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Antonio Giordano

Publications and source records attributed to Antonio Giordano.

At least 19 recordsLinked to original sources
PubMed2026

Epigenetic profiling of circulating cell-free DNA for early detection and minimal residual disease assessment in lung cancer: a focus on DNA methylation.

Lung Cancer (LC) continues to be the biggest cause of cancer-related deaths around the world, mostly because of delayed diagnosis. Even if tissue biopsies and circulating tumor DNA (ctDNA) tests have revolutionized clinical management of LC patients, their effectiveness is restricted in settings with lower tumor burden, molecular heterogeneity, and bias in sampling approaches. In this scenario, the epigenetic profiling of cell-free DNA (cfDNA) stands out as a promising, less invasive approach, accurately detect cancer traces. Evidence from stage I-II disease and CT-detected pulmonary nodules supports the diagnostic potential of cfDNA methylation, although further validation in prospective screening cohorts remains necessary. Beyond genomic alterations, cfDNA epigenetic changes, including DNA methylation, chromatin organization, nucleosome positioning, and fragmentation patterns, reflect multi-dimensional complexity of tumor biology. These properties convey both the functional status and the origin of the circulating DNA fragments, accelerating for tumor integrating genomic analysis. Within this group, DNA methylation is the biologically robust and clinically well-established epigenetic marker, as alterations in methylation linked to cancer often occur in the early stages of tumorigenesis and are commonly found across different cancer cell types. Here, we explored the biological and clinical relevance of the epigenetic landscape of cfDNA in LC patients, particularly focusing on DNA methylation-based biomarkers and their evolving applications towards early diagnosis and post-surgical monitoring of minimal residual disease (MRD). We aimed to comprehensively overview analytical approaches for cfDNA methylation analysis, including targeted and genome-wide profiling strategies, and discuss their integration with machine learning (ML) and multi-omics frameworks in order to improve diagnostic performance and clinical applicability in LC management.

DNA methylation↗
PubMed2024

Adeno-Associated Virus Type 5 Infection via PDGFRα Is Associated With Interstitial Lung Disease in Systemic Sclerosis and Generates Composite Peptides and Epitopes Recognized by the Agonistic Immunoglobulins Present in Patients With Systemic Sclerosis.

OBJECTIVE: The etiopathogenesis of systemic sclerosis (SSc) is unknown. Platelet-derived growth factor receptors (PDGFRs) are overexpressed in patients with SSc. Because PDGFR&#x3b1; is targeted by the adeno-associated virus type 5 (AAV5), we investigated whether AAV5 forms a complex with PDGFR&#x3b1; exposing epitopes that may induce the immune responses to the virus-PDGFR&#x3b1; complex. METHODS: The binding of monomeric human PDGFR&#x3b1; to the AAV5 capsid was analyzed by in silico molecular docking, surface plasmon resonance (SPR), and genome editing of the PDGFR&#x3b1; locus. AAV5 was detected in SSc lungs by in situ hybridization, immunohistochemistry, confocal microscopy, and molecular analysis of bronchoalveolar lavage (BAL) fluid. Immune responses to AAV5 and PDGFR&#x3b1; were evaluated by SPR using SSc monoclonal anti-PDGFR&#x3b1; antibodies and immunoaffinity-purified anti-PDGFR&#x3b1; antibodies from sera of patients with SSc. RESULTS: AAV5 was detected in the BAL fluid of 41 of 66 patients with SSc with interstitial lung disease (62.1%) and in 17 of 66 controls (25.75%) (P <&#x2009;0.001). In SSc lungs, AAV5 localized&#x2009;in type II pneumocytes and in interstitial cells. A molecular complex formed of spatially contiguous epitopes of the AAV5 capsid and of PDGFR&#x3b1; was identified and characterized. In silico molecular docking analysis and binding to the agonistic anti-PDGFR&#x3b1; antibodies identified spatially contiguous epitopes derived from PDGFR&#x3b1; and AAV5 that interacted with SSc agonistic antibodies to PDGFR&#x3b1;. These peptides were also able to bind total IgG isolated from patients with SSc, not from healthy controls. CONCLUSION: These data link AVV5 with the immune reactivity to endogenous antigens in SSc and provide a novel element in the pathogenesis of SSc.

Humans↗
PubMed2004

Mosaic analysis of insulin receptor function.

Insulin promotes both metabolism and growth. However, it is unclear whether insulin-dependent growth is merely a result of its metabolic actions. Targeted ablation of insulin receptor (Insr) has not clarified this issue, because of early postnatal lethality. To examine this question, we generated mice with variable cellular mosaicism for null Insr alleles. Insr ablation in approximately 80% of cells caused extreme growth retardation, lipoatrophy, and hypoglycemia, a clinical constellation that resembles the human syndrome of leprechaunism. Insr ablation in 98% of cells, while resulting in similar growth retardation and lipoatrophy, caused diabetes without beta-cell hyperplasia. The growth retardation was associated with a greater than 60-fold increase in the expression of hepatic insulin-like growth factor binding protein-1. These findings indicate that insulin regulates growth independently of metabolism and that the number of insulin receptors is an important determinant of the specificity of insulin action.

Adipose Tissue↗
PubMed2003

Frequent loss of expression of the cyclin-dependent kinase inhibitor p27(Kip1) in estrogen-related Endometrial adenocarcinomas.

PURPOSE: p27(Kip1) is a member of the Cip1/Kip1 family of cyclin-dependent kinase inhibitors and is a potential tumor suppressor gene. Low levels of p27 are associated with poor prognosis in a variety of gynecological tumors, including breast, ovarian, and cervical carcinomas. The role of p27 in endometrial cancer remains controversial. EXPERIMENTAL DESIGN: In the present study, p27 protein expression was investigated by immunohistochemistry in a series of 217 endometrial adenocarcinomas and, where present, in synchronous normal endometrium, simple and complex hyperplasia (with or without atypia), and cystic atrophy. The relationship between p27 expression and clinical outcome was also evaluated. RESULTS: Immunohistochemical analysis revealed a significant loss of p27 expression from normal (33%) through hyperplastic endometrium (50%) to endometrial adenocarcinomas (71%; P </= 0.001). In addition to nuclear staining, cytoplasmic localization of p27 was noted in 193 (91%) of 217 specimens examined. When the clinical outcome of the patients was evaluated in relation to p27 status, we found no significant correlation between the presence of p27 staining and clinicopathological parameters or survival. CONCLUSIONS: These data indicate that p27 expression could progressively decrease from normal endometrium through hyperplastic endometrium to invasive endometrial carcinomas, suggesting that loss of this tumor suppressor may represent a novel and distinct molecular alteration involved in estrogen-related endometrial adenocarcinomas (type I). Despite the suggested role of the p27 protein in determining the prognosis of several human tumors, it was not found to be a predictor of clinical outcome in this large group of patients with endometrial cancer.

Adenocarcinoma↗
PubMed2003

pRB2/p130 target genes in non-small lung cancer cells identified by microarray analysis.

The retinoblastoma gene family consisting of RB/p105, p107, and RB2/p130 cooperate to regulate cell-cycle progression through the G1 phase of the cell cycle. Previous data demonstrated an independent role for the reduction or loss of pRb2/p130 expression in the formation and/or progression of lung carcinoma. Rb2/p130 is mutated in a human cell line of lung small cell carcinoma as well as in primary lung tumors. To identify potential pRb2/p130 target genes in an unbiased manner, we have utilized an adenovirus-mediated expression system of pRb2/p130 in a non-small lung cancer cell line to identify specific genes that are regulated by pRb2/p130. Using oligonucleotide arrays, a number of Rb2/p130 downregulated genes were identified and their regulation was confirmed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. As a result, 40 genes showed greater than 2.0-fold modification in their expression level after the RB2/p130 viral transduction. In conclusion, coupling adenoviral overexpression with microarray and semiquantitative RT-PCR analyses proved to be a versatile strategy for identifying pRb2/p130 target genes and for better understanding the expression profiles of these genes. Our results may also contribute to identifying novel therapeutic biomarkers in lung carcinoma.

Adenoviridae↗
PubMed2003

Emerging roles of DNA tumor viruses in cell proliferation: new insights into genomic instability.

The small DNA virus proteins E1A and E1B from human Adenovirus, E6 and E7 from human papillomavirus, and large T and small T antigens from SV40, are multifaceted molecular tools that can carry out an impressive number of tasks in the host cell. These viral factors, collectively termed 'oncoproteins' for their ability to induce cancer, can be viewed as paradigmatic oncogenic factors which can disrupt checkpoint controls at multiple levels--they interfere with both 'gatekeeper' cellular functions, including major control pathways of cell cycle and apoptosis, and with 'caretaker' functions, thereby inducing mitotic abnormalities and increasing genomic instability. Both E1A and E7 have been recently found to interact physically with the Ran GTPase. This interaction is key in uncoupling the centrosome cycle from the cell cycle, highlighting a direct link between viral infection and the induction of genomic instability. Further expanding our current knowledge in this field will be crucial to elucidate viral strategies leading to cellular transformation and cancer progression, as well as design novel preventive or therapeutic approaches to human cancer.

Adenovirus E1A Proteins↗
PubMed2003

Advantages and limitations of microarray technology in human cancer.

Cancer is a highly variable disease with multiple heterogeneous genetic and epigenetic changes. Functional studies are essential to understanding the complexity and polymorphisms of cancer. The final deciphering of the complete human genome, together with the improvement of high throughput technologies, is causing a fundamental transformation in cancer research. Microarray is a new powerful tool for studying the molecular basis of interactions on a scale that is impossible using conventional analysis. This technique makes it possible to examine the expression of thousands of genes simultaneously. This technology promises to lead to improvements in developing rational approaches to therapy as well as to improvements in cancer diagnosis and prognosis, assuring its entry into clinical practice in specialist centers and hospitals within the next few years. Predicting who will develop cancer and how this disease will behave and respond to therapy after diagnosis will be one of the potential benefits of this technology within the next decade. In this review, we highlight some of the recent developments and results in microarray technology in cancer research, discuss potentially problematic areas associated with it, describe the eventual use of microarray technology for clinical applications and comment on future trends and issues.

Breast Neoplasms↗
PubMed2003

Genetic and epigenetic alterations as hallmarks of the intricate road to cancer.

Despite the clonal origin of most tumors, their tremendous heterogeneity suggests that cancer progression springs from the combined forces of both genetic and epigenetic events, which produce variant clonal populations, together with the selective pressures of the microenvironment, which promote growth and, perhaps, dissemination of variants with a specific set of characteristics. Although the importance of genetic mutations in cancer has long been recognized, the role of epigenetic events has been suggested more recently. This review focuses on the genetic and epigenetic molecular mechanisms involved in cancer onset and progression, and discusses the possibility of new strategies in the development of anticancer treatments.

Cell Cycle↗
PubMed2003

Interaction between HIV-1 Tat and pRb2/p130: a possible mechanism in the pathogenesis of AIDS-related neoplasms.

Tat protein is an early nonstructural protein necessary for virus replication, which is secreted by infected cells and taken up by uninfected cells. Extensive evidence indicates that Tat may be a cofactor in the development of AIDS-related neoplasms. The molecular mechanism underlying Tat's oncogenic activity may include deregulation of cellular genes. Among these genes, it has recently been shown that pRb2/p130 oncosuppressor protein is one of the targets in the interaction between HIV gene product Tat and host proteins. However, whether the HIV-1 gene product Tat may inactivate the oncosuppressive function of pRb2/p130 has not yet been elucidated. Here, we show that mRNA levels of pRb2/p130 increase in the presence of Tat, whereas no change in the phosphorylation status of pRb2/p130 is observed. In addition, Tat can inhibit the growth control activity exerted by pRb2/p130 in the T98G cell line. Finally, Tat does not compete with E2F-4 in binding to pRb2/p130. The interaction between Tat and pRb2/p130 seems to result in the deregulation of the control exerted by pRb2/p130 on the cell cycle. Taken together, these results open a window on the role of pRb2/p130 in AIDS-related oncogenesis.

Cell Line↗
PubMed2003

Cell cycle regulation and neural differentiation.

The general mechanisms that control the cell cycle in mammalian cells have been studied in depth and several proteins that are involved in the tight regulation of cell cycle progression have been identified. However, the analysis of which molecules participate in cell cycle exit of specific cell lineages is not exhaustive yet. Moreover, the strict relation between cell cycle exit and induction of differentiation has not been fully understood and seems to depend on the cell type. Several in vivo and in vitro studies have been performed in the last few years to address these issues in cells of the nervous system. In this review, we focus our attention on cyclin-cyclin-dependent kinase complexes, cyclin kinase inhibitors, genes of the retinoblastoma family, p53 and N-Myc, and we aim to summarize the latest evidence indicating their involvement in the control of the cell cycle and induction of differentiation in different cell types of the peripheral and central nervous systems. Studies on nervous system tumors and a possible contributory role in tumorigenesis of polyomavirus T antigen are reported to point out the critical contribution of some cell cycle regulators to normal neural and glial development.

Animals↗
PubMed2003

MPA increases idarubicin-induced apoptosis in chronic lymphatic leukaemia cells via caspase-3.

The caspase family of protease is speculated to have a crucial role in apoptosis. The effect of treatment with Idarubicin (IDA) and Medroxyprogesterone acetate (MPA), used alone or in combination, on the activation of Caspase-3 in canine Chronic Lymphatic Leukaemia (CLL) cells was investigated, in order to clarify the mechanism of chemo- and hormone-therapy mediated apoptosis. Caspase activity was determined by a quantitative fluorimetric assay. Apoptosis was monitored by propidium iodide (PI) and nucleosomes assay. Treatment of CLL cells for 24 h with MPA 5 microM did not significantly activate caspase-3 but its activity was increased almost 5-fold more with IDA 1 microM (P < 0.05) than control. Treatment of CLL cells with IDA 1 microM in equimolecular association with MPA was able to increase the activation of caspase-3 induced by IDA of the 61.2% (P < 0.05) in comparison with IDA alone. The activation of caspase-3 was confirmed evaluating apoptosis by PI and nucleosomes assay. Furthermore, both caspase-3 activation and apoptosis triggered by IDA alone or in combination with MPA were significantly inhibited by specific caspase-3 inhibitor AC-DEVD-CMK. These findings provide an explanation for IDA and MPA induced-apoptosis mechanism.

Amino Acid Chloromethyl Ketones↗
PubMed2003

Triggering of p73-dependent apoptosis in osteosarcoma is under the control of E2Fs-pRb2/p130 complexes.

Mechanisms underlying multidrug resistance (MDR), one of the major causes of cancer treatment failure, are still poorly understood. We selected the osteosarcoma MDR HosDXR150 cell line by culturing Hos cells in the presence of increasing doxorubicin doses and showed that it is crossresistant to vinblastine. Similarly to the Hos parental cell line, HosDXR150 cells present mutated p53, functionally inactivated pRb/p105 and wild-type pRb2/p130. Owing to p53 mutation, MDR-1 gene, codifying for P-glycoprotein, is upregulated. Evasion of apoptosis in HosDXR150 cells is only partially explained by drug extrusion because of P-glycoprotein overexpression. Analysis of gene expression level profiles showed that parental cell line undergoes apoptosis through an E2F1/p73-dependent pathway while its resistant variant evades it. This result can be explained by the presence of distinct E2Fs-pRb2/p130 complexes on the p73 promoter. Namely, in Hos p73 transcription is activated by E2F1-Rb2/p130-p300 complexes, while in HosDXR150 it is kept repressed by E2F4-Rb2/p130-HDAC1 complexes.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

pRb2/p130-E2F4/5-HDAC1-SUV39H1-p300 and pRb2/p130-E2F4/5-HDAC1-SUV39H1-DNMT1 multimolecular complexes mediate the transcription of estrogen receptor-alpha in breast cancer.

The estrogen receptor-alpha (ER) plays a crucial role in normal breast development and is also linked to development and progression of mammary carcinoma. The transcriptional repression of ER-alpha gene in breast cancer is an area of active investigation with potential clinical significance. However, the molecular mechanisms that regulate the ER-alpha gene expression are not fully understood. Here we show a new molecular mechanism of ER-alpha gene inactivation mediated by pRb2/p130 in ER-negative breast cancer cells. We investigated in vivo occupancy of ER-alpha promoter by pRb2/p130-E2F4/5-HDAC1-SUV39 H1-p300 and pRb2/p130-E2F4/5-HDAC1-SUV39H1-DNMT1 complexes, and provided a link between pRb2/p130 and chromatin-modifying enzymes in the regulation of ER-alpha transcription in a physiological setting. These findings suggest that pRb2/p130-multimolecular complexes can be key elements in the regulation of ER-alpha gene expression and may be viewed as promising targets for the development of novel therapeutic strategies in the treatment of breast cancer, especially for those tumors that are ER negative.

Acetylation↗
PubMed2003

Sema3A and neuropilin-1 expression and distribution in rat white adipose tissue.

Semaphorins are cell surface and/or soluble signals that exert an inhibitory control on axon guidance. Sema3A, the vertebrate-secreted semaphorin, binds to neuropilin-1, which together with plexins constitutes the functional receptor. To verify whether Sema3A is produced by white adipocytes and, in that case, to detect its targets in white adipose tissue, we studied the cell production and tissue distribution of Sema3A and neuropilin-1 in rat retroperitoneal and epididymal adipose depots. Sema3A and neuropilin-1 were detected in these depots by Western blotting. The immunohistochemical results showed that Sema3A is produced in, and possibly secreted by, smooth muscle cells of arteries and white adipocytes. Accordingly, neuropilin-1 was found on perivascular and parenchymal nerves. Such a pattern of distribution is in line with a role for secreted Sema3A in the growth and plasticity of white adipose tissue nerves. Indeed, after fasting, when white adipocytes are believed to be overstimulated by noradrenaline and rearrangement of the parenchymal nerve supply may occur, adipocytic expression of Sema3A is reduced. Finally, the presence of neuropilin-1 in some white adipocytes raises the interesting possibility that Sema3A also exerts an autocrine-paracrine role on these cells.

Adipocytes↗
PubMed2002

Cdk9, a member of the cdc2-like family of kinases, binds to gp130, the receptor of the IL-6 family of cytokines.

Cdk9 is a member of the Cdc2-like family of kinases. It binds to members of the family of cyclin T (T1, T2a and T2b) and to cyclin K. The Cdk9/cyclin T complex appears to be involved in regulating several physiological processes. In fact Cdk9 is the kinase of the P-TEFb complex, involved in basal transcription. Cdk9 has also been described as the kinase of the TAK complex, homologous to P-TEFb and involved in HIV replication. Here we show that Cdk9 interacts with gp130, the receptor of the Interleukin-6 (IL-6) family of cytokines, which includes Leukemia Inhibitory Factor (LIF), Oncostatin M (OSM), Ciliary Neurotrophic Factor (CNTF), Interleukin-11 (IL-11) and Cardiotrophin (CT-1). IL-6 is a key regulator of hematopoiesis, immunological responses and inflammation. In addition, IL-6 plays a major role in the endocrine and nervous systems. Signal transduction by gp130 is mediated by physical interaction of the cytoplasmic region of gp130 with cellular kinases and results in the transcriptional activation of cellular and viral genes. We found that Cdk9 interacts in vitro with the cytoplasmic region of gp130 and we succeded in reproducing this interaction in vivo. Cdk9 expression was found both in the nucleus and in the cytoplasm. The binding occurring between Cdk9 and gp130 increased upon IL-6 stimulation. We also observed that Cdk9 synergized with IL-6 in inducing the activation of an IL-6-responsive reporter plasmid. In summary, these results point to a previously undisclosed role for Cdk9 in signal transduction.

Antigens, CD↗
PubMed2002

Activation and function of cyclin T-Cdk9 (positive transcription elongation factor-b) in cardiac muscle-cell hypertrophy.

Hypertrophic growth is a risk factor for mortality in heart diseases. Mechanisms are lacking for this global increase in RNA and protein per cell, which underlies hypertrophy. Hypertrophic signals cause phosphorylation of the RNA polymerase II C-terminal domain, required for transcript elongation. RNA polymerase II kinases include cyclin-dependent kinases-7 (Cdk7) and Cdk9, components of two basal transcription factors. We report activation of Cdk7 and -9 in hypertrophy triggered by signaling proteins (Galphaq, calcineurin) or chronic mechanical stress. Only Cdk9 was activated by acute load or, in culture, by endothelin. A preferential role for Cdk9 was shown in RNA polymerase II phosphorylation and growth induced by endothelin, using pharmacological and dominant-negative inhibitors. All four hypertrophic signals dissociated 7SK small nuclear RNA, an endogenous inhibitor, from cyclin T-Cdk9. Cdk9 was limiting for cardiac growth, shown by suppressing its inhibitor (7SK) in culture and preventing downregulation of its activator (cyclin T1) in mouse myocardium.Note: In the AOP version of this article, the numbering of the author affiliations was incorrect. This has now been fixed, and the affiliations appear correctly online and in print.

Animals↗