CD73 Regulates Stemness and Epithelial-Mesenchymal Transition in Ovarian Cancer-Initiating Cells

Abstract

SummaryCancer-initiating cells (CICs) have been implicated in tumor development and aggressiveness. In ovarian carcinoma (OC), CICs drive tumor formation, dissemination, and recurrence, as well as drug resistance, thus accounting for the high death-to-incidence ratio of this neoplasm. However, the molecular mechanisms that underlie such a pathogenic role of ovarian CICs (OCICs) remain elusive. Here, we have capitalized on primary cells either from OC or from its tissues of origin to obtain the transcriptomic profile associated with OCICs. Among the genes differentially expressed in OCICs, we focused on CD73, which encodes the membrane-associated 5′-ectonucleotidase. The genetic inactivation of CD73 in OC cells revealed that this molecule is causally involved in sphere formation and tumor initiation, thus emerging as a driver of OCIC function. Furthermore, functional inhibition of CD73 via either a chemical compound or a neutralizing antibody reduced sphere formation and tumorigenesis, highlighting the druggability of CD73 in the context of OCIC-directed therapies. The biological function of CD73 in OCICs required its enzymatic activity and involved adenosine signaling. Mechanistically, CD73 promotes the expression of stemness and epithelial-mesenchymal transition-associated genes, implying a regulation of OCIC function at the transcriptional level. CD73, therefore, is involved in OCIC biology and may represent a therapeutic target for innovative treatments aimed at OC eradication.

Development of miRNA‐based therapeutic approaches for cancer patients

“…Over the past decade, CSC have been identified in many common cancer types, ranging from leukemia to solid tumors. [25][26][27][28][29][30][31][32][33] The main properties of CSC, including tumor-seeding ability and therapy resistance, have been evaluated in immunodeficient mice. Specifically, CSC were isolated by cell sorting for specific markers and then transplanted into immunodeficient mice, where their tumor-seeding abilities were examined.…”

A cell-of-origin epigenetic tracer reveals clinically distinct subtypes of high grade serous ovarian cancer

“…Primary cells from FI and OSE were derived from non-neoplastic fimbriae and ovaries, respectively, from patients undergoing adnexectomy for nonovarian gynecological pathologies. The isolation and culture of primary cells were performed as described previously 38,39 . Cells were used at passage 3 to 5.…”

Single cell derived organoids capture the self-renewing subpopulations of metastatic ovarian cancer

“…1, see Methods). Cancer Propagating Cells (CPCs), characterized by tumor-maintaining potential, self-renewal and anoikis-resistance, have been isolated from solid tumors and OC mostly by enrichment through tumor-sphere cultures, harnessing their ability to proliferate under non-adherent conditions 17,18 . For HGSOC, however, no method is yet available for the isolation and culture of individual tumor cells.…”

“…In order to investigate the cellular composition of scOCOs, we took advantage of validated cell-type specific gene markers to define transcriptional signatures to interrogate our dataset. To assess whether our 3D system is enriching for cancer initiating cells, we employed markers that have been widely used for their isolation in solid tumors and specifically in HGSOC 18 (supplementary table 2). Moreover, considering that more than 90% of malignant ovarian tumors have an epithelial origin and that epithelial mesenchymal transition (EMT) is both a crucial factor for cancer progression and a prerequisite for metastatization 24,25 , we also investigated the expression of EMT-associated genes along with those defining the epithelial compartment per se 26,27 (supplementary table 2 Finally, we sought to determine whether scOCOs could retain also patient-specific features, despite the overall convergence observed through diffusion map ( fig.…”

“…For HGSOC there are no organoid-based platforms that allow the prospective propagation and molecular characterization of individual tumor cells. Thus, we set out to establish a new method to isolate and grow them in 3D, taking advantage of the ability of HGSOC cancer initiating cells to grow in an anchorage-independent manner 17,18 and harnessing this property for the establishment of clonal cultures in individual wells that could, thus, allow longitudinal tracing of their propagated features. Importantly, given the specific features of the disease recounted above, we reasoned that the method would be particularly relevant if applicable directly to metastatic ascitis, as a highly informative disease stage of relatively easy access for the streamlined translation of this method to the clinical setting.…”