Abnormal cell-cycle expression of the proteins p27, mdm2 and cathepsin B in oral squamous-cell carcinoma infected with human papillomavirus

Therapeutic strategy for oncovirus-mediated oral cancer: A comprehensive review

Oral cancer is a neoplastic disorder of the oral cavities, including the lips, tongue, buccal mucosa, and lower and upper gums. Oral cancer assessment entails a multistep process that requires deep knowledge of the molecular networks involved in its progression and development. Preventive measures including public awareness of risk factors and improving public behaviors are necessary, and screening techniques should be encouraged to enable early detection of malignant lesions. Herpes simplex virus (HSV), human papillomavirus (HPV), Epstein-Barr virus (EBV), and Kaposi sarcoma-associated herpesvirus (KSHV) are associated with other premalignant and carcinogenic conditions leading to oral cancer. Oncogenic viruses induce chromosomal rearrangements; activate signal transduction pathways via growth factor receptors, cytoplasmic protein kinases, and DNA binding transcription factors; modulate cell cycle proteins, and inhibit apoptotic pathways. In this review, we present an up-to-date overview on the use of nanomaterials for regulating viral proteins and oral cancer as well as the role of phytocompounds on oral cancer. The targets linking oncoviral proteins and oral carcinogenesis were also discussed.

Prevalence of oral and oropharyngeal human papillomavirus infection in Brazilian population studies: a systematic review

Introduction

Human papillomavirus has been associated with head and neck squamous cell carcinoma. However, there is no conclusive evidence on the prevalence of oral or pharyngeal infection by human papillomavirus in the Brazilian population.

Objective

To determine the rate of human papillomavirus infection in the Brazilian population.

Methods

Systematic review of published articles. Medline, The Cochrane Library, Embase, Lilacs (Latin American and Caribbean Health Sciences) and Scielo electronic databases were searched. The search included published articles up to December 2014 in Portuguese, Spanish and English. A wide search strategy was employed in order to avoid publication biases and to assess studies dealing only with oral and/or oropharyngeal human papillomavirus infections in the Brazilian population.

Results

The 42 selected articles enrolled 4066 patients. It was observed that oral or oropharyngeal human papillomavirus infections were identified in 738 patients (18.2%; IC 95 17.6–18.8), varying between 0.0% and 91.9%. The prevalences of oral or oropharyngeal human papillomavirus infections were respectively 6.2%, 44.6%, 44.4%, 27.4%, 38.5% and 11.9% for healthy people, those with benign oral lesions, pre-malignant lesions, oral or oropharyngeal squamous cell carcinoma, risk groups (patients with genital human papillomavirus lesions or infected partners) and immunocompromised patients. The risk of human papillomavirus infection was estimated for each subgroup and it was evident that, when compared to the healthy population, the risk of human papillomavirus infection was approximately 1.5–9.0 times higher, especially in patients with an immunodeficiency, oral lesions and squamous cell carcinoma. The rates of the most well-known oncogenic types (human papillomavirus 16 and/or 18) also show this increased risk.

Conclusions

Globally, the Brazilian healthy population has a very low oral human papillomavirus infection rate. Other groups, such as at-risk patients or their partners, immunocompromised patients, people with oral lesions and patients with oral cavity or oropharyngeal squamous cell carcinoma have a high risk of human papillomavirus infection.

Human papillomavirus early proteins and apoptosis

INTRODUCTION

The human papillomavirus (HPV) associated apoptosis can be primarily attributed to some early proteins, such as E2, E5, E6, E7, and so on. Though these proteins have a low molecular size, they are capable to interact with a series of host cellular regulation proteins to induce or inhibit apoptosis. The oncoproteins E6 can inhibit the apoptosis mainly through p53 pathway. The E5 protein can protect cells from tumor necrosis factor-related apoptosis. The protein E2 protein have regulatory functions in viral transcription and induction of apoptosis. The oncoprotein E7 plays the role in both apoptosis activation and inhibition. In addition, the HPV full-length E2 proteins involve in activating or repressing the transcription of E6/E7, so as to regulating the apoptosis caused by E6 and E7.

MATERIALS AND METHODS

We search major databases (such as Elsevier) with the following selection criteria: HPV, early protein, apoptosis.

CONCLUSIONS

In this review, we summary the literature related with E2, E5, E6, and E7 proteins, and describe the regulatory principles and specific mechanism by which HPV early proteins can interfere with apoptosis and trigger gynaecopathias for women.

The role of human papillomavirus in oral squamous cell carcinoma: myth and reality

INTRODUCTION

As the traditional risk factors for oral squamous cell carcinoma, especially tobacco, decline, new potential causative agents become the focus of research. Since the discovery of human papillomavirus (HPV) and its importance in carcinogenesis in cervical cancer, a lot of research has been undertaken to define its role in different types of cancer. In the present study, we evaluate the role of high-risk HPV types in initiation and progression of oral squamous cell carcinoma (OSCC) using a systematic review of the current literature.

MATERIAL AND METHODS

A literature research with the search term "HPV oral squamous cell carcinoma" was performed via PubMed. Results were screened systematically for relevance and classified into the following categories: molecular biology, genetics, clinical aspects, and prevalence. Articles were then further analyzed to assess quality.

RESULTS

The literature research led to 527 results, with an overall HPV prevalence of 30.1 % in OSCCs. The most frequently identified subtypes were HPV-16 and HPV-18 (25.4 and 18.1 %, respectively). Prognostic relevance of HPV was discussed controversially. HPV detection via polymerase chain reaction is the most established method today. Molecular changes according to carcinogenic pathways described for cervix carcinoma were not routinely found in OSCC. In general, no definite role of high-risk HPV is currently deducible from the literature.

CONCLUSIONS

High-risk subtypes 16 and 18 are present in the genome in approximately one third of OSCC. Its role as a causative agent is less clear than the role in oropharyngeal tumors. The infection might not be the cause of carcinogenesis in a significant number of patients but may become proportionally more important with the decrease of the classical risk factors of tobacco and alcohol.

Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma

The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens.