Advances of Osteosarcoma Models for Drug Discovery and Precision Medicine

Menin inhibitor MI-503 exhibits potent anti-cancer activity in osteosarcoma

Small molecule Menin inhibitor recently has emerged as a new therapeutic by targeting the interaction of histone methyltransferase MLL1 (KMT2A) with Menin. MLL1 is associated with aggressive osteosarcoma (OS) in young adults. The purpose of the study is to explore whether Menin inhibitors have therapeutic effects in OS.To investigate the anti-OS activity of the Menin inhibitor MI-503 in vitro, we performed CCK-8 cell growth and colony formation assay. Cellular thermal shift assay was used to test whether MI-503 binds to Menin in osteosarcoma cells. The expression of oncogenes in MI-503 treated cells were detected by western blotting and Quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay. Finally, we established the OS subcutaneous xenograft mice model to study the anti-OS effect of MI-503 in vivo.The results showed that MI-503 dose-dependently suppressed cell proliferation in 6 OS cell lines, including 143B, HOS, Saos-2, SKES1, MG-63, and U2OS. 143B is the most sensitive cell line with EC50 value 0.13 µM. Cellular thermal shift assay showed that MI-503 binds cellular Menin. RT-qPCR assay showed that MI-503 suppressed the expression of Mcl-1 and c-Myc in 143B cells. Western blotting result showed that MI-503 markedly suppressed the H3K4 methylation, significantly suppressed the expression of Mcl-1 and c-Myc, and increased the expression of p27 and cl-PARP in 143B and Saos-2 cells. In a study with 143B cell-derived xenograft model, we found that MI-503 profoundly inhibited OS tumor growth in mice. Immunohistochemistry (IHC) study showed that MI-503 suppressed the H3K4 methylation and inhibited the expression of the cell proliferation biomarker Ki67 in 143B OS xenograft tissue.Overall, our findings demonstrated the potent anti-OS activity of MI-503 in both in vitro and in vivo models, which also indicated that Menin inhibitor may be a prospective therapeutic strategy for human OS.

Advancements in nanoparticles-based therapeutic approaches for osteosarcoma: Insights from catechins-modified selenium-doped hydroxyapatite: A review

Osteosarcoma is common in all age groups, and a multifaceted strategy that includes radiation therapy, surgical intervention and chemotherapy remains the conventional treatment for osteosarcoma. Existing therapies typically result in recurring malignancies and postsurgical bone abnormalities, necessitating novel strategies for targeted drug administration and bone defects. The most significant components that are crucial for maintain strong bones include trace elements, calcium, selenium, and vitamins K and D. A deficiency in selenium advances the risk of cancer in many organs, including the bones. The progression of an effective technique such as a "local delivery system" is required to efficiently deliver the antioxidant to the targeted tissues for treatment as the circulatory system is unable to convey an adequate concentration of catechin to the regions of bone abnormalities. In this regard the combination of selenium and catechin with mesoporous hydroxyapatite nanoparticles displays promise as a nanoscale delivery method, offering an ideal approach to use it for the treatment and prevention of bone-related diseases. Therefore, this review mainly focusing in exploring the therapeutic potential of catechins-modified selenium-doped hydroxyapatite nanomaterials, chitosan-PEG-folate-Fe (III) complexes as nanocarriers for epigallocatechin-3-gallate, and catechin-conjugated mesoporous hydroxyapatite nanoparticle, highlighting their novel functions as nano-antioxidants with improved osteogenic characteristics in osteosarcoma treatment.

Recent Issues in the Development and Application of Targeted Therapies with Respect to Individual Animal Variability

This literature review explores the impact of molecular, genetic, and environmental factors on the efficacy of targeted therapies in veterinary medicine. Relevant studies were identified through systematic searches of PubMed, Web of Science, Scopus, and ScienceDirect using keywords such as "species-specific treatment strategies", "signalling pathways", "epigenetic and paragenetic influences", "targeted therapies", "veterinary medicine", "genetic variation", and "free radicals and oxidative stress". Inclusion criteria included studies focusing on species-specific therapeutic responses, genetic influences, and oxidative stress. To ensure that only the most recent and relevant evidence was included, only peer-reviewed publications from the last two decades were considered. Each study selected for analysis was critically appraised, with a particular emphasis on methodological quality, experimental design, and scientific contribution to the understanding of how environmental and biological factors influence therapeutic outcomes. A special emphasis was placed on studies that used a comparative, cross-species approach to assess variability in therapeutic responses and potential adverse effects. The review synthesises evidence on the role of epigenetic and paragenetic factors and highlights the importance of cross-species studies to understand how environmental and biological factors influence treatment outcomes. By highlighting genetic variation, oxidative stress, and individual species differences, the review argues for personalised and species-specific therapeutic approaches. The review emphasises that such an approach would improve veterinary care and inform future research aimed at optimising targeted therapies, ultimately leading to better animal health and treatment efficacy. A key contribution of the review is its emphasis on the need for more personalised treatment protocols that take into account individual genetic profiles and environmental factors; it also calls for a greater integration of cross-species studies.

Cucurbitacin B modulates M2 macrophage differentiation and attenuates osteosarcoma progression via PI3K/AKT pathway

Osteosarcoma is a common malignant bone tumour characterised by an aggressive metastatic potential. The tumour microenvironment, particularly the M2-polarised macrophages, is crucial for tumour progression. Cucurbitacin B (CuB), a triterpenoid derivative, is recognised for its anti-inflammatory and antitumour properties. This study investigates CuB and its effect on M2 macrophage differentiation and osteosarcoma progression, aiming to contribute to new treatment strategies. In vitro, THP-1 monocytes were stimulated with PMA, IL-13 and IL-4 to induce differentiation into M2 macrophages. Additionally, the influence of CuB on the proliferation, migration and invasion of osteosarcoma cells in the context of M2 macrophages was scrutinised. Crucial signalling pathways, especially the PI3K/AKT pathway, affected by CuB were identified and validated. In vivo, the osteosarcoma model was employed to gauge the effects of CuB on tumour weight, lung metastasis, angiogenesis, cell proliferation and M2 macrophage markers. The results showed that CuB inhibited M2 macrophage differentiation, leading to reduced proliferation, migration and invasion of osteosarcoma cells. CuB manifested an inhibitory effect on the PI3K/AKT pathway during the differentiation of M2 macrophages. In mouse models, CuB markedly reduced the tumour weight and the number of lung metastases. It also reduced the expression of angiogenesis and cell proliferation markers in tumour tissues, decreased the quantity of M2 macrophages and their associated markers and pathway proteins. In conclusion, CuB impedes osteosarcoma progression by inhibiting M2 macrophage differentiation via the PI3K/AKT pathway, presenting the potential for therapeutic advancements in osteosarcoma treatment.