Differential effects on lung and bone metastasis of breast cancer by Wnt signalling inhibitor DKK1

CRKL dictates anti-PD-1 resistance by mediating tumor-associated neutrophil infiltration in hepatocellular carcinoma

BACKGROUND & AIMS

The effectiveness of immune checkpoint inhibitor (ICI) therapy for hepatocellular carcinoma (HCC) is limited by treatment resistance. However, the mechanisms underlying immunotherapy resistance remain elusive. We aimed to identify the role of CT10 regulator of kinase-like (CRKL) in resistance to anti-PD-1 therapy in HCC.

METHODS

Gene expression in HCC specimens from 10 patients receiving anti-PD-1 therapy was identified by RNA-sequencing. A total of 404 HCC samples from tissue microarrays were analyzed by immunohistochemistry. Transgenic mice (Alb-Cre/Trp53fl/fl) received hydrodynamic tail vein injections of a CRKL-overexpressing vector. Mass cytometry by time of flight was used to profile the proportion and status of different immune cell lineages in the mouse tumor tissues.

RESULTS

CRKL was identified as a candidate anti-PD-1-resistance gene using a pooled genetic screen. CRKL overexpression nullifies anti-PD-1 treatment efficacy by mobilizing tumor-associated neutrophils (TANs), which block the infiltration and function of CD8+ T cells. PD-L1+ TANs were found to be an essential subset of TANs that were regulated by CRKL expression and display an immunosuppressive phenotype. Mechanistically, CRKL inhibits APC (adenomatous polyposis coli)-mediated proteasomal degradation of β-catenin by competitively decreasing Axin1 binding, and thus promotes VEGFα and CXCL1 expression. Using human HCC samples, we verified the positive correlations of CRKL/β-catenin/VEGFα and CXCL1. Targeting CRKL using CRISPR-Cas9 gene editing (CRKL knockout) or its downstream regulators effectively restored the efficacy of anti-PD-1 therapy in an orthotopic mouse model and a patient-derived organotypic tumor spheroid model.

CONCLUSIONS

Activation of the CRKL/β-catenin/VEGFα and CXCL1 axis is a critical obstacle to successful anti-PD-1 therapy. Therefore, CRKL inhibitors combined with anti-PD-1 could be useful for the treatment of HCC.

IMPACT AND IMPLICATIONS

Here, we found that CRKL was overexpressed in anti-PD-1-resistant hepatocellular carcinoma (HCC) and that CRKL upregulation promotes anti-PD-1 resistance in HCC. We identified that upregulation of the CRKL/β-catenin/VEGFα and CXCL1 axis contributes to anti-PD-1 tolerance by promoting infiltration of tumor-associated neutrophils. These findings support the strategy of bevacizumab-based immune checkpoint inhibitor combination therapy, and CRKL inhibitors combined with anti-PD-1 therapy may be developed for the treatment of HCC.

ETV4 promotes the progression of cholangiocarcinoma by regulating glycolysis via the TGF-β signaling

BACKGROUND

Considerable studies show that ETS variant 4 (ETV4) plays an important roles in multitudinous tumor. This study investigated its function in cholangiocarcinoma (CCA) progression and revealed the underlying mechanisms.

METHODS

The expression of ETV4 in CCA was evaluated using TCGA database and the single-cell analysis based on GSE189903 dataset. ETV4 expression in CCA human specimens was detected by reverse transcription-quantitative PCR, immunohistochemistry, and western blot. Cell Counting Kit-8, EdU, colony formation, wound healing, and Transwell assays were used to analyze the effects of ETV4. Extracellular acidification rate, oxygen consumption rate, glucose uptake, and lactate production were used to measure glycolysis in CAA cells. Western blot was performed to explore glycolysis-related proteins. Tumor growth was evaluated in mice xenograft tumors.

RESULTS

ETV4 was up-regulated in CCA epithelial cells. The high-expression of ETV4 was associated with poor prognosis of patients with CCA. ETV4 overexpression enhanced the proliferation, migration, invasion, and glycolysis of CCA cells; ETV4 silencing led to the contrary effects. Mechanistically, ETV4 activates TGF-β/Smad2/3 signaling pathway. In mice xenograft mode, ETV4 silencing inhibits the tumor growth, the expression of glycolysis-related proteins and TGF-β/Smad2/3 pathway proteins.

CONCLUSIONS

ETV4 functions as an essential factor in the roles of TGF-β1 in CCA cells, and may be a promising target for TGF-β1-mediated CCA progression.

Liver tropism of ER mutant breast cancer is characterized by unique molecular changes and immune infiltration

PURPOSE

Hotspot estrogen receptor alpha (ER/ESR1) mutations are recognized as the driver for both endocrine resistance and metastasis in advanced ER-positive (ER+) breast cancer, but their contributions to metastatic organ tropism remain insufficiently understood. In this study, we aim to comprehensively profile the organotropic metastatic pattern for ESR1 mutant breast cancer.

METHODS

The organ-specific metastatic pattern of ESR1 mutant breast cancer was delineated using multi-omics data from multiple publicly available cohorts of ER+ metastatic breast cancer patients. Gene mutation/copy number variation (CNV) and differential gene expression analyses were performed to identify the genomic and transcriptomic alterations uniquely associated with ESR1 mutant liver metastasis. Upstream regulator, downstream pathway, and immune infiltration analysis were conducted for subsequent mechanistic investigations.

RESULTS

ESR1 mutation-driven liver tropism was revealed by significant differences, encompassing a higher prevalence of liver metastasis in patients with ESR1 mutant breast cancer and an enrichment of mutations in liver metastatic samples. The significant enrichment of AGO2 copy number amplifications (CNAs) and multiple gene expression changes were revealed uniquely in ESR1 mutant liver metastasis. We also unveiled alterations in downstream signaling pathways and immune infiltration, particularly an enrichment of neutrophils, suggesting potential therapeutic vulnerabilities.

CONCLUSION

Our data provide a comprehensive characterization of the behaviors and mechanisms of ESR1 mutant liver metastasis, paving the way for the development of personalized therapy to target liver metastasis for patients with ESR1 mutant breast cancer.

Correlation of serum DKK1 level with skeletal phenotype in children with osteogenesis imperfecta

PURPOSE

We aim to detect serum DKK1 level of pediatric patients with OI and to analyze its relationship with the genotype and phenotype of OI patients.

METHODS

A cohort of pediatric OI patients and age-matched healthy children were enrolled. Serum levels of DKK1 and bone turnover biomarkers were measured by enzyme-linked immunosorbent assay. Bone mineral density (BMD) was measured by Dual-energy X-ray absorptiometry. Pathogenic mutations of OI were detected by next-generation sequencing and confirmed by Sanger sequencing.

RESULTS

A total of 62 OI children with mean age of 9.50 (4.86, 12.00) years and 29 healthy children were included in this study. The serum DKK1 concentration in OI children was significantly higher than that in healthy children [5.20 (4.54, 6.32) and 4.08 (3.59, 4.92) ng/mL, P < 0.001]. The serum DKK1 concentration in OI children was negatively correlated with height (r = - 0.282), height Z score (r = - 0.292), ALP concentration (r = - 0.304), lumbar BMD (r = - 0.276), BMD Z score of the lumbar spine and femoral neck (r = - 0.32; r = - 0.27) (all P < 0.05). No significant difference in serum DKK1 concentration was found between OI patients with and without vertebral compression fractures. In patients with spinal deformity (22/62), serum DKK1 concentration was positively correlated with SDI (r = 0.480, P < 0.05). No significant correlation was observed between serum DKK1 concentration and the annual incidence of peripheral fractures, genotype and types of collagen changes in OI children.

CONCLUSION

The serum DKK1 level was not only significantly elevated in OI children, but also closely correlated to their skeletal phenotype, suggesting that DKK1 may become a new biomarker and a potential therapeutic target of OI.

Dickkopf-1 (DKK1) drives growth and metastases in castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is associated with a poor prognosis and remains an incurable fatal disease. Therefore, the identification of molecular markers involved in cancer progression is urgently needed to develop more-effective therapies. The present study investigated the role of the Wnt signaling modulator Dickkopf-1 (DKK1) in the growth and metastatic progression of mCRPC. DKK1 silencing through siRNA and deletion via CRISPR/Cas9 editing were performed in two different metastatic castration-resistant prostate cancer cell lines (PC3 and DU145). A xenograft tumor model was used to assess tumor growth and metastases. In in vitro experiments, both DKK1 silencing and deletion reduced cell growth and migration of both cell lines. DKK1 knockout clones (DKK1-KO) exhibited cell cycle arrest, tubulin reorganization, and modulation of tumor metastasis-associated genes. Furthermore, in DKK1-KO cells, E-cadherin re-expression and its membrane co-localization with β-catenin were observed, contributing to reduced migration; Cadherin-11, known to increase during epithelial-mesenchymal transition, was down-regulated in DKK1-KO cells. In the xenograft mouse model, DKK1 deletion not only reduced tumor growth but also inhibited the formation of lung metastases. In conclusion, our findings support the key role of DKK1 in the growth and metastatic dissemination of mCRPC, both in vitro and in vivo.

Intersecting Paths: Unraveling the Complex Journey of Cancer to Bone Metastasis

The phenomenon of bone metastases presents a significant challenge within the context of advanced cancer treatments, particularly pertaining to breast, prostate, and lung cancers. These metastatic occurrences stem from the dissemination of cancerous cells into the bone, thereby interrupting the equilibrium between osteoblasts and osteoclasts. Such disruption results in skeletal complications, adversely affecting patient morbidity and quality of life. This review discusses the intricate interplay between cancer cells and the bone microenvironment, positing the bone not merely as a passive recipient of metastatic cells but as an active contributor to cancer progression through its distinctive biochemical and cellular makeup. A thorough examination of bone structure and the dynamics of bone remodeling is undertaken, elucidating how metastatic cancer cells exploit these processes. This review explores the genetic and molecular pathways that underpin the onset and development of bone metastases. Particular emphasis is placed on the roles of cytokines and growth factors in facilitating osteoclastogenesis and influencing osteoblast activity. Additionally, this paper offers a meticulous critique of current diagnostic methodologies, ranging from conventional radiography to advanced molecular imaging techniques, and discusses the implications of a nuanced understanding of bone metastasis biology for therapeutic intervention. This includes the development of targeted therapies and strategies for managing bone pain and other skeletal-related events. Moreover, this review underscores the imperative of ongoing research efforts aimed at identifying novel therapeutic targets and refining management approaches for bone metastases. It advocates for a multidisciplinary strategy that integrates advancements in medical oncology and radiology with insights derived from molecular biology and genetics, to enhance prognostic outcomes and the quality of life for patients afflicted by this debilitating condition. In summary, bone metastases constitute a complex issue that demands a comprehensive and informed approach to treatment. This article contributes to the ongoing discourse by consolidating existing knowledge and identifying avenues for future investigation, with the overarching objective of ameliorating patient care in the domain of oncology.

Wnt signaling: Modulating tumor-associated macrophages and related immunotherapeutic insights

Wnt signaling pathways are highly conserved cascades that mediate multiple biological processes through canonical or noncanonical pathways, from embryonic development to tissue maintenance, but they also contribute to the pathogenesis of numerous cancers. Recent studies have revealed that Wnt signaling pathways critically control the interplay between cancer cells and tumor-associated macrophages (TAMs) in the tumor microenvironment (TME) and potentially impact the efficacy of cancer immunotherapy. In this review, we summarize the evidence that Wnt signaling pathways boost the maturation and infiltration of macrophages for immune surveillance in the steady state but also polarize TAMs toward immunosuppressive M2-like phenotypes for immune escape in the TME. Both cancer cells and TAMs utilize Wnt signaling to transmit signals, and this interaction is crucial for the carcinogenesis and progression of common solid cancers, such as colorectal, gastric, hepatocellular, breast, thyroid, prostate, kidney, and lung cancers; osteosarcoma; and glioma. Specifically, compared with those in solid cancers, Wnt signaling pathways play a distinct role in the pathogenesis of leukemia. Efforts to develop Wnt-based drugs for cancer treatment are still ongoing, and some indeed enhance the anticancer immune response. We believe that the combination of Wnt signaling-based therapy with conventional or immune therapies is a promising therapeutic approach and can facilitate personalized treatment for most cancers.

Cancer-associated fibroblast-derived Dickkopf-1 suppresses NK cell cytotoxicity in breast cancer

Breast cancer is poorly immunogenic, hence able to evade T cell recognition and respond poorly to immune checkpoint blockade. Breast cancer cells can also evade NK cell-mediated immune surveillance, but the mechanism remains enigmatic. Dickkopf-1 (DKK1) is a Wnt/b-catenin inhibitor, whose levels are increased in breast cancer patients and correlate with reduced overall survival. DKK1 is expressed by cancer-associated fibroblasts (CAFs) in orthotopic breast tumors and patient samples, and at higher levels by bone cells. While bone-derived DKK1 contributes to the systemic elevation of DKK1 in tumor-bearing mice, CAFs represent the primary source of DKK1 at the tumor site. Systemic or bone-specific DKK1 targeting reduces primary tumor growth. Intriguingly, specific deletion of CAF-derived DKK1 also limits breast cancer progression, regardless of its elevated levels in circulation and in the bone. DKK1 does not support tumor proliferation directly but rather suppresses the activation and tumoricidal activity of NK cells. Importantly, increased DKK1 levels and reduced number of cytotoxic NK cells are detected in breast cancer patients with progressive bone metastases compared to those with stable disease. Our findings indicate that DKK1 creates a tumor-supporting environment through the suppression of NK cells in breast cancer.

The oncolytic bacteria-mediated delivery system of CCDC25 nucleic acid drug inhibits neutrophil extracellular traps induced tumor metastasis

BACKGROUND

Neutrophil extracellular traps (NETs), antibacterial weapons of neutrophils (NEs), have been found to play a crucial role in cancer metastasis in recent years. More and more cancer research is focusing on anti-NETs. However, almost all anti-NETs treatments have limitations such as large side effects and limited efficacy. Therefore, exploring new anti-NETs therapeutic strategies is a long-term goal.

RESULTS

The transmembrane protein coiled-coil domain containing 25 (CCDC25) on tumor cell membranes can bind NETs-DNA with high specificity and affinity, enabling tumor cells to sense NETs and thus promote distant metastasis. We transformed shCCDC25 into VNP20009 (VNP), an oncolytic bacterium, to generate VNP-shCCDC25 and performed preclinical evaluation of the inhibitory effect of shCCDC25 on cancer metastasis in B16F10 lung metastasis and 4T1 orthotopic lung metastasis models. VNP-shCCDC25 effectively blocked the downstream prometastatic signaling pathway of CCDC25 at tumor sites and reduced the formation of NETs while recruiting more neutrophils and macrophages to the tumor core, ultimately leading to excellent metastasis inhibition in the two lung metastasis models.

CONCLUSION

This study is a pioneer in focusing on the effect of anti-NET treatment on CCDC25. shCCDC25 is effectively delivered to tumor sites via the help of oncolytic bacteria and has broad application in the inhibition of cancer metastasis via anti-NETs.

LncRNA Malat1 suppresses pyroptosis and T cell-mediated killing of incipient metastatic cells

The contribution of antitumor immunity to metastatic dormancy is poorly understood. Here we show that the long noncoding RNA Malat1 is required for tumor initiation and metastatic reactivation in mouse models of breast cancer and other tumor types. Malat1 localizes to nuclear speckles to couple transcription, splicing and mRNA maturation. In metastatic cells, Malat1 induces WNT ligands, autocrine loops to promote self-renewal and the expression of Serpin protease inhibitors. Through inhibition of caspase-1 and cathepsin G, SERPINB6B prevents gasdermin D-mediated induction of pyroptosis. In this way, SERPINB6B suppresses immunogenic cell death and confers evasion of T cell-mediated tumor lysis of incipient metastatic cells. On-target inhibition of Malat1 using therapeutic antisense nucleotides suppresses metastasis in a SERPINB6B-dependent manner. These results suggest that Malat1-induced expression of SERPINB6B can titrate pyroptosis and immune recognition at metastatic sites. Thus, Malat1 is at the nexus of tumor initiation, reactivation and immune evasion and represents a tractable and clinically relevant drug target.

The Role of Breast Cancer Cells in Bone Metastasis: Suitable Seeds for Nourishing Soil

PURPOSE OF REVIEW

The purpose of this review was to describe the characteristics of breast cancer cells prone to developing bone metastasis and determine how they are regulated by the bone microenvironment.

RECENT FINDINGS

The bone is a site of frequent breast cancer metastasis. Bone metastasis accounts for 70% of advanced breast cancer cases and remains incurable. It can lead to skeletal-related events, such as bone fracture and pain, and seriously affect the quality of life of patients. Breast cancer cells escape from the primary lesion and spread to the bone marrow in the early stages. They can then enter the dormant state and restore tumourigenicity after several years to develop overt metastasis. In the last few years, an increasing number of studies have reported on the factors promoting bone metastasis of breast cancer cells, both at the primary and metastatic sites. Identifying factors associated with bone metastasis aids in the early recognition of bone metastasis tendency. How to target these factors and minimize the side effects on the bone remains to be further explored.

Fibroblasts inhibit osteogenesis by regulating nuclear-cytoplasmic shuttling of YAP in mesenchymal stem cells and secreting DKK1

BACKGROUND

Fibrous scars frequently form at the sites of bone nonunion when attempts to repair bone fractures have failed. However, the detailed mechanism by which fibroblasts, which are the main components of fibrous scars, impede osteogenesis remains largely unknown.

RESULTS

In this study, we found that fibroblasts compete with osteogenesis in both human bone nonunion tissues and BMP2-induced ectopic osteogenesis in a mouse model. Fibroblasts could inhibit the osteoblastic differentiation of mesenchymal stem cells (MSCs) via direct and indirect cell competition. During this process, fibroblasts modulated the nuclear-cytoplasmic shuttling of YAP in MSCs. Knocking down YAP could inhibit osteoblast differentiation of MSCs, while overexpression of nuclear-localized YAP-5SA could reverse the inhibition of osteoblast differentiation of MSCs caused by fibroblasts. Furthermore, fibroblasts secreted DKK1, which further inhibited the formation of calcium nodules during the late stage of osteogenesis but did not affect the early stage of osteogenesis. Thus, fibroblasts could inhibit osteogenesis by regulating YAP localization in MSCs and secreting DKK1.

CONCLUSIONS

Our research revealed that fibroblasts could modulate the nuclear-cytoplasmic shuttling of YAP in MSCs, thereby inhibiting their osteoblast differentiation. Fibroblasts could also secrete DKK1, which inhibited calcium nodule formation at the late stage of osteogenesis.

CircMMP2(6,7) Cooperates with β-Catenin and PRMT5 to Disrupt Bone Homeostasis and Promote Breast Cancer Bone Metastasis

The bone is the most common site of distant metastasis of breast cancer, which leads to serious skeletal complications and mortality. Understanding the mechanisms underlying breast cancer bone metastasis would provide potential strategies for the prevention and treatment of breast cancer bone metastasis. In this study, we identified a circular RNA that we named circMMP2(6,7) that was significantly upregulated in bone metastatic breast cancer tissues and correlated with breast cancer-bone metastasis. Upregulation of circMMP2(6,7) dramatically enhanced the metastatic capability of breast cancer cells to the bone via inducing bone metastatic niche formation by disrupting bone homeostasis. Mechanistically, circMMP2(6,7) specifically bound to the promoters of bone-remodeling factors calcium-binding protein S100A4 and carbohydrate-binding protein LGALS3 and formed a complex with β-catenin and arginine methyltransferase PRMT5, eliciting histone H3R2me1/H3R2me2s-induced transcriptional activation. Treatment with GSK591, a selective PRMT5 inhibitor, effectively inhibited circMMP2(6,7)/β-catenin/PRMT5 complex-induced breast cancer bone metastasis. These findings reveal a role for circMMP2(6,7) in bone homeostasis disruption and shed light on the mechanisms driving breast cancer bone metastasis.

SIGNIFICANCE

Upregulation of bone-remodeling factors S100A4 and LGALS3 mediated by a circMMP2(6,7)/β-catenin/PRMT5 complex generates a niche that supports breast cancer bone metastasis, identifying PRMT5 as a promising target for treating metastasis.

LASS2 enhances chemosensitivity to cisplatin by inhibiting PP2A-mediated β-catenin dephosphorylation in a subset of stem-like bladder cancer cells

BACKGROUND

The benefits of first-line, cisplatin-based chemotherapy for muscle-invasive bladder cancer are limited due to intrinsic or acquired resistance to cisplatin. Increasing evidence has revealed the implication of cancer stem cells in the development of chemoresistance. However, the underlying molecular mechanisms remain to be elucidated. This study investigates the role of LASS2, a ceramide synthase, in regulating Wnt/β-catenin signaling in a subset of stem-like bladder cancer cells and explores strategies to sensitize bladder cancer to cisplatin treatment.

METHODS

Data from cohorts of our center and published datasets were used to evaluate the clinical characteristics of LASS2. Flow cytometry was used to sort and analyze bladder cancer stem cells (BCSCs). Tumor sphere formation, soft agar colony formation assay, EdU assay, apoptosis analysis, cell viability, and cisplatin sensitivity assay were used to investigate the functional roles of LASS2. Immunofluorescence, immunoblotting, coimmunoprecipitation, LC-MS, PCR array, luciferase reporter assays, pathway reporter array, chromatin immunoprecipitation, gain-of-function, and loss-of-function approaches were used to investigate the underlying mechanisms. Cell- and patient-derived xenograft models were used to investigate the effect of LASS2 overexpression and a combination of XAV939 on cisplatin sensitization and tumor growth.

RESULTS

Patients with low expression of LASS2 have a poorer response to cisplatin-based chemotherapy. Loss of LASS2 confers a stem-like phenotype and contributes to cisplatin resistance. Overexpression of LASS2 results in inhibition of self-renewal ability of BCSCs and increased their sensitivity to cisplatin. Mechanistically, LASS2 inhibits PP2A activity and dissociates PP2A from β-catenin, preventing the dephosphorylation of β-catenin and leading to the accumulation of cytosolic phospho-β-catenin, which decreases the transcription of the downstream genes ABCC2 and CD44 in BCSCs. Overexpression of LASS2 combined with a tankyrase inhibitor (XAV939) synergistically inhibits tumor growth and restores cisplatin sensitivity.

CONCLUSIONS

Targeting the LASS2 and β-catenin pathways may be an effective strategy to overcome cisplatin resistance and inhibit tumor growth in bladder cancer patients.

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

Predictive and prognostic biomarkers of bone metastasis in breast cancer: current status and future directions

The most common site of metastasis in breast cancer is the bone, where the balance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation is disrupted. This imbalance causes osteolytic bone metastasis in breast cancer, which leads to bone pain, pathological fractures, spinal cord compression, and other skeletal-related events (SREs). These complications reduce patients' quality of life significantly and have a profound impact on prognosis. In this review, we begin by providing a brief overview of the epidemiology of bone metastasis in breast cancer, including current diagnostic tools, treatment approaches, and existing challenges. Then, we will introduce the pathophysiology of breast cancer bone metastasis (BCBM) and the animal models involved in the study of BCBM. We then come to the focus of this paper: a discussion of several biomarkers that have the potential to provide predictive and prognostic value in the context of BCBM-some of which may be particularly compatible with more comprehensive liquid biopsies. Beyond that, we briefly explore the potential of new technologies such as single-cell sequencing and organoid models, which will improve our understanding of tumor heterogeneity and aid in the development of improved biomarkers. The emerging biomarkers discussed hold promise for future clinical application, aiding in the prevention of BCBM, improving the prognosis of patients, and guiding the implementation of personalized medicine.

Application of advanced biomaterials in photothermal therapy for malignant bone tumors

Malignant bone tumors are characterized by severe disability rate, mortality rate, and heavy recurrence rate owing to the complex pathogenesis and insidious disease progression, which seriously affect the terminal quality of patients' lives. Photothermal therapy (PTT) has emerged as an attractive adjunctive treatment offering prominent hyperthermal therapeutic effects to enhance the effectiveness of surgical treatment and avoid recurrence. Simultaneously, various advanced biomaterials with photothermal capacity are currently created to address malignant bone tumors, performing distinctive biological functions, including nanomaterials, bioceramics (BC), polymers, and hydrogels et al. Furthermore, PTT-related combination therapeutic strategies can provide more significant curative benefits by reducing drug toxicity, improving tumor-killing efficiency, stimulating anti-cancer immunity, and improving immune sensitivity relative to monotherapy, even in complex tumor microenvironments (TME). This review summarizes the current advanced biomaterials applicable in PTT and relevant combination therapies on malignant bone tumors for the first time. The multiple choices of advanced biomaterials, treatment methods, and new prospects for future research in treating malignant bone tumors with PTT are generalized to provide guidance. Malignant bone tumors seriously affect the terminal quality of patients' lives. Photothermal therapy (PTT) has emerged as an attractive adjunctive treatment enhancing the effectiveness of surgical treatment and avoiding recurrence. In this review, advanced biomaterials applicable in the PTT of malignant bone tumors and their distinctive biological functions are comprehensively summarized for the first time. Simultaneously, multiple PTT-related combination therapeutic strategies are classified to optimize practical clinical issues, contributing to the selection of biomaterials, therapeutic alternatives, and research perspectives for the adjuvant treatment of malignant bone tumors with PTT in the future.

Mechanisms of Organ-Specific Metastasis of Breast Cancer

Cancer metastasis, or the development of secondary tumors in distant tissues, accounts for the vast majority of fatalities in patients with breast cancer. Breast cancer cells show a striking proclivity to metastasize to distinct organs, specifically the lung, liver, bone, and brain, where they face unique environmental pressures and a wide variety of tissue-resident cells that together create a strong barrier for tumor survival and growth. As a consequence, successful metastatic colonization is critically dependent on reciprocal cross talk between cancer cells and host cells within the target organ, a relationship that shapes the formation of a tumor-supportive microenvironment. Here, we discuss the mechanisms governing organ-specific metastasis in breast cancer, focusing on the intricate interactions between metastatic cells and specific niche cells within a secondary organ, and the remarkable adaptations of both compartments that cooperatively support cancer growth. More broadly, we aim to provide a framework for the microenvironmental prerequisites within each distinct metastatic site for successful breast cancer metastatic seeding and outgrowth.

Organ-Specificity of Breast Cancer Metastasis

Breast cancer (BC) remains one of the most common malignancies among women worldwide. Breast cancer shows metastatic heterogeneity with priority to different organs, which leads to differences in prognosis and response to therapy among patients. The main targets for metastasis in BC are the bone, lung, liver and brain. The molecular mechanism of BC organ-specificity is still under investigation. In recent years, the appearance of new genomic approaches has led to unprecedented changes in the understanding of breast cancer metastasis organ-specificity and has provided a new platform for the development of more effective therapeutic agents. This review summarises recent data on molecular organ-specific markers of metastasis as the basis of a possible therapeutic approach in order to improve the diagnosis and prognosis of patients with metastatically heterogeneous breast cancer.

The evolution and heterogeneity of neutrophils in cancers: origins, subsets, functions, orchestrations and clinical applications

Neutrophils, the most prevalent innate immune cells in humans, have garnered significant attention in recent years due to their involvement in cancer progression. This comprehensive review aimed to elucidate the important roles and underlying mechanisms of neutrophils in cancer from the perspective of their whole life cycle, tracking them from development in the bone marrow to circulation and finally to the tumor microenvironment (TME). Based on an understanding of their heterogeneity, we described the relationship between abnormal neutrophils and clinical manifestations in cancer. Specifically, we explored the function, origin, and polarization of neutrophils within the TME. Furthermore, we also undertook an extensive analysis of the intricate relationship between neutrophils and clinical management, including neutrophil-based clinical treatment strategies. In conclusion, we firmly assert that directing future research endeavors towards comprehending the remarkable heterogeneity exhibited by neutrophils is of paramount importance.

Wnt/β-Catenin Promotes the Osteoblastic Potential of BMP9 Through Down-Regulating Cyp26b1 in Mesenchymal Stem Cells

BACKGROUND

All-trans retinoic acid (ATRA) promotes the osteogenic differentiation induced by bone morphogenetic protein 9 (BMP9), but the intrinsic relationship between BMP9 and ATRA keeps unknown. Herein, we investigated the effect of Cyp26b1, a critical enzyme of ATRA degradation, on the BMP9-induced osteogenic differentiation in mesenchymal stem cells (MSCs), and unveiled possible mechanism through which BMP9 regulates the expression of Cyp26b1.

METHODS

ATRA content was detected with ELISA and HPLC-MS/MS. PCR, Western blot, and histochemical staining were used to assay the osteogenic markers. Fetal limbs culture, cranial defect repair model, and micro-computed tomographic were used to evaluate the quality of bone formation. IP and ChIP assay were used to explore possible mechanism.

RESULTS

We found that the protein level of Cyp26b1 was increased with age, whereas the ATRA content decreased. The osteogenic markers induced by BMP9 were increased by inhibiting or silencing Cyp26b1 but reduced by exogenous Cyp26b1. The BMP9-induced bone formation was enhanced by inhibiting Cyp26b1. The cranial defect repair was promoted by BMP9, which was strengthened by silencing Cyp26b1 and reduced by exogenous Cyp26b1. Mechanically, Cyp26b1 was reduced by BMP9, which was enhanced by activating Wnt/β-catenin, and reduced by inhibiting this pathway. β-catenin interacts with Smad1/5/9, and both were recruited at the promoter of Cyp26b1.

CONCLUSIONS

Our findings suggested the BMP9-induced osteoblastic differentiation was mediated by activating retinoic acid signalling, viadown-regulating Cyp26b1. Meanwhile, Cyp26b1 may be a novel potential therapeutic target for the treatment of bone-related diseases or accelerating bone-tissue engineering.

Machine learning-based immune prognostic model and ceRNA network construction for lung adenocarcinoma

PURPOSE

Lung adenocarcinoma (LUAD) is a malignant tumor with a high lethality rate. Immunotherapy has become a breakthrough in cancer treatment and improves patient survival and prognosis. Therefore, it is necessary to find new immune-related markers. However, the current research on immune-related markers in LUAD is not sufficient. Therefore, there is a need to find new immune-related biomarkers to help treat LUAD patients.

METHODS

In this study, a bioinformatics approach combined with a machine learning approach screened reliable immune-related markers to construct a prognostic model to predict the overall survival (OS) of LUAD patients, thus promoting the clinical application of immunotherapy in LUAD. The experimental data were obtained from The Cancer Genome Atlas (TCGA) database, including 535 LUAD and 59 healthy control samples. Firstly, the Hub gene was screened using a bioinformatics approach combined with the Support Vector Machine Recursive Feature Elimination algorithm; then, a multifactorial Cox regression analysis by constructing an immune prognostic model for LUAD and a nomogram to predict the OS rate of LUAD patients. Finally, the regulatory mechanism of Hub genes in LUAD was analyzed by ceRNA.

RESULTS

Five genes, ADM2, CDH17, DKK1, PTX3, and AC145343.1, were screened as potential immune-related genes in LUAD. Among them, ADM2 and AC145343.1 had a good prognosis in LUAD patients (HR < 1) and were novel markers. The remaining three genes screened were associated with poor prognosis in LUAD patients (HR > 1). In addition, the experimental results showed that patients in the low-risk group had better OS rates than those in the high-risk group (P < 0.001).

CONCLUSION

In this paper, we propose an immune prognostic model to predict OS rate in LUAD patients and show the correlation between five immune genes and the level of immune-related cell infiltration. It provides new markers and additional ideas for immunotherapy in patients with LUAD.

SCUBE2 mediates bone metastasis of luminal breast cancer by modulating immune-suppressive osteoblastic niches

Estrogen receptor (ER)-positive luminal breast cancer is a subtype with generally lower risk of metastasis to most distant organs. However, bone recurrence occurs preferentially in luminal breast cancer. The mechanisms of this subtype-specific organotropism remain elusive. Here we show that an ER-regulated secretory protein SCUBE2 contributes to bone tropism of luminal breast cancer. Single-cell RNA sequencing analysis reveals osteoblastic enrichment by SCUBE2 in early bone-metastatic niches. SCUBE2 facilitates release of tumor membrane-anchored SHH to activate Hedgehog signaling in mesenchymal stem cells, thus promoting osteoblast differentiation. Osteoblasts deposit collagens to suppress NK cells via the inhibitory LAIR1 signaling and promote tumor colonization. SCUBE2 expression and secretion are associated with osteoblast differentiation and bone metastasis in human tumors. Targeting Hedgehog signaling with Sonidegib and targeting SCUBE2 with a neutralizing antibody both effectively suppress bone metastasis in multiple metastasis models. Overall, our findings provide a mechanistic explanation for bone preference in luminal breast cancer metastasis and new approaches for metastasis treatment.

Endothelium and Subendothelial Matrix Mechanics Modulate Cancer Cell Transendothelial Migration

Cancer cell extravasation, a key step in the metastatic cascade, involves cancer cell arrest on the endothelium, transendothelial migration (TEM), followed by the invasion into the subendothelial extracellular matrix (ECM) of distant tissues. While cancer research has mostly focused on the biomechanical interactions between tumor cells (TCs) and ECM, particularly at the primary tumor site, very little is known about the mechanical properties of endothelial cells and the subendothelial ECM and how they contribute to the extravasation process. Here, an integrated experimental and theoretical framework is developed to investigate the mechanical crosstalk between TCs, endothelium and subendothelial ECM during in vitro cancer cell extravasation. It is found that cancer cell actin-rich protrusions generate complex push-pull forces to initiate and drive TEM, while transmigration success also relies on the forces generated by the endothelium. Consequently, mechanical properties of the subendothelial ECM and endothelial actomyosin contractility that mediate the endothelial forces also impact the endothelium's resistance to cancer cell transmigration. These results indicate that mechanical features of distant tissues, including force interactions between the endothelium and the subendothelial ECM, are key determinants of metastatic organotropism.

Osteocytes: New Kids on the Block for Cancer in Bone Therapy

The tumor microenvironment plays a central role in the onset and progression of cancer in the bone. Cancer cells, either from tumors originating in the bone or from metastatic cancer cells from other body systems, are located in specialized niches where they interact with different cells of the bone marrow. These interactions transform the bone into an ideal niche for cancer cell migration, proliferation, and survival and cause an imbalance in bone homeostasis that severely affects the integrity of the skeleton. During the last decade, preclinical studies have identified new cellular mechanisms responsible for the dependency between cancer cells and bone cells. In this review, we focus on osteocytes, long-lived cells residing in the mineral matrix that have recently been identified as key players in the spread of cancer in bone. We highlight the most recent discoveries on how osteocytes support tumor growth and promote bone disease. Additionally, we discuss how the reciprocal crosstalk between osteocytes and cancer cells provides the opportunity to develop new therapeutic strategies to treat cancer in the bone.

A novel microRNA-182/Interleukin-8 regulatory axis controls osteolytic bone metastasis of lung cancer

Bone metastasis is one of the main complications of lung cancer and most important factors that lead to poor life quality and low survival rate in lung cancer patients. However, the regulatory mechanisms underlying lung cancer bone metastasis are still poor understood. Here, we report that microRNA-182 (miR-182) plays a critical role in regulating osteoclastic metastasis of lung cancer cells. We found that miR-182 was significantly upregulated in both bone-metastatic human non-small cell lung cancer (NSCLC) cell line and tumor specimens. We further demonstrated that miR-182 markedly enhanced the ability of NSCLC cells for osteolytic bone metastasis in nude mice. Mechanistically, miR-182 promotes NSCLC cells to secrete Interleukin-8 (IL-8) and in turn facilitates osteoclastogenesis via activating STAT3 signaling in osteoclast progenitor cells. Importantly, systemically delivered IL-8 neutralizing antibody inhibits NSCLC bone metastasis in nude mice. Collectively, our findings identify the miR-182/IL-8/STAT3 axis as a key regulatory pathway in controlling lung cancer cell-induced osteolytic bone metastasis and suggest a promising therapeutic strategy that targets this regulatory axis to interrupt lung cancer bone metastasis.

Identification of a luminescent platinum(II) complex with BODIPY derivative as novel photodynamic therapy agent for triple negative breast cancer cells

Triple-negative breast cancer (TNBC) is one of the most malignant breast tumors for its poor prognosis and high tumor recurrence. It is urgent to develop new strategy or effective agents to overcome resistance and improve therapeutic effectiveness. Boron-dipyrromethene (BODIPY) based photosensitizers possess exciting photophysical features suitable for theranostic applications, namely, photodynamic therapy (PDT). We have designed a luminescent monofunctional platinum(II) complex with BODIPY derivative, namely I₂BC-Pt, as novel high PDT agent against triple negative breast cancer (TNBC). The di-iodinated BODIPY complex I₂BC-Pt showed excellent PDT effect against TNBC cells in green light (520 nm) giving IC₅₀ values of 0.11-0.13 μM in MDA-MB-231 and MDA-MB-468 cells. I₂BC-Pt predominately aggregated in the mitochondria of MDA-MB-231 cells and emitted green fluorescence. Besides, the anticancer mechanism studies demonstrated that I₂BC-Pt could help DNA repair through attenuating RAD51, FoxM1 and BRCA1/2, and induce p53-mediated apoptosis of TNBC cells. Taken together, I₂BC-Pt could be potentially developed as a BODIPY-based photosensitizers for TNBC therapy.

Characterization of tumor microenvironment and programmed death-related genes to identify molecular subtypes and drug resistance in pancreatic cancer

Background: Immunotherapy has been a key option for the treatment of many types of cancer. A positive response to immunotherapy is heavily dependent on tumor microenvironment (TME) interaction. However, in pancreatic adenocarcinoma (PAAD), the association between TME mode of action and immune cell infiltration and immunotherapy, clinical outcome remained unknown.

Methods: We systematically evaluated 29 TME genes in PAAD signature. Molecular subtypes of distinct TME signatures in PAAD were characterized by consensus clustering. After this, we comprehensively analyzed their clinical features, prognosis, and immunotherapy/chemotherapy response using correlation analysis, Kaplan-Meier curves analysis, ssGSEA analysis. 12 programmed cell death (PCD) patterns were acquired from previous study. Differentially expressed genes (DEGs) were acquired based on differential analysis. Key genes affecting overall survival (OS) of PAAD were screened by COX regression analysis and used to develop a RiskScore evaluation model. Finally, we assessed the value of RiskScore in predicting prognosis and treatment response in PAAD.

Results: We identified 3 patterns of TME-associated molecular subtypes (C1, C2, C3), and observed that clinicopathological characteristics, prognosis, pathway features and immune features, immunotherapy/chemosensitivity of patients were correlated with the TME related subtypes. C1 subtype was more sensitive to the four chemotherapeutic drugs. PCD patterns were more likely to occur at C2 or C3. At the same time, we also detected 6 key genes that could affect the prognosis of PAAD, and 5 genes expressions were closely associated to methylation level. Low-risk patients with high immunocompetence had favorable prognostic results and high immunotherapy benefit. Patients in the high-risk group were more sensitive to chemotherapeutic drugs. RiskScore related to TME was an independent prognostic factor for PAAD.

Conclusion: Collectively, we identified a prognostic signature of TME in PAAD patients, which could help elucidate the specific mechanism of action of TME in tumors and help to explore more effective immunotherapy strategies.

The tumor-immune ecosystem in shaping metastasis

A better understanding of the mechanisms regulating cancer metastasis is critical to develop new therapies and decrease mortality. Emerging evidence suggests that the interactions between tumor cells and the host immune system play important roles in establishing metastasis. Tumor cells are able to recruit immune cells, which in turn promotes tumor cell invasion, intravasation, survival in circulation, extravasation, and colonization in different organs. The tumor-host immunological interactions also generate a premetastatic niche in distant organs which facilitates metastasis. In this review, we summarize the recent findings on how tumor cells and immune cells regulate each other to coevolve and promote the formation of metastases at the major organ sites of metastasis.

Chondroitin polymerizing factor predicts a poor prognosis and promotes breast cancer progression via the upstream TGF-β1/SMAD3 and JNK axis activation

Aberrant composition of glycans in the tumor microenvironment (TME) contributes to tumor progression and metastasis. Chondroitin polymerizing factor (CHPF) is a glycosyltransferase that catalyzes the biosynthesis of chondroitin sulfate (CS). It is also correlated to transforming growth factor-β1 (TGF-β1) expression, a crucial mediator in the interaction of cancer cells with TME. In this study, we investigated the association of CHPF expression with the clinicopathological features of breast cancer (BRCA), as well the oncogenic effect and the underling mechanisms of CHPF upon BRCA cells. We found that CHPF expression is significantly increased in human BRCA tissues, and it is positively associated with TGF-β expression (r = 0.7125). The high-expression of CHPF predicts a poor prognosis and is positively correlated with tumor mass, lymph node metastasis, clinical staging and HER-2 negative-expression. The mechanistic study revealed that it promotes BRCA cell proliferation, migration and invasion through TGF-β1-induced SMAD3 and JNK activation in vitro, JNK (SP600125) or SMAD3 (SIS3) inhibitor can remove the promotion of CHPF upon cell proliferation, migration and invasion in MDA-MB-231 cells, which is derived from triple-negative breast cancer (TNBC). Collectively, our finding suggested CHPF may function as an oncogene and is highly expressed in human BRCA tissues. Pharmacological blockade of the upstream of JNK or SMAD3 signaling may provide a novel therapeutic target for refractory TNBC patients with CHPF abnormal high-expression.

The role of macrophages-mediated communications among cell compositions of tumor microenvironment in cancer progression

Recent studies have revealed that tumor-associated macrophages are the most abundant stromal cells in the tumor microenvironment and play an important role in tumor initiation and progression. Furthermore, the proportion of macrophages in the tumor microenvironment is associated with the prognosis of patients with cancer. Tumor-associated macrophages can polarize into anti-tumorigenic phenotype (M1) and pro-tumorigenic phenotype (M2) by the stimulation of T-helper 1 and T-helper 2 cells respectively, and then exert opposite effects on tumor progression. Besides, there also is wide communication between tumor-associated macrophages and other immune compositions, such as cytotoxic T cells, regulatory T cells, cancer-associated fibroblasts, neutrophils and so on. Furthermore, the crosstalk between tumor-associated macrophages and other immune cells greatly influences tumor development and treatment outcomes. Notably, many functional molecules and signaling pathways have been found to participate in the interactions between tumor-associated macrophages and other immune cells and can be targeted to regulate tumor progression. Therefore, regulating these interactions and CAR-M therapy are considered to be novel immunotherapeutic pathways for the treatment of malignant tumors. In this review, we summarized the interactions between tumor-associated macrophages and other immune compositions in the tumor microenvironment and the underlying molecular mechanisms and analyzed the possibility to block or eradicate cancer by regulating tumor-associated macrophage-related tumor immune microenvironment.

Inhibition of WNT signaling by conjugated microRNA nano-carriers: A new therapeutic approach for treating triple-negative breast cancer a perspective review

Triple-Negative Breast Cancer is the most aggressive form and accounts the 15%-25% of all breast cancer. Receptors are absent in triple-negative breast cancer, which makes them unresponsive to the current hormonal therapies. The patients with TNBC are left with the option of cytotoxic chemotherapy. The Wnt pathways are connected to cancer, and when activated, they result in mammary hyperplasia and tumors. The tumor suppressor microRNAs can block tumor cell proliferation, invasion, and migration, lead to cancer cell death, and are also known to down-regulate the WNT signaling. Nanoparticles with microRNA have been seen to be more effective when compared with their single release. In this review, we have tried to understand how Wnt signaling plays a crucial role in TNBC, EMT, metastasis, anti-drug resistance, and regulation of Wnt by microRNA. The role of nano-carriers in delivering micro-RNA. The clinical biomarkers, including the present state-of-the-art, involve novel pathways of Wnt.

3D genome alterations in T cells associated with disease activity of systemic lupus erythematosus

OBJECTIVES

Three-dimensional (3D) genome alterations can dysregulate gene expression by rewiring physical interactions within chromosomes in a tissue-specific or cell-specific manner and lead to diseases. We aimed to elucidate the 3D genome structure and its role in gene expression networks dysregulated in systemic lupus erythematosus (SLE).

METHODS

We performed Hi-C experiments using CD4+ T cells from 7 patients with SLE and 5 age-matched and sex-matched healthy controls (HCs) combined with RNA sequencing analysis. Further integrative analyses, including transcription factor motif enrichment, SPI1 knockdown and histone modifications (H3K27ac, H3K4me1, H3K4me3), were performed for altered loop-associated gene loci in SLE.

RESULTS

We deciphered the 3D chromosome organisation in T cells of patients with SLE and found it was clearly distinct from that of HCs and closely associated with the disease activity of SLE. Importantly, we identified loops within chromosomes associated with the disease activity of SLE and differentially expressed genes and found some key histone modifications close to these loops. Moreover, we demonstrated the contribution of the transcription factor SPI1, whose motif is located in the altered loop in SLE, to the overexpression of interferon pathway gene. In addition, we identified the potential influences of genetic variations in 3D genome alterations in SLE.

CONCLUSIONS

Our results highlight the 3D genome structure alterations associated with SLE development and provide a foundation for future interrogation of the relationships between chromosome structure and gene expression control in SLE.

Meso-Hannokinol inhibits breast cancer bone metastasis via the ROS/JNK/ZEB1 axis

Distal metastases from breast cancer, especially bone metastases, are extremely common in the late stages of the disease and are associated with a poor prognosis. EMT is a biomarker of the early process of bone metastasis, and MMP-9 and MMP-13 are important osteoclastic activators. Previously, we found that meso-Hannokinol (HA) could significantly inhibit EMT and MMP-9 and MMP-13 expressions in breast cancer cells. On this basis, we further explored the role of HA in breast cancer bone metastasis. In vivo, we established a breast cancer bone metastasis model by intracardially injecting breast cancer cells. Intraperitoneal injections of HA significantly reduced breast cancer cell metastasis to the leg bone in mice and osteolytic lesions caused by breast cancer. In vitro, HA inhibited the migration and invasion of breast cancer cells and suppressed the expressions of EMT, MMP-9, MMP-13, and other osteoclastic activators. HA inhibited EMT and MMP-9 by activating the ROS/JNK pathway as demonstrated by siJNK and SP600125 inhibition of JNK phosphorylation and NAC scavenging of ROS accumulation. Moreover, HA promoted bone formation and inhibited bone resorption in vitro. In conclusion, our findings suggest that HA may be an excellent candidate for treating breast cancer bone metastasis.

Propofol-Induced miR-493-3p Inhibits Growth and Invasion of Gastric Cancer through Suppression of DKK1-Mediated Wnt/β-Catenin Signaling Activation

Purpose

Gastric cancer (GC) is one of the most common malignant tumors and also one of the most deadly tumors. In recent years, studies have shown that propofol can inhibit the proliferation and metastasis of many tumor cells. In the present study, we aimed to investigate the underlying mechanism of propofol inhibition of the growth and invasion of GC cells.

Methods

Human gastric cancer cell line SGC-7901 and human normal gastric epithelial cell GES-1 were cultured in high-glucose Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal bovine serum at 37°C with 5% CO₂. Propofol of different concentrations (0, 2, 5, and 10 μg/mL) was used to treat SGC-7901, and miR-493-3p inhibitor was transfected into SGC-7901. The cell proliferation of SGC-7901 was analyzed by MTT as well as colony formation assay. The qRT-PCR was used to assess the expression of mRNA for key genes. We examined the protein expression of DKK1 and relative markers with western blot. Putative binding places of miR-493-3p on the 3'-untranslated area of DKK1 were predicted using bioinformatics and dual-luciferase method.

Results

Propofol prohibited phenotypic features of GC, according to our findings. Furthermore, research into the underlying mechanisms of propofol's suppressive effects in GC cell proved that propofol therapy improved the degrees of expression of the potential tumor suppressor miR-493-3p. The inhibiting properties of propofol on GC cell development, migration, and invasion were abolished when propofol-induced miR493-3p was silenced with anti-miR-493-3p. We also found that this drug reversed epithelial-mesenchymal transformation in SGC-7901 cells via inducing miR-493-3p. Propofol-induced miR-493-3p decreases GC cell development via targeting DKK1 and hence inhibits Wnt/β-catenin signaling, according to these findings.

Conclusion

Propofol-induced miR-493-3p decreased GC cell development via targeting DKK1 and hence inhibited Wnt/β-catenin signaling, according to these findings.

Immune suppressive signaling regulated by latent transforming growth factor beta binding protein 1 promotes metastasis in cervical cancer

Although metastasis is the major cause of death in cervical cancer, the mechanism of metastasis is still unclear. The mRNA expression and protein level of latent transforming growth factor beta binding protein 1 (LTBP1) were detected in tumor tissues and paracancerous tissues from in-house samples. Cell proliferation, cell cycle, migration, and in vivo metastasis were determined after LTBP1 was knocked down. Then, 13 drugs were screened, and the changes in cell apoptosis and proliferation and tumor metastasis were detected after drug treatment in shRNA cells. In our in-house samples, LTBP1 was lowly expressed in cervical cancer tissues. After LTBP1 knockdown, cell proliferation was increased, and the ability of in vitro migration and in vivo metastasis was enhanced. At the same time, the proportion of myeloid derived suppressor cells (MDSC) in situ increased, the proportion of T cells decreased, and transforming growth factor beta-1 (TGFβ1) signaling was activated. After carboplatin treatment, LTBP1 shRNA cell line apoptosis increased, metastasis in vivo was limited, and the proportion of MDSC in situ decreased. LTBP1 was lowly expressed in cervical cancer, and the inhibition of LTBP1 can improve the malignant degree of the tumor, and this process can be blocked by carboplatin.

Cancer stem cell-immune cell collusion in immunotherapy

Immunotherapy has pioneered a new era of tumor treatment, in which the immune checkpoint blockade (ICB) exerts significant superiority in overcoming tumor immune escape. However, the formation of an immune-suppressive tumor microenvironment (TME) and the lack of effective activation of the immune response have become major obstacles limiting its development. Emerging reports indicate that cancer stem cells (CSCs) potentially play important roles in treatment resistance and progressive relapse, while current research is usually focused on CSCs themselves. In this review, we mainly emphasize the collusions between CSCs and tumor-infiltrating immune cells. We focus on the summary of CSC-immune cell crosstalk signaling pathways in ICB resistance and highlight the application of targeted drugs to improve the ICB response.

Correlation of NNMT and DKK1 Protein Expression With Clinicopathological Characteristics and Prognosis of Breast Cancer

Background

Nicotinamide N-methyltransferase (NNMT) and Dickkopf-1 (DKK1) play an important role in the development of breast cancer, and the purpose of this study was designed to examine the clinical and prognostic significance of NNMT and DKK1 in breast cancer.

Methods

The GEPIA2 database was used to evaluate the expression and survival of NNMT mRNA and DKK1 mRNA of breast cancer. Then an immunohistochemical study was carried out on 374 cases of breast tissue to identify the protein expression and significance of NNMT and DKK1. Next, the prognostic significance of DKK1 in breast cancer was explored by COX and Kaplan-Meier models.

Results

Protein NNMT expression was correlated with lymph node metastasis and histological grade (P < .05) while protein DKK1 expression was related to tumor size, pT stage, histological grade, and Ki-67 (P < .05). Protein DKK1 was related to disease-specific survival (DSS), and low DKK1 expression indicated a poor prognosis of breast cancer patients (P < .05). Combined expression of protein NNMT and protein DKK1 predicted different prognosis of DSS (P < .05).

Conclusions

Nicotinamide N-methyltransferase and DKK1 were linked to breast cancer malignancy and invasion. Breast cancer patients with low DKK1 expression had a worse prognosis. Oncotypes of NNMT and DKK1 expression predicted patient outcomes.

LTBP1 Gene Expression in the Cerebral Cortex and its Neuroprotective Mechanism in Mice with Postischemic Stroke Epilepsy

OBJECTIVE

This study aimed at exploring the expression level of LTBP1 in the mouse model of epilepsy. The mechanism of LTBP1 in epileptic cerebral neural stem cells was deeply investigated to control the occurrence of epilepsy with neuroprotection.

METHODS

qRT-PCR was conducted for the expression levels of LTBP1 in clinical human epileptic tissues and neural stem cells, as well as normal cerebral tissues and neural stem cells. The mouse model of postischemic stroke epilepsy (PSE) was established by the middle cerebral artery occlusion (MCAO). Then, qRT-PCR was conducted again for the expression levels of LTBP1 in mouse epileptic tissues and neural stem cells as well as normal cerebral tissues and neural stem cells. The activation and inhibitory vectors of LTBP1 were constructed to detect the effects of LTBP1 on the proliferation of cerebral neural stem cells in the PSE model combined with CCK-8. Finally, Western blot was conducted for the specific mechanism of LTBP1 affecting the development of epileptic cells.

RESULTS

Racine score and epilepsy index of 15 mice showed epilepsy symptoms after the determination with MCAO, showing a successful establishment of the PSE model. LTBP1 expression in both diseased epileptic tissues and cells was higher than that in normal clinical epileptic tissues and cells. Meanwhile, qRT-PCR showed higher LTBP1 expression in both mouse epileptic tissues and their neural stem cells compared to that in normal tissues and cells. CCK-8 showed that the activation of LTBP1 stimulated the increased proliferative capacity of epileptic cells, while the inhibition of LTBP1 expression controlled the proliferation of epileptic cells. Western blot showed an elevated expression of TGFβ/SMAD signaling pathway-associated protein SMAD1/5/8 after activating LTBP1. The expression of molecular MMP-13 associated with the occurrence of inflammation was also activated.

CONCLUSION

LTBP1 can affect the changes in inflammation-related pathways by activating the TGFβ/SMAD signaling pathway and stimulate the development of epilepsy, and the inhibition of LTBP1 expression can control the occurrence of epilepsy with neuroprotection.

RAC1, a Potential Diagnostic and Prognostic Marker for Diffuse Large B Cell Lymphoma

The gene changes for diagnosis and prognosis of diffuse large B cell lymphoma (DLBCL) still remain unclear. RAC1 was reported to be asso;ciated with the B cell receptor signal pathway, but its relations with DLBCL have not yet been systematically explored. In this study, we have conducted molecular, bioinformatics and clinical analyses by using publicly available data from The Cancer Genome Atlas (TCGA). Wilcoxon signed-rank test and logistic regression were performed to evaluate the association between RAC1 and clinical features in patients. Kaplan-Meier and Cox regression methods were used to examine the impacts of RAC1 expression level on overall survival, and a nomogram was performed to illustrate the correlation between RAC1 and the risk of DLBCL. Our results revealed that the expression level of RAC1 in DLBCL was higher than that in normal tissues or lymphadenitis. High-level expression of RAC1 was significantly associated with clinical stage, as well as being an independent factor affecting overall survival. RAC1 was negatively correlated with Bruton's tyrosine kinase (BTK). The association between RAC1 gene expression and the risk of DLBCL was presented in a nomogram. In conclusion, RAC1 expression patterns may be used to predict the development and prognosis of DLBCL.

Wnt Signaling in the Development of Bone Metastasis

Wnt signaling occurs through evolutionarily conserved pathways that affect cellular proliferation and fate decisions during development and tissue maintenance. Alterations in these highly regulated pathways, however, play pivotal roles in various malignancies, promoting cancer initiation, growth and metastasis and the development of drug resistance. The ability of cancer cells to metastasize is the primary cause of cancer mortality. Bone is one of the most frequent sites of metastases that generally arise from breast, prostate, lung, melanoma or kidney cancer. Upon their arrival to the bone, cancer cells can enter a long-term dormancy period, from which they can be reactivated, but can rarely be cured. The activation of Wnt signaling during the bone metastasis process was found to enhance proliferation, induce the epithelial-to-mesenchymal transition, promote the modulation of the extracellular matrix, enhance angiogenesis and immune tolerance and metastasize and thrive in the bone. Due to the complexity of Wnt pathways and of the landscape of this mineralized tissue, Wnt function during metastatic progression within bone is not yet fully understood. Therefore, we believe that a better understanding of these pathways and their roles in the development of bone metastasis could improve our understanding of the disease and may constitute fertile ground for potential therapeutics.

The road of NSCLC stem cells toward bone metastases

Despite advancement in therapeutic options, Non-Small Cell lung cancer (NSCLC) remains a lethal disease mostly due to late diagnosis at metastatic phase and drug resistance. Bone is one of the more frequent sites for NSCLC metastatization. A defined subset of cancer stem cells (CSCs) that possess motile properties, mesenchymal features and tumor initiation potential are defined as metastasis initiating cells (MICs). A better understanding of the mechanisms supporting MIC dissemination and interaction with bone microenvironment is fundamental to design novel rational therapeutic option for long lasting efficient treatment of NSCLC. In this review we will summarize findings about bone metastatic process initiated by NSCLC MICs. We will review how MICs can reach bone and interact with its microenvironment that supports their extravasation, seeding, dormancy/proliferation. The role of different cell types inside the bone metastatic niche, such as endothelial cells, bone cells, hematopoietic stem cells and immune cells will be discussed in regards of their impact in dictating the success of metastasis establishment by MICs. Finally, novel therapeutic options to target NSCLC MIC-induced bone metastases, increasing the survival of patients, will be presented.

SMARCC2 mediates the regulation of DKK1 by the transcription factor EGR1 through chromatin remodeling to reduce the proliferative capacity of glioblastoma

Switch/sucrose-nonfermenting (SWI/SNF) complexes play a key role in chromatin remodeling. Recent studies have found that SMARCC2, as the core subunit of the fundamental module of the complex, plays a key role in its early assembly. In this study, we found a unique function of SMARCC2 in inhibiting the progression of glioblastoma by targeting the DKK1 signaling axis. Low expression of SMARCC2 is found in malignant glioblastoma (GBM) compared with low-grade gliomas. SMARCC2 knockout promoted the proliferation of glioblastoma cells, while its overexpression showed the opposite effect. Mechanistically, SMARCC2 negatively regulates transcription by dynamically regulating the chromatin structure and closing the promoter region of the target gene DKK1, which can be bound by the transcription factor EGR1. DKK1 knockdown significantly reduced the proliferation of glioblastoma cell lines by inhibiting the PI3K-AKT pathway. We also studied the functions of the SWIRM and SANT domains of SMARCC2 and found that the SWIRM domain plays a more important role in the complete chromatin remodeling function of SMARCC2. In addition, in vivo studies confirmed that overexpression of SMARCC2 could significantly inhibit the size of intracranial gliomas in situ in nude mice. Overall, this study shows that SMARCC2, as a tumor suppressor, inhibits the proliferation of glioblastoma by targeting the transcription of the oncogene DKK1 through chromatin remodeling, indicating that SMARCC2 is a potentially attractive therapeutic target in glioblastoma.

Exosomes in bone remodeling and breast cancer bone metastasis

Exosomes are endosome-derived microvesicles that carry cell-specific biological cargo, such as proteins, lipids, and noncoding RNAs (ncRNAs). They play a key role in bone remodeling by enabling the maintenance of a balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Recent evidence indicates that exosomes disrupt bone remodeling that occurs during breast cancer (BC) progression. The bone is a preferred site for BC metastasis owing to its abundant osseous reserves. In this review, we aimed to highlight the roles of exosomes derived from bone cells and breast tumor in bone remodeling and BC bone metastasis (BCBM). We also briefly outline the mechanisms of action of ncRNAs and proteins carried by exosomes secreted by bone and BCBM. Furthermore, this review highlights the potential of utilizing exosomes as biomarkers or delivery vehicles for the diagnosis and treatment of BCBM.

DKK1 as a robust predictor for adjuvant platinum chemotherapy benefit in resectable pStage II-III gastric cancer

BACKGROUND

Adjuvant chemotherapy (ACT) with 5-FU alone or 5-FU plus platinum after curative surgery improves the prognosis of pStage II-III gastric cancer (GC). However, only a subset of patients benefits from adjuvant platinum. To avoid the side effects of platinum, it is significant to accurately screen the patients who would benefit maximally with this treatment. The present study aimed to assess the value of DKK1 in predicting the benefit of adjuvant platinum chemotherapy in patients with pStage II -III GC.

METHODS

Platinum sensitivity-related genes were screened by bioinformatics. DKK1 expression in 380 GC specimens was detected by immunohistochemistry (IHC) staining, and the correlation with adjuvant platinum-specific benefits were analyzed.

RESULTS

DKK1 was screened as the most significant platinum sensitivity-related gene. In patients with DKK1^high GC, the estimated absolute 5-year overall survival (OS) benefits from adjuvant platinum for pStage II-III, II, IIIA, IIIB, and IIIC were 25.5%, 17.3%, 36.4%, 29.2% and 31.1%, respectively, and the estimated absolute 5-year disease-free survival (DFS) benefits in the corresponding stages were 27.4%, 17.5%, 36.7%, 29.7% and 31.5%, respectively. These benefits were significantly higher than those in the same TNM stage without adjusting for DKK1 status. The performance of DKK1 was independent of the TNM stage and other clinicopathological variables. Similar results were obtained in the TCGA and ACRG cohorts. Furthermore, nomograms were constructed to predict the survival benefits in DKK1 subgroups.

CONCLUSIONS

The stratification strategy based on DKK1 status is more precise than the TNM staging system for the selection of pStage II-III GC patients suitable for platinum-containing ACT.

Identification of nine mutant genes and establishment of three prediction models of organ tropism metastases of non-small cell lung cancer

BACKGROUND

Most Non-small cell lung cancer (NSCLC) patients tend to have metastases at the initial diagnosis. However, limited knowledge has been established regarding which factors, are associated with its metastases. This study aims to identify more biomarkers associated with its organ tropism metastasis and to establish models for prediction of its metastatic organs.

METHODS

We performed targeted next-generation sequencing (NGS) to detect genes related to lung cancer in 272 patients with primary advanced NSCLC from Northeast China. We adopted Fisher test, multivariate logistic regression analysis to identify metastasis-related gene mutations and to establish prediction models.

RESULTS

Mutations of EGFR (p = 0.0003, OR = 2.554) (especially EGFR L858R [p = 0.02, OR = 2.009]), ATM (p = 0.008, OR = 11.032), and JAK2 (p = 0.009, OR = Inf) were positively and of TP53 exon4mut (p = 0.001, OR = 0.173) was negatively correlated with lung metastasis, and those of CSF1R (p = 0.01, OR = Inf), KIT (p = 0.03, OR = 4.746), MYC (p = 0.05, OR = 7.938), and ERBB2 (p = 0.02, OR = 2.666) were positively correlated with pleural dissemination; those of TP53 (p = 0.01, OR = 0.417) was negatively, while of SMAD4 (p = 0.03, OR = 4.957) was positively correlated with brain metastasis of NSCLC. Additionally, smoking history (p = 0.004, OR = 0.004) was negatively correlated with pleural dissemination of NSCLC. Furthermore, models for prediction of lung metastasis (AUC = 0.706), pleural dissemination (AUC = 0.651), and brane metastasis (AUC = 0.629) were established.

CONCLUSION

Taken together, this study revealed nine mutant genes and smoking history associated with organ tropism metastases of NSCLC and provided three models for the prediction of metastatic organs. This study enables us to predict the organs to which non-small cell lung cancer metastasizes before it does develop.

Biological and Clinical Aspects of Metastatic Spinal Tumors

Simple Summary

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Our literature review aimed to describe the up-to-date knowledge about the molecular pathways and biomarkers engaged in the spine’s metastatic processes. Moreover, we described current data regarding bone-targeted treatment, the emerging targeted therapies, radiotherapy, and immunotherapy used for the treatment of spine metastases. We hope that knowledge comprehensively presented in our review will contribute to the development of novel drugs targeting specific biomarkers and pathways. The more we learn about the molecular aspects of cancer metastasis, the easier it will be to look for treatment methods that will allow us to precisely kill tumor cells.

Abstract

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Thanks to continuous research, there appears more and more detailed knowledge about cancer and metastasis, but these transformations are extremely complicated, e.g., due to the complexity of reactions, the variety of places where they occur, or the participation of both tumor cells and host cells in these transitions. The right target points in tumor metastasis mechanisms are still being researched; that will help us in the proper diagnosis as well as in finding the right treatment. In this literature review, we described the current knowledge about the molecular pathways and biomarkers engaged in metastatic processes involving the spine. We also presented a current bone-targeted treatment for spine metastases and the emerging therapies targeting the discussed molecular mechanisms.