Extensive pre-mRNA back-splicing generates numerous circular RNAs (circRNAs) in human transcriptome. However, the biological functions of these circRNAs remain largely unclear. Here we report that N6-methyladenosine (m6A), the most abundant base modification of RNA, promotes efficient initiation of protein translation from circRNAs in human cells. We discover that consensus m6A motifs are enriched in circRNAs and a single m6A site is sufficient to drive translation initiation. This m6A-driven translation requires initiation factor eIF4G2 and m6A reader YTHDF3, and is enhanced by methyltransferase METTL3/14, inhibited by demethylase FTO, and upregulated upon heat shock. Further analyses through polysome profiling, computational prediction and mass spectrometry reveal that m6A-driven translation of circRNAs is widespread, with hundreds of endogenous circRNAs having translation potential. Our study expands the coding landscape of human transcriptome, and suggests a role of circRNA-derived proteins in cellular responses to environmental stress.

While the human transcriptome contains a large number of circular RNAs (circRNAs), the functions of most circRNAs remain unclear. Sequence annotation suggests that most circRNAs are generated from splicing in reversed orders across exons. However, the mechanisms of this backsplicing are largely unknown. Here we constructed a single exon minigene containing split GFP, and found that the pre-mRNA indeed produces circRNA through efficient backsplicing in human and Drosophila cells. The backsplicing is enhanced by complementary introns that form double-stranded RNA structure to bring splice sites in proximity, but such structure is not required. Moreover, backsplicing is regulated by general splicing factors and cis-elements, but with regulatory rules distinct from canonical splicing. The resulting circRNA can be translated to generate functional proteins. Unlike linear mRNA, poly-adenosine or poly-thymidine in 3' UTR can inhibit circular mRNA translation. This study revealed that backsplicing can occur efficiently in diverse eukaryotes to generate circular mRNAs.

BACKGROUND

Chemotherapy is an important component in the treatment paradigm for breast cancers. However, the resistance of cancer cells to chemotherapeutic agents frequently results in the subsequent recurrence and metastasis. Identification of molecular markers to predict treatment outcome is therefore warranted. The aim of the present study was to evaluate whether expression of circulating microRNAs (miRNAs) can predict clinical outcome in breast cancer patients treated with adjuvant chemotherapy.

RESULTS

Circulating miRNAs in blood serum prior to treatment were determined by quantitative Real-Time PCR in 56 breast cancer patients with invasive ductal carcinoma and pre-operative neoadjuvant chemotherapy. Proliferating cell nuclear antigen (PCNA) immunostaining and TUNEL were performed in surgical samples to determine the effects of chemotherapy on cancer cell proliferation and apoptosis, respectively. Among the miRNAs tested, only miR-125b was significantly associated with therapeutic response, exhibiting higher expression level in non-responsive patients (n = 26, 46%; p = 0.008). In addition, breast cancers with high miR-125b expression had higher percentage of proliferating cells and lower percentage of apoptotic cells in the corresponding surgical specimens obtained after neoadjuvant chemotherapy. Increased resistance to anticancer drug was observed in vitro in breast cancer cells with ectopic miR-125b expression; conversely, reducing miR-125b level sensitized breast cancer cells to chemotherapy. Moreover, we demonstrated that the E2F3 was a direct target of miR-125b in breast cancer cells.

CONCLUSIONS

These data suggest that circulating miR-125b expression is associated with chemotherapeutic resistance of breast cancer. This finding has important implications in the development of targeted therapeutics for overcoming chemotherapeutic resistance in novel anti-cancer strategies.

Natural killer/T-cell lymphoma (NKTCL) is a malignant proliferation of CD56(+) and cytoCD3(+) lymphocytes with aggressive clinical course, which is prevalent in Asian and South American populations. The molecular pathogenesis of NKTCL has largely remained elusive. We identified somatic gene mutations in 25 people with NKTCL by whole-exome sequencing and confirmed them in an extended validation group of 80 people by targeted sequencing. Recurrent mutations were most frequently located in the RNA helicase gene DDX3X (21/105 subjects, 20.0%), tumor suppressors (TP53 and MGA), JAK-STAT-pathway molecules (STAT3 and STAT5B) and epigenetic modifiers (MLL2, ARID1A, EP300 and ASXL3). As compared to wild-type protein, DDX3X mutants exhibited decreased RNA-unwinding activity, loss of suppressive effects on cell-cycle progression in NK cells and transcriptional activation of NF-κB and MAPK pathways. Clinically, patients with DDX3X mutations presented a poor prognosis. Our work thus contributes to the understanding of the disease mechanism of NKTCL.

The Wnt1 protein, a secreted ligand that activates Wnt signaling pathways, contributes to the self-renewal of cancer stem cells (CSCs) and thus may be a major determinant of tumor progression and chemoresistance. In a series of gastric cancer specimens, we found strong correlations among Wnt1 expression, CD44 expression, and the grade of gastric cancer. Stable overexpression of Wnt1 increased AGS gastric cancer cells' proliferation rate and spheroids formation, which expressed CSC surface markers Oct4 and CD44. Subcutaneous injection of nude mice with Wnt1-overexpressing AGS cells resulted in larger tumors than injection of control AGS cells. Salinomycin, an antitumor agent, significantly reduced the volume of tumor caused by Wnt1-overexpressing AGS cells in vivo. This is achieved by inhibiting the proliferation of CD44+Oct4+ CSC subpopulation, at least partly through the suppression of Wnt1 and β-catenin expression. Taken together, activation of Wnt1 signaling accelerates the proliferation of gastric CSCs, whereas salinomycin acts to inhibit gastric tumor growth by suppressing Wnt signaling in CSCs. These results suggest that Wnt signaling might have a critical role in the self-renewal of gastric CSCs, and salinomycin targeting Wnt signaling may have important clinical applications in gastric cancer therapy.

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder caused by selective motor neuron degeneration. Abnormal protein aggregation and impaired protein degradation pathways may contribute to the disease pathogenesis. Although it has been reported that autophagy is altered in patients and animal model of ALS, little is known about the role of autophagy in motor neuron degeneration in this disease. Our previous study shows that rapamycin, an MTOR-dependent autophagic activator, accelerates disease progression in the SOD1(G93A) mouse model of ALS. In the present report, we have assessed the role of the MTOR-independent autophagic pathway in ALS by determining the effect of the MTOR-independent autophagic inducer trehalose on disease onset and progression, and on motor neuron degeneration in SOD1(G93A) mice. We have found that trehalose significantly delays disease onset prolongs life span, and reduces motor neuron loss in the spinal cord of SOD1(G93A) mice. Most importantly, we have documented that trehalose decreases SOD1 and SQSTM1/p62 aggregation, reduces ubiquitinated protein accumulation, and improves autophagic flux in the motor neurons of SOD1(G93A) mice. Moreover, we have demonstrated that trehalose can reduce skeletal muscle denervation, protect mitochondria, and inhibit the proapoptotic pathway in SOD1(G93A) mice. Collectively, our study indicated that the MTOR-independent autophagic inducer trehalose is neuroprotective in the ALS model and autophagosome-lysosome fusion is a possible therapeutic target for the treatment of ALS.

Macrophages acquire distinct phenotypes during tissue stress and inflammatory responses, but the mechanisms that regulate the macrophage polarization are poorly defined. Here we show that tuberous sclerosis complex 1 (TSC1) is a critical regulator of M1 and M2 phenotypes of macrophages. Mice with myeloid-specific deletion of TSC1 exhibit enhanced M1 response and spontaneously develop M1-related inflammatory disorders. However, TSC1-deficient mice are highly resistant to M2-polarized allergic asthma. Inhibition of the mammalian target of rapamycin (mTOR) fails to reverse the hypersensitive M1 response of TSC1-deficient macrophages, but efficiently rescues the defective M2 polarization. Deletion of mTOR also fails to reverse the enhanced inflammatory response of TSC1-deficient macrophages. Molecular studies indicate that TSC1 inhibits M1 polarization by suppressing the Ras GTPase-Raf1-MEK-ERK pathway in mTOR-independent manner, whereas TSC1 promotes M2 properties by mTOR-dependent CCAAT/enhancer-binding protein-β pathways. Overall, these findings define a key role for TSC1 in orchestrating macrophage polarization via mTOR-dependent and independent pathways.

The Yorkie homologues YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif, also known as WWTR1), effectors of the Hippo pathway, have been identified as mediators for mechanical stimuli. However, the role of YAP/TAZ in haemodynamics-induced mechanotransduction and pathogenesis of atherosclerosis remains unclear. Here we show that endothelial YAP/TAZ activity is regulated by different patterns of blood flow, and YAP/TAZ inhibition suppresses inflammation and retards atherogenesis. Atheroprone-disturbed flow increases whereas atheroprotective unidirectional shear stress inhibits YAP/TAZ activity. Unidirectional shear stress activates integrin and promotes integrin-Gα13 interaction, leading to RhoA inhibition and YAP phosphorylation and suppression. YAP/TAZ inhibition suppresses JNK signalling and downregulates pro-inflammatory genes expression, thereby reducing monocyte attachment and infiltration. In vivo endothelial-specific YAP overexpression exacerbates, while CRISPR/Cas9-mediated Yap knockdown in endothelium retards, plaque formation in ApoE-/- mice. We also show several existing anti-atherosclerotic agents such as statins inhibit YAP/TAZ transactivation. On the other hand, simvastatin fails to suppress constitutively active YAP/TAZ-induced pro-inflammatory gene expression in endothelial cells, indicating that YAP/TAZ inhibition could contribute to the anti-inflammatory effect of simvastatin. Furthermore, activation of integrin by oral administration of MnCl2 reduces plaque formation. Taken together, our results indicate that integrin-Gα13-RhoA-YAP pathway holds promise as a novel drug target against atherosclerosis.

Cancer-associated fibroblasts (CAFs) provide critical metabolites for tumor growth and undergo metabolic reprogramming to support glycolysis. However, the molecular mechanisms responsible for this change remain unclear. Here, we report that TGF-β1- or PDGF-induced CAFs switch from oxidative phosphorylation to aerobic glycolysis. We identify downregulation of isocitrate dehydrogenase 3α (IDH3α) as a marker for this switch. Furthermore, miR-424 downregulates IDH3α during CAF formation. Downregulation of IDH3α decreases the effective level of α-ketoglutarate (α-KG) by reducing the ratio of α-KG to fumarate and succinate, resulting in PHD2 inhibition and HIF-1α protein stabilization. The accumulation of HIF-1α, in turn, promotes glycolysis by increasing the uptake of glucose, upregulating expression of glycolytic enzymes under normoxic conditions, and inhibiting oxidative phosphorylation by upregulating NDUFA4L2. CAFs from tumor samples exhibit low levels of IDH3α, and overexpression of IDH3α prevents transformation of fibroblasts into CAFs. Our studies reveal IDH3α to be a critical metabolic switch in CAFs.

Protein phosphorylation is one of the most common post-translational modifications. It plays key roles in regulating diverse biological processes of liver tissues. To better understand the role of protein phosphorylation in liver functions, it is essential to perform in-depth phosphoproteome analysis of human liver. Here, an enzyme assisted reversed-phase-reversed-phase liquid chromatography (RP-RPLC) approach with both RPLC separations operated with optimized acidic mobile phase was developed. High orthogonal separation was achieved by trypsin digestion of the Glu-C generated peptides in the fractions collected from the first RPLC separation. The phosphoproteome coverage was further improved by using two types of instruments, i.e. TripleTOF 5600 and LTQ Orbitrap Velos. A total of 22,446 phosphorylation sites, corresponding to 6526 nonredundant phosphoproteins were finally identified from normal human liver tissues. Of these sites, 15,229 sites were confidently localized with Ascore≥13. This dataset was the largest phosphoproteome dataset of human liver. It can be a public resource for the liver research community and holds promise for further biology studies.

UNASSIGNED

The enzyme assisted approach enabled the two RPLC separations operated both with optimized acidic mobile phases. The identifications from TripleTOF 5600 and Orbitrap Velos are highly complementary. The largest phosphoproteome dataset of human liver was generated.

Oct-4 and Nanog in regulating the epithelial-mesenchymal transition (EMT) and metastasis of breast cancer has not been clarified. We found that both Oct-4 and Nanog expression were significantly associated with tumor pathology and poor prognosis in 126 breast cancer patients. Characterization of CD44+CD24-Cancer stem cell(CSC) derived from breast cancer cells indicated that CSC rapidly formed mammospheres and had potent tumorigenicity in vivo. Furthermore, TGF-β up-regulated the expression of Oct-4, Nanog, N-cadherin, vimentin, Slug, and Snail, but down-regulated E-cadherin and cytokeratin 18 expression, demonstrating that CSC underwent EMT. Knockdown of both Oct-4 and Nanog expression inhibited spontaneous changes in the expression of EMT-related genes, while induction of both Oct-4 and Nanog over-expression enhanced spontaneous changes in the expression of EMT-related genes in CSC. However, perturbing alternation of Oct-4 and Nanog expression also modulated TGF-β-induced EMT-related gene expression in CSC. Induction of Oct-4 and Nanog over-expression enhanced the invasiveness of CSC, but knockdown of both Oct-4 and Nanog inhibited the migration of CSC in vitro. Our data suggest that both Oct-4 and Nanog may serve as biomarkers for evaluating breast cancer prognosis. Our findings indicate that Oct-4 and Nanog positively regulate the EMT process, contributing to breast cancer metastasis.

Lung cancer is the leading cause of cancer-related death worldwide. In China, the incidence of lung cancer has grown rapidly, resulting in a large social and economic burden. Several researchers have devoted their studies to lung cancer and have demonstrated that there are many risk factors for lung cancer in China, including tobacco use, environmental pollution, food, genetics, and chronic obstructive pulmonary disease. However, the lung cancer incidence is still growing rapidly in China, and there is an even higher incidence among the younger generation. One explanation may be the triple-neglect situation, in which medical policies that neglect prevention, diagnosis, and supportive care have increased patients' mortality and reduced their quality of life. Therefore, it is necessary to enhance the efficiency of prevention and early diagnosis not only by focusing more attention on treatment but also by drawing more attention to supportive care for patients with lung cancer.

Child-Pugh and MELD scores have been widely used for the assessment of prognosis in liver cirrhosis. A systematic review and meta-analysis aimed to compare the discriminative ability of Child-Pugh versus MELD score to assess the prognosis of cirrhotic patients.PubMed and EMBASE databases were searched. The statistical results were summarized from every individual study. The summary areas under receiver operating characteristic curves, sensitivities, specificities, positive and negative likelihood ratios, and diagnostic odds ratios were also calculated.Of the 1095 papers initially identified, 119 were eligible for the systematic review. Study population was heterogeneous among studies. They included 269 comparisons, of which 44 favored MELD score, 16 favored Child-Pugh score, 99 did not find any significant difference between them, and 110 did not report the statistical significance. Forty-two papers were further included in the meta-analysis. In patients with acute-on-chronic liver failure, Child-Pugh score had a higher sensitivity and a lower specificity than MELD score. In patients admitted to ICU, MELD score had a smaller negative likelihood ratio and a higher sensitivity than Child-Pugh score. In patients undergoing surgery, Child-Pugh score had a higher specificity than MELD score. In other subgroup analyses, Child-Pugh and MELD scores had statistically similar discriminative abilities or could not be compared due to the presence of significant diagnostic threshold effects.Although Child-Pugh and MELD scores had similar prognostic values in most of cases, their benefits might be heterogeneous in some specific conditions. The indications for Child-Pugh and MELD scores should be further identified.

Capsaicin bestows spiciness by activating TRPV1 channel with exquisite potency and selectivity. Although a capsaicin-bound channel structure was previously resolved by cryo-EM at 4.2- to 4.5-Å resolution, capsaicin was registered as a small electron density, reflecting neither its chemical structure nor specific ligand-channel interactions--important details required for mechanistic understanding. We obtained the missing atomic-level details by iterative computation and confirmed them by systematic site-specific functional tests. We observed that the bound capsaicin takes a 'tail-up, head-down' configuration. The vanillyl and amide groups form specific interactions to anchor its bound position, while the aliphatic tail may sample a range of conformations, making it invisible in cryo-EM images. Capsaicin stabilizes TRPV1's open state by 'pull-and-contact' interactions between the vanillyl group and the S4-S5 linker. Our study provides a structural mechanism for the agonistic function of capsaicin and its analogs, and demonstrates an effective approach to obtain atomic-level information from cryo-EM structures.

Acute myeloid leukemia (AML) is a group of hematological malignancies with high heterogeneity. There is an increasing need to improve the risk stratification of AML patients, including those with normal cytogenetics, using molecular biomarkers. Here, we report a metabolomics study that identified a distinct glucose metabolism signature with 400 AML patients and 446 healthy controls. The glucose metabolism signature comprises a panel of 6 serum metabolite markers, which demonstrated prognostic value in cytogenetically normal AML patients. We generated a prognosis risk score (PRS) with 6 metabolite markers for each patient using principal component analysis. A low PRS was able to predict patients with poor survival independently of well-established markers. We further compared the gene expression patterns of AML blast cells between low and high PRS groups, which correlated well to the metabolic pathways involving the 6 metabolite markers, with enhanced glycolysis and tricarboxylic [corrected] acid cycle at gene expression level in low PRS group. In vitro results demonstrated enhanced glycolysis contributed to decreased sensitivity to antileukemic agent arabinofuranosyl cytidine (Ara-C), whereas inhibition of glycolysis suppressed AML cell proliferation and potentiated cytotoxicity of Ara-C. Our study provides strong evidence for the use of serum metabolites and metabolic pathways as novel prognostic markers and potential therapeutic targets for AML.

Ferroptosis is a recently identified form of regulated cell death defined by the iron-dependent accumulation of lipid reactive oxygen species. Ferroptosis has been studied in various diseases such as cancer, Parkinson's disease, and stroke. However, the exact function and mechanism of ferroptosis in ischemia/reperfusion (I/R) injury, especially in the intestine, remains unknown. Considering the unique conditions required for ferroptosis, we hypothesize that ischemia promotes ferroptosis immediately after intestinal reperfusion. In contrast to conventional strategies employed in I/R studies, we focused on the ischemic phase. Here we verified ferroptosis by assessing proferroptotic changes after ischemia along with protein and lipid peroxidation levels during reperfusion. The inhibition of ferroptosis by liproxstatin-1 ameliorated I/R-induced intestinal injury. Acyl-CoA synthetase long-chain family member 4 (ACSL4), which is a key enzyme that regulates lipid composition, has been shown to contribute to the execution of ferroptosis, but its role in I/R needs clarification. In the present study, we used rosiglitazone (ROSI) and siRNA to inhibit ischemia/hypoxia-induced ACSL4 in vivo and in vitro. The results demonstrated that ACSL4 inhibition before reperfusion protected against ferroptosis and cell death. Further investigation revealed that special protein 1 (Sp1) was a crucial transcription factor that increased ACSL4 transcription by binding to the ACSL4 promoter region. Collectively, this study demonstrates that ferroptosis is closely associated with intestinal I/R injury, and that ACSL4 has a critical role in this lethal process. Sp1 is an important factor in promoting ACSL4 expression. These results suggest a unique and effective mechanistic approach for intestinal I/R injury prevention and treatment.

Splicing dysregulation is one of the molecular hallmarks of cancer. However, the underlying molecular mechanisms remain poorly defined. Here we report that the splicing factor RBM4 suppresses proliferation and migration of various cancer cells by specifically controlling cancer-related splicing. Particularly, RBM4 regulates Bcl-x splicing to induce apoptosis, and coexpression of Bcl-xL partially reverses the RBM4-mediated tumor suppression. Moreover, RBM4 antagonizes an oncogenic splicing factor, SRSF1, to inhibit mTOR activation. Strikingly, RBM4 expression is decreased dramatically in cancer patients, and the RBM4 level correlates positively with improved survival. In addition to providing mechanistic insights of cancer-related splicing dysregulation, this study establishes RBM4 as a tumor suppressor with therapeutic potential and clinical values as a prognostic factor.

OBJECTIVE

Comprehensive epidemiologic data on AKI are particularly lacking in Asian countries. This study sought to assess the epidemiology and clinical correlates of AKI among hospitalized adults in China.

METHODS

This was a multicenter retrospective cohort study of 659,945 hospitalized adults from a wide range of clinical settings in nine regional central hospitals across China in 2013. AKI was defined and staged according to Kidney Disease Improving Global Outcomes criteria. The incidence of AKI in the cohort was estimated using a novel two-step approach with adjustment for the frequency of serum creatinine tests and other potential confounders. Risk factor profiles for hospital-acquired (HA) and community-acquired (CA) AKI were examined. The in-hospital outcomes of AKI, including mortality, renal recovery, length of stay, and daily cost, were assessed.

RESULTS

The incidence of CA-AKI and HA-AKI was 2.5% and 9.1%, respectively, giving rise to an overall incidence of 11.6%. Although the risk profiles for CA-AKI and HA-AKI differed, preexisting CKD was a major risk factor for both, contributing to 20% of risk in CA-AKI and 12% of risk in HA-AKI. About 40% of AKI cases were possibly drug-related and 16% may have been induced by Chinese traditional medicines or remedies. The in-hospital mortality of AKI was 8.8%. The risk of in-hospital death was higher among patients with more severe AKI. Preexisting CKD and need for intensive care unit admission were associated with higher death risk in patients at any stage of AKI. Transiency of AKI did not modify the risk of in-hospital death. AKI was associated with longer length of stay and higher daily costs, even after adjustment for confounders.

CONCLUSIONS

AKI is common in hospitalized adults in China and is associated with significantly higher in-hospital mortality and resource utilization.

Neddylation, the covalent attachment of ubiquitin-like protein Nedd8, of the Cullin-RING E3 ligase family regulates their ubiquitylation activity. However, regulation of HECT ligases by neddylation has not been reported to date. Here we show that the C2-WW-HECT ligase Smurf1 is activated by neddylation. Smurf1 physically interacts with Nedd8 and Ubc12, forms a Nedd8-thioester intermediate, and then catalyses its own neddylation on multiple lysine residues. Intriguingly, this autoneddylation needs an active site at C426 in the HECT N-lobe. Neddylation of Smurf1 potently enhances ubiquitin E2 recruitment and augments the ubiquitin ligase activity of Smurf1. The regulatory role of neddylation is conserved in human Smurf1 and yeast Rsp5. Furthermore, in human colorectal cancers, the elevated expression of Smurf1, Nedd8, NAE1 and Ubc12 correlates with cancer progression and poor prognosis. These findings provide evidence that neddylation is important in HECT ubiquitin ligase activation and shed new light on the tumour-promoting role of Smurf1.

BACKGROUND

Recently, we reported that overexpression of metastasis-associated colon cancer-1 (MACC1) mRNA may be a useful marker for predicting postoperative recurrence in patients with lung adenocarcinoma following surgery. However, the biological significance of mRNA overexpression is difficult to determine and is not widely used because mRNA expression analysis is relatively expensive and time- and labor-intensive. On the other hand, immunohistochemical (IHC) staining is easy to perform, well-established, inexpensive, and is a useful method which can be routinely applied in solid tumor diagnosis in clinical laboratories.

METHODS

Tumor specimens were collected from 197 consecutive patients who underwent a complete resection for lung adenocarcinoma from 1998 to 2007. We analyzed the MACC1 status of the primary lung adenocarcinoma by IHC analysis.

RESULTS

The average postoperative observation period was 46.7 months. Forty (20.3%) of the 197 patients developed recurrences after surgery. Positive expression of MACC1 was identified in 129 (65.5%) patients. Furthermore, MACC1 IHC was positive in 33 (82.5%) out of the 40 patients and 96 (61.1%) out of the 157 patients, with and without recurrence, respectively (p=0.011). Both univariate and multivariate logistic regression models indicated that positive staining for MACC1 was an independent factor for tumor recurrence. Furthermore, positive staining for MACC1 was associated with poorer disease-free survival (DFS), according to the univariate survival analysis (p=0.080).

CONCLUSIONS

Positive staining for MACC1 expression in resected specimens was associated with a poorer DFS. Therefore, positive staining of IHC for MACC1 may be a useful marker for predicting postoperative recurrence in patients with lung adenocarcinoma following surgery.

Hyperleptinemia is a common feature of obese women who have a higher risk of endometrial cancer than women with normal weights, and epidemiologic studies have suggested a correlation between obesity and endometrial carcinoma. Therefore, understanding of the molecular mechanism involved in leptin signaling transduction is important in endometrial cancer prevention and treatment. In this study, both isoforms of the leptin receptor (Ob-R), the long form (Ob-Rb) and short form (Ob-Ra), were detected as being expressed in six endometrial cancer cell lines with various differentiation status by western blotting, and Ob-Ra was found to be more abundant than Ob-Rb in these cells. Moreover, the expressions of both isoforms were inversely correlated with histoprognostic grading. We also showed that leptin stimulated cell proliferation and induced activations of signal transducers and activators of transcription 3 (STAT3), extracellular signal-regulated kinase (ERK1/2), AKT, and cyclooxygenase (COX)-2 in endometrial cancer cells dose-dependently by [(3)H] thymidine incorporation assay and western blotting. Leptin-stimulation resulted in increased expression of COX-2 mRNA and prostaglandin E2 (PGE2) production of endometrial cancer cells by reverse transcription-polymerase chain reaction and enzyme immunoassay, respectively, which was effectively blocked by pharmacological inhibitors of Janus tyrosine kinase 2 (JAK2), AG490; of mitogen-activated protein kinase (MAPK) kinase, U0126; of phosphatidylinositol 3-kinase (PI3K), LY294002; and of COX-2, NS398. These results suggest that leptin promotes cell proliferation of endometrial cancer cells via the aforementioned multiple signal-transduction pathways. Leptin-induced functional activation of COX-2 is JAK2/STAT3-, MAPK/ERK-, and PI3K/AKT-dependent, indicating that COX-2 may be a critical factor of endometrial carcinogenesis in obesity.

Fructose-bisphosphate aldolase A (ALDOA) is a key enzyme in glycolysis and is responsible for catalyzing the reversible conversion of fructose-1,6-bisphosphate to glyceraldehydes-3-phosphate and dihydroxyacetone phosphate. ALDOA contributes to various cellular functions such as muscle maintenance, regulation of cell shape and mobility, striated muscle contraction, actin filament organization and ATP biosynthetic process. Here, we reported that ALDOA is a highly expressed in lung squamous cell carcinoma (LSCC) and its expression level is correlated with LSCC metastasis, grades, differentiation status and poor prognosis. Depletion of ALDOA expression in the lung squamous carcinoma NCI-H520 cells reduces the capabilities of cell motility and tumorigenesis. These data suggest that ALDOA could be a potential marker for LSCC metastasis and a therapeutic target for drug development.

beta-Elemene, a natural plant drug extracted from Curcuma wenyujin, has been used as an antitumor drug for different tumors, including glioblastoma. However, the mechanism of its anti-tumor effect is largely unknown. Here we report that anti-proliferation of glioblastoma cells induced by beta-elemene was dependent on p38 MAPK activation. Treatment of glioblastoma cell lines with beta-elemene, led to phosphorylation of p38 MAPK, cell-cycle arrest in G0/G1 phase and inhibition of proliferation of these cells. Inhibition of p38 MAPK reversed beta-elemene-mediated anti-proliferation effect. Furthermore, the growth of glioblastoma cell-transplanted tumors in nude mice was inhibited by intraperitoneal injection of beta-elemene. Taken together, our findings indicate that activation of p38 MAPK is critical for the anti-proliferation effect of beta-elemene and that p38 MAPK might be a putative pharmacological target for glioblastoma therapy.