The advance of experimental cell division and proliferation in the field of cell biomechanics is presented in this paper. The emphasis is placed on the research in the mechanics mechanism of cleavage furrow and in the measurement of constricting force about cleavage furrow.
Biomechanical Phenomena ; Cell Division ; physiology ; Cytokinesis ; physiology ; Humans

OBJECTIVETo investigate the biological characteristics of cell lines of healthy and diseased human dental alveoli.

METHODSPrimary cell lines from either healthy or diseased human dental alveoli were obtained. Two cell lines, H-258 and H-171 derived from healthy and diseased human tissues respectively, were selected for morphological study and research on their growth and aging, using cell counting, and histochemical and immunohistochemical staining.

RESULTSPrimary cell lines were successfully established from innormal dental alveoli. After freezing and thawing for three times, cell growth was continued and no morphological alterations were observed. The doubling time was 53.4 hours and mean division index (MDI) was 4 per thousand. Cells were kept normal after twenty generations with no obvious reduction of doubling time and MDI. Of twenty-six primary cell lines derived from healthy human dental alveoli, only three cell lines achieved generation. After freezing and thawing for twice, cultured cells were still alive at a decreased growth speed, with doubling time of 85.9 hours and MDI of 3 per thousand. Both cell lines, H-171 and H-258, shared the characteristics of osteoblast.

CONCLUSIONSPrimary cell lines of diseased human dental alveoli show greater growth potential. All cell lines of dental alveoli share characteristics of osteoblast. The technique we developed may be put into practice for the treatment of abnormal dental alveoli.

Cell Division ; physiology ; Cell Line ; Humans ; Tooth Socket ; cytology

OBJECTIVETo observe the immune reaction in the mixed culture of host lymphocytes with allogenic and host endothelial cells.

METHODSThe host epithelial cells and lymphocytes from burn patients and allogenic epithelial cells were mix-cultured in different ratios, so as to simulate the local immune micro-environment of host skin island in intermingled skin grafting. In addition, the cells from normal human subjects were also mix-cultured as control. The lymphocyte cpm values were detected by (3)H-TdR and HLA molecules and T cell subgroup were determined by immunohistological technique.

RESULTS(1) The lymphocyte proliferation reaction could be effectively inhibited by the epithelial cells from burn patients but not from normal control. (2) The inhibition of host lymphocyte proliferation could not be mediated by the HLA-DQ molecules of epithelium from burn patients. (3) The positive expression rate of HLA-DR of epithelia from burn patients was evidently higher that that from normal control (P < 0.05), (4) The CD8 expression of lymphocyte in burn patients was significantly higher than that in normal control (P < 0.01), while the CD4 expression in burn patients was lower than that in normal control (P < 0.01). But there was no obvious difference of the CD3 expression between patients and normal subjects (P > 0.05).

CONCLUSIONThe lymphocyte proliferation reaction could be obviously inhibited by the host epithelium, which might be related to the specific immune state of the host lymphocytes and epithelium of burn patients.

Cell Communication ; immunology ; physiology ; Cell Culture Techniques ; Cell Division ; Epithelial Cells ; immunology ; physiology ; Humans ; Lymphocytes ; immunology ; physiology ; Skin Transplantation ; immunology

The tumor suppressor gene p53 and p16, both of which play an important role in inhibition of tumorigenesis, are homozygously deleted in human myeloid leukemia cell line K562. To explore the inhibition of K562 cell proliferation by wild type p16 and p53 genes, both p16 and p53 genes were co-transfected into K562 cells mediated by liposome. The expression of the two genes was measured by immunocytochemical method, the cell cycle was analysed by flow cytometry, and the number of recovered viable cells was assessed after transfection. After co-transfection, the p53 and p16 positive cells were 23% and 28%, respectively. The results showed that co-transfection of p16 and p53 genes significantly inhibits cell proliferation comparing with transfection either by p16 gene or by p53 gene (P < 0.05). Expression of p16 and p53 proteins increased the cell number in G(1) phase but decreased the cell number in S phase. It is concluded that co-transfection of p16 and p53 genes has a stronger growth-inhibitory effect on K562 cell growth than that of transfection only by p16 gene or by p53 gene, may be a pathway for gene therapy in leukemia.
Cell Division ; Genes, p16 ; physiology ; Genes, p53 ; physiology ; Humans ; K562 Cells ; Plasmids ; Transfection

Repairing DNA double-strand breaks (DSBs) with homologous chromosomes as templates is the hallmark of meiosis. The critical outcome of meiotic homologous recombination is crossovers, which ensure faithful chromosome segregation and promote genetic diversity of progenies. Crossover patterns are tightly controlled and exhibit three characteristics: obligatory crossover, crossover interference, and crossover homeostasis. Aberrant crossover patterns are the leading cause of infertility, miscarriage, and congenital disease. Crossover recombination occurs in the context of meiotic chromosomes, and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally. Meiotic chromosomes are organized in a loop-axis architecture. Diverse evidence shows that chromosome axis length determines crossover frequency. Interestingly, short chromosomes show different crossover patterns compared to long chromosomes. A high frequency of human embryos are aneuploid, primarily derived from female meiosis errors. Dramatically increased aneuploidy in older women is the well-known "maternal age effect." However, a high frequency of aneuploidy also occurs in young women, derived from crossover maturation inefficiency in human females. In addition, frequency of human aneuploidy also shows other age-dependent alterations. Here, current advances in the understanding of these issues are reviewed, regulation of crossover patterns by meiotic chromosomes are discussed, and issues that remain to be investigated are suggested.
Cell Division/physiology* ; Chromosome Segregation/physiology* ; Humans ; Meiosis/genetics* ; Recombination, Genetic

Rho-associated coiled-coil protein kinase (ROCK) is a serine/threonine kinase that belongs to AGC family of kinases. By inducing the formation of stress fibers and reorganizing the cytoskeleton, it is involved in many biological behaviors of cells including cell contraction, cell migration, cell division, and morphological changes, and thus exerts important roles in regulating the multiple functions of cells.
Cell Division ; Cell Movement ; Cytoskeleton ; metabolism ; Humans ; rho-Associated Kinases ; metabolism ; physiology

This study was done for investigating the frequency and proliferative feature of mesenchymal stem/progenitor cells (MSPC) in human umbilical cord blood (CB) and for searching a new seed cell for tissue engineering. Mononuclear cells was separated by Ficoll-Hypaque from cord blood and suspended in DMEM culture medium supplemented by 2% fetal bovine serum. The adherent CB cells were cultured and expanded at same medium. The results showed that the frequency of CB-MSPC was 0.5 x 10(-6) [(0.2 - 0.8) x 10(-6)]. The CB-MSPC showed a fibroblast-like morphology and retained their morphological feature at least after 20 sub-passages, and could extensively be expanded by about 1.3 x 10(7) times as much. The conclusion is that low serum DMEM culture could maintain the proliferation and differentiation potential of CB-MSPC. CB-MSPC might be a favorable seed cell for tissue engineering and regeneration.
Cell Adhesion ; Cell Division ; Fetal Blood ; cytology ; Humans ; Mesenchymal Stromal Cells ; physiology ; Tissue Engineering

The cell cycle is a complex process that involves DNA replication, protein expression, and cell division. Dysregulation of the cell cycle is associated with various diseases. Cyclin-dependent kinases (CDKs) and their corresponding cyclins are major proteins that regulate the cell cycle. In contrast to inhibition, a new approach called proteolysis-targeting chimeras (PROTACs) and molecular glues can eliminate both enzymatic and scaffold functions of CDKs and cyclins, achieving targeted degradation. The field of PROTACs and molecular glues has developed rapidly in recent years. In this article, we aim to summarize the latest developments of CDKs and cyclin protein degraders. The selectivity, application, validation and the current state of each CDK degrader will be overviewed. Additionally, possible methods are discussed for the development of degraders for CDK members that still lack them. Overall, this article provides a comprehensive summary of the latest advancements in CDK and cyclin protein degraders, which will be helpful for researchers working on this topic.
Humans ; Cell Cycle/physiology* ; Cell Division ; Cyclin-Dependent Kinases/metabolism* ; Cyclins/metabolism*

OBJECTIVETo establish a strain of human cervical carcinoma cell line and to provide a cervical carcinoma animal model.

METHODSThe cervical carcinoma specimens incised aseptically were cultured in vitro by tissue culture methods, giving a tumor cell growth curve. Morphology of the cells was observed, with cell cycling analysis and chromosome analysis performed. The tumor markers (ER, PR, Keratine, PCNA) expressions of the cell line were detected by immuno-cytochemical technique.

RESULTSA human cervical carcinoma cell line HCC-0214 (H) has been obtained by in vitro tissue culture methods. The cells have been maintained for 16 months through 131 passages, showing a stable growth with a population doubling time of 35.48 h and a tendency to pile up without contact inhibition. The ultrastructure showed typical desmosomes and numerous tonofilaments. Chromosome analysis revealed the number of chromosomes per cell varied from 35-156 with a stem-line number of 58-80 (64.8%). The morphology of chromosomes showed human tumor cell structure. The tumor markers (ER, PR, Keratine, PCNA) of the cells showed a high expression. The DNA index was 1.931 by flow cytometry (FCM). The histopathology of the transplanted tumors in nude mice was the same as the original tumor, though with none successful by serum culture.

CONCLUSIONA human cervical carcinoma cell line HCC-0214 established by tissue culture is identical to the primary cancer cell in biological characters. After the cells have been passaged for more than 16 months continually, their characteristics are still retained. Therefore, HCC-0214 may be used as a stable cell line.

Cell Culture Techniques ; methods ; Cell Division ; physiology ; Female ; Humans ; Tumor Cells, Cultured ; physiology ; Uterine Cervical Neoplasms ; pathology

The proliferation and apoptosis of multiple myeloma (MM) cells were regulated by bone marrow microenvironments in which Notch signal plays important role in mediating cell-cell communication. However, the regulatory effect of Notch signal on the proliferation and apoptosis of multiple myeloma cells remains unclear. In this study, regulatory effect of Notch signal on the apoptosis of MM cells induced by DMS (N, N-dimethylsphingosine) was investigated. RT-PCR was used to identify the expression of Notch receptor and related molecules such as Dll-1, Jagged-1, Deltex-1 in MM cell lines. The intracellular domain of Notch (ICN), active form of Notch, was transferred into MM cells by retrovirus. The apoptosis of MM cells was determined by trypan blue exclusion tests and TdT-mediated dUTP nick end labeling (TUNEL) assay. The results showed that multiple myeloma cells expressed the Notch-1 and its related molecules. Notch activated multiple myeloma cell lines were obtained. Activation of Notch protected the multiple myeloma cells from the apoptosis induced by DMS,which was determined by cell viability and TUNEL assay. In conclusion, Notch signal suppressed the apoptosis of multiple myeloma cells and would possibly be a novel therapeutic target.
Apoptosis ; Cell Division ; Humans ; Multiple Myeloma ; drug therapy ; pathology ; Receptor, Notch1 ; Receptors, Cell Surface ; physiology ; Signal Transduction ; Transcription Factors ; physiology