Victor Villar | The Beatson Institute for Cancer Research (original) (raw)
Papers by Victor Villar
Copyright © 2013 Victor Villar et al. This is an open access article distributed under the Creati... more Copyright © 2013 Victor Villar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. To determinewhether Ski-interacting protein (SKIP) regulates TGF-
Nature communications, Jan 23, 2017
A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particula... more A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particularly the metabolism of glutamine (glutaminolysis), to control a vast range of cellular processes, including autophagy. As a well-recognized tumour promoter, inhibitors of mTORC1 such as rapamycin have been approved as anti-cancer agents, but their overall outcome in patients is rather poor. Here we show that mTORC1 also presents tumour suppressor features in conditions of nutrient restrictions. Thus, the activation of mTORC1 by glutaminolysis during nutritional imbalance inhibits autophagy and induces apoptosis in cancer cells. Importantly, rapamycin treatment reactivates autophagy and prevents the mTORC1-mediated apoptosis. We also observe that the ability of mTORC1 to activate apoptosis is mediated by the adaptor protein p62. Thus, the mTORC1-mediated upregulation of p62 during nutrient imbalance induces the binding of p62 to caspase 8 and the subsequent activation of the caspase pathwa...
Molecular and Cellular Biochemistry, 2010
Autophagy, 2017
Glutaminolysis plays a critical role in nutrient sufficiency and cell signaling activation in mam... more Glutaminolysis plays a critical role in nutrient sufficiency and cell signaling activation in mammalian cells. Unexpectedly, our recent investigations revealed that the unbalanced activation of glutaminolysis during nutritional restriction causes a particular form of apoptotic cell death, that we termed "glutamoptosis." We found that the inhibition of autophagy is a key step to allow glutamoptosis-mediated cell death. Thus, autophagy controls glutamoptosis during nutritional imbalance.
Molecular & Cellular Oncology, 2017
A master promoter of cell growth, mammalian target of rapamycin (mTOR) is upregulated in a large ... more A master promoter of cell growth, mammalian target of rapamycin (mTOR) is upregulated in a large percentage of cancer cells. Still, targeting mTOR using rapamycin has a limited outcome in patients. Our recent results highlight the additional role of mTOR as a tumor suppressor, explaining these modest results in the clinic.
A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particula... more A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particularly the metabolism of glutamine (glutaminolysis), to control a vast range of cellular processes, including autophagy. As a well-recognized tumour promoter, inhibitors of mTORC1 such as rapamycin have been approved as anti-cancer agents, but their overall outcome in patients is rather poor. Here we show that mTORC1 also presents tumour suppressor features in conditions of nutrient restrictions. Thus, the activation of mTORC1 by glutaminolysis during nutritional imbalance inhibits autophagy and induces apoptosis in cancer cells. Importantly, rapamycin treatment reactivates autophagy and prevents the mTORC1-mediated apoptosis. We also observe that the ability of mTORC1 to activate apoptosis is mediated by the adaptor protein p62. Thus, the mTORC1-mediated upregulation of p62 during nutrient imbalance induces the binding of p62 to caspase 8 and the subsequent activation of the caspase pathway. Our data highlight the role of autophagy as a survival mechanism upon rapamycin treatment.
Autophagy, 2012
Spanel-Borowski, Katharina; Smith, Mark A.; Simone, Cristiano; Simonsen, Anne; Simon, Hans-Uwe; S... more Spanel-Borowski, Katharina; Smith, Mark A.; Simone, Cristiano; Simonsen, Anne; Simon, Hans-Uwe; Silva-Zacarin, Elaine CM; Sibirny, Andrei; Shapiro, Irving M.; Shacka, John J.; Settleman, Jeffrey; Seleverstov, Oleksandr; Seglen, Per O.; Sass, Miklós; Schneider, ...
Scientifica, 2012
Transforming growth factor-beta (TGF-1) is a potent inductor of matrix metalloproteinase-9 (MMP-9... more Transforming growth factor-beta (TGF-1) is a potent inductor of matrix metalloproteinase-9 (MMP-9) in transformed cells. Recently, Ski-interacting protein (SKIP) has been described as a regulator of TGF-1 signal transduction, but its role in the induction of cell malignance by TGF-1 has not been fully elucidated so far. In the present study, we analyzed the role of SKIP on TGF-1-induced MMP-9 production. Mouse transformed keratinocytes (PDV) were stably transfected with SKIP antisense construct. We observed that SKIP depletion provoked an enhancement in the expression of MMP-9 in response to TGF-1 treatment. e downregulation of SKIP produced an enhancement in TGF-1-activated ERK1,2 MAP kinase as well as increased transactivation of downstream Elk1 transcription factor. e increased MMP-9 production in response to TGF-1 was dependent of MAPK activation as PD98059, an MEK inhibitor, reduced MMP-9 expression in SKIP antisense transfected cells. us, we propose SKIP as a regulatory protein in TGF-1-induced MMP-9 expression acting by controlling ERK1,2 signaling in transformed cells.
Purpose. To determine whether Ski-interacting protein (SKIP) regulates TGF-1-stimulated expressio... more Purpose. To determine whether Ski-interacting protein (SKIP) regulates TGF-1-stimulated expression of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9), and uPA Inhibitor (PAI-1) in the androgen-independent human prostate cancer cell model. Materials and Methods. PC-3 prostate cancer cell line was used. The role of SKIP was evaluated using synthetic small interference RNA (siRNA) compounds. The expression of uPA, MMP-9, and PAI-1 was evaluated by zymography assays, RT-PCR, and promoter transactivation analysis. Results. In PC-3 cells TGF-1 treatment stimulated uPA, PAI-1, and MMP-9 expressions. The knockdown of SKIP in PC-3 cells enhanced the basal level of uPA, and TGF-1 treatment inhibited uPA production. Both PAI-1 and MMP-9 production levels were increased in response to TGF-1. The ectopic expression of SKIP inhibited both TGF-1-induced uPA and MMP-9 promoter transactivation, while PAI-1 promoter response to the factor was unaffected. Conclusions. SKIP regulates the expression of uPA, PAI-1, and MMP-9 stimulated by TGF-1 in PC-3 cells. Thus, SKIP is implicated in the regulation of extracellular matrix degradation and can therefore be suggested as a novel therapeutic target in prostate cancer treatment.
PLoS ONE, 2012
The therapeutic effect of doxorubicin (DXR) in the treatment of soft tissue sarcomas (STS) is lim... more The therapeutic effect of doxorubicin (DXR) in the treatment of soft tissue sarcomas (STS) is limited by its toxicity and the development of multidrug resistance (MDR), the latter mainly induced by high expression of efflux pumps (e.g., Pglycoprotein [P-gp]). Therefore, the search for alternative therapies, which sensitize these tumors to chemotherapy while maintaining a low toxicity profile, is a rational approach. We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of the tyrosine kinase inhibitors, nilotinib and imatinib, as single agents or in combination with DXR, in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound nilotinib (1-10 mM) was more potent than imatinib inhibiting the growth of SK-UT-1 and SW982 cells by 33.5-59.6%, respectively. Importantly, only nilotinib synergized the antitumoral effect of DXR (0.05-0.5 mM) by at least 2-fold, which clearly surpassed the mere sum of effects according to isobolographic analysis. Moreover, nilotinib in combination with DXR had a sustained effect on cell number (270.365.8%) even 12 days after withdrawal of drugs compared to DXR alone. On the molecular level, only nilotinib fully blocked FBS-induced ERK1 and p38 MAPK activation, hence, reducing basal and DXR-induced up-regulation of P-gp levels. Moreover, efflux activity of the MDR-related proteins P-gp and MRP-1 was inhibited, altogether resulting in intracellular DXR retention. In high-risk STS tumors 53.8% and 15.4% were positive for P-gp and MRP-1 expression, respectively, with high incidence of P-gp in synovial sarcoma (72.7%). In summary, nilotinib exhibits antiproliferative effects on cellular models of STS and sensitizes them to DXR by reverting DXR-induced P-gp-mediated MDR and inhibiting MRP-1 activity, leading to a synergistic effect with potential for clinical treatment. Citation: Villar VH, Vö gler O, Martínez-Serra J, Ramos R, Calabuig-Fariñ as S, et al. (2012) Nilotinib Counteracts P-Glycoprotein-Mediated Multidrug Resistance and Synergizes the Antitumoral Effect of Doxorubicin in Soft Tissue Sarcomas. PLoS ONE 7(5): e37735.
The Journal of Nutritional Biochemistry, 2014
The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds pr... more The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds present in many plants and dietary products consumed in the Mediterranean diet (e.g., pomace and virgin olive oils). Several nutraceutical activities have been attributed to OLA and MLA, whose antitumoral effects have been extensively evaluated in human adenocarcinomas, but little is known regarding their effectiveness in soft tissue sarcomas (STS). We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of OLA and MLA as single agents or in combination with doxorubicin (DXR) in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound, MLA (10-100 μM) was more potent than OLA, inhibiting the growth of SW982 and SK-UT-1 cells by 70.3±1.11% and 68.8±1.52% at 80 μM, respectively. Importantly, OLA (80 μM) or MLA (30 μM) enhanced the antitumoral effect of DXR (0.5-10 μM) by up to 2.3-fold. On the molecular level, efflux activity of the multidrug resistance protein MRP-1, but not of the P-glycoprotein, was inhibited. Most probably as a consequence, DXR accumulated in these cells. Kinetic studies showed that OLA behaved as a competitive inhibitor of substrate-mediated MRP-1 transport, whereas MLA acted as a non-competitive one. Moreover, none of both triterpenes induced a compensatory increase in MRP-1 expression. In summary, OLA or MLA sensitized cellular models of STS to DXR and selectively inhibited MRP-1 activity, but not its expression, leading to a higher antitumoral effect possibly relevant for clinical treatment.
The remarkable metabolic differences between cancer cells and normal cells result in the potentia... more The remarkable metabolic differences between cancer cells and normal cells result in the potential for targeted cancer therapy. The upregulation of glutaminolysis provides energetic advantages to cancer cells. The recently described link between glutaminolysis and autophagy, mediated by MTORC1, may constitute an attractive target for therapeutic strategies. A combination of therapies targeting simultane-ously cell signaling, cancer metabolism, and autophagy can solve therapy resistance and tumor relapse problems, commonly observed in patients treated with most of the current targeted therapies. In this review we summarize the mechanistic link between glutaminolysis and autophagy, and discuss the impacts of these processes on cancer progression and the potential for therapeutic intervention.
International Journal of Cancer, 2010
TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of ex... more TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of extracellular matrix degrading proteases, cell migration and it is also involved in the epithelial-mesenchymal transition (EMT). In the present work, we analyzed the role of Spred2 in the urokinase-type plasminogen activator (uPA) stimulation, EMT and cell migration by TGF-β1. We found that both the expression of mRNA and the protein level of Spred2 were lower in transformed keratinocytes PDV compared with immortalized keratinocytes MCA-3D. The transient ectopic expression of Spred2 in PDV cells inhibited the TGF-β1-transactivated SRE-Luc reporter which is related with the ERK1,2 signal. The stable ectopic expression of Spred2 in PDV cells (SP cells) led to the loss of ERK 1,2 activation by TGF-β1, although Smad2 activation was not affected, and the knockdown of Spred2 enhanced the activation of ERK1,2 signal by TGF-β1. The increment of uPA expression induced by TGF-β1 was suppressed in SP cells. In contrast, the stimulus on PAI-1 expression was not affected and comparable to parental PDV cells. SP cells under TGF-β1 treatment were unable to display the EMT, since the overexpression of Spred2 abolished the TGF-β1-induced disruption of the E-cadherin cell to cell interactions, reorganization of the actin cytoskeleton and upregulation of the mesenchymal marker vimentin. Finally, SP cells could not respond to the TGF-β1 stimulus on cell migration. Taken together, the data in the present study suggests that Spred2 is a regulator of TGF-β1-induced malignance in transformed keratinocytes.
Chemistry and Physics of Lipids, 2010
Abstracts / Chemistry and Physics of Lipids 163S (2010) S22-S33 S27 estimated to be about 0.2, as... more Abstracts / Chemistry and Physics of Lipids 163S (2010) S22-S33 S27 estimated to be about 0.2, assuming that the surrounding matrix consists of pure DPPC. According to the above assumption, density of the Cer-rich domain was calculated to be 1.014 g/mL from the densities of the bilayers containing less than 10 mol% Cer. The calculated density was between those of the gel and fluid phases and insensitive to the Cer concentration. Furthermore, electron microscopic observation of DPPC/Cer (<10 mol%) bilayers showed flat surfaces between normal ripple structures as seen in pure DPPC bilayers. These results supported the lateral coexistence of Cerrich sub-micron domains (probably in the liquid ordered L o phase) with nearly pure DPPC domains. Thus, even a small fraction of Cer facilitates the formation of L o phase through phase separation.
Chemistry and Physics of Lipids, 2010
The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds pr... more The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds present in many plants and dietary products consumed in the Mediterranean diet (e.g., pomace and virgin olive oils). Several nutraceutical activities have been attributed to OLA and MLA, whose antitumoral effects have been extensively evaluated in human adenocarcinomas, but little is known regarding their effectiveness in soft tissue sarcomas (STS). We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of OLA and MLA as single agents or in combination with doxorubicin (DXR) in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound, MLA (10-100 μM) was more potent than OLA, inhibiting the growth of SW982 and SK-UT-1 cells by 70.3±1.11% and 68.8±1.52% at 80 μM, respectively. Importantly, OLA (80 μM) or MLA (30 μM) enhanced the antitumoral effect of DXR (0.5-10 μM) by up to 2.3-fold. On the molecular level, efflux activity of the multidrug resistance protein MRP-1, but not of the P-glycoprotein, was inhibited. Most probably as a consequence, DXR accumulated in these cells. Kinetic studies showed that OLA behaved as a competitive inhibitor of substrate-mediated MRP-1 transport, whereas MLA acted as a non-competitive one. Moreover, none of both triterpenes induced a compensatory increase in MRP-1 expression. In summary, OLA or MLA sensitized cellular models of STS to DXR and selectively inhibited MRP-1 activity, but not its expression, leading to a higher antitumoral effect possibly relevant for clinical treatment.
Febs Letters
Keywords: Transforming growth factor-b1 Sky-interacting protein Epithelial-mesenchymal transition... more Keywords: Transforming growth factor-b1 Sky-interacting protein Epithelial-mesenchymal transition Urokinase type plasminogen activator Plasminogen activator inhibitor type-1 Migration a b s t r a c t Transforming growth factor-b1 (TGF-b1) potently induces the epithelial-mesenchymal transition (EMT) during tumoral progression. Although Sky-interacting protein (SKIP) regulates TGF-b1induced Smad activation, its role in the induction of cell malignance remains uncertain. We found that TGF-b1 increases SKIP expression in PDV cells. In cells stably transfected with SKIP antisense, AS-S, Smad3 activation decreased, along with an inhibition of TGF-b1-induced EMT, and the cells were sensitized to the TGF-b1-dependent inhibition of proliferation. Also, AS-S cells showed a weaker migration and invasion response. Moreover, TGF-b1-induced urokinase-type plasminogen activator expression was inhibited, concomitantly with a TGF-b1-independent increment of the plasminogen-activator inhibitor-1 expression. Thus, these results suggest that SKIP is required for EMT and invasiveness induced by TGF-b1 in transformed cells.
International Journal of Cancer, 2010
TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of ex... more TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of extracellular matrix degrading proteases, cell migration and it is also involved in the epithelial-mesenchymal transition (EMT). In the present work, we analyzed the role of Spred2 in the urokinase-type plasminogen activator (uPA) stimulation, EMT and cell migration by TGF-β1. We found that both the expression of mRNA and the protein level of Spred2 were lower in transformed keratinocytes PDV compared with immortalized keratinocytes MCA-3D. The transient ectopic expression of Spred2 in PDV cells inhibited the TGF-β1-transactivated SRE-Luc reporter which is related with the ERK1,2 signal. The stable ectopic expression of Spred2 in PDV cells (SP cells) led to the loss of ERK 1,2 activation by TGF-β1, although Smad2 activation was not affected, and the knockdown of Spred2 enhanced the activation of ERK1,2 signal by TGF-β1. The increment of uPA expression induced by TGF-β1 was suppressed in SP cells. In contrast, the stimulus on PAI-1 expression was not affected and comparable to parental PDV cells. SP cells under TGF-β1 treatment were unable to display the EMT, since the overexpression of Spred2 abolished the TGF-β1-induced disruption of the E-cadherin cell to cell interactions, reorganization of the actin cytoskeleton and upregulation of the mesenchymal marker vimentin. Finally, SP cells could not respond to the TGF-β1 stimulus on cell migration. Taken together, the data in the present study suggests that Spred2 is a regulator of TGF-β1-induced malignance in transformed keratinocytes.
Copyright © 2013 Victor Villar et al. This is an open access article distributed under the Creati... more Copyright © 2013 Victor Villar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. To determinewhether Ski-interacting protein (SKIP) regulates TGF-
Nature communications, Jan 23, 2017
A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particula... more A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particularly the metabolism of glutamine (glutaminolysis), to control a vast range of cellular processes, including autophagy. As a well-recognized tumour promoter, inhibitors of mTORC1 such as rapamycin have been approved as anti-cancer agents, but their overall outcome in patients is rather poor. Here we show that mTORC1 also presents tumour suppressor features in conditions of nutrient restrictions. Thus, the activation of mTORC1 by glutaminolysis during nutritional imbalance inhibits autophagy and induces apoptosis in cancer cells. Importantly, rapamycin treatment reactivates autophagy and prevents the mTORC1-mediated apoptosis. We also observe that the ability of mTORC1 to activate apoptosis is mediated by the adaptor protein p62. Thus, the mTORC1-mediated upregulation of p62 during nutrient imbalance induces the binding of p62 to caspase 8 and the subsequent activation of the caspase pathwa...
Molecular and Cellular Biochemistry, 2010
Autophagy, 2017
Glutaminolysis plays a critical role in nutrient sufficiency and cell signaling activation in mam... more Glutaminolysis plays a critical role in nutrient sufficiency and cell signaling activation in mammalian cells. Unexpectedly, our recent investigations revealed that the unbalanced activation of glutaminolysis during nutritional restriction causes a particular form of apoptotic cell death, that we termed "glutamoptosis." We found that the inhibition of autophagy is a key step to allow glutamoptosis-mediated cell death. Thus, autophagy controls glutamoptosis during nutritional imbalance.
Molecular & Cellular Oncology, 2017
A master promoter of cell growth, mammalian target of rapamycin (mTOR) is upregulated in a large ... more A master promoter of cell growth, mammalian target of rapamycin (mTOR) is upregulated in a large percentage of cancer cells. Still, targeting mTOR using rapamycin has a limited outcome in patients. Our recent results highlight the additional role of mTOR as a tumor suppressor, explaining these modest results in the clinic.
A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particula... more A master coordinator of cell growth, mTORC1 is activated by different metabolic inputs, particularly the metabolism of glutamine (glutaminolysis), to control a vast range of cellular processes, including autophagy. As a well-recognized tumour promoter, inhibitors of mTORC1 such as rapamycin have been approved as anti-cancer agents, but their overall outcome in patients is rather poor. Here we show that mTORC1 also presents tumour suppressor features in conditions of nutrient restrictions. Thus, the activation of mTORC1 by glutaminolysis during nutritional imbalance inhibits autophagy and induces apoptosis in cancer cells. Importantly, rapamycin treatment reactivates autophagy and prevents the mTORC1-mediated apoptosis. We also observe that the ability of mTORC1 to activate apoptosis is mediated by the adaptor protein p62. Thus, the mTORC1-mediated upregulation of p62 during nutrient imbalance induces the binding of p62 to caspase 8 and the subsequent activation of the caspase pathway. Our data highlight the role of autophagy as a survival mechanism upon rapamycin treatment.
Autophagy, 2012
Spanel-Borowski, Katharina; Smith, Mark A.; Simone, Cristiano; Simonsen, Anne; Simon, Hans-Uwe; S... more Spanel-Borowski, Katharina; Smith, Mark A.; Simone, Cristiano; Simonsen, Anne; Simon, Hans-Uwe; Silva-Zacarin, Elaine CM; Sibirny, Andrei; Shapiro, Irving M.; Shacka, John J.; Settleman, Jeffrey; Seleverstov, Oleksandr; Seglen, Per O.; Sass, Miklós; Schneider, ...
Scientifica, 2012
Transforming growth factor-beta (TGF-1) is a potent inductor of matrix metalloproteinase-9 (MMP-9... more Transforming growth factor-beta (TGF-1) is a potent inductor of matrix metalloproteinase-9 (MMP-9) in transformed cells. Recently, Ski-interacting protein (SKIP) has been described as a regulator of TGF-1 signal transduction, but its role in the induction of cell malignance by TGF-1 has not been fully elucidated so far. In the present study, we analyzed the role of SKIP on TGF-1-induced MMP-9 production. Mouse transformed keratinocytes (PDV) were stably transfected with SKIP antisense construct. We observed that SKIP depletion provoked an enhancement in the expression of MMP-9 in response to TGF-1 treatment. e downregulation of SKIP produced an enhancement in TGF-1-activated ERK1,2 MAP kinase as well as increased transactivation of downstream Elk1 transcription factor. e increased MMP-9 production in response to TGF-1 was dependent of MAPK activation as PD98059, an MEK inhibitor, reduced MMP-9 expression in SKIP antisense transfected cells. us, we propose SKIP as a regulatory protein in TGF-1-induced MMP-9 expression acting by controlling ERK1,2 signaling in transformed cells.
Purpose. To determine whether Ski-interacting protein (SKIP) regulates TGF-1-stimulated expressio... more Purpose. To determine whether Ski-interacting protein (SKIP) regulates TGF-1-stimulated expression of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9), and uPA Inhibitor (PAI-1) in the androgen-independent human prostate cancer cell model. Materials and Methods. PC-3 prostate cancer cell line was used. The role of SKIP was evaluated using synthetic small interference RNA (siRNA) compounds. The expression of uPA, MMP-9, and PAI-1 was evaluated by zymography assays, RT-PCR, and promoter transactivation analysis. Results. In PC-3 cells TGF-1 treatment stimulated uPA, PAI-1, and MMP-9 expressions. The knockdown of SKIP in PC-3 cells enhanced the basal level of uPA, and TGF-1 treatment inhibited uPA production. Both PAI-1 and MMP-9 production levels were increased in response to TGF-1. The ectopic expression of SKIP inhibited both TGF-1-induced uPA and MMP-9 promoter transactivation, while PAI-1 promoter response to the factor was unaffected. Conclusions. SKIP regulates the expression of uPA, PAI-1, and MMP-9 stimulated by TGF-1 in PC-3 cells. Thus, SKIP is implicated in the regulation of extracellular matrix degradation and can therefore be suggested as a novel therapeutic target in prostate cancer treatment.
PLoS ONE, 2012
The therapeutic effect of doxorubicin (DXR) in the treatment of soft tissue sarcomas (STS) is lim... more The therapeutic effect of doxorubicin (DXR) in the treatment of soft tissue sarcomas (STS) is limited by its toxicity and the development of multidrug resistance (MDR), the latter mainly induced by high expression of efflux pumps (e.g., Pglycoprotein [P-gp]). Therefore, the search for alternative therapies, which sensitize these tumors to chemotherapy while maintaining a low toxicity profile, is a rational approach. We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of the tyrosine kinase inhibitors, nilotinib and imatinib, as single agents or in combination with DXR, in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound nilotinib (1-10 mM) was more potent than imatinib inhibiting the growth of SK-UT-1 and SW982 cells by 33.5-59.6%, respectively. Importantly, only nilotinib synergized the antitumoral effect of DXR (0.05-0.5 mM) by at least 2-fold, which clearly surpassed the mere sum of effects according to isobolographic analysis. Moreover, nilotinib in combination with DXR had a sustained effect on cell number (270.365.8%) even 12 days after withdrawal of drugs compared to DXR alone. On the molecular level, only nilotinib fully blocked FBS-induced ERK1 and p38 MAPK activation, hence, reducing basal and DXR-induced up-regulation of P-gp levels. Moreover, efflux activity of the MDR-related proteins P-gp and MRP-1 was inhibited, altogether resulting in intracellular DXR retention. In high-risk STS tumors 53.8% and 15.4% were positive for P-gp and MRP-1 expression, respectively, with high incidence of P-gp in synovial sarcoma (72.7%). In summary, nilotinib exhibits antiproliferative effects on cellular models of STS and sensitizes them to DXR by reverting DXR-induced P-gp-mediated MDR and inhibiting MRP-1 activity, leading to a synergistic effect with potential for clinical treatment. Citation: Villar VH, Vö gler O, Martínez-Serra J, Ramos R, Calabuig-Fariñ as S, et al. (2012) Nilotinib Counteracts P-Glycoprotein-Mediated Multidrug Resistance and Synergizes the Antitumoral Effect of Doxorubicin in Soft Tissue Sarcomas. PLoS ONE 7(5): e37735.
The Journal of Nutritional Biochemistry, 2014
The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds pr... more The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds present in many plants and dietary products consumed in the Mediterranean diet (e.g., pomace and virgin olive oils). Several nutraceutical activities have been attributed to OLA and MLA, whose antitumoral effects have been extensively evaluated in human adenocarcinomas, but little is known regarding their effectiveness in soft tissue sarcomas (STS). We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of OLA and MLA as single agents or in combination with doxorubicin (DXR) in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound, MLA (10-100 μM) was more potent than OLA, inhibiting the growth of SW982 and SK-UT-1 cells by 70.3±1.11% and 68.8±1.52% at 80 μM, respectively. Importantly, OLA (80 μM) or MLA (30 μM) enhanced the antitumoral effect of DXR (0.5-10 μM) by up to 2.3-fold. On the molecular level, efflux activity of the multidrug resistance protein MRP-1, but not of the P-glycoprotein, was inhibited. Most probably as a consequence, DXR accumulated in these cells. Kinetic studies showed that OLA behaved as a competitive inhibitor of substrate-mediated MRP-1 transport, whereas MLA acted as a non-competitive one. Moreover, none of both triterpenes induced a compensatory increase in MRP-1 expression. In summary, OLA or MLA sensitized cellular models of STS to DXR and selectively inhibited MRP-1 activity, but not its expression, leading to a higher antitumoral effect possibly relevant for clinical treatment.
The remarkable metabolic differences between cancer cells and normal cells result in the potentia... more The remarkable metabolic differences between cancer cells and normal cells result in the potential for targeted cancer therapy. The upregulation of glutaminolysis provides energetic advantages to cancer cells. The recently described link between glutaminolysis and autophagy, mediated by MTORC1, may constitute an attractive target for therapeutic strategies. A combination of therapies targeting simultane-ously cell signaling, cancer metabolism, and autophagy can solve therapy resistance and tumor relapse problems, commonly observed in patients treated with most of the current targeted therapies. In this review we summarize the mechanistic link between glutaminolysis and autophagy, and discuss the impacts of these processes on cancer progression and the potential for therapeutic intervention.
International Journal of Cancer, 2010
TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of ex... more TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of extracellular matrix degrading proteases, cell migration and it is also involved in the epithelial-mesenchymal transition (EMT). In the present work, we analyzed the role of Spred2 in the urokinase-type plasminogen activator (uPA) stimulation, EMT and cell migration by TGF-β1. We found that both the expression of mRNA and the protein level of Spred2 were lower in transformed keratinocytes PDV compared with immortalized keratinocytes MCA-3D. The transient ectopic expression of Spred2 in PDV cells inhibited the TGF-β1-transactivated SRE-Luc reporter which is related with the ERK1,2 signal. The stable ectopic expression of Spred2 in PDV cells (SP cells) led to the loss of ERK 1,2 activation by TGF-β1, although Smad2 activation was not affected, and the knockdown of Spred2 enhanced the activation of ERK1,2 signal by TGF-β1. The increment of uPA expression induced by TGF-β1 was suppressed in SP cells. In contrast, the stimulus on PAI-1 expression was not affected and comparable to parental PDV cells. SP cells under TGF-β1 treatment were unable to display the EMT, since the overexpression of Spred2 abolished the TGF-β1-induced disruption of the E-cadherin cell to cell interactions, reorganization of the actin cytoskeleton and upregulation of the mesenchymal marker vimentin. Finally, SP cells could not respond to the TGF-β1 stimulus on cell migration. Taken together, the data in the present study suggests that Spred2 is a regulator of TGF-β1-induced malignance in transformed keratinocytes.
Chemistry and Physics of Lipids, 2010
Abstracts / Chemistry and Physics of Lipids 163S (2010) S22-S33 S27 estimated to be about 0.2, as... more Abstracts / Chemistry and Physics of Lipids 163S (2010) S22-S33 S27 estimated to be about 0.2, assuming that the surrounding matrix consists of pure DPPC. According to the above assumption, density of the Cer-rich domain was calculated to be 1.014 g/mL from the densities of the bilayers containing less than 10 mol% Cer. The calculated density was between those of the gel and fluid phases and insensitive to the Cer concentration. Furthermore, electron microscopic observation of DPPC/Cer (<10 mol%) bilayers showed flat surfaces between normal ripple structures as seen in pure DPPC bilayers. These results supported the lateral coexistence of Cerrich sub-micron domains (probably in the liquid ordered L o phase) with nearly pure DPPC domains. Thus, even a small fraction of Cer facilitates the formation of L o phase through phase separation.
Chemistry and Physics of Lipids, 2010
The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds pr... more The pentacyclic triterpenes oleanolic acid (OLA) and maslinic acid (MLA) are natural compounds present in many plants and dietary products consumed in the Mediterranean diet (e.g., pomace and virgin olive oils). Several nutraceutical activities have been attributed to OLA and MLA, whose antitumoral effects have been extensively evaluated in human adenocarcinomas, but little is known regarding their effectiveness in soft tissue sarcomas (STS). We assessed efficacy and molecular mechanisms involved in the antiproliferative effects of OLA and MLA as single agents or in combination with doxorubicin (DXR) in human synovial sarcoma SW982 and leiomyosarcoma SK-UT-1 cells. As single compound, MLA (10-100 μM) was more potent than OLA, inhibiting the growth of SW982 and SK-UT-1 cells by 70.3±1.11% and 68.8±1.52% at 80 μM, respectively. Importantly, OLA (80 μM) or MLA (30 μM) enhanced the antitumoral effect of DXR (0.5-10 μM) by up to 2.3-fold. On the molecular level, efflux activity of the multidrug resistance protein MRP-1, but not of the P-glycoprotein, was inhibited. Most probably as a consequence, DXR accumulated in these cells. Kinetic studies showed that OLA behaved as a competitive inhibitor of substrate-mediated MRP-1 transport, whereas MLA acted as a non-competitive one. Moreover, none of both triterpenes induced a compensatory increase in MRP-1 expression. In summary, OLA or MLA sensitized cellular models of STS to DXR and selectively inhibited MRP-1 activity, but not its expression, leading to a higher antitumoral effect possibly relevant for clinical treatment.
Febs Letters
Keywords: Transforming growth factor-b1 Sky-interacting protein Epithelial-mesenchymal transition... more Keywords: Transforming growth factor-b1 Sky-interacting protein Epithelial-mesenchymal transition Urokinase type plasminogen activator Plasminogen activator inhibitor type-1 Migration a b s t r a c t Transforming growth factor-b1 (TGF-b1) potently induces the epithelial-mesenchymal transition (EMT) during tumoral progression. Although Sky-interacting protein (SKIP) regulates TGF-b1induced Smad activation, its role in the induction of cell malignance remains uncertain. We found that TGF-b1 increases SKIP expression in PDV cells. In cells stably transfected with SKIP antisense, AS-S, Smad3 activation decreased, along with an inhibition of TGF-b1-induced EMT, and the cells were sensitized to the TGF-b1-dependent inhibition of proliferation. Also, AS-S cells showed a weaker migration and invasion response. Moreover, TGF-b1-induced urokinase-type plasminogen activator expression was inhibited, concomitantly with a TGF-b1-independent increment of the plasminogen-activator inhibitor-1 expression. Thus, these results suggest that SKIP is required for EMT and invasiveness induced by TGF-b1 in transformed cells.
International Journal of Cancer, 2010
TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of ex... more TGF-β1 is a potent inductor of malignance in cancer cells. TGF-β1 stimulates the expression of extracellular matrix degrading proteases, cell migration and it is also involved in the epithelial-mesenchymal transition (EMT). In the present work, we analyzed the role of Spred2 in the urokinase-type plasminogen activator (uPA) stimulation, EMT and cell migration by TGF-β1. We found that both the expression of mRNA and the protein level of Spred2 were lower in transformed keratinocytes PDV compared with immortalized keratinocytes MCA-3D. The transient ectopic expression of Spred2 in PDV cells inhibited the TGF-β1-transactivated SRE-Luc reporter which is related with the ERK1,2 signal. The stable ectopic expression of Spred2 in PDV cells (SP cells) led to the loss of ERK 1,2 activation by TGF-β1, although Smad2 activation was not affected, and the knockdown of Spred2 enhanced the activation of ERK1,2 signal by TGF-β1. The increment of uPA expression induced by TGF-β1 was suppressed in SP cells. In contrast, the stimulus on PAI-1 expression was not affected and comparable to parental PDV cells. SP cells under TGF-β1 treatment were unable to display the EMT, since the overexpression of Spred2 abolished the TGF-β1-induced disruption of the E-cadherin cell to cell interactions, reorganization of the actin cytoskeleton and upregulation of the mesenchymal marker vimentin. Finally, SP cells could not respond to the TGF-β1 stimulus on cell migration. Taken together, the data in the present study suggests that Spred2 is a regulator of TGF-β1-induced malignance in transformed keratinocytes.