CXCR4 promotes GSK3β expression in pancreatic cancer cells via the Akt pathway

Stem cell-like circulating tumor cells identified by Pep@MNP and their clinical significance in pancreatic cancer metastasis

Objective

The circulating tumor cells (CTCs) could be captured by the peptide functionalized magnetic nanoparticles (Pep@MNP) detection system in pancreatic ductal adenocarcinoma (PDAC). CTCs and the CXCR4 expression were detected to explore their clinical significance. The CXCR4+ CTCs, this is highly metastatic-prone stem cell-like subsets of CTCs (HM-CTCs), were found to be associated with the early recurrence and metastasis of PDAC.

Methods

CTCs were captured by Pep@MNP. CTCs were identified via immunofluorescence with CD45, cytokeratin antibodies, and the CXCR4 positive CTCs were assigned to be HM-CTCs.

Results

The over-expression of CXCR4 could promote the migration of pancreatic cancer cell in vitro and in vivo. In peripheral blood (PB), CTCs were detected positive in 79.0% of all patients (49/62, 9 (0-71)/2mL), among which 63.3% patients (31/49, 3 (0-23)/2mL) were HM-CTCs positive. In portal vein blood (PVB), CTCs were positive in 77.5% of patients (31/40, 10 (0-40)/2mL), and 67.7% of which (21/31, 4 (0-15)/2mL) were HM-CTCs positive CTCs enumeration could be used as diagnostic biomarker of pancreatic cancer (AUC = 0.862), and the combination of CTCs positive and CA19-9 increase shows improved diagnostic accuracy (AUC = 0.963). in addition, PVB HM-CTCs were more accurate to predict the early recurrence and liver metastasis than PB HM-CTCs (AUC 0.825 vs. 0.787 and 0.827 vs. 0.809, respectively).

Conclusions

The CTCs identified by Pep@MNP detection system could be used as diagnostic and prognostic biomarkers of PDAC patients. We identified and defined the CXCR4 over-expressed CTC subpopulation as highly metastatic-prone CTCs, which was proved to identify patients who were prone to suffering from early recurrence and metastasis.

Glycogen synthase kinase 3β: the nexus of chemoresistance, invasive capacity, and cancer stemness in pancreatic cancer

The treatment of pancreatic cancer remains a significant clinical challenge due to the limited number of patients eligible for curative (R0) surgery, failures in the clinical development of targeted and immune therapies, and the pervasive acquisition of chemotherapeutic resistance. Refractory pancreatic cancer is typified by high invasiveness and resistance to therapy, with both attributes related to tumor cell stemness. These malignant characteristics mutually enhance each other, leading to rapid cancer progression. Over the past two decades, numerous studies have produced evidence of the pivotal role of glycogen synthase kinase (GSK)3β in the progression of over 25 different cancer types, including pancreatic cancer. In this review, we synthesize the current knowledge on the pathological roles of aberrant GSK3β in supporting tumor cell proliferation and invasion, as well as its contribution to gemcitabine resistance in pancreatic cancer. Importantly, we discuss the central role of GSK3β as a molecular hub that mechanistically connects chemoresistance, tumor cell invasion, and stemness in pancreatic cancer. We also discuss the involvement of GSK3β in the formation of desmoplastic tumor stroma and in promoting anti-cancer immune evasion, both of which constitute major obstacles to successful cancer treatment. Overall, GSK3β has characteristics of a promising therapeutic target to overcome chemoresistance in pancreatic cancer.

DEL-1 suppression attenuates atherosclerosis by modulating macrophagic GSK-3β/CEBP-β signaling pathway

OBJECTIVE

The study aims to investigate the effect of developmental endothelial locus-1(DEL-1) expression in atherosclerotic plaque formation and its mechanism.

METHODS

Human left coronary arteries were collected to detect the DEL-1 expression. The ApoE-/- mice were used to establish the atherosclerosis mice model. The left coronary artery and mouse aorta were stained with HE, Oil Red O, and Movat staining. The DEL-1 levels, chemokines CXC chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor-1alpha (SDF-1α), pathway protein glycogen synthase kinase-3β (GSK-3β), CCAAT enhanced binding protein β (C/EBPβ), and downstream inflammatory factors (C-X-C motif chemokine 2 (MIP-2or CXCL2), macrophage inflammatory protein-1alpha (MIP-1α or CCL3),Tumor Necrosis Factor alpha (TNF-α) were detected by immunoblotting and immunohistochemistry. Pearson correlation coefficient was used to analyze the correlation between DEL-1 gene expression and inflammatory factors in the lesion group and the correlation between DEL-1 gene expression and structure-related indexes.

RESULTS

Compared with Control group(CON), the intravascular plaque area was widened, accompanied by narrowed lumens. The number of plaque foam cells was significantly increased in the high fat and high cholesterol (AS group) or AAV9-eGFP group (P < 0.05). Compared to CON, the enhanced fluorescence intensity of DEL-1 with CD68 in the AS or AAV9-eGFP groups. Diminished fluorescence of DEL-1 with CD68 expression in AAV9-CXCR4 group compared to AS group or AAV9-eGFP group. The DEL-1 and its downstream proteins in AS group or AAV9-eGFP group were mainly accumulated in the macrophage cytoplasm. The DEL-1 expression level was significantly and positively correlated with plaque area, lumen stenosis, plaque foam cell count, TNFα, CXCL2, and CCL3 levels.

CONCLUSION

DEL-1 inhibition decreases macrophagic inflammatory factors involved in atherosclerotic plaque formation.

The upregulation of stromal antigen 3 expression suppresses the phenotypic hallmarks of hepatocellular carcinoma through the Smad3-CDK4/CDK6-cyclin D1 and CXCR4/RhoA pathways

BACKGROUND

The stromal antigen 3 (STAG3) gene encodes an adhesion complex subunit that can regulate sister chromatid cohesion during cell division. Chromosome instability caused by STAG3 gene mutation may potentially promote tumor progression, but the effect of STAG3 on hepatocellular carcinoma (HCC) and the related molecular mechanism are not reported in the literature. The mechanism of the occurrence and development of HCC is not adequately understood. Therefore, the biological role of STAG3 in HCC remains to be studied, and whether STAG3 might be a sensitive therapeutic target in HCC remains to be determined.

METHODS

The expression and clinical significance of STAG3 in HCC tissues and cell lines were determined by RT-qPCR and immunohistochemistry analyses. The biological functions of STAG3 in HCC were determined through in vitro and in vivo cell function tests. The molecular mechanism of STAG3 in HCC cells was then investigated by western blot assay.

RESULTS

The mRNA expression of STAG3 was lower in most HCC cells than in normal cells. Subsequently, an immunohistochemical analysis of STAG3 was performed with 126 samples, and lower STAG3 expression was associated with worse overall survival in HCC patients. Moreover, cytofunctional tests revealed that the lentivirus-mediated overexpression of STAG3 in HCC cells inhibited cell proliferation, migration, and invasion; promoted apoptosis; induced G1/S phase arrest in vitro; and inhibited tumor growth in vivo. Furthermore, studies of the molecular mechanism suggested that the overexpression of STAG3 increased Smad3 expression and decreased CDK4, CDK6, cyclin D1, CXCR4 and RhoA expression.

CONCLUSION

STAG3 exhibits anticancer effects against HCC, and these effects involve the Smad3-CDK4/CDK6-cyclin D1 and CXCR4/RhoA pathways. STAG3 is a tumor-suppressor gene that may serve as a potential target for molecular therapy, which provides a new idea for the treatment of HCC.

Glycogen Synthase Kinase 3β in Cancer Biology and Treatment

Glycogen synthase kinase (GSK)3β is a multifunctional serine/threonine protein kinase with more than 100 substrates and interacting molecules. GSK3β is normally active in cells and negative regulation of GSK3β activity via phosphorylation of its serine 9 residue is required for most normal cells to maintain homeostasis. Aberrant expression and activity of GSK3β contributes to the pathogenesis and progression of common recalcitrant diseases such as glucose intolerance, neurodegenerative disorders and cancer. Despite recognized roles against several proto-oncoproteins and mediators of the epithelial–mesenchymal transition, deregulated GSK3β also participates in tumor cell survival, evasion of apoptosis, proliferation and invasion, as well as sustaining cancer stemness and inducing therapy resistance. A therapeutic effect from GSK3β inhibition has been demonstrated in 25 different cancer types. Moreover, there is increasing evidence that GSK3β inhibition protects normal cells and tissues from the harmful effects associated with conventional cancer therapies. Here, we review the evidence supporting aberrant GSK3β as a hallmark property of cancer and highlight the beneficial effects of GSK3β inhibition on normal cells and tissues during cancer therapy. The biological rationale for targeting GSK3β in the treatment of cancer is also discussed at length.

Locally advanced pancreatic cancer: An emerging entity

Pancreatic adenocarcinoma (PDAC) remains a highly fatal disease that is increasing in incidence. PDAC can be classified according to resectability status with 3 nonmetastatic groups defined: resectable, borderline resectable, and locally advanced PDAC (LAPC). Delineating these subtypes is important with the optimal treatment approach dictated by high-quality CT imaging and multidisciplinary team discussion. Patients with LAPC are thought unresectable and are therefore rarely cured. In these patients, chemotherapy remains the mainstay of treatment. Aggressive approaches in this cohort are increasingly employed. Local therapies after induction chemotherapy including standard fractionation radiation, stereotactic body radiotherapy (SBRT), and irreversible electroporation (IRE) are being investigated in an attempt to improve long-term control. In some cases, responses to neoadjuvant therapy may facilitate surgical resection. Biomarkers that can select patients most likely to benefit from these options are urgently needed. This review aims to highlight the emerging treatment of patients with LAPC and to discuss current trials.

Genetic factors affecting patient responses to pancreatic cancer treatment

Cancer of the exocrine pancreas is a malignancy with a high lethal rate. Surgical resection is the only possible curative mode of treatment. Metastatic pancreatic cancer is incurable with modest results from the current treatment options. New genomic information could prove treatment efficacy. An independent review of PubMed and ScienceDirect databases was performed up to March 2016, using combinations of terms such pancreatic exocrine cancer, chemotherapy, genomic profile, pancreatic cancer pharmacogenomics, genomics, molecular pancreatic pathogenesis, and targeted therapy. Recent genetic studies have identified new markers and therapeutic targets. Our current knowledge of pancreatic cancer genetics must be further advanced to elucidate the molecular basis and pathogenesis of the disease, improve the accuracy of diagnosis, and guide tailor-made therapies.

Plumbagin induces G2/M arrest, apoptosis, and autophagy via p38 MAPK- and PI3K/Akt/mTOR-mediated pathways in human tongue squamous cell carcinoma cells

Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone; PLB), a naturally occurring naphthoquinone isolated from the roots of Plumbaginaceae plants, has been reported to possess anticancer activities in both in vitro and in vivo studies, but the effect of PLB on tongue squamous cell carcinoma (TSCC) is not fully understood. This study aimed to investigate the effects of PLB on cell cycle distribution, apoptosis, and autophagy, and the underlying mechanisms in the human TSCC cell line SCC25. The results have revealed that PLB exerted potent inducing effects on cell cycle arrest, apoptosis, and autophagy in SCC25 cells. PLB arrested SCC25 cells at the G2/M phase in a concentration- and time-dependent manner with a decrease in the expression level of cell division cycle protein 2 homolog (Cdc2) and cyclin B1 and increase in the expression level of p21 Waf1/Cip1, p27 Kip1, and p53 in SCC25 cells. PLB markedly induced apoptosis and autophagy in SCC25 cells. PLB decreased the expression of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) while increasing the expression level of the pro-apoptotic protein Bcl-2-associated X protein (Bax) in SCC25 cells. Furthermore, PLB inhibited phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), glycogen synthase kinase 3β (GSK3β), and p38 mitogen-activated protein kinase (p38 MAPK) pathways as indicated by the alteration in the ratio of phosphorylation level over total protein expression level, contributing to the autophagy inducing effect. In addition, we found that wortmannin (a PI3K inhibitor) and SB202190 (a selective inhibitor of p38 MAPK) strikingly enhanced PLB-induced autophagy in SCC25 cells, suggesting the involvement of PI3K- and p38 MAPK-mediated signaling pathways. Moreover, PLB induced intracellular reactive oxygen species (ROS) generation and this effect was attenuated by l-glutathione (GSH) and n-acetyl-l-cysteine (NAC). Taken together, these results indicate that PLB promotes cellular apoptosis and autophagy in TSCC cells involving p38 MAPK- and PI3K/Akt/mTOR-mediated pathways with contribution from the GSK3β and ROS-mediated pathways.