The G4 Resolvase DHX36 Possesses a Prognosis Significance and Exerts Tumour Suppressing Function Through Multiple Causal Regulations in Non-Small Cell Lung Cancer.

Lung cancer is one of the most prevalent cancers in both men and women worldwide. The nucleic acid G4 structures have been implicated in the transcriptional programmes of cancer-related genes in some cancers such as lung cancer. However, the role of the dominant G4 resolvase DHX36 in the progression of lung cancer remains unknown. In this study, by bioinformatic analysis of public datasets (TCGA and GEO), we find DHX36 is an independent prognosis indicator in non-small-cell lung carcinoma (NSCLC) with subtype dependence. The stable lentiviral knockdown of the DHX36 results in accelerated migration and aggregation of the S-phase subpopulation in lung cancer cells. The reduction of DHX36 level de-sensitises the proliferation response of lung cancer cells to chemotherapeutic drugs such as paclitaxel with cell dependence. The knockdown of this helicase leads to promoted tumour growth, demonstrated by a 3D fluorescence spheroid lung cancer model, and the stimulation of cell colony formation as shown by single-cell cultivation. High throughput proteomic array indicates that DHX36 functions in lung cancer cells through regulating multiple signalling pathways including activation of protein activity, protein autophosphorylation, Fc-receptor signalling pathway, response to peptide hormone and stress-activated protein kinase signalling cascade. A causal transcriptomic analysis suggests that DHX36 is significantly associated with mRNA surveillance, RNA degradation, DNA replication and Myc targets. Therefore, we unveil that DHX36 presents clinical significance and plays a role in tumour suppression in lung cancer, and propose a potentially new concept for an anti-cancer therapy based on helicase-specific targeting.

Lead DEAD/H box helicase biomarkers with the therapeutic potential identified by integrated bioinformatic approaches in lung cancer.

DEAD/H box helicases are implicated in lung cancer but have not been systematically investigated for their clinical significance and function. In this study, we aimed to evaluate the potential of DEAD/H box helicases as prognostic biomarkers and therapeutic targets in lung cancer by integrated bioinformatic analysis of multivariate large-scale databases. Survival and differential expression analysis of these helicases enabled us to identify four biomarkers with the most significant alterations. These were found to be the negative prognostic factors DDX11, DDX55 and DDX56, and positive prognostic factor DDX5. Pathway enrichment analysis indicates that MYC signalling is negatively associated with expression levels of the DDX5 gene while positively associated with that of DDX11, DDX55 and DDX56. High expression levels of the DDX5 gene is associated with low mutation levels of TP53 and MUC16, the two most frequently mutated genes in lung cancer. In contrast, high expression levels of DDX11, DDX55 and DDX56 genes are associated with high levels of TP53 and MUC16 mutation. The tumour-infiltrated CD8 + T and B cells positively correlate with levels of DDX5 gene expression, while negatively correlate with that of the other three DEAD box helicases, respectively. Moreover, the DDX5-associated miRNA profile is distinguished from the miRNA profiles of DDX11, DDX55 and DDX56, although each DDX has a different miRNA signature. The identification of these four DDX helicases as biomarkers will be valuable for prognostic prediction and targeted therapeutic development in lung cancer.

Calcium-Binding Protein S100P Promotes Tumor Progression but Enhances Chemosensitivity in Breast Cancer.

BACKGROUND: Chemoresistance remains one of the obstacles to overcome in the treatment of breast cancer. S100 calcium-binding protein P (S100P) has been observed to be overexpressed in several cancers and has been associated with drug resistance, metastasis, and prognosis. However, the role of S100P in chemoresistance in breast cancer has not been thoroughly determined. METHODS: Immunohistochemistry was used to evaluate the expression level of S100P protein in 22 pairs (pre-chemo and post-chemo) of breast cancer tissue from patients who underwent neoadjuvant chemotherapy. The influence of S100P on the biological behavior and chemosensitivity of breast cancer cells was then investigated. RESULTS: The protein level of S100P in breast cancer tissue was significantly higher than in benign fibroadenoma (p < 0.001). The S100P expression level was shown to be decreased by 46.55% after neoadjuvant chemotherapy (p = 0.015). Subgroup analysis revealed that S100P reduction (57.58%) was mainly observed in the HER2+ tumors (p = 0.027). Our in vitro experiments showed that the knockdown of S100P suppressed the proliferation, adhesion, migrative and invasive abilities of T47D and SK-BR-3 breast cancer cells. We further demonstrated that this knockdown increased the chemoresistance to paclitaxel and cisplatin in SK-BR-3 cells. We found S100P exerted its function by upregulating NF-κB, CCND1 and Vimentin, but downregulating E-cadherin. CONCLUSION: S100P promotes the aggressive properties of breast cancer cells and may be considered as a promising therapeutic target. Moreover, S100P can be used to predict the therapeutic effect of chemotherapy in HER2+ breast cancer patients.

EphB2 represents an independent prognostic marker in patients with gastric cancer and promotes tumour cell aggressiveness.

Dysregulated expression of ephrin type-B receptor 2 (EphB2) has been linked with the development and progression of solid tumours. In the current study, we attempted to investigate the clinical relevance in GC and the effect of EphB2 expression on gastric cancer (GC) cells. EphB2 protein levels in GC and benign gastric tissues were determined using immunohistochemistry. EphB2 transcript expression in a GC cohort with GC tissue samples (n=171) and paired adjacent normal gastric tissues (n=97) was determined using qPCR. The EphB2 expression was over-activated using a CRISPR activator for the investigation of its cellular function. The expression levels of the EphB2 protein in the tumour tissues of tissue arrays were higher than the benign non-cancerous gastric tissues (P<0.05). EphB2 mRNA expression in GC tissues was also significantly elevated when compared with adjacent non-cancerous tissues (P<0.01). EphB2 activation promoted the migration and invasion abilities of the GC cell lines (P<0.01, respectively). In contrast, EphB2 activation significantly decreased the adhesion in GC cells (P<0.0001, respectively). The enrichment analysis of the correlated genes in a GC cohort indicates that EphB2 may function through mediating the cytokine-cytokine interaction, JAK-STAT and TP53 signaling pathways. In conclusion, EphB2 represents as a novel independent prognostic marker in GC. And activation of the EphB2 gene expression elevated the levels of migration and invasion, but suppressed adhesion of GC cells, indicating that EphB2 may act as a tumour promotor in GC. Our findings thus provide fundamental evidence for the consideration of the therapeutic potential of targeting EphB2 in GC.

Identification of DHX36 as a tumour suppressor through modulating the activities of the stress-associated proteins and cyclin-dependent kinases in breast cancer.

The nucleic acid guanine-quadruplex structures (G4s) are involved in many aspects of cancer progression. The DEAH-box polypeptide 36 (DHX36) has been identified as a dominant nucleic acid helicase which targets and disrupts DNA and RNA G4s in an ATP-dependent manner. However, the actual role of DHX36 in breast cancer remains unknown. In this study, we observed that the gene expression of DHX36 was positively associated with patient survival in breast cancer. The abundance of DHX36 is also linked with pathologic conditions and the stage of breast cancer. By using the xenograft mouse model, we demonstrated that the stable knockdown of DHX36 via lentivirus in breast cancer cells significantly promoted tumour growth. We also found that, after the DHX36 knockdown (KD), the invasion of triple-negative breast cancer cells was enhanced. In addition, we found a significant increase in the number of cells in the S-phase and a reduction of apoptosis with the response to cisplatin. DHX36 KD also desensitized the cytotoxic cellular response to paclitaxel and cisplatin. Transcriptomic profiling analysis by RNA sequencing indicated that DHX36 altered gene expression profile through the upstream activation of TNF, IFNγ, NFκb and TGFß1. High throughput signalling analysis showed that one cluster of stress-associated kinase proteins including p53, ROCK1 and JNK were suppressed, while the mitotic checkpoint protein-serine kinases CDK1 and CDK2 were activated, as a consequence of the DHX36 knockdown. Our study reveals that DHX36 functions as a tumour suppressor and may be considered as a potential therapeutic target in breast cancer.

OPN promotes the aggressiveness of non-small-cell lung cancer cells through the activation of the RON tyrosine kinase.

Osteopontin (OPN) is identified as a diagnostic and prognostic biomarker of tumor progression and metastasis. In non-small-cell lung cancer (NSCLC), the functions of OPN have not been well characterized. The current study sought to investigate the clinical implications of OPN expression in NSCLC and the role of OPN in the aggressiveness of the lung cancer cells. Using a proteomics approach, we identified that phospho-RON (p-RON) was one of the most remarkably up-regulated proteins in OPN-overexpressing cells. The levels of OPN and RON transcripts were unveiled as independent prognostic indicators of survival in NSCLC (p = 0.001). Higher levels of OPN, RON and p-RON proteins were observed in tumor tissues. Knock down of the OPN gene suppressed the migration and invasion abilities of the A549 lung cancer cells which endogenously expresses OPN. While ectopic expression of OPN in the SK-MES-1 lung cancer cells increased levels of cellular invasion and migration. In addition, these changes were accompanied by a phosphorylated activation of RON. Small-molecule inhibition of RON or siRNA silencing of RON significantly reduced OPN-induced migration and invasion of lung cancer cells and had an inhibitory effect on the OPN-mediated cell epithelial-mesenchymal transition. Our study suggests that in NSCLC, the aberrant expression of OPN can be considered as an independent survival indicator and is associated with disease progression. OPN plays a crucial role in promoting migration and invasion properties of lung cancer cells through its phosphorylation activation of the RON signaling pathway, implying its potential as a therapeutic target in the treatment of NSCLC.

Determinants of physiological uptake of 18F-fluorodeoxyglucose in palatine tonsils.

To determine the extent of physiological variation of uptake of F-flurodeoxyglucose (FDG) within palatine tonsils. To define normal limits for side-to-side variation and characterize factors affecting tonsillar uptake of FDG.Over a period of 16 weeks 299 adult patients at low risk for head and neck pathology, attending our center for FDG positron emission tomography/computed tomography (PET/CT) scans were identified. The maximum standardized uptake value (SUVmax) was recorded for each palatine tonsil. For each patient age, gender, smoking status, scan indication and prior tonsillectomy status as well as weather conditions were noted.There was a wide variation in palatine tonsil FDG uptake with SUVmax values between 1.3 and 11.4 recorded. There was a strong left to right correlation for tonsillar FDG uptake within each patient (P < .01). The right palatine tonsil showed increased FDG uptake (4.63) compared to the left (4.47) (P < .01). In multivariate analysis, gender, scan indication, and prevailing weather had no significant impact of tonsillar FDG uptake. Lower tonsillar uptake was seen in patients with a prior history of tonsillectomy (4.13) than those without this history (4.64) (P < .01). Decreasing tonsillar FDG uptake was seen with advancing age (P < .01). Significantly lower uptake was seen in current smokers (SUVmax 4.2) than nonsmokers (SUV 4.9) (P = .03).Uptake of FDG in palatine tonsils is variable but shows a strong side-to-side correlation. We suggest the left/ right SUVmax ratio as a guide to normality with a first to 99th percentiles of (0.70-1.36) for use in patients not suspected to have tonsillar pathology.