Recently, I implanted breast MDA-MB-231 tumor cells in NSG mice. Surprisingly, some mice showed ulceration in their tumors at tumor size around 200-300 mm3 much below the humane endpoint. I never observed such problem with other tumor xenografts I did in the past such as small cell lung cancer H146 and ALL MOLT-4 xenografts. Although I used CB-17 SCID mice for those studies. I am wondering whether this is common with this cell line or mice strain or the combination of both? Any suggestions or personal experience will be appreciated.
Thanks
Yes. We also found large tumors with MDA-MB-231 in transplanted SCID mice. This is the property of this cell line, and need to inject less than a million cells to form good tumors.
Poor vascularization leading to cell necrosis, apoptosis from too dense cell population? VEGF, EGFR issues?
Aggressive cell lines like MDA-MB-231 can also lead to ulceration by invading into dermis and secreting MMP's. Interaction of inflammatory site with the NK and monocytes in the NSG will lead to ulceration.
We use NOD/SCID mice in our MDA-MB-231 xenografts (see http://altogenlabs.com/xenograft-models/breast-cancer-xenograft/mda-mb-231-xenograft-model/) and we haven't had such issues. There can be reasons ranging from an immune response to the injection protocol, so it's difficult to really pinpoint a cause.
