We investigated the ability of NK4, an antagonist of human hepatocyte growth factor （HGF）, to inhibit the influence of HGF on proliferation, migration, invasion and apoptosis of human prostate cancer cells. Expressi...We investigated the ability of NK4, an antagonist of human hepatocyte growth factor （HGF）, to inhibit the influence of HGF on proliferation, migration, invasion and apoptosis of human prostate cancer cells. Expression vector pBudCE4.1-EGFP-NK4 containing NK4 cDNA was used to transfect human prostate cancer DU145 cells, and the effects of the autocrine NK4 on tumor cell proliferation, migration, invasion and apoptosis were assessed in vitro. in vivo, we subcutaneously implanted DU145 cells, mock-transfected clone （DU145/empty vector） cells and NK4- transfected clone （DU145/NK4） cells into nude mice, and then evaluated tumor growth, cell proliferation and cell apoptosis in vivo. We found that DU145/NK4 cells expressed NK4 protein. In the in vitro study, autocrine NK4 at- tenuated the HGF-induced tumor cell proliferation, migration and invasion, and stimulated apoptosis. Furthermore, autocrine NK4 effectively inhibited the HGF-induced phosphorylation of c-Met, extracellular signal-regulated kinase-1 （ERK1）. and protein kinase B 1/2 （Aktl/2）. Histological examination revealed that autocrine NK4 inhibited prolifera- tion and accelerated apoptosis of prostate cancer cells. These results show that genetic modification of DU145 cells with NK4 cDNA yields a significant effect on their proliferation, migration, invasion and apoptosis. Molecular targeting of HGF/c-Met by NK4 could be applied as a novel therapeutic approach to prostate cancer.展开更多
Hepatocyte growth factor （HGF） is a glycoprotein that induces prostate cancer cell proliferation, migration and invasion. The activation of transient receptor potential canonical 6 （TRPC6） channels is considered i...Hepatocyte growth factor （HGF） is a glycoprotein that induces prostate cancer cell proliferation, migration and invasion. The activation of transient receptor potential canonical 6 （TRPC6） channels is considered important in promoting prostate cancer cell proliferation. In this study, we assessed the role of endogenous TRPC6 channels in the HGF-induced cell proliferation of prostate cancer. Reverse transcription-PCR and Western blotting were used to investigate TRPC6 expression. Electrophysiological techniques （whole-cell patch clamp configuration） and Ca^2＋ imaging analysis were used to investigate the channel activity in cells. The effects of TRPC6 channels on cell cycle progression, cell apoptosis and cell growth were also examined. TRPC6 and c-MET were expressed in DU145 and PC3 cells. In addition, functional TRPC6 channels were present in DU145 and PC3 cells, and TRPC6 knockdown suppressed TRPC-Iike currents evoked by oleoyl-2-acetyl-sn-glycerol （OAG）. Inhibition of TRPC6 channels in DU145 and PC3 cells abolished OAG- and HGF-induced Ca^2＋ entry. Furthermore, inhibition of TRPC6 channels arrested DU145 and PC3 cells at the G2/M phase and suppressed HGF-induced cell proliferation. Collectively, our results indicate that TRPC6 has an important role in HGF-induced DU145 and PC3 cell proliferation.展开更多
Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihyd...Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.展开更多
The proteasome inhibitor, bortezomib, has been demonstrated to sensitize tumor cells to tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-mediated apoptosis. Natural killer （NK） cells represent poten...The proteasome inhibitor, bortezomib, has been demonstrated to sensitize tumor cells to tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-mediated apoptosis. Natural killer （NK） cells represent potent antitumor effector cells. They also express TRAIL. Therefore, we investigated whether bortezomib could sensitize tumor cells to NK cell-mediated killing, and have the same effect in human prostate cancer cell lines （LNCaP and DU145）. We found that bortezomib strongly inhibits proliferation in both cell lines. Furthermore, compared with LNCaP cells, DU145 cells are more sensitive to bortezomib-induced apoptosis. However, bortezomib is unable to sensitize these two cell lines to NK cell-mediated killing in short-term assays. In long-term assays, we found that killing mediated by activated NK cells following bortezomib treatment leads to greater antitumor effects than either treatment alone. In addition, treatment with bortezomib causes these cells to upregulate apoptosis-related mRNA as well as death receptors and downregulate the major histocompatibility class （MHC）-I molecule on the cell surface of DU145 cells. In contrast, LNCaP cells are not sensitized by this treatment. Death receptors and the MHC-I molecule did not change in this cell line. These data suggest that bortezomib can be used to sensitize prostate cancer cells to NK cell-mediated killing and improve current cancer therapies. This theral）eutic stratelzv may be more effective in I）atients with androeen-insensitive orostate cancer.展开更多
The incidence of prostate cancer is rising in the Asia-Pacific region as well as other countries. Androgen-ablation therapy is clinically useful in the androgen-dependent phenotype however, many patients progress to h...The incidence of prostate cancer is rising in the Asia-Pacific region as well as other countries. Androgen-ablation therapy is clinically useful in the androgen-dependent phenotype however, many patients progress to hormone refractory prostate cancer that is difficult to treat and needs newer interventions that are more effective. The objective of this study was to determine functionally-relevant biological networks, to appreciate the potential crosstalk between signaling members, and to identify biomarker signatures in prostate cancer. We used microarray analyses to identify key genes that were upregulated or down regulated at least five-fold in human prostate cancer and constructed canonical interaction networks that are important in prostate cancer through metabolomics analyses. Our prostate cancer network architecture revealed several key biomarkers including ERK1/2, JNK, p38, MEK, PI3 K, NFκB, AP-1, 14-3-3, VEGF, PDGF, Rb, WNT8 A, WNT10 A, CD44, ESR2, FSH and LH. Furthermore, the top ten transcription factors identified by TFBS-association signature analysis in the regulatory elements of co-regulated biomarkers were delineated, which may crosstalk with upstream or downstream genes elicited in our network architecture. Taken together, our results demonstrate that the regulatory interaction networks in prostate cancer provide a universal view of crosstalk between important biomarkers, i.e., key players in the pathogenesis of this disease. This will facilitate more rapid screening of functional biomarkers in early/intermediate drug discovery.展开更多
文摘We investigated the ability of NK4, an antagonist of human hepatocyte growth factor （HGF）, to inhibit the influence of HGF on proliferation, migration, invasion and apoptosis of human prostate cancer cells. Expression vector pBudCE4.1-EGFP-NK4 containing NK4 cDNA was used to transfect human prostate cancer DU145 cells, and the effects of the autocrine NK4 on tumor cell proliferation, migration, invasion and apoptosis were assessed in vitro. in vivo, we subcutaneously implanted DU145 cells, mock-transfected clone （DU145/empty vector） cells and NK4- transfected clone （DU145/NK4） cells into nude mice, and then evaluated tumor growth, cell proliferation and cell apoptosis in vivo. We found that DU145/NK4 cells expressed NK4 protein. In the in vitro study, autocrine NK4 at- tenuated the HGF-induced tumor cell proliferation, migration and invasion, and stimulated apoptosis. Furthermore, autocrine NK4 effectively inhibited the HGF-induced phosphorylation of c-Met, extracellular signal-regulated kinase-1 （ERK1）. and protein kinase B 1/2 （Aktl/2）. Histological examination revealed that autocrine NK4 inhibited prolifera- tion and accelerated apoptosis of prostate cancer cells. These results show that genetic modification of DU145 cells with NK4 cDNA yields a significant effect on their proliferation, migration, invasion and apoptosis. Molecular targeting of HGF/c-Met by NK4 could be applied as a novel therapeutic approach to prostate cancer.
文摘Hepatocyte growth factor （HGF） is a glycoprotein that induces prostate cancer cell proliferation, migration and invasion. The activation of transient receptor potential canonical 6 （TRPC6） channels is considered important in promoting prostate cancer cell proliferation. In this study, we assessed the role of endogenous TRPC6 channels in the HGF-induced cell proliferation of prostate cancer. Reverse transcription-PCR and Western blotting were used to investigate TRPC6 expression. Electrophysiological techniques （whole-cell patch clamp configuration） and Ca^2＋ imaging analysis were used to investigate the channel activity in cells. The effects of TRPC6 channels on cell cycle progression, cell apoptosis and cell growth were also examined. TRPC6 and c-MET were expressed in DU145 and PC3 cells. In addition, functional TRPC6 channels were present in DU145 and PC3 cells, and TRPC6 knockdown suppressed TRPC-Iike currents evoked by oleoyl-2-acetyl-sn-glycerol （OAG）. Inhibition of TRPC6 channels in DU145 and PC3 cells abolished OAG- and HGF-induced Ca^2＋ entry. Furthermore, inhibition of TRPC6 channels arrested DU145 and PC3 cells at the G2/M phase and suppressed HGF-induced cell proliferation. Collectively, our results indicate that TRPC6 has an important role in HGF-induced DU145 and PC3 cell proliferation.
基金supported by Cancer Institute NSW CDF fellowship (YZ)Cure Cancer Foundation of Australia (YZ)+3 种基金Cancer Council New South Wales (MJS, YZ, HZ, and CRD)Prostate Cancer Foundation of Australia (MJS, YZ, HZ, and CRD)NH and MRC Early Career Fellowship 596870 (YZ)German Research Foundation HO 5109/2-1 and HO 5109/2-2 (KH)
文摘Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.
文摘The proteasome inhibitor, bortezomib, has been demonstrated to sensitize tumor cells to tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-mediated apoptosis. Natural killer （NK） cells represent potent antitumor effector cells. They also express TRAIL. Therefore, we investigated whether bortezomib could sensitize tumor cells to NK cell-mediated killing, and have the same effect in human prostate cancer cell lines （LNCaP and DU145）. We found that bortezomib strongly inhibits proliferation in both cell lines. Furthermore, compared with LNCaP cells, DU145 cells are more sensitive to bortezomib-induced apoptosis. However, bortezomib is unable to sensitize these two cell lines to NK cell-mediated killing in short-term assays. In long-term assays, we found that killing mediated by activated NK cells following bortezomib treatment leads to greater antitumor effects than either treatment alone. In addition, treatment with bortezomib causes these cells to upregulate apoptosis-related mRNA as well as death receptors and downregulate the major histocompatibility class （MHC）-I molecule on the cell surface of DU145 cells. In contrast, LNCaP cells are not sensitized by this treatment. Death receptors and the MHC-I molecule did not change in this cell line. These data suggest that bortezomib can be used to sensitize prostate cancer cells to NK cell-mediated killing and improve current cancer therapies. This theral）eutic stratelzv may be more effective in I）atients with androeen-insensitive orostate cancer.
基金RO1 CA 094828 to Prof. Ah-Ng Tony Kong and in part by R21 CA133675 to Dr.Li Cai both from the National Institutes of Health(NIH)
文摘The incidence of prostate cancer is rising in the Asia-Pacific region as well as other countries. Androgen-ablation therapy is clinically useful in the androgen-dependent phenotype however, many patients progress to hormone refractory prostate cancer that is difficult to treat and needs newer interventions that are more effective. The objective of this study was to determine functionally-relevant biological networks, to appreciate the potential crosstalk between signaling members, and to identify biomarker signatures in prostate cancer. We used microarray analyses to identify key genes that were upregulated or down regulated at least five-fold in human prostate cancer and constructed canonical interaction networks that are important in prostate cancer through metabolomics analyses. Our prostate cancer network architecture revealed several key biomarkers including ERK1/2, JNK, p38, MEK, PI3 K, NFκB, AP-1, 14-3-3, VEGF, PDGF, Rb, WNT8 A, WNT10 A, CD44, ESR2, FSH and LH. Furthermore, the top ten transcription factors identified by TFBS-association signature analysis in the regulatory elements of co-regulated biomarkers were delineated, which may crosstalk with upstream or downstream genes elicited in our network architecture. Taken together, our results demonstrate that the regulatory interaction networks in prostate cancer provide a universal view of crosstalk between important biomarkers, i.e., key players in the pathogenesis of this disease. This will facilitate more rapid screening of functional biomarkers in early/intermediate drug discovery.
