The Traf2 and NcK interacting kinase inhibitor NCB-0846 suppresses seizure activity involving the decrease of GRIA1.

Epilepsy, one of the most common neurological disorders, is characterized by spontaneous recurrent seizures. Temporal lobe epilepsy (TLE) is one of the most common medically intractable seizure disorders. Traf2-and NcK-interacting kinase (TNIK) has recently attracted attention as a critical modulation target of many neurological and psychiatric disorders, but its role in epilepsy remains unclear. In this study, we hypothesized the involvement of TNIK in epilepsy and investigated TNIK expression in patients with intractable TLE and in a pilocarpine-induced rat model of epilepsy by western blotting, immunofluorescence, and immunohistochemistry. A pentylenetetrazole (PTZ)-induced epilepsy rat model was used to determine the effect of the TNIK inhibitor NCB-0846 on behavioral manifestations of epilepsy. Coimmunoprecipitation (Co-IP)/mass spectrometry (MS) was used to identify the potential mechanism. Through Co-IP, we detected and confirmed the main potential TNIK interactors. Subcellular fractionation was used to establish the effect of NCB-0846 on the expression of the main interactors in postsynaptic density (PSD) fractions. We found that TNIK was primarily located in neurons and decreased significantly in epilepsy model rats and TLE patients compared with controls. NCB-0846 delayed kindling progression and decreased seizure severity. Co-IP/MS identified 63 candidate TNIK interactors in rat hippocampi, notably CaMKII. Co-IP showed that TNIK might correlate with endogenous GRIA1, SYN2, PSD-95, CaMKIV, GABRG1, and GABRG2. In addition, the significant decrease in GRIA1 in hippocampal total lysate and PSDs after NCB-0846 treatment might help modify the progression of PTZ kindling. Our results suggest that TNIK contributes to epileptic pathology and is a potential antiepileptic drug target.

The Apelin/APJ system modulates seizure activity and endocytosis of the NMDA receptor GluN2B subunit.

In the central nervous system (CNS), the apelin/APJ system is broadly expressed. According to some studies, activation of this system protects against excitotoxicity mediated by N-methyl-D-aspartate (NMDA) receptors and exerts neuroprotective effects. However, the role of this system in epilepsy remains unclear. In the present study, immunofluorescence staining and western blotting were used to assess APJ localization and expression in the brains of mice with recurrent spontaneous seizures induced by kainic acid (KA). Behavior and local field potentials (LFPs) were assessed in mice with KA-induced seizures. Susceptibility to seizures was assessed in a pentylenetetrazole (PTZ)-induced seizure model. Whole-cell patch-clamp recordings were used to evaluate the role of the apelin/APJ system in regulating synaptic transmission in brain slices from mice in which Mg2+-free medium was used to induce seizures. NMDA receptor GluN2B subunit expression and phosphorylation of GluN2B at Ser1480 were measured in the mouse hippocampus. APJ was primarily localized in neurons, and its expression was upregulated in the epileptic brain. APJ activation after KA-induced status epilepticus (SE) reduced epileptic activity, whereas APJ inhibition aggravated epileptic activity. In the PTZ model, APJ activation reduced and APJ inhibition increased susceptibility to seizures. The apelin/APJ system affected NMDA receptor-mediated postsynaptic currents in patch-clamp recordings. Moreover, APJ regulated the levels of GluN2B phosphorylated at Ser1480 and the abundance of cell-surface GluN2B in neurons. Furthermore, endocytosis of the NMDA receptor GluN2B subunit was regulated by the apelin/APJ system. Together, our findings indicate that the apelin/APJ system modulates seizure activity and may be a novel therapeutic target for epilepsy.

Levetiracetam induces severe psychiatric symptoms in people with epilepsy.

BACKGROUND: Drug-induced psychiatric symptoms are an important cause of treatment failure. Worldwide, levetiracetam has been widely used to treat epilepsy; however, associated psychobehavioral abnormalities have been observed . This study aimed to characterize levetiracetam-induced severe psychiatric symptoms and to propose preventive and therapeutic measures. METHODS: In this retrospective cluster sampling study, psychiatric symptoms of patients who had taken levetiracetam for at least 1 month were analyzed. RESULTS: 111(7.8%) of the 1,412 included patients exhibited severe psychiatric symptoms. Hallucinations, delusions, aggressive behavior, and agitation were the most common manifestations . Some patients also showed suicidal and self-harm behaviors. These symptoms were mainly controlled by reducing the dose of levetiracetam, stopping the drug, or adding antipsychotic drugs to the treatment regimen. CONCLUSION: The severe psychiatric symptoms caused by levetiracetam require special attention.

Beclin1 Deficiency Suppresses Epileptic Seizures.

Epilepsy is a common disease of the nervous system. Autophagy is a degradation process involved in epilepsy, and in turn, seizures can activate autophagy. Beclin1 plays a critical role in autophagy and participates in numerous physiological and pathological processes. However, the mechanism underlying the effect of Beclin1 on epilepsy remains unclear. In this study, we detected increased expression of Beclin1 in brain tissues from patients with temporal lobe epilepsy (TLE). Heterozygous disruption of beclin1 decreased susceptibility to epilepsy and suppressed seizure activity in two mouse epilepsy models. We further illustrated for the first time that heterozygous disruption of beclin1 suppresses excitatory synaptic transmission, which may be caused by a decreased dendritic spine density. These findings suggest for the first time that the regulation of Beclin1 may serve as a strategy for antiepileptic therapy. In addition, Beclin1 participates in synaptic transmission, and the development of dendritic spines may be a biological function of Beclin1 independent of its role in autophagy.

Smoke-induced SAV1 Gene Promoter Hypermethylation Disrupts YAP Negative Feedback and Promotes Malignant Progression of Non-small Cell Lung Cancer.

YAP (gene symbol YAP1) as a potential oncoprotein, is positively correlated with the malignancy of various tumors. However, overexpression of YAP alone in multiple normal tissue cells has failed to induce tumor formation and the underlying mechanism is poorly understood. Herein, we show that YAP activation directly induces transcription of its negative regulator, SAV1, to constitute a negative feedback loop, which plays a vital role in maintaining lung epithelial cell homeostasis and was dysregulated in non-small cell lung cancer (NSCLC). Notably, smoking promotes the hypermethylation of the SAV1 promoter region, which disrupts YAP negative feedback by inactivating the Hippo pathway. Besides, exogenous overexpression of SAV1 can act as a traffic protein, activating the Hippo signaling and concurrently inhibiting the WNT pathway to decrease cancer cell growth. Furthermore, using the lung cancer organoids, we found that lentivirus-mediated SAV1 gene transfer combined with methylation inhibitor and YAP-TEAD inhibitor is a potential feasible clinical medication regimen for the lung cancer patient, especially among the smoking population. Thus, this SAV1 mediated feedback loop provides an efficient mechanism to establish the robustness and homeostasis of YAP regulation and as a potential target of gene therapy for the smoking NSCLC population.

SAPAP3 regulates epileptic seizures involving GluN2A in post-synaptic densities.

Aberrantly synchronized neuronal discharges in the brain lead to epilepsy, a devastating neurological disease whose pathogenesis and mechanism are unclear. SAPAP3, a cytoskeletal protein expressed at high levels in the postsynaptic density (PSD) of excitatory synapses, has been well studied in the striatum, but the role of SAPAP3 in epilepsy remains elusive. In this study, we sought to investigate the molecular, cellular, electrophysiological and behavioral consequences of SAPAP3 perturbations in the mouse hippocampus. We identified a significant increase in the SAPAP3 levels in patients with temporal lobe epilepsy (TLE) and in mouse models of epilepsy. In addition, behavioral studies showed that the downregulation of SAPAP3 by shRNA decreased the seizure severity and that the overexpression of SAPAP3 by recombinant SAPAP3 yielded the opposite effect. Moreover, SAPAP3 affected action potentials (APs), miniature excitatory postsynaptic currents (mEPSCs) and N-methyl-D-aspartate receptor (NMDAR)-mediated currents in the CA1 region, which indicated that SAPAP3 plays an important role in excitatory synaptic transmission. Additionally, the levels of the GluN2A protein, which is involved in synaptic function, were perturbed in the hippocampal PSD, and this perturbation was accompanied by ultrastructural morphological changes. These results revealed a previously unknown function of SAPAP3 in epileptogenesis and showed that SAPAP3 may represent a novel target for the treatment of epilepsy.

TCRP1 activated by mutant p53 promotes NSCLC proliferation via inhibiting FOXO3a.

Previously, our lab explored that tongue cancer resistance-associated protein (TCRP1) plays a central role in cancer chemo-resistance and progression. Absolutely, TCRP1 was significantly increased in lung cancer. But the mechanism is far from elucidated. Here, we found that TCRP1 was increased in p53-mutant non-small-cell lung cancer (NSCLC), comparing to that in NSCLC with wild type p53. Further study showed that mutant p53 couldn't bind to the promoter of TCRP1 to inhibit its expression. While the wild type p53 did so. Next, loss-and gain-of-function assays demonstrated that TCRP1 promoted cell proliferation and tumor growth in NSCLC. Regarding the mechanism, TCRP1 encouraged AKT phosphorylation and blocked FOXO3a nuclear localization through favoring FOXO3a ubiquitination in cytoplasm, thus, promoted cell cycle progression. Conclusionly, TCRP1 was upregulated in NSCLC cells with mutant p53. TCRP1 promoted NSCLC progression via regulating cell cycle.

Machine learning model to predict the efficacy of antiseizure medications in patients with familial genetic generalized epilepsy.

OBJECTIVE: This study aimed to establish a machine learning model that can predict the efficacy of antiseizure medications (ASMs) in patients with familial genetic generalized epilepsy (GGE). METHODS: We prospectively followed up patients with familial GGE for at least 3 years between January 2007 and January 2017. We collected and analyzed the patients' demographic characteristics, medical history, and related auxiliary examinations. The results of the epileptic seizures were divided into two categories: seizure-free and drug-resistant epilepsy. We selected and trained thirteen classification models, i.e., random forest classifier, logistic regression, gradient boosting classifier, light gradient boosting machine, ridge classifier, linear discriminant analysis, support vector machine-linear kernel, extra tree classifier, Ada boost classifier, naive Bayes classifier, decision tree classifier, K neighbors classifier, and quadratic discriminant analysis, to get the best performing classification model. RESULTS: A total of 854 patients with familial GGE were included in the study after excluding 89 who were lost to follow-up. Among them, 631 patients with familial GGE became seizure-free, and 223 developed drug-resistant epilepsy with a 74.89% remission rate. Among the 13 models, the random forest classifier model was the most effective with an accuracy of 91.23% and an F1 score of 84.21%. Among the 18 patient characteristics, the most effective indicators of the final treatment results were the number of seizure types experienced, response to the first drug, prior treatment duration and number of pre-treatment seizures. SIGNIFICANCE: The random forest classifier model can be used to early predict the results of ASM treatment based on the clinical data of patients with familial GGE. This finding can help clinicians make timely adjustments to treatment strategies and improve patients' prognosis.

Long noncoding RNA SGO1-AS1 inactivates TGFß signaling by facilitating TGFB1/2 mRNA decay and inhibits gastric carcinoma metastasis.

BACKGROUND: Although thousands of long noncoding RNAs (lncRNAs) have been annotated, only a few lncRNAs have been characterized functionally. In this study, we aimed to identify novel lncRNAs involved in the progression of gastric carcinoma (GC) and explore their regulatory mechanisms and clinical significance in GC. METHODS: A lncRNA expression microarray was used to identify differential lncRNA expression profiles between paired GCs and adjacent normal mucosal tissues. Using the above method, the lncRNA SGO1-AS1 was selected for further study. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH) were performed to detect SGO1-AS1 expression in GC tissues. Gain-of-function and loss-of-function analyses were performed to investigate the functions of SGO1-AS1 and its upstream and downstream regulatory mechanisms in vitro and in vivo. RESULTS: SGO1-AS1 was downregulated in gastric carcinoma tissues compared to adjacent normal tissues, and its downregulation was positively correlated with advanced clinical stage, metastasis status and poor patient prognosis. The functional experiments revealed that SGO1-AS1 inhibited GC cell invasion and metastasis in vitro and in vivo. Mechanistically, SGO1-AS1 facilitated TGFB1/2 mRNA decay by competitively binding the PTBP1 protein, resulting in reduced TGFß production and, thus, preventing the epithelial-to-mesenchymal transition (EMT) and metastasis. In addition, in turn, TGFß inhibited SGO1-AS1 transcription by inducing ZEB1. Thus, SGO1-AS1 and TGFß form a double-negative feedback loop via ZEB1 to regulate the EMT and metastasis. CONCLUSIONS: SGO1-AS1 functions as an endogenous inhibitor of the TGFß pathway and suppresses gastric carcinoma metastasis, indicating a novel potential target for GC treatment.

Hypoxia downregulated miR-4521 suppresses gastric carcinoma progression through regulation of IGF2 and FOXM1.

BACKGROUND: MicroRNAs (miRNAs) show considerable promise as therapeutic agents to improve tumor treatment, as they have been revealed as crucial modulators in tumor progression. However, our understanding of their roles in gastric carcinoma (GC) metastasis is limited. Here, we aimed to identify novel miRNAs involved in GC metastasis and explored their regulatory mechanisms and therapeutic significance in GC. METHODS: The microRNA expression profiles of GC tumors at different stages and at different metastasis statuses were compared respectively using the stomach adenocarcinoma (STAD) miRNASeq dataset in TCGA. Using the above method, miR-4521 was picked out for further study. miR-4521 expression in GC tissues was examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH). Highly and lowly invasive cell sublines were established using a repetitive transwell assay. Gain-of-function and loss-of-function analyses were performed to investigate the functions of miR-4521 and its upstream and downstream regulatory mechanisms in vitro and in vivo. Moreover, we investigated the therapeutic role of miR-4521 in a mouse xenograft model. RESULTS: In this study, we found that miR-4521 expression was downregulated in GC tissues compared with adjacent normal tissues and that its downregulation was positively correlated with advanced clinical stage, metastasis status and poor patient prognosis. Functional experiments revealed that miR-4521 inhibited GC cell invasion and metastasis in vitro and in vivo. Further studies showed that hypoxia repressed miR-4521 expression via inducing ETS1 and miR-4521 mitigated hypoxia-mediated metastasis, while miR-4521 inactivated the AKT/GSK3ß/Snai1 pathway by targeting IGF2 and FOXM1, thereby inhibiting the epithelial-mesenchymal transition (EMT) process and metastasis. In addition, we demonstrated that therapeutic delivery of synthetic miR-4521 suppressed gastric carcinoma progression in vivo. CONCLUSIONS: Our results suggest an important role for miR-4521 in regulating GC metastasis and hypoxic response of tumor cells as well as the therapeutic significance of this miRNA in GC.

FOXO3a-driven miRNA signatures suppresses VEGF-A/NRP1 signaling and breast cancer metastasis.

Metastasis remains the major obstacle to improved survival for breast cancer patients. Downregulation of FOXO3a transcription factor in breast cancer is causally associated with the development of metastasis through poorly understood mechanisms. Here, we report that FOXO3a is functionally related to the inhibition of VEGF-A/NRP1 signaling and to the consequent suppression of breast cancer metastasis. We show that FOXO3a directly induces miR-29b-2 and miR-338 expression. Ectopic expression of miR-29b-2/miR-338 significantly suppresses EMT, migration/invasion, and in vivo metastasis of breast cancer. Moreover, we demonstrate that miR-29b-2 directly targets VEGF-A while miR-338 directly targets NRP1, and show that regulation of miR-29b-2 and miR-338 mediates the ability of FOXO3a to suppress VEGF-A/NRP1 signaling and breast cancer metastasis. Clinically, our results show that the FOXO3a-miR-29b-2/miR-338-VEGF-A/NRP1 axis is dysregulated and plays a critical role in disease progression in breast cancer. Collectively, our findings propose that FOXO3a functions as a metastasis suppressor, and define a novel signaling axis of FOXO3a-miRNA-VEGF-A/NRP1 in breast cancer, which might be potential therapeutic targets for breast cancer.

Serum Exosomal Proteins F9 and TSP-1 as Potential Diagnostic Biomarkers for Newly Diagnosed Epilepsy.

Epilepsy is one of the most common chronic neurological diseases in the world, with a high incidence, a high risk of sudden unexplained death, and diagnostic challenges. Exosomes are nanosized extracellular vesicles that are released into physical environments and carry a variety of biological information. Moreover, exosomes can also be synthesized and released from brain cells, passing through the blood-brain barrier, and can be detected in peripheral blood or cerebrospinal fluid. Our study using the tandem mass tag (TMT) approach showed that a total of 76 proteins were differentially expressed in serum exosomes between epilepsy patients and healthy controls, with 6 proteins increasing and 70 proteins decreasing. Analysis of large clinical samples and two mouse models of chronic epilepsy indicated that two significantly differentially expressed serum exosomal proteins, coagulation factor IX (F9) and thrombospondin-1 (TSP-1), represent promising biomarkers for the diagnosis of epilepsy, with area under the curve (AUC) values of up to 0.7776 (95% CI, 0.7306-0.8246) and 0.8534 (95% CI, 0.8152-0.8916), respectively. This is the first study of exosomal proteins in epilepsy, and it suggests that exosomes are promising new tools for the diagnosis of epilepsy.

Downregulation of FOXO3a by DNMT1 promotes breast cancer stem cell properties and tumorigenesis.

Breast cancer stem cells (BCSCs) are tumor initiating cells that can self-renew and are highly tumorigenic and chemoresistant. Therefore, the identification of factors critical for BCSC function is vital for the development of therapies. Here, we report that DNMT1-mediated FOXO3a promoter hypermethylation leads to downregulation of FOXO3a expression in breast cancer. FOXO3a is functionally related to the inhibition of FOXM1/SOX2 signaling and to the consequent suppression of BCSCs properties and tumorigenicity. Moreover, we found that SOX2 directly transactivates DNMT1 expression and thereby alters the methylation landscape, which in turn feedback inhibits FOXO3a expression. Inhibition of DNMT activity suppressed tumor growth via regulation of FOXO3a/FOXM1/SOX2 signaling in breast cancer. Clinically, we observed a significant inverse correlation between FOXO3a and FOXM1/SOX2/DNMT1 expression levels, and loss of FOXO3a expression or increased expression of FOXM1, SOX2, and DNMT1 predicted poor prognosis in breast cancer. Collectively, our findings suggest an important role of the DNMT1/FOXO3a/FOXM1/SOX2 pathway in regulating BCSCs properties, suggesting potential therapeutic targets for breast cancer.

Epidemiology of Antibody-Positive Autoimmune Encephalitis in Southwest China: A Multicenter Study.

In recent years, as an increasing number of neuronal autoantibodies have been detected and used for clinical diagnosis, clinicians have become more aware of autoimmune encephalitis, causing its reported incidence to trend upward over several years. To date, however, there has been no large-scale epidemiological survey of autoimmune encephalitis in adults and children, and its epidemiological characteristics remain unclear. Six main types of antibodies are detected and used to diagnose autoimmune encephalitis in Chongqing, Southwestern China: anti-NMDA receptor antibody, anti-GABAB receptor antibody, anti-LGI1 antibody, anti-CASPR2 antibody, anti-AMPA1 receptor antibody, and anti-AMPA2 receptor antibody. From January 2012 to February 2018, 189 patients at six general hospitals in Chongqing were diagnosed with autoimmune encephalitis and were positive for neuronal autoantibodies. In this report, the epidemic situation and the antibody distribution among these patients are analyzed and described in detail. The differences in disease severity among different ages and between the sexes are evaluated, and the correlation between antibody titer and disease severity is also assessed.

Cip2a/miR-301a feedback loop promotes cell proliferation and invasion of triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype and lacks effective targeted therapies. Cancerous inhibitor of protein phosphatase 2A (Cip2a) is an oncogene that is known to inhibit PP2A tumor suppressor activity in human malignancies. We previously demonstrated that Cip2a is a novel target for the treatment of TNBC. However, the functional roles of Cip2a in TNBC progression are still not fully characterized. In this study, we identified that miR-301a is a novel target of Cip2a in TNBC cell lines by miRNA microarray analysis. We found that Cip2a increases E2F1 expression, which in turn transcriptional activates miR-301a by occupying the miR-301a host gene SKA2 promoter. Moreover, we found that miR-301a level is significantly increased in TNBC tissues, and up-regulation of miR-301a is responsible for Cip2a-induced cell proliferation and invasion of TNBC cells. Furthermore, miR-301a feedback promotes the expression of Cip2a via activation of ERK/CREB signaling. Together, our study suggests an auto-regulatory feedback loop between Cip2a and miR-301a and this auto-regulatory loop might play an important role in TNBC progression.

Application of Plasma Exchange in Steroid-Responsive Encephalopathy.

Plasma exchange has been widely used in autoimmune neurological diseases and is the standard treatment for myasthenia gravis crisis and Guillain-Barre syndrome. A growing body of research suggests that, in the clinical application of steroid-responsive encephalopathy, such as for Hashimoto's encephalopathy, limbic encephalitis, systemic lupus erythematosus encephalopathy, ANCA-associated vasculitis encephalopathy, and acute disseminated encephalomyelitis, plasma exchange is a safe, and effective option when steroids or other immunosuppressive therapies are ineffective in the short term or when contraindications are present. Additionally, plasma exchange can also be used alone or in combination with steroids, immunoglobulins, or other immunosuppressive agents to treat steroid-responsive encephalopathy. This paper reviews the clinical application of plasma exchange in steroid-responsive encephalopathy, including its indications, onset time, course, curative effects, and side effects.

miR-22/KAT6B axis is a chemotherapeutic determiner via regulation of PI3k-Akt-NF-kB pathway in tongue squamous cell carcinoma.

BACKGROUND: Tongue squamous cell carcinoma (TSCC) is the most common oral cancer. Neoadjuvant systemic treatment before or after surgery for advanced TSCC is considered one of the most crucial factors in reducing mortality. However, the therapeutic benefits of chemotherapy are usually attenuated due to intrinsic and/or acquired drug resistance, and a large proportion of TSCC are resistant to chemotherapy, which may result in more aggressive tumor behavior and an even worse clinical outcome. Recently, the potential application of using miRNAs to predict therapeutic response to cancer treatment holds high promise, but miRNAs with predictive value remain to be identified and underlying mechanisms remain to be understood in TSCC. METHODS: The expression of miR-22 in tissues from patients diagnosed with TSCC was analyzed using real-time PCR. The effects of miR-22 on cell proliferation and tumorigenesis in TSCC cells were analyzed by MTS assay, and flow cytometry. The tumor growth in vivo was observed in xenograft model. Luciferase reporter assay, real-time PCR and western blot were performed to validate a potential target of miR-22 in TC. The correlation between miR-22 expression and KAT6B expression, as well as the mechanisms by which miR-22 regulates PI3k-Akt-NF-kB pathway in TSCC were also addressed. RESULTS: We found a strong correlation between miR-22 expression and chemosensitivity to cisplatin (CDDP) in TSCC patients. Ectopic overexpression of miR-22 enhanced TSCC cells apoptosis in response to CDDP in experimental models performed in vitro and in vivo. Moreover, we found that KAT6B is a direct functional target of miR-22. Ectopic expression of KAT6B attenuated the efficiency of miR-22 in TSCC cells upon CDDP treatment. Mechanistically, miR-22 overexpression or KAT6B knockdown inhibited PI3K/Akt/NF-κB signaling in TSCC cells, possibly via downregulating the activators of PI3K/Akt/NF-κB signaling, such as S100A8, PDGF and VEGF. Furthermore, the activation of miR-22 depended on the intensity of the stresses in the presence of p53 activation. CONCLUSIONS: Our findings define miR-22 as an intrinsic molecular switch that determines p53-dependent cellular fate through KAT6B/ PI3K-Akt/ NF-kB pathway.

HSP27-Mediated Extracellular and Intracellular Signaling Pathways Synergistically Confer Chemoresistance in Squamous Cell Carcinoma of Tongue.

Purpose: Squamous cell carcinoma of tongue (SCCT) is the most common type of oral cavity carcinoma. Chemoresistance in SCCT is common, and the underlying mechanism remains largely unknown. We aimed to identify key molecules and signaling pathways mediating chemoresistance in SCCT.Experimental Design: Using a proteomic approach, we found that the HSP27 was a potential mediator for chemoresistance in SCCT cells. To further validate this role of HSP27, we performed various mechanistic studies using in vitro and in vivo models as well as serum and tissue samples from SCCT patients.Results: The HSP27 protein level was significantly increased in the multidrug-resistant SCCT cells and cell culture medium. Both HSP27 knockdown and anti-HSP27 antibody treatment reversed chemoresistance. Inversely, both HSP27 overexpression and recombinant human HSP27 protein treatment enhanced chemoresistance. Moreover, chemotherapy significantly induced HSP27 protein expression in both SCCT cells and their culture medium, as well as in tumor tissues and serum of SCCT patients. HSP27 overexpression predicts a poor outcome for SCCT patients receiving chemotherapy. Mechanically, extracellular HSP27 binds to TLR5 and then activates NF-κB signaling to maintain SCCT cell survival. TLR5 knockdown or restored IκBα protein level disrupts extracellular HSP27-induced NF-κB transactivation and chemoresistance. Moreover, intracellular HSP27 binds to BAX and BIM to repress their translocation to mitochondrion and subsequent cytochrome C release upon chemotherapy, resulting in inhibition of the mitochondrial apoptotic pathway.Conclusions: HSP27 plays a pivotal role in chemoresistance of SCCT cells via a synergistic extracellular and intracellular signaling. HSP27 may represent a potential biomarker and therapeutic target for precision SCCT treatment. Clin Cancer Res; 24(5); 1163-75. ©2017 AACR.