This study aimed to observe the effect of terpinen-4-ol(T4O) on the proliferation of vascular smooth muscle cells(VSMCs) exposed to high glucose(HG) and reveal the mechanism via the Krüppel-like factor 4(KLF4)/nuclear factor kappaB(NF-κB) signaling pathway. The VSMCs were first incubated with T4O for 2 h and then cultured with HG for 48 h to establish the model of inflammatory injury. The proliferation, cell cycle, and migration rate of VSMCs were examined by MTT method, flow cytometry, and wound healing assay, respectively. The content of inflammatory cytokines including interleukin(IL)-6 and tumor necrosis factor-alpha(TNF-α) in the supernatant of VSMCs was measured by enzyme-linked immunosorbent assay(ELISA). Western blot was employed to determine the protein levels of proliferating cell nuclear antigen(PCNA), Cyclin D1, KLF4, NF-κB p-p65/NF-κB p65, IL-1β, and IL-18. The KLF4 expression in VSMCs was silenced by the siRNA technology, and then the effects of T4O on the cell cycle and protein expression of the HG-induced VSMCs were observed. The results showed that different doses of T4O inhibited the HG-induced proliferation and migration of VSMCs, increased the percentage of cells in G_1 phase, and decreased the percentage of cells in S phase, and down-regulated the protein levels of PCNA and Cyclin D1. In addition, T4O reduced the HG-induced secretion and release of the inflammatory cytokines IL-6 and TNF-α and down-regulated the expression of KLF4, NF-κB p-p65/NF-κB p65, IL-1β, and IL-18. Compared with si-NC+HG, siKLF4+HG increased the percentage of cells in G_1 phase, decreased the percentage of cells in S phase, down-regulated the expression of PCNA, Cyclin D1, and KLF4, and inhibited the activation of NF-κB signaling pathway. Notably, the combination of silencing KLF4 with T4O treatment further promoted the changes in the above indicators. The results indicate that T4O may inhibit the HG-induced proliferation and migration of VSMCs by down-regulating the level of KLF4 and inhibiting the activation of NF-κB signaling pathway.
NF-kappa B/metabolism* ; Interleukin-18/metabolism* ; Proliferating Cell Nuclear Antigen/genetics* ; Cyclin D1/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Muscle, Smooth, Vascular ; Cell Proliferation ; Signal Transduction ; Cytokines/metabolism* ; Glucose/metabolism*

<b>OBJECTIVEb>To explore the feasibility and value of detecting CyclinD1 and BCL-2 in patients with B-cell lymphoma by using flow cytometry.

<b>METHODSb>Fifty-three patients with lymphoma were selected, and 50 healthy persons in the same period were selected as control. The expression levels of CyclinD1 and BCL-2 in patients with various subtypes of lymphoma were detected by using flow cytometry (FCM).

<b>RESULTSb>When the dilution time was 1 min and the dilution proportion was 1:20, the cell morphology was the best complete, at the 4 min the cell morphology was best status. The mean fluorescence intensity of CyclinD1 and BCL-2 between persons of control group and patients with B-cell lymphoma showed significant difference, the CyclinD1 level (1.824 ± 0.315) and BCL-2 levels (4.257 ± 0.528) of patients with B-cell lymphoma were obviously higher than the CyclinD1 level (0.634 ± 0.153) and BCL-2 level (1.926 ± 0.328) of persons in control group, the CyclinD1 and BCL-2 expression levels of patients with HL were significantly lower than CyclinD1 and BCL-2 levels of patients with NHL (P < 0.01). After treatment, the expression levels of CyclinD1 and BCL-2 in patients with B lymphoma were significantly lower than these befor treatment.

<b>CONCLUSIONb>Using the method of flow cytometry for detecting CyclinD1 and BCL-2 expression levels in lymphoma cells of patients is feasible, and it can be applied clinically to evaluate the treatment efficacy.

Case-Control Studies ; Cyclin D1 ; metabolism ; Flow Cytometry ; Humans ; Lymphoma, B-Cell ; diagnosis ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism

<b>BACKGROUNDb>Retinal degenerative diseases are the leading causes of blindness in developed world. Retinal progenitor cells (RPCs) play a key role in retina restoration. Triamcinolone acetonide (TA) is widely used for the treatment of retinal degenerative diseases. In this study, we investigated the role of TA on RPCs in hypoxia condition.

<b>METHODSb>RPCs were primary cultured and identified by immunofluorescence staining. Cells were cultured under normoxia, hypoxia 6 h, and hypoxia 6 h with TA treatment conditions. For the TA treatment groups, after being cultured under hypoxia condition for 6 h, RPCs were treated with different concentrations of TA for 48-72 h. Cell viability was measured by cell counting kit-8 (CCK-8) assay. Cell cycle was detected by flow cytometry. Western blotting was employed to examine the expression of cyclin D1, Akt, p-Akt, nuclear factor (NF)-κB p65, and caspase-3.

<b>RESULTSb>CCK-8 assays indicated that the viability of RPCs treated with 0.01 mg/ml TA in hypoxia group was improved after 48 h, comparing with control group (P < 0.05). After 72 h, the cell viability was enhanced in both 0.01 mg/ml and 0.02 mg/ml TA groups compared with control group (all P < 0.05). Flow cytometry revealed that there were more cells in S-phase in hypoxia 6 h group than in normoxia control group (P < 0.05). RPCs in S and G2/M phases decreased in groups given TA, comparing with other groups (all P < 0.05). There was no significant difference in the total Akt protein expression among different groups, whereas upregulation of p-Akt and NF-κB p65 protein expression and downregulation of caspase-3 and cyclin D1 protein expression were observed in 0.01 mg/ml TA group, comparing with hypoxia 6 h group and control group (all P < 0.05).

<b>CONCLUSIONb>Low-dose TA has anti-apoptosis effect on RPCs while it has no stimulatory effect on cell proliferation.

Animals ; Apoptosis ; drug effects ; physiology ; Caspase 3 ; metabolism ; Cell Cycle ; drug effects ; physiology ; Cell Hypoxia ; drug effects ; physiology ; Cell Proliferation ; drug effects ; physiology ; Cell Survival ; drug effects ; physiology ; Cells, Cultured ; Cyclin D1 ; metabolism ; NF-kappa B ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Retina ; cytology ; Stem Cells ; cytology ; drug effects ; Triamcinolone Acetonide ; pharmacology

<b>OBJECTIVEb>To investigate the effects of bromodomain-containing protein 4 (BRD4) inhibitor GSK525762A on the proliferation and apoptosis of primary common B-cell acute lymphoblastic leukemia (common B-ALL) cells from adult patients, then to further explore the possible mechanisms.

<b>METHODSb>Purified leukemia cells from 14 common B-ALL adult patients (4 Ph⁺ and 10 Ph⁻ cases) were obtained by flow cytometry sorting, and maintained in a mimic bone marrow microenvironment culture system for short-term culture. Leukemia cells were treated with various concentrations of GSK525762A. The inhibitory effects of BRD4 inhibitor on common B-ALL leukemia cells were measured by CCK-8 assay and the apoptosis of those cells was determined by AnnexinⅤ/7-AAD staining using flow cytometry. The transcripts of c-MYC, CDK6 and Bcl-2 were detected by quantitative RT-PCR, and the expression of c-MYC, CDK6 and Bcl-2 proteins were detected via Western blot.

<b>RESULTSb>GSK525762A could inhibit the proliferation of leukemia cells from all 14 common B-ALL patients in a dose-dependent manner, the median value of IC50 was 256.25 (90.64-1 378.39)nmol/L. GSK525762A could promote cells apoptosis of B-ALL leukemia cells in a dose-dependent manner, the median apoptosis rates respectively were 45.17%(9.38%-70.91%), 66.02% (24.36%-96.34%) and 89.29% (39.29%-99.37%) after treated by 500, 1 000 and 2 500 nmol/L GSK525762A. GSK525762A has a similar effect on Ph⁺ ALL and Ph⁻ B-ALL, but the effect of proliferation inhibition and apoptosis enhancement on Ph+ B-ALL is weaker than that on Ph⁻ B-ALL. Compared with vehicle control group, the levels of c-MYC, Bcl-2 and CDK6 transcripts in leukemic cells were reduced after treatment for 24 h and 48 h by 1 000 nmol/L GSK525762A, and there are no significant differences in the downregulation of c-MYC and CDK6 mRNA between Ph⁺ and Ph⁻ B-ALL; however, the inhibitory effect on Bcl-2 transcription was weaker in Ph⁺ B-ALL cells than that in Ph⁻ B-ALL cells. Moreover, c-MYC, Bcl-2 and CDK6 protein levels decreased in GSK525762A treated group.

<b>CONCLUSIONb>GSK525762A could strongly inhibit the proliferation of common B-ALL and trigger apoptosis; meanwhile it has certain effects against Ph⁺ ALL in vitro. The effect may be achieved by down-regulation of c-MYC, CDK6 and Bcl-2 expression.

Apoptosis ; Benzodiazepines ; pharmacology ; Cell Line, Tumor ; drug effects ; Cyclin-Dependent Kinase 6 ; metabolism ; Down-Regulation ; Flow Cytometry ; Humans ; Nuclear Proteins ; antagonists & inhibitors ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Transcription Factors ; antagonists & inhibitors

<b>OBJECTIVEb>To study expression of CD68, cyclin D1 protein and rearrangement of bcl-6 gene impact on the prognosis of diffuse large B-cell lymphoma (DLBCL).

<b>METHODSb>Gets paraffin samples of the 105 cases DLBCL with the detailed follow-up information, and were studied by using immunohistochemical EnVision method for CD3, CD10, CD20, CD68, cyclin D1, bcl-6, MUM 1, SOX-11 immunolabeling. The DLBCL were classified into germinal center B cell-like (GCB) subtypes and non-germinal center B cell-like (non-GCB) subtypes according to Hans'algorithm. Application of fluorescence in situ hybridization (FISH) technique to detect the bcl-6 gene rearrangement. The relationship between CD68, cyclin D1 protein, the bcl-6 gene and the curative effect of chemotherapy and survival was analyzed using statistical software. Respectively by GCB type, non-GCB type immune phenotype and CHOP, R-CHOP chemotherapy group, compare the curative effects.

<b>RESULTSb>105 patients had GCB 19 cases (18.1%), non-GCB 86 cases (81.9%), CD68 expression was 18 cases (17.1%), cyclin D1 high expression 36 cases (34.3%), bcl-6 gene rearrangement in 21 cases (21.9%), there is no correlation among the three (P > 0.05). One-way analysis of variance showed that age ≤ 60 years, clinical stage I-II, IPI score 0 to 2 points, LDH (U/L) < 245 IU/L,GCB subtypes, R-CHOP therapy, the prognosis of patients with better (P < 0.05), But gender, primary site no correlation with prognosis (P > 0.05). CD68, cyclin D1 high expression, bcl-6 rearrangement had poor prognosis (P < 0.05). Stratification analysis results show GCB-type or non-GCB type with high expression of CD68 contrast alloimmune phenotype groups had a poor prognosis, non-GCB type with high expression of cyclin D1 and rearrangement of bcl-6 gene had a poor prognosis (P < 0.001, P = 0.02). Treatment scheme of layered display, the CHOP treatment, significantly correlated with overall survival with high expression of CD68, cyclin D1 (P < 0.05), the R-CHOP treatment, there was no statistically significant difference between CD68, cyclin D1 high expression and overall survival (P = 0.428 and 0.168). Multivariate COX model analysis showed that high expression of CD68 (P = 0.026), high expression of cyclin D1 (P = 0.003) and high levels of LDH (P = 0.005) were adverse prognostic factors independent.

<b>CONCLUSIONSb>high expression of CD68, cyclin D1 and rearrangement of bcl-6 gene suggests poor prognosis, CD68, cyclin D1 protein and bcl-6 gene can be used as a prognostic indicator in patients with DLBCL.

Antibodies, Monoclonal, Murine-Derived ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; B-Lymphocytes ; classification ; Cyclin D1 ; metabolism ; Cyclophosphamide ; DNA-Binding Proteins ; genetics ; Doxorubicin ; Gene Rearrangement ; Germinal Center ; cytology ; Humans ; In Situ Hybridization, Fluorescence ; Lymphoma, Large B-Cell, Diffuse ; diagnosis ; Prednisone ; Prognosis ; Proto-Oncogene Proteins c-bcl-6 ; Vincristine

<b>OBJECTIVEb>To characterize the role of tumor necrosis factor-α (TNF-α) and NF-κB play a role in macrophage-like THP-1 cells promoting coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells (BEAS-2B).

<b>METHODSb>From passage 10, CTPE-induced BEAS-2B cells cocultured with THP-1 cells were treated with NF-κB inhibitor-Pyrrolidine dithiocarbamate (PDTC) every 3 passages and TNF-α antibody every passage. Alterations of cell cycle, karyotype and colony formation in soft agar of BEAS-2B cells at passages 20, indicative of tumorigenicity, were determined, respectively. In addition, mRNA and protein levels of TNF receptor associated factor2 (TRAF2) and Cyclin D1 in BEAS-2B cells were measured with Real Time-PCR and Western blot, respectively.

<b>RESULTSb>The percentages of S-phase BEAS-2B cells at passage 20 in PDTC group and TNF-α antibody group were (33.97±2.16)% and (34.29±2.04)% respectively, which were less than that in Co-culture+CTPE group of 20th passage [(44.46±0.83)%], P < 0.05; The number of cells with aneuploidy in 100 cells in 20th passage PDTC group and TNF-α antibody group were 40 and 37, and there were significantly different when comparing to that of 20th passage Co-culture+CTPE group (75); The number of colony formation and the rate of colony formation of BEAS-2B cells in soft agar at passage 20 in PDTC group were (15.17±2.48) and (1.51‰±0.25‰), (13.33±2.58)and (1.33‰±0.26‰) in TNF-α antibody group, which were less that those in 20th passage Co-culture+CTPE group [(172.33±12.09) and (17.23‰±1.20‰)], P < 0.05; at the same time, the mRNA and protein levels of TRAF2 and Cyclin D1 in BEAS-2B cells were decreased after PDTC and TNF-α antibody treatment.

<b>CONCLUSIONb>TNF-α and NF-κB could play an important role in THP-1 cells promoting coal tar pitch extract-induced tumorigenic transformation of BEAS-2B cells by influencing the expression of TRAF2 and Cyclin D1.

Bronchi ; cytology ; Cell Line ; Cell Transformation, Neoplastic ; drug effects ; Coal Tar ; toxicity ; Cyclin D1 ; metabolism ; Epithelial Cells ; cytology ; Humans ; Macrophages ; cytology ; NF-kappa B ; metabolism ; TNF Receptor-Associated Factor 2 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

<b>OBJECTIVEb>To investigate the effects of E2F-1 gene silencing on multidrug resistance of human gastric cancer SGC7901/DDP cells and its possible mechanisms.

<b>METHODSb>Gastric cancer SGC7901/DDP cells were seeded in 6 well plates and divided into three groups: the experimental group, blank control and the negative control groups. For the experimental group, the SGC7901/DDP cells were transfected with recombinant lentivirus vector (Lv-shRNA-E2F-1), while the negative control with an control lentiviral vector (Lv-shRNA-NC) and the blank control with no treatment. The E2F-1 protein level was analyzed by Western blot. MTT assay was used to detect the half maximal inhibitory concentration (IC50) of three chemotherapy drugs including adriamycin, 5-fluorouracil (5-Fu) and cisplatine (DDP) of the three cell groups. Flow cytometry (FCM) was used to detect the pump-out rate of adriamycin and apoptosis rate of the three cell groups. Semi-quantitative RT-PCR and Western blot were also used to detect the protein and mRNA levels of multidrug resistance-associated genes (MDR1, MRP) and apoptosis-related genes (c-Myc, Skp2, cyclinD1).

<b>RESULTSb>The expression of E2F-1 protein in the experimental group was significantly lower than that in the negative control and blank control groups (0.794 ± 0.033 vs. 1.487 ± 0.082 vs. 1.511 ± 0.084, P < 0.01). The IC50 of the three chemotherapy drugs (adriamycin, 5-Fu and cisplatine) in the experimental group was significantly lower than that of the negative control and blank control groups, respectively (P < 0.01). Compared with the negative control and blank control groups, the pump-out rate of adriamycin of the experimental group was significantly declined [(0.16 ± 0.01)% vs. (0.37 ± 0.01)% vs. (0.35 ± 0.02)%, P < 0.01]. However, the apoptosis rate of the experimental group was significantly higher than that of the negative control and blank control groups [(33.82 ± 1.26)% vs. (17.34 ± 0.81)% vs. (13.16 ± 1.06)%, P < 0.01]. The results of RT-PCR and Western blot assays showed that mRNA and protein expressions of five genes (MDR1, MRP, CyclinD1, c-Myc, Skp2) in the experimental group were significantly lower than that in the negative control and blank control groups, respectively (P < 0.01).

<b>CONCLUSIONSb>E2F-1 gene silencing enhances the chemosensitivity of gastric cancer SGC7901/DDP cells to the chemotherapeutic drugs, directly or indirectly downregulated the expression of MDR1 and MRP, and finally reverses the multidrug resistance of the gastric cancer cells. The mechanism may be associated with the suppression of cyclinD1, c-Myc and Skp2.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Antibiotics, Antineoplastic ; pharmacology ; Antimetabolites, Antineoplastic ; pharmacology ; Antineoplastic Agents ; pharmacology ; Apoptosis ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Cyclin D1 ; genetics ; metabolism ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; E2F1 Transcription Factor ; genetics ; metabolism ; Fluorouracil ; pharmacology ; Gene Silencing ; Genetic Vectors ; Humans ; Lentivirus ; genetics ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; S-Phase Kinase-Associated Proteins ; genetics ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; Transfection

BACKGROUND/AIMS: 5'-Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that monitors intracellular AMP/adenosine triphosphate (ATP) ratios and is a key regulator of the proliferation and survival of diverse malignant cell types. In the present study, we investigated the effect of activating AMPK by 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR) in thyroid cancer cells. METHODS: We used FRO thyroid cancer cells harboring the BRAF(V600E) mutation to examine the effect of AICAR on cell proliferation and cell survival. We also evaluated the involvement of mitogen-activated protein kinase (MAPK) pathways in this effect. RESULTS: We found that AICAR treatment promoted AMPK activation and suppressed cell proliferation and survival by inducing p21 accumulation and activating caspase-3. AICAR significantly induced activation of p38 MAPK, and pretreatment with SB203580, a specific inhibitor of the p38 MAPK pathway, partially but significantly rescued cell survival. Furthermore, small interfering RNA targeting AMPK-alpha1 abolished AICAR-induced activation of p38 MAPK, p21 accumulation, and activation of caspase-3. CONCLUSIONS: Our findings demonstrate that AMPK activation using AICAR inhibited cell proliferation and survival by activating p38 MAPK and proapoptotic molecules in FRO thyroid cancer cells. These results suggest that the AMPK and p38 MAPK signaling pathways may be useful therapeutic targets to treat thyroid cancer.
AMP-Activated Protein Kinases/genetics/metabolism ; Aminoimidazole Carboxamide/*analogs & derivatives/pharmacology ; Antineoplastic Agents/*pharmacology ; Caspase 3/metabolism ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Cyclin-Dependent Kinase Inhibitor p21/metabolism ; Dose-Response Relationship, Drug ; Enzyme Activation ; Enzyme Activators/pharmacology ; Humans ; Mutation ; Protein Kinase Inhibitors/pharmacology ; Proto-Oncogene Proteins B-raf/genetics ; RNA Interference ; Ribonucleotides/*pharmacology ; Signal Transduction/*drug effects ; Thyroid Neoplasms/*enzymology/genetics/pathology ; Time Factors ; Transfection ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/*metabolism

Ataxia telangiectasia mutated (ATM) kinase plays an essential role in the maintenance of genomic stability. ATM-deficient (ATM(-/-)) mice exhibit hematopoietic stem cell (HSC) dysfunction and a high incidence of lymphoma. Gadd45a controls cell cycle arrest, apoptosis and DNA repair, and is involved in the ATM-p53 mediated DNA damage response. However, the role of Gadd45a in regulating the functionality of ATM(-/-) HSCs is unknown. Here we report that Gadd45a deletion did not rescue the defects of T-cells and B-cells development in ATM(-/-) mice. Instead, ATM and Gadd45a double knockout (ATM(-/-) Gadd45a(-/-)) HSCs exhibited an aggravated defect in long-term self-renewal capacity compared to ATM(-/-) HSCs in HSC transplantation experiments. Further experiments revealed that the aggravated defect of ATM(-/-) Gadd45a(-/-) HSCs was due to a reduction of cell proliferation, associated with an accumulation of DNA damage and subsequent activation of DNA damage response including an up-regulation of p53-p21 signaling pathway. Additionally, ATM(-/-) Gadd45a(-/-) mice showed an increased incidence of hematopoietic malignancies, as well as an increased rate of metastasis than ATM(-/-) mice. In conclusion, Gadd45a deletion aggravated the DNA damage accumulation, which subsequently resulted in a further impaired self-renewal capacity and an increased malignant transformation in ATM(-/-) HSCs.
Animals ; Ataxia Telangiectasia Mutated Proteins ; genetics ; B-Lymphocytes ; pathology ; Cell Cycle Proteins ; genetics ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; DNA Damage ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; metabolism ; pathology ; Leukemia ; genetics ; pathology ; Lymphoma ; genetics ; pathology ; Mice, Knockout ; Neoplasm Metastasis ; Nuclear Proteins ; genetics ; T-Lymphocytes ; pathology ; Tumor Suppressor Protein p53 ; metabolism

<b>OBJECTIVEb>To investigate the effect of celecoxib in enhancing the chemosensitivity of oral cancer cells and the correlation of this effect with cell cycle arrest.

<b>METHODSb>KB/VCR cell line was treated with celecoxib (10, 20, 40, and 80 µmol/L) and/or VCR (0.375, 0.75, 1.5, and 3 µmol/L), and the growth inhibition rates of KB/VCR cells were assessed with MTT assay. Flow cytometry was employed to analyze the distribution of cell cycle. Western blotting was performed to detect the expression of P-glycoprotein (P-gp) and the cell cycle related proteins Cyclin D1 and p21(WAF1/CIP1).

<b>RESULTSb>Low concentrations of celecoxib (<20 µmol/L) produced no obvious effect on the proliferation of the cells. But at 10 µmol/L, celecoxib significantly enhanced the toxicity of VCR in a time-dependent manner, and the combined treatments for 24, 48, and 72 h caused growth inhibition rates of (37.53∓2.05)%, (46.67∓3.17)% and (54.02∓1.53)%, respectively, significantly higher than those following treatments with celecoxib or VCR alone (P<0.01). Compared with the cells treated with VCR alone , the cells with combined treatments showed a significantly increased cell percentage in G0/G1 phase [(56.08∓0.46)%] with decrease percentages in S phase [(22.83∓0.20)%] and G2/M phase [(21.09%∓0.66)%]. The combined treatment also significantly down-regulated cyclin D1, up-regulated p21(WAF1/CIP1), and reduced P-gp expressions in the cells.

<b>CONCLUSIONSb>Celecoxib enhances the chemosensitivity of KB/VCR cells by down-regulating P-gp expression, which is partially mediated by modification of cyclin D1 and p21(WAF1/CIP1) to result in cell cycle arrest.

ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Celecoxib ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Drug Resistance, Neoplasm ; drug effects ; Humans ; KB Cells ; Mouth Neoplasms ; drug therapy ; metabolism ; Pyrazoles ; pharmacology ; Sulfonamides ; pharmacology