Influence Of Rab15 Overexpression On Growth And Migration Of Breast Cancer Cells

Rab protein is the largest family within the Ras superfamily,and is involved in intracellular protein transport.The dysfunction of Rab proteins is related to many diseases.In mammals,more than 70 different RAB and RAB-like proteins have been characterized so far.Although we have studied most of these proteins and have achieved some success,one of Rab family members,Rab 15 has not been investigated in detail.This study prefers to explore the localization of Rab 15 protein in cells and its biological function.We explored the localization of Rab 15 protein by immunofluorescence.It was found that over-expressing Rab 15 was co-located with Golgi,and was not co-located with endosomes or lysosomes.After detecting the protein expression of Rab 15 in mammary tumor cells,we found that the protein expression of Rab 15 was lower in highly invasive breast cancer cells.So we prefers to explore influence of Rab 15 overexpression in high-invasive cell MDA-MB-231.By drawing the growth curve,MTT method,crystal violet staining,we found Rab15 overexpressing inhibited highly invasive breast cancer cell growth.We observed that Rab 15 overexpressing in MDA-MB-231 cells inhibited the invasion of highly invasive breast cancer cells by scratch test and transwell chamber.For further study,we used immunoblotting to detect some proteins in relation to the growth and migration.We found in highly invasive breast cancer,the expression of EGFR and MMP2 decreased when Rab 15 overexpressed.EGFR is associated with tumor cell proliferation,inhibition of apoptosis and tumor invasion and metastasis.MMP2 is capable of degrading the basement membrane.We hypothesized that overexpression of Rab 15 would inhibit cell proliferation and migration by effecting EGFR-associated downstream signaling,and degradation of MMP2 would inhibit cell migration and invasion.This work lays a good foundation for further studying the biological function of Rab15.