scholarly journals Integrative Analysis of DNA Methylation and Gene Expression in Skin Cutaneous Melanoma by Bioinformatic Approaches

Author(s):  
Yan Sun ◽  
Zhilin Wu ◽  
Rui Chen ◽  
Yan Wu ◽  
Yun Lin

Abstract Skin cutaneous melanoma is the most life-threatening skin cancer. Finding key methylation genes of prognostic value is an under-explored but intriguing field in the research of skin cutaneous melanoma. This work is aimed to identify survival related methylated genes and their specific methylation sites in skin cutaneous melanoma via an integrative analysis with bioinformatic approaches. The original data, including gene methylation and expression files, were downloaded from the Cancer Genome Atlas database. Statistical analysis revealed that skin cutaneous melanoma patients with highly expressed and hypomethylated HHEX had a better outcome than patients with lowly-expressed and hypermethylated HHEX. In addition, fifteen methylation sites of HHEX were identified to be significantly correlated with HHEX expression changes. In various pathological stages, the expression levels of HHEX were different, and exhibited a downward trend from stage Ⅰ to stage Ⅳ. Therefore, we speculate that the driven gene HHEX may play an important role in the survival of skin cutaneous melanoma. This finding provides novel epigenetic molecular clues and potential detection targets for early prediction of the prognosis of skin cutaneous melanoma.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauren G. Aoude ◽  
Vanessa F. Bonazzi ◽  
Sandra Brosda ◽  
Kalpana Patel ◽  
Lambros T. Koufariotis ◽  
...  

Abstract Patients with late stage resected cutaneous melanoma have poor overall survival (OS) and experience irreversible adverse events from systemic therapy. There is a clinical need to identify biomarkers to predict outcome. Performing germline/tumour whole-exome sequencing of 44 stage III/IV melanoma patients we identified pathogenic germline mutations in CDKN2A, CDK4, ATM, POLH, MRE11A, RECQL4 and XPC, affecting 7/44 patients. These mutations were associated with poor OS (p = 0.0082). We confirmed our findings in The Cancer Genome Atlas (TCGA) human skin cutaneous melanoma cohort where we identified pathogenic variants in 40/455 patients (p = 0.0203). Combining these cohorts (n = 499) further strengthened these findings showing germline carriers had worse OS (p = 0.0009). Additionally, we determined whether tumour mutation burden (TMB) or BRAF status were prognostic markers of survival. Low TMB rate (< 20 Mut/Mb; p = 0.0034) and BRAF p.V600 mutation (p = 0.0355) were associated with worse progression-free survival. Combining these biomarkers indicated that V600 mutant patients had significantly lower TMB (p = 0.0155). This was confirmed in the TCGA (n = 443, p = 0.0007). Integrative analysis showed germline mutation status conferred the highest risk (HR 5.2, 95% CI 1.72–15.7). Stage IV (HR 2.5, 0.74–8.6) and low TMB (HR 2.3, 0.57–9.4) were similar, whereas BRAF V600 status was the weakest prognostic biomarker (HR 1.5, 95% CI 0.44–5.2).


2021 ◽  
Author(s):  
Xiao-Cheng Wang ◽  
Ya Liu ◽  
Fei-Wu Long ◽  
Liang-Ren Liu ◽  
Chuan-Wen Fan

Background: The relationship between long noncoding RNAs (lncRNAs) and the mRNA stemness index (mRNAsi) in colorectal cancer (CRC) is still unclear. Materials & methods: The mRNAsi, mRNAsi-related lncRNAs and their clinical significance were analyzed by bioinformatic approaches in The Cancer Genome Atlas (TCGA)-COREAD dataset. Results: mRNAsi was negatively related to pathological features but positively related to overall survival and recurrence-free survival in CRC. A five mRNAsi-related lncRNAs prognostic signature was further developed and showed independent prognostic factors related to overall survival in CRC patients, due to the five mRNAsi-related lncRNAs involved in several pathways of the cancer stem cells and malignant cancer cell phenotypes. Conclusion: The present study highlights the potential roles of mRNAsi-related lncRNAs as alternative prognostic markers.


2020 ◽  
Vol 9 (2) ◽  
pp. 411 ◽  
Author(s):  
Feng Liu-Smith ◽  
Yunxia Lu

Background: BRCA1-Associated Protein 1 (BAP1) germline mutations predispose individuals to cancers, including uveal melanoma (UM) and cutaneous melanoma (CM). BAP1 loss is common in UM and is associated with a worse prognosis. BAP1 loss is rare in CM and the outcome is unclear. Methods: UM and CM data was retrieved from The Cancer Genome Atlas (TCGA) database. Cox regression model was performed to examine whether BAP1 mRNA levels or copy number variations were associated with overall survival (OS). Results: BAP1-low mRNA predicted a poor OS in UM (HR = 9.57, 95% CI: 2.82, 32.5) but a contrasting better OS in CM (HR = 0.73, 95% CI: 0.56, 0.95). These results remained unchanged after adjusting for sex, age, and stage in UM and CM, or after adjusting for ulceration or Breslow depth in CM. Additionally, low BAP1 mRNA predicted a better OS in CM patients older than 50 years but not in younger patients. Co-expression and enrichment analysis revealed differential genes and mutations that were correlated with BAP1 expression levels in UM and CM tumors. Conclusions: Low BAP1 mRNA was significantly associated with a better OS in CM patients, in sharp contrast to UM. High BAP1 expression in CM was significantly associated with over-expressed CDK1, BCL2, and KIT at the protein level which may explain the poor OS in this sub-group of patients. Function of BAP1 was largely different in CM and UM despite of a small subset of shared co-expressed genes.


2020 ◽  
Vol 21 (10) ◽  
pp. 3522
Author(s):  
Nair Lopes ◽  
Margareta P. Correia ◽  
Rui Henrique ◽  
Carmen Jerónimo

Oesophageal cancer is a life-threatening disease, accounting for high mortality rates. The poor prognosis of this malignancy is mostly due to late diagnosis and lack of effective therapies for advanced disease. Epigenetic alterations may constitute novel and attractive therapeutic targets, owing to their ubiquity in cancer and their reversible nature. Herein, we offer an overview of the most important studies which compared differences in expression of enzymes that mediate epigenetic alterations between oesophageal cancer and normal mucosa, as well as in vitro data addressing the role of these genes/proteins in oesophageal cancer. Furthermore, The Cancer Genome Atlas database was interrogated for the correlation between expression of these epigenetic markers and standard clinicopathological features. We concluded that most epigenetic players studied thus far are overexpressed in tumours compared to normal tissue. Furthermore, functional assays suggest an oncogenic role for most of those enzymes, supporting their potential as therapeutic targets in oesophageal cancer.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Quan Hong ◽  
Shuqiang Wang ◽  
Shuxin Liu ◽  
Xiangmei Chen ◽  
Guangyan Cai

Clear cell renal cell carcinoma (ccRCC) accounts for 60-70% of renal cell carcinoma (RCC) cases. It is an urgent mission to find more therapeutic targets for advanced ccRCC. Leucine-rich a-2-glycoprotein 1 (LRG1) is a secreted protein associated with a variety of malignancies. Our study focused on the expression and mechanism of LRG1 in ccRCC based on data from The Cancer Genome Atlas (TCGA) and provided primary verification including LRG1 expression detection, LRG1 gene methylation detection, and downstream signaling detection. We found that LRG1 was overexpressed in ccRCC kidney tissue samples, and the methylation level of LRG1 gene was significantly decreased in ccRCC. Moreover, the expression of LRG1 was negatively related to patient survival. Based on our previous study and the verification reported in this article, we propose that demethylation-induced overexpression of LRG1 is likely to accelerate ccRCC progression via the TGF-β pathway.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14300-e14300 ◽  
Author(s):  
Xianling Guo ◽  
Song Gao ◽  
Li Yang ◽  
Juemin Fang ◽  
Guochao Wei ◽  
...  

e14300 Background: Acral and mucosal melanoma are rare subtypes accounting for about 3% of all melanoma cases. The cutaneous melanoma genomic landscape is well defined; however, little is known about the acral and mucosal melanoma mutational spectrum. In this pilot study, we evaluated the genomic and neo-antigen profiles and tumor mutational burden (TMB) from acral and mucosal melanoma patients with the aim of designing personalized vaccines and longitudinally tracking patients’ clinical courses. Methods: Tumor whole exome sequencing and neo-antigen profiling of 5 acral and 3 mucosal melanoma patients at Shanghai Tenth Peoples Hospital, Tongji University, China between April 2018 and January 2019 was performed using YuceBio’s proprietary analytics platform. Watsonä for Genomics, an artificial intelligence decision-support system, was used for variant interpretation and annotation. A comparative analysis was performed on Chinese acral melanoma data with the published Caucasian acral cohort from the Translational Genomics Research Institute (TGen) and The Cancer Genome Atlas (TCGA) predominantly Caucasian cutaneous melanoma data set. Results: TMB in our acral/mucosal melanoma cohort was 2.26/Megabase (Mb) compared to over 20/Mb in published cutaneous melanoma studies. Tumor neo-antigen burden (TNAB) in our group was 1.03 neo-epitopes/Mb. Low TNAB levels were associated with low TMB levels in all tumors. Incidence of BRAF and NRAS mutant cases in our cohort was 0% (0/8) and 13% (1/8) respectively compared to 19% (5/27) and 7% (2/27) of the Caucasian acral population in the TGen dataset. Incidence of BRAF and NRAS mutations in the TCGA cutaneous melanoma dataset was 54% (237/440) and 28% (125/440), respectively. Conclusions: TMB was significantly lower in acral/mucosal than in cutaneous melanoma and may be a surrogate for TNAB. Detection of BRAF and NRAS mutations, the two most prevalent driver mutations in cutaneous melanoma, were significantly lower frequencies in both Chinese and Caucasian acral melanoma patients in this study, suggesting alternate cancer drivers may exist in this subtype. Strategies to address challenges of low TNAB in vaccine development are being explored.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e22066-e22066
Author(s):  
Margaret I Sanchez ◽  
James Michael Grichnik

e22066 Background: Cutaneous melanoma (CM) demonstrates differences in its clinical prevalence in different racial groups. CM generally exhibits a high tumor mutational burden (TMB) and mutually exclusive driving mutations in NRAS, BRAF or KIT. TMB may be driven by different pathways including ultraviolet radiation (UVR), oxidation and deamination. UVR is the most common mutational signature found in CMs, but deamination and oxidation are also present. Methods: We analyzed 321 CMs exome data from The Cancer Genome Atlas network. BRAF, NRAS, KIT and those without (WT) were used to divide the melanomas. Germline SNPs with racial information (Caucasian, African and Asian) that were enriched in melanomas with a particular driving mutation were identified. Results: We compared the 3 racial groups across the 4 driving mutation types, Asian SNPs were significantly higher in KIT, African in WT and Caucasian in BRAF and NRAS. The melanomas were also evaluated by the type of substitution mutations including CC > TT for UV, G > T for oxidative damage and (G/A)C (G) > (G/A)T(G) for deamination. UV and deamination appeared inversely proportional, while oxidative damage appeared to be independent. UV signal was more prominent in BRAF and NRAS groups. KIT had a greater percentage of deamination while WT revealed more oxidative damage. We further compared UV and non-UV (CC > TT absence) KIT subgroups for racial differences. Asian SNPs were greatly increased in non-UV subgroup whereas Caucasian SNPs were in UV subgroup. Further, the non-UV KIT subgroup was divided into deamination and oxidative damage subgroups to compare racial differences. Deamination was significantly increased in Asians whereas oxidative damage was higher in Caucasians. In the case of the WT group, African SNPs were significantly higher in the non UV subgroup and were primarily correlated with oxidative damage. Conclusions: This study suggests that racial genetic background may predispose the distinctive mutational and genetic environments of melanoma development.


Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 604 ◽  
Author(s):  
Wang ◽  
Wu ◽  
Ma

Prognosis modeling plays an important role in cancer studies. With the development of omics profiling, extensive research has been conducted to search for prognostic markers for various cancer types. However, many of the existing studies share a common limitation by only focusing on a single cancer type and suffering from a lack of sufficient information. With potential molecular similarity across cancer types, one cancer type may contain information useful for the analysis of other types. The integration of multiple cancer types may facilitate information borrowing so as to more comprehensively and more accurately describe prognosis. In this study, we conduct marginal and joint integrative analysis of multiple cancer types, effectively introducing integration in the discovery process. For accommodating high dimensionality and identifying relevant markers, we adopt the advanced penalization technique which has a solid statistical ground. Gene expression data on nine cancer types from The Cancer Genome Atlas (TCGA) are analyzed, leading to biologically sensible findings that are different from the alternatives. Overall, this study provides a novel venue for cancer prognosis modeling by integrating multiple cancer types.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ao Yuan ◽  
Tianmin Wu ◽  
Hong-Bin Fang ◽  
Ming T. Tan

AbstractIn integrative analysis parametric or nonparametric methods are often used. The former is easier for interpretation but not robust, while the latter is robust but not easy to interpret the relationships among the different types of variables. To combine the advantages of both methods and for flexibility, here a system of semiparametric projection non-linear regression models is proposed for the integrative analysis, to model the innate coordinate structure of these different types of data, and a diagnostic tool is constructed to classify new subjects to the case or control group. Simulation studies are conducted to evaluate the performance of the proposed method, and shows promising results. Then the method is applied to analyze a real omics data from The Cancer Genome Atlas study, compared the results with those from the similarity network fusion, another integrative analysis method, and results from our method are more reasonable.


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