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
NKX3.1, which is a prostate-specific homeobox gene, plays an important role in prostate cancer and usually functions as a tumour suppressor gene. In this study, we investigated the inhibitory effect of NKX3,1 on insul...NKX3.1, which is a prostate-specific homeobox gene, plays an important role in prostate cancer and usually functions as a tumour suppressor gene. In this study, we investigated the inhibitory effect of NKX3,1 on insulin-like growth factor （IGF）- 1R expression and its downstream signalling pathway in PC3 cells, PC3 cells were stably transfected with NKX3.1 expression plasmid （pcDNA3.1-NKX3.1） or vector plasmid （pcDNA3.1＋）. The IGF-IR mRNA and protein expression levels were assessed in PC3-NKX3.1 transfectants by reverse transcriptase-polymerase chain reaction （RT-PCR） and Western blotting. The expression and activation of IGF-1/IGF-1R downstream signalling targets were examined by Western blotting and luciferase reporter assay. The cells were subsequently treated with relevant concentrations of IGF-1. The effect of IGF-1 on cell growth was examined by 3-（4,5）-dimethylthiahiazo（-z-yl）-3, 5-diphenytetrazoliumromide （MTT） assay and flow cytometry analysis. A significant suppression of IGF-1R mRNA and protein expression was observed after forced expression of NKX3.1 in PC3 cells. Correspondingly, the forced expression of NKX3.1 decreased IGF-l-induced phosphorylation of extracellular signal-regulated kinase 1/2 （ERK1/2） and protein kinase B （AKT） and activation of the Elk-1 transcription factor and downregulated the expression of the downstream target genes c-fos and cyclin D1. Furthermore, the forced expression of NKX3.1 inhibited IGF-l-induced cell growth. In conclusion, NKX3.1 could downregulate IGF-1R expression and could inhibit IGF-1R-mediated mitogen-activated protein kinase （MAPK）/ERK and AKT signalling pathways, which might partially leads to the inhibition of IGF-l-induced cell growth. This study provides new insights into the molecular mechanisms that NKX3,1 exerts against prostate cancer and ultimately expands the scope of alternative approaches in advanced prostate cancer therapy.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.
文摘NKX3.1, which is a prostate-specific homeobox gene, plays an important role in prostate cancer and usually functions as a tumour suppressor gene. In this study, we investigated the inhibitory effect of NKX3,1 on insulin-like growth factor （IGF）- 1R expression and its downstream signalling pathway in PC3 cells, PC3 cells were stably transfected with NKX3.1 expression plasmid （pcDNA3.1-NKX3.1） or vector plasmid （pcDNA3.1＋）. The IGF-IR mRNA and protein expression levels were assessed in PC3-NKX3.1 transfectants by reverse transcriptase-polymerase chain reaction （RT-PCR） and Western blotting. The expression and activation of IGF-1/IGF-1R downstream signalling targets were examined by Western blotting and luciferase reporter assay. The cells were subsequently treated with relevant concentrations of IGF-1. The effect of IGF-1 on cell growth was examined by 3-（4,5）-dimethylthiahiazo（-z-yl）-3, 5-diphenytetrazoliumromide （MTT） assay and flow cytometry analysis. A significant suppression of IGF-1R mRNA and protein expression was observed after forced expression of NKX3.1 in PC3 cells. Correspondingly, the forced expression of NKX3.1 decreased IGF-l-induced phosphorylation of extracellular signal-regulated kinase 1/2 （ERK1/2） and protein kinase B （AKT） and activation of the Elk-1 transcription factor and downregulated the expression of the downstream target genes c-fos and cyclin D1. Furthermore, the forced expression of NKX3.1 inhibited IGF-l-induced cell growth. In conclusion, NKX3.1 could downregulate IGF-1R expression and could inhibit IGF-1R-mediated mitogen-activated protein kinase （MAPK）/ERK and AKT signalling pathways, which might partially leads to the inhibition of IGF-l-induced cell growth. This study provides new insights into the molecular mechanisms that NKX3,1 exerts against prostate cancer and ultimately expands the scope of alternative approaches in advanced prostate cancer therapy.
