MiR-361-5p suppresses chemoresistance of gastric cancer cells by targeting FOXM1 via the PI3K/Akt/mTOR pathway

MicroRNA-532-3p Modulates Colorectal Cancer Cell Proliferation and Invasion via Suppression of FOXM1

Colorectal cancer (CRC) is a heterogeneous disease and classified into various subtypes, among which transcriptional alterations result in CRC progression, metastasis, and drug resistance. Forkhead-box M1 (FOXM1) is a proliferation-associated transcription factor which is overexpressed in CRC and the mechanisms of FOXM1 regulation have been under investigation. Previously, we showed that FOXM1 binds to promoters of certain microRNAs. Database mining led to several microRNAs that might interact with FOXM1 3'UTR. The interactions between shortlisted microRNAs and FOXM1 3'UTR were quantitated by a dual-luciferase reporter assay. MicroRNA-532-3p interacted with the 3'UTR of the FOXM1 mRNA transcript most efficiently. MicroRNA-532-3p was ectopically overexpressed in colorectal cancer (CRC) cell lines, leading to reduced transcript and protein levels of FOXM1 and cyclin B1, a direct transcriptional target of FOXM1. Further, a clonogenic assay was conducted in overexpressed miR-532-3p CRC cells that revealed a decline in the ability of cells to form colonies and a reduction in migratory and invading potential. These alterations were reinforced at molecular levels by the altered transcript and protein levels of the conventional EMT markers E-cadherin and vimentin. Overall, this study identifies the regulation of FOXM1 by microRNA-532-3p via its interaction with FOXM1 3'UTR, resulting in the suppression of proliferation, migration, and invasion, suggesting its role as a tumor suppressor in CRC.

Navigating the autophagic landscape: Epigenetic modulation in gastrointestinal cancer

This editorial comments on the manuscript by Chang et al, focusing on the still elusive interplay between epigenetic regulation and autophagy in gastrointestinal diseases, particularly cancer. Autophagy, essential for cellular homeostasis, exhibits diverse functions ranging from cell survival to death, and is particularly implicated in physiological gastrointestinal cell functions. However, its role in pathological backgrounds remains intricate and context-dependent. Studies underscore the dual nature of autophagy in cancer, where its early suppressive effects in early stages are juxtaposed with its later promotion, contributing to chemoresistance. This discrepancy is attributed to the dysregulation of autophagy-related genes and their intricate involvement in cellular processes. Epigenetic modifications and regulations of gene expression, including non-coding RNAs (ncRNAs), emerge as critical players in exerting regulatory control over autophagy flux, influencing treatment responses and tumor progression. Targeting epigenetic mechanisms and improving strategies involving the inhibition or induction of autophagy through pharmacological or genetic means present potential avenues to sensitize tumor cells to chemotherapy. Additionally, nanocarrier-based delivery of ncRNAs offers innovative therapeutic approaches. Understanding the intricate interaction between autophagy and ncRNA regulation opens avenues for the development of targeted therapies, thereby improving the prognosis of gastrointestinal malignancies with poor outcomes.

The role of microRNAs in the gastric cancer tumor microenvironment

BACKGROUND

Gastric cancer (GC) is one of the deadliest malignant tumors with unknown pathogenesis. Due to its treatment resistance, high recurrence rate, and lack of reliable early detection techniques, a majority of patients have a poor prognosis. Therefore, identifying new tumor biomarkers and therapeutic targets is essential. This review aims to provide fresh insights into enhancing the prognosis of patients with GC by summarizing the processes through which microRNAs (miRNAs) regulate the tumor microenvironment (TME) and highlighting their critical role in the TME.

MAIN TEXT

A comprehensive literature review was conducted by focusing on the interactions among tumor cells, extracellular matrix, blood vessels, cancer-associated fibroblasts, and immune cells within the GC TME. The role of noncoding RNAs, known as miRNAs, in modulating the TME through various signaling pathways, cytokines, growth factors, and exosomes was specifically examined. Tumor formation, metastasis, and therapy in GC are significantly influenced by interactions within the TME. miRNAs regulate tumor progression by modulating these interactions through multiple signaling pathways, cytokines, growth factors, and exosomes. Dysregulation of miRNAs affects critical cellular processes such as cell proliferation, differentiation, angiogenesis, metastasis, and treatment resistance, contributing to the pathogenesis of GC.

CONCLUSIONS

miRNAs play a crucial role in the regulation of the GC TME, influencing tumor progression and patient prognosis. By understanding the mechanisms through which miRNAs control the TME, potential biomarkers and therapeutic targets can be identified to improve the prognosis of patients with GC.

HOMER3 promotes liver hepatocellular carcinoma cancer progression by -upregulating EZH2 and mediating miR-361/GPNMB axis

Liver hepatocellular carcinoma (LIHC) is among the most lethal human cancers. Studies have shown that Homer scaffold protein 3 (HOMER3) plays important roles in various diseases and cancers, but its biological function and molecular mechanism in LIHC have never been investigated. Our study discovered the aberrantly high expression of HOMER3 and its promising diagnostic and prognostic significance in LIHC. Functionally, HOMER3 knockdown inhibited the proliferative and migrative abilities of LIHC cells and tumor growth in vivo. Mechanically, HOMER3 mediated the aggressiveness of LIHC cells via GPNMB. Meanwhile, miR-361 directly targeted GPNMB and attenuated LIHC progression by suppressing GPNMB expression. The regulatory effect of HOMER3 during LIHC progression was exerted through the miR-361/GPNMB axis. Furthermore, EZH2 supplementation or miR-361 depletion effectively abated the tumor-suppressive effect of HOMER3 knockdown on LIHC progression. In conclusion, HOMER3 mediated LIHC progression through the EZH2/miR-361/GPNMB axis.

Abnormal expression of FOXM1 in carcinogenesis of renal cell carcinoma: From experimental findings to clinical applications

Renal cell carcinoma (RCC) is a prevalent malignancy within the genitourinary system. At present, patients with high-grade or advanced RCC continue to have a bleak prognosis. Mounting research have emphasized the significant involvement of Forkhead box M1 (FOXM1) in RCC development and progression. Therefore, it is imperative to consolidate the existing evidence regarding the contributions of FOXM1 to RCC tumorigenesis through a comprehensive review. This study elucidated the essential functions of FOXM1 in promoting RCC growth, invasion, and metastasis by regulating cell cycle progression, DNA repair, angiogenesis, and epithelial-mesenchymal transition (EMT). Also, FOXM1 might serve as a novel diagnostic and prognostic biomarker as well as a therapeutic target for RCC. Clinical findings demonstrated that the expression of FOXM1 was markedly upregulated in RCC samples, while a high level of FOXM1 was found to be associated with a poor overall survival rate of RCC. Furthermore, it is worth noting that FOXM1 may have a significant impact on the resistance of renal cell carcinoma (RCC) to radiotherapy. This observation suggests that inhibiting FOXM1 could be a promising strategy to impede the progression of RCC and enhance its sensitivity to radiotherapy. The present review highlighted the pivotal role of FOXM1 in RCC development. FOXM1 has the capacity to emerge as not only a valuable diagnostic and prognostic tool but also a viable therapeutic option for unresectable RCC.

CDK12 Promotes the Proliferation, Migration, and Angiogenesis of Gastric Carcinoma via Activating the PI3K/AKT/mTOR Signaling Pathway

Cyclin-dependent kinase 12 (CDK12) has been found to regulate tumor progression. However, its function in gastric carcinoma (GC) remains controversial. This work aimed to explore the exact effect of CDK12 on GC progression. We detected the expression of CDK12 in GC cells and normal gastric mucosal epithelial cells. Then CDK12 function on GC cell proliferation, migration, and angiogenesis was researched by colony formation experiment, Transwell experiment, and angiogenesis assay. Moreover, CDK12 effect on the PI3K/AKT/mTOR pathway activity was explored by western blot. Further, we used LY294002 (10 μM) to treat GC cells to verify whether CDK12 regulates GC progression by activating the PI3K/AKT/mTOR pathway. Additionally, CDK12 effect on the expression of prognostic factors of GC was detected by western blot, including alkaline phosphatase (ALP) and Ki67. Quantitative real-time polymerase chain reaction and western blot were utilized to evaluate the expression of mRNAs and proteins. As a result, CDK12 was upregulated in GC cells. CDK12 overexpression facilitated the proliferation, migration, and angiogenesis of GC cells. However, CDK12 silencing showed an opposite result. CDK12 overexpression activated the PI3K/AKT/mTOR pathway, but CDK12 silencing inactivated it in GC cells. The blockage of the PI3K/AKT/mTOR pathway induced by LY294002 treatment counteracted the promotion of CDK12 on the proliferation, migration, and angiogenesis of GC. Further, CDK12 silencing suppressed the expression of ALP and Ki67 proteins in GC cells. Taken together, CDK12 promotes the proliferation, migration, and angiogenesis of GC by activating the PI3K/AKT/mTOR pathway. It may be a novel target for GC treatment.

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.

LncRNA PRKCQ-AS1 regulates paclitaxel resistance in triple-negative breast cancer cells through miR-361-5p/PIK3C3 mediated autophagy

Paclitaxel (PTX) resistance is a key cause of chemotherapy failure in patients with triple negative breast cancer (TNBC). The aim of this study is to investigate the effect and mechanism of long non-coding RNA (lncRNA) on the PTX resistance of TNBC cells through autophagy. MDA-MB-231 cells are used to induce the PTX-resistant TNBC cell line MDA-MB-231.PR (MDR) by increasing dose intermittently. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the mRNA levels of phosphoinositide-3-kinase class 3 (PIK3C3), miR-361-5p and lncRNA PRKCQ-AS1 in the cells, and Western blot analysis was used to detect the protein expressions of PIK3C3, autophagy-related, drug-resistant and apoptosis-related genes. MDC staining detected the formation of autophagic vacuoles. The interactions between miR-361-5p and PIK3C3 and between lncRNA PRKCQ-AS1 and miR-361-5p were verified by dual-luciferase assay. Cell viability, apoptosis, migration and invasion were assessed by performing MTT, flow cytometry assay, and transwell assay. The mRNA level of miR-361-5p and the autophagy and drug resistance levels of TNBC PTX-resistant cells were significantly up-regulated. miR-361-5p could target autophagy-related gene PIK3C3, and overexpression of miR-361-5p could down-regulate PIK3C3 protein expression and autophagy level and PTX resistance of MDR cells. LncRNA PRKCQ-AS1 was selected through bioanalysis, and miR-361-5p could target lncRNA PRKCQ-AS1. In addition, lncRNA PRKCQ-AS1 level was up-regulated in TNBC PTX-resistant cells, and knockdown of lncRNA PRKCQ-AS1 could weaken autophagy and drug resistance level and could promote cell apoptosis. Overexpression of lncRNA PRKCQ-AS1 reversed the pro-apoptotic effect and down-regulation of autophagy and resistance levels was induced by miR-361-5p. In vivo experiments were performed to verify the role of lncRNA PRKCQ-AS1. We demonstrate that down-regulation of lncRNA PRKCQ-AS1 weakened PTX resistance and promoted cell apoptosis by miR-361-5p/PIK3C3 mediated autophagy.

Bioactive triterpenes of jujube in the prevention of colorectal cancer and their molecular mechanism research

BACKGROUND

Jujube, a popular fruit from the Rhamnaceae family, relieves colorectal inflammation caused by spleen deficiency and has been used in many formulas in clinical for decades to treat colorectal cancer (CRC). As of yet, the therapeutic substances and mechanism of their action are unknown.

PURPOSE

The purpose of this study is to define the therapeutic substances of jujube and its mechanism of action in treating CRC.

METHODS

The pharmacological effects of jujube extract and its fractions were evaluated in vivo using a CRC mouse model induced by AOM/DSS. The DAI value, colon length, mortality, tumor burden, and histological tumor size of the treated animals were compared. To explore the potential therapeutic substances, LC-MS analysis was conducted to characterize the serum migration components. A network pharmacology experiment was carried out for potential molecular targets. To verify the therapeutic substances as well as the molecular mechanism of jujube intervening CRC, cellular MTT assay of the serum migration components, Western blot and IHC tests were conducted.

RESULTS

The in vivo pharmacological studies showed that compared to AOM/DSS treated mice, the mortality and DAI value, tumor burden, and histological tumor size of jujube extract and its fat-soluble fraction (mainly contained triterpenes) treated mice were significantly reduced, and their colon lengths were obviously longer than AOM/DSS treated mice. The targeted-LC/MS analysis supposed triterpenes 3, 7, 9, 11, 12, 14, 17 - 21, and 25 - 28 to be the serum migration components, which might be the potential therapeutic substances. In the network pharmacology experiment, the GO annotation and enrichment analysis of the KEGG pathway indicated that PI3K-Akt pathway and inflammatory reaction were important factors for jujube inhibiting CRC. Cellular MTT assay of serum migration components indicated that the potential effective substances from fat-soluble fraction to be triterpenes 3, 7, 17, 19, 20, and 25. The Western blot and IHC assays implied that the jujube extract, its fat-soluble fraction, and triterpenes 7, 17, and 20 showed inhibition on the expression of PI3K/Akt/NF-κB signaling pathway-related proteins. Additionally, it was noted in the pharmacodynamic experiment that ZJL's effectiveness was more apparent than ZJH and SQL in tumor burden rate, colon length, and spleen weight, which indicated that the efficacy of ZJ is contributed from CD and SQ, and they may have a synergistic effect on anti-CRC.

CONCLUSION

These results for the first time provide evidence that jujube triterpenes possess an anti-CRC effect, their mechanism was involving the control of the PI3K/Akt/NF-κB signaling pathway. What's more, the potential synergistic effect of the fat-soluble and water-soluble components found in this study provided a solid foundation for our deep understanding of how jujube can ameliorate CRC.

A Water-Soluble Hydrogen Sulfide Donor Suppresses the Growth of Hepatocellular Carcinoma via Inhibiting the AKT/GSK-3β/β-Catenin and TGF-β/Smad2/3 Signaling Pathways

Hepatocellular carcinoma (HCC) is a disease with high morbidity, high mortality, and low cure rate. Hyaluronic acid (HA) is widely adopted in tissue engineering and drug delivery. 5-(4-Hydroxyphenyl)-3H-1, 2-dithiol-3-thione (ADT-OH) is one of commonly used H₂S donors. In our previous study, HA-ADT was designed and synthesized via coupling of HA and ADT-OH. In this study, compared with sodium hydrosulfide (NaHS, a fast H₂S-releasing donor) and morpholin-4-ium (4-methoxyphenyl)-morpholin-4-ylsulfanylidenesulfido-λ5-phosphane (GYY4137, a slow H₂S-releasing donor), HA-ADT showed stronger inhibitory effect on the proliferation, migration, invasion, and cell cycle of human HCC cells. HA-ADT promoted apoptosis by suppressing the expressions of phospho (p)-protein kinase B (PKB/AKT), p-glycogen synthase kinase-3β (GSK-3β), p-β-catenin, and also inhibited autophagy via the downregulation of the protein levels of p-Smad2, p-Smad3, and transforming growth factor-β (TGF-β) in human HCC cells. Moreover, HA-ADT inhibited HCC xenograft tumor growth more effectively than both NaHS and GYY4137. Therefore, HA-ADT can suppress the growth of HCC cells by blocking the AKT/GSK-3β/β-catenin and TGF-β/Smad2/3 signaling pathways. HA-ADT and its derivatives may be developed as promising antitumor drugs.

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.

Predicting and Validating the Mechanism of Qingyi II Granules in the Treatment of Acute Pancreatitis by Network Pharmacology

Network pharmacology, reverse molecular docking, and rat acute pancreatitis (AP) models were used to analyze the mechanism of protection by Qingyi II granules. The chemical components of 7 Chinese herbal medicines in Qingyi II granules were searched through the TCMSP (traditional Chinese medicine systems pharmacology database and analysis platform) database. The active ingredients were screened out in the OB (oral bioavailability) and DL (drug likeness) filters as a condition for inclusion. Then, the prediction analysis of potential targets was performed through databases. A GO (gene ontology) enrichment analysis of target proteins related to AP and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway annotation was performed using the DAVID (The Database for Annotation, Visualization, and Integrated Discovery) database. Finally, the “Herbal-Compound-Target” network was constructed using Cytoscape software. The active component structure and target name were uploaded to the Systems Dock database for reverse molecular docking. With octreotide as a positive control, Qingyi II decoction and Qingyi II granules were administered to AP rats at low, medium, and high doses. The pathological changes in the pancreas were observed using HE staining. The levels of Bcl-2, AMS, BAX, IL-2, and CASP3 in plasma were determined by an ELISA kit. Real-time PCR detected the expression of AKT1 and PIK3CA mRNA in the pancreas. The database predicted 94 active components of Qingyi II granules, 76 potential targets, and 64 signaling pathways. Twenty pathways were directly or indirectly associated with acute pancreatitis, including the TNF signaling pathway and the PI3K-AKT signaling pathway. In the reverse molecular docking experiment, the matching scores of the active components and the target were mainly between 6.0 and 7.0, with strong binding activity. Compared to the normal group, the plasma concentrations of BAX, IL-2, Bcl-2, AMS, and CASP3 in the model group were significantly increased ( $P<0.05$ ). Compared with the model group, the low-dose group of Qingyi II granules only significantly reduced IL-2 levels and had no effect on other indicators. The other groups could significantly reduce the levels of AMS, BAX, and CASP3 ( $P<0.05$ ). Compared with the model group, the octreotide group and Qingyi II granules high-dose group significantly increased the Bcl-2 level ( $P<0.05$ ), and there was no statistical difference in other drug-administered groups. Compared with the normal group, the expression of AKT1 and PIK3CA in the pancreas of the model group was significantly higher. Compared to the model group, the expression of PIK3CA was low in all drug-administered groups. In addition to the low-dose group, the other drug-administered groups significantly reduced the expression of AKT1. Qingyi can reduce the levels of AMS, BAX, IL-2, and CASP3 and increase the levels of Bcl-2. This mechanism may be related to the PI3K- AKT signaling pathway.

Regulation of autophagy by non-coding RNAs in gastric cancer

Autophagy is a conserved cellular self-digesting process that degrades obsoleting proteins and cellular components and plays a crucial role in the tumorigenesis, metastasis, and drug resistance of various tumors such as gastric cancer (GC). As a hotspot in molecular biology, non-coding RNAs (ncRNAs) are involved in the regulation of multiple biological processes, such as autophagy. Increasing evidence indicate that various ncRNAs exert double roles in the initiation and progression of GC, either serve as oncogenes or tumor suppressors. Recent studies have shown that some ncRNAs could modulate autophagy activity in GC cells, which would affect the malignant transformation and drug resistance. Whether the function of ncRNAs in GC is dependent on autophagy is undefined. Therefore, identifying the underlying moleculr targets of ncRNAs in autophagy pathways and the role of ncRNA-regulated autophagy in GC could develop new treatment interventions for this disease. This review summarizes the autophagy process and its role in GC, and the regulatory mechanisms of ncRNAs, as well as focuses on the dual role of ncRNAs-mediated autophagy in GC, for the development of potential therapeutic strategies in GC patients.

ALDH1A3–Linc00284 Axis Mediates the Invasion of Colorectal Cancer by Targeting TGFβ Signaling via Sponging miR-361-5p

ALDH1A3 and Linc00284 involve in colorectal cancer (CRC) development; however, the regulatory mechanism is still unclear. In this study, we collected clinicopathological characteristics and tissue samples from 73 CRC patients to analyze the expression of ALDH1A3, Linc00284, TGFβ signaling and miR-361-5p using qPCR, Western blotting, and ELISA. Multiple CRC cell lines were evaluated in this study, and the highest level of ALDH1A3 was observed in SW480 cells. To investigate the regulatory mechanism, RIP and luciferase assays were used to validate the interaction between Linc00284, miR-361-5p, and TGFβ. Proliferation, viability, migration, and invasion assays were performed to profile the effects of the ALDH1A3–Linc00284 axis in CRC cell functions, which was upregulated in CRC tissues. Knockdown ALDH1A3 or Linc00284 significantly reduced TGFβ expression and suppressed the EMT process, while overexpression had opposite effects. miR-361-5p targeted TGFβ directly, which negatively correlated with ALDH1A3–Linc00284 expression and CRC progression. Mechanistically, upregulation of ALDH1A3–Linc00284 promotes colorectal cancer invasion and migration by regulating miR-361-5p/TGFβ signaling pathway. Dysregulation of the ALDH1A3–Linc00284-miR-361-5p-TGFβ axis causes CRC invasion, which might provide a new insight into the treatment of CRC.

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.

Circular RNA circ_0006089 promotes the progression of gastric cancer by regulating the miR-143-3p/PTBP3 axis and PI3K/AKT signaling pathway

OBJECTIVES

Circular RNAs (circRNAs) play pivotal roles in malignancies including gastric cancer (GC). We aimed to investigate the biological function and regulatory mechanism of circ_0006089 in GC.

METHODS

Circ_0006089, microRNA (miR)-143-3p, and polypyrimidine tract-binding protein 3 (PTBP3) expressions were measured via quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in GC cell lines. Cell proliferative capacity was determined by colony formation and CCK-8 assays. Flow cytometry was employed for measuring cell apoptosis. Cell invasion and migration were measured via transwell and wound-healing assays. Western blot analysis was utilized for detecting protein expressions of E-cadherin, N-cadherin, vimentin, PTBP3, PI3K, p-PI3K, AKT, and p-AKT. Dual-reporter luciferase analysis was conducted to confirm the association between miR-143-3p and circ_0006089 or PTBP3. The role of circ_0006089 in vivo was detected via establishing a mice xenograft model.

RESULTS

Circ_0006089 expression was increased in GC. Circ_0006089 downregulation suppressed the proliferation and metastasis and induced apoptosis of GC cells, which was counteracted by miR-143-3p inhibition or PTBP3 overexpression. In addition, circ_0006089 overexpression could promote GC progression. MiR-143-3p specially bound to circ_0006089 and PTBP3 was targeted by miR-143-3p. Moreover, circ_0006089 could regulate PTBP3 expression and the PI3K/AKT pathway by sponging miR-143-3p. Circ_0006089 knockdown also suppressed tumor growth.

CONCLUSION

Circ_0006089 regulated miR-143-3p/PTBP3/PI3K/AKT pathway to facilitate GC progression.

Noncoding RNAs and hyperthermic intraperitoneal chemotherapy in advanced gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors globally. About 20-30% of patients with gastric cancer show peritoneal implantation metastasis at the first diagnosis. Peritoneal metastasis is responsible for 70% of deaths of patients with advanced gastric cancer. Although there are many ways to treat advanced gastric cancer, the prognosis of patients with recurrence is unsatisfactory. An auxiliary treatment with hyperthermic intraperitoneal chemotherapy (HIPEC), is an internationally recognized recommended treatment for advanced gastric cancer. A series of clinical trials have shown that HIPEC significantly improves the overall survival of patients with cancer. Compared with the cytoreductive surgery (CRS) alone, HIPEC combined with CRS markedly reduced the rate of peritoneal metastasis in patients with ovarian cancer and colorectal cancer. It has been demonstrated that HIPEC alters transcription of many genes by affecting non-coding RNAs, which may contribute to the suppressive effect of HIPEC on the synthesis of nucleic acids and proteins in cancer cells. This paper reviews the recent advances in understanding the role of non-coding RNAs in tumor invasion and metastasis of advanced gastric cancer. We also consider changes in noncoding RNA levels and other molecules in advanced gastric cancer cases treated with HIPEC. We hope that our review will provide a reference for future research on molecular epidemiology and etiology of advanced gastric cancer and promote precise treatment of this malignancy using HIPEC.

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 Implication of Autophagy in Gastric Cancer Progression

Gastric cancer is the fifth most common malignancy and the third leading cause of cancer-related death worldwide. The three entirely variable entities have distinct epidemiology, molecular characteristics, prognosis, and strategies for clinical management. However, many gastric tumors appear to be resistant to current chemotherapeutic agents. Moreover, a significant number of gastric cancer patients, with a lack of optimal treatment strategies, have reduced survival. In recent years, multiple research data have highlighted the importance of autophagy, an essential catabolic process of cytoplasmic component digestion, in cancer. The role of autophagy as a tumor suppressor or tumor promoter mechanism remains controversial. The multistep nature of the autophagy process offers a wide array of targetable points for designing novel chemotherapeutic strategies. The purpose of this review is to summarize the current knowledge regarding the interplay between gastric cancer development and the autophagy process and decipher the role of autophagy in this kind of cancer. A plethora of different agents that direct or indirect target autophagy may be a novel therapeutic approach for gastric cancer patients.

Effect of Eriodictyol on Retinoblastoma via the PI3K/Akt Pathway

Retinoblastoma (RB) is one of the most common intraocular malignancies in children, which causes vision loss and even threatens life. Eriodictyol is a natural flavonoid with strong anticancer activity. Some studies have shown that eriodictyol exerts anticancer effects in glioma, colon cancer, and lung cancer; however, no studies have reported the anticancer effects of eriodictyol on RB. Therefore, the aim of this study was to investigate the anticancer activity of eriodictyol against the RB Y79 cell line and its potential mechanism of action. Interestingly, we found that eriodictyol inhibited the proliferation, migration, and invasion of Y79 cells in a dose-dependent manner and decreased the expression of MMP-2 and MMP-9 proteins in the cells. In addition, eriodictyol-induced apoptosis in Y79 cells was assessed by flow cytometry and immunoblotting. Here, our study revealed that eriodictyol dose dependently inhibited the activation of the PI3K/Akt signaling pathway. Notably, the effect of eriodictyol on RB apoptosis was reversed by a PI3K agonist 740 Y-P. In conclusion, our study shows that eriodictyol effectively inhibits proliferation, migration, and invasion and induces apoptosis in RB cell lines, which may be the result of blocking the PI3K/Akt signaling pathway. Thus, eriodictyol may provide a new theoretical basis for exploring targeted antitumor natural therapies.

microRNA-877-5p exerts tumor-suppressive functions in prostate cancer through repressing transcription of forkhead box M1

The study aimed to investigate the significant potential role of miR-877-5p in Prostate cancer. The expression levels of miR-877-5p and forkhead box M1 (FOXM1) mRNA were detected by qRT-PCR. The prognostic significance of miR-877-5p in prostate cancer was investigated using Kaplan Meier analysis. Then, Cell Counting Kit-8 (CCK-8) and transwell assay were used to evaluate the effects of miR-877-5p on cell biological functions. The mechanism of miR-877-5p action on prostate cancer cells was investigated by luciferase activity assay with wide-type or mutation. miR-877-5p was lowly expressed both in prostate cancer tissues and cell lines compared with corresponding normal counterparts. Further, miR-877-5p was significantly correlated with Gleason score and TNM stage. Moreover, miR-877-5p may serve as an independent prognostic predictor. In addition, FOXM1 was checked as a direct target gene of miR-877-5p, and miR-877-5p can inhibit the expression of FOXM1 to restrain the growth, migration, and invasion abilities of prostate cancer cells. Taken together, miR-877-5p may act as a suppressor in prostate cancer and reduces cancer cell proliferation, migration and invasion by targeting FOXM1. miR-877-5p may serve as the effective biomarkers and therapeutic target for treating prostate cancer patients.

A YAP/FOXM1 axis mediates EMT-associated EGFR inhibitor resistance and increased expression of spindle assembly checkpoint components

Acquired resistance to tyrosine kinase inhibitors (TKIs) of epidermal growth factor receptor (EGFR) remains a clinical challenge. Especially challenging are cases in which resistance emerges through EGFR-independent mechanisms, such as through pathways that promote epithelial-to-mesenchymal transition (EMT). Through an integrated transcriptomic, proteomic, and drug screening approach, we identified activation of the yes-associated protein (YAP) and forkhead box protein M1 (FOXM1) axis as a driver of EMT-associated EGFR TKI resistance. EGFR inhibitor resistance was associated with broad multidrug resistance that extended across multiple chemotherapeutic and targeted agents, consistent with the difficulty of effectively treating resistant disease. EGFR TKI-resistant cells displayed increased abundance of spindle assembly checkpoint (SAC) proteins, including polo-like kinase 1 (PLK1), Aurora kinases, survivin, and kinesin spindle protein (KSP). Moreover, EGFR TKI-resistant cells exhibited vulnerability to SAC inhibitors. Increased activation of the YAP/FOXM1 axis mediated an increase in the abundance of SAC components in resistant cells. The clinical relevance of these finding was indicated by evaluation of specimens from patients with EGFR mutant lung cancer, which showed that high FOXM1 expression correlated with expression of genes encoding SAC proteins and was associated with a worse clinical outcome. These data revealed the YAP/FOXM1 axis as a central regulator of EMT-associated EGFR TKI resistance and that this pathway, along with SAC components, are therapeutic vulnerabilities for targeting this multidrug-resistant phenotype.

The Interaction of GLUT1 and FOXM1 Leads to a Poor Prognosis in Colorectal Cancer

BACKGROUND

Colorectal Cancer (CRC) is one of the most common fatal diseases with high morbidity. Alteration of glucose metabolism is one of the hallmarks in the development of CRC. Glucose Transporter 1 (GLUT1) is a key rate-limiting protein in hyperactive glucose metabolism and up-regulated in CRC, however, the underlying mechanism of the altered metabolism in CRC is still unknown.

METHODS

In this study, immunohistochemical staining was used to evaluate the expression of GLUT1 and FOXM1 in 135 paired CRC and adjacent normal tissues. The association between the expression of GLUT1/FOXM1 and clinicopathological factors was determined and the correlation between GLUT1 and FOXM1 in CRC was investigated.

RESULTS

Our results revealed that regardless of tumor location, GLUT1 and FOXM1 were overexpressed in CRC tissues, especially in patients with positive lymph node metastasis and TNM stage III-IV. Furthermore, GLUT1 showed a significantly strong link with FOXM1 in CRC tissue.

CONCLUSION

Overexpression of GLUT1 and FOXM1 may play critical roles in CRC leading to a poor prognosis.

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.

MicroRNAs in the regulation of autophagy and their possible use in age-related macular degeneration therapy

Age-related macular degeneration (AMD) is a progressive sight-impairing disease of the elderly. The pathogenic mechanisms of AMD are not well understood although both genetic and many environmental factors have been associated with the development of AMD. One clinical hallmark of AMD is the detrimental aggregation of damaged proteins. Recently, it has been suggested that the weakening of autophagy clearance is an important mechanism in the pathogenesis of AMD. Autophagy is important in the removal of damaged or no longer needed cellular material and its recycling. A considerable number of autophagy-targeting microRNAs (miRNAs), small RNA molecules and epigenetic regulators have been found to be either up- or down-regulated in AMD patients and experimental models. The important role of autophagy-targeting miRNAs is supported by several studies and can open the prospect of the use of these miRNAs in the therapy for AMD.

TNFAIP8 regulates gastric cancer growth via mTOR-Akt-ULK1 pathway and autophagy signals

In this study, the purpose of this study was to investigate the role of TNFAIP8 in gastric cancer (GC). The expression of TNFAIP8 was detected by RT-PCR or western blot . TNFAIP8 was silenced or overexpressed in two cell lines. CCK-8 assay, transwell assay and flow cytometry were used to analyse cell viability, cell invasion capability and apoptosis, respectively. Nude mice were inoculated with TNFAIP8 silencing or overexpressing cells to form transplanted tumours. HE staining and immunohistochemistry assay were performed to assess histopathological changes in tumours. We found that the mRNA and protein expression of TNFAIP8 were significantly up-regulated in GC tumour tissues and cells compared with the normal counterparts. Overexpression of TNFAIP8 in GC cells increased cell viability, decreased apoptosis and promoted the cell migration ability. Meanwhile, increased expression of TNFAIP8 promoted autophagy, while inhibiting mTOR-Akt-ULK1 signal pathway. In conclusions, this study presents data that TNFAIP8 inhibits GC cells presumably by down-regulating mTOR-Akt-ULK1 signal pathway and activating autophagy signal.

A Systematic Review of MicroRNAs Involved in Cervical Cancer Progression

To obtain a better understanding on the role of microRNAs in the progression of cervical cancer, a systematic review was performed to analyze cervical cancer microRNA studies. We provide an overview of the studies investigating microRNA expression in relation to cervical cancer (CC) progression, highlighting their common outcomes and target gene interactions according to the regulatory pathways. To achieve this, we systematically searched through PubMed MEDLINE, EMBASE, and Google Scholar for all articles between April 2010 and April 2020, in accordance with the PICO acronym (participants, interventions, comparisons, outcomes). From 27 published reports, totaling 1721 cases and 1361 noncancerous control tissue samples, 26 differentially expressed microRNAs (DEmiRNAs) were identified in different International Federation of Gynecology and Obstetrics (FIGO) stages of cervical cancer development. It was identified that some of the dysregulated microRNAs were associated with specific stages of cervical cancer development. The results indicated that DEmiRNAs in different stages of cervical cancer were functionally involved in several key hallmarks of cancer, such as evading growth suppressors, enabling replicative immortality, activation of invasion and metastasis, resisting cell death, and sustained proliferative signaling. These dysregulated microRNAs could play an important role in cervical cancer's development. Some of the stage-specific microRNAs can also be used as biomarkers for cancer classification and monitoring the progression of cervical cancer.

The Role of Autophagy in Gastric Cancer Chemoresistance: Friend or Foe?

Gastric cancer is the third most common cause of cancer-related death worldwide. Drug resistance is the main inevitable and vital factor leading to a low 5-year survival rate for patients with gastric cancer. Autophagy, as a highly conserved homeostatic pathway, is mainly regulated by different proteins and non-coding RNAs (ncRNAs) and plays dual roles in drug resistance of gastric cancer. Thus, targeting key regulatory nodes in the process of autophagy by small molecule inhibitors or activators has become one of the most promising strategies for the treatment of gastric cancer in recent years. In this review, we provide a systematic summary focusing on the relationship between autophagy and chemotherapy resistance in gastric cancer. We comprehensively discuss the roles and molecular mechanisms of multiple proteins and the emerging ncRNAs including miRNAs and lncRNAs in the regulation of autophagy pathways and gastric cancer chemoresistance. We also summarize the regulatory effects of autophagy inhibitor and activators on gastric cancer chemoresistance. Understanding the vital roles of autophagy in gastric cancer chemoresistance will provide novel opportunities to develop promising therapeutic strategies for gastric cancer.

The forkhead box M1 (FOXM1) expression and antitumor effect of FOXM1 inhibition in malignant rhabdoid tumor

PURPOSE

Malignant rhabdoid tumor (MRT) is a rare, highly aggressive sarcoma with an uncertain cell of origin. Despite the existing standard of intensive multimodal therapy, the prognosis of patients with MRT is very poor. Novel antitumor agents are needed for MRT patients. Forkhead box transcription factor 1 (FOXM1) is overexpressed and is correlated with the pathogenesis in several human malignancies. In this study, we identified the clinicopathological and prognostic values of the expression of FOXM1 and its roles in the progression of MRT.

METHODS

We investigated the FOXM1 expression levels and their clinical significance in 23 MRT specimens using immunohistochemistry and performed clinicopathologic and prognostic analyses. We also demonstrated correlations between the downregulation of FOXM1 and oncological characteristics using small interfering RNA (siRNA) and FOXM1 inhibitor in MRT cell lines.

RESULTS

Histopathological analyses revealed that primary renal MRTs showed significantly low FOXM1 protein expression levels (p = 0.032); however, there were no significant differences in other clinicopathological characteristics or the survival rate. FOXM1 siRNA and FOXM1 inhibitor (thiostrepton) successfully downregulated the mRNA and protein expression of FOXM1 in vitro and the downregulation of FOXM1 inhibited cell proliferation, drug resistance to chemotherapeutic agents, migration, invasion, and caused the cell cycle arrest and apoptosis of MRT cell lines. A cDNA microarray analysis showed that FOXM1 regulated FANCD2 and NBS1, which are key genes for DNA damage repair.

CONCLUSION

This study demonstrates that FOXM1 may serve as a promising therapeutic target for MRT.

MicroRNA in Gastric Cancer Development: Mechanisms and Biomarkers

Gastric cancer (GC) is one of the most common and difficult diseases to treat. The study of signaling pathway regulation by microRNA provides information on the mechanisms of GC development and is the basis for biomarker creation. In this study, a circuit of microRNA interactions with signaling pathways was constructed. The microRNAs, associated with metastasis and chemoresistance, are described. In most cases, microRNAs in GC regulate the Wnt/β-catenin, PI3K/AKT/mTOR, RAS/RAF/ERK/MAPK, NF-kB, TGF-β, and JAK/STAT pathways. Part of the microRNA acts on several target genes that function in different pathways. This often leads to an intensification of the induced processes. MicroRNAs have also been described that have the opposite effect on different pathways, causing different functional consequences. By acting on several target genes, or genes associated with several pathways, microRNAs can function in a signaling network. MicroRNAs associated with metastasis most often interact with the Wnt/β-catenin pathway. MicroRNAs affecting chemoresistance, in most cases, affect the regulators of apoptosis and are associated with the PI3K/AKT/mTOR pathway. The characteristics of microRNAs proposed as candidates for GC biomarkers were analyzed. The currently developed diagnostic and prognostic panels of microRNAs are also considered.

MicroRNA-mediated autophagy regulation in cancer therapy: The role in chemoresistance/chemosensitivity

Chemoresistance has doubled the effort needed to reach an effective treatment for cancer. Now, scientists should consider molecular pathways and mechanisms involved in chemoresistance to overcome cancer. Autophagy is a "self-digestion" mechanism in which potentially toxic and aged organelles and macromolecules are degraded. Increasing evidence has shown that autophagy possesses dual role in cancer cells (onco-suppressor or oncogene). So, it is vital to identify its role in cancer progression and malignancy. MicroRNAs (miRs) are epigenetic factors capable of modulation of autophagy in cancer cells. In the current review, we emphasize on the relationship between miRs and autophagy in cancer chemotherapy. Besides, we discuss upstream mediators of miR/autophagy axis in cancer chemotherapy including long non-coding RNAs, circular RNAs, Nrf2 c-Myc, and HIF-1α. At the final section, we provide a discussion about how anti-tumor compounds affect miR/autophagy axis in ensuring chemosensitivity. These topics are described in this review to show how autophagy inhibition/induction can lead to chemosensitivity/chemoresistance, and miRs are considered as key players in these discussions.

Exosome-transferred LINC01559 promotes the progression of gastric cancer via PI3K/AKT signaling pathway

Increasing evidence indicates that long non-coding RNAs (lncRNAs) are associated with the progression of human cancers. However, the expression level and function of LINC01559 (long intergenic non-protein coding RNA 1559) in gastric cancer (GC) are rarely reported. Here we found that LINC01559 was upregulated in GC tissues based on GEPIA (Gene Expression Profiling Interactive Analysis) and TCGA (The Cancer Genome Atlas) databases. Also, LINC01559 was expressed at a lower level in GC cells than in mesenchymal stem cells (MSCs). In vitro experiments revealed that silencing LINC01559 remarkably hindered GC cell proliferation, migration and stemness. Then, we identified that LINC01559 was transmitted form MSCs to GC cells via the exosomes. Immunofluorescence staining and electron microscope validated the existence of exosomes in GC cells. Mechanistically, LINC01559 sponged miR-1343-3p to upregulate PGK1 (phosphoglycerate kinase 1), therefore activating PI3K/AKT pathway. Moreover, LINC01559 recruited EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) to PTEN (phosphatase and tensin homolog) promoter, inducing the methylation of PTEN promoter and finally resulting in PTEN repression. Of note, LINC01559 targeted both PGK1 and PTEN to promote GC progression by activating PI3K/AKT pathway. Taken together, our study demonstrated that LINC01559 accelerated GC progression via upregulating PGK1 and downregulating PTEN to trigger phosphatidylinositol 3-kinase/AKT serine/threonine kinase (PI3K/AKT) pathway, indicating LINC01559 as a potential biomarker for GC treatment.

Identification of hub genes and discovery of promising compounds in gastric cancer based on bioinformatics analysis

Aim: To explore the mechanism of gastric carcinogenesis by mining potential hub genes and to search for promising small-molecular compounds for gastric cancer (GC). Materials & methods: The microarray datasets were downloaded from Gene Expression Omnibus database and the genes and compounds were analyzed by bioinformatics-related tools and software. Results: Six hub genes (MKI67, PLK1, COL1A1, TPX2, COL1A2 and SPP1) related to the prognosis of GC were confirmed to be upregulated in GC and their high expression was correlated with poor overall survival rate in GC patients. In addition, eight candidate compounds with potential anti-GC activity were identified, among which resveratrol was closely correlated with six hub genes. Conclusion: Six hub genes identified in the present study may contribute to a more comprehensive understanding of the mechanism of gastric carcinogenesis and the predicted potential of resveratrol may provide valuable clues for the future development of targeted anti-GC inhibitors.

MicroRNAs in gastric cancer: Biomarkers and therapeutic targets

MicroRNAs (miRNAs) are a group of non-coding RNAs that have critical roles in regulation of expression of genes. They can inhibit or decrease expression of target genes mostly via interaction with 3' untranslated region of their targets. Their crucial roles in the regulation of expression of tumor suppressor genes and oncogenes have potentiated them as contributors in tumorigenesis. Moreover, their stability in body fluids has enhanced their potential as cancer biomarkers. In the present review article, we describe the role of miRNAs in the pathogenesis of gastric cancer and advances in application of miRNAs as biomarkers and therapeutic targets in this kind of malignancy.

The role of epigenetics and non-coding RNAs in autophagy: A new perspective for thorough understanding

Autophagy is a major self-degradative intracellular process required for the maintenance of homeostasis and promotion of survival in response to starvation. It plays critical roles in a large variety of physiological and pathological processes. On the other hand, aberrant regulation of autophagy can lead to various cancers and neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Crohn's disease. Emerging evidence strongly supports that epigenetic signatures, related non-coding RNA profiles, and their cross-talking are significantly associated with the control of autophagic responses. Therefore, it may be helpful and promising to manage autophagic processes by finding valuable markers and therapeutic approaches. Although there is a great deal of information on the components of autophagy in the cytoplasm, the molecular basis of the epigenetic regulation of autophagy has not been completely elucidated. In this review, we highlight recent research on epigenetic changes through the expression of autophagy-related genes (ATGs), which regulate autophagy, DNA methylation, histone modifications as well as non-coding RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and their relationship with human diseases, that play key roles in causing autophagy-related diseases.

MicroRNA-192 promotes the development of nasopharyngeal carcinoma through targeting RB1 and activating PI3K/AKT pathway

BACKGROUND

The dysregulation of microRNAs (miRNAs) has been found in diseases and cancers, including microRNA-192 (miR-192). This study was designed to investigate the role of miR-192 in nasopharyngeal carcinoma (NPC) progression.

METHODS

The expression levels of miR-192 and some genes were assessed by qRT-PCR and Western blot. The function of miR-192 was investigated through MTT, Transwell, and dual-luciferase reporter assays.

RESULTS

The expression of miR-192 was increased in NPC tissues, and high miR-192 expression predicted poor prognosis in NPC patients. Functionally, upregulation of miR-192 promoted NPC cell migration, invasion, and growth. Furthermore, miR-192 activated EMT and PI3K/AKT pathway to regulate NPC progression. In addition, miR-192 directly targeted RB1 and suppressed its expression in NPC. Moreover, overexpression of RB1 weakened the promoted effect of miR-192 in NPC.

CONCLUSION

miR-192 promoted cell viability and metastasis in NPC through suppressing RB1 expression and activating PI3K/AKT pathway.

FOXM1 contributes to docetaxel resistance in castration-resistant prostate cancer by inducing AMPK/mTOR-mediated autophagy

Docetaxel-mediated chemotherapy is the first line therapy for metastatic castration-resistant prostate cancer (CRPC) patients, but its therapeutic benefit is limited by the development of resistance. Although Forkhead box protein M1 (FOXM1) has been implicated in prostate tumorigenesis and metastasis, its role in docetaxel resistance has not been studied. Here, we showed that FOXM1 expression was upregulated in the docetaxel resistant CRPC cell lines (PC3-DR and VCaP-DR) and knockdown of FOXM1 sensitized the cells to docetaxel both in vitro and in vivo. In addition, autophagy was found to be significantly enhanced in resistant cells. Moreover, FOXM1 overexpression cells showed increased autophagic flux and higher numbers of autophagosomes. Knockdown of ATG7, beclin-1 or cotreatment with chloroquine, partly restored sensitivity to docetaxel in the FOXM1-overexpressing cells. Mechanistically, FOXM1 targeted AMPK/mTOR to activate the autophagy pathway and altered docetaxel response in CRPC. These findings identify the role of FOXM1 as well as the mechanism underlying FOXM1 action in docetaxel sensitivity and may, therefore, aid in design of CRPC therapies.

VGLL3 is a prognostic biomarker and correlated with clinical pathologic features and immune infiltrates in stomach adenocarcinoma

Due to its poor clinical outcome, there is an urgent need to identify novel prognostic markers for stomach adenocarcinoma (STAD). Here, we aimed to explore the relationship between VGLL3 expression and clinico-pathological features, dendritic cells, macrophages, and prognosis of STAD. VGLL3 expression levels were significantly associated with histological grade, T stage, and TNM stage. VGLL3 levels and patient’s age were also independent prognostic factors of the clinical outcome of STAD. In addition, VGLL3 was associated with the abundance of macrophages and dendritic cells in tumor infiltrates, of which only VGLL3 and macrophage counts were the independent prognostic factors of immune cell infiltration in the TIMER Database. Extracellular matrix receptor interaction, focal adhesion, pathways in cancer, MAPK, JAK STAT, and WNT signaling pathways were enriched in VGLL3 high-expressing datasets as determined by Gene Set Enrichment Analysis (GSEA), while DNA replication, glyoxylate, and dicarboxylate metabolism, glutathione metabolism, homologous recombination, and glycosylphosphatidylinositol gpi banchor biosynthesis were enriched in VGLL3 low-expressing datasets. Thus, VGLL3 is a novel prognostic biomarker of both the clinical outcome and immune infiltration in STAD, and may therefore be a promising therapeutic target.

Chemotherapeutic Stress Influences Epithelial-Mesenchymal Transition and Stemness in Cancer Stem Cells of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by the absence of estrogen and progesterone receptors (ER, PR) and lacking an overexpression of human epidermal growth factor receptor 2 (HER2). Apart from this lack of therapeutic targets, TNBC also shows an increased capacity for early metastasis and therapy resistance. Currently, many TNBC patients receive neoadjuvant chemotherapy (NACT) upon detection of the disease. With TNBC likely being driven at least in part by a cancer stem-like cell type, we wanted to evaluate the response of primary cancer stem cells (CSCs) to standard chemotherapeutics. Therefore, we set up a survival model using primary CSCs to mimic tumor cells in patients under chemotherapy. Breast cancer stem cells (BCSCs) were exposed to chemotherapeutics with a sublethal dose for six days. Surviving cells were allowed to recover in culture medium without chemotherapeutics. Surviving and recovered cells were examined in regard to proliferation, migratory capacity, sphere forming capacity, epithelial–mesenchymal transition (EMT) factor expression at the mRNA level, and cancer-related microRNA (miRNA) profile. Our results indicate that chemotherapeutic stress enhanced sphere forming capacity of BCSCs, and changed cell morphology and EMT-related gene expression at the mRNA level, whereas the migratory capacity was unaffected. Six miRNAs were identified as potential regulators in this process.

Hsa_circ_CSPP1/MiR-361-5p/ITGB1 Regulates Proliferation and Migration of Cervical Cancer (CC) by Modulating the PI3K-Akt Signaling Pathway

This study aimed to investigate the regulatory mechanism of circular RNA CSPP1 (hsa_circ_CSPP1) in cervical cancer. Based on GEO database, differentially expressed circRNAs and mRNAs related to cervical cancer were screened out by R software. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) term analysis were performed to analyze the functional and pathway enrichment of identified DEGs. In addition, Cytoscape software was used to build interaction network of DEGs. The mRNA expressions were examined by qRT-PCR. Western blot was conducted to view the expression of proteins. Cell proliferation and apoptosis were respectively evaluated using CCK-8 assay and flow cytometry, whereas cell migration abilities were detected by Transwell assay. The relationship among factors was validated by dual-luciferase reporter gene assay. The influence in cervical tumor growth was further verified through nude mouse model in vivo. Hsa_circ_CSPP1 and ITGB1 were high-expressed in cervical cancer, while miR-361-5p was low-expressed. Hsa_circ_CSPP1 knockdown or miR-361-5p overexpression could suppress cervical cancer cell proliferation and migration, whereas promoted cell apoptosis. In addition, further experiments demonstrated that both hsa_circ_CSPP1 and ITGB1 mRNA were targets of miR-361-5p. Repressing hsa_circ_CSPP1 restrained cell viability and mobility and induced apoptosis through sponging miR-361-5p. Meanwhile, miR-361-5p also inhibited cervical cancer tumorigenesis via downregulation of ITGB1. Knockdown of hsa_circ_CSPP1 impeded tumor growth through suppressing the expression of downstream gene ITGB1, PI3K, and Akt. Circular RNA hsa_circ_CSPP1 regulates cell migration and proliferation in cervical cancer through miR-361-5p/ITGB1 in PI3K-Akt signaling pathway.

Protective Role of Astrocyte-Derived Exosomal microRNA-361 in Cerebral Ischemic-Reperfusion Injury by Regulating the AMPK/mTOR Signaling Pathway and Targeting CTSB

BACKGROUND

Evidence has shown that microRNAs (miRNAs) are implicated in ischemic diseases. Therefore, the aim of the present study was to identify the functions of astrocyte (ATC)-derived exosomal miR-361 on cerebral ischemic-reperfusion (I/R) injury.

METHODS

A rat model of cerebral I/R injury was initially established, followed by injection of ATC-derived exosomes. Next, the protective function of ATC-derived exosomes in rats with cerebral I/R injury was evaluated, and then the effect of miR-361 on rats with cerebral I/R injury was evaluated by changing miR-361 expression in exosomes. PC12 cells that underwent oxygen-glucose deprivation/reoxygenation were used to simulate I/R in vitro. The effect of ATC-derived exosomal miR-361 on the viability and apoptosis of OGD/R-treated PC12 cells was also assessed. The bioinformatic analysis predicted the targeted gene of miR-361.

RESULTS

It was found that I/R was damaging to the brain nerves of rats, while ATC-derived exosomal miR-361 relieved nerve damage caused by I/R. Furthermore, the in vitro experiments demonstrated that ATC-derived exosomal miR-361 increased OGD/R-inhibited PC12 cell activity and suppressed cell apoptosis. Bioinformatics predicted that miR-361 targeted cathepsin B (CTSB). CTSB upregulation blocked the protective roles of miR-361. In addition, miR-361 was found to downregulate the AMPK / mTOR signaling pathway by targeting CTSB.

CONCLUSION

The present study demonstrated that ATC-derived exosomal miR-361 alleviates nerve damage in rats with cerebral I/R injury by targeting CTSB and downregulating the AMPK/mTOR pathway. This may offer novel insights into treatment for I/R injury.

MEG3 promotes proliferation and inhibits apoptosis in osteoarthritis chondrocytes by miR-361-5p/FOXO1 axis

Background

This study aimed to investigate the role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) and related molecular mechanisms, in osteoarthritis (OA).

Methods

Cartilage tissues of OA patients and healthy volunteers were isolated and cultured. After transfection with the appropriate constructs, chondrocytes were classified into Blank, pcDNA3.1-NC, pcDNA3.1-MEG3, si-NC, si-MEG3, pcDNA3.1-NC + mimics NC, pcDNA3.1-MEG3 + mimics NC, pcDNA3.1-NC + miR-361-5p mimics and pcDNA3.1-MEG3 + miR-361-5p mimics groups. qRT-PCR was used to detect the expression of MEG3, miR-361-5p and FOXO1. Western blot, luciferase reporter assay, RIP, CCK-8, and flow cytometry analysis were performed to reveal the morphology, proliferation, and apoptotic status of cartilage cells. Histological analysis and immunostaining were conducted in the OA rat model.

Results

Expression of MEG3 and FOXO1 was significantly decreased in OA compared with the normal group, while the expression of miR-361-5p was increased. MEG3 might serve as a ceRNA of miR-361-5p in OA chondrocytes. Moreover, using western blot analyses and the CCK-8 assay, MEG3 was shown to target miR-361-5p/FOXO1, elevate cell proliferation, and impair cell apoptosis. Functional analysis in vivo showed that MEG3 suppressed degradation of the cartilage matrix.

Conclusion

MEG3 can contribute to cell proliferation and inhibit cell apoptosis and degradation of extracellular matrix (ECM) via the miR-361-5p/FOXO1 axis in OA chondrocytes.

Research Progress in microRNA-Based Therapy for Gastric Cancer

Gastric cancer (GC) is one of the leading causes of tumor-related mortality. In addition to surgery and endoscopic resection, systemic therapy remains the main treatment option for GC, especially for advanced-stage disease and for cases not suitable for surgical therapy. Hence, improving the efficacy of systemic therapy is still an urgent problem to overcome. In the past decade, the essential roles of microRNAs (miRNAs) in tumor treatment have been increasingly recognized. In particular, miRNAs were recently shown to reverse the resistance to chemotherapy drugs such as 5-fluorouracil, cisplatin, and doxorubicin. Synthesized nanoparticles loaded with mimics or inhibitors of miRNAs can directly target tumor cells to suppress their growth. Moreover, exosomes may serve as promising safe carriers for mimics or inhibitors of miRNAs to treat GC. Some miRNAs have also been shown to play roles in the mechanism of action of other anti-tumor drugs. Therefore, in this review, we highlight the research progress on microRNA-based therapy in GC and discuss the challenges and prospects associated with this strategy. We believe that microRNA-based therapy has the potential to offer a clinical benefit to GC patients, and this review would contribute to and motivate further research to promote this field toward this ultimate goal.

Knockdown of TOR signaling pathway regulator suppresses cell migration and invasion in non-small cell lung cancer via the regulation of epithelial-to-mesenchymal transition

Non-small cell lung cancer (NSCLC) is one of the most common cancer types worldwide. Previous studies have indicated that TOR signaling pathway regulator (TIPRL) is involved in the progression of NSCLC. However, the underlying mechanisms of the role of TIPRL in regulating NSCLC metastasis have remained largely elusive. In the present study, the expression pattern of TIPRL in NSCLC was analyzed using The Cancer Genome Atlas (TCGA) dataset. Furthermore, Kaplan-Meier curve analysis was performed to evaluate the prognostic value of TIPRL in NSCLC, using the Kaplan-Meier Plotter and TCGA datasets. Loss-of-function assays were performed to determine the effects of TIPRL on cell migration and invasion. The results suggested that TIPRL was upregulated in NSCLC and positively associated with an advanced Tumor-Node-Metastasis stage. A higher expression level of TIPRL was associated with shorter overall and disease-free survival times in patients with NSCLC. To the best of our knowledge, the present study was the first to report that TIPRL acts as a metastasis promoter in NSCLC. Silencing of TIPRL suppressed A549 cell migration and invasion. Mechanistically, the present study indicated that TIPRL knockdown significantly promoted epithelial-cadherin expression, whereas it suppressed twist and vimentin expression in A549 cells. In conclusion, the present analysis suggested that TIPRL may serve as a biomarker for the prognosis of NSCLC and as a future target for its treatment.

METase/lncRNA HULC/FoxM1 reduced cisplatin resistance in gastric cancer by suppressing autophagy

BACKGROUND

Autophagy plays an important role in regulating cisplatin (CDDP) resistance in gastric cancer cells. However, the underlying mechanism of methioninase (METase) in the regulation of autophagy and CDDP resistance of gastric cancer cells is still not clear.

MATERIALS AND METHODS

Western blot was used to detect the levels of autophagy-related proteins, multidrug-resistant 1 (MDR-1), and FoxM1 protein. LncRNA HULC was detected by qRT-PCR. Cell viability was detected using CCK-8 assay. The interaction between lncRNA HULC and FoxM1 was confirmed by RNA pull-down and RIP assay.

RESULTS

Lentiviral vector carrying METase (LV-METase) suppressed autophagy and CDDP resistance of drug-resistant gastric cancer cells. LncRNA HULC was significantly downregulated in drug-resistant gastric cancer cells transfected with LV-METase. Besides, we found that lncRNA HULC interacted with FoxM1. In addition, METase suppressed autophagy to reduce CDDP resistance of drug-resistant gastric cancer cells through regulating HULC/FoxM1, and interfering HULC suppressed autophagy to reduce CDDP resistance of drug-resistant gastric cancer cells through regulating FoxM1. Finally, interfering HULC inhibited tumor growth in vivo.

CONCLUSION

METase suppressed autophagy to reduce CDDP resistance of drug-resistant gastric cancer cells through regulating HULC/FoxM1 pathway.

MicroRNA-361: A Multifaceted Player Regulating Tumor Aggressiveness and Tumor Microenvironment Formation

MicroRNA-361-5p (miR-361) expression frequently decreases or is lost in different types of cancers, and contributes to tumor suppression by repressing the expression of its target genes implicated in tumor growth, epithelial-to-mesenchymal transition (EMT), metastasis, drug resistance, glycolysis, angiogenesis, and inflammation. Here, we review the expression pattern of miR-361 in human tumors, describe the mechanisms responsible for its dysregulation, and discuss how miR-361 modulates the aggressive properties of tumor cells and alter the tumor microenvironment by acting as a novel tumor suppressor. Furthermore, we describe its potentials as a promising diagnostic or prognostic biomarker for cancers and a promising target for therapeutic development.

LncRNA SBF2-AS1 promotes the progression of cervical cancer by regulating miR-361-5p/FOXM1 axis

Long non-coding RNAs (lncRNAs) have been identified as critical players in tumorigenesis. Previous studies revealed that lncRNA SBF2-AS1 was involved in tumor progression. However, the role and underlying mechanism of SBF2-AS1 in cervical cancer (CC) remain unknown. In the present study, our data showed that SBF2-AS1 expression was significantly increased in CC. High SBF2-AS1 expression was associated with advanced FIGO stage and lymph node metastasis of CC patients. Function assays showed that SBF2-AS1 inhibition significantly reduced CC cells proliferation both in vitro and in vivo. Mechanistically, we showed that SBF2-AS1 upregulation restrained the activity of miR-361-5p and led to overexpression of FOXM1 in CC cells. Furthermore, we found that miR-361-5p inhibitors could rescue the effects of SBF2-AS1 inhibition on CC cells proliferation. Taken together, we demonstrated that the SBF2-AS1/miR-361-5p/FOXM1 axis might play an important role in CC progression. SBF2-AS1 might serve as a potential therapeutic target for CC treatment.

Roles of E-cadherin and Noncoding RNAs in the Epithelial-mesenchymal Transition and Progression in Gastric Cancer

The epithelial–mesenchymal transition (EMT) is thought to be at the root of invasive and metastatic cancer cell spreading. E-cadherin is an important player in this process, which forms the structures that establish and maintain cell–cell interactions. A partial or complete loss of E-cadherin expression in the EMT is presumably mediated by mechanisms that block the expression of E-cadherin regulators and involve the E-cadherin-associated transcription factors. The protein is involved in several oncogenic signaling pathways, such as the Wnt/β-catenin, Rho GTPase, and EGF/EGFR, whereby it plays a role in many tumors, including gastric cancer. Such noncoding transcripts as microRNAs and long noncoding RNAs—critical components of epigenetic control of gene expression in carcinogenesis—contribute to regulation of the E-cadherin function by acting directly or through numerous factors controlling transcription of its gene, and thus affecting not only cancer cell proliferation and metastasis, but also the EMT. This review focuses on the role of E-cadherin and the non-coding RNAs-mediated mechanisms of its expressional control in the EMT during stomach carcinogenesis.

Effect of lncRNA HULC knockdown on rat secreting pituitary adenoma GH3 cells

Pituitary adenoma is one of the most common tumors in the neuroendocrine system. This study investigated the effects of long non-coding RNAs (lncRNAs) highly up-regulated in liver cancer (HULC) on rat secreting pituitary adenoma GH3 cell viability, migration, invasion, apoptosis, and hormone secretion, as well as the underlying potential mechanisms. Cell transfection and qRT-PCR were used to change and measure the expression levels of HULC, miR-130b, and FOXM1. Cell viability, migration, invasion, and apoptosis were assessed using trypan blue staining assay, MTT assay, two-chamber transwell assay, Guava Nexin assay, and western blotting. The concentrations of prolactin (PRL) and growth hormone (GH) in culture supernatant of GH3 cells were assessed using ELISA. The targeting relationship between miR-130b and FOXM1 was verified using dual luciferase activity. Finally, the expression levels of key factors involved in PI3K/AKT/mTOR and JAK1/STAT3 pathways were evaluated using western blotting. We found that HULC was highly expressed in GH3 cells. Overexpression of HULC promoted GH3 cell viability, migration, invasion, PRL and GH secretion, as well as activated PI3K/AKT/mTOR and JAK1/STAT3 pathways. Knockdown of HULC had opposite effects and induced cell apoptosis. HULC negatively regulated the expression of miR-130b, and miR-130b participated in the effects of HULC on GH3 cells. FOXM1 was a target gene of miR-130b, which was involved in the regulation of GH3 cell viability, migration, invasion, and apoptosis, as well as PI3K/AKT/mTOR and JAK1/STAT3 pathways. In conclusion, HULC tumor-promoting roles in secreting pituitary adenoma might be via down-regulating miR-130b, up-regulating FOXM1, and activating PI3K/AKT/mTOR and JAK1/STAT3 pathways.