IGF1(CA)19 and IGFBP-3-202A/C Gene Polymorphism and Cancer Risk: A Meta-analysis

A systematic review and meta-analysis for the association of the insulin-like growth factor1 pathway genetic polymorphisms with colorectal cancer susceptibility

Background

The receptors, ligands, and associated proteins of the insulin-like growth factor (IGF) family are involved in cancer development. The IGF1 receptor and its accompanying signaling cascade are a crucial growth-regulatory mechanism that plays an important role in colorectal cancer (CRC) proliferation and differentiation. IRS1 (Insulin receptor substrate-1), a major substrate for the IGF1R, is involved in cell growth and promotes tumorigenesis. There are shreds of evidence from prior research suggesting that IGF system polymorphisms may influence susceptibility to CRC. However, the findings in this area were contradictory. Accordingly, we carried out a systematic literature search to identify all case-control, cross-sectional, and cohort studies on the association between various polymorphisms across four IGF1 pathway genes (IGF1, IGF1R, IRS1, and IRS2) and the risk of CRC.

Methods

We performed a comprehensive search strategy in PubMed, Scopus, and Web of Science databases for articles available until Aug 30, 2022. A total of 26 eligible studies with IGF1/IGF1R, IRS1 and IRS2 polymorphisms; met the inclusion criteria. All case-control studies for IGF1 rs6214C>T, IRS1 rs1801278G>A, and IRS2 rs1805097G>A comprising 22,084 cases and 29,212 controls were included in the current meta-analysis. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate relationships between the polymorphisms and CRC susceptibility. All statistical analyses were performed using STATA software version 14.0.

Results

The meta-analysis of available data for rs6214C>T, rs1801278G>A, and rs1805097G>A showed a significant association between these polymorphisms and an increased CRC risk in some of the comparisons studied (rs6214C>T, pooled OR for CC = 0.43, 95% CI 0.21- 0.87, P = 0.019; rs1801278G>A, OR for GA = 0.74, 95% CI 0.58-0.94, P = 0.016; rs1805097G>A, OR for GA = 0.83, 95% CI 0.71-0.96, P = 0.013). Nevertheless, the meta-analysis did not include other genetic variations in IGF1, IGF1R, IRS1, and IRS2 due to heterogeneity and limited sample size.

Conclusions

This systematic review and meta-analysis provide evidence that genetic variants in IGF1 rs6214C>T, IRS1 rs1801278G>A, and IRS2 rs1805097G>A are associated with an increased risk of CRC. These findings may contribute to a better understanding of the complex genetic mechanisms involved in CRC development and could inform future research on prevention and treatment strategies for this disease.

The effects of genetic variants related to insulin metabolism pathways and the interactions with lifestyles on colorectal cancer risk

OBJECTIVES

Genetic variants in metabolic signaling pathways may interact with lifestyle factors, such as dietary fatty acids, influencing postmenopausal colorectal cancer (CRC) risk, but these interrelated pathways are not fully understood.

METHODS

In this study, we examined 54 single-nucleotide polymorphisms (SNPs) in genes related to insulin-like growth factor-I/insulin traits and their signaling pathways and lifestyle factors in relation to postmenopausal CRC, using data from 6,539 postmenopausal women in the Women's Health Initiative Harmonized and Imputed Genome-Wide Association Studies. By employing a two-stage random survival forest analysis, we evaluated the SNPs and lifestyle factors by ranking them according to their predictive value and accuracy for CRC.

RESULTS

We identified four SNPs (IRS1 rs1801123, IRS1 rs1801278, AKT2 rs3730256, and AKT2 rs7247515) and two lifestyle factors (age and percentage calories from saturated fatty acids) as the top six most influential predictors for CRC risk. We further examined interactive effects of those factors on cancer risk. In the individual SNP analysis, no significant association was observed, but the combination of the four SNPs, age, and percentage calories from saturated fatty acid (≥11% per day) significantly increased the risk of CRC in a gene and lifestyle dose-dependent manner.

CONCLUSIONS

Our findings provide insight into gene-lifestyle interactions and will enable researchers to focus on individuals with risk genotypes to promote intervention strategies. Our study suggests the careful use of data on potential genetic targets in clinical trials for cancer prevention to reduce the risk for CRC in postmenopausal women.

Dairy Products: Is There an Impact on Promotion of Prostate Cancer? A Review of the Literature

This review of the literature aims to study potential associations between high consumption of milk and/or dairy products and prostate cancer (PC). Literature is scarce, yet there is a direct relationship between mTORC1 activation and PC; several ingredients in milk/dairy products, when in high concentrations, increase signaling of the mTORC1 pathway. However, there are no studies showing an unequivocal relationship between milk products PC initiation and/or progression. Three different reviews were conducted with articles published in the last 5 years: (M1) PC and intake of dairy products, taking into account the possible mTORC1signaling mechanism; (M2) Intake of milk products and incidence/promotion of PC; (M3) mTORC1 activation signaling pathway, levels of IGF-1 and PC; (M4) mTORC pathway and dairy products. Of the 32 reviews identified, only 21 met the inclusion criteria and were analyzed. There is little scientific evidence that directly link the three factors: incidence/promotion of PC, intake of dairy products and PC, and PC and increased mTORC1 signaling. Persistent hyper-activation of mTORC1 is associated with PC promotion. The activity of exosomal mRNA in cellular communication may lead to different impacts of different types of milk and whether or not mammalian milks will have their own characteristics within each species. Based on this review of the literature, it is possible to establish a relationship between the consumption of milk products and the progression of PC; we also found a possible association with PC initiation, hence it is likely that the intake of dairy products should be reduced or minimized in mens' diet.

Growth Hormone's Links to Cancer

Several components of the GH axis are involved in tumor progression, and GH-induced intracellular signaling has been strongly associated with breast cancer susceptibility in genome-wide association studies. In the general population, high IGF-I levels and low IGF-binding protein-3 levels within the normal range are associated with the development of common malignancies, and components of the GH-IGF signaling system exhibit correlations with clinical, histopathological, and therapeutic parameters in cancer patients. Despite promising findings in preclinical studies, anticancer therapies targeting the GH-IGF signaling system have led to disappointing results in clinical trials. There is substantial evidence for some degree of protection against tumor development in several animal models and in patients with genetic defects associated with GH deficiency or resistance. In contrast, the link between GH excess and cancer risk in acromegaly patients is much less clear, and cancer screening in acromegaly has been a highly controversial issue. Recent studies have shown that increased life expectancy in acromegaly patients who attain normal GH and IGF-I levels is associated with more deaths due to age-related cancers. Replacement GH therapy in GH deficiency hypopituitary adults and short children has been shown to be safe when no other risk factors for malignancy are present. Nevertheless, the use of GH in cancer survivors and in short children with RASopathies, chromosomal breakage syndromes, or DNA-repair disorders should be carefully evaluated owing to an increased risk of recurrence, primary cancer, or second neoplasia in these individuals.

The Role of Polymorphisms in Genes of PI3K/Akt Signaling Pathway on Prostate

Background and Objective: Increasing evidence suggested that polymorphisms in genes of PI3K/Akt pathway were closely related to prostate cancer (PCa) risk. Nevertheless, these results are controversial and inconclusive. Here, we conducted a comprehensive updated meta-analysis and systematic review to precisely illustrate the association between polymorphisms in genes of PI3K/Akt signaling pathway and PCa risk.

Materials and Methods: The gene set of PI3K/Akt pathway was referenced from the Kyoto Encyclopedia of Genes and Genomes (KEGG) website. Relevant studies were identified by the systematically researching on PubMed, Web of Science and Google Scholar databases up to October 1, 2017. The odds ratios (ORs) with a corresponding 95% confidential intervals (95%CIs) were applied to test their associations. All the analyses were conducted by using Stata 12.0 (Stata Corporation, USA).

Results: Finally, 38 articles comprising 62 case-control studies were enrolled for 13 polymorphisms in genes of PI3K/Akt pathway. However, overall results failed to present a positive association between polymorphisms in genes of PI3K/Akt pathway and PCa risk. Nevertheless, in the subgroup analysis by ethnicity, we identified that IL-6-rs1800795 polymorphism was associated with an increased risk of PCa for Caucasian individuals in dominant model (MM + MW vs. WW: OR = 1.245, 95%CI = 1.176-1.318, P < 0.001).

Conclusion: Our work suggests that polymorphisms in genes of PI3K/Akt Signaling Pathway are not risk factor for PCa. Further well-designed studies with larger samples and precise designs are demanded to corroborate our findings.

Genetic Variants in Metabolic Signaling Pathways and Their Interaction with Lifestyle Factors on Breast Cancer Risk: A Random Survival Forest Analysis

Genetic variants in the insulin-like growth factor-I (IGF-I)/insulin resistance axis may interact with lifestyle factors, influencing postmenopausal breast cancer risk, but these interrelated pathways are not fully understood. In this study, we examined 54 single-nucleotide polymorphisms (SNP) in genes related to IGF-I/insulin phenotypes and signaling pathways and lifestyle factors in relation to postmenopausal breast cancer, using data from 6,567 postmenopausal women in the Women's Health Initiative Harmonized and Imputed Genome-Wide Association Studies. We used a machine-learning method, two-stage random survival forest analysis. We identified three genetic variants (AKT1 rs2494740, AKT1 rs2494744, and AKT1 rs2498789) and two lifestyle factors [body mass index (BMI) and dietary alcohol intake] as the top five most influential predictors for breast cancer risk. The combination of the three SNPs, BMI, and alcohol consumption (≥1 g/day) significantly increased the risk of breast cancer in a gene and lifestyle dose-dependent manner. Our findings provide insight into gene-lifestyle interactions and will enable researchers to focus on individuals with risk genotypes to promote intervention strategies. These data also suggest potential genetic targets in future intervention/clinical trials for cancer prevention in order to reduce the risk for breast cancer in postmenopausal women. Cancer Prev Res; 11(1); 44-51. ©2017 AACR.

Genetic variants and traits related to insulin-like growth factor-I and insulin resistance and their interaction with lifestyles on postmenopausal colorectal cancer risk

Genetic variants and traits in metabolic signaling pathways may interact with lifestyle factors such as obesity, physical activity, and exogenous estrogen (E), influencing postmenopausal colorectal cancer (CRC) risk, but these interrelated pathways are not fully understood. In this case-cohort study, we examined 33 single-nucleotide polymorphisms (SNPs) in genes related to insulin-like growth factor-I (IGF-I)/ insulin resistance (IR) traits and signaling pathways, using data from 704 postmenopausal women in Women’s Health Initiative Observation ancillary studies. Stratifying by the lifestyle modifiers, we assessed the effects of IGF-I/IR traits (fasting total and free IGF-I, IGF binding protein-3, insulin, glucose, and homeostatic model assessment–insulin resistance) on CRC risk as a mediator or influencing factor. Six SNPs in the INS, IGF-I, and IGFBP3 genes were associated with CRC risk, and those associations differed between non-obese/active and obese/inactive women and between E nonusers and users. Roughly 30% of the cancer risk due to the SNP was mediated by IGF-I/IR traits. Likewise, carriers of 11 SNPs in the IRS1 and AKT1/2 genes (signaling pathway–related genetic variants) had different associations with CRC risk between strata, and the proportion of the SNP–cancer association explained by traits varied from 30% to 50%. Our findings suggest that IGF-I/IR genetic variants interact with obesity, physical activity, and exogenous E, altering postmenopausal CRC risk, through IGF-I/IR traits, but also through different pathways. Unraveling gene–phenotype–lifestyle interactions will provide data on potential genetic targets in clinical trials for cancer prevention and intervention strategies to reduce CRC risk.

Interaction of insulin-like growth factor-I and insulin resistance-related genetic variants with lifestyle factors on postmenopausal breast cancer risk

PURPOSE

Genetic variants and traits in metabolic signaling pathways may interact with obesity, physical activity, and exogenous estrogen (E), influencing postmenopausal breast cancer risk, but these inter-related pathways are incompletely understood.

METHODS

We used 75 single-nucleotide polymorphisms (SNPs) in genes related to insulin-like growth factor-I (IGF-I)/insulin resistance (IR) traits and signaling pathways, and data from 1003 postmenopausal women in Women's Health Initiative Observation ancillary studies. Stratifying via obesity and lifestyle modifiers, we assessed the role of IGF-I/IR traits (fasting IGF-I, IGF-binding protein 3, insulin, glucose, and homeostatic model assessment-insulin resistance) in breast cancer risk as a mediator or influencing factor.

RESULTS

Seven SNPs in IGF-I and INS genes were associated with breast cancer risk. These associations differed between non-obese/active and obese/inactive women and between exogenous E non-users and users. The mediation effects of IGF-I/IR traits on the relationship between these SNPs and cancer differed between strata, but only roughly 35% of the cancer risk due to the SNPs was mediated by traits. Similarly, carriers of 20 SNPs in PIK3R1, AKT1/2, and MAPK1 genes (signaling pathways-genetic variants) had different associations with breast cancer between strata, and the proportion of the SNP-cancer relationship explained by traits varied 45-50% between the strata.

CONCLUSIONS

Our findings suggest that IGF-I/IR genetic variants interact with obesity and lifestyle factors, altering cancer risk partially through pathways other than IGF-I/IR traits. Unraveling gene-phenotype-lifestyle interactions will provide data on potential genetic targets in clinical trials for cancer prevention and intervention strategies to reduce breast cancer risk.

Insulin-like growth factor (IGF) axis in cancerogenesis

Determination of the role of insulin-like growth factor (IGF) family components in carcinogenesis of several human tumors is based on numerous epidemiological and pre-clinical studies, experiments in vivo and in vitro and on attempts at application of drugs affecting the IGF axis. Investigative hypotheses in original studies were based on biological functions manifested by the entire family of IGF (ligands, receptors, linking proteins, adaptor molecules). In the context of carcinogenesis the most important functions of IGF family involve intensification of proliferation and inhibition of cell apoptosis and effect on cell transformation through synthesis of several regulatory proteins. IGF axis controls survival and influences on metastases of cells. Interactions of IGF axis components may be of a direct or indirect nature. The direct effects are linked to activation of PI3K/Akt signaling pathway, in which the initiating role is first of all played by IGF-1 and IGF-1R. Activity of this signaling pathway leads to an increased mitogenesis, cell cycle progression, and protection against different apoptotic stresses. Indirect effects of the axis depend on interactions between IGF and other molecules important for cancer etiology (e.g. sex hormones, products of suppressor genes, viruses, and other GFs) and the style of life (nutrition, physical activity). From the clinical point of view, components of IGF system are first of all considered as diagnostic serous and/or tissue biomarkers of a given cancer, prognostic factors and attractive target of modern anti-tumor therapies. Several mechanisms in which IGF system components act in the process of carcinogenesis need to be clarified, mainly due to multifactorial etiology of the neoplasms. Pin-pointing of the role played in carcinogenesis by any single signaling pathway remains particularly difficult. The aim of this review is to summarize the current data of several epidemiological studies, experiments in vitro and on animal models, to increase our understanding of the complex role of IGF family components in the most common human cancers.

Genetic Variants in the Insulin-like Growth Factor Pathway and Colorectal Cancer Risk in the Netherlands Cohort Study

Interrelationships between insulin-like growth factors (IGFs), hyperinsulinaemia, diabetes, and colorectal cancer (CRC) indicate involvement of IGFs in colorectal tumorigenesis. We investigated the CRC risk associated with 24 single nucleotide polymorphisms (SNPs) in 9 genes related to the IGF pathway and an IGF1 19-CA repeat polymorphism. Variants were selected from literature and genotyped in toenail DNA from 3,768 subcohort members and 2,580 CRC cases from the Netherlands Cohort Study, which has a case-cohort design (n = 120,852). We used the follow-up period 1986–2002. Eighteen SNPs were unequivocally associated with selected endpoints in the literature and unfavorable alleles were aggregated into a genetic sum score. Cox regression showed that a higher genetic sum score significantly increased CRC risk at all subsites, except the rectum, in men (highest vs. lowest tertile: HR for CRC = 1.36, 95% CI: 1.11, 1.65; P-trend = 0.002). Single SNPs (except the IGF1 SNP rs5742694) were not associated with risk. Models including the total number of IGF1 19-CA repeats showed CRC risk was halved at all subsites in women carrying <38 repeats but not >38 repeats (≤36 versus 38 repeats: HR for CRC = 0.44; 95% CI: 0.33, 0.58; P-trend < 0.001). These findings support a role for variants in IGF-related genes in colorectal tumorigenesis.

Impact of the IGFBP3 A-202C polymorphism on susceptibility and clinicopathologic features of breast cancer

BACKGROUND

Insulin-like growth factor binding protein 3 (IGFBP3) plays an important role in cellular proliferation, differentiation, apoptosis, and mammary carcinogenesis. Genetic variations in IGFBP3 have been identified to influence the circulating IGFBP3 level. The present study determined the impact of an important promoter polymorphism (A-202C, rs2854744) on susceptibility and progression of breast cancer in a Chinese population.

METHODS

We genotyped the IGFBP3 A-202C polymorphism in a case-control study involving 465 breast cancer patients and 799 age-matched, cancer-free controls using the TaqMan method. Logistic regression was used to assess the genetic association between the occurrence and progression of breast cancer.

RESULTS

Compared with the wild genotype (-202AA), we found a statistically significant increased risk of breast cancer associated with the variant genotypes (CC vs. AA: OR=2.00, 95% CI=1.25-3.21; AC+CC vs. AA: OR=1.34, 95% CI=1.06-1.70). In the stratified analysis, the increased risk was more apparent among the subgroups of older subjects (OR=1.70, 95% CI=1.20-2.42). Furthermore, we found that patients carrying variant genotypes (AC+CC) had a significantly greater prevalence of large tumor size (OR=1.72, 95% CI=1.13-2.64; P=0.021).

CONCLUSION

Our results suggest that the functional IGFBP3 A-202C polymorphism may influence the susceptibility and progression of breast cancer in the Chinese population.

Competing risks data analysis with high-dimensional covariates: an application in bladder cancer

Analysis of microarray data is associated with the methodological problems of high dimension and small sample size. Various methods have been used for variable selection in high-dimension and small sample size cases with a single survival endpoint. However, little effort has been directed toward addressing competing risks where there is more than one failure risks. This study compared three typical variable selection techniques including Lasso, elastic net, and likelihood-based boosting for high-dimensional time-to-event data with competing risks. The performance of these methods was evaluated via a simulation study by analyzing a real dataset related to bladder cancer patients using time-dependent receiver operator characteristic (ROC) curve and bootstrap .632+ prediction error curves. The elastic net penalization method was shown to outperform Lasso and boosting. Based on the elastic net, 33 genes out of 1381 genes related to bladder cancer were selected. By fitting to the Fine and Gray model, eight genes were highly significant (P<0.001). Among them, expression of RTN4, SON, IGF1R, SNRPE, PTGR1, PLEK, and ETFDH was associated with a decrease in survival time, whereas SMARCAD1 expression was associated with an increase in survival time. This study indicates that the elastic net has a higher capacity than the Lasso and boosting for the prediction of survival time in bladder cancer patients. Moreover, genes selected by all methods improved the predictive power of the model based on only clinical variables, indicating the value of information contained in the microarray features.

The role of the insulin-like growth factor-1 system in breast cancer

IGF-1 is a potent mitogen of major importance in the mammary gland. IGF-1 binding to the cognate receptor, IGF-1R, triggers a signaling cascade leading to proliferative and anti-apoptotic events. Although many of the relevant molecular pathways and intracellular cascades remain to be elucidated, a growing body of evidence points to the important role of the IGF-1 system in breast cancer development, progression and metastasis. IGF-1 is a point of convergence for major signaling pathways implicated in breast cancer growth. In this review, we provide an overview and concise update on the function and regulation of IGF-1 as well as the role it plays in breast malignancies.

Analysis of IGF(CA)19 and IGFBP3-202A/C gene polymorphisms in patients with acromegaly: association with clinical presentation and response to treatments

OBJECTIVE

IGF1 and IGFBP3 gene polymorphisms have been recently described. However, their potential role in the setting of acromegaly and its outcome is unknown. In this study, we analyze these polymorphisms in patients with acromegaly and investigate their association with clinical presentation and response to treatments.

DESIGN

A retrospective observational study was conducted in patients with acromegaly to analyze IGF1 and IGFBP3 gene polymorphisms.

METHODS

A total of 124 patients with acromegaly (57.3% women, mean age 44.9±13.1 years old) were followed up for a period of 11.4±8.0 years in eight tertiary referral hospitals in Spain. Clinical and analytical data were evaluated at baseline and after treatment. IGF1 and IGFBP3 gene polymorphisms were analyzed using PCR and specific primers.

RESULTS

Baseline laboratory test results were GH 19.3 (8.0-39.6) ng/ml, nadir GH 11.8 (4.1-21.5) ng/ml, and index IGF1 2.65±1.25 upper limit of normal. Regarding the IGF1 gene polymorphism, we did not find any association between the number of cyto-adenosine (CA) repeats and patients' baseline characteristics. Nevertheless, a trend for higher nadir GH values was observed in patients with <19 CA repeats. Regarding the IGFBP3 polymorphism, the absence of an A allele at the -202 position was associated with a higher baseline IGF1 and a higher prevalence of cancer and polyps. There were no differences in response to therapies according to the specific genotypes.

CONCLUSIONS

Polymorphisms in the IGF1 and IGFBP3 genes may not be invariably determinant of treatment outcome in acromegalic patients, but they may be associated with higher nadir GH levels or baseline IGF1, and determine a higher rate of colorectal polyps and cancer.

An exon variant in insulin receptor gene is associated with susceptibility to colorectal cancer in women

Given the role of insulin resistance in colorectal cancer (CRC), we explored whether genetic variants in insulin (INS), insulin receptor (INSR), insulin receptor substrate 1 (IRS1), insulin receptor substrate 2 (IRS2), insulin-like growth factor 1 (IGF1), and insulin-like growth factor binding protein 3 (IGFBP3) genes were associated with CRC risk. A total of 600 subjects, including 261 cases with CRC and 339 controls, were enrolled in this case-control study. Six polymorphisms in INS (rs689), INSR (rs1799817), IRS1 (rs1801278), IRS2 (rs1805097), IGF1 (rs5742612), and IGFBP3 (rs2854744) genes were genotyped using PCR-RFLP method. No significant difference was observed for INS, INSR, IRS1, IRS2, IGF1, and IGFBP3 genes between the cases and controls. However, the INSR rs1799817 "TT + CT" genotype and "CT" genotype compared with "CC" genotype occurred more frequently in the women with CRC than women controls (P = 0.007; OR = 1.93, 95 %CI = 1.20-3.11 and P = 0.002, OR = 2.15, 95 %CI = 1.31-3.53, respectively), and the difference remained significant after adjustment for confounding factors including age, BMI, smoking status, NSAID use, and family history of CRC (P = 0.018; OR = 1.86, 95 %CI = 1.11-3.10 and P = 0.004, OR = 2.18, 95 %CI = 1.28-3.71, respectively). In conclusion, to our knowledge, this study indicated for the first time that the INSR rs1799817 TT + CT genotype and CT genotype compared with the CC genotype had 1.86-fold and 2.18-fold increased risks for CRC among women, respectively. Furthermore, this finding is in line with previous studies which found significant associations between other variants of the INSR gene and CRC risk. Nevertheless, further studies are required to confirm our findings.