Expression of p16INK4A in cervical precancerous lesions that is unlikely to be preventable by human papillomavirus vaccines.

BACKGROUND: Whether higher grade cervical intraepithelial neoplasia (CIN grade 2 or greater [CIN ≥ 2]) that develops because of human papillomavirus (HPV) genotypes not included in vaccines may progress to cervical cancer is largely unknown. The objectives of this study were to document expression of the cyclin-dependent kinase inhibitor 2A (p16) tumor-suppressor protein p16INK4A as a biomarker of cervical carcinogenesis or of malignant potential and to evaluate whether its expression differs between lesions associated with vaccine and nonvaccine high-risk (HR) human papillomavirus (HPV) genotypes. METHODS: The study population consisted of 371 women who had not received HPV vaccines. Women were categorized into vaccine and nonvaccine HR-HPV genotypes and lesions associated with those types. Logistic regression analyses were used to determine the association between positive expression p16INK4A and the risk of being diagnosed with CIN 2 or CIN 3. Differences in the proportion of CIN ≥2 lesions that were positive for p16INK4A expression by vaccine-related or nonvaccine-related HR-HPV genotype were determined using the Pearson chi-square test. RESULTS: Specimens that were positive for p16INK4A expression were 5.3 and 16.6 times more likely to be diagnosed as CIN 2 and CIN 3 lesions, respectively, compared to CIN 1 lesions. CIN ≥ 2 lesions that were negative for the bivalent and 9-valent HR-HPV genotypes had similar rates of positive p16INK4A expression compared with lesions that were positive for those HR-HPV genotypes. CONCLUSIONS: Lesions that may develop because of HR-HPV genotypes not included in HPV vaccines are likely to have similar malignant potential, suggesting that well developed screening programs combined with nonvaccine-based approaches may be needed to manage the residual risk of developing cervical cancer in the post-HPV vaccination era. Cancer 2016;122:3615-23. © 2016 American Cancer Society.

Accuracy of urinary human papillomavirus testing for the presence of cervical human papillomaviruses and higher grades of cervical intraepithelial neoplasia.

BACKGROUND: Although urine-based testing for human papillomavirus (HPV) is being explored as a practical approach for cervical cancer screening, whether the results differ by age, race, or indicators of excess body weight or in populations exposed to HPV vaccines has not been documented by previous studies. The purpose of this study was to determine the accuracy of urinary HPV testing for the presence of cervical HPVs and high-grade cervical intraepithelial lesions (grade 2 and 3 cervical intraepithelial neoplasia [CIN]) by the aforementioned population characteristics. METHODS: The study population consisted of 502 women diagnosed with different grades of CIN. HPV testing was performed with paired urine and cervical cell DNA with the Roche Diagnostics Linear Array test. Agreement coefficient 1 and probabilities were calculated to determine the accuracy of urinary HPV testing for the presence of cervical HPVs and CIN lesions. RESULTS: Substantial to almost perfect agreement (0.66-0.83) was observed in the detection of any HPV genotype in urine specimens versus cervical specimens, regardless of the population characteristics. Although the positive predictive value for the detection of CIN lesions was relatively low, the negative predictive value for CIN-3 was high (≥90%) among women positive for any of the urinary or cervical high-risk human papillomavirus (HR-HPV) genotypes or HPV genotypes not included in currently available HPV vaccines. CONCLUSIONS: The results demonstrate that urinary HPV testing provides highly satisfactory results for excluding the possibility of any cervical HPV infections, including HPV types not included in vaccines and CIN lesions associated with any HR-HPV, regardless of a woman's age, race, or excess body weight. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2836-2844. © 2016 American Cancer Society.

A lower degree of PBMC L1 methylation in women with lower folate status may explain the MTHFR C677T polymorphism associated higher risk of CIN in the US post folic acid fortification era.

BACKGROUND: Studies in populations unexposed to folic acid (FA) fortification have demonstrated that MTHFR C677T polymorphism is associated with increased risk of higher grades of cervical intraepithelial neoplasia (CIN 2+). However, it is unknown whether exposure to higher folate as a result of the FA fortification program has altered the association between MTHFR C677T and risk of CIN, or the mechanisms involved with such alterations. The current study investigated the following in a FA fortified population: 1) The association between MTHFR C677T polymorphism and risk of CIN 2+; 2) The modifying effects of plasma folate concentrations on this association; and 3) The modifying effects of plasma folate on the association between the polymorphism and degree of methylation of long interspersed nucleotide elements (L1s), in peripheral blood mononuclear cell (PBMC) DNA, a documented biomarker of CIN risk. METHODS: The study included 457 US women diagnosed with either CIN 2+ (cases) or ≤ CIN 1 (non-cases). Unconditional logistic regression models were used to test the associations after adjusting for relevant risk factors for CIN. RESULTS: The 677CT/TT MTHFR genotypes were not associated with the risk of CIN 2+. Women with CT/TT genotype with lower folate, however, were more likely to be diagnosed with CIN 2+ compared to women with CT/TT genotype with higher folate (OR = 2.41, P = 0.030). Women with CT/TT genotype with lower folate were less likely to have a higher degree of PBMC L1 methylation compared to women with CT/TT genotype with higher folate (OR = 0.28, P = 0.017). CONCLUSIONS: This study provides the first evidence that the MTHFR 677CT/TT genotype-associated lower degree of PBMC L1 methylation increases the risk of CIN 2+ in women in the US post-FA fortification era. Thus, even in the post-FA fortification era, not all women have adequate folate status to overcome MTHFR 677CT/TT genotype-associated lower degree of L1 methylation.

Folate and vitamin B12 may play a critical role in lowering the HPV 16 methylation-associated risk of developing higher grades of CIN.

We previously reported that a higher degree of methylation of CpG sites in the promoter (positions 31, 37, 43, 52, and 58) and enhancer site 7862 of human papillomavirus (HPV) 16 was associated with a lower likelihood of being diagnosed with HPV 16-associated CIN 2+. The purpose of this study was to replicate our previous findings and, in addition, to evaluate the influence of plasma concentrations of folate and vitamin B12 on the degree of HPV 16 methylation (HPV 16m). The study included 315 HPV 16-positive women diagnosed with either CIN 2+ or ≤CIN 1. Pyrosequencing technology was used to quantify the degree of HPV 16m. We reproduced the previously reported inverse association between HPV 16m and risk of being diagnosed with CIN 2+. In addition, we observed that women with higher plasma folate and HPV 16m or those with higher plasma vitamin B12 and HPV 16m were 75% (P < 0.01) and 60% (P = 0.02) less likely to be diagnosed with CIN 2+, respectively. With a tertile increase in the plasma folate or vitamin B12, there was a 50% (P = 0.03) and 40% (P = 0.07) increase in the odds of having a higher degree of HPV 16m, respectively. This study provides initial evidence that methyl donor micronutrients, folate and vitamin B12, may play an important role in maintaining a desirably high degree of methylation at specific CpG sites in the HPV E6 promoter and enhancer that are associated with the likelihood of being diagnosed with CIN 2+.

Age- and diet-specific effects of variation at S6 kinase on life history, metabolic, and immune response traits in Drosophila melanogaster.

Life history theory hypothesizes that genetically based variation in life history traits results from alleles that alter age-specific patterns of energy allocation among the competing demands of reproduction, storage, and maintenance. Despite the important role that alleles with age-specific effects must play in life history evolution, few naturally occurring alleles with age-specific effects on life history traits have been identified. A recent mapping study identified S6 kinase (S6k) as a candidate gene affecting lipid storage in Drosophila. S6k is in the target of rapamycin pathway, which regulates cell growth in response to nutrient availability and has also been implicated to influence many life history traits from fecundity to life span. In this article, we used quantitative complementation tests to examine the effect of allelic variation at S6k on a range of phenotypes associated with metabolism and fitness in an age-, diet-, and sex-specific manner. We found that alleles of S6k have pleiotropic effects on total protein levels, glycogen storage, life span, and the immune response and demonstrate that these allelic effects are age, diet, and sex specific. As many of the genes in the target of rapamycin pathway are evolutionarily conserved, our data suggest that genes in this pathway could play a pivotal role in life history evolution in a wide range of taxa.