Publications by authors named "Marianna A Zolotovskaia"

Introduction: The differential ratio of nonsynonymous to synonymous nucleotide substitutions (dN/dS) is a common measure of the rate of structural evolution in proteincoding genes. In addition, we recently suggested that the proportion of transposable elements in gene promoters that host functional genomic sites serves as a marker of the rate of regulatory evolution of genes. Such functional genomic regions may include transcription factor binding sites and modified histone binding loci.

View Article and Find Full Text PDF

Cancer chimeric, or fusion, transcripts are thought to most frequently appear due to chromosomal aberrations that combine moieties of unrelated normal genes. When being expressed, this results in chimeric RNAs having upstream and downstream parts relatively to the breakpoint position for the 5'- and 3'-fusion components, respectively. As many other types of cancer mutations, fusion genes can be of either driver or passenger type.

View Article and Find Full Text PDF

The gene encodes the reverse transcriptase subunit of telomerase and is normally transcriptionally suppressed in differentiated human cells but reactivated in cancers where its expression is frequently associated with poor survival prognosis. Here we experimentally assessed the RNA sequencing expression patterns associated with transcription in 1039 human cancer samples of 27 tumor types. We observed a bimodal distribution of expression where ∼27% of cancer samples did not express and the rest showed a bell-shaped distribution.

View Article and Find Full Text PDF
Article Synopsis
  • Normal tissues are crucial for studying gene expression related to diseases, but healthy controls are often obtained only post-mortem, leading researchers to use "normal" tissues next to tumors as controls.
  • A study compared gene expression profiles in tumor-adjacent tissues to those from autopsy-derived healthy tissues, discovering significant differences linked to immune activation, cell signaling pathways, and structural changes.
  • Using a macaque model, researchers identified RNA degradation in lung samples that affected gene expression results, emphasizing the need to consider sample quality and handling in research protocols.
View Article and Find Full Text PDF

The evolution of protein-coding genes has both structural and regulatory components. The first can be assessed by measuring the ratio of non-synonymous to synonymous nucleotide substitutions. The second component can be measured as the normalized proportion of transposable elements that are used as regulatory elements.

View Article and Find Full Text PDF
Article Synopsis
  • DNA repair mechanisms are crucial for maintaining genome integrity and limiting tumor progression, but they can also help tumors survive radiation and chemotherapy treatments.
  • Research analyzed 38 DNA repair pathways across nine cancer types using RNAseq data from various databases, revealing a consistent downregulation of the G2/M checkpoint pathway and low p53 pathway activity in tumors.
  • The study identified that despite most DNA repair pathways being upregulated, key genes associated with the G2/M checkpoint and p53 pathways were significantly disrupted, highlighting their unique roles in cancer development.
View Article and Find Full Text PDF

In gliomas, expression of certain marker genes is strongly associated with survival and tumor type and often exceeds histological assessments. Using a human interactome model, we algorithmically reconstructed 7494 new-type molecular pathways that are centered each on an individual protein. Each single-gene expression and gene-centric pathway activation was tested as a survival and tumor grade biomarker in gliomas and their diagnostic subgroups (IDH mutant or wild type, IDH mutant with 1p/19q co-deletion, MGMT promoter methylated or unmethylated), including the three major molecular subtypes of glioblastoma (proneural, mesenchymal, classical).

View Article and Find Full Text PDF
Article Synopsis
  • - OncoboxPD is an extensive database of human molecular pathways, featuring over 51,000 pathways that map out protein-protein interactions and metabolic reactions, totaling over 361,000 interactions among 64,000 molecules.
  • - It categorizes pathways by biological processes and uses algorithms to annotate pathway nodes, allowing users to determine pathway activation levels based on specific RNA/protein expression profiles.
  • - Users can visualize pathways as static or dynamic graphs, highlight differentially expressed nodes, and generate summary graphs that display the most significant upregulated and downregulated pathways for their comparisons.
View Article and Find Full Text PDF
Article Synopsis
  • Inter-patient molecular heterogeneity in tumors is influencing the development and personalization of anticancer drugs, leading to varied treatment options.
  • A comprehensive analysis of 4,890 tumors revealed that the molecular targets of accepted cancer drugs do not align with tumor heterogeneities across thirteen major cancer types.
  • The study found that clinical recommendations for drug use correlate more with gene expression patterns than mutation patterns, highlighting opportunities for improving targeted therapies, especially in certain cancer types like kidney and ovarian cancers.
View Article and Find Full Text PDF

Carcinogenesis is linked with massive changes in regulation of gene networks. We used high throughput mutation and gene expression data to interrogate involvement of 278 signaling, 72 metabolic, 48 DNA repair and 47 cytoskeleton molecular pathways in cancer. Totally, we analyzed 4910 primary tumor samples with individual cancer RNA sequencing and whole exome sequencing profiles including ~1.

View Article and Find Full Text PDF

Despite the significant achievements in chemotherapy, cancer remains one of the leading causes of death. Target therapy revolutionized this field, but efficiencies of target drugs show dramatic variation among individual patients. Personalization of target therapies remains, therefore, a challenge in oncology.

View Article and Find Full Text PDF

DNA mutations play a crucial role in cancer development and progression. Mutation profiles vary dramatically in different cancer types and between individual tumors. Mutations of several individual genes are known as reliable cancer biomarkers, although the number of such genes is tiny and does not enable differential diagnostics for most of the cancers.

View Article and Find Full Text PDF