A FASN-TGF-β1-FASN regulatory loop contributes to high EMT/metastatic potential of cisplatin-resistant non-small cell lung cancer

Targeting Dysregulated Lipid Metabolism in Cancer with Pharmacological Inhibitors

Metabolic plasticity is recognised as a hallmark of cancer cells, enabling adaptation to microenvironmental changes throughout tumour progression. A dysregulated lipid metabolism plays a pivotal role in promoting oncogenesis. Oncogenic signalling pathways, such as PI3K/AKT/mTOR, JAK/STAT, Hippo, and NF-kB, intersect with the lipid metabolism to drive tumour progression. Furthermore, altered lipid signalling in the tumour microenvironment contributes to immune dysfunction, exacerbating oncogenesis. This review examines the role of lipid metabolism in tumour initiation, invasion, metastasis, and cancer stem cell maintenance. We highlight cybernetic networks in lipid metabolism to uncover avenues for cancer diagnostics, prognostics, and therapeutics.

Therapeutic Approaches of Dual-targeted Nanomedicines for Tumor Multidrug Resistance

Currently, the main cause of cancer chemotherapy failure is multi-drug resistance (MDR), which involves a variety of complex mechanisms. Compared with traditional small-molecule chemotherapy, targeted nanomedicines offer promising alternative strategies as an emerging form of therapy, especially active targeted nanomedicines. However, although single-targeted nanomedicines have made some progress in tumor therapy, the complexity of tumor microenvironment and tumor heterogeneity limits their efficacy. Dual-targeted nanomedicines can simultaneously target two tumor-specific factors that cause tumor MDR, which have the potential in overcoming tumor MDR superior to single-targeted nanomedicines by further enhancing cell uptake and cytotoxicity in new forms, as well as the effectiveness of tumor-targeted delivery. This review discusses tumor MDR mechanisms and the latest achievements applied to dual-targeted nanomedicines in tumor MDR.

A positive feedback loop between ZEB2 and ACSL4 regulates lipid metabolism to promote breast cancer metastasis

Lipid metabolism plays a critical role in cancer metastasis. However, the mechanisms through which metastatic genes regulate lipid metabolism remain unclear. Here, we describe a new oncogenic-metabolic feedback loop between the epithelial-mesenchymal transition transcription factor ZEB2 and the key lipid enzyme ACSL4 (long-chain acyl-CoA synthetase 4), resulting in enhanced cellular lipid storage and fatty acid oxidation (FAO) to drive breast cancer metastasis. Functionally, depletion of ZEB2 or ACSL4 significantly reduced lipid droplets (LDs) abundance and cell migration. ACSL4 overexpression rescued the invasive capabilities of the ZEB2 knockdown cells, suggesting that ACSL4 is crucial for ZEB2-mediated metastasis. Mechanistically, ZEB2-activated ACSL4 expression by directly binding to the ACSL4 promoter. ACSL4 binds to and stabilizes ZEB2 by reducing ZEB2 ubiquitination. Notably, ACSL4 not only promotes the intracellular lipogenesis and LDs accumulation but also enhances FAO and adenosine triphosphate production by upregulating the FAO rate-limiting enzyme CPT1A (carnitine palmitoyltransferase 1 isoform A). Finally, we demonstrated that ACSL4 knockdown significantly reduced metastatic lung nodes in vivo. In conclusion, we reveal a novel positive regulatory loop between ZEB2 and ACSL4, which promotes LDs storage to meet the energy needs of breast cancer metastasis, and identify the ZEB2-ACSL4 signaling axis as an attractive therapeutic target for overcoming breast cancer metastasis.

Stromal-Modulated Epithelial-to-Mesenchymal Transition in Cancer Cells

The ability of cancer cells to detach from the primary site and metastasize is the main cause of cancer- related death among all cancer types. Epithelial-to-mesenchymal transition (EMT) is the first event of the metastatic cascade, resulting in the loss of cell-cell adhesion and the acquisition of motile and stem-like phenotypes. A critical modulator of EMT in cancer cells is the stromal tumor microenvironment (TME), which can promote the acquisition of a mesenchymal phenotype through direct interaction with cancer cells or changes to the broader microenvironment. In this review, we will explore the role of stromal cells in modulating cancer cell EMT, with particular emphasis on the function of mesenchymal stromal/stem cells (MSCs) through the activation of EMT-inducing pathways, extra cellular matrix (ECM) remodeling, immune cell alteration, and metabolic rewiring.

The epithelial-mesenchymal plasticity landscape: principles of design and mechanisms of regulation

Epithelial-mesenchymal plasticity (EMP) enables cells to interconvert between several states across the epithelial-mesenchymal landscape, thereby acquiring hybrid epithelial/mesenchymal phenotypic features. This plasticity is crucial for embryonic development and wound healing, but also underlies the acquisition of several malignant traits during cancer progression. Recent research using systems biology and single-cell profiling methods has provided novel insights into the main forces that shape EMP, which include the microenvironment, lineage specification and cell identity, and the genome. Additionally, key roles have emerged for hysteresis (cell memory) and cellular noise, which can drive stochastic transitions between cell states. Here, we review these forces and the distinct but interwoven layers of regulatory control that stabilize EMP states or facilitate epithelial-mesenchymal transitions (EMTs) and discuss the therapeutic potential of manipulating the EMP landscape.

Effects of Lipid Metabolism-Related Genes PTGIS and HRASLS on Phenotype, Prognosis, and Tumor Immunity in Lung Squamous Cell Carcinoma

Background

Lipid metabolism reprogramming played an important role in cancer occurrence, development, and immune regulation. The aim of this study was to identify and validate lipid metabolism-related genes (LMRGs) associated with the phenotype, prognosis, and immunological characteristics of lung squamous cell carcinoma (LUSC).

Methods

In the TCGA cohort, bioinformatics and survival analysis were used to identify lipid metabolism-related differentially expressed genes (DEGs) associated with the prognosis of LUSC. PTGIS/HRASLS knockdown and overexpression effects on the LUSC phenotype were analyzed in vitro experiments. Based on the expression distribution of PTGIS/HRASLS, LUSC patients were divided into two clusters by consensus clustering. Clinical information, prognosis, immune infiltration, expression of immune checkpoints, and tumor mutation burden (TMB) level were compared between the TCGA and GSE4573 cohorts. The genes related to clustering and tumor immunity were screened by weighted gene coexpression network analysis (WGCNA), and the target module genes were analyzed by functional enrichment analysis, protein-protein interaction (PPI) analysis, and immune correlation analysis.

Results

191 lipid metabolism-related DEGs were identified, of which 5 genes were independent prognostic genes of LUSC. PTGIS/HRASLS were most closely related to LUSC prognosis and immunity. RT-qPCR, western blot (WB) analysis, and immunohistochemistry (IHC) showed that the expression of PTGIS was low in LUSC, while HRASLS was high. Functionally, PTGIS promoted LUSC proliferation, migration, and invasion, while HRASLS inhibited LUSC proliferation, migration, and invasion. The two clusters' expression and distribution of PTGIS/HRASLS had the opposite trend. Cluster 1 was associated with lower pathological staging (pT, pN, and pTNM stages), better prognosis, stronger immune infiltration, higher expression of immune checkpoints, and higher TMB level than cluster 2. WGCNA found that 28 genes including CD4 and IL10RA were related to the expression of PTGIS/HRASLS and tumor immune infiltration. PTGIS/HRASLS in the GSE4573 cohort had the same effect on LUSC prognosis and tumor immunity as the TCGA cohort.

Conclusions

PTGIS and HRASLS can be used as new therapeutic targets for LUSC as well as biomarkers for prognosis and tumor immunity, which has positive significance for guiding the immunotherapy of LUSC.

WY-14643 attenuates lipid deposition via activation of the PPARα/CPT1A axis by targeting Gly335 to inhibit cell proliferation and migration in ccRCC

Background

Histologically, cytoplasmic deposits of lipids and glycogen are common in clear cell renal cell carcinoma (ccRCC). Owing to the significance of lipid deposition in ccRCC, numerous trials targeting lipid metabolism have shown certain therapeutic potential. The agonism of peroxisome proliferator-activated receptor-α (PPARα) via ligands, including WY-14,643, has been considered a promising intervention for cancers.

Methods

First, the effects of WY-14,643 on malignant behaviors were investigated in ccRCC in vitro. After RNA sequencing, the changes in lipid metabolism, especially neutral lipids and glycerol, were further evaluated. Finally, the underlying mechanisms were revealed.

Results

Phenotypically, the proliferation and migration of ccRCC cells treated with WY-14,643 were significantly inhibited in vitro. A theoretical functional mechanism was proposed in ccRCC: WY-14,643 mediates lipid consumption by recognizing carnitine palmitoyltransferase 1 A (CPT1A). Activation of PPARα using WY-14,643 reduces lipid deposition by increasing the CPT1A level, which also suppresses the NF-κB signaling pathway. Spatially, WY-14,643 binds and activates PPARα by targeting Gly335.

Conclusion

Overall, WY-14,643 suppresses the biological behaviors of ccRCC in terms of cell proliferation, migration, and cell cycle arrest. Furthermore, its anticancer properties are mediated by the inhibition of lipid accumulation, at least in part, through the PPARα/CPT1A axis by targeting Gly335, as part of the process, NF-κB signaling is also suppressed. Pharmacological activation of PPARα might offer a new treatment option for ccRCC.

Cerulenin suppresses ErbB2-overexpressing breast cancer by targeting ErbB2/PKM2 pathway

Cerulenin is a fungal metabolite and a specific inhibitor of fatty acid synthase (FASN), which has shown a potential anticancer activity. 20-25% of breast cancer patients with ErbB2-overexpressing develop resistance to treatment. Therefore, it is urgent to find an effective new target for the treatment of ErbB2-overexpressing breast cancer. Our previous study found that cerulenin inhibits the glycolysis and migration of SK-BR-3 cells, but the effect of cerulenin on other malignant phenotypes of breast cancer is still unknown. Furthermore, the mechanism by which cerulenin displays its inhibitory effects is not fully understood. In this study, we systematically investigate the inhibitory effects of cerulenin on proliferation, migration, invasion and glycolysis of ErbB2-overexpressing breast cancer cells and its molecular mechanism. We found that cerulenin obviously suppresses the proliferation, migration, invasion as well as glycolysis. Through bioinformatic analyses, we found that PKM2 might be a target of cerulenin. In addition, ErbB2 and its signaling pathway upregulated PKM2 protein levels. Furthermore, we demonstrated that cerulenin downregulated the protein levels of ErbB2, PKM2 and EMT markers (MMP9, MMP2 and Snail2) in a dose- and time-dependent manner. Finally, the inhibitory of cerulenin on colony formation, migration, invasion and glycolysis, as well as protein levels of EMT markers were rescued by replenishing with PKM2. These findings illustrated that cerulenin inhibits proliferation, migration, invasion and glycolysis by targeting ErbB2/PKM2 pathway in ErbB2-overexpressing breast cancer cells.

Rerouting the drug response: Overcoming metabolic adaptation in KRAS-mutant cancers

Mutations in guanosine triphosphatase KRAS are common in lung, colorectal, and pancreatic cancers. The constitutive activity of mutant KRAS and its downstream signaling pathways induces metabolic rewiring in tumor cells that can promote resistance to existing therapeutics. In this review, we discuss the metabolic pathways that are altered in response to treatment and those that can, in turn, alter treatment efficacy, as well as the role of metabolism in the tumor microenvironment (TME) in dictating the therapeutic response in KRAS-driven cancers. We highlight metabolic targets that may provide clinical opportunities to overcome therapeutic resistance and improve survival in patients with these aggressive cancers.

TGF-β signaling in the tumor metabolic microenvironment and targeted therapies

Transforming growth factor-β (TGF-β) signaling has a paradoxical role in cancer progression, and it acts as a tumor suppressor in the early stages but a tumor promoter in the late stages of cancer. Once cancer cells are generated, TGF-β signaling is responsible for the orchestration of the immunosuppressive tumor microenvironment (TME) and supports cancer growth, invasion, metastasis, recurrence, and therapy resistance. These progressive behaviors are driven by an “engine” of the metabolic reprogramming in cancer. Recent studies have revealed that TGF-β signaling regulates cancer metabolic reprogramming and is a metabolic driver in the tumor metabolic microenvironment (TMME). Intriguingly, TGF-β ligands act as an “endocrine” cytokine and influence host metabolism. Therefore, having insight into the role of TGF-β signaling in the TMME is instrumental for acknowledging its wide range of effects and designing new cancer treatment strategies. Herein, we try to illustrate the concise definition of TMME based on the published literature. Then, we review the metabolic reprogramming in the TMME and elaborate on the contribution of TGF-β to metabolic rewiring at the cellular (intracellular), tissular (intercellular), and organismal (cancer-host) levels. Furthermore, we propose three potential applications of targeting TGF-β-dependent mechanism reprogramming, paving the way for TGF-β-related antitumor therapy from the perspective of metabolism.

Identification and validation of an immune signature associated with EMT and metabolic reprogramming for predicting prognosis and drug response in bladder cancer

Background

Epithelial-mesenchymal transition (EMT), one leading reason of the dismal prognosis of bladder cancer (BLCA), is closely associated with tumor invasion and metastasis. We aimed to develop a novel immune−related gene signature based on different EMT and metabolic status to predict the prognosis of BLCA.

Methods

Gene expression and clinical data were obtained from TCGA and GEO databases. Patients were clustered based on EMT and metabolism scores calculated by ssGSEA. The immune-related differentially expressed genes (DEGs) between the two clusters with the most obvious differences were used to construct the signature by LASSO and Cox analysis. Time-dependent receiver operating characteristic (ROC) curves and Kaplan–Meier curves were utilized to evaluate the gene signature in training and validation cohorts. Finally, the function of the signature genes AHNAK and NFATC1 in BLCA cell lines were explored by cytological experiments.

Results

Based on the results of ssGSEA, TCGA patients were divided into three clusters, among which cluster 1 and cluster 3 had completely opposite EMT and metabolic status. Patients in cluster 3 had a significantly worse clinical prognosis than cluster 1. Immune-related DEGs were selected between the two clusters to construct the predictive signature based on 14 genes. High-risk patients had poorer prognosis, lower proportions of CD8⁺ T cells, higher EMT and carbohydrate metabolism, and less sensitivity to chemotherapy and immunotherapy. Overexpression of AHNAK or NFATC1 promoted the proliferation, migration and invasion of T24 and UMUC3 cells. Silencing ANHAK or NFATC1 could effectively inhibit EMT and metabolism in T24 and UMUC3 cells.

Conclusion

The established immune signature may act as a promising model for generating accurate prognosis for patients and predicting their EMT and metabolic status, thus guiding the treatment of BLCA patients.

Cellular and molecular insights into the roles of visfatin in breast cancer cells plasticity programs

Obesity has reached a pandemic proportion and is responsible for the augmentation of multimorbidity including certain cancers. With the rise in obesity amongst the female population globally, a concomitant increase in breast cancer (BC) incidence and related mortality has been observed. In the present review, we have elucidated the cellular and molecular insight into the visfatin-mediated cellular plasticity programs such as Epithelial to mesenchymal transition (EMT) and Endothelial to mesenchymal transition (EndoMT), and stemness-associated changes in BC cells. EMT and EndoMT are responsible for inducing metastasis in cancer cells and conferring chemotherapy resistance, immune escape, and infinite growth potential. Visfatin, an obesity-associated adipokine implicated in metabolic syndrome, has emerged as a central player in BC pathogenesis. Several studies have indicated the presence of visfatin in the tumor microenvironment (TME) where it augments EMT and EndoMT of BC cells. Further, Visfatin also modulates the TME by acting on the tumor stroma cells such as adipocytes, infiltrated immune cells, and adipose-associated stem cells that secrete factors such as cytokines, and extracellular vesicles responsible for augmenting cellular plasticity program. Visfatin induced altered metabolism of the cancer cells and molecular determinants such as non-coding RNAs involved in EMT and EndoMT have been discussed. We have also highlighted specific therapeutic targets that can be exploited for the development of effective BC treatment. Taken together, these advanced understandings of cellular and molecular insight into the visfatin-mediated cellular plasticity programs may stimulate the development of better approaches for the prevention and therapy of BC, especially in obese patients.

Novel Insights on Lipid Metabolism Alterations in Drug Resistance in Cancer

Chemotherapy is one of the primary treatments for most human cancers. Despite great progress in cancer therapeutics, chemotherapy continues to be important for improving the survival of cancer patients, especially for those who has unresectable metastatic tumors or fail to respond to immunotherapy. However, intrinsic or acquired chemoresistance results in tumor recurrence, which remains a major obstacle in anti-cancer treatment. The high prevalence of chemoresistant cancer makes it urgent to deepen our understanding on chemoresistance mechanisms and to develop novel therapeutic strategies. Multiple mechanisms, including drug efflux, enhanced DNA damage reparability, increased detoxifying enzymes levels, presence of cancer stem cells (CSCs), epithelial mesenchymal transition (EMT), autophagy, ferroptosis and resistance to apoptosis, underlie the development of chemoresistance. Recently, accumulating evidence suggests that lipid metabolism alteration is closely related to drug resistance in tumor. Targeting lipid metabolism in combination with traditional chemotherapeutic drugs is a promising strategy to overcome drug resistance. Therefore, this review compiles the current knowledge about aberrant lipid metabolism in chemoresistant cancer, mainly focusing on aberrant fatty acid metabolism, and presents novel therapeutic strategies targeting altered lipid metabolism to overcome chemoresistance in cancer.

The Interplay Between TGF-β Signaling and Cell Metabolism

The transforming growth factor-β (TGF-β) signaling plays a critical role in the development and tissue homeostasis in metazoans, and deregulation of TGF-β signaling leads to many pathological conditions. Mounting evidence suggests that TGF-β signaling can actively alter metabolism in diverse cell types. Furthermore, metabolic pathways, beyond simply regarded as biochemical reactions, are closely intertwined with signal transduction. Here, we discuss the role of TGF-β in glucose, lipid, amino acid, redox and polyamine metabolism with an emphasis on how TGF-β can act as a metabolic modulator and how metabolic changes can influence TGF-β signaling. We also describe how interplay between TGF-β signaling and cell metabolism regulates cellular homeostasis as well as the progression of multiple diseases, including cancer.

Metabostemness in cancer: Linking metaboloepigenetics and mitophagy in remodeling cancer stem cells

Cancer stem cells (CSCs) are rare populations of malignant cells with stem cell-like features of self-renewal, uninterrupted differentiation, tumorigenicity, and resistance to conventional therapeutic agents, and these cells have a decisive role in treatment failure and tumor relapse. The self-renewal potential of CSCs with atypical activation of developmental signaling pathways involves the maintenance of stemness to support cancer progression. The acquisition of stemness in CSCs has been accomplished through genetic and epigenetic rewiring following the metabolic switch. In this context, "metabostemness" denotes the metabolic parameters that essentially govern the epitranscriptional gene reprogramming mechanism to dedifferentiate tumor cells into CSCs. Several metabolites often referred to as oncometabolites can directly remodel chromatin structure and thereby influence the operation of epitranscriptional circuits. This integrated metaboloepigenetic dimension of CSCs favors the differentiated cells to move in dedifferentiated macrostates. Some metabolic events might perform as early drivers of epitranscriptional reprogramming; however, subsequent metabolic hits may govern the retention of stemness properties in the tumor mass. Interestingly, selective removal of mitochondria through autophagy can promote metabolic plasticity and alter metabolic states during differentiation and dedifferentiation. In this connection, novel metabostemness-specific drugs can be generated as potential cancer therapeutics to target the metaboloepigenetic circuitry to eliminate CSCs.

Increased Expression of LIPC Is Associated with Aggressive Phenotype of Borrmann Type 4 Gastric Cancer

PURPOSE

To investigate lipase C hepatic type (LIPC) expression in Borrmann type 4 gastric cancer and its correlation with clinical outcome. The biological roles of LIPC in Borrmann type 4 gastric cancer progression were also investigated.

METHODS

We determined LIPC expression in 324 primary gastric cancer tissues and 178 matched adjacent non-tumor tissues by immunohistochemistry. We explored the role of LIPC in Borrmann type 4 gastric cancer cell (OCUM-1) migration, invasion, proliferation, cell cycle, and expression of epithelial-mesenchymal transition-related genes by knocking down LIPC expression.

RESULTS

LIPC expression was upregulated in Borrmann type 4 gastric cancer tissues compared with other types of gastric cancer and adjacent non-tumor tissues. High LIPC expression correlated with lymph node metastasis, advanced TNM stage, and poor overall survival in Borrmann type 4 gastric cancer patients. Multivariate analysis demonstrated that high LIPC expression was an independent prognostic factor in patients with Borrmann type 4 gastric cancer. By reducing LIPC expression, OCUM-1 cell invasion and migration were suppressed and Snail and MMP2 expression was downregulated, while E-cadherin expression was upregulated.

CONCLUSIONS

High LIPC expression correlates with poor clinical outcome and plays an important role in regulating cell migration and invasion in Borrmann type 4 gastric cancer.

Fat and Furious: Lipid Metabolism in Antitumoral Therapy Response and Resistance

Lipid metabolic reprogramming is an established trait of cancer metabolism that guides response and resistance to antitumoral therapies. Enhanced lipogenesis, increased lipid content (either free or stored into lipid droplets), and lipid-dependent catabolism sustain therapy desensitization and the emergence of a resistant phenotype of tumor cells exposed to chemotherapy or targeted therapies. Aberrant lipid metabolism, therefore, has emerged as a potential metabolic vulnerability of therapy-resistant cancers that could be exploited for therapeutic interventions or for identifying tumors more likely to respond to further lines of therapies. This review gathers recent findings on the role of aberrant lipid metabolism in influencing antitumoral therapy response and in sustaining the emergence of resistance.

Metabolic Constrains Rule Metastasis Progression

Metastasis formation accounts for the majority of tumor-associated deaths and consists of different steps, each of them being characterized by a distinctive adaptive phenotype of the cancer cells. Metabolic reprogramming represents one of the main adaptive phenotypes exploited by cancer cells during all the main steps of tumor and metastatic progression. In particular, the metabolism of cancer cells evolves profoundly through all the main phases of metastasis formation, namely the metastatic dissemination, the metastatic colonization of distant organs, the metastatic dormancy, and ultimately the outgrowth into macroscopic lesions. However, the metabolic reprogramming of metastasizing cancer cells has only recently become the subject of intense study. From a clinical point of view, the latter steps of the metastatic process are very important, because patients often undergo surgical removal of the primary tumor when cancer cells have already left the primary tumor site, even though distant metastases are not clinically detectable yet. In this scenario, to precisely elucidate if and how metabolic reprogramming drives acquisition of cancer-specific adaptive phenotypes might pave the way to new therapeutic strategies by combining chemotherapy with metabolic drugs for better cancer eradication. In this review we discuss the latest evidence that claim the importance of metabolic adaptation for cancer progression.

MicroRNA-302 represses epithelial-mesenchymal transition and cisplatin resistance by regulating ATAD2 in ovarian carcinoma

Epithelial-mesenchymal transition (EMT) is an important contributor to drug resistance in ovarian cancer. The aims of this study were to explore the potential role of the miR-302 cluster in modulating EMT and cisplatin resistance in ovarian cancer. We used qRT-PCR and western blotting to show that miR-302 expression was lower in chemoresistant than in chemosensitive cells, and miR-302 was upregulated in chemosensitive, but not chemoresistant ovarian cancer cells in response to cisplatin treatment. We identified ATAD2 as a target of miR-302 and showed that ectopic expression of miR-302 increased cisplatin sensitivity and inhibited EMT and the invasiveness of cisplatin-resistant cells in vitro by targeting ATAD2. Knockdown of ATAD2 restored cisplatin sensitivity and reversed EMT/metastasis in cisplatin-resistant cells, as shown by western blotting and invasion/migration assays. The effect of miR-302 overexpression on EMT and invasiveness was mediated by the modulation of β-catenin nuclear expression. Immunofluorescence analysis showed that ATAD2 overexpression reversed the miR-302-induced downregulation of nuclear β-catenin in cisplatin resistant cells. A xenograft tumor model was used to show that miR-302 increases the antitumor effect of cisplatin in vivo. Taken together, these results identify a potential regulatory axis involving miR-302 and ATAD2 with a role in chemoresistance, indicating that activation of miR-302 or inactivation of ATAD2 could serve as a novel approach to reverse cisplatin resistance in ovarian cancer.

Fatty acid synthase contributes to epithelial-mesenchymal transition and invasion of salivary adenoid cystic carcinoma through PRRX1/Wnt/β-catenin pathway

Fatty acid synthase (FASN) has been shown to be selectively up‐regulated in cancer cells to drive the development of cancer. However, the role and associated mechanism of FASN in regulating the malignant progression of salivary adenoid cystic carcinoma (SACC) still remains unclear. In this study, we demonstrated that FASN inhibition attenuated invasion, metastasis and EMT of SACC cells as well as the expression ofPRRX1, ZEB1, Twist, Slug and Snail, among which the level of PRRX1 changed the most obviously. Overexpression of PRRX1 restored migration and invasion in FASN knockdown cells, indicating that PRRX1 is an important downstream target of FASN signalling. Levels of cyclin D1 and c‐Myc, targets of Wnt/β‐catenin pathway, were significantly decreased by FASN silencing and restored by PRRX1 overexpression. In addition, FASN expression was positively associated with metastasis and poor prognosis of SACC patients as well as with the expression of PRRX1, cyclin D1 and c‐Myc in SACC tissues. Our findings revealed that FASN in SACC progression may induce EMT in a PRRX1/Wnt/β‐catenin dependent manner.

Epithelial-Mesenchymal Transition and Metabolic Switching in Cancer: Lessons From Somatic Cell Reprogramming

Epithelial-mesenchymal transition (EMT) and its critical roles during cancer progression have long been recognized and extensively reviewed. Recent studies on the generation of induced pluripotent stem cells (iPSCs) have established the connections among EMT, energy metabolism, DNA methylation, and histone modification. Since energy metabolism, DNA methylation, and histone modification are important for cancer development and there are common characteristics between cancer cells and stem cells, it is reasonable to identify mechanisms that have been established during both reprogramming and cancer progression. In the current review, we start from a brief review on EMT and related processes during cancer progression, and then switch to the EMT during somatic cell reprogramming. We summarize the connection between EMT and metabolic switch during reprogramming, and further review the involvements of DNA methylation and cell proliferation. The connections between EMT and mesenchymal-epithelial transition (MET) and cellular aspects including DNA methylation, histone modification and energy metabolism may provide potential new targets for cancer diagnosis and treatment.

Association of the Epithelial-Mesenchymal Transition (EMT) with Cisplatin Resistance

Therapy resistance is a characteristic of cancer cells that significantly reduces the effectiveness of drugs. Despite the popularity of cisplatin (CP) as a chemotherapeutic agent, which is widely used in the treatment of various types of cancer, resistance of cancer cells to CP chemotherapy has been extensively observed. Among various reported mechanism(s), the epithelial–mesenchymal transition (EMT) process can significantly contribute to chemoresistance by converting the motionless epithelial cells into mobile mesenchymal cells and altering cell–cell adhesion as well as the cellular extracellular matrix, leading to invasion of tumor cells. By analyzing the impact of the different molecular pathways such as microRNAs, long non-coding RNAs, nuclear factor-κB (NF-ĸB), phosphoinositide 3-kinase-related protein kinase (PI3K)/Akt, mammalian target rapamycin (mTOR), and Wnt, which play an important role in resistance exhibited to CP therapy, we first give an introduction about the EMT mechanism and its role in drug resistance. We then focus specifically on the molecular pathways involved in drug resistance and the pharmacological strategies that can be used to mitigate this resistance. Overall, we highlight the various targeted signaling pathways that could be considered in future studies to pave the way for the inhibition of EMT-mediated resistance displayed by tumor cells in response to CP exposure.

TGFβ-induced metabolic reprogramming during epithelial-to-mesenchymal transition in cancer

Metastasis is the most frequent cause of death in cancer patients. Epithelial-to-mesenchymal transition (EMT) is the process in which cells lose epithelial integrity and become motile, a critical step for cancer cell invasion, drug resistance and immune evasion. The transforming growth factor-β (TGFβ) signaling pathway is a major driver of EMT. Increasing evidence demonstrates that metabolic reprogramming is a hallmark of cancer and extensive metabolic changes are observed during EMT. The aim of this review is to summarize and interconnect recent findings that illustrate how changes in glycolysis, mitochondrial, lipid and choline metabolism coincide and functionally contribute to TGFβ-induced EMT. We describe TGFβ signaling is involved in stimulating both glycolysis and mitochondrial respiration. Interestingly, the subsequent metabolic consequences for the redox state and lipid metabolism in cancer cells are found to be in favor of EMT as well. Combined we illustrate that a better understanding of the mechanistic links between TGFβ signaling, cancer metabolism and EMT holds promising strategies for cancer therapy, some of which are already actively being explored in the clinic.

Metabolic Reprogramming and Epithelial-Mesenchymal Plasticity: Opportunities and Challenges for Cancer Therapy

Metabolic reprogramming and epithelial-mesenchymal plasticity are both hallmarks of the adaptation of cancer cells for tumor growth and progression. For metabolic changes, cancer cells alter metabolism by utilizing glucose, lipids, and amino acids to meet the requirement of rapid proliferation and to endure stressful environments. Dynamic changes between the epithelial and mesenchymal phenotypes through epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are critical steps for cancer invasion and metastatic colonization. Compared to the extensively studied metabolic reprogramming in tumorigenesis, the metabolic changes in metastasis are relatively unclear. Here, we review metabolic reprogramming, epithelial-mesenchymal plasticity, and their mutual influences on tumor cells. We also review the developing treatments for targeting cancer metabolism and the impact of metabolic targeting on EMT. In summary, understanding the metabolic adaption and phenotypic plasticity will be mandatory for developing new strategies to target metastatic and refractory cancers that are intractable to current treatments.

Evaluation of FASN inhibitors by a versatile toolkit reveals differences in pharmacology between human and rodent FASN preparations and in antiproliferative efficacy in vitro vs. in situ in human cancer cells

De novo synthesis of fatty acids is essential to maintain intensive proliferation of cancer cells. Unlike normal cells that utilize food-derived circulating lipids for their fuel, cancer cells rely on heightened lipogenesis irrespective of exogenous lipid availability. Overexpression and activity of the multidomain enzyme fatty acid synthase (FASN) is crucial in supplying palmitate for protumorigenic activity. Therefore, FASN has been proposed as an attractive target for drug development. As an effort to set up an effective toolkit to study FASN inhibitors in human and rodent tissues, we validated activity-based protein profiling (ABPP) as a viable approach to unveil inhibitors targeting FASN thioesterase domain (FASN-TE). ABPP was combined with multi-well plate-assays designed for classical substrate-based FASN activity analysis together with powerful monitoring of cancer cell proliferation using IncuCyte® Live Cell Analyzing System. FASN-TE inhibitors were identified by competitive ABPP using HEK293 cell lysates in a screen of in-house compounds (200+) designed to target serine hydrolase (SH) family. The identified compounds were tested for their inhibitor potencies in vitro using a substrate-based activity assay monitoring FASN-dependent NADPH consumption in LNCaP prostate cancer cell preparation, in parallel with selected reference inhibitors, including orlistat (THL), GSK2194069, GSK837149A, platensimycin and BI-99179. LNCaP lysate supernatant was validated as a reliable native preparation to monitor FASN-dependent NADPH consumption as opposed to human glioma GAMG cells, whereas FASN enrichment was a prerequisite for accurate assays. While inhibitor pharmacology was identical between human prostate and glioma cancer cell FASN preparations, notable differences were revealed between human and rodent FASN preparations, especially for inhibitors targeting FASN-TE. ABPP combined with substrate-based assays facilitated identification of pan thiol-reactive inhibitor scaffolds, exemplified by the 1,2,4-thiadiazole moiety. Finally, selected compounds were evaluated for their antiproliferative efficacy in situ using GAMG cells. These studies revealed that while the tested compounds acted as potent FASN inhibitors in vitro, only a few showed antiproliferative efficacy in situ. To conclude, we describe a versatile toolkit to study FASN inhibitors in vitro and in situ using human cancer cells and reveal dramatic pharmacological differences between human and rodent FASN preparations.

Anti-Cancer and Ototoxicity Characteristics of the Curcuminoids, CLEFMA and EF24, in Combination with Cisplatin

In this study, we investigated whether the curcuminoids, CLEFMA and EF24, improved cisplatin efficacy and reduced cisplatin ototoxicity. We used the lung cancer cell line, A549, to determine the effects of the curcuminoids and cisplatin on cell viability and several apoptotic signaling mechanisms. Cellular viability was measured using the MTT assay. A scratch assay was used to measure cell migration and fluorescent spectrophotometry to measure reactive oxygen species (ROS) production. Western blots and luminescence assays were used to measure the expression and activity of apoptosis-inducing factor (AIF), caspases-3/7, -8, -9, and -12, c-Jun N-terminal kinases (JNK), mitogen-activated protein kinase (MAPK), and proto-oncogene tyrosine-protein kinase (Src). A zebrafish model was used to evaluate auditory effects. Cisplatin, the curcuminoids, and their combinations had similar effects on cell viability (IC₅₀ values: 2-16 μM) and AIF, caspase-12, JNK, MAPK, and Src expression, while caspase-3/7, -8, and -9 activity was unchanged or decreased. Cisplatin increased ROS yield (1.2-fold), and curcuminoid and combination treatments reduced ROS (0.75-0.85-fold). Combination treatments reduced A549 migration (0.51-0.53-fold). Both curcuminoids reduced auditory threshold shifts induced by cisplatin. In summary, cisplatin and the curcuminoids might cause cell death through AIF and caspase-12. The curcuminoids may potentiate cisplatin's effect against A549 migration, but may counteract cisplatin's effect to increase ROS production. The curcuminoids might also prevent cisplatin ototoxicity.

Prognostic value of TGF-β in lung cancer: systematic review and meta-analysis

Background

Lung cancer is the most important cause of cancer-related deaths worldwide and the overall survival of patients with non-small cell lung cancer has not improved. Transforming growth factor beta or TGF-β is a polypeptide member of the transforming growth factor beta superfamily of cytokines, while far fewer clinical studies addressing the association between TGF-β expression and the disease prognosis have been reported up to now. Therefore, our meta-analysis aims to determine the prognostic significance of TGF-β expression in lung cancer patients.

Methods

PubMed, EMBASE, the Web of Science and China National Knowledge Infrastructure (CNKI) databases were searched for full-text literature citations. We applied the hazard ratio (HR) with 95% confidence interval (CI) as the appropriate summarized statistics. Q-test and I² statistic were used to estimate the level of heterogeneity. The publication bias was detected by Begg’s test and Egger’s test.

Results

Eight eligible studies involving 579 patients were selected for this meta-analysis. The combined HR for the eight eligible studies was 2.17 (95% CI: 1.71–2.77, P < 0.00001) and heterogeneity of overall prognosis was relatively low (I² = 14.2%, P = 0.319). We further undertook the subgroup analysis including assessment of the association between TGF-β expression and pathology of the lung cancer, treatment and quantity of sample in studies. All the results revealed that a significantly high TGF-β expression in patients was an indicator of poor survival. Neither Begg’s test nor Egger’s test found publication bias in any analysis.

Conclusions

The present evidence indicates that TGF-β expression can significantly predict the worse prognosis in patients with lung cancer. The findings of our meta-analysis may be confirmed in the future by the use of more updated review pooling and additional relevant investigations.

Screening miRNAs associated with resistance gemcitabine from exosomes in A549 lung cancer cells

Purpose

To establish a gemcitabine-resistant lung adenocarcinoma cell line, A549/G+, and to screen the differences of miRNA expression in exosomes from A549 and A549/G+ cells.

Methods

A549 cells were exposed in gemcitabine until they were resistant to gemcitabine, and extracted exosomes from A549 and A549/G+. The RNAs from exosomes were subjected to miRNA expression microarray experiments.

Results

After 39 weeks of continuous induction, we induced drug resistance in A549 cells. The resistance index was 6. Via GeneChip miRNA 4.0 analysis, there were 446 differential miRNAs between A549 and A549/G+. Target gene prediction and pathway analysis discovered the microRNAs in the intersections may participate in drug resistance.

Conclusion

These differential miRNAs help to do in-depth research to elucidate the mechanism of resistance to gemcitabine in non-small cell lung cancer.

Role of Metabolic Reprogramming in Epithelial⁻Mesenchymal Transition (EMT)

Activation of epithelial–mesenchymal transition (EMT) is thought to be an essential step for cancer metastasis. Tumor cells undergo EMT in response to a diverse range of extra- and intracellular stimulants. Recently, it was reported that metabolic shifts control EMT progression and induce tumor aggressiveness. In this review, we summarize the involvement of altered glucose, lipid, and amino acid metabolic enzyme expression and the underlying molecular mechanisms in EMT induction in tumor cells. Moreover, we propose that metabolic regulation through gene-specific or pharmacological inhibition may suppress EMT and this treatment strategy may be applied to prevent tumor progression and improve anti-tumor therapeutic efficacy. This review presents evidence for the importance of metabolic changes in tumor progression and emphasizes the need for further studies to better understand tumor metabolism.

Inhibition of ATM reverses EMT and decreases metastatic potential of cisplatin-resistant lung cancer cells through JAK/STAT3/PD-L1 pathway

Background

The cisplatin-resistance is still a main course for chemotherapy failure of lung cancer patients. Cisplatin-resistant cancer cells own higher malignance and exhibited increased metastatic ability, but the mechanism is not clear. In this study, we investigated the effects of Ataxia Telangiectasia Mutated (ATM) on lung cancer metastasis.

Materials and methods

Cisplatin-resistant A549CisR and H157CisR cell line were generated by long-term treating parental A549 and H157 cells (A549P and H157P) with cisplatin. Cell growth, cell migration and cell invasion were determined. Gene expressions were determined by Western Blot and qPCR. Tumor metastasis was investigated using a xenograft mouse model.

Results

The IC50 of the cisplatin-resistant cells (A549CisR and H157CisR cells) to cisplatin was 6–8 higher than parental cells. The A549CisR and H157CisR cells expressed lower level of E-cadherin and higher levels of N-cadherin, Vimentin and Snail compared to the parental A549P and H157P cells, and exhibited stronger capabilities of metastatic potential compared to the parental cells. The ATM expression was upregulated in A549CisR and H157CisR cells and cisplatin treatment also upregulated expression of ATM in parental cells, The inhibition of ATM by using specific ATM inhibitor CP466722 or knock-down ATM by siRNA suppressed Epithelial-to-Mesenchymal transition (EMT) and metastatic potential of A549CisR and H157CisR cells. These data suggest that ATM mediates the cisplatin-resistance in lung cancer cells. Expressions of JAK_1,2,、 STAT₃ 、PD-L1 and ATM were increased in A549CisR and H157CisR cells and could by induced by cisplatin in parental lung cancer cells. Interestedly, ATM upregulated PD-L1 expression via JAK_1,2/STAT₃ pathway and inhibition of ATM decreased JAK/STAT3 signaling and decreased PD-L1 expression. The treatment of PD-L1 neutralizing Ab reduced EMT and cell invasion. Inhibition of JAK_1,2/STAT₃ signaling by specific inhibitors suppressed ATM-induced PD-L1 expression, EMT and cell invasion. Importantly, inhibition of ATM suppressed EMT and tumor metastasis in cisplatin-resistant lung cancer cells in an orthotopic xenograft mouse model.

Conclusions

Our results show that ATM regulates PD-L1 expression through activation of JAK/STAT3 signaling in cisplatin-resistant cells. Overexpression of ATM contributes to cisplatin-resistance in lung cancer cells. Inhibition of ATM reversed EMT and inhibited cell invasion and tumor metastasis. Thus, ATM may be a potential target for the treatment of cisplatin-resistant lung cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1161-8) contains supplementary material, which is available to authorized users.

Targeting lipid metabolism to overcome EMT-associated drug resistance via integrin β3/FAK pathway and tumor-associated macrophage repolarization using legumain-activatable delivery

Epithelial-mesenchymal transition (EMT) is closely associated with the development of drug resistance. Lipid metabolism plays an important role in EMT. This work was to study the cholesterol-lowering drug simvastatin for reversing EMT-associated resistance to chemotherapy via lipid metabolism.

Methods: The combination of simvastatin and paclitaxel was used to overcome the EMT-associated drug resistance. For dual-action on both cancer cells and tumor-associated macrophages (TAM), the tumor microenvironment-activatable multifunctional liposomes were developed for drug codelivery. The liposomes were modified with a hairpin-structured, activatable cell-penetrating peptide that is specifically responsive to the tumor-associated protease legumain.

Results: It was revealed simvastatin can disrupt lipid rafts (cholesterol-rich domains) and suppress integrin-β3 and focal adhesion formation, thus inhibiting FAK signaling pathway and re-sensitizing the drug-resistant cancer cells to paclitaxel. Furthermore, simvastatin was able to re-polarize tumor-associated macrophages (TAM), promoting M2-to-M1 phenotype switch via cholesterol-associated LXR/ABCA1 regulation. The repolarization increased TNF-α, but attenuated TGF-β, which, in turn, remodeled the tumor microenvironment and suppressed EMT. The liposomal formulation achieved enhanced treatment efficacy.

Conclusion: This study provides a promising simvastatin-based nanomedicine strategy targeting cholesterol metabolism to reverse EMT and repolarize TAM to treat drug-resistant cancer. The elucidation of the molecular pathways (cholesterol/lipid raft/integrin β3/FAK and cholesterol-associated LXR/ABCA1 regulation) for anti-EMT and the new application of simvastatin should be of clinical significance.

Oncogenic Metabolism Acts as a Prerequisite Step for Induction of Cancer Metastasis and Cancer Stem Cell Phenotype

Metastasis is a major obstacle to the efficient and successful treatment of cancer. Initiation of metastasis requires epithelial-mesenchymal transition (EMT) that is regulated by several transcription factors, including Snail and ZEB1/2. EMT is closely linked to the acquisition of cancer stem cell (CSC) properties and chemoresistance, which contribute to tumor malignancy. Tumor suppressor p53 inhibits EMT and metastasis by negatively regulating several EMT-inducing transcription factors and regulatory molecules; thus, its inhibition is crucial in EMT, invasion, metastasis, and stemness. Metabolic alterations are another hallmark of cancer. Most cancer cells are more dependent on glycolysis than on mitochondrial oxidative phosphorylation for their energy production, even in the presence of oxygen. Cancer cells enhance other oncogenic metabolic pathways, such as glutamine metabolism, pentose phosphate pathway, and the synthesis of fatty acids and cholesterol. Metabolic reprogramming in cancer is regulated by the activation of oncogenes or loss of tumor suppressors that contribute to tumor progression. Oncogenic metabolism has been recently linked closely with the induction of EMT or CSC phenotypes by the induction of several metabolic enzyme genes. In addition, several transcription factors and molecules involved in EMT or CSCs, including Snail, Dlx-2, HIF-1α, STAT3, TGF-β, Wnt, and Akt, regulate oncogenic metabolism. Moreover, p53 induces metabolic change by directly regulating several metabolic enzymes. The collective data indicate the importance of oncogenic metabolism in the regulation of EMT, cell invasion and metastasis, and adoption of the CSC phenotype, which all contribute to malignant transformation and tumor development. In this review, we highlight the oncogenic metabolism as a key regulator of EMT and CSC, which is related with tumor progression involving metastasis and chemoresistance. Targeting oncometabolism might be a promising strategy for the development of effective anticancer therapy.

SREBF1 Activity Is Regulated by an AR/mTOR Nuclear Axis in Prostate Cancer

Reprogramming of cellular metabolism is an important feature of prostate cancer, including altered lipid metabolism. Recently, it was observed that the nuclear fraction of mTOR is essential for the androgen-mediated metabolic reprogramming of prostate cancer cells. Herein, it is demonstrated that the androgen receptor (AR) and mTOR bind to regulatory regions of sterol regulatory element-binding transcription factor 1 (SREBF1) to control its expression, whereas dual activation of these signaling pathways also promotes SREBF1 cleavage and its translocation to the nucleus. Consequently, SREBF1 recruitment to regulatory regions of its target genes is induced upon treatment with the synthetic androgen R1881, an effect abrogated upon inhibition of the mTOR signaling pathway. In turn, pharmacologic and genetic inhibition of SREBF1 activity impairs the androgen-mediated induction of the key lipogenic genes fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD1). Consistent with these observations, the expression of the SREBF1, FASN, and SCD1 genes is significantly correlated in human prostate cancer tumor clinical specimens. Functionally, blockade of SREBF1 activity reduces the androgen-driven lipid accumulation. Interestingly, decreased triglyceride accumulation observed upon SREBF1 inhibition is paralleled by an increase in mitochondrial respiration, indicating a potential rewiring of citrate metabolism in prostate cancer cells. Altogether, these data define an AR/mTOR nuclear axis, in the context of prostate cancer, as a novel pathway regulating SREBF1 activity and citrate metabolism.Implications: The finding that an AR/mTOR complex promotes SREBF1 expression and activity enhances our understanding of the metabolic adaptation necessary for prostate cancer cell growth and suggests novel therapeutic approaches to target metabolic vulnerabilities in tumors. Mol Cancer Res; 16(9); 1396-405. ©2018 AACR.

Effects of miR-144 on the sensitivity of human anaplastic thyroid carcinoma cells to cisplatin by autophagy regulation

BACKGROUND

We investigated the influence of miR-144 on the cisplatin-sensitivity of anaplastic thyroid carcinoma (ATC) cells and explored the internal molecular mechanism of miR-144.

METHODS

Thyroid cancer cells ARO, TPC1 and normal thyroid cells HT-ori3 were used in this research. Expressions of miR-144 and TGF-α were uncovered by western blot and qRT-PCR. Expressions of autophagy-related protein LC3 II and apoptosis-related protein Caspase-3 and PARP were explored by western blot and immunofluorescence. Cell viability was detected by MTT assay and apoptosis condition was revealed by flow cytometric analysis and TUNEL staining. Dual-luciferase reporter assay was employed to verify the target relationship. Tissue sections were detected by IHC. Xenograft assay was conducted to further verify conclusions in vivo.

RESULTS

MiR-144, which was low expressed in ATC cells and tissues, could inhibit autophagy activation induced by cisplatin, enhancing the sensitivity of ATC cells to cisplatin, and promoting cell apoptosis. TGF-α was the target of miR-144 and was negatively regulated by it. MiR-144 could improve the sensitivity of ATC cells to cisplatin and inhibit tumor growth by suppressing TGF-α both in vitro and in vivo.

CONCLUSION

MiR-144 could inhibit autophagy of ATC cells by down-regulating TGF-α, enhancing the cisplatin-sensitivity of ATC cells.

Prospects for new lung cancer treatments that target EMT signaling

Lung cancer is the most common cancer worldwide. Treatment options for lung cancer include surgery, radiation therapy, chemotherapy, molecularly targeted therapy including epidermal growth factor receptor or anaplastic lymphoma kinase inhibitors, and immunotherapy. These treatments can be administered alone or in combination. Despite therapeutic advances, however, lung cancer remains the leading cause of cancer death. Recent studies have indicated that epithelial-mesenchymal transition (EMT) is associated with malignancy in various types of cancer, and activation of EMT signaling in cancer cells is widely considered to contribute to metastasis, recurrence, or therapeutic resistance. In this review, we provide an overview of the role of EMT in the progression of lung cancer. We also discuss the prospects for new therapeutic strategies that target EMT signaling in lung cancer. Developmental Dynamics 247:462-472, 2018. © 2017 Wiley Periodicals, Inc.

Mechanistic Study of Bakuchiol-Induced Anti-breast Cancer Stem Cell and in Vivo Anti-metastasis Effects

Cancer stem cells are involved in cancer establishment, progression, and resistance to current treatments. We demonstrated the in vitro and in vivo anti-breast cancer effect of bakuchiol in a previous study. However, the ability of bakuchiol to target breast cancer stem cells (BCSCs) and inhibit breast cancer metastasis remains unknown. In the current study, we used the cell surface markers CD44 and CD24 to distinguish BCSCs from MCF-7 cells. Bakuchiol inhibited mammosphere formation and aldehyde dehydrogenase activity in BCSCs. Moreover, bakuchiol induced apoptosis and suppressed the mitochondrial membrane potential of BCSCs. Bakuchiol upregulated the expression levels of pro-apoptotic genes, BNIP3 and DAPK2. Bakuchiol induced oxidative stress and altered lipogenesis in BCSCs. In zebrafish xenografts, bakuchiol inhibited breast cancer cell metastasis in vivo. In addition, bakuchiol altered the expression levels of metastasis-related genes through upregulating CK18 and downregulating Notch3, FASN, TGFBR1, and ACVR1B. Our study provides evidence for the anti-breast cancer potential of bakuchiol.

Apoptosis induced by the methanol extract of Salvia miltiorrhiza Bunge in non-small cell lung cancer through PTEN-mediated inhibition of PI3K/Akt pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge, a well-known traditional Chinese medicinal (TCM) plant, has been used to treat cardiovascular diseases since thousands of years. Many studies reported that the active component tanshinones displayed a variety of biological activities: anti-thrombous, anti-allergic, anti-inflammatory, antioxidant and anti-tumor promoting. But the mechanism of how the active components working still need to be clarified. The anti-tumor effect of compounds of tanshinone (CTN), the methanol extract of Salvia miltiorrhiza Bunge roots, was investigated. The aim of this study was to investigate the effects of CTN on the growth inhibition, apoptosis and molecular targets of human non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

CTN-induced cytotoxicity was determined by MTT assay. The cell survival was evaluated using clonogenic survival assay. The morphology of Glc-82 cells after treatment with CTN was determined by fluorescence microscopy. Cell cycle distribution was revealed by flow cytometry. The apoptotic cells were quantified with annexin V-FITC/PI staining and flow cytometry, and observed using Hoechst 33258 staining and TUNEL assays. The expression levels of proteins were analyzed using western blot. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice.

RESULTS

CTN inhibited the proliferation of NSCLC in a dose-dependent manner and induced both early and late apoptosis. Treatment of Glc-82 cells with CTN (5-80μg/ml) significantly (p<0.05) suppressed the cell proliferation in a concentration and time-dependent manner. CTN induced significant (p<0.05) and dose-dependent apoptosis of Glc-82 cells. Cell cycle assay showed that CTN induced a G₂/M phase arrest, and significantly (p<0.05) increased expression of p53 and p21, actived caspase-3/9 and PARP1, which suggest the involvement of the mitochondria in the apoptotic signals. In addition, CTN decreased expression of the anti-apoptotic protein Bcl-2, Bcl-xl and increased expression of the pro-apoptotic protein Bax. Result also showed that CTN could increase expression levels of PTEN, and reduce the phosphorylated levels of Akt (protein kinase B) on Thr 308 and Ser 473 domain. In vivo assay showed that the antitumor effect of CTN was significantly augmented without increasing toxicity in nude mice bearing Glc-82 xenograft.

CONCLUSION

The PTEN/Akt signaling axis is defined as a critical pathway regulated by PTEN in NSCLC. CTN, the methanol extract of Salvia miltiorrhiza Bunge, are the active compounds as shown by their ability to induce apoptosis through the mitochondrial pathway of apoptosis and PTEN-mediated inhibition of PI3K/Akt pathway. CTN could inhibit tumor growth more efficiently, which supports the ethno-medicinal use of this herb as an alternative or complementary therapy for NSCLC.

Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer cells by ionizing radiation

Radiation therapy is one of the major tools of cancer treatment, and is widely used for a variety of malignant tumours. Radiotherapy causes DNA damage directly by ionization or indirectly via the generation of reactive oxygen species (ROS), thereby destroying cancer cells. However, ionizing radiation (IR) paradoxically promotes metastasis and invasion of cancer cells by inducing the epithelial-mesenchymal transition (EMT). Metastasis is a major obstacle to successful cancer therapy, and is closely linked to the rates of morbidity and mortality of many cancers. ROS have been shown to play important roles in mediating the biological effects of IR. ROS have been implicated in IR-induced EMT, via activation of several EMT transcription factors—including Snail, HIF-1, ZEB1, and STAT3—that are activated by signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, G-CSF, EGFR/PI3K/Akt, and MAPK. Cancer cells that undergo EMT have been shown to acquire stemness and undergo metabolic changes, although these points are debated. IR is known to induce cancer stem cell (CSC) properties, including dedifferentiation and self-renewal, and to promote oncogenic metabolism by activating these EMT-inducing pathways. Much accumulated evidence has shown that metabolic alterations in cancer cells are closely associated with the EMT and CSC phenotypes; specifically, the IR-induced oncogenic metabolism seems to be required for acquisition of the EMT and CSC phenotypes. IR can also elicit various changes in the tumour microenvironment (TME) that may affect invasion and metastasis. EMT, CSC, and oncogenic metabolism are involved in radioresistance; targeting them may improve the efficacy of radiotherapy, preventing tumour recurrence and metastasis. This study focuses on the molecular mechanisms of IR-induced EMT, CSCs, oncogenic metabolism, and alterations in the TME. We discuss how IR-induced EMT/CSC/oncogenic metabolism may promote resistance to radiotherapy; we also review efforts to develop therapeutic approaches to eliminate these IR-induced adverse effects.

Iron granules in plasma cells

Resistance of cancer cells to chemotherapy is the first cause of cancer-associated death. Thus, new strategies to deal with the evasion of drug response and to improve clinical outcomes are needed. Genetic and epigenetic mechanisms associated with uncontrolled cell growth result in metabolism reprogramming. Cancer cells enhance anabolic pathways and acquire the ability to use different carbon sources besides glucose. An oxygen and nutrient-poor tumor microenvironment determines metabolic interactions among normal cells, cancer cells and the immune system giving rise to metabolically heterogeneous tumors which will partially respond to metabolic therapy. Here we go into the best-known cancer metabolic profiles and discuss several studies that reported tumors sensitization to chemotherapy by modulating metabolic pathways. Uncovering metabolic dependencies across different chemotherapy treatments could help to rationalize the use of metabolic modulators to overcome therapy resistance.