Multiple myeloma is a hematologic malignancy of plasma cells that causes bone-destructive lesions and associated skeletal-related events (SREs). The pathogenesis of myeloma-related bone disease (MBD) is the imbalance of the bone-remodeling process, which results from osteoclast activation, osteoblast suppression, and the immunosuppressed bone marrow microenvironment. Many important signaling cascades, including the RANKL/RANK/OPG axis, Notch signaling, the Wnt/β-Catenin signaling pathways, and signaling molecules, such as DKK-1, sclerostin, osteopontin, activin A, chemokines, and interleukins are involved and play critical roles in MBD. Currently, bisphosphonate and denosumab are the gold standard for MBD prevention and treatment. As the molecular mechanisms of MBD become increasingly well understood, novel agents are being thoroughly explored in both preclinical and clinical settings. Herein, we will provide an updated overview of the pathogenesis of MBD, summarize the clinical management and guidelines, and discuss novel bone-modifying therapies for further management of MBD.

Osteolytic bone lesions are one of the central features of multiple myeloma (MM) and lead to bone pain, fractures, decreased quality of life, and decreased survival. Dysfunction of the osteoclast (OC)/osteoblast (OB) axis plays a key role in the development of myeloma-associated osteolytic lesions. Many signaling pathways and factors are associated with myeloma bone diseases (MBDs), including the RANKL/OPG and NF-κB pathways. NRF2, a master regulator of inflammatory signaling, might play a role in the regulation of bone metabolism via anti-inflammatory signaling and decreased reactive oxygen species (ROS) levels. The loss of NRF2 expression in OCs reduced bone mass via the RANK/RANKL pathway and other downstream signaling pathways that affect osteoclastogenesis. The NRF2 level in OBs could interfere with interleukin (IL)-6 expression, which is associated with bone metabolism and myeloma cells. In addition to direct impact on OCs and OBs, the activity of NRF2 on myeloma cells and mesenchymal stromal cells influences the inflammatory stress/ROS level in these cells, which has an impact on OCs, OBs, and osteocytes. The interaction between these cells and OCs affects the osteoclastogenesis of myeloma bone lesions associated with NRF2. Therefore, we have reviewed the effects of NRF2 on OCs and OBs in MBDs.

Metronomic chemotherapy inhibits tumor growth by continuous administration of lower-dose chemotherapy. Our study aimed to demonstrate the outcomes of metronomic chemotherapy with tegafur–uracil in locally advanced head and neck squamous cell carcinoma (LA HNSCC). This was a retrospective study including 240 patients with LA HNSCC. After standard treatment, 96 patients were further treated with metronomic tegafur-uracil, and 144 patients were not. No statistical differences were found between both groups with regard to sex, clinical stage, or primary treatment choice. There were more hypopharyngeal cancers and more patients with poor clinicopathological features, including lymphovascular invasion, extranodal extension, and positive margins in the tegafur–uracil group. The median follow-up duration was 31.16 months. Overall survival (OS) was not reached in the tegafur–uracil group and was 54.1 months in the control group (p = 0.008). The median disease-free survival (DFS) was 54.5 months in the tegafur–uracil group and 34.4 months in the control group (p = 0.03). Neither group reached distant metastasis-free survival (DMFS, p = 0.02). In patients with LA HNSCC, adding tegafur–uracil as metronomic chemotherapy after either curative surgery with adjuvant chemoradiotherapy or definitive concurrent chemoradiotherapy significantly improved the OS, DFS, and DMFS with tolerable adverse events.

Recurrent locally advanced or metastatic head and neck squamous cell carcinoma (HNSCC) is associated with dismal prognosis because of its highly invasive behavior and resistance to conventional intensive chemotherapy. The combination of targeted therapy and conventional chemotherapy has significantly improved clinical outcomes. In recent years, the development of immunotherapies, such as immune checkpoint inhibitors (ICIs), has further increased treatment responses and prolonged survival. However, the limited response rate, risk of immunotherapy-related adverse effects and high cost of immunotherapy make the identification of predictive markers to optimize treatment efficacy a critical issue. Biomarkers are biological molecules that have been widely utilized to predict treatment response to certain treatments and clinical outcomes or to detect disease. An ideal biomarker should exhibit good predictive ability, which can guide healthcare professionals to achieve optimal treatment goals and bring clinical benefit to patients. In this review, we summarized the results of recent and important studies focused on HNSCC ICI immunotherapy and discussed potential biomarkers including their strengths and limitations, aiming to gain more insight into HNSCC immunotherapy in real world clinical practice.

Background: Carfilzomib, the proteasome inhibitor, can increase the overall survival rate of multiple myeloma (MM) patients undergoing targeted therapy. However, relapse and toxicity present great challenges for such treatment, so an urgent need for effective combination therapy is necessary. Emodin is a natural chemical compound that inhibits the proliferation of various cancers and can effectively combine with other treatments. In this study, we evaluated the sensitizing effect of emodin combined with carfilzomib on MM cells. Methods: The cells were treated with emodin, carfilzomib, and a combination of drugs to determine their effects on cell proliferation and viability. The cell cycle distribution and reactive oxygen species (ROS) expression were measured by flow cytometry. The level of RNA and protein were analyzed through real-time qPCR and immunoblotting. Results: Emodin acted synergistically with carfilzomib to reduce the proliferation and viability of MM cell lines in vitro. Furthermore, the combination of emodin and carfilzomib increased ROS production, inducing apoptosis and autophagy pathways via caspase-3, PARP, p62, and LC3B. Conclusions: These results provide a molecular target for combination therapy in MM patients.

Multiple myeloma (MM) is a B-cell neoplasm characterized by clonal plasma–cell proliferation. The survival and prognosis of this condition have been significantly improved by treatment with active anti-MM drugs such as bortezomib or lenalidomide. Further, the discovery of novel agents has recently paved the way for new areas of investigation. However, MM, including myeloma-related bone diseases, remains fatal. Bone disease or bone destruction in MM is a consequence of skeletal involvement with bone pain, spinal cord compression, and bone fracture resulting from osteolytic lesions. These consequences affect disease outcomes, including patients’ quality of life and survival. Several studies have sought to better understand MM bone disease (MBD) through the classification of its molecular mechanisms, including osteoclast activation and osteoblast inhibition. Bisphosphonates and the receptor activator of the nuclear factor-kappa B (NF-κB) ligand (RANKL) inhibitor, denosumab, prevent skeletal-related events in MM. In addition, several other bone-targeting agents, including bone-anabolic drugs, are currently used in preclinical and early clinical evaluations. This review summarizes the current knowledge of the pathogenesis of MBD and discusses novel agents that appear very promising and will soon enter clinical development.