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CPT1A knockdown decreases anchorage-independent growth and in vivo aggressiveness of ovarian cancer cells. ( A ) Colony formation assay in soft agar was performed in CPT1A knockdown and control SKOV-3, OVCA-432 and OVCAR-3 cells. Microphotographs covering representative areas of each treatment were shown ( left ). Numbers of colonies (> 0.2 mm in diameter) in each well of 6-well plates were quantified ( right) . ( B ) CPT1A knockdown and control SKOV-3, OVCA-432 and OVCAR-3 cells were injected s.c. on the right flank of SCID mice. Growth curves were constructed from tumor volumes (mean ± S.D.) measured at indicated times (days) post cell injection ( upper ). Tumors of each group were removed and photographed after sacrifice of animals ( middle ). Shown in lower panel were tumor volumes at endpoints with volumes of those grown from ctrl-sh cells defined as 100%. Statistical significances of differences between ctrl-sh xenografts and CPT1A-sh1 or CPT1A-sh2 xenografts were determined with the Student’s t- test. ( C ) CPT1A-sh2 knockdown and control SKOV-3 cells were i.p. injected into SCID mice (6/group). Kaplan Meier survival and the LogRank test of two groups were performed using SigmaPlot 13.0.
Source publication
Cancer cells rely on hyperactive de novo lipid synthesis for maintaining malignancy. Recent studies suggest involvement in cancer of fatty acid oxidation, a process functionally opposite to lipogenesis. A mechanistic link from lipid catabolism to oncogenic processes is yet to be established. Carnitine palmitoyltransferase 1 (CPT1) is a rate-limitin...
Contexts in source publication
Context 1
... a week after infection of SKOV-3, OVCA- 432 and OVCAR-3 with CPT1A shRNA lentivirus, subpopulations of cells showed morphological appearances of senescence (Supplementary Figure S4). We performed staining for β-galactosidase (β-gal) activity, a biomarker of cellular senescence [24]. ...
Context 2
... early emerging, morphologically distinct cells were stained positive for β-gal. Similarly, treatment with etomoxir for 3 days also increased numbers of β-gal-positive and morphologically flattened cells (Supplementary Figure S4). However, β-gal-positive cells were not detectable in Caov-3 following CPT1A-shRNA knockdown or treatment with etomoxir (data not shown). ...
Context 3
... knockdown inhibited proliferation of ovarian cancer cells not only in monolayer culture ( Figure 2A) but also in soft agar ( Figure 4A). We focused on SKOV-3, OVCA-432, and OVCAR-3 cells based on their reported abilities to grow in anchorage- independent conditions and to form xenografts in mice [25,26]. ...
Context 4
... next examined the effect of shRNA knockdown on tumorigenicity of these cells in SCID mice. CPT1A- sh2 knockdown also strongly inhibited initiation and enlargement of subcutaneous xenografts in SCID mice as reflected by their growth curves ( Figure 4B). Consistent with this, mice intraperitoneally (i.p.) injected with CPT1A-sh2 knockdown SKOV-3 cells survived significantly longer than those injected with control cells as indicated by Kaplan Meier survival analysis ( Figure 4C). ...
Context 5
... sh2 knockdown also strongly inhibited initiation and enlargement of subcutaneous xenografts in SCID mice as reflected by their growth curves ( Figure 4B). Consistent with this, mice intraperitoneally (i.p.) injected with CPT1A-sh2 knockdown SKOV-3 cells survived significantly longer than those injected with control cells as indicated by Kaplan Meier survival analysis ( Figure 4C). ...
Citations
... Prostate cancer cells use β-oxidation of fatty acids as their main energy source [50], and ACSL1 promotes prostate cancer progression by increasing lipogenesis and FAO [51]. CPT1A is highly expressed in ovarian cancer and upregulated FAO mediated by CPT1A to promote ovarian cancer progression [52]. CPT1B plays critical roles in maintaining breast cancer cell stemness and enhancing chemoresistance [24]. ...
... Moreover, we observed that only CPT1C was regulated by the core cell machinery, APC/C, whereas CPT1A and CPT1B were not. CPT1A and CPT1B have similar functions, and the results of many studies have shown that FAO is upregulated under normal glucose conditions [24,52,58]. We also found that CPT1C enhanced fatty acid utilization and promoted ESCC cell survival under low-glucose conditions. ...
Background
In addition to functioning as a precise monitoring mechanism in cell cycle, the anaphase-promoting complex/cyclosome (APC/C) is reported to be involved in regulating multiple metabolic processes by facilitating the ubiquitin-mediated degradation of key enzymes. Fatty acid oxidation is a metabolic pathway utilized by tumor cells that is crucial for malignant progression; however, its association with APC/C remains to be explored.
Methods
Cell cycle synchronization, immunoblotting, and propidium iodide staining were performed to investigate the carnitine palmitoyltransferase 1 C (CPT1C) expression manner. Proximity ligation assay and co-immunoprecipitation were performed to detect interactions between CPT1C and APC/C. Flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium, inner salt (MTS) assays, cell-scratch assays, and transwell assays and xenograft transplantation assays were performed to investigate the role of CPT1C in tumor progression in vitro and in vivo. Immunohistochemistry was performed on tumor tissue microarray to evaluate the expression levels of CPT1C and explore its potential clinical value.
Results
We identified CPT1C as a novel APC/C substrate. CPT1C protein levels exhibited cell cycle-dependent fluctuations, peaking at the G1/S boundary. Elevated CPT1C accelerated the G1/S transition, facilitating tumor cell proliferation in vitro and in vivo. Furthermore, CPT1C enhanced fatty acid utilization, upregulated ATP levels, and decreased reactive oxygen species levels, thereby favoring cell survival in a harsh metabolic environment. Clinically, high CPT1C expression correlated with poor survival in patients with esophageal squamous cell carcinoma.
Conclusions
Overall, our results revealed a novel interplay between fatty acid utilization and cell cycle machinery in tumor cells. Additionally, CPT1C promoted tumor cell proliferation and survival by augmenting cellular ATP levels and preserving redox homeostasis, particularly under metabolic stress. Therefore, CPT1C could be an independent prognostic indicator in esophageal squamous cell carcinoma.
... But the OS analysis result was consistent with the result from the TCGA database that the expression of FOXO1 was significantly increased in tumor tissues, which indicated that FOXO1 might play a role of oncogenic gene in LGG. For OV, it has been reported that FOXO1 was ubiquitously expressed in different OV cell lines and knockdown of FOXO1 could inhibit the proliferation of these OV cell lines (15). This finding was consistent with our OS analysis, which indicated that FOXO1 might also play the role of an oncogenic gene in OV. ...
Forkhead Box O1 (FOXO1) has been reported to play important roles in many tumors. However, FOXO1 has not been studied in pan-cancer. The purpose of this study was to reveal the roles of FOXO1 in pan-cancer (33 cancers in this study). Through multiple public platforms, a pan-cancer analysis of FOXO1 was conducted to obtained FOXO1 expression profiles in various tumors to explore the relationship between FOXO1 expression and prognosis of these tumors and to disclose the potential mechanism of FOXO1 in these tumors. FOXO1 was associated with the prognosis of multiple tumors, especially LGG (low grade glioma), OV (ovarian carcinoma), and KIRC (kidney renal clear cell carcinoma). FOXO1 might play the role of an oncogenic gene in LGG and OV, while playing the role of a cancer suppressor gene in KIRC. FOXO1 expression had a significant correlation with the infiltration of some immune cells in LGG, OV, and KIRC. By combining FOXO1 expression and immune cell infiltration, we found that FOXO1 might influence the overall survival of LGG through the infiltration of myeloid dendritic cells or CD4+ T cells. Functional enrichment analysis and gene set enrichment analysis showed that FOXO1 might play roles in tumors through immunoregulatory interactions between a lymphoid and a non-lymphoid cell, TGF-beta signaling pathway, and transcriptional misregulation in cancer. FOXO1 was associated with the prognosis of multiple tumors, especially LGG, OV, and KIRC. In these tumors, FOXO1 might play its role via the regulation of the immune microenvironment.
... Moreover, studies have shown that downregulation of CPT1A activates the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT) pathway [29], which inhibits decidualization [65,66]. Inhibition of CPT1A stimulates phosphorylation of the FoxO transcription factor [67], while the phosphorylation of FoxO1 promotes self-degradation and damages decidualization [68]. ...
Objective
Lipid metabolism plays an important role in early pregnancy, but its effects on decidualization are poorly understood. Fatty acids (FAs) must be esterified by fatty acyl-CoA synthetases to form biologically active acyl-CoA in order to enter the anabolic and/or catabolic pathway. Long-chain acyl-CoA synthetase 4 (ACSL4) is associated with female reproduction. However, whether it is involved in decidualization is unknown.
Methods
The expression of ACSL4 in human and mouse endometrium was detected by immunohistochemistry. ACSL4 levels were regulated by the overexpression of ACSL4 plasmid or ACSL4 siRNA, and the effects of ACSL4 on decidualization markers and morphology of endometrial stromal cells (ESCs) were clarified. A pregnant mouse model was established to determine the effect of ACSL4 on the implantation efficiency of mouse embryos. Modulation of ACSL4 detects lipid anabolism and catabolism.
Results
Through examining the expression level of ACSL4 in human endometrial tissues during proliferative and secretory phases, we found that ACSL4 was highly expressed during the secretory phase. Knockdown of ACSL4 suppressed decidualization and inhibited the mesenchymal-to-epithelial transition induced by MPA and db-cAMP in ESCs. Further, the knockdown of ACSL4 reduced the efficiency of embryo implantation in pregnant mice. Downregulation of ACSL4 inhibited FA β-oxidation and lipid droplet accumulation during decidualization. Interestingly, pharmacological and genetic inhibition of lipid droplet synthesis did not affect FA β-oxidation and decidualization, while the pharmacological and genetic inhibition of FA β-oxidation increased lipid droplet accumulation and inhibited decidualization. In addition, inhibition of β-oxidation was found to attenuate the promotion of decidualization by the upregulation of ACSL4. The decidualization damage caused by ACSL4 knockdown could be reversed by activating β-oxidation.
Conclusions
Our findings suggest that ACSL4 promotes endometrial decidualization by activating the β-oxidation pathway. This study provides interesting insights into our understanding of the mechanisms regulating lipid metabolism during decidualization.
... These isoforms of CPT1 are involved in different diseases such as cardiovascular diseases, metabolic syndrome, diabetes mellitus type 2, neuropsychiatric and neurological diseases and cancer 11,12 . In particular, CPT1A has found to be overexpressed in most ovarian cancer cell lines and primary ovarian serous carcinomas, to correlate with poor overall survival of ovarian cancer patients, and to be upregulated in cells cultured in suspension namely mimicking in vitro anoikis resistance 9,13 . Ovarian cancer cell lines were proven to be dependent on CPT1A mediated fatty acid oxidation for cell cycle progression since the inactivation of CPT1A decreased ATP levels and induced cell cycle arrest at G0/G1, moreover CPT1A deficiency also suppressed anchorage-independent growth 13 . ...
... In particular, CPT1A has found to be overexpressed in most ovarian cancer cell lines and primary ovarian serous carcinomas, to correlate with poor overall survival of ovarian cancer patients, and to be upregulated in cells cultured in suspension namely mimicking in vitro anoikis resistance 9,13 . Ovarian cancer cell lines were proven to be dependent on CPT1A mediated fatty acid oxidation for cell cycle progression since the inactivation of CPT1A decreased ATP levels and induced cell cycle arrest at G0/G1, moreover CPT1A deficiency also suppressed anchorage-independent growth 13 . Therefore, targeting fatty acid oxidation upregulation could be a possible improvement in epithelial ovarian cancer therapy 14 . ...
Amiodarone repositioning in cancer treatment is promising, however toxicity limits seem to arise, constraining its exploitability. Notably, amiodarone has been investigated for the treatment of ovarian cancer, a tumour known for metastasizing within the peritoneal cavity. This is associated with an increase of fatty acid oxidation, which strongly depends on CPT1A, a transport protein which has been found overexpressed in ovarian cancer. Amiodarone is an inhibitor of CPT1A but its role still has to be explored. Therefore, in the present study, amiodarone was tested on ovarian cancer cell lines with a focus on lipid alteration, confirming its activity. Moreover, considering that drug delivery systems could lower drug side effects, microfluidics was employed for the development of drug delivery systems of amiodarone obtaining simultaneously liposomes with a high payload and amiodarone particles. Prior to amiodarone loading, microfluidics production was optimized in term of temperature and flow rate ratio. Moreover, stability over time of particles was evaluated. In vitro tests confirmed the efficacy of the drug delivery systems.
... At present, emerging evidence has indicated that FAO is a promising target for cancer therapy. For example, some enzymes involved in the regulation of FAO progress are overexpressed in many types of cancers, which could associate strongly with poor outcomes for cancer patients [8,9]. In addition, the activated status of oncoproteins and the active oxidation of fatty acids may interact and promote each other [10,11]. ...
Background
Fatty acid oxidation (FAO) is considered to play a vital part in tumor metabolic reprogramming. But the comprehensive description of FAO dysregulation in tumors has not been unknown.
Methods
We obtained FAO genes, RNA-seq data and clinical information from the Msigdb, TCGA and GTEx databases. We assessed their prognosis value using univariate cox analysis, survival analysis and Kaplan-Meier curve. We determined the function of FAO genes using gene set variation analysis. The correlation analysis was calculated by corrplot R package. Immunotherapy response was assessed through TIDE scores. The protein expression levels of FAO genes were validated using immunohistochemistry (IHC).
Results
The FAO scores were highest in COAD but lowest in PCPG. FAO scores were significantly associated with the prognosis of some cancers in OS, DSS, DFI and PFI. Besides, gene set variation analysis identified that FAO scores were related to immune-related pathways, and immune infiltration analysis showed FAO scores were positively related to cancer-associated fibroblasts and various immune-related genes. TIDE scores were significantly decreased in ACC, CHOL, ESCA, GBM, LAML, SARC, SKCM and THCA compared with normal samples, while it was significantly increased in BLCA, LUAD, LUSC, PCPG, PRAD and STAD. Besides, most FAO genes were downregulated in pan-cancer compared with normal samples. Moreover, we found copy number variation (CNV) of FAO genes played a positive role in their mRNA expression, while methylation was negative. We determined FAO genes were closely related to some drugs in pan-cancer.
Conclusions
FAO score is a novel and promising factor for predicting outcomes.
... Fatty acid oxidation (FAO) is an essential component of fatty acid metabolism. Studies have demonstrated that numerous cancers, such as leukemia [16] and diffuse large B cell lymphoma (DLBCL) [17], rely on FAO as an essential source of ATP [18][19][20] that promotes cells survival [21,22]. Nevertheless, the relationship between FAO and EC as well as the potential related molecular mechanisms are currently unclear and need to be further studied. ...
... Malonyl-CoA levels decrease as acetyl-CoA carboxylase (ACC) is inhibited, and the inhibitory effect of malonyl-CoA on carnitine palmitoyltransferase-1 (CPT1) is weakened as a result. Then, fatty acyl-CoA is converted to acylcarnitine, which enters the mitochondria to promote FAO [5,27] and produces a significant amount of ATP to promote cell survival [18][19][20]. Compared with normal cells, tumor cells not only proliferate faster but also often require more energy. ...
... Notably, CPT1C, which is a pivotal rate-limiting enzyme in FAO that is responsible for fatty acid transport into mitochondria, is implicated in cancer development and progression, highlighting its potential for use as a therapeutic target in the treatment of cancer [27], and upregulation of CPT1C has been confirmed to be capable of accelerating FAO in gastric cancer [40]. The production of abundant levels of ATP is significantly enhanced in response to FAO activation, and this increase in ATP levels enhances a series of abnormal physiological activities, including growth and metastasis, in cancer cells [18][19][20]. Our data are also consistent with these findings: AMPK was activated by ACSL1, and the subsequent increase in CPT1C protein levels was associated with AMPK phosphorylation, indicating that increased ACSL1 levels can enhance malignant progression in EC cells due to the modulation of FAO (Fig. 4). ...
Background:
Gynecological malignancies, such as endometrial cancer (EC) and uterine cancer are prevalent. Increased Acyl-CoA synthetase long-chain family member 1 (ACSL1) activity may contribute to aberrant lipid metabolism, which is a potential factor that contributes to the pathogenesis of endometrial cancer. This study aimed to elucidate the potential molecular mechanisms by which ACSL1 is involved in lipid metabolism in endometrial cancer, providing valuable insights for targeted therapeutic strategies.
Methods:
Xenograft mouse models were used to assess the effect of ACSL1 on the regulation of endometrial cancer progression. ACSL1 protein levels were assessed via immunohistochemistry and immunoblotting analysis. To assess the migratory potential of Ishikawa cells, wound-healing and Transwell invasion assays were performed. Changes in lipids in serum samples from mice with endometrial cancer xenotransplants were examined in an untargeted lipidomic study that combined multivariate statistical methods with liquid chromatography‒mass spectrometry (LC/MS).
Results:
Patient sample and tissue microarray data suggested that higher ACSL1 expression is strongly associated with the malignant progression of EC. Overexpression of ACSL1 enhances fatty acid β-oxidation and 5'-adenylate triphosphate (ATP) generation in EC cells, promoting cell proliferation and migration. Lipidomic analysis revealed that significant changes were induced by ACSL1, including changes to 28 subclasses of lipids and a total of 24,332 distinct lipids that were detected in both positive and negative ion modes. Moreover, pathway analysis revealed the predominant association of these lipid modifications with the AMPK/CPT1C/ATP pathway and fatty acid β-oxidation.
Conclusions:
This study indicates that ACSL1 regulates the AMPK/CPT1C/ATP pathway, which induces fatty acid β-oxidation, promotes proliferation and migration, and then leads to the malignant progression of EC.
... CPT1A has been identified as a potential therapeutic target in OC through multiomic analysis. This is believed to be due to its ability to regulate cell cycle progression by repressing FoxO transcription factors in OC, as demonstrated by Shao 43 . These findings highlight the potential value of CPT1A as a prognostic marker for OC, making it a promising target for further investigation. ...
The aim of this study was to determine the prognostic significance of anoikis related genes (ARGs) in ovarian cancer (OC) and to develop a prognostic signature based on ARG expression. We analyzed cohorts of OC patients and used nonnegative matrix factorization (NMF) for clustering. Single-sample gene-set enrichment analysis (ssGSEA) was employed to quantify immune infiltration. Survival analyses were performed using the Kaplan–Meier method, and differences in survival were determined using the log-rank test. The extent of anoikis modification was quantified using a risk score generated from ARG expression. The analysis of single-cell sequencing data was performed by the Tumor Immune Single Cell Hub (TISCH). Our analyses revealed two distinct patterns of anoikis modification. The risk score was used to evaluate the anoikis modification patterns in individual tumors. Three hub-genes were screened using the LASSO (Least Absolute Shrinkage and Selection Operator) method and patients were classified into different risk groups based on their individual score and the median score. The low-risk subtype was characterized by decreased expression of hub-genes and better overall survival. The risk score, along with patient age and gender, were considered to identify the prognostic signature, which was visualized using a nomogram. Our findings suggest that ARGs may play a novel role in the prognosis of OC. Based on ARG expression, we have developed a prognostic signature for OC that can aid in patient stratification and treatment decision-making. Further studies are needed to validate these results and to explore the underlying mechanisms.
... Overexpression of the CPT1A protein was found to be related to the pathogenicity of diverse diseases. For example, it promotes the progression of ovarian cancer, nasopharyngeal carcinoma (Shao et al., 2016;Tan et al., 2018), and nonalcoholic steatohepatitis (Yang et al., 2021). Accumulating studies have indicated that CPT1A is an attractive therapeutic target for intervention of various diseases (Dai et al., 2018;Schlaepfer and Joshi, 2020). ...
Bovine herpesvirus 1(BoHV-1) is an important bovine pathogen that causes great economic loss to cattle farms worldwide. The virus-productive infection in bovine kidney (MDBK) cells results in ATP depletion. The mechanisms are not well understood. Mitochondrial fatty acid β-oxidation (FAO) is an important energy source in many tissues with high energy demand. Since carnitine palmitoyl-transferase 1 A (CPT1A) is the rate-limiting enzyme of FAO, we investigated the interactions between virus-productive infection and CPT1A signaling. Here, we found that virus-productive infection at the later stage significantly decreased CPT1A protein levels in all the detected cells, including MDBK, A549, and Neuro-2A cells, differentially altered the accumulation of CPT1A proteins in the nucleus and cytosol, and re-localized the protein in the nucleus. Etomoxir (ETO), an irreversible inhibitor of CPT1A, inhibited viral replication and partially interfered with the ability of BoHV-1 to alter CPT1A accumulation in the nucleus but not in the cytosol. Furthermore, ETO consistently reduced RNA levels of two viral regulatory proteins (bICP0 and bICP22) and protein expression of virion-associated proteins during productive infection, further supporting the important roles of CPT1A signaling in BoHV-1 productive infection. These data, for the first time, suggest that CPT1A is potentially involved in BoHV-1 productive infection.
... Previous studies conducted on ovarian cancer cells have reported an association between heightened beta-oxidation activity and the overexpression of Carnitine Palmitoyltransferase I (CPT1), a key enzyme involved in the conversion of long-chain fatty acids into acylcarnitines for transport into the mitochondria [63]. Furthermore, this overexpression has been linked to poorer survival outcomes in ovarian cancer patients [64]. Interestingly, increased reliance on fatty acid metabolism and beta-oxidation has been associated with chemoresistance in numerous clinical screenings [65]. ...
... Fatty acid βoxidation (FAO) is a multistep process that breaks down long-chain fatty acids to acetyl-CoA, which will be fully oxidized through the Krebs cycle and the electron transport chain to produce ATP (13). While FAO is known for its bioenergetic support of cell growth, accumulating evidence shows that FAO is abnormally activated in cancer cells in connection with oncogenes (e.g., c-Myc and c-Src) and contributes to the different aspects of malignancy (13)(14)(15)(16)(17). Additionally, FAO activation has been implicated in cancer resistance to certain chemotherapeutic or endocrinal drugs (18)(19)(20)(21). ...
... Carnitine palmitoyltransferase 1 (CPT1), particularly its liver isoform CPT1A, is the rate-limiting enzyme of FAO in many tissues that catalyzes the transfer of long-chain acyl group of acyl-CoA ester to carnitine, thereby shuttling long-chain fatty acids into the mitochondrial matrix through the carnitine transporter for βoxidation (22). Several studies, including our own, showed that CPT1A-driven FAO can facilitate cancer cell proliferation and survival as well as tumor invasion (15,23,24). In the current study, we examine the role of CPT1A-mediated FAO in murine or human cancer cell response to cytolytic immune cells including CTLs and CAR T cells. ...
... First, murine tumor lines (i.e., melanoma, prostate cancer) lacking CPT1A become highly susceptible to killing by antigen-specific CD8 T cells (i.e., Pmel, OT-I) when compared to their WT counterparts. Although CPT1A downregulation was previously reported to inhibit cancer cell growth (15,23,24), the aggressive growth of tumor models used in our study (i.e., B16, RM1) did not seem to be affected by the CPT1A deletion. Their similar growth rates in culture and in vivo provide us a suitable system that allows reliably measuring their sensitivities to cytotoxic T cells. ...
Although tumor-intrinsic fatty acid β-oxidation (FAO) is implicated in multiple aspects of tumorigenesis and progression, the impact of this metabolic pathway on cancer cell susceptibility to immunotherapy remains unknown. Here, we report that cytotoxicity of killer T cells induces activation of FAO and upregulation of carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme of FAO in cancer cells. The repression of CPT1A activity or expression renders cancer cells more susceptible to destruction by cytotoxic T lymphocytes. Our mechanistic studies reveal that FAO deficiency abrogates the prosurvival signaling in cancer cells under immune cytolytic stress. Furthermore, we identify T cell–derived IFN-γ as a major factor responsible for induction of CPT1A and FAO in an AMPK-dependent manner, indicating a dynamic interplay between immune effector cells and tumor targets. While cancer growth in the absence of CPT1A remains largely unaffected, established tumors upon FAO inhibition become significantly more responsive to cellular immunotherapies including chimeric antigen receptor-engineered human T cells. Together, these findings uncover a mode of cancer resistance and immune editing that can facilitate immune escape and limit the benefits of immunotherapies.
