[Show abstract][Hide abstract] ABSTRACT: A low partial oxygen pressure (hypoxia) occurs in many pathological environments, such as solid tumors and inflammatory lesions. Understanding the cellular response to hypoxic stress has broad implications for human diseases. As we previously reported, hypoxia significantly altered dendritic cells (DCs) to a DC2 phenotype and promoted a Th2 polarization of naïve T cells with increased IL-4 production. However, the underlying mechanisms still remain largely unknown. In this study, we found the over-expression of surface CD44 in DCs was involved in this process via ligand binding. Further investigation showed hypoxia could reduce the surface expression of membrane type 1 metalloprotease (MT1-MMP) via down-regulating the kinesin-like protein KIF2A, which subsequently alleviated the shedding of CD44 from DCs. Moreover, KIF2A expression was found negatively regulated by HIF-1α in hypoxic microenvironment. These results suggest a previously uncharacterized mechanism by which hypoxia regulates the function of DCs via KIF2A/MT1-MMP/CD44 axis, providing critical information to understand the immune response under hypoxia.
[Show abstract][Hide abstract] ABSTRACT: Previous studies have demonstrated that the overexpression of Kif2a is involved in the progression, invasion and metastasis of squamous cell carcinoma of the oral tongue (SCCOT). Few studies have reported the correlation between Kif2a and apoptosis of tumor cells and which signaling pathways Kif2a is involved in remains unclear. The phosphatidylinositol‑3‑kinase (PI3K)/protein kinase B (Akt) pathway is frequently activated in many types of human cancer. The aim of the present study was to investigate the effects of downregulation of Kif2 expression on the P13K/Akt pathway in Tca8113 cells to determine whether silencing of Kif2 inhibits the P13K/Akt pathway, resulting in cell apoptosis. siRNA vector was constructed, western blot analysis was used to determine RNA interference and flow cytometry was used to determine promotion of Tca8113 cell apoptosis. The results revealed that silencing Kif2a induces apoptosis and decreases the mRNA and protein level of PI3K, Akt and B‑cell lymphoma 2 (Bcl‑2) in Tca8113 cells. The PI3K-specific agonist insulin‑like growth factor 1 (IGF‑1) eliminated the upregulation of apoptosis of Tca8113‑Kif2a cells by phosphorylation of Akt. The results suggest that silencing Kif2a induces tumor cell apoptosis, at least partially, through the PI3K/Akt signaling pathway.
Molecular Medicine Reports 11/2013; 9(1). DOI:10.3892/mmr.2013.1804 · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the present study, a polysaccharide extract was obtained from Ocimum basilicum (basil polysaccharide, BPS) and the effects of curcumin and BPS on the invasion activity of the SKOV3 ovarian cancer cells and human monocyte‑derived dendritic cells (DCs) were investigated. SKOV3 cells and immature or mature DCs were treated with 50 µM curcumin or 100 µg/ml BPS. A transwell invasion assay demonstrated that curcumin and BPS differentially regulate the invasion of SKOV3 cells and DCs. Curcumin significantly decreased the invasion of SKOV3 cells and immature and mature DCs, while BPS only decreased SKOV3 cell invasion. Osteopontin (OPN) mRNA and protein expression were significantly reduced in curcumin and BPS‑treated SKOV3 cells and curcumin‑treated DCs. Furthermore, flow cytometry showed that curcumin significantly inhibited the surface expression of CD44 in SKOV3 cells and DCs, while BPS had a minimal effect on CD44 expression. Matrix metallopeptidase‑9 (MMP‑9) mRNA and protein expression were also reduced in all curcumin‑treated cells and BPS‑treated SKOV3 cells. The results indicated that curcumin and BPS regulated invasion of SKOV3 cells and DCs by distinctly downregulating OPN, CD44 and MMP‑9 expression. Therefore, Curcumin and BPS may be suitable candidates for DC‑based vaccines for ovarian cancer immunotherapy.
Molecular Medicine Reports 09/2013; 8(5). DOI:10.3892/mmr.2013.1695 · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Studies of maternal-fetal tolerance focus on defining mechanisms for establishment of immunological privilege within the uterus during pregnancy. Fetal trophoblasts play a key role in maternal tolerance, in part through cytokines production. As a novel inhibitory cytokine, IL-35 is produced by Foxp3(+) regulatory T cells (Tregs) and mediates maximal suppression of Tregs. The purpose of the study is to analyze the expression of IL-35 in first-trimester human placental trophoblasts. IL-35 expression was detected at both protein and mRNA levels by immunohistochemical staining and quantitative real-time PCR method, respectively and secretion of IL-35 was measured by ELISA assay. Our results demonstrated that human trophoblasts constitutively expressed IL-35. Ebi3 and p35 (two subunits of IL-35) mRNA was shown to be co-expressed in trophoblast cells. Moreover, large amounts of secreted IL-35 were detected in the supernatants of trophoblast cells. But we did not detect the constitutive expression of IL-35 in decidual stromal cells. Our findings confirmed for the first time that first-trimester human trophoblast cells expressed and secreted IL-35, which might contribute to their suppressive capacity to maternal immune cells. Therefore, IL-35 may be an important factor of the cytokine network regulating local immune responses during human pregnancy.
Human immunology 04/2013; 74(7). DOI:10.1016/j.humimm.2013.04.010 · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dihydroartemisinin (DHA), a semi-synthetic derivative and active metabolite of artemisinin, has been shown to have profound anticancer potential in addition to its strong anti-malarial activity. The purpose of the present study was to thoroughly investigate the anti-neoplastic effects induced by DHA and to provide a molecular basis for the use of DHA in the treatment of breast cancer. Our results demonstrated that DHA could significantly inhibit the cell proliferation of breast cancer in a dose- and time-dependent manner that was associated with induced apoptosis and G0/G1 cell cycle arrest, and the half maximal inhibitory concentrations (IC50) of DHA treatment were 60.03, 33.86 and 17.18 µM for 24, 48 and 72 h, respectively. Moreover, the DHA treatment dramatically increased the protein expression of caspase-8, cleaved caspase-9, activated Bid and induced the release of cytochrome c from mitochondria into the cytosol. In addition, the apoptotic action of DHA was associated with the increased expression of the pro-apoptotic gene Bim and a decreased expression of the anti-apoptotic gene Bcl-2. Therefore, the mitochondrial pathway is involved in the apoptosis of breast cancer cells induced by DHA and the imbalance of the Bim/Bcl-2 interaction may promote the beneficial effect against breast cancer cells. Overall, our study provides the scientific rationale for the clinical usage of DHA for breast cancer.
International Journal of Molecular Medicine 11/2012; 31(1). DOI:10.3892/ijmm.2012.1176 · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed to examine the effects of marchantin C and fucoidan on angiogenesis induced by glioma cells and monocytes, and to elucidate the role of sFlt-1 in this process.
T98G glioma cells and THP1 monocytes were pretreated with marchantin C or fucoidan, respectively. Conditioned media were used for endothelial cell tube formation assay and detection of sFlt-1 by ELISA. Depletion of sFlt-1 was achieved by a neutralizing antibody to assess its role in the process.
Marchantin C inhibited angiogenesis induced by T98G cells while fucoidan inhibited both T98G and THP1 cell-induced angiogenesis. In all three groups in which angiogenesis was inhibited, sFlt-1 level in the supernatants was elevated. Pretreatment of the conditioned media with sFlt-1 antibody restored the inhibited angiogenesis to a certain degree.
This study suggested for the first time that marchantin C and fucoidan could significantly inhibit angiogenesis induced by glioma cells or monocytes. Up-regulation of sFlt-1 played an important role in this process.
[Show abstract][Hide abstract] ABSTRACT: Tissue inhibitor of metalloproteinase-3 (TIMP-3) is one of a family of proteins inhibiting matrix metalloproteinases, which has also been identified as a mediator for checking inflammation. Meanwhile, it is well known that inflammation causes the activation of the immune response. However, it is not clear whether TIMP-3 plays a role in the immune system. In the present study, we demonstrated a novel function of TIMP-3 in Th1/Th2 polarization through its influence on the antigen-presenting cells. First, TIMP-3 was found strikingly up-regulated by IL-4 during the differentiation of human dendritic cells via the p38MAPK pathway. Second, the expression of costimulatory molecule-CD86 was repressed by TIMP-3. Besides, the induction of IL-12 in matured dendritic cells was significantly inhibited in a PI3K-dependent manner. Furthermore, dendritic cells matured in the presence of TIMP-3 could stimulate allogeneic naive T helper (Th) cells to display a prominent Th2 polarization. Importantly, in an autoimmune disorder-primary immune thrombocytopenia, TIMP-3 showed a statistically positive correlation with IL-4 and platelet count, but a negative correlation with IFN-γ in patient blood samples. Collectively, these in vitro and in vivo data clearly suggested a novel role of TIMP-3 in Th1/Th2 balance in humans.
[Show abstract][Hide abstract] ABSTRACT: Although human chemokinelike factor (CKLF)-like MAL and related proteins for vesicle trafficking transmembrane, domain-containing member 5 (CMTM5) has been proved to play an important role in carcinogenesis and apoptosis in several types of human tumors, the expression of CMTM5 in ovarian cancer remains unclear. We aimed to investigate the association between CMTM5 expression and the survival of patients with epithelial ovarian cancer.
Normal surface ovarian epithelium tissues, ovarian cystadenoma tissues, ovarian cancer tissues, and 5 ovarian cancer cell lines were collected. The CMTM5 expressions were determined by reverse transcription polymerase chain reaction, Western blotting, and immunohistochemical staining. The survival information was analyzed by the Kaplan-Meier method.
The CMTM5 expression was down-regulated in ovarian cancers. The expression of CMTM5 was absent in 30% (24 of 80) of ovarian cancers compared with 4.55% (1 of 22) of normal surface ovarian epithelium tissues and ovarian cystadenomas by immunohistochemistry. The results from the reverse transcription polymerase chain reaction were consistent with those from Western blotting. Furthermore, we found that although CMTM5 expression has no significant correlation with the age of the patients (P = 0.342), clinical stages (P = 0.155), pathologic types (P = 0.0605), or status of metastasis (P = 0.554), it was associated with the 3 groups of different differentiation levels (P = 0.0026) and an increase of CMTM5 loss of expression ratio in patients with preoperative CA125 level more than 500 mIU/mL compared to those with less than 500 mIU/mL (48.57% vs 16.67%, P = 0.0130). Statistical analysis by the Kaplan-Meier method showed that CMTM5 expression had no significant impact on the prognosis of patients with ovarian cancer (P = 0.24).
The reduced expression of CMTM5 correlates significantly with poorly differentiated ovarian cancer and high preoperative CA125 level. CMTM5 may contribute to the pathogenesis of human epithelial ovarian cancer.
International Journal of Gynecological Cancer 07/2011; 21(7):1248-55. DOI:10.1097/IGC.0b013e3182259c31 · 1.95 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hypoxia is a common characteristic of many pathological and physiological conditions that can markedly change cellular metabolism and cause the accumulation of extracellular adenosine. Recent studies have shown that adenosine can modulate the function of certain immune cell types through binding with different adenosine receptors. Our previous studies have shown that hypoxia has an effect on the biological activity of dendritic cells (DCs) by inducing their differentiation towards a Th2 polarising phenotype. However, the mechanisms underlying this suppression remain unclear. In this study, we have demonstrated that hypoxic mDCs predominantly express adenosine receptor A2b. The A2b receptor antagonist MRS1754 was able to increase the production of IL-12p70 and TNF-alpha by hypoxic mDCs and elevate the amount of Th1 cytokine IFN-gamma production in a mDCs-T-cell co-culture system. We also found that the effect of hypoxia on IL-12p70 production was mediated via increased intracellular cAMP levels through the up-regulation of A2b adenosine receptor and the preferential expression of adenosine A2b receptors in hypoxic mDCs was HIF-1 alpha dependent. Therefore, the hypoxic mDCs could provide a useful tool for researching the function of A2bR in human DCs. Our results offer new insights into understanding the molecular mechanisms underlying the biological activities of DCs in local-tissue hypoxic microenvironments.
[Show abstract][Hide abstract] ABSTRACT: It is well recognized that tissue microenvironments are involved in regulating the development and function of dendritic cells (DC). Oxygen supply, which varies in different tissues, has been accepted as an important microenvironmental factor in regulating the biological functions of several immune cells and as being involved in tumour progression and metastasis. However, little is known about the effect of hypoxia on the biological functions of DC and the effect of these hypoxia-conditioned DC on tumour metastasis. In this study, we analysed the transcriptional profiles of human monocyte-derived immature DC (imDC) and mature DC (mDC) cultured under normoxia and hypoxia by microarray, and found a body of potential targets regulating the functions of DC during hypoxia. In addition, the phagocytic ability of hypoxic imDC markedly decreased compared with that of normoxic imDC. Importantly, hypoxic DC poorly induced the proliferation of allogeneic T cells, but polarized allogeneic CD4(+) naive T cells into a T helper type 2 (Th2) response. Moreover, hypoxic DC secreted large amounts of osteopontin, which were responsible for the enhanced migration of tumour cells. Therefore, our study provides new insights into the biological functions of DC under hypoxic conditions and one of mechanisms underlying tumour immune escape during hypoxia.
[Show abstract][Hide abstract] ABSTRACT: Fucoidan is a complex sulfated polysaccharide with a wide variety of biological activities for modulating immune cell functions. However, the effects of fucoidan on maturation process and activation of human monocyte-derived dendritic cells (DCs) remain to be elucidated. The present study demonstrated that the level of special marks and polarization phenotype of DCs was altered by fucoidan. Human monocytes were cultured with GM-CSF and IL-4 for 5 days followed by another 2 days in the presence of fucoidan or LPS. Then DCs were harvested on day 7 and were examined using functional assays. We demonstrated that fucoidan up-regulated the expression of HLA-DR and co-stimulatory molecules of DCs. However the endocytic activity was impaired markedly. Fucoidan induces their Th1-promoting tumor necrosis factor alpha (TNF-alpha) and interleukin-12 (IL-12) secretion, and enhances their allostimulatory capacity. In an allogeneic MLR assay, DCs treated with fucoidan were potent in the secretion of IL-12p70, TNF-alpha and IFN-gamma. Naive T cells stimulated by fucoidan-treated DCs differentiated towards a helper T cell type 1 (Th1) response depending on IL-12 secretion. These results suggest that fucoidan may induce immature DCs maturation and drive their differentiation towards a Th1-polarizing phenotype. Moreover, our data suggest that DCs appear to be a potential target for the immunomodulatory capacity of fucoidan and fucoidan may be used on DC-based vaccines for cancer immunotherapy.
International Immunopharmacology 10/2008; 8(13-14):1754-60. DOI:10.1016/j.intimp.2008.08.007 · 2.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The involvement of the chemokine osteopontin has been proposed for maintaining successful pregnancy in mice and ruminants; however, little information of its function in human pregnancy is available. Osteopontin expression was assessed in decidua by RT-PCR and immunohistochemical staining in early pregnant women and RPL (recurrent pregnancy loss) patients. Osteopontin was expressed both in human decidual stromal cells and decidual natural killer (dNK) cells, and higher expression was detected in the later gestational phase compared to the early gestational phase. The osteopontin expression increased with pregnancy progression and higher osteopontin expression was correlated with a larger number of dNK cells. Compared with normal pregnancy, osteopontin expression and dNK cells accumulation were reduced significantly in RPL patients. Osteopontin expression was regulated by progesterone via an in vitro culture model. Our results indicated that osteopontin may play an important role in dNK recruitment and is an essential factor for successful pregnancy.
In vivo (Athens, Greece) 01/2008; 22(1):55-61. · 0.97 Impact Factor