BACKGROUND:12-lipoxygenase(12-LOX) has been reported to be an important gene in cancer cell proliferation and survival,and tumor metastasis.However,its role in hepatocellular carcinoma(HCC) cells remains unknown.METHO...BACKGROUND:12-lipoxygenase(12-LOX) has been reported to be an important gene in cancer cell proliferation and survival,and tumor metastasis.However,its role in hepatocellular carcinoma(HCC) cells remains unknown.METHODS:Expression of 12-LOX was assessed in a diethylnitrosamine-induced rat HCC model,and in SMMC-7721,HepG2 and L-02 cells using immunohistochemical staining and reverse transcriptase-polymerase chain reaction(RT-PCR).GST-π and Ki-67 were determined in vivo by immunohistochemical staining.Apoptosis was evaluated by TUNEL assay.Cell viability and apoptosis were determined by MTT assay and flow cytometry,respectively.Apoptosis-related proteins in SMMC-7721 and HepG2 cells were detected by Western blotting.RESULTS:Immunohistochemical staining and RT-PCR showed that 12-LOX was over-expressed in rat HCC and two HCC cell lines,while the expression was inhibited by baicalein,a specific inhibitor of 12-LOX.Baicalein inhibited cell proliferation and induced apoptosis in rat HCC and both cell lines in a dose-and time-dependent manner.Our in vivo study demonstrated that baicalein also reduced neoplastic nodules.Mechanistically,baicalein reduced Bcl-2 protein expression coupled with a slight increase of the expression of Bax and activation of caspase-3.Furthermore,baicalein inhibited the activation of ERK-1/2(phosphorylated).Interestingly,the effects of baicalein were reversed by 12(S)-HETE,a metabolite of 12-LOX.CONCLUSIONS:Inhibition of 12-LOX leads to reduced numbers of HCC cells,partially caused by increased apoptosis.12-LOX may be a potential molecular target for HCC prevention and treatment.展开更多
BACKGROUND Acute pancreatitis(AP),the initially triggered inflammatory process in the pancreas,can be life-threatening.It has been reported that 15-lipoxygenase may promote the removal of damaged intracellular compone...BACKGROUND Acute pancreatitis(AP),the initially triggered inflammatory process in the pancreas,can be life-threatening.It has been reported that 15-lipoxygenase may promote the removal of damaged intracellular components,maintain intracellular homeostasis,and promote apoptosis by upregulating the activity of caspases.Despite an increased understanding of the lipoxygenase pathway in inflammation and immune diseases,the role of the Alox15 gene product in modulating the inflammatory changes during AP is not well defined.AIM To investigate the effect of Alox15 expression in cerulein-induced AP in rats.METHODS Model rats were transfected with Alox15 by injecting a recombinant lentivirus vector encoding Alox15 into the left gastric artery before inducing AP.The expression of Alox15 was then assessed at the mRNA and protein levels.RESULTS Our in vivo results showed that serum amylase activity and pancreatic tissue water content were significantly reduced in Alox15-transfected rats.Further,the mRNA expression levels of tumor necrosis factor alpha,interleukin(IL)-1β,IL-6,and monocyte chemoattractant protein-1,as well as the protein expression of nuclear factor kappa B in pancreatic tissue were reduced.Additionally,we observed an upregulation of cleaved caspase-3 that implies an induction of apoptosis in pancreatic cells.The transfection of Alox15 resulted in a lower number of autophagic vacuoles in AP.CONCLUSION Our findings demonstrate a regulatory role of Alox15 in apoptosis and autophagy,making it a potential therapeutic target for AP.展开更多
基金supported by grants from the National Natural Science Foundation of China(81000998)the Natural Science Foundation of Hubei Province,China(2007ABA248)the Foundation of the Ministry of Education of China for New Teachers(20090141120003)
文摘BACKGROUND:12-lipoxygenase(12-LOX) has been reported to be an important gene in cancer cell proliferation and survival,and tumor metastasis.However,its role in hepatocellular carcinoma(HCC) cells remains unknown.METHODS:Expression of 12-LOX was assessed in a diethylnitrosamine-induced rat HCC model,and in SMMC-7721,HepG2 and L-02 cells using immunohistochemical staining and reverse transcriptase-polymerase chain reaction(RT-PCR).GST-π and Ki-67 were determined in vivo by immunohistochemical staining.Apoptosis was evaluated by TUNEL assay.Cell viability and apoptosis were determined by MTT assay and flow cytometry,respectively.Apoptosis-related proteins in SMMC-7721 and HepG2 cells were detected by Western blotting.RESULTS:Immunohistochemical staining and RT-PCR showed that 12-LOX was over-expressed in rat HCC and two HCC cell lines,while the expression was inhibited by baicalein,a specific inhibitor of 12-LOX.Baicalein inhibited cell proliferation and induced apoptosis in rat HCC and both cell lines in a dose-and time-dependent manner.Our in vivo study demonstrated that baicalein also reduced neoplastic nodules.Mechanistically,baicalein reduced Bcl-2 protein expression coupled with a slight increase of the expression of Bax and activation of caspase-3.Furthermore,baicalein inhibited the activation of ERK-1/2(phosphorylated).Interestingly,the effects of baicalein were reversed by 12(S)-HETE,a metabolite of 12-LOX.CONCLUSIONS:Inhibition of 12-LOX leads to reduced numbers of HCC cells,partially caused by increased apoptosis.12-LOX may be a potential molecular target for HCC prevention and treatment.
基金National Health Commission Research Fund,No.WKJ-ZJ-2342National Natural Science Foundation of China,No.81900583Science and Technology Plan Project of Wenzhou,No.Y20180103.
文摘BACKGROUND Acute pancreatitis(AP),the initially triggered inflammatory process in the pancreas,can be life-threatening.It has been reported that 15-lipoxygenase may promote the removal of damaged intracellular components,maintain intracellular homeostasis,and promote apoptosis by upregulating the activity of caspases.Despite an increased understanding of the lipoxygenase pathway in inflammation and immune diseases,the role of the Alox15 gene product in modulating the inflammatory changes during AP is not well defined.AIM To investigate the effect of Alox15 expression in cerulein-induced AP in rats.METHODS Model rats were transfected with Alox15 by injecting a recombinant lentivirus vector encoding Alox15 into the left gastric artery before inducing AP.The expression of Alox15 was then assessed at the mRNA and protein levels.RESULTS Our in vivo results showed that serum amylase activity and pancreatic tissue water content were significantly reduced in Alox15-transfected rats.Further,the mRNA expression levels of tumor necrosis factor alpha,interleukin(IL)-1β,IL-6,and monocyte chemoattractant protein-1,as well as the protein expression of nuclear factor kappa B in pancreatic tissue were reduced.Additionally,we observed an upregulation of cleaved caspase-3 that implies an induction of apoptosis in pancreatic cells.The transfection of Alox15 resulted in a lower number of autophagic vacuoles in AP.CONCLUSION Our findings demonstrate a regulatory role of Alox15 in apoptosis and autophagy,making it a potential therapeutic target for AP.
