Screening of an annexin-A2-targeted heptapeptide for pancreatic adenocarcinoma localization.

Annexin A2 (ANXA2) encodes an oncoprotein whose expression has been found to correlate with poorer overall survival (OS) of pancreatic adenocarcinoma (PAAD) patients. Although peptides are available for targeting ANXA2, none of these were initially selected to target this protein specifically. Here, we took ANXA2 as a molecular target for PAAD and employed the phage display technique to screen for a new ANXA2-targeted peptide. The resultant heptapeptide, YW7, was firstly labeled with fluorescein isothiocyanate (FITC) to evaluate its selectivity in cellular uptake, and further with the near-infrared fluorescent (NIRF) dye Cy7 to assess in vivo distribution in a mouse model bearing PANC-1 human pancreatic cancer xenografic tumors. We found that both FITC-YW7 and Cy7-YW7 probes showed significantly higher uptake in PANC-1 cells compared to the HPDE6-C7 pancreatic epithelium cells. Mice intravenously injected with Cy7-YW7 showed higher tumor-to-background ratios (TBRs) (~ 2.7-fold) in tumor tissues compared to those injected with Cy7 alone. Our study suggested that YW7 is a novel peptide targeting ANXA2 and Cy7-YW7 is an NIRF probe potentially useful for the early detection of PAAD.

Corrigendum: SNORA72 activates the Notch1/c-Myc pathway to promote stemness transformation of ovarian cancer cells.

[This corrects the article DOI: 10.3389/fcell.2020.583087.].

SNORA72 Activates the Notch1/c-Myc Pathway to Promote Stemness Transformation of Ovarian Cancer Cells.

Cancer stem cells (CSCs) are responsible for the migration and recurrence of cancer progression. Small nucleolar RNAs (snoRNAs) play important roles in tumor development. However, how snoRNAs contribute to the regulation of the stemness of ovarian CSCs (OCSCs) remains unclear. In the present study, we found that SNORA72 was significantly upregulated in OVCAR-3 spheroids (OS) and CAOV-3 spheroids (CS) with the OCSC characteristics attained by serum-free culture in a suspension of OVCAR-3 (OV) and CAOV-3 (CA) cells. The overexpression of SNORA72 increased self-renewal abilities and migration abilities in OV and CA cells and upregulated the expressions of the stemness markers Nanog, Oct4, and CD133. In addition, the ectopic expression of SNORA72 can elevate the messenger RNA (mRNA) and protein expression levels of Notch1 and c-Myc in parental cells. The opposite results were observed in SNORA72-silenced OCSCs. Moreover, we found that Notch1 knockdown inversed the migration abilities and self-renewal abilities raised by overexpressing SNORA72. In summary, stemness transformation of ovarian cancer cells can be activated by SNORA72 through the Notch1/c-Myc pathway. This study introduces a novel therapeutic strategy for improving the treatment efficiency of ovarian cancer.

Anterior gradient 2-derived peptide upregulates major histocompatibility complex class I-related chains A/B in hepatocellular carcinoma cells.

AIMS: Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide. Decrease in NKG2D ligand levels and exhaustion of NK cells in HCC patients are major causes of immune escape, high recurrence, poor prognosis, and low overall survival. Enhancing the susceptibility of HCC to NK cells by upregulating NKG2DLs on tumor cells is an effective treatment strategy. This study aimed to identify the effect of the Anterior gradient 2 (AGR2)-derived peptide P1, which was reported to bind to HLA-A*0201 as an epitope, on both the expression of major histocompatibility complex class I-related chains A/B (MICA/B) on HCC cells and the cytotoxicity of NK cells. MAIN METHODS: The effect of P1 on MICA/B expression on HCC cells was determined by qRT-PCR, western blotting, and flow cytometry analysis. HCC cells were pre-treated with various pathway inhibitors to identify the molecular pathways associated with P1 treatment. The cytotoxicity of NK cells toward HCC was investigated by LDH cytotoxicity assay. The tumor-suppression effect of P1 was determined in vivo using a NOD/SCID mice HCC model. KEY FINDINGS: P1 significantly increased MICA/B expression on HCC cells, thereby enhancing their susceptibility to the cytotoxicity of NK cells in vitro and in vivo. Further, p38 MAPK cell signaling pathway inhibitor SB203580 significantly attenuated the effects of P1 in vivo and in vitro. SIGNIFICANCE: P1 upregulates MICA and MICB expression on HCC cells, thereby promoting their recognition and elimination by NK cells, which makes P1 an attractive novel immunotherapy agent.

Identification of a panel of mitotic spindle-related genes as a signature predicting survival in lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is one of the most malignant tumor types worldwide. Our objective was to identify a genetic signature that could predict the prognosis of patients with LUAD. We extracted gene data sets from The Cancer Genome Atlas and obtained differentially expressed genes that were highly expressed at every stage. These genes were analyzed using gene set enrichment analysis to obtain four biological processes associated with LUAD. Subsequently, Cox univariate and multivariate analyses were performed to generate four optimized models (G2M checkpoint, E2F targets, mitotic spindle, and glycolysis). We identified a mitotic spindle-related signature (KIF15, BUB1, CCNB2, CDK1, KIF4A, DLGAP5, ECT2, and ANLN), which could be an independent prognostic indicator, to predict the prognosis of patients with LUAD. This new discovery should offer opportunities to explore the pathogenesis of LUAD and prove clinically useful in predicting LUAD patient prognosis.

Identification of potential key genes and pathways predicting pathogenesis and prognosis for triple-negative breast cancer.

BACKGROUND: Triple negative breast cancer (TNBC) is a specific subtype of breast cancer with a poor prognosis due to its aggressive biological behaviour and lack of therapeutic targets. We aimed to explore some novel genes and pathways related to TNBC prognosis through bioinformatics methods as well as potential initiation and progression mechanisms. METHODS: Breast cancer mRNA data were obtained from The Cancer Genome Atlas database (TCGA). Differential expression analysis of cancer and adjacent cancer, as well as, triple negative breast cancer and non-triple negative breast cancer were performed using R software. The key genes related to the pathogenesis were identified by functional and pathway enrichment analysis and protein-protein interaction network analysis. Based on univariate and multivariate Cox proportional hazards model analyses, a gene signature was established to predict overall survival. Receiver operating characteristic curve was used to evaluate the prognostic performance of our model. RESULTS: Based on mRNA expression profiling of breast cancer patients from the TCGA database, 755 differentially expressed overlapping mRNAs were detected between TNBC/non-TNBC samples and normal tissue. We found eight hub genes associated with the cell cycle pathway highly expressed in TNBC. Additionally, a novel six-gene (TMEM252, PRB2, SMCO1, IVL, SMR3B and COL9A3) signature from the 755 differentially expressed mRNAs was constructed and significantly associated with prognosis as an independent prognostic signature. TNBC patients with high-risk scores based on the expression of the 6-mRNAs had significantly shorter survival times compared to patients with low-risk scores (P < 0.0001). CONCLUSIONS: The eight hub genes we identified might be tightly correlated with TNBC pathogenesis. The 6-mRNA signature established might act as an independent biomarker with a potentially good performance in predicting overall survival.

Chemosensitizing Effect of Saikosaponin B on B16F10 Melanoma Cells.

Cancer cell resistance to chemotherapy is one of the obstacles for better cancer treatment, and inflammatory signaling pathways, such as NF-κB signaling pathway, have been recognized to be involved in such chemoresistance. In this study, we aim to identify a new approach for overcoming cancer chemoresistance by using natural compounds. As a result of screening by using Murine B16F10 melanoma cell line constitutively expressing NF-κB luciferase reporter gene, we identified Saikosaponin B2 as an effective inhibitor for etoposide-induced NF-κB activation in B16F10NFkB cells. Saikosaponin B2 sensitized etoposide-induced cell death in B16F10 melanoma cells through the induction of apoptosis. Along with apoptosis induction, we observed an induction of γ-H2AX expression, which is a molecular signature for DNA damage, upon the combination treatment of etoposide and Saikosaponin B2. Among Saikosaponin family compounds, we found that Saikosaponin B1, but not Saikosaponin A, sensitized etoposide-induced cytotoxicity implicating the structural requirement of Saikosaponin B for such chemosensitization. By testing the combination of Saikosaponin B1 and B2 with 9 clinical anticancer drugs, Saikosaponin B showed a certain preference in the combination with those tested anticancer drugs. Collectively, we conclude Saikosaponin B can be an attractive adjuvant for enhancing the clinical effect of cancer chemotherapy.

[Research progress on targeting effect and regulating mechanisms of the stemness of cancer stem cells].

Cancer stem cells(CSCs) have become an important target to overcome the obstacle of tumor therapy. In recent years, many reports have shown that the heterogenicity and plasticity of CSCs, and the microenvironment interact with each other, which become important factors affecting the dynamic conversion of CSCs. Therefore, we should not only focus on the stem characteristics of CSCs, but also consider the factors related to the regulation of the dynamic transformation of CSCs stemness. The signaling pathways, epithelial- mesenchymal transition(EMT) and the niche of CSCs, are proved to play an important role in the regulation of stemness of CSCs. The aspects are important in the studies of tumor therapy by targeting CSCs. This article summarizes the mechanisms for regulation of the stemness of cancer stem cells and the progress in the studies of targeting cancer stem cells with a focus on the CSCs dynamic regulation.