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MUC4 stabilizes HER2 expression and maintains the cancer stem cell population in ovarian cancer cells.

Ponnusamy MP, Seshacharyulu P, Vaz A, Dey P, Batra SK - J Ovarian Res (2011)

Bottom Line: MUC4 overexpressed SKOV3 cells showed an increased expression of HER2 compared to control cells.These studies demonstrate that MUC4 overexpression leads to an enriched ovarian cancer stem cell population either directly or indirectly through HER2.In future, this study would be helpful for MUC4-directed therapy for the ovarian cancer stem cell population.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA. sbatra@unmc.edu.

ABSTRACT

Background: Recent evidence has suggested that the capability of cancer to grow, propagate and relapse after therapy is dependent on a small subset of the cell population within the tumor, called cancer stem cells. Therefore, this subpopulation of cells needs to be targeted with different approaches by identification of unique stem-cell specific target antigens. One of the well known tumor antigens is the epithelial cell mucin MUC4, which is aberrantly expressed in ovarian cancer as compared to the normal ovary and plays a pivotal role in the aggressiveness and metastasis of ovarian cancer cells. In the present study, we aimed to analyze the cancer stem cell population in MUC4 overexpressed ovarian cancer cells.

Methods: MUC4 was ectopically overexpressed in SKOV3 ovarian cancer cells. Western blot analysis was performed for MUC4, HER2, CD133, ALDH1 and Shh expression in MUC4 overexpressed cells. Confocal analysis of MUC4, HER2 and CD133 was also done in the MUC4 overexpressed cells. CD133 and Hoechst33342 dye staining was used to analyze the cancer stem cell population via FACS method in SKOV3-MUC4 cells.

Results: MUC4 overexpressed SKOV3 cells showed an increased expression of HER2 compared to control cells. MUC4 overexpression leads to increased (0.1%) side population (SP) and CD133-positive cancer stem cells compared to the control cells. Interestingly, the tumor sphere type circular colony formation was observed only in the MUC4 overexpressed ovarian cancer cells. Furthermore, the cancer stem cell marker CD133 was expressed along with MUC4 in the isolated circular colonies as analyzed by both confocal and western blot analysis. HER2 and cancer stem cell specific marker ALDH1 along with Shh, a self-renewal marker, showed increased expression in the isolated circular colonies compared to MUC4-transfected cells.

Conclusion: These studies demonstrate that MUC4 overexpression leads to an enriched ovarian cancer stem cell population either directly or indirectly through HER2. In future, this study would be helpful for MUC4-directed therapy for the ovarian cancer stem cell population.

No MeSH data available.


Related in: MedlinePlus

Colony formation in MUC4-trasfected cells. SKOV3-Vector and SKOV3-MUC4 cells were seeded in equal confluence and allowed to grow for up to 18 days. After the full confluence we observed a tumor sphere-like colony formation on the top of the cells. Circular colony formation was observed only in MUC4 overexpressed SKOV3 cells and no colonies were formed in SKOV3-vector cells. (Original magnification 100X upper panel and 40X lower panel).
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Figure 3: Colony formation in MUC4-trasfected cells. SKOV3-Vector and SKOV3-MUC4 cells were seeded in equal confluence and allowed to grow for up to 18 days. After the full confluence we observed a tumor sphere-like colony formation on the top of the cells. Circular colony formation was observed only in MUC4 overexpressed SKOV3 cells and no colonies were formed in SKOV3-vector cells. (Original magnification 100X upper panel and 40X lower panel).

Mentions: Formation of spherical colonies has been reported to be a property characteristic of stem/progenitor cells and verifies a high developmental and proliferative potency of side population cells [11]. Interestingly, in our study we observed circular colony formation in MUC4-transfected SKOV3 cells when it became over confluent after three weeks (Figure 3). In contrast, no colony formation was observed in vector-transfected SKOV3 cells (Figure 3). We further isolated these colonies for the stem/progenitor marker analysis.


MUC4 stabilizes HER2 expression and maintains the cancer stem cell population in ovarian cancer cells.

Ponnusamy MP, Seshacharyulu P, Vaz A, Dey P, Batra SK - J Ovarian Res (2011)

Colony formation in MUC4-trasfected cells. SKOV3-Vector and SKOV3-MUC4 cells were seeded in equal confluence and allowed to grow for up to 18 days. After the full confluence we observed a tumor sphere-like colony formation on the top of the cells. Circular colony formation was observed only in MUC4 overexpressed SKOV3 cells and no colonies were formed in SKOV3-vector cells. (Original magnification 100X upper panel and 40X lower panel).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3111401&req=5

Figure 3: Colony formation in MUC4-trasfected cells. SKOV3-Vector and SKOV3-MUC4 cells were seeded in equal confluence and allowed to grow for up to 18 days. After the full confluence we observed a tumor sphere-like colony formation on the top of the cells. Circular colony formation was observed only in MUC4 overexpressed SKOV3 cells and no colonies were formed in SKOV3-vector cells. (Original magnification 100X upper panel and 40X lower panel).
Mentions: Formation of spherical colonies has been reported to be a property characteristic of stem/progenitor cells and verifies a high developmental and proliferative potency of side population cells [11]. Interestingly, in our study we observed circular colony formation in MUC4-transfected SKOV3 cells when it became over confluent after three weeks (Figure 3). In contrast, no colony formation was observed in vector-transfected SKOV3 cells (Figure 3). We further isolated these colonies for the stem/progenitor marker analysis.

Bottom Line: MUC4 overexpressed SKOV3 cells showed an increased expression of HER2 compared to control cells.These studies demonstrate that MUC4 overexpression leads to an enriched ovarian cancer stem cell population either directly or indirectly through HER2.In future, this study would be helpful for MUC4-directed therapy for the ovarian cancer stem cell population.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA. sbatra@unmc.edu.

ABSTRACT

Background: Recent evidence has suggested that the capability of cancer to grow, propagate and relapse after therapy is dependent on a small subset of the cell population within the tumor, called cancer stem cells. Therefore, this subpopulation of cells needs to be targeted with different approaches by identification of unique stem-cell specific target antigens. One of the well known tumor antigens is the epithelial cell mucin MUC4, which is aberrantly expressed in ovarian cancer as compared to the normal ovary and plays a pivotal role in the aggressiveness and metastasis of ovarian cancer cells. In the present study, we aimed to analyze the cancer stem cell population in MUC4 overexpressed ovarian cancer cells.

Methods: MUC4 was ectopically overexpressed in SKOV3 ovarian cancer cells. Western blot analysis was performed for MUC4, HER2, CD133, ALDH1 and Shh expression in MUC4 overexpressed cells. Confocal analysis of MUC4, HER2 and CD133 was also done in the MUC4 overexpressed cells. CD133 and Hoechst33342 dye staining was used to analyze the cancer stem cell population via FACS method in SKOV3-MUC4 cells.

Results: MUC4 overexpressed SKOV3 cells showed an increased expression of HER2 compared to control cells. MUC4 overexpression leads to increased (0.1%) side population (SP) and CD133-positive cancer stem cells compared to the control cells. Interestingly, the tumor sphere type circular colony formation was observed only in the MUC4 overexpressed ovarian cancer cells. Furthermore, the cancer stem cell marker CD133 was expressed along with MUC4 in the isolated circular colonies as analyzed by both confocal and western blot analysis. HER2 and cancer stem cell specific marker ALDH1 along with Shh, a self-renewal marker, showed increased expression in the isolated circular colonies compared to MUC4-transfected cells.

Conclusion: These studies demonstrate that MUC4 overexpression leads to an enriched ovarian cancer stem cell population either directly or indirectly through HER2. In future, this study would be helpful for MUC4-directed therapy for the ovarian cancer stem cell population.

No MeSH data available.


Related in: MedlinePlus