Project description:Previously, we designed pharmacologically optimized inhibitor RHOA, a major signaling hub in gastric cancer (GC), the fourth most common cause of death in the world. Here, based on that previous work, we perform the lead optimization and design new RHOA inhibitors for greater anti-GC potency. Two of these compounds, JK-206 and -312 inhibit cell viability and migration of GC cell lines. Furthermore, through our transcriptomics analysis of JK-206 treatment in GC cells, we revealed that pharmacologic inhibition of RHOA was associated with inhibition of mitogenic pathway, including BIRC5. Thus, RHOA→BIRC5 can be regarded as a new therapeutic strategy in GC, possibly regulating proliferation and migration in oncogenic mechanisms.
Project description:Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive lymphoid tumor derived from malignant transformation of T follicular helper (Tfh) cells. Genetically, AITL is characterized by loss of function mutations in the Ten-Eleven Translocation 2 (TET2) epigenetic tumor suppressor and a highly recurrent mutation (p.Gly17Val, G17V) in the RHOA small GTPase gene Moreover, RHOA G17V expression in Tet2 deficient hematopoietic progenitors resulted in the specific development of lymphoid tumors resembling human AITL. Notably, inhibition of ICOS signaling impaired the growth of RHOA G17V-induced mouse lymphomas in vivo, thus providing a potential new rational approach for the treatment of AITL.
Project description:RHOA is a recurrently mutated gene in diffuse-type gastric cancer, whose molecular influence in gastric cancer has not been well uncovered. We aimed to clarify the contribution of RHOA to pro-oncogenesis to improve the understanding of the role of RHOA as a therapeutic target. We performed microarray analysis after RHOA knockdown for HGC-27, AGS, CCK-81, and SW948.
Project description:RNA is emerging as a valuable target for the development of novel therapeutic agents. The rational design of RNA-targeting small molecules, however, has been hampered by the relative lack of methods for the analysis of small molecule-RNA interactions. Here we present our efforts to develop such a platform using photoaffinity labeling. This technique, termed Photoaffinity Evaluation of RNA Ligation-Sequencing (PEARL-seq), enables the rapid identification of small molecule binding locations within their RNA targets and can provide information on ligand selectivity across multiple different RNAs. These data, when supplemented with small molecule SAR data and RNA probing data enables the construction of a computational model of the RNA-ligand structure, thereby enabling the rational design of novel RNA-targeted ligands.
Project description:Starting from the structure of the human ASF1-histone complex, we developed a rational design strategy combining epitope tethering and optimization of interface contacts to identify a potent peptide inhibitor with a dissociation constant of 3 nM. LC-MS/MS was used to identify in vivo targets of the most prominent peptide inhibitor.
Project description:Rho family small GTPases serve as molecular switches in the regulation of diverse cellular functions including actin cytoskeleton remodeling, cell migration, gene transcription, and cell proliferation. Importantly, Rho overexpression is frequently seen in many carcinomas. However, published studies have almost invariably utilized immortal or tumorigenic cell lines to study Rho GTPase functions and there are no studies on the potential of Rho small GTPase to overcome senescence checkpoints and induce preneoplastic transformation of human mammary epithelial cells (hMECs). We found that ectopic expression of wild-type RhoA as well as a constitutively-active RhoA mutant (G14V) in primary hMEC strains led to their immortalization and preneoplastic transformation. Significantly, RhoA-T37A mutant, known to be incapable of interacting with many well known Rho-effectors ,was also capable of immortalizing hMECs.Our results demonstrate that RhoA can induce the preneoplastic transformation of hMECs by altering multiple pathways linked cellular transformation and breast cancer. Through microarray analysis, we want to identify genes and pathways linked to RhoA induced hMECs immortalization. Experiment Overall Design: 4 samples, in triplicate analyses per sample.
Project description:Previously, we identified Ras homologous A (RHOA) as a major signalling hub in gastric cancer (GC), the third-most common cause of cancer death in the world, prompting us to rationally design an efficacious inhibitor of this oncogenic GTPase. Here, based on that previous work, we extend those computational analyses, and in silico modeling approaches, to further pharmacologically optimize anti-RHOA hydrazide derivatives for greater anti-GC potency. Two of these, JK-136 and JK-139, potently inhibited cell viability and migration/invasion of GC cell lines, and mouse xenografts, diversely expressing RHOA. Moreover, JK-136’s binding affinity for RHOA was >140-fold greater than Rhosin, a nonclinical RHOA inhibitor. Network analysis of JK-136/139-associated transcriptomes showed different functional contexts, compared to those following treatment with Rhosin. We strongly assert that identifying and targeting oncogenic signalling hubs, such as RHOA, represents an emerging strategy for the design, characterization, and translation of new antineoplastics, against gastric and other cancers.