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MicroRNAs in human embryonic and cancer stem cells.

Navarro A, Monzo M - Yonsei Med. J. (2010)

Bottom Line: The miRNA pathway has been shown to be crucial in embryonic development and in embryonic stem (ES) cells, as shown by Dicer knockout analysis.Specific patterns of miRNAs have been reported to be expressed only in ES cells and in early phases of embryonic development.Moreover, many cancers present small populations of cells with stem cell characteristics, called cancer stem cells (CSCs).

View Article: PubMed Central - PubMed

Affiliation: Human Anatomy and Embryology Unit, Molecular Oncology and Embryology Laboratory, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain.

ABSTRACT
MicroRNAs (miRNAs) are small non-coding RNAs that regulate messenger RNAs at the post-transcriptional level. They play an important role in the control of cell physiological functions, and their alterations have been related to cancer, where they can function as oncogenes or tumor suppressor genes. Recently, they have emerged as key regulators of "stemness", collaborating in the maintenance of pluripotency, control of self-renewal, and differentiation of stem cells. The miRNA pathway has been shown to be crucial in embryonic development and in embryonic stem (ES) cells, as shown by Dicer knockout analysis. Specific patterns of miRNAs have been reported to be expressed only in ES cells and in early phases of embryonic development. Moreover, many cancers present small populations of cells with stem cell characteristics, called cancer stem cells (CSCs). CSCs are responsible for relapse and treatment failure in many cancer patients, and the comparative analysis of expression patterns between ES cells and tumors can lead to the identification of a miRNA signature to define CSCs. Most of the key miRNAs identified to date in ES cells have been shown to play a role in tumor diagnosis or prognosis, and may well prove to be essential in cancer therapy in the foreseeable future.

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Related in: MedlinePlus

Timeline showing the main discoveries in stem cell biology and miRNA research. miRNA, microRNA.
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Figure 1: Timeline showing the main discoveries in stem cell biology and miRNA research. miRNA, microRNA.

Mentions: ES cells may participate in normal embryonic development when they are injected into the blastocyst. In contrast, ES cells develop into tumors if injected in ectopic sites in adult mice. Moreover, the role of microenvironment in the growth control of embryonic stem cells has also been examined. When ES cells were injected in pregnant mouse uteri, no tumor formation was observed; in contrast, the ES cells injected into pseudopregnant uteri often developed into tumors, and those injected into non-pregnant uteri always developed into teratocarcinomas. These results showed that the pregnant-uterine microenvironment may participate in the control of ES cell growth.7 Now we know that stem cells are controlled by extrinsic signals from their regulatory niche and also by intrinsic factors like the hyperdynamic plasticity of chromatin proteins.8 In summary, ES cells can readily be shown to differentiate into essentially all cell phenotypes, whereas most isolates of adult stem cells have more limited potential for differentiation. Both retain the capacity to divide indefinitely, and this division must be finely regulated because few divisions can alter tissue homeostasis and many divisions can drive to cancer initiation. Many cancers present small populations of cells with stem cell characteristics, called cancer stem cells (CSCs). Recently, novel elements, microRNAs (miRNAs), have emerged as crucial regulators for proper stem cell maintenance and function (Fig. 1).


MicroRNAs in human embryonic and cancer stem cells.

Navarro A, Monzo M - Yonsei Med. J. (2010)

Timeline showing the main discoveries in stem cell biology and miRNA research. miRNA, microRNA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2908867&req=5

Figure 1: Timeline showing the main discoveries in stem cell biology and miRNA research. miRNA, microRNA.
Mentions: ES cells may participate in normal embryonic development when they are injected into the blastocyst. In contrast, ES cells develop into tumors if injected in ectopic sites in adult mice. Moreover, the role of microenvironment in the growth control of embryonic stem cells has also been examined. When ES cells were injected in pregnant mouse uteri, no tumor formation was observed; in contrast, the ES cells injected into pseudopregnant uteri often developed into tumors, and those injected into non-pregnant uteri always developed into teratocarcinomas. These results showed that the pregnant-uterine microenvironment may participate in the control of ES cell growth.7 Now we know that stem cells are controlled by extrinsic signals from their regulatory niche and also by intrinsic factors like the hyperdynamic plasticity of chromatin proteins.8 In summary, ES cells can readily be shown to differentiate into essentially all cell phenotypes, whereas most isolates of adult stem cells have more limited potential for differentiation. Both retain the capacity to divide indefinitely, and this division must be finely regulated because few divisions can alter tissue homeostasis and many divisions can drive to cancer initiation. Many cancers present small populations of cells with stem cell characteristics, called cancer stem cells (CSCs). Recently, novel elements, microRNAs (miRNAs), have emerged as crucial regulators for proper stem cell maintenance and function (Fig. 1).

Bottom Line: The miRNA pathway has been shown to be crucial in embryonic development and in embryonic stem (ES) cells, as shown by Dicer knockout analysis.Specific patterns of miRNAs have been reported to be expressed only in ES cells and in early phases of embryonic development.Moreover, many cancers present small populations of cells with stem cell characteristics, called cancer stem cells (CSCs).

View Article: PubMed Central - PubMed

Affiliation: Human Anatomy and Embryology Unit, Molecular Oncology and Embryology Laboratory, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain.

ABSTRACT
MicroRNAs (miRNAs) are small non-coding RNAs that regulate messenger RNAs at the post-transcriptional level. They play an important role in the control of cell physiological functions, and their alterations have been related to cancer, where they can function as oncogenes or tumor suppressor genes. Recently, they have emerged as key regulators of "stemness", collaborating in the maintenance of pluripotency, control of self-renewal, and differentiation of stem cells. The miRNA pathway has been shown to be crucial in embryonic development and in embryonic stem (ES) cells, as shown by Dicer knockout analysis. Specific patterns of miRNAs have been reported to be expressed only in ES cells and in early phases of embryonic development. Moreover, many cancers present small populations of cells with stem cell characteristics, called cancer stem cells (CSCs). CSCs are responsible for relapse and treatment failure in many cancer patients, and the comparative analysis of expression patterns between ES cells and tumors can lead to the identification of a miRNA signature to define CSCs. Most of the key miRNAs identified to date in ES cells have been shown to play a role in tumor diagnosis or prognosis, and may well prove to be essential in cancer therapy in the foreseeable future.

Show MeSH
Related in: MedlinePlus