Role of RANKL in cancer development and metastasis

Melatonin Interplay in Physiology and Disease-The Fountain of Eternal Youth Revisited

Melatonin (N-acetyl-5-methoxytryptamine) is a hormone associated with the regulation of biological rhythms. The indoleamine is secreted by the pineal gland during the night, following a circadian rhythm. The highest plasmatic levels are reached during the night, whereas the lowest levels are achieved during the day. In addition to the pineal gland, other organs and tissues also produce melatonin, like, for example, the retina, Harderian glands, gut, ovaries, testes, skin, leukocytes, or bone marrow. The list of organs is extensive, including the cerebellum, airway epithelium, liver, kidney, adrenals, thymus, thyroid, pancreas, carotid body, placenta, and endometrium. At all these locations, the availability of melatonin is intended for local use. Interestingly, a decline of the circadian amplitude of the melatonin secretion occurs in old subjects in comparison to that found in younger subjects. Moreover, genetic and environmental factors are the primary causes of diseases, and oxidative stress is a key contributor to most pathologies. Numerous studies exist that show interesting effects of melatonin in different models of disease. Impairment in its secretion might have deleterious consequences for cellular physiology. In this regard, melatonin is a natural compound that is a carrier of a not yet completely known potential that deserves consideration. Thus, melatonin has emerged as a helpful ally that could be considered as a guard with powerful tools to orchestrate homeostasis in the body, majorly based on its antioxidant effects. In this review, we provide an overview of the widespread actions of melatonin against diseases preferentially affecting the elderly.

Exosome-derived Uc.339 as a potential biomarker for bone metastasis from pulmonary adenocarcinoma

This study explored the role of Uc.339, which is a highly expressed genomic sequence in tumor cell-derived exosomes, in mediating bone metastasis from lung adenocarcinoma. By integrating clinical samples, in vitro experiments, and in vivo murine models, we elucidated the molecular mechanisms underlying this process. Clinical blood samples from patients with lung adenocarcinoma revealed elevated Uc.339 expression in exosomes, particularly in those with bone metastasis. In vitro experiments using A549 cell-derived exosomes demonstrated an increase in osteoclast formation, implicating Uc.339 in bone microenvironment modulation. Mechanistically, Uc.339 functions as a decoy for miR-339-3p, disrupting the gene expression balance. In vivo experiments in a murine model confirmed disrupted bone microstructure in the presence of elevated Uc.339, alongside altered expression of key regulators, including SQSTM1, RANKL, nuclear factor kappa B, and miR-339-3p. Our findings underscore the systemic impact of Uc.339 in exosomes, suggesting its potential as both a biomarker and a mediator of bone metastasis. Moreover, the identified molecular alterations provide potential therapeutic targets for managing bone metastasis in patients with lung adenocarcinoma. This study contributes to a deeper understanding of the complex interplay between cancer cells and the bone microenvironment, paving the way for targeted interventions and improved clinical outcomes.

RANKL blockade inhibits cancer growth through reversing the tolerogenic profile of tumor-infiltrating (plasmacytoid) dendritic cells

BACKGROUND

Originally identified for its involvement in bone remodeling, accumulating data emerged in the past years indicating that receptor activator of nuclear factor κB ligand (RANKL) actually acts as a multifunctional soluble molecule that influences various physiological and pathological processes. Regarding its role in carcinogenesis, while direct effects on tumor cell behavior have been precisely characterized, the impact of the RANKL/RANK system (and its inhibition) on the intratumoral immune landscape remains unclear.

METHODS

After various in silico/in situ/in vitro analyses, the immunotherapeutic efficacy of RANKL blockade (alone and in combination with immune checkpoint inhibitors (anti-programmed cell death protein-1 (PD-1)) or doxorubicin/paclitaxel-based chemotherapy) was investigated using different syngeneic mouse models of triple-negative breast cancer (4T1, 67NR and E0771). Isolated from retrieved tumors, 14 immune cell (sub)populations, along with the activation status of antigen-presenting cells, were thoroughly analyzed in each condition. Finally, the impact of RANKL on the functionality of both dendritic cells (DC) and plasmacytoid dendritic cells (pDC) was determined.

RESULTS

A drastic tumor growth inhibition was reproductively observed following RANKL inhibition. Strikingly, this antitumor activity was not detected in immunocompromised mice, demonstrating its dependence on the adaptive immune responses and justifying the diverse enriched signatures linked to immune cell regulation/differentiation detected in RANKLhigh-expressing human neoplasms. Interestingly, neoadjuvant chemotherapy (but not PD-1 checkpoint inhibition) potentiated the anticancer effects of RANKL blockade by priming effector T cells and increasing their infiltration within the tumor microenvironment. Mechanistically, we highlighted that RANKL indirectly promotes regulatory T cell differentiation and suppressive function by inhibiting the mTOR signaling pathway on antigen-presenting cells.

CONCLUSIONS

Taken together, this study provides insight into the role of RANKL/RANK axis in immune tolerance, demonstrates the significant impact of RANKL-dependent impairment of T cell-DC/pDC crosstalk on tumor development and, ultimately, supports that this ligand could be an interesting actionable target for cancer immunotherapy.

Implications of Mineralization Biomarkers in Breast Cancer Outcomes Beyond Calcifications

The aim of this work was to explore the biomarkers associated with epithelial to mesenchymal transition (EMT) and mineralization processes as new prognostic factors across different breast cancer phenotypes. To this end, 133 breast biopsies, including benign and malignant lesions, with or without microcalcifications, were retrospectively collected. Immunohistochemical analysis was performed to evaluate the expression of vimentin, BMP-2, BMP-4, RANKL, Runx2, OPN, PTX3, and SDF-1, while Kaplan-Meier plots were used to assess their prognostic impact on overall survival in a dataset of 2976 breast cancer patients. The expression of vimentin, BMP-2, BMP-4, and SDF-1 was significantly higher in malignant lesions compared to benign ones, regardless of the presence of microcalcifications. Notably, these markers showed no correlation with traditional prognostic factors, such as tumor grade or hormone receptor status. The bioinformatics analysis provided valuable insights into the possible prognostic and therapeutic significance of BMP-2, BMP-4, SDF-1, and vimentin in breast cancer. In fact, all these biomarkers impact on the overall survival in specific molecular breast cancer types. In addition, high expression of SDF-1 and vimentin is able to predict the response to chemotherapy. The findings here reported suggest that vimentin, BMP-2, BMP-4, and SDF-1 could be independent prognostic biomarkers in breast cancer, providing insights beyond traditional clinical factors.

Unveiling the therapeutic promise: exploring Lysophosphatidic Acid (LPA) signaling in malignant bone tumors for novel cancer treatments

Malignant bone tumors, including primary bone cancer and metastatic bone tumors, are a significant clinical challenge due to their high frequency of presentation, poor prognosis and lack of effective treatments and therapies. Bone tumors are often accompanied by skeletal complications such as bone destruction and cancer-induced bone pain. However, the mechanisms involved in bone cancer progression, bone metastasis and skeletal complications remain unclear. Lysophosphatidic acid (LPA), an intercellular lipid signaling molecule that exerts a wide range of biological effects mainly through specifically binding to LPA receptors (LPARs), has been found to be present at high levels in the ascites of bone tumor patients. Numerous studies have suggested that LPA plays a role in primary malignant bone tumors, bone metastasis, and skeletal complications. In this review, we summarize the role of LPA signaling in primary bone cancer, bone metastasis and skeletal complications. Modulating LPA signaling may represent a novel avenue for future therapeutic treatments for bone cancer, potentially improving patient prognosis and quality of life.

Using machine learning approach for screening metastatic biomarkers in colorectal cancer and predictive modeling with experimental validation

Colorectal cancer (CRC) liver metastasis accounts for the majority of fatalities associated with CRC. Early detection of metastasis is crucial for improving patient outcomes but can be delayed due to a lack of symptoms. In this research, we aimed to investigate CRC metastasis-related biomarkers by employing a machine learning (ML) approach and experimental validation. The gene expression profile of CRC patients with liver metastasis was obtained using the GSE41568 dataset, and the differentially expressed genes between primary and metastatic samples were screened. Subsequently, we carried out feature selection to identify the most relevant DEGs using LASSO and Penalized-SVM methods. DEGs commonly selected by these methods were selected for further analysis. Finally, the experimental validation was done through qRT-PCR. 11 genes were commonly selected by LASSO and P-SVM algorithms, among which seven had prognostic value in colorectal cancer. It was found that the expression of the MMP3 gene decreases in stage IV of colorectal cancer compared to other stages (P value < 0.01). Also, the expression level of the WNT11 gene was observed to increase significantly in this stage (P value < 0.001). It was also found that the expression of WNT5a, TNFSF11, and MMP3 is significantly lower, and the expression level of WNT11 is significantly higher in liver metastasis samples compared to primary tumors. In summary, this study has identified a set of potential biomarkers for CRC metastasis using ML algorithms. The findings of this research may provide new insights into identifying biomarkers for CRC metastasis and may potentially lay the groundwork for innovative therapeutic strategies for treatment of this disease.

A randomized trial comparing LY01011, biosimilar candidate, with the reference product denosumab (Xgeva®) in healthy Chinese subjects

Background

Complications of bone metastases such as skeletal-related events lead to the impaired functional status and quality of life including death in patients with bone metastasis from solid tumors. Denosumab (XGEVA®) is indicated for the prevention of skeletal-related events in bone metastasis patients with solid tumors. The biosimilar product LY01011, a fully human anti-receptor activator of nuclear factor kappa-B ligand monoclonal antibody, was developed to be compared with the reference product denosumab.

Material and methods

A randomized, double-blind, single-dose, parallel-controlled phase 1 study was conducted in healthy Chinese subjects. A total of 168 enrolled subjects were randomly assigned in a 1:1 ratio to receive a single 120 mg dose of LY01011 (n = 85) or denosumab (n = 83) subcutaneously. The primary pharmacokinetic (PK) parameters, including maximum plasma concentration (Cmax) and area under the concentration-time curve from time zero to last quantifiable concentration (AUC0→t), were collected and measured for evaluation. Other secondary PK parameters included AUC0- ∞, Tmax, CL/F, λz, t1/2, Vd/F, etc. Pharmacodynamics (PD), safety and immunogenicity profiles were also accounted for data analysis.

Results

The geometric mean ratios (GMRs) of LY01011 and denosumab for the primary PK parameters such as Cmax and AUC0→t were 98.13% and 100.32%. The 90% confidence intervals (CIs) were all within the acceptance range of 80%-125%. The GMRs of the PD parameters including AUEC0→t and Emax were 98.71% and 99.80%, which fell within the pre-defined acceptance range of 80%-125%. The results also demonstrated PK similarity even if Cmax and AUC0→∞ had been used as primary endpoints. Safety profiles were tolerable and similar between groups. 4 (4.7%) and 2 (2.4%) subjects had experienced Grade 3 or above treatment-emergent adverse events (TEAEs) in LY01011 group and denosumab group. 3 subjects were reported to have serious adverse events (SAEs). None of the Grade 3 or above TEAEs and SAEs were related to the study drug, LY01011. No subject was tested anti-drug antibody (ADA) positive in both groups prior to the study drug administration. Following the study drug administration, only one subject in denosumab group was tested ADA positive, whereas no subject with ADA positive was reported in LY01011 group. No neutralizing antibody (Nab) was detected in either group throughout the study.

Conclusions

The study demonstrated PK and PD similarity of LY01011, a denosumab biosimilar, to denosumab in healthy Chinese subjects, with comparable safety and immunogenicity profiles.

Immunotherapy as a potential treatment approach for currently incurable bone metastasis

Once cancer metastasizes to the bone, the prognosis of cancer patients becomes extremely poor. Unfortunately, the current most successful treatment for bone metastasis can extend their survival by only a few months. Although recent studies have revealed promising impacts of cancer immunotherapies, their treatment efficacy on bone metastatic diseases remains controversial. Therefore, in this review, we discussed (i) preclinical and clinical evidence of the immunotherapeutic strategies for cancer bone metastasis, mainly focusing on cell-based immunotherapy, cytokine-based immunotherapy, and immune checkpoint blockade, and (ii) current shortcomings of immunotherapy for bone metastasis and their potential future directions. Although the evidence on treatment efficacy and safety, as well as long-term effects, is limited, immunotherapies could induce partial or complete remissions in a few cancer patients with bone metastasis. However, there are still hurdles, such as the immunosuppressive nature of the bone marrow microenvironment and poor distribution of cell-based immunotherapies to bone, that need to be overcome to enhance the treatment efficacy of immunotherapies on bone metastasis. While it is apparent that further investigation is needed regarding immunotherapeutic treatment efficacy in patients with bone metastasis, this therapy may prove to be clinically novel in this subset of cancer patients.

Multifunctionality of Calebin A in inflammation, chronic diseases and cancer

Chronic diseases including cancer have high case numbers as well as mortality rates. The efficient treatment of chronic diseases is a major ongoing medical challenge worldwide, because of their complexity and many inflammatory pathways such as JNK, p38/MAPK, MEK/ERK, JAK/STAT3, PI3K and NF-κB among others being implicated in their pathogenesis. Together with the versatility of chronic disease classical mono-target therapies are often insufficient. Therefore, the anti-inflammatory as well as anti-cancer capacities of polyphenols are currently investigated to complement and improve the effect of classical anti-inflammatory drugs, chemotherapeutic agents or to overcome drug resistance of cancer cells. Currently, research on Calebin A, a polyphenolic component of turmeric (Curcuma longa), is becoming of growing interest with regard to novel treatment strategies and has already been shown health-promoting as well as anti-tumor properties, including anti-oxidative and anti-inflammatory effects, in diverse cancer cells. Within this review, we describe already known anti-inflammatory activities of Calebin A via modulation of NF-κB and its associated signaling pathways, linked with TNF-α, TNF-β and COX-2 and further summarize Calebin A's tumor-inhibiting properties that are known up to date such as reduction of cancer cell viability, proliferation as well as metastasis. We also shed light on possible future prospects of Calebin A as an anti-cancer agent.

Bone Metastasis and Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer (NSCLC): Microenvironment and Possible Clinical Implications

Patients with non-small cell lung cancer (NSCLC) develop bone metastasis (BoM) in more than 50% of cases during the course of the disease. This metastatic site can lead to the development of skeletal related events (SREs), such as severe pain, pathological fractures, spinal compression, and hypercalcemia, which reduce the patient’s quality of life. Recently, the treatment of advanced NSCLC has radically changed due to the advent of immunotherapy. Immune checkpoint inhibitors (ICI) alone or in combination with chemotherapy have become the main therapeutic strategy for advanced or metastatic NSCLC without driver gene mutations. Since survival has increased, it has become even more important to treat bone metastasis to prevent SRE. We know that the presence of bone metastasis is a negative prognostic factor. The lower efficacy of immunotherapy treatments in BoM+ patients could be induced by the presence of a particular immunosuppressive tumor and bone microenvironment. This article reviews the most important pre-clinical and clinical scientific evidence on the reasons for this lower sensitivity to immunotherapy and the need to combine bone target therapies (BTT) with immunotherapy to improve patient outcome.

mTORC1-Inhibition Potentiating Metabolic Block by Tyrosine Kinase Inhibitor Ponatinib in Multiple Myeloma

Simple Summary

From a screen for metabolic inhibition by a panel of approved anticancer drugs and combining the lead compound with a mammalian target of rapamycin complex 1 (mTORC1) inhibitor, we demonstrated that the combination of ponatinib and sirolimus leads to synergistic tumor growth inhibition in a mouse xenograft tumor model of multiple myeloma. The rationale of combining the two drugs was to prevent metabolic escape due to glycolysis reprogramming and residual oxidative phosphorylation (OXPHOS). The robust increases in reactive oxygen species (ROS) due to a block in glycolysis were shown to be the lead contributor of cell viability loss. The drug combination in the doses used displayed no overt toxicity in the treated animals.

Abstract

Studies in targeting metabolism in cancer cells have shown the flexibility of cells in reprogramming their pathways away from a given metabolic block. Such behavior prompts a combination drug approach in targeting cancer metabolism, as a single compound may not address the tumor intractability. Overall, mammalian target of rapamycin complex 1 (mTORC1) signaling has been implicated as enabling metabolic escape in the case of a glycolysis block. From a library of compounds, the tyrosine kinase inhibitor ponatinib was screened to provide optimal reduction in metabolic activity in the production of adenosine triphosphate (ATP), pyruvate, and lactate for multiple myeloma cells; however, these cells displayed increasing levels of oxidative phosphorylation (OXPHOS), enabling them to continue generating ATP, although at a slower pace. The combination of ponatinib with the mTORC1 inhibitor, sirolimus, blocked OXPHOS; an effect also manifested in activity reductions for hexokinase 2 (HK2) and glucose-6-phosphate isomerase (GPI) glycolysis enzymes. There were also remarkably higher levels of reactive oxygen species (ROS) produced in mouse xenografts, on par with increased glycolytic block. The combination of ponatinib and sirolimus resulted in synergistic inhibition of tumor xenografts with no overt toxicity in treated mice for kidney and liver function or maintaining weight.

The Roles of RANK/RANKL/OPG in Cardiac, Skeletal, and Smooth Muscles in Health and Disease

Although their physiology and functions are very different, bones, skeletal and smooth muscles, as well as the heart have the same embryonic origin. Skeletal muscles and bones interact with each other to enable breathing, kinesis, and the maintenance of posture. Often, muscle and bone tissues degenerate synchronously under various conditions such as cancers, space travel, aging, prolonged bed rest, and neuromuscular diseases. In addition, bone tissue, skeletal and smooth muscles, and the heart share common signaling pathways. The RANK/RANKL/OPG pathway, which is essential for bone homeostasis, is also implicated in various physiological processes such as sarcopenia, atherosclerosis, and cardiovascular diseases. Several studies have reported bone-skeletal muscle crosstalk through the RANK/RANKL/OPG pathway. This review will summarize the current evidence indicating that the RANK/RANKL/OPG pathway is involved in muscle function. First, we will briefly discuss the role this pathway plays in bone homeostasis. Then, we will present results from various sources indicating that it plays a physiopathological role in skeletal, smooth muscle, and cardiac functions. Understanding how the RANK/RANKL/OPG pathway interferes in several physiological disorders may lead to new therapeutic approaches aimed at protecting bones and other tissues with a single treatment.

Immune Checkpoint Inhibitor Therapy for Bone Metastases: Specific Microenvironment and Current Situation

The treatment of bone metastases is a thorny issue. Immunotherapy may be one of the few hopes for patients with unresectable bone metastases. Immune checkpoint inhibitors are the most commonly used immunotherapy drugs currently. In this review, the characteristics and interaction of bone metastases and their immune microenvironment were systematically discussed, and the relevant research progress of the immunological mechanism of tumor bone metastasis was reviewed. On this basis, we expounded the clinical application of immune checkpoint inhibitors for bone metastasis of common tumors, including non-small-cell lung cancer, renal cell carcinoma, prostate cancer, melanoma, and breast cancer. Then, the deficiencies and limitations in current researches were summarized. In-depth basic research on bone metastases and optimization of clinical treatment is needed.