The full scale of human miRNome in specific cell or tissue, especially in cancers, remains to be determined. An in-depth analysis of miRNomes in human normal liver, hepatitis liver, and hepatocellular carcinoma (HCC) was carried out in this study. We found nine miRNAs accounted for ∼88.2% of the miRNome in human liver. The third most highly expressed miR-199a/b-3p is consistently decreased in HCC, and its decrement significantly correlates with poor survival of HCC patients. Moreover, miR-199a/b-3p can target tumor-promoting PAK4 to suppress HCC growth through inhibiting PAK4/Raf/MEK/ERK pathway both in vitro and in vivo. Our study provides miRNomes of human liver and HCC and contributes to better understanding of the important deregulated miRNAs in HCC and liver diseases.

Intracellular nucleic acid sensors detect microbial RNA and DNA and trigger the production of type I interferon. However, the cytosolic nucleic acid-sensing system remains to be fully identified. Here we show that the cytosolic nucleic acid-binding protein LRRFIP1 contributed to the production of interferon-beta (IFN-beta) induced by vesicular stomatitis virus (VSV) and Listeria monocytogenes in macrophages. LRRFIP1 bound exogenous nucleic acids and increased the expression of IFN-beta induced by both double-stranded RNA and double-stranded DNA. LRRFIP1 interacted with beta-catenin and promoted the activation of beta-catenin, which increased IFN-beta expression by binding to the C-terminal domain of the transcription factor IRF3 and recruiting the acetyltransferase p300 to the IFN-beta enhanceosome via IRF3. Therefore, LRRFIP1 and its downstream partner beta-catenin constitute another coactivator pathway for IRF3-mediated production of type I interferon.

In hepatocellular carcinoma (HCC), biomarkers for prediction of prognosis and response to immunotherapy such as interferon-α (IFN-α) would be very useful in the clinic. We found that expression of retinoic acid-inducible gene-I (RIG-I), an IFN-stimulated gene, was significantly downregulated in human HCC tissues. Patients with low RIG-I expression had shorter survival and poorer response to IFN-α therapy, suggesting that RIG-I is a useful prognosis and IFN-α response predictor for HCC patients. Mechanistically, RIG-I enhances IFN-α response by amplifying IFN-α effector signaling via strengthening STAT1 activation. Furthermore, we found that RIG-I deficiency promotes HCC carcinogenesis and that hepatic RIG-I expression is lower in men than in women. RIG-I may therefore be a tumor suppressor in HCC and contribute to HCC gender disparity.

Calcium and its major downstream effector, calcium/calmodulin-dependent protein kinase II (CaMKII), are found to be important for the functions of immune cells. Lipopolysaccharide (LPS) has been shown to induce intracellular calcium release in macrophages; however, whether and how CaMKII is required for Toll-like receptor (TLR) signaling remain unknown. Here we demonstrate that TLR 4, 9, and 3 ligands markedly induce intracellular calcium fluxes and activate CaMKII-␣ in macrophages. Selective inhibition or RNA interference of CaMKII significantly suppresses TLR4, 9, 3-triggered production of interleukin-6 (IL-6), tumor necrosis factor-␣, and interferon-␣/␤ (IFN-␣/␤) in macrophages. Coincidently, overexpression of constitutively active CaMKII-␣ significantly enhances production of the above cytokines. In addition to the activation of mitogen-activated protein kinase and nuclear factor B pathways, CaMKII-␣ can directly bind and phosphorylate transforming growth factor ␤-activated kinase 1 (TAK1) and IFN regulatory factor 3 (IRF3; serine IntroductionOn recognition of pathogenic components, Toll-like receptors (TLRs) are activated, leading to a variety of signaling events that initiate innate immunity and activate immune cells to produce proinflammatory cytokines and type I interferon (IFN). 1,2 Most of the members of the TLR family, with the exception of TLR3, trigger immune response via the conserved myeloid differentiation factor 88 (MyD88)-dependent pathway, which involves MyD88, interleukin-1 (IL-1) receptor-associated kinase 1 (IRAK1), tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6), transforming growth factor-␤ (TGF-␤)-activated kinase 1 (TAK1), downstream mitogen-activated protein kinases (MAPKs), and nuclear factor B (NF-B). 2,3 Toll/IL-1 receptor-domain-containing adaptor protein inducing IFN-␤ (TRIF) has been found to induce the expression of type I IFN in response to TLR4 and TLR3 ligands, which associates with TANK-binding kinase 1 (TBK1) and activates downstream IFN regulatory factor 3 (IRF3). In addition, the TRIF pathway also contributes to TLR3-and TLR4-activated proinflammatory cytokine production. 3,4 TLR activation is essential for provoking the innate immune response and enhancing adaptive immunity against invading pathogens. Less efficient activation of the TLR response may not evoke potent anti-infection or antitumor immunity; however, excessive activation of TLR may also induce immunopathologic processes, such as endotoxin shock and autoimmune diseases. How to manipulate or control the TLR response for prevention and treatment of inflammatory and immunologic diseases largely depends on the understanding of the molecular basis for TLR responses. Up to now, molecular mechanisms for the initiation and regulation of TLR responses remain to be fully understood. In addition to the MyD88-or TRIF-dependent pathway, ligation of TLRs has been found to activate various other intracellular signaling molecules, such as phosphatidylinositol 3-kinase (PI3K)/ AKT 5 and MAPK kinase kinase (ME...

Tumors can induce generation and accumulation of the immunosuppressive cells such as regulatory T cells in the tumor

Calcium/calmodulin-dependent protein kinase II (CaMKII) regulates numerous physiological functions. Inhibition of CaMKII activity, mostly by synthetic reagents, has been proved to suppress cell growth in many cases. So far there are no reports about the physiological functions and underlying mechanisms of endogenous CaMKII inhibitory proteins in cell cycle progression. Here we report the characterization of a novel human endogenous CaMKII inhibitor, human CaMKII inhibitory protein ␣ (hCaMKIIN␣), which directly interacts with activated CaMKII and effectively inhibits CaMKII activity. hCaMKIIN␣ expression is negatively correlated with the severity of human colon adenocarcinoma. Overexpression of hCaMKIIN␣ inhibits colon adenocarcinoma growth in vitro and in vivo by arresting the cell cycle at the S phase through its conserved inhibitory region (27CIR), whereas silencing the hCaMKIIN␣ expression accelerates tumor growth and cell cycle progression. We found that the effect of hCaMKIIN␣ on cell cycle is correlated with up-regulation of p27 expression, which may be due to the inhibition of proteasome degradation, but not transcriptional regulation, of p27. Moreover, hCaMKIIN␣ deactivated MEK/ERK, which is prerequisite to the inhibition of Thr-187 phosphorylation and subsequent proteasomal degradation of p27, causing the inhibition of S-phase progression of cell cycle. The findings underscore a link between hCaMKIIN␣-mediated inhibition of CaMKII activity and p27-dependent pathways in controlling tumor cell growth and cell cycle and imply a potential application of hCaMKIIN␣ in the therapeutics of colon cancers.Calcium (Ca 2ϩ ) is a universal second messenger that regulates a broad range of cellular processes, including cell development, proliferation, motility, secretion, and others (1, 2). Members of the Ca 2ϩ /calmodulin (CaM) 3 -dependent protein kinase (CaMK) family are biochemical decoders of intracellular Ca 2ϩ oscillations (3, 4), among which CaMKII is a ubiquitous serine/ threonine protein kinase that phosphorylates nearly 40 different proteins, including enzymes, ion channels, kinases, and transcription factors (5, 6). Therefore, CaMKII is critical for many physiological and pathological functions of cells, and how to regulate CaMKII activity is an important question in the field of biomedicine.CaMKII inhibitors can block CaMKII activity by connecting Ca 2ϩ /CaM binding site or affecting its catalytic function. The CaMKII inhibitors used in the previous studies were the synthesized chemical reagents such as KN-62 (7) and KN-93 (8), or synthetic inhibitory peptide such as AIP (9). These inhibitors of CaMKII have been shown to inhibit CaMKII-dependent function in tumor cells, causing cell growth inhibition by impairment of cell cycle progression or induction of apoptosis (10 -13). The effect of CaMKII inhibitors on cell cycle was associated with changed expression levels of cell cycle-related proteins (6, 11). For example, treatment of HeLa cells with KN-93 results in a cell cycle blockade in the G 2 phase....

Neutrophils have a traditional role in inflammatory process and act as the first line of defense against infections. Although their contribution to tumorigenesis and progression is still controversial, accumulating evidence recently has demonstrated that tumor-associated neutrophils (TANs) play a key role in multiple aspects of cancer biology. Here, we detected that chemokine CXCL1 was dramatically elevated in serum from 3LL tumor-bearing mice. In vitro, 3LL cells constitutively expressed and secreted higher level of CXCL1. Furthermore, knocking down CXCL1 expression in 3LL cells significantly hindered tumor growth by inhibiting recruitment of neutrophils from peripheral blood into tumor tissues. Additionally, tumor-infiltrated neutrophils expressed higher levels of MPO and Fas/FasL, which may be involved in TAN-mediated inhibition of CD4+ and CD8+ T cells. These results demonstrate that tumor-derived CXCL1 contributes to TANs infiltration in lung cancer which promotes tumor growth.

Despite the increasing research attention paid to gestational diabetes mellitus (GDM) due to its high prevalence, limited knowledge is available about its pathogenesis. In this study, 428 serum samples were collected from 107 pregnant women suffering from GDM and 107 matched healthy controls. The nontargeted metabolomics data of maternal serum samples from the first (T1, n = 214) and second trimesters (T2, n = 214) were acquired by using ultrahigh performance liquid chromatography coupled with Orbitrap mass spectrometry (MS). A total of 93 differential metabolites were identified on the basis of the accurate mass and MS/MS fragmentation. After false discovery rate correction, the levels of 31 metabolites in GDM group were significantly altered in the first trimester. The differential metabolites were mainly attributed to purine metabolism, fatty acid β-oxidation, urea cycle, and tricarboxylic acid cycle pathways. The fold changes across pregnancy (T2/T1) of six amino acids (serine, proline, leucine/isoleucine, glutamic acid, tyrosine, and ornithine), a lysophosphatidylcholine (LysoPC(20:4)), and uric acid in GDM group were significantly different from those in the control groups, suggesting that these 8 metabolites might have contributed to the occurrence and progression of GDM. The findings revealed that the amino acid metabolism, lipid metabolism, and other pathways might be disturbed prior to GDM onset and during the period from the first to the second trimester of pregnancy.