IMPORTANCE Randomized clinical trials of vitamin D supplementation for secondary prevention in patients with cancer are needed, given positive results of observational studies. OBJECTIVE To determine whether postoperative vitamin D 3 supplementation can improve survival of patients with digestive tract cancers overall and in subgroups stratified by 25-hydroxyvitamin D (25[OH]D) levels. DESIGN, SETTING, AND PARTICIPANTS The AMATERASU trial, a randomized, double-blind, placebo-controlled trial conducted at a single university hospital in Japan. Enrollment began in January 2010 and follow-up was completed in February 2018. Patients aged 30 to 90 years with cancers of the digestive tract from the esophagus to the rectum, stages I to III, were recruited. Of 439 eligible patients, 15 declined and 7 were excluded after operation. INTERVENTIONS Patients were randomized to receive oral supplemental capsules of vitamin D (2000 IU/d; n = 251) or placebo (n = 166) from the first postoperative outpatient visit to until the end of the trial. MAIN OUTCOMES AND MEASURES The primary outcome was relapse-free survival time to relapse or death. The secondary outcome was overall survival time to death due to any cause. Subgroups analyzed had baseline serum 25(OH)D levels of 0 to less than 20 ng/mL, 20 to 40 ng/mL, and greater than 40 ng/mL; because of small sample size for the highest-baselinelevel group, interactions were tested only between the low-and middle-baseline-level groups. RESULTS All 417 randomized patients (mean age, 66 years; male, 66%; esophageal cancer, 10%; gastric cancer, 42%; colorectal cancer, 48%) were included in the analyses. There was 99.8% follow-up over a median 3.5 (interquartile range, 2.3-5.3) years, with maximal follow-up of 7.6 years. Relapse or death occurred in 50 patients (20%) randomized to vitamin D and 43 patients (26%) randomized to placebo. Death occurred in 37 (15%) in the vitamin D group and 25 (15%) in the placebo group. The 5-year relapse-free survival was 77% with vitamin D vs 69% with placebo (hazard ratio [HR] for relapse or death, 0.76; 95% CI, 0.50-1.14; P = .18). The 5-year overall survival in the vitamin D vs placebo groups was 82% vs 81% (HR for death, 0.95; 95% CI, 0.57-1.57; P = .83). In the subgroup of patients with baseline serum 25(OH)D levels between 20 and 40 ng/mL, the 5-year relapse-free survival was 85% with vitamin D vs 71% with placebo (HR for relapse or death, 0.46; 95% CI, 0.24-0.86; P = .02; P = .04 for interaction). Fractures occurred in 3 patients (1.3%) in the vitamin D group and 5 (3.4%) in the placebo group. Urinary stones occurred in 2 patients (0.9%) in the vitamin D group and 0 in the placebo group. CONCLUSIONS AND RELEVANCE Among patients with digestive tract cancer, vitamin D supplementation, compared with placebo, did not result in significant improvement in relapse-free survival at 5 years.

We identified IFI16 as a BRCA1-associated protein involved in p53-mediated apoptosis. IFI16 contains the Pyrin/PAAD/DAPIN domain, commonly found in cell death-associated proteins. BRCA1 (aa 502-802) interacted with the IFI16 Pyrin domain (aa 1-130). We found that IFI16 was localized in the nucleoplasm and nucleoli. Clear nucleolar IFI16 localization was not observed in HCC1937 BRCA1 mutant cells, but reintroduction of wild-type BRCA1 restored IFI16 nuclear relocalization following IR (ionizing radiation). Coexpression of IFI16 and BRCA1 enhanced DNA damage-induced apoptosis in mouse embryonic fibroblasts from BRCA1 mutant mice expressing wild-type p53, although mutant IFI16 deficient in binding to BRCA1 did not induce apoptosis. Furthermore, tetracycline-induced IFI16 collaborated in inducing apoptosis when adenovirus p53 was expressed in DNAdamaged p53-deficient EJ cells. These results indicate a BRCA1-IFI16 role in p53-mediated transmission of DNA damage signals and apoptosis.

. Phosphorylation of serines 1423 and -1524 was not induced in HCC1937 breast cancer cells, which contain mutant BRCA1 protein. Confocal microscopy revealed that unphosphorylated BRCA1 localizes on chromosomes from metaphase through telophase, whereas Ser-988-phosphorylated BRCA1 resides in the inner chromosomal structure, centrosome, and the cleavage furrow during prophase through telophase. We also found that Ser-988-phosphorylated BRCA1 relocalizes to the perinuclear region when cells are subjected to IR or UV radiation in the S phase. These results reinforce a model wherein phosphorylation of specific residues of BRCA1 after DNA damage affects its localization and function.Breast cancer tumor suppressor protein BRCA1 is a nuclear phosphoprotein with 1863 amino acids (1) that is implicated in the DNA repair pathway and regulation of gene transcription (2-7). In normally growing cells, BRCA1 is phosphorylated in a cell cycle-dependent manner; the protein undergoes hyperphosphorylation during the S phase and is dephosphorylated after the M phase (8, 9). Biochemical analysis has revealed that Ser-1497 is phosphorylated by cyclin-dependent kinase 2/cyclin A and E complexes (10). It has been also shown that DNA damage induces both nuclear redistribution of BRCA1 and an increased phosphorylation of the protein through DNA damage-activated kinases such as ATM, 1 ATR, and hCds1/Chk2(11-14). Several phosphorylation sites have been identified under these conditions, including Ser-988, -1423, -1387, and -1524. It has recently been shown that re-expression of wild type BRCA1 confers weak resistance to DNA damage-induced cell death in HCC1937 BRCA1 mutant breast cancer cell lines (12, 13, 15), whereas phosphorylation-defective BRCA1 alleles carrying Ser to Ala substitution of these residues did not rescue them from apoptosis. Furthermore, ionizing radiation (IR) treatment has been shown to induce phosphorylation of transcriptional corepressor CtIP, consequently releasing the protein from the BRCA1-containing complex leading to activation of transcriptional regulation of BRCA1 (16). These results provide a model of how DNA damage-induced phosphorylation of BRCA1 leads to transmission of signals that regulate gene expression. Previous studies have revealed that BRCA1 is involved in the G2-M checkpoint (17-19). Mouse embryonic fibroblasts carrying a targeted deletion of exon 11 of the BRCA1 gene showed a defective G2-M checkpoint accompanying unequal chromosome segregation, abnormal nuclear division, and aneuploidy. Interestingly, these phenotypes were also induced by overexpression of centrosome-associated Aurora-A/BTAK/ STK15 kinase, which is frequently amplified in breast cancer cells (20 -22). More recently, BRCA1 has been shown to localize in the mitotic centrosome, interacting with ␥-tublin (23, 24). Although these studies strongly suggest pivotal functions of BRCA1 in mitosis, physiological roles and regulation of BRCA1 phosphorylation in mitosis still require clarification.In the current study, we investigated how BR...