Cyclooxygenase-2 in cervical neoplasia: A review

Significance of non-steroidal anti-inflammatory drugs in the prevention and treatment of cervical cancer

Cervical cancer, ranking as the fourth most common cancer in women globally, is closely linked to chronic inflammation resulting from persistent human papillomavirus (HPV) infection. Chronic inflammation mediated by cyclooxygenase (COX) has been identified as a factor in cancer onset and progression, with HPV oncoproteins E6 and E7 inducing COX activation. Nonsteroidal anti-inflammatory drugs (NSAIDs) have demonstrated the capability to significantly inhibit COX activity, playing a crucial preventive and therapeutic role in various tumors. This paper explores the therapeutic value and potential clinical applications of NSAIDs in cervical cancer by examining the mechanistic interactions between HPV and COX and the carcinogenic effects of COX in cervical cancer.

Aspirin intake and head and neck cancer: A pooled analysis within the INHANCE consortium

BACKGROUND

Aspirin intake might be inversely associated with head and neck cancer (HNC). Thus, we investigated this relationship within the International Head and Neck Cancer Epidemiology (INHANCE) consortium.

METHODS

Four case-control studies within the INHANCE consortium were included (2024 cases, 4196 controls). Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression and subsequently pooled with DerSimonian-Laird random-effects model. Nonlinearity of the relationship between duration of intake and HNC was modeled with fractional polynomials.

RESULTS

Aspirin was inversely associated with HNC overall (OR = 0.48; 95% CI: 0.26, 0.91). Results for laryngeal cancer were similar (OR = 0.54; 95% CI: 0.30, 0.96). Analysis on duration of intake confirmed findings for HNC overall, showing also inverse associations for oropharyngeal and laryngeal cancer.

CONCLUSIONS

This study suggests that aspirin intake may reduce the risk of HNC, driven mainly by decreases in risk for laryngeal and oropharyngeal cancer.

Hippocampal Over-Expression of Cyclooxygenase-2 (COX-2) Is Associated with Susceptibility to Stress-Induced Anhedonia in Mice

The phenomenon of individual variability in susceptibility/resilience to stress and depression, in which the hippocampus plays a pivotal role, is attracting increasing attention. We investigated the potential role of hippocampal cyclooxygenase-2 (COX-2), which regulates plasticity, neuroimmune function, and stress responses that are all linked to this risk dichotomy. We used a four-week-long chronic mild stress (CMS) paradigm, in which mice could be stratified according to their susceptibility/resilience to anhedonia, a key feature of depression, to investigate hippocampal expression of COX-2, a marker of microglial activation Iba-1, and the proliferation marker Ki67. Rat exposure, social defeat, restraints, and tail suspension were used as stressors. We compared the effects of treatment with either the selective COX-2 inhibitor celecoxib (30 mg/kg/day) or citalopram (15 mg/kg/day). For the celecoxib and vehicle-treated mice, the Porsolt test was used. Anhedonic (susceptible) but not non-anhedonic (resilient) animals exhibited elevated COX-2 mRNA levels, increased numbers of COX-2 and Iba-1-positive cells in the dentate gyrus and the CA1 area, and decreased numbers of Ki67-positive cells in the subgranular zone of the hippocampus. Drug treatment decreased the percentage of anhedonic mice, normalized swimming activity, reduced behavioral despair, and improved conditioned fear memory. Hippocampal over-expression of COX-2 is associated with susceptibility to stress-induced anhedonia, and its pharmacological inhibition with celecoxib has antidepressant effects that are similar in size to those of citalopram.

Effects of Induced Exosomes from Endometrial Cancer Cells on Tumor Activity in the Presence of Aurea helianthus Extract

Endometrial cancer (EC) cells metastasize to various regions, including the ovaries, fallopian tubes, cervix, blood, liver, bone, and brain. Various carcinogens are known to cause EC. Exosomes are released from several types of cells and contain various cellular components. In this study, flow cytometry and quantitative PCR were used to evaluate marker levels, cell migration, cell invasion, and mitochondrial membrane potential, and cellular senescence tests were used to estimate cancer activity. The microRNAs were profiled using next-generation sequencing. Although tocopherol-α and rutin content in Aurea helianthus is high, A. helianthus extract was more useful in modulating tumor activity compared to the two aforementioned substances. Notably, we established that the extract induced bioactive exosomes in EC cells, and profiling of miRNAs in the extract-inducing exosomes (EIE) indicated their potency to be developed as a biological drug. The extract and EIE contributed to the following five biological process categories for EC cells: (1) cell migration and invasion suppression, (2) cellular senescence activation by attenuating mitochondrial membrane potential and enhancing autophagy, (3) reproductive cancer activity attenuation, (4) drug susceptibility activation, and (5) EIE containing miRNAs associated with decreasing inflammation.

Antiinflammatory Medicinal Plants from the Ugandan Greater Mpigi Region Act as Potent Inhibitors in the COX-2/PGH2 Pathway

Our study investigates 16 medicinal plants via assessment of inhibition of proinflammatory enzymes such as cyclooxygenases (COX). The plants are used by traditional healers in the Greater Mpigi region in Uganda to treat inflammation and related disorders. We present results of diverse in vitro experiments performed with 76 different plant extracts, namely, (1) selective COX-2 and COX-1 inhibitor screening; (2) 15-LOX inhibition screening; (3) antibacterial resazurin assay against multidrug-resistant Staphylococcus aureus, Listeria innocua, Listeria monocytogenes, and Escherichia coli K12; (4) DPPH assay for antioxidant activity; and (5) determination of the total phenolic content (TPC). Results showed a high correlation between traditional use and pharmacological activity, e.g., extracts of 15 out of the 16 plant species displayed significant selective COX-2 inhibition activity in the PGH₂ pathway. The most active COX-2 inhibitors (IC₅₀ < 20 µg/mL) were nine extracts from Leucas calostachys, Solanum aculeastrum, Sesamum calycinum subsp. angustifolium, Plectranthus hadiensis, Morella kandtiana, Zanthoxylum chalybeum, and Warburgia ugandensis. There was no counteractivity between COX-2 and 15-LOX inhibition in these nine extracts. The ethyl acetate extract of Leucas calostachys showed the lowest IC₅₀ value with 0.66 µg/mL (COX-2), as well as the most promising selectivity ratio with 0.1 (COX-2/COX-1). The TPCs and the EC₅₀ values for DPPH radical scavenging activity showed no correlation with COX-2 inhibitory activity. This led to the assumption that the mechanisms of action are most likely not based on scavenging of reactive oxygen species and antioxidant activities. The diethyl ether extract of Harungana madagascariensis stem bark displayed the highest growth inhibition activity against S. aureus (MIC value: 13 µg/mL), L. innocua (MIC value: 40 µg/mL), and L. monocytogenes (MIC value: 150 µg/mL). This study provides further evidence for the therapeutic use of the previously identified plants used medicinally in the Greater Mpigi region.

The role of aspirin in the prevention of ovarian, endometrial and cervical cancers

Drug repurposing is the application of an existing licenced drug for a new indication and potentially provides a faster and cheaper approach to developing new anti-cancer agents. Gynaecological cancers contribute significantly to the global cancer burden, highlighting the need for low cost, widely accessible therapies. A large body of evidence supports the role of aspirin as an anti-cancer agent, and a number of randomized trials are currently underway aiming to assess the potential benefit of aspirin in the treatment of cancer. This review summarizes the evidence underpinning aspirin use for the prevention of the development and recurrence of gynaecological cancers (ovarian, endometrial and cervical) and potential mechanisms of action.

Substrate-inactivated cyclooxygenase-2 is disposed of by exosomes through the ER-Golgi pathway

Catalysis of arachidonic acid (AA) by cyclooxygenase-2 (COX-2) gives rise to a single product that serves as a precursor for all prostaglandins, which are central mediators of inflammation. Rapid up-regulation of COX-2 expression in response to pro-inflammatory stimuli is a well-characterized means of generating the large pool of prostaglandins necessary for inflammation. However, an efficient inflammatory process must also terminate rapidly and thus requires cessation of COX-2 enzymatic activity and removal of excess protein from the cell. Previous studies showed that COX-2 that has not been exposed to AA ('naive') degrades in the cellular proteasome. However, continuous exposure to AA induces suicide inactivation of COX-2 and its elimination no longer occurs in neither the proteasomal nor lysosomal machineries. In the present study, we show that either overexpressed or endogenously induced COX-2 is secreted via exosomes through the endoplasmic reticulum-Golgi pathway. We further find that excretion of COX-2 is significantly enhanced by prolonged exposure to AA. Genetic or chemical inhibition of COX-2 enzymatic activity has no effect on its secretion in the absence of substrate, but prevents the additional activity-dependent secretion. Finally, transfer of COX-2 to target cells only occurs in the absence of AA stimulation. Together, these results suggest that exosomal secretion of AA-activated COX-2 constitutes a means to remove damaged inactive COX-2 from the cell.

Cyclooxygenase-1 (COX-1) and COX-1 Inhibitors in Cancer: A Review of Oncology and Medicinal Chemistry Literature

Prostaglandins and thromboxane are lipid signaling molecules deriving from arachidonic acid by the action of the cyclooxygenase isoenzymes COX-1 and COX-2. The role of cyclooxygenases (particularly COX-2) and prostaglandins (particularly PGE₂) in cancer-related inflammation has been extensively investigated. In contrast, COX-1 has received less attention, although its expression increases in several human cancers and a pathogenetic role emerges from experimental models. COX-1 and COX-2 isoforms seem to operate in a coordinate manner in cancer pathophysiology, especially in the tumorigenesis process. However, in some cases, exemplified by the serous ovarian carcinoma, COX-1 plays a pivotal role, suggesting that other histopathological and molecular subtypes of cancer disease could share this feature. Importantly, the analysis of functional implications of COX-1-signaling, as well as of pharmacological action of COX-1-selective inhibitors, should not be restricted to the COX pathway and to the effects of prostaglandins already known for their ability of affecting the tumor phenotype. A knowledge-based choice of the most appropriate tumor cell models, and a major effort in investigating the COX-1 issue in the more general context of arachidonic acid metabolic network by using the systems biology approaches, should be strongly encouraged.

Innate immunity and HPV: friends or foes

Most human papillomavirus infections are readily cleared by the host immune response. However, in some individuals, human papillomavirus can establish a persistent infection. The persistence of high-risk human papillomavirus infection is the major risk factor for cervical cancer development. These viruses have developed mechanisms to evade the host immune system, which is an important step in persistence and, ultimately, in tumor development. Several cell types, receptors, transcription factors and inflammatory mediators involved in the antiviral immune response are viral targets and contribute to tumorigenesis. These targets include antigen-presenting cells, macrophages, natural killer cells, Toll-like receptors, nuclear factor kappa B and several cytokines and chemokines, such as interleukins, interferon and tumor necrosis factor. In the present review, we address both the main innate immune response mechanisms involved in HPV infection clearance and the viral strategies that promote viral persistence and may contribute to cancer development. Finally, we discuss the possibility of exploiting this knowledge to develop effective therapeutic strategies.

Targeted immunotherapy of high-grade cervical intra-epithelial neoplasia: Expectations from clinical trials

Targeted immunotherapy of high-grade cervical intra-epithelial neoplasia (CIN) has been developed as an alternative to conization, to preserve future reproductive outcomes and avoid human papillomavirus (HPV) persistence. The objectives of the review are to present drugs according to their process of development and to examine their potential future use. A search for key words associated with CIN and targeted immunotherapy was carried out in the Cochrane library, Pubmed, Embase, and ClinicalTrials.gov from 1990 to 2016. Publications (randomized, prospective and retrospective studies) in any language were eligible for inclusion, as well as ongoing trials registered on the ClinicalTrials.gov website. Targeted immunotherapy includes peptide/protein-based vaccines, nucleic acid-based vaccines (DNA), and live vector-based vaccines (bacterial or viral). A total of 18 vaccines were identified for treatment of CIN at various stages of development, and the majority were well-tolerated. Adverse effects were primarily injection site reactions and flu-like symptoms under grade 2. The efficacy of vaccines defined by regression of CIN2/3 to no CIN or CIN1 ranged from 17 to 59% following a minimum of a 12-week follow-up. In the majority of studies, there was no association demonstrated between histological response and HPV clearance, or between histological or virological response and immune T cell response. Given that the spontaneous regression of CIN2/3 is 20-25% at 6 months, targeted immunotherapy occurs an additional value, which never reaches 50%, with one trial an exception to this. However, research and development on HPV eradication drugs needs to be encouraged, due to HPV-associated disease burden.

Downregulation of HOTAIR Expression Mediated Anti-Metastatic Effect of Artesunate on Cervical Cancer by Inhibiting COX-2 Expression

Artesunate (ART) has anti-cancer activities for a variety of solid tumors. The aim of this study was to investigate the anti-metastatic effect of ART on cervical cancer cells. In vivo anti-metastatic effect of ART was investigated in mice with the lung metastasis model by the subcutaneous injection of ART. The interaction of HOTAIR and COX-2 was measured by RNA immunoprecipitation and RNA pull-down assay. The effect of ART on metastasis of CaSki and Hela cells was evaluated by invasion and migration assay. We found that ART inhibited cervical cancer metastasis and HOTAIR expression. HOTAIR overexpression partially abolished the anti-metastatic effect of ART on cervical cancer cells. In addition, HOTAIR can interact with COX-2 to positively regulate COX-2 expression and catalytic activity. Finally, overexpression of COX-2 reversed the effect of HOTAIR knockdown on Hela cell migration and invasion. Taken together, our data revealed that ART may elicit anti-metastatic effect against cervical cancer by inhibition of HOTAIR expression, which resulted in the decrease of COX-2 expression.

Aspirin and Acetaminophen Use and the Risk of Cervical Cancer

OBJECTIVE

In this study, we investigated whether regular use of aspirin or acetaminophen was associated with risk of cervical cancer in women treated at an American cancer hospital.

METHODS

This case-control study included 328 patients with cervical cancer and 1,312 controls matched on age and decade enrolled. Controls were women suspected of having but not ultimately diagnosed with a neoplasm. Analgesic use was defined as regular (at least once per week for ≥6 months), frequent (≥7 tablets/week), very long term (≥11 years), or frequent, long term (≥7 tablets per week for ≥5 years).

RESULTS

Compared to nonusers, frequent aspirin use was associated with decreased odds of cervical cancer (odds ratio, 0.53; 95% confidence interval, 0.29-0.97). A slightly larger association was observed with frequent, long-term use of aspirin (odds ratio, 0.46; 95% confidence interval, 0.22-0.95). Acetaminophen use was not associated with the risk of cervical cancer.

CONCLUSIONS

Our findings suggest that frequent and frequent, long-term use of aspirin is associated with decreased odds of cervical cancer. To our knowledge, this is the first US-based study examining these associations. Given the widespread use of nonsteroidal anti-inflammatory drugs and acetaminophen worldwide, further investigations of the possible role of analgesics in cervical cancer, using a larger sample size with better-defined dosing regimens, are warranted.

Novel naproxen-peptide-conjugated amphiphilic dendrimer self-assembly micelles for targeting drug delivery to osteosarcoma cells

The aim of the current study was to synthesize and prepare novel self-assembly micelles loaded with curcumin (Cur) based on naproxen (Nap)-conjugated amphiphilic peptide dendrimers.

Detection of E6-AP as a potential therapeutic target in cervical specimen of HPV-infected women

PURPOSE

Silencing of HPV oncogenes or their human host client proteins using topically applied small interfering RNA (siRNA) may be an attractive nonsurgical strategy for CIN treatment. An exploratory clinical investigation was designed to evaluate E6-AP mRNA expression levels in different stages of cervical intraepithelial neoplasia and during the menstrual cycle.

METHODS

In 38 premenopausal women aged 18-45 years referred to colposcopy clinic, analysis of serum hormones, cervical smears for cytology and HPV DNA, cervical biopsy, p16 immunohistochemistry and E6-AP mRNA expression levels in cervical smears and biopsies were performed. The intra-subject variability in E6-AP mRNA expression of vaginal smears was assessed and compared to cervical biopsy specimens.

RESULTS

RNA of sufficient quantity and quality was available for E6-AP expression analysis from 97 % of the collected cervical smears and from 56 % of the collected biopsy samples. The normalized RNA levels from cervical smears were approximately tenfold higher compared to biopsies. There was little influence by the phase of the menstrual cycle or by CIN stage. Real-time PCR showed that the expression level of E6-AP is in a range (<28 C t) that would allow for detection of at least 100-fold modulation by a therapeutic agent (based on an assay LOD of C t = 36).

CONCLUSIONS

Our findings suggest a potential therapeutic approach using E6-AP siRNA as a specific molecular target in cervical intraepithelial neoplasia.

Emerging biological treatments for uterine cervical carcinoma

Cervical cancer is the third most common cancer worldwide, and the development of new diagnosis, prognostic, and treatment strategies is a major interest for public health. Cisplatin, in combination with external beam irradiation for locally advanced disease, or as monotherapy for recurrent/metastatic disease, has been the cornerstone of treatment for more than two decades. Other investigated cytotoxic therapies include paclitaxel, ifosfamide and topotecan, as single agents or in combination, revealing unsatisfactory results. In recent years, much effort has been made towards evaluating new drugs and developing innovative therapies to treat cervical cancer. Among the most investigated molecular targets are epidermal growth factor receptor and vascular endothelial growth factor (VEGF) signaling pathways, both playing a critical role in cervical cancer development. Studies with bevacizumab or VEGF receptor tyrosine kinase have given encouraging results in terms of clinical efficacy, without adding significant toxicity. A great number of other molecular agents targeting critical pathways in cervical malignant transformation are being evaluated in preclinical and clinical trials, reporting preliminary promising data.

In the current review, we discuss novel therapeutic strategies which are being investigated for the treatment of advanced cervical cancer.

Non-steroidal anti-inflammatory drug use and cervical cancer risk: a case-control study using the Clinical Practice Research Datalink

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) have many anticarcinogenic properties via the inhibition of cyclooxygenase 2 (COX-2). Only one study, a cohort study examining risk of all cancers, investigated their role in cervical cancer with inconsistent findings between non-aspirin NSAIDs and aspirin. The aim of this study was to further investigate NSAID/aspirin use and cervical cancer risk.

METHODS

Using the United Kingdom Clinical Practice Research Datalink, 724 women diagnosed with cervical cancer between 1 January, 1995 and December 2010 were compared to 3479 women (without cervical cancer) matched on year of birth and general practice. Conditional logistic regression analysis adjusted for smoking, sexually transmitted infections, HRT and contraceptive use, was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for cervical cancer risk among users of any oral NSAIDs, non-aspirin NSAIDs and aspirin, as assessed from primary care prescribing data.

RESULTS

Excluding the year prior to diagnosis, there was no association in adjusted analyses between ever vs. never use of an NSAID (OR 0.92, 95% CI 0.77-1.09), non-aspirin NSAID (OR 0.95, 95% CI 0.80-1.13) or low-dose aspirin (OR 1.07, 0.80-1.44) and cervical cancer risk. In analysis of daily defined doses, there was no association with cervical cancer risk comparing the highest users to non-users of NSAIDs (OR 0.98, 95% CI 0.69-1.39) or non-aspirin NSAIDs (OR 1.00, 95% CI 0.70-1.43) or low-dose aspirin (OR 1.04, 95% CI 0.59-1.81).

CONCLUSION

This large historical cohort study found no evidence of an association between non-aspirin NSAID or aspirin use and cervical cancer risk.

Amygdalin induces apoptosis in human cervical cancer cell line HeLa cells

Amygdalin, a naturally occurring substance, has been suggested to be efficacious as an anticancer substance. The effect of amygdalin on cervical cancer cells has never been studied. In this study, we found that the viability of human cervical cancer HeLa cell line was significantly inhibited by amygdalin. 4,6-Diamino-2-phenyl indole (DAPI) staining showed that amygdalin-treated HeLa cells developed typical apoptotic changes. The development of apoptosis in the amygdalin-treated HeLa cells were confirmed by double staining of amygdalin-treated HeLa cells with annexin V-FITC and propidium iodide (PI) along with increase in caspase-3 activity in these cells. Further studies indicated that antiapoptotic protein Bcl-2 was downregulated whereas proapoptotic Bax protein was upregulated in the amygdalin-treated HeLa cells implying involvement of the intrinsic pathway of apoptosis. In vivo, amygdalin administration inhibited the growth of HeLa cell xenografts through a mechanism of apoptosis. The results in the present study suggest that amygdalin may offer a new therapeutic option for patients with cervical cancer.

Cyclooxygenase-1 and -2: molecular targets for cervical neoplasia

Cyclooxygenase (COX) is a key enzyme responsible for inflammation, converting arachidonic acid to prostaglandin and thromboxane. COX has at least two isoforms, COX-1 and COX-2. While COX-1 is constitutively expressed in most tissues for maintaining physiologic homeostasis, COX-2 is induced by inflammatory stimuli including cytokines and growth factors. Many studies have shown that COX-2 contributes to cancer development and progression in various types of malignancy including cervical cancer. Human papillomavirus, a necessary cause of cervical cancer, induces COX-2 expression via E5, E6 and E7 oncoproteins, which leads to prostaglandin E2 increase and the loss of E-cadherin, promotes cell proliferation and production of vascular endothelial growth factor. It is strongly suggested that COX-2 is associated with cancer development and progression such as lymph node metastasis. Many studies have suggested that non-selective COX-2 inhibitors such as non-steroidal anti-inflammatory drugs (NSAIDs), and selective COX-2 inhibitors might show anti-cancer activity in COX-2 -dependent and -independent manners. Two phase II trials for patients with locally advanced cervical cancer showed that celecoxib increased toxicities associated with radiotherapy. Contrary to these discouraging results, two phase II clinical trials, using rofecoxib and celecoxib, demonstrated the promising chemopreventive effect for patients with cervical intraepithelial neoplasia 2 or 3. However, these agents cause a rare, but serious, cardiovascular complication in spite of gastrointestinal protection in comparison with NSAIDs. Recent pharmacogenomic studies have showed that the new strategy for overcoming the limitation in clinical application of COX-2 inhibitors shed light on the use of them as a chemopreventive method.

Angiotensin II activates the calcineurin/NFAT signaling pathway and induces cyclooxygenase-2 expression in rat endometrial stromal cells

Cyclooxygenase (COX)-2, the inducible isoform of cyclooxygenase, plays a role in the process of uterine decidualization and blastocyst attachment. On the other hand, overexpression of COX-2 is involved in the proliferation of the endometrial tissue during endometriosis. Deregulation of the renin-angiotensin-system plays a role in the pathophysiology of endometriosis and pre-eclampsia. Angiotensin II increases intracellular Ca(2+) concentration by targeting phospholypase C-gamma in endometrial stromal cells (ESC). A key element of the cellular response to Ca(2+) signals is the activity of the Ca(2+)- and calmodulin-dependent phosphatase calcineurin. Our first aim was to study whether angiotensin II stimulated Cox-2 gene expression in rat ESC and to analyze whether calcineurin activity was involved. In cells isolated from non-pregnant uteri, COX-2 expression--both mRNA and protein--was induced by co-stimulation with phorbol ester and calcium ionophore (PIo), as well as by angiotensin II. Pretreatment with the calcineurin inhibitor cyclosporin A inhibited this induction. We further analyzed the role of the calcineurin/NFAT signaling pathway in the induction of Cox-2 gene expression in non-pregnant rat ESC. Cyclosporin A abolished NFATc1 dephosphorylation and translocation to the nucleus. Cyclosporin A also inhibited the transcriptional activity driven by the Cox-2 promoter. Exogenous expression of the peptide VIVIT -specific inhibitor of calcineurin/NFAT binding- blocked the activation of Cox-2 promoter and the up-regulation of COX-2 protein in these cells. Finally we analyzed Cox-2 gene expression in ESC of early-pregnant rats. COX-2 expression--both mRNA and protein--was induced by stimulation with PIo as well as by angiotensin II. This induction appears to be calcineurin independent, since it was not abrogated by cyclosporin A. In conclusion, angiotensin II induced Cox-2 gene expression by activating the calcineurin/NFAT signaling pathway in endometrial stromal cells of non-pregnant but not of early-pregnant rats. These results might be related to differential roles that COX-2 plays in the endometrium.

Oral contraceptive and progestin-only use correlates to tissue tumor marker expression in women with cervical intraepithelial neoplasia

BACKGROUND

The study was conducted to investigate correlations between combined oral contraceptive (COC), any progestin-only contraceptive, medicated intrauterine device (MID) or systemic progestin-only (Syst-P) use and tumor marker expression in cervical intraepithelial neoplasia compared to nonusers.

STUDY DESIGN

One-hundred ninety-five women of fertile age with cervical biopsies ranging histologically from normal epithelium to carcinoma in situ were recruited consecutively. Combined oral contraceptive, Syst-P and MID users were investigated according to the expression of 11 tumor markers.

RESULTS

Overexpression of cyclooxygenase-2 (Cox-2) was observed in COC users, while interleukin 10 was underexpressed. When users of progestogen-only contraceptives were analyzed, there was a lower expression of cytokeratin 10 and interleukin 10. When only MID users were analyzed, a high expression of p53 was found. Expression of Cox-2, p53 and retinoblastoma protein differed between COC and MID users.

CONCLUSION

The study showed molecular alterations, which, in general, have not been studied previously in COC users and have never been studied in progestogen-only users. These biological events might be involved in epidemiological correlations found between hormonal contraceptive use and cervical neoplasms.

Regulation of immune responses to HPV infection and during HPV-directed immunotherapy

The recent development of vaccines prophylactic against human papillomavirus (HPV) infection has the potential to reduce the incidence of cervical cancer globally by up to 70% over the next 40 years, if universal immunization is adopted. As these prophylactic vaccines do not alter the natural history of established HPV infection, immunotherapies to treat persistent HPV infection and associated precancers would be of benefit to assist with cervical cancer control. Efforts to develop immuno-therapeutic vaccines have been hampered by the relative non-immunogenicity of HPV infection, by immunoregulatory processes in skin, and by subversion of immune response induction and immune effector functions by papillomavirus proteins. This review describes HPV-specific immune responses induced by viral proteins, their regulation by host and viral factors, and highlights some conclusions from our own recent research.

Prognostic relevance of cyclooxygenase-2 (COX-2) expression in Chinese patients with prostate cancer

Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, has been reported to be correlated with tumorigenesis, tumor progression and metastasis. The present study was designed to investigate the clinicopathological and prognostic significance of COX-2 in Chinese patients with prostate cancer. Firstly, RT-PCR and Western blot assays were performed to detect the expression of COX-2 mRNA and protein in prostate cancer cell lines and 20 tissue samples (tumor or corresponding non-tumor). Next, immunohistochemistry was performed to detect the expression of COX-2 protein in 88 prostate cancer tissue samples. Finally, the correlation between COX-2 expression and clinicopathological factors and patient survival was evaluated. We found that the expression levels of COX-2 mRNA and protein showed significant difference among four prostate cancer cell lines. Moreover, the levels of COX-2 mRNA and protein were significantly higher in prostate cancer tissues than in corresponding non-tumor tissues. COX-2 staining was positive in the cytoplasm of prostate cancer cells. High-COX-2 expression was correlated with the Gleason score (P=0.009), tumor stage (P=0.012), and lymph-node status (P=0.036). Furthermore, patients with high-COX-2 expression showed lower disease-free (P=0.014) and overall survival (P=0.047) rates than those with low-COX-2 expression. Univariate and multivariate analyses suggested that the status of COX-2 protein expression was an independent prognostic indicator for patients' survival. Taken together, higher COX-2 protein expression might provide an independent prognostic marker for Chinese patients with prostate cancer who have undergone surgery.

Cyclooxygenase-2 gene and epithelial ovarian carcinoma risk

In this study, we aimed to investigate a possible association of the COX-2 polymorphisms (-765G→C and -1195A→G) and with the risk of developing epithelial ovarian carcinoma (EOC). COX-2 gene polymorphisms was investigated in 111 healthy women and 57 patients with EOC. Individuals who had -765 CG, -1195 AA genotype, and -765 C allele had increased risk for ovarian carcinoma (P < 0.01) and individuals with -765 GG, -1195 AG genotypes and -1195 G allele seem to be protected from ovarian carcinoma (P < 0.01). Haplotype analysis confirmed the association of COX-2 gene variants with ovarian carcinoma and revealed that the frequencies of -765C: -1195A haplotype frequencies was significantly higher in patients as compared with those of controls (P = 0.048). We state that there appears to be a modulating role for the COX-2 -1195A→G and -765G→C polymorphisms in the development of EOC. To the best of our knowledge, this is the first study to show such an association.

Tissue tumor marker expression in smokers, including serum cotinine concentrations, in women with cervical intraepithelial neoplasia or normal squamous cervical epithelium

OBJECTIVE

The purpose of this study was to investigate correlations between smoking and serum cotinine, respectively, and tumor marker expression in cervical intraepithelial neoplasia (CIN) and normal epithelium.

STUDY DESIGN

Women (n = 228) with cervical biopsy specimens that ranged histologically from normal to carcinoma in situ (CIN III) were included. Expression of 11 tumor markers with possible relevance in cervical neoplasms was studied. Smoking habits were recorded, and serum was assessed for cotinine concentrations.

RESULTS

No differences were found in tumor marker expression in normal epithelium between smokers and nonsmokers. The tumor suppressors p53 and fragile histidine triad and the immunologic marker interleukin-10 were underexpressed, and the tumor markers cyclooxygenase-2 and Ki-67 were overexpressed in smoking, compared with nonsmoking, women with CIN and particularly in all fertile women.

CONCLUSION

The molecular pattern indicates that smoking exerts unfavorable effects in cervical neoplasia. This provides biologic evidence of smoking being a true cofactor in cervical neoplasia.

GalNAcalpha1-3Gal, a new prognostic marker for cervical cancer

Cancer cells undergo significant changes in carbohydrate expression, and these alterations can be useful as biomarkers and therapeutic targets. In this study, we investigated the expression of carbohydrate antigens containing a terminal GalNAcalpha1-3Gal or GalNAcalpha1-6Gal on human cervix and cervical carcinoma. Monoclonal antibodies to each of these carbohydrates were generated by immunizing rabbits with the corresponding antigen conjugated to KLH followed by hybridoma production. Antibodies were screened and evaluated using a combination of carbohydrate microarray profiling, ELISA, dot blot and immunohistochemical staining to verify specificity. Antibody 132-3 was found to selectively recognize GalNAcalpha1-3Gal with little cross-reactivity to other structurally similar antigens such as GalNAcalpha1-6Gal, blood group A, Forssman antigen and the Tn antigen on both solution assays and human tissue. Although GalNAcalpha1-6Gal expression was not detected, GalNAcalpha1-3Gal expression was found on 55% of squamous cell carcinomas. Expression in normal tissue was observed but was restricted to the suprabasal epithelial layer. Importantly, we found expression of the antigen on cervical cancer had a statistically significant correlation with the 5-year survival rate of the patients (48 vs. 85% for antigen negative vs. positive, p = 0.017). Expression of GalNAcalpha1-3Gal did not correlate with other clinical factors including tumor stage, size and lymph node metastasis, indicating the antigen is a new, independent biomarker for the prognosis of cervical cancer.

Current advancement in radiation therapy for uterine cervical cancer

Radiation therapy is one of the effective curative treatments for uterine cervical cancer. However poor clinical results for the advanced stages require further improvement of the treatment. Intensive studies on basic and clinical research have been made to improve local control, primarily important for long term survival in radiation therapy. Regarding current advancement in radiation therapy for uterine cervical cancer, the following three major subjects are pointed out; technological development to improve dose distribution by image guided radiation therapy technology, the concomitant anticancer chemotherapy with combination of radiation therapy, and radiation biological assessment of the radiation resistance of tumors. The biological factors overviewed in this article include hypoxia relating factors of HIF-1alpha, SOD, cell cycle parameters of pMI, proliferation factors of Ki67, EGFR, cerbB2, COX-2, cycle regulation proteins p53, p21, apoptosis regulation proteins Bcl2 and Bax and so on. Especially, the variety of these radiation biological factors is important for the selection of an effective treatment method for each patient to maximize the treatment benefit.

Cox-2 expression in ovarian malignancies: a review of the clinical aspects

COX-2 is an inducible enzyme expressed only in response to stimuli such as mitogens, cytokines, growth factors or hormones, and is pro-inflammatory. It plays an important role in tumorigenesis. The purpose of the present report is to review the clinical aspects of COX-2 expression in ovarian malignancies. A PubMed (http://www.pubmed.gov/) search of investigations published from July 2001 until August 2008 and containing the term COX-2 in combination with ovarian malignancies was conducted. The clinical aspects of the relevant investigations were reviewed. COX-2 is expressed in ovarian tumors of low malignant potential (LMP), in epithelial ovarian carcinoma (EOC) and primary peritoneal carcinoma (PPC) and apparently plays a role in their carcinogenesis. Its expression seems to be correlated with VEGF that serves as a predictor of poor prognosis in some non-gynecologic malignancies. COX-2 expression is higher in EOC than in LMPs. The results with regard to the association between COX-2 expression and prognostic factors, response to treatment and outcome in ovarian malignancies are inconsistent. Clinical studies dealing with the effect of COX-2 inhibitors on outcome are scarce. The use of COX-2 expression in gynecological malignancies in clinical practice remains to be elucidated.

G protein-coupled receptor connectivity to NF-kappaB in inflammation and cancer

Complex intracellular network interactions regulate gene expression and cellular behavior. Whether at the site of inflammation or within a tumor, individual cells are exposed to a plethora of signals. The transcription factor nuclear factor-kappaB (NF-kappaB) regulates genes that control key cellular activities involved in inflammatory diseases and cancer. NF-kappaB is regulated by several distinct signaling pathways that may be activated individually or simultaneously. Multiple ligands and heterologous cell-cell interactions have an impact on NF-kappaB activity. The G protein-coupled receptor (GPCR) superfamily makes up the largest class of transmembrane receptors in the human genome and has multiple molecularly distinct natural ligands. GPCRs regulate proliferation, differentiation, and chemotaxis and play a major role in inflammatory diseases and cancer. Both GPCRs and NF-kappaB have been, and continue to be, major targets for drug discovery. A clear understanding of network interactions between GPCR signaling pathways and those that control NF-kB may be valuable for the development of better drugs and drug combinations.

Silica-lipid hybrid (SLH) microcapsules: a novel oral delivery system for poorly soluble drugs

A silica-lipid hybrid (SLH) microcapsule system for oral delivery of poorly water-soluble drugs is reported for the first time. For the model drug celecoxib (CEL), SLH microcapsules composed of medium-chain triglycerides, lecithin and silica nanoparticles; with an internal porous matrix structure, were shown to offer several physicochemical and biopharmaceutical advantages in comparison with unmodified drug, lipid emulsion, dry emulsion and the commercial product, Celebrex. DSC and XRD analyses confirmed non-crystalline CEL in SLH microcapsules and verified medium term physical stability. Dissolution under sink conditions revealed a 2- to 5-fold increase in dissolution efficiencies (%DE) and significantly reduced t(50%) (> or =50-fold) for CEL formulated as SLH microcapsules. Orally dosed in vivo studies in rats demonstrated superior pharmacokinetics for SLH microcapsules. Specifically, the fasted-state bioavailability (F) was statistically higher (p<0.05) than for aqueous suspension, lipid solution, o/w emulsion and a maltodextrin-stabilised dry emulsion, and was greater than for Celebrex. SLHs showed the highest maximum plasma concentration (C(max)) among all tested formulations (p<0.05). Linear correlations were observed between %DE and the pharmacokinetic parameters (F and C(max)). It is postulated that SLH microcapsules improve CEL oral absorption via dissolution enhancement, potentially in conjunction with other unexplored mechanisms, hence offering the possibility of dose reduction for improved therapeutic efficacy and cost-effectiveness of poorly soluble drugs.