Clinical importance of FASN in relation to HIF-1α and SREBP-1c in gastric adenocarcinoma

Regulation of fatty acid synthase on tumor and progress in the development of related therapies

ABSTRACT

Fatty acid synthase (FASN) is an essential molecule in lipid metabolic pathways, which are crucial for cancer-related studies. Recent studies have focused on a comprehensive understanding of the novel and important regulatory effects of FASN on malignant biological behavior and immune-cell infiltration, which are closely related to tumor occurrence and development, immune escape, and immune response. FASN-targeting antitumor treatment strategies are being developed. Therefore, in this review, we focused on the effects of FASN on tumor and immune-cell infiltration and reviewed the progress of related anti-tumor therapy development.

Palmer Nodular Fasciitis Harboring a Novel SREBF1::USP6 Fusion Gene

The diagnosis of low-grade fibroblastic/myofibroblastic tumors of acral sites can be challenging. These tumors encompass a diverse group of neoplasms with a spectrum of biologic potential ranges from benign to overtly malignant. They often demonstrate significant clinical, radiologic, and immunophenotypic overlap, in which the molecular phenotype may play an important diagnostic role to arrive at the final diagnosis. Herein, we report a case of soft tissue mass lesion presented on the palm of an adult patient for four months. Histologically, the tumor consisted of primarily low-grade spindle cells expressing smooth muscle actin. Molecular testing revealed a novel SREBF1::USP6 fusion gene, confirming the final diagnosis of nodular fasciitis and ultimately expanding its molecular profile. This case highlights the diagnostic value of single, cost-effective, targeted molecular panel to arrive at an accurate diagnosis and provide helpful therapeutic information.

Targeting Hypoxia-Inducible Factor-1 (HIF-1) in Cancer: Emerging Therapeutic Strategies and Pathway Regulation

Hypoxia-inducible factor-1 (HIF-1) is a key regulator for balancing oxygen in the cells. It is a transcription factor that regulates the expression of target genes involved in oxygen homeostasis in response to hypoxia. Recently, research has demonstrated the multiple roles of HIF-1 in the pathophysiology of various diseases, including cancer. It is a crucial mediator of the hypoxic response and regulator of oxygen metabolism, thus contributing to tumor development and progression. Studies showed that the expression of the HIF-1α subunit is significantly upregulated in cancer cells and promotes tumor survival by multiple mechanisms. In addition, HIF-1 has potential contributing roles in cancer progression, including cell division, survival, proliferation, angiogenesis, and metastasis. Moreover, HIF-1 has a role in regulating cellular metabolic pathways, particularly the anaerobic metabolism of glucose. Given its significant and potential roles in cancer development and progression, it has been an intriguing therapeutic target for cancer research. Several compounds targeting HIF-1-associated processes are now being used to treat different types of cancer. This review outlines emerging therapeutic strategies that target HIF-1 as well as the relevance and regulation of the HIF-1 pathways in cancer. Moreover, it addresses the employment of nanotechnology in developing these promising strategies.

Resensitizing Paclitaxel-Resistant Ovarian Cancer via Targeting Lipid Metabolism Key Enzymes CPT1A, SCD and FASN

Epithelial ovarian cancer (EOC) is a lethal gynecological cancer, of which paclitaxel resistance is the major factor limiting treatment outcomes, and identification of paclitaxel resistance-related genes is arduous. We obtained transcriptomic data from seven paclitaxel-resistant ovarian cancer cell lines and corresponding sensitive cell lines. Define genes significantly up-regulated in at least three resistant cell lines, meanwhile they did not down-regulate in the other resistant cell lines as candidate genes. Candidate genes were then ranked according to the frequencies of significant up-regulation in resistant cell lines, defining genes with the highest rankings as paclitaxel resistance-related genes (PRGs). Patients were grouped based on the median expression of PRGs. The lipid metabolism-related gene set and the oncological gene set were established and took intersections with genes co-upregulated with PRGs, obtaining 229 co-upregulated genes associated with lipid metabolism and tumorigenesis. The PPI network obtained 19 highly confidential synergistic targets (interaction score > 0.7) that directly associated with CPT1A. Finally, FASN and SCD were up-stream substrate provider and competitor of CPT1A, respectively. Western blot and qRT-PCR results confirmed the over-expression of CPT1A, SCD and FASN in the A2780/PTX cell line. The inhibition of CPT1A, SCD and FASN down-regulated cell viability and migration, pharmacological blockade of CPT1A and SCD increased apoptosis rate and paclitaxel sensitivity of A2780/PTX. In summary, our novel bioinformatic methods can overcome difficulties in drug resistance evaluation, providing promising therapeutical strategies for paclitaxel-resistant EOC via taregting lipid metabolism-related enzymes.

Hypoxia-induced SKA3 promoted cholangiocarcinoma progression and chemoresistance by enhancing fatty acid synthesis via the regulation of PAR-dependent HIF-1a deubiquitylation

BACKGROUND

Spindle and kinetochore-associated complex subunit 3 (SKA3) plays an important role in cell proliferation by regulating the separation of chromosomes and their division into daughter cells. Previous studies demonstrated that SKA3 was strongly implicated in tumor development and progression. However, the roles of SKA3 in cholangiocarcinoma (CCA) and the underlying mechanisms remain unclear.

METHODS

Next-generation sequencing (NGS) was performed with paired CCA tissues and normal adjacent tissues (NATs). SKA3 was chose to be the target gene because of its remarkably upregulation and unknown function in cholangiocarcinoma in TCGA datasets, GSE107943 datasets and our sequencing results. RT-PCR and immunohistochemistry staining were used to detect the expression of SKA3 in paired CCA tissues and normal adjacent tissues. The SKA3 knockdown and overexpression cell line were constructed by small interfering RNA and lentivirus vector transfection. The effect of SKA3 on the proliferation of cholangiocarcinoma under hypoxic conditions was detected by experiments in vitro and in vivo. RNA-seq was used to find out the differentially expressed pathways in cholangiocarcinoma proliferation under hypoxia regulated by SKA3. IP/MS analysis and Western blot assays were used to explore the specific mechanism of SKA3 in regulating the expression of HIF-1a under hypoxia.

RESULTS

SKA3 was up-regulated in NGS, TCGA and GSE107943 databases and was associated with poor prognosis. Functional experiments in vitro and in vivo showed that hypoxia-induced SKA3 promoted cholangiocarcinoma cell proliferation. RNA-sequencing was performed and verified that SKA3 enhanced fatty acid synthesis by up-regulating the expression of key fatty acid synthase, thus promoting cholangiocarcinoma cell proliferation under hypoxic conditions. Further studies indicated that under hypoxic conditions, SKA3 recruited PARP1 to bind to HIF-1a, thus enhancing the poly ADP-ribosylation (PARylation) of HIF-1a. This PARylation enhanced the binding between HIF-1a and USP7, which triggered the deubiquitylation of HIF-1a under hypoxic conditions. Additionally, PARP1 and HIF-1a were upregulated in CCA and promoted CCA cell proliferation. SKA3 promoted CCA cell proliferation and fatty acid synthesis via the PARP1/HIF-1a axis under hypoxic conditions. High SKA3 and HIF-1a expression levels were associated with poor prognosis after surgery.

CONCLUSION

Hypoxia-induced SKA3 promoted CCA progression by enhancing fatty acid synthesis via the regulation of PARylation-dependent HIF-1a deubiquitylation. Furthermore, increased SKA3 level enhanced chemotherapy-resistance to gemcitabine-based regimen under hypoxic conditions. SKA3 and HIF-1a could be potential oncogenes and significant biomarkers for the analysis of CCA patient prognosis.

β-Sitosterol Suppresses Lipopolysaccharide-Induced Inflammation and Lipogenesis Disorder in Bovine Mammary Epithelial Cells

β-sitosterol, a natural plant steroid, has been shown to promote anti-inflammatory and antioxidant activities in the body. In this study, β-sitosterol was used to protect against lipopolysaccharide (LPS)-induced cell damage in bovine mammary epithelial cells, which are commonly studied as a cell model of mammary inflammatory response and lipogenesis. Results showed that treatment with a combination of LPS and β-sitosterol significantly reduced oxidative stress and inflammation, while increasing the expression of anti-apoptotic proteins and activating the hypoxia-inducible factor-1(HIF-1α)/mammalian target of rapamycin(mTOR) signaling pathway to inhibit apoptosis and improve lipid synthesis-related gene expression. Our finding suggests that β-sitosterol has the potential to alleviate inflammation in the mammary gland.

Metabolic reprogramming in cancer: Mechanisms and therapeutics

Cancer cells characterized by uncontrolled growth and proliferation require altered metabolic processes to maintain this characteristic. Metabolic reprogramming is a process mediated by various factors, including oncogenes, tumor suppressor genes, changes in growth factors, and tumor–host cell interactions, which help to meet the needs of cancer cell anabolism and promote tumor development. Metabolic reprogramming in tumor cells is dynamically variable, depending on the tumor type and microenvironment, and reprogramming involves multiple metabolic pathways. These metabolic pathways have complex mechanisms and involve the coordination of various signaling molecules, proteins, and enzymes, which increases the resistance of tumor cells to traditional antitumor therapies. With the development of cancer therapies, metabolic reprogramming has been recognized as a new therapeutic target for metabolic changes in tumor cells. Therefore, understanding how multiple metabolic pathways in cancer cells change can provide a reference for the development of new therapies for tumor treatment. Here, we systemically reviewed the metabolic changes and their alteration factors, together with the current tumor regulation treatments and other possible treatments that are still under investigation. Continuous efforts are needed to further explore the mechanism of cancer metabolism reprogramming and corresponding metabolic treatments.

Coffee peel extracts ameliorate non-alcoholic fatty liver disease via a fibroblast growth factor 21-adiponectin signaling pathway

Coffee peel (CP) contains abundant phytochemicals which might prevent non-alcoholic fatty liver disease (NAFLD). The present study aimed to identify the main phytochemicals in CP extracts, and to investigate whether CP extracts could ameliorate NAFLD through a hepatic fibroblast growth factor (FGF) 21-adiponectin signaling pathway. Caffeine and seven monomers of flavonoids were identified from CP extracts by using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). After 8 weeks of intervention, the mice fed a high-fat and high-sugar diet showed the pathophysiological characteristics of NAFLD. Treatment with CP extracts significantly alleviated hepatic steatosis and insulin resistance and reduced the concentrations of serum alanine transaminase, FGF21, and triglyceride, and hepatic interleukin-6, interleukin-1β, and tumor necrosis factor-α, while increasing serum adiponectin concentrations. Meanwhile, CP extract supplementation significantly decreased the gene and protein expression levels of FGF21, while enhancing adiponectin expression levels. The present study demonstrated that CP extracts contained caffeine and seven monomers of flavonoids, and protected against NAFLD through regulating the FGF21-adiponectin signaling pathway.

The Role of Lipid Metabolism in Gastric Cancer

Gastric cancer has been one of the most common cancers worldwide with extensive metastasis and high mortality. Chemotherapy has been found as a main treatment for metastatic gastric cancer, whereas drug resistance limits the effectiveness of chemotherapy and leads to treatment failure. Chemotherapy resistance in gastric cancer has a complex and multifactorial mechanism, among which lipid metabolism plays a vital role. Increased synthesis of new lipids or uptake of exogenous lipids can facilitate the rapid growth of cancer cells and tumor formation. Lipids form the structural basis of biofilms while serving as signal molecules and energy sources. It is noteworthy that lipid metabolism is capable of inducing drug resistance in gastric cancer cells by reshaping the tumor micro-environment. In this study, new mechanisms of lipid metabolism in gastric cancer and the metabolic pathways correlated with chemotherapy resistance are reviewed. In particular, we discuss the effects of lipid metabolism on autophagy, biomarkers treatment and drug resistance in gastric cancer from the perspective of lipid metabolism. In brief, new insights can be gained into the development of promising therapies through an in-depth investigation of the mechanism of lipid metabolism reprogramming and resensitization to chemotherapy in gastric cancer cells, and scientific treatment can be provided by applying lipid-key enzyme inhibitors as cancer chemical sensitizers in clinical settings.

Key Molecules of Fatty Acid Metabolism in Gastric Cancer

Fatty acid metabolism is closely linked to the progression of gastric cancer (GC), a very aggressive and life-threatening tumor. This study examines linked molecules, such as Sterol Regulatory Element-Binding Protein 1 (SREBP1), ATP Citrate Lyase (ACLY), Acetyl-CoA Synthases (ACSs), Acetyl-CoA Carboxylase (ACC), Fatty Acid Synthase (FASN), Stearoyl-CoA Desaturase 1 (SCD1), CD36, Fatty Acid Binding Proteins (FABPs), and Carnitine palmitoyltransferase 1 (CPT1), as well as their latest studies and findings in gastric cancer to unveil its core mechanism. The major enzymes of fatty acid de novo synthesis are ACLY, ACSs, ACC, FASN, and SCD1, while SREBP1 is the upstream molecule of fatty acid anabolism. Fatty acid absorption is mediated by CD36 and FABPs, and fatty acid catabolism is mediated by CPT1. If at all possible, we will discover novel links between fatty acid metabolism and a prospective gastric cancer target.

CircWHSC1 Promotes Breast Cancer Progression by Regulating the FASN/AMPK/mTOR Axis Through Sponging miR-195-5p

Numerous studies reveal that circular RNAs (circRNAs) affect cancer progression. CircWHSC1 is a novel circRNA that accelerates ovarian cancer progression. Nevertheless, the function of circWHSC1 in regulating breast cancer (BC) is elusive. Here, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was carried out to detect the profiles of circWHSC1 and miR-195-5p in BC tissues and corresponding non-tumor tissues. Gain- and loss-of-function assays were implemented both in vivo and ex vivo to verify the significance of circWHSC1 in BC development. BC cell proliferation was estimated by the cell counting kit-8 (CCK-8) and BrdU assays. Transwell assay was implemented to test BC cell migration and invasion. The protein levels of FASN, AMPK and mTOR were determined by Western blot. Moreover, immunohistochemistry was performed to examine Ki67 and FASN expression. As shown by the result, circWHSC1 was up-regulated in BC tissues versus adjacent non-tumor tissues. circWHSC1 overexpression was correlated with higher tumor stages, lymphatic metastasis and worse survival of BC patients. Functionally, overexpressing circWHSC1 amplified proliferation, migration and invasion of BC cell lines and boosted xenograft tumor growth in nude mice. Bioinformatics uncovered that circWHSC1 functioned as a competitive endogenous RNA by sponging miR-195-5p, which was further corroborated by the dual-luciferase reporter assay and RNA immunoprecipitation. miR-195-5p delayed BC progression, which was dampened by circWHSC1 up-regulation. Fatty acid synthase (FASN) was affirmed as a direct target of miR-195-5p. miR-195-5p overexpression curbed FASN expression and activated its downstream AMPK pathway. Inhibition of FASN or activation of the AMPK pathway reversed circWHSC1-mediated oncogenic effects. Collectively, CircWHSC1 acted as an oncogene to expedite BC evolvement by modulating the miR-195-5p/FASN/AMPK/mTOR pathway.

Beta-Sitosterol Promotes Milk Protein and Fat Syntheses-Related Genes in Bovine Mammary Epithelial Cells

Simple Summary

The levels of milk fats and proteins are important indexes used to evaluate milk quality. Generally, feed additives are used to improve milk quality. This study aimed to investigate the effect of β-sitosterol on milk fat and protein gene expression in bovine mammary epithelial cells. β-sitosterol increased the β-casein levels in bovine mammary epithelial cells and promoted the expression of milk fat and protein synthesis-related genes, suggesting the use of β-sitosterol as a potential feed additive to improve milk quality in dairy cows.

Abstract

β-sitosterol, a phytosterol with multiple biological activities, has been used in the pharmaceutical industry. However, there are only a few reports on the use of β-sitosterol in improving milk synthesis in dairy cows. This study aimed to investigate the effects of β-sitosterol on milk fat and protein syntheses in bovine mammary epithelial cells (MAC-T) and its regulatory mechanism. MAC-T cells were treated with different concentrations (0.01, 0.1, 1, 5, 10, 20, 30, or 40 μM) of β-sitosterol, and the expression levels of milk protein and fat synthesis-related genes and proteins were analyzed. β-sitosterol at 0.1, 1, and 10 μM concentrations promoted the mRNA and protein expression of β-casein. β-sitosterol (0.1, 1, 10 μM) increased the mRNA and protein expression levels of signal transducer activator of transcription 5 (STAT5), mammalian target of rapamycin (mTOR), and ribosomal protein S6 kinase beta-1 (S6K1) of the JAK2/STAT5 and mTOR signaling pathways. It also stimulated the milk fat synthesis-related factors, including sterol regulatory element-binding protein 1 (SREBP1), peroxisome proliferator-activated receptor-gamma (PPARγ), acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), and stearyl CoA desaturase (SCD). β-sitosterol (0.1, 1, 10 μM) also significantly increased the expression of growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and hypoxia-inducible factor-1α (HIF-1α)-related genes. Notably, the compound inhibited the expression of the negative regulator, the suppressor of cytokine signaling 2 (SOCS2) at the two lower concentrations (0.1, 1 μM), but significantly promoted the expression at the highest concentration (30 μM). These results highlight the role of β-sitosterol at concentrations ranging from 0.1 to 10 μM in improving milk protein and fat syntheses, regulating milk quality. Therefore, β-sitosterol can be used as a potential feed additive to improve milk quality in dairy cows.

FASN Knockdown Inhibited Anoikis Resistance of Gastric Cancer Cells via P-ERK1/2/Bcl-xL Pathway

Anoikis resistance (AR) is a crucial step in tumor metastasis. The overexpression of fatty acid synthase (FASN) is not only related to the AR of osteosarcoma cells, but also evidenced on gastric cancer (GC). This study investigated the role of FASN in the AR of GC cells. Plates coated with poly-HEMA were used for the culture of cells with AR. Small interfering RNA targeting FASN (siFASN) was transfected into MNK-45 and AGS cells. The number and apoptosis of cells were assessed by a hemacytometer and Annexin-V-FITC/PI assay, respectively. Aggregated cells and colony numbers were manually counted under a microscope. The migration and invasion rates were measured via wound healing and Transwell invasion assays, respectively. The levels of FASN, phosphorylated (p)-ERK1/2, ERK1/2 and Bcl-xL were detected through western blot or quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The results showed that the cell numbers of MNK-45 and AGS were increased while that of GES-1 cell was decreased during the culture in suspension. A higher apoptosis rate and a smaller number of aggregated cells were observed in GES-1 cells in comparison with MNK-45 and AGS cells. A larger colony number, greater migration and invasion rates, and higher mRNA and protein expressions of FASN were presented in the AR group compared with the control group. Cells transfected with siFASN possessed lower migration and invasion rates, reduced expressions of FASN mRNA and protein, p-ERK1/2 and Bcl-xL, and induced a significantly declined ratio of p-ERK1/2 to ERK1/2. These findings suggest that down-regulation of FASN suppresses the AR of GC cells, which may be related to the inhibition of p-ERK1/2/Bcl-xL pathway.

Pyruvate carboxylase promotes thyroid cancer aggressiveness through fatty acid synthesis

Background

Pyruvate carboxylase (PC) is an important anaplerotic enzyme in the tricarboxylic acid cycle (TCA) in cancer cells. Although PC overexpression has been observed in thyroid cancer (TC), the mechanisms involved in the carcinogenic effects of PC are still unclear.

Methods

Bioinformatics analysis and clinical specimens were used to analyze the relationship of PC expression with clinicopathological variables in TC. Fatty acid synthesis was monitored by LC/MS, Nile red staining, and triglyceride analysis. Mitochondrial oxygen consumption was evaluated by the Seahorse XF Mito Cell Stress Test. The correlation of PC with FASN and SREBP1c was assessed by qRT-PCR and IHC in 38 human TC tissues. Western blotting was used to evaluate the protein expression of PC, FASN, and SREBP1c and members of the AKT/mTOR and EMT pathways in TC cell lines. Wound-healing, CCK-8, and Transwell assays and a nude mouse xenograft model were used to verify the regulatory effects of PC and SREBP1c on thyroid tumor cell proliferation, migration and invasion.

Results

We demonstrated that PC increased fatty acid synthesis, which then promoted TC progression and metastasis. Analysis of GEO data showed that the overexpression of PC in papillary thyroid cancer (PTC) was associated with PTC invasion and the fatty acid synthesis pathway. Analysis of clinical tissue specimens from PTC patients revealed that PC was more highly expressed in specimens from PTC patients with lymph node metastasis than in those from patients without metastasis. Multiple genes in the fatty acid synthesis signaling pathway, including FASN and SREBP1c, were downregulated in PC-knockdown TC cells compared to control cells. Lipid levels were also decreased in the PC-knockdown TC cells. Moreover, the ability of cells to grow, invade, and metastasize was also suppressed upon PC knockdown, suggesting that PC-mediated lipogenesis activation increases the aggressiveness of TC cells. In addition, PC was found to activate the AKT/mTOR pathway, thus improving FASN-mediated de novo lipogenesis in TC cells by upregulating SREBP1c expression. Studies in a nude mouse xenograft model showed that PC knockdown decreased tumor weight, but this effect was attenuated by forced expression of SREBP1c.

Conclusions

Our results demonstrate that PC is strongly involved in the tumor aggressiveness of TC via its stimulation of fatty acid synthesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08499-9.

Analysis of Gastric Cancer Transcriptome Allows the Identification of Histotype Specific Molecular Signatures With Prognostic Potential

Gastric cancer is the fifth most common malignancy but the third leading cause of cancer-associated mortality worldwide. Therapy for gastric cancer remain largely suboptimal making the identification of novel therapeutic targets an urgent medical need. In the present study we have carried out a high-throughput sequencing of transcriptome expression in patients with gastric cancers. Twenty-four patients, among a series of 53, who underwent an attempt of curative surgery for gastric cancers in a single center, were enrolled. Patients were sub-grouped according to their histopathology into diffuse and intestinal types, and the transcriptome of the two subgroups assessed by RNAseq analysis and compared to the normal gastric mucosa. The results of this investigation demonstrated that the two histopathology phenotypes express two different patterns of gene expression. A total of 2,064 transcripts were differentially expressed between neoplastic and non-neoplastic tissues: 772 were specific for the intestinal type and 407 for the diffuse type. Only 885 transcripts were simultaneously differentially expressed by both tumors. The per pathway analysis demonstrated an enrichment of extracellular matrix and immune dysfunction in the intestinal type including CXCR2, CXCR1, FPR2, CARD14, EFNA2, AQ9, TRIP13, KLK11 and GHRL. At the univariate analysis reduced levels AQP9 was found to be a negative predictor of 4 years survival. In the diffuse type low levels CXCR2 and high levels of CARD14 mRNA were negative predictors of 4 years survival. In summary, we have identified a group of genes differentially regulated in the intestinal and diffuse histotypes of gastric cancers with AQP9, CARD14 and CXCR2 impacting on patients' prognosis, although CXCR2 is the only factor independently impacting overall survival.

Downregulation of fatty acid oxidation by involvement of HIF-1α and PPARγ in human gastric adenocarcinoma and related clinical significance

Lipid metabolism rewiring in gastric adenocarcinoma (GA) pathogenesis is still not clearly elucidated. This study aimed to describe the role of lipid catabolism in GA patient outcomes and possible therapeutic targets by analyzing the effect of hypoxia-inducible factor-1α (HIF-1α) on fatty acid oxidation (FAO). AGS cell line was cultured in normoxic and hypoxic conditions, and FAO-related genes were analyzed by real-time-PCR and Western-blot. The study group comprised 108 newly diagnosed GA patients and 152 control cases. Serum concentrations of medium and long-chain acyl-CoA dehydrogenases (MCAD and LCAD) proteins were measured using ELISA, and local expression of HIF-1α, carnitine palmitoyl transferase 1 (CPT1A) and peroxisome proliferator-activated receptor γ (PPARγ) was evaluated by immunohistochemistry. In addition, gene expression of PPARγ, CPT1A, LCAD, and MCAD was assessed by real-time-PCR. In vitro findings indicate HIF-1α upregulation and FAO-related genes and proteins reduction in the hypoxic culture of AGS cells. GA patients had significantly lower circulating levels of LCAD compared to controls. Higher protein expression of HIF-1α and downregulated CPT1A and PPARγ were observed in GA tissues versus controls. Gene expression of CPT1A, PPARγ, LCAD, and MCAD were repressed in GA tissues compared to controls. Moreover, reduced expression of CPT1A, PPARγ, and MCAD were correlated with HIF-1α upregulation in GA. Poor patient outcome was associated with lower PPARγ and LCAD expression in GA. HIF-1α upregulation in human GA patients and AGS cells was paralleled by downregulation of lipid catabolism genes potentially via reduced PPARγ-mediated FAO. This metabolic adaptation to hypoxic condition may play a role in GA pathogenesis and might have clinical and therapeutic value in GA patients.

Tumor Decelerating and Chemo-Potentiating Action of Methyl Jasmonate on a T Cell Lymphoma In Vivo: Role of Altered Regulation of Metabolism, Cell Survival, Drug Resistance, and Intratumoral Blood Flow

Methyl jasmonate (MJ), a natural oxylipin, possesses a broad spectrum of antineoplastic potential in vitro. However, its tumor growth impeding and chemo-potentiating action has not been adequately investigated in vivo. Using a murine thymus-derived tumor named Dalton’s Lymphoma (DL), in the present study, we examined if intra-tumoral administration of MJ can cause tumor growth impedance. We also explored the associated molecular mechanisms governing cell survival, carbohydrate & lipid metabolism, chemo-potentiation, and angiogenesis. MJ administration to tumor-transplanted mice caused deceleration of tumor growth accompanying prolonged survival of the tumor-bearing mice. MJ-dependent tumor growth retardation was associated with the declined blood supply in tumor milieu, cell cycle arrest, augmented induction of apoptosis and necrosis, deregulated glucose and lipid metabolism, enhanced membrane fragility of tumor cells, and altered cytokine repertoire in the tumor microenvironment. MJ administration modulated molecular network implicating Hsp70, Bcl-2, TERT, p53, Cyt c, BAX, GLUT-1, HK 2, LDH A, PDK-1, HIF-1α, ROS, MCT-1, FASN, ACSS2, SREBP1c, VEGF, cytokine repertoire, and MDR1, involved in the regulation of cell survival, carbohydrate and fatty acid metabolism, pH homeostasis, and drug resistance. Thus, the present study unveils novel molecular mechanisms of the tumor growth decelerating action of MJ. Besides, this preclinical study also establishes the adjunct therapeutic potential of MJ. Hence, the present investigation will help to design novel anti-cancer therapeutic regimens for the treatment of hematological malignancies.

Upregulation of fatty acid synthase in MYC and BCL-2 double-expressor lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common and heterogeneous lymphoid malignancy. The subtype with MYC and BCL-2 double-expressor lymphoma (DEL) was defined by its aggressive nature and poor survival outcome. Therefore, the development of effective therapies for the DEL subtype is imperative. Fatty acid synthase (FASN) activity is associated with altered lipid metabolism and aberrant protein translation in DLBCL. However, the inter-regulation of these key processes is not fully determined in DEL. In the present study, the clinical and biological impact of FASN was investigated in the DEL subtype. Initially, FASN expression levels were analyzed from a patient cohort and the data indicated that the highest FASN expression was noted in DEL tissues compared with that noted in the DLBCL and reactive lymphoid hyperplasia tissues. Patients with DEL with combined high-FASN expression indicated poorer EFS outcomes than the rest of the patients. In vitro data indicated that FASN was overexpressed in SU-DHL-2 and U2932 cells. Silencing FASN decreased cell growth and promoted cell apoptosis by modulating the pERK/BCL-2 signaling pathway. In conclusion, the present study indicated that FASN was overexpressed in DEL and that its expression was associated with poor survival outcomes. Furthermore, the data demonstrated that FASN regulated the biological function via the pERK/BCL-2 signaling pathway. FASN serves a critical role in the progression of DEL and its expression may be associated with the development to a more aggressive phenotype of DLBCL. Therefore, it may be considered a potential therapeutic target for DLBCL.

iTRAQ-based proteomic analysis of the molecular mechanisms and downstream effects of fatty acid synthase in osteosarcoma cells

Background

Fatty acid synthase (FASN) is a lipogenic enzyme that participates in tumor progression. We previously showed that FASN is dysregulated in OS malignancy, but the molecular mechanism(s) of these effects remained unclear.

Methods

We examined differentially expressed proteins (DEPs) in FASN‐silenced osteosarcoma 143B cells and their parental cells by isobaric tags for relative and absolute quantitation (iTRAQ). Differentially expressed proteins were classified using GO and KEGG analysis. The association between FASN and heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) was confirmed using qPCR, Western blot, and immunohistochemistry. The function of HNRNPA1 in osteosarcoma was determined using CCK‐8, colony formation, wound healing, transwell migration, and invasion assays.

Results

Among the 4971 identified proteins, 567 DEPs (325 upregulated and 242 downregulated) were identified. The top 10 upregulated proteins comprised HIST1H2AB, INA, INTS5, MTCH2, EIF1, MAPK1IP1L, PXK, RPS27, PM20D2, and ZNF800, while the top 10 downregulated proteins comprised NDRG1, CNTLN, STON2, GDF7, HECTD3, HBB, TPM1, PPP4R4, PTTG1IP, and PLCB3. Bioinformatic analysis indicated that the DEPs were related to cellular processes, metabolic processes, biological regulation, binding, and catalytic activity. HNRNPA1 was dysregulated in FASN‐silenced 143B and HOS cells. qPCR, Western blot, and immunohistochemistry showed that FASN expression positively correlates with HNRNPA1 expression. Further studies indicated that HNRNPA1 correlates with OS diagnosis and prognosis. And HNRNPA1 silence inhibits the proliferation, migration, and invasion in OS cells.

Conclusion

HNRNPA1 acts as targets downstream of FASN and potential biomarker and oncogene in OS.

Epidemiologic Study of Gastric Cancer in Iran: A Systematic Review

BACKGROUND

Gastric cancer (GC) is one of the most common cancers in Iran. Knowledge of the epidemiology of the disease is essential in planning for prevention. So this study aimed to investigate the epidemiological aspects of gastric cancer including prevalence, incidence, mortality, and risk factors of Iran.

METHODS

This systematic review study was based on articles published in both English and Persian languages during the years of 1970-2020 in international databases (PubMed, Web of Science, Scopus) and national databases (including SID, Magiran, and IranDoc). Papers related to epidemiological aspects of the disease including mortality, prevalence, incidence, and risk entered the final review.

RESULTS

According to the studies, the minimum and maximum prevalence of gastric cancer in northwestern Iran (Ardabil) is between 0.2 and 100 per 100,000. Also, the death rate per 100,000 people ranged from 10.6 to 15.72 and the ASMR ranged from 4.2 to 32.2%. On the other hand, the incidence of GC was higher in men than in women (74.9 vs 4.6%). The GC risk ratio was 8-times higher in the elderly than in the other age groups (HR=8.0, 2.7-23.5). The incidence of gastric cancer in patients with H. pylori infection was 18-times and that of smokers 2-times higher than other populations. Low level of economic situation and food insecurity increased the odds of GC by 2.42- and 2.57-times, respectively. It should be noted that there was a direct relationship between consumption of processed red meat, dairy products, fruit juice, smoked and salty fish and legumes, strong and hot tea, and consumption of salt and gastric cancer incidence. There was also an inverse relationship between citrus consumption, fresh fruit, garlic, and gastric cancer. In addition, the mRNA genes are the most GC-related genes.

CONCLUSION

Given the high incidence of GC in Iran, changing lifestyle and decreasing consumption of preservatives in food, increasing consumption of fruits and vegetables, and improving the lifestyle can be effective in reducing the incidence of this disease.

Deregulation of Lipid Metabolism: The Critical Factors in Ovarian Cancer

Ovarian cancer is one of the most malignant gynecological cancers around the world. In spite of multiple treatment options, the five-year survival rate is still very low. Several metabolism alterations are described as a hallmark in cancers, but alterations of lipid metabolism in ovarian cancer have been paid less attention. To explore new markers/targets for accurate diagnosis, prognosis, and therapeutic treatments based on metabolic enzyme inhibitors, here, we reviewed available literature and summarized several key metabolic enzymes in lipid metabolism of ovarian cancer. In this review, the rate limiting enzymes associated with fatty acid synthesis (FASN, ACC, ACLY, SCD), the lipid degradation related enzymes (MAGL, CPT, 5-LO, COX2), and the receptors related to lipid uptake (FABP4, CD36, LDLR), which promote the development of ovarian cancer, were analyzed and evaluated. We also focused on the review of application of current metabolic enzyme inhibitors for the treatment of ovarian cancer through which the potential therapeutic agents may be developed for ovarian cancer therapy.

Expression and prognostic significance of fatty acid synthase in clear cell renal cell carcinoma

Fatty acid synthase (FASN), a key enzyme essential for fatty acid (FA) synthesis, was reportedly implicated in the initiation and progression of various cancers. However, the clinical significance of FASN in renal cell carcinoma (RCC) has not been fully elucidated yet. Here we compare the expression profile and evaluate the prognostic significance of FASN in clear cell RCC (ccRCC) patients. FASN expression was examined in 3 pairs ccRCC and their adjacent nontumor tissues by western blotting (WB) analysis, and its expression was assessed in 145 ccRCC and 13 nontumor tissues by immunohistochemistry (IHC) analysis with tissue microarrays (TMAs). The prognosis of FASN was further investigated in large-scale database using LinkedOmics (n = 537) and The Cancer Protein Atlas (TCPA, n = 445), respectively. WB detected higher FASN expression in ccRCC than normal tissues, then IHC analysis revealed that FASN expression was positively associated with histological grade, pathological stage, tumor size and metastasis status, and negatively associated with cancer-specific survival (CSS). Univariate survival analysis demonstrated that high grade, advanced stage, large tumor, metastasis, and high FASN expression were significantly associated with a shorter CSS, and multivariate analysis revealed tumor grade, stage, metastasis and FASN were identified as independent predictors for CSS in patients with ccRCC. Further LinkedOmics and TCPA analyses confirmed that high FASN expression was correlated with a poorer overall survival (OS) of ccRCC. Collectively, these findings demonstrated FASN could be a poor prognostic factor in ccRCC patients, which indicated that FA synthesis might be implicated in the tumorigenesis and progression of ccRCC.

Fatty acid synthase is a prognostic marker and associated with immune infiltrating in gastric cancers precision medicine

Aim: Fatty acid synthase (FASN), a key enzyme for de novo synthesis of fatty acids, has been identified as an oncogene in some tumor types; however, the function of FASN in gastric cancer (GC) is poorly elucidated. Method: Integrative bioinformatics analyses were performed to unveil the role of FASN in tumor progression and cancer-associated immunology of GC. Result: FASN was overexpressed in the GC tissues and correlated with an inferior survival outcome, and largely contributed to the carcinogenesis of GC. Moreover, FASN expression was closely associated with the immune-infiltrating levels of CD8⁺ T, CD4⁺ T, neutrophils, macrophages and dendritic cells. Conclusion: FASN was closely associated with GC and may be involved in the tumorigenesis and cancer-immune interactions, and could be a promising prognostic and therapeutic biomarker in GC.