CacyBP/SIP promotes tumor progression by regulating apoptosis and arresting the cell cycle in osteosarcoma

Pan-analysis reveals CACYBP to be a novel prognostic and predictive marker for multiple cancers

OBJECTIVES

Cancer has emerged as a global issue in terms of public health care and treatment. The significance of calcyclin binding protein (CACYBP) in various neoplasms suggests that it may serve as a novel biomarker for numerous types of human tumors.

METHODS

Our research investigated the differences in CACYBP expression between cancer tissues and normal tissues using a total of 18,787 samples from multiple centers. To explore the prognostic factor of CACYBP in cancers, we utilized Cox regression analysis and Kaplan-Meier curves. We also conducted Spearman's rank correlation analyses to determine the associations of CACYBP expression with the immune microenvironment, etc. Additionally, we applied gene set enrichment analysis to explore the underlying mechanisms of CACYBP in cancers. A partial validation of CacyBP expression in cancer tissues was performed through lung adenocarcinoma samples using Western blotting and paired t-test.

RESULTS

Compared to normal tissues, CACYBP exhibited high expression levels in 14 cancer types, including breast invasive carcinoma, and low expression levels in six cancers, including glioblastoma multiforme (P < 0.05). CACYBP expression was found to be significantly associated with the prognosis of 13 cancers, including adrenocortical carcinoma (P < 0.05). CACYBP demonstrated a robust ability to distinguish 15 cancers, including cholangiocarcinoma, from their control samples (area under the curve > 0.8). Furthermore, CACYBP expression was correlated with tumor mutational burden, microsatellite instability, and immune infiltration levels, indicating its potential as an exciting target for cancer treatment. CACYBP may exert its effects on several signaling pathways, including cytokine-cytokine receptor interaction, in various cancers. Compared with paired adjacent specimens, the expression level of CacyBP protein was up-regulated in lung adenocarcinoma specimens (P < 0.05), partially validating the increased expression of CACYBP in cancers.

CONCLUSIONS

CACYBP has the potential to serve as a novel prognostic and predictive marker for multiple human cancers.

Human cells with osteogenic potential in bone tissue research

Bone regeneration after injury or after surgical bone removal due to disease is a serious medical challenge. A variety of materials are being tested to replace a missing bone or tooth. Regeneration requires cells capable of proliferation and differentiation in bone tissue. Although there are many possible human cell types available for use as a model for each phase of this process, no cell type is ideal for each phase. Osteosarcoma cells are preferred for initial adhesion assays due to their easy cultivation and fast proliferation, but they are not suitable for subsequent differentiation testing due to their cancer origin and genetic differences from normal bone tissue. Mesenchymal stem cells are more suitable for biocompatibility testing, because they mimic natural conditions in healthy bone, but they proliferate more slowly, soon undergo senescence, and some subpopulations may exhibit weak osteodifferentiation. Primary human osteoblasts provide relevant results in evaluating the effect of biomaterials on cellular activity; however, their resources are limited for the same reasons, like for mesenchymal stem cells. This review article provides an overview of cell models for biocompatibility testing of materials used in bone tissue research.

CACYBP knockdown inhibits progression of prostate cancer via p53

PURPOSE

Prostate cancer (PC) is one of the most common malignant tumors of genitourinary system in men. CACYCLIN binding protein (CACYBP) is involved in the progression of a variety of cancers. The aim of this study was to explore the expression and functional role of CACYBP in PC.

METHODS

The expression of CACYBP in PC was evaluated by immunohistochemical (IHC) staining and qRT-PCR. Subsequently, we established lentivirus-mediated CACYBP knockdown in PC cell lines. The biological roles of CACYBP on proliferation, apoptosis, cycle distribution, migration and tumor formation of PC were investigated by Celigo cell counting assay, flow cytometry, transwell assay, wound-healing assay and mice xenograft models, respectively.

RESULTS

CACYBP was highly expressed in PC and was positively correlated with the pathological grade of PC patients. Knockdown of CACYBP inhibited proliferation, enhanced apoptosis, arrested cell cycle in G2 and suppressed migration of PC cell lines in vitro. In addition, CACYBP knockdown weakened the tumor growth of PC in vivo. Moreover, addition of p53 inhibitor could effectively alleviate the inhibitory effect of CACYBP knockdown on cell activity.

CONCLUSION

This study revealed that knockdown of CACYBP inhibited the proliferation, migration and tumorigenicity of PC, which may serve as a potential therapeutic target for the treatment of PC.

A Risk Model Based on Immune-Related Genes Predicts Prognosis and Characterizes the Immune Landscape in Esophageal Cancer

Aberrant immune gene expression has been shown to have close correlations with the occurrence and progression of esophageal cancer (EC). We aimed to generate a prognostic signature based on immune-related genes (IRGs) capable of predicting prognosis, immune checkpoint gene (ICG) expressions, and half-inhibitory concentration (IC₅₀) for chemotherapy agents for EC patients. Transcriptome, clinical, and mutation data on tumorous and paratumorous tissues from EC patients were collected from The Cancer Genome Atlas (TCGA) database. Then, we performed differential analysis to identify IRGs differentially expressed in EC. Their biofunctions and related pathways were explored using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. These gene expression profiling data were merged with survival information and subjected to univariate Cox regression to select prognostic genes, which were then included in a Lasso-Cox model for signature generation (risk score calculation). Patients were divided into the high- and low-risk groups using the median risk score as a cutoff. The accuracy of the signature in overall survival prediction was assessed, so were its performances in predicting ICG expressions and IC₅₀ for chemotherapy and targeted therapy agents and immune cell landscape characterization. Fifteen prognostic IRGs were identified, seven of which were optimal for risk score calculation. As expected, high-risk patients had worse overall survival than low-risk individuals. Significant differences were found in tumor staging, immune cell infiltration degree, frequency of tumor mutations, tumor mutation burden (TMB), and immune checkpoint gene expressions between high- vs. low-risk patients. Further, high-risk patients exhibited high predicted IC₅₀ for paclitaxel, cisplatin, doxorubicin, and erlotinib compared to low-risk patients. The seven-IRG-based signature can independently and accurately predict overall survival and tumor progression, characterize the tumor immune microenvironment (TIME) and estimate ICG expressions and IC₅₀ for antitumor therapies. It shows the potential of guiding personalized treatment for EC patients.

Tumor suppressing role of serum-derived exosomal microRNA-15a in osteosarcoma cells through the GATA binding protein 2/murine double minute 2 axis and the p53 signaling pathway

Exosomes are emerging tools for transporting lipids, proteins, microRNAs (miRNAs), or other biomarkers for clinical purposes. They have produced widespread concern in managing human diseases, including osteosarcoma (OS). This study focuses on the function of serum-derived exosomal miR-15a in the growth of OS cells and the mechanism of action. Differentially expressed genes between OS and normal samples were screened using two datasets GSE70367 and GSE65071. miR-15a was poorly expressed, whereas GATA-binding protein 2 (GATA2) and murine double minute 2 (MDM2) were abundantly expressed in OS samples. miR-15a and its target mRNAs, including GATA2, were enriched in the p53 signaling pathway. miR-15a directly targets GATA2 mRNA to inhibit its expression, whereas GATA2 activates the transcription of MDM2, a negative regulator of p53. Overexpression of GATA2 and MDM2 promoted proliferation and cell cycle progression of MG-63 cells, whereas miR-15a blocked this axis and suppressed cell growth. miR-15a was identified as a major cargo of serum-derived exosomes, and exosomes conveying miR-15a were internalized by OS cells. This study demonstrated that miR-15a suppresses the GATA2/MDM2 axis to inhibit the proliferation and invasiveness of OS cells in vitro through the p53 signaling pathway.

Knockout of Calcyclin Binding Protein Impedes the Growth of Breast Cancer Cells by Regulating Cell Apoptosis and β-Catenin Signaling

Breast invasive carcinoma (BRCA) is becoming the most common malignant disease worldwide, and there is intense interest in identifying diagnostic biomarkers that can be targeted for treatment of BRCA. Recent evidence has shown that calcyclin binding protein (CacyBP) can function as either a tumor promoter or suppressor during carcinogenesis. Data in The Cancer Genome Atlas (TCGA) database show that CacyBP is overexpressed in human BRCA tissues, and high levels of CacyBP are associated with shorter overall survival. Immunohistochemical staining has shown that CacyBP levels are high in cancer tissue samples and associated with a higher likelihood of disease progression. We, therefore, conducted a knockout assay to determine the role of CacyBP in the development of BRCA. Knockout of CacyBP significantly inhibited MCF7 cell proliferation and colony formation. Apoptosis was higher in CacyBP knockout cells compared with control cells. Microarray analysis showed that the CacyBP knockout caused dysregulation of numerous genes closely related to β-catenin signaling, whereas quantitative reverse-transcription PCR and immunoblotting showed that it to be inactivated. In summary, we conclude that when overexpressed, CacyBP acts as a potential oncogene for BRCA by regulating β-catenin signaling.