* Doxorubicin induces cell death in breast cancer cells regardless of Survivin and XIAP expression levels.
- Breast cancer is the leading cause of deaths in women around the world. Resistance to therapy is the main cause of treatment failure and still little is known about predictive biomarkers for response to systemic therapy. Increasing evidence show that Survivin and XIAP overexpression is closely associated with chemoresistance and poor prognosis in breast cancer. However, their impact on resistance to doxorubicin (dox), a chemotherapeutic agent widely used to treat breast cancer, is poorly understood. Here, we demonstrated that dox inhibited cell viability and induced DNA fragmentation and activation of caspases-3, -7 and -9 in the breast cancer-derived cell lines MCF7 and MDA-MB-231, regardless of different p53 status. Dox exposure resulted in reduction of Survivin and XIAP mRNA and protein levels. However, when we transfected cells with a Survivin-encoding plasmid, we did not observe a cell death-resistant phenotype. XIAP and Survivin silencing, either alone or in combination, had no effect on breast cancer cells sensitivity towards dox. Altogether, we demonstrated that breast cancer cells are sensitive to the chemotherapeutic agent dox irrespective of Survivin and XIAP expression levels. Also, our findings suggest that dox-mediated modulation of Survivin and XIAP might sensitize cells to taxanes when used in a sequential regimen.
Overview of noun level
The noun level has 8 senses (first 6 from tagged texts)
1. (69) degree, grade, level -- (a position on a scale of intensity or amount or quality; "a
moderate grade of intelligence"; "a high level of care is required"; "it is all a matter of degree")
2. (22) grade, level, tier -- (a relative position or degree of value in a graded group; "lumber of
the highest grade")
3. (15) degree, level, stage, point -- (a specific identifiable position in a continuum or series or
especially in a process; "a remarkable degree of frankness"; "at what stage are the social
sciences?")
4. (5) level -- (height above ground; "the water reached ankle level"; "the pictures were at the
same level")
5. (1) level, spirit level -- (indicator that establishes the horizontal when a bubble is centered
in a tube of liquid)
6. (1) horizontal surface, level -- (a flat surface at right angles to a plumb line; "park the car
on the level")
7. level, layer, stratum -- (an abstract place usually conceived as having depth; "a good actor
communicates on several levels"; "a simile has at least two layers of meaning"; "the mind functions
on many strata simultaneously")
8. floor, level, storey, story -- (a structure consisting of a room or set of rooms at a single
position along a vertical scale; "what level is the office on?")
Overview of verb level
The verb level has 6 senses (first 3 from tagged texts)
1. (4) level -- (aim at; "level criticism or charges at somebody")
2. (1) level, raze, rase, dismantle, tear down, take down, pull down -- (tear down so as to make
flat with the ground; "The building was levelled")
3. (1) flush, level, even out, even -- (make level or straight; "level the ground")
4. charge, level, point -- (direct into a position for use; "point a gun"; "He charged his weapon at
me")
5. level -- (talk frankly with; lay it on the line; "I have to level with you")
6. level, level off -- (become level or even; "The ground levelled off")
--- WordNet end ---