Autophagy in Cancer: A Metabolic Perspective

Targeting the Warburg effect: A revisited perspective from molecular mechanisms to traditional and innovative therapeutic strategies in cancer

Cancer reprogramming is an important facilitator of cancer development and survival, with tumor cells exhibiting a preference for aerobic glycolysis beyond oxidative phosphorylation, even under sufficient oxygen supply condition. This metabolic alteration, known as the Warburg effect, serves as a significant indicator of malignant tumor transformation. The Warburg effect primarily impacts cancer occurrence by influencing the aerobic glycolysis pathway in cancer cells. Key enzymes involved in this process include glucose transporters (GLUTs), HKs, PFKs, LDHs, and PKM2. Moreover, the expression of transcriptional regulatory factors and proteins, such as FOXM1, p53, NF-κB, HIF1α, and c-Myc, can also influence cancer progression. Furthermore, lncRNAs, miRNAs, and circular RNAs play a vital role in directly regulating the Warburg effect. Additionally, gene mutations, tumor microenvironment remodeling, and immune system interactions are closely associated with the Warburg effect. Notably, the development of drugs targeting the Warburg effect has exhibited promising potential in tumor treatment. This comprehensive review presents novel directions and approaches for the early diagnosis and treatment of cancer patients by conducting in-depth research and summarizing the bright prospects of targeting the Warburg effect in cancer.

The protective role of Lactobacillus rhamnosus GG postbiotic on the alteration of autophagy and inflammation pathways induced by gliadin in intestinal models

Celiac disease (CD) is an autoimmune enteropathy caused by an abnormal immune response to gliadin peptides in genetically predisposed individuals. For people with CD, the only available therapy thus far is the lifelong necessity for a gluten-free diet (GFD). Innovative therapies include probiotics and postbiotics as dietary supplements, both of which may benefit the host. Therefore, the present study aimed to investigate the possible beneficial effects of the postbiotic Lactobacillus rhamnosus GG (LGG) in preventing the effects induced by indigested gliadin peptides on the intestinal epithelium. In this study, these effects on the mTOR pathway, autophagic function, and inflammation have been evaluated. Furthermore, in this study, we stimulated the Caco-2 cells with the undigested gliadin peptide (P31-43) and with the crude gliadin peptic-tryptic peptides (PTG) and pretreated the samples with LGG postbiotics (ATCC 53103) (1 × 108). In this study, the effects induced by gliadin before and after pretreatment have also been investigated. The phosphorylation levels of mTOR, p70S6K, and p4EBP-1 were increased after treatment with PTG and P31-43, indicating that the intestinal epithelial cells responded to the gliadin peptides by activating the mTOR pathway. Moreover, in this study, an increase in the phosphorylation of NF-κβ was observed. Pretreatment with LGG postbiotic prevented both the activation of the mTOR pathway and the NF-κβ phosphorylation. In addition, P31-43 reduced LC3II staining, and the postbiotic treatment was able to prevent this reduction. Subsequently, to evaluate the inflammation in a more complex intestinal model, the intestinal organoids derived from celiac disease patient biopsies (GCD-CD) and controls (CTR) were cultured. Stimulation with peptide 31-43 in the CD intestinal organoids induced NF-κβ activation, and pretreatment with LGG postbiotic could prevent it. These data showed that the LGG postbiotic can prevent the P31-43-mediated increase in inflammation in both Caco-2 cells and in intestinal organoids derived from CD patients.

Design, Synthesis and Antiproliferative Evaluation of Bis-Indole Derivatives with a Phenyl Linker: Focus on Autophagy

This work deals with the study of the synthesis of new bis-indole analogues with a phenyl linker derived from indole phytoalexins. Synthesis of target bis-indole thiourea linked by a phenyl linker was achieved by the reaction of [1-(tert-butoxycarbonyl)indol-3-yl]methyl isothiocyanate with p-phenylenediamine. By replacing the sulfur of the thiocarbonyl group in bis-indole thiourea with oxygen using mesityl nitrile oxide, a bis-indole homodimer with a urea group was obtained. A cyclization protocol utilizing bis-indole thiourea and methyl bromoacetate was applied to synthesize a bis-indole homodimer with a thiazolidin-4-one moiety. Bis-indole homodimers derived from 1-methoxyspirobrassinol methyl ether were prepared by bromospirocyclization methodology. Among the synthesized analogues, compound 49 was selected for further study. To evaluate the mode of the mechanism of action, we used flow cytometry, Western blot, and spectroscopic analyses. Compound 49 significantly inhibited the proliferation of lung cancer cell line A549 with minimal effects on the non-cancer cells. We also demonstrated that compound 49 induced autophagy through the upregulation of Beclin-1, LC3A/B, Atg7 and AMPK and ULK1. Furthermore, chloroquine (CQ; an autophagy inhibitor) in combination with compound 49 decreased cell proliferation and induced G1 cell cycle arrest and apoptosis. Compound 49 also caused GSH depletion and significantly potentiated the antiproliferative effect of cis-platin.