Lack of significant association between serum inflammatory cytokine profiles and the presence of colorectal adenoma

Plasma protein changes reflect colorectal cancer development and associated inflammation

Introduction

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of death worldwide. Efficient non-invasive blood-based biomarkers for CRC early detection and prognosis are urgently needed.

Methods

To identify novel potential plasma biomarkers, we applied a proximity extension assay (PEA), an antibody-based proteomics strategy to quantify the abundance of plasma proteins in CRC development and cancer-associated inflammation from few μL of plasma sample.

Results

Among the 690 quantified proteins, levels of 202 plasma proteins were significantly changed in CRC patients compared to age-and-sex-matched healthy subjects. We identified novel protein changes involved in Th17 activity, oncogenic pathways, and cancer-related inflammation with potential implications in the CRC diagnosis. Moreover, the interferon γ (IFNG), interleukin (IL) 32, and IL17C were identified as associated with the early stages of CRC, whereas lysophosphatidic acid phosphatase type 6 (ACP6), Fms-related tyrosine kinase 4 (FLT4), and MANSC domain-containing protein 1 (MANSC1) were correlated with the late-stages of CRC.

Discussion

Further study to characterize the newly identified plasma protein changes from larger cohorts will facilitate the identification of potential novel diagnostic, prognostic biomarkers for CRC.

The Significance of Selected C-C Motif Chemokine Ligands in Colorectal Cancer Patients

Colorectal cancer (CRC) is one of the most frequently diagnosed neoplasms. Despite the advances in diagnostic tools and treatments, the number of CRC cases is increasing. Therefore, it is vital to search for new parameters that could be useful in its diagnosis. Thus, we wanted to assess the usefulness of selected CC chemokines (CCL2, CCL4, and CCL15) in CRC. The study included 115 subjects (75 CRC patients and 40 healthy volunteers). The serum concentrations of all parameters were measured using a multiplexing method (Luminex). The CRP levels were determined by immunoturbidimetry, and the classical tumor markers (CEA and CA 19-9) were measured using CMIA (chemiluminescent microparticle immunoassay). The concentrations of all parameters were higher in the CRC group when compared to the healthy controls. The diagnostic sensitivity, specificity, positive and negative predictive value, and area under the ROC curve (AUC) of all estimated CC chemokines were higher than those of CA 19-9. Interestingly, the obtained results also suggest CCL2's significance in the determination of local metastases and CCL4's significance in the determination of distant metastases. However, further studies concerning the role of selected CC chemokines in the course of colorectal cancer are necessary to confirm and to fully clarify their diagnostic utility and their clinical application as markers of CRC development.

Circulating inflammation markers and colorectal adenoma risk

Inflammation is a driver of colorectal neoplasia; however, what particular inflammatory processes play a role in early carcinogenesis are unclear. We compared serum levels of 78 inflammation markers between 171 pathologically confirmed colorectal adenoma cases (including 48 incident cases) and 344 controls within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. We used weighted multivariable logistic regression to compute odds ratio (OR) and 95% confidence interval (CI). We found 14 markers associated with risk of adenoma overall; three of these were also associated with incident adenoma: CC-chemokine cysteine motif chemokine ligand 20 (CCL20) [overall adenoma fourth versus first quartile: OR 4.8, 95% CI 2.0-12, Ptrend 0.0007; incident adenoma third versus first tertile: OR 4.6, 95% CI 1.0-22, Ptrend 0.03], growth-related gene oncogene products (GRO) [OR 3.8, 95% CI 1.6-9.3, Ptrend 0.006 and OR 3.6, 95% CI 1.1-12, Ptrend 0.04, respectively] and insulin [OR 2.9, 95% CI 0.8-10, Ptrend 0.05 and OR 7.8, 95% CI 1.3-46, Ptrend 0.03, respectively]. All statistical tests were two-sided. These results provide important new evidence implicating CCL20- and GRO-related pathways in early colorectal carcinogenesis and further support a role for insulin.

Colorectal Adenomas-Genetics and Searching for New Molecular Screening Biomarkers

Colorectal cancer (CRC) is a malignant disease with an incidence of over 1.8 million new cases per year worldwide. CRC outcome is closely related to the respective stage of CRC and is more favorable at less advanced stages. Detection of early colorectal adenomas is the key to survival. In spite of implemented screening programs showing efficiency in the detection of early precancerous lesions and CRC in asymptomatic patients, a significant number of patients are still diagnosed in advanced stages. Research on CRC accomplished during the last decade has improved our understanding of the etiology and development of colorectal adenomas and revealed weaknesses in the general approach to their detection and elimination. Recent studies seek to find a reliable non-invasive biomarker detectable even in the blood. New candidate biomarkers could be selected on the basis of so-called liquid biopsy, such as long non-coding RNA, microRNA, circulating cell-free DNA, circulating tumor cells, and inflammatory factors released from the adenoma into circulation. In this work, we focused on both genetic and epigenetic changes associated with the development of colorectal adenomas into colorectal carcinoma and we also discuss new possible biomarkers that are detectable even in adenomas prior to cancer development.

Immune battle at the premalignant stage of colorectal cancer: focus on immune cell compositions, functions and cytokine products

It is now widely accepted that most human cancers, including colorectal cancers (CRCs), develop from premalignant lesions through a long-term multistep process. Host immunity is a key determinant that maintains most premalignant lesions in a stable state via immunosurveillance. However, premalignant cells use diverse strategies to escape host immunosurveillance. A switch in the immune function from immunosurveillance to immunosuppression facilitates the progression of premalignant lesions to established CRCs. This review summarizes the recent progress in understanding alterations in the immune landscape, including immune cell compositions, functions and cytokine products, in the premalignant stage of CRC and provides an updated discussion on its translational significance along the colorectal adenoma-carcinoma sequence.

Incremental Elevations in TNFα and IL6 in the Human Colon and Procancerous Changes in the Mucosal Transcriptome Accompany Adiposity

BACKGROUND

Obesity, a risk factor for colorectal cancer, raises systemic levels of proinflammatory mediators. Whether increased levels also reside in the colons of obese individuals and are accompanied by procancerous alterations in the mucosal transcriptome is unknown.

METHODS

Concentrations of TNFα, IL1β, and IL6 in blood and colonic mucosa of 16 lean and 26 obese individuals were examined. Differences in the mucosal transcriptome between the two groups were defined.

RESULTS

Plasma IL6 and TNFα were 1.4- to 3-fold elevated in obese subjects [body mass index (BMI) ≥ 34 kg/m²] compared with the lean controls (P < 0.01). Among individuals with BMI ≥ 34 kg/m² colonic concentrations of IL6 and TNFα were 2- to 3-fold greater than in lean subjects (P < 0.03). In a general linear model, adjusted for NSAID use, colonic IL6 (partial r = 0.41; P < 0.01) and TNFα (partial r = 0.41; P = 0.01) increased incrementally over the entire range of BMIs (18.1-45.7). Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with a reduction in colonic IL6 (β = -0.65, P < 0.02). RNA sequencing (NSAID users excluded) identified 182 genes expressed differentially between lean and obese subjects. The two gene networks most strongly linked to changes in expression included several differentially expressed genes known to regulate the procarcinogenic signaling pathways, NFκB and ERK 1/2, in a pattern consistent with upregulation of each in the obese subjects.

CONCLUSIONS

Incremental increases in two major proinflammatory colonic cytokines are associated with increasing BMI, and in the obese state are accompanied by procancerous changes in the transcriptome.

IMPACT

These observations delineate means by which an inflammatory milieu may contribute to obesity-promoted colon cancer.

Polymorphisms in genes related to inflammation and obesity and colorectal adenoma risk

We previously investigated the association between single nucleotide polymorphisms (SNPs) in genes related to obesity and inflammation and colorectal cancer in the CLUE II cohort. However, the relationships between these SNPs and colorectal adenomas have not been well evaluated. In a nested case-control study of 135 incident adenoma cases and 269 matched controls in the CLUE II cohort (1989-2000), we genotyped 17 candidate SNPs in 12 genes (PPARG, TCF7L2, ADIPOQ, LEP, IL10, CRP, TLR4, IL6, IL1B, IL8, TNF, RNASEL) and 19 tagSNPs in three genes (IL10, CRP, and TLR4). Conditional logistic regression was used to calculate odds ratios (OR) for adenomas (overall and by size, histology, location, number). Polymorphisms in the inflammatory-related genes CRP, ADIPOQ, IL6, and TLR4 were observed to be associated with adenoma risk. At rs1205 in CRP, T (minor allele) carriers had a higher risk (OR 1.67, 95%CI 1.07-2.60; reference: CC) of adenomas overall and adenomas with aggressive characteristics. At rs1201299 in ADIPOQ, the AC genotype had a higher risk (OR 1.58, 95%CI 1.00-2.49) of adenomas, while the minor AA genotype had a borderline inverse association (OR 0.44, 95%CI 0.18-1.08; reference: CC). At rs1800797 in IL6, the AA genotype had a borderline inverse association (OR 0.53, 95%CI 0.27-1.05; reference: GG). Three TLR4 tagSNPs (rs10116253, rs1927911, rs7873784) were associated with adenomas among obese participants. None of these SNPs were associated with colorectal cancer in our prior study in CLUE II, possibly suggesting a different genetic etiology for early colorectal neoplasia.

Profiling of cytokines, chemokines and other soluble proteins as a potential biomarker in colorectal cancer and polyps

Soluble proteins including cytokines, chemokines and growth factors are small proteins that mediate and regulate immunity. They involved in the pathogenesis of many diseases including cancers. The concentration of these proteins in biological fluids (serum or plasma) and tissues in diseases may suggest pathway activation that leads to inflammatory response or disease progression. Therefore, these soluble proteins may be useful as a tool for screening, diagnosis classification between stages of disease or surveillance for therapy. Enzyme-linked immunosorbent assays (ELISA) and bioassay have been used as a gold standard in cytokine level measurements in clinical practice. However, these methods allow only single cytokine detection at a time and ineffective for screening purposes. Hence, the innovation of multiplexing technology allows measurement of many these soluble proteins simultaneously, thus allowing rapid, cost effective and better efficiency by using a minute amount of sample. In this study, we explored the profiles of key inflammatory cytokines, chemokines and other soluble proteins from the serum derived from colorectal carcinoma (CRC, n=20), colorectal polyps (P, n=20) and healthy volunteers (N, n=20) using multiplexed bead-based immunoassays. We aimed to evaluate if the levels of these soluble proteins can classify these groups of populations and explore the possible application of the soluble proteins as biomarkers in early stage screening and/or surveillance. We observed significant high IL-4, MIP-1β, FasL and TGF-β1 levels but lower levels for RANTES in P-derived serum as compared to N-derived serum. Significant high IL-8, VEGF, MIP-1β, Eotaxin and G-CSF observed in CRC-derived serum when compared to N-derived serum. Between CRC- and P-derived serum, significantly higher levels of IL-8, Eotaxin and G-CSF but lower levels for TGF-β1 were detected in CRC-derived serum. These preliminary results were obtained from small sample size and could be further validated with larger sample size cohort to produce a panel of biomarkers for CRC and P patients. Our findings might be useful in developing a disease-specific panel for biomarker screening assay. This could be used for early diagnosis and/or treatment surveillance.

Non-alcoholic fatty liver disease connections with fat-free tissues: A focus on bone and skeletal muscle

The estimates of global incidence and prevalence of non-alcoholic fatty liver disease (NAFLD) are worrisome, due to the parallel burden of obesity and its metabolic complications. Indeed, excess adiposity and insulin resistance represent two of the major risk factors for NAFLD; interestingly, in the last years a growing body of evidence tended to support a novel mechanistic perspective, in which the liver is at the center of a complex interplay involving organs and systems, other than adipose tissue and glucose homeostasis. Bone and the skeletal muscle are fat- free tissues which appeared to be independently associated with NAFLD in several cross-sectional studies. The deterioration of bone mineral density and lean body mass, leading to osteoporosis and sarcopenia, respectively, are age-related processes. The prevalence of NAFLD also increases with age. Beyond physiological aging, the three conditions share some common underlying mechanisms, and their elucidations could be of paramount importance to design more effective treatment strategies for the management of NAFLD. In this review, we provide an overview on epidemiological data as well as on potential contributors to the connections of NAFLD with bone and skeletal muscle.

Markers of systemic inflammation and colorectal adenoma risk: Meta-analysis of observational studies

AIM

To perform a meta-analysis of observational studies on inflammatory markers levels and occurrence of colorectal adenoma.

METHODS

PubMed and EMBASE databases were searched until March 2016 for the articles reporting on the circulating levels of inflammatory markers, including: C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) and risk of colorectal adenoma. Random-effects models were used to calculate summary odds ratios (ORs) with 95%CIs for the highest vs lowest category of exposure. Heterogeneity was assessed by using the Q test and I² statistic. Subgroup analyses were also performed to test for potential source of heterogeneity.

RESULTS

A total of 14 case-control studies were included. Ten studies on CRP including a total of 3350 cases and 4168 controls showed non-significant summary (OR = 1.23, 95%CI: 0.98-1.54; I² = 54%, P_{heterogeneity} = 0.01) in the general analysis, but significant increased odds when considering only advanced adenoma (OR = 1.59, 95%CI: 1.09-2.32; I² = 44%, P_{heterogeneity} = 0.15). Subgroup and stratified analyses revealed a potential influence of smoking status and aspirin use on the association between CRP levels and colorectal adenoma. Five studies examined the association between circulating levels of TNF-α and colorectal adenoma risk, including a total of 1,568 cases and 2,832 controls. The summary OR for the highest vs the lowest category of exposure was 1.00 (95%CI: 0.77-1.29). The relationship between circulating IL-6 levels and colorectal adenoma risk was investigated in 7 studies including a total of 1936 cases and 3611 controls. The summary OR for the highest vs the lowest category of exposure was 1.19 (95%CI: 0.92-1.55).

CONCLUSION

Summary of current evidence suggests a positive association of CRP levels and advanced colorectal adenoma risk. The role of potential confounding factors should be further evaluated.

Dietary Inflammatory Index and Risk of Colorectal Adenoma Recurrence: A Pooled Analysis

No studies have evaluated the association between the dietary inflammatory index (DII) and colorectal adenoma recurrence. DII scores were calculated from a baseline food frequency questionnaire. Participants (n = 1727) were 40-80 years of age, enrolled in two Phase III clinical trials, who had ≥1 colorectal adenoma(s) removed within 6 months of study registration, and a follow-up colonoscopy during the trial. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). No statistically significant associations were found between DII and odds of colorectal adenoma recurrence [ORs (95% CIs) = 0.93 (0.73, 1.18) and 0.95 (0.73, 1.22)] for subjects in the second and third DII tertiles, respectively, compared to those in the lowest tertile (P_trend = 0.72). No associations were found for recurrent colorectal adenoma characteristics, including advanced recurrent adenomas, large size, villous histology, or anatomic location. While our study did not support an association between a proinflammatory diet and colorectal adenoma recurrence, future studies are warranted to elucidate the role of a proinflammatory diet on the early stages of colorectal carcinogenesis.

Elevated systemic interleukin-7 in patients with colorectal cancer and individuals at high risk of cancer: association with lymph node involvement and tumor location in the right colon

Interleukin (IL)-7 is a cytokine essential for protective immunity, and it is considered as a promising agent for cancer immunotherapy. Recent studies, however, appear to associate IL-7 with aggressiveness of solid tumors. The IL-7 has been less studied in colorectal cancer (CRC) and conditions associated with increased risk of CRC development. To explore IL-7 status in bowel diseases, it was measured immunofluorometrically in 431 individuals (110 with CRC) by using Luminex platform. A level of IL-7 in CRC patients was significantly higher than in controls, did not differ from those with adenomas, but was lower than in both active and inactive inflammatory bowel disease (IBD) cases. In CRC, IL-7 was higher in patients with lymph node and distant metastases and with tumors located in right colon. In adenomas, IL-7 elevation was associated exclusively with villous growth pattern, while in IBD, circulating IL-7 reflected clinical activity of Crohn’s disease and ulcerative colitis. Systemic TNFα, IL-10, and PDGF-BB were independent predictors of circulating IL-7. In summary, our study is the first to demonstrate IL-7 elevation in CRC in association with metastatic disease and tumor location. Both associations should be considered when designing IL-7-based immunotherapies for CRC. Further studies on IL-7 functionality in CRC are necessary.

Local and systemic Th17 immune response associated with advanced stage colon cancer

BACKGROUND

Little is known about how the immunologic microenvironment changes during tumor progression and metastatic spread. Recently, murine models have shown the T-helper 17 (Th17) pathway to play an important role in promoting colorectal cancer (CRC). The purpose of this study was to compare cytokine profiles in the tumor microenvironment of CRC between local disease (stages I/II) and advanced disease (stages III/IV), and to determine whether these changes were manifest in the systemic circulation of patients with advanced disease.

MATERIALS AND METHODS

Serum and tissue cytokine profiles were assayed among patients with documented adenocarcinoma before surgical resection at a single institution from September 2014 to February 2015. Using the Bio-Plex Pro Human Th17 Cytokine Assay Kit (Bio-Rad Laboratories), the concentrations of multiple cytokines were determined. Multiple logistic regression analyses were used to evaluate the association between TNM staging and cytokine levels.

RESULTS

A total of 33 patients with documented adenocarcinoma were included. None of the patients received neoadjuvant chemotherapy. American Joint Commission on Cancer TNM classification was used. Advanced disease was associated with elevated tumor levels of tumor necrosis factor-alpha, interleukin (IL)-4, IL-10, IL-17A, and IL-17F, and only stage IV showed elevated systemic levels of Th17-associated cytokines IL-17F, IL-23, and IL-25.

CONCLUSIONS

The Th17 pathway likely has important mechanistic implications in human CRC. Metastatic disease was associated with elevated Th17-associated cytokines both in colonic tissue and systemically. These changes in systemic expression of Th17-associated cytokines could establish novel pathways for CRC and warrant further investigation.

Circulating levels of C-reactive protein, interleukin-6 and tumor necrosis factor-α and risk of colorectal adenomas: a meta-analysis

Results from publications on inflammatory markers of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and risk of colorectal adenomas are not consistent. A meta-analysis was conducted to explore the above-mentioned associations. Relevant studies were identified by a search of Embase, Medline and PubMed through February 2016. A random effect model was adopted to combine study-specific odds ratio (OR) and 95% confidence interval (95% CI). Between-study heterogeneity and publications bias were assessed. Dose-response relationships were assessed by restricted cubic splines. Nineteen observational studies were included. For highest vs. lowest levels, results from this meta-analysis did not support an association between circulating levels of CRP [OR (95% CI): 1.15 (0.94-1.40)], IL-6 [1.17 (0.94-1.46)] and TNF-α [0.99 (0.75-1.31)] and risk of colorectal adenomas, respectively. The findings were supported by sensitivity analysis and subgroup analysis. In dose-response analysis, the risk of colorectal adenomas increased by 2% [1.02 (0.97-1.08)] for each 1 mg/L increment in circulation CRP levels, 9% [1.09 (0.91-1.31)] for each 1 ng/L increment in circulation IL-6 levels, and 6% [1.06 (0.93-1.21)] for each 1 pg/mL increment in circulation TNF-α levels. Moderate between-study heterogeneity was found. No evidence of publication bias was found. Circulation levels of CRP, IL-6 and TNF-α might be not useful biomarkers for identifying colorectal adenomas, respectively.

Diagnostic utility of VEGF and soluble CD40L levels in serum of Alzheimer's patients

BACKGROUND

Non-invasive blood-based biomarkers are eagerly awaited for the diagnosis of Alzheimer's disease (AD). The present study aimed to evaluate the individual and combined diagnostic value of soluble CD40 ligand (sCD40L) and vascular endothelial growth factor (VEGF) for AD.

METHODS

Fifty patients with AD and forty gender and age-matched control participants with standardized clinical assessments and neuroimaging measures were enrolled. VEGF and sCD40L were qualified in 90 subjects using immunomagnetic beads assay.

RESULTS

To evaluate the individual and combined diagnostic value of sCD40L and VEGF for AD, receiver operating characteristic curves were generated and logistic regression analysis was conducted. The AUCs (area under ROCs) of sCD40L and VEGF and their corresponding 95% confidence interval (CI) were 0.824 (95% CI: 0.737-0.910) and 0.731 (95% CI: 0.622-0.839), respectively. Combined ROC analysis based on these 2 biomarkers revealed an elevated AUC of 0.858 (95% CI: 0.775-0.941), which indicates an additive effect in the diagnostic value of these two biomarkers.

CONCLUSIONS

We identified the feasibility of a blood-based biomarker approach in AD diagnostics though the results warrant validation in large-scale studies. A combination of sCD40L and VEGF could be a useful diagnostic biomarker for future clinical trials with AD and may act as a suitable add-on biomarker to the panel of markers already existing for AD.