Effects of a checkpoint kinase inhibitor, AZD7762, on tumor suppression and bone remodeling

NEDD4L affects stability of the CHEK2/TP53 axis through ubiquitination modification to enhance osteogenic differentiation of periodontal ligament stem cells

BACKGROUND

Checkpoint kinase 2 (CHEK2) and its regulated tumor protein p53 (TP53) have been correlated with osteogenic differentiation of osteoblast-like cells. Based on bioinformatics predictions, this study aims to investigate the effect of the CHEK2/TP53 axis on osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and to explore the regulatory mechanism.

METHODS

PDLSCs were isolated from human impacted wisdom teeth, and they were cultured in normal medium (NM) or osteogenic medium (OM). Protein levels of CHEK2 and TP53 were examined using western blot analysis. Osteogenic differentiation ability of PDLSCs was analyzed by measuring marker proteins (RUNX2, OCN, and OSX), ALP activity, and ALP staining. Molecular interaction between NEDD4 like E3 ubiquitin protein ligase (NEDD4L) and CHEK2 was examined by ubiquitination and co-immunoprecipitation assays. Gain- and loss-of function assays of NEDD4L, CHEK2, and TP53 were performed to analyze their function in osteogenic differentiation of PDLSCs. A rat model of mandibular bone defect was generated for in vivo validation.

RESULTS

NEDD4L was upregulated, while CHEK2 and TP53 were downregulated in PDLSCs cultured in OM. CHEK2 protected TP53 from degradation, while NEDD4L reduced CHEK2 protein level by ubiquitination modification. NEDD4L silencing reduced osteogenic differentiation ability of PDLSCs both in vitro and in vivo, which was restored by CHEK2 silencing. By contrast, CHEK2 overexpression blocked the osteogenic differentiation of PDLSCs in vitro.

CONCLUSION

This study demonstrates that NEDD4L affects protein stability of the CHEK2/TP53 axis through ubiquitination modification, thus increasing osteogenic differentiation of PDLSCs.

Developing targeted therapies for neuroblastoma by dissecting the effects of metabolic reprogramming on tumor microenvironments and progression

Rationale: Synergic reprogramming of metabolic dominates neuroblastoma (NB) progression. It is of great clinical implications to develop an individualized risk prognostication approach with stratification-guided therapeutic options for NB based on elucidating molecular mechanisms of metabolic reprogramming. Methods: With a machine learning-based multi-step program, the synergic mechanisms of metabolic reprogramming-driven malignant progression of NB were elucidated at single-cell and metabolite flux dimensions. Subsequently, a promising metabolic reprogramming-associated prognostic signature (MPS) and individualized therapeutic approaches based on MPS-stratification were developed and further validated independently using pre-clinical models. Results: MPS-identified MPS-I NB showed significantly higher activity of metabolic reprogramming than MPS-II counterparts. MPS demonstrated improved accuracy compared to current clinical characteristics [AUC: 0.915 vs. 0.657 (MYCN), 0.713 (INSS-stage), and 0.808 (INRG-stratification)] in predicting prognosis. AZD7762 and etoposide were identified as potent therapeutics against MPS-I and II NB, respectively. Subsequent biological tests revealed AZD7762 substantially inhibited growth, migration, and invasion of MPS-I NB cells, more effectively than that of MPS-II cells. Conversely, etoposide had better therapeutic effects on MPS-II NB cells. More encouragingly, AZD7762 and etoposide significantly inhibited in-vivo subcutaneous tumorigenesis, proliferation, and pulmonary metastasis in MPS-I and MPS-II samples, respectively; thereby prolonging survival of tumor-bearing mice. Mechanistically, AZD7762 and etoposide-induced apoptosis of the MPS-I and MPS-II cells, respectively, through mitochondria-dependent pathways; and MPS-I NB resisted etoposide-induced apoptosis by addiction of glutamate metabolism and acetyl coenzyme A. MPS-I NB progression was fueled by multiple metabolic reprogramming-driven factors including multidrug resistance, immunosuppressive and tumor-promoting inflammatory microenvironments. Immunologically, MPS-I NB suppressed immune cells via MIF and THBS signaling pathways. Metabolically, the malignant proliferation of MPS-I NB cells was remarkably supported by reprogrammed glutamate metabolism, tricarboxylic acid cycle, urea cycle, etc. Furthermore, MPS-I NB cells manifested a distinct tumor-promoting developmental lineage and self-communication patterns, as evidenced by enhanced oncogenic signaling pathways activated with development and self-communications. Conclusions: This study provides deep insights into the molecular mechanisms underlying metabolic reprogramming-mediated malignant progression of NB. It also sheds light on developing targeted medications guided by the novel precise risk prognostication approaches, which could contribute to a significantly improved therapeutic strategy for NB.

Application of three-dimensional (3D) bioprinting in anti-cancer therapy

Three-dimensional (3D) bioprinting is a novel technology that enables the creation of 3D structures with bioinks, the biomaterials containing living cells. 3D bioprinted structures can mimic human tissue at different levels of complexity from cells to organs. Currently, 3D bioprinting is a promising method in regenerative medicine and tissue engineering applications, as well as in anti-cancer therapy research. Cancer, a type of complex and multifaceted disease, presents significant challenges regarding diagnosis, treatment, and drug development. 3D bioprinted models of cancer have been used to investigate the molecular mechanisms of oncogenesis, the development of cancers, and the responses to treatment. Conventional 2D cancer models have limitations in predicting human clinical outcomes and drug responses, while 3D bioprinting offers an innovative technique for creating 3D tissue structures that closely mimic the natural characteristics of cancers in terms of morphology, composition, structure, and function. By precise manipulation of the spatial arrangement of different cell types, extracellular matrix components, and vascular networks, 3D bioprinting facilitates the development of cancer models that are more accurate and representative, emulating intricate interactions between cancer cells and their surrounding microenvironment. Moreover, the technology of 3D bioprinting enables the creation of personalized cancer models using patient-derived cells and biomarkers, thereby advancing the fields of precision medicine and immunotherapy. The integration of 3D cell models with 3D bioprinting technology holds the potential to revolutionize cancer research, offering extensive flexibility, precision, and adaptability in crafting customized 3D structures with desired attributes and functionalities. In conclusion, 3D bioprinting exhibits significant potential in cancer research, providing opportunities for identifying therapeutic targets, reducing reliance on animal experiments, and potentially lowering the overall cost of cancer treatment. Further investigation and development are necessary to address challenges such as cell viability, printing resolution, material characteristics, and cost-effectiveness. With ongoing progress, 3D bioprinting can significantly impact the field of cancer research and improve patient outcomes.

Chk1/2 inhibitor AZD7762 enhances the susceptibility of IDH-mutant brain cancer cells to temozolomide

The IDH mutation initially exhibits chemosensitive properties, progression-free survival cannot be achieved in the later grades, and malignant transformation occurs as a result of TMZ-induced hypermutation profile and adaptation to this profile. In this study, we evaluated the potential of the combination of TMZ and AZD7762 at molecular level, to increase the anticancer activity of TMZ in IDH-mutant U87-mg cells. We used the WST-1 test to evaluate cytotoxic effect of TMZ and AZD7762 combination with dose-effect and isobologram curves. The effects of the inhibitory and effective concentrations of the combination on apoptosis, cell cycle and γ-H2AX phosphorylation were analyzed with flow cytometry. The expression of genes responsible for the DNA damage response was analyzed with qRT-PCR. The combination showed a synergistic effect with high dose reduction index. Single and combined administrations of TMZ and AZD7762 increased in G₂/M arrest from 24 to 48 h, and cells in the G₂/M phase shifted towards octaploidy at 72 h. While no double-strand breaks were detected after TMZ treatment, AZD7762 and combination treatments caused a significant increase in γ-H2AX phosphorylation and increased apoptotic stimulation towards 72 h although TMZ did not cause apoptotic effect in IDH-mutant U87-mg cells. The genes controlling the apoptosis were determined to be upregulated in all three groups, and genes regarding cell cycle checkpoints were downregulated. Targeting Chk1/2 with AZD7762 simultaneously with TMZ may be a potential therapeutic strategy for both increasing the sensitivity of IDH-mutant glioma cells to TMZ and reducing the dose of TMZ. In IDH-mutant glioma cells, AZD7762, the Chk1/2 inhibitor, can increase the efficacy of Temozolomide by (i) increasing mitotic chaos, and (ii) inhibiting double-strand break repair, (iii) thereby inducing cell death.

Suppression of breast cancer-associated bone loss with osteoblast proteomes via Hsp90ab1/moesin-mediated inhibition of TGFβ/FN1/CD44 signaling

Background: Bone is a frequent site of metastases from breast cancer, but existing therapeutic options are not satisfactory. Although osteoblasts have active roles in cancer progression by assisting the vicious bone-destructive cycle, we employed a counterintuitive approach of activating pro-tumorigenic Wnt signaling and examined the paradoxical possibility of developing osteoblast-derived tumor-suppressive, bone-protective secretomes. Methods: Wnt signaling was activated by the overexpression of Lrp5 and β-catenin in osteoblasts as well as a pharmacological agent (BML284), and the therapeutic effects of their conditioned medium (CM) were evaluated using in vitro cell cultures, ex vivo breast cancer tissues, and a mouse model of osteolysis. To explore the unconventional regulatory mechanism of the action of Wnt-activated osteoblasts, whole-genome proteomics analysis was conducted, followed by immunoprecipitation and gain- and loss-of-function assays. Results: While osteoblasts did not present any innate tumor-suppressing ability, we observed that the overexpression of Lrp5 and β-catenin in Wnt signaling made their CM tumor-suppressive and bone-protective. The growth of breast cancer cells and tissues was inhibited by Lrp5-overexpressing CM (Lrp5 CM), which suppressed mammary tumors and tumor-driven bone destruction in a mouse model. Lrp5 CM also inhibited the differentiation and maturation of bone-resorbing osteoclasts by downregulating NFATc1 and cathepsin K. The overexpression of Lrp5 upregulated osteopontin that enriched Hsp90ab1 (Hsp90 beta) and moesin (MSN) in Lrp5 CM. Hsp90ab1 and MSN are atypical tumor-suppressing proteins since they are multi-tasking, moonlighting proteins that promote tumorigenesis in tumor cells. Importantly, Hsp90ab1 immuno-precipitated latent TGFβ and inactivated TGFβ, whereas MSN interacted with CD44, a cancer stem-cell marker, as well as fibronectin 1, an ECM protein. Furthermore, Hsp90ab1 and MSN downregulated KDM3A that demethylated histones, together with PDL1 that inhibited immune responses. Conclusion: In contrast to inducing tumor-enhancing secretomes and chemoresistance in general by inhibiting varying oncogenic pathways in chemotherapy, this study presented the unexpected outcome of generation tumor-suppressive secretomes by activating the pro-tumorigenic Wnt pathway. The results shed light on the contrasting role of oncogenic signaling in tumor cells and osteoblast-derived secretomes, suggesting a counterintuitive option for the treatment of breast cancer-associated bone metastasis.

Mechanical Loading-Driven Tumor Suppression Is Mediated by Lrp5-Dependent and Independent Mechanisms

Simple Summary

Advanced breast cancer and prostate cancer metastasize to varying organs including the bone. We show here that mechanical loading to the knee suppresses tumor growth in the loaded bone and the non-loaded mammary pad. Although lipoprotein receptor-related protein 5 (Lrp5) in osteocytes is necessary to induce loading-driven bone formation, loading-driven tumor suppression is regulated by Lrp5-dependent and independent mechanisms. Lrp5 overexpression in osteocytes enhances tumor suppression, but without Lrp5 in osteocytes, mechanical loading elevates dopamine, chemerin, p53, and TNF-related apoptosis-inducing ligand (TRAIL) and reduces cholesterol and nexin. Their systemic changes contribute to inhibiting tumors without Lrp5. Osteoclast development is also inhibited by the load-driven regulation of chemerin and nexin.

Abstract

Bone is mechanosensitive and lipoprotein receptor-related protein 5 (Lrp5)-mediated Wnt signaling promotes loading-driven bone formation. While mechanical loading can suppress tumor growth, the question is whether Lrp5 mediates loading-driven tumor suppression. Herein, we examined the effect of Lrp5 using osteocyte-specific Lrp5 conditional knockout mice. All mice presented noticeable loading-driven tumor suppression in the loaded tibia and non-loaded mammary pad. The degree of suppression was more significant in wild-type than knockout mice. In all male and female mice, knee loading reduced cholesterol and elevated dopamine. It reduced tumor-promoting nexin, which was elevated by cholesterol and reduced by dopamine. By contrast, it elevated p53, TNF-related apoptosis-inducing ligand (TRAIL), and chemerin, and they were regulated reversely by dopamine and cholesterol. Notably, Lrp5 overexpression in osteocytes enhanced tumor suppression, and osteoclast development was inhibited by chemerin. Collectively, this study identified Lrp5-dependent and independent mechanisms for tumor suppression. Lrp5 in osteocytes contributed to the loaded bone, while the Lrp5-independent regulation of dopamine- and cholesterol-induced systemic suppression.

Network-based survival analysis to discover target genes for developing cancer immunotherapies and predicting patient survival

Recently, cancer immunotherapies have been life-savers, however, only a fraction of treated patients have durable responses. Consequently, statistical methods that enable the discovery of target genes for developing new treatments and predicting patient survival are of importance. This paper introduced a network-based survival analysis method and applied it to identify candidate genes as possible targets for developing new treatments. RNA-seq data from a mouse study was used to select differentially expressed genes, which were then translated to those in humans. We constructed a gene network and identified gene clusters using a training set of 310 human gliomas. Then we conducted gene set enrichment analysis to select the gene clusters with significant biological function. A penalized Cox model was built to identify a small set of candidate genes to predict survival. An independent set of 690 human glioma samples was used to evaluate predictive accuracy of the survival model. The areas under time-dependent ROC curves in both the training and validation sets are more than 90%, indicating strong association between selected genes and patient survival. Consequently, potential biomedical interventions targeting these genes might be able to alter their expressions and prolong patient survival.

Preventing tumor progression to the bone by induced tumor-suppressing MSCs

Background: Advanced breast cancer metastasizes to many organs including bone, but few effective treatments are available. Here we report that induced tumor-suppressing (iTS) MSCs protected bone from metastases while un-induced MSCs did not. Methods: iTS MSCs were generated by overexpressing Lrp5, β-catenin, Snail, or Akt. Their tumor-suppressing capability was tested using a mouse model of mammary tumors and bone metastasis, human breast cancer tissues and cancer cell lines. Results: In a mouse model, the induced MSC-derived conditioned medium (MSC CM) reduced mammary tumors and suppressed tumor-induced osteolysis. Tumor-promoting genes such as CXCL2 and LIF, as well as PDL1, a blocker of T-cell-based immune responses were downregulated. Proteomics analysis revealed that heat shock protein 90 (Hsp90ab1), calreticulin (Calr) and peptidylprolyl isomerase B (Ppib), which are highly expressed intracellular proteins in many cancers, were enriched in MSC CM as atypical tumor suppressors. Thus, overexpressing selected genes that were otherwise tumorigenic rendered MSCs the tumor-suppressing capability through the atypical suppressors, as well as p53 and Trail. Notably, the inhibitory effect of Lrp5- and Akt-overexpressing MSC CMs, Hsp90ab1 and Calr presented selective inhibition to tumor cells than non-tumor cells. The development of bone-resorbing osteoclasts was also suppressed by MSC CMs. Conclusion: Collectively, the results showed an anti-tumor effect of iTS MSCs and suggested novel therapeutic approaches to suppress the progression of tumors into the bone.

A Tiered Female Ovarian Toxicity Screening Identifies Toxic Effects of Checkpoint Kinase 1 Inhibitors on Murine Growing Follicles

Ovarian toxicity (ovotoxicity) is one of the major side effects of pharmaceutical compounds for women at or before reproductive age. The current gold standard for screening of compounds' ovotoxicity largely relies on preclinical investigations using whole animals. However, in vivo models are time-consuming, costly, and harmful to animals. Here, we developed a 3-tiered ovotoxicity screening approach starting from encapsulated in vitro follicle growth (eIVFG) and screened for the potential ovotoxicity of 8 preclinical compounds from AstraZeneca (AZ). Results from Tiers 1 to 2 screenings using eIVFG showed that the first 7 tested AZ compounds, AZ-A, -B, -C, -D, -E, -F, and -G, had no effect on examined mouse follicle and oocyte reproductive outcomes, including follicle survival and development, 17β-estradiol secretion, ovulation, and oocyte meiotic maturation. However, AZ-H, a preclinical compound targeting the checkpoint kinase 1 inhibitor to potentiate the anticancer effects of DNA-damaging agents, significantly promoted granulosa cell apoptosis and the entire growing follicle atresia at clinically relevant concentrations of 1 and 10 μM. The more targeted explorations in Tier 2 revealed that the ovotoxic effect of AZ-H primarily resulted from checkpoint kinase 1 inhibition in granulosa cells. Using in vivo mouse model, the Tier 3 screening confirmed the in vitro ovotoxicities of AZ-H discovered in Tiers 1 and 2. Also, although AZ-H at 0.1 μM alone was not ovotoxic, it significantly exacerbated gemcitabine-induced ovotoxicities on growing follicles. Taken together, our study demonstrates that the tiered ovotoxicity screening approach starting from eIVFG identifies and prioritizes pharmaceutical compounds of high ovotoxicity concern.

Pitavastatin slows tumor progression and alters urine-derived volatile organic compounds through the mevalonate pathway

Bone is a frequent site of metastasis from breast cancer, and a desirable drug could suppress tumor growth as well as metastasis-linked bone loss. Currently, no drug is able to cure breast cancer-associated bone metastasis. In this study, we focused on statins that are known to inhibit cholesterol production and act as antitumor agents. After an initial potency screening of 7 U.S. Food and Drug Administration-approved statins, we examined pitavastatin as a drug candidate for inhibiting tumor and tumor-induced bone loss. In vitro analysis revealed that pitavastatin acted as an inhibitor of tumor progression by altering stress to the endoplasmic reticulum, down-regulating peroxisome proliferator-activated receptor γ, and reducing Snail and matrix metalloproteinase 9. In bone homeostasis, it blocked osteoclast development by suppressing transcription factors c-Fos and JunB, but stimulated osteoblast mineralization by regulating bone morphogenetic protein 2 and p53. In a mouse model, pitavastatin presented a dual role in tumor inhibition in the mammary fat pad, as well as in bone protection in the osteolytic tibia. In mass spectrometry-based analysis, volatile organic compounds (VOCs) that were linked to lipid metabolism and cholesterol synthesis were elevated in mice from the tumor-grown placebo group. Notably, pitavastatin-treated mice reduced specific VOCs that are linked to lipid metabolites in the mevalonate pathway. Collectively, the results lay a foundation for further investigation of pitavastatin's therapeutic efficacy in tumor-induced bone loss, as well as VOC-based diagnosis of tumor progression and treatment efficacy.-Wang, L., Wang, Y., Chen, A., Teli, M., Kondo, R., Jalali, A., Fan, Y., Liu, S., Zhao, X., Siegel, A., Minami, K., Agarwal, M., Li, B.-Y., Yokota, H. Pitavastatin slows tumor progression and alters urine-derived volatile organic compounds through the mevalonate pathway.

The clinical significance of CHEK1 in breast cancer: a high-throughput data analysis and immunohistochemical study

Breast cancer (BC) is a kind of malignant cancer that seriously threatens women's health. Research scientists have found that BC occurs as the result of multiple effects of the external environment and internal genetic changes. Cell cycle checkpoint kinase 1 (CHEK1) is a crucial speed limit point in the cell cycle. Alterations of CHEK1 have been found in various tumors but are rarely reported or verified in BC. By mining database information, a large amount of mRNA and protein data was collected and meta-analyzed. Also, in-house immunohistochemistry was carried out to validate the results of the CHEK1 expression levels. Relative clinical features of BC patients were calculated with the CHEK1 expression levels to determine their diagnostic value. The mRNA levels of CHEK1 were higher in 1,089 cases of BC tissues than in 291 cases of non-BC tissues. We observed that the mRNA levels of CHEK1 are related to the clinical stages of BC patients (P = 0.008) and are also significant for overall survival (HR = 1.6, P = 0.0081). Using the immunohistochemistry method, we calculated and confirmed, using Fisher's exact test (P < 0.001), that a high-level CHEK1 protein is exhibited in BC tissues. Overexpressed CHEK1 mRNA promotes the occurrence of BC. Also, up-regulated CHEK1 could serve as an independent risk biomarker in BC patients' prognoses.