Biology subjects

Olalekan, S.

Publications and source records attributed to Olalekan, S..

3 recordsLinked to original sources

bioRxiv2023

Exploring the tumor micro-environment in ovarian cancer histotypes and tumor sites

Ovarian cancer is a highly heterogeneous disease consisting of at least five different histological subtypes with varying clinical features, cells of origin, molecular composition, risk factors, and treatments. While most single-cell studies have focused on High grade serous ovarian cancer, a comprehensive landscape of the constituent cell types and their interactions within the tumor microenvironment are yet to be established in the different ovarian cancer histotypes. Further characterization of tumor progression, metastasis, and various histotypes are also needed to connect molecular signatures to pathological grading for personalized diagnosis and tailored treatment. In this study, we leveraged high-resolution single-cell RNA sequencing technology to elucidate the cellular compositions on 21 solid tumor samples collected from 12 patients with six ovarian cancer histotypes and both primary (ovaries) and metastatic (omentum, rectum) sites. The diverse collection allowed us to deconstruct the histotypes and tumor site-specific expression patterns of cells in the tumor and identify key marker genes and ligand-receptor pairs that are active in the ovarian tumor microenvironment. Our findings can be used in improving precision disease stratification and optimizing treatment options.

cancer biology↗

bioRxiv2022

A molecular atlas of the human postmenopausal fallopian tube and ovary from single-cell RNA and ATAC sequencing

As part of the Human Cell Atlas initiative, we generated transcriptomic (scRNA-seq; 86,708 cells) and regulatory (scATAC-seq; 59,118 cells) profiles of the normal postmenopausal ovary and fallopian tube (FT) at single-cell resolution. In the FT, 22 cell clusters integrated into 11 cell types, including ciliated and secretory epithelial cells, while the ovary had 17 distinct cell clusters defining 6 major cell types. The dominant cell type in both the postmenopausal ovary and FT was stromal cells, which expressed several genes associated with aging. The fimbrial end of the FT had a significant number and variety of immune cells and active communication with the ovary; the ovary contained mostly stromal cells but few immune cells. The epithelial cells of the normal FT expressed multiple ovarian cancer risk-associated genes (CCDC170, RND3, TACC2, STK33, and ADGB). By integrating paired single-cell transcriptomics and chromatin accessibility data we found that the regulatory landscape of the fimbriae was markedly different from the isthmus and ampulla. Intriguingly, several cell types in the FT had comparable gene expression but different transcriptional regulations. Our single-cell transcriptional and regulatory maps allowed us to disentangle the complex cellular makeup of the postmenopausal FT and ovary and will contribute to a better understanding of gynecologic diseases in menopause.

genomics↗

bioRxiv2020

Characterizing the tumor microenvironment of metastatic ovarian cancer by single cell transcriptomics

Epithelial ovarian cancer is a highly heterogenous, metastatic and lethal disease. The presence of CD8+T cells within ovarian tumors is positively associated with overall patient survival. Determining if a patient has T cells that respond to immunotherapies, their characteristics and how they can be manipulated to target cancer cells is an area of intense investigation in cancer therapy. This study determines the cellular composition and the transcriptional state of immune cells in metastatic ovarian cancer samples from patients using single cell RNA sequencing (scRNA-seq). Hierarchical clustering stratified our patient cohort into 2 main groups: 1) a high T cell infiltration (high Tinf) group and 2) a low T cell infiltration (low Tinf) group. To assess the immune response in these patient samples, we performed an unsupervised clustering of the T cell population in each group. The T cell population clustered into 4 and 3 subpopulations in the high Tinf T cell and low Tinf respectively. A granulysin expressing T cell cluster was identified and unique to the High Tinf group. Interestingly, although both groups had resident memory CD8+T (CD8+Trm) cells, only the CD8+Trm cells in the high Tinf group expressed TOX, a recently described transcription factor. TOX confers longevity to T cells within immunosuppressive environment such as cancer. Interestingly, along with TOX+ T cells, we found a unique plasmablast cluster and an IRF8+ macrophage cluster unique to the high Tinf group. Our comprehensive scRNA-seq study provides important insights in elucidating the immune response in ovarian cancer patients.

cancer biology↗