The pathogenesis of aplastic anemia (AA) was explored and the effects of AA serum on the expression of crucial cyclin D isoform (cyclin D3) in umbilical cord blood hematopoietic stem/progenitor cells were observed. The CD34+ cells were isolated from the cord blood with MIDI-MACS Semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; The expression level of cyclin D3 was assayed by semi-quantitative RT-PCR and Western-blot after the hematopoietic stem/progenitor cells were incubated in AA serum. The results showed that the AA serum could inhibit the formation of CFU-GM and down regulate the expression level of the cyclin D3 at the mRNA and protein level respectively. In conclusion, the AA serum could inhibit the proliferation of hematopoietic stem cells and down regulate level of cyclin D3, which might be one mechanism of hematopoiesis inhibition in AA.
Anemia, Aplastic/*blood ; Antigens, CD34/*metabolism ; Cells, Cultured ; Colony-Forming Units Assay ; Cyclins/*biosynthesis ; Cyclins/genetics ; Fetal Blood/cytology ; Hematopoietic Stem Cells/*cytology ; Protein Isoforms/biosynthesis ; Protein Isoforms/genetics ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Serum

We analyzed the expression of p21, bcl2, and p53 in normal and different pathologic mucosa of the human colorectum using immunohistochemistry and cold polymerase chain reaction-single strand conformation polymorphism. The topography of normal mucosa showed; bcl2 and p53 expression restricted to basal epithelial cells and p21 expressed only in superficial epithelial cells. This topographic expression was altered in hyperplastic polyps and adenomas. Hyperplastic polyps revealed absence of or weak bcl2 expression and strong p21 expression without topography. In adenomas, whereas bcl2 expression increased and extended to parabasal and superficial dysplastic epithelium, the increase of p21 expression was limited to surface dysplastic epithelium. p53 was weakly expressed throughout the full thickness of dysplastic epithelium. Bcl2 expression in adenomas was stronger than in carcinomas; p53 expression was converse and p21 expression was variable. In carcinomas, this topographic expression was largely abrogated but p53 mutation (36%) was more frequent than in adenomas (2%). In carcinomas, p21 and p53 expression correlated inversely, but there was no relationship with bcl2. These results suggest that there is precisely ordered topographic pattern of p21, bcl2, and wild p53 expression in normal colorectal cells, but this becomes disordered during the early stage of colorectal carcinogenesis.
Colorectal Neoplasms/physiopathology ; Colorectal Neoplasms/pathology ; Colorectal Neoplasms/metabolism* ; Colorectal Neoplasms/genetics ; Cyclins/biosynthesis* ; Human ; Mutagenesis ; Protein p53/genetics ; Protein p53/biosynthesis* ; Proto-Oncogene Proteins c-bcl-2/biosynthesis* ; Time Factors

This paper was designed to investigate the expression of p53, p21 of A549 cell strains under hypoxic condition and the effect of trichostatin A (TSA), the inhibitor of histone deacetylasel (HDAC1) on their expression. The authors designed 1 normoxia group (control group) and 6 hypoxia groups (experimental group): hypoxia 6 h group (A), TSA+hypoxia 6 h (B), hypoxia 12 h group (C), hypoxia 24 h group (D), TSA+hypoxia 24 h (E), hypoxia 48 h group (F). The expression of HDAC1 in A549 cells was examined by using Western blot and the expression of p53, p21 in A549 cells and the effect of TSA on them were determined by using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). The A value expressed by HDAC1 in A549 cell strains was 138+/-11 in the control group, 78+/-4, 86+/-5, 124+/-3, 120+/-9 in experimental groups A, C, D, F, respectively. The A value of the expression of the protein and mRNA of p53 in A549 cell strains were 0.12+/-0.02, 0.62+/-0.02 in the control group, 0.10+/-0.03, 0.32 +/-0.03; 0.11+/-0.01, 0.33+/-0.02; 0.13+/-0.03, 0.58+/-0.01; 0.12+/-0.02, 0.56+/-0.02 in experimental group A, B, D, E, respectively. The A value of the expression of the protein and mRNA of p21 in A549 cell strains were 0.17+/-0.03, 0.62+/-0.03 in the control group, 0.16+/-0.02, 0.50+/-0.02; 0.14+/-0.02, 0.36+/-0.02; 0.15+/-0.03, 0.49+/-0.03; 0.13+/-0.02, 0.33+/-0.02 in experimental groups A, B, D, E, respectively. These results indicate that the expression of HDAC1 is regulated by hypoxia and the effect of TSA is closely related to the expression of P21 under hypoxia condition.
Adenocarcinoma ; metabolism ; pathology ; Cell Hypoxia ; Cyclin-Dependent Kinase Inhibitor p21 ; Cyclins ; biosynthesis ; genetics ; Histone Deacetylase Inhibitors ; Humans ; Hydroxamic Acids ; pharmacology ; Lung Neoplasms ; metabolism ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

The pathogenesis of aplastic anemia (AA) was explored and the effects of AA serum on the expression of crucial cyclin D isoform (cyclin D3) in umbilical cord blood hematopoietic stem/progenitor cells were observed. The CD34+ cells were isolated from the cord blood with MIDI-MACS Semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; The expression level of cyclin D3 was assayed by semi-quantitative RT-PCR and Western-blot after the hematopoietic stem/progenitor cells were incubated in AA serum. The results showed that the AA serum could inhibit the formation of CFU-GM and down regulate the expression level of the cyclin D3 at the mRNA and protein level respectively. In conclusion, the AA serum could inhibit the proliferation of hematopoietic stem cells and down regulate level of cyclin D3, which might be one mechanism of hematopoiesis inhibition in AA.
Anemia, Aplastic ; blood ; Antigens, CD34 ; metabolism ; Cells, Cultured ; Colony-Forming Units Assay ; Cyclin D3 ; Cyclins ; biosynthesis ; genetics ; Female ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans ; Male ; Protein Isoforms ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Serum

OBJECTIVETo investigate the influence of aerosols on the expression of cyclin B(1), cyclin C and proliferating cell nuclear antigen (PCNA) in wound tissue healing of burned rat models.

METHODSSprague Dawley (SD) rats were inflicted as the deep partial thickness burn models. Rats were randomly divided into experimental group and control group. The experimental group were treated with aerosols. Samples were collected in 1 approximately 10 postburn days. Immunohistochemistry and image analysis methods were conducted to examine the expression of cyclin B(1), cyclin C and PCNA in both experimental and control groups.

RESULTSThe expression of cyclin C in experimental group was detected in nucleus of skin basal cell on the second postburn day, increased evidently at the fifth days and sustained at high expression level up to the tenth days after treatment. The expression of cyclin C in experimental group was significantly higher than control group (P < 0.05). The expression of PCNA was first observed in skin basal cell nucleus and hair follicle cell nucleus in both experimental and control group on the third postburn day. The expression of PCNA increased evidently at the fifth days in experimental after treatment and that increased evidently at the seventh days in control group, which showed there were lots of active proliferation cell. And the difference of the expression of PCNA between experimental and control group was significant (P < 0.01). The expression of cyclin B(1) was detected in nucleus and cytoplasm of skin basal cell in both groups on the third postburn day, and no difference between the experimental and control group (P > 0.05).

CONCLUSIONSAerosols can up-regulate the expression of cyclin C and PCNA in skin basal cell nucleus. Therefore the aerosols can accelerate wound tissue healing.

Aerosols ; Animals ; Burns ; metabolism ; therapy ; Cyclin B ; biosynthesis ; Cyclin B1 ; Cyclin C ; Cyclins ; biosynthesis ; Disease Models, Animal ; Electric Stimulation Therapy ; methods ; Female ; Proliferating Cell Nuclear Antigen ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; Wound Healing ; physiology

Intimal hyperplasia is defined as the abnormal migration and proliferation of vascular smooth muscle cells (VSMCs) with deposition of extracellular matrix. However, the cell cycle regulatory mechanisms of injury-induced VSMC proliferation are largely unknown. To examine the expression kinetics of cell cycle regulatory factors which is known to be worked positively or negatively, we used rat balloon injury model. Marked induction of proliferating cell nuclear antigen (PCNA), G1/S cyclin-dependent kinase (cdk2), and its regulatory subunit (cyclin E) occurred between 1 and 3 days after balloon arterial injury, and this was sustained for up to 7 days and then declined. However, the induction of the negative regulators, p21 and p27, occurred between 3 and 5 days of injury, peaked after 7 and 14 days and was then sustained. VSMC proliferation after balloon catheter injury of the rat iliac artery is associated with coordinated expression of positive (cdk2, cyclin E and PCNA) and negative (p21, p27) regulators. Cell cycle regulators such as cdk2, cyclin E, p21, p27 may be suitable targets for the control of intimal hyperplasia.
Animals ; Arteries/*pathology ; Balloon Dilatation/*adverse effects ; Blotting, Western ; CDC2-CDC28 Kinases/biosynthesis ; Cell Cycle ; Cell Cycle Proteins/biosynthesis ; Cell Division ; Cyclin E/biosynthesis ; Cyclins/biosynthesis ; Endothelium, Vascular/pathology ; Extracellular Matrix/metabolism ; Hyperplasia/pathology ; Iliac Artery/pathology ; Immunohistochemistry ; Male ; Myocytes, Smooth Muscle/*cytology ; Proliferating Cell Nuclear Antigen/biosynthesis ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't ; Time Factors ; Tumor Suppressor Proteins/biosynthesis

OBJECTIVETo study the growth inhibitory effects of p21WAF1 and p53 overexpression in human lung adenocarcinoma cell line.

METHODSThe p21WAF1 and p53 gene were transfected respectively into a human lung adenocarcinoma cell line, GLC-82. Flow cytometry (FLC), transmission electron microscopy (EM) and TUNEL technique were used to evaluate cell growth and identify apoptosis.

RESULTSThe GLC-82 transfected by p21 plasmid showed increased cell number in G1 phase of cell cycle, decreased proliferation potential and decreased cloning efficiency. Apoptosis have not been detected neither on EM nor by TUNEL technique, whereas the GLC-82 infected by Ad-p53 showed significantly decreased proliferation potential and some of them even died, in addition apoptosis was confirmed by TUNEL technique.

CONCLUSIONThe results indicate that p21WAF1 and p53 can inhibit proliferation; p53 also can induce apoptosis of lung adenocarcinoma cell. Therefore, these two genes should have a wide application in gene therapy of tumors in future.

Adenocarcinoma ; genetics ; metabolism ; pathology ; Apoptosis ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; Cyclins ; biosynthesis ; genetics ; Gene Expression ; Humans ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVETo focus on the study of the effect on proliferation and apoptosis of human aortic smooth muscle cells (ASMC) by adeno-associated virus (AAV) vector carrying antisense thrombin receptor (ATR) and p21 double gene co-expression system.

METHODSCultured human AMSC was infected with recombinant AAV containing ATR, p21 single gene and AP double gene respectively. The integration and expression of genes were confirmed by semi-quantitative RT-PCR. The anti-proliferation effect was determined by MTT assay. Cell cycle and apoptotic cell counts were measured through Flow Cytometry. The rate of apoptotic cells was examined with acridine orange/ethidium bromide(AO/EB) stain.

RESULTSRT-PCR indicated that the exogenous genes had been integrated into ASMC. The rates of cell survival were decreased by 16.67%, 21.60%, and 29.4% and the cell counts of G0/G1 phase were (61.8 +/- 2.9)%, (82.5 +/- 4.0)%, (80.4 +/- 6.1)% in ATR, p21 and AP group respectively after rAAV infected 4 days. The level and area of apoptotic peak were greater in AP double gene than ATR and p21 single gene. Cell stain indicated that apoptotic cells were (7.2 +/- 3.3)%, (10.7 +/- 5.6)%, and (18.3 +/- 2.7)% in each transgene group compared with (1.5 +/- 0.8)% in control group.

CONCLUSIONAP double gene co-expression system has powerful effect for inhibiting proliferation and inducing apoptosis ASMC than ATR and p21 single gene and that is a superior way for gene therapy to restenosis.

Adenoviruses, Human ; genetics ; Antisense Elements (Genetics) ; Aorta ; cytology ; Apoptosis ; Cell Division ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p21 ; Cyclins ; biosynthesis ; genetics ; Fetus ; Genetic Vectors ; Humans ; Muscle, Smooth, Vascular ; cytology ; Receptors, Thrombin ; biosynthesis ; genetics

OBJECTIVETo detect the expression of cell cycle positive regulators cyclin D(1), cyclin E, CDK(2), CDK(4) and negative regulators p21(cip1), p27(kip1), p16(ink4a) and p15(ink4b) during wound healing in rats.

METHODSOpen wounds of full-thickness skin, diameter 1.8 cm, on rat backs were used as the wound model. Wound tissues were harvested on postwounding days 3, 5, 7, 9, 11, 14, 21 and 30. Ki67 expression in granulation tissue was detected by immunohistochemical assay. The patterns of the expression of cyclin D(1), cyclin E, CDK(2), CDK(4) and p21(cip1), p27(kip1), p16(ink4a), p15(ink4b) were detected by Western blot.

RESULTSCell proliferation in granulation tissue took place predominantly within the first week after injury, with the proliferation peak occurring at postwounding day 5. There were no dramatic variations in the expression of cyclin D(1), CDK(2) and CDK(4) during wound healing. Up-regulated cyclin E was maintained from day 3 to 11 after injury, and then was down-regulated. No expression of p16(ink4a) and p15(ink4b) was found. p21(cip1) was expressed only from day 7 to 14, with peak expression observed on day 9. Constitutive p27(kip1) was expressed throughout wound healing with low levels in the proliferating period of day 3 to 5 and with increased levels in the post-mitotic and remodeling stage. The expression of p21(cip1) and p27(kip1) showed an inverse gradient to that of Ki67.

CONCLUSIONp21(cip1) and p27(kip1) play a supervising role in preventing the hyperproliferative tendency in tissue repair.

Animals ; Cell Cycle ; physiology ; Cell Cycle Proteins ; biosynthesis ; physiology ; Cell Division ; physiology ; Cyclin-Dependent Kinase Inhibitor p16 ; biosynthesis ; Cyclin-Dependent Kinase Inhibitor p27 ; Cyclin-Dependent Kinases ; antagonists & inhibitors ; biosynthesis ; Cyclins ; biosynthesis ; Male ; Rats ; Rats, Wistar ; Skin ; cytology ; metabolism ; Tumor Suppressor Proteins ; biosynthesis ; physiology ; Wound Healing

Epidemiological studies have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs) decrease the incidence of colon cancer. In addition, NSAIDs reduce the number and size of polyps in patients with familial adenomatous polyposis. The mechanisms of the anti-neoplastic effect of NSAIDs are still far from complete understanding, but one possible mechanism is the induction of apoptosis. Several lines of evidence suggest that NSAIDs-induced apoptosis in colon cancer cells are mediated through the cyclooxygenase (COX)-independent pathway. In this study we explored the mechanism of NSAIDs-induced apoptosis in the colon cancer cell line, HT-29. We confirmed that NSAIDs induce apoptosis in HT-29 cells irrespective of their COX-selectivity. Indomethacin enhanced the expression of p21waf-1 in HT-29 cells. However the expression of apoptosis-related genes such as Fas, bcl-2 and bax was not affected by indomethacin. Intra- and extra-cellular calcium chelators, protein tyrosine kinase (PTK) inhibitor, protein kinase A (PKA) inhibitor and protein kinase C (PKC) inhibitors did not influence indomethacin-induced apoptosis in HT-29 cells. We concluded that NSAIDs-induced apoptosis in colon cancer cells may be independent from signals transducted through [Ca++]i, PTK, PKA, PKC or the expression of apoptosis-related genes. In contrast, our results demonstrating the induction of p21waf-1 transcription by NSAIDs suggest the possible association of NSAIDs-induced apoptosis and cell-cycle control in colon cancer cells.
Anti-Inflammatory Agents, Non-Steroidal/pharmacology* ; Apoptosis/drug effects* ; Calcium/metabolism ; Cell Survival/drug effects ; Colonic Neoplasms/prevention & control* ; Colonic Neoplasms/pathology ; Cyclins/genetics ; Cyclins/biosynthesis ; HT29 Cells ; Human ; Protein Kinases/physiology ; Protein p53/physiology ; Proto-Oncogene Proteins c-bcl-2/analysis ; RNA, Messenger/analysis