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Mammaglobin as a potential molecular target for breast cancer drug delivery.

Zuo L, Li L, Wang Q, Fleming TP, You S - Cancer Cell Int. (2009)

Bottom Line: Recently, several groups of researchers proposed a number of therapeutic strategies targeting this molecule.We provided several evidences to demonstrate the presence of the membrane-associated MAM.To test whether the membrane-associated MAM can serve as a molecular target for drug delivery, we conjugated anti-MAM antibody to human low-density lipoprotein (LDL) and loaded doxorubicin (Dox) in the core of LDL.

View Article: PubMed Central - HTML - PubMed

Affiliation: Atlanta Research and Education Foundation, Atlanta VA Medical Center (151), Decatur, GA 30033, USA. arefzuo@gmail.com

ABSTRACT

Background: Mammaglobin (MAM) has been used as a specific molecular marker for breast cancer diagnosis. Recently, several groups of researchers proposed a number of therapeutic strategies targeting this molecule. Some of the strategies are based upon an essential but not demonstrated hypothesis - mammaglobin is associated with the surface of breast cancer cells, which strongly disputes the therapeutic strategies.

Results: We conducted a computer-based predictive analysis and identified a small fragment at the N-end of MAM as a potential transmembrane domain. We provided several evidences to demonstrate the presence of the membrane-associated MAM. We isolated the membrane protein components from known MAM positive breast cancer cells (MDA-MB361 and MDA-MB415). We showed that about 22-64% of MAM proteins, depending upon the types of the cancer cells, directly attached on the membrane of breast cancer cells, by Western blotting assays. To directly visualize the presence of the membrane-bound MAM protein, we incubated the MAM positive cancer cells with FITC labeled anti-MAM antibody, and observed clear fluorescent signals on the surface of the cells. In studying the MAM protein distribution in human breast cancer tissues, we first identified two immunostain patterns that are associated with the membrane-bound MAM: the membrane stain pattern and luminary surface stain pattern. To test whether the membrane-associated MAM can serve as a molecular target for drug delivery, we conjugated anti-MAM antibody to human low-density lipoprotein (LDL) and loaded doxorubicin (Dox) in the core of LDL. Specific binding and cytotoxicity of the MAM targeted and Dox loaded LDL was tested in the MAM positive breast cancer cells in vitro.

Conclusion: We first showed that some of MAM protein directly associated with the surface of breast cancer cells. The membrane-associated MAM protein may be utilized as a useful molecular marker for breast cancer targeted drug delivery.

No MeSH data available.


Related in: MedlinePlus

Detection of membrane associated MAM protein on breast cancer cells. The Western blot assay shows the specific MAM protein bands (10.5 kDa) in both membranous and cytoplasmic proteins of MDA-MB361 (361) and MDA-MB415 (415) cells; while no specific bands in the membranous and cytoplasmic proteins of MB231 cells. The bar graph represents the quantitative measurements of Western blot assays from four separated experiments (mean ± SE).
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Figure 2: Detection of membrane associated MAM protein on breast cancer cells. The Western blot assay shows the specific MAM protein bands (10.5 kDa) in both membranous and cytoplasmic proteins of MDA-MB361 (361) and MDA-MB415 (415) cells; while no specific bands in the membranous and cytoplasmic proteins of MB231 cells. The bar graph represents the quantitative measurements of Western blot assays from four separated experiments (mean ± SE).

Mentions: To examine whether MAM is a membrane-associated protein in breast cancer cells, we isolated the membrane and cytosol proteins from the cultured MDA-MB415 (MB415), MDA-MB361 (MB361), and MDA-MB231 (MB231) breast cancer cells respectively. We used Na+-K+-ATPase as the membrane marker and α-tubulin as the cytosol marker. By performing Western blot assays, we detected MAM protein existing at both membrane and cytosol fractions in MB361 and MB415 cancer cells, but not in the MB231 cells (Figure 2). The membrane and cytosol associated MAM proteins were quantitatively evaluated based on the scanned intensities of the specific bands for MAM by normalization of GADPH bands. The membrane-associated MAM protein of MB415 cells was estimated 49.4% more than that of the MB316 cells. The ratios of the membrane-associated MAM protein vs. cytosolic MAM were about 22.2% and 64.1% in the MB361 and MB415 cells respectively.


Mammaglobin as a potential molecular target for breast cancer drug delivery.

Zuo L, Li L, Wang Q, Fleming TP, You S - Cancer Cell Int. (2009)

Detection of membrane associated MAM protein on breast cancer cells. The Western blot assay shows the specific MAM protein bands (10.5 kDa) in both membranous and cytoplasmic proteins of MDA-MB361 (361) and MDA-MB415 (415) cells; while no specific bands in the membranous and cytoplasmic proteins of MB231 cells. The bar graph represents the quantitative measurements of Western blot assays from four separated experiments (mean ± SE).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2662795&req=5

Figure 2: Detection of membrane associated MAM protein on breast cancer cells. The Western blot assay shows the specific MAM protein bands (10.5 kDa) in both membranous and cytoplasmic proteins of MDA-MB361 (361) and MDA-MB415 (415) cells; while no specific bands in the membranous and cytoplasmic proteins of MB231 cells. The bar graph represents the quantitative measurements of Western blot assays from four separated experiments (mean ± SE).
Mentions: To examine whether MAM is a membrane-associated protein in breast cancer cells, we isolated the membrane and cytosol proteins from the cultured MDA-MB415 (MB415), MDA-MB361 (MB361), and MDA-MB231 (MB231) breast cancer cells respectively. We used Na+-K+-ATPase as the membrane marker and α-tubulin as the cytosol marker. By performing Western blot assays, we detected MAM protein existing at both membrane and cytosol fractions in MB361 and MB415 cancer cells, but not in the MB231 cells (Figure 2). The membrane and cytosol associated MAM proteins were quantitatively evaluated based on the scanned intensities of the specific bands for MAM by normalization of GADPH bands. The membrane-associated MAM protein of MB415 cells was estimated 49.4% more than that of the MB316 cells. The ratios of the membrane-associated MAM protein vs. cytosolic MAM were about 22.2% and 64.1% in the MB361 and MB415 cells respectively.

Bottom Line: Recently, several groups of researchers proposed a number of therapeutic strategies targeting this molecule.We provided several evidences to demonstrate the presence of the membrane-associated MAM.To test whether the membrane-associated MAM can serve as a molecular target for drug delivery, we conjugated anti-MAM antibody to human low-density lipoprotein (LDL) and loaded doxorubicin (Dox) in the core of LDL.

View Article: PubMed Central - HTML - PubMed

Affiliation: Atlanta Research and Education Foundation, Atlanta VA Medical Center (151), Decatur, GA 30033, USA. arefzuo@gmail.com

ABSTRACT

Background: Mammaglobin (MAM) has been used as a specific molecular marker for breast cancer diagnosis. Recently, several groups of researchers proposed a number of therapeutic strategies targeting this molecule. Some of the strategies are based upon an essential but not demonstrated hypothesis - mammaglobin is associated with the surface of breast cancer cells, which strongly disputes the therapeutic strategies.

Results: We conducted a computer-based predictive analysis and identified a small fragment at the N-end of MAM as a potential transmembrane domain. We provided several evidences to demonstrate the presence of the membrane-associated MAM. We isolated the membrane protein components from known MAM positive breast cancer cells (MDA-MB361 and MDA-MB415). We showed that about 22-64% of MAM proteins, depending upon the types of the cancer cells, directly attached on the membrane of breast cancer cells, by Western blotting assays. To directly visualize the presence of the membrane-bound MAM protein, we incubated the MAM positive cancer cells with FITC labeled anti-MAM antibody, and observed clear fluorescent signals on the surface of the cells. In studying the MAM protein distribution in human breast cancer tissues, we first identified two immunostain patterns that are associated with the membrane-bound MAM: the membrane stain pattern and luminary surface stain pattern. To test whether the membrane-associated MAM can serve as a molecular target for drug delivery, we conjugated anti-MAM antibody to human low-density lipoprotein (LDL) and loaded doxorubicin (Dox) in the core of LDL. Specific binding and cytotoxicity of the MAM targeted and Dox loaded LDL was tested in the MAM positive breast cancer cells in vitro.

Conclusion: We first showed that some of MAM protein directly associated with the surface of breast cancer cells. The membrane-associated MAM protein may be utilized as a useful molecular marker for breast cancer targeted drug delivery.

No MeSH data available.


Related in: MedlinePlus