In human osteosarcoma 3AB-OS cancer stem cells let-7d seems to have the dual function of oncogene/tumor-suppressor miRNA

Introduction: Osteosarcoma (OS), an aggressive tumor a!ecting adolescents, shows therapy resistance and recurrence which can depend on cancer stem cells (CSCs), the source for tissue renewal and hold malignant potential; thus, OS treatment requires their eradication. Here, using 3AB-OS CSCs previously obtained from the OS-MG63 cells, we focused on the role of let-7d in managing stemness properties of 3AB-OS CSCs. Methods: 3AB-OS CSCs were stably transfected with pCDomH-plasmid, containing mir-let7-d, or empty vector as a control. Cell proliferation and viability were evaluated by EdU and Trypan blue assays, respectively. Sarcosphere and colony assays and wound healing and transwell invasion…

In Human Retinoblastoma Y-79 Cells 3-aminobenzamide induces Differentiation

Let-7d miRNA Shows Both Antioncogenic and Oncogenic Functions in Osteosarcoma-Derived 3AB-OS Cancer Stem Cells

Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 an…

Sensitivity of human retinoblastoma Y79 cells to Paclitaxel was mediated by aberrant E2F1 expression and p53 accumulation

Identification and Isolation of Cancer Stem Cell

Identification and expansion of human osteosarcoma-cancer-stem cells by long-term 3-aminobenzamide treatment

A novel cancer stem-like cell line (3AB-OS), expressing a number of pluripotent stem cell markers, was irreversibly selected from human osteosarcoma MG-63 cells by long-term treatment (100 days) with 3-aminobenzamide (3AB). 3AB-OS cells are a heterogeneous and stable cell population composed by three types of fibroblastoid cells, spindle-shaped, polygonal-shaped, and rounded-shaped. With respect to MG-63 cells, 3AB-OS cells are extremely smaller, possess a much greater capacity to form spheres, a stronger self-renewal ability and much higher levels of cell cycle markers which account for G1-S/G2-M phases progression. Differently from MG-63 cells, 3AB-OS cells can be reseeded unlimitedly wit…

Induction of apoptosis by 3-AB in Y79 human retinoblastoma cells, associated with upregulation of p53 and Apo-1/Fas.

3AB-OS, a human osteosarcoma stem-like cell line, potential model for studying cancer

Janus-Faced role of microRNA let-7d in osteosarcoma 3AB-OS cancer stem cells

Osteosarcoma (OS) is the most common malignancy of bone in children and adolescent. It is a highly invasive and metastatic bone-malignancy because of which, despite therapeutic advances, 30%-50% of patients still die of pulmonary metastasis. As a consequence, there is an urgent need to identify new therapeutic strategies to improve the clinical outcome of the patients. Advances in OS treatment are inconceivable without better understanding of molecular mechanism of osteosarmagenesis and, especially, metastatic processes. Growing evidence suggests that cancer stem cells (CSCs), which have self-renewing and malignant potential, are at the root of tumor growth and relapse. Thus, a challenge fo…

Mutant p53 gain of function in human osteosarcoma 3AB-OS cancer stem cells

Human osteosarcoma 3AB-OS cancer stem cells is a model to study microRNA-29b-1 involvement in self-renewal and fate decisions of stem cells

MiR-29b-1 expression impaired Cancer Stem-Like properties of human osteosarcoma 3AB-OS cells in vitro.

Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. Although microRNAs are frequently dysregulated in human cancers, if they influence OS malignancy and whether or not targeting CSC-associated microRNAs inhibit OS progression remain unclear. Recently (1), we described a predictive network for two downregulated miRNA family (let-7/98 and miR-29a,b,c) and their upregulated anticorrelated mRNAs. Here, we investigated in vitro the role of miR-29b-1 in regulating cell proliferation, clonogenic growth and che…

EFFECTS OF 3-AMINOBENZAMIDE ON HUMAN RETINOBLASTOMA Y79 CELLS.

Cellule staminali di osteosarcoma umano 3AB-OS: un modello per analizzare le proprietà oncogeniche di p53 mutata.

Alterazioni del gene TP53 si riscontrano in circa il 50% dei tumori umani (1). Negli ultimi anni è stato dimostrato che la proteina mutata p53 (mp53) acquisisce nuove proprietà oncogeniche, definite “gain of function” (GOF), che contribuiscono alla progressione tumorale (2). In questo studio è stato analizzato lo stato del gene TP53, della proteina da esso espressa e il loro ruolo nella promozione della proliferazione, invasività, resistenza all’apoptosi e staminalità delle cellule 3AB-OS, una linea tumorale staminale precedentemente isolata dalle cellule di osteosarcoma umano MG63 (3). Analisi comparative di RT-PCR, Methylation-Specific-PCR (MSP), Fluorescent-in situ-hybridization (FISH) e…

PACLITAXEL INDUCES APOPTOSIS IN HUMAN RETINOBLASTOMA Y79 CELLS

Microscopy Fluorescence and Apoptosis Studies

PROLONGED TREATMENT OF HUMAN OSTEOSARCOMA MG63 CELLS WITH 3AB INDUCES THE PRODUCTION OF TUMOR INITIATING CELLS.

Retinoblastoma: History of His Identification, Characterization and Treatment

The first description of a tumor resembling retinoblastoma (RB) was provided on 1597 by Pieter Pauw, who described a malignancy invading the orbit, the temporal region, and the cranium, filled with a "substance similar to brain tissue mixed with thick blood and like crushed stone". Since then, a number of retinal tumors were described and named until the 1922 when Verhoeff called these tumors RB, a term that the American Ophthalmological Society adopted in 1926. In 1971 Knudson focused on RB, and proposed his ‘two-hit’ theory of the molecular etiology of RB. In 1986, the RB1 gene was identified and the ‘two-hit’ theory of Knudson was validated. Successively, new studies in developing retina…

MicroRNA-29b-1 is involved in self-renewal and fate decisions of human osteosarcoma 3AB-OS cancer stem cells

Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. Moreover, identification of CSC-related MicroRNAs (miRNAs) would provide information for a better understanding of CSCs. miR-29 family is a class of miRNAs aberrantly expressed in multiple cancers. They are frequently down-regulated in osteosarcoma (OS), the most common form of childhood cancer with a potent metastasizing potential. 3AB-OS CSC, a human pluripotent CSC line by us produced from the human osteosarcoma MG63 cells (1) is a useful model to study CSC origin and roles (2). Previously, we have shown that in 3AB-OS CSCs miR-29b is potently down-re…

Karyotypic Complexity and Chromosomal Aberrations In Human Embryonic Cancer Stem Cells 3AB-OS.

3AB-OS, a new human pluripotent cancer stem cell: properties and expectations for practical applications.

PACLITAXEL POTENTLY INDUCES APOPTOSIS IN HUMAN RETINOBLASTOMA Y79 CELLS

TREATMENT OF HUMAN OSTEOSARCOMA CELLS WITH 3AB INDUCES THE APPEARANCE OF CD133+ CELL POPULATION CONTAINING A POTENTIALLY STEM-LIKE PHENOTYPE

Okadaic acid-Parthenolide combination at subtoxic doses induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells by upregulating PTEN.

Retinoblastoma is the most common intraocular malignancy afflicting children. The incidence is higher in developing countries, where treatment is limited and long-term survival rates are low. Vincristine, etoposide, and carboplatin -the agents commonly used in the treatment of retinoblastoma- determine side effects causing significant morbidity to pediatric patients and significantly limiting dosing. Thus, identifying new drugs and molecular targets to facilitate the development of novel therapeutics, and finding natural drug combinations to kill cancer cells by synergistically acting at subtoxic doses, may be a good goal. Here, we investigated the effects of two natural compounds, okadaic …