Cancer immunotherapy shows promising potential in future cancer treatment but unfortunately is clinically unsatisfactory due to the low therapeutic efficacy and the possible severe immunotoxicity. Here we show a combined magnetic hyperthermia therapy (MHT) and checkpoint blockade immunotherapy for both primary tumor ablation and mimetic metastatic tumor inhibition. Monodispersed, high-performance superparamagnetic CoFe2O4@MnFe2O4 nanoparticles were synthesized and used for effective MHT-induced thermal ablation of primary tumors. Simultaneously, numerous tumor-associated antigens were produced to promote the maturation and activation of dendritic cells (DCs) and cytotoxic T cells for effective immunotherapy of distant mimetic metastatic tumors in a tumor-bearing mice model. The combined MHT and checkpoint blockade immunotherapy demonstrate the great potentials in the fight against both primary and metastatic tumors.

No abstract

Distinctive from their normal counterparts, cancer cells exhibit unique metabolic dependencies on glutamine to fuel anabolic processes. Specifically, pancreatic ductal adenocarcinoma (PDAC) cells rely on an unconventional metabolic pathway catalyzed by aspartate aminotransferase, malate dehydrogenase 1 (MDH1), and malic enzyme 1 to rewire glutamine metabolism and support nicotinamide adenine dinucleotide phosphate (NADPH) production. Here, we report that methylation on arginine 248 (R248) negatively regulates MDH1. Protein arginine methyltransferase 4 (PRMT4/CARM1) methylates and inhibits MDH1 by disrupting its dimerization. Knockdown of MDH1 represses mitochondria respiration and inhibits glutamine metabolism, which sensitizes PDAC cells to oxidative stress and suppresses cell proliferation. Meanwhile, re-expression of wild-type MDH1, but not its methylation-mimetic mutant, protects cells from oxidative injury and restores cell growth and clonogenic activity. Importantly, MDH1 is hypomethylated at R248 in clinical PDAC samples. Our study reveals that arginine methylation of MDH1 by CARM1 regulates cellular redox homeostasis and suppresses glutamine metabolism of pancreatic cancer.

Metabolic reprogramming is an emerging hallmark of cancer cells, in which cancer cells exhibit distinct metabolic phenotypes to fuel their proliferation and progression. The significant advancements made in the area of metabolic reprogramming make possible new strategies for overcoming malignant cancer, including triple-negative breast cancer. Triple-negative breast cancer (TNBC) is associated with high histologic grade, aggressive phenotype, and poor prognosis. Even though triple-negative breast cancer patients benefit from standard chemotherapy, they still face high recurrence rates and are more likely to develop resistance to chemotherapeutic drugs. Therefore, there is an urgent need to explore vulnerabilities of triple-negative breast cancer and develop novel therapeutic drugs to improve clinical outcomes for triple-negative breast cancer patients. Metabolic reprogramming may provide promising therapeutic targets for the treatment of triple-negative breast cancer. In this paper, we primarily discuss how triple-negative breast cancer cells reprogram their metabolic phenotype and that of stromal cells in the microenvironment to survive under nutrient-poor conditions. Considering that metastasis and chemoresistance are the main contributors to mortality in triple-negative breast cancer patients, we also focus on the role of metabolic adaption in mediating metastasis and chemoresistance of triple-negative breast cancer tumors.

No abstract

Long noncoding RNAs (lncRNAs) are known to regulate the development and progression of various cancers. However, few lncRNAs have been well characterized in lung adenocarcinoma (LUAD). Here, we identified the expression profile of lncRNAs and protein-coding genes via microarrays analysis of paired LUAD tissues and adjacent non-tumor tissues from five female non-smokes with LUAD. A total of 498 lncRNAs and 1691 protein-coding genes were differentially expressed between LUAD tissues and paired adjacent normal tissues. A novel lncRNA, LUAD transcript 1 (LUADT1), which is highly expressed in LUAD and correlates with T stage, was characterized. Both in vitro and in vivo data showed that LUADT1 knockdown significantly inhibited proliferation of LUAD cells and induced cell cycle arrest at the G0–G1 phase. Further analysis indicated that LUADT1 may regulate cell cycle progression by epigenetically inhibiting the expression of p27. RNA immunoprecipitation and chromatin immunoprecipitation assays confirmed that LUADT1 binds to SUZ12, a core component of polycomb repressive complex 2, and mediates the trimethylation of H3K27 at the promoter region of p27. The negative correlation between LUADT1 and p27 expression was confirmed in LUAD tissue samples. These data suggested that a set of lncRNAs and protein-coding genes were differentially expressed in LUAD. LUADT1 is an oncogenic lncRNA that regulates LUAD progression, suggesting that dysregulated lncRNAs may serve as key regulatory factors in LUAD progression.

Increased aerobic glycolysis is a hallmark of cancer metabolism. How cancer cells coordinate glucose metabolism with extracellular glucose levels remains largely unknown. Here, we report that coactivator-associated arginine methyltransferase 1 (CARM1 or PRMT4) signals glucose availability to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and suppresses glycolysis in liver cancer cells. CARM1 methylates GAPDH at arginine 234 (R234), inhibiting its catalytic activity. Glucose starvation leads to CARM1 upregulation, further inducing R234 hypermethylation and GAPDH inhibition. The re-expression of wild-type GAPDH, but not of its methylation-mimetic mutant, sustains glycolytic levels. CARM1 inhibition increases glycolytic flux and glycolysis. R234 methylation delays tumor cell proliferation in vitro and in vivo. Compared with normal tissues, R234 is hypomethylated in malignant clinical hepatocellular carcinoma samples. Notably, R234 methylation positively correlates with CARM1 expression in these liver cancer samples. Our findings thus reveal that CARM1-mediated GAPDH methylation is a key regulatory mechanism of glucose metabolism in liver cancer.

Metabolic alteration is a hallmark of cancer. Dysregulation of methionine metabolism is implicated in human liver cancer. Methionine adenosyltransferase IIα (MAT IIα) is a key enzyme in the methionine cycle, catalysing the production of S-adenosylmethionine (SAM), a key methyl donor in cellular processes, and is associated with uncontrolled cell proliferation in cancer. Here we show that P300 acetylates MAT IIα at lysine residue 81 and destabilizes MAT IIα by promoting its ubiquitylation and subsequent proteasomal degradation. Conversely, histone deacetylase-3 deacetylates and stabilizes MAT IIα by preventing its proteasomal degradation. Folate deprivation upregulates K81 acetylation and destabilizes MAT IIα to moderate cell proliferation, whereas a single mutation at K81 reverses the proliferative disadvantage of cancer cells upon folate deprivation. Moreover, MAT IIα K81 acetylation is decreased in human hepatocellular cancer. Collectively, our study reveals a novel mechanism of MAT IIα regulation by acetylation and ubiquitylation, and a direct functional link of this regulation to cancer development.