Figure 8.

CLCN4 stimulates experimental metastases and is elevated in expression in metastases to the liver/lymph nodes. (A) Pooled RKO clones overexpressing full-length CLCN4 cDNA (RKO-CLCN4) or the empty vector (RKO-vector) were injected (10⁶ cells) into the spleen of groups of 10 nude mice. After 6 weeks, the mice were killed and liver tissues were examined macroscopically for metastatic tumour nodules or subjected to RT–PCR for CLCN4. (B) RNA extracted from a series of primary colon tumours and colon cancer metastases to the liver was subjected to RT–PCR for CLCN4 expression as per Figure 7. (C) Query of the Gene Expression Omnibus database (http://www.ncbi.nlm.nih.gov/projects/geo/) showing increased CLCN4 expression in colon cancer metastases to the lymph nodes compared with synchronous primary tumours. Squares within each bar represent the percentile rank of the CLCN4 transcript for all transcripts within the sample (right axis). Left axis shows the relative scale for the measured level of abundance of the CLCN4 transcript (arbitrary values). The faded bar represents an absent detection call (Affymetrix, Santa Clara, CA, USA).