The Raf-like MAPKKK INTEGRIN-LINKED KINASE 5 regulates purinergic receptor-mediated innate immunity in Arabidopsis.

Mitogen-activated protein (MAP) kinase signaling cascades play important roles in eukaryotic defense against various pathogens. Activation of the extracellular ATP (eATP) receptor P2K1 triggers MAP kinase 3 and 6 (MPK3/6) phosphorylation, which leads to an elevated plant defense response. However, the mechanism by which P2K1 activates the MAPK cascade is unclear. In this study, we show that in Arabidopsis thaliana, P2K1 phosphorylates the Raf-like MAP kinase kinase kinase (MAPKKK) INTEGRIN-LINKED KINASE 5 (ILK5) on serine 192 in the presence of eATP. The interaction between P2K1 and ILK5 was confirmed both in vitro and in planta and their interaction was enhanced by ATP treatment. Similar to P2K1 expression, ILK5 expression levels were highly induced by treatment with ATP, flg22, Pseudomonas syringae pv. tomato DC3000, and various abiotic stresses. ILK5 interacts with and phosphorylates the MAP kinase MKK5. Moreover, phosphorylation of MPK3/6 was significantly reduced upon ATP treatment in ilk5 mutant plants, relative to wild-type (WT). The ilk5 mutant plants showed higher susceptibility to P. syringae pathogen infection relative to WT plants. Plants expressing only the mutant ILK5S192A protein, with decreased kinase activity, did not activate the MAPK cascade upon ATP addition. These results suggest that eATP activation of P2K1 results in transphosphorylation of the Raf-like MAPKKK ILK5, which subsequently triggers the MAPK cascade, culminating in activation of MPK3/6 associated with an elevated innate immune response.

CPSF6-mediated XBP1 3'UTR shortening attenuates cisplatin-induced ER stress and elevates chemo-resistance in lung adenocarcinoma.

Alternative polyadenylation (APA) is a widespread mechanism generating RNA molecules with alternative 3' ends. Herein, we discovered that TargetScan includes a novel XBP1 transcript with a longer 3' untranslated region (UTR) (XBP1-UL) than that included in NCBI. XBP1-UL exhibited a lowered level in blood samples from lung adenocarcinoma (LUAD) patients and in those after DDP treatment. Consistently, XBP1-UL was reduced in A549 cells compared to normal BEAS-2B cells, as well as in DDP-treated/resistant A549 cells relative to controls. Moreover, due to decreased usage of the distal polyadenylation site (PAS) in 3'UTR, XBP1-UL level was lowered in A549 cells and decreased further in DDP-resistant A549 (A549/DDP) cells. Importantly, use of the distal PAS (dPAS) and XBP1-UL level were gradually reduced in A549 cells under increasing concentrations of DDP, which was attributed to DDP-induced endoplasmic reticulum (ER) stress. Furthermore, XBP1 transcripts with shorter 3'UTR (XBP1-US) were more stable and presented stronger potentiation on DDP resistance. The choice of proximal PAS (pPAS) was attributed to CPSF6 elevation, which was caused by BRCA1-distrupted R-loop accumulation in CPSF6 5'end. DDP-induced nuclear LINC00221 also facilitated CPSF6-induced pPAS choice in the pre-XBP1 3'end. Finally, we found that unlike the unspliced XBP1 protein (XBP1-u), the spliced form XBP1-s retarded p53 degradation to facilitate DNA damage repair of LUAD cells. The current study provides new insights into tumor progression and DDP resistance in LUAD, which may contribute to improved LUAD treatment.

Exosomal LOC85009 inhibits docetaxel resistance in lung adenocarcinoma through regulating ATG5-induced autophagy.

AIMS: This study aims at investigating the role of a neighbor long non-coding RNA (lncRNA) of HDAC4 (LOC85009) in docetaxel (DTX) resistance of lung adenocarcinoma (LUAD). METHODS: RT-qPCR was used to analyze LOC85009 expression in DTX-resistant LUAD cells. In vitro and in vivo experiments were applied to detect the influence of LOC85009 on LUAD cell growth and xenograft tumor growth. DNA pull down assay, RNA pull down assay, ChIP assay, CoIP assay and RIP assay were performed to identify the direct interactions between factors. RESULTS: LOC85009 was lowly-expressed in DTX-resistant LUAD cells. Functionally, LOC85009 overexpression inhibited DTX resistance and cell proliferation but triggered cell apoptosis. Moreover, we identified that LOC85009 was transferred from LUAD cells to DTX-resistant LUAD cells via exosomes. Exosomal LOC85009 inhibited DTX resistance, proliferation and autophagy while induced apoptosis in DTX-resistant cells. Additionally, we found that LOC85009 sequestered ubiquitin-specific proteinase 5 (USP5) to destabilize upstream transcription factor 1 (USF1) protein, thereby inactivating ATG5 transcription. CONCLUSIONS: Exosomal LOC85009 inhibits DTX resistance through regulation of ATG5-induced autophagy via USP5/USF1 axis, suggesting that LOC85009 might be a potential target to reverse DTX resistance in the treatment of LUAD.

MARCKSL1-2 reverses docetaxel-resistance of lung adenocarcinoma cells by recruiting SUZ12 to suppress HDAC1 and elevate miR-200b.

BACKGROUND: Long non-coding RNAs (lncRNAs) are implicated in the development of multiple cancers. In our previous study, we demonstrated that HDAC1/4-mediated silencing of microRNA-200b (miR-200b) enhances docetaxel (DTX)-resistance of human lung adenocarcinoma (LAD) cells. METHODS AND RESULTS: Herein, we probed the function of LncRNA MARCKSL1-2 (MARCKSL1-transcript variant 2, NR_052852.1) in DTX resistance of LAD cells. It was found that MARCKSL1-2 expression was markedly reduced in DTX-resistant LAD cells. Through gain- or loss- of function assays, colony formation assay, EdU assay, TUNEL assay, and flow cytometry analysis, we found that MARCKSL1-2 suppressed the growth and DTX resistance of both parental and DTX-resistant LAD cells. Moreover, we found that MARCKSL1-2 functioned in LAD through increasing miR-200b expression and repressing HDAC1. Mechanistically, MARCKSL1-2 recruited the suppressor of zeste 12 (SUZ12) to the promoter of histone deacetylase 1 (HDAC1) to strengthen histone H3 lysine 27 trimethylation (H3K27me3) of HDAC1 promoter, thereby reducing HDAC1 expression. MARCKSL1-2 up-regulated miR-200b by blocking the suppressive effect of HDAC1 on the histone acetylation modification at miR-200b promoter. Furthermore, in vivo analysis using mouse xenograft tumor model supported that overexpression of MARCKSL1-2 attenuated the DTX resistance in LAD tumors. CONCLUSIONS: We confirmed that MARCKSL1-2 alleviated DTX resistance in LAD cells by abolishing the inhibitory effect of HDAC1 on miR-200b via the recruitment of SUZ12. MARCKSL1-2 could be a promising target to improve the chemotherapy of LAD.

Adipose improves muscular atrophy caused by Sirtuin1 deficiency by promoting mitochondria synthesis.

Muscular dysplasia is a common muscle disease, but its pathological mechanism is still unclear. Adipose is originally identified as a highly conservative and widely expressed anti-obesity gene, and our previous study has reported that Adipose is also a positive regulator of myogenesis. Considering the vital role of during muscle development, this study was to demonstrate a potential relationship between Sirtuin1 and Adipose and clarified the mechanism by which Adipose regulated muscle development. Our results showed that the muscle fiber cross-sectional area and myosin heavy chain protein level were significantly reduced in Sirtuin1+/- mice. Moreover, the longitudinal section of muscle fibers was obviously irregular. Sirtuin1 knockdown significantly reduced the expression levels of Adipose and its upstream transcriptional regulator Kruppel like factor 15 and notably inhibited the AMP-activated protein kinase α-peroxisome proliferator-activated receptor gamma coactivator 1α signaling pathway in skeletal muscle. However, Adipose over-expression activated this signaling pathway and promoted mitochondrial biosynthesis in C2C12 myoblasts. Adipose over-expression also enhanced glucose absorption of C2C12 cells, suggesting the increased needs for cells for metabolic substrates. In C2C12 cells with hydrogen peroxide treatment, Adipose over-expression repressed hydrogen peroxide-elicited apoptosis and mitochondrial loss, while Sirtuin1-specific inhibitor dramatically weakened these roles of Adipose. Taken together, our findings reveal that Adipose rescues the adverse effects of Sirtuin1 deficiency or hydrogen peroxide on muscle development by activating the AMP-activated protein kinase α- peroxisome proliferator-activated receptor gamma coactivator 1α pathway to promote mitochondria synthesis, which provides theoretical basis for developing new therapeutic targets against some muscle diseases.

Molecular profiles and circulating tumor-DNA detected in Chinese early stage breast cancer.

Background: With the development of gene-sequencing technology, genome biomarkers, including Erb-B2 receptor tyrosine kinase 2 (ERBB2), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (pIK3CA), BReast CAncer gene 1 (BRCA1), and BReast CAncer gene 2 (BRCA2), and immunomarkers, including the tumor mutational burden (TMB) and programmed death-ligand 1 (PD-L1), have become important in the selection of treatment. Methods: Twenty patients with early stage breast cancer who underwent surgery were enrolled in this study. Tissue samples and paired postoperative peripheral blood samples were collected and subjected to the targeted-capture sequencing of 1,021 cancer-associated genes. Results: The most frequently altered genes were tumor protein 53 (TP53; 70%), PIK3CA (40%), protooncogene MYC (35%), ERBB2 (30%), and cyclin-dependent kinase 12 (CDK12; 20%). Six (30%) patients presented with ERBB2 amplification of NGS and simultaneously were positive for human epidermal growth factor receptor 2 (HER2) of IHC. ERBB2 amplification and being HER2 positive were common in breast cancer patients without lymph node metastasis (5/6, 83.3%) and those in stages IA-IIA. Most of the somatic mutations clustered in the TP53 pathway, followed by the PI3K pathway. The TMB was lower than metastatic breast cancer in our cohort, and ranged from 0 to 9.6 mut/Mb (median: 1.92 mut/Mb). Interestingly, more patients had the ERBB2 mutation in the non-lymph node metastasis group than the lymph node metastasis group (55.6% vs. 9.1%; P=0.049). Similarly, more patients had the CDK12 mutation in the non-lymph node metastasis group than the lymph node metastasis group (44.4% vs. 0%; P=0.026). Circulating tumor deoxyribonucleic acid (ctDNA) was detected in 7 of the 20 patients (35%). Of these patients, 71.4% (5/7) were in stage I/II. In addition, no correlation was found between ctDNA detection and clinicopathological features or the driver gene mutations (e.g., PIK3CA and ERBB2). However, patients positive for ctDNA had a higher TMB than those negative for ctDNA when grouped according to the median TMB (1.92 mut/Mb; 85.7% vs. 38.5%; P=0.043). Conclusions: This study described that genomic characteristics of Chinese early stage breast cancer, and the results showed that TMB was related to the detection of ctDNA in postoperative blood.

Characterization of the genomic landscape in large-scale Chinese patients with pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor with an extremely poor prognosis. Effective targets for anticancer therapy confirmed in PDAC are limited. However, the characteristics of genomics have not been fully elucidated in large-scale patients with PDAC from China. METHODS: We collected both blood and tissue samples from 1080 Chinese patients with pancreatic cancer and retrospectively investigated the genomic landscape using next-generation sequencing (NGS). FINDINGS: We found recurrent somatic mutations in KRAS (83.2%), TP53 (70.6%), CDKN2A (28.8%), SMAD4 (23.0%), ARID1A (12.8%) and CDKN2B (8.9%) in Chinese PDAC patients. Compared with primary pancreatic cancers, more genomic alterations accumulated especially cell cycle regulatory gene variants (45.4% vs 31.6%, P < 0.001) were observed in metastatic tumors. The most common mutation site of KRAS is p.G12D (43.6%) in pancreatic cancer. Patients with KRAS mutations were significantly associated with older age and mutations in the other three driver genes, while KRAS wild-type patients contained more fusion mutations and alternative mechanisms of RTK/Ras/MAPK pathway including a number of clinically targetable mutations. KRAS mutations in Chinese cohort were significantly lower than those in Western cohorts (all P < 0.05). A total of 252 (23.3%) patients with the core DNA damage response (DDR) gene mutations were detected. ATM (n =59, 5.5%) was the most frequent mutant DDR gene in patients with pancreatic cancer from China. Patients with germline DDR gene mutations were younger (P = 0.018), while patients with somatic DDR gene mutations were more likely to accumulate in metastatic lesions (P < 0.001) and had higher TMB levels (P < 0.001). In addition, patients with mutant DDR genes and patients carrying TP53 mutation were observed mutually exclusive (P < 0.001). INTERPRETATION: We demonstrated the real-world genomic characteristics of large-scale patients with pancreatic cancer from China which may have promising implications for further clinical significance and drug development. FUNDING: The funders are listed in the Acknowledgement.

sSTEAP4 regulates cellular homeostasis and improves high-fat-diet-caused oxidative stress in hepatocytes.

AIM: Nonalcoholic fatty liver disease (NAFLD) has become a global epidemic, but its pathogenesis is unclear. STEAP4, a member of six transmembrane protein family, integrates inflammatory and metabolic responses. Our present aim is to explore the roles of STEAP4 in maintaining cellular homeostasis and improving high-fat-diet (HFD)-caused oxidative stress in hepatocytes. MAIN METHODS: NAFLD model was established by HFD-feeding mice. The effects of over-nutrition on liver were detected by serum biochemical analysis and bulk RNA-seq. The levels of gene expression were measured by QPCR and Western Blot. Immunofluorescent staining was applied to determine the localization of STEAP4. AMPK agonist was employed to investigate the link between STEAP4 and AMPK pathway. KEY FINDINGS: Sus scrofa STEAP4 (sSTEAP4) relieved oxidative stress and rescued the viability of hepatocytes. sSTEAP4 increased AKT phosphorylation and SOD2 level in hepatocytes, whether or not treated with H2O2, suggesting sSTEAP4 has regulatory effects on insulin signaling and antioxidant pathways. However, sSTEAP4 inhibited AMPK phosphorylation and Beclin1/LC3 expression under H2O2-deficiency situation, but the results were conversed with H2O2 stimulation. The cellular ER stress was aggravated with the increased energy during oxidative stress, indicating that sSTEAP4 might regulate the energetic communication between ER and mitochondria by intervening mitochondrial energy production. In addition, sSTEAP4 was demonstrated to localize in the membranes of plasma and ER in HepG2 hepatocytes. SIGNIFICANCE: Our results reveal that sSTEAP4 based on the needs of cell itself to improve hepatic oxidative stress and HFD-caused NAFLD, which might provide a new therapeutic scheme for NAFLD.

Hispidin inhibits LPS-induced nitric oxide production in BV-2 microglial cells via ROS-dependent MAPK signaling.

Neuroinflammation is associated with many neurodegenerative diseases. Abnormal activation of microglial cells in the central nervous system (CNS) is a major characteristic of neuroinflammation. Nitric oxide (NO) free radicals are produced by activated microglia and prolonged presence of large quantities of NO in the CNS can lead to neuroinflammation and disease. Hispidin is a polyphenol derived from Phellinus linteus (a valuable medicinal mushroom) with strong antioxidant, anticancer and antidiabetic properties. A previous study demonstrated that hispidin significantly inhibited NO production via lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Therefore, the present study used MTT assay was used to detect the effect of hispdin on cell viability. Griess reagent analysis was used to measure NO production. Reverse transcription-semi quantitative PCR and western blotting were used to evaluate the effects of hispdin on iNOS mRNA and MAPK/ERK/JNK protein levels. Fluorescence microscopy and flow cytometry were used to detect the effects of hispdin on the production of ROS and phagocytosis of cells. The present results indicated that hispidin could significantly inhibit the increase of NO production and iNOS expression in BV-2 microglial cells stimulated by LPS. The inhibitory effect of hispidin on NO production was similar to that of S-methylisothiourea sulfate, an iNOS inhibitor. Signaling studies demonstrated that hispidin markedly suppresses LPS-induced mitogen activated protein kinases and JAK1/STAT3 activation, although not the NF-κB signaling pathway. The present observations in LPS-stimulated BV-2 microglial cells indicated that hispidin might serve as a therapeutic candidate for the treatment of NO-induced neuroinflammation and, potentially, as a novel iNOS inhibitor.

S-acylation of P2K1 mediates extracellular ATP-induced immune signaling in Arabidopsis.

S-acylation is a reversible protein post-translational modification mediated by protein S-acyltransferases (PATs). How S-acylation regulates plant innate immunity is our main concern. Here, we show that the plant immune receptor P2K1 (DORN1, LecRK-I.9; extracellular ATP receptor) directly interacts with and phosphorylates Arabidopsis PAT5 and PAT9 to stimulate their S-acyltransferase activity. This leads, in a time-dependent manner, to greater S-acylation of P2K1, which dampens the immune response. pat5 and pat9 mutants have an elevated extracellular ATP-induced immune response, limited bacterial invasion, increased phosphorylation and decreased degradation of P2K1 during immune signaling. Mutation of S-acylated cysteine residues in P2K1 results in a similar phenotype. Our study reveals that S-acylation effects the temporal dynamics of P2K1 receptor activity, through autophosphorylation and protein degradation, suggesting an important role for this modification in regulating the ability of plants in respond to external stimuli.

Curcumin Activates ROS Signaling to Promote Pyroptosis in Hepatocellular Carcinoma HepG2 Cells.

BACKGROUND/AIM: Curcumin is a polyphenol that exerts a variety of pharmacological activities and plays an anti-cancer role in many cancer cells. It was recently reported that gasdermin E (GSDME) is involved in the progression of pyroptosis. MATERIALS AND METHODS: HepG2 cells were treated with various concentrations of curcumin and cell viability was examined using MTT assay, apoptosis was analysed using flow cytometry, reactive oxygen species (ROS) levels using dihydroethidium, LDH release using an LDH cytotoxicity assay, and protein expression using western blot. RESULTS: Curcumin increased the expression of the GSDME N-terminus and proteins involved in pyrolysis, promoted HspG2 cell pyrolysis and increased intracellular ROS levels. Moreover, inhibition of the production of intracellular ROS with n-acetylcysteine (NAC) improved the degree of apoptosis and pyrolysis induced by curcumin. CONCLUSION: Curcumin induces HspG2 cell death by increasing apoptosis and pyroptosis, and ROS play a key role in this process. This study improves our understanding of the potential anti-cancer properties of curcumin in liver cancer.

CircZNF609 enhances hepatocellular carcinoma cell proliferation, metastasis, and stemness by activating the Hedgehog pathway through the regulation of miR-15a-5p/15b-5p and GLI2 expressions.

Emerging evidence has revealed that aberrantly expressed circular RNAs (circRNAs) play vital roles in tumorigenesis and progression of diverse human malignancies. Although an existing literature has elucidated the regulatory role of circZNF609 in breast cancer, the crucial function that circZNF609 exerted on hepatocellular carcinoma (HCC) remains unclear. Herein, we determined to explore the molecular mechanism of circZNF609 in HCC. In this study, circZNF609 was conspicuously overexpressed and featured with loop structure in HCC. Functional tests revealed that decreased expression of circZNF609 suppressed cell proliferation, metastasis and stemness, whereas induced cell apoptosis in HCC. Subsequent molecular mechanism assays indicated that circZNF609 contributed to HCC progression through activation of Hedgehog pathway. Moreover, circZNF609 was found to be negatively correlated with miR-15a-5p/15b-5p but positively correlated with GLI2. Moreover, there was a negative correlation between miR-15a-5p/15b-5p and GLI2. Rescue experiments testified that GLI2 overexpression could recover circZNF609 depletion-mediated function on HCC development while miR-15a-5p/15b-5p inhibition could partially rescue circZNF609 silencing-mediated effect on HCC progression. Final experiments in vivo further elucidated the suppressive function of circZNF609 knockdown on the tumorigenesis of HCC. Briefly, circZNF609 enhances HCC cell proliferation, metastasis, and stemness by activating the Hedgehog pathway through the regulation of miR-15a-5p/15b-5p and GLI2 expressions.

LncRNA ZFPM2-AS1 promotes lung adenocarcinoma progression by interacting with UPF1 to destabilize ZFPM2.

Lung adenocarcinoma (LUAD), a histological subclass of non-small-cell lung cancer, is globally the leading cause of cancer-related deaths. Long noncoding RNAs (lncRNAs) are emerging as cancer regulators. Zinc finger protein multitype 2 antisense RNA 1 (ZFPM2-AS1) is an oncogene in gastric cancer, but its functions have not been investigated in LUAD. We showed that ZFPM2-AS1 expression is high in LUAD samples based on GEPIA database (http://gepia.cancer-pku.cn/) and validated ZFPM2-AS1 upregulation in LUAD cell lines. Functionally, ZFPM2-AS1 facilitated proliferation, invasion, and epithelial-to-mesenchymal transition of LUAD cells. Thereafter, we found that ZFPM2 was negatively regulated by ZFPM2-AS1, and identified the suppressive effect of ZFPM2 regulation by ZFPM2-AS1 on LUAD progression. Mechanistically, we showed that ZFPM2-AS1 interacted with up-frameshift 1 (UPF1) to regulate mRNA decay of ZFPM2. Rescue assays in vitro and in vivo confirmed that ZFPM2-AS1 regulated LUAD progression and tumor growth through ZFPM2. Taken together, our findings demonstrate a role for the ZFPM2-AS1-UPF1-ZFPM2 axis in LUAD progression, suggesting ZFPM2-AS1 as a new potential target for LUAD treatment.

Exosome-transmitted circ_MMP2 promotes hepatocellular carcinoma metastasis by upregulating MMP2.

Exosomes released by tumor cells have been recently identified as important determinants of tumor progression. They often carry circular RNAs that are differentially expressed in tumors and may regulate tumorigenesis and metastasis. Here, we showed that supernatant of 97H hepatocellular carcinoma (HCC) cell line could promote metastasis in L02 human liver cells and HCC cell lines. Moreover, we determined that circ_MMP2 (has_circ_0039411) could be delivered by 97H- or LM3 cell-derived exosomes to L02 and HepG2 cell cultures. High expression of circ_MMP2 led to the upregulation of its host gene matrix metallopeptidase 2 (MMP2) via the sponging of miR-136-5p. Rescue assays demonstrated that miR-136-5p and MMP2 were two essential participants in HCC metastasis. Finally, high level of circ_MMP2 or MMP2, as well as low level of miR-136-5p, was correlated with low overall survival of HCC patients. Our study highlights a novel molecular pathway in HCC cell-derived exosomes.

PITPNA-AS1 abrogates the inhibition of miR-876-5p on WNT5A to facilitate hepatocellular carcinoma progression.

LncRNA PITPNA-AS1 was a newly identified lncRNA which has never been studied in cancers. Whether PITPNA-AS1 participated in the development of hepatocellular carcinoma (HCC) is obscure. Given the coaction of lncRNAs and miRNAs to carcinogenesis, the purpose of the present research is to inquire how PITPNA-AS1 affects HCC progression. Firstly, PITPNA-AS1 was observed to be heightened in HCC tissues. Then function assays proved that overexpressing or silencing PITPNA-AS1 could manipulate the proliferation and motility of HCC cells. Besides, PITPNA-AS1 was located in the cytoplasm. Among the candidate miRNAs of PITPNA-AS1, miR-876-5p was an obvious target. Moreover, mechanism experiments validated that PITPNA-AS1 modulated WNT5A expression by targeting miR-876-5p. Rescue experiments affirmed that WNT5A silencing rescued the miR-876-5p suppression-induced cellular processes in PITPNA-AS1-silenced Hep3B cells. And in vivo experiments determined that PITPNA-AS1 regulated HCC progression in vivo via miR-876-5p/WNT5A pathway. In conclusion, this work shed lights on the modulatory mechanism of PITPNA-AS1/miR-876-5p/WNT5A axis in HCC, which might be pivotal for exploring effective diagnostic biomarkers and treatment strategies for HCC patients.

FOX-A1 contributes to acquisition of chemoresistance in human lung adenocarcinoma via transactivation of SOX5.

BACKGROUND: Chemoresistance is a major obstacle for the effective treatment of lung adenocarcinoma (LAD). Forkhead box (FOX) proteins have been demonstrated to play critical roles in promoting epithelial-mesenchymal transition (EMT) and chemoresistance. However, whether FOX proteins contribute to the acquisition of EMT and chemoresistance in LAD remains largely unknown. METHODS: FOX-A1 expression was measured in LAD cells and tissues by qRT-PCR. The expression levels of EMT markers were detected by western blotting and immunofluorescence assay. The interaction between Sex determining region Y-box protein 5 (SOX5) and FOX-A1 was validated by chromatin immunoprecipitation sequence (ChIP-seq) and Chromatin immunoprecipitation (ChIP) assay. Kaplan-Meier analysis and multivariate Cox regression analysis were performed to analyze the significance of FOX-A1 and SOX5 expression in the prognosis of LAD patients. FINDINGS: FOX-A1 was upregulated in docetaxel-resistant LAD cells. High FOX-A1 expression was closely associated with a worse prognosis. Upregulation of FOX-A1 in LAD samples indicated short progression-free survival (PFS) and overall survival (OS). SOX5 is a new and direct target of FOX-A1 and was positively regulated by FOX-A1 in LAD cell lines. Knockdown of FOX-A1 or SOX5 reversed the chemoresistance of docetaxel-resistant LAD cells by suppressing cell proliferation, migration and EMT progress. INTERPRETATION: These data elucidated an original FOX-A1/SOX5 pathway that represents a promising therapeutic target for chemosensitizing LAD and provides predictive biomarkers for evaluating the efficacy of chemotherapies.

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.

HDAC3-mediated silencing of miR-451 decreases chemosensitivity of patients with metastatic castration-resistant prostate cancer by targeting NEDD9.

BACKGROUND: Treatment of metastatic castration-resistant prostate cancer (mCRPC) with docetaxel often fails due to the emergence of chemoresistance. Thus, restoring chemosensitivity to docetaxel-based therapies remains a challenge in mCRPC treatment. METHODS: microRNA (miR)-451 expression was measured in docetaxel-treated prostate cancer cells and tumor tissues by quantitative reverse-transcription polymerase chain reaction . Cell-counting kit 8 assay was performed to determine docetaxel chemoresistance. Neural-precursor-cell-expressed developmentally downregulated protein 9 (NEDD9) was identified as a novel target of miR-451 by dual-luciferase reporter system. Chromatin immunoprecipitation and co-immunoprecipitation assay were performed to confirm that histone deacetylase 3 (HDAC3)/Sp1 (a highly evolutionarily conserved transcription factor) interacted with the Sp1 binding sites in miR-451 promoter. RESULTS: miR-451 was found to be silenced in docetaxel-treated prostate cancer cells and mCRPC tissues. Low miR-451 expression was closely associated with a high Gleason score, high Eastern Cooperative Oncology Group performance status score, visceral metastasis and poor prognosis. Low expression of miR-451 was significantly correlated with short progression-free survival (PFS) and overall survival (OS) according to Kaplan-Meier analysis, and miR-451 was determined to be an independent poor prognostic factor for PFS and OS in mCRPC patients by univariate and multivariate Cox regression analyses. NEDD9 was identified as a new and functional target of miR-451. Restoration of NEDD9 partially reversed the effects of miR-451 on enhancing chemosensitivity of prostate cancer cells. HDAC3 was confirmed to be involved in silencing of miR-451 expression in prostate cancer cells. CONCLUSIONS: The current data revealed a new HDAC3/Sp1/miR-451/NEDD9 signaling axis that regulates the chemosensitivity of prostate cancer cells and represents a novel therapeutic target for chemosensitizing mCRPC.

Increased expression of lncRNA ZEB1-AS1 in non-small cell lung cancer is associated with poor prognosis.

BACKGROUND: Dysregulated long non-coding RNAs (lncRNAs) play critical roles in tumorigenesis and tumor progression. The purpose of this study was to investigate the relationship between lncRNA ZEB1-AS1 expression and non-small cell lung cancer (NSCLC) clinicopathological characteristics and prognosis. METHODS: Expression levels of lncRNA ZEB1-AS1 in 183 NSCLC specimens were determined by quantitative real-time PCR (qRT-PCR). To clarify the clinical significance of lncRNA ZEB1-AS1 in NSCLC, we further explored the relationship between lncRNA ZEB1-AS1 expression and overall survival (OS). RESULTS: In the present study, we found that lncRNA ZEB1-AS1 was upregulated in NSCLC tissues compared to adjacent non-tumor tissues. In addition, upregulated lncRNA ZEB1-AS1 expression was significantly associated with lymph node metastasis and TNM stage (P<0.05). Furthermore, patients with increased expression of lncRNA ZEB1-AS1 had poor OS (HR=3.202, 95% CI=2.018-5.078, P<0.001). Multivariate Cox proportional hazards model analysis demonstrated that high lncRNA ZEB1-AS1 expression was an independent poor prognostic factor for NSCLC patients. CONCLUSION: Our study suggests that increased expression of lncRNA ZEB1-AS1 is related to adverse prognosis of NSCLC and may be a new prognostic biomarker and potential therapeutic target for NSCLC intervention.