Objective： To investigate the relation of X-linked inhibitor of apoptosis （XIAP） and second mitochondria-derived activator of caspase （Smac） signaling pathway to chemoresistance in human pancreatic cancer Panc-1 ...Objective： To investigate the relation of X-linked inhibitor of apoptosis （XIAP） and second mitochondria-derived activator of caspase （Smac） signaling pathway to chemoresistance in human pancreatic cancer Panc-1 and BXPC-3 cells. Methods： Apoptosis and the changes of XIAP expression in permeabilized cells induced by cisplatin and 5-fluorouracil （FU） were measured by flow cytometry. The cytosolic expression of XIAP, Smac and caspase-3 was detected by Western blot. A recombinant plasmid vector pEGFP-N1/Smac was constructed and transfected into of Pancol cells. The effect of cytosolic overexpression of Smac on apoptosis of Panc-1 cells was evaluated by flow cytometry. Results： Panc-1 was more resistant to cisplatin or 5-FU induced apoptosis than BXPC-3. Western blot revealed that chemoresistant Panc-1 highly expressed XIAP, and increased cytosolic expression of Smac might be responsible for the marked down-regulation of XIAP in chemo-sensitive BXPC-3 cells after exposure to cisplatin or 5-FU. Furthermore, cytosolic overexpression of Smac could significantly down-regulate the levels of XIAP and promote the activity of caspase-3, as well as sensitize Panc-1 cells to anticancer drug-induced apoptosis. Conclusion： Anticancer drug-induced apoptosis requires mitochondrial release of Smac and downregulation of XIAP, which may be an important determinant of chemo-sensitivity in pancreatic cancer cells. Up-regulation of cytosolic expression of Smac may act as an effective modifying signal to overcome apoptosis resistance to chemotherapy in pancreatic cancer cells.展开更多
AIM： To explore the relationship between DNA methyltransferase 1 （DNMT1） and hepatitis B virus （HBV）-related hepatocellular carcinoma （HCC） and its biological significance in primary HCC. METHODS： We carried o...AIM： To explore the relationship between DNA methyltransferase 1 （DNMT1） and hepatitis B virus （HBV）-related hepatocellular carcinoma （HCC） and its biological significance in primary HCC. METHODS： We carried out an immunohistochemical examination of DNMT1 in both HCC and paired nonneoplastic liver tissues from Chinese subjects. DNMT1 mRNA was further examined in HCC cell lines by real-time PCR. We inhibited DNMT1 using siRNA and detected the effect of depletion of DNMT1 on cell proliferation ability and cell apoptosis in the HCC celt line SMMC-7721. RESULTS： DNMT1 protein expression was increased in HCCs compared to histologically normal nonneoplastic liver tissues and the incidence of DNMT1 immunoreactivity in HCCs correlated significantly with poor tumor differentiation （P = 0.014）. There were more cases with DNMT1 overexpression in HCC with HBV （42.85%） than in HCC without HBV （28.57%）. However, no significant difference in DNMT1 expression was found in HBV-positive and HBV-negative cases in the Chinese HCC group. There was a trend that DNMT1 RNA expression increased more in HCC cell lines than in pericarcinoma cell lines and normal liver cell lines. In addition, we inhibited DNMT1 using siRNA in the SMMC-7721 HCC cell line and found depletion of DNMT1 suppressed cells growth independent of expression of proliferating cell nuclear antigen （PCNA）, even in HCC cell lines where DNMT1 was stably decreased. CONCLUSION： The findings implied that DNMT1 plays a key role in HBV-retated hepatocellular tumorigenesis. Depletion of DNMT1 mediates growth suppression in SMMC-7721 cells.展开更多
We reported a case of a GCT of the urinary bladder and review the literature.A 23-year-old female presented with dysuria that had lasted for the previous 6 months.MRI revealed a 3×2.5 cm global mass in the anteri...We reported a case of a GCT of the urinary bladder and review the literature.A 23-year-old female presented with dysuria that had lasted for the previous 6 months.MRI revealed a 3×2.5 cm global mass in the anterior wall of urinary bladder.Cystoscopy showed a semispherical tumor approximately 3 cm in diameter that was covered with normal bladder mucosa and extended from the bladder neck to the anterior wall of the bladder.The patient underwent transurethral resection of the tumor.Histological examination and immunohistochemical staining showed a granular cell tumor(GCT).There were no features suggesting a malignant phenotype.On 6 months follow-up,the patient has remained free of bladder recurrence.We recommend careful pathologic assessment for establishing the appropriate diagnosis and either a conservative or aggressive surgical treatment for benign or localized malignant GCT of the urinary bladder,respectively.展开更多
基金This work was supported by grants from Foundation of Science and Technology of Shenzhen (No. 200304250).
文摘Objective： To investigate the relation of X-linked inhibitor of apoptosis （XIAP） and second mitochondria-derived activator of caspase （Smac） signaling pathway to chemoresistance in human pancreatic cancer Panc-1 and BXPC-3 cells. Methods： Apoptosis and the changes of XIAP expression in permeabilized cells induced by cisplatin and 5-fluorouracil （FU） were measured by flow cytometry. The cytosolic expression of XIAP, Smac and caspase-3 was detected by Western blot. A recombinant plasmid vector pEGFP-N1/Smac was constructed and transfected into of Pancol cells. The effect of cytosolic overexpression of Smac on apoptosis of Panc-1 cells was evaluated by flow cytometry. Results： Panc-1 was more resistant to cisplatin or 5-FU induced apoptosis than BXPC-3. Western blot revealed that chemoresistant Panc-1 highly expressed XIAP, and increased cytosolic expression of Smac might be responsible for the marked down-regulation of XIAP in chemo-sensitive BXPC-3 cells after exposure to cisplatin or 5-FU. Furthermore, cytosolic overexpression of Smac could significantly down-regulate the levels of XIAP and promote the activity of caspase-3, as well as sensitize Panc-1 cells to anticancer drug-induced apoptosis. Conclusion： Anticancer drug-induced apoptosis requires mitochondrial release of Smac and downregulation of XIAP, which may be an important determinant of chemo-sensitivity in pancreatic cancer cells. Up-regulation of cytosolic expression of Smac may act as an effective modifying signal to overcome apoptosis resistance to chemotherapy in pancreatic cancer cells.
基金Supported by National Natural Science Foundation of China,No.30470950
文摘AIM： To explore the relationship between DNA methyltransferase 1 （DNMT1） and hepatitis B virus （HBV）-related hepatocellular carcinoma （HCC） and its biological significance in primary HCC. METHODS： We carried out an immunohistochemical examination of DNMT1 in both HCC and paired nonneoplastic liver tissues from Chinese subjects. DNMT1 mRNA was further examined in HCC cell lines by real-time PCR. We inhibited DNMT1 using siRNA and detected the effect of depletion of DNMT1 on cell proliferation ability and cell apoptosis in the HCC celt line SMMC-7721. RESULTS： DNMT1 protein expression was increased in HCCs compared to histologically normal nonneoplastic liver tissues and the incidence of DNMT1 immunoreactivity in HCCs correlated significantly with poor tumor differentiation （P = 0.014）. There were more cases with DNMT1 overexpression in HCC with HBV （42.85%） than in HCC without HBV （28.57%）. However, no significant difference in DNMT1 expression was found in HBV-positive and HBV-negative cases in the Chinese HCC group. There was a trend that DNMT1 RNA expression increased more in HCC cell lines than in pericarcinoma cell lines and normal liver cell lines. In addition, we inhibited DNMT1 using siRNA in the SMMC-7721 HCC cell line and found depletion of DNMT1 suppressed cells growth independent of expression of proliferating cell nuclear antigen （PCNA）, even in HCC cell lines where DNMT1 was stably decreased. CONCLUSION： The findings implied that DNMT1 plays a key role in HBV-retated hepatocellular tumorigenesis. Depletion of DNMT1 mediates growth suppression in SMMC-7721 cells.
文摘We reported a case of a GCT of the urinary bladder and review the literature.A 23-year-old female presented with dysuria that had lasted for the previous 6 months.MRI revealed a 3×2.5 cm global mass in the anterior wall of urinary bladder.Cystoscopy showed a semispherical tumor approximately 3 cm in diameter that was covered with normal bladder mucosa and extended from the bladder neck to the anterior wall of the bladder.The patient underwent transurethral resection of the tumor.Histological examination and immunohistochemical staining showed a granular cell tumor(GCT).There were no features suggesting a malignant phenotype.On 6 months follow-up,the patient has remained free of bladder recurrence.We recommend careful pathologic assessment for establishing the appropriate diagnosis and either a conservative or aggressive surgical treatment for benign or localized malignant GCT of the urinary bladder,respectively.
