Added new citations linking DPP-4 inhibition with the promotion of metastatic cancers for lung cancer, prostate cancer, ovarian cancer, melanoma, and neuroblastoma.
Added reply from a much-published DPP-4 tumor gene researcher confirming that the impact of Januvia on DPP-4 is of grave concern, especially since it has not been the target of any investigation.
The researcher who I queried about the importance of this research had this reply for me via email:
I agree that use of DPPIV inhibitors to treat diabetes patients needs further studies. Inhibiting DPPIV function in general(according to ours and others research) may not be a great idea. I believe that decrease or loss of DPPIV may be associated with cancer initiation or progression.
We have shown that loss of DPPIV is indeed associated with melanoma, prostate and lung cancers. Importantly our work has shown that restoring DPPIV can suppress the tumor growth. I have not conducted any detailed studies with DPPIV inhibitors including Januvia, in particular. DPPIV has multiple functions. It is not known if Januvia blocks all of its functions. This warrants more studies with this drug.