Cancer & Metabolism最新文献

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.

Introduction: This study aimed to evaluate the metabolic differences between MM cells derived from patients with elevated serum LDH levels and those without elevated serum LDH levels to identify biological differences that could be exploited for therapeutic purposes.

Methods: We performed transcriptome assessments of CD138 + MM cells derived from patients with elevated serum LDH levels compared to those without elevated serum LDH levels and validated the findings in a larger public dataset. Functional metabolic assessments of our findings were performed using a combination of stable isotope resolved metabolomics (SIRM), bioenergetic flux measurement assays, and live cell analysis in human myeloma cell lines and primary MM patient cells.

Results: We identified SLC16A1, responsible for the formation of MCT1, a well-defined bi-directional transporter of lactate in and out of a cell with a predilection to importing extracellular lactate, as differentially expressed between the two groups. This finding was functionally confirmed by higher membranous MCT1 protein expression and SIRM on MM cells derived from patients with elevated serum LDH levels compared to those without elevated serum LDH levels. Finally, disrupting lactate transport in and out of CD138 + MM cells was maximally achievable only with dual inhibition of MCT1 and its partner, MCT4, which was preferentially more cytotoxic in MM cells derived from patients with elevated serum levels of LDH.

Conclusion: MCT1 mRNA and protein expression distinguish MM cells derived from patients with elevated serum LDH levels from those without elevated serum LDH levels. However, only dual inhibition of MCT1 and MCT4 can disrupt lactate transport in multiple myeloma (MM) cells, with preferential cytotoxicity in MM cells from patients with high serum LDH levels.

Background: Melanoma is a highly aggressive skin cancer with a poor prognosis. The endocannabinoids 2-arachidonoylgylcerol (2-AG) and anandamide have been linked to melanoma progression, though their roles remain unclear. We hypothesized that the 2-AG-arachidonate-prostaglandin axis could drive aggressive melanoma progression.

Methods: The genetically engineered melanoma mouse model B6-Tyr::CreER^T2; BRaf^CA; Pten^loxP was characterized by targeted metabolomics. Functionally expressed serine hydrolases in the tumor tissue were identified by chemoproteomics. Pharmacological inhibition of carboxylesterase 1 (CES1) was achieved through chronic in vivo i.p. treatment with JZL184 (10 mg/kg daily), confirmed by activity-based protein profiling (ABPP) and targeted lipidomics. CES1-mediated 2-AG hydrolysis was further confirmed in radiotracer-based assays using CES1-transfected cell lines.

Results: The diacylglycerol and protein kinase C activator 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG) was significantly elevated in the nodular-like melanoma tissues, along with 2-AG and arachidonic acid (ARA), compared to normal skin. AEA and other N-acylethanolamines were decreased, while, notably, prostaglandin levels remained unchanged. Significant changes in the levels of neuromodulators and neurotransmitters, including serotonin and adenosine, were observed. Pronounced differences between serine hydrolase activity in normal skin and melanoma tissue were identified by ABPP. Intriguingly, CES1 was identified as the only 2-AG-hydrolyzing enzyme in this melanoma tissue, as MAGL and ABHD6/12 were not expressed. The MAGL inhibitor JZL184 also efficiently inhibited CES1 in vitro and in vivo, increasing glycerol esters and reducing tumor progression. Additionally, scRNA-seq data from previous studies revealed divergent MAGL/CES1 expression patterns across different human melanoma subtypes.

Conclusions: A role of CES1 expression in skin is demonstrated for the first time. Our study suggests that 2-AG degradation to arachidonate favors melanoma progression, either reflecting the carcinogenic role of ARA or that monoacylglycerols like 2-AG and/or other CES1 substrates may exert antitumor effects, indicating that CES1 could be a potential therapeutic target. CES1 expression and high SAG, 2-AG, and ARA levels may be a signature of specific BRAF-driven malignant melanoma subtypes which are associated with discrete metabolic adaptations.

Background: Lactate dehydrogenase A (LDHA) can regulate tumorigenesis and cancer progression. Nevertheless, whether the regulation of LDHA is involved in the development of gemcitabine resistance in PDAC has not yet been fully elucidated. Increasing studies have shown that cancer acquired drug resistance led to treatment failure is highly attributed to the cancer stem cell (CSC) properties. Therefore, we aim to demonstrate the functions and regulatory mechanisms of LDHA on cancer stem cell (CSC) properties and gemcitabine resistance in PDAC.

Methods: We investigate the metabolite profiles by liquid chromatography-mass spectrometry between gemcitabine-resistant PDAC and parental PDAC cells. Additionally, gain-of-function and loss-of-function experiments were conducted to examine the roles of LDHA on CSC properties and gemcitabine resistance in the gemcitabine-resistant PDAC and parental PDAC cells. To investigate regulators involved in LDHA-mediated gemcitabine resistance and CSC of pancreatic cancer cells, we further used a combination of the miRNA microarray results and software predictions and confirmed that miR-4259 is a direct target of LDHA by luciferase assay. Furthermore, we constructed serial miR-4259 promoter reporters and searched for response elements using the TESS 2.0/TFSEARCH software to find the transcription factor binding site in the promoter region of miR-4259.

Results: We observed that elevated LDHA expression significantly correlates with recurrent pancreatic cancer patients following gemcitabine treatment and with CSC properties. We further identify that FOXO3a-induced miR-4259 directly targets the 3'untranslated region of LDHA and reduced LDHA expression, leading to decreased gemcitabine resistance and a reduction in the CSC phenotypes of pancreatic cancer.

Conclusion: Our results demonstrated that LDHA plays a critical role in cancer stemness and gemcitabine resistance of pancreatic cancer, and indicate that targeting the FOXO3a/miR-4259/LDHA pathway might serve as a new treatment for pancreatic cancer patients with a poor response to gemcitabine chemotherapy.

Background: HER2-positive patients comprise approximately 20% of breast cancer cases, with HER2-targeted therapy significantly improving progression-free and overall survival. However, subsequent reprogramed tumor progression due to PI3K signaling pathway activation by PIK3CA mutations and/or PTEN-loss cause anti-HER2 resistance. Previously, alpha isoform-specific PI3K inhibitors were shown to potentiate HER2-targeted therapy in breast cancer cells carrying PI3K pathway alterations with less potent effects on PTEN-loss than PIK3CA-mutant cells. Therefore, seeking for alternative combination therapy needs urgent attentions in PTEN-loss anti-HER2 resistant breast cancer.

Methods: Since remodeling of fatty acid (FA) metabolism might contribute to HER-positive breast cancer and is triggered by the PI3K signal pathway, herein, we examined the effects of the inhibition of endogenous FA conversion, SCD-1 or exogenous FA transport, CD36, in combination with PI3K inhibitors (alpelisib and inavolisib) in anti-HER2 resistant PTEN-loss breast cancer cells.

Results: The activated HER2/PI3K/AKT/mTOR signaling pathway positively correlated with SCD-1 and CD36 expression in PTEN-loss breast cancer cells. PI3K inhibition downregulated SCD-1, and accordingly, the addition of the SCD-1 inhibitor did not augment the antiproliferative effects of the PI3K inhibitors. CD36 was upregulated by blocking the PI3K signal pathway or limited serum supplementation, indicating that suppressing CD36 may decrease the excess transport of exogenous FA. The addition of the CD36 inhibitor synergistically enhanced the anti-proliferative effects of the PI3K inhibitors.

Conclusion: Simultaneously targeting the PI3K signaling pathway and exogenous FA uptake could potentially be advantageous for patients with PTEN-loss anti-HER2 resistant breast cancer.

Background: In malignant melanoma, liver metastases significantly reduce survival, even despite highly effective new therapies. Given the increase in metabolic liver diseases such as metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), this study investigated the impact of liver sinusoidal endothelial cell (LSEC)-specific alterations in MASLD/MASH on hepatic melanoma metastasis.

Methods: Mice were fed a choline-deficient L-amino acid-defined (CDAA) diet for ten weeks to induce MASH-associated liver fibrosis, or a CDAA diet or a high fat diet (HFD) for shorter periods of time to induce early steatosis-associated alterations. Liver metastasis formation was assessed using melanoma cell lines B16F10Luc2 and Wt31. LSEC-specific GATA4 knockout mice (Gata4^LSEC-KO/BL) developing MASH-like liver fibrosis without steatosis via a pathogenic angiocrine switch were included to compare the impact of liver fibrosis versus hepatic steatosis on hepatic melanoma metastasis. Bulk RNA-Seq of isolated LSECs from CDAA-fed and control mice was performed. Levels of adhesion molecules (VCAM1, ICAM1, E-selectin) were monitored, and ICAM1 and VCAM1 antibody therapy was employed.

Results: Feeding a CDAA diet, in contrast to a HFD, led to increased metastasis before the development of liver fibrosis. Gata4^LSEC-KO/BL mice characterized by vascular changes ensuing perisinusoidal liver fibrosis without steatosis also exhibited increased metastasis. Early molecular alterations in the hepatic vascular niche, rather than fibrosis or steatosis, correlated with metastasis, as shown by LSEC dedifferentiation and upregulation of endothelial adhesion molecules. The metastatic process in CDAA-fed mice was also dependent on the respective melanoma cell lines used and on the route of their metastatic spread. ICAM1 inhibition, but not VCAM1 inhibition reduced melanoma cell retention.

Conclusion: We discovered that the hepatic vascular niche acts as a delicate sensor to even short-term nutritional alterations during the development of MASLD/MASH. The dynamic adaptations to the metabolic challenges of developing MASLD/MASH caused an early shift from the normal hepatic vascular niche to a pre-metastatic vascular niche that promoted hepatic melanoma metastasis in the context of cell-autonomous and acquired melanoma cell features. Altogether, our findings provide a potential avenue for angiotargeted therapies to prevent hepatic melanoma metastasis.