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The long-term prognosis of breast cancer with metastasis remains extremely poor. Genetic alterations in tumor cells result in cellular heterogeneity, promoting cancer cells invasion and colonization in some organs during the metastatic process. CircRNAs are very promising as critical biological markers and precise diagnoses in identifying disease mechanisms and developing new methods for effective treatment. However, the role of aberrant expression of circRNAs in breast cancer progression remains largely unknown.RNase R treatment and quantitative RT-PCR (qRT-PCR) were performed for circRNA detection. Transwell chamber assays were used to examine the chemotactic migration and invasion of breast cancer cells.This study identified and characterized the circRAD54L2 originating from exon 1, 2, 3, and 4 of the RAD54L2 gene. Importantly, we found that circRAD54L2, rather than RAD54L2 linear mRNA, was significantly upregulated in breast cancer cell lines. Furthermore, we found that inhibiting circRAD54L2 expression markedly reduced the invasion, metastasis, and proliferation of breast cancer cells via sponging of the miR-888 family, which downregulated the expression of pyruvate dehydrogenase kinase 1 (PDK1).Our results showed that circRAD54L2 could regulate PDK1 expression by sponging the miR-888 family competing for the ceRNA mechanism, indicating that circRAD54L2 may act as an essential upstream regulator and providing further mechanistic evidence to support the notion that circRAD54L2/miR-888s/PDK1 is a promising therapeutic target in the treatment of breast cancer.

The abnormal PI3K/AKT/mTOR pathway is one of the most common genomic abnormalities in breast cancers including triple-negative breast cancer (TNBC), and pharmacologic inhibition of these aberrations has shown activity in TNBC patients. Here, we designed and identified a small-molecule Comp34 that suppresses both AKT and mTOR protein expression and exhibits robust cytotoxicity towards TNBC cells but not nontumorigenic normal breast epithelial cells. Mechanically, long noncoding RNA (lncRNA) AL354740.1-204 (also named as NUDT3-AS4) acts as a microRNA sponge to compete with AKT1/mTOR mRNAs for binding to miR-99s, leading to decrease in degradation of AKT1/mTOR mRNAs and subsequent increase in AKT1/mTOR protein expression. Inhibition of lncRNA-NUDT3-AS4 and suppression of the NUDT3-AS4/miR-99s association contribute to Comp34-affected biologic pathways. In addition, Comp34 alone is effective in cells with secondary resistance to rapamycin, the best-known inhibitor of mTOR, and displays a greater in vivo antitumor efficacy and lower toxicity than rapamycin in TNBC xenografted models. In conclusion, NUDT3-AS4 may play a proproliferative role in TNBC and be considered a relevant therapeutic target, and Comp34 presents promising activity as a single agent to inhibit TNBC through regulation of NUDT3-AS4 and miR-99s.

Rationale: Skeletal muscle insulin resistance is detectable before type 2 diabetes is diagnosed. Exposure to di(2-ethylhexyl) phthalate (DEHP), a typical environmental endocrine-disrupting chemical, is a novel risk factor for insulin resistance and type 2 diabetes. This study aimed to explore insulin signaling regulatory pathway in skeletal muscle of the DEHP-induced insulin-resistant mice and to investigate potential therapeutic strategies for treating insulin resistance. Methods: C57BL/6J male mice were exposed to 2 mg/kg/day DEHP for 15 weeks. Whole-body glucose homeostasis, oxidative stress and deregulated miRNA-mediated molecular transduction in skeletal muscle were examined. microRNA (miRNA) interventions based on lentiviruses and adeno-associated viruses 9 (AAV9) were performed. Results: Dnmt3a-dependent promoter methylation and lncRNA Malat1-related sponge functions cooperatively downregulated miR-17 in DEHP-exposed skeletal muscle cells. DEHP suppressed miR-17 to disrupt the Keap1-Nrf2 redox system and to activate oxidative stress-responsive Txnip in skeletal muscle. Oxidative stress upregulated miR-200a, which directly targets the 3'UTR of Insr and Irs1, leading to hindered insulin signaling and impaired insulin-dependent glucose uptake in skeletal muscle, ultimately promoting the development of insulin resistance. AAV9-induced overexpression of miR-17 and lentivirus-mediated silencing of miR-200a in skeletal muscle ameliorated whole-body insulin resistance in DEHP-exposed mice. Conclusions: The miR-17/Keap1-Nrf2/miR-200a axis contributed to DEHP-induced insulin resistance. miR-17 is a positive regulator, whereas miR-200a is a negative regulator of insulin signaling in skeletal muscle, and both miRNAs have the potential to become therapeutic targets for preventing and treating insulin resistance or type 2 diabetes.

TP53 gene is often mutated in gastric cancer (GC), nonetheless its relationship with clinicopathological characteristics and prognosis is still unclear. Here, we sought to ascertain the difference in clinical phenotypes between TP53 wild-type and mutant tumors in confirmed gastric cancer patients. To this end, we analyzed TP53 mutation status of 415 TCGA GC patients in relation to their clinical and pathological features as well as prognosis. Longrank Test showed that the survival rate of gastric cancer patients with TP53 WT was significantly lower than that of TP53 mut. Compared with TP53 mut gastric cancer patients with low mRNA expression, TP53 WT patients with low mRNA expression have lower overall survival rate. The death risk of TP53 WT gastric cancer patients is 1.395 times that of TP53 mut gastric cancer patients. The death risk of TP53 mut gastric cancer patients is not related to age, and advanced age is not a risk factor. However, the death risk of TP53 WT patients with gastric cancer increases with age, and the death risk of patients over 70 years old is 1.899 times that of patients under 60 years old. These results suggest that the prognosis of elderly gastric cancer patients with TP53 WT is worse. Conclusion: our results indicate that the status of TP53 mutation in GC is significantly correlated with clinical or molecular categories and that the prognosis of GC patients with WT TP53 is worse than that of patients with mutant TP53. Therefore, our data emphasize the importance of distinguishing TP53 WT to predict poor overall survival and relapse-free survival in patients with GC.

Aims: Epidemiologic evidence indicates that diabetes may increase risk of breast cancer (BC) and mortality in patients with cancer. The pathophysiological relationships between diabetes and cancer are not fully understood, and personalized treatments for diabetes-associated BC are urgently needed. Results: We observed that high glucose (HG), via activation of nuclear phosphatase PP2Cδ, suppresses p53 function, and consequently promotes BC cell proliferation, migration, and invasion. PP2Cδ expression is higher in tumor tissues from BC patients with hyperglycemia than those with normoglycemia. The mechanisms underlying HG stimulation of PP2Cδ involve classical/novel protein kinase-C (PKC) activation and GSK3β phosphorylation. Reactive oxygen species (ROS)/NF-κB pathway also mediates HG induction of PP2Cδ. Furthermore, we identified a 1,5-diheteroarylpenta-1,4-dien-3-one (Compound 23, or C23) as a novel potent PP2Cδ inhibitor with a striking cytotoxicity on MCF-7 cells through cell-based screening assay for growth inhibition and activity of a group of curcumin mimics. Beside directly inhibiting PP2Cδ activity, C23 blocks HG induction of PP2Cδ expression via heat shock protein 27 (HSP27) induction and subsequent ablation of ROS/NF-κB activation. C23 can thus significantly block HG-triggered inhibition of p53 activity, leading to the inhibition of cancer cell proliferation, migration, and invasion. In addition, hyperglycemia promotes BC development in diabetic nude mice, and C23 inhibits the xenografted BC tumor growth. Conclusions and Innovation: Our findings elucidate mechanisms that may have contributed to diabetes-associated BC progression, and provide the first evidence to support the possible alternative therapeutic approach to BC patients with diabetes. Antioxid. Redox Signal. 30, 1983-1998.

Chemokines are a family of small cytokines, which guide a variety of immune/inflammatory cells to the site of tumor in tumorigenesis. A dysregulated expression of chemokines is implicated in different types of cancer including prostate cancer. The progression and metastasis of prostate cancer involve a complex network of chemokines that regulate the recruitment and trafficking of immune cells. The chemokine CCL2 and its main receptor CCR2 have been receiving particular interest on their roles in cancer pathogenesis. The up-regulation of CCL2/CCR2 and varied immune conditions in prostate cancer, are associated with cancer advancement, metastasis, and relapse. Here we reviewed recent findings, which link CCL2/CCR2 to the inflammation and cancer pathogenesis, and discussed the therapeutic potential of CCL2/CCR2 axis in cancer treatment based on results from our group and other investigators, with a major focus on prostate cancer.

A greater understanding of factors causing cancer initiation, progression and evolution is of paramount importance. Among them, the serine/threonine phosphatase PPM1D, also referred to as wild-type p53-induced phosphatase 1 (Wip1) or protein phosphatase 2C delta (PP2Cδ), is emerging as an important oncoprotein due to its negative regulation on a number of crucial cancer suppressor pathways. Initially identified as a p53-regulated gene, PPM1D has been afterwards found amplified and more recently mutated in many human cancers such as breast cancer. The latest progress in this field further reveals that selective inhibition of PPM1D to delay tumor onset or reduce tumor burden represents a promising anti-cancer strategy. Here, we review the advances in the studies of the PPM1D activity and its relevance to various cancers, and recent progress in development of PPM1D inhibitors and discuss their potential application in cancer therapy. Consecutive research on PPM1D and its relationship with cancer is essential, as it ultimately contributes to the etiology and treatment of cancer.

RationaleThe mechanistic role of canonical transient receptor potential 6 (TRPC6) channel in chronic obstructive pulmonary disease (COPD) is poorly understood.ObjectivesThe purpose of this study is to determine the role of TRPC6 channel in COPD and its underlying signaling mechanisms in human airway smooth muscle cells (HASMCs).Methods and Main ResultsThe present study examined the effects of TRPC6 channel on nicotine and cigarette induced HASMCs proliferation, migration and mouse airway remodeling models. mRNA and protein expression of TRPC6 were increased in cultured HASMCs incubated with nicotine using real-time PCR and western blot analysis. Nicotine treatment significantly increased TRPC6 transcriptional activity through NF-κB in HASMCs with Co-IP and electrophoretic mobility shift assays (EMSA). Nicotine treatment also increased ROS level in HASMCs, this increase was attenuated by Nox inhibitor apocynin. miR-135a/b-5p down-regulated mRNA and protein level of TRPC6 in HASMCs, while luciferase reporter assay showed that miR-135a/b-5p targeted at the 3’-UTR of TRPC6 mRNA. microRNA-135a/b-5p (miR-135a/b-5p), with a negative correlation to TRPC6 expression, was low in airway smooth muscle of COPD patients. Cigarette-induced airway remodeling mice model also exhibited a large increase in smooth muscle cell proliferation and smooth muscle layer mass with immunohistochemistry assay, this well-characterized airway remodeling was eliminated by lentivirus of TRPC6 knockdown or miR-135a/b-5p overexpression.ConclusionsNicotine exposure results in increased HASMCs proliferation and migration through NF-κB signaling. Inhalation of cigarette causes airway smooth muscle layer re-modeling due to altered TRPC6 elicited Ca2+ influx, miR-135a/b-5p abolishes this change both in vitro and in vivo.

This study investigated the inhibitory effect of arctigenin, a novel anti-inflammatory lignan, on prostate cancer in obese conditions both in vitro and in vivo. In vitro obese models were established by co-culture of mouse adipocytes 3T3-L1 with androgen-sensitive LNCaP human prostate cancer cells, or by culturing LNCaP cells in adipocytes-conditioned medium. Arctigenin significantly inhibited LNCaP proliferation, along with decreased androgen receptor (AR) and increased Nkx3.1 cellular expression. Male severe combined immunodeficiency mice were subcutaneously implanted with human prostate cancer LAPC-4 xenograft tumors for in vivo study. Mice were fed high-fat (HF) diet and orally given arctigenin at 50 mg/kg body weight daily or vehicle control for 6 weeks. Tumor bearing HF control mice showed a significant increase in serum free fatty acids (FFAs) and decrease in subcutaneous/peritoneal fat depots compared to non-tumor bearing control mice. Arctigenin intervention significantly reduced tumor growth by 45%, associated with decreased circulating FFAs and adipokines/cytokines including IGF-1, VEGF, and MCP-1, along with decreased AR, Ki67, and microvessel density and increased Nkx3.1 expression in tumors. These results indicate the strong ability of arctigenin to co-target obesity and tumor itself in inhibition of prostate tumor growth at a lower concentration compared to most phytochemicals.

Aim PDE5A is a leading factor contributing to cGMP signaling and cardiac hypertrophy. However, microRNA-mediated posttranscriptional regulation of PDE5A has not been reported. The aim of this study is to screen the microRNAs that are able to regulate PDE5A and explore the function of the microRNAs in cardiac hypertrophy and remodeling. Methods and results Although miR-19a/b-3p (microRNA-19a-3p and microRNA-19b-3p) have been reported to be differentially expressed during cardiac hypertrophy, the direct targets and the functions of this microRNA family for regulation of cardiac hypertrophy have not yet been investigated. The present study identified some direct targets and the underlying functions of miR-19a/b-3p by using bioinformatics tools and gene manipulations within mouse neonatal cardiomyocytes. Transfection of miR-19a/b-3p down-regulated endogenous expressions of PDE5A at both mRNA and protein levels with real-time PCR and western blot. Luciferase reporter assays showed that PDE5A was a direct target of miR-19a/b-3p. In mouse models of cardiac hypertrophy, we found that miR-19a/b-3p was expressed in cardiomyocytes and that its expression was reduced in pressure overload-induced hypertrophic hearts. miR-19a/b-3p transgenic mice prevented the progress of cardiac hypertrophy and cardiac remodeling in response to angiotensin II infusion with echocardiographic assessment and pressure-volume relation analysis. Conclusion Our study elucidates that PDE5A is a novel direct target of miR-19a/b-3p, and demonstrates that antihypertrophic roles of the miR-19a/b-3p family in Ang II-induced hypertrophy and cardiac remodeling, suggests that endogenous miR-19a/b-3p might have clinical potential to suppress cardiac hypertrophy and heart failure.

Aberrant PP2Cδ inhibits p300-mediated p53 acetylation and activation via the ATM/BRCA1 pathway, leading to cancer progression., Although nuclear type 2C protein phosphatase (PP2Cδ) has been demonstrated to be pro-oncogenic with an important role in tumorigenesis, the underlying mechanisms that link aberrant PP2Cδ levels with cancer development remain elusive. Here, we found that aberrant PP2Cδ activity decreases p53 acetylation and its transcriptional activity and suppresses doxorubicin-induced cell apoptosis. Mechanistically, we show that BRCA1 facilitates p300-mediated p53 acetylation by complexing with these two proteins and that S1423/1524 phosphorylation is indispensable for this regulatory process. PP2Cδ, via dephosphorylation of ATM, suppresses DNA damage–induced BRCA1 phosphorylation, leading to inhibition of p300-mediated p53 acetylation. Furthermore, PP2Cδ levels correlate with histological grade and are inversely associated with BRCA1 phosphorylation and p53 acetylation in breast cancer specimens. C23, our newly developed PP2Cδ inhibitor, promotes the anticancer effect of doxorubicin in MCF-7 xenograft–bearing nude mice. Together, our data indicate that PP2Cδ impairs p53 acetylation and DNA damage response by compromising BRCA1 function.

Matrix metalloproteinase (MMP)-mediated degradation of the extracellular matrix is a major factor for tumor invasion and metastasis. MMP-12, as metalloelastase, its function in tumor progression remains contradictory. This study was undertaken to investigate the role of MMP-12 in esophageal squamous cell carcinoma (ESCC). We analyzed the protein expression of MMP-12 and its association with clinicopatholigical parameters, as well as survival analysis. MMP-12 was highly expressed in tumor cells comparing with normal epithelial cells. The high expression of MMP-12 was significantly correlated with tumor grade and stage, nodal metastasis and poor survival of ESCC. Cox multivariate analysis revealed that MMP-12 was an independent prognostic factor in ESCC. Our results suggest that MMP-12 might act as a potential target for the development of novel therapeutics of esophageal squamous cell carcinoma.

Breast cancer has a high incidence worldwide. The results of substantial studis reveal that inflammation plays an important role in the initiation, development, and aggressiveness of many malignancies. The use of celecoxib, a novel NSAID, is repetitively associated with the reduced risk of the occurrence and progression of a number of types of cancer, particularly breast cancer. This observation is also substantiated by various meta-analyses. Clinical trials have been implemented on integration treatment of celecoxib and shown encouraging results. Celecoxib could be treated as a potential candidate for antitumor agent. There are, nonetheless, some unaddressed questions concerning the precise mechanism underlying the anticancer effect of celecoxib as well as its activity against different types of cancer. In this review, we discuss different mechanisms of anticancer effect of celecoxib as well as preclinical/clinical results signifying this beneficial effect.

Transient receptor potential-3 (TRPC3) channels play a predominant role in forming nonselective cation channels (NSCCs) in airway smooth muscle cells (ASMCs) and are significantly increased in their activity and expression in asthmatic ASMCs. To extend these novel findings, we have explored the regulatory mechanisms that control the activity of TRPC3 channels. Our data for the first time reveal that inositol 1,4,5-trisphosphate (IP3), an important endogenous signaling molecule, can significantly enhance the activity of single NSCCs in ASMCs. The analog of diacylglycerol (DAG; another endogenous signaling molecule), 1-oleyl-2-acetyl- sn-glycerol (OAG), 1-stearoyl-2-arachidonoyl- sn-glycerol (SAG), and 1-stearoyl-2-linoleoyl- sn-glycerol (SLG) all augment NSCC activity. The effects of IP3 and OAG are fully abolished by lentiviral short-hairpin (sh)RNA-mediated TRPC3 channel knockdown (KD). The stimulatory effect of IP3 is eliminated by heparin, an IP3 receptor (IP3R) antagonist that blocks the IP3-binding site, but not by xestospongin C, the IP3R antagonist that has no effect on the IP3-binding site. Lentiviral shRNA-mediated KD of IP3R1, IP3R2, or IP3R3 does not alter the excitatory effect of IP3. TRPC3 channel KD greatly inhibits IP3-induced increase in intracellular Ca2+ concentration. IP3R1 KD produces a similar inhibitory effect. TRPC3 channel and IP3R1 KD both diminish the muscarinic receptor agonist methacholine-evoked Ca2+ responses. Taking these findings together, we conclude that IP3, the important intracellular second messenger, may activate TRPC3 channels to cause extracellular Ca2+ influx, in addition to opening IP3Rs to induce intracellular Ca2+ release. This novel extracellular Ca2+ entry route may play a significant role in mediating IP3-mediated numerous cellular responses in ASMCs and other cells.

Background The value of layer-specific two-dimensional speckle tracking echocardiography (LS2D-STE) for evaluating viable myocardium (VM) in patients with acute myocardial infarction (AMI) was unclear, this study provides new insights into it and to make a comparison with dualisotope simultaneous acquisition single photon emission computed tomography ( DISA-SPECT). Methods Forty hospitalized patients with AMI and left ventricular systolic dysfunction (left ventricular ejection fraction Results The sensitivity, specificity and accuracy of DISA-SPECT for evaluating VM were 82.1%, 74.3%, and 79.3%, respectively. Among the layer-specific parameters, only endocardial (endo-) longitudinal strain (LS) and endo- longitudinal strain rate (LSr) were used as independent parameters for evaluating VM (P .05). Conclusion The endo-LS and endo-LSr analysis of LS2D-STE can evaluate the VM well, and its sensitivity, specificity and accuracy in detection of VM are similar to those of DISA-SPECT, resulting in LS2D-STE being a good option for the assessment of VM.