ABSTRACT
PURPOSE: Evaluate the presence of human papillomavirus (HPV) in biopsies of Brazilian patients with lung cancer and also the expression of the E6 and E7 oncoproteins. HPV is widely known as an important condition for cervical cancer although evidence today shows it is associated with several other types of cancer and may also be involved in lung cancer development. However, there are some divergences regarding the presence and activity of HPV in lung carcinogenesis. METHODS: The detection of HPV was performed by PCR, followed by genotype and immunohistochemical evaluation of E6 and E7 HPV type specific, from 63 patients. RESULTS: HPV was found to be present in 33 of the 63 samples, and types 16 and 18 were detected with frequencies of 81% (27/33) and 19% (6/33), respectively. About the presence of the virus in different histological types of tumors, HPV was detected in squamous cell carcinoma (39.39%), followed by adenocarcinoma (33.33%) and small cell carcinoma (18.18%) and large cell carcinoma (9.1%). The presence of the E6 (antibody anti-HPV 16 and anti-HPV 18) and E7 (antibody anti-HPV 16 and anti-HPV 18) oncoproteins was detected by immunohistochemical stain technique in 28/33 samples and 25/33 samples, respectively. CONCLUSIONS: Our results suggest that the lung tumor patients have high prevalence of HPV and the virus is not only present but also active in tumor cells. Therefore, the HPV is probably playing a role in lung carcinogenesis.
Subject(s)
Lung Neoplasms/etiology , Papillomaviridae , Papillomavirus Infections/complications , Papillomavirus Infections/virology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Immunohistochemistry , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Male , Middle Aged , Oncogene Proteins, Viral/genetics , Oncogene Proteins, Viral/metabolism , Papillomaviridae/classification , Papillomaviridae/genetics , Papillomavirus E7 Proteins/genetics , Papillomavirus E7 Proteins/metabolism , Young AdultABSTRACT
Lung cancer is the most common cause of cancer deaths worldwide. Although tobacco smoking is considered to be the main risk factor and the most well-established risk factor for lung cancer, a number of patients who do not smoke have developed this disease. This number varies between 15 % to over one-half of lung cancer cases, and the deaths from lung cancer in non-smokers are increasing every year. There are many other agents that are thought to be etiological, including diesel exhaust exposure, metals, radiation, radon, hormonal factors, cooking oil, air pollution and infectious diseases, such as human papillomavirus (HPV). Studies in various parts of the world have detected HPV DNA at different rates in lung tumors. However, the role of HPV in lung cancer is still unclear. Thus, in this review, we investigated some molecular mechanisms of HPV protein activity in host cells, the entry of HPV into lung tissue and the possible route used by the virus to reach the lung cells.
