Cancer & Metabolism最新文献

Background: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatocellular cancer. This study investigated whether ETV4, ALYREF, and PKM2 affect glycolytic metabolism and ferroptosis, thereby potentially influencing ICC.

Methods: Bioinformatic analysis was used to explore the expression levels and prognosis of ETV4, ALYREF, and PKM2 in ICC and their regulatory relationships were confirmed using in vitro experiments. Glycolytic metabolism and ferroptosis were examined, and chromatin immunoprecipitation and RNA immunoprecipitation experiments were performed to verify whether the ETV4, PKM2, and ALYREF could bind. The effect of ETV4/ALYREF on ICC was further confirmed by in vivo experiments.

Results: ETV4, ALYREF, and PKM2 were highly expressed in ICC. Overexpressed (oe)-ETV4 and oe-PKM2 promoted cell migration and increased glucose (GLU) utilization and lactate and intracellular adenosine triphosphate (ATP) production. Addition of the ferroptosis inducer Erastin to the above groups revealed that sh-ETV4 and sh-ALYREF increased lipid reactive oxygen species (ROS), malondialdehyde (MDA), and Fe²⁺ levels, and oe-PKM2 reversed these effects in the sh-ETV4 and sh-ALYREF groups. Oe-ETV4 promoted the expression of PKM2, whereas sh-ALYREF inhibited the same. ETV4 could bind to ALYREF and PKM2 promoter, and ALYREF could promote the stability of PKM2 in an m5C-dependent manner. In vivo, ETV4 promotes tumor growth and the expression of proteins related to glycolytic metabolism by regulating ALYREF.

Conclusion: ETV4 promotes ICC development and ferroptosis resistance by facilitating glycolytic metabolism, and regulating PKM2 transcription by directly binding to the PKM2 promoter. Additionally, it mediates m5C-dependent PKM2 stabilization by directly binding to ALYREF. This study identified a new potential therapeutic target for ICC.

Background: While the triggers for the metastatic transformation of breast cancer (BC) cells remain unknown, recent evidence suggests that intrinsic cellular metabolism could be a crucial driver of migratory disposition and chemoresistance. Aiming to decipher the molecular mechanisms involved in BC cell metabolic maneuvering, we study how a ketomimetic (ketone body-rich, low glucose) nutrient medium can engineer the glycocalyx and metabolic signature of BC cells, to further maneuver their response to therapy.

Methods: Doxorubicin (DOX) has been used as a model chemotherapeutic in this study. Bioorthogonal imaging was used to assess the degree of sialylation of the glycocalyx along with measurements of drug-induced cytotoxicity and drug internalization. Single cell label-free metabolic imaging has been performed, coupled with measurement of cellular proliferative and migratory abilities, and MS-based metabolomic screens. Transcriptomic analysis of crucial enzymes was performed using total RNA extraction and rt-qPCR.

Results: We found an inverse correlation of glycocalyx sialylation with drug-induced cytotoxicity and drug internalization, where ketomimetic media enhanced sialylation and protected BC cells from DOX. These hypersialylated cells proliferated slower and migrated faster as compared to their counterparts receiving a high glucose media, while exhibiting a preference for glycolysis. These cells also showed pronounced lipid droplet accumulation coupled with an inversion in their metabolomic profile. Enzymatic removal of sialic acid moieties at the glycocalyx revealed for the first time, a direct role of sialic acids as defense guards, blocking DOX entry at the cellular membrane to curtail internalization. Interestingly, the non-cancerous mammary epithelial cells exhibited opposite trends and this differential pattern in cancer vs. normal cells was traced to its biochemical roots, i.e. the expression levels of key enzymes involved in sialylation and fatty acid synthesis.

Conclusions: Our findings revealed that a ketomimetic medium enhances chemoresistance and invasive disposition of BC cells via two main oncogenic pathways: hypersialylation and lipid synthesis. We propose that the crosstalk between these pathways, juxtaposed at the synthesis of the glycan precursor UDP-GlcNAc, furthers advancement of a metastatic phenotype in BC cells under ketomimetic conditions. Non-cancerous cells lack this dual defense machinery and end up being sensitized to DOX under ketomimetic conditions.

Background: Endometrial cancer (EC) is one of the most common cancers in women, with a short overall survival and poor prognosis. Besides the biologically aggressive EC properties, Cancer-associated cachexia is the main factor. However, the detailed mechanism underlying EC-related cachexia and its harmful effects on EC progression and patient prognosis remains unclear.

Methods: For clinical specimen and the vitro experiment, we detected TRIM22 expression level, EC patients' survival time, EC cell functional change, and adipose thermogenic changes to identify the function of TRIM22 in EC progression, EC-associated cachexia, and their molecular mechanisms. Then, for the vivo experiment, we exploited the xenografts in mice to identify the function of TRIM22 again, and to screen the drug therapeutic schedule.

Results: Herein, we demonstrated that TRIM22 inhibited EC cell growth, invasion, and migration. Interleukin (IL)-6 mediated brown adipose tissue activation and white adipose tissue browning which induced EC-related cachexia. TRIM22 suppressed the EC cells' secretion of IL-6, and IL-6 mediated EC-related cachexia. Mechanistically, TRIM22 inhibited EC progression by suppressing the nucleotide-binding oligomerization domain 2(NOD2)/nuclear factor-kappaB (NF-κB) signaling pathway, with the purpose of impeding the production of IL-6. Moreover, we revealed that TRIM22 inhibited EC-associated cachexia by suppressing the IL-6/IL-6 receptor (IL-6R) signaling pathway. Therapeutically, we demonstrated that combination treatment with a TRIM22 inducer (progesterone) and a thermogenic inhibitor (IL-6R antibody) synergistically augmented the antitumor efficacy of carbotaxol (carboplatin and paclitaxel), in vivo.

Conclusion: Our data reveals that TRIM22-EC-IL-6-cachexia cross-communication has important clinical relevance and that the use of combined therapy holds great promise for enhancing the efficacy of anti-ECs. (Fig. graphical abstract).

Background: Small cell lung cancer (SCLC) is an aggressive malignancy with distinct molecular subtypes defined by transcription factors and inflammatory characteristics. This follow-up study aimed to validate the unique metabolic phenotype in achaete-scute homologue 1 (ASCL1)-driven SCLC cell lines and human tumor tissue.

Methods: Metabolic alterations were analyzed using proteomic data. Structural and functional differences of mitochondria were investigated using qPCR, flow cytometry, confocal imaging, and transmission electron microscopy and seahorse assays. Several metabolic inhibitors were tested using MTT-based and clonogenic assays. Single-cell enzyme activity assays were conducted on cell lines and tumor tissue samples of SCLC patients.

Results: We found increased mitochondrial numbers correlating with higher oxidative phosphorylation activity in ASCL1-dominant cells compared to other SCLC subtypes. Metabolic inhibitors targeting mitochondrial respiratory complex-I or carnitine palmitoyltransferase 1 revealed higher responsiveness in SCLC-A. Conversely, we demonstrated that non-ASCL1-driven SCLCs with lower oxidative signatures show dependence on glutaminolysis as evidenced by the enhanced susceptibility to glutaminase inhibition. Accordingly, we detected increased glutamate-dehydrogenase activity in non-ASCL1-dominant cell lines as well as in human SCLC tissue samples.

Conclusions: Distinct SCLC subtypes exhibit unique metabolic vulnerabilities, suggesting potential for subtype-specific therapies targeting the respiratory chain, fatty acid transport, or glutaminolysis.

Background: Arginine metabolism in tumors is often shunted into the pathway producing pro-tumor and immune suppressive polyamines (PAs), while downmodulating the alternative nitric oxide (NO) synthesis pathway. Aiming to correct arginine metabolism in tumors, arginine deprivation therapy and inhibitors of PA synthesis have been developed. Despite some therapeutic advantages, these approaches have often yielded severe side effects, making it necessary to explore an alternative strategy. We previously reported that supplementing sepiapterin (SEP), the endogenous precursor of tetrahydrobiopterin (BH_4, the essential NO synthase cofactor), could correct arginine metabolism in tumor cells and tumor-associated macrophages (TAMs) and induce their metabolic and phenotypic reprogramming. We saw that oral SEP treatment effectively suppressed the growth of HER2-positive mammary tumors in animals. SEP also has no reported dose-dependent toxicity in clinical trials for metabolic disorders. In the present study, we tested our hypothesis that a long-term administration of SEP to individuals susceptible to HER2-positive mammary tumor would protect them against tumor occurrence.

Methods: We administered SEP, in comparison to control DMSO, to MMTV-neu mice susceptible to HER2-positive mammary tumors for 8 months starting at their pre-pubertal stage. We monitored tumor onsets to determine the rate of tumor-free survival. After 8 months of treatment, we grouped animals into DMSO treatment with or without tumors and SEP treatment with or without tumors. We analyzed blood metabolites, PBMC, and bone marrow of DMSO vs. SEP treated animals.

Results: We found that a long-term use of SEP in animals susceptible to HER2-positive mammary tumors effectively suppressed tumor occurrence. These SEP-treated animals had undergone reprogramming of the systemic metabolism and immunity, elevating total T cell counts in the circulation and bone marrow. Given that bone marrow-resident T cells are mostly memory T cells, it is plausible that chronic SEP treatment promoted memory T cell formation, leading to a potent tumor prevention.

Conclusions: These findings suggest the possible roles of the SEP/BH₄/NO axis in promoting memory T cell formation and its potential therapeutic utility for preventing HER2-positive breast cancer.

High-grade serous cancer (HGSC) is the most prevalent and aggressive subtype of ovarian cancer. In this study, we utilized liquid chromatography and mass spectrometry analysis to investigate metabolic alterations in HGSC. Among the 1353 metabolites identified, 140 were significantly differed between HGSC and normal ovarian tissue. KEGG pathway enrichment analysis revealed 23 distinct metabolic pathways, including the alanine/aspartate/glutamate metabolism, pyruvate metabolism, biosynthesis of amino acids, and citrate cycle, etc. Of the significantly differentiated metabolites, malic acid, fumarate, and phosphoenolpyruvate were found in the citrate cycle and glycolysis. In further analysis, 22 differentially expressed genes (DEGs) of glucose metabolism were found between HGSC and normal controls. Multivariate Cox analysis of the 22 DEGs showed that ME1, ALDOC, and RANBP2 were associated with overall survival in the TCGA cohort.Bioinformatic analysis indicated WTAP is strongly correlated to the expression of ME1, which is a rate-limiting enzyme that regulates the shuttle of malic acid in mitochondria and cytoplasm. After the knockdown of WTAP in A2780 and OVCAR-3 cells, the activity of the malic enzyme decreased which led to the accumulation of malic acid and citric acid, and the reduction of pyruvate and lactic acid. In A2780 and OVCAR-3 cells, the IC50 to platinum was increased after the knockdown of WTAP. After the knockdown of WTAP, the expression of ME1 was down-regulated and the m6A modification was down-regulated in ovarian cell lines. On the SRAMP website, there were two binding sites with high m6A scores at the 5 '-UTR 177 and 970 of ME1 mRNA. WTAP contributes to the platinum resistance through regulating the conversion from aerobic glycolysis to OXPHOS by upregulating the expression of ME1.

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma worldwide and is characterized by its heterogeneity. Although first-line therapy improves survival outcomes for DLBCL patients, approximately one third will relapse, often with a poor prognosis. Among the factors influencing prognosis and response to treatment in cancer patients, including those with lymphoma, overweight and obesity have emerged as significant considerations. However, the role of excess weight in DLBCL remains controversial, with studies reporting both negative and positive effects on cancer outcomes. In this translational substudy of the R2-GDP-GOTEL trial, we have evaluated the impact of excess weight as a predictor of treatment response and survival in patients with relapsed/refractory (R/R) DLBCL, and examining its relationship with immune cell dynamics.

Methods: Of the 79 patients who received the R2-GDP scheme in the phase II trial, weight and height parameters were obtained in 75 patients before starting treatment. Blood samples were analyzed by flow cytometry. Statistical analyses were performed to determine the prognostic value of overweight and obesity at baseline in R/R DLBCL patients.

Results: Our results indicate that overweight (including obese) patients exhibit longer survival compared to patients of ideal weight. This group also demonstrated a reduction of regulatory T cells with supposedly protumor activity and an increase of Natural Killer (NK)-like T cells with supposedly antitumor activity. Additionally, we have found that excess weight correlates with better treatment response, associated with elevated levels of vitamin D and CD8 + NK cells.

Conclusions: Our findings suggest that excess weight does not exacerbate the progression of DLBCL. Instead, it appears to confer a survival advantage and improve treatment response, with the immune system playing a possible pivotal role in mediating these effects.

Trial registration: EudraCT, ID:2014-001620-29.

Introduction: Triple-negative breast cancer (TNBC), which tends to be more advanced when diagnosed and more aggressive than other breast cancer subtypes, is accelerated by obesity. Hypertrophic adipocytes and cancer cells exhibit increased oxidative stress and altered redox homeostasis, influencing therapeutic outcomes. Enzymes implicated in both redox regulation and TNBC include glutathione peroxidase 4 (GPX4; reduces lipid peroxides) and pyruvate carboxylase (PC; essential in oxidative stress protection). Using preclinical models, we characterized interactions between GPX4, PC, and oxidative stress in TNBC cells, and established effects of GPX4 suppression on TNBC progression. In TNBC cells, PC knockdown increased GPX4 expression, while GPX4 knockdown increased PC expression. GPX4 inhibition by erastin or RSL3 enhanced TNBC cell death in vitro, and antioxidants mitigated the cytotoxicity. In obese mice, GPX4 knockdown, versus scramble control: (i) reduced tumor burden following orthotopic transplantation of TNBC cells; and (ii) reduced lung metastasis following tail vein injection of TNBC cells in combination with chemotherapy (carboplatin) but not immunotherapy (anti-CTLA4 plus anti-PD1). We conclude that GPX4 and PC expression are inversely related in TNBC cells, and GPX4 and obesity interact to impact TNBC progression and treatment responses. Moreover, GPX4-mediated redox defense, alone or in combination with chemotherapy, is a targetable vulnerability for treating TNBC, including obesity-related TNBC.

Implication: GPX4 suppression, alone or with current TNBC therapies, impacts outcomes in preclinical TNBC models with or without obesity and offers a new, plausible mechanistic target for TNBC treatment.

Serine metabolism provides important metabolic intermediates that support the rapid proliferation of tumor cells. However, the role of serine metabolism in esophageal squamous cell carcinoma (ESCC) and the underlying mechanism remains unclear. Here, we show that serine starvation predominantly inhibits ESCC cell proliferation by suppressing purine nucleotides and NADPH synthesis. Mechanistically, serine depletion led to the accumulation of aminoimidazole carboxamide ribonucleoside (AICAR), an intermediate metabolite of de novo purine synthesis, and AMP/ATP ratio. These increases activated 5'-AMP-activated kinase (AMPK), which subsequently inhibited the mTORC1 pathway by phosphorylating Raptor at Ser792. Moreover, serine depletion decreased NADPH level followed by elevated reactive oxygen species (ROS) production and DNA damage, which induced p53-p21 mediated G1 phase cell cycle arrest. Conversely, serine starvation activated transcription factor 4 (ATF4)-mediated robust expression of phosphoserine aminotransferase 1 (PSAT1) which in turn promoted compensatory endogenous serine synthesis, thus maintaining ESCC cell survival under serine-limited conditions. Accordingly, serine deprivation combined with PSAT1 inhibition significantly suppressed ESCC tumor growth both in vitro and in vivo. Taken together, our findings demonstrate that serine starvation suppresses the proliferation of ESCC cells by disturbing the synthesis of purine nucleotides and NADPH, and the combination of serine deprivation and PSAT1 inhibition significantly impairs ESCC tumor growth. Our study provides a theoretical basis for targeting serine metabolism as a potential therapeutic strategy for ESCC.