Analysis of cancer stem cells in breast cancer cell line MCF-7/ADM

AIM: This study is designed to demonstrate the drug resistance breast cancer cell line MCF-7/ADM has a higher proportion of cancer stem cells than its original parent cell line MCF-7 in vitro.METHODS: Firstly,the drug resistance of MCF-7/ADM was estimated by MTT method,and then higher proportion of cancer stem cells in MCF-7/ADM than that in MCF-7 was demonstrated by three aspects: side population analysis,sphere culture and cell surface markers of breast cancer stem cells.RESULTS: The drug resistance index of MCF-7/ADM compared to MCF-7 was 37.1.The proportion of side population in MCF-7/ADM and MCF-7 was 9.60%±0.66% versus 0.39%±0.11%;The proportion of sphere-initiating cells in MCF-7/ADM and MCF-7 was 10.27%±0.64% versus 1.03%±0.15%,and the proportion of CD+44CD-24 cells in these two cell lines was 64.87%±3.87% versus 3.70%±0.53%,all are statistically significant.CONCLUSION: ADM resistance breast cancer cell line MCF-7/ADM has a higher proportion of cancer stem cells than that in its original cell line MCF-7.     

Inhibitory effects of recombinant human Mullerian inhibiting substance on cell proliferation in two human ovarian carcinoma cell lines

AIM: To investigate the inhibitory effects of recombinant human Mullerian inhibiting substance on cell proliferation in human ovarian carcinoma cells (OVCAR8 and SKOV3 cell lines). METHODS: The expression of MISIIR protein and the localization of MISIIR protein were analyzed by Western blotting and confocal spectral microscopy, respectively. Cell apoptosis and cell cycle were detected by flow cytometry (FCM). Cell viability was determined via MTT method. Clone formation test was used to detect oncogenicity in vitro.RESULTS: The MISIIR protein expression in OVCAR8 cells but not in SKOV3 cells was observed. MISIIR expression was seen on the OVCAR8 cell surface and in the cytoplasm with both antibodies. After treated with rhMIS for 48 h, the cell viability was significantly decreased in OVCAR8 cells. rhMIS inhibited the oncogenicity of OVCAR8 cells greatly. The cell apoptosis of OVCAR8 cell exposed to 10 mg/L rhMIS was (31.3±2.1)%, and OVCAR8 cells in the G1 phase were increased by (70.4±3.0)%. Compared to SKOV3 cells the differences were significant (P<0.01). CONCLUSION: Recombinant human Mullerian inhibiting substance suppresses the growth of MISIIR-positive ovarian cancer cells by inducing apoptosis and cell cycle arrest. We predict that rhMIS might be a new target to treat human ovarian malignancies.     

Ovarian carcinoma cells inhibit ζ chain expression and the secretion of Tc1/Tc2 type cytokines in CD8+ T cells

AIM: To investigate the effect of ovarian carcinoma cells on ζ chain expression and the secretion of Tc1/Tc2 type cytokine in CD8+ T cells, and its role in the ovarian carcinoma induced immunosuppression.METHODS: The supernatants of human ovarian carcinoma cell lines of OVCAR3, CAOV3 and SKOV3 and RPMI-1640 were added into CD8+ T cells (groups I, II, III, and control), which were isolated from the peripheral venous blood of healthy persons. The expression of ζ chain was analyzed by Western blotting. Thiazolyl blue(MTT) method was used to detect the effects of those cell line supernatants on the growth of CD8+ T cells. The secretion of the Tc1 type cytokine interferon (IFN)-γ mRNA and the Tc2 type cytokine interferon (IL)-10 mRNA were detected by RT-PCR. RESULTS: The expression of ζ chain was significantly lower in groups I, II, and III in comparison with that in control group. The absorbance at the wavelength 570 nm of CD8+ T cells culture in the group I, II, and III was all significantly lower than that in the control group. The IFN-γ expression was significantly lower in groups I, II, and III in comparison with that in control group, while the expression of IL-10 was significantly higher. CONCLUSION: Ovarian carcinoma may suppress CD8+ T cell proliferation and secretion of the Tc1/Tc2 type cytokine through inhibition of ζ chain, which may play an important role in the ovarian carcinoma induced immunosuppression.     

Sensitivity of different human colorectal tumor cell lines to commonly used chemotherapeutic drugs in vitro

AIM: To observe the antitumor effect of 5 commonly used chemotherapeutic drugs on 11 human colorectal cancer cell lines in vitro. METHODS: CCK-8 method was used to determine the growth inhibitory effects of 5 antitumor drugs, which were expressed as the half growth inhibitory concentration (IC50) and sensitivity index IC50/PPC (peak plasma concentration) on 11 human colorectal cancer cell lines. The expression variations of heat-shock protein 27 (HSP27) and HSP70 at protein levels in human colorectal tumor cell lines treated with different chemotherapeutic drugs were observed by Western blotting. RESULTS: All the 11 colorectal cancer cell lines were sensitive to 5-fluorouracil (5-FU) and oxaliplatin (OHP) without drug resistant. Five colorectal cancer cell lines were sensitive to mitomycin (MMC), while the other 6 cell lines were moderately sensitive. Ten colorectal cancer cell lines except SW1116 were sensitive to docetaxel (DXL), while SW1116 cells were resistant to DXL. Nine colorectal cancer cell lines except LS174T and SW1116 were moderately sensitive to irinotecan (IFL), and SW1116 cells were also resistant to IFL, while LS174T cells were sensitive to IFL. After treated with the antitumor drugs, HSP27 was up-regulated in HCT116 cells and SW480 cells, while the expression of HSP70 didnt change. CONCLUSION: LS174T cells are multidrug-sensitive, while SW1116 cells are multidrug-resistant. 5-FU and OHP are the wide-spectrum anti-colorectal cancer drugs. Determining the sensitivity to chemotherapeutic drugs and the expression level of HSP27 can improve the accuracy in drug selection.     

Effects of different chemotherapeutic agents on reversing the acquired resistance to TRAIL gene in DLD1 colon cancer cells

AIM:To evaluate effects of different chemotherapeutic agents on reversing the acquired resistance to TRAIL gene and clarify the involved mechanisms in DLD1-TRAIL/R colon cancer cells. METHODS:Human colon cancer cell line DLD1-TRAIL/R cells that were resistant to TRAIL-expressing adenovector (Ad/gTRAIL) were treated with Ad/gTRAIL combined with different chemotherapeutic agents. Then, the cell viability was measured by MTT method, and apoptotic signaling conditions, including activation of caspase-3 and caspase-8, expression of Bax and Bcl-XL, were measured by Western blotting analysis. RESULTS:In vitro data showed that several chemotherapeutic agents, including 5-fluorouracil (5-FU) and mitomycin c (MMC), overcome the acquired resistance to TRAIL gene in DLD1-TRAIL/R colon cancer cells. The combination of Ad/gTRAIL and 5-FU effectively suppressed tumor growth in vivo in subcutaneous tumors established from DLD1-TRAIL/R cells. Further data showed that treatment with the combination of Ad/gTRAIL and 5-FU or MMC led to enhance the activation of caspase-3. Moreover, MMC but not 5-FU induced overexpression of Bax gene that was sufficient to overcome the resistance to TRAIL gene in DLD1-TRAIL/R cells. CONCLUSION:Chemotherapeutic agents, such as 5-FU and MMC, overcome the acquired resistance to TRAIL gene in DLD1-TRAIL/R cells. The candidate mechanisms for MMC but not 5-FU to overcome this resistance might involve the induction of over-expressed Bax protein in DLD1-TRAIL/R cells.     

Expression of drug resistance related proteins in osteosarcoma and soft tissue sarcoma and its correlations with chemotherapy resistance

AIM: To explore the expression of four kinds of drug resistance related protein: P-glycoprotein (P-gp), glutathione-S-transferases-π (GST-π), lung resistance protein (LRP), multidrug resistance related protein (MRP) in osteosarcoma cell lines Saos2 and U2OS, and in osteosarcoma and soft tissue sarcoma tissues from 34 patients and their correlations with chemotherapy resistance.METHODS: The expression of protein was detected by flow cytometry (FCM).Chemotherapy resistance was analyzed by MTT assay.RESULTS: Expression of drug resistance related protein was lower in Saos2 cell line than that in U2OS cells.Chemotherapy sensitivity on adriamycin (ADM), cisplatinum (DDP), fluorouracilum (5-Fu), mitomycin (MMC), dacarbazine (DTIC), vincristine (VCR) was higher in Saos2 than those in U2OS cells.After the two cell lines were treated respectively with 1/5 50% inhibitory concentration (IC50) doses of ADM and DDP, the expression increasing range of GST-π was 33%-43%.The nonsensitive rate on ADM, DDP, 5-Fu, MMC, DTIC, VCR, methotrexate (MTX) in 34 patients were 41.18％, 17.65％, 47.06％, 50.00％, 76.47％, 61.76％ and 52.94％, respectively.The expression of P-gp, GST-π, LRP, MRP were 1.54, 2.58, 1.91 and 1.86, respectively.The correlation analysis showed that the expression of P-gp had positive correlation with resistance on ADM (r=0.485, P<0.01), the expression of GST-π had correlations with resistance on ADM, DDP, 5-Fu and MMC.The r value was 0.402, 0.458, 0.364 and 0.500,respectively.The corresponding value of P was <0.05, <0.01, <0.05 and <0.01,respectively.The observed expression of resistance related proteins was not significant difference between different gender, different age, different pathological type and different tumor size in osteosarcoma and soft tissue sarcoma patients (P>0.05).The expression of GST-π was increased dramatically in patients receiving chemotherapy preoperatively.The preoperative level of GST-π was higher in recurrent patients by follow-up survey than that in patients without recurrence (P<0.05).CONCLUSIONS: Individual difference was obvious in chemotherapy sensitivity and expression of resistance related proteins in different patients.Chemotherapy induced the upregulation of GST-π expression.Primary high expression of GST-π was the main mechanism of resistance in osteosarcoma and soft tissue sarcoma patients, and related with prognosis.     

Changes and clinical significance of serum protein factors in patients with polycystic ovary syndrome

AIM:To study the changes and clinical significance of serum protein factors in the patients with polycystic ovary syndrome (PCOS). METHODS:The relative expression levels of 174 ser protein factors in 5 PCOS patients and 5 control women were assayed simultaneously by Antibody Protein Array 2000,in which 2 factors were chosen to test and reconfirm the results by ELISA in 30 cases of PCOS patients and 30 cases of controls. RESULTS:Among 174 serum protein factors, the factors that elevated in PCOS patients were angiogenin, EGF, IGFBP-1, IGFBP-4, IL-7, MIP-1-delta, PARC, PDGF-BB, Acrp30, EGFR, ICAM-1, sTNF-RI, TIMP-2, TRAIL-R3, E-selectin, IL-1RII, IL-5Ra, LAP, L-selectin, M-CSFR, PDGF-AA, prolactin and VEGFR2, while the factors that decreased in PCOS patients were GRO, IL-8 and Siglec-5. Nine factors were increased 3 times more than the controls(IL-1R-II, prolactin, IL-7, IGFBP-1, IL-5Ra, IGFBP-4, VEGFR2, ICAM-1 and MIP-1-delta). PDGF-BB and Acrp30 were tested by ELISA in 60 samples and there were significant differences between the 2 groups. CONCLUSION: The changes of the protein factors in serum might play an important role in the pathogenesis of PCOS.     

Subacute inflammatory reaction in follicular fluid of Chinese PCOS patients

AIM: To retrospectively analyze the lipid metabolism disturbance and subacute inflammation within the microenvironment of follicular fluid between Chinese polycystic ovarian syndrome(PCOS) patients and the controls.METHODS: Serum lipid indexes, steroid hormone levels, and inflammatory cell counts were analyzed. The inflammatory cytokine and apolipoprotein levels were detected in the serum and follicular fluid. The mRNA expression of apolipoproteins and cytokines in the granulose cells was determined by real-time PCR.RESULTS: PCOS patients showed typical obesity accompanied with hyperlipidemia and hyperandrogenemia. Significantly elevated inflammatory cell number and cytokine levels were detected in both serum and follicular fluid. The mRNA expression levels of the inflammatory cytokines and apolipoproteins in the granulose cells from the PCOS patients were higher than those from the controls.CONCLUSION: Elevated apolipoproteins reflect systematic hyperlipidemia in the follicular fluid. Serum lipids and cytokines penetrate follicle-serum barrier and get into follicle fluid. Meanwhile, increased intake of apolipoproteins or elevated synthesis of cytokines(IL-1, IL-6 and TNF-α) by granulose cells could also be crucial to stabilize microenvironment of follicular fluid. Oocyte and subsequent embryos are sensitive to the originaal follicular environment. The lipid metabolism disturbance, inflammatory cell infiltration and hyperandrogenemia may possibly disturb oocyte developmental potential.     

Relationship between invasion of tumor-associated macrophages and phenotype and immune efficacy of tumor-infiltrating lymphocytes in advanced ovarian carcinoma

AIM:To explore the relationship between the invasion of tumor-associated macrophages(TAM) and the phenotype and immune efficacy of tumor-infiltrating lymphocytes(TIL) in advanced ovarian carcinoma. METHODS:Immunohistochemical analysis of TAM density in 175 cases of poorly-differentiated ovarian cancer tissue biopsy was performed. The cases were divided into TAM high-density(TAM^High) group and TAM low-density(TAM^Low) group according to the median of TAM density. The control group included 32 cases of benign ovarian lesions. The changes of CD8⁺ and CD25⁺ phenotypes of TIL were detected by flow cytometry analysis. TIL in the 2 groups were cultured in vitro and the conditioned-medium was collected for detecting the expression of IL-2, IL-10, TGF-β and IFN-γ by ELISA. RESULTS:The average TAM infiltration density was 62.8/high-power field(HP, ×400) in 175 cases of poorly-differentiated ovarian carcinoma, and the median was 53.3/HP. TAM^High group was 87 cases and TAM^Low group was 88 cases. A significant difference between malignant ovarian carcinoma group and control group(10.5/HP) was observed. The mean expression of CD8⁺ TIL in TAM^High group was 24%, and CD8⁺ TIL in TAM^Low group was 52%(P<0.05). The mean expression of CD25⁺ TIL in TAM^High was 48%, and CD25⁺ TIL in TAM^Low was 25%(P<0.05). The average infiltration density of CD8⁺ and CD25⁺ TIL in control group was 7%. The average infiltration density of CD8⁺ and CD25⁺ TIL in TAM^High and TAM^Low groups was significantly higher than that in control group(P<0.05). Compared with TAM^Low group, TIL destruction cytokines IL-2 and IFN-γ were significantly decreased in TAM^High group(P<0.05), while the inhibitory cytokines IL-10 and TGF-β were significantly increased(P<0.05). CONCLUSION:In high-density TAM infiltration of ovarian cancer tissues, CD25⁺ TIL type and inhibitory cytokines IL-10 and TGF-β increase, while CD8⁺ TIL type and destruction cytokines IL-2/IFN-γ decrease, suggesting that the high-density TAM has relationship with the phenotype and immune efficacy of TIL.     

Expression of cytokines and their receptors in leukemia cell lines and normal blood cells

AIM: To study the expression of cytokines and their receptors in leukemia cell lines and normal blood cells. METHODS: RT-PCR was used to detect expression of mRNA for cytokines in leukemia cell lines(HL-60,U937,K562,HEL,DAMI,MEG-01,HUT78 and CA) and normal blood cells, including CD34⁺ cells, megakaryocytes,platelets, peripheral mononucleates cells and granulocytes. RESULTS: ①CD34⁺ cells simultaneously expressed mRNA for IL-1(α,β),IL-3, IL-6 , G-CSF, GM-CSF and their receptors and SCFR,MPL as well. The granulocytes only expressed IL-6,IL-6R,G-CSFR,GM-CSF. Megakaryocytes and platelets only expressed IL-3R,IL-6,IL-6R,MPL.Interestingly, TGFβ₁ ,TNFα and their receptors sustained to express in normal cells.②Most leukemia cell lines were found to simultaneously express at least two or more stimulating cytokines and receptors ,while TGFβ 1 , TNFα and their receptors were expressed in all the leukemia cell lines we observed. CONCLUSIONS: ①Multi-autocrine loops exist in leukemia cells;②Imbalance of autocrine loops of positive and negative cytokines may be related to leukemia.     

Effect of gold nanoparticles on reversing adriamycin resistance of human hepatocellular carcinoma HepG2/ADM cells

AIM: To investigate whether gold nanoparticles (GNPs) reverses adriamycin (ADM), resistance of human hepatocellular carcinoma drug-resistant cell line HepG2/ADM and to explore the potential mechanism. METHODS: The sensitivities of HepG2 cells and HepG2/ADM cells to ADM were tested by MTT assay before and after GNPs pretreatment. The apoptotic rate was examined by flow cytometry. The concentration of ADM in HepG2/ADM or HepG2 cells was determined by ultraviolet-visible spectrophotometer. The content of glutathione (GSH) in HepG2/ADM or HepG2 cells by DTNB method. RESULTS: The half maximal inhibitory concentrations (IC₅₀) of ADM for HepG2/ADM cells were(29.46±1.73) mg/L and (15.18±0.85) mg/L before and after GNPs pretreatment,respectively. The IC₅₀ of ADM for HepG2 cells was (9.16±2.03) mg/L before pretreatment. The apoptotic rate in GNPs+ADM group was higher than that in ADM group (P<0.05). The concentration of ADM in HepG2/ADM group was lower than that in HepG2 group (P<0.01). After GNPs pretreatment, the concentration of ADM in HepG2/ADM cells was higher than that before pretreatment. The content of GSH in HepG2/ADM group was higher than that in HepG2 group (P<0.01). After GNPs pretreatment, the content of GSH in the HepG2/ADM cells was lower than that before pretreatment. CONCLUSION: Gold nanoparticles can reverse ADM resistance of human hepatocellular carcinoma drug-resistant cell line HepG2/ADM, reduce the content of GSH and increase the concentration of ADM in HepG2/ADM cells.     

Doxycycline upregulates autophagy to modulate the levels of inflammatory cytokines in LPS-stimulated THP-1 cells

AIM:To analyze the effect of autophagy on inflammatory response regulated by doxycycline in lipopolysaccharide (LPS)-stimulated THP-1 cells and to investigate its molecular mechanism. METHODS:A human monocyte/macrophage cell line THP-1 was stimulated with LPS to establish an cell model of inflammatory response, and the cells were treated with doxycycline. The cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8), in cell culture supernatant were measured by ELISA for evaluating the inflammatory levels. For determining the level of autophagy and its effect on inflammatory cell signaling pathways, the protein levels of LC3B, nuclear factor κB (NF-κB) and phosphorylated mammalian target of rapamycin (p-mTOR) were determined by Western blot. 3-Methyladenine (3-MA), an autophagy inhibitor, and rapamycin, an autophagy inducer, were used to study the effect of autophagy on inflammatory response regulated by doxycycline in LPS-stimulated THP-1 cells. RESULTS:The levels of TNF-α and IL-8 were increased rapidly and peaked at 12 h in LPS-stimulated THP-1 cells (P<0.05). Doxycycline significantly inhibited LPS-induced cytokine production in the THP-1 cells. Doxycycline up-regulated LPS-induced autophagy in THP-1 cells and doxycycline itself was an autophagy inducer. The protein levels of p-mTOR was up-regulated by LPS and down-regulated by doxycycline, suggesting that doxycycline induced autophagy via mTOR-dependent pathway while LPS through mTOR-independent pathway. Further studies showed that the combination of LPS, rapamycin and doxycycline inhibited the protein levels of NF-κB, and rapamycin increased the inhibitory effect of doxycycline on cytokine releases. Conversely, 3-MA, the autophagy inhibitor, attenuated the inhibitory effect of doxycycline on NF-κB and cytokine production. CONCLUSION:Autophagy is involved in the process of doxycycline modulating LPS-induced inflammatory response in the THP-1 cells.     

Up-regulation of microRNA-187* inhibits proliferation of human colon cancer cell line HCT116

AIM:To investigate the expression of microRNA-187* (miR-187*) in human colon cancer cell lines and normal colon tissues, and to determine the effects of miR-187* up-regulation on the proliferation and cell cycle of human colon cancer cell line HCT116. METHODS:The expression profiling of miRNAs in 3 colorectal adenocarcinoma samples and their matched normal tissue samples was performed using miRNA microarray chip. Total RNA was isolated from 8 colon cancer cell lines and 10 normal colon tissues. The miR-187* level was detected by Taqman real-time RT-PCR. B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1), the possible target of miR-187*, was also detected. Synthetic miR-187* mimics were transfected into HCT116 cell line by LipofectamineTM 2000. The mRNA expression of miR-187* and BMI-1 in HCT116 cell line was measured by real-time RT-PCR. Cell growth and cell cycle were assayed by MTS method and flow cytometry. RESULTS:miR-187* was found to be differentially expressed between colorectal adenocarcinoma and normal tissues. The expression of miR-187* in 8 colon cancer cell lines was down-regulated, while BMI-1 mRNA was up-regulated. Compared with blank control group, miR-187* expression was remarkably increased after transfection with miR-187* mimics, and ectopic expression of miR-187* significantly inhibited the mRNA expression of BMI-1. The cell growth was inhibited in miR-187* mimics group, and proliferating cell nuclear antigen (PCNA) mRNA expression was decreased. The cells at G2/M phase in miR-187* mimics group were significantly increased. CONCLUSION: miR-187* is down-regulated in human colon cancer cell lines. Up-regulation of miR-187* not only inhibits the proliferation but also influence the cell cycle of HCT116 cells, which might act as a tumor suppressor in colorectal cancer by inhibiting the expression of BMI-1.     

Establishment of arsenic trioxide-resistant K562/AS2 cell line and the mechanism of multidrug resistance

AIM:To establish a arsenic trioxide (As₂O₃ )-resistant leukemic cell line to explore the mechanism of resistance to As₂O₃, and the relationship between the resistant cell line and the multidrug resistance was also investigated. METHODS:The arsenic trioxide (As₂O₃ )-resistant leukemic cell line was established by exposing the cells to the increasing concentration of As₂O₃. MTT assay was used to detect the cytotoxicity. Cell cycle was detected by PI assay. Flow Cytometry was used to detect the P-glycoprotein on the surface of the cells, the intracellular concentration of DNR, and the immuetype of the cells. RESULTS:The cell doublings time and the cell cycle of the arsenic trioxide (As₂O₃ )-resistant leukemic cell line, K562/AS2, is similar to that of K562. The relative resistant fold of K562/AS2 to As₂O₃, DNR, VP16 and Ara-C was 7.4, 2.9, 3.8 and 1.1, respectively. The relative resistant fold of multidrug resistant cell line, K562/ A02, to As₂O₃, DNR, VP16 and Ara-C was 0.8、94、2.5 and 0.9, respectively. The fluorescence of the P-glycoprotein on the surface or of the DNR inside the cells detected was not significantly different between the K562 and the K562/AS2 cell lines. CONCLUSIONS:A cell line, K562/AS2, resistant to clinical achieving level (2 μmol/L) of As₂O₃ has been established. The relative resistant fold of K562/ AS2 to As₂O₃ is about 7.4 fold to the parent K562 line sensitive to As₂O₃. Partial resistance of K562/AS2 to DNR and VP16 is observed , the mechanism of which is unrelated to the P-gp, the expression product of multidrug resistance gene 1 (mdr1).     

Reverse effects of saikoside on multidrug resistance of human leukemic cell line K562/ADM in vitro

AIM: To study the reverse effects of saikoside (SS) on the multidrug resistance (MDR) of human leukemic cell line K562/ADM and to investigate the related mechanism. METHODS: K562 cells and K562/ADM cells in the culture were treated with SS at the concentrations of 1~100 mg/L. The inhibitory rate of the cell proliferation was measured by MTT assay. Non-cytotoxic dose of SS was determined. K562/ADM cells were treated with SS at non-cytotoxic doses of 1.25, 2.5 and 5.0 mg/L with different concentrations of adriamycin (ADM,0.05~100 mg/L). The 50% inhibitory concentration (IC₅₀) and the reversal index in all groups were determined. The cell morphology was observed after treated with SS+ADM. The effects of SS on ADM accumulation in K562/ADM cells, the cell cycle profile and apoptosis were examined by flow cytometry. RESULTS: The inhibitory rates were significantly increased in a dose-dependent manner when the cells were treated with different doses of SS (1~100 mg/L). The available reversal concentration of SS was 5.0 mg/L and the reversal index was 21.5 folds for K562/ADM cells. After treated with SS+ADM, the number of tumor cells was decreased and apoptotic cells were increased in a dose-response relationship. ADM accumulation in K562/ADM cells treated with SS was significantly higher than that in control cells (P<0.05). SS may significantly enhanced the apoptosis of K562/ADM cells treated with ADM (P<0.05). K562/ADM cells treated with SS were blocked in the stage of G₀/G₁. CONCLUSION: SS has effect on proliferation inhibition and MDR reversal in K562/ADM cell line. The reversal mechanisms of SS may be due to increasing the accumulation of chemo therapeutics in the cell, inducing the cell apoptosis and arresting the cells in G₀/G₁ phase.     

Effect of adriamycin combined with sensitized dendritic cells on cervical tumor-bearing mice

AIM：To explore the immunotherapeutic effect of adriamycin (ADM) combined with frozen-thawed antigen-sensitized dendritic cells (DCs) on cervical tumor-bearing mice. METHODS：The U14 cervical cancer model of Kunming mice was established by subcutaneous implantion of U14 cells in axillary fossa. DCs vaccine was prepared by U14 cervical cancer cell frozen-thawed antigen-sensitized mouse bone marrow-derived DCs. Mature phenotype of sensitized DCs was identified by flow cytometry. Tumor-bearing mice were randomly divided into 4 groups and treated for 3 cycles with PBS (control), DCs vaccine, ADM and ADM combined with DCs vaccine, respectively. The tumor volume was evaluated. The tumor weight and the levels of interleukin-2 (IL-2), IL-12 and interferon γ (IFN-γ) in the serum were determined by ELISA on the 21st day. RESULTS：Cancer cell frozen-thawed antigen-sensitized DCs had higher expression levels of CD11C, CD80 and CD86. The volume and weight of the tumor in ADM combined with DCs vaccine group were less than those in ADM group, DCs vaccine group and control group. The tumor inhibitory rate in combination group was higher than that in the other 3 groups. Compared with the other 3 groups, the serum levels of IL-2, IL-12 and IFN-γ in combination group significantly increased. CONCLUSION：ADM combined with tumor antigen-sensitized DCs vaccine can strengthen the animal antitumor immune response and effectively inhibit the growth of tumor in cervical tumor-bearing mice.     

Long non-coding RNA PVT1 regulates effect of miR-551 on migration and invasion abilities of ovarian cancer through Wnt signaling pathway

AIM: To investigate the expression of long non-coding RNA PVT1 in ovarian cancer and the role of PVT1 in migration and invasion abilities of ovarian cancer cells.METHODS: The expression of PVT1 in ovarian cancer tissue, normal ovarian tissue and different ovarian cancer cell lines was detected by qPCR. Transwell assay was used to detect the invasion ability of ovarian cancer cells after PVT1 silencing. The migration ability of the ovarian cancer cells after PVT1 silencing was detected by scratch test. The interaction between PVT1 and microRNA (miR)-551 was analyzed by dual-luciferase reporter assay. The effect of miR-551-inhibitor on the invasion and migration abilities of ovarian cancer cells after PVT1 silencing was detected by Transwell assay and scratch test. The expression of Wnt signaling pathway-related proteins was determined by Western blot after PVT1 silencing. The effects of PVT1 silencing on tumor weight and volume of ovarian cancer were examined by subcutaneous tumor transplantation in nude mice.RESULTS: The expression of PVT1 in ovarian cancer tissue was significantly higher than that in normal ovarian tissue (P<0.05). The expression level of PVT1 in ovarian cancer cell line ES-2 was the highest. PVT1 silencing inhibited the invasion and migration abilities of the ovarian cancer cells. After PVT1 silencing, miR-551-inhibitor promoted the invasion and migration abilities of the ovarian cancer cells. The expression of Wnt signaling pathway-related proteins was decreased after PVT1 silencing (P<0.05). Compared with negative control group, the tumor volume and weight in PVT1-siRNA group were significantly decreased (P<0.05).CONCLUSION: PVT1 plays an important role in the development of ovarian cancer. PVT1 regulates the invasion and migration abilities of ovarian cancer cells through Wnt signaling pathway.