Circulating 25‐hydroxyvitamin D,vitamin D‐binding protein and risk of prostate cancer

We recently reported a significant positive association between 25‐hydroxyvitamin D [25(OH)D], the accepted biomarker of vitamin D status, and prostate cancer risk. To further elucidate this association, we examined the influence of vitamin D‐binding protein (DBP), the primary transporter of vitamin D compounds in the circulation. Prediagnostic serum concentrations of DBP were assayed for 950 cases and 964 matched controls with existing 25(OH)D measurements within the Alpha‐Tocopherol, Beta‐Carotene Cancer Prevention Study of Finnish men. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), and statistical tests were two sided. Serum DBP modified the association between serum 25(OH)D and prostate cancer, with higher risk for elevated 25(OH)D levels observed primarily among men having DBP concentrations above the median (OR = 1.81, 95% CI: 1.18–2.79 for highest vs. lowest quintile, p‐trend = 0.001) compared to those with DBP below the median (OR = 1.22, 95% CI: 0.81–1.84, p‐trend 0.97; p‐interaction = 0.04). Serum DBP was not associated with prostate cancer risk overall (OR = 0.96, 95% CI: 0.70–1.33 for highest vs. lowest quintile); however, high serum DBP was associated with significantly decreased risk of prostate cancer in men with lower (<median) 25(OH)D concentrations (OR = 0.59, 95% CI: 0.38–0.90 for highest vs. lowest quintile, p‐trend = 0.003) and increased risk in men with higher 25(OH)D concentrations (OR = 1.47, 95% CI: 0.98–2.20, p‐trend 0.10, p‐interaction = 0.02). Our data suggest that the primary vitamin D carrier protein, DBP, modulates the impact of vitamin D status on prostate cancer.     

A prospective investigation of serum 25‐hydroxyvitamin D and risk of lymphoid cancers

Studies indicate that higher sun exposure, especially in the recent past, is associated with reduced risk of non‐Hodgkin lymphoma (NHL). Ultraviolet radiation‐derived vitamin D may be protective against lymphomagenesis. We examined the relationship between prediagnostic serum 25‐hydroxyvitamin D (25(OH)D) and lymphoid cancer risk in a case–control study nested within the Alpha‐Tocopherol Beta‐Carotene Cancer Prevention Study cohort (1985–2002) of 29,133 Finnish male smokers (ages 50–69). We identified 270 incident lymphoid cancer cases and matched them individually with 538 controls by birth‐year and month of fasting blood draw at baseline. In conditional logistic regression models for 10 nmol/L increments or tertile comparisons, serum 25(OH)D was not associated with the risk of overall lymphoid cancers, NHL (n = 208) or multiple myeloma (n = 41). Odds ratios (OR) for NHL for higher tertiles were 0.75 (95% confidence interval (CI), 0.50, 1.14) and 0.82 (95% CI, 0.53, 1.26). The 25(OH)D‐NHL association, however, differed by follow‐up duration at diagnosis. Cases diagnosed less than 7 years from the baseline showed an inverse association (OR for highest vs. lowest tertile = 0.43; 95% CI: 0.23, 0.83; p for trend = 0.01), but not later diagnoses (OR = 1.52; 95% CI: 0.82, 2.80; p for trend = 0.17). The inverse association found for close exposure to diagnosis was not confounded by other risk factors for lymphoma or correlates of 25(OH)D. Although our findings suggest that circulating 25(OH)D is not likely associated with overall lymphoid cancer, they indicate a potentially protective effect on short‐term risk of NHL. © 2008 Wiley‐Liss, Inc.     

Hemoglobin adducts of benzene oxide in neonatal and adult dried blood spots

Adducts of reactive chemicals with hemoglobin (Hb) or human serum albumin can be used as biomarkers of internal doses of carcinogens. Because dried blood spots are easier to collect and store than conventional venous blood samples, they encourage applications of biomarkers of exposure in large epidemiologic studies. In addition, neonatal dried blood spot can be used to investigate chemical exposures in utero. Here, we report a simple method to isolate Hb from dried blood spot with high recovery and purity using the addition of ethanol to aqueous dried blood spot extracts. To prove the concept that dried blood spot-derived proteins can be used to assay for adducts, we measured Hb adducts of benzene oxide, a reactive metabolite of the ubiquitous air pollutant benzene in nine neonatal and nine adult dried blood spots (from volunteer subjects), using a gas chromatography-mass spectrometry method that we had previously developed. For comparison, benzene oxide-Hb adducts were measured in the same nine adult subjects using Hb that had been isolated and purified using our conventional method for venous blood. The geometric mean of benzene oxide-Hb levels in all dried blood spot samples ranged from 27.7 to 33.1 pmol/g globin. Neither of the comparisons of mean (logged) benzene oxide-Hb levels between sources (adult conventional versus adult dried blood spot and adult dried blood spot versus newborn dried blood spot) showed a significant difference. Based upon the estimated variance of the benzene oxide-Hb levels, we had 80% power to detect a 1.7-fold difference in geometric mean levels of benzene oxide-Hb in our sample of nine subjects.     

Meta‐analysis of observational studies of serum 25‐hydroxyvitamin D levels and colorectal,breast and prostate cancer and colorectal adenoma

Epidemiological studies have suggested a reduced risk of several cancers associated with high vitamin D status. We performed a systematic review with meta‐analyses of observational studies of serum 25‐hydroxyvitamin D level and colorectal, breast and prostate cancer and colonic adenoma. The literature of December 2009 was searched without language restriction. The meta‐regression analysis was done to compute dose‐response effects. Because in case‐control studies, serum 25‐hydroxyvitamin D level is measured after the diagnosis of cancer, separate analyses for case‐control and prospective studies were done. We identified 35 independent studies. The seven studies on colorectal adenomas were heterogeneous in terms of endpoint and control for major confounding factors, and we did not perform a meta‐analysis of these data. The summary relative risk (SRR) and (95% confidence interval) for a 10 ng/ml increase in serum 25‐hydroxyvitamin D was 0.85 (0.79; 0.91) for colorectal cancer (2,630 cases in 9 studies); 0.89 (0.81;0.98) for breast cancer (6,175 cases in 10 studies); and 0.99 (0.95;1.03) for prostate cancer (3,956 cases in 11 studies). For breast cancer, case‐control studies (3,030 cases) had major limitations and obtained SRR of 0.83 (0.79; 0.87) whereas SRR of prospective studies (3,145 cases) was 0.97 (0.92; 1.03). For colorectal and breast cancer, differences between cases and controls in the season of blood draw or in overweight/obesity or physical inactivity could not explain the results. In conclusion, a consistent inverse relationship between serum 25‐hydroxyvitamin D levels and colorectal cancer was found. No association was found for breast and prostate cancer.     

Assessing the causal association between 25‐hydroxyvitamin D and the risk of oral and oropharyngeal cancer using Mendelian randomization

Circulating 25‐hydroxyvitamin D (25OHD) is an appealing potential intervention for cancer risk and has been associated with oral and oropharyngeal cancer risk but evidence is inconsistent. The availability of genetic variants, uncorrelated with known confounders, but predictive of 25OHD and genetic data in a large oral and oropharyngeal cancer collaboration aids causal inference when assessing this association. A total of 5,133 oral and oropharyngeal cancer cases and 5,984 controls with genetic data were included in the study. Participants were based in Europe, North America and South America and were part of the Genetic Associations and Mechanisms in Oncology (GAME‐ON) Network. Five genetic variants reliably associated with circulating 25OHD were used to create a relative genetic measure of 25OHD. In the absence of measured 25OHD, two‐sample Mendelian randomization using individual level outcome data were used to estimate causal odds ratios (OR) for cancer case status per standard deviation increase in log25OHD. Analyses were replicated in an independent population‐based cohort (UK Biobank). In the GAME‐ON study, there was little evidence of a causal association between circulating 25OHD and oral cancer (OR = 0.86 [0.68;1.09], p = 0.22), oropharyngeal cancer (OR = 1.28 [0.72;2.26], p = 0.40) or when sites were combined (OR = 1.01 [0.74;1.40], p = 0.93). Replication in UK Biobank and pooled estimates produced similar results. Our study suggests that a clinically relevant protective effect of 25OHD on oral and oropharyngeal cancer risk is unlikely and supplementation of the general population with 25OHD is unlikely to be beneficial in preventing these cancers.     

Detection of cotinine in newborn dried blood spots.

Maternal smoking while pregnant is a plausible risk factor for childhood cancers because many seem to initiate in utero and tobacco-specific carcinogens cross the placenta. Social desirability bias may affect maternal report of smoking in case-control studies and could explain inconsistently observed associations with offspring cancer. Detection of tobacco smoke biomarkers in dried blood spots (DBS), which are increasingly stored by newborn screening programs, may improve retrospective assessment of fetal tobacco exposure. As proof-of-principle, we examined cotinine in DBS of 20 infants enrolled in a pilot study of pregnancy among low-income women. We recruited 107 pregnant women (<30 weeks of gestation) from six Women, Infants, and Children clinics in Minneapolis and St. Paul in 1999. Blood samples obtained at enrollment were tested for total cotinine using gas chromatography/mass spectrometry. Women were then interviewed at 7 months of gestation to determine current smoking habits. DBS were obtained from the Minnesota Department of Health. We tested DBS from 10 infants whose mothers had detectable serum cotinine at baseline and 10 control infants whose mothers had none. One quarter of each DBS was assayed for cotinine using gas chromatography/mass spectrometry; levels were estimated assuming 50 muL blood per sample. Mean cotinine was 29 ng/mL (SD, 7.5), 45 ng/mL (SD, 9.7), and 9 ng/mL (SD, 7.4), respectively, among infants of all smokers, infants of four women who acknowledged smoking at 7 months of gestation, and infants of nonsmokers. These results suggest that DBS analysis may identify infants of women who smoke throughout pregnancy.     

Serum 25‐hydroxyvitamin D,vitamin D binding protein and risk of colorectal cancer in the Prostate,Lung, Colorectal and Ovarian Cancer Screening Trial

The potential role of vitamin D in cancer prevention has generated substantial interest, and laboratory experiments indicate several anti‐cancer properties for vitamin D compounds. Prospective studies of circulating 25‐hydroxyvitamin D [25(OH)D], the accepted biomarker of vitamin D status, suggest an inverse association with colorectal cancer risk, but with some inconsistencies. Furthermore, the direct or indirect impact of the key transport protein, vitamin D binding protein (DBP), has not been examined. We conducted a prospective study of serum 25(OH)D and DBP concentrations and colorectal cancer risk in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, based on 476 colorectal cancer cases and 476 controls, matched on age, sex, race and date of serum collection. All subjects underwent sigmoidoscopic screening at baseline and once during follow‐up. Conditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Circulating 25(OH)D was inversely associated with colorectal cancer (OR = 0.60, 95% CI 0.38–0.94 for highest versus lowest quintile, p trend 0.01). Adjusting for recognized colorectal cancer risk factors and accounting for seasonal vitamin D variation did not alter the findings. Neither circulating DBP nor the 25(OH)D:DBP molar ratio, a proxy for free circulating 25(OH)D, was associated with risk (OR = 0.82, 95% CI 0.54–1.26, and OR = 0.79, 95% CI 0.52–1.21, respectively), and DBP did not modify the 25(OH)D association. The current study eliminated confounding by colorectal cancer screening behavior, and supports an association between higher vitamin D status and substantially lower colorectal cancer risk, but does not indicate a direct or modifying role for DBP.     

Implication of 14‐3‐3ε and 14‐3‐3θ/τ in proteasome inhibition‐induced apoptosis of glioma cells

Proteasome inhibitors represent a novel class of anticancer agents that are used in the treatment of hematologic malignancies and various solid tumors. However, mechanisms underlying their anticancer actions were not fully understood. It has been reported that strong 14‐3‐3 protein expression is observed and associated with tumor genesis and progression of astrocytoma. In addition, global inhibition of 14‐3‐3 functions with a general 14‐3‐3 antagonist difopein induces apoptosis of human astrocytoma cells, validating 14‐3‐3 as a potential molecular target for anticancer therapeutic management. In the current study, for the first time we demonstrated that proteasome inhibitors downregulated 14‐3‐3ε and 14‐3‐3θ/τ in U87 and SF295 glioma cells. Overexpression of 14‐3‐3ε and 14‐3‐3θ/τ significantly suppressed apoptosis of human glioma cells induced by proteasome inhibitors. We also demonstrated that MG132 activated ASK1 and siASK1 compromised the MG132‐induced apoptosis of glioma cells. Furthermore, overexpression of 14‐3‐3ε and 14‐3‐3θ/τ markedly suppressed activation of ASK1. Collectively, the current study supported that proteasome inhibitors, at least in part, caused cytotoxicity of glioma cells via downregulation of 14‐3‐3ε and 14‐3‐3θ/τ and subsequent activation of ASK1. (Cancer Sci 2013; 104: 55–61)     

Determinants of serum 25 hydroxyvitamin D levels in a nationwide cohort of blacks and non-Hispanic whites

Objective  

To develop algorithms predicting serum 25 hydroxyvitamin D [s25(OH)D] for a large epidemiological study whose subjects come from large geographic areas, are racially diverse and have a wide range in age, skin types, and month of blood sample collection. This will allow a regression calibration approach to determine s25(OH)D levels replacing the more costly method of collection and analysis of blood samples.     

25‐Hydroxyvitamin D2/D3 levels and factors associated with systemic inflammation and melanoma survival in the Leeds Melanoma Cohort

Lower 25‐hydroxyvitamin D₂/D₃ levels at melanoma diagnosis are associated with thicker primaries and poorer survival. We postulated that this might relate to the deleterious effect of systemic inflammation as 25‐hydroxyvitamin D₂/D₃ levels are inversely associated with levels of C‐reactive protein. 2,182 participants in the Leeds Melanoma Cohort (median follow‐up 7.98 years) provided data on drug exposure, comorbidities and a serum 25‐hydroxyvitamin D₂/D₃ level at recruitment. Factors reported to modify systemic inflammation (low vitamin D levels, high body mass index, use of aspirin or nonsteroidal anti‐inflammatory drugs or smoking were tested as predictors of microscopic ulceration (in which primary tumors are inflamed) and melanoma‐specific survival (MSS). Ulceration was independently associated with lower 25‐hydroxyvitamin D₂/D₃ levels (odds ratio (OR) = 0.94 per 10 nmol/L, 95% CI 0.88–1.00, p = 0.05) and smoking at diagnosis (OR = 1.47, 95% CI 1.00–2.15, p = 0.04). In analyses adjusted for age and sex, a protective effect was seen of 25‐hydroxyvitamin D₂/D₃ levels at diagnosis on melanoma death (OR = 0.89 per 10 nmol/L, 95% CI 0.83–0.95, p < 0.001) and smoking increased the risk of death (OR = 1.13 per 10 years, 95% CI 1.05–1.22, p = 0.001). In multivariable analyses (adjusted for tumor thickness) the associations with death from melanoma were low 25‐hydroxyvitamin D₂/D₃ level at recruitment (<20 nmol/L vs. 20–60 nmol/L, hazard ratio (HR) = 1.52, 95% CI 0.97–2.40, p = 0.07) and smoking duration at diagnosis (HR = 1.11, 95% CI 1.03–1.20, p = 0.009). The study shows evidence that lower vitamin D levels and smoking are associated with ulceration of primary melanomas and poorer MSS. Further analyses are necessary to understand any biological mechanisms that underlie these findings.     

C‐reactive protein and interleukin‐6 responses for differentiating fungal and bacterial aetiology in late‐onset neonatal sepsis

Fungal infections are increasingly frequent causes of neonatal sepsis (NS). This study examined the predictive value of the combined evaluation of the C‐reactive protein (CRP) and interleukin‐6 (IL‐6) responses for differentiating fungal and bacterial aetiologies in patients with NS. From January to September 2007, neonates who were diagnosed with NS and had their CRP and IL‐6 levels measured were selected. Based on their blood culture results, the neonates were divided into two groups: group of fungal sepsis (FS) and group of bacterial sepsis (BS). FS included 14 Candida albicans and one non‐albicans Candida isolates and BS included five Klebsiella pneumoniae, three Pseudomonas aeruginosa, three Enterococcus faecalis, two coagulase‐negative Staphylococcus species, one Enterococcus faecium and one Acinetobacter species. Significant differences were observed in the CRP (FS vs. BS: 28.10 ± 11.03 vs. 11.39 ± 2.94 mg l^?1, P = 0.026) and IL‐6 (FS vs. BS: 38.60 ± 24.24 vs. 392.82 ± 102.46 ng l^?1, P = 0.000) levels between groups. The combined evaluation of the CRP and IL‐6 responses better predicted the causative micro‐organism in NS.     

Potentials of C‐C motif chemokine 2–C‐C chemokine receptor type 2 blockers including propagermanium as anticancer agents

Inflammation plays an essential role in the development and progression of most cancers. Chemokine C‐C motif chemokine 2 (CCL2) and its receptor C‐C chemokine receptor type 2 (CCR2) constitute a key signaling axis in inflammation that has recently attracted much interest on the basis of evidence showing its association with cancer progression. Propagermanium (3‐oxygermylpropionic acid polymer) is an organogermanium compound that is given for the treatment of hepatitis B in Japan and which inhibits the CCL2‐CCR2 signaling pathway. Herein, we review the importance of the CCL2‐CCR2 axis as a target in cancer treatment as shown by studies in mice and humans with pharmacological agents including propagermanium.     

Side population of pancreatic cancer cells predominates in TGF‐β‐mediated epithelial to mesenchymal transition and invasion

We report here side population (SP) cells, a cancer stem cell enriched fraction from pancreatic cancer cell line, have enormous superior potential of the epithelial to mesenchymal transition (EMT), invasion, and metastasis. In an isolated SP cell culture, the cells rapidly expressed and up‐regulated E‐cadherin, an epithelial phenotypic marker, and the cells formed tightly contacted cell cluster, which is a representative epithelial phenotypic appearance. When the SP cells were incubated in the presence of TGF‐β, SP cells changed their shape into mesenchymal‐like appearance including spindle shaped assembly. This alteration was associated with significant reduction of E‐cadherin expression level. TGF‐β induced EMT‐associated gene alteration such as reduction of E‐cadherin mRNA and induction of Snail mRNA and matrixmetalloproteinase (MMP)‐2 mRNA. Finally, SP cells exerted notable matrigel invasion activity in response to TGF‐β treatment, whereas MP cells did not respond to TGF‐β‐mediated invasion. In conclusion, these results suggest that SP cells from pancreatic cancer cell line possess superior potentials of phenotypic switch, i.e., EMT/MET, micro‐invasion, and in vivo metastasis, as compared to MP cells. Because micro‐invasion and metastasis are key mechanisms of cancer malignant potential, SP cells would be the attractive target for preventing cancer progression. © 2008 UICC