CT26.WT-mNIS is a monoclonal population of mouse colorectal carcinoma CT26.WT cell line (ATCC® CRL-2638™). To achieve stable reporter expression in the monoclonal population, parental CT26.WT cells were transduced with LV-mNIS (LV008) and expanded from a single cell. LV-mNIS encodes the mouse sodium iodide symporter (mNIS) cDNA under the spleen focus-forming virus (SFFV) promoter.

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This cell line has been tested for mycoplasma contamination and is certified mycoplasma free.

The parental CT26.WT cell line has been authenticated and certified free of interspecies cross contamination by short tandem repeat (STR) profiling with 9 STR loci.

In Vivo Imaging

Immunocompetent syngeneic Balb/c mice were injected intravenously with 5 x 10⁵  CT26.WT-mNIS (CL119) cells (A) or intraperitoneally with 1 x 10⁶ cells (B). SPECT/CT imaging using [^99mTc]-pertechnetate was performed after 24 (A) or 13 (B) days.

Morphology

Low and high density cell morphology (200x)

NIS Expression

 Cells were incubated with I-125 for one in the presence or absence of KClO₄, an inhibitor of iodine uptake. Radioiodine concentrated within the cells was measured with a gamma counter.

Complete Growth Medium: DMEM supplemented with 10% FBS and 1X Penicillin/Streptomycin.

These cells should be grown in the indicated medium and passaged when they reach confluency. For routine passaging, cells are recommended to be split at a 1:10 ratio every 3-4 days.

CT26.WT cells easily detach from tissue culture surfaces. Coating culture plates with poly-D-Lysine prior to use is recommended for applications involving frequent washes, culture media changes, or rocking.

These cells are suitable for in vitro and in vivo experimentation. CT26.WT cells form tumors and pulmonary metastases post implantation into syngenic Balb/c mice.¹ The NIS transgene facilitates high resolution, 3D SPECT/PET imaging of implanted cells. NIS is not immunogenic and is therefore suitable for longitudinal imaging studies in a syngenic model.

The cells can be amplified in vitro and used to generate additional frozen stocks. Cryopreservation of low passage stocks is recommended. Frozen stocks should be preserved in a designated cryopreservation medium.

These cells were generated via lentiviral vector transduction. The lentiviral vector used for transduction was a self-inactivating (SIN) vector in which the viral enhancer and promoter have been deleted. Transcription inactivation of the LTR in the SIN provirus increases biosafety by preventing mobilization by replication competent viruses and enables regulated expression of the genes from the internal promoters without cis-acting effects of the LTR². Nevertheless, all work with these cells should be performed under biosafety-level 2 (BSL2) conditions by trained personnel. Institutional requirements may permit handling of these cells under BSL1 conditions if certain criteria are met.

References:
¹Wang et al. J Immunol. 1995. 154:4685-4692.
²Miyoshi et al. J Virol 1998. 72:8150-8157.