The cyclohexene derivative MC-3129 exhibits antileukemic activity via RhoA/ROCK1/PTEN/PI3K/Akt pathway-mediated mitochondrial translocation of cofilin

CFL1 is Implicated in Chronic Myeloid Leukemia Response during Imatinib Therapy

Cofilin (CFL1) is one critical member of the actin deploy family (ADF). Overexpression of CFL1 is associated with aggressive features and poor prognosis in malignancies. We evaluated the expression of CFL1 in patients with chronic myeloid leukemia in the chronic phase (CML-CP), acute myelocytic leukemia (AML) and healthy controls. The role of CFL1 in imatinib therapy was also investigated using cell line. We found that the expression of CFL1 was lower in CML patients than that in healthy controls, and was significantly upregulated after imatinib therapy (p<0.05). CML patients with lower CFL1 achieved higher Major molecular response (MMR) rate after 6 months of imatinib therapy (p<0.05). Cofilin, P-cofilin and F-actin, especially branched F-actin were all upregulated after imatinib therapy. The lower CFL1 expression before treatment may predicts a better response to imatinib. Imatinib affects F-actin remodeling in CML patients by regulating CFL1 expression and activity.

Inactivation of KDM5A suppresses growth and enhances chemosensitivity in liver cancer by modulating ROCK1/PTEN/AKT pathway

Liver cancer is a kind of malignant tumor with poor sensitivity to chemotherapy. It is urgent to investigate approaches to improve the outcome of chemotherapy. KDM5A has been reported to be an oncogene in various cancers and is associated with drug resistance. However, the functions of KDM5A in chemotherapeutic sensitivity of liver cancer not been well illustrated. In this study, we found that KDM5A was upregulated in liver cancer tissue and cell lines. KDM5A knockdown using a gene interference strategy suppressed the growth of liver cancer in vitro and in vivo. CPI-455, a pharmacological inactivation of KDM5A enhanced the cytotoxicity of cisplatin (CDDP) in liver cells. CPI-455 and CDDP cotreatment resulted in apoptosis and mitochondrial dysfunction. We also found that knockdown or inactivation of KDM5A resulted in the downregulation of ROCK1, an oncogene regulating the activation of the PTEN/AKT signaling pathway. In particular, overexpression of ROCK1 or SF1670, a pharmacological inhibitor of PTEN, alleviated the cytotoxicity of CPI-455 and CDDP cotreatment. In HCCLM3 xenografts, CPI-455 and CDDP cotreatment dramatically inhibited the growth of xenograft tumor compared to CPI-455 or CDDP treatment alone. In conclusion, this study suggested that targeting the inactivation of KDM5A is an efficient strategy to enhance the chemosensitivity of liver cancer cells to CDDP by modulating the ROCK1/PTEN/AKT signaling pathway.

Construction of a synthetic methodology-based library and its application in identifying a GIT/PIX protein-protein interaction inhibitor

In recent years, the flourishing of synthetic methodology studies has provided concise access to numerous molecules with new chemical space. These compounds form a large library with unique scaffolds, but their application in hit discovery is not systematically evaluated. In this work, we establish a synthetic methodology-based compound library (SMBL), integrated with compounds obtained from our synthetic researches, as well as their virtual derivatives in significantly larger scale. We screen the library and identify small-molecule inhibitors to interrupt the protein-protein interaction (PPI) of GIT1/β-Pix complex, an unrevealed target involved in gastric cancer metastasis. The inhibitor 14-5-18 with a spiro[bicyclo[2.2.1]heptane-2,3'-indolin]-2'-one scaffold, considerably retards gastric cancer metastasis in vitro and in vivo. Since the PPI targets are considered undruggable as they are hard to target, the successful application illustrates the structural specificity of SMBL, demonstrating its potential to be utilized as compound source for more challenging targets.

Downregulation of MCF2L Promoted the Ferroptosis of Hepatocellular Carcinoma Cells through PI3K/mTOR Pathway in a RhoA/Rac1 Dependent Manner

Methods and Results

The levels of MCF2L were detected by PCR and western blotting assay. The effect of MCF2L on ferroptosis was confirmed by MTT, colony formation assay, Brdu, in vivo animal experiment, and the content of Iron, GSH, ROS, and MDA. The underlying mechanisms were explored by PCR, western blotting, and affinity precipitation assay. Our findings demonstrated that MCF2L is remarkedly upregulated in HCC tissues, and sorafenib can induce the levels of MCF2L, suggesting that MCF2L might function in sorafenib resistance of HCC. Further analysis showed that downregulation of MCF2L enhances HCC cell death induced by sorafenib, and ferroptosis inhibitor can reverse this process. Subsequent experiments showed that downregulation of MCF2L elevates the content of Iron, ROS, and MDA, which are all indicators of ferroptosis. Finally, mechanism analysis showed that MCF2L regulates the PI3K/AKT pathway in a RhoA/Rac1 dependent manner.

Conclusions

Our study showed that targeting MCF2L may be a hopeful method to overcome sorafenib-resistance through inducing ferroptosis in HCC.

MiR-361-5p/abca1 and MiR-196-5p/arhgef12 Axis Involved in γ-Sitosterol Inducing Dual Anti-Proliferative Effects on Bronchial Epithelial Cells of Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD), a progressive and irreversible respiratory disease, becomes the third leading cause of death and results in enormous economic burden on healthcare costs and productivity loss worldwide by 2020. Thus, it is urgent to develop effective anti-COPD drugs.

Materials and Methods

In the present study, two published GEO profiles were used to re-analyze and ascertain the relationships between circulating miRNAs and bronchial epithelial cells (BECs) mRNAs in COPD. The microRNA levels of miR-361-5p and miR-196-5p in plasma of COPD patients and healthy volunteers were detected by qRT-PCR. Next, the effects of γ-sitosterol (GS) on the expression of miR-361-5p and miR-196-5p and cell proliferation were investigated in BEC and H292 cell lines. Finally, whether specific miRNA-mRNA pathways involved in the effect of GS on BECs was assayed using Western Blot, real-time PCR and immunofluorescence.

Results

miR-196-5p and miR-361-5p were, respectively, up- and down-regulated in COPD patients compared with healthy controls. Luciferase assays demonstrated that miR-361-5p and miR-196-5p were, respectively, targeting abca1 and arhgef12 3ʹUTR in BEAS-2B cells. GS significantly suppressed miR-196-5p and promoted miR-361-5p levels in BEAS-2B cells and inhibited BECs proliferation in vitro. GS promoted miR-361-5p expression, which inhibited BCAT1 mRNA and protein levels and weaken mTOR-pS6K pathway, resulted in anti-proliferation in BEAS-2B cells. In addition, RhoA was activated by ARHGEF12 due to the inhibitory effect of miR-196-5p on arhgef12-3ʹUTR which was partially abolished by GS suppressing miR-196-5p expression. Activated RhoA further activated ROCK1-PTEN pathway and finally inhibited mTOR pathway, resulting in induced BECs proliferation. The anti-proliferation effect of GS was not observed in H292 cells.

Conclusion

These findings indicate that miR-361-5p/abca1 and miR-196-5p/arhgef12 axis mediated GS inducing dual anti-proliferation effects on BECs.

Cyclovirobuxine D Induces Apoptosis and Mitochondrial Damage in Glioblastoma Cells Through ROS-Mediated Mitochondrial Translocation of Cofilin

Background

Cyclovirobuxine D (CVBD), a steroidal alkaloid, has multiple pharmacological activities, including anti-cancer activity. However, the anti-cancer effect of CVBD on glioblastoma (GBM) has seldom been investigated. This study explores the activity of CVBD in inducing apoptosis of GBM cells, and examines the related mechanism in depth.

Methods

GBM cell lines (T98G, U251) and normal human astrocytes (HA) were treated with CVBD. Cell viability was examined by CCK-8 assay, and cell proliferation was evaluated by cell colony formation counts. Apoptosis and mitochondrial superoxide were measured by flow cytometry. All protein expression levels were determined by Western blotting. JC-1 and CM-H₂DCFDA probes were used to evaluate the mitochondrial membrane potential (MMP) change and intracellular ROS generation, respectively. The cell ultrastructure was observed by transmission electron microscope (TEM). Colocalization of cofilin and mitochondria were determined by immunofluorescence assay.

Results

CVBD showed a greater anti-proliferation effect on the GBM cell lines, T98G and U251, than normal human astrocytes in dose- and time-dependent manners. CVBD induced apoptosis and mitochondrial damage in GBM cells. We found that CVBD led to mitochondrial translocation of cofilin. Knockdown of cofilin attenuated CVBD-induced apoptosis and mitochondrial damage. Additionally, the generation of ROS and mitochondrial superoxide was also induced by CVBD in a dose-dependent manner. N-acetyl-L-cysteine (NAC) and mitoquinone (MitoQ) pre-treatment reverted CVBD-induced apoptosis and mitochondrial damage. MitoQ pretreatment was able to block the mitochondrial translocation of cofilin caused by CVBD.

Conclusions

Our data revealed that CVBD induced apoptosis and mitochondrial damage in GBM cells. The underlying mechanism is related to mitochondrial translocation of cofilin caused by mitochondrial oxidant stress.

INNO-406 inhibits the growth of chronic myeloid leukemia and promotes its apoptosis via targeting PTEN

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm. INNO-406 is a novel tyrosine kinase inhibitor (TKI) that possess specific Lyn kinase inhibitory activity with no or limited activity against other sarcoma (Src) family member kinases. The present study aimed to confirm the anti-tumor effect of INNO-406 on CML cells, and elucidate the underlying molecular mechanism. CML cells were treated by INNO-406 at the concentration of 5, 25, 50, 100 μM at the indicated time. Cell proliferation was measured by MTT. Cell apoptosis were detected by Western blot and flow cytometry, respectively. As suggested by the findings, INNO-406 significantly inhibited the proliferation and induced apoptosis of CML cells. In addition, INNO-406 promoted the expression level of PTEN. Rescue experiment revealed that PTEN knockdown reversed the effect of INNO-406 which indicated the correlation between INNO-406 and PTEN. Further study determined that PTEN inhibited the phosphorylation of AKT and 4EBP1 and subsequently altered the expression of apoptotic proteins including bax, cytoplasmic cytochrome c (cyto-c), cleaved caspase3 and bcl-2. In vivo study further confirmed that INNO-406 inhibited the growth of CML cells by targeting PTEN. Based on the above findings, this work extended our understanding of INNO-406 in the therapy of CML and its molecular mechanism.

Lycorine Induces Mitochondria-Dependent Apoptosis in Hepatoblastoma HepG2 Cells Through ROCK1 Activation

Lycorine, a naturally occurring compound extracted from the Amaryllidaceae plant family, has been reported to exhibit antitumor activity in various cancer cell types. In the present study, we investigated the molecular mechanisms underlying lycorine-induced apoptosis in hepatoblastoma HepG2 cells. We found that lycorine induced mitochondria-dependent apoptosis in HepG2 cells accompanied by mitochondrial permeability transition pore (mPTP) opening, mitochondrial membrane potential (MMP) loss, adenosine triphosphate (ATP) depletion, Ca²⁺ and cytochrome c (Cyto C) release, as well as caspase activation. Furthermore, we found Rho associated coiled-coil containing protein kinase 1 (ROCK1) cleavage/activation played a critical role in lycorine-induced mitochondrial apoptosis. In addition, the ROCK inhibitor Y-27632 was employed, and we found that co-treatment with Y-27632 attenuated lycorine-induced mitochondrial injury and cell apoptosis. Meanwhile, an in vivo study revealed that lycorine inhibited tumor growth and induced apoptosis in a HepG2 xenograft mouse model in association with ROCK1 activation. Taken together, all these findings suggested that lycorine induced mitochondria-dependent apoptosis through ROCK1 activation in HepG2 cells, and this may be a theoretical basis for lycorine's anticancer effects.