Browsing by Author "Selman, Bryce"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    FAM83A is a potential biomarker for breast cancer initiation
    (Springer, 2022-02-19) Marino, Natascia; German, Rana; Podicheti, Ram; Rockey, Pam; Sandusky, George E.; Temm, Constance J.; Nakshatri, Harikrishna; Addison, Rebekah J.; Selman, Bryce; Althouse, Sandra K.; Storniolo , Anna Maria V.; Medicine, School of Medicine
    Background Family with sequence similarity 83 member A (FAM83A) presents oncogenic properties in several cancers including breast cancer. Recently, we reported FAM83A overexpression in normal breast tissues from women at high risk of breast cancer. We now hypothesize that FAM83A is a key factor in breast cancer initiation. Methods Immunohistochemical staining was used to evaluate FAM83A protein levels in both a normal breast tissue microarray (TMA, N = 411) and a breast tumor TMA (N = 349). EGFR staining and its correlation with FAM83A expression were also assessed. Lentivirus-mediated manipulation of FAM83A expression in primary and hTERT-immortalized breast epithelial cells was employed. Biological and molecular alterations upon FAM83A overexpression/downregulation and FAM83A’s interaction partners were investigated. Results TMA analysis revealed a 1.5-fold increase in FAM83A expression level in breast cancer cases as compared with normal breast tissues (p < 0.0001). FAM83A protein expression was directly correlated with EGFR level in both normal and breast cancer tissues. In in vitro assays, exogenous expression of FAM83A in either primary or immortalized breast epithelial cells promoted cell viability and proliferation. Additionally, Ingenuity Pathway Analysis (IPA) revealed that FAM83A overexpression in primary cells affected the expression of genes involved in cellular morphology and metabolism. Mass spectrometry analysis identified DDX3X and LAMB3 as potential FAM83A interaction partners in primary cells, while we detected FAM83A interaction with cytoskeleton reorganization factors, including LIMA1, MYH10, PLEC, MYL6 in the immortalized cells. Conclusions This study shows that FAM83A promotes metabolic activation in primary breast epithelial cells and cell proliferation in both primary and immortalized cells. These findings support its role in early breast oncogenesis.
  • Thumbnail Image
    Item
    Loss of Dnmt3a impairs hematopoietic homeostasis and myeloid cell skewing via the PI3Kinase pathway
    (The American Society for Clinical Investigation, 2023-05-08) Palam, Lakshmi Reddy; Ramdas, Baskar; Pickerell, Katelyn; Pasupuleti, Santhosh Kumar; Kanumuri, Rahul; Cesarano, Annamaria; Szymanski, Megan; Selman, Bryce; Dave, Utpal P.; Sandusky, George; Perna, Fabiana; Paczesny, Sophie; Kapur, Reuben; Pediatrics, School of Medicine
    Loss-of-function mutations in the DNA methyltransferase 3A (DNMT3A) are seen in a large number of patients with acute myeloid leukemia (AML) with normal cytogenetics and are frequently associated with poor prognosis. DNMT3A mutations are an early preleukemic event, which - when combined with other genetic lesions - result in full-blown leukemia. Here, we show that loss of Dnmt3a in hematopoietic stem and progenitor cells (HSC/Ps) results in myeloproliferation, which is associated with hyperactivation of the phosphatidylinositol 3-kinase (PI3K) pathway. PI3Kα/β or the PI3Kα/δ inhibitor treatment partially corrects myeloproliferation, although the partial rescue is more efficient in response to the PI3Kα/β inhibitor treatment. In vivo RNA-Seq analysis on drug-treated Dnmt3a-/- HSC/Ps showed a reduction in the expression of genes associated with chemokines, inflammation, cell attachment, and extracellular matrix compared with controls. Remarkably, drug-treated leukemic mice showed a reversal in the enhanced fetal liver HSC-like gene signature observed in vehicle-treated Dnmt3a-/- LSK cells as well as a reduction in the expression of genes involved in regulating actin cytoskeleton-based functions, including the RHO/RAC GTPases. In a human PDX model bearing DNMT3A mutant AML, PI3Kα/β inhibitor treatment prolonged their survival and rescued the leukemic burden. Our results identify a potentially new target for treating DNMT3A mutation-driven myeloid malignancies.