A highly selective and potent CXCR4 antagonist for hepatocellular carcinoma treatment.

The CXC chemokine receptor type 4 (CXCR4) receptor and its ligand, CXCL12, are overexpressed in various cancers and mediate tumor progression and hypoxia-mediated resistance to cancer therapy. While CXCR4 antagonists have potential anticancer effects when combined with conventional anticancer drugs, their poor potency against CXCL12/CXCR4 downstream signaling pathways and systemic toxicity had precluded clinical application. Herein, BPRCX807, known as a safe, selective, and potent CXCR4 antagonist, has been designed and experimentally realized. In in vitro and in vivo hepatocellular carcinoma mouse models it can significantly suppress primary tumor growth, prevent distant metastasis/cell migration, reduce angiogenesis, and normalize the immunosuppressive tumor microenvironment by reducing tumor-associated macrophages (TAMs) infiltration, reprogramming TAMs toward an immunostimulatory phenotype and promoting cytotoxic T cell infiltration into tumor. Although BPRCX807 treatment alone prolongs overall survival as effectively as both marketed sorafenib and anti-PD-1, it could synergize with either of them in combination therapy to further extend life expectancy and suppress distant metastasis more significantly.

Linker Optimization and Therapeutic Evaluation of Phosphatidylserine-Targeting Zinc Dipicolylamine-based Drug Conjugates.

We report that compound 13, a novel phosphatidylserine-targeting zinc(II) dipicolylamine drug conjugate, readily triggers a positive feedback therapeutic loop through the in situ generation of phosphatidylserine in the tumor microenvironment. Linker modifications, pharmacokinetics profiling, in vivo antitumor studies, and micro-Western array of treated-tumor tissues were employed to show that this class of conjugates induced regeneration of apoptotic signals, which facilitated subsequent recruitment of the circulating conjugates through the zinc(II) dipicolylamine-phosphatidylserine association and resulted in compounding antitumor efficacy. Compared to the marketed compound 17, compound 13 not only induced regressions in colorectal and pancreatic tumor models, it also exhibited at least 5-fold enhancement in antitumor efficacy with only 40% of the drug employed during treatment, culminating in a >12.5-fold increase in therapeutic potential. Our study discloses a chemically distinct apoptosis-targeting theranostic, with built-in complementary functional moieties between the targeting module and the drug mechanism to expand the arsenal of antitumor therapy.

Synthesis and evaluation of 3-ylideneoxindole acetamides as potent anticancer agents.

Indirubin, an active component in the traditional Chinese medicine formula Danggui Longhui Wan, shows promising anticancer effects. Meisoindigo is an analog derived from indirubin, which is less toxic and appears to be even more potent against cancer. In considering meisoindigo as a structural template for the development of new drugs, we designed and synthesized a series of 3-ylideneoxindole acetamides as novel anticancer agents. The acetamides were then evaluated for in vitro and in vivo anticancer activities. The 3-ylideneoxindole acetamides were found to have better anticancer activity than was indirubin-3'-oxime in several cancer cell lines and also displayed a spectrum of activity similar to that of the drug candidate roscovitine, a CDK inhibitor. Among the 3-ylideneoxindole acetamides, compound 10 showed particularly good efficacy. Cell cycle analysis further revealed that compound 10 arrested cells in the G1 phase and caused an increase in the sub-G1 population, indicating that the apoptosis pathway had been induced. In addition, exposure of cells to compound 10 led to the upregulation of the cell-cycle regulator cyclin D1, which was sustained at a high level. In contrast, the same compound induced a short-term elevation in the level of cyclin E, which was followed by a rapid decrease and the attenuation of Rb phosphorylation. Furthermore, a docking model suggests that compound 10 binds to the active site of CDK4. In testing the therapeutic potency of compound 10 on CT26-xenografted BALB/c mice, a significant reduction in tumor size comparable to that of cisplatin was found when administrated via the i.p. route. The mice presented no loss of body weight, indicating that this compound possesses low toxicity. In the future, we are planning in vivo investigations of these new active anticancer agents to better elucidate active mechanisms at the cellular level and thus benefit the development of anticancer therapies.