Parathormone and 1,25(OH)2D3 but not 25(OH)D3 serum levels, in an inverse correlation, reveal an association with advanced stages of colorectal cancer

Potential Use of 1-25-dihydroxyvitamin D in the Diagnosis and Treatment of Papillary Thyroid Cancer

BACKGROUND Low levels of 1-25-dihydroxyvitamin D3 [1,25(OH)2D3] in serum may be a risk factor for several tumor types. Also, high cathelicidin antimicrobial peptide (CAMP) expression is regarded to be important against tumor progression. We evaluated the potential importance of 1,25(OH)2D3 in the diagnosis and treatment of papillary thyroid cancer (PTC). MATERIAL AND METHODS The preoperative serum level of 1,25(OH)2D3 was measured using a double-antibody sandwich enzyme-linked immunosorbent assay. Vitamin D3 receptor (VDR) expression was detected by streptavidin-peroxidase immunohistochemical staining in PTC specimens. Receiver operating characteristic (ROC) curves were created to assess the diagnostic value of 1,25(OH)2D3. The effect of 1,25(OH)2D3 on the proliferation and apoptosis of PTC cell lines were studied by Cell Counting Kit (CCK)-8 assay and Annexin V/propidium iodide staining, respectively. CAMP expression was measured by qRT-PCR and western blotting. Short interfering RNAs were used to reduce CAMP expression in PTC cell lines. RESULTS The preoperative serum level of 1,25(OH)2D3 in PTC was obviously lower than that in nodular goiter (NG) (P<0.05). The ROC curve suggested that 1,25(OH)2D3 might serve as a potential diagnostic value at a cutoff of 20.13 pg/mL, The VDR showed higher expression in PTC than in paired adjacent non-cancerous tissue. 1,25(OH)2D3 inhibited the proliferation and induced the apoptosis of PTC cells, and increased CAMP expression significantly, whereas CAMP knockdown demonstrated opposite effects. CONCLUSIONS 1,25(OH)2D3 may be a new, potential biomarker for the identification of PTC and NG. It may also become 1,25(OH)2D3 may a potential target for drug action to treat PTC through CAMP.

Parathyroid hormone gene rs6256 and calcium sensing receptor gene rs1801725 variants are not associated with susceptibility to colorectal cancer in Iran

BACKGROUND

Substantial evidence from epidemiological studies has suggested that increased levels of calcium may play a protective role against colorectal cancer (CRC). Given the vital role of calcium sensing receptor (CaSR) and parathyroid hormone (PTH) in the maintenance of calcium homeostasis, we explored whether the rs1801725 (A986S) variant located in exon 7 of the CaSR gene and the rs6256 variant located in exon 3 of PTH gene might be associated with CRC risk.

MATERIALS AND METHODS

In this study 860 subjects including 350 cases with CRC and 510 controls were enrolled and genotyped using PCR-RFLP methods.

RESULTS

We observed no significant difference in genotype or allele frequencies between the cases with CRC and controls for both CaSR and PTH genes either before or after adjustment for confounding factors including age, BMI, sex, smoking status, and family history of CRC. Furthermore, no evidence for effect modification of any association of rs1801725 and rs6256 variants and CRC by BMI, sex, or tumor site was observed. In addition, there was no significant difference in genotype and allele frequencies between the normal weight (BMI<25 kg/m2) cases and overweight/ obese (BMI≥25 kg/m2) cases for the two SNPs.

CONCLUSIONS

These data indicated that the CaSR gene A986S variant is not a genetic contributor to CRC risk in the Iranian population. Furthermore, our results suggest for the first time that PTH gene variant does not affect CRC risk. Nonetheless, further studies with larger sample size are needed to validate these findings.

Decreased preoperative serum 25-Hydroxyvitamin D levels in colorectal cancer are associated with systemic inflammation and serrated morphology

Deficiency of vitamin D is associated with increased risk of several types of cancer including colorectal cancer (CRC). However, factors contributing to low levels of 25-hydroxyvitamin D [25(OH)D] in CRC are not clear. Therefore, in this study serum 25(OH)D levels in 117 CRC patients and 86 controls were analyzed and correlated with the clinicopathological data including morphological subtype (serrated or conventional), quantity of tumor infiltrating immune cells, levels of systemic inflammatory markers, and disease outcome. We found that the patients had lower serum 25(OH)D levels compared to the controls. Interestingly, among the patients mismatch repair deficiency, serrated morphology, and high body mass index associated with lowest serum 25(OH)D levels. In addition, patients operated in summer or autumn had higher serum 25(OH)D levels. Furthermore, serum 25(OH)D levels inversely correlated with several systemic inflammatory markers, e.g. serum C reactive protein, but did not associate with prognosis. Mechanism leading to vitamin D deficiency in these patients are not clear but could be related to the effects of systemic inflammation. Longitudinal studies are warranted to assess vitamin D deficiency as a potential risk factor for serrated colorectal polyps and adenocarcinoma.

Prevalence of serum vitamin D deficiency and insufficiency in cancer: Review of the epidemiological literature

Vitamin D deficiency has been found to be associated with a variety of cancers, including prostate, multiple myeloma, colorectal and breast cancer. Several studies have shown vitamin D levels to have an inverse relation with cancer mortality, while others have considered it a potential risk factor. Vitamin D is believed to influence cancer prevalence, risk and survival; hence the need to assess vitamin D levels in cancer. Although numerous studies have been conducted to demonstrate vitamin D deficiency as a risk factor for cancer, relatively few have studied its prevalence. Moreover, studies estimating prevalence differ from each other, with respect to study population, sample size, study design, definition of vitamin D deficiency used and method of vitamin D assessment (with most studies limited to one particular type of cancer with relatively small sample sizes). Therefore, we qualitatively reviewed the epidemiological evidence in the oncology literature on the prevalence of vitamin D deficiency and insufficiency as measured by serum vitamin D concentrations.