Evolving immunosuppressive microenvironment during human cervical carcinogenesis

Chronic infection with human papillomavirus (HPV) can result in cervical cancer. To understand how HPV escapes immune eradication, we examined biophenotypes of immune cells in human normal cervix, cervical intraepithelial neoplasia (CIN), and cancer. Expression and cellular localization of Forkhead box protein-3 (FOXP3), indolamine 2,3-dioxygenase (IDO), interleukin (IL)-10, and interferon (IFN)-γ were examined by immunofluorescence and immunohistochemistry. Mean cell densities of stromal FOXP3+ cells, IDO+ cells, IL-10+ cells, CD1a+ cells, and macrophages significantly increased from normal cervix to cancer, whereas densities of IFN-γ+ and MMP-9+ cells increased from normal cervix to CIN but decreased in cancer. Flow cytometry confirmed significant elevation of cervical T cells expressing IFN-γ and transforming growth factor-β in CIN compared with normal cervix. Upon activation, a significantly increased proportion of cervical T cells expressed IFN-γ in CIN than normal. A unique subset of morphologically immature stromal dendritic cells expressing IL-10 and IDO was more numerous in cancer than in normal cervix and CIN. The potentially suppressive immune milieu in the cervix may be permissive of HPV-associated cervical carcinogenesis.     

Insulin-like growth factor-binding protein 3 expression increases during immortalization of cervical keratinocytes by human papillomavirus type 16 E6 and E7 proteins

Human papillomaviruses (HPVs) infect cervical epithelial cells and induce both benign and precancerous lesions. High-risk HPVs promote the development of cervical cancer in vivo and can immortalize cervical epithelial cells in vitro, whereas low-risk HPVs cannot. We used cDNA microarrays and quantitative polymerase chain reaction to compare cellular gene expression in primary cervical epithelial cells during a time course after retroviral transduction with either low-risk or high-risk E6/E7 genes. At early passages, cervical cells transduced with high-risk E6/E7 genes demonstrated increased expression of the cell cycle-regulated genes CDC2 and ubiquitin carrier E2-C. At later passages, these same cells exhibited dramatic increases in insulin-like growth factor-binding protein-3 (IGFBP-3) mRNA and both secreted an intracellular protein, with mRNA levels increasing approximately 85-fold. Corroborating these in vitro studies, in situ hybridization of cervical biopsies with an IGFBP-3 riboprobe revealed high levels of expression in high-grade squamous intraepithelial neoplasia but not in normal cervical epithelium. Our in vitro results indicate that overexpression of IGFBP-3 is a late event after E6/E7 expression, and analysis of cervical lesions indicates that overexpression of this gene is also seen in vivo.     

Divergent expression of L-type amino acid transporter 1 during uterine cervical carcinogenesis

L-type amino acid transporter 1 (LAT1) is a Na?-independent neutral amino acid transporter that has an essential role in cell proliferation. Although LAT1 expression is observed in various tumor cell lines and immunohistochemical expression of LAT1 has been investigated in carcinomas of various organs, LAT1 expression in uterine cervical neoplasm has not been reported. Therefore, in the present study, we immunohistochemically analyzed LAT1 expression along with the well-known markers of cervical carcinogenesis Ki-67 and p16 in normal uterine cervical mucosa (49 specimens) as well as cervical intraepithelial neoplasia (17 mild or moderate dysplasias and 19 severe dysplasias or carcinomas in situ) and invasive carcinomas (17 squamous cell carcinomas and 9 adenocarcinomas). LAT1 expression was limited to the basal layer of normal squamous epithelium, and it was significantly decreased in cervical intraepithelial neoplasia (P < .001), generally paralleled by increased expression of Ki-67 and p16. Interestingly, in invasive squamous cell carcinoma, LAT1 expression again increased especially at the invasive fronts (P < .001), whereas Ki-67 and p16 expressions were almost unchanged relative to noninvasive neoplasia. Although virtually no LAT1 expression was demonstrated in normal uterine cervical glands, LAT1 expression was observed in some adenocarcinomas (P < .001). The present study suggests that LAT1 expression decreases because of human papillomavirus infection as reflected by p16 overexpression in cervical intraepithelial neoplasia, whereas LAT1 expression in invasive carcinoma is associated with acquired malignant potential.     

P53 immunohistochemical expression: messages in cervical carcinogenesis

AIMS: The pattern of p53 expression was studied in pre-invasive and invasive cervical carcinoma in an attempt to clarify its role in cervical carcinogenesis. METHODS: A total of 234 invasive cervical carcinomas (152 squamous cell carcinomas, 61 adenocarcinomas and 21 adenosquamous carcinomas) and 16 cervical intraepithelial neoplasia (CIN) I, six CIN II and 25 CIN III were immunohistochemically studied for p53. RESULTS: p53 was detected more frequently in CIN and invasive carcinoma (100% of CIN I, 74.2% CIN II + III and 70.1% invasive carcinoma) compared with benign cervices (P< 0.001); however, only three squamous cell carcinomas, 11 adenocarcinomas and two adenosquamous carcinomas exhibited p53 expression in >75% of tumour nuclei. Six of the 11 adenocarcinomas and both adenosquamous carcinomas were poorly differentiated compared with one of the three squamous carcinomas. p53 immunoreactive cells were randomly distributed in invasive carcinoma, confined to the lower third of the epithelium in CIN I, reached the middle third in 20% of CIN II and upper third in 16.6% of CIN III. CONCLUSIONS: Assuming that p53 immunoreactivity indicates gene mutation when the majority (> 75%) of neoplastic cells express p53, p53 mutations would seem uncommon in cervical carcinogenesis. Nonetheless, glandular malignancies, in particular poorly differentiated variants, may show a higher frequency of mutation. p53 was detected more frequently in CIN I compared with CIN II/III and invasive carcinoma which may be due to p53 protein degradation following interaction with high risk human papillomavirus E6 protein in CIN II/III and invasive carcinoma.     

Down-regulation of CXCR4 expression on human CD8+ T cells during peripheral differentiation

Multi-color flow cytometric analysis on human CD8(+) T cell subsets revealed that CXCR4 is predominantly expressed on CD8(+) T cells with the naive CD27(+)CD28(+)CD45RA(+) phenotype, and is down-regulated during differentiation into those with an effector phenotype. The down-regulation of CXCR4 expression during peripheral differentiation was supported by the fact that the expression of CXCR4 on CD8(+) T cells was negatively correlated with that of perforin. The analysis of CCR5, CCR7, and CXCR4 co-expression further showed that CD8(+) T cells expressing a high level of CXCR4 are CCR7(+)CCR5(-) naive or central memory subsets, and those expressing a low level of CXCR4 were included in the CCR7(-)CCR5(+/-) memory/effector and effector subsets. Epstein Barr virus-specific CD8(+) T cells, which mostly express the memory phenotype, expressed CXCR4, while human cytomegalovirus-specific CD8(+) T cells, which mostly express the effector phenotype, partially expressed this receptor, showing that the expression of CXCR4 is also down-regulated during differentiation of viral antigen-specific CD8(+) T cells. The classification of human CD8(+) T cells based on the expression of these chemokine receptors should prove useful for studies that clarify the differentiation of human CD8(+) T cells.     

P21蛋白表达与正常宫颈组织癌变关系的meta分析

目的 系统评价P21蛋白表达与宫颈组织癌变的关系.方法 以关键词"P21waf1、宫颈癌/Cervical Neoplasms"检索数据库Pubmed、Web of Science、Medline、CBMdisc、CNKI、维普中文期刊、万方数据,检索时间自建库至2020年5月,然后运用Revman5.3软件对研究进行...     

Low expression of long non-coding RNA LET inhibits carcinogenesis of cervical cancer

Introduction: Long non-coding RNAs (lncRNAs) have been demonstrated to play key roles in tumorgenesis, and the lncRNA LET is down-regulated in several cancers. However, little is known about the function of lncRNA LET in human cervical cancer. The aim of this study was to investigate the clinical significance of lncRNA LET expression in cervical cancer. Methods: We examined the expression of lncRNA LET in 94 cervical cancer tissues and matched adjacent non-tumor tissues using quantitative real-time PCR and analyzed its correlation with the clinicopathological features. Results: The results showed that lncRNA LET expression in cervical cancer tissues was significantly down-regulated compared with the adjacent non-tumor tissues (P < 0.05). Decreased lncRNA LET expression was significantly correlated with FIGO stage, lymph node metastasis, and depth of cervical invasion (P < 0.05), but not other clinical characteristics. Moreover, cervical cancer patients with lncRNA LET lower expression have shown significantly poorer overall survival than those with higher lncRNA LET expression (P < 0.05). Univariate and multivariate analyses suggested that lncRNA LET expression served as an independent predictor for overall survival. Conclusions: Our data provided the first evidence that lncRNA LET may represent a prognostic marker and a potential therapeutic target for cervical cancer.     

HPV-18 immortalization of human keratinocytes

The oncogenic potential of human papillomavirus type 18 which is found in a significant number of cervical and penile cancer biopsies was tested in primary human keratinocytes derived from neonatal foreskin. Viral DNA and a gene for resistance to neomycin were introduced into these cells by calcium phosphate transfection. Selection of cells in G418 led to the isolation of resistant colonies which were propagated in culture. Four cell lines termed FE-A, FEH 18L, FEP18-5, and FEP18-11 have been maintained in culture for 1 1/2-2 years and were selected for further analysis. In all cases the viral DNA was integrated into the cellular genome and the early genes were transcribed, including RNA complementary to the E2, E6, and E7 open reading frames. Radioimmunoprecipitation showed that all cell lines synthesized the E6 and E7 proteins. However, none of the cell lines tested were tumorigenic. The differentiation capacity of these cells was analyzed by assessing their ability to proliferate clonally after exposure to 1.2 mM calcium chloride. All four cell lines were resistant to this stimulus and formed colonies upon return to regular growth medium whereas normal cells differentiated terminally. K6a and K14 keratin RNA expression was down-regulated in the HPV immortalized cell lines compared to primary human epithelial cells.