RK-33

Pulmonary fibrosis is potentiated by a positive feedback loop involving the extracellular sialidase enzyme NEU3 causing release of active TGF-β1, and TGF-β1 upregulating NEU3 by increasing translation without affecting mRNA levels. In this report, we elucidate the TGF-β1 upregulation of translation mechanism. In human lung fibroblasts, TGF-β1 increased levels of proteins, including NEU3, by increasing translation of the encoding mRNAs without significantly affecting levels of these mRNAs...

OBJECTIVE: DDX3X is involved in various pathological processes such as infection, immunity and cell death. This study aimed to investigate the effect of RK-33, a specific inhibitor of DDX3X, on the progression of sepsis to persistent inflammation, immune suppression and catabolism syndrome(PICS). METHODS: The septic mice model was established using caecal ligation and perforation (CLP). The mice were randomly divided into four groups: sham group, sham + RK-33 group (20 mg/kg, intraperitoneal injection, once a day), CLP group and CLP + RK-33 group (20 mg/kg, intraperitoneal injection, once a day)...

Over-expression of DDX3X mRNA is associated with T cell loss in septic patients. This study aimed to investigate the molecular mechanism of DDX3X on T cell reduction in sepsis. The sepsis model was established using lipopolysaccharide stimulation in vitro and cecal ligation and puncture (CLP) surgery in vivo. Results showed that the expression of DDX3X was significantly upregulated in CD4+ T cells in sepsis. RK-33, the inhibitor of DDX3X, was found to dramatically increase CD4+ T cell counts and prolong the survival rate of mice with sepsis...

SARS-CoV-2, the virus behind the deadly COVID-19 pandemic, continues to spread globally even as vaccine strategies are proving effective in preventing hospitalizations and deaths. However, evolving variants of the virus appear to be more transmissive and vaccine efficacy toward them is waning. As a result, SARS-CoV-2 will continue to have a deadly impact on public health into the foreseeable future. One strategy to bypass the continuing problem of newer variants is to target host proteins required for viral replication...

The life-threatening adverse effects of doxorubicin (Dox) caused by its cardiotoxic properties limit its clinical application. DDX3X has been shown to participate in a variety of physiological processes, and it acts as a regulator of Wnt/β-catenin signaling. However, the role of DDX3X in Dox-induced cardiotoxicity (DIC) remains unclear. In this study, we found that DDX3X expression was significantly decreased in H9c2 cardiomyocytes treated with Dox. Ddx3x knockdown and RK-33 (DDX3X ATPase activity inhibitor) pretreatment exacerbated cardiomyocyte apoptosis and mitochondrial dysfunction induced by Dox treatment...

BACKGROUND: Secondary posttraumatic spinal kyphosis is a fixed deformity that has an asymptomatic presentation in most patients, but in some, persistent pain and disability can develop refractory to conservative treatment, which may result in the need for corrective surgery. Our aim was to analyze the modification of sagittal alignment and the variation in compensation mechanisms of spinal-pelvic segments before and after surgical correction in a group of patients with symptomatic posttraumatic kyphosis...

Stress granules (SGs) are non-membranous cytosolic protein-RNA aggregates that process mRNAs through stalled translation initiation in response to cellular stressors and in disease. DEAD-Box RNA helicase 3 (DDX3) is an active target of drug development for the treatment of viral infections, cancers, and neurodegenerative diseases. DDX3 plays a critical role in RNA metabolism, including SGs, but the role of DDX3 enzymatic activity in SG dynamics is not well understood. Here, we address this question by determining the effects of DDX3 inhibition on the dynamics of SG assembly and disassembly...

BACKGROUND & AIMS: It is not clear how pancreatic cancer stem cells (CSCs) are regulated, resulting in ineffective treatments for pancreatic cancer. PAF1, a RNA polymerase II-associated factor 1 complex (PAF1C) component, maintains pluripotency of stem cells, by unclear mechanisms, and is a marker of CSCs. We investigated mechanisms by which PAF1 maintains CSCs and contributes to development of pancreatic tumors. METHODS: Pancreatic cancer cell lines were engineered to knockdown PAF1 using inducible small hairpin RNAs...

Viral disease is one of the greatest burdens for human health worldwide, with an urgent need for efficacious antiviral strategies. While antiviral drugs are available, in many cases, they are prone to the development of drug resistance. A way to overcome drug resistance associated with common antiviral therapies is to develop antivirals targeting host cellular co-factors critical to viral replication, such as DEAD-box helicase 3 X-linked (DDX3X), which plays key roles in RNA metabolism and the antiviral response...

HIV-1 Associated Neurocognitive Disorder (HAND) is a common and clinically detrimental complication of HIV infection. Viral proteins, including Tat, released from infected cells, cause neuronal toxicity. Substance abuse in HIV-infected patients greatly influences the severity of neuronal damage. To repurpose small molecule inhibitors for anti-HAND therapy, we employed MOLIERE, an AI-based literature mining system that we developed. All human genes were analyzed and prioritized by MOLIERE to find previously unknown targets connected to HAND...

Medulloblastoma is the most common malignant tumor that arises from the cerebellum of the central nervous system. Clinically, medulloblastomas are treated by surgery, radiation, and chemotherapy, all of which result in toxicity and morbidity. Recent reports have identified that DDX3, a member of the RNA helicase family, is mutated in medulloblastoma. In this study, we demonstrate the role of DDX3 in driving medulloblastoma. With the use of a small molecule inhibitor of DDX3, RK-33, we could inhibit growth and promote cell death in two medulloblastoma cell lines, DAOY and UW228, with IC50 values of 2...

DDX3 is an RNA helicase with oncogenic properties. The small molecule inhibitor RK-33 is designed to fit into the ATP binding cleft of DDX3 and hereby block its activity. RK-33 has shown potent activity in preclinical cancer models. However, the mechanism behind the antineoplastic activity of RK-33 remains largely unknown. In this study we used a dual phosphoproteomic and single cell tracking approach to evaluate the effect of RK-33 on cancer cells. MDA-MB-435 cells were treated for 24 hours with RK-33 or vehicle control...

Objective: To compare the clinical outcome and health related quality of life(HRQoL)of patients with degenerative spinal deformity who underwent spino-pelvic fixation utilized second sacral alar-iliac(S(2)AI)with patient utilized traditional iliac screw(IS). Methods: Patients diagnosed as degenerative spinal deformity who underwent spino-pelvic fixation utilized either S(2)AI screw or Iliac screw at Department of Spine Surgery of Drum Tower hospital from January 2013 to January 2016 were retrospectively analyzed...

When crypt stem cells of the gastrointestinal tract become injured, the result is increased synthesis of pro-inflammatory cytokines and matrix metalloproteinases by their progeny - the colonic epithelium. Chronic inflammation of the gastrointestinal tract is a characteristic of inflammatory bowel disease, which includes Crohn's Disease and Ulcerative Colitis. In our ongoing investigation to decipher the characteristic functions of a RNA helicase gene, DDX3, we identified high DDX3 expression by immunohistochemistry of colon biopsy samples, which included chronic/mild Morbus Crohn, active Morbus Crohn, Chronic/mild Colitis Ulcerosa and active Colitis Ulcerosa in epithelium and stromal compartments...

DDX3 is a DEAD box RNA helicase with oncogenic properties. RK-33 is developed as a small-molecule inhibitor of DDX3 and showed potent radiosensitizing activity in preclinical tumor models. This study aimed to assess DDX3 as a target in breast cancer and to elucidate how RK-33 exerts its anti-neoplastic effects. High DDX3 expression was present in 35% of breast cancer patient samples and correlated with markers of aggressiveness and shorter survival. With a quantitative proteomics approach, we identified proteins involved in the mitochondrial translation and respiratory electron transport pathways to be significantly downregulated after RK-33 or DDX3 knockdown...

Triple-negative breast cancers have unfavorable outcomes due to their inherent aggressive behavior and lack of targeted therapies. Breast cancers occurring in BRCA1 mutation carriers are mostly triple-negative and harbor homologous recombination deficiency, sensitizing them to inhibition of a second DNA damage repair pathway by, e.g., PARP inhibitors. Unfortunately, resistance against PARP inhibitors in BRCA1-deficient cancers is common and sensitivity is limited in BRCA1-proficient breast cancers. RK-33, an inhibitor of the RNA helicase DDX3, was previously demonstrated to impede non-homologous end-joining repair of DNA breaks...

Despite advances in diagnosis and treatment, prostate cancer is the most prevalent cancer in males and the second highest cause of cancer-related mortality. We identified an RNA helicase gene, DDX3 (DDX3X), which is overexpressed in prostate cancers, and whose expression is directly correlated with high Gleason scores. Knockdown of DDX3 in the aggressive prostate cancer cell lines DU145 and 22Rv1 resulted in significantly reduced clonogenicity. To target DDX3, we rationally designed a small molecule, RK-33, which docks into the ATP-binding domain of DDX3...

RNA helicase DDX3 has oncogenic activity in breast and lung cancers and is required for translation of complex mRNA transcripts, including those encoding key cell-cycle regulatory proteins. We sought to determine the expression and function of DDX3 in sarcoma cells, and to investigate the antitumor activity of a novel small molecule DDX3 inhibitor, RK-33. Utilizing various sarcoma cell lines, xenografts and human tissue microarrays, we measured DDX3 expression at the mRNA and protein levels, and evaluated cytotoxicity of RK-33 in sarcoma cell lines...

BACKGROUND: The DDX3 helicase inhibitor RK-33 is a newly developed anticancer agent that showed promising results in preclinical research (Bol et al. EMBO Mol Med, 7(5):648-649, 2015). However, due to the physicochemical and pharmacological characteristics of RK-33, we initiated development of alternative formulations of RK-33 by preparing sustained release nanoparticles that can be administered intravenously. METHODS: In this study, RK-33 was encapsulated in poly(lactic-co-glycolic acid) (PLGA), one of the most well-developed biodegradable polymers, using the emulsion solvent evaporation method...

Identifying druggable targets in the Wnt-signaling pathway can optimize colorectal cancer treatment. Recent studies have identified a member of the RNA helicase family DDX3 (DDX3X) as a multilevel activator of Wnt signaling in cells without activating mutations in the Wnt-signaling pathway. In this study, we evaluated whether DDX3 plays a role in the constitutively active Wnt pathway that drives colorectal cancer. We determined DDX3 expression levels in 303 colorectal cancers by immunohistochemistry. 39% of tumors overexpressed DDX3...