CASR rs1801725 polymorphism is associated with the risk and prognosis of colorectal cancer: A case-control study

Calcium intake and genetic variants in the calcium sensing receptor in relation to colorectal cancer mortality: an international consortium study of 18,952 patients

Background

Research on calcium intake as well as variants in the calcium sensor receptor (CaSR) gene and their interaction in relation to CRC survival is still limited.

Methods

Data from 18,952 CRC patients, were included. Associations between primarily pre-diagnostic dietary (n = 13.085), supplemental (n = 11,837), total calcium intake (n = 5970) as well as 325 single nucleotide polymorphisms (SNPs) of the CaSR gene (n = 15,734) in relation to CRC-specific and all-cause mortality were assessed using Cox proportional hazard models. Also interactions between calcium intake and variants in the CaSR gene were assessed.

Results

During a median follow-up of 4.8 years (IQR 2.4-8.4), 6801 deaths occurred, of which 4194 related to CRC. For all-cause mortality, no associations were observed for the highest compared to the lowest sex- and study-specific quartile of dietary (HR 1.00, 95%CI 0.92-1.09), supplemental (HR 0.97, 95%CI 0.89-1.06) and total calcium intake (HR 0.99, 95%CI 0.88-1.11). No associations with CRC-specific mortality were observed either. Interactions were observed between supplemental calcium intake and several SNPs of the CaSR gene.

Conclusion

Calcium intake was not associated with all-cause or CRC-specific mortality in CRC patients. The association between supplemental calcium intake and all-cause and CRC-specific mortality may be modified by genetic variants in the CaSR gene.

Targeting beta-catenin signaling for prevention of colorectal cancer - Nutraceutical, drug, and dietary options

Progressive up-regulation of β-catenin signaling is very common in the transformation of colorectal epithelium to colorectal cancer (CRC). Practical measures for opposing such signaling hence have potential for preventing or slowing such transformation. cAMP/PKA activity in colon epithelium, as stimulated by COX-2-generated prostaglandins and β2-adrenergic signaling, boosts β-catenin activity, whereas cGMP/PKG signaling has the opposite effect. Bacterial generation of short-chain fatty acids (as supported by unrefined high-carbohydrate diets, berberine, and probiotics), dietary calcium, daily aspirin, antioxidants opposing cox-2 induction, and nicotine avoidance, can suppress cAMP production in colonic epithelium, whereas cGMP can be boosted via linaclotides, PDE5 inhibitors such as sildenafil or icariin, and likely high-dose biotin. Selective activation of estrogen receptor-β by soy isoflavones, support of adequate vitamin D receptor activity with UV exposure or supplemental vitamin D, and inhibition of CK2 activity with flavanols such as quercetin, can also oppose β-catenin signaling in colorectal epithelium. Secondary bile acids, the colonic production of which can be diminished by low-fat diets and berberine, can up-regulate β-catenin activity by down-regulating farnesoid X receptor expression. Stimulation of PI3K/Akt via insulin, IGF-I, TLR4, and EGFR receptors boosts β-catenin levels via inhibition of glycogen synthase-3β; plant-based diets can down-regulate insulin and IGF-I levels, exercise training and leanness can keep insulin low, anthocyanins and their key metabolite ferulic acid have potential for opposing TLR4 signaling, and silibinin is a direct antagonist for EGFR. Partially hydrolyzed phytate can oppose growth factor-mediated down-regulation of β-catenin by inhibiting Akt activation. Multifactorial strategies for safely opposing β-catenin signaling can be complemented with measures that diminish colonic mutagenesis and DNA hypomethylation - such as avoidance of heme-rich meat and charred or processed meats, consumption of phase II-inductive foods and nutraceuticals (e.g., Crucifera), and assurance of adequate folate status.

Haplotype of CaSR gene is associated with risk of renal stone disease in West Indian population

Calcium is the most abundant metabolite involved in the stone matrix. The CaSR gene controls calcium homeostasis, and genetic variation in the CaSR gene could lead to the development of renal stone disease. Therefore, the current study has been designed to assess the association of genetic variants of CaSR gene polymorphisms with renal stone disease. A single-centric prospective study has been carried out on a total of 300 participants (150 cases and 150 controls). Serum levels of calcium, creatinine, parathyroid hormone, and 24 h urine metabolites were measured. Two polymorphisms, rs1801725 and rs1042636, of the CaSR gene, have been genotyped for each participant. T test, binary logistic regression, and Chi-square analysis were used for statistical analysis. Renal stone patients had significantly higher levels of serum parathyroid hormone, creatinine, and 24-h urine metabolites in comparison to the controls. CaSR gene variants, rs1801725 (GG) and rs1042636 (AA), both have shown significant association with renal stone disease. In addition, individuals having specific genotypes along with metabolic abnormalities such as hypercalcemia and hyperparathyroidism are found to be at a higher significant risk of developing the renal stone disease. In the present study, the haplotype of the CaSR gene has shown an association with renal stone disease. Individuals with hyperparathyroidism and hypercalcemia and risk genotype have a higher susceptibility to developing renal stone disease.

CpG Site-Based Signature Predicts Survival of Colorectal Cancer

BACKGROUND

A critical unmet medical need in clinical management of colorectal cancer (CRC) pivots around lack of noninvasive and or minimally invasive techniques for early diagnosis and prognostic prediction of clinical outcomes. Because DNA methylation can capture the regulatory landscape of tumors and can be measured in body fluids, it provides unparalleled opportunities for the discovery of early diagnostic and prognostics markers predictive of clinical outcomes. Here we investigated use of DNA methylation for the discovery of potential clinically actionable diagnostic and prognostic markers for predicting survival in CRC.

METHODS

We analyzed DNA methylation patterns between tumor and control samples to discover signatures of CpG sites and genes associated with CRC and predictive of survival. We conducted functional analysis to identify molecular networks and signaling pathways driving clinical outcomes.

RESULTS

We discovered a signature of aberrantly methylated genes associated with CRC and a signature of thirteen (13) CpG sites predictive of survival. We discovered molecular networks and signaling pathways enriched for CpG sites likely to drive clinical outcomes.

CONCLUSIONS

The investigation revealed that CpG sites can predict survival in CRC and that DNA methylation can capture the regulatory state of tumors through aberrantly methylated molecular networks and signaling pathways.

CASR rs1801725 polymorphism is associated with the risk and prognosis of colorectal cancer: A case-control study

BACKGROUND

The extracellular calcium-sensing receptor (CASR) controls body calcium homeostasis. Increased levels of calcium are associated with protecting against colorectal cancer (CRC). This study aimed to determine the relationship between CASR gene rs1801725 polymorphism and CRC risk and prognosis.

METHODS

We conducted a hospital-based case-control study and a meta-analysis to evaluate the association of CASR gene rs1801725 polymorphism with CRC susceptibility.

RESULTS

This study proved that CASR rs1801725 polymorphism was associated with a higher risk to develop CRC (TT vs GG: OR 1.92, 95% CI [1.03-3.59], P = .042; T vs G: OR 1.30, 95% CI [1.03-1.64], P = .030). Subgroup analysis showed that this polymorphism increased the risk of CRC among smokers, and those aged ≥60 years (TT vs GG: OR 3.37, 95% CI [1.12-10.14], P = .034). We also found that this polymorphism was associated with the tumor size, TNM stage, and lymph node metastasis of CRC (GT vs GG: OR 2.03, 95% CI [1.32-3.10], P = .001). In addition, CASR gene rs1801725 polymorphism correlated with the survival of CRC patients. Further meta-analysis also obtained a significant association between this SNP and CRC risk (TT + GT vs GG: OR 1.28, 95% CI [1.01, 1.63], P = .041). Subgroup analyses by ethnicity observed a link between rs1801725 polymorphism and CRC risk in Asians, but not in Caucasians and mixed populations.

CONCLUSION

In conclusion, this case-control study and meta-analysis showed that CASR rs1801725 polymorphism increased the risk of CRC. Further studies from other races are urgently needed.