Giacomo Buscemi
Istituto di Genetica Molecolare “Luigi Luca Cavalli-Sforza” – CNR
Via Abbiategrasso, 207
27100 Pavia
Phone: 0382 546327
E-mail: giacomo.buscemi@igm.cnr.it
Curriculum Vitae – Download
Complete List of Publications – Download
Research Activity
Cellular DNA is under the constant attack of physical and chemical agents. Internal factors, such as free radicals produced by normal cellular metabolism, and external factors, such as ultraviolet rays from the sun or chemicals present in air pollution, in industrial foods or in smoke, are able to modify the structure of nuclear DNA. Under normal conditions, each of the cells in our body is affected, recognizes and repairs tens of thousands of DNA lesions every day, preserving the original genetic information to be transmitted to the daughter cells. The fate of the cells depends on the ability to maintain the integrity of the genome, in fact defects in the response to DNA damage and in its repair can cause that genomic instability which, for example, facilitates their transformation into cancer cells. Indeed, several genetic diseases, frequently characterized by predisposition to the onset of tumors, are caused by defects in the genes involved in the DNA damage response. In human cells this response is very complex and can involve hundreds of proteins. Several factors have been described, however, in many cases, their biochemical functions are unclear.
Overall, my studies aim to dissect molecular mechanisms of the DNA damage response, relevant to preserve genome stability, identifying possible markers but also substrates for a targeted therapeutic approach for tumors or rare genetic diseases.
In the past, studying disorders such as Telangiectasia Ataxia or Nijmegen Chromosomal Breakage Syndrome, I identified new molecular mechanisms in human cells in the signaling system for the presence of breaks of both DNA strands. The subtle modulation of these mechanisms in the cell decides how to repair each lesion, if it is necessary to transiently sarrest the cell cycle in order not to worsen the damage, if it is necessary to induce premature cellular senescence or even to plan cell suicide rather than transmitting to the daughter cells a modified genome, thus risking the onset of a lethal disease for the organism. I also studied some aspects of telomere protection that avoid chromosome ends from being recognized and treated as DNA breaks, preventing unwanted repair activities that can lead to chromosome fusion.
Currently, in collaboration with other laboratories both of the IGM-CNR and of the University of Milan and Bari, I am dealing with the detailed analysis of the mechanisms that govern the choice of how to repair DSBs according to the chromatin and transcriptional context in which they happen. In particular, I am studying the role of products of the BRCA1 and BRCA2 genes, known to be mutated in hereditary breast cancer and the SETX gene, whose mutations cause type 2 Oculomotor Apraxia (AOA2) a rare form of juvenile amyotrophic lateral sclerosis.
Recent Publications
2023
|
Cardano M; Magni M; Alfieri R; Chan SY; Sabbioneda S; Buscemi G; Zannini L Sex specific regulation of TSPY-Like 2 in the DNA damage response of cancer cells Journal Article In: Cell death and disease, vol. 14, iss. 3, pp. 197, 2023. @article{%a1.%Yb_68,
title = {Sex specific regulation of TSPY-Like 2 in the DNA damage response of cancer cells},
author = {Cardano M and Magni M and Alfieri R and Chan SY and Sabbioneda S and Buscemi G and Zannini L},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10015022/},
doi = {10.1038/s41419-023-05722-2},
year = {2023},
date = {2023-03-01},
journal = {Cell death and disease},
volume = {14},
issue = {3},
pages = {197},
abstract = {Females have a lower probability to develop somatic cancers and a better response to chemotherapy than males. However, the reasons for these differences are still not well understood. The X-linked gene TSPY-Like 2 (TSPYL2) encodes for a putative tumor suppressor protein involved in cell cycle regulation and DNA damage response (DDR) pathways. Here, we demonstrate that in unstressed conditions TSPYL2 is maintained at low levels by MDM2-dependent ubiquitination and proteasome degradation. Upon genotoxic stress, E2F1 promotes TSPYL2 expression and protein accumulation in non-transformed cell lines. Conversely, in cancer cells, TSPYL2 accumulates only in females or in those male cancer cells that lost the Y-chromosome during the oncogenic process. Hence, we demonstrate that while TSPYL2 mRNA is induced in all the tested tumor cell lines after DNA damage, TSPYL2 protein stability is increased only in female cancer cells. Indeed, we found that TSPYL2 accumulation, in male cancer cells, is prevented by the Y-encoded protein SRY, which modulates MDM2 protein levels. In addition, we demonstrated that TSPYL2 accumulation is required to sustain cell growth arrest after DNA damage, possibly contributing to protect normal and female cancer cells from tumor progression. Accordingly, TSPYL2 has been found more frequently mutated in female-specific cancers. These findings demonstrate for the first time a sex-specific regulation of TSPYL2 in the DDR of cancer cells and confirm the existence of sexual dimorphism in DNA surveillance pathways.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Females have a lower probability to develop somatic cancers and a better response to chemotherapy than males. However, the reasons for these differences are still not well understood. The X-linked gene TSPY-Like 2 (TSPYL2) encodes for a putative tumor suppressor protein involved in cell cycle regulation and DNA damage response (DDR) pathways. Here, we demonstrate that in unstressed conditions TSPYL2 is maintained at low levels by MDM2-dependent ubiquitination and proteasome degradation. Upon genotoxic stress, E2F1 promotes TSPYL2 expression and protein accumulation in non-transformed cell lines. Conversely, in cancer cells, TSPYL2 accumulates only in females or in those male cancer cells that lost the Y-chromosome during the oncogenic process. Hence, we demonstrate that while TSPYL2 mRNA is induced in all the tested tumor cell lines after DNA damage, TSPYL2 protein stability is increased only in female cancer cells. Indeed, we found that TSPYL2 accumulation, in male cancer cells, is prevented by the Y-encoded protein SRY, which modulates MDM2 protein levels. In addition, we demonstrated that TSPYL2 accumulation is required to sustain cell growth arrest after DNA damage, possibly contributing to protect normal and female cancer cells from tumor progression. Accordingly, TSPYL2 has been found more frequently mutated in female-specific cancers. These findings demonstrate for the first time a sex-specific regulation of TSPYL2 in the DDR of cancer cells and confirm the existence of sexual dimorphism in DNA surveillance pathways. |
2022
|
Cardano M; Buscemi G; Zannini L Sex disparities in DNA damage response pathways: Novel determinants in cancer formation and therapy Journal Article In: iScience, vol. 25, iss. 3, pp. 103875, 2022. @article{%a1.%Ybq,
title = {Sex disparities in DNA damage response pathways: Novel determinants in cancer formation and therapy},
author = {Cardano M and Buscemi G and Zannini L},
url = {https://www.sciencedirect.com/science/article/pii/S2589004222001456?via%3Dihub},
doi = {10.1016/j.isci.2022.103875},
year = {2022},
date = {2022-05-30},
journal = {iScience},
volume = {25},
issue = {3},
pages = {103875},
abstract = {Cancer incidence and survival are different between men and women. Indeed, females have a lesser risk and a better prognosis than males in many tumors unrelated to reproductive functions. Although the reasons for these disparities are still unknown, they constitute an important starting point for the development of personalized cancer therapies. One of the mechanisms that fuels carcinogenesis is the accumulation of defects in DNA damage response (DDR) pathways, a complex signaling cascade that senses DNA lesions and, depending on the severity, coordinates transient cell-cycle arrest, DNA replication, repair, apoptosis, and senescence, preventing genomic instability and cancer. Recently, evidence of sexual dimorphisms is emerging in these pathways, therefore providing new opportunities for precision medicine. Here, we will discuss current knowledge about sexual disparities in the DDR, their role in tumorigenesis and cancer progression, and the importance of considering sex contribution in both research and cancer therapies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cancer incidence and survival are different between men and women. Indeed, females have a lesser risk and a better prognosis than males in many tumors unrelated to reproductive functions. Although the reasons for these disparities are still unknown, they constitute an important starting point for the development of personalized cancer therapies. One of the mechanisms that fuels carcinogenesis is the accumulation of defects in DNA damage response (DDR) pathways, a complex signaling cascade that senses DNA lesions and, depending on the severity, coordinates transient cell-cycle arrest, DNA replication, repair, apoptosis, and senescence, preventing genomic instability and cancer. Recently, evidence of sexual dimorphisms is emerging in these pathways, therefore providing new opportunities for precision medicine. Here, we will discuss current knowledge about sexual disparities in the DDR, their role in tumorigenesis and cancer progression, and the importance of considering sex contribution in both research and cancer therapies. |
2020
|
Sanese P; Fasano C; Buscemi G; Bottino C; Corbetta S; Fabini E; Silvestri V; Valentini V; Disciglio V; Forte G; Lepore Signorile M; De Marco K; Bertora S; Grossi V; Guven U; Porta N; Di Maio V; Manoni E; Giannelli G; Bartolini M; Del Rio A; Caretti G; Ottini L; Simone C Targeting SMYD3 to Sensitize Homologous Recombination-Proficient Tumors to PARP-Mediated Synthetic Lethality. Journal Article In: iScience, vol. 23, no. 10, pp. 101604, 2020. @article{%a1:%Y_474,
title = {Targeting SMYD3 to Sensitize Homologous Recombination-Proficient Tumors to PARP-Mediated Synthetic Lethality. },
author = {Sanese P and Fasano C and Buscemi G and Bottino C and Corbetta S and Fabini E and Silvestri V and Valentini V and Disciglio V and Forte G and Lepore Signorile M and De Marco K and Bertora S and Grossi V and Guven U and Porta N and Di Maio V and Manoni E and Giannelli G and Bartolini M and {Del Rio A} and Caretti G and Ottini L and Simone C},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7648160/},
doi = {10.1016/j.isci.2020.101604},
year = {2020},
date = {2020-01-01},
journal = {iScience},
volume = {23},
number = {10},
pages = {101604},
abstract = {SMYD3 is frequently overexpressed in a wide variety of cancers. Indeed, its inactivation reduces tumor growth in preclinical in vivo animal models. However, extensive characterization in vitro failed to clarify SMYD3 function in cancer cells, although confirming its importance in carcinogenesis. Taking advantage of a SMYD3 mutant variant identified in a high-risk breast cancer family, here we show that SMYD3 phosphorylation by ATM enables the formation of a multiprotein complex including ATM, SMYD3, CHK2, and BRCA2, which is required for the final loading of RAD51 at DNA double-strand break sites and completion of homologous recombination (HR). Remarkably, SMYD3 pharmacological inhibition sensitizes HR-proficient cancer cells to PARP inhibitors, thereby extending the potential of the synthetic lethality approach in human tumors.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
SMYD3 is frequently overexpressed in a wide variety of cancers. Indeed, its inactivation reduces tumor growth in preclinical in vivo animal models. However, extensive characterization in vitro failed to clarify SMYD3 function in cancer cells, although confirming its importance in carcinogenesis. Taking advantage of a SMYD3 mutant variant identified in a high-risk breast cancer family, here we show that SMYD3 phosphorylation by ATM enables the formation of a multiprotein complex including ATM, SMYD3, CHK2, and BRCA2, which is required for the final loading of RAD51 at DNA double-strand break sites and completion of homologous recombination (HR). Remarkably, SMYD3 pharmacological inhibition sensitizes HR-proficient cancer cells to PARP inhibitors, thereby extending the potential of the synthetic lethality approach in human tumors. |
2019
|
Magni M; Buscemi G; Maita L; Peng L; Chan SY; Montecucco A; Delia D; Zannini L TSPYL2 is a novel regulator of SIRT1 and p300 activity in response to DNA damage. Journal Article In: Cell death and differentiation, vol. 26, no. 5, pp. 918-931, 2019. @article{%a1:%Y_79,
title = {TSPYL2 is a novel regulator of SIRT1 and p300 activity in response to DNA damage.},
author = {Magni M and Buscemi G and Maita L and Peng L and Chan SY and Montecucco A and Delia D and Zannini L},
url = {https://www.nature.com/articles/s41418-018-0168-6},
doi = {10.1038/s41418-018-0168-6},
year = {2019},
date = {2019-03-06},
journal = {Cell death and differentiation},
volume = {26},
number = {5},
pages = {918-931},
abstract = {Protein acetylation and deacetylation events are finely regulated by lysine-acetyl-transferases and lysine-deacetylases and constitute an important tool for the activation or inhibition of specific cellular pathways. One of the most important lysine-acetyl-transferases is p300, which is involved in the regulation of gene expression, cell growth, DNA repair, differentiation, apoptosis, and tumorigenesis. A well-known target of p300 is constituted by the tumor suppressor protein p53, which plays a critical role in the maintenance of genomic stability and whose activity is known to be controlled by post-translational modifications, among which acetylation. p300 activity toward p53 is negatively regulated by the NAD-dependent deacetylase SIRT1, which deacetylates p53 preventing its transcriptional activation and the induction of p53-dependent apoptosis. However, the mechanisms responsible for p53 regulation by p300 and SIRT1 are still poorly understood. Here we identify the nucleosome assembly protein TSPY-Like 2 (TSPYL2, also known as TSPX, DENTT, and CDA1) as a novel regulator of SIRT1 and p300 function. We demonstrate that, upon DNA damage, TSPYL2 inhibits SIRT1, disrupting its association with target proteins, and promotes p300 acetylation and activation, finally stimulating p53 acetylation and p53-dependent cell death. Indeed, in response to DNA damage, cells silenced for TSPYL2 were found to be defective in p53 activation and apoptosis induction and these events were shown to be dependent on SIRT1 and p300 function. Collectively, our results shed new light on the regulation of p53 acetylation and activation and reveal a novel TSPYL2 function with important implications in cancerogenesis.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Protein acetylation and deacetylation events are finely regulated by lysine-acetyl-transferases and lysine-deacetylases and constitute an important tool for the activation or inhibition of specific cellular pathways. One of the most important lysine-acetyl-transferases is p300, which is involved in the regulation of gene expression, cell growth, DNA repair, differentiation, apoptosis, and tumorigenesis. A well-known target of p300 is constituted by the tumor suppressor protein p53, which plays a critical role in the maintenance of genomic stability and whose activity is known to be controlled by post-translational modifications, among which acetylation. p300 activity toward p53 is negatively regulated by the NAD-dependent deacetylase SIRT1, which deacetylates p53 preventing its transcriptional activation and the induction of p53-dependent apoptosis. However, the mechanisms responsible for p53 regulation by p300 and SIRT1 are still poorly understood. Here we identify the nucleosome assembly protein TSPY-Like 2 (TSPYL2, also known as TSPX, DENTT, and CDA1) as a novel regulator of SIRT1 and p300 function. We demonstrate that, upon DNA damage, TSPYL2 inhibits SIRT1, disrupting its association with target proteins, and promotes p300 acetylation and activation, finally stimulating p53 acetylation and p53-dependent cell death. Indeed, in response to DNA damage, cells silenced for TSPYL2 were found to be defective in p53 activation and apoptosis induction and these events were shown to be dependent on SIRT1 and p300 function. Collectively, our results shed new light on the regulation of p53 acetylation and activation and reveal a novel TSPYL2 function with important implications in cancerogenesis. |
2018
|
Magni M; Buscemi G; Zannini L Cell cycle and apoptosis regulator 2 at the interface between DNA damage response and cell physiology Journal Article In: Mutation research - Reviews in Mutation Research, vol. 776, pp. 1-9, 2018. @article{%a1:%Y_154,
title = {Cell cycle and apoptosis regulator 2 at the interface between DNA damage response and cell physiology},
author = {Magni M and Buscemi G and Zannini L},
url = {https://www.sciencedirect.com/science/article/pii/S1383574218300073?via%3Dihub},
doi = {10.1016/j.mrrev.2018.03.004},
year = {2018},
date = {2018-02-14},
journal = {Mutation research - Reviews in Mutation Research},
volume = {776},
pages = {1-9},
abstract = {Cell cycle and apoptosis regulator 2 (CCAR2 or DBC1) is a human protein recently emerged as a novel and important player of the DNA damage response (DDR). Indeed, upon genotoxic stress, CCAR2, phosphorylated by the apical DDR kinases ATM and ATR, increases its binding to the NAD+-dependent histone deacetylase SIRT1 and inhibits SIRT1 activity. This event promotes the acetylation and activation of p53, a SIRT1 target, and the subsequent induction of p53 dependent apoptosis. In addition, CCAR2 influences DNA repair pathway choice and promotes the chromatin relaxation necessary for the repair of heterochromatic DNA lesions. However, besides DDR, CCAR2 is involved in several other cellular functions. Indeed, through the interaction with transcription factors, nuclear receptors, epigenetic modifiers and RNA polymerase II, CCAR2 regulates transcription and transcript elongation. Moreover, promoting Rev-erbα protein stability and repressing BMAL1 and CLOCK expression, it was reported to modulate the circadian rhythm. Through SIRT1 inhibition, CCAR2 is also involved in metabolism control and, suppressing RelB and p65 activities in the NFkB pathway, it restricts B cell proliferation and immunoglobulin production. Notably, CCAR2 expression is deregulated in several tumors and, compared to the non-neoplastic counterpart, it may be up- or down-regulated. Since its up-regulation in cancer patients is usually associated with poor prognosis and its depletion reduces cancer cell growth in vitro, CCAR2 was suggested to act as a tumor promoter. However, there is also evidence that CCAR2 functions as a tumor suppressor and therefore its role in cancer formation and progression is still unclear. In this review we discuss CCAR2 functions in the DDR and its multiple biological activities in unstressed cells.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cell cycle and apoptosis regulator 2 (CCAR2 or DBC1) is a human protein recently emerged as a novel and important player of the DNA damage response (DDR). Indeed, upon genotoxic stress, CCAR2, phosphorylated by the apical DDR kinases ATM and ATR, increases its binding to the NAD+-dependent histone deacetylase SIRT1 and inhibits SIRT1 activity. This event promotes the acetylation and activation of p53, a SIRT1 target, and the subsequent induction of p53 dependent apoptosis. In addition, CCAR2 influences DNA repair pathway choice and promotes the chromatin relaxation necessary for the repair of heterochromatic DNA lesions. However, besides DDR, CCAR2 is involved in several other cellular functions. Indeed, through the interaction with transcription factors, nuclear receptors, epigenetic modifiers and RNA polymerase II, CCAR2 regulates transcription and transcript elongation. Moreover, promoting Rev-erbα protein stability and repressing BMAL1 and CLOCK expression, it was reported to modulate the circadian rhythm. Through SIRT1 inhibition, CCAR2 is also involved in metabolism control and, suppressing RelB and p65 activities in the NFkB pathway, it restricts B cell proliferation and immunoglobulin production. Notably, CCAR2 expression is deregulated in several tumors and, compared to the non-neoplastic counterpart, it may be up- or down-regulated. Since its up-regulation in cancer patients is usually associated with poor prognosis and its depletion reduces cancer cell growth in vitro, CCAR2 was suggested to act as a tumor promoter. However, there is also evidence that CCAR2 functions as a tumor suppressor and therefore its role in cancer formation and progression is still unclear. In this review we discuss CCAR2 functions in the DDR and its multiple biological activities in unstressed cells. |
