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miR-21 and miR-145 cooperation in regulation of colon cancer stem cells

BACKGROUND: Acquired drug resistance is one of the major reasons for failing cancer therapies. Although the reasons are not fully understood, they may be related to the presence of cancer stem cells (CSCs). We have reported that chemo-resistant (CR) colon cancer cells, highly enriched in CSCs, exhib...

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Autores principales: Yu, Yingjie, Nangia-Makker, Pratima, Farhana, Lulu, G. Rajendra, Sindhu, Levi, Edi, Majumdar, Adhip PN
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4415383/
https://www.ncbi.nlm.nih.gov/pubmed/25928322
http://dx.doi.org/10.1186/s12943-015-0372-7
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author Yu, Yingjie
Nangia-Makker, Pratima
Farhana, Lulu
G. Rajendra, Sindhu
Levi, Edi
Majumdar, Adhip PN
author_facet Yu, Yingjie
Nangia-Makker, Pratima
Farhana, Lulu
G. Rajendra, Sindhu
Levi, Edi
Majumdar, Adhip PN
author_sort Yu, Yingjie
collection PubMed
description BACKGROUND: Acquired drug resistance is one of the major reasons for failing cancer therapies. Although the reasons are not fully understood, they may be related to the presence of cancer stem cells (CSCs). We have reported that chemo-resistant (CR) colon cancer cells, highly enriched in CSCs, exhibit a marked up-regulation of miR-21 and that down-regulation of this miR renders the CR cells more susceptible to therapeutic regimens. However, the underlying molecular mechanism is poorly understood. The aim of this investigation is to unravel this mechanism. METHODS: The levels of miR-145 and miR-21 were manipulated by transfection of mature, antago-miRs or pCMV/miR-145 expression plasmid. Quantitative RT-PCR or/and Western blots were performed to examine the expression of CD44, β-catenin, Sox-2, PDCD4, CK-20 and k-Ras. Colonosphere formation and SCID mice xenograft studies were performed to evaluate the tumorigenic properties of CSC-enriched colon CR cells. RESULTS: We investigated the role that microRNAs (miRs), specifically miR-21 and miR-145 play in regulating colon CSCs. We found the expression of miR-21 to be greatly increased and miR-145 decreased in CR colon cancer cells that are highly enriched in CSC, indicating a role for these miRNAs in regulating CSCs. In support of this, we found that whereas forced expression of miR-145 in colon cancer cells greatly inhibits CSCs and tumor growth, up-regulation of miR-21 causes an opposite phenomenon. In addition, administration of mature miR-145 or antagomir-21 (anti-sense miR-21) greatly suppresses the growth of colon cancer cell xenografts in SCID mice. This was associated with decreased expression of CD44, β-catenin, Sox-2 and induction of CK-20 indicating that administration of miR-145 or antagomir-21 decreases CSC proliferation and induces differentiation. In vitro studies further demonstrate that miR-21 negatively regulates miR-145 and vice versa. k-Ras appears to play critical role in regulation of this process, as evidenced by the fact that the absence of k-Ras in CR colon cancer cells increases miR-145 expression, suppresses miR-21, and interrupts the negative cooperation between miR-21 and miR-145. CONCLUSIONS: Our current observations suggest that miR-21, miR-145, and their networks play critical roles in regulating CSCs growth and/or differentiation in the colon cancer and progression of chemo-resistance.
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spelling pubmed-44153832015-05-01 miR-21 and miR-145 cooperation in regulation of colon cancer stem cells Yu, Yingjie Nangia-Makker, Pratima Farhana, Lulu G. Rajendra, Sindhu Levi, Edi Majumdar, Adhip PN Mol Cancer Research BACKGROUND: Acquired drug resistance is one of the major reasons for failing cancer therapies. Although the reasons are not fully understood, they may be related to the presence of cancer stem cells (CSCs). We have reported that chemo-resistant (CR) colon cancer cells, highly enriched in CSCs, exhibit a marked up-regulation of miR-21 and that down-regulation of this miR renders the CR cells more susceptible to therapeutic regimens. However, the underlying molecular mechanism is poorly understood. The aim of this investigation is to unravel this mechanism. METHODS: The levels of miR-145 and miR-21 were manipulated by transfection of mature, antago-miRs or pCMV/miR-145 expression plasmid. Quantitative RT-PCR or/and Western blots were performed to examine the expression of CD44, β-catenin, Sox-2, PDCD4, CK-20 and k-Ras. Colonosphere formation and SCID mice xenograft studies were performed to evaluate the tumorigenic properties of CSC-enriched colon CR cells. RESULTS: We investigated the role that microRNAs (miRs), specifically miR-21 and miR-145 play in regulating colon CSCs. We found the expression of miR-21 to be greatly increased and miR-145 decreased in CR colon cancer cells that are highly enriched in CSC, indicating a role for these miRNAs in regulating CSCs. In support of this, we found that whereas forced expression of miR-145 in colon cancer cells greatly inhibits CSCs and tumor growth, up-regulation of miR-21 causes an opposite phenomenon. In addition, administration of mature miR-145 or antagomir-21 (anti-sense miR-21) greatly suppresses the growth of colon cancer cell xenografts in SCID mice. This was associated with decreased expression of CD44, β-catenin, Sox-2 and induction of CK-20 indicating that administration of miR-145 or antagomir-21 decreases CSC proliferation and induces differentiation. In vitro studies further demonstrate that miR-21 negatively regulates miR-145 and vice versa. k-Ras appears to play critical role in regulation of this process, as evidenced by the fact that the absence of k-Ras in CR colon cancer cells increases miR-145 expression, suppresses miR-21, and interrupts the negative cooperation between miR-21 and miR-145. CONCLUSIONS: Our current observations suggest that miR-21, miR-145, and their networks play critical roles in regulating CSCs growth and/or differentiation in the colon cancer and progression of chemo-resistance. BioMed Central 2015-05-01 /pmc/articles/PMC4415383/ /pubmed/25928322 http://dx.doi.org/10.1186/s12943-015-0372-7 Text en © Yu et al.; licensee BioMed Central. 2015 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Yu, Yingjie
Nangia-Makker, Pratima
Farhana, Lulu
G. Rajendra, Sindhu
Levi, Edi
Majumdar, Adhip PN
miR-21 and miR-145 cooperation in regulation of colon cancer stem cells
title miR-21 and miR-145 cooperation in regulation of colon cancer stem cells
title_full miR-21 and miR-145 cooperation in regulation of colon cancer stem cells
title_fullStr miR-21 and miR-145 cooperation in regulation of colon cancer stem cells
title_full_unstemmed miR-21 and miR-145 cooperation in regulation of colon cancer stem cells
title_short miR-21 and miR-145 cooperation in regulation of colon cancer stem cells
title_sort mir-21 and mir-145 cooperation in regulation of colon cancer stem cells
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4415383/
https://www.ncbi.nlm.nih.gov/pubmed/25928322
http://dx.doi.org/10.1186/s12943-015-0372-7
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