Role of TOPK in lipopolysaccharide-induced breast cancer cell migration and invasion

Targeting Store-Operated Calcium Entry Regulates the Inflammation-Induced Proliferation and Migration of Breast Cancer Cells

Persistent challenges complicating the treatment of breast cancer remain, despite some recent undeniable successes. Sufficient evidence currently exists demonstrating the crucial role of inflammation, characterized by the enhanced activation of Toll-like receptor 4 (TLR4) and the COX-2/PGE2 pathway, in the migration and proliferation of breast cancer cells. Interestingly, the store-operated calcium entry (SOCE) pathway was shown to be essential for the TLR4 activity and COX-2 expression in immune cells such as macrophages and microglia. However, whether SOCE influences inflammatory signaling and the inflammation-induced proliferation and migration of breast cancer cells is still unknown. Thus, the current study intended to delineate the role of SOCE in the TLR4-induced inflammation, migration, and proliferation of breast cancer cells. To this end, MDA-MB-231 breast cancer cells were treated with lipopolysaccharide (LPS) to activate TLR4, BTP2 to inhibit SOCE, and Thapsigargin to induce SOCE. Following these treatments, several experiments were conducted to evaluate the proliferation and migration rates of the MDA-MB-231 cells and the expression of several inflammatory and oncogenic genes, including COX-2, PGE2, IL-6, IL-8, and VEGF. Different techniques were used to achieve the aims of this study, including qRT-PCR, Western blotting, ELISA, MTT, and wound healing assays. This study shows that SOCE inhibition using BTP2 suppressed the LPS-induced migration and proliferation of breast cancer cells. Additionally, treatment with LPS caused approximately six- and three-fold increases in COX-2 mRNA and protein expression, respectively, compared to the controls. The LPS-induced elevations in the COX-2 mRNA and protein levels were suppressed by BTP2 to the control levels. In addition to its effect on COX-2, BTP2 also suppressed the LPS-induced productions of PGE2, IL-6, IL-8, and VEGF. Conversely, SOCE induction using Thapsigargin enhanced the LPS-induced inflammation, migration, and proliferation of breast cancer cells. Collectively, these results provide evidence for the potentially important role of SOCE in inflammation-induced breast cancer progression processes. Thus, we argue that the current study may provide novel targets for designing new therapeutic approaches for the treatment of breast cancer.

FYN/TOPK/HSPB1 axis facilitates the proliferation and metastasis of gastric cancer

BACKGROUND

FYN is a nonreceptor tyrosine kinase that regulates diverse pathological processes. The pro-cancer role of FYN in multiple malignancies has been elucidated. However, the mechanisms that FYN promotes gastric cancer (GC) progression remain largely unknown.

METHODS

In vitro and in vivo assays were used to investigate the function of FYN. FYN, TOPK, p-TOPK expression in GC specimens were detected by immunohistochemistry. Phosphoproteomics assays identify TOPK downstream substrate molecules. The molecular mechanism was determined using COIP assays, pull-down assays, immunofluorescence co-localization assays, western blotting, ³²p-labeled isotope radioautography assays, vitro kinase assays, and TOPK knockout mice.

RESULTS

FYN was found to be significantly upregulated in GC tissues as well as in GC cells. Knockdown of FYN expression markedly attenuated the malignant phenotype of GC cells in vitro and in vivo. Mechanistically, we identified TOPK/PBK as a novel downstream substrate of FYN, FYN directly phosphorylates TOPK at Y272. One phosphospecific antibodies against Y272 was developed to validate the phosphorylation of TOPK by FYN. Moreover, the TOPK-272F mutation impaired the interaction between TOPK and FYN, leading to disappeared TOPK phosphorylation. Consistently, human GC tissues displayed increased p-TOPK(Y272), which correlated with poor survival. Phosphoproteomics results showed a significant downregulation of both HSPB1 and p-HSPB1(ser15) in TOPK-knockdown cells, which was confirmed by TOPK-konckout mice.

CONCLUSIONS

FYN directly binds to TOPK in GC cells and phosphorylates TOPK at the Y272, which leads to proliferation and metastasis of GC. FYN-TOPK axis facilitates GC progression by phosphorylating HSPB1. Collectively, our study elucidates the pivotal role of the FYN-TOPK-HSPB1 cascade in GC.

Ferroptosis and triple-negative breast cancer: Potential therapeutic targets

Purpose

Triple-negative breast cancer (TNBC) is an aggressive tumor with poor prognosis, it has higher recurrence and metastatic rates than other breast cancer subtypes. This study aims to investigate biomarkers and potential targets for TNBC related to ferroptosis through data mining and bioinformatics analysis. The findings may provide new insights for treating TNBC.

Methods

The TNBC patients' data from the Cancer Genome Atlas (TCGA) database were extracted for differential expression and prognosis analysis. Consensus genes obtained by intersecting differential expressed and ferroptosis-related genes was used to establish the prognostic model by the univariate and multivariate Cox analyses. Besides, TNBC data from the Gene Expression Omnibus (GEO) database was used to confirm the reliability of the prognosis model. Moreover, clinical information was analyzed by multifactorial independent analysis to identify independent prognostic factors. The expression of genes constituting the prognostic model was further validated using the Human Protein Atlas (HPA) database. Finally, the Comparative Toxicogenomic Data (CTD) database was used to explore possible treatment drugs for TNBC.

Results

We obtained 13,245 differential expressed genes, and 177 consensus genes. 98 genes with prognostic implication were obtained by univariable Cox. Then, a prognostic model including 12 ferroptosis-related genes was constructed by multivariable Cox. The area under curve (AUC) value of the prognostic model for TNBC was 0.82. The GEO database validated that the model (AUC = 0.77) could predict the patient outcomes. The staining results of 10 out of 12 prognostic model genes in HPA database showed that their expression was consistent with our predictions. Clinical risk analysis indicated that risk score of patients could act as an independent prognostic factor. Finally, six drugs that may have interaction with 12 ferroptosis-related genes were obtained using the CTD database.

Conclusion

The prognostic model composed of 12 ferroptosis-related genes could predict the prognosis of TNBC patients, and seven genes (ASNS, LAMP2, CAV1, DPP4, HELLS, TF, ZFP69B) could be potential new therapeutic targets for TNBC, and two drugs (1-methyl-3-isobutylxanthine, rosiglitazone) could act as potential therapeutic drugs for the treatment of TNBC.

PD-L1-Targeted Co-Delivery of Two Chemotherapeutics for Efficient Suppression of Skin Cancer Growth

To overcome the severe side effects of cancer chemotherapy, it is vital to develop targeting chemotherapeutic delivery systems with the potent inhibition of tumour growth, angiogenesis, invasion and migration at low drug dosages. For this purpose, we co-loaded a conventional antiworm drug, albendazole (ABZ), and a TOPK inhibitor, OTS964, into lipid-coated calcium phosphate (LCP) nanoparticles for skin cancer treatment. OTS- and ABZ-loaded LCP (OTS-ABZ-LCP) showed a synergistic cytotoxicity against skin cancer cells through their specific cancerous pathways, without obvious toxicity to healthy cell lines. Moreover, dual-targeting the programmed death ligand-1 (PD-L1) and folate receptor overexpressed on the surface of skin cancer cells completely suppressed the skin tumour growth at low doses of ABZ and OTS. In summary, ABZ and OTS co-loaded dual-targeting LCP NPs represent a promising platform with high potentials against complicated cancers where PD-L1/FA dual targeting appears as an effective approach for efficient and selective cancer therapy.

Global DNA Methylation Profiles in Peripheral Blood of WTC-Exposed Community Members with Breast Cancer

Breast cancer represents the most common cancer diagnosis among World Trade Center (WTC)-exposed community members, residents, and cleanup workers enrolled in the WTC Environmental Health Center (WTC EHC). The primary aims of this study were (1) to compare blood DNA methylation profiles of WTC-exposed community members with breast cancer and WTC-unexposed pre-diagnostic breast cancer blood samples, and (2) to compare the DNA methylation differences among the WTC EHC breast cancer cases and WTC-exposed cancer-free controls. Gene pathway enrichment analyses were further conducted. There were significant differences in DNA methylation between WTC-exposed breast cancer cases and unexposed prediagnostic breast cancer cases. The top differentially methylated genes were Intraflagellar Transport 74 (IFT74), WD repeat-containing protein 90 (WDR90), and Oncomodulin (OCM), which are commonly upregulated in tumors. Probes associated with established tumor suppressor genes (ATM, BRCA1, PALB2, and TP53) were hypermethylated among WTC-exposed breast cancer cases compared to the unexposed group. When comparing WTC EHC breast cancer cases vs. cancer-free controls, there appeared to be global hypomethylation among WTC-exposed breast cancer cases compared to exposed controls. Functional pathway analysis revealed enrichment of several gene pathways in WTC-exposed breast cancer cases including endocytosis, proteoglycans in cancer, regulation of actin cytoskeleton, axon guidance, focal adhesion, calcium signaling, cGMP-PKG signaling, mTOR, Hippo, and oxytocin signaling. The results suggest potential epigenetic links between WTC exposure and breast cancer in local community members enrolled in the WTC EHC program.

Discovery of novel paeonol-based derivatives against skin inflammation in vitro and in vivo

T-LAK-cell-originated protein kinase (TOPK), a novel member of the mitogen-activated protein kinase family, is considered an effective therapeutic target for skin inflammation. In this study, a series (A − D) of paeonol derivatives was designed and synthesised using a fragment growing approach, and their anti-inflammatory activities against lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 cells were tested. Among them, compound B12 yielded the best results (IC₅₀ = 2.14 μM) with low toxicity (IC₅₀ > 50 µM). Preliminary mechanistic studies indicated that this compound could inhibit the TOPK-p38/JNK signalling pathway and phosphorylate downstream related proteins. A murine psoriasis-like skin inflammation model was used to determine its therapeutic effect.

The role of T-LAK cell-originated protein kinase in targeted cancer therapy

Targeted therapy has gradually become the first-line clinical tumor therapy due to its high specificity and low rate of side effects. TOPK (T-LAK cell-originated protein kinase), a MAP kinase, is highly expressed in various tumor tissues, while it is rarely expressed in normal tissues, with the exceptions of testicular germ cells and some fetal tissues. It can promote cancer cell proliferation and migration and is also related to drug resistance. Therefore, TOPK is considered a good therapeutic target. Moreover, a number of studies have shown that targeting TOPK can inhibit the proliferation of cancer cells and promote their apoptosis. Here, we discussed the biological functions of TOPK in cancer and summarized its tumor-related signaling network and known TOPK inhibitors. Finally, the role of TOPK in targeted cancer therapy was concluded, and future research directions for TOPK were assessed.

TLR2 and TLR4 Signaling Pathways and Gastric Cancer: Insights from Transcriptomics and Sample Validation

Background

Pattern recognition receptors, especially toll-like receptors (TLRs), as the first line of defense for pathogen detection, were found to be associated with H.¬ pylori infection and gastric cancer (GC). However, the expression levels of TLRs, i.e. TLR2 and TLR4, as the main receptors sensed by H.¬ pylori, still remain largely ambiguous. We aimed to investigate the patterns of key transcripts of TLR2 and TLR4 in 100 GC transcriptome data. Additionally, we evaluated TLR2 and TLR4 gene expressions in gastric biopsies of Iranian GC patients, in order to validate RNA-seq outputs.

Methods

For this study, 100 runs of GC samples and controls were processed and analyzed using map read to reference. Differential gene expression method was used to distinguish between GC and normal samples in the expression of TLRs and other innate immune molecules. Also, using qRT-PCR assay, transcripts of TLRs molecules for 15 GC and 15 control samples were analyzed based on the analysis of variance and least significant differences.

Results

The results clearly showed that all signaling pathways molecules of TLR4, especially TLR4 (p = 0.019), NF-κB (p ¬= 0.047), IL-1β (p = 0.0096), and TNF-α (p = 0.048), were upregulated in a cancerous condition in different parts and at various stages of GC.

Conclusion

Our findings suggested that molecules involved in inflammation, including TLR4 and its related pro-inflammatory cytokines, may be responsible for the development and progression of GC. Accordingly, the control of H. pylori infection reduces inflammation in the gastric system and can play an important role in preventing gastrointestinal disorders.

Endotoxin Triggers Tumor Initiation Events in Nontumorigenic Breast Epithelial Cells and Enhances Invasion-Related Phenotype in Pretumorigenic and Tumorigenic Breast Epithelial Cells

Inflammation is associated with the development of several cancers, including breast cancer. However, the molecular mechanisms driving breast cancer initiation or enhancement by inflammation are yet to be deciphered. Hence, we opted to investigate the role of inflammation in initiating and enhancing tumor-like phenotypes in nontumorigenic, pretumorigenic, and tumorigenic breast epithelial cells. Noncytotoxic endotoxin (ET) concentrations capable of inducing an inflammatory phenotype were determined for the different cell lines. Results showed that short-term ET exposure upregulated matrix metalloproteinase-9 (MMP-9) activity in nontumorigenic mammary epithelial cells of mouse (SCp2) and human origins (HMT-3522 S1; S1) and upregulated inflammatory mediators including nitric oxide (NO) and interleukin 1-β in tumorigenic human breast cells (MDA-MB-231), all in a dose-dependent manner. Long-term ET treatment, but not short-term, triggered the migration of SCp2 cells, and proliferation and migration of tumorigenic human breast cells MCF-7 and MDA-MB-231. Both short- and long-term ET exposures preferentially enhanced the invasion of pretumorigenic S1-connexin 43 knockout (Cx43-KO S1) cells compared to their nontumorigenic S1 counterparts. Moreover, both ET exposures disrupted lumen formation and apicolateral distribution of β-catenin in 3D cultures of S1 cells. In conclusion, ET treatment at concentrations that elicited inflammatory phenotype triggered tumor initiation events in nontumorigenic and pretumorigenic breast cells, and increased tumorigenicity of breast cancer cells. Our findings highlight the role of inflammation in enhancing migration, invasion, and loss of normal 3D morphology and suggest that such inflammatory insults can "add injury" to pretumorigenic and tumorigenic breast epithelial cells.

TOPK: A new predictor of the therapeutic response to neoadjuvant chemotherapy and prognosis in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) has a high probability of relapse and poor overall survival. Neoadjuvant chemotherapy (NACT) is currently a routine treatment strategy for TNBC, but some patients do not respond well. T-LAK cell-originated protein kinase (TOPK) is highly expressed in breast cancer cells and contributes to cancer cell proliferation. The present study aimed to investigate the correlation of TOPK expression with NACT treatment response and prognosis in TNBC.

METHODS

We collected 66 pairs of TNBC samples before and after NACT with docetaxel+ epirubicin+ cyclophosphamide (TEC). The Miller-Payne (MP) system was used to assess the therapeutic response to NACT in TNBC patients.

RESULTS

Immunohistochemistry analysis showed that TNBC patients with high TOPK expression before NACT had a poor treatment response and a poor prognosis. The expression of TOPK after NACT was significantly higher than that before NACT in patients with MP grade 1-3. In contrast, patients with MP grade 4-5 had significantly lower TOPK expression after NACT than before NACT, and the expression change in Ki-67 in patients with MP grade 4-5 exhibited the same trend. Survival analysis revealed that patients with TNBC accompanied by elevated TOPK expression before NACT had a worse prognosis than those with lower TOPK expression.

CONCLUSION

TOPK may be a novel predictor for the therapeutic response to NACT and prognosis for patients with TNBC.

Lipopolysaccharide from the commensal microbiota of the breast enhances cancer growth: role of S100A7 and TLR4

The role of commensal bacterial microbiota in the pathogenesis of human malignancies has been a research field of incomparable progress in recent years. Although breast tissue is commonly assumed to be sterile, recent studies suggest that human breast tissue may contain a bacterial microbiota. In this study, we used an immune‐competent orthotopic breast cancer mouse model to explore the existence of a unique and independent bacterial microbiota in breast tumors. We observed some similarities in breast cancer microbiota with skin; however, breast tumor microbiota was mainly enriched with Gram‐negative bacteria, serving as a primary source of lipopolysaccharide (LPS). In addition, dextran sulfate sodium (DSS) treatment in late‐stage tumor lesions increased LPS levels in the breast tissue environment. We also discovered an increased expression of S100A7 and low level of TLR4 in late‐stage tumors with or without DSS as compared to early‐stage tumor lesions. The treatment of breast cancer cells with LPS increased the expression of S100A7 in breast cancer cells in vitro. Furthermore, S100A7 overexpression downregulated TLR4 and upregulated RAGE expression in breast cancer cells. Analysis of human breast cancer samples also highlighted the inverse correlation between S100A7 and TLR4 expression. Overall, these findings suggest that the commensal microbiota of breast tissue may enhance breast tumor burden through a novel LPS/S100A7/TLR4/RAGE signaling axis.

PBK/TOPK: An Effective Drug Target with Diverse Therapeutic Potential

Simple Summary

Cancer is a major public health problem worldwide, and addressing its morbidity, mortality, and prevalence is the first step towards appropriate control measures. Over the past several decades, many pharmacologists have worked to identify anti-cancer targets and drug development strategies. Within this timeframe, many natural compounds have been developed to inhibit cancer growth by targeting kinases, such as AKT, AURKA, and TOPK. Kinase assays and computer modeling are considered to be effective and powerful tools for target screening, as they can predict physical interactions between small molecules and their bio-molecular targets. In the present review, we summarize the inhibitors and compounds that target TOPK and describe its role in cancer progression. The extensive body of research that has investigated the contribution of TOPK to cancer suggests that it may be a promising target for cancer therapy.

Abstract

T-lymphokine-activated killer cell-originated protein kinase (TOPK, also known as PDZ-binding kinase or PBK) plays a crucial role in cell cycle regulation and mitotic progression. Abnormal overexpression or activation of TOPK has been observed in many cancers, including colorectal cancer, triple-negative breast cancer, and melanoma, and it is associated with increased development, dissemination, and poor clinical outcomes and prognosis in cancer. Moreover, TOPK phosphorylates p38, JNK, ERK, and AKT, which are involved in many cellular functions, and participates in the activation of multiple signaling pathways related to MAPK, PI3K/PTEN/AKT, and NOTCH1; thus, the direct or indirect interactions of TOPK make it a highly attractive yet elusive target for cancer therapy. Small molecule inhibitors targeting TOPK have shown great therapeutic potential in the treatment of cancer both in vitro and in vivo, even in combination with chemotherapy or radiotherapy. Therefore, targeting TOPK could be an important approach for cancer prevention and therapy. Thus, the purpose of the present review was to consider and analyze the role of TOPK as a drug target in cancer therapy and describe the recent findings related to its role in tumor development. Moreover, this review provides an overview of the current progress in the discovery and development of TOPK inhibitors, considering future clinical applications.

3-Deoxysappanchalcone Inhibits Skin Cancer Proliferation by Regulating T-Lymphokine-Activated Killer Cell-Originated Protein Kinase in vitro and in vivo

Background

Skin cancer is one of the most commonly diagnosed cancers worldwide. The 5-year survival rate of the most aggressive late-stage skin cancer ranges between 20 and 30%. Thus, the discovery and investigation of novel target therapeutic agents that can effectively treat skin cancer is of the utmost importance. The T-lymphokine-activated killer cell-originated protein kinase (TOPK), which belongs to the serine-threonine kinase class of the mitogen-activated protein kinase kinase (MAPKK) family, is highly expressed and activated in skin cancer. The present study investigates the role of 3-deoxysappanchalcone (3-DSC), a plant-derived functional TOPK inhibitor, in suppressing skin cancer cell growth.

Purpose

In the context of skin cancer prevention and therapy, we clarify the effect and mechanism of 3-DSC on different types of skin cancer and solar-simulated light (SSL)-induced skin hyperplasia.

Methods

In an in vitro study, western blotting and in vitro kinase assays were utilized to determine the protein expression of TOPK and its activity, respectively. Pull-down assay with 3-DSC and TOPK (wild-type and T42A/N172 mutation) was performed to confirm the direct interaction between T42A/N172 amino acid sites of TOPK and 3-DSC. Cell proliferation and anchorage-independent cell growth assays were utilized to determine the effect of 3-DSC on cell growth. In an in vivo study, the thickness of skin and tumor size were measured in the acute SSL-induced inflammation mouse model or SK-MEL-2 cell-derived xenografts mouse model treated with 3-DSC. Immunohistochemistry analysis of tumors isolated from SK-MEL-2 cell-derived xenografts was performed to determine whether cell-based results observed upon 3-DSC treatment could be recapitulated in vivo.

Results

3-DSC is able to inhibit cell proliferation in skin cancer cells in an anchorage-dependent and anchorage-independent manner by regulation of TOPK and its related signaling pathway in vitro. We also found that application of 3-DSC reduced acute SSL-induced murine skin hyperplasia. Additionally, we observed that 3-DSC decreased SK-MEL-2 cell-derived xenograft tumor growth through attenuating phosphorylation of TOPK and its downstream effectors including ERK, RSK, and c-Jun.

Conclusions

Our results suggest that 3-DSC may function in a chemopreventive and chemotherapeutic capacity by protecting against UV-induced skin hyperplasia and inhibiting tumor cell growth by attenuating TOPK signaling, respectively.

Scutellarin Suppresses RPMI7951 Melanoma Cell Proliferation by Targeting TOPK

BACKGROUND

T-LAK cell-Originated Protein Kinase (TOPK) belongs to the serine/threonine protein kinase family. It is highly expressed in RPMI7951 melanoma cells. Scutellarin (SCU) is an active ingredient extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. Its main physiological functions are related to its anti-inflammatory and antitumour activities.

METHODS

The relationship between SCU and TOPK was assessed by molecular docking, an in vitro binding assay and an in vitro kinase assay. The effect of SCU on RPMI7951 cells was detected by MTS and soft agar assays. TOPK knockdown was induced by lentiviral infection. The TOPK downstream signalling pathway was detected by western blot and immunohistochemical analyses in vitro and in vivo.

RESULTS

SCU was found to directly bind with TOPK and inhibit TOPK activity in vitro. SCU inhibited the proliferation and colony formation of RPMI7951 cells in a dose-dependent manner. Silencing TOPK decreased the sensitivity of colon cancer cells to SCU. SCU inhibited the phosphorylation levels of Extracellular Regulated protein Kinases 1/2 (ERK1/2) and histone H3 in a time- and dose-dependent manner in RPMI7951 cells. In addition, SCU inhibited the growth of xenograft tumours of RPMI7951 cells and decreased the phosphorylation levels of extracellular regulated protein kinases 1/2 and histone H3 in vivo.

CONCLUSION

The results showed that SCU exerts promising antitumour effects on human RPMI7951 cells by inhibiting the activity of TOPK.

TOPK mediates hypoxia-induced epithelial-mesenchymal transition and the invasion of nonsmall-cell lung cancer cells via the HIF-1α/snail axis

Hypoxia has been suggested to induce epithelial-mesenchymal transition (EMT) in various cancer types via the transcription factor hypoxia-inducible factor-1 alpha (HIF-1α). Here, we demonstrated that TOPK upregulates EMT and the invasion of H460 nonsmall-cell lung cancer cells through the induction of the HIF-1α/Snail axis and hypoxic signaling. The expression of endogenous TOPK, phosphorylated TOPK, HIF-1α and Snail was significantly increased upon hypoxia exposure, but TOPK depletion markedly abrogated the induced mRNA and protein levels of HIF-1α and Snail. Interestingly, TOPK knockdown restored the hypoxia-induced suppression of E-cadherin and diminished hypoxia-induced N-cadherin expression. In addition, Snail depletion suppressed hypoxia-induced N-cadherin expression, which was attenuated by TOPK knockdown. Moreover, knockdown of Snail decreased hypoxia-induced nonsmall-cell lung cancer cell migration and invasion, which were suppressed by TOPK depletion. In summary, we conclude that TOPK positively regulates HIF-1α expression through hypoxia signaling and thereby promotes Snail expression, leading to EMT and the invasion of nonsmall-cell lung cancer cells. These findings suggest that TOPK plays a critical role as a novel mediator of hypoxia signaling that regulates nonsmall-cell lung cancer development.

Activation of NF-κB by TOPK upregulates Snail/Slug expression in TGF-β1 signaling to induce epithelial-mesenchymal transition and invasion of breast cancer cells

TGF-β1 is known to induce epithelial-mesenchymal transition (EMT), which is a prerequisite for cancer cell invasion. Here we reveal that TOPK upregulates EMT and invasion of human breast cancer MDA-MB-231 or Hs578T cells via NF-κB-dependent Snail/Slug in TGF-β1 signaling. Endogenous TOPK expression was significantly increased in response to TGF-β1 and TOPK knockdown mitigated TGF-β1-induced breast cancer cell invasion. Interestingly, TOPK knockdown restored TGF-β1 suppression of E-cadherin expression and markedly reduced N-cadherin induced by TGF-β1. Also, NF-κB activity or expression of EMT markers Snail and Slug induced by TGF-β1 was decreased by TOPK knockdown. Meanwhile, knockdown of Snail or TOPK attenuated TGF-β1-induced breast cancer cell invasion. Taken, we conclude that TOPK mediates TGF-β1-induced EMT and invasion in breast cancer cells via NF-κB/Snail signaling, suggesting novel role of TOPK as therapeutic target in TGF-β1-mediated breast cancer development.

TOPK promotes epithelial-mesenchymal transition and invasion of breast cancer cells through upregulation of TBX3 in TGF-β1/Smad signaling

TOPK has been suggested to contribute to invasion of lung, prostate, gastric, pancreatic or breast cancer cells. However, how TOPK mediates TGF-β1/Smad signaling leading to epithelial-mesenchymal transition (EMT) and invasion of breast cancer cells remains unknown. Here we report that TOPK upregulates T-box transcription factor TBX3 to enhance TGF-β1-induced EMT and invasion of MDA-MB-231 breast cancer cells. Expression of endogenous TOPK was promoted by TGF-β1 treatment of MDA-MB-231 cells time-dependently. In addition, knockdown of TOPK attenuated TGF-β1-induced phosphorylation or transcriptional activity of Smad3. Meanwhile, levels of both mRNA and protein of TBX3 induced by TGF-β1 were abolished by TOPK depletion. Also, knockdown of TBX3 inhibited TGF-β1 induction of EMT-related genes Snail, Slug or Fibronectin. Furthermore, ablation of TOPK or TBX3 suppressed TGF-β1-induced MDA-MB-231 cell invasion. Collectively, we conclude that TOPK positively regulates TBX3 in TGF-β1/Smad signaling pathway, thereby enhancing EMT and invasion of breast cancer cells, implying a mechanistic role of TOPK in TGF-β1/Smad signaling.

Silibinin inhibits migration and invasion of breast cancer MDA-MB-231 cells through induction of mitochondrial fusion

Human triple negative breast cancer cells, MDA-MB-231, show typical epithelial to mesenchymal transition associated with cancer progression. Mitochondria play a major role in cancer progression, including metastasis. Changes in mitochondrial architecture affect cellular migration, autophagy and apoptosis. Silibinin is reported to have anti-breast cancer effect. We here report that silibinin at lower concentrations (30-90 μM) inhibits epithelial to mesenchymal transition (EMT) of MDA-MB-231, by increasing the expression of epithelial marker, E-cadherin, and decreasing the expression of mesenchymal markers, N-cadherin and vimentin. Besides, silibinin inhibition of cell migration is associated with reduction in the protein expression of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) and paxillin. In addition, silibinin treatment increases mitochondrial fusion through down-regulating the expression of mitochondrial fission-associated protein dynamin-related protein 1 (DRP1) and up-regulating the expression of mitochondrial fusion-associated proteins, optic atrophy 1, mitofusin 1 and mitofusin 2. Silibinin perturbed mitochondrial biogenesis via down-regulating the levels of mitochondrial biogenesis regulators including mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor gamma coactivator (PGC1) and nuclear respiratory factor (NRF2). Moreover, DRP1 knockdown or silibinin inhibited cell migration, and MFN1&2 knockdown restored it. Mitochondrial fusion contributes to silibinin's negative effect on cell migration. Silibinin decreased reactive oxygen species (ROS) generation, leading to inhibition of the NLRP3 inflammasome activation. In addition, knockdown of mitofusin 1&2 (MFN 1&2) relieved silibinin-induced inhibition of NLRP3 inflammasome activation. Repression of ROS contributes to the inhibition of the expression of NLRP3, caspase-1 and IL-β proteins as well as of cell migration. Taken together, our study provides evidence that silibinin impairs mitochondrial dynamics and biogenesis, resulting in reduced migration and invasion of the MDA-MB-231 breast cancer cells.

Surface modification of silver nanoparticle (AgNP) by liposomal encapsulation mitigates AgNP-induced inflammation

Silver nanoparticles (AgNP) are widely used in a variety of consumable products as antibacterial to prevent or treat infection. Unfortunately, evidence exits that AgNP induces inflammation which can worsen with repeated human exposure. However, there is little or no research on how to mitigate these adverse effects due to AgNP induced-toxicity. Here, we investigated if surface modification of AgNP by liposomal encapsulation suppresses AgNP-mediated inflammatory responses in THP1 monocytes and THP1 differentiated macrophages (TDM). AgNP was encapsulated in a dipalmitoyl phosphatidyl choline- (DPPC)/cholesterol-based liposome by extrusion through a 100-nm polycarbonate membrane to form Lipo-AgNP. It was found as expected that AgNP induced significant release of IL-1β, IL-6, IL-8 and TNF-α in THP1 monocytes more than the basal level. Interestingly, release of these cytokines was suppressed by Lipo-AgNP. In TDMs, AgNP and Lipo-AgNP induced IL-8 release (p < .0001), but Lipo-AgNP maintained IL-8 release at levels significantly lower than that of AgNP (p < .01). However, both AgNP and Lipo-AgNP suppressed IL-1β and TNF-α release in LPS-stimulated THP1 monocytes and LPS-stimulated or unstimulated TDM respectively. We finally showed that Lipo-AgNP inhibits STAT-3 and this may be responsible for regulating the uncontrolled inflammation induced by AgNP likely mediated STAT-3 protein expression in LPS stimulated THP1 monocytes and TDMs, both LPS-stimulated and unstimulated. This data showed that Lipo-AgNP suppressed AgNP induced inflammation, making Lipo-AgNP particularly useful in treatment of bacteria induced inflammatory diseases and inflammatory cancers.

Glycyrol exerts potent therapeutic effect on lung cancer via directly inactivating T-LAK cell-originated protein kinase

Molecular targeted therapy for non-small cell lung cancer (NSCLC) has demonstrated promising outcomes. T-lymphokine-activated killer cell-originated protein kinase (TOPK) is found overexpressed in many cancer types such as NSCLC, and is considered to be an effective target for lung cancer treatment. In the present study, we found that glycyrol (GC), a representative coumarin compound isolated from licorice, was highly effective against several human NSCLC cell lines in vitro, and significantly suppressed tumor growth in vivo. Mechanistically, we demonstrated that GC can strongly bind to the TOPK protein and inhibited its kinase activity, leading to the activation of apoptotic signaling pathways. The findings of the present study suggest that GC is a novel promising TOPK inhibitor and this compound deserves to be further investigated for its potential anti-NSCLC activity.

Knockdown of Delta-like 3 restricts lipopolysaccharide-induced inflammation, migration and invasion of A2058 melanoma cells via blocking Twist1-mediated epithelial-mesenchymal transition

AIMS

To investigate the effects and mechanisms of DLL3 in inflammation-mediated A2058 melanoma cell invasion and metastasis.

MATERIALS AND METHODS

Melanoma A2058 cells was stimulated with lipopolysaccharide (LPS), with or without transfection of DLL3 siRNA, or DLL3 overexpression vector, or Twist1 siRNA. Cell migration and invasion were detected by wound healing and transwell invasion assay. The production of inflammatory factors TNF-α and IL-6 was measured by ELISA. The expression of Notch signaling-related molecules was detected by PCR and western blot. The protein expression of MMP1, MMP9, VEGF, DLL3, and EMT-related molecules was tested by western blot.

KEY FINDINGS

LPS treatment increased migration and invasion of A2058 cells, accompanied by increased expression of TNF-α and IL-6. DLL3 was both upregulated in the LPS- or TNF-α-stimulated A2058 cells, and DLL3 knockdown inhibited LPS-induced inflammation, migration and invasion of A2058 cells, accompanied by down-regulation of MMP1, MMP9 and VEGF. Besides, DLL3 knockdown inhibits the expression of Twist1, a key EMT regulating factor, as well as the EMT hallmarks slug, N-cadherin and vimentin. Moreover, Twist1 silence inhibited EMT, and limited LPS-induced migration and invasion of A2058 cells, with decreased expression of MMP1, MMP9 and VEGF and reduced production of TNF-α and IL-6 in LPS-stimulated A2058 cells.

SIGNIFICANCE

Knockdown of DLL3 restricts LPS-induced inflammation, migration and invasion of A2058 melanoma cells via blocking Twist1-mediated EMT. Therefore, targeting DLL3 may be a promising therapeutic strategy against inflammation-aggravated melanoma progression.

Baicalin suppresses lung cancer growth by targeting PDZ-binding kinase/T-LAK cell-originated protein kinase

Baicalin is the main bioactive component extracted from the traditional Chinese medicine Baical Skullcap Root, and its anti-tumor activity has been studied in previous studies. PDZ-binding kinase/T-LAK cell-originated protein kinase (PBK/TOPK), a serine/threonine protein kinase, is highly expressed in many cancer cells and stimulates the tumorigenic properties, and so, it is a pivotal target for agent to cure cancers. We reported for the first time that baicalin suppressed PBK/TOPK activities by directly binding with PBK/TOPK in vitro and in vivo. Ex vivo studies showed that baicalin suppressed PBK/TOPK activity in JB6 Cl41 cells and H441 lung cancer cells. Moreover, knockdown of PBK/TOPK in H441 cells decreased their sensitivity to baicalin. In vivo study indicated that injection of baicalin in H441 tumor-bearing mice effectively suppressed cancer growth. The PBK/TOPK downstream signaling molecules Histone H3 and ERK2 in tumor tissues were also decreased after baicalin treatment. Taken together, baicalin can inhibit proliferation of lung cancer cells as a PBK/TOPK inhibitor both in vitro and in vivo.

Down-regulation of MRPS23 inhibits LPS-induced proliferation and invasion via regulation of the NF-κB signaling pathway in osteosarcoma cells

Mitochondrial ribosomal protein S23 (MRPS23), encoded by a nuclear gene, is a participant in the translation of mitochondrial proteins. Recently, MRPS23 has been reported to be overexpressed in many types of cancers and have a close association with cancer progression. However, the specific roles of MRPS23 in osteosarcoma (OS) remain unknown. In this study, we investigated the expression pattern and biological functions of MRPS23 in OS cells. Our results demonstrated that MRPS23 was up-regulated in OS tissues and cell lines. Down-regulation of MRPS23 significantly inhibited OS cell proliferation and invasion induced by lipopolysaccharide (LPS) in vitro. Furthermore, the in vivo experiments showed that MRPS23 down-regulation markedly suppressed OS cell growth and metastasis induced by LPS. Mechanistically, down-regulation of MRPS23 inhibited the activity of NF-κB signaling pathway in OS cells. In conclusion, these findings indicated that MRPS23 may be a potential therapeutic target for OS treatment.

Mitochondrial ribosomal protein S23 (MRPS23), encoded by a nuclear gene, is a participant in the translation of mitochondrial proteins.

SSRP1 promotes colorectal cancer progression and is negatively regulated by miR-28-5p

In this study, microarray data analysis, real‐time quantitative PCR and immunohistochemistry were used to detect the expression levels of SSRP1 in colorectal cancer (CRC) tissue and in corresponding normal tissue. The association between structure‐specific recognition protein 1 (SSRP1) expression and patient prognosis was examined by Kaplan‐Meier analysis. SSRP1 was knocked down and overexpressed in CRC cell lines, and its effects on proliferation, cell cycling, migration, invasion, cellular energy metabolism, apoptosis, chemotherapeutic drug sensitivity and cell phenotype‐related molecules were assessed. The growth of xenograft tumours in nude mice was also assessed. MiRNAs that potentially targeted SSRP1 were determined by bioinformatic analysis, Western blotting and luciferase reporter assays. We showed that SSRP1 mRNA levels were significantly increased in CRC tissue. We also confirmed that this upregulation was related to the terminal tumour stage in CRC patients, and high expression levels of SSRP1 predicted shorter disease‐free survival and faster relapse. We also found that SSRP1 modulated proliferation, metastasis, cellular energy metabolism and the epithelial‐mesenchymal transition in CRC. Furthermore, SSRP1 induced apoptosis and SSRP1 knockdown augmented the sensitivity of CRC cells to 5‐fluorouracil and cisplatin. Moreover, we explored the molecular mechanisms accounting for the dysregulation of SSRP1 in CRC and identified microRNA‐28‐5p (miR‐28‐5p) as a direct upstream regulator of SSRP1. We concluded that SSRP1 promotes CRC progression and is negatively regulated by miR‐28‐5p.

Lipopolysaccharide (LPS) enhances prostate cancer metastasis potentially through NF-κB activation and recurrent dexamethasone administration fails to suppress it in vivo

BACKGROUND

Previous studies have shown the effect of bacterial lipopolysaccharide (LPS) on enhanced cancer cells' growth and metastasis. However, the effect of LPS on prostate cancer (PCa) cells metastasis has not been investigated in details. This study aimed to investigate the functional role of LPS on PCa cells metastasis and determine the effect of dexamethasone (DEX) on this event.

METHODS

Two different PCa reporter cells lines (DU145-NF-κB-Luc and MAT-LyLu- NF-κB-Luc) were used to assess the direct effect of LPS on NF-κB activation in PCa cells. Plasma collected from LPS-stimulated human and rodent blood were used to check the indirect effect of LPS on NF-κB activation in PCa cells. Trans-well migration assay and two different orthotopic PCa animal models were used to investigate the effect of LPS on DU145 and MAT-LyLu cells migration or metastasis in vitro and in vivo, respectively. In all the studies DEX was used with or without LPS stimulation.

RESULTS

LPS and secretory factors present in plasma collected from LPS-stimulated blood, significantly activated NF-κB in DU145, and MAT-LyLu cells and enhanced their migration in vitro. DEX significantly suppressed LPS-mediated activation of cancer and blood cells and abrogated the direct and indirect pro-migratory effect of LPS on PCa cells. Systemic administration of LPS activated NF-κB in DU145 cells in vivo; however, failed to alter the metastatic properties of these cells. On the other hand, systemic administration of LPS to MAT-LyLu tumor bearing animals significantly enhanced the incidence of metastasis without altering the overall growth of primary tumors. Unexpectedly, though DEX significantly suppressed MAT-LyLu primary tumor weights, it aggravated metastasis of cancer cells in presence and absence of LPS. Moreover, consecutive DEX pre-treatment enhanced experimental peritoneal metastasis of MAT-LyLu cells. At the molecular level, LPS, and/or DEX induced overexpression of immunosuppressive molecules in MAT-LyLu tumors.

CONCLUSIONS

Overall, our study has shown that LPS and/or LPS induced inflammation can increase PCa metastasis and immunosuppressive dose of DEX might further enhance cancer metastasis.

LPS-induced CXCR7 expression promotes gastric Cancer proliferation and migration via the TLR4/MD-2 pathway

BACKGROUND

Lipopolysaccharide (LPS) from Helicobacter pylori (HP) plays an important role in gastric cancer occurrence and development. Toll-like receptor 4 (TLR4) and myeloid differential protein-2 (MD-2) are also reported to be involved in gastric cancer cell proliferation and invasion. CXC chemokine receptor 7 (CXCR7), a second receptor for CXCL12, has been detected in multiple types of tumor tissues. Nevertheless, the biological function and regulation of CXCR7 and its relationship with TLR4 and MD-2 in gastric cancer are not completely understood and therefore warrant further study.

METHODS

CXCR7 expression was examined in 150 gastric cancer tissues using immunohistochemistry (IHC). RT-PCR and western blotting were used to detect CXCR7 expression in several gastric cancer cell lines (SGC7901, AGS, MGC-803, MKN-45 and BGC823). shRNAs were designed using a pGPU6/GFP/Neo vector. A CCK-8 assay was used to assess cell proliferation, and transwell assays were performed to assess cell migration. In addition, a gastric cancer xenograft model was generated.

RESULTS

The LPS-TLR4-MD-2 pathway elevates CXCR7 expression in SGC7901 cells, and TLR4/MD-2-mediated increases in CXCR7 levels modulate the proliferation and migration of tumor cells. Knockdown of TLR4 and MD-2 demonstrated that both are essential for LPS-induced CXCR7 expression, which in turn is responsible for LPS-induced SGC7901 cell proliferation and migration. Moreover, higher TLR4, MD-2 and CXCR7 expression was detected in gastric cancer tissues than in paracancerous normal control tissues. The expression levels of TLR4, MD-2 and CXCR7 were closely related to gastric cancer TNM stage and lymph node metastasis. In an animal model, significant differences in CXCR7 expression in tumor masses were observed between the control group and experimental group.

CONCLUSIONS

The results of this study indicate that CXCR7 plays an important role in gastric cancer progression via inflammatory mechanisms, suggesting that CXCR7 could provide a basis for the development and clinical application of a targeted drug for gastric cancer.

Prognostic Value of PDZ-Binding Kinase/T-LAK Cell-Originated Protein Kinase (PBK/TOPK) in Patients with Cancer

Background: PDZ-binding kinase/T-LAK cell-originated protein kinase (PBK/TOPK) plays a critical role in tumorigenesis and cancer progression. However, the prognostic roles in cancer patients are inconsistent or even controversial. Therefore, we performed a meta-analysis to investigate the prognostic value of PBK/TOPK in cancers.

Methods: Literature search was performed using several online databases (PubMed, Web of Science, Embase, Cochrane Library, and Google Scholar, National Knowledge Infrastructure and Wanfang) for eligible articles published up to May 1, 2018. The relationship between PBK/TOPK expression and prognosis in cancers was investigated by using pooled hazard ratios (HRs) with 95% confidence intervals (CIs) through STATA 12.0 software.

Results: Totally 20 eligible studies were included in this meta-analysis. The pooled results showed that carriers with high protein expression of PBK/TOPK were significantly associated with poor OS (HR: 1.69, 95% CI: 1.33-2.04) in various cancers, and patients with increased PBK/TOPK protein expression were significantly correlated with inferior RFS (HR: 1.63, 95% CI: 1.02-2.24) and short DFS (HR: 1.69, 95% CI: 1.16-2.23).

Conclusions: The findings suggest that PBK/TOPK protein expression might serve as a prognostic tumor marker in cancers.

T-lymphokine-activated killer cell-originated protein kinase (TOPK) as a prognostic factor and a potential therapeutic target in glioma

TOPK is overexpressed in various types of cancer and associated with poor outcomes in different types of cancer. In this study, we first found that the expression of T-lymphokine-activated killer cell-originated protein kinase (TOPK) was significantly higher in Grade III or Grade IV than that in Grade II in glioma (P = 0.007 and P < 0.001, respectively). Expression of TOPK was positively correlated with Ki67 (P < 0.001). Knockdown of TOPK significantly inhibited cell growth, colony formation and increased sensitivities to temozolomide (TMZ) in U-87 MG or U-251 cells, while TOPK overexpression promoted cell growth and colony formation in Hs 683 or A-172 cells. Glioma patients expressing high levels of TOPK have poor survival compared with those expressing low levels of TOPK in high-grade or low-grade gliomas (hazard ratio = 0.2995; 95% CI, 0.1262 to 0.7108; P = 0.0063 and hazard ratio = 0.1509; 95% CI, 0.05928 to 0.3842; P < 0.0001, respectively). The level of TOPK was low in TMZ-sensitive patients compared with TMZ-resistant patients (P = 0.0056). In TMZ-resistant population, patients expressing high TOPK have two months’ shorter survival time than those expressing low TOPK. Our findings demonstrated that TOPK might represent as a promising prognostic and predictive factor and potential therapeutic target for glioma.

Di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), an anticancer agent, exerts an anti-inflammatory effect in activated human mast cells

OBJECTIVE

Inflammation has been closely associated with the development and progression of cancer. Previously, we reported that mast cells play a critical role in tumor growth. The purpose of this study is to investigate the anti-inflammatory effect of an anticancer agent, di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), on an activated human mast cell line, in this case HMC-1 cells.

METHODS

We evaluated the effect and specific molecular mechanism of Dp44mT on phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI) using HMC-1 cells.

RESULTS

Here, we demonstrated that Dp44mT significantly decreased the protein levels of hypoxia-inducible factor-1α and vascular endothelial growth factor without exposing activated HMC-1 cells to any cytotoxicity. In activated mast cells, Dp44mT mitigated the strong production and mRNA expression of inflammatory cytokines, in this case, interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and thymic stromal lymphopoietin, through a blockade of caspase-1 and nuclear factor-κB activities. Furthermore, phosphorylations of the mitogen-activated protein kinase family included in inflammatory signaling cascades were significantly inhibited by a Dp44mT treatment.

CONCLUSIONS

Overall, our results indicate that the anticancer agent Dp44mT has an anti-inflammatory effect and may be of therapeutic importance for the treatment of mast cell-mediated inflammatory diseases.