m6A modification: recent advances, anticancer targeted drug discovery and beyond.

Abnormal N6-methyladenosine (m6A) modification is closely associated with the occurrence, development, progression and prognosis of cancer, and aberrant m6A regulators have been identified as novel anticancer drug targets. Both traditional medicine-related approaches and modern drug discovery platforms have been used in an attempt to develop m6A-targeted drugs. Here, we provide an update of the latest findings on m6A modification and the critical roles of m6A modification in cancer progression, and we summarize rational sources for the discovery of m6A-targeted anticancer agents from traditional medicines and computer-based chemosynthetic compounds. This review highlights the potential agents targeting m6A modification for cancer treatment and proposes the advantage of artificial intelligence (AI) in the discovery of m6A-targeting anticancer drugs. Three stages of m6A-targeting anticancer drug discovery: traditional medicine-based natural products, modern chemical modification or synthesis, and artificial intelligence (AI)-assisted approaches for the future.

Synthesis and biological evaluation of marine natural product, Cryptoechinuline D derivatives as novel antiangiogenic agents.

Tumor angiogenesis is an important biological process involved in the proliferation and migration of endothelial cells, regulated by Ang/Tie-2 signaling pathways, which is essential for tumor growth and metastasis. Therefore, blocking Ang/Tie-2 signaling pathways is a promising anti-angiogenic strategy for tumor treatment. 2,5-Diketopiperazines (DKPs) are a kind of bioactive compounds derived from marine fungi and they present a wide spectrum of pharmacological properties, particularly in the field of cancer treatment. Herein, a DKP marine natural product, Cryptoechinuline D (Cry D) was applied to structural modification and twelve derivatives were synthesized. Among which, compound 5 showed significant inhibitory activity against HUVECs with an IC50 value of 12.6 µmol/L, which weakened the proliferation, migration and invasion of HUVECs by inhibiting the Ang2/Tie-2 signaling pathway. The results of these evaluations indicated that compound 5 might be a promising anti-angiogeneic agent and worth further optimization and development for cancer therapy.

Erianin inhibits the growth and metastasis through autophagy-dependent ferroptosis in KRASG13D colorectal cancer.

Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide. Approximately 40% of CRC patients are KRAS sequence variation, including KRAS G13D mutation (KRASG13D) CRC patients, accounting for approximately 8% of all KRAS mutations in CRC patients and showing little benefit from anti-EGFR therapy. Therefore, there is an urgent need for new and effective anticancer agents in patients with KRASG13D CRC. Here, we identified a natural product, erianin, that directly interacted with purified recombinant human KRASG13D with a Kd of 1.1163 µM, which also significantly improve the thermal stability of KRASG13D. The cell viability assay showed that KRASG13D cells were more sensitive to erianin than KRASWT or KRASG12V cells. In vitro, results showed that erianin suppressed the migration, invasion and epithelial-mesenchymal transition (EMT) of KRASG13D CRC cells. Furthermore, erianin induced ferroptosis, as evidenced by the accumulation of Fe2+ and reactive oxygen species (ROS), lipid peroxidation, and changes in the mitochondrial morphology of KRASG13D CRC cells. Interestingly, we also found that erianin-induced ferroptosis was accompanied by autophagy. Moreover, the occurrence of erianin-induced ferroptosis is reversed by autophagy inhibitors (NH4Cl and Bafilomycin A1) and ATG5 knockdown, suggesting that erianin-induced ferroptosis is autophagy-dependent. In addition, we evaluated the inhibition of tumor growth and metastasis by erianin in vivo using a subcutaneous tumor model and a spleen-liver metastasis model, respectively. Collectively, these data provide novel insights into the anticancer activity of erianin, which is valuable for the further discussion and investigation of the use of erianin in clinical anticancer chemotherapy for KRASG13D CRC.

Periplocin inhibits hepatocellular carcinoma progression and reduces the recruitment of MDSCs through AKT/NF-κB pathway.

AIMS: We aimed to evaluate the effect of periplocin on inhibiting hepatocellular carcinoma (HCC) and further determine its mechanisms. MAIN METHODS: Cytotoxic activity of periplocin against HCC cells was tested by CCK-8 and colony formation assays. The antitumor effects of periplocin were evaluated in human HCC SK-HEP-1 xenograft and murine HCC Hepa 1-6 allograft mouse models. Flow cytometry was used to measure cell cycle distribution, apopotosis, and the number of myeloid-derived suppressor cells (MDSCs). Hoechst 33258 dye was applied to observe the nuclear morphology. Network pharmacology was performed to predict possible signaling pathways. Drug affinity responsive target stability assay (DARTS) was used to evaluate AKT binding of periplocin. Western blotting, immunohistochemistry, and immunofluorescence were used to examine the protein expression levels. KEY FINDING: Periplocin inhibited cell viability with IC50 values from 50 nM to 300 nM in human HCC cells. Periplocin disrupted cell cycle distribution and promoted cell apoptosis. Moreover, AKT was predicted as the target of periplocin by network pharmacology, which was confirmed by that AKT/NF-κB signaling was inhibited in periplocin-treated HCC cells. Periplocin also inhibited the expression of CXCL1 and CXCL3, leading to decreased accumulation of MDSCs in HCC tumors. SIGNIFICANCE: These findings reveal the function of periplocin in inhibiting HCC progression by G2/M arrest, apoptosis and suppression of MDSCs accumulation through blockade of the AKT/NF-κB pathway. Our study further suggests that periplocin has the potential to be developed as an effective therapeutic agent for HCC.