Dasatinib enhances cisplatin sensitivity in human esophageal squamous cell carcinoma (ESCC) cells via suppression of PI3K/AKT and Stat3 pathways

Multiaction Pt(IV) Prodrugs Releasing Cisplatin and Dasatinib Are Potent Anticancer and Anti-Invasive Agents Displaying Synergism between the Two Drugs

Herein, we describe the general design, synthesis, characterization, and biological activity of new multitargeting Pt(IV) prodrugs that combine antitumor cisplatin and dasatinib, a potent inhibitor of Src kinase. These prodrugs exhibit impressive antiproliferative and anti-invasive activities in tumor cell lines in both two-dimensional (2D) monolayers of cell cultures and three-dimensional (3D) spheroids. We show that the cisplatin moiety and dasatinib in the investigated Pt(IV) complexes are both involved in the mechanism of action in MCF7 breast cancer cells and act synergistically. Thus, combining dasatinib and cisplatin into one molecule, compared to using individual components in a mix, may bring several advantages, such as significantly higher activity in cancer cell lines and higher selectivity for tumor cells. Most importantly, Pt(IV)-dasatinib complexes hold significant promise for potential anticancer therapies by targeting epithelial-mesenchymal transition, thus preventing the spread and metastasis of tumors, a value unachievable by a simple combination of both individual components.

Co-assembly of cisplatin and dasatinib in hyaluronan nanogel to combat triple negative breast cancer with reduced side effects

Treatment for triple negative breast cancer (TNBC) remains a huge challenge due to the lack of targeted therapeutics and tumor heterogenicity. Cisplatin (Cis) have demonstrated favorable therapeutic response in TNBC and thus is used together with various kinase inhibitors to fight the heterogenicity of TNBC. The combination of Cis with SRC inhibitor dasatinib (DAS) has shown encouraging anti-TNBC efficacy although the additive toxicity was commonly observed. To overcome the severe side effects of this Cis involved therapy, here we co-encapsulated Cis and DAS into a self-assembled hyaluronan (HA) nanogel (designated as HA/Cis/DAS (HCD) nanogel) to afford the TNBC targeted delivery by using the 4T1 mouse model. The acquired HCD nanogel was around 181 nm in aqueous solution, demonstrating the pharmacological activities of both Cis and DAS. Taking advantages of HA's targeting capability towards CD44 that is overexpressed on many TNBC cells, the HCD could well maintain the anticancer efficacy of the Cis and DAS combination, significantly increase the maximum tolerated dose and relieve the renal toxicity in vivo. The current HCD nanogel provides a potent strategy to improve the therapeutic outcome of Cis and DAS combination and thus representing a new targeted treatment option for TNBC.

Cuproptosis/OXPHOS tendency prediction of prognosis and immune microenvironment of esophageal squamous cell carcinoma: Bioinformatics analysis and experimental validation

BACKGROUND

Cuproptosis is a newly discovered cell death mechanism that relies on mitochondrial respiration, for which oxidative phosphorylation (OXPHOS) is an essential part. However, the detailed mechanisms of cuproptosis associated with OXPHOS in esophageal squamous cell carcinoma (ESCC) and how this correlation affects prognosis still remains unclear.

METHODS

scRNA-seq data of ESCC were downloaded from SRA (Sequence Read Archive) database. "AUCell" algorithm was used to grouping epithelial cells according to cuproptosis and OXPHOS score. Cell-cell communication, Pseudo-time Trajectory and transcription factor enrichment analysis were repectively conducted by "CellChat", "monocle3" package and "pySCENIC" algorithm. Univariate and LASSO cox regression analysis were used to construct the prognostic cuproptosis-OXPHOS signature. Finally, CCK-8 assay and DCFH-DA staining assay were respectively validated the sensitive and ROS production of elesclomol.

RESULTS

scRNA-seq data were analyzed to identify 10 core cell types. According to the median scores for cuproptosis and OXPHOS, malignant epithelial cells were divided into double high, double low, and mixed groups. The double high group distributed at the end of the pseudo-time trajectory and harbored HMGA1(+) as specific transcriptional regulons. Knockdown of HMGA1 partly reversed the inhibition of cell viability visualized by CCK-8 assay, while reactive oxygen species (ROS) production by elesclomol was enhanced after HMGA1 silencing. Furthermore, the immunosuppressive signal was significantly increased in the double high group detected by 'CellChat' in single-cell data and 'ssGSEA' in bulk data followed by 'CIBERSORTx' algorithm. Finally, a new cuproptosis-OXPHOS prognostic signature (CNN2, ATP6V0E1, PSMD6, CCDC25, IGFBP2, MT1E, and RPS4Y1) was constructed for the prediction of the prognosis, and a high-risk group corresponding to a more sensitive tendency to erlotinib, dasatinib, and bosutinib treatment was identified.

CONCLUSIONS

Our study revealed the relationship between OXPHOS and tendency of cuproptosis in ESCC, and malignant cells with this characteristic exerted immunosuppressive signals and indicated poor prognosis. Furthermore, we constructed the regulatory network in high cuproptosis-OXPHOS ESCC and identified HMGA1 as a potential regulator molecule of cuproptosis mediated by elesclomol.

PI3K/AKT and STAT3 pathways mediate the neuroprotective effect of dasatinib from acute cerebral injury in endotoxemic mice

Background and purpose

Sepsis induces brain dysfunction and there is still a requirement for an unemployed viable restorative approach. This study aimed to investigate the role of dasatinib in the modulation of proinflammatory mediators, attenuating neuroinflammatory response, and it's signaling pathway during endotoxemia.

Experimental approach

Twenty-four adult male Swiss-albino mice were randomized into four groups: sham (undergo laparotomy without cecal ligation and puncture, sepsis (laparotomy with cecal ligation and puncture), vehicle-dimethyl sulfoxide, dasatinib (20 mg/kg/day) intraperitoneally. Brain tissue used for assessment of interleukin (IL)-6, IL-1β, tumor necrosis factor-alpha (TNF-α), IL-10, Toll-like receptor 4 (TLR4), protein kinase B (AKT), phosphoinositide 3-kinases (PI3K), signal transducer and activator of transcription 3 (STAT3), and histopathological examination.

Findings/Results

Brain tissue levels of TNF-α, IL-6, and IL1 β were higher in the sepsis group than in the sham and vehicle groups. The dasatinib group had considerably lower tissue levels of these markers and significantly higher tissue values of IL-10 than the sepsis and vehicle groups. The sham group had much lower tissue values of TLR4, AKT, STAT3, and PI3k than in sepsis and vehicle groups. Furthermore, tissue levels of these markers in the dasatinib group were considerably lower than those in the sepsis and vehicle groups. Histopathology demonstrated that dasatinib might considerably reduce brain damage and the intensity of neuroinflammation when compared to sepsis and vehicle groups that showed extensive brain inflammation and damage.

Conclusion and implication

Dasatinib attenuated endotoxemia-induced acute brain damage in mice via modulating effects on TLR4, PI3K, AKT, and STAT3 downstream signaling pathways.

Drug repositioning for esophageal squamous cell carcinoma

Esophageal cancer (EC) remains a significant challenge globally, having the 8th highest incidence and 6th highest mortality worldwide. Esophageal squamous cell carcinoma (ESCC) is the most common form of EC in Asia. Crucially, more than 90% of EC cases in China are ESCC. The high mortality rate of EC is likely due to the limited number of effective therapeutic options. To increase patient survival, novel therapeutic strategies for EC patients must be devised. Unfortunately, the development of novel drugs also presents its own significant challenges as most novel drugs do not make it to market due to lack of efficacy or safety concerns. A more time and cost-effective strategy is to identify existing drugs, that have already been approved for treatment of other diseases, which can be repurposed to treat EC patients, with drug repositioning. This can be achieved by comparing the gene expression profiles of disease-states with the effect on gene-expression by a given drug. In our analysis, we used previously published microarray data and identified 167 differentially expressed genes (DEGs). Using weighted key driver analysis, 39 key driver genes were then identified. These driver genes were then used in Overlap Analysis and Network Analysis in Pharmomics. By extracting drugs common to both analyses, 24 drugs are predicted to demonstrate therapeutic effect in EC patients. Several of which have already been shown to demonstrate a therapeutic effect in EC, most notably Doxorubicin, which is commonly used to treat EC patients, and Ixazomib, which was recently shown to induce apoptosis and supress growth of EC cell lines. Additionally, our analysis predicts multiple psychiatric drugs, including Venlafaxine, as repositioned drugs. This is in line with recent research which suggests that psychiatric drugs should be investigated for use in gastrointestinal cancers such as EC. Our study shows that a drug repositioning approach is a feasible strategy for identifying novel ESCC therapies and can also improve the understanding of the mechanisms underlying the drug targets.

Role of PI3K/AKT pathway in squamous cell carcinoma with an especial focus on head and neck cancers

PI3K/AKT pathway is an important pathway in the carcinogenesis since it has central impacts in the regulation of metabolic pathways, cell proliferation and survival, gene expression and protein synthesis. This pathway has been reported to be dysregulated in several types of cancers. In the current review, we summarize the role of this signaling pathway in squamous cell carcinomas (SCCs) originated from different parts of body cervix, oral cavity, head and neck and skin. The data presented in the current review shows the impact of dysregulation of PI3K/AKT pathway in survival of patients with SCC. Moreover, targeted therapies against this pathway have been found to be effective in reduction of tumor burden both in animal models and clinical settings. Finally, a number of molecules that regulate PI3K/AKT pathway can be used as diagnostic markers for different types of SCCs.

Molecular mechanism, regulation, and therapeutic targeting of the STAT3 signaling pathway in esophageal cancer (Review)

Esophageal cancer (EC) is the seventh most common cancer globally, and the overall 5-year survival rate is only 20%. Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in EC, and its activation is associated with a poor prognosis. STAT3 can be activated by canonical pathways such as the JAK/STAT3 pathway as well as non-canonical pathways including the Wnt/STAT3 and COX2/PGE2/STAT3 pathways. Activated STAT3, present as phosphorylated STAT3 (p-STAT3), can be transported into the nucleus to regulate downstream genes, including VEGF, cyclin D1, Bcl-xL, and matrix metalloproteinases (MMPs), to promote cancer cell proliferation and induce resistance to therapy. Non-coding RNAs, including microRNAs (miRNAs/miRs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), play a vital role in regulating the STAT3 signaling pathway in EC. Several miRNAs promote or suppress the function of STAT3 in EC, while lncRNAs and circRNAs primarily promote the effects of STAT3 and the progression of cancer. Additionally, various drugs and natural compounds can target STAT3 to suppress the malignant behavior of EC cells, providing novel insights into potential EC therapies.

Development and Validation of a Ferroptosis-Related Gene Signature and Nomogram for Predicting the Prognosis of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor with high mortality and poor prognosis. Ferroptosis is a newly discovered form of cell death induced by iron-catalyzed excessive peroxidation of polyunsaturated fatty acids (PUFAs). However, the prognostic value of ferroptosis-related genes (FRGs) for ESCC remains unclear. Based on the ESCC dataset from the Gene Expression Omnibus (GEO) database, we identified 39 prognostic FRGs through univariate Cox regression analysis. After LASSO regression and multivariate Cox regression analyses, a multigene signature based on 10 prognostic FRGs was constructed and successfully divided ESCC patients into two risk groups. Patients in the low-risk group showed a significantly better prognosis than patients in the high-risk group. In addition, we combined the risk score with clinical predictors to construct a nomogram for ESCC. The predictive ability of the nomogram was further verified by ROC curves and calibration plots in both the training and validation sets. The predictive power of the nomogram was demonstrated to be better than that of either the risk score or clinical variable alone. Furthermore, functional analysis revealed that the 10-FRG signature was mainly associated with ferroptosis, differentiation and immune response. Connectivity map analysis identified potential compounds capable of targeting FRGs in ESCC. Finally, we demonstrated the prognostic value of SRC gene in ESCC using the clinical samples and found that SRC inhibition sensitized ESCC cells to ferroptosis inducers by in vitro experiments. In conclusion, we identified and verified a 10-FRG prognostic signature and a nomogram, which provide individualized prognosis prediction and provide insight into potential therapeutic targets for ESCC.

Carrier-free prodrug nanoparticles based on dasatinib and cisplatin for efficient antitumor in vivo

Carrier-free drug self-delivery systems consisting of amphiphilic drug-drug conjugate (ADDC) with well-defined structure and nanoscale features have drawn much attention in tumor drug delivery. Herein, we report a simple and effective strategy to prepare ADDC using derivatives of cisplatin (CP) and dasatinib (DAS), which further self-assembled to form reduction-responsive nanoparticles (CP-DDA NPs). DAS was modified with succinic anhydride and then connected with CP derivative by ester bonds. The size, micromorphology and in vitro drug release of CP-DDA NPs were characterized. The biocompatibility and bioactivity of these carrier-free nanoparticles were then investigated by HepG2 cells and H22-tumor bearing mice. In vitro and in vivo experiments proved that CP-DDA NPs had excellent anti-tumor activity and significantly reduced toxicities. This study provides a new strategy to design the carrier-free nanomedicine composed of CP and DAS for synergistic tumor treatment.

Evidence of Omics, Immune Infiltration, and Pharmacogenomic for SENP1 in the Pan-Cancer Cohort

Sentrin specific-protease 1 (SENP1) is a protein involved in deSUMOylation that is almost overexpressed in cancer. SENP1 has a determinative role in the activation of transcription programs in the innate immune responses and the development B of and C lymphocytes. We found, SENP1 possibly plays a critical role in immune infiltration and acts as an expression marker in PAAD, ESCA, and THYM. CD4+ T cells, CD8+ T cells, and macrophages were more key-related immune cells, indicating that SENP1 might be introduced as a potential target for cancer immunotherapy. We further showed that dysregulation of SENP1 is powerfully associated with decreased patient survival and clinical stage. Total SENP1 protein also increases in cancer. SENP1 is also controlled by transcription factors (TFs) CREB1, KDM5A, REST, and YY1 that regulates apoptosis, cell cycle, cell proliferation, invasion, tumorigenesis, and metastasis. These TFs were in a positive correlation with SENP1. MiR-138-5p, miR-129-1-3p, and miR-129-2-3p also inhibit tumorigenesis through targeting of SENP1. The SENP1 expression level positively correlated with the expression levels of UBN1, SP3, SAP130, NUP98, NUP153 in 32 tumor types. SENP1 and correlated and binding genes: SAP130, NUP98, and NUP153 activated cell cycle. Consistent with this finding, drug analysis was indicated SENP1 is sensitive to cell cycle, apoptosis, and RTK signaling regulators. In the end, SENP1 and its expression-correlated and functional binding genes were enriched in cell cycle, apoptosis, cellular response to DNA damage stimulus. We found that the cell cycle is the main way for tumorigenesis by SENP1. SENP1 attenuates the effect of inhibitory drugs on the cell cycle. We also introduced effective FDA-Approved drugs that can inhibit SENP1. Therefore in the treatments in which these drugs are used, SENP1 inhibition is a suitable approach. This study supplies a wide analysis of the SENP1 across The Cancer Genome Atlas (CGA) cancer types. These results suggest the potential roles of SENP1 as a biomarker for cancer. Since these drugs and the drugs that cause to resistance are applied to cancer treatment, then these two class drugs can use to inhibition of SENP1.

miR‑139‑5p enhances cisplatin sensitivity in non‑small cell lung cancer cells by inhibiting cell proliferation and promoting apoptosis via the targeting of Homeobox protein Hox‑B2

The development of chemotherapeutic dug resistance hinders the clinical treatment of cancer. MicroRNAs (miRNAs/miRs) have been revealed to serve essential roles in the drug resistance of numerous types of cancer. miR‑139‑5p was previously reported to be associated with cisplatin (DDP) sensitivity in human nasopharyngeal carcinoma cells and colorectal cancer cells. However, the effect and underlying mechanism of miR‑139‑5p in DDP sensitivity in non‑small cell lung cancer (NSCLC) cells has not yet been fully elucidated. In the present study, the expression of miR‑139‑5p and Homeobox protein Hox‑B2 (HOXB2) in NSCLC tissues was examined by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Subsequently, the effect of miR‑139‑5p on the DDP sensitivity of NSCLC cells in vitro was investigated. Cell proliferation was examined using a Cell Counting Kit‑8 assay. Western blotting was used to evaluate the protein expression of HOXB2, phosphorylated (p)‑PI3K, p‑AKT, caspase‑3 and cleaved‑caspase‑3, and RT‑qPCR was used to evaluate the expression of miR‑139‑5p, and the mRNA expression levels of HOXB2, PI3K, AKT and caspase‑3. The apoptotic rate of the cells was detected using flow cytometry. miR‑139‑5p expression in NSCLC tissues was shown to be significantly lower compared with that in adjacent tissues. Additionally, miR‑139‑5p increased cell apoptosis and inhibited NSCLC cell proliferation induced by DDP in vitro via modulating the PI3K/AKT/caspase‑3 signaling pathway. Furthermore, HOXB2 was identified to be a target of miR‑139‑5p, and miR‑139‑5p was revealed to sensitize NSCLC cells to DDP via the targeting of HOXB2. Taken together, the results of the present study demonstrated that regulating the expression of miR‑139‑5p could provide a novel approach to reverse DDP resistance and increase chemosensitivity in the treatment of NSCLC.

Cancer-derived IgG involved in cisplatin resistance through PTP-BAS/Src/PDK1/AKT signaling pathway

OBJECTIVES

This study aimed to explore whether knockdown of cancer-derived IgG (CIgG) could enhance cisplatin-induced anti-cancer effects.

MATERIALS AND METHODS

Cancer-derived IgG was knocked down by siRNA or Tet-on shRNA in the absence or presence of cisplatin in WSU-HN6 or CAL27 cells. Cell proliferation, apoptosis, and mobility were evaluated using CCK-8, flow cytometry, and transwell assays, respectively. Molecular events were investigated using real-time PCR and Western blot assays.

RESULTS

Knockdown of CIgG significantly promoted cisplatin-induced apoptosis and inhibition of cell proliferation, migration, and invasion. Cisplatin upregulated CIgG expression and phosphorylation of AKT and PDK1, while knockdown of CIgG downregulated phosphorylation of AKT and PDK1, and blocked cisplatin-induced upregulation of AKT and PDK1 phosphorylation. Moreover, knockdown of CIgG blocked cisplatin-induced upregulation of Src phosphorylation, and knockdown of Src blocked cisplatin-induced upregulation of AKT and PDK1 phosphorylation. Overexpression of Src upregulated AKT and PDK1 phosphorylation. Furthermore, knockdown of CIgG upregulated PTP-BAS mRNA and protein expression, whereas cisplatin downregulated PTP-BAS protein, but not mRNA expression; knockdown of PTP-BAS upregulated phosphorylation of Src, PDK1, AKT, and blocked CIgG knockdown-mediated enhancement of cisplatin-induced inhibition of cell proliferation.

CONCLUSION

Knockdown of CIgG enhanced the anti-cancer effects of cisplatin through PTP-BAS/Src/PDK1/AKT signaling pathway in oral squamous cell carcinoma.

BRE Promotes Esophageal Squamous Cell Carcinoma Growth by Activating AKT Signaling

Brain and reproductive organ-expressed protein (BRE) is aberrantly expressed in multiple cancers; however, its expression pattern in human esophageal squamous cell carcinoma (ESCC) and its role in ESCC progression remain unclear. In this study, we aimed to investigate the expression pattern of BRE in human ESCC and its role in ESCC progression. BRE was overexpressed in ESCC tissues compared with that in the adjacent non-tumor tissues. Forced expression of BRE was sufficient to enhance ESCC cell growth by promoting cell cycle progression and anti-apoptosis. Silencing of BRE suppressed these malignant phenotypes of ESCC cells. Mechanistic evaluation revealed that BRE overexpression activated the phosphorylation of AKT, and inhibition of the AKT pathway by MK2206 decreased the BRE-induced cell growth and apoptotic resistance in ESCC cells, highlighting the critical role of AKT signaling in mediating the effects of BRE. Moreover, the effects of BRE on ESCC cell growth and AKT activation were verified in a xenograft model in vivo. The present results show that BRE is overexpressed in ESCC tissues and contributes to the growth of ESCC cells by activating AKT signaling both in vitro and in vivo and provide insight into the role of BRE in AKT signaling and ESCC pathogenesis.

Identification of hub genes and therapeutic drugs in esophageal squamous cell carcinoma based on integrated bioinformatics strategy

Background

Esophageal squamous cell carcinoma (ESCC) is one of leading malignant cancers of gastrointestinal tract worldwide. Until now, the involved mechanisms during the development of ESCC are largely unknown. This study aims to explore the driven-genes and biological pathways in ESCC.

Methods

mRNA expression datasets of GSE29001, GSE20347, GSE100942, and GSE38129, containing 63 pairs of ESCC and non-tumor tissues data, were integrated and deeply analyzed. The bioinformatics approaches include identification of differentially expressed genes (DEGs) and hub genes, gene ontology (GO) terms analysis and biological pathway enrichment analysis, construction and analysis of protein-protein interaction (PPI) network, and miRNA-gene network construction. Subsequently, GEPIA2 database and qPCR assay were utilized to validate the expression of hub genes. DGIdb database was performed to search the candidate drugs for ESCC.

Results

Finally, 120 upregulated and 26 downregulated DEGs were identified. The functional enrichment of DEGs in ESCC were mainly correlated with cell cycle, DNA replication, deleted in colorectal cancer (DCC) mediated attractive signaling pathway, and Netrin-1 signaling pathway. The PPI network was constructed using STRING software with 146 nodes and 2392 edges. The most significant three modules in PPI were filtered and analyzed. Totally ten genes were selected and considered as the hub genes and nuclear division cycle 80 (NDC80) was closely related to the survival of ESCC patients. DGIdb database predicted 33 small molecules as the possible drugs for treating ESCC.

Conclusions

In summary, the data may provide new insights into ESCC pathogenesis and treatments. The candidate drugs may improve the efficiency of personalized therapy in future.

Targeting Upstream Kinases of STAT3 in Human Medulloblastoma Cells

BACKGROUND

Medulloblastoma is the most common malignant brain tumor in children. Despite improvement in overall survival rate, it still lacks an effective targeted treatment strategy. The Janus family of cytoplasmic tyrosine kinases (JAKs) and Src kinases, upstream protein kinases of signal transducer and activator of transcription 3 (STAT3), play important roles in medulloblastoma pathogenesis and therefore represent potential therapeutic targets.

METHODS

In this report, we examined the inhibitory efficacy of the JAK1/2 inhibitor, ruxolitinib, the JAK3 inhibitor, tofacitinib and two Src inhibitors, KX2-391 and dasatinib.

RESULTS

These small molecule drugs significantly reduce cell viability and inhibit cell migration and colony formation in human medulloblastoma cells in vitro. Src inhibitors have more potent efficacy than JAK inhibitors in inhibiting medulloblastoma cell migration ability. The Src inhibitors can inhibit both phosphorylation of STAT3 and Src while JAK inhibitors reduce JAK/STAT3 phosphorylation. We also investigated the combined effect of the Src inhibitor, dasatinib with cisplatin. The results show that dasatinib exerts synergistic effects with cisplatin in human medulloblastoma cells through the inhibition of STAT3 and Src.

CONCLUSION

Our results suggest that the small molecule inhibitors of STAT3 upstream kinases, ruxolitinib, tofacitinib, KX2-391, and dasatinib could be novel and attractive candidate drugs for the treatment of human medulloblastoma.

BAG2 Overexpression Correlates with Growth and Poor Prognosis of Esophageal Squamous Cell Carcinoma

Previous studies have suggested that Bcl2-associated athanogene 2 (BAG2) serves as a crucial regulator for tumorigenesis in multiple tumors. However, little is known about the effect of BAG2 on esophageal squamous cell carcinoma (ESCC). This study focused on investigating whether BAG2 functions as a cancer-promoting gene in ESCC. In this work, gene expression data and clinical information from the NCBI Gene Expression Omnibus (GEO), Oncomine and The Cancer Genome Atlas (TCGA) were collected and analyzed. Expression of BAG2 in ESCC was determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR). BAG2 was knocked down using small interference RNA (si-RNA) approach. Cell proliferation, migration and invasion were assessed by Cell Counting Kit-8 (CCK-8) and transwell assays. Molecular mechanism was detected by western blotting assay. The expression of BAG2 both in ESCC tissues and cells was upregulated and overexpression was associated with worsened prognosis. BAG2 silencing inhibited ESCC cell proliferation, migration and invasion, which was regulated by the phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (AKT) signaling pathway. These results reveal contributions of BAG2 as a predictor and potential therapeutic target in ESCC.

Focal adhesion kinase activation limits efficacy of Dasatinib in c-Myc driven hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a deadly malignancy with limited treatment options. Recently, it was found that Dasatinib treatment led to synthetic lethality in c-Myc high-expressing human cancer cells due to inhibition of p-Lyn. Overexpression of c-Myc is frequently seen in human HCC. We investigated the sensitivity to Dasatinib in vitro using HCC cell lines and in vivo using c-Myc mouse HCC model. We found that HCC cell line responsiveness to Dasatinib varied significantly. However, there was no correlation between c-Myc expression and IC50 to Dasatinib. In c-Myc-induced HCC in mice, tumors continued to grow despite Dasatinib treatment, although the eventual tumor burden was lower in Dasatinib treatment cohort. Molecular analyses revealed that Dasatinib was effective in inhibiting p-Src, but not p-Lyn, in HCC. Importantly, we found that in HCC cell lines as well as c-Myc mouse HCC, Dasatinib treatment induced up regulation of activated/phosphorylated (p)-focal adhesion kinase(FAK). Concomitant treatment of HCC cell lines with Dasatinib and FAK inhibitor prevented Dasatinib-induced FAK activation, leading to stronger growth restraint. Altogether, our results suggest that Dasatinib may have limited efficacy as single agent for HCC treatment. Combined treatment with Dasatinib with FAK inhibitor might represent a novel therapeutic approach against HCC.

ANXA2 promotes esophageal cancer progression by activating MYC-HIF1A-VEGF axis

BACKGROUND

ANXA2 (Annexin A2) is a pleiotropic calcium-dependent phospholipid binding protein that is abnormally expressed in various cancers. We previously found that ANXA2 is upregulated in esophageal squamous cell carcinoma (ESCC). This study was designed to investigate the functional significance of ANXA2 dysregulation and underlying mechanism in ESCC.

METHODS

Proliferation, migration, invasion and metastasis assay were performed to examine the functional roles of ANXA2 in ESCC cells in vitro and in vivo. Real-time RT-PCR, immunoblotting, ChIP, reporter assay, confocal-immunofluorescence staining, co-immunoprecipitation and ubiquitination assay were used to explore the molecular mechanism underlying the actions of deregulated ANXA2 in ESCC cells.

RESULTS

Overexpression of ANXA2 promoted ESCC cells migration and invasion in vitro and metastasis in vivo through activation of the MYC-HIF1A-VEGF cascade. Notably, ANXA2 phosphorylation at Tyr23 by SRC led to its translocation into the nucleus and enhanced the metastatic potential of ESCC cells. Phosphorylated ANXA2 (Tyr23) interacted with MYC and inhibited ubiquitin-dependent proteasomal degradation of MYC protein. Accumulated MYC directly potentiated HIF1A transcription and then activated VEGF expression. Correlation between these molecules were also found in ESCC tissues. Moreover, dasatinib in combination with bevacizumab or ANXA2-siRNA produced potent inhibitory effects on the growth of ESCC xenograft tumors in vivo.

CONCLUSIONS

This study provides evidence that highly expressed p-ANXA2 (Tyr23) contributes to ESCC progression by promoting migration, invasion and metastasis, and suggests that targeting the SRC-ANXA2-MYC-HIF1A-MYC axis may be an efficient strategy for ESCC treatment.

Metformin inhibits the proliferation and metastasis of osteosarcoma cells by suppressing the phosphorylation of Akt

Metformin (Met) is a therapeutic agent for the treatment of type 2 diabetes mellitus. There is evidence that Met may reduce the risk of cancer in patients with type 2 diabetes mellitus by inhibiting tumor cell growth, prolonging the overall survival time in patients with various types of malignancy. However, the function and mechanism of Met have not been fully elucidated in osteosarcoma (OS). The present study evaluated the anti-proliferative effect of Met on MG63 and U2OS OS cells, identifying that it acted in a dose- and time-dependent manner. Met also inhibited OS cell migration and invasion, potentially by regulating the epithelial-mesenchymal transition in OS cells. Mechanistically, Met was demonstrated to partly exert these functions through the suppression of Akt phosphorylation, which was associated with increased phosphatase and tensin (PTEN) expression. Silencing PTEN prevented the Met-induced inhibition of the growth and metastasis of OS cells. As Met has anti-proliferative and anti-metastatic effects on OS cells it is a potential candidate, in combination with other chemotherapeutic agents, for use in the treatment of OS.

Dasatinib modulates sensitivity to pemetrexed in malignant pleural mesothelioma cell lines

Background

Thymidylate synthase (TS), one of the key enzymes for thymidine synthesis, is a target of pemetrexed (PEM), a key agent for the systemic therapy of malignant pleural mesothelioma (MPM) and its overexpression has been correlated to PEM-resistance. In MPM, experimental data report activation of the c-SRC tyrosine kinase suggesting it as a potential target to be further investigated.

Results

MPM cell lines showed different sensitivity, being MSTO the most and REN the least sensitive to PEM. REN cells showed high levels of both TS and SRC: dasatinib inhibited SRC activation and suppressed TS protein expression, starting from 100 nM dose, blocking the PEM-induced up regulation of TS protein levels. Dasatinib treatment impaired cells migration, and both sequential and co-administration with PEM significantly increased apoptosis. Dasatinib pretreatment improved sensitivity to PEM, downregulated TS promoter activity and, in association with PEM, modulated the downstream PI3K-Akt-mTOR signaling.

Cell lines and Methods

In three MPM cell lines (MPP89, REN and MSTO), the effects of c-SRC inhibition, in correlation with TS expression and PEM sensitivity, were evaluated. PEM and dasatinib, a SRC inhibitor, were administered as single agents, in combination or sequentially. Cell viability, apoptosis and migration, as well as TS expression and SRC activation have been assessed.

Conclusions

These data indicate that dasatinib sensitizes mesothelioma cells to PEM through TS down-regulation.

eIF4E promotes tumorigenesis and modulates chemosensitivity to cisplatin in esophageal squamous cell carcinoma

Patients with esophageal squamous cell cancer are often diagnosed with advanced diseases that respond poorly to chemotherapy. Overexpression of eIF4E leads to enhance the translation of key malignancy-related proteins and enabling tumor growth and chemoresistance in a variety of human malignancies, but whether it has a role in ESCC remains obscure. We hypothesized that eIF4E promoted ESCC tumorigenesis and facilitated the development of acquired resistance to the cisplatin-based chemotherapy. In this study, we showed that eIF4E expression was increased significantly in clinical ESCC tissues and and ESCC cell lines and its expression level was correlated with lymph node metastasis, TNM stage, as well as overall and disease-free survival of ESCC. We also showed here that knockdown of eIF4E in EC9706 would dramatically reduced cell proliferation, colony formation, migration and invasion, apoptosis in vitro as well as in vivo, and vice versa. Moreover, "weak mRNAs" were demonstrated to be regulated by eIF4E in ESCC, which might interpret the above function. Overexpression of eIF4E decreased the efficacy of cisplatin-induced cell growth inhibition in ESCC cell line and xenograft model (P < 0.05). eIF4E knockdown by shRNA increased cisplatin-induced cytotoxicity in ESCC cell lines, and enhanced chemosensitivity to cisplatin in xenograft tumor models. Furthermore, we found that the PI3K/AKT pathway and Bcl-2/Bax ratio might be responsible for the eIF4E-induced cisplatin resistance in ESCC. Our data collectively show association of eIF4E expression with chemotherapeutic response in ESCC, and suggest that therapeutically targeting eIF4E may be a viable means of improving chemotherapy response in ESCC.

Rabdocoestin B exhibits antitumor activity by inducing G2/M phase arrest and apoptosis in esophageal squamous cell carcinoma

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive squamous cell carcinomas and is generally resistant to chemotherapy. In the present study, the cytotoxic activity of Rabdocoestin B (Rabd-B) against ESCC and the underlying mechanisms were investigated.

METHODS

The inhibitory effect of Rabd-B on KYSE30 and KYSE450 was evaluated by Cell Counting Kit-8 (CCK8) and colony formation assays in vitro. The cell cycle distribution and apoptosis of cells treated with Rabd-B were determined by flow cytometry. The mechanisms underlying the effects of Rabd-B were systematically examined by Western blot. The in vivo anti-tumor ability of Rabd-B was measured in mouse xenograft models and cisplatin (DDP) was used as positive control.

RESULTS

Rabd-B efficiently induced G2/M phase arrest in ESCC cells by upregulating the Chk1/Chk2-Cdc25C axis to inhibit the G2→M transition facilitated by Cdc2/Cyclin B1. Furthermore, Rabd-B suppressed ATM/ATR phosphorylation, thereby inhibiting BRCA1-mediated DNA repair, which resulted in mitotic catastrophe and induced cell apoptosis. Rabd-B also decreased the activity of the Akt and NF-κB survival signaling pathways and ultimately initiated the caspase-9-dependent intrinsic apoptotic pathway in ESCC cells. The apoptosis induced by Rabd-B could be partially reversed by a caspase-9-specific inhibitor (Z-LEHD-FMK) and a pan-caspase inhibitor (Z-VAD-FMK). Moreover, Rabd-B effectively suppressed tumor growth in mouse xenografts which was comparable to that of DDP without significant injuries to the mice.

CONCLUSION

Taken together, these findings indicate that Rabd-B is a promising precursor compound that may be useful as a treatment for ESCC and thus warrants further investigation.

Identification of the key transcription factors in esophageal squamous cell carcinoma

Background

Esophageal cancer (EC) is a common human malignancy worldwide. Esophageal squamous cell carcinoma (ESCC) is the predominant subtype in China. The tumorigenesis mechanism in ESCC is unclear. The aim of this study was to identify key transcription factors (TFs) in ESCC and elucidate the mechanism of it.

Methods

A total of ten published microarray datasets of ESCC was downloaded from the Gene Expression Omnibus (GEO). Then, bioinformatics analyses including differentially expressed genes (DEGs) analysis, gene ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, TFs-genes regulatory network construction was performed. Quantitative real-time polymerase chain reactions (qRT-PCR) were used to detect the expression levels of TFs and DEGs in ESCC. The association between stage and TFs and the association between survival and TFs were evaluated based on The Cancer Genome Atlas (TCGA), respectively.

Results

A total of 1,248 dysregulated genes were selected as DEGs in ESCC. A total of 26 TFs and corresponding target-genes were identified. The ESCC-specific transcriptional regulatory network was constructed. The network was consisted of 882 edges and 631 nodes. BRCA1, SOX10, ARID3A, ZNF354C and NFIC had the highest connectivity with DEGs, and regulated 92, 89, 82, 79 and 78 DEGs in the network, respectively. All these 1,248 DEGs were significantly enriched in cell cycle, DNA replication and oocyte meiosis pathways. The qRT-PCR results were consistent with our microarray analysis. High expression of SREBF1 and TFAP2A were significantly correlated with the longer overall survival time of patients with ESCC.

Conclusions

BRCA1, SOX10, ARID3A, ZNF354C and NFIC might be the key TFs in carcinogenesis and development of ESCC by regulating their corresponding target-genes involved in cell cycle, DNA replication and oocyte meiosis pathways. SREBF1 and TFAP2A may be two potential prognostic biomarkers of ESCC.

Differentially activated Src kinase in chemo-naïve human primary osteosarcoma cells and effects of a Src kinase inhibitor

The therapeutic treatment of osteosarcoma (OS), a rare malignant teenage cancer of the skeletal system, still represents a great challenge as patient survival after conventional protocol chemotherapy treatment has not improved in the last four decades leaving poor patient prognoses. Therefore, many efforts have been done to find increasingly reliable OS cell models and to identify "druggable" targets in OS, in order to identify novel effective therapeutic approaches and treatment strategies. In this contest, the more successful use of patient-derived cell cultures in respect to human commercial lines and findings of Src kinase deregulation in cancer, prompted us to study for the first time the activation state of Src and the potential activity of our Src inhibitor SI-83 in a number of chemo-naïve patient-derived primary OS cells. We here demonstrate that Src is hyperactivated in OS cells in respect to the nonmalignant counterpart and that SI-83 is able to strongly decrease cell viability, proliferation, Src₄₁₆ phosphorylation, and cell migration. © 2017 BioFactors, 43(6):801-811, 2017.

Targeting super-enhancer-associated oncogenes in oesophageal squamous cell carcinoma

OBJECTIVES

Oesophageal squamous cell carcinoma (OSCC) is an aggressive malignancy and the major histological subtype of oesophageal cancer. Although recent large-scale genomic analysis has improved the description of the genetic abnormalities of OSCC, few targetable genomic lesions have been identified, and no molecular therapy is available. This study aims to identify druggable candidates in this tumour.

DESIGN

High-throughput small-molecule inhibitor screening was performed to identify potent anti-OSCC compounds. Whole-transcriptome sequencing (RNA-Seq) and chromatin immunoprecipitation sequencing (ChIP-Seq) were conducted to decipher the mechanisms of action of CDK7 inhibition in OSCC. A variety of in vitro and in vivo cellular assays were performed to determine the effects of candidate genes on OSCC malignant phenotypes.

RESULTS

The unbiased high-throughput small-molecule inhibitor screening led us to discover a highly potent anti-OSCC compound, THZ1, a specific CDK7 inhibitor. RNA-Seq revealed that low-dose THZ1 treatment caused selective inhibition of a number of oncogenic transcripts. Notably, further characterisation of the genomic features of these THZ1-sensitive transcripts demonstrated that they were frequently associated with super-enhancer (SE). Moreover, SE analysis alone uncovered many OSCC lineage-specific master regulators. Finally, integrative analysis of both THZ1-sensitive and SE-associated transcripts identified a number of novel OSCC oncogenes, including PAK4, RUNX1, DNAJB1, SREBF2 and YAP1, with PAK4 being a potential druggable kinase.

CONCLUSIONS

Our integrative approaches led to a catalogue of SE-associated master regulators and oncogenic transcripts, which may significantly promote both the understanding of OSCC biology and the development of more innovative therapies.

Plasticity of Cancer Cell Invasion-Mechanisms and Implications for Therapy

Cancer cell migration is a plastic and adaptive process integrating cytoskeletal dynamics, cell-extracellular matrix and cell-cell adhesion, as well as tissue remodeling. In response to molecular and physical microenvironmental cues during metastatic dissemination, cancer cells exploit a versatile repertoire of invasion and dissemination strategies, including collective and single-cell migration programs. This diversity generates molecular and physical heterogeneity of migration mechanisms and metastatic routes, and provides a basis for adaptation in response to microenvironmental and therapeutic challenge. We here summarize how cytoskeletal dynamics, protease systems, cell-matrix and cell-cell adhesion pathways control cancer cell invasion programs, and how reciprocal interaction of tumor cells with the microenvironment contributes to plasticity of invasion and dissemination strategies. We discuss the potential and future implications of predicted "antimigration" therapies that target cytoskeletal dynamics, adhesion, and protease systems to interfere with metastatic dissemination, and the options for integrating antimigration therapy into the spectrum of targeted molecular therapies.

RUNX3 reverses cisplatin resistance in esophageal squamous cell carcinoma via suppression of the protein kinase B pathway

Background

Preoperative chemoradiation combined with surgery has been of focus recently in order to improve prognosis in esophageal squamous cell carcinoma (ESCC) patients. Finding biological markers that may assist in predicting the therapeutic effect of chemoradiation may benefit the treatment effect. In this study, the role of RUNX3 in the formation of cisplatin resistance in ESCC was examined.

Methods

The study enrolled 103 stage IIa–IIIb ESCC patients who had undergone esophagectomy. RUNX3 expression in ESCC tissue was detected.

Results

A higher expression of RUNX3 in ESCC patients correlated with a more sensitive response to cisplatin‐based chemotherapy. A consistently lower expression of RUNX3 was found in the ESCC tissues of patients who agreed to perioperative chemotherapy compared with patients who had undergone no preoperative treatment. A lower RUNX3 expression in cisplatin‐resistant ESCC cell lines, Eca109 and TE‐1, was observed compared with parental cell lines. Heterologous RUNX3 expression significantly suppressed cisplatin resistance in Eca109 and TE‐1, both in vitro and vivo. Meanwhile, heterologous RUNX3 expression could inhibit growth and induce apoptosis in cisplatin resistant Eca109 and TE‐1 cell lines in vitro. Remarkable inhibition of the Akt pathway was observed in heterologous RUNX3 expression in Eca109 and TE‐1. Silencing Akt1 could reverse cisplatin resistance in Eca109 and TE‐1.

Conclusion

Our results confirmed that a loss of RUNX3 in ESCC may contribute to cisplatin‐resistance. RUNX3 could reverse cisplatin resistance via suppression of the Akt pathway in ESCC patients.

Lyn, a tyrosine kinase closely linked to the differentiation status of primary acute myeloid leukemia blasts, associates with negative regulation of all-trans retinoic acid (ATRA) and dihydroxyvitamin D3 (VD3)-induced HL-60 cells differentiation

Background

Lyn, an import member of Src family kinases (SFKs), is supposed to be implicated in acute myeloid leukemia (AML) pathogenesis and development by participation in AML differentiation, yet the details still remain incompletely understood. The expression status of Lyn and its correlation with multiple clinical parameters including cell differentiation degree, different cytogenetic risk classification, and the activity of myeloperoxidase (MPO) were thus investigated. To address the mechanisms underlying the involvement of Lyn in differentiation induction, the effects of dasatinib, an inhibitor for SFKs including Lyn, on the alterations of all-trans retinoic acid (ATRA)- or dihydroxyvitamin D3 (VD3)-induced differentiation, and c-Myc protein expression were investigated.

Methods

Primary AML blasts were obtained from 31 newly diagnosed AML patients with different French-American-British (FAB) subtypes. The expression of phosphorylated and total Lyn, c-Myc, and CD11b, CD11c and CD15 was analyzed by flow cytometry. The activation of Akt and Erk known to be involved in the regulation of c-Myc expression was investigated using western blotting.

Results

Significant higher expression levels of total Lyn were observed in AML patients with favorable cytogenetics, higher MPO activity and FAB M2 subtype. A clear positive correlation between the expression levels of Lyn and differentiation status of primary AML blasts was observed. Dasatinib inhibited the expression of phosphorylated Lyn, and further enhanced the differentiation-inducing activity of ATRA and VD3 in HL-60 cells. Augmented downregulation of c-Myc protein expression was observed in the combination treatment with ATRA, VD3 and dasatinib compared to treatment with each reagent alone in HL-60 cells. The suppression of the activation of Akt and Erk was also observed concomitantly.

Conclusions

The expression level of total Lyn is closely linked to the differentiation status of AML blasts. The enhancement of differentiation-inducing activity of ATRA/VD3 by dasatinib suggested that Lyn was associated in the negative regulation of ATRA/VD3-induced HL-60 cells differentiation. The enhancement probably was attributed to the downregulation of c-Myc implicated with the suppression of the activation of Akt and Erk. These results provide novel insights into a possible combinational therapeutic approach by targeting Lyn for AML patients, and offer new possibilities for the combination therapy with VD3 and dasatinib.

Clinicopathological significance of STAT4 in hepatocellular carcinoma and its effect on cell growth and apoptosis

Background

Recent studies showed that signal transducer and activator of transcription 4 (STAT4) was downregulated in hepatocellular carcinoma (HCC) tissues. However, the role of STAT4 in HCC is still unknown. The aim of this study is to explore the association between STAT4 expression and other clinicopathological features in HCC and to test the effect of STAT4 on cell growth and apoptosis in vitro.

Methods

STAT4 was evaluated by immunohistochemistry in 171 HCC and corresponding paraneoplastic liver, 37 cirrhosis, and 33 normal liver tissues. Association between STAT4 and clinicopathological parameters was analyzed. Meta-analysis on STAT4 in cancer was performed. The effect of STAT4 small interfering RNA (siRNA) on cell growth and cell apoptosis was also detected.

Results

Positive rate of STAT4 was 29.2% (50/171) in HCC tissues, 53.2% (91/171) in paraneoplastic liver tissues, 64.9% (24/37) in cirrhosis tissues, and 72.7% (24/33) in normal liver tissues. STAT4 was upregulated in younger patients who were female, with single tumor node, early TNM stage, without portal vein tumor embolus, and α-fetoprotein (AFP)-positive tumors compared with the groups comprising older patients, males, and those with multiple tumor nodes, advanced TNM stage, with portal vein tumor embolus, and AFP negative tumors. Meta-analysis showed STAT4 was correlated with TNM stage (OR =0.50, 95% CI =0.30, 0.83, P=0.008) and age (OR =0.58, 95% CI =0.38, 0.95, P=0.032) in malignant tissues, and with AFP level (OR =1.76, 95% CI =1.06, 2.94, P=0.03) in HCC. STAT4 siRNA promoted growth and suppressed apoptosis of HepG2 cells.

Conclusion

STAT4 might play a vital role in development of HCC, via influencing cell growth and apoptosis, as a tumor suppressor.

A Mechanism for the Temporal Potentiation of Genipin to the Cytotoxicity of Cisplatin in Colon Cancer Cells

OBJECTIVES

To investigate the potentiation effect of Genipin to Cisplatin induced cell senescence in HCT-116 colon cancer cells in vitro.

METHODS

Cell viability was estimated by Propidium iodide and Hoechst 3342, reactive oxygen species (ROS) with DHE, mitochondrial membrane potential (MMP) with JC-1 MMP assay Kit and electron current production with microbial fuel cells (MFC).

RESULTS

Genipin inhibited the UCP2 mediated anti-oxidative proton leak significantly promoted the Cisplatin induced ROS and subsequent cell death, which was similar to that of UCP2-siRNA. Cells treated with Cisplatin alone or combined with Genipin, ROS negatively, while MMP positively correlated with cell viability. Cisplatin induced ROS was significantly decreased by detouring electrons to MFC, or increased by Genipin combined treatment. Compensatory effects of UCP2 up-regulation with time against Genipin treatment were suggested. Shorter the Genipin treatment before Cisplatin better promoted the Cisplatin induced ROS and subsequent cell death.

CONCLUSION

The interaction of leaked electron with Cisplatin was important during ROS generation. Inhibition of UCP2-mediated proton leak with Genipin potentiated the cytotoxicity of Cisplatin. Owing to the compensatory effects against Genipin, shorter Genipin treatment before Cisplatin was recommended in order to achieve better potentiation effect.