Papers by Elisa Giovannetti
Nucleosides Nucleotides & Nucleic Acids, 2011
Deoxycytidine kinase (dCK) is essential for phosphorylation of natural deoxynucleosides and analo... more Deoxycytidine kinase (dCK) is essential for phosphorylation of natural deoxynucleosides and analogs, such as gemcitabine and cytarabine, two widely used anticancer compounds. Regulation of dCK is complex, including Ser-74 phosphorylation. We hypothesized that dCK could be regulated by two additional mechanisms: micro-RNA (miRNA) and promoter methylation. Methylation-specific PCR (MSP) revealed methylation of the 3 ′ GC box in three out of six cancer cell lines. The 3 ′ GC box is located at the dCK promoter region. The methylation status was related to dCK mRNA expression. TargetScan and miRanda prediction algorithms revealed several possible miRNAs targeting dCK and identified miR-330 (micro-RNA 330) as the one conserved between the human, the chimpanzee, and the rhesus monkey genomes. Expression of miR-330 in various colon and lung cancer cell lines, as measured by QRT-PCR, varied five-fold between samples and correlated with in-vitro gemcitabine resistance (R = 0.82, p = 0.04). Exposure to gemcitabine also appeared to influence miR-330 levels in these cell lines. Furthermore, in our cell line panel, miR-330 expression negatively correlated with dCK mRNA expression (R = 0.74), suggesting a role of miR-330 in post-transcriptional regulation of dCK. In conclusion, the 3 ′ GC box and miR-330 may regulate dCK expression in cancer cells.
Expert review of anticancer therapy, Jan 4, 2016
In up to 5% of non-small cell lung cancer (NSCLC) patients, the EML4-ALK translocation drives tum... more In up to 5% of non-small cell lung cancer (NSCLC) patients, the EML4-ALK translocation drives tumor progression. Treatment with the ALK inhibitor crizotinib is more effective than standard chemotherapy. However, resistance to crizotinib occurs after approximately 8 months. Ceritinib is the first second-generation ALK inhibitor approved for treatment of crizotinib-resistant NSCLC. Ceritinib inhibits two of the most common ALK-mutants that confer resistance to crizotinib: L1196 M and G1269A. Cells with ALK expression are more sensitive to ceritinib than crizotinib (IC50 25 nM vs. 150 nM, respectively). Alternative second-generation ALK inhibitors such as Alectinib, Brigatinib and PF-06463922 are currently in development, each affecting different crizotinib-resistant ALK target mutations. Genetic identification of crizotinib-resistant mutants is essential for selecting the optimal treatment strategy in NSCLC patients to overcome resistance and to increase progression-free survival.
Clinical epigenetics, 2015
Primary pulmonary enteric adenocarcinoma (PEAC) is defined as a pulmonary adenocarcinoma with a p... more Primary pulmonary enteric adenocarcinoma (PEAC) is defined as a pulmonary adenocarcinoma with a predominant component of intestinal differentiation and tumor cells positive for at least one intestinal marker. The aim of the present study was the molecular and histological characterization of a PEAC from a patient with two other family members affected by similar lung tumors, which has never been reported before. We evaluated the molecular characteristics of the proband's PEAC by using a previously validated 47-microRNA (miRNA) cancer-specific array and a predictive method to estimate tissue-of-origin probabilities. Immunohistochemical (IHC) staining for thyroid transcription factor (TTF-1), napsin A, caudal-related homeobox 2 (CDX2), cytokeratins, and mucins, as well as mutational analyses for epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), and anaplastic lymphoma kinase (ALK) were performed on formalin-fixed, paraffin-embedded (FFPE) ...
Translational Oncogenomics, 2015
MET and its ligand HGF are involved in many biological processes, both physiological and patholog... more MET and its ligand HGF are involved in many biological processes, both physiological and pathological, making this signaling pathway an attractive therapeutic target in oncology. Downstream signaling effects are transmitted via mitogen-activated protein kinase (MAPK), PI3K (phosphoinositide 3-kinase protein kinase B)/AKT, signal transducer and activator of transcription proteins (STAT), and nuclear factor-κB. The final output of the terminal effector components of these pathways is activation of cytoplasmic and nuclear processes leading to increases in cell proliferation, survival, mobilization and invasive capacity. In addition to its role as an oncogenic driver, increasing evidence implicates MET as a common mechanism of resistance to targeted therapies including EGFR and VEGFR inhibitors. In the present review, we summarize the current knowledge on the role of the HGF-MET signaling pathway in cancer and its therapeutic targeting (HGF activation inhibitors, HGF inhibitors, MET antagonists and selective/nonselective MET kinase inhibitors). Recent advances in understanding the role of this pathway in the resistance to current anticancer strategies used in lung, kidney and pancreatic cancer are discussed.
Clinica Chimica Acta, 2004
Cancer Research, May 1, 2008
Expert Review of Molecular Diagnostics, 2015
There is an urgent need for novel and reliable biomarkers for the diagnosis and prognostication o... more There is an urgent need for novel and reliable biomarkers for the diagnosis and prognostication of pancreatic ductal adenocarcinoma (PDAC). Circulating microRNAs (miRNAs) have been extensively profiled in PDAC blood samples, but few studies have performed adequate validation of candidate markers. The evaluated study by Xu et al. investigated pre-operative plasma miRNAs from PDAC patients over three phases and three surgical centers. They revealed miR-486-5p and miR-938 were able to discriminate PDAC patients from healthy controls and those with chronic pancreatitis. The diagnostic ability of miR-486-5p for identifying PDAC from healthy controls was comparable to that of CA 19-9. This study provides further evidence for the use of blood-based miRNAs as diagnostic biomarkers in PDAC. However, as these have not been identified in previous studies these require further validation and methodology needs to be standardized if these are ever to be used in the clinic.
Oncotarget, Jan 19, 2015
Aminopeptidase inhibitors are receiving attention as combination chemotherapeutic agents for the ... more Aminopeptidase inhibitors are receiving attention as combination chemotherapeutic agents for the treatment of refractory acute myeloid leukemia. However, the factors determining therapeutic efficacy remain elusive. Here we identified the molecular basis of acquired resistance to CHR2863, an orally available hydrophobic aminopeptidase inhibitor prodrug with an esterase-sensitive motif, in myeloid leukemia cells. CHR2863 enters cells by diffusion and is retained therein upon esterase activity-mediated conversion to its hydrophilic active metabolite drug CHR6768, thereby exerting amino acid depletion. Carboxylesterases (CES) serve as candidate prodrug activating enzymes given CES1 expression in acute myeloid leukemia specimens. We established two novel myeloid leukemia sublines U937/CHR2863(200) and U937/CHR2863(5uM), with low (14-fold) and high level (270-fold) CHR2863 resistance. The latter drug resistant cells displayed: (i) complete loss of CES1-mediated drug activation associated ...
Expert opinion on investigational drugs, Jan 12, 2015
Receptor tyrosine kinases (RTKs) and their signaling pathways, control normal cellular processes;... more Receptor tyrosine kinases (RTKs) and their signaling pathways, control normal cellular processes; however, their deregulation play important roles in malignant transformation. In advanced non-small cell lung cancer (NSCLC), the recognition of oncogenic activation of specific RTKs, has led to the development of molecularly targeted agents that only benefit roughly 20% of patients. Entrectinib is a pan-TRK, ROS1 and ALK inhibitor that has shown potent anti-neoplastic activity and tolerability in various neoplastic conditions, particularly NSCLC. Areas covered: This review outlines the pharmacokinetics, pharmacodynamics, mechanism of action, safety, tolerability, pre-clinical studies and clinical trials of entrectinib, a promising novel agent for the treatment of advanced solid tumors with molecular alterations of Trk-A, B and C, ROS1 or ALK. Expert opinion: Among the several experimental drugs under clinical development, entrectinib is emerging as an innovative and promising targeted ...
Seminars in cancer biology, Jan 23, 2015
Autophagy is a highly dynamic, evolutionary conserved cellular homeostatic process that occurs at... more Autophagy is a highly dynamic, evolutionary conserved cellular homeostatic process that occurs at baseline levels in most cells. It exerts predominantly cytoprotective effects by removing damaged organelles and protein aggregates. In cancer, however, autophagy acts as both a tumor suppressor by preventing ROS-induced tumorigenesis and as a tumor inducer by providing nutrients to tumor cells under hypoxic, low-energy conditions and protecting them against therapeutically induced stress. Pancreatic Ductal Adenocarcinoma is an extremely lethal and aggressive neoplasm with a 5 year-survival rate between 1% and 5%. One of the most important factors affecting its poor prognosis is its high resistance to most of the existing chemotherapeutic regimens. The role of autophagy in PDAC has been investigated by different research groups and the results are quite divergent; some research lines point at autophagy as a tumor promoting mechanism, whereas other studies assign oncosuppressive function...
Oncotarget, Jan 7, 2015
Patients with primary HER2-positive breast cancer benefit from HER2-targeted therapies. Neverthel... more Patients with primary HER2-positive breast cancer benefit from HER2-targeted therapies. Nevertheless, a significant proportion of these patients die of disease progression due to mechanisms of drug resistance. MicroRNAs (miRNAs) are emerging as critical core regulators of drug resistance that act by modulating the epithelial-to-mesenchymal transition (EMT) and cancer-related immune responses. In this study, we investigated the association between the expression of a specific subset of 14 miRNAs involved in EMT processes and immune functions and the response to neoadjuvant trastuzumab and chemotherapy in 52 patients with HER2-overexpressing breast tumors. The expression of only a single miRNA, miR-21, was significantly associated with residual disease (p = 0.030) and increased after trastuzumab-chemotherapy (p = 0.012). A target prediction analysis coupled with in vitro and in vivo validations revealed that miR-21 levels inversely correlated with the expression of PTEN (rs = -0.502; ...
Critical reviews in oncogenesis
Non-small cell lung cancer (NSCLC) is one of the deadliest types of cancer. One explanation for t... more Non-small cell lung cancer (NSCLC) is one of the deadliest types of cancer. One explanation for this poor prognosis is the failure of most chemotherapeutic regimens, which prompted the development of new, rationally designed, targeted antitumor agents, such as inhibitors of the epidermal growth factor receptor (EGFR) and downstream pathways. However, most of these targeted therapies also fail, and studies on the mechanisms underlying resistance toward targeted agents might provide critical findings for NSCLC research and treatment. Some of these studies showed that drug resistance can emerge not only from genetic aberrations, but also from epigenetic changes, including regulation of different signaling pathways by microRNAs (miR-NAs), which act as key post-transcriptional regulators of gene expression. There is accumulating evidence that specific miRNAs correlated with drug sensitivity and can be used as prognostic markers in NSCLC. However, a greater knowledge of miRNAs might also provide novel insights in several drug-resistance mechanisms; hence, suggesting their potential in novel therapeutic interventions, by sensitizing tumor cells to drug-induced apoptosis as well as by inhibiting tumor proliferation and invasive capabilities. Therefore, this review highlights several recent and clinically relevant aspects of the regulation of drug resistance by miRNAs from the perspective of current anti-EGFR-targeted therapies in NSCLC.
Atlas of Genetics and Cytogenetics in Oncology and Haematology, 2013
Atlas of Genetics and Cytogenetics in Oncology and Haematology, 2014
Insights into phosphorylation-dependent mechanisms regulating USP1 protein stability during the c... more Insights into phosphorylation-dependent mechanisms regulating USP1 protein stability during the cell cycle. Dec 1. (REVIEW) PMID 22101265 USP1 deubiquitinates ID proteins to preserve a mesenchymal stem cell program in osteosarcoma.
PLoS ONE, 2013
Despite the initial response, all patients with epidermal growth factor receptor (EGFR)-mutant no... more Despite the initial response, all patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) eventually develop acquired resistance to EGFR tyrosine kinase inhibitors (TKIs). The EGFR-T790M secondary mutation is responsible for half of acquired resistance cases, while MET amplification has been associated with acquired resistance in about 5-15% of NSCLCs. Clinical findings indicate the retained addiction of resistant tumors on EGFR signaling. Therefore, we evaluated the molecular mechanisms supporting the therapeutic potential of gefitinib maintenance in the HCC827 GR5 NSCLC cell line harbouring MET amplification as acquired resistance mechanism. We demonstrated that resistant cells can proliferate and survive regardless of the presence of gefitinib, whereas the absence of the drug significantly enhanced cell migration and invasion. Moreover, the continuous exposure to gefitinib prevented the epithelial-mesenchymal transition (EMT) with increased E-cadherin expression and down-regulation of vimentin and N-cadherin. Importantly, the inhibition of cellular migration was correlated with the suppression of EGFR-dependent Src, STAT5 and p38 signaling as assessed by a specific kinase array, western blot analysis and silencing functional studies. On the contrary, the lack of effect of gefitinib on EGFR phosphorylation in the H1975 cells (EGFR-T790M) correlated with the absence of effects on cell migration and invasion. In conclusion, our findings suggest that certain EGFR-mutated patients may still benefit from a second-line therapy including gefitinib based on the specific mechanism underlying tumor cell resistance.
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Papers by Elisa Giovannetti