The aim of this study was to reconsider the biological characteristics of epithelioid malignant p... more The aim of this study was to reconsider the biological characteristics of epithelioid malignant peritoneal mesothelioma (E-MpM) in the light of new concepts about epithelial mesenchymal transition and mesenchymal epithelial reverse transition (EMT/MErT) and the role of epigenetic reprogramming in this context. To this end we profiled surgical specimens and derived cells cultures by a number of complementary approaches i.e. immunohistochemistry, immunofluorescence, in situ hybridization, biochemistry, pluripotent stem cell arrays, treatments with cytokines, growth factors and specific inhibitors.The analyses of the surgical specimens showed that i) EZH2 is expressed throughout the spectrum of MpM, ii) that E-MpM (including the high-grade undifferentiated form) are characterised by c-MYC and miRNA 17-5p expression, and iii) that progression to sarcomatoid MpM is dictated by EMT regulators. They also showed that E-MpM expressed c-MET and are enriched in E- and P-cadherins- and VEGFR2-expressing CSCs, thus strongly supporting a role for MErT reprogramming in endowing E-MpM tumour cells with stemness and plasticity, and hence with a drug resistant phenotype. The cell culture-based experiments confirmed the stemness traits and plasticity of E-MpM, and support the view that EZH2 is a druggable target in this tumor.
Organization of cancer cells into endothelial-like cell lined structures to support neovasculariz... more Organization of cancer cells into endothelial-like cell lined structures to support neovascularization and fuel solid tumors is a hallmark of progression and poor outcome. In triple negative breast cancer (TNBC), PDGFRβ has been identified as a key player of this process and is considered a promising target for breast cancer therapy. Thus, we aimed at investigating the role of microRNAs as therapeutic approach to inhibit PDGFRβ-mediated vasculogenic properties of TNBC, focusing on miR-9 and miR-200. In MDA-MB-231 and MDA-MB-157 TNBC cell lines, miR-9 and miR-200 promoted or inhibited, respectively, the formation of vascular-like structures in vitro. Induction of endogenous miR-9 expression, upon ligand-dependent stimulation of PDGFRβ signaling, promoted significant vascular-sprouting of TNBC cells in part by direct repression of STARD13. Conversely, ectopic expression of miR-200 inhibited this sprouting by indirectly reducing the protein levels of PDGFRβ through the direct suppressi...
Sunitinib improves the outcomes of patients with solitary fibrous tumours (SFTs). The aim of this... more Sunitinib improves the outcomes of patients with solitary fibrous tumours (SFTs). The aim of this study was to investigate and contextualise sunitinib-induced morpho-functional changes in order to gain insights into the drug's mechanism of action.To this end, four surgical specimens obtained from two sunitinib-responsive patients with malignant SFT, and one primary cell culture obtained from fresh tumoral tissue and its stabilised cell line, were studied by means of immunohistochemistry, bright field in situ hybridisation, immunofluorescence/confocal microscopy, and biochemistry.The post-sunitinib surgical samples were characterised by two biologically relevant morpho-functional changes: clear areas and necrotic foci. The first were associated with the attenuation/loss of PDGFRB expression and decreased mTOR signalling, and corresponded to a pathological response. The second were associated with the over-expression of PDGFRB and VEGFA, strong mTOR signalling activation, and the ...
A patient with metastatic BRAF-mutated colorectal cancer initially responded to combined EGFR and... more A patient with metastatic BRAF-mutated colorectal cancer initially responded to combined EGFR and BRAF inhibition with panitumumab plus vemurafenib. Pre-existing cells with increased MET gene copy number in the archival tumor tissue likely underwent clonal expansion during treatment, leading to the emergence of MET amplification in the re-biopsy taken at progression. In BRAF-mutated colorectal cancer cells, ectopic expression of MET conferred resistance to panitumumab and vemurafenib, which was overcome by combining BRAF and MET inhibition. Based on tumor genotyping and functional in vitro data, the patient was treated with the dual ALK-MET inhibitor crizotinib plus vemurafenib, thus switching to dual MET and BRAF blockade, with rapid and marked effectiveness of such strategy. Although acquired resistance is a major limitation to the clinical efficacy of anticancer agents, the identification of molecular targets emerging during the first treatment may afford the opportunity to desig...
Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is over-expresse... more Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is over-expressed in several human neoplastic cells. When MIF binds its receptor (CD74) and co-receptor (CD44), it initiates signaling cascades that orchestrate cell proliferation and survival, and it can directly modulate the activity of AMPK. These activities indicate that MIF potentially regulates cell survival and metabolism. We found that MIF was primarily co-expressed with CD74 in 16 out of 23 papillary thyroid carcinoma (PTC) and in all the 27 available anaplastic thyroid carcinoma (ATC) biopsy samples. MIF and CD74 were co-expressed in TPC-1 and HTC-C3 cell lines. The selective MIF inhibitor, 4-iodo-6-phenylpyrimidine (4-IPP), blocked MIF/CD74 internalization, activated JNK, and dose-dependently inhibited proliferation inducing apoptosis and mitotic cell death. In two CD74-negative cell lines, NIM-1 and K1, 4-IPP treatment partially reduced proliferation. Coordinated MIF and CD74 expression appeared to confer in tumor cells the plasticity necessary to escape cell cycle regulation, metabolic changes, and stress conditions. MIF/CD74 signaling removal made cells susceptible to apoptosis and mitotic cell death. This finding suggests a possible avenue for targeting DNA endoreduplication, thus preventing the proliferation of therapy-resistant cell subpopulations. This study highlights MIF/CD74 axis as an important player in the biology of aggressive thyroid neoplasms.
Background: The recognition of tumor infection by human papilloma virus (HPV) in oropharyngeal sq... more Background: The recognition of tumor infection by human papilloma virus (HPV) in oropharyngeal squamous-cell carcinoma (OSCC) is emerging as a valid biomarker to more accurate selection of patients for specific treatment, surveillance and tumor staging. To this aim, the HPV de- tection strategy in OSCC must dissect between HPV that is acting as a driver of malignant transfor- mation, and transcriptionally silent virus involved in productive infection. The aim of this study is to define the better method for the accurate identification of HPV status among OSCC. Patients and Methods: Thirty-six patients were selected for HPV status assessment combining dif- ferent methods, such as immunohistochemistry (IHC) for p16, in-situ hybridization (ISH) for high risk (HR)-HPV DNA and HR-HPV E6/E7 mRNA along with real-time PCR of HPV16 E6/E7 mRNA. All these cases were originally classified as HPV negative by DNA-based ISH but p16 positive by the IHC. Results: Twenty-six cases showed concordance ...
In this paper the Authors describe the main functions of microRNAs (miRNAs) along with well ackno... more In this paper the Authors describe the main functions of microRNAs (miRNAs) along with well acknowledged methods of their detection in biological materials. They include serum, plasma, urine, normal human samples and neoplastic tissues. The Authors also discusses about the relevance of bright field in situ hybridization (ISH) methods for miRNA detection in revealing the cells of origin of specific miRNAs. In particular, the paper highlights the automated ISH protocols for miRNA detection which have recently been proposed. These techniques will enable investigators to further explore the biological role of miRNAs.
MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression by binding to compleme... more MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression by binding to complementary sequences on target messenger RNA transcripts. In situ hybridisation (ISH) methods have been applied to the study of miRNA in tissue samples in order to understand which is the source of the miRNA of interest. In this paper, the authors describe a novel semi-automated bright field ISH method to visualise miRNAs in formalin fixed paraffin embedded tissue sections. The relevance of this work resides in the use of 3,3'-diaminobenzidine and peroxidase as the detection method, which provides a good defined deposition within tissues This method, which reveals the cells of origin of specific miRNAs, will enable investigators to further explore the biological role of miRNAs.
Human papillomavirus (HPV)-positive and HPV-negative oropharyngeal squamous cell carcinomas (OSCC... more Human papillomavirus (HPV)-positive and HPV-negative oropharyngeal squamous cell carcinomas (OSCCs) are two distinct entities. We defined the molecular profiles of druggable receptor tyrosine kinases (RTKs) in both groups. E5 expression and RTK alterations were studied in 17 HPV-positive and 59 HPV-negative formalin-fixed OSCCs. RTK activation was explored in further 12 frozen OSCCs. The HPV-positive OSCCs showed E5 expression and 33.3% expressed low level of HER2. The HPV-negative OSCCs showed HER2 expression (31.2%), increased HER2 gene copy number (46.51%, P = 0.045) and HER2 activation through HER2/EGFR heterodimerisation; HER3 (51.06%, P = 0.008) and neuregulin (65.63%; P = 0.03) expression, HER3 activation and HER3/EGFR heterodimerisation; and increased IGF-1R copy number (40.50%, P = 0.021), high IGF-1R cDNA values (P = 0.002), IGF-1R activation and expression of IGF1/2 and amphiregulin. PI3KCA mutations/expression/increased gene copy number and PTEN mutations were found in both groups, whereas PTEN gene loss was only observed in the HPV-positive cases. Human papillomavirus-positive and HPV-negative OSCC showed different RTK profiles. In HPV-positive cases, it would be interesting to study the expression of E5, which may modulate EGFR turnover and activate VEGF and PDGFRβ. In HPV-negative cases, HER3 may be a promising druggable biomarker that deserves further investigation. PI3KCA and PTEN alterations encourage the promising clinical evaluation of PI3K/mTOR inhibitor activity in OSCC, particularly in HPV-positive/PI3KCA-mutated OSCCs because they may be driven by PI3KCA mutation alone.
The aim of this study was to reconsider the biological characteristics of epithelioid malignant p... more The aim of this study was to reconsider the biological characteristics of epithelioid malignant peritoneal mesothelioma (E-MpM) in the light of new concepts about epithelial mesenchymal transition and mesenchymal epithelial reverse transition (EMT/MErT) and the role of epigenetic reprogramming in this context. To this end we profiled surgical specimens and derived cells cultures by a number of complementary approaches i.e. immunohistochemistry, immunofluorescence, in situ hybridization, biochemistry, pluripotent stem cell arrays, treatments with cytokines, growth factors and specific inhibitors.The analyses of the surgical specimens showed that i) EZH2 is expressed throughout the spectrum of MpM, ii) that E-MpM (including the high-grade undifferentiated form) are characterised by c-MYC and miRNA 17-5p expression, and iii) that progression to sarcomatoid MpM is dictated by EMT regulators. They also showed that E-MpM expressed c-MET and are enriched in E- and P-cadherins- and VEGFR2-expressing CSCs, thus strongly supporting a role for MErT reprogramming in endowing E-MpM tumour cells with stemness and plasticity, and hence with a drug resistant phenotype. The cell culture-based experiments confirmed the stemness traits and plasticity of E-MpM, and support the view that EZH2 is a druggable target in this tumor.
Organization of cancer cells into endothelial-like cell lined structures to support neovasculariz... more Organization of cancer cells into endothelial-like cell lined structures to support neovascularization and fuel solid tumors is a hallmark of progression and poor outcome. In triple negative breast cancer (TNBC), PDGFRβ has been identified as a key player of this process and is considered a promising target for breast cancer therapy. Thus, we aimed at investigating the role of microRNAs as therapeutic approach to inhibit PDGFRβ-mediated vasculogenic properties of TNBC, focusing on miR-9 and miR-200. In MDA-MB-231 and MDA-MB-157 TNBC cell lines, miR-9 and miR-200 promoted or inhibited, respectively, the formation of vascular-like structures in vitro. Induction of endogenous miR-9 expression, upon ligand-dependent stimulation of PDGFRβ signaling, promoted significant vascular-sprouting of TNBC cells in part by direct repression of STARD13. Conversely, ectopic expression of miR-200 inhibited this sprouting by indirectly reducing the protein levels of PDGFRβ through the direct suppressi...
Sunitinib improves the outcomes of patients with solitary fibrous tumours (SFTs). The aim of this... more Sunitinib improves the outcomes of patients with solitary fibrous tumours (SFTs). The aim of this study was to investigate and contextualise sunitinib-induced morpho-functional changes in order to gain insights into the drug's mechanism of action.To this end, four surgical specimens obtained from two sunitinib-responsive patients with malignant SFT, and one primary cell culture obtained from fresh tumoral tissue and its stabilised cell line, were studied by means of immunohistochemistry, bright field in situ hybridisation, immunofluorescence/confocal microscopy, and biochemistry.The post-sunitinib surgical samples were characterised by two biologically relevant morpho-functional changes: clear areas and necrotic foci. The first were associated with the attenuation/loss of PDGFRB expression and decreased mTOR signalling, and corresponded to a pathological response. The second were associated with the over-expression of PDGFRB and VEGFA, strong mTOR signalling activation, and the ...
A patient with metastatic BRAF-mutated colorectal cancer initially responded to combined EGFR and... more A patient with metastatic BRAF-mutated colorectal cancer initially responded to combined EGFR and BRAF inhibition with panitumumab plus vemurafenib. Pre-existing cells with increased MET gene copy number in the archival tumor tissue likely underwent clonal expansion during treatment, leading to the emergence of MET amplification in the re-biopsy taken at progression. In BRAF-mutated colorectal cancer cells, ectopic expression of MET conferred resistance to panitumumab and vemurafenib, which was overcome by combining BRAF and MET inhibition. Based on tumor genotyping and functional in vitro data, the patient was treated with the dual ALK-MET inhibitor crizotinib plus vemurafenib, thus switching to dual MET and BRAF blockade, with rapid and marked effectiveness of such strategy. Although acquired resistance is a major limitation to the clinical efficacy of anticancer agents, the identification of molecular targets emerging during the first treatment may afford the opportunity to desig...
Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is over-expresse... more Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is over-expressed in several human neoplastic cells. When MIF binds its receptor (CD74) and co-receptor (CD44), it initiates signaling cascades that orchestrate cell proliferation and survival, and it can directly modulate the activity of AMPK. These activities indicate that MIF potentially regulates cell survival and metabolism. We found that MIF was primarily co-expressed with CD74 in 16 out of 23 papillary thyroid carcinoma (PTC) and in all the 27 available anaplastic thyroid carcinoma (ATC) biopsy samples. MIF and CD74 were co-expressed in TPC-1 and HTC-C3 cell lines. The selective MIF inhibitor, 4-iodo-6-phenylpyrimidine (4-IPP), blocked MIF/CD74 internalization, activated JNK, and dose-dependently inhibited proliferation inducing apoptosis and mitotic cell death. In two CD74-negative cell lines, NIM-1 and K1, 4-IPP treatment partially reduced proliferation. Coordinated MIF and CD74 expression appeared to confer in tumor cells the plasticity necessary to escape cell cycle regulation, metabolic changes, and stress conditions. MIF/CD74 signaling removal made cells susceptible to apoptosis and mitotic cell death. This finding suggests a possible avenue for targeting DNA endoreduplication, thus preventing the proliferation of therapy-resistant cell subpopulations. This study highlights MIF/CD74 axis as an important player in the biology of aggressive thyroid neoplasms.
Background: The recognition of tumor infection by human papilloma virus (HPV) in oropharyngeal sq... more Background: The recognition of tumor infection by human papilloma virus (HPV) in oropharyngeal squamous-cell carcinoma (OSCC) is emerging as a valid biomarker to more accurate selection of patients for specific treatment, surveillance and tumor staging. To this aim, the HPV de- tection strategy in OSCC must dissect between HPV that is acting as a driver of malignant transfor- mation, and transcriptionally silent virus involved in productive infection. The aim of this study is to define the better method for the accurate identification of HPV status among OSCC. Patients and Methods: Thirty-six patients were selected for HPV status assessment combining dif- ferent methods, such as immunohistochemistry (IHC) for p16, in-situ hybridization (ISH) for high risk (HR)-HPV DNA and HR-HPV E6/E7 mRNA along with real-time PCR of HPV16 E6/E7 mRNA. All these cases were originally classified as HPV negative by DNA-based ISH but p16 positive by the IHC. Results: Twenty-six cases showed concordance ...
In this paper the Authors describe the main functions of microRNAs (miRNAs) along with well ackno... more In this paper the Authors describe the main functions of microRNAs (miRNAs) along with well acknowledged methods of their detection in biological materials. They include serum, plasma, urine, normal human samples and neoplastic tissues. The Authors also discusses about the relevance of bright field in situ hybridization (ISH) methods for miRNA detection in revealing the cells of origin of specific miRNAs. In particular, the paper highlights the automated ISH protocols for miRNA detection which have recently been proposed. These techniques will enable investigators to further explore the biological role of miRNAs.
MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression by binding to compleme... more MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression by binding to complementary sequences on target messenger RNA transcripts. In situ hybridisation (ISH) methods have been applied to the study of miRNA in tissue samples in order to understand which is the source of the miRNA of interest. In this paper, the authors describe a novel semi-automated bright field ISH method to visualise miRNAs in formalin fixed paraffin embedded tissue sections. The relevance of this work resides in the use of 3,3'-diaminobenzidine and peroxidase as the detection method, which provides a good defined deposition within tissues This method, which reveals the cells of origin of specific miRNAs, will enable investigators to further explore the biological role of miRNAs.
Human papillomavirus (HPV)-positive and HPV-negative oropharyngeal squamous cell carcinomas (OSCC... more Human papillomavirus (HPV)-positive and HPV-negative oropharyngeal squamous cell carcinomas (OSCCs) are two distinct entities. We defined the molecular profiles of druggable receptor tyrosine kinases (RTKs) in both groups. E5 expression and RTK alterations were studied in 17 HPV-positive and 59 HPV-negative formalin-fixed OSCCs. RTK activation was explored in further 12 frozen OSCCs. The HPV-positive OSCCs showed E5 expression and 33.3% expressed low level of HER2. The HPV-negative OSCCs showed HER2 expression (31.2%), increased HER2 gene copy number (46.51%, P = 0.045) and HER2 activation through HER2/EGFR heterodimerisation; HER3 (51.06%, P = 0.008) and neuregulin (65.63%; P = 0.03) expression, HER3 activation and HER3/EGFR heterodimerisation; and increased IGF-1R copy number (40.50%, P = 0.021), high IGF-1R cDNA values (P = 0.002), IGF-1R activation and expression of IGF1/2 and amphiregulin. PI3KCA mutations/expression/increased gene copy number and PTEN mutations were found in both groups, whereas PTEN gene loss was only observed in the HPV-positive cases. Human papillomavirus-positive and HPV-negative OSCC showed different RTK profiles. In HPV-positive cases, it would be interesting to study the expression of E5, which may modulate EGFR turnover and activate VEGF and PDGFRβ. In HPV-negative cases, HER3 may be a promising druggable biomarker that deserves further investigation. PI3KCA and PTEN alterations encourage the promising clinical evaluation of PI3K/mTOR inhibitor activity in OSCC, particularly in HPV-positive/PI3KCA-mutated OSCCs because they may be driven by PI3KCA mutation alone.
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