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Thrombospondin-1 (TSP-1) Stimulates Expression of Integrin alpha6 in Human Breast Carcinoma Cells: A Downstream Modulator of TSP-1-Induced Cellular Adhesion.

John AS, Rothman VL, Tuszynski GP - J Oncol (2010)

Bottom Line: This paper reports the novel finding that TSP-1 upregulates integrin alpha6 subunit in human keratinocytes and human breast cancer cells resulting in increased cell adhesion and tumor cell invasion.The effect of TSP-1 on alpha6 subunit expression was examined in human keratinocytes and breast adenocarcinoma cell lines (MDA-MB-231) treated with TSP-1 and in TSP-1 stably transfected breast cancer cells.These data suggest that TSP-1 plays an integral role in the attachment of cells to the ECM facilitating cell motility and angiogenesis.

View Article: PubMed Central - PubMed

Affiliation: Division of Pediatric Cardiology, Children's National Medical Center, George Washington University, Washington, DC 20052, USA.

ABSTRACT
Thrombospondin-1 (TSP-1) is involved in a variety of different cellular processes including cell adhesion, tumor progression, and angiogenesis. This paper reports the novel finding that TSP-1 upregulates integrin alpha6 subunit in human keratinocytes and human breast cancer cells resulting in increased cell adhesion and tumor cell invasion. The effect of TSP-1 on alpha6 subunit expression was examined in human keratinocytes and breast adenocarcinoma cell lines (MDA-MB-231) treated with TSP-1 and in TSP-1 stably transfected breast cancer cells. TSP-1 upregulated alpha6 message and protein in these cells as revealed by differential display, Northern and Western blot analysis and immunohistochemical localization studies. The increased expression of alpha6 was shown to mediate adhesion and invasion of these cells to laminin, a major component of the basement membrane and extracellular matrix (ECM). These data suggest that TSP-1 plays an integral role in the attachment of cells to the ECM facilitating cell motility and angiogenesis.

No MeSH data available.


Related in: MedlinePlus

TSP-1 induces integrin α6 mRNA expression in human breast cancer cells.  Two breast cancer cell lines (a) stably transfected TSP- 1 MDA-MB-435 cell lines with variable TSP-1 expression and (b) MDA-MB-231 cells treated with either buffer or TSP-1 (60 μg/mL) were analyzed by northern blot analysis for integrin α6 expression.  TSP-1 dose dependent response of integrin α6 was then assessed in the MDA-MB-231 (c). Blots were normalized to a 2.4 β-actin probe.  A pancreatic carcinoma cell line, BxPC3, was used as a positive control. (a) TSP-1 stably transfected TSP-1 cells.  1:  BxPC3 cell line, 2:  TH5 cells (vector control), 3:  TH29 cells (intermediate TSP-1 producer), and 4:  TH26 cells (high TSP-1 producer). (b) MDA-MB-231 cells.  1: BxPC3 cell line, 2:  buffer treatment, 3:  TSP-1 (1 hour), 4:  TSP-1 (6 hours), 5:  TSP-1 (12 hours), and 6:  TSP-1 (24 hours). Experiments were repeated three times and the results of a representative experiment are shown in the figure. (c) MDA-MB-231 cells.  1:  Buffer treatment, 2:  TSP-1 (20 μg/mL), 3:  TSP-1 (40 μg/mL), and 4:  TSP-1 (60 μg/mL).
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fig2: TSP-1 induces integrin α6 mRNA expression in human breast cancer cells. Two breast cancer cell lines (a) stably transfected TSP- 1 MDA-MB-435 cell lines with variable TSP-1 expression and (b) MDA-MB-231 cells treated with either buffer or TSP-1 (60 μg/mL) were analyzed by northern blot analysis for integrin α6 expression. TSP-1 dose dependent response of integrin α6 was then assessed in the MDA-MB-231 (c). Blots were normalized to a 2.4 β-actin probe. A pancreatic carcinoma cell line, BxPC3, was used as a positive control. (a) TSP-1 stably transfected TSP-1 cells. 1: BxPC3 cell line, 2: TH5 cells (vector control), 3: TH29 cells (intermediate TSP-1 producer), and 4: TH26 cells (high TSP-1 producer). (b) MDA-MB-231 cells. 1: BxPC3 cell line, 2: buffer treatment, 3: TSP-1 (1 hour), 4: TSP-1 (6 hours), 5: TSP-1 (12 hours), and 6: TSP-1 (24 hours). Experiments were repeated three times and the results of a representative experiment are shown in the figure. (c) MDA-MB-231 cells. 1: Buffer treatment, 2: TSP-1 (20 μg/mL), 3: TSP-1 (40 μg/mL), and 4: TSP-1 (60 μg/mL).

Mentions: To examine if TSP-1 upregulates integrin α6 production in human breast cancer cells, MDA-MB-231 cells were treated with TSP-1 (60 μg/mL) and total RNA was collected at various time points including 1 hour, 6 hours, 12 hours, and 24 hours. The 236 base pair band isolated through differential display was used as the probe for northern blot analysis. The results show that integrin α6 expression appears to increase after a 24 hour incubation with TSP-1 with some downregulation seen at the one hour time point (see Figure 2(b)). In addition, TSP-1 stably transfected MDA-MB-435 cells were also examined for integrin α6 mRNA expression. Three cells lines were examined: a vector control (TH5), an intermediate TSP-1 producer (TH29), and a high TSP-1 producer (TH26). The results show that the highest level of integrin α6 mRNA occurred in the high TSP-1 producer (TH26) (Figure 2(a)). The intermediate producer showed more integrin α6 mRNA production than the vector control (TH5) but less than the TH26 cell line. MDA-MB-231 cells were then incubated with varying concentrations of TSP-1 for a period of 24 hours. The highest level of expression occurred with a TSP-1 dosage of 60 μg/mL. This data support the conclusion that TSP-1 not only upregulates integrin α6 mRNA expression, but that it does so in a dose and time dependent fashion.


Thrombospondin-1 (TSP-1) Stimulates Expression of Integrin alpha6 in Human Breast Carcinoma Cells: A Downstream Modulator of TSP-1-Induced Cellular Adhesion.

John AS, Rothman VL, Tuszynski GP - J Oncol (2010)

TSP-1 induces integrin α6 mRNA expression in human breast cancer cells.  Two breast cancer cell lines (a) stably transfected TSP- 1 MDA-MB-435 cell lines with variable TSP-1 expression and (b) MDA-MB-231 cells treated with either buffer or TSP-1 (60 μg/mL) were analyzed by northern blot analysis for integrin α6 expression.  TSP-1 dose dependent response of integrin α6 was then assessed in the MDA-MB-231 (c). Blots were normalized to a 2.4 β-actin probe.  A pancreatic carcinoma cell line, BxPC3, was used as a positive control. (a) TSP-1 stably transfected TSP-1 cells.  1:  BxPC3 cell line, 2:  TH5 cells (vector control), 3:  TH29 cells (intermediate TSP-1 producer), and 4:  TH26 cells (high TSP-1 producer). (b) MDA-MB-231 cells.  1: BxPC3 cell line, 2:  buffer treatment, 3:  TSP-1 (1 hour), 4:  TSP-1 (6 hours), 5:  TSP-1 (12 hours), and 6:  TSP-1 (24 hours). Experiments were repeated three times and the results of a representative experiment are shown in the figure. (c) MDA-MB-231 cells.  1:  Buffer treatment, 2:  TSP-1 (20 μg/mL), 3:  TSP-1 (40 μg/mL), and 4:  TSP-1 (60 μg/mL).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2902750&req=5

fig2: TSP-1 induces integrin α6 mRNA expression in human breast cancer cells. Two breast cancer cell lines (a) stably transfected TSP- 1 MDA-MB-435 cell lines with variable TSP-1 expression and (b) MDA-MB-231 cells treated with either buffer or TSP-1 (60 μg/mL) were analyzed by northern blot analysis for integrin α6 expression. TSP-1 dose dependent response of integrin α6 was then assessed in the MDA-MB-231 (c). Blots were normalized to a 2.4 β-actin probe. A pancreatic carcinoma cell line, BxPC3, was used as a positive control. (a) TSP-1 stably transfected TSP-1 cells. 1: BxPC3 cell line, 2: TH5 cells (vector control), 3: TH29 cells (intermediate TSP-1 producer), and 4: TH26 cells (high TSP-1 producer). (b) MDA-MB-231 cells. 1: BxPC3 cell line, 2: buffer treatment, 3: TSP-1 (1 hour), 4: TSP-1 (6 hours), 5: TSP-1 (12 hours), and 6: TSP-1 (24 hours). Experiments were repeated three times and the results of a representative experiment are shown in the figure. (c) MDA-MB-231 cells. 1: Buffer treatment, 2: TSP-1 (20 μg/mL), 3: TSP-1 (40 μg/mL), and 4: TSP-1 (60 μg/mL).
Mentions: To examine if TSP-1 upregulates integrin α6 production in human breast cancer cells, MDA-MB-231 cells were treated with TSP-1 (60 μg/mL) and total RNA was collected at various time points including 1 hour, 6 hours, 12 hours, and 24 hours. The 236 base pair band isolated through differential display was used as the probe for northern blot analysis. The results show that integrin α6 expression appears to increase after a 24 hour incubation with TSP-1 with some downregulation seen at the one hour time point (see Figure 2(b)). In addition, TSP-1 stably transfected MDA-MB-435 cells were also examined for integrin α6 mRNA expression. Three cells lines were examined: a vector control (TH5), an intermediate TSP-1 producer (TH29), and a high TSP-1 producer (TH26). The results show that the highest level of integrin α6 mRNA occurred in the high TSP-1 producer (TH26) (Figure 2(a)). The intermediate producer showed more integrin α6 mRNA production than the vector control (TH5) but less than the TH26 cell line. MDA-MB-231 cells were then incubated with varying concentrations of TSP-1 for a period of 24 hours. The highest level of expression occurred with a TSP-1 dosage of 60 μg/mL. This data support the conclusion that TSP-1 not only upregulates integrin α6 mRNA expression, but that it does so in a dose and time dependent fashion.

Bottom Line: This paper reports the novel finding that TSP-1 upregulates integrin alpha6 subunit in human keratinocytes and human breast cancer cells resulting in increased cell adhesion and tumor cell invasion.The effect of TSP-1 on alpha6 subunit expression was examined in human keratinocytes and breast adenocarcinoma cell lines (MDA-MB-231) treated with TSP-1 and in TSP-1 stably transfected breast cancer cells.These data suggest that TSP-1 plays an integral role in the attachment of cells to the ECM facilitating cell motility and angiogenesis.

View Article: PubMed Central - PubMed

Affiliation: Division of Pediatric Cardiology, Children's National Medical Center, George Washington University, Washington, DC 20052, USA.

ABSTRACT
Thrombospondin-1 (TSP-1) is involved in a variety of different cellular processes including cell adhesion, tumor progression, and angiogenesis. This paper reports the novel finding that TSP-1 upregulates integrin alpha6 subunit in human keratinocytes and human breast cancer cells resulting in increased cell adhesion and tumor cell invasion. The effect of TSP-1 on alpha6 subunit expression was examined in human keratinocytes and breast adenocarcinoma cell lines (MDA-MB-231) treated with TSP-1 and in TSP-1 stably transfected breast cancer cells. TSP-1 upregulated alpha6 message and protein in these cells as revealed by differential display, Northern and Western blot analysis and immunohistochemical localization studies. The increased expression of alpha6 was shown to mediate adhesion and invasion of these cells to laminin, a major component of the basement membrane and extracellular matrix (ECM). These data suggest that TSP-1 plays an integral role in the attachment of cells to the ECM facilitating cell motility and angiogenesis.

No MeSH data available.


Related in: MedlinePlus