Down regulation of lactotransferrin enhanced radio-sensitivity of nasopharyngeal carcinoma

INTRODUCTION

It is reported that LTF had a radiation resistance effect, and its expression in nasopharyngeal carcinoma (NPC) was significantly down-regulated. However, the mechanism of down-regulated LTF affecting the sensitivity of radiotherapy has remained elusive.

METHODS

We re-analyzed the microarray data GSE36972 and GSE48503 to find differentially expressed genes (DEGs) in NPC cell line 5-8 F transfected with LTF or vector control, and the DEGs between radio-resistant and radio-sensitive NPC cell lines. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and protein-protein interaction network (PPI) analysis of DEGs were performed to obtain the node genes. The target genes of miR-214 were also predicted to complement the mechanism associated with radiotherapy resistance because it could directly target LTF.

RESULTS

This study identified 1190 and 1279 DEGs, respectively. GO and KEGG analysis showed that apoptotic process and proliferation, PI3K-Akt signaling pathway were significantly enriched pathways. Four nodes (DUSP1, PPARGC1A, FOS and SMARCA1) associated with LTF were screened. And 42 target genes of miR-214 were cross-linked to radiotherapy sensitivity.

CONCLUSIONS

The present study demonstrates the possible molecular mechanism that the down-regulated LTF enhances the radiosensitivity of NPC cells through interaction with DUSP1, PPARGC1A, FOS and SMARCA1, and miR-214 as its superior negative regulator may play a role in regulating the radiotherapy effect.

Near-Infrared Light-Responsive Nitric Oxide Delivery Platform for Enhanced Radioimmunotherapy

Radiotherapy (RT) is a widely used way for cancer treatment. However, the efficiency of RT may come with various challenges such as low specificity, limitation by resistance, high dose and so on. Nitric oxide (NO) is known a very effective radiosensitizer of hypoxic tumor. However, NO cannot circulate in body with high concentration. Herein, an NIR light-responsive NO delivery system is developed for controlled and precisely release of NO to hypoxic tumors during radiotherapy. Tert-Butyl nitrite, which is an efficient NO source, is coupled to Ag₂S quantum dots (QDs). NO could be generated and released from the Ag₂S QDs effectively under the NIR irradiation due to the thermal effect. In addition, Ag is also a type of heavy metal that can benefit the RT therapy. We demonstrate that Ag₂S NO delivery platforms remarkably maximize radiotherapy effects to inhibit tumor growth in CT26 tumor model. Furthermore, immunosuppressive tumor microenvironment is improved by our NO delivery system, significantly enhancing the anti-PD-L1 immune checkpoint blockade therapy. 100% survival rate is achieved by the radio-immune combined therapy strategy based on the Ag₂S NO delivery platforms. Our results suggest the promise of Ag₂S NO delivery platforms for multifunctional cancer radioimmunotherapy.

LncRNA GAS5 confers the radio sensitivity of cervical cancer cells via regulating miR-106b/IER3 axis

OBJECTIVE

The aim of the study was to investigate the biological role of growth arrest special 5 (GAS5) in the radio sensitivity of cervical cancer (CC).

METHODS

The expressions of GAS5, miR-106b and immediate early response 3 (IER3) were detected in CC tissues and CC cell lines. RNA immunoprecipitation and RNA pull-down assays were performed to test the interaction of GAS5 and miR-106b. Dual-luciferase reporter assay was used to detect the regulatory relationship between miR-106b and IER3. The nude mouse model of CC was established for verifying the effects of GAS5 on the resistance of CC to radiation therapy in vivo.

RESULTS

GAS5 and IER3 were low expressed in the radio-resistant human CC tissues and SiHa cells, while miR-106b expression was highly expressed. Overexpression of IER3 or GAS5 enhanced radio-sensitivity in SiHa cells, while knockdown of IER3 or GAS5 decreased radio-sensitivity in ME180 cells. Moreover, GAS5 served as a miR-106b sponge, and miR-106b negatively regulated IER3 expression. Besides, GAS5 could regulate IER3 expression through miR-106b, and GAS5 enhanced the radio-sensitivity in CC cells through inhibiting miR-106b both in vitro and in vivo.

CONCLUSION

Overexpression of GAS5 enhanced the sensitivity of CC cells to radiation treatment via up-regulating IER3 through miR-106b.

The first-in-class alkylating deacetylase inhibitor molecule tinostamustine shows antitumor effects and is synergistic with radiotherapy in preclinical models of glioblastoma

Background

The use of alkylating agents such as temozolomide in association with radiotherapy (RT) is the therapeutic standard of glioblastoma (GBM). This regimen modestly prolongs overall survival, also if, in light of the still dismal prognosis, further improvements are desperately needed, especially in the patients with O6-methylguanine-DNA-methyltransferase (MGMT) unmethylated tumors, in which the benefit of standard treatment is less. Tinostamustine (EDO-S101) is a first-in-class alkylating deacetylase inhibitor (AK-DACi) molecule that fuses the DNA damaging effect of bendamustine with the fully functional pan-histone deacetylase (HDAC) inhibitor, vorinostat, in a completely new chemical entity.

Methods

Tinostamustine has been tested in models of GBM by using 13 GBM cell lines and seven patient-derived GBM proliferating/stem cell lines in vitro. U87MG and U251MG (MGMT negative), as well as T98G (MGMT positive), were subcutaneously injected in nude mice, whereas luciferase positive U251MG cells and patient-derived GBM stem cell line (CSCs-5) were evaluated the orthotopic intra-brain in vivo experiments.

Results

We demonstrated that tinostamustine possesses stronger antiproliferative and pro-apoptotic effects than those observed for vorinostat and bendamustine alone and similar to their combination and irrespective of MGMT expression. In addition, we observed a stronger radio-sensitization of single treatment and temozolomide used as control due to reduced expression and increased time of disappearance of γH2AX indicative of reduced signal and DNA repair. This was associated with higher caspase-3 activation and reduction of RT-mediated autophagy. In vivo, tinostamustine increased time-to-progression (TTP) and this was additive/synergistic to RT. Tinostamustine had significant therapeutic activity with suppression of tumor growth and prolongation of DFS (disease-free survival) and OS (overall survival) in orthotopic intra-brain models that was superior to bendamustine, RT and temozolomide and showing stronger radio sensitivity.

Conclusions

Our data suggest that tinostamustine deserves further investigation in patients with glioblastoma.

Electronic supplementary material

The online version of this article (10.1186/s13045-018-0576-6) contains supplementary material, which is available to authorized users.