MicroRNA-26b suppresses autophagy in breast cancer cells by targeting DRAM1 mRNA, and is downregulated by irradiation

Radio-miRs: a comprehensive view of radioresistance-related microRNAs

Radiotherapy is a key treatment option for a wide variety of human tumors, employed either alone or alongside with other therapeutic interventions. Radiotherapy uses high-energy particles to destroy tumor cells, blocking their ability to divide and proliferate. The effectiveness of radiotherapy is due to genetic and epigenetic factors that determine how tumor cells respond to ionizing radiation. These factors contribute to the establishment of resistance to radiotherapy, which increases the risk of poor clinical prognosis of patients. Although the mechanisms by which tumor cells induce radioresistance are unclear, evidence points out several contributing factors including the overexpression of DNA repair systems, increased levels of reactive oxygen species, alterations in the tumor microenvironment, and enrichment of cancer stem cell populations. In this context, dysregulation of microRNAs or miRNAs, critical regulators of gene expression, may influence how tumors respond to radiation. There is increasing evidence that miRNAs may act as sensitizers or enhancers of radioresistance, regulating key processes such as the DNA damage response and the cell death signaling pathway. Furthermore, expression and activity of miRNAs have shown informative value in overcoming radiotherapy and long-term radiotoxicity, revealing their potential as biomarkers. In this review, we will discuss the molecular mechanisms associated with the response to radiotherapy and highlight the central role of miRNAs in regulating the molecular mechanisms responsible for cellular radioresistance. We will also review radio-miRs, radiotherapy-related miRNAs, either as sensitizers or enhancers of radioresistance that hold promise as biomarkers or pharmacological targets to sensitize radioresistant cells.

[MiR-26-3p regulates proliferation, migration, invasion and apoptosis of glioma cells by targeting CREB1]

OBJECTIVE

To investigate the regulatory role of miR-26b-3p in proliferation, migration and invasion of glioma.

METHODS

The expressions of miR-26b-3p and cAMP-responsive element binding protein 1 (CREB1) in gliomas of different pathological grades were detected with RT-qPCR and Western blotting. Bioinformatic methods were used to analyze the target sequence of miRNA-26b-3p binding to CREB1, and dual luciferase gene reporter experiment was performed to explore the mechanism for targeted regulation of CREB1 by miR-26b-3p. Glioma U251 cells were treated with miR-26b-3p mimic or inhibitor, and the changes in CREB1 expression and cell proliferation, migration, invasion and apoptosis were determined with Western blotting, CCK-8 assay, wound healing assay, Transwell assay, and flow cytometry.

RESULTS

The expression of miR-26b-3p decreased while CREB1 expression increased significantly as the pathological grade of gliomas increased (P < 0.05). Dual luciferase gene reporter experiment confirmed that CREB1 was a downstream target of miR-26b-3p. Inhibition of miR-26b-3p significantly upregulated the expression of CERB1, suppressed apoptosis and promoted proliferation and invasion of glioma cells, and overexpression of miR-26b-3p produced the opposite effects (P < 0.05).

CONCLUSION

MiR-26b-3p regulates CREB1 expression to modulate apoptosis, proliferation, migration and invasion of glioma cells, thereby participating in tumorigenesis and progression of glioma.

Role of non-coding RNAs in response of breast cancer to radiation therapy

Breast cancer ranks as the first common cancer with a high incidence rate and mortality among women. Radiation therapy is the main therapeutic method for breast cancer patients. However, radiation resistance of tumor cells can reduce the efficacy of treatment and lead to recurrence and mortality in patients. Non-coding RNA (ncRNAs) refers to a group of small RNA molecules that are not translated into protein, while they have the ability to modulate the translation of target mRNA. Several studies have reported the altered expression of ncRNAs in response to radiation in breast cancer. NcRNAs have been found to influence on radiation response of breast cancer by regulating various mechanisms, including DNA damage response, cell cycle regulation, cell death, inflammatory response, cancer stem cell and EGFR related pathways. This paper aimed to provide a summary of current findings on ncRNAs dysregulation after irradiation. We also present the function and mechanism of ncRNAs in modulating radiosensitivity or radioresistance of breast cancer cells.

Contribution of miRNAs in the Pathogenesis of Breast Cancer

Breast cancer is the most frequently diagnosed cancer among females. Gene expression profiling methods have shown the deregulation of several genes in breast cancer samples and have confirmed the heterogeneous nature of breast cancer at the genomic level. microRNAs (miRNAs) are among the recently appreciated contributors in breast carcinogenic processes. These small-sized transcripts have been shown to partake in breast carcinogenesis through modulation of apoptosis, autophagy, and epithelial-mesenchymal transition. Moreover, they can confer resistance to chemotherapy. Based on the contribution of miRNAs in almost all fundamental aspects of breast carcinogenesis, therapeutic intervention with their expression might affect the course of this disorder. Moreover, the presence of miRNAs in the peripheral blood of patients potentiates these transcripts as tools for non-invasive diagnosis of breast cancer.

Regulation of autophagy by microRNAs in human breast cancer

Breast cancer is the most common solid cancer that affects female population globally. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate post-transcriptional modification of multiple downstream genes. Autophagy is a conserved cellular catabolic activity that aims to provide nutrients and degrade un-usable macromolecules in mammalian cells. A number of in vitro, in vivo and clinical studies have reported that some miRNAs could modulate autophagy activity in human breast cancer cells, and these would influence human breast cancer progression and treatment response. Therefore, this review was aimed to discuss the roles of autophagy-regulating miRNAs in influencing breast cancer development and treatment response. The review would first introduce autophagy types and process, followed by the discussion of the roles of different miRNAs in modulating autophagy in human breast cancer, and to explore how would this miRNA-autophagy regulatory process affect the disease progression or treatment response. Lastly, the potential applications and challenges of utilizing autophagy-regulating miRNAs as breast cancer biomarkers and novel therapeutic agents would be discussed.

Integrated analysis of competing endogenous RNA in esophageal carcinoma

Background

The Competing endogenous RNA (CeRNA) network plays important roles in the development and progression of multiple human cancers. Increasing attention has been paid to CeRNA in esophageal carcinoma (ESCA).

Methods

We explored The Cancer Genome Atlas (TCGA) database and then analyzed the RNAs of 142 samples to obtain long non-coding RNAs (lncRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNAs) with different expression trends alongside the progress of ESCA. A series test of cluster (STC) analysis was carried out to identify a set of unique model expression tendencies. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to validate the function of key genes that were obtained from the STC analysis.

Results

Through our analysis, 272 lncRNAs, 87 miRNAs, and 692 mRNAs showed upward expression or downward expression trends, and these molecules were tightly involved in cell cycle, pathways in cancer, metabolic processes, and protein phosphorylation, among others. Ultimately, we constructed a CeRNA network containing a total of 71 lncRNAs, 56 miRNAs, and 125 mRNAs. The overall survival (OS) was analyzed using univariate Cox regression analysis to clarify the relationship between these key molecules from the CeRNA network and the prognosis of ESCA patients. Through survival analysis, we finally screened out two lncRNAs (DLEU2, RP11-890B15.3), three miRNAs (miR-26b-3p, miR-92a-3p, miR-324-5p), and one mRNA (SIK2) as crucial prognostic factors for ESCA.

Conclusions

The novel CeRNA network that we constructed will provide new novel prognostic biomarkers and therapeutic targets for patients with ESCA.

Long Non-Coding RNA LINC00511 Accelerates Proliferation and Invasion in Cervical Cancer Through Targeting miR-324-5p/DRAM1 Axis

Purpose

Cervical cancer is the second most prevalent female malignance, and human papillomavirus (HPV) infection is the main pathogenic factor of cervical cancer. Emerging evidence has revealed that a number of long non-coding RNAs (lncRNAs) play critical roles in the tumorigenesis and progression of cervical cancer. The aim of this study was to further investigate the precise role of lncRNA LINC00511 in HPV-negative and HPV-positive cervical cancer cells and explore the potential regulatory mechanism.

Methods

The expression of LINC00511 in cervical cancer and cell lines was examined by RT-PCR. Fluorescence in situ hybridization analysis (FISH) assay was performed to detect the localization of LINC00511 in cervical cancer cells. Loss-of-function experiments of LINC00511 by siRNA interference were performed to assess its effects on HPV-negative and HPV-positive cervical cancer cells. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to identify the target of LINC00511. Relative expression of related proteins was detected using Western blot.

Results

Herein, the results showed that LINC00511 was significantly up-regulated in cervical cancer and cell lines and mainly distributed in the cytoplasm of cervical cancer cells. Loss-of-function experiments indicated that silencing of LINC00511 inhibited the proliferation and invasion of both HPV-negative and HPV-positive cervical cancer cells, as well as promoted apoptosis by regulating the Bcl-2/Bax axis and Caspase 3 activation. Bioinformatic analysis, dual-luciferase reporter, and RIP assays showed that LINC00511 was a target of miR-324-5p, while DRAM1 was a direct target of miR-324-5p. The expression of miR-324-5p was down-regulated in cervical cancer, while the expression of DRAM1 was up-regulated. Moreover, the expression of LINC00511 was negatively correlated with miR-324-5p expression in cervical cancer tissues and positively correlated with DRAM1. Further, DRAM1 overexpression promoted both HPV-negative and HPV-positive cervical cancer cell proliferation and invasion, which could be reversed by miR-324-5p mimics or si-LINC00511.

Conclusion

Collectively, these results suggest that LINC00511 functions as a competing endogenous RNA (ceRNA) to regulate the miR-324-5p/DRAM1 axis, leading to HPV-negative and HPV-positive cervical cancer aggravation.

Non-Coding RNAs in Cancer Radiosensitivity: MicroRNAs and lncRNAs as Regulators of Radiation-Induced Signaling Pathways

Radiotherapy is a cancer treatment that applies high doses of ionizing radiation to induce cell death, mainly by triggering DNA double-strand breaks. The outcome of radiotherapy greatly depends on radiosensitivity of cancer cells, which is determined by multiple proteins and cellular processes. In this review, we summarize current knowledge on the role of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in determining the response to radiation. Non-coding RNAs modulate ionizing radiation response by targeting key signaling pathways, including DNA damage repair, apoptosis, glycolysis, cell cycle arrest, and autophagy. Additionally, we indicate miRNAs and lncRNAs that upon overexpression or inhibition alter cellular radiosensitivity. Current data indicate the potential of using specific non-coding RNAs as modulators of cellular radiosensitivity to improve outcome of radiotherapy.

FTSJ1 regulates tRNA 2'-O-methyladenosine modification and suppresses the malignancy of NSCLC via inhibiting DRAM1 expression

Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. The mechanisms underlying NSCLC tumorigenesis are incompletely understood. Transfer RNA (tRNA) modification is emerging as a novel regulatory mechanism for carcinogenesis. However, the role of tRNA modification in NSCLC remains obscure. In this study, HPLC/MS assay was used to quantify tRNA modification levels in NSCLC tissues and cells. tRNA-modifying enzyme genes were identified by comparative genomics and validated by qRT-PCR analysis. The biological functions of tRNA-modifying gene in NSCLC were investigated in vitro and in vivo. The mechanisms of tRNA-modifying gene in NSCLC were explored by RNA-seq, qRT-PCR, and rescue assays. The results showed that a total of 18 types of tRNA modifications and up to seven tRNA-modifying genes were significantly downregulated in NSCLC tumor tissues compared with that in normal tissues, with the 2'-O-methyladenosine (Am) modification displaying the lowest level in tumor tissues. Loss- and gain-of-function assays revealed that the amount of Am in tRNAs was significantly associated with expression levels of FTSJ1, which was also downregulated in NSCLC tissues and cells. Upregulation of FTSJ1 inhibited proliferation, migration, and promoted apoptosis of NSCLC cells in vitro. Silencing of FTSJ1 resulted in the opposite effects. In vivo assay confirmed that overexpression of FTSJ1 significantly suppressed the growth of NSCLC cells. Mechanistically, overexpression of FTSJ1 led to a decreased expression of DRAM1. Whereas knockdown of FTSJ1 resulted in an increased expression of DRAM1. Furthermore, silencing of DRAM1 substantially augmented the antitumor effect of FTSJ1 on NSCLC cells. Our findings suggested an important mechanism of tRNA modifications in NSCLC and demonstrated novel roles of FTSJ1 as both tRNA Am modifier and tumor suppressor in NSCLC.

MicroRNA-26b-3p/ANTXR1 signaling modulates proliferation, migration, and apoptosis of glioma

Glioma is a common malignant human brain tumor. The progression of glioma is associated with dysregulation of various microRNAs. Previous studies have demonstrated that microRNA-26b-3p (miR-26b-3p) is correlated with the pathogenesis of various tumors, but the functional role of miR-26b-3p and its underlying mechanisms in glioma are not clear. Here, we found that overexpression of miR-26b-3p repressed cell migration and proliferation and promoted apoptosis. In contrast, the opposite effects were observed when miR-26b-3p was inhibited in glioma cells. Anthrax toxin receptor 1 (ANTXR1) was confirmed to be a downstream molecule of miR-26b-3p. Reintroduction of ANTXR1 with an ORF region rescued the suppressive effects of miR-26b-3p on proliferation and migration, and inhibited the apoptosis of glioma cells. Moreover, the downstream target of miR-26b-3p, ANTXR1, was increased in glioma tissues and was inversely correlated with miR-26b-3p. MiR-26b-3p and ANTXR1 were correlated with the severity of glioma. Taken together, these results demonstrate that miR-26b-3p is a critical modulator of glioma via its downstream molecule, ANTXR1. Further, the miR-26b-3p/ANTXR1 axis may serve as a treatment or diagnostic target in glioma.

New Approaches for Quantitative Reconstruction of Radiation Dose in Human Blood Cells

In the event of a nuclear attack or large-scale radiation event, there would be an urgent need for assessing the dose to which hundreds or thousands of individuals were exposed. Biodosimetry approaches are being developed to address this need, including transcriptomics. Studies have identified many genes with potential for biodosimetry, but, to date most have focused on classification of samples by exposure levels, rather than dose reconstruction. We report here a proof-of-principle study applying new methods to select radiation-responsive genes to generate quantitative, rather than categorical, radiation dose reconstructions based on a blood sample. We used a new normalization method to reduce effects of variability of signal intensity in unirradiated samples across studies; developed a quantitative dose-reconstruction method that is generally under-utilized compared to categorical methods; and combined these to determine a gene set as a reconstructor. Our dose-reconstruction biomarker was trained using two data sets and tested on two independent ones. It was able to reconstruct dose up to 4.5 Gy with root mean squared error (RMSE) of ± 0.35 Gy on a test dataset using the same platform, and up to 6.0 Gy with RMSE of ± 1.74 Gy on a test set using a different platform.

CapG promotes resistance to paclitaxel in breast cancer through transactivation of PIK3R1/P50

Background: Chemotherapy resistance is a major problem in breast cancer treatment and a leading cause of mortality in breast cancer patients. Biomarkers for chemotherapy resistance is under investigation.

Methods: Paclitaxel resistant cells were established and subjected to RNA sequencing. Analysis combined with two additional RNA-seq datasets was conducted. CapG expression in patients with adjuvant chemotherapy was studied in breast cancer resection specimens using IHC and related to pathological response and disease-free survival. Paclitaxel resistance was assessed by half-maximal inhibitory concentrations (IC50) and a mouse xenograft model.

Results: Increased expression of actin-binding protein CapG strongly correlated with the resistance to paclitaxel chemotherapy and decreased probability to achieve pathological complete response in breast cancer patients. Overexpressing CapG significantly enhanced paclitaxel resistance in breast cancer cells and xenograft tumors. High CapG level also significantly correlated with shorter relapse-free survival as well as hyper-activation of PI3K/Akt signaling in breast cancer patients. Mechanistically, CapG enhanced PIK3R1 expression which led to increased PI3K/Akt activation. Unexpectedly, CapG was found to bind to the variant-specific promoter of PIK3R1/P50 and directly enhance its transcription. We also identified p300/CBP as a transcriptional coregulator of CapG, which is recruited to PIK3R1 promoter through interaction with CapG, thereby increasing PIK3R1/P50 transcription by enhancing histone H3K27 acetylation. Consistently, inhibiting p300/CBP substantially decreased CapG-dependent upregulation of PIK3R1/P50 and subsequent PI3K/Akt activation, resulting in increased sensitivity to paclitaxel treatment in breast cancer cells.

Conclusion: High CapG levels may predict poor paclitaxel response in breast cancer patients. Targeting CapG-mediated hyperactivation of PI3K/Akt pathway may mitigate resistance to chemotherapy in breast cancer.

Establishment and characterization of a radiation-induced dermatitis rat model

Radiation‐induced dermatitis is a common and serious side effect after radiotherapy. Current clinical treatments cannot efficiently or fully prevent the occurrence of post‐irradiation dermatitis, which remains a significant clinical problem. Resolving this challenge requires gaining a better understanding of the precise pathophysiology, which in turn requires establishment of a suitable animal model that mimics the clinical condition, and can also be used to investigate the mechanism and explore effective treatment options. In this study, a single dose of 90 Gy irradiation to rats resulted in ulceration, dermal thickening, inflammation, hair follicle loss, and sebaceous glands loss, indicating successful establishment of the model. Few hair follicle cells migrated to form epidermal cells, and both the severity of skin fibrosis and hydroxyproline levels increased with time post‐irradiation. Radiation damaged the mitochondria and induced both apoptosis and autophagy of the skin cells. Therefore, irradiation of 90 Gy can be used to successfully establish a rat model of radiation‐induced dermatitis. This model will be helpful for developing new treatments and gaining a better understanding of the pathological mechanism of radiation‐induced dermatitis. Specifically, our results suggest autophagy regulation as a potentially effective therapeutic target.

MicroRNAs and their role in environmental chemical carcinogenesis

MicroRNAs (miRNAs) are a class of small, noncoding RNA species that play crucial roles across many biological processes and in the pathogenesis of major diseases, including cancer. Recent studies suggest that the expression of miRNA is altered by certain environmental chemicals, including metals, organic pollutants, cigarette smoke, pesticides and carcinogenic drugs. In addition, extensive studies have indicated the existence and importance of miRNA in different cancers, suggesting that cancer-related miRNAs could serve as potential markers for chemically induced cancers. The altered expression of miRNA was considered to be a vital pathogenic role in xenobiotic-induced cancer development. However, the significance of miRNA in the etiology of cancer and the exact mechanisms by which environmental factors alter miRNA expression remain relatively unexplored. Hence, understanding the interaction of miRNAs with environmental chemicals will provide important information on mechanisms underlying the pathogenesis of chemically induced cancers, and effectively diagnose and treat human cancers resulting from chronic or acute carcinogen exposure. This study presents the current evidence that the miRNA deregulation induced by various chemical carcinogens, different cancers caused by environmental carcinogens and the potentially related genes in the onset or progression of cancer. For each carcinogen, the specifically expressed miRNA may be considered as the early biomarkers of the cancer process. In this review, we also summarize various target genes of the altered miRNA, oncogenes or anti-oncogenes, and the existing evidence regarding the gene regulation mechanisms of cancer caused by environmentally induced miRNA alteration. The future perspective of miRNA may become attractive targets for the diagnosis and treatment of carcinogen-induced cancer.

MicroRNA-mediated redox regulation modulates therapy resistance in cancer cells: clinical perspectives

BACKGROUND

Chemotherapy and radiation therapy are the most common types of cancer therapy. The development of chemo/radio-resistance remains, however, a major obstacle. Altered redox balances are among of the main factors mediating therapy resistance. Therefore, redox regulatory strategies are urgently needed to overcome this problem. Recently, microRNAs have been found to act as major redox regulatory factors affecting chemo/radio-resistance. MicroRNAs play critical roles in regulating therapeutic resistance through the regulation of antioxidant enzymes, redox-sensitive signaling pathways, cancer stem cells, DNA repair mechanisms and autophagy.

CONCLUSIONS

Here, we summarize current knowledge on microRNA-mediated redox regulatory mechanisms underlying chemo/radio-resistance. This knowledge may form a basis for a better clinical management of cancer patients.

Role of Autophagy in Breast Cancer Development and Progression: Opposite Sides of the Same Coin

The term "autophagy", which means "self (auto) - eating (phagy)", describes a catabolic process that is evolutionarially conserved among all eukaryotes. Although autophagy is mainly accepted as a cell survival mechanism, it also modulates the process known as "type II cell death". AKT/mTOR pathway is an upstream activator of autophagy and it is tightly regulated by the ATG (autophagy-related genes) signaling cascade. In addition, wide ranging cell signaling pathways and non-coding RNAs played essential roles in the control of autophagy. Autophagy is closely related to pathological processes such as neurodegenerative diseases and cancer as well as physiological conditions. After the Nobel Prize in Physiology or Medicine 2016 was awarded to Yoshinori Ohsumi "for his discoveries of mechanisms for autophagy", there was an explosion in the field of autophagy and molecular biologists started to pay considerable attention to the mechanistic insights related to autophagy in different diseases. Since autophagy behaved dualistically, both as a cell death and a cell survival mechanism, it opened new horizons for a deeper analysis of cell type and context dependent behavior of autophagy in different types of cancers. There are numerous studies showing that the induction of autophagy mechanism will promote survival of cancer cells. Since autophagy is mainly a mechanism to keep the cells alive, it may protect breast cancer cells against stress conditions such as starvation and hypoxia. For these reasons, autophagy was noted to be instrumental in metastasis and drug resistance. In this chapter we have emphasized on role of role of autophagy in breast cancer. Additionally we have partitioned this chapter into exciting role of microRNAs in modulation of autophagy in breast cancer. We have also comprehensively summarized how TRAIL-mediated signaling and autophagy operated in breast cancer cells.

Long Noncoding RNA Plasmacytoma Variant Translocation 1 (PVT1) Promotes Colon Cancer Progression via Endogenous Sponging miR-26b

BACKGROUND Recently, long noncoding RNAs (lncRNAs) have received wide attention in the area of tumor progression. Dysregulation of lncRNAs has been shown to participated in colon cancer, a known malignant tumor. This study aimed to identify the way lncRNA PVT1 affects the progression of colon cancer. MATERIAL AND METHODS Both human colon cancer tissues and 30 paired adjacent normal tissue samples, as well as the colon cancer cells, were collected. Then quantitative real-time (qRT-PCR) was performed to detect the expression of lncRNA PVT1 and miR-26b. Furthermore, the role of PVT1 was determined by function assays such as cell proliferation assay, invasion assay, and wound healing assay. The mechanism was studied using western blot assay and luciferase assay. RESULTS We demonstrate that the expression of PVT1 was significantly higher in tumor tissue compared with the adjacent normal tissue with a lower expression of miR-26b. Moreover, PVT1 promoted tumor growth, migration, and invasion in vitro. In addition, further experiments revealed that miR-26b was a direct target of PVT1 and could inhibit cell migration, invasion, and proliferation in colon cancer. CONCLUSIONS Our results suggest that PVT1 could promote metastasis and proliferation of colon cancer via endogenous sponging and inhibiting the expression of miR-26b, which may highlight the significance of lncRNA PVT1 in colon cancer tumorigenesis.

Autophagy-regulating microRNAs: potential targets for improving radiotherapy

BACKGROUND

Radiotherapy (RT) is one of the most important therapeutic strategies against cancer. However, resistance of cancer cells to radiation remains a major challenge for RT. Thus, novel strategies to overcome cancer cell radioresistance are urgent. Macroautophagy (hereafter referred to as autophagy) is a biological process by which damaged cell components can be removed and accordingly represent a cytoprotective mechanism. Because radiation-induced autophagy is associated with either cell death or radioresistance of cancer cells, a deeper understanding of the autophagy mechanism triggered by radiation will expedite a development of strategies improving the efficacy of RT. MicroRNAs (miRNAs) are involved in many biological processes. Mounting evidence indicates that many miRNAs are involved in regulation of the autophagic process induced by radiation insult, but the underlying mechanisms remain obscure. Therefore, a deep understanding of the mechanisms of miRNAs in regulating autophagy and radioresistance will provide a new perspective for RT against cancer.

METHODS

We summarized the recent pertinent literature from various electronic databases, including PubMed. We reviewed the radiation-induced autophagy response and its association of the role, function and regulation of miRNAs, and discussed the feasibility of targeting autophagy-related miRNAs to improve the efficacy of RT.

CONCLUSION

The beneficial or harmful effect of autophagy may depend on the types of cancer and stress. The cytoprotective role of autophagy plays a dominant role in cancer RT. For most tumor cells, reducing radiation-induced autophagy can improve the efficacy of RT. MiRNAs have been confirmed to take part in the autophagy regulatory network of cancer RT, the autophagy-regulating miRNAs therefore could be developed as potential targets for improving RT.