RETRACTED: Up-regulating ribonuclease inhibitor inhibited epithelial-to-mesenchymal transition and metastasis in murine melanoma cells

Update on the Use of Intravenous Immunoglobulin in Pregnancy

Intravenous immunoglobulin (IVIG) was first administered to humans in the 1980s. The mechanism of action of IVIG is still a subject of debate but the pharmacokinetics have been well characterized, albeit outside of pregnancy. IVIG has been used in pregnancy to treat several nonobstetrical and obstetrical-related conditions. However, current evidence suggests that IVIG use during pregnancy can be recommended for 1) in utero diagnosis of neonatal alloimmune thrombocytopenia; 2) gestational alloimmune liver disease; 3) hemolytic disease of the fetus and newborn for early-onset severe intrauterine disease; 4) antiphospholipid syndrome (APS) when refractory to or contraindicated to standard treatment, or in catastrophic antiphospholipid syndrome; and 5) immune thrombocytopenia when standard treatment is ineffective or rapid increase of platelet counts is needed. All recommendations are based on case series and cohort studies without randomized trials usually because of the rare prevalence of the conditions, the high incidence of adverse outcomes if left untreated, and ethical concerns. In contrast, IVIG therapy cannot be recommended for recurrent pregnancy loss, and the use of IVIG in subgroups of those with recurrent pregnancy loss requires further investigations. For non-obstetrical-related conditions, we recommend using IVIG as indicated for nonpregnant patients. In conclusion, the use of IVIG during pregnancy is an effective treatment in some obstetrical-related conditions with rare serious maternal side effects. However, the precise mechanisms of action and the long-term immunologic effects on the fetus and neonate are poorly understood and merit further investigations.

Overexpression of ribonuclease inhibitor induces autophagy in human colorectal cancer cells via the Akt/mTOR/ULK1 pathway

Ribonuclease inhibitor (RI), also termed angiogenin inhibitor, acts as the inhibitor of ribonucleolytic activity of RNase A and angiogenin. The expression of RI has been investigated in melanoma and bladder cancer cells. However, the precise role of RI in tumorigenesis, in addition to RI‑induced autophagy, remains poorly understood. In the present study, it was demonstrated that RI positively regulated autophagy in human colorectal cancer (CRC) cells as indicated by an increase in light chain 3 (LC3)‑II levels. Furthermore, RI regulated cell survival in HT29 cells. In addition, autophagy‑associated proteins, including beclin‑1 and autophagy‑related protein 13, were increased in response to RI‑induced autophagy, and the protein kinase B (Akt)/mechanistic target of rapamycin (mTOR)/Unc‑51 like autophagy activating kinase (ULK1) pathway may be involved in the activation of autophagy induced by RI overexpression. Taken together, the evidence of the present study indicated that the overexpression of RI induced ATG‑dependent autophagy in CRC cells via the Akt/mTOR/ULK1 pathway, suggesting that the upregulation of RI activity may constitute a novel approach for the treatment of human colorectal carcinoma.

lncRNA H19 regulates epithelial-mesenchymal transition and metastasis of bladder cancer by miR-29b-3p as competing endogenous RNA

Accumulating evidences indicate that long noncoding RNAs (lncRNAs) might play important roles in tumorigenesis and metastasis. EMT (epithelial-to-mesenchymal transition) is considered as a critical step in invasion and metastasis of various tumors including bladder cancer (BC). Recent researches have showed that lncRNA H19 is implicated in metastasis through regulating EMT and the reverse MET (mesenchymal-to-epithelial transition). However, underlying mechanisms remain largely unknown. Here, we screened lncRNA and mRNA expression profiles of BC with microarray assay. We found that H19 and DNMT3B displayed a higher co-expression in BC tissues and cells. Functionally, we demonstrated that H19 could increase proliferation, invasion and migration, regulate EMT as well as rearrange cytoskeleton of BC cells in vitro. Moreover, ectopic expression of H19 promoted tumorigenesis, angiogenesis and pulmonary metastasis in vivo, whereas knockdown of H19 has a contrary role in vivo and in vitro. Mechanistically, we proved that H19 could directly bind to miR-29b-3p (miR-29b) and derepress the expression of target DNMT3B. H19 and miR-29b-3p showed a co-localization. More importantly, up-regulating H19 antagonized miR-29b-3p-mediated proliferation, migration and EMT suppression in BC cells. Furthermore, H19 knockdown partially reversed the function of miR-29b-3p inhibitor on DNMT3B and facilitated miR-29b-3p-induced MET. Taken together, we demonstrated for the first time that H19 might function as ceRNA (competing endogenous RNA) for miR-29b-3p and relieve the suppression for DNMT3B, which led to EMT and metastasis of BC. Our findings highlight a novel mechanism of H19 in progression of BC and provide H19/miR-29b-3p/DNMT3B axis as a promising therapeutic target for BC.

Interplay between intergrin-linked kinase and ribonuclease inhibitor affects growth and metastasis of bladder cancer through signaling ILK pathways

Background

Integrin-linked kinase (ILK) is a multifunctional adaptor protein which is involved with protein signalling within cells to modulate malignant (cancer) cell movement, cell cycle, metastasis and epithelial–mesenchymal transition (EMT). Our previous experiment demonstrated that ILK siRNA inhibited the growth and induced apoptosis of bladder cancer cells as well as increased the expression of Ribonuclease inhibitor (RI), an important cytoplasmic protein with many functions. We also reported that RI overexpression inhibited ILK and phosphorylation of AKT and GSK3β. ILK and RI gene both locate on chromosome 11p15 and the two genes are always at the adjacent position of same chromosome during evolution, which suggest that ILK and RI could have some relationship. However, underlying interacting mechanisms remain unclear between them. Here, we postulate that RI might regulate ILK signaling pathway via interacting with ILK.

Methods

Co-immunoprecipitation, GST pull-down and co-localization under laser confocal microscope assay were used to determine the interaction between ILK and RI exogenously and endogenously. Furthermore, we further verified that there is a direct binding between the two proteins by fluorescence resonance energy transfer (FRET) in cells. Next, The effects of interplay between ILK and RI on the key target protein expressions of PI3K/AKT/mTOR signaling pathway were determined by western blot, immunohistochemistry and immunofluorescence assay in vivo and in vitro. Finally, the interaction was assessed using nude mice xenograft model.

Results

We first found that ILK could combine with RI both in vivo and in vitro by GST pull-down, co-immunoprecipitation (Co-IP) and FRET. The protein levels of ILK and RI revealed a significant inverse correlation in vivo and in vitro. Subsequently, The results showed that up-regulating ILK could increase cell proliferation, change cell morphology and regulate cell cycle. We also demonstrated that the overexpression of ILK remarkably promoted EMT and expressions of target molecules of ILK signaling pathways in vitro and in vivo. Finally, we found that ILK overexpression significantly enhanced growth, metastasis and angiogenesis of xenograft tumor; Whereas, RI has a contrary role compared to ILK in vivo and in vitro.

Conclusions

Our findings, for the first time, directly proved that the interplay between ILK and RI regulated EMT via ILK/PI3K/AKT signaling pathways for bladder cancer, which highlights the possibilities that ILK/RI could be valuable markers together for the therapy and diagnosis of human carcinoma of urinary bladder.

Screening differential circular RNA expression profiles reveals the regulatory role of circTCF25-miR-103a-3p/miR-107-CDK6 pathway in bladder carcinoma

Circular RNAs (circRNAs), a kind of non-coding RNAs, have shown large capabilities in gene regulation. However, the mechanisms underlying circRNAs remain largely unknown so far. Recent studies demonstrated that circRNAs play miRNA sponge effects and regulate gene expression by microRNA response elements. Here, we screened circRNA expression profiles of bladder carcinoma using microarray assay. A total of 469 dysregulated circular transcripts are found in bladder cancer compared with normal tissues, among which 285 were up-regulated and 184 were down-regulated. Six circRNAs were identified to have significant differences by qRT-PCR. We speculated that circRNAs might involve in cancer-related pathways via interactions with miRNA by multiple bioinformatical approaches. Therefore, we further predicted that circTCF25 could sequester miR-103a-3p/miR-107, which potentially lead to the up-regulation of thirteen targets related to cell proliferation, migration and invasion. Subsequently, we demonstrated that over-expression of circTCF25 could down-regulate miR-103a-3p and miR-107, increase CDK6 expression, and promote proliferation and migration in vitro and vivo. This is the first study to exploit circRNA profiling and circRNA/miRNA interactions in bladder cancer. Our work laid the foundation to investigate the functions of circRNAs in cancers. The data also suggest that circTCF25 might be a new promising marker for bladder cancer.

Erythrocyte Membrane-Enveloped Polymeric Nanoparticles as Nanovaccine for Induction of Antitumor Immunity against Melanoma

Cancer immunotherapy is mainly focused on manipulating patient's own immune system to recognize and destroy cancer cells. Vaccine formulations based on nanotechnology have been developed to target delivery antigens to antigen presenting cells (APCs), especially dendritic cells (DCs) for efficiently induction of antigen-specific T cells response. To enhance DC targeting and antigen presenting efficiency, we developed erythrocyte membrane-enveloped poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles for antigenic peptide (hgp10025-33) and toll-like receptor 4 agonist, monophosphoryl lipid (MPLA). A Mannose-inserted membrane structure was constructed to actively target APCs in the lymphatic organ, and redox-sensitive peptide-conjugated PLGA nanoparticles were fabricated which prone to cleave in the intracellular milieu. The nanovaccine demonstrated the retained protein content in erythrocyte and enhanced in vitro cell uptake. An antigen-depot effect was observed in the administration site with promoted retention in draining lymph nodes. Compared with other formulations after intradermal injection, the nanovaccine prolonged tumor-occurring time, inhibited tumor growth, and suppressed tumor metastasis in prophylactic, therapeutic, and metastatic melanoma models, respectively. Additionally, we revealed that nanovaccine effectively enhanced IFN-γ secretion and CD8(+) T cell response. Taken together, these results demonstrated the great potential in applying an erythrocyte membrane-enveloped polymeric nanoplatform for an antigen delivery system in cancer immunotherapy.

B-Myb regulates snail expression to promote epithelial-to-mesenchymal transition and invasion of breast cancer cell

Breast cancer is the leading cause of cancer death in women worldwide, which is closely related to metastasis. Recent studies argue that breast cancer cells that have undergone epithelial-to-mesenchymal transition (EMT) acquire aggressive malignant properties, but the molecular mechanisms underlying this transition are poorly understood. In this study, we found that siRNA-mediated attenuation of B-Myb expression restored E-cadherin expression and cell-cell junction formation in breast cancer cells, suppressing cell invasion, anchorage-independent growth, and tumor formation. In contrast, the forced B-Myb expression decreased the expression of the epithelial marker E-cadherin, but increased the mesenchymal markers in breast cancer cells. We found that B-Myb upregulated expression of the key EMT regulator snail and that it mediated EMT activation and cell invasion by B-Myb.

Stress granules, P-bodies and cancer

Cancer cells are exposed to adverse conditions in the tumor microenvironment, and utilize post-transcriptional control mechanisms to re-program gene expression in ways that enhance cell survival. Stress granules and processing bodies are RNA-containing granules that contribute to this process by modulating cellular signaling pathways, metabolic machinery, and stress response programs. This review examines evidence implicating RNA granules in the pathogenesis of cancer and discusses their potential as targets for anticancer therapies. This article is part of a Special Issue entitled: Translation and Cancer.

Overexpression of ribonuclease inhibitor defines good prognosis and suppresses proliferation and metastasis in human colorectal cancer cells via PI3K/AKT pathway

PURPOSE

We aim to evaluate the diagnostic value of ribonuclease inhibitor (RI) in colorectal cancer (CRC) and investigate the important role of RI in cell growth and metastasis of CRC.

METHODS/PATIENTS

In this study, the expression of RI was evaluated in human CRC samples with different histological grade and the association between RI expression and clinicopathological parameters was investigated. Furthermore, the exogenous RI gene was introduced into human HT29 CRC cells and the effects of RI on cell proliferation and metastasis were determined in vitro. The PI3K/Akt signaling pathway and some related protein molecules were detected.

RESULTS

RI is downregulated in CRC tissues compared to adjacent normal tissues and its expression is inversely associated with histological grade, pathological stage, and venous invasion, respectively. Multivariate analysis showed that RI expression was an independent prognostic factor for overall survival. In addition, the exogenous overexpression of RI reduced the proliferation and migration of HT29 CRC cell line in vitro by inhibiting the PI3K/Akt signaling pathway and suppressing the expression of vascular endothelial growth factor (VEGF) and upregulating phosphatase and tensin homolog (PTEN).

CONCLUSIONS

RI represents an important predictor of progression in patients with CRC and suppresses proliferation and metastasis in CRC cells through inhibiting PI3K/AkT pathway.

Angiogenin interacts with ribonuclease inhibitor regulating PI3K/AKT/mTOR signaling pathway in bladder cancer cells

Angiogenin (ANG), a member of RNase A superfamily, is the only angiogenic factor that possesses ribonucleolytic activity. Recent studies showed that the expression of ANG was elevated in various types of cancers. Accumulating evidence indicates that ANG plays an essential role in cancer progression by stimulating both cancer cell proliferation and tumor angiogenesis. Human ribonuclease inhibitor (RI), a cytoplasmic protein, is constructed almost entirely of leucine rich repeats (LRRs), which are present in a large family of proteins that are distinguished by their display of vast surface areas to foster protein-protein interactions. RI might be involved in unknown biological effects except inhibiting RNase A activity. The experiment demonstrated that RI also could suppress activity of angiogenin (ANG) through closely combining with it in vitro. PI3K/AKT/mTOR signaling pathway exerts a key role in cell growth, survival, proliferation, apoptosis and angiogenesis. We recently reported that up-regulating RI inhibited the growth and induced apoptosis of murine melanoma cells through repression of angiogenin and PI3K/AKT signaling pathway. However, ANG receptors have not yet been identified to date, its related signal transduction pathways are not fully clear and underlying interacting mechanisms between RI and ANG remain largely unknown. Therefore, we hypothesize that RI might combine with intracellular ANG to block its nuclear translocation and regulate PI3K/AKT/mTOR signaling pathway to inhibit biological functions of ANG. Here, we reported for the first time that ANG could interact with RI endogenously and exogenously by using co-immunoprecipitation (Co-IP) and GST pull-down. Furthermore, we observed the colocalization of ANG and RI in cells with immunofluorescence staining under laser confocal microscope. Moreover, through fluorescence resonance energy transfer (FRET) assay, we further confirmed that these two proteins have a physical interaction in living cells. Subsequently, we demonstrated that up-regulating ANG including ANG His37Ala mutant obviously decreased RI expression and activated phosphorylation of key downstream target molecules of PI3K/AKT/mTOR signaling pathway. Finally, up-regulating ANG led to the promotion of tumor angiogenesis, tumorigenesis and metastasis in vivo. Taken together, our data provided a novel mechanism of ANG in regulating PI3K/AKT/mTOR signaling pathway via RI, which suggested a new therapeutic target for cancer therapy.

Down-regulating ribonuclease inhibitor enhances metastasis of bladder cancer cells through regulating epithelial-mesenchymal transition and ILK signaling pathway

Accumulating evidences implicate that ribonuclease inhibitor (RI) plays a suppressing role in cancer development. However, the mechanisms underlying antitumor of RI remain largely unknown. Epithelial-mesenchymal transition (EMT) is regarded as a key event in tumor progression. The reports have demonstrated that EMT was implicated in metastasis of bladder cancer. Therefore, we suppose that RI might involve regulating EMT of bladder cancer. Here bladder cancer T24 cells were transfected with pGensil-1-siRNA-RI vectors. HE staining, living cell observation, Phalloidine-FITC staining of microfilament, cell adhesion, scratch migration, and Matrigel invasion were examined respectively. RI expression and colocalization with ILK were detected using confocal microscope. Proteins associated with EMT were determined with Western blotting and immunohistochemistry in vivo and in vitro. Effects of RI expression on tumor growth, metastasis and EMT related proteins in BALB/C nude mouse and clinical human bladder cancer specimens were valued with histological, immunohistochemical and immunofluorescent examination respectively. We demonstrated that down-regulating RI increased cell proliferation, migration and invasion, changed cell morphology and adhesion, and rearranged cytoskeleton by inducing EMT and ILK signaling pathway in bladder cancer cells. In addition, we showed that down-regulating RI promoted tumorigenesis and metastasis of bladder cancer in vivo. Finally, we found that bladder cancer with invasive capability had higher Vimentin, Snail, Slug and Twist as well as lower E-cadherin and RI expression in clinical human specimens. Our results suggest that RI could play a novel role in inhibiting metastasis of bladder through regulating EMT and ILK signaling pathway.

Angiogenin interacts with the plasminogen activation system at the cell surface of breast cancer cells to regulate plasmin formation and cell migration

Angiogenin (ANG), a 14-kDa pro-angiogenic secreted protein, has been shown to play a role in cell migration and tumor invasion, which involve proteolytic cleavage of plasminogen to generate plasmin. However, the mechanism by which ANG regulates plasmin formation and cell migration was not known. Our studies here detected elevated levels of secreted and cell surface-bound ANG in highly invasive metastatic breast cancer cells. ANG was also detected at very high levels in the tumor cells in infiltrating ductal carcinomas. By immunofluorescence and immunoprecipitation analysis, ANG was detected at the leading edges of the cell surfaces where it colocalized and interacted with members of the plasminogen activation system (PAS) such as annexin A2 (A2), calpactin (S100-A10) and urokinase plasminogen activator receptor (uPAR). Analysis of lipid raft (LR) and non-lipid raft (NLR) regions of the cell membranes showed the predominance of ANG, A2 and S100-A10 in the LR regions. In contrast, uPAR was detected predominantly in the NLR fractions, suggesting that ANG interacts with uPAR at the junctions of LR and NLR regions. ANG knockdown in T47D and MDA-MB-231 breast cancer cell lines did not affect the cellular expression of A2, S100-A10 and uPAR but decreased cell migration and plasmin formation. Neutralization of ANG with monoclonal antibodies similarly decreased the migration of MDA-MB-231 cells. In the presence of ANG, uPAR was observed to interact with uPA, which is necessary for plasmin formation. Conversely, in the absence of ANG, uPAR did not interact with uPA and FAK and Src kinases were observed to be dephosphorylated. Exogenous addition of recombinant ANG to ANG knocked down MDA-MB-231 cells restored FAK phosphorylation, uPAR interactions with uPA, plasmin formation as well as migration of these cells. Taken together, our results identified a novel role for ANG as a member of the uPAR interactome that facilitates the interaction of uPAR with uPA, leading to plasmin formation and cell migration necessary for tumor invasion and metastasis of breast cancer cells.

A novel role of ribonuclease inhibitor in regulation of epithelial-to-mesenchymal transition and ILK signaling pathway in bladder cancer cells

Human ribonuclease inhibitor (RI) is a cytoplasmic acidic protein possibly involved in biological functions other than the inhibition of RNase A and angiogenin activities. We have previously shown that RI can inhibit growth and metastasis in some cancer cells. Epithelial-mesenchymal transition (EMT) is regarded as the beginning of invasion and metastasis and has been implicated in the metastasis of bladder cancer. We therefore postulate that RI regulates EMT of bladder cancer cells. We find that the over-expression of RI induces the up-regulation of E-cadherin, accompanied with the decreased expression of proteins associated with EMT, such as N-cadherin, Snail, Slug, vimentin and Twist and of matrix metalloprotein-2 (MMP-2), MMP-9 and Cyclin-D1, both in vitro and in vivo. The up-regulation of RI inhibits cell proliferation, migration and invasion, alters cell morphology and adhesion and leads to the rearrangement of the cytoskeleton in vitro. We also demonstrate that the up-regulation of RI can decrease the expression of integrin-linked kinase (ILK), a central component of signaling cascades controlling an array of biological processes. The over-expression of RI reduces the phosphorylation of the ILK downstream signaling targets p-Akt and p-GSK3β in T24 cells. We further find that bladder cancer with a high-metastasis capability shows higher vimentin, Snail, Slug and Twist and lower E-cadherin and RI expression in human clinical specimens. Finally, we provide evidence that the up-regulation of RI inhibits tumorigenesis and metastasis of bladder cancer in vivo. Thus, RI might play a novel role in the development of bladder cancer through regulating EMT and the ILK signaling pathway.