Sphingosine kinase-1 enhances resistance to apoptosis through activation of PI3K/Akt/NF-κB pathway in human non-small cell lung cancer

Thymoquinone, artemisinin, and thymol attenuate proliferation of lung cancer cells as Sphingosine kinase 1 inhibitors

Sphingosine-1-phosphate (S1P) formed via catalytic actions of sphingosine kinase 1 (SphK1) behaves as a pro-survival substance and activates downstream target molecules associated with various pathologies, including initiation, inflammation, and progression of cancer. Here, we aimed to investigate the SphK1 inhibitory potentials of thymoquinone (TQ), Artemisinin (AR), and Thymol (TM) for the therapeutic management of lung cancer. We implemented docking, molecular dynamics (MD) simulations, enzyme inhibition assay, and fluorescence measurement studies to estimate binding affinity and SphK1 inhibitory potential of TQ, AR, and TM. We further investigated the anti-cancer potential of these compounds on non-small cell lung cancer (NSCLC) cell lines (H1299 and A549), followed by estimation of mitochondrial ROS, mitochondrial membrane potential depolarization, and cleavage of DNA by comet assay. Enzyme activity and fluorescence binding studies suggest that TQ, AR, and TM significantly inhibit the activity of SphK1 with IC50 values of 35.52 µM, 42.81 µM, and 53.68 µM, respectively, and have an excellent binding affinity. TQ shows cytotoxic effect and anti-proliferative potentials on H1299 and A549 with an IC50 value of 27.96 µM and 54.43 µM, respectively. Detection of mitochondrial ROS and mitochondrial membrane potential depolarization shows promising TQ-induced oxidative stress on H1299 and A549 cell lines. Comet assay shows promising TQ-induced oxidative DNA damage. In conclusion, TQ, AR, and TM act as potential inhibitors for SphK1, with a strong binding affinity. In addition, the cytotoxicity of TQ is linked to oxidative stress due to mitochondrial ROS generation. Overall, our study suggests that TQ is a promising inhibitor of SphK1 targeting lung cancer therapy.

GSTO1 aggravates EGFR-TKIs resistance and tumor metastasis via deglutathionylation of NPM1 in lung adenocarcinoma

Despite significantly improved clinical outcomes in EGFR-mutant lung adenocarcinoma, all patients develop acquired resistance and malignancy on the treatment of EGFR tyrosine kinase inhibitors (EGFR-TKIs). Understanding the resistance mechanisms is crucial to uncover novel therapeutic targets to improve the efficacy of EGFR-TKI treatment. Here, integrated analysis using RNA-Seq and shRNAs metabolic screening reveals glutathione S-transferase omega 1 (GSTO1) as one of the key metabolic enzymes that is required for EGFR-TKIs resistance in lung adenocarcinoma cells. Aberrant upregulation of GSTO1 confers EGFR-TKIs resistance and tumor metastasis in vitro and in vivo dependent on its active-site cysteine 32 (C32). Pharmacological inhibition or knockdown of GSTO1 restores sensitivity to EGFR-TKIs and synergistically enhances tumoricidal effects. Importantly, nucleophosmin 1 (NPM1) cysteine 104 is deglutathionylated by GSTO1 through its active C32 site, which leads to activation of the AKT/NF-κB signaling pathway. In addition, clinical data illustrates that GSTO1 level is positively correlated with NPM1 level, NF-κB-mediated transcriptions and progression of human lung adenocarcinoma. Overall, our study highlights a novel mechanism of GSTO1 mediating EGFR-TKIs resistance and malignant progression via protein deglutathionylation, and GSTO1/NPM1/AKT/NF-κB axis as a potential therapeutic vulnerability in lung adenocarcinoma.

S1P Signaling Genes as Prominent Drivers of BCR-ABL1-Independent Imatinib Resistance and Six Herbal Compounds as Potential Drugs for Chronic Myeloid Leukemia

Imatinib (IM), a breakthrough in chronic myeloid leukemia (CML) treatment, is accompanied by discontinuation challenges owing to drug intolerance. Although BCR-ABL1 mutation is a key cause of CML resistance, understanding mechanisms independent of BCR-ABL1 is also important. This study investigated the sphingosine-1-phosphate (S1P) signaling-associated genes (SphK1 and S1PRs) and their role in BCR-ABL1-independent resistant CML, an area currently lacking investigation. Through comprehensive transcriptomic analysis of IM-sensitive and IM-resistant CML groups, we identified the differentially expressed genes and found a notable upregulation of SphK1, S1PR2, and S1PR5 in IM-resistant CML. Functional annotation revealed their roles in critical cellular processes such as proliferation and GPCR activity. Their network analysis uncovered significant clusters, emphasizing the interconnectedness of the S1P signaling genes. Further, we identified interactors such as BIRC3, TRAF6, and SRC genes, with potential implications for IM resistance. Additionally, receiver operator characteristic curve analysis suggested these genes' potential as biomarkers for predicting IM resistance. Network pharmacology analysis identified six herbal compounds-ampelopsin, ellagic acid, colchicine, epigallocatechin-3-gallate, cucurbitacin B, and evodin-as potential drug candidates targeting the S1P signaling genes. In summary, this study contributes to efforts to better understand the molecular mechanisms underlying BCR-ABL1-independent CML resistance. Moreover, the S1P signaling genes are promising therapeutic targets and plausible new innovation avenues to combat IM resistance in cancer clinical care in the future.

Identification and immunological characteristics of anoikis-associated molecular clusters in lung adenocarcinoma

Anoikis plays a crucial role in the progression, prognosis, and immune response of lung adenocarcinoma (LUAD). However, its specific impact on LUAD remains unclear. In this study, we investigated the intricate interplay of nesting apoptotic factors in LUAD. By analyzing nine key nesting apoptotic factors, we categorized LUAD patients into two distinct clusters. Further examination of immune cell profiles revealed that Cluster A exhibited greater infiltration of innate immune cells than did Cluster B. Additionally, we identified two genes closely associated with prognosis and developed a predictive model to differentiate patients based on molecular clusters. Our findings suggest that the loss of specific anoikis-related genes could significantly influence the prognosis, tumor microenvironment, and clinical features of LUAD patients. Furthermore, we validated the expression and functional roles of two pivotal prognostic genes, solute carrier family 2 member 1 (SLC2A1) and sphingosine kinase 1 (SPHK1), in regulating tumor cell viability, migration, apoptosis, and anoikis. These results offer valuable insights for future mechanistic investigations. In conclusion, this study provides new avenues for advancing our understanding of LUAD, improving prognostic assessments, and developing more effective immunotherapy strategies.

The impacts of SphK1 on inflammatory response and oxidative stress in LPS-induced ALI/ARDS

As severe conditions, acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) threaten human health. Inflammation and oxidative stress play a vital role in the pathogenesis of ALI/ARDS. Sphingosine kinase 1 (SphK1) significantly contributes to mediating inflammatory responses. Nevertheless, the impact of SphK1 on lipopolysaccharide (LPS)-triggered ALI/ARDS remains largely undetermined. In our current work, we explored the impact of SphK1 on ALI/ARDS using a mouse model. We studied whether it could reduce LPS-triggered inflammatory response and oxidative stress by suppressing SphK1 in ALI/ARDS. The mice were treated with the inhibitor of SphK1 (N,N-dimethylsphingosine, DMS) before intraperitoneal injection of LPS. Moreover, we assessed the survival rate, and several parameters, such as the lung wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and the release of inflammatory cytokines. Western blotting analysis was adopted to evaluate the levels of phosphoinositide 3-kinase (PI3K)/serine/threonine kinase (AKT) pathways. We showed that the inhibitor of SphK1 not only ameliorated LPS-stimulated lung histopathological changes and W/D ratio of lung tissue but also elevated the survival rate, the SOD activity and decreased the MDA content, MPO activity, interleukin-6 (IL-6) and tumor necrosis factor-ɑ (TNF-ɑ) production by regulating the PI3K/AKT signaling pathway in lung tissue. Taken together, SphK1 played an essential role in inflammatory responses and oxidative stress. The underlying mechanism might be linked to the activation and up-regulation of the PI3K/AKT signaling pathway in LPS-triggered ALI/ARDS.

Berberine ameliorate inflammation and apoptosis via modulating PI3K/AKT/NFκB and MAPK pathway on dry eye

BACKGROUND

Dry eye disease (DED) is a multifactorial disease in ocular surface, and inflammation plays an etiological role. Berberine (BBR) has shown efficacy in treating inflammatory diseases. Yet, there was no adequate information related to the therapeutic effects of BBR for DED.

PURPOSE

To detect the effects and explore the potential mechanisms of BBR on DED.

STUDY DESIGN

In vitro, in vivo study and network pharmacology analysis were involved.

METHOD

The human corneal epithelium cells viability was evaluated with different concentrations of BBR. Dry eye murine model was established by exposing to the desiccating stress, and Ciclosporin (CSA), BBR eye drops or vehicle were topical administration for 7 days. The phenol red cotton tests, Oregon-green-dextran staining and Periodic acid-Schiff staining were performed and evaluated the dry eye after treatment. Inflammation and apoptosis levels of ocular surface were quantified. The potential targets related to berberine and dry eye were collected from databases. The Protein-Protein interaction network analysis and GO & KEGG enrichment analysis were realized by STRING database, Metascape platform and Cytoscape software to find core targets and signaling pathways. The SchrÖdinger software was used to molecular docking and PyMOL software to visualization. Finally, the levels of PI3K/AKT/NFκB and MAPK pathways were detected.

RESULT

The data revealed BBR could rescue impaired HCE under hyperosmotic conditions. In addition, BBR eye drops could ameliorate dry eye. And BBR eye drops suppressed the inflammatory factors and CD4+T cells infiltration in conjunctiva. Besides, BBR eye drops protected ocular surface by avoiding the severe apoptosis and decreasing the level of MMP-3 and MMP-9. 148 common targets intersection between BBR and dry eye were found via network pharmacology analysis. Core proteins and core pathways were identified through PPI and GO&KEGG enrichment analysis. Molecular docking displayed excellent binding between BBR and those core targets. Finally, in vivo study verified that BBR eye drops had a therapeutic effect in dry eye by inhibiting PI3K/AKT/NFκB and MAPK pathways.

CONCLUSION

The research provided convincing evidence that BBR could be a candidate drug for dry eye.

Recent advances in natural compounds inducing non-apoptotic cell death for anticancer drug resistance

The induction of cell death is recognized as a potent strategy for cancer treatment. Apoptosis is an extensively studied form of cell death, and multiple anticancer drugs exert their therapeutic effects by inducing it. Nonetheless, apoptosis evasion is a hallmark of cancer, rendering cancer cells resistant to chemotherapy drugs. Consequently, there is a growing interest in exploring novel non-apoptotic forms of cell death, such as ferroptosis, necroptosis, pyroptosis, and paraptosis. Natural compounds with anticancer properties have garnered significant attention due to their advantages, including a reduced risk of drug resistance. Over the past two decades, numerous natural compounds have been discovered to exert anticancer and anti-resistance effects by triggering these four non-apoptotic cell death mechanisms. This review primarily focuses on these four non-apoptotic cell death mechanisms and their recent advancements in overcoming drug resistance in cancer treatment. Meanwhile, it highlights the role of natural compounds in effectively addressing cancer drug resistance through the induction of these forms of non-apoptotic cell death.

Targeting SphK1/2 by SKI-178 inhibits prostate cancer cell growth

Sphingosine kinases (SphK), including SphK1 and SphK2, are important enzymes promoting progression of prostate cancer. SKI-178 is a novel and highly potent SphK1/2 dual inhibitor. We here tested the potential anti-prostate cancer cell activity of SKI-178. Bioinformatics analyses and results from local tissues demonstrated that that both SphK1 and SphK2 are upregulated in human prostate cancer tissues. Ectopic overexpression of SphK1 and SphK2, by lentiviral constructs, promoted primary prostate cancer cell proliferation and migration. In primary human prostate cancer cells and immortalized cell lines, SKI-178 potently inhibited cell viability, proliferation, cell cycle progression and cell migration, causing robust cell death and apoptosis. SKI-178 impaired mitochondrial functions, causing mitochondrial depolarization, reactive oxygen species production and ATP depletion.SKI-178 potently inhibited SphK activity and induced ceramide production, without affecting SphK1/2 expression in prostate cancer cells. Further, SKI-178 inhibited Akt-mTOR activation and induced JNK activation in prostate cancer cells. Contrarily, a constitutively-active Akt1 construct or the pharmacological JNK inhibitors attenuated SKI-178-induced cytotoxicity in prostate cancer cells. In vivo, daily intraperitoneal injection of a single dose of SKI-178 potently inhibited PC-3 xenograft growth in nude mice. SphK inhibition, ceramide production, ATP depletion and lipid peroxidation as well as Akt-mTOR inactivation and JNK activation were detected in PC-3 xenograft tissues with SKI-178 administration. Together, targeting SphK1/2 by SKI-178 potently inhibited prostate cancer cell growth in vitro and in vivo.

Effect of Gubenyiliu formula II and its disassembled prescriptions on cell autophagy in breast cancer through PI3K/AKT/mTOR pathway

The aim of this study is to reveal the mechanism of Gubenyiliu II (GYII) inhibiting autophagy in breast cancer and the effect of its disassembled prescriptions, Quxie (QX) and Fuzheng (FZ), which cause autophagy difference on tumor growth. After a breast cancer in situ tumor model was established, mice were randomly distributed into different groups: model, GYII, QX, FZ and tamoxifen groups, and treated correspondingly. Then, the tumor volumes and weights were monitored. Immunohistochemistry detected the contents of microtubule-associated protein light chain 3 (LC3), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), phosphorylated protein kinase B (p-AKT) and phosphorylated mammalian target of rapamycin (p-mTOR) in tumor tissues. Furthermore, 4T1 cells were administrated with the 20% contained serum. Cell proliferation, migration and invasion were measured using cell counting kit-8 and transwell assays. Electron microscopy and flow cytometry detected autophagy and apoptosis. The content of LC3 was measured by immunofluorescence. Western blot detected the protein levels of LC3, Beclin1, p-PI3K/PI3K, p-AKT/AKT and p-mTOR/mTOR in tumor tissues and 4T1 cells. GYII, QX and FZ treatment significantly reduced the tumor volumes and weights in breast cancer tumor-bearing mice. The cell proliferation, migration and invasion were restrained, and cell apoptosis and autophagy were promoted in GYII, QX and FZ groups. Moreover, GYII, QX and FZ increased the expression of LC3 in 4T1 cells and tumor tissues and decreased the phosphorylation levels of PI3K, AKT and mTOR in tumor tissues. The protein levels of LC3 and Beclin1 were upregulated, and p-PI3K/PI3K, p-AKT/AKT and p-mTOR/mTOR were downregulated in tumor tissues and 4T1 cells of treatment groups. Our study confirmed that GYII could treat breast cancer by restraining the PI3K/AKT/mTOR signaling pathway-mediated autophagy. While QX focuses on inhibiting tumor growth, FZ acts on inhibiting tumor metastasis.

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.

HOXC11 drives lung adenocarcinoma progression through transcriptional regulation of SPHK1

Lung adenocarcinoma (LUAD) is a fatal threat to human health, while the mechanism remains unclear, and the therapy brings limited therapeutic effects. Transcription factor Homeobox C11 (HOXC11) was previously proved to be related to hind limbs and metanephric development during the embryonic phase, and its role in tumors has been gradually recognized. Our study found that HOXC11 overexpressed in LUAD and was associated with worse overall survival. Moreover, its expression in lung cancer was regulated by IκB kinase α (IKKα), a pivotal kinase in NF-κB signaling, which was related to the ubiquitination of HOXC11. We further proved that HOXC11 could enhance the ability of proliferation, migration, invasion, colony formation, and the progression of the cell cycle in LUAD cells. Meanwhile, it also accelerated the formation of subcutaneous and lung metastases tumors. In contrast, loss of HOXC11 in LUAD cells significantly inhibited these malignant phenotypes. At the same time, HOXC11 regulated the expression of sphingosine kinase 1 (SPHK1) by directly binding to its promoter region. Therefore, we conclude that HOXC11 impacts the development of LUAD and facilitates lung cancer progression by promoting the expression of SPHK1.

Polysaccharide from fermented mycelium of Inonotus obliquus attenuates the ulcerative colitis and adjusts the gut microbiota in mice

Ulcerative colitis (UC) is a disease characterized by chronic inflammation of the colon. Polysaccharides not only have biological activities but also can regulate gut microbiota to alleviate the symptoms of UC. In this study, polysaccharide extracted from mycelium of Inonotus obliquus (IOP) was prescribed to treat UC induced by dextran sodium sulfate (DSS) in mice. Compared to model control group (MC), IOP-Low, IOP-Medium and IOP-High (IOP-L, IOP-M and IOP-H) treatment groups increased the body weight rate by 6.0%-9.6%, colon length by 8.57%-25.14% and superoxide dismutase (SOD) activity by 53.8-110.4 U/mg, while decreased the malondialdehyde (MDA) content by 37.4%-64.8%, myeloperoxidase (MPO) activity by 29.0%-46.9%, and the concentration of nitric oxide (NO) by 24.8-35.6 μmol/L. IOP treatment also promoted the secretion of interleukin (IL)-10 but suppressed those of interleukin (IL)-6, interleukin (IL)-1β and tumor necrosis factor (TNF)-α. Simultaneously, analysis of high-throughput sequencing indicated that IOP reduced the ratio of Firmicutes to Bacteroidetes (F/B) at phylum level, and increased the relative abundance of Bacteroides and Lactobacillus at genus level. In brief, IOP may be a promising alternative medicine for UC remedy by regulating the anti-inflammatory level, the anti-oxidative ability and the gut microbiota composition.

Recent progress in targeted therapy for non-small cell lung cancer

The high morbidity and mortality of non-small cell lung cancer (NSCLC) have always been major threats to people's health. With the identification of carcinogenic drivers in non-small cell lung cancer and the clinical application of targeted drugs, the prognosis of non-small cell lung cancer patients has greatly improved. However, in a large number of non-small cell lung cancer cases, the carcinogenic driver is unknown. Identifying genetic alterations is critical for effective individualized therapy in NSCLC. Moreover, targeted drugs are difficult to apply in the clinic. Cancer drug resistance is an unavoidable obstacle limiting the efficacy and application of targeted drugs. This review describes the mechanisms of targeted-drug resistance and newly identified non-small cell lung cancer targets (e.g., KRAS G12C, NGRs, DDRs, CLIP1-LTK, PELP1, STK11/LKB1, NFE2L2/KEAP1, RICTOR, PTEN, RASGRF1, LINE-1, and SphK1). Research into these mechanisms and targets will drive individualized treatment of non-small cell lung cancer to generate better outcomes.

Crosstalk between pro-survival sphingolipid metabolism and complement signaling induces inflammasome-mediated tumor metastasis

Crosstalk between metabolic and signaling events that induce tumor metastasis remains elusive. Here, we determine how oncogenic sphingosine 1-phosphate (S1P) metabolism induces intracellular C3 complement activation to enhance migration/metastasis. We demonstrate that increased S1P metabolism activates C3 complement processing through S1P receptor 1 (S1PR1). S1P/S1PR1-activated intracellular C3b-α'2 is associated with PPIL1 through glutamic acid 156 (E156) and aspartic acid 111 (D111) residues, resulting in NLRP3/inflammasome induction. Inactivation mutations of S1PR1 to prevent S1P signaling or mutations of C3b-α'2 to prevent its association with PPIL1 attenuate inflammasome activation and reduce lung colonization/metastasis in mice. Also, activation of the S1PR1/C3/PPIL1/NLRP3 axis is highly associated with human metastatic melanoma tissues and patient-derived xenografts. Moreover, targeting S1PR1/C3/PPIL1/NLRP3 signaling using molecular, genetic, and pharmacologic tools prevents lung colonization/metastasis of various murine cancer cell lines using WT and C3a-receptor1 knockout (C3aR1-/-) mice. These data provide strategies for treating high-grade/metastatic tumors by targeting the S1PR1/C3/inflammasome axis.

Sphingosine kinase 1 promotes growth of glioblastoma by increasing inflammation mediated by the NF-κB /IL-6/STAT3 and JNK/PTX3 pathways

Glioblastoma (GBM) is the most challenging malignant tumor of the central nervous system because of its high morbidity, mortality, and recurrence rate. Currently, mechanisms of GBM are still unclear and there is no effective drug for GBM in the clinic. Therefore, it is urgent to identify new drug targets and corresponding drugs for GBM. In this study, in silico analyses and experimental data show that sphingosine kinase 1 (SPHK1) is up-regulated in GBM patients, and is strongly correlated with poor prognosis and reduced overall survival. Overexpression of SPHK1 promoted the proliferation, invasion, metastasis, and clonogenicity of GBM cells, while silencing SPHK1 had the opposite effect. SPHK1 promoted inflammation through the NF-κB/IL-6/STAT3 signaling pathway and led to the phosphorylation of JNK, activating the JNK-JUN and JNK-ATF3 pathways and promoting inflammation and proliferation of GBM cells by transcriptional activation of PTX3. SPHK1 interacted with PTX3 and formed a positive feedback loop to reciprocally increase expression, promote inflammation and GBM growth. Inhibition of SPHK1 by the inhibitor, PF543, also decreased tumorigenesis in the U87-MG and U251-MG SPHK1 orthotopic mouse models. In summary, we have characterized the role and molecular mechanisms by which SPHK1 promotes GBM, which may provide opportunities for SPHK1-targeted therapy.

Long Intergenic Non-Protein Coding RNA 173 in Human Cancers

Long non-coding RNAs belong to non-coding RNAs (ncRNAs) with a length of more than 200 nucleotides and limited protein-coding ability. Growing research has clarified that dysregulated lncRNAs are correlated with the development of various complex diseases, including cancer. LINC00173 has drawn researchers' attention as one of the recently discovered lncRNAs. Aberrant expression of LINC00173 affects the initiation and progression of human cancers. In the present review, we summarize the recent considerable research on LINC00173 in 11 human cancers. Through the summary of the abnormal expression of LINC00173 and its potential molecular regulation mechanism in cancers, this article indicates that LINC00173 may serve as a potential diagnostic biomarker and a target for drug therapy, thus providing novel clues for future related research.

Epimesatines A-I, nine undescribed prenylated flavonoids with SPHK1 inhibitory activities from Epimedium sagittatum maxim

Epimesatines A-I, nine undescribed prenylated flavonoids, along with ten known analogues, were isolated from the aerial parts of Epimedium sagittatum Maxim. The structures and absolute configurations of epimesatines A-I were determined using a combination of spectroscopic data, Rh₂(OCOCF₃)₄-induced electronic circular dichroism (ECD) experiments, ECD comparisons, and X-ray crystallography analysis. Epimesatines A and I displayed notable activities on the viabilities of human non-small cell lung cancer (NSCLC) A549 cells with IC₅₀ values of 1.77 and 9.97 μM, respectively. Furthermore, epimesatines A and I significantly inhibited the expression of sphingosine kinase 1 (SPHK1) in A549 cells. In addition, none of these compounds showed obvious toxicity on normal human lung bronchial epithelial BEAS-2B cells.

Serum Metabolomics Profiling Reveals Metabolic Alterations Prior to a Diagnosis with Non-Small Cell Lung Cancer among Chinese Community Residents: A Prospective Nested Case-Control Study

The present high mortality of lung cancer in China stems mainly from the lack of feasible, non-invasive and early disease detection biomarkers. Serum metabolomics profiling to reveal metabolic alterations could expedite the disease detection process and suggest those patients who are harboring disease. Using a nested case-control design, we applied ultra-high-performance liquid chromatography/mass spectrometry (LC-MS)-based serum metabolomics to reveal the metabolomic alterations and to indicate the presence of non-small cell lung cancer (NSCLC) using serum samples collected prior to disease diagnoses. The studied serum samples were collected from 41 patients before a NSCLC diagnosis (within 3.0 y) and 38 matched the cancer-free controls from the prospective Shanghai Suburban Adult Cohort. The NSCLC patients markedly presented cellular metabolism alterations in serum samples collected prior to their disease diagnoses compared with the cancer-free controls. In total, we identified 18 significantly expressed metabolites whose relative abundance showed either an upward or a downward trend, with most of them being lipid and lipid-like molecules, organic acids, and nitrogen compounds. Choline metabolism in cancer, sphingolipid, and glycerophospholipid metabolism emerged as the significant metabolic disturbance of NSCLC. The metabolites involved in these biological processes may be the distinctive features associated with NSCLC prior to a diagnosis.

Deciphering the pharmacological mechanisms of Scutellaria baicalensis Georgi on oral leukoplakia by combining network pharmacology, molecular docking and experimental evaluations

BACKGROUND

Oral leukoplakia (OLK), an uncharacterized pathological condition that occurs as a white patch in the oral mucosa, is the most common precancerous condition. Scutellaria baicalensis Georgi (SBG) is a medicinal plant with a wide range of pharmacological effects. Increased evidence shows that SBG has potential therapeutic effects on OLK. However, the therapeutic mechanisms of SBG against OLK have not yet been completely elucidated.

PURPOSE

This study aimed to clarify the active components and multi-target mechanisms of SBG against OLK via network pharmacology, molecular docking and experimental evaluations.

STUDY DESIGN AND METHODS

The active components and related targets of SBG were screened by the TCMSP database and Swiss Target Prediction database. Potential therapeutic targets of OLK were collected using the GeneCards and OMIM databases. Then, we established protein-protein interaction (PPI), compound-target-disease (C-T-D), and compound-target-pathway (C-T-P) networks by Cytoscape to identify the main components, core targets, and pharmacological pathways of SBG against OLK via applying data mining techniques and topological parameters. Metascape database was utilized for GO and KEGG pathway analysis. Molecular docking techniques were used to estimate the binding force between the components and the hub genes. Subsequently, a series of in vitro experiments, specifically CCK-8 assay, clone formation assay, wound healing assay, flow cytometry, RT-qPCR and western blotting were conducted for further verification.

RESULTS

There were 25 active components and 31 related target genes in SBG against OLK. PPI analysis showed that Akt1, VEGFA, EGFR, HIF1A and PTGS2 shared the highest centrality among all target genes. KEGG pathway analysis found that PI3K-Akt signaling pathway may occupy core status in the anti-OLK system. Molecular docking results showed that the main active components of SBG had a strong binding affinity to the hub genes. In vitro experiments showed that the leading component baicalein may inhibit proliferation, block cells in the S phase, induce DOK cell apoptosis, and downregulate the mRNA expression of 5 hub genes by inhibiting PI3K/Akt signaling pathway activation.

CONCLUSION

The most predominant component of SBG against OLK was baicalein and the key pathway was PI3K/Akt. The main components and hub genes had robust binding abilities. In vitro experiments showed that baicalein could inhibit the proliferation of DOK cells, induce apoptosis, block the cell cycle, and inhibit the mRNA expression level of the hub genes by inhibiting the PI3K/Akt pathway.

Targeting sphingosine kinase 1/2 by a novel dual inhibitor SKI-349 suppresses non-small cell lung cancer cell growth

Sphingosine kinase 1 (SphK1) and sphingosine kinase (SphK2) are both important therapeutic targets of non-small cell lung cancer (NSCLC). SKI-349 is a novel, highly efficient and small molecular SphK1/2 dual inhibitor. Here in primary human NSCLC cells and immortalized cell lines, SKI-349 potently inhibited cell proliferation, cell cycle progression, migration and viability. The dual inhibitor induced mitochondrial depolarization and apoptosis activation in NSCLC cells, but it was non-cytotoxic to human lung epithelial cells. SKI-349 inhibited SphK activity and induced ceramide accumulation in primary NSCLC cells, without affecting SphK1/2 expression. SKI-349-induced NSCLC cell death was attenuated by sphingosine-1-phosphate and by the SphK activator K6PC-5, but was potentiated by the short-chain ceramide C6. Moreover, SKI-349 induced Akt-mTOR inactivation, JNK activation, and oxidative injury in primary NSCLC cells. In addition, SKI-349 decreased bromodomain-containing protein 4 (BRD4) expression and downregulated BRD4-dependent genes (Myc, cyclin D1 and Klf4) in primary NSCLC cells. At last, SKI-349 (10 mg/kg) administration inhibited NSCLC xenograft growth in nude mice. Akt-mTOR inhibition, JNK activation, oxidative injury and BRD4 downregulation were detected in SKI-349-treated NSCLC xenograft tissues. Taken together, targeting SphK1/2 by SKI-349 potently inhibits NSCLC cell growth in vitro and in vivo.

Metabolomic Analysis Reveals that SPHK1 Promotes Oral Squamous Cell Carcinoma Progression through NF-κB Activation

BACKGROUND

Metabolic disorders are significant in the occurrence and development of malignant tumors. Changes of specific metabolites and metabolic pathways are molecular therapeutic targets. This study aims to determine the metabolic differences between oral squamous cell carcinoma (OSCC) tissues and paired adjacent noncancerous tissues (ANT) through liquid chromatography-mass spectrometry (LC-MS). SPHK1 is a key enzyme in sphingolipid metabolism. This study also investigates the potential role of SPHK1 in OSCC.

MATERIALS AND METHODS

This study used LC-MS to analyze metabolic differences between OSCC tissues and paired ANT. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were applied to explain the significance of phospholipid metabolism pathways in the occurrence and development of OSCC. Through further experiments, we confirmed the oncogenic phenotypes of SPHK1 in vitro and in vivo, including proliferation, migration, and invasion.

RESULTS

The sphingolipid metabolic pathway was significantly activated in OSCC, and the key enzyme SPHK1 was significantly upregulated in oral cancer tissues, predicting poor OSCC prognosis. In this study, SPHK1 overexpression was associated with high-grade malignancy and poor OSCC prognosis. SPHK1 targeted NF-κB by facilitating p65 expression to regulate OSCC tumor progression and promote metastasis.

CONCLUSIONS

This study identified metabolic differences between OSCC and paired ANT, explored the carcinogenic role of overexpressed SPHK1, and revealed the association of SPHK1 with poor OSCC prognosis. SPHK1 targets NF-κB signaling by facilitating p65 expression to regulate tumor progression and promote tumor metastasis, providing potential therapeutic targets for diagnosing and treating oral tumors.

Sphingolipid Metabolism and Signaling in Lung Cancer: A Potential Therapeutic Target

Sphingolipids are important bioactive lipids that not only play an important role in maintaining the barrier function and fluidity of cell membranes but also regulate multiple processes in cancer development by controlling multiple signaling pathways in the signal transduction network. Dysregulation of sphingolipid metabolism is thought to be one of the most important dysregulated pathways in lung cancer, the most prevalent type of cancer in terms of incidence and mortality worldwide. This article focuses on lung cancer, reviewing the important lipids in sphingolipid metabolism and the related enzymes in relation to lung cancer progression and their effects on the tumor microenvironment and discussing their roles in the diagnosis and treatment of lung cancer.

Pathway-Based Analysis Revealed the Role of Keap1-Nrf2 Pathway and PI3K-Akt Pathway in Chinese Esophageal Squamous Cell Carcinoma Patients With Definitive Chemoradiotherapy

Esophageal squamous cell carcinoma (ESCC) is the major type of EC in China. Chemoradiotherapy is a standard definitive treatment for early-stage EC and significantly improves local control and overall survival for late-stage patients. However, chemoradiotherapy resistance, which limits therapeutic efficacy and treatment-induced toxicity, is still a leading problem for treatment break. To optimize the selection of ESCC patients for chemoradiotherapy, we retrospectively analyzed the clinical features and genome landscape of a Chinese ESCC cohort of 58 patients. TP53 was the most frequent mutation gene, followed by NOTCH1. Frequently, copy number variants were found in MCL1 (24/58, 41.4%), FGF19 (23/58, 39.7%), CCND1 (22/58, 37.9%), and MYC (20/58, 34.5%). YAP1 and SOX2 amplifications were mutually exclusive in this cohort. Using univariate and multivariate analyses, the YAP1 variant and BRIP1 mutant were identified as adverse factors for OS. Patients with PI3K-Akt pathway alterations displayed longer PFS and OS than patients with an intact PI3K-Akt pathway. On the contrary, two patients with Keap1-Nrf2 pathway alterations displayed significantly shortened PFS and OS, which may be associated with dCRT resistance. Our data highlighted the prognostic value of aberrant cancer pathways in ESCC patients, which may provide guidance for better chemoradiotherapy management.

Pathway-Based Analysis Revealed the Role of Keap1-Nrf2 Pathway and PI3K-Akt Pathway in Chinese Esophageal Squamous Cell Carcinoma Patients With Definitive Chemoradiotherapy

Esophageal squamous cell carcinoma (ESCC) is the major type of EC in China. Chemoradiotherapy is a standard definitive treatment for early-stage EC and significantly improves local control and overall survival for late-stage patients. However, chemoradiotherapy resistance, which limits therapeutic efficacy and treatment-induced toxicity, is still a leading problem for treatment break. To optimize the selection of ESCC patients for chemoradiotherapy, we retrospectively analyzed the clinical features and genome landscape of a Chinese ESCC cohort of 58 patients. TP53 was the most frequent mutation gene, followed by NOTCH1. Frequently, copy number variants were found in MCL1 (24/58, 41.4%), FGF19 (23/58, 39.7%), CCND1 (22/58, 37.9%), and MYC (20/58, 34.5%). YAP1 and SOX2 amplifications were mutually exclusive in this cohort. Using univariate and multivariate analyses, the YAP1 variant and BRIP1 mutant were identified as adverse factors for OS. Patients with PI3K-Akt pathway alterations displayed longer PFS and OS than patients with an intact PI3K-Akt pathway. On the contrary, two patients with Keap1-Nrf2 pathway alterations displayed significantly shortened PFS and OS, which may be associated with dCRT resistance. Our data highlighted the prognostic value of aberrant cancer pathways in ESCC patients, which may provide guidance for better chemoradiotherapy management.

Erzhi pills ameliorate cognitive dysfunction and alter proteomic hippocampus profiles induced by d-galactose and Aβ1-40 injection in ovariectomized Alzheimer's disease model rats

CONTEXT

Erzhi pills are a classic Chinese medicine prescription, but their effects on Alzheimer's disease (AD) are not clear.

OBJECTIVE

The protective effects of Erzhi pills in AD rats and their potential mechanisms were investigated.

MATERIALS AND METHODS

An AD rat model was established by ovariectomy combined with d-galactose and Aβ_1-40 injection. Rats were randomly divided into five groups: sham-operated, model, oestradiol valerate (0.80 mg/kg), Erzhi pills high-dose (1.50 g/kg), and Erzhi pills low-dose (0.75 g/kg). Learning and memory abilities were evaluated with the Morris water maze test, oestrogen levels with an ELISA kit, and hippocampal neuron morphology and Nissl bodies in the cytoplasm with H&E and Nissl staining. The expression of ERβ, Aβ_1-40, and p-tau⁴⁰⁴ was determined by immunohistochemistry. Nano LC-LTQ-Orbitrap Proteomics determined potential targets and related signalling pathways. Western blotting was used to detect the expression of the related proteins.

RESULTS

Erzhi pills (1.5, 0.75 g/kg) markedly reduced escape latencies on the MWM, increased numbers of platform crossings, numbers of neurons, Nissl bodies, oestrogen levels (100.18, 43.04 pg/mL), and ERβ-positive cells (57.42, 39.83); Aβ_1-40 (18.85, 36.83)- and p-tau⁴⁰⁴ (14.42, 29.71)-positive cells were significantly decreased. Proteomics identified more than 100 differentially expressed proteins involved in 48 signalling pathways, five of which are involved in the PI3K/Akt signalling pathway. Western blotting showed decreased expression of GSK3β and Bad, while Akt, PI3K, 14-3-3, Bcl-xl, and Bcl-2 were upregulated.

DISCUSSION AND CONCLUSION

Erzhi pills may serve as a potential agent for AD therapeutics by improving learning and memory.

DNMT1-induced miR-378a-3p silencing promotes angiogenesis via the NF-κB signaling pathway by targeting TRAF1 in hepatocellular carcinoma

BACKGROUND

Angiogenesis plays an important role in the occurrence, development and metastasis of hepatocellular carcinoma (HCC). According to previous studies, miR-378a participates in tumorigenesis and tumor metastasis, but its exact role in HCC angiogenesis remains poorly understood.

METHODS

qRT-PCR was used to investigate the expression of miR-378a-3p in HCC tissues and cell lines. The effects of miR-378a-3p on HCC in vitro and in vivo were examined by Cell Counting Kit-8 (CCK-8), Transwell, tube formation and Matrigel plug assays, RNA sequencing, bioinformatics, luciferase reporter, immunofluorescence and chromatin immunoprecipitation (ChIP) assays were used to detect the molecular mechanism by which miR-378a-3p inhibits angiogenesis.

RESULTS

We confirmed that miR-378a-3p expression was significantly downregulated and associated with higher microvascular density (MVD) in HCC; miR-378a-3p downregulation indicated a short survival time in HCC patients. miR-378a-3p knockdown led to a significant increase in angiogenesis in vitro and in vivo. We found that miR-378a-3p directly targeted TNF receptor associated factor 1 (TRAF1) to attenuate NF-κB signaling, and then downregulated secreted vascular endothelial growth factor. DNA methyltransferase 1 (DNMT1)-mediated hypermethylation of miR-378a-3p was responsible for downregulating miR-378a-3p. Moreover, a series of investigations indicated that p65 initiated a positive feedback loop that could upregulate DNMT1 to promote hypermethylation of the miR-378a-3p promoter.

CONCLUSION

Our study indicates a novel DNMT1/miR-378a-3p/TRAF1/NF-κB positive feedback loop in HCC cells, which may become a potential therapeutic target for HCC.

The role of emodin on cisplatin resistance reversal of lung adenocarcinoma A549/DDP cell

Exploring drugs that reverse drug resistance and increase the sensitivity of chemotherapy drugs could significantly improve treatment effect of cancer. Our study explored the reversal effect and possible molecular mechanisms of emodin on cisplatin resistance in A549/DDP cells. The IC50 and resistance index of cells were determined by Cell Counting Kit-8 assay. The ability of cell proliferation was evaluated by wound healing assay. Transwell assay was used to detect cell invasion and migration. Apoptosis induction rate was determined by flow cytometry assay and 4',6- diamidino- 2-phenylindole staining. Intracellular concentration was determined by HPLC. Western blot analysis was applied to determine expressions of nuclear factor kappa beta (NF-κB) and its downstream proteins. In this study, we found that the growth inhibitory effect of cisplatin was significantly enhanced by emodin in A549/DDP cells. The combined use of emodin with DDP can effectively promote lung cancer cells apoptosis and inhibit cell migration and invasion. Further investigation indicated that reinforcement effect of emodin and DDP may be associated with inhibition of NF-κB pathway and drug efflux-related proteins such as P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP) and Glutathione S-transferase (GST). The key role of NF-κB was further confirmed by the application of NF-κB inhibitor Ammonium pyrrolidinedithiocarbamate. The intervention of both can significantly increase A549/DDP cell apoptosis and inhibit DDP-induced upregulation of P-gp, MRP and GST. Emodin reverses the cisplatin resistance of tumor cells by down-regulating expression of P-gp, MRP and GST, increasing the intracellular accumulation in A549/DDP cells, and the effect may be associated with the NF-κB pathways.

Interaction of microRNAs with sphingosine kinases, sphingosine-1 phosphate, and sphingosine-1 phosphate receptors in cancer

Sphingosine-1-phosphate (S1P), a pleiotropic lipid mediator, participates in various cellular processes during tumorigenesis, including cell proliferation, survival, drug resistance, metastasis, and angiogenesis. S1P is formed by two sphingosine kinases (SphKs), SphK1 and SphK2. The intracellularly produced S1P is delivered to the extracellular space by ATP-binding cassette (ABC) transporters and spinster homolog 2 (SPNS2), where it binds to five transmembrane G protein-coupled receptors to mediate its oncogenic functions (S1PR1-S1PR5). MicroRNAs (miRNAs) are small non-coding RNAs, 21-25 nucleotides in length, that play numerous crucial roles in cancer, such as tumor initiation, progression, apoptosis, metastasis, and angiogenesis via binding to the 3'-untranslated region (3'-UTR) of the target mRNA. There is growing evidence that various miRNAs modulate tumorigenesis by regulating the expression of SphKs, and S1P receptors. We have reviewed various roles of miRNAs, SphKs, S1P, and S1P receptors (S1PRs) in malignancies and how notable miRNAs like miR-101, miR-125b, miR-128, and miR-506, miR-1246, miR-21, miR-126, miR499a, miR20a-5p, miR-140-5p, miR-224, miR-137, miR-183-5p, miR-194, miR181b, miR136, and miR-675-3p, modulate S1P signaling. These tumorigenesis modulating miRNAs are involved in different cancers including breast, gastric, hepatocellular carcinoma, prostate, colorectal, cervical, ovarian, and lung cancer via cell proliferation, invasion, angiogenesis, apoptosis, metastasis, immune evasion, chemoresistance, and chemosensitivity. Therefore, understanding the interaction of SphKs, S1P, and S1P receptors with miRNAs in human malignancies will lead to better insights for miRNA-based cancer therapy.

The cytokine storms of COVID-19, H1N1 influenza, CRS and MAS compared. Can one sized treatment fit all?

An analysis of published data appertaining to the cytokine storms of COVID-19, H1N1 influenza, cytokine release syndrome (CRS), and macrophage activation syndrome (MAS) reveals many common immunological and biochemical abnormalities. These include evidence of a hyperactive coagulation system with elevated D-dimer and ferritin levels, disseminated intravascular coagulopathy (DIC) and microthrombi coupled with an activated and highly permeable vascular endothelium. Common immune abnormalities include progressive hypercytokinemia with elevated levels of TNF-α, interleukin (IL)-6, and IL-1β, proinflammatory chemokines, activated macrophages and increased levels of nuclear factor kappa beta (NFκB). Inflammasome activation and release of damage associated molecular patterns (DAMPs) is common to COVID-19, H1N1, and MAS but does not appear to be a feature of CRS. Elevated levels of IL-18 are detected in patients with COVID-19 and MAS but have not been reported in patients with H1N1 influenza and CRS. Elevated interferon-γ is common to H1N1, MAS, and CRS but levels of this molecule appear to be depressed in patients with COVID-19. CD4+ T, CD8+ and NK lymphocytes are involved in the pathophysiology of CRS, MAS, and possibly H1N1 but are reduced in number and dysfunctional in COVID-19. Additional elements underpinning the pathophysiology of cytokine storms include Inflammasome activity and DAMPs. Treatment with anakinra may theoretically offer an avenue to positively manipulate the range of biochemical and immune abnormalities reported in COVID-19 and thought to underpin the pathophysiology of cytokine storms beyond those manipulated via the use of, canakinumab, Jak inhibitors or tocilizumab. Thus, despite the relative success of tocilizumab in reducing mortality in COVID-19 patients already on dexamethasone and promising results with Baricitinib, the combination of anakinra in combination with dexamethasone offers the theoretical prospect of further improvements in patient survival. However, there is currently an absence of trial of evidence in favour or contravening this proposition. Accordingly, a large well powered blinded prospective randomised controlled trial (RCT) to test this hypothesis is recommended.

Sphingosine kinase 1 downregulation is required for adaptation to serine deprivation

It has been well-established that cancer cells often display altered metabolic profiles, and recent work has concentrated on how cancer cells adapt to serine removal. Serine can be either taken exogenously or synthesized from glucose, and its regulation forms an important mechanism for nutrient integration. One of the several important metabolic roles for serine is in the generation of bioactive sphingolipids since it is the main substrate for serine palmitoyltransferase, the initial and rate-limiting enzyme in the synthesis of sphingolipids. Previously, serine deprivation has been connected to the action of the tumor suppressor p53, and we have previously published on a role for p53 regulating sphingosine kinase 1 (SK1), an enzyme that phosphorylates sphingosine to form sphingosine-1-phosphate (S1P). SK1 is a key enzyme in sphingolipid synthesis that functions in pro-survival and tumor-promoting pathways and whose expression is also often elevated in cancers. Here we show that SK1 was degraded during serine starvation in a time and dose-dependent manner, which led to sphingosine accumulation. This was independent of effects on p53 but required the action of the proteasome. Furthermore, we show that overexpression of SK1, to compensate for SK1 loss, was detrimental to cell growth under conditions of serine starvation, demonstrating that the suppression of SK1 under these conditions is adaptive. Mitochondrial oxygen consumption decreased in response to SK1 degradation, and this was accompanied by an increase in intracellular reactive oxygen species (ROS). Suppression of ROS with N-acteylcysteine resulted in suppression of the metabolic adaptations and in decreased cell growth under serine deprivation. The effects of SK1 suppression on ROS were mimicked by D-erythro-sphingosine, whereas S1P was ineffective, suggesting that the effects of loss of SK1 were due to the accumulation of its substrate sphingosine. This study reveals a new mechanism for regulating SK1 levels and a link of SK1 to serine starvation as well as mitochondrial function.

The Anti-Non-Small Cell Lung Cancer Cell Activity by a mTOR Kinase Inhibitor PQR620

In non-small-cell lung carcinoma (NSCLC), aberrant activation of mammalian target of rapamycin (mTOR) contributes to tumorigenesis and cancer progression. PQR620 is a novel and highly-potent mTOR kinase inhibitor. We here tested its potential activity in NSCLC cells. In primary human NSCLC cells and established cell lines (A549 and NCI-H1944), PQR620 inhibited cell growth, proliferation, and cell cycle progression, as well as cell migration and invasion, while inducing significant apoptosis activation. PQR620 disrupted assembles of mTOR complex 1 (mTOR-Raptor) and mTOR complex 2 (mTOR-Rictor-Sin1), and blocked Akt, S6K1, and S6 phosphorylations in NSCLC cells. Restoring Akt-mTOR activation by a constitutively-active Akt1 (S473D) only partially inhibited PQR620-induced cytotoxicity in NSCLC cells. PQR620 was yet cytotoxic in Akt1/2-silenced NSCLC cells, supporting the existence of Akt-mTOR-independent mechanisms. Indeed, PQR620 induced sphingosine kinase 1 (SphK1) inhibition, ceramide production and oxidative stress in primary NSCLC cells. In vivo studies demonstrated that daily oral administration of a single dose of PQR620 potently inhibited primary NSCLC xenograft growth in severe combined immune deficient mice. In PQR620-treated xenograft tissues, Akt-mTOR inactivation, apoptosis induction, SphK1 inhibition and oxidative stress were detected. In conclusion, PQR620 exerted potent anti-NSCLC cell activity via mTOR-dependent and -independent mechanisms.

Physiological and pathological functions of sphingolipids in pregnancy

Signaling by the bioactive sphingolipid, sphingosine 1-phosphate (S1P), and its precursors are emerging areas in pregnancy research. S1P and ceramide levels increase towards end of gestation, suggesting a physiological role in parturition. However, high levels of circulating S1P and ceramide are correlated with pregnancy disorders such as preeclampsia, gestational diabetes mellitus and intrauterine growth restriction. Expression of placental and decidual enzymes that metabolize S1P and S1P receptors are also dysregulated during pregnancy complications. In this review, we provide an in-depth examination of the signaling mechanism of S1P and ceramide in various reproductive tissues during gestation. These factors determine implantation and early pregnancy success by modulating corpus luteum function from progesterone production to luteolysis through to apoptosis. We also highlight the role of S1P through receptor signaling in inducing decidualization and angiogenesis in the decidua, as well as regulating extravillous trophoblast migration to anchor the placenta into the uterine wall. Recent advances on the role of the S1P:ceramide rheostat in controlling the fate of villous trophoblasts and the role of S1P as a negative regulator of trophoblast syncytialization to a multinucleated placental barrier are discussed. This review also explores the role of S1P in anti-inflammatory and pro-inflammatory signaling, its role as a vasoconstrictor, and the effects of S1P metabolizing enzymes and receptors in pregnancy.

Long Intergenic Nonprotein Coding RNA 173 Inhibits Tumor Growth and Promotes Apoptosis by Repressing Sphingosine Kinase 1 Protein Expression in Pancreatic Cancer

Pancreatic cancer is a common malignant tumor worldwide. Extensive studies have been conducted on the functional role of long noncoding RNAs in pancreatic cancer. In this study, long intergenic nonprotein coding RNA 173 (LINC00173) was highly expressed in pancreatic cancer tissues. In vitro functional experiments showed that LINC00173 overexpression inhibited the proliferation and invasion of pancreatic cancer cells and promoted cell apoptosis in MIA PaCa-2 and PANC-1 cells. RNA sequencing analysis and Western blot assays demonstrated that LINC00173 reduced the expression of sphingosine kinase 1 (SPHK1) and then inhibited the protein expression of activated phospho-protein kinase B (AKT) and NF-κB. In vivo functional assays also revealed that LINC00173 inhibited the growth of pancreatic cancer xenografts, repressed cell proliferation, promoted cell apoptosis, and inhibited SPHK1 expression. The combined results of this study indicate that LINC00173 inhibits pancreatic cancer progression by repressing SPHK1 expression. Improving LINC00173 may represent a therapeutic strategy for pancreatic cancer in the future.

Targeting the Sphingosine Kinase/Sphingosine-1-Phosphate Signaling Axis in Drug Discovery for Cancer Therapy

Sphingolipid metabolites have emerged as critical players in the regulation of various physiological processes. Ceramide and sphingosine induce cell growth arrest and apoptosis, whereas sphingosine-1-phosphate (S1P) promotes cell proliferation and survival. Here, we present an overview of sphingolipid metabolism and the compartmentalization of various sphingolipid metabolites. In addition, the sphingolipid rheostat, a fine metabolic balance between ceramide and S1P, is discussed. Sphingosine kinase (SphK) catalyzes the synthesis of S1P from sphingosine and modulates several cellular processes and is found to be essentially involved in various pathophysiological conditions. The regulation and biological functions of SphK isoforms are discussed. The functions of S1P, along with its receptors, are further highlighted. The up-regulation of SphK is observed in various cancer types and is also linked to radio- and chemoresistance and poor prognosis in cancer patients. Implications of the SphK/S1P signaling axis in human pathologies and its inhibition are discussed in detail. Overall, this review highlights current findings on the SphK/S1P signaling axis from multiple angles, including their functional role, mechanism of activation, involvement in various human malignancies, and inhibitor molecules that may be used in cancer therapy.

LncRNA PSMG3AS1 promotes proliferation of non-small cell lung cancer cells by sponging miR-613 to upregulate SphK1

PSMG3-AS1 is a characterized oncogenic lncRNA in breast cancer, while its role in other cancers remains unclear. This study was to investigate the role and underlying mechansim of PSMG3-AS1 in non-small cell lung cancer (NSCLC). In this study, we found that PSMG3-AS1 could interact with miR-613. The expression of PSMG3-AS1 was upregulated in NSCLC, while the expression of miR-613 was downregulated in NSCLC. However, PSMG3-AS1 and miR-613 were not significantly correlated with each other. In NSCLC cells, PSMG3-AS1 and miR-613 overexpression failed to regulate the expression of each other. Interestingly, PSMG3-AS1 overexpression led to upregulated SphK1, a downstream target of miR-613. In addition, PSMG3-AS1 overexpression reduced the inhibitory effects of miR-613 on NSCLC cell proliferation. Therefore, PSMG3-AS1 may promote the proliferation of NSCLC cells by sponging miR-613 to upregulate SphK1.

Stigmasterol Simultaneously Induces Apoptosis and Protective Autophagy by Inhibiting Akt/mTOR Pathway in Gastric Cancer Cells

Background

Stigmasterol (SS) has been proven to possess potential anticancer activities in several cancer cell lines, but its molecular mechanism is still unknown. Thus, we investigated whether SS has the capabilities of inducing autophagy and its molecular mechanisms in gastric cancer cells.

Methods

We used CCK8 assay, clone formation assay, and EdU proliferation assay to assess the effects of SS on cell proliferation in SGC-7901 and MGC-803 cells in vitro, and its inhibition on the tumor growth of gastric cancer was observed in vivo. Apoptosis induced by SS was demonstrated using Hoechst and TUNEL staining, annexin V-FITC/PI assay. Immunofluorescence staining is used to detect the formation of autophagosomes triggered by SS. Apoptosis and autophagy related proteins were analyzed by western blot.

Results

The results indicated that SS treatment inhibited cell proliferation in SGC-7901 and MGC-803 cells. Furthermore, SS treatment induced apoptosis and autophagy by blocking Akt/mTOR signaling pathway. The pretreatment with the Akt inhibitor MK-2206 could promote apoptosis and autophagy induced by SS, predicting that Akt/mTOR pathway is involved in SS-induced apoptosis and autophagy. In addition, blockade of autophagy with 3-MA (an inhibitor of autophagy) enhanced SS-induced apoptosis in SGC-7901 and MGC-803 cells, implying that autophagy mediated by SS plays a cytoprotective role against apoptosis. Finally, an in vivo study demonstrated that tumor growth of gastric cancer was suppressed by SS in a xenograft model.

Conclusion

Our findings illustrate for the first time that SS simultaneously induces apoptosis and protective autophagy by inhibiting Akt/mTOR pathway in gastric cancer cells, and SS may become a potential anticancer drug in treating gastric cancer in the future.

Prognostic Impact of Sphingosine Kinase 1 in Nonsmall Cell Lung Cancer

Bioactive sphingolipid is clearly relevant to lung physiology. The relationship of the bioactive sphingolipid pathway to pulmonary disease has been studied in cellular, tissue, and animal model, including lung cancer models. The samples of 53 patients diagnosed with nonsmall cell lung carcinoma (NSCLC) between June 2009 and May 2014 at our hospital were analyzed. Immunohistochemical (IHC) analysis was performed. The degree of immunostaining was reviewed and scored. Using this method of assessment, we evaluated the IHC score of sphingosine kinase 1 (SPHK1), vimentin, E-cadherin, and Ki-67. Both invasive adenocarcinoma cell and squamous cell carcinoma cell were well stained by SPHK1, and fibroblasts were also well stained by SPHK1. Although the IHC score of SPHK1 was not significantly differed between invasive adenocarcinoma and squamous cell carcinoma, the IHC scores of fibroblast, vimentin, and Ki-67 were higher in squamous cell carcinoma than invasive adenocarcinoma. Correlation among IHC scores in each of invasive adenocarcinoma and squamous cell carcinoma was performed. SPHK1 had positive correlation with both fibroblast and Ki-67, and fibroblast and Ki-67 had also positive correlation in invasive adenocarcinoma. On the contrary, SPHK1 had no significant correlation with fibroblast, and had negative correlation with Ki-67 in squamous cell carcinoma. Although there was not significant prognostic difference in SPHK1 score (P = .09), IHC score high group tended to be worse on relapse-free survival. SPHK1 might be prognostic factor in lung-invasive adenocarcinoma and novel target for drug against lung-invasive adenocarcinoma.

Sphingosine Kinase 1 Signaling in Breast Cancer: A Potential Target to Tackle Breast Cancer Stem Cells

Sphingosine kinases (SPHKs) are conserved lipid enzymes that catalyze the formation of sphingosine-1-phosphate (S1P) through ATP-dependent phosphorylation of sphingosine. Two distinct SPHK isoforms, namely SPHK1 and SPHK2, have been identified to date, and the former has been implicated for its oncogenic roles in cancer development and progression. While SPHK1 signaling axis has been extensively studied in non-stem breast cancer cells, recent evidence has emerged to suggest a role of SPHK1 in regulating cancer stem cells (CSCs). With the clinical implications of CSCs in disease relapse and metastasis, it is believed that therapeutic approaches that can eradicate both non-stem cancer cells and CSCs could be a key to cancer cure. In this review, we first explore the oncogenic functions of sphingosine kinase 1 in human cancers and summarize current research findings of SPHK1 signaling with a focus on breast cancer. We also discuss the therapeutic potentials and perspectives of targeting SPHK1 signaling in breast cancer and cancer stem cells. We aim to offer new insights and inspire future studies looking further into the regulatory functions of SPHK1 in CSC-driven tumorigenesis, uncovering novel therapeutic avenues of using SPHK1-targeted therapy in the treatment of CSC-enriched refractory cancers.

The Tumorigenic Effect of Sphingosine Kinase 1 and Its Potential Therapeutic Target

Sphingosine kinase 1 (SPHK1) regulates cell proliferation and survival by converting sphingosine to the signaling mediator sphingosine 1-phosphate (S1P). SPHK1 is widely overexpressed in most cancers, promoting tumor progression and is associated with clinical prognosis. Numerous studies have explored SPHK1 as a promising target for cancer therapy. However, due to insufficient knowledge of SPHK1 oncogenic mechanisms, its inhibitors’ therapeutic potential in preventing and treating cancer still needs further investigation. In this review, we summarized the metabolic balance regulated by the SPHK1/S1P signaling pathway and highlighted the oncogenic mechanisms of SPHK1 via the upregulation of autophagy, proliferation, and survival, migration, angiogenesis and inflammation, and inhibition of apoptosis. Drug candidates targeting SPHK1 were also discussed at the end. This review provides new insights into the oncogenic effect of SPHK1 and sheds light on the future direction for targeting SPHK1 as cancer therapy.

Bioactive sphingolipids: Advancements and contributions from the laboratory of Dr. Lina M. Obeid

Sphingolipids and their synthetic enzymes have emerged as critical mediators in numerous diseases including inflammation, aging, and cancer. One enzyme in particular, sphingosine kinase (SK) and its product sphingosine-1-phosphate (S1P), has been extensively implicated in these processes. SK catalyzes the phosphorylation of sphingosine to S1P and exists as two isoforms, SK1 and SK2. In this review, we will discuss the contributions from the laboratory of Dr. Lina M. Obeid that have defined the roles for several bioactive sphingolipids in signaling and disease with an emphasis on her work defining SK1 in cellular fates and pathobiologies including proliferation, senescence, apoptosis, and inflammation.

Prognostic role of lipid phosphate phosphatases in non-smoker, lung adenocarcinoma patients

Sphingosine-1-phosphate (S1P), a bioactive sphingolipid, plays a crucial role in tumorigenesis. It mediates its function through S1P receptors. A few components of the S1P signaling pathway, such as sphingosine kinase 1 (SphK1) and S1P receptor 1 (S1PR1), have been shown to contribute to lung carcinogenesis. In the present study, using web-based computational tools, we assessed the prognostic roles of eight S1P metabolizing enzymes and five S1P receptors in non-small-cell lung cancer (NSCLC) patients. Except for SPHK1, low expression of S1P metabolizing enzymes was correlated with worse overall survival (OS) in NSCLC patients. Moreover, lower expression of lipid phosphate phosphatase-1 and - 3 (PLPP1 and PLPP3) was significantly associated with worse OS in lung adenocarcinoma (LUAD) and non-smoker NSCLC patients. Furthermore, the UALCAN database analysis showed that mRNA and protein expression of PLPP3 and S1PR1 are significantly down regulated in primary tumors due to hypermethylation of their respective promoters. Expression of PLPP3, S1PR1, and S1PR4 was positively correlated with tumor-infiltrating immune cells in NSCLC patients. These results indicate that S1P signaling genes play a critical prognostic role in LUAD patients. Therefore, this gene signature could be used to predict their prognosis more accurately.

GDC-0349 inhibits non-small cell lung cancer cell growth

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related human mortality with a clear need for new therapeutic intervention. GDC-0349 is a potent and selective ATP-competitive mTOR inhibitor. In A549 cells and primary human NSCLC cells, GDC-0349 inhibited cell growth, proliferation, cell cycle progression, migration and invasion, while inducing significant apoptosis activation. Although GDC-0349 blocked Akt-mTORC1/2 activation in NSCLC cells, it also exerted cytotoxicity in Akt1-knockout A549 cells. Furthermore, restoring Akt-mTOR activation by a constitutively-active Akt1 only partially attenuated GDC-0349-induced A549 cell apoptosis, indicating the existence of Akt-mTOR-independent mechanisms. In NSCLC cells GDC-0349 induced sphingosine kinase 1 (SphK1) inhibition, ceramide accumulation, JNK activation and oxidative injury. Conversely, N-acetylcysteine, the JNK inhibitor and sphingosine 1-phosphate alleviated GDC-0349-induced NSCLC cell apoptosis. In vivo, daily oral administration of GDC-0349 potently inhibited NSCLC xenograft growth in mice. Akt-mTOR in-activation, SphK1 inhibition, JNK activation and oxidative stress were detected in NSCLC xenograft tissues with GDC-0349 administration. In summary, GDC-0349 inhibits NSCLC cell growth via Akt-mTOR-dependent and Akt-mTOR-independent mechanisms.

Small Molecule Destabilizer of β-Catenin and Ras Proteins Antagonizes Growth of K-Ras Mutation-Driven Colorectal Cancers Resistant to EGFR Inhibitors

BACKGROUND

Oncogenic K-Ras mutations in colorectal cancer (CRC) combined with APC mutations worsen CRC prognosis and lower drug effectiveness. Thus, inhibition of both Wnt/β-catenin and Ras-MAPK signaling may be a rational strategy to improve the treatment of this cancer.

OBJECTIVE

To identify a novel compound inhibiting both Wnt/β-catenin and Ras-MAPK signaling in CRC.

METHODS AND PATIENTS

We developed a two-part screening system consisting of analysis of TOP flash reporter cells and then potential toxicity effects on primary neural stem cells (NSCs). We then screened 2000 chemical compounds and tested efficacy of candidates against isogenic colon cancer cells harboring wild-type or mutant K-Ras. We employed immunohistochemistry and immunocytochemistry to determine marker signatures associated with development of disease phenotypes.

RESULTS

We identified CPD0857, a compound that inactivates Wnt/β-catenin signaling and promotes ubiquitin-dependent proteasomal degradation of β-catenin and Ras proteins. CPD0857 effectively decreased proliferation and increased apoptosis of CRC cell lines, and overcame resistance of CRC harboring APC and K-Ras mutations to treatment with an EGFR monoclonal antibody (mAb). Moreover, CPD0857 attenuated invasiveness of highly migratory CRC cells in vitro. Accordingly, xenograft mice treated with CPD0857 showed slower tumor growth and significant decreases in both β-catenin and Ras protein expression.

CONCLUSIONS

CPD0857 may be a potential drug for treating aggressive CRC carrying mutations that aberrantly activate Wnt/β-catenin and Ras-ERK pathways.

PRDX1 is a Tumor Suppressor for Nasopharyngeal Carcinoma by Inhibiting PI3K/AKT/TRAF1 Signaling

Background

Peroxiredoxin 1 (PRDX1) has been identified as a dual regulator of tumorigenesis. However, its expression, clinical significance, and biological function in nasopharyngeal carcinoma (NPC) remain unknown. This study aimed to explore the role and underlying mechanisms of PRDX1 in NPC.

Materials and Methods

The expression of PRDX1 in NPC tissues was evaluated by immunohistochemistry, and the relationships between the expression of PRDX1 and clinical features and prognosis of NPC patients were analyzed. The effects of PRDX1 on NPC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) were examined. A tumor-bearing model of nude mouse was established to verify the function of PRDX1 in vivo.

Results

PRDX1 expression level was negatively associated with recurrence and metastasis of NPC. PRDX1 knockdown promoted NPC cell proliferation, migration, invasion and EMT in vitro, and enhanced tumor growth in vivo, while PRDX1 overexpression had opposite effects. Furthermore, transcriptome analysis showed that PRDX1 inhibited the activation of PI3K/AKT/TRAF1 signaling in NPC cells.

Conclusion

PRDX1 inhibits NPC by inhibiting the activation of PI3K/AKT/TRAF1 signaling. PRDX1 is a tumor suppressor in human NPC and may be a prognostic biomarker for NPC patients.

Discovery of Harmaline as a Potent Inhibitor of Sphingosine Kinase-1: A Chemopreventive Role in Lung Cancer

The sphingosine kinase-1/sphingosine-1-phosphate pathway is linked with the cancer progression and survival of the chemotherapy-challenged cells. Sphingosine kinase-1 (SphK1) has emerged as an attractive drug target, but their inhibitors from natural sources are limited. In this study, we have chosen harmaline, one of the β-carboline alkaloids, and report its mechanism of binding to SphK1 and subsequent inhibition. Molecular docking combined with fluorescence binding studies revealed that harmaline binds to the substrate-binding pocket of SphK1 with an appreciable binding affinity and significantly inhibits the kinase activity of SphK1 with an IC50 value in the micromolar range. The cytotoxic effect of harmaline on non-small-cell lung cancer cells by MTT assay was found to be higher for H1299 compared to A549. Harmaline induces apoptosis in non-small-cell lung carcinoma cells (H1299 and A549), possibly via the intrinsic pathway. Our findings suggest that harmaline could be implicated as a scaffold for designing potent anticancer molecules with SphK1 inhibitory potential.

NF-κB inhibitors in treatment and prevention of lung cancer

Intracellular signalling pathways have provided excellent resource for drug development particularly in the development of cancer therapeutics. A wide variety of malignancies common in human exhibit aberrant NF-κB constitutive expression which results in tumorigenic processes and cancer survival in a variety of solid tumour, including pancreatic cancer, lung, cervical, prostate, breast and gastric carcinoma. Numerous evidences indicate that NF-κB signalling mechanism is mainly involved in the progression of several cancers which may intensify an enhanced knowledge on its role in disease particularly lung tumorigenesis. This has led to tremendous research in designing a variety of NF-κB antagonists with enhanced clinical applications through different approaches the most common being suppression of IκB kinase (IKK) beta activity. Many NF-κB inhibitors for lung cancer are now under clinical trials. Preliminary results of clinical trials for several of these agents include small-molecule inhibitors and monoclonal antibodies. A few combinatorial treatment therapies are currently under investigation in the clinics and have shown promise, particularly NF-κB inhibition associated with lung cancer.

Ziziphora clinopodioides flavonoids based on network pharmacology attenuates atherosclerosis in rats induced by high-fat emulsion combined with vitamin D3 by down-regulating VEGF/AKT/NF-κB signaling pathway

Ziziphora clinopodioides flavonoids (ZCF) is a major bioactive total flavonoids compound isolated from Ziziphora clinopodioides Lam. It has been long used as an anti-atherosclerosis (AS) in clinics. However, anti-AS effects of ZCF have not been fully investigated. The objective of this study is to further investigate the anti-AS activities and mechanisms of ZCF in vivo. The main chemical components, action targets and signal pathways of Ziziphora clinopodioides Lam were predicted and analyzed by network pharmacology technology. The main bioactive components of Ziziphora clinopodioides Lam were identified using high performance liquid chromatography-mass spectrometry (HPLC-MS). In vivo experiments, atherosclerosis in rats induced by high-fat emulsion combined with vitamin D₃ and treated with simvastatin (0.45 mg/kg/d), ZCF (6.25, 12.5, 25 g/kg/d) for 7 weeks. We found that ZCF significantly reduced blood lipid levels (TG, TC, and LDL-C), and decreased lipid deposition in the aorta and atherosclerotic lesion size, inhibited mitochondrial mem- brane potential (MMP2/9/12/13) impairment. Meanwhile, ZCF may down-regulated the levels of VEGF, AKT, NF-κB, ICAM-1 and VCAM-1 proteins, indicating ZCF may play an anti-atherosclerotic role by down-regulating the VEGF/AKT/NF-κB signaling pathway. Results from this study demonstrated that ZCF have an anti-AS ability to lower lipid concentrations and protect endothelial function, antioxidant and anti-inflammatory activity, and suggested that ZCF might be a potential therapeutic drug in the prevention of AS.

Sphingosine Kinase 1 Regulates the Survival of Breast Cancer Stem Cells and Non-stem Breast Cancer Cells by Suppression of STAT1

Cancer stem cells (CSCs) represent rare tumor cell populations capable of self-renewal, differentiation, and tumor initiation and are highly resistant to chemotherapy and radiotherapy. Thus, therapeutic approaches that can effectively target CSCs and tumor cells could be the key to efficient tumor treatment. In this study, we explored the function of SPHK1 in breast CSCs and non-CSCs. We showed that RNAi-mediated knockdown of SPHK1 inhibited cell proliferation and induced apoptosis in both breast CSCs and non-CSCs, while ectopic expression of SPHK1 enhanced breast CSC survival and mammosphere forming efficiency. We identified STAT1 and IFN signaling as key regulatory targets of SPHK1 and demonstrated that an important mechanism by which SPHK1 promotes cancer cell survival is through the suppression of STAT1. We further demonstrated that SPHK1 inhibitors, FTY720 and PF543, synergized with doxorubicin in targeting both breast CSCs and non-CSCs. In conclusion, we provide important evidence that SPHK1 is a key regulator of cell survival and proliferation in breast CSCs and non-CSCs and is an attractive target for the design of future therapies.

Design of Sphingosine Kinases Inhibitors: Challenges and Recent Developments

BACKGROUND

Sphingosine kinases (SphKs) catalyze the phosphorylation of sphingosine to form the bioactive sphingolipid metabolite sphingosine-1-phosphate (S1P). S1P is an important lipid mediator with a wide range of biological functions; it is also involved in a variety of diseases such as inflammatory diseases, Alzheimer's disease and cancer.

METHODS

This review reports the recent advancement in the research of SphKs inhibitors. Our purpose is also to provide a complete overview useful for underlining the features needed to select a specific pharmacological profile.

DISCUSSION

Two distinct mammalian SphK isoforms have been identified, SphK1 and SphK2. These isoforms are encoded by different genes and exhibit distinct subcellular localizations, biochemical properties and functions. SphK1 and SphK2 inhibition can be useful in different pathological conditions.

CONCLUSION

SphK1 and SphK2 have many common features but different and even opposite biological functions. For this reason, several research groups are interested in understanding the therapeutic usefulness of a selective or non-selective inhibitor of SphKs. Moreover, a compensatory mechanism for the two isoforms has been demonstrated, thus leading to the development of dual inhibitors.