6-Methoxyethylamino-numonafide inhibits hepatocellular carcinoma xenograft growth as a single agent and in combination with sorafenib.

Hepatocellular carcinoma (HCC) is the third leading form of cancer worldwide, and its incidence is increasing rapidly in the United States, tripling over the past 3 decades. The current chemotherapeutic strategies against localized and metastatic HCC are ineffective. Here we report that 6-methoxyethylamino-numonafide (MEAN) is a potent growth inhibitor of murine xenografts of 2 human HCC cell lines. At the same dose and with the same treatment strategies, MEAN was more efficacious in inhibiting tumor growth in mice than sorafenib, the only approved drug for HCC. Treatment by MEAN at an effective dose for 6 wk was well tolerated by animals. Combined therapy using both sorafenib and MEAN enhanced tumor growth inhibition over monotherapy with either agent. Additional experiments revealed that MEAN inhibited tumor growth through mechanisms distinct from those of either its parent compound, amonafide, or sorafenib. MEAN suppressed C-MYC expression and increased expression of several tumor suppressor genes, including Src homology region 2 domain-containing phosphatase-1 (SHP-1) and TXNIP (thioredoxin-interacting protein). As an encouraging feature for envisioned clinical application, the IC50 of MEAN was not significantly changed in several drug-resistant cell lines with activated P-glycoprotein drug efflux pumps compared to drug-sensitive parent cells, demonstrating the ability of MEAN to be effective in cells resistant to existing chemotherapy regimens. MEAN is a promising candidate for clinical development as a single-agent therapy or in combination with sorafenib for the management of HCC.-Liu, Y., Lou, G., Norton, J. T., Wang, C., Kandela, I., Tang, S., Shank, N. I., Gupta, P., Huang, M., Avram, M. J., Green, R., Mazar, A., Appella, D., Chen, Z., Huang, S. 6-Methoxyethylamino-numonafide inhibits hepatocellular carcinoma xenograft growth as a single agent and in combination with sorafenib.

Additive melanoma suppression with intralesional phospholipid-conjugated TLR7 agonists and systemic IL-2.

There remains a compelling need for the development of treatments for unresectable melanoma. Agents that stimulate the innate immune response could provide advantages for cell-based therapies. However, there are conflicting reports concerning whether toll-like receptor (TLR) signaling controls tumor growth. The objective of this study was to evaluate the effect of intralesional administration of a TLR7 agonist in melanoma therapy. B16cOVA melanoma was implanted to TLR7 mice to evaluate the roles of stromal TLR7 on melanoma growth. To capitalize on the potential deleterious effects of TLR7 stimulation on the tumor growth, we injected melanoma tumor nodules with a newly developed and potent TLR7 agonist. B16 melanoma nodules expanded more rapidly in TLR7-deficient and MyD88 mice compared with TLR9 and wild type mice. Repeated injections with low doses of unconjugated TLR7 agonist were more effective at attenuating nodule size than a single high dose injection. To improve the efficacy we conjugated the agonist to phospholipid or phospholipids-polyethylene glycol, which retained TLR7 specificity. The phospholipid conjugate was indeed more effective in reducing lesion size. Furthermore, intralesional administration of the phospholipid TLR7 agonist conjugate enhanced the antimelanoma effects of systemic treatment with interleukin (IL)-2 and prolonged the survival of mice compared with IL-2 alone. Our study showed that: (1) TLR7/MyD88 signaling in the stroma is involved in melanoma growth; and (2) intralesional administration of a TLR7 agonist reduces the growth of melanoma nodules and enhances the antimelanoma effects of IL-2.