we looked at HepG2 expression in chips. When HepG2 grow as nodule (as real "tumor" if you like) CXCL1 expression was increased compared to HepG2 grown as cells - chip result only, we did not check (confirm) by PCR (yet).

regards, Harald

Hi, thank you for the answers,

We had the data (ELISA, Luminex, qPCR) from mouse tumor cell line and HCC tissue. That was a reason, why I asked-if the same occures in humans.

we observed in HepG2 a nice increase in expression of CXCL1 (just a by product, we were not looking for CXCL) when the cells were grown as “tumor” aka nodule as compared to the same cells grown in monolayer. I have no idea what this means for tumor growth. Did you see something similar with your mouse cells? When you compare your cell lines with HCC tissue samples? It would be interesting if this occurs in different species. Kind regards Harald

We did a detailed study on expression of CXCL cytokines in a murine model of colorectal liver metastasis and found that almost all the cytokines are overexpressed at the tumor part of the invasion front compared tothe inner parts of the tumor indicating the upon inflamation the cytokines are activated and have a role in tumor invasion and proliferation. Check our publication for more details "Down-regulation of CXCL1 inhibits tumor growth in colorectal liver metastasis."

Dear Harald,

Thank you for the interesting note. We performed gene expression analysis of liver tissues derived from naive mice and mice with chemically induced HCC. The expression of CXCL1 was upregulated in the liver of tumor bearing mice.

Although we did not succeed to isolate HCC cell line from the tumor nodules, therefore the question, if transformed hepatocytes secrete CXCL1 still remains unanswered.

Moreover, when I checked one murine HCC cell line and it was not expressing CXCl1 neither in monolayer nor after in vivo (subcutaneous) growth.

So maybe CXCL1 is not derived from transformed hepatocytes, but from hepatic non-parenchymal cells, after interaction with tumor cells..

Dear Obul,

Thank you for the information. It sounds very interesting. I will check the paper.

Dear Tamara, t I am surprised that your in vivo tumors showed no expression... we had chip results only - no confirmation by PCR - as we were not looking for CXCLs. I will go back to the data and see how strong the signal was. The increase in tumors (compared to monolayer) wasquite constant in 4 experiments, but possibly on a low level... Will check tomorrow. Has a possible role of CXCL1 in HCC been discussed before? I am quite ignorant there - will have to see what pubmed knows....

Interesting - even looks like cxcl1 expression can be modulated by kinase inhibitors...see Tang et al.. Hepatology. 2012 Mar;55(3):807-20. CD133(+) liver tumor-initiating cells promote tumor angiogenesis, growth, and self-renewal through neurotensin/interleukin-8/CXCL1 signaling.