Prevention of cervix cancer

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

Simple Summary

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

Abstract

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

Comparative Assessment of Women's Reproductive Health in the Areas Bordering With the Aral Sea Region

AIM:

We examined 435 women of Aktobe region and 328 women of South Kazakhstan region, living in areas bordering the Aral Sea region during the study and comparative assessment of the impact of climatic and anthropogenic factors of Aral region on the reproductive health of the female population.

MATERIAL AND METHODS:

The survey based on the comprehensive clinical-functional and laboratory studies accounting the regional and environmental ecological factors. Survey subject was the area of 2 settlements of Aktobe region and 1 settlement of South Kazakhstan region.

RESULTS:

In all three areas it was revealed that the examined women had the later menarche. There is a trend towards younger age for menopause. The women of South Kazakhstan region often suffer from the pelvic inflammatory disease.

CONCLUSION:

Perinatal losses, the case of spontaneous interruption and stagnant pregnancy in history, which can be repeated, one in three women has in the zone of ecological disaster.

Cytokines of Cervical Mucosa and Human Papilloma Virus Infection of the Cervix: A Descriptive Study

OBJECTIVE

The production of cytokines by various cervical cells can be triggered by antigenic stimuli, including human papilloma virus (HPV) infection. The aim of the present study was to evaluate differences in cytokine levels between various intraepithelial cervical lesions.

STUDY DESIGN

A total of 97 women participated in this descriptive study. Within our study population, 27 subjects presented with high-grade squamous intraepithelial lesions (HSIL), 48 with low-grade squamous intraepithelial lesion (LSIL) and 22 with a normal smear. Colposcopy and directed biopsy were performed as needed. To confirm the presence of HPV, an HPV-DNA test was performed using polymerase chain reaction. Using flow cytometry to ThinPrep cervical samples, we assessed the family of interleukins (ILs), including IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor (TNF)-α and TNF-β and transforming growth factor-β1. Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS for Windows; version 20.0).

RESULTS

Significantly lower levels of IL-1α, IL-2, IL-4 and TNF-α were detected in cervical samples obtained from the LSIL group when compared to samples obtained from the HSIL group.

CONCLUSION

Significant differences in tissue cytokine levels exist between intraepithelial cervical lesions obtained from patients presenting with HSIL versus LSIL.

Role of IL-12p40 in cervical carcinoma

BACKGROUND

Previously, we have shown that low IL-12p40 mRNA expression by cervical cancer cells is associated with a poor survival of cervical cancer patients. As IL-12p40 is both a subcomponent of interleukin (IL)-12 and IL-23, the aim of this study was to elucidate the role of IL-12p40 in cervical cancer.

METHODS

We have measured the expression of IL-23p19 mRNA, IL-12p35 mRNA and IL-12p40 mRNA using mRNA in situ hybridisation. The IL-1 and IL-6 were measured by immunohistochemistry.

RESULTS

As IL-23 is a component of the IL-17/IL-23 pathway, a pathway induced by IL-1 and IL-6 in humans, we have studied IL-1 and IL-6 expression. Only a high number of stromal IL-6-positive cells was shown to associate with poor disease-specific survival. The worst disease-specific survival was associated with a subgroup of patients that displayed a high number of IL-6-positive cells and low IL-12p40 expression (P<0.001). Both a high number of IL-6-positive cells and a high number of IL-6-positive cells, plus low IL-12p40 expression were shown to be clinicopathological parameters independent of lymph node metastasis, parametrial involvement and Sedlis score (P=0.009 and P=0.007, respectively).

CONCLUSION

Our results with IL-6 and IL-12p40 are in accordance with the hypothesis that the IL-17/IL-23 pathway has a suppressive role in cervical cancer.

Association between carotenoids and outcome of cervical intraepithelial neoplasia: a prospective cohort study

BACKGROUND

It has been suggested that micronutrients such as alpha-tocopherol, retinol, lutein, cryptoxanthin, lycopene, and alpha- and beta-carotene may help in the prevention of cervical cancer. Our aim was to investigate whether serum concentrations and/or dietary intake of micronutrients influence the regression or progression of low-grade cervical abnormalities.

METHODS

In a prospective cohort study of 391 patients with cervical intraepithelial neoplasia (CIN) grade 1-2 lesions, we measured serum micronutrient concentrations in addition to a self-administered questionnaire about dietary intake. We evaluated the hazard ratio (HR) adjusted for CIN grade, human papillomavirus genotype, total energy intake and smoking status.

RESULTS

In non-smoking regression subjects, regression was significantly associated with serum levels of zeaxanthin/lutein (HR 1.25, 0.78-2.01, p = 0.024). This benefit was abolished in current smokers. Regression was inhibited by high serum levels of alpha-tocopherol in smokers (p = 0.042). In progression subjects, a significant protective effect against progression to CIN3 was observed in individuals with a medium level of serum beta-carotene [HR 0.28, 95 % confidence interval (CI) 0.11-0.71, p = 0.007), although any protective effect from a higher level of serum beta-carotene was weaker or abolished (HR 0.52, 95 % CI 0.24-1.13, p = 0.098). Increasing beta-carotene intake did not show a protective effect (HR 2.30, 95 % CI 0.97-5.42, p = 0.058).

CONCLUSIONS

Measurements of serum levels of carotenoids suggest that regression is modulated by smoking status. Maintaining a medium serum level of beta-carotene has a protective effect for progression; however, carotene intake is not correlated with serum levels of carotenoids.

Ethnic differences in predictors of HPV vaccination: comparisons of predictors for Latina and non-Latina White women

The purpose of this study was to examine how social and behavioral factors such as age of first intercourse, mother-daughter communication, and perceived norms are associated with human papillomavirus (HPV) vaccination behaviors, and whether ethnicity moderates those associations (non-Latina White versus Latina participants). From June through December 2009, we surveyed a community sample of 309 White and Latina women, ages 15 to 30. We recruited participants from local health care clinics in Des Moines, Iowa. Vaccination status was not significantly different for Whites versus Latinas. The effects of age at first intercourse, mother-daughter communication about values related to sex, and descriptive norms of HPV vaccine uptake were all significantly moderated by ethnicity. The current findings reveal that sociocultural and behavioral factors that affect HPV vaccine uptake do not affect White and Latina women in the same fashion. In the future, public health campaigns about HPV and the HPV vaccine may be more effective if their messages are sensitive to these differences.

Cancer risk models and preselection for screening

OBJECTIVE

The invitation to population screening is based on age criteria in many countries. Screening is not offered to younger or older participants, because the benefits in these age groups do not outweigh the harms. One could argue that it is not so much age that determines the benefits but the risk of developing preclinical and treatable cancer. Cancer risk varies with age but is also affected by other factors.

METHODS

We performed a systematic review for risk models for the three types of cancer for which population screening programs exist: breast, cervical and colon cancer. We used an evaluation scheme that distinguishes three phases of model development: model derivation, validation and impact analysis. Data were collected in August 2010.

RESULTS

We identified two colorectal, four breast and three cervix cancer risk models. One colorectal, four breast and none of the cervix cancer models have been externally validated. We could not identify evaluations of the impact on population screening effectiveness.

CONCLUSION

We conclude that risk models for the pre-selection of screening have been developed. These models could improve the pre-selection for screening, help in making personal decisions about participation, and reduce adverse effects of population screening. The validity of this hypothesis, as well as practicalities and issues of equity and reliability, have to be tested in further studies.

Development of a theory-based (PEN-3 and Health Belief Model), culturally relevant intervention on cervical cancer prevention among Latina immigrants using intervention mapping

The development of efficacious theory-based, culturally relevant interventions to promote cervical cancer prevention among underserved populations is crucial to the elimination of cancer disparities. The purpose of this article is to describe the development of a theory-based, culturally relevant intervention focusing on primary (sexual risk reduction) and secondary (Pap smear) prevention of cervical cancer among Latina immigrants using intervention mapping (IM). The PEN-3 and Health Belief Model provided theoretical guidance for the intervention development and implementation. IM provides a logical five-step framework in intervention development: delineating proximal program objectives, selecting theory-based intervention methods and strategies, developing a program plan, planning for adoption in implementation, and creating evaluation plans and instruments. We first conducted an extensive literature review and qualitatively examined the sociocultural factors associated with primary and secondary prevention of cervical cancer. We then proceeded to quantitatively validate the qualitative findings, which led to development matrices linking the theoretical constructs with intervention objectives and strategies as well as evaluation. IM was a helpful tool in the development of a theory-based, culturally relevant intervention addressing primary and secondary prevention among Latina immigrants.

Clinical trials of antioxidants as cancer prevention agents: past, present, and future

The purpose of this review is to summarize the most important human clinical trials of antioxidants as cancer prevention agents conducted to date, provide an overview of currently ongoing studies, and discuss future steps needed to advance research in this field. To date there have been several large (at least 7000 participants) trials testing the efficacy of antioxidant supplements in preventing cancer. The specific agents (diet-derived direct antioxidants and essential components of antioxidant enzymes) tested in those trials included β-carotene, vitamin E, vitamin C, selenium, retinol, zinc, riboflavin, and molybdenum. None of the completed trials produced convincing evidence to justify the use of traditional antioxidant-related vitamins or minerals for cancer prevention. Our search of ongoing trials identified six projects at various stages of completion. Five of those six trials use selenium as the intervention of interest delivered either alone or in combination with other agents. The lack of success to date can be explained by a variety of factors that need to be considered in the next generation research. These factors include lack of good biological rationale for selecting specific agents of interest; limited number of agents tested to date; use of pharmacological, rather than dietary, doses; and insufficient duration of intervention and follow-up. The latter consideration underscores the need for alternative endpoints that are associated with increased risk of neoplasia (i.e., biomarkers of risk), but are detectable prior to tumor occurrence. Although dietary antioxidants are a large and diverse group of compounds, only a small proportion of candidate agents have been tested. In summary, the strategy of focusing on large high-budget studies using cancer incidence as the endpoint and testing a relatively limited number of antioxidant agents has been largely unsuccessful. This lack of success in previous trials should not preclude us from seeking novel ways of preventing cancer by modulating oxidative balance. On the contrary, the well demonstrated mechanistic link between excessive oxidative stress and carcinogenesis underscores the need for new studies. It appears that future large-scale projects should be preceded by smaller, shorter, less expensive biomarker-based studies that can serve as a link from mechanistic and observational research to human cancer prevention trials. These relatively inexpensive studies would provide human experimental evidence for the likely efficacy, optimum dose, and long-term safety of the intervention of interest that would then guide the design of safe, more definitive large-scale trials.

Selective suppression of cervical cancer Hela cells by 2-O-β-D-glucopyranosyl-L-ascorbic acid isolated from the fruit of Lycium barbarum L

Lycium barbarum fruit has been used as a Chinese traditional medicine and dietary supplement for centuries. 2-O-β-D-Glucopyranosyl-L-ascorbic acid (AA-2βG), a novel stable vitamin C analog, is one of the main biologically active components of the fruit. In this report, we investigated the cytotoxic and antiproliferative effect of AA-2βG against cancer cells in vitro and identified the proteins with significantly differential expression in the cervical cancer cells (Hela) cultured in the presence of AA-2βG proteomic analysis. Our results demonstrated that the cytotoxic and antiproliferative activity of AA-2βG on cancer cell lines were in a cell type-, time-, and dose-dependent manner. Similar to vitamin C, the AA-2βG selectively induced cell death repressed the proliferation of Hela cells by the mechanism of cell apoptosis and cell cycle arrest induced by AA-2βG through a mechanism of stabilizing p53 protein. However, the biological activity of inhibition of cell proliferation in other malignant cancer cell lines or primary cells were varied, as demonstrated by either moderate inhibition or slight promotion following treatment with AA-2βG. Comparative analysis of the proteomic profiles and immunoblot analysis identified 15 proteins associated with repressing cell apoptosis and/or stimulating cell proliferation in Hela cells that were downregulated in the presence of AA-2βG or vitamin C. These data indicate that a mechanism of the AA-2βG and vitamin C mediated antitumor activity by downregulating the expression of proteins involved in cell apoptosis and proliferation and consequently inducing Hela cell apoptosis and cell cycle arrest, suggesting that AA-2βG and vitamin C may share a similar mechanism of inducing Hela cell apoptosis. These results also suggest that the L. barbarum fruit may be a potential dietary supplement and anticancer agent aimed at the prevention and treatment of cervical cancer.

Prevalence of human papillomavirus infection among women with and without normal cervical histology in Shandong Province, China

OBJECTIVE

The purpose of this study was to investigate the prevalence of human papillomavirus (HPV) genotypes infection in women with and with normal cervical histology in the littoral region of Shandong, China.

METHODS

Scrape specimens were collected from 4,601 women for Pap smear and HPV genotypes identification. 1,489 women without normal cytology or with cervical disease were referred for colposcopic examination and biopsy procedures.

RESULTS

The HPV infection in healthy women of the littoral region of Shandong (9.61%) is lower than that observed in previous studies in China and much less than in the high-risk areas. HPV infection prevalence was 14.23% in cervicitis with normal cervical histology, which was significantly lower than that of the women without normal cervical histology (60.12%, P = 0.00). Compared to prevalence of high-risk (HR) HPV genotypes (11.04%) in cervicitis with normal cervical histology, HR HPV genotypes prevalence (59.82%) was significantly higher in women without normal cervical histology (P = 0.003). HPV types 16, 52, 58, and 31 were the most prevalent HPV genotypes found in women without normal cervical histology. No statistical difference was observed for multiple HR HPV genotypes infection between women with and without normal cervical histology (P = 0.892).

CONCLUSION

Compared with prevalence rates for other populations, the prevalence of specific-HPV genotypes infecting women is different in the littoral region of Shandong Province, China.

Successful photodynamic therapy with topical 5-aminolevulinic acid for five cases of cervical intraepithelial neoplasia

OBJECTIVES

Photodynamic therapy (PDT) is a minimally invasive treatment for cervical intraepithelial neoplasia. The purpose of this study was to assess the feasibility and effectiveness of PDT in patients with CIN and high-risk HPV infection.

METHODS

Five patients diagnosed CIN 2 or CIN 3 with human papillomavirus (HPV) infection were included. Each patient had gynecologic examination including cervical cytology, HPV DNA testing, colposcopy and biopsy. Two grams of 5-aminolevulinic acid (ALA) gel (118 mg/g) was topically applied to the cervix and covered with a special plastic cap for 3-4 h, followed by 20 min illumination of both ecto- and endo-cervical canal with red coherent light (wavelength 633 nm) using a PDT laser and a special light catheter. The PDT therapy was repeated with an interval of 1 week. Follow-up examination including biopsy and histology, colposcopy, HPV DNA testing were carried out after 3, 6 and 9 months.

RESULTS

Treatment could be accomplished in all cases and no severe side effect was encountered. All the CIN2 patients had a complete response for 9 months and one CIN3 HPV remained positive for 6 months after three or four treatments.

CONCLUSION

PDT seems to be a non-invasive, repeatable procedure for CIN and cervical HPV infection with minimal side effects and can be easily performed on outpatient basis.

Syzygium cumini inhibits growth and induces apoptosis in cervical cancer cell lines: a primary study

Cervical cancer is common among women in the Indian subcontinent and the incidences and death rates are gradually increasing over the years. Several dietary phytochemicals have been reported to have growth inhibitory and apoptotic effect on HeLa and other cervical cell lines. In this study, using Hoechst 33342 staining, MTT, Annexin V-FLUOS/PI and TUNEL assays we demonstrated that Syzygium cumini extract inhibits the growth and induces apoptosis in HeLa and SiHa cervical cancer cell lines in a dose- and time-dependent manner. The phytochemical, its mode of action and safety issues are yet to be determined.

Role of tumor-derived proinflammatory cytokines GM-CSF, TNF-alpha, and IL-12 in the migration and differentiation of antigen-presenting cells in cervical carcinoma

BACKGROUND

Proinflammatory cytokines are important in modifying the activity, differentiation, and migration of antigen-presenting cells and may influence the survival of cancer patients. The study assessed whether GM-CSF, TNF-alpha, and IL-12, produced by cervical cancer cells, are important for the activity, differentiation, and migration of antigen-presenting cells.

METHODS

In 90 patients with cervical carcinoma the number of monocytes/tumor-associated macrophages (TAM), mature dendritic cells (DC), and Langerhans cells (LHC) was determined using immunohistochemistry. An RNA in situ hybridization technique was used to measure the expression level of GM-CSF, TNF-alpha, IL-12p35, and IL-12p40.

RESULTS

TAM were detected intraepithelial as well as in the stroma of the tumor. LHC were only detected intraepithelial and mature DC only in the tumor stroma. The number of TAM correlated positively with the number of mature DC. The expression levels of GM-CSF and TNF-alpha correlated positively with the number of TAM and DC. TNF-alpha showed a negative correlation with the number of LHC. A significant correlation between the expression of functional IL-12 (IL-12p40) and stromal TAM was found. The expression of GM-CSF, TNF-alpha, and IL-12p40 did not correlate significantly with disease-free survival. However, high IL-12p40 expression was associated with a favorable cumulative overall survival.

CONCLUSIONS

The results suggest that GM-CSF as well as TNF-alpha, produced by cervical carcinoma cells, may play a role in the differentiation of monocytes into mature DC. Furthermore, TNF-alpha may influence the migration of LHC from the tumor.

Vaccination HPV: principes, résultats et perspectives

Human papillomavirus (HPV) are responsible of an important morbidity and mortality. HPV is a significant source of morbidity and mortality. HPV is the most common sexually transmitted infection: adolescents are at high-risk for HPV acquisition. Biologic and epidemiologic studies have demonstrated that HPV infection is a necessary but non-sufficient cause of cervical cancer and genital warts. The vast majority of cervical cancers contain high-risk HPV type and approximately 70% contain HPV types 16 or 18. HPV types 6 or 11 are responsible for approximately 90% of genital warts. Thus, a vaccine that could prevent. Prophylactic vaccines based on the use of virus-like particles (VLPs) obtained by auto-assembly of L1 are under clinical trials. Two vaccines are currently evaluated: Cervarix (GlaxoSmithKline Biologics), a bivalent vaccine against HPV 16 and 18, and Gardasil (Merck & Co) a quadrivalent vaccine against HPV 16, 18, 6, and 11. Phase I, II and III studies have demonstrated that both vaccines are well tolerated and provide an excellent immunogenicity. With approximately 5-year follow-up, both vaccines have been effective in preventing persistent infection with targeted HPV types and in preventing cervical intraepithelial lesions. The optimal target for vaccination is probably 12-year-old girls.

Anal intraepithelial neoplasia

Background

Anal intraepithelial neoplasia (AIN) is believed to be a precursor of anal squamous cell cancer and its incidence is rising in high-risk groups, particularly those infected with the human immunodeficiency virus (HIV). The natural history of AIN is unclear and management strategies are lacking.

Methods

This review is based on a literature search (Medline and PubMed) with manual cross-referencing of all articles related to AIN.

Results and conclusions

The aetiology of AIN is intricately linked with human papilloma viruses. The pathological processes involved in the progression of AIN are becoming clearer but the natural history, particularly the rate of progression to invasive cancer, remains unknown. There is no standard management for AIN and this is mainly due to difficulties in both diagnosis and treatment. A variety of treatment options have been tried with varying success. Surgery is associated with significant recurrence, particularly in HIV-positive patients. Non surgical approaches with imiquimod, photodynamic therapy and vaccination are appealing, and further work is required. Long-term follow-up of these patients is essential until the natural history of AIN becomes clearer.

Prophylactic human papillomavirus vaccines: the beginning of the end of cervical cancer

Persistent infection with one of the oncogenic human papillomavirus (HPV) types is a necessity for the development of cervical cancer. By HPV vaccination, cervical cancer could become a very rare disease. Two types of HPV vaccines can be distinguished: (i) therapeutic vaccines which induce cellular immunity targeted against epithelial cells infected with HPV and (ii) prophylactic vaccines inducing virus-neutralizing antibodies protecting against new but not against established infections. At present, several vaccines have been developed and tested in clinical trials. The vaccines are generally well tolerated and highly immunogenic. The current clinical data indicate that prophylactic vaccines are very effective against new persistent infections and the development of cervical intraepithelial lesions. The protection is type specific. However, the follow-up of the vaccination trials is still short. The effect of HPV vaccines on future cancer incidence will only be known after decades of follow-up. This article will address the status of recently terminated phase II and currently running phase III trials with prophylactic HPV vaccines.

Prevalence and risk factors of human papilloma virus infection in asymptomatic women in southeastern Hungary

A survey was carried out to determine the prevalence of genital human papilloma virus (HPV) infection in asymptomatic women. The overall prevalence of HPV infection was 23%. Age (under 24 years), pathological cytology were significantly associated with exposure to HPV infection. HPV screening is important for young women, especially, where there is a pathological cytological diagnosis.

Cancer of the Uterine Cervix

HEALTH ISSUE: Cervical cancer is one of the most common malignant diseases of women; it is diagnosed in almost half a million women every year and half as many die from it annually. In Canada and other industrialized countries, its incidence has decreased due to cytology screening. However, invasive cases still occur, particularly among immigrant groups and native Canadian women. Although incidence of squamous cell carcinomas has decreased, the proportion of adenocarcinomas has increased because Pap cytology is ineffective to detect these lesions. KEY FINDINGS: In Canada, cervical cancer will cause an estimated 11,000 person-years of life lost. In most Canadian provinces, early detection is dependent on opportunistic screening. Primary prevention can be achieved through health education (sexual behavior modification) and vaccination to prevent infection from Human Papillomavirus (HPV). The initial results from vaccination trials are encouraging but wide scale use is more than a decade away. DATA GAPS AND RECOMMENDATIONS: Most cases of cervical cancer occur because the Pap smear was either false negative, was not done or not done often enough. Appropriate recommendations and guidelines exist on implementation of cytology-based programs. However, most Canadian women do not have access to organized screening. Further research is needed to 1) evaluate automated cytology systems; 2) define appropriate management of precursor lesions and 3) deliver definitive evidence of HPV testing efficacy in long-term follow-up studies with invasive cancer as an outcome and 4) provide Canadian data to justify augmenting or modifying current programs to use HPV testing in secondary triage of equivocal Pap smears.

Alpha-tocopherol and alpha-tocopheryl quinone levels in cervical intraepithelial neoplasia and cervical cancer

OBJECTIVE

alpha-Tocopherol is a potent antioxidant that protects cell membranes against oxidative damage. Red blood cell alpha-tocopherol levels reflect membrane alpha-tocopherol concentrations, and altered levels may suggest membrane damage. The objective of this study was to determine the levels of alpha-tocopherol and alpha-tocopheryl quinone, the oxidized product of alpha-tocopherol, in plasma and red blood cells that were obtained from control subjects and patients with cervical intraepithelial neoplasia and cervical cancer.

STUDY DESIGN

In this cross-sectional study, 72 women, (32 African American and 40 Hispanic) were recruited. Among these subjects, 37 women had cervical intraepithelial neoplasia; 14 women had cervical cancer, and 21 women were considered control subjects, who had normal Papanicolaou test results. alpha-Tocopherol and alpha-tocopheryl quinone levels were determined in red blood cell and plasma by high-pressure liquid chromatography.

RESULTS

Plasma levels of alpha-tocopherol and alpha-tocopheryl quinone were decreased significantly (P=.012 and=.005, respectively, by Kruskal-Wallis test) in study groups compared with the control group; red blood cell levels of alpha-tocopherol and alpha-tocopheryl quinone were not altered significantly.

CONCLUSION

The lower alpha-tocopherol level that was observed in this study is consistent with our previous reports of decreased antioxidant concentrations and increased oxidative stress in women with cervical intraepithelial neoplasia. Unaltered red blood cell alpha-tocopherol and alpha-tocopheryl quinone levels suggest undamaged cell membrane. Further studies are needed to investigate the potential role of oxidative stress in cervical intraepithelial neoplasia.

Vitamin C in human health and disease is still a mystery? An overview

Ascorbic acid is one of the important water soluble vitamins. It is essential for collagen, carnitine and neurotransmitters biosynthesis. Most plants and animals synthesize ascorbic acid for their own requirement. However, apes and humans can not synthesize ascorbic acid due to lack of an enzyme gulonolactone oxidase. Hence, ascorbic acid has to be supplemented mainly through fruits, vegetables and tablets. The current US recommended daily allowance (RDA) for ascorbic acid ranges between 100-120 mg/per day for adults. Many health benefits have been attributed to ascorbic acid such as antioxidant, anti-atherogenic, anti-carcinogenic, immunomodulator and prevents cold etc. However, lately the health benefits of ascorbic acid has been the subject of debate and controversies viz., Danger of mega doses of ascorbic acid? Does ascorbic acid act as a antioxidant or pro-oxidant? Does ascorbic acid cause cancer or may interfere with cancer therapy? However, the Panel on dietary antioxidants and related compounds stated that the in vivo data do not clearly show a relationship between excess ascorbic acid intake and kidney stone formation, pro-oxidant effects, excess iron absorption. A number of clinical and epidemiological studies on anti-carcinogenic effects of ascorbic acid in humans did not show any conclusive beneficial effects on various types of cancer except gastric cancer. Recently, a few derivatives of ascorbic acid were tested on cancer cells, among them ascorbic acid esters showed promising anticancer activity compared to ascorbic acid. Ascorbyl stearate was found to inhibit proliferation of human cancer cells by interfering with cell cycle progression, induced apoptosis by modulation of signal transduction pathways. However, more mechanistic and human in vivo studies are needed to understand and elucidate the molecular mechanism underlying the anti-carcinogenic property of ascorbic acid. Thus, though ascorbic acid was discovered in 17th century, the exact role of this vitamin/nutraceutical in human biology and health is still a mystery in view of many beneficial claims and controversies.

Folate intake assessment: validation of a new approach

OBJECTIVE

To describe the performance characteristics and validate a folate-specific focused recall approach to estimating folate intake.

DESIGN

In a cross-sectional study, folate-specific recalls were used to estimate subjects' average daily folate intake from seven days of dietary recall over a one-month period. This estimate was compared to an estimate of the average daily folate intake obtained using the Fred Hutchinson Cancer Research Center Food Frequency Questionnaire (FFQ) and to plasma folate and homocysteine concentrations.

SUBJECTS

Subjects were women aged 21 to 47 years and were recruited from the university community. Thirty-three subjects were recruited, and 28 subjects completed the study.

INTERVENTION

After an initial clinic visit, during which a baseline blood sample was collected for measurement of plasma folate and total homocysteine concentrations, subjects participated in focused dietary recall interviews by telephone and/or Internet (e-mail). At the end of the month, subjects completed the FFQ. Main outcome measures The main outcome measures were to describe how well the focused recalls were able to describe relative dietary folate intake as compared to the FFQ and if the focused recall method estimate correlated with plasma folate and homocysteine concentrations. Statistical analyses Estimated folate intakes were ranked by tertiles using the two dietary assessment approaches and the rankings were compared. The Spearman correlation test was used to compare the focused recall and the FFQ dietary data to plasma folate and homocysteine concentrations.

RESULTS

Estimated folate intake inclusive of supplements was 411.4+/-192.8 (mean+/-SD) microg/day based on focused recalls and 458.5+/-221.5 microg/day based on the FFQ. Exclusive of supplements, estimated folate intake from the diet was 327.8+/-30.2 microg/day based on focused recalls and 373.5+/-155.6 microg/day based on the FFQ. The ranking comparison of focused recalls vs the FFQ demonstrated a concordance of 44% without supplements and 67% with supplements for the highest tertile, and 56% without supplements and 67% with supplements for the lowest tertile. Estimated folate intake based on focused recalls was correlated significantly with plasma homocysteine (r=-0.443, P<.02) and was marginally significantly correlated with plasma folate (r=0.354; P=.06) concentrations.

APPLICATIONS

A focused dietary recall approach is a useful method for collecting information on folate intake in women. Estimated folate intake based on the focused recall approach is reasonably correlated with plasma folate and total homocysteine concentrations even in this small sample of women. Accurate data on folate intake can form the basis of dietary counseling to increase intake of this important micronutrient in the target population of young women.

Iron withdrawal strategies fail to prevent the growth of SiHa-induced tumors in mice

OBJECTIVE

Cervical carcinoma is a human papillomavirus (HPV)-associated cancer for which treatment options still mainly rely on surgical procedures, with or without adjuvant radiotherapy and chemotherapy. We have previously shown that the chemically unrelated iron chelators desferrioxamine and deferiprone inhibit the growth and induce the apoptosis of HPV-positive cervical carcinoma cell lines, suggesting that iron chelators may represent a potential therapeutic approach for the treatment of cervical carcinoma. The present study was designed to investigate the effect of iron deprivation on the growth of human cervical carcinoma xenografts in athymic nude mice.

METHODS

Nude mice (nu/nu) of BALB/c background were treated with iron chelators [desferrioxamine (DFO), deferiprone (L1), or starch-DFO conjugate] or were fed with an iron-poor diet 6 weeks prior to subcutaneous injection of Si-Ha cells. These treatments were continued for 5 weeks after injection of the tumor cells. Treatment with the maximum tolerated doses of DFO, L1, or starch-DFO conjugate induced no significant iron deprivation in non-iron-overloaded mice, while an iron-poor diet led to a dramatic decrease in serum iron, transferrin iron saturation, and ferritin levels. However, neither iron chelators nor an iron-poor diet could significantly inhibit tumor growth.

CONCLUSION

Despite a potent antitumor effect in vitro, iron chelators fail to prevent the growth of cervical carcinoma xenografts in mice. On the basis of these results, clinical trials with iron chelators in patients with cervical carcinoma appear inappropriate.

Radical causes of cancer

Free radicals are ubiquitous in our body and are generated by normal physiological processes, including aerobic metabolism and inflammatory responses, to eliminate invading pathogenic microorganisms. Because free radicals can also inflict cellular damage, several defences have evolved both to protect our cells from radicals--such as antioxidant scavengers and enzymes--and to repair DNA damage. Understanding the association between chronic inflammation and cancer provides insights into the molecular mechanisms involved. In particular, we highlight the interaction between nitric oxide and p53 as a crucial pathway in inflammatory-mediated carcinogenesis.

Primary prevention of uterine cervix cancer: focus on vaccine history and current strategy

Primary prevention of uterine cervix cancer spans the gamut of human papillomavirus vaccine development, dietary adjustment, chemoprevention, and risk reduction. Lifestyle and social behaviors impact on risk for cervical cancer. Before examining the growing body of molecular evidence, animal studies, and phase I clinical trials that suggest that a virus-based vaccine for cervical cancer may soon become a reality, one must reflect on what has gone before in the vaccine-based battle with viral disease.

Antiproliferative and apoptotic effects of iron chelators on human cervical carcinoma cells

OBJECTIVE

Cervical carcinoma is a human papillomavirus (HPV)-associated cancer for which treatment options still mainly rely on surgical procedures, with or without adjuvant radiotherapy and chemotherapy. As iron may participate in the pathogenesis of viral infections and cancer in several ways, the present study was designed to investigate the effect of iron chelation on HPV-16- and HPV-18-positive cervical carcinoma cell lines.

METHODS

Desferrioxamine and deferiprone, two chemically unrelated iron chelators, were used to investigate the effect of iron chelation on SiHa and HeLa cells. Proliferation was investigated by cells counts, by [(3)H]thymidine uptake assay, and by immunostaining with Ki-67 and proliferating cell nuclear antigen (PCNA). Apoptosis was determined by morphological analysis, by a TUNEL assay, and by flow cytometry detecting FITC-conjugated annexin-V.

RESULTS

Desferrioxamine and deferiprone induced a time- and dose-dependent inhibition of SiHa and HeLa cell growth. The inhibition of cell growth was associated with a decrease in the expression of both stable and total PCNA and Ki-67, a proliferation marker whose expression may predict survival in uterine cervical carcinoma. TUNEL assay, flow cytometry with annexin-V-fluorescein, and morphological analysis indicated that iron chelation also induced a time- and dose-dependent apoptosis of both cell lines. This apoptotic effect was prevented by the addition of exogenous iron.

CONCLUSION

These results show that iron chelation inhibits the growth and induces the apoptosis of HPV-positive carcinoma cells. This suggests that iron chelators may represent a potential therapeutic approach for the management of cervical carcinoma.

Do antioxidants still have a role in the prevention of human cancer?

Antioxidants are components of diet that are involved in DNA and cell maintenance and repair. Dietary antioxidants include carotenoids, vitamin C, vitamin E, and selenium. Across a variety of cancers, the observational studies have inconsistent results with respect to the relationship shown of specific dietary intake or serum levels of antioxidants and risk of certain cancers. The results of the micronutrient supplement trials clearly do not support a reductionist approach to promoting regression of precancerous lesions or prevention of new cancer, except in a few cancers and specific populations. The ability of the antioxidant micronutrients to influence the risk for tissue injury and for cancer, mediated by their antioxidant activities, remains hypothetical.