Martha Yearsley

Black Raspberry-Derived Anthocyanins Demethylate Tumor Suppressor Genes Through the Inhibition of DNMT1 and DNMT3B in Colon Cancer Cells

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.

Immunohistochemistry staining for the mismatch repair proteins in the clinical care of patients with colorectal cancer

Purpose: The Ohio State University was one of the first medical centers to begin routinely performing immunohistochemical staining for the four mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) on all newly diagnosed patients with colorectal cancer. The results of implementing this testing on a clinical basis are critically assessed.Methods: From March 1, 2006, to March 31, 2008, 270 newly diagnosed colorectal cancer tumors received immunohistochemical staining for MLH1, MSH2, MSH6, and PMS2. If any stain was absent, the cancer genetic counselors were alerted, so that they could contact the patient. A follow-up genetic consultation was recommended for all patients with any stain absent other than MLH1 and to patients with absence of MLH1 ± PMS2 who were diagnosed younger than 60 years had a multiple Lynch syndrome-associated cancers or had a first-degree relative with colorectal cancer or endometrial cancer. Those attending the genetic consultation were offered appropriate follow-up testing.Results: There were 57 (21.1%) cases with abnormal immunohistochemical results. Genetics was able to contact 54 (94.7%) of these patients. It was determined that 34 (62.9%) of these 54 patients should be referred for a cancer genetics consultation, however, only nine (26.5%) made an appointment. Seven of the nine underwent additional testing, which was informative in five of the patients. Two (0.7%) new cases of Lynch syndrome were diagnosed and three patients were found to have proven/probable MLH1 promoter methylation.Conclusions: Routine immunohistochemical of the mismatch repair proteins on all newly diagnosed patients with colorectal cancer can be implemented clinically, however, patient uptake of follow-up genetic consultation is lower than expected.

Correlation of HIV-1 detection and histology in AIDS-associated emphysema.

HIV-seropositive individuals are at an increased risk for an accelerated form of emphysema. The purpose of this study was to determine the distribution of HIV-1 RNA in lung tissues and correlate this with the histologic findings and expression of matrix metalloproteases (MMPs). Reverse transcriptase (RT) in situ PCR analysis was performed on 11 AIDS lung autopsy specimens which showed varying degrees of emphysematous changes. In each lung, HIV-1 RNA was detected. In areas of histologically normal lung, very rare HIV-1-infected cells were evident. In contrast, many HIV-1-infected cells were noted in areas of emphysema. HIV-1 gag RNA was evident primarily in macrophages; infected pneumocytes were also seen. Similarly, MMP mRNA and protein, primarily MMP-9, localized to the areas of emphysema. Colabeling experiments documented that MMP expression was found primarily in cells that were HIV-1 negative and adjacent to HIV-1-infected macrophages. These results suggest that AIDS-related emphysema may be due, in part, to direct infection by HIV-1 of, primarily, alveolar macrophages, and concomitant up-regulation of MMP expression in the neighboring, noninfected cells.

Serous Cystadenoma of the Pancreas: Clinical and Pathological Features in 33 Patients

Aim: To report the clinicopathological features of patients with serous cystadenomas of the pancreas. Methods: Thirty-three cases of serous cystadenoma diagnosed between 1977 and 2006 were retrieved from the files of the Ohio State University Medical Center. Clinical data and microscopic slides were reviewed. Results: The patients included 27 women and 6 men with an age range of 38–83 (mean 64.3) years. The clinical presentation included 13 patients with abdominal pain and 8 patients with abdominal mass; 9 tumors were found incidentally. Abdominal CT scans in 25 patients were interpreted as suspicious for carcinoma in 8 (32%), suspicious for serous cystadenoma in 8, neoplasm not otherwise specified in 8, and suspicious for a pseudocyst in 1. Only 7 patients underwent a preoperative biopsy, and 5 of these were diagnosed as having a serous cystadenoma. All but 2 of the patients underwent surgical resection of the tumor. The serous cystadenomas varied in size from 1.0 to up to 13 cm in maximum dimension, and all but one had a multicystic appearance. Of the 33 serous cystadenomas, 20 (61%) were located in the pancreatic tail, 4 (12%) in the pancreatic body, 4 in the pancreatic body and tail, and 5 (15%) in the head of the pancreas. Follow-up in 17 patients (median 3 years, range from 1 month to 11 years) showed no recurrence of serous cystadenomas. One patient had von Hippel-Lindau syndrome, 4 patients had diabetes mellitus, 3 patients had metastatic cancer, and 2 patients had ovarian tumors. Conclusions: Serous cystadenoma is an uncommon neoplasm that can be confused with malignancy both clinically and radiologically; a correct diagnosis is important in order to provide an accurate prognosis.

Dietary black raspberries modulate DNA methylation in dextran sodium sulfate (DSS)-induced ulcerative colitis

UNLABELLED Ulcerative colitis (UC) is characterized by chronic inflammation of the colon. During inflammation, NF-κB is increased in colonic epithelial cells and in immune cells, leading to increases in proinflammatory cytokines. These events then increase DNA methyltransferases (DNMTs), which silence a subset of tumor suppressor genes by promoter methylation. Negative regulators of the Wnt pathway are frequently methylated in UC, leading to dysregulation of the pathway and, potentially, to colorectal cancer. We determined if black raspberries (BRBs) influence promoter methylation of suppressors in the Wnt pathway in dextran sodium sulfate (DSS)-induced UC. C57BL/6J mice received 1% DSS and were fed either control or 5% BRB diets. Mice were euthanized on days 7, 14 and 28, and their colons, spleen and bone marrow were collected. Berries reduced ulceration at day 28. This was accompanied by decreased staining of macrophages and neutrophils and decreased NF-κB p65 nuclear localization in the colon at all time points. At day 7, BRBs demethylated the promoter of dkk3, leading to its increased messenger RNA (mRNA) expression in colon, spleen and bone marrow. β-Catenin nuclear localization, c-Myc staining as well as protein expression of DNMT3B, histone deacetylases 1 and 2 (HDAC1 and HDAC2) and methyl-binding domain 2 (MBD2) were all decreased in colon; mRNA expression of these four proteins was decreased in bone marrow cells by BRBs. These results suggest that BRBs suppress colonic ulceration by correcting promoter hypermethylation of suppressor genes in the colon, as well as in the spleen and bone marrow that systematically regulate inflammation. SUMMARY Our results suggest that dietary BRBs suppress colonic ulceration by correcting promoter hypermethylation of suppressor genes in the colon, as well as in the spleen and bone marrow that systematically regulate inflammation in DSS-induced UC.

BRAF V600E Mutation Analysis Simplifies the Testing Algorithm for Lynch Syndrome

OBJECTIVES To evaluate our experience of adding reflex BRAF mutation analysis following mismatch repair (MMR) protein staining in the test algorithm for Lynch syndrome (LS), the most common inherited predisposition to colorectal cancer (CRC). METHODS Since January 1, 2009, BRAF V600E mutation analysis has been performed at our institution for all newly diagnosed CRCs with absent MLH1 and PMS2 proteins. RESULTS Ninety (22%) of 412 patients with CRC had at least 1 MMR absent (65 had MLH1 and PMS2 absent and 25 had other stain(s) absent). BRAF mutation was found in 36 (55%) of 65. Fifty-four (13%) of 412 patients required follow-up after addition of BRAF analysis compared with 90 who would have required follow-up without BRAF analysis. CONCLUSIONS The addition of reflex BRAF mutation testing in CRCs with absent MLH1 and PMS2 reduced the number of patient contacts by 40% and simplified the genetic testing for LS, leading to cost and time savings.

Black Raspberries Protectively Regulate Methylation of Wnt Pathway Genes in Precancerous Colon Tissue

Ulcerative colitis is frequently an intermediate step to colon cancer. The interleukin-10 knockout mouse is a genetic model of this progression. We report that knockout mice fed 5% black raspberries (BRB) had significantly less colonic ulceration as compared with knockout mice that consumed the control diet. Dysfunction of the Wnt signaling pathway is a key event in ulcerative colitis–associated colon carcinogenesis. Therefore, we investigated the effects of BRBs on the Wnt pathway and found that the BRB-fed knockout mice exhibited a significantly lower level of β-catenin nuclear translocation. We followed-up this observation by evaluating the effect of BRBs on selected Wnt pathway antagonists. The mRNA expression levels of wif1, sox17, and qki were diminished in the knockout mice, whereas they were expressed at normal levels in knockout mice that were fed BRBs. The lower mRNA expression of these genes in the colon from the knockout mice correlated with hypermethylation of their promoter regions; BRBs decreased their promoter methylation and increased mRNA expression of these genes. This hypomethylation was associated with elevated protein expression of key proteins/enzymes that augment methylation, for example, dnmt3b, hdac1, hdac2, and mbd2 in the knockout mice; in addition, BRBs decreased the protein expression of these proteins/enzymes. The knockout mouse model recapitulates what occurs in human ulcerative colitis. Promoter methylation of CDH1 and SFRP1 was significantly higher in human ulcerative colitis tissues compared with their adjacent normal tissues. In conclusion, our results suggest that BRBs inhibit colonic ulceration and, ultimately, colon cancer partly through inhibiting aberrant epigenetic events that dysregulate Wnt signaling. Cancer Prev Res; 6(12); 1317–27. ©2013 AACR.

EBV Kidney Allograft Infection: Possible Relationship with a Peri‐Graft Localization of PTLD

Post‐transplant lymphoproliferative disorder (PTLD) is a grave complication of transplantation and the result of uncontrolled proliferation of B lymphocytes infected with Epstein‐Barr virus (EBV). Herein we assess whether EBV infects renal grafts and whether there is a relationship between EBV kidney infection and PTLD. Allograft biopsies from 23 patients with PTLD were studied for the presence of EBV DNA and RNA (EBER‐1, ‐2) by in situ hybridization and for CD21 by immunohistochemistry. Results were compared to 43 transplants from people without PTLD. EBV DNA and RNA were detected in 11/43 patients without PTLD (26%), and in 15/23 (65%) patients with PTLD (p = 0.004). EBV DNA and RNA localized to proximal tubular cells and these cells showed up‐regulation of the EBV receptor CD21. EBV‐infected allografts were noted in 12/12 patients with PTLD located near the allograft and in 3/11 (27%) of patients with PTLD distant from the graft. Multiple biopsies in eight patients showed that graft EBV infection can precede the diagnosis of PTLD by as long as 42 months. It is concluded that EBV can infect kidney allografts, and there appears to be a relationship between this infection and the presence of PTLD near the graft.

A modified Lynch syndrome screening algorithm in colon cancer: BRAF immunohistochemistry is efficacious and cost beneficial.

OBJECTIVES Somatic BRAF mutation in colon cancer essentially excludes Lynch syndrome. We compared BRAF V600E immunohistochemistry (IHC) with BRAF mutation in core, biopsy, and whole-section slides to determine whether IHC is similar and to assess the cost-benefit of IHC. METHODS Resection cases (2009-2013) with absent MLH1 and PMS2 and prior BRAF mutation polymerase chain reaction results were chosen (n = 57). To mimic biopsy specimens, tissue microarrays (TMAs) were constructed. In addition, available biopsies performed prior to the resection were available in 15 cases. BRAF V600E IHC was performed and graded on TMAs, available biopsy specimens, and whole-section slides. Mutation status was compared with IHC, and cost-benefit analysis was performed. RESULTS BRAF V600E IHC was similar in TMAs, biopsy specimens, and whole-section slides, with only four (7%) showing discordance between IHC and mutation status. Using BRAF V600E IHC in our Lynch syndrome screening algorithm, we found a 10% cost savings compared with mutational analysis. CONCLUSIONS BRAF V600E IHC was concordant between TMAs, biopsy specimens, and whole-section slides, suggesting biopsy specimens are as useful as whole sections. IHC remained cost beneficial compared with mutational analysis, even though more patients needed additional molecular testing to exclude Lynch syndrome.

Nit1 and Fhit tumor suppressor activities are additive

The fragile histidine triad gene (human FHIT, mouse Fhit) has been shown to act as a tumor suppressor gene. Nit1 and Fhit form a fusion protein, encoded by the NitFhit gene in flies and worms, suggesting that mammalian Nit1 and Fhit proteins, which are encoded by genes on different chromosomes in mammals, may function in the same signal pathway(s). A previous study showed that Nit1 deficiency in knockout mice confers a cancer prone phenotype, as does Fhit deficiency. We have now assessed the tumor susceptibility of Fhit−/−Nit1−/− mice and observed that double knockout mice develop more spontaneous and carcinogen‐induced tumors than Fhit−/− mice, suggesting that the extent of tumor susceptibility due to Nit1 and Fhit deficiency is additive, and that Nit1 and Fhit affect distinct signal pathways in mammals. Nit1, like Fhit, is present in cytoplasm and mitochondria but not nuclei. Because Fhit deficiency affects responses to replicative and oxidative stress, we sought evidence for Nit1 function in response to such stresses in tissues and cultured cells: when treated with hydroxyurea, the normal kidney‐derived double‐deficient cells appear not to activate the pChk2 pathway and when treated with H2O2, show little evidence of DNA damage, compared with wild type and Fhit−/− cells. The relevance of Nit1 deficiency to human cancers was examined in human esophageal cancer tissues, and loss of Nit1 expression was observed in 48% of esophageal adenocarcinomas. J. Cell. Biochem. 107: 1097–1106, 2009.