CDK1

Gene Summary

Gene:CDK1; cyclin dependent kinase 1
Aliases: CDC2, CDC28A, P34CDC2
Location:10q21.2
Summary:The protein encoded by this gene is a member of the Ser/Thr protein kinase family. This protein is a catalytic subunit of the highly conserved protein kinase complex known as M-phase promoting factor (MPF), which is essential for G1/S and G2/M phase transitions of eukaryotic cell cycle. Mitotic cyclins stably associate with this protein and function as regulatory subunits. The kinase activity of this protein is controlled by cyclin accumulation and destruction through the cell cycle. The phosphorylation and dephosphorylation of this protein also play important regulatory roles in cell cycle control. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2009]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:cyclin-dependent kinase 1
Source:NCBIAccessed: 14 March, 2017

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 14 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • bcl-2-Associated X Protein
  • Purines
  • Cyclin B1
  • Up-Regulation
  • Bladder Cancer
  • Cyclin-Dependent Kinases
  • Viral Matrix Proteins
  • Retinoic Acid
  • RTPCR
  • Uteroglobin
  • Radiation Tolerance
  • Transfection
  • Phosphorylation
  • ral GTP-Binding Proteins
  • Transcription
  • Cyclin B
  • Staurosporine
  • Topoisomerase II Inhibitors
  • Neoplasm Invasiveness
  • Signal Transduction
  • Cell Proliferation
  • Apoptosis
  • Chromosome 10
  • Xenopus Proteins
  • Spindle Apparatus
  • CDC2 Protein Kinase
  • Lung Cancer
  • Breast Cancer
  • Tumor Suppressor Proteins
  • Cell Cycle
  • Cancer Gene Expression Regulation
  • Xanthones
  • p21-Activated Kinases
  • bcl-X Protein
  • Cell Cycle Proteins
  • S-Phase Kinase-Associated Proteins
  • Messenger RNA
  • Tumor Burden
  • Tissue Array Analysis
  • Protein Kinase Inhibitors
  • Wnt3 Protein
  • Proportional Hazards Models
Tag cloud generated 14 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: CDK1 (cancer-related)

Dai L, Wang G, Pan W
Andrographolide Inhibits Proliferation and Metastasis of SGC7901 Gastric Cancer Cells.
Biomed Res Int. 2017; 2017:6242103 [PubMed] Free Access to Full Article Related Publications
To explore the mechanisms by which andrographolide inhibits gastric cancer cell proliferation and metastasis, we employed the gastric cell line SGC7901 to investigate the anticancer effects of andrographolide. The cell survival ratio, cell migration and invasion, cell cycle, apoptosis, and matrix metalloproteinase activity were assessed. Moreover, western blotting and real-time PCR were used to examine the protein expression levels and the mRNA expression levels, respectively. The survival ratio of cells decreased with an increasing concentration of andrographolide in a dose-dependent manner. Consistent results were also obtained using an apoptosis assay, as detected by flow cytometry. The cell cycle was blocked at the G2/M2 phase by andrographolide treatment, and the proportion of cells arrested at G1/M was enhanced as the dose increased. Similarly, wound healing and Transwell assays showed reduced migration and invasion of the gastric cancer cells at various concentrations of andrographolide. Andrographolide can inhibit cell proliferation, invasion, and migration, block the cell cycle, and promote apoptosis in SGC7901 cells. The mechanisms may include upregulated expression of Timp-1/2, cyclin B1, p-Cdc2, Bax, and Bik and downregulated expression of MMP-2/9 and antiapoptosis protein Bcl-2.

Zhang H, Zhong J, Bian Z, et al.
Long non-coding RNA CCAT1 promotes human retinoblastoma SO-RB50 and Y79 cells through negative regulation of miR-218-5p.
Biomed Pharmacother. 2017; 87:683-691 [PubMed] Related Publications
OBJECTIVE: To investigate the regulatory role and potential mechanism of long non-coding RNAs (lncRNA) in human retinoblastoma (RB).
METHODS: The lncRNA profile in RB tissues were analyzed by microarray and quantitative reverse transcription PCR (qRT-PCR). One of the identified lncRNAs (LncRNA CCAT1) was selected for further experiments. SO-RB50 and Y79 cells were transfected with negative control, siRNA targeting lncRNA CCAT1 (si-CCAT1) and si-CCAT1+miR218-5p inhibitor, respectively. lncRNA CCAT1 expression was measured by qRT-PCR. Cell proliferation, migration and invasion were detected by CCK8, wound scratching, and transwell assay, respectively. Apoptosis and cell cycle distribution were assessed by flow cytometry. Apoptosis- (cle-caspase-3, cle-caspase-9, Bax and Bcl-2) and cell cycle-related protein expression (cyclin B1, CDC2 and p-CDC2 (Thr161)) were analyzed by Western blot.
RESULTS: lncRNA CCAT1 expression in SO-RB50 and Y79 cells was significantly inhibited after si-CCAT1 transfection (P<0.01). Both RB cells exhibited significantly reduced proliferation, migration and invasion abilities, but markedly increased apoptosis at 48h after si-CCAT1 transfection (P<0.05 or 0.01). RB cells in si-CCAT1+miR218-5p inhibitor group had significantly higher proliferation, migration and invasion, but notably lower apoptosis compared with si-CCAT1 group at 24 and 48h after transfection (all P<0.05 or 0.01). si-CCAT1 significantly increased the expression of cle-caspase-3, cle-caspase-9, Bax, but decreased Bcl-2 expression (P<0.01). The proportion of G2/M SO-RB50 and Y79 cells in siCCAT1 group was significantly increased compared with negative control group (P<0.01). LncRNA CCAT1 interference significantly reduced the expression of cyclin B1, CDC2 and p-CDC2 (Thr161) (P<0.01).
CONCLUSION: LncRNA CCAT1 promotes the proliferation migration and invasion, and reduces cell apoptosis of SO-RB50 and Y79 cells, probably through negative modulation of miR-218-5p. Our study suggested lncRNA CCAT1 as a potential biomarker and therapeutic target for RB.

Liu L, Xu Y, Reiter RJ, et al.
Inhibition of ERK1/2 Signaling Pathway is Involved in Melatonin's Antiproliferative Effect on Human MG-63 Osteosarcoma Cells.
Cell Physiol Biochem. 2016; 39(6):2297-2307 [PubMed] Related Publications
BACKGROUND: In a previous study, we found that melatonin inhibits MG-63 osteosarcoma cell proliferation; however, the underlying mechanisms remain elusive. Mitogen-activated protein kinase (MAPK) and Akt signaling pathways play key roles in the anticancer effects of melatonin.
AIMS: The present study investigated whether MAPK and Akt signaling pathways are involved in melatonin's antiproliferative actions on the human MG-63 osteosarcoma cells.
METHODS/RESULTS: Western blot analysis confirmed that melatonin significantly inhibited phosphorylation of ERK1/2 but not p38, JNK, or Akt. The expression of ERK1/2, p38, JNK, and Akt was not altered by melatonin. PD98059 and melatonin alone, and especially in combination, significantly inhibited cell proliferation. The changes included G1 and G2/M phase arrest of the cell cycle, and a downregulation of the expression at both the protein and mRNA levels of cyclin D1 and CDK4 (related to the G1 phase) and of cyclin B1 and CDK1 (related to the G2/M phase) as measured by flow cytometry after propidium iodide staining, and both western blot and real-time PCR, respectively. Furthermore, the combination of PD98059 and melatonin synergistically and markedly augmented the action of either agent alone. Co-immunoprecipitation further confirmed that there was an interaction between p-ERK1/2 and cyclin D1, CDK4, cyclin B1, or CDK1, which was blunted in the presence of melatonin or PD98059.
CONCLUSION: These findings suggest that melatonin's antiproliferative action is mediated by inhibition of the ERK1/2 signaling pathway rather than the p38, JNK, or Akt pathways.

Duangprompo W, Aree K, Itharat A, Hansakul P
Effects of 5,6-Dihydroxy-2,4-Dimethoxy-9,10-Dihydrophenanthrene on G2/M Cell Cycle Arrest and Apoptosis in Human Lung Carcinoma Cells.
Am J Chin Med. 2016; 44(7):1473-1490 [PubMed] Related Publications
5,6-dihydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene (HMP) is an active compound isolated from the rhizome extracts of Dioscorea membranacea Pierre, a Thai medicinal plant. This study aimed to investigate the growth-inhibitory and apoptosis-inducing effects of HMP in human lung cancer A549 cells. The antiproliferative and cytotoxic effects of HMP were analyzed by a Sulforhodamine B assay. Cell division, cell cycle distribution and membrane asymmetry changes were each performed with different fluorescent dyes and then analyzed by flow cytometry. Real-time PCR and immunoblotting were used to detect cell cycle- and apoptosis-related mRNA levels and proteins, respectively. The nuclear morphology of the cells stained with DAPI and DNA fragmentation were detected by fluorescence microscopy and gel electrophoresis, respectively. The results showed that HMP exerted strong antiproliferative and cytotoxic activities in A549 cells with the highest selectivity index. It halted the cell cycle in [Formula: see text]/M phase via down-regulation of the expression levels of regulatory proteins Cdc25C, Cdk1 and cyclinB1. In addition, HMP induced early apoptotic cells with externalized phosphatidylserine and subsequent apoptotic cells in sub-[Formula: see text] phase. HMP increased caspase-3 activity and levels of the cleaved (active) form of caspase-3 whose actions were supported by the cleavage of its target PARP, nuclear condensation and DNA apoptotic ladder. Moreover, HMP significantly increased the mRNA and protein levels of proapoptotic Bax as well as promoted subsequent caspase-9 activation and BID cleavage, indicating HMP-induced apoptosis via both intrinsic and extrinsic pathways. These data support, for the first time, the potential role of HMP as a cell-cycle arrest and apoptosis-inducing agent for lung cancer treatment.

Hass HG, Vogel U, Scheurlen M, Jobst J
Gene-expression Analysis Identifies Specific Patterns of Dysregulated Molecular Pathways and Genetic Subgroups of Human Hepatocellular Carcinoma.
Anticancer Res. 2016; 36(10):5087-5095 [PubMed] Related Publications
BACKGROUND: Hepatocellular carcinoma comprises of a group of heterogeneous tumors of different etiologies. The multistep process of liver carcinogenesis involves various genetic and phenotypic alterations. The molecular pathways and driver mutations involved are still under investigation.
MATERIALS AND METHODS: DNA micorarray technology was used to identify differentially expressed genes between human hepatocarcinoma and non-tumorous liver tissues to establish a unique specific gene-expression profile independent of the underlying liver disease. The validity of this global gene-expression profile was tested for its robustness against biopsies from other liver entities (cirrhotic and non-cirrhotic liver) by diagnosing HCC in blinded samples.
RESULTS: Most of the consistently and strongly overexpressed genes were related to cell-cycle regulation and DNA replication [27 genes, e.g. cyclin B1, karyopherin alpha 2 (KPNA2), cyclin-dependent kinase 2 (CDC2)], G-protein depending signaling [e.g. Rac GTPase activating protein 1 (RACGAP1), Rab GTPase YPT1 homolog (RAB1), and ADP-ribosylation factor-like 2 (ARL2)] and extracellular matrix re-modelling or cytoskeleton structure [22 genes, e.g. serine proteinase inhibitor 1 kazal-type (SPINK1), osteopontin (OPN), secreted protein acidic and rich in cysteine (SPARC), collagen type 1 alpha2 (COL1A2), integrin alpha6 (ITGA6), and metalloproteinase 12 (MMP12)]. Furthermore, significantly differentially expressed genes (e.g. calcium-binding proteins, G-proteins, oncofetal proteins) in relation to tumor differentiation were detected using gene-expression analysis.
CONCLUSION: It is suggested that these significantly dysregulated genes are highly specific and potentially utilizable as prognostic markers and may lead to a better understanding of human hepatocarcinogenesis.

Mohammadi A, Mansoori B, Aghapour M, et al.
The Urtica dioica extract enhances sensitivity of paclitaxel drug to MDA-MB-468 breast cancer cells.
Biomed Pharmacother. 2016; 83:835-842 [PubMed] Related Publications
INTRODUCTION: Due to the chemo resistant nature of cancer cells and adverse effects of current therapies, researchers are looking for the most efficient therapeutic approach which has the lowest side effects and the highest toxicity on cancer cells. The aim of the present study was to investigate the synergic effect of Urtica dioica extract in combination with paclitaxel on cell death and invasion of human breast cancer MDA-MB-468 cell line.
MATERIALS AND METHODS: To determine the cytotoxic effects of Urtica dioica extract with paclitaxel, MTT assay was performed. The scratch test was exploited to assess the effects of Urtica dioica, Paclitaxel alone and combination on migration of cancer cells. The expression levels of snail-1, ZEB1, ZEB2, twist, Cdc2, cyclin B1 and Wee1 genes were quantified using qRT-PCR and western blot performed for snail-1expression. The effects of plant extract, Paclitaxel alone and combination on different phases of cell cycle was analyzed using flow cytometry.
RESULTS: Results of MTT assay showed that Urtica dioica significantly destroyed cancer cells. Interestingly, Concurrent use of Urtica dioica extract with paclitaxel resulted in decreased IC50 dose of paclitaxel. Moreover, findings of scratch assay exhibited the inhibitory effects of Urtica dioica, Paclitaxel alone and combination on migration of MDA-MB-468 cell line. Our findings also demonstrated that the extract substantially decreased the Snail-1 and related gene expression. Ultimately, Cell cycle arrest occurred at G2/M phase post-treatment by deregulating Cdc2 and wee1.
CONCLUSIONS: Our results demonstrated that the dichloromethane extract of Urtica dioica inhibit cell growth and migration. Also, Urtica dioica extract substantially increased sensitivity of breast cancer cells to paclitaxel. Therefore, it can be used as a potential candidate for treatment of breast cancer with paclitaxel.

Choi HE, Shin JS, Leem DG, et al.
6-(3,4-Dihydro-1H-isoquinoline-2-yl)-N-(6-methoxypyridine-2-yl) nicotinamide-26 (DIMN-26) decreases cell proliferation by induction of apoptosis and downregulation of androgen receptor signaling in human prostate cancer cells.
Chem Biol Interact. 2016; 260:196-207 [PubMed] Related Publications
Previously, we reported that 6-(3,4-dihydro-1H-isoquinolin-2-yl)-N-(6-methylpyridin-2-yl) nicotinamide (DIMN) analogues inhibited the growth of prostate cancer cells as an anti-androgenic compound. In the present study, we evaluated cytotoxic effects of these DIMN derivatives and found that DIMN-26 most potently inhibited the proliferation of the LNCap-LN3 androgen-dependent and DU145 androgen-independent prostate cancer cells through induction of G2/M phase cell cycle arrest and subsequent apoptosis. The G2/M phase arrest was found due to increases in the activation of cdc2 (also known as cyclin-dependent kinase 1, CDK1)/cyclin B1 complex. DIMN-26 also induced apoptosis in LNCap-LN3 and DU145 prostate cancer cells through activation of caspase-3, -8, and -9, and cleavage of poly(ADP-ribose) polymerase-1 (PARP-1). In addition, DIMN-26 caused the dephosphorylation and mitochondrial accumulation of Bad protein and induced the loss of mitochondria membrane potential, consequently releasing cytochrome c into the cytosol of the cell. Furthermore, overexpression of AKT protein significantly reduced DIMN-26-induced PARP-1 cleavage and p-Bad decrease and cdc2 activation. In addition, DIMN-26 inhibited the 5α-dihydrotestosterone (DHT)-induced cell growth and proliferation and nuclear translocation and transcriptional activities of androgen receptor (AR) in LNCap-LN3 prostate cancer cells. Consistent with these findings, DIMN-26 significantly inhibited the DHT-induced expression of AR-response genes (ARGs), such as prostate-specific antigen (PSA), AR, β2-microglobulin (B2M), selenoprotein P (SEPP1), and ste20-related proline-alanine-rich kinase (SPAK) in LNCap-LN3 prostate cancer cells. Taken together, these results suggest that DIMN-26 plays a therapeutic role not only in induction of G2/M arrest and apoptosis but also in suppression of androgen receptor signaling in androgen-dependent and androgen-independent prostate cancer cells.

Abaza MS, Afzal M, Al-Attiyah RJ, Guleri R
Methylferulate from Tamarix aucheriana inhibits growth and enhances chemosensitivity of human colorectal cancer cells: possible mechanism of action.
BMC Complement Altern Med. 2016; 16(1):384 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Natural products are valuable sources for anticancer agents. In the present study, methylferulate (MF) was identified for the first time from Tamarix aucheriana. Spectral data were used for identification of MF. The potential of MF to control cell growth, cell cycle, apoptosis, generation of reactive oxygen species (ROS), cancer cell invasion, nuclear factor kappa B (NFkB) DNA-binding activity and proteasomal activities, as well as the enhancement of chemosensitivity in human colorectal cancer cells, were evaluated. The possible molecular mechanism of MF's therapeutic efficacy was also assessed.
METHODS: Column chromatography and spectral data were used for isolation and identification of MF. MTT, immunofluorescence, flow cytometry, in vitro invasion, fluoremetry, EIA and Real time qPCR were used to measure antiproliferative, chemo-sensitizing effects and other biochemical parameters.
RESULTS: MF showed a dose-dependent anti-proliferative effect on colorectal cancer cells (IC50 = 1.73 - 1.9 mM) with a nonsignificant cytotoxicity toward normal human fibroblast. Colony formation inhibition (P ≤ 0.001, 0.0001) confirmed the growth inhibition by MF. MF arrested cell cycle progression in the S and G2/M phases; induced apoptosis and ROS generation; and inhibited NF-kB DNA-binding activity, proteasomal activities and cell invasion in colorectal cancer cells. MF up-regulated cyclin-dependent kinase inhibitors (p19 (INK4D), p21(WAF1/CIP1), p27(KIP1)), pro-apoptotic gene expression (Bax, Bad, Apaf1, Bid, Bim, Smac) and caspases (caspase 2, 3, 6, 7, 8, 9). Moreover, MF down-regulated cyclin-dependent kinases (Cdk1, Cdk2) and anti-apoptotic gene expression (c-IAP-1, c-IAP-2, Bcl2,FLIP). In addition, MF differentially potentiated the sensitivity of colorectal cancer cells to standard chemotherapeutic drugs.
CONCLUSION: MF showed a multifaceted anti-proliferative and chemosensitizing effects. These results suggest the chemotherapeutic and co-adjuvant potential of MF.

Liu KC, Shih TY, Kuo CL, et al.
Sulforaphane Induces Cell Death Through G2/M Phase Arrest and Triggers Apoptosis in HCT 116 Human Colon Cancer Cells.
Am J Chin Med. 2016; 44(6):1289-1310 [PubMed] Related Publications
Sulforaphane (SFN), an isothiocyanate, exists exclusively in cruciferous vegetables, and has been shown to possess potent antitumor and chemopreventive activity. However, there is no available information that shows SFN affecting human colon cancer HCT 116 cells. In the present study, we found that SFN induced cell morphological changes, which were photographed by contrast-phase microscopy, and decreased viability. SFN also induced G2/M phase arrest and cell apoptosis in HCT 116 cells, which were measured with flow cytometric assays. Western blotting indicated that SFN increased Cyclin A, cdk 2, Cyclin B and WEE1, but decreased Cdc 25C, cdk1 protein expressions that led to G2/M phase arrest. Apoptotic cell death was also confirmed by Annexin V/PI and DAPI staining and DNA gel electrophoresis in HCT 116 cells after exposure to SFN. The flow cytometric assay also showed that SFN induced the generation of reactive oxygen species (ROS) and Ca[Formula: see text] and decreased mitochondria membrane potential and increased caspase-8, -9 and -3 activities in HCT 116 cell. Western blotting also showed that SFN induced the release of cytochrome c, and AIF, which was confirmed by confocal microscopy examination. SFN induced ER stress-associated protein expression. Based on those observations, we suggest that SFN may be used as a novel anticancer agent for the treatment of human colon cancer in the future.

Jagadish N, Gupta N, Agarwal S, et al.
Sperm-associated antigen 9 (SPAG9) promotes the survival and tumor growth of triple-negative breast cancer cells.
Tumour Biol. 2016; 37(10):13101-13110 [PubMed] Related Publications
Recently, we demonstrated the association of sperm-associated antigen 9 (SPAG9) expression with breast cancer. Among breast cancer, 15 % of the cancers are diagnosed as triple-negative breast cancers (TNBC) based on hormone receptor status and represent an important clinical challenge because of lack of effective available targeted therapy. Therefore, in the present investigation, plasmid-based small hairpin (small hairpin RNA (shRNA)) approach was used to ablate SPAG9 in aggressive breast cancer cell line model (MDA-MB-231) in order to understand the role of SPAG9 at molecular level in apoptosis, cell cycle, and epithelial-to-mesenchymal transition (EMT) signaling. Our data in MDA-MB-231 cells showed that ablation of SPAG9 resulted in membrane blebbing, increased mitochondrial membrane potential, DNA fragmentation, phosphatidyl serine surface expression, and caspase activation. SPAG9 depletion also resulted in cell cycle arrest in G0-G1 phase and induced cellular senescence. In addition, in in vitro and in vivo xenograft studies, ablation of SPAG9 resulted in upregulation of p21 along with pro-apoptotic molecules such as BAK, BAX, BIM, BID, NOXA, AIF, Cyto-C, PARP1, APAF1, Caspase 3, and Caspase 9 and epithelial marker, E-cadherin. Also, SPAG9-depleted cells showed downregulation of cyclin B1, cyclin D1, cyclin E, CDK1, CDK4, CDK6, BCL2, Bcl-xL, XIAP, cIAP2, MCL1, GRP78, SLUG, SNAIL, TWIST, vimentin, N-cadherin, MMP2, MMP3, MMP9, SMA, and β-catenin. Collectively, our data suggests that SPAG9 promotes tumor growth by inhibiting apoptosis, altering cell cycle, and enhancing EMT signaling in in vitro cells and in vivo mouse model. Hence, SPAG9 may be a potential novel target for therapeutic use in TNBC treatment.

Huang X, Zhou W, Zhang Y, Liu Y
High Expression of PTGR1 Promotes NSCLC Cell Growth via Positive Regulation of Cyclin-Dependent Protein Kinase Complex.
Biomed Res Int. 2016; 2016:5230642 [PubMed] Free Access to Full Article Related Publications
Lung cancer has been the most common cancer and the main cause of cancer-related deaths worldwide for several decades. PTGR1 (prostaglandin reductase 1), as a bifunctional enzyme, has been involved in the occurrence and progression of cancer. However, its impact on human lung cancer is rarely reported. In this study, we found that PTGR1 was overexpressed in lung cancer based on the analyses of Oncomine. Moreover, lentivirus-mediated shRNA knockdown of PTGR1 reduced cell viability in human lung carcinoma cells 95D and A549 by MTT and colony formation assay. PTGR1 depletion led to G2/M phase cell cycle arrest and increased the proportion of apoptotic cells in 95D cells by flow cytometry. Furthermore, silencing PTGR1 in 95D cells resulted in decreased levels of cyclin-dependent protein kinase complex (CDK1, CDK2, cyclin A2, and cyclin B1) by western blotting and then PTGR1 is positively correlated with cyclin-dependent protein by using the data mining of the Oncomine database. Therefore, our findings suggest that PTGR1 may play a role in lung carcinogenesis through regulating cell proliferation and is a potential new therapeutic strategy for lung cancer.

Zhang Y, Ran Y, Xiong Y, et al.
Effects of TMEM9 gene on cell progression in hepatocellular carcinoma by RNA interference.
Oncol Rep. 2016; 36(1):299-305 [PubMed] Related Publications
Hepatocellular carcinoma (HCC) is a malignant tumor that has become a global health issue. The aim of the present study was to examine the role of transmembrane protein 9 (TMEM9) in cell progression, such as cell growth, cell cycle, cell metastasis of hepatoma cells, and to discuss the TMEM9 gene‑encoding protein as a potential therapy target of hepatoma. RT-qPCR was performed to examine TMEM9 expression in tumor tissues and adjacent tissues of patients with liver cancer. siRNAs were used to interfere TMEM9 in HepG2 and 7721 cells. A CCK-8 assay was performed to evaluate cell growth at 24, 48 and 72 h. Cell cycle and apoptosis were analyzed using flow cytometry. Transwell assays were used to determine cell invasion, migration and adhesion. The results showed that TMEM9 was expressed abnormally in liver cancers. TMEM9 expression increased significantly in the 34 examined patients. TMEM9 knockdown inhibited proliferation in the HepG2 and 7721 cells. The flow cytometric analysis revealed that TMEM9 knockdown by RNA interference resulted in G1 arrest and induced apoptosis. Cell invasion, migration and adhesion ability were also decreased. Western blotting indicated that expression of the cell cycle‑related proteins CDK1, EIF3H, RPL10L, S100A10, CCNB1 and CCNB2 was significantly decreased. In conclusion, TMEM9 plays an important role in the cell growth of hepatoma cells.

Feng W, Li HC, Xu K, et al.
SHCBP1 is over-expressed in breast cancer and is important in the proliferation and apoptosis of the human malignant breast cancer cell line.
Gene. 2016; 587(1):91-7 [PubMed] Related Publications
BACKGROUND: SHC SH2-binding protein 1, a member of Src homolog and collagen homolog (Shc) family, has been recently identified in different contexts in unbiased screening assays. It has been reported to be over-expressed in several malignant cancers.
METHODS: Immunohistochemistry of SHCBP1 on 128 breast cancer tissues and adjacent normal tissues were used to evaluate the prognostic significance of SHCBP1. Survival analyses were performed by Kaplan-Meier method. CRISPR/CAS9 method was used to knockout SHCBP1 expression. CRISPR/CAS9 technology was used to knockout SHCBP1 in 2 breast cancer cell lines. MTT assay, BrdU assay, colony formation assay, cell cycle assay and apoptosis analysis in MCF-7 and MDA-MB-231 cell lines were carried out to evaluate the effects of SHCBP1 on breast cancer in vitro.
RESULTS: Immunohistochemical analysis revealed SHCBP1 was significantly up-regulated in breast cancer tissues compared with adjacent normal tissues (82 of 128, 64%). Over-expressed SHCBP1 was correlated with advanced clinical stage and poorer survival. Ablation of SHCBP1 inhibited the proliferation in vitro. SHCBP1 knockout increased cyclin-dependent kinase inhibitor p21, and decreased the Cyclin B1 and CDK1.
CONCLUSION: Our study suggests SHCBP1 is dysregulated expressed in breast cancer and plays a critical role in cancer progression, which can be a potential prognosis predictor of breast cancer.

Bukowska B, Rogalska A, Forma E, et al.
Why a Combination of WP 631 and Epo B is an Improvement on the Drugs Singly - Involvement in the Cell Cycle and Mitotic Slippage.
Asian Pac J Cancer Prev. 2016; 17(3):1299-308 [PubMed] Related Publications
Our previous studies clearly demonstrated that a combination of WP 631 and Epo B has higher activity against ovarian cancer cells than either of these compounds used separately. In order to fully understand the exact mechanism of action in combination, we assessed effects on the cell cycle of SKOV-3 cells. We evaluated three control points essential for WP 631 and Epo B action to determine which cell cycle-regulating proteins (CDK1/cyclin B complex, EpCAM or HMGB1) mediate activity. The effects of the drug on the cell cycle were measured based on the nuclear DNA content using flow cytometry. Expression of cell cycle-regulating genes was analyzed using real-time PCR. It was discovered that WP 631, at the tested concentration, did not affect the SKOV-3 cell cycle. Epo B caused significant G2/M arrest, whereas the drug combination induced stronger apoptosis and lower mitotic arrest than Epo B alone. This is very important information from the point of view of the fight against cancer, as, while mitotic arrest in Epo B-treated cells could be overcame after DNA damage repair, apoptosis which occurs after mitotic slippage in combination-treated cells is irreversible. It clearly explains the higher activity of the drug combination in comparison to Epo B alone. Epo B acts via the CDK1/cyclin B complex and has the ability to inhibit CDK1, which may be a promising strategy for ovarian cancer treatment in the future. The drug combination diminishes EpCAM and HMGB1 expression to a greater degree than either WP 631 and Epo B alone. Owing to the fact that the high expression of these two proteins is a poor prognostic factor for ovarian cancer, a decrease in their expression, observed in our studies, may result in improved efficacy of cancer therapy. The presented findings show that the combination of WP 631 and Epo B is a better therapeutic option than either of these drugs alone.

Cheng C, Jiao JT, Qian Y, et al.
Curcumin induces G2/M arrest and triggers apoptosis via FoxO1 signaling in U87 human glioma cells.
Mol Med Rep. 2016; 13(5):3763-70 [PubMed] Free Access to Full Article Related Publications
It has previously been demonstrated that curcumin possesses an antitumor activity, which is associated with its ability to induce G2/M cell cycle arrest and apoptosis. However the detailed underlying mechanisms remain unclear. The present study aimed to investigate the efficacy and underlying mechanism of curcumin‑induced cell cycle arrest and apoptosis in U87 human glioblastoma cells. By immunofluorescence staining, subcellular fractionation and western blotting, the present study demonstrated that curcumin was able to induce G2/M cell cycle arrest and apoptosis by increasing the expression levels of cyclin G2, cleaved caspase‑3 and Fas ligand (FasL), and decreasing the expression of cyclin‑dependent kinase 1 (CDK1). In addition, increased expression of forkhead box protein O1 (FoxO1) and decreased expression of phosphorylated (p)‑FoxO1 were detected in the curcumin‑treated U87 cells. Curcumin was also able to induce the translocation of FoxO1 from the cytoplasm to the nucleus. Furthermore, following knockdown of FoxO1 expression in curcumin‑treated U87 cells using FoxO1 small interfering RNA, the expression levels of cyclin G2, cleaved caspase‑3 and FasL were inhibited; however, the expression levels of CDK1 were not markedly altered. Notably, following knockdown of CDK1 expression under normal conditions, the total expression of FoxO1 was not affected; however, p‑FoxO1 expression was decreased and FoxO1 nuclear expression was increased. Furthermore, curcumin‑induced G2/M cell cycle arrest and apoptosis could be attenuated by FoxO1 knockdown. These results indicated that curcumin may induce G2/M cell cycle arrest and apoptosis in U87 cells by increasing FoxO1 expression. The present study identified a novel mechanism underlying the antitumor effects of curcumin, and may provide a theoretical basis for the application of curcumin in glioma treatment.

Pan XW, Chen L, Hong Y, et al.
EIF3D silencing suppresses renal cell carcinoma tumorigenesis via inducing G2/M arrest through downregulation of Cyclin B1/CDK1 signaling.
Int J Oncol. 2016; 48(6):2580-90 [PubMed] Related Publications
There are no effective therapies for advanced renal cell carcinoma (RCC), except for VEGFR inhibitors with only ~50% response rate. To identify novel targets and biomarkers for RCC is of great importance in treating RCC. In this study, we observed that eukaryotic initiation factor 3d (EIF3D) expression was significantly increased in RCC compared with paracarcinoma tissue using immunohistochemistry staining and western blot analysis. Furthermore, bioinformatics meta-analysis using ONCOMINE microarray datasets showed that EIF3D mRNA expressions in CCRCC tissue specimens were significantly higher than that in normal tissue specimens. In addition, RCC tissue microarray demonstrated that elevated EIF3D expression was positively correlated with TNM stage and tumor size. EIF3D silencing in human 786-O and ACHN CCRCC cell lines by RNA interference demonstrated that EIF3D knockdown obviously inhibited cell proliferation and colony formation, caused G2/M arrest through downregulation of Cyclin B1 and Cdk1 and upregulation of p21, and induced apoptosis shown by sub-G1 accumulation and RARP cleavage. Moreover, correlation analysis using ONCOMINE microarray datasets indicated that increased EIF3D mRNA expression was positively correlated to PCNA, Cyclin B1 and CDK1 mRNA expression in RCC. Collectively, these results provide reasonable evidences that EIF3D may function as a potential proto-oncogene that participates in the occurrence and progression of RCC.

Hasanpourghadi M, Karthikeyan C, Pandurangan AK, et al.
Targeting of tubulin polymerization and induction of mitotic blockage by Methyl 2-(5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) in human cervical cancer HeLa cell.
J Exp Clin Cancer Res. 2016; 35:58 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Microtubule Targeting Agents (MTAs) including paclitaxel, colchicine and vinca alkaloids are widely used in the treatment of various cancers. As with most chemotherapeutic agents, adverse effects and drug resistance are commonly associated with the clinical use of these agents. Methyl 2-(5-fluoro-2-hydroxyphenyl)-1H- benzo[d]imidazole-5-carboxylate (MBIC), a benzimidazole derivative displays greater toxicity against various cancer compared to normal human cell lines. The present study, focused on the cytotoxic effects of MBIC against HeLa cervical cancer cells and possible actions on the microtubule assembly.
METHODS: Apoptosis detection and cell-cycle assays were performed to determine the type of cell death and the phase of cell cycle arrest in HeLa cells. Tubulin polymerization assay and live-cell imaging were performed to visualize effects on the microtubule assembly in the presence of MBIC. Mitotic kinases and mitochondrial-dependent apoptotic proteins were evaluated by Western blot analysis. In addition, the synergistic effect of MBIC with low doses of selected chemotherapeutic actions were examined against the cancer cells.
RESULTS: Results from the present study showed that following treatment with MBIC, the HeLa cells went into mitotic arrest comprising of multi-nucleation and unsegregated chromosomes with a prolonged G2-M phase. In addition, the HeLa cells showed signs of mitochondrial-dependant apoptotic features such as the release of cytochrome c and activation of caspases. MBIC markedly interferes with tubulin polymerization. Western blotting results indicated that MBIC affects mitotic regulatory machinery by up-regulating BubR1, Cyclin B1, CDK1 and down-regulation of Aurora B. In addition, MBIC displayed synergistic effect when given in combination with colchicine, nocodazole, paclitaxel and doxorubicin.
CONCLUSION: Taken together, our study demonstrated the distinctive microtubule destabilizing effects of MBIC against cervical cancer cells in vitro. Besides that, MBIC exhibited synergistic effects with low doses of selected anticancer drugs and thus, may potentially reduce the toxicity and drug resistance to these agents.

Yi X, Li Y, Zai H, et al.
KLF8 knockdown triggered growth inhibition and induced cell phase arrest in human pancreatic cancer cells.
Gene. 2016; 585(1):22-7 [PubMed] Related Publications
BACKGROUND: The transcription factor Krüppel-like factor 8 (KLF8) plays an important role in tumor development and growth, but its role in pancreatic cancer (PC) is not clear.
METHODS: KLF8 expression in human PC cell lines and tumor tissues was measured by quantitative real-time polymerase chain reaction and Western blot analyses. The effects of lentivirus mediated knockdown of KLF8 on proliferation and growth in Panc-1 pancreatic cancer cells were examined.
RESULTS: KLF8 was overexpressed in 5 pancreatic cancer cell lines and in samples from patients with PC. In Panc-1 cells, KLF8 knockdown inhibited cell proliferation, tumorigenicity, and induced G2/M phase arrest. KLF8 knockdown suppressed PC tumor growth in nude mice model. Western blot analysis showed that KLF8 knockdown in Panc-1 cells down-regulated the expression of CDK1/CDC2, cyclin B1, and cyclin D1 and up-regulated the expression of p21, and p27.
CONCLUSIONS: Overexpression of KLF8 may contribute to the progression of pancreatic cancer, and downregulation of KLF8 expression by lentivirus-delivered shRNA is a novel therapeutic approach for PC.

Wang M, Zhou A, An T, et al.
N-Hydroxyphthalimide exhibits antitumor activity by suppressing mTOR signaling pathway in BT-20 and LoVo cells.
J Exp Clin Cancer Res. 2016; 35:41 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: N-Hydroxyphthalimide (NHPI), an important chemical raw material, was found to have potent and selective anti-proliferative effect on human breast carcinoma BT-20 cells, human colon adenocarcinoma LoVo and HT-29 cells during our screening for anticancer compounds. The purpose of this study is to assess the antitumor efficacy of NHPI in vitro and in vivo and to explore the underlying antitumor mechanism.
METHODS: Cell cytotoxicity of NHPI was evaluated using MTS assay and cell morphological analysis. After NHPI treatment, cell cycle, apoptosis and mitochondrial membrane potential were analyzed using flow cytometer. The subcellular localization of eukaryotic initiation factor 4E (eIF4E) was analyzed by immunofluorescence assay. The antitumor efficacy of NHPI in vivo was tested in BT-20 xenografts. The underlying antitumor mechanisms of NHPI in vitro and in vivo were investigated with western blot analysis in NHPI-treated cancer cells and tumor tissues. Statistical significance was determined using Student's t-test.
RESULTS: In vitro, NHPI selectively inhibited the proliferation and induced G2/M phase arrest in BT-20 and LoVo cells, which was attributed to the inhibition of cyclin B1 and cdc2 expressions. Furthermore, NHPI induced apoptosis via mitochondrial pathway. Of note, NHPI effectively inhibited mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTOR complex 2 (mTORC2) signaling, and overcame the feedback activation of Akt and extracellular signal-regulated kinase (ERK) caused by mTORC1 inhibition in BT-20 and LoVo cells. In vivo, NHPI inhibited tumor growth and suppressed mTORC1 and mTORC2 signaling in BT-20 xenografts with no obvious toxicity.
CONCLUSIONS: We found for the first time that NHPI displayed antitumor activity which is associated with the inhibition of mTOR signaling pathway. Our findings suggest that NHPI may be developed as a promising candidate for cancer therapeutics by targeting mTOR signaling pathway and as such warrants further exploration.

Yu R, Yu BX, Chen JF, et al.
Anti-tumor effects of Atractylenolide I on bladder cancer cells.
J Exp Clin Cancer Res. 2016; 35:40 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Atractylenolide I (ATR-1), an active component of Rhizoma Atractylodis Macrocephalae, possesses cytotoxicity against various carcinomas. However, little is known about the effects of ATR-1on bladder cancer. In the present study, the anti-tumor activity of ATR-1 was examined on bladder cancer cells both in vivo and in vitro.
METHODS: MTT assay was used to assess the cytotoxic effect of ATR-1. Cell cycle distribution and apoptosis levels were evaluated using flow cytometry. Western blotting assay was applied to measure the levels of proteins associated with the apoptotic pathway, cell cycle progression and PI3K/Akt/mTOR signaling pathway. Tumor models in nude mice were induced by injection of T-24 and 253J human bladder cancer cells.
RESULTS: ATR-1 inhibited bladder cancer cell proliferation, arrested cell cycle in G2/M phase through up-regulation of p21 and down-regulation of cyclin B1, CDK1 and Cdc25c. Meanwhile, ATR-1 also triggered cellular apoptosis depending on the activation of mitochondrial apoptotic pathway. Mechanism investigation indicated that ATR-1 exerts its anti-tumor effect also relies on the inhibition of PI3K/Akt/mTOR signaling pathway. Finally, mice studies showed that ATR-1 blocked the T-24 or 253J-induced xenograft tumor growth without noticeable toxicity.
CONCLUSIONS: ATR-1 may be served as a potential therapeutic agent for the treatment of bladder cancer.

Bednarek K, Kiwerska K, Szaumkessel M, et al.
Recurrent CDK1 overexpression in laryngeal squamous cell carcinoma.
Tumour Biol. 2016; 37(8):11115-26 [PubMed] Free Access to Full Article Related Publications
In this study, we analyzed the expression profile of four genes (CCNA2, CCNB1, CCNB2, and CDK1) in laryngeal squamous cell carcinoma (LSCC) cell lines and tumor samples. With the application of microarray platform, we have shown the overexpression of these genes in all analyzed LSCC samples in comparison to non-cancer controls from head and neck region. We have selected CDK1 for further analysis, due to its leading role in cell cycle regulation. It is a member of the Ser/Thr protein kinase family of proven oncogenic properties. The results obtained for CDK1 were further confirmed with the application of reverse transcription quantitative polymerase chain reaction (RT-qPCR) technique, Western blot, and immunohistochemistry (IHC). The observed upregulation of CDK1 in laryngeal squamous cell carcinoma has encouraged us to analyze for genetic mechanisms that can be responsible this phenomenon. Therefore, with the application of array-CGH, sequencing analysis and two methods for epigenetic regulation analysis (DNA methylation and miRNA expression), we tried to identify such potential mechanisms. Our attempts to identify the molecular mechanisms responsible for observed changes failed as we did not observe significant alterations neither in the DNA sequence nor in the gene copy number that could underline CDK1 upregulation. Similarly, the pyrosequencing and miRNA expression analyses did not reveal any differences in methylation level and miRNA expression, respectively; thus, these mechanisms probably do not contribute to elevation of CDK1 expression in LSCC. However, our results suggest that alteration of CDK1 expression on both mRNA and protein level probably appears on the very early step of carcinogenesis.

Chang Q, Chandrashekhar M, Ketela T, et al.
Cytokinetic effects of Wee1 disruption in pancreatic cancer.
Cell Cycle. 2016; 15(4):593-604 [PubMed] Free Access to Full Article Related Publications
The Wee1 kinase, which is activated in response to DNA damage, regulates exit from G2 through inhibitory phosphorylation of Cdk1/Cdc2, and is an attractive drug target. However, recent work has highlighted effects of Cdk2 phosphorylation by Wee1 on movement through S-phase, suggesting the potential to sensitize to S-phase specific agents by Wee1 inhibitors. In this paper we applied multiparametric flow cytometry to patient-derived pancreatic cancer xenograft tumor cells to study the cell cycle perturbations of Wee1 disruption via the small molecule inhibitor MK-1775, and genetic knockdown. We find that in vitro treatment with MK-1775, and to a lesser degree, Wee1 RNA transcript knockdown, results in the striking appearance of S-phase cells prematurely entering into mitosis. This effect was not seen in vivo in any of the models tested. Here, although we noted an increase of S-phase cells expressing the damage response marker γH2AX, treatment with MK-1775 did not significantly sensitize cells to the cytidine analog gemcitabine. Treatment with MK-1775 did result in a transient but large increase in cells expressing the mitotic marker phosphorylated H3S10 that reached a peak 4 hours after treatment. This suggests a role for Wee1 regulating the progression of genomically unstable cancer cells through G2 in the absence of extrinsically-applied DNA damage. A single dose of 8Gy ionizing radiation resulted in the time-dependent accumulation of Cyclin A2 positive/phosphorylated H3S10 negative cells at the 4N position, which was abrogated by treatment with MK-1775. Consistent with these findings, a genome-scale pooled RNA interference screen revealed that toxic doses of MK-1775 are suppressed by CDK2 or Cyclin A2 knockdown. These findings support G2 exit as the more significant effect of Wee1 inhibition in pancreatic cancers.

Costa-Cabral S, Brough R, Konde A, et al.
CDK1 Is a Synthetic Lethal Target for KRAS Mutant Tumours.
PLoS One. 2016; 11(2):e0149099 [PubMed] Free Access to Full Article Related Publications
Activating KRAS mutations are found in approximately 20% of human cancers but no RAS-directed therapies are currently available. Here we describe a novel, robust, KRAS synthetic lethal interaction with the cyclin dependent kinase, CDK1. This was discovered using parallel siRNA screens in KRAS mutant and wild type colorectal isogenic tumour cells and subsequently validated in a genetically diverse panel of 26 colorectal and pancreatic tumour cell models. This established that the KRAS/CDK1 synthetic lethality applies in tumour cells with either amino acid position 12 (p.G12V, pG12D, p.G12S) or amino acid position 13 (p.G13D) KRAS mutations and can also be replicated in vivo in a xenograft model using a small molecule CDK1 inhibitor. Mechanistically, CDK1 inhibition caused a reduction in the S-phase fraction of KRAS mutant cells, an effect also characterised by modulation of Rb, a master control of the G1/S checkpoint. Taken together, these observations suggest that the KRAS/CDK1 interaction is a robust synthetic lethal effect worthy of further investigation.

Tseng TH, Chien MH, Lin WL, et al.
Inhibition of MDA-MB-231 breast cancer cell proliferation and tumor growth by apigenin through induction of G2/M arrest and histone H3 acetylation-mediated p21(WAF1/CIP1) expression.
Environ Toxicol. 2017; 32(2):434-444 [PubMed] Related Publications
Apigenin (4',5,7-trihydroxyflavone), a flavonoid commonly found in fruits and vegetables, has anticancer properties in various malignant cancer cells. However, the molecular basis of the anticancer effect remains to be elucidated. In this study, we investigated the cellular mechanisms underlying the induction of cell cycle arrest by apigenin. Our results showed that apigenin at the nonapoptotic induction concentration inhibited cell proliferation and induced cell cycle arrest at the G2/M phase in the MDA-MB-231 breast cancer cell line. Immunoblot analysis indicated that apigenin suppressed the expression of cyclin A, cyclin B, and cyclin-dependent kinase-1 (CDK1), which control the G2-to-M phase transition in the cell cycle. In addition, apigenin upregulated p21(WAF1/CIP1) and increased the interaction of p21(WAF1/CIP1) with proliferating cell nuclear antigen (PCNA), which inhibits cell cycle progression. Furthermore, apigenin significantly inhibited histone deacetylase (HDAC) activity and induced histone H3 acetylation. The subsequent chromatin immunoprecipitation (ChIP) assay indicated that apigenin increased acetylation of histone H3 in the p21(WAF1/CIP1) promoter region, resulting in the increase of p21(WAF1/CIP1) transcription. In a tumor xenograft model, apigenin effectively delayed tumor growth. In these apigenin-treated tumors, we also observed reductions in the levels of cyclin A and cyclin B and increases in the levels of p21(WAF1/CIP1) and acetylated histone H3. These findings demonstrate for the first time that apigenin can be used in breast cancer prevention and treatment through epigenetic regulation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 434-444, 2017.

Zhao Y, Hou J, Mi P, et al.
Exo70 is transcriptionally up-regulated by hepatic nuclear factor 4α and contributes to cell cycle control in hepatoma cells.
Oncotarget. 2016; 7(8):9150-62 [PubMed] Free Access to Full Article Related Publications
Exo70, a member of the exocyst complex, is involved in cell exocytosis, migration, invasion and autophagy. However, the expression regulation and function of Exo70 in hepatocellular carcinoma are still poorly understood. In this study, we found Exo70 expression in human hepatoma cells was greatly reduced after knocking down hepatic nuclear factor 4α (HNF4α), the most important and abundant transcription factor in liver. This regulation occurred at the transcriptional level but not post-translational level. HNF4α transactivated Exo70 promoter through directly binding to the HNF4α-response element in this promoter. Cell cycle analysis further revealed that down-regulation of HNF4α and Exo70 was essential to berberine-stimulated G2/M cell cycle arrest in hepatoma cells. Moreover, knocking down either Exo70 or HNF4α induced G2/M phase arrest of hepatoma cells. Exo70 acted downstream of HNF4α to stimulate G2/M transition via increasing Cdc2 expression. Together, our results identify Exo70 as a novel transcriptional target of HNF4α to promote cell cycle progression in hepatoma, thus provide a basis for the development of therapeutic strategies for hepatocellular carcinoma.

Chen J, Wei Y, Feng Q, et al.
Ribosomal protein S15A promotes malignant transformation and predicts poor outcome in colorectal cancer through misregulation of p53 signaling pathway.
Int J Oncol. 2016; 48(4):1628-38 [PubMed] Related Publications
Ribosomal protein S15A (RPS15A), which has been identified as a highly conserved 40S ribosomal protein, is essential for cell survival and proliferation. The present study evaluated the functional role of RPS15A in colorectal cancer (CRC), and our investigation found that RPS15A was highly expressed in a cohort of human CRC. High RPS15A expression was associated with older age (P=0.035), not receiving preoperative neoadjuvant treatment (P=0.048), higher primary pN stage (P=0.007) and slightly more synchronous distant metastases (P=0.058). The Cox univariate and multivariate hazard regression analysis revealed that higher expression of RPS15A led to a reduction of overall survival rate in CRC, indicating that enhanced RPS15A expression functions as an independent risk factor for the prognosis of CRC patients (P<0.001). Cell based analysis showed that RPS15A was widely expressed in human CRC cell lines. Knockdown of RPS15A significantly suppressed cell proliferation and colony formation in HCT116 and DLD-1 cells, and induced cell cycle arrest at G0/G1 phase. Genechip analysis suggested that knockdown of RPS15A might affect the p53 signaling pathway. Further study indicated that RPS15A knockdown upregulated p53 and p21 expression whereas downregulated CDK1 expression. In summary, the present study identified RPS15A as a novel univariate prognostic factor predicting a poor outcome in CRC patients. The RPS15A overexpression induced by malignant transformation of CRC might function through the p53 signaling pathway.

Chen X, Luo J, Meng L, et al.
Dracorhodin perchlorate induces the apoptosis of glioma cells.
Oncol Rep. 2016; 35(4):2364-72 [PubMed] Related Publications
Dracorhodin perchlorate (Dp), a synthetic analogue of the antimicrobial anthocyanin red pigment, has recently been shown to induce apoptotic cell death in various types of cancer cells. Yet, the inhibitory effect of Dp on human glioma cells remains uninvestigated. Therefore, in the present study, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to detect cell viability and cell cycle progression in glioma U87MG and T98G cells, respectively. Annexin V-FITC/propidium iodide double staining and JC-1 staining were separately applied to determine cellular apoptosis and mitochondrial membrane potential damage in the cells. The expression levels of associated proteins involved in cell cycle progression and apoptosis were measured by western blotting. The activities of caspase‑9/-3 were determined by Caspase-Glo-9/3 assay. The results indicated that Dp treatment significantly inhibited cell proliferation in a dose- and time-dependent manner, and blocked cell cycle progression at the G1/S phase in the U87MG and T98G cells via the upregulation of p53 and p21 protein expression, and simultaneous downregulation of Cdc25A, Cdc2 and P-Cdc2 protein expression. Additionally, Dp treatment led to the loss of cellular mitochondrial membrane potential, and the release of cytochrome c, and strongly induced the occurence of apoptosis. Increased expression levels of Bim and Bax protein and the downregulated expression of Bcl-2 protein were observed. Caspase-9/-3 were activated and their activities were elevated after Dp treatment. These findings indicate that Dp inhibits cell proliferation, induces cell cycle arrest and apoptosis in glioma cells, and is a possible candidate for glioma treatment.

Zhao S, Chen X, Wan M, et al.
Tectonic 1 Is a Key Regulator of Cell Proliferation in Pancreatic Cancer.
Cancer Biother Radiopharm. 2016; 31(1):7-13 [PubMed] Related Publications
Pancreatic cancer is notoriously becoming one of the most devastating human cancers leading to death. However, clinical challenges still remain in diagnosis and treatment of this ticklish cancer. In the present study, the authors identified a new gene, Tectonic 1 (TCTN1), as a key regulator of cell proliferation in pancreatic cancer. Lentivirus-mediated short hairpin RNA (shRNA) was employed to knock down endogenous TCTN1 expression in PANC-1 pancreatic cancer cells. Knockdown of TCTN1 expression potently inhibited cell viability and proliferation, as determined by MTT and colony formation assays. Western blotting analysis also showed that knockdown of TCTN1 suppressed the expression of cdc2, while it induced that of p21 and p27. Flow cytometry analysis showed that depletion of TCTN1 in PANC-1 cells led to cell cycle arrest in the G2/M phase as well as apoptosis. Besides, depletion of TCTN1 led to the increase of Bax and cleavage of PARP-1, but the decrease of bcl2 by western blotting. The data indicate that TCTN1 is indispensable for pancreatic cancer cell proliferation, which provides a novel alternative to targeted therapy of pancreatic cancer and deserves further investigation.

Zhang X, Chen X, Liu J, et al.
Knockdown of WISP1 inhibit proliferation and induce apoptosis in ALL Jurkat cells.
Int J Clin Exp Pathol. 2015; 8(11):15489-96 [PubMed] Free Access to Full Article Related Publications
WISP1, a Wnt-induced secreted protein, has been found to have anticancer activity. ALL is a leading cause of death. Here we investigate the WISP1 effects on ALL Jurkat cells. Cell viability was assessed by CCK-8. Cell cycle and apoptosis were detected by flow cytometry. Mitochondrial membrane potential (MMP) was monitored using TMRM. Generation of reactive oxygen species (ROS) was quantified using DCFH-DA. Western blot was used to detect the expression of cell proliferation and apoptosis related genes. The results showed that knockdown of WISP1 significantly inhibited proliferation of Jurkat cells. Parallelly, cell cycle distribution was increased at G1 phase and apoptotic rate was induced after WISP1 knockdown. Furthermore, knockdown of WISP1 induced apoptosis of Jurkat cells was also associated with loss of MMP and generation of ROS. Western blot results showed that the protein expression p-AKT, PCNA, CDK1, P-ERK, CDK2, VEGF, VEGFR2 and Bcl2 were decreased, while the expression of Bax was up-regulated. In conclusion, WISP1 plays an important role in proliferation and apoptosis of Jurkat cells in mitochondria dependent pathway, the specific mechanisms need further study.

Wong SM, Liu FH, Lee YL, Huang HM
MPT0B169, a New Antitubulin Agent, Inhibits Bcr-Abl Expression and Induces Mitochondrion-Mediated Apoptosis in Nonresistant and Imatinib-Resistant Chronic Myeloid Leukemia Cells.
PLoS One. 2016; 11(1):e0148093 [PubMed] Free Access to Full Article Related Publications
Chronic myeloid leukemia (CML) is a clonal disorder of hematopoietic stem/progenitor cells that is caused by the Bcr-Abl oncoprotein. Clinical resistance to the Bcr-Abl inhibitor imatinib is a critical problem in treating CML. This study investigated the antitumor effect and mechanism of MPT0B169, a new antitubulin agent, in K562 CML cells and their derived imatinib-resistant cells, IMR2 and IMR3. IMR2 and IMR3 cells showed complete resistance to imatinib-induced growth inhibition and apoptosis. Resistance involved ERK1/2 overactivation and MDR1 overexpression. MPT0B169 inhibited the growth of K562, IMR2, and IMR3 cells in a dose- and time-dependent manner. MPT0B169 substantially inhibited the mRNA and protein levels of Bcr-Abl, followed by its downstream pathways including Akt, ERK1/2, and STAT3 in these cells. MPT0B169 treatment resulted in a decrease in the polymer form of tubulin according to Western blot analysis. It triggered cell cycle arrest at the G2/M phase before apoptosis, which was related to the upregulation of the mitotic marker MPM2 and the cyclin B1 level, and a change in the phosphorylation of Cdk1. MPT0B169 induced apoptosis in nonresistant and imatinib-resistant cells via a mitochondrion-mediated caspase pathway. Further study showed that the agent led to a decrease in the antiapoptotic proteins Bcl-2, Bcl-xL, and Mcl-1 and an increase in the apoptotic protein Bax. Taken together, our results suggest that MPT0B169 might be a promising agent for overcoming imatinib resistance in CML cells.

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