Comprehensive analysis of somatic copy number alterations in clear cell renal cell carcinoma

Vertebrate Cell Differentiation, Evolution, and Diseases: The Vertebrate-Specific Developmental Potential Guardians VENTX/NANOG and POU5/OCT4 Enter the Stage

During vertebrate development, embryonic cells pass through a continuum of transitory pluripotent states that precede multi-lineage commitment and morphogenesis. Such states are referred to as “refractory/naïve” and “competent/formative” pluripotency. The molecular mechanisms maintaining refractory pluripotency or driving the transition to competent pluripotency, as well as the cues regulating multi-lineage commitment, are evolutionarily conserved. Vertebrate-specific “Developmental Potential Guardians” (vsDPGs; i.e., VENTX/NANOG, POU5/OCT4), together with MEK1 (MAP2K1), coordinate the pluripotency continuum, competence for multi-lineage commitment and morphogenesis in vivo. During neurulation, vsDPGs empower ectodermal cells of the neuro-epithelial border (NEB) with multipotency and ectomesenchyme potential through an “endogenous reprogramming” process, giving rise to the neural crest cells (NCCs). Furthermore, vsDPGs are expressed in undifferentiated-bipotent neuro-mesodermal progenitor cells (NMPs), which participate in posterior axis elongation and growth. Finally, vsDPGs are involved in carcinogenesis, whereby they confer selective advantage to cancer stem cells (CSCs) and therapeutic resistance. Intriguingly, the heterogenous distribution of vsDPGs in these cell types impact on cellular potential and features. Here, we summarize the findings about the role of vsDPGs during vertebrate development and their selective advantage in evolution. Our aim to present a holistic view regarding vsDPGs as facilitators of both cell plasticity/adaptability and morphological innovation/variation. Moreover, vsDPGs may also be at the heart of carcinogenesis by allowing malignant cells to escape from physiological constraints and surveillance mechanisms.

Integrated Multi-Omics Analysis Identified PTPRG and CHL1 as Key Regulators of Immunophenotypes in Clear Cell Renal Cell Carcinoma(ccRCC)

Despite the increasing importance and status of immune checkpoint blockade (ICB), little is known about the underlying molecular mechanisms determining the target clear cell renal cell carcinoma (ccRCC) population. In this study, we screened out 6 immune cells strongly correlated with expression levels of PD-L1 and IFN-γ based on the ccRCC samples extracted from GSE and TCGA data sets. By performing unsupervised clustering and lasso regression analysis, we grouped the ccRCC into 4 clusters and selected the two most distinct sub-clusters for further investigation-cluster A1 and B1. Next, we compared the two clusters in terms of mRNA, somatic mutations, copy number variations, DNA methylation, miRNA, lncRNA and constructed the differentially expressed genes (DEGs) hub by combing together the previous results at levels of DNA methylation, miRNA, and lncRNA. PTPRG and CHL1 were identified as key nodes in the regulation hub of immunophenotypes in ccRCC patients. Finally, we established the prognosis model by using Lasso-Cox regression and Kaplan-Meier analysis, recognizing WNT2, C17orf66, and PAEP as independent significant risk factors while IRF4 as an independent protective factor.

Cribriform type adenocarcinoma of the colorectum: comprehensive molecular analyses of a distinctive histologic subtype of colorectal cancer

Colorectal adenocarcinoma (CRA) is characterized by marked heterogeneity and may be composed of an admixture of various histologic patterns, including well-formed gland and cribriform types. Although tumors displaying a prominent or predominant cribriform feature are frequently found in CRA, this type may contain specific histologic variants with a characteristic molecular alteration. We investigated the molecular features of 51 primary CRAs with a predominant cribriform histology using array-based analyses (somatic copy number alterations [SCNA]; mRNA expression). Mutations (TP53, KRAS, PIK3CA and BRAF) and DNA methylation status were also analyzed. The crypt isolation method was used to obtain isolated tumor glands of each type separately. All patients were classified by their CRA histologic subtype into two groups: well-formed gland and cribriform. Next, we performed cluster analysis to stratify SCNA and mRNA expression patterns between the two subtypes. Two distinctive subgroups were stratified based on patterns of SCNA and mRNA expression and were correlated with each histologic subtype. The cribriform type was characterized by a high frequency of SCNA compared with that of the well-formed gland type and was closely associated with the expression of specific mRNAs. In addition, the frequency of KRAS mutation was significantly higher in the cribriform type than in the well-formed gland type. Finally, there was no difference in DNA methylation status between the two subtypes. Overall, these data suggest that the cribriform type provides important insights into colorectal carcinogenesis, suggesting specific potential histologic implications based on the molecular profile.

Analysis of somatic copy number alterations in biliary tract carcinoma using a single nucleotide polymorphism array

Aim:

Biliary tract carcinoma (BTC), including gall bladder carcinoma (GBC) and biliary duct carcinoma (BDC), has a poor prognosis. Comprehensive genomic profiling has important roles in evaluation of the carcinogenesis of BTC.

Materials & methods:

We examined somatic copy number alterations (SCNAs) using a single nucleotide polymorphism array system to analyze 36 BTC samples (11 GBCs and 25 BDCs).

Results:

In hierarchical cluster analysis, two clusters were identified (subgroup 1 with low SCNAs and subgroup 2 with high SCNAs). GBC was predominant in subgroup 1, whereas BDC was predominant in subgroup 2, suggesting that GBC and BDC had different genetic backgrounds in terms of SCNAs.

Conclusion:

These findings could be helpful for establishing the molecular carcinogenesis of BTCs.

Biliary tract carcinoma, including gall bladder carcinoma (GBC) and biliary duct carcinoma (BDC), has a poor prognosis. Comprehensive genomic (single nucleotide polymorphism-array) profiling plays important roles in evaluation of the carcinogenesis of biliary tract carcinoma. In the hierarchical cluster analysis, two clusters were identified (subgroup 1 with low somatic copy number alterations [SCNAs] and subgroup 2 with high SCNAs); GBC was found to be predominant in subgroup 1, whereas BDC was predominant in subgroup 2. These findings suggested that GBC and BDC had different genetic backgrounds in terms of SCNAs.

A genome-wide analysis of the molecular alterations occurring in the adenomatous and carcinomatous components of the same tumor based on the adenoma-carcinoma sequence

Identification of molecular alterations occurring in the adenomatous and carcinomatous components within the same tumor would greatly enhance understanding of the neoplastic progression of colorectal cancer. We examined somatic copy number alterations (SCNAs) and mRNA expression at the corresponding loci involved in the adenoma–carcinoma sequence in the isolated adenomatous and cancer glands of the same tumor in 15 cases of microsatellite‐stable “carcinoma in adenoma,” using genome‐wide SNP and global gene expression arrays. Multiple copy‐neutral loss of heterozygosity events were detected at 4q13.2, 15q15.1, and 14q24.3 in the adenomatous component and at 4q13.2, 15q15.1, and 14q24.3 in the carcinomatous component. There were significant differences in the copy number (CN) gain frequencies at 20q11.21–q13.33, 8q13.3, 8p23.1, and 8q21.2–q22.2 between the adenomatous and carcinomatous components. Finally, we found a high frequency of five genotypes involving CN gain with upregulated expression of the corresponding gene (RPS21, MIR3654, RSP20, SNORD54, or ASPH) in the carcinomatous component, whereas none of these genotypes were detected in the adenomatous component. This finding is interesting in that CN gain with upregulated gene expression may enhance gene function and play a crucial role in the progression of an adenoma into a carcinomatous lesion.

A genome-wide study of the relationship between chromosomal abnormalities and gene expression in colorectal tumors

The role of somatic copy number alterations (SCNAs) that occur in colorectal tumors is poorly understood. SCNAs are correlated with corresponding gene expression changes that may contribute to neoplastic progression. Thus, we examined SCNAs and the expression of messenger RNAs (mRNAs) located at corresponding loci in colorectal neoplasia, a progression model of human neoplasm. We used 42 colorectal neoplastic samples, including adenomas, intramucosal cancers (IMC) and invasive colorectal cancers (CRC) that were microsatellite stable (MSS) using a genome-wide SNP array and gene expression array (first cohort). In addition, validation analyses were examined (37 colorectal neoplasias). None of the mRNAs with a corresponding SCNA was found in the adenomas. However, three mRNAs, including ARFGEF2 at 20q13.13, N4BP2L2 at 13q13.1 and OLFM4 at 13q14.3 with a copy number (CN) gain at the corresponding locus were upregulated in IMCs of the first cohort. Moreover, upregulated expression of ARFGEF2 and OLFM4 was upregulated in the validation analysis. Finally, 28 mRNAs with gains of corresponding loci were pooled in invasive CRC of the first cohort. The mRNAs, including ACSS2 (20q11.22), DDX27 (20q13.13), MAPRE1 (20q11.21), OSBPL2 (20q11.22) and PHF20 (20q11.22-q11.23) with CN gains of the corresponding loci were identified in 28 mRNAs. Four of these mRNAs (DDX27, MAPRE1, OSBPL2 and PHF20) were upregulated in the invasive CRC in the validation analysis. We conclude that specific 13q and 22q CN gains with gene expression changes in the corresponding loci may play an important role in IMC cells' progression into invasive CRC.

Comprehensive analysis of somatic copy number alterations in clear cell renal cell carcinoma

Somatic copy number alterations (SCNAs) are important biological characteristics that can identify genome-wide alterations in renal cell carcinoma (RCC). Recent studies have shown that SCNAs have potential value for determining the prognosis of RCC. We examined SCNAs using the Affymetrix platform to analyze samples from 59 patients with clear cell RCCs (ccRCCs) including first cohort (30 cases) and second cohort (validation cohort, 29 cases). We stratified SCNAs in the ccRCCs using a hierarchical cluster analysis based on SCNA types, including gain, loss of heterozygosity (LOH), copy neutral LOH, mosaic, and mixed types. In this way, the examined two cohorts were categorized into two subgroups (1 and 2). Although the frequency of mixed type was higher in subgroup 1 than in subgroup 2 in the two cohorts, the association did not reach statistical significance. There was a significant difference in the frequency of metachronous metastasis between subgroups 1 and 2 (subgroup 2 > 1). In addition, subgroup 2 was retained in multivariate analysis of both cohorts. We examined whether there were specific alleles differing between subgroups 1 and 2 in both cohorts. We found that there was indeed a statistically significant difference in the 3p mixed types. Among the 3p mixed type, we found that 3p24.3 mixed type was inversely correlated with the presence of metachronous metastasis in ccRCC. The association was also retained in multivariate analysis in second cohort. We suggest that the 3p24.3 mixed type may be a novel marker to predict a favorable prognosis in ccRCC.