SFRP2 Overexpression Induces an Osteoblast-like Phenotype in Prostate Cancer Cells

Clinical challenges in prostate cancer management: Metastatic bone-tropism and the role of circulating tumor cells

Prostate cancer (PCa) metastasis is one of the leading causes of cancer-related mortality in men worldwide, primarily due to its tendency to metastasize, with bones of axial skeleton being the favored target-site. PCa bone-metastasis (PCa-BM) presents significant clinical challenges, especially by the weakening of bone architecture, majorly due to the formation of osteoblastic lesions, leading to severe bone fractures. Another complication is that the disease predominantly affects elderly men. Further exploration is required to understand how the circulating tumor cells (CTCs) adapt to varying microenvironments and other biomechanical stresses encountered during the sequential steps in metastasis, finally resulting in colonization specifically in the bone niche, in PCa-BM. Deciphering how CTCs encounter and adapt to different biochemical, biomechanical and microenvironmental factors may improve the prospects of PCa diagnosis, development of novel therapeutics and prognosis. Moreover, the knowledge developed is expected to have broader implications for cancer research, paving the way for better therapeutic strategies and targeted therapies in the realm of metastatic cancer progression across different types of cancers. Our review begins with analyzing the challenges in PCa diagnosis, treatment and management, and delves into the formation and dynamics of CTCs, highlighting their role in PCa metastasis and bone-tropism. We further explore the pivotal role of individual factors in dictating the predisposition of tumors to metastasize to specific secondary sites, such as the noteworthy tendency of PCa bone-metastasis. Finally, we highlight the unresolved questions and potential avenues for further exploration.

Immunotherapy in the Battle Against Bone Metastases: Mechanisms and Emerging Treatments

Bone metastases are a prevalent complication in advanced cancers, particularly in breast, prostate, and lung cancers, and are associated with severe skeletal-related events (SREs), including fractures, spinal cord compression, and debilitating pain. Conventional bone-targeted treatments like bisphosphonates and RANKL inhibitors (denosumab) reduce osteoclast-mediated bone resorption but do not directly impact tumor progression within the bone. This review focuses on examining the growing potential of immunotherapy in targeting the unique challenges posed by bone metastases. Even though immune checkpoint inhibitors (ICIs) have significantly changed cancer treatment, their impact on bone metastases appears limited because of the bone microenvironment's immunosuppressive traits, which include high levels of transforming growth factor-beta (TGFβ) and the immune-suppressing cells, such as regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). This review underscores the investigation of combined therapeutic approaches that might ease these difficulties, such as the synergy of immune checkpoint inhibitors with agents aimed at bones (denosumab, bisphosphonates), chemotherapy, and radiotherapy, as well as the combination of immune checkpoint inhibitors with different immunotherapeutic methods, including CAR T-cell therapy. This review provides a comprehensive analysis of preclinical studies and clinical trials that show the synergistic potential of these combination approaches, which aim to both enhance immune responses and mitigate bone destruction. By offering an in-depth exploration of how these strategies can be tailored to the bone microenvironment, this review underscores the need for personalized treatment approaches. The findings emphasize the urgent need for further research into overcoming immune evasion in bone metastases, with the goal of improving patient survival and quality of life.

LncRNA CTBP1-AS inhibits TP63-mediated activation of S100A14 during prostate cancer progression

Long noncoding RNAs (lncRNAs) have emerged as important molecules and potential new targets for human cancers. This study investigates the function of lncRNA CTBP1 antisense RNA (CTBP1-AS) in prostate cancer (PCa) and explores the entailed molecular mechanism. Aberrantly expressed genes potentially correlated with PCa progression were probed using integrated bioinformatics analyses. A cohort of 68 patients with PCa was included, and their tumor and para-cancerous tissues were collected. CTBP1-AS was highly expressed in PCa tissues and cells and associated with poor patient prognosis. By contrast, tumor protein p63 (TP63) and S100 calcium binding protein A14 (S100A14) were poorly expressed in the PCa tissues and cells. CTBP1-AS did not affect TP63 expression; however it blocked the TP63-mediated transcriptional activation of S100A14, thereby reducing its expression. CTBP1-AS silencing suppressed proliferation, apoptosis resistance, migration, invasion, and tumorigenicity of PCa cell lines, while its overexpression led to inverse results. The malignant phenotype of cells was further weakened by TP63 overexpression but restored following artificial S100A14 silencing. In conclusion, this study demonstrates that CTBP1-AS plays an oncogenic role in PCa by blocking TP63-mediated transcriptional activation of S100A14. This may provide insight into the management of PCa.

Identification of functional and diverse circulating cancer-associated fibroblasts in metastatic castration-naïve prostate cancer patients

In prostate cancer (PCa), cancer-associated fibroblasts (CAFs) promote tumor progression, drug resistance, and metastasis. Although circulating tumor cells are studied as prognostic and diagnostic markers, little is known about other circulating cells and their association with PCa metastasis. Here, we explored the presence of circulating CAFs (cCAFs) in metastatic castration-naïve prostate cancer (mCNPC) patients. cCAFs were stained with fibroblast activation protein (FAP), epithelial cell adhesion molecule (EpCAM), and receptor-type tyrosine-protein phosphatase C (CD45), then FAP+EpCAM- cCAFs were enumerated and sorted using fluorescence-activated cell sorting. FAP+EpCAM- cCAFs ranged from 60 to 776 (389 mean ± 229 SD) per 2 × 108 mononuclear cells, whereas, in healthy donors, FAP+ EpCAM- cCAFs ranged from 0 to 71 (28 mean ± 22 SD). The mCNPC-derived cCAFs showed positivity for vimentin and intracellular collagen-I. They were viable and functional after sorting, as confirmed by single-cell collagen-I secretion after 48 h of culturing. Two cCAF subpopulations, FAP+CD45- and FAP+CD45+, were identified, both expressing collagen-I and vimentin, but with distinctly different morphologies. Collectively, this study demonstrates the presence of functional and viable circulating CAFs in mCNPC patients, suggesting the role of these cells in prostate cancer.

Whole-transcriptome defines novel glucose metabolic subtypes in colorectal cancer

Colorectal cancer (CRC) is the most prevalent malignancy of the digestive system. Glucose metabolism plays a crucial role in CRC development. However, the heterogeneity of glucose metabolic patterns in CRC is not well characterized. Here, we classified CRC into specific glucose metabolic subtypes and identified the key regulators. 2228 carbohydrate metabolism-related genes were screened out from the GeneCards database, 202 of them were identified as prognosis genes in the TCGA database. Based on the expression patterns of the 202 genes, three metabolic subtypes were obtained by the non-negative matrix factorization clustering method. The C1 subtype had the worst survival outcome and was characterized with higher immune cell infiltration and more activation in extracellular matrix pathways than the other two subtypes. The C2 subtype was the most prevalent in CRC and was characterized by low immune cell infiltration. The C3 subtype had the smallest number of individuals and had a better prognosis, with higher levels of NRF2 and TP53 pathway expression. Secreted frizzled-related protein 2 (SFRP2) and thrombospondin-2 (THBS2) were confirmed as biomarkers for the C1 subtype. Their expression levels were elevated in high glucose condition, while their knockdown inhibited migration and invasion of HCT 116 cells. The analysis of therapeutic potential found that the C1 subtype was more sensitive to immune and PI3K-Akt pathway inhibitors than the other subtypes. To sum up, this study revealed a novel glucose-related CRC subtype, characterized by SFRP2 and THBS2, with poor prognosis but possible therapeutic benefits from immune and targeted therapies.

Transcriptional expression, prognostic value and immune infiltration of SFRP family in colorectal cancer: a study based on comprehensive bioinformatics and in vitro analyses

Background

Secreted frizzled-related protein (SFRP) is a crucial regulator of Wnt signaling, involved in multiple biological processes including cell proliferation and metastasis. Despite the accumulation of evidence that indicated that SFRPs are differentially expressed and play a key role in various malignancies, the function of different SFRPs in colorectal cancer (CRC) remains insufficiently studied.

Methods

Multicenter databases, including GEPIA, cBioPortal, UALCAN, Pathway Commons, STRING, TIMER, CCLE, and LinkedOmics, comprehensively analyzed differential expression, prognostic value, genetic alterations, signaling pathways, immune cell infiltration, and associated genes of the SFRP family in CRC patients. Colony formation, wound healing, and transwell assays were performed to further validate in vitro.

Results

SFRP family members were differentially expressed in CRC, with each member showing varying degrees of genetic alterations. Except for SFRP5, the remaining members show a significant correlation with immune cells. Interestingly, only SFRP2 significantly correlated with CRC prognosis and stage. Additionally, SFRP2 participated in a number of critical biological processes, including metastasis and cell proliferation. Moreover, cell function assays suggested the elimination of SFRP2 inhibits the proliferation, migration, and invasion of HCT116 cells.

Conclusions

The differential expression of SFRP2 is closely associated with the prognosis of CRC patients. In addition, abnormal expression of SFRP2 has a significant impact on the progression of CRC, including proliferation, migration, and invasion. SFRP2 may become a novel prognostic factor for CRC.