Cell Death & Disease最新文献

Retinoblastoma (RB) is an intraocular tumor arising from retinal cone progenitor cells affecting young children. In the last couple of years, RB treatment evolved towards eye preserving therapies. Therefore, investigating intratumoral differences and the RB tumor microenvironment (TME), regulating tumorigenesis and metastasis, is crucial. How RB cells and their TME are involved in tumor development needs to be elucidated using in vitro models including RB derived stromal cells. In the study presented, we established primary RB derived tumor and stromal cell cultures and compared them by RNAseq analysis to identify their gene expression signatures. RB tumor cells cultivated in serum containing medium were more differentiated compared to RB tumor cells grown in serum-free medium displaying a stem cell like phenotype. In addition, we identified differentially expressed genes for RB tumor and stromal derived cells. Furthermore, we immortalized cells of a RB1 mutated, MYCN amplified and trefoil factor family peptid 1 (TFF1) positive RB tumor and RB derived non-tumor stromal tissue. We characterized both immortalized cell lines using a human oncology proteome array, immunofluorescence staining of different markers and in vitro cell growth analyses. Tumor formation of the immortalized RB tumor cell line was investigated in a chicken chorioallantoic membrane (CAM) model. Our studies revealed that the RB stromal derived cell line comprises tumor associated macrophages (TAMs), glia and cancer associated fibroblasts (CAFs), we were able to successfully separate via magnetic cell separation (MACS). For co-cultivation studies, we established a 3D spheroid model with RB tumor and RB derived stromal cells. In summary, we established an in vitro model system to investigate the interaction of RB tumor cells with their TME. Our findings contribute to a better understanding of the relationship between RB tumor malignancy and its TME and will facilitate the development of effective treatment options for eye preserving therapies.

Mitochondrial dysfunction is a central aspect of Parkinson's disease (PD) pathology, yet the underlying mechanisms are not fully understood. This study investigates the link between α-Synuclein (α-Syn) pathology and the loss of translocase of the outer mitochondrial membrane 40 (TOM40), unraveling its implications for mitochondrial dysfunctions in neurons. We discovered that TOM40 protein depletion occurs in the brains of patients with Guam Parkinsonism-Dementia (Guam PD) and cultured neurons expressing α-Syn proteinopathy, notably, without corresponding changes in TOM40 mRNA levels. Cultured neurons expressing α-Syn mutants, with or without a mitochondria-targeting signal (MTS) underscores the role of α-Syn's mitochondrial localization in inducing TOM40 degradation. PDe-related etiological factors, such as 6-hydroxydopamine or ROS/metal ions stress, which promotes α-Syn oligomerization, exacerbate TOM40 depletion in PD patient-derived cells with SNCA gene triplication. Although α-Syn interacts with both TOM40 and TOM20 in the outer mitochondrial membrane, degradation is selective for TOM40, which occurs via the ubiquitin-proteasome system (UPS) pathway. Our comprehensive analyses using Seahorse technology, mitochondrial DNA sequencing, and damage assessments, demonstrate that mutant α-Syn-induced TOM40 loss results in mitochondrial dysfunction, characterized by reduced membrane potential, accumulation of mtDNA damage, deletion/insertion mutations, and altered oxygen consumption rates. Notably, ectopic supplementation of TOM40 or reducing pathological forms of α-Syn using ADP-ribosylation inhibitors ameliorate these mitochondrial defects, suggesting potential therapeutic avenues. In conclusion, our findings provide crucial mechanistic insights into how α-Syn accumulation leads to TOM40 degradation and mitochondrial dysfunction, offering insights for targeted interventions to alleviate mitochondrial defects in PD.

Colorectal cancer (CRC) is the third most common cancer diagnosed and the second leading cause of cancer-related deaths. Emerging evidence has indicated that long non-coding RNAs (lncRNAs) are involved in the progression of various types of cancer. In this study, we aimed to identify potential causal lncRNAs in CRC through comprehensive multilevel bioinformatics analyses, coupled with functional validation. Our bioinformatics analyses identified LINC02257 as being highly expressed in CRC, and associated with poor survival and advanced tumor stages among patients with CRC. Genome-wide association analysis revealed significant associations between variants near LINC02257 and CRC, suggesting a causal role for LINC02257 in CRC. Network analysis identified LINC02257 as playing a key role in the epithelial-mesenchymal transition pathway. Single-cell RNA sequencing showed that elevated expression of LINC02257 was associated with a reduced proportion of epithelial cells. In vitro experiments showed that LINC02257 positively regulated the metastatic and proliferative potential of CRC cells. Mechanistically, LINC02257 affected CRC malignancy by functioning as a competitive endogenous RNA of microRNAs and RNA-binding proteins. LINC02257 upregulated SERPINE1 by sequestering tumor suppressive miR-1273g-3p, thereby increasing metastatic and proliferative abilities of CRC cells. Additionally, LINC02257 directly interacted with YB1 and induced its phosphorylation, thereby facilitating YB1 nuclear translocation. The transcriptional activation of YB1 target genes was associated with the oncogenic functions of LINC02257. Taken together, our results demonstrate LINC02257 as a promising therapeutic target for CRC treatment.

Bladder cancer (BC) is the second most prevalent genitourinary malignancy worldwide. Despite recent approvals of immune checkpoint inhibitors and targeted therapy for muscle invasive or recurrent BC, options remain limited for patients with non-muscle invasive BC (NMIBC) refractory to Bacillus Calmette-Guérin (BCG) and chemotherapy. NMIBC is more frequently classified as a luminal subtype, in which increased PPARγ activity is a key feature in promoting tumor growth and evasion of immunosurveillance. Cinobufotalin is one of the major compound of bufadienolides, the primary active components of toad venom that has been utilized in the clinical treatment of cancer. We herein focused on cinobufotalin, examining its anticancer activity and molecular mechanisms in luminal-type NMIBC. Our results newly reveal that cinobufotalin strongly suppresses the viability and proliferation of luminal BC cells with minimal cytotoxic effects on normal uroepithelial cells, and exhibits significant antitumor activity in a RT112 xenograft BC model. Mechanistically, our sub-G1-phase cell accumulation, Annexin V staining, caspase-3/8/9 activation, and PARP activation analyses show that cinobufotalin induces apoptosis in luminal-type BC cells. Cinobufotalin significantly inhibited the levels of PPARγ and its downstream targets, as well as lipid droplet formation and free fatty acid levels in RT112 cells. PPARγ overexpression rescued RT112 cells from cinobufotalin-induced apoptosis and mitigated the downregulation of FASN and PLIN4. Finally, we show seemingly for the first time that cinobufotalin promotes SIAH1/2-mediated proteasomal degradation of PPARγ in luminal BC cells. Together, these findings compellingly support the idea that cinobufotalin could be developed as a promising therapeutic agent for treating luminal-type NMIBC.

Colorectal cancer is a common malignant tumor, whose growth and metastasis are influenced by numerous factors. MicroRNAs have garnered increasing attention in recent years due to their involvement in tumor development. Exosomes are involved in intercellular signaling and influence tumor development by promoting tumor cell proliferation and metastasis through activation of angiogenesis and other mechanisms. This study aimed to investigate how the exosomes containing miR-320d from colorectal cancer (CRC) cells promote colorectal cancer metastasis by regulating angiogenesis. CRC-derived exosomes containing miR-320d can be transferred to vascular endothelial cells, facilitating their proliferation, invasion, migration, and angiogenesis. By targeting GNAI1, miR-320d in these exosomes reduces GNAI1 levels in endothelial cells, causing more JAK2/STAT3 activation and VEGFA production. This ultimately enhances the migration and angiogenic capacity of vascular endothelial cells. Moreover, CRC patients with high levels of miR-320d in their blood respond better to treatment with bevacizumab. In vivo experiments further proved the role of miR-320d from CRC exosomes in increasing tumor size, blood vessel formation, and the spread of cancer to the liver. In this study, we have demonstrated that exosomal miR-320d promotes cancer cell metastasis and enhances angiogenesis by downregulating GNAI1 expression and enhancing JAK2/STAT3.

Drug resistance and recurrence are still the bottlenecks in the clinical treatment of ovarian cancer (OC), seriously affecting patients' prognosis. Therefore, it is an urgent challenge for OC to be overcome towards precision therapy by studying the mechanism of OC drug resistance, finding new drug resistance targets and developing new effective treatment strategies. In this study, we found that lncRNA LOC730101 played an essential role in attenuating drug resistance in OC. LOC730101 was significantly down-regulated in platinum-resistant ovarian cancer tissues, and ectopic overexpression of LOC730101 substantially increased chemotherapy-induced apoptosis. Mechanistically, LOC730101 specifically binds to BECN1 and inhibits the formation of autophagosome BECN1/VPS34 by reducing phosphorylation of BECN1, thereby inhibiting autophagy and promoting drug sensitivity in ovarian cancer cells following treatment with cisplatin and PARP inhibitors. Moreover, LOC730101 inhibits the expression and activity of RNF168 via p62, which in turn affects H2A ubiquitination-mediated DNA damage repair and promotes drug sensitivity in ovarian cancer cells. Our findings demonstrated that LOC730101 played an important role in regulating the formation of the autophagic complex and that inhibition of autophagy significantly enhances the drug sensitivity of OC. And LOC730101 may be used as a prognostic marker to predict the sensitivity of OC to platinum and PARP inhibitors.

The Triple-Negative Breast Cancer (TNBC) subtype constitutes 15-20% of breast cancer cases and is associated with the poorest clinical outcomes. Distant metastasis, particularly to the lungs, is a major contributor to the high mortality rates in breast cancer patients. Despite this, there has been a lack of comprehensive insights into the heterogeneity of metastatic tumors and their surrounding ecosystem in the lungs. In this study, we utilized spatial RNA sequencing technology to investigate the heterogeneity of lung metastatic tumors and their microenvironment in two spontaneous lung metastatic mouse models. Our findings revealed an increase in metabolic-related genes within the cancer cells, with the hub gene Dlat (Dihydrolipoamide S-Acetyltransferase) showing a significant association with the development of lung metastatic tumors. Upregulation of Dlat led to the reprogramming of fatty acid utilization, markedly enhancing the bioenergetic capacity of cancer cells. This finding was corroborated by the increased dependence on fatty acid utilization in lung metastatic cancer cells, and inhibition of Dlat in breast cancer cells exhibited a reduced oxygen consumption rate. Consequently, inhibition of Dlat resulted in decreased survival capacity of breast cancer by reducing cancer stem cell properties and cell adhesion in the lung in vivo. The three cell components within the lung metastatic niche, including CD163⁺ macrophages, neutrophils, and endothelial cells, expressed elevated levels of ApoE, leading to the secretion of various protumorigenic molecules that promote cancer cell growth in the lung. These molecules include galectin-1, S100A10, S100A4, and S100A6. Collectively, our findings highlight the lipid metabolism reprogramming of cancer and components of the tumor microenvironment that support lung metastasis of TNBC breast cancer.

Neuronal necroptosis appears to be suppressed by the deubiquitinating enzyme A20 and is capable to regulate the polarization of microglia/macrophages after cerebral ischemia. We have demonstrated that hypoxic preconditioning (HPC) can alleviate receptor interacting protein 3 (RIP3)-induced necroptosis in CA1 after transient global cerebral ischemia (tGCI). However, it is still unclear whether HPC serves to regulate the phenotypic polarization of microglia/macrophages after cerebral ischemia by mitigating neuronal necroptosis. We hence aim to elucidate the underlying mechanism(s) by which the ubiquitination of RIP3-dependent necroptosis regulated by A20 affects microglia/macrophages phenotype after cerebral ischemic tolerance. We found that microglia/macrophages in CA1 of rats underwent M1 and M2 phenotypic polarization in response to tGCI. Notably, the treatment with HPC, as well as inhibitors of necroptosis, including Nec-1 and mixed lineage kinase domain-like (MLKL) siRNA, attenuated neuroinflammation associated with M1 polarization of microglia/macrophages induced by tGCI. Mechanistically, HPC was revealed to upregulate A20 and in turn enhance the interaction between A20 and RIP3, thereby reducing K63-linked polyubiquitination of RIP3 in CA1 after tGCI. Consequently, RIP3-dependent necroptosis and the M1 polarization of microglia/macrophages were blocked either by HPC or via overexpression of A20 in neurons, which ultimately mitigated cerebral injury in CA1 after tGCI. These data support that A20 serves as a crucial mediator of microglia/macrophages polarization by suppressing neuronal necroptosis in a RIP3 ubiquitination-dependent manner after tGCI. Also, a novel mechanism by which HPC functions in cerebral ischemic tolerance is elucidated.

Fine particulate matter (PM2.5) exposure has been associated with increased incidence and mortality of lung cancer. However, the molecular mechanisms underlying PM2.5 carcinogenicity remain incompletely understood. Here, we identified that PM2.5 suppressed the expression of tRNA methyltransferase FTSJ1 and Am modification level of tRNA in vitro and in vivo. FTSJ1 downregulation enhanced glycolytic metabolism of non-small cell lung cancer (NSCLC) cells, as indicated by increased levels of lactate, pyruvate, and extracellular acidification rate (ECAR). Whereas treatment with glycolytic inhibitor 2-DG reversed this effect. In contrast, upregulation of FTSJ1 significantly suppressed glycolysis of NSCLC cells. Mechanistically, the silencing of FTSJ1 increased NSCLC cell proliferation and glycolysis through enhancing the expression and translation of PGK1. In human NSCLC tumor samples, FTSJ1 expression was negatively correlated with PGK1 expression level and the SUVmax value of PET/CT scan. In summary, our work reveals a previously unrecognized function of PM2.5-downregulated FTSJ1 on PGK1-mediated glycolysis in NSCLC, suggesting that targeted upregulation of FTSJ1 may represent a potential therapeutic strategy for NSCLC.

Rheumatoid arthritis (RA) is a chronic autoimmune disorder marked by pain, inflammation, and discomfort in the synovial joints. It is critical to understand the pathological mechanisms of RA progression. MicroRNA-378 (miR-378) is highly expressed in the synovium of RA patients and positively correlated with disease severity, but its function and underlying mechanisms remain poorly understood. In this study, miR-378 transgenic (miR-378^high) mice were used to construct the collagen-induced arthritis (CIA) model for exploring the role of miR-378 in RA development. miR-378^high CIA mice showed accelerated RA development, as evidenced by exaggerated joint swelling and bone structural deformities. More severe endoplasmic reticulum (ER) stress and the consequent angiogenesis and osteoclastogenesis were also activated in the synovial tissue and calcaneus, respectively, in the miR-378^high group, suggesting that ER plays a significant role in miR-378-mediated RA pathogenesis. Upon in vitro RA induction, fibroblast-like synoviocytes (FLSs) isolated from miR-378^high mice showed a higher expression level of ER stress markers. The conditioned medium (CM) from RA-FLSs of miR-378^high mice stimulated more intensive angiogenesis and osteoclastogenesis. The ER stress-related protein Crebrf was identified as a downstream target of miR-378. Crebrf knockdown diminished the promoting effect of miR-378 on ER stress, as well as its downstream angiogenesis and osteoclastogenesis activities. Tail vein injection of anti-miR-378 lentivirus in an established RA mouse model was shown to ameliorate RA progression. In conclusion, miR-378 amplified RA development by promoting ER stress and downstream angiogenesis and osteoclastogenesis, thus indicating that miR-378 may be a potential therapeutic target for RA treatment.