Suppression of Pyruvate Dehydrogenase Kinase by Dichloroacetate in Cancer and Skeletal Muscle Cells Is Isoform Specific and Partially Independent of HIF-1α

Milić, Nives Škorja; Dolinar, Klemen; Miš, Katarina; Matkovič, Urška; Bizjak, Maruša; Pavlin, Mojca; Podbregar, Matej; Pirkmajer, Sergej

doi:10.3390/ijms22168610

Cited by 20 publications

(19 citation statements)

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“…The decrease in PDK protein levels after DCA treatment could not be explained by differences in translation or protein stability. However, the decrease in PDK1 and PDK3 gene expression in MeWo cells by DCA may be caused in part through the inhibition of HIF1, as demonstrated in a recent study [ 30 ]. To gain more insight into the mechanism of action of DCA, we generated PDK1-4 knockdown cell lines.…”

Section: Discussionmentioning

confidence: 99%

“…These results indicate that the effect of AZD7545 on the OCR:ECAR ratio is not only dependent on the inhibition of PDH phosphorylation [ 21 ]. Our observation that PDK2 protein levels are induced by AZD7545, while a reduction in PDK2 levels was observed with DCA, suggest that changes in protein abundance of PDK isoenzymes also have functional consequences [ 30 ]. Whether the different binding sites of DCA and AZD7545 [ 21 ] play a role in PDK isoenzyme stability and abundance should be further investigated.…”

Section: Discussionmentioning

confidence: 99%

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Pyruvate Dehydrogenase Kinase Inhibition by Dichloroacetate in Melanoma Cells Unveils Metabolic Vulnerabilities

Tiersma

Evers

Bakker

et al. 2022

IJMS

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Melanoma is characterized by high glucose uptake, partially mediated through elevated pyruvate dehydrogenase kinase (PDK), making PDK a potential treatment target in melanoma. We aimed to reduce glucose uptake in melanoma cell lines through PDK inhibitors dichloroacetate (DCA) and AZD7545 and through PDK knockdown, to inhibit cell growth and potentially unveil metabolic co-vulnerabilities resulting from PDK inhibition. MeWo cells were most sensitive to DCA, while SK-MEL-2 was the least sensitive, with IC50 values ranging from 13.3 to 27.0 mM. DCA strongly reduced PDH phosphorylation and increased the oxygen consumption rate:extracellular acidification rate (OCR:ECAR) ratio up to 6-fold. Knockdown of single PDK isoforms had similar effects on PDH phosphorylation and OCR:ECAR ratio as DCA but did not influence sensitivity to DCA. Growth inhibition by DCA was synergistic with the glutaminase inhibitor CB-839 (2- to 5-fold sensitization) and with diclofenac, known to inhibit monocarboxylate transporters (MCTs) (3- to 8-fold sensitization). CB-839 did not affect the OCR:ECAR response to DCA, whereas diclofenac strongly inhibited ECAR and further increased the OCR:ECAR ratio. We conclude that in melanoma cell lines, DCA reduces proliferation through reprogramming of cellular metabolism and synergizes with other metabolically targeted drugs.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Pyruvate Dehydrogenase Kinase Inhibition by Dichloroacetate in Melanoma Cells Unveils Metabolic Vulnerabilities

Tiersma

Evers

Bakker

et al. 2022

IJMS

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“…The inhibition of PDKs by DCA, alone or in combination with other drugs, has been proposed as an alternative therapeutic anti-cancer approach, especially in chemoresistant tumors ( 34 , 53 – 56 ). In our study, treatment of LNCaP and DU-145 PCa cells with DCA resulted in diminished cell proliferation, suggesting the feasibility of DCA, or DCA-related drugs, in the treatment of PCa.…”

Section: Discussionmentioning

confidence: 99%

“…The mRNA expression patterns of these genes in prostate tissues and prostate tumors are distinct, as shown in databases GTEx (Genotype-Tissue Expression; ) and TCGA (The Cancer Genome Atlas; ), but comprehensive comparative studies on the expression at the protein level of these enzymes in PCa are lacking. The association of PDKs expression with poor prognosis and resistance to anti-cancer therapies is widely documented, and PDKs inhibition (which results in PDH activation) constitutes a potential therapeutic possibility in several cancer types, including PCa ( 28 – 34 ). In addition, differing results have been reported on the association of other PDH components, such as PDHA1 and PDP1, with PCa prognosis ( 35 , 36 ).…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous Expression and Subcellular Localization of Pyruvate Dehydrogenase Complex in Prostate Cancer

et al. 2022

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BackgroundPyruvate dehydrogenase (PDH) complex converts pyruvate into acetyl-CoA by pyruvate decarboxylation, which drives energy metabolism during cell growth, including prostate cancer (PCa) cell growth. The major catalytic subunit of PDH, PDHA1, is regulated by phosphorylation/dephosphorylation by pyruvate dehydrogenase kinases (PDKs) and pyruvate dehydrogenase phosphatases (PDPs). There are four kinases, PDK1, PDK2, PDK3 and PDK4, which can phosphorylate and inactivate PDH; and two phosphatases, PDP1 and PDP2, that dephosphorylate and activate PDH.MethodsWe have analyzed by immunohistochemistry the expression and clinicopathological correlations of PDHA1, PDP1, PDP2, PDK1, PDK2, PDK3, and PDK4, as well as of androgen receptor (AR), in a retrospective PCa cohort of patients. A total of 120 PCa samples of representative tumor areas from all patients were included in tissue microarray (TMA) blocks for analysis. In addition, we studied the subcellular localization of PDK2 and PDK3, and the effects of the PDK inhibitor dichloroacetate (DCA) in the growth, proliferation, and mitochondrial respiration of PCa cells.ResultsWe found heterogeneous expression of the PDH complex components in PCa tumors. PDHA1, PDP1, PDK1, PDK2, and PDK4 expression correlated positively with AR expression. A significant correlation of PDK2 immunostaining with biochemical recurrence and disease-free survival was revealed. In PCa tissue specimens, PDK2 displayed cytoplasmic and nuclear immunostaining, whereas PDK1, PDK3 and PDK4 showed mostly cytoplasmic staining. In cells, ectopically expressed PDK2 and PDK3 were mainly localized in mitochondria compartments. An increase in maximal mitochondrial respiration was observed in PCa cells upon PDK inhibition by DCA, in parallel with less proliferative capacity.ConclusionOur findings support the notion that expression of specific PDH complex components is related with AR signaling in PCa tumors. Furthermore, PDK2 expression associated with poor PCa prognosis. This highlights a potential for PDH complex components as targets for intervention in PCa.

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“…After hZIP1 silencing by hZIP1-siRNA, HIF-1a augmented, and PDK1, GLUT1, and LDHA also showed an increasing tendency (cell experiments were performed using Caki-1 and OSRC-2). PDK1 plays a significant role in aerobic glycolysis and regulates the biological behavior of tumor cells (25)(26)(27). According to the analysis of TCGA database, HIF-1a was significantly downregulated in ccRCC tissues compared to that in normal renal tissues.…”

Section: Discussionmentioning

confidence: 99%

hZIP1 Inhibits Progression of Clear Cell Renal Cell Carcinoma by Suppressing NF-kB/HIF-1α Pathway

et al. 2021

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PurposeAccumulating literature has suggested that hZIP1 and HIF-1α play vital roles in the tumor process of clear cell renal cell carcinoma (ccRCC). However, the functional roles of hZIP1 and HIF-1α in ccRCC remain largely unknown.MethodsHIF-1α protein level was evaluated by a western blot in ccRCC tissues and cell lines. ccRCC cell lines were transfected with HIF-1α-siRNA to downregulate the expression level of HIF-1α. Then the proliferative, migratory and invasive abilities of ccRCC cells in vitro were detected by real-time cell analysis (RTCA) assay, wound healing assay and transwell assay, respectively. The role of HIF-1α in vivo was explored by tumor implantation in nude mice. Then the effect on glycolysis‐related proteins was performed by western blot after hZIP1 knockdown (overexpression) or HIF-1α knockdown. The effect on NF‐kB pathway was detected after hZIP1 overexpression.ResultsHIF-1α was markedly downregulated in ccRCC tissues compared with normal areas. But HIF-1α presented almost no expression in HK-2 and ACHN cells. Immunofluorescence indicated HIF-1α and PDK1 expression in both the cytoplasm and nucleus in ccRCC cells. Downregulation of HIF-1α suppressed ccRCC cell proliferation, migration, and invasion and resulted in smaller implanted tumors in nude mice. Furthermore, hZIP1 knockdown elevated HIF-1α protein levels and PDK1 protein levels in ccRCC cells. Interestingly, a sharp downregulated expression of HIF-1α was observed after hZIP1 overexpression in OSRC-2 and 786-O cells, which resulted from a downtrend of NF-kB1 moving into the cell nucleus.ConclusionOur work has vital implications that hZIP1 suppresses ccRCC progression by inhibiting NF-kB/HIF-1α pathway.

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Suppression of Pyruvate Dehydrogenase Kinase by Dichloroacetate in Cancer and Skeletal Muscle Cells Is Isoform Specific and Partially Independent of HIF-1α

Cited by 20 publications

References 91 publications

Pyruvate Dehydrogenase Kinase Inhibition by Dichloroacetate in Melanoma Cells Unveils Metabolic Vulnerabilities

Pyruvate Dehydrogenase Kinase Inhibition by Dichloroacetate in Melanoma Cells Unveils Metabolic Vulnerabilities

Heterogeneous Expression and Subcellular Localization of Pyruvate Dehydrogenase Complex in Prostate Cancer

hZIP1 Inhibits Progression of Clear Cell Renal Cell Carcinoma by Suppressing NF-kB/HIF-1α Pathway

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