OBJECTIVETo investigate the effects of AMPK agonist Acadesine (AICAR) on growth inhibition of K562 cells and their sensitivity to imatinib (IM).

METHODSK562 cells were cultured with different concentrations of AICAR alone or its combination with IM for 48 hours, the CCK-8 assay was used to detect cell proliferation, the cell cycle distribution and apoptosis were analyzed by flow cytometry. The expression levels of Cyclin D1, Cyclin E1 and Caspase 3 protein were determined by Western blot.

RESULTSAICAR inhibited the proliferation of K562 cells in dose-dependent manner, and their IC50 value was 0.45 mmol/L at 48 hours. AICAR could induce arrest of K562 cells in G1 phase and down-regulated the protein expression levels of Cyclin D1 and Cyclin E1; whereas it didn't influence the cell apoptosis. Additionally, the growth inhibition of cells induced by IM was enhanced by AICAR.

CONCLUSIONAICAR can inhibit the proliferation of K562 cells by arresting the cell cycle and enhancing the sensitivity of K562 cells to IM.

Aminoimidazole Carboxamide ; analogs & derivatives ; pharmacology ; Apoptosis ; Caspase 3 ; metabolism ; Cell Cycle Checkpoints ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Humans ; Imatinib Mesylate ; pharmacology ; K562 Cells ; drug effects ; Oncogene Proteins ; metabolism ; Ribonucleosides ; pharmacology

An F-box protein, beta-TrCP recognizes substrate proteins and destabilizes them through ubiquitin-dependent proteolysis. It regulates the stability of diverse proteins and functions as either a tumor suppressor or an oncogene. Although the regulation by beta-TrCP has been widely studied, the regulation of beta-TrCP itself is not well understood yet. In this study, we found that the level of beta-TrCP1 is downregulated by various protein kinase inhibitors in triple-negative breast cancer (TNBC) cells. A PI3K/mTOR inhibitor PI-103 reduced the level of beta-TrCP1 in a wide range of TNBC cells in a proteasome-dependent manner. Concomitantly, the levels of c-Myc and cyclin E were also downregulated by PI-103. PI-103 reduced the phosphorylation of beta-TrCP1 prior to its degradation. In addition, knockdown of beta-TrCP1 inhibited the proliferation of TNBC cells. We further identified that pharmacological inhibition of mTORC2 was sufficient to reduce the beta-TrCP1 and c-Myc levels. These results suggest that mTORC2 regulates the stability of beta-TrCP1 in TNBC cells and targeting beta-TrCP1 is a potential approach to treat human TNBC.
Cell Line, Tumor ; Cell Proliferation ; Cell Survival/drug effects ; Cyclin E/genetics/metabolism ; Dose-Response Relationship, Drug ; Female ; Furans/pharmacology ; Gene Knockdown Techniques ; Humans ; Models, Biological ; Multiprotein Complexes/antagonists & inhibitors ; Phosphatidylinositol 3-Kinases/*antagonists & inhibitors ; Phosphorylation/drug effects ; Protein Kinase Inhibitors/*pharmacology ; Proteolysis/drug effects ; Proto-Oncogene Proteins c-myc/genetics/metabolism ; Pyridines/pharmacology ; Pyrimidines/pharmacology ; TOR Serine-Threonine Kinases/*antagonists & inhibitors ; Triple Negative Breast Neoplasms/genetics/*metabolism ; beta-Transducin Repeat-Containing Proteins/genetics/*metabolism

Bmi1 is a member of the polycomb group family of proteins, and it drives the carcinogenesis of various cancers and governs the self-renewal of multiple types of stem cells. However, its role in the initiation and progression of bladder cancer is not clearly known. The present study aimed to investigate the function of Bmi1 in the development of bladder cancer. Bmi1 expression was detected in human bladder cancer tissues and their adjacent normal tissues (n=10) by immunohistochemistry, qRT-PCR and Western blotting, respectively. Bmi1 small interference RNA (siRNA) was synthesized and transfected into human bladder carcinoma cells (EJ) by lipofectamine 2000. The Bmil expression at mRNA and protein levels was measured in EJ cells transfected with Bmil siRNA (0, 80, 160 nmol/L) by qRT-PCR and Western blotting, respectively. Cell viability and Ki67 expression (a marker of cell proliferation) were determined in Bmi1 siRNA-transfected cells by CCK-8 assay and qRT-PCR, respectively. Cell cycle of transfected cells was flow-cytometrically determined. Immunofluorescence and Western blotting were used to detect the expression levels of cell cycle-associated proteins cyclin D1 and cyclin E in the cells. Pro-apoptotic proteins Bax and caspase 3 and anti-apoptotic protein Bcl-2 were detected by Western blotting as well. Additionally, xenograft tumor models were established by inoculation of EJ cells (infected with Bmil shRNA/pLKO.1 lentivirus or not) into nude mice. The tumor volumes were measured every other day for 14 days. The results showed that the Bmil expression was significantly increased in bladder tumor tissues when compared with that in normal tissues (P<0.05). Perturbation of Bmi1 expression by using siRNA could significantly inhibit the proliferation of EJ cells (P<0.05). Bmi1 siRNA-transfected EJ cells were accumulated in G1 phase and the expression levels of cyclin D1 and cyclin E were down-regulated. Bax and caspase-3 expression levels were significantly increased and Bcl-2 levels decreased after Bmi1 knockdown. Tumor volume was conspicuously reduced in mice injected with EJ cells with Bmi1 knockdown. Our findings indicate that Bmi1 is a potential driver oncogene of bladder cancer and it may become a potential treatment target for human bladder cancer.
Animals ; Apoptosis ; genetics ; Carcinogenesis ; genetics ; metabolism ; pathology ; Carcinoma ; genetics ; metabolism ; pathology ; therapy ; Caspase 3 ; genetics ; metabolism ; Cell Line, Tumor ; Cyclin D1 ; antagonists & inhibitors ; genetics ; metabolism ; Cyclin E ; antagonists & inhibitors ; genetics ; metabolism ; G1 Phase Cell Cycle Checkpoints ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Injections, Intralesional ; Ki-67 Antigen ; genetics ; metabolism ; Mice ; Mice, Nude ; Polycomb Repressive Complex 1 ; antagonists & inhibitors ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; genetics ; metabolism ; RNA, Small Interfering ; administration & dosage ; genetics ; metabolism ; Signal Transduction ; Tumor Burden ; Urinary Bladder ; metabolism ; pathology ; Urinary Bladder Neoplasms ; genetics ; metabolism ; pathology ; therapy ; Xenograft Model Antitumor Assays ; bcl-2-Associated X Protein ; agonists ; genetics ; metabolism

This study aimed to evaluate the effects of Pin1 inhibitor Juglone on proliferation, migration and the angiogenic ability of breast cancer cell line MCF7Adr. MCF7Adr cells were cultured and separately treated with Pin1 inhibitor Juglone (treatment group) and DMEM without drug (control group). The cell cycle was examined by flow cytometry. Cell migration was measured by wound-healing assay. Cyclin E protein content was detected by Western blotting. The angiogenesis factor vascular endothelial growth factor (VEGF) in cell media was determined by enzyme linked immunosorbent assay. The results showed that the percentage of cells in G2/M phase in treatment group was significantly higher than that in control group (25.5% vs. 10.1%, P<0.05), and that in G0/G1 phase and S stage in treatment group was significantly lower than that in control group (40.5% vs. 48.2%, and 33.7% vs. 41.7%, P<0.05). Cyclin E protein content in treatment group was significantly lower than that in control group (39.2 ± 7.4 vs. 100 ± 23.1, P<0.05). (A0-A24)/A0 value in treatment group was significantly lower than that in control group (23.9 ± 3.8 vs. 100 ± 14.4, P<0.05). VEGF-A, -B, and -C contents in cell media of treatment group were significantly lower than those in control group (P<0.05). It was suggested that Pin1 inhibitor Juglone can effectively inhibit the proliferation, migration and the angiogenic ability of MCF7Adr cells, and can be used as an alternative drug therapy for breast cancer.
Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; drug therapy ; metabolism ; Cell Cycle ; drug effects ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cyclin E ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; MCF-7 Cells ; NIMA-Interacting Peptidylprolyl Isomerase ; Naphthoquinones ; pharmacology ; Peptidylprolyl Isomerase ; antagonists & inhibitors ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo investigate the effect of emodin on proliferation and cell cycle distribution of human oral squamous carcinoma cells in vitro.

METHODSCultured human oral squamous carcinoma Tca8113 cells were treated with 2.5, 5, 10, 20, 40, 60 and 80 µmol/L emodin for 24, 48 or 72 h, with the cells treated with 0.1% DMSO as control. MTT assay and flow cytometry were used to evaluate the changes in cell proliferation and cell cycle distribution, respectively. Western blotting was employed to analyze the changes in the expression levels of the cell cycle-related proteins CDK2, cyclin E and P21 after emodin treatment.

RESULTSEmodin significantly inhibited the growth and proliferation of Tca8113 cells within 72 h in a time- and dose-dependent manner, and caused cell cycle arrest in G0-G1 phase. Western blotting revealed that emodin treatment significantly lowered the expression levels of CDK2, cyclin E and P21 proteins in Tca8113 cells (P<0.05).

CONCLUSIONEmodin can inhibit the proliferation of Tca8113 cells and affect their cell cycle distribution possibly by inhibiting the signaling pathways of cell cycle regulation.

Carcinoma, Squamous Cell ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; drug effects ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Emodin ; pharmacology ; Humans ; Mouth Neoplasms ; pathology ; Oncogene Proteins ; metabolism ; Signal Transduction

This study was aimed to investigate the effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of human acute myeloid leukemia cell line HL-60 and its mechanism. HL-60 cells were cultured with different concentrations of celecoxib for 24 h. Cell proliferation was analyzed by CCK-8 assay, cell apoptosis and cell cycle distribution were detected by flow cytometry. Cyclin D1, cyclin E1 and COX-2 mRNA expressions were determined by RT-PCR. The results showed that after the HL-60 cells were treated with different concentrations of celecoxib for 24 h, the cell growth was significantly inhibited in a dose-dependent manner(r = 0.955), IC50 was 63.037 µmol/L of celecoxib. Celecoxib could effectively induce apoptosis in HL-60 cells also in dose-dependent manner(r = 0.988), blocked the HL-60 cells in the G0/G1 phase. The expression of cyclin D1, cyclin E1 and COX-2 mRNA were downregulated. It is concluded that celecoxib can inhibit the proliferation of HL-60 cells in dose-dependent manner, celecoxib causes cell G0/G1 arrest and induces cell apoptosis possibly through down-regulation of the cyclin D1 and cyclin E1 expression, and down-regulation of COX-2 expression respectively.
Apoptosis ; drug effects ; Celecoxib ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Gene Expression Regulation, Leukemic ; HL-60 Cells ; Humans ; Oncogene Proteins ; metabolism ; Pyrazoles ; pharmacology ; Sulfonamides ; pharmacology

OBJECTIVE: To investigate the expression and clinicopathological significance of the cell cycle regulators cyclin E, cyclin D1, p21, p16 in laryngeal carcinogenesis tissus. METHOD: The expression of cell cycle regulators were detected by flow cytometry method in 23 cases of polyps of vocal cord, 69 cases of laryngeal precancerous change and 33 cases of laryngeal squamous cell carcinoma (LSCC), which tissue was paraffin embedded, sliced, dewaxed, and prepared into the cell suspension, then fluorescently labeled by cyclin E, cyclin D1, p21 and p16. RESULT: In polyps of vocal cord, laryngeal precancerous change and LSCC, The positive expression rate of cyclin E and cyclin D1 were respectively 13.04%, 20.29D, 42.420 and 26.09%, 43.48% and 93.94%. The positive expression rate of p16 and p21 were respectively 61.90%, 40.98%, 14.28% and 47.62%, 23.81%, 26.23%. Those showed the positive expression rate of cyclin D1, cyclin E gradually decreased from vocal cord polyps, laryngeal precancerous change to LSCC, (P < 0.05, P < 0.01), while the positive expression rate of p21 and p16 gradually decreased (P < 0.01). CONCLUSION The abnormal expression of cell cycle regulatory factors is the molecular events of laryngeal carcinoma. High expression of positive regulatory factors cyclin D1 and cyclin E, and low expression of negative regulatory factors p16 and p21, which showed the imbalance of multiple positive and negative regulatory factors related with cell cycle play an important role in the occurrence of laryngeal cancer.
Adult ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Female ; Flow Cytometry ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; Oncogene Proteins ; metabolism

OBJECTIVE: To explore new hallmarks affecting the prognosis of patients with laryngeal squamous cell carcinoma (LSCC) via investigating the expression of CyclinE and p27 in LSCC tissues. METHOD: The expression of CyclinE and p27 was detected via Elivision immunohistochemical staining in 160 LSCC tissues and 20 normal laryngeal tissues (NLT). The relationship between CyclinE/ p27 and LSCC/ NLT was analyzed via Log-rank analysis. The relationship of CyclinE and p27 protein was statistically analyzed by spearman correlation analysis. The relationship between CyclinE/p27 and clinical-pathology-factors of patients with LSCC, such as age, gender, tumor site, diameter, differentiation, lymph node metastasis and PTNM stage were analyzed by Chi-square test. The relationship between clinical-pathology-factors, CyclinE, p27 and overall survival time of patients with LSCC was analyzed via Cox multiplicity and Kaplan-Meier survival analysis. A significant difference was recognized by P<0.05. RESULT: In LSCC the positive rates of CyclinE and p27 protein was 62.50% and 41.25% respectively (P<0.05). In NLT the positive rates of CyclinE and p27 protein was 35% and 70% respectively (P<0.05). The expression of CyclinE or p27 protein was closely correlated with lymph node metastasis, PTNM stage of patients with LSCC (P<0.05). The expression of CyclinE and p27 had no significant correlations with patients' gender, age and tumor site, diameter differentiation (P>0.05 for all). A negative correlation was found between the expression of CyclinE and p27 protein, r= -0.767(P<0.05). Kaplan-Meier survival analysis showed that the overall survival rate of patients with LSCC was 36.9% (P<0.05). The 5-year survival rate in positive group of CyclinE was 8%, in negative group was 80% (P<0.05). On the contrary, the 5-year survival rate of patients with LSCC in positive group of p27 protein was 77.27%, the rate was 5.32% in negative group (P<0.05). Cox multivariate regression analysis revealed that lymph node metastasis, PTNM stage, CyclinE and p27 were independent risk factors of prognosis for patients with LSCC. CONCLUSION It is the molecular basis underlying the development and invasion/ metastasis of LSCC that activation of CyclinE gene accompanying inactivation of p27 gene. It is very important of co-detecting CyclinE and p27 protein to predict the prognosis of patients with LSCC.
Carcinoma, Squamous Cell ; metabolism ; pathology ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Female ; Head and Neck Neoplasms ; metabolism ; pathology ; Humans ; Laryngeal Mucosa ; metabolism ; pathology ; Laryngeal Neoplasms ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Oncogene Proteins ; metabolism ; Prognosis ; Squamous Cell Carcinoma of Head and Neck ; Survival Rate

OBJECTIVETo analyze the centrosome abnormalities in the malignant transformation of human bronchial epithelial cells (BEAS-2B) induced by coal tar pitch smoke extracts and to investigate the role and action mechanism of centrosome in the lung cancer induced by coal tar pitch.

METHODSMedium-temperature coal tar pitch smoke extracts were used to treat immortalized human bronchial epithelial cells (BEAS-2B) and establish a malignant transformation model. The treated BEAS-2B cells were used as exposure group, and solvent control group and normal control group were also set for passage culture. The changes of centrosome in BEAS-2B cells seeded on coverslips were evaluated by indirect immunofluorescence assay. The mRNA expression of p53, p21, and cyclin E in BEAS-2B cells was measured by real-time quantitative RT-PCR, and their protein levels in BEAS-2B cells seeded on coverslips were measured by semiquantitative immunohistochemical analysis.

RESULTSThe overall rate of centrosome abnormalities in BEAS-2B cells at passage 20 was 6.56±1.01% in the exposure group, significantly higher than those in the normal control group (3.40±0.86%) and solvent control group (3.14±0.59%) (P < 0.05). In addition, the exposure group had a significantly higher overall rate of centrosome abnormalities in BEAS-2B cells at passage 30 compared with the normal control group and solvent control group (22.39±9.5% vs 4.34±1.04%, P < 0.05; 22.39±9.5% vs 4.33±1.20%, P < 0.05). Compared with the normal control group and solvent control group, the exposure group had significantly decreased mRNA and protein expression of p53 and significantly increased mRNA and protein expression of cyclin E in BEAS-2B cells at passages 20 and 30 (P < 0.05).

CONCLUSIONCentrosome abnormalities occur before the malignant transformation in BEAS-2B cells treated with coal tar pitch smoke extracts, and they may be mediated by the p53/p21/cyclin E signaling pathway.

Cell Line ; Cell Transformation, Neoplastic ; metabolism ; pathology ; Centrosome ; metabolism ; pathology ; Coal Tar ; Cyclin E ; metabolism ; Epithelial Cells ; cytology ; metabolism ; Humans ; Signal Transduction ; Smoke ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo characterize the human primary cyclins (D1, E, A, B1) expressed in gastric carcinoma, and to clarify the relationship between the types of expressed primary cyclins and clinicopathological features of gastric carcinoma.

METHODSPrimary cyclins (D1, E, A, B1) expressed in single cells separated from 68 cases gastric carcinoma tissues were analyzed by flow cytometry. We classified the gastric carcinomas by different types of the expressed primary cyclins, and explore the roles of primary cyclins expressed in cell cycle and the expression patterns of the cyclins. The results were analyzed together with clinicopathological features.

RESULTSThe patterns of expressed primary cyclins could be classified into five types. The proportion was 10.3% (7/68), 22.1% (15/68), 25.0% (17/68), 29.4% (20/68), and 13.2% (9/68), respectively, from type I to type V. Each type could be, according to the degree of in-cycle cyclins expressed, divided into different sub-types. The types of primary cyclins expressed were strongly linked to invasive depth and lymph node metastasis of the gastric carcinoma (P < 0.01). The rates of lymph node metastasis were 26.6%, 43.8%, 82.3%, 95.0%, and 100.0%, respectively, from type I to type V. The type of primary cyclins expressed was also significantly associated with disease stage (TNM stage). The proportion of stage IV disease was 0, 6.7%, 17.6%, 25.0% and 55.6%, respectively, from type I to type V. It was shown that there were relationships between the sub-types of primary cyclins expressed and different growth-types, degree of cell differentiation, or, the tumor gross types (P < 0.01).

CONCLUSIONSThe types of primary cyclins expression are different in the process of the occurrence, development and metastasis of gastric carcinoma, and are correlated with clinicopathological features of gastric carcinoma.

Adult ; Aged ; Aged, 80 and over ; Cell Differentiation ; Cyclin A1 ; metabolism ; Cyclin B1 ; metabolism ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Cyclins ; classification ; metabolism ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Staging ; Oncogene Proteins ; metabolism ; Stomach Neoplasms ; metabolism ; pathology