bims-lymeca 2023-11-19 papers

bims-lymeca

Biomed News

on Lysosome metabolism in cancer

Issue of 2023–11–19
eight papers selected by
Harilaos Filippakis, University of New England

Ups and downs of lysosomal pH: conflicting roles of LAMP proteins?
Collapse of late endosomal pH elicits a rapid Rab7 response via V-ATPase and RILP.
Targeting PKD2 aggravates ferritinophagy-mediated ferroptosis via promoting autophagosome-lysosome fusion and enhances efficacy of carboplatin in lung adenocarcinoma.
The endosomal-lysosomal system in ADC design and cancer therapy.
Kinesin family member 18B activates mTORC1 signaling via actin gamma 1 to promote the recurrence of human hepatocellular carcinoma.
New tools can propel research in lysosomal storage diseases.
Local membrane source gathering by p62 body drives autophagosome formation.
Valproic acid reprograms the metabolic aberration of cisplatin treatment via ALDH modulation in triple-negative breast cancer cells.

Autophagy. 2023 Nov 14. 1-4

Ups and downs of lysosomal pH: conflicting roles of LAMP proteins?

Jonathan Handy, Gustavo C Macintosh, Andreas Jenny.

  The acidic pH of lysosomes is critical for catabolism in eukaryotic cells and is altered in neurodegenerative disease including Alzheimer and Parkinson. Recent reports using Drosophila and mammalian cell culture systems have identified novel and, at first sight, conflicting roles for the lysosomal associated membrane proteins (LAMPs) in the regulation of the endolysosomal system.Abbreviation: AD: Alzheimer disease; LAMP: lysosomal associated membrane protein; LTR: LysoTracker; PD: Parkinson disease; TMEM175: transmembrane protein 175; V-ATPase: vacuolar-type H+-translocating ATPase.

Keywords:  Alzheimer; Autophagy; LAMP proteins; Parkinson; lysosome; pH

DOI:  https://doi.org/10.1080/15548627.2023.2274253
bioRxiv. 2023 Oct 25. pii: 2023.10.24.563658. [Epub ahead of print]

Collapse of late endosomal pH elicits a rapid Rab7 response via V-ATPase and RILP.

R J Mulligan, M M Magaj, S Redemann, C C Yap, B Winckler.

Endosomal-lysosomal trafficking entails progressive acidification of endosomal compartments by the H + -V-ATPase to reach low lysosomal pH. Disruption of proper pH affects lysosomal function and the balance of protein synthesis and degradation (proteostasis). Disruption of endosomal pH also impairs endocytic maturation upstream of the lysosome. Using a lysosomal damage model (LLOMe), we identify the late endosomal small GTPase Rab7 as a rapid responder to endosomal/lysosomal pH neutralization. Luminal pH neutralization in LLOMe leads to increased assembly of the V 1 G 1 subunit of the V-ATPase on endosomal membranes and stabilization of Rab7 in the GTP-bound form. Rab7 stabilization is driven by a combination of pump assembly and the Rab7 effector RILP, while contributing to loss of late endosome tubulation and recycling of membrane receptors, like CI-M6PR. Our findings suggest a physiological cascade on late endosomes driven by V-ATPase assembly and Rab7 stabilization to counteract pH neutralization, and a novel model of how late endosomes broadly contribute to cellular stress responses, including LLOMe-mediated damage.
Summary: Using a lysosomal damage model, Mulligan et al. demonstrates that pH collapse in otherwise undamaged late endosomes leads to V-ATPase- and RILP-mediated hyperactivation of the small GTPase Rab7, disrupting normal late endosome tubulation behavior and biosynthetic receptor trafficking. These findings suggest a pH driven late endosomal stress response.

DOI: https://doi.org/10.1101/2023.10.24.563658
Chem Biol Interact. 2023 Nov 10. pii: S0009-2797(23)00461-1. [Epub ahead of print]387 110794

Targeting PKD2 aggravates ferritinophagy-mediated ferroptosis via promoting autophagosome-lysosome fusion and enhances efficacy of carboplatin in lung adenocarcinoma.

Yong Liu, Zhaofei Pang, Yadong Wang, Jichang Liu, Guanghui Wang, Jiajun Du.

  Ferroptosis is an iron-dependent cell death and affects efficacies of multiple antitumor regimens, showing a great potential in cancer therapy. Protein kinase D2 (PKD2) plays a crucial role in regulating necrosis and apoptosis. However, the relationship of PKD2 and ferroptosis is still elusive. In this study, we mainly analyzed the roles of PKD2 on ferroptosis and chemotherapy in lung adenocarcinoma (LUAD). We found PKD2 was highly expressed in LUAD and silencing PKD2 could promote erastin-induced reactive oxygen species (ROS), malondialdehyde (MDA) accumulation, intracellular iron content and LUAD cells death. Mechanistically, augmenting PKD2 could prevent autophagic degradation of ferritin, which could be impaired by bafilomycin A1. We further found that PKD2 overexpression would promote LC3B-II, p62/SQSTM1 accumulation and block autophagosome-lysosome fusion in a TFEB-independent manner, which could be impaired by bafilomycin A1. Bafilomycin A1 stimulation could weaken ferroptosis promotion by PKD2 abrogation. Silencing ferritin heavy chain-1 (FTH1) could reverse the resistance to ferroptosis by PKD2 overexpression. Additionally, in vitro and vivo experiments validated PKD2 promoted proliferation, migration and invasion of LUAD cells. PKD2 knockdown or pharmacological inhibition by CRT0066101 could enhance efficacy of carboplatin in LUAD via ferroptosis and apoptosis. Collectively, our study revealed that abrogation of PKD2 could aggravate ferritinophagy-mediated ferroptosis by promoting autophagosome-lysosome fusion and enhance efficacy of carboplatin in LUAD. Targeting PKD2 to induce ferroptosis may be a promising strategy for LUAD therapy.

Keywords:  Autophagy; Ferroptosis; Lung adenocarcinoma; Protein kinase D2; Reactive oxygen species

DOI:  https://doi.org/10.1016/j.cbi.2023.110794
Expert Opin Biol Ther. 2023 Nov 18.

The endosomal-lysosomal system in ADC design and cancer therapy.

Jeffrey V Leyton.

   INTRODUCTION: This discourse delves into the intricate connections between the endosomal-lysosomal system and antibody-drug conjugates (ADCs), shedding light on an essential yet less understood dimension of targeted therapy. While ADCs have revolutionized cancer treatment, resistance remains a formidable challenge, often involving diverse and overlapping mechanisms.
AREAS COVERED: This discourse highlights the roles of various components within the endosomal machinery, including Rab proteins, in ADC resistance development. It also explores how the transferrin-transferrin receptor and epidermal growth factor-epidermal growth factor receptor complexes, known for their roles in recycling and degradation process, respectively, can offer valuable insights for ADC design. Selected strategies to enhance lysosomal targeting are discussed, and potentially offer solutions to improve ADC efficacy.
EXPERT OPINION: By harnessing these different insights that connect ADCs with the endosomal-lysosomal system, the field may benefit to shape the next-generation of ADC design for increased efficacy and improved patient outcomes.

Keywords:  Antibody-drug conjugates; Rab proteins; endosome; epidermal growth factor receptor; internalization; lysosome; plasma membrane; transferrin receptor

DOI:  https://doi.org/10.1080/14712598.2023.2285996
Oncogenesis. 2023 Nov 13. 12(1): 54

Kinesin family member 18B activates mTORC1 signaling via actin gamma 1 to promote the recurrence of human hepatocellular carcinoma.

Qian Li, Mengqing Sun, Yao Meng, Mengqing Feng, Menglan Wang, Cunjie Chang, Heng Dong, Fangtian Bu, Chao Xu, Jing Liu, Qi Ling, Yiting Qiao, Jianxiang Chen.

The mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway is frequently reported to be hyperactivated in hepatocellular carcinoma (HCC) and contributes to HCC recurrence. However, the underlying regulatory mechanisms of mTORC1 signaling in HCC are not fully understood. In the present study, we found that the expression of kinesin family member 18B (KIF18B) was positively correlated with mTORC1 signaling in HCC, and the upregulation of KIF18B and p-mTOR was associated with a poor prognosis and HCC recurrence. Utilizing in vitro and in vivo assays, we showed that KIF18B promoted HCC cell proliferation and migration through activating mTORC1 signaling. Mechanistically, we identified Actin gamma 1 (γ-Actin) as a binding partner of KIF18B. KIF18B and γ-Actin synergistically modulated lysosome positioning, promoted mTORC1 translocation to lysosome membrane, and prohibited p70 S6K from entering lysosomes for degradation, which finally led to the enhancement of mTORC1 signaling transduction. Moreover, we found that KIF18B was a direct target of Forkhead box M1, which explains the potential mechanism of KIF18B overexpression in HCC. Our study highlights the potential of KIF18B as a therapeutic target for the treatment of HCC.

DOI: https://doi.org/10.1038/s41389-023-00499-7
Mol Genet Metab. 2023 Nov 03. pii: S1096-7192(23)00359-1. [Epub ahead of print]140(4): 107729

New tools can propel research in lysosomal storage diseases.

Ellen Hertz, Logan M Glasstetter, Yu Chen, Ellen Sidransky.

  Historically, the clinical manifestations of lysosomal storage diseases offered an early glimpse into the essential digestive functions of the lysosome. However, it was only recently that the more subtle role of this organelle in the dynamic regulation of multiple cellular processes was appreciated. With the need for precise interrogation of lysosomal interplay in health and disease comes the demand for more sophisticated functional tools. This demand has recently been met with 1) induced pluripotent stem cell-derived models that recapitulate the disease phenotype in vitro, 2) methods for lysosome affinity purification coupled with downstream omics analysis that provide a high-resolution snapshot of lysosomal alterations, and 3) gene editing and CRISPR/Cas9-based functional genomic strategies that enable screening for genetic modifiers of the disease phenotype. These emerging methods have garnered much interest in the field of neurodegeneration and their use in the field of metabolic disorders is now also steadily gaining momentum. Looking forward, these robust tools should accelerate basic science efforts to understand lysosomal dysfunction distal to substrate accumulation and provide translational opportunities to identify disease-modifying therapies.

Keywords:  CRISPR; Induced pluripotent stem cells (iPSC); Lyso-IP; Lysosomal storage diseases; Lysosome

DOI:  https://doi.org/10.1016/j.ymgme.2023.107729
Nat Commun. 2023 Nov 13. 14(1): 7338

Local membrane source gathering by p62 body drives autophagosome formation.

Xuezhao Feng, Daxiao Sun, Yanchang Li, Jinpei Zhang, Shiyu Liu, Dachuan Zhang, Jingxiang Zheng, Qing Xi, Haisha Liang, Wenkang Zhao, Ying Li, Mengbo Xu, Jiayu He, Tong Liu, Ayshamgul Hasim, Meisheng Ma, Ping Xu, Na Mi.

Autophagosomes are double-membrane vesicles generated intracellularly to encapsulate substrates for lysosomal degradation during autophagy. Phase separated p62 body plays pivotal roles during autophagosome formation, however, the underlying mechanisms are still not fully understood. Here we describe a spatial membrane gathering mode by which p62 body functions in autophagosome formation. Mass spectrometry-based proteomics reveals significant enrichment of vesicle trafficking components within p62 body. Combining cellular experiments and biochemical reconstitution assays, we confirm the gathering of ATG9 and ATG16L1-positive vesicles around p62 body, especially in Atg2ab DKO cells with blocked lipid transfer and vesicle fusion. Interestingly, p62 body also regulates ATG9 and ATG16L vesicle trafficking flux intracellularly. We further determine the lipid contents associated with p62 body via lipidomic profiling. Moreover, with in vitro kinase assay, we uncover the functions of p62 body as a platform to assemble ULK1 complex and invigorate PI3KC3-C1 kinase cascade for PI3P generation. Collectively, our study raises a membrane-based working model for multifaceted p62 body in controlling autophagosome biogenesis, and highlights the interplay between membraneless condensates and membrane vesicles in regulating cellular functions.

DOI: https://doi.org/10.1038/s41467-023-42829-8
Front Cell Dev Biol. 2023 ;11 1217149

Valproic acid reprograms the metabolic aberration of cisplatin treatment via ALDH modulation in triple-negative breast cancer cells.

Avital Granit Mizrahi, Ahinoam Gugenheim, Haneen Hamad, Roa'a Hamed, Nino Tetro, Ofra Maimon, Salome Khutsurauli, Hovav Nechushtan, Benjamin Nisman, Deborah Duran, Widad Samman, Liron Birimberg-Schwartz, Myriam Grunewald, Sara Eyal, Tamar Peretz.

  We recently demonstrated that the histone deacetylase inhibitor valproic acid (VPA) reprograms the cisplatin-induced metabolome of triple-negative breast cancer (TNBC) cells, including a shift in hexose levels. Accordingly, here, we tested the hypothesis that VPA alters glucose metabolism in correlation with cisplatin sensitivity. Two TNBC cell lines, MDA-MB-231 (a cisplatin-resistant line) and MDA-MB-436 (a cisplatin-sensitive line), were analyzed. The glycolysis and oxidative metabolism were measured using the Glycolysis Stress Test kit. The expression of aldehyde dehydrogenases (ALDHs), enzymes linked to drug resistance, was investigated by Western blot and real-time PCR analyses. We additionally studied the influence of ALDH inhibition by disulfiram on the viability of MDA-MB-231 cells and on a TNBC patient-derived organoid system. Cisplatin treatment reduced the extracellular acidification rate in MDA-MB-436 cells but not MDA-MB-231 cells, whereas VPA addition increased the extracellular acidification rate in both cell lines. VPA further reduced the oxygen consumption rate of cisplatin-treated MDA-MB-436 cells, which correlated with cell cycle alterations. However, in MDA-MB-231 cells, the cell cycle distribution did not change between cisplatin/VPA-cisplatin treatments. In both cell lines, VPA increased the expression of ALDH isoform and ALDH1A1 expression. However, only in MDA-MB-231 cells, VPA synergized with cisplatin to augment this effect. Disulfiram sensitized the cells to the cytotoxic effects of the VPA-cisplatin combination. Furthermore, the disulfiram-VPA-chemotherapy combination was most effective in TNBC organoids. Our results show that ALDH overexpression may act as one mechanism of cellular resistance to VPA in TNBC and that its inhibition may enhance the therapeutic efficacy of VPA-chemotherapeutic drug combinations.

Keywords:  ALDH; GLUT1; aldehyde dehydrogenase; cisplatin; disulfiram; glucose; metabolism; valproic acid

DOI:  https://doi.org/10.3389/fcell.2023.1217149