The mitochondrion interfering compound NPC-26 exerts potent anti-pancreatic cancer cell activity in vitro and in vivo

Cyclophilin D: Guardian or Executioner for Tumor Cells?

Cyclophilin D (CypD) is a peptide-proline cis-trans isomerase (PPIase) distributed in the mitochondrial matrix. CypD regulates the opening of the mitochondrial permeability conversion pore (mPTP) and mitochondrial bioenergetics through PPIase activity or interaction with multiple binding partners in mitochondria. CypD initially attracted attention due to its regulation of mPTP overopening-mediated cell death. However, recent studies on the effects of CypD on tumors have shown conflicting results. Although CypD has been proven to promote the aerobic glycolysis in tumor cells, its regulation of malignant characteristics such as the survival, invasion and drug resistance of tumor cells remains controversial. Here, we elaborate the main biological functions of CypD and its relationships with tumor progression identified in recent years, focusing on the dual role of CypD in tumors.

A Transcription Factor-Based Risk Model for Predicting the Prognosis of Prostate Cancer and Potential Therapeutic Drugs

Background

Prostate cancer (PC) is one of the most critical cancers affecting men's health worldwide. The development of many cancers involves dysregulation or mutations in key transcription factors. This study established a transcription factor-based risk model to predict the prognosis of PC and potential therapeutic drugs.

Materials and Methods

In this study, RNA-sequencing data were downloaded and analyzed using The Cancer Genome Atlas dataset. A total of 145 genes related to the overall survival rate of PC patients were screened using the univariate Cox analysis. The Kdmist clustering method was used to classify prostate adenocarcinoma (PRAD), thereby determining the cluster related to the transcription factors. The support vector machine-recursive feature elimination method was used to identify genes related to the types of transcription factors and the key genes specifically upregulated or downregulated were screened. These genes were further analyzed using Lasso to establish a model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for the functional analysis. The TIMER algorithm was used to quantify the abundance of immune cells in PRAD samples. The chemotherapy response of each GBM patient was predicted based on the public pharmacogenomic database, Genomics of Drug Sensitivity in Cancer (GDSC, http://www.cancerrxgene.org). The R package "pRRophetic" was applied to drug sensitivity (IC50) value prediction.

Results

We screened 10 genes related to prognosis, including eight low-risk genes and two high-risk genes. The receiver operating characteristic (ROC) curve was 0.946. Patients in the high-risk score group had a poorer prognosis than those in the low-risk score group. The average area under the curve value of the model at different times was higher than 0.8. The risk score was an independent prognostic factor. Compared with the low-risk score group, early growth response-1 (EGR1), CACNA2D1, AC005831.1, SLC52A3, TMEM79, IL20RA, CRACR2A, and FAM189A2 expressions in the high-risk score group were decreased, while AC012181.1 and TRAPPC8 expressions were increased. GO and KEGG analyses showed that prognosis was related to various cancer signaling pathways. The proportion of B_cell, T_cell_CD4, and macrophages in the high-risk score group was significantly higher than that in the low-risk score group. A total of 25 classic immune checkpoint genes were screened out to express abnormally high-risk scores, and there were significant differences. Thirty mutant genes were identified; in the high- and low-risk score groups, SPOP, TP53, and TTN had the highest mutation frequency, and their mutations were mainly missense mutations. A total of 36 potential drug candidates for the treatment of PC were screened and identified.

Conclusions

Ten genes of both high-and low-risk scores were associated with the prognosis of PC. PC prognosis may be related to immune disorders. SPOP, TP53, and TTN may be potential targets for the prognosis of PC.

NMFNA: A Non-negative Matrix Factorization Network Analysis Method for Identifying Modules and Characteristic Genes of Pancreatic Cancer

Pancreatic cancer (PC) is a highly fatal disease, yet its causes remain unclear. Comprehensive analysis of different types of PC genetic data plays a crucial role in understanding its pathogenic mechanisms. Currently, non-negative matrix factorization (NMF)-based methods are widely used for genetic data analysis. Nevertheless, it is a challenge for them to integrate and decompose different types of genetic data simultaneously. In this paper, a non-NMF network analysis method, NMFNA, is proposed, which introduces a graph-regularized constraint to the NMF, for identifying modules and characteristic genes from two-type PC data of methylation (ME) and copy number variation (CNV). Firstly, three PC networks, i.e., ME network, CNV network, and ME-CNV network, are constructed using the Pearson correlation coefficient (PCC). Then, modules are detected from these three PC networks effectively due to the introduced graph-regularized constraint, which is the highlight of the NMFNA. Finally, both gene ontology (GO) and pathway enrichment analyses are performed, and characteristic genes are detected by the multimeasure score, to deeply understand biological functions of PC core modules. Experimental results demonstrated that the NMFNA facilitates the integration and decomposition of two types of PC data simultaneously and can further serve as an alternative method for detecting modules and characteristic genes from multiple genetic data of complex diseases.

Physiopathology of the Permeability Transition Pore: Molecular Mechanisms in Human Pathology

Mitochondrial permeability transition (MPT) is the sudden loss in the permeability of the inner mitochondrial membrane (IMM) to low-molecular-weight solutes. Due to osmotic forces, MPT is paralleled by a massive influx of water into the mitochondrial matrix, eventually leading to the structural collapse of the organelle. Thus, MPT can initiate outer-mitochondrial-membrane permeabilization (MOMP), promoting the activation of the apoptotic caspase cascade and caspase-independent cell-death mechanisms. The induction of MPT is mostly dependent on mitochondrial reactive oxygen species (ROS) and Ca²⁺, but is also dependent on the metabolic stage of the affected cell and signaling events. Therefore, since its discovery in the late 1970s, the role of MPT in human pathology has been heavily investigated. Here, we summarize the most significant findings corroborating a role for MPT in the etiology of a spectrum of human diseases, including diseases characterized by acute or chronic loss of adult cells and those characterized by neoplastic initiation.

Small molecule inhibitors in pancreatic cancer

Pancreatic cancer (PC), with a 5 year survival of <7%, is one of the most fatal of all human cancers. The highly aggressive and metastatic character of this disease poses a challenge that current therapies are failing, despite significant efforts, to meet. This review examines the current status of the 35 small molecule inhibitors targeting pancreatic cancer in clinical trials and the >50 currently under investigation. These compounds inhibit biological targets spanning protein kinases, STAT3, BET, HDACs and Bcl-2 family proteins. Unsurprisingly, protein kinase inhibitors are overrepresented. Some trials show promise; a phase I combination trial of vorinostat 11 and capecitabine 17 gave a median overall survival (MoS) of 13 months and a phase II study of pazopanib 15 showed a MoS of 25 months. The current standard of care for metastatic pancreatic ductal adenocarcinoma, fluorouracil/folic acid (5-FU, Adrucil®), and gemcitabine (GEMZAR®) afforded a MoS of 23 and 23.6 months (EPAC-3 study), respectively. In patients who can tolerate the FOLFIRINOX regime, this is becoming the standard of treatment with a MoS of 11.1 months. Clinical study progress has been slow with limited improvement in patient survival relative to gemcitabine 1 monotherapy. A major cause of low PC survival is the late stage of diagnosis, occurring in patients who consider typical early stage warning signs of aches and pains normal. The selection of patients with specific disease phenotypes, the use of improved efficient drug combinations, the identification of biomarkers to specific cancer subtypes and more effective designs of investigation have improved outcomes. To move beyond the current dire condition and paucity of PC treatment options, determination of the best regimes and new treatment options is a challenge that must be met. The reasons for poor PC prognosis have remained largely unchanged for 20 years. This is arguably a consequence of significant changes in the drug discovery landscape, and the increasing pressure on academia to deliver short term 'media' friendly short-term news 'bites'. PC research sits at a pivotal point. Perhaps the greatest challenge is enacting a culture change that recognises that major breakthroughs are a result of blue sky, truly innovative and curiosity driven research.

Amentoflavone suppresses tumor growth in ovarian cancer by modulating Skp2

AIM

Ovarian cancer is one of most common malignancies in women and is associated with high reoccurrence rate and poor prognosis. This study is designed to investigate the anti-tumor effects of amentoflavone (AF), one of the major active ingredients of S. tamariscina, against ovarian cancer.

MATERIALS AND METHODS

Human ovarian cancer cell lines SKOV3 and OVCAR-3 were used in this study. The effect of AF on cell viability was examined by CCK-8 assay. Cell apoptosis and cell cycle distribution was determined by flow cytometry. ROS generation was detected using fluorescent staining. Expression of signaling molecules was determined by western blots. Xenograft model was established to evaluate the therapeutic efficacy of AF in vivo.

KEY FINDINGS

Our results showed that AF could significantly suppress cell proliferation, induce apoptosis and block cell cycle progression. Mechanistically, downregulation of S-phase kinase protein 2 (Skp2) by AF contributed to its anti-tumor effect against ovarian cancer. Furthermore, our results showed that AF repressed the expression of Skp2 through ROS/AMPK/mTOR signaling. The anti-tumor effect of AF against ovarian cancer was also confirmed in a xenograft animal model.

SIGNIFICANCE

Overall, our present findings highlighted the potential of AF in the treatment of ovarian cancer. Moreover, our study also provided a new elucidation regarding the anti-tumor mechanisms of AF.

Activation of AMPK by OSU53 protects spinal cord neurons from oxidative stress

The present study tested the potential effect of OSU53, a novel AMPK activator, against hydrogen peroxide (H2O2)-induced spinal cord neuron damages. Treatment with OSU53 attenuated H2O2-induced death and apoptosis of primary murine spinal cord neurons. OSU53 activated AMPK signaling, which is required for its actions in spinal cord neurons. The AMPK inhibitor Compound C or AMPKα1 siRNA almost abolished OSU53-mediated neuroprotection against H2O2. On the other hand, sustained-activation of AMPK by introducing the constitutive-active AMPKα1 mimicked OSU53's actions, and protected spinal cord neurons from oxidative stress. OSU53 significantly attenuated H2O2-induced reactive oxygen species production, lipid peroxidation and DNA damages in spinal cord neurons. Additionally, OSU53 increased NADPH content and heme oxygenase-1 mRNA expression in H2O2-treated spinal cord neurons. Together, we indicate that targeted-activation of AMPK by OSU53 protects spinal cord neurons from oxidative stress.

NPC-26 kills human colorectal cancer cells via activating AMPK signaling

NPC-26 is novel mitochondrion-interfering compound. The current study tested its potential effect against colorectal cancer (CRC) cells. We demonstrated that NPC-26 induced potent anti-proliferative and cytotoxic activities against CRC cell lines (HCT-116, DLD-1 and HT-29). Activation of AMP-activated protein kinase (AMPK) signaling mediated NPC-26-induced CRC cell death. AMPKα1 shRNA knockdown or dominant negative mutation abolished NPC-26-induced AMPK activation and subsequent CRC cell death. NPC-26 disrupted mitochondrial function, causing mitochondrial permeability transition pore (mPTP) opening and reactive oxygen species (ROS) production. ROS scavengers (NAC or MnTBAP) and mPTP blockers (cyclosporin A or sanglifehrin A) blocked NPC-26-induced AMPK activation and attenuated CRC cell death. Significantly, intraperitoneal injection of NPC-26 potently inhibited HCT-116 tumor growth in severe combined immuno-deficient (SCID) mice. Yet, its anti-tumor activity was significantly weakened against AMPKα1-silenced HCT-116 tumors. Together, we conclude that NPC-26 kills CRC cells possibly via activating AMPK signaling.

AntagomiR-451 inhibits oxygen glucose deprivation (OGD)-induced HUVEC necrosis via activating AMPK signaling

Oxygen glucose deprivation (OGD) application in cultured human umbilical vein endothelial cells (HUVECs) mimics ischemic injuries. AntagomiR-451, the miroRNA-451 ("miR-451") inhibitor, could activate pro-survival AMP-activated protein kinase (AMPK) signaling. In the current study, we showed that forced-expression of antagomiR-451 depleted miRNA-451 and significantly attenuated OGD-induced necrosis of HUVECs. Activation of AMPK was required for antagomiR-451-mediated pro-survival actions. AMPK inhibition, by AMPKα shRNA or dominant negative mutation, almost completely abolishedantagomiR-451-mediated HUVEC protection again OGD. Reversely, forced-activation of AMPK by exogenous expression of constructively-active AMPKα inhibited OGD-induced HUVEC necrosis. At the molecular level, antagomiR-451 expression in HUVECs inhibited OGD-induced programmed necrosis, the latter was evidenced by mitochondrial p53-cyclophilinD (Cyp-D) association, mitochondrial depolarization as well as reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) breach. Together, we suggest that antagomiR-451 activates AMPK to inhibit OGD-induced programmed necrosis in HUVECs.

CC-223 blocks mTORC1/C2 activation and inhibits human hepatocellular carcinoma cells in vitro and in vivo

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related human mortalities. Over-activation of mammalian target of rapamycin (mTOR) is important for HCC tumorigenesis and progression. The current study assessed the potential anti-HCC activity by a novel mTOR kinase inhibitor, CC-223. We demonstrate that CC-223, at nM concentrations, induced profound cytotoxic and anti-proliferative activities against established HCC cell lines (HepG2, KYN-2 and Huh-7) and primary human HCC cells. Meanwhile, CC-223 activated caspase-3/-9 and apoptosis in the above HCC cells. CC-223 concurrently blocked mTORC1 and mTORC2 activation, and its cytotoxicity against HCC cells was much more potent than the traditional mTORC1 inhibitors (RAD001 and rapamycin). Further studies demonstrated that CC-223 disrupted mitochondrial function, and induced mitochondrial permeability transition pore (mPTP) opening and reactive oxygen species (ROS) production. On the other hand, ROS scavengers and mPTP blockers (cyclosporin A or sanglifehrin A) largely attenuated CC-223-induced HepG2 cell apoptosis. In vivo studies showed that oral administration of CC-223 dramatically inhibited growth of HepG2 xenografts in severe combined immuno-deficient (SCID) mice. mTORC1/2 activation was also blocked in xenografts with CC-223 administration. Together, CC-223 simultaneously blocks mTORC1/2 and efficiently inhibits human HCC cells.

GSK1059615 kills head and neck squamous cell carcinoma cells possibly via activating mitochondrial programmed necrosis pathway

This study tested the anti-head and neck squamous cell carcinoma (HNSCC) cell activity by GSK1059615, a novel PI3K and mTOR dual inhibitor. GSK1059615 inhibited survival and proliferation of established (SCC-9, SQ20B and A253 lines) and primary human HNSCC cells. GSK1059615 blocked PI3K-AKT-mTOR activation in HNSCC cells. Intriguingly, GSK1059615 treatment in HNSCC cells failed to provoke apoptosis, but induced programmed necrosis. The latter was tested by mitochondria depolarization, ANT-1-cyclophilin-D mitochondrial association and lactate dehydrogenase (LDH) release. Reversely, mPTP blockers (sanglifehrin A, cyclosporin A and bongkrekic acid) or cyclophilin-D shRNA dramatically alleviated GSK1059615-induced SCC-9 cell death. Further studies demonstrated that GSK1059615 i.p. injection suppressed SCC-9 tumor growth in nude mice, which was compromised with co-administration with cyclosporin A. Thus, targeting PI3K-AKT-mTOR pathway by GSK1059615 possibly provokes programmed necrosis pathway to kill HNSCC cells.