The science behind vitamins and natural compounds for breast cancer prevention. Getting the most prevention out of it

Suppression of oral cancer by induction of cell cycle arrest and apoptosis using Juniperus communis extract

The oral cancer incidence rate is slowly increasing and is now the fifth leading cause of cancer-related death due to its high metastasis and recurrence rate. Juniperus communis is used as a traditional Chinese medicine and has been proven to have anti-cancer activity against neuroblastomas. In the present study, we further investigated the anti-cancer mechanisms of J. communis extract (JCo) on oral cancer and evaluated the synergistic effects of JCo combined with 5-fluorouracil (5-FU). We found that JCo inhibited oral cancer cell growth, and that JCo might be less cytotoxic to normal cells than to cancer cells. After JCo treatment, cell cycle arrest was observed at the G₀/G₁ phase through modulation of p53/p21 and Rb signaling. JCo also caused an increase in the sub-G₁ phase and cell apoptosis via the intrinsic and extrinsic apoptosis pathways. JCo combined with 5-FU presented a synergistic effect to reduce cell viability. In conclusion, JCo inhibited oral cancer cell growth by inducing cell cycle arrest and activating cell apoptosis, and JCo significantly synergized with 5-FU. JCo might have the potential to be an adjuvant and a new therapeutic drug for oral cancer treatment.

Is There an Association between β-Carotene and Breast Cancer? A Systematic Review on Breast Cancer Risk

It is suspected that diet influences the risk of developing breast cancer. Several β-carotenoids have been inversely associated with breast cancer risk, but association by type of tumor and participant characteristics remain nuclear. The objective of this review of epidemiological studies is to investigate the relationship between β-carotenoids and breast cancer. This review covers the 2014-2020 period and was carried out using the PubMed and EMBASE databases. Only epidemiological studies carried out on β-carotenoids and breast cancer were included. The initial keyword search yielded 1559 results and finally a total of 28 studies were included. The quality of the articles and the risk of bias for each included article were assessed. The selected articles were subsequently classified according to their quality. The evidence from the included studies confirms that there is an association between β-carotenoids and breast cancer risk; the dietary intake of β-carotenoids may be beneficial in reducing the risk of developing breast cancer.

The Role of Adipokines in Breast Cancer: Current Evidence and Perspectives

PURPOSE

The current review shows evidence for the role of adipokines in breast cancer (BC) pathogenesis summarizing the mechanisms underlying the association between adipokines and breast malignancy. Special emphasis is given also on intriguing insights into the relationship between obesity and BC as well as on the role of novel adipokines in BC development.

RECENT FINDINGS

Recent evidence has underscored the role of the triad of obesity, insulin resistance, and adipokines in postmenopausal BC. Adipokines exert independent and joint effects on activation of major intracellular signal networks implicated in BC cell proliferation, growth, survival, invasion, and metastasis, particularly in the context of obesity, considered a systemic endocrine dysfunction characterized by chronic inflammation. To date, more than 10 adipokines have been linked to BC, and this catalog is continuously increasing. The majority of circulating adipokines, such as leptin, resistin, visfatin, apelin, lipocalin 2, osteopontin, and oncostatin M, is elevated in BC, while some adipokines such as adiponectin and irisin (adipo-myokine) are generally decreased in BC and considered protective against breast carcinogenesis. Further evidence from basic and translational research is necessary to delineate the ontological role of adipokines and their interplay in BC pathogenesis. More large-scale clinical and longitudinal studies are awaited to assess their clinical utility in BC prognosis and follow-up. Finally, novel more effective and safer adipokine-centered therapeutic strategies could pave the way for targeted oncotherapy.

Risk-reducing medications for primary breast cancer: a network meta-analysis

BACKGROUND

Breast cancer is the most frequently occurring malignancy and the second cause of death for cancer in women. Cancer prevention agents (CPAs) are a promising approach to reduce the burden of breast cancer. Currently, two main types of CPAs are available: selective estrogen receptor modulators (SERMs, such as tamoxifen and raloxifene) and aromatase inhibitors (AIs, such as exemestane and anastrozole).

OBJECTIVES

To assess the efficacy and acceptability of single CPAs for the prevention of primary breast cancer, in unaffected women, at an above-average risk of developing breast cancer.Using a network meta-analysis, to rank single CPAs, based on their efficacy and acceptability (an endpoint that is defined as the inverse of CPA-related toxicity).

SEARCH METHODS

We searched the Cochrane Breast Cancer Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP), and ClinicalTrials.gov on 17 August 2018. We handsearched reference lists to identify additional relevant studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that enrolled women without a personal history of breast cancer but with an above-average risk of developing a tumor. Women had to be treated with a CPA and followed up to record the occurrence of breast cancer and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and conducted risk of bias assessments of the included studies, and assessed the certainty of the evidence using GRADE. Outcome data included incidence of breast carcinoma (both invasive and in situ carcinoma) and adverse events (both overall and severe toxicity). We performed a conventional meta-analysis (for direct comparisons of a single CPA with placebo or a different CPA) and network meta-analysis (for indirect comparisons).

MAIN RESULTS

We included six studies enrolling 50,927 women randomized to receive one CPA (SERMs: tamoxifen or raloxifene, or AIs: exemestane or anastrozole) or placebo. Three studies compared tamoxifen and placebo, two studies compared AIs (exemestane or anastrozole) versus placebo, and one study compared tamoxifen versus raloxifene. The risk of bias was low for all RCTs.For the tamoxifen versus placebo comparison, tamoxifen likely resulted in a lower risk of developing breast cancer compared to placebo (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.62 to 0.76; 3 studies, 22,832 women; moderate-certainty evidence). In terms of adverse events, tamoxifen likely increased the risk of severe toxicity compared to placebo (RR 1.28, 95% CI 1.12 to 1.47; 2 studies, 20,361 women; moderate-certainty evidence). In particular, women randomized to receive tamoxifen experienced a higher incidence of both endometrial carcinoma (RR 2.26, 95% CI 1.52 to 3.38; high-certainty evidence) and thromboembolism (RR 2.10, 95% CI 1.14 to 3.89; high-certainty evidence) compared to women who received placebo.For the AIs versus placebo comparison, AIs (exemestane or anastrozole) reduced the risk of breast cancer by 53% (RR 0.47, 95% CI 0.35 to 0.63; 2 studies, 8424 women; high-certainty evidence). In terms of adverse events, AIs increased the risk of severe toxicity by 18% (RR 1.18, 95% CI 1.09 to 1.28; 2 studies, 8352 women; high-certainty evidence). These differences were sustained especially by endocrine (e.g. hot flashes), gastrointestinal (e.g. diarrhea), and musculoskeletal (e.g. arthralgia) adverse events, while there were no differences in endometrial cancer or thromboembolism rates between AIs and placebo.For the tamoxifen versus raloxifene comparison, raloxifene probably performed worse than tamoxifen in terms of breast cancer incidence reduction (RR 1.25, 95% CI 1.09 to 1.43; 1 study, 19,490 women; moderate-certainty evidence), but its use was associated with lower toxicity rates (RR 0.87, 95% CI 0.80 to 0.95; 1 study, 19,490 women; moderate-certainty evidence), particularly relating to incidence of endometrial cancer and thromboembolism.An indirect comparison of treatment effects allowed us to compare the SERMs and AIs in this review. In terms of efficacy, AIs (exemestane or anastrozole) may have reduced breast cancer incidence slightly compared to tamoxifen (RR 0.67, 95% CI 0.46 to 0.98; 5 RCTs, 31,256 women); however, the certainty of evidence was low. A lack of model convergence did not allow us to analyze toxicity data.

AUTHORS' CONCLUSIONS

For women with an above-average risk of developing breast cancer, CPAs can reduce the incidence of this disease. AIs appear to be more effective than SERMs (tamoxifen) in reducing the risk of developing breast cancer. AIs are not associated with an increased risk of endometrial cancer and thromboembolic events. However, long-term data on toxicities from tamoxifen are available while the follow-up toxicity data on unaffected women taking AIs is relatively short. Additional data from direct comparisons are needed to fully address the issues of breast cancer prevention by risk-reducing medications, with special regards to acceptability (i.e. the benefit/harm ratio).

Could Aspirin and Diets High in Fiber Act Synergistically to Reduce the Risk of Colon Cancer in Humans?

Early inhibition of inflammation suppresses the carcinogenic process. Aspirin is the most commonly used non-steroid anti-inflammatory drugs (NSAIDs), and it irreversibly inhibits cyclooxygenase-1 and -2 (COX1, COX2). Multiple randomized clinical trials have demonstrated that aspirin offers substantial protection from colon cancer mortality. The lower aspirin doses causing only minimal gastrointestinal disturbance, ideal for long-term use, can achieve only partial and transitory inhibition of COX2. Aspirin’s principal metabolite, salicylic acid, is also found in fruits and vegetables that inhibit COX2. Other phytochemicals such as curcumin, resveratrol, and anthocyanins also inhibit COX2. Such dietary components are good candidates for combination with aspirin because they have little or no toxicity. However, obstacles to using phytochemicals for chemoprevention, including bioavailability and translational potential, must be resolved. The bell/U-shaped dose–response curves seen with vitamin D and resveratrol might apply to other phytochemicals, shedding doubt on ‘more is better’. Solutions include: (1) using special delivery systems (e.g., nanoparticles) to retain phytochemicals; (2) developing robust pharmacodynamic biomarkers to determine efficacy in humans; and (3) selecting pharmacokinetic doses relevant to humans when performing preclinical experiments. The combination of aspirin and phytochemicals is an attractive low-cost and low-toxicity approach to colon cancer prevention that warrants testing, particularly in high-risk individuals.

A Randomized Study of the Effects of Additional Fruit and Nuts Consumption on Hepatic Fat Content, Cardiovascular Risk Factors and Basal Metabolic Rate

Background

Fruit has since long been advocated as a healthy source of many nutrients, however, the high content of sugars in fruit might be a concern.

Objectives

To study effects of an increased fruit intake compared with similar amount of extra calories from nuts in humans.

Methods

Thirty healthy non-obese participants were randomized to either supplement the diet with fruits or nuts, each at +7 kcal/kg bodyweight/day for two months. Major endpoints were change of hepatic fat content (HFC, by magnetic resonance imaging, MRI), basal metabolic rate (BMR, with indirect calorimetry) and cardiovascular risk markers.

Results

Weight gain was numerically similar in both groups although only statistically significant in the group randomized to nuts (fruit: from 22.15±1.61 kg/m² to 22.30±1.7 kg/m², p = 0.24 nuts: from 22.54±2.26 kg/m² to 22.73±2.28 kg/m², p = 0.045). On the other hand BMR increased in the nut group only (p = 0.028). Only the nut group reported a net increase of calories (from 2519±721 kcal/day to 2763±595 kcal/day, p = 0.035) according to 3-day food registrations. Despite an almost three-fold reported increased fructose-intake in the fruit group (from 9.1±6.0 gram/day to 25.6±9.6 gram/day, p<0.0001, nuts: from 12.4±5.7 gram/day to 6.5±5.3 gram/day, p = 0.007) there was no change of HFC. The numerical increase in fasting insulin was statistical significant only in the fruit group (from 7.73±3.1 pmol/l to 8.81±2.9 pmol/l, p = 0.018, nuts: from 7.29±2.9 pmol/l to 8.62±3.0 pmol/l, p = 0.14). Levels of vitamin C increased in both groups while α-tocopherol/cholesterol-ratio increased only in the fruit group.

Conclusions

Although BMR increased in the nut-group only this was not linked with differences in weight gain between groups which potentially could be explained by the lack of reported net caloric increase in the fruit group. In healthy non-obese individuals an increased fruit intake seems safe from cardiovascular risk perspective, including measurement of HFC by MRI.

Trial Registration

ClinicalTrials.gov NCT02227511

New concepts and challenges in the clinical translation of cancer preventive therapies: the role of pharmacodynamic biomarkers

Implementation of therapeutic cancer prevention strategies has enormous potential for reducing cancer incidence and related mortality. Trials of drugs including tamoxifen and aspirin have led the way in demonstrating proof-of-principle that prevention of breast and colorectal cancer is feasible. Many other compounds ranging from drugs in widespread use for various indications, including metformin, bisphosphonates, and vitamin D, to dietary agents such as the phytochemicals resveratrol and curcumin, show preventive activity against several cancers in preclinical models. Notwithstanding the wealth of opportunities, major challenges have hindered the development process and only a handful of therapies are currently approved for cancer risk reduction. One of the major obstacles to successful clinical translation of promising preventive agents is a lack of pharmacodynamic biomarkers to provide an early read out of biological activity in humans and for optimising doses to take into large scale randomised clinical trials. A further confounding factor is a lack of consideration of clinical pharmacokinetics in the design of preclinical experiments, meaning results are frequently reported from studies that use irrelevant or unachievable concentrations. This article focuses on recent findings from investigations with dietary-derived agents to illustrate how a thorough understanding of the mechanisms of action, using models that mimic the clinical scenario, together with the development of compound-specific accompanying pharmacodynamic biomarkers could accelerate the developmental pipeline for preventive agents and maximise the chances of success in future clinical trials. Moreover, the concept of a bell-shaped dose-response curve for therapeutic cancer prevention is discussed, along with the need to rethink the traditional ‘more is better’ approach for dose selection.

Folic acid supplements and colorectal cancer risk: meta-analysis of randomized controlled trials

Numerous studies have investigated the effects of folic acid supplementation on colorectal cancer risk, but conflicting results were reported. We herein performed a meta-analysis based on relevant studies to reach a more definitive conclusion. The PubMed and Embase databases were searched for quality randomized controlled trials (RCTs) published before October 2014. Eight articles met the inclusion criteria and were subsequently analyzed. The results suggested that folic acid treatment was not associated with colorectal cancer risk in the total population (relative risk [RR] = 1.00, 95% confidence interval [CI] = 0.82–1.22, P = 0.974). Moreover, no statistical effect was identified in further subgroup analyses stratified by ethnicity, gender, body mass index (BMI) and potential confounding factors. No significant heterogeneity or publication bias was observed. In conclusion, our meta-analysis demonstrated that folic acid supplementation had no effect on colorectal cancer risk. However, this finding must be validated by further large studies.

Butein suppresses cervical cancer growth through the PI3K/AKT/mTOR pathway

Cervical cancer is the second most common women carcinoma worldwide and the fourth leading cause of cancer-associated mortality in women. Butein, a bioactive flavonoid isolated from numerous native plants, has been shown to induce apoptosis and inhibits migration and invasion in numerous human cancer cells. However, to the best of our knowledge, the effect of butein on human cervical cancer cells has not been reported. The present study aimed to determine the effect of butein on cell growth, apoptosis, migration and invasion and identify the associated molecular mechanism involved using HeLa human cervical cancer cells in vitro, and on tumor growth in a nude mouse model. It was found that butein notably inhibited cell viability, colony formation, migration and invasion, induced cell cycle at the G2/M stage and cell apoptosis, as well as enhanced caspase-3, -8 and -9 activity in HeLa cells in a dose-dependent manner. When administered intraperitoneally, butein inhibited the tumor growth of human cervical cancer xenograft tumors in the nude mouse model. Additionally, treatment with butein significantly increased reactive oxygen species (ROS) generation and reduced the phosphorylation of PI3K, AKT and mTOR expression, which contributes to the inhibition of the tumor growth of cervical cancer and reduction of oxidative stress. These findings suggested that butein serves as a potential therapeutic agent for the treatment of cervical cancer.

VDR primary targets by genome-wide transcriptional profiling

There is growing evidence that 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) plays a role in breast cancer prevention and survival. It elicits a variety of antitumor activities like controlling cellular differentiation, proliferation and angiogenesis. Most of its biological effects are exerted via its nuclear receptor which acts as a transcriptional regulator. Here, we carried out a genome-wide investigation of the primary transcriptional targets of 1α,25(OH)2D3 in breast epithelial cancer cells using RNA-Seq technology. We identified early transcriptional targets of 1α,25(OH)2D3 involved in adhesion, growth regulation, angiogenesis, actin cytoskeleton regulation, hexose transport, inflammation and immunomodulation, apoptosis, endocytosis and signaling. Furthermore, we found several transcription factors to be regulated by 1α,25(OH)2D3 that subsequently amplify and diversify the transcriptional output driven by 1α,25(OH)2D3 leading finally to a growth arrest of the cells. Moreover, we could show that 1α,25(OH)2D3 elevates the trimethylation of histone H3 lysine 4 at several target gene promoters. Our present transcriptomic analysis of differential expression after 1α,25(OH)2D3 treatment provides a resource of primary 1α,25(OH)2D3 targets that might drive the antiproliferative action in breast cancer epithelial cells.

NAC, tiron and trolox impair survival of cell cultures containing glioblastoma tumorigenic initiating cells by inhibition of cell cycle progression

Reactive oxygen species (ROS) are metabolism by-products that may act as signaling molecules to sustain tumor growth. Antioxidants have been used to impair cancer cell survival. Our goal was to determine the mechanisms involved in the response to antioxidants of a human cell culture (PT4) containing glioblastoma (GBM) tumorigenic initiating cells (TICs). ROS production in the absence or presence of N-acetyl-L-cysteine (NAC), tiron, and trolox was evaluated by flow cytometry (FCM). The effects of these antioxidants on cell survival and apoptosis were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and FCM. The biological processes modulated by these drugs were determined by oligonucleotide microarray gene expression profiling. Our results showed that NAC, tiron and trolox impaired PT4 cell survival, had minor effects on ROS levels and caused wide deregulation of cell cycle genes. Furthermore, tiron and trolox caused inhibition of cell survival in two additional cell cultures containing TICs, FO-1 and MM1, established from a melanoma and a mesothelioma patient, respectively. NAC, instead, impaired survival of the MM1 cells but not of the FO-1 cells. However, when used in combination, NAC enhanced the inhibitory effect of PLX4032 (BRAF V600E inhibitor) and Gefitinib (EGFR inhibitor), on FO-1 and PT4 cell survival. Collectively, NAC, tiron and trolox modulated gene expression and impaired the growth of cultures containing TICs primarily by inhibiting cell cycle progression.

Guidance for the prevention of bone loss and fractures in postmenopausal women treated with aromatase inhibitors for breast cancer: an ESCEO position paper

Aromatase inhibitors (AIs) are widely used in women with breast cancer, but they are known to increase bone loss and risk of fractures. Based on available evidence and recommendations, an ESCEO working group proposes specific guidance for the prevention of AIs-induced bone loss and fragility fractures.

INTRODUCTION

Aromatase inhibitors (AIs) are now the standard treatment for hormone receptor-positive breast cancer. However, deleterious effects of AIs on bone health have been reported. An ESCEO working group proposes guidance for the prevention of bone loss and fragility fractures in post-menopausal women with breast cancer receiving AIs.

METHODS

A panel of experts addressed the issue of skeletal effects of AIs and effectiveness of antifracture therapies for the prevention of AI-induced bone loss and fractures. Recommendations by national and international organizations, and experts' opinions on this topic were evaluated.

RESULTS

All aromatase inhibitors are associated with negative effects on the skeleton, resulting in bone loss and increased risk of fragility fractures. Current guidelines suggest approaches that differ both in terms of drugs proposed for fracture prevention and duration of treatment.

CONCLUSION

The ESCEO working group recommends that all AI-treated women should be evaluated for fracture risk. Besides general recommendations, zoledronic acid 4 mg i.v. every 6 months, denosumab s.c., or possibly oral bisphosphonates should be administered for the entire period of AI treatment to all osteoporotic women (T-score hip/spine <-2.5 or ≥ 1 prevalent fragility fracture), to women aged ≥ 75 irrespective of BMD, and to patients with T-score <-1.5 + ≥ 1 clinical risk factor or T-score <-1.0 + ≥ 2 clinical risk factors. Alternatively, therapy could be considered in patients with a FRAX-determined 10-year hip fracture probability ≥ 3%.