PIWIL1 Drives Chemoresistance in Multiple Myeloma by Modulating Mitophagy and the Myeloma Stem Cell Population

A comprehensive review on the role of PIWI-interacting RNA (piRNA) in gynecological cancers

Gynecological cancers are currently a major public health concern due to increase in incidence and mortality globally. PIWI-interacting RNA (piRNA) are small non-coding RNA consisting of 24-32 nucleotides that plays regulatory role by interacting with piwi family of protein. Recent studies have revealed that piRNAs are expressed in various kinds of human tissues and influences key signalling pathways at transcriptional and post transcriptional levels. Studies have also that suggested piRNA and PIWI proteins display frequently altered expression in several cancers. Recent research has indicated that abnormal expression of piRNA may play a significant role in development and progression of gynecological cancers. Clinical studies suggested that, abnormally expressed piRNAs may serve as diagnostic and prognostic marker, and as potential therapeutic targets in these cancers. In the present review article, we discussed the emerging role of piRNA and their utility as diagnostic and prognostic marker in gynecological cancers.

Mitophagy at the crossroads of cancer development: Exploring the role of mitophagy in tumor progression and therapy resistance

Preserving a functional mitochondrial network is crucial for cellular well-being, considering the pivotal role of mitochondria in ensuring cellular survival, especially under stressful conditions. Mitophagy, the selective removal of damaged mitochondria through autophagy, plays a pivotal role in preserving cellular homeostasis by preventing the production of harmful reactive oxygen species from dysfunctional mitochondria. While the involvement of mitophagy in neurodegenerative diseases has been thoroughly investigated, it is becoming increasingly evident that mitophagy plays a significant role in cancer biology. Perturbations in mitophagy pathways lead to suboptimal mitochondrial quality control, catalyzing various aspects of carcinogenesis, including establishing metabolic plasticity, stemness, metabolic reconfiguration of cancer-associated fibroblasts, and immunomodulation. While mitophagy performs a delicate balancing act at the intersection of cell survival and cell death, mounting evidence indicates that, particularly in the context of stress responses induced by cancer therapy, it predominantly promotes cell survival. Here, we showcase an overview of the current understanding of the role of mitophagy in cancer biology and its potential as a target for cancer therapy. Gaining a more comprehensive insight into the interaction between cancer therapy and mitophagy has the potential to reveal novel targets and pathways, paving the way for enhanced treatment strategies for therapy-resistant tumors in the near future.

Transcriptome Analysis Reveals the Involvement of Mitophagy and Peroxisome in the Resistance to QoIs in Corynespora cassiicola

Quinone outside inhibitor fungicides (QoIs) are crucial fungicides for controlling plant diseases, but resistance, mainly caused by G143A, has been widely reported with the high and widespread use of QoIs. However, two phenotypes of Corynespora casiicola (RI and RII) with the same G143A showed significantly different resistance to QoIs in our previous study, which did not match the reported mechanisms. Therefore, transcriptome analysis of RI and RII strains after trifloxystrobin treatment was used to explore the new resistance mechanism in this study. The results show that 332 differentially expressed genes (DEGs) were significantly up-regulated and 448 DEGs were significantly down-regulated. The results of GO and KEGG enrichment showed that DEGs were most enriched in ribosomes, while also having enrichment in peroxide, endocytosis, the lysosome, autophagy, and mitophagy. In particular, mitophagy and peroxisome have been reported in medicine as the main mechanisms of reactive oxygen species (ROS) scavenging, while the lysosome and endocytosis are an important organelle and physiological process, respectively, that assist mitophagy. The oxidative stress experiments showed that the oxidative stress resistance of the RII strains was significantly higher than that of the RI strains: specifically, it was more than 1.8-fold higher at a concentration of 0.12% H2O2. This indicates that there is indeed a significant difference in the scavenging capacity of ROS between the two phenotypic strains. Therefore, we suggest that QoIs' action caused a high production of ROS, and that scavenging mechanisms such as mitophagy and peroxisomes functioned in RII strains to prevent oxidative stress, whereas RI strains were less capable of resisting oxidative stress, resulting in different resistance to QoIs. In this study, it was first revealed that mitophagy and peroxisome mechanisms available for ROS scavenging are involved in the resistance of pathogens to fungicides.

Mechanism of action of Asparagus officinalis extract against multiple myeloma using bioinformatics tools, in silico and in vitro study

Introduction: Asparagus (Asparagus officinalis) is a perennial flowering plant species. Its main components have tumor-prevention, immune system-enhancement, and anti-inflammation effects. Network pharmacology is a powerful approach that is being applied increasingly to research of herbal medicines. Herb identification, study of compound targets, network construction, and network analysis have been used to elucidate how herbal medicines work. However, the interaction of bioactive substances from asparagus with the targets involved in multiple myeloma (MM) has not been elucidated. We explored the mechanism of action of asparagus in MM through network pharmacology and experimental verification. Methods: The active ingredients and corresponding targets of asparagus were acquired from the Traditional Chinese Medicine System Pharmacology database, followed by identification of MM-related target genes using GeneCards and Online Mendelian Inheritance in Man databases, which were matched with the potential targets of asparagus. Potential targets were identified and a target network of traditional Chinese medicine was constructed. The STRING database and Cytoscape were utilized to create protein-protein interaction (PPI) networks and further screening of core targets. Results: The intersection of target genes and core target genes of the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway was enriched, the top-five core target genes were selected, and the binding affinity of corresponding compounds to the top-five core targets was analyzed using molecular docking. Network pharmacology identified nine active components of asparagus from databases based on oral bioavailability and drug similarity, and predicted 157 potential targets related to asparagus. Enrichment analyses showed that "steroid receptor activity" and the "PI3K/AKT signaling pathway" were the most enriched biological process and signaling pathway, respectively. According to the top-10 core genes and targets of the PPI pathway, AKT1, interleukin (IL)-6, vascular endothelial growth factor (VEGF)A, MYC, and epidermal growth factor receptor (EGFR) were selected for molecular docking. The latter showed that five core targets of the PI3K/AKT signaling pathway could bind to quercetin, among which EGFR, IL-6, and MYC showed strong docking, and the diosgenin ligand could bind to VEGFA. Cell experiments showed that asparagus, through the PI3K/AKT/NF-κB pathway, inhibited the proliferation and migration of MM cells, and caused retardation and apoptosis of MM cells in the G0/G1 phase. Discussion: In this study, the anti-cancer activity of asparagus against MM was demonstrated using network pharmacology, and potential pharmacological mechanisms were inferred using in vitro experimental data.

The oncoprotein MUC1 facilitates breast cancer progression by promoting Pink1-dependent mitophagy via ATAD3A destabilization

Mitophagy is a vital process that controls mitochondria quality, dysregulation of which can promote cancer. Oncoprotein mucin 1 (MUC1) targets mitochondria to attenuate drug-induced apoptosis. However, little is known about whether and how MUC1 contributes to mitochondrial homeostasis in cancer cells. We identified a novel role of MUC1 in promoting mitophagy. Increased mitophagy is coupled with the translocation of MUC1 to mitochondria, where MUC1 interacts with and induces degradation of ATPase family AAA domain-containing 3A (ATAD3A), resulting in protection of PTEN-induced kinase 1 (Pink1) from ATAD3A-mediated cleavage. Interestingly, MUC1-induced mitophagy is associated with increased oncogenicity of cancer cells. Similarly, inhibition of mitophagy significantly suppresses MUC1-induced cancer cell activity in vitro and in vivo. Consistently, MUC1 and ATAD3A protein levels present an inverse relationship in tumor tissues of breast cancer patients. Our data validate that MUC1/ATAD3A/Pink1 axis-mediated mitophagy constitutes a novel mechanism for maintaining the malignancy of cancer cells, providing a novel therapeutic approach for MUC1-positive cancers.