The Two-Faced Role of Autophagy in Endometrial Cancer

SIRT1-mediated deacetylation of FOXO3 enhances mitophagy and drives hormone resistance in endometrial cancer

BACKGROUND

The complex interplay between Sirtuin 1 (SIRT1) and FOXO3 in endometrial cancer (EC) remains understudied. This research aims to unravel the interactions of deacetylase SIRT1 and transcription factor FOXO3 in EC, focusing on their impact on mitophagy and hormone resistance.

METHODS

High-throughput sequencing, cell experiments, and bioinformatics tools were employed to investigate the roles and interactions of SIRT1 and FOXO3 in EC. Co-immunoprecipitation (Co-IP) assay was used to assess the interaction between SIRT1 and FOXO3 in RL95-2 cells. Functional assays were used to assess cell viability, proliferation, migration, invasion, apoptosis, and the expression of related genes and proteins. A mouse model of EC was established to evaluate tumor growth and hormone resistance under different interventions. Immunohistochemistry and TUNEL assays were used to assess protein expression and apoptosis in tumor tissues.

RESULTS

High-throughput transcriptome sequencing revealed a close association between SIRT1, FOXO3, and EC development. Co-IP showed a protein-protein interaction between SIRT1 and FOXO3. Overexpression of SIRT1 enhanced FOXO3 deacetylation and activity, promoting BNIP3 transcription and PINK1/Parkin-mediated mitophagy, which in turn promoted cell proliferation, migration, invasion, and inhibited apoptosis in vitro, as well as increased tumor growth and hormone resistance in vivo. These findings highlighted SIRT1 as an upstream regulator and potential therapeutic target in EC.

CONCLUSION

This study reveals a novel molecular mechanism underlying the functional relevance of SIRT1 in regulating mitophagy and hormone resistance through the deacetylation of FOXO3 in EC, thereby providing valuable insights for new therapeutic strategies.

Invasion of human dental pulp fibroblasts by Porphyromonas gingivalis leads to autophagy via the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin signaling pathway

OBJECTIVES

Porphyromonas gingivalis is a pathogenic bacterium that causes periodontitis and dental pulp infection. Autophagy is a potential mechanism involved in inflammatory disease. This study established an in vitro model of P. gingivalis intracellular infection in human dental pulp fibroblasts (HDPFs) to investigate the effects of live P. gingivalis on HDPFs.

METHODS

Morphological and quantification techniques such as fluorescence microscopy, transmission electron microscopy (TEM), indirect immunofluorescence analysis, enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (PCR), and western blotting were used in this study.

RESULTS

After cell invasion, P. gingivalis is mainly localized in the cytoplasm and lysosomes. Additionally, P. gingivalis activates autophagy in HDPFs by upregulating the expression of autophagy-related gene Beclin-1, activate autophagy-related gene12 (ATG12), and microtubule-associated protein light chain 3 (LC3). Furthermore, the invasion of P. gingivalis leads to increased phosphorylation of PI3K, Akt, and mTOR with the addition of rapamycin, whereas the addition of wortmannin decreased phosphorylation. This invasion of P. gingivalis, also causes an inflammatory response, leading to the upregulation of IL-1β, IL-6, and TNF-α. Rapamycin helps decrease levels of pro-inflammatory cytokines, but the addition of wortmannin increases them. These results show that the invasion of P. gingivalis can cause excessive inflammation and promote the autophagy of HDPFs, which is regulated by PI3K/Akt/mTOR.

CONCLUSIONS

P. gingivalis escapes the immune system by inducing autophagy in the host cells, causing excessive inflammation. P. gingivalis regulates autophagy in HDPFs through the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin pathway.

Mechanism of Paris polyphylla saponin II inducing autophagic to inhibit angiogenesis of cervical cancer

Paris polyphylla saponin II (PPII) has good biological activity in inhibiting tumor angiogenesis. However, the mechanism of its action is still unclear. This study first observed the inhibitory effect of PPII on cervical cancer cells (Hela) through the establishment of MTT and nude mouse subcutaneous transplantation tumor models. Afterwards, then, we collected Hela cell supernatant for culturing HUVEC cells and treated it with PPII. Observe the invasion, migration, and lumen formation ability of drugs through Transwell, cell scratch test, and angiogenesis experiment. MDC staining was used to observe positive staining in the perinuclear area, AO staining was used to observe acidic areas, and transmission electron microscopy staining was used to observe ultrastructure and autophagy. In addition, the effects of PPII on autophagy- and angiogenesis-related protein expression were detected by Western blotting and quantitative reverse transcriptase polymerase chain reaction. Finally, HUVECs were treated with autophagy inhibitors 3-MA, CQ, and PI3K inhibitor LY294002, respectively. The results showed that the autophagy level of cells treated with PPII was significantly increased. In addition, adding autophagy inhibitors can effectively inhibit angiogenesis in cervical cancer. Further research suggests that PPII induces autophagy in HUVEC cells by regulating the PI3K/AKT/mTOR signaling pathway, thereby affecting angiogenesis and inhibiting Hela cell proliferation, lumen formation, invasion, and migration.

Advances in research on autophagy mechanisms in resistance to endometrial cancer treatment

Administering medication is a crucial strategy in improving the prognosis for advanced endometrial cancer. However, the rise of drug resistance often leads to the resurgence of cancer or less-than-ideal treatment outcomes. Prior studies have shown that autophagy plays a dual role in the development and progression of endometrial cancer, closely associated with drug resistance. As a result, concentrating on autophagy and its combination with medical treatments might be a novel approach to improve the prognosis for endometrial cancer. This study explores the impact of autophagy on drug resistance in endometrial cancer, investigates its core mechanisms, and scrutinizes relevant treatments aimed at autophagy, aiming to illuminate the issue of treatment resistance in advanced endometrial cancer.

β-catenin inhibitor ICG-001 suppress cell cycle progression and induce autophagy in endometrial cancer cells

The incidence of endometrial cancer has been rising in recent years. Gene mutation and high protein expression of β-catenin are commonly detected in endometrioid endometrial cancer. ICG-001 is a β-catenin inhibitor via blocking the complex formation of β-catenin and cAMP response element-binding protein (CREB)-binding protein (CBP). This study aims to investigate the effect of ICG-001 on endometrial cancer inhibition. First, endometrial carcinoma patient-derived xenograft (PDX)-derived organoids and primary cells were used to verify the inhibiting ability of ICG-001 on endometrial cancer. Furthermore, endometrial cancer cell lines were used to investigate the anticancer mechanism of ICG-001. Using MTT assay and tumor spheroid formation assay, ICG-001 significantly reduced the cell viability of HEC-59 and HEC-1A cells. ICG-001 enhanced cisplatin-mediated cytotoxicity. ICG-001 decreased cancer stem cell sphere formation. ICG-001 decreased the protein expressions of CD44, hexokinase 2 (HK2), and cyclin A. ICG-001 lowered the cell cycle progression by flow cytometer analysis. Autophagy, but no apoptosis, was activated by ICG-001 in endometrial cancer cells. Autophagy inhibition by ATG5 silencing enhanced ICG-001-mediated suppression of cell viability, tumor spheroid formation, and protein expression of cyclin A and CD44. This study clarified the mechanism and revealed the clinical potential of ICG-001 against endometrial cancer.

Association of Membranous WNT-1 and Nuclear mTOR with Endometrial Cancer Grade

Endometrial cancer remains a common cancer affecting the female reproductive system. There is still a need for more efficient ways of determining the degree of malignancy and optimizing treatment. WNT and mTOR are components of signaling pathways within tumor cells, and dysfunction of either protein is associated with the pathogenesis of neoplasms. Therefore, the aim of our study was to assess the impact of subcellular WNT-1 and mTOR levels on the clinical course of endometrial cancer. WNT-1 and mTOR levels in the plasma membrane, nucleus, and cytoplasm were evaluated using immunohistochemical staining in a group of 64 patients with endometrial cancer of grades 1-3 and FIGO stages I-IV. We discovered that the levels of WNT-1 and mTOR expression in the cellular compartments were associated with tumor grade and staging. Membranous WNT-1 was negatively associated, whereas cytoplasmic WNT-1 and nuclear mTOR were positively associated with higher grading of endometrial cancer. Furthermore, nuclear mTOR was positively associated with FIGO stages IB-IV. To conclude, we found that the assessment of WNT-1 in the cell membrane may be useful for exclusion of grade 3 neoplasms, whereas cytoplasmic WNT-1 and nuclear mTOR may be used as indicators for confirmation of grade 3 neoplasms.

Pre-clinical and clinical importance of miR-21 in human cancers: Tumorigenesis, therapy response, delivery approaches and targeting agents

The field of non-coding RNA (ncRNA) has made significant progress in understanding the pathogenesis of diseases and has broadened our knowledge towards their targeting, especially in cancer therapy. ncRNAs are a large family of RNAs with microRNAs (miRNAs) being one kind of endogenous RNA which lack encoded proteins. By now, miRNAs have been well-coined in pathogenesis and development of cancer. The current review focuses on the role of miR-21 in cancers and its association with tumor progression. miR-21 has both oncogenic and onco-suppressor functions and most of the experiments are in agreement with the tumor-promoting function of this miRNA. miR-21 primarily decreases PTEN expression to induce PI3K/Akt signaling in cancer progression. Overexpression of miR-21 inhibits apoptosis and is vital for inducing pro-survival autophagy. miR-21 is vital for metabolic reprogramming and can induce glycolysis to enhance tumor progression. miR-21 stimulates EMT mechanisms and increases expression of MMP-2 and MMP-9 thereby elevating tumor metastasis. miR-21 is a target of anti-cancer agents such as curcumin and curcumol and its down-regulation impairs tumor progression. Upregulation of miR-21 results in cancer resistance to chemotherapy and radiotherapy. Increasing evidence has revealed the role of miR-21 as a biomarker as it is present in both the serum and exosomes making them beneficial biomarkers for non-invasive diagnosis of cancer.

Danshen injection induces autophagy in podocytes to alleviate nephrotic syndrome via the PI3K/AKT/mTOR pathway

BACKGROUND

Danshen injection (DSI) is an agent extracted from the Salvia miltiorrhiza Bunge, a natural drug commonly used to alleviate kidney diseases. However, the material basis and therapeutic effects of DSI on nephrotic syndrome (NS) remain unclear.

PURPOSE

To investigate the material basis of DSI and the therapeutic effects and underlying mechanisms of NS.

METHODS

NS models were established using adriamycin-induced BALB/c mice and lipopolysaccharide-induced mouse podocytes (MPC-5). Following DSI and prednisone administration, kidney coefficients, 24 h urine protein, blood urea nitrogen, and serum creatinine levels were tested. Histomorphology was observed by periodic acid-Schiff staining and hematoxylin and eosin staining of the kidney sections. The glomerular basement membrane and autophagosomes of the kidneys were observed using transmission electron microscopy. Nephrin and desmin levels in the glomeruli were tested using immunohistochemistry. The viability of MPC-5 cells was tested using cell counting kit-8 after chloroquine and rapamycin administration in combination with DSI. The in vivo and in vitro protein levels of phosphatidylinositol 3-kinase (PI3K), AKT, phosphorylated AKT (Ser473), mammalian target of rapamycin (mTOR), microtubule-associated protein light chain 3 (LC3), beclin1, cleaved caspase-3, and caspase-3 were detected using western blotting.

RESULTS

Our results showed that DSI contained nine main components: caffeic acid, danshensu, lithospermic acid, rosmarinic acid, salvianolic acid A, salvianolic acid B, salvianolic acid C, salvianolic acid D, and 3, 4-Dihydroxybenzaldehyde. In in vivo studies, the NS mice showed renal function and pathological impairment. Podocytes were damaged, with decreased levels of autophagy and apoptosis, accompanied by inhibition of the PI3K/AKT/mTOR signaling. DSI administration resulted in improved renal function and pathology in NS mice, with the activation of autophagy and PI3K/AKT/mTOR signaling in the kidneys. Additionally, podocytes were less damaged and intracellular autophagosomes were markedly increased. In vitro studies have shown that DSI activated MPC-5 autophagy and reduced apoptosis via the PI3K/AKT/mTOR pathway.

CONCLUSION

Collectively, this study demonstrated that DSI activated podocyte autophagy and reduced apoptosis via the PI3K/AKT/mTOR signaling, ultimately attenuating NS. Our study clarified the main components of DSI and elucidated its therapeutic effects and potential mechanisms for NS, providing new targets and agents for the clinical treatment of NS.