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

PI3K/mTOR Inhibitor VS-5584 Alters Expression of WNT Signaling Genes and Induces Apoptosis in Lung Adenocarcinoma Cells: In Vitro and In Silico Insight

Lung cancer (LC) accounts for approximately 25% of all cancer cases, with 80-85% of these being non-small cell lung cancer (NSCLC). VS-5584 is a novel anti-cancer agent that specifically inhibits mTORC1/2 and class I PI3K isoforms. There is cross-talk between the PI3K-Akt-mTOR and WNT signaling pathways that are abnormally activated in NSCLC. In this study, we aimed to evaluate the anti-cancer effects of VS-5584 on A549 lung adenocarcinoma cells and changes in WNT signaling gene expression in vitro, while also correlating differentially expressed genes in silico. The effect of VS-5584 on A549 cell viability was assessed by the MTT assay. Apoptosis and cell cycle profiles were analyzed by flow cytometry, while WNT signaling gene expression was measured by quantitative RT-PCR. Differentially expressed genes (DEGs) in the TCGA LUAD and LUSC datasets were identified using the GEPIA2 platform. VS-5584 treatment induced apoptosis and caused cell cycle arrest at the G0/G1 phase in A549 cells. The mRNA expression levels of WNT signaling genes significantly decreased in treated cells. The expression of some upregulated DEGs in the datasets decreased in A549 cells treated with VS-5584. VS-5584 shows promise as an anti-cancer agent in the treatment of NSCLC by downregulating the expression of WNT signaling genes.

NADH:ubiquinone oxidoreductase core subunit S8 expression and functional significance in non-small cell lung cancer

Hyperfunctional mitochondria provide a growth advantage by supporting the energy-intensive processes essential for non-small cell lung cancer (NSCLC). NADH:ubiquinone oxidoreductase core subunit S8 (NDUFS8) is a key subunit of mitochondrial complex I involved in oxidative phosphorylation (OXPHOS) and cellular energy production. Bioinformatics and local tissue examinations show that NDUFS8 expression is elevated in NSCLC compared to normal lung tissue. Both immortalized and primary human NSCLC cells exhibit higher NDUFS8 levels. Single-cell RNA sequencing confirmed NDUFS8 upregulation in cancerous cells of NSCLC tumor. Silencing NDUFS8 via shRNA or Cas9/sgRNA-mediated knockout (KO) disrupted mitochondrial functions, leading to decreased complex I activity, ATP depletion, mitochondrial depolarization, increased reactive oxygen species (ROS) production, and heightened lipid peroxidation. Furthermore, NDUFS8 silencing/KO triggered apoptosis and significantly reduced Akt-mTOR activation, cell viability, proliferation, and motility in various NSCLC cells. In contrast, ectopic overexpression of NDUFS8 boosted mitochondrial complex I activity and ATP levels, promoting Akt-mTOR activation, and enhancing NSCLC cell proliferation and motility. NDUFS8 also contributes to radioresistance in NSCLC; silencing or KO enhanced ionizing radiation (IR)-induced cytotoxicity, while overexpression mitigated it. Intratumoral injection of NDUFS8 shRNA-expressing adeno-associated virus significantly inhibited growth of primary NSCLC xenografts in nude mice, with observed NDUFS8 silencing, ATP reduction, oxidative damage, proliferation inhibition, Akt-mTOR inactivation and apoptosis in treated tissues. These findings highlight the pivotal pro-tumorigenic role of NDUFS8 in NSCLC.

TIMM23 overexpression drives NSCLC cell growth and survival by enhancing mitochondrial function

Mitochondrial hyperfunction is implicated in promoting non-small cell lung cancer (NSCLC) cell growth. TIMM23 (translocase of inner mitochondrial membrane 23) is a core component of the mitochondrial import machinery, facilitating the translocation of proteins across the inner mitochondrial membrane into the matrix. Its expression and potential functions in NSCLC were tested. Comprehensive bioinformatic analysis revealed a strong correlation between TIMM23 overexpression and adverse clinical outcomes in NSCLC patients. Single-cell RNA sequencing data further corroborated these findings, demonstrating elevated TIMM23 expression within the cancer cells of NSCLC mass. Subsequent experimental validation confirmed significantly increased TIMM23 mRNA and protein levels in locally-treated NSCLC tissues compared to matched normal lung tissues. Moreover, TIMM23 expression was consistently elevated across multiple primary/established NSCLC cells. Silencing or ablation of TIMM23 via shRNA or CRISPR/Cas9 in NSCLC cells resulted in impaired mitochondrial function, characterized by reduced complex I activity, ATP depletion, mitochondrial membrane potential dissipation, oxidative stress, and lipid peroxidation. These mitochondrial perturbations coincided with attenuated cell viability, proliferation, and migratory capacity, and concomitant induction of apoptosis. Conversely, ectopic overexpression of TIMM23 significantly enhanced mitochondrial complex I activity and ATP production, promoting NSCLC cell proliferation and motility. In vivo, intratumoral delivery of a TIMM23 shRNA-expressing adeno-associated virus significantly suppressed the growth of subcutaneous NSCLC xenografts in nude mice. Subsequent analysis of tumor tissues revealed depleted TIMM23 expression, ATP reduction, oxidative damage, proliferative arrest, and apoptotic induction. Collectively, these findings establish TIMM23 as a critical pro-tumorigenic factor in NSCLC, highlighting its potential as a prognostic biomarker and therapeutic target.

Identification of G protein subunit alpha i3 as a promising oncotarget of LUAD

Exploring new oncotargets essential for lung adenocarcinoma (LUAD) cell growth is important. Here the bioinformatical studies revealed that Gαi3 expression is elevated in LUAD tissues and its overexpression correlates with poor survival of the patients. Moreover, overexpression of Gαi3 mRNA and protein was detected in LUAD tissues of patients as well as in primary/immortalized LUAD cells. In both primary and immortalized LUAD cells, genetic silencing (by viral shRNA) or knockout ("KO", through CRISPR/Cas9 method) of Gαi3 potently inhibited LUAD cell proliferation and mobility. The results of caspase-3 activity assay, caspase-9 activity assay, histone DNA ELISA, TUNEL nuclear staining and Annexin V staining showed that inhibition of Gαi3 expression promoted apoptosis. In addition, a significant decrease in mitochondrial membrane potential was found in Gαi3-deficient LUAD cells by JC-1 staining. Overexpression of Gαi3 strengthened the proliferation and migration of LUAD cell. Gene set enrichment analysis revealed that Gαi3 was closely related to PI3k/Akt/mTOR, which we validated experimentally. Akt-S6K phosphorylation was downregulated following Gαi3 silencing or KO, but augmented after Gαi3 overexpression in primary LUAD cells. Restoring Akt-S6K phosphorylation by a S473D constitutively-active mutant Akt1 ameliorated Gαi3 KO-induced LUAD cell proliferation inhibition, migration suppression and apoptosis. In vivo, the growth of subcutaneous LUAD xenografts was largely inhibited after intratumoral injection of Gαi3 shRNA-expressing adeno-associated virus (AAV). Gαi3 downregulation, Akt-mTOR inhibition, proliferation inactivation and apoptosis were detected in the Gαi3 shRNA-treated LUAD xenografts. Together, targeting Gαi3 potently inhibited LUAD cell growth in vitro and in vivo.

The expression and functional role of proline-rich 15 in non-small cell lung cancer

Proline-rich 15 (PRR15) is a protein primarily known for its role in placental development. This study investigates the expression, functional significance, and underlying mechanisms of PRR15 in non-small cell lung cancer (NSCLC). Our findings demonstrate significantly elevated PRR15 expression in NSCLC tissues compared to normal lung parenchyma, with higher expression correlating with adverse clinical outcomes. Single-cell RNA sequencing confirmed PRR15 overexpression within the malignant tumor cell population. PRR15 expression was elevated in NSCLC tissues from locally treated patients and in a panel of primary and established NSCLC cells. PRR15 depletion using shRNA or CRISPR/Cas9-mediated knockout significantly suppressed proliferation and migration, while promoting apoptosis in various NSCLC cells. Conversely, ectopic PRR15 overexpression using a lentiviral construct enhanced cell proliferation and migration. Mechanistic investigations implicated PRR15 in the activation of the Akt-mTOR signaling pathway. Inhibition of PRR15 expression via shRNA or CRISPR/Cas9-mediated knockout resulted in decreased Akt and S6K phosphorylation, while PRR15 overexpression led to augmented Akt-S6K signaling in primary human NSCLC cells. In vivo studies using xenograft models further validated the oncogenic role of PRR15, demonstrating that PRR15 knockdown suppressed tumor growth and attenuated Akt-mTOR activation. These findings collectively highlight the potential of PRR15 as a novel oncogenic driver and therapeutic target in NSCLC.

MTOR maintains endothelial cell integrity to limit lung vascular injury

The functional and structural integrity of the endothelium is essential for vascular homeostasis. Loss of barrier function in quiescent and migratory capacity in proliferative endothelium causes exuberant vascular permeability, a cardinal feature of many inflammatory diseases including acute lung injury (ALI). However, the signals governing these fundamental endothelial cell (EC) functions are poorly understood. Here, we identify mechanistic target of rapamycin (MTOR) as an important link in preserving the barrier integrity and migratory/angiogenic responses in EC and preventing lung vascular injury and mortality in mice. Knockdown of MTOR in EC altered cell morphology, impaired proliferation and migration, and increased endocytosis of cell surface vascular endothelial (VE)-cadherin leading to disrupted barrier function. MTOR-depleted EC also exhibited reduced VE-cadherin and vascular endothelial growth factor receptor-2 (VEGFR2) levels mediated in part by autophagy. Similarly, lungs from mice with EC-specific MTOR deficiency displayed spontaneous vascular leakage marked by decreased VE-cadherin and VEGFR2 levels, indicating that MTOR deficiency in EC is sufficient to disrupt lung vascular integrity and may be a key pathogenic mechanism of ALI. Indeed, MTOR as well as VEGFR2 and VE-cadherin levels were markedly reduced in injured mouse lungs or EC. Importantly, EC-targeted gene transfer of MTOR complementary DNA, either prophylactically or therapeutically, mitigated inflammatory lung injury, and improved lung function and survival in mouse models of ALI. These findings reveal an essential role of MTOR in maintaining EC function, identify loss of endothelial MTOR as a key mechanism of lung vascular injury, and show the therapeutic potential of EC-targeted MTOR expression in combating ALI and mortality in mice.

Exploring the Effect of Gomisin A on Non-Small Cell Lung Cancer With Network Pharmacology, Molecular Docking, In Vitro and In Vivo Assays

Gomisin A is an active ingredient of Schisandra chinensis. Pre-clinical studies suggest Gomisin A has good anti-cancer activities against a variety of cancers, but its mechanism of action in non-small cell lung cancer (NSCLC) is unclear. This study aims to explore the potential mechanism of Gomisin A in treating NSCLC. The SwissTargetPrediction, CTD, HERB and PharmMapper databases were used to collect related targets of Gomisin A. NSCLC-related genes were obtained using the GEO, CTD, DisGeNET, OMIM, GeneCards, NCBI, and PharmGKB databases. The central targets and potential mechanisms of Gomisin A against NSCLC were screened using network pharmacology and molecular docking. Finally, the therapeutic activity of Gomisin A on NSCLC was verified by experiments. A total of 161 potential targets of Gomisin A against NSCLC were identified. TNF, AKT1, STAT3, and IL6 were identified as the central targets of Gomisin A. The binding energy of Gomisin A and the central targets was less than -5 kcal/mol. Gomisin A could inhibit NSCLC cell viability, migration and invasion and induce cell cycle arrest and apoptosis. Gomisin A also inhibited in vivo metastasis of NSCLC cells. In addition, Gomisin A could also reduce the expression level of the central targets and inhibit the PI3K-Akt signaling pathway. In summary, Gomisin A may be a candidate drug for the treatment of NSCLC, and TNF, AKT1, STAT3, and IL6 are potential targets for Gomisin A in NSCLC treatment, and its therapeutic mechanism may be related to the PI3K-Akt signaling pathway.

Epigallocatechin-3-gallate Synergistically Inhibits the Proliferation of Lung Cancer Cells with Gemcitabine by Induction of Apoptosis Mediated by ROS Generation

The present study focused on the formulation, characterization, and evaluation of solid lipid nanoparticles (SLNs) loaded with gemcitabine (GEM) and epigallocatechin-3-gallate (EGCG) for lung cancer treatment. A 2-level, 3-factor factorial design was used to optimize various process parameters in the preparation of SLNs. The average particle size and polydispersity index (PDI) of GEM-EGCG SLNs were found to be 122.8 ± 8.02 and 0.1738 ± 0.02, respectively. Drug loading and release studies indicated a sustained release behavior for GEM-EGCG SLNs, with release kinetics confirmed by the Higuchi model. Cell viability and anticancer activities were assessed using the MTT assay, which determined an IC50 value of 12.5 μg/mL for GEM-EGCG SLNs against A549 cell lines (lung carcinoma epithelial cells). The SLNs were able to internalize into the nuclei of cells, likely due to their small particle size, and were effective in killing cancer cells. Additionally, a study of ROS production-mediated apoptosis of A549 cells was performed through FACS. GEM-EGCG SLNs were found to be stable for 3 months. In vivo studies revealed better drug distribution in the lungs and improved pharmacokinetic profile compared with pure drugs. Overall, the results suggest that combining GEM and EGCG in biocompatible SLNs has resulted in synergistic antitumor potential and improved bioavailability for both drugs, making it a promising anticancer therapeutic regimen against lung cancer.

Pseudolaric acid B suppresses NSCLC progression through the ROS/AMPK/mTOR/autophagy signalling pathway

Pseudolaric acid B (PAB), an acid isolated from the roots of Pseudolarix kaempferi gorden, has shown antitumour effects through multiple mechanisms of action. The objective of this study was to investigate the anticancer effect of PAB on non-small cell lung cancer (NSCLC) and its underlying mechanism. In our experiments, we observed that PAB decreased cell viability, inhibited colony formation, induced cell cycle arrest, impeded scratch healing, and increased apoptosis in H1975 and H1650 cells. Additionally, PAB treatment enhanced the fluorescence intensity of MDC staining in NSCLC cells, upregulated the protein expression of microtubule-associated protein light chain 3 II (LC3 II), and downregulated the expression of sequestosome 1 (SQSTM1/P62). Combined treatment with PAB and chloroquine (CQ) increased the protein expression levels of LC3 II and P62 while decreasing the apoptosis of H1975 and H1650 cells. Moreover, treatment with PAB led to significant mTOR inhibition and AMPK activation. PAB combined with compound C (CC) inhibited autophagy and apoptosis. Furthermore, PAB treatment increased intracellular reactive oxygen species (ROS) levels in NSCLC cells, which correlated with the modulation of the AMPK/mTOR signalling pathway and was associated with autophagy and apoptosis. Finally, we validated the antitumour growth activity and mechanism of PAB in vivo using athymic nude mice bearing H1975 tumour cells. In conclusion, our findings suggest that PAB can induce apoptosis and autophagic cell death in NSCLC through the ROS-triggered AMPK/mTOR signalling pathway, making it a promising candidate for future NSCLC treatment.

Targeting the mitochondrial protein YME1L to inhibit osteosarcoma cell growth in vitro and in vivo

Exploring novel diagnostic and therapeutic biomarkers is extremely important for osteosarcoma. YME1 Like 1 ATPase (YME1L), locating in the mitochondrial inner membrane, is key in regulating mitochondrial plasticity and metabolic activity. Its expression and potential functions in osteosarcoma are studied in the present study. We show that YME1L mRNA and protein expression is significantly elevated in osteosarcoma tissues derived from different human patients. Moreover, its expression is upregulated in various primary and immortalized osteosarcoma cells. The Cancer Genome Atlas database results revealed that YME1L overexpression was correlated with poor overall survival and poor disease-specific survival in sarcoma patients. In primary and immortalized osteosarcoma cells, silencing of YME1L through lentiviral shRNA robustly inhibited cell viability, proliferation, and migration. Moreover, cell cycle arrest and apoptosis were detected in YME1L-silenced osteosarcoma cells. YME1L silencing impaired mitochondrial functions in osteosarcoma cells, causing mitochondrial depolarization, oxidative injury, lipid peroxidation and DNA damage as well as mitochondrial respiratory chain complex I activity inhibition and ATP depletion. Contrarily, forced YME1L overexpression exerted pro-cancerous activity and strengthened primary osteosarcoma cell proliferation and migration. YME1L is important for Akt-S6K activation in osteosarcoma cells. Phosphorylation of Akt and S6K was inhibited after YME1L silencing in primary osteosarcoma cells, but was strengthened with YME1L overexpression. Restoring Akt-mTOR activation by S473D constitutively active Akt1 mitigated YME1L shRNA-induced anti-osteosarcoma cell activity. Lastly, intratumoral injection of YME1L shRNA adeno-associated virus inhibited subcutaneous osteosarcoma xenograft growth in nude mice. YME1L depletion, mitochondrial dysfunction, oxidative injury, Akt-S6K inactivation, and apoptosis were detected in YME1L shRNA-treated osteosarcoma xenografts. Together, overexpressed YME1L promotes osteosarcoma cell growth, possibly by maintaining mitochondrial function and Akt-mTOR activation.

Identification of VRK1 as a Novel Potential Biomarker for Prognosis and Immunotherapy in Hepatocellular Carcinoma

Background

Research has indicated that VRK1 is essential for the tumor cell cycle. However, its prognostic and immunotherapeutic predictive significance has not been documented in hepatocellular carcinoma (HCC).

Methods

The TCGA, ICGC, and GSE14520 datasets were used to investigate VRK1 expression and its predictive significance of survival outcomes. The qRT-PCR and immunohistochemistry (IHC) were used to confirm the findings. The immunotherapeutic response of VRK1 was anticipated by the IMvigor210 cohort. Lastly, the association between immune infiltration, m6A modification, and functional enrichment of differentially expressed genes (DEGs) was investigated in connection to VRK1 expression.

Results

VRK1 expression was markedly elevated on both the mRNA and protein levels in HCC. In HCC patients, a high expression of VRK1 was linked to a poor prognosis. Furthermore, there was a substantial positive correlation seen between increased VRK1 expression and the response rate to anti-PD-L1 immunotherapy. Relationships between VRK1 and m6A-related genes as well as different immune cells were shown by correlation studies. Lastly, enrichment analysis revealed a tight relationship between VRK1 and important biological functions, including DNA replication, cell cycle control, and fatty acid metabolism.

Conclusion

Our research reveals the potential of VRK1 as a novel biomarker for prognosis and immunotherapy response in HCC patients.

RPTOR blockade suppresses brain metastases of NSCLC by interfering the ceramide metabolism via hijacking YY1 binding

BACKGROUND

Ceramide metabolism is crucial in the progress of brain metastasis (BM). However, it remains unexplored whether targeting ceramide metabolism may arrest BM.

METHODS

RNA sequencing was applied to screen different genes in primary and metastatic foci and whole-exome sequencing (WES) to seek crucial abnormal pathway in BM + and BM-patients. Cellular arrays were applied to analyze the permeability of blood-brain barrier (BBB) and the activation or inhibition of pathway. Database and Co-Immunoprecipitation (Co-IP) assay were adopted to verify the protein-protein interaction. Xenograft and zebrafish model were further employed to verify the cellular results.

RESULTS

RNA sequencing and WES reported the involvement of RPTOR and ceramide metabolism in BM progress. RPTOR was significantly upregulated in BM foci and increased the permeability of BBB, while RPTOR deficiency attenuated the cell invasiveness and protected extracellular matrix. Exogenous RPTOR boosted the SPHK2/S1P/STAT3 cascades by binding YY1, in which YY1 bound to the regions of SPHK2 promoter (at -353 ~ -365 nt), further promoting the expression of SPHK2. The latter was rescued by YY1 RNAi. Xenograft and zebrafish model showed that RPTOR blockade suppressed BM of non-small cell lung cancer (NSCLC) and impaired the SPHK2/S1P/STAT3 pathway.

CONCLUSION

RPTOR is a key driver gene in the brain metastasis of lung cancer, which signifies that RPTOR blockade may serve as a promising therapeutic candidate for clinical application.

From carcinogenesis to therapeutic avenues: lncRNAs and mTOR crosstalk in lung cancer

Long non-coding RNAs (lncRNAs) have been demonstrated to have a crucial function in the modulation of the activity of genes, impacting a variety of homeostatic processes involving growth, survival, movement, and genomic consistency. Certain lncRNAs' aberrant expression has been linked to carcinogenesis, tumor growth, and therapeutic resistance. They are beneficial for the management of malignancies since they can function as cancer-causing or cancer-suppressing genes and behave as screening or prognosis indicators. The modulation of the tumor microenvironment, metabolic modification, and spread have all been linked to lncRNAs in lung cancer. Recent research has indicated that lncRNAs may interact with various mTOR signalling systems to control expression in lung cancer. Furthermore, the route can affect how lncRNAs are expressed. Emphasizing the function of lncRNAs as crucial participants in the mTOR pathway, the current review intends to examine the interactions between the mTOR cascade and the advancement of lung cancer. The article will shed light on the roles and processes of a few lncRNAs associated with the development of lung cancer, as well as their therapeutic prospects.

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.

Implication of mTOR Signaling in NSCLC: Mechanisms and Therapeutic Perspectives

Mechanistic target of the rapamycin (mTOR) signaling pathway represents a central cellular kinase that controls cell survival and metabolism. Increased mTOR activation, along with upregulation of respective upstream and downstream signaling components, have been established as oncogenic features in cancer cells in various tumor types. Nevertheless, mTOR pathway therapeutic targeting has been proven to be quite challenging in various clinical settings. Non-small cell lung cancer (NSCLC) is a frequent type of solid tumor in both genders, where aberrant regulation of the mTOR pathway contributes to the development of oncogenesis, apoptosis resistance, angiogenesis, cancer progression, and metastasis. In this context, the outcome of mTOR pathway targeting in clinical trials still demonstrates unsatisfactory results. Herewith, we discuss recent findings regarding the mechanisms and therapeutic targeting of mTOR signaling networks in NSCLC, as well as future perspectives for the efficient application of treatments against mTOR and related protein molecules.

HOXC13-driven TIMM13 overexpression promotes osteosarcoma cell growth

TIMM13 (translocase of inner mitochondrial membrane 13) located at the mitochondrial intermembrane space is vital for the integrity and function of mitochondria. We found that the mitochondrial protein TIMM13 is upregulated in human OS tissues and cells. In patient-derived primary OS cells and established cell lines, TIMM13 shRNA or knockout provoked mitochondrial dysfunction, causing mitochondrial depolarization, reactive oxygen species production, and oxidative injury, as well as lipid peroxidation, DNA damage, and ATP depletion. Moreover, TIMM13 depletion provoked OS cell apoptosis and inhibited cell proliferation and migration. Conversely, ectopic TIMM13 overexpression increased ATP contents, enhancing OS cell proliferation and migration. Moreover, we discovered that Akt-mTOR activation was inhibited with TIMM13 depletion in primary OS cells. Further studies revealed that HOXC13 (Homeobox C13)-dependent TIMM13 transcription was significantly increased in OS tissues and cells. Whereas TIMM13 transcription and expression were decreased following HOXC13 silencing in primary OS cells. In vivo, TIMM13 KO potently inhibited OS xenograft growth in the proximal tibia of nude mice. TIMM13 KO also induced Akt-mTOR inactivation, ATP depletion, oxidative injury, and apoptosis in the in situ OS tumors. Together, upregulation of the mitochondrial protein TIMM13 is important for OS cell growth, representing a novel and promising therapeutic target.

mTOR Inhibition Is Effective against Growth, Survival and Migration, but Not against Microglia Activation in Preclinical Glioma Models

Initially introduced in therapy as immunosuppressants, the selective inhibitors of mTORC1 have been approved for the treatment of solid tumors. Novel non-selective inhibitors of mTOR are currently under preclinical and clinical developments in oncology, attempting to overcome some limitations associated with selective inhibitors, such as the development of tumor resistance. Looking at the possible clinical exploitation in the treatment of glioblastoma multiforme, in this study we used the human glioblastoma cell lines U87MG, T98G and microglia (CHME-5) to compare the effects of a non-selective mTOR inhibitor, sapanisertib, with those of rapamycin in a large array of experimental paradigms, including (i) the expression of factors involved in the mTOR signaling cascade, (ii) cell viability and mortality, (iii) cell migration and autophagy, and (iv) the profile of activation in tumor-associated microglia. We could distinguish between effects of the two compounds that were overlapping or similar, although with differences in potency and or/time-course, and effects that were diverging or even opposite. Among the latter, especially relevant is the difference in the profile of microglia activation, with rapamycin being an overall inhibitor of microglia activation, whereas sapanisertib was found to induce an M2-profile, which is usually associated with poor clinical outcomes.

SLC5A3 is important for cervical cancer cell growth

Novel molecular targets for cervical cancer must be identified. This study examined the role of SLC5A3, a myo-inositol transporter, in the pathogenesis of cervical cancer. Through boinformatics analysis, we showed that the SLC5A3 mRNA levels were upregulated in cervical cancer tissues. The upregulated SLC5A3 mRNA levels were negatively correlated with survival and progression-free interval. Genes co-expressed with SLC5A3 were enriched in multiple signaling cascades involved in cancer progression. In primary/established cervical cancer cells, SLC5A3 shRNA/knockout (KO) exerted growth-inhibitory effects and promoted cell death/apoptosis. Furthermore, SLC5A3 knockdown or KO downregulated myo-inositol levels, induced oxidative injury, and decreased Akt-mTOR activation in cervical cancer cells. In contrast, supplementation of myo-inositol or n-acetyl-L-cysteine or transduction of a constitutively active Akt1 construct mitigated SLC5A3 KO-induced cytotoxicity in cervical cancer cells. Lentiviral SLC5A3 overexpression construct transduction upregulated the cellular myo-inositol level and promoted Akt-mTOR activation, enhancing cervical cancer cell proliferation and migration. The binding of TonEBP to the SLC5A3 promoter was upregulated in cervical cancer. In vivo studies showed that intratumoral injection of SLC5A3 shRNA-expressing virus arrested cervical cancer xenograft growth in mice. SLC5A3 KO also inhibited pCCa-1 cervical cancer xenograft growth. The SLC5A3-depleted xenograft tissues exhibited myo-inositol downregulation, Akt-mTOR inactivation, and oxidative injury. Transduction of sh-TonEBP AAV construct downregulated SLC5A3 expression and inhibited pCCa-1 cervical cancer xenograft growth. Together, overexpressed SLC5A3 promotes growth of cervical cancer cells, representing as a novel therapeutic oncotarget for the devastating disease.

The mitochondrial protein YME1 Like 1 is important for non-small cell lung cancer cell growth

The expression and biological function of the mitochondrial inner membrane protease YME1L (YME1 Like 1 ATPase) in NSCLC are tested here. Bioinformatical analyses and results from local human tissues show that YME1L expression is elevated in NSCLC tissues. YME1L upregulation was observed in primary and immortalized NSCLC cells. In NSCLC cells, shRNA-mediated silence of YME1L or dCas9/sgRNA-induced knockout (KO) of YME1L robustly suppressed cell growth and migration, and provoking apoptosis. YME1L shRNA/KO resulted in mitochondrial dysfunctions in NSCLC cells, leading to mitochondrial depolarization, ROS accumulation and ATP depletion. Conversely, ectopic YME1L overexpression augmented NSCLC cell proliferation and motility. Akt-S6K1 phosphorylation was reduced after YME1L shRNA/KO in primary NSCLC cells, but augmented after YME1L overexpression. Importantly, YME1L KO-caused anti-NSCLC cell activity was attenuated by a constitutively-activate Akt1 (S473D) construct. In vivo, subcutaneous NSCLC xenograft growth was remarkably slowed following intratumoral YME1L shRNA AAV injection in nude mice. YME1L knockdown, Akt-mTOR inactivation and ATP reduction were detected in YME1L-silenced NSCLC xenografts. Taken together, overexpressed YME1L in NSCLC exerts pro-tumorigenic function.

Investigation of morpholine isosters for the development of a potent, selective and metabolically stable mTOR kinase inhibitor

Upregulation of mechanistic target of rapamycin (mTOR) signaling drives various types of cancers and neurological diseases. Rapamycin and its analogues (rapalogs) are first generation mTOR inhibitors, and selectively block mTOR complex 1 (TORC1) by an allosteric mechanism. In contrast, second generation ATP-binding site inhibitors of mTOR kinase (TORKi) target both TORC1 and TORC2. Here, we explore 3,6-dihydro-2H-pyran (DHP) and tetrahydro-2H-pyran (THP) as isosteres of the morpholine moiety to unlock a novel chemical space for TORKi generation. A library of DHP- and THP-substituted triazines was prepared, and molecular modelling provided a rational for a structure activity relationship study. Finally, compound 11b [5-(4-(3-oxa-8-azabicyclo[3.2.1]octan-8-yl)-6-(tetrahydro-2H-pyran-4-yl)-1,3,5-triazin-2-yl)-4-(difluoromethyl)pyridin-2-amine] was selected due its potency and selectivity for mTOR kinase over the structurally related class I phosphoinositide 3-kinases (PI3Ks) isoforms. 11b displayed high metabolic stability towards CYP1A1 degradation, which is of advantage in drug development. After oral administration to male Sprague Dawley rats, 11b reached high concentrations both in plasma and brain, revealing an excellent oral bioavailability. In a metabolic stability assay using human hepatocytes, 11b was more stable than PQR620, the first-in-class brain penetrant TORKi. Compound 11b also displayed dose-dependent anti-proliferative activity in splenic marginal zone lymphoma (SMZL) cell lines as single agent and when combined with BCL2 inhibition (venetoclax). Our results identify the THP-substituted triazine core as a novel scaffold for the development of metabolically stable TORKi for the treatment of chronic diseases and cancers driven by mTOR deregulation and requiring drug distribution also to the central nervous system.

ADCK1 is a potential therapeutic target of osteosarcoma

We here showed that ADCK1 (AarF domain-containing kinase 1), a mitochondrial protein, is upregulated in human osteosarcoma (OS) tissues and OS cells. In primary and established OS cells, ADCK1 shRNA or CRISPR/Cas9-induced ADCK1 knockout (KO) remarkably inhibited cell viability, proliferation and migration, and provoked apoptosis activation. Conversely, ectopic ADCK1 overexpression exerted pro-cancerous activity by promoting OS cell proliferation and migration. ADCK1 depletion disrupted mitochondrial functions in OS cells and induced mitochondrial membrane potential reduction, ATP depletion, reactive oxygen species production. Significantly, ADCK1 silencing augmented doxorubicin-induced apoptosis in primary OS cells. mTOR activation is important for ADCK1 expression in OS cells. The mTOR inhibitors, rapamycin and AZD2014, as well as mTOR shRNA, potently decreased ADCK1 expression in primary OS cells. In nude mice, the growth of subcutaneous pOS-1 xenografts was largely inhibited when bearing ADCK1 shRNA or ADCK1 KO construct. Moreover, ADCK1 KO largely inhibited pOS-1 xenograft in situ growth in proximal tibia of nude mice. ADCK1 depletion, apoptosis activation and ATP reduction were detected in pOS-1 xenografts bearing ADCK1 shRNA or ADCK1 KO construct. Together, the mitochondrial protein ADCK1 is required for OS cell growth and is a novel therapeutic target of OS.

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.

Interleukin 7 inhibit autophagy via P53 regulated AMPK/mTOR signaling pathway in non-small cell lung cancer

Interleukin 7 (IL-7) has been demonstrated regulating lymphangiogenesis, apoptosis, and proliferation. Whether IL-7 induce or inhibit autophagy in non-small cell lung cancer (NSCLC) are unknown. In this study, Western blot was used to detect cytoplasmic and nuclear protein of p53, total protein of AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) and Light chain 3 (LC3). Quantitative Real-Time PCR (qRT-PCR) was used to detect p53 mRNA level after treated with IL-7. Then using transmission electron microscopy to observe the morphological change of autophagosome. 123 cases of NSCLC were collected for survival analysis, immunohistochemistry staining and cox regression multivariate analysis. We find that IL-7 induce the p53 translocation from nucleus to cytoplasm, then IL-7 down-regulate phosphorylation of AMPK and up-regulate phosphorylation of mTOR. The expression of AMPK and p53 were associated with IL-7/IL-7R and mTOR expression. Clinically, AMPK and p53 were well correlated with stage and survival of lung cancer patients. IL-7R, mTOR and tumor stage were the strongest predictors of survival. In conclusion, IL-7 inhibit autophagy in NSCLC via P53 regulated AMPK/mTOR signaling pathway. AMPK and p53 are correlated with patients’ survival. IL-7R, mTOR and tumor stage are the strongest predictor of survival.

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.

The sodium/myo-inositol co-transporter SLC5A3 promotes non-small cell lung cancer cell growth

Identification of novel molecular signaling targets for non-small cell lung cancer (NSCLC) is important. The present study examined expression, functions and possible underlying mechanisms of the sodium/myo-inositol co-transporter SLC5A3 in NSCLC. The Cancer Genome Atlas (TCGA) database and local NSCLC tissue results demonstrated that SLC5A3 expression in NSCLC tissues (including patient-derived primary NSCLC cells) was significantly higher than that in normal lung tissues and lung epithelial cells. In primary NSCLC cells and immortalized lines, SLC5A3 depletion, using small hairpin RNA (shRNA) and CRSIRP/Cas9 methods, robustly impeded cell proliferation and migration, simultaneously provoking cell cycle arrest and apoptosis. Conversely, ectopic overexpression of SLC5A3 further enhanced proliferation and migration in primary NSCLC cells. The intracellular myo-inositol contents and Akt-mTOR activation were largely inhibited by SLC5A3 silencing or knockout (KO), but were augmented following SLC5A3 overexpression in primary NSCLC cells. Significantly, SLC5A3 KO-induced anti-NSCLC cell activity was largely ameliorated by exogenously adding myo-inositol or by a constitutively-active Akt construct. By employing the patient-derived xenograft (PDX) model, we found that the growth of subcutaneous NSCLC xenografts in nude mice was largely inhibited by intratumoral injection SLC5A3 shRNA adeno-associated virus (AAV). SLC5A3 silencing, myo-inositol depletion, Akt-mTOR inactivation and apoptosis induction were detected in SLC5A3 shRNA virus-injected NSCLC xenograft tissues. Together, elevated SLC5A3 promotes NSCLC cell growth possibly by maintaining myo-inositol contents and promoting Akt-mTOR activation.

An mTOR and DNA-PK dual inhibitor CC-115 hinders non-small cell lung cancer cell growth

Molecularly-targeted agents are still urgently needed for better non-small cell lung cancer (NSCLC) therapy. CC-115 is a potent DNA-dependent protein kinase (DNA-PK) and mammalian target of rapamycin (mTOR) dual blocker. We evaluated its activity in different human NSCLC cells. In various primary human NSCLC cells and A549 cells, CC-115 potently inhibited viability, cell proliferation, cell cycle progression, and hindered cell migration/invasion. Apoptosis was provoked in CC-115-stimulated NSCLC cells. The dual inhibitor, however, was unable to induce significant cytotoxic and pro-apoptotic activity in the lung epithelial cells. In primary NSCLC cells, CC-115 blocked activation of mTORC1/2 and DNA-PK. Yet, CC-115-induced primary NSCLC cell death was more potent than combined inhibition of DNA-PK plus mTOR. Further studies found that CC-115 provoked robust oxidative injury in primary NSCLC cells, which appeared independent of mTOR-DNA-PK dual blockage. In vivo studies showed that CC-115 oral administration in nude mice remarkably suppressed primary NSCLC cell xenograft growth. In CC-115-treated NSCLC xenograft tissues, mTOR-DNA-PK dual inhibition and oxidative injury were detected. Together, CC-115 potently inhibits NSCLC cell growth.

The functional roles of the circRNA/Wnt axis in cancer

CircRNAs, covalently closed noncoding RNAs, are widely expressed in a wide range of species ranging from viruses to plants to mammals. CircRNAs were enriched in the Wnt pathway. Aberrant Wnt pathway activation is involved in the development of various types of cancers. Accumulating evidence indicates that the circRNA/Wnt axis modulates the expression of cancer-associated genes and then regulates cancer progression. Wnt pathway-related circRNA expression is obviously associated with many clinical characteristics. CircRNAs could regulate cell biological functions by interacting with the Wnt pathway. Moreover, Wnt pathway-related circRNAs are promising potential biomarkers for cancer diagnosis, prognosis evaluation, and treatment. In our review, we summarized the recent research progress on the role and clinical application of Wnt pathway-related circRNAs in tumorigenesis and progression.