Identification and characterization of the human leiomyoma side population as putative tumor-initiating cells.

Objective To isolate and characterize human leiomyoma stem cells by the side population (SP) method. Design Prospective experimental human and animal study. Setting University research laboratory-affiliated infertility clinic. Patient(s) Women undergoing laparoscopic myomectomy. Animal(s) Female non-obese diabetic severe combined immune deficiency (NOD-SCID) mutation mice. Intervention(s) Obtainment of human leiomyoma SP cells as candidate tumor-initiating cells and establishment of two leiomyoma SP lines. Main Outcome Measure(s) Flow cytometry, semiquantitative polymerase chain reaction, clonogenicity assays, cDNA microarrays hybridization, cell culture, karyotype, molecular analysis, immu…

Early life exposure to estrogen-mimics increase the occurrence of uterine fibroids via expansion of myometrial stem cell population

COMPARISON OF OPERATIVE AND PERI-OPERATIVE RESULTS FOR ROBOTIC AND LAPAROSCOPIC MYOMECTOMIES. C. E. Miller, K. Sasaki, C. Steller, S. Sulo, A. Cholkeri-Singh. The Advanced IVF Institute, Naperville, IL; Advanced Gynecologic Surgery Institute, Naperville, IL; Advocate Lutheran General Hospital, Park Ridge, IL; Center for Advanced Care, Russell Institute of Research and Innovation, Park Ridge, IL; The Advanced Gynecologic Surgery Institute, Naperville, IL.

Role of Stro1+/CD44+ stem cells in myometrial physiology and uterine remodeling during pregnancy†

Regulation of myometrial functions during pregnancy has been considered the result of the integration of endocrine and mechanical signals. Nevertheless, uterine regeneration is poorly understood, and the cellular source within the gravid uterus is largely unexplored.In this study, we isolated and quantified the myometrial stem cells (MSC) population from pregnant female Eker rat uteri, by using Stro1/CD44 surface markers. We demonstrated that prior parity significantly increased the percentage of Stro1+/CD44+ MSC because of injured tissue response. Interestingly, we established that Stro1+/CD44+ MSC respond efficiently to physiological cues when they were treated in vitro under different do…

Molecular and Cellular Insights into the Development of Uterine Fibroids

Uterine leiomyomas represent the most common benign gynecologic tumor. These hormone-dependent smooth-muscle formations occur with an estimated prevalence of ~70% among women of reproductive age and cause symptoms including pain, abnormal uterine bleeding, infertility, and recurrent abortion. Despite the prevalence and public health impact of uterine leiomyomas, available treatments remain limited. Among the potential causes of leiomyomas, early hormonal exposure during periods of development may result in developmental reprogramming via epigenetic changes that persist in adulthood, leading to disease onset or progression. Recent developments in unbiased high-throughput sequencing technolog…

Molecular differential diagnosis of uterine leiomyomas and leiomyosarcomas.

Abstract Uterine leiomyomas (LM) and leiomyosarcomas (LMS) are considered biologically unrelated tumors due to their cytogenetic and molecular disparity. Yet, these tumors share morphological and molecular characteristics that cannot be differentiated through current clinical diagnostic tests, and thus cannot be definitively classified as benign or malignant until surgery. Newer approaches are needed for the identification of these tumors, as has been done for other tissues. The application of next generation sequencing enables the detection of new mutations that, when coupled to machine learning bioinformatic tools, advances our understanding of chromosomal instability. These approaches in…

Synergistic effect of estrogen and progesterone on myometrial stem cell expansion in vivo

Current understanding of somatic stem cells in leiomyoma formation.

Objective To provide a detailed summary of current scientific knowledge of somatic stem cells (SSCs) in murine and human myometrium and their putative implication in leiomyoma formation, as well as to establish new therapeutic options. Design Pubmed and Scholar One manuscripts were used to identify the most relevant studies on SSCs and their implications in human myometrium and leiomyomas. Setting University research laboratory–affiliated infertility clinic. Patient(s) Not applicable. Intervention(s) Not applicable. Main Outcome Measure(s) Not applicable. Result(s) Despite numerous publications on SSCs, it was not until 2007 that scientific evidence based on the use of 5-bromo-2′-deoxyuridi…

SINGLE CELL TRANSCRIPTOMES FROM UTERINE FIBROIDS AND FIBROID-FREE MYOMETRIUM ELUCIDATE MYOMETRIAL TUMORIGENESIS

Single cell RNAseq analyses of uterine fibroids and fibroid-free myometria reveal previously unidentified cell type and state

Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) as a putative human endometrial stem cell marker†

The endometrium is recognized for its remarkable regenerative and remodeling capacity. Every month this hormonally regu- lated organ undergoes cycles of growth (from 0.5-2 to 7 mm), regression and shedding of two-third of the tissue, leading to its monthly renewal that occurs � 400 times in a woman's reproductive lifetime. Several groups have suggested the existence of a human endometrial somatic stem cell (SSC) population located around the spiral arterioles of the basalis. Different groups have isolated, identified and charac- terized putative endometrial SSC populations in human endometrium based on the general features of undifferentiated cells, such as slow cycling detected using the 5…

Somatic stem cells in the human endometrium.

The existence of human endometrial somatic stem cells was proposed in the mid-20th century for the first time. This hypothesis became stronger and was revised by two authors between 1978 and 1989. Nevertheless, it was not until 2004 that scientific evidence was first published. As we describe here, the great regenerative capability of the human endometrium has been finally questioned in the last 8 years, and this period can be considered the most productive in endometrial stem cell biology given the new scientific information recapitulated to date. We provide a detailed summary based on the actual scientific knowledge obtained about (1) the existence of somatic stem cells in murine (detecte…

The differential diagnoses of uterine leiomyomas and leiomyosarcomas using DNA and RNA sequencing.

BACKGROUND: Although uterine leiomyomas and leiomyosarcomas are considered biologically unrelated tumors, they share morphologic and histologic characteristics that complicate their differential diagnosis. The long-term therapeutic option for leiomyoma is laparoscopic myomectomy with morcellation, particularly for patients who wish to preserve their fertility. However, because of the potential dissemination of undiagnosed or hidden leiomyosarcoma from morcellation, there is a need to develop a preoperative assessment of malignancy risk. OBJECTIVE: Through an integrated comparative genomic and transcriptomic analysis, we aim to identify differential genetic targets in leiomyomas vs leiomyosa…

Reconstruction of Endometrium from Human Endometrial Side Population Cell Lines

Endometrial regeneration is mediated, at least in part, by the existence of a specialized somatic stem cell (SSC) population recently identified by several groups using the side population (SP) technique. We previously demonstrated that endometrial SP displays genotypic, phenotypic and the functional capability to develop human endometrium after subcutaneous injection in NOD-SCID mice. We have now established seven human endometrial SP (hESP) cell lines (ICE 1-7): four from the epithelial and three from the stromal fraction, respectively. SP cell lines were generated under hypoxic conditions based on their cloning efficiency ability, cultured for 12-15 passages (20 weeks) and cryopreserved.…

Human Endometrial Side Population Cells Exhibit Genotypic, Phenotypic and Functional Features of Somatic Stem Cells

During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis for women's cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC) population. Here we explore the hypothesis that human endometrial side population (SP) cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and char…

Overexpression of the truncated form of high mobility group a proteins (HMGA2) in human myometrial cells induces leiomyoma-like tissue formation

The pathogenesis of uterine leiomyomas, the most common benign tumor in women, is still unknown. This lack of basic knowledge limits the development of novel non-invasive therapies. Our group has previously demonstrated that leiomyoma side population (SP) cells are present in tumor lesions and act like putative tumor-initiating stemcells in human leiomyoma. Moreover, accumulated evidence demonstrates that these benign tumors of mesenchymal origin are characterized by rearrangements of the High Mobility Group A proteins (HMGA). In this work, we tested the hypothesis that leiomyoma development may be due to overexpression of HMGA2 (encoding high mobility group AT-hook2) in myometrial stem cel…

Stro-1/CD44 as putative human myometrial and fibroid stem cell markers

Objective To identify and characterize myometrial/fibroid stem cells by specific stem cell markers in human myometrium, and to better understand the stem cell contribution in the development of uterine fibroids. Design Prospective, experimental human and animal study. Setting University research laboratory. Patient(s)/Animal(s) Women undergoing hysterectomy for treatment of symptomatic uterine fibroids and female NOD/SCID/IL-2Rγ null mice. Intervention(s) Identification and isolation of stem cells from human fibroids and adjacent myometrium tissues using Stro-1/CD44–specific surface markers. Main Outcome Measure(s) Flow cytometry, semiquantitative polymerase chain reaction, clonogenicity as…

Bone Marrow-Derived Cells from Male Donors Do Not Contribute to the Endometrial Side Population of the Recipient

Accumulated evidence demonstrates the existence of bone marrow-derived cells origin in the endometria of women undergoing bone marrow transplantation (BMT). In these reports, cells of a bone marrow (BM) origin are able to differentiate into endometrial cells, although their contribution to endometrial regeneration is not yet clear. We have previously demonstrated the functional relevance of side population (SP) cells as the endogenous source of somatic stem cells (SSC) in the human endometrium. The present work aims to understand the presence and contribution of bone marrow-derived cells to the endometrium and the endometrial SP population of women who received BMT from male donors. Five fe…