16 results on '"Foggetti G"'
Search Results
2. EP08.02-125 Tumor Suppressor Gene Alterations Identified at Disease Progression Impact Outcomes in Patients with EGFR-mutant Lung Cancer
- Author
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Stockhammer, P., primary, Grant, M., additional, Wurtz, A., additional, Foggetti, G., additional, Chung, S., additional, Li, F., additional, Gettinger, S., additional, Politi, K., additional, and Goldberg, S., additional
- Published
- 2022
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3. Transactivation specificity is conserved among p53 family proteins and depends on a response element sequence code
- Author
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Ciribilli, Y., primary, Monti, P., additional, Bisio, A., additional, Nguyen, H. T., additional, Ethayathulla, A. S., additional, Ramos, A., additional, Foggetti, G., additional, Menichini, P., additional, Menendez, D., additional, Resnick, M. A., additional, Viadiu, H., additional, Fronza, G., additional, and Inga, A., additional
- Published
- 2013
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4. From Tumor Macroenvironment to Tumor Microenvironment: The Prognostic Role of the Immune System in Oral and Lung Squamous Cell Carcinoma.
- Author
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Battista RA, Pini GM, Finco A, Corso F, Galli A, Arrigoni G, Doglioni C, Callea M, Paccagnella M, Porcu L, Filipello F, Mazzola M, Foggetti G, Gregorc V, Giordano L, Bussi M, Mirabile A, and Veronesi G
- Abstract
Background: The interplay between cancer cells and the immune system is crucial in cancer progression and treatment. In this regard, the tumor immune microenvironment and macroenvironment, marked by systemic inflammation markers and TILs, could be considered key prognostic factors in tumors, including oral and lung squamous cell carcinoma., Methods: We conducted a retrospective clinical study on patients with Oral Squamous Cell Carcinoma (OSCC) and Lung Squamous Cell Carcinoma (LUSCC), examining stages, comorbidities, treatments, and outcomes. We evaluated the prognostic significance of pre-surgical systemic inflammation markers and tumor microenvironment composition., Results: Associations were found between systemic inflammation markers-NLR, MLR, and PLR-and tumor microenvironment factors, such as TILs and CD8+ cell prevalence-elevated inflammation markers correlated with advanced stages. Specifically, NLR was prognostic in OSCC, whereas PLR was prognostic in LUSCC. Using a cutoff value, we divided our tumor samples into two prognostic groups. Moreover, TILs levels >15% of tumor stroma correlated with prolonged overall survival in both OSCC and LUSCC, while increased CD8+ expression was linked to extended disease-free survival in LUSCC., Discussion: Systemic inflammation markers and TILs can be valuable prognostic factors of survival, highlighting the immune response's role in OSCC and LUSCC. Despite limited clinical integration of the presented cohorts due to a lack of standardization, we concluded that analyzing tumor immune profiles may offer novel prognostic insights., Conclusions: Future integration into cancer classification could improve risk stratification and treatment guidance.
- Published
- 2024
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5. Co-Occurring Alterations in Multiple Tumor Suppressor Genes Are Associated With Worse Outcomes in Patients With EGFR-Mutant Lung Cancer.
- Author
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Stockhammer P, Grant M, Wurtz A, Foggetti G, Expósito F, Gu J, Zhao H, Choi J, Chung S, Li F, Walther Z, Dietz J, Duffield E, Gettinger S, Politi K, and Goldberg SB
- Subjects
- Humans, Protein Kinase Inhibitors therapeutic use, ErbB Receptors, Genes, Tumor Suppressor, Mutation, Lung Neoplasms drug therapy, Lung Neoplasms genetics, Lung Neoplasms pathology, Carcinoma, Non-Small-Cell Lung drug therapy, Carcinoma, Non-Small-Cell Lung genetics, Carcinoma, Non-Small-Cell Lung pathology, Acrylamides, Aniline Compounds, Indoles, Pyrimidines
- Abstract
Introduction: Patients with metastatic EGFR-mutant NSCLC inevitably have disease progression while on tyrosine kinase inhibitor (TKI) therapy. Co-occurring tumor suppressor gene (TSG) alterations have been associated with poor outcomes, however, detailed analyses of their impact on patient outcomes are limited., Methods: Patients with EGFR-mutant NSCLC treated with EGFR TKIs who had tumor genomic profiling were included. Alterations in TP53 and five additional TSGs (RB1, NF1, ARID1A, BRCA1, and PTEN) were used to stratify the cohort into the following three subgroups: patients with tumors harboring a TP53 mutation plus a mutation in at least one additional TSG (TP53
mut /TSGmut ), those having a TP53 mutation without additional TSG mutations (TP53mut /TSGwt ), and those with TP53wt . Patient characteristics and clinical outcomes were assessed in two independent cohorts., Results: A total of 101 patients from the Yale Cancer Center and 182 patients from the American Association for Cancer Research Project GENIE database were included. In the Yale cohort, TP53 mutations were identified in 65 cases (64%), of which 23 were TP53mut /TSGmut and 42 were TP53mut /TSGwt . Although the presence of a TP53 mutation was associated with worse outcomes, the additional TSG alteration in TP53mut tumors identified a subset of patients associated with particularly aggressive disease and inferior clinical outcome in both the Yale and the GENIE cohorts. Specifically, in the Yale cohort for patients receiving first-line TKIs, those with TP53mut /TSGmut tumors had shorter progression-free survival (PFS) and overall survival (OS) than TP53mut /TSGwt (PFS: hazard ratio [HR] = 2.03, confidence interval [CI]: 1.12-3.69, p < 0.01, OS: HR = 1.58, CI: 0.82-3.04, p = 0.12) or TP53wt cases (PFS: HR 2.4, CI: 1.28-4.47, p < 0.001, OS: HR = 2.54, CI: 1.21-5.34, p < 0.005). Inferior outcomes in patients with TP53mut /TSGmut tumors were also found in those receiving osimertinib as second-line therapy. Similar findings were seen in patients in the GENIE cohort., Conclusions: Patients with TP53mut /TSGmut tumors represent a patient subgroup characterized by an aggressive disease phenotype and inferior outcomes on EGFR TKIs. This information is important for understanding the biological underpinnings of differential outcomes with TKI treatment and has implications for identifying patients who may benefit from additional therapeutic interventions beyond osimertinib monotherapy., (Copyright © 2023 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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6. Patient-Derived Models of Cancer in the NCI PDMC Consortium: Selection, Pitfalls, and Practical Recommendations.
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Habowski AN, Budagavi DP, Scherer SD, Aurora AB, Caligiuri G, Flynn WF, Langer EM, Brody JR, Sears RC, Foggetti G, Arnal Estape A, Nguyen DX, Politi KA, Shen X, Hsu DS, Peehl DM, Kurhanewicz J, Sriram R, Suarez M, Xiao S, Du Y, Li XN, Navone NM, Labanca E, and Willey CD
- Abstract
For over a century, early researchers sought to study biological organisms in a laboratory setting, leading to the generation of both in vitro and in vivo model systems. Patient-derived models of cancer (PDMCs) have more recently come to the forefront of preclinical cancer models and are even finding their way into clinical practice as part of functional precision medicine programs. The PDMC Consortium, supported by the Division of Cancer Biology in the National Cancer Institute of the National Institutes of Health, seeks to understand the biological principles that govern the various PDMC behaviors, particularly in response to perturbagens, such as cancer therapeutics. Based on collective experience from the consortium groups, we provide insight regarding PDMCs established both in vitro and in vivo, with a focus on practical matters related to developing and maintaining key cancer models through a series of vignettes. Although every model has the potential to offer valuable insights, the choice of the right model should be guided by the research question. However, recognizing the inherent constraints in each model is crucial. Our objective here is to delineate the strengths and limitations of each model as established by individual vignettes. Further advances in PDMCs and the development of novel model systems will enable us to better understand human biology and improve the study of human pathology in the lab.
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- 2024
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7. Oncogenic context shapes the fitness landscape of tumor suppression.
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Blair LM, Juan JM, Sebastian L, Tran VB, Nie W, Wall GD, Gerceker M, Lai IK, Apilado EA, Grenot G, Amar D, Foggetti G, Do Carmo M, Ugur Z, Deng D, Chenchik A, Paz Zafra M, Dow LE, Politi K, MacQuitty JJ, Petrov DA, Winslow MM, Rosen MJ, and Winters IP
- Subjects
- Mice, Humans, Animals, Oncogenes genetics, Carcinogenesis genetics, Cell Transformation, Neoplastic genetics, Mutation, Proto-Oncogene Proteins p21(ras) genetics, Lung Neoplasms genetics, Lung Neoplasms pathology
- Abstract
Tumors acquire alterations in oncogenes and tumor suppressor genes in an adaptive walk through the fitness landscape of tumorigenesis. However, the interactions between oncogenes and tumor suppressor genes that shape this landscape remain poorly resolved and cannot be revealed by human cancer genomics alone. Here, we use a multiplexed, autochthonous mouse platform to model and quantify the initiation and growth of more than one hundred genotypes of lung tumors across four oncogenic contexts: KRAS G12D, KRAS G12C, BRAF V600E, and EGFR L858R. We show that the fitness landscape is rugged-the effect of tumor suppressor inactivation often switches between beneficial and deleterious depending on the oncogenic context-and shows no evidence of diminishing-returns epistasis within variants of the same oncogene. These findings argue against a simple linear signaling relationship amongst these three oncogenes and imply a critical role for off-axis signaling in determining the fitness effects of inactivating tumor suppressors., (© 2023. Springer Nature Limited.)
- Published
- 2023
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8. PTEN Loss Confers Resistance to Anti-PD-1 Therapy in Non-Small Cell Lung Cancer by Increasing Tumor Infiltration of Regulatory T Cells.
- Author
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Exposito F, Redrado M, Houry M, Hastings K, Molero-Abraham M, Lozano T, Solorzano JL, Sanz-Ortega J, Adradas V, Amat R, Redin E, Leon S, Legarra N, Garcia J, Serrano D, Valencia K, Robles-Oteiza C, Foggetti G, Otegui N, Felip E, Lasarte JJ, Paz-Ares L, Zugazagoitia J, Politi K, Montuenga L, and Calvo A
- Subjects
- Animals, Humans, Mice, B7-H1 Antigen metabolism, Immunotherapy methods, Phosphatidylinositol 3-Kinases metabolism, Tumor Microenvironment, Immune Checkpoint Inhibitors pharmacology, Immune Checkpoint Inhibitors therapeutic use, Carcinoma, Non-Small-Cell Lung drug therapy, Carcinoma, Non-Small-Cell Lung genetics, Carcinoma, Non-Small-Cell Lung metabolism, Carcinoma, Squamous Cell drug therapy, Carcinoma, Squamous Cell genetics, Carcinoma, Squamous Cell metabolism, Lung Neoplasms drug therapy, Lung Neoplasms genetics, Lung Neoplasms metabolism, PTEN Phosphohydrolase genetics, PTEN Phosphohydrolase metabolism, T-Lymphocytes, Regulatory, Drug Resistance, Neoplasm genetics
- Abstract
Immunotherapy resistance in non-small cell lung cancer (NSCLC) may be mediated by an immunosuppressive microenvironment, which can be shaped by the mutational landscape of the tumor. Here, we observed genetic alterations in the PTEN/PI3K/AKT/mTOR pathway and/or loss of PTEN expression in >25% of patients with NSCLC, with higher frequency in lung squamous carcinomas (LUSC). Patients with PTEN-low tumors had higher levels of PD-L1 and PD-L2 and showed worse progression-free survival when treated with immunotherapy. Development of a Pten-null LUSC mouse model revealed that tumors with PTEN loss were refractory to antiprogrammed cell death protein 1 (anti-PD-1), highly metastatic and fibrotic, and secreted TGFβ/CXCL10 to promote conversion of CD4+ lymphocytes into regulatory T cells (Treg). Human and mouse PTEN-low tumors were enriched in Tregs and expressed higher levels of immunosuppressive genes. Importantly, treatment of mice bearing Pten-null tumors with TLR agonists and anti-TGFβ antibody aimed to alter this immunosuppressive microenvironment and led to tumor rejection and immunologic memory in 100% of mice. These results demonstrate that lack of PTEN causes immunotherapy resistance in LUSCs by establishing an immunosuppressive tumor microenvironment that can be reversed therapeutically., Significance: PTEN loss leads to the development of an immunosuppressive microenvironment in lung cancer that confers resistance to anti-PD-1 therapy, which can be overcome by targeting PTEN loss-mediated immunosuppression., (©2023 American Association for Cancer Research.)
- Published
- 2023
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9. Mutant p53 K120R expression enables a partial capacity to modulate metabolism.
- Author
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Monti P, Ravera S, Speciale A, Velkova I, Foggetti G, Degan P, Fronza G, and Menichini P
- Abstract
The TP53 tumor suppressor gene is one of the most studied gene in virtue of its ability to prevent cancer development by regulating apoptosis, cell cycle arrest, DNA repair, autophagy and senescence. Furthermore, the modulation of metabolism by P53 is fundamental for tumor suppressor activity. Studies in mouse models showed that mice carrying TP53 mutations affecting the acetylation in the DNA binding domain still retain the ability to transactivate genes involved in metabolism. Noteworthy, mice expressing the triple 3KR or the single K117R mutant do not show early on-set tumor development in contrast to TP53
-/- mice. Interestingly, the mouse K117R mutation corresponds to the human tumor-derived K120R modification, which abrogates P53-dependent activation of apoptosis without affecting growth arrest. In this study, we investigated the property of the human P53 K120R mutant in the regulation of metabolism by analyzing the transcriptional specificity in yeast- and mammalian-based reporter assays, the metabolic phenotype associated to its expression in colon cancer HCT116TP53 -/- cells and the induction of P53 targets and proteins involved in the antioxidant response. These properties were analyzed in comparison to wild type P53 protein, the human triple mutant corresponding to mouse 3KR and the cancer hot-spot R273H mutant. We confirm the selective functionality of P53 K120R mutant, which shows a transcriptional activity on cell cycle arrest but not on apoptotic targets. Interestingly, this mutant shows a partial transactivation activity on p53 response element belonging to the metabolic target TIGAR. Moreover, we observe a significant uncoupling between oxygen consumption and ATP production associated with higher lipid peroxidation level in all P53 mutants carrying cells with respect to wild type P53 expressing cells. Noteworthy, in the absence of a pro-oxidative challenge, cells expressing K120R mutant retain a partial capacity to modulate glucose metabolism, limiting lipid peroxidation with respect to the other P53 mutants carrying cells. Lastly, especially in presence of human 3KR mutant, a high expression of proteins involved in the antioxidant response is found. However, this response does not avoid the increased lipid peroxidation, confirming that only wild type P53 is able to completely counteract the oxidative stress and relative damages., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Monti, Ravera, Speciale, Velkova, Foggetti, Degan, Fronza and Menichini.)- Published
- 2022
- Full Text
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10. Tumor suppressor pathways shape EGFR-driven lung tumor progression and response to treatment.
- Author
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Foggetti G, Li C, Cai H, Petrov DA, Winslow MM, and Politi K
- Abstract
In vivo modeling combined with CRISPR/Cas9-mediated somatic genome editing has contributed to elucidating the functional importance of specific genetic alterations in human tumors. Our recent work uncovered tumor suppressor pathways that affect EGFR-driven lung tumor growth and sensitivity to tyrosine kinase inhibitors and reflect the mutational landscape and treatment outcomes in the human disease., Competing Interests: K.P. is a co-inventor on a patent licensed to Molecular MD for EGFR T790M mutation testing (through MSKCC). K.P. has received Honoraria/Consulting fees from Takeda, NCCN, Novartis, Merck, AstraZeneca, Tocagen, Maverick Therapeutics and Dynamo Therapeutics and research support from AstraZeneca, D2G Oncology, Kolltan, Roche, Symphogen and Boehringer-Ingelheim. M.M.W. has received honoraria from Genentech, Merck, and Amgen. M.M.W. and D.A.P. have ownership interest in, and are founders, consultants, and advisory board members for, D2G Oncology Inc., (© 2022 Taylor & Francis Group, LLC.)
- Published
- 2022
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11. Preclinical Models for the Study of Lung Cancer Pathogenesis and Therapy Development.
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Arnal-Estapé A, Foggetti G, Starrett JH, Nguyen DX, and Politi K
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- Animals, Disease Models, Animal, Humans, Mice, Organoids, Translational Research, Biomedical, Lung Neoplasms etiology, Lung Neoplasms therapy
- Abstract
Experimental preclinical models have been a cornerstone of lung cancer translational research. Work in these model systems has provided insights into the biology of lung cancer subtypes and their origins, contributed to our understanding of the mechanisms that underlie tumor progression, and revealed new therapeutic vulnerabilities. Initially patient-derived lung cancer cell lines were the main preclinical models available. The landscape is very different now with numerous preclinical models for research each with unique characteristics. These include genetically engineered mouse models (GEMMs), patient-derived xenografts (PDXs) and three-dimensional culture systems ("organoid" cultures). Here we review the development and applications of these models and describe their contributions to lung cancer research., (Copyright © 2021 Cold Spring Harbor Laboratory Press; all rights reserved.)
- Published
- 2021
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12. P63 modulates the expression of the WDFY2 gene which is implicated in cancer regulation and limb development.
- Author
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Monti P, Ciribilli Y, Foggetti G, Menichini P, Bisio A, Cappato S, Inga A, Divizia MT, Lerone M, Bocciardi R, and Fronza G
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- DNA-Binding Proteins genetics, Gene Expression Regulation, Neoplastic genetics, Humans, Neoplasms pathology, Protein Isoforms genetics, Response Elements genetics, Signal Transduction genetics, Transcriptional Activation genetics, Tumor Suppressor Protein p53 genetics, Carcinogenesis genetics, Intracellular Signaling Peptides and Proteins genetics, Neoplasms genetics, Transcription Factors genetics, Tumor Suppressor Proteins genetics
- Abstract
TP63 is a member of the TP53 gene family, sharing a common gene structure that produces two groups of mRNAs' encoding proteins with different N-terminal regions (ΔN and TA isoforms); both transcripts are also subjected to alternative splicing mechanisms at C-terminus, generating a variety of isoforms. p63 is a master regulator of epidermal development and homoeostasis as well as an important player in tumorigenesis and cancer progression with both oncogenic and tumour suppressive roles. A number of studies have aimed at the identification of p63 target genes, allowing the dissection of the molecular pathways orchestrated by the different isoforms. In the present study we investigated in more detail the p63 responsiveness of the WDFY2 (WD repeat and FYVE domain containing 2) gene, encoding for an endosomal protein identified as a binding partner of the PI-3K/AKT signalling pathway. We showed that overexpression of different p63 isoforms was able to induce WDFY2 expression in TP53-null cells. The p63-dependent transcriptional activation was associated with specific response elements (REs) that have been identified by a bioinformatics tool and validated by yeast- and mammal-based assays. Interestingly, to confirm that WDFY2 belongs to the p63 network of cancer regulation, we analysed the impact of WDFY2 alterations, by showing its frequent deletion in different types of tumours and suggesting its expression level as a prognostic biomarker. Lastly, we identified a chromosomal translocation involving the WDFY2 locus in a patient affected by a rare congenital limb anomaly, indicating WDFY2 as a possible susceptibility gene placed downstream p63 in the network of limb development., (© 2019 The Author(s).)
- Published
- 2019
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13. Autophagy induced by SAHA affects mutant P53 degradation and cancer cell survival.
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Foggetti G, Ottaggio L, Russo D, Mazzitelli C, Monti P, Degan P, Miele M, Fronza G, and Menichini P
- Subjects
- Apoptosis drug effects, Breast Neoplasms genetics, Cell Line, Tumor, Cell Survival drug effects, Female, Histone Deacetylase Inhibitors pharmacology, Humans, Mutation, Proteolysis drug effects, Antineoplastic Agents pharmacology, Autophagy drug effects, Breast Neoplasms drug therapy, Tumor Suppressor Protein p53 genetics, Vorinostat pharmacology
- Abstract
Missense mutations in the TP53 gene produce mutant p53 (mutp53) proteins which may acquire oncogenic properties favoring chemoresistance, cell migration, and metastasis. The exploitation of cellular pathways that promote mutp53 degradation may reduce cell proliferation and invasion as well as increase the sensitivity to anticancer drugs, with a strong impact on current cancer therapies. In the last years, several molecules have been characterized for their ability to induce the degradation of mutp53 through the activation of autophagy. Here, we investigated the correlation between autophagy and mutp53 degradation induced by suberoylanilide hydroxamic acid (SAHA), an FDA-approved histone deacetylase inhibitor. In the human cancer lines MDA-MB-231 (mutp53-R280K) and DLD1 (mutp53-S241F), SAHA induced a significant mutp53 degradation. However, such degradation correlated with autophagy induction only in MDA-MB-231 cells, being counteracted by autophagy inhibition, which also increased SAHA-induced cell death. Conversely, in DLD1 cells SAHA triggered a low level of autophagy despite promoting a strong decrease in mutp53 level, and autophagy inhibition did not change either mutp53 levels or sensitivity to this drug. We conclude that autophagy can be a relevant pathway for mutp53 degradation induced by SAHA, but its contribution to mutp53 destabilization and the consequences on cell death are likely context-dependent., (© 2019 The Author(s).)
- Published
- 2019
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14. Etoposide-resistance in a neuroblastoma model cell line is associated with 13q14.3 mono-allelic deletion and miRNA-15a/16-1 down-regulation.
- Author
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Marengo B, Monti P, Miele M, Menichini P, Ottaggio L, Foggetti G, Pulliero A, Izzotti A, Speciale A, Garbarino O, Traverso N, Fronza G, and Domenicotti C
- Subjects
- Apoptosis drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Drug Resistance, Neoplasm drug effects, Drug Resistance, Neoplasm genetics, Gene Expression Regulation, Neoplastic drug effects, Humans, N-Myc Proto-Oncogene Protein genetics, Neuroblastoma genetics, Neuroblastoma pathology, Etoposide pharmacology, MicroRNAs genetics, Neuroblastoma drug therapy, Tumor Suppressor Protein p53 genetics
- Abstract
Drug resistance is the major obstacle in successfully treating high-risk neuroblastoma. The aim of this study was to investigate the basis of etoposide-resistance in neuroblastoma. To this end, a MYCN-amplified neuroblastoma cell line (HTLA-230) was treated with increasing etoposide concentrations and an etoposide-resistant cell line (HTLA-ER) was obtained. HTLA-ER cells, following etoposide exposure, evaded apoptosis by altering Bax/Bcl2 ratio. While both cell populations shared a homozygous TP53 mutation encoding a partially-functioning protein, a mono-allelic deletion of 13q14.3 locus, where the P53 inducible miRNAs 15a/16-1 are located, and the consequent miRNA down-regulation were detected only in HTLA-ER cells. This event correlated with BMI-1 oncoprotein up-regulation which caused a decrease in p16 tumor suppressor content and a metabolic adaptation of HTLA-ER cells. These results, taken collectively, highlight the role of miRNAs 15a/16-1 as markers of chemoresistance.
- Published
- 2018
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15. Gambogic acid counteracts mutant p53 stability by inducing autophagy.
- Author
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Foggetti G, Ottaggio L, Russo D, Monti P, Degan P, Fronza G, and Menichini P
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- Apoptosis drug effects, Cell Line, Tumor, Humans, Tumor Suppressor Protein p53 genetics, Autophagy drug effects, Mutation, Protein Stability drug effects, Tumor Suppressor Protein p53 metabolism, Xanthones pharmacology
- Abstract
Mutant p53 (mutp53) proteins are frequently present at higher levels than the wild-type (wt) protein in tumors, and some of them can acquire oncogenic properties. Consistently, knockdown of mutp53 protein in human cancer cell lines leads to reduced cell proliferation and invasion as well as to an increased sensitivity to some anticancer drugs. Therefore, the exploitation of cellular pathways and/or molecules that promote mutp53 degradation may have a therapeutic interest. Recently, autophagy is emerging as an important pathway involved in the stability of mutp53. In this paper, we explored the autophagic potential of gambogic acid (GA), a molecule that stimulates the degradation of mutp53 and increases the sensitivity of cancer cells to chemotherapeutic agents. We demonstrated that GA may induce mutp53 degradation through autophagy in cancer cells expressing the p53-R280K (MDA-MB-231) and the p53-S241F (DLD1) proteins. The inhibition of autophagy with bafilomycin A1 or chloroquine counteracted mutp53 degradation by GA. However, the autophagy induction and mutp53 degradation affected cell survival and proliferation only at low GA concentrations. At higher GA concentrations, when cells undergo massive apoptosis, autophagy is no longer detectable by immuno-fluorescence analysis. We concluded that autophagy is a relevant pathway for mutp53 degradation in cancer cells but it contributes only partially to GA-induced cell death, in a time and dose-dependent manner., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2017
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16. ∆N-P63α and TA-P63α exhibit intrinsic differences in transactivation specificities that depend on distinct features of DNA target sites.
- Author
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Monti P, Ciribilli Y, Bisio A, Foggetti G, Raimondi I, Campomenosi P, Menichini P, Fronza G, and Inga A
- Subjects
- Blotting, Western, DNA-Binding Proteins metabolism, HCT116 Cells, Humans, Polymerase Chain Reaction, Protein Isoforms metabolism, Response Elements physiology, Transfection, DNA chemistry, DNA metabolism, Transcription Factors metabolism, Transcriptional Activation physiology, Tumor Suppressor Proteins metabolism
- Abstract
TP63 is a member of the TP53 gene family that encodes for up to ten different TA and ∆N isoforms through alternative promoter usage and alternative splicing. Besides being a master regulator of gene expression for squamous epithelial proliferation, differentiation and maintenance, P63, through differential expression of its isoforms, plays important roles in tumorigenesis. All P63 isoforms share an immunoglobulin-like folded DNA binding domain responsible for binding to sequence-specific response elements (REs), whose overall consensus sequence is similar to that of the canonical p53 RE. Using a defined assay in yeast, where P63 isoforms and RE sequences are the only variables, and gene expression assays in human cell lines, we demonstrated that human TA- and ∆N-P63α proteins exhibited differences in transactivation specificity not observed with the corresponding P73 or P53 protein isoforms. These differences 1) were dependent on specific features of the RE sequence, 2) could be related to intrinsic differences in their oligomeric state and cooperative DNA binding, and 3) appeared to be conserved in evolution. Sicen genotoxic stress can change relative ratio of TA- and ∆N-P63α protein levels, the different transactivation specificity of each P63 isoform could potentially influence cellular responses to specific stresses.
- Published
- 2014
- Full Text
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