Inflammation is considered one of major causes of cancer and hamper inflammation is possible targ... more Inflammation is considered one of major causes of cancer and hamper inflammation is possible target of chemotherapy and chemopreventive treatment. Retinoids have potential anti-inflammatory effects. We investigated the effects of the retinoid all-trans retinoic acid (RA) and the 6-OH-11-O-hydroxyphenantrene (IIF), a specific ligand of Retinoid XReceptor (RXR), on the normal keratinocyte cell line NCTC and on the neuroepithelioma cancer cell line SKNMC. IIF and RA treatment inhibited proliferation and viability in a time and dose dependent manner. Interestingly, IIF was significantly more effective than RA and reduced of 50% SKNMC cells after 24 h of treatment at the dose 30 µM. The effects are further evident in cancer cells than normal cells where retinoids reduce slightly the viability. We stimulated inflammation with LPS and TNFα in normal and cancer cells and we observed the effects of IIF on several catechins involved in inflammation. A reduction of TNFα, IL2 expression and IL6 production after treatment with IIF in SKNMC cells was reported. Moreover, IIF reduced IL18, IL15 and IFNγ expression in inflammatory NCTC cells. Finally, inflammation induction increased while IIF treatment reduced matrix metalloproteinase-2 and-9 activity, two proteins that are involved in cell invasion and metastasis. In conclusion, we suggest that retinoids as IIF could be used to overcome inflammation in human carcinoma and it may be a powerful tool in the development of cancer therapies.
The recapitulation of primary tumour heterogenity and the existence of a minor sub-population of ... more The recapitulation of primary tumour heterogenity and the existence of a minor sub-population of cancer cells, capable of initiating tumour growth in xenografts on serial passages, led to the hypothesis that cancer stem cells (CSCs) exist. CSCs are present in many tumours, among which is breast cancer. Breast CSCs (BCSCs) are likely to sustain the growth of the primary tumour mass, as well as to be responsible for disease relapse and metastatic spreading. Consequently, BCSCs represent the most significant target for new drugs in breast cancer therapy. Both the hypoxic condition in BCSCs biology and pro-inflammatory cytokine network has gained increasing importance in the recent past. Breast stromal cells are crucial components of the tumours milieu and are a major source of inflammatory mediators. Recently, the anti-inflammatory role of some nuclear receptors ligands has emerged in several diseases, including breast cancer. Therefore, the use of nuclear receptors ligands may be a valid strategy to inhibit BCSCs viability and consequently breast cancer growth and disease relapse.
The hypoxic environment is a crucial component of the cancer stem cell niche and it is capable of... more The hypoxic environment is a crucial component of the cancer stem cell niche and it is capable of eliciting stem cell features in cancer cells. We previously reported that SNAI2 up-regulates the expression of Carbonic Anhydrase iso-enzyme 9 (CA9) in hypoxic MCF7 cells. Here we show that SNAI2 down-regulates miR34a expression in hypoxic MCF7 cell-derived mammospheres. Next, we report on the capability of miR34a to decrease CA9 mRNA stability and CA9 protein expression. We also convey that the over-expression of cloned CA9-mRNA-3'UTR increases the mRNA half-life and protein levels of two miR34a targets JAGGED1 and NOTCH3. The data here reported shows that the SNAI2-dependent down-regulation of miR34a substantially contributes to the post-transcriptional up-regulation of CA9, and that CA9-mRNA-3'UTR acts as an endogenous microRNA sponge. We conclude that CA9/miR34 interplay shares in the hypoxic regulation of mammospheres and therefore may play a relevant role in the hypoxic breast cancer stem cell niche. This article is protected by copyright. All rights reserved.
Molecules with synergistic effects often enhance the benefits of cancer therapy. We observed that... more Molecules with synergistic effects often enhance the benefits of cancer therapy. We observed that the major catechin of green tea, (-)-Epigallocatechin-3-gallate (EGCG), induced retinoid X receptor-g (RXRg) expression in the SK-Ch-A1 cholangiocarcinoma cell line and in two colon carcinoma cell lines (LoVo and the derivative multi-drug resistant LoVoMDR). On this basis, we analyzed the effects of EGCG in combination with an RXRg ligand, 6-OH-11-Ohydroxyphenantrene (IIF), or with a ligand of retinoic acid receptor, all-trans-retinoic acid (RA). IIF alone and in combination with EGCG activated the retinoic X response elements and induced the germ cell nuclear factor. In parallel, EGCG induced 67 kDa laminin receptor expression alone and in combination with IIF. We observed a synergistic growth inhibition with EGCG and IIF in combination at lower doses. These effects were accompanied by apoptosis activation through the mitochondrial pathway. Moreover, in LoVo cell line we observed an in...
The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the ke... more The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the key mechanisms underlying the development of resistance to tamoxifen in breast cancer patients. As EGCG [(-)-epigallocatechin-3-gallate], the most active catechin present in green tea, has been shown to down-regulate EGFR, we studied the effects of 10-100 μg/ml EGCG treatment on growth and invasion in a breast carcinoma cell line resistant to tamoxifen [MCF-7Tam (MCF-7 breast carcinoma cell line resistant to tamoxifen) cells] and parental MCF-7. A dose-dependent down-regulation of EGFR mRNA expression and protein level occurred after 50 μg/ml EGCG treatment of MCF-7Tam cells. EGFR molecules on the plasma membrane surface of MCF-7Tam cells significantly decreased. EGFR phosphorylation (Tyr-992, Tyr-1045 and Tyr-1068) was higher in MCF-7Tam than in MCF-7 and it was reduced by EGCG treatment. ERK (extracellular regulated kinase) and phospho-ERK p42/44 were also down-regulated by EGCG treatment and in vitro cell growth and invasion decreased. MMP-2 (matrix metalloproteinase-2) and MMP-9, which are implicated in cell invasion and metastasis, and EMMPRIN (extracellular matrix metalloproteinase inducer), a glycoprotein able to activate MMPs, were significantly reduced after 50 μg/ml EGCG treatment. In keeping with this, TIMP-1 (tissue inhibitor of metalloproteinases-1) and TIMP-2, which down-regulate MMPs, increased after EGCG treatment. Altogether, the present data demonstrated that EGCG could attenuate the tamoxifen-resistant phenotype of MCF-7Tam cells. EGCG could stop MCF-7Tam cell growth and in vitro invasion through down-regulation of EGFR and other molecules implicated in aggressive biological behaviour. The present data support the hypothesis that EGCG is an interesting molecule to be investigated in tamoxifen-resistant breast carcinoma.
We investigated the anticancer effect of EGCG treatment on a breast carcinoma cell line resistant... more We investigated the anticancer effect of EGCG treatment on a breast carcinoma cell line resistant to tamoxifen (MCF-7Tam cells). As there are no reports about the molecular mechanisms implicated in EGCG treatment of tamoxifen resistant breast carcinoma cells, we studied the effects of EGCG treatment on three plasma membrane proteins that are involved in the mechanism of drug-resistance: Multidrug Resistance
Experimental data from in vitro and in vivo models indicate that peroxisome proliferator-activate... more Experimental data from in vitro and in vivo models indicate that peroxisome proliferator-activated receptor (PPAR) ligand activation regulates differentiation and induces cell growth arrest and apoptosis in a variety of cancer types. Thiazolidinediones such as ciglitazone (CGZ) constitute the most well-known synthetic ligands for PPARgamma. We previously reported a remarkable antitumor effect of the retinoid 6-OH-11-O-hydroxyphenantrene (IIF), synthetic retinoid X receptors (RXRs) agonist, on many cancer cell lines. Since PPARs bind to DNA as heterodimers with RXRs, in this study we investigated if IIF potentiates the antitumoral properties of the PPARgamma ligand CGZ in glioblastoma U87MG and melanoma G361 cells. Our results show that either IIF or CGZ inhibited cell growth and tissue invasion ability, but these properties were enhanced by using IIF and CGZ in combined treatment. Since matrix metalloproteinases (MMPs) play a major role in tumor cell invasion, we analyzed the effect...
All-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acu... more All-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL). Nevertheless, most of these patients develop RA resistance and relapse. In an attemp to mimic clinical conditions for the treatment of leukemia, a stably RA-resistant subclone of the human promyelocytic leukemia cell line HL60 (HL60-R) was developed to study the antiproliferative and proapoptotic effect of the retinoid IIF (6-OH-11-O-hydroxyphenantrene) in comparison with RA. Moreover whether the inhibitor of histone deacetylase (HDAC) activity, valproic acid (VPA), could enhance sensitivity to retinoids in HL60-R cells was evaluated. Finally, the effect of IIF on the expression of multidrug resistance-associated protein 1 (MRP1) and P-glycoprotein (P-gp) was evaluated. It was found that IIF strongly suppressed cell proliferation (as measured by growth curves) and induced apoptosis (as measured by DNA fragmentation and Annexin V detection assays), while R...
The development of multidrug resistance (MDR) is one of the major causes of failure in cancer the... more The development of multidrug resistance (MDR) is one of the major causes of failure in cancer therapy. The use of cell lines with acquired resistance to anticancer agents represents a very good tool for investigation into the possibility of reversal of MDR. In this study the ability of all-trans-retinoic acid (RA) and its derivative 6-OH-11-O-hydroxyphenanthrene (IIF; pat. WIPO W000 /117143) as antitumor agents was investigated in the human colon carcinoma cell line LoVo and in the counterpart resistant derivative LoVo/MDR cell line. Cell proliferation was measured by MTT assay, apoptosis was evaluated using DNA fragmentation and Annexin V detection assay. Retinoids suppressed cell proliferation in a time- and dose-dependent manner. Interestingly, IIF was significantly more effective than RA, particularly on LoVo/MDR cells. RA and IIF induced apoptosis in both cell lines, with IIF effect significantly higher than that of RA. Furthermore, on the basis that MDR phenotype is often caus...
The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the ke... more The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the key mechanisms underlying the development of resistance to tamoxifen in breast cancer patients. As EGCG [(-)-epigallocatechin-3-gallate], the most active catechin present in green tea, has been shown to down-regulate EGFR, we studied the effects of 10-100 μg/ml EGCG treatment on growth and invasion in a breast carcinoma cell line resistant to tamoxifen [MCF-7Tam (MCF-7 breast carcinoma cell line resistant to tamoxifen) cells] and parental MCF-7. A dose-dependent down-regulation of EGFR mRNA expression and protein level occurred after 50 μg/ml EGCG treatment of MCF-7Tam cells. EGFR molecules on the plasma membrane surface of MCF-7Tam cells significantly decreased. EGFR phosphorylation (Tyr-992, Tyr-1045 and Tyr-1068) was higher in MCF-7Tam than in MCF-7 and it was reduced by EGCG treatment. ERK (extracellular regulated kinase) and phospho-ERK p42/44 were also down-regulated by EGCG treatmen...
Valproic acid (VPA) is an established drug in the long-term therapy of epilepsy. Recently, VPA ha... more Valproic acid (VPA) is an established drug in the long-term therapy of epilepsy. Recently, VPA has demonstrated antitumor activity as a histone deacetylase (HDAC) inhibitor. In this study, the anticancer properties of VPA on neural crest-derived human tumor cell lines G361 melanoma, U87MG glioblastoma and SKNMC Askin tumor cells were investigated. The effect of VPA on cell growth, apoptotic activity and invasive ability were evaluated. Firstly, VPA induced cell growth inhibition and apoptotic activity, as demonstrated by sulforhodamine B protein assay, annexin V assay and by Western blot analysis for Bcl2 and Bax expression levels, in all three cell lines. In addition, VPA led to a decrease of HDAC-1 protein level, as assessed by Western blot analysis. Treatment with VPA caused a decrease in the invasive ability of all three cell lines. Since the invasion process involves a complex system of tightly regulated proteases, matrix metalloproteinases (MMPs) and their tissue-specific inhi...
Glioblastomas, the most malignant and prevalent brain tumors which remain incurable, are characte... more Glioblastomas, the most malignant and prevalent brain tumors which remain incurable, are characterized by both extensive proliferation and invasive growth. We previously reported a remarkable antitumoral effect of the retinoid 6-OH-11-O-hydroxyphenantrene (IIF) on neuroblastoma, leukemia and colon carcinoma cells. In this study we examined the effect of IIF on proliferation, apoptosis and cell invasion in the human glioblastoma cell line U87MG, in comparison with all-trans-retinoic acid (RA). Our results showed that both retinoids induced cell growth inhibition and apoptosis in a dose- and time-dependent manner. We also demonstrated that the invasive ability of glioblastoma cells decreased after treatment with IIF or RA. Since cell invasion involves a complex system of tightly regulated proteases, matrix metalloproteinases (MMPs) and their specific inhibitors, tissue inhibitors of MMPs (TIMPs), we analysed the effect of IIF on MMP and TIMP expression in comparison with RA. Treatment with both retinoids resulted in a marked decrease of MMP2 and MMP9 expression and of lytic activity of MMP2. In addition, exposure to IIF led to enhanced expression of TIMP2. Collectively, our results demonstrated the effectiveness of both IIF and RA in inhibiting proliferation, cell migration, and the invasive potential of glioblastoma U87MG cells. Notably, the anticancer activity of IIF, on the whole, was more pronounced than that of RA. Therefore, these findings, besides providing further evidence that IIF may be a powerful tool in the development of cancer treatments, suggest that IIF may have therapeutic potential against the invasiveness of brain tumors.
... Massimo Benaglia *a, Angelo Alberti a, Enzo Spisni b, Alessio Papi b, Emanuele Treossi a and ... more ... Massimo Benaglia *a, Angelo Alberti a, Enzo Spisni b, Alessio Papi b, Emanuele Treossi a and Vincenzo Palermo a. a ISOF - Consiglio Nazionale ... 9, C. Boyer, J. Liu, V. Bulmus, TP Davis, C. Barner-Kowollik and MH Stenzel, Macromolecules, 2008, 41, 5641–5650 CrossRef CAS ...
Nuclear retinoid X receptors (RXRs) and peroxisome proliferator-activated receptors (PPARs are po... more Nuclear retinoid X receptors (RXRs) and peroxisome proliferator-activated receptors (PPARs are potential candidates as drug target for cancer prevention and treatment. We investigated if the rexinoid 6-OH-11-O-hydroxyphenantrene (IIF) potentiates the antitumoral properties of PPARgamma ligands as ciglitazone and pioglitazone, on two colon cancer cell lines: HCA-7 and HCT-116. Drugs inhibited cell growth and induced apoptosis synergistically. The combination resulted in a decrease of cyclooxigenase-2, metalloproteinases-2 and -9 expression level and activity while PPARgamma, RXRgamma and tissue inhibitors of metalloproteinase-1 and -2 expression were increased. Finally, IIF potentiated PPAR transcriptional activity by enhancement of peroxisome proliferator response elements transactivation.
The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the ke... more The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the key mechanisms underlying the development of resistance to tamoxifen in breast cancer patients. As EGCG [(-)-epigallocatechin-3-gallate], the most active catechin present in green tea, has been shown to down-regulate EGFR, we studied the effects of 10-100 μg/ml EGCG treatment on growth and invasion in a breast carcinoma cell line resistant to tamoxifen [MCF-7Tam (MCF-7 breast carcinoma cell line resistant to tamoxifen) cells] and parental MCF-7. A dose-dependent down-regulation of EGFR mRNA expression and protein level occurred after 50 μg/ml EGCG treatment of MCF-7Tam cells. EGFR molecules on the plasma membrane surface of MCF-7Tam cells significantly decreased. EGFR phosphorylation (Tyr-992, Tyr-1045 and Tyr-1068) was higher in MCF-7Tam than in MCF-7 and it was reduced by EGCG treatment. ERK (extracellular regulated kinase) and phospho-ERK p42/44 were also down-regulated by EGCG treatment and in vitro cell growth and invasion decreased. MMP-2 (matrix metalloproteinase-2) and MMP-9, which are implicated in cell invasion and metastasis, and EMMPRIN (extracellular matrix metalloproteinase inducer), a glycoprotein able to activate MMPs, were significantly reduced after 50 μg/ml EGCG treatment. In keeping with this, TIMP-1 (tissue inhibitor of metalloproteinases-1) and TIMP-2, which down-regulate MMPs, increased after EGCG treatment. Altogether, the present data demonstrated that EGCG could attenuate the tamoxifen-resistant phenotype of MCF-7Tam cells. EGCG could stop MCF-7Tam cell growth and in vitro invasion through down-regulation of EGFR and other molecules implicated in aggressive biological behaviour. The present data support the hypothesis that EGCG is an interesting molecule to be investigated in tamoxifen-resistant breast carcinoma.
Inflammation is considered one of major causes of cancer and hamper inflammation is possible targ... more Inflammation is considered one of major causes of cancer and hamper inflammation is possible target of chemotherapy and chemopreventive treatment. Retinoids have potential anti-inflammatory effects. We investigated the effects of the retinoid all-trans retinoic acid (RA) and the 6-OH-11-O-hydroxyphenantrene (IIF), a specific ligand of Retinoid XReceptor (RXR), on the normal keratinocyte cell line NCTC and on the neuroepithelioma cancer cell line SKNMC. IIF and RA treatment inhibited proliferation and viability in a time and dose dependent manner. Interestingly, IIF was significantly more effective than RA and reduced of 50% SKNMC cells after 24 h of treatment at the dose 30 µM. The effects are further evident in cancer cells than normal cells where retinoids reduce slightly the viability. We stimulated inflammation with LPS and TNFα in normal and cancer cells and we observed the effects of IIF on several catechins involved in inflammation. A reduction of TNFα, IL2 expression and IL6 production after treatment with IIF in SKNMC cells was reported. Moreover, IIF reduced IL18, IL15 and IFNγ expression in inflammatory NCTC cells. Finally, inflammation induction increased while IIF treatment reduced matrix metalloproteinase-2 and-9 activity, two proteins that are involved in cell invasion and metastasis. In conclusion, we suggest that retinoids as IIF could be used to overcome inflammation in human carcinoma and it may be a powerful tool in the development of cancer therapies.
The recapitulation of primary tumour heterogenity and the existence of a minor sub-population of ... more The recapitulation of primary tumour heterogenity and the existence of a minor sub-population of cancer cells, capable of initiating tumour growth in xenografts on serial passages, led to the hypothesis that cancer stem cells (CSCs) exist. CSCs are present in many tumours, among which is breast cancer. Breast CSCs (BCSCs) are likely to sustain the growth of the primary tumour mass, as well as to be responsible for disease relapse and metastatic spreading. Consequently, BCSCs represent the most significant target for new drugs in breast cancer therapy. Both the hypoxic condition in BCSCs biology and pro-inflammatory cytokine network has gained increasing importance in the recent past. Breast stromal cells are crucial components of the tumours milieu and are a major source of inflammatory mediators. Recently, the anti-inflammatory role of some nuclear receptors ligands has emerged in several diseases, including breast cancer. Therefore, the use of nuclear receptors ligands may be a valid strategy to inhibit BCSCs viability and consequently breast cancer growth and disease relapse.
The hypoxic environment is a crucial component of the cancer stem cell niche and it is capable of... more The hypoxic environment is a crucial component of the cancer stem cell niche and it is capable of eliciting stem cell features in cancer cells. We previously reported that SNAI2 up-regulates the expression of Carbonic Anhydrase iso-enzyme 9 (CA9) in hypoxic MCF7 cells. Here we show that SNAI2 down-regulates miR34a expression in hypoxic MCF7 cell-derived mammospheres. Next, we report on the capability of miR34a to decrease CA9 mRNA stability and CA9 protein expression. We also convey that the over-expression of cloned CA9-mRNA-3'UTR increases the mRNA half-life and protein levels of two miR34a targets JAGGED1 and NOTCH3. The data here reported shows that the SNAI2-dependent down-regulation of miR34a substantially contributes to the post-transcriptional up-regulation of CA9, and that CA9-mRNA-3'UTR acts as an endogenous microRNA sponge. We conclude that CA9/miR34 interplay shares in the hypoxic regulation of mammospheres and therefore may play a relevant role in the hypoxic breast cancer stem cell niche. This article is protected by copyright. All rights reserved.
Molecules with synergistic effects often enhance the benefits of cancer therapy. We observed that... more Molecules with synergistic effects often enhance the benefits of cancer therapy. We observed that the major catechin of green tea, (-)-Epigallocatechin-3-gallate (EGCG), induced retinoid X receptor-g (RXRg) expression in the SK-Ch-A1 cholangiocarcinoma cell line and in two colon carcinoma cell lines (LoVo and the derivative multi-drug resistant LoVoMDR). On this basis, we analyzed the effects of EGCG in combination with an RXRg ligand, 6-OH-11-Ohydroxyphenantrene (IIF), or with a ligand of retinoic acid receptor, all-trans-retinoic acid (RA). IIF alone and in combination with EGCG activated the retinoic X response elements and induced the germ cell nuclear factor. In parallel, EGCG induced 67 kDa laminin receptor expression alone and in combination with IIF. We observed a synergistic growth inhibition with EGCG and IIF in combination at lower doses. These effects were accompanied by apoptosis activation through the mitochondrial pathway. Moreover, in LoVo cell line we observed an in...
The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the ke... more The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the key mechanisms underlying the development of resistance to tamoxifen in breast cancer patients. As EGCG [(-)-epigallocatechin-3-gallate], the most active catechin present in green tea, has been shown to down-regulate EGFR, we studied the effects of 10-100 μg/ml EGCG treatment on growth and invasion in a breast carcinoma cell line resistant to tamoxifen [MCF-7Tam (MCF-7 breast carcinoma cell line resistant to tamoxifen) cells] and parental MCF-7. A dose-dependent down-regulation of EGFR mRNA expression and protein level occurred after 50 μg/ml EGCG treatment of MCF-7Tam cells. EGFR molecules on the plasma membrane surface of MCF-7Tam cells significantly decreased. EGFR phosphorylation (Tyr-992, Tyr-1045 and Tyr-1068) was higher in MCF-7Tam than in MCF-7 and it was reduced by EGCG treatment. ERK (extracellular regulated kinase) and phospho-ERK p42/44 were also down-regulated by EGCG treatment and in vitro cell growth and invasion decreased. MMP-2 (matrix metalloproteinase-2) and MMP-9, which are implicated in cell invasion and metastasis, and EMMPRIN (extracellular matrix metalloproteinase inducer), a glycoprotein able to activate MMPs, were significantly reduced after 50 μg/ml EGCG treatment. In keeping with this, TIMP-1 (tissue inhibitor of metalloproteinases-1) and TIMP-2, which down-regulate MMPs, increased after EGCG treatment. Altogether, the present data demonstrated that EGCG could attenuate the tamoxifen-resistant phenotype of MCF-7Tam cells. EGCG could stop MCF-7Tam cell growth and in vitro invasion through down-regulation of EGFR and other molecules implicated in aggressive biological behaviour. The present data support the hypothesis that EGCG is an interesting molecule to be investigated in tamoxifen-resistant breast carcinoma.
We investigated the anticancer effect of EGCG treatment on a breast carcinoma cell line resistant... more We investigated the anticancer effect of EGCG treatment on a breast carcinoma cell line resistant to tamoxifen (MCF-7Tam cells). As there are no reports about the molecular mechanisms implicated in EGCG treatment of tamoxifen resistant breast carcinoma cells, we studied the effects of EGCG treatment on three plasma membrane proteins that are involved in the mechanism of drug-resistance: Multidrug Resistance
Experimental data from in vitro and in vivo models indicate that peroxisome proliferator-activate... more Experimental data from in vitro and in vivo models indicate that peroxisome proliferator-activated receptor (PPAR) ligand activation regulates differentiation and induces cell growth arrest and apoptosis in a variety of cancer types. Thiazolidinediones such as ciglitazone (CGZ) constitute the most well-known synthetic ligands for PPARgamma. We previously reported a remarkable antitumor effect of the retinoid 6-OH-11-O-hydroxyphenantrene (IIF), synthetic retinoid X receptors (RXRs) agonist, on many cancer cell lines. Since PPARs bind to DNA as heterodimers with RXRs, in this study we investigated if IIF potentiates the antitumoral properties of the PPARgamma ligand CGZ in glioblastoma U87MG and melanoma G361 cells. Our results show that either IIF or CGZ inhibited cell growth and tissue invasion ability, but these properties were enhanced by using IIF and CGZ in combined treatment. Since matrix metalloproteinases (MMPs) play a major role in tumor cell invasion, we analyzed the effect...
All-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acu... more All-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL). Nevertheless, most of these patients develop RA resistance and relapse. In an attemp to mimic clinical conditions for the treatment of leukemia, a stably RA-resistant subclone of the human promyelocytic leukemia cell line HL60 (HL60-R) was developed to study the antiproliferative and proapoptotic effect of the retinoid IIF (6-OH-11-O-hydroxyphenantrene) in comparison with RA. Moreover whether the inhibitor of histone deacetylase (HDAC) activity, valproic acid (VPA), could enhance sensitivity to retinoids in HL60-R cells was evaluated. Finally, the effect of IIF on the expression of multidrug resistance-associated protein 1 (MRP1) and P-glycoprotein (P-gp) was evaluated. It was found that IIF strongly suppressed cell proliferation (as measured by growth curves) and induced apoptosis (as measured by DNA fragmentation and Annexin V detection assays), while R...
The development of multidrug resistance (MDR) is one of the major causes of failure in cancer the... more The development of multidrug resistance (MDR) is one of the major causes of failure in cancer therapy. The use of cell lines with acquired resistance to anticancer agents represents a very good tool for investigation into the possibility of reversal of MDR. In this study the ability of all-trans-retinoic acid (RA) and its derivative 6-OH-11-O-hydroxyphenanthrene (IIF; pat. WIPO W000 /117143) as antitumor agents was investigated in the human colon carcinoma cell line LoVo and in the counterpart resistant derivative LoVo/MDR cell line. Cell proliferation was measured by MTT assay, apoptosis was evaluated using DNA fragmentation and Annexin V detection assay. Retinoids suppressed cell proliferation in a time- and dose-dependent manner. Interestingly, IIF was significantly more effective than RA, particularly on LoVo/MDR cells. RA and IIF induced apoptosis in both cell lines, with IIF effect significantly higher than that of RA. Furthermore, on the basis that MDR phenotype is often caus...
The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the ke... more The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the key mechanisms underlying the development of resistance to tamoxifen in breast cancer patients. As EGCG [(-)-epigallocatechin-3-gallate], the most active catechin present in green tea, has been shown to down-regulate EGFR, we studied the effects of 10-100 μg/ml EGCG treatment on growth and invasion in a breast carcinoma cell line resistant to tamoxifen [MCF-7Tam (MCF-7 breast carcinoma cell line resistant to tamoxifen) cells] and parental MCF-7. A dose-dependent down-regulation of EGFR mRNA expression and protein level occurred after 50 μg/ml EGCG treatment of MCF-7Tam cells. EGFR molecules on the plasma membrane surface of MCF-7Tam cells significantly decreased. EGFR phosphorylation (Tyr-992, Tyr-1045 and Tyr-1068) was higher in MCF-7Tam than in MCF-7 and it was reduced by EGCG treatment. ERK (extracellular regulated kinase) and phospho-ERK p42/44 were also down-regulated by EGCG treatmen...
Valproic acid (VPA) is an established drug in the long-term therapy of epilepsy. Recently, VPA ha... more Valproic acid (VPA) is an established drug in the long-term therapy of epilepsy. Recently, VPA has demonstrated antitumor activity as a histone deacetylase (HDAC) inhibitor. In this study, the anticancer properties of VPA on neural crest-derived human tumor cell lines G361 melanoma, U87MG glioblastoma and SKNMC Askin tumor cells were investigated. The effect of VPA on cell growth, apoptotic activity and invasive ability were evaluated. Firstly, VPA induced cell growth inhibition and apoptotic activity, as demonstrated by sulforhodamine B protein assay, annexin V assay and by Western blot analysis for Bcl2 and Bax expression levels, in all three cell lines. In addition, VPA led to a decrease of HDAC-1 protein level, as assessed by Western blot analysis. Treatment with VPA caused a decrease in the invasive ability of all three cell lines. Since the invasion process involves a complex system of tightly regulated proteases, matrix metalloproteinases (MMPs) and their tissue-specific inhi...
Glioblastomas, the most malignant and prevalent brain tumors which remain incurable, are characte... more Glioblastomas, the most malignant and prevalent brain tumors which remain incurable, are characterized by both extensive proliferation and invasive growth. We previously reported a remarkable antitumoral effect of the retinoid 6-OH-11-O-hydroxyphenantrene (IIF) on neuroblastoma, leukemia and colon carcinoma cells. In this study we examined the effect of IIF on proliferation, apoptosis and cell invasion in the human glioblastoma cell line U87MG, in comparison with all-trans-retinoic acid (RA). Our results showed that both retinoids induced cell growth inhibition and apoptosis in a dose- and time-dependent manner. We also demonstrated that the invasive ability of glioblastoma cells decreased after treatment with IIF or RA. Since cell invasion involves a complex system of tightly regulated proteases, matrix metalloproteinases (MMPs) and their specific inhibitors, tissue inhibitors of MMPs (TIMPs), we analysed the effect of IIF on MMP and TIMP expression in comparison with RA. Treatment with both retinoids resulted in a marked decrease of MMP2 and MMP9 expression and of lytic activity of MMP2. In addition, exposure to IIF led to enhanced expression of TIMP2. Collectively, our results demonstrated the effectiveness of both IIF and RA in inhibiting proliferation, cell migration, and the invasive potential of glioblastoma U87MG cells. Notably, the anticancer activity of IIF, on the whole, was more pronounced than that of RA. Therefore, these findings, besides providing further evidence that IIF may be a powerful tool in the development of cancer treatments, suggest that IIF may have therapeutic potential against the invasiveness of brain tumors.
... Massimo Benaglia *a, Angelo Alberti a, Enzo Spisni b, Alessio Papi b, Emanuele Treossi a and ... more ... Massimo Benaglia *a, Angelo Alberti a, Enzo Spisni b, Alessio Papi b, Emanuele Treossi a and Vincenzo Palermo a. a ISOF - Consiglio Nazionale ... 9, C. Boyer, J. Liu, V. Bulmus, TP Davis, C. Barner-Kowollik and MH Stenzel, Macromolecules, 2008, 41, 5641–5650 CrossRef CAS ...
Nuclear retinoid X receptors (RXRs) and peroxisome proliferator-activated receptors (PPARs are po... more Nuclear retinoid X receptors (RXRs) and peroxisome proliferator-activated receptors (PPARs are potential candidates as drug target for cancer prevention and treatment. We investigated if the rexinoid 6-OH-11-O-hydroxyphenantrene (IIF) potentiates the antitumoral properties of PPARgamma ligands as ciglitazone and pioglitazone, on two colon cancer cell lines: HCA-7 and HCT-116. Drugs inhibited cell growth and induced apoptosis synergistically. The combination resulted in a decrease of cyclooxigenase-2, metalloproteinases-2 and -9 expression level and activity while PPARgamma, RXRgamma and tissue inhibitors of metalloproteinase-1 and -2 expression were increased. Finally, IIF potentiated PPAR transcriptional activity by enhancement of peroxisome proliferator response elements transactivation.
The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the ke... more The activation of the EGFR (epidermal growth factor receptor) signalling pathway is one of the key mechanisms underlying the development of resistance to tamoxifen in breast cancer patients. As EGCG [(-)-epigallocatechin-3-gallate], the most active catechin present in green tea, has been shown to down-regulate EGFR, we studied the effects of 10-100 μg/ml EGCG treatment on growth and invasion in a breast carcinoma cell line resistant to tamoxifen [MCF-7Tam (MCF-7 breast carcinoma cell line resistant to tamoxifen) cells] and parental MCF-7. A dose-dependent down-regulation of EGFR mRNA expression and protein level occurred after 50 μg/ml EGCG treatment of MCF-7Tam cells. EGFR molecules on the plasma membrane surface of MCF-7Tam cells significantly decreased. EGFR phosphorylation (Tyr-992, Tyr-1045 and Tyr-1068) was higher in MCF-7Tam than in MCF-7 and it was reduced by EGCG treatment. ERK (extracellular regulated kinase) and phospho-ERK p42/44 were also down-regulated by EGCG treatment and in vitro cell growth and invasion decreased. MMP-2 (matrix metalloproteinase-2) and MMP-9, which are implicated in cell invasion and metastasis, and EMMPRIN (extracellular matrix metalloproteinase inducer), a glycoprotein able to activate MMPs, were significantly reduced after 50 μg/ml EGCG treatment. In keeping with this, TIMP-1 (tissue inhibitor of metalloproteinases-1) and TIMP-2, which down-regulate MMPs, increased after EGCG treatment. Altogether, the present data demonstrated that EGCG could attenuate the tamoxifen-resistant phenotype of MCF-7Tam cells. EGCG could stop MCF-7Tam cell growth and in vitro invasion through down-regulation of EGFR and other molecules implicated in aggressive biological behaviour. The present data support the hypothesis that EGCG is an interesting molecule to be investigated in tamoxifen-resistant breast carcinoma.
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Papers by Alessio Papi