scholarly journals Bioinformatics workflows for genomic analysis of tumors from Patient Derived Xenografts (PDX): challenges and guidelines

2018 ◽  
Author(s):  
Xing Yi Woo ◽  
Anuj Srivastava ◽  
Joel H. Graber ◽  
Vinod Yadav ◽  
Vishal Kumar Sarsani ◽  
...  
Keyword(s):  
Copy Number ◽  
Somatic Mutations ◽  
Simulated Data ◽  
Genomic Analysis ◽  
Human Tumors ◽  
The Cancer Genome Atlas ◽  
Accurate Identification ◽  
Human Sequence ◽  
Analytical Approaches ◽  
Bioinformatics Workflows

AbstractBioinformatics workflows for analyzing genomic data obtained from xenografted tumor (e.g., human tumors engrafted in a mouse host) must address several challenges, including separating mouse and human sequence reads and accurate identification of somatic mutations and copy number aberrations when paired normal DNA from the patient is not available. We report here data analysis workflows that address these challenges and result in reliable identification of somatic mutations, copy number alterations, and transcriptomic profiles of tumors from patient derived xenograft models. We validated our analytical approaches using simulated data and by assessing concordance of the genomic properties of xenograft tumors with data from primary human tumors in The Cancer Genome Atlas (TCGA). The commands and parameters for the workflows are available at https://github.com/TheJacksonLaboratory/PDX-Analysis-Workflows.

scholarly journals Data Fusion Techniques for the Integration of Multi-Domain Genomic Data from Uveal Melanoma

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1434 ◽  
Author(s):  
Max Pfeffer ◽  
André Uschmajew ◽  
Adriana Amaro ◽  
Ulrich Pfeffer
Keyword(s):  
Gene Expression ◽  
Data Fusion ◽  
Uveal Melanoma ◽  
Copy Number ◽  
Somatic Mutations ◽  
Genomic Data ◽  
The Cancer Genome Atlas ◽  
Driver Genes ◽  
Discrimination Power ◽  
Value Decomposition

Uveal melanoma (UM) is a rare cancer that is well characterized at the molecular level. Two to four classes have been identified by the analyses of gene expression (mRNA, ncRNA), DNA copy number, DNA-methylation and somatic mutations yet no factual integration of these data has been reported. We therefore applied novel algorithms for data fusion, joint Singular Value Decomposition (jSVD) and joint Constrained Matrix Factorization (jCMF), as well as similarity network fusion (SNF), for the integration of gene expression, methylation and copy number data that we applied to the Cancer Genome Atlas (TCGA) UM dataset. Variant features that most strongly impact on definition of classes were extracted for biological interpretation of the classes. Data fusion allows for the identification of the two to four classes previously described. Not all of these classes are evident at all levels indicating that integrative analyses add to genomic discrimination power. The classes are also characterized by different frequencies of somatic mutations in putative driver genes (GNAQ, GNA11, SF3B1, BAP1). Innovative data fusion techniques confirm, as expected, the existence of two main types of uveal melanoma mainly characterized by copy number alterations. Subtypes were also confirmed but are somewhat less defined. Data fusion allows for real integration of multi-domain genomic data.

Outlier reset CUSUM for the exploration of copy number alteration data

2015 ◽  
Vol 14 (4) ◽  
Author(s):  
Yinglei Lai ◽  
Joseph L. Gastwirth
Keyword(s):  
Ovarian Cancer ◽  
Copy Number ◽  
Copy Number Alteration ◽  
Simulated Data ◽  
Threshold Value ◽  
The Cancer Genome Atlas ◽  
Research Network ◽  
Data Set ◽  
Cusum Procedure ◽  
Truncated Normal

AbstractCopy number alteration (CNA) data have been collected to study disease related chromosomal amplifications and deletions. The CUSUM procedure and related plots have been used to explore CNA data. In practice, it is possible to observe outliers. Then, modifications of the CUSUM procedure may be required. An outlier reset modification of the CUSUM (ORCUSUM) procedure is developed in this paper. The threshold value for detecting outliers or significant CUSUMs can be derived using results for sums of independent truncated normal random variables. Bartel’s non-parametric test for autocorrelation is also introduced to the analysis of copy number variation data. Our simulation results indicate that the ORCUSUM procedure can still be used even in the situation where the degree of autocorrelation level is low. Furthermore, the results show the outlier’s impact on the traditional CUSUM’s performance and illustrate the advantage of the ORCUSUM’s outlier reset feature. Additionally, we discuss how the ORCUSUM can be applied to examine CNA data with a simulated data set. To illustrate the procedure, recently collected single nucleotide polymorphism (SNP) based CNA data from The Cancer Genome Atlas (TCGA) Research Network is analyzed. The method is applied to a data set collected in an ovarian cancer study. Three cytogenetic bands (cytobands) are considered to illustrate the method. The cytobands 11q13 and 9p21 have been shown to be related to ovarian cancer. They are presented as positive examples. The cytoband 3q22, which is less likely to be disease related, is presented as a negative example. These results illustrate the usefulness of the ORCUSUM procedure as an exploratory tool for the analysis of SNP based CNA data.

Molecular Genetics of Endometrial Carcinoma

2019 ◽  
Vol 14 (1) ◽  
pp. 339-367 ◽  
Author(s):  
Daphne W. Bell ◽  
Lora Hedrick Ellenson
Keyword(s):  
Endometrial Carcinoma ◽  
Copy Number ◽  
Clear Cell ◽  
Genomic Analysis ◽  
Molecular Classification ◽  
The United States ◽  
The Cancer Genome Atlas ◽  
Therapeutic Implications ◽  
Molecular Features ◽  
Endometrial Carcinomas

Endometrial cancer is the most commonly diagnosed gynecologic malignancy in the United States. Endometrioid endometrial carcinomas constitute approximately 85% of newly diagnosed cases; serous carcinomas represent approximately 3–10% of diagnoses; clear cell carcinoma accounts for <5% of diagnoses; and uterine carcinosarcomas are rare, biphasic tumors. Longstanding molecular observations implicate PTEN inactivation as a major driver of endometrioid carcinomas; TP53 inactivation as a major driver of most serous carcinomas, some high-grade endometrioid carcinomas, and many uterine carcinosarcomas; and inactivation of either gene as drivers of some clear cell carcinomas. In the past decade, targeted gene and exome sequencing have uncovered additional pathogenic aberrations in each histotype. Moreover, an integrated genomic analysis by The Cancer Genome Atlas (TCGA) resulted in the molecular classification of endometrioid and serous carcinomas into four distinct subgroups, POLE (ultramutated), microsatellite instability (hypermutated), copy number low (endometrioid), and copy number high (serous-like). In this review, we provide an overview of the major molecular features of the aforementioned histopathological subtypes and TCGA subgroups and discuss potential prognostic and therapeutic implications for endometrial carcinoma.

scholarly journals Inactivating Mutations of the IK Gene Weaken Ku80/Ku70-Mediated DNA Repair and Sensitize Endometrial Cancer to Chemotherapy

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2487
Author(s):  
Chao Gao ◽  
Guangxu Jin ◽  
Elizabeth Forbes ◽  
Lingegowda S. Mangala ◽  
Yingmei Wang ◽  
...  
Keyword(s):  
Dna Repair ◽  
Endometrial Cancer ◽  
Protein Interactions ◽  
Somatic Mutations ◽  
The Cancer Genome Atlas ◽  
Response To Chemotherapy ◽  
Tcga Dataset ◽  
Inactivating Mutations

IK is a mitotic factor that promotes cell cycle progression. Our previous investigation of 271 endometrial cancer (EC) samples from the Cancer Genome Atlas (TCGA) dataset showed IK somatic mutations were enriched in a cluster of patients with high-grade and high-stage cancers, and this group had longer survival. This study provides insight into how IK somatic mutations contribute to EC pathophysiology. We analyzed the somatic mutational landscape of IK gene in 547 EC patients using expanded TCGA dataset. Co-immunoprecipitation and mass spectrometry were used to identify protein interactions. In vitro and in vivo experiments were used to evaluate IK’s role in EC. The patients with IK-inactivating mutations had longer survival during 10-year follow-up. Frameshift and stop-gain were common mutations and were associated with decreased IK expression. IK knockdown led to enrichment of G2/M phase cells, inactivation of DNA repair signaling mediated by heterodimerization of Ku80 and Ku70, and sensitization of EC cells to cisplatin treatment. IK/Ku80 mutations were accompanied by higher mutation rates and associated with significantly better overall survival. Inactivating mutations of IK gene and loss of IK protein expression were associated with weakened Ku80/Ku70-mediated DNA repair, increased mutation burden, and better response to chemotherapy in patients with EC.

scholarly journals Low intratumor heterogeneity correlates with increased response to PD-1 blockade in renal cell carcinoma

2020 ◽  
Vol 12 ◽  
pp. 175883592097711
Author(s):  
Xia Ran ◽  
Jinyuan Xiao ◽  
Yi Zhang ◽  
Huajing Teng ◽  
Fang Cheng ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Checkpoint Inhibitors ◽  
Simulated Data ◽  
The Cancer Genome Atlas ◽  
Intratumor Heterogeneity ◽  
Cell Renal Cell Carcinoma ◽  
Immune Activity

Background: Intratumor heterogeneity (ITH) has been shown to be inversely associated with immune infiltration in several cancers including clear cell renal cell carcinoma (ccRCC), but it remains unclear whether ITH is associated with response to immunotherapy (e.g. PD-1 blockade) in ccRCC. Methods: We quantified ITH using mutant-allele tumor heterogeneity, investigated the association of ITH with immune parameters in patients with ccRCC ( n = 336) as well as those with papillary RCC (pRCC, n = 280) from The Cancer Genome Atlas, and validations were conducted in patients with ccRCC from an independent cohort ( n = 152). The relationship between ITH and response to anti-PD-1 immunotherapy was explored in patients with metastatic ccRCC from a clinical trial of anti-PD-1 therapy ( n = 35), and validated in three equal-size simulated data sets ( n = 60) generated by random sampling with replacement based on this clinical trial cohort. Results: In ccRCC, low ITH was associated with better survival, more reductions in tumor burden, and clinical benefit of anti-PD-1 immunotherapy through modulating immune activity involving more neoantigens, elevated expression of HLA class I genes, and higher abundance of dendritic cells. Furthermore, we found that the association between the level of ITH and response to PD-1 blockade was independent of the mutation status of PBRM1 and that integrating both factors performed better than the individual predictors in predicting the benefit of anti-PD-1 immunotherapy in ccRCC patients. In pRCC, increased immune activity was also observed in low- versus high-ITH tumors, including higher neoantigen counts, increased abundance of monocytes, and decreased expression of PD-L1 and PD-L2. Conclusions: ITH may be helpful in the identification of patients who could benefit from PD-1 blockade in ccRCC, and even in pRCC where no genomic metrics has been found to correlate with response to immune checkpoint inhibitors.

scholarly journals HiCancer: accurate and complete cancer genome phasing with Hi-C reads

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weihua Pan ◽  
Desheng Gong ◽  
Da Sun ◽  
Haohui Luo
Keyword(s):  
Copy Number ◽  
Somatic Mutations ◽  
Copy Number Variations ◽  
Cancer Genome ◽  
Structural Variations ◽  
Genome Map ◽  
Linkage Information ◽  
Suboptimal Solution ◽  
Allelic Copy Number ◽  
Very High

AbstractDue to the high complexity of cancer genome, it is too difficult to generate complete cancer genome map which contains the sequence of every DNA molecule until now. Nevertheless, phasing each chromosome in cancer genome into two haplotypes according to germline mutations provides a suboptimal solution to understand cancer genome. However, phasing cancer genome is also a challenging problem, due to the limit in experimental and computational technologies. Hi-C data is widely used in phasing in recent years due to its long-range linkage information and provides an opportunity for solving the problem of phasing cancer genome. The existing Hi-C based phasing methods can not be applied to cancer genome directly, because the somatic mutations in cancer genome such as somatic SNPs, copy number variations and structural variations greatly reduce the correctness and completeness. Here, we propose a new Hi-C based pipeline for phasing cancer genome called HiCancer. HiCancer solves different kinds of somatic mutations and variations, and take advantage of allelic copy number imbalance and linkage disequilibrium to improve the correctness and completeness of phasing. According to our experiments in K562 and KBM-7 cell lines, HiCancer is able to generate very high-quality chromosome-level haplotypes for cancer genome with only Hi-C data.

scholarly journals Genomic Analysis of Response to Neoadjuvant Chemotherapy in Esophageal Adenocarcinoma

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3394
Author(s):  
Fereshteh Izadi ◽  
Benjamin Sharpe ◽  
Stella Breininger ◽  
Maria Secrier ◽  
Jane Gibson ◽  
...  
Keyword(s):  
Neoadjuvant Chemotherapy ◽  
Esophageal Adenocarcinoma ◽  
Copy Number ◽  
Tumor Regression ◽  
Locally Advanced ◽  
Genomic Analysis ◽  
Tumor Regression Grade ◽  
Comparative Genomic ◽  
Mutation Burden ◽  
Response To Neoadjuvant Chemotherapy

Neoadjuvant therapy followed by surgery is the standard of care for locally advanced esophageal adenocarcinoma (EAC). Unfortunately, response to neoadjuvant chemotherapy (NAC) is poor (20–37%), as is the overall survival benefit at five years (9%). The EAC genome is complex and heterogeneous between patients, and it is not yet understood whether specific mutational patterns may result in chemotherapy sensitivity or resistance. To identify associations between genomic events and response to NAC in EAC, a comparative genomic analysis was performed in 65 patients with extensive clinical and pathological annotation using whole-genome sequencing (WGS). We defined response using Mandard Tumor Regression Grade (TRG), with responders classified as TRG1–2 (n = 27) and non-responders classified as TRG4–5 (n =38). We report a higher non-synonymous mutation burden in responders (median 2.08/Mb vs. 1.70/Mb, p = 0.036) and elevated copy number variation in non-responders (282 vs. 136/patient, p < 0.001). We identified copy number variants unique to each group in our cohort, with cell cycle (CDKN2A, CCND1), c-Myc (MYC), RTK/PIK3 (KRAS, EGFR) and gastrointestinal differentiation (GATA6) pathway genes being specifically altered in non-responders. Of note, NAV3 mutations were exclusively present in the non-responder group with a frequency of 22%. Thus, lower mutation burden, higher chromosomal instability and specific copy number alterations are associated with resistance to NAC.

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