What is a teratoma assay?
In the teratoma assay, putative pluripotent stem cells (PSCs) are implanted into an immune-compromised mouse where they may proliferate and differentiate to form a teratoma. The teratoma may be further processed by immunocytochemistry and gene expression profiling.
What is teratoma formation?
When implanted into immunodeficient mice, human embryonic stem cells (hESCs) give rise to teratoma, tumor-like formations containing tissues belonging to all three germ layers. The ability to form teratoma is a sine qua non characteristic of pluripotent stem cells.
Are teratomas pluripotent?
Pluripotency of a cell line is confirmed by whether the teratoma contains tissues derived from each of the embryonic germ layers: endoderm, mesoderm, and ectoderm. Alternatively, explanted and fixed teratomas can be cryopreserved for immunohistochemistry.
What is meant by pluripotency?
Pluripotency is defined as the capacity of individual cells to initiate all lineages of the mature organism in response to signals from the embryo or cell culture environment. This is the foundation of mammalian development and of ES (embryonic stem) cell biology.
What are teratomas?
(TAYR-uh-TOH-muh) A type of germ cell tumor that may contain several different types of tissue, such as hair, muscle, and bone. Teratomas may be mature or immature, based on how normal the cells look under a microscope. Sometimes teratomas are a mix of mature and immature cells.
What is a feeder layer?
Basically, feeder cells consist in a layer of cells unable to divide, which provides extracellular secretions to help another cell to proliferate. In this context, human stem and pluripotent cells play an important role, but the presence of feeder cells is necessary for these progenitor cells to grow and differentiate.
Can a teratoma have eyes?
“Teratoma” is Greek for “monstrous tumor”; these tumors were so named because they sometimes contain hair, teeth, bone, neurons, and even eyes.
Is a teratoma a baby?
Teratomas are usually benign in newborns, but may still require surgical removal.
Why do teratomas form?
What Causes Teratoma? Teratomas happen when complications arise during your cells’ differentiation process. In particular, they develop in your body’s germ cells, which are undifferentiated. This means they can turn into any type of cell – from egg and sperm to hair cells.
Which type of cell is unspecialized?
Stem cells
Stem cells are self-sustaining by replicating themselves for a much longer period of time. They are unspecialized: Specialized cells have specific capabilities that allow them to perform certain tasks. For example a red blood cell contains hemoglobin that allows it to carry oxygen.
What are the two types of stem cells?
Stem cells are broadly classified as either adult or embryonic. Technically, even stem cells that come from fetal tissue or umbilical cord blood are classified as adult stem cells, and so most researchers prefer the term tissue stem cells for all stem cells other than those from embryos.
Are teratomas rare?
It’s the most common tumor found in newborns and children, but it’s still rare overall. It occurs in about 1 in every 35,000 to 40,000 infants. These teratoma can grow outside or inside the body in the tailbone area.
How is the teratoma assay used in cancer treatment?
A key hazard in the implementation of hESC-based cell therapy is potential tumor formation caused by the presence of pluripotent hESCs within the transplanted cell preparations. A standardized sensitive teratoma assay to detect low numbers of tumor forming cells within a therapeutic cell preparation would be highly valuable.
Which is the correct definition of a teratoma?
The teratoma always means a nonmalignant tumor which comprised of a disorganized cell mixture and small tissues containing cells from all three embryonic germ-layers. With any iPSC lines, it is necessary to confirm pluripotency and characterize the cell lines before the following downstream regulation experiments.
Is the teratoma assay sensitive to hESCs?
It was sensitive, promoting teratoma formation after transplantation of 100 hESCs, though larger numbers of animals and longer follow-up were required. The assay could detect residual teratoma forming cells within differentiated hESC populations however its sensitivity was decreased in the presence of differentiated cells.
Is there a standard protocol for teratoma formation?
Now Creative Biolabs has built a standard protocol for teratoma assay based on subcutaneous co-transplantation of human iPSCs with mitotically inactivated feeder cells and Matrigel into immunodeficient mice. Fig.1 Schematic of teratoma formation.