| 1. |
|
|
| 2. |
- Campbell, PJ, et al.
(författare)
-
Pan-cancer analysis of whole genomes
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
-
Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
|
|
| 3. |
- Sampson, Joshua N., et al.
(författare)
-
Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
-
Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
|
|
| 4. |
- Wang, Mo-Jin, et al.
(författare)
-
Downregulation of microRNA-124 is an independent prognostic factor in patients with colorectal cancer
- 2013
-
Ingår i: International Journal of Colorectal Disease. - : Springer Verlag (Germany). - 0179-1958 .- 1432-1262. ; 28:2, s. 183-189
-
Tidskriftsartikel (refereegranskat)abstract
- PurposeRecently, microRNA-124 (miR-124) has been demonstrated as a potential tumor suppressor in several types of cancers. However, the role of miR-124 in colorectal cancer remains unclear. This study was aimed at investigating the clinicopathological significance of miR-124 expression in colorectal cancer.MethodsQuantitative real-time PCR was used to analyze miR-124 expression in 96 colorectal cancers and individual-matched normal mucosa samples. The expression of miR-124 was assessed for associations with clinicopathological characteristics using chi-square test. The survival curves were calculated by the Kaplan–Meier method. The influence of each variable on survival was examined by the Cox multivariate regression analysis.ResultsThe miR-124 expression was significantly downregulated in colorectal cancer compared to normal mucosa (P = 0.001). In colorectal cancer, miR-124 decreased expression correlated significantly with the grade of differentiation (P = 0.021). Univariate survival analysis showed that the downregulated miR-124 was significantly correlated with worse prognosis, both in terms of overall survival (P = 0.017) and disease-free survival (DFS) (P = 0.014). Further, the downregulated miR-124 was demonstrated as a prognostic factor for overall survival (hazard ratio, HR = 4.634; 95 % confidence interval, CI, 1.731–12.404; P = 0.002) and DFS (HR = 4.533, 95 % CI 1.733–11.856, P = 0.002), independently of gender, age, location, maximum tumor size, depth of invasion, differentiation, and TNM stage.ConclusionsMiR-124 may play a certain role in the development of colorectal cancer. The downregulation expression of miR-124 is an independent prognostic factor in patients with colorectal cancer.
|
|
| 5. |
- Fan, Chuanwen, et al.
(författare)
-
Mismatch repair protein deficiency and its implications on distant metastasis in colorectal cancer : A comprehensive analysis
- 2024
-
Ingår i: Cancer Medicine. - : John Wiley & Sons. - 2045-7634. ; 13:7
-
Tidskriftsartikel (refereegranskat)abstract
- Background: While previous studies have indicated variability in distant metastatic potential among different mismatch repair (MMR) states in colorectal cancer (CRC), their findings remain inconclusive, especially considering potential differences across various ethnic backgrounds. Furthermore, the gene regulatory networks and the underlying mechanisms responsible for these variances in metastatic potential across MMR states have yet to be elucidated.Methods: We collected 2058 consecutive primary CRC samples from the South West of China and assessed the expression of MMR proteins (MLH1, MSH2, MSH6, and PMS2) using immunohistochemistry. To explore the inconsistencies between different MMR statuses and recurrence, we performed a meta-analysis. To delve deeper, we employed Weighted Gene Co-expression Network Analysis (WGCNA), ClueGo, and iRegulon, pinpointing gene expression networks and key regulatory molecules linked to metastasis and recurrence in CRC. Lastly, both univariate and multivariate Cox regression analyses were applied to determine the impact of core regulatory molecules on metastasis.Results: Of the samples, 8.2% displayed deficient MMR (dMMR), with losses of MLH1 and PSM2 observed in 40.8% and 63.9%, respectively. A unique 24.3% isolated loss of PMS2 without concurrent metastasis was identified, a result that diverges from established literature. Additionally, our meta-analysis further solidifies the reduced recurrence likelihood in dMMR CRC samples compared to proficient MMR (pMMR). Two gene expression networks tied to distant metastasis and recurrence were identified, with a majority of metastasis-related genes located on chromosomes 8 and 18. An IRF1 positive feedback loop was discerned in the metastasis-related network, and IRF1 was identified as a predictive marker for both recurrence-free and distant metastasis-free survival across multiple datasets.Conclusion: Geographical and ethnic factors might influence peculiarities in MMR protein loss. Our findings also highlight new gene expression networks and crucial regulatory molecules in CRC metastasis, enhancing our comprehension of the mechanisms driving distant metastasis.
|
|
| 6. |
- Machiela, Mitchell J., et al.
(författare)
-
Characterization of Large Structural Genetic Mosaicism in Human Autosomes
- 2015
-
Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 96:3, s. 487-497
-
Tidskriftsartikel (refereegranskat)abstract
- Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 x 3 10(-31)) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population.
|
|
| 7. |
- Machiela, Mitchell J, et al.
(författare)
-
Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome
- 2016
-
Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.
|
|
| 8. |
- Wang, Mo-Jin, et al.
(författare)
-
The prognostic factors and multiple biomarkers in young patients with colorectal cancer
- 2015
-
Ingår i: Scientific Reports. - : Nature Publishing Group: Open Access Journals - Option C / Nature Publishing Group. - 2045-2322. ; 5:10645
-
Tidskriftsartikel (refereegranskat)abstract
- The incidence of colorectal cancer (CRC) in young patients (less than= 50 years of age) appears to be increasing. However, their clinicopathological characteristics and survival are controversial. Likewise, the biomarkers are unclear. We used the West China (2008-2013, China), Surveillance, Epidemiology, and End Results program (1973-2011, United States) and Linkoping Cancer (1972-2009, Sweden) databases to analyse clinicopathological characteristics, survival and multiple biomarkers of young CRC patients. A total of 509,934 CRC patients were included from the three databases. The young CRC patients tended to have more distal location tumours, fewer tumour numbers, later stage, more mucinous carcinoma and poorer differentiation. The cancer-specific survival (CSS) of young patients was significantly better. The PRL (HR = 12.341, 95% CI = 1.615-94.276, P = 0.010), RBM3 (HR = 0.093, 95% CI = 0.012-0.712, P = 0.018), Wrap53 (HR = 1.952, 95% CI = 0.452-6.342, P = 0.031), p53 (HR = 5.549, 95% CI = 1.176-26.178, P = 0.045) and DNA status (HR = 17.602, 95% CI = 2.551-121.448, P = 0.001) were associated with CSS of the young patients. In conclusion, this study suggests that young CRC patients present advanced tumours and more malignant pathological features, while they have a better prognosis. The PRL, RBM3, Wrap53, p53 and DNA status are potential prognostic biomarkers for the young CRC patients.
|
|
| 9. |
- Zhang, Dan, et al.
(författare)
-
Polymorphisms of Glucose-Regulated Protein 78 and Risk of Colorectal Cancer : A Case-Control Study in Southwest China
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:6
-
Tidskriftsartikel (refereegranskat)abstract
- Glucose-regulated protein 78 (GRP78), an endoplasmic reticulum chaperone, up-regulation serves as an efficient mechanism to promote malignant transformation of colorectal cancer (CRC) and protect CRC cells against apoptosis. Recently, the analysis of GRP78 polymorphisms has already determined that GRP78 rs391957 polymorphism could predict clinical outcome in CRC patients. Thus, we tested whether GRP78 polymorphisms are related to the risk of CRC. In this study, we detected two GRP78 polymorphisms (rs391957 (C>T) and rs430397 (G>A)) in 414 CRC cases and 502 hospital-based cancer-free healthy controls in Southwest China using a polymerase chain reaction–restriction fragment length polymorphism technique. Compared with the CC genotype, carriers of CT and TT genotypes of rs391957 polymorphism had higher risks of CRC (odds ratio (OR) = 1.39, 95% confidence interval (CI) = 1.06–1.83 for CT genotype and OR = 2.10, 95% CI = 1.06–4.14 for TT genotype, respectively). In CRC cases, the variant T allele was significantly associated with tumor invasion stage (P = 0.030), but not with status of lymph nodes metastasis (P = 0.052). Compared with the GG genotype, carriers of GA and AA genotypes of rs430397 polymorphism had higher risks of CRC (OR = 1.63, 95% CI = 1.23–2.15 for GA genotype and OR = 2.92, 95% CI = 1.23–6.94 for AA genotype, respectively). The rs430397 polymorphism was not associated with the clinicopathological characteristics of CRC. These data provide the first evidence that GRP78 rs391957 and rs430397 polymorphisms could serve as markers to predict the risk of CRC.
|
|
| 10. |
- Feng, Cun-Feng, et al.
(författare)
-
Effects of average degree of network on an order-disorder transition in opinion dynamics
- 2010
-
Ingår i: Chinese Physics B. - : IOPScience. - 1674-1056. ; 19:6, s. 060203-
-
Tidskriftsartikel (refereegranskat)abstract
- We have investigated the influence of the average degree (k) of network on the location of an order-disorder transition in opinion dynamics. For this purpose, a variant of majority rule (VMR) model is applied to Watts–Strogatz (WS) small-world networks and Barabási–Albert (BA) scale-free networks which may describe some non-trivial properties of social systems. Using Monte Carlo simulations, we find that the order–disorder transition point of the VMR model is greatly affected by the average degree (k) of the networks; a larger value of (k) results in a more ordered state of the system. Comparing WS networks with BA networks, we find WS networks have better orderliness than BA networks when the average degree (k) is small. With the increase of (k), BA networks have a more ordered state. By implementing finite-size scaling analysis, we also obtain critical exponents β/ν, γ/ν and 1/ν for several values of average degree (k). Our results may be helpful to understand structural effects on order–disorder phase transition in the context of the majority rule model.
|
|
