Molecular Chaperones in Osteosarcoma: Diagnosis and Therapeutic Issues

HSPD1 Supports Osteosarcoma Progression through Stabilizing ATP5A1 and thus Activation of AKT/mTOR Signaling

Malignant transformation is concomitant with excessive activation of stress response pathways. Heat shock proteins (HSPs) are stress-inducible proteins that play a role in folding and processing proteins, contributing to the non-oncogene addiction of stressed tumor cells. However, the detailed role of the HSP family in osteosarcoma has not been investigated. Bulk and single-cell transcriptomic data from the GEO and TARGET databases were used to identify HSPs associated with prognosis in osteosarcoma patients. The expression level of HSPD1 was markedly increased in osteosarcoma, correlating with a negative prognosis. Through in vitro and in vivo experiments, we systematically identified HSPD1 as an important contributor to the regulation of proliferation, metastasis, and apoptosis in osteosarcoma by promoting the epithelial-mesenchymal transition (EMT) and activating AKT/mTOR signaling. Subsequently, ATP5A1 was determined as a potential target of HSPD1 using immunoprecipitation followed by mass spectrometry. Mechanistically, HSPD1 may interact with ATP5A1 to reduce the K48-linked ubiquitination and degradation of ATP5A1, which ultimately activates the AKT/mTOR pathway to ensure osteosarcoma progression and EMT process. These findings expand the potential mechanisms by which HSPD1 exerts biological effects and provide strong evidence for its inclusion as a potential therapeutic target in osteosarcoma.

KNTC1 knockdown inhibits the proliferation and migration of osteosarcoma cells by MCM2

Osteosarcoma (OS) is a common primary malignant bone tumor, and it is necessary to further investigate the molecular mechanism of OS progression. The expression of kinetochore associated protein 1 (KNTC1) and minichromosome maintenance 2 (MCM2) was detected by immunohistochemistry, quantitative PCR (qPCR) and Western blot. Gene knockdown or overexpression cell models were constructed and the proliferation, apoptosis, cell cycle and migration were detected in vitro, besides, xenograft models were established to explore the effects of KNTC1 downregulation in vivo. Public databased and bioinformatics analysis were performed to screen the downstream molecules and determine the expression of MCM2 in cancers. KNTC1 was overexpressed in OS tissues and positively correlated with overall survival of OS patients. KNTC1 knockdown inhibited the proliferation and migration, and arrested G2 phase, and induced apoptosis. Besides, KNTC1 downregulation restricted the xenograft tumor formation. MCM2, one of the coexpressed genes, was highly expressed in sarcoma and downregulated after KNTC1 knockdown. MCM2 overexpression heightened the proliferation and migration ability of OS cells, which was reversed the inhibiting effects of KNTC1 knockdown. KNTC1 was overexpressed in OS and promoted the progression of OS by upregulating MCM2.

M7G modification of FTH1 and pri-miR-26a regulates ferroptosis and chemotherapy resistance in osteosarcoma

Doxorubicin and platinum are widely used in the frontline treatment of osteosarcoma, but resistance to chemotherapy limits its curative effect. Here, we have identified that METTL1 mediated N7-Methyladenosine (m7G) low expressed in osteosarcoma tissues, plays a critical oncogenic role, and enhances osteosarcoma chemosensitivity in osteosarcoma. Mechanistically, AlkAniline-Seq data revealed that Ferritin heavy chain (FTH1), the main component of ferritin, which is crucial for iron homeostasis and the inhibition of lipid peroxidation, is one of the top 10 genes with the most significant change in m7G methylation sites mediated by METTL1 in human osteosarcoma cells. Interestingly, METTL1 significantly increased the expression of FTH1 at the mRNA level but was remarkably suppressed at the protein level. We then identified primary (pri)-miR-26a and pri-miR-98 in the Top 20 m7G-methylated pri-miRNAs with highly conserved species. Further results confirmed that METTL1 enhances cell ferroptosis by targeting FTH1 and primary (pri)-miR-26a, promoting their maturity by enhancing RNA stability dependent on m7G methylation. The increase of mature miR-26a-5p that resulted from METTL1 overexpression could further target FTH1 mRNA and eliminate FTH1 translation efficiency. Moreover, the reduction of FTH1 translation dramatically increases cell ferroptosis and promotes the sensitivity of osteosarcoma cells to chemotherapy drugs. Collectively, our study demonstrates the METTL1/pri-miR-26a/FTH1 axis signaling in osteosarcoma and highlights the functional importance of METTL1 and m7G methylation in the progression and chemotherapy resistance of osteosarcoma, suggesting that reprogramming RNA m7G methylation as a potential and promising strategy for osteosarcoma treatment.

SLC9A2, suppressing by the transcription suppressor ETS1, restrains growth and invasion of osteosarcoma via inhibition of aerobic glycolysis

Recent studies have shown that Solute Carrier Family 9 Member A2 (SLC9A2) could serve as a biomarker for cancer. However, its mechanism of action in osteosarcoma (OS) was still unclear. In this study, the data sets GSE154530 and GSE99671 were downloaded from the Gene Expression Omnibus (GEO) database, and 31 differentially expressed genes (DEGs) related to methylation were screened by bioinformatics analysis tools. Subsequently, SLC9A2 was screened as a candidate gene from DEGs, which was significantly downregulated in OS. CCK-8, transwell, western blotting and Seahorse XFe24 Cell Metabolic Analyzer assays demonstrated that overexpression of SLC9A2 could constrain OS cell proliferation, invasion, and aerobic glycolysis. Dual-luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) assays indicated ETS proto-oncogene 1 (ETS1) was a transcription suppressor of SLC9A2, and overexpression of ETS1 could promote methylation levels in specific regions of the SLC9A2 promoter. ETS1 could promote the proliferation, invasion, and aerobic glycolysis ability of OS cells, as well as tumor growth in vivo by inhibiting the expression of SLC9A2. In addition, SLC9A2, suppressing by ETS1, restrains growth and invasion of OS via inhibition of aerobic glycolysis. Thus, SLC9A2 can function as a key inhibitory factor in the aerobic glycolysis to inhibit proliferation and invasion of OS. This indicated that SLC9A2 has a potential targeted therapeutic effect on OS.

Overexpression of HSPB6 inhibits osteosarcoma progress through the ERK signaling pathway

Heat shock protein B6 (HSPB6) plays a certain role in the formation of several cancers, whereas its effect on osteosarcoma remains unclear. In this study, the effect of HSPB6 on osteosarcoma was validated through numerous experiments. HSPB6 was down-regulated in osteosarcoma. As indicated by the result of CCK-8 and colony formation assays, HSPB6 overexpression was likely to inhibit the osteosarcoma cells proliferation, whereas the flow cytometry analysis suggested that apoptosis of osteosarcoma cells was increased after HSPB6 overexpression. Furthermore, transwell and wound healing assays suggested that when HSPB6 was overexpressed, osteosarcoma cells migration and invasion were declined. Moreover, the western blotting assay suggested that the protein level of p-ERK1/2 was down-regulated in osteosarcoma when HSPB6 was overexpressed. Besides, the effect of HSPB6 on osteosarcoma in vivo was examined. As indicated by the result, HSPB6 overexpression was likely to prevent osteosarcoma growth and lung metastasis in vivo. As revealed by the findings of this study, HSPB6 overexpression exerted anticancer effects in osteosarcoma through the ERK signaling pathway and HSPB6 may be suitable target for osteosarcoma molecular therapies.

MicroRNAs as the pivotal regulators of cisplatin resistance in osteosarcoma

Osteosarcoma (OS) is an aggressive bone tumor that originates from mesenchymal cells. It is considered as the eighth most frequent childhood cancer that mainly affects the tibia and femur among the teenagers and young adults. OS can be usually diagnosed by a combination of MRI and surgical biopsy. The intra-arterial cisplatin (CDDP) and Adriamycin is one of the methods of choices for the OS treatment. CDDP induces tumor cell death by disturbing the DNA replication. Although, CDDP has a critical role in improving the clinical complication in OS patients, a high ratio of CDDP resistance is observed among these patients. Prolonged CDDP administrations have also serious side effects in normal tissues and organs. Therefore, the molecular mechanisms of CDDP resistance should be clarified to define the novel therapeutic modalities in OS. Multidrug resistance (MDR) can be caused by various cellular and molecular processes such as drug efflux, detoxification, and signaling pathways. MicroRNAs (miRNAs) are the key regulators of CDDP response by the post transcriptional regulation of target genes involved in MDR. In the present review we have discussed all of the miRNAs associated with CDDP response in OS cells. It was observed that the majority of reported miRNAs increased CDDP sensitivity in OS cells through the regulation of signaling pathways, apoptosis, transporters, and autophagy. This review highlights the miRNAs as reliable non-invasive markers for the prediction of CDDP response in OS patients.

Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies

Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.

NOTCH Signaling in Osteosarcoma

The combination of neoadjuvant chemotherapy and surgery has been promoted for the treatment of osteosarcoma; however, the local recurrence and lung metastasis rates remain high. Therefore, it is crucial to explore new therapeutic targets and strategies that are more effective. The NOTCH pathway is not only involved in normal embryonic development but also plays an important role in the development of cancers. The expression level and signaling functional status of the NOTCH pathway vary in different histological types of cancer as well as in the same type of cancer from different patients, reflecting the distinct roles of the Notch pathway in tumorigenesis. Studies have reported abnormal activation of the NOTCH signaling pathway in most clinical specimens of osteosarcoma, which is closely related to a poor prognosis. Similarly, studies have reported that NOTCH signaling affected the biological behavior of osteosarcoma through various molecular mechanisms. NOTCH-targeted therapy has shown potential for the treatment of osteosarcoma in clinical research. After the introduction of the composition and biological functions of the NOTCH signaling pathway, the review paper discussed the clinical significance of dysfunction in osteosarcoma. Then the paper reviewed the recent relevant research progress made both in the cell lines and in the animal models of osteosarcoma. Finally, the paper explored the potential of the clinical application of NOTCH-targeted therapy for the treatment of osteosarcoma.

Construction of a novel mRNAsi-related risk model for predicting prognosis and immunotherapy response in osteosarcoma

Background

Targeting cancer stem cells (CSC) may represent a future therapeutic direction for osteosarcoma (OS), which mainly relies on the identification of CSC markers. This study aimed to classify OS based on messenger ribonucleic acid (mRNA) stemness indices (mRNAsi) and construct a mRNAsi-related risk model to predict the prognosis of OS.

Methods

The one-class logistic regression (OCLR) algorithm was applied to the RNA- sequencing (seq) data of human embryonic stem cells (hESC) and induced pluripotent stem cell (iPSC) lines to calculate mRNAsi. Weighted gene co-expression network analysis (WGCNA) was performed on data obtained from the TARGET database to screen the mRNAsi-related genes. Univariate Cox regression analysis was implemented to screen mRNAsi-related genes with prognostic significance for consensus clustering of OS. The least absolute shrinkage and selection operator (LASSO) and COX regression analysis were conducted to construct a risk model based on mRNAsi-related genes.

Results

Six gene modules were identified in the TARGET database. The yellow module showed the strongest negative correlation with mRNAsi and the strongest significant positive correlation with the immune score and stromal score. OS was divided into three molecular subtypes with significant survival differences based on 73 mRNAsi-related genes with prognostic value for OS. The survival rate was ranked as C3 < C1 < C2 from low to high. The levels of immune components in C2 was significantly higher than those in C1 and C3. HSD11B2, GBP1, RNF130, APBB1IP, and NPC2 in the yellow module were used as variables for building the mRNAsi-related risk model. The survival rate of the high-risk group (as defined by this model) was significantly higher than that of the low-risk group, and it had significant survival prediction ability in 28 types of cancer. In addition, the mRNAsi-related risk model was superior to the Tumor Immune Dysfunction and Exclusion (TIDE) model in predicting the prognosis and immunotherapy response in all three immunotherapy cohorts.

Conclusions

This study classified OS and constructed a mRNAsi-related risk model based on mRNAsi-related genes, which provides a potential tool for more accurate risk stratification of OS and prediction of immunotherapy response.

Bisphenol A interacts with DLGAP5 and regulates IL-6/JAK2/STAT3 signaling pathway to promote tumorigenesis and progression of osteosarcoma

OBJECTIVE

It has been suggested that Bisphenol A (BPA), a high-production-volume industrial chemical, can accelerate the development of various type of cancers. However, the effect of BPA on osteosarcoma and the underlying mechanisms are yet to be established. Therefore, in this study we tried to explore the carcinogenic effects of BPA on osteosarcoma and the underlying mechanism.

METHODS

SaOs-2 cancer cell line was used to treat with BPA at the doses of 0.1, 1, 10 μM DGLAP5 knockdown and overexpression methods were constructed by using adenovirus mediated transfection, and the functional analysis of DGLAP5 was investigated to evaluate the carcinogenic effect of BPA on osteosarcoma through DLGAP5. Xenograft and metastatic mouse model were used to evaluate in vivo experiments.

RESULTS

In this study, BPA at 10 μM promoted the proliferation, migration and invasion in vitro, and accelerate the progression and metastasis in vivo. Also, exposure to BPA was associated with poor survival of osteosarcoma in mice. In addition, we observed that BPA at 10 μM significantly increased the expression of DGLAP5 in osteosarcoma. Silencing DGLAP5 could reverse the effect of BPA on proliferation, migration and invasion. Mechanically, BPA promoted IL-6, JAK2, and STAT3 expression and promoted tumor progression in an IL-6-dependent manner through up-regulation of DLGAP5.

CONCLUSION

Our findings demonstrated that BPA could promote the proliferation, migration, invasion of osteosarcoma cells and related to poor survival in a mouse model. DLGAP5 is one of the most critical targets of BPA to act as a carcinogen through IL-6/JAK2/STAT3 signaling pathway.

Hsa_circ_0097271 Knockdown Attenuates Osteosarcoma Progression via Regulating miR-640/MCAM Pathway

Background. The dysregulation of circular RNAs (circRNAs) participates in the malignant progression of multiple cancers, including osteosarcoma (OS). However, the role of circ_0097271 in OS development remains unclear. We thus aimed at unveiling the functional role and mechanism of circ_0097271 in OS. Methods. The expressions of circ_0097271, miR-640, and MCAM in OS were analyzed by qPCR. Cell proliferation and migration were inspected by CCK-8 assay, colony formation assay, and Transwell assay. Circ_0097271’s role in vivo was assayed by establishing animal models. The predicted binding relationship between miR-640 and circ_0097271 or MCAM was verified by dual-luciferase reporter or RIP assay. Results. Circ_0097271’s expression was enhanced in OS samples and cells. The knockdown of circ_0097271 restrained OS cell growth and migration, and its downregulation also blocked solid tumor growth in vivo. Circ_0097271 targeted miR-640 and negatively modulated miR-640 expression. MiR-640 was poorly expressed in OS, and its depletion recovered OS cell growth and migration that were repressed by circ_0097271 knockdown. MiR-640 bound to MCAM 3’UTR and thus suppressed MCAM expression. MCAM knockdown repressed OS cell growth and migration, while additional miR-640 depletion partially abolished the anticancer effects of MCAM knockdown in OS cells. Conclusion. Circ_0097271 is an oncogenic driver and contributes to OS development via targeting the miR-640/MCAM pathway, which provides a potential opinion for OS treatment.

Hsp90: From Cellular to Organismal Proteostasis

Assuring a healthy proteome is indispensable for survival and organismal health. Proteome disbalance and the loss of the proteostasis buffer are hallmarks of various diseases. The essential molecular chaperone Hsp90 is a regulator of the heat shock response via HSF1 and a stabilizer of a plethora of signaling proteins. In this review, we summarize the role of Hsp90 in the cellular and organismal regulation of proteome maintenance.

Gossypin'in farklı kanser hücre dizilerinde HSP60 ve HSP70'in gen ekspresyonu üzerindeki etkisi

Amaç: Bu çalışmanın amacı, gossypin'in farklı kanser hücre hatlarında ısı şok proteinleri (HSP) genlerinin ekspresyon seviyesi üzerindeki etkisini incelemektir. Gereç ve Yöntem: Hücreler, standart kültür koşulları altında büyütüldü. Kanser hücreleri, farklı konsantrasyonlarda (5-100 µg/ml) gossypin ve pozitif kontrol olarak sisplatin (50 µM) ile muamele edildi. Gossypin'in hücre canlılığı ve etkili doz aralığı (5-100 µg/ml), 24, 48 ve 72. saatlerde MTT ile belirlendi. RNA izolasyonu ve cDNA sentezinden sonra, HSP60 ve HSP70 gen ekpresyon seviyesi RT-PCR ile analiz edildi. Gen ekspresyonu için 2-∆∆ct methodu kullanıldı. Bulgular: MTT sonuçlarına göre kanser hücre hatlarında 25-50-100 µg/ml gossipin dozlarının HSP60 ve HSP70 gen ekspresyon seviyeleri üzerinde etkili olduğu bulundu. Gossypin, üç hücre hattında HSP60 ve HSP70'in ekspresyonunu doza bağımlı olarak etkilemiştir. Üç hücre hattında, 50 µg/ml ve 100 µg/ml gossipin dozları, HSP60 ve HSP70'in ekspresyonunu kontrol grubuna kıyasla önemli ölçüde azalttı. Sonuç: Sonuçlarımız, farklı hücre dizilerinde çeşitli dozlarda gossypinin antikarsinojenik etkisini güçlü bir şekilde desteklemektedir. Fakat, daha fazla in vivo araştırma ve insan çalışmalarına ihtiyaç olduğuna inanıyoruz. Bulgularımız, gossypin'nin farklı kanser türlerinin önlenmesi ve/veya tedavisi için yeni stratejiler geliştirmek için daha ileri araştırmalar için uygun aday ajan olabileceğini düşündürmektedir.

Heat Shock Protein 90 (HSP90) Inhibitors as Anticancer Medicines: A Review on the Computer-Aided Drug Discovery Approaches over the Past Five Years

Cancer is a disease caused by the uncontrolled, abnormal growth of cells in different anatomic sites. In 2018, it was predicted that the worldwide cancer burden would rise to 18.1 million new cases and 9.6 million deaths. Anticancer compounds, often known as chemotherapeutic medicines, have gained much interest in recent cancer research. These medicines work through various biological processes in targeting cells at various stages of the cell's life cycle. One of the most significant roadblocks to developing anticancer drugs is that traditional chemotherapy affects normal cells and cancer cells, resulting in substantial side effects. Recently, advancements in new drug development methodologies and the prediction of the targeted interatomic and intermolecular ligand interaction sites have been beneficial. This has prompted further research into developing and discovering novel chemical species as preferred therapeutic compounds against specific cancer types. Identifying new drug molecules with high selectivity and specificity for cancer is a prerequisite in the treatment and management of the disease. The overexpression of HSP90 occurs in patients with cancer, and the HSP90 triggers unstable harmful kinase functions, which enhance carcinogenesis. Therefore, the development of potent HSP90 inhibitors with high selectivity and specificity becomes very imperative. The activities of HSP90 as chaperones and cochaperones are complex due to the conformational dynamism, and this could be one of the reasons why no HSP90 drugs have made it beyond the clinical trials. Nevertheless, HSP90 modulations appear to be preferred due to the competitive inhibition of the targeted N-terminal adenosine triphosphate pocket. This study, therefore, presents an overview of the various computational models implored in the development of HSP90 inhibitors as anticancer medicines. We hereby suggest an extensive investigation of advanced computational modelling of the three different domains of HSP90 for potent, effective inhibitor design with minimal off-target effects.

Liposomal Glucose Oxidase for Enhanced Photothermal Therapy and Photodynamic Therapy against Breast Tumors

Organic near-infrared fluorescent dye mediated photothermal therapy (PTT) and photodynamic therapy (PDT) suffer from heat shock response, since, heat shock proteins (HSPs) are overexpressed and can repair the proteins damaged by PTT and PDT. Starvation therapy by glucose oxide (GOx) can inhibit the heat shock response by limiting the energy supply. However, the delivery of sufficient and active GOx remains a challenge. To solve this problem, we utilize liposomes as drug carriers and prepare GOx loaded liposome (GOx@Lipo) with a high drug loading content (12.0%) and high enzymatic activity. The successful delivery of GOx shows excellent inhibition of HSPs and enhances PTT and PDT. Additionally, we apply the same liposome formulation to load near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo cyanine iodide (DiR) and prepare DiR contained liposomes (DiR@Lipo) for PTT and PDT. The liposomal formulation substantially enhances the PTT and PDT properties of DiR as well as the cellular uptake and tumor accumulation. Finally, the combination therapy shows excellent tumor inhibition on 4T1 tumor-bearing mice. Interestingly, we also find that the starvation therapy can efficiently inhibit tumor metastasis, which is probably due to the immunogenic effect. Our work presents a biocompatible and effective carrier for the combination of starvation therapy and phototherapy, emphasizing the importance of auxiliary starvation therapy against tumor metastasis and offering important guidance for clinical PTT and PDT.

The functional roles of the circRNA/Wnt axis in cancer

CircRNAs, covalently closed noncoding RNAs, are widely expressed in a wide range of species ranging from viruses to plants to mammals. CircRNAs were enriched in the Wnt pathway. Aberrant Wnt pathway activation is involved in the development of various types of cancers. Accumulating evidence indicates that the circRNA/Wnt axis modulates the expression of cancer-associated genes and then regulates cancer progression. Wnt pathway-related circRNA expression is obviously associated with many clinical characteristics. CircRNAs could regulate cell biological functions by interacting with the Wnt pathway. Moreover, Wnt pathway-related circRNAs are promising potential biomarkers for cancer diagnosis, prognosis evaluation, and treatment. In our review, we summarized the recent research progress on the role and clinical application of Wnt pathway-related circRNAs in tumorigenesis and progression.

The Incredible Potential of Exosomes as Biomarkers in the Diagnosis of Colorectal Cancer

Colorectal cancer (CRC) is common cancer that is one of the leading causes of cancerrelated deaths around the world. The creation of new biomarkers for this disease is an important public health strategy for lowering the disease's mortality rate. According to new research, exosomes may be important sources of biomarkers in CRC. Exosomes are nanometer-sized membrane vesicles (30-200 nm) secreted by normal and cancer cells that transport RNA and proteins between cells and are thought to help with intercellular communication. Exosomes have been linked to CRC initiation and progression, and some differentially expressed RNAs and proteins in exosomes have been identified as potential cancer detection candidates. As a result, studying the relationship between exosomes and CRC may aid in the development of new biomarkers for the disease. This article discusses the importance of exosomes as biomarkers in the diagnosis of CRC, as well as their use in the treatment of CRC metastasis, chemoresistance, and recrudescence. The benefits and drawbacks of using exosomes as tumour markers are also discussed.