I know that CL2 is derived from LNCaP and they vary in their metastatic potential. But can we call them isogenic meaning genetically same? Thank you all in advance.
CL1 is the androgen-independent outgrowth from LNCaP that has been cultured in androgen-free medium. CL2 is CL1 itself but cultured in the presence of androgen.
For matters of cancer research, CL2 and CL1 would be isogenic on the face of it, and isogenic with LNCaP. e.g see here for colon cancer derivatives of DLD-1
Article Torrance, C., Agrawal, V., Vogelstein, B. & Kinzler, K. Use ...
The term isogenic at the cellular level is a little bit of a stretch because all cells derived from a given patient are by definition isogenic. But when used as it is used for cells it implies that all cells have a very similar genetic background to other cells in a population, and most often at the mutational/copy number level also. This latter point is important, since the clarification is made " isogenic, except for mutations in genes A, B or C".
This of course clearly assumes that LNCaP is itself a homogeneous population of cells, and no cell in the population is different from the other genetically. Single cell sequencing at the genomic level would be required to confirm that. If, however, one treats LNCaP cells as homogeneous like during cell culture, CL1 and CL2 are isogenic derivatives of LNCaP.