Low vitamin D status is common globally and is associated with multiple disease outcomes. Understanding the correlates of vitamin D status will help guide clinical practice, research, and interpretation of studies. Correlates of circulating 25-hydroxyvitamin D (25(OH)D) concentrations measured in a single laboratory were examined in 4,723 cancer-free men and women from 10 cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers, which covers a worldwide geographic area. Demographic and lifestyle characteristics were examined in relation to 25(OH)D using stepwise linear regression and polytomous logistic regression. The prevalence of 25(OH)D concentrations less than 25 nmol/L ranged from 3% to 36% across cohorts, and the prevalence of 25(OH)D concentrations less than 50 nmol/L ranged from 29% to 82%. Seasonal differences in circulating 25(OH)D were most marked among whites from northern latitudes. Statistically significant positive correlates of 25(OH)D included male sex, summer blood draw, vigorous physical activity, vitamin D intake, fish intake, multivitamin use, and calcium supplement use. Significant inverse correlates were body mass index, winter and spring blood draw, history of diabetes, sedentary behavior, smoking, and black race/ethnicity. Correlates varied somewhat within season, race/ethnicity, and sex. These findings help identify persons at risk for low vitamin D status for both clinical and research purposes.

Bone metastasis from prostate cancer can occur years after prostatectomy, due to reactivation of dormant disseminated tumor cells (DTC) in the bone, yet the mechanism by which DTCs are initially induced into a dormant state in the bone remains to be elucidated. We show here that the bone microenvironment confers dormancy to C4-2B4 prostate cancer cells, as they become dormant when injected into mouse femurs but not under the skin. Live-cell imaging of dormant cells at the single-cell level revealed that conditioned medium from differentiated, but not undifferentiated, osteoblasts induced C4-2B4 cellular quiescence, suggesting that differentiated osteoblasts present locally around the tumor cells in the bone conferred dormancy to prostate cancer cells. Gene array analyses identified GDF10 and TGFβ2 among osteoblast-secreted proteins that induced quiescence of C4-2B4, C4-2b, and PC3-mm2, but not 22RV1 or BPH-1 cells, indicating prostate cancer tumor cells differ in their dormancy response. TGFβ2 and GDF10 induced dormancy through TGFβRIII to activate phospho-p38MAPK, which phosphorylates retinoblastoma (RB) at the novel N-terminal S249/T252 sites to block prostate cancer cell proliferation. Consistently, expression of dominant-negative p38MAPK in C4-2b and C4-2B4 prostate cancer cell lines abolished tumor cell dormancy both and Lower TGFβRIII expression in patients with prostate cancer correlated with increased metastatic potential and decreased survival rates. Together, our results identify a dormancy mechanism by which DTCs are induced into a dormant state through TGFβRIII-p38MAPK-pS249/pT252-RB signaling and offer a rationale for developing strategies to prevent prostate cancer recurrence in the bone. These findings provide mechanistic insights into the dormancy of metastatic prostate cancer in the bone and offer a rationale for developing strategies to prevent prostate cancer recurrence in the bone. .

A key issue in cancer therapy is how to enhance the tumor-targeting efficacy of chemotherapeutic agents. In this study, we developed a cooperative dual-targeted delivery platform for paclitaxel (PTX) that has potential application as a powerful prostate cancer treatment. The nanomedicine was prepared by first conjugating PTX to nontoxic high-magnetization nanocarriers which can be actively guided and targeted by an external magnet. Next, the surface was functionalized with carboxylated o-(2-aminoethyl)polyethyleneglycol (NH(2)-EPEG-COOH) to enable uptake by the reticuloendothelial system. Antiprostate-specific membrane antigen antibodies (APSMAs) were then conjugated onto the carrier to recognize the extracellular domain of the prostate-cancer specific membrane antigen (PSMA), thus binding to cancer cells as a secondary active targeting mechanism. We found a significant enhancement of PTX concentration at the tumor site by nearly 20-fold. In addition, the drug half-life was prolonged more than 4.1-fold (from 24 to 99 h) at 37 °C. Low-dose (4.5 mg/kg) injection of the dual-targeted therapeutic nanomedicine in the presence of magnetic targeting significantly prolonged the median survival of nude mice from 35 to 58 days compared to mice that received a high dose (6 mg/kg) of free PTX. This report demonstrates the potential utility of targeted nanomedicine in the clinical treatment of cancer.

Photothermal therapy (PTT) is a potential treatment for cancer that makes use of near-infrared (NIR) laser irradiation and is expected to assist traditional anti-cancer drug therapies; however, the therapeutic efficacy of PTT is restricted by thermal resistance due to the overexpression of heat shock proteins and insufficient penetration depth of lasers. Thus, PTT needs to be combined with additional therapeutic methods to obtain the optimal therapeutic efficacy for cancer. Herein, a multifunctional therapeutic platform combining PTT with glucose-triggered chemodynamic therapy (CDT) and glutathione (GSH)-triggered hypoxia relief was developed via GOx@MBSA-PPy-MnO2 NPs (GOx for glucose oxidase, M for Fe3O4, BSA for bovine serum albumin, and PPy for polypyrrole). GOx@MBSA-PPy-MnO2 NPs have excellent photothermal efficiency and can release Mn2+, which catalyzes the transformation of H2O2 into hydroxyl radicals (·OH) and O2 via a Fenton-like reaction, effectively destroying cancer cells and relieving tumor hypoxia. Meanwhile, a high content of H2O2 was produced via GOx catalysis of glucose, further enhancing the CDT efficiency. In addition, in vitro and in vivo experiments showed that the inhibition of cancer cell proliferation and effective inhibition of tumors could be caused by the combined PTT/glucose-triggered CDT effects and hypoxia relief of the GOx@MBSA-PPy-MnO2 NPs. Overall, this work provides evidence of a synergistic therapy that remarkably improves therapeutic efficacy and significantly prolongs the lifetime of mice compared with controls.