Targeting TAOK1 with resveratrol inhibits esophageal squamous cell carcinoma growth in vitro and in vivo.

The worldwide incidence and mortality rates of esophageal squamous cell carcinoma (ESCC) have increased over the last decade. Moreover, molecular targets that may benefit the therapeutics of patients with ESCC have not been fully characterized. Our study discovered that thousand and one amino-acid protein kinase 1 (TAOK1) is highly expressed in ESCC tumor tissues and cell lines. Knock-down of TAOK1 suppresses ESCC cell proliferation in vitro and patient-derived xenograft or cell-derived xenograft tumors growth in vivo. Moreover, TAOK1 overexpression promotes ESCC growth in vitro and in vivo. Additionally, we identified that the natural small molecular compound resveratrol binds to TAOK1 directly and diminishes the kinase activity of TAOK1. Targeting TAOK1 directly with resveratrol significantly inhibits cell proliferation, induces cell cycle arrest and apoptosis, and suppresses tumor growth in ESCC. Furthermore, the silencing of TAOK1 or the application of resveratrol attenuated the activation of TAOK1 downstream signaling effectors. Interestingly, combining resveratrol with paclitaxel, cisplatin, or 5-fluorouracil synergistically enhanced their therapeutic effects against ESCC. In conclusion, this work illustrates the underlying oncogenic function of TAOK1 and provides a theoretical basis for the application of targeting TAOK1 therapy to the clinical treatment of ESCC.

OSGIN1 is a novel TUBB3 regulator that promotes tumor progression and gefitinib resistance in non-small cell lung cancer.

BACKGROUND: Oxidative stress induced growth inhibitor 1 (OSGIN1) regulates cell death. The role and underlying molecular mechanism of OSGIN1 in non-small cell lung cancer (NSCLC) are uncharacterized. METHODS: OSGIN1 expression in NSCLC samples was detected using immunohistochemistry and Western blotting. Growth of NSCLC cells and gefitinib-resistant cells expressing OSGIN1 or TUBB3 knockdown was determined by MTT, soft agar, and foci formation assays. The effect of OSGIN1 knockdown on in vivo tumor growth was assessed using NSCLC patient-derived xenograft models and gefitinib-resistant patient-derived xenograft models. Potentially interacting protein partners of OSGIN1 were identified using IP-MS/MS, immunoprecipitation, PLA, and Western blotting assays. Microtubule dynamics were explored by tubulin polymerization assay and immunofluorescence. Differential expression of signaling molecules in OSGIN1 knockdown cells was investigated using phospho-proteomics, KEGG analysis, and Western blotting. RESULTS: We found that OSGIN1 is highly expressed in NSCLC tissues and is positively correlated with low survival rates and tumor size in lung cancer patients. OSGIN1 knockdown inhibited NSCLC cell growth and patient-derived NSCLC tumor growth in vivo. Knockdown of OSGIN1 strongly increased tubulin polymerization and re-established gefitinib sensitivity in vitro and in vivo. Additionally, knockdown of TUBB3 strongly inhibited NSCLC cell proliferation. Mechanistically, we found that OSGIN1 enhances DYRK1A-mediated TUBB3 phosphorylation, which is critical for inducing tubulin depolymerization. The results of phospho-proteomics and ontology analysis indicated that knockdown of OSGIN1 led to reduced propagation of the MKK3/6-p38 signaling axis. CONCLUSIONS: We propose that OSGIN1 modulates microtubule dynamics by enhancing DYRK1A-mediated phosphorylation of TUBB3 at serine 172. Moreover, elevated OSGIN1 expression promotes NSCLC tumor growth and gefitinib resistance through the MKK3/6-p38 signaling pathway. Our findings unveil a new mechanism of OSGIN1 and provide a promising therapeutic target for NSCLC treatment in the clinic.

Targeting CRAF kinase in anti-cancer therapy: progress and opportunities.

The RAS/mitogen-activated protein kinase (MAPK) signaling cascade is commonly dysregulated in human malignancies by processes driven by RAS or RAF oncogenes. Among the members of the RAF kinase family, CRAF plays an important role in the RAS-MAPK signaling pathway, as well as in the progression of cancer. Recent research has provided evidence implicating the role of CRAF in the physiological regulation and the resistance to BRAF inhibitors through MAPK-dependent and MAPK-independent mechanisms. Nevertheless, the effectiveness of solely targeting CRAF kinase activity remains controversial. Moreover, the kinase-independent function of CRAF may be essential for lung cancers with KRAS mutations. It is imperative to develop strategies to enhance efficacy and minimize toxicity in tumors driven by RAS or RAF oncogenes. The review investigates CRAF alterations observed in cancers and unravels the distinct roles of CRAF in cancers propelled by diverse oncogenes. This review also seeks to summarize CRAF-interacting proteins and delineate CRAF's regulation across various cancer hallmarks. Additionally, we discuss recent advances in pan-RAF inhibitors and their combination with other therapeutic approaches to improve treatment outcomes and minimize adverse effects in patients with RAF/RAS-mutant tumors. By providing a comprehensive understanding of the multifaceted role of CRAF in cancers and highlighting the latest developments in RAF inhibitor therapies, we endeavor to identify synergistic targets and elucidate resistance pathways, setting the stage for more robust and safer combination strategies for cancer treatment.

Costunolide is a dual inhibitor of MEK1 and AKT1/2 that overcomes osimertinib resistance in lung cancer.

EGFR-TKI targeted therapy is one of the most effective treatments for lung cancer patients harboring EGFR activating mutations. However, inhibition response is easily attenuated by drug resistance, which is mainly due to bypass activation or downstream activation. Herein, we established osimertinib-resistant cells by stepwise dose-escalation in vitro and an osimertinib-resistant patient-derived xenograft model through persistent treatment in vivo. Phosphorylated proteomics identified that MEK1 and AKT1/2 were abnormally activated in resistant cells compared with parental cells. Likewise, EGFR inhibition by osimertinib induced activation of MEK1 and AKT1/2, which weakened osimertinib sensitivity in NSCLC cells. Consequently, this study aimed to identify a novel inhibitor which could suppress resistant cell growth by dual targeting of MEK1 and AKT1/2. Based on computational screening, we identified that costunolide could interact with MEK1 and AKT1/2. Further exploration using in vitro kinase assays validated that costunolide inhibited the kinase activity of MEK1 and AKT1/2, which restrained downstream ERK-RSK2 and GSK3ß signal transduction and significantly induced cell apoptosis. Remarkably, the combination of osimertinib and costunolide showed synergistic or additive inhibitory effects on tumor growth in osimertinib-resistant cell lines and PDX model. Hence, this study highlights a potential therapeutic strategy for osimertinib-resistant patients through targeting of MEK1 and AKT1/2 by costunolide.

Anwulignan is a novel JAK1 inhibitor that suppresses non-small cell lung cancer growth.

Anwulignan is a monomer compound derived from Schisandra sphenanthera lignans. It has been reported to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anticancer and hepatoprotective properties. However, its anticancer capacity and molecular mechanism(s) against non-small cell lung cancer (NSCLC) have not been fully elucidated. Anwulignan significantly inhibited cell growth and increased G1-phase cell cycle arrest in NSCLC cells. Anwulignan strongly attenuates the JAK1/STAT3 signalling pathway by directly targeting JAK1 protein kinase activity in vitro. The anticancer activity by Anwulignan is dependent upon the JAK1 protein expression. Remarkably, Anwulignan strongly inhibited tumour growth in vivo. In conclusion, Anwulignan is a novel JAK1 inhibitor that may have therapeutic implications for NSCLC management.

2,6-DMBQ suppresses cell proliferation and migration via inhibiting mTOR/AKT and p38 MAPK signaling pathways in NSCLC cells.

2,6-Dimethoxy-1,4-benzoquinone (2,6-DMBQ) is the major bioactive compound found in fermented wheat germ extract. Although fermented wheat germ extract has been reported to show anti-proliferative and anti-metabolic effects in various cancers, the anticancer potential and molecular mechanisms exerted by 2,6-DMBQ have not been investigated in non-small cell lung cancer (NSCLC) cells. Here, we report that 2,6-DMBQ suppresses NSCLC cell growth and migration through inhibiting activation of AKT and p38 MAPK. 2,6-DMBQ significantly suppressed anchorage-dependent and independent cell growth. Additionally, 2,6-DMBQ induced G2 phase cell cycle arrest through inhibiting the expression and phosphorylation of cyclin B1 and CDC2, respectively. Furthermore, 2,6-DMBQ strongly suppressed NSCLC cell migration through induction of E-cadherin expression. To determine the molecular mechanism(s) exerted by 2,6-DMBQ upon NSCLC cell lines, various signaling kinases were screened; the results indicate that 2,6-DMBQ strongly inhibits the phosphorylation of AKT and p38 MAPK. Additionally, the growth kinetics of cells treated with an AKT or p38 MAPK inhibitor in combination with 2,6-DMBQ indicate that 2,6-DMBQ suppresses NSCLC cell growth and migration through inhibition of AKT and p38 MAPK. Taken together, our results suggest that 2,6-DMBQ is a potential anticancer reagent against NSCLC cells and could be useful for treating lung cancer patients.

Harmaline isolated from Peganum harmala suppresses growth of esophageal squamous cell carcinoma through targeting mTOR.

Harmaline is a naturally occurring ß-carboline alkaloid that is isolated from Peganum harmala. It has shown efficacy in treating Parkinson's disease and has been reported to exhibit antimicrobial and anticancer properties. However, the molecular mechanism of harmaline in the context of esophageal squamous cell carcinoma (ESCC) has not been characterized. Here, we report that harmaline attenuates ESCC growth by directly targeting the mammalian target of rapamycin (mTOR). Harmaline strongly reduced cell proliferation and anchorage-independent cell growth. Additionally, harmaline treatment induced G2/M phase cell-cycle arrest through upregulation of p27. The results of in vitro and cell-based assays showed that harmaline directly inhibited the activity of mTOR kinase and the phosphorylation of its downstream pathway components. Depletion of mTOR using an shRNA-mediated strategy in ESCC cell lines indicated that reduced mTOR protein expression levels are correlated with decreased cell proliferation. Additionally, we observed that the inhibitory effect of harmaline was dependent upon mTOR expression. Notably, oral administration of harmaline suppressed ESCC patient-derived tumor growth in vivo. Taken together, harmaline is a potential mTOR inhibitor that might be used for therapeutically treating ESCC.

Persistent nuclear actin filaments inhibit transcription by RNA polymerase II.

Actin is abundant in the nucleus and it is clear that nuclear actin has important functions. However, mystery surrounds the absence of classical actin filaments in the nucleus. To address this question, we investigated how polymerizing nuclear actin into persistent nuclear actin filaments affected transcription by RNA polymerase II. Nuclear filaments impaired nuclear actin dynamics by polymerizing and sequestering nuclear actin. Polymerizing actin into stable nuclear filaments disrupted the interaction of actin with RNA polymerase II and correlated with impaired RNA polymerase II localization, dynamics, gene recruitment, and reduced global transcription and cell proliferation. Polymerizing and crosslinking nuclear actin in vitro similarly disrupted the actin-RNA-polymerase-II interaction and inhibited transcription. These data rationalize the general absence of stable actin filaments in mammalian somatic nuclei. They also suggest a dynamic pool of nuclear actin is required for the proper localization and activity of RNA polymerase II.

Kcnq1-5 (Kv7.1-5) potassium channel expression in the adult zebrafish.

BACKGROUND: KCNQx genes encode slowly activating-inactivating K+ channels, are linked to physiological signal transduction pathways, and mutations in them underlie diseases such as long QT syndrome (KCNQ1), epilepsy in adults (KCNQ2/3), benign familial neonatal convulsions in children (KCNQ3), and hearing loss or tinnitus in humans (KCNQ4, but not KCNQ5). Identification of kcnqx potassium channel transcripts in zebrafish (Danio rerio) remains to be fully characterized although some genes have been mapped to the genome. Using zebrafish genome resources as the source of putative kcnq sequences, we investigated the expression of kcnq1-5 in heart, brain and ear tissues. RESULTS: Overall expression of the kcnqx channel transcripts is similar to that found in mammals. We found that kcnq1 expression was highest in the heart, and also present in the ear and brain. kcnq2 was lowest in the heart, while kcnq3 was highly expressed in the brain, heart and ear. kcnq5 expression was highest in the ear. We analyzed zebrafish genomic clones containing putative kcnq4 sequences to identify transcripts and protein for this highly conserved member of the Kcnq channel family. The zebrafish appears to have two kcnq4 genes that produce distinct mRNA species in brain, ear, and heart tissues. CONCLUSIONS: We conclude that the zebrafish is an attractive model for the study of the KCNQ (Kv7) superfamily of genes, and are important to processes involved in neuronal excitability, cardiac anomalies, epileptic seizures, and hearing loss or tinnitus.

Targeting FGFR1 by ß,ß-dimethylacrylalkannin suppresses the proliferation of colorectal cancer in cellular and xenograft models.

BACKGROUND: Colorectal cancer (CRC) continues to be a major global health challenge, ranking as a top cause of cancer-related mortality. Alarmingly, the five-year survival rate for CRC patients hovers around a mere 10-30 %. The disruption of fibroblast growth factor receptor (FGFRs) signaling pathways is significantly implicated in the onset and advancement of CRC, presenting a promising target for therapeutic intervention in CRC management. Further investigation is essential to comprehensively elucidate FGFR1's function in CRC and to create potent therapies that specifically target FGFR1. PURPOSE: This study aims to demonstrate the oncogenic role of FGFR1 in colorectal cancer and to explore the potential of ß,ß-dimethylacrylalkannin (ß,ß-DMAA) as a therapeutic option to inhibit FGFR1. METHODS: In this research, we employed a comprehensive suite of techniques including tissue array, kinase profiling, computational docking, knockdown assay to predict and explore the inhibitor of FGFR1. Furthermore, we utilized kinase assay, pull-down, cell proliferation tests, and Patient derived xenograft (PDX) mouse models to further investigate a novel FGFR1 inhibitor and its impact on the growth of CRC. RESULTS: In our research, we discovered that FGFR1 protein is markedly upregulated in colorectal cancer tissues, suggesting a significant role in regulating cellular proliferation, particularly in patients with colorectal cancer. Furthermore, we conducted a computational docking, kinase profiling analysis, simulation and identified that ß,ß-DMAA could directly bind with FGFR1 within ATP binding pocket domain. Cell-based assays confirmed that ß,ß-DMAA effectively inhibited the proliferation of colon cancer cells and also triggered cell cycle arrest, apoptosis, and altered FGFR1-mediated signaling pathways. Moreover, ß,ß-DMAA effectively attenuated the development of PDX tumors in mice that were FGFR1-positive, with no notable toxicity observed. In summary, our study highlights the pivotal role of FGFR1 in colorectal cancer, suggesting that inhibiting FGFR1 activity could be a promising strategy for therapeutic intervention. We present strong evidence that targeting FGFR1 with ß,ß-DMAA is a viable approach for the management of colorectal cancer. Given its low toxicity and high efficacy, ß,ß-DMAA, as an FGFR1 inhibitor, warrants further investigation in clinical settings for the treatment of FGFR1-positive tumors.

Multi-omics characterization of esophageal squamous cell carcinoma identifies molecular subtypes and therapeutic targets.

Esophageal squamous cell carcinoma (ESCC) is the predominant form of esophageal cancer and is characterized by an unfavorable prognosis. To elucidate the distinct molecular alterations in ESCC and investigate therapeutic targets, we performed a comprehensive analysis of transcriptomics, proteomics, and phosphoproteomics data derived from 60 paired treatment-naive ESCC and adjacent nontumor tissue samples. Additionally, we conducted a correlation analysis to describe the regulatory relationship between transcriptomic and proteomic processes, revealing alterations in key metabolic pathways. Unsupervised clustering analysis of the proteomics data stratified patients with ESCC into 3 subtypes with different molecular characteristics and clinical outcomes. Notably, subtype III exhibited the worst prognosis and enrichment in proteins associated with malignant processes, including glycolysis and DNA repair pathways. Furthermore, translocase of inner mitochondrial membrane domain containing 1 (TIMMDC1) was validated as a potential prognostic molecule for ESCC. Moreover, integrated kinase-substrate network analysis using the phosphoproteome nominated candidate kinases as potential targets. In vitro and in vivo experiments further confirmed casein kinase II subunit α (CSNK2A1) as a potential kinase target for ESCC. These underlying data represent a valuable resource for researchers that may provide better insights into the biology and treatment of ESCC.

Cdc2-like kinases: structure, biological function, and therapeutic targets for diseases.

The CLKs (Cdc2-like kinases) belong to the dual-specificity protein kinase family and play crucial roles in regulating transcript splicing via the phosphorylation of SR proteins (SRSF1-12), catalyzing spliceosome molecular machinery, and modulating the activities or expression of non-splicing proteins. The dysregulation of these processes is linked with various diseases, including neurodegenerative diseases, Duchenne muscular dystrophy, inflammatory diseases, viral replication, and cancer. Thus, CLKs have been considered as potential therapeutic targets, and significant efforts have been exerted to discover potent CLKs inhibitors. In particular, clinical trials aiming to assess the activities of the small molecules Lorecivivint on knee Osteoarthritis patients, and Cirtuvivint and Silmitasertib in different advanced tumors have been investigated for therapeutic usage. In this review, we comprehensively documented the structure and biological functions of CLKs in various human diseases and summarized the significance of related inhibitors in therapeutics. Our discussion highlights the most recent CLKs research, paving the way for the clinical treatment of various human diseases.

Toosendanin targeting eEF2 impedes Topoisomerase I & II protein translation to suppress esophageal squamous cell carcinoma growth.

BACKGROUND: Although molecular targets such as HER2, TP53 and PIK3CA have been widely studied in esophageal cancer, few of them were successfully applied for clinical treatment. Therefore, it is urgent to discover novel actionable targets and inhibitors. Eukaryotic translational elongation factor 2 (eEF2) is reported to be highly expressed in various cancers. However, its contribution to the maintenance and progression of cancer has not been fully clarified. METHODS: In the present study, we utilized tissue array to evaluate eEF2 protein expression and clinical significance in esophageal squamous cell carcinoma (ESCC). Next, we performed knockdown, overexpression, RNA-binding protein immunoprecipitation (RIP) sequence, and nascent protein synthesis assays to explore the molecular function of eEF2. Furthermore, we utilized compound screening, Surface Plasmon Resonance (SPR), Isothermal Titration Calorimetry (ITC) assay, cell proliferation and Patient derived xenograft (PDX) mouse model assays to discover an eEF2 inhibitor and assess its effects on ESCC growth. RESULTS: We found that eEF2 were highly expressed in ESCC and negatively associated with the prognosis of ESCC patients. Knocking down of eEF2 suppressed the cell proliferation and colony formation of ESCC. eEF2 bond with the mRNA of Topoisomerase II (TOP1) and Topoisomerase II (TOP2) and enhanced the protein biosynthesis of TOP1 and TOP2. We also identified Toosendanin was a novel inhibitor of eEF2 and Toosendanin inhibited the growth of ESCC in vitro and in vivo. CONCLUSIONS: Our findings show that Toosendanin treatment suppresses ESCC growth through targeting eEF2 and regulating downstream TOP1 and TOP2 biosynthesis. eEF2 could be supplied as a potential therapeutic target in the further clinical studies.

The comparison of cancer gene mutation frequencies in Chinese and U.S. patient populations.

Knowing the mutation frequency of cancer genes in China is crucial for reducing the global health burden. We integrate the tumor epidemiological statistics with cancer gene mutation rates identified in 11,948 cancer patients to determine their weighted proportions within a Chinese cancer patient cohort. TP53 (51.4%), LRP1B (13.4%), PIK3CA (11.6%), KRAS (11.1%), EGFR (10.6%), and APC (10.5%) are identified as the top mutated cancer genes in China. Additionally, 18 common cancer types from both China and U.S. cohorts are analyzed and classified into three patterns principally based upon TP53 mutation rates: TP53-Top, TP53-Plus, and Non-TP53. Next, corresponding similarities and prominent differences are identified upon comparing the mutational profiles from both cohorts. Finally, the potential population-specific and environmental risk factors underlying the disparities in cancer gene mutation rates between the U.S. and China are analyzed. Here, we show and compare the mutation rates of cancer genes in Chinese and U.S. population cohorts, for a better understanding of the associated etiological and epidemiological factors, which are important for cancer prevention and therapy.

3,3'-Diindolylmethane plus Eflornithine suppress DNA Replication and Cell Cycle in Esophageal Squamous Cell Carcinoma in vivo.

Esophageal squamous cell carcinoma (ESCC) is a malignant cancer that is responsible for a high mortality rate; it accounts for approximately 90% of the 456,000 esophageal cancer (EC) cases diagnosed annually. Effective natural or synthesized compounds to prevent, treat, and/or inhibit ESCC relapse are desperately needed. The natural di-indole compound 3,3'-diindolylmethane (DIM) is abundant in cruciferous vegetables and shows potent anti-tumor effects in multiple cancers. The synthesized Eflornithine (DFMO) is clinically used to treat African sleeping sickness. We demonstrated that the combination of DIM+DFMO could significantly suppress the ESCC growth in the in vivo study of three patient-derived xenograft (PDX) cases. Then, the corresponding underlying anticancer mechanisms were investigated via the isobaric tags for relative and absolute quantification (iTRAQ) on the proteome level. We found that the DNA Replication and Cell Cycle were the top-2 most significantly downregulated signaling pathways following the DIM+DFMO treatment. Correspondingly and interestingly, these two pathways were the top-2 upregulated ones in clinic ESCC tumors. Moreover, the involved differentially expressed genes (DEGs) including MCM2, MCM3, MCM5, MCM6, MCM7, CDK1, and LIG1 were all inversely downregulated by DIM+DFMO treatment. In the limited clinical study in two ESCC cases, the administration of DIM (250mg) +DFMO (500 mg) once daily showed favorable results, including alleviated swallowing difficulties, decreased blood tumor markers (CA19-9, CA15-3 and AFP), and no severe toxicity in at least one month progression free survival period. We concluded that DIM+DFMO is a promising therapeutic combination for ESCC treatment via the suppression of DNA Replication and Cell Cycle activities. However, these therapeutic effects should be verified in large cohort clinical trials with sufficient cases.

Hippocalcin-like 1 is a key regulator of LDHA activation that promotes the growth of non-small cell lung carcinoma.

BACKGROUND: Hippocalcin-like 1 (HPCAL1), a neuronal calcium sensor protein family member, has been reported to regulate cancer growth. As yet, however, the biological functions of HPCAL1 and its molecular mechanisms have not been investigated in non-small cell lung carcinoma (NSCLC). METHODS: HPCAL1 expression in NSCLC samples was detected using immunohistochemistry, Western blotting and RT-PCR. The anticancer effects of HPCAL1 knockdown were determined by MTT, soft agar, cell cycle, oxygen consumption and reactive oxygen species assays. The effect of HPCAL1 knockdown on in vivo tumor growth was assessed using NSCLC cancer patient-derived xenograft models. Potentially interacting protein partners of HPCAL1 were identified using IP-MS/MS, immunoprecipitation and Western blotting assays. Metabolic alterations resulting from HPCAL1 knockdown were investigated using non-targeted metabolomics and RNA sequencing analyses. RESULTS: We found that HPCAL1 is highly expressed in NSCLC tissues and is positively correlated with low survival rates and AJCC clinical staging in lung cancer patients. Knockdown of HPCAL1 strongly increased oxygen consumption rates and the production of reactive oxygen species. HPCAL1 knockdown also inhibited NSCLC cell growth and patient-derived NSCLC tumor growth in vivo. Mechanistically, we found that HPCAL1 can directly bind to LDHA and enhance SRC-mediated phosphorylation of LDHA at tyrosine 10. The metabolomics and RNA sequencing analyses indicated that HPCAL1 knockdown reduces amino acid levels and induces fatty acid synthesis through regulating the expression of metabolism-related genes. Additionally, rescued cells expressing wild-type or mutant LDHA in HPCAL1 knockdown cells suggest that LDHA may serve as the main substrate of HPCAL1. CONCLUSIONS: Our data indicate that the effect of HPCAL1 knockdown on reducing SRC-mediated LDHA activity attenuates NSCLC growth. Our findings reveal novel biological functions and a mechanism underlying the role of HPCAL1 in NSCLC growth in vitro and in vivo.

BRD4 drives esophageal squamous cell carcinoma growth by promoting RCC2 expression.

The low survival rate of esophageal squamous cell carcinoma patients is primarily attributed to technical limitations and a lack of insight regarding the molecular mechanisms contributing to its progression. Alterations in epigenetic modulators are critical to cancer development and prognosis. BRD4, a chromatin reader protein, plays an essential role in regulating oncogene expression. Here, we investigated the contributing role of BRD4 and its related mechanisms in the context of ESCC tumor progression. Our observations showed that BRD4 transcript and protein expression levels are significantly increased in ESCC patient tissues. Genetic or pharmacological inhibition of BRD4 suppressed ESCC cell proliferation in vitro and in vivo. Proteomic and transcriptomic analyses were subsequently used to deduce the potential targets of BRD4. Mechanistic studies showed that RCC2 is a downstream target of BRD4. Inhibition of either BRD4 or RCC2 resulted in decreased ESCC cell proliferation. The BRD4-TP73 interaction facilitated the binding of BRD4 complex to the promoter region of RCC2, and subsequently modulated RCC2 transcription. Furthermore, targeting BRD4 with inhibitors significantly decreased tumor volume in ESCC PDX models, indicating that BRD4 expression may contribute to tumor progression. Collectively, these findings suggest that BRD4 inhibition could be a promising strategy to treat ESCC by downregulating RCC2.

A novel lncRNA MTAR1 promotes cancer development through IGF2BPs mediated post-transcriptional regulation of c-MYC.

Abnormal translation of the MYC proto-oncogene is a hallmark of the initiation and maintenance of tumorigenesis. However, the molecular mechanism underlying increased MYC protein levels in certain cancer types without a corresponding increase in MYC mRNA levels is unclear. Here, we identified a novel lncRNA, MTAR1, which is critical for post-transcriptional regulation of MYC-induced tumorigenesis. MTAR1 is essential for recruiting IGF2BPs into PABP1-mediated liquid-liquid phase separation (LLPS) complexes and facilitates IGF2BPs-mediated MYC mRNA translation. MTAR1 enhanced binding between IGF2BPs and PABP1, thereby promoting MYC mRNA stability and increased MYC mRNA translation. In summary, MTAR1 is a novel MYC-related lncRNA that contributes to tumor progression by enhancing MYC translation through mediating PABP1/IGF2BPs liquid-liquid phase separation.

Novel dual inhibitor for targeting PIM1 and FGFR1 kinases inhibits colorectal cancer growth in vitro and patient-derived xenografts in vivo.

Colorectal cancer (CRC) is the second most common cause of cancer-related death in the world. The pro-viral integration site for Moloney murine leukemia virus 1 (PIM1) is a proto-oncogene and belongs to the serine/threonine kinase family, which are involved in cell proliferation, migration, and apoptosis. Fibroblast growth factor receptor 1 (FGFR1) is a tyrosine kinase that has been implicated in cell proliferation, differentiation and migration. Small molecule HCI-48 is a derivative of chalcone, a class of compounds known to possess anti-tumor, anti-inflammatory and antibacterial effects. However, the underlying mechanism of chalcones against colorectal cancer remains unclear. This study reports that HCI-48 mainly targets PIM1 and FGFR1 kinases, thereby eliciting antitumor effects on colorectal cancer growth in vitro and in vivo. HCI-48 inhibited the activity of both PIM1 and FGFR1 kinases in an ATP-dependent manner, as revealed by computational docking models. Cell-based assays showed that HCI-48 inhibited cell proliferation in CRC cells (HCT-15, DLD1, HCT-116 and SW620), and induced cell cycle arrest in the G2/M phase through modulation of cyclin A2. HCI-48 also induced cellular apoptosis, as evidenced by an increase in the expression of apoptosis biomarkers such as cleaved PARP, cleaved caspase 3 and cleaved caspase 7. Moreover, HCI-48 attenuated the activation of downstream components of the PIM1 and FGFR1 signaling pathways. Using patient-derived xenograft (PDX) murine tumor models, we found that treatment with HCI-48 diminished the PDX tumor growth of implanted CRC tissue expressing high protein levels of PIM1 and FGFR1. This study suggests that the inhibitory effect of HCI-48 on colorectal tumor growth is mainly mediated through the dual-targeting of PIM1 and FGFR1 kinases. This work provides a theoretical basis for the future application of HCI-48 in the treatment of clinical CRC.

Oxethazaine inhibits esophageal squamous cell carcinoma proliferation and metastasis by targeting aurora kinase A.

Esophageal squamous cell carcinoma (ESCC), a malignant neoplasm with high incidence, is a severe global public health threat. The current modalities used for treating ESCC include surgery, chemotherapy, and radiotherapy. Although ESCC management and treatment strategies have improved over the last decade, the overall 5-year survival rate remains <20%. Therefore, the identification of novel therapeutic strategies that can increase ESCC patient survival rates is urgently needed. Oxethazaine, an amino-amide anesthetic agent, is mainly prescribed in combination with antacids to relieve esophagitis, dyspepsia, and other gastric disorders. In the present study, we found that oxethazaine inhibited the proliferation and migration of esophageal cancer cells. According to the results of in vitro screening and binding assays, oxethazaine binds directly to AURKA, suppresses AURKA activity, and inhibits the downstream effectors of AURKA. Notably, we found that oxethazaine suppressed tumor growth in three patient-derived esophageal xenograft mouse models and tumor metastasis in vivo. Our findings suggest that oxethazaine can inhibit ESCC proliferation and metastasis in vitro and in vivo by targeting AURKA.