BHLHE22 drives the immunosuppressive bone tumor microenvironment and associated bone metastasis in prostate cancer

Mass Spectrometry-Based Proteomics Identifies Serpin B9 as a Key Protein in Promoting Bone Metastases in Lung Cancer

Bone metastasis (BM) is one of the most common complications of advanced cancer. Immunotherapy for bone metastasis of lung cancer (LCBM) is not so promising and the immune mechanisms are still unknown. Here, we utilized a model of BM by injecting cancer cells through caudal artery (CA) to screen out a highly bone metastatic derivative (LLC1-BM3) from a murine lung cancer cell line LLC1. Mass spectrometry-based proteomics was performed in LLC1-parental and LLC1-BM3 cells. Combining with prognostic survival information from patients with lung cancer, we identified serpin B9 (SB9) as a key factor in BM. Molecular characterization showed that SB9 overexpression was associated with poor prognosis and high bone metastatic burden in lung cancer. Moreover, SB9 could increase the ability of lung cancer cells to metastasize to the bone. The mechanistic studies revealed that tumor-derived SB9 promoted BM through an immune cell-dependent way by inactivating granzyme B, manifesting with the decreased infiltration of cytotoxic T cells and increased expression level of exhausted markers. A specific SB9-targeting inhibitor [1,3-benzoxazole-6-carboxylic acid (BTCA)] significantly suppressed LCBM in the CA mouse model. This study reveals that SB9 may serve as a therapeutic target and potential prognostic marker for patients with LCBM.

IMPLICATIONS

SB9 as a therapeutic target for LCBM.

The regulatory process and practical significance of non-coding RNA in the dissemination of prostate cancer to the skeletal system

Prostate cancer is a major contributor to male cancer-related mortality globally. It has a particular affinity for the skeletal system with metastasis to bones seriously impacting prognosis. The identification of prostate cancer biomarkers can significantly enhance diagnosis and patient monitoring. Research has found that cancer and metastases exhibit abnormal expression of numerous non-coding RNA. Some of these RNA facilitate prostate cancer bone metastasis by activating downstream signaling pathways, while others inhibit this process. Elucidating the functional processes of non-coding RNA in prostate cancer bone metastasis will likely lead to innovative treatment strategies for this malignant condition. In this review, the mechanistic role of the various RNA in prostate cancer is examined. Our goal is to provide a new avenue of approach to the diagnosis and treatment of bone metastasis in this cancer.

Beyond boundaries: unraveling innovative approaches to combat bone-metastatic cancers

Evidence demonstrated that bones, liver, and lungs are the most common metastasis sites in some human malignancies, especially in prostate and breast cancers. Bone is the third most frequent target for spreading tumor cells among these organs and tissues. Patients with bone-metastatic cancers face a grim prognosis characterized by short median survival time. Current treatments have proven insufficient, as they can only inhibit metastasis or tumor progression within the bone tissues rather than providing a curative solution. Gaining a more profound comprehension of the interplay between tumor cells and the bone microenvironment (BME) is of utmost importance in tackling this issue. This knowledge will pave the way for developing innovative diagnostic and therapeutic approaches. This review summarizes the mechanisms underlying bone metastasis and discusses the clinical aspects of this pathologic condition. Additionally, it highlights emerging therapeutic interventions aimed at enhancing the quality of life for patients affected by bone-metastatic cancers. By synthesizing current research, this review seeks to shed light on the complexities of bone metastasis and offer insights for future advancements in patient care.

Targeting tumor and bone microenvironment: Novel therapeutic opportunities for castration-resistant prostate cancer patients with bone metastasis

Despite standard hormonal therapy that targets the androgen receptor (AR) attenuates prostate cancer (PCa) effectively in the initial stage, the tumor ultimately converts to castration-resistant prostate cancer (CRPC), and the acquired resistance is still a great challenge for the management of advanced prostate cancer patients. The tumor microenvironment (TME) consists of multiple cellular and noncellular agents is well known as a vital role during the development and progression of CRPC by establishing communication between TME and tumor cells. Additionally, as primary prostate cancer progresses towards metastasis, and CRPC always experiences bone metastasis, the TME is conducive to the spread of tumors to the distant sits, particularly in bone. In addition, the bone microenvironment (BME) is also closely related to the survival, growth and colonization of metastatic tumor cells. The present review summarized the recent studies which mainly focused on the role of TME or BME in the CRPC patients with bone metastasis, and discussed the underlying mechanisms, as well as the potential therapeutic values of targeting TME and BME in the management of metastatic CRPC patients.