DHPS-Mediated Hypusination Regulates METTL3 Self-m6A-Methylation Modification to Promote Melanoma Proliferation and the Development of Novel Inhibitors.

Discovering new treatments for melanoma will benefit human health. The mechanism by which deoxyhypusine synthase (DHPS) promotes melanoma development remains elucidated. Multi-omics studies have revealed that DHPS regulates m6A modification and maintains mRNA stability in melanoma cells. Mechanistically, DHPS activates the hypusination of eukaryotic translation initiation factor 5A (eIF5A) to assist METTL3 localizing on its mRNA for m6A modification, then promoting METTL3 expression. Structure-based design, synthesis, and activity screening yielded the hit compound GL-1 as a DHPS inhibitor. Notably, GL-1 directly inhibits DHPS binding to eIF5A, whereas GC-7 cannot. Based on the clarification of the mode of action of GL-1 on DHPS, it is found that GL-1 can promote the accumulation of intracellular Cu2+ to induce apoptosis, and antibody microarray analysis shows that GL-1 inhibits the expression of several cytokines. GL-1 shows promising antitumor activity with good bioavailability in a xenograft tumor model. These findings clarify the molecular mechanisms by which DHPS regulates melanoma proliferation and demonstrate the potential of GL-1 for clinical melanoma therapy.

Hypusination-induced DHPS/eIF5A pathway as a new therapeutic strategy for human diseases: A mechanistic review and structural classification of DHPS inhibitors.

The discovery of new therapeutic strategies for diseases is essential for drug research. Deoxyhypusine synthase (DHPS) is a critical enzyme that modifies the conversion of the eukaryotic translation initiation factor 5A (eIF5A) precursor into physiologically active eIF5A (eIF5A-Hyp). Recent studies have revealed that the hypusine modifying of DHPS on eIF5A has an essential regulatory role in human diseases. The hypusination-induced DHPS/eIF5A pathway has been shown to play an essential role in various cancers, and it could regulate immune-related diseases, glucose metabolism-related diseases, neurological-related diseases, and aging. In addition, DHPS has a more defined substrate and a well-defined structure within the active pocket than eIF5A. More and more researchers are focusing on the prospect of advanced development of DHPS inhibitors. This review summarizes the regulatory mechanisms of the hypusination-induced DHPS/eIF5A pathway in a variety of diseases in addition to the inhibitors related to this pathway; it highlights and analyzes the structural features and mechanisms of action of DHPS inhibitors and expands the prospects of future drug development using DHPS as an anticancer target.

Discovery of novel thymidylate synthase (TS) inhibitors that influence cancer angiogenesis and metabolic reprogramming in NSCLC cells.

Based on previous work, further search for more effective and less damaging thymidylate synthase (TS) inhibitors was the focus of this study. After further optimization of the structure, in this study, a series of (E)-N-(2-benzyl hydrazine-1-carbonyl) phenyl-2,4-deoxy-1,2,3,4-tetrahydro pyrimidine-5-sulfonamide derivatives were synthesized and reported for the first time. All target compounds were screened by enzyme activity assay and cell viability inhibition assay. On the one hand, the hit compound DG1 could bind directly to TS proteins intracellularly and promote apoptosis in A549 and H1975 cells. Simultaneously, DG1 could inhibit cancer tissue proliferation more effectively than Pemetrexed (PTX) in the A549 xenograft mouse model. On the other hand, the inhibitory effect of DG1 on NSCLC angiogenesis was verified both in vivo and in vitro. In parallel, DG1 was further uncovered to inhibit the expression of CD26, ET-1, FGF-1, and EGF by angiogenic factor antibody microarray. Moreover, RNA-seq and PCR-array assays revealed that DG1 could inhibit NSCLC proliferation by affecting metabolic reprogramming. Collectively, these data demonstrated that DG1as a TS inhibitor could be promising in treating NSCLC angiogenesis, deserving further investigation.

Structural classification of MELK inhibitors and prospects for the treatment of tumor resistance: A review.

Maternal embryonic leucine zipper kinase (MELK), a member of the AMP-related serine-threonine kinase family, has been involved in regulating many cellular events, and aberrant MELK expression is associated with tumorigenesis and malignant progression in various cancers. More and more studies have found that MELK plays an essential regulatory role in tumor multidrug resistance or radio resistance. MELK inhibitors can also improve drug resistance caused by a gene mutation. These findings remind us that MELK could be a chemo- or radio-sensitizing target. However, it has also been found that most experiments on MELK rely on non-selective RNAi and small molecule reagents, which makes the results questionable, and thus the development of selective MELK inhibitors is still necessary. In this review, we summarized the identified regulatory pathways of MELK in tumor resistance and reclassified MELK inhibitors from a structural perspective. In addition, we discovered the glycosylation modification site of the MELK protein and discussed the possibility of continuing to develop small molecule inhibitors targeting the glycosylation modification site. These provide new strategies for developing selective MELK inhibitors and understanding the essential biological role of MELK in cancer.

Production of a fragment of glycoprotein G of herpes simplex virus type 2 and evaluation of its diagnostic potential

<p><b>INTRODUCTION</b>Herpes simplex virus type 2 (HSV-2) is the most common cause of genital herpes. Glycoprotein G (gG) is a prototype antigen for type-specific serodiagnosis distinguishing between HSV type 1 (HSV-1) and HSV-2 infections. As immunological diagnosis kits for accurate differentiation between HSV-1 and HSV-2 antibodies can be expensive, there is a need to develop a convenient, sensitive, specific and cost-effective serodiagnostic kit.</p><p><b>METHODS</b>We successfully expressed a fragment of gG comprising residues 321-580 of HSV-2 with histidine tag (gG(321-580His)) in a Bac-to-Bac baculovirus expression system, which had an antigenicity similar to its native counterpart. An indirect enzyme-linked immunosorbent assay (ELISA) was developed using gG(321-580His) as the diagnostic antigen and evaluated by comparison with a commercial HerpeSelect 2 ELISA immunoglobulin G kit as reference.</p><p><b>RESULTS</b>In testing 318 field serum samples, the diagnostic relative sensitivity and specificity of the developed gG(321-580His)-ELISA test in qualitative comparison with the commercial kit were 93.81% and 96.74%, respectively, and the accuracy was 94.65%.</p><p><b>CONCLUSION</b>The study indicates that gG(321-580His) has a high diagnostic potential for HSV-2 virus serodiagnosis in humans.</p>