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Objective To explore the role and mechanism of HMGB1 in the fatty acid metabolism reprogramming and mitochondrial fusion/fission of hypoxic and nutrient-poor pancreatic cancer cells. Methods The correlation between the expression level of HMGB1 in pancreatic cancer tissue and the survival rate of pancreatic cancer patients were analyzed by GEPIA database. CCK-8 assay was used to measure cell proliferation rate, and scratch test and Transwell chamber method were carried out to detect the effects of endogenous HMGB1 on the invasion and migration abilities of human pancreatic cancer cell line Patu8988 after hypoxic and nutrient-poor treatment. Laser confocal microscope was used to observe the changes of mitochondrial morphology of Patu8988 cells. Western blot was used to detect the expression levels of mitochondrial fusion/fission and de novo fatty acid synthesis-related proteins. Results GEPIA database analysis results showed that HMGB1 was highly expressed in pancreatic cancer tissues (P < 0.01), and the expression level was negatively correlated with the survival time of pancreatic cancer patients (P=0.00097). Knockdown of HMGB1 expression could inhibit the proliferation, invasion and migration abilities of Patu8988 cells under hypoxic and nutrient-poor conditions. However, mitochondrial fission in patu8988 cells was increased. Knockdown of HMGB1 in Patu8988 cells increased the expression of fission-related protein FIS1 while decreased the expression of p-DRP1(Ser637) and fusion-related protein MFN1 and MFN2 in hypoxic and nutrient-poor environment; ACLY, p-ACLY and FASN protein expression levels were down-regulated. Conclusion Endogenous HMGB1 can promote the fusion and inhibit the fission of mitochondria in hypoxic and nutrient-poor Patu8988 cells, maintain mitochondrial morphology and function, and thereby up-regulate ACLY protein expression and phosphorylation level, promote FA synthesis, and maintain the proliferation, invasion and migration abilities of pancreatic cancer cells.
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Objective To investigate the effect of intrathecal gastrodin on skin cancer pain in mice.Methods Thirty-two female Balb/c mice,aged 8 weeks,weighing 20-25 g,were randomly divided into 4 groups (n=8 each) using a random number table:sham operation group (group S),skin cancer pain group (group SCP),gastrodin group (group G),and artificial cerebrospinal fluid (ACSF) control group (group ASCF).Skin cancer pain was produced by injecting phosphate buffer solution 20 μl containing about 2 ×105 4T1 breast cancer cells into the plantar surface of the left hindpaw.At 14th day after inoculation of cancer cells,ASCF 5 μl was injected intrathecally in S and ACSF groups,and gastrodin 150 μg/kg (5 μl) was injected intrathecally in group G.Before inoculation,at 30 min before intrathecal injection,and at 15,30,60,90,120 and 150 min after intrathecal injection,the thermal paw withdrawal latency (TWL) was measured.The expression of acid-sensing ion channel (ASIC)-3 mRNA in the spinal dorsal horn was detected using the real-time reverse transcriptase polymerase chain reaction after the last measurement of the pain threshold.Results Compared with group S,the TWL was significantly decreased at each time point before and after intrathecal injection in SCP,ACSF and G groups,and the expression of ASIC-3 mRNA in the spinal dorsal horn was significantly down-regulated in group G (P＜0.05).Compared with group SCP,the TWL was significantly increased at each time point after intrathecal injection,and the expression of ASIC-3 mRNA in the spinal dorsal horn was significantly down-regulated in group G (P＜0.05),and no significant change was found in the parameters mentioned above in group ACSF (P＞0.05).Conclusion Intrathecal gastrodin can reduce skin cancer pain and down-regulate ASIC-3 expression in the spinal dorsal horn which is helpful in maintaining the analgesic effect in mice.
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Objective To study the effects and preliminary mechanism of Stattic (Y705),an inhibitor of the signal transducer and activator of transcription-3 (STAT3),on the growth,migration,invasion and radiosensitization of hepatocellular carcinoma cell line Bel-7402.Methods Bel-7402 cells were divided to four groups:blank control group,Stattic treatment group,radiation group,and Stattic combined with radiation group.The cell growth and proliferation were detected by using CCK8 kit.The influence of Stattic on radiation sensitivity of Bel-7402 cells was determined by clone formation assay.The cell migration and invasion ability were tested by scratch migration assay and transwell assay,respectively.The protein expressions of STAT3,p-STAT3,Bax,Bcl-2,Caspase-3,Cleaved Caspase-3,MMP-2 and MMP-9 were quantified by Western blotting assay.Results Stattic significantly inhibited the growth of human hepatocellular carcinoma Bel-7402 cells with a dose-depended manner.The IC50 of Stattic after 48 h treatment was 2.5 μ mol/L.When 1.0 μmol/L Stattic was combined with 8 Gy X-rays,there was a synergistic effect in inhibition of cell proliferation with a inhibition rate of (15.00 ± 1.87) ％ (F =63.30,P ＜ 0.05).Scratch migration assay and transwell invasion assay showed that the migration and invasion abilities of the combination group were significantly reduced.In addition,compared with the radiation group,the SF2,D0and Dq values obtained from survival curve were decreased (t =4.20,6.92,9.32,P ＜0.05),the protein expressions of p-STAT3,MMP-2,MMP-9 were reduced (t =5.32,6.02,13.26,P ＜0.05),the protein expressions of Bax and Cleaved Caspase-3 were increased in the combination group(t =-7.82,-14.09,P ＜ 0.05),meanwhile the protein expressions of Bcl-2 was decreased (t =18.43,P ＜ 0.05).When the concentration of Stattic was 0.5 μmol/L,the radiation sensitization ratio at 2 Gy (SERSF2) was 1.22.Conclusions By inhibiting the activation of the p-STAT3 in Bel-7402 cells,stattic could induce cell apoptosis and increase the radiosensitivity,down regulate MMP-2 and MMP-9 and thereby reduce the invasion and migration of tumor cells.
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Objective To explore the expression of urothelial carcinoma-associated 1 ( UCA1 ) in pancreatic cancer cell lines and its influence on the invasion and metastasis of the pancreatic cancer cells .Methods The expression of UCA1 in pancreatic cancer tissues and paired adjacent normal tissues ( 11 cases ) and 5 pancreatic cancer cell lines was analyzed by real-time PCR.The level of UCA1 in BxPC-3 was knocked down by small interfering RNA . The ability of invasion and migration in vitro of transfected BxPC-3 was detected by Transwell invasion assay and wound healing assay .The protein levels of MMP-2 and MMP-9 were measured by Western blot experiment .Results The expression level of UCA1 in pancreatic cancer tissues was higher than that in paired adjacent normal tissues , and UCA1 differentially expressed in 5 pancreatic cancer cell lines .Down-regulation of UCA1 by siRNA suppressed the expression of MMP-2 and MMP-9 in BxPC3, and dramatically impaired the ability of invasion and migration of BxPC-3.Conclusions UCA1 is over-expressed in pancreatic cancer , and down-regulation of UCA1 attenuates the capacity of invasion and metastasis in vitro of BxPC-3 by decreasing MMP-2 and MMP-9.
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Objective To observe the effects of ischemic preconditioning of hindlimb (HIP) on the expressions of heat shock protein70 (HSP70) in spinal cord of rats after spinal cord injury (SCI). MethodSprague Dawleys rats were randomly( random number) divided into three groups (20 rats in each group).In sham injury group, rats received laminectomy without SCI; while in the SCI group, rats received traumatic SCI. In HIP group, rats received HIP 8 h before SCI. The SCI animal models were made by using modified Allen's weight-drop device (50 g·cm) on L3-L4 vertebrae. HIP was induced by compressing the two lower limbs of rats alternately with a tourniquet for three cycles of ten-minute ischaemia followed by ten-minute reperfusion. Rats were sacrificed 24 h and 48 h after injury separately. The protein and mRNA of HSP70 of involved spinal cord segments were determined by using RT-PCR, hybridization in situ and immunohistochemistry. Results There was weak expression of HSP70 mRNA in rats of sham injury group, and sporadic positive cells in spinal tissue were found by using immunohistochemistry. The expressions of HSP70 mRNA 24 h and48 hours after SCI in HIP group[(22.18±3.69) and (14.15 ±4.18)] were higher than those in SCI group[(13.97±4.46) and ( 8.73 ± 3.55 )], and the differences were statistically significant (F=16.06, P = 0.005 and F = 7.43, P = 0. 028). The protein levels of HSP70 24 h and 48 hours after SCI in HIP group [(16.71±4.02) and (9.85±2.20)] were higher than those in SCI group [( 14.85 ± 3.73)and (8.78 ±2.05)], and the differences were statistically significant (F =90. 13, P =0.032 and F=34.70, P = 0. 036). Conclusions HIP can increase the transcription and expression of HSP70 in spinal cord of rats following SCI and may have the protective effects on neural tissue.
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Objective To investigate the effects of the fibrin scaffold on the differentiation and the proliferation of neural stem cells and astrocytes. Methods Neural stem cells and the gliocytes derived from spinal cord were cultured in vitro respectively. The purified neural stem cells or gliocytes were seeded separately onto the fibrin scaffolds as experimental group and the glass slides modified with poly-L-lysine(PLL)as control group. At different time in culture the neural stem cells were immunofluorescence stained with antibodies against the marker of neurons I.e. Neurofilament(NF).The length of NF-positive neuritis was masured and the average value was calculated in the culture well (n=4). The gliocytes were immunofluorescence stained with antibodies against the marker of astrocytes I.e. Glial fibrillary acidic protein (GFAP ). The total number of the cells and the GFAP-positive cells were counted from 5 different fields of vision in the culture well (n=4), then the average ratio of GFAP-positive cells was calculated. The differentiation of neural stem cells, the extension of neurites and the proliferation of astrocytes on the fibrin scaffolds were compared with those on the slides. The protein of GFAP was detected by Western blotting to analyse the mature degree of astrocytes. All above experiments were repeated 3 times respectively. Results Immunofluorescence staining showed that the NF-positive neurites in the fibrin scaffold group were longer than those in the control group, whereas GFAP-positive cells were fewer than those in the control group. The expression of GFAP in the cells on the scaffold was lower than that in the control group.Conclusion The fibrin scaffold could promote differentiation of the neural stem cells to neurons and extension of the neurites. Meanwhile, the scaffold could inhibit proliferation and mature of the astrocytes.