MicroRNA-137 inhibits autophagy and chemosensitizes pancreatic cancer cells by targeting ATG5

Noncoding Ribonucleic Acids (RNAs) May Improve Response to Immunotherapy in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is the seventh most common cause of cancer-related mortality. Despite different methods of treatment, nearly more than 90% of patients with PDAC die shortly after diagnosis. Contrary to promising results in other cancers, immune checkpoint inhibitors (ICIs) showed limited success in PDAC. Recent studies have shown that noncoding RNAs (ncRNAs) are extensively involved in PDAC cell-immune cell interaction and mediate immune evasion in this vicious cancer. PDAC cells recruit numerous ncRNAs to widely affect the phenotype and function of immune cells through various mechanisms. For instance, PDAC cells upregulate miR-301a and downregulate miR-340 to induce M2 polarization of macrophages or overexpress miR-203, miR-146a, and miR-212-3p to downregulate toll-like receptor 4 (TLR4), CD80, CD86, CD1a, major histocompatibility complex (MHC) II, and CD83, thereby evading recognition by dendritic cells. By downregulating miR-4299 and miR-153, PDAC cells can decrease the expression of NK group 2D (NKG2D) and MHC class I chain-related molecules A and B (MICA/B) to blunt the natural killer (NK) cell response. PDAC cells also highly express lncRNA AL137789.1, hsa_circ_0046523, lncRNA LINC00460, and miR-155-5p to upregulate immune checkpoint proteins and escape T cell cytotoxicity. On the other hand, ncRNAs derived from suppressive immune cells promote proliferation, invasion, and drug resistance in PDAC cells. ncRNAs can be applied to overcome resistance to ICIs, monitor the immune microenvironment of PDAC, and predict response to ICIs. This Review article comprehensively discusses recent findings regarding the roles of ncRNAs in the immune evasion of PDAC.

Synthesis and Regulation of miRNA, Its Role in Oncogenesis, and Its Association with Colorectal Cancer Progression, Diagnosis, and Prognosis

The dysfunction of several types of regulators, including miRNAs, has recently attracted scientific attention for their role in cancer-associated changes in gene expression. MiRNAs are small RNAs of ~22 nt in length that do not encode protein information but play an important role in post-transcriptional mRNA regulation. Studies have shown that miRNAs are involved in tumour progression, including cell proliferation, cell cycle, apoptosis, and tumour angiogenesis and invasion, and play a complex and important role in the regulation of tumourigenesis. The detection of selected miRNAs may help in the early detection of cancer cells, and monitoring changes in their expression profile may serve as a prognostic factor in the course of the disease or its treatment. MiRNAs may serve as diagnostic and prognostic biomarkers, as well as potential therapeutic targets for colorectal cancer. In recent years, there has been increasing evidence for an epigenetic interaction between DNA methylation and miRNA expression in tumours. This article provides an overview of selected miRNAs, which are more frequently expressed in colorectal cancer cells, suggesting an oncogenic nature.

The structure and function of FUN14 domain-containing protein 1 and its contribution to cardioprotection by mediating mitophagy

Cardiovascular disease (CVD) is a serious public health risk, and prevention and treatment efforts are urgently needed. Effective preventive and therapeutic programs for cardiovascular disease are still lacking, as the causes of CVD are varied and may be the result of a multifactorial combination. Mitophagy is a form of cell-selective autophagy, and there is increasing evidence that mitophagy is involved in cardioprotective processes. Recently, many studies have shown that FUN14 domain-containing protein 1 (FUNDC1) levels and phosphorylation status are highly associated with many diseases, including heart disease. Here, we review the structure and functions of FUNDC1 and the path-ways of its mediated mitophagy, and show that mitophagy can be effectively activated by dephosphorylation of Ser13 and Tyr18 sites, phosphorylation of Ser17 site and ubiquitination of Lys119 site in FUNDC1. By effectively activating or inhibiting excessive mitophagy, the quality of mitochondria can be effectively controlled. The main reason is that, on the one hand, improper clearance of mitochondria and accumulation of damaged mitochondria are avoided, and on the other hand, excessive mitophagy causing apoptosis is avoided, both serving to protect the heart. In addition, we explore the possible mechanisms by which FUNDC1-mediated mitophagy is involved in exercise preconditioning (EP) for cardioprotection. Finally, we also point out unresolved issues in FUNDC1 and its mediated mitophagy and give directions where further research may be needed.

Molecular mechanisms in regulation of autophagy and apoptosis in view of epigenetic regulation of genes and involvement of liquid-liquid phase separation

Cellular physiology is critically regulated by multiple signaling nexuses, among which cell death mechanisms play crucial roles in controlling the homeostatic landscape at the tissue level within an organism. Apoptosis, also known as programmed cell death, can be induced by external and internal stimuli directing the cells to commit suicide in unfavourable conditions. In contrast, stress conditions like nutrient deprivation, infection and hypoxia trigger autophagy, which is lysosome-mediated processing of damaged cellular organelle for recycling of the degraded products, including amino acids. Apparently, apoptosis and autophagy both are catabolic and tumor-suppressive pathways; apoptosis is essential during development and cancer cell death, while autophagy promotes cell survival under stress. Moreover, autophagy plays dual role during cancer development and progression by facilitating the survival of cancer cells under stressed conditions and inducing death in extreme adversity. Despite having two different molecular mechanisms, both apoptosis and autophagy are interconnected by several crosslinking intermediates. Epigenetic modifications, such as DNA methylation, post-translational modification of histone tails, and miRNA play a pivotal role in regulating genes involved in both autophagy and apoptosis. Both autophagic and apoptotic genes can undergo various epigenetic modifications and promote or inhibit these processes under normal and cancerous conditions. Epigenetic modifiers are uniquely important in controlling the signaling pathways regulating autophagy and apoptosis. Therefore, these epigenetic modifiers of both autophagic and apoptotic genes can act as novel therapeutic targets against cancers. Additionally, liquid-liquid phase separation (LLPS) also modulates the aggregation of misfolded proteins and provokes autophagy in the cytosolic environment. This review deals with the molecular mechanisms of both autophagy and apoptosis including crosstalk between them; emphasizing epigenetic regulation, involvement of LLPS therein, and possible therapeutic approaches against cancers.

GATA3 promotes the autophagy and activation of hepatic stellate cell in hepatic fibrosis via regulating miR-370/HMGB1 pathway

BACKGROUND

Hepatic fibrosis (HF) is a common result of the repair process of various chronic liver diseases. Hepatic stellate cells (HSCs) activation is the central link in the occurrence of HF.

METHODS

ELISA and histological analysis were performed to detect the pathological changes of liver tissues. In vitro, HSCs were treated with TGF-β1 as HF cell model. Combination of GATA-binding protein 3 (GATA3) and miR-370 gene promoter was ensured by ChIP and luciferase reporter assay. Autophagy was monitored by observing the GFP-LC3 puncta formation. The interaction between miR-370 and high mobility group box 1 protein (HMGB1) was verified by luciferase reporter assay.

RESULTS

CCl4-induced HF mice exhibited an increase of ALT and AST, and severe damage and fibrosis of liver tissues. GATA3 and HMGB1 were up-regulated, and miR-370 was down-regulated in CCl4-induced HF mice and activated HSCs. GATA3 enhanced expression of the autophagy-related proteins and activation markers in the activated HSCs. Inhibition of autophagy partly reversed GATA3-induced activation of HSCs and the promotion of GATA3 to hepatic fibrosis. Moreover, GATA3 suppressed miR-370 expression via binding with its promotor, and enhanced HMGB1 expression in HSCs. Increasing of miR-370 inhibited HMGB1 expression by directly targeting its mRNA 3'-UTR. The promotion of GATA3 to TGF-β1-induced HSCs autophagy and activation was abrogated by miR-370 up-regulation or HMGB1 knockdown.

CONCLUSIONS

This work demonstrates that GATA3 promotes autophagy and activation of HSCs by regulating miR-370/HMGB1 signaling pathway, which contributes to accelerate HF. Thus, this work suggests that GATA3 may be a potential target for prevention and treatment of HF.

Functional and Potential Therapeutic Implication of MicroRNAs in Pancreatic Cancer

The alarmingly low five-year survival rate for pancreatic cancer presents a global health challenge, contributing to about 7% of all cancer-related deaths. Late-stage diagnosis and high heterogeneity are the biggest hurdles in treating pancreatic cancer. Thus, there is a pressing need to discover novel biomarkers that could help in early detection as well as improve therapeutic strategies. MicroRNAs (miRNAs), a class of short non-coding RNA, have emerged as promising candidates with regard to both diagnostics and therapeutics. Dysregulated miRNAs play pivotal roles in accelerating tumor growth and metastasis, orchestrating tumor microenvironment, and conferring chemoresistance in pancreatic cancer. The differential expression profiles of miRNAs in pancreatic cancer could be utilized to explore novel therapeutic strategies. In this review, we also covered studies on recent advancements in various miRNA-based therapeutics such as restoring miRNAs with a tumor-suppressive function, suppressing miRNA with an oncogenic function, and combination with chemotherapeutic drugs. Despite several challenges in terms of specificity and targeted delivery, miRNA-based therapies hold the potential to revolutionize the treatment of pancreatic cancer by simultaneously targeting multiple signaling pathways.

Investigating the regulatory role of miRNAs as silent conductors in the management of pathogenesis and therapeutic resistance of pancreatic cancer

Pancreatic cancer (PC) has the greatest mortality rate of all the main malignancies. Its advanced stage and poor prognosis place it at the bottom of all cancer sites. Hence, emerging biomarkers can enable precision medicine where PC therapy is tailored to each patient. This highlights the need for new, highly sensitive and specific biomarkers for early PC diagnosis. Prognostic indicators are also required to stratify PC patients. To avoid ineffective treatment, adverse events, and expenses, biomarkers are also required for patient monitoring and identifying responders to treatment. There is substantial evidence that microRNAs (miRs, miRNAs) play a critical role in regulating mRNA and, as a consequence, protein expression in normal and malignant tissues. Deregulated miRNA profiling in PC can help with diagnosis, treatment planning, and prognosis. Furthermore, knowledge of the primary effector genes and downstream pathways in PC can help pinpoint potential miRNAs for use in treatment. Different miRNA expression profiles may serve as diagnostic, prognostic markers, and therapeutic targets across the spectrum of malignant pancreatic illness. Dysregulation of miRNAs has been linked to the malignant pathophysiology of PC through affecting many cellular functions such as increasing invasive and proliferative prospect, supporting angiogenesis, cell cycle aberrance, apoptosis elusion, metastasis promotion, and low sensitivity to particular treatments. Accordingly, in the current review, we summarize the recent advances in the roles of oncogenic and tumor suppressor (TS) miRNAs in PC and discuss their potential as worthy diagnostic and prognostic biomarkers for PC, as well as their significance in PC pathogenesis and anticancer drug resistance.

Chloroquine enhances the efficacy of chemotherapy drugs against acute myeloid leukemia by inactivating the autophagy pathway

Current therapy for acute myeloid leukemia (AML) is largely hindered by the development of drug resistance of commonly used chemotherapy drugs, including cytarabine, daunorubicin, and idarubicin. In this study, we investigated the molecular mechanisms underlying the chemotherapy drug resistance and potential strategy to improve the efficacy of these drugs against AML. By analyzing data from ex vivo drug-response and multi-omics profiling public data for AML, we identified autophagy activation as a potential target in chemotherapy-resistant patients. In THP-1 and MV-4-11 cell lines, knockdown of autophagy-regulated genes ATG5 or MAP1LC3B significantly enhanced AML cell sensitivity to the chemotherapy drugs cytarabine, daunorubicin, and idarubicin. In silico screening, we found that chloroquine phosphate mimicked autophagy inactivation. We showed that chloroquine phosphate dose-dependently down-regulated the autophagy pathway in MV-4-11 cells. Furthermore, chloroquine phosphate exerted a synergistic antitumor effect with the chemotherapy drugs in vitro and in vivo. These results highlight autophagy activation as a drug resistance mechanism and the combination therapy of chloroquine phosphate and chemotherapy drugs can enhance anti-AML efficacy.

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.

A bioinformatics analysis, pre-clinical and clinical conception of autophagy in pancreatic cancer: Complexity and simplicity in crosstalk

Pancreatic cancer (PC) is a serious gastrointestinal tract disease for which the 5-year survival rate is less than 10%, even in developed countries such as the USA. The genomic profile alterations and dysregulated biological mechanisms commonly occur in PC. Macroautophagy/autophagy is a cell death process that is maintained at a basal level in physiological conditions, whereas its level often changes during tumorigenesis. The function of autophagy in human cancers is dual and can be oncogenic and onco-suppressor. Autophagy is a potent controller of tumorigenesis in PC. The supportive autophagy in PC escalates the growth rate of PC cells and its suppression can mediate cell death. Autophagy also determines the metastasis of PC cells, and it can control the EMT in affecting migration. Moreover, starvation and hypoxia can stimulate glycolysis, and glycolysis induction can be mediated by autophagy in enhancing tumorigenesis in PC. Furthermore, protective autophagy stimulates drug resistance and gemcitabine resistance in PC cells, and its inhibition can enhance radiosensitivity. Autophagy can degrade MHC-I to mediate immune evasion and also regulates polarization of macrophages in the tumor microenvironment. Modulation of autophagy activity is provided by silibinin, ursolic acid, chrysin and huaier in the treatment of PC. Non-coding RNAs are also controllers of autophagy in PC and its inhibition can improve therapy response in patients. Moreover, mitophagy shows dysregulation in PC, which can enhance the proliferation of PC cells. Therefore, a bioinformatics analysis demonstrates the dysregulation of autophagy-related proteins and genes in PC as biomarkers.

Noncoding RNAs: an emerging modulator of drug resistance in pancreatic cancer

Pancreatic cancer is the eighth leading cause of cancer-related deaths worldwide. Chemotherapy including gemcitabine, 5-fluorouracil, adriamycin and cisplatin, immunotherapy with immune checkpoint inhibitors and targeted therapy have been demonstrated to significantly improve prognosis of pancreatic cancer patients with advanced diseases. However, most patients developed drug resistance to these therapeutic agents, which leading to shortened patient survival. The detailed molecular mechanisms contributing to pancreatic cancer drug resistance remain largely unclear. The growing evidences have shown that noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are involved in pancreatic cancer pathogenesis and development of drug resistance. In the present review, we systematically summarized the new insight on of various miRNAs, lncRNAs and circRNAs on drug resistance of pancreatic cancer. These results demonstrated that targeting the tumor-specific ncRNA may provide novel options for pancreatic cancer treatments.

Regulation of autophagy gene expression and its implications in cancer

Autophagy is a catabolic cellular process that targets and eliminates superfluous cytoplasmic components via lysosomal degradation. This evolutionarily conserved process is tightly regulated at multiple levels as it is critical for the maintenance of homeostasis. Research in the past decade has established that dysregulation of autophagy plays a major role in various diseases, such as cancer and neurodegeneration. However, modulation of autophagy as a therapeutic strategy requires identification of key players that can fine tune the induction of autophagy without complete abrogation. In this Review, we summarize the recent discoveries on the mechanism of regulation of ATG (autophagy related) gene expression at the level of transcription, post transcription and translation. Furthermore, we briefly discuss the role of aberrant expression of ATG genes in the context of cancer.

Qingyihuaji Formula promotes apoptosis and autophagy through inhibition of MAPK/ERK and PI3K/Akt/mTOR signaling pathway on pancreatic cancer in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Qingyihuaji Formula (QYHJ), a widely used traditional Chinese medicine (TCM), has been used to treat patients with cancer in China. However, the effect and mechanism of QYHJ on pancreatic ductal adenocarcinoma (PDAC) remains unclear.

AIM OF THE STUDY

This study aimed to explore the roles and evaluate the possible underlying molecular mechanisms of QYHJ and its core component in PDAC using label-free quantitative proteomics in conjunction with network pharmacology-based analysis.

MATERIALS AND METHODS

By screening differentially expressed proteins (DEPs) in proteomics and QYHJ-predicted gene sets, we identified QYHJ-related PDAC targets annotated with bioinformatic analysis. A subcutaneous tumor model was established to assess the role of QYHJ in vivo. The effects of quercetin (Que), a core component of QYHJ, on cell proliferation, migration, invasion, apoptosis, and autophagy in SW1990 and PANC-1 cells were investigated in vitro. Immunohistochemistry, western blotting, mRFP-GFP-LC3 adenovirus, and kinase analysis were used to determine the underlying mechanisms.

RESULTS

Bioinformatics analysis revealed that 41 QYHJ-related PDAC targets were closely related to the cellular response to nitrogen compounds, positive regulation of cell death, regulation of epithelial cell apoptotic processes, and chemokine signaling pathways. CASP3, SRC, STAT1, PTPN11, PKM, and PAK1 with high expression were identified as hub DEPs in the PPI network, and these DEPs were associated with poor overall survival and STAT 1, MAPK/ERK, and PI3K/Akt/mTOR signaling pathways in PDAC patients. QYHJ significantly promoted tumor death in nude mice. Moreover, quercetin inhibited the proliferation, migration, and invasion of PDAC cells. Additionally, Que induced apoptosis and autophagy in PDAC cells. Mechanistically, QYHJ and Que significantly activated STAT 1 and remarkably inhibited the MAPK/ERK and PI3K/Akt/mTOR signaling pathways in vivo and in vitro, respectively. Importantly, ERK1/2 inactivation contributes to que-induced apoptosis in SW1990 and PANC-1 cells.

CONCLUSIONS

These results suggest that QYHJ and Que are promising anti-PDAC avenues that benefit from their multiform mechanisms.

Autophagy as a self-digestion signal in human cancers: Regulation by microRNAs in affecting carcinogenesis and therapy response

Autophagy is defined as a "self-digestion" signal, and it is a cell death mechanism its primary function is degrading toxic agents and aged organelles to ensure homeostasis in cells. The basic leve ls of autophagy are found in cells, and when its levels exceed to standard threshold, cell death induction is observed. Autophagy dysregulation in cancer has been well-documented, and regulation of this pathway by epigenetic factors, especially microRNAs (miRNAs), is interesting and noteworthy. miRNAs are considered short endogenous RNAs that do not encode functional proteins, and they are essential regulators of cell death pathways such as apoptosis, necroptosis, and autophagy. Accumulating data has revealed miRNA dysregulation (upregulation or downregulation) during tumor progression, and their therapeutic manipulation provides new insight into cancer therapy. miRNA/autophagy axis in human cancers has been investigated an exciting point is the dual function of both autophagy and miRNAs as oncogenic and onco-suppressor factors. The stimulation of pro-survival autophagy by miRNAs can increase the survival rate of tumor cells and mediates cancer metastasis via EMT inductionFurthermore, pro-death autophagy induction by miRNAs has a negative impact on the viability of tumor cells and decreases their survival rate. The miRNA/autophagy axis functions beyond regulating the growth and invasion of tumor cells, and they can also affect drug resistance and radio-resistance. These subjects are covered in the current review regarding the new updates provided by recent experiments.

Epigenetic regulation of autophagy by non-coding RNAs in gastrointestinal tumors: Biological functions and therapeutic perspectives

Cancer is the manifestation of changes and mutations in genetic and epigenetic levels. Non-coding RNAs (ncRNAs) are commonly dysregulated in disease pathogenesis, and their role in cancer has been well-documented. The ncRNAs regulate various molecular pathways and mechanisms in cancer that can lead to induction/inhibition of carcinogenesis. Autophagy is a molecular "self-digestion" mechanism its function can be pro-survival or pro-death in tumor cells. The aim of the present review is to evaluate the role of ncRNAs in regulating autophagy in gastrointestinal tumors. The role of the ncRNA/autophagy axis in affecting the progression of gastric, liver, colorectal, pancreatic, esophageal, and gallbladder cancers is investigated. Both ncRNAs and autophagy mechanisms can function as oncogenic or onco-suppressor and this interaction can determine the growth, invasion, and therapy response of gastrointestinal tumors. ncRNA/autophagy axis can reduce/increase the proliferation of gastrointestinal tumors via the glycolysis mechanism. Furthermore, related molecular pathways of metastasis, such as EMT and MMPs, are affected by the ncRNA/autophagy axis. The response of gastrointestinal tumors to chemotherapy and radiotherapy can be suppressed by pro-survival autophagy, and ncRNAs are essential regulators of this mechanism. miRNAs can regulate related genes and proteins of autophagy, such as ATGs and Beclin-1. Furthermore, lncRNAs and circRNAs down-regulate miRNA expression via sponging to modulate the autophagy mechanism. Moreover, anti-cancer agents can affect the expression level of ncRNAs regulating autophagy in gastrointestinal tumors. Therefore, translating these findings into clinics can improve the prognosis of patients.

MicroRNAs and long non-coding RNAs in pancreatic cancer: From epigenetics to potential clinical applications

MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two relevant classes of non-coding RNAs (ncRNAs) that play a pivotal role in a number of molecular processes through different epigenetic regulatory mechanisms of gene expression. As a matter of fact, the altered expression of these types of RNAs leads to the development and progression of a varied range of multifactorial human diseases. Several recent reports elucidated that miRNA and lncRNAs have been implicated in pancreatic cancer (PC). For instance, dysregulation of such ncRNAs has been found to be associated with chemoresistance, apoptosis, autophagy, cell differentiation, tumor suppression, tumor growth, cancer cell proliferation, migration, and invasion in PC. Moreover, several aberrantly expressed miRNAs and lncRNAs have the potential to be used as biomarkers for accurate PC diagnosis. Additionally, miRNAs and lncRNAs are considered as promising clinical targets for PC. Therefore, in this review, we discuss recent experimental evidence regarding the clinical implications of miRNAs and lncRNAs in the pathophysiology of PC, their future potential, as well as the challenges that have arisen in this field of study in order to drive forward the design of ncRNA-based diagnostics and therapeutics for PC.

Autophagy-Related ncRNAs in Pancreatic Cancer

Pancreatic cancer (PC) is a malignancy accounting for only 3% of total cancers, but with a low 5-year relative survival rate. Approximately 80% of PC patients are diagnosed at a late stage when the disease has already spread from the primary site. Despite advances in PC treatment, there is an urgently needed for the identification of novel therapeutic strategies for PC, particularly for patients who cannot undergo classical surgery. Autophagy is an evolutionarily conserved process used by cells to adapt to metabolic stress via the degrading or recycling of damaged or unnecessary organelles and cellular components. This process is elevated in PC and, thus, it contributes to the onset, progression, and cancer cell resistance to chemotherapy in pancreatic tumors. Autophagy inhibition has been shown to lead to cancer regression and to increase the sensitivity of pancreatic cells to radiation and chemotherapy. Emerging studies have focused on the roles of non-coding RNAs (ncRNAs), such as miRNAs, long non-coding RNAs, and circular RNAs, in PC development and progression. Furthermore, ncRNAs have been reported as crucial regulators of many biological processes, including autophagy, suggesting that ncRNA-based autophagy targeting methods could be promising novel molecular approaches for specifically reducing autophagic flux, thus improving the management of PC patients. In this review, we briefly summarize the existing studies regarding the role and the regulatory mechanisms of autophagy-related ncRNAs in the context of this cancer.

miR-137 modulates coelomocytes autophagy by targeting Atg13 in the sea cucumber Apostichopus japonicus

MicroRNAs (miRNAs), as important regulators of host immune responses, play an crucial position in the interaction between host and pathogen by inhibiting the target gene's transcriptional and post-transcriptional expression. A well-validated tumor suppressor, Previously, miR-137 was found to be variably expressed in the sick sea cucumber Apostichopus japonicus specimens by high-throughput sequencing. To further investigate the mechanism of miR-137 regulation of SUS, we identified Atg13 from sea cucumber by dual luciferase reporter assay and RACE (designated as AjAtg13) and was able to serve as a target gene for miR-137. The full-length cDNA of AjAtg13 is a 2197 bp fragment containing an ORF (open reading frame) of 1149 bp and encodes a total of 382 amino acid polypeptides with a predicted molecular weight of 41.7 kDa. Further expression profiling analysis showed increased mRNA levels of AjAtg13 and reduced expression levels of miR-137 in LPS-stimulated sea cucumber coelomocytes, hinting that miR-137 may negatively regulate AjAtg13. MiR-137 targets AjAtg13 through binding to the 3'UTR region by dual-luciferase reporter gene analysis. MiR-137 overexpression in coelomocytes repressed the expression of autophagy related genes, such as AjAtg13, AjLC3, at the same time, it significantly inhibited autophagy and reduced the ability to clear Vibrio splendidus. Conversely, inhibition of miR-137 significantly upregulated the expression of AjAtg13, promoted autophagy and increased clearance of V. splendidus. Subsequent interference with AjAtg13 also significantly inhibits autophagy. In summary, our results suggested that miR-137 could promote coelomocytes autophagy to restrict bacterial invasion by aiming at AjAtg13 in pathogen-stimulated sea cucumbers.

Epigenetic regulation of autophagy in gastrointestinal cancers

The development of novel therapeutic approaches is necessary to manage gastrointestinal cancers (GICs). Considering the effective molecular mechanisms involved in tumor growth, the therapeutic response is pivotal in this process. Autophagy is a highly conserved catabolic process that acts as a double-edged sword in tumorigenesis and tumor inhibition in a context-dependent manner. Depending on the stage of malignancy and cellular origin of the tumor, autophagy might result in cancer cell survival or death during the GICs' progression. Moreover, autophagy can prevent the progression of GIC in the early stages but leads to chemoresistance in advanced stages. Therefore, targeting specific arms of autophagy could be a promising strategy in the prevention of chemoresistance and treatment of GIC. It has been revealed that autophagy is a cytoplasmic event that is subject to transcriptional and epigenetic regulation inside the nucleus. The effect of epigenetic regulation (including DNA methylation, histone modification, and expression of non-coding RNAs (ncRNAs) in cellular fate is still not completely understood. Recent findings have indicated that epigenetic alterations can modify several genes and modulators, eventually leading to inhibition or promotion of autophagy in different cancer stages, and mediating chemoresistance or chemosensitivity. The current review focuses on the links between autophagy and epigenetics in GICs and discusses: 1) How autophagy and epigenetics are linked in GICs, by considering different epigenetic mechanisms; 2) how epigenetics may be involved in the alteration of cancer-related phenotypes, including cell proliferation, invasion, and migration; and 3) how epidrugs modulate autophagy in GICs to overcome chemoresistance.

Association between microRNAs and chemoresistance in pancreatic cancer: Current knowledge, new insights, and forthcoming perspectives

Pancreatic duct adenocarcinoma, commonly known as pancreatic cancer (PC), is a cancer-related cause of death due to delayed diagnosis, metastasis, and drug resistance. Patients with PC suffer from incorrect responses to chemotherapy due to inherent and acquired chemical resistance. Numerous studies have shown the mechanism of the effect of chemoresistance on PC, such as genetic and epigenetic changes or the elucidation of signaling pathways. In this regard, microRNAs (miRNAs) have been identified as essential modulators of gene expression in various cellular functions, including chemoresistance. Thus, identifying the underlying link between microRNAs and PC chemoresistance helps determine the exact pathogenesis of PC. This study aims to classify miRNAs and signaling pathways related to PC chemoresistance, suggesting new therapeutic approaches to overcome PC chemoresistance.

Meta analysis of bioactive compounds, miRNA, siRNA and cell death regulators as sensitizers to doxorubicin induced chemoresistance

Cancer has presented to be the most challenging disease, contributing to one in six mortalities worldwide. The current treatment regimen involves multiple rounds of chemotherapy administration, alone or in combination. The treatment has adverse effects including cardiomyopathy, hepatotoxicity, and nephrotoxicity. In addition, the development of resistance to chemo has been attributed to cancer relapse and low patient overall survivability. Multiple drug resistance development may be through numerous factors such as up-regulation of drug transporters, drug inactivation, alteration of drug targets and drug degradation. Doxorubicin is a widely used first line chemotherapeutic drug for a myriad of cancers. It has multiple intracellular targets, DNA intercalation, adduct formation, topoisomerase inhibition, iron chelation, reactive oxygen species generation and promotes immune mediated clearance of the tumor. Agents that can sensitize the resistant cancer cells to the chemotherapeutic drug are currently the focus to improve the clinical efficiency of cancer therapy. This review summarizes the recent 10-year research on the use of natural phytochemicals, inhibitors of apoptosis and autophagy, miRNAs, siRNAs and nanoformulations being investigated for doxorubicin chemosensitization.

Non-coding RNAs associated with autophagy and their regulatory role in cancer therapeutics

Cancer widely affects the world's health population and ranks second leading cause of death globally. Because of poor prognosis of various types of cancer such as sarcoma, lymphoma, adenomas etc., their high recurrence and metastasis rate and low early diagnosis rate have become concern lately. Role of autophagy in cancer progression is being studied since long. Autophagy is cell's self-degradative mechanism towards stress and has role in degradation of the cytoplasmic macromolecules which has potential to damage other cytosolic molecules. Autophagy can promote as well as inhibit tumorigenesis depending upon the associated protein combinations in cancer cells. Recent studies have shown that non-coding RNAs (ncRNAs) do not code for protein but play essential role in modulation of gene expression. At transcriptional level, different ncRNAs like lncRNAs, miRNAs and circRNAs directly or indirectly affect different stages of autophagy like autophagy-dependent and non-apoptotic cell death in cancer cells. This review focuses on the involvement of ncRNAs in autophagy and the modulation of several cancer signal transduction pathways in cancers such as lung, breast, prostate, pancreatic, thyroid, and kidney cancer.

Emerging Nanotherapeutic Approaches to Overcome Drug Resistance in Cancers with Update on Clinical Trials

A key issue with modern cancer treatments is the emergence of resistance to conventional chemotherapy and molecularly targeted medicines. Cancer nanotherapeutics were created in order to overcome the inherent limitations of traditional chemotherapeutics. Over the last few decades, cancer nanotherapeutics provided unparalleled opportunities to understand and overcome drug resistance through clinical assessment of rationally designed nanoparticulate delivery systems. In this context, various design strategies such as passive targeting, active targeting, nano-drug, and multimodal nano-drug combination therapy provided effective cancer treatment. Even though cancer nanotherapy has made great technological progress, tumor biology complexity and heterogeneity and a lack of comprehensive knowledge of nano-bio interactions remain important roadblocks to future clinical translation and commercialization. The current developments and advancements in cancer nanotherapeutics employing a wide variety of nanomaterial-based platforms to overcome cancer treatment resistance are discussed in this article. There is also a review of various nanotherapeutics-based approaches to cancer therapy, including targeting strategies for the tumor microenvironment and its components, advanced delivery systems for specific targeting of cancer stem cells (CSC), as well as exosomes for delivery strategies, and an update on clinical trials. Finally, challenges and the future perspective of the cancer nanotherapeutics to reverse cancer drug resistance are discussed.

The Role of Non-Coding RNAs in Autophagy During Carcinogenesis

Macroautophagy (autophagy herein) is a cellular stress response and a survival pathway involved in self-renewal and quality control processes to maintain cellular homeostasis. The alteration of autophagy has been implicated in numerous diseases such as cancer where it plays a dual role. Autophagy serves as a tumor suppressor in the early phases of cancer formation with the restoration of homeostasis and eliminating cellular altered constituents, yet in later phases, autophagy may support and/or facilitate tumor growth, metastasis and may contribute to treatment resistance. Key components of autophagy interact with either pro- and anti-apoptotic factors regulating the proximity of tumor cells to apoptotic cliff promoting cell survival. Autophagy is regulated by key cell signaling pathways such as Akt (protein kinase B, PKB), mammalian target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) involved in cell survival and metabolism. The expression of critical members of upstream cell signaling, as well as those directly involved in the autophagic and apoptotic machineries are regulated by microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Consequently, non-coding RNAs play a relevant role in carcinogenesis and treatment response in cancer. The review is an update of the current knowledge in the regulation by miRNA and lncRNA of the autophagic components and their functional impact to provide an integrated and comprehensive regulatory network of autophagy in cancer.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

BCL2A1 and CCL18 Are Predictive Biomarkers of Cisplatin Chemotherapy and Immunotherapy in Colon Cancer Patients

Background: Cisplatin enhances the antitumor T cell response, and the combination of PD-L1 blockade produces a synergistic therapeutic effect. However, the clinical correlation between cisplatin and immunotherapy in colon cancer (CC) is unknown.

Methods: Using the “pRRophetic” package, we calculated the IC50 of cisplatin. The correlation between cisplatin IC50, cisplatin resistance–related genes (CCL18 and BCL2A1), and immunotherapy were preliminarily verified in TCGA and further validated in independent cohorts (GSE39582 and GSE17538), cisplatin-resistant CC cell line DLD1, and our own clinical specimens. Classification performance was evaluated using the AUC value of the ROC curve. Scores of immune signatures, autophagy, ferroptosis, and stemness were quantified using the ssGSEA algorithm.

Results: Based on respective medians of three CC cohorts, patients were divided into high- and low-IC50 groups. Compared with the high IC50 group, the low-IC50 group had significantly higher tumor microenvironment (TME) scores and lower tumor purity. Most co-signaling molecules were upregulated in low IC50 group. CC patients with good immunotherapy efficacy (MSI, dMMR, and more TMB) were more attributable to the low-IC50 group. Among seven shared differentially expressed cisplatin resistance–related genes, CCL18 and BCL2A1 had the best predictive efficacy of the above immunotherapy biomarkers. For wet experimental verification, compared with cisplatin-resistant DLD1, similar to PD-L1, CCL18 and BCL2A1 were significantly upregulated in wild-type DLD1. In our own CC tissues, the mRNA expression of CCL18, BCL2A1, and PD-L1 in dMMR were significantly increased. The high group of CCL18 or BCL2A1 had a higher proportion of MSI, dMMR, and more TMB. IC50, CCL18, BCL2A1, and PD-L1 were closely related to scores of immune-related pathways, immune signatures, autophagy, ferroptosis, and stemness. The microRNA shared by BCL2A1 and PD-L1, hsa-miR-137, were significantly associated with CCL18, BCL2A1, and PD-L1, and downregulated in low-IC50 group. The activity of the TOLL-like receptor signaling pathway affected the sensitivity of CC patients to cisplatin and immunotherapy. For subtype analysis, immune C2, immune C6, HM-indel, HM-SNV, C18, and C20 were equally sensitive to cisplatin chemotherapy and immunotherapy.

Conclusions: CC patients sensitive to cisplatin chemotherapy were also sensitive to immunotherapy. CCL18 and BCL2A1 were novel biomarkers for cisplatin and immunotherapy.

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.

Potential Therapeutic Action of Autophagy in Gastric Cancer Managements: Novel Treatment Strategies and Pharmacological Interventions

Gastric cancer (GC), second most leading cause of cancer-associated mortality globally, is the cancer of gastrointestinal tract in which malignant cells form in lining of the stomach, resulting in indigestion, pain, and stomach discomfort. Autophagy is an intracellular system in which misfolded, aggregated, and damaged proteins, as well as organelles, are degraded by the lysosomal pathway, and avoiding abnormal accumulation of huge quantities of harmful cellular constituents. However, the exact molecular mechanism of autophagy-mediated GC management has not been clearly elucidated. Here, we emphasized the role of autophagy in the modulation and development of GC transformation in addition to underlying the molecular mechanisms of autophagy-mediated regulation of GC. Accumulating evidences have revealed that targeting autophagy by small molecule activators or inhibitors has become one of the greatest auspicious approaches for GC managements. Particularly, it has been verified that phytochemicals play an important role in treatment as well as prevention of GC. However, use of combination therapies of autophagy modulators in order to overcome the drug resistance through GC treatment will provide novel opportunities to develop promising GC therapeutic approaches. In addition, investigations of the pathophysiological mechanism of GC with potential challenges are urgently needed, as well as limitations of the modulation of autophagy-mediated therapeutic strategies. Therefore, in this review, we would like to deliver an existing standard molecular treatment strategy focusing on the relationship between chemotherapeutic drugs and autophagy, which will help to improve the current treatments of GC patients.

The Role of Autophagy in Childhood Central Nervous System Tumors

OPINION STATEMENT

Autophagy is a physiological process that occurs in normal tissues. Under external environmental pressure or internal environmental changes, cells can digest part of their contents through autophagy in order to reduce metabolic pressure or remove damaged organelles. In cancer, autophagy plays a paradoxical role, acting as a tumor suppressor-by removing damaged organelles and inhibiting inflammation or by promoting genome stability and the tumor-adaptive responses-as a pro-survival mechanism to protect cells from stress. In this article, we review the autophagy-dependent mechanisms driving childhood central nervous system tumor cell death, malignancy invasion, chemosensitivity, and radiosensitivity. Autophagy inhibitors and inducers have been developed, and encouraging results have been achieved in autophagy modulation, suggesting that these might be potential therapeutic agents for the treatment of pediatric central nervous system (CNS) tumors.

Non-coding RNAs as new autophagy regulators in cancer progression

Recent advances highlight that non-coding RNAs (ncRNAs) are emerging as fundamental regulators in various physiological as well as pathological processes by regulating macro-autophagy. Studies have disclosed that macro-autophagy, which is a highly conserved process involving cellular nutrients, components, and recycling of organelles, can be either selective or non-selective and ncRNAs show their regulation on selective autophagy as well as non-selective autophagy. The abnormal expression of ncRNAs will result in the impairment of autophagy and contribute to carcinogenesis and cancer progression by regulating both selective autophagy as well as non-selective autophagy. This review focuses on the regulatory roles of ncRNAs in autophagy and their involvement in cancer which may provide valuable therapeutic targets for cancer management.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

Up-regulation of microRNA miR-101-3p enhances sensitivity to cisplatin via regulation of small interfering RNA (siRNA) Anti-human AGT4D and autophagy in non-small-cell lung carcinoma (NSCLC)

The emergence of drug resistance hinders the treatment of malignant tumors, and autophagy plays an important role in tumor chemotherapy resistance. However, its mechanism in non-small cell lung cancer (NSCLC) has not been well-researched. We aim to investigate the role of miR-101-3p in cisplatin-resistant via regulation of autophagy-related protein 4D (ATG4D) and autophagy. Cell viability, apoptosis, fluorescence intensity of GFP-LC3 and RFP-GFP-LC3 were determined using Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and Laser scanning confocal microscope analysis, respectively. The levels of LC3II/LC3I, P62 and ATG4D were detected by Western blot. The results showed that the sensitivity to cisplatin in NSCLC cells was up-regulated by miR-101-3p mimics treatment, inducing promoting cell apoptosis and inhibiting autophagy. Further mechanistic study identified that ATG4D was a direct target of miR-101-3p. Moreover, ATG4D siRNA also could reverse miR-101-3p inhibitor-induced the up-regulation of ATG4D and the ration of LC3II/LC3I, the down-regulation of p62 expression. Our findings indicated that miR-101-3p could regulate sensitivity to cisplatin of NSNCC cells by regulating autophagy mediated by ATG4D. Therefore, miR-101-3p may act as a potential therapeutic target for the treatment of NSCLC.

Establishment and validation of five autophagy-related signatures for predicting survival and immune microenvironment in glioma

BACKGROUND

Gliomas, especially Glioblastoma multiforme, are the most frequent type of primary tumors in central nervous system. Increasing researches have revealed the relationship between autophagy and tumor, while the molecular mechanism of autophagy in glioma is still rarely reported.

OBJECTIVE

Our research aims to conform the autophagy-related genes (ARGs) implicated in the development and progression of glioma and improve our understanding of autophagy in glioma.

METHODS

20 candidate ARGs were screened through the protein-protein interaction network. We also downloaded the publicly accessible glioma data for 665 individuals from TCGA and 970 individuals from CGGA with RNA sequences and clinicopathological information. Subsequently, univariate and multivariate Cox regression analysis identified 5 key ARGs among the 20 candidate genes as key prognostic genes for survival, GSEA and immune response analysis.

RESULTS

ATG5, BCL2L1, CASP3, CASP8, GAPDH were identified as key ARGs in our research. Further studies showed that the high-risk population was linked to a dismal prognosis and suggested an immune-inhibitory microenvironment. GSEA results demonstrated that high risk population was closely related to DNA repair, hypoxia pathways, implicated in immunosuppression and carcinogenesis. Through CMap, we finally identified 14 candidate drugs for the ARG high risk population.

CONCLUSIONS

This study established and verified an ARG risk model, which can serve as an independent predictor for prognosis, reflect on the strength of the immune response and predict the potential drugs in glioma. Our findings offer new understandings of ARG molecular mechanism and promising therapeutic targets for glioma treatment.

The Role of microRNA in Pancreatic Cancer

MicroRNAs (miRNAs) are small ribonucleic acid molecules that play a key role in regulating gene expression. The increasing number of studies undertaken on the functioning of microRNAs in the tumor formation clearly indicates their important potential in oncological therapy. Pancreatic cancer is one of the deadliest cancers. The expression of miRNAs released into the bloodstream appears to be a good indicator of progression and evaluation of the aggressiveness of pancreatic cancer, as indicated by studies. The work reviewed the latest literature on the importance of miRNAs for pancreatic cancer development.

The role of autophagy in pancreatic cancer progression

Patients with pancreatic cancer have an abysmal survival rate. The poor prognosis of pancreatic cancer is due to the difficulty of making an early diagnosis, high rate of metastasis, and frequent chemoresistance. In recent years, as a self-regulatory procedure within cells, the effect and mechanism of autophagy have been explored. Dysregulated autophagy serves as a double-edged sword in cancer development in which autophagy inhibits cancer initiation but promotes cancer progression. After tumor formation, activation of autophagy can induce epithelial-mesenchymal transition, regulate metabolism, specifically glutamine usage and the glycolytic process, and mediate drug resistance in pancreatic cancer. Multiple genes, RNA molecules, proteins, and certain drugs exert antitumor effects by inhibiting autophagy-mediated drug resistance. Several clinical trials have combined autophagy inhibitors with chemotherapeutic drugs in pancreatic cancer treatment, some of which have shown promising results. In conclusion, autophagy plays a vital role in pancreatic cancer progression and deserves further study.

Epigenetic regulation of autophagy: A key modification in cancer cells and cancer stem cells

Aberrant epigenetic alterations play a decisive role in cancer initiation and propagation via the regulation of key tumor suppressor genes and oncogenes or by modulation of essential signaling pathways. Autophagy is a highly regulated mechanism required for the recycling and degradation of surplus and damaged cytoplasmic constituents in a lysosome dependent manner. In cancer, autophagy has a divergent role. For instance, autophagy elicits tumor promoting functions by facilitating metabolic adaption and plasticity in cancer stem cells (CSCs) and cancer cells. Moreover, autophagy exerts pro-survival mechanisms to these cancerous cells by influencing survival, dormancy, immunosurveillance, invasion, metastasis, and resistance to anti-cancer therapies. In addition, recent studies have demonstrated that various tumor suppressor genes and oncogenes involved in autophagy, are tightly regulated via different epigenetic modifications, such as DNA methylation, histone modifications and non-coding RNAs. The impact of epigenetic regulation of autophagy in cancer cells and CSCs is not well-understood. Therefore, uncovering the complex mechanism of epigenetic regulation of autophagy provides an opportunity to improve and discover novel cancer therapeutics. Subsequently, this would aid in improving clinical outcome for cancer patients. In this review, we provide a comprehensive overview of the existing knowledge available on epigenetic regulation of autophagy and its importance in the maintenance and homeostasis of CSCs and cancer cells.

Facing Cell Autophagy in Gastric Cancer - What Do We Know so Far?

Autophagy is a process by which misfolded proteins and damaged organelles in the lysosomes of tumor cells were degraded reusing decomposed substances and avoiding accumulation of large amounts of harmful substances. Here, the role of autophagy in the development of malignant transformation of gastric tumors, and the underlying mechanisms involved in autophagy formation, and the application of targeted autophagy in the treatment of gastric cancer were summarized.

Noncoding RNAs Associated with Therapeutic Resistance in Pancreatic Cancer

Therapeutic resistance is an inevitable impediment towards effective cancer therapies. Evidence accumulated has shown that the signaling pathways and related factors are fundamentally responsible for therapeutic resistance via regulating diverse cellular events, such as epithelial-to-mesenchymal transition (EMT), stemness, cell survival/apoptosis, autophagy, etcetera. Noncoding RNAs (ncRNAs) have been identified as essential cellular components in gene regulation. The expression of ncRNAs is altered in cancer, and dysregulated ncRNAs participate in gene regulatory networks in pathological contexts. An in-depth understanding of molecular mechanisms underlying the modulation of therapeutic resistance is required to refine therapeutic benefits. This review presents an overview of the recent evidence concerning the role of human ncRNAs in therapeutic resistance, together with the feasibility of ncRNAs as therapeutic targets in pancreatic cancer.

Mitochondrial quality surveillance as a therapeutic target in myocardial infarction

Myocardial infarction (MI) is a leading cause of morbidity and mortality worldwide. As mitochondrial dysfunction critically contributes to the pathogenesis of MI, intensive research is focused on the development of therapeutic strategies targeting mitochondrial homeostasis. Mitochondria possess a quality control system which maintains and restores their structure and function by regulating mitochondrial fission, fusion, biogenesis, degradation and death. In response to slight damage such as transient hypoxia or mild oxidative stress, mitochondrial metabolism shifts from oxidative phosphorylation to glycolysis, in order to reduce oxygen consumption and maintain ATP output. Mitochondrial dynamics are also activated to modify mitochondrial shape and structure, in order to meet cardiomyocyte energy requirements through augmenting or reducing mitochondrial mass. When damaged mitochondria cannot be repaired, poorly structured mitochondria will be degraded through mitophagy, a process which is often accompanied by mitochondrial biogenesis. Once the insult is severe enough to induce lethal damage in the mitochondria and the cell, mitochondrial death pathway activation is an inevitable consequence, and the cardiomyocyte apoptosis or necrosis program will be initiated to remove damaged cells. Mitochondrial quality surveillance is a hierarchical system preserving mitochondrial function and defending cardiomyocytes against stress. A failure of this system has been regarded as one of the potential pathologies underlying MI. In this review, we discuss the recent findings focusing on the role of mitochondrial quality surveillance in MI, and highlight the available therapeutic approaches targeting mitochondrial quality surveillance during MI.

Autophagy Paradox of Cancer: Role, Regulation, and Duality

Autophagy, a catabolic process, degrades damaged and defective cellular materials through lysosomes, thus working as a recycling mechanism of the cell. It is an evolutionarily conserved and highly regulated process that plays an important role in maintaining cellular homeostasis. Autophagy is constitutively active at the basal level; however, it gets enhanced to meet cellular needs in various stress conditions. The process involves various autophagy-related genes that ultimately lead to the degradation of targeted cytosolic substrates. Many factors modulate both upstream and downstream autophagy pathways like nutritional status, energy level, growth factors, hypoxic conditions, and localization of p53. Any problem in executing autophagy can lead to various pathological conditions including neurodegeneration, aging, and cancer. In cancer, autophagy plays a contradictory role; it inhibits the formation of tumors, whereas, during advanced stages, autophagy promotes tumor progression. Besides, autophagy protects the tumor from various therapies by providing recycled nutrition and energy to the tumor cells. Autophagy is stimulated by tumor suppressor proteins, whereas it gets inhibited by oncogenes. Due to its dynamic and dual role in the pathogenesis of cancer, autophagy provides promising opportunities in developing novel and effective cancer therapies along with managing chemoresistant cancers. In this article, we summarize different strategies that can modulate autophagy in cancer to overcome the major obstacle, i.e., resistance developed in cancer to anticancer therapies.

Negative Regulation of ULK1 by microRNA-106a in Autophagy Induced by a Triple Drug Combination in Colorectal Cancer Cells In Vitro

Colorectal cancer (CRC) is among the top three most deadly cancers worldwide. The survival rate for this disease has not been reduced despite the treatments, the reason why the search for therapeutic alternatives continues to be a priority issue in oncology. In this research work, we tested our successful pharmacological combination of three drugs, metformin, doxorubicin, and sodium oxamate (triple therapy, or TT), as an autophagy inducer. Firstly, we employed western blot (WB) assays, where we observed that after 8 h of stimulation with TT, the proteins Unc-51 like autophagy activating kinase 1(ULK1), becline-1, autophagy related 1 protein (Atg4), and LC3 increased in the CRC cell lines HCT116 and SW480 in contrast to monotherapy with doxorubicin. The overexpression of these proteins indicated the beginning of autophagy flow through the activation of ULK1 and the hyperlipidation of LC3 at the beginning of this process. Moreover, we confirm that ULK1 is a bona fide target of hsa-miR-106a-5p (referred to from here on as miR-106a) in HCT116. We also observed through the GFP-LC3 fusion protein that in the presence of miR-106a, the accumulation of autophagy vesicles in cells stimulated with TT is inhibited. These results show that the TT triggered autophagy to modulate miR-106a/ULK1 expression, probably affecting different cellular pathways involved in cellular proliferation, survivance, metabolic maintenance, and cell death. Therefore, considering the importance of autophagy in cancer biology, the study of miRNAs that regulate autophagy in cancer will allow a better understanding of malignant tumors and lead to the development of new disease markers and therapeutic strategies.

Daurisoline inhibits hepatocellular carcinoma progression by restraining autophagy and promoting cispaltin-induced cell death

Hepatocellular carcinoma (HCC) is a common malignancy with high cancer-associated mortality. Suppressing autophagy has been reported to promote the efficiency of chemotherapy in HCC. Daurisoline (DAS) is a constituent of Rhizoma Menispermi, and functions as a potential autophagy inhibitor to perform different cellular events. In the present study, we found that DAS treatment up-regulated autophagosomes in HCC cells, accompanied with the increases of LC3-II and p62, demonstrating the disturbance of autophagic flux. Then, by the colocalization analysis, we identified that DAS did not repress the fusion of autophagosomes and lysosomes in HCC cells. However, Lysotracker and acridine orange (OA) staining showed that DAS could suppress lysosomal acidification, as evidenced by the decreased red fluorescence. Consistently, significant decreases in mature form of cathepsin B and cathepsin D were detected in DAS-treated HCC cells. Furthermore, DAS treatment markedly promoted the anti-cancer effects of cisplatin (cDDP) on HCC cells, as revealed by the dramatically reduced cell viability and proliferation, whereas the enhanced apoptosis. Moreover, the nude mice xenograft models with HCC confirmed that compared with cDDP alone group, DAS combined with cDDP significantly reduced tumor progression in vivo. Taken together, these findings elucidated that DAS could restrain autophagic flux, potentiating the chemosensitivity of HCC cells to cDDP treatment.

Noncoding RNAs in drug-resistant pancreatic cancer: A review

Pancreatic cancer is the fourth-leading cause of cancer-related deaths and is expected to be the second-leading cause of cancer-related deaths in Europe and the United States by 2030. The high fatality rate of pancreatic cancer is ascribed to untimely diagnosis, early metastasis and limited responses to both chemotherapy and radiotherapy. Although gemcitabine, 5-fluorouracil and some other drugs can profoundly improve patient prognosis, most pancreatic cancer patients eventually develop drug resistance, leading to poor clinical outcomes. The underlying mechanisms of pancreatic cancer drug resistance are complicated and inconclusive. Interestingly, accumulating evidence has demonstrated that different noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), play a crucial role in pancreatic cancer resistance to chemotherapy reagents. In this paper, we systematically summarize the molecular mechanism underlying the influence of ncRNAs on the generation and development of drug resistance in pancreatic cancer and discuss the potential role of ncRNAs as prognostic markers and new therapeutic targets for pancreatic cancer.

Apigenin as Tumor Suppressor in Cancers: Biotherapeutic Activity, Nanodelivery, and Mechanisms With Emphasis on Pancreatic Cancer

Pancreatic cancer is the most lethal malignancy of the gastrointestinal tract. Due to its propensity for early local and distant spread, affected patients possess extremely poor prognosis. Currently applied treatments are not effective enough to eradicate all cancer cells, and minimize their migration. Besides, these treatments are associated with adverse effects on normal cells and organs. These therapies are not able to increase the overall survival rate of patients; hence, finding novel adjuvants or alternatives is so essential. Up to now, medicinal herbs were utilized for therapeutic goals. Herbal-based medicine, as traditional biotherapeutics, were employed for cancer treatment. Of them, apigenin, as a bioactive flavonoid that possesses numerous biological properties (e.g., anti-inflammatory and anti-oxidant effects), has shown substantial anticancer activity. It seems that apigenin is capable of suppressing the proliferation of cancer cells via the induction of cell cycle arrest and apoptosis. Besides, apigenin inhibits metastasis via down-regulation of matrix metalloproteinases and the Akt signaling pathway. In pancreatic cancer cells, apigenin sensitizes cells in chemotherapy, and affects molecular pathways such as the hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1). Herein, the biotherapeutic activity of apigenin and its mechanisms toward cancer cells are presented in the current review to shed some light on anti-tumor activity of apigenin in different cancers, with an emphasis on pancreatic cancer.

miRNA-based biomarkers, therapies, and resistance in Cancer

MicroRNAs (miRNAs), small non-coding RNAs (ncRNAs) of about 22 nucleotides in size, play important roles in gene regulation, and their dysregulation is implicated in human diseases including cancer. A variety of miRNAs could take roles in the cancer progression, participate in the process of tumor immune, and function with miRNA sponges. During the last two decades, the connection between miRNAs and various cancers has been widely researched. Based on evidence about miRNA, numerous potential cancer biomarkers for the diagnosis and prognosis have been put forward, providing a new perspective on cancer screening. Besides, there are several miRNA-based therapies among different cancers being conducted, advanced treatments such as the combination of synergistic strategies and the use of complementary miRNAs provide significant clinical benefits to cancer patients potentially. Furthermore, it is demonstrated that many miRNAs are engaged in the resistance of cancer therapies with their complex underlying regulatory mechanisms, whose comprehensive cognition can help clinicians and improve patient prognosis. With the belief that studies about miRNAs in human cancer would have great clinical implications, we attempt to summarize the current situation and potential development prospects in this review.

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.

Targeting the MicroRNA-490-3p-ATG4B-Autophagy Axis Relieves Myocardial Injury in Ischemia Reperfusion

We investigated the potential role of miR-490-3p in ischemia reperfusion (IR) injury. We first determined the expression of miR-490-3p and autophagy-related 4B cysteine (ATG4B) in IR. Then, to explore whether miR-490-3p would affect autophagy, apoptosis, and IR injury, we evaluated apoptosis, autophagy, and infarct size via gain- and loss-of-function experiments. Furthermore, we used adenovirus to enhance or inhibit the expression of ATG4B, and then measured autophagy, apoptosis, and IR injury. miR-490-3p was downregulated in the hearts during the process of IR, while ATG4B was upregulated. The inhibition of miR-490-3p or overexpression of ATG4B could promote the expression of LC3II, increase the autolysosomes, inhibit the expression of p62, and reduce infarct size. On all accounts, the inhibition of miR-490-3p could promote autophagy to reduce myocardial IR injury by upregulating ATG4B, a finding that provides new insights for the protective mechanism of autophagy in IR. Graphical Abstract.

Long noncoding RNA OIP5-AS1 mediates resistance to doxorubicin by regulating miR-137-3p/PTN axis in osteosarcoma

Opa-interacting protein 5 antisense RNA1 (OIP5-AS1) has been demonstrated to facilitate proliferation, metastasis and resistance to treatments in various types of cancers. Nevertheless, the exact mechanisms underlying the roles of OIP5-AS1 in osteosarcoma(OS) drug resistance have not yet been clearly elucidated. Therefore, we sought to investigate the functional involvement of OIP5-AS1 in osteosarcoma. Our results indicated that OIP5-AS1 was dramatically up-regulated in osteosarcoma drug-resistant tissues and cells in comparison with drug-sensitive tissues and cells. Also, the knockdown of OIP5-AS1 was found to have decreased doxorubicin resistance of OS cells. Further analyses revealed that OIP5-AS1 operated as a competitor for endogenous RNA of miR-137-3p as well as regulated pleiotrophin(PTN) expression, which has been reported to be an oncogene in OS in previous research. Furthermore, the loss of miR-137-3p or alternatively, the gain of PTN, both resulted in the abolishment of the inhibitory role of OIP5-AS1 silencing the proliferative activity. Our analyses indicated and helped to determine the role of OIP5-AS1 in contributing to tumorigenesis of osteosarcoma via the miR-137-3p/PTN axis and, therefore outlining its potential for use as a therapeutic target against this cancer.