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Fig. S1. Principal component analysis (PCA) of QC and experimental samples. Fig S2. Determination of chemical structures of metabolites in serum extract by tandem mass spectrometry. Fig. S3. Relative abundance of the 11 metabolites in the pemetrexed monotherapy set. Fig. S4. 5-fold cross validation result. Fig. S5. ROC analysis of the discovery set. Fig. S6. Relative abundance of the 11 metabolites in the validation set. Fig. S7. ROC analysis of the validation set. Fig. S8. Parameter settings for LC-MS/MS. Supplementary Table S1. Metabolites identified in the discovery set. Supplementary Table S2. The likelihood score in different models with various number of variables.

The mitochondrial serine hydroxymethyltransferase SHMT2, which catalyzes the rate-limiting step in serine catabolism, drives cancer cell proliferation, but how this role is regulated is undefined. Here, we report that the sirtuin SIRT5 desuccinylates SHMT2 to increase its activity and drive serine catabolism in tumor cells. SIRT5 interaction directly mediated desuccinylation of lysine 280 on SHMT2, which was crucial for activating its enzymatic activity. Conversely, hypersuccinylation of SHMT2 at lysine 280 was sufficient to inhibit its enzymatic activity and downregulate tumor cell growth in vitro and in vivo. Notably, SIRT5 inactivation led to SHMT2 enzymatic downregulation and to abrogated cell growth under metabolic stress. Our results reveal that SHMT2 desuccinylation is a pivotal signal in cancer cells to adapt serine metabolic processes for rapid growth, and they highlight SIRT5 as a candidate target for suppressing serine catabolism as a strategy to block tumor growth.Significance: These findings reveal a novel mechanism for controlling cancer cell proliferation by blocking serine catabolism, as a general strategy to impede tumor growth. Cancer Res; 78(2); 372–86. ©2017 AACR.

Figure S1 shows the SIRT5 interaction network and SHMT2 identification. Figure S2 shows that SIRT5 is irreplaceable for cancer cell in response to serine deprivation. Figure S3 shows that SIRT5 desuccinylates SHMT2. Figure S4 shows that SIRT5 upregulates SHMT2 enzymatic activity under metabolic stress. Figure S5 shows that K280 is the major succinylation site of SHMT2. Figure S6 shows that succinylation of SHMT2 at K280 restrains cellular redox balance and clonogenic growth. Figure S7 shows that succinylation of SHMT2 at K280 impairs tumor cell growth in vivo and in vitro

Purpose: No validated biomarkers that could identify the subset of patients with lung adenocarcinoma who might benefit from chemotherapy have yet been well established. This study aimed to explore potential biomarker model predictive of efficacy and survival outcomes after first-line pemetrexed plus platinum doublet based on metabolomics profiling.Experimental Design: In total, 354 consecutive eligible patients were assigned to receive first-line chemotherapy of pemetrexed in combination with either cisplatin or carboplatin. Prospectively collected serum samples before initial treatment were utilized to perform metabolomics profiling analyses under the application of LC/MS-MS. Binary logistic regression analysis was carried out to establish discrimination models.Results: There were 251 cases randomly sorted into discovery set, the rest of 103 cases into validation set. Seven metabolites including hypotaurine, uridine, dodecanoylcarnitine, choline, dimethylglycine, niacinamide, and l-palmitoylcarnitine were identified associated with chemo response. On the basis of the seven-metabolite panel, a discriminant model according to logistic regression values g(z) was established with the receiver operating characteristic curve (AUC) of 0.912 (Discovery set) and 0.909 (Validation set) in differentiating progressive disease (PD) groups from disease control (DC) groups. The median progression-free survival (PFS) after chemotherapy in patients with g(z) ≤0.155 was significantly longer than that in those with g(z) > 0.155 (10.3 vs.4.5 months, P < 0.001).Conclusions: This study developed an effective and convenient discriminant model that can accurately predict the efficacy and survival outcomes of pemetrexed plus platinum doublet chemotherapy prior to treatment delivery. Clin Cancer Res; 24(9); 2100–9. ©2018 AACR.

E2F-1 mediates apoptosis through transcriptional regulation of its targets. We report here that E2F-1 acts as a direct transcriptional regulator of dual specificity phosphatase 1 (DUSP1; CL100), a threonine and tyrosine phosphatase that inhibits mitogen-activated protein (MAP) kinases. We found that DUSP1 is transcriptionally induced by ectopic E2F-1 expression and that extracellular signal–regulated kinase 1/2 are dephosphorylated in the presence of E2F-1 and DUSP1. E2F-1 mediates apoptosis in the cellular response to oxidative stress. DUSP1 levels are significantly increased in an E2F-1–dependent manner following oxidative stress but not other stresses examined. DUSP1 mediates the cellular response to oxidative stress. We found that E2F-1 binds to chromatin encompassing the DUSP1 promoter and greatly stimulates the promoter activity of the DUSP1 gene. In particular, E2F-1 physically binds to an E2F-1 consensus sequence and a palindromic motif in the DUSP1 promoter. Interestingly, E2F-1 is acetylated following oxidative stress. Our findings show that E2F-1 is a transcriptional activator of DUSP1 and that DUSP1 is a link between E2F-1 and MAP kinases. [Cancer Res 2007;67(14):6737–44]

Supplementary Figure Legend from Dual Specificity Phosphatase 1/CL100 Is a Direct Transcriptional Target of E2F-1 in the Apoptotic Response to Oxidative Stress

Supplementary Table 1 from Dual Specificity Phosphatase 1/CL100 Is a Direct Transcriptional Target of E2F-1 in the Apoptotic Response to Oxidative Stress

Purpose: No validated biomarkers that could identify the subset of patients with lung adenocarcinoma who might benefit from chemotherapy have yet been well established. This study aimed to explore potential biomarker model predictive of efficacy and survival outcomes after first-line pemetrexed plus platinum doublet based on metabolomics profiling. Experimental Design: In total, 354 consecutive eligible patients were assigned to receive first-line chemotherapy of pemetrexed in combination with either cisplatin or carboplatin. Prospectively collected serum samples before initial treatment were utilized to perform metabolomics profiling analyses under the application of LC/MS-MS. Binary logistic regression analysis was carried out to establish discrimination models. Results: There were 251 cases randomly sorted into discovery set, the rest of 103 cases into validation set. Seven metabolites including hypotaurine, uridine, dodecanoylcarnitine, choline, dimethylglycine, niacinamide, and l-palmitoylcarnitine were identified associated with chemo response. On the basis of the seven-metabolite panel, a discriminant model according to logistic regression values g(z) was established with the receiver operating characteristic curve (AUC) of 0.912 (Discovery set) and 0.909 (Validation set) in differentiating progressive disease (PD) groups from disease control (DC) groups. The median progression-free survival (PFS) after chemotherapy in patients with g(z) ≤0.155 was significantly longer than that in those with g(z) > 0.155 (10.3 vs.4.5 months, P < 0.001). Conclusions: This study developed an effective and convenient discriminant model that can accurately predict the efficacy and survival outcomes of pemetrexed plus platinum doublet chemotherapy prior to treatment delivery. Clin Cancer Res; 24(9); 2100–9. ©2018 AACR.

The mitochondrial serine hydroxymethyltransferase SHMT2, which catalyzes the rate-limiting step in serine catabolism, drives cancer cell proliferation, but how this role is regulated is undefined. Here, we report that the sirtuin SIRT5 desuccinylates SHMT2 to increase its activity and drive serine catabolism in tumor cells. SIRT5 interaction directly mediated desuccinylation of lysine 280 on SHMT2, which was crucial for activating its enzymatic activity. Conversely, hypersuccinylation of SHMT2 at lysine 280 was sufficient to inhibit its enzymatic activity and downregulate tumor cell growth in vitro and in vivo. Notably, SIRT5 inactivation led to SHMT2 enzymatic downregulation and to abrogated cell growth under metabolic stress. Our results reveal that SHMT2 desuccinylation is a pivotal signal in cancer cells to adapt serine metabolic processes for rapid growth, and they highlight SIRT5 as a candidate target for suppressing serine catabolism as a strategy to block tumor growth. Significance: These findings reveal a novel mechanism for controlling cancer cell proliferation by blocking serine catabolism, as a general strategy to impede tumor growth. Cancer Res; 78(2); 372–86. ©2017 AACR.

PTEN phosphatase is a potent tumor suppressor that regulates multiple cellular functions. In the cytoplasm, PTEN dephosphorylates its primary lipid substrate, phosphatidylinositol 3,4,5-trisphosphate, to antagonize the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway. It has also become increasingly evident that PTEN functions in the nucleus and may play an important part in transcription regulation, but its nuclear targets remain elusive. In this report, we demonstrate the transcription factor cyclic AMP response element-binding protein (CREB) is a protein target of PTEN phosphatase and that PTEN deficiency leads to CREB phosphorylation independent of the PI3K/AKT pathway. Using confocal immunofluorescence and reciprocal immunoprecipitation, we further show that PTEN colocalizes with CREB and physically interacts with CREB. Moreover, we use both in vitro and in vivo experiments to show PTEN can dephosphorylate CREB in a phosphatase-dependent manner, suggesting that CREB is a substrate of PTEN nuclear phosphatase. Loss of Pten results in an elevated RNA level of multiple CREB transcriptional targets and increased cell proliferation, which can be reversed by a nonphosphorylatable CREB mutant or knockdown of CREB. These data reveal a mechanism for PTEN modulation of CREB-mediated gene transcription and cell growth. Our study thus characterizes PTEN as a nuclear phophatase of a transcription factor and identifies CREB as a novel protein target of PTEN phosphatase, which contributes to better understanding of PTEN function in the nucleus. Cancer Res; 71(8); 2821–5. ©2011 AACR.