WD repeat-containing protein 1 maintains β-Catenin activity to promote pancreatic cancer aggressiveness

WDR1 promotes prostate cancer progression through Wnt/β-catenin signaling

Prostate cancer (PCa) is the second most common cancer and the fifth leading cause of cancer-related death among men. A comprehensive understanding of PCa progression is crucial for the development of innovative therapeutic strategies for its treatment. While WDR1 (WD-repeat domain 1) serves as a significant cofactor of actin-depolymerizing factor/cofilin, its role in PCa progression remains unknown. In this study, we demonstrated that knockdown of WDR1 in various PCa cells substantially inhibited cell proliferation, migration, and invasion in vitro, as confirmed at both the cellular and molecular levels. Moreover, the overexpression of WDR1 promoted PCa cell proliferation and metastasis in vitro. Mechanistically, we showed that the application of lithium chloride, an activator of the Wnt/β-Catenin signaling pathway, restored the suppressive effects of WDR1 deficiency on cell proliferation and migration in PCa cells. Our findings suggest that the WDR1-β-Catenin axis functions as an activator of the malignant phenotype and represents a promising therapeutic target for PCa treatment.

Exosome-derived tRNA fragments tRF-GluCTC-0005 promotes pancreatic cancer liver metastasis by activating hepatic stellate cells

Early metastasis is the primary factor in the very poor prognosis of pancreatic ductal adenocarcinoma (PDAC), with liver metastasis being the most common form of distant metastasis in PDAC. To investigate the mechanism of PDAC liver metastasis, we found that PDAC cells can promote the formation of pre-metastatic niches (PMNs) through exosomes to facilitate liver metastasis in the early stage. In our study, hepatic stellate cells (HSCs) were treated with PDAC-derived exosomes (PDAC-exo), and the activation of HSCs was detected. A novel transfer RNA-derived fragment, the tRF-GluCTC-0005 was obtained by small RNA sequencing from serum exosomes of PDAC patients. Bioinformatics analysis and RNA pull-down assays revealed the interaction between WDR1 and tRF-GluCTC-0005. A KPC transgenic mouse model and an AAV-mediated sh-WDR1 mouse model were used to detect the mechanism of liver metastasis in vivo. Finally, the dual luciferase reporter assay, protein mutation truncation assay, Co-IP assay, and flow cytometry assay were used to explore the molecular mechanism in HSCs activation and PMNs formation. We found that the tRF-GluCTC-0005 in exosomes binds to the 3' untranslated region of the mRNA of the WDRl in HSCs and increases mRNA stability. The N-terminals of WDR1 bind to the YAP protein directly, inhibit YAP phosphorylation, and promote the expression of YAP transcription factors. The tRF-GluCTC-0005 in PDAC-exo significantly recruits myeloid-derived suppressor cells (MDSCs) in the liver, creating a PMNs immunosuppressive microenvironment and further advancing liver metastasis from PDAC. Our results suggest that the key of PDAC liver metastasis is the activation of HSCs through upregulation of WDR1 by tRF-GluCTC-0005 in exosomes, which mediates the infiltration of MDSCs to form PMNs.

Ubiquitin signaling in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignant tumor of the digestive system, characterized by rapid progression and being prone to metastasis. Few effective treatment options are available for PDAC, and its 5-year survival rate is less than 9%. Many cell biological and signaling events are involved in the development of PDAC, among which protein post-translational modifications (PTMs), such as ubiquitination, play crucial roles. Catalyzed mostly by a three-enzyme cascade, ubiquitination induces changes in protein activity mainly by altering their stability in PDAC. Due to their role in substrate recognition, E3 ubiquitin ligases (E3s) dictate the outcome of the modification. Ubiquitination can be reversed by deubiquitylases (DUBs), which, in return, modified proteins to their native form. Dysregulation of E3s or DUBs that disrupt protein homeostasis is involved in PDAC. Moreover, the ubiquitination system has been exploited to develop therapeutic strategies, such as proteolysis-targeting chimeras (PROTACs). In this review, we summarize recent progress in our understanding of the role of ubiquitination in the development of PDAC and offer perspectives in the design of new therapies against this highly challenging disease.

Suppression of rhomboid domain-containing 1 produces anticancer effects in pancreatic adenocarcinoma through affection of the AKT/GSK-3β/β-catenin pathway

The protumor role of rhomboid domain-containing 1 (RHBDD1) has been observed in multiple cancers. However, the relationship between RHBDD1 and pancreatic adenocarcinoma has not been addressed. This project focused on the potential relevance of RHBDD1 in pancreatic adenocarcinoma. Bioinformatic analysis by publicly available data revealed that RHBDD1 was abundantly expressed in pancreatic adenocarcinoma. We further verified that RHBDD1 was expressed highly in clinical specimens of pancreatic adenocarcinoma. The Kaplan-Meier curve demonstrated that high-RHBDD1 expression was associated with poor prognosis in pancreatic adenocarcinoma patients. The functional studies revealed that depletion of RHBDD1 produced in vitro anticancer effects in pancreatic adenocarcinoma cells, including retardation of proliferation, reduction of metastatic potential, and induction of cell-cycle arrest at the G0/G1 phase and apoptosis. Mechanistic studies indicated that loss of RHBDD1 affected the activation of β-catenin via regulation of AKT. Forced expression of β-catenin reversed the RHBDD1-loss-induced anticancer effects in pancreatic adenocarcinoma cells. Crucially, depletion of RHBDD1 retarded the growth of pancreatic adenocarcinoma xenografts in vivo, a phenomenon associated with the AKT/β-catenin pathway. Collectively, these findings delineated that restraint of RHBDD1 displayed remarkable anticancer effects in pancreatic adenocarcinoma by affecting the AKT/β-catenin pathway. Our work unveils a pivotal role of RHBDD1 in pancreatic adenocarcinoma and proposes it as a novel candidate target for anticancer therapy of pancreatic adenocarcinoma.

The Actin Regulators Involved in the Function and Related Diseases of Lymphocytes

Actin is an important cytoskeletal protein involved in signal transduction, cell structure and motility. Actin regulators include actin-monomer-binding proteins, Wiskott-Aldrich syndrome (WAS) family of proteins, nucleation proteins, actin filament polymerases and severing proteins. This group of proteins regulate the dynamic changes in actin assembly/disassembly, thus playing an important role in cell motility, intracellular transport, cell division and other basic cellular activities. Lymphocytes are important components of the human immune system, consisting of T-lymphocytes (T cells), B-lymphocytes (B cells) and natural killer cells (NK cells). Lymphocytes are indispensable for both innate and adaptive immunity and cannot function normally without various actin regulators. In this review, we first briefly introduce the structure and fundamental functions of a variety of well-known and newly discovered actin regulators, then we highlight the role of actin regulators in T cell, B cell and NK cell, and finally provide a landscape of various diseases associated with them. This review provides new directions in exploring actin regulators and promotes more precise and effective treatments for related diseases.

The molecular biology of pancreatic adenocarcinoma: translational challenges and clinical perspectives

Pancreatic cancer is an increasingly common cause of cancer mortality with a tight correspondence between disease mortality and incidence. Furthermore, it is usually diagnosed at an advanced stage with a very dismal prognosis. Due to the high heterogeneity, metabolic reprogramming, and dense stromal environment associated with pancreatic cancer, patients benefit little from current conventional therapy. Recent insight into the biology and genetics of pancreatic cancer has supported its molecular classification, thus expanding clinical therapeutic options. In this review, we summarize how the biological features of pancreatic cancer and its metabolic reprogramming as well as the tumor microenvironment regulate its development and progression. We further discuss potential biomarkers for pancreatic cancer diagnosis, prediction, and surveillance based on novel liquid biopsies. We also outline recent advances in defining pancreatic cancer subtypes and subtype-specific therapeutic responses and current preclinical therapeutic models. Finally, we discuss prospects and challenges in the clinical development of pancreatic cancer therapeutics.

TNK2-AS1 upregulated by YY1 boosts the course of osteosarcoma through targeting miR-4319/WDR1

Mounting research papers have suggested that long non-coding RNAs (lncRNAs) elicit important functions in the progression of osteosarcoma (OS). This study focused on the role of TNK2-AS1 in OS. TNK2-AS1 was powerfully expressed in OS tissues and cell lines. In addition, TNK2-AS1 downregulation inhibited proliferative, migratory, and invasive capacities while promoting apoptosis in OS cells. miR-4319 was removed by TNK2-AS1 and therefore TNK2-AS1 elevated WDR1 expression in OS cells. miR-4319 had an inhibitory influence on OS progression, while WDR1 was a contributor to OS progression. Rescue assays certified that TNK2-AS1 promoted malignant phenotypes in vitro and the growth in vivo of OS cells by upregulating WDR1. In depth, we found that YY1 accelerated the transcription of TNK2-AS1 in OS cells, and that its role in OS also depended on TNK2-AS1-regulated WDR1. In conclusion, TNK2-AS1 was positively modulated by YY1 and aggravated the development of OS by 'sponging' miR-4319 to elevate WDR1. The findings highlighted that TNK2-AS1 might be a promising target for the treatment of OS.