Programmed Cell Death Factor Research Articles

Knockdown of IGF2BP3 Down-Regulates PDCD4 Levels to Attenuate Hypoxic-Ischemic Brain Damage

Background: Hypoxic-ischemic brain damage (HIBD) is a prevalent brain injury with high mortality and morbidity. It results from hypoxia and ischemia of the brain due to various perinatal factors. A previous study showed that knockdown of programmed cell death factor 4 (PDCD4) could reduce infarction injury resulting from ischemia/reperfusion injury. However, exact mechanism by which PDCD4 acts in HIBD is not yet understood. Our aim in present investigation was to investigate the function and mechanism of PDCD4 in alleviating HIBD. Methods: An HIBD model was developed using neonatal rats. After 48 h of modeling, short-term neurological function was evaluated and the brain tissue removed for assessment of cerebral infarct volume and brain water content (BWC). A cell model of oxygen glucose deprivation/reoxygenation (OGD/R) was also constructed. Overexpression or knockdown of insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) or PDCD4 was performed in pretreated cells. Results: The geotaxis reflex time, cerebral infarct volume, and BWC all increased after HIBD in this neonatal rat model. Additionally, the levels of PDCD4 and of the N6-Methyladenosine (m6A) reader protein IGF2BP3 were increased in HIBD rats and OGD/R-stimulated pheochromocytoma (PC12) cells relative to controls. Moreover, OGD/R-stimulated pheochromocytoma PC12 cells showed decreased cell viability, increased apoptosis, and elevated Interleukin 6 (IL-6), Interleukin 1 β (IL-1β), and tumor necrosis factor-α (TNF-α) contents. These features were reversed after knocking down IGF2BP3. The interaction between IGF2BP3 protein and PDCD4 mRNA was confirmed by RNA immunoprecipitation and RNA pull-down assays. Furthermore, knockdown of IGF2BP3 in OGD/R-stimulated PC12 cells reduced cell damage via down-regulation of PDCD4. Finally, the IGF2BP3/PDCD4 axis alleviated OGD/R-induced cell injury in primary cortical neurons (PCNs). Conclusions: PDCD4 and m6A reader protein IGF2BP3 were up-regulated in an HIBD neonatal rat model. Knockdown of IGF2BP3 in OGD/R-stimulated PC12 cells or PCNs alleviated cell damage through reducing PDCD4.

PDCD4 promotes inflammation/fibrosis by activating the PPAR‑γ/NF‑κB pathway in mouse atrial myocytes.

Fibrosis is the basis of structural remodeling in atrial fibrillation (AF), during which inflammation is crucial. Programmed cell death factor 4 (PDCD4) is a newly identified inflammatory gene, with unknown mechanisms of action in AF. The present study aimed to elucidate the effects of PDCD4 on the inflammation and structural remodeling of atrial myocytes. For this purpose, a PDCD4 overexpression plasmid (oePDCD4) and PDCD4 small interfering (si)RNA (siPDCD4) were used to modulate PDCD4 expression in mouse atrial myocytes (HL‑1 cells). The expression of PDCD4 was detected using reverse transcription‑quantitative PCR and western blot analysis. The optimal drug concentrations of peroxisome proliferator‑activated receptor γ (PPARγ) agonist (pioglitazone hydrochloride), NF‑κB inhibitor (CBL0137), PPARγ inhibitor (GW9962) and NF‑κB agonist (betulinic acid) were screened using a Cell Counting Kit‑8 assay. The levels of inflammatory factors were detected using enzyme‑linked immunosorbent assays, the expression levels of fibrosis‑related proteins and NF‑κB subunits were detected using western blot analysis, and the expression of phosphorylated (p‑)p65/p65 was detected using immunofluorescence staining. The results revealed that PDCD4 overexpression increased the levels of fibrotic factors (collagen I, collagen III, fibronectin, α‑smooth muscle actin and matrix metalloproteinase 2), pro‑inflammatory cytokines (IFN‑γ, IL‑6, IL‑17A and TNF‑α) and p‑p65, whereas it reduced the levels of anti‑inflammatory cytokines (IL‑4) in HL‑1 cells. Additionally, treatment with the PPARγ agonist and NF‑κB inhibitor reversed the levels of fibrotic‑, pro‑inflammatory and anti‑inflammatory factors in oePDCD4‑HL‑1 cells. By contrast, PDCD4 silencing exerted the opposite effects on fibrotic factors, pro‑inflammatory cytokines, anti‑inflammatory cytokines and p‑p65. In addition, treatment with the PPARγ inhibitor and NF‑κB agonist reversed the levels of fibrotic‑, pro‑inflammatory and anti‑inflammatory factors in siPDCD4‑HL‑1 cells. In conclusion, the present study demonstrated that PDCD4 may induce inflammation and fibrosis by activating the PPARγ/NF‑κB signaling pathway, thereby promoting the structural remodeling of atrial myocytes in AF.

Programmed cell death factor 4-mediated hippocampal synaptic plasticity is involved in early life stress and susceptibility to depression

Early life stress (ELS) increases the risk of depression later in life. Programmed cell death factor 4 (PDCD4), an apoptosis-related molecule, extensively participates in tumorigenesis and inflammatory diseases. However, its involvement in a person’s susceptibility to ELS-related depression is unknown. To examine the effects and underlying mechanisms of PDCD4 on ELS vulnerability, we used a “two-hit” stress mouse model: an intraperitoneal injection of lipopolysaccharide (LPS) into neonatal mice was performed on postnatal days 7–9 (P7-P9) and inescapable foot shock (IFS) administration in adolescent was used as a later-life challenge. Our study shows that compared with mice that were only exposed to the LPS or IFS, the “two-hit” stress mice developed more severe depression/anxiety-like behaviors and social disability. We detected the levels of PDCD4 in the hippocampus of adolescent mice and found that they were significantly increased in “two-hit” stress mice. The results of immunohistochemical staining and Sholl analysis showed that the number of microglia in the hippocampus of “two-hit” stress mice significantly increased, with morphological changes, shortened branches, and decreased numbers. However, knocking down PDCD4 can prevent the number and morphological changes of microglia induced by ELS. In addition, we confirmed through the Golgi staining and immunohistochemical staining results that knocking down PDCD4 can ameliorate ELS-induced synaptic plasticity damage. Mechanically, the knockdown of PDCD4 exerts neuroprotective effects, possibly via the mediation of BDNF/AKT/CREB signaling. Combined, these results suggest that PDCD4 may play an important role in the ELS-induced susceptibility to depression and, thus, may become a therapeutic target for depressive disorders.

PDCD4 knockdown ameliorates lipopolysaccharide-induced endothelial cell damage by improving mitochondrial dynamics

To elucidate the role of programmed cell death factor 4 (PDCD4) in mitochondrial dysfunction caused by sepsis-related vascular endothelial damage. Cultured human umbilical vein endothelial cells (HUVECs) and mouse vascular endothelial cells (C166 cells) were transfected with a small interfering RNA targeting PDCD4 followed by treatment with lipopolysaccharide (LPS) alone or in combination with carbonyl cyanide 3-chlorophenylhydrazone (FCCP). The proteomic changes in the cells after PDCD4 knockdown were analyzed using LC-MS/MS technique. The mRNA expressions of PDCD4 and the genes associated with cell inflammation and apoptosis were detected with RT-PCR, and the expressions of FIS1, DRP1 and OPA1 proteins key to mitochondrial fission and fusion were determined using Western blotting. JC-1 and MitoSOX fluorescent probes were used to observe the changes in mitochondrial membrane potential and mitochondrial reactive oxygen species levels under by a laser confocal microscope. LPS stimulation of the cells significantly increased the mRNA expressions of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP1) and enhanced the cellular expression of PDCD4 (P < 0.05). Proteomic analysis suggested a correlation between PDCD4 knockdown and changes in mitochondrial dynamics in the cells. LPS treatment significantly increased the expressions of mitochondrial fission proteins FIS1 and DRP1 and lowered the expression of the fusion protein OPA1 in the cells (P < 0.05), causing also mitochondrial oxidative stress and reduction of the mitochondrial membrane potential (P < 0.05). In HUVECs, treatment with FCCP significantly attenuated the protective effect of PDCD4 knockdown, which inhibited LPS-induced inflammation and oxidative stress and restored the balance between mitochondrial fission and fusion. PDCD4 knockdown protects vascular endothelial cells against LPS-induced damages by repressing mitochondrial fission and oxidative stress, promoting mitochondrial fusion, and maintaining normal mitochondrial function.

Knockdown of programmed cell death factor 4 restores erectile function by attenuating apoptosis in rats with bilateral cavernous nerve crush injury.

Apoptosis is an important pathologic mechanism of erectile dysfunction after radical prostatectomy. Studies have shown that programmed cell death factor 4 is connected to the modulation of apoptosis in many cells. However, the programmed cell death factor 4 function in the cavernous nerve injury erectile dysfunction is unclear. This investigation aimed to explore the programmed cell death factor 4 function in erectile dysfunction in rats with bilateral cavernous nerve crush. The experiment used 30 male Sprague Dawley rats (18 months old) that were screened for normal erectile function by the apomorphine test. Ten rats were randomized into Sham and bilateral cavernous nerve crush groups to detect changes in programmed cell death factor 4 expression. The remaining 20 rats were distributed at random to four groups: the Sham group treated by sham surgery, the phosphate-buffered saline group, the lentivirus containing negative control short hairpin RNA group, and the lentivirus containing short hairpin RNA targeting programmed cell death factor 4 group underwent bilateral cavernous nerve crush and were afterward administered intracavernous injections of phosphate-buffered saline, lentivirus containing negative control short hairpin RNA, or lentivirus containing short hairpin RNA targeting programmed cell death factor 4. Electrical stimulation of the cavernous nerve was conducted 2 weeks later for penile erectile function assessment. The cavernous tissue was collected for histological analysis and western blotting. The apoptosis level in rat corpus cavernosum was elevated, and programmed cell death factor 4 expression was increased after bilateral cavernous nerve crush. Knockdown of programmed cell death factor 4 significantly improved erectile function in bilateral cavernous nerve crush rats. Furthermore, lentivirus containing short hairpin RNA targeting programmed cell death factor 4 treatment raised smooth muscle content and attenuated cavernous fibrosis and apoptotic levels. Additionally, programmed cell death factor 4 was found to mediate the PI3K/AKT pathway. Elevated programmed cell death factor 4 expression may be an important pathogenetic mechanism for erectile dysfunction after bilateral cavernous nerve crush, and the knockdown of programmed cell death factor 4 enhanced erectile function in 18-month-old rats after cavernous nerve damage. The potential mechanism may be the stimulation of the PI3K/AKT pathway to attenuate the cavernous apoptosis level.

Clinical Significance of Porphyromonas gingivalis Enriching Cancer Stem Cells by Inhibiting Programmed Cell Death Factor 4 in Esophageal Squamous Cell Carcinoma.

Studies have confirmed that the colonization of Porphyromonas gingivalis (Pg) could promote the malignant evolution of esophageal squamous cell carcinoma (ESCC). Since pathogenic microorganisms can promote malignant tumor proliferation by inhibiting programmed cell death factor 4 (PDCD4) and the decrease of PDCD4 activity can enhance the stemness of cancer cells, we here investigated the functional mechanism by which Pg promoted ESCC chemoresistance and malignancy through inhibiting PDCD4 and enriching cancer stem cells (CSCs). The effects of Pg and PDCD4 on CSCs, chemoresistance and malignancy of ESCC cells were evaluated by in vitro studies. The expression of Pg, PDCD4, and ALDH1 in ESCC tissues were detected by IHC, and the correlations between each index and postoperative survival of ESCC patients were analyzed. The results showed that Pg could inhibit PDCD4 expression and lead to CSCs enrichment in ESCC cells. After eliminating Pg, the expression of PDCD4 was upregulated, the percentage of CSCs, chemoresistance and malignancy were decreased. ESCC patients with Pg-positive, PDCD4-negative, and ALDH1-positive have a significant shorter survival. This study proved that eliminating Pg and blocking CSCs enrichment caused by decreasing PDCD4 activity may provide a new strategy for ESCC treatment.

Downregulation of PDCD4 through STAT3/ATF6/autophagy mediates MIF-induced PASMCs proliferation/migration and vascular remodeling

To address the molecular mechanisms underlying macrophage migration inhibitory factor (MIF) induced pulmonary artery smooth muscle cells (PASMCs) proliferation, migration and vascular remodeling in pulmonary hypertension (PH), primary cultured rat PASMCs and monocrotaline (MCT)-induced rats with PH were applied in the present study. The results showed that MIF increased signal transducer and activator of transcription 3 (STAT3) phosphorylation, and then stimulated activating transcription factor 6 (ATF6) activation, subsequently triggered autophagy activation, which further led to programmed cell death factor 4 (PDCD4) lysosomal degradation, and eventually promoted PASMCs proliferation/migration. In lung tissues of MCT rats, MIF protein expression was elevated, phosphorylation of STAT3 and activation of ATF6 were increased, activation of autophagy was evident, and reduction of PDCD4 was observed. Intervention with MIF inhibitor 4-Iodo-6-phenylpyrimidine (4-IPP), ATF6 blocker melatonin or autophagy inhibitor chloroquine, confirmed the in vitro interaction among MIF, STAT3, ATF6, autophagy and PDCD4 in MCT induced rats with PH. Targeting MIF/STAT3/ATF6/autophagy/PDCD4 axis effectively prevented the development of PH by suppressing PASMCs proliferation and vascular remodeling. In conclusions, we demonstrate that MIF activates the STAT3/ATF6/autophagy cascade and then degrades PDCD4 leading to PASMCs proliferation/migration and pulmonary vascular remodeling, suggesting that intervention this axis might have potential value in management of PH.

Orlistat /Gemfibrozil Ameliorate Testicular Dysfunction in Streptozotocin-Induced Diabetes in Rats via Targeting VEGF/ NO / Programmed Cell Death Factor 4 Signaling Pathways.

One of the complex chronic consequences of diabetes is testicular dysfunction, which is well-known yet still has a murky origin. Objective: With the aim of preventing testicular dysfunction in diabetic rats, we looked into the potential effects of orlistat and gemfibrozil on vascular endothelial growth factor (VEGF) as a marker of angiogenesis, nitric oxide (NO) as an oxidative stress marker, and programmed cell death factor 4 (PDCD4) as an apoptotic marker. Methods: Streptozotocin (STZ, 40 mg/kg/i.p. once) was used to induce diabetes in adult rats, and the treated groups received treatment started one week before induction. Rats were sacrificed three weeks later, and blood samples were obtained for hormonal analysis. Additionally, testicular tissue was examined for testicular oxidative stress, inflammatory markers, and apoptotic markers. Additionally, testicular VEGF and androgen receptors were evaluated, and testicular damage was identified. Results: The results revealed a notable decrease in PDCD4 signaling along with a considerable improvement in inflammatory markers, and oxidative stress status. Conclusion: Our data highlight the significance of VEGF/NO/ PDCD4 signaling pathways in the genesis of testicular dysfunction as a consequence of diabetes mellitus and point to the positive benefits of orlistat and gemfibrozil, either separately or in combination, in reducing testicular damage in diabetic rats.

Pan-Cancer Analysis on the Oncogenic Role of Programmed Cell Death 10.

Purpose Programmed cell death factor 10 (PDCD10) is associated with intercellular junction, cytoskeleton organization, cell proliferation, apoptosis, exocytosis, and angiogenesis. However, the role of PDCD10 in human cancer is unclear. This study aims to explore the role of PDCD10 in various tumors and its possible mechanism through bioinformatics analysis. Methods We verified the expression of the PDCD10 gene based on data from the ONCOMINE, TIMER2.0, and TISDB databases. The correlation of PDCD10 with prognosis of patients with different tumors was analyzed using data from the GEPIA2 database. Proteins bound to PDCD10 were analyzed from the STRING database. PDCD10, PDCD10-binding proteins, and associated candidate genes were analyzed in DAVID for functional and pathway analyses. We also evaluated the immunological, clinical, and genetic aspects of distinct cancers by using TIMER2.0 and the connection between PDCD10 expression and tumor immune subtypes by using TISDB. Single-cell sequencing data from the CancerSEA database were used to characterize cancer cell functional states and generate heat maps. Results PDCD10 overexpression is linked to certain molecular subtypes of human cancer. Low PDCD10 expression in patients with bladder urothelial carcinoma (BLCA), lung adenocarcinoma (LUAD), liver hepatocellular carcinoma (LIHC), adrenocortical carcinoma (ACC), head and neck squamous cell carcinoma (HNSC), kidney chromophobe carcinoma (KICH), brain lower grade glioma (LGG), pancreatic adenocarcinoma (PAAD), uterine corpus endometrial carcinoma (UCEC), oral squamous cell carcinoma (OSCC), and esophageal adenocarcinoma (ESAD) was correlated with favorable OS, whereas high PDCD10 expression in patients with LUSC, KIRC, READ, SKCM, and THYM was correlated with good prognosis. STRING network prediction results showed that 20 proteins, namely, paxillin (PXN), CCM2 scaffold protein (CCM2), TRAF3 interacting protein 3 (TRAF3IP3), FGFR1 oncogene partner 2 (FGFR1OP2), chromosome 4 open reading frame 19 (C4orf19), suppressor of IKBKE 1 (SIKE1), serine/threonine kinase 25 (STK25), striatin (STRN), protein phosphatase 2 catalytic subunit alpha (PPP2CA), mammalian sterile-20-like kinase 4 (MST4), MOB family member 4 (MOB4), protein phosphatase 2 scaffold subunit Abeta (PPP2R1B), sarcolemma-associated protein (SLMAP), serine/threonine kinase 24 (STK24), striatin 4 (STRN4), STRN3, protein phosphatase 2 scaffold subunit A alpha (PPP2R1A), striatin interacting protein 1 (STRIP1), CTTNBP2 N-terminal like (CTTNBP2NL), and cortactin binding protein 2 (CTTNBP2), can bind to PDCD10. Gene enrichment analysis suggested that PDCD10 is involved in the occurrence of different tumors through the Hippo signalling pathway, RNA transport, mRNA monitoring pathway, endocytosis, and T cell receptor signalling pathway. An inverse relationship was found between PDCD10 expression and cancer-associated fibroblasts in LUSC and TGCT, and PDCD10 expression was strongly connected with immunological subtypes, such as C1 (wound healing), C2 (interferon-gamma dominant), C3 (inflammation), C4 (lymphocyte depletion), C5 (immune silenced), and C6 (TGF-beta dominant). Finally, analysis of single-cell sequencing data revealed that PDCD10 expression is linked to epigenetic reprogramming, DNA repair, cell cycle progression, cell differentiation, inflammation, cell proliferation, cell differentiation, cell invasion, and angiogenesis. Conclusion The results of our investigation demonstrate that PDCD10 has an oncogenic function in many cancer types. This study provides a reference for future research on antitumor therapeutic targets.

MiR-21 inhibits the proliferation of childhood cholesteatoma glioma cells by negatively regulating the expressions of PTEN and PDCD4

&#x0D; &#x0D; &#x0D; &#x0D; Purpose: To determine the effect of MiR-21 on the proliferation of glioma cells in children with cholesteatoma, and the pathway involved.&#x0D; Methods: Cholesteatoma tissues from children with cholesteatoma in Otology Department of our hospital were isolated, extracted and cultured in serum-free medium of keratinocytes. The experiment comprised three groups: negative control group, blank control group and miR-21 inhibition group. Cell cycle and cell proliferation were analyzed. mRNA and protein expressions of phosphatase tension homologue (PTEN) and programmed cell death factor-4 (PDCD4) were determined.&#x0D; Results: The proliferation of CK cells in miR-21 group was significantly lower than that in negative control and blank control groups (p &lt; 0.05). The proportion of CK cells at G0/G1 phase in miR-21 inhibition group was significantly higher than those in negative control and blank control groups (p &lt; 0.05). The protein and mRNA expression levels of PTEN and PDCD4 in CK in miR-21 group were significantly higher than those in negative control and blank control groups (p &lt; 0.05).&#x0D; Conclusion: Inhibition of miR-21 slows down cell proliferation to some extent, and induces apoptosis of cholesteatoma cells by inducing cell cycle arrest at G0/G1 phase via a mechanism linked to the negative regulation of expressions of PTEN and PDCD4. Thus, MiR-21 can be used as potential target for the drug of treatment of children with cholesteatoma.&#x0D; &#x0D; &#x0D; &#x0D;

PDCD4 Simultaneously Promotes Microglia Activation via PDCD4-MAPK-NF-κB Positive Loop and Facilitates Neuron Apoptosis During Neuroinflammation.

Neuroinflammation and neuron injury are common features of the central nervous system (CNS) diseases. It is of great significance to identify their shared key regulatory molecules and thus explore the potential therapeutic targets. Programmed cell death factor 4 (PDCD4), an apoptosis-related molecule, extensively participates in tumorigenesis and inflammatory diseases, but its expression and biological function during CNS neuroinflammation remain unclear. In the present study, utilizing the lipopolysaccharide (LPS)-induced neuroinflammation model in mice, we reported an elevated expression of PDCD4 both in injured neurons and activated microglia of the inflamed brain. A similar change in PDCD4 expression was observed in vitro in the microglial activation model. Silencing PDCD4 by shRNA significantly inhibited the phosphorylation of MAPKs (p38, ERK, and JNK), prevented the phosphorylation and nuclear translocation of NF-κB p65, and thus attenuated the LPS-induced microglial inflammatory activation. Interestingly, LPS also required the MAPK/NF-κB signaling activation to boost PDCD4 expression in microglia, indicating the presence of a positive loop. Moreover, a persistent elevation of PDCD4 expression was detected in the H2O2-induced neuronal oxidative damage model. Knocking down PDCD4 significantly inhibited the expression of pro-apoptotic proteins BAX and Cleaved-PARP, suggesting the proapoptotic activity of PDCD4 in neurons. Taken together, our data indicated that PDCD4 may serve as a hub regulatory molecule that simultaneously promotes the microglial inflammatory activation and the oxidative stress-induced neuronal apoptosis within CNS. The microglial PDCD4-MAPK-NF-κB positive feedback loop may act as pivotal signaling for neuroinflammation which subsequently exaggerates neuronal injury, and thus may become a potential therapeutic target for neuroinflammatory diseases.

Exosomal miR-208b related with oxaliplatin resistance promotes Treg expansion in colorectal cancer

Oxaliplatin resistance is a challenge in the treatment of colorectal cancer (CRC) patients. Regulatory T cells (Tregs) are well known for their immunosuppressive roles, and targeting Tregs is an effective way to improve chemosensitivity. Exosome-delivered microRNA (miRNA) might be used as a potential biomarker for predicting chemosensitivity. However, the relationship between Tregs and exosomal miRNAs remains largely unknown. TaqMan low-density array was performed to screen the differentially expressed serum miRNAs from pooled serum of patients who had FOLFOX treatment. Differential expression was validated using qRT-PCR in individual samples. Exosomes were isolated by sequential differential centrifugation, and they were verified by transmission electron microscopy. The RNA and protein levels were determined by quantitative real-time PCR and western blotting. A mouse xenograft model was adopted to evaluate the correlation between exosome-derived miR-208b and Tregs in vivo. We demonstrated that circulating miR-208b is a non-invasive marker for predicting FOLFOX sensitivity in CRC. miR-208b in colon cancer was secreted by tumor cells in the pattern of exosomes, and oxaliplatin-resistant cells showed the most obvious phenomenon of miR-208b increase. Colon cancer cell-secreted miR-208b was sufficiently delivered into recipient T cells to promote Treg expansion by targeting programmed cell death factor 4 (PDCD4). Furthermore, in vivo studies indicated that Treg expansion mediated by cancer cell-secreted miR-208b resulted in tumor growth and oxaliplatin resistance. Our results demonstrate that tumor-secreted miR-208b promotes Treg expansion by targeting PDCD4, and it may be related to a decrease of oxaliplatin-based chemosensitivity in CRC. These findings highlight a potential role of exosomal miR-208b as a predictive biomarker for oxaliplatin-based therapy response, and they provide a novel target for immunotherapy.

MicroRNA-183-5p contributes to malignant progression through targeting PDCD4 in human hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) remains one of the most common malignant tumors worldwide. The present study aimed to investigate the biological role of microRNA-183-5p (miR-183-5p), a novel tumor-related microRNA (miRNA), in HCC and illuminate the possible molecular mechanisms. The expression patterns of miR-183-5p in clinical samples were characterized using qPCR analysis. Kaplan–Meier survival curve was applied to evaluate the correlation between miR-183-5p expression and overall survival of HCC patients. Effects of miR-183-5p knockdown on HCC cell proliferation, apoptosis, migration and invasion capabilities were determined via Cell Counting Kit-8 (CCK8) assays, flow cytometry, scratch wound healing assays and Transwell invasion assays, respectively. Mouse neoplasm transplantation models were established to assess the effects of miR-183-5p knockdown on tumor growth in vivo. Bioinformatics analysis, dual-luciferase reporter assays and rescue assays were performed for mechanistic researches. Results showed that miR-183-5p was highly expressed in tumorous tissues compared with adjacent normal tissues. Elevated miR-183-5p expression correlated with shorter overall survival of HCC patients. Moreover, miR-183-5p knockdown significantly suppressed proliferation, survival, migration and invasion of HCC cells compared with negative control treatment. Consistently, miR-183-5p knockdown restrained tumor growth in vivo. Furthermore, programmed cell death factor 4 (PDCD4) was identified as a direct target of miR-183-5p. Additionally, PDCD4 down-regulation was observed to abrogate the inhibitory effects of miR-183-5p knockdown on malignant phenotypes of HCC cells. Collectively, our data suggest that miR-183-5p may exert an oncogenic role in HCC through directly targeting PDCD4. The current study may offer some new insights into understanding the role of miR-183-5p in HCC.

LncRNA HAND2-AS1 inhibits 5-fluorouracil resistance by modulating miR-20a/PDCD4 axis in colorectal cancer

BackgroundChemoresistance is one of the main obstacles in the therapy of human cancers, including colorectal cancer (CRC). Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (lncRNA HAND2-AS1) has been demonstrated to be associated with CRC. However, the function of HAND2-AS1 in 5-Fluorouracil (5-FU) resistance of CRC remains unclear. MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression of HAND2-AS1, miR-20a and programmed cell death factor 4 (PDCD4) mRNA. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was conducted to evaluate IC50 of 5-FU and cell proliferation. Flow cytometry analysis was used to determine cell apoptosis. Transwell assay was carried out to measure cell migration and invasion. Western blot assay was conducted to examine the protein levels of B-cell lymphoma-2 (Bcl-2), BCL2-Associated X (Bax), matrix metalloprotein 2 (MMP2), MMP9 and PDCD4. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull down assay were utilized to verify the combination between miR-20a and HAND2-AS1. Dual-luciferase reporter assay was used to analyze the association between miR-20a and PDCD4. Murine xenograft assay was used to confirm the function of HAND2-AS1 in vivo. ResultsHAND2-AS1 and PDCD4 were downregulated and miR-20a was upregulated in 5-FU-resistant CRC tissues and cells. HAND2-AS1 suppressed 5-FU resistance, cell proliferation, migration and invasion and promoted cell apoptosis in 5-FU-resistant CRC cells. HAND2-AS1 acted as a sponge of miR-20a to regulate PDCD4 expression. Moreover, HAND2-AS1 suppressed cell progression and 5-FU resistance by upregulating PDCD4 via sponging miR-20a in 5-FU-resistant CRC cells. Besides, HAND2-AS1 inhibited tumor growth in vivo. ConclusionHAND2-AS1/miR-20a/PDCD4 axis inhibited cell progression and 5-FU resistance in 5-FU-resistant CRC cells.

PDCD4 enhances the inhibitory effect of As(2)O(3) on the growth and NF-κB signaling pathway in neuroblastoma cells

Objective: To investigate the inhibitory effect of programmed cell death factor 4 (PDCD4) on arsenic trioxide (As(2)O(3))-induced cell growth and nuclear factor kappa B (NF-κB) signaling pathway in neuroblastoma. Methods: The PDCD4 overexpression vector was transfected into neuroblastoma cells and detected by fluorescence quantitative PCR and Western blot. As(2)O(3) was used to treat PDCD4 overexpressing neuroblastoma cells. MTT assay was used to measure the proliferation. Colony formation assay was used to determine the cell clone forming ability. Apoptosis was measured by flow cytometry. Western blot was used to detect the expression of NF-κB p65 and cleaved caspase-3 protein in cells. Results: The transfection of PDCD4 overexpression vector significantly increased the expression level of PDCD4 in neuroblastoma cells. The cell survival rates of the control group, PDCD4 group, As(2)O(3) group and As(2)O(3)+ PDCD4 group were 100%, (72.14±5.20)%, (62.58±3.14)% and (40.87±2.47)%, respectively. The colony formation rates in these four groups were (91.25±8.36)%, (65.32±7.14)%, (57.23±5.28)% and (37.14±3.64)%, respectively. In addition, the cell apoptotic rates of these four groups were (3.57±0.24)%, (28.64±3.20)%, (36.41±4.58)% and (49.65±5.27)%, respectively. Therefore, overexpression of PDCD4 in the absence or presence of As(2)O(3) inhibited cell proliferation and clone formation ability, while promoted apoptosis. Furthermore, the expression levels of cleaved caspase-3 in the control group, PDCD4 group, As(2)O(3) group and As(2)O(3)+ PDCD4 group were 0.21±0.03, 0.30±0.02, 0.43±0.05 and 0.57±0.06, respectively. And the expression levels of NF-κB p65 protein were 0.68±0.04, 0.52±0.03, 0.43±0.04, and 0.32±0.02, respectively. Compared with the control group, the expression levels of NF-κB p65 protein in PDCD4 group, As(2)O(3) group and As(2)O(3)+ PDCD4 group were significantly decreased (P<0.05), whereas the expression level of cleaved Caspase-3 protein was significantly increased (P<0.05). The changes in As(2)O(3)+ PDCD4 group were more significant than those in PDCD4 group and As(2)O(3) groups (both P<0.05). Conclusion: PDCD4 enhances the inhibitory effect of As(2)O(3) on the growth and NF-κB signaling pathway in neuroblastoma cells.

Effects of Tumor Necrosis Factor Alpha on the Expression of Programmed Cell Death Factor 5 in Arthritis.

ObjectiveTo investigate the effect of tumor necrosis factor alpha (TNF‐α) on the proliferation of fibroblast‐like synoviocytes (FLS) and the expression of programmed cell death factor 5 (PDCD5) in an inflammatory microenvironment, for the further understanding of the mechanism of action of TNF‐α in promoting the proliferation of synovial cells and the apoptosis of the chondrocytes.MethodsArticular carriage specimens were obtained from 21 cases with osteoarthritis and 12 cases with femoral neck fractures as healthy controls during arthroplasties. The expression of PDCD5 was evaluated by immunofluorescence analyzed by mean option density (MOD) detected using the software ImagePro Plus. Real‐time PCR was performed to evaluate the transcriptions of PDCD5 and TNF‐α in synovium. FLS cells derived from rheumatoid arthritis patients were cultured in vitro and incubated with different concentrations of TNF‐α. The effects of TNF‐α at different concentrations on the proliferation of FLS cells were detected by Cell Counting Kit‐8 (CCK‐8) assay to evaluate the cell proliferation rate. After incubation with the absence or presence of recombinant human TNF‐α at different concentrations, the FLS cells were isolated for detection of PDCD5 protein and PDCD5 gene. The expression of PDCD5 protein was detected by western‐blot and the transcription of PDCD5 gene from the cells was detected by real‐time quantitative PCR.ResultsThe MOD of PDCD5 as well as TNF‐α of osteoarthritis cartilage sections were significantly increased compared with those of the controls, and in synovium there was a positive correlation between transcriptions of their mRNA. When the concentration of TNF‐α was 1 ng/mL, the cell proliferation rate was not significantly different from that of the control group (P = 0.592), while the proliferation of FLS cells was significantly promoted when the concentration of TNF‐α was 5, 10, 15, or 20 ng/mL, and the proliferation‐promoting rates were 35.64% ± 6.96%, 48.72% ± 7.69%, 45.60% ± 8.85%, and 39.32% ± 6.18%, respectively (P < 0.01). The transcription of PDCD5 gene was significantly downregulated, which was 80.44% ± 4.07% and 84.30% ± 5.48%, respectively (P < 0.05), in the FLS cells incubated with TNF‐α at the concentration of 10 and 15 ng/mL for 24 h. When the concentration of TNF‐α was 1, 5, or 20 ng/mL, the transcription of PDCD5 mRNA in FLS cells was not significantly different from that in the control group (P > 0.05). The expression of PDCD5 protein was only significantly downregulated when the concentration of TNF‐α was 10 ng/mL (P < 0.01), while the expression of PDCD5 protein in FLS cells was not significantly different from that in the control group (P > 0.05).ConclusionThe expression of PDCD5 as well as TNF‐α in osteoarthritis cartilage and synovium was significantly higher than in healthy tissues, and TNF‐α can promote the proliferation of FLS cells in patients with rheumatoid arthritis, and inhibit the expression of PDCD5. PDCD5 may be involved in the abnormal proliferation of synoviocytes and the degeneration of chondrocytes stimulated by TNF‐α.

Programmed cell death factor 4 enhances the chemosensitivity of colorectal cancer cells to Taxol.

Drug resistance and disease relapse are still challenging problems in the chemotherapy of colorectal cancer (CRC). Programmed cell death factor 4 (PDCD4) has previously been reported to act as a tumor suppressor and was implicated in the chemosensitivity of numerous types of human malignancy. In this study, the effect of PDCD4 in the sensitivity of CRC to the chemotherapy drug Taxol was investigated. The results confirmed that lower PDCD4 expression was present in CRC tumor tissues, when compared with in normal adjacent tissues (p) and closely associated with the prognosis of patients with CRC. Upregulation of PDCD4 significantly enhanced the sensitivity of CRC cells to Taxol, by partially contributing to pro-apoptosis and anti-invasion pathways, both through upregulation of the apoptosis-associated protein Bax, and downregulation of the anti-apoptosis protein Bcl-2 and invasion-associated proteins MMP-9. These findings might present a novel strategy for sensitizing tumor cells to apoptosis and, thus, overcoming chemotherapy resistance in CRC.

The expression and clinical significance of PDCD4 and Her-2 in human gastric cancer

To investigate the correlation and clinical significance between programmed cell death factor 4 (PDCD4) and epidermal growth factor receptor 2 (Her-2) expressions and clinicopathological parameters in patients with gastric cancer, a total of 65 cases of gastric cancer and the corresponding normal mucosa with PDCD4 and Her-2 protein expressions were detected by SP immunohistochemical staining, and 50 cases of gastric cancer and the corresponding normal mucosa with PDCD4 and Her-2 protein expression quantities were detected by Western blot, in order to analyze the relationship between the positive expressions of PDCD4 and Her-2 protein and the clinicopathological features of patients with gastric cancer. The results showed that the positive rate of PDCD4 protein expression in gastric cancer tissues was 7.7%, which was significantly lower than that in the corresponding normal tissues, that is, 77.5% ( P &lt; 0.05); the positive rate of Her-2 expression was 41.5%, which was significantly higher than that of the corresponding normal tissues, which is 2.5% ( P &lt; 0.05). The Western blot test showed that the expression of PDCD4 protein in gastric cancer was 0.3105 ± 0.0073, which was significantly lower than that in the corresponding normal tissues, that is, 0.9428 ± 0.0127 ( P &lt; 0.05); the expression level of Her-2 protein in gastric cancer tissues was 0.9428 ± 0.0127, which was significantly higher than that of the corresponding normal mucosa, which is 0.2054 ± 0.0264 ( P &lt; 0.05). The positive expressions of PDCD4 (5/65) and Her-2 (27/65) were significantly correlated with the differentiation degrees and TNM stages of gastric cancer ( P &lt; 0.05). However, no significant correlation can be observed from Table 2 ( P &gt; 0.05), regarding sex, age, tumor size, and lymph node metastasis. Our research claimed that PDCD4 and Her-2 may play an important role in the invasion and metastasis of gastric cancer, which has a negative correlation with biological behaviors of gastric cancer. The low expression of PDCD4 and the high expression of Her-2 in gastric cancer may promote the occurrence and progression of cancer. The PDCD4 and Her-2 test can be used as an index to evaluate the malignant biological behaviors of gastric cancer and prognosis, and provide a theoretical basis for targeted therapy.

Abstract 4580: Improved quality of life and tumor regression in a patient with stage IV non-small cell lung cancer with brain metastasis 10 months after daily treatment with single agent mifepristone

Abstract The FDA granted an IND for a 40 patient study entitled “A phase II study of treatment with oral mifepristone as salvage therapy in patients with advanced or metastatic non-small cell lung cancer who have failed 2 or more previous chemotherapy or immunotherapy regimens”. Presented herein is a description of the effect of treating Case 1 who is a 68 year old male who presented with stage IV non-small cell lung cancer with brain metastasis causing seizures following 10 months of treatment with single agent oral mifepristone (Korlym from Corcept Inc) 300mg qd. He had shown tumor progression despite treatment with carboplatin, docetaxel, premetrexed, and gemcitabine. He was not considered a candidate for nivolumab or pembrolizumab because his tumor was negative for the programmed cell death factor ligand 1 (PD-L-1) marker. His preclinical performance status was ECOG 1. After 2 months of daily 300mg mifepristone treatment he showed a considerable improvement in energy and stamina and less shortness of breath. There have been no new lung or brain lesions. In fact, there has been shrinkage of the lung lesions and no growth of the brain lesion and no more seizures. His ECOG was “0” after 10 months of single agent mifepristone treatment. The mechanism of action is believed to be by suppressing intracytoplasmic production of an immunomodulatory protein known as the progesterone induced blocking factor (PIBF). One of the functions of PIBF is to stabilize perforin granules in natural killer cells thus inhibiting their cytotoxic activity. This protein seems to be unique to rapidly growing cells, e.g., trophoblast cells or cancer cells. Thus, in general, in low dosages, as used in this patient, the drug is very well tolerated. PIBF does not seem to be needed for cells growing at normal speed. In humans, mifepristone has been found to either cause complete tumor regression, or more commonly, stabilization of the cancer with improved quality of life. Previously, mifepristone allowed long-term complete remission from a terminal small cell lung cancer with associated hyponaotremia. The case reported here is believed the first involving palliative benefit of treating advanced non-small cell lung cancer with mifepristone. Stabilization of the brain metastasis in this report supports evidence from a previous case of advanced glioblastoma multiforme with a clear though transient response to mifepristone, that the drug can cross the blood-brain barrier, and thus be effective for brain lesions. This is the first case treated with 300mg daily mifepristone (200mg used previously). Similar to the lower dosage, this patient reported no adverse side effects. Mifepristone was also found to improve longevity and body conditioning scores in a placebo controlled study of spontaneous murine lung cancer. Citation Format: Jerome H. Check, Diane Check, Mahmoud Aly, Patricia Lofberg, Rachael Cohen, Dwight McKee. Improved quality of life and tumor regression in a patient with stage IV non-small cell lung cancer with brain metastasis 10 months after daily treatment with single agent mifepristone [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4580. doi:10.1158/1538-7445.AM2017-4580

Influence of microRNA-155 and microRNA-21 on expression of Toll-like receptor 4 in children with sepsis

Objective To discuss the influence of microRNA(miR)-155/miR-21 on toll-like receptor 4 (TLR4) in children with sepsis. Methods Fifty children with sepsis who were hospita-lized in Pediatric Intensive Care Unit, Shenzhen Children′s Hospital, were enrolled in the study, and 15 healthy children at the same age were selected as healthy control group.Expression levels of TLR4 protein and human leukocyte antigen(HLA)-DR in CD14＋ monocytes (MC) were detected by using flow cytometry, and sepsis patients were divided into 2 groups according to whether they exceeded the value of HLA-DR by 30% or not.Expression level of programmed cell death factor 4 (PDCD4) and inositol phosphatases 1 containing SH2 (SHIP1) were detected at the same time.MC were separated by CD14＋ immune magnetic bead, and expression level of miR-155, miR-21 and tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) mRNA in CD14＋ MC were detected by using real-time fluorescent quantitative PCR. Results Sepsis group consisted of 27 male and 23 female, and their ages were (2.34±0.79) years old, among whom 9 patients died.There were 36 patients in the HLA-DR increase group and 14 patients in the HLA-DR decrease group.Expressions of TLR4(2.33±0.90), miR-155[(7.19±3.75)×10-3] and TNF-α[(21.98±14.15)×10-2 μg/L] in CD14＋ MC were higher in the HLA-DR increase group than those in the HLA-DR decrease group[1.24±0.60, (4.83±1.17) ×10-3, (14.18±5.45)×10-2 μg/L] and healthy control group[1.57±0.55, (3.99±1.29)×10-3, (1.61±0.84)×10-2 μg/L], and the differences were statistically significant(F=11.943, 7.583, 18.538, all P<0.05), while the expressions of miR-21(12.10±5.66), IL-10[(29.74±12.55)×10-4 μg/L] in CD14＋ MC were lower in the HLA-DR increase group than those in the HLA-DR decrease group[4.68±2.07, (12.50±5.73)×10-4 μg/L] and healthy control group [2.39±0.86, (2.04±0.92)×10-4 μg/L], and the differences were statistically significant(F=41.673, 54.991, all P<0.05). The levels of SHIP1 and PDCD4 decreased in sepsis compared with healthy control group[0.70±0.36)vs.(1.59±0.48); (1.55±0.56) vs.(3.01±0.70)], and the differences were statistically significant (t=7.682, 8.339, all P<0.05), but SHIP1 decreased more significantly in the HLA-DR increase group than that in the HLA-DR decrease group[(0.60±0.34) vs.(0.97±0.26)], and the difference was statistically significant(F=39.214, P<0.05). PDCD4 decreased more significantly in the HLA-DR decrease group than that in the HLA-DR increase group (0.94±0.19 vs.1.79±0.47), the difference was statistically significant(F=65.367, P<0.05). Conclusions Regulation imbalance of miR-155/miR-21 may be one of the reasons for abnormal expression of TLR4 in children with sepsis, and it plays a role in enlarged or inhibited expression of TLR4 in the sepsis process which results in different immune status in sepsis patients. Key words: Child; microRNA-155; microRNA-21; Sepsis; Monocytes