Inhibition of cell proliferation and radioresistance by miR-383-5p through targeting RNA binding protein motif (RBM3) in nasopharyngeal carcinoma

Circ_0005231 promotes the progression of esophageal squamous cell carcinoma via sponging miR-383-5p and regulating KIAA0101

Background

Circular RNAs (circRNAs) can act as key regulators in human cancers, including esophageal squamous cell carcinoma (ESCC). However, the role and mechanism of circ_0005231 in ESCC have not previously been reported.

Methods

RNA levels and protein levels were detected by real‐time quantitative polymerase chain reaction (RT‐qPCR) and Western blot assay, respectively. Cell proliferation was assessed by colony formation assay and 5‐ethynyl‐2'‐deoxyuridine (EdU) assay. Wound healing and transwell assays were used to assess cell migration and invasion, respectively. The intermolecular interaction was predicted by bioinformatic analysis and verified by RNA immunoprecipitation (RIP), RNA pulldown and dual‐luciferase reporter assays. Xenograft tumor model was used for exploring the biological function of circ_0005231 in vivo.

Results

Circ_0005231 was upregulated in ESCC plasma, tissues and cells. Cell proliferation, migration and invasion were significantly restrained by knockdown of circ_0005231 in ESCC cells. Circ_0005231 acted as a sponge of miR‐383‐5p, and circ_0005231 regulated ESCC cellular behavior by sponging miR‐383‐5p. Moreover, miR‐383‐5p directly targeted KIAA0101, and circ_0005231 positively regulated KIAA0101 expression by sponging miR‐383‐5p. Furthermore, circ_0005231 knockdown suppressed the malignant behavior of ESCC cells by downregulating KIAA0101. Importantly, knockdown of circ_0005231 blocked xenograft tumor growth in vivo.

Conclusion

Circ_0005231 acted as a sponge of miR‐383‐5p to promote ESCC progression by upregulating KIAA0101, which provided a potential therapeutic strategy for ESCC treatment.

Involvement of Non-Coding RNAs in Chemo- and Radioresistance of Nasopharyngeal Carcinoma

The crucial treatment for nasopharyngeal carcinoma (NPC) is radiation therapy supplemented by chemotherapy. However, long-term radiation therapy can cause some genetic and proteomic changes to produce radiation resistance, leading to tumour recurrence and poor prognosis. Therefore, the search for new markers that can overcome the resistance of tumor cells to drugs and radiotherapy and improve the sensitivity of tumor cells to drugs and radiotherapy is one of the most important goals of pharmacogenomics and cancer research, which is important for predicting treatment response and prognosis. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), may play important roles in regulating chemo- and radiation resistance in nasopharyngeal carcinoma by controlling the cell cycle, proliferation, apoptosis, and DNA damage repair, as well as other signalling pathways. Recent research has suggested that selective modulation of ncRNA activity can improve the response to chemotherapy and radiotherapy, providing an innovative antitumour approach based on ncRNA-related gene therapy. Therefore, ncRNAs can serve as biomarkers for tumour prediction and prognosis, play a role in overcoming drug resistance and radiation resistance in NPC, and can also serve as targets for developing new therapeutic strategies. In this review, we discuss the involvement of ncRNAs in chemotherapy and radiation resistance in NPC. The effects of these molecules on predicting therapeutic cancer are highlighted.

Graphene Oxide-Induced Protein Conformational Change in Nasopharyngeal Carcinoma Cells: A Joint Research on Cytotoxicity and Photon Therapy

The objectives of this work aim to investigate the interaction and cytotoxicity between nanometric graphene oxide (GO) and nasopharyngeal carcinoma cells (NPC-BM1), and possible application in photon therapy. GO nanosheets were obtained in the size range of 100-200 nm, with a negative surface charge. This nanometric GO exhibited a limited (<10%) cytotoxicity effect and no significant dimensional change on NPC-BM1 cells in the tested GO concentration range (0.1-10 µg·mL-1). However, the secondary protein structure was modified in the GO-treated NPC-BM1 cells, as determined through synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIRM) mapping. To further study the cellular response of GO-treated NPC-BM1 cancer cells at low GO concentration (0.1 µg·mL-1), photon radiation was applied with increasing doses, ranging from 2 to 8 Gy. The low radiation energy (<5 Gy) did not cause significant cell mortality (5-7%). Increasing the radiation energy to 6-8 Gy accelerated cell apoptosis rate, especially in the GO-treated NPC-BM1 cells (27%). This necrosis may be due to GO-induced conformational changes in protein and DNA/RNA, resulting in cell vulnerability under photon radiation. The findings of the present work demonstrate the potential biological applicability of nanometric GO in different areas, such as targeted drug delivery, cellular imaging, and radiotherapy, etc.