MiR-193b promotes autophagy and non-apoptotic cell death in oesophageal cancer cells

The interplay between autophagy and ferroptosis presents a novel conceptual therapeutic framework for neuroendocrine prostate cancer

In American men, the incidence of prostate cancer (PC) is the highest among all types of cancer, making it the second leading cause of mortality associated with cancer. For advanced or metastatic PC, antiandrogen therapies are standard treatment options. The administration of these treatments unfortunately carries the potential risk of inducing neuroendocrine prostate cancer (NEPC). Neuroendocrine differentiation (NED) serves as a crucial indicator of prostate cancer development, encompassing various factors such as phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR), Yes-associated protein 1 (YAP1), AMP-activated protein kinase (AMPK), miRNA. The processes of autophagy and ferroptosis (an iron-dependent form of programmed cell death) play pivotal roles in the regulation of various types of cancers. Clinical trials and preclinical investigations have been conducted on many signaling pathways during the development of NEPC, with the deepening of research, autophagy and ferroptosis appear to be the potential target for regulating NEPC. Due to the dual nature of autophagy and ferroptosis in cancer, gaining a deeper understanding of the developmental programs associated with achieving autophagy and ferroptosis may enhance risk stratification and treatment efficacy for patients with NEPC.

Targeting epigenetic deregulations for the management of esophageal carcinoma: recent advances and emerging approaches

Ranking from seventh in incidence to sixth in mortality, esophageal carcinoma is considered a severe malignancy of food pipe. Later-stage diagnosis, drug resistance, and a high mortality rate contribute to its lethality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two main histological subtypes of esophageal carcinoma, with squamous cell carcinoma alone accounting for more than eighty percent of its cases. While genetic anomalies are well known in esophageal cancer, accountability of epigenetic deregulations is also being explored for the recent two decades. DNA methylation, histone modifications, and functional non-coding RNAs are the crucial epigenetic players involved in the modulation of different malignancies, including esophageal carcinoma. Targeting these epigenetic aberrations will provide new insights into the development of biomarker tools for risk stratification, early diagnosis, and effective therapeutic intervention. This review discusses different epigenetic alterations, emphasizing the most significant developments in esophageal cancer epigenetics and their potential implication for the detection, prognosis, and treatment of esophageal carcinoma. Further, the preclinical and clinical status of various epigenetic drugs has also been reviewed.

Cordycepin from Cordyceps militaris ameliorates diabetic nephropathy via the miR-193b-5p/MCL-1 axis

BACKGROUND

Diabetic nephropathy (DN) is a chronic kidney disease that develops in patients with diabetes mellitus. Cordycepin (CRD), a secondary metabolite produced by Cordyceps militaris, has a variety of bioactive properties. In this study, DN mice and high glucose (HG)-treated HK-2 were used to evaluate the diagnostic value of CRD.

METHODS

Quantitative real-time PCR (qRT-PCR), western blotting, immunofluorescence analysis, and immunohistochemical staining were used to assess changes in mRNA and protein expression. Oxidative stress was evaluated by detecting the production of reactive oxygen species (ROS) and the activity of antioxidant enzymes. Cell apoptosis was detected by the TUNEL and flow cytometric methods. The interaction of miR-193b-5p and myeloid leukemia 1 (MCL-1) was examined by bioinformatics analysis and luciferase reporter assay. The protective effects of CRD on DN mice were evaluated by examining DN related biochemical indicators and renal histopathology.

RESULTS

In response to HG, the level of miR-193b-5p was elevated, whilst the level of MCL-1 was downregulated, and CRD therapy reversed this behavior. MCL-1 was further identified to be miR-193b-5p target. CRD attenuated HG-induced cell damage, inflammation and abnormal energy metabolism. Mechanistic investigations on in vitro models confirmed that protective effect of CRD against HG challenge to HK-2 cells is mediated through the regulation of expression of miR-193b-5p/MCL-1 axis. By examining DN related biochemical markers and renal histopathology, the protective effects of CRD on DN mice was assessed.

CONCLUSIONS

In summary, CRD decreased oxidative stress and inflammation by increasing miR-193b-5p and inactivating downstream MCL-1 in DN, hinting the pivotal values of CRD and miR-193b-5p in the management of DN.

Regulatory miRNAs in cancer cell recovery from therapy exposure and its implications as a novel therapeutic strategy for preventing disease recurrence

The desired outcome of cancer therapies is the eradication of disease. This can be achieved when therapy exposure leads to therapy-induced cancer cell death as the dominant outcome. Theoretically, a permanent therapy-induced growth arrest could also contribute to a complete response, which has the potential to lead to remission. However, preclinical models have shown that therapy-induced growth arrest is not always durable, as recovering cancer cell populations can contribute to the recurrence of cancer. Significant research efforts have been expended to develop strategies focusing on the prevention of recurrence. Recovery of cells from therapy exposure can occur as a result of several cell stress adaptations. These include cytoprotective autophagy, cellular quiescence, a reversable form of senescence, and the suppression of apoptosis and necroptosis. It is well documented that microRNAs regulate the response of cancer cells to anti-cancer therapies, making targeting microRNAs therapeutically a viable strategy to sensitization and the prevention of recovery. We propose that the use of microRNA-targeting therapies in prolonged sequence, that is, a significant period after initial therapy exposure, could reduce toxicity from the standard combination strategy, and could exploit new epigenetic states essential for cancer cells to recover from therapy exposure. In a step toward supporting this strategy, we survey the available scientific literature to identify microRNAs which could be targeted in sequence to eliminate residual cancer cell populations that were arrested as a result of therapy exposure. It is our hope that by successfully identifying microRNAs which could be targeted in sequence we can prevent disease recurrence.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

Noncoding RNAs in esophageal cancer: A glimpse into implications for therapy resistance

Esophageal cancer (EC) is one of the most common malignancies of the digestive system and has a high morbidity and mortality worldwide. Chemotherapy in combination with radiotherapy is one of the most important treatment modalities for EC. Chemoradiotherapy is currently acknowledged worldwide as being the standard treatment for locally advanced or unresectable disease. Unfortunately, due to the existence of therapy resistance, a number of EC patients fail to benefit from drug or irradiation treatment, which ultimately leads to poor outcomes. Considerable efforts have been made to explore the mechanisms underlying the therapy resistance of EC. Notably, noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are current research areas for the modulation of therapy responses and may serve as new targets to overcome treatment resistance in EC. Herein, we summarized the mechanisms by which ncRNAs are involved in drug and radiation resistance in EC and highlighted their role in promoting or repressing treatment resistance. Additionally, we discussed the clinical relevance of ncRNAs, which may serve as potential therapeutic targets and predictive biomarkers for EC.

Effect of paclitaxel treatment on cellular mechanics and morphology of human oesophageal squamous cell carcinoma in 2D and 3D environments

During chemotherapy, structural and mechanical changes in malignant cells have been observed in several cancers, including leukaemia and pancreatic and prostate cancer. Such cellular changes may act as physical biomarkers for chemoresistance and cancer recurrence. This study aimed to determine how exposure to paclitaxel affects the intracellular stiffness of human oesophageal cancer of South African origin in vitro. A human oesophageal squamous cell carcinoma cell line WHCO1 was cultured on glass substrates (2D) and in collagen gels (3D) and exposed to paclitaxel for up to 48 h. Cellular morphology and stiffness were assessed with confocal microscopy, visually aided morpho-phenotyping image recognition and mitochondrial particle tracking microrheology at 24 and 48 h. In the 2D environment, the intracellular stiffness was higher for the paclitaxel-treated than for untreated cells at 24 and 48 h. In the 3D environment, the paclitaxel-treated cells were stiffer than the untreated cells at 24 h, but no statistically significant differences in stiffness were observed at 48 h. In 2D, paclitaxel-treated cells were significantly larger at 24 and 48 h and more circular at 24 but not at 48 h than the untreated controls. In 3D, there were no significant morphological differences between treated and untreated cells. The distribution of cell shapes was not significantly different across the different treatment conditions in 2D and 3D environments. Future studies with patient-derived primary cancer cells and prolonged drug exposure will help identify physical cellular biomarkers to detect chemoresistance onset and assess therapy effectiveness in oesophageal cancer patients.

Autophagy in gastrointestinal cancers

Gastrointestinal cancers are a group of cancers occurred in gastrointestinal tissues with high morbidity and mortality rate. Although numerous studies were conducted on the investigation of gastrointestinal cancers, the real mechanisms haven’t been discovered, and no effective methods of prevention and treatment of gastrointestinal cancers have been developed. Autophagy, a vital catabolic process in organisms, have been proven to participate in various mechanisms and signaling pathways, thus producing a regulatory effect on various diseases. The role of autophagy in gastrointestinal cancers remains unclear due to its high complexity. In this review, firstly, the biological features of autophagy will be introduced. Secondly, the role of autophagy in three popular gastrointestinal cancers, namely esophageal cancer, gastric cancer, and colorectal cancer will be described and discussed by reviewing the related literature. We aimed to bring novel insights in exploring the real mechanisms for gastrointestinal cancers and developing effective and efficient therapeutic methods to treat gastrointestinal cancers.

The Effect of Endoscopy on Patients with Malignant Esophageal Cancer after Medical Treatment and Chemotherapy

The esophagus is one of the most commonly used parts in a person’s life, and its importance is self-evident. With the unhealthy food diet, people are more and more likely to suffer from esophageal cancer, and there is an urgent need for breakthroughs in the treatment of esophageal cancer. This article is aimed at studying the effects of medical treatment and chemotherapy for patients with malignant esophageal cancer. To this end, this article proposes a treatment method based on endoscopy and improves the image imaging of the endoscopy and the image quality of the image and the edge processing of the image. At the same time, this article designs an experiment to conduct statistical analysis of the situation during the treatment process. The experimental results in this article show that the improved treatment method has a 21% increase in success rate compared with the existing treatment method. And the optimized image quality has increased by 27%. It can very well help the attending doctor to improve the efficiency of treatment in the actual treatment process. Its most important contribution is that through the edge optimization and image enhancement processing technology, the success rate of endoscopic treatment has been better improved, and the treatment efficiency has also been improved.

The MicroRNA-Based Strategies to Combat Cancer Chemoresistance via Regulating Autophagy

Chemoresistance frequently occurs in cancer treatment, which results in chemotherapy failure and is one of the most leading causes of cancer-related death worldwide. Understanding the mechanism of chemoresistance and exploring strategies to overcome chemoresistance have become an urgent need. Autophagy is a highly conserved self-degraded process in cells. The dual roles of autophagy (pro-death or pro-survival) have been implicated in cancers and chemotherapy. MicroRNA (miRNA) is a class of small non-coding molecules that regulate autophagy at the post-transcriptional level in cancer cells. The association between miRNAs and autophagy in cancer chemoresistance has been emphasized. In this review, we focus on the dual roles of miRNA-mediated autophagy in facilitating or combating chemoresistance, aiming to shed lights on the potential role of miRNAs as targets to overcome chemoresistance.

The Use of miRNAs in Predicting Response to Neoadjuvant Therapy in Oesophageal Cancer

Oesophageal cancer (OC) is the ninth most common cancer worldwide. Patients receive neoadjuvant therapy (NAT) as standard of care, but less than 20% of patients with oesophageal adenocarcinoma (OAC) or a third of oesophageal squamous cell carcinoma (OSCC) patients, obtain a clinically meaningful response. Developing a method of determining a patient's response to NAT before treatment will allow rational treatment decisions to be made, thus improving patient outcome and quality of life. (1) Background: To determine the use and accuracy of microRNAs as biomarkers of response to NAT in patients with OAC or OSCC. (2) Methods: MEDLINE, EMBASE, Web of Science and the Cochrane library were searched to identify studies investigating microRNAs in treatment naïve biopsies to predict response to NAT in OC patients. (3) Results: A panel of 20 microRNAs were identified as predictors of good or poor response to NAT, from 15 studies. Specifically, miR-99b, miR-451 and miR-505 showed the strongest ability to predict response in OAC patients along with miR-193b in OSCC patients. (4) Conclusions: MicroRNAs are valuable biomarkers of response to NAT in OC. Research is needed to understand the effects different types of chemotherapy and chemoradiotherapy have on the predictive value of microRNAs; studies also require greater standardization in how response is defined.

Novel Implications of MicroRNAs, Long Non-coding RNAs and Circular RNAs in Drug Resistance of Esophageal Cancer

Esophageal cancer is the eighth most common malignancy and the sixth leading cause of cancer-related deaths worldwide. Chemotherapy based on platinum drugs, 5-fluorouracil, adriamycin, paclitaxel, gemcitabine, and vinorelbine, as well as targeted treatment and immunotherapy with immune checkpoint inhibitors improved the prognosis in a portion of patients with advanced esophageal cancer. Unfortunately, a number of esophageal cancer patients develop drug resistance, resulting in poor outcomes. Multiple mechanisms contributing to drug resistance of esophageal cancer have been reported. Notably, non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), have been identified to play crucial roles in modulating esophageal cancer drug resistance. In the present review, we highlight the underlying mechanisms how miRNAs, lncRNAs, and circRNAs impact the drug resistance of esophageal cancer. Several miRNAs, lncRNAs, and circRNAs may have potential clinical implications as novel biomarkers and therapeutic targets for esophageal cancer.

The role of non-apoptotic cell death in the treatment and drug-resistance of digestive tumors

Tumor cell apoptosis evasion is one of the main reasons for easy metastasis occurrence, chemotherapy resistance, and the low five-year survival rate of digestive system tumors. Current research has shown that non-apoptotic cell death plays an important role in tumors of the digestive system. Therefore, increasing the proportion of non-apoptotic tumor cells is one of the effective methods of improving therapeutic efficacies for digestive system tumors. Non-apoptotic cell death modes mainly include autophagic cell death, pyroptosis, ferroptosis, in addition to other cell death modes. This review covers a systematic review relating to the research progress made into autophagic cell death, pyroptosis, ferroptosis, and other cell death modes in the treatment of digestive system tumors. It also highlights how treatment is a reasonable prospect based on clinical experience and provides reliable guidance for the further development of digestive system tumor treatments.

5-Fluorouracil: A Narrative Review on the Role of Regulatory Mechanisms in Driving Resistance to This Chemotherapeutic Agent

5-fluorouracil (5-FU) is among the mostly administrated chemotherapeutic agents for a wide variety of neoplasms. Non-coding RNAs have a central impact on the determination of the response of patients to 5-FU. These transcripts via modulation of cancer-related pathways, cell apoptosis, autophagy, epithelial-mesenchymal transition, and other aspects of cell behavior can affect cell response to 5-FU. Modulation of expression levels of microRNAs or long non-coding RNAs may be a suitable approach to sensitize tumor cells to 5-FU treatment via modulating multiple biological signaling pathways such as Hippo/YAP, Wnt/β-catenin, Hedgehog, NF-kB, and Notch cascades. Moreover, there is an increasing interest in targeting these transcripts in various kinds of cancers that are treated by 5-FU. In the present article, we provide a review of the function of non-coding transcripts in the modulation of response of neoplastic cells to 5-FU.

The Emerging Roles of Autophagy-Related MicroRNAs in Cancer

Autophagy is a conserved catabolic process involving the degradation and recycling of damaged biomacromolecules or organelles through lysosomal-dependent pathways and plays a crucial role in maintaining cell homeostasis. Consequently, abnormal autophagy is associated with multiple diseases, such as infectious diseases, neurodegenerative diseases and cancer. Currently, autophagy is considered to be a dual regulator in cancer, functioning as a suppressor in the early stage while supporting the growth and metastasis of cancer cells in the later stage and may also produce therapeutic resistance. MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression at the post-transcriptional level by silencing targeted mRNA. MiRNAs have great regulatory potential for several fundamental biological processes, including autophagy. In recent years, an increasing number of studies have linked miRNA dysfunction to the growth, metabolism, migration, metastasis, and responses of cancer cells to therapy. Therefore, the study of autophagy-related miRNAs in cancer will provide insights into cancer biology and lead to the development of novel anti-cancer strategies. In the present review, we summarise the current knowledge of miRNA dysregulation during autophagy in cancer, focusing on the relationship between autophagy and miRNAs, and discuss their involvement in cancer biology and cancer treatment.

MicroRNA-141-3p regulates cellular proliferation, migration, and invasion in esophageal cancer by targeting tuberous sclerosis complex 1

MicroRNA (miR)-141-3p, which functions as an oncogene in multiple malignancies, has been shown to be highly overexpressed in esophageal cancer cells in our previous work. miR-141-3p is predicted to bind the messenger RNA (mRNA) of tuberous sclerosis complex 1 (TSC1), a tumor suppressor, with high affinity. In this study, we investigated the expression and functional interaction between miR-141-3p and TSC1 in esophageal cancer cells. Experiments were conducted in four esophageal cancer lines and in tumor cells isolated from human esophageal cancer specimens by laser capture microdissection. miR-141-3p expression was measured by real time and droplet digital PCR. Biotinylated RNA pull-down and luciferase reporter assays were used to assess binding. miR-141-3p function was tested by assessing proliferation, migration, invasion, and induction of autophagy following its silencing. We found that miR-141-3p levels were increased in TE7, OE33, and TE10 esophageal cancer cells compared to FLO-1 cells, with similar heterogeneity observed in human esophageal cancer specimens. Silencing of miR-141-3p led to increased TSC1 protein expression in these cells and was associated with increased TSC1 translation. Binding studies reveal that miR-141-3p binds to each of the predicted binding sites in the 3'-untranslated region of TSC1 mRNA. Following miR-141-3p silencing, TE7, OE33, and TE10 cells exhibited decreased proliferation, migration, and invasion, as well as enhanced autophagy. Importantly, these phenotypic effects were replicated by overexpression of TSC1 alone in these cells. Our results indicate that miR-141-3p functions in an oncogenic capacity in a subset of esophageal cancer cells, in part by suppressing TSC1 expression.

MiR-193b inhibits autophagy and apoptosis by targeting IGFBP5 in high glucose-induced trophoblasts

INTRODUCTION

Inhibiting apoptosis of trophoblasts in women with gestational diabetes mellitus (GDM) is expected to guarantee adequate nutrition for the fetus and avoid abortion. MiR-193b is one of the most downregulated miRNAs in GDM patients. However, less is known about the role of miR-193b in autophagy and apoptosis in GDM patients.

METHODS

We detected the expression of miR-193b in GDM patients. Then, we cultured human trophoblasts (HTR8 cells) with high glucose (HG) to simulate a diabetic environment in vitro, and further explored the effects of miR-193b on apoptosis and autophagy of HG-treated HTR8 cells.

RESULTS

The expression of miR-193b was significantly downregulated in the peripheral blood of GDM patients compared with healthy controls, and decreased miR-193b caused apparent autophagy and a substantially high apoptosis rate in HG-treated HTR8 cells. These effects were reversed by enhancing miR-193b expression or using the autophagy inhibitor 3-MA. Inhibiting miR-193b induced the pro-autophagic, cytostatic, and pro-apoptotic effects reduced by 3-MA in HTR8 cells upon HG treatment. Moreover, the expression of insulin-like growth factor-binding protein 5 (IGFBP5) was upregulated notably in the peripheral blood of GDM patients, and IGFBP5 appears to represent a direct miR-193b target. Note that silencing IGFBP5 blocked autophagy and apoptosis in HG-treated HTR8 cells, an effect that was diminished by inhibiting miR-193b.

CONCLUSION

Our data indicate that aberrantly low expression of miR-193b in HG-induced trophoblasts results in massive apoptosis events by upregulating IGFBP5-induced autophagy, which may trigger GDM. Therefore, miR-193b may became a potential target for GDM therapy.

Autophagy-mediating microRNAs in cancer chemoresistance

Chemoresistance is a complex phenomenon responsible for failure in response to chemotherapy agents and more than 90% of deaths in cancer patients. MicroRNAs (miRNAs), as a subgroup of non-coding RNAs with lengths between 21 and 25 nucleotides, are involved in various cancer processes like chemoresistance via interacting with their target mRNAs and suppressing their expression. Autophagy is a greatly conserved procedure involving the lysosomal degradation of cytoplasmic contents and organelles to deal with environmental stresses like hypoxia and starvation. Autophagy contributes to response to chemotherapy agents: autophagy can act as a protective mechanism for mediating the resistance in response to chemotherapy or can induce autophagic cell death and mediate the sensitivity to chemotherapy. On the other hand, one of the processes targeted by microRNAs in the regulation of chemoresistance is autophagy. Hence, we studied the literatures on chemoresistance mechanisms, the miRNAs' role in cancer, and the miRNAs' role in chemoresistance by modulating autophagy. Graphical Abstract.

MicroRNAs and colorectal cancer chemoresistance: New solution for old problem

BACKGROUND

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies with a significant mortality rate. Despite the great advances in cancer treatment in the last few decades, effective treatment of CRC is still under challenge. One of the main problems associated with CRC treatment is the resistance of cancer cells to chemotherapy drugs.

METHODS

Many studies have been carried out to identify CRC chemoresistance mechanisms, and shed light on the role of ATP-binding cassette transporters (ABC transporters), enzymes as thymidylate synthase, some signaling pathways, and cancer stem cells (CSC) in chemoresistance and failed CRC chemotherapies. Other studies have also been recently carried out to find solutions to overcome chemoresistance. Some of these studies have identified the role of miRNAs in chemoresistance of the CRC cells and the effective use of these micro-molecules to CRC treatment.

RESULTS

Considering the results of these studies, more focus on miRNAs likely leads to a proper solution to overcome CRC chemoresistance.

CONCLUSION

The current study has reviewed the related literature while discussing the efficacy of miRNAs as potential clinical tools for overcoming CRC chemoresistance and reviewing the most important chemoresistance mechanisms in CRC cells.

Autophagy in cancers including brain tumors: role of MicroRNAs

Autophagy has a crucial role in many cancers, including brain tumors. Several types of endogenous molecules (e.g. microRNAs, AKT, PTEN, p53, EGFR, and NF1) can modulate the process of autophagy. Recently miRNAs (small non-coding RNAs) have been found to play a vital role in the regulation of different cellular and molecular processes, such as autophagy. Deregulation of these molecules is associated with the development and progression of different pathological conditions, including brain tumors. It was found that miRNAs are epigenetic regulators, which influence the level of proteins coded by the targeted mRNAs with any modification of the genetic sequences. It has been revealed that various miRNAs (e.g., miR-7-1-3p, miR-340, miR-17, miR-30a, miR-224-3p, and miR-93), as epigenetic regulators, can modulate autophagy pathways within brain tumors. A deeper understanding of the underlying molecular targets of miRNAs, and their function in autophagy pathways could contribute to the development of new treatment methods for patients with brain tumors. In this review, we summarize the various miRNAs, which are involved in regulating autophagy in brain tumors. Moreover, we highlight the role of miRNAs in autophagy-related pathways in different cancers.

Starvation-induced suppression of DAZAP1 by miR-10b integrates splicing control into TSC2-regulated oncogenic autophagy in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) accounts for about 90% of all incident esophageal cancers, with a 5-year survival rate of < 20%. Autophagy is of particular importance in cancers; however, the detailed regulatory mechanisms of oncogenic autophagy in ESCC have not been fully elucidated. In the present study, we address how splicing control of TSC2 is involved in mTOR-regulated oncogenic autophagy. Methods: Alternative splicing events controlled by DAZAP1 in ESCC cells were identified via RNAseq. Differential phosphorylation of short or long TSC2 splicing variants by AKT and their impacts on mTOR signaling were also examined. Results: We found that starvation-induced miR-10b could enhance autophagy via silencing DAZAP1, a key regulator of pre-mRNA alternative splicing. Intriguingly, we observed a large number of significantly changed alternative splicing events, especially exon skipping, upon RNAi of DAZAP1. TSC2 was verified as one of the crucial target genes of DAZAP1. Silencing of DAZAP1 led to the exclusion of TSC2 exon 26 (from Leu947 to Arg988), producing a short TSC2 isoform. The short TSC2 isoform cannot be phosphorylated at Ser981 by AKT, which resulted in continuous activation of TSC2 in ESCC. The active TSC2 inhibited mTOR via RHEB, leading to continually stimulated oncogenic autophagy of ESCC cells. Conclusions: Our data revealed an important physiological function of tumor suppressor DAZAP1 in autophagy regulation and highlighted the potential of controlling mRNA alternative splicing as an effective therapeutic application for cancers.

MiR-193b-5p inhibits proliferation and enhances radio-sensitivity by downregulating the AKT/mTOR signaling pathway in tongue cancer

BACKGROUND

MicroRNAs (miRNAs) have been found to have functions regulating cell proliferation, differentiation and apoptosis, thereby regulating the occurrence, development and prognosis of tumors. MiR-193b-3p is well-known for its tumorigenic effect, but there are few studies on miR-193b-5p, and its role in tongue cancer has not been reported.

METHODS

In the present research, we investigated the specific role of miR-193b-5p in tongue cancer. MiR-193b-5p mimics were transfected into tongue cancer cell lines CAL27 and TCA-8113 to generate miR-193b-5p overexpression cells. CCK-8, clonogenic assay, wound healing assay, transwell and flow cytometry analysis were performed to detect cell proliferation, migration, invasion and apoptosis.

RESULTS

Our data showed that the exogenous overexpression of miR-193b-5p blocked the proliferation, inhibited the phosphorylation of AKT and mTOR, and downregulated the levels of Cyclin D1 and P70 of CAL27 and TCA-8113 cells. We predicted that miR-193b-5p suppressed the proliferation of cancer cells by inhibiting the AKT/mTOR pathway. MiR-193b-5p mimics also induced the apoptosis of CAL27 and TCA-8113 cells by inhibiting the expression of Bcl2 and promoting the levels of Active-Caspase3 and Bax. Furthermore, a marked decline in the migration and invasiveness of tongue cancer cells transected with miR-193b-5p mimics was observed. According to the results of western blot, miR-193b-5p downregulated the levels of the epithelial-to-mesenchymal transition (EMT) markers, including N-cad, Vimentin, Snail and Slug, while upregulating E-cad expression level in CAL27 and TCA-8113 cells, suggesting that miR-193b-5p inhibited the migration and invasion by reversing the EMT process. In addition, miR-193b-5p mimics inhibited the formation of clonogenic colonies of CAL27 and TCA-8113 cells after irradiation.

CONCLUSIONS

Taken together, miR-193b-5p mimics block cell proliferation, migration and invasion and induce apoptosis by inhibiting the AKT/mTOR signaling pathway; they also reversed EMT progression and inhibited the radio-resistance of tongue cancer cells. Our results provide a potential target for the clinical treatment of human tongue cancer.

Macrophages-induced long noncoding RNA H19 up-regulation triggers and activates the miR-193b/MAPK1 axis and promotes cell aggressiveness in hepatocellular carcinoma

Dysregulation of long noncoding RNA (lncRNA) H19 has been implicated in hepatocellular carcinoma (HCC), but the concrete regulatory mechanism is lack of research. We mined gene expression profiles of 457 HCC samples from TCGA and TJMUCH cohorts and further validated in 64 FFPE HCC tissues. LncRNA H19 overexpression in situ was significantly correlated with poor prognosis of HCC patients, which induced EMT, promoted stemness and accelerated invasion of HCC cells in vitro. Co-expression network analysis indicated lncRNA H19 negatively correlated with miR-193b and positively correlated with MAPK1 gene, which implicated that lncRNA H19 served as a sponge molecule to hijack miR-193b and protect MAPK1. Forced overexpression of H19 attenuated miR-193b-mediated inhibition on multiple driver oncogenes (EGFR, KRAS, PTEN and IGF1R) and MAPK1 gene, thus triggered EMT and stem cell transformation in HCC. LncRNA H19 positively correlated with CD68 ⁺ TAMs in situ. TAMs-induced lncRNA H19 promotes HCC aggressiveness via triggering and activating the miR-193b/MAPK1 axis, mediates the crosstalk between HCC and immunological microenvironment, and causes poor clinical outcomes. LncRNA H19 is a valuable predictive biomarker and potential therapeutic target in HCC.

miR-193b Increases the Chemosensitivity of Osteosarcoma Cells by Promoting FEN1-Mediated Autophagy

Background

Osteosarcoma (OS) is one of the most common malignant bone tumors and specific microRNAs (miRNAs) are closely associated with malignant OS progression. In this study, we examined the role of microRNA-193b-3p (miR-193b) and the involvement of autophagy and apoptosis in the chemosensitivity of OS cells.

Methods

We employed qRT-PCR, Western blot, and immunohistochemistry to examine the expression levels of miR-193b, flap endonuclease 1 (FEN1), and autophagy-related proteins. Apoptosis was determined by flow cytometry using an Annexin V-FITC/PI apoptosis detection kit. Luciferase reporter assays confirmed the relationship between miR-193b and FEN1.

Results

miR-193b was downregulated in OS compared to adjacent normal tissues (p < 0.05). miR-193b overexpression in the OS cell lines induced autophagy and apoptosis, as shown by Western blotting and flow cytometry. Knockdown of FEN1, a structure-specific nuclease overexpressed in OS tissues (p < 0.001), induced apoptosis through activation of autophagy. Luciferase reporter assays confirmed that FEN1 is a direct target of miR-193b, FEN1 knockdown reinforced miR-193b induced apoptosis. Moreover, miR-193b expression enhanced epirubicin-induced autophagy and apoptosis.

Conclusion

Collectively, the results showed that miR-193b/FEN1 may serve as a novel therapeutic target for OS aimed mainly at the induction of autophagy and apoptosis. The miR-193b/FEN1 axis increased the chemosensitivity of OS cells, while activation of autophagy enhanced the anticancer effects of epirubicin.

MicroRNA-338-5p reverses chemoresistance and inhibits invasion of esophageal squamous cell carcinoma cells by targeting Id-1

5‐Fluorouracil (5‐FU) is a chemotherapeutic agent commonly used to treat esophageal squamous cell carcinoma (ESCC), but acquisition of chemoresistance frequently occurs and the underlying mechanisms are not fully understood. We found that microRNA (miR)‐338‐5p was underexpressed in ESCC cells with acquired 5‐FU chemoresistance. Forced expression of miR‐338‐5p in these cells resulted in downregulation of Id‐1, and restoration of both in vitro and in vivo sensitivity to 5‐FU treatment. The effects were abolished by reexpression of Id‐1. In contrast, miR‐338‐5p knockdown induced 5‐FU resistance in chemosensitive esophageal cell lines, and knockdown of both miR‐338‐5p and Id‐1 resensitized the cells to 5‐FU. In addition, miR‐338‐5p had suppressive effects on migration and invasion of ESCC cells. Luciferase reporter assay confirmed a direct interaction between miR‐338‐5p and the 3′‐UTR of Id‐1. We also found that miR‐338‐5p was significantly downregulated in tumor tissue and serum samples of patients with ESCC. Notably, low serum miR‐338‐5p expression level was associated with poorer survival and poor response to 5‐FU/cisplatin‐based neoadjuvant chemoradiotherapy. In summary, we found that miR‐338‐5p can modulate 5‐FU chemoresistance and inhibit invasion‐related functions in ESCC by negatively regulating Id‐1, and that serum miR‐338‐5p could be a novel noninvasive prognostic and predictive biomarker in ESCC.

Roles for Autophagy in Esophageal Carcinogenesis: Implications for Improving Patient Outcomes

Esophageal cancer is among the most aggressive forms of human malignancy with five-year survival rates of <20%. Autophagy is an evolutionarily conserved catabolic process that degrades and recycles damaged organelles and misfolded proteins to maintain cellular homeostasis. While alterations in autophagy have been associated with carcinogenesis across tissues, cell type- and context-dependent roles for autophagy have been reported. Herein, we review the current knowledge related to autophagy in esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), the two most common subtypes of esophageal malignancy. We explore roles for autophagy in the development and progression of ESCC and EAC. We then continue to discuss molecular markers of autophagy as they relate to esophageal patient outcomes. Finally, we summarize current literature examining roles for autophagy in ESCC and EAC response to therapy and discuss considerations for the potential use of autophagy inhibitors as experimental therapeutics that may improve patient outcomes in esophageal cancer.

Modulated Autophagy by MicroRNAs in Osteoarthritis Chondrocytes

Osteoarthritis (OA) is a chronic joint disease characterized by articular cartilage regression. The etiology of OA is diverse, the exact pathogenesis of which remains unclear. Autophagy is a conserved maintenance mechanism in eukaryotic cells. Dysfunction of chondrocyte autophagy is regarded as a crucial pathogenesis of cartilage degradation in OA. MircoRNAs (miRNAs) are a category of small noncoding RNAs, acting as posttranscriptional modulators that regulate biological processes and cell signaling pathways via target genes. A series of miRNAs are involved in the progression of chondrocyte autophagy and are connected with numerous factors and pathways. This article focuses on the mechanisms of chondrocyte autophagy in OA and reviews the role of miRNA in their modulation. Potentially relevant miRNAs are also discussed in order to provide new directions for future research and improve our understanding of the autophagic network of miRNAs.

Antrodin C, an NADPH Dependent Metabolism, Encourages Crosstalk between Autophagy and Apoptosis in Lung Carcinoma Cells by Use of an AMPK Inhibition-Independent Blockade of the Akt/mTOR Pathway

The current study aims to explore the possible anti-lung carcinoma activity of ADC as well as the underlying mechanisms by which ADC exerts its actions in NSCLC. Findings showed that ADC potently inhibited the viability of SPCA-1, induced apoptosis triggered by ROS, and arrested the cell cycle at the G2/M phase via a P53 signaling pathway. Interestingly, phenomena such as autophagosomes accumulation, conversion of the LC3-I to LC3-II, etc., indicated that autophagy could be activated by ADC. The blockage of autophagy-augmented ADC induced inhibition of cell proliferation, while autophagy activation restored cell death, indicating that autophagy had a protective effect against cell death which was induced by ADC treatment. Meanwhile, ADC treatment suppressed both the Akt/mTOR and AMPK signaling pathways. The joint action of both ADC and the autophagy inhibitor significantly increased the death of SPCA-1. An in vitro phase I metabolic stability assay showed that ADC was highly metabolized in SD rat liver microsomes and moderately metabolized in human liver microsomes, which will assist in predicting the outcomes of clinical pharmacokinetics and toxicity studies. These findings imply that blocking the Akt/mTOR signaling pathway, which was independent of AMPK inhibition, could activate ADC-induced protective autophagy in non-small-cell lung cancer cells.

MicroRNA-193b acts as a tumor suppressor gene in human esophageal squamous cell carcinoma via target regulation of KRAS

In recent years, microRNA-193b (miR-193b) is regarded as a tumor suppressor in the development and progression of various cancers. Several studies have indicated that KRAS could be regulated by miR-193b in pancreatic cancer cells. However, the function of miR-193b in human esophageal squamous cell carcinoma has not been explored intensively thus far. Herein, the relationship between miR-193b and KRAS was mainly explored in esophageal squamous cell carcinoma cells. In the present study, the expression levels of miR-193b and KRAS were assessed in both human esophageal cancer cells and tissues. The direct regulatory relationship between miR-193b and KRAS was evaluated using dual-luciferase assay. The effect of miR-193b overexpression and inhibitor on cell proliferation, migration/invasion, and apoptosis was further detected herein. Our results indicated that the expression of miR-193b was significantly lower in human esophageal cancer tissues than paracancerous tissues. The expression level of miR-193b/KRAS was stage-dependent in human esophageal cancers. KRAS was indicated as the direct target of miR-193b, and upregulation of miR-193b increased the percentage of cell apoptosis, and suppressed cell proliferation as well as cell migration/invasion via direct regulation of KRAS. Therefore, our study indicated that miR-193b plays an important role in the development and progression of human esophageal squamous cell carcinoma, which may become a novel target in the treatment of human esophageal squamous cell carcinoma in the future.

Regulation of RAB22A by mir-193b inhibits breast cancer growth and metastasis mediated by exosomes

Breast cancer is one of the main types of cancer affecting the health of females worldwide. Despite improvements in therapeutic approaches, cancer patients succumb to the disease due to metastasis itself, rather than the primary tumor from which metastases arise, emphasizing the need for the better understanding of the biological bases that contribute to disease progression. RAB22A, a member of the proto-oncogene RAS family, plays an important role in the formation, trafficking and metabolism of exosomes, and is associated with the occurrence and development of multiple human cancers. In this study, we demonstrate that the upregulation of RAB22A is associated with breast cancer progression and lymph node metastasis. We identified a signature of RAB22A and miR-193b that exhibited a negative association in metastatic as opposed to the surrounding normal cells, and RAB22A was identified as the target gene of miR-193b. While RAB22A was found to regulate exosomes-mediated breast cancer cell proliferation, invasion and migration, these biological characteristics were diminished in the breast cancer cells in which the RAB22A gene was knocked down or in the cells in which the exosomes were dissolved by proteinase K/RNase treatment. On the whole, the findings of this study demonstrate the critical role that miR-193b plays in the regulation of RAB22A-mediated exosome function during cancer growth and metastasis, which may have significant implications on cancer therapy.

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.

What Makes the Harderian Gland Transcriptome Different From Other Chicken Immune Tissues? A Gene Expression Comparative Analysis

The Harderian gland is a sparsely characterized immune tissue known to play an important role in local immunity. The function of the Harderian gland, however, is not clearly defined. Measuring the expression of all genes using RNA-seq enables the identification of genes, pathways, or networks of interest. Our relative RNA-seq expression analysis compared the chicken Harderian gland transcriptome to other important primary and secondary immune tissues including the bursa of Fabricius, thymus, and spleen of non-challenged birds. A total of 2,386 transcripts were identified as highly expressed in the Harderian gland. Gene set enrichment showed the importance of G-protein coupled receptor signaling and several immune pathways. Among the genes highly expressed in the Harderian gland were 48 miRNAs, a category of genetic elements involved in regulation of gene expression. Several identified miRNAs have immune related functions. This analysis gives insight to the unique immune processes inherent in the Harderian gland.

Serum microRNA-193b as a promising biomarker for prediction of chemoradiation sensitivity in esophageal squamous cell carcinoma patients

Esophageal squamous cell carcinoma (ESCC) is the most predominantly occurring type of esophageal cancer worldwide. Locally advanced ESCC patients are treated by neoadjuvant chemoradiation for tumor downstaging prior to tumor resection. Patients receiving this treatment have an increased expectation of cure via the following tumor resection and have better survival outcomes. However, not all patients respond well to chemoradiation and poor responders suffer from treatment-associated toxicity and complications without benefits. No method is currently available to predict patient chemoradiation response and to exclude poor responders from ineffective treatment. To address this clinical limitation, the present study aimed to identify non-invasive biomarkers for predicting patient chemoradiation response. Due to the features of microRNA (miRNA) in cancer diagnosis, prognosis and treatment response prediction, serum miRNA arrays were performed to identify potential miRNA(s) that may be used for chemoradiation response prediction in ESCC. Using an miRNA array to compare pre-treatment serum sample pools from 10 good responders and 10 poor responders, the present study identified miR-193b, miR-942 and miR-629* as candidate miRNAs for predicting chemoradiation response. Subsequent validation using reverse transcription-quantitative polymerase chain reaction confirmed that miR-193b, however not miR-942 and miR-629*, were significantly increased in sera from 24 good responders, compared with 23 poor responders. Further analyses using the receiver operating characteristic curve revealed a strong predictive power of serum miR-193b on discriminating good responders from poor responders to chemoradiation. In addition, a high serum level of miR-193b was significantly associated with better survival outcomes. Therefore, serum miR-193b may be considered a promising biomarker for predicting chemoradiation response and post-therapy survival of ESCC patients.

Molecular mechanisms and clinical implications of miRNAs in drug resistance of esophageal cancer

With the increasing incidence of esophageal cancer, drug resistance is becoming a major obstacle to successful cancer therapy since chemotherapy is regarded as a curative approach to inhibit cancer cell proliferation. Despite the great progress in anticancer treatment achieved during the last decades, the mechanisms of multidrug resistance have not been completely elucidated. Recently, accumulating studies and pre-clinical reports highlighted the role of miRNAs in the drug resistance of esophageal cancer. Areas covered: In this review, we mainly summarized the current advances of miRNAs in esophageal cancer and the mechanisms underlying drug resistance. We also reviewed the potential role of miRNAs as biomarkers for predicting drug response and prognosis. Finally, we envisaged the future orientation and challenges in translating the existing knowledge of drug resistance related miRNAs into clinical applications. Expert commentary: Based on the current knowledge of certain miRNAs, we believe that miRNAs would be helpful to overcome the drug resistance and provide personalized treatment for patients with esophageal cancer. The aims of this study were to provide a comprehensive summary on the emerging role of miRNAs in the drug resistance of esophageal cancer and attract broad attention of more researchers on this field.

miR-221 inhibits autophagy and targets TP53INP1 in colorectal cancer cells

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer-associated mortalities worldwide. MicroRNAs (miRNAs/miRs) serve important roles in tumor development, progression and metastasis. miR-221 has been reported to modulate proliferation, apoptosis, cell cycle distribution and cell migration in a variety of cancers. However, the function of miR-221 in the autophagy of cancer is unclear. In the present study, the role of miR-221 in the autophagy of CRC cells was investigated and its associated target was identified. Survival analysis using The Cancer Genome Atlas data suggested that a higher expression of miR-221 was associated with poor survival in patients with CRC. A Cell Counting kit-8 assay revealed that miR-221 promoted CRC cell proliferation. Autophagy flux analyzed by microtubule-associated protein 1 light chain 3 (LC3) turnover indicated that miR-221 reduced autophagy in CRC cells using different protease inhibitors (E64d and pepstatin A; Bafilomycin A1) in nutrient-rich medium or under starvation conditions. Tumor protein 53-induced nuclear protein 1 (TP53INP1) was identified as a potential novel target of miR-221 by bioinformative prediction. The protein expression of TP53INP1 was inversely regulated by miR-221 in CRC cells. Furthermore, luciferase activity assays were performed and indicated that miR-221 may regulate the luciferase activity of wild-type TP53INP1 without interfering with the activity of mutant TP53INP1. These data suggested that miR-221 may promote the cell proliferation of CRC via the inhibition of autophagy and targeted TP53INP1.

Dioscin enhances osteoblastic cell differentiation and proliferation by inhibiting cell autophagy via the ASPP2/NF-κβ pathway

Dioscin, a typical steroid saponin, has been reported to promote osteoblastic cell differentiation. However, the underling mechanisms remain to be elucidated. In the present study, it was identified that dioscin (0.5, 1, 5, 10 and 25 µg/ml) promoted MC3T3‑E1 cell proliferation and differentiation in a dose‑dependent manner. Western blot analysis showed that dioscin regulated autophagy‑associated protein expression in MC3T3‑E1 cells; it promoted the expression of apoptosis stimulated protein of p53‑2 (ASPP2), and inhibited the expression of nuclear factor (NF)‑κβ and microtubule‑associated protein 1 light chain 3β, in a concentration‑dependent manner. Caffeic acid phenethyl ester (CAPE) was used to inhibit the activation of NF‑κB and examine the effect of the ASPP2/NF‑κβ pathway on osteoblastic cell differentiation, proliferation and autophagy. It was identified that CAPE reversed the regulation of dioscin on osteoblastic cell differentiation, proliferation and autophagy. In conclusion, the present study revealed that dioscin promoted osteoblast proliferation and differentiation by inhibiting cell autophagy via the ASPP2/NF‑κβ pathway. These results are the first, to the best of our knowledge, to reveal the involvement of autophagy in the effects of dioscin on the prevention and therapy of osteoporosis.

MicroRNA-153 regulated AKT1 expression and suppressed cell proliferation of epithelial ovarian cancer cells

Epithelial ovarian cancer (EOC) is the most fatal malignancies in females worldwide, with increasing incidence recently in China. MiR-153 was reported to be dysregulated in some human cancers, including EOC. In this study, we explored the roles of miR-153 and its target AKT1 in regulating growth and migration in EOC. Cell proliferation was measured with a CCK-8 assay. Real-time quantitative RT-PCR was performed to investigate expression levels of miR-153. Cell cycle features were analyzed by Flow cytometry system. The direct target gene was confirmed by dual-luciferase reporter assay. We found the expression levels of miR-153 were generally lower in the EOC tissues than in the matched normal tissues. The miR-153 mimics caused significant G0/G1 arrest in A2780 cells. Overexpression of miR-153 suppressed cell proliferation and migration in ovarian cancer. Results of dual-luciferase reporter assay suggested that AKT1 was a direct target of miR-153 in ovarian cancer cells. Overexpression of AKT1 reverses the inhibition effect of miR-153 on cell proliferation. Introduction of miR-153 into EOC cell lines leaded to inhibition of cell proliferation and migration by directly targeting AKT1. MiR-153 may have prognostic or therapeutic value for the future management of ovarian cancer patients.

miR-138 suppresses the proliferation, metastasis and autophagy of non-small cell lung cancer by targeting Sirt1

The present study determined the role and mechanism of miR-138 in non-small cell lung cancer (NSCLC). In total, 45 freshly resected clinical NSCLC tissues were collected. The expression of miR-138 in tissues and cell lines were determined by real-time quantitative PCR. miR-138 mimics were transfected into A549 and Calu-3 cells in vitro, and then the effects of miR-138 on lung cancer cell proliferation, cell cycle, invasion and metastasis were investigated by CCK-8 assay, Transwell and flow cytometry, respectively. The protein expression of the potential target gene Sirt1 in lung cancer cells were determined by western blot analysis. Dual-Luciferase reporter assay was performed to further confirm whether Sirt1 was the target gene of miR-138. The expression of miR-138 was significantly lower in lung cancer tissues and was negatively correlated to the differentiation degree and lymph node metastasis of lung cancer. In vitro experiment results showed that miR-138 inhibited lung cancer cell proliferation, invasion and migration. It was verified that miR-138 could downregulate Sirt1 protein expression, inhibit epithelial-mesenchymal transition (EMT), decrease the activity of AMPK signaling pathway and elevate mTOR phosphorylation level. Dual-Luciferase reporter assay demonstrated that miR-138 could directly regulate Sirt1. Downregulation of Sirt1 alone can also cause the same molecular and biological function changes. Western blot analysis and confocal microscopy results indicated that overexpression of miR-138 or interference of Sirt1 expression could inhibit lung cancer cell autophagy activity possibly through AMPK-mTOR signaling pathway. miR-138 plays a tumor suppressor function in lung cancer. It may inhibit the proliferation, invasion and migration of lung cancer through downregulation of Sirt1 expression and activation of cell autophagy. The downregulation of miR-138 is closely related to the development of lung cancer.

Autophagy-Regulating microRNAs and Cancer

Macroautophagy (autophagy herein) is a cellular stress response and a survival pathway that is responsible for the degradation of long-lived proteins, protein aggregates, as well as damaged organelles in order to maintain cellular homeostasis. Consequently, abnormalities of autophagy are associated with a number of diseases, including Alzheimers’s disease, Parkinson’s disease, and cancer. According to the current view, autophagy seems to serve as a tumor suppressor in the early phases of cancer formation, yet in later phases, autophagy may support and/or facilitate tumor growth, spread, and contribute to treatment resistance. Therefore, autophagy is considered as a stage-dependent dual player in cancer. microRNAs (miRNAs) are endogenous non-coding small RNAs that negatively regulate gene expression at a post-transcriptional level. miRNAs control several fundamental biological processes, and autophagy is no exception. Furthermore, accumulating data in the literature indicate that dysregulation of miRNA expression contribute to the mechanisms of cancer formation, invasion, metastasis, and affect responses to chemotherapy or radiotherapy. Therefore, considering the importance of autophagy for cancer biology, study of autophagy-regulating miRNA in cancer will allow a better understanding of malignancies and lead to the development of novel disease markers and therapeutic strategies. The potential to provide study of some of these cancer-related miRNAs were also implicated in autophagy regulation. In this review, we will focus on autophagy, miRNA, and cancer connection, and discuss its implications for cancer biology and cancer treatment.

Combination of Endothelial-Monocyte-Activating Polypeptide-II with Temozolomide Suppress Malignant Biological Behaviors of Human Glioblastoma Stem Cells via miR-590-3p/MACC1 Inhibiting PI3K/AKT/mTOR Signal Pathway

This study aims to investigate the effect of Endothelial-Monocyte-Activating Polypeptide-II (EMAP-II) combined with temozolomide (TMZ) upon glioblastoma stem cells (GSCs) and its possible molecular mechanisms. In this study, combination of EMAP-II with TMZ inhibited cell viability, migration and invasion in GSCs, and autophagy inhibitor 3-methyl adenine (3-MA) and chloroquine (CQ) partly reverse the anti-proliferative effect of the combination treatment. Autophagic vacuoles were formed in GSCs after the combination therapy, accompanied with the up-regulation of LC3-II and Beclin-1 as well as the down-regulation of p62/SQSTM1. Further, miR-590-3p was up-regulated and Metastasis-associated in colon cancer 1 (MACC1) was down-regulated by the combination treatment in GSCs; MiR-590-3p overexpression and MACC1 knockdown up-regulated LC3-II and Beclin-1 as well as down-regulated p62/SQSTM1 in GSCs; MACC1 was identified as a direct target of miR-590-3p, mediating the effects of miR-590-3p in the combination treatment. Furthermore, the combination treatment and MACC1 knockdown decreased p-PI3K, p-Akt, p-mTOR, p-S6 and p-4EBP in GSCs; PI3K/Akt agonist insulin-like growth factor-1(IGF-1) partly blocked the effect of the combination treatment. Moreover, in vivo xenograft models, the mice given stable overexpressed miR-590-3p cells and treated with EMAP-II and TMZ had the smallest tumor sizes, besides, miR-590-3p + EMAP-II + TMZ up-regulated the expression level of miR-590-3p, LC3-II and Beclin-1 as well as down-regulated p62/SQSTM1. In conclusion, these results elucidated anovel molecular mechanism of EMAP-II in combination with TMZ suppressed malignant biological behaviors of GSCs via miR-590-3p/MACC1 inhibiting PI3K/AKT/mTOR signaling pathway, and might provide potential therapeutic approaches for human GSCs.

Tumor-Host Cell Interactions in Ovarian Cancer: Pathways to Therapy Failure

Although most ovarian cancer patients are highly responsive to chemotherapy, they frequently present with recurrent metastatic lesions that result in poor overall survival, a situation that has not changed in the last 20 years. This review discusses new insights into the regulation of ovarian cancer chemoresistance with a focus on the emerging role of immune and other host cells. Here, we summarize the complex molecular pathways that regulate the interaction between tumor and host cells, discuss the limitations of current in vitro and in vivo models for translational studies, and present perspectives for the development of innovative therapies.

A new function for miRNAs as regulators of autophagy

Autophagy is a self-digestive process regulated by an intricate network of factors able either to ensure the prosurvival function of autophagy or to convert it in a death pathway. Recently, the involvement of miRNAs in the regulation of autophagy networks has been reported. This review will summarize the main features of these small noncoding endogenous RNAs, focusing on their relevance in cancer and finally addressing their impact on autophagy.

miR-193b directly targets STMN1 and inhibits the malignant phenotype in colorectal cancer

Accumulating evidence suggests that aberrantly expressed microRNAs (miRNAs) contribute to the initiation and progression of human cancers. However, the underlying function of miR-193b in colorectal cancer (CRC) remains largely unexplored. Herein, we demonstrate that miR-193b is significantly down-regulated in CRC tissues compared with their normal counterparts. Kaplan-Meier analysis revealed that decreased miR-193b expression was closely associated with the shorter overall survival of patients with CRC. Through gain-and loss-of-function studies, we showed that miR-193b significantly suppressed CRC cell proliferation and invasion. In addition, bioinformatics analyses and luciferase reporter assays identified Stathmin 1 (STMN1) as the direct functional target of miR-193b in CRC. Furthermore, silencing of STMN1 resulted in a phenotype similar to that observed for overexpression of miR-193b, and restoration of STMN1 expression completely rescued the inhibitory effect of miR-193b in CRC cells. Taken together, our study implies the essential role of miR-193b in negatively regulating CRC progression, and a novel link between miR-193b and STMN1 in CRC.

Stathmin-dependent molecular targeting therapy for malignant tumor: the latest 5 years' discoveries and developments

Knowledge of the molecular mechanisms on malignant tumors is very critical for the development of new treatment strategies like molecularly targeted therapies. In last 5 years, many investigations suggest that stathmin is over-expressed in a variety of human malignant tumors, and potentially promotes the occurrence and development of tumors. Rather, down-regulation of stathmin can reduce cell proliferation, motility and metastasis and induce apoptosis of malignant tumors. Thus, a stathmin antagonist, such as a specific inhibitor (antibody, small molecule compound, peptide, or siRNA), may be a novel strategy of molecular targeted therapy. This review summarizes the research progress of recent 5 years on the role of stathmin in tumorigenesis, the molecular mechanisms and development of anti-stathmin treatment, which suggest that continued investigations into the function of stathmin in the tumorigenesis could lead to more rationally designed therapeutics targeting stathmin for treating human malignant tumors.