CK2, a protein serine/threonine kinase, promotes cell proliferation and suppresses cell death. This essential-for-survival signal demonstrates elevated expression and activity in all cancers examined, and is considered an attractive target for cancer therapy. Here, we present data on the efficacy of a tenfibgen (TBG) coated nanocapsule which delivers its cargo of siRNA (siCK2) or single stranded RNA/ DNA oligomers (RNAi-CK2) simultaneously targeting CK2α and α' catalytic subunits. Intravenous administration of TBG-siCK2 or TBG-RNAi-CK2 resulted in significant xenograft tumor reduction at low doses in PC3-LN4 and 22Rv1 models of prostate cancer. Malignant cell uptake and specificity in vivo was verified by FACS analysis and immunofluorescent detection of nanocapsules and PCR detection of released oligomers. Dose response was concordant with CK2αα' RNA transcript levels and the tumors demonstrated changes in CK2 protein and in markers of proliferation and cell death. Therapeutic response corresponded to expression levels for argonaute and GW proteins, which function in oligomer processing and translational repression. No toxicity was detected in non-tumor tissues or by serum chemistry. Tumor specific delivery of anti-CK2 RNAi via the TBG nanoencapsulation technology warrants further consideration of translational potential.
Bibliographical noteFunding Information:
TEM images were acquired by Richard An (IHC World, Elliot City, MD). This work was supported by Merit Review research funds BX001731 awarded by the Department of Veterans Affairs (KA); research grant CA150182 awarded by the National Cancer Institute, NIH, Department of Health and Human Services (KA); research grants CA158730 and DK067436 awarded by NCI and NIDDK, respectively, NIH, Department of Health and Human Services (BTK); and research grants HHS-N261-2008-00027/N42CM-2008-00027C, CA99366, and CA119556 awarded by National Cancer Institute, NIH, Department of Health and Human Services (GMU).