Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells.
The role of miRNAs in acquired endocrine-resistant breast cancer is not fully understood. One hallmark of tumor progression is epithelial-to-mesenchymal transition (EMT), characterized by a loss of cell adhesion resulting from reduced E-cadherin and increased cell mobility. miR-200 family members re...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2013-01-01
|
| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3633860?pdf=render |
| _version_ | 1828404542100733952 |
|---|---|
| author | Tissa T Manavalan Yun Teng Lacey M Litchfield Penn Muluhngwi Numan Al-Rayyan Carolyn M Klinge |
| author_facet | Tissa T Manavalan Yun Teng Lacey M Litchfield Penn Muluhngwi Numan Al-Rayyan Carolyn M Klinge |
| author_sort | Tissa T Manavalan |
| collection | DOAJ |
| description | The role of miRNAs in acquired endocrine-resistant breast cancer is not fully understood. One hallmark of tumor progression is epithelial-to-mesenchymal transition (EMT), characterized by a loss of cell adhesion resulting from reduced E-cadherin and increased cell mobility. miR-200 family members regulate EMT by suppressing expression of transcriptional repressors ZEB1/2. Previously we reported that the expression of miR-200a, miR-200b, and miR-200c was lower in LY2 endocrine-resistant, mesenchymal breast cancer cells compared to parental, endocrine sensitive, epithelial MCF-7 breast cancer cells. Here we investigated the regulation of miR-200 family members and their role in endocrine-sensitivity in breast cancer cells.miR-200 family expression was progressively reduced in a breast cancer cell line model of advancing endocrine/tamoxifen (TAM) resistance. Concomitant with miR-200 decrease, there was an increase in ZEB1 mRNA expression. Overexpression of miR-200b or miR-200c in LY2 cells altered cell morphology to a more epithelial appearance and inhibited cell migration. Further, miR-200b and miR-200c overexpression sensitized LY2 cells to growth inhibition by estrogen receptor (ER) antagonists TAM and fulvestrant. Knockdown of ZEB1 in LY2 cells recapitulated the effect of miR-200b and miR-200c overexpression resulting in inhibition of LY2 cell proliferation by TAM and fulvestrant, but not the aromatase inhibitor exemestane. Demethylating agent 5-aza-2'-deoxycytidine (5-aza-dC) in combination with histone deacetylase inhibitor trichostatin A (TSA) increased miR-200b and miR-200c in LY2 cells. Concomitant with the increase in miR-200b and miR-200c, ZEB1 expression was decreased and cells appeared more epithelial in morphology and were sensitized to TAM and fulvestrant inhibition. Likewise, knockdown of ZEB1 increased antiestrogen sensitivity of LY2 cells resulting in inhibition of cell proliferation.Our data indicate that reduced miRNA-200b and miR-200c expression contributes to endocrine resistance in breast cancer cells and that the reduced expression of these miR-200 family members in endocrine-resistant cells can be reversed by 5-aza-dC+TSA. |
| first_indexed | 2024-12-10T10:38:23Z |
| format | Article |
| id | doaj.art-4ced475495ef4cae8c1783ccb9b8ff6a |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-10T10:38:23Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-4ced475495ef4cae8c1783ccb9b8ff6a2022-12-22T01:52:22ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0184e6233410.1371/journal.pone.0062334Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells.Tissa T ManavalanYun TengLacey M LitchfieldPenn MuluhngwiNuman Al-RayyanCarolyn M KlingeThe role of miRNAs in acquired endocrine-resistant breast cancer is not fully understood. One hallmark of tumor progression is epithelial-to-mesenchymal transition (EMT), characterized by a loss of cell adhesion resulting from reduced E-cadherin and increased cell mobility. miR-200 family members regulate EMT by suppressing expression of transcriptional repressors ZEB1/2. Previously we reported that the expression of miR-200a, miR-200b, and miR-200c was lower in LY2 endocrine-resistant, mesenchymal breast cancer cells compared to parental, endocrine sensitive, epithelial MCF-7 breast cancer cells. Here we investigated the regulation of miR-200 family members and their role in endocrine-sensitivity in breast cancer cells.miR-200 family expression was progressively reduced in a breast cancer cell line model of advancing endocrine/tamoxifen (TAM) resistance. Concomitant with miR-200 decrease, there was an increase in ZEB1 mRNA expression. Overexpression of miR-200b or miR-200c in LY2 cells altered cell morphology to a more epithelial appearance and inhibited cell migration. Further, miR-200b and miR-200c overexpression sensitized LY2 cells to growth inhibition by estrogen receptor (ER) antagonists TAM and fulvestrant. Knockdown of ZEB1 in LY2 cells recapitulated the effect of miR-200b and miR-200c overexpression resulting in inhibition of LY2 cell proliferation by TAM and fulvestrant, but not the aromatase inhibitor exemestane. Demethylating agent 5-aza-2'-deoxycytidine (5-aza-dC) in combination with histone deacetylase inhibitor trichostatin A (TSA) increased miR-200b and miR-200c in LY2 cells. Concomitant with the increase in miR-200b and miR-200c, ZEB1 expression was decreased and cells appeared more epithelial in morphology and were sensitized to TAM and fulvestrant inhibition. Likewise, knockdown of ZEB1 increased antiestrogen sensitivity of LY2 cells resulting in inhibition of cell proliferation.Our data indicate that reduced miRNA-200b and miR-200c expression contributes to endocrine resistance in breast cancer cells and that the reduced expression of these miR-200 family members in endocrine-resistant cells can be reversed by 5-aza-dC+TSA.http://europepmc.org/articles/PMC3633860?pdf=render |
| spellingShingle | Tissa T Manavalan Yun Teng Lacey M Litchfield Penn Muluhngwi Numan Al-Rayyan Carolyn M Klinge Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells. PLoS ONE |
| title | Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells. |
| title_full | Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells. |
| title_fullStr | Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells. |
| title_full_unstemmed | Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells. |
| title_short | Reduced expression of miR-200 family members contributes to antiestrogen resistance in LY2 human breast cancer cells. |
| title_sort | reduced expression of mir 200 family members contributes to antiestrogen resistance in ly2 human breast cancer cells |
| url | http://europepmc.org/articles/PMC3633860?pdf=render |
| work_keys_str_mv | AT tissatmanavalan reducedexpressionofmir200familymemberscontributestoantiestrogenresistanceinly2humanbreastcancercells AT yunteng reducedexpressionofmir200familymemberscontributestoantiestrogenresistanceinly2humanbreastcancercells AT laceymlitchfield reducedexpressionofmir200familymemberscontributestoantiestrogenresistanceinly2humanbreastcancercells AT pennmuluhngwi reducedexpressionofmir200familymemberscontributestoantiestrogenresistanceinly2humanbreastcancercells AT numanalrayyan reducedexpressionofmir200familymemberscontributestoantiestrogenresistanceinly2humanbreastcancercells AT carolynmklinge reducedexpressionofmir200familymemberscontributestoantiestrogenresistanceinly2humanbreastcancercells |