Acetyl-CoA carboxylase 1 depletion suppresses de novo fatty acid synthesis and mitochondrial β-oxidation in castration-resistant prostate cancer cells

Abstract

Cancer cells, including those of prostate cancer (PCa), often hijack intrinsic cell signaling to reprogram their metabolism. Part of this reprogramming includes the activation of de novo synthesis of fatty acids that not only serve as building blocks for membrane synthesis but also as energy sources for cell proliferation. However, how de novo fatty acid synthesis contributes to PCa progression is still poorly understood. Herein, by mining public datasets, we discovered that the expression of acetyl-CoA carboxylase alpha (ACACA), which encodes acetyl-CoA carboxylase 1 (ACC1), was highly expressed in human PCa. In addition, patients with high ACACA expression had a short disease-free survival time. We also reported that depletion of ACACA reduced de novo fatty acid synthesis and PI3K/AKT signaling in the human castration-resistant PCa (CRPC) cell lines DU145 and PC3. Furthermore, depletion of ACACA downregulates mitochondrial beta-oxidation, resulting in mitochondrial dysfunction, a reduction in ATP production, an imbalanced NADP+/NADPhydrogen(H) ratio, increased reactive oxygen species, and therefore apoptosis. Reduced exogenous fatty acids by depleting lipid or lowering serum supplementation exacerbated both shRNA depletion and pharmacological inhibition of ACACA-induced apoptosis in vitro. Collectively, our results suggest that inhibition of ectopic ACACA, together with suppression of exogenous fatty acid uptake, can be a novel strategy for treating currently incurable CRPC. Cancer cells, including those of prostate cancer (PCa), often hijack intrinsic cell signaling to reprogram their metabolism. Part of this reprogramming includes the activation of de novo synthesis of fatty acids that not only serve as building blocks for membrane synthesis but also as energy sources for cell proliferation. However, how de novo fatty acid synthesis contributes to PCa progression is still poorly understood. Herein, by mining public datasets, we discovered that the expression of acetyl-CoA carboxylase alpha (ACACA), which encodes acetyl-CoA carboxylase 1 (ACC1), was highly expressed in human PCa. In addition, patients with high ACACA expression had a short disease-free survival time. We also reported that depletion of ACACA reduced de novo fatty acid synthesis and PI3K/AKT signaling in the human castration-resistant PCa (CRPC) cell lines DU145 and PC3. Furthermore, depletion of ACACA downregulates mitochondrial beta-oxidation, resulting in mitochondrial dysfunction, a reduction in ATP production, an imbalanced NADP+/NADPhydrogen(H) ratio, increased reactive oxygen species, and therefore apoptosis. Reduced exogenous fatty acids by depleting lipid or lowering serum supplementation exacerbated both shRNA depletion and pharmacological inhibition of ACACA-induced apoptosis in vitro. Collectively, our results suggest that inhibition of ectopic ACACA, together with suppression of exogenous fatty acid uptake, can be a novel strategy for treating currently incurable CRPC. According to the statistics of 36 cancers in 185 countries, the incidence of prostate cancer (PCa) is 14.1% and the mortality rate is 6.8%, which ranks as the second most common and fifth most deadly cancer in men (1Sung H. Ferlay J. Siegel R.L. Laversanne M. Soerjomataram I. Jemal A. et al.Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality Worldwide for 36 cancers in 185 countries.CA. Cancer J. Clin. 2021; 71: 209-249Crossref PubMed Scopus (37605) Google Scholar). The latest released data estimate that nearly 270 thousand cases of PCa will be diagnosed yearly in the United States, ranking PCa the first male cancer incidence and the fifth leading cause of cancer death (2Siegel R.L. Miller K.D. Fuchs H.E. Jemal A. Cancer statistics, 2022.CA. Cancer J. Clin. 2022; 72: 7-33Crossref PubMed Scopus (4971) Google Scholar). At the early stage, PCa is an indolent disease that grows slowly. However, PCa progresses quickly once it enters advanced and symptomized stages. Radical resection with androgen deprivation follow-up therapies is the first-line treatment for PCa. Most PCa eventually progress to metastatic androgen treatment-resistant disease called metastatic castration-resistant PCa (mCRPC) (3Cooperberg M.R. Carroll P.R. Trends in management for patients with localized prostate cancer, 1990-2013.JAMA. 2015; 314: 80-82Crossref PubMed Scopus (504) Google Scholar). Although extensive progress has been made in PCa management (4Sandhu S. Moore C.M. Chiong E. Beltran H. Bristow R.G. Williams S.G. Prostate cancer.Lancet. 2021; 398: 1075-1090Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar), there is still no cure for mCRPC. Therefore, it remains urgent to develop more effective strategies for the early diagnosis, treatment, and prevention of mCRPC. Cancer cells often hijack cell signaling to reprogram the metabolism to support their fast growth (5DeBerardinis R.J. Chandel N.S. Fundamentals of cancer metabolism.Sci. Adv. 2016; 2e1600200Crossref PubMed Scopus (1670) Google Scholar, 6Hanahan D. Weinberg R.A. Hallmarks of cancer: the next generation.Cell. 2011; 144: 646-674Abstract Full Text Full Text PDF PubMed Scopus (45628) Google Scholar). Emerging evidence shows that abnormal fatty acid metabolism in cancer cells promotes cancer progression by providing crucial fatty acids needed for membrane synthesis, cell signaling, energy, and NADPH production (7Currie E. Schulze A. Zechner R. Walther T.C. Farese Jr., R.V. Cellular fatty acid metabolism and cancer.Cell. Metab. 2013; 18: 153-161Abstract Full Text Full Text PDF PubMed Scopus (1328) Google Scholar). There are three main sources of fatty acids in cancer cells: (1) exogenous intake of fatty acids, (2) lipolysis, and (3) de novo fatty acid synthesis from acetyl-CoA (8Carracedo A. Cantley L.C. Pandolfi P.P. Cancer metabolism: fatty acid oxidation in the limelight.Nat. Rev. Cancer. 2013; 13: 227-232Crossref PubMed Scopus (838) Google Scholar). Unlike most normal human cells, which obtain fatty acids through exogenous pathways, cancer cells depend on de novo synthesis (9Ookhtens M. Kannan R. Lyon I. Baker N. Liver and adipose tissue contributions to newly formed fatty acids in an ascites tumor.Am. J. Physiol. 1984; 247: R146-R153PubMed Google Scholar). Therefore, hyperactivated de novo fatty acid synthesis has become a metabolic feature of many cancer types, including PCa, which is regarded as a promising target for cancer treatment (7Currie E. Schulze A. Zechner R. Walther T.C. Farese Jr., R.V. Cellular fatty acid metabolism and cancer.Cell. Metab. 2013; 18: 153-161Abstract Full Text Full Text PDF PubMed Scopus (1328) Google Scholar, 10Rossi S. Graner E. Febbo P. Weinstein L. Bhattacharya N. Onody T. et al.Fatty acid synthase expression defines distinct molecular signatures in prostate cancer.Mol. Cancer Res. 2003; 1: 707-715PubMed Google Scholar, 11Zadra G. Photopoulos C. Tyekucheva S. Heidari P. Weng Q.P. Fedele G. et al.A novel direct activator of AMPK inhibits prostate cancer growth by blocking lipogenesis.EMBO. Mol. Med. 2014; 6: 519-538Crossref PubMed Scopus (155) Google Scholar, 12Singh K.B. Kim S.H. Hahm E.R. Pore S.K. Jacobs B.L. Singh S.V. Prostate cancer chemoprevention by sulforaphane in a preclinical mouse model is associated with inhibition of fatty acid metabolism.Carcinogenesis. 2018; 39: 826-837Crossref PubMed Scopus (37) Google Scholar, 13De Schrijver E. Brusselmans K. Heyns W. Verhoeven G. Swinnen J.V. RNA interference-mediated silencing of the fatty acid synthase gene attenuates growth and induces morphological changes and apoptosis of LNCaP prostate cancer cells.Cancer Res. 2003; 63: 3799-3804PubMed Google Scholar). The rate-limiting enzyme in fatty acid de novo synthesis is acetyl-CoA carboxylase 1 (ACC1, encoded by acetyl-CoA carboxylase alpha (ACACA)), which catalyzes acetyl-CoA carboxylation to form malonyl-CoA. Both acetyl-CoA and malonyl-CoA are substrates for long-chain fatty acid synthesis (14Wakil S.J. Abu-Elheiga L.A. Fatty acid metabolism: target for metabolic syndrome.J. Lipid. Res. 2009; 50: S138-S143Abstract Full Text Full Text PDF PubMed Scopus (494) Google Scholar). Therefore, targeting ACACA to inhibit de novo fatty acid synthesis has been tested in multiple types of cancer, including lung cancer cells, breast cancer, and hepatocellular carcinoma (15Svensson R.U. Parker S.J. Eichner L.J. Kolar M.J. Wallace M. Brun S.N. et al.Inhibition of acetyl-CoA carboxylase suppresses fatty acid synthesis and tumor growth of non-small-cell lung cancer in preclinical models.Nat. Med. 2016; 22: 1108-1119Crossref PubMed Scopus (317) Google Scholar, 16Chajès V. Cambot M. Moreau K. Lenoir G.M. Joulin V. Acetyl-CoA carboxylase alpha is essential to breast cancer cell survival.Cancer Res. 2006; 66: 5287-5294Crossref PubMed Scopus (293) Google Scholar, 17Lally J. Ghoshal S. DePeralta D.K. Moaven O. Wei L. Masia R. et al.Inhibition of acetyl-CoA carboxylase by phosphorylation or the inhibitor ND-654 suppresses lipogenesis and hepatocellular carcinoma.Cell. Metab. 2019; 29: 174-182.e5Abstract Full Text Full Text PDF PubMed Scopus (184) Google Scholar). However, in other cases, inhibition of ACACA has been shown to promote cancer cell survival and metastasis (18Jeon S.M. Chandel N.S. Hay N. AMPK regulates NADPH homeostasis to promote tumour cell survival during energy stress.Nature. 2012; 485: 661-665Crossref PubMed Scopus (851) Google Scholar, 19Rios Garcia M. Steinbauer B. Srivastava K. Singhal M. Mattijssen F. Maida A. et al.Acetyl-CoA carboxylase 1-dependent protein acetylation controls breast cancer metastasis and recurrence.Cell. Metab. 2017; 26: 842-855.e5Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar). Interestingly, depletion of ACACA by siRNA in LNCaP cells decreases proliferation and increases apoptosis (20Brusselmans K. De Schrijver E. Verhoeven G. Swinnen J.V. RNA interference-mediated silencing of the acetyl-CoA-carboxylase-alpha gene induces growth inhibition and apoptosis of prostate cancer cells.Cancer Res. 2005; 65: 6719-6725Crossref PubMed Scopus (247) Google Scholar) but not in benign human BPH-1 cells or normal human skin fibroblasts. Recently, we also discovered that the inhibition of ACACA in CRPC cells led to mitochondrial damage and suppressed cell proliferation both in vivo and in vitro (21Zhang H. Liu S. Cai Z. Dong W. Ye J. Cai Z. et al.Down-regulation of ACACA suppresses the malignant progression of prostate cancer through inhibiting mitochondrial potential.J. Cancer. 2021; 12: 232-243Crossref PubMed Google Scholar). However, it is still unclear how de novo synthesis of fatty acids contributes to CRPC cell metabolism and how it contributes to cancer cell progression in CRPC cells. Furthermore, how mCRPC cells escape ACACA depletion is also unknown. To address this unmet challenge, we depleted ACACA expression in the androgen-independent CRPC cell lines DU145 and PC3. We found that depletion of ACACA reduced de novo fatty acid synthesis and PI3K/AKT signaling, downregulated mitochondrial beta-oxidation, resulting in mitochondrial dysfunction, and induced apoptosis, which was exacerbated by reducing exogenous fatty acids. The results suggest that inhibition of ectopic ACACA, together with suppression of exogenous fatty acid uptake, can be a novel strategy for treating currently uncurable CRPC. First, we analyzed the public PCa dataset to mine the key abnormally expressed molecules related to the de novo fatty acid synthesis in human PCa. In to the fatty acid metabolism gene from the gene we also key that most to de novo fatty acid we multiple PCa and prostate from the including the dataset cases of cancer and cases of The Cancer cases of cancer and cases of and dataset cases of cancer and cases of We and expressed fatty acid from the datasets, the expression of was increased in cancer and the expression of the other was reduced We how the expression of related to the of PCa. from that of had an on the survival of PCa. However, the expression of found to be related to disease-free survival expression of and was by expression of ACACA and was by Furthermore, of the that the expression of ACACA in PCa was the cancer types ACACA expression in PCa cells was the both the and protein with cell types in the Cancer and Furthermore, of the dataset cases of cancer and cases of and dataset cases of cancer and cases of in the also that ACACA was highly expressed in PCa with the expression of PCa and that PCa had a ACACA expression prostate tissue the protein cases mCRPC and cases localized are including in the we analyzed and found that mCRPC had a high ACACA expression the localized our suggest that ACACA is a target for de novo fatty acid synthesis in PCa. ACACA is the rate-limiting enzyme of de novo fatty acid synthesis and a crucial in PCa To how ACACA contributes to the fatty acid metabolism of CRPC cells, shRNA was to ACACA in DU145 and cells through that the expression of ACACA was depleted both the and protein and the fatty acid was reduced in cells was to the in cells. The of was found to be in cells. We analyzed the and downregulated with a public metabolic The results changes in metabolic However, only the fatty acid metabolism and the mitochondrial of the long-chain fatty acid downregulated Furthermore, to the related to ACACA in PCa, public The that related to fatty acid metabolism and fatty acid and To the of ACACA in the we the molecular of ACACA with the and and The that molecules had a with ACACA which de novo fatty acid the gene of fatty acid which is a key enzyme for fatty acid synthesis, a with ACACA in both The ACACA and was which was the the and dataset for and the that fatty acid synthase was and was to the changes of cells. that PI3K/AKT signaling was and the that gene related to fatty acid synthesis and PI3K/AKT downregulated and that expression was downregulated in cells and In addition, the of and also downregulated in cells and are both key of the de novo fatty acid synthesis which are for and to providing the for de novo fatty acid and are in the fatty acid synthesis, we the protein expression of their activation The downregulated in both and ACACA acid cells, AMPK alpha was The expression of and not and Furthermore, data mining also a ACACA and and expression in the the data suggest that depletion of ACACA the de novo fatty acid synthesis of CRPC cells multiple In to and fatty acids also serve as an energy which as ATP as through mitochondrial (8Carracedo A. Cantley L.C. Pandolfi P.P. Cancer metabolism: fatty acid oxidation in the limelight.Nat. Rev. Cancer. 2013; 13: 227-232Crossref PubMed Scopus (838) Google Scholar). that related to mitochondrial in CRPC cells The that the oxygen rate was in cells together with ATP production, and However, the by the of exogenous was ACACA was pharmacological inhibition by The results suggest that depletion of ACACA mitochondrial Furthermore, that the mitochondrial was reduced in both and cells, which also by the of exogenous 1 catalyzes the of fatty to an essential for the mitochondrial of fatty acids and the in the that the expression of and was downregulated in cells inhibits through the production of malonyl-CoA and regulates fatty acid The expression of was increased in cells, which downregulated and suppressed mitochondrial and Fatty acid NADPH is for cancer cells to the that the was increased in cells which was by the reduction in mitochondrial of fatty acids. According to the apoptosis was with cells with that expression of ACACA suppressed apoptosis cell increased apoptosis in cells and also that depletion of ACACA increased the of and in CRPC cells and To depletion of ACACA induced in CRPC cells, was to reactive oxygen that the was increased in cells and also increased in cells Although are the for the production, the mitochondrial production was in the cells. The mitochondrial production was also by the of exogenous which had with the mitochondrial and are the three for the of exogenous fatty acids in cells. dataset that the expression of and was downregulated in PCa with normal prostate tissue that depletion of ACACA increased the expression of and in cells. depletion of ACACA also expression in DU145 cells, and expression was not and The data suggest that of exogenous lipid for the of novel fatty acid synthesis to the of To this the expression of cells by three apoptosis an increased apoptosis in the cells Furthermore, cells in a reduced of serum or that with those in cells in and had increased apoptosis In in apoptosis was in cells in serum However, the apoptosis of the cells in was by the of exogenous a acetyl-CoA carboxylase which has been in inhibiting fatty acid To the was as pharmacological inhibition of or DU145 cells in or or with or and or for that with those in cells in and had increased apoptosis and and and The cells in or with treatment and In addition, an increased expression with the cells, in and expression was downregulated in those cells. Furthermore, an increased with the cells, in and Cancer cells an for de novo fatty acid synthesis to the of cell PCa is no which it to treatment to fatty acid synthesis G. Photopoulos C. Tyekucheva S. Heidari P. Weng Q.P. Fedele G. et al.A novel direct activator of AMPK inhibits prostate cancer growth by blocking lipogenesis.EMBO. Mol. Med. 2014; 6: 519-538Crossref PubMed Scopus (155) Google Scholar, 12Singh K.B. Kim S.H. Hahm E.R. Pore S.K. Jacobs B.L. Singh S.V. Prostate cancer chemoprevention by sulforaphane in a preclinical mouse model is associated with inhibition of fatty acid metabolism.Carcinogenesis. 2018; 39: 826-837Crossref PubMed Scopus (37) Google Scholar, 13De Schrijver E. Brusselmans K. Heyns W. Verhoeven G. Swinnen J.V. RNA interference-mediated silencing of the fatty acid synthase gene attenuates growth and induces morphological changes and apoptosis of LNCaP prostate cancer cells.Cancer Res. 2003; 63: 3799-3804PubMed Google Scholar, I. A. T. E. S. et al.Fatty acid synthase is a key for in breast Mol. Scopus Google Scholar). In many related to fatty acid synthesis been including and F. Schulze A. The of fatty acid synthesis in Rev. Cancer. 2016; PubMed Scopus Google Scholar). However, most been on it has been reported that ACACA expression is in breast cancer, cancer, lung cancer, and prostate cancer (15Svensson R.U. Parker S.J. Eichner L.J. Kolar M.J. Wallace M. Brun S.N. et al.Inhibition of acetyl-CoA carboxylase suppresses fatty acid synthesis and tumor growth of non-small-cell lung cancer in preclinical models.Nat. Med. 2016; 22: 1108-1119Crossref PubMed Scopus (317) Google Scholar, 16Chajès V. Cambot M. Moreau K. Lenoir G.M. Joulin V. Acetyl-CoA carboxylase alpha is essential to breast cancer cell survival.Cancer Res. 2006; 66: 5287-5294Crossref PubMed Scopus (293) Google Scholar, 17Lally J. Ghoshal S. DePeralta D.K. Moaven O. Wei L. Masia R. et al.Inhibition of acetyl-CoA carboxylase by phosphorylation or the inhibitor ND-654 suppresses lipogenesis and hepatocellular carcinoma.Cell. Metab. 2019; 29: 174-182.e5Abstract Full Text Full Text PDF PubMed Scopus (184) Google Scholar, 19Rios Garcia M. Steinbauer B. Srivastava K. Singhal M. Mattijssen F. Maida A. et al.Acetyl-CoA carboxylase 1-dependent protein acetylation controls breast cancer metastasis and recurrence.Cell. Metab. 2017; 26: 842-855.e5Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar). Herein, we that ACACA was highly expressed in PCa, in and patients with ACACA expression had disease-free survival of ACACA in CRPC cells de novo synthesis of fatty acids and PI3K/AKT suppressed proliferation and reduced mitochondrial and increased and apoptosis. We also reported that depletion of ACACA the expression of and the key for de novo fatty acid Furthermore, we reported that reduced lipid or serum supplementation exacerbated apoptosis induced by ACACA that exogenous lipid for the of novel fatty acid synthesis in PCa cells. Therefore, suppression of lipid is needed to the of blocking de novo synthesis for PCa. In this we found that depletion of ACACA in CRPC cells mitochondrial and reduced ATP that the reduced in CRPC cells in the of the long-chain fatty acid synthesis data that expression of the mitochondrial membrane is the of inhibition in cells (7Currie E. Schulze A. Zechner R. Walther T.C. Farese Jr., R.V. Cellular fatty acid metabolism and cancer.Cell. Metab. 2013; 18: 153-161Abstract Full Text Full Text PDF PubMed Scopus (1328) Google Scholar, L. L. et as a target for prostate cancer.Mol. Cancer 2014; 13: PubMed Scopus Google Scholar, I. The of inhibition of fatty acid oxidation by Full Text PDF PubMed Google Scholar). expression of the fatty acid will the of fatty acids to for beta-oxidation, resulting in mitochondrial and increased energy in CRPC cells. with the of increased energy will of the in the cells and to cell apoptosis. data that de novo fatty acid synthesis induced cell damage and that depletion of ACACA increased the on serum lipid supplementation in cell The results suggest that the in de novo fatty acid synthesis in CRPC cells can be by the of exogenous fatty acids, which is the by which cancer cells treatment to de novo fatty acid synthesis F. Schulze A. The of fatty acid synthesis in Rev. Cancer. 2016; PubMed Scopus Google Scholar). results that depletion of ACACA led to increased expression of the lipid exogenous and support this Therefore, serum lipid and lipid can be an effective to the of for PCa. In ectopic expression of ACACA in PCa cells the on exogenous fatty acids, which are needed for fast membrane synthesis in PCa cells. of ACACA, together with blocking exogenous fatty acid uptake, will be a novel strategy for currently uncurable CRPC The human PCa cell lines DU145 and from the and in with or and The cells in a The acetyl-CoA carboxylase inhibitor and acid was in the cell The shRNA and from The shRNA was The and with the the cells by in of cells for and In addition, we 1 cells in for of to for cells with with for and was The for siRNA are in and from the dataset was from the and the fatty acid metabolism gene was from the The three analyzed for the expression of key related to fatty acid metabolism. The the target gene and other gene in was first by the gene was the of the The gene was in by the the of gene rate and The data of and for PCa patients from the and in the The expression data in public from the To the related to ACACA in PCa, expressed was and on the expression of ACACA in the the of The gene was by and as and and as and Prostate and and as J. G. Liu Z. Liu S. Cai Z. P. et signaling the by reprogramming expression and in prostate Res. 2018; PubMed Scopus Google Scholar). The by in acid was an to the with the The with with and in in of for the of the and to The for and in of fatty acid by for The to with fatty acid and to to the of the Fatty The for in the The was The of the cells by (21Zhang H. Liu S. Cai Z. Dong W. Ye J. Cai Z. et al.Down-regulation of ACACA suppresses the malignant progression of prostate cancer through inhibiting mitochondrial potential.J. Cancer. 2021; 12: 232-243Crossref PubMed Google Scholar). Both downregulated and analyzed on the for related RNA from tumor cells was with the RNA to the RNA and by RNA to the The with of and analyzed with a was to that of The for are in in in the of inhibitor and inhibitor The for protein the 1 The by to for The for blocking and with the in with with serum with three the with the for 1 three with to the in The with which with a for The is in in and for to The cells with and with with the the cells three with and with the for 1 the cells with for The by a was by in to the The cells with or in a for The cells three in cell of treatment was with for the of a to be analyzed with a The other with for and and to the cell and of cells in and for in was to the cells. with for the cells with for for was a cell for and to the cell and The was to the oxygen rate with the to the in The was to and 1 and for 1 in a to of 1 and 1 The was in an The results analyzed of 1 cells with an apoptosis to the the cells by a was to the apoptosis The was from We to the of 1 cells in a and for the of was to The for and for to the The was for the The NADPH and to the The to a and in a to NADPH and in a The was to and The from for The was to for from the was The was to the the was to the RNA of cells and The RNA and of was or RNA by a high The was from from the RNA We the on an the The was also We to to the of The of from to a was to expression for by The expressed with or and with by three was for the and the the was the data are in the main or in the The that no of with the of this S. Z. F. and W. Z. S. J. H. J. J. S. F. and W. Z. S. J. H. Z. F. and W. Z. S. J. H. F. C. Z. F. and W. Z. S. J. H. and W. Z. data S. J. H. F. and W. Z. S. J. S. H. Z. F. and W. Z. W. Z. with and ACACA and expression in the of exogenous lipid exacerbated apoptosis in CRPC cells. of the cells in or with the apoptosis in cell of and of in CRPC

Topics & Concepts