Discovery of novel potent PI3K/mTOR dual-target inhibitors based on scaffold hopping: Design, synthesis, and antiproliferative activity

The PI3K/AKT/mTOR pathway is one of the most common dysregulated signaling cascade responses in human cancers, playing a crucial role in cell proliferation and angiogenesis. Therefore, the development of anticancer drugs targeting the PI3K and mTOR pathways has become a research hotspot in cancer treatment. In this study, the PI3K selective inhibitor GDC-0941 was selected as a lead compound, and 28 thiophenyl-triazine derivatives with aromatic urea structures were synthesized based on scaffold hopping, serving as a novel class of PI3K/mTOR dual inhibitors. The most promising compound Y-2 was obtained through antiproliferative activity evaluation, kinase inhibition, and toxicity assays. The results showed that Y-2 demonstrated potential inhibitory effects on both PI3K kinase and mTOR kinase, with IC50 values of 171.4 and 10.2 nM, respectively. The inhibitory effect of Y-2 on mTOR kinase was 52 times greater than that of the positive drug GDC-0941. Subsequently, the antitumor activity of Y-2 was verified through pharmacological experiments such as AO staining, cell apoptosis, scratch assays, and cell colony formation. The antitumor mechanism of Y-2 was further investigated through JC-1 experiments, real-time quantitative PCR, and Western blot analysis. Based on the above experiments, Y-2 can be identified as a potent PI3K/mTOR dual inhibitor for cancer treatment.

Circular RNA nuclear receptor interacting protein 1 promoted biliary tract cancer epithelial-mesenchymal transition and stemness by regulating the miR-515-5p/AKT2 axis and PI3K/AKT/mTOR signaling pathway

Biliary tract cancer (BTC) is a devastating malignancy that is notoriously difficult to diagnose and is associated with high mortality. Circular RNA (circRNA) is a class of endogenous non-coding RNA which has been regarded as the key regulator of tumor initiation and progression, including BTC. Circular RNA nuclear receptor interacting protein 1 (circ_NRIP1), as a circular RNA, is abnormally expressed in many human tumors and exhibits diverse functions in cancer progression. However, its biological significance in BTC has not been thoroughly investigated. In this research, we elucidated that circ_NRIP1 was notably overexpressed in both BTC tissues and cells. We further established a correlation between circ_NRIP1 expression and clinicopathological features in BTC patients, highlighting its clinical relevance. Through functional assays, we observed that knockdown of circ_NRIP1 significantly inhibited tumor cell proliferation, invasion, stemness maintenance, and epithelial-mesenchymal transition, indicating its active involvement in promoting BTC progression. Additionally, it attenuated growth of xenograft and metastasis models. Mechanically, we revealed that circ_NRIP1 served as the competing endogenous RNA to sequester miR-515-5p through complementary base pairing mechanism, thereby upregulated AKT2 expression and indirectly activated PI3K/AKT/mTOR signaling pathway. Generally, targeting the circ_NRIP1/miR-515-5p/AKT2 axis and aberrant activation of the PI3K/AKT/mTOR pathway may hold promising therapeutic strategies for BTC. Our research contributes to a better understanding of the underlying biological basis of BTC and paves the way for the development of innovative treatment approaches.

PG545 Prevents Osteoarthritis Development by Regulating PI3K/AKT/mTOR Signaling and Activating Chondrocyte Autophagy

INTRODUCTION

Osteoarthritis (OA) is a degenerative disease common in the elderly and is characterized by joint pain, swelling, and restricted movement. In recent years, heparanase has been reported to play an important role in the development of osteoarthritic cartilage. PG545 is a heparan sulfate mimetic with heparanase inhibitory activity. In this study, the therapeutic effects and possible mechanisms of PG545 were investigated in a chondrocyte injury model induced by interleukin-1β (IL -1β).

METHODS

Following treatment with PG545 or the autophagy inhibitor 3-methyladenine (3-MA), chondrocyte viability was detected using Cell Counting Kit-8 and fluorescein diacetate/propidium iodide double staining. The apoptosis rate of chondrocytes was determined by flow cytometry. Expression of light chain 3 and P62 was monitored by immunofluorescence labeling. Western blot, lentivirus infection with red fluorescent protein and green fluorescent protein, and quantitative real-time polymerase chain reaction were used to determine the expression levels of chondrocyte markers, apoptosis-related factors, autophagy proteins, and key proteins of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. The expression and activity of stress-specific enzymes such as malondialdehyde, superoxide dismutase, and catalase (CAT) were investigated. Chondrocytes with ATG5 knockdown were used to investigate the relationship between the therapeutic effect of PG545 and autophagy. The therapeutic effect of PG545 was verified in vivo.

RESULTS

PG545 had a significant protective effect on chondrocytes by reducing oxidative stress, apoptosis, and degradation of chondrocytes and increasing chondrocyte proliferation. PG545 was effective in inducing autophagy in IL-1β-treated cells, while 3-MA attenuated the effect. The PI3K/Akt/mTOR pathway may be involved in the promotion of autophagy and OA treatment by PG545.

CONCLUSION

PG545 was able to restore impaired autophagy and autophagic flux via the PI3K/Akt/mTOR pathway, thereby delaying the progression of OA, suggesting that PG545 may be a novel therapeutic approach for OA.

NQO1 drives glioblastoma cell aggressiveness through EMT induction via the PI3K/Akt/mTOR/Snail pathway

Glioblastoma multiforme (GBM) is the most frequent and lethal cancer derived from the central nervous system, of which the mesenchymal (MES) subtype seriously influences the survival and prognosis of patients. NAD(P)H: quinone acceptor oxidoreductase 1 (NQO1) serves an important role in the carcinogenesis and progression of various types of cancer; however, the specific mechanism underlying the regulatory effects of NQO1 on GBM is unclear. Thus, the present study aimed to explore the role and mechanism of NQO1 in GBM progression. The results of bioinformatics analysis and immunohistochemistry showed that high expression of NQO1 was significantly related to the MES phenotype of GBM and shorter survival. In addition, MTT, colony formation, immunofluorescence and western blot analyses, and lung metastasis model experiments suggested that silencing NQO1 inhibited the proliferation and metastasis of GBM cells in vitro and in vivo. Furthermore, western blotting showed that the activity of the PI3K/Akt/mTOR signaling pathway was revealed to be inhibited by downregulation of NQO1 expression, whereas it was enhanced by overexpression of NQO1. Notably, co‑immunoprecipitation and ubiquitination experiments suggested that Snail was considered an important downstream target of NQO1 in GBM cells. Snail knockdown could eliminate the promoting effect of ectopic NQO1 on the proliferation and invasion of GBM cells, and reduce its effects on the activity of PI3K/Akt/mTOR signaling pathway. These results indicated that NQO1 could promote GBM aggressiveness by activating the PI3K/Akt/mTOR signaling pathway in a Snail‑dependent manner, and NQO1 and its relevant pathways may be considered novel targets for GBM therapy.

MAOA suppresses the growth of gastric cancer by interacting with NDRG1 and regulating the Warburg effect through the PI3K/AKT/mTOR pathway

OBJECTIVE

Previous studies have indicated that neurotransmitters play important roles in the occurrence and development of gastric cancer. MAOA is an important catecholamine neurotransmitter-degrading enzyme involved in the degradation of norepinephrine, epinephrine and serotonin. To find a potential therapeutic target for the treatment of gastric cancer, the biological functions of MAOA and the underlying mechanism in gastric cancer need to be explored.

METHODS

The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) datasets, Kaplan‒Meier (KM) plotter were used to identify the differentially expressed genes, which mainly involved the degradation and synthesis enzymes of neurotransmitters in gastric cancer. We also investigated the expression pattern of MAOA in human and mouse tissues and cell lines by immunohistochemistry and Western blotting analysis. Western blotting, quantitative real-time PCR, enzyme-linked immunosorbent assay (ELISA) and a Seahorse experiment were used to identify the molecular mechanism of cancer cell glycolysis. MAOA expression and patient survival were analysed in the Ren Ji cohort, and univariate and multivariate analyses were performed based on the clinicopathological characteristics of the above samples.

RESULTS

MAOA expression was significantly downregulated in gastric cancer tissue and associated with poor patient prognosis. Moreover, the expression level of MAOA in gastric cancer tissue had a close negative correlation with the SUXmax value of PET-CT in patients. MAOA suppressed tumour growth and glycolysis and promoted cancer cell apoptosis. We also reported that MAOA can interact with NDRG1 and regulate glycolysis through suppression of the PI3K/Akt/mTOR pathway. MAOA expression may serve as an independent prognostic factor in gastric cancer patients.

CONCLUSIONS

MAOA attenuated glycolysis and inhibited the progression of gastric cancer through the PI3K/Akt/mTOR pathway. Loss of function or downregulation of MAOA can facilitate gastric cancer progression. Overexpression of MAOA and inhibition of the PI3K/Akt/mTOR pathway may provide a potential method for gastric cancer treatment in clinical therapeutic regimens.

Endometriosis-Associated Ovarian Carcinomas: How PI3K/AKT/mTOR Pathway Affects Their Pathogenesis

Ovarian clear cell (OCCC) and endometrioid (EnOC) carcinomas are often subsumed under the umbrella term "endometriosis-associated ovarian cancer" (EAOC), since they frequently arise from ectopic endometrium settled in the ovaries. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is known to be aberrantly activated both in endometriosis and EAOC; however, its role in the progression of endometriosis to ovarian cancer remains unclear. In fact, cancer-associated alterations in the mTOR pathway may be found in normal uterine epithelium, likely acting as a first step towards ovarian cancer, through the intermediary stage of endometriosis. This review aims to summarize the current knowledge regarding mTOR signaling dysregulation in the uterine endometrium, endometriosis, and EAOC while focusing on the interconnections between the PI3K/AKT/mTOR pathway and other signaling molecules that give rise to synergistic molecular mechanisms triggering ovarian cancer development in the presence of endometriosis.

hsa_circ_0000519 promotes the progression of lung adenocarcinoma through the hsa-miR-1296-5p/DARS axis

Emerging research indicates that circRNAs serve a crucial role in occurrence and development of cancers. This study aimed to uncover the biological role of hsa_circ_0000519 in the progression of LUAD (lung adenocarcinoma). hsa_circ_0000519 was identified by bioinformatic analysis, and its differential expression was validated in LUAD tissues and cell lines. CCK8, colony formation, wound healing, transwell assays, and xenograft tumor models were used to observe the biological functions of hsa_circ_0000519. FISH, RIP, dual luciferase reporter assays, and recovery experiments were implemented to explore the underlying mechanisms of hsa_circ_0000519. hsa_circ_0000519 was significantly upregulated in LUAD tissues and cell lines. The expression of hsa_circ_0000519 was positively correlated with T grade and TNM stage in patients with LUAD. Downregulation of hsa_circ_0000519 remarkably reduced cell proliferation, migration, invasion in vitro, and tumor growth in vivo. Mechanistic investigation demonstrated that hsa_circ_0000519 directly sponged hsa-miR-1296-5p to reduce its repressive impact on DARS as well as activate the PI3K/AKT/mTOR signaling pathway. The malignant phenotypes of LUAD cells induced by upregulation of hsa_circ_0000519 could be rescued by hsa-miR-1296-5p overexpression or knockdown of DARS. In conclusion, hsa_circ_0000519 promotes LUAD progression through the hsa-miR-1296-5p/DARS axis and may be expected as a novel biomarker and therapeutic for LUAD.

Selenium-binding protein 1 inhibits malignant progression and induces apoptosis via distinct mechanisms in non-small cell lung cancer

BACKGROUND

Selenium is an essential trace element in the human body. In epidemiological and clinical studies, Se supplementation significantly reduced the incidence of lung cancer in individuals with low baseline Se levels. The significant action of selenium is based on the selenium-containing protein as a mediator. Of note, the previous studies reported that the expression of selenium-binding protein 1 (SELENBP1) was obviously decreased in many human cancer tissues including non-small cell lung cancer (NSCLC). However, its roles in the origin and development of NSCLC are still unclear.

METHODS

The expression of SELENBP1 was measured by qRT-PCR, Western blotting and IHC in our collected clinical NSCLC tissues and cell lines. Next, the CCK-8, colony formation, wound-haeling, Millicell, Transwell, FCM assay, and in vivo xenograft model were performed to explore the function of SELENBP1 in NSCLC. The molecular mechanisms of SELENBP1 were investigated by Western blotting or IF assay.

RESULTS

We further identified that the expression of SELENBP1 was significantly decreased in NSCLC tissues in TCGA database and 45 out of 59 collected clinical NSCLC tissues compared with adjacent nontumor tissues, as well as in four NSCLC cell lines compared with normal lung cells. Particularly, we unexpectedly discovered that SELENBP1 was obviously expressed in alveolar type 2 (AT-II) cells for the first time. Then, a series of in vitro experiments uncovered that overexpression of SELENBP1 inhibited the proliferation, migration, and invasion of NSCLC cells, and induced cell apoptosis. Moreover, overexpression of SELENBP1 also inhibited growth and induced apoptosis of NSCLC cells in vivo. Mechanistically, we demonstrated that overexpression of SELENBP1 inhibited the malignant characteristics of NSCLC cells in part via inactivating the PI3K/AKT/mTOR signal pathway. Meanwhile, we found that overexpression of SELENBP1 inducing the apoptosis of NSCLC cells was associated with the activation of caspase-3 signaling pathway under nonhigh level of oxidative stress, but overexpression of SELENBP1 facilitating the cell apoptosis might be related to its combining with GPX1 and colocalizing in the nucleus under high level of oxidative stress.

CONCLUSIONS

Our findings highlighted that SELENBP1 was an important tumor suppressor during the origin and development of NSCLC. It may help to discover novel biomarkers or drug therapy targets for NSCLC.

FGF21 promotes angiotensin II-induced abdominal aortic aneurysm via PI3K/AKT/mTOR pathway

BACKGROUND

Abdominal aortic aneurysm (AAA) is a potentially fatal vascular disorder with a high mortality rate. It was previously reported that fibroblast growth factor 21 (FGF21) was highly expressed in AAA patients. Nonetheless, its underlying mechanism in AAA progression is unclarified.

METHODS

Angiotensin II (Ang-II) was used to induce AAA in human aortic vascular smooth muscle cells (HASMCs) and mouse models. Western blotting and RT-qPCR were utilized for measuring protein and RNA levels. Immunofluorescence staining was utilized for detecting LC3B expression in HASMCs. Elastica van Gieson staining was conducted for histological analysis of the abdominal aortas of mice.

RESULTS

FGF21 displayed a high level in Ang-II-stimulated HASMCs and AAA mice. FGF21 depletion ameliorated abdominal aorta dilation and Ang-II-triggered pathological changes in mice. FGF21 silencing hindered autophagy and PI3K/AKT/mTOR pathway.

CONCLUSIONS

FGF21 contributes to AAA progression by enhancing autophagy and activating PI3K/AKT/mTOR pathway.

Elucidating the Mechanism of Agrimonolide in Treating Colon Cancer Based on Network Pharmacology

Purpose

This study reported the efficacy and underlying mechanism of agrimonolide (AM) in treating colon cancer.

Methods

Colon cancer-AM-related targets were screened from online database. AM targets for colon cancer were identified by Venn diagram. Main molecular function, biological process, cellular component and pathways associated with AM targets for colon cancer were analyzed by GO and KEGG enrichment analysis. Relationship of the 10 core targets of AM for colon cancer with the top 15 BP and KEGG pathways was analyzed by Cytoscape software. A "component-target-pathway" network was constructed to select the hub genes of AM for colon cancer. AM effects on colon cancer cell viability, proliferation, invasion, migration and apoptosis were researched by CCK-8, colony formation, Transwell invasion, wound healing and flow cytometry assays. Tumor-bearing nude mice models were constructed and given AM treatment. Hub gene expression in cells/tissues was detected by Western blot.

Results

A total of 107 targets were selected as AM targets for colon cancer. The 10 core targets were related to the top 15 biological process terms and KEGG pathways. PI3K, AKT and mTOR were selected as the hub genes of AM for colon cancer. AM weakened colon cell proliferation, invasion, migration and apoptosis inhibition, and suppressed colon cell in vivo growth. AM up-regulated Caspase-3 and BAX proteins, down-regulated C-Myc, Cyclin D1 and BCL-2 proteins, and inactivated the PI3K/AKT/mTOR pathway both in vitro and in vivo.

Conclusion

AM suppressed colon cancer progression through inactivating the PI3K/AKT/mTOR pathway. It may be useful for colon cancer treatment.

The Role of Activation of PI3K/AKT/mTOR and RAF/MEK/ERK Pathways in Aggressive Pituitary Adenomas-New Potential Therapeutic Approach-A Systematic Review

Pituitary tumors (PT) are mostly benign, although occasionally they demonstrate aggressive behavior, invasion of surrounding tissues, rapid growth, resistance to conventional treatments, and multiple recurrences. The pathogenesis of PT is still not fully understood, and the factors responsible for its invasiveness, aggressiveness, and potential for metastasis are unknown. RAF/MEK/ERK and mTOR signaling are significant pathways in the regulation of cell growth, proliferation, and survival, its importance in tumorigenesis has been highlighted. The aim of our review is to determine the role of the activation of PI3K/AKT/mTOR and RAF/MEK/ERK pathways in the pathogenesis of pituitary tumors. Additionally, we evaluate their potential in a new therapeutic approach to provide alternative therapies and improved outcomes for patients with aggressive pituitary tumors that do not respond to standard treatment. We perform a systematic literature search using the PubMed, Embase, and Scopus databases (search date was 2012-2023). Out of the 529 screened studies, 13 met the inclusion criteria, 7 related to the PI3K/AKT/mTOR pathway, and 7 to the RAF/MEK/ERK pathway (one study was used in both analyses). Understanding the specific factors involved in PT tumorigenesis provides opportunities for targeted therapies. We also review the possible new targeted therapies and the use of mTOR inhibitors and TKI in PT management. Although the RAF/MEK/ERK and PI3K/AKT/mTOR pathways play a pivotal role in the complex signaling network along with many interactions, further research is urgently needed to clarify the exact functions and the underlying mechanisms of these signaling pathways in the pathogenesis of pituitary adenomas and their role in its invasiveness and aggressive clinical outcome.

LAMC2 regulates proliferation, migration, and invasion mediated by the Pl3K/AKT/mTOR pathway in oral

Background

Oral squamous cell carcinoma (OSCC) is a common malignant tumor. Recently, Laminin Gamma 2 (LAMC2) has been shown to be abnormally expressed in OSCC; however, how LAMC2 signaling contributes to the occurrence and development of OSCC and the role of autophagy in OSCC has not been fully explored. This study aimed to analyze the role and mechanism of LAMC2 signaling in OSCC and the involvement of autophagy in OSCC.

Methods

To explore the mechanism by which LAMC2 is highly expressed in OSCC, we used small interfering RNA (siRNA) to knock down LAMC2 to further observe the changes in the signaling pathway. Furthermore, we used cell proliferation assays, Transwell invasion assays, and wound-healing assays to observe the changes in OSCC proliferation, invasion, and metastasis. RFP-LC3 was used to detect the level of autophagy intensity. A cell line-derived xenograft (CDX) model was used to detect the effect of LAMC2 on tumor growth in vivo.

Results

This study found that the level of autophagy was correlated with the biological behavior of OSCC. The downregulation of LAMC2 activated autophagy and inhibited OSCC proliferation, invasion, and metastasis via inhibiting the PI3K/AKT/mTOR pathway. Moreover, autophagy has a dual effect on OSCC, and the synergistic downregulation of LAMC2 and autophagy can inhibit OSCC metastasis, invasion, and proliferation via the PI3K/AKT/mTOR pathway.

Conclusions

LAMC2 interacts with autophagy to regulate OSCC metastasis, invasion, and proliferation via the PI3K/AKT/mTOR pathway. LAMC2 down-regulation can synergistically modulate autophagy to inhibit OSCC migration, invasion, and proliferation.

Niclosamide causes lysosome-dependent cell death in endometrial cancer cells and tumors

Endometrial cancer is the most common female cancer showing continuous rise in its incidence and mortality rate. Despite the extensive research efforts in cancer therapeutics, still there is a lack of effective treatment options and the outcome is poor for patients with advanced and recurrent endometrial cancers. In this study, we aimed to evaluate the efficacy of niclosamide (NIC) against endometrial cancer. NIC is an FDA-approved anti-helminthic drug, which has been recently extensively studied as a potent anti-cancerous agent in several cancers. The anti-cancerous activity of NIC was analyzed in-vitro (ANC3A, Hec1B, and Ishikawa endometrial cancer cell lines) by cell viability-, soft agar-, invasion- and migration- assay. The action mechanism of NIC was demonstrated by western blot analysis and immune-fluorescence imaging and validated by specific inhibitors. The in-vivo efficacy of NIC was studied in the Ishikawa xenograft animal model. NIC effectively suppressed the viability (IC50<1 μM), colony formation ability, migration, and invasion of all endometrial cancer cells tested. We demonstrated that NIC inhibited AKT/mTOR signaling pathway and induced apoptosis and autophagy in endometrial cancer cells. Further study demonstrated that although NIC induced autophagosome formation, it inhibits autolysosome formation. In addition, we observed that NIC induced BAX co-localization with lysosome and inhibited Cathepsin B maturation from pro-cathepsin B, thereby inducing the lysosomal membrane permeability and release of hydrolytic enzymes from the lysosome to cytosol, which eventually contributed cell death. NIC also inhibited tumor weight and volume in the Ishikawa xenograft animal model without having any evidence of toxicity. Due to its potent anti-cancerous activity and safety profile, NIC seems to be a promising agent for human endometrial cancer therapeutics.

A study on the anti-osteoporosis mechanism of isopsoralen based on network pharmacology and molecular experiments

OBJECTIVE

Osteoporosis (OP) is a disease caused by multiple factors. Studies have pointed out that isopsoralen (IPRN) is one of the most effective drugs for the treatment of OP. Based on network pharmacological and molecular experimental analysis, the molecular mechanism of IPRN in osteoporosis is clarified.

METHODS

IPRN target genes and OP-related genes were predicted from the databases. Intersections were obtained and visualized. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on target genes, which was confirmed by experiments internal and external experiments. Molecular docking was used to verify the binding between IPRN and target proteins. Molecular dynamics (MD) simulates the binding affinity of protein targets and active compounds.

RESULTS

87 IPRN target genes and 242 disease-related targets were predicted. The protein-protein interaction (PPI) network identified 18 IPRN target proteins for the treatment of OP. GO analysis indicated that target genes were involved in biological processes. KEGG analysis showed that pathways such as PI3K/AKT/mTOR were associated with OP. Cell experiments (qPCR and WB) found that the expressions of PI3K, AKT, and mTOR in MC3T3-E1 cells at 10 μM, 20 μM, and 50 μM IPRN concentrations, especially at 20 μM IPRN treatment, were higher than those in the control group at 48 h. Animal experiments also showed that compared with the control group, 40 mg/kg/time IPRN could promote the expression of the PI3K gene in chondrocytes of SD rats.

CONCLUSIONS

This study predicted the target genes of IPRN in the treatment of OP and preliminarily verified that IPRN plays an anti-OP role through the PI3K/AKT/mTOR pathway, which provides a new drug for the treatment of OP.

G-protein signaling modulator 1 promotes colorectal cancer metastasis by PI3K/AKT/mTOR signaling and autophagy

BACKGROUND

Colorectal cancer is the second most common malignant tumor worldwide. A deeper insight into the mechanisms underlying colorectal cancer metastasis is urgently needed. G-protein signaling modulator 1 and autophagy play critical roles in tumor migration and invasion. However, the biological functions and regulatory networks of G-protein signaling modulator 1 and autophagy have not yet been fully studied.

METHODS

We performed immunohistochemistry and clinic-pathological characteristic analysis in 328 human colorectal cancer specimens to identify the clinical role of G-protein signaling modulator 1 in colorectal cancer. An in vitro coculture system and a tumor metastasis mouse model were used to explore the biological function of G-protein signaling modulator 1 on tumor metastasis. Autophagic flux detection like GFP-LC3B signal immunofluorescence and electron microscope observation of autophagic vesicles and confocal microscope detection were used to gain insights into the underlying role of G-protein signaling modulator 1 in autophagy.

RESULTS

We found that G-protein signaling modulator 1 was abundantly expressed in colorectal cancer tissues and was associated with lymph node metastasis and poor prognosis. Furthermore, our bioinformatic and functional studies demonstrated that G-protein signaling modulator 1 significantly promoted cell migration and invasion, both in vitro and in vivo. Mechanistically, we demonstrated that G-protein signaling modulator 1 could promote colorectal cancer cell migration and invasion and inhibit autophagy and by activating the PI3K/AKT/mTOR pathway.

CONCLUSIONS

We proposed that G-protein signaling modulator 1 promotes colorectal cancer metastasis by modulating autophagy through the PI3K/AKT/mTOR pathway.

[Research of epigallocatechin gallate in delaying chondrocyte senescence]

Objective

To investigate the effect of epigallocatechin gallate (EGCG) on chondrocyte senescence and its mechanism.

Methods

The chondrocytes were isolated from the articular cartilage of 4-week-old Sprague Dawley rats, and cultured with type Ⅱcollagenase and passaged. The cells were identified by toluidine blue staining, alcian blue staining, and immunocytochemical staining for type Ⅱ collagen. The second passage (P2) cells were divided into blank control group, 10 ng/mL IL-1β group, and 6.25, 12.5, 25.0, 50.0, 100.0, and 200.0 μmol/L EGCG+10 ng/mL IL-1β group. The chondrocyte activity was measured with cell counting kit 8 after 24 hours of corresponding culture, and the optimal drug concentration of EGCG was selected for the subsequent experiment. The P2 chondrocytes were further divided into blank control group (group A), 10 ng/mL IL-1β group (group B), EGCG+10 ng/mL IL-1β group (group C), and EGCG+10 ng/mL IL-1β+5 mmol/L 3-methyladenine (3-MA) group (group D). After cultured, the degree of cell senescence was detected by β-galactosidase staining, the autophagy by monodansylcadaverine method, and the expression levels of chondrocyte-related genes [type Ⅱ collagen, matrix metalloproteinase 3 (MMP-3), MMP-13] by real-time fluorescent quantitative PCR, the expression levels of chondrocyte-related proteins (Beclin-1, LC3, MMP-3, MMP-13, type Ⅱ collagen, P16, mTOR, AKT) by Western blot.

Results

The cultured cells were identified as chondrocytes. Compared with the blank control group, the cell activity of 10 ng/mL IL-1β group significantly decreased ( P<0.05). Compared with the 10 ng/mL IL-1β group, the cell activity of EGCG+10 ng/mL IL-1β groups increased, and the 50.0, 100.0, and 200.0 μmol/L EGCG significantly promoted the activity of chondrocytes ( P<0.05). The 100.0 μmol/L EGCG was selected for subsequent experiments. Compared with group A, the cells in group B showed senescence changes. Compared with group B, the senescence rate of chondrocytes in group C decreased, autophagy increased, the relative expression of type Ⅱ collagen mRNA increased, and relative expressions of MMP-3 and MMP-13 mRNAs decreased; the relative expressions of Beclin-1, LC3, and type Ⅱ collagen proteins increased, but the relative expressions of P16, MMP-3, MMP-13, mTOR, and AKT proteins decreased; the above differences were significant ( P<0.05). Compared with group C, when 3-MA was added in group D, the senescence rate of chondrocytes increased, autophagy decreased, and the relative expressions of the target proteins and mRNAs showed an opposite trend ( P<0.05).

Conclusion

EGCG regulates the autophagy of chondrocytes through the PI3K/AKT/mTOR signaling pathway and exerts anti-senescence effects.

Effect of STK3 on proliferation and apoptosis of pancreatic cancer cells via PI3K/AKT/mTOR pathway

Pancreatic cancer, as a malignant tumor with a very poor prognosis, has a high mortality. It is imperative to clarify the mechanism of pancreatic cancer development and find suitable targets for diagnosis and treatment. Serine/threonine kinase 3 (STK3) is one of the core kinases of the Hippo pathway and has the ability to inhibit tumor growth. But the biological function of STK3 in pancreatic cancer remains unknown. Here, we confirmed that STK3 has an impact on the growth, apoptosis, and metastasis of pancreatic cancer cells and investigated the related molecular mechanisms. In our research, we found that STK3 is reduced in pancreatic cancer by RT-qPCR, IHC and IF, its expression level is correlated with the clinicopathological features. CCK-8 assay, colony formation assay and flow cytometry were used to detect the effect of STK3 on the proliferation and apoptosis of pancreatic cancer cells. In addition, the Transwell assay was used to detect the ability of cell migration and invasion. The results showed that STK3 promoted apoptosis and inhibited cell migration, invasion and proliferation in pancreatic cancer. Gene set enrichment analysis (GSEA) and western blotting are used to predict and verify the pathways related to STK3. Subsequently, we found that the effect of STK3 on proliferation and apoptosis is closely related to the PI3K/AKT/mTOR pathway. Moreover, the assistance of RASSF1 plays a significant role in the regulation of PI3K/AKT/mTOR pathway by STK3. The nude mouse xenograft experiment demonstrated the tumor suppressive ability of STK3 in vivo. Collectively, this study found that STK3 regulates pancreatic cancer cell proliferation and apoptosis by suppressing the PI3K/AKT/mTOR pathway with the assistance of RASSF1.

Ampelopsin induces MDA-MB-231 cell cycle arrest through cyclin B1-mediated PI3K/AKT/mTOR pathway in vitro and in vivo

Breast cancer is one of the most common malignant tumors in women and it is the most frequently diagnosed cancer in the world. Ampelopsin (AMP) is a purified component from the root of Ampelopsis grossedentata. It is reported that AMP could significantly inhibit the proliferation of breast cancer cells. However, the antitumor mechanism against breast cancer has not yet been fully elucidated. The purpose of this work was to study the role of AMP against breast cancer MDA-MB-231 cells and to further investigate the underlying mechanism. PI3K/AKT/mTOR plays a very important role in tumor cell growth and proliferation and we hypothesize that AMP may inhibit this pathway. In the present work, the results showed that AMP could significantly inhibit the growth of breast cancer MDA-MB-231 cells in vitro and in vivo. In addition, treatment with AMP decreased the levels of PI3K, AKT and mTOR, as well as cyclin B1 expression, followed by p53/p21 pathway activation to arrest the cell cycle at G2/M. Moreover, it demonstrated a positive association between cyclin B1 and PI3K/AKT/mTOR levels. Importantly, this pathway was found to be regulated by cyclin B1 in MDA-MB-231 cells treated with AMP. Also, it was observed that cyclin B1 overexpression attenuated cell apoptosis and weakened the inhibitory effects of AMP on cell proliferation. Together, AMP could inhibit breast cancer MDA-MB-231 cell proliferation in vitro and in vivo, due to cell cycle arrest at G2/M by inactivating PI3K/AKT/mTOR pathway regulated by cyclin B1.

Drugging the PI3K/AKT/mTOR Pathway in ER+ Breast Cancer

The frequent activation of the PI3K/AKT/mTOR pathway and its crucial role in estrogen receptor-positive (ER+) breast cancer tumorigenesis and drug resistance has made it a highly attractive therapeutic target in this breast cancer subtype. Consequently, the number of new inhibitors in clinical development targeting this pathway has drastically increased. Among these, the PIK3CA isoform-specific inhibitor alpelisib and the pan-AKT inhibitor capivasertib were recently approved in combination with the estrogen receptor degrader fulvestrant for the treatment of ER+ advanced breast cancer after progression on an aromatase inhibitor. Nevertheless, the clinical development of multiple inhibitors of the PI3K/AKT/mTOR pathway, in parallel with the incorporation of CDK4/6 inhibitors into the standard of care treatment in ER+ advanced breast cancer, has led to a multitude of available therapeutic agents and many possible combined strategies which complicate personalizing treatment. Here, we review the role of the PI3K/AKT/mTOR pathway in ER+ advanced breast cancer, highlighting the genomic contexts in which the various inhibitors of this pathway may have superior activity. We also discuss selected trials with agents targeting the PI3K/AKT/mTOR and related pathways as well as the rationale supporting the clinical development of triple combination therapy targeting ER, CDK4/6 and PI3K/AKT/mTOR in ER+ advanced breast cancer.

MicroRNA-494 regulates high glucose-induced cardiomyocyte apoptosis and autophagy by PI3K/AKT/mTOR signalling pathway

AIMS

Diabetic cardiomyopathy (DCM) is one of the major cardiovascular complications of diabetes. However, the mechanism of DCM is not fully understood. Studies have confirmed that certain microRNAs (miRNAs/miRs) are key regulators of DCM. The aim of this study was to investigate the role and mechanism of microRNA (miR)-494 in cardiomyocyte apoptosis and autophagy induced by high glucose (HG).

METHODS AND RESULTS

By establishing a rat DCM model and an HG-treated H9c2 cells injury model, cardiac function was detected by echocardiography, myocardial tissue was stained by immunohistochemistry, and Cell Counting Kit-8 assay and lactate dehydrogenase assay were used to detect the cardiomyocyte injury. Cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling staining, and western blotting was used to detect death and autophagy. The results showed that the expression level of miR-494 was higher in the myocardial tissue of DCM rats and the myocardial cells of H9c2 treated with HG. Compared with the corresponding negative control groups, miR-494 mimics enhanced HG-induced apoptosis and autophagy, whereas miR-494 inhibitors showed the opposite effect, corresponding PI3K, AKT, and mTOR phosphorylation level has changed.

CONCLUSIONS

These findings identify that miR-494 could regulate cell apoptosis and autophagy through PI3K/AKT/mTOR signalling pathway, participating in the regulation of cardiomyocyte cell damage after HG. These findings provide new insights for the further study of the molecular mechanism and treatment of DCM.

Mechanism of Sijunzi Decoction in the treatment of colorectal cancer based on network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Sijunzi Decoction（SJZD）, as a famous classical prescription for the treatment of colorectal cancer(CRC) in the traditional Chinese medicine (TCM), has achieved good curative effects in clinical practice. However, its specific ingredients and molecular mechanisms is still unclear.

AIM OF THE STUDY

To analyze the effective ingredients and molecular mechanisms of SJZD in the treatment of CRC through network pharmacology technology and experimental validation.

MATERIALS AND METHODS

First, the TCM Systems Pharmacology database and analysis platform database were searched to screen the effective chemical components of SJZD. Swiss Target Prediction was used to predict corresponding potential target genes of compounds. After that, we constructed a components and corresponding target network by Cytoscape. Simultaneously, 5 disease databases were used to search and filter CRC targets, and then we constructed a drug-disease target protein-protein interaction (PPI) network. Cytoscape 3.7 was used for visualization and cluster analysis, and Metascape database was used for GO and KEGG enrichment analysis. We drew the main pathway-target network diagram. Autodock vina1.5.6 was applied to molecular docking for the main compounds and target proteins. Subsequently, the potential mechanism of SJZD on colon cancer predicted by network pharmacological analysis was experimentally studied and verified in vivo and in vitro.

RESULTS

144 effective active chemical components, 897 potential targets, and 2584 CRC target genes were screened out. The number of common targets between the SJZD and CRC was 414.3250 GO biological process items and 186 KEGG signal pathways were obtained after analysis. The main compounds and the target protein had a good binding ability in molecular docking. The results of cell and animal experiments showed that SJZD could promote apoptosis and autophagy of CRC cells through PI3K/Akt/mTOR pathway.

CONCLUSIONS

SJZD can treat CRC through multiple components, multiple targets and multiple pathways. We initially revealed the effective components and molecular mechanisms of SJZD in the treatment of CRC, and we used molecular docking and experiment for preliminary verification.

Chemokine-like receptor 1 deficiency impedes macrophage phenotypic transformation and cardiac repair after myocardial infarction

BACKGROUND

Timely and appropriate transformation of macrophage phenotypes from proinflammatory to anti-inflammatory is essential for cardiac repair after myocardial infarction (MI). Chemokine-like receptor 1 (CMKLR1), which is expressed on macrophages, is regulated by proinflammatory and anti-inflammatory stimuli. However, the contribution of CMKLR1 to macrophage phenotypic transformation and the role it plays in modulating cardiac repair after MI remain unclear.

METHODS

CMKLR1 knockout (CMKLR1-/-) mice were generated by CRISPR/Cas-mediated genome engineering. A model of murine MI was induced by permanent ligation along the left anterior descending artery. Cardiac function was evaluated by echocardiography. Infarct size and collagen deposition were detected by Masson's trichrome staining. Cardiac macrophages were obtained by fluorescence-activated cell sorting. The protein and mRNA expression of associated molecules was determined by Western blotting and qRT-PCR.

RESULTS

We demonstrated that macrophages highly expressed CMKLR1 and accumulated in murine infarcted hearts during the anti-inflammatory reparative phase of MI. CMKLR1 deficiency impaired cardiac function, increased infarct size, induced maladaptive cardiac remodeling, and decreased long-term survival after MI. Furthermore, CMKLR1 deficiency impeded macrophage phenotypic transformation from M1 to M2 in vivo and in vitro. In addition, we demonstrated that CMKLR1 signaling through the PI3K/Akt/mTOR pathway stimulated C/EBPβ activation while simultaneously limiting NF-κB activation, thereby promoting anti-inflammatory and prohibiting proinflammatory macrophage polarization.

CONCLUSIONS

Our results reveal that CMKLR1 deficiency impedes macrophage phenotypic transformation and cardiac repair after MI involving the PI3K/AKT/mTOR pathway. CMKLR1 may thus represent a potential therapeutic target for MI.

S100A6 promotes the development of thyroid cancer and inhibits apoptosis of thyroid cancer cells through the PI3K/AKT/mTOR pathway

High levels of S100A6 have been associated with progression in some types of human cancers. Cancers related to S100A6 have been reported to include lung cancer, cervical cancer, pancreatic cancer, gastric cancer, colon cancer, etc., but its role in the molecular pathogenesis of these cancers is largely unknown. This study investigated the expression and functional roles of S100A6 in human thyroid cancer. The expression level of S100A6 in thyroid cancer cells was determined by bioinformatics and transcriptomic analysis. Furthermore, the potential functions of S100A6 in tumorigenesis were analyzed by cell proliferation, migration, invasion, and Western blot assays in human thyroid cancer cells. Public database queries revealed high S100A6 expression in thyroid cancer. In addition, we also found that high expression of S100A6 was positively correlated with malignant clinicopathological characteristics of thyroid cancer in The Cancer Genome Atlas database. qPCR results confirmed the high expression of S100A6 in thyroid cancer cells. S100A6 silencing inhibited cell proliferation, migration, and invasion. Western blot assays and response experiments showed that S100A6 promotes cell proliferation and tumorigenicity partly through the PI3K/AKT/mTOR signaling pathway. These results suggest that S100A6 affects the progression of thyroid cancer and can be used as a target in the future treatment of thyroid cancer.

Sirt3 activates autophagy to prevent DOX-induced senescence by inactivating PI3K/AKT/mTOR pathway in A549 cells

Sirtuin 3 (Sirt3), a mitochondrial deacetylase, regulates mitochondrial redox homeostasis and autophagy and is involved in physiological and pathological processes such as aging, cellular metabolism, and tumorigenesis. We here investigate how Sirt3 regulates doxorubicin (DOX)-induced senescence in lung cancer A549 cells. Sirt3 greatly reduced DOX-induced upregulation of senescence marker proteins p53, p16, p21 and SA-β-Gal activity as well as ROS levels. Notably, Sirt3 reversed DOX-induced autophagic flux blockage, as shown by increased p62 degradation and LC3II/LC3I ratio. Importantly, the autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) partially abolished the antioxidant stress and antiaging effects of Sirt3, while the autophagy activator rapamycin (Rap) potentiated these effects of Sirt3, demonstrating that autophagy mediates the anti-aging effects of Sirt3. Additionally, Sirt3 inhibited the DOX-induced activation of the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway, which in turn activated autophagy. The PI3K inhibitor LY294002 promoted the antioxidant stress and antiaging effects of Sirt3, while the AKT activator SC-79 reversed these effects of Sirt3. Taken together, Sirt3 counteracts DOX-induced senescence by improving autophagic flux.

Sirt3 activates autophagy to prevent DOX-induced senescence by inactivating PI3K/AKT/mTOR pathway in A549 cells

Sirtuin 3 (Sirt3), a mitochondrial deacetylase, regulates mitochondrial redox homeostasis and autophagy and is involved in physiological and pathological processes such as aging, cellular metabolism, and tumorigenesis. We here investigate how Sirt3 regulates doxorubicin (DOX)-induced senescence in lung cancer A549 cells. Sirt3 greatly reduced DOX-induced upregulation of senescence marker proteins p53, p16, p21 and SA-β-Gal activity as well as ROS levels. Notably, Sirt3 reversed DOX-induced autophagic flux blockage, as shown by increased p62 degradation and LC3II/LC3I ratio. Importantly, the autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) partially abolished the antioxidant stress and antiaging effects of Sirt3, while the autophagy activator rapamycin (Rap) potentiated these effects of Sirt3, demonstrating that autophagy mediates the anti-aging effects of Sirt3. Additionally, Sirt3 inhibited the DOX-induced activation of the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway, which in turn activated autophagy. The PI3K inhibitor LY294002 promoted the antioxidant stress and antiaging effects of Sirt3, while the AKT activator SC-79 reversed these effects of Sirt3. Taken together, Sirt3 counteracts DOX-induced senescence by improving autophagic flux.