DataSheet_1_Monitoring of telomere dynamics in peripheral blood leukocytes in relation to colorectal cancer patients’ outcomes.docx

We investigated the possible associations between leukocyte telomere length, therapy outcomes, and clinicopathological features in patients with colorectal cancer. Additionally, telomerase reverse transcriptase (TERT) expression was evaluated. Telomere length was measured using singleplex qPCR in 478 consecutive leukocyte DNA samples from 198 patients. Blood was drawn at diagnosis prior to any therapy and then at 6-month intervals for 18 months. Following diagnosis, the telomeres gradually shortened during the course of the treatment regardless of the patient’s age. The most pronounced decrease was observed 12 months after the diagnosis (p < 0.0001). Based on tumor localization, the decrease in telomere length one year after the diagnosis followed different trajectories (p = 0.03). In patients treated with adjuvant therapy, telomere length correlated with the time elapsed after completion of therapy (p = 0.03). TERT expression did not correlate with the telomere length; however, it was higher in women than men (1.35-fold, 95% CI 1.11–1.65, p = 0.003) and in smokers than non-smokers (1.27-fold, 95% CI 1.01–1.61, p = 0.04). Leukocyte telomere length declines naturally during aging, but the accelerated shortening observed in our patients was age-independent. Telomere length manifestly reflected chemotherapy impact and could be linked to therapy toxicity.</p

Table_1_Monitoring of telomere dynamics in peripheral blood leukocytes in relation to colorectal cancer patients’ outcomes.pdf

We investigated the possible associations between leukocyte telomere length, therapy outcomes, and clinicopathological features in patients with colorectal cancer. Additionally, telomerase reverse transcriptase (TERT) expression was evaluated. Telomere length was measured using singleplex qPCR in 478 consecutive leukocyte DNA samples from 198 patients. Blood was drawn at diagnosis prior to any therapy and then at 6-month intervals for 18 months. Following diagnosis, the telomeres gradually shortened during the course of the treatment regardless of the patient’s age. The most pronounced decrease was observed 12 months after the diagnosis (p < 0.0001). Based on tumor localization, the decrease in telomere length one year after the diagnosis followed different trajectories (p = 0.03). In patients treated with adjuvant therapy, telomere length correlated with the time elapsed after completion of therapy (p = 0.03). TERT expression did not correlate with the telomere length; however, it was higher in women than men (1.35-fold, 95% CI 1.11–1.65, p = 0.003) and in smokers than non-smokers (1.27-fold, 95% CI 1.01–1.61, p = 0.04). Leukocyte telomere length declines naturally during aging, but the accelerated shortening observed in our patients was age-independent. Telomere length manifestly reflected chemotherapy impact and could be linked to therapy toxicity.</p

Table_2_Monitoring of telomere dynamics in peripheral blood leukocytes in relation to colorectal cancer patients’ outcomes.pdf

We investigated the possible associations between leukocyte telomere length, therapy outcomes, and clinicopathological features in patients with colorectal cancer. Additionally, telomerase reverse transcriptase (TERT) expression was evaluated. Telomere length was measured using singleplex qPCR in 478 consecutive leukocyte DNA samples from 198 patients. Blood was drawn at diagnosis prior to any therapy and then at 6-month intervals for 18 months. Following diagnosis, the telomeres gradually shortened during the course of the treatment regardless of the patient’s age. The most pronounced decrease was observed 12 months after the diagnosis (p < 0.0001). Based on tumor localization, the decrease in telomere length one year after the diagnosis followed different trajectories (p = 0.03). In patients treated with adjuvant therapy, telomere length correlated with the time elapsed after completion of therapy (p = 0.03). TERT expression did not correlate with the telomere length; however, it was higher in women than men (1.35-fold, 95% CI 1.11–1.65, p = 0.003) and in smokers than non-smokers (1.27-fold, 95% CI 1.01–1.61, p = 0.04). Leukocyte telomere length declines naturally during aging, but the accelerated shortening observed in our patients was age-independent. Telomere length manifestly reflected chemotherapy impact and could be linked to therapy toxicity.</p

Investigation of single and synergic effects of <i>NLRC5</i> and <i>PD-L1</i> variants on the risk of colorectal cancer

<div><p>Constitutive activation of interferon signaling pathways has been reported in colorectal cancer (CRC), leading to a strong CD8⁺ T cell response through stimulation of <i>NLRC5</i> expression. Primed CD8⁺ T cell expansion, however, may be negatively regulated by <i>PD-L1</i> expression. Additionally, aberrant <i>PD-L1</i> expression enables cancer cells to escape the immune attack. Our study aimed to select potential regulatory variants in the <i>NLRC5</i> and <i>PD-L1</i> genes by using several online <i>in silico</i> tools, such as UCSC browser, HaploReg, Regulome DB, Gtex Portal, microRNA and transcription factor binding site prediction tools and to investigate their influence on CRC risk in a Czech cohort of 1424 CRC patients and 1114 healthy controls. Logistic regression analysis adjusted for age and gender reported a moderate association between rectal cancer risk and two <i>NLRC5</i> SNPs, rs1684575 T>G (OR: 1.60, 95% CI: 1.13–2.27, recessive model) and rs3751710 (OR: 0.70, 95% CI: 0.51–0.96, dominant model). Given that a combination of genetic variants, rather than a single polymorphism, may explain better the genetic etiology of CRC, we studied the interplay between the variants within <i>NLRC5</i>, <i>PD-L1</i> and the previously genotyped <i>IFNGR1</i> and <i>IFNGR2</i> variants, to evaluate their involvement in the risk of CRC development. Overall we obtained 18 pair-wise interactions within and between the <i>NLRC5</i> ad <i>PD-L1</i> genes and 6 more when <i>IFNGR</i> variants were added. Thirteen out of the 24 interactions were below the threshold for the FDR calculated and controlled at an arbitrary level q*<0.10. Furthermore, the interaction <i>IFNGR2</i> rs1059293 C>T—<i>NLRC5</i> rs289747 G>A (P<0.0001) remained statistically significant even after Bonferroni correction. Our data suggest that not only a single genetic variant but also an interaction between two or more variants within genes involved in immune regulation may play important roles in the onset of CRC, providing therefore novel biological information, which could eventually improve CRC risk management but also PD-1-based immunotherapy in CRC.</p></div

Characteristics of the colorectal cancer patients.

<p>Characteristics of the colorectal cancer patients.</p

<i>NLRC5-PD-L1</i> pair-wise interactions with cases and controls.

<p>Only the best genetic model of each SNP pair is shown.</p

<i>NLRC5-PD-L1-IFNGR1/2</i> pair-wise interactions.

<p> The color indicates the SNPs’ location displayed by UCSC Genome Browser on lymphoblastoid cell lines (GM12878).</p