Wnt/β-catenin pathway in bone cancers

Impact of Genetic Polymorphisms on Treatment Outcomes of Proteasome Inhibitors and Immunomodulatory Drugs in Multiple Myeloma

OPINION STATEMENT

Multiple myeloma (MM) is classified as a lymphoproliferative disorder that remains an incurable malignancy despite improved patient survival with new drug therapies. Polymorphisms are essential in determining the effectiveness and outcome of treatments in MM. Despite significant advances, there needs to be more understanding of the underlying biological mechanisms that determine treatment outcomes. studies show that investigating gene polymorphisms involved in drug metabolism, DNA repair, inflammation, and apoptosis pathways can predict the effectiveness of treatment in MM patients. Therefore, these findings emphasize the potential of genetic profiling for predicting treatment outcomes and tailoring treatments to individual genetic profiles, which increases the efficiency and reduces the toxicity of MM treatments.

IMP3, CDK4, MDM2 and β-catenin expression in Enchondroma and Central Chondrosarcoma: Diagnostic and prognostic utility

INTRODUCTION

The role of IMP3, CDK4, MDM2 and β-catenin proteins in Enchondroma and Central Chondrosarcoma is not totally understood. The aim of this study is to evaluate the immunoexpression of these proteins, associating histological grade, clinical data and prognosis to these tumors.

METHODS

This is a retrospective-analytical study of 32 Enchondroma and 70 Central Chondrosarcoma.

RESULTS

IMP3, CDK4, MDM2 and β-catenin expression was observed in 22.82 %, 13.82 %, 17.17 % and in 8.8 % of cases, respectively. All Enchondromas positive for these immunomarkers were located in short tubular bones. The positivity for these antibodies is directly proportional to Chondrosarcoma's histological grade increase. No difference was found between Enchondroma and Chondrosarcoma, Grade 1 for IMP3, CDK4 and ß-catenin positivity. Significant metastasis outcome was observed for IMP3, CDK4, MDM2 and death for MDM2 expression.

CONCLUSION

IMP3, CDK4, MDM2 and β-catenin expression in Enchondromas of short bones phenotypically characterizes these tumors. Their expression has not proven to be useful either as diagnostic markers of these neoplasms or in distinguishing between Enchondroma and Chondrosarcoma, Grade 1. The significant immunoexpression of IMP3, CDK4 and MDM2 in metastatic Chondrosarcoma and the lower survival in those with positivity for MDM2 suggest a possible association of these proteins with tumor aggressiveness.

Targeting WNT5B and WNT10B in osteosarcoma

WNT signaling regulates osteosarcoma proliferation. However, there is controversy in the field of osteosarcoma as to whether WNT signaling is pro- or anti-tumorigenic. WNT-targeting therapeutics, both activators and inhibitors, are compared. WNT5B, a β-catenin-independent ligand, and WNT10B, a β-catenin-dependent WNT ligand, are each expressed in osteosarcomas, but they are not expressed in the same tumors. Furthermore, WNT10B and WNT5B regulate different histological subtypes of osteosarcomas. Using WNT signaling modulators as therapeutics may depend on the WNT ligand and/or the activated signaling pathway.

The therapeutic effect of traditional Chinese medicine on breast cancer through modulation of the Wnt/β-catenin signaling pathway

Breast cancer, the most prevalent malignant tumor among women globally, is significantly influenced by the Wnt/β-catenin signaling pathway, which plays a crucial role in its initiation and progression. While conventional chemotherapy, the standard clinical treatment, suffers from significant drawbacks like severe side effects, high toxicity, and limited prognostic efficacy, Traditional Chinese Medicine (TCM) provides a promising alternative. TCM employs a multi-targeted therapeutic approach, which results in fewer side effects and offers a high potential for effective treatment. This paper presents a detailed analysis of the therapeutic impacts of TCM on various subtypes of breast cancer, focusing on its interaction with the Wnt/β-catenin signaling pathway. Additionally, it explores the effectiveness of both monomeric and compound forms of TCM in the management of breast cancer. We also discuss the potential of establishing biomarkers for breast cancer treatment based on key proteins within the Wnt/β-catenin signaling pathway. Our aim is to offer new insights into the prevention and treatment of breast cancer and to contribute to the standardization of TCM.

The Effects and Mechanisms of Sennoside A on Inducing Cytotoxicity, Apoptosis, and Inhibiting Metastasis in Human Chondrosarcoma Cells

Currently, developing therapeutic strategies for chondrosarcoma (CS) remains important. Sennoside A (SA), a dianthrone glycoside from Senna and Rhubarb, is widely used as an irritant laxative, weight-loss agent, or dietary supplement, which possesses various bioactive properties such as laxative, antiobesity, and hypoglycemic activities. For the first time, our results suggested that cell proliferation and metastasis were inhibited by SA in CS SW1353 cells. SA induced cell growth arrest by inhibiting cell proliferation. The changes of N-cadherin and E-cadherin levels, the markers associated with epithelial mesenchymal transition (EMT), suggested the EMT-related mechanism of SA in inhibiting cell metastasis. Besides, SA significantly stimulated apoptosis in CS SW1353 cells, leading to cell death. The increase of Bax/Bcl2 ratio confirmed that the internal mitochondrial pathway of apoptosis was regulated by SA. In addition, the prediction of network pharmacology analysis suggested that the possible pathways of SA treatment for CS included the Wnt signaling pathway. Notably, the protein levels of the components in the Wnt pathway, such as Wnt3a, β-catenin, and c-Myc, were downregulated by SA in CS SW1353 cells. To sum up, these results demonstrated that the suppression of the growth, metastasis and the stimulation of cytotoxicity, and apoptosis mediated by SA in CS SW1353 cells were possibly caused by the inhibition of the Wnt/β-catenin pathway, indicating an underlying therapeutic prospect of SA for chondrosarcoma.

WNT1 expression influences the development of dysplasia of the hip via regulating RBPMS2/NOG-BMP2/4-GDF5- WISP2 pathway

OBJECTIVE

To explore the role of WNT family member 1 (WNT1) in the development of dysplasia of the hip (DDH) and the molecular mechanism involved in this process. Methods: Si-WNT1, pcDNA3.1-WNT1 or corresponding negative controls were transfected into human osteoblast hFOB1.19 and human chondrocyte C28/I2, respectively. The proliferation of cells was measured by EdU assay. The relative expressions of human noggin gene (NOG), growth differentiating factor 5 (GDF5), WNT1, and WNT1-inducible-signaling pathway protein 2 (WISP2) were determined by immunofluorescence analysis. The protein expressions of RNA-binding protein of multiple splice forms 2 (RBPMS2), NOG, bone morphogenetic protein 2 (BMP2), BMP4, WNT1 and WISP2 were determined by western blot. Animal experiment was also performed and the morphological development of hip joint was observed. Results: Overexpression of WNT1 promoted osteoblast proliferation and inhibited chondrocyte proliferation, while knockdown of WNT1 inhibited osteoblast proliferation. In chondrocytes, knockdown of WNT1 upregulated NOG expression, while overexpression of WNT1 downregulated its expression. In osteoblasts and chondrocytes, overexpression of WNT1 increased BMP2, BMP4, WNT1, and WISP2 expression. RBPMS2 and NOG were slightly expressed in each group. Conclusion: Overexpression of WNT1 promoted osteoblast proliferation, inhibited chondrocyte proliferation, and increased the expressions of BMP2, BMP4, WNT1, and WISP2. Therefore, WNT1 may be a new therapeutic target for DDH.

BAIAP2L2 promotes the proliferation, migration and invasion of osteosarcoma associated with the Wnt/β-catenin pathway

BACKGROUND

Osteosarcoma is the most common bone cancer that significantly affects the quality of life of patients. Studies have shown that overexpression of BAIAP2L2 elevates the proliferation and growth of some types of cancer cells. However, the role of BAIAP2L2 in osteosarcoma is unclear. This study aimed to investigate the functions of BAIAP2L2 in the development of osteosarcoma.

METHODS

We used immunohistochemical and Western blot analysis to determine the expression levels of endogenic BAIAP2L2 in osteosarcoma cells. Cell counting kit-8 assay and colony formation assay were performed to investigate cell proliferation of tumor cells. Transwell assay was performed to detect cell migration. Flow cytometry assay was used to analyze cell apoptosis. The role of BAIAP2L2 in tumor growth was further explored in vivo.

RESULTS

We found that BAIAP2L2 was significantly upregulated in human osteosarcoma, and inhibition of BAIAP2L2 suppressed the proliferation of osteosarcoma cells. In addition, down-regulation of BAIAP2L2 could lead to osteosarcoma cancer cell apoptosis, inhibit cell migration and invasion, and induce the inactivation of the Wnt/β-catenin pathway. In addition, down-regulation of BAIAP2L2 inhibited tumor growth in vivo.

CONCLUSION

In conclusion, down-regulation of BAIAP2L2 inhibited the proliferation, migration, and invasion of osteosarcoma associated with the Wnt/β-catenin pathway.

Wnt/β-catenin signal transduction pathway in prostate cancer and associated drug resistance

Globally, prostate cancer ranks second in cancer burden of the men. It occurs more frequently in black men compared to white or Asian men. Usually, high rates exist for men aged 60 and above. In this review, we focus on the Wnt/β-catenin signal transduction pathway in prostate cancer since many studies have reported that β-catenin can function as an oncogene and is important in Wnt signaling. We also relate its expression to the androgen receptor and MMP-7 protein, both critical to prostate cancer pathogenesis. Some mutations in the androgen receptor also impact the androgen-β-catenin axis and hence, lead to the progression of prostate cancer. We have also reviewed MiRNAs that modulate this pathway in prostate cancer. Finally, we have summarized the impact of Wnt/β-catenin pathway proteins in the drug resistance of prostate cancer as it is a challenging facet of therapy development due to the complexity of signaling pathways interaction and cross-talk.

Targeting Wnt/β-catenin signaling by microRNAs as a therapeutic approach in chemoresistant osteosarcoma

Osteosarcoma (OS) is an adolescent and young adult malignancy that mostly occurs in long bones. The treatment of OS is still a big challenge for clinicians due to increasing chemoresistance, and many efforts are being made today to find more beneficial treatments. In this regard, the use of microRNAs has shown a high capacity to develop promising therapies. By targeting cancer-involved signaling pathways, microRNAs reduce the cellular level of these protein pathways; thereby reducing the growth and invasion of tumors, and even leading cancer cells to apoptosis. One of these oncogenic pathways that play an important role in OS development and can be targeted by microRNAs is the Wnt/β-catenin signaling pathway. Hence, the first goal of this review article is to explain the cross-talk of microRNAs and the Wnt/β-catenin signaling in OS and then discussing recent findings of the use of microRNAs as a therapeutic approach in OS.

KAT6A, a novel regulator of β-catenin, promotes tumorigenicity and chemoresistance in ovarian cancer by acetylating COP1

Background: Ovarian cancer is a fatal gynecologic malignancy that is found worldwide and exhibits an insidious onset and a lack of early warning symptoms. Despite ongoing studies, the mechanistic basis of the aggressive phenotypes of ovarian cancer remains unclear. Lysine acetyltransferase 6A (KAT6A) is a MYST-type histone acetyltransferase (HAT) enzyme identified as an oncogene in breast cancer, glioblastoma and leukemia. However, the specific functions of KAT6A in ovarian cancer remain unclear. Methods: Immunohistochemistry (IHC) staining and western blotting were performed to characterize KAT6A protein expression in ovarian cancer tissues and cell lines. The biological functions of KAT6A in ovarian cancer were evaluated by cell proliferation, wound healing and transwell invasion assays in vitro. Tumorigenesis and metastasis assays were performed in nude mice to detect the role of KAT6A in vivo. Mass spectrometry and immunoprecipitation assays were performed to detect the KAT6A-COP1 interaction. An in vivo ubiquitination assay was performed to determine the regulation of β-catenin by KAT6A. Results: In the present study, we revealed that KAT6A expression is upregulated in ovarian cancer and is associated with patient overall survival. Downregulation of KAT6A markedly inhibited the proliferation and migration abilities of ovarian cancer cells in vivo and in vitro. Additionally, the inhibition of KAT6A induced apoptosis and enhanced the sensitivity of ovarian cancer cells to cisplatin. Furthermore, KAT6A bound to and acetylated COP1 at K294. The acetylation of COP1 impaired COP1 function as an E3 ubiquitin ligase and led to the accumulation and enhanced activity of β-catenin. Conclusions: Our findings suggest that the KAT6A/COP1/β-catenin signaling axis plays a critical role in ovarian cancer progression and that targeting the KAT6A/COP1/β-catenin signaling axis could be a novel strategy for treating ovarian cancer.

Equine Genital Squamous Cell Carcinoma Associated with EcPV2 Infection: RANKL Pathway Correlated to Inflammation and Wnt Signaling Activation

Simple Summary

Equine genital squamous cell carcinomas (egSCCs) associated with papilloma virus (PV) infection have been recently proposed as model for human PV-induced SCC. In both species, PV mucosal infections often induce cervical, oropharyngeal, penile, anal, vaginal, and vulvar cancer. The aim of this study was to clarify the molecular mechanisms behind egSCCs associated with equine papillomavirus 2 (EcPV2) infection investigating receptor activator of nuclear factor-kappa B ligand (RANKL), Wnt, and interleukin (IL)17 signaling pathways. RANKL has been recently demonstrated to play a crucial role in several human tumors, associated with a poor prognosis and metastatic spread; novel targeted therapies through RANKL silencing monoclonal antibodies have been undertaken. EcPV2-E6 DNA was checked, and viral presence was confirmed in 91% of cases, whereas oncogene expression was 60.8% for E6 and 34.7% for E2. RANKL, NFKBp50, NFKBp65, IL6, IL17, IL23p19, IL8, IL12p35, IL12p40, BCATN1, FOSL1, and LEF1 gene expression showed a significant upregulation in tumor samples compared to healthy tissues. Our results describe an inflammatory environment characterized by the increased expression of several cytokines and the activation of RANKL/RANK, IL17A, and canonical and non-canonical Wnt signaling pathways. These results may be helpful to identify new targets for immunotherapy strategies confirming egSCCs as a model for the human disease.

Abstract

Equine genital squamous cell carcinomas (egSCCs) are among the most common equine tumors after sarcoids, severely impairing animal health and welfare. Equus caballus papillomavirus type 2 (EcPV2) infection is often related to these tumors. The aim of this study was to clarify the molecular mechanisms behind egSCCs associated with EcPV2 infection, investigating receptor activator of nuclear factor-kappa B ligand (RANKL) signaling in NF-kB pathway, together with the Wnt and IL17 signaling pathways. We analyzed the innate immune response through gene expression evaluation of key cytokines and transcription factors. Moreover, Ki67 index was assessed with immunohistochemistry. EcPV2-E6 DNA was checked, and viral presence was confirmed in 21 positive out to 23 cases (91%). Oncogene expression was confirmed in 14 cases (60.8%) for E6 and in 8 (34.7%) for E2. RANKL, nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB)-p50, NFKBp65, interleukin (IL)-6, IL17, IL23p19, IL8, IL12p35, IL12p40, β-catenin (BCATN1), FOS like 1 (FOSL1), and lymphoid enhancer binding factor 1 (LEF1) showed a significant upregulation in tumor samples compared to healthy tissues. Our results describe an inflammatory environment characterized by the activation of RANKL/RANK and IL17 with the relative downstream pathways, and a positive modulation of inflammatory cytokines genes such as IL6 and IL8. Moreover, the increase of BCATN1, FOSL1, and LEF1 gene expression suggests an activation of both canonical and non-canonical Wnt signaling pathway that could be critical for carcinogenesis and tumor progression.

MiR-200a with CDC7 as a direct target declines cell viability and promotes cell apoptosis in Wilm's tumor via Wnt/β-catenin signaling pathway

MiR-200a acts as a key role in tumor malignant progression. This work purposed to assess the function of miR-200a in Wilm's tumor. Based on bioinformatics analysis, the expression, prognostic value and related pathways of miR-200a and CDC7 (a potential downstream molecule of miR-200a) in Wilm's tumor were analyzed. qRT-PCR was conducted to confirm the miR-200a level in Wilm's tumor cells. The luciferase reporter assay was carried out to verify the binding of miR-200a to 3'-UTR of CDC7. Then, the impacts of miR-200a and CDC7 on cell viability and apoptosis were measured using CCK-8 and flow cytometry assays. Also, western blot was applied to measure the expression of CDC7 as well as Wnt/β-catenin signaling pathway-related proteins and apoptosis proteins. Herein, we revealed that miR-200a was lowly expressed in Wilm's tumor tissues and cells and the low miR-200a expression is closely bound up with death and poor outcomes. Moreover, miR-200a directly targeted and inhibited CDC7 in Wilm's tumor cells. Biological function experiments illustrated that overexpression of miR-200a reduced the viability and elevated the apoptosis of Wilm's tumor cells, while overexpression of CDC7 reversed the inhibitory impact of miR-200a on cell viability and the promoting impact of miR-200a on cell apoptosis. Besides, we revealed that miR-200a/CDC7 axis can decrease the expression of β-Catenin, Cyclin D1 and C-Myc as well as the phosphorylation of GSK-3β, thus inhibiting the Wnt/β-catenin signaling pathway. Furthermore, blocking the Wnt/β-catenin signaling pathway caused an increase on cell apoptosis, while overexpression of CDC7 can reverse these impacts. Collectively, miR-200a/CDC7 axis involved in regulating the malignant phenotype of Wilm's tumor through Wnt/β-catenin signaling pathway, which provides a theoretical basis for targeted molecular therapy of Wilm's tumor.

LncRNA, Important Player in Bone Development and Disease

BACKGROUND

Bone is an important tissue and its normal function requires tight coordination of transcriptional networks and signaling pathways, and many of these networks/ pathways are dysregulated in pathological conditions affecting cartilage and bones. Long non-coding RNA (lncRNA) refers to a class of RNAs with a length of more than 200 nucleotides, lack of protein-coding potential, and exhibiting a wide range of biological functions. Although studies on lcnRNAs are still in their infancy, they have emerged as critical players in bone biology and bone diseases. The functions and exact mechanism of bone-related lncRNAs have not been fully classified yet.

OBJECTIVE

The objective of this article is to summarize the current literature on lncRNAs on the basis of their role in bone biology and diseases, focusing on their emerging molecular mechanism, pathological implications and therapeutic potential.

DISCUSSION

A number of lncRNAs have been identified and shown to play important roles in multiple bone cells and bone disease. The function and mechanism of bone-related lncRNA remain to be elucidated.

CONCLUSION

At present, majority of knowledge is limited to cellular levels and less is known on how lncRNAs could potentially control the development and homeostasis of bone. In the present review, we highlight some lncRNAs in the field of bone biology and bone disease. We also delineate some lncRNAs that might have deep impacts on understanding bone diseases and providing new therapeutic strategies to treat these diseases.

YJ5 as an immunohistochemical marker of osteogenic lineage

Overexpression of WLS, an upstream protein in the Wnt pathway, has been implicated in several non-osteogenic tumours. This study represents the first attempt at evaluating WLS expression in various bone and soft tissue tumours using YJ5, a monoclonal antibody specific to WLS, with the aim of elucidating its utility in discerning tumours with aberrant Wnt signalling and as a marker of osteogenic lineage in challenging cases. Tumour tissue sections of 144 bone mass lesions and 63 soft tissue mass lesions were immunostained with the YJ5 antibody following standardised protocols. Subsequent assessment of immunoreactivity segregated cases into one of three groups: absent/weak, moderate, or strong YJ5 immunoreactivity. For the bone tumours, strong YJ5 immunoreactivity was seen in almost all osteosarcomas and chondroblastomas, all osteoblastomas and osteoid osteomas. In contrast, all other cartilaginous tumours, chordomas, aneurysmal bone cysts, chondromyxoid fibromas, most fibrous dysplasias and most giant cell tumours exhibited absent/weak YJ5 immunostaining. For the soft tissue tumours, a more heterogeneous pattern of YJ5 immunoreactivity was observed. Because diffuse and strong YJ5 expression is identified in almost all benign and malignant bone tumours with osteoblastic activity, it can be potentially utilised as an immunohistochemical marker to support osteogenic lineage. If interpreted in the appropriate context, this marker is useful in determining whether a malignant bone tumour is an osteosarcoma, particularly in those subtypes with no or minimal osteoid or unusual morphological features. This marker can also complement SATB2 to denote osteogenic lineage.

The Sp1/FOXC1/HOTTIP/LATS2/YAP/β-catenin cascade promotes malignant and metastatic progression of osteosarcoma

The prognosis for osteosarcoma (OS) is dismal due to the aggressive tumor growth and high incidence of metastasis. The long noncoding RNA human homeobox A transcript at the distal tip (HOTTIP) and the transcription factor forkhead box C1 (FOXC1) present oncogenic activities in OS. Here, we aimed at gaining insights into the underlying mechanisms and their crosstalk. The expression of FOXC1 and HOTTIP in OS tissues or cell lines was examined by real-time PCR (RT-PCR) and western blot. The in vitro effects of FOXC1 or HOTTIP on cell viability, proliferation, migration, invasion, and expression of target genes were examined using MTT, colony-forming assay, wound-healing, Transwell invasion, and western blot, respectively; the in vivo effects were examined using xenograft and experimental metastasis models. Molecular control of HOTTIP on large tumor suppressor 2 (LATS2) or transactivation of FOXC1 or Sp1 on HOTTIP was assessed by combining RNA immunoprecipitation, qRT-PCR, western blot, ChIP, and luciferase assay. Both FOXC1 and HOTTIP were potently up-regulated in OS tissues and cell lines. FOXC1 and HOTTIP essentially maintained viability, proliferation, migration, and invasion of OS cells in vitro and contributed to xenograft growth or lung metastasis in vivo. Mechanistically, HOTTIP recruited enhancer of zeste homolog 2 (EZH2) and lysine-specific demethylase 1 (LSD1) to silence LATS2 and thus activated YAP/β-catenin signaling. Upstream, Sp1 activated FOXC1 and they both directly transactivated HOTTIP. In summary, we showed that the Sp1/FOXC1/HOTTIP/LATS2/YAP/β-catenin cascade presented oncogenic activities in OS cells. Targeting FOXC1 or HOTTIP may therefore prove beneficial for OS treatment.

β-Catenin: oncogenic role and therapeutic target in cervical cancer

Cervical cancer is a common and fatal malignancy of the female reproductive system. Human papillomavirus (HPV) is the primary causal agent for cervical cancer, but HPV infection alone is insufficient to cause the disease. Actually, most HPV infections are sub-clinical and cleared spontaneously by the host immune system; very few persist and eventually develop into cervical cancer. Therefore, other host or environmental alterations could also contribute to the malignant phenotype. One of the candidate co-factors is the β-catenin protein, a pivotal component of the Wnt/β-catenin signaling pathway. β-Catenin mainly implicates two major cellular activities: cell–cell adhesion and signal transduction. Recent studies have indicated that an imbalance in the structural and signaling properties of β-catenin leads to various cancers, such as cervical cancer. In this review, we will systematically summarize the role of β-catenin in cervical cancer and provide new insights into therapeutic strategies.

Effect of bortezomib on proliferation and apoptosis of myeloma cells by activating Wnt/β-catenin signaling pathway

Effect of bortezomib on proliferation and apoptosis of myeloma cells by activating Wnt/β-catenin signaling pathway was investigated. Myeloma cells RPMI-8226 treated with different concentrations of bortezomib were used as experimental groups, and the untreated cells were used as the control group. The proliferation and apoptosis in all groups of cells were detected, as well as the expression levels of Wnt/β-catenin signaling pathway-related proteins, β-catenin and c-Myc. The results revealed that bortezomib could inhibit the proliferation of myeloma cells. The apoptotic rates of RPMI-8226 cells in the groups treated with 20, 50 and 80 nmol/l of bortezomib were 12.08±0.61, 35.97±3.11 and 57.22±5.47%, respectively, which were significantly higher than that in the control group (8.28±0.39%) (P<0.05). The expression levels of β-catenin and c-Myc in the experimental groups were significantly lower than those in the control group (P<0.05). Bortezomib can reduce the expression level of Wnt/β-catenin signaling pathway-related proteins, β-catenin and c-Myc, and may inhibit cell proliferation and accelerate apoptosis by activating the Wnt/β-catenin signaling pathway.

The Impact of Beta-Catenin and glutathione-S-transferase Gene Polymorphisms on the Treatment Results and Survival of Multiple Myeloma Patients

Multiple myeloma (MM) is an incurable disease, however, novel therapeutic agents has significantly improved its prognosis. In this study we analyzed if polymorphisms in the genes of β-catenin and glutathione-S-transferase have affected the clinical course, treatment response and progression-free survival (PFS) of MM patients. Ninety-seven MM patients were involved who were administered immunomodulatory drug (Imid) or alkylating agent-based therapy. β-catenin (CTNNB1, rs4135385 A > G, rs4533622 A > C) and glutathione-S-transferase (GSTP1 105, GSTP1 114) gene polymorphisms were analyzed by Light SNiP assays. The distribution of CTNNB1 (rs4135385) AA, AG and GG genotypes were 48.4%, 47.4% and 4,1%, respectively. Patients with AA genotype were older than those who carried G allele (64.5 vs. 61.0 years of age, p < 0.05). Response to Imid-based therapies (p < 0.05) and PFS (p = 0.032) were significantly more favourable in the AA homozygous group. The other polymorphism (rs4533622) of β-catenin gene did not markedly influence these clinical parameters, although MM was diagnosed at significantly younger age in subjects with CC genotype compared to AG/AA combined genotypes (59.1 vs. 65.7 years, p = 0.015). When GSTP1 polymorphisms were investigated, no such significant associations were observed. Our results demonstrate that the polymorphism of β-catenin gene (rs4135385) may be an independent predictive factor in MM.

Prognostic Significance of β-Catenin Expression in Osteosarcoma: A Meta-Analysis

Background: β-catenin plays a crucial role in the progression of osteosarcoma. However, the clinical significance of β-catenin over-expression in osteosarcoma still remains unclear. Thus, we performed a meta-analysis of studies that evaluated the impact of β-catenin on metastasis and overall survival (OS) in osteosarcoma.

Methods: We searched PubMed, The Cochrane Library, Embase, Springer, Science Direct, OVID, Weipu, Wanfang and China National Knowledge Internet (CNKI) databases from their start year up to Aug.2019. Individual hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted and pooled HRs with 95% CIs or odd ratio (OR) were used to evaluate the relationships between β-catenin over-expression and metastasis and overall survival in osteosarcoma.

Results: Eight related studies involving 521 patients were qualified for this meta-analysis. Results showed that over-expression of β-catenin was significantly correlated with metastasis (OR = 3.31, 95% CI = 2.08–5.24, P < 0.001) and overall survival (HR = 2.32, 95% CI = 1.48–363, P = 0.02).

Conclusion: The meta-analysis revealed that over-expression of β-catenin might be associated with distant metastasis and overall survival in osteosarcoma, which reminds that β-catenin acts as a prognostic biomarker and it can guide the clinical therapy in osteosarcoma patients.

IL-1β secreted by macrophage M2 promotes metastasis of osteosarcoma via NF-κB/miR-181α-5p/RASSF1A/Wnt pathway

BACKGROUND

Ras-associated domain family protein1 isoform A (RASSF1A) was significantly absent in clinical samples and many osteosarcoma (OS) cell lines. Overexpression of RASSF1A could suppress OS metastasis, which may be mediated by tumor-associated macrophages polarized M2 (M2-TAMs). However, the relationship between IL-1β secreted by M2-TAMs and RASSF1A remains unknown.

METHODS

The expression levels of M2-TAMs markers CD68 and CD204 were measured by flow cytometry, and arginase-1 (Arg-1) and interleukin-1β (IL-1β) secreted by M2-TAMs were examined by real-time quantitative PCR (RT-qPCR). MTT assay was employed to determine the proliferation of OS cells, while scratch wound healing assay and Transwell assay were used to evaluate their migration and invasion, respectively. The level of miR-181α-5p was measured by RT-qPCR, while the levels of RASSF1A, GSK-3β, p-GSK-3β, β-catenin, MMP-2 and MMP-9 were evaluated by Western blot. The direct binding of miR-181α-5p and RASSF1A was identified using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

RESULTS

The levels of CD68, CD204, Arg-1 and IL-1β were elevated in M2-TAMs compared with control group. Overexpression of RASSF1A and knockdown of miR-181α-5p could both suppress invasion and migration of OS cells through Wnt pathway. IL-1β secreted by M2-TAMs facilitated the OS metastasis via RASSF1A/Wnt pathway, which could be targeted by miR-181α-5p and affected by nuclear factor-kappa B (NF-κB).

CONCLUSIONS

IL-1β secreted by M2-TAMs contributed to OS metastasis, which could be suppressed by knockdown of miR-181α-5p or overexpression of RASSF1A through NF-κB/miR-181α-5p/RASSF1A/Wnt pathway. These findings can guide new target discovery for drug development in OS treatment.

Wnt/β‑catenin signaling modulates piperine‑mediated antitumor effects on human osteosarcoma cells

The plant extract piperine is used as a traditional Chinese medicine due to its anti-inflammatory effects and efficacy against numerous types of cancer. The aim of the present study was to investigate the antitumor mechanism of piperine in human osteosarcoma U2OS and 143B cell lines. The effects of piperine on cell apoptosis and invasion of human osteosarcoma cells were assessed using flow cytometry and Transwell assays. Moreover, western blotting was used to measure the effects of piperine on the protein expression levels of the metastasis markers matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF). In addition, the involvement of the Wnt/β-catenin signaling pathway in modulating the effects of piperine was examined via western blot analysis. The results of MTT and Transwell invasion assays indicated that piperine treatment dose-dependently reduced U2OS and 143B cell viability and invasion. Furthermore, a significant reduction was identified in MMP-2, VEGF, glycogen synthase kinase-3β and β-catenin protein expression levels, as well as the expression levels of their target proteins cyclooxygenase-2, cyclin D1 and c-myc, in U2OS cells after piperine treatment. In addition, similar results were observed in 143B cells. Therefore, the present study demonstrated the efficacy of piperine in osteosarcoma, and identified that the Wnt/β-catenin signaling pathway may modulate the antitumor effects of piperine on human U2OS and 143B cells.

Role of Secreted Frizzled-Related Protein 1 in Early Mammary Gland Tumorigenesis and Its Regulation in Breast Microenvironment

In mice, the lack of secreted frizzled-related protein 1 (SFRP1) is responsible for mammogenesis and hyperplasia, while, in bovines, its overexpression is associated with post-lactational mammary gland involution. Interestingly, there are no reports dealing with the role of SFRP1 in female involution. However, SFRP1 dysregulation is largely associated with human tumorigenesis in the literature. Indeed, the lack of SFRP1 is associated with both tumor development and patient prognosis. Considering the increased risk of breast tumor development associated with incomplete mammary gland involution, it is crucial to demystify the "grey zone" between physiological age-related involution and tumorigenesis. In this review, we explore the functions of SFRP1 involved in the breast involution processes to understand the perturbations driven by the disappearance of SFRP1 in mammary tissue. Moreover, we question the presence of recurrent microcalcifications identified by mammography. In bone metastases from prostate primary tumor, overexpression of SFRP1 results in an osteolytic response of the tumor cells. Hence, we explore the hypothesis of an osteoblastic differentiation of mammary cells induced by the lack of SFRP1 during lobular involution, resulting in a new accumulation of hydroxyapatite crystals in the breast tissue.

Upregulation of OIP5-AS1 Predicts Poor Prognosis and Contributes to Thyroid Cancer Cell Proliferation and Migration

As a common malignancy, thyroid cancer mainly occurs in the endocrine system. There have been accumulating studies on therapeutic methods of thyroid cancer, but its internal molecular mechanism is still not fully understood. Long noncoding RNA (lncRNA) OIP5-AS1 was confirmed as an oncogene and related to poor prognosis in various cancers. Nevertheless, its role and underlying mechanism remain unclear in thyroid cancer. Here, we observed a significant upregulation of OIP5-AS1 in thyroid cancer tissues and cells, and upregulated OIP5-AS1 was correlated with poor prognosis in thyroid cancer. Moreover, OIP5-AS1 knockdown resulted in the inhibited cell proliferation and migration, while overexpressed OIP5-AS1 exhibited the reverse function in thyroid cancer. Besides, OIP5-AS1 was found to positively regulate Wnt/β-catenin signaling pathway. Through mechanism exploration, OIP5-AS1 was discovered to activate Wnt/β-catenin signaling pathway via FXR1/YY1/CTNNB1 axis. Finally, rescue assays indicated that the inhibitive role of silenced OIP5-AS1 in thyroid cancer cell growth and Wnt/β-catenin signaling pathway could be rescued by overexpression of CTNNB1 or addition of lithium chloride (LiCl). In conclusion, upregulation of OIP5-AS1 predicted unfavorable prognosis and enhanced thyroid cancer cell growth by activating Wnt/β-catenin signaling pathway.

WNT5B exerts oncogenic effects and is negatively regulated by miR-5587-3p in lung adenocarcinoma progression

WNT5B glycoprotein belongs to the Wnt protein family. Limited investigations revealed a possible role of WNT5B in malignancies, such as triple-negative breast cancer and oral squamous cell carcinoma. However, whether WNT5B contributes to the progression of lung adenocarcinoma (LAD) remains unclear. Here, we initially determine that WNT5B is highly expressed in LAD and is positively correlated with lymph node metastasis and TNM stage. Consistently, clinical analysis reveals WNT5B as an independent prognostic biomarker in LAD. Silencing WNT5B suppresses the proliferation of LAD both in vitro and in vivo by interfering G1/S cell-cycle progression and modulating amino acid metabolism, revealing its remarkable oncogenic role in LAD. Of note, we also identified miR-5587-3p as a negative upstream regulator of WNT5B in LAD, which may help develop therapies targeting LAD patients with high WNT5B expression. Taken together, our results revealed an oncogenic role of WNT5B in LAD, which could be a prognostic biomarker and promising therapeutic target for LAD patients.

Dihydrotanshinone I inhibits the growth of osteosarcoma through the Wnt/β-catenin signaling pathway

Background: Osteosarcoma is a common malignant tumor, with relatively lower survival rates in adolescents. Dihydrotanshinone I (DHI) was extracted from the traditional Chinese medicine Salvia miltiorrhiza and was shown to inhibit several types of cancer. Purpose: To explore the effect of DHI on the proliferation, migration, invasion, and apoptosis of osteosarcoma cells, as well as the possible molecular mechanism. Methods: The effect of DHI on the proliferation of osteosarcoma was detected by crystal violet assay, MTT assay, colony formation assay. The effects of DHI on the migration and invasion of osteosarcoma were detected by wound healing assays, cell migration and invasion assays. The effect of DHI on apoptosis of osteosarcoma was detected by cell apoptosis assay and Hoechst apoptosis staining. The protein expression levels were detected by Western blotting assay. The activity of Wnt/β-Catenin signaling pathway was detected by luciferase reporter assay and Western blot. The inhibitory effect of DHI on osteosarcoma in vivo was analyzed by an orthotopic OS tumor animal model and immunohistochemistry. Result: DHI may inhibit the proliferation, decrease the migration, reduce the invasion, and promote the apoptosis of osteosarcoma cells. In vivo mouse model, DHI can inhibit the formation of osteosarcoma. In terms of mechanism, DHI may inhibit both the transcriptional activity and the total protein level of β-catenin. Conclusion: DHI may inhibit the proliferation, migration, and invasion as well as induce the apoptosis of osteosarcoma cells, possibly through suppressing the Wnt/β-catenin signaling pathway.

miR-127 suppresses gastric cancer cell migration and invasion via targeting Wnt7a

Gastric cancer (GC) is a malignant tumor originating from the mucosal epithelium of the stomach. Patients suffering from this disease may have occurrence of residual GC due to delay in diagnosis and treatment. In addition, abnormal expression of microRNAs (miRNAs) is involved in GC progression. Therefore, we examined the underlying mechanism of miR-127 in GC. The expression of miR-127 and Wnt7a was examined in GC using RT-qPCR and western blot analysis. A Transwell assay was used to assess the ability of GC cell migration and invasion. Luciferase reporter assay was used to verify the specific target of miR-127 in GC. The results showed miR-127 expression was lower in GC than normal samples, while Wnt7a expression was detected at a higher level in GC than normal samples. The association between miR-127 and Wnt7a expression was negatively correlated in GC tissues. miR-127 mimic in the two GC cell lines markedly curbed cell migration and invasion, while inhibition of miR-127 showed the opposite effect. In addition, Wnt7a siRNA significantly inhibited GC cell migration and invasion and Wnt7a was verified as a specific target of miR-127 in GC cells. Wnt7a reversed the ability of GC cell migration and invasion regulated by miR-127. In conclusion, miR-127 could curb GC cell migration and invasion by upregulating Wnt7a, indicating its potential application in GC diagnosis and therapy.

Retracted Article: Long non-coding RNA KCNQ1OT1 promotes osteosarcoma progression by increasing β-catenin activity

Objective: Long non-coding RNA KCNQ1OT1 has been associated with the development of different types of cancers. The present research investigated the role of KCNQ1OT1 in osteosarcoma. Methods: Expression level of KCNQ1OT1 in osteosarcoma and paired non-cancerous tissue specimens from 56 osteosarcoma patients and its association with patients' clinicopathological features was investigated. KCNQ1OT1 overexpression and knockdown in primary-cultured osteosarcoma cells was constructed by lentiviral transduction. Influence of KCNQ1OT1 overexpression or knockdown on osteosarcoma cell growth, apoptosis, migration, invasion, epithelial-to-mesenchymal transition and beta-catenin activation was investigated. Results: Expression of KCNQ1OT1 in osteosarcoma tissue specimens was significantly increased in comparison to that in adjacent counterparts. High expression of KCNQ1OT1 significantly associated with osteosarcoma progression and patients' decreased survival. Overexpression of KCNQ1OT1 significantly increased osteosarcoma cell growth, proliferation, migration, invasion, epithelial-to-mesenchymal transition and beta-catenin activation while reducing cell apoptosis in vitro, and KCNQ1OT1 knockdown showed opposite effects. Inhibition of beta-catenin/TCF activity by ICG-001 treatment significantly attenuated the promoting effect of KCNQ1OT1 overexpression on osteosarcoma cell malignancy described above. Conclusion: KCNQ1OT1 might be a potential prognostic factor in osteosarcoma. High expression of KCNQ1OT1 might promote osteosarcoma development by increasing the activation of WNT/beta-catenin signaling pathway.

Variants in the 14q32 miRNA cluster are associated with osteosarcoma risk in the Spanish population

Association studies in osteosarcoma risk found significant results in intergenic regions, suggesting that regions which do not codify for proteins could play an important role. The deregulation of microRNAs (miRNAs) has been already associated with osteosarcoma. Consequently, genetic variants affecting miRNA function could be associated with risk. This study aimed to evaluate the involvement of all genetic variants in pre-miRNAs described so far in relationship to the risk of osteosarcoma. We analyzed a total of 213 genetic variants in 206 pre-miRNAs in two cohorts of osteosarcoma patients (n = 100) and their corresponding controls (n = 256) from Spanish and Slovenian populations, using Goldengate Veracode technology (Illumina). Four polymorphisms in pre-miRNAs at 14q32 miRNA cluster were associated with osteosarcoma risk in the Spanish population (rs12894467, rs61992671, rs58834075 and rs12879262). Pathway enrichment analysis including target genes of these miRNAs pointed out the WNT signaling pathways overrepresented. Moreover, different single nucleotide polymorphism (SNP) effects between the two populations included were observed, suggesting the existence of population differences. In conclusion, 14q32 miRNA cluster seems to be a hotspot for osteosarcoma susceptibility in the Spanish population, but not in the Slovenian, which supports the idea of the existence of population differences in developing this disease.

DACH1 inhibits glioma invasion and tumor growth via the Wnt/catenin pathway

Background/aim

Glioma is the most common and malignant nervous system tumor and is associated with high-grade malignancy and high recurrence. The mammalian Dachshund1 (DACH1) is a recognized anti-tumor site and has low expression in several malignant tumors, including glioma. We designed and conducted this study to further determine the mechanism of DACH1 in glioma.

Patients and methods

The data collected from specimens of patients with glioma from GSE16011 and REMBRANDT databases were analyzed. The effect of DACH1 on proliferation, migration, and invasion of U87 and U251 cell lines was analyzed in vitro. The symbol targets of the Wnt/β-catenin pathway were also evaluated through Western blot.

Results

DACH1 deficiency was found in glioma tissues, and the DACH1 level was negatively correlated with the tumor malignancy. DACH1 overexpression inhibited the tumor proliferation, migration, and invasion. High expression of DACH1 also dampened the Wnt/β-catenin pathway, and the activation of the Wnt/β-catenin pathway partly led to the limited proliferation in glioma cells.

Conclusion

Downregulation of DACH1 was related to the malignancy and poor prognosis of patients with glioma, and DACH1 overexpression inhibited the tumor proliferation via the Wnt/β-catenin pathway. These findings might assist in the discovery of novel potential diagnostic and therapeutic targets for DACH1, thereby reducing the malignancy and recurrence of glioma.

Wnt signaling in cervical cancer?

Cervical cancer (CC) is the second most common malignant cancer in women. CC is difficult to diagnose, has a high recurrence rate, and is resistant to systemic therapies; as a result, CC patients have a relatively poor prognosis. One potential link to CC is the Wnt signaling pathway and its downstream effectors, which regulate cell differentiation, proliferation, migration, and fate. The aberrant activation of Wnt signaling is associated with various cancers, including CC. Recent studies have shown that activating or inhibiting the intracellular signal transduction in this pathway can regulate cancer cell growth and viability. This review will summarize the experimental evidence supporting the significance of the Wnt signaling pathway in CC, and will also discuss the current clinical role of Wnt signaling in CC diagnosis, therapy, and prognosis.

Effects of three-dimensional collagen scaffolds on the expression profiles and biological functions of glioma cells

Three-dimensional (3D) culture has been increasingly used to investigate tumor cell biology for improved simulation of the natural developing environment. However, the way in which 3D culture affects the gene expression and biological functions of glioma cells remains to be fully elucidated. In the present study, 3D culture environments were established using collagen scaffolds with different pore sizes, followed by the comparison of gene expression profiles and associated biological functions of glioma cells, including the U87, U251 and HS683 cell lines, in 3D collagen scaffolds with conventional two-dimensional (2D) cultured cells. Finally, the possible signaling pathways regulating these differences were investigated. It was found that the 3D collagen scaffold culture upregulated the expression of genes associated with stemness, cell cycle, apoptosis, epithelia-mesenchymal transition, migration, invasion and glioma malignancy, and induced the corresponding functional changes. Apoptotic pathways, the Wnt pathway, Sonic Hedgehog pathway and Notch pathway, may be involved in the regulation of these changes. The aperture size of the collagen-scaffold did not appear to affect the gene expression or functions of the glioma cells. The results of the study suggested that the 3D collagen scaffold enhanced the malignancy of glioma cells and may be a promising in vitro platform for investigations of glioma.

Antitumor activity of resveratrol against human osteosarcoma cells: a key role of Cx43 and Wnt/β-catenin signaling pathway

Osteosarcoma is a high-grade bone sarcoma with strong invasive ability. However, treatment with traditional chemotherapeutic drugs is limited by low tolerability and side effects. Resveratrol has been reported previously to have selective antitumor effect on various tumor cells while little is known about its effects and underlying mechanism in osteosarcoma biology. In this study, we found that resveratrol inhibits proliferation and glycolysis, induces apoptosis and reduces the invasiveness of U2-OS cells in vitro. After treatment with resveratrol, the expression of related Wnt/β-catenin signaling pathway target genes, such as β-catenin, c-myc, cyclin D1, MMP-2 and MMP-9, was downregulated and an increased E-cadherin level was observed as well. Additionally, the dual luciferase assay results also indicated that resveratrol suppressed the activity of Wnt/β-catenin signaling pathway. Interestingly, we noticed that the expression of connexin 43 (Cx43) increased with the prolongation of resveratrol treatment time. To further investigate the relationship between Cx43 and the Wnt/β-catenin signaling pathway in osteosarcoma, we used lentiviral-mediated shRNA to knockdown the expression of Cx43. Knockdown of Cx43 activated the Wnt/β-catenin signaling pathway, promoted proliferation and invasion, and inhibited apoptosis of U2-OS cells. Taken together, our results demonstrate that the antitumor activity of resveratrol against U2-OS cells in vitro occurs through up-regulating Cx43 and E-cadherin, and suppressing the Wnt/β-catenin signaling pathway. Moreover, Cx43 expression is negatively related to the activity of the Wnt/β-catenin pathway in U2-OS cells.

Resveratrol in management of bone and spinal cancers

Bone cancer is a malignant primary tumour of the bone with different typing, such as, osteosarcoma, chondrosarcoma, Ewing's sarcoma and fibrosarcoma. Despite the clinical efficacy of conventional therapies of bone cancer, most patients eventually relapse and the disease remains incurable. Therefore, new therapeutic strategies are needed to improve patient outcome. In this review article, we have discussed the role of resveratrol in preventing bone and spinal cancers and therapeutics. Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural polyphenol, which has been widely reported as an anticancer molecule. Resveratrol exhibits multiple tumour-suppressing activities in bone cancer by affecting a series of critical events. It has the protective effects against oxidative injury, possesses antiproliferative activity and induces apoptosis in cancer cells. Resveratrol might be a good option for the treatment of different types of bone and spinal cancers.

Baicalein inhibits progression of osteosarcoma cells through inactivation of the Wnt/β-catenin signaling pathway

Osteosarcoma is a very common type of malignant bone tumor in children and young adults and aberrant activation of Wnt/β-catenin signaling pathway has been discovered in osteosarcoma. The traditional Chinese medicine baicalein was proved to have anti-proliferative and anti-metastatic properties in osteosarcoma, but the mechanism remained poorly understood. In the present study, we assessed the effects of baicalein on osteosarcoma and detected the potential molecular mechanism. We found that baicalein significantly suppressed the proliferation of osteosarcoma cells in a concentration- and time-dependent manner. In additional, baicalein could induce apoptosis and cell cycle arrest and reduce cell motility. Moreover, the level of β-catenin and its target genes, including c-myc, cyclinD1, and survivin significantly decreased in baicalein-treated osteosarcoma cells, whereas exogenous expression of β-catenin could reverse the anti-proliferative and anti-metastatic effects of baicalein. Subsequently, we established a 143B xenograft tumor model and found that baicalein treatment significantly inhibited tumor growth accompanied with inhibiting Wnt/β-catenin pathway. Thus, these findings suggest that baicalein may be a potentially effective Chinese herbal medicine for therapeutics of osteosarcoma and Wnt/β-catenin signaling pathway may serve as an efficient molecular marker or predictive target for osteosarcoma.

MicroRNA profiling and bioinformatics analyses reveal the potential roles of microRNAs in chordoma

Chordoma is a rare aggressive bone tumor arising from remnants of the notochord, and patients with chordoma have a poor prognosis. However, the unique expression profiles of microRNAs (miRNAs/miRs) and their downstream signaling pathways in chordoma remain incompletely characterized. The aim of the present study was to delineate the global miRNA expression profile and associated signaling networks in chordoma. miRNA profiling was performed on chordoma and fetal notochord tissues. Differentially expressed miRNAs in chordoma were analyzed using microarrays with hierarchical clustering analysis. The target genes of the differentially expressed miRNAs were predicted, and Gene Ontology (GO) and pathway analyses were performed for the intersecting genes. A total of 42 miRNAs were significantly dysregulated in chordoma compared with that in fetal nucleus pulposus tissues. The expression of hsa-miR-21-3p, hsa-miR-150-5p, hsa-miR-1290 and hsa-miR-623 were validated using the reverse transcription-quantitative polymerase chain reaction. On the basis of the intersection predicted by three databases (Targetscan, microRNA.org and PITA), 10,292 potential miRNA targets were identified. Bioinformatic analyses suggested that these dysregulated miRNAs and their predicted targets were functions of signaling pathways in cancer, the mitogen-activated protein kinase signaling pathway, regulation of actin cytoskeleton, focal adhesion and endocytosis. In particular, human (hsa-)miR-185-5p was identified as a crucial miRNA in chordoma development via the Wnt signaling pathway. The results of the present study provide a comprehensive expression and functional profile of differentially expressed miRNAs associated with chordoma. This profile may serve as a potential tool for biomarker and therapeutic target identification in patients with chordoma.

Transcriptional regulation of Runx2 by HSP90 controls osteosarcoma apoptosis via the AKT/GSK-3β/β-catenin signaling

Osteosarcoma (OS) is the most malignant primary bone tumor in children and adolescents with limited treatment options and poor prognosis. Recently, aberrant expression of Runx2 has been found in OS, thereby contributing to the development, and progression of OS. However, the upstream signaling molecules that regulate its expression in OS remain largely unknown. In the present study, we first confirmed that the inhibition of HSP90 with 17-AAG caused significant apoptosis of OS cells via a caspase-3-dependent mechanism, and that inhibition or knockdown of HSP90 by 17-AAG or siRNAs significantly suppressed mRNA and protein expression of Runx2. Furthermore, we provided evidence that Runx2 was transcriptionally regulated by HSP90 when using MG132 and CHX chase assay. We also demonstrated that β-catenin was overexpressed in OS tissue, and that knockdown of β-catenin induced pronounced apoptosis of OS cells in the presence or absence of 17-AAG. Interestingly, this phenomenon was accompanied with a significant reduction of Runx2 and Cyclin D1 expression, indicating an essential role of Runx2/Cyclin D1 in 17-AAG-induced cells apoptosis. Moreover, we demonstrated that the apoptosis of OS cells induced by 17-AAG did require the involvement of the AKT/GSK-3β/β-catenin signaling pathway by using pharmacological inhibitor GSK-3β (LiCl) or siGSK-3β. Our findings reveal a novel mechanism that Runx2 is transcriptionally regulated by HSP90 via the AKT/GSK-3β/β-catenin signaling pathway, and by which leads to apoptosis of OS cells.

Oridonin synergizes with Nutlin-3 in osteosarcoma cells by modulating the levels of multiple Bcl-2 family proteins

The small-molecule inhibitors of p53-murine double minute 2 interaction, such as Nutlin-3, are effective against cancers bearing wild-type p53. However, murine double minute 2 inhibitors often are unable to completely eliminate solid tumor cells. To address this issue, we investigated the anticancer effects of Nutlin-3 in combination with Oridonin in osteosarcoma cells. We found that Oridonin at sub-toxic concentrations synergistically enhanced Nutlin-3-mediated cell viability inhibition in wild-type p53 U2OS and SJSA-1, but not in p53-mutant MNNG/HOS and in null-p53 Saos-2 osteosarcoma cell lines. Importantly, in the presence of Oridonin, Nutlin-3 could completely abolish cell viability in the wild-type p53 osteosarcoma cell lines. Western blotting analysis showed that Oridonin treatment rapidly and distinctly increased the levels of all three forms of Bim and also markedly reduced the levels of Bcl-2 and Bcl-xl in osteosarcoma cells. Western blotting analysis further showed that Oridonin considerably enhanced Nutlin-3-triggered activation of caspases-9 and -3 and poly(ADP-ribose) polymerase cleavage. Flow cytometry assay showed that Oridonin significantly enhanced Nutlin-3-mediated apoptosis in wild-type p53 osteosarcoma cells. Overall, our results suggest that the combined treatment of Nutlin-3 plus Oridonin may offer a novel therapeutic strategy for osteosarcoma.

Controlled Release of Naringin in Metal-Organic Framework-Loaded Mineralized Collagen Coating to Simultaneously Enhance Osseointegration and Antibacterial Activity

Two important goals in orthopedic implant research are to promote osseointegration and prevent infection. However, much previous effort has been focused on the design of coatings to either enhance osseointegration while ignoring antibacterial activity or vice versa, to prevent infection while ignoring bone integration. Here, we designed a multifunctional mineralized collagen coating on titanium with the aid of metal-organic framework (MOF) nanocrystals to control the release of naringin, a Chinese herbal medicine that could promote osseointegration and prevent bacterial infection. The attachment, proliferation, osteogenic differentiation, and mineralization of mesenchymal stem cells on the coating were significantly enhanced. Meanwhile, the antibacterial abilities against Staphylococcus aureus were also promoted. Furthermore, release kinetics analysis indicated that the synergistic effect of a primary burst release stage and secondary slow release stage played a critical role in the performance and could be controlled by the relative concentrations of MOF and naringin. This work thus provides a novel strategy to engineer multifunctional orthopedic coatings that can enhance osseointegration and simultaneously inhibit microbial cell growth.

Wnt inhibitory factor 1 (WIF1) methylation and its association with clinical prognosis in patients with chondrosarcoma

Chondrosarcoma (CS) is a rare cancer, but it is the second most common primary malignant bone tumor and highly resistant to conventional chemotherapy and radiotherapy. Aberrant DNA methylation in the promoter CpG island of Wnt inhibitory factor 1 (WIF1) has been observed in different cancers. However, no studies have shown the relationship between WIF1 methylation and CS. In this study, we found promoter methylated WIF1 in both CS cell lines (CS-1 and SW1353) and tumor tissues. Western blot analysis confirmed loss WIF1 expression and activation of Wnt pathway proteins (Wnt5a/b, LRP6, and Dvl2). We subsequently examined the correlation between levels of WIF1 methylation and overall survival (OS) and progression-free survival (PFS) in CS patient samples with a follow-up spanning 234 months (mean: 57.6 months). Kaplan-Meier survival curves and log-rank tests revealed that high levels of WIF1 methylation were associated with lower OS and PFS rates (p < 0.05). Multivariate Cox hazard analysis suggested that detection of high level methylation of WIF1 could be an independent prognostic factor in OS and PFS. In conclusion, we found that WIF1 is epigenetically silenced via promoter DNA methylation in CS and propose that WIF1 methylation may serve as a potential prognostic marker for patients with CS.

Signal Transductions of BEAS-2B Cells in Response to Carcinogenic PM2.5 Exposure Based on a Microfluidic System

PM_2.5 (particulate matter less than 2.5 μm in diameter) is considered as a harmful carcinogen. Determining the precise relationship between the chemical constituents of PM_2.5 in the air and cancer progression could aid the treatment of environment related disease and establishing risk reduction strategies. Herein, we used transcriptomics (RNA-seq) and an integrated microfluidic system to identify the global gene expression and differential target proteins expression induced by ambient fine particles collected from the heavy haze in China. The results clearly indicated that cancer related pathways exhibited the strongest dysregulation. The ambient fine particles could be uptaken into the cells by pinocytosis, mainly promoting the PI3K-Akt pathway, FGF/FGFR/MAPK/VEGF signaling, and the JAK-STAT pathway, leading to evading apoptosis, sustained angiogenesis, and cell proliferation, which are the most important hallmarks of cancer. And fine particles also have been demonstrated to create intracellular reactive oxygen species (ROS) and mitochondrial ROS, change intracellular free Ca²⁺, and induce apoptosis, which are all key players in mediating cancer progression. It was observed by transmission electron microscopy (TEM) that the particles from the haze could enter the mitochondria, resulting in disturbance of the mitochondrial membrane and disruption of the mitochondria, and these particles can even enter inside the nucleus. It was also found in our study of organics (OC, PAHs) and metals (Zn, As, V) that compounds of fine particles were more closely associated with the exacerbation of cancer and secondary aerosols generated by traffic had the largest impact on cancer related signal transductions.

LDOC1 regulates Wnt5a expression and osteosarcoma cell metastasis and is correlated with the survival of osteosarcoma patients

Osteosarcomas are common bone malignancies in children and adolescents. LDOC1 (leucine zipper, down-regulated in cancer 1), a tumor suppressor, is down-regulated in many cancers. In this study, we investigated the role of LDOC1 in tumor metastasis and its prognostic significance in osteosarcomas. We established osteosarcoma cells stably expressing LDOC1, driven by an HIV-based lentiviral system. We investigated the impact of LDOC1 on migration and invasion abilities in these cells using a transwell assay. LDOC1-associated changes in expression of metastasis-promoting genes were analyzed with a quantitative real-time polymerase chain reaction primer array. A xenograft tumor model (n = 7 mice/group) was used to assess the effect of LDOC1 on osteosarcoma metastasis in vivo. The overall survival and disease-free survival of osteosarcoma patients (n = 74) were analyzed retrospectively based on immunohistochemical analysis of LDOC1 levels in tumors and Kaplan-Meier analysis. LDOC1-expressing osteosarcoma cells displayed decreased migration and invasion in vitro. The quantitative real-time polymerase chain reaction primer array data showed that increased LDOC1 expression up-regulated many metastasis-suppressor genes. In the xenograft model, micro-computed tomography imaging data indicated that increased LDOC1 expression is associated with weaker lung metastasis ability. The Wnt5a signaling pathway promotes osteosarcoma metastasis; LDOC1 expression decreased Wnt5a levels in osteosarcoma cells. Kaplan-Meier analysis showed that higher LDOC1 expression was associated with improved osteosarcoma patient overall survival and disease free survival (p = 0.022). Our data show that LDOC1 is a tumor suppressor in osteosarcoma, and that it regulates metastasis of osteosarcoma cells. Furthermore, LDOC1 might be a valuable prognostic marker in osteosarcomas.

MicroRNA-133b Inhibits Cell Proliferation and Invasion in Osteosarcoma by Targeting Sirt1

MicroRNAs are a class of small noncoding RNAs that function as critical gene regulators through targeting mRNAs for translational repression or degradation. In this study, we showed that the miR-133b expression level was decreased while the Sirt1 mRNA expression level was increased in osteosarcoma tissue and cell lines. A low expression of miR-133b was significantly associated with tumor size, distant metastasis, and advanced clinical stage. In addition, osteosarcoma patients with a low miR-133b expression showed a worse prognosis when compared to those with a high level of miR-133b expression. Thus, we identified Sirt1 as a novel direct target of miR-133b. Overexpression of miR-133b suppressed Sirt1 expression and attenuated cell proliferation and invasion. Forced expression of Sirt1 could partly rescue the inhibitory effect of miR-133b in osteosarcoma cells. Our finding also suggested that the inhibitory effects of the miR-133b/Sirt1 axis on osteosarcoma progression were involved in the Wnt/β-catenin pathway. Taken together, these findings will shed light on the role and mechanism of miR-133b in regulating osteosarcoma cell growth via the miR-133b/Sirt1 axis, and miR-133b may serve as a potential therapeutic target in osteosarcoma in the future.

Silencing Transmembrane Protein 45B (TNEM45B) Inhibits Proliferation, Invasion, and Tumorigenesis in Osteosarcoma Cells

Transmembrane protein 45B (TMEM45B) is a member of the TMEM family of proteins and has been reported to be expressed abnormally in different kinds of human tumors. However, the biological function of TMEM45B in osteosarcoma remains unclear. The objective of this study was to investigate the role of TMEM45B in regulating the biological behavior of osteosarcoma cells. Our results demonstrated that the expression of TMEM45B at both the protein and mRNA levels was dramatically upregulated in human osteosarcoma cell lines. Knockdown of TMEM45B significantly suppressed the proliferation, migration, and invasion of U2OS cells in vitro. Mechanistically, knockdown of TMEM45B sharply downregulated the expression level of β-catenin, cyclin D1, and c-Myc in U2OS cells. Finally, knockdown of TMEM45B attenuated tumor growth in transplanted U2OS-derived tumors in nude mice. Taken together, our results demonstrated that TMEM45B plays an important role in regulating the proliferation, migration, and invasion of osteosarcoma cells and that its effects on proliferation and invasion were mediated partially through the Wnt/β-catenin signaling pathway. These observations support our belief that TMEM45B may serve as an oncogene in the development and progression of osteosarcoma.

Ursolic acid inhibits proliferation and induces apoptosis by inactivating Wnt/β-catenin signaling in human osteosarcoma cells

Although multiple chemotherapeutic agents have been used for osteosarcoma (OS) treatment, their mechanisms need further study. Ursolic acid (UA), a pentacyclic triterpenoid, can reduce cell proliferation and induce apoptosis in various cancer cells, such as OS. However, the exact mechanism underlying this function remains unclear. In this study, we investigated the anti‑proliferative effect of UA in human OS 143B cells and dissected the possible molecular mechanism underlying this effect. We demonstrated that UA can reduce cell proliferation, induce apoptosis and arrest cell cycle in 143B cells, as well as inhibit OS tumor growth in a mouse xenograft model. Using a luciferase reporter assay, we found that the Wnt/β‑catenin signaling is inhibited by UA in 143B cells. Correspondingly, the expression level and nuclear translocation of β‑catenin are both decreased by UA. Exogenous expression of β‑catenin attenuates the anticancer effect of UA in 143B cells, while knockdown of β‑catenin enhances this effect. UA increases the expression level of p53 in a concentration‑dependent manner, and inhibition of p53 reduces the anticancer effect of UA in 143B cells. Moreover, inhibition of p53 partly reverses the UA‑induced downregulation of β‑catenin, as do the targets of Wnt/β‑catenin signaling, such as c‑Myc and cyclin D1. Our findings indicated that UA can inhibit the proliferation of 143B OS cells through inactivation of Wnt/β-catenin signaling, which may be mediated partly by upregulating the expression of p53.

The role and mechanism of CRL4 E3 ubiquitin ligase in cancer and its potential therapy implications

CRLs (Cullin-RING E3 ubiquitin ligases) are the largest E3 ligase family in eukaryotes, which ubiquitinate a wide range of substrates involved in cell cycle regulation, signal transduction, transcriptional regulation, DNA damage response, genomic integrity, tumor suppression and embryonic development. CRL4 E3 ubiquitin ligase, as one member of CRLs family, consists of a RING finger domain protein, cullin4 (CUL4) scaffold protein and DDB1–CUL4 associated substrate receptors. The CUL4 subfamily includes two members, CUL4A and CUL4B, which share extensively sequence identity and functional redundancy. Aberrant expression of CUL4 has been found in a majority of tumors. Given the significance of CUL4 in cancer, understanding its detailed aspects of pathogenesis of human malignancy would have significant value for the treatment of cancer. Here, the work provides an overview to address the role of CRL4 E3 ubiquitin ligase in cancer development and progression, and discuss the possible mechanisms of CRL4 ligase involving in many cellular processes associated with tumor. Finally, we discuss its potential value in cancer therapy.

miR-200c and phospho-AKT as prognostic factors and mediators of osteosarcoma progression and lung metastasis

Lung metastasis is the major cause of death in osteosarcoma patients. However, molecular mechanisms underlying this metastasis remain poorly understood. To identify key molecules related with pulmonary metastasis of pediatric osteosarcomas, we analyzed high-throughput miRNA expression in a cohort of 11 primary tumors and 15 lung metastases. Results were further validated with an independent cohort of 10 primary tumors and 6 metastases. In parallel, we performed immunohistochemical analysis of activated signaling pathways in 36 primary osteosarcomas. Only phospho-AKT associated with lower overall survival in primary tumors, supporting its role in osteosarcoma progression. CTNNB1 expression also associated with lower overall survival but was not strong enough to be considered an independent variable. Interestingly, miR-200c was overexpressed in lung metastases, implicating an inhibitory feed-back loop to PI3K-AKT. Moreover, transfection of miR200c-mimic in U2-OS cells reduced phospho-AKT levels but increased cellular migration and proliferation. Notably, miR-200c expression strongly correlated with miR-141 and with the osteogenic inhibitor miR-375, all implicated in epithelial to mesenchymal transition. These findings contrast epithelial tumors where reduced miR-200c expression promotes metastasis. Indeed, we noted that osteosarcoma cells in the lung also expressed the epithelial marker CDH1, revealing a change in their mesenchymal phenotype. We propose that miR-200c upregulation occurs late in osteosarcoma progression to provide cells with an epithelial phenotype that facilitates their integration in the metastatic lung niche. Thus, our findings identify phospho-AKT in the primary tumor and miR-200c later during tumor progression as prognostic molecules and potential therapeutic targets to prevent progression and metastasis of pediatric osteosarcomas.

High Expression of XRCC6 Promotes Human Osteosarcoma Cell Proliferation through the β-Catenin/Wnt Signaling Pathway and Is Associated with Poor Prognosis

Increasing evidences show that XRCC6 (X-ray repair complementing defective repair in Chinese hamster cells 6) was upregulated and involved in tumor growth in several tumor types. However, the correlation of XRCC6 and human osteosarcoma (OS) is still unknown. This study was conducted with the aim to reveal the expression and biological function of XRCC6 in OS and elucidate the potential mechanism. The mRNA expression level of XRCC6 was measured in osteosarcoma cells and OS samples by quantitative transcription-PCR (qRT-PCR). The expression of XRCC6 protein was measured using Western blot and immunohistochemical staining in osteosarcoma cell lines and patient samples. Cell Counting Kit 8 (CCK8), colony-forming and cell cycle assays were used to test cell survival capacity. We found that XRCC6 was overexpressed in OS cells and OS samples compared with the adjacent non-tumorous samples. High expression of XRCC6 was correlated with clinical stage and tumor size in OS. Reduced expression of XRCC6 inhibits OS cell proliferation through G2/M phase arrest. Most importantly, further experiments demonstrated that XRCC6 might regulate OS growth through the β-catenin/Wnt signaling pathway. In conclusion, these findings indicate that XRCC6 exerts tumor-promoting effects for OS through β-catenin/Wnt signaling pathway. XRCC6 may serve as a novel therapeutic target for OS patients.