Monocyte-chemo-attractant-protein-1 (MCP-1)-gene expression in cervical intra-epithelial neoplasias and cervical carcinomas

Role of chemokines in HPV-induced cancers

Human papillomaviruses (HPVs) cause cancers of the uterine cervix, oropharynx, anus, and vulvovaginal tract. Low-risk HPVs, such as HPV6 and 11, can also cause benign mucosal lesions including genital warts, and in patients with recurrent respiratory papillomatosis, lesions in the larynx, and on occasion, in the lungs. However, both high and less tumorigenic HPVs share a striking commonality in manipulating both innate and adaptive immune responses in HPV- infected keratinocytes, the natural host for HPV infection. In addition, immune/inflammatory cell infiltration into the tumor microenvironment influences cancer growth and prognosis, and this process is tightly regulated by different chemokines. Chemokines are small proteins and exert their biological effects by binding with G protein-coupled chemokine receptors (GPCRs) that are found on the surfaces of select target cells. Chemokines are not only involved in the establishment of a pro-tumorigenic microenvironment and organ-directed metastases but also involved in disease progression through enhancing tumor cell growth and proliferation. Therefore, having a solid grasp on chemokines and immune checkpoint modulators can help in the treatment of these cancers. In this review, we discuss the recent advances on the expression patterns and regulation of the main chemokines found in HPV-induced cancers, and their effects on both immune and non-immune cells in these lesions. Importantly, we also present the current knowledge of therapeutic interventions on the expression of specific chemokine and their receptors that have been shown to influence the development and progression of HPV-induced cancers.

Role of CC-chemokine ligand 2 in gynecological cancer

Gynecological cancer is one of the most severe diseases that threaten the lives and health of women worldwide. Its incidence rate increases with each passing year and becomes more prevalent among young people. The prognosis of gynecological cancer remains poor despite significant advances in surgical removal and systemic chemotherapy. Several chemokines play a role in the progression of gynecologic cancers. CCL2 (CC-chemokine ligand 2), also termed MCP-1 (monocyte chemotactic protein 1), plays a significant physiological role in monocyte cell migration and the inflammatory response. Recent studies have demonstrated that CCL2 plays a pro-tumorigenic function in the tumor microenvironment. According to previous studies, CCL2 plays a significant role in the occurrence and development of gynecological cancers. Furthermore, recent studies noted that CCL2 could be a potential diagnostic biomarker and prognostic predictor. The purpose of this paper is to review the role of CCL2 in the occurrence and development of gynecological cancers and to discuss the potential therapeutic strategy of CCL2 for gynecological cancers, with a primary focus on breast cancer, ovarian cancer, cervical cancer, and endometrial cancer.

The Role of Chemokines in Cervical Cancers

Both clinical-pathological and experimental studies have shown that chemokines play a key role in activating the immune checkpoint modulator in cervical cancer progression and are associated with prognosis in tumor cell proliferation, invasion, angiogenesis, chemoresistance, and immunosuppression. Therefore, a clear understanding of chemokines and immune checkpoint modulators is essential for the treatment of this disease. This review discusses the origins and categories of chemokines and the mechanisms that are responsible for activating immune checkpoints in cervical dysplasia and cancer, chemokines as biomarkers, and therapy development that targets immune checkpoints in cervical cancer research.

Cytokine expression profiles in cervical mucus from patients with cervical cancer and its precursor lesions

Human papillomavirus (HPV) infection can persist in the cervical epithelium without provoking a strong host immune response, leading to the development of cervical cancer. Cytokines, which mediate innate and adaptive immune activities, are secreted in the cervical mucus; however, there is currently no appropriate method for assessing cytokine levels in mucus specimens. Here, we employed multiplexed bead-based immunoassays to examine cytokine levels in cervical mucus using both weighted-volume and total protein concentration methods to adjust for different specimen volumes in individual patients. Out of 18 cytokines initially examined in the primary cohort patient group (n = 28), 14 were detected in more than 10% of the samples. Of these 14 cytokines, expression levels of interferon (IFN)-γ, granulocyte-macrophage colony-stimulating factor (GM-CSF), RANTES, and eotaxin were significantly increased with the disease severity in the secondary cohort patient group (n = 235). We also examined associations between cytokine levels and clinical parameters, such as cytology and HPV genotype. Of the 14 cytokines, granulocyte colony-stimulating factor (G-CSF) was downregulated in HPV-positive specimens. Examination of co-expression patterns of cytokines in relation to HPV infection status revealed that several pairs of cytokines were simultaneously upregulated in HPV-positive cases, including INF-γ and interleukin (IL)-17A, GM-CSF and monocyte chemoattractant protein-1 (MCP-1), GM-CSF and RANTES, IL-17A and RANTES, and MCP-1 and eotaxin. Interestingly, upregulation of GM-CSF and RANTES might reflect a shift in immuno-regulatory cytokines in HPV-positive specimens, potentially associated with more severe cervical neoplasia.

Suppressive Effects of EGCG on Cervical Cancer

Cervical cancer is the fourth most common gynecological cancer worldwide. Although prophylactic vaccination presents the most effective method for cervical cancer prevention, chemotherapy is still the primary invasive intervention. It is urgent to exploit low-toxic natural anticancer drugs on account of high cytotoxicity and side-effects of conventional agents. As a natural product, (-)-epigallocatechingallate (EGCG) has abilities in anti-proliferation, anti-metastasis and pro-apoptosis of cervical cancer cells. Moreover, EGCG also has pharmaceutical synergistic effects with conventional agents such as cisplatin (CDDP) and bleomycin (BLM). The underlying mechanisms of EGCG suppressive effects on cervical cancer are reviewed in this article. Further research directions and ambiguous results are also discussed.

Constitutive activation and overexpression of NF-κB/c-Rel in conjunction with p50 contribute to aggressive tongue tumorigenesis

Tongue squamous cell carcinoma (TSCC) is a most aggressive head and neck cancer often associated with a poor survival rate. Yet, it always shows better prognosis in presence of HPV16 infection. NF-κB plays a pivotal role in carcinogenesis and chemo-radio resistance of cancer but its role in tongue cancer is not yet explored. In this study, a total of hundred tongue tissue biopsies comprising precancer, cancer and adjacent normal controls including two tongue cancer cell lines (HPV^+/−ve) were employed to examine expression and transactivation of NF-κB proteins, their silencing by siRNA and invasion assays to understand their contributions in tongue carcinogenesis. An exclusive prevalence (28%) of HR-HPV type 16 was observed mainly in well differentiated tumors (78.5%). Increased DNA binding activity and differential expression of NF-κB proteins was observed with p50 and c-Rel being the two major DNA binding partners forming the functional NF-κB complex that increased as a function of severity of lesions in both HPV^+/−ve tumors but selective participation of p65 in HPV16^+ve TSCCs induced well differentiation of tumors resulting in better prognosis. siRNA treatment against c-Rel or Fra-2 led to upregulation of p27 but strong inhibition of c-Rel, c-Jun, c-myc, HPVE6/E7 and Fra-2 which is exclusively overexpressed in HPV^−ve aggressive tumors. In conclusion, selective participation of c-Rel with p50 that in cross-talk with AP-1/Fra-2 induced poor differentiation and aggressive tumorigenesis mainly in HPV^−ve smokers while HPV infection induced expression of p65 and p27 leading to well differentiation and better prognosis preferably in non-smoking TSCC patients.

Immunopathogenesis of HPV-Associated Cancers and Prospects for Immunotherapy

Human papillomavirus (HPV) infection is a causative factor for various cancers of the anogenital region and oropharynx, and is supposed to play an important cofactor role for skin carcinogenesis. Evasion from immunosurveillance favors viral persistence. However, there is evidence that the mere presence of oncogenic HPV is not sufficient for malignant progression and that additional tumor-promoting steps are required. Recent studies have demonstrated that HPV-transformed cells actively promote chronic stromal inflammation and conspire with cells in the local microenvironment to promote carcinogenesis. This review highlights the complex interplay between HPV-infected cells and the local immune microenvironment during oncogenic HPV infection, persistence, and malignant progression, and discusses new prospects for diagnosis and immunotherapy of HPV-associated cancers.

RIPK3 expression in cervical cancer cells is required for PolyIC-induced necroptosis, IL-1α release, and efficient paracrine dendritic cell activation

Previous studies have shown that cervical cancer cells only release low levels of pro-inflammatory cytokines owing to infection with human papillomaviruses. This results in low immunogenicity of the cancer cells. The viral dsRNA analog PolyIC has been suggested as a promising adjuvant for cervical cancer immunotherapy. However, little is known about the molecular requirements resulting in successful immune activation. Here, we demonstrate that stimulation of cervical cancer cells with PolyIC induced necroptotic cell death, which was strictly dependent on the expression of the receptor-interacting protein kinase RIPK3. Necroptotic cancer cells released interleukin-1α (IL-1α), which was required for powerful activation of dendritic cells (DC) to produce IL-12, a cytokine critical for anti-tumor responses. Again both, IL-1α release and DC activation, were strictly dependent on RIPK3 expression in the tumor cells. Of note, our in situ analyses revealed heterogeneous RIPK3 expression patterns in cervical squamous cell carcinomas and adenocarcinomas. In summary, our study identified a novel RIPK3-dependent mechanism that explains how PolyIC-treatment of cervical cancer cells leads to potent DC activation. Our findings suggest that the RIPK3 expression status in cervical cancer cells might critically influence the outcome of PolyIC-based immunotherapeutic approaches and should therefore be assessed prior to immunotherapy.

Stromal Fibroblasts Induce CCL20 through IL6/C/EBPβ to Support the Recruitment of Th17 Cells during Cervical Cancer Progression

Cervical cancer is a consequence of persistent infection with human papillomaviruses (HPV). Progression to malignancy is linked to an inflammatory microenvironment comprising T-helper-17 (Th17) cells, a T-cell subset with protumorigenic properties. Neoplastic cells express only low endogenous levels of the Th17 chemoattractant CCL20, and therefore, it is unclear how Th17 cells are recruited to the cervical cancer tissue. In this study, we demonstrate that CCL20 was predominantly expressed in the stroma of cervical squamous cell carcinomas in situ. This correlated with stromal infiltration of CD4(+)/IL17(+) cells and with advancing International Federation of Gynecology and Obstetrics (FIGO) stage. Furthermore, we show that cervical cancer cells instructed primary cervical fibroblasts to produce high levels of CCL20 and to attract CD4/IL17/CCR6-positive cells, generated in vitro, in a CCL20/CCR6-dependent manner. Further mechanistic investigations identified cervical cancer cell-derived IL6 as an important mediator of paracrine CCL20 induction at the promoter, mRNA, and protein level in fibroblasts. CCL20 was upregulated through the recently described CCAAT/enhancer-binding protein β (C/EBPβ) pathway as shown with a dominant-negative version of C/EBPβ and through siRNA-mediated knockdown. In summary, our study defines a novel molecular mechanism by which cervical neoplastic cells shape their local microenvironment by instructing fibroblasts to support Th17 cell infiltration in a paracrine IL6/C/EBPβ-dependent manner. Th17 cells may in turn maintain chronic inflammation within high-grade cervical lesions to further promote cancer progression.

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.

Cervical cancer cell-derived interleukin-6 impairs CCR7-dependent migration of MMP-9-expressing dendritic cells

Cervical carcinogenesis is a consequence of persistent infection with high-risk human papillomaviruses (HPVs). Recent studies indicate that HPV-transformed cells actively instruct their microenvironment to promote carcinogenesis. Here, we demonstrate that cervical cancer cells activate monocytes to produce their own CCL2 for further monocyte recruitment and reprogram their function during differentiation and maturation to dendritic cells (DCs). Our data show that cervical cancer cells suppress the induction of the chemokine receptor CCR7 in phenotypically mature DCs and impair their migration toward a lymph node homing chemokine, required to initiate adaptive immune responses. We confirmed the presence of CD83(+)CCR7(low) DCs in cancer biopsies. The second factor essential for DC migration, matrix-metalloproteinase MMP-9, which also has vasculogenic and protumorigenic properties, is not suppressed but upregulated in immature as well as mature DCs. We identified interleukin-6 (IL-6) as a crucial cervical cancer cell-derived mediator and nuclear factor kappaB (NF-jB) as the central signaling pathway targeted in DCs. Anti-IL-6 antibodies reverted not only NF-jB inhibition and restored CCR7-dependent migration but also blocked MMP-9 induction. This is the first report demonstrating the dissociation of CCR7 and MMP-9 expression in phenotypically mature CD83(+) DCs by cancer cells. Our results show that cervical cancer cells actively shape the local microenvironment. They induce the accumulation of myeloid cells and skew their function from immune activation to local production of protumorigenic MMP-9. Neutralizing anti-IL-6 antibodies can counteract this functional dysbalance and should therefore be considered for adjuvant cervical cancer therapy.

Post-translational control of IL-1β via the human papillomavirus type 16 E6 oncoprotein: a novel mechanism of innate immune escape mediated by the E3-ubiquitin ligase E6-AP and p53

Infections with high-risk human papillomaviruses (HPVs) are causally involved in the development of anogenital cancer. HPVs apparently evade the innate immune response of their host cells by dysregulating immunomodulatory factors such as cytokines and chemokines, thereby creating a microenvironment that favors malignancy. One central key player in the immune surveillance interactome is interleukin-1 beta (IL-1β) which not only mediates inflammation, but also links innate and adaptive immunity. Because of its pleiotropic physiological effects, IL-1β production is tightly controlled on transcriptional, post-translational and secretory levels. Here, we describe a novel mechanism how the high-risk HPV16 E6 oncoprotein abrogates IL-1β processing and secretion in a NALP3 inflammasome-independent manner. We analyzed IL-1β regulation in immortalized keratinocytes that harbor the HPV16 E6 and/or E7 oncogenes as well as HPV-positive cervical tumor cells. While in primary and in E7-immortalized human keratinocytes the secretion of IL-1β was highly inducible upon inflammasome activation, E6-positive cells did not respond. Western blot analyses revealed a strong reduction of basal intracellular levels of pro-IL-1β that was independent of dysregulation of the NALP3 inflammasome, autophagy or lysosomal activity. Instead, we demonstrate that pro-IL-1β is degraded in a proteasome-dependent manner in E6-positive cells which is mediated via the ubiquitin ligase E6-AP and p53. Conversely, in E6- and E6/E7-immortalized cells pro-IL-1β levels were restored by siRNA knock-down of E6-AP and simultaneous recovery of functional p53. In the context of HPV-induced carcinogenesis, these data suggest a novel post-translational mechanism of pro-IL-1β regulation which ultimately inhibits the secretion of IL-1β in virus-infected keratinocytes. The clinical relevance of our results was further confirmed in HPV-positive tissue samples, where a gradual decrease of IL-1β towards cervical cancer could be discerned. Hence, attenuation of IL-1β by the HPV16 E6 oncoprotein in immortalized cells is apparently a crucial step in viral immune evasion and initiation of malignancy.

Persistently high-risk HPV-infected individuals have an increased risk to develop anogenital cancer. HPV encodes the viral proteins E6 and E7 that interact with and induce the degradation of the cell cycle regulators p53 and pRb, respectively, priming immortalized keratinocytes towards malignant transformation. In early antiviral immune response, IL-1β is an important factor for the initiation of inflammation and activation of immune cells such as macrophages and T cells. Our study describes a post-translationally controlled pathway where E6 mediates proteasomal degradation of IL-1β in HPV16-immortalized human keratinocytes. This process depends on the cellular ubiquitin ligase E6-AP and p53 highlighting a novel molecular mechanism of a virus-host interaction that is critical for evading innate immune defense. IL-1β dysregulation is also found in tissue sections which represent different stages of virus-induced carcinogenesis, underlining the clinical relevance of our findings.

Relationships of single nucleotide polymorphisms of monocyte chemoattractant protein 1 and chemokine receptor 2 with susceptibility and clinicopathologic characteristics of neoplasia of uterine cervix in Taiwan women

Few studies reported the implication of single nucleotide polymorphisms (SNPs) of monocyte chemoattractant protein 1 (MCP-1) and its receptor chemokine receptor 2 (CCR-2) in clinical significance of cancer of uterine cervix. We hypothesized that SNPs of MCP-1 and CCR-2 may affect the expression of these genes and then proteins. Therefore, we investigated the influence of the gene polymorphisms of MCP-1 and CCR-2 on the susceptibility and clinicopathologic characteristics of cervical neoplasia in Taiwan women. We recruited 86 patients with invasive cancer and 61 with high-grade dysplasia and 253 control women and selected 1 MCP-1 SNP rs1024611 (-2518G/A) and 1 CCR-2 SNP rs1799864 (190G/A; V64I) to determine their genotypes distribution using polymerase chain reaction-restriction fragment length polymorphism. In comparison to normal individuals with homozygotes GG in MCP-2 SNP, women with GA or AA carried a 2.01 odds ratio of developing cervical cancer. Nevertheless, it was not demonstrated in CCR-2 SNP. Furthermore, women with mutant homozygote (AA) of MCP-1 SNP increased the risk of deep stromal invasion, large tumor diameter, and parametrium invasion of cervical cancer, when compared to those with wild homozygote GG or heterozygote GA. However, women with mutant homozygotes (AA) of CCR-2 SNP did not increase the risk of poor clinicopathologic characteristics. In conclusion, MCP-1 SNP may be correlated with the development, deep stromal invasion, large tumor diameter, and parametrium invasion of cervical cancer but not with cancer recurrence or survival of Taiwan women patients with cancer. However, the SNP of its receptor, CCR-2, is not implicated in cervical cancer.

Immunotherapy of human papilloma virus induced disease

Immunotherapy is the generic name for treatment modalities aiming to reinforce the immune system against diseases in which the immune system plays a role. The design of an optimal immunotherapeutic treatment against chronic viruses and associated diseases requires a detailed understanding of the interactions between the target virus and its host, in order to define the specific strategies that may have the best chance to deliver success at each stage of disease. Recently, a first series of successes was reported for the immunotherapy of Human Papilloma Virus (HPV)-induced premalignant diseases but there is definitely room for improvement. Here I discuss a number of topics that in my opinion require more study as the answers to these questions allows us to better understand the underlying mechanisms of disease and as such to tailor treatment.

A comprehensive review on host genetic susceptibility to human papillomavirus infection and progression to cervical cancer

Cervical cancer is the second most common cancer in women worldwide. This is caused by oncogenic types of human papillomavirus (HPV) infection. Although large numbers of young sexually active women get HPV-infected, only a small fraction develop cervical cancer. This points to different co-factors for regression of HPV infection or progression to cervical cancer. Host genetic factors play an important role in the outcome of such complex or multifactor diseases such as cervical cancer and are also known to regulate the rate of disease progression. The aim of this review is to compile the advances in the field of host genetics of cervical cancer. MEDLINE database was searched using the terms, ‘HPV’, ‘cervical’, ‘CIN’, ‘polymorphism(s)’, ‘cervical’+ *the name of the gene* and ‘HPV’+ *the name of the gene*. This review focuses on the major host genes reported to affect the progression to cervical cancer in HPV infected individuals.

Early transcriptional pattern of angiogenesis induced by EGCG treatment in cervical tumour cells

The major green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) has been shown to exhibit antitumour activities in several tumour models. One of the possible mechanisms by which EGCG can inhibit cancer progression is through the modulation of angiogenesis signalling cascade. The tumour cells’ ability to tightly adhere to endothelium is a very important process in the metastatic process, because once disseminated into the bloodstream the tumour cells must re-establish adhesive connections to endothelium in order to extravasate into the target tissues. In this study, we investigated the anti-angiogenic effects of EGCG treatment (10 μM) on human cervical tumour cells (HeLa) by evaluating the changes in the expression pattern of 84 genes known to be involved in the angiogenesis process. Transcriptional analysis revealed 11 genes to be differentially expressed and was further validated by measuring the induced biological effects. Our results show that EGCG treatment not only leads to the down-regulation of genes involved in the stimulation of proliferation, adhesion and motility as well as invasion processes, but also to the up-regulation of several genes known to have antagonist effects. We observed reduced proliferation rates, adhesion and spreading ability as well as invasiveness of HeLa tumour cells upon treatment, which suggest that EGCG might be an important anti-angiogenic therapeutic approach in cervical cancers.

Molecular pathobiology of human cervical high-grade lesions: paracrine STAT3 activation in tumor-instructed myeloid cells drives local MMP-9 expression

In many tumors, the switch from precancerous lesions to malignancy critically relies on expression of the matrix-metalloprotease MMP-9, which is predominantly provided by infiltrating inflammatory cells. Our study defines a novel molecular cascade, how human neoplastic cells instruct tumor-associated myeloid cells to produce MMP-9. In biopsies of human papillomavirus-associated precancerous cervical intraepithelial neoplasia (CIN III lesions), we show broad activation of the transcription factor STAT3 and coexpression of MMP-9 in perivascular inflammatory cells. For the first time, we establish a causative link between tumor-mediated paracrine STAT3 activation and MMP-9 production by human tumor-instructed monocytes, whereas NF-κB activation is dispensable for this response. Our data provide evidence that STAT3 does not directly induce MMP-9 but first leads to a strong production of the monocyte chemoattractant protein-1 (CCL2) in the nanogram range. In a second phase, autocrine stimulation of the CCR2 receptor in the tumor-instructed monocytes amplifies MMP-9 expression via intracellular Ca(2+) signaling. These findings elucidate a critical mechanism in the molecular pathobiology of cervical carcinogenesis at the switch to malignancy. Particularly in tumors, which are associated with infectious agents, STAT3-driven inflammation may be pivotal to promote carcinogenesis, while at the same time limit NF-κB-dependent immune responses and thus rejection of the infected preneoplastic cells. The molecular cascade defined in this study provides the basis for a rational design of future adjuvant therapies of cervical precancerous lesions.

FSP1+ fibroblasts promote skin carcinogenesis by maintaining MCP-1-mediated macrophage infiltration and chronic inflammation

Cancer development is often associated with increased fibroblast proliferation and extensive fibrosis; however, the role of fibroblasts during carcinogenesis remains largely unknown. Using the 7,12-dimethylbenz-(a)anthracene and 12-O-tetradecanoylphorbol-13-acetate-induced two-stage skin carcinogenesis model, we demonstrated here that there was a massive accumulation and proliferation of fibroblasts in the skin shortly after application of carcinogen. Selective abatement of these cells during the promotion stage drastically decreased incidence and progression of papillomas. This correlated well with reduced macrophage infiltration and impaired cytokine storm in the affected skin. 12-O-tetradecanoylphorbol-13-acetate stimulated skin fibroblasts, secreting high levels of monocyte chemotactic protein-1, and neutralization of this chemokine eliminated almost completely the fibroblast-induced chemotaxis of macrophages. These results strongly suggest that fibroblasts promote skin tumor development by producing monocyte chemotactic protein-1 and maintaining chronic inflammation.

CCR2-V64I polymorphism is associated with increased risk of cervical cancer but not with HPV infection or pre-cancerous lesions in African women

BACKGROUND

Cervical cancer, caused by specific oncogenic types of human papillomavirus (HPV), is the second most common cancer in women worldwide. A large number of young sexually active women get infected by HPV but only a small fraction of them have persistent infection and develop cervical cancer pointing to co- factors including host genetics that might play a role in outcome of the HPV infection. This study investigated the role of CCR2-V64I polymorphism in cervical cancer, pre-cancers and HPV infection in South African women resident in Western Cape. CCR2-V64I polymorphism has been previously reported to influence the progression to cervical cancer in some populations and has also been associated with decreased progression from HIV infection to AIDS.

METHODS

Genotyping for CCR2-V64I was done by PCR-SSP in a case-control study of 446 women (106 black African and 340 mixed-ancestry) with histologically confirmed invasive cervical cancer and 1432 controls (322 black African and 1110 mixed-ancestry) group-matched (1:3) by age, ethnicity and domicile status. In the control women HPV was detected using the Digene Hybrid Capture II test and cervical disease was detected by cervical cytology.

RESULTS

The CCR2-64I variant was significantly associated with cervical cancer when cases were compared to the control group (P = 0.001). Further analysis comparing selected groups within the controls showed that individuals with abnormal cytology and high grade squamous intraepitleial neoplasia (HSIL) did not have this association when compared to women with normal cytology. HPV infection also showed no association with CCR2-64I variant. Comparing SIL positive controls with the cases showed a significant association of CCR2-64I variant (P = 0.001) with cervical cancer.

CONCLUSIONS

This is the first study of the role of CCR2-V64I polymorphism in cervical cancer in an African population. Our results show that CCR2-64I variant is associated with the risk of cervical cancer but does not affect the susceptibility to HPV infection or HSIL in South African women of black and mixed-ancestry origin. This result implies that the role of CCR2 is important in invasive cancer of the cervix but not in HPV infection or in the development of pre-cancers.

Regulation of MCP-1 chemokine transcription by p53

BACKGROUND

Our previous studies showed that the expression of the monocyte-chemoattractant protein (MCP)-1, a chemokine, which triggers the infiltration and activation of cells of the monocyte-macrophage lineage, is abrogated in human papillomavirus (HPV)-positive premalignant and malignant cells. In silico analysis of the MCP-1 upstream region proposed a putative p53 binding side about 2.5 kb upstream of the transcriptional start. The aim of this study is to monitor a physiological role of p53 in this process.

RESULTS

The proposed p53 binding side could be confirmed in vitro by electrophoretic-mobility-shift assays and in vivo by chromatin immunoprecipitation. Moreover, the availability of p53 is apparently important for chemokine regulation, since TNF-alpha can induce MCP-1 only in human keratinocytes expressing the viral oncoprotein E7, but not in HPV16 E6 positive cells, where p53 becomes degraded. A general physiological role of p53 in MCP-1 regulation was further substantiated in HPV-negative cells harboring a temperature-sensitive mutant of p53 and in Li-Fraumeni cells, carrying a germ-line mutation of p53. In both cases, non-functional p53 leads to diminished MCP-1 transcription upon TNF-alpha treatment. In addition, siRNA directed against p53 decreased MCP-1 transcription after TNF-alpha addition, directly confirming a crosstalk between p53 and MCP-1.

CONCLUSION

These data support the concept that p53 inactivation during carcinogenesis also affects immune surveillance by interfering with chemokine expression and in turn communication with cells of the immunological compartment.

Mononuclear phagocytes in head and neck squamous cell carcinoma

The head and neck squamous cell carcinoma microenvironments contain many immune cells and their secretory products. Many of these cells belong to the mononuclear phagocyte system. The aim of this review is to study the interactions between mononuclear phagocytes and head and neck squamous cell carcinoma tissue. The role of inflammation in tumours and the cytokine interleukin-6 will be highlighted. Future therapy strategies in the treatment of head and neck cancer might be directed towards mononuclear phagocytes and their cytokine production.

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

BACKGROUND

Vascular endothelial growth factor (VEGF) plays an important role in cervical intraepithelial neoplasia (CIN) progression. The occurrence of leukocytes has been documented in CIN; however, their role in VEGF production remains unknown. Oxidative stress has been involved in the progression of malignant neoplasias, but to the authors' knowledge tissue oxidative stress in CIN has not been documented. The objective of the current study was to investigate the expression of VEGF, leukocyte infiltration, leukocyte VEGF expression, and nitrogen/oxygen metabolism in cervical tissues from patients with CIN.

METHODS

Indirect immunofluorescence was used to study the expression of VEGF and leukocyte infiltration in cervical samples from 55 patients with CIN and 7 normal controls. Superoxide anion (O(2) (-)) expression was determined by a cytochemical method, and tissue and serum nitric oxide by the Griess reaction. Human papillomavirus (HPV) DNA and HPV types were identified by the hybrid capture 2 HPV DNA test.

RESULTS

Increased expression of VEGF was observed related to the progression of CIN. A significant increment of CD3 lymphocytes was found in CIN type 3 (CIN 3) and coexpression of CD3/VEGF and monocyte-macrophage/VEGF in CIN 2 and 3. Increased O(2) (-)-positive cells were found in CIN 2 and 3; however, tissue nitrate-nitrite content remained similar to controls. The incidence of HPV infection was 16% in patients with CIN. No significant differences were observed in the values of HPV-positive or HPV-negative patients.

CONCLUSIONS

Different factors leading to cervical neoplasia progression may be involved in the evolution of CIN, and the presence of these factors is most likely not related to the HPV infection status.

Decreased expression of monocyte chemoattractant protein-1 predicts poor prognosis following curative resection of colorectal cancer

PURPOSE

The significance of monocyte chemoattractant protein-1 in colorectal cancer is not well understood. The aim of this study was to investigate the significance of monocyte chemoattractant protein-1 expression in colorectal cancer patients undergoing potentially curative surgery.

METHODS

We studied 101 colorectal cancer patients who underwent potentially curative surgery. The concentration of monocyte chemoattractant protein-1 in the tumor and normal mucosa were measured. The expression of monocyte chemoattractant protein-1 was also evaluated immunohistochemically.

RESULTS

The tissue concentration of monocyte chemoattractant protein-1 in the tumor was significantly higher than that in the normal mucosa. The decreased monocyte chemoattractant protein-1 cancer/normal ratio was associated with lymph node involvement and could predict poor prognosis. On univariate analysis, the decreased monocyte chemoattractant protein-1 ratio, carcinoembryonic antigen levels, and serosal invasion were the significant factors for poor prognosis. Multivariate analysis showed that monocyte chemoattractant protein-1 ratio was the only independent risk factor predictive of a poor prognosis. Immunohistochemically, monocyte chemoattractant protein-1 was expressed in the cytoplasm.

CONCLUSION

The decreased monocyte chemoattractant protein-1 ratio was an independent factor predicting poor prognosis in patients undergoing potentially curative surgery. Monocyte chemoattractant protein-1 deficiency may present a new therapeutic approach for colorectal cancer.

Plasticity in tumor-promoting inflammation: impairment of macrophage recruitment evokes a compensatory neutrophil response

Previous studies in the K14-HPV/E(2) mouse model of cervical carcinogenesis demonstrated that infiltrating macrophages are the major source of matrix metalloproteinase 9 (MMP-9), a metalloprotease important for tumor angiogenesis and progression. We observed increased expression of the macrophage chemoattractant, CCL2, and its receptor, CCR2, concomitant with macrophage influx and MMP-9 expression. To study the role of CCL2-CCR2 signaling in cervical tumorigenesis, we generated CCR2-deficient K14-HPV/E(2) mice. Cervixes of CCR2-null mice contained significantly fewer macrophages. Surprisingly, there was only a modest delay in time to progression from dysplasia to carcinoma in the CCR2-deficient mice, and no difference in end-stage tumor incidence or burden. Moreover, there was an unexpected persistence of MMP-9 activity, associated with increased abundance of MMP-9(+) neutrophils in tumors from CCR2-null mice. In vitro bioassays revealed that macrophages produce soluble factor(s) that can suppress neutrophil dynamics, as evidenced by reduced chemotaxis in response to CXCL8, and impaired invasion into three-dimensional tumor masses grown in vitro. Our data suggest a mechanism whereby CCL2 attracts proangiogenic CCR2(+) macrophages with the ancillary capability to limit infiltration by neutrophils. If such tumor-promoting macrophages are suppressed, MMP-9(+) neutrophils are then recruited, providing alternative paracrine support for tumor angiogenesis and progression.

Protein array-based multiplexed cytokine assays

We have demonstrated a microarray format immunoassay using HydroGel-coated slides. HydroGel is a porous substrate based on a polymer matrix that provides a three-dimensional hydrophilic environment similar to free solution suitable for biomolecular interactions. This substrate has been used to develop fluorescence-based multiplexed cytokine immunoassays. Forty-three monoclonal antibodies (mAbs) of cytokines and chemokines are printed at a volume of 350 pL per spot using a PerkinElmer BioChip Arrayer. Cytokines that are captured by the arrayed mAb are detected using another biotinylated mAb, following by the addition of a Texas red conjugated streptavidin. The fluorescent images of arrays are recorded using a PerkinElmer ScanArray 5000 confocal slide scanner and quantitated using PerkinElmer QuantArray software. Experiments demonstrate that 43 cytokines can be simultaneously screened and quantitated in conditioned culture media, cell lysate, and human plasma. Using this chip, we have examined cytokine expression in breast cancer cells and identified the chemokines associated with human cervical cancers.

Tumour-associated macrophages secrete IL-6 and MCP-1 in head and neck squamous cell carcinoma tissue

Conclusion. Tumour-associated macrophages (TAMs) in head and neck squamous cell carcinomas (HNSCCs) secrete interleukin 6 (IL-6) and monocyte chemotactic protein (MCP-1) that can be down-regulated by L-leucine-methylester (LLME); however, there is no qualitative difference between function of TAMs and tissue macrophages in mucosa as measured by IL-6 and MCP-1 secretion. Objectives. TAMs play an important role in the interaction with tumour cells in malignant tumours. The cells in the tumours that are the main sources of the various signal substances need to be further elucidated. The aim of this investigation was to reveal whether TAMs in HNSCCs secrete IL-6 and MCP-1. These cytokines influence tumour cell growth and macrophage influx in tumours, respectively. Materials and methods. In order to inhibit macrophage function in F-spheroids, in some experiments the tissue fragments were initially incubated with LLME, a substance that selectively inhibits function of phagocytes. IL-6 and MCP-1 secretion from untreated F-spheroids was compared to cytokine secretion from LLME-treated F-spheroids as measured by ELISA. Results. LLME did not affect the viability of F-spheroids and reduced IL-6 and MCP-1 secretion from monocyte-derived macrophages in vitro. F-spheroids from LLME-treated tissue fragments showed lower IL-6 and MCP-1 secretion compared with F-spheroids from tissue fragment untreated with LLME.

Variants of chemokine receptor 2 and interleukin 4 receptor, but not interleukin 10 or Fas ligand, increase risk of cervical cancer

Cervical cancer is caused by persistent infection of oncogenic human papillomavirus (HPV). Most infected women clear the virus without developing cervical lesions and it is likely that immunological host factors affect susceptibility to cervical cancer. The impact of the human leukocyte antigen (HLA) locus on the risk of cervical cancer is established and several other genes involved in immunological pathways have been suggested as biologically plausible candidates. The aim of this study was to examine the potential role of polymorphisms in 4 candidate genes by analysis of 1,306 familial cervical cancer cases and 288 controls. The following genes and polymorphisms were studied: Chemokine receptor 2 (CCR-2) V64I; Interleukin 4 receptor alpha (IL-4R) I75V, S503P and Q576R; Interleukin 10 (IL-10) -592; and Fas ligand (FasL) -844. The CCR-2 64I variant was associated with decreased risk of cervical cancer; homozygote carriers of the 64I variant had an odds ratio of 0.31 (0.12-0.77). This association was detected in both carriers and noncarriers of the HLA DQB1*0602 cervical cancer risk allele. The IL-4R 75V variant was associated with increased risk of cervical tumors, cases homozygote for 75V had an odds ratio of 1.91 (1.27-2.86) with a tendency that the association was stronger in noncarriers of the DQB1*0602 allele. We did not find any association for IL-10 -592, or FasL -844, previously reported to be associated with cervical cancer in the Dutch and Chinese populations, respectively.

The absence of CCL2 expression in cervical carcinoma is associated with increased survival and loss of heterozygosity at 17q11.2

To determine whether CCL2 mRNA expression is beneficial or detrimental for cervical cancer patients, the association between the expression of this molecule by cervical tumour cells, the number of tumour-associated macrophages, and clinicopathological parameters such as recurrence, relapse-free survival, and overall patient survival was investigated. In cervical cancer samples from 93 untreated cervical cancer patients, the CCL2 mRNA expression level was quantified using RNA in situ hybridization and verified using real-time quantitative RT-PCR. The number of tumour-associated macrophages was determined using immunohistochemistry. Furthermore, the study investigated whether lack of CCL2 expression was due to genetic alterations near the 17q11.2 (CCL2 genomic) region. CCL2 mRNA expression by cervical tumour cells was associated with the number of tumour-associated macrophages (p < 0.001). Lack of CCL2 mRNA expression (15 samples; 16%) was associated with increased cumulative relapse-free survival (log rank test, p = 0.030), increased cumulative overall survival (log rank test, p = 0.024), less post-operative surgery, reduced local and distant recurrence, reduced vascular invasion, and smaller tumour size (<40 mm). The absence of CCL2 mRNA expression corresponded with loss of heterozygosity (LOH) at 17q11.2 in five of six samples. The increased cumulative relapse-free survival and cumulative overall survival of cervical cancer patients lacking tumour cell-associated CCL2 mRNA suggest that the tumour-associated macrophages support tumour progression, presumably by promoting angiogenesis and production of growth factors.

Reduced expression of chemokine (C-C motif) ligand-2 (CCL2) in ovarian adenocarcinoma

Chemokine (C-C motif) ligand-2 (CCL2) is a chemoattractant and activator of macrophages and is a key determinant of the macrophage infiltrate into tumours. We demonstrate here that CCL2 is expressed in normal human ovarian surface epithelium (HOSE) cells and is silenced in most ovarian cancer cell lines, and silenced or downregulated in the majority of primary ovarian adenocarcinomas. Analysis of the CCL2 locus at 17q11.2–q12 showed loss of heterozygosity (LOH) in 70% of primary tumours, and this was significantly more common in tumours of advanced stage or grade. However, we did not detect any mutations in the CCL2 coding sequence in 94 primary ovarian adenocarcinomas. These data support the hypothesis that CCL2 may play a role in the pathobiology of ovarian cancers, but additional studies will be required to evaluate this possibility.

Protective role of the polymorphism CCR2-64I in the progression from squamous intraepithelial lesions to invasive cervical carcinoma

OBJECTIVE

Invasive cervical cancer (ICC) is one of the most common malignant diseases among women, representing almost 10% of all the cancers in the female population. The aim of this study was to explore the association of the CCR2-64I polymorphism with the risk of developing invasive cervical cancer (ICC) from squamous intraepithelial lesions (SILs).

METHODS

DNA samples were extracted from peripheral blood cells of 109 patients with squamous intraepithelial lesions (28 low-grade and 81 high-grade cases) and 217 patients with ICC. The CCR2-64I polymorphism was analyzed through polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) (BseJI). The odds ratio (OR) and its 95% confidence interval (CI) were calculated as a measure of the association between CCR2-64I genotypes and cervical cancer risk.

RESULTS

The frequency of the G/A genotype was significantly higher in SIL patients (n = 109) than ICC patients (n = 217) (P = 0.005; OR = 0.42; 95% CI: 0.22-0.83). Furthermore, no association was found when we analyzed the influence of the A allele in the progression from low-grade SIL (LSIL) to high-grade SIL (HSIL) (OR = 1.05; 95% CI = 0.370-2.98; P = 0.930), but a statistically significant association was found in the progression from high-grade SIL to ICC (OR = 0.435; 95% CI = 0.222-0.854; P = 0.014).

CONCLUSION

These findings suggest that CCR2-64I polymorphism might have a protective role in the evolution from high-grade SIL to ICC.

Distribution of Immune Cell Subsets and Cytokine-Producing Cells in the Uterine Cervix of Human Papillomavirus (HPV)-Infected Women

The aim of this study was to characterize the immune system profile in the uterine cervix of 17 human papillomavirus (HPV)-infected women, compared with 17 whom were coinfected with HIV-1. Five histologically normal cervices in immunocompetent women were used as controls. HPV infection was associated with a marked increase in cells expressing interleukin (IL)-6, interferon gamma (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha). Coinfection by HPV and HIV-1 led to decreased expression of IL-6, TNF-alpha, and IFN-gamma. However, coinfection led to increased numbers of cells expressing IL-4, IL-10, and IL-8. Compared with the histologically normal cervices, increased numbers of macrophages (CD68, RFD7) and T lymphocytes (CD4, CD8) were seen in HPV-infected cervices; coinfection with HIV-1 was associated with a higher number of CD8 cells and lower number of CD68 cells. HPV DNA localized exclusively to the dysplastic squamous cells, whereas HIV-1 RNA was detected mainly in CD68-positive stromal cells. In conclusion, this study shows differential expression of various cytokines and classes of inflammatory cells, relative to HIV-1 infection and HPV coinfection, which may relate to the risk of transmission of HIV-1 and increased risk of cervical cancer in these women.

The fibroblast: sentinel cell and local immune modulator in tumor tissue

Development and progression of epithelial malignancies are frequently accompanied by complex phenotypic alterations of resident tissue fibroblasts. Some of these changes, such as myofibroblastic differentiation and an oncofetal extracellular matrix (ECM) expression profile, are also implicated in inflammation and tissue repair. Studies over the past decade revealed the relevance of reciprocal interactions between tumor cells and tumor-associated host fibroblasts (TAF) in the malignant process. In many tumors, a considerable fraction of the inflammatory infiltrate is located within the fibroblast- and ECM-rich stromal compartment. However, while fibroblasts are known as "sentinel cells" in various nonneoplastic diseases, where they often regulate the composition and function of recruited leucocytes, they are hardly considered active participants in the inflammatory host response in tumors. This article focuses on the functional impact of TAF on immune cells. The complex network of immune-modulating effects transduced by TAF and TAF-derived factors is highlighted, and recent reports that support the hypothesis that TAF are involved in the inflammatory response and immune suppression in tumors are reviewed. The role of TAF-dependent ECM remodeling and TAF-derived peptide growth factors, cytokines, and chemokines in the immune modulation is stressed and the idea of TAF as an important therapeutic target is emphasized.

Selective suppression of monocyte chemoattractant protein-1 expression by human papillomavirus E6 and E7 oncoproteins in human cervical epithelial and epidermal cells

Infection of cervical keratinocytes by high-risk HPV is involved in the etiology of cervical carcinoma. Since viral products are immunogenic, development of cancer may require suppression of immune responses directed against infected epithelial cells. Many markers of host immune effector responses decrease as cervical intraepithelial neoplasia progresses. Among these is epithelial cell expression of the chemokine MCP-1, though the mechanism for its suppression is unclear. Here, we show that the E6 and E7 viral oncogenes from high-risk HPV, individually and together, suppress MCP-1 expression in primary epithelial cells derived from the female genital tract. This is not a consequence of global suppression of chemokine expression since other chemokines, including IP-10, IL-8 and RANTES, were less affected. Furthermore, 4 of 6 HPV-positive cervical carcinoma cell lines did not express MCP-1. Our data indicate that suppression of MCP-1 expression is part of the program of high-risk HPV E6/E7-induced transformation of primary epithelial cells. These observations are consistent with a model in which MCP-1 expression by infected keratinocytes, which would stimulate an immune attack on HPV-transformed cells, is suppressed for invasive cervical cancer to appear.

Array-based multiplexed screening and quantitation of human cytokines and chemokines

HydroGel-coated slide is a porous substrate based on a polymer matrix that provides a three-dimensional hydrophilic environment similar to free solution suitable for biomolecular interactions. This substrate has been used to develop fluorescence-based multiplexed cytokine immunoassays. Forty-three monoclonal antibodies (mAb) of cytokines and chemokines were printed at a volume of 350 pL per spot using a Packard BioChip Arrayer. For each probe, four replicates were printed at a pitch of 500 microm in the layout of a 13 x 16 pattern on a 12 x 12 mm2 HydroGel pad. Cytokines and chemokines that are captured by the arrayed mAbs are detected by using another biotinylated mAb, following by the addition of a Texas Red-conjugated streptavidin. The fluorescent images of arrays were recorded using a Packard ScanArray 5000 confocal slide scanner and quantitated using Packard QuantArray software. Experiments demonstrated that 43 cytokines and chemokines could be simultaneously screened and quantitated in conditioned culture media, cell lysates, and human plasma. Using this chip, we have examined cytokine expression in breast cancer cells and identified the chemokines associated with human cervical cancers.

Abrogation of IRF-1 response by high-risk HPV E7 protein in vivo

We have previously reported that human papillomavirus (HPV) E7 interacts with IRF-1, a key regulator of cellular immune response, and abrogates its transactivation function at the molecular level in vitro. To confirm our previous data, we investigated in vivo the E7-mediated down-regulation of IRF-1 using HPV E7-inducible cells and transgenic mice expressing HPV-18 E6/E7. When E7 was induced in the absence of tetracycline, the expression of target genes of IRF-1 (TAP-1, IFN-beta, MCP-1 that are important for cellular immunity) was clearly reduced as determined by RT-PCR. In addition, the IRF-1 activity was down-regulated in E7-expressing cells into which IFN-beta-CAT reporter plasmid was transfected. To further investigate the E7-mediated immune regulation in vivo, we constructed transgenic mice expressing E6 and E7 genes of HPV-18 under the control of HPV-18 promoter (URR). From several rounds of breeding, we obtained from a transgenic line that developed a cervical dysplasia and expressed E6/E7 as determined by histological examination and RT-PCR, respectively. Subsequent RT-PCR analysis indicated that TAP-1, IFN-beta, and MCP-1 genes were less expressed in a cervical tissue derived from transgenic mouse, when compared with a cervix derived from normal mouse. From these results, we conclude that the E7 transgene expression inactivates the transactivation function of IRF-1 in vivo, which might be important for the elucidation of the E7-mediated immune evading mechanism that is frequently found in cervical cancer.

Chemokines in cancer

Chemokines participate, by regulating cell trafficking and controlling angiogenesis, in the host response during infection and inflammation. Most of these mechanisms are also operating in cancer. The stimulation of angiogenesis and tumor growth--directly or indirectly through the recruitment of tumor-associated macrophages--are typical situations where chemokines promote tumor development. On the other hand, chemokines could be used to the benefit of cancer patients as they act in the recruitment of dendritic cells (DC) or/and effector cells or for their angiostatic properties. However, chemokine-mediated recruitment of immature DC within tumors, due to factors produced by the tumor milieu, could lead to the induction of immune tolerance and, therefore, novel strategies to eradicate tumors based on chemokines should attempt to avoid this risk.

Disturbance of tumor necrosis factor alpha-mediated beta interferon signaling in cervical carcinoma cells

In the present study we show that malignant human papillomavirus (HPV)-positive cells lost their ability to synthesize endogenous beta interferon (IFN-beta) upon tumor necrosis factor alpha (TNF-alpha) treatment. IFN-beta transcription, however, was reinducible in nonmalignant HPV-positive cells, which was confirmed in functional protection assays against encephalomyocarditis virus or vesicular stomatitis virus infections. Addition of neutralizing antibodies against IFN-beta blocked the antiviral effect, excluding the possibility that other IFN types were involved. Conversely, both malignant and immortalized cells could be protected against viral cytolysis when either IFN-beta, IFN-alpha, or IFN-gamma was added exogenously. This indicates that only the cross talk between TNF-alpha and the IFN-beta pathways, and not IFN-alpha/beta and IFN-gamma signaling in general, is perturbed in cervical carcinoma cells. Notably, full virus protection was restricted exclusively to nonmalignant cells, indicating that the antiviral effect correlates with the growth-inhibitory and virus-suppressive properties of TNF-alpha. The IFN-regulatory factors IRF-1 and p48 (ISGF3gamma) emerged as key regulatory molecules in the differential IFN-beta response, since their transcription was either absent or only inefficiently enhanced in tumorigenic cells upon treatment with TNF-alpha. Inducibility of both genes, however, became reestablished in cervical carcinoma cells, which were complemented to nontumorigenicity after somatic cell hybridization. Complementation was paralleled by the entire reconstitution of cytokine-mediated IFN-beta expression and the ability of TNF-alpha to exert an antiviral state. In contrast, under conditions where tumor suppression was not accomplished upon somatic cell hybridization, neither expression of IRF-1, p48, and IFN-beta nor antiviral activity could be restored.

Cytokine profile of cervical cancer cells

OBJECTIVE

In patients with cervical carcinoma, the presence of cytokines produced by T(H)2 cells, and the presence of an eosinophilic inflammatory infiltrate, has been associated with a less effective immune response and tumor progression. In the present study, we have investigated the cytokine profile of cervical carcinoma cells. In addition, we have measured whether differences in cytokine profiles between normal and malignant cervical epithelial cells are present.

METHODS

For this purpose we have determined the mRNA expression patterns of 20 relevant cytokines by RT-PCR and Southern blotting in 3 normal primary cervical epithelial cell cultures (NPE) and 10 cervical cancer cell lines (CCCL).

RESULTS

TGF-beta(1), IL-4, IL-12p35, and IL-15 were produced by all CCCL and NPE. TNF-alpha, IL-10, IL-5, and RANTES were present in most NPE, but not in any of the CCCL. MCP-1 was expressed in all CCCL but in only one NPE. The presence of the anti-inflammatory cytokine TGF-beta(1) in cervical carcinomas was confirmed by RNA in situ hybridization on tissue sections of carcinomas from which the CCCL originated.

CONCLUSIONS

Our results suggest that cervical carcinoma cells produce immunomodulatory cytokines and that cytokine expression patterns change after malignant transformation. The implications of locally produced cytokines by cervical cancer cells are further discussed.

Differential sensitivity of human papillomavirus type 16(+) and type 18(+) cervical carcinoma cells to CD95-mediated apoptosis

When cervical carcinoma cells were monitored for apoptotic signals, HPV18(+) lines were found to be highly sensitive to agonistic CD95 antibodies or recombinant CD95 ligands after co-exposure with CHX (CD95(S)). In contrast, HPV16(+) cervical carcinoma cells and HPV16-immortalized non-malignant human keratinocytes were CD95-resistant (CD95(R)) under equivalent conditions. Somatic cell hybridization between CD95(S) and CD95(R) cervical carcinoma cell lines revealed that CD95 sensitivity was a dominant trait, which could be correlated with abundant c-Myc and low Bcl-X(L) expression. Although CD95(R) cervical carcinoma cells expressed even higher levels of p53 and CD95 receptor at the surface, resistance could be attributed to the inability to form a functional DISC, necessary for successful transmission of the apoptogenic response. These data indicate that resistance to apoptotic stimuli represents an important immunological escape mechanism during virus-induced carcinogenesis.

Significant correlation of monocyte chemoattractant protein-1 expression with neovascularization and progression of breast carcinoma

BACKGROUND

Macrophages often infiltrate into solid tumor tissues. Tumor-associated macrophages (TAMs) are known to play a crucial role in tumor progression. Monocyte chemoattractant protein-1 (MCP-1) is one of the major chemokines capable of inducing chemotactic migration of monocytes.

METHODS

With the objective of investigating the clinical significance of MCP-1, the authors analyzed the expression of MCP-1 and of some other molecules by immunohistochemistry in 230 samples of primary breast carcinoma tissue. MCP-1 staining was performed using an anti-MCP-1 monoclonal antibody, and it was assessed by grading the percentage of stained cells.

RESULTS

It was found that 117 breast tumor specimens (51%) had intensive staining in tumor cells. The expression of MCP-1 in tumor cells had a significant correlation with the expression of thymidine phosphorylase and membrane type 1-matrix metalloproteinase. In addition, MCP-1 expression tended to be associated with the accumulation of TAMs, which were counted by CD68 staining, and with microvessel density. MCP-1 expression in TAMs was correlated significantly with the histologic vessel invasion of tumor cells.

CONCLUSIONS

The results of this study suggest that MCP-1 may play key roles in macrophage recruitment, in the expression of angiogenic factors, and in the activation of matrix metalloproteinases in patients with breast carcinoma.

Quantification and in situ localization of MCP-1 mRNA and its relation to the immune response of renal cell carcinoma

Malignant tumours are usually accompanied by an immune response. Chemokines such as MCP-1 have been claimed to be potent inducers of such tumour-associated reactions. In the present study MCP-1 mRNA was quantified by competitive reverse transcription polymerase reaction and localised by in situ hybridisation in renal cell carcinoma tissue in comparison to tumour-free tissue of the same nephrectomy specimen. MCP-1 mRNA levels were correlated with the immune cell infiltrate, the density of CD31(+)microvessels, and the endothelial expression of ICAM-1, VCAM-1, E-, and P-selectin. In only seven of 19 cases, MCP-1 mRNA levels in carcinoma tissue were increased in comparison to tumour-free tissue. Within tumour tissue, mRNA transcripts could be localised in tumour cells, microvessel endothelia, and in tumour-associated macrophages. A correlation between MCP-1 mRNA levels and the density of immune cells, especially macrophages, the microvessel density, and the expression of adhesion molecules could not be observed. Therefore, MCP-1 seems to be of minor importance for the induction of an immune response in renal cell carcinomas regarding at least the parameters analysed in this study.

Chemokines and disease

We examine here several diseases that are associated with inappropriate activation of the chemokine network. Detailed comment has been restricted to pathological states for which there are compelling data either from clinical observations or animal models. These include cardiovascular disease, allergic inflammatory disease, transplantation, neuroinflammation, cancer and HIV-associated disease. Discussion focuses on therapeutic directions in which the rapidly evolving chemokine field appears to be headed.

Differential transcriptional regulation of the monocyte-chemoattractant protein-1 (MCP-1) gene in tumorigenic and non-tumorigenic HPV 18 positive cells: the role of the chromatin structure and AP-1 composition

The expression of the monocyte-chemoattractant-protein-1 (MCP-1) is closely linked with a non-tumorigenic phenotype in somatic cell hybrids made between the human papillomavirus type 18 (HPV 18) positive cervical carcinoma cell line HeLa and normal human fibroblasts. In contrast, MCP-1 transcription is absent in tumorigenic segregants derived from the same hybrids or in parental HeLa cells. Selectivity of MCP-1 transcription, which is regulated at the level of initiation of transcription, is mainly based on differences in the location and extension of DNAse I-hypersensitive regions (DHSR) at both ends of the gene. While TNF-alpha only moderately increases the sensitivity of pre-existing 5'-DHSRs, a 3'-end DHSR became strongly induced exclusively in non-malignant hybrids. DNA sequencing showed that the 3'-DHSR coincides with an additional AP-1 site located approximately 600 bp downstream of the polyadenylation site. Analyses of AP-1 composition revealed that MCP-1 is only expressed in those cells where jun-family members were mainly heterodimerized with the fos-related protein fra-1. In contrast, in tumorigenic cells the 1: 1 ratio between jun and fra-1 is disturbed and the MCP-1 gene is no longer expressed. Hence, alterations in the heterodimerization pattern of AP-1 and its selective accessibility to opened chromatin may represent a novel regulatory pathway in the regulation of chemokines in malignant and non-malignant HPV-positive cells.

Inactivation of interferon regulatory factor-1 tumor suppressor protein by HPV E7 oncoprotein. Implication for the E7-mediated immune evasion mechanism in cervical carcinogenesis

In studying biological roles of interferon regulatory factor (IRF)-1 tumor suppressor in cervical carcinogenesis, we found that HPV E7 is functionally associated with IRF-1. Binding assays indicate a physical interaction between IRF-1 and HPV E7 in vivo and in vitro. The carboxyl-terminal transactivation domain of IRF-1 was required for the interaction. Transient co-expression of E7 significantly inhibits the IRF-1-mediated activation of IFN-beta promoter in NIH-3T3 cells. Co-transfection of E7 mutants reveals that the pRb-binding portion of E7 is necessary for the E7-mediated inactivation of IRF-1. It was next determined whether histone deacetylase (HDAC) is involved in the inactivation mechanism as recently suggested, where the carboxyl-terminal zinc finger domain of E7 associates with NURD complex containing HDAC. When trichostatin A, an inhibitor of HDAC, was treated, the repressing activity of E7 was released in a dose-dependent manner. Furthermore, the mutation of zinc finger abrogates such activity without effect on the interaction with IRF-1. These results suggest that HPV E7 interferes with the transactivation function of IRF-1 by recruiting HDAC to the promoter. The immune-promoting role of IRF-1 evokes the idea that our novel finding might be important for the elucidation of the E7-mediated immune evading mechanism that is frequently found in cervical cancer.

Human papillomaviruses in non-melanoma skin cancer

Recent data suggest that additional factors, other than UV radiation, are involved in the etiology of non-melanoma skin cancer. These include alterations in the tumor suppressor genes, p53, p16$L*I*U$LINK4a$L*I$L/CDKN2A, p21$L*I*U$LWAF1/CIP1$L*I$L and the PTCH gene, as well as cytokines. Papillomavirus infections have been implicated in the etiology of non-melanoma skin cancer. The interaction of tumor suppressor genes and cytokines with the oncoproteins of high-risk mucosal HPV types have been studied in detail, but very little is known about the cutaneous HPV types. We have studied the effect of UV radiation on the URRs of HPV 1, 2, 3, 5, 7, 20, 23, 27, 38, 41, and 77. Neither the CAT-expression and promoter activity of these HPV types, nor presence or absence of wild-type or mutated p53 in the cell lines used, could be related to the DNA sequence homology between the different HPV types or their biological behavior.