Blocking fatty acid synthesis reduces lung tumor growth in mice

Deformable nanocarriers for enhanced drug delivery and cancer therapy

Recently, the field of nanomedicine has witnessed substantial advancements in the development of nanocarriers for targeted drug delivery, emerges as promising platforms to enhance therapeutic efficacy and minimize adverse effects associated with conventional chemotherapy. Notably, deformable nanocarriers have garnered considerable attention due to their unique capabilities of size changeable, tumor-specific aggregation, stimuli-triggered disintegration, and morphological transformations. These deformable nanocarriers present significant opportunities for revolutionizing drug delivery strategies, by responding to specific stimuli or environmental cues, enabling achieved various functions at the tumor site, including size-shrinkage nanocarriers enhance drug penetration, aggregative nanocarriers enhance retention effect, disintegrating nanocarriers enable controlled drug release, and shape-changing nanocarriers improve cellular uptake, allowing for personalized treatment approaches and combination therapies. This review provides an overview of recent developments and applications of deformable nanocarriers for enhancing tumor therapy, underscores the diverse design strategies employed to create deformable nanocarriers and elucidates their remarkable potential in targeted tumor therapy.

Non-Specific Elevated Serum Free Fatty Acids in Lung Cancer Patients: Nutritional or Pathological?

IMPORTANCE

The reprogramming of lipid metabolism is a significant feature of tumors, yet the circulating levels of fatty acids in lung cancer patients remain to be explored. Moreover, the association between fatty acid levels and related factors, including nutritional intake, tumor metabolism, and tumor immunity, has been rarely discussed.

OBJECTIVES

To explore the differences in serum free fatty acids between lung cancer patients and healthy controls, and investigate the factors associated with this phenomenon.

DESIGN AND PARTICIPANTS

A case-control study enrolled 430 primary lung cancer patients and 430 healthy controls. The whole population had a medium [Q1, Q3] age of 48.0 [37.0, 58.9] years, with females comprising 56% of the participants. The absolute quantification of 27 serum free fatty acids (FFAs) was measured using a liquid chromatography-mass spectrometry (LC-MS/MS) detection. Data, including dietary intake, blood indicators, and gene expression of lung tissues, were obtained from questionnaires, blood tests, and RNA-sequencing. Statistical differences in FFA levels between lung cancer patients and healthy controls were investigated, and related contributing factors were explored.

RESULTS

Levels of 22 FFAs were significantly higher in lung cancer patients compared to those in healthy controls, with fold changes ranging from 1.14 to 1.69. Lung cancer diagnosis models built with clinical and FFA features yielded an area under the receiver operating characteristic curve (AUROC) of 0.830 (0.780-0.880). Total fatty acids (TFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) showed no significant dietary-serum associations, indicating that the elevations might not be attributed to an excessive intake of relevant fatty acids from the diet. For RNA-sequencing of lung tissues, among the 68 lipid metabolism genes, 26 genes showed significant upregulation (FDR < 0.05), while 33 genes exhibited significant downregulation, indicating the involvement of the fatty acids in the tumor metabolism. Through joint analysis with immune cells and inflammatory factors in the blood, fatty acids might exert suppressing effects on tumor immunity.

CONCLUSIONS

Lung cancer patients had elevated levels of serum free fatty acids compared to healthy individuals. The elevations might not be attributed to an excessive intake of relevant fatty acids from the diet but related to pathological factors of tumor metabolism and immunity. These findings will complement research on fatty acid metabolism of lung cancer and provide insights into potential intervention targets.

Construction of a prognostic model via WGCNA combined with the LASSO algorithm for stomach adenocarcinoma patients

Objective

This study aimed to identify prognostic signatures to predict the prognosis of patients with stomach adenocarcinoma (STAD), which is necessary to improve poor prognosis and offer possible treatment strategies for STAD patients.

Methods

The overlapping genes between the key model genes that were screened by the weighted gene co-expression network analysis (WGCNA) and differentially expressed genes (DEGs) whose expression was different with significance between normal and tumor tissues were extracted to serve as co-expression genes. Then, enrichment analysis was performed on these genes. Furthermore, the least absolute shrinkage and selection operator (LASSO) regression was performed to screen the hub genes among overlapping genes. Finally, we constructed a model to explore the influence of polygenic risk scores on the survival probability of patients with STAD, and interaction effect and mediating analyses were also performed.

Results

DEGs included 2,899 upregulated genes and 2,896 downregulated genes. After crossing the DEGs and light-yellow module genes that were obtained by WGCNA, a total of 39 overlapping genes were extracted. The gene enrichment analysis revealed that these genes were enriched in the prion diseases, biosynthesis of unsaturated fatty acids, RNA metabolic process, hydrolase activity, etc. PIP5K1P1, PTTG3P, and SNORD15B were determined by LASSO-Cox. The prognostic prediction of the three-gene model was established. The Cox regression analysis showed that the comprehensive risk score for three genes was an independent prognosis factor.

Conclusion

PIP5K1P1, PTTG3P, and SNORD15B are related to the prognosis and overall survival of patients. The three-gene risk model constructed has independent prognosis predictive ability for STAD.

EMT Factors and Metabolic Pathways in Cancer

The epithelial-mesenchymal transition (EMT) represents a biological program during which epithelial cells lose their cell identity and acquire a mesenchymal phenotype. EMT is normally observed during organismal development, wound healing and tissue fibrosis. However, this process can be hijacked by cancer cells and is often associated with resistance to apoptosis, acquisition of tissue invasiveness, cancer stem cell characteristics, and cancer treatment resistance. It is becoming evident that EMT is a complex, multifactorial spectrum, often involving episodic, transient or partial events. Multiple factors have been causally implicated in EMT including transcription factors (e.g., SNAIL, TWIST, ZEB), epigenetic modifications, microRNAs (e.g., miR-200 family) and more recently, long non-coding RNAs. However, the relevance of metabolic pathways in EMT is only recently being recognized. Importantly, alterations in key metabolic pathways affect cancer development and progression. In this review, we report the roles of key EMT factors and describe their interactions and interconnectedness. We introduce metabolic pathways that are involved in EMT, including glycolysis, the TCA cycle, lipid and amino acid metabolism, and characterize the relationship between EMT factors and cancer metabolism. Finally, we present therapeutic opportunities involving EMT, with particular focus on cancer metabolic pathways.

Prolyl isomerase Pin1 binds to and stabilizes acetyl CoA carboxylase 1 protein, thereby supporting cancer cell proliferation

The prolyl isomerase Pin1 expression level is reportedly increased in most malignant tissues and correlates with poor outcomes. On the other hand, acetyl CoA carboxylase 1 (ACC1), the rate limiting enzyme of lipogenesis is also abundantly expressed in cancer cells, to satisfy the demand for the fatty acids (FAs) needed for rapid cell proliferation. We found Pin1 expression levels to correlate positively with ACC1 levels in human prostate cancers, and we focused on the relationship between Pin1 and ACC1. Notably, it was demonstrated that Pin1 associates with ACC1 but not with acetyl CoA carboxylase 2 (ACC2) in the overexpression system as well as endogenously in the prostate cancer cell line DU145. This association is mediated by the WW domain in the Pin1 and C-terminal domains of ACC1. Interestingly, Pin1 deficiency or treatment with Pin1 siRNA or the inhibitor juglone markedly reduced ACC1 protein expression without affecting its mRNA level, while Pin1 overexpression increased the ACC1 protein level. In addition, chloroquine treatment restored the levels of ACC1 protein reduced by Pin1 siRNA treatment, indicating that Pin1 suppressed ACC1 degradation through the lysosomal pathway. In brief, we have concluded that Pin1 leads to the stabilization of and increases in ACC1. Therefore, it is likely that the growth-enhancing effect of Pin1 in cancer cells is mediated at least partially by the stabilization of ACC1 protein, corresponding to the well-known potential of Pin1 inhibitors as anti-cancer drugs.

How the Warburg effect supports aggressiveness and drug resistance of cancer cells?

Cancer cells employ both conventional oxidative metabolism and glycolytic anaerobic metabolism. However, their proliferation is marked by a shift towards increasing glycolytic metabolism even in the presence of O₂ (Warburg effect). HIF1, a major hypoxia induced transcription factor, promotes a dissociation between glycolysis and the tricarboxylic acid cycle, a process limiting the efficient production of ATP and citrate which otherwise would arrest glycolysis. The Warburg effect also favors an intracellular alkaline pH which is a driving force in many aspects of cancer cell proliferation (enhancement of glycolysis and cell cycle progression) and of cancer aggressiveness (resistance to various processes including hypoxia, apoptosis, cytotoxic drugs and immune response). This metabolism leads to epigenetic and genetic alterations with the occurrence of multiple new cell phenotypes which enhance cancer cell growth and aggressiveness. In depth understanding of these metabolic changes in cancer cells may lead to the development of novel therapeutic strategies, which when combined with existing cancer treatments, might improve their effectiveness and/or overcome chemoresistance.

Remodeling the blood-brain barrier microenvironment by natural products for brain tumor therapy

Brain tumor incidence shows an upward trend in recent years; brain tumors account for 5% of adult tumors, while in children, this figure has increased to 70%. Moreover, 20%-30% of malignant tumors will eventually metastasize into the brain. Both benign and malignant tumors can cause an increase in intracranial pressure and brain tissue compression, leading to central nervous system (CNS) damage which endangers the patients' lives. Despite the many approaches to treating brain tumors and the progress that has been made, only modest gains in survival time of brain tumor patients have been achieved. At present, chemotherapy is the treatment of choice for many cancers, but the special structure of the blood-brain barrier (BBB) limits most chemotherapeutic agents from passing through the BBB and penetrating into tumors in the brain. The BBB microenvironment contains numerous cell types, including endothelial cells, astrocytes, peripheral cells and microglia, and extracellular matrix (ECM). Many chemical components of natural products are reported to regulate the BBB microenvironment near brain tumors and assist in their treatment. This review focuses on the composition and function of the BBB microenvironment under both physiological and pathological conditions, and the current research progress in regulating the BBB microenvironment by natural products to promote the treatment of brain tumors.

Lipid Synthesis Is a Metabolic Liability of Non-Small Cell Lung Cancer

The renaissance in the study of cancer metabolism has refocused efforts to identify and target metabolic dependencies of tumors as an approach for cancer therapy. One of the unique metabolic requirements that cancer cells possess to sustain their biosynthetic growth demands is altered fatty acid metabolism, in particular the synthesis of de novo fatty acids that are required as cellular building blocks to support cell division. Enhanced fatty acid synthesis that is observed in many tumor types has been postulated to open a therapeutic window for cancer therapy and, correspondingly, efforts to pharmacologically inhibit key enzymes of fatty acid synthesis are being pursued. However, despite these efforts, whether inhibition of fatty acid synthesis stunts tumor growth in vivo has been poorly understood. In this review, we focus on the recent evidence that pharmacologic inhibition of acetyl-CoA carboxylase, the enzyme that regulates the rate-limiting step of de novo fatty acid synthesis, exposes a metabolic liability of non-small cell lung cancer and represses tumor growth in preclinical models.