RESUMO
Radiotherapy is a key treatment option for a wide variety of human tumors, employed either alone or alongside with other therapeutic interventions. Radiotherapy uses high-energy particles to destroy tumor cells, blocking their ability to divide and proliferate. The effectiveness of radiotherapy is due to genetic and epigenetic factors that determine how tumor cells respond to ionizing radiation. These factors contribute to the establishment of resistance to radiotherapy, which increases the risk of poor clinical prognosis of patients. Although the mechanisms by which tumor cells induce radioresistance are unclear, evidence points out several contributing factors including the overexpression of DNA repair systems, increased levels of reactive oxygen species, alterations in the tumor microenvironment, and enrichment of cancer stem cell populations. In this context, dysregulation of microRNAs or miRNAs, critical regulators of gene expression, may influence how tumors respond to radiation. There is increasing evidence that miRNAs may act as sensitizers or enhancers of radioresistance, regulating key processes such as the DNA damage response and the cell death signaling pathway. Furthermore, expression and activity of miRNAs have shown informative value in overcoming radiotherapy and long-term radiotoxicity, revealing their potential as biomarkers. In this review, we will discuss the molecular mechanisms associated with the response to radiotherapy and highlight the central role of miRNAs in regulating the molecular mechanisms responsible for cellular radioresistance. We will also review radio-miRs, radiotherapy-related miRNAs, either as sensitizers or enhancers of radioresistance that hold promise as biomarkers or pharmacological targets to sensitize radioresistant cells.
Assuntos
MicroRNAs , Neoplasias , Tolerância a Radiação , MicroRNAs/genética , MicroRNAs/metabolismo , Humanos , Tolerância a Radiação/genética , Neoplasias/radioterapia , Neoplasias/genética , Neoplasias/metabolismo , Reparo do DNA , Animais , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Dano ao DNARESUMO
Cervical cancer (CC) remains among the most frequent cancers worldwide despite advances in screening and the development of vaccines against human papillomavirus (HPV), involved in virtually all cases of CC. In mid-income countries, a substantial proportion of the cases are diagnosed in advanced stages, and around 40% of them are diagnosed in women under 49 years, just below the global median age. This suggests that members of this age group share common risk factors, such as chronic inflammation. In this work, we studied samples from 46 patients below 45 years old, searching for a miRNA profile regulating cancer pathways. We found 615 differentially expressed miRNAs between tumor samples and healthy tissues. Through bioinformatic analysis, we found that several of them targeted elements of the JAK/STAT pathway and other inflammation-related pathways. We validated the interactions of miR-30a and miR-34c with JAK1 and STAT3, respectively, through dual-luciferase and expression assays in cervical carcinoma-derived cell lines. Finally, through knockdown experiments, we observed that these miRNAs decreased viability and promoted proliferation in HeLa cells. This work contributes to understanding the mechanisms through which HPV regulates inflammation, in addition to its canonical oncogenic function, and brings attention to the JAK/STAT signaling pathway as a possible diagnostic marker for CC patients younger than 45 years. To our knowledge to date, there has been no previous description of a panel of miRNAs or even ncRNAs in young women with locally advanced cervical cancer.
Assuntos
Regulação Neoplásica da Expressão Gênica , Inflamação , MicroRNAs , Fator de Transcrição STAT3 , Transdução de Sinais , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , MicroRNAs/genética , MicroRNAs/metabolismo , Transdução de Sinais/genética , Adulto , Inflamação/genética , Inflamação/patologia , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Células HeLa , Janus Quinase 1/metabolismo , Janus Quinase 1/genética , Proliferação de Células/genética , Linhagem Celular Tumoral , Pessoa de Meia-IdadeRESUMO
Expression of miR-21 has been found to be altered in almost all types of cancers, and it has been classified as an oncogenic microRNA. In addition, the expression of tumor suppressor gene RECK is associated with miR-21 overexpression in high-grade cervical lesions. In the present study, we analyze the role of miR-21 in RECK gene regulation in cervical cancer cells. To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression using siRNAs. We analyzed the expression of miR-21 and RECK, as well as functional effects on cell proliferation and migration. We found that in cervical cancer cells, there was an inverse correlation between miR-21 expression and RECK mRNA and protein expression. SiRNAs to miR-21 increased luciferase reporter activity in construct plasmids containing the RECK-3'-UTR microRNA response elements MRE21-1, MRE21-2, and MRE21-3. The role of miR-21 in cell proliferation was also analyzed, and cancer cells transfected with siRNAs exhibited a markedly reduced cell proliferation and migration. Our findings indicate that miR-21 post-transcriptionally down-regulates the expression of RECK to promote cell proliferation and cell migration inhibition in cervical cancer cell survival. Therefore, miR-21 and RECK may be potential therapeutic targets in gene therapy for cervical cancer.
Assuntos
MicroRNAs , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Transdução de Sinais , Proliferação de Células/genética , Movimento Celular/genética , RNA Interferente Pequeno , MicroRNAs/genética , Agitação Psicomotora , RNA de Cadeia Dupla , Proteínas Ligadas por GPI/genéticaRESUMO
Small molecules are components of fungal extracellular vesicles (EVs), but their biological roles are only superficially known. NOP16 is a eukaryotic gene that is required for the activity of benzimidazoles against Cryptococcus deuterogattii. In this study, during the phenotypic characterization of C. deuterogattii mutants expected to lack NOP16 expression, we observed a reduced EV production. Whole-genome sequencing, RNA-Seq, and cellular proteomics revealed that, contrary to our initial findings, these mutants expressed Nop16 but exhibited altered expression of 14 genes potentially involved in sugar transport. Based on this observation, we designated these mutant strains as Past1 and Past2, representing potentially altered sugar transport. Analysis of the small molecule composition of EVs produced by wild-type cells and the Past1 and Past2 mutant strains revealed not only a reduced number of EVs but also an altered small molecule composition. In a Galleria mellonella model of infection, the Past1 and Past2 mutant strains were hypovirulent. The hypovirulent phenotype was reverted when EVs produced by wild-type cells, but not mutant EVs, were co-injected with the mutant cells in G. mellonella. These results connect EV biogenesis, cargo, and cryptococcal virulence.
RESUMO
Autophagy is a highly conserved multistep lysosomal degradation process in which cellular components are localized to autophagosomes, which subsequently fuse with lysosomes to degrade the sequestered contents. Autophagy serves to maintain cellular homeostasis. There is a close relationship between autophagy and tumor progression, which provides opportunities for the development of anticancer therapeutics that target the autophagy pathway. In this review, we analyze the effects of human papillomavirus (HPV) E5, E6, and E7 oncoproteins on autophagy processes in cervical cancer development. Inhibition of the expression or the activity of E5, E6, and E7 can induce autophagy in cells expressing HPV oncogenes. Thus, E5, E6, and E7 oncoproteins target autophagy during HPV-associated carcinogenesis. Furthermore, noncoding RNA (ncRNA) expression profiling in cervical cancer has allowed the identification of autophagy-related ncRNAs associated with HPV. Autophagy-related genes are essential drivers of autophagy and are regulated by ncRNAs. We review the existing evidence regarding the role of autophagy-related proteins, the function of HPV E5, E6, and E7 oncoproteins, and the effects of noncoding RNA on autophagy regulation in the setting of cervical carcinogenesis. By characterizing the mechanisms behind the dysregulation of these critical factors and their impact on host cell autophagy, we advance understanding of the relationship between autophagy and progression from HPV infection to cervical cancer, and highlight pathways that can be targeted in preventive and therapeutic strategies against cervical cancer.
Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Autofagia/genética , Carcinogênese/genética , Feminino , Humanos , Proteínas Oncogênicas Virais/metabolismo , Papillomaviridae/genética , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/patologia , RNA não Traduzido/genética , Neoplasias do Colo do Útero/patologiaRESUMO
BACKGROUND: Cryptococcus neoformans is an opportunistic fungal pathogen that can cause meningitis in immunocompromised individuals. The objective of this work was to study the relationship between the phenotypes and genotypes of isolates of clinical origin from different cities in Colombia. METHODS: Genome classification of 29 clinical isolates of C. neoformans var. grubii was performed using multilocus sequence typing (MLST), and genomic sequencing was used to genotype protein-coding genes. Pathogenicity was assessed in a larval model, and melanin production and capsule size were evaluated in vitro and in vivo. RESULTS: Eleven MLST sequence types (STs) were found, the most frequent being ST69 (n = 9), ST2, ST93, and ST377 (each with n = 4). In the 29 isolates, different levels of pigmentation, capsule size and pathogenicity were observed. Isolates classified as highly pathogenic showed a tendency to exhibit larger increases in capsule size. In the analysis of polymorphisms, 48 non-synonymous variants located in the predicted functional domains of 39 genes were found to be associated with capsule size change, melanin, or pathogenicity. CONCLUSIONS: No clear patterns were found in the analysis of the phenotype and genotype of Cryptococcus. However, the data suggest that the increase in capsule size is a key variable for the differentiation of pathogenic isolates, regardless of the method used for its induction.
RESUMO
In fungi, metals are associated with the expression of virulence factors. However, it is unclear whether the uptake of metals affects their pathogenicity. This study aimed to evaluate the effect of iron/copper in modulating pathogenicity and proteomic response in two clinical isolates of C. neoformans with high and low pathogenicity. METHODS: In both isolates, the effect of 50 µM iron and 500 µM copper on pathogenicity, capsule induction, and melanin production was evaluated. We then performed a quantitative proteomic analysis of cytoplasmic extracts exposed to that combination. Finally, the effect on pathogenicity by iron and copper was evaluated in eight additional isolates. RESULTS: In both isolates, the combination of iron and copper increased pathogenicity, capsule size, and melanin production. Regarding proteomic data, proteins with increased levels after iron and copper exposure were related to biological processes such as cell stress, vesicular traffic (Ap1, Vps35), cell wall structure (Och1, Ccr4, Gsk3), melanin biosynthesis (Hem15, Mln2), DNA repair (Chk1), protein transport (Mms2), SUMOylation (Uba2), and mitochondrial transport (Atm1). Increased pathogenicity by exposure to metal combination was also confirmed in 90% of the eight isolates. CONCLUSIONS: The combination of these metals enhances pathogenicity and increases the abundance of proteins related to the main virulence factors.
RESUMO
Due to its location, the fungal cell wall is the compartment that allows the interaction with the environment and/or the host, playing an important role during infection as well as in different biological functions such as cell morphology, cell permeability and protection against stress. All these processes involve the activation of signaling pathways within the cell. The cell wall integrity (CWI) pathway is the main route responsible for maintaining the functionality and proper structure of the cell wall. This pathway is highly conserved in the fungal kingdom and has been extensively characterized in Saccharomyces cerevisiae. However, there are still many unknown aspects of this pathway in the pathogenic fungi, such as Cryptococcus neoformans. This yeast is of particular interest because it is found in the environment, but can also behave as pathogen in multiple organisms, including vertebrates and invertebrates, so it has to adapt to multiple factors to survive in multiple niches. In this review, we summarize the components of the CWI pathway in C. neoformans as well as its involvement in different aspects such as virulence factors, morphological changes, and its role as target for antifungal therapies among others.
RESUMO
Prostate cancer is one of the main causes of cancer and the sixth cause of death among men worldwide. One of the major challenges in prostate cancer research is cell heterogeneity defined as the different genomic and phenotypic characteristics in each individual cell making more difficult to assess the proper prostate cancer diagnosis and therapy. Tumor 3D spatial arrangement allow a strong interaction between the different cellular lineages and components which modulate cell proliferation, differentiation, and morphology. Prostate cancer spheroids are a cellular model which is capable to mimic the mechanical tensions of tumor tissue, providing a more representative pathophysiological model than the use of conventional 2D culture. Here, we describe a protocol to develop a 3D model of spheroids using prostate cancer cell lines (LNCaP, PC3, VCaP) which can be used to improve research considering tumoral heterogeneity role in cancer development, prognosis, and therapy.
Assuntos
Neoplasias da Próstata/patologia , Esferoides Celulares/patologia , Linhagem Celular Tumoral , Humanos , Masculino , Células PC-3RESUMO
Optimal function of the immune system allows the recognition and elimination of infected and tumor cells. However, these cells can develop mechanisms to evade the cellular immune response. In human papillomavirus (HPV) infection, dysregulation of major histocompatibility complex Class I molecules and other components of the innate immune system promote the survival of infected cells by allowing the infection to persist which, in turn, favors the development of cancer. Further, tumor cells possess inherent mechanisms designed to block the recognition and activation of cytotoxic lymphocytes: particularly, HPV proteins such as E1 and E2 and oncoproteins E5, E6, and E7 that inhibit immune mechanisms and/or stimulate the expression of immunosuppressive cytokines. These mechanisms include a decrease in receptor activation and costimulating molecules on the surface of immune cells, as well as the constitutive expression of molecules that inhibit their function, which allow HPV persistence and tumor progression. Immunotherapy-based therapeutic options are positioned as excellent candidates for the treatment of cervical cancer.