다. 그러나 그 기작에 대해서는 자세히 연구된 바가 없다. 본 연구에서는 busulfan처리시 spermatogonial stem cell이 어떤 기작에 의해 손상받지 않고 유지되는지를 알아보고자 실험을 수행하였다. Busulfan을 처리한 마우스 (항암제 투여 후 5주)와 정상적인 13주령의 마우스의 정소로부터 각각 세포를 분리하였다. LSC (laser scanning cytometry)를 이용하여 처리군(busulfan treated mice)과 대조군(normal mature mice)에 대해 각각 DNA함량을 비교ㆍ분석한 결과 G0/G1(2N)에 머물러 있는 세포비율이 처리군에서 현저하게 증가했다 (79.3$\pm$5.5%:8.1$\pm$1.3%). Cell cycle의 G1/S check point인 pRB와 PCNA 발현을 Western blot과 면역조직학적인 방법(immunohisto-chemistry)을 이용하여 조사하였다 PCNA는 대조군과 비교해, 처리군에서 매우 낮은 수준으로 발현되었다. 면역염색된 정소단면을 살펴보면, 대조군에서는 모든 세정관에서 PCNA를 발현하는 세포가 높은 비율로 검출되었고, 처리군에서는 소수의 세정관에서 세포들이 낮은 수준으로 검출되었다. 반면에, pRB의 경우 PCNA와는 상반된 결과를 나타내어, 대조군에서는 거의 발현이 되지 않는 반면, 처리군에서는 대부분의 세정관내, 기저막을 따라 위치한 세포들에서 발현되었다. 이상의 결과는 busulfan에 의해 pRB의 인산화가 억제, pRB 와 결합된 E2F는 전사 활성이 억제되어, PCNA 합성을 저해하는 것으로 설명되어질 수 있다. 결론적으로, 인산화가 억제된 pRB (underphosphorylated RB protein)이 quiescent spermatogonial stem cell에서만 특이하게 발현하는 단백질이며, 이러한 pRB의 발현은 apoptosis를 제어하는 역할을 담당해 busulfan처리에 의해 손상받지 않고 남아있는 것으로 시사된다.

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RNA Interference-Mediated Knockdown of Astrocyte Elevated Gene-1 Inhibits Growth, Induces Apoptosis, and Increases the Chemosensitivity to 5-Fluorouracil in Renal Cancer Caki-1 Cells

  • Wang, Peng;Yin, Bo;Shan, Liping;Zhang, Hui;Cui, Jun;Zhang, Mo;Song, Yongsheng
    • Molecules and Cells
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    • v.37 no.12
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    • pp.857-864
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    • 2014
  • Astrocyte elevated gene-1 (AEG-1) is a recently discovered oncogene that has been reported to be highly expressed in various types of malignant tumors, including renal cell carcinoma. However, the precise role of AEG-1 in renal cancer cell proliferation and apoptosis has not been clarified. In this study, we transfected the renal cancer cell line Caki-1 with a plasmid expressing AEG-1 short hairpin RNA (shRNA) and obtained cell colonies with stable knockdown of AEG-1. We found that AEG-1 down-regulation inhibited cell proliferation and colony formation and arrested cell cycle progression at the sub-G1 and G0/G1 phase. Western blot analysis indicated that the expression of proliferating cell nuclear antigen (PCNA), cyclin D1 and cyclin E were significantly reduced following AEG-1 down-regulation. In addition, AEG-1 knockdown led to the appearance of apoptotic bodies in renal cancer cells, and the ratio of apoptotic cells significantly increased. Expression of the antiapoptotic factor Bcl-2 was dramatically reduced, whereas the pro-apoptotic factors Bax, caspase-3 and poly (ADPribose) polymerase (PARP) were significantly activated. Finally, AEG-1 knockdown in Caki-1 cells remarkably suppressed cell proliferation and enhanced cell apoptosis in response to 5-fluorouracil (5-FU) treatment, suggesting that AEG-1 inhibition sensitizes Caki-1 cells to 5-FU. Taken together, our data suggest that AEG-1 plays an important role in renal cancer formation and development and may be a potential target for future gene therapy for renal cell carcinoma.

Gallic Acid Hindered Lung Cancer Progression by Inducing Cell Cycle Arrest and Apoptosis in A549 Lung Cancer Cells via PI3K/Akt Pathway

  • Ko, Eul-Bee;Jang, Yin-Gi;Kim, Cho-Won;Go, Ryeo-Eun;Lee, Hong Kyu;Choi, Kyung-Chul
    • Biomolecules & Therapeutics
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    • v.30 no.2
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    • pp.151-161
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    • 2022
  • This study elucidates the anti-cancer potential of gallic acid (GA) as a promising therapeutic agent that exerts its effect by regulating the PI3K/Akt pathway. To prove our research rationale, we used diverse experimental methods such as cell viability assay, colony formation assay, tumor spheroid formation assay, cell cycle analysis, TUNEL assay, Western blot analysis, xenograft mouse model and histological analysis. Treatment with GA inhibited cell proliferation in dose-dependent manner as measured by cell viability assay at 48 h. GA and cisplatin (CDDP) also inhibited colony formation and tumor spheroid formation. In addition, GA and CDDP induced apoptosis, as determined by the distribution of early and late apoptotic cells and DNA fragmentation. Western blot analysis revealed that inhibition of the PI3K/Akt pathway induced upregulation of p53 (tumor suppressor protein), which in turn regulated cell cycle related proteins such as p21, p27, Cyclin D1 and E1, and intrinsic apoptotic proteins such as Bax, Bcl-2 and cleaved caspase-3. The anti-cancer effect of GA was further confirmed in an in vivo mouse model. Intraperitoneal injection with GA for 4 weeks in an A549-derived tumor xenograft model reduced the size of tumor mass. Injection of them downregulated the expression of proliferating cell nuclear antigen and p-Akt, but upregulated the expression of cleaved caspase-3 in tumor tissues. Taken together, these results indicated that GA hindered lung cancer progression by inducing cell cycle arrest and apoptosis, suggesting that GA would be a potential therapeutic agent against non-small cell lung cancer.

Relationship between Sloan-Kettering Virus Expression and Granulosa Cells of Atretic Follicles in the Rat Ovary

  • Kim, Hyun;Matsuwaki, Takashi;Yamanouchi, Keitaro;Nishihara, Masugi;Kim, Sung-Woo;Ko, Yeoung-Gyu;Yang, Boh-Suk
    • Reproductive and Developmental Biology
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    • v.35 no.3
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    • pp.341-348
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    • 2011
  • Sloan-Kettering virus gene product of a cellular protooncogene c-Ski is an unique nuclear pro-oncoprotein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. The aim of the present study was to locate Ski protein in rat ovaries in order to predict the possible involvement of Ski in follicular development and atresia. First, expression of c-Ski mRNA in the ovaries of adult female rats was confirmed by RT-PCR. Then, ovaries obtained on the day of estrus were subjected to immunohistochemical analysis for Ski and proliferating cell nuclear antigen (PCNA) in combination with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Ski was expressed in granulosa cells that were positive for TUNEL, but negative for PCNA, regardless of the shape and size of follicles. Expression of Ski in TUNEL-positive granulosa cells, but not in PCNA-positive granulosa cells, was also verified in immature hypophysectomized rats having a single generation of developing and atretic follicles by treatment with equine chorionic gonadotropin (eCG). These results indicate that Ski is profoundly expressed in the granulosa cells of atretic follicles, but not in growing follicles, and suggest that Ski plays a role in apoptosis of granulosa cells during follicular atresia.

Murrayafoline A Induces a G0/G1-Phase Arrest in Platelet-Derived Growth Factor-Stimulated Vascular Smooth Muscle Cells

  • Han, Joo-Hui;Kim, Yohan;Jung, Sang-Hyuk;Lee, Jung-Jin;Park, Hyun-Soo;Song, Gyu-Yong;Nguyen, Manh Cuong;Kim, Young Ho;Myung, Chang-Seon
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.5
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    • pp.421-426
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    • 2015
  • The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through $G_0/G_1$ to S phase of the cell cycle, as measured by [$^3H$]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at $G_0/G_1$ phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

Anti-Cancer Effects of Salvia Miltiorrhiza, Carydalis Turtschaminovii, Reynoutria Elliptica Herbal Acupuncture on Solid Tumor of Rats induced by Injection of RK3E-ras Cells (RK3E-ras cells로 유발된 흰쥐의 고형종양에 대한 단삼, 현호색, 호장근 약침의 항종양 효과)

  • Park, Soo-Gon;Shin, Mi-Suk;Choi, Jin-Bong;Kim, Sun-Jong
    • Journal of Korean Medicine Rehabilitation
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    • v.19 no.1
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    • pp.91-102
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    • 2009
  • Objectives : The present study was carried out investigate the anti-cancer effect of Salvia miltiorrhiza, Carydalis turtschaminovii and Reynoutria elliptica herbal acupuncture on solid tumor of rats induced by injection of RK3E-ras cells. Methods : RK3E-ras cells were injected on the right lumbar region of rats. After 1 weeks, the experimental rats were divided into four groups : Control group, Salvia miltiorrhiza herbal acupuncture group(SM), Carydalis turtschaminovii herbal acupuncture group(CT), Reynoutria elliptica herbal acupuncture group(RE). And we investigated the weight and size of tumor tissue, gross anatomy, histological and PCNA immunohistochemical study, hepatic and renal metastasis for tumor of each group. Results : 1. In the weight of tumor tissue assessment, SM and CT's weight of tumor tissue was decreased. 2. In the size of tumor tissue assessment, SM was smaller than any other group. 3. In the histological observation, SM's formation of tunica fibrosa that surround the tumor cell was obvious and vasculature that developes circumference of tumor cell was not observed, and density of tumor cell was very low. 4. In the PCNA immunohistochemical study, Control group, SM, RE showed strong immune response in the central site of tumor tissue. 5. In observation of liver and kidney tissue, we were not able to observe tumor cell in the SM. Conclusions : Consequently, SM and CT showed a inhibition of growth and metastasis.

Ahnak depletion accelerates liver regeneration by modulating the TGF-β/Smad signaling pathway

  • Yang, Insook;Son, Yeri;Shin, Jae Hoon;Kim, Il Yong;Seong, Je Kyung
    • BMB Reports
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    • v.55 no.8
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    • pp.401-406
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    • 2022
  • Ahnak, a large protein first identified as an inhibitor of TGF-β signaling in human neuroblastoma, was recently shown to promote TGF-β in some cancers. The TGF-β signaling pathway regulates cell growth, various biological functions, and cancer growth and metastasis. In this study, we used Ahnak knockout (KO) mice that underwent a 70% partial hepatectomy (PH) to investigate the function of Ahnak in TGF-β signaling during liver regeneration. At the indicated time points after PH, we analyzed the mRNA and protein expression of the TGF -β/Smad signaling pathway and cell cycle-related factors, evaluated the cell cycle through proliferating cell nuclear antigen (PCNA) immunostaining, analyzed the mitotic index by hematoxylin and eosin staining. We also measured the ratio of liver tissue weight to body weight. Activation of TGF-β signaling was confirmed by analyzing the levels of phospho-Smad 2 and 3 in the liver at the indicated time points after PH and was lower in Ahnak KO mice than in WT mice. The expression levels of cyclin B1, D1, and E1; proteins in the Rb/E2F transcriptional pathway, which regulates the cell cycle; and the numbers of PCNA-positive cells were increased in Ahnak KO mice and showed tendencies opposite that of TGF-β expression. During postoperative regeneration, the liver weight to body weight ratio tended to increase faster in Ahnak KO mice. However, 7 days after PH, both groups of mice showed similar rates of regeneration, following which their active regeneration stopped. Analysis of hepatocytes undergoing mitosis showed that there were more mitotic cells in Ahnak KO mice, consistent with the weight ratio. Our findings suggest that Ahnak enhances TGF-β signaling during postoperative liver regeneration, resulting in cell cycle disruption; this highlights a novel role of Ahnak in liver regeneration. These results provide new insight into liver regeneration and potential treatment targets for liver diseases that require surgical treatment.

Subcutaneous Fibrosarcoma in the Occipital Region with Nuchal Crest Adhesion in a 5-month-old Dog

  • Yoo, Saejong;Kim, Hyo-Joo;Kim, Han-Jun;Lee, So-Yun;Kim, Sung-Ho;Yoo, Young-Sung;Hwang, Jung-Yeon;Do, Sun-Hee;Kim, Hwi-Yool;Kim, Dae-Hyun
    • Journal of Veterinary Clinics
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    • v.35 no.2
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    • pp.63-66
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    • 2018
  • A 5-month-old castrated male Bichon $Fris{\acute{e}}$ was presented with a subcutaneous mass on the occipital region. Anisocytosis, anisokaryosis, and binucleation were observed on the cytology, and the suspected diagnosis was sarcoma. There were no metastatic lesions on radiography or computed tomography. Surgical resection was performed and fibrosarcoma was diagnosed by histopathology and immunohistochemistry. This is a very rare case of a spontaneously occurring subcutaneous fibrosarcoma in a small breed puppy.