02347nas a2200253   4500008004100000245009500041210006900136260004200205300001300247490000600260520152900266100002701795700002101822700002901843700001601872700003001888700002001918700001701938700001801955700002501973700002001998700002202018856005302040       2013                        eng d00aMammosphere Formation in Breast Carcinoma Cell Lines Depends upon Expression of E-cadherin0 aMammosphere Formation in Breast Carcinoma Cell Lines Depends upo  bPublic Library of Sciencec2013/10/04  ae77281 -0 v83 a<p>Tumors are heterogeneous at the cellular level where the ability to maintain tumor growth resides in discrete cell populations. Floating sphere-forming assays are broadly used to test stem cell activity in tissues, tumors and cell lines. Spheroids are originated from a small population of cells with stem cell features able to grow in suspension culture and behaving as tumorigenic in mice. We tested the ability of eleven common breast cancer cell lines representing the major breast cancer subtypes to grow as mammospheres, measuring the ability to maintain cell viability upon serial non-adherent passage. Only MCF7, T47D, BT474, MDA-MB-436 and JIMT1 were successfully propagated as long-term mammosphere cultures, measured as the increase in the number of viable cells upon serial non-adherent passages. Other cell lines tested (SKBR3, MDA-MB-231, MDA-MB-468 and MDA-MB-435) formed cell clumps that can be disaggregated mechanically, but cell viability drops dramatically on their second passage. HCC1937 and HCC1569 cells formed typical mammospheres, although they could not be propagated as long-term mammosphere cultures. All the sphere forming lines but MDA-MB-436 express E-cadherin on their surface. Knock down of E-cadherin expression in MCF-7 cells abrogated its ability to grow as mammospheres, while re-expression of E-cadherin in SKBR3 cells allow them to form mammospheres. Therefore, the mammosphere assay is suitable to reveal stem like features in breast cancer cell lines that express E-cadherin.</p>1 aIglesias, Juan, Manuel1 aBeloqui, Izaskun1 aGarcia-Garcia, Francisco1 aLeis, Olatz1 aVazquez-Martin, Alejandro1 aEguiara, Arrate1 aCufi, Silvia1 aPavon, Andres1 aMenendez, Javier, A.1 aDopazo, Joaquin1 aMartin, Angel, G.  uhttp://dx.doi.org/10.1371%2Fjournal.pone.0077281