Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells.
Obesity is a well-known risk factor for breast cancer development in postmenopausal women. High insulin and leptin levels seem to have a role modulating the growth of these tumours. Sam68 is an RNA-binding protein with signalling functions that has been found to be overexpressed in breast cancer. Mo...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2016-01-01
|
| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4944952?pdf=render |
| _version_ | 1828332631082663936 |
|---|---|
| author | Antonio Pérez-Pérez Flora Sánchez-Jiménez Teresa Vilariño-García Luis de la Cruz Juan A Virizuela Víctor Sánchez-Margalet |
| author_facet | Antonio Pérez-Pérez Flora Sánchez-Jiménez Teresa Vilariño-García Luis de la Cruz Juan A Virizuela Víctor Sánchez-Margalet |
| author_sort | Antonio Pérez-Pérez |
| collection | DOAJ |
| description | Obesity is a well-known risk factor for breast cancer development in postmenopausal women. High insulin and leptin levels seem to have a role modulating the growth of these tumours. Sam68 is an RNA-binding protein with signalling functions that has been found to be overexpressed in breast cancer. Moreover, Sam68 may be recruited to insulin and leptin signalling pathways, mediating its effects on survival, growth and proliferation in different cellular types. We aimed to study the expression of Sam68 and its phosphorylation level upon insulin and leptin stimulation, and the role of Sam68 in the proliferative effect and signalling pathways that are activated by insulin or leptin in human breast adenocarcinoma cells. In the human breast adenocarcinoma cell lines MCF7, MDA-MB-231 and BT-474, Sam68 protein quantity and gene expression were increased upon leptin or insulin stimulation, as it was checked by qPCR and immunoblot. Moreover, both insulin and leptin stimulation promoted an increase in Sam68 tyrosine phosphorylation and negatively regulated its RNA binding capacity. siRNA was used to downregulate Sam68 expression, which resulted in lower proliferative effects of both insulin and leptin, as well as a lower activation of MAPK and PI3K pathways promoted by both hormones. These effects may be partly explained by the decrease in IRS-1 expression by down-regulation of Sam68. These results suggest the participation of Sam68 in both leptin and insulin receptor signaling in human breast cancer cells, mediating the trophic effects of these hormones in proliferation and cellular growth. |
| first_indexed | 2024-04-13T21:07:50Z |
| format | Article |
| id | doaj.art-c1b39d5f0e224d56919032afc04af76c |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-13T21:07:50Z |
| publishDate | 2016-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-c1b39d5f0e224d56919032afc04af76c2022-12-22T02:29:54ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-01117e015821810.1371/journal.pone.0158218Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells.Antonio Pérez-PérezFlora Sánchez-JiménezTeresa Vilariño-GarcíaLuis de la CruzJuan A VirizuelaVíctor Sánchez-MargaletObesity is a well-known risk factor for breast cancer development in postmenopausal women. High insulin and leptin levels seem to have a role modulating the growth of these tumours. Sam68 is an RNA-binding protein with signalling functions that has been found to be overexpressed in breast cancer. Moreover, Sam68 may be recruited to insulin and leptin signalling pathways, mediating its effects on survival, growth and proliferation in different cellular types. We aimed to study the expression of Sam68 and its phosphorylation level upon insulin and leptin stimulation, and the role of Sam68 in the proliferative effect and signalling pathways that are activated by insulin or leptin in human breast adenocarcinoma cells. In the human breast adenocarcinoma cell lines MCF7, MDA-MB-231 and BT-474, Sam68 protein quantity and gene expression were increased upon leptin or insulin stimulation, as it was checked by qPCR and immunoblot. Moreover, both insulin and leptin stimulation promoted an increase in Sam68 tyrosine phosphorylation and negatively regulated its RNA binding capacity. siRNA was used to downregulate Sam68 expression, which resulted in lower proliferative effects of both insulin and leptin, as well as a lower activation of MAPK and PI3K pathways promoted by both hormones. These effects may be partly explained by the decrease in IRS-1 expression by down-regulation of Sam68. These results suggest the participation of Sam68 in both leptin and insulin receptor signaling in human breast cancer cells, mediating the trophic effects of these hormones in proliferation and cellular growth.http://europepmc.org/articles/PMC4944952?pdf=render |
| spellingShingle | Antonio Pérez-Pérez Flora Sánchez-Jiménez Teresa Vilariño-García Luis de la Cruz Juan A Virizuela Víctor Sánchez-Margalet Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells. PLoS ONE |
| title | Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells. |
| title_full | Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells. |
| title_fullStr | Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells. |
| title_full_unstemmed | Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells. |
| title_short | Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells. |
| title_sort | sam68 mediates the activation of insulin and leptin signalling in breast cancer cells |
| url | http://europepmc.org/articles/PMC4944952?pdf=render |
| work_keys_str_mv | AT antonioperezperez sam68mediatestheactivationofinsulinandleptinsignallinginbreastcancercells AT florasanchezjimenez sam68mediatestheactivationofinsulinandleptinsignallinginbreastcancercells AT teresavilarinogarcia sam68mediatestheactivationofinsulinandleptinsignallinginbreastcancercells AT luisdelacruz sam68mediatestheactivationofinsulinandleptinsignallinginbreastcancercells AT juanavirizuela sam68mediatestheactivationofinsulinandleptinsignallinginbreastcancercells AT victorsanchezmargalet sam68mediatestheactivationofinsulinandleptinsignallinginbreastcancercells |