Therapeutic effectiveness of anlotinib combined with etoposide in extensive-stage small-cell lung cancer: a single-arm, phase II trial.

BACKGROUND: Anlotinib plus chemotherapy as first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC) achieves good efficacy, but there is still room for improvement. This clinical study examined the effectiveness of anlotinib plus etoposide for maintenance therapy in ES-SCLC. METHODS: The current single-arm, prospective phase II study was performed at Jiangsu Cancer Hospital (March 2019 to March 2022). After successful primary etoposide-based therapy, anlotinib was administered at 12 mg/day on days 1 to 14 of 21-day cycles until disease progression or consent withdrawal. All patients also received etoposide at 50 mg/day on days 1 to 14 of 21-day cycles for a maximum of six cycles. Progression-free survival (PFS) constituted the primary study endpoint. Secondary endpoints were overall survival (OS), objective remission rate (ORR), disease control rate (DCR), and safety. In addition, adverse events (AEs) were assessed. RESULTS: Twenty-eight patients were treated. Median PFS and OS were 8.02 (95%CI 5.36-10.67) and 11.04 (95%CI 10.37-11.68) months, respectively. Totally 9 and 18 participants showed a partial response and stable disease, respectively; ORR and DCR were 32.14% and 96.43%, respectively. The commonest all-grade AEs were fatigue (n = 11, 39.28%), hypertension (n = 11, 39.28%), loss of appetite (n = 9, 32.14%), oral mucositis (n = 7, 25.00%) and proteinuria (n = 6, 21.40%). Grade 3-4 AEs included fatigue (n = 4, 14.28%), hypertension (n = 2, 7.14%), hand and foot syndrome (n = 2, 7.14%), oral mucositis (n = 1, 3.57%), hemoptysis (n = 1, 3.57%), proteinuria (n = 1, 3.57%), gingival bleeding (n = 1, 3.57%), and serum creatinine elevation (n = 1, 3.57%). CONCLUSION: Maintenance anlotinib plus etoposide achieves promising PFS and OS in clinical ES-SCLC. REGISTRATION NUMBER: ChiCTR1800019421.

PDE4D/cAMP/IL-23 axis determines the immunotherapy efficacy of lung adenocarcinoma via activating the IL-9 autocrine loop of cytotoxic T lymphocytes.

Although immunotherapy has changed the prognosis of many advanced malignancies including lung adenocarcinoma (LUAD), many patients are insensitive to the drugs, with the mechanisms yet to be elucidated. Herein, we identified PDE4D as an immunotherapy efficacy-related gene through bioinformatics screening. By using a co-culture system of LUAD cells and tumor-cell-specific CD8+ T cells, a functional PDE4D/cAMP/IL-23 axis was further revealed in LUAD cells. Fluorescent multiplex immunohistochemistry analysis of patient-derived samples and the in vivo mouse LUAD xenograft tumors revealed not only the colocalization of IL-23 and CD8+ T cells but also the immune potentiating effect of IL-23 on cytotoxic T lymphocytes (CTLs) in LUAD tissues. Through transcriptome sequencing and functional validations, IL-23 was proven to up-regulate IL-9 expression in CTLs via activating the NF-κB signaling, leading to elevated productions of immune effector molecules and enhanced efficacy of antitumor immunotherapy. Interestingly, an autocrine loop of IL-9 was also uncovered during this process. In conclusion, PDE4D/cAMP/IL-23 axis determines the immunotherapy efficacy of human LUAD. This effect is mediated by the activation of an NF-κB-dependent IL-9 autocrine loop in CTLs.

Peripheral blood lymphocytes differentiation patterns in responses / outcomes to immune checkpoint blockade therapies in non-small cell lung cancer: a retrospective study.

OBJECTIVES: Programmed Cell Death-1/ Programmed Death-ligand 1 (PD-1 / PD-L1) inhibitor therapies targeting immunocytes induce persistent tumor remission in various cancers. However, the appropriate biomarkers for the therapeutic efficacy of PD-L1 and PD-1 blockade remain elusive. MATERIALS AND METHODS: For a comprehensive analysis of peri-treatment lymphocyte differentiation, in the current study, we enrolled 146 non-small cell lung cancer patients who received α-PD-1 therapies for exploring the peripheral blood lymphocyte differentiation pattern at baseline and post-treatment (dynamic changes) by flow cytometry. RESULTS: At baseline, CD4+ / CD8+ T cell ratio predicts good responses and outcomes, but activated T cell and cytotoxic T cell counts predict poor responses and outcomes. And for dynamic changes, after 6 weeks of immune checkpoint blockade (ICB) treatment, compared with baseline level, the elevation of total T and B cell counts indicate poor responses, and total T and TH cell counts indicate poor prognosis while activated T cell predicts good prognosis. And after 12 weeks, elevated total lymphocyte, cytotoxic T cell counts, and decreased total T cell counts and CD4+ / CD8+ T cell ratio predict good responses / outcomes. Our clinical predicting model shows good performance in predicting ICB treatment responses / outcomes. CONCLUSION: Patients with favorable clinical responses / outcomes have distinctive peripheral blood immunocyte differentiation characteristics, indicating the potential of utilizing the peripheral immunocyte differentiation patterns for predicting ICB responses / outcomes.

A Prognostic Risk Model of a Novel Oxidative Stress-Related Signature Predicts Clinical Prognosis and Demonstrates Immune Relevancy in Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD) is among the most prevalent malignant lung cancers with a poor prognosis due to high invasiveness and lethality despite multiple treatments. Since the lung is an important organ associated with oxidative stress, and it has been confirmed that oxidative stress represents a potential cancer-specific depletion, it is of important significance to investigate and evaluate the clinical value of oxidative stress mechanisms regulating tumor cell apoptosis. Furthermore, there are few studies on the impact of the microenvironment on reaction to immune-checkpoint inhibitors (ICIs) in patients with LUAD. Based on the TCGA-LUAD dataset, which is stratified into a training set as well as a validation set in a ratio of 2 : 1, this investigation constructs and validates a prognostic predictive power of a gene signature model of oxidative stress-related prognostic signatures. To ascertain the differences between the high-risk score group and the low-risk score group in tumor-infiltrating lymphocytes and patients' response to ICI therapy. This oxidative stress-related prognostic gene signature is composed of MAP3K19 and NTSR1 and is an independent prognosis-related factor in the LUAD group. The outcome of patients having a low risk score is better, and the difference was statistically significant, and individuals with a low risk score had a larger number of infiltrating immune cell distribution in the tumor microenvironment, which was closely related to clinical outcome. Our study suggests that the synergistic effect of oxidative stress-related prognostic gene markers-MAP3K19 and NTSR1 has clinical significance in the prognosis identification and immunotherapy of LUAD patients. Thus, the results may help to better intersect the oxidative stress-related mechanisms in clinical value in LUAD but requires prospective validation.

An exploration of the clinical progression models of osimertinib in the treatment of advanced EGFR-mutant non-small cell lung cancer.

Background: Classifying the progression pattern had been proved to be momentous for predicting efficacy and guiding treatment in the 1st/2nd generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), while lack evidence in the 3rd generation EGFR-TKIs. This study aimed to classify tumor progression of osimertinib in EGFR+ advanced non-small cell lung cancer (NSCLC), exploring the characteristics and the clinical significance of each progression pattern. Methods: After screening 1,125 lung cancer patients, 168 EGFR T790M+ advanced patients using osimertinib were enrolled and divided into two groups and five clinical progression models according to the time course of the tumor progression. The prognosis and characteristics, such as gender, age, metastases, of each model were analyzed and compared by Kaplan-Meier method, t-test, and linear regression. Results: Complete follow-up data were available for 117 of the 168 patients. Progressive disease (PD) occurred in 89 patients at an average onset of 6.59 months since using osimertinib, with 79.78% of patients experiencing enlargement of some preexisting lesions before PD. Among the five progression models, the 'Rapid Enlargement' (10.11%) model, the 'Rapid New Lesion' model (10.11%), the 'Delayed Enlargement' model (29.21%), the 'Delayed New Lesion' model (15.73%), and the 'Non-targeted Enlargement' model (34.83%), the 'Non-targeted Enlargement' model had the worst prognosis, with a median progression-free survival (mPFS) of 7.1 months (P=0.046). The mPFS of other models was similar, with the largest difference in the time interval between the beginning of osimertinib treatment to the first appearance of target lesion enlargement (Tm-e). Smoking history (P=0.046) and the location of the initial (P=0.048), enlarged (P=0.003), and progressive lesions (P=0.002) affected the progression models, while gender, age, and treatment lines had no effect. The Tm-e was related to the overall disease control time with a correlation coefficient of 0.667 (P=0.000). The appearance of a malignant pleural effusion had an impact on progression. Conclusions: We tried to create a classification system for describing the failure of the third-generation EGFR-TKI osimertinib including two groups, subdivided into five progression models based on the time course of tumor lesion changes. The system might be conducive to predict the prognosis and be potential to assist in selecting subsequent treatment strategies.

Corrigendum: Association of Dynamic Changes in Peripheral Blood Indexes With Response to PD-1 Inhibitor-Based Combination Therapy and Survival Among Patients With Advanced Non-Small Cell Lung Cancer.

[This corrects the article DOI: 10.3389/fimmu.2021.672271.].

Association of Dynamic Changes in Peripheral Blood Indexes With Response to PD-1 Inhibitor-Based Combination Therapy and Survival Among Patients With Advanced Non-Small Cell Lung Cancer.

Background: PD-1 inhibitors have been routinely used in the treatment of advanced non-small cell lung cancer (NSCLC), and have demonstrated to significantly improve survivorship when combining with other conventional therapies, such as chemotherapy and anti-angiogenesis therapy. PD-L1 is the most commonly used biomarker to select benefiting groups, while not all patients with high PD-L1 expression benefit from immunotherapy. Therefore, identifying other prognostic and predictive biomarkers, including peripheral blood indexes, is essential. Methods: We retrospectively collected medical records and hematological data of 151 patients with advanced NSCLC treated with PD-1 inhibitor-based combination therapy in our hospital. The peripheral blood indexes of interest were NLR, PLR, PAR, Hb, LDH, CEA, and NSE. The association between peripheral blood indexes and treatment responses or survival outcomes was examined by multivariable logistic regression and Cox regression, respectively. Results: The decreased CEA at week 6 (OR = 4.209, 95%CI: 1.287-13.758) or 12 (OR = 7.267, 95%CI: 1.508-35.006) post-treatment was related to a higher disease control rate. The decrease or NLR at week 6 (OR = 3.081, 95%CI: 1.464-6.483) or 12 (OR = 3.304, 95%CI: 1.560-7.001) post-treatment, or CEA at week 12 post-treatment (OR = 2.469, 95%CI: 1.134-5.375), was associated with a higher objective response rate. Patients whose NLR (HR = 0.610, 95%CI: 0.411-0.907) or CEA (HR = 0.477, 95%CI: 0.320-0.710) decreased at week 6 post-treatment tended to have longer progression-free survival, and similar results were found in those with decreased NLR (HR = 0.587, 95%CI: 0.388-0.886) or CEA (HR = 0.406, 95%CI: 0.270-0.609) at week 12 post-treatment. Patients whose CEA (HR = 0.543, 95%CI: 0.339-0.871) or NSE (HR = 0.619, 95%CI: 0.386-0.994) decreased after 6 weeks post-treatment appeared to have longer overall survival, and the same was found for those whoseCEA (HR = 0.620, 95%CI: 0.390-0.986) or NSE (HR = 0.578, 95%CI: 0.353-0.947) was decreased at 12 weeks after treatment. Conclusion: Post-treatment NLR, CEA and NSE changes are suggestive indicators for the prognosis of NSCLC patients after immunotherapy.

LncRNA SNHG15 regulates EGFR-TKI acquired resistance in lung adenocarcinoma through sponging miR-451 to upregulate MDR-1.

Lung adenocarcinoma (LUAD) is the main component of non-small-cell lung cancer (NSCLC) and causes a great health concern globally. The top priority of LUAD treatment is to deal with gefitinib resistance. Long non-coding RNAs are certified to modify gefitinib resistance in the course of tumor aggravation. The study focuses on addressing the function of small nucleolar RNA host gene 15 (SNHG15) on modifying gefitinib resistance in LUAD. Previously, NOTCH pathway is implicated in LUAD chemo-resistance. SNHG15 level was boosted following the depletion of NOTCH-1 in A549/GR and H1975/GR cells. Functional studies indicated that SNHG15 and multidrug resistance protein 1 (MDR-1) were overexpressed and possess tumor-promoting functions in gefitinib-resistant LUAD cells while miR-451 was downregulated and possess tumor-suppressive behaviors in gefitinib-resistant LUAD cells. Mechanically, the SNHG15 was cytoplasmically distributed in GR LUAD cells. In addition, SNHG15 released MDR-1 from the suppression of miR-451, leading to MDR-1 promotion. In addition, the elevation of SNHG15 could be attributed to ZEB1. Rescue assays highlighted that downstream molecules MDR-1 and miR-451 could reverse the effects of SNHG15 downregulation on gefitinib-resistant LUAD cells. SNHG15 could alter chemo-resistance of LUAD cells to Gefitinib via regulating miR-451/MDR-1, which could be inspiring findings for the advancement of chemo-therapies for LUAD.

TFAP2C-Activated MALAT1 Modulates the Chemoresistance of Docetaxel-Resistant Lung Adenocarcinoma Cells.

Chemoresistance remains a great obstacle in effective lung adenocarcinoma (LUAD) treatment. Previously, we verified the role of microRNA-200b (miR-200b) in the formation of docetaxel (DTX)-resistant LUAD cells. This study aims to investigate the mechanism underlying the low level of miR-200b in DTX-resistant LUAD cells. The real-time reverse transcription (RT2) lncRNA PCR array system was applied to explore lncRNAs that potentially regulated miR-200b in DTX-resistant LUAD cells. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) contributed to the low miR-200b level in DTX-resistant LUAD cells. Functional assays were conducted to determine the role of MALAT1 in regulating the growth and metastasis of parental and DTX-resistant LUAD cells. Investigation revealed the mechanism of the competing endogenous RNA (ceRNA) pathway. MALAT1 regulated miR-200b by acting as a ceRNA. MALAT1 modulated the sensitivity of LUAD cells to DTX. E2F transcription factor 3 (E2F3) and zinc-finger E-box binding homeobox 1 (ZEB1) were two targets of miR-200b and mediated the function of MALAT1 in DTX-resistant LUAD cells. Transcription factor AP-2 gamma (TFAP2C) and ZEB1 activated the MALAT1 transcription. In conclusion, TFAP2C-activated MALAT1 modulated the chemoresistance of LUAD cells by sponging miR-200b to upregulate E2F3 and ZEB1. Our findings may provide novel therapeutic targets and perspectives for LUAD treatment.

Overexpression of Sirtuin-1 is associated with poor clinical outcome in esophageal squamous cell carcinoma.

Sirtuin-1 (SIRT1), one member of the mammalian sirtuin family, has been suggested to play an essential role in the development and progression of many tumors. However, the relationship between expression of SIRT1 and prognosis of esophageal cancer is still unknown. This study aimed to investigate SIRT1 expression and its possible prognostic value in esophageal squamous cell carcinoma (ESCC). A total of 86 patients with ESCC were enrolled in our study group. Clinical data and matched tissues were collected. Western blotting and real-time quantitative reverse transcription PCR (RT-PCR) were carried out to explore the expression of SIRT1 in four human ESCC cell lines, one human normal epithelial cell line, and clinical ESCC tissues. Expression levels of SIRT1 protein in tissues of specimens were detected by immunohistochemistry (IHC). Survival analysis was carried out using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were performed to evaluate the correlation of SIRT1 expression with clinical features and prognosis of ESCC patients. Basal expression levels of SIRT1 protein in ESCC tumor tissues and cell lines were higher than those in the control groups. IHC analysis showed that expression levels of SIRT1 protein significantly correlated with TNM stage and lymph node status of ESCC patients. Moreover, upregulated SIRT1 expression was associated with poor clinical prognosis. High SIRT1 expression in ESCC could serve as an independent predictive biomarker for diagnosis and prognosis in ESCC patients.

MiR-200b regulates autophagy associated with chemoresistance in human lung adenocarcinoma.

Chemoresistance remains a major clinical problem in combating human lung adenocarcinoma (LAD), and abnormal autophagy is closely associated with this phenomenon. In the present study, an inverse correlation between miR-200b and autophagy-associated gene 12 (ATG12) expressions was observed in docetaxel-resistant (SPC-A1/DTX and H1299/DTX) and sensitive (SPC-A1 and H1299) LAD cells as well as in tissue samples. Further study showed that miR-200b directly targeted ATG12 in LAD. Moreover, miR-200b-dependent ATG12 downregulation inhibited autophagy and enhanced the chemosensitivity of SPC-A1/DTX and H1299/DTX cells both in vivo and in vitro. LAD chemoresistance is therefore closely related to downregulation of miR-200b and the corresponding upregulation of ATG12. These results provide new evidence for the mechanisms governing the microRNA (miRNA)-ATG12 network and their possible contribution to autophagy modulation and LAD chemoresistance.

Mir-24-3p downregulation contributes to VP16-DDP resistance in small-cell lung cancer by targeting ATG4A.

Although the combination of etoposide (VP16) and cisplatin (DDP) is widely used as a first-line treatment for advanced-stage small-cell lung cancer (SCLC), chemoresistance limits its clinical use. Abnormalities of autophagy are associated with tumor chemoresistance. The present study found that miR-24-3p, a recently discovered microRNA, is significantly downregulated in VP16-DDP-resistant SCLC cells (H446/EP) compared with VP16-DDP-sensitive parent cells (H446). Forced expression of miR-24-3p sensitized H446/EP cells to VP16-DDP treatment because of a blockade of autophagic activity. We further found that downregulated miR-24-3p enhanced autophagy activation as it directly targets and inhibits autophagy-associated gene 4A (ATG4A). Overexpression of miR-24-3p into H446/EP cells led to reduction of the ATG4A protein level, allowing SCLC cells to resensitize to VP16-DDP. We conclude that miR-24-3p regulates autophagy by targeting ATG4A. Inhibition of autophagy by increasing miR-24-3p could be the basis of a strategy to prevent and treat SCLC with combination chemotherapy, particularly in chemoresistant disease.

MicroRNA-451 induces epithelial-mesenchymal transition in docetaxel-resistant lung adenocarcinoma cells by targeting proto-oncogene c-Myc.

Epithelial-mesenchymal transition (EMT) has been reported to play a significant role in tumour metastasis as well as chemoresistance. However, the molecular mechanisms involved in chemotherapy-induced EMT are still unclear. MicroRNA (miRNA) expression and functions have been reported to contribute to phenotypic features of tumour cells. To investigate the roles of miRNAs in chemotherapy-induced EMT, we established two docetaxel-resistant lung adenocarcinoma (LAD) cell models (SPC-A1/DTX and H1299/DTX), which display EMT-like properties and gain increased invasion or migration activity. MiR-451 was found to be significantly downregulated in docetaxel-resistant LAD cells, and re-expression of miR-451 could reverse EMT to mesenchymal-epithelial transition (MET) and inhibit invasion and metastasis of docetaxel-resistant LAD cells both in vitro and in vivo. The proto-oncogene c-Myc was identified as a direct and functional target of miR-451, and further researches confirmed that overexpression of c-Myc which induced extracellular-signal-regulated kinase (ERK)-dependent glycogen synthase kinase-3 beta (GSK-3ß) inactivation and subsequent snail activation is essential for acquisition of EMT phenotype induced by loss of miR-451. Furthermore, c-Myc was significantly upregulated in docetaxel-non-responding LAD tissues in comparison with docetaxel-responding tissues, and its expression was inversely correlated with miR-451 expression. This study first reported the involvement of miR-451/c-Myc/ERK/GSK-3ß signalling axis in the acquisition of EMT phenotype in docetaxel-resistant LAD cells, suggesting that re-expression of miR-451 or targeting c-Myc will be a potential strategy for the treatment of chemoresistant LAD patients.

Histone deacetylase 1/Sp1/microRNA-200b signaling accounts for maintenance of cancer stem-like cells in human lung adenocarcinoma.

The presence of cancer stem-like cells (CSCs) is one of the mechanisms responsible for chemoresistance that has been a major hindrance towards lung adenocarcinoma (LAD) treatment. Recently, we have identified microRNA (miR)-200b as a key regulator of chemoresistance in human docetaxel-resistant LAD cells. However, whether miR-200b has effects on regulating CSCs remains largely unclear and needs to be further elucidated. Here, we showed that miR-200b was significantly downregulated in CD133+/CD326+ cells that exhibited properties of CSCs derived from docetaxel-resistant LAD cells. Also, restoration of miR-200b could inhibit maintenance and reverse chemoresistance of CSCs. Furthermore, suppressor of zeste-12 (Suz-12) was identified as a direct and functional target of miR-200b, and silencing of Suz-12 phenocopied the effects of miR-200b on CSCs. Additionally, overexpression of histone deacetylase (HDAC) 1 was identified as a pivotal mechanism responsible for miR-200b repression in CSCs through a specificity protein (Sp) 1-dependent mechanism, and restoration of miR-200b by HDAC1 repression significantly suppressed CSCs formation and reversed chemoresistance of CSCs by regulating Suz-12-E-cadherin signaling. Also, downregulation of HDAC1 or upregulation of miR-200b reduced the in vivo tumorigenicity of CSCs. Finally, Suz-12 was inversely correlated with miR-200b, positively correlated with HDAC1 and up-regulated in docetaxel-resistant LAD tissues compared with docetaxel-sensitive tissues. Taken together, the HDAC1/miR-200b/Suz-12-E-cadherin signaling might account for maintenance of CSCs and formation of chemoresistant phenotype in docetaxel-resistant LAD cells.

Acquisition of radioresistance in docetaxel-resistant human lung adenocarcinoma cells is linked with dysregulation of miR-451/c-Myc-survivin/rad-51 signaling.

Chemoresistant tumors usually fail to respond to radiotherapy. However, the mechanisms involved in chemo- and radiotherapy cross resistance are not fully understood. Previously, we have identified microRNA (miR)-451 as a tumor suppressor in lung adenocarcinoma (LAD). However, whether miR-451 plays critical roles in chemo- and radiotherapy cross resistance in LAD is unclear. Here, we established two docetaxel-resistant LAD cell models (SPC-A1/DTX and H1299/DTX), and showed that miR-451 was significantly downregulated in docetaxel-resistant LAD cells. Gain - and loss - of - function assays indicated that re-expression of miR-451 could reverse radioresistance of docetaxel-resistant LAD cells both in vitro and in vivo through promoting apoptosis and DNA double-strand breaks (DSBs). The proto-oncogene c-Myc was identified as a direct target of miR-451, and re-expression of miR-451 inhibited survivin and rad-51 expression by reducing the amount of c-Myc protein binding to their promoters. Silencing of c-Myc could phenocopy the effects of miR-451 upregulation, and restoration of c-Myc could partially rescue the effect of miR-451 upregulation on radiosensitivity of docetaxel-resistant LAD cells. Therefore, dysregulation of miR-451/c-Myc-survivin/rad-51 signaling is responsible for radioresistance of docetaxel-resistant LAD cells, and targeting it will be a potential strategy for reversing chemo- and radiotherapy cross resistance of LAD patients.

HMGB1-mediated autophagy promotes docetaxel resistance in human lung adenocarcinoma.

BACKGROUND: Docetaxel resistance remains a major obstacle in the treatment of non-small cell lung cancer (NSCLC). High-mobility group box 1 (HMGB1) has been shown to promote autophagy protection in response to antitumor therapy, but the exact molecular mechanism underlying HMGB1-mediated autophagy has not been clearly defined. METHODS: Lung adenocarcinoma (LAD) cells were transfected with pcDNA3.1-HMGB1 or HMGB1 shRNA, followed by docetaxel treatment. Cell viability and proliferation were tested by MTT assay and colony formation assay, respectively. Annexin V flow cytometric analysis and western blot analysis of activated caspase3 and cleaved PARP were used to evaluate apoptosis, while immunofluorescence microscopy and transmission electron microscopy were applied to assess autophagy activity. The formation of the Beclin-1-PI3K-III complex was examined by immunoprecipitation analysis. NOD/SCID mice were inoculated with docetaxel-resistant SPC-A1/DTX cells transfected with control or HMGB1 shRNA. RESULTS: HMGB1 translocated from the nucleus to the cytoplasm in LAD cells exposed to docetaxel and acted as a positive regulator of autophagy, which inhibited apoptosis and increased drug resistance. Suppression of HMGB1 restored the sensitivity of LAD cells to docetaxel both in vivo and in vitro. Mechanistic investigation revealed that HMGB1 promoted the formation of the Beclin-1-PI3K-III complex through activating the mitogen-activated protein kinase (MEK)-extracellular signal-regulated kinase (ERK) signaling pathway, thereby regulating autophagosome formation. CONCLUSIONS: Our results demonstrated that HMGB1-regulated autophagy is a significant contributor to docetaxel resistance in LAD cells. Suppression of HMGB1 or limiting HMGB1 cytosolic translocation diminished autophagic protection in response to docetaxel in LAD cells.

HDAC 1/4-mediated silencing of microRNA-200b promotes chemoresistance in human lung adenocarcinoma cells.

Chemoresistance is one of the most significant obstacles in lung adenocarcinoma (LAD) treatment, and this process involves genetic and epigenetic dysregulation of chemoresistance-related genes. Previously, we have shown that restoration of microRNA (miR)-200b significantly reverses chemoresistance of human LAD cells by targeting E2F3. However, the molecular mechanisms involved in the silencing of miR-200b are still unclear. Here we showed that histone deacetylase (HDAC) inhibitors could restore the expression of miR-200b and reverse chemoresistant phenotypes of docetaxel-resistant LAD cells. HDAC1/4 repression significantly increased miR-200b expression by upregulating histone-H3 acetylation level at the two miR-200b promoters partially via a Sp1-dependent pathway. Furthermore, silencing of HDAC1/4 suppressed cell proliferation, promoted cell apoptosis, induced G2/M cell cycle arrest and ultimately reversed in vitro and in vivo chemoresistance of docetaxel-resistant LAD cells, at least partially in a miR-200b-dependent manner. HDAC1/4 suppression-induced rescue of miR-200b contributed to downregulation of E2F3, survivin and Aurora-A, and upregulation of cleaved-caspase-3. HDAC1/4 levels in docetaxel-insensitive human LAD tissues, inversely correlated with miR-200b, were upregulated compared with docetaxel-sensitive tissues. Taken together, our findings suggest that the HDAC1/4/Sp1/miR-200b/E2F3 pathway is responsible for chemoresistance of docetaxel-resistant LAD cells.

Featured article: autophagic activation with nimotuzumab enhanced chemosensitivity and radiosensitivity of esophageal squamous cell carcinoma.

Chemotherapy and radiotherapy are two indispensible methods for esophageal squamous cell carcinoma (ESCC), especially for those recurring and metastatic ones, but therapeutic toxicity remains a major problem to overcome. In the present study, the potential therapeutic value of nimotuzumab (an antiepidermal growth factor receptor [EGFR] monoclonal antibody) in combination with chemotherapy and radiotherapy was evaluated on Eca109 and TE-1 ESCC cells, with high and low expression of EGFR, respectively. It was shown that nimotuzumab enhanced the sensitivity of Eca109 cells to other cytotoxic agents (paclitaxel and cis-platinum) and X-ray radiation, and the cytotoxicity was associated with increased autophagy. Conversely, the chemo- and radio-sensitivity of TE-1 cells showed no improvement with addition of nimotuzumab, but could be increased by combining with rapamycin, an autophagy inducer. Therefore, it was concluded that autophagic activation mediated by nimotuzumab could promote autophagic cell death and produce additive antitumor effects.

Clinical significance of angiopoietin-like protein 4 expression in tissue and serum of esophageal squamous cell carcinoma patients.

Angiopoietin-like protein 4 (ANGPTL4) has been reported to promote tumor growth, metastasis, and angiogenesis under certain conditions. The aim of this study was to examine ANGPTL4 expression in tumor and serum tissues from esophageal squamous cell carcinoma (ESCC) patients. A total of 78 ESCC patients treated with radical resection were enrolled in this study. Immunohistochemistry was used to detect ANGPTL4 expression in ESCC tissues. Serum ANGPTL4 levels were determined via enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristics curve was constructed to describe diagnostic specificity and sensitivity. There were 52 cases (69.2 %) showing a higher level of ANGPTL4 expression in tumor tissues than that in normal tissues, and the rate of ANGPTL4 protein high/moderate expression in ESCC and normal tissues was 55.1 % (43/78) and 6.4 % (5/78), respectively, with a significant difference (P < 0.001). Moreover, the high/moderate of ANGPTL4 protein was significantly associated with lymph metastasis, clinical stage, and adverse 2-year progression-free survival. In addition, serum ANGPTL4 level in ESCC patients was much higher than that in patients with benign esophageal disease (P < 0.001), and area under the curve was 0.94 (95 % CI 0.886390-0.978173, P < 0.001). But serum ANGPTL4 level was significantly decreased at post-operative 7-10 days (P = 0.004). ANGPTL4 upregulation may play an important role in ESCC development, and serum ANGPTL4 level may be a potential tumor marker for ESCC diagnosis and prognosis.

Epigenetic downregulation of RUNX3 by DNA methylation induces docetaxel chemoresistance in human lung adenocarcinoma cells by activation of the AKT pathway.

The RUNX3 gene has been shown to function as a tumor suppressor gene implicated in various cancers, but its association with tumor chemoresistance has not been fully understood. Here, we investigated the effect of epigenetic downregulation of RUNX3 in docetaxel resistance of human lung adenocarcinoma and its possible molecular mechanisms. RUNX3 was found to be downregulated by hypermethylation in docetaxel-resistant lung adenocarcinoma cells. Its overexpression could resensitize cells to docetaxel both in vitro and in vivo by growth inhibition, enhancement of apoptosis and G1 phase arrest. Conversely, knockdown of RUNX3 could lead to the decreased sensitivity of parental human lung adenocarcinoma cells to docetaxel by enhancing proliferative capacity. Furthermore, we showed that overexpression of RUNX3 could inactivate the AKT/GSK3ß/ß-catenin signaling pathway in the docetaxel-resistant cells. Importantly, co-transfection of RUNX3 and constitutively active Akt1 could reverse the effects of RUNX3 overexpression, while treatment with the MK-2206 (AKT inhibitor) mimicked the effects of RUNX3 overexpression in docetaxel-resistant human lung adenocarcinoma cells. Immunohistochemical analysis revealed that decreased RUNX3 expression was correlated with high expression of Akt1 and decreased sensitivity of patients to docetaxel-based chemotherapy. Taken together, our results suggest that epigenetic downregulation of RUNX3 can induce docetaxel resistance in human lung adenocarcinoma cells by activating AKT signaling and increasing expression of RUNX3 may represent a promising strategy for reversing docetaxel resistance in the future.