Targeting PI3K/AKT/mTOR-mediated autophagy for tumor therapy

Integrated Analysis Reveals S100a8/a9 Regulates Autophagy and Apoptosis through the MAPK and PI3K-AKT Signaling Pathway in the Early Stage of Myocardial Infarction

Myocardial infarction (MI), a type of coronary heart disease, has had a significantly increased incidence in recent years. The balance of cardiomyocyte apoptosis and autophagy after MI is one of the main determinants of patient prognosis. Both affect myocardial fibrosis and ventricular remodeling and regulate cell survival. However, there are few studies on the regulation mechanism of cardiomyocyte autophagy and apoptosis in the early stage after MI. In this study, based on analyzing the scRNA-seq and mRNA-seq data of mice in the early stage of MI, we found that the expression of S100a8 and S100a9 increased first and then decreased in the early stage of MI, and their expression level changed with the number of neutrophils. Further, through the functional enrichment analysis of the differentially expressed genes, we found that S100a8 and S100a9 were simultaneously associated with autophagy and apoptosis and could regulate autophagy and apoptosis of cardiomyocytes through MAPK or PI3K-AKT signaling pathways. This study provides valuable insights for clarifying the pathogenesis of early stage MI and improving its early treatment.

IFI35 Promotes Renal Cancer Progression by Inhibiting pSTAT1/pSTAT6-Dependent Autophagy

Interferon-induced protein 35 (IFI35), is currently acknowledged to govern the virus-related immune inflammatory responses. However, the biological significance and function of IFI35 in renal cell cancer (RCC) is still not well understood. Here, IFI35 expression and function were investigated in RCC tissues, renal cancer cells, and animal models. The results showed that IFI35 expression was significantly increased in 200 specimens of RCC patients. We found that higher IFI35 levels were significantly correlated with poor RCC prognosis. In human cell lines, the knockdown of IFI35 suppressed the malignant behavior of renal cancer cells. Similarly, the IFI35 knockdown resulted in significant inhibition of tumor progression in the subcutaneous or lung metastasis mouse model. Furthermore, the knockdown of IFI35 promoted the induction of autophagy by enhancing the autophagy-related gene expression (LC3-II, Beclin-1, and ATG-5). Additionally, blockade of STAT1/STAT6 phosphorylation (pSTAT1/pSTAT6) abrogated the induced autophagy by IFI35 knockdown in renal cancer cells. The autophagy inhibitor 3-MA also abolished the prevention of tumor growth by deleting IFI35 in renal cancer models. The above results suggest that the knockdown of IFI35 suppressed tumor progression of renal cancer by pSTAT1/pSTAT6-dependent autophagy. Our research revealed that IFI35 may serve as a potential diagnosis and therapeutic target for RCC.

Oleanolic acid induces HCT116 colon cancer cell death through the p38/FOXO3a/Sirt6 pathway

Oleanolic acid (OA) is a natural compound that possesses numerous beneficial health effects, including anticancer activity. The current study aimed to investigate the role of forkhead box O3a (FOXO3a) in autophagy/mitophagy by OA in HCT116 cell line. OA dose-dependently reduced viability of HCT116 cells, with IC₅₀ = 29.8 μΜ. The expression of cleaved caspase-3 and poly (ADP-ribose) polymerase 1 increased after OA treatment, suggesting induction of apoptosis. Concurrently, OA induced autophagy, evidenced by increased expression of Beclin-1, autophagy-related protein 5 and microtubule-associated protein1A/1B-light chain 3 beta (LC3B), which played a prosurvival role. The induction of mitophagy was suggested by increased expression of p62 and PTEN-induced kinase 1 and reduced expression of translocase of outer mitochondrial membrane 20, which colocalized with LC3B. OA also induced nuclear accumulation of forkhead box O3a (FOXO3a). The cytotoxic activity of OA coincided with upregulation of p38. Inhibition of p38 led to increase in FOXO3a and NAD⁺-dependent deacetylase sirtuin 6 expression. In vivo, OA inhibited tumor growth in colon cancer xenograft mice. Our results suggest concomitant induction of apoptosis and prosurvival mitophagy by OA in colon cancer via p38/FOXO3a/Sirt6 signaling. Additionally, our data demonstrate that OA can chemosensitize colon cancer cells to 5-fluorouracil (5-FU).

Integrated transcriptomics and proteomics provide new insights into the cadmium-induced ovarian toxicity on Pardosa pseudoannulata

Cadmium (Cd) pollution is intractable heavy metal pollution in the farmland ecosystem, posing a life-threatening challenge to the paddy field organisms. Spiders are riveting animal biomarkers for evaluating Cd-induced toxicity, yet the effects of long-term Cd toxicity on spider reproductive function and its underlying mechanism remain unclear. In the present study, we found that Cd exposure impaired the antioxidant enzyme system in the wolf spider Pardosa pseudoannulata and decreased the concentration of four antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase, and peroxidase) (p < 0.05). The content of vitellogenin and the number of hatched spiderlings were also dramatically reduced under Cd stress (p < 0.05), indicating that Cd stress could vitiate the fecundity of P. pseudoannulata. Moreover, a total of 10,511 differentially expressed genes (DEGs) and 391 proteins (DEPs) were yielded from the ovarian transcriptome and proteome, and a mass of genes and proteins involved in protein processing in endoplasmic reticulum (ER) were significantly down-regulated. DEGs and DEPs directly encoding the antioxidant enzyme system and/or vitellogenesis were also distinctively down-regulated. In addition, we illustrated that the PI3K-AKT signaling pathway might play a crucial role in regulating protein synthesis, cell cycle, growth, differentiation and survival in P. pseudoannulata. The effects of protein processing in ER and PI3K-AKT pathways could further trigger transcriptional factor Forkhead shackling the protein synthesis and cell growth process. Collectively, this integrated analysis identified the Cd-induced reproductive toxicity on P. pseudoannulata and provided multifaceted insights to investigate the molecular mechanisms of spiders to Cd pollution.

USP35 is a Potential Immunosuppressive Factor in Skin Cutaneous Melanoma

Background

As one of the most immunogenic malignancies, skin cutaneous melanoma (SKCM) is mainly characterized by a high prevalence in immune-compromised patients and a brisk lymphocyte infiltration in the tumor microenvironment (TME). However, to date, studies on deubiquitination in SKCM are still very limited.

Methods

Public data with regard to this study in SKCM patients were acquired from The Cancer Genome Atlas (TCGA) and the Gene-Expression Omnibus (GEO) databases. We stratified TCGA-SKCM cases using consensus clustering and identified independent prognostic factors in deubiquitinating enzymes encoding genes (DECGs) by LASSO-Cox analysis. USP35 transcriptome level was examined using public data and validated by Immunohistochemical (IHC) staining at the protein level. Enrichment analysis was used to explore the potential functions of USP35, and the TISCH database, providing further evidence at the single-cell level. The CIBERSORT algorithm was used to assess the relationship between USP35 and the immune microenvironment, and IHC was used to further evaluate the relationship between USP35 and immunotherapy response. Finally, we used the cBioPortal and the Methsurv database to analyze the significance of genomic alterations of USP35 in melanoma.

Results

Our results showed that DECGs can be effectively used to stratify SKCM patients, suggesting their potential significance in the development of SKCM. Furthermore, USP35 overexpression was significantly associated with an unfavorable prognosis. We further revealed that USP35 may be involved in the activation of TORC1 signaling. Most importantly, USP35 was found to be significantly associated with an immunosuppressive TME, both in terms of negative correlation with the abundance of infiltrating CD8+ T cells and in terms of the fact that patients with high USP35 expression may benefit less from immunotherapy than those with low USP35 expression.

Conclusion

Deubiquitinating enzymes are of great importance in the diagnosis and treatment of SKCM, and USP35 is an extremely promising target for immunotherapy.

Kaposi's sarcoma-associated herpes virus-derived microRNA K12-1 over-activates the PI3K/Akt pathway to facilitate cancer progression in HIV-related gastrointestinal Kaposi's sarcoma

BACKGROUND

Kaposi's sarcoma-associated herpes virus (KSHV) initiate and accelerate the development of Kaposi's sarcoma (KS), and KSHV possesses many cancer-associated genes, including KSHV-derived microRNA miR-K12-1, which has been identified to be closely associated with KS progression. However, the detailed mechanisms by which miR-K12-1 facilitates HIV-related gastrointestinal KS development are still not fully delineated.

OBJECTIVES

This study strived to evaluate the effect of miR-K12-1 on the progression of HIV-related gastrointestinal KS.

MATERIALS AND METHODS

The expression levels of miR-K12-1 in HIV-related gastrointestinal KS tissues were determined by RT-qPCR. Proliferation and apoptosis were assessed by colony formation, CCK-8 and flow cytometry, respectively. The expression of all proteins was detected by Western blot. The in vivo effect of miR-K12-1 on the formation of a tumor was explored by using the mouse xenograft model.

RESULTS

In this study, we uncovered that KSHV-miR-K12-1 was upregulated in HIV-related gastrointestinal KS tissues and associated with poor outcome in HIV-related gastrointestinal KS patients. Compared with the control group, after miR-K12-1 inhibitor transfection, BCBL-1 cell viability was decreased, and the cell apoptosis was significantly increased, whereas transfection of miR-K12-1 mimics promoted cell proliferation and mitosis. In addition, our rescuing experiments verified that miR-K12-1 promoted cell proliferation via activating the PI3K/Akt pathway, and inhibition of the PI3K/Akt pathway by LY294002 abrogated the tumor-promoting effects of miR-K12-1 in HIV-related gastrointestinal KS.

CONCLUSIONS

In summary, we concluded that KSHV-derived miR-K12-1 activate the PI3K/Akt pathway to initiate and accelerate the development of KS, which convinces us that miR-K12-1 can be used as potential biomarkers for KS diagnosis, treatment and prognosis.

The eIF4A Inhibitor Silvestrol Blocks the Growth of Human Glioblastoma Cells by Inhibiting AKT/mTOR and ERK1/2 Signaling Pathway

The most frequently identified central nervous system tumor in adults is glioblastoma multiforme (GBM). GBM prognosis remains poor despite multimodal treatment, i.e., surgery and radiation therapy with concurrent temozolomide-based chemotherapy. Silvestrol, an eIF4A inhibitor, has been demonstrated to be able to kill tumor cells in previous studies. In this study, it was found that silvestrol considerably attenuated the proliferative potential of U251 and U87 glioma cells and reduced expression of cyclin D1. In addition, silvestrol reduced the level of ERK1/2 and decreased the levels of AKT phosphorylation. Unfortunately, the effect of silvestrol in inhibiting GBM cells was greatly reduced with hypoxia, and the downregulation in AKT/mTOR and ERK1/2 were also rescued with an upregulation of HIF1α, which warranted further research. Taken together, silvestrol exerted antitumor effects in GBM cells by inhibiting the AKT/mTOR and ERK1/2 signaling cascades.

The Potential of Epigallocatechin Gallate (EGCG) in Targeting Autophagy for Cancer Treatment: A Narrative Review

Autophagy is an evolutionarily conserved process for the degradation of redundant or damaged cellular material by means of a lysosome-dependent mechanism, contributing to cell homeostasis and survival. Autophagy plays a multifaceted and context-dependent role in cancer initiation, maintenance, and progression; it has a tumor suppressive role in the absence of disease and is upregulated in cancer cells to meet their elevated metabolic demands. Autophagy represents a promising but challenging target in cancer treatment. Green tea is a widely used beverage with healthy effects on several diseases, including cancer. The bioactive compounds of green tea are mainly catechins, and epigallocatechin-gallate (EGCG) is the most abundant and biologically active among them. In this review, evidence of autophagy modulation and anti-cancer effects induced by EGCG treatment in experimental cancer models is presented. Reviewed articles reveal that EGCG promotes cytotoxic autophagy often through the inactivation of PI3K/Akt/mTOR pathway, resulting in apoptosis induction. EGCG pro-oxidant activity has been postulated to be responsible for its anti-cancer effects. In combination therapy with a chemotherapy drug, EGCG inhibits cell growth and the drug-induced pro-survival autophagy. The selected studies rightly claim EGCG as a valuable agent in cancer chemoprevention.

Antidepressants Fluoxetine Mediates Endoplasmic Reticulum Stress and Autophagy of Non-Small Cell Lung Cancer Cells Through the ATF4-AKT-mTOR Signaling Pathway

Fluoxetine, one of the latest clinical antidepressants, is reported to have the anti-proliferative effect on cancer cells via immune-related pathways. However, the mechanism is still not known. This study mainly focused on the discovery of the molecular basis of the inhibitory effect of fluoxetine in lung cancer. The specific anti-proliferation effect and autophagy induced by fluoxetine on lung cancer cell were shown in CCK8 and immunofluorescence. The RNA sequence hinted that the endoplasmic reticulum (ER) stress-related protein and mTOR pathway were enriched after fluoxetine treatment. Western blot results revealed that the ER stress pathway was activated by fluoxetine, including PERK, ATF4, and CHOP, while the AKT/mTOR pathway was inhibited. In addition, the transfection of ATF4 siRNA further discovered that ER stress participated in the inhibition of AKT/mTOR pathway and the induction of anti-proliferation and autophagy in the fluoxetine-treated cells. More importantly, fluoxetine was demonstrated to play cytotoxic activity in cancer cells without affecting normal cells. Our results showed that fluoxetine triggered the ATF4-AKT-mTOR signaling pathway to induce cell cycle arrest and autophagy restraining cancer cells’ growth in lung cancer. This study found fluoxetine unaffected the proliferation of normal lung epithelial cells, providing safe clinical therapeutic strategies for lung cancer patients with depression.

Electroacupuncture Promotes Autophagy by Regulating the AKT/mTOR Signaling Pathway in Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) is a complex neurological disease, and its occurrence and development are closely related to the autophagy signaling pathway. However, the mechanism by which electroacupuncture (EA) affects the regulation of autophagy has not been fully elucidated. TLE gene chip dataset GSE27166 and data from rats without epilepsy (n = 6) and rats with epilepsy (n = 6) were downloaded from Gene Expression Omnibus. The differentially expressed genes (DEGs) in the TLE and control groups were identified with the online tool GEO2R. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to analyse the functional and pathway enrichment of genes in the most important modules. A rat model of TLE induced by lithium-pilocarpine treatment was established. EA treatment at DU20 and DU14 in TLE rats was performed for 2 weeks. Neuronal regeneration was determined using immunofluorescence staining. The protein levels of AKT/mTOR signaling pathway and autophagy markers were detected through western blotting and immunohistochemistry. This study identified 1837 DEGs, including 798 upregulated genes and 1039 downregulated genes. GO enrichment and KEGG analyses were performed on DEGs and revealed functional enrichment mainly in the mTOR signaling pathway and autophagy-animal. Furthermore, the number of mature neurons was significantly increased upon coexpressing BrdU/NeuN in TLE rats treated with EA. Western blotting and immunohistochemistry results showed significantly decreased levels of the phosphorylated-AKT and p-mTOR in the hippocampal CA3 and DG regions of TLE rats with EA treatment. And increased p-ULK1/ULK1, LC3-II/LC3-I and p62 levels in TLE rats with EA stimulation. Therefore, this study suggested that EA promoted autophagy in hippocampal neurons during the onset of epilepsy by regulating the AKT/mTOR signaling pathway to treat epilepsy.

PGM1 suppresses colorectal cancer cell migration and invasion by regulating the PI3K/AKT pathway

BACKGROUND

Phosphoglucomutase 1 (PGM1) is known for its involvement in cancer pathogenesis. However, its biological role in colorectal cancer (CRC) has remained unknown. Here, we studied the functions and mechanisms of PGM1 in CRC.

METHODS

We verified PGM-1 as a differentially expressed gene (DEG) by employing a comprehensive strategy of TCGA-COAD dataset mining and computational biology. Relative levels of PGM-1 in CRC tumors and adjoining peritumoral tissues were determined by qRT-PCR, western blotting (WB), and immunohistochemical (IHC) staining in a tissue microarray. PGM1 functions were analyzed by CCK8, EdU, colony formation, cell cycle, apoptosis, and Transwell migration and invasion assays. The influence of PGM1 was further investigated by studying tumor formation in vivo.

RESULTS

The levels of PGM1 mRNA and protein were both reduced in CRC tissues, and the reductions were related to CRC pathology and overall survival. PGM1 knockdown stimulated both cell proliferation and colony formation, and inhibited cell cycle arrest and apoptosis, while overexpression of PGM1 produced the opposite effects in CRC cells both in vivo and in vitro. Furthermore, the effects of PGM1 were related to the PI3K/ AKT pathway.

CONCLUSION

We verified that PGM1 suppresses CRC progression via the PI3K/AKT pathway. These results suggest the potential for targeting PGM1 in treatment of CRC.

Identification of novel natural inhibitors targeting AKT Serine/Threonine Kinase 1 (AKT1) by computational study

Despite great progress, the current cancer treatments often have obvious toxicity and side effects. and a poor prognosis (some patients). One of the reasons for the poor prognosis is that certain enzymes prevent anticancer drugs from killing tumor cells. AKT1 is involved in regulating PI3K/AKT/mTOR, a tumor-generating pathway. Ipatasertib, a highly selective inhibitor of AKT1, is widely used in the treatment of tumors. In this study, many structural and biochemical methodswere used to find better AKT1(Threonine Kinase 1) inhibitors, which laid a foundation for the further development of AKT1 inhibitors and provided new drugs for the treatment of tumors. ZINC15 database and Discovery Studio 4.5, a computer-aided drug screening software with many modules (LibDock for virtual screening, ADME (Absorption, Distribution, Metabolism, Excretion) and TOPKAT (toxicity prediction module) for the toxicity and properties analysis, and MD simulation for stability prediction), were employed. CCK8 assay, ELISA assay genicity and higher tolerance to cytochrome P4502D6. MD simulations indicated they could bind with AKT1 stably in the natural environment. The cell experiment and specific assay for AKT1 inhibition showed they could inhibit the proliferation and AKT1 expression of MG63 cells (Osteosarcoma cells). Moreover, these novel compounds with structural modifications can be potential contributors that lead to further rational drug design for targeting AKT1.

AbbreviationAKT1, AKT Serine/Threonine Kinase 1; ADME, absorption, distribution, metabolism, excretion; TOPKAT, toxicity prediction by Computer assisted technology; CCK8, Cell Counting Kit 8; ELISA, Enzyme-linked immunosorbent assay; CYP2D6, cytochrome P4502D6 inhibition; GBM, Glioblastoma; AGC kinase, protein kinase A, G, and C families (PKA, PKC, PKG); PKB, protein kinase B; PAM pathway, PI3K/AKT/mTOR pathway; OS, overall survival; PFS, progression-free survival; LD50, lethal dose half in rats; LOAEL, lowest observed adverse effect level; NPT, normal pressure and temperature; PME, particle mesh Ewald; LINCS, linear constraint solver; RMSD, root-mean-square deviation; BBB, blood–brain barrier; DS, Discovery Studio; DTP, Developmental toxicity potential; PPB, Plasma protein binding; MTD, Maximum Tolerated Dosage; AB, Aerobic Biodegradability; NTP, US. National Toxicology Program; DTP, developmental toxicity potential.

Purified PTEN-Long Induces Liver Cancer Cells to Undergo Autophagy and Apoptosis

Background

PTEN-Long is a translational variant of phosphatase and tensin homolog deleted on chromosome 10 (PTEN). This tumor suppressor is frequently lost or mutated and even it has been shown as the determinant in several human tumors. Therefore, we will determine the significant roles of PTEN-Long in the development of liver cancer.

Methods

In the present study, we characterized the antitumor effects of PTEN-Long and PTEN in proliferation, migration of HepG2 cells, apoptosis and autophagy in liver cancer cells. To extends, we have also measured the effects of purified PTEN and PTEN-Long in the above index of HepG2 cells.

Results

PTEN and PTEN-Long were ectopic-expressed in HepG2 cells, and their phenotypic effects were recorded. As expected, there was less expression of PTEN-Long and PTEN in liver cancer samples than in paired normal tissues. Ectopic expression of PTEN-Long or PTEN significantly decreased the proliferation and migration of HepG2 cells and increased apoptosis. PTEN ectopic-expression increased the number of GFP-/RFP+-LC3 puncta and levels of beclin-1 and LC3BII/LC3BI, suggesting autophagy induction. Purified PTEN-Long freely entered cells, decreased proliferation, and increased autophagy and apoptosis, while purified PTEN did not.

Conclusions

Our results identify an antitumor function of purified PTEN-Long and suggest its potential utility for liver cancer treatment.

L3MBTL2-mediated CGA transcriptional suppression promotes pancreatic cancer progression through modulating autophagy

L3MBTL2 is a crucial component of ncPRC1.6 and has been implicated in transcriptional repression and chromatin compaction. However, the repression mechanism of L3MBTL2 and its biological functions are largely undefined. Here, we found that L3MBTL2 plays a distinct oncogenic role in tumor development. We demonstrated that L3MBTL2 repressed downstream CGA through an H2AK119ub1-dependent mechanism. Importantly, the binding of the MGA/MAX heterodimer to the E-box on the CGA promoter enhanced the specific selective repression of CGA by L3MBTL2. CGA encodes the alpha subunit of glycoprotein hormones; however, we showed that CGA plays an individual tumor suppressor role in PDAC. Moreover, CGA-transcript1 (T1) was identified as the major transcript, and the tumor suppression function of CGA-T1 depends on its own glycosylation. Furthermore, glycosylated CGA-T1 inhibited PDAC, partly by repression of autophagy through multiple pathways, including PI3K/Akt/mTOR and TP53INP2 pathways. These findings reveal the important roles of L3MBTL2 and CGA in tumor development.

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L3MBTL2 plays a distinct oncogenic role in tumor development

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L3MBTL2 represses CGA transcription mainly by mediating ubiquitination of H2A

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CGA plays an individual tumor suppressor role in pancreatic cancer

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Glycosylated CGA inhibited PDAC partly through repression of autophagy

Biosynthesis and cytotoxic effect of silymarin-functionalized selenium nanoparticles induced autophagy mediated cellular apoptosis via downregulation of PI3K/Akt/mTOR pathway in gastric cancer

BACKGROUND

Silymarin, a blend of flavonolignans isolated from plant Silybum marianum L., has long been used as an herbal medicine. Biogenic routes especially the plant-based synthesis of selenium nanoparticles (SeNPs) is safe, eco-friendly, nontoxic and being considered as one of the best strategies for treatment of cancer.

PURPOSE

Silymarin-mediated green synthesis of SeNPs and their possibility as an anticancer agent have not been reported to date. Therefore, our present study was aimed to synthesize and characterize the selenium mediated silymarin nanoparticles (Si-SeNPs) from silymarin and investigate their possibility as an anticancer agent.

METHODS

The physicochemical characteristics of Si-SeNPs were analyzed using various analytical techniques, such as HPLC, field emission-transmission electron microscope, energy-dispersive X-ray spectrometer, and thermogravimetric analysis. The underlying molecular mechanism were evaluated using AGS gastric cancer cells.

RESULTS

Compared with silymarin, the Si-SeNPs exhibited significantly increased cytotoxic effect of AGS cells without exhibiting toxicity on normal cells. Real time PCR and western blotting analysis indicated that Si-SeNPs induced expression of Bax/Bcl-2, cytochrome c, and cleavage of caspase proteins, which is associated with mitochondria-mediated apoptosis signaling in AGS cells. Moreover, agonist assay using PI3K activator indicated that Si-SeNPs-inhibited PI3K/AKT/mTOR pathways were significantly associated as an autophagy and apoptosis signaling in AGS cells.

CONCLUSION

Our study demonstrated the improved anticancer efficacy of Si-SeNPs- induced apoptosis and autophagy pathways, and therefore recommended Si-SeNPs as a novel anticancer agent after in vivo studies.

A Review: PI3K/AKT/mTOR Signaling Pathway and Its Regulated Eukaryotic Translation Initiation Factors May Be a Potential Therapeutic Target in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor developing from the esophageal squamous epithelium, and is the most common histological subtype of esophageal cancer (EC). EC ranks 10th in morbidity and sixth in mortality worldwide. The morbidity and mortality rates in China are both higher than the world average. Current treatments of ESCC are surgical treatment, radiotherapy, and chemotherapy. Neoadjuvant chemoradiotherapy plus surgical resection is recommended for advanced patients. However, it does not work in the significant promotion of overall survival (OS) after such therapy. Research on targeted therapy in ESCC mainly focus on EGFR and PD-1, but neither of the targeted drugs can significantly improve the 3-year and 5-year survival rates of disease. Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is an important survival pathway in tumor cells, associated with its aggressive growth and malignant progression. Specifically, proliferation, apoptosis, autophagy, and so on. Related genetic alterations of this pathway have been investigated in ESCC, such as PI3K, AKT and mTOR-rpS6K. Therefore, the PI3K/AKT/mTOR pathway seems to have the capability to serve as research hotspot in the future. Currently, various inhibitors are being tested in cells, animals, and clinical trials, which targeting at different parts of this pathway. In this work, we reviewed the research progress on the PI3K/AKT/mTOR pathway how to influence biological behaviors in ESCC, and discussed the interaction between signals downstream of this pathway, especially eukaryotic translation initiation factors (eIFs) and the development and progression of ESCC, to provide reference for the identification of new therapeutic targets in ESCC.

Theabrownins Produced via Chemical Oxidation of Tea Polyphenols Inhibit Human Lung Cancer Cells in vivo and in vitro by Suppressing the PI3K/AKT/mTOR Pathway Activation and Promoting Autophagy

During the fermentation of dark tea, theabrownins (TBs), carbohydrates, and other substances get irreversibly complex. Recent research on the biological activity of TBs is not based on free TBs. In the present study, some brown polyphenol oxidized polymers, the generalized TBs (TBs-C), were prepared via alkali oxidation from tea polyphenols (TP). We also investigated the inhibitory mechanism of TBs-C on non-small-cell-lung cancer (NSCLC). TBs-C demonstrated a stronger inhibition than TP on the NSCLC cell lines A549, H2030, HCC827, H1975, and PC9. Next, A549 and H2030 cell lines were selected as subjects to explore this mechanism. TBs-C was found to inhibit proliferation, promote apoptosis, and induce G1 cell-cycle arrest in the cells. In addition, TBs-C increased autophagic flux, which in turn promoted the death of lung cancer cells. Moreover, TBs-C suppressed the PI3K/AKT/mTOR pathway activation, promoted autophagy, and increased the expression of p21 downstream of AKT, which resulted in G1 cell-cycle arrest. In xenotransplanted NSCLC nude mice derived from A549 cells, TBs-C could significantly suppress tumor growth by inhibiting the PI3K/AKT/mTOR pathway without causing hepatotoxicity, brain toxicity, or nephrotoxicity. We believe that our present findings would facilitate advancement in the research and industrialization of TBs.

Targeting regulated cell death (RCD) with small-molecule compounds in triple-negative breast cancer: a revisited perspective from molecular mechanisms to targeted therapies

Triple-negative breast cancer (TNBC) is a subtype of human breast cancer with one of the worst prognoses, with no targeted therapeutic strategies currently available. Regulated cell death (RCD), also known as programmed cell death (PCD), has been widely reported to have numerous links to the progression and therapy of many types of human cancer. Of note, RCD can be divided into numerous different subroutines, including autophagy-dependent cell death, apoptosis, mitotic catastrophe, necroptosis, ferroptosis, pyroptosis and anoikis. More recently, targeting the subroutines of RCD with small-molecule compounds has been emerging as a promising therapeutic strategy, which has rapidly progressed in the treatment of TNBC. Therefore, in this review, we focus on summarizing the molecular mechanisms of the above-mentioned seven major RCD subroutines related to TNBC and the latest progress of small-molecule compounds targeting different RCD subroutines. Moreover, we further discuss the combined strategies of one drug (e.g., narciclasine) or more drugs (e.g., torin-1 combined with chloroquine) to achieve the therapeutic potential on TNBC by regulating RCD subroutines. More importantly, we demonstrate several small-molecule compounds (e.g., ONC201 and NCT03733119) by targeting the subroutines of RCD in TNBC clinical trials. Taken together, these findings will provide a clue on illuminating more actionable low-hanging-fruit druggable targets and candidate small-molecule drugs for potential RCD-related TNBC therapies.

Nigrosporins B, a Potential Anti-Cervical Cancer Agent, Induces Apoptosis and Protective Autophagy in Human Cervical Cancer Ca Ski Cells Mediated by PI3K/AKT/mTOR Signaling Pathway

Nigrosporins B, an anthraquinone derivative obtained from the secondary metabolites of marine fungus Nigrospora oryzae. In this study, we characterized the distinctive anti-cancer potential of Nigrosporins B in vitro and underlying molecular mechanisms in human cervical cancer Ca Ski cells for the first time. The results of MTT assay showed that Nigrosporins B significantly inhibited the proliferation of multiple tumor cells in a dose-dependent manner, especially for the Ca Ski cells with an IC50 of 1.24 µM. Nigrosporins B exerted an apoptosis induction effect on Ca Ski cells as confirmed by flow cytometry, AO/EB dual fluorescence staining, mitochondrial membrane potential analysis and western blot assay. In addition, Nigrosporins B induced obvious autophagy accompanied with the increase of autophagic vacuoles and the acceleration of autophagic flux as indicated by Cyto-ID staining, mRFP-GFP-LC3 adenovirus transfection and western blot analysis. Interestingly, the combination of Nigrosporins B with the three autophagy inhibitors all significantly enhanced the cytotoxicity of Nigrosporins B on Ca Ski cells, indicating that the autophagy induced by Nigrosporins B might protect Ca Ski cells from death. Furthermore, we found that Nigrosporins B inhibited the phosphorylation of PI3K, AKT, mTOR molecules and increased the protein expression levels of PTEN and p-AMPKα in a dose-dependent manner, suggesting that Nigrosporins B induced apoptosis and protective autophagy through the suppression of the PI3K/AKT/mTOR signaling pathway. Together, these findings revealed the anti-cervical cancer effect of Nigrosporins B and the underlying mechanism of action in Ca Ski cells, it might be as a promising alternative therapeutic agent for human cervical cancer.

miRNA-29 aggravates myocardial infarction via inhibiting the PI3K/mTOR/HIF1α/VEGF pathway

Introduction: MI is defined by the presence of myocardial necrosis, which is caused by acute and persistent ischemia and hypoxia of the coronary artery. In recent years, its incidence rate has been on the rise in China.

Methods: GSE34198, GSE97320 and GSE141512 datasets were download for DEG analysis. KEGG pathway analysis, GO analysis, GSEA and PPI network construction were performed. Later, target genes of candidate miRNAs were predicted. Next, echocardiography was conducted to detect the effects of miR-29 on left ventricular structure and cardiac function in vivo, and H&E staining was adopted to study the effects of miR-29 on angiogenesis and fibrosis in vivo. Furthermore, Western blotting was employed to investigate the effects of miR-29 inhibition on the expressions of proteins related to the PI3K\mTOR\ HIF-1α\VEGF pathway.

Results: There were 162 DEGs involved in MI. GO analysis revealed that inflammatory responses, negative regulation of apoptosis and innate immune response were the main enriched biological processes. KEGG analysis manifested that DEGs were mainly enriched in the PI3K/Akt signaling pathway, and GSEA demonstrated that they were mainly enriched in the PI3K/Akt/mTOR, HIF and VEGF pathways. Moreover, target gene prediction showed that miR-29 was lowly expressed in MI. According to Masson's trichrome staining, miR-29 inhibition promoted angiogenesis, reduced fibrosis, and increased the protein expressions of p-PI3K, p-mTOR, HIF-1α, and VEGF.

Conclusions: MiR-29 may play an important role in the growth and development of MI. After inhibition of miR-29, the PI3K/mTOR/HIF-1α/VEGF pathway is activated to alleviate MI.

Mammalian Target of Rapamycin as the Therapeutic Target of Vascular Proliferative Diseases: Past, Present, and Future

ABSTRACT

The abnormal proliferation of vascular smooth muscle cells (VSMCs) is a key pathological characteristic of vascular proliferative diseases. Mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that plays an important role in regulating cell growth, motility, proliferation, and survival, as well as gene expression in response to hypoxia, growth factors, and nutrients. Increasing evidence shows that mTOR also regulates VSMC proliferation in vascular proliferative diseases and that mTOR inhibitors, such as rapamycin, effectively restrain VSMC proliferation. However, the molecular mechanisms linking mTOR to vascular proliferative diseases remain elusive. In our review, we summarize the key roles of the mTOR and the recent discoveries in vascular proliferative diseases, focusing on the therapeutic potential of mTOR inhibitors to target the mTOR signaling pathway for the treatment of vascular proliferative diseases. In this study, we discuss mTOR inhibitors as promising candidates to prevent VSMC-associated vascular proliferative diseases.

Exploring the Pharmacological Mechanisms of Xihuang Pills Against Prostate Cancer via Integrating Network Pharmacology and Experimental Validation In Vitro and In Vivo

Background: Drug resistance is the major cause of increasing mortality in prostate cancer (PCa). Therefore, it an urgent to develop more effective therapeutic agents for PCa treatment. Xihuang pills (XHP) have been recorded as the efficient anti-tumor formula in ancient Chinese medical literature, which has been utilized in several types of cancers nowadays. However, the effect protective role of XHP on the PCa and its underlying mechanisms are still unclear.

Methods: The active ingredients of XHP were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and BATMAN-TCM. The potential targets of PCa were acquired from the Gene Cards and OMIM databases. R language and Perl language program were utilized to clarify the interaction between the PCa-related targets and the potential targets of XHP. The potential targets of XHP for prostate cancer were gathered from the Gene ontology and KEGG pathway. Furthermore, cell proliferation assays were verified by PC3 and LNCaP cells. The efficacy and potential mechanism tests were confirmed by the PCa PC3 cells and mice subcutaneous transplantation. The effects of PI3K/Akt/mTOR-related proteins on proliferation, apoptosis, and cell cycle of PCa cells were measured by the Cell Counting Kit-8(CCK8), TUNEL assay, real-time quantitative reverse transcription PCR (QRT-PCR), and Western Blotting, respectively.

Results: The active components of four traditional Chinese medicines in XHP were searched on the TCMSP and Batman TCM database. The biological active components of XHP were obtained as OB ≥30% and DL ≥0.18. The analysis of gene ontology and KEGG pathway identified the PI3K/Akt/mTOR signaling pathway as the XHP-associated pathway. Collectively, the results of in vitro and in vivo experiments showed that XHP had the effect of inhibiting on the proliferation of PC3 and LNCaP cells. XHP promoted the apoptosis and restrained the cell cycle and invasion of the PC3 cells and subcutaneous transplantation. Meanwhile, the suppression of XHP on the level of expression of PI3K, Akt, and mTOR-pathway-related pathway proteins has been identified in a dose-dependent manner.

Conclusion: PI3K/Akt/mTOR pathway-related pathway proteins were confirmed as the potential XHP-associated targets for PCa. XHP can suppress the proliferation of prostate cancer via inhibitions of the PI3K/Akt/mTOR pathway.

A liposome-based combination strategy using doxorubicin and a PI3K inhibitor efficiently inhibits pre-metastatic initiation by acting on both tumor cells and tumor-associated macrophages

Pre-metastatic initiation is essential in tumor metastasis, and the inhibition of it could prevent the spread of cancers to distant organs. Both tumor-associated macrophages (TAMs) and the epithelial-mesenchymal transition (EMT) play an important role in the pre-metastatic initiation stage. Herein, a liposome-based combination strategy which involves doxorubicin-loaded liposomes (Lip-Dox) and PI3K inhibitor-loaded liposomes (Lip-LY) was developed to simultaneously regulate tumor cells and TAMs for inhibiting pre-metastatic initiation. In tumor cells, Lip-LY sensitized cells to Lip-Dox treatment and inhibited the EMT process which was promoted by succinate, further mitigating succinate-induced migration and invasion of 4T1 cells. In TAMs, Lip-LY could efficiently inhibit the polarization of TAMs and reduce the percentage of M2 TAMs, so as to exhibit synergistic effects with Lip-Dox in TAM-induced metastasis. As a result, the combination treatment successfully reduced the lung metastasis of 4T1 bearing BALB/c mice by destroying metastatic tumor cells and inhibiting pre-metastatic initiation with decreased metastasis-associated protein expression. Overall, our work provided a simple and promising combination strategy for inhibiting pre-metastatic initiation in multiple ways to treat cancer metastasis.

PTPN18 Stimulates the Development of Ovarian Cancer by Activating the PI3K/AKT Signaling

Objective

To illustrate the functions of protein tyrosine phosphatase nonreceptor type 18 (PTPN18) in the progression of ovarian cancer and the potential molecular mechanism.

Methods

Differential PTPN18 expression in ovarian cancer samples was determined. Following PTPN18 knockdown, changes in proliferation and migration in ovarian cancer cells were detected. Nude mice with ovarian cancer were used to uncover the effects of PTPN18 on ovarian cancer growth in vivo.

Results

PTPN18 was significantly upregulated in ovarian cancer samples and linked to pathological staging and metastasis rate. PTPN18 displayed prognostic and diagnostic potentials in ovarian cancer. Knockdown of PTPN18 and treatment of the PI3K inhibitor could inhibit proliferative and migratory abilities in ovarian cancer cells. Moreover, PTPN18 was capable of inactivating PI3K/AKT signaling. In vivo knockdown of PTPN18 suppressed ovarian cancer growth in nude mice.

Conclusions

PTPN18 is upregulated in ovarian cancer, which stimulates the malignant development by activating PI3K/AKT signaling. The PTPN18 level is also associated with pathological staging and metastasis in ovarian cancer patients, which may be utilized as a hallmark predicting the malignant level.

Correlation of LAGE3 with unfavorable prognosis and promoting tumor development in HCC via PI3K/AKT/mTOR and Ras/RAF/MAPK pathways

Background

Hepatocellular carcinoma (HCC) is one of the most common clinical malignancies quite susceptible to recurrence and metastasis. Despite several improvements in therapeutic approaches, the prognosis remains poor due to the limited treatment options. A bioinformatics analysis based on TCGA databases revealed that the recombinant human L antigen family member 3 (LAGE3) might function as an effective prognostic and diagnostic biomarker for HCC, as LAGE3, a protein-coding gene, maintains several important biological functions and has a physiological significance in the CTAG family while simultaneously being involved in regulating the occurrence and invasion of numerous types of tumors. However, the LAGE3 gene’s functional and regulatory mechanism in the progression of HCC remains unclear.

Methods

The LAGE3 level was investigated in 79 HCC tissues cases, ten HCC adjacent tissue cases, and six cases of normal liver tissues by IHC, while the LAGE3 level was evaluated in BEL-7404, SMCC-7721, Huh-7, HepG2, and MIHA cell lines by qRT-PCR and Western blot tests. Although the proliferation, migration, invasion, and apoptotic abilities of HCC cells were measured in vitro after silencing assay to probe the role of LAGE3 in HCC cells, the tumor xenograft growth experiment was used to verify the in vivo effect of LAGE3 gene knockdown on the growth of HCC tumors combined with bioinformatics analysis to study the LAGE3 mechanisms regulating HCC proliferation.

Results

Our results implied that LAGE3 was extensively expressed in HCC cell lines like BEL-7404, SMCC-7721, and Huh-7 cells as well as HCC tissues, but a lower expression was observed in HepG2 cells. Additionally, LAGE3 restrains cellular proliferation, promotes apoptotic pathways in HCC cells, and inhibits the growth of HCC tumors in vivo. Lastly, it was stated that LAGE3 might promote tumor development in HCC via PI3K/AKT/mTOR and Ras/RAF/MAPK pathways.

Conclusion

This study shows that the development of specific LAGE3 target drugs might become new effective treatment modalities for HCC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09398-3.

The role of miRNAs as a big master regulator of signaling pathways involved in lymphoblastic leukemia

MicroRNAs (miRNAs) belong to small noncoding RNAs, which have long attracted researchers' attention because of their potency in acting either as oncogenes or tumor-suppressors in cancers. acute lymphocytic leukemia (ALL) and chronic lymphocytic leukemia (CLL) are two known types of leukemia with high mortality rates in adults and children. On a molecular basis, various signaling pathways are active in both types, making researchers consider the potential role of miRNAs in activating or suppressing these pathways to further hinder cancer development. In this review, we summarized the potential miRNAs, especially circulating ones, involved in essential signaling pathways in the ALL and CLL patients which serve as biomarkers and valuable targets in the treatment fields.

Shikonin induces apoptosis and autophagy via downregulation of pyrroline-5-carboxylate reductase1 in hepatocellular carcinoma cells

Shikonin(SK) is a natural small molecule naphthoquinone compound, which has anti-cancer activity in various human malignant tumors. Pyrroline-5-carboxylate reductase 1(PYCR1) is involved in tumorigenesis and regulates various cellular processes, including growth, invasion, migration, and apoptosis. However, the effect of SK and PYCR1 on apoptosis and autophagy in hepatocellular carcinoma are unclear. Our goal is to determine the internal molecular mechanism of the interaction between SK and PYCR1 and its role in the occurrence and development of liver cancer. The CCK8 assay, wound healing assay, and transwell assays show that SK and siPYCR1(gene silence PYCR1) inhibited the malignant phenotype of HCC cells, including cell viability, colony formation, migration, and invasion, respectively. The flow cytometry assays and immunofluorescence show that SK and siPYCR1 activated apoptosis and autophagy, respectively. SK induces apoptosis and autophagy in a dose-dependent manner. In addition, HCC cells were transfected with small interference fragment PYCR1 siRNA to construct siPYCR1 and SK single treatment group and co-treatment group to verify the interaction between SK and PYCR1. The Western blot identified that PI3K/Akt/mTOR signal pathway protein expression was significantly downregulated in HCC cells treated with SK and siPYCR1 together. Collectively, SK may induce apoptosis and autophagy by reducing the expression of PYCR1 and suppressing PI3K/Akt/mTOR. Thus, SK may be a promising antineoplastic drug in Hepatocellular carcinoma (HCC). SK downregulating PYCR1 might supply a theoretical foundation for the potential therapeutic application in hepatocellular carcinoma.

Trimetazidine mitigates high glucose-induced retinal endothelial dysfunction by inhibiting PI3K/Akt/mTOR pathway-mediated autophagy

Trimetazidine (TMZ), as a metabolic regulator, has been widely testified to exhibit positive therapeutic effects on various disease models, but its role in diabetic retinopathy has not been reported. Therefore, this study was designed with the purpose of exploring the effects of TMZ on high-glucose (HG)-induced retinal endothelial dysfunction and its underlying mechanism. To establish DR model in vitro, 30 mM glucose was applied to induce human retinal endothelial cells (HRECs). Cell proliferation, invasion, and migration were examined by means of Cell Counting Kit-8, transwell, and wound healing assays, respectively. The tubule formation experiment was used to test the tubulogenesis ability and fluorescein isothiocyanate (FITC)-albumin was utilized to measure the permeability of monolayer HRECs. In addition, immunofluorescence and Western blot were employed to detect protein expression. Compared with the HG-induced group, TMZ concentration dependently inhibited the proliferation, migration, and angiogenesis of HG-induced HRECs, decreased the permeability of monolayer HRECs, and increased the protein expression levels of Claudin-5 and VE-cadherin. In addition, TMZ intervention increased the expression of p-PI3K, p-AKT, and p-mTOR but decreased the expression of LC3I, LC3II, and Beclin 1, which were then partially reversed by P13 K inhibitor (LY294002). Moreover, the autophagy agonist rapamycin (RAPA) was also testified to reverse the inhibitory effects of TMZ on the proliferation, migration, and angiogenesis of HG-induced HRECs. In summary, TMZ inhibited excessive autophagy by activating PI3K/Akt/mTOR pathway, thereby improving retinal endothelial dysfunction induced by HG.

Inhibition of PI3K/AKT/mTOR Signalling Pathway Activates Autophagy and Suppresses Peritoneal Fibrosis in the Process of Peritoneal Dialysis

Peritoneal dialysis (PD) is an important part of replacement therapy for kidney failure. However, long-term PD treatment can cause peritoneal fibrosis. Autophagy may be involved in the pathological mechanism of peritoneal fibrosis (PF). Although autophagy is currently known to be involved in course of PF, its specific effects still lack in-depth research. In this experiment, a high-glucose (HG)-induced peritoneal fibrosis rat model was successfully established via intraperitoneal injection of HG peritoneal dialysate, and the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and the mechanistic target of rapamycin (mTOR) inhibitor rapamycin were used to treat peritoneal fibrosis rats. In addition, in vitro studies of high glucose-induced peritoneal fibrosis were performed using rat peritoneal mesothelial cells (PMCs). In vivo and in vitro experiments showed that LY294002 and rapamycin effectively inhibited the process of PF induced by high glucose. In addition, LY294002 and rapamycin were found to alleviate fibrosis by eliminating intracellular reactive oxygen species (ROS) levels, promoting the expression of the epithelial mesenchymal transdifferentiation proteins zonula occludens-1 (ZO-1) and E-cadherin, and inhibiting the expression of p-PI3K, PI3K, p-mTOR, mTOR, the fibroblast-specific proteins ferroptosis suppressor protein 1 (FSP1), and alpha-smooth muscle actin (α-SMA). Moreover, LY294002 and rapamycin promoted expression of autophagy-related proteins LC3-II/I, p62, and beclin-1. The current data indicated that inhibition of PI3K/AKT/mTOR signalling pathway activated autophagy and suppressed PF in the process of PD. Therefore, intervention in this signalling pathway may become a research goal for the prevention and treatment of PF, which has important clinical significance.

Fabrication of chitosan/PVP/dihydroquercetin nanocomposite film for in vitro and in vivo evaluation of wound healing

The high cost of wound healing treatment, the slow recovery of wounds, and the uncertainty of being affected by the body's physiological activities constitute a serious burden on public health. In this work, we report the preparation and characterization of chitosan (CS), PVP, and dihydroquercetin (DHQ) nanofiber film used as wound excipients, as well as in vivo and in vitro evaluations, and verify that the film is effective in wounds. The results show that the prepared film has good morphology, thermal stability and hydrophilicity. In vitro studies have shown that it has antibacterial activity against S.aureus and E.coli, and the DPPH free radical scavenging rate proves that the fiber film has antioxidant activity. MTT cytotoxicity test proved that the film is non-toxic to Hacat cells. Animal experiments have proved that wounds treated with CS-PVP-DHQ nanofiber film heal faster. This article also studied the composite nanofiber film by inducing autophagy pathway and increasing the expression of pan-keratin, vascular endothelial growth factor VEGF and CD31 to promote wound healing. Therefore, the nanofiber film herein show great potential in wound healing applications.

Targeting Protein Kinase C for Cancer Therapy

Simple Summary

The protein kinase C (PKC) family belongs to serine-threonine kinases and consists of several subtypes. Increasing evidence suggests that PKCs are critical players in carcinogenesis. Interestingly, PKCs exert both promotive and suppressive effects on tumor cell growth and metastasis, which have attracted immense attention. Herein, we systematically review the current advances in the structure, regulation and biological functions of PKCs, especially the relationship of PKCs with anti-cancer therapy-induced cell death, including the current knowledge of PKCs function in tumor metabolism and microenvironment. Moreover, we discuss the potential role of PKCs as a target for therapeutic intervention in cancer from basic research and clinical trials.

Abstract

Protein kinase C (PKC) isoforms, a group of serine-threonine kinases, are important regulators in carcinogenesis. Numerous studies have demonstrated that PKC isoforms exert both positive and negative effects on cancer cell demise. In this review, we systematically summarize the current findings on the architecture, activity regulation and biological functions of PKCs, especially their relationship with anti-cancer therapy-induced cell death. Additionally, we elaborate on current knowledge of the effects of PKCs on tumor metabolism and microenvironment, which have gained increasing attention in oncology-related areas. Furthermore, we underscore the basic experimental and clinical implications of PKCs as a target for cancer therapy to evaluate their therapeutic benefits and potential applications.

[Hyperactivation of PI3K/AKT/mTOR signal pathway impairs TNF-α-induced autophagy in mesenchymal stem cells from patients with ankylosing spondylitis]

OBJECTIVE

To investigate the changes in autophagy of mesenchymal stem cells (MSCs) from patients with ankylosing spondylitis and explore the mechanism for decreased autophagy in ASMSCs.

METHODS

MSCs collected from 14 patients with AS (ASMSCs) and from 15 healthy donors (HDMSCs) were cultured in the absence or presence of 25 ng/mL TNF-α for 6 h. Autophagy of the cells was determined by immunofluorescence staining of GFP-LC3B, and the results were confirmed by detecting the protein expressions of autophagy markers LC3 II/LC3 I and P62. The mRNA expressions of the related genes were detected using qRT-PCR, and the protein expressions of the autophagy markers and signaling pathway-related molecules were determined with Western blotting. TG100713 was used to block the PI3K/AKT/mTOR signal pathway, and its effect on autophagy of ASMSCs was evaluated.

RESULTS

ASMSCs showed significantly weaker GFP-LC3B puncta staining and lower protein expression levels of LC3 II/LC3 I but higher levels of P62 protein (P < 0.05), indicating a decreased autophagy capacity as compared with HDMSCs. TNF-α-induced ASMSCs showed significantly higher protein expressions of p-PI3K/ PI3K, p-AKT/AKT and p-mTOR/mTOR than HDMSCs (P < 0.05), suggesting hyperactivation of the PI3K/AKT/mTOR signaling pathway in ASMSCs. Blocking PI3K/AKT/mTOR signaling with TG100713 eliminated the difference in TNF-α-induced autophagy between HDMSCs and ASMSCs.

CONCLUSION

In patients with AS, hyperactivation of the PI3K/AKT/mTOR signaling pathway results in decreased autophagy of the MSCs and potentially contributes to chronic inflammation.

Upregulation of ADAMDEC1 correlates with tumor progression and predicts poor prognosis in non-small cell lung cancer (NSCLC) via the PI3K/AKT pathway

Background

ADAM‐like decysin‐1 (ADAMDEC1) has been reported to play an important role in the pathogenesis of multiple diseases, including cancers. However, its biological role in non‐small cell lung cancer (NSCLC) remains largely unknown. Here, we aimed to investigate the biological functions and potential mechanism of ADAMDEC1 in NSCLC.

Methods

We verified ADAMDEC1 as a DEG by a comprehensive strategy of TCGA and GEO datasets miming and computational biology. Relative levels of ADAMDEC1 in NSCLC tissues and the adjacent peritumoral tissues were identified by qRT‐PCR, WB and IHC staining. The biological function of ADAMDEC1 was determined by CCK8, EdU, colony formation assay, apoptosis, wound healing migration and transwell invasion assays. Then, an in vivo tumor formation assay was conducted to explore the effects of ADAMDEC1 on tumor growth.

Results

The mRNA and protein expression levels of ADAMDEC1 were upregulated in NSCLC tissues and cell lines. ADAMDEC1 expression was associated with clinicopathological characteristics and overall survival of patients with NSCLC. Knockdown of ADAMDEC1 could decrease proliferation and colony forming ability of NSCLC cells, and promoted cell apoptosis, whereas ADAMDEC11 overexpression has opposite effects in NSCLC cells both in vivo and in vitro. Furthermore, we identified ADAMDEC1 accelerates NSCLC progression via activation of the PI3K/ AKT pathway.

Conclusion

We verified that ADAMDEC1 promotes the progression of NSCLC via the PI3K/AKT pathway. These findings showed the potential of ADAMDEC1 to be used for therapeutic approaches in NSCLC.

Matrine exerts antitumor activity in cervical cancer by protective autophagy via the Akt/mTOR pathway in vitro and in vivo

Matrine is a quinazoline alkaloid extracted from Sophora flavescens. The aim of the present study was to determine whether matrine can induce autophagy in the human HeLa and SiHa cervical cancer cell lines in vitro and in vivo. Cell viability assay was used to assess the suppressive effect of matrine and cisplatin on the proliferation of HeLa and SiHa cells. A total of 28 4-week-old female BALB/c nude mice were used for the in vivo study. Autophagy and protein expression were observed via transmission electron microscopy, monodansylcadaverine and immunohistochemical staining and western blotting. The inhibitory effect of matrine on the proliferation of cervical cancer cells was time- and dose-dependent. The combination of matrine and cisplatin synergistically inhibited the proliferation of cervical cancer cells in vitro and in vivo. Transmission electron microscopy showed that after the addition of matrine, numerous autophagosomes and autophagolysosomes were observable in HeLa and SiHa cells, as demonstrated by monodansylcadaverine staining. Western blotting and immunohistochemical staining showed that as the concentration of matrine increased, the expression of the autophagy marker LC3A/B-II also increased significantly in vitro and in vivo. These findings suggested that matrine inhibited the proliferation of cervical cancer cells and induced autophagy by inhibiting the Akt/mTOR signaling pathway. Thus, matrine may represented a potential candidate in combination therapy for cervical cancer as an inducer of autophagy.

CWHM-1008 Induces Apoptosis and Protective Autophagy through the Akt/mTOR Axis in LUAD Cells

Recent studies have revealed that antiparasitic agents showed promising inhibitory effects on tumors, raising a possibility that repositioning this class of drugs may shed new light on clinical therapy against tumors. CWHM-1008 is a novel class of antimalarial drug; however, the inhibitory impact of CWHM-1008 on lung adenocarcinoma (LUAD) cells remains unclear. This study aimed to explore the anticancer effect and underlying mechanisms of CWHM-1008 on LUAD cells in vitro and in vivo. Human LUAD cells, H358 and A549, were treated with varying concentrations of CWHM-1008 at different lengths of time. Cell viability, colony formation, cell count, flow cytometry findings, microtubule-associated protein-1 light chain 3-green- (LC3-) GFP/RFP adenovirus infection status, and the expression of apoptosis and autophagy-related proteins were examined. Potential effects of an autophagy inhibitor (LY294002) and constitutively active Akt plasmid (CA-Akt) on CWHM-1008-induced apoptosis were also examined. Our results showed that CWHM-1008 significantly inhibited proliferation, induced apoptosis, and enhanced autophagy flux by blocking the RAC-alpha serine/threonine-protein kinase/the mammalian target of rapamycin (Akt/mTOR) axis in two LUAD cells. In addition, autophagy inhibited by LY294002 or CA-Akt transfection accelerated CWHM-1008-induced apoptosis in those LUAD cells. Moreover, CWHM-1008 significantly inhibited the growth and induced apoptosis of A549 cell in nude mice in vivo. The present findings provide new insights into anticancer properties of CWHM-1008, suggesting that it may be an adjuvant treatment for LUAD treatment, warranting further study.

A new discovery: Total Bupleurum saponin extracts can inhibit the proliferation and induce apoptosis of colon cancer cells by regulating the PI3K/Akt/mTOR pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Bupleurum chinense DC has a history of using herb in China for more than 2000 years, which can be traced back to the Classic of Shennong Materia Medica in the Han Dynasty. Although Saikosaponin, the main active ingredient of Bupleurum, has the effects of anti-tumor, yet we still do not know the mechanism by total Bupleurum saponin extracts (TBSE) produces this effect on colon cancer.

AIM OF THE STUDY

It is predicted by network pharmacology that TBSE may play an anti-colon cancer role by regulating the PI3K-Akt-mTOR pathway. The purpose of this study is to investigate whether TBSE inhibits proliferation and promote apoptosis of colon cancer cells by regulating PI3K/Akt/mTOR pathway.

MATERIALS AND METHODS

The effect of saikosaponins on the proliferation of SW480 and SW620 cells was detected by CCK-8, apoptosis was determined by flow cytometry, morphological changes of cells were observed by microscope, nuclear morphological changes were observed after immunofluorescence staining, the expression of apoptosis-related proteins Bax, Bcl2, Caspase3, Caspase9, Cleaved Caspase3 and Cleaved Caspase9 were detected by Western Blot, and the expression of apoptosis-related genes Bax, Bcl2, Caspase3 and Caspase9 were detected by RT-PCR. According to the theory of network pharmacology, the potential targets of saikosaponins and colon cancer were predicted by database Pharmmapper and Genecards database respectively. The intersection of saikosaponins and colon cancer was enriched and analyzed on the Metascape platform. Then, the expression of PI3K/Akt/mTOR pathway related protein PI3K, Akt, Mtor, p-PI3K, p-Akt, p-mTOR were detected by Western Blot, and the corresponding amount of RNA expressions in the pathway was confirmed by RT-PCR.

RESULTS

The results of CCK-8 demonstrated that the survival rate of SW480 and SW620 cells decreased significantly when the concentration of TBSE was in the range of 25-200 μg/ml. The morphological observation showed that the cells lost normal cell morphology, cytoplasmic condensation, and partial loss of adhesion after treatment with TBSE. Flow cytometry indicated that the apoptosis rates of SW480 cells and SW620 cells treated with TBSE (50 μg/ml) were 48.47% ± 1.20% and 36.13% ± 1.76%, respectively. Western Blot firstly confirmed that TBSE significantly up-regulated the expression of pro-apoptotic proteins Bax, Caspase3, Caspase9, Cleaved Caspase3 and Cleaved Caspase9, and down-regulated the expression of anti-apoptotic protein Bcl2. And RT-PCR results implied that TBSE significantly up-regulated the gene expression of apoptotic factors Bax, Caspase3 and Caspase9, and significantly decreased the gene expression of Bcl2. It was predicted that the PI3K/Akt/mTOR pathway may be the main regulatory object of the antitumor effect of TBSE by network pharmacology. Subsequent WB experiment also revealed that TBSE could significantly down-regulate (P < 0.01) the expressions of PI3K, Akt, mTOR and phosphorylated proteins P-PI3K, P-Akt, P-MTOR. Meanwhile, RT-PCR results also indicated that TBSE could significantly down-regulate (P < 0.01) the gene expression levels of PI3K, Akt and mTOR.

CONCLUSIONS

TBSE activated Bax/Bcl2 and caspase-9/caspase-3 cascade to induced apoptosis of human colon cancer SW480 and SW60 cells in a dose-dependent manner, which was obviously related to the inhibition of PI3K/Akt/mTOR signaling pathway.

The m6A methyltransferase METTL3 affects autophagy and progression of nasopharyngeal carcinoma by regulating the stability of lncRNA ZFAS1

Background

Nasopharyngeal carcinoma (NPC) is a malignant tumor originating from the epithelial cells of the nasopharyngeal mucosa of the head and neck. The role of long non-coding RNA and RNA methylation in NPC has received increasing attention. Therefore, this study aims to investigate the mechanism of lncRNA ZFAS1 in NPC and its relationship with RNA methylation, providing evidence for targeted therapy of NPC.

Methods

Microarray arrays were used to screen the differentially expressed miRNAs in normal tissues and tumor tissues. QRT-PCR was used to quantify ZFAS1, miR-100-3p, ATG10, autophagy and epithelial-mesenchymal transition related genes. The interactive relationship between ZFAS1 and miR-100-3p was verified using dual-luciferase reporter gene assay and RIP assay. CCK-8, transwell and apoptosis were used to detect the occurrence of tumor cells after different treatments. The m6A modification test is used to verify the effect of METTL3 on ZFAS1. BALB/c mice and BALB/c nude mice are used to detect the effects of different treatments on tumor growth and immune escape in vivo.

Results

ZFAS1 is upregulated in tumor tissues and NPC cells. N (6)-methyladenosine (m6A) is highly enriched in ZFAS1 and enhances its RNA stability. ZFAS1 is used as an oncogenic lncRNA, which can promote NPC cell proliferation, migration and tumor growth. In terms of mechanism, ZFAS1 up-regulates the expression of ATG10 by competitively adsorbing miR-100-3p and regulates the level of autophagy by inhibiting the PI3K/Akt signaling pathway to promote the proliferation and migration of NPC cells.

Conclusion

In short, our study verified the cancer-promoting effect of ZFAS1 in NPC and explained part of the reason for its upregulation. In addition, we confirmed that ZFAS1 can regulate the autophagy level of NPC cells through the PI3K/AKT pathway through miR-100-3p/ATG10 to affect tumor progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-021-00411-1.

PI3K/AKT/p53 pathway inhibits infectious spleen and kidney necrosis virus infection by regulating autophagy and immune responses

The PI3K/AKT/p53 signaling pathway is activated by various types of cellular stimuli or pathogenic infection, and then regulates fundamental cellular functions to combat these stimulations. Here, we studied the meaningful roles of PI3K/AKT/p53 in regulating cellular machine such as autophagy, immune responses, as well as antiviral activity in Chinese perch brain (CPB) cells infected by infectious spleen and kidney necrosis virus (ISKNV), which is an agent caused devastating losses in mandarin fish (Siniperca chuatsi) industry. We found that ISKNV infection induced up-regulation of host PI3K/AKT/p53 axis, but inhibited autophagy in CPB cells. Interestingly, activation of PI3K/AKT/p53 axis factors trough agonists or overexpression dramatically decreased host autophagy level, inhibited ISKNV replication, and elevated the expression of immune-related genes in CPB cells. In contrast, suppression of PI3K/AKT/p53 pathway by inhibitors or small interfering RNA (siRNA)-mediated gene silence increased the autophagy and ISKNV replication, but down-regulated immune responses in CPB cells. All these results indicate that PI3K/AKT/p53 pathway plays an important role in anti-ISKNV infection and can be used as a new target for controlling ISKNV disease.

Stichoposide C Exerts Anticancer Effects on Ovarian Cancer by Inducing Autophagy via Inhibiting AKT/mTOR Pathway

Purpose

Methods

Results

Conclusion

Imperatorin induces autophagy and G0/G1 phase arrest via PTEN-PI3K-AKT-mTOR/p21 signaling pathway in human osteosarcoma cells in vitro and in vivo

BACKGROUND

Osteosarcoma is the third most common cancer in adolescence and the first common primary malignant tumor of bone. The long-term prognosis of osteosarcoma still remains unsatisfactory in the past decades. Therefore, development of novel therapeutic agents which are effective to osteosarcoma and are safe to normal tissue simultaneously is quite essential and urgent.

METHODS

Firstly, MTT assay, cell colony formation assay, cell migration and invasion assays were conducted to evaluate the inhibitory effects of imperatorin towards human osteosarcoma cells. RNA-sequence assay and bioinformatic analysis were then performed to filtrate and assume the potential imperatorin-induced cell death route and signaling pathway. Moreover, quantitative real-time PCR assay, western blot assay and rescue experiments were conducted to confirm the assumptions of bioinformatic analysis. Finally, a subcutaneous tumor-transplanted nude mouse model was established and applied to evaluate the internal effect of imperatorin on osteosarcoma by HE and immunohistochemistry staining.

RESULTS

Imperatorin triggered time-dependent and dose-dependent inhibition of tumor growth mainly by inducing autophagy promotion and G0/G1 phase arrest in vitro and in vivo. Besides, imperatorin treatment elevated the expression level of PTEN and p21, down-regulated the phosphorylation of AKT and mTOR. In contrast, the inhibition of PTEN using Bpv (HOpic), a potential and selective inhibitor of PTEN, concurrently rescued imperatorin-induced autophagy promotion, cell cycle arrest and inactivation of PTEN-PI3K-AKT-mTOR/p21 pathway.

CONCLUSIONS

This work firstly revealed that imperatorin induced autophagy and cell cycle arrest through PTEN-PI3K-AKT-mTOR/p21 signaling pathway by targeting and up-regulating PTEN in human osteosarcoma cells. Hence, imperatorin is a desirable candidate for clinical treatments of osteosarcoma.

Loss of TACC1 variant25 inducing cell proliferation and suppressing autophagy in head and neck squamous carcinoma

Transforming acidic coiled-coil containing protein1 (TACC1) is closely related to transcription, translation and centrosome dynamics. Dysregulation of TACC1 is associated with multiple malignancies. Alternative splicing (AS) of TACC1 produces multiple variants, which are of great significance in cancer biology. However, the expression and biological functions of TACC1 variants in head and neck squamous cell carcinoma (HNSCC) remain unclear. In this study, we found for the first time that TACC1 variants exhibited a characteristic expression pattern and that TACC1 variant25 (TACC1v25) was downregulated in HNSCC tissues and cell lines. Overexpression of TACC1v25 in Cal27 and Fadu cells significantly inhibited proliferation and promoted autophagy. Moreover, expression levels of nuclear pERK and p-mTOR were significantly decreased, while the expression of Beclin-1 and the LC3II/LC3I ratio were increased in TACC1v25-overexpressed Cal27 and Fadu cells. After the addition of AKT activator SC79 to TACC1v25-overexpressed Cal27 and Fadu cells, the autophagy levels were remarkably rescued. In conclusion, TACC1v25 inhibits HNSCC progression through the ERK and AKT/mTOR pathways by inhibiting proliferation and increasing autophagy. TACC1v25 might have potential use as a tumour suppressor in HNSCC.

Cochlioquinone derivative CoB1 induces cytostatic autophagy in lung cancer through miRNA-125b and Foxp3

BACKGROUND

Lung cancer is the leading cause of cancer death worldwide, yet no effective medication for this disease is available. Cochlioquinone B derivative (CoB1), purified from Salvia miltiorrhiza endophytic Bipolaris sorokiniana, affects the defense against pulmonary pathogens by regulating inflammatory responses. However, the effect of CoB1 on lung cancer and the underlying molecular mechanisms remain unknown. In the present study, we investigate the protective effects of CoB1 on lung cancer and explore its underlying mechanism.

METHOD

We examined the inhibitory effect of CoB1 on lung cancer cells (A549 cells) by MTT and colony formation assay. The effect of CoB1 on cytostatic autophagy in lung cancer cells was verified by Western blot, transmission electron microscopy, and confocal microscopy. The differentially expressed miRNAs were identified using quantitative RT-PCR. Luciferase assay and Northern blot were performed to verify the correlation between miRNA-125b and Foxp3. Protein expression in autophagy-related pathways was detected by Western blot. Xenograft tumor models were constructed to explore the inhibitory effect of CoB1 and the role of miRNA-125b as a suppressor in lung cancer in vivo.

RESULT

CoB1 inhibited lung cancer cell proliferation by inducing cytostatic autophagy both in vitro and in vivo. CoB1-induced autophagy was related to blocking of the PI3K/Akt1/mTOR signaling pathway. In addition, CoB1 induced miR-125b expression via activating the TAK1/MKK4/JNK/Smad axis, thereby reducing Foxp3 expression and further inducing autophagy.

CONCLUSION

This study is the first to report the specific inhibitory function of CoB1 purified from Salvia miltiorrhiza endophytic Bipolaris sorokiniana in lung cancer, which may be due to the induction of autophagy. This study provides evidence and novel insights into the anticancer efficacy of CoB1.

Sertaconazole provokes proapoptotic autophagy via stabilizing TRADD in nonsmall cell lung cancer cells

Nonsmall cell lung cancer (NSCLC) is one of the most commonly diagnosed and lethal cancers characterized by relatively low overall cure and poor survival rates with great challenge for consistent effective clinical treatment. Here we demonstrated that the antifungal sertaconazole displays potent anti-NSCLC effect by promoting apoptosis in vitro and in vivo. Further studies found that sertaconazole induces complete autophagic flux, which contributes to sertaconazole-induced apoptosis and subsequent growth suppression in NSCLC cells. Further studies demonstrated that sertaconazole provokes TNF receptor type 1 associated death domain protein (TRADD) expression via stabilizing it from ubiquitination-mediated degradation, which results in Akt dephosphorylation and thereby triggers proapoptotic autophagy in NSCLC cells. Moreover, we found that TRADD suppression reverses sertaconazole-induced proapoptotic autophagy and relieves growth suppression, indicating the vital role of TRADD-regulated proapoptotic autophagy in the anti-NSCLC activity of sertaconazole. In summary, our findings suggest that sertaconazole could be a highly promising anti-NSCLC drug by triggering proapoptotic autophagy via stabilizing TRADD, which may provide a new potential therapeutic option for patients with NSCLC.

Prediction of Rhizoma Drynariae Targets in the Treatment of Osteoarthritis Based on Network Pharmacology and Experimental Verification

Rhizoma Drynariae has been widely used for the treatment of osteoarthritis (OA), but its potential targets and molecular mechanisms remain to be further explored. Targets of Rhizoma Drynariae and OA were predicted by relevant databases, and a protein-protein interaction (PPI) network was constructed to identify key targets. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to obtain related pathways and then select significant pathways associated with OA. The OA chondrocyte model was established by inflammatory factor-induced SW1353 chondrocytes, and molecular docking was conducted to verify the above theoretical prediction. The results showed that a total of 86 Rhizoma Drynariae-OA interaction targets were identified, among which IL-6 and AKT1 were the key targets in the PPI network. Luteolin was the most critical component of Rhizoma Drynariae. KEGG results indicated that the effects of Rhizoma Drynariae on OA are associated with the PI3K/AKT, TNF, IL-17, apoptosis, and HIF-1 signaling pathway. The PI3K/AKT pathway can activate the downstream NF-κB pathway and further regulate the transcription and expression of downstream IL-6, IL-17, HIF-1α, Bax, and TNF, suggesting that the PI3K/AKT/NF-κB pathway is the critical pathway in the treatment of OA with Rhizoma Drynariae. Active components of Rhizoma Drynariae and key proteins of the PI3K/AKT/NF-κB signaling pathway were subjected to molecular docking, whose results showed that luteolin and IKK-α played a critical role. In vitro experiments indicated that both aqueous extracts of Rhizoma Drynariae (AERD) and luteolin inhibited the expression of IL-6 and HIF-1α and suppressed the activation of PI3K/AKT/NF-κB, IL-17, and TNF pathways. The measurement of mitochondrial membrane potential (Δψm) indicated that AERD and luteolin can decrease the LPS-induced early apoptotic cells. Luteolin had a more prominent inhibitory effect than AERD in the abovementioned in vitro experiments. In conclusion, the therapeutic mechanism of Rhizoma Drynariae against OA may be closely related to the inhibition of the PI3K/AKT/NF-κB pathway and downstream pathways, and luteolin plays a vital role in the treatment.