High frequency of KRAS and TP53 mutations is a unique genetic feature of pancreatic ductal adenocarcinoma (PDAC). TP53 mutation not only renders PDAC resistance to chemotherapies but also drives PDAC invasiveness. Therapies targeting activating mutant KRAS are not available and the outcomes of current PDAC treatment are extremely poor. Here, we report that MMRi62, initially identified as an MDM2-MDM4–targeting small molecule with p53-independent pro-apoptotic activity, shows anti-PDAC activity in vitro and in vivo. We show that MMRi62 inhibits proliferation, clonogenic, and spheroid growth of PDAC cells by induction of cell death. MMRi62-induced cell death in PDAC is characteristic of ferroptosis that is associated with increased autophagy, increased reactive oxygen species, and lysosomal degradation of NCOA4 and ferritin heavy chain (FTH1). In addition to induced degradation of FTH1, MMRi62 also induces proteasomal degradation of mutant p53. Interestingly, MMRi62-induced ferroptosis occurs in PDAC cell lines harboring either KRAS and TP53 double mutations or single TP53 mutation. In orthotopic xenograft PDAC mouse models, MMRi62 was capable of inhibiting tumor growth in mice associated with downregulation of NCOA4 and mutant p53 in vivo. Strikingly, MMRi62 completely abrogated metastasis of orthotopic tumors to distant organs, which is consistent with MMRi62's ability to inhibit cell migration and invasion in vitro. These findings identified MMRi62 as a novel ferroptosis inducer capable of suppressing PDAC growth and overcoming metastasis.

TBC1 domain containing kinase (TBCK) protein is composed of three conserved domains, including N‑terminal Serine/Threonine kinase domain, central TBC domain and C‑terminal rhodanese homology domain (RHOD). A total of 9 different transcripts (classified as long and short TBCK) generated by alternative splicing have been reported in different cell lines. Exogenous expression of long TBCK has been identified to function as a suppressor of cell growth in certain cell types. On the contrary, TBCK has also been reported to serve a tumor‑promoting role in other cell lines, indicating that TBCK might function differentially, depending on the context in different cellular environments. Furthermore, deleterious homozygous or compound heterozygous mutations identified by whole‑exome sequencing in the TBCK gene could ablate the function of TBCK, further impacting the mTOR signaling pathway and leading to neurogenetic disorders, such as hypotonia, global developmental delay, facial dysmorphic features and brain abnormalities. However, as a poorly explored protein, there are a lot of studies associated with the functions of TBCK that need to be performed in the future. The present review summarizes data regarding the structural features and potential roles of TBCK in developmental and neurological diseases and tumorigenesis. Future prospects of TBCK research lie in revealing numerous biological functions of TBCK.

Recently, the human ether à go-go (eag) related gene 1 (hERG1) channel, a member of the voltage-dependent potassium channel (Kv) family, was determined to have a critical role in cancer cell proliferation, invasion, tumorigenesis and apoptosis. However, the expression levels and functions of hERG1 in osteosarcoma cells remain poorly characterized. In this study, hERG1 transcript and protein levels in osteosarcoma cells and tissues were measured using semi-quantitative real time PCR (RT-PCR), Western blot, and immunohistochemistry. The effects of hERG1 knockdown on osteosarcoma cell proliferation, apoptosis and invasion were examined using CCK-8, colony formation, flow cytometry, caspase-3 activity, wound healing and transwell based assays. Furthermore, semi-quantitative RT-PCR, Western blot and a luciferase reporter assay were used to assess the effects of hERG1 inhibition on the nuclear factor-κB (NF-κB) pathway. In addition, the effect of NF-κB p65-siRNA and NF-κB p65 expression on the survival of osteosarcoma cells was investigated. Through this work, a relationship for hERG1 with the NF-κB pathway was identified. Osteosarcoma cells and tissues were found to express high levels of hERG1. Knockdown of hERG1 significantly suppressed cellular proliferation and invasion, and induced apoptosis, while inhibition of hERG1 significantly decreased activation of NF-κB. Overall, hERG1 may stimulate nuclear translocation of p65, thus regulating the NF-κB pathway through the activation of the hERG1/beta1 integrin complex and PI3K/AKT signaling. Taken together, these results demonstrate that hERG1 is necessary for regulation of osteosarcoma cellular proliferation, apoptosis and migration. Furthermore, this regulation by hERG1 is, at least in part, through mediation of the NF-κB pathway.

So far, the role of Ether à go-go 1 (Eag1) potassium channels in migration and invasion progression of cancers remains elusive. In the present study, the effects ofEag1knockdown on osteosarcoma cell proliferation, growth, and apoptosis were examined. Then, we evaluated the effects ofEag1silencing on osteosarcoma cell migration and invasion. In addition, we detected the expression of vascular endothelial growth factor (VEGF) and signal transducer and activator of transcription 3 (STAT3) in osteosarcoma cell treated with Eag1 small interfering RNAs (siRNAs). Finally, STAT3 siRNA was employed to determine the influence of downregulation of STAT3 on cell proliferation and migration. The results showed that knockdown ofEag1significantly suppressed osteosarcoma cell proliferation and osteosarcoma xenografts growth. However,Eag1silencing had little effect on cell apoptosis. Additionally, osteosarcoma cell adhesion, migration, and invasion were also potently attenuated. Notably, the expression levels of VEGF decreased evidently upon Eag1 siRNAs treatment, paralleled with reductions in the expression levels of STAT3. Moreover, a similar pattern was observed in osteosarcoma cell proliferation and migration suppression between STAT3 siRNA and Eag1 siRNAs groups. Our data indicated that Eag1 promotes osteosarcoma proliferation and migration, at least in part, by targeting STAT3-VEGF pathway.

The cytosolic PNGase (peptide:N-glycanase), also known as peptide-N4-(N-acetyl-β-glucosaminyl)-asparagine amidase, is a well-conserved deglycosylation enzyme (EC 3.5.1.52) which catalyzes the non-lysosomal hydrolysis of an N(4)-(acetyl-β-d-glucosaminyl) asparagine residue (Asn, N) into a N-acetyl-β-d-glucosaminyl-amine and a peptide containing an aspartate residue (Asp, D). This enzyme (NGLY1) plays an essential role in the clearance of misfolded or unassembled glycoproteins through a process named ER-associated degradation (ERAD). Accumulating evidence also points out that NGLY1 deficiency can cause an autosomal recessive (AR) human genetic disorder associated with abnormal development and congenital disorder of deglycosylation. In addition, the loss of NGLY1 can affect multiple cellular pathways, including but not limited to NFE2L1 pathway, Creb1/Atf1-AQP pathway, BMP pathway, AMPK pathway, and SLC12A2 ion transporter, which might be the underlying reasons for a constellation of clinical phenotypes of NGLY1 deficiency. The current comprehensive review uncovers the NGLY1’ssdetailed structure and its important roles for participation in ERAD, involvement in CDDG and potential treatment for NGLY1 deficiency.

The combination of CDK4/6 and MEK inhibition as a therapeutic strategy has shown promise in various cancer models, particularly in those harboring RAS mutations. An initial high-throughput drug screen identified high synergy between the CDK4/6 inhibitor palbociclib and the MEK inhibitor trametinib when used in combination in soft tissue sarcomas. In RAS mutant models, combination treatment with palbociclib and trametinib induced significant G1 cell cycle arrest, resulting in a marked reduction in cell proliferation and growth. CRISPR-mediated RB1 depletion resulted in a decreased response to CDK4/6 and MEK inhibition, which was validated in both cell culture and xenograft models. Beyond its cell cycle inhibitory effects, pathway enrichment analysis revealed the robust activation of interferon pathways upon CDK4/6 and MEK inhibition. This induction of gene expression was associated with the upregulation of retroviral elements. The TANK-binding kinase 1 inhibitor GSK8612 selectively blocked the induction of interferon-related genes induced by palbociclib and trametinib treatment and highlighted the separable epigenetic responses elicited by combined CDK4/6 and MEK inhibition. Together, these findings provide key mechanistic insights into the therapeutic potential of CDK4/6 and MEK inhibition in soft tissue sarcomas.