Carcinoma of the cervix and smoking

A niche for infectious disease in environmental health: rethinking the toxicological paradigm

OBJECTIVE

In this review we highlight the need to expand the scope of environmental health research, which now focuses largely on the study of toxicants, to incorporate infectious agents. We provide evidence that environmental health research would be strengthened through finding common ground with the tools and approaches of infectious disease research.

DATA SOURCES AND EXTRACTION

We conducted a literature review for examples of interactions between toxic agents and infectious diseases, as well as the role of these interactions as risk factors in classic "environmental" diseases. We investigated existing funding sources and research mandates in the United States from the National Science Foundation and the National Institutes of Health, particularly the National Institute of Environmental Health Sciences.

DATA SYNTHESIS

We adapted the toxicological paradigm to guide reintegration of infectious disease into environmental health research and to identify common ground between these two fields as well as opportunities for improving public health through interdisciplinary research.

CONCLUSIONS

Environmental health encompasses complex disease processes, many of which involve interactions among multiple risk factors, including toxicant exposures, pathogens, and susceptibility. Funding and program mandates for environmental health studies should be expanded to include pathogens in order to capture the true scope of these overlapping risks, thus creating more effective research investments with greater relevance to the complexity of real-world exposures and multifactorial health outcomes. We propose a new model that integrates the toxicology and infectious disease paradigms to facilitate improved collaboration and communication by providing a framework for interdisciplinary research. Pathogens should be part of environmental health research planning and funding allocation, as well as applications such as surveillance and policy development.

Elevated aromatase expression correlates with cervical carcinoma progression

OBJECTIVES

We have previously demonstrated that aromatase mRNA is induced in cervical carcinomas compared to normal tissue, suggesting that in situ aromatase expression leading to elevated local estrogen production may contribute to cervical carcinogensis. Our objectives are to examine 1) whether aromatase protein and activity are induced in cervical carcinomas, 2) aromatase expression correlates with disease stage, and 3) inflammatory cytokines (e.g., IL-6 and TNFalpha) may correlate with aromatase expression.

METHODS

RNA and protein were isolated from human cervical carcinomas and normal cervical biopsies to examine aromatase expression, using real-time RT-PCR, Western blot analysis, and immunohistochemistry. Aromatase activity in tissue was measured using the tritiated water release method. IL-6 and TNFalpha expression was also examined.

RESULTS

Aromatase protein and activity levels were increased in cervical carcinomas compared to normal tissue. RNA levels correlated significantly with disease progression, with highest aromatase expression detected in stage IV tumors (p<0.001, R(2)=0.77). Aromatase promoters 1.3 and 1.4 were elevated in cervical carcinomas and in cervical cancer cells. The expression of inflammatory cytokines IL-6 and TNFalpha, known to induce aromatase, significantly correlated with aromatase expression (R(2)>0.9). TNFalpha treatment induced aromatase expression in cervical cancer cells.

CONCLUSION

Increased aromatase protein and activity in cervical carcinomas and the correlation of its expression with disease stage implicates it in cervical carcinogenesis. The correlation of IL-6 and TNFalpha expression with aromatase suggests that these inflammatory cytokines may induce aromatase expression, which is confirmed by induction of aromatase expression due to TNFalpha treatment of cervical cancer cells.

Epidemiology of substance use disorders in women

Significant gender differences exist in the prevalence of substance use disorders in the United States. There is a trend among boys and girls aged 12 to 17 years toward comparable rates of use and initiation for alcohol, cocaine, heroin, and tobacco. If this trend continues, over time there may be a narrowing of the male-to-female prevalence ratios of substance abuse in the older age groups. This possibility is particularly disturbing because women have a heightened vulnerability to medical, physical, mental, and social consequences of substance use. Women also carry additional unique risks during pregnancy because of the effect on neonates. In addition, they have certain gender-specific cancer risks. Given this and the declining age of initiation of substance use in women, prevention and treatment efforts especially geared toward women (eg, education of all medical and paramedical staff, screening in primary care clinics, detection of drug use early in pregnancy or before conception, brief interventions and treatment programs that integrate women's needs) are exceedingly important to stop and ultimately reverse this growing trend.

HLA DQ-DR haplotype and susceptibility to cervical carcinoma: indications of increased risk for development of cervical carcinoma in individuals infected with HPV 18

The association of HLA class II DQB1 and DRB1 alleles with the development of cervical carcinoma was studied in 150 Swedish patients using PCR-based HPV and HLA typing. The association of cervical carcinoma with alleles encoding the DQ3 antigen, previously found among German and Norwegian patients, was not observed in the Swedish patients. Five DQ-DR haplotypes were indicated to be positively associated with development of cervical carcinoma in the Swedish patients. Two of these HLA associations were specific for HPV 18 infected patients, suggesting that the ability of the oncogenic HPV 18 to cause more rapid-transit tumors than other high risk HPV types may be due to a deficiency in antigen presentation by the HLA molecules encoded by carried on these haplotypes.

Simultaneous polymerase chain reaction detection and restriction typing for the diagnosis of human genital papillomavirus infection

A polymerase chain reaction method has been developed which allows the simultaneous detection of the majority of clinically relevant HPV types. Degenerate HPV-specific primers direct the one-step amplification of a DNA region spanning E1 and E7 genes. This enables an immediate distinction between the two groups of papillomaviruses, characterized by high or low oncogenic potential, simply from the size of amplified DNA. The PCR product can be subjected to a second round of amplification with internal primers, which are specific for 7 high-risk HPV types, HPV-16, -18, -31, -33, -35, -45 and -58. Precise identification of one-step or two-step amplified DNA is done by endonuclease digestion with one or two enzymes. The detection sensitivity, which has been assessed using cloned HPV genomes and HeLa and CaSki cell lines, varies from a few tens to a few hundreds of viral genome equivalents. The accuracy of the method has been confirmed by examining cervical scrapings of 44 patients.

Etiology of cervical cancer: current concepts

The data on the etiological factors presented here may enable us to suggest a synergism between the various factors associated with the pathogenesis of cervical cancer. Infection of the cervix by HPV 16/18 may result in persistence of viral DNA. The persistent HPV-DNA undergoes disruption at the E2 region, when integrated into the host genome. The transcriptional products E6 and E7 oncoproteins bind to and cause the degradation of p53 and Rb tumor-suppressor gene products. It is possible that, at that point, other cofactors may be involved in the progression toward a precancerous or cancerous condition. Those cofactors may include cigarette smoking, by introducing co-carcinogens to the tissue or by suppressing the local or systemic immune resistance similar to the effect of depressed immune resistance seen in AIDS or immunosuppression of transplant patients; hormones, by enhancing growth of HPV and transformation of HPV infected cells; low serum vitamin levels leading to decreased tissue resistance; or other infections causing local inflammation and the production of free radicals. CIN develops, leading eventually to cervical cancer.

Detection of human papillomavirus and human cytomegalovirus in cervical lesions by in situ hybridization using biotinylated probes

Infections with specific types of human papillomavirus (HPV) have emerged as necessary but not sufficient factors in the development of the majority of cervical cancers. The infection by human cytomegalovirus (HCMV) has also been implicated in both cervical intraepithelial neoplasia (CIN) and cancer. In order to test prevalence of these viral pathogens in genital lesions with suspect cytopathic changes after observation of smears, cervical biopsies from 131 patients were obtained under colposcopic guidance. The biopsies were tested for the presence of HPV and HCMV by the in situ hybridization technique using biotinylated DNA probes on paraffin-embedded sections. Presence of HCMV is twice more frequent in women with HPV-induced cervical lesions (40%) than in women with any detectable HPV (20%). It may be concluded that HCMV might contribute as one synergistic factor in the development of cervical dysplasia.