Convallatoxin suppresses osteosarcoma cell proliferation, migration, invasion, and enhances osteogenic differentiation by downregulating parathyroid hormone receptor 1 (PTHR1) expression and inactivating Wnt/β-catenin pathway

Protein Kinase C and Matrix Metalloproteinases Expression Using Phorbol Myristate Acetate in Degenerative Intervertebral Disc Cells

Background

Degeneration of nucleus pulposus (NP) cells involves multiple factors. The relationship between the canonical Wnt/β-catenin signaling pathway and matrix metalloproteinases (MMPs) is important in cellular senescence. Protein kinase C (PKC), an intermediate of the non-canonical Wnt pathway stimulated by phorbol myristate acetate (PMA), possibly prevents NP cell senescence, although not yet demonstrated in human-based studies. This study aimed to investigate the effect of PMA stimulation on the non-canonical and canonical Wnt pathways and MMP expression in human NP cells to ascertain its inhibitory effects on the senescence of NP cells.

Methods

Human disc tissues of Pfirrmann grades 1 and 2 were collected from patients during spinal surgery and subsequently cultured. Protein and ribonucleic acid (RNA) were isolated from NP cells treated with PMA (400 nM) for 24 hours. Expression of MMP1, MMP13, tissue inhibitor of matrix metalloproteinase 1 (TIMP1), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5), transient receptor potential vanilloid 4 (TRPV4), interleukin-6 (IL-6), and β-catenin were detected using western blot analysis. Messenger RNA (mRNA) expression of type II collagen and glycosaminoglycan (GAG) were analyzed using reverse transcription polymerase chain reaction. IL-6 and prostaglandin E2 (PGE2) levels were measured using enzyme-linked immunosorbent assay.

Results

Expression of PKC-δ (intermediate of the non-canonical Wnt pathway) and β-catenin (intermediate of the canonical Wnt pathway) was increased by PMA treatment. The mRNA levels of type II collagen and GAG increased; however, their protein levels were not altered. PMA treatment increased the expression of MMP1, TIMP1, ADAMTS5, IL-6, PGE2, and TRPV4; however, the expression of MMP13 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was unaltered.

Conclusions

PMA activated PKC-δ, affecting the non-canonical Wnt pathway; however, its effect on β-catenin in the canonical Wnt pathway was limited. β-catenin activation through the TRPV4 channel led to increased expression of MMP1 and ADAMTS5 and that of IL-6 and PGE2 owing to NF-κB expression. Consequently, the degeneration of NP cells was not prevented.

Effects of Doxorubicin, Epirubicin, and Liposomal Doxorubicin (Anthracycline) on cardiac function in patients with osteosarcoma and their influencing factors

OBJECTIVE

The objective of this study was to investigate the impact of Doxorubicin, Epirubicin, and Liposomal Doxorubicin (Anthracycline) on cardiac function in osteosarcoma patients and analyze the factors influencing this effect.

METHODS

A retrospective study was conducted on 165 osteosarcoma patients admitted to our hospital from January 2020 to December 2022. Based on the chemotherapy regimen, the patients were divided into two groups: the control group (n = 62) treated with Cisplatin and cyclophosphamide, and the observation group (n = 103) treated with Doxorubicin, Epirubicin, and Liposomal Doxorubicin (Anthracycline). The general records of both groups were analyzed, and left ventricular ejection fraction (LVEF) was evaluated through echocardiography before and after chemotherapy. Blood cTnT and CK-MB levels were measured using immunoluminescence. The incidence of adverse reactions during chemotherapy was also analyzed. Univariate analysis was performed to identify patients with cardiotoxic events, and multiple logistic regression analysis was done to study the effects of Doxorubicin, Epirubicin, Liposomal Doxorubicin, and their dosages on cardiotoxicity in patients.

RESULTS

The general records between the two groups showed no significant differences (P > 0.05). However, at the fourth cycle of chemotherapy, the observation group exhibited a lower LVEF (P < 0.05), and a higher percentage of LVEF decrease compared to the control group (P < 0.05). Moreover, the observation group had higher levels of blood cTnT and CK-MB (P < 0.05). The incidence of cardiotoxicity in the observation group was also higher (P < 0.05), but no significant differences were seen in other adverse reaction rates (P > 0.05). The occurrence of cardiotoxicity was found to be related to the choice and dosage of chemotherapy drugs (P < 0.05), but not significantly correlated with age, sex, and mediastinal irradiation in patients (P > 0.05). Furthermore, the use of Doxorubicin, Epirubicin, and Liposomal Doxorubicin in chemotherapy, as well as an increase in their dosages, was found to elevate the risk of cardiotoxicity in osteosarcoma patients (P < 0.05). However, age, sex, and mediastinal radiation were not significantly associated with cardiotoxicity in osteosarcoma patients (P > 0.05).

CONCLUSION

We demonstrated that Doxorubicin, Epirubicin, Liposomal Doxorubicin (Anthracycline), and other drugs adversely affected cardiac function in osteosarcoma patients, increasing the risk of cardiac toxicity. Therefore, close monitoring of cardiac function during chemotherapy is crucial, and timely adjustments to the chemotherapy regimen are necessary. In addition, rational control of drug selection and dosage is essential to minimize the occurrence of cardiac toxicity.

β-Sitosterol suppresses hepatocellular carcinoma growth and metastasis via FOXM1-regulated Wnt/β-catenin pathway

β-Sitosterol is a natural compound with demonstrated anti-cancer properties against various cancers. However, its effects on hepatocellular carcinoma (HCC) and the underlying mechanisms are not well understood. This study aims to investigate the impact of β-sitosterol on HCC. In this study, we investigated the effects of β-sitosterol on HCC tumour growth and metastasis using a xenograft mouse model and a range of molecular analyses, including bioinformatics, real-time PCR, western blotting, lentivirus transfection, CCK8, scratch and transwell assays. The results found that β-sitosterol significantly inhibits HepG2 cell proliferation, migration and invasion both in vitro and in vivo. Bioinformatics analysis identifies forkhead box M1 (FOXM1) as a potential target for β-sitosterol in HCC treatment. FOXM1 is upregulated in HCC tissues and cell lines, correlating with poor prognosis in patients. β-Sitosterol downregulates FOXM1 expression in vitro and in vivo. FOXM1 overexpression mitigates β-sitosterol's inhibitory effects on HepG2 cells. Additionally, β-sitosterol suppresses epithelial-mesenchymal transition (EMT) in HepG2 cells, while FOXM1 overexpression promotes EMT. Mechanistically, β-sitosterol inhibits Wnt/β-catenin signalling by downregulating FOXM1, regulating target gene transcription related to HepG2 cell proliferation and metastasis. β-Sitosterol shows promising potential as a therapeutic candidate for inhibiting HCC growth and metastasis through FOXM1 downregulation and Wnt/β-catenin signalling inhibition.

Targeting signaling pathways in osteosarcoma: Mechanisms and clinical studies

Osteosarcoma (OS) is a highly prevalent bone malignancy among adolescents, accounting for 40% of all primary malignant bone tumors. Neoadjuvant chemotherapy combined with limb-preserving surgery has effectively reduced patient disability and mortality, but pulmonary metastases and OS cells' resistance to chemotherapeutic agents are pressing challenges in the clinical management of OS. There has been an urgent need to identify new biomarkers for OS to develop specific targeted therapies. Recently, the continued advancements in genomic analysis have contributed to the identification of clinically significant molecular biomarkers for diagnosing OS, acting as therapeutic targets, and predicting prognosis. Additionally, the contemporary molecular classifications have revealed that the signaling pathways, including Wnt/β-catenin, PI3K/AKT/mTOR, JAK/STAT3, Hippo, Notch, PD-1/PD-L1, MAPK, and NF-κB, have an integral role in OS onset, progression, metastasis, and treatment response. These molecular classifications and biological markers have created new avenues for more accurate OS diagnosis and relevant treatment. We herein present a review of the recent findings for the modulatory role of signaling pathways as possible biological markers and treatment targets for OS. This review also discusses current OS therapeutic approaches, including signaling pathway-based therapies developed over the past decade. Additionally, the review covers the signaling targets involved in the curative effects of traditional Chinese medicines in the context of expression regulation of relevant genes and proteins through the signaling pathways to inhibit OS cell growth. These findings are expected to provide directions for integrating genomic, molecular, and clinical profiles to enhance OS diagnosis and treatment.

Advances in Osteosarcoma

PURPOSE OF REVIEW

This article gives a brief overview of the most recent developments in osteosarcoma treatment, including targeting of signaling pathways, immune checkpoint inhibitors, drug delivery strategies as single or combined approaches, and the identification of new therapeutic targets to face this highly heterogeneous disease.

RECENT FINDINGS

Osteosarcoma is one of the most common primary malignant bone tumors in children and young adults, with a high risk of bone and lung metastases and a 5-year survival rate around 70% in the absence of metastases and 30% if metastases are detected at the time of diagnosis. Despite the novel advances in neoadjuvant chemotherapy, the effective treatment for osteosarcoma has not improved in the last 4 decades. The emergence of immunotherapy has transformed the paradigm of treatment, focusing therapeutic strategies on the potential of immune checkpoint inhibitors. However, the most recent clinical trials show a slight improvement over the conventional polychemotherapy scheme. The tumor microenvironment plays a crucial role in the pathogenesis of osteosarcoma by controlling the tumor growth, the metastatic process and the drug resistance and paved the way of new therapeutic options that must be validated by accurate pre-clinical studies and clinical trials.