Distribution bias analysis of germline and somatic single-nucleotide variations that impact protein functional site and neighboring amino acids

Exploring the Role of the TAS2R16 Protein and Its Single Nucleotide Variants in Pituitary Adenoma Development

BACKGROUND

Pituitary adenoma (PA) is a common benign tumor that develops in the pituitary gland, causing hormonal imbalances and potential health issues. The TAS2R16 gene codes for a taste receptor and is involved in bitter taste perception, but there is currently no known direct link between this gene and pituitary adenoma.

METHODS

This study included 221 healthy controls and 131 patients with pituitary adenoma (PA) from the Lithuanian population. DNA was isolated from peripheral venous blood using the salt precipitation method. Genotyping was performed via RT-PCR. Statistical analysis was conducted with IBM SPSS Statistics 29.0 software, incorporating the Bonferroni correction for multiple comparisons.

RESULTS

This study found that the TAS2R16 rs978739 C allele is less common in the non-invasive PA group compared to the control group (p = 0.045). The TAS2R16 rs860170 CT genotype reduces the likelihood of developing non-invasive PA by 1.9-fold under the codominant (p = 0.024) and overdominant (p = 0.030) models. The odds of developing non-invasive PA are reduced by 2-fold under the dominant (p = 0.021) model for TAS2R16 rs860170 CT + CC genotypes and by 2-fold under the additive (p = 0.018) model for each TAS2R16 rs860170 C allele. The PA group had higher serum levels of TAS2R16 than the control group (p < 0.001). The present study found that patients with the TAS2R16 rs978739 TT or CT genotype had higher serum TAS2R16 levels and protein concentrations than healthy individuals (p = 0.025 and p = 0.019, respectively), and those with the AA or AG genotype of TAS2R16 rs1357949 had higher protein concentrations (p = 0.005 and p = 0.007, respectively).

CONCLUSIONS

The TAS2R16 rs978739 C allele was less common in the non-invasive PA group compared to the control group, while the TAS2R16 rs860170 CT genotype was linked to a reduced likelihood of developing non-invasive PA. Additionally, the PA group showed higher serum levels of TAS2R16, and increased serum protein concentrations were observed in PA patients with specific TAS2R16 variants.

Scanning window analysis of non-coding regions within normal-tumor whole-genome sequence samples

Genomics has benefited from an explosion in affordable high-throughput technology for whole-genome sequencing. The regulatory and functional aspects in non-coding regions may be an important contributor to oncogenesis. Whole-genome tumor-normal paired alignments were used to examine the non-coding regions in five cancer types and two races. Both a sliding window and a binning strategy were introduced to uncover areas of higher than expected variation for additional study. We show that the majority of cancer associated mutations in 154 whole-genome sequences covering breast invasive carcinoma, colon adenocarcinoma, kidney renal papillary cell carcinoma, lung adenocarcinoma and uterine corpus endometrial carcinoma cancers and two races are found outside of the coding region (4 432 885 in non-gene regions versus 1 412 731 in gene regions). A pan-cancer analysis found significantly mutated windows (292 to 3881 in count) demonstrating that there are significant numbers of large mutated regions in the non-coding genome. The 59 significantly mutated windows were found in all studied races and cancers. These offer 16 regions ripe for additional study within 12 different chromosomes-2, 4, 5, 7, 10, 11, 16, 18, 20, 21 and X. Many of these regions were found in centromeric locations. The X chromosome had the largest set of universal windows that cluster almost exclusively in Xq11.1-an area linked to chromosomal instability and oncogenesis. Large consecutive clusters (super windows) were found (19 to 114 in count) providing further evidence that large mutated regions in the genome are influencing cancer development. We show remarkable similarity in highly mutated non-coding regions across both cancer and race.