Purpose: This study evaluated the effects of black raspberries (BRBs) on biomarkers of tumor development in the human colon and rectum including methylation of relevant tumor suppressor genes, cell proliferation, apoptosis, angiogenesis, and expression of Wnt pathway genes.Experimental Design: Biopsies of adjacent normal tissues and colorectal adenocarcinomas were taken from 20 patients before and after oral consumption of BRB powder (60 g/d) for 1-9 weeks. Methylation status of promoter regions of five tumor suppressor genes was quantified. Protein expression of DNA methyltransferase 1 (DNMT1) and genes associated with cell proliferation, apoptosis, angiogenesis, and Wnt signaling were measured.Results: The methylation of three Wnt inhibitors, SFRP2, SFRP5, and WIF1, upstream genes in Wnt pathway, and PAX6a, a developmental regulator, was modulated in a protective direction by BRBs in normal tissues and in colorectal tumors only in patients who received BRB treatment for an average of 4 weeks, but not in all 20 patients with 1-9 weeks of BRB treatment. This was associated with decreased expression of DNMT1. BRBs modulated expression of genes associated with Wnt pathway, proliferation, apoptosis, and angiogenesis in a protective direction.Conclusions: These data provide evidence of the ability of BRBs to demethylate tumor suppressor genes and to modulate other biomarkers of tumor development in the human colon and rectum. While demethylation of genes did not occur in colorectal tissues from all treated patients, the positive results with the secondary endpoints suggest that additional studies of BRBs for the prevention of colorectal cancer in humans now appear warranted.

Purpose-The present study compared the ability of different berry types to prevent chemicallyinduced tumorigenesis in the rat esophagus. We also determined if berries influence the levels of inflammatory cytokines in the serum of carcinogen-treated rats.Methods-Rats were treated with the carcinogen N-nitrosomethylbenzylamine (NMBA) for 5 weeks, then placed on diets containing 5% of either black or red raspberries, strawberries, blueberries, noni, açaí or wolfberry until the end of the study. The effects of the berries on tumor incidence, multiplicity and size were determined, as well as their effects on the levels of selected inflammatory cytokines in serum.Results-All berry types were about equally effective in inhibiting NMBA-induced tumorigenesis in the rat esophagus. They also reduced the levels of the serum cytokines, interleukin 5 (IL-5) and GRO/KC, the rat homologue for human interleukin-8 (IL-8), and this was associated with increased serum antioxidant capacity.Correspondence to: Gary D. Stoner, gary.stoner@osumc.edu. NIH Public Access Author ManuscriptPharm Res. Author manuscript; available in PMC 2011 January 6. Conclusions-Seven berry types were about equally capable of inhibiting tumor progression in the rat esophagus in spite of known differences in levels of anthocyanins and ellagitannins. Serum levels of IL-5 and GRO/KC (IL-8) may be predictive of the inhibitory effect of chemopreventive agents on rat esophageal carcinogenesis.

Familial adenomatous polyposis (FAP) is characterized by the early onset of colonic polyposis and a high risk for colorectal cancer. FAP is treated by colectomy followed by lifelong removal of rectal polyps. This study determined whether black raspberries (BRBs) might regress rectal polyps in patients with FAP. Fourteen patients with FAP were treated with BRBs daily for 9 months. Seven patients received BRB powder orally plus two BRB suppositories inserted into the rectum at bedtime. The other 7 received an oral placebo plus the suppositories. Rectal polyp counts and polyp sizes were obtained at time zero and after 9 months of BRB treatment. Polyps and adjacent normal tissue were collected at both time points. The burden (P ¼ 0.036) but not number (P ¼ 0.069) of rectal polyps was significantly decreased. No benefit was noted with the addition of oral BRBs. Three patients were nonresponders. BRBs significantly decreased cellular proliferation, DNA methylation methyl transferase 1 protein expression, and p16 promoter methylation, but not promoter methylation of the Wnt pathway antagonists, SFRP2 and WIF1, in rectal polyps (adenomas) from responders but not from nonresponders. The MBD-seq assay revealed more demethylated transcription start sites (TSS), including those for miRNAs, in BRB-treated adenomas from the responders. In conclusion, BRB suppositories seem sufficient for regressing rectal polyps in patients with FAP. Cancer Prev Res; 7(7); 666-74. Ó2014 AACR.

We previously reported that oral administration of black raspberry powder decreased promoter methylation of tumor suppressor genes in tumors from patients with colorectal cancer. The anthocyanins (ACs) in black raspberries are responsible, at least in part, for their cancer-inhibitory effects. In the present study, we asked if ACs are responsible for the demethylation effects observed in colorectal cancers. Three days of treatment of ACs at 0.5, 5, and 25 μg/ml suppressed activity and protein expression of DNMT1 and DNMT3B in HCT116, Caco2 and SW480 cells. Promoters of CDKN2A, and SFRP2, SFRP5, and WIF1, upstream of Wnt pathway, were demethylated by ACs. mRNA expression of some of these genes was increased. mRNA expression of β-catenin and c-Myc, downstream of Wnt pathway, and cell proliferation were decreased; apoptosis was increased. ACs were taken up into HCT116 cells and were differentially localized with DNMT1 and DNMT3B in the same cells visualized using confocal laser scanning microscopy. Although it was reported that DNMT3B is regulated by c-Myc in mouse lymphoma, DNMT3B did not bind with c-Myc in HCT116 cells. In conclusion, our results suggest that ACs are responsible, at least in part, for the demethylation effects of whole black raspberries in colorectal cancers.

The present study used a postinitiation protocol to investigate molecular mechanisms by which black raspberries (BRBs) influence the late stages of N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis in rats. F344 rats were injected with NMBA and then fed either control diet or a diet containing 5% BRB powder. Control rats were injected with DMSO/water (20:80), the vehicle for NMBA. Esophagi from control, NMBA- and NMBA + BRB-treated rats were collected at 35 wk for histopathological, molecular, and immunohistochemical analyses. Treatment with 5% BRBs reduced the number of dysplastic lesions and the number and size of esophageal papillomas in NMBA-treated rats. When compared to esophagi from control rats, NMBA treatment led to the differential expression of 4807 genes in preneoplastic esophagus (PE) and 17 846 genes in esophageal papillomas. Dietary BRBs modulated 626 of the 4807 differentially expressed genes in PE and 625 of the 17 846 differentially expressed genes in esophageal papillomas towards normal levels of expression. In both PE and in papillomas, BRBs modulated the mRNA expression of genes associated with carbohydrate and lipid metabolism, cell proliferation and death, and inflammation. In these same tissues, BRBs modulated the expression of proteins associated with proliferation, apoptosis, inflammation, angiogenesis, and both cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism. Interestingly, matrix metalloproteinases involved in tissue invasion and metastasis, and proteins associated with cell-cell adhesion, were also modulated by BRBs. This is the first report of the effects of berries on the expression of genes associated with the late stages of rat esophageal carcinogenesis.