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Decreased expression of the mannose 6-phosphate/insulin-like growth factor-II receptor promotes growth of human breast cancer cells.

Chen Z, Ge Y, Landman N, Kang JX - BMC Cancer (2002)

Bottom Line: Our results showed that infection of MCF-7 cells with the adenovirus carrying a ribozyme targeted against the M6P/IGF2R mRNA dramatically reduced the level of transcripts and the functional activity of M6P/IGF2R in these cells.Furthermore, decreased expression of M6P/IGF2R enhanced IGF-II-induced proliferation and reduced cell susceptibility to TNF-induced apoptosis.This study also demonstrates that adenoviral delivery of the ribozyme provides a useful tool for investigating the role of M6P/IGF2R in regulation of cell growth.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston 02114, USA. j8018@yahoo.com

ABSTRACT

Background: Loss or mutation of the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R) has been found in breast cancer. However, whether or not decreased levels of functional M6P/IGF2R directly contribute to the process of carcinogenesis needs to be further verified by functional studies.

Methods: In this study, using viral and ribozyme strategies we reduced the expression of M6P/IGF2R in human breast cancer cells and then examined the effect on growth and apoptosis of these cells.

Results: Our results showed that infection of MCF-7 cells with the adenovirus carrying a ribozyme targeted against the M6P/IGF2R mRNA dramatically reduced the level of transcripts and the functional activity of M6P/IGF2R in these cells. Accordingly, cells treated with a ribozyme exhibited a higher growth rate and a lower apoptotic index than control cells (infected with a control vector). Furthermore, decreased expression of M6P/IGF2R enhanced IGF-II-induced proliferation and reduced cell susceptibility to TNF-induced apoptosis.

Conclusions: These results suggest that M6P/IGF2R functions as a growth suppressor and its loss or mutation may contribute to development and progression of cancer. This study also demonstrates that adenoviral delivery of the ribozyme provides a useful tool for investigating the role of M6P/IGF2R in regulation of cell growth.

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RT-PCR detection of the M6P/IGF2R ribozyme expressed in MCF-7 cells. MCF-7 cells were infected with Ad.GFP.Rz-IGF2R or Ad.GFP. Seventy two hrs post infection, cells were collected and total RNA extracted. The presence of the ribozyme was detected by RT-PCR using primers specific to the ribozyme. Lane 1: Cells infected with Ad.GFP; Lane 2: cells infected with Ad.GFP.Rz-IGF2R.
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Figure 2: RT-PCR detection of the M6P/IGF2R ribozyme expressed in MCF-7 cells. MCF-7 cells were infected with Ad.GFP.Rz-IGF2R or Ad.GFP. Seventy two hrs post infection, cells were collected and total RNA extracted. The presence of the ribozyme was detected by RT-PCR using primers specific to the ribozyme. Lane 1: Cells infected with Ad.GFP; Lane 2: cells infected with Ad.GFP.Rz-IGF2R.

Mentions: To test whether infection of cultured cells with the Ad-GFP/Rz-IGF2R can induce the expression of the ribozyme (Rz-IGF2R), total RNA was extracted from cells infected with Ad-GFP/IGF2R-Rz or Ad-GFP, and subjected to RT-PCR using ribozyme-specific primers. As shown in Fig. 2, infection of MCF-7 cells with Ad-GFP/Rz-IGF2R resulted in positive expression of the ribozyme as determined by RT-PCR. As expected, the ribozyme sequence-specific primers produced a 430-bp PCR fragment only in cells infected with Ad-GFP/Rz-IGF2R, but not in cell infected with the control viral vector Ad-GFP.


Decreased expression of the mannose 6-phosphate/insulin-like growth factor-II receptor promotes growth of human breast cancer cells.

Chen Z, Ge Y, Landman N, Kang JX - BMC Cancer (2002)

RT-PCR detection of the M6P/IGF2R ribozyme expressed in MCF-7 cells. MCF-7 cells were infected with Ad.GFP.Rz-IGF2R or Ad.GFP. Seventy two hrs post infection, cells were collected and total RNA extracted. The presence of the ribozyme was detected by RT-PCR using primers specific to the ribozyme. Lane 1: Cells infected with Ad.GFP; Lane 2: cells infected with Ad.GFP.Rz-IGF2R.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC117795&req=5

Figure 2: RT-PCR detection of the M6P/IGF2R ribozyme expressed in MCF-7 cells. MCF-7 cells were infected with Ad.GFP.Rz-IGF2R or Ad.GFP. Seventy two hrs post infection, cells were collected and total RNA extracted. The presence of the ribozyme was detected by RT-PCR using primers specific to the ribozyme. Lane 1: Cells infected with Ad.GFP; Lane 2: cells infected with Ad.GFP.Rz-IGF2R.
Mentions: To test whether infection of cultured cells with the Ad-GFP/Rz-IGF2R can induce the expression of the ribozyme (Rz-IGF2R), total RNA was extracted from cells infected with Ad-GFP/IGF2R-Rz or Ad-GFP, and subjected to RT-PCR using ribozyme-specific primers. As shown in Fig. 2, infection of MCF-7 cells with Ad-GFP/Rz-IGF2R resulted in positive expression of the ribozyme as determined by RT-PCR. As expected, the ribozyme sequence-specific primers produced a 430-bp PCR fragment only in cells infected with Ad-GFP/Rz-IGF2R, but not in cell infected with the control viral vector Ad-GFP.

Bottom Line: Our results showed that infection of MCF-7 cells with the adenovirus carrying a ribozyme targeted against the M6P/IGF2R mRNA dramatically reduced the level of transcripts and the functional activity of M6P/IGF2R in these cells.Furthermore, decreased expression of M6P/IGF2R enhanced IGF-II-induced proliferation and reduced cell susceptibility to TNF-induced apoptosis.This study also demonstrates that adenoviral delivery of the ribozyme provides a useful tool for investigating the role of M6P/IGF2R in regulation of cell growth.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston 02114, USA. j8018@yahoo.com

ABSTRACT

Background: Loss or mutation of the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R) has been found in breast cancer. However, whether or not decreased levels of functional M6P/IGF2R directly contribute to the process of carcinogenesis needs to be further verified by functional studies.

Methods: In this study, using viral and ribozyme strategies we reduced the expression of M6P/IGF2R in human breast cancer cells and then examined the effect on growth and apoptosis of these cells.

Results: Our results showed that infection of MCF-7 cells with the adenovirus carrying a ribozyme targeted against the M6P/IGF2R mRNA dramatically reduced the level of transcripts and the functional activity of M6P/IGF2R in these cells. Accordingly, cells treated with a ribozyme exhibited a higher growth rate and a lower apoptotic index than control cells (infected with a control vector). Furthermore, decreased expression of M6P/IGF2R enhanced IGF-II-induced proliferation and reduced cell susceptibility to TNF-induced apoptosis.

Conclusions: These results suggest that M6P/IGF2R functions as a growth suppressor and its loss or mutation may contribute to development and progression of cancer. This study also demonstrates that adenoviral delivery of the ribozyme provides a useful tool for investigating the role of M6P/IGF2R in regulation of cell growth.

Show MeSH
Related in: MedlinePlus