No abstract

The present study aims to investigate the expression levels of two critical mammalian target of rapamycin (mTOR) downstream effectors, 4E binding protein 1 (4EBP1) and eukaryotic initiation factor 4E (eIF4E) proteins, in precancerous squamous intraepithelial lesions and cancer of the uterine cervix, and their association with human papilloma virus (HPV) infection status. Uterine cervical biopsies from 73 patients were obtained, including 40 fresh-frozen samples and 42 archival formalin-fixed, paraffin-embedded tissue specimens. Whole protein extracts were analyzed for the expression of 4EBP1 and eIF4E proteins using western blotting. In addition, distribution of 4EBP1 and eIF4E protein expression and 4EBP1 phosphorylation (P-4EBP1) were analyzed by immunohistochemistry in archival tissues and correlated with the degree of dysplasia. The presence of high-risk HPV (HR-HPV) types was assessed by polymerase chain reaction. Using western blot analysis, high expression levels of 4EBP1 and eIF4E were observed in all uterine cervical carcinomas, which significantly correlated with the degree of dysplasia. By immunohistochemistry, overexpression of 4EBP1 and eIF4E was detected in 20 of 21 (95%) and 17 of 21 (81%) samples, respectively, in patients with high-grade dysplasia and carcinomas, compared with 1 of 20 (5%) and 2 of 20 (10%) samples, respectively, in patients with low-grade lesions or normal histology. All 4EBP1-positive cases tested were also positive for P-4EBP1. Furthermore, overexpression of 4EBP1 and eIF4E significantly correlated with the presence of HR-HPV oncogenic types. The present study demonstrated that critical effectors of mTOR signaling, which control protein synthesis initiation, are overexpressed in cervical high-grade dysplasia and cancer, and their levels correlate with oncogenic HPV types. These findings may provide novel targets for investigational therapeutic approaches in patients with cancer of the uterine cervix.

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains of heparan sulfate proteoglycans, the major proteoglycans in the extracellular matrix and cell surfaces. Traditionally, heparanase activity was implicated in cellular invasion associated with angiogenesis, inflammation, and cancer metastasis. More recently, heparanase up-regulation was documented in an increasing number of primary human tumors. Iotan this study, we sought to investigate the expression of heparanase messenger RNA (mRNA) in normal cervical tissue and intraepithelial cervical lesion and its clinicopathologic importance in invasive cervical cancer. Gene expression of heparanase was assessed by quantitative real-time reverse transcriptase polymerase chain reaction in 28 normal cervical, 26 intraepithelial neoplastic, and 48 cervical cancer tissue samples. Heparanase mRNA expression was different between the 3 groups and lower in normal cervical specimens in relationship with intraepithelial cervical lesions and invasive cervical cancer tissue samples (P = 0.048). Gradually increasing expression of heparanase was evident as the cells progressed from low-grade to high-grade squamous intraepithelial lesions (P = 0.002). In invasive cervical cancer cases, there was a direct correlation between heparanase expression and tumor size (P = 0.002). In cases treated with radical hysterectomy and pelvic lymphadenectomy, the heparanase mRNA expression was significantly higher in tumors exhibiting lymph vascular space invasion (P = 0.044) and in cases with big tumor size (P = 0.005). In our study, we did not find any significant correlation between disease-free and overall survival rates and expression of heparanase (P = 0.396 and P = 0.712, respectively). The results of this study suggest that the gene expression of heparanase in cervical cancer enhances growth, invasion, and angiogenesis of the tumor and may have therapeutic applications.

Fifty biopsies from high-grade squamous intraepithelial lesions (HG-SIL) and 14 cervical carcinoma biopsies from Greek women were screened for the presence of human papillomavirus (HPV) DNA sequences by Southern blot hybridization and by the polymerase chain reaction (PCR) for the presence of different HPV types. In high-grade SIL, HPV DNA sequences were detected in 44 of 50 biopsies with the following distribution: 36% HPV 16, 12% HPV 18, 6% HPV 31, 6% HPV 33, 4% HPV 51, and 24% unclassified HPV types. In cervical carcinoma biopsies, 13 of 14 specimens were positive for HPV DNA sequences. Six biopsies were positive for HPV 16, three were positive for HPV 18, and four contained unclassified HPV types. Overall, of the total 64 biopsies, 57 (89%) were positive for HPV DNA sequences. Of these, Southern blot hybridization alone detected HPV DNA sequences in 39 cases, whereas by PCR 18 additional specimens were found to be positive for HPV. Among the HPV 16-positive biopsies, two samples produced a Pstl banding pattern very similar but not identical to that of HPV 16 prototype and were referred to as HPV 16 isolates. One HPV 16 isolate appears to carry a mutation within the carboxy-terminal half of the L2 gene that results in the loss of a Pstl site. The other HPV 16 isolate had a similar Pstl banding pattern to that previously reported as HPV 16 "variant" found in Cape Town [Williamson et al., 1989, Journal of Medical Virology 28: 146-149, 1994, Journal of Medical Virology 43: 231-237.] and in Italy [Li Vigni et al., 1994, 2nd International Congress of Papillomavirus in Human Pathology (Abstracts), p 100.].