AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell lin...AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell line SGC7901 with pcDNA3.1(+)-PDX1 vector(SGC-PDX1). Transfection with empty pcDNA3.1 vector(SGC-pcDNA) served as control. Comparative protein profiles of the two groups were analyzed by two-dimensional electrophoresis basedproteomics(2 DE gel-based proteomics). The differential proteins identified by 2 DE were further validated by qRTPCR and immunoblotting. Finally, co-immunoprecipitation was used to determine any direct interactions between PDX1 and the differential proteins.RESULTS2 DE gel proteomics identified seven differential proteins in SGC-PDX1 when compared with those in SGC-pcDNA. These included four heat shock proteins(HSPs; HSP70 p1 B, HSP70 p8, HSP60, HSP27) and three other proteins(ER60, laminin receptor 1, similar to epsilon isoform of 14-3-3 protein). Immunoblotting validated the expression of the HSPs(HSP70, HSP60, HSP27). Furthermore, their expressions were lowered to 80%, 20% and 24%, respectively, in SGC-PDX1, while PDX1 exhibited a 9-fold increase, compared to SGC-pcDNA. However, qRT-PCR analysis revealed that mRNA levels of the HSP s were increased in SGC-PDX1, suggesting that the expression of the HSP s was post-translationally regulated by the PDX1 protein. Finally, co-immunoprecipitation failed to identify any direct interaction between PDX1 and HSP70 proteins.CONCLUSION This study demonstrates the potential involvement of HSPs in PDX1-mediated effects on the genesis of gastric cancer.展开更多
AIM： To study the correlations of Pancreas duodenal homeobox-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation. METHODS： Reverse tra...AIM： To study the correlations of Pancreas duodenal homeobox-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation. METHODS： Reverse transcriptase-polymerase chain reaction （RT-PCR） was used to detect PDX-1 mRNA expression in pancreatic cancer tissue and normal pancreatic tissue. The expression of PDX-1 protein was measured by Western blot and immunohistochemistry. Immunohistochemistry was also used to detect proliferative cell nuclear antigen （PCNA）. Correlations of PDX-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation, were analyzed by using χ^2 test. RESULTS： Immunohistochemistry showed that 41.1% of pancreatic cancers were positive for PDX-1 expression, but normal pancreatic tissue except islets showed no staining for PDX-1. In consistent with the result of imunohistochemistry, Western blot showed that 37.5% of pancreatic cancers were positive for PDX-1. RT-PCR showed that PDX-1 expression was significantly higher in pancreatic cancer tissues than normal pancreatic tissues （2^-3.56±0.35 vs 2^-8.76±0.14, p 〈 0.01）. Lymph node metastasis （P 〈 0.01）, TNM grading （P 〈 0.05）, pathological grading （P 〈 0.05） and tumor cell proliferation （P 〈 0.01） were significantly correlated with PDX-1 expression levels. CONCLUSION： PDX-1 is re-expressed in pancreatic cancer, and PDX-l-positive pancreatic cancer cells show more malignant potential compared to PDX-l-negative cells. Therefore, PDX-l-positive cells may be tumor stemcells and PDX-1 may act as alternate surface marker of pancreatic cancer stem cells.展开更多
基金Supported by Guangdong Natural Science Fund,No.2016A030313765Guangdong medical scientific research fund,No.A2017070 and No.A2017122
文摘AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell line SGC7901 with pcDNA3.1(+)-PDX1 vector(SGC-PDX1). Transfection with empty pcDNA3.1 vector(SGC-pcDNA) served as control. Comparative protein profiles of the two groups were analyzed by two-dimensional electrophoresis basedproteomics(2 DE gel-based proteomics). The differential proteins identified by 2 DE were further validated by qRTPCR and immunoblotting. Finally, co-immunoprecipitation was used to determine any direct interactions between PDX1 and the differential proteins.RESULTS2 DE gel proteomics identified seven differential proteins in SGC-PDX1 when compared with those in SGC-pcDNA. These included four heat shock proteins(HSPs; HSP70 p1 B, HSP70 p8, HSP60, HSP27) and three other proteins(ER60, laminin receptor 1, similar to epsilon isoform of 14-3-3 protein). Immunoblotting validated the expression of the HSPs(HSP70, HSP60, HSP27). Furthermore, their expressions were lowered to 80%, 20% and 24%, respectively, in SGC-PDX1, while PDX1 exhibited a 9-fold increase, compared to SGC-pcDNA. However, qRT-PCR analysis revealed that mRNA levels of the HSP s were increased in SGC-PDX1, suggesting that the expression of the HSP s was post-translationally regulated by the PDX1 protein. Finally, co-immunoprecipitation failed to identify any direct interaction between PDX1 and HSP70 proteins.CONCLUSION This study demonstrates the potential involvement of HSPs in PDX1-mediated effects on the genesis of gastric cancer.
基金Supported by the grants from the National Natural Science Foundation of China, No.30571817the PhD Programs Foundation of Ministry of Education of China, No. 20050487077
文摘AIM： To study the correlations of Pancreas duodenal homeobox-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation. METHODS： Reverse transcriptase-polymerase chain reaction （RT-PCR） was used to detect PDX-1 mRNA expression in pancreatic cancer tissue and normal pancreatic tissue. The expression of PDX-1 protein was measured by Western blot and immunohistochemistry. Immunohistochemistry was also used to detect proliferative cell nuclear antigen （PCNA）. Correlations of PDX-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation, were analyzed by using χ^2 test. RESULTS： Immunohistochemistry showed that 41.1% of pancreatic cancers were positive for PDX-1 expression, but normal pancreatic tissue except islets showed no staining for PDX-1. In consistent with the result of imunohistochemistry, Western blot showed that 37.5% of pancreatic cancers were positive for PDX-1. RT-PCR showed that PDX-1 expression was significantly higher in pancreatic cancer tissues than normal pancreatic tissues （2^-3.56±0.35 vs 2^-8.76±0.14, p 〈 0.01）. Lymph node metastasis （P 〈 0.01）, TNM grading （P 〈 0.05）, pathological grading （P 〈 0.05） and tumor cell proliferation （P 〈 0.01） were significantly correlated with PDX-1 expression levels. CONCLUSION： PDX-1 is re-expressed in pancreatic cancer, and PDX-l-positive pancreatic cancer cells show more malignant potential compared to PDX-l-negative cells. Therefore, PDX-l-positive cells may be tumor stemcells and PDX-1 may act as alternate surface marker of pancreatic cancer stem cells.
