Alterations in the expression and activity of extracellular matrix components in HPV-associated infections and diseases

Infection with human papillomaviruses is associated with a series of benign and malignant hyperproliferative diseases that impose a heavy burden on human populations. A subgroup of mucosal human papillomavirus types are associated with the majority of cervical cancers and a relevant fraction of vulvar, vaginal, anal, penile and head and neck carcinomas. Human papillomaviruses mediate cell transformation by the expression of two pleiotropic oncoproteins that alter major cellular regulatory pathways. However, these viruses are not complete carcinogens, and further alterations within the infected cells and in their microenvironment are necessary for tumor establishment and progression. Alterations in components of the extracellular matrix for instance, matrix metalloproteinases and some of their regulators such as tissue inhibitors of metalloproteinases, have been consistently reported in human papillomaviruses-associated diseases. Matrix metalloproteinases function by remodeling the extracellular matrix and alterations in their expression levels and/or activity are associated with pathological processes and clinical variables including local tumor invasion, metastasis, tumor relapse and overall patient prognosis and survival. In this review we present a summarized discussion on the current data concerning the impact of human papillomavirus infection on the activity and expression of extracellular matrix components. We further comment on the possibility of targeting extracellular matrix molecules in experimental treatment protocols

Human polyomaviruses and cancer: an overview

The name of the family Polyomaviridae, derives from the early observation that cells infected with murine polyomavirus induced multiple (poly) tumors (omas) in immunocompromised mice. Subsequent studies showed that many members of this family exhibit the capacity of mediating cell transformation and tumorigenesis in different experimental models. The transformation process mediated by these viruses is driven by viral pleiotropic regulatory proteins called T (tumor) antigens. Similar to other viral oncoproteins T antigens target cellular regulatory factors to favor cell proliferation, immune evasion and downregulation of apoptosis. The first two human polyomaviruses were isolated over 45 years ago. However, recent advances in the DNA sequencing technologies led to the rapid identification of additional twelve new polyomaviruses in different human samples. Many of these viruses establish chronic infections and have been associated with conditions in immunosuppressed individuals, particularly in organ transplant recipients. This has been associated to viral reactivation due to the immunosuppressant therapy applied to these patients. Four polyomaviruses namely, Merkel cell polyomavirus (MCPyV), Trichodysplasia spinulosa polyomavirus (TSPyV), John Cunningham Polyomavirus (JCPyV) and BK polyomavirus (BKPyV) have been associated with the development of specific malignant tumors. However, present evidence only supports the role of MCPyV as a carcinogen to humans. In the present review we present a summarized discussion on the current knowledge concerning the role of MCPyV, TSPyV, JCPyV and BKPyV in human cancers

Study of the control of RECK gene expression by human papillomavirus oncoproteins.

O desenvolvimento do câncer cervical está associado à infecção persistente por alguns tipos de papilomavírus humano (HPV). Entre os mecanismos de carcinogênese associados ao HPV incluem-se alterações em componentes da matriz extracelular (MEC), como as metaloproteinases de matriz (MMP) e alguns de seus reguladores negativos como a proteína supressora de tumor RECK (do inglês REversion-inducing Cysteine-rich protein with Kazal motifs). Resultados publicados previamente por nosso grupo apontam para a correlação entre a expressão da oncoproteína E7 de HPV16, a alta expressão e atividade de MMP-9 e a baixa expressão da proteína RECK. A expressão de RECK também é baixa em lesões do colo uterino de alto grau e em amostras de câncer cervical, quando comparadas a amostras de pacientes com cervicite. O presente estudo visou compreender o mecanismo de regulação da expressão do gene RECK por oncoproteínas de papilomavírus humano. Para isto, realizamos ensaios de gene repórter com construções contendo diferentes regiões do promotor do gene RECK em células que expressem as oncoproteínas E6 e E7 de HPV de alto e baixo risco oncogênico. Observamos que a atividade do promotor de RECK é regulada negativamente pela expressão de E6 e E7 de HPV11 e HPV16. Além disso, analisamos in silico as regiões do promotor clonadas e verificamos a presença de sítios de ligação para fatores de transcrição regulados proteínas de HPV. Em conjunto, nossos dados mostram, pela primeira vez, a regulação da atividade do promotor do gene RECK por proteínas do HPV.The development of cervical cancer is associated with human papillomavirus (HPV) persistent infection. The HPV carcinogenic mechanisms include alterations in extracellular matrix (ECM) components, as matrix metalloproteinases (MMP) and its regulators such as the tumor suppressor RECK protein (REversion-inducing Cysteine-rich protein with Kazal motifs). Previous results published by our group point to the correlation among oncoprotein expression HPV16 E7, high activity expression of MMP-9 and low expression of RECK protein. RECK expression is also low in high-grade cervical squamous intraepithelial lesion and cervical cancer samples, when compared with with cervicitis. The present study aimed to understand the mechanisms associated with HPV E6 and E7 oncoprotein regulation of the RECK gene promoter. In order to do so, we transfected HEK293 cells (expressing or not HPV11 or HPV16 E6 and/or E7) with different RECK gene promoter constructions and performed gene reporter assays. We observed that HPV11 or HPV16 E6 and E7 expression is associated with lower RECK promoter activity. Moreover, we explored the potential transcriptional factors binding sites in the RECK gene promoter using in silico data. We found several binding sites for transcription factors that can be modulated by HPV E6 and E7 oncoproteins, such as p53, pRb, E2F, c-fos, c-jun ans Sp1. Altogether, our data show, for the first time, that HPV E6 and E7 regulate the RECK gene promoter activity regulation

Alterations in the expression and activity of extracellular matrix components in HPV-associated infections and diseases

Infection with human papillomaviruses is associated with a series of benign and malignant hyperproliferative diseases that impose a heavy burden on human populations. A subgroup of mucosal human papillomavirus types are associated with the majority of cervical cancers and a relevant fraction of vulvar, vaginal, anal, penile and head and neck carcinomas. Human papillomaviruses mediate cell transformation by the expression of two pleiotropic oncoproteins that alter major cellular regulatory pathways. However, these viruses are not complete carcinogens, and further alterations within the infected cells and in their microenvironment are necessary for tumor establishment and progression. Alterations in components of the extracellular matrix for instance, matrix metalloproteinases and some of their regulators such as tissue inhibitors of metalloproteinases, have been consistently reported in human papillomaviruses-associated diseases. Matrix metalloproteinases function by remodeling the extracellular matrix and alterations in their expression levels and/or activity are associated with pathological processes and clinical variables including local tumor invasion, metastasis, tumor relapse and overall patient prognosis and survival. In this review we present a summarized discussion on the current data concerning the impact of human papillomavirus infection on the activity and expression of extracellular matrix components. We further comment on the possibility of targeting extracellular matrix molecules in experimental treatment protocols

Human polyomaviruses and cancer: an overview

The name of the family Polyomaviridae, derives from the early observation that cells infected with murine polyomavirus induced multiple (poly) tumors (omas) in immunocompromised mice. Subsequent studies showed that many members of this family exhibit the capacity of mediating cell transformation and tumorigenesis in different experimental models. The transformation process mediated by these viruses is driven by viral pleiotropic regulatory proteins called T (tumor) antigens. Similar to other viral oncoproteins T antigens target cellular regulatory factors to favor cell proliferation, immune evasion and downregulation of apoptosis. The first two human polyomaviruses were isolated over 45 years ago. However, recent advances in the DNA sequencing technologies led to the rapid identification of additional twelve new polyomaviruses in different human samples. Many of these viruses establish chronic infections and have been associated with conditions in immunosuppressed individuals, particularly in organ transplant recipients. This has been associated to viral reactivation due to the immunosuppressant therapy applied to these patients. Four polyomaviruses namely, Merkel cell polyomavirus (MCPyV), Trichodysplasia spinulosa polyomavirus (TSPyV), John Cunningham Polyomavirus (JCPyV) and BK polyomavirus (BKPyV) have been associated with the development of specific malignant tumors. However, present evidence only supports the role of MCPyV as a carcinogen to humans. In the present review we present a summarized discussion on the current knowledge concerning the role of MCPyV, TSPyV, JCPyV and BKPyV in human cancers

Low RECK Expression Is Part of the Cervical Carcinogenesis Mechanisms

Human papillomavirus (HPV)-induced carcinogenesis comprises alterations in the expression and activity of matrix metalloproteinases (MMP) and their regulators. Reversion-inducing Cysteine-rich protein with Kazal motifs (RECK) inhibits the activation of specific metalloproteinases and its expression is frequently lost in human cancers. Here we analyzed the role of RECK in cervical carcinogenesis. Cervical cancer derived cell lines over expressing RECK were used to determine tumor kinetics as well as, cellular, immune and molecular properties in vivo. Besides, we analyzed RECK expression in cervical cancer samples. RECK over expression (RECK+) delayed tumor growth and increased overall survival in vivo. RECK+ tumors displayed an increase in lymphoid-like inflammatory infiltrating cells, reduced number and viability of tumor and endothelial cells and lower collagenase activity. RECK+ tumors exhibited an enrichment of cell adhesion processes both in the mouse model and cervical cancer clinical samples. Finally, we found that lower RECK mRNA levels were associated with cervical lesions progression and worse response to chemotherapy in cervical cancer patients. Altogether, we show that increased RECK expression reduced the tumorigenic potential of HPV-transformed cells both in vitro and in vivo, and that RECK down regulation is a consistent and clinically relevant event in the natural history of cervical cancer