Parkin-mediated mitophagy is a potential treatment for oxaliplatin-induced peripheral neuropathy.

Oxaliplatin-induced peripheral nerve pain (OIPNP) is a common chemotherapy-related complication, but the mechanism is complex. Mitochondria are vital for cellular homeostasis and regulating oxidative stress. Parkin-mediated mitophagy is a cellular process that removes damaged mitochondria, exhibiting a protective effect in various diseases; however, its role in OIPNP remains unclear. In this study, we found that Parkin-mediated mitophagy was decreased, and reactive oxygen species (ROS) was upregulated in OIPNP rat dorsal root ganglion (DRG) in vivo and in PC12 cells stimulated with oxaliplatin (OXA) in vitro. Overexpression of Parkin indicated that OXA might cause mitochondrial and cell damage by inhibiting mitophagy. We also showed that salidroside (SAL) upregulated Parkin-mediated mitophagy to eliminate damaged mitochondria and promote PC12 cell survival. Knockdown of Parkin indicated that mitophagy is crucial for apoptosis and mitochondrial homeostasis in PC12 cells. In vivo study also demonstrated that SAL enhances Parkin-mediated mitophagy in the DRG and alleviates peripheral nerve injury and pain. These results suggest that Parkin-mediated mitophagy is involved in the pathogenesis of OIPNP and may be a potential therapeutic target for OIPNP.NEW & NOTEWORTHY This article discusses the effects and mechanisms of Parkin-mediated mitophagy in oxaliplatin-induced peripheral nerve pain (OIPNP) from both in vivo and in vitro. We believe that our study makes a significant contribution to the literature because OIPNP has always been the focus of clinical medicine, and mitochondrial quality regulation mechanisms especially Parkin-mediated mitophagy, have been deeply studied in recent years. We use a variety of molecular biological techniques and animal experiments to support our argument.

The oncogenic role and regulatory mechanism of ACAA2 in human ovarian cancer.

Acetyl-CoAacyltransferase2 (ACAA2) is a key enzyme in the fatty acid oxidation pathway that catalyzes the final step of mitochondrial ß oxidation, which plays an important role in fatty acid metabolism. The expression of ACAA2 is closely related to the occurrence and malignant progression of tumors. However, the function of ACAA2 in ovarian cancer is unclear. The expression level and prognostic value of ACAA2 were analyzed by databases. Gain and loss of function were carried out to explore the function of ACAA2 in ovarian cancer. RNA-seq and bioinformatics methods were applied to illustrate the regulatory mechanism of ACAA2. ACAA2 overexpression promoted the growth, proliferation, migration, and invasion of ovarian cancer, and ACAA2 knockdown inhibited the malignant progression of ovarian cancer as well as the ability of subcutaneous tumor formation in nude mice. At the same time, we found that OGT can induce glycosylation modification of ACAA2 and regulate the karyoplasmic distribution of ACAA2. OGT plays a vital role in ovarian cancer as a function of oncogenes. In addition, through RNA-seq sequencing, we found that ACAA2 regulates the expression of DIXDC1. ACAA2 regulated the malignant progression of ovarian cancer through the WNT/ß-Catenin signaling pathway probably. ACAA2 is an oncogene in ovarian cancer and has the potential to be a target for ovarian cancer therapy.

GSDMD mediated pyroptosis induced inflammation of Graves' orbitopathy via the NF-κB/ AIM2/ Caspase-1 pathway.

Gasdermin D (GSDMD) is a key executor which triggers pyroptosis as well as an attractive checkpoint in various inflammatory and autoimmune diseases but it has yet to prove its function in Graves'orbitopathy (GO). Our aim was to investigate GSDMD levels in orbital connective tissue and serum of GO patients and then assess the association between serum levels and patients' clinical activity score (CAS). Further, GSDMD-mediated pyroptosis and the underlying mechanism in inflammatory pathogenesis in the cultured orbital fibroblasts (OFs) of GO patients were examined. OFs were collected after tumor necrosis factor (TNF)-α or interferon (IFN)-γ treatment or combination treatment at different times, and the expression of GSDMD and related molecular mechanisms were analyzed. Then, we constructed the GSDMD knockout system with siRNA and the system was further exposed to the medium with or without IFN-γ and TNF-α for a specified time. Finally, we evaluated the production of interleukin (IL)-1ß and IL-18. We found that serum GSDMD levels were elevated and positively correlated with the CAS in GO patients. Meanwhile, the expression of GSDMD and N-terminal domain (NT-GSDMD) in orbital connective tissue of GO patients was augmented. Also, increased expression of GSDMD and related pyroptosis factors was observed in vitro model of GO. We further demonstrated that GSDMD-mediated pyroptosis induced inflammation via the nuclear factor kB (NF-κB)/absent in melanoma-2 (AIM-2)/caspase-1 pathway. In addition, blocking GSDMD suppressed proinflammatory cytokine production in GO. We concluded that GSDMD may be a biomarker as well as a potential target for the evaluation and treatment of inflammation related with GO.

Impact of setup errors on the robustness of linac-based single-isocenter coplanar and non-coplanar VMAT plans for multiple brain metastases.

PURPOSE: Patient setup errors have been a primary concern impacting the dose delivery accuracy in radiation therapy. A robust treatment plan might mitigate the effects of patient setup errors. In this reported study, we aimed to evaluate the impact of translational and rotational errors on the robustness of linac-based, single-isocenter, coplanar, and non-coplanar volumetric modulated arc therapy treatment plans for multiple brain metastases. METHODS: Fifteen patients were retrospectively selected for this study with a combined total of 49 gross tumor volumes (GTVs). Single-isocenter coplanar and non-coplanar plans were generated first with a prescribed dose of 40 Gy in 5 fractions or 42 Gy in 7 fractions to cover 95% of planning target volume (PTV). Next, four setup errors (+1  and +2 mm translation, and +1° and +2° rotation) were applied individually to generate modified plans. Different plan quality evaluation metrics were compared between coplanar and non-coplanar plans. 3D gamma analysis (3%/2 mm) was performed to compare the modified plans (+2 mm and +2° only) and the original plans. Paired t-test was conducted for statistical analysis. RESULTS: After applying setup errors, variations of all plan evaluation metrics were similar (p > 0.05). The worst case for V100% to GTV was 92.07% ± 6.13% in the case of +2 mm translational error. 3D gamma pass rates were > 90% for both coplanar (+2 mm and +2°) and the +2 mm non-coplanar groups but was 87.40% ± 6.89% for the +2° non-coplanar group. CONCLUSION: Translational errors have a greater impact on PTV and GTV dose coverage for both planning methods. Rotational errors have a greater negative impact on gamma pass rates of non-coplanar plans. Plan evaluation metrics after applying setup errors showed that both coplanar and non-coplanar plans were robust and clinically acceptable.

Triglyceride-glucose index, renal function and cardiovascular disease: a national cohort study.

BACKGROUND: The triglyceride-glucose (TyG) index is a predictor of cardiovascular diseases; however, to what extent the TyG index is associated with cardiovascular diseases through renal function is unclear. This study aimed to evaluate the complex association of the TyG index and renal function with cardiovascular diseases using a cohort design. METHODS: This study included participants from the China Health and Retirement Longitudinal Study (CHARLS) free of cardiovascular diseases at baseline. We performed adjusted regression analyses and mediation analyses using Cox models. The TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Renal function was defined by the estimated glomerular filtration rate (eGFR). RESULTS: A total of 6 496 participants were included in this study. The mean age of the participants was 59.6 ± 9.5 years, and 2996 (46.1%) were females. During a maximum follow-up of 7.0 years, 1 996 (30.7%) people developed cardiovascular diseases, including 1 541 (23.7%) cases of heart diseases and 651 (10.0%) cases of stroke. Both the TyG index and eGFR level were significantly associated with cardiovascular diseases. Compared with people with a lower TyG index (median level) and eGFR ≥ 60 ml/minute/1.73 m2, those with a higher TyG index and decreased eGFR had the highest risk of cardiovascular diseases (HR, 1.870; 95% CI 1.131-3.069). Decreased eGFR significantly mediated 29.6% of the associations between the TyG index and cardiovascular diseases. CONCLUSIONS: The combination of a higher TyG index and lower eGFR level was associated with the highest risk of cardiovascular diseases. Renal function could mediate the association between the TyG index and cardiovascular risk.

Deep learning-based classification and spatial prognosis risk score on whole-slide images of lung adenocarcinoma.

AIMS: Classification of histological patterns in lung adenocarcinoma (LUAD) is critical for clinical decision-making, especially in the early stage. However, the inter- and intraobserver subjectivity of pathologists make the quantification of histological patterns varied and inconsistent. Moreover, the spatial information of histological patterns is not evident to the naked eye of pathologists. METHODS AND RESULTS: We establish the LUAD-subtype deep learning model (LSDLM) with optimal ResNet34 followed by a four-layer Neural Network classifier, based on 40 000 well-annotated path-level tiles. The LSDLM shows robust performance for the identification of histopathological subtypes on the whole-slide level, with an area under the curve (AUC) value of 0.93, 0.96 and 0.85 across one internal and two external validation data sets. The LSDLM is capable of accurately distinguishing different LUAD subtypes through confusion matrices, albeit with a bias for high-risk subtypes. It possesses mixed histology pattern recognition on a par with senior pathologists. Combining the LSDLM-based risk score with the spatial K score (K-RS) shows great capacity for stratifying patients. Furthermore, we found the corresponding gene-level signature (AI-SRSS) to be an independent risk factor correlated with prognosis. CONCLUSIONS: Leveraging state-of-the-art deep learning models, the LSDLM shows capacity to assist pathologists in classifying histological patterns and prognosis stratification of LUAD patients.

Novel Mechanisms of Perioperative Neurocognitive Disorders: Ferroptosis and Pyroptosis.

Perioperative neurocognitive disorders (PNDs) are some of the most common postoperative complications among the elderly and susceptible individuals, which significantly worsens the clinical outcome of patients. However, the prevention and treatment strategies of PNDs are difficult to determine and implement since the pathogenesis of PNDs is not well understood. The development of living organisms is associated with active and organized cell death, which is essential for maintaining the homeostasis of life. Ferroptosis is a programmed cell death (different from apoptosis and necrosis) mainly caused by an imbalance in the generation and degradation of intracellular lipid peroxides due to iron overload. Pyroptosis is an inflammatory cell death characterized by the creation of membrane holes mediated by the gasdermin (GSDM) family, followed by cell lysis and the release of pro-inflammatory cytokines. Ferroptosis and pyroptosis are involved in the pathogenesis of various central nervous system (CNS) diseases. Furthermore, ferroptosis and pyroptosis are closely associated with the occurrence and development of PNDs. This review summarizes the main regulatory mechanisms of ferroptosis and pyroptosis and the latest related to PNDs. Based on the available evidence, potential intervention strategies that can alleviate PNDs by inhibiting ferroptosis and pyroptosis have also been provided.

Longitudinal association between triglyceride glucose index and depression progression in middle-aged and elder adults: A national retrospective cohort study.

BACKGROUND AND AIMS: Psychological symptoms are prevalent among individuals with non-communicable diseases, while the longitudinal association between triglyceride glucose (TyG) index, an indicator of metabolic health, and depression progression remains unclear yet. This study aims to investigate the association of baseline TyG index and depression progression in middle-aged and elder adults. METHODS AND RESULTS: This retrospective cohort study enrolled 8287 participants aged 45 years or above from national China Health and Retirement Longitudinal Study in visit 1 (2011-2012), which were biennially followed for depression score until visit 4 (2017-2018). Multivariate-adjusted regression models were used to evaluate the association of baseline TyG index with the individual level change rate and slope of depression score. The mean age (±SD) of participants was 58.25 ± 9.10 years, and 3806 (45.9%) were men. There was no significant difference of depression score at baseline across TyG quartile groups (P = 0.228). Participants in the highest quartile of TyG index had a 0.124 (95% CI: 0.018-0.230) higher change rate of depression score, and a 0.127 (95% CI: 0.019-0.235) higher change slope, compared to those in the lowest. The observed associations were consistent in multiple sensitivity analyses, and stable in men, the elder, and overweight people. CONCLUSION: TyG index is positively associated with depression progression especially in men, the elder and overweight people, which provides new insights for the primary prevention of depression disorder.

Serelaxin Alleviates Fibrosis in Thyroid-Associated Ophthalmopathy via the Notch Pathway.

Fibrosis is the late stage of thyroid-associated ophthalmopathy (TAO), resulting in serious complications. Effective therapeutic drugs are still lacking. We aimed to explore the mechanism of TAO fibrosis and to find a targeted drug. High-throughput RNA sequencing was performed on orbital connective tissues from twelve patients with TAO and six healthy controls. Protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and we identified the hub gene by Cytoscape software. Additionally, the RNA sequencing results were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatic prediction identified the functions of differentially expressed genes (DEGs). Further orbital connective tissue and serum samples of the TAO and control groups were collected for subsequent experiments. Histologic staining, Western blotting (WB), qRT-PCR, enzyme-linked immunosorbent assays (ELISAs), gene overexpression through lentiviral infection or silencing gene by short interfering RNA (siRNA) were performed. We found that the relaxin signaling pathway is an important regulatory pathway in TAO fibrosis pathogenesis. Serelaxin exerts antifibrotic and anti-inflammatory effects in TAO. Furthermore, the downstream Notch pathway was activated by serelaxin and was essential to the antifibrotic effect of serelaxin in TAO. The antifibrotic effect of serelaxin is dependent on RXFP1.

Paris saponin VII, a Hippo pathway activator, induces autophagy and exhibits therapeutic potential against human breast cancer cells.

Dysregulation of the Hippo signaling pathway seen in many types of cancer is usually associated with a poor prognosis. Paris saponin VII (PSVII) is a steroid saponin isolated from traditional Chinese herbs with therapeutic action against various human cancers. In this study we investigated the effects of PSVII on human breast cancer (BC) cells and its anticancer mechanisms. We showed that PSVII concentration-dependently inhibited the proliferation of MDA-MB-231, MDA-MB-436 and MCF-7 BC cell lines with IC50 values of 3.16, 3.45, and 2.86 µM, respectively, and suppressed their colony formation. PSVII (1.2-1.8 µM) induced caspase-dependent apoptosis in the BC cell lines. PSVII treatment also induced autophagy and promoted autophagic flux in the BC cell lines. PSVII treatment decreased the expression and nuclear translocation of Yes-associated protein (YAP), a downstream transcriptional effector in the Hippo signaling pathway; overexpression of YAP markedly attenuated PSVII-induced autophagy. PSVII-induced, YAP-mediated autophagy was associated with increased active form of LATS1, an upstream effector of YAP. The activation of LATS1 was involved the participation of multiple proteins (including MST2, MOB1, and LATS1 itself) in an MST2-dependent sequential activation cascade. We further revealed that PSVII promoted the binding of LATS1 with MST2 and MOB1, and activated LATS1 in the BC cell lines. Molecular docking showed that PSVII directly bound to the MST2-MOB1-LATS1 ternary complex. Microscale thermophoresis analysis and drug affinity responsive targeting stability assay confirmed the high affinity between PSVII and the MST2-MOB1-LATS1 ternary complex. In mice bearing MDA-MB-231 cell xenograft, administration of PSVII (1.5 mg/kg, ip, 4 times/week, for 4 weeks) significantly suppressed the tumor growth with increased pLATS1, LC3-II and Beclin 1 levels and decreased YAP, p62 and Ki67 levels in the tumor tissue. Overall, this study demonstrates that PSVII is a novel and direct Hippo activator that has great potential in the treatment of BC.

Retracted: Cucurbitacin B Inhibits the Hippo-YAP Signaling Pathway and Exerts Anticancer Activity in Colorectal Cancer Cells.

This publication has been retracted by the Editor due to concerns regarding the originality of the figure images. Reference: Yanting Chai, Ke Xiang, Yezi Wu, Te Zhang, Ying Liu, Xuewen Liu, Weiguo Zhen, Yuan Si. Cucurbitacin B Inhibits the Hippo-YAP Signaling Pathway and Exerts Anticancer Activity in Colorectal Cancer Cells. Med Sci Monit, 2018; 24: LBR9251-9258. DOI: 10.12659/MSM.911594.

Metformin Attenuates Inflammation and Fibrosis in Thyroid-Associated Ophthalmopathy.

The pathogenesis of thyroid-associated ophthalmopathy (TAO) is still unclear, and therapeutic drugs have great limitations. As metformin has multiple therapeutic effects in many autoimmune diseases, we explored the effects of metformin on TAO in an in vitro fibroblast model. We used orbital connective tissues and fibroblasts that were obtained from TAO patients and normal controls. The activity of adenosine monophosphate-activated protein kinase (AMPK) and the levels of inflammatory or fibrotic factors were examined by immunofluorescence (IF) and immunohistochemistry (IHC). Quantitative real-time polymerase chain reaction (qPCR), cytokine quantification by enzyme-linked immunosorbent sssay (ELISA), IF, and western blotting (WB) were used to measure the expression of factors related to inflammation, fibrosis, and autophagy. To determine the anti-inflammatory and antifibrotic mechanisms of metformin, we pretreated cells with metformin, 5-aminoimidazole-4-carboxamide 1-ß-D-ribofuranoside (AICAR, an AMPK activator) or compound C (CC, an AMPK inhibitor) for 24 h and used WB to verify the changes in protein levels in the AMPK/mammalian target of rapamycin (mTOR) pathway. We determined that the low activity of AMPK in the periorbital tissue of TAO patients may be closely related to the occurrence and development of inflammation and fibrosis, and metformin exerts multiple effects by activating AMPK in TAO. Furthermore, we suggest that AMPK may be a potential target of TAO therapy.

Disulfiram Exerts Antifibrotic and Anti-Inflammatory Therapeutic Effects on Perimysial Orbital Fibroblasts in Graves' Orbitopathy.

Fibrosis of extraocular muscles (EOMs) is a marker of end-stage in Graves' orbitopathy (GO). To determine the antifibrotic and anti-inflammatory therapeutic effects and the underlying molecular mechanisms of disulfiram (DSF) on perimysial orbital fibroblasts (pOFs) in a GO model in vitro, primary cultures of pOFs from eight patients with GO and six subjects without GO (NG) were established. CCK-8 and EdU assays, IF, qPCR, WB, three-dimensional collagen gel contraction assays, cell scratch experiments, and ELISAs were performed. After TGF-ß1 stimulation of pOFs, the proliferation rate of the GO group but not the NG group increased significantly. DSF dose-dependently inhibited the proliferation, contraction, and migration of pOFs in the GO group. Additionally, DSF dose-dependently inhibited fibrosis and extracellular matrix production markers (FN1, COL1A1, α-SMA, CTGF) at the mRNA and protein levels. Furthermore, DSF mediates antifibrotic effects on GO pOFs partially through the ERK-Snail signaling pathway. In addition, DSF attenuated HA production and suppressed inflammatory chemokine molecule expression induced by TGF-ß1 in GO pOFs. In this in vitro study, we demonstrate the inhibitory effect of DSF on pOFs fibrosis in GO, HA production, and inflammation. DSF may be a potential drug candidate for preventing and treating tissue fibrosis in GO.

[Mechanism of polyphyllin â targeting EGFR to affect proliferation and apoptosis of human breast cancer cells].

This study aims to investigate the molecular mechanism of polyphyllin Ⅰ(PPⅠ) inhibiting proliferation of human breast cancer cells. Human breast cancer BT474 and MDA-MB-436 cells were treated with different concentrations of PPⅠ, and then the effect of PPⅠ on cell proliferation was detected by MTT assay, trypan blue dye exclusion assay, real-time cell analysis, and clone forming assay, respectively. The apoptosis was detected by Annexin V-FITC/PI staining and then analyzed by flow cytometry. The change of mitochondrial membrane potential was detected by flow cytometry after fluorescent probe JC-1 staining. Western blot was used to detect protein expression and phosphorylation. Molecular docking was performed to detect the binding between PPⅠ and EGFR. The affinity between PPⅠ and EGFR was determined by drug affinity responsive target stability assay. The results indicated that PPⅠ inhibited the proliferation and colony formation of BT474 and MDA-MB-436 cells in a time-and concentration-dependent manner. The PPⅠ treatment group showed significantly increased apoptosis rate and significantly decreased mitochondrial membrane potential. PPⅠ down-regulated the expression of pro-caspase-3 protein, promoted the cleavage of PARP, and significantly reduced the phosphorylation levels of EGFR, Akt, and ERK. Molecular docking showed that PPⅠ bound to the extracellular domain of EGFR and formed hydrogen bond with Gln366 residue. Drug affinity responsive target stability assay confirmed that PPⅠ significantly prevented pronase from hydrolyzing EGFR, indicating that PPⅠ and EGFR have a direct binding effect. In conclusion, PPⅠ inhibited the proliferation and induced apoptosis of breast cancer cells by targeting EGFR to block its downstream signaling pathway. This study lays a foundation for the further development of PPⅠ-targeted drugs against breast cancer.

A novel gene expression signature-based on B-cell proportion to predict prognosis of patients with lung adenocarcinoma.

BACKGROUND: This study aimed to develop a reliable immune signature based on B-cell proportion to predict the prognosis and benefit of immunotherapy in LUAD. METHODS: The proportion of immune cells in the TCGA-LUAD dataset was estimated using MCP-counter. The Least Absolute Shrinkage and Selector Operation was used to identify a prognostic signature and validated in an independent cohort. We used quantitative reverse transcription-polymerase chain reaction (qRT-PCR) data and formalin-fixed paraffin-embedded (FFPE) specimens immunohistochemistry to illustrate the correlation between prognostic signature and leukocyte migration. RESULTS: We found that the relative abundance of B lineage positively correlated with overall survival. Then, we identified a 13-gene risk-score prognostic signature based on B lineage abundance in the testing cohort and validated it in a cohort from the GEO dataset. This model remained strongly predictive of prognoses across clinical subgroups. Further analysis revealed that patients with a low-risk score were characterized by B-cell activation and leukocyte migration, which was also confirmed in FFPE specimens by qRT-PCR and immunohistochemistry. Finally, this immune signature was an independent prognostic factor in the composite nomogram of clinical characteristics. CONCLUSIONS: In conclusion, the 13-gene immune signature based on B-cell proportion may serve as a powerful prognostic tool in LUAD.

Synthesis and antitumor potential of new arylidene ursolic acid derivatives via caspase-8 activation.

Continuing our studies on NO-donating ursolic acid-benzylidene derivatives as potential antitumor agents, we designed and synthesized a series of new arylidene derivatives containing NO-donating ursolic acid and aromatic heterocyclic units. Compounds 5c and 6c showed a significant broad-spectrum antitumor activity. Compound 5c exhibited nearly three- to nine-fold higher cytotoxicity as compared with the parent drug in A549, MCF-7, HepG-2, HT-29, and HeLa cells, and it was also found to be the most potent apoptosis inducer of MCF-7 cells. More importantly, compound 5c arrested the MCF-7 cell cycle in the G1 phase, which was associated with caspase activation and a decrease of the Bcl-2/Bax ratio. Meanwhile, compound 5c caused changes in morphological features, dissipation of the mitochondrial membrane potential, and accumulation of reactive oxygen species. A docking study revealed that the nitroxyethyl moiety of compound 5c may form hydrogen bonds with caspase-8 amino acid residues (SER256 and HIS255). Together, these data suggest that NO-donating ursolic acid-arylidene derivatives are potent apoptosis inducers in tumor cells.

Differential flora in the microenvironment of lung tumor and paired adjacent normal tissues.

Recent evidence demonstrates the existence of diversified microbiota in the lung. However, the effect of lung carcinogenesis on the flora in lung microenvironment has yet not been well investigated. In this study, we surveyed the microbial composition and diversity in lung tumor and paired adjacent normal tissues obtained from 55 lung cancer patients to test whether any specific tumor-associated microbial features in lung microenvironment can be identified. Compared with non-malignant adjacent tissues, the tumor samples showed significantly lower community richness (α diversity), but no significant difference in overall microbiome dissimilarity (ß diversity). Strong intrasubject correlations were observed between tumor sample and its paired non-malignant adjacent tissues. In addition, correlation network analysis found more significant taxa-taxa correlations (adjusted q-value < 0.05) in tumor microenvironment than non-malignant adjacent tissues. At taxa level, we found Propionibacterium genus were significantly reduced in tumor tissues compared with non-malignant adjacent tissues. In summary, the microbiota in tumor tissues showed the lower richness, higher taxa-taxa interaction, and reduction of potential pro-inflammatory microbial genera compared with non-malignant tissues, suggesting the potential link between the tumor microbiota and the altered tumor microenvironment for the further investigation.

Polyphyllin I activates AMPK to suppress the growth of non-small-cell lung cancer via induction of autophagy.

Polyphyllin I (PPI), a bioactive constituent extracted from the rhizomes of Paris polyphylla, is cytotoxic to several cancer types. This study was designed to explore whether PPI prevents non-small-cell lung cancer (NSCLC) growth and to investigate the molecular mechanism. AMP-activated protein kinase (AMPK) has been implicated in the activation of autophagy in distinct tissues. In cultured human NSCLC cell lines, PPI induces autophagy by activating AMPK and then inhibiting mTOR signaling in a concentration-dependent manner. Furthermore, the activation of autophagy induced by PPI was reversed by the AMPK inhibitor compound C. Computational docking showed that PPI directly interacted with the allosteric drug and metabolite site of AMPK to stabilize its activation. Microscale thermophoresis and Drug Affinity Responsive Targeting Stability (DARTS) assay further confirmed the high affinity between PPI and AMPK. In vivo studies indicated that PPI suppressed the growth of NSCLC and increased the levels of LC3-II and phosphorylated AMPK in tumors isolated from a xenograft model of NSCLC in mice. Moreover, PPI exhibited favorable pharmacokinetics in rats. In summary, PPI conclusively acts as a direct AMPK activator to induce cell autophagy which inhibits the growth of NSCLC cells. In the future, PPI therapy should be applied to treat patients with NSCLC.

Cucurbitacin B inhibits gastric cancer progression by suppressing STAT3 activity.

Signal transducer and activator of transcription 3 (STAT3) is expressed aberrantly in multiple tumors, including gastric cancer (GC). STAT3 overexpression and excessive activation have been confirmed to play vital roles in tumorigenesis. Cucurbitacin B (CuB) is a natural product with potent anti-cancer activities in solid tumors. Here, we systematically studied the underlying molecular mechanisms of CuB inhibition of GC both in vitro and in vivo. In GC cell lines, nanomolar concentrations of CuB decreased the phosphorylation of TYR-705 in STAT3 and suppressed STAT3 target gene expression, including c-Myc and Bcl-xL. Computational docking analysis showed that CuB interacts with the DNA-binding domain of STAT3 at several hydrophobic residues. In addition, pull-down experiments showed that CuB is a direct inhibitor of STAT3. CuB in combination with the conventional chemotherapy drug cisplatin exerted enhanced cytotoxicity in GC cells, possibly due to the potentiated inhibition of STAT3 activation. Moreover, a xenograft mouse model confirmed the therapeutic effect of CuB in vivo. These characteristics render CuB a promising candidate drug for further development in the design of new effective STAT3 inhibitors for treating GC.

Cucurbitacin B induces inhibitory effects via the CIP2A/PP2A/C-KIT signaling axis in t(8;21) acute myeloid leukemia.

Acute myeloid leukemia (AML) is the most common subtype of hematological malignancy in humans, and its incidence increases with age. The treatment of AML still faces challenges. Therefore, there is an urgent need to develop more effective targeted therapies. The receptor tyrosine kinase C-KIT confers critical proliferative signals to AML. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an endogenous inhibitor of protein phosphatase 2A (PP2A), which promotes the growth and transformation of various solid tumors. These actions make CIP2A a promising target for tumor treatment. Here, we reported the effects and underlying mechanisms of a natural compound, cucurbitacin B (CuB), on AML. We reported that CuB suppressed growth and induced apoptosis in AML cells. The inhibition of growth and activation of apoptosis were mediated through CuB-induced downregulation of the CIP2A/PP2A/C-KIT signal pathway. Furthermore, CuB inactivated the JAK2 and STAT3 molecules downstream of C-KIT via the downregulation of CIP2A. These results advance our understanding of CuB-induced growth inhibition and apoptosis and support further investigation of CuB as a CIP2A inhibitor for AML therapies.