Association of systemic immune-inflammation index with insulin resistance and prediabetes: a cross-sectional study.

Background and Objective: Previous research suggested a relationship between the Systemic Immune-Inflammation Index (SII) and multiple adverse health conditions. However, the role of SII in prediabetes and insulin resistance (IR) remains poorly understood. Therefore, this study aims to explore the potential relationship between SII and prediabetes and IR, providing data support for effective diabetes prevention by reducing systemic inflammation. Methods: Linear regression models were used to assess the correlation between continuous SII and risk markers for type 2 diabetes (T2D). Subsequently, multivariate logistic regression models and subgroup analyses were employed to evaluate the association between SII tertiles and prediabetes and IR, controlling for various confounding factors. Finally, restricted cubic spline graphs were used to analyze the nonlinear relationship between SII and IR and prediabetes. Results: After controlling for multiple potential confounders, SII was positively correlated with fasting blood glucose (FBG) (ß: 0.100; 95% CI: 0.040 to 0.160), fasting serum insulin (FSI) (ß: 1.042; 95% CI: 0.200 to 1.885), and homeostasis model assessment of insulin resistance (HOMA-IR) (ß: 0.273; 95% CI: 0.022 to 0.523). Compared to participants with lower SII, those in the highest tertile had increased odds of prediabetes (OR: 1.17; 95% CI: 1.02-1.34; p for trend < 0.05) and IR (OR: 1.35; 95% CI: 1.18 to 1.51; p for trend<0.001). Conclusions: Our study results demonstrate an elevated association between SII levels and both IR and prediabetes, indicating SII as a straightforward and cost-effective method identifying individuals with IR and prediabetes.

Minnelide exhibits antileukemic activity by targeting the Ars2/miR-190a-3p axis.

BACKGROUND: The identification of a novel and effective strategy for the clinical treatment of acute leukemia (AL) is a long-term goal. Minnelide, a water-soluble prodrug of triptolide, has recently been evaluated in phase I and II clinical trials in patients with multiple cancers and has shown promise as an antileukemic agent. However, the molecular mechanism underlying minnelide's antileukemic activity remains unclear. PURPOSE: To explore the molecular mechanisms by which minnelide exhibits antileukemic activity. METHODS: AL cells, primary human leukemia cells, and a xenograft mouse model were treated with triptolide and minnelide. The molecular mechanism was elucidated using western blotting, immunoprecipitation, flow cytometry, GSEA and liquid chromatography-mass spectrometry analysis. RESULTS: Minnelide was highly effective in inhibiting leukemogenesis and improving survival in two complementary AL mouse models. Triptolide, an active form of minnelide, causes cell cycle arrest in G1 phase and induces apoptosis in both human AL cell lines and primary AL cells. Mechanistically, we identified Ars2 as a new chemotherapeutic target of minnelide for AL treatment. We found that triptolide directly targeted Ars2, resulting in the downregulation of miR-190a-3p, which led to the disturbance of PTEN/Akt signaling and culminated in G1 cell cycle arrest and apoptosis. CONCLUSIONS: Our findings demonstrate that targeting Ars2/miR-190a-3p signaling using minnelide could represent a novel chemotherapeutic strategy for AL treatment and support the evaluation of minnelide for the treatment of AL in clinical trials.

Arsenic resistance protein 2 and microRNA biogenesis: Biological implications in cancer development.

Arsenic resistance protein 2 (Ars2) is a nuclear protein that plays a critical role in the regulation of microRNA (miRNA) biogenesis. Ars2 is required for cell proliferation and for the early stages of mammalian development through a possible effect on miRNA processing. Increasing evidence reveal that Ars2 is highly expressed in proliferating cancer cells, suggesting that Ars2 may be a potential therapeutic target for cancer. Therefore, development of the novel Ars2 inhibitors could represent the novel therapeutic strategies for treatment of cancer. In this review, we briefly discuss the mechanisms by which Ars2 regulates miRNA biogenesis and its impact on cell proliferation and cancer development. Particularly, we mainly discuss the role of Ars2 in the regulation of cancer development and highlight pharmacological targeting of Ars2 as a promising cancer therapeutic strategy.

Targeting PI4KA sensitizes refractory leukemia to chemotherapy by modulating the ERK/AMPK/OXPHOS axis.

Background: The emergence of chemoresistance in leukemia markedly impedes chemotherapeutic efficacy and dictates poor prognosis. Recent evidence has revealed that phosphatidylinositol 4 kinase-IIIα (PI4KA) plays a critical role in tumorigenesis. However, the molecular mechanisms of PI4KA-regulated chemoresistance and leukemogenesis remain largely unknown. Methods: Liquid chromatography-mass spectrometry (LC-MS), patient samples and leukemia xenograft mouse models were used to investigate whether PI4KA was an effective target to overcome chemoresistance in leukemia. Enzyme-linked immunosorbent assay (ELISA) and molecular mechanics/generalized born surface area (MM/GBSA) method were employed to identify cepharanthine (CEP) as a novel PI4KA inhibitor. Results: High expression of PI4KA was observed in drug-resistant leukemia cells or in relapsed leukemia patients, which was correlated with poor overall survival. Depletion of PI4KA sensitized drug-resistant leukemia cells to chemotherapeutic drugs in vitro and in vivo by regulating ERK/AMPK/OXPHOS axis. We also identified cepharanthine (CEP) as a novel PI4KA inhibitor, which could undermine the stability of the PI4KA/TTC7/FAM126 complex, enhancing the sensitivity of drug-resistant leukemia cells to chemotherapeutic drugs in vitro and in vivo. Conclusions: Our study underscored the potential of therapeutic targeting of PI4KA to overcome chemoresistance in leukemia. A combination of the PI4KA inhibitor with classic chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of refractory leukemia.

Xanthones and benzophenones isolated from the endophytic fungus Penicillium sp. ct-28 of Corydlis tomentella and their cytotoxic activity.

One new xanthone, griseophenexanthone A (1), one new benzophenone, digriseophene A (2), and 14 previously reported compounds were isolated from the culture of Penicillium sp. ct-28, an endophytic fungus of Corydlis tomentella. The structures of the isolated compounds were identified by an extensive analysis of HRESIMS, 1D and 2D NMR. MTT assay showed that six xanthones (1 and 3-7) significantly inhibited cell proliferation in four cancer cell lines, with IC50 values ranging from 18.12 ± 2.42 to 85.55 ± 7.66 µM. Our results showed that slight structural changes led to obvious activity differences among these compounds. We also investigated the effects of the six xanthones on cell cycle and apoptosis in human hepatoma HepG2 cells. Compound 7 caused cell cycle arrest at G1 phase, compounds 5 and 6 caused cell cycle arrest at S phase, whereas compounds 1, 3 and 4 had no effects on cell cycle distribution. All six xanthones induced apoptosis in dose-dependent manners in HepG2 cells accompanied by degradation of PARP and activation of caspase 3. The structure-activity relationship analysis revealed that the effects of these xanthones on cell cycle and apoptosis in HepG2 cells were closely related to the substituent groups on their skeleton. Our studies provide novel insights for the structural optimization of xanthones in the development of new anticancer drugs.

Cepharanthine sensitizes human triple negative breast cancer cells to chemotherapeutic agent epirubicin via inducing cofilin oxidation-mediated mitochondrial fission and apoptosis.

Inhibition of autophagy has been accepted as a promising therapeutic strategy in cancer, but its clinical application is hindered by lack of effective and specific autophagy inhibitors. We previously identified cepharanthine (CEP) as a novel autophagy inhibitor, which inhibited autophagy/mitophagy through blockage of autophagosome-lysosome fusion in human breast cancer cells. In this study we investigated whether and how inhibition of autophagy/mitophagy by cepharanthine affected the efficacy of chemotherapeutic agent epirubicin in triple negative breast cancer (TNBC) cells in vitro and in vivo. In human breast cancer MDA-MB-231 and BT549 cells, application of CEP (2 µM) greatly enhanced cepharanthine-induced inhibition on cell viability and colony formation. CEP interacted with epirubicin synergistically to induce apoptosis in TNBC cells via the mitochondrial pathway. We demonstrated that co-administration of CEP and epirubicin induced mitochondrial fission in MDA-MB-231 cells, and the production of mitochondrial superoxide was correlated with mitochondrial fission and apoptosis induced by the combination. Moreover, we revealed that co-administration of CEP and epirubicin markedly increased the generation of mitochondrial superoxide, resulting in oxidation of the actin-remodeling protein cofilin, which promoted formation of an intramolecular disulfide bridge between Cys39 and Cys80 as well as Ser3 dephosphorylation, leading to mitochondria translocation of cofilin, thus causing mitochondrial fission and apoptosis. Finally, in mice bearing MDA-MB-231 cell xenografts, co-administration of CEP (12 mg/kg, ip, once every other day for 36 days) greatly enhanced the therapeutic efficacy of epirubicin (2 mg/kg) as compared with administration of either drug alone. Taken together, our results implicate that a combination of cepharanthine with chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of breast cancer.

Decoding the Mechanism of Shen Qi Sha Bai Decoction in Treating Acute Myeloid Leukemia Based on Network Pharmacology and Molecular Docking.

Traditional Chinese Medicine (TCM) has been shown to be efficacious in treating leukemia for thousands of years. It has been shown that Shen Qi Sha Bai Decoction (SQSBD) has been extensively used in the treatment of acute myeloid leukemia (AML). However, the mechanism of SQSBD in treating AML remains unclear. In this study, we employed network pharmacology to analyze the potential active components and elucidate molecular mechanism of SQSBD in treating AML. A total of 268 active components were identified from SQSBD, among which 9 key components (Quercetin, luteolin, kaempferol, licochalcone A, formononetin, wogonin, ß-sitosterol, oroxylin A, naringenin, and baicalein) were hit by the 6 hub targets (CDK1, MAPK1, JUN, PCNA, HSB1, STAT3) associated with leukemia. Molecular docking showed that two core active components, quercetin and licochalcone A, exhibited the highest component-like properties (DL), and could bind well to CDK1 and MAPK1 protein. The experimental validation of these two components showed that quercetin inhibited cell growth through CDK1 dephosphorylation-mediated cell cycle arrest at G2/M phase in human AML U937 and HL60 cells, and licochalcone A induced cell differentiation in these leukemia cells via activation of MAPK1 and upregulation of CD11b. All these results indicate that SQSBD is effective in the treatment of AML, and quercetin and licochalcone A are the major candidate compounds for AML treatment.

ROCK1 activation-mediated mitochondrial translocation of Drp1 and cofilin are required for arnidiol-induced mitochondrial fission and apoptosis.

BACKGROUND: Arnidiol is a pentacyclic triterpene diol that has multiple pharmacological activities. However, the apoptotic activities of arnidiol in human cancer cells have not yet been explored, nor has the mechanism by which arnidiol induces apoptosis been examined in depth. METHODS: MDA-MB-231 cells and xenografted mice were treated with arnidiol. Mitochondrial fission and apoptosis were determined by immunofluorescence, flow cytometry and related molecular biological techniques. The interaction and colocalization of cofilin and Drp1 was determined by immunoprecipitation and immunofluorescence assays. RESULTS: Arnidiol induces mitochondrial fission and apoptosis through mitochondrial translocation of Drp1 and cofilin. Importantly, the interaction of Drp1 and cofilin in mitochondria is involved in arnidiol-induced mitochondrial fission and apoptosis. Knockdown of either Drp1 or cofilin abrogated arnidiol-induced mitochondrial translocation, interaction of Drp1 and cofilin, mitochondrial fission and apoptosis. Only dephosphorylated Drp1 (Ser637) and cofilin (Ser3) were translocated to the mitochondria. Mutants of Drp1 S637A and cofilin S3A, which mimic the dephosphorylated forms, enhanced mitochondrial fission and apoptosis induced by arnidiol, whereas mutants of Drp1 S637D and cofilin S3E, which mimic the phosphorylated forms, suppressed mitochondrial fission and apoptosis induced by arnidiol. A mechanistic study revealed that ROCK1 activation plays an important role in the arnidiol-mediated Drp1 and cofilin dephosphorylation and mitochondrial translocation, mitochondrial fission, and apoptosis. CONCLUSIONS: Our data reveal a novel role of both Drp1 and cofilin in the regulation of mitochondrial fission and apoptosis and suggest that arnidiol could be developed as a potential agent for the treatment of human cancer.

Downregulation of MYO1C mediated by cepharanthine inhibits autophagosome-lysosome fusion through blockade of the F-actin network.

BACKGROUND: MYO1C, an actin-based motor protein, is involved in the late stages of autophagosome maturation and fusion with the lysosome. The molecular mechanism by which MYO1C regulates autophagosome-lysosome fusion remains largely unclear. METHODS: Western blotting was used to determine the expression of autophagy-related proteins. Transmission electron microscopy (TEM) was used to observe the ultrastructural changes. An immunoprecipitation assay was utilized to detect protein-protein interactions. Immunofluorescence analysis was used to detect autophagosome-lysosome fusion and colocalization of autophagy-related molecules. An overexpression plasmid or siRNA against MYO1C were sequentially introduced into human breast cancer MDA-MB-231 cells. RESULTS: We show here that cepharanthine (CEP), a novel autophagy inhibitor, inhibited autophagy/mitophagy through blockage of autophagosome-lysosome fusion in human breast cancer cells. Mechanistically, we found for the first time that MYO1C was downregulated by CEP treatment. Furthermore, the interaction/colocalization of MYO1C and F-actin with either LC3 or LAMP1 was inhibited by CEP treatment. Knockdown of MYO1C further decreased the interaction/colocalization of MYO1C and F-actin with either LC3 or LAMP1 inhibited by CEP treatment, leading to blockade of autophagosome-lysosome fusion. In contrast, overexpression of MYO1C significantly restored the interaction/colocalization of MYO1C and F-actin with either LC3 or LAMP1 inhibited by CEP treatment. CONCLUSION: These findings highlight a key role of MYO1C in the regulation of autophagosome-lysosome fusion through F-actin remodeling. Our findings also suggest that CEP could potentially be further developed as a novel autophagy/mitophagy inhibitor, and a combination of CEP with classic chemotherapeutic drugs could become a promising treatment for breast cancer.

ROS-mediated activation and mitochondrial translocation of CaMKII contributes to Drp1-dependent mitochondrial fission and apoptosis in triple-negative breast cancer cells by isorhamnetin and chloroquine.

BACKGROUND: Triple-negative breast cancer (TNBC) is often aggressive and associated with a poor prognosis. Due to the lack of available targeted therapies and to problems of resistance with conventional chemotherapeutic agents, finding new treatments for TNBC remains a challenge and a better therapeutic strategy is urgently required. METHODS: TNBC cells and xenograft mice were treated with a combination of chloroquine (CQ) and isorhamnetin (IH). Mitochondrial fission, apoptosis, and related signaling pathways were determined by flow cytometry, immunofluorescence, and related molecular biological techniques. RESULTS: The inhibition of autophagy/mitophagy by CQ selectively enhances IH-induced mitochondrial fission and apoptosis in TNBC cells but not in estrogen-dependent breast cancer cells. These events were accompanied by mitochondrial translocation of Bax and the release of cytochrome c. Mechanistically, these effects were associated with oxidative stress-mediated phosphorylation of CaMKII (Thr286) and Drp1 (S616), and subsequent mitochondrial translocation of CaMKII and Drp1. The interruption of the CaMKII pathway by genetic approaches (e.g. CaMKII mutant or siRNA) attenuated combination-mediated mitochondrial fission and apoptosis. The combination of CQ/IH was a marked inhibitor tumor growth, inducing apoptosis in the TNBC xenograft mouse model in association with the activation of CaMKII and Drp1 (S616). CONCLUSIONS: Our study highlights the critical role of ROS-mediating CaMKII/Drp1 signaling in the regulation of mitochondrial fission and apoptosis induced by combination of CQ/IH. These findings also suggest that IH could potentially be further developed as a novel chemotherapeutic agent. Furthermore, a combination of IH with classic autophagy/mitophagy inhibitor could represent a novel therapeutic strategy for the treatment of TNBC.

Nuclear accumulation of UBC9 contributes to SUMOylation of lamin A/C and nucleophagy in response to DNA damage.

BACKGROUND: Macroautophagy (hereafter referred to as autophagy) is an evolutionarily conserved intracellular mechanism for lysosomal degradation of damaged cellular components. The specific degradation of nuclear components by the autophagy pathway is called nucleophagy. Most studies have focused on autophagic turnover of cytoplasmic materials, and little is known about the role of autophagy in the degradation of nuclear components. METHODS: Human MDA-MB-231 and MCF-7 breast cancer cell lines were used as model systems in vitro. Induction of nucleophagy by nuclear DNA leakage was determined by western blot and immunofluorescence analyses. The interaction and colocalization of LC3 and lamin A/C was determined by immunoprecipitation and immunofluorescence. The role of the SUMO E2 ligase, UBC9, on the regulation of SUMOylation of lamin A/C and nucleophagy was determined by siRNA silencing of UBC9, and analyzed by immunoprecipitation and immunofluorescence. RESULTS: DNA damage induced nuclear accumulation of UBC9 ligase which resulted in SUMOylation of lamin A/C and that SUMOylation of this protein was required for the interaction between the autophagy protein LC3 and lamin A/C, which was required for nucleophagy. Knockdown of UBC9 prevented SUMOylation of lamin A/C and LC3-lamin A/C interaction. This attenuated nucleophagy which degraded nuclear components lamin A/C and leaked nuclear DNA mediated by DNA damage. CONCLUSIONS: Our findings suggest that nuclear DNA leakage activates nucleophagy through UBC9-mediated SUMOylation of lamin A/C, leading to degradation of nuclear components including lamin A/C and leaked nuclear DNA.

Depletion of Ars2 inhibits cell proliferation and leukemogenesis in acute myeloid leukemia by modulating the miR-6734-3p/p27 axis.

Ars2 is a component of the nuclear cap-binding complex (CBC) that contributes to microRNA biogenesis and is required for cellular proliferation. Little is known regarding the functional role of Ars2 in cell proliferation and leukemogenesis of acute myeloid leukemia. Here, we show that the elevated expression of Ars2 was observed in acute myeloid leukemia (AML) cell lines and bone marrow samples from AML patients and was correlated with poorer overall survival. Overexpression of Ars2 promoted cell proliferation and colony formation in AML cells, whereas depletion of Ars2 inhibited cell proliferation and colony formation. Mechanistic studies reveal that depletion of Ars2 suppressed the interaction of Ars2 with CBC and led to alterations in miRNA processing. Furthermore, Ars2 depletion reduced the levels of miR-6734-3p, resulting in upregulation of p27 and culminating in cell cycle arrest at the G1 phase. In vivo studies indicate that depletion of Ars2 significantly reduced leukemic cell burden and prolonged the survival time of the leukemia-bearing mice. These findings indicate that Ars2 may not only play a crucial role in the regulation of cell proliferation and leukemogenesis, but could also be identified as a critical therapeutic target for treatment of AML.

A novel autophagy inhibitor berbamine blocks SNARE-mediated autophagosome-lysosome fusion through upregulation of BNIP3.

Increasing evidences reveal that autophagy inhibitor could enhance the effect of chemotherapy to cancer. However, few autophagy inhibitors are currently approved for clinical application in humans. Berbamine (BBM) is a natural compound extracted from traditional Chinese medicine that is widely used for treatment of a variety of diseases without any obvious side effects. Here we found that BBM is a novel auophagy inhibitor, which potently induced the accumulation of autophagosomes by inhibiting autophagosome-lysosome fusion in human breast cancer cells. Mechanistically, we found that BBM blocked autophagosome-lysosome fusion by inhibiting the interaction of SNAP29 and VAMP8. Furthermore, BBM induced upregulation of BNIP3 and the interaction between SNAP29 and BNIP3. BNIP3 depletion or SNAP29 overexpression abrogated BBM-mediated blockade of autophagosome-lysosome fusion through the interaction between SNAP29 and VAMP8, whereas BNIP3 overexpression blocked autophagosome-lysosome fusion through inhibition of the interaction between SNAP29 and VAMP8. These findings suggest that upregulation of BNIP3 and interaction between BNIP3 and SNAP29 could be involved in BBM-mediated blockade of autophagosome-lysosome fusion through inhibition of the interaction between SNAP29 and VAMP8. Our findings identify the critical role of BNIP3 in blockade of autophagosome-lysosome fusion mediated by BBM, and suggest that BBM could potentially be further developed as a novel autophagy inhibitor, which could enhance the effect of chemotherapy to cancer.