NRBP2 Overexpression Increases the Chemosensitivity of Hepatocellular Carcinoma Cells via Akt Signaling

Analysis of prognostic value of lactate metabolism-related genes in ovarian cancer based on bioinformatics

BACKGROUND

Recent studies have provided evidence supporting the functional role and mechanism of lactate in suppressing anticancer immunity. However, there is no systematic analysis of lactate metabolism-related genes (LMRGs) and ovarian cancer (OV) prognosis.

RESULTS

Six genes (CCL18, CCND1, MXRA5, NRBP2, OLFML2B and THY1) were selected as prognostic genes and a prognostic model was utilized. Kaplan-Meier (K-M) and Receiver Operating Characteristic (ROC) analyses were further performed and indicated that the prognostic model was effective. Subsequently, the neoplasm_cancer_status and RiskScore were determined as independent prognostic factors, and a nomogram was established with relatively accurate forecasting ability. Additionally, 2 types of immune cells (Central memory CD8 T cell and Immature B cell), 4 types of immune functions (APC co inhibition, DCs, Tfh and Th1 cells), 9 immune checkpoints (BTLA, CTLA4, IDO1, LAG3, VTCN1, CXCL10, CXCL9, IFNG, CD27) and tumor immune dysfunction and exclusion (TIDE) scores were significantly different between risk groups. The expression of 6 genes were verified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and the expression of 6 genes were higher in the high-grade serous carcinoma (HGSC) samples.

CONCLUSION

A prognostic model related to lactate metabolism was established for OV based on six genes (CCL18, CCND1, MXRA5, NRBP2, OLFML2B and THY1) that could provide new insights into therapy.

FXYD5 promotes sorafenib resistance through the Akt/mTOR signaling pathway in hepatocellular carcinoma

Tumor chemoresistance is often a major cause for the failure of chemotherapy. The resistance of hepatocellular carcinoma (HCC) cells to sorafenib significantly limits its therapeutic effect in HCC patients. For the first time, we found that FXYD domain-containing ion transport regulator 5 (FXYD5) is highly expressed in sorafenib-resistant HCC cells. In addition, the protein expression level of FXYD5 was markedly higher in HCC tissues than in paracancerous tissues. Remarkably, downregulation of FXYD5 expression in Huh7/sora cells reversed their resistance to sorafenib. Moreover, overexpression of FXYD5 reduced the sensitivity of HCC cells to sorafenib, while the downregulation of its expression in HCC cells had the opposite effect. We also found abnormal activation of the Akt/mTOR signaling pathway in Huh7/sora cells. Furthermore, MK2206, an Akt inhibitor, was found to significantly increase the sensitivity of HCC cells to sorafenib. More importantly, the expression level of p-Akt was positively correlated with the expression of FXYD5 in HCC tissues. Therefore, mechanistically, FXYD5 enhances the resistance of HCC cells to sorafenib by activating the Akt/mTOR signaling pathway. In conclusion, this study showed that the activation of the FXYD5/Akt/mTOR signaling axis plays key role in the resistance of HCC cells to sorafenib, and FXYD5 may represent a new potential target for HCC therapy.

TRG16, targeted by miR-765, inhibits breast cancer stem cell-like properties via regulating the NF-κB pathway

Previous studies reported that cancer stem cells (CSCs) might be responsible for drug resistance and cancer progression. Transformation-Related Gene 16 Protein (TRG16), a pseudokinase, was reported to be a suppressor in some types of cancer and its overexpression impaired hepatocellular carcinoma cell stemness. However, the function of TRG16 in BC remains unclear. We found that TRG16 expression was significantly downregulated in BC tissues compared with adjacent tissues (n = 40; P < 0.001) and BC patients with lower expression of TRG16 had a worse prognosis. Forced expression of TRG16 inhibited BC stem cell-like properties as evidenced by decreased CD44-positive cells (CSC marker), reduced mammosphere quantity, and downregulated Nanog, aldehyde dehydrogenase, octamer-binding transcription factor 4, and SRY-box transcription factor 2 expression (CSC markers). Moreover, TRG16 overexpression inhibited self-renewal and invasion capabilities of BC cells in vitro as well as tumor growth in vivo but increased cisplatin sensitivity. However, TRG16 silencing had the opposite effects. Further mechanistic studies revealed that TRG16 was targeted and negatively regulated by miR-765, a facilitator of BC progression. TRG16 could suppress the activation of the NF-κB pathway in BC cells, which is a positive pathway in BC progression and contributes to the maintenance of cancer cell stemness. In conclusion, the results above demonstrate that TRG16, negatively regulated by miR-765, may inhibit the BC progression by regulating BC stem cell-like properties and this inhibition may be mediated by the NF-κB pathway. Our findings indicate that TRG16 may be a potential therapeutic targetable node for BC. TRG16, negatively regulated by miR-765, may inhibit the BC progression through regulating BC stem cell-like properties and this inhibition may be mediated by the NF-κB pathway.

GATA binding protein 1 recruits histone deacetylase 2 to the promoter region of nuclear receptor binding protein 2 to affect the tumor microenvironment and malignancy of thyroid carcinoma

The tumor microenvironment (TME) and activated angiogenesis in thyroid carcinoma (TC) are critical for tumor growth and metastasis. Nuclear receptor binding protein 2 (NRBP2) has been suggested as a tumor suppressor. This study examines the function of NRBP2 in the progression of TC and the regulatory mechanism. By analyzing bioinformatic tools including GSE165724 dataset and the Cancer Genome Atlas system, we predicted NRBP2 as a poorly expressed gene in TC. Decreased NRBP2 expression was detected in TC tumor tissues and cells. Poor expression of NRBP2 was linked to unfavorable prognosis of patients. GATA binding protein 1 (GATA1) was found as a negative regulator of NRBP2. It recruited histone deacetylase2 (HDAC2) to the NRBP2 promoter to trigger histone deacetylation. NRBP2 overexpression suppressed growth of TC cells, and it reduced expression of TME markers, M2 polarization of macrophages, and angiogenesis in TC. Similar results were reproduced in vivo in nude mice. However, the anti-oncogenic roles of NRBP2 were blocked after further overexpression of GATA1 or HDAC2. In summary, this study demonstrates that GATA1 recruits HDAC2 to the NRBP2 promoter and enhances the TME and angiogenesis in TC cells.

LncRNA LINC00281/Annexin A2 Regulates Vascular Smooth Muscle Cell Phenotype Switching via the Nuclear Factor-Kappa B Signaling Pathway

Abnormal phenotype switch in vascular smooth muscle cells (VSMCs) plays an important role in the initiation and progression of vascular proliferative diseases. Annexin A2 (ANXA2), related to the pro-inflammatory response, contributes to the proliferation and migration of VSMCs. This study explored the mechanisms involved in the regulation of VSMC phenotype modulation via ANXA2. The results revealed that ANXA2 promotes the phosphorylation of p65 and co-translocates with p65 into the nucleus, resulting in VSMC proliferation, migration, and dedifferentiation. Based on bioinformatics predictions and RNA immunoprecipitation assays, LINC00281 was confirmed to be an upstream regulator of ANXA2. Taken together, ANXA2, which is negatively regulated by the long noncoding RNA (lncRNA) LINC00281, has significant importance in the regulation of VSMC proliferation, migration, and phenotype switching via the nuclear factor-kappa B (NF-кB) p65 signaling pathway. This indicates that the lncRNA LINC00281/ANXA2/NF-кB p65 signaling pathway might be a new therapeutic target for vascular proliferative diseases.

Ali M, Mesbah NM, Abo-Elmatty DM, Abdel-Hamed AR. Cyanidin-3-Glucoside Modulates hsa_circ_0001345/miRNA106b/ATG16L1 Axis Expression as a Potential Protective Mechanism against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common form of malignancy in the liver. Autophagy was found to have a significant effect in controlling HCC. Anthocyanins, which are naturally occurring pigments in a variety of fruits and vegetables, have been thoroughly documented to be involved in a variety of bioactive activities and are widely employed for their antioxidant capabilities. Cyanidin-3-glucoside (C3G) extracted from Morus alba L. has promising antioxidant and anti-tumour activities. The current study aims to examine the protective action of C3G against hepatocellular carcinoma through the investigation of the autophagy protein ATG16L1 expression along with its related RNA molecules (hsa_circ_0001345 and miRNA106b) in Wistar rats. In vivo precancerous lesions (PCL) were induced using diethylnitrosamine (DEN) and acetamidofluorene (2-AAF). Rats were treated with C3G (10, 15, and 20 mg/kg; 4 times weekly) for 112 days (16 weeks). Liver function tests, alfa fetoprotein, ATG16L1 expression, hsa_circ_0001345, and miRNA106b differential expression were examined. Liver sections were examined by histological and immunohistochemical approaches. The current study’s findings indicated that C3G administration protects against the negative effects of DEN-2-AAF on liver functions and liver histopathological sections, which nominated C3G as a potential prophylactic agent against HCC.

Suppression of RNA editing by miR-17 inhibits the stemness of melanoma stem cells

More and more evidence suggests that microRNA (miRNA) and RNA editing play key roles in the development and progression of tumor. However, the influence of miRNA-mediated RNA editing on tumor stem cells remains unclear. In this study, the results demonstrated that miR-17, which was downregulated in melanoma stem cells, acted as a tumor inhibitor by suppressing the stemness of melanoma stem cells and promoting cell differentiation. MiR-17 targeted ADAR2 (adenosine deaminase acting on RNA 2), a gene encoding an editing enzyme required for the maintenance of melanoma stem cell stemness. In melanoma stem cells, ADAR2 was responsible for DOCK2 mRNA editing, which was able to increase the stability of DOCK2 mRNA. The in vitro and in vivo data demonstrated that DOCK2 mRNA editing upregulated the expressions of stemness and anti-apoptotic genes by activating Rac1 and then phosphorylating Akt and NF-κB, thus leading to oncogenesis of melanoma stem cells. Our findings contribute new perspectives to miRNA-regulated RNA editing in tumor progression.

Nrf2 signaling promotes cancer stemness, migration, and expression of ABC transporter genes in sorafenib-resistant hepatocellular carcinoma cells

Background and aim

As a multiple tyrosine kinase inhibitor, sorafenib is widely used to treat hepatocellular carcinoma (HCC), but patients frequently face resistance problems. Because the mechanism controlling sorafenib-resistance is not well understood, this study focused on the connection between tumor characteristics and the Nrf2 signaling pathway in a sorafenib-resistant HCC cell line.

Methods

A sorafenib-resistant HCC cell line (Huh7) was developed by increasing the dose of sorafenib in the culture medium until the target concentration was reached. Cell morphology, migration/invasion rates, and expression of stemness-related and ATP-binding cassette (ABC) transporter genes were compared between sorafenib-resistant Huh7 cells and parental Huh7 cells. Next, a small interfering RNA was used to knock down Nrf2 expression in sorafenib-resistant Huh7 cells, after which cell viability, stemness, migration, and ABC transporter gene expression were examined again.

Results

Proliferation, migration, and invasion rates of sorafenib-resistant Huh7 cells were significantly increased relative to the parental cells with or without sorafenib added to the medium. The expression levels of stemness markers and ABC transporter genes were up-regulated in sorafenib-resistant cells. After Nrf2 was knocked down in sorafenib-resistant cells, cell migration and invasion rates were reduced, and expression levels of stemness markers and ABC transporter genes were reduced.

Conclusion

Nrf2 signaling promotes cancer stemness, migration, and expression of ABC transporter genes in sorafenib-resistant HCC cells.

Y-box binding protein 1 augments sorafenib resistance via the PI3K/Akt signaling pathway in hepatocellular carcinoma

BACKGROUND

Sorafenib is the first-line treatment for patients with advanced hepatocellular carcinoma (HCC). Y-box binding protein 1 (YB-1) is closely correlated with tumors and drug resistance. However, the relationship between YB-1 and sorafenib resistance and the underlying mechanism in HCC remain unknown.

AIM

To explore the role and related mechanisms of YB-1 in mediating sorafenib resistance in HCC.

METHODS

The protein expression levels of YB-1 were assessed in human HCC tissues and adjacent nontumor tissues. Next, we constructed YB-1 overexpression and knockdown hepatocarcinoma cell lines with lentiviruses and stimulated these cell lines with different concentrations of sorafenib. Then, we detected the proliferation and apoptosis in these cells by terminal deoxynucleotidyl transferase dUTP nick end labeling, flow cytometry and Western blotting assays. We also constructed a xenograft tumor model to explore the effect of YB-1 on the efficacy of sorafenib in vivo. Moreover, we studied and verified the specific molecular mechanism of YB-1 mediating sorafenib resistance in hepatoma cells by digital gene expression sequencing (DGE-seq).

RESULTS

YB-1 protein levels were found to be higher in HCC tissues than in corresponding nontumor tissues. YB-1 suppressed the effect of sorafenib on cell proliferation and apoptosis. Consistently, the efficacy of sorafenib in vivo was enhanced after YB-1 was knocked down. Furthermore, KEGG pathway enrichment analysis of DGE-seq demonstrated that the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was essential for the sorafenib resistance induced by YB-1. Subsequently, YB-1 interacted with two key proteins of the PI3K/Akt signaling pathway (Akt1 and PIK3R1) as shown by searching the BioGRID and HitPredict websites. Finally, YB-1 suppressed the inactivation of the PI3K/Akt signaling pathway induced by sorafenib, and the blockade of the PI3K/Akt signaling pathway by LY294002 mitigated YB-1-induced sorafenib resistance.

CONCLUSION

Overall, we concluded that YB-1 augments sorafenib resistance through the PI3K/Akt signaling pathway in HCC and suggest that YB-1 is a key drug resistance-related gene, which is of great significance for the application of sorafenib in advanced-stage HCC.

The mechanisms of renin-angiotensin system in hepatocellular carcinoma: From the perspective of liver fibrosis, HCC cell proliferation, metastasis and angiogenesis, and corresponding protection measures

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, of which the occurrence and development involve a variety of pathophysiological processes, such as liver fibrosis, hepatocellular malignant proliferation, metastasis, and tumor angiogenesis. Some important cytokines, such as TGF-β, PI3K, protein kinase B (Akt), VEGF and NF-κB, can regulate the growth, proliferation, diffusion, metastasis, and apoptosis of HCC cells by acting on the corresponding signaling pathways. Besides, many studies have shown that the formation of HCC is closely related to the main components of renin-angiotensin system (RAS), such as Ang II, ACE, ACE2, MasR, AT1R, and AT2R. Therefore, this review focused on liver fibrosis, HCC cell proliferation, metastasis, tumor angiogenesis, and corresponding protective measures. ACE-Ang II-AT1 axis and ACE2-Ang-(1-7)-MasR axis were taken as the main lines to introduce the mechanism of RAS in the occurrence and development of HCC, so as to provide references for future clinical work and scientific research.

Dual Targeting of Sorafenib-Resistant HCC-Derived Cancer Stem Cells

Sorafenib, an oral multi-tyrosine kinase inhibitor, has been the first-line therapy for the treatment of patients with advanced HCC, providing a survival benefit of only three months in approximately 30% of patients. Cancer stem cells (CSCs) are a rare tumour subpopulation with self-renewal and differentiation capabilities, and have been implicated in tumour growth, recurrence and drug resistance. The process of epithelial-to-mesenchymal transition (EMT) contributes to the generation and maintenance of the CSC population, resulting in immune evasion and therapy resistance in several cancers, including HCC. The aim of this study is to target the chemoresistant CSC population in HCC by assessing the effectiveness of a combination treatment approach with Sorafenib, an EMT inhibitor and an immune checkpoint inhibitor (ICI). A stem-cell-conditioned serum-free medium was utilised to enrich the CSC population from the human HCC cell lines Hep3B, PLC/PRF/5 and HepG2. The anchorage independent spheres were characterised for CSC features. The human HCC-derived spheres were assessed for EMT status and expression of immune checkpoint molecules. The effect of combination treatment with SB431542, an EMT inhibitor, and siRNA-mediated knockdown of programmed cell death protein ligand-1 (PD-L1) or CD73 along with Sorafenib on human HCC-derived CSCs was examined with cell viability and apoptosis assays. The three-dimensional spheres enriched from human HCC cell lines demonstrated CSC-like features. The human HCC-derived CSCs also exhibited the EMT phenotype along with the upregulation of immune checkpoint molecules. The combined treatment with SB431542 and siRNA-mediated PD-L1 or CD73 knockdown effectively enhanced the cytotoxicity of Sorafenib against the CSC population compared to Sorafenib alone, as evidenced by the reduced size and proliferation of spheres. Furthermore, the combination treatment of Sorafenib with SB431542 and PD-L1 or CD73 siRNA resulted in an increased proportion of an apoptotic population, as evidenced by flow cytometry analysis. In conclusion, the combined targeting of EMT and immune checkpoint molecules with Sorafenib can effectively target the CSC tumour subpopulation.

LncRNA HOTAIR contributes Taxol-resistance of hepatocellular carcinoma cells via activating AKT phosphorylation by down-regulating miR-34a

Drug resistance of Taxol leads to the treatment failure in hepatocellular carcinoma (HCC). LncRNA HOTAIR have drawn increasing attention in various diseases; its function and mechanism in Taxol-resistance in HCC remain unclear. In the present study, the two Taxol resistant HCC cell lines (HepG2/Taxol and SMMC7721/Taxol) were induced. The qRT-PCR data exhibited that over-expressed HOTAIR as well as low-expressed miR-34a were founded in HepG2/Taxol and SMMC7721/Taxol cells. HOTAIR knockdown suppresses proliferation, invasion and promotes apoptosis of in HepG2/Taxol and SMMC7721/Taxol cells through up-regulating miR-34a by MTT assay, transwell invasion assays and flow cytometry, while down-regulation of miR-34a had an opposite effect on reversing Taxol resistance. Cleaved caspase-3 and Bax were significantly up-regulated by si-HOTAIR transfection, while Bcl-2 level exhibited opposite trend. Besides, HOTAIR knockdown impaired Taxol-resistance in HCC by accommodating Akt phosphorylation and Wnt/β-catenin signaling via interacting with miR-34a. The present study may afford a valuable target for treating Taxol-resistance in HCC.

Role of Alpha-Fetoprotein in Hepatocellular Carcinoma Drug Resistance

Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and a major cause of cancer-related deaths worldwide because of its high recurrence rate and poor prognosis. Surgical resection is currently the major treatment measure for patients in the early and middle stages of the disease. Because due to late diagnosis, most patients already miss the opportunity for surgery upon disease confirmation, conservative chemotherapy (drug treatment) remains an important method of comprehensive treatment for patients with middle- and late-stage liver cancer. However, multidrug resistance (MDR) in patients with HCC severely reduces the treatment effect and is an important obstacle to chemotherapeutic success. Alpha-fetoprotein (AFP) is an important biomarker for the diagnosis of HCC. The serum expression levels of AFP in many patients with HCC are increased, and a persistently increased AFP level is a risk factor for HCC progression. Many studies have indicated that AFP functions as an immune suppressor, and AFP can promote malignant transformation during HCC development and might be involved in the process of MDR in patients with liver cancer. This review describes drug resistance mechanisms during HCC drug treatment and reviews the relationship between the mechanism of AFP in HCC development and progression and HCC drug resistance.

NRBP2 Functions as a Tumor Suppressor and Inhibits Epithelial-to-Mesenchymal Transition in Breast Cancer

Nuclear Receptor Binding Protein 2 (NRBP2), one of the pseudokinases discovered during a screen of neural differentiation genes, inhibits tumor progression in medulloblastoma and hepatocellular carcinoma. However, the role and the mechanism of NRBP2 in the regulation of the progression of breast cancer (BC) have not been reported. In our study, NRBP2 was downregulated in human BC tissues compared with the corresponding normal tissues. Moreover, bioinformatics and cellular experiments illustrated that a lower level of NRBP2 contributed to a poor prognosis for patients with BC. In addition, we characterized the NRBP2-overexpressing BC cells and found that NRBP2 overexpression dramatically suppressed cell proliferation and invasion and inhibited the epithelial-mesenchymal transition (EMT) in cells in vitro, whereas knockdown of NRBP2 reversed these effects. Furthermore, overexpression of NRBP2 in the orthotopic breast tumor model significantly reduced lung metastatic nodules in nude mice. Mechanistically, NRBP2 regulated the activation of the 5′-adenosine monophosphate (AMP)-activated protein kinase/ mammalian target of rapamycin (AMPK/mTOR) signaling pathway. Moreover, the inhibition of cell proliferation, invasion and the EMT by NRBP2 overexpression was partially rescued after treatment with an AMPK inhibitor. Conversely, mTOR-specific inhibitors eliminated the effects of NRBP2 knockdown on increasing cell proliferation, invasion and the EMT, which suggested the anti-tumor effect of NRBP2, which may be partially related to the regulation of the AMPK/mTOR pathway. Taken together, NRBP2, a novel and effective prognostic indicator, inhibited the progression of BC and may become a potential therapeutic target for BC.

Nuclear Receptor Binding Protein 2 Is Downregulated in Medulloblastoma, and Reduces Tumor Cell Survival upon Overexpression

Pseudokinases, comprising 10% of the human kinome, are emerging as regulators of canonical kinases and their functions are starting to be defined. We previously identified the pseudokinase Nuclear Receptor Binding Protein 2 (NRBP2) in a screen for genes regulated during neural differentiation. During mouse brain development, NRBP2 is expressed in the cerebellum, and in the adult brain, mainly confined to specific neuronal populations. To study the role of NRBP2 in brain tumors, we stained a brain tumor tissue array for NRPB2, and find its expression to be low, or absent, in a majority of the tumors. This includes medulloblastoma (MB), a pediatric tumor of the cerebellum. Using database mining of published MB data sets, we also find that NRBP2 is expressed at a lower level in MB than in the normal cerebellum. Recent studies indicate that MB exhibits frequent epigenetic alternations and we therefore treated MB cell lines with drugs inhibiting DNA methylation or histone deacetylation, which leads to an upregulation of NRBP2 mRNA expression, showing that it is under epigenetic regulation in cultured MB cells. Furthermore, forced overexpression of NRBP2 in MB cell lines causes a dramatic decrease in cell numbers, increased cell death, impaired cell migration and inhibited cell invasion in vitro. Taken together, our data indicate that downregulation of NRBP2 may be a feature by which MB cells escape growth regulation.

Cancer stemness in hepatocellular carcinoma: mechanisms and translational potential

Cancer stemness, referring to the stem-cell-like phenotype of cancer cells, has been recognised to play important roles in different aspects of hepatocarcinogenesis. A number of well-established cell-surface markers already exist for liver cancer stem cells, with potential new markers of liver cancer stem cells being identified. Both genetic and epigenetic factors that affect various signalling pathways are known to contribute to cancer stemness. In addition, the tumour microenvironment—both physical and cellular—is known to play an important role in regulating cancer stemness, and the potential interaction between cancer stem cells and their microenvironment has provided insight into the regulation of the tumour-initiating ability as well as the cellular plasticity of liver CSCs. Potential specific therapeutic targeting of liver cancer stemness is also discussed. With increased knowledge, effective druggable targets might be identified, with the aim of improving treatment outcome by reducing chemoresistance.

Cyclovirobuxine D Exerts Anticancer Effects by Suppressing the EGFR-FAK-AKT/ERK1/2-Slug Signaling Pathway in Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), the sixth most common malignancy worldwide, is characterized by a dismal prognosis due to high recurrence and metastasis rates. Thus, the need for the development of novel chemotherapeutic drugs is urgent. Cyclovirobuxine D (CVB-D), a steroidal alkaloid extracted from Buxus microphylla that has been extensively used to relieve the symptoms of cardiovascular diseases, has shown promising antineoplastic effects in recent studies. However, the therapeutic effects and underlying mechanisms of CVB-D on HCC remain largely unelucidated. This study experimentally indicated that CVB-D can repress HCC cell proliferation by arresting the cell cycle in G2 phase and can facilitate apoptosis. In addition, the migratory and invasive capabilities of HCC cells were noticeably attenuated by a nonlethal dose of CVB-D, and this attenuation was correlated with the inhibition of epithelial-mesenchymal transition (EMT). Moreover, in vivo, CVB-D displayed excellent anticancer effects in HCC tumor-bearing nude mice. Regarding the molecular mechanisms of CVB-D activity, decreased Slug expression was determined to be associated with the aforementioned anti-HCC functions of this extract, which might be regulated by epidermal growth factor receptor (EGFR) through the focal adhesion kinase (FAK)-associated PI3K/AKT and MEK/ERK1/2 signaling pathways. Collectively, our results revealed the suppressive effects of CVB-D on progressive behaviors of HCC, including proliferation, migration, invasion, and EMT, in addition to its outstanding proapoptotic effects, which were correlated with the inhibition of the EGFR-FAK-AKT/ERK1/2-Slug signaling pathway. These discoveries provide an experimental and theoretical foundation for the use of CVB-D as a promising candidate for HCC therapy.

IL1R2 Blockade Suppresses Breast Tumorigenesis and Progression by Impairing USP15-Dependent BMI1 Stability

Breast tumor initiating cells (BTICs) with ALDH+CD24-CD44+ phenotype are the most tumorigenic and invasive cell population in breast cancer. However, the molecular mechanisms are still unclear. Here, it is found that a negative immune regulator interleukin-1 receptor type 2 (IL1R2) is upregulated in breast cancer (BC) tissues and especially in BTICs. BC patients with high IL1R2 expression have a poorer overall survival and relapse-free survival. High IL1R2 promotes BTIC self-renewal and BC cell proliferation and invasion. Mechanistically, IL1R2 is activated by IL1β, as demonstrated by the fact that IL1β induces the release of IL1R2 intracellular domain (icd-IL1R2) and icd-IL1R2 then interacts with the deubiquitinase USP15 at the UBL2 domain and promotes its activity, which finally induces BMI1 deubiquitination at lysine 81 and stabilizes BMI1 protein. In addition, IL1R2 neutralizing antibody can suppress the protein expression of both IL1R2 and BMI1, and significantly abrogates the promoting effect of IL1R2 on BTIC self-renewal and BC cell growth both in vitro and in vivo. The current results indicate that blocking IL1R2 with neutralizing antibody provides a therapeutic approach to inhibit BC progression by targeting BTICs.

The MAP3K7-mTOR Axis Promotes the Proliferation and Malignancy of Hepatocellular Carcinoma Cells

Targeted therapy is currently limited for patients with hepatocellular carcinoma (HCC) due to the lack of suitable targets. Kinases play pivotal roles in many cellular biological processes, whereas dysregulation of kinases may lead to various diseases, particularly cancer. However, the role of kinases in HCC malignancy remains unclear. In this study, we employed a kinome small interfering RNA (siRNA) library, comprising 710 kinase-related genes, to screen whether any kinases were essential for cell proliferation in various HCC cell lines. Through a kinome siRNA library screening, we found that MAP3K7 was a crucial gene for HCC cell proliferation. Pharmacological or genetic ablation of MAP3K7 diminished the growth, migration, and invasion of HCC cells, including primary HCC cells. Stable knockdown of MAP3K7 attenuated tumor formation in a spheroid cell culture model and tumor xenograft mouse model. In addition, silencing MAP3K7 reduced the phosphorylation and expression of mammalian target of rapamycin (mTOR) in HCC cells. MAP3K7 expression was positively correlated with mTOR expression in tumors of patients with HCC. Higher co-expression of MAP3K7 and mTOR was significantly associated with poor prognosis of HCC. Taken together, our results revealed that the MAP3K7-mTOR axis might promote tumorigenesis and malignancy, which provides a potential marker or therapeutic target for HCC patients.

The altered expression of autophagy-related genes participates in heart failure: NRBP2 and CALCOCO2 are associated with left ventricular dysfunction parameters in human dilated cardiomyopathy

This study aimed to analyze changes in the expression of autophagy- and phagocytosis-related genes in patients with dilated cardiomyopathy (DCM), especially in relation to left ventricular (LV) dysfunction. Furthermore, transmission electron microscopy of the diseased tissue was carried out to investigate if the gene expression changes are translated into ultrastructural alterations. LV tissue samples from patients with DCM (n = 13) and from controls (CNT; n = 10) were analyzed by RNA-sequencing, whereupon the altered expression (P < 0.05) of 13 autophagy- and 3 phagocytosis-related genes was observed. The expression changes of the autophagy-related genes NRBP2 and CALCOCO2 were associated with cardiac dysfunction and remodeling (P < 0.05). The affected patients had a higher activity of these degradation processes, as evidenced by the greater number of autophagic structures in the DCM tissue (P < 0.001). Differences in the ultrastructural distribution were also found between the DCM and CNT tissues. These results show that in patients with DCM, the altered expression of NRBP2 and CALCOCO2 is related to LV dysfunction and remodeling. Clarification of the molecular mechanisms of cardiac autophagy would help in the future development of therapies to improve LV performance.

High Expression of ANXA2 Pseudogene ANXA2P2 Promotes an Aggressive Phenotype in Hepatocellular Carcinoma

Objective

Accumulating evidence suggests that pseudogenes play potential roles in the regulation of their cognate wild-type genes, oncogenes, and tumor suppressor genes. ANXA2P2 (annexin A2 pseudogene 2) is one of three pseudogenes of annexin A2 that have recently been shown to be aberrantly transcribed in hepatocellular carcinoma (HCC) cells. However, its clinical meaning and biological function in HCC have remained unclear. Therefore, the present study was aimed at exploring the prognostic value of a high expression of ANXA2P2 in HCC tissue and at identifying whether it can affect the efficacy of targeted drugs (sorafenib, regorafenib, and lenvatinib).

Methods

We obtained ANXA2P2 mRNA expression levels from The Cancer Genome Atlas (TCGA) RNA sequence database. The expression levels of ANXA2P2 in 49 pairs of intratumoral and peritumoral liver tissues were examined by RT-PCR. Wound healing and transwell assays were performed to confirm the tumor-promoting properties of ANXA2P2 in HCC cells. CCK8 assay was conducted to identify whether ANXA2P2 can affect the growth of HCC cells when administered with targeted drugs (sorafenib, regorafenib, and lenvatinib).

Results

The expression of ANXA2P2 in HCC tissues was significantly higher than that in adjacent cancerous tissues from TCGA database and validation group. Additionally, patients with high ANXA2P2 expression in HCC tissue had a shorter overall survival, whereas no statistically significant correlation was found between ANXA2P2 expression and disease-free survival (p = 0.08) as well as other clinical parameters, such as age, gender, histological grade, T classification, stage, albumin level, alpha-fetoprotein, and vascular invasion (p = 0.7323, 0.8807, 0.5762, 0.8515, 0.7113, 0.242, 1.0000, and 0.7685, respectively). Furthermore, in vitro experiments showed that knockdown of ANXA2P2 inhibited migration and invasion of HCC cells but did not have an influence on the HCC cell proliferation when treated with targeted drugs (sorafenib, regorafenib, and lenvatinib).

Conclusion

Our study confirmed elevated ANXA2P2 expression levels in HCC tissue compared with adjacent noncancerous tissue and a worse prognosis of patients with high ANXA2P2 levels in the HCC tissue. The newly found properties of promoting migration and invasion of ANXA2P2 in HCC help to explain this phenomenon. ANXA2P2 could be a novel and suitable predicative biomarker for the risk assessment of recurrence or metastasis of HCC patients but may not be effective to predict the efficacy of targeted drugs.

RACK1 Promotes Self-Renewal and Chemoresistance of Cancer Stem Cells in Human Hepatocellular Carcinoma through Stabilizing Nanog

Targeting cancer stem cells (CSCs) has been proposed as a new strategy to eradicate malignancies, including hepatocellular carcinoma (HCC). However, the mechanisms by which CSCs sustain their self-renewal and chemoresistance remain elusive. Nanog is a master transcriptional regulator of stemness, especially in CSCs. Its expression is tightly regulated by the ubiquitin-proteasome system in embryonic stem cells (ESCs). Whether the suppression of Nanog ubiquitination contributes to its over-expression in CSCs has not been explored. In addition, the role of receptor for activated C kinase 1 (RACK1), an adaptor protein implicated in HCC growth, in liver CSC-like traits remains to be determined.

Methods: In vitro and in vivo assays were performed to investigate the role of RACK1 in liver CSC-like phenotype and murine ESC function. How RACK1 regulates Nanog expression was explored by immunoblotting and immunohistochemistry. The interaction of RACK1 with Nanog and the consequent effects on Nanog ubiquitination and stemness were then analyzed.

Results: RACK1 promotes self-renewal and chemoresistance of human liver CSCs and maintains murine ESC function. Consistently, RACK1 enhances the expression of Nanog in human HCC cells and murine ESCs. The protein levels of RACK1 in clinical HCC tissues positively correlate with those of Nanog. Further exploration indicates that RACK1 directly binds to Nanog, which prevents its recruitment of E3 ubiquitin ligase FBXW8 and ubiquitin-dependent degradation. The interaction with Nanog is essential for RACK1 to promote stemness.

Conclusions: Our data provide novel insights into the regulation of Nanog protein levels, as well the key role of RACK1 to enhance self-renewal and chemoresistance of CSCs in human HCC.

Dauricine upregulates the chemosensitivity of hepatocellular carcinoma cells: Role of repressing glycolysis via miR-199a:HK2/PKM2 modulation

Dauricine (Dau) is a natural alkaloid exhibiting anti-proliferative activity against several different types of malignant cell. However, effects of Dau on hepatocellular carcinoma (HCC) cells and the underlying molecular mechanisms have remained to be fully elucidated. In this study, we found that Dau elevated the sensitivities of HCC cells to chemotherapeutic reagents, including cisplatin, sorafenib, and isoliensinine. Moreover, Dau promoted apoptosis of HCC cells triggered by these chemotherapeutic reagents. Consistently, in a xenograft mouse model, Dau sensitized HCC cells to sorafenib. In HCC cells, Dau dose-dependently inhibited glucose glycolysis and increased oxidative phosphorylation. Mechanistically, Dau downregulated the expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). HK2 and PKM2 can be directly targeted by miR-199a. Dau dose-dependently increased miR-199a expression in HCC cells. Transfection of anti-miR-199a abrogated Dau-mediated suppression of HK2 and PKM2. Dau-induced metabolic shift was thereby severely crippled by anti-miR-199a. In addition, the incremental activity of Dau on sorafenib sensitivity of HCC cells was diminished in response to the transfection of anti-miR-199a. Taken together, our findings provided novel insights into the impact of Dau on HCC cells and supported considering Dau as an adjuvant reagent in the clinical treatment of HCC.

MicroRNA-760 Inhibits Doxorubicin Resistance in Hepatocellular Carcinoma through Regulating Notch1/Hes1-PTEN/Akt Signaling Pathway

Accumulating studies have suggested that microRNA-760 (miR-760) plays an important role in chemoresistance of various cancer cells. However, whether miR-760 regulates the chemoresistance of hepatocellular carcinoma (HCC) remains unclear. In this study, we found that miR-760 was decreased in HCC cell lines, and doxorubicin (Dox) treatment significantly decreased miR-760 expression in HCC cells. Overexpression of miR-760 sensitized HCC cells to Dox-induced cytotoxicity and apoptosis, whereas miR-760 inhibition showed the opposite effects. Notch1 was predicted as a target gene of miR-760. miR-760 negatively regulated Notch1 expression and Notch1/Hes1 signaling. Overexpression of miR-760 increased PTEN expression and decreased the phosphorylation of Akt. Activation of Notch signaling significantly reversed the inhibitory effect of miR-760 on Dox-resistance and abrogated the effect of miR-760 on the PTEN/Akt signaling pathway in HCC cells. Overall, our results demonstrate that miR-760 inhibits Dox-resistance in HCC cells through inhibiting Notch1 and promoting PTEN expression.

Anticancer effects of isofraxidin against A549 human lung cancer cells via the EGFR signaling pathway

Lung cancer is the leading cause of mortality due to tumor malignancy worldwide. In recent years, the treatment of lung cancer with chemotherapy has demonstrated notable resistance and insensitivity. Therefore, it is of great importance to investigate anti‑lung cancer drugs with high efficiency and low toxicity. In the present study, the effects of isofraxidin on lung cancer cells and the associated mechanisms were investigated. The results revealed that, in vivo and in vitro, isofraxidin exhibited marked inhibitory effects on the A549 lung cancer cell line. The results of Cell Counting kit‑8, Transwell migration and Matrigel invasion assays, and flow cytometry to determine apoptosis, revealed that isofraxidin significantly inhibited the proliferation, migration and invasion of A549 cells, and induced the cell apoptosis. Furthermore, western blot analysis demonstrated that isofraxidin treatment led to effects on the expression of apoptosis‑associated proteins, including members of the Bcl‑2 protein family, and invasion‑associated proteins, including matrix metallopeptidase (MMP)‑2 and MMP‑9, which may occur via inhibition of the expression of phosphorylated (p)‑epidermal growth factor receptor, p‑AKT and p‑extracellular signal‑regulated kinase. This regulation of protein expression may contribute to the inhibition of proliferation, migration and invasion of A549lung cancer cells by isofraxidin. In addition, despite the inhibitory effects on the A549 lung cancer cell line, the present study revealed that isofraxidin exhibited low toxicity towards BEAS‑2B normal lung epithelial cells within a certain dose range (0‑160 µM), indicating that isofraxidin may be employed for lung cancer treatment with hypotoxicity and fewer side effects. In conclusion, isofraxidin may be a novel candidate for anti‑lung cancer chemotherapy.

NRBP2 Overexpression Inhibits Cell Proliferation and Migration and Increases Cisplatin Sensitivity in Intrahepatic Cholangiocarcinoma

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New insights into sorafenib resistance in hepatocellular carcinoma: Responsible mechanisms and promising strategies

It is disappointing that only a few patients with hepatocellular carcinoma (HCC) obtain a significant survival benefit from the sorafenib treatment, which is currently regarded as a first-line chemotherapeutic therapy in patients with advanced HCC. Most patients are highly refractory to this therapy. Therefore, it is necessary to identify resistant factors and explore potential protocols that can be used to overcome the resistance or substitute sorafenib once the resistance is formed. In fact, a growing body of studies has been focusing on the resistance mechanisms or the method to overcome it. The limitation of sorafenib efficacy has been partially but not fully elucidated. Moreover, some protocols have shown encouraging outcomes but still need to be further verified in clinical trials. In this review, we summarize the recent findings on the potential mechanisms that contribute to sorafenib resistance and discuss strategies that can be used to improve the treatment outcome.

The secret life of kinases: insights into non-catalytic signalling functions from pseudokinases

Over the past decade, our understanding of the mechanisms by which pseudokinases, which comprise ∼10% of the human and mouse kinomes, mediate signal transduction has advanced rapidly with increasing structural, biochemical, cellular and genetic studies. Pseudokinases are the catalytically defective counterparts of conventional, active protein kinases and have been attributed functions as protein interaction domains acting variously as allosteric modulators of conventional protein kinases and other enzymes, as regulators of protein trafficking or localisation, as hubs to nucleate assembly of signalling complexes, and as transmembrane effectors of such functions. Here, by categorising mammalian pseudokinases based on their known functions, we illustrate the mechanistic diversity among these proteins, which can be viewed as a window into understanding the non-catalytic functions that can be exerted by conventional protein kinases.

Growth differentiation factor 15 induces growth and metastasis of human liver cancer stem-like cells via AKT/GSK-3β/β-catenin signaling

Cancer stem cells in liver cancer are thought to be responsible for tumor recurrence and metastasis. However, the factors that mediate this mechanism have yet to be completely elucidated. In this study, we isolated CD13⁺CD44⁺ sphere cells (SCs) derived from liver cancer tissues and SK-Hep-1 cells, which possessed cancer stem cell-like properties. Through cytokine array analysis, growth differentiation factor 15 (GDF15) was significantly increased in SCs. Clinical data showed GDF15 was overexpressed in liver cancer tissues and was positively related to pathological grading. GDF15 knockdown significantly inhibited the growth and metastasis of SCs through AKT/GSK-3β/β-catenin pathway suppression. Moreover, a PI3K inhibitor LY294002 inhibited AKT/GSK-3β/β-catenin pathway activated by GDF15 and attenuated GDF15-induced proliferation, colony formation and invasion of SCs. Conclusion: Our studies suggest that CD13⁺CD44⁺ SCs may represent a subset of LCSCs. GDF15 promotes the growth and metastasis of SCs by activating AKT/GSK-3β/β-catenin signaling pathway. Promisingly, GDF15 could be considered as a potential therapeutic target in liver cancer.

Chemotherapy for hepatocellular carcinoma: The present and the future

Hepatocellular carcinoma (HCC) is the most common primary tumor of the liver. Its relationship to chronic liver diseases, in particular cirrhosis, develops on a background of viral hepatitis, excessive alcohol intake or metabolic steatohepatitis, leads to a high incidence and prevalence of this neoplasia worldwide. Despite the spread of HCC, its treatment it’s still a hard challenge, due to high rate of late diagnosis and to lack of therapeutic options for advanced disease. In fact radical surgery and liver transplantation, the most radical therapeutic approaches, are indicated only in case of early diagnosis. Even local therapies, such as transarterial chemoembolization, find limited indications, leading to an important problem regarding treatment of advanced disease. In this situation, until terminal HCC occurs, systemic therapy is the only possible approach, with sorafenib as the only standard treatment available. Anyway, the efficacy of this drug is limited and many efforts are necessary to understand who could benefit more with this treatment. Therefore, other molecules for a targeted therapy were evaluated, but only regorafenib showed promising results. Beside molecular target therapy, also cytotoxic drugs, in particular oxaliplatin- and gemcitabine-based regimens, and immune-checkpoint inhibitors were tested with interesting results. The future of the treatment of this neoplasia is linked to our ability to understand its mechanisms of resistance and to find novel therapeutic targets, with the objective to purpose individualized approaches to patients affected by advanced HCC.

Azelaic Acid Exerts Antileukemic Activity in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an acute leukemia common in most adults; its prevalence intensifies with age. The overall survival of AML is very poor because of therapeutic resistance. Azelaic acid (AZA) is non-toxic, non-teratogenic, and non-mutagenic and its antitumor effect on various tumor cells is well established; Nonetheless, its therapeutic effects in AML cells are largely unknown. In this study, it was shown that AZA significantly inhibits the cell viability and induces apoptosis in AML cells in a dose-dependent manner. Additionally, AZA suppressed the expression of phosphorylated Akt, Jab1 and Trx, and this suppression was enhanced by treatment with Jab1 siRNA. Furthermore, AZA sensitized AML cells to Ara-c chemotherapy. The suppressive effect of AZA on tumor growth was examined in vivo by subcutaneously inoculated AML cells in a tumor model using nude mice. These findings indicate that AZA is useful as an effective ingredient in antineoplastic activity.

Clinicopathological characteristics and prognostic value of cancer stem cell marker CD133 in breast cancer: a meta-analysis

Background

The association of CD133 overexpression with clinicopathological significance and prognosis in patients with breast cancer remains controversial. We thus performed a meta-analysis to evaluate the role of CD133 expression in the development and prognosis of breast cancer.

Methods

The databases PubMed, Embase, and Cochrane Library (updated to August 1, 2016) were searched. Pooled odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to evaluate the impact of CD133 expression on clinicopathological features, overall survival, and disease-free survival.

Results

A total of 1,734 patients from 13 studies were subject to final analysis. The results showed a significant association between overexpression of CD133 and estrogen receptor status (OR 0.35, 95% CI 0.18–0.70), progesterone receptor status (OR 0.56, 95% CI 0.43–0.74), human epidermal growth factor-2 status (OR 1.81, 95% CI 1.33–2.45), lymph node metastasis (OR 1.98, 95% CI 1.34–2.92), and tumor histological grade (OR 1.79, 95% CI 1.26–2.54) in breast cancer. However, no significant correlation was found between upregulation of CD133 expression and onset age (OR 1.03, 95% CI 0.70–1.53) or tumor size (OR 1.29, 95% CI 0.80–2.09). Moreover, CD133-positive breast cancer patients had a higher risk of mortality (HR 1.91, 95% CI 1.21–3.03) and disease progression (HR 2.70, 95% CI 1.05–6.95).

Conclusion

This meta-analysis suggested that CD133 might be a predictor of clinical outcomes as well as prognosis and could be a potentially new gene therapy target for breast cancer patients.