Red Meat and Colorectal Cancer

Roles for selenium and selenoprotein P in the development, progression, and prevention of intestinal disease

Selenium (Se) is a micronutrient essential to human health, the function of which is mediated in part by incorporation into a class of proteins known as selenoproteins (SePs). As many SePs serve antioxidant functions, Se has long been postulated to protect against inflammation and cancer development in the gut by attenuating oxidative stress. Indeed, numerous studies over the years have correlated Se levels with incidence and severity of intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). Similar results have been obtained with the Se transport protein, selenoprotein P (SELENOP), which is decreased in the plasma of both IBD and CRC patients. While animal models further suggest that decreases in Se or SELENOP augment colitis and intestinal tumorigenesis, large-scale clinical trials have yet to show a protective effect in patient populations. In this review, we discuss the function of Se and SELENOP in intestinal diseases and how research into these mechanisms may impact patient treatment.

Visceral obesity as a risk factor for colorectal adenoma occurrence in surveillance colonoscopy

BACKGROUND AND AIMS

The aim of this study was to examine the prospective association between visceral obesity and the incidence and recurrence of colorectal adenoma.

METHODS

We conducted a cohort study involving 2244 participants between 2006 and 2007. The study participants were prospectively followed until 2014 according to the initial colonoscopy and histopathology findings. Incident and recurrent colorectal adenoma groups were defined as individuals with a positive follow-up colonoscopy result from the normal results and adenoma groups, respectively, at the baseline colonoscopy.

RESULTS

Among the 1163 patients (51.8%) who received a follow-up colonoscopy, 509 (43.8%) and 654 (56.2%) were grouped into the normal and adenoma cohorts. Colorectal adenomas occurred in 592 patients (50.9%) during the median period of 43 months, with an incident adenoma prevalence of 39.1% and a recurrent adenoma prevalence of 60.1%. An increase in the visceral adipose tissue (VAT) area was associated with a higher incidence of adenoma (highest quintile vs lowest quintile of the VAT hazard ratios [HRs], 2.16; 95% confidence interval [CI], 1.26-3.71; HR 1.32 [per 1-standard deviation]; 95% CI, 1.10-1.60) in the multivariable analysis. Increases in body mass index and waist circumference were associated with recurrent adenomas (HR 1.33 [per 1 kg/m²], 95% CI, 1.18-1.46; HR 1.04 [per 1 cm], 95% CI, 1.01-1.07, respectively) in the multivariate analysis.

CONCLUSION

A higher VAT area was dose-dependently associated with a higher risk of incident adenoma. Furthermore, increases in body mass index and waist circumference as surrogate markers of abdominal obesity were associated with a higher risk of recurrent adenoma.

Impact of dietary compounds on cancer-related gut microbiota and microRNA

Cancer is one of the most common causes of death worldwide. Extensive research has been conducted on cancer; regardless, the link between cancer and diet remains undetermined. Recent studies have emphasized the importance of miRNAs in cancer-associated pathways from the perspective of dietary modulation. We highlighted the recent data on dietary modulation of gut microbiota and miRNAs related to cancer on the basis of recently published results. The targets of miRNAs are oncogenes or tumor suppressors that mediate the progression and initiation of carcinogenesis. Different miRNAs display complex expression profiles in response to dietary manipulation. Various dietary components, such as fatty acids, resveratrol, isothiocyanate, and curcumin, have been effectively used in cancer prevention and treatment. This potency is attributed to the capability of these components to alter miRNA expression, thereby modulating the vital pathways involved in metastasis, invasion, apoptosis, tumor growth, and cell proliferation.

Lung cancer patients with synchronous colon cancer

Lung and colon cancers are two of the most common malignancies, which, in some cases, may develop synchronously. In the present study, the treatment and outcome of patients with synchronous lung and colon cancers were reviewed. During a 76-month study period, from April 2009 up to July 2016, 17 (0.54%) of 3,102 patients with lung cancer were diagnosed with colon cancer within 1 month. Heavy smoking and obesity were not specific factors in these patients. A total of 9 patients succumbed to lung cancer during the study period. Survival in asymptomatic patients was longer compared with that in symptomatic patients (median survival, 80 vs. 23.2 months, respectively; P=0.007). Although the incidence of synchronous occurrence of these two cancers may be low, particularly in patients diagnosed incidentally, such patients should be treated accordingly. Future genetic and epidemiological studies are required to elucidate the potential connection between lung and colon cancer.

Lack of Association between Red Meat Consumption and a Positive Fecal Immunochemical Colorectal Cancer Screening Test in Khon Kaen, Thailand: a Population- Based Randomized Controlled Trial

Background:

There is convincing evidence from epidemiological studies that meat consumption increases colorectal cancer (CRC) risk. However, assessment of any association with a positive fecal immunochemical test (FIT) in CRC screening has been limited. If a link could be shown this might be helpful for establishing a risk group for colonoscopy.

Objective:

This study aimed to assess any association between meat consumption and other lifestyle factors and a positive FIT result in a Thai population.

Methods:

A cross-sectional analytical study was conducted with 1,167 participants in a population-based randomized controlled trial. CRC was screened from May 2016 - February 2017. Subjects aged 45-74 years who met the eligibility criteria were randomly allocated to the study arm. A positive FIT was determined with cut-off 100 ng/mL. Multiple logistic regression was used to analyze any relationship between lifestyle factors and a positive FIT.

Result:

The total number of subjects was 1,060 (90.8% return rate of FIT). With FIT100, FIT150, and FIT200, positive tests were found in 92 (8.68%), 74 (6.98%), and 60 (5.66%), respectively. No significant associations were noted with any of the variables, except for being aged 60-74 years (ORadj = 1.62, 95%CI: 1.03-2.54) Borderline significance was observed for high consumption of vegetables (ORadj = 0.62, 95%CI: 0.36-1.07) and being male (ORadj = 1.39, 95%CI:0.87-2.22).

Conclusion:

Despite the evidence from the literature, no association was here found between a positive FIT result and meat consumption or other well-established lifestyle parameters. Being aged 60-74 years was a risk factor which should be taken into account in CRC screening strategy in countries like Thailand with limited access to endoscopy.

In vivo and in vitro induction of the apoptotic effects of oxysophoridine on colorectal cancer cells via the Bcl-2/Bax/caspase-3 signaling pathway

Oxysophoridine (OSR) is a major active alkaloid extracted from Sophoraalopecuroides L. The aim of the present study was to investigate the induction of the apoptotic effects of OSR on colorectal cancer cells in vivo and in vitro. The results of the MTT and colony formation assays demonstrated that the proliferation of HCT116 cells was inhibited by OSR in vitro. The characteristics of cellular apoptosis in OSR-treated HCT116 cells were analyzed by Hoechst 33258 staining. It was also observed that the expression of caspase-3, B-cell lymphoma-2 (Bcl-2) associated X protein (Bax) and cytochrome c increased significantly upon OSR treatment. However, the expression of Bcl-2 and poly ADP-ribose polymerase-1 (PARP-1) was downregulated in OSR-treated cells compared with untreated cells. The in vivo experiments identified that OSR significantly inhibited the growth of the transplanted mouse CT26 tumor tissue, upregulated the expression of caspase-3, Bax and cytochrome c and downregulated the expression of Bcl-2 and PARP-1, as detected by reverse transcription-quantitative polymerase chain reaction and western blotting. It may be concluded that OSR significantly induced apoptotic effects on colorectal cancer cells in vivo and in vitro, and that its mechanism may be associated with the Bcl-2/Bax/caspase-3 signaling pathway.

Pro-inflammatory fatty acid profile and colorectal cancer risk: A Mendelian randomisation analysis

BACKGROUND

While dietary fat has been established as a risk factor for colorectal cancer (CRC), associations between fatty acids (FAs) and CRC have been inconsistent. Using Mendelian randomisation (MR), we sought to evaluate associations between polyunsaturated (PUFA), monounsaturated (MUFA) and saturated FAs (SFAs) and CRC risk.

METHODS

We analysed genotype data on 9254 CRC cases and 18,386 controls of European ancestry. Externally weighted polygenic risk scores were generated and used to evaluate associations with CRC per one standard deviation increase in genetically defined plasma FA levels.

RESULTS

Risk reduction was observed for oleic and palmitoleic MUFAs (OROA = 0.77, 95% CI: 0.65-0.92, P = 3.9 × 10-3; ORPOA = 0.36, 95% CI: 0.15-0.84, P = 0.018). PUFAs linoleic and arachidonic acid had negative and positive associations with CRC respectively (ORLA = 0.95, 95% CI: 0.93-0.98, P = 3.7 × 10-4; ORAA = 1.05, 95% CI: 1.02-1.07, P = 1.7 × 10-4). The SFA stearic acid was associated with increased CRC risk (ORSA = 1.17, 95% CI: 1.01-1.35, P = 0.041).

CONCLUSION

Results from our analysis are broadly consistent with a pro-inflammatory FA profile having a detrimental effect in terms of CRC risk.

The Association between Lifestyle, Occupational, and Reproductive Factors and Colorectal Cancer Risk

Objective: Association of lifestyle, reproductive and environmental factors has been investigated with increased risk of colorectal cancer in different studies. We explored evidence and investigated association between various risk factors and colorectal cancer. Methods: This case- control study was conducted 155 colorectal cancer patients and 150 hospital-controls. We obtained detailed lifestyle, occupational, reproductive information from both groups. Chi-Square test and Logistic regression model were used to evaluate the risk factors of colorectal cancer. Results: The results showed that frequent intake of fruits, chicken, fish and alcohol drinking were associated with risk for colorectal cancer. Agricultural occupation (OR=7.003, 95% CI=2.19-22.38) and industrial exposure (OR=1.97, 95% CI=0.91-4.22) were associated significantly with risk for colorectal cancer. Regarding reproductive factors, women who reported less than 3 pregnancies was associated with an increased risk of colorectal carcinoma (OR=2.88, 95% CI=1.15-7.17). We did not find significant association between other reproductive factors and colorectal cancer risk in women after adjusting for demographic factors. Conclusion: In this case-control study we observed that agricultural occupation, industrial exposure and high consumption of fish and less than 3 pregnancies in women were associated with an increased risk of colorectal carcinoma.

Genetic polymorphisms of superoxide dismutase-1 A251G and catalase C-262T with the risk of colorectal cancer

Oxidative stress is significant in numerous types of disease including cancer. To protect cells and organs against reactive oxygen species (ROS), the body has evolved an antioxidant protection system that involved in the detoxification of ROS. Single nucleotide polymorphisms (SNP) of anti-oxidative enzymes may dramatically change the activity of the encoded proteins; therefore, certain alleles can be established as risk factors for some kind of multi-factorial diseases including cancer. In present study we investigate the possible association between polymorphisms of superoxide dismutase 1 (SOD1, OMIM: 147450) and catalase (CAT, OMIM: 115500) genes and the risk of colorectal cancer (CRC). The study included 204 colorectal cancer patients and 239 healthy control group matched for gender and age. Genotyping of SOD1 A251G and CAT C-262T were done by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. There was no significant association between CAT C-262T polymorphism and susceptibility to CRC (P>0.05). The carries of the G allele of SOD1 significantly showed higher prevalence in CRC patients compared with the control group (OR=1.84, 95% CI=1.13-2.98, P=0.013). We assessed the effect of combination of genotypes of the study polymorphisms on the risk of CRC. We found that the combination of AG+GG (SOD1) and CC (CAT) increases the risk of developing CRC (OR=2.38, 95% CI=1.25-4.52, P=0.008).

Evidence that supports the prescription of low-carbohydrate high-fat diets: a narrative review

Low-carbohydrate high-fat (LCHF) diets are a highly contentious current topic in nutrition. This narrative review aims to provide clinicians with a broad overview of the effects of LCHF diets on body weight, glycaemic control and cardiovascular risk factors while addressing some common concerns and misconceptions. Blood total cholesterol and LDL-cholesterol concentrations show a variable, highly individual response to LCHF diets, and should be monitored in patients adhering to this diet. In contrast, available evidence from clinical and preclinical studies indicates that LCHF diets consistently improve all other markers of cardiovascular risk-lowering elevated blood glucose, insulin, triglyceride, ApoB and saturated fat (especially palmitoleic acid) concentrations, reducing small dense LDL particle numbers, glycated haemoglobin (HbA_1c) levels, blood pressure and body weight while increasing low HDL-cholesterol concentrations and reversing non-alcoholic fatty liver disease (NAFLD). This particular combination of favourable modifications to all these risk factors is a benefit unique to LCHF diets. These effects are likely due in part to reduced hunger and decreased ad libitum calorie intake common to low-carbohydrate diets, allied to a reduction in hyperinsulinaemia, and reversal of NAFLD. Although LCHF diets may not be suitable for everyone, available evidence shows this eating plan to be a safe and efficacious dietary option to be considered. LCHF diets may also be particularly beneficial in patients with atherogenic dyslipidaemia, insulin resistance, and the frequently associated NAFLD.

Dietary Patterns Among Overweight and Obese African-American Women Living in the Rural South

INTRODUCTION

Obesity and chronic diseases disproportionately affect African-American women in the rural South (US) and may be influenced by adherence to a typical Southern-style diet. There is a need to examine dietary patterns of this population and to determine if consumption of nutritionally rich foods like nuts is associated with consumption of other nutritious foods. The objectives of this study were to identify (1) dietary patterns of overweight/obese African-American women in the rural South; (2) the role that nuts play in the diet; (3) and adherence to federal food group recommendations across dietary patterns.

METHODS

Secondary data analysis of two baseline 24-h dietary recalls was performed on 383 overweight/obese African-American women enrolled in a weight loss intervention in Alabama and Mississippi between 2011 and 2013. Cluster analysis identified dietary patterns. t tests and chi-square tests tested demographic and dietary differences across clusters. The proportion of women in each cluster who met federal recommendations for fruit, vegetable, nuts, added sugar, and sodium intake was calculated.

RESULTS

Two dietary patterns were found. Nut intake frequency was higher in cluster 2 (P < .001), which was characterized by a higher intake frequency of fruits and vegetables, but high mean daily intake of added sugar (12.26 ± 7.67 tsp) and sodium (2800 ± 881 mg). Ninety-two percent of participants in this cluster consumed red/processed meats daily.

CONCLUSION

Even among women in this population who consume a more plant-based dietary pattern containing nuts, there is still a need to decrease intake of added sugar, sodium, and red meat.

Xenotransplantation - A special case of One Health

The chronic shortage of human transplants to treat tissue and organ failure has led to the development of xenotransplantation, the transplantation of cells, tissues and organs from another species to human recipients. For a number of reasons, pigs are best suited as donor animals. Successful, routine xenotransplantation would have an enormous impact on the health of the human population, including the young, who sometimes require a replacement organ or islet cells, but especially the elderly, who more often suffer the consequences of organ failure. The first form of xenotransplantation applied to humans is the use of pig islet cells to treat insulin-dependent diabetes, a procedure that will have a significant economic impact. However, although xenotransplantation using pig cells, tissues and organs may save and prolong the lives of patients, it may also be associated with the transmission of porcine microorganisms to the recipient, eventually resulting in emerging infectious diseases. For this reason, the health of both the donor animals and the human recipients represents a special and sensitive case of the One Health concept. Basic research leading to strategies how to prevent transmission of porcine microorganisms by selection of virus-free animals, treatment of donor pigs by antiviral drugs, vaccines, colostrum deprivation, early weaning, Caesarean delivery, embryo transfer and/or gene editing should be undertaken to supply an increasing number of potential recipients with urgently required transplants. The methods developed for the detection and elimination of porcine microorganisms in the context of xenotransplantation will also contribute to an improvement in the health of pig populations in general and an increase in the quality of meat products. At present, there is evidence for transmission of porcine viruses to humans eating pork and having contact with pigs, however the impact of these viruses on public health is still unknown.

Colorectal Carcinoma: A General Overview and Future Perspectives in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death. Most cases of CRC are detected in Western countries, with its incidence increasing year by year. The probability of suffering from colorectal cancer is about 4%–5% and the risk for developing CRC is associated with personal features or habits such as age, chronic disease history and lifestyle. In this context, the gut microbiota has a relevant role, and dysbiosis situations can induce colonic carcinogenesis through a chronic inflammation mechanism. Some of the bacteria responsible for this multiphase process include Fusobacterium spp, Bacteroides fragilis and enteropathogenic Escherichia coli. CRC is caused by mutations that target oncogenes, tumour suppressor genes and genes related to DNA repair mechanisms. Depending on the origin of the mutation, colorectal carcinomas can be classified as sporadic (70%); inherited (5%) and familial (25%). The pathogenic mechanisms leading to this situation can be included in three types, namely chromosomal instability (CIN), microsatellite instability (MSI) and CpG island methylator phenotype (CIMP). Within these types of CRC, common mutations, chromosomal changes and translocations have been reported to affect important pathways (WNT, MAPK/PI3K, TGF-β, TP53), and mutations; in particular, genes such as c-MYC, KRAS, BRAF, PIK3CA, PTEN, SMAD2 and SMAD4 can be used as predictive markers for patient outcome. In addition to gene mutations, alterations in ncRNAs, such as lncRNA or miRNA, can also contribute to different steps of the carcinogenesis process and have a predictive value when used as biomarkers. In consequence, different panels of genes and mRNA are being developed to improve prognosis and treatment selection. The choice of first-line treatment in CRC follows a multimodal approach based on tumour-related characteristics and usually comprises surgical resection followed by chemotherapy combined with monoclonal antibodies or proteins against vascular endothelial growth factor (VEGF) and epidermal growth receptor (EGFR). Besides traditional chemotherapy, alternative therapies (such as agarose tumour macrobeads, anti-inflammatory drugs, probiotics, and gold-based drugs) are currently being studied to increase treatment effectiveness and reduce side effects.

The Role of Bioactive Dietary Components in Modulating miRNA Expression in Colorectal Cancer

Colorectal cancer is the third most common cancer in the world and considered to be one of the most diet-related types of cancer. Extensive research has been conducted but still the link between diet and colorectal cancer is complex. Recent studies have highlight microRNAs (miRNAs) as key players in cancer-related pathways in the context of dietary modulation. MicroRNAs are involved in most biological processes related to tumor development and progression; therefore, it is of great interest to understand the underlying mechanisms by which dietary patterns and components influence the expression of these powerful molecules in colorectal cancer. In this review, we discuss relevant dietary patterns in terms of miRNAs modulation in colorectal cancer, as well as bioactive dietary components able to modify gene expression through changes in miRNA expression. Furthermore, we emphasize on protective components such as resveratrol, curcumin, quercetin, α-mangostin, omega-3 fatty acids, vitamin D and dietary fiber, with a focus on the molecular mechanisms in the context of prevention and even treatment. In addition, several bioactive dietary components that have the ability to re-sensitize treatment resistant cells are described.