Investigation of the relationship between HPV positivity and osteopontin level in cervical tissues

Introduction and Aim: Cervical cancer is the second most common cancer in women after breast cancer. HPV is a double-stranded DNA virus of icosahedral symmetry belonging to the papillomaviridae family. HPV is the major etiologic agent of cervical cancer. OPN, an extracellular matrix molecule, is a cytokine-like phosphoglycoprotein rich in sialic acid. It has been reported that OPN is released at high rates in various malignancies. This study aimed to investigate the OPN levels in HPV-positive and HPV-negative cervical tissues and evaluate its clinical significance as a prognostic biomarker. Material and Method: A total of 82 individuals that referred to the Polyclinic of Obstetrics and Gynecology of Erzincan University, Turkey and underwent cervical cancer screening between June 2015 and April 2017 were included in the study. Cervicovaginal swabs were collected according to the standard procedure. A slide for traditional Pap cytology was prepared and stained according to standard protocols, and the results were categorized according to the 2004 Bethesda classification system. All cervical samples were analyzed in terms of the presence or absence of 13 high-risk HPV genotypes (HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68) using the digene® HC2 high-risk HPV DNA test (Qiagen, Gaithersburg, MD, USA) according to the manufacturer's recommendation. Colposcopy, endocervical abortion, and cervical biopsy were performed on women that were HPV-positive. The tissue samples of 41 HPV-positive patients and 41 HPV-negative control patients that underwent surgery for benign gynecologic reasons were histopathologically examined, and the OPN levels in these samples were investigated by an ELISA kit (Hangzhou Eastbiopharm Co., Ltd, China) according to the manufacturer's recommendation. SPSS software v. 20 was used for the statistical analysis of data. Results: The mean age of the study population (41 patients and 41 healthy controls) was 46.76 ± 10.1 years; 43.88 ± 9.2 years in the patient group and 49.63 ± 10.3 years in the control group. The OPN values were found to be 31.55 ± 7.11 and 28.81 ± 5.44 in the patient and control groups, respectively. The OPN levels in HPV-positive cervical tissues were statistically significantly higher compared to the control group (p = 0.048). There was no statistically significant difference between the OPN level and age, delivery method, history of disease, surgical method, HPV type, preoperative and postoperative pathology, gravida and parity (p > 0.05). In both patient and control groups, the OPN values statistically significantly differed between working women and homemakers (p = 0.029). Furthermore, the OPN levels were statistically significantly higher (p = 0.025) among the patients with a history of three and more full-term pregnancies compared to the control group. CIN was detected in five (12.2%) of 41 HPV-positive patients. Conclusion: The detection of CIN in only five of 41-HPV positive patients constitutes a limitation of this study. Although the level of OPN was high in HPV-positive patients, we consider that there is a need for further studies on a larger number of CIN cases. Keywords: Cervical Cancer, ELISA, Human Papilloma Virus (HPV), Osteopontin