| 1. |
- Brandão, Andreia, et al.
(författare)
-
The CHEK2 Variant C.349A>G Is Associated with Prostate Cancer Risk and Carriers Share a Common Ancestor
- 2020
-
Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 12:11
-
Tidskriftsartikel (refereegranskat)abstract
- The identification of recurrent founder variants in cancer predisposing genes may have important implications for implementing cost-effective targeted genetic screening strategies. In this study, we evaluated the prevalence and relative risk of the CHEK2 recurrent variant c.349A>G in a series of 462 Portuguese patients with early-onset and/or familial/hereditary prostate cancer (PrCa), as well as in the large multicentre PRACTICAL case-control study comprising 55,162 prostate cancer cases and 36,147 controls. Additionally, we investigated the potential shared ancestry of the carriers by performing identity-by-descent, haplotype and age estimation analyses using high-density SNP data from 70 variant carriers belonging to 11 different populations included in the PRACTICAL consortium. The CHEK2 missense variant c.349A>G was found significantly associated with an increased risk for PrCa (OR 1.9; 95% CI: 1.1-3.2). A shared haplotype flanking the variant in all carriers was identified, strongly suggesting a common founder of European origin. Additionally, using two independent statistical algorithms, implemented by DMLE+2.3 and ESTIAGE, we were able to estimate the age of the variant between 2300 and 3125 years. By extending the haplotype analysis to 14 additional carrier families, a shared core haplotype was revealed among all carriers matching the conserved region previously identified in the high-density SNP analysis. These findings are consistent with CHEK2 c.349A>G being a founder variant associated with increased PrCa risk, suggesting its potential usefulness for cost-effective targeted genetic screening in PrCa families.
|
|
| 2. |
- Conti, David, V, et al.
(författare)
-
Trans-ancestry genome-wide association meta-analysis of prostate cancer identifies new susceptibility loci and informs genetic risk prediction
- 2021
-
Ingår i: Nature Genetics. - : Springer Nature. - 1061-4036 .- 1546-1718. ; 53:1, s. 65-75
-
Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer is a highly heritable disease with large disparities in incidence rates across ancestry populations. We conducted a multiancestry meta-analysis of prostate cancer genome-wide association studies (107,247 cases and 127,006 controls) and identified 86 new genetic risk variants independently associated with prostate cancer risk, bringing the total to 269 known risk variants. The top genetic risk score (GRS) decile was associated with odds ratios that ranged from 5.06 (95% confidence interval (CI), 4.84-5.29) for men of European ancestry to 3.74 (95% CI, 3.36-4.17) for men of African ancestry. Men of African ancestry were estimated to have a mean GRS that was 2.18-times higher (95% CI, 2.14-2.22), and men of East Asian ancestry 0.73-times lower (95% CI, 0.71-0.76), than men of European ancestry. These findings support the role of germline variation contributing to population differences in prostate cancer risk, with the GRS offering an approach for personalized risk prediction. A meta-analysis of genome-wide association studies across different populations highlights new risk loci and provides a genetic risk score that can stratify prostate cancer risk across ancestries.
|
|
| 3. |
- Fessé, Per, 1973-
(författare)
-
Epidermal Melanocyte Response to Radiotherapy
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cutaneous interfollicular melanocytes protect the skin from UV-radiation (UVR), and their response to UVR is well established. To date, the response activated in melanocytes by repeated genotoxic insults from radiotherapy (RT) has not been explored. Assuming that the molecular pathways involved in the melanocyte response to UVR are similar upon ionizing radiation, the aim of this work was to examine the effects of RT concerning UVR-response proteins and resistance to DNA damage to reveal mechanisms behind hyperpigmentation and depigmentation caused by RT. The results are based on immunostained tissue sections of 530 not sun-exposed skin punch biopsies. These are collected before, during, and after the end of adjuvant RT from the thoracic wall of breast cancer patients and the hip region of prostate cancer patients receiving curative RT. Fractionated RT with daily doses between 0.05 and 2.0 Gy, as well as hypofractionation and accelerated fractionation were investigated. Based on this clinical assay sterilizing the hair follicles, excluding migration of immature melanocytes from the bulge, it was ensured that interfollicular melanocytes are an autonomous self-renewing cell population with cells presenting different degrees of differentiation of which one fourth is immature; the melanocytes divide rarely and are absolute radioresistant to any dose schedule of RT applied, keeping the number of melanocytes intact. Hyperradiosensitivity to dose fractions of 0.05 to 0.3 Gy is observed for DNA double strand breaks (DSBs), differentiation and anti-apoptotic signaling. Proliferation is not stimulated and apoptosis is negligible upon exposure to RT, and also post-treatment. Melanocyte differentiation is maintained during RT, but dedifferentiation occurs after RT ends. The expected activation of the p53/p21 signaling upon RT appears in keratinocytes but is attenuated in melanocytes. A new observation is that melanocytes constitutively express BMI1, further upregulated upon irradiation, indicating that melanocytes have stem cell properties, which suggest that BMI1 prevents apoptosis, terminal differentiation and premature senescence and likely allows dedifferentiation by suppressing the p53/p21-mediated response to genotoxic damage, in addition to the repression of p16 and ARF. Melanocytes exhibit and accumulate a higher amount of DSBs during the RT period compared to keratinocytes, indicating reduced repair capacity of DSBs in melanocytes. Thus, only efficient pro-survival mechanisms can explain the melanocyte radioresistance regarding cell death. The findings in this thesis suggest that melanocytes are protected by activation of the BMI1-NF-kappa/β-CXCL8/CXCR2 pathway, in addition to upregulation of Bcl-2 by melanocyte-specific MITF (microphthalmia-associated transcription factor).
|
|
