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Published on: September 19, 2018
Characterization of low molecular weight protein tyrosine phosphatase isoforms in human breast cancer epithelial cell
Irina Alho1, Luís Costa, Manuel Bicho
1Genetics Laboratory, Lisbon Medical School, Edificio Egas Moniz, P1C, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal.
Background:
Low molecular weight protein tyrosine phosphatase (LMW-PTP) is a polymorphic protein with two major isoforms whose role in tumorigenesis is currently controversial.
Materials And Methods:
We characterized LMW-PTP genotype, isoform expression and activity in six different human breast cancer epithelial cell lines (ZR75, MDA-MB-231, MDA-MB-231BO, MCF7, MDA-MB-231BO2, MDA-MB-435) and compared them with MCF10A, a normal breast epithelial cell line.
Results:
mRNA expression of the slow isoform was increased in almost all breast cancer cell lines and that of the fast isoform was reduced (p<0.05) in all breast cancer cell lines. Regarding enzymatic activity, only MCF7 had significantly lower (p<0.05) LMW-PTP activity compared to MCF10A.
Conclusion:
Since these are novel and previously unreported findings, we propose that the differential expression of LMW-PTP fast and slow isoforms suggests their opposite roles in the tumorigenic process, with the fast isoform being anti-oncogenic and the slow isoform being oncogenic.
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