BackgroundMicroRNA-24 (miR-24) plays an important role in heart failure by reducing the efficiency of myocardial excitation-contraction coupling. Prolonged cardiac hypertrophy may lead to heart failure, but little is known about the role of miR-24 in cardiac hypertrophy. This study aimed to preliminarily investigate the function of miR-24 and its mechanisms in cardiac hypertrophy.

MethodsTwelve Sprague-Dawley rats with a body weight of 50 ± 5 g were recruited and randomly divided into two groups: a transverse aortic constriction (TAC) group and a sham surgery group. Hypertrophy index was measured and calculated by echocardiography and hematoxylin and eosin staining. TargetScans algorithm-based prediction was used to search for the targets of miR-24, which was subsequently confirmed by a real-time polymerase chain reaction and luciferase assay. Immunofluorescence labeling was used to measure the cell surface area, and H-leucine incorporation was used to detect the synthesis of total protein in neonatal rat cardiac myocytes (NRCMs) with the overexpression of miR-24. In addition, flow cytometry was performed to observe the alteration in the cell cycle. Statistical analysis was carried out with GraphPad Prism v5.0 and SPSS 19.0. A two-sided P < 0.05 was considered as the threshold for significance.

ResultsThe expression of miR-24 was abnormally increased in TAC rat cardiac tissue (t = -2.938, P < 0.05). TargetScans algorithm-based prediction demonstrated that CDKN1B (p27, Kip1), a cell cycle regulator, was a putative target of miR-24, and was confirmed by luciferase assay. The expression of p27 was decreased in TAC rat cardiac tissue (t = 2.896, P < 0.05). The overexpression of miR-24 in NRCMs led to the decreased expression of p27 (t = 4.400, P < 0.01), and decreased G0/G1 arrest in cell cycle and cardiomyocyte hypertrophy.

ConclusionMiR-24 promotes cardiac hypertrophy partly by affecting the cell cycle through down-regulation of p27 expression.

Animals ; Cardiomegaly ; genetics ; pathology ; Cell Cycle ; genetics ; physiology ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Male ; MicroRNAs ; genetics ; Myocardium ; metabolism ; Myocytes, Cardiac ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo evaluate the effect of Foxo3a gene over-expression on the development of rat ovarian granulosa cells and in prevention of cisplatin-induced ovarian damage in rats.

METHODSRat ovarian granulose cells released mechanically from the ovaries were cultured in vitro and identified with HE staining and immunohistochemical staining for FSHR. A recombinant adenovirus carrying Foxo3a gene was constructed for infecting the granulose cells, and the cell growth and expressions of cyclin D1, p27, Bax, and Bim were detected; the cell apoptosis and cell cycle changes were detected using Hoechst/PI 33342 staining and flow cytometry, respectively. The transfected cells were challenged with cisplatin and the cell apoptosis was detected with flow cytometry.

RESULTSOver 90% of the cultured cells survived and contained more than 95% ovarian granulose cells. Infection of the cells with the recombinant adenovirus resulted in over-expressions of Foxo3a at the mRNA and protein levels at 36 h and 48 h after the infection, respectively. The infected cells showed suppressed proliferation, increased apoptotic rate and cell cycle arrest in G1 phase with increased expressions of Bim, p27, and cyclin D1 but without significant changes in Bax expression. Cisplatin exposure caused a significantly higher apoptosis rate in the infected cells than in the control cells.

CONCLUSIONOver-expression of Foxo3a gene can promote granulose cell apoptosis by increasing Bim expression and cause cell cycle arrest in G1 phase by increasing cyclin D1 and p27 expressions, but can not prevent the toxic effects of cisplatin on ovarian granulosa cells.

Animals ; Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Bcl-2-Like Protein 11 ; Cell Cycle Checkpoints ; Cell Proliferation ; Cells, Cultured ; Cisplatin ; adverse effects ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Female ; Forkhead Box Protein O3 ; Forkhead Transcription Factors ; genetics ; metabolism ; Gene Expression ; Granulosa Cells ; cytology ; drug effects ; Membrane Proteins ; metabolism ; Proto-Oncogene Proteins ; metabolism ; Rats ; Transfection ; bcl-2-Associated X Protein ; metabolism

OBJECTIVE: To investigate the correlation between cyclin-dependent kinase inhibitor p27kip1 and trastuzumab-resistance in gastric cancer.
 METHODS: We selected HER2-overexpressed human gastric cancer cell line NCI-N87 to establish trastuzumab-resistant NCI-N87/TR cell line by stepwise exposure to different doses of trastuzumab. The 50% inhibitory concentration (IC(50)) of trastuzumab and resistance index (RI) were calculated or analyzed by MTT assay. The expression levels of cdk2 and p27kip1 were detected by Western blot. After the treatment with cdk2 inhibitor (Purvalanol A), the expression levels of relevant proteins in NCI-N87/TR cells were detected by Western blot, and the sensitivity to trastuzumab was analyzed by MTT assay. 
 RESULTS: Compared with NCI-N87 cells, the expression of cdk2 was significantly increased in NCI-N87/TR cells (P<0.001), while the expression of p27kip1 showed a significant decrease (P<0.001). Restoration of the p27kip1 protein expression by cdk2 inhibitor (Purvalanol A) increased the sensitivity of NCI-N87/TR to trastuzumab.
 CONCLUSION Down-regulation of p27kip1 might be a mechanism for triggering trastuzumab resistance to gastric cancer cell line NCI-N87.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cyclin-Dependent Kinase 2 ; antagonists & inhibitors ; genetics ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Drug Resistance, Neoplasm ; Humans ; Purines ; pharmacology ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Trastuzumab ; pharmacology

Although it has been suggested that kinesin family member 14 (KIF14) has oncogenic potential in various cancers, including hepatocellular carcinoma (HCC), the molecular mechanism of this potential remains unknown. We aimed to elucidate the role of KIF14 in hepatocarcinogenesis by knocking down KIF14 in HCC cells that overexpressed KIF14. After KIF14 knockdown, changes in tumor cell growth, cell cycle and cytokinesis were examined. We also examined cell cycle regulatory molecules and upstream Skp1/Cul1/F-box (SCF) complex molecules. Knockdown of KIF14 resulted in suppression of cell proliferation and failure of cytokinesis, whereas KIF14 overexpression increased cell proliferation. In KIF14-silenced cells, the levels of cyclins E1, D1 and B1 were profoundly decreased compared with control cells. Of the cyclin-dependent kinase inhibitors, the p27Kip1 protein level specifically increased after KIF14 knockdown. The increase in p27Kip1 was not due to elevation of its mRNA level, but was due to inhibition of the proteasome-dependent degradation pathway. To explore the pathway upstream of this event, we measured the levels of SCF complex molecules, including Skp1, Skp2, Cul1, Roc1 and Cks1. The levels of Skp2 and its cofactor Cks1 decreased in the KIF14 knockdown cells where p27Kip1 accumulated. Overexpression of Skp2 in the KIF14 knockdown cells attenuated the failure of cytokinesis. On the basis of these results, we postulate that KIF14 knockdown downregulates the expression of Skp2 and Cks1, which target p27Kip1 for degradation by the 26S proteasome, leading to accumulation of p27Kip1. The downregulation of Skp2 and Cks1 also resulted in cytokinesis failure, which may inhibit tumor growth. To the best of our knowledge, this is the first report that has identified the molecular target and oncogenic effect of KIF14 in HCC.
Carcinoma, Hepatocellular/*metabolism ; Cyclin-Dependent Kinase Inhibitor p27/genetics/*metabolism ; Cyclins/genetics/metabolism ; *Cytokinesis ; Gene Silencing ; Hep G2 Cells ; Humans ; Kinesin/genetics/*metabolism ; Liver Neoplasms/*metabolism ; Oncogene Proteins/genetics/*metabolism ; Proteasome Endopeptidase Complex/metabolism ; RNA, Messenger/genetics/metabolism ; S-Phase Kinase-Associated Proteins/genetics/metabolism ; *Ubiquitination

OBJECTIVETo explore the effect of downregulation of Tiam1 by siRNA on the esophageal squamous cell carcinoma (ESCC) EC9706 cells, and provide theoretical basis for gene therapy of ESCC using Tiam1 as a molecular target.

METHODSTiam1 siRNA was transfected into EC9706 cells, and expression changes of Tiam1 mRNA and protein after transfection were detected by quantitative real-time PCR and Western blotting. Cell proliferation was analyzed using CCK-8 kit. Cell cycle and apoptosis of the EC9706 cells were assessed by flow cytometry. Cell cycle-related proteins and cell apoptosis-associated proteins were analyzed by Western blotting.

RESULTSCompared with the untreated group and control siRNA group, the relative expression levels of Tiam1 mRNA (1.00 and 0.11 ± 0.02) were not significantly different (P > 0.05). The relative expression levels of Tiam1 mRNA in the Tiam1 siRNA group at 24, 48 and 72 h after transfection were 0.30 ± 0.04, 0.09 ± 0.01 and 0.09 ± 0.006, respectively, significantly lower than that of the untreated group (P < 0.05 for all). The expression level of Tiam1 protein at 24 h after Tiam1 siRNA transfection in the EC9706 cells was 0.11 ± 0.02, significantly lower than that in the un-treated group (0.44 ± 0.05) and control siRNA group (0.44 ± 0.04, P < 0.05 for all). The percentages of G0/G1 cells in the Tiam1 siRNA group, untreated group and control siRNA group were (54.48 ± 2.14)%, (40.69 ± 1.85)% and (41.78 ± 1.31)%, respectively (P < 0.01). The percentages of S phase cells in the Tiam1 siRNA group, untreated group and control siRNA group were (27.18 ± 1.65)%, (32.32 ± 1.15)% and (30.35 ± 1.09)%, respectively (P < 0.01). The expression levels of cyclin D1 protein in the untreated group, control siRNA group and Tiam1 siRNA group were 0.43 ± 0.02, 0.41 ± 0.01 and 0.11 ± 0.02, respectively (P < 0.05). The expression levels of p27 protein in the untreated group, control siRNA group and Tiam1 siRNA group were 0.10 ± 0.01, 0.09 ± 0.02 and 0.20 ± 0.02, respectively (P < 0.05). The ratios of early apoptotic cells in the untreated group, control siRNA group and Tiam1 siRNA group were (10 ± 0.9)%, (10 ± 0.5)% and (27 ± 0.7)%, respectively (P < 0.01). The expression levels of Mcl-1 protein in EC9706 cells of untreated group, control siRNA group and Tiam1 siRNA group were 0.47 ± 0.12, 0.48 ± 0.13 and 0.16 ± 0.02, respectively (P < 0.05). The expression levels of Bcl-2 protein in EC9706 cells of the untreated group, control siRNA group and Tiam1 siRNA group were 0.49 ± 0.08, 0.50 ± 0.05 and 0.04 ± 0.03, respectively (P < 0.05). The caspase-3 activities in the untreated group, control siRNA group and Tiam1 siRNA group were 2.3 ± 0.09, 2.3 ± 0.10 and 16.0 ± 1.50, respectively; and that of caspase-9 were 2.3 ± 0.08, 2.3 ± 0.11 and 14.5 ± 0.9, respectively (P < 0.05 for all).

CONCLUSIONSTiam1 siRNA can significantly inhibit the proliferation of esophageal cancer EC9706 cells, induce cell cycle arrest and cell apoptosis. These effects are related to the regulation of the expressions of cell cycle-related genes (cyclin D1 and p27) and cell apoptosis-related genes (Mcl-1, Bcl-1, caspase-3 and caspase-9) by Tiam1 siRNA.

Apoptosis ; Carcinoma, Squamous Cell ; genetics ; metabolism ; pathology ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Cycle Checkpoints ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Down-Regulation ; Esophageal Neoplasms ; genetics ; metabolism ; pathology ; Guanine Nucleotide Exchange Factors ; genetics ; metabolism ; Humans ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; T-Lymphoma Invasion and Metastasis-inducing Protein 1 ; Transfection

OBJECTIVETo screen the differentially expressed genes in human renal clear-cell carcinoma (RCC) cells using suppression subtractive hybridization (SSH), and to explore their biological function and underlying mechanism in RCC cells.

METHODSTotal RNAs were extracted from human renal clear-cell carcinoma cell line RLC-310 and human normal renal cell line HK-2 cells, and SSH technology was used to construct a RCC cell library of differential expression genes and to screen the most differentially expressed genes. RNA interference vector was constructed to silence the expression of the differentially expressed gene SIPL1 in human renal cell lines RLC-310 and GRC-1. Proliferation index was estimated by cell counting, MTT and tumor xenograft assay. Cell cycle analysis was performed using fluorescence activated cell sorting. Drug resistance potential to adriamycin was assessed by MTT.

RESULTSA subtractive cDNA library of highly expressed genes in the RCC cells was constructed and 12 differentially expressed genes were screened from the subtractive library, in which SIPL1 was the most differently expressed gene in the RCC cell line. SIPL1 overexpression in the RCC cells and clinical samples was confirmed by RT-PCR and Western blot analyses. The shRNA expression plasmid targeting to SIPL1 gene was constructed and transfected into RLC-310 and GRC-1 cells, resulting in downregulation of SIPL1. SIPL1 knockdown inhibited the cell proliferation (P < 0.05) and tumorgenesis. The tumor weights formed by RLC-310 cells transfected with SIPL1 shRNA was (0.22 ± 0.07)g and that of negative control vector was (0.85 ± 0.06)g. The tumor weight formed by GRC-1 cells was (0.32 ± 0.07)g and that of control vectors was (1.21 ± 0.11)g (P < 0.05). SIPL1 shRNA-transfected RLC-310 cells showed that more cells were arrested at G0/G1 phase [(71.13 ± 4.58)%] than that in the negative control RLC-310 cells [(53.27 ± 3.34)%, P < 0.05]. The proportion of G0/G1 phase in the SIPL1 shRNA transfected GRC-1 cells was (73.83 ± 3.97)%, significantly higher than that of (59.33 ± 3.03)% in the negative control GRC-1 cells (P < 0.05), and enhanced their sensitivity to adriamycin (P < 0.05). Silence of SIPL1 caused inactivation of AKT signaling and up-regulated expression of P27(Kip1) and P21(Cip1) proteins.

CONCLUSIONSA differentially expressed gene SIPL1 in the renal clear-cell carcinoma is successfully screened using SSH technology. SIPL1 functions as an oncogene in RCC, and may become a novel molecular target for RCC diagnosis and therapy.

Adenocarcinoma ; metabolism ; pathology ; Adult ; Aged ; Animals ; Antibiotics, Antineoplastic ; pharmacology ; Carcinoma, Renal Cell ; metabolism ; pathology ; Carrier Proteins ; genetics ; metabolism ; Cell Cycle ; Cell Line ; Cell Line, Tumor ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Female ; Humans ; Kidney ; cytology ; Kidney Neoplasms ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Middle Aged ; Neoplasm Transplantation ; Nucleic Acid Hybridization ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transfection ; Tumor Burden

OBJECTIVETo study the effect of small interfering RNA(siRNA) targeting JARID1B gene on the proliferation and apoptosis in HL-60 acute promyelocytic leukemia cell line, and to explore its mechanisms.

METHODSThe JARID1B siRNA was transfected into HL-60 cells using Lipofectamine(TM) 2000(Lipo) vector. The proliferation inhibition by siRNA targeting JARID1B was detected by MTT, cells apoptosis by flow cytometry, the mRNA expression of JARID1B by RT-PCR, the protein expression of JARID1B, Bcl-2, procaspase-9, procaspase-3, c-myc and P27 and histone methylated H3K4 by Western blot.

RESULTSsiRNA targeting JARID1B upregulated histone methylated H3K4 level, inhibited the proliferation of HL-60 cells, and induced the cells apoptosis. After transfection of siRNA targeting JARID1B at 0, 30, 60, 120 nmmol/L for 24 hours, the apoptotic rate were (11.0 ± 3.6)%, (35.2 ± 5.1)%, (52.7 ± 3.8)%, and (62.0 ± 5.7)% respectively (F = 70.27, P < 0.01). The protein expression of P27 was upregulated, and Bcl-2, procaspase-9, procaspase-3, c-myc was down regulated.

CONCLUSIONSJARID1B siRNA upregulates histone methylated H3K4. It reduces HL-60 cells proliferation and apoptosis by up regulating the p27 expression and down regulating the Bcl-2, procaspase-9, procaspase-3, c-myc expression. It might be a new therapeutic targeting for human leukemia.

Apoptosis ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Gene Expression Regulation, Leukemic ; Gene Targeting ; HL-60 Cells ; Histones ; metabolism ; Humans ; Jumonji Domain-Containing Histone Demethylases ; genetics ; Leukemia ; genetics ; Methylation ; Nuclear Proteins ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; RNA Interference ; RNA, Messenger ; genetics ; RNA, Small Interfering ; Repressor Proteins ; genetics

OBJECTIVE: To discuss the expression and the significance of Jab1 p27kip1 in laryngeal squamous cell carcinoma and Hep-2 cells. METHOD: Immunohistochemical method was used to examine the expressions of Jab1 and p27kip1 proteins in 50 cases laryngeal squamous cell carcinomas and 10 cases normal laryngeal tissues adjacent to laryngeal squamous cell carcinoma. Hep-2 cells were transfected with synthetic Jab1 siRNA by Lipofectamine 2000. RT-PCR method was adopted to examine the mRNA expression of the Jab1 and p27kip1 gene in Hep-2 cells which was treated with Jab1 siRNA II. RESULT: Clearly brown staining restricted to nucleus was considered as positive expression of Jab1 and p27kip1 protein. The expression rate of Jab1 protein in laryngeal squamous cell carcinoma was significantly higher than that of normal laryngeal mucosa, and the expression rate of protein p27kip1 in laryngeal squamous cell carcinoma was significantly lower than that of normal laryngeal mucosa. There was a negative relationship between Jab1 and p27kip1 protein in laryngeal squamous cell carcinoma. The expression of Jab1 mRNA was suppressed markedly after transfected by Jab1 siRNA II. As the reaction time increased, the expression of Jab1 mRNA of Hep-2 cells decreased significantly, and the expression of p27kip1 mRNA remained unchanged. CONCLUSION The expression rate of Jab1 protein in laryngeal squamous cell carcinoma is significantly higher than that of normal laryngeal mucosa. There is a negative relationship between Jab1 and p27kiPl protein in laryngeal squamous cell carcinoma. After transfected by Jab1 siRNA II in the Hep-2 cells, the expression of Jab1 mRNA is suppressed markedly. Jab1 siRNA would be a good methodology for the further study.
Adult ; Aged ; Aged, 80 and over ; COP9 Signalosome Complex ; Carcinoma, Squamous Cell ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Laryngeal Neoplasms ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Neoplasm Staging ; Peptide Hydrolases ; genetics ; metabolism ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics

Biomarkers, Tumor ; genetics ; metabolism ; Carcinoma, Transitional Cell ; genetics ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Humans ; Ki-67 Antigen ; metabolism ; Microsatellite Repeats ; Mutation ; Neoplasm Grading ; Neoplasm Staging ; Oligonucleotide Array Sequence Analysis ; Pathology, Molecular ; Receptor, Fibroblast Growth Factor, Type 3 ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; Urinary Bladder Neoplasms ; genetics ; metabolism ; pathology

OBJECTIVETo investigate the expression of cyclin-dependent kinase inhibitor p27kip1 in renal cell carcinoma and its clinical significance.

METHODSThe expressions of p27kip1 mRNA and protein were evaluated using reverse transcription polymerase chain reaction (RT-PCR), Western blotting and immunohistochemistry with tissue chip technique in renal cell carcinoma (RCC) tissues, adjacent tissues and 786-0 cell line. The relationship between the expression of p27kip1 and the tumor size, the clinical stage, pathological type and stage were evaluated, and the results by the 3 methods were analyzed to evaluate the relationship between the mRNA and protein of p27kip1.

RESULTSThe expression of p27kip1 protein (detected by immunohistochemistry and Western blotting) in RCC tissue was significantly lower than that in the adjacent normal tissues (P<0.05). The expression of p27kip1 mRNA (by RT-PCR) showed no significant difference between the two groups. p27kip1 protein expression was found to be inversely correlated to the tumor grade and clinical stage (P<0.05). Western blotting and immunohistochemistry showed a high coincidence rate in the detection of P27kip1 protein expression in RCC samples (P<0.001, K=0.828).

CONCLUSIONp27kip1 mRNA expression shows no difference between RCC and normal tissues, while the protein expression is significantly lower in the cancer tissues, suggesting a regulatory mechanism of p27kip1 expression at the transcriptional level. Low expression of p27kip1 protein may promote the development and progression of RCC. p27kip1 protein may serve as a diagnostic and prognostic marker of RCC.

Blotting, Western ; Carcinoma, Renal Cell ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Female ; Humans ; Immunohistochemistry ; Kidney Neoplasms ; genetics ; metabolism ; pathology ; Reverse Transcriptase Polymerase Chain Reaction