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Authors = Antônio Carlos Fontes dos Santos ORCID = 0000-0001-7402-6594

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11 pages, 1090 KiB  
Article
The Differential Expression of the JAK/STAT Pathway in Breast Cancer Cells Transfected with Human Papillomavirus Oncogenes
by Stephanie Loureiro Leão, Gabriel Rômulo Parente da Silva, Daffany Luana dos Santos, Bianca de França São Marcos, Pedro Henrique Bezerra Fontes, Beatriz Eda de Oliveira Isídio, Isabelle Silva Simões, Elisa Fotin Genn Barros, David Beltrán Lussón, Joelson Germano Crispim, Lígia Rosa Sales Leal, Anna Jéssica Duarte Silva, Vanessa Emanuelle Pereira Santos and Antonio Carlos de Freitas
Viruses 2025, 17(7), 880; https://doi.org/10.3390/v17070880 - 23 Jun 2025
Viewed by 553
Abstract
Breast cancer is among the most prevalent and deadly types of cancer worldwide. Viral infections have been investigated as contributing factors in breast carcinogenesis, including infections by high-risk genotypes of human papillomavirus (HPV). Although viral DNA has been detected in breast tumors, the [...] Read more.
Breast cancer is among the most prevalent and deadly types of cancer worldwide. Viral infections have been investigated as contributing factors in breast carcinogenesis, including infections by high-risk genotypes of human papillomavirus (HPV). Although viral DNA has been detected in breast tumors, the role of HPV activity in this type of cancer remains poorly understood. HPV oncogenes interact with various host genes, including those involved in the JAK/STAT signaling pathway. This pathway is associated with the regulation of gene expression related to the tumor microenvironment, and understanding how HPV oncogenes interact with JAK/STAT components may provide insights into the relationship between the virus and breast cancer development. In this study, we assessed the differential expression of the JAK/STAT pathway in MDA-MB-231 cells individually transfected with the E5, E6, and E7 oncogenes of HPV16. The results revealed downregulation of STAT4 in the presence of the E5, E6, and E7 oncogenes. Notably, cells transfected with E5 alone exhibited upregulation of JAK2, STAT3, and STAT6, whereas transfection with E6 and E7 resulted in their downregulation. These findings highlight the underexplored role of the E5 oncogene in contrast to the more extensively studied E6 and E7. Our results support the hypothesis that HPV oncogenes actively modulate the expression of genes involved in the tumor microenvironment in breast cancer. Full article
(This article belongs to the Special Issue Viral Oncogenes)
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15 pages, 1246 KiB  
Review
E5 Oncoprotein: A Key Player in Human Papillomavirus-Positive Head and Neck Cancer Pathogenesis and Therapy Resistance
by Vanessa Emanuelle Pereira Santos, Bianca de França São Marcos, Pedro Henrique Bezerra Fontes, Micaela Evellin dos Santos Silva, Stephanie Loureiro Leão, Gabriel Rômulo Parente da Silva, Davi Emanuel Ribeiro, Marco Antonio Turiah Machado da Gama, Beatriz Eda de Oliveira Isídio, Ingrid Andrêssa de Moura, David Beltrán Lussón, Lígia Rosa Sales Leal, Aldo Venuti and Antonio Carlos de Freitas
Viruses 2025, 17(4), 512; https://doi.org/10.3390/v17040512 - 1 Apr 2025
Viewed by 1009
Abstract
Head and neck cancer (HNC) is the sixth most prevalent type of cancer worldwide and is associated with low five-year survival rates. Alcoholism and smoking are the main risk factors associated with the development of head and neck cancer (HNC). However, Human Papillomavirus [...] Read more.
Head and neck cancer (HNC) is the sixth most prevalent type of cancer worldwide and is associated with low five-year survival rates. Alcoholism and smoking are the main risk factors associated with the development of head and neck cancer (HNC). However, Human Papillomavirus (HPV) infection has been reported as a significant risk factor, particularly for the oropharyngeal subset. In these cases, patients with HPV-positive HNC exhibit a better clinical prognosis; however, resistance to chemotherapy has been frequently reported. The carcinogenic activity of HPV is related to the viral oncoproteins E5, E6, and E7. E5 has been associated with immune evasion mechanisms and modulation of the tumor microenvironment, which appears to be linked to the virus’s resistance to chemotherapeutic treatments. Here, we review the potential of HPV E5 in targeted therapy for HNC and discuss relevant data regarding the activity of this oncoprotein in head and neck carcinogenesis. Full article
(This article belongs to the Special Issue Host Cell-Virus Interaction, 4th Edition)
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9 pages, 1256 KiB  
Article
Double and Triple Photoionization of CCl4
by Antônio Carlos Fontes dos Santos, Joselito Barbosa Maciel, Alexandre Braga Rocha and Gerardo Gerson Bezerra de Souza
Atoms 2024, 12(12), 74; https://doi.org/10.3390/atoms12120074 - 21 Dec 2024
Viewed by 698
Abstract
(1) Background: Fragmentation after double and triple photoionization of the CCl4 molecule in the valence, Cl 2p, and C 1s regions have been reported; (2) Methods: We have used photoion-photoion (PIPICO) coincidence technique combined with synchrotron radiation. In addition, [...] Read more.
(1) Background: Fragmentation after double and triple photoionization of the CCl4 molecule in the valence, Cl 2p, and C 1s regions have been reported; (2) Methods: We have used photoion-photoion (PIPICO) coincidence technique combined with synchrotron radiation. In addition, ab initio quantum mechanical calculations were done at multiconfigurational self-consistent and multireference configuration interaction to describe ground and inner-shell states; (3) Results: We have observed coincidences involving singly and doubly charged fragments coming from the doubly and triply ionized molecule. We have also found a well agreement between the quantum mechanical calculations and the total ion yield spectrum. It is shown that the Cl+ ion is the predominant product resulting from the fragmentation of the doubly and triply charged CCl4 molecule. The CCl+ + Cl+ pair is the dominant coincidence in the spectra from valence up to the C 1s edge; (4) Conclusions: The kinetic energy of the fragments is compatible with the Coulomb explosion model. Full article
(This article belongs to the Section Atomic, Molecular and Nuclear Spectroscopy and Collisions)
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14 pages, 917 KiB  
Article
HPV Detection in Breast Tumors and Associated Risk Factors in Northeastern Brazil
by Kamylla Conceição Gomes Nascimento, Bianca de França São Marcos, Pedro Henrique Bezerra Fontes, Beatriz Eda de Oliveira Isídio, Stephanie Loureiro Leão, Gabriel Romulo Parente da Silva, David Beltrán Lussón, Daffany Luana dos Santos, Lígia Rosa Sales Leal, Benigno Cristofer Flores Espinoza, Larissa Silva de Macêdo, Pedro Luiz de França Neto, Anna Jéssica Duarte Silva, Jacinto Costa Silva Neto, Vanessa Emanuelle Pereira Santos and Antonio Carlos de Freitas
Cells 2024, 13(13), 1132; https://doi.org/10.3390/cells13131132 - 29 Jun 2024
Viewed by 2468
Abstract
Breast cancer risk factors include lifestyle, genetic–hormonal influences, and viral infections. Human papillomavirus (HPV), known primarily as the etiological agent of cervical cancer, also appears active in breast carcinogenesis, as evidenced in our study of 56 patients from northeastern Brazil. We assessed the [...] Read more.
Breast cancer risk factors include lifestyle, genetic–hormonal influences, and viral infections. Human papillomavirus (HPV), known primarily as the etiological agent of cervical cancer, also appears active in breast carcinogenesis, as evidenced in our study of 56 patients from northeastern Brazil. We assessed the clinical and sociodemographic characteristics, correlating them with various breast cancer tumor types. HPV detection involved amplifying the L1 region, with viral load measured using the E2/E6 ratio and viral activity indicated by E5 oncogene expression. Predominantly, patients over 56 years of age with healthy lifestyles showed a high incidence of invasive ductal carcinoma and triple-negative breast cancer. HPV was detected in 35.7% of cases, mostly HPV16, which is associated with high viral loads (80 copies per cell) and significant E5 expression. These results hint at a possible link between HPV and breast carcinogenesis, necessitating further studies to explore this association and the underlying viral mechanisms. Full article
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9 pages, 1706 KiB  
Communication
Electron Impact Ionization Cross-Section Maxima of Atoms
by Antônio Carlos Fontes dos Santos and Károly Tőkési
Atoms 2023, 11(5), 81; https://doi.org/10.3390/atoms11050081 - 8 May 2023
Cited by 3 | Viewed by 2093
Abstract
Using measured cross-sections and polarizability data, an empirical scaling law is extracted for the electron collision single-ionization cross-section maxima of neutral atoms. We found that the cross sections scale linearly with the target’s static polarizability. We confirm this observation using our present three-body [...] Read more.
Using measured cross-sections and polarizability data, an empirical scaling law is extracted for the electron collision single-ionization cross-section maxima of neutral atoms. We found that the cross sections scale linearly with the target’s static polarizability. We confirm this observation using our present three-body classical trajectory Monte Carlo simulations. Full article
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