Limits...
Physical Intimacy of Breast Cancer Cells with Mesenchymal Stem Cells Elicits Trastuzumab Resistance through Src Activation.

Daverey A, Drain AP, Kidambi S - Sci Rep (2015)

Bottom Line: The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors.To our knowledge, this is the first report that showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs.Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE, 68588.

ABSTRACT
The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors. Here, we demonstrate that the physical contact of breast cancer cells with mesenchymal stem cells (MSCs) is a potential modulator of trastuzumab response by activation of nonreceptor tyrosine kinase c-Src and down regulation of phosphatase and tensin homolog (PTEN). Using an in vitro patterned breast cancer/MSC co-culture model, we find that the presence of MSCs results in Src activation that is missing in cancer cells monoculture, transwell co-culture, and cells treated with MSCs conditioned media. Interestingly, the co-culture model also results in PTEN loss and activation of PI3K/AKT pathway that has been demonstrated as fundamental proliferative and survival pathways in clinical settings. To our knowledge, this is the first report that showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs. In addition, breast cancer cells in co-culture with MSCs conferred trastuzumab resistance in vitro as observed in the lack of inhibition of proliferative and migrative properties of the cancer cells. Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.

No MeSH data available.


Related in: MedlinePlus

Physical contact of MSCs with breast cancer cells activates Src.(a) Upper panel shows representative immunoblots of Src detected in BT-474 and 21MT-1 cells co-cultured with MSCs, transwell co-culture or MSCs-CM. (b) Lower panel shows respective densitometry of bands; monocultures of BT-474 and 21MT-1 were used as control. Asterisks represent statistical significant differences in change in expression of Src in co-cultures samples compared with monoculture control. Data are mean ± SD; n = 3 independent experiments; **p < 0.01 compared with control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4561910&req=5

f1: Physical contact of MSCs with breast cancer cells activates Src.(a) Upper panel shows representative immunoblots of Src detected in BT-474 and 21MT-1 cells co-cultured with MSCs, transwell co-culture or MSCs-CM. (b) Lower panel shows respective densitometry of bands; monocultures of BT-474 and 21MT-1 were used as control. Asterisks represent statistical significant differences in change in expression of Src in co-cultures samples compared with monoculture control. Data are mean ± SD; n = 3 independent experiments; **p < 0.01 compared with control.

Mentions: To test the hypothesis that physical intimacy and not soluble factors from MSCs activates Src, we established four different systems to recreate these interactions. Human breast cancer cells were cultured 1) alone (monoculture); 2) treated with conditioned media from MSCs (MSCs-CM) to introduce secreted soluble factors into breast cancer cells; 3) co-culture of breast cancer cells with MSCs using transwell (Boyden Chamber) to monitor cell-cell interactions through soluble factors derived from each cells and 4) random co-culture with MSCs which contains the physical contact and ability to share soluble signaling factors (co-culture). We employed two developmentally distinct human breast cell lines for this study: 1) BT474 (HER2+ invasive breast cancer cells), and 2) 21MT-1 (stable patient-derived metastatic breast cancer cells isolated from the metastatic pleural effusion). We specifically chose 21MT-1 cells due to recent reports highlighting the 21T cell line’s ability to mimic in vivo cancer development and behavior within the in vitro enviroment through stage specific cell proliferation, migration, morpholgy, polarization, and gene expression profiles, and its consequent potential for usage as a valuable translational disease model for breast cancer34. A significant (p < 0.01) increase in Src protein expression was observed in random co-cultures of breast cancer cells and MSCs, while no significant change (p > 0.05) was observed in cells exposed to MSCs-CM, transwell co-culture, and monoculture of breast cancer cells (Fig. 1). Furthermore, no significant increase in Src expression was observed in breast cancer cells co-cultured with MCF10A cells (mammary epithelial cells), suggesting that this is a MSC-specific phenomena (Supplementary Fig. 1). This data suggest that the physical contact of breast cancer cells with MSCs is critical for MSCs mediated regulation of Src, and one of the possible mechanisms for Src activation in aggressive breast cancers.


Physical Intimacy of Breast Cancer Cells with Mesenchymal Stem Cells Elicits Trastuzumab Resistance through Src Activation.

Daverey A, Drain AP, Kidambi S - Sci Rep (2015)

Physical contact of MSCs with breast cancer cells activates Src.(a) Upper panel shows representative immunoblots of Src detected in BT-474 and 21MT-1 cells co-cultured with MSCs, transwell co-culture or MSCs-CM. (b) Lower panel shows respective densitometry of bands; monocultures of BT-474 and 21MT-1 were used as control. Asterisks represent statistical significant differences in change in expression of Src in co-cultures samples compared with monoculture control. Data are mean ± SD; n = 3 independent experiments; **p < 0.01 compared with control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561910&req=5

f1: Physical contact of MSCs with breast cancer cells activates Src.(a) Upper panel shows representative immunoblots of Src detected in BT-474 and 21MT-1 cells co-cultured with MSCs, transwell co-culture or MSCs-CM. (b) Lower panel shows respective densitometry of bands; monocultures of BT-474 and 21MT-1 were used as control. Asterisks represent statistical significant differences in change in expression of Src in co-cultures samples compared with monoculture control. Data are mean ± SD; n = 3 independent experiments; **p < 0.01 compared with control.
Mentions: To test the hypothesis that physical intimacy and not soluble factors from MSCs activates Src, we established four different systems to recreate these interactions. Human breast cancer cells were cultured 1) alone (monoculture); 2) treated with conditioned media from MSCs (MSCs-CM) to introduce secreted soluble factors into breast cancer cells; 3) co-culture of breast cancer cells with MSCs using transwell (Boyden Chamber) to monitor cell-cell interactions through soluble factors derived from each cells and 4) random co-culture with MSCs which contains the physical contact and ability to share soluble signaling factors (co-culture). We employed two developmentally distinct human breast cell lines for this study: 1) BT474 (HER2+ invasive breast cancer cells), and 2) 21MT-1 (stable patient-derived metastatic breast cancer cells isolated from the metastatic pleural effusion). We specifically chose 21MT-1 cells due to recent reports highlighting the 21T cell line’s ability to mimic in vivo cancer development and behavior within the in vitro enviroment through stage specific cell proliferation, migration, morpholgy, polarization, and gene expression profiles, and its consequent potential for usage as a valuable translational disease model for breast cancer34. A significant (p < 0.01) increase in Src protein expression was observed in random co-cultures of breast cancer cells and MSCs, while no significant change (p > 0.05) was observed in cells exposed to MSCs-CM, transwell co-culture, and monoculture of breast cancer cells (Fig. 1). Furthermore, no significant increase in Src expression was observed in breast cancer cells co-cultured with MCF10A cells (mammary epithelial cells), suggesting that this is a MSC-specific phenomena (Supplementary Fig. 1). This data suggest that the physical contact of breast cancer cells with MSCs is critical for MSCs mediated regulation of Src, and one of the possible mechanisms for Src activation in aggressive breast cancers.

Bottom Line: The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors.To our knowledge, this is the first report that showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs.Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE, 68588.

ABSTRACT
The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors. Here, we demonstrate that the physical contact of breast cancer cells with mesenchymal stem cells (MSCs) is a potential modulator of trastuzumab response by activation of nonreceptor tyrosine kinase c-Src and down regulation of phosphatase and tensin homolog (PTEN). Using an in vitro patterned breast cancer/MSC co-culture model, we find that the presence of MSCs results in Src activation that is missing in cancer cells monoculture, transwell co-culture, and cells treated with MSCs conditioned media. Interestingly, the co-culture model also results in PTEN loss and activation of PI3K/AKT pathway that has been demonstrated as fundamental proliferative and survival pathways in clinical settings. To our knowledge, this is the first report that showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs. In addition, breast cancer cells in co-culture with MSCs conferred trastuzumab resistance in vitro as observed in the lack of inhibition of proliferative and migrative properties of the cancer cells. Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.

No MeSH data available.


Related in: MedlinePlus