Inhibiting STAT3 in a murine model of human breast cancer-induced bone pain delays the onset of nociception

Peripheral Mechanism of Cancer-Induced Bone Pain

Cancer-induced bone pain (CIBP) is a type of ongoing or breakthrough pain caused by a primary bone tumor or bone metastasis. CIBP constitutes a specific pain state with distinct characteristics; however, it shares similarities with inflammatory and neuropathic pain. At present, although various therapies have been developed for this condition, complete relief from CIBP in patients with cancer is yet to be achieved. Hence, it is urgent to study the mechanism underlying CIBP to develop efficient analgesic drugs. Herein, we focused on the peripheral mechanism associated with the initiation of CIBP, which involves tissue injury in the bone and changes in the tumor microenvironment (TME) and dorsal root ganglion. The nerve-cancer and cancer-immunocyte cross-talk in the TME creates circumstances that promote tumor growth and metastasis, ultimately leading to CIBP. The peripheral mechanism of CIBP and current treatments as well as potential therapeutic targets are discussed in this review.

Transcriptome Sequencing Explores the Mechanism of Baicalin on Bone Cancer Pain

Introduction

Bone cancer pain is characterized by persistent pain, usually requiring drugs to relieve pain. Baicalin, a flavonoid compound extracted from Scutellaria baicalensis, which has antioxidant and analgesic effects. But, the effect of baicalin on bone cancer pain is unclear. Thus, this study aimed to explore the mechanism of baicalin on SD rats with bone cancer pain.

Materials and Methods

The MADB-106 breast cancer cells-induced bone pain model was constructed and carried out baicalin treatment. The therapeutic effect of baicalin on bone cancer pain model was observed by hematoxylin-eosin staining and immunofluorescence staining. We also performed transcriptome sequencing analysis of baicalin in the treatment of bone metastases. Also, RT-qPCR and ELISA were used to detect the expression levels of inflammation factors.

Results

After baicalin treatment, osteoclast activation was inhibited and the number of bone trabeculae was increased. Baicalin inhibited the protein expression level of inflammatory factors (IL-1β, IL-6, TNF-α and PGE2) in the bone metastases group. Based on the transcriptome sequencing of the bone metastases group and the baicalin treatment group, baicalin inhibited the expression of ALPP, DUSP1, CYR61, ALPPL2, SPP1 and TLR4. RT-qPCR was also used to validate the expression levels of these cytokine genes.

Conclusion

Baicalin had a certain inhibitory effect on the SD rat model of bone metastasis cancer. These insights can guide future research on the molecular mechanism of bone cancer pain and provide a theoretical basis for baicalin in the treatment of bone pain caused by breast cancer in the future.

Emerging role of ferroptosis in breast cancer: New dawn for overcoming tumor progression

Breast cancer has become a serious threat to women's health. Cancer progression is mainly derived from resistance to apoptosis induced by procedures or therapies. Therefore, new drugs or models that can overcome apoptosis resistance should be identified. Ferroptosis is a recently identified mode of cell death characterized by excess reactive oxygen species-induced lipid peroxidation. Since ferroptosis is distinct from apoptosis, necrosis and autophagy, its induction successfully eliminates cancer cells that are resistant to other modes of cell death. Therefore, ferroptosis may become a new direction around which to design breast cancer treatment. Unfortunately, the complete appearance of ferroptosis in breast cancer has not yet been fully elucidated. Furthermore, whether ferroptosis inducers can be used in combination with traditional anti- breast cancer drugs is still unknown. Moreover, a summary of ferroptosis in breast cancer progression and therapy is currently not available. In this review, we discuss the roles of ferroptosis-associated modulators glutathione, glutathione peroxidase 4, iron, nuclear factor erythroid-2 related factor-2, superoxide dismutases, lipoxygenase and coenzyme Q in breast cancer. Furthermore, we provide evidence that traditional drugs against breast cancer induce ferroptosis, and that ferroptosis inducers eliminate breast cancer cells. Finally, we put forward prospect of using ferroptosis inducers in breast cancer therapy, and predict possible obstacles and corresponding solutions. This review will deepen our understanding of the relationship between ferroptosis and breast cancer, and provide new insights into breast cancer-related therapeutic strategies.

Coordinated regulation of immune contexture: crosstalk between STAT3 and immune cells during breast cancer progression

Recent insights into the molecular and cellular mechanisms underlying cancer development have revealed the tumor microenvironment (TME) immune cells to functionally affect the development and progression of breast cancer. However, insufficient evidence of TME immune modulators limit the clinical application of immunotherapy for advanced and metastatic breast cancers. Intercellular STAT3 activation of immune cells plays a central role in breast cancer TME immunosuppression and distant metastasis. Accumulating evidence suggests that targeting STAT3 and/or in combination with radiotherapy may enhance anti-cancer immune responses and rescue the systemic immunologic microenvironment in breast cancer. Indeed, apart from its oncogenic role in tumor cells, the functions of STAT3 in TME of breast cancer involve multiple types of immunosuppression and is associated with tumor cell metastasis. In this review, we summarize the available information on the functions of STAT3-related immune cells in TME of breast cancer, as well as the specific upstream and downstream targets. Additionally, we provide insights about the potential immunosuppression mechanisms of each type of evaluated immune cells. Video abstract.

B14 ameliorates bone cancer pain through downregulating spinal interleukin-1β via suppressing neuron JAK2/STAT3 pathway

Curcumin has several pharmacological properties such as anti-inflammatory, antioxidant, and neuroprotective activities. B14 is a curcumin analogue and is considered to be a more potent compound with preserved pharmacodynamic activities. Based on the previous research studies, janus-activated kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway plays a remarkable role in inflammation, chronic pain, and even contributes to the pathogenesis of neuropathic pain. Pro-inflammatory cytokines interleukin-1β is a downstream factor of JAK2/STAT3 signal transition pathway, which participates in neuron injury and inflammation. We hypothesized that this signal transition pathway played an indispensable role in bone cancer pain. We herein established a bone cancer pain model to monitor the variation of JAK2/STAT3 signal transduction pathway and measured the effect of B14. The results in bone cancer pain model showed that (i) the levels of interleukin-1β were elevated, and the ratios of p-JAK2/JAK2 and p-STAT3/STAT3 were increased; (ii) double immunostaining showed that p-JAK2, p-STAT3, and interleukin-1β were colocalized primarily with neurons, rather than with astrocytes or microglial cells; (iii) B14 injection (intraperitoneally) markedly eased bone cancer pain; (iv) Western blotting showed that B14 injection lowered p-JAK2, p-STAT3, and interleukin-1β levels, meanwhile the ratios of p-JAK2/JAK2 and p-STAT3/STAT3 was reduced; (v) immunofluorescence results also confirmed decreased levels of p-JAK2, p-STAT3, and interleukin-1β in B14 treatment group. These findings suggested that B14 injection attenuated bone cancer pain in rats. This intervention inhibited JAK2/STAT3 cascade activation, downregulating interleukin-1β expression in spinal dorsal horn.