research.csv

Tracing lineages and studying human development;<p>Tracing cell lineages is fundamental for understanding the rules governing development in multicellular organisms and delineating complex biological processes involving the differentiation of multiple cell types with distinct lineage hierarchies. In humans, experimental lineage tracing is unethical, and one has to rely on natural-mutation markers that are created within cells as they proliferate and age. We have demonstrated that it is now possible to trace lineages in normal, noncancerous cells with a variety of data types using natural variations in the nuclear and mitochondrial DNA. In our lab we are studying lineage ancestry in the earliest stages of human development. It is also apparent that the scientific community is on the verge of being able to make a comprehensive and detailed cell lineage map of human embryonic and fetal development. We intend to contribute to that knowledge.</p>;lineage.png
Single cell studies;<p>Single-cell sequencing is the ultimate way to study somatic mosaicism in healthy tissues and in cancer. However, due to the scarcity of DNA in a single cell, an amplification process is required. Such amplifications can be achieved via clonal expansion, in which a single cell is cultured to produce a colony, and via in vitro whole genome amplification (WGA), in which DNA is amplified by using polymerases. We are currently formulating strategies for the quality control of WGA and to distinguish signal from noise that may be introduced during cell culture or DNA amplification, as well as developing approaches to estimate the contributions of signal and noise when they cannot be distinguished unambiguously.</p>;singlecell3.jpg
Cancer genomics;<p>During the past decade, high-throughput next-generation technologies coupled with computational algorithms have enabled us to better understand the biology of cancer as well as the molecular underpinnings of its development and progression. Numerous functionally significant point mutations as well as structural alterations have been identified in several types and subtypes of cancers that illustrate the diverse landscape of the cancer genome. In our laboratory, we focus on the discovery and analysis of somatic point mutations and structural alterations, including deletions, duplications, and copy number changes, in colon cancer and glioma. We are especially interested in understanding the relationship between patterns of genetic alterations and modes of evolution of cancer, as well as molecular differences between cancer-free and cancer-adjacent polyps.</p>;polyp2.png
CNV and CNA analysis;<p>Copy number variation (CNV) in the genome is a complex phenomenon that remains incompletely understood. Frequent in cancers, somatic copy number alterations (CNA) have been related to cancer susceptibility, cancer progression and invasiveness, individual response to the treatment, and patients’ quality of life after treatment. The detection of CNVs and CNAs is important to address a wide spectrum of clinical and scientific questions. Research in our laboratory is focused on the discovery and analysis of CNVs and CNAs along with their relevance to diseases. We have developed and continually improved a method, CNVnator/CNVpytor, for CNV discovery and genotyping from a read-depth analysis of personal genome or cancer sequencing that currently ranks among the best, most widely used methods for CNV analysis.</p>;cnvpytor2.jpg
Variant function;<p>Simultaneous advances in genomics (i.e., in variant discovery), epigenomics, and functional genomics (i.e., emergence of ChiP-seq, ATAC-seq, Hi-C, and RNA-seq techniques) provide opportunities to study both the origins and consequences of genomic variants. We are interested in understanding various epigenomic properties that predispose mutational processes generating single nucleotide variation (SNV) and structural variation (SV). Inversely, germline and somatic variants affect genome function. However, because many of those variants occur in non-coding regions of the genome, their effects remain poorly understood. In response, our laboratory is actively working to elucidate such effects with a particular focus on variants contributing to neuro-developmental disorders such as autism spectrum disorders and Tourette syndrome.</p>;function2.png
Analysis of mosaic variations in human;<p>Mutations in DNA that accumulate during the lifespan of each individual result in mosaic bodies, in which each cell has unique variants in the genome. That phenomenon is called somatic mosaicism. Despite the prevalence of somatic mosaicism, studying it has been limited by the lack of means to detect such variants at the level of single cells. Dropping price of sequencing and recent advances in single-cell genomics, however, make such research possible. Our group develops computational methods for precisely detecting somatic mosaic variants by harnessing new experimental approaches, including clonal expansion and whole genome amplification. By applying those methods to human samples, we aim to answer questions about the origin, spread, and consequence of mosaic mutations, which involves determining mutation rates, differences in the number and pattern of mutations between tissues and ages, relevance of the mutation to diseases and aging. Our group is part of the Somatic Mosaicism Across Human Tissues (SMaHT) project.</p>;mosaic2.png