(S)-10-Hydroxycamptothecin Inhibits EMT-evoked Osteosarcoma Cell Growth and Metastasis by Activating the HIPPO Signaling Pathway

BACKGROUND

Osteosarcoma is the most common primary bone cancer in children and adolescents with high metastatic ability.

AIM

This study aimed to explore the inhibitory effects of (S)-10-hydroxycamptothecin (HCPT) on osteosarcoma cell growth and metastasis as well as the underlying mechanism.

METHOD

The osteosarcoma cells of 143B and U-2 OS (U-2), treated with HCPT (20, 100, or 300 nM), underwent detections, such as CCK-8, flow cytometry, Transwell, wound healing, and immunoblotting. EMT-related key proteins, like N-cadherin, Snail, and Vimentin, were found to be down-regulated, while E-cadherin was up-regulated dose-dependently in HCPT-exposed 143B and U-2 cells. Additionally, incubation of 143B and U-2 cells with HCPT for 3 hours dosedependently reduced the expression ratios of p-LATS1/LATS1, p-MST1/MST1, p-YAP/YAP, and p-TAZ/TAZ.

RESULT

Taken together, our study has demonstrated HCPT to inhibit osteosarcoma growth and metastasis potentially by activating the HIPPO signaling pathway and reversing EMT.

CONCLUSION

HCPT might be a candidate agent for the prevention and treatment of osteosarcoma.

Protective effect of low-intensity pulsed ultrasound on immune checkpoint inhibitor-related myocarditis via fine-tuning CD4+ T-cell differentiation

PURPOSE

Immune checkpoint inhibitors (ICIs) have transformed traditional cancer treatments. Specifically, ICI-related myocarditis is an immune-related adverse event (irAE) with high mortality. ICIs activate CD4+ T-lymphocyte reprogramming, causing an imbalance between Th17 and Treg cell differentiation, ultimately leading to myocardial inflammatory damage. Low-intensity pulsed ultrasound (LIPUS) can limit inflammatory responses, with positive therapeutic effects across various cardiovascular inflammatory diseases; however, its role in the pathogenesis of ICI-related myocarditis and CD4+ T-cell dysfunction remains unclear. Accordingly, this study investigated whether LIPUS can alleviate ICI-related myocarditis inflammatory damage and, if so, aimed to elucidate the beneficial effects of LIPUS and its underlying molecular mechanisms.

METHODS

An in vivo model of ICI-related myocarditis was obtained by intraperitonially injecting male A/J mice with an InVivoPlus anti-mouse PD-1 inhibitor. LIPUS treatment was performed via an ultrasound-guided application to the heart via the chest wall. The echocardiographic parameters were observed and cardiac function was assessed using an in vivo imaging system. The expression of core components of the HIPPO pathway was analyzed via western blotting.

RESULTS

LIPUS treatment reduced cardiac immune responses and inflammatory cardiac injury. Further, LIPUS treatment alleviated the inflammatory response in mice with ICI-related myocarditis. Mechanistically, in the HIPPO pathway, the activation of Mst1-TAZ axis improved autoimmune inflammation by altering the interaction between the transcription factors FOXP3 and RORγt and regulating the differentiation of Treg and Th17 cells.

CONCLUSION

LIPUS therapy was shown to reduce ICI-related myocarditis inflammatory damage and improve cardiac function, representing an exciting finding for irAEs treatment.

ROCK1 is a multifunctional factor maintaining the primordial follicle reserve and follicular development in mice

The follicle is the basic structural and functional unit of the ovary in female mammals. The excessive depletion of follicles will lead to diminished ovarian reserve or even premature ovarian failure, resulting in diminished ovarian oogenesis and endocrine function. Excessive follicular depletion is mainly due to loss of primordial follicles. Our analysis of published human ovarian single-cell sequencing results by others revealed a significant increase in rho-associated protein kinase 1 (ROCK1) expression during primordial follicle development. However, the role of ROCK1 in primordial follicle development and maintenance is not clear. This study revealed a gradual increase in ROCK1 expression during primordial follicle activation. Inhibition of ROCK1 resulted in reduced primordial follicle activation, decreased follicular reserve, and delayed development of growing follicles. This effect may be achieved through the HIPPO pathway. The present study indicates that ROCK1 is a key molecule for primordial follicular reserve and follicular development.NEW & NOTEWORTHY ROCK1, one of the Rho GTPases, plays an important role in primordial follicle reserve and follicular development. ROCK1 was primarily expressed in the cytoplasm of oocytes and granulosa cell in mice. Inhibition of ROCK1 significantly reduced the primordial follicle reserve and delayed growing follicle development. ROCK1 regulates primordial follicular reserve and follicle development through the HIPPO signaling pathway. These findings shed new lights on the physiology of sustaining female reproduction.

Cyclic Phytosphingosine-1-Phosphate Primed Mesenchymal Stem Cells Ameliorate LPS-Induced Acute Lung Injury in Mice

Background and Objectives

O-cyclic phytosphingosine-1-phosphate (cP1P) is a synthetic chemical and has a structure like sphingosine-1-phosphate (S1P). S1P is known to promote cell migration, invasion, proliferation, and anti-apoptosis through hippocampal signals. However, S1P mediated cellular-, molecular mechanism is still remained in the lung. Acute lung injury (ALI) and its severe form acute respiratory distress syndrome (ARDS) are characterized by excessive immune response, increased vascular permeability, alveolar-peritoneal barrier collapse, and edema. In this study, we determined whether cP1P primed human dermal derived mesenchymal stem cells (hdMSCs) ameliorate lung injury and its therapeutic pathway in ALI mice.

Methods and Results

cP1P treatment significantly stimulated MSC migration and invasion ability. In cytokine array, secretion of vascular-related factors was increased in cP1P primed hdMSCs (hdMSC^cP1P), and cP1P treatment induced inhibition of Lats while increased phosphorylation of Yap. We next determined whether hdMSC^cP1P reduce inflammatory response in LPS exposed mice. hdMSC^cP1P further decreased infiltration of macrophage and neutrophil, and release of TNF-α, IL-1β, and IL-6 were reduced rather than naïve hdMSC treatment. In addition, phosphorylation of STAT1 and expression of iNOS were significantly decreased in the lungs of MSC^cP1P treated mice.

Conclusions

Taken together, these data suggest that cP1P treatment enhances hdMSC migration in regulation of Hippo signaling and MSC^cP1P provide a therapeutic potential for ALI/ARDS treatment.

Plpp3, a novel regulator of pluripotency exit and endodermal differentiation of mouse embryonic stem cells

In recent decades, study of the actions of bioactive lipids such as lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) has increased since they are involved in regulating many processes, including self-renewal of embryonic stem cells, embryo development and cancer. Phospholipid phosphatase type 3 (PLPP3) has been shown to be a key player in regulating the balance of these lipids and, in consequence, their signaling. Different lines of evidence suggest that PLPP3 could play a role in endoderm development. To approach this hypothesis, we used mouse embryonic stem cells (ESC) as a model to study Plpp3 function in self-renewal and the transition towards differentiation. We found that lack of PLPP3 mainly affects endoderm formation during differentiation of suspension-formed embryoid bodies. PLPP3-deficient ESC strongly decrease the amount of FOXA2-expressing cells and fail to properly downregulate the expression of pluripotency factors when subjected to an endoderm-directed differentiation protocol. Impaired endoderm differentiation correlated with a transient reduction in nuclear localization of YAP1. These phenotypes were rescued by transiently restoring the expression of catalytically active hPLPP3. In conclusion, PLPP3 plays a role in downregulating pluripotency-associated factors and in endodermal differentiation. PLPP3 regulates proper lipid/YAP1 signaling required for endodermal differentiation.

The Roles of miRNAs in Predicting Bladder Cancer Recurrence and Resistance to Treatment

Bladder cancer (BCa) is associated with significant morbidity, with development linked to environmental, lifestyle, and genetic causes. Recurrence presents a significant issue and is managed in the clinical setting with intravesical chemotherapy or immunotherapy. In order to address challenges such as a limited supply of BCG and identifying cases likely to recur, it would be advantageous to use molecular biomarkers to determine likelihood of recurrence and treatment response. Here, we review microRNAs (miRNAs) that have shown promise as predictors of BCa recurrence. MiRNAs are also discussed in the context of predicting resistance or susceptibility to BCa treatment.

Partial EMT in Squamous Cell Carcinoma: A Snapshot

In the process of cancer EMT, some subgroups of cancer cells simultaneously exhibit both mesenchymal and epithelial characteristics, a phenomenon termed partial EMT (pEMT). pEMT is a plastic state in which cells coexpress epithelial and mesenchymal markers. In squamous cell carcinoma (SCC), pEMT is regulated, and the phenotype is maintained via the HIPPO pathway, NOTCH pathway and TGF-β pathways and by microRNAs, lncRNAs and the cancer microenvironment (CME); thus, SCC exhibits aggressive tumorigenic properties and high stemness, which leads collective migration and therapy resistance. Few studies have reported therapeutic interventions to address cells that have undergone pEMT, and this approach may be an effective way to inhibit the plasticity, drug resistance and metastatic potential of SCC.

Hippo Signaling in Embryogenesis and Development

Hippo pathway components are structurally and functionally conserved and are notable for their role in controlling organ size. More diverse functions of the Hippo pathway have been recognized, including development, tissue homeostasis, wound healing and regeneration, immunity, and tumorigenesis. During embryogenesis, different signaling pathways are repeatedly and cooperatively activated, leading to differential gene expression in specific developmental contexts. In this article, we present an overview on the regulation and function of the Hippo pathway in mammalian early development. We introduce the Hippo pathway components and major upstream signals that act through this pathway to influence embryogenesis. We also discuss the roles of Hippo pathway in tissue specification and organ development during organogenesis.

Loss of Two-Pore Channel 2 (TPC2) Expression Increases the Metastatic Traits of Melanoma Cells by a Mechanism Involving the Hippo Signalling Pathway and Store-Operated Calcium Entry

Melanoma is one of the most aggressive and treatment-resistant human cancers. The two-pore channel 2 (TPC2) is located on late endosomes, lysosomes and melanosomes. Here, we characterized how TPC2 knockout (KO) affected human melanoma cells derived from a metastatic site. TPC2 KO increased these cells’ ability to invade the extracelullar matrix and was associated with the increased expression of mesenchymal markers ZEB-1, Vimentin and N-Cadherin, and the enhanced secretion of MMP9. TPC2 KO also activated genes regulated by YAP/TAZ, which are key regulators of tumourigenesis and metastasis. Expression levels of ORAI1, a component of store-operated Ca²⁺ entry (SOCE), and PKC-βII, part of the HIPPO pathway that negatively regulates YAP/TAZ activity, were reduced by TPC2 KO and RNA interference knockdown. We propose a cellular mechanism mediated by ORAI1/Ca²⁺/PKC-βII to explain these findings. Highlighting their potential clinical significance, patients with metastatic tumours showed a reduction in TPC2 expression. Our research indicates a novel role of TPC2 in melanoma. While TPC2 loss may not activate YAP/TAZ target genes in primary melanoma, in metastatic melanoma it could activate such genes and increase cancer aggressiveness. These findings aid the understanding of tumourigenesis mechanisms and could provide new diagnostic and treatment strategies for skin cancer and other metastatic cancers.

Targeting G protein-coupled receptors in cancer therapy

As basic research into GPCR signaling and its association with disease has come into fruition, greater clarity has emerged with regards to how these receptors may be amenable to therapeutic intervention. As a diverse group of receptor proteins, which regulate a variety of intracellular signaling pathways, research in this area has been slow to yield tangible therapeutic agents for the treatment of a number of diseases including cancer. However, recently such research has gained momentum based on a series of studies that have sought to define GPCR proteins dynamics through the elucidation of their crystal structures. In this chapter, we define the approaches that have been adopted in developing better therapeutics directed against the specific parts of the receptor proteins, such as the extracellular and the intracellular domains, including the ligands and auxiliary proteins that bind them. Finally, we also briefly outline how GPCR-derived signaling transduction pathways hold great potential as additional targets.

Global-scale seasonally resolved black carbon vertical profiles over the Pacific

[1] Black carbon (BC) aerosol loadings were measured during the High-performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations (HIPPO) campaign above the remote Pacific from 85°N to 67°S. Over 700 vertical profiles extending from near the surface to max ∼14 km altitude were obtained with a single-particle soot photometer between early 2009 and mid-2011. The data provides a climatology of BC in the remote regions that reveals gradients of BC concentration reflecting global-scale transport and removal of pollution. BC is identified as a sensitive tracer of extratropical mixing into the lower tropical tropopause layer and trends toward surprisingly uniform loadings in the lower stratosphere of ∼1 ng/kg. The climatology is compared to predictions from the AeroCom global model intercomparison initiative. The AeroCom model suite overestimates loads in the upper troposphere/lower stratosphere (∼10×) more severely than at lower altitudes (∼3×), with bias roughly independent of season or geographic location; these results indicate that it overestimates BC lifetime.