bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Loss of Inhibitory Insulin Receptor Substrate-1 Phosphorylation Is an Early Event in Mammalian Target of Rapamycin–Dependent Endometrial Hyperplasia and Carcinoma
Authors: McCampbell Adrienne S. , Harris Heather A. , Crabtree Judy S. , Winneker Richard C. , Walker Cheryl L. , Broaddus Russell R.
Published: March 2024

Abstract
Insulin-like growth factor-I receptor signaling contributes to the development of endometrial hyperplasia, the precursor to endometrioid-type endometrial carcinoma, in humans and in rodent models. This pathway is under both positive and negative regulation, including S6 kinase (S6K) phosphorylation of insulin receptor substrate-1 (IRS-1) at S636/639, which occurs downstream of mammalian target of rapamycin (mTOR) activation to inhibit this adapter protein. We observed activation of mTOR with a high frequency in human endometrial hyperplasia and carcinoma, but an absence of IRS-1 phosphorylation, despite high levels of activated S6K. To explore when during disease progression mammalian target of rapamycin (mTOR) activation and loss of negative feedback to IRS-1 occurred, we used the Eker rat (Tsc2Ek/+) model, where endometrial hyperplasia develops as a result of loss of Tsc2, a “gatekeeper” for mTOR. We observed mTOR activation early in progression in hyperplasias and in some histologically normal epithelial cells, suggesting that event(s) in addition to loss of Tsc2 were required for progression to hyperplasia. In contrast, whereas IRS-1 S636/639 phosphorylation was observed in normal epithelium, it was absent from all hyperplasias, indicating loss of IRS-1 inhibition by S6K occurred during progression to hyperplasia. Treatment with a mTOR inhibitor (WAY-129327) significantly decreased hyperplasia incidence and proliferative indices. Because progression from normal epithelium to carcinoma proceeds through endometrial hyperplasia, these data suggest a progression sequence where activation of mTOR is followed by loss of negative feedback to IRS-1 during the initial stages of development of this disease. Cancer Prev Res; 3(3); 290–300
Data from Metformin Suppresses Colorectal Aberrant Crypt Foci in a Short-term Clinical Trial
Authors: Hosono Kunihiro , Endo Hiroki , Takahashi Hirokazu , Sugiyama Michiko , Sakai Eiji , Uchiyama Takashi , Suzuki Kaori , Iida Hiroshi , Sakamoto Yasunari , Yoneda Kyoko , Koide Tomoko , Tokoro Chikako , Abe Yasunobu , Inamori Masahiko , Nakagama Hitoshi , Nakajima Atsushi
Published: March 2024

Abstract
The biguanide metformin is widely used for treating diabetes mellitus. We previously showed the chemopreventive effect of metformin in two rodent models of colorectal carcinogenesis. However, besides epidemiologic studies, little is known about the effects of metformin on human colorectal carcinogenesis. The objective of this pilot study was to evaluate the chemopreventive effect of metformin on rectal aberrant crypt foci (ACF), which are an endoscopic surrogate marker of colorectal cancer. We prospectively randomized 26 nondiabetic patients with ACF to treatment with metformin (250 mg/d, n = 12) or no treatment (control, n = 14); 23 patients were evaluable for end point analyses (9 metformin and 14 control); the two groups were similar in ACF number and other baseline clinical characteristics. Magnifying colonoscopy determined the number of rectal ACF in each patient at baseline and after 1 month in a blinded fashion (as were all laboratory end point analyses). We also examined proliferative activity in colonic epithelium (via proliferating cell nuclear antigen labeling index) and apoptotic activity (via terminal deoxynucleotidyl transferase dUTP nick-end labeling). At 1 month, the metformin group had a significant decrease in the mean number of ACF per patient (8.78 ± 6.45 before treatment versus 5.11 ± 4.99 at 1 month, P = 0.007), whereas the mean ACF number did not change significantly in the control group (7.23 ± 6.65 versus 7.56 ± 6.75, P = 0.609). The proliferating cell nuclear antigen index was significantly decreased and the apoptotic cell index remained unaltered in normal rectal epithelium in metformin patients. This first reported trial of metformin for inhibiting colorectal carcinogenesis in humans provides preliminary evidence that metformin suppresses colonic epithelial proliferation and rectal ACF formation in humans, suggesting its promise for the chemoprevention of colorectal cancer. Cancer Prev Res; 3(9); 1077–83. ©2010 AACR.
Data from Epigenetic Differences in Normal Colon Mucosa of Cancer Patients Suggest Altered Dietary Metabolic Pathways
Authors: Silviera Matthew L. , Smith Brian P. , Powell Jasmine , Sapienza Carmen
Published: March 2024

Abstract
We have compared DNA methylation in normal colon mucosa between patients with colon cancer and patients without cancer. We identified significant differences in methylation between the two groups at 114 to 874 genes. The majority of the differences are in pathways involved in the metabolism of carbohydrates, lipids, and amino acids. We also compared transcript levels of genes in the insulin signaling pathway. We found that the mucosa of patients with cancer had significantly higher transcript levels of several hormones regulating glucose metabolism and significantly lower transcript levels of a glycolytic enzyme and a key regulator of glucose and lipid homeostasis. These differences suggest that the normal colon mucosa of patients with cancer metabolizes dietary components differently than the colon mucosa of controls. Because the differences identified are present in morphologically normal tissue, they may be diagnostic of colon cancer and/or prognostic of colon cancer susceptibility. Cancer Prev Res; 5(3); 374–84. ©2012 AACR.
Data from Blood Cell Origin of Circulating MicroRNAs: A Cautionary Note for Cancer Biomarker Studies
Authors: Pritchard Colin C. , Kroh Evan , Wood Brent , Arroyo Jason D. , Dougherty Katy J. , Miyaji Melanie M. , Tait Jonathan F. , Tewari Muneesh
Published: March 2024

Abstract
Circulating, cell-free microRNAs (miRNAs) hold great promise as a new class of cancer biomarkers due to their surprisingly high stability in plasma, association with disease states, and ease of sensitive measurement. Yet little is known about the origin of circulating miRNAs in either healthy or sick people or what factors influence levels of circulating miRNA biomarkers. Of 79 solid tumor circulating miRNA biomarkers reported in the literature, we found that 58% (46 of 79) are highly expressed in one or more blood cell type. Plasma levels of miRNA biomarkers expressed by myeloid (e.g., miR-223, miR-197, miR-574-3p, and let-7a) and lymphoid (e.g., miR-150) blood cells tightly correlated with corresponding white blood cell counts. Plasma miRNA biomarkers expressed by red blood cells (e.g., miR-486-5p, miR-451, miR-92a, and miR-16) could not be correlated to red cell counts due to limited variation in hematocrit in the cohort studied but were significantly increased in hemolyzed specimens (20- to 30-fold plasma increase; P < 0.0000001). Finally, in a patient undergoing autologous hematopoietic cell transplantation, plasma levels of myeloid- and lymphoid-expressed miRNAs (miR-223 and miR-150, respectively) tracked closely with changes in corresponding blood counts. We present evidence that blood cells are a major contributor to circulating miRNA and that perturbations in blood cell counts and hemolysis can alter plasma miRNA biomarker levels by up to 50-fold. Given that a majority of reported circulating miRNA cancer biomarkers are highly expressed in blood cells, we suggest caution in interpretation of such results as they may reflect a blood cell-based phenomenon rather than a cancer-specific origin. Cancer Prev Res; 5(3); 492–7. ©2011 AACR.
Data from Vaccine against MUC1 Antigen Expressed in Inflammatory Bowel Disease and Cancer Lessens Colonic Inflammation and Prevents Progression to Colitis-Associated Colon Cancer
Authors: Beatty Pamela L. , Narayanan Sowmya , Gariépy Jean , Ranganathan Sarangarajan , Finn Olivera J.
Published: March 2024

Abstract
Association of chronic inflammation with an increased risk of cancer is well established, but the contributions of innate versus adaptive immunity are not fully delineated. There has furthermore been little consideration of the role played by chronic inflammation–associated antigens, including cancer antigens, and the possibility of using them as vaccines to lower the cancer risk. We studied the human tumor antigen MUC1 which is abnormally expressed in colon cancers and also in inflammatory bowel disease (IBD) that gives rise to colitis-associated colon cancer (CACC). Using our new mouse model of MUC1+ IBD that progresses to CACC, interleukin-10 knockout mice crossed with MUC1 transgenic mice, we show that vaccination against MUC1 delays IBD and prevents progression to CACC. One mechanism is the induction of MUC1-specific adaptive immunity (anti-MUC1 IgG and anti-MUC1 CTL), which seems to eliminate abnormal MUC1+ cells in IBD colons. The other mechanism is the change in the local and the systemic microenvironments. Compared with IBD in vaccinated mice, IBD in control mice is dominated by larger numbers of neutrophils in the colon and myeloid-derived suppressor cells in the spleen, which can compromise adaptive immunity and facilitate tumor growth. This suggests that the tumor-promoting microenvironment of chronic inflammation can be converted to a tumor-inhibiting environment by increasing adaptive immunity against a disease-associated antigen. Cancer Prev Res; 3(4); 438–46. ©2010 AACR.
Data from Roles of Keap1–Nrf2 System in Upper Aerodigestive Tract Carcinogenesis
Authors: Ohkoshi Akira , Suzuki Takafumi , Ono Masao , Kobayashi Toshimitsu , Yamamoto Masayuki
Published: March 2024

Abstract
Cancers in the upper aerodigestive tract, including cancers of the tongue and the esophagus, are the third leading cause of cancer-related deaths in the world, and oxidative stress is well recognized as one of the major risk factors for carcinogenesis. The Keap1–Nrf2 system plays a critical role in cellular defense against oxidative stress, but little is known about its association with upper aerodigestive tract carcinogenesis. In this study, we examined whether loss of Nrf2-function exacerbates carcinogenesis by using an experimental carcinogenesis model that is induced by 4-nitroquinoline-1-oxide (4NQO). We found that Nrf2-knockout (Nrf2-KO) mice were more susceptible to 4NQO-induced tongue and esophageal carcinogenesis than wild-type mice, which suggests that Nrf2 is important for cancer prevention. We also examined how the suppression of Keap1 function or the induction of Nrf2 activity affected 4NQO carcinogenesis. Keap1-knockdown (Keap1-KD) mice were resistant to 4NQO-induced tongue and esophageal carcinogenesis. Importantly, no growth advantage was observed in tongue tumors in the Keap1-KD mice. These results show that the Keap1–Nrf2 system regulates an important defense mechanism against upper aerodigestive tract carcinogenesis. In addition to several important functions of Nrf2 that lead to cancer chemoprevention, we hypothesize that a mechanical defense of thickened keratin layers may also be a chemopreventive factor because thickened, stratified, squamous epithelium was found on the tongue of Keap1-KD mice. Cancer Prev Res; 6(2); 149–59. ©2012 AACR.
Data from Aspirin and Low-Dose Nitric Oxide–Donating Aspirin Increase Life Span in a Lynch Syndrome Mouse Model
Authors: Mcilhatton Michael A. , Tyler Jessica , Kerepesi Laura A. , Bocker-Edmonston Tina , Kucherlapati Melanie H. , Edelmann Winfried , Kucherlapati Raju , Kopelovich Levy , Fishel Richard
Published: March 2024

Abstract
Nonsteroidal anti–inflammatory drugs (NSAID) appear to be effective cancer chemopreventives. Previous cellular studies showed that aspirin (acetylsalicylic acid: ASA) and nitric oxide–donating ASA (NO-ASA) suppressed microsatellite instability (MSI) in mismatch repair (MMR)-deficient cells linked to the common cancer predisposition syndrome hereditary nonpolyposis colorectal cancer or Lynch syndrome (LS/HNPCC), at doses 300- to 3,000-fold less than ASA. Using a mouse model that develops MMR-deficient intestinal tumors that appear pathologically identical to LS/HNPCC, we show that ASA (400 mg/kg) and low-dose NO-ASA (72 mg/kg) increased life span by 18% to 21%. We also note a trend where ASA treatment resulted in intestinal tumors with reduced high MSI (H-MSI) and increased low MSI (L-MSI) as defined by the Bethesda Criteria. Low-dose NO-ASA had a minimal effect on MSI status. In contrast to previous studies, high-dose NO-ASA (720/1,500 mg/kg) treatments increased tumor burden, decreased life span, and exacerbated MSI uniquely in the LS/HNPCC mouse model. These results suggest that MMR-deficient tissues/mice may be specifically sensitive to intrinsic pharmacokinetic features of this drug. It is likely that long-term treatment with ASA may represent a chemopreventive option for LS/HNPCC patients. Moreover, as low-dose NO-ASA shows equivalent life span increase at 10-fold lower doses than ASA, it may have the potential to significantly reduce the gastropathy associated with long-term ASA treatment. Cancer Prev Res; 4(5); 684–93. ©2011 AACR.
Data from Preventing Cancer with Vaccines: Progress in the Global Control of Cancer
Authors: Kane Mark A.
Published: March 2024

Abstract
The cancer control community is largely unaware of great advances in the control of major human cancers with vaccines, including the dramatic control of hepatocellular (liver) cancer with hepatitis B virus (HBV) vaccine, now used routinely in more than 90% of countries. The biotechnology revolution has given us a new generation of highly effective vaccines against major global killers, global funding for immunization is orders of magnitude higher than ever before, and the vaccine delivery infrastructure has improved very significantly even in the poorest countries. Liver cancer is the greatest cause of cancer deaths in men of sub-Saharan Africa and much of Asia. Even in highly endemic countries such as China, the prevalence of HB surface antigen carriers has fallen from 10% to 1%–2% in immunized cohorts of children, and liver cancer has already fallen dramatically in Taiwanese children. The Global Alliance for Vaccines and Immunization (now called the GAVI Alliance) has greatly expedited this success by providing HBV vaccine free for five years in most of the world's 72 poorest countries. HBV vaccination can serve as a model for the global control of human papillomavirus (HPV)–related cervical and other cancers with HPV vaccines. Cervical cancer is the greatest cause of cancer death in women in many developing countries; HPV vaccines are highly effective in preventing HPV infection and precancerous lesions in women, and the quadrivalent vaccine also prevents genital warts in men and women and precancerous anal lesions in men. HPV is causing a growing proportion of oropharyngeal cancers, and HPV-related noncervical cancers (penile, anal, and oropharyngeal) may exceed the incidence of cervical cancer within a decade in industrial countries, where cervical screening is effective, causing reevaluation of male HPV immunization. In developing countries, few women are screened for cervical precancerous lesions, making immunization even more important. Currently, 26 primarily industrial countries routinely immunize girls with HPV vaccine, and GAVI will begin to accept applications in 2012 to fund vaccine in developing countries that can deliver the vaccine and if GAVI can negotiate an acceptable price (one manufacturer has already offered a price of $5 per dose). Cancer Prev Res; 5(1); 24–29. ©2012 AACR.
Data from Metabolic Syndrome and Risks of Colon and Rectal Cancer: The European Prospective Investigation into Cancer and Nutrition Study
Authors: Aleksandrova Krasimira , Boeing Heiner , Jenab Mazda , Bas Bueno-de-Mesquita H. , Jansen Eugene , van Duijnhoven Fränzel J.B. , Fedirko Veronika , Rinaldi Sabina , Romieu Isabelle , Riboli Elio , Romaguera Dora , Overvad Kim , Østergaard Jane Nautrup , Olsen Anja , Tjønneland Anne , Boutron-Ruault Marie-Christine , Clavel-Chapelon Françoise , Morois Sophie , Masala Giovanna , Agnoli Claudia , Panico Salvatore , Tumino Rosario , Vineis Paolo , Kaaks Rudolf , Lukanova Annekatrin , Trichopoulou Antonia , Naska Androniki , Bamia Christina , Peeters Petra H. , Rodríguez Laudina , Buckland Genevieve , Sánchez María-José , Dorronsoro Miren , Huerta Jose-María , Barricarte Aurelio , Hallmans Göran , Palmqvist Richard , Khaw Kay-Tee , Wareham Nicholas , Allen Naomi E. , Tsilidis Konstantinos K , Pischon Tobias
Published: March 2024

Abstract
Metabolic syndrome (MetS) is purportedly related to risk of developing colorectal cancer; however, the association of MetS, as defined according to recent international criteria, and colorectal cancer has not been yet evaluated. In particular, it remains unclear to what extent the MetS components individually account for such an association. We addressed these issues in a nested case–control study that included 1,093 incident cases matched (1:1) to controls by using incidence density sampling. Conditional logistic regression was used to estimate relative risks (RR) and 95% CIs. MetS was defined according to the criteria of the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATPIII), the International Diabetes Federation (IDF), and the 2009 harmonized definition. Among individual components, abdominal obesity (RR = 1.51; 95% CI: 1.16–1.96) was associated with colon cancer, whereas abnormal glucose metabolism was associated with both colon (RR = 2.05; 95% CI: 1.57–2.68) and rectal cancer (RR = 2.07; 95% CI: 1.45–2.96). MetS, as defined by each of the definitions, was similarly associated with colon cancer (e.g., RR = 1.91; 95% CI: 1.47–2.42 for MetS by NCEP/ATPIII), whereas MetS by NCEP/ATPIII, but not IDF or harmonized definition, was associated with rectal cancer (RR = 1.45; 95% CI: 1.02–2.06). Overall, these associations were stronger in women than in men. However, the association between MetS and colorectal

cancer was accounted for by abdominal obesity and abnormal glucose metabolism such that MetS did not provide risk information beyond these components (likelihood ratio test P = 0.10 for MetS by NCEP/ATPIII). These data suggest that simple assessment of abnormal glucose metabolism and/or abdominal obesity to identify individuals at colorectal cancer risk may have higher clinical utility than applying more complex MetS definitions. Cancer Prev Res; 4(11); 1873–83. ©2011 AACR.
Data from Phase IIa Clinical Trial of Curcumin for the Prevention of Colorectal Neoplasia
Authors: Carroll Robert E. , Benya Richard V. , Turgeon Danielle Kim , Vareed Shaiju , Neuman Malloree , Rodriguez Luz , Kakarala Madhuri , Carpenter Philip M. , McLaren Christine , Meyskens Frank L. , Brenner Dean E.
Published: March 2024

Abstract
Curcumin is derived from the spice tumeric and has antiinflammatory and antineoplastic effects in vitro and in animal models, including preventing aberrant crypt foci (ACF) and adenomas in murine models of colorectal carcinogenesis. Inhibiting the production of the procarcinogenic eicosanoids prostaglandin E2 (PGE2) and 5-hydroxyeicosatetraenoic acid (5-HETE) can suppress carcinogenesis in rodents. Curcumin reduces mucosal concentrations of PGE2 (via inhibition of cyclooxygenases 1 and 2) and 5-HETE (via inhibition of 5-lipoxygenase) in rats. Although preclinical data support curcumin activity in many sites, the poor bioavailability reported for this agent supports its use in the colorectum. We assessed the effects of oral curcumin (2 g or 4 g per day for 30 days) on PGE2 within ACF (primary endpoint), 5-HETE, ACF number, and proliferation in a nonrandomized, open-label clinical trial in 44 eligible smokers with eight or more ACF on screening colonoscopy. We assessed pre- and posttreatment concentrations of PGE2 and 5-HETE by liquid chromatography tandem mass spectroscopy in ACF and normal-tissue biopsies; ACF number via rectal endoscopy; proliferation by Ki-67 immunohistochemistry; and curcumin concentrations by high-performance liquid chromatography in serum and rectal mucosal samples. Forty-one subjects completed the study. Neither dose of curcumin reduced PGE2 or 5-HETE within ACF or normal mucosa or reduced Ki-67 in normal mucosa. A significant 40% reduction in ACF number occurred with the 4-g dose (P < 0.005), whereas ACF were not reduced in the 2-g group. The ACF reduction in the 4-g group was associated with a significant, five-fold increase in posttreatment plasma curcumin/conjugate levels (versus pretreatment; P = 0.009). Curcumin was well tolerated at both 2 g and 4 g. Our data suggest that curcumin can decrease ACF number, and this is potentially mediated by curcumin conjugates delivered systemically. Cancer Prev Res; 4(3); 354–64. ©2011 AACR.
Data from Omega-3 and Omega-6 Fatty Acids in Blood and Breast Tissue of High-Risk Women and Association with Atypical Cytomorphology
Authors: Hidaka Brandon H. , Li Shengqi , Harvey Katherine E. , Carlson Susan E. , Sullivan Debra K. , Kimler Bruce F. , Zalles Carola M. , Fabian Carol J.
Published: March 2024

Abstract
The ratio of omega-3 to omega-6 fatty acids, especially the long-chain eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) to arachidonic acid (AA) ratio, is inversely associated with breast cancer risk. We measured the association between cytologic atypia, a biomarker for short-term risk of breast cancer development, and omega-3 and omega-6 fatty acid intake and levels in blood and breast tissue. Blood and benign breast tissue, sampled by random periareolar fine-needle aspiration (RPFNA), was obtained from 70 women at elevated risk for breast cancer. Self-reported dietary intake was assessed by the NCI's Food Frequency Questionnaire. The fatty acid composition of five lipid compartments, red blood cell, plasma and breast phospholipids, and plasma and breast triaclyglycerides (TAG), was analyzed by gas chromatography as weight percent. Median daily intakes of EPA+DHA and total omega-3 fatty acids were 80 mg and 1.1 g, respectively. The median total omega-3:6 intake ratio was 1:10. Compared with women without atypia, those with cytologic atypia had lower total omega-3 fatty acids in red blood cell and plasma phospholipids and lower omega-3:6 ratios in plasma TAGs and breast TAGs (P < 0.05). The EPA+DHA:AA ratio in plasma TAGs was also lower among women with atypia. This is the first report of associations between tissue levels of omega-3 and omega-6 fatty acids and a reversible tissue biomarker of breast cancer risk. RPFNA cytomorphology could serve as a surrogate endpoint for breast cancer prevention trials of omega-3 fatty acid supplementation. Cancer Prev Res; 8(5); 359–64. ©2015 AACR.
Data from Metformin Prevents the Development of Oral Squamous Cell Carcinomas from Carcinogen-Induced Premalignant Lesions
Authors: Vitale-Cross Lynn , Molinolo Alfredo A. , Martin Daniel , Younis Rania H. , Maruyama Takashi , Patel Vyomesh , Chen Wanjun , Schneider Abraham , Gutkind J. Silvio
Published: March 2024

Abstract
Head and neck squamous cell carcinoma (HNSCC) is a major public health concern. The recent identification of the mTOR complex 1 (mTORC1) signaling pathway as a highly prevalent molecular signature underlying HNSCC pathogenesis has provided the foundation to search for novel therapeutic approaches to prevent and treat HNSCC. Here, we asked whether metformin, the most widely used medication for the treatment of type II diabetes, which acts in part by stimulating the AMP-activated protein kinase (AMPK) signaling pathway thereby reducing mTORC1 activity, may lower the risk of HNSCC development. Indeed, we show that metformin reduces the growth of HNSCC cells and diminishes their mTORC1 activity by both AMPK-dependent and -independent mechanisms. We also optimized an oral-specific carcinogenesis mouse model that results in the accumulation of multiple oral premalignant lesions at the end of the carcinogen exposure, some of which then spontaneously progress into HNSCC. Using this mouse model, we observed that metformin specifically inhibits mTORC1 in the basal proliferating epithelial layer of oral premalignant lesions. Remarkably, metformin prevented the development of HNSCC by reducing significantly the size and number of carcinogen-induced oral tumoral lesions and by preventing their spontaneous conversion to squamous cell carcinomas. Collectively, our data underscore the potential clinical benefits of using metformin as a targeted chemopreventive agent in the control of HNSCC development and progression. Cancer Prev Res; 5(4); 562–73. ©2012 AACR.
Data from Metformin and Hepatic Carcinogenesis
Authors: Pollak Michael , Gonzalez-Angulo Ana M.
Published: March 2024

Abstract
Retrospective, hypothesis-generating population studies suggest that diabetics treated with metformin have a substantially reduced risk of several cancers, including hepatoma, relative to diabetics on other therapies. In this issue of the journal (beginning on page 544), Bhalla and colleagues contribute to the growing literature on metformin effects in experimental carcinogenesis models, showing reduced carcinogen-induced hepatoma in mice. The clinical need to develop novel prevention strategies for hepatoma is obvious, given an increasing prevalence and poor prognosis. The clues that metformin or related biguanides may have utility in this area justify accelerated laboratory research, as more data concerning mechanism, pharmacokinetics, and predictors of efficacy will help to optimize the design of clinical trials. Cancer Prev Res; 5(4); 500–2. ©2012 AACR.
Data from Global Reactivation of Epigenetically Silenced Genes in Prostate Cancer
Authors: Ibragimova Ilsiya , Ibáñez de Cáceres Inmaculada , Hoffman Amanda M. , Potapova Anna , Dulaimi Essel , Al-Saleem Tahseen , Hudes Gary R. , Ochs Michael F. , Cairns Paul
Published: March 2024

Abstract
Transcriptional silencing associated with aberrant promoter hypermethylation is a common mechanism of inactivation of tumor suppressor genes in cancer cells. To globally profile the genes silenced by hypermethylation in prostate cancer, we screened a whole genome expression microarray for genes reactivated in the LNCaP, DU-145, PC-3, and MDA2b prostate tumor cell lines after treatment with the demethylating drug 5-aza-2-deoxycytidine and the histone deacetylation–inhibiting drug trichostatin A. A total of 2,997 genes showed at least 2-fold upregulation of expression after drug treatment in at least one prostate tumor cell line. For validation, we examined the first 45 genes, ranked by upregulation of expression, which had a typical CpG island and were known to be expressed in the normal cell counterpart. Two important findings were, first, that several genes known to be frequently hypermethylated in prostate cancer were apparent, and, second, that validation studies revealed eight novel genes hypermethylated in the prostate tumor cell lines, four of which were unmethylated in normal prostate cells and hypermethylated in primary prostate tumors (SLC15A3, 66%; KRT7, 54%; TACSTD2, 17%; GADD45b, 3%). Thus, we established the utility of our screen for genes hypermethylated in prostate cancer cells. One of the novel genes was TACSTD2/TROP2, a marker of human prostate basal cells with stem cell characteristics. TACSTD2 was unmethylated in prostatic intraepithelial neoplasia and may have utility in emerging methylation-based prostate cancer tests. Further study of the hypermethylome will provide insight into the biology of the disease and facilitate translational studies in prostate cancer. Cancer Prev Res; 3(9); 1084–92. ©2010 AACR.
Data from Rapamycin and mTORC1 Inhibition in the Mouse: Skin Cancer Prevention
Authors: Athar Mohammad , Kopelovich Levy
Published: March 2024

Abstract
Therapeutic and preventive effects of rapamycin include reduced risk of nonmelanoma skin cancer (NMSC). In this issue of the journal (beginning on page 1011), Checkley and colleagues report that rapamycin inhibits mTOR complex 1 in murine epidermis, thereby inhibiting tumor promotion mediated by tetradecanoyl phorbol-13 acetate in association with a strong anti-inflammatory effect. Rapamycin is an immunosuppressive drug for preventing graft rejection in organ transplant recipients and reduces the risk of NMSC and Kaposi's sarcoma in this population, albeit by mechanisms distinct from immunosuppression. Important future directions include identifying molecular predictors of rapamycin/rapalog sensitivity or resistance (potentially, for example, PI3K pathway alterations and KRAS mutations) and combined non-rapalog, mTOR-targeting approaches, all of which should increase efficacy and minimize toxicity. Cancer Prev Res; 4(7); 957–61. ©2011 AACR.
Data from Phase 0 Clinical Chemoprevention Trial of the Akt Inhibitor SR13668
Authors: Reid Joel M. , Walden Chad A. , Qin Rui , Ziegler Katie L. Allen , Haslam John L. , Rajewski Roger A. , Warndahl Roger , Fitting Cindy L. , Boring Daniel , Szabo Eva , Crowell James , Perloff Marjorie , Jong Ling , Bauer Brent A. , Mandrekar Sumithra J. , Ames Matthew M. , Limburg Paul J.
Published: March 2024

Abstract
SR13668, an orally active Akt pathway inhibitor, has demonstrated cancer chemopreventive potential in preclinical studies. To accelerate the clinical development of this promising agent, we designed and conducted the first-ever phase 0 chemoprevention trial to evaluate and compare the effects of food and formulation on SR13668 bioavailability. Healthy adult volunteers were randomly assigned to receive a single, 38-mg oral dose of SR13668 in one of five different formulations, with or without food. On the basis of existing animal data, SR13668 in a PEG400/Labrasol oral solution was defined as the reference formulation. Blood samples were obtained pre- and post-agent administration for pharmacokinetic analyses. Area under the plasma concentration–time curve (AUC0–∞) was defined as the primary endpoint. Data were analyzed and compared using established statistical methods for phase 0 trials with a limited sample size. Participants (n = 20) were rapidly accrued over a 5-month period. Complete pharmacokinetic data were available for 18 randomized participants. AUC0–∞ values were highest in the fed state (range = 122–439 ng/mL × hours) and were statistically significantly different across formulations (P = 0.007), with Solutol HS15 providing the highest bioavailability. SR13668 time to peak plasma concentration (3 hours; range, 2–6 hours) and half-life were (11.2 ± 3.1 hours) were not formulation-dependent. Using a novel, highly efficient study design, we rapidly identified a lead formulation of SR13668 for further clinical testing. Our findings support application of the phase 0 trial paradigm to accelerate chemoprevention agent development. Cancer Prev Res; 4(3); 347–53. ©2011 AACR.
Data from Folate Deficiency Induces Dysfunctional Long and Short Telomeres; Both States Are Associated with Hypomethylation and DNA Damage in Human WIL2-NS Cells
Authors: Bull Caroline F. , Mayrhofer Graham , O'Callaghan Nathan J. , Au Amy Y. , Pickett Hilda A. , Low Grace Kah Mun , Zeegers Dimphy , Hande M. Prakash , Fenech Michael F.
Published: March 2024

Abstract
The essential role of dietary micronutrients for genome stability is well documented, yet the effect of folate deficiency or excess on telomeres is not known. Accordingly, human WIL2-NS cells were maintained in medium containing 30, 300, or 3,000 nmol/L folic acid (FA) for 42 days to test the hypothesis that chronic folate deficiency would cause telomere shortening and dysfunction. After 14 days, telomere length (TL) in FA-deficient (30 nmol/L) cultures was 26% longer than that of 3,000 nmol/L FA cultures; however, this was followed by rapid telomere attrition over the subsequent 28 days (P trend, P < 0.0001); both long and short telomere status was positively correlated with biomarkers of chromosome instability (P ≤ 0.003) and mitotic dysfunction (P = 0.01), measured by the cytokinesis-block micronucleus cytome (CBMN-cyt) assay. The early increase in TL was associated with FA-deficiency–induced global DNA hypomethylation (P = 0.05), with an effect size similar to that induced by the DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine. Quantitative PCR analysis indicated a negative association between FA concentration and uracil incorporation into telomeric DNA (r = −0.47, P = 0.1), suggesting a possible plausible mechanism for uracil as a cause of folate deficiency–induced telomere dysfunction or deletion. Peptide nucleic acid-FISH (PNA-FISH) analysis showed that FA deficiency resulted in 60% of micronuclei containing acentric terminal fragments, an observation consistent with the 3-fold increase in terminal deletions (P = 0.0001). Together, these results demonstrate the impact of folate deficiency on biomarkers of telomere maintenance and integrity, and provide evidence that dysfunctional long telomeres may be as important as critically short telomeres as a cause of chromosomal instability. Cancer Prev Res; 7(1); 128–38. ©2013 AACR.
Data from Inositol Hexaphosphate Inhibits Tumor Growth, Vascularity, and Metabolism in TRAMP Mice: A Multiparametric Magnetic Resonance Study
Authors: Raina Komal , Ravichandran Kameswaran , Rajamanickam Subapriya , Huber Kendra M. , Serkova Natalie J. , Agarwal Rajesh
Published: March 2024

Abstract
Herein, employing anatomical and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), we evaluated noninvasively, the in vivo, chemopreventive efficacy of inositol hexaphosphate (IP6), a major constituent of high-fiber diets, against prostate tumor growth and progression in transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Male TRAMP mice, beginning at 4 weeks of age, were fed with 1%, 2%, or 4% (w/v) IP6 in drinking water or only drinking water till 28 weeks of age and monitored using MRI over the course of study. Longitudinal assessment of prostate volumes by conventional MRI and tumor vascularity by gadolinium-based DCE-MRI showed a profound reduction in tumor size, partly due to antiangiogenic effects by IP6 treatment. As potential mechanisms of IP6 efficacy, decrease in the expression of glucose transporter GLUT-4 protein together with an increase in levels of phospho-AMP-activated kinase (AMPKTh172) were observed in prostate tissues of mice from IP6 fed-groups, suggesting that IP6 is interfering with the metabolic events occurring in TRAMP prostate. Investigative metabolomics study using quantitative high-resolution 1H-NMR on prostate tissue extracts showed that IP6 significantly decreased glucose metabolism and membrane phospholipid synthesis, in addition to causing an increase in myoinositol levels in the prostate. Together, these findings show that oral IP6 supplement blocks growth and angiogenesis of prostate cancer in the TRAMP model in conjunction with metabolic events involved in tumor sustenance. This results in energy deprivation within the tumor, suggesting a practical and translational potential of IP6 treatment in suppressing growth and progression of prostate cancer in humans. Cancer Prev Res; 6(1); 40–50; ©2012 AACR.
Data from Cortactin and Focal Adhesion Kinase as Predictors of Cancer Risk in Patients with Laryngeal Premalignancy
Authors: Rodrigo Juan P. , Álvarez-Alija Gustavo , Menéndez Sofía Tirados , Mancebo Gonzalo , Allonca Eva , García-Carracedo Darío , Fresno Manuel Florentino , Suárez Carlos , García-Pedrero Juana María
Published: March 2024

Abstract
Novel markers are needed to accurately predict the risk of malignant transformation in laryngeal premalignancies. We therefore investigated the clinical significance of cortactin (CTTN) and focal adhesion kinase (FAK) during laryngeal tumorigenesis and their potential utility as cancer risk markers. CTTN and FAK protein expression and gene amplification were assessed in 82 patients with laryngeal dysplasia and correlated with clinicopathologic parameters and laryngeal cancer risk. Increased CTTN and FAK expression was found respectively in 41 (50%) and 40 (49%) of 82 laryngeal dysplasias; protein expression was maintained or further augmented in the corresponding patient-matched invasive tumors subsequently developed. CTTN and FAK/PTK2 gene amplifications were respectively detected in 10 (12%) and 26 (32%) laryngeal dysplasias. Both CTTN and FAK protein expression increased with the grade of dysplasia; however, CTTN and FAK expression but not histology correlated significantly with increased laryngeal cancer risk (P = 0.009 and P = 0.002, respectively). Patients carrying strong CTTN- or FAK-expressing dysplastic lesions experienced a significantly higher cancer incidence (P = 0.006 and P = 0.001, respectively; log-rank test). Furthermore, FAK expression was an independent predictor of laryngeal cancer development (HR = 3.706, 95% CI: 1.735–7.916; P = 0.001) and the combination of FAK and CTTN showed superior predictive value (HR = 5.042, 95% CI: 2.255–11.274; P < 0.001). Taken together, our findings support the involvement of CTTN and FAK in malignant transformation and provide original evidence for their potential clinical utility as biomarkers for the risk of developing laryngeal cancer. Cancer Prev Res; 4(8); 1333–41. ©2011 AACR.
Data from A Novel Prodrug of Epigallocatechin-3-gallate: Differential Epigenetic hTERT Repression in Human Breast Cancer Cells
Authors: Meeran Syed M. , Patel Shweta N. , Chan Tak-Hang , Tollefsbol Trygve O.
Published: March 2024

Abstract
Epigallocatechin-3-gallate (EGCG), a major component of green tea polyphenols (GTP), has been reported to downregulate telomerase activity in breast cancer cells thereby increasing cellular apoptosis and inhibiting cellular proliferation. However, the major concerns with GTPs are their bioavailability and stability under physiologic conditions. In the present study, we show that treatments with EGCG and a novel prodrug of EGCG (pro-EGCG or pEGCG) dose- and time-dependently inhibited the proliferation of human breast cancer MCF-7 and MDA-MB-231 cells but not normal control MCF10A cells. Furthermore, both EGCG and pro-EGCG inhibited the transcription of hTERT (human telomerase reverse transcriptase), the catalytic subunit of telomerase, through epigenetic mechanisms in estrogen receptor (ER)-positive MCF-7 and ER-negative MDA-MB-231 cells. The downregulation of hTERT expression was found to be because of hTERT promoter hypomethylation and histone deacetylations, mediated at least partially through inhibition of DNA methyltransferase and histone acetyltransferase activities, respectively. In addition, we also observed that EGCG and pEGCG can remodel chromatin structures of the hTERT promoter by decreasing the level of acetyl-H3, acetyl-H3K9, and acetyl-H4 to the hTERT promoter. EGCG and pEGCG induced chromatin alterations that facilitated the binding of many hTERT repressors such as MAD1 and E2F-1 to the hTERT regulatory region. Depletion of E2F-1 and MAD1 by using siRNA reversed the pEGCG downregulated hTERT expression and associated cellular apoptosis differently in ER-positive and ER-negative breast cancer cells. Collectively, our data provide new insights into breast cancer prevention through epigenetic modulation of telomerase by using pro-EGCG, a more stable form of EGCG, as a novel chemopreventive compound. Cancer Prev Res; 4(8); 1243–54. ©2011 AACR.
Data from Selective Antibody Response to Streptococcus gallolyticus Pilus Proteins in Colorectal Cancer Patients
Authors: Boleij Annemarie , Roelofs Rian , Danne Camille , Bellais Samuel , Dramsi Shaynoor , Kato Ikuko , Tjalsma Harold
Published: March 2024

Abstract
Streptococcus gallolyticus subsp. gallolyticus (previously called Streptococcus bovis biotype I) infections have long been associated with colorectal cancer (CRC). This work aimed to investigate the CRC-associated humoral immune response to four pilus proteins of this bacterium by newly developed ELISAs. Pilus proteins are interesting diagnostic targets as they are the building blocks of pilin-like structures that mediate bacterial virulence and are readily exposed to the host immune system upon infection. The presence of serum antibodies against these pilus proteins was evaluated in Dutch and American populations. These analyses showed that an immune response to these antigens was specific for clinical S. gallolyticus subsp. gallolyticus infections, but that increased serum antibody titers to multiple pilus proteins in single individuals were rarely observed. However, a multiplex approach based on antibody titers against any of these four antigens resulted in assay sensitivities between 16% and 43% for the detection of early-stage CRC. Together these findings underscore the potential of a multi-antigen approach to complement diagnosis of S. gallolyticus subsp. gallolyticus–associated CRC. Cancer Prev Res; 5(2); 260–5. ©2011 AACR.
Data from A Randomized Clinical Trial of the Effects of Supplemental Calcium and Vitamin D3 on the APC/β-Catenin Pathway in the Normal Mucosa of Colorectal Adenoma Patients
Authors: Ahearn Thomas U. , Shaukat Aasma , Flanders W. Dana , Rutherford Robin E. , Bostick Roberd M.
Published: March 2024

Abstract
APC/β-catenin pathway perturbation is a common early event in colorectal carcinogenesis and is affected by calcium and vitamin D in basic science studies. To assess the effects of calcium and vitamin D on adenomatous polyposis coli (APC), β-catenin, and E-cadherin expression in the normal appearing colorectal mucosa of sporadic colorectal adenoma patients, we conducted a randomized, double-blinded, placebo-controlled 2 × 2 factorial clinical trial. Pathology-confirmed colorectal adenoma cases were treated with 2 g/day elemental calcium and/or 800 IU/day vitamin D3 versus placebo over 6 months (N = 92; 23/group). Overall APC, β-catenin, and E-cadherin expression and distributions in colon crypts in normal-appearing rectal mucosa biopsies were detected by standardized automated immunohistochemistry and quantified by image analysis. In the vitamin D3-supplemented group relative to placebo, the proportion of APC in the upper 40% of crypts (Φh APC) increased 21% (P = 0.01), β-catenin decreased 12% (P = 0.18), E-cadherin increased 72% (P = 0.03), and the Φh APC/β-catenin ratio (APC/β-catenin score) increased 31% (P = 0.02). In the calcium-supplemented group Φh APC increased 10% (P = 0.12), β-catenin decreased 15% (P = 0.08), and the APC/β-catenin score increased 41% (P = 0.01). In the calcium/vitamin D3-supplemented group, β-catenin decreased 11% (P = 0.20), E-cadherin increased 51% (P = 0.08), and the APC/β-catenin score increased 16% (P = 0.26). These results support (i) that calcium and vitamin D modify APC, β-catenin, and E-cadherin expression in humans in directions hypothesized to reduce risk for colorectal neoplasms, (ii) calcium and vitamin D as potential chemopreventive agents against colorectal neoplasms, and (iii) the potential of APC, β-catenin, and E-cadherin expression as modifiable, preneoplastic risk biomarkers for colorectal neoplasms. Cancer Prev Res; 5(10); 1247–56. ©2012 AACR.
Data from STAT2 Contributes to Promotion of Colorectal and Skin Carcinogenesis
Authors: Gamero Ana M. , Young Matthew R. , Mentor-Marcel Roycelynn , Bobe Gerd , Scarzello Anthony J. , Wise Jennifer , Colburn Nancy H.
Published: March 2024

Abstract
Signal transducer and activator of transcription 2 (STAT2) is an essential transcription factor in the type I IFN (IFN-α/β) signal transduction pathway and known for its role in mediating antiviral immunity and cell growth inhibition. Unlike other members of the STAT family, IFNs are the only cytokines known to date that can activate STAT2. Given the inflammatory and antiproliferative dual nature of IFNs, we hypothesized that STAT2 prevents inflammation-induced colorectal and skin carcinogenesis by altering the inflammatory immune response. Contrary to our hypothesis, deletion of STAT2 inhibited azoxymethane/dextran sodium sulfate–induced colorectal carcinogenesis as measured by prolonged survival, lower adenoma incidence, smaller polyps, and less chronic inflammation. STAT2 deficiency also inhibited 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate–induced skin carcinogenesis as indicated by reduced papilloma multiplicity. A potential mechanism by which STAT2 promotes carcinogenesis is through activation of proinflammatory mediators. Deletion of STAT2 decreased azoxymethane/dextran sodium sulfate–induced expression and release of proinflammatory mediators, such as interleukin-6 and CCL2, and decreased interleukin-6 release from skin carcinoma cells, which then decreased STAT3 activation. Our findings identify STAT2 as a novel contributor to colorectal and skin carcinogenesis that may act to increase the gene expression and secretion of proinflammatory mediators, which in turn activate the oncogenic STAT3 signaling pathway. Cancer Prev Res; 3(4); 495–504. ©2010 AACR.
Data from Long-term Nicotine Replacement Therapy: Cancer Risk in Context
Authors: Shields Peter G.
Published: March 2024

Abstract
Nicotine replacement therapy (NRT) for up to 12 weeks is well established, safe and efficacious for fostering smoking cessation. Some smokers at a high risk of relapse may benefit from long-term use, and so long-term NRT safety and efficacy have become a paramount question for the FDA and others. Laboratory studies have indicated a carcinogenic potential of nicotine. Animal model studies reported in this issue of the journal by Maier and colleagues (beginning on page 1743) and Murphy and colleagues (beginning on page 1752), however, provide additional reassurance that NRT does not promote lung cancer. Very long-term studies of NRT effects do not yet exist and would be needed to definitively answer the question about NRT efficacy and cancer risk and some decision making will need to be made based on limited human data and experimental studies. The overall NRT safety question is complex and requires consideration of three contexts and comparator groups (long-term NRT/abstinence vs. smoking, long-term intermittent NRT/reduced smoking vs. smoking, and long-term NRT/abstinence vs. abstinence without long-term NRT). Although the data on these issues are insufficient, the first comparison seems intuitive and may be compelling enough to allow the FDA to approve a long-term indication for NRT. An important public health goal is to help smokers and their health care providers understand the implications of potential long-term NRT risks in the context of its potential benefits and the far greater risks of continued smoking. Cancer Prev Res; 4(11); 1719–23. ©2011 AACR.