Resistin in Human Colorectal Cancer: Increased Expression Independently of Resistin Promoter −420C > G genotype

Serum resistin and the risk for hepatocellular carcinoma in diabetic patients

Hepatocellular carcinoma (HCC), the predominant type of liver cancer, is a major contributor to cancer-related fatalities across the globe. Diabetes has been identified as a significant risk factor for HCC, with recent research indicating that the hormone resistin could be involved in the onset and advancement of HCC in diabetic individuals. Resistin is a hormone that is known to be involved in inflammation and insulin resistance. Patients with HCC have been observed to exhibit increased resistin levels, which could be correlated with more severe disease stages and unfavourable prognoses. Nevertheless, the exact processes through which resistin influences the development and progression of HCC in diabetic patients remain unclear. This article aims to examine the existing literature on the possible use of resistin levels as a biomarker for HCC development and monitoring. Furthermore, it reviews the possible pathways of HCC initiation due to elevated resistin and offers new perspectives on comprehending the fundamental mechanisms of HCC in diabetic patients. Gaining a better understanding of these processes may yield valuable insights into HCC’s development and progression, as well as identify possible avenues for prevention and therapy.

Pre-Diagnostic Circulating Resistin Concentrations Are Not Associated with Colorectal Cancer Risk in the European Prospective Investigation into Cancer and Nutrition Study

Resistin is a polypeptide implicated in inflammatory processes, and as such could be linked to colorectal carcinogenesis. In case-control studies, higher resistin levels have been found in colorectal cancer (CRC) patients compared to healthy individuals. However, evidence for the association between pre-diagnostic resistin and CRC risk is scarce. We investigated pre-diagnostic resistin concentrations and CRC risk within the European Prospective Investigation into Cancer and Nutrition using a nested case-control study among 1293 incident CRC-diagnosed cases and 1293 incidence density-matched controls. Conditional logistic regression models controlled for matching factors (age, sex, study center, fasting status, and women-related factors in women) and potential confounders (education, dietary and lifestyle factors, body mass index (BMI), BMI-adjusted waist circumference residuals) were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for CRC. Higher circulating resistin concentrations were not associated with CRC (RR per doubling resistin, 1.11; 95% CI 0.94-1.30; p = 0.22). There were also no associations with CRC subgroups defined by tumor subsite or sex. However, resistin was marginally associated with a higher CRC risk among participants followed-up maximally two years, but not among those followed-up after more than two years. We observed no substantial correlation between baseline circulating resistin concentrations and adiposity measures (BMI, waist circumference), adipokines (adiponectin, leptin), or metabolic and inflammatory biomarkers (C-reactive protein, C-peptide, high-density lipoprotein cholesterol, reactive oxygen metabolites) among controls. In this large-scale prospective cohort, there was little evidence of an association between baseline circulating resistin concentrations and CRC risk in European men and women.

The first combined meta‐analytic approach for elucidating the relationship of circulating resistin levels and RETN gene polymorphisms with colorectal and breast cancer

Background

Evidence suggests that circulating resistin levels are altered in colorectal cancer (CRC) and breast cancer (BC). Again, polymorphisms in resistin-encoding gene RETN have been evaluated in CRC and BC. However, there is a scarcity of data establishing the relationship of resistin and RETN polymorphisms (rs1862513 and rs3745367) with these cancers. This study aimed to analyze the relationship of resistin levels and RETN polymorphisms with CRC and BC in a combined meta-analytic approach.

Main body of the abstract

After a comprehensive online literature search, screening and eligibility check, 41 articles (31 with resistin level and 10 with RETN polymorphisms) were retrieved for meta-analyses. The mean difference (MD) of resistin was calculated and pooled to investigate the effect sizes with a 95% confidence interval (CI), and the connection of genetic polymorphisms was analyzed with an odds ratio (OR) and 95% CI. The analysis showed that resistin level is significantly higher in CRC (MD = 3.39) and BC (MD = 3.91) patients. Subgroup analysis in CRC showed significantly higher resistin in serum (MD = 4.61) and plasma (MD = 0.34), and in BC, a significantly elevated resistin level was reported in premenopausal (MD = 7.82) and postmenopausal (MD = 0.37) patients. Again, RETN rs1862513 showed a significantly strong association with CRC (codominant 1—OR 1.24, codominant 2—OR 1.31, dominant model—OR 1.25, and allele model—OR 1.16) and with BC (codominant 2—OR 1.51, codominant 3—OR 1.51, recessive model—OR 1.51, and allele model—OR 1.21). RETN rs3745367 did not show any association with these cancers.

Short conclusion

Overall, our analysis indicates that higher circulating resistin levels are associated with an elevated risk of CRC and premenopausal and postmenopausal BC. Besides, rs1862513 in RETN gene is significantly connected with both CRC and BC.

Insulin Resistance and Colorectal Cancer Risk: the Role of Elevated Plasma Resistin Levels

PURPOSE

Given the important role of resistin in insulin resistance (IR) and obesity, as well as the associations between both IR and obesity and increased risk of colorectal cancer (CRC), we investigated whether plasma resistin levels were associated with CRC risk. Furthermore, the possible correlations between resistin and insulin, IR, and obesity in patients with CRC and controls were explored.

METHODS

This study was conducted as a case-control study and 170 subjects, including 88 controls and 82 cases with CRC, were enrolled and their plasma levels of glucoe, insulin, and resistin were measured using glucose oxidase or ELISA methods. Moreover, IR was calculated according to HOMA-IR index.

RESULTS

The cases with CRC had a higher HOMA-IR than the controls (1.8 ± 0.4 versus 1.4 ± 0.3, P < 0.001). Additionally, after the stratification of the cases with CRC by tumor site, higher levels of resistin and insulin, and a higher HOMA-IR in the cases with rectal cancer than in the controls were observed (resistin 5.9 ± 1.2 versus 5.4 ± 1.3, P = 0.043; insulin 5.9 ± 1.2 versus 5.4 ± 1.3, P = 0.039; HOMA- IR 1.9 ± 0.4 versus 1.3 ± 0.3, P < 0.001). Furthermore, resistin was positively correlated with insulin in the controls (r = 0.737, P < 0.001), the cases with CRC (r = 0.881, P < 0.001), the cases with colon cancer (r = 0.811, P < 0.001), and the cases with rectal cancer (r = 0.990, P < 0.001). All these differences remained significant after adjustment for confounding factors.

CONCLUSIONS

The findings of the present study reinforce the hypothesis that higher plasma levels of resistin in connection with insulin resistance play a role in susceptibility to colorectal, notably rectal, cancer. Nevertheless, further studies with bigger sample sizes are required to validate these findings.

High Expression of Both Resistin and Fascin-1 Predicts a Poor Prognosis in Patients with Colorectal Cancer

Emerging evidence indicates that resistin and fascin-1 may possess a causal role in the development of several types of cancers. However, the clinical significance of resistin expression in colorectal cancer (CRC) tissues is unclear, and there are no reports of any correlation between resistin and fascin-1. Our analyses explored the expression of resistin in CRC tissue and analyzed the clinical and prognostic significance of the observed positive correlation between resistin and fascin-1. The rate of strongly positive resistin expression (27.5%) was significantly higher in CRC tissues than in normal colorectal tissues (5.2%). Strongly positive resistin expression is related to multiple poor prognostic factors in CRC, including depth of tumor invasion, lymph node metastasis, and tumor stage. In this study, survival was worse in CRC patients with high levels of both resistin and fascin-1 expression than in those with high levels of only one protein or normal levels of both proteins. We suggest that a combined high level of resistin and fascin-1 expression correlates reliably with survival in CRC, so it may serve as a potential therapeutic target.

Association of Adipokines and Insulin, Which Have a Role in Obesity, with Colorectal Cancer

Obesity-related diseases are an important part of public health; and obesity is related with colorectal cancer. Adipocyte hypertrophy and visceral adipose tissue accumulation can cause adipocitis-related diseases and pathogenic adipocyte formation. Adipose tissue has a very important and active role in immune response formation. Cytokines/adipokines, which are secreted from adipose tissue, have an active role in communication between adipocytes and macrophages. Thus, visceral adipocyte is related with low-grade chronic systemic inflammation. Adipocytes have an important role in colorectal cancer pathogenesis because of proinflammatory cytokines, growth factors, and hormones secretion. Most highlighted cytokines are adiponectin, resistin, and ghrelin. Also, insulin resistance, glucose intolerance, increased plasma insulin levels, body mass index, insulin-like growth factor (IGF-1), glucose, and serum free fatty acids levels are considered to be related with colorectal cancer pathogenesis. Thus, in this review, we focus on the role of adipokines and insulin in colorectal cancer.

Association between rs1862513 and rs3745367 Genetic Polymorphisms of Resistin and Risk of Cancer: A Meta-Analysis

The present study aimed to assess any associations between resistin gene (RETN) polymorphisms and cancer susceptibility by conducting a meta-analysis. A comprehensive literature search was performed with PubMed, Web of Science, Scopus and Google Scholar for relevant studies published before April 2018. For the rs1862513 polymorphism, data from 9 studies covering 1,951 cancer patients and 2,295 healthy controls were included in this meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Our meta-analysis revealed that this RETN polymorphism significantly increased the risk of cancer in codominant (OR=1.23, 95% CI= 1.01-1.50, p=0.04, CG vs CC; and OR=1.25, 95% CI= 1.03-1.53, p=0.03, GG vs CC), dominant (OR=1.19, 95% CI= 1.05-1.35, p=0.006, CG+GG vs CC), and allele (OR=1.14, 95% CI= 1.00-1.30, p=0.04, G vs C) inheritance genetic models. Stratification analysis by cancer type revealed that the rs1862513 variant significantly increased the risk of colorectal and breast cancer, and that cancer overall in Caucasians (OR=1.22, 95% CI= 1.04-1.43, p=0.02, CG+GG vs CC; OR=1.18, 95% CI= 1.04-1.34, p=0.01, G vs C). The data revealed no correlation between the rs3745367 polymorphism and cancer risk. Further well-designed studies with larger sample sizes and different ethnicities are warranted to validate the present findings.

Resistin effects on pancreatic cancer progression and chemoresistance are mediated through its receptors CAP1 and TLR4

Resistin, secreted by macrophages in tumor microenvironment, has never been investigated in pancreatic cancer models, despite a vibrant tumor microenvironment around pancreatic tumors. We evaluated serum resistin levels in healthy individuals versus pancreatic cancer patients representing different tumor grades. In vitro mechanistic analysis involved MiaPaCa-2 and SW1990 cells. Resistin signaling depends on binding of resistin to its cognitive receptors. Therefore, we silenced adenylyl cyclase-associated protein 1 (CAP1) and toll-like receptor 4 (TLR4), its two known receptors, individually as well as in combination, by short hairpin RNA (shRNA). Effect of resistin on cell proliferation, migration, invasion, cell cycle, and sensitivity to gemcitabine was studied without or with silencing of resistin receptors CAP1 and/or TLR4. The results were also confirmed in vivo in mice xenografted with MiaPaCa-2 cells without or with receptor silencing. We report high resistin levels in pancreatic cancer patients which correlate positively with tumor grades. We observed a marked reduction in the resistin-induced proliferation, migration, invasion, and cell cycle of pancreatic cancer cells MiaPaCa-2 and SW1990 when the receptors were silenced. The results were confirmed in vivo wherein resistin effects were significantly attenuated in MiaPaCa-2 xenografts with silenced receptors. The combined silencing of CAP1 and TLR4 was found to be most effective in vitro and in vivo. We found activation of STAT3 by resistin in vivo and in vitro which was dependent on the presence of CAP1 and TLR4. Further, resistin was found to induce resistance to gemcitabine through its receptors. Our results describe novel functional roles of resistin with implications toward a better understanding of pancreatic tumor microenvironment.

Increased resistin suggests poor prognosis and promotes development of lung adenocarcinoma

Resistin is considered to be a risk factor for several types of cancer, but its functions are controversial and not well studied in lung cancer. The present study is aimed to investigate the expression of resistin in lung adenocarcinoma tissues, in order to evaluate its association with the clinicopathological characteristics of cancer patients and to investigate the effects of resistin in lung adenocarcinoma cells. A total of 70 pairs of lung adenocarcinoma tissues and normal tissues were collected and immunohistochemistry was performed to examine resistin expression. Resistin overexpressed cells were established by plasmid transfection in A549 or H1975 cells. Alterations in cell proliferation, apoptosis, migration and invasion were analyzed in vitro. A nude mouse tumorigenicity assay was used to test the effect of resistin in vivo. High expression of resistin was predominantly observed in lung adenocarcinoma tissues but not in adjacent normal lung tissues. Resistin expression was significantly associated with increased tumor size, clinical stage as well as lymph node metastasis while negatively associated with progression-free survival (PFS) and overall survival (OS). Expression of resistin was an independent risk factor for PFS and OS. Overexpression of resistin promoted significant proliferation, migration and invasion, while also inhibited apoptosis in vitro. Resistin also promoted tumor formation in nude mice. The potential molecular mechanism was also investigated by in vitro experiments. In conclusion, the present study revealed that a high level of resistin expression in lung adenocarcinoma tissues is associated with poor clinicopathological status and survival. Resistin, which promotes the development of lung adenocarcinoma in vitro and in vivo may be a novel target for lung adenocarcinoma.

Circulating Resistin Levels and Risk of Colorectal Cancer: A Meta-Analysis

Objectives. Published data on resistin levels in patients with colorectal cancer (CRC) were conflicting and heterogeneous. We conducted a meta-analysis of observational studies to examine the association of circulating resistin levels with carcinogenesis of the CRC. Methods. Potentially eligible studies published up to November 2015 were searched through MEDLINE, EMBASE, Science Citation Index Expanded database, CNKI, and WanFang database. The pooled weighted mean differences (WMDs) with 95% confidence intervals (CIs) calculated by fixed- or random-effect model were used to estimate the effects. Results. A total of 11 studies involving 965 patients were admitted in our meta-analysis. The pooled effects indicated that resistin levels were higher in CRC patients compared to healthy controls (WMD: 1.47 ng/mL; 95% CI: 0.78 to 2.16), with significant heterogeneity across the studies (I² = 72%, p < 0.0001). Subgroup analyses and sensitivity analyses revealed that study quality, design, sample type, and resistin assays may account for this heterogeneity. No publication bias was observed. Conclusions. Our meta-analysis suggests that increased circulating resistin levels are associated with greater risk of colorectal cancer. Given the limited number of available studies and significant heterogeneity, larger well-designed randomized studies are warranted.

Gly972Arg variant of insulin receptor substrate 1 gene and colorectal cancer risk in overweight/obese subjects

BACKGROUND

Given the major role of obesity and insulin resistance (IR) in colorectal cancer (CRC), we investigated whether genetic variants in ghrelin (GHRL), resistin (RETN) and insulin receptor substrate 1 (IRS1) were associated with CRC risk.

METHODS

This study was conducted as a case-control study, and 750 subjects, including 438 controls and 312 patients with CRC, were enrolled and genotyped using the PCR-RFLP method.

RESULTS

No significant differences were observed for GHRL (rs696217), RETN (rs3745367) and IRS1 (rs1801278, Gly972Arg or G972R) gene variants between the cases and controls. However, the IRS1 G972R R allele compared with the G allele and the G972R RR+GR genotype compared with the GG genotype appeared to be markers of decreased CRC susceptibility in the overweight/obese subjects (p = 0.024; odds ratio [OR] = 0.42, 95% confidence interval [95% CI], 0.20-0.91; and p = 0.048; OR = 0.42, 95% CI, 0.17-0.99, respectively). Furthermore, the R allele and RR+GR genotype were also associated with decreased risks for obesity in the patients with CRC (p = 0.007; OR = 0.35, 95% CI, 0.15-0.77; and p = 0.015; OR = 0.35, 95% CI, 0.15-0.72, respectively).

CONCLUSIONS

In accordance with previous studies, our findings suggest that the IRS1 G972R R allele and RR+GR genotype have protective effects for CRC in overweight/obese patients and for obesity in patients with CRC. Nevertheless, further studies are required to confirm these findings.

Resistin -420C>G promoter variant and colorectal cancer risk

PURPOSES

Obesity is associated with an increased risk of colorectal cancer (CRC), and ghrelin (GHRL) and resistin (RETN) are thought to be related to obesity. Our aim was to investigate whether GHRL and RETN gene variants are associated with CRC risk.

MATERIALS AND METHODS

All 414 subjects, including 197 cases with CRC and 217 controls, were genotyped for the GHRL (rs26802) and RETN (rs1862513) or -420 C>G gene variants using the PCR-RFLP method.

RESULTS

Our findings indicated that the RETN -420 C>G "CC" genotype, compared with the "GG" and "GC" genotypes, was a marker of decreased CRC susceptibility; the difference remained significant after adjustment for age, BMI, gender, smoking status, NSAID use, and family history of CRC (p=0.020; OR=0.52, 95% CI=0.30-0.90). Furthermore, after adjustment for confounding factors, the -420 C>G "CC" genotype, compared with the "GG" genotype, was associated with a decreased risk for CRC (p=0.044; OR=0.53, 95% CI=0.29-0.98). In addition, no significant difference was observed for the GHRL (rs26802) gene variant.

CONCLUSIONS

To our knowledge, this is the first study suggesting that the RETN -420 C>G "CC" genotype is a marker of decreased CRC susceptibility. This observation is relevant from a scientific perspective and deserves further investigations.

Polymorphisms in RETN gene and susceptibility to colon cancer in Saudi patients

BACKGROUND AND OBJECTIVES

Resistin is an adipocytokine, which has been studied for its role in insulin resistance and recently in inflammation. Several single-nucleotide polymorphisms (SNPs) have been identified in the human resistin gene (RETN). This study aims to investigate the association of RETN rs1862513 (C-420G) and rs3745367 (G+299A) SNPs with the colon cancer risk in Saudi patients.

DESIGN AND SETTING

This is a case-control study conducted among Saudi adult colon cancer patients recruited from King Abdulaziz Hospital and Oncology Center in Jeddah, Saudi Arabia.

SUBJECTS AND METHODS

In this study, 120 Saudi volunteers (60 colon cancer patients and 60 disease-free controls) were studied. The SNPs were determined by polymerase chain reaction (PCR) and genotyping using PCR- restriction fragment length polymorphism analysis.

RESULTS

In comparing the result obtained for the patient group with that of the controls, colon cancer group displayed different genotype distribution of the RETN C-420G and G+299A SNPs. The study indicated that the SNP-420 heterozygous (CG) genotype (odds ratio [OR]=2.48, 95% CI 1.07-5.74, P=.03) and the SNP +299 heterozygous (GA) genotype (OR=6.5, 95% CI 1.77-24.18, P=.002) significantly increased the risk of colon cancer. A further analysis of the genotype combination of SNPs RETN C-420G and G+299A showed a larger increase in the colon cancer risk.

CONCLUSION

These preliminary results suggested a potential role for RETN C-420G and G+299A polymorphisms in the genetic predisposition to colon cancer disease.

Increased resistin in brain dead organ donors is associated with delayed graft function after kidney transplantation

INTRODUCTION

Resistin increases during several inflammatory diseases and after intracerebral bleeding or head trauma. Resistin activates the endothelium and may initiate an inflammatory response. No data are available on resistin in brain dead donors (DBD) that regularly manifest a pronounced inflammatory state.

METHODS

We analyzed plasma resistin in 63 DBDs and correlated results with donor variables and the postoperative course following kidney transplantation using organs from these donors. Endocan and monocyte chemotactic protein (MCP)-1 were also studied. Twenty-six live kidney donors (LD) and the corresponding kidney transplantations were used as controls.

RESULTS

DBDs had higher resistin (median/range 30.75 ng/ml, 5.41-173.6) than LD (7.71 ng/ml, 2.41-15.74, p < 0.0001). Resistin in DBD correlated with delayed graft function (DGF) in the kidney recipients (r = 0.321, p < 0.01); receiver operating characteristic curve revealed an area under the curve of 0.765 (95% confidence interval [CI] 0.648-0.881, p < 0.01) and a cut-off value for resistin of 25 ng/ml; MCP-1 and endocan were higher in DBDs (p < 0.0001) but did not correlate with DGF or acute rejection. No relationship was found between the studied molecules and the postoperative course of LD kidney transplants.

CONCLUSIONS

High resistin levels in the DBD before organ retrieval are associated with DGF after kidney transplantation. The resistin increase seems related to the inflammatory state after brain death but not to the cause of death.

Genetic variation in adipokine genes and risk of colorectal cancer

OBJECTIVE

Obesity has been related to an increased risk of colorectal cancer (CRC). Adipokines produced by the adipose tissue are directly linked to obesity and may thus contribute to the pathogenesis of CRC. We hypothesized that potentially functional polymorphisms in the adipokine genes leptin (LEP), leptin receptor (LEPR), resistin (RETN), and adiponectin (ADIPOQ) may be associated with CRC.

DESIGN AND METHODS

We studied the association of four putatively functional single nucleotide polymorphisms (SNPs) with CRC risk using a hospital-based study design with 702 cases and 752 controls from the Czech Republic. We used likelihood ratio tests to select the best model to represent the relationship between genotypes and risk of CRC. Age-adjusted odds ratios (ORs) under the best model were calculated for each SNP. Previous genotyping data on insulin (INS)-related genes were used to explore interactions between genes in obesity- and diabetes-related pathways by using two independent methods, logistic regression, and multifactor-dimensionality reduction.

RESULTS

A trend to associate between the RETN SNP rs1862513 (C-420G) and CRC risk was observed (per allele OR 1.18, 95% confidence interval (0.99-1.40). Statistically, significant interactions were observed between the INS SNP rs3842754 (+1127INSPstI) genotypes and both the LEPR SNP rs1137101 (Q223R) and the ADIPOQ SNP rs266729 (C-11374G) genotypes.

CONCLUSIONS

Our results suggest that variants in the adipokine genes may affect CRC risk in combination with variants in diabetes-related genes.