Increased vascular endothelial growth factor expression, CD3-positive cell infiltration, and oxidative stress in premalignant lesions of the cervix

Fermented Mangosteen (Garcinia mangostana L.) Supplementation in the Prevention of HPV-Induced Cervical Cancer: From Mechanisms to Clinical Outcomes

Simple Summary

Human papillomavirus (HPV) is connected with virtually all cases of cervical cancer. The viral infection-associated chronic inflammation, oxidative stress, and alterations in apoptosis have been considered as leading risk factors for carcinogenesis in humans. In an observational clinical study, we identified oxidative markers and the cervical/circulating ligands of TNF-alpha-induced apoptosis involved in HPV-associated cervical carcinogenesis. In the following clinical trial, 250 females infected with high-cancer-risk HPV16/18 (healthy and pre-cancerous) were recruited into a placebo-controlled clinical study of supplementation with fermented mangosteen (FM, 28g/day, daily) for three months. Our findings indicate that FM, and not a placebo, in combination with routine anti-viral therapy, could prevent, slow down, or even interrupt HPV-associated cervical carcinogenesis, mainly through the suppression of leukocyte recruitment into infected tissue, through anti-inflammatory effects, and through the restoration of nitric oxide metabolite-initiated TRAIL-dependent apoptosis.

Abstract

In the observational clinical study, we identified the oxidative markers of HPV-associated cervical carcinogenesis and the local/circulating ligands of TNF-alpha-induced apoptosis. Cervical biopsies of 196 females infected with low-cancer-risk HPV10/13 or high-cancer-risk HPV16/18 (healthy, pre-cancerous CIN I and CIN II, and CIN III carcinoma) were analysed for OH radical scavenging, catalase, GSH-peroxidase, myeloperoxidase (MPO), nitrate/nitrite, nitrotyrosine, and isoprostane. Ligands of TNF-alpha-dependent apoptosis (TNF-alpha, TRAIL, IL-2, and sFAS) were determined in cervical fluid, biopsies, and serum. Cervical MPO was highly enhanced, while nitrotyrosine decreased in CIN III. Local/circulating TRAIL was remarkably decreased, and higher-than-control serum TNF-alpha and IL-2 levels were found in the CIN I and CIN III groups. Then, 250 females infected with HPV16/18 (healthy and with CIN I and CIN II) were recruited into a placebo-controlled clinical study of supplementation with fermented mangosteen (FM, 28g/day, daily) for three months. Post-trial colposcopy revealed normal patterns in 100% of the FM group versus 62% of the placebo group. Inflammatory cells in cervical fluid were found in 21% of the FM group versus 40% of the placebo group. Locally, FM drastically diminished MPO and NO₂/NO₃, while it remarkably increased TRAIL. Additionally, FM supplementation normalised serum TRAIL, TNF-alpha, and IL-2.

In situ immunopathological events in human cervical intraepithelial neoplasia and cervical cancer: Review

Neoplasia of the cervix represents one of the most common cancers in women. Clinical and molecular research has identified immunological impairment in squamous intraepithelial cervical lesions and cervical cancer patients. The in-situ expression of several cytokines by uterine epithelial cells and by infiltrating leukocytes occurs during the cervical intraepithelial neoplasia and cervical cancer. Some of these cytokines can prevent and others can induce the progression of the neoplasm. The infiltrating leukocytes also produce cytokines and growth factors relate to angiogenesis, chemotaxis, and apoptosis capable of modulating the dysplasia progression. In this review we analyzed several interleukins with an inductive effect or blocking effect on the neoplastic progression. We also analyze the genetic polymorphism of some cytokines and their relationship with the risk of developing cervical neoplasia. In addition, we describe the leukocyte cells that infiltrate the cervical uterine tissue during the neoplasia and their effects on neoplasia progression.

Infiltrating CD4 and CD8 lymphocytes in HPV infected uterine cervical milieu

PURPOSE

Tumor infiltrating lymphocytes (TILs) have been extensively described in anti-tumor immunity, but their functional alterations in the immunoediting processes during neoplastic progression in the uterine cervix are still not clear. Our aim was to gain insight into cervical tissue T cell populations, determine if there are any differences in the localization and quantity distribution of T lymphocytes, and to evaluate their role in disease regression or progression in the cervical neoplastic milieu.

PATIENTS AND METHODS

Serial section analysis of immunohistochemically stained CD4 and CD8 lymphocytes was performed on a total number of 72 samples, categorized into four cohorts: 23 HPV non-infected (HPV-) normal cervix, 20 HPV infected (HPV+) normal cervix, 17 HPV+ low grade cervical intraepithelial neoplasia (CIN), and 12 HPV+ high grade CIN.

RESULTS

Low infiltrating lymphocytes (ILs) in normal cervix and high ILs in CIN were observed, while the trend of ILs increased with increasing grade of CIN, which was statistically significant (P<0.0001). Quantitative and localization analysis between the subsets of T cells showed that, in the epithelial layer, infiltrating CD8+ lymphocytes (CD8+ILs) were significantly higher than CD4+ILs in HPV+ normal cervix, while the trend decreased with increasing grade of CIN (P=0.011). Whereas, in the stromal layer, CD4+ILs were predominant in all study groups and no statistical difference was found between these groups. However, tumor infiltrating CD8+ lymphocytes (CD8+TILs) were noted to be significantly higher than CD4+TILs in severe dysplastic cases.

CONCLUSION

T cell infiltrates were predominant as the grade of the lesion progressed into more advanced lesions, which likely represent the lesions that have persisted over time. The variation in the infiltration rate and the location of CD4+ILs and CD8ILs may suggest the efficacious role of CD8 T cells in eliminating HPV infected cervical epithelial cells and also provides insight into the complex role of TILs in facilitating and mediating sustained anti-tumor responses, hence preventing tumor outgrowth.

In situ expressions of protein 16 (p16CDKN2A) and transforming growth factor beta-1 in patients with cervical intraepithelial neoplasia and cervical cancer

OBJECTIVES

Protein 16 (p16^CDKN2A) and transforming growth factor-beta 1 (TGF- β1) are important tumor suppressor molecules. The aim of this study was to evaluate the frequency and simultaneous expression of p16^CDKN2A and TGF- β1 in cervical intraepithelial neoplasia (CIN) and cervical cancer and their relationship whit the neoplasia progression.

STUDY DESIGN

To evaluate the expressions of p16^CDKN2A and TGF- β1 an immunohistochemical study of both proteins in 75 cervical tissues (24 CIN I, 17 CIN II, 15 CIN III and 19 squamous cell cancer) was performed.

RESULTS

Increased expression of epithelial and stromal p16^CDKN2A in all grades of CIN and cancer was observed. Healthy controls were negative. The frequency of p16^CDKN2A expression in the patients was as follow: 75% in CIN I and 100% in CIN II, CIN III and cancer. TGF- β1 expression was found increased in all patients with CIN I and CIN II and decreased in CIN III and cancer; 60% of patients with CIN III and 16% with cancer showed reactivity for TGF- β1. High intensity of p16^CDKN2A reactivity and low intensity of TGF- β1 reactivity were observed.

CONCLUSIONS

The linear frequency of p16^CDKN2A expression accompanied by decreased frequency of TGF- β1 in CIN III and cancer could be involved in the neoplasia progression.

Murine HPV16 E7-expressing transgenic skin effectively emulates the cellular and molecular features of human high-grade squamous intraepithelial lesions

Currently available vaccines prevent HPV infection and development of HPV-associated malignancies, but do not cure existing HPV infections and dysplastic lesions. Persistence of infection(s) in immunocompetent patients may reflect induction of local immunosuppressive mechanisms by HPV, providing a target for therapeutic intervention. We have proposed that a mouse, expressing HPV16 E7 oncoprotein under a Keratin 14 promoter (K14E7 mice), and which develops epithelial hyperplasia, may assist with understanding local immune suppression mechanisms that support persistence of HPV oncogene-induced epithelial hyperplasia. K14E7 skin grafts recruit immune cells from immunocompetent hosts, but consistently fail to be rejected. Here, we review the literature on HPV-associated local immunoregulation, and compare the findings with published observations on the K14E7 transgenic murine model, including comparison of the transcriptome of human HPV-infected pre-malignancies with that of murine K14E7 transgenic skin. We argue from the similarity of i) the literature findings and ii) the transcriptome profiles that murine K14E7 transgenic skin recapitulates the cellular and secreted protein profiles of high-grade HPV-associated lesions in human subjects. We propose that the K14E7 mouse may be an appropriate model to further study the immunoregulatory effects of HPV E7 expression, and can facilitate development and testing of therapeutic vaccines.

HPV16E7-Induced Hyperplasia Promotes CXCL9/10 Expression and Induces CXCR3+ T-Cell Migration to Skin

Chemokines regulate tissue immunity by recruiting specific subsets of immune cells. Mice expressing the E7 protein of human papilloma virus 16 as a transgene from a keratin 14 promoter (K14.E7) show increased epidermal and dermal lymphocytic infiltrates, epidermal hyperplasia, and suppressed local immunity. Here, we show that CXCL9 and CXCL10 are overexpressed in non-hematopoietic cells in skin of K14.E7 mice when compared with non-transgenic animals, and recruit CXCR3⁺ lymphocytes to the hyperplastic skin. Overexpression of CXCL9 and CXCL10 is not observed in E7 transgenic mice with mutated Rb gene whose protein product cannot interact with E7 (K14.E7xRb^ΔL/ΔL) and in consequence lack hyperplastic epithelium. CXCR3⁺ T cells are preferentially recruited by CXCL9 and CXCL10 in supernatants of K14.E7 but not K14.E7xRb^ΔL/ΔL skin cultures in vitro. CXCR3 signalling promotes infiltration of a subset of effector T lymphocytes that enables donor lymphocyte deficient, E7-expressing skin graft rejection. Taken together, this suggests that recruitment of CXCR3⁺ T cells can be an important factor in the rejection of precancerous skin epithelium providing they can overcome local immunosuppressive mechanisms driven by skin-resident lymphocytes.

[Remodeling of angiogenesis and lymphangiogenesis in cervical cancer development]

Ability to stimulate angiogenesis/lymphangiogenesis is recognized as an inherent feature of cancer cells providing necessary conditions for their growth and dissemination. "Angiogenic switch" is one of the earliest consequences of malignant transformation that encompasses a great number of genes and triggers a complex set of signaling cascades in endothelial cells. The processes of tumor microvasculature development are closely connected to the steps of carcinogenesis (from benign lesions to invasive forms) and occur through multiple deviations from the norm. Analysis of expression of proangiogenic factors at successive steps of cervical cancer development (intraepithelial neoplasia, cancer in situ, microinvasive, and invasive cancer) enables to reconstruct the regulatory mechanisms of (lymph-)angiogenesis and to discriminate the most important components. This review presents detailed analysis of literature data on expression of the key regulators of angiogenesis in cervical intraepithelial neoplasia and cervical cancer. Their possible involvement in molecular mechanisms of neoplastic transformation of epithelial cells, as well as invasion and tumor metastasis is discussed. Correlation between expression of proangiogenic molecular factors and various clinicopathological parameters is considered, the potential of their use in molecular diagnostics and targeted therapy of cervical cancer is reviewed. Particular attention is paid to relatively poorly studied regulators of lymphangiogenesis and "non-VEGF dependent", or alternative, angiogenic pathways that constitute the prospect of future research in the field.

Accumulation of invariant NKT cells with increased IFN-γ production in persistent high-risk HPV-infected high-grade cervical intraepithelial neoplasia

BACKGROUND

Persistent high-risk human papillomavirus (HR-HPV) infection has been implicated in the development of high-grade cervical intraepithelial neoplasia (CIN) and cervical cancer. Invariant natural killer T (iNKT) cells produce large amounts of cytokines to regulate immune responses. However, the role of iNKT cells in human persistent HPV-infected cervical tissues is unknown.

METHODS

In our study, 201 patients with diagnoses ranging from normal ectocervical tissue to CINIII from June 2010 to May 2012 were enrolled. HPV DNA and HPV types were detected using the hybrid capture-2 HPV DNA test. Flow cytometry was used to investigate iNKT and CD3+ T cell infiltration into cervical tissues. Real-time quantitative reverse transcription-polymerase chain reaction was used to study IFN-γ expression and immunohistochemistry was used to determine CD3+ T cell distribution.

RESULTS

A significant increase in iNKT cells was observed in HPV-positive cervical tissues (p < 0.05), especially in CINII-III (p < 0.01). IFN-γ expression was also increased in HPV-positive cervical tissues (p < 0.05). CD3+ T cells were detected among both epithelium and stromal layers in cervical tissues, and the percentage of CD3+ T cells in HPV-positive cervical tissues was similar to that in HPV-negative cervical tissues (p > 0.05).

CONCLUSIONS

The iNKT cell aggregation in cervical tissues during the progression from HPV infection to CIN indicates that iNKT cells might play an important role in suppressing immunity. IFN-γ expression could also be related to the HPV infection status. Preventing the accumulation or functioning of iNKT cells in cervical tissues may be a viable method to prevent the development of CIN.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2521874671514142.

In situ increased chemokine expression in human cervical intraepithelial neoplasia

Chemokines play a role in tumor-inflammation and angiogenesis that could be involved in tumor progression. Monocyte chemoattractant protein-1 (MCP-1), Interleukin-8 (IL-8) and macrophage inflammatory proteins (MIP) have been identified in tumor tissues of patients with different neoplasms. Therefore, the aim of the current study was to investigate the expressions of MCP-1, IL-8 and MIP-1α, mononuclear leukocyte infiltration and leukocyte/chemokine expressions in cervical tissues from patients with cervical intraepithelial neoplasia (CIN) and controls. MCP-1, IL-8 and MIP-1α expressions and leukocyte infiltration were determined by indirect immunofluorescence in cervix biopsies from CIN patients (n=65) and 7 normal controls. Increased expressions of MCP-1 and IL-8 in CIN were observed. Increment of lymphocyte infiltration and coexpression of CD3/MCP-1 and CD3/IL-8 were found in CIN. CD3/MCP-1 cell percentage was found decreased and CD3/IL-8 percentage increased according to the CIN evolution. MIP-1α remained similar to control values. The increased expression of MCP-1 and IL-8 in cervical neoplasia may lead to tumor progression.

Oxidative stress and HPV carcinogenesis

Extensive experimental work has conclusively demonstrated that infection with certain types of human papillomaviruses, the so-called high-risk human papillomavirus (HR-HPV), represent a most powerful human carcinogen. However, neoplastic growth is a rare and inappropriate outcome in the natural history of HPV, and a number of other events have to concur in order to induce the viral infection into the (very rare) neoplastic transformation. From this perspective, a number of putative viral, host, and environmental co-factors have been proposed as potential candidates. Among them oxidative stress (OS) is an interesting candidate, yet comparatively underexplored. OS is a constant threat to aerobic organisms being generated during mitochondrial oxidative phosphorylation, as well as during inflammation, infections, ionizing irradiation, UV exposure, mechanical and chemical stresses. Epithelial tissues, the elective target for HPV infection, are heavily exposed to all named sources of OS. Two different types of cooperative mechanisms are presumed to occur between OS and HPV: I) The OS genotoxic activity and the HPV-induced genomic instability concur independently to the generation of the molecular damage necessary for the emergence of neoplastic clones. This first mode is merely a particular form of co-carcinogenesis; and II) OS specifically interacts with one or more molecular stages of neoplastic initiation and/or progression induced by the HPV infection. This manuscript was designed to summarize available data on this latter hypothesis. Experimental data and indirect evidences on promoting the activity of OS in viral infection and viral integration will be reviewed. The anti-apoptotic and pro-angiogenetic role of NO (nitric oxide) and iNOS (inducible nitric oxide synthase) will be discussed together with the OS/HPV cooperation in inducing cancer metabolism adaptation. Unexplored/underexplored aspects of the OS interplay with the HPV-driven carcinogenesis will be highlighted. The aim of this paper is to stimulate new areas of study and innovative approaches.