Cancer prevention research (Philadelphia, Pa.)最新文献

This study aimed to assess how ursolic acid (UA) can protect human skin keratinocytes from damage caused by ultraviolet B (UVB) radiation. Utilizing an omics-based approach, we characterized the features of photodamage and investigated the potential of UA to reverse HaCaT cell subpopulation injury caused by UVB radiation. The most significant changes in metabolite levels after UA treatment were in pathways associated with phosphatidylcholine biosynthesis, arginine and proline metabolism. Treatment with UA can reverse the levels of certain metabolites, including creatinine, creatine phosphate, and succinic acid. Pathways activated by UA treatment in UVB-irradiated HaCaT cells were associated with several biological processes, including the positive regulation of protein modification process, cell division, and enzyme-linked receptor protein signaling pathway. Treatment with UA demonstrates the capability to mitigate the effects of UVB radiation on specific genes, including S100A9 and IL6R. DNA/CpG methylation indicates that UA can partially reverse some of the alterations in the UVB-induced CpG methylome. Utilizing integrated RNA-seq and Methyl-seq data, starburst plots illustrate the correlation between mRNA expression and CpG methylation status. UA potentially influences the metabolic pathway of glycerophospholipid metabolism by modulating the expression of several key enzymes, including PLA2G2A and LPIN2. Altogether, these results indicate that UVB radiation induces metabolic reprogramming, epigenetic changes, and transcriptomic shifts. Meanwhile, UA demonstrates the capacity to inhibit or reduce the severity of these alterations, which may underlie its potential protective role against skin damage caused by UVB exposure.

People with HIV (PWH) smoke cigarettes at triple the rate of the general population in the US. Efforts to increase quit rates in this group have met with limited success. The nicotine metabolite ratio (NMR) has shown promise as a phenotypic marker that may be useful in selecting the most appropriate cessation treatments for people who smoke cigarettes. We completed a randomized controlled trial of individual intensive counseling and/or varenicline treatment for PWH in the Baltimore area who smoke cigarettes, and we measured serum 3' hydroxycotinine and cotinine at baseline and calculated the ratio of these two values, i.e. the NMR, for each participant. Herein, we present summary statistics and measures of association, or lack thereof, of NMR values with a variety of behavioral parameters and clinical outcomes related to tobacco use and tobacco treatment. NMR was calculated for 155 PWH who were currently using tobacco cigarettes. Mean age was 52.9 years, 62.3% male, 91.0% Black, and they smoked a mean of 10.6 cigarettes/day. The mean NMR was 0.43, similar to that reported from other PWH cohorts. We did not find any significant correlation between NMR and cigarettes/day, nicotine dependence, temptation to smoke, or nicotine withdrawal symptoms. We did not find that lower NMR was predictive of successful cessation, nor was it associated with varenicline intolerance in those who received varenicline.

Several studies have revealed a possible association between antibiotic use and breast cancer in the Western population of women. However, its association with the Asian population remains unclear. Data utilized in this nationwide population-based retrospective cohort study was obtained from the Korean National Health Insurance Service (NHIS) database. The study population consisted of 4,097,812 women who were followed up from January 1, 2007, to December 31, 2019. Cox proportional hazards regression was utilized to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of breast cancer according to cumulative days of antibiotic use and the number of antibiotic classes used. It was discovered that women who used antibiotics for more than 365 days had a higher risk of breast cancer (aHR, 1.15; 95% CI, 1.09-1.21) in comparison to those who did not use antibiotics. In addition, an association was found among women who used five or more classes of antibiotics, showing a higher risk of breast cancer (aHR, 1.11; 95% CI, 1.05-1.17) compared to non-users. Furthermore, compared to antibiotic non-users, only users of cephalosporins (aHR 1.09; 95% CI, 1.02-1.17) and lincosamides (aHR 1.70; 95% CI, 1.20-2.42) had a higher risk of breast cancer. These findings support epidemiological evidence that long-term use of antibiotics may be associated with a higher risk of breast cancer. This underscores the need for further studies to address the potential for residual confounding, confirm causation, and elucidate the underlying mechanisms.

Women at increased risk for breast cancer may benefit from taking risk-reducing medication (RRM) with tamoxifen (tam). Historical uptake of tam in women who qualify has been low. Recent studies have shown low-dose tam to have similar efficacy to standard dosing, with lower risk for adverse events. In this study, we aimed to evaluate uptake, adherence, and tolerability of low-dose tam in women at increased risk for breast cancer and those with ductal carcinoma in situ (DCIS). In this two-site prospective study, women who qualified for breast cancer RRM were offered participation and received consultation with a breast specialist for discussion of RRM rationale, benefits, side effects, and risks. Patients received baseline and 1-year follow-up surveys. A total of 41 patients consented for participation, and 31 completed 1-year follow-up. After initial consultation, 90% (n = 37) reported good/complete understanding of breast cancer risk. Of patients included in 1-year follow-up, 5 had DCIS, 13 had high-risk intraepithelial lesion, and 13 qualified based on Breast Cancer Risk Assessment Tool/International Breast Intervention Study calculation. Furthermore, 74% (n = 23) of patients reported that they took low-dose tam after consultation, with 78.2% (n = 18) of those still taking medication at 1 year. Patients who continued medication had higher estimated breast cancer risk compared with those who discontinued (International Breast Intervention Study 10-year risk, 12.7% vs. 7.6%; P = 0.027). All patients with DCIS initiated low-dose tam, and only one patient with DCIS had discontinued at 1 year. Uptake of low-dose tam after informed discussion is high. Adherence and tolerability at 1-year follow-up improved compared with those with traditional dosing of tam. Prevention Relevance: tam has been used extensively for breast cancer prevention in high-risk women. Historical uptake has been low because of concern for side effects and poor tolerability. Herein, we demonstrate that in the clinical setting, effective patient education and offering of a low-dose option can improve uptake in this high-risk population. See related Spotlight, p. 545.

Gastric adenocarcinoma (GAC) is the fourth leading global cause of cancer mortality and leading infection-associated cancer. High-incidence regions of GAC include Latin America and Eastern Asia. Immigrants from high-incidence regions maintain their GAC risk. GAC is a major U.S. cancer disparity, and its incidence rates are 2 to 10 times higher in non-White populations. Emerging guidelines recommend 3-year surveillance endoscopy for patients with high-risk gastric premalignant conditions (GPMC). Clinical trials of GPMC chemoprevention agents are lacking. We conducted a NCI Division of Cancer Prevention-funded, phase II placebo-controlled chemoprevention trial in patients with GPMCs (atrophic gastritis and intestinal metaplasia) with a highly bioavailable preparation of curcuminoids (Meriva). The trial sites in Puerto Rico and rural Honduras had important characteristics: (i) representative Caribbean and Mesoamerican populations, linked to large U.S. immigrant populations; (ii) high prevalence of Helicobacter pylori infection and GPMCs; (iii) the absence of turmeric and curcuminoids in local diets; and (iv) proven bidirectional collaboration with U.S. academic institutions. H. pylori-negative patients with GPMCs were randomized to the study drug (500 mg po bid) or placebo for 180 days (NCT02782949), with primary outcomes based upon histologic parameters. Principal study challenges included (i) an international regulatory environment; (ii) research infrastructure strengthening, particularly in Central America; (iii) participant recruitment in Honduras, wherein only 10% to 15% are H. pylori negative; (iv) the COVID-19 pandemic; and (v) natural disasters (three hurricanes). There were no losses to follow-up related to the pandemic or natural disasters. In conclusion, the south-south partnership provides a model for chemoprevention and translational studies in Latino populations with prevalent cancers, such as GAC.

The uptake and adherence of preventive therapy of breast cancer in clinical practice are low because of fear of serious adverse events and menopausal symptoms. Low-dose tamoxifen has been shown to retain efficacy while reducing toxicity in high-risk women. In this issue of the journal, Cornell and colleagues evaluated uptake, adherence, and tolerability of low-dose tamoxifen in high-risk women. More than 70% of patients reported that they took low-dose tamoxifen after counseling and were still taking the medication at 1 year. This paradigm shift may move the field of breast cancer prevention forward and reduce breast cancer incidence and mortality. See related article by Cornell et al., p. 565.

Metformin administration has recently emerged as a candidate strategy for the prevention of head and neck squamous cell carcinoma (HNSCC). However, the intricate relationship between genetic alterations in HNSCC and metformin sensitivity is still poorly understood, which prevents the stratification of patients, harboring oral premalignant lesions that may benefit from the chemopreventive activity of metformin. In this study, we investigate the impact of prevalent mutations in HNSCC on response to metformin. Notably, we found that the expression of oncogenic HRAS mutants confers resistance to metformin in isogenic HNSCC cell systems, and that HNSCC cells harboring endogenous HRAS mutations display limited sensitivity to metformin. Remarkably, we found that metformin fails to reduce activation of the mTOR pathway in HRAS oncogene-expressing HNSCC cells in vitro and in vivo, correlating with reduced tumor suppressive activity. Mechanistically, we found that this process depends on the ability of HRAS to enhance glycolytic metabolism, thereby suppressing the requirement for oxidative phosphorylation to maintain the cellular energetic balance. Overall, our study revealed that HNSCC cells with oncogenic HRAS mutations exhibit diminished metformin sensitivity, thus shedding light on a potential mechanism of treatment resistance. This finding may also help explain the limited clinical responses to metformin in cancers with RAS mutations. Ultimately, our study underscores the importance of understanding the impact of the genetic landscape in tailoring precision cancer-preventive approaches in the context of HNSCC and other cancers that are characterized by the presence of a defined premalignant state, and therefore, are amenable to cancer interception strategies. Prevention Relevance: Our findings highlight the challenges of using metformin for cancer prevention in RAS-mutant cancers, where elevated glycolysis may reduce drug efficacy. This underscores the need to explore metformin's potential in early, premalignant stages, before metabolic shifts render it less effective.

In the cancer early detection field, logistic regression is a frequently used approach to establish a combination rule that differentiates cancer from non-cancer. However, the application of logistic regression relies on a maximum likelihood approach, which may not yield optimal combination rules for maximizing sensitivity at a clinically desirable specificity and vice versa. Here, we have developed an improved regression framework, Sensitivity Maximization At a Given Specificity, SMAGS, for binary classification that finds the linear decision rule yielding the maximum sensitivity for a given specificity or the maximum specificity for a given sensitivity. We additionally expand the framework for feature selection that satisfies sensitivity and specificity maximizations. We compare our SMAGS method with normal logistic regression using two synthetic datasets and reported data for colorectal cancer (CRC) from the 2018 CancerSEEK study. In the CRC CancerSEEK dataset, we report 14% improvement in sensitivity at 98.5% specificity (0.31 vs 0.57; p-value:<0.05). The SMAGS method provides an alternative to logistic regression for modeling combination rules for biomarkers and early detection applications.

Oxysterols are metabolites of cholesterol that regulate the homeostasis of cholesterol, fatty acids, and glucose. These metabolites are generated throughout the body, either enzymatically or from oxidative stress, and are detectable in peripheral circulation. We previously reported that circulating 27-hydroxycholesterol (27-OHC), an endogenous selective estrogen receptor modulator, may be a risk factor for colorectal adenomas. Here, in addition to 27-OHC, we report on four other circulating oxysterols: 25-hydroxycholesterol, 24(S)-hydroxycholesterol, 7ɑ-hydroxycholesterol, and 4β-hydroxycholesterol. Oxysterol concentrations were measured using liquid chromatography/mass spectrometry from fasting plasma collected at baseline from 1,246 participants of the Vitamin D/Calcium Polyp Prevention Study, a multicenter adenoma chemoprevention trial. To evaluate multiple oxysterols simultaneously, we used both log-linear regression and Bayesian kernel machine regression models developed for analyses of complex mixtures adjusted for potential confounding factors. Higher circulating 7ɑ-hydroxycholesterol was associated with higher adenoma risk (Bayesian kernel machine regression-based multivariable-adjusted risk ratios (RR; for the 75th vs. 25th percentile, 1.22; 95% credible interval, CI, 1.04-1.42). In contrast, higher circulating 4β-hydroxycholesterol was associated with lower risk of these polyps (RR, 0.84; 95% CI, 0.71-0.99). The positive association with advanced adenoma risk that we previously reported for circulating 27-OHC persisted when controlling for other oxysterols (RR, 1.26; 95% CI, 0.98-1.62), including among those with advanced adenomas at baseline (RR, 1.75; 95% CI, 1.01-3.06). Prevention Relevance: Circulating concentrations of multiple oxysterols measured at the time of an initial colorectal adenoma diagnosis may be risk factors for subsequent incidence of these lesions. Novel colorectal cancer prevention strategies may target oxysterol formation.