Cell cycle-related and expression-elevated protein in tumor overexpression is associated with proliferation behaviors and poor prognosis in non-small-cell lung cancer

The emerging role of PPAR-alpha in breast cancer

Breast cancer has been confirmed to have lipid disorders in the tumour microenvironment. Peroxisome proliferator-activated receptor alpha (PPARα) is a ligand-activated transcriptional factor that belongs to the family of nuclear receptors. PPARα regulates the expression of genes involved in fatty acid homeostasis and is a major regulator of lipid metabolism. Because of its effects on lipid metabolism, an increasing number of studies have investigated the relationship of PPARα with breast cancer. PPARα has been shown to impact the cell cycle and apoptosis in normal cells and tumoral cells through regulating genes of the lipogenic pathway, fatty acid oxidation, fatty acid activation, and uptake of exogenous fatty acids. Besides, PPARα is involved in the regulation of the tumour microenvironment (anti-inflammation and inhibition of angiogenesis) by modulating different signal pathways such as NF-κB and PI3K/AKT/mTOR. Some synthetic PPARα ligands are used in adjuvant therapy for breast cancer. PPARα agonists are reported to reduce the side effects of chemotherapy and endocrine therapy. In addition, PPARα agonists enhance the curative effects of targeted therapy and radiation therapy. Interestingly, with the emerging role of immunotherapy, attention has been focused on the tumour microenvironment. The dual functions of PPARα agonists in immunotherapy need further research. This review aims to consolidate the operations of PPARα in lipid-related and other ways, as well as discuss the current and potential applications of PPARα agonists in tackling breast cancer.

Identification of prognostic values of the transcription factor-CpG-gene triplets in lung adenocarcinoma: A narrative review

OBJECTIVE

Abnormal DNA methylation can regulate carcinogenesis in lung adenocarcinoma (LUAD), while transcription factors (TFs) mediate methylation in a site-specific manner to affect downstream transcriptional regulation and tumor progression. Therefore, this study aimed to explore the TF-methylation-gene regulatory relationships that influence LUAD prognosis.

METHODS

Differential analyses of methylation sites and genes were generated by integrating transcriptome and methylome profiles from public databases. Through target gene identification, motif enrichment in the promoter region, and TF prediction, TF-methylation and methylation-gene relation pairs were obtained. Then, the prognostic TF-methylation-gene network was constructed using univariate Cox regression analysis. Prognostic models were constructed based on the key regulatory axes. Finally, Kaplan-Meier curves were created to evaluate the model efficacy and the relationship between candidate genes and prognosis.

RESULTS

A total of 1878 differential expressed genes and 1233 differential methylation sites were screened between LUAD and normal samples. Then 10 TFs were predicted to bind 144 enriched motifs. After integrating TF-methylation and methylation-gene relations, a prognostic TF-methylation-gene network containing 4 TFs, 111 methylation sites, and 177 genes was constructed. In this network, ERG-cg27071152-MTURN and FOXM1-cg19212949-PTPR regulatory axes were selected to construct the prognostic models, which showed robust abilities in predicting 1-, 3-, and 5-year survival probabilities. Finally, ERG and MTURN were downregulated in LUAD samples, whereas FOXM1 and PTPR were upregulated. Their expression levels were related to LUAD prognosis.

CONCLUSION

ERG-cg27071152-MTURN and FOXM1-cg19212949-PTPR regulatory axes were proposed as potential biomarkers for predicting the prognosis of LUAD.

An Important Role for RPRD1B in the Heat Shock Response

During the heat shock response (HSR), heat shock factor (HSF1 in mammals) binds to target gene promoters, resulting in increased expression of heat shock proteins that help maintain protein homeostasis and ensure cell survival. Besides HSF1, only a relatively few transcription factors with a specific role in ensuring correctly regulated gene expression during the HSR have been described. Here, we use proteomic and genomic (CRISPR) screening to identify a role for RPRD1B in the response to heat shock. Indeed, cells depleted for RPRD1B are heat shock sensitive and show decreased expression of key heat shock proteins (HSPs). These results add to our understanding of the connection between basic gene expression mechanisms and the HSR.

Eupalinolide B inhibits hepatic carcinoma by inducing ferroptosis and ROS-ER-JNK pathway

Primary hepatic carcinoma is a common malignant tumor. The classic molecular targeted drug sorafenib is costly and is only effective for some patients. Therefore, it is of great clinical significance to search for new molecular targeted drugs. Eupalinolide B (EB) from Eupatorium lindleyanum DC. is used to treat chronic tracheitis in clinical practice. However, the role of EB in hepatic carcinoma is unknown. In this study, we first measure the effect of EB on tumor growth in a xenograft model and PDX model. The cell proliferation and migration are also detected in human hepatocarcinoma cell lines (SMMC-7721 and HCCLM3). Then, we investigate cell cycle, cell apoptosis, cell necrosis, cell autophagy, and ferroptosis by flow cytometry, western blot analysis and electron microscopy. The results demonstrate that EB exerts anti-proliferative activity in hepatic carcinoma by blocking cell cycle arrest at S phase and inducing ferroptosis mediated by endoplasmic reticulum (ER) stress, as well as HO-1 activation. When HO-1 is inhibited, EB-induced cell death and ER protein expression are rescued. The migration-related mechanism consists of activation of the ROS-ER-JNK signaling pathway and is not connected to ferroptosis. In summary, we first discover that EB inhibits cell proliferation and migration in hepatic carcinoma, and thus EB is a promising anti-tumor compound that can be used for hepatic carcinoma.

Fuzheng Kang' ai decoction inhibits cell proliferation, migration and invasion by modulating mir-21-5p/human phosphatase and tensin homology deleted on chromosome ten in lung cancer cells

OBJECTIVE

To elucidate the potential molecular mechanism by which Fuzheng Kang'ai decoction (, FZKA) inhibits proliferation, migration, and invasion of lung cancer cells.

METHODS

Varying FZKA concentrations were used to manage lung cancer cells (A549 and PC9). We employed: cell counting kit-8 (CCK-8) and plate clone for-mation assays to examine the cell viability; flow cytometry (FCM) to analyze the cycle arrest; transwell and wound-healing assays to assess the cell invasion and migration, respectively. Further, a quantitative real-time polymerase chain reaction (qRT-PCR) assay was adopted to evaluate the miR-21-5p expression. For protein expression analysis, we employed the Western blot technique. Recombinant miR-21-5p overexpression adenovirus vector harboring GFP was constructed and transfected into A549 and PC9, after which we explored the effect of FZKA on miR-21-5p overexpression.

RESULTS

Notably, treatment with FZKA inhibited viability, clone-formation ability, invasion, and migration of lung cancer cells. Mechanistically, FZKA markedly suppressed miR-21-5p expression but elevated the human phosphatase and tensin homology deleted on chromosome ten (PTEN) protein level in both A549 and PC9 cells. Over-expression of miR-21-5p lowered PTEN protein expression. Besides, overexpressed miR-21-5p levels with adenovirus antagonized FZKA-upregulated PTEN protein expression.

CONCLUSION

The present study demonstrates how FZKA modulates cell biological behaviors, for instance, it impedes the proliferation by upregulating PTEN expression with miR-21-5p as the target. These findings unveil the potential novel molecular mechanisms from the microRNA aspect by which FZKA suppresses the growth of human lung cancer cells.

Circular RNA_ANKIB1 accelerates chemo-resistance of osteosarcoma via binding microRNA-26b-5p and modulating enhancer of zeste homolog 2

Osteosarcoma is a common bone malignancy in children and adolescents. Chemotherapeutic drug resistance is the major factor impacting the surgical outcome and prognosis of patients with osteosarcoma. This investigation assessed the role and mechanism of circular RNA_ANKIB1 in the development of osteosarcoma. The circular RNA (circ) _ANKIB1, microRNA (miR)-26b-5p, enhancer of zeste homolog 2 (EZH2) expression in OS samples was investigated through RT-qPCR. The EZH2, multidrug resistance protein 1 (MRP1), P-gp, and lipoprotein receptor-related protein (LRP) protein expressions were analyzed through western blot. The association between circ_ANKIB1 and the occurrence of clinic-pathological features in OS patients was assessed; the circular features of circ_ANKIB1 were analyzed. The hFOB1.19, KHOS, U2-OS OS cells were used to study the semi-inhibitory concentration IC50 of Doxorubicin (DXR)-resistant cells, clone formation, invasion, and apoptosis. The luciferase assay was used to study the binding of circ-ANKIB1 with miR-26b-5p and the targeting of miR-26b-5p with EZH2. In vivo experiments were performed via subcutaneous tumorigenic experiments. MiR-26b-5p in OS tissues and cells and DXR-resistant OS tissues and cells was silenced while circ_ANKIB1 and EZH2 were elevated. Circ_ANKIB1 silencing elevated miR-26b-5p, repressed EZH2, MRP1, P-gp, LRP, IC50, and elevated OS advancement. Circ_ANKIB1 bind miR-26b-5p. Reduced miR-26b-5p revered the influence of silencing circ_ANKIB1 on DXR resistant OS cells. MiR-26b-5p targeted EZH2, and EZH2 elevation reversed the impact of increasing miR-26b-5p on DXR resistant cells. Circ_ANKIB1 silencing suppressed DXR-resistant OS cells in vivo. In conclusion, Circ_ANKIB1 binds miR-26b-5p and modulates EZH2 to accelerate the chemo-resistance of osteosarcoma.

Predictions of the dysregulated competing endogenous RNA signature involved in the progression of human lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer worldwide. Until now, the molecular mechanisms underlying LUAD progression have not been fully explained. This study aimed to construct a competing endogenous RNA (ceRNA) network to predict the progression in LUAD.

METHODS

Differentially expressed lncRNAs (DELs), miRNAs (DEMs), and mRNAs (DEGs) were identified from The Cancer Genome Atlas (TCGA) database with a |log2FC|> 1.0 and a false discovery rate (FDR) < 0.05. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI) network, and survival analyses were performed to analyse these DEGs involved in the ceRNA network. Subsequently, the drug-gene interaction database (DGIdb) was utilized to select candidate LUAD drugs interacting with significant DEGs. Then, lasso-penalized Cox regression and multivariate Cox regression models were used to construct the risk score system. Finally, based on the correlations between DELs and DEGs involved in the risk score system, the final ceRNA network was identified. Meanwhile, the GEPIA2 database and immunohistochemical (IHC) results were utilized to validate the expression levels of selected DEGs.

RESULTS

A total of 340 DELs, 29 DEMs, and 218 DEGs were selected to construct the initial ceRNA network. Functional enrichment analyses indicated that 218 DEGs were associated with the KEGG pathway terms "microRNAs in cancer", "pathways in cancer", "cell cycle", "HTLV-1 infection", and the "PI3K-Akt signalling pathway". K-M survival analysis of all differentially expressed genes involved in the ceRNA network identified 24 DELs, 4 DEMs, and 29 DEGs, all of which were significantly correlated with LUAD progression (P< 0.05). Furthermore, 15 LUAD drugs interacting with 29 significant DEGs were selected. After lasso-penalized Cox regression and multivariate Cox regression modelling, PRKCE, DLC1, LATS2, and DPY19L1 were incorporated into the risk score system, and the results suggested that LUAD patients who had the high-risk score always suffered from a poorer overall survival. Additionally, the correlation coefficients between these 4 DEGs and their corresponding DELs involved in the ceRNA network suggested that there were 2 significant DEL-DEG pairs, NAV2-AS2 - PRKCE (r= 0.430, P< 0.001) and NAV2-AS2 - LATS2 (r= 0.338, P< 0.001). And NAV2-AS2 - mir-31 - PRKCE and NAV2-SA2 - mir-31 - LATS2 were finally identified as ceRNA network involved in the progression of LUAD.

CONCLUSIONS

The lncRNA-miRNA-mRNA ceRNA network plays an essential role in predicting the progression of LUAD. These results may improve our understanding and provide novel mechanistic insights to explore prognosis and therapeutic drugs for LUAD patients.

Evaluation of clinical value and potential mechanism of MTFR2 in lung adenocarcinoma via bioinformatics

Background

Mitochondrial fission regulator 2 (MTFR2) was involved in the progression and development of various cancers. However, the relationship between MTFR2 with lung adenocarcinoma (LUAD) had not been reported. Herein, this study analyzed the clinical significance and potential mechanisms of MTFR2 in LUAD via bioinformatics tools.

Results

We found that the level of MTFR2 was increased, and correlated with sex, age, smoking history, neoplasm staging, histological subtype and TP53 mutation status in LUAD patients. Kaplan-Meier survival analysis showed LUAD patients with increased MTFR2 had a poor prognosis. In addition, univariate COX regression analysis showed neoplasm staging, T stage, distant metastasis and MTFR2 level were risk factors for the prognosis of LUAD. A total of 1127 genes were coexpressed with MTFR2, including 840 positive and 208 negative related genes. KEGG and GSEA found that MTFR2 participated in the progression of LUAD by affecting cell cycle, DNA replication, homologous recombination, p53 signaling pathway and other mechanisms. The top 10 coexpressed genes, namely CDK1, CDC20, CCNB1, PLK1, CCNA2, AURKB, CCNB2, BUB1B, MAD2L1 and BUB1 were highly expressed, and were associated with poor prognosis in LUAD.

Conclusions

Consequently, we elucidated MTFR2 was a biomarker for diagnosis and poor prognosis in LUAD, and might participate in the progression of LUAD via affecting cell cycle, DNA replication, homologous recombination and p53 signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08378-3.

Immunohistochemical expression levels of cyclin D1 and CREPT reflect the course and prognosis in oral precancerous lesions and squamous cell carcinoma

Cyclin D1 is the most essential progressive regulator of the cell cycle, and its transcription is enhanced by CREPT (cell cycle-related and expression-elevated protein in tumour). These molecules regulate cell growth, and their aberrant expression can cause malignant transformation. In this study, the expression of these molecules was explored to investigate the molecular alterations in oral precancerous lesions and squamous cell carcinoma. Cyclin D1 and CREPT expression was examined immunohistochemically in tissue specimens from 55 patients with oral epithelial precursor lesions (OEPLs) and 84 patients with oral squamous cell carcinoma (OSCC). Associations between the results and clinicopathological variables were examined. Cyclin D1 and CREPT expression levels were higher in OSCC than in OEPLs. Furthermore, there were statistically significant differences in cyclin D1 expression among the different grades of OEPLs and OSCC lesions. In OSCC, there were statistically significant differences in CREPT expression according to sex, T stage, and degree of differentiation. In addition, the expression of both molecules was significantly correlated with postoperative metastasis and modes of invasion. The expression of cyclin D1 and CREPT was found to depend upon the state of development and progression of the oral epithelial lesions, and clinicopathological behaviours might be affected by these molecules in OSCC.

High expression of SPP1 in patients with chronic obstructive pulmonary disease (COPD) is correlated with increased risk of lung cancer

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airway inflammation and fixed airflow obstruction. Patients with COPD have increased risk of lung cancer (LC), and the coexistence of both diseases is associated with poorer survival. However, the mechanisms predisposing patients with COPD to LC development and poor prognosis remain unclear. Gene expression profiles were downloaded from the Gene Expression Omnibus. Twenty‐two data sets were included (n = 876). We identified 133 DEGs and 145 DEGs in patients with COPD and LC compared with healthy controls, respectively. There were 1544 DEGs in patients with LC and coexisting COPD compared with COPD, and these DEGs are mainly involved in the cell cycle, DNA replication, p53 signalling and insulin signalling. The biological processes primarily associated with these DEGs are oxidation reduction and apoptosis. SPP1 was the only overlapping DEG that was up‐regulated in patients with COPD and/or LC, and this was validated by qPCR in an independent cohort. The area under the curve value for SPP1 was 0.893 (0.822–0.963) for the prediction of LC in patients with COPD. High expression of SPP1 in patients with LC was associated with shorter survival time. Up‐regulation of SPP1 may be associated with increased risk of LC in patients with COPD and therefore may have potential as a therapeutic target for LC in patients with COPD.

Overexpression of cell-cycle related and expression-elevated protein in tumor (CREPT) in malignant cervical cancer

Objective

To explore the expression of cell-cycle related and expression-elevated protein in tumor (CREPT), cyclin D1, and transcription factor 4 (TCF4) in patients with cervical carcinoma.

Methods

This study enrolled 20 patients with cervical cancer and 10 control patients diagnosed with benign cervical lesions undergoing resection at the People’s Liberation Army General Hospital from January 2016 to December 2017. Cervical tissues were collected from all patients and their clinical characteristics were recorded. Protein and mRNA levels of CREPT, cyclin D1, and TCF4 were measured in tissue samples by immunohistochemistry, western blotting, and real-time polymerase chain reaction (PCR) and compared between the two groups.

Result

Protein and mRNA expression levels of CREPT, cyclin D1, and TCF4 were all significantly higher in the cervical cancer compared with the control group, according to western blot and PCR, respectively. CREPT expression was also significantly higher in the cervical cancer group according to immunohistochemistry.

Conclusion

Levels of CREPT, cyclin D1, and TCF4 were significantly elevated in cervical carcinoma tissues, and their expression levels were positively correlated, suggesting that these factors might play important roles during the development of cervical carcinoma.

Current understanding of CREPT and p15RS, carboxy-terminal domain (CTD)-interacting proteins, in human cancers

CREPT and p15RS, also named RPRD1B and RPRD1A, are RPRD (regulation of nuclear pre-mRNA-domain-containing) proteins containing C-terminal domain (CTD)-interacting domain (CID), which mediates the binding to the CTD of Rpb1, the largest subunit of RNA polymerase II (RNAPII). CREPT and p15RS are highly conserved, with a common yeast orthologue Rtt103. Intriguingly, human CREPT and p15RS possess opposite functions in the regulation of cell proliferation and tumorigenesis. While p15RS inhibits cell proliferation, CREPT promotes cell cycle and tumor growth. Aberrant expression of both CREPT and p15RS was found in numerous types of cancers. At the molecular level, both CREPT and p15RS were reported to regulate gene transcription by interacting with RNAPII. However, CREPT also exerts a key function in the processes linked to DNA damage repairs. In this review, we summarized the recent studies regarding the biological roles of CREPT and p15RS, as well as the molecular mechanisms underlying their activities. Fully revealing the mechanisms of CREPT and p15RS functions will not only provide new insights into understanding gene transcription and maintenance of DNA stability in tumors, but also promote new approach development for tumor diagnosis and therapy.

MiR-139-5p inhibits the proliferation of gastric cancer cells by targeting Regulation of Nuclear Pre-mRNA Domain Containing 1B

Regulation of Nuclear Pre-mRNA Domain Containing 1B (RPRD1B) has been of great interest in the field of oncology in recent years. The relationship between miRNAs and RPRD1B in gastric cancer (GC) has not been adequately reported. This study was designed to screen RPRD1B-targeted miRNAs and investigate its regulatory mechanism in GC cells. Quantitative RT-PCR and in situ hybridization were used to detect miRNA expression in GC tissues. Colony formation, EdU cell proliferation assay, and flow cytometry were used to analyze the cell cycle. Database-assisted gene expression analysis revealed that RPRD1B was targeted and regulated by miRNA-139-5p in GC. miRNA-139-5p expression was higher in GC tissue than in normal tissues and significantly correlated with tumor size, pathological stage, and disease-free survival of GC (p < 0.05). MiRNA-139-5p regulates GC cell proliferation and affects the transition from G1 to S phase. It binds explicitly to the 2013-2019 sites of the 3'UTR of RPRD1B and negatively regulates RPRD1B expression. We demonstrated that the ability of miR-139-5p to regulate GC cell proliferation depends on RPRD1B. This process is accompanied by changes in Cyclin D1 protein expression. We established a miR-139-5p/RPRD1B/tumor proliferation axis in GC, which may serve as novel biomarkers and drug targets for GC.

CHCHD2 is a potential prognostic factor for NSCLC and is associated with HIF-1a expression

Background

CHCHD2 was identified a novel cell migration-promoting gene, which could promote cell migration and altered cell adhesion when ectopically overexpressed in NIH3T3 fibroblasts, and it was identified as a protein necessary for OxPhos function as well. However, the clinic relevance of CHCHD2 expression in NSCLC remains unclear. Here we assumed that CHCHD2 expression would accompanies the expression of HIF-1α to response hypoxia in the occurrence of NSCLC.

Methods

In order to verify this hypothesis, correlations among the expression levels of CHCHD2 and HIF-1α were detected and analyzed in 209 pair cases of NSCLC. The expression and location of these molecules were assessed using Immunohistochemistry, immunohistofluorescence, qRT-PCR and western blotting. The differences and correlations of the expression of these two molecules with clinical pathological characteristics in NSCLC were statistically analyzed using Wilcoxon (W) text, Mann-Whitney U, Kruskal-Wallis H and cross-table tests. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of the expression of CHCHD2 and HIF-1α on the patients’ survival.

Results

Data showed that CHCHD2 and HIF-1α expression were higher in NSCLC than in normal tissues (all P = 0.000). CHCHD2 expression was significantly related with smoking, tumor size, differentiation degree, TNM Stage, lymph metastasis (all P<0.05). The HIF-1α expression was significantly associated with smoking, tumor category, differentiation degree, TNM Stage, Lymph metastasis (all P<0.05). There was a marked correlation of CHCHD2 and HIF-1α expression with histological type, differentiation and lymph metastasis of NSCLC (all P<0.05, r_s>0.3). Immunohistofluorescence showed that there were co-localization phenomenon in cytoplasm and nucleus between CHCHD2 and HIF-1α expression. NSCLC patients with higher CHCHD2 and HIF-1α expression had a significantly worse prognosis than those with lower CHCHD2 and HIF-1α expression (all P = 0.0001; log-rank test). The multivariate analysis indicated that CHCHD2 expression was an independent prognostic factor in NSCLC (hazard ratio [HR], 0.492, P = 0.001).

Conclusion

Our results indicate that over-expression of CHCHD2 would promote the expression of HIF-1α to adapt the hypoxia microenviroment in NSCLC and CHCHD2 could serves as a prognostic biomarker in NSCLC.

CREPT Promotes Melanoma Progression Through Accelerated Proliferation and Enhanced Migration by RhoA-Mediated Actin Filaments and Focal Adhesion Formation

Melanoma is one of the most aggressive cancers, and patients with distant metastases have dire outcomes. We observed previously that melanoma progression is driven by a high migratory potential of melanoma cells, which survive and proliferate under harsh environmental conditions. In this study, we report that CREPT (cell-cycle related and expression-elevated protein in tumor), an oncoprotein highly expressed in other cancers, is overexpressed in melanoma cells but not melanocytes. Overexpression of CREPT stimulates cell proliferation, migration, and invasion in several melanoma cell lines. Further, we show that CREPT enhances melanoma progression through upregulating and activating Ras homolog family member A (RhoA)-induced actin organization and focal adhesion assembly. Our study reveals a novel role of CREPT in promoting melanoma progression. Targeting CREPT may be a promising strategy for melanoma treatment.

Histone deacetylase 9 downregulation decreases tumor growth and promotes apoptosis in non-small cell lung cancer after melatonin treatment

Histone deacetylase 9 functions as an oncogene in a variety of cancers, but its role on non-small cell lung cancer (NSCLC) has not been reported. Melatonin was proven to possess anticancer actions, whereas its effect on NSCLC and underlying mechanisms remains poorly understood. In this study, 337 patients with complete clinicopathologic characteristics who underwent NSCLC surgery were recruited for the study. We found that NSCLC patients with high HDAC9 expression were correlated with worse overall survival and poor prognosis. HDAC9 knockdown significantly reduced NSCLC cell growth and induced apoptosis both in vivo and in vitro. Melatonin application also markedly inhibited cell proliferation, metastasis, and invasion and promoted apoptosis in NSCLC cells. Moreover, RNA-seq, real-time quantitative polymerase chain reaction, and western blot analyses showed that melatonin treatment decreased the HDAC9 level in NSCLC cells. A mechanistic study revealed that HDAC9 knockdown further enhanced the anticancer activities of melatonin treatment, whereas HDAC9 overexpression partially reversed the melatonin's anticancer effects. Additionally, the in vivo study found melatonin exerted anti-proliferative and pro-apoptotic effects on xenograft tumors which were also strengthened by HDAC9 knockdown. These results indicated that HDAC9 downregulation mediated the anti-NSCLC actions of melatonin, and targeting HDAC9 may be the novel therapeutic strategy for NSCLC.

MicroRNA-300 inhibits the growth of hepatocellular carcinoma cells by downregulating CREPT/Wnt/β-catenin signaling

A number of studies have demonstrated that altered expression levels of microRNA-300 (miR-300) are associated with tumor progression; however, little is understood regarding the role of miR-300 in hepatocellular carcinoma (HCC). The present study aimed to investigate the expression, biological function and potential regulatory mechanism of miR-300 in HCC. A miR-300 mimic and miR-300 inhibitor were transfected into liver cancer cells using RNAiMAX reagent. The expression levels of miR and mRNA were detected by reverse transcription-quantitative polymerase chain reaction. Protein expression levels were detected by western blot analysis. Cell growth was determined using Cell Counting Kit-8, a colony formation assay and cell cycle assay. miRNA targeting sites were analyzed using bioinformatics analysis and dual-luciferase reporter assay. The results revealed that miR-300 expression was significantly decreased in HCC tissues and cell lines. In vitro experiments demonstrated that overexpression of miR-300 could inhibit cell proliferation, colony formation and cell cycle progression of liver cancer cells. By contrast, inhibition of miR-300 was associated with increased rates of cell proliferation, colony formation and cell cycle progression. Notably, regulation of nuclear pre-mRNA domain-containing protein 1B (CREPT) was identified as a putative target gene of miR-300 by bioinformatics analysis. A luciferase reporter assay revealed that miR-300 directly targets the 3′-untranslated region of CREPT. Further data demonstrated that miR-300 can regulate CREPT expression levels in liver cancer cells. Notably, miR-300 was identified to regulate the Wnt/β-catenin signaling pathway in liver cancer cells. The restoration of CREPT expression partially reversed the antitumor effect of miR-300. In conclusion, the current results revealed a tumor suppressive role of miR-300 in HCC and indicated that the underlying mechanism was associated with a regulation of CREPT. The present study suggests that miR-300 and CREPT may serve as potential therapeutic targets for liver cancer.

CREPT promotes glioma cell proliferation and invasion by activating Wnt/β-catenin pathway and is a novel target of microRNA-596

Cell cycle-related and expression elevated protein in tumor (CREPT) is emerging as a novel cancer-related gene that is dysregulated in many kinds of malignancies. However, the expression and biological role of CREPT in glioma remains unclear. In the present study, we aimed to explore the potential function and regulation mechanism of CREPT in glioma. Results showed that CRETP expression was significantly upregulated in glioma cell lines. Depletion of CREPT by siRNA-mediated gene silencing markedly decreased the proliferative and invasive capabilities of glioma cells. Bioinformatics analysis predicted CREPT as a target gene of microRNA-596 (miR-596), which was further verified by real-time quantitative polymerase chain reaction and Western blot analysis. miR-596 was significantly decreased in glioma tissues and cell lines, and inversely correlated with CREPT expression in clinical specimens. Knockdown of CREPT or overexpression of miR-596 significantly restricted the activation of Wnt/β-catenin signaling in glioma cells. Moreover, overexpression of CREPT partially reversed the miR-596-mediated inhibitory effect on proliferation, invasion and Wnt/β-catenin signaling in glioma cells. Overall, these results demonstrate that CREPT exerts an oncogenic role in glioma and its expression is regulated by miR-596. Our study highlights the important role miR-596/CREPT/Wnt/β-catenin signaling axis may play in glioma.

MicroRNA-449b-5p suppresses the growth and invasion of breast cancer cells via inhibiting CREPT-mediated Wnt/β-catenin signaling

Accumulating evidence has suggested that microRNA-449b-5p (miR-449b-5p) plays an important role in the development and progression of multiple cancers. However, little is known about the role of miR-449b-5p in breast cancer. In this study, we aimed to investigate the expression level, biological function and underlying mechanism of miR-449b-5p in breast cancer. Our results showed that miR-449b-5p expression was frequently down-regulated in breast cancer cell lines and tissues. The overexpression of miR-449b-5p significantly inhibited growth and invasion, and induced the cell cycle arrest of breast cancer cells. In contrast, the inhibition of miR-449b-5p showed the opposite effect. Interestingly, bioinformatic analysis predicted that cell cycle-related and expression-elevated protein in tumor (CREPT), an important oncogene in breast cancer, was a potential target gene of miR-449b-5p. The overexpression of miR-449b-5p decreased CREPT expression while miR-449b-5p inhibition promoted CREPT expression in breast cancer cells. Restoration of CREPT expression in miR-449b-5p mimics transfected cells partially reversed the suppressive effect of miR-449b-5p on breast cancer cell growth and invasion. Notably, our results showed that miR-449b-5p overexpression decreased the expression of β-catenin and suppressed the activation of Wnt/β-catenin/TCF-4 signaling via targeting CREPT. In addition, blocking Wnt/β-catenin partially reversed the promotion effect of miR-449b-5p inhibition on breast cancer cell growth and invasion. Overall, these results reveal a tumor suppressive role of miR-449b-5p that restricts the growth and invasion of breast cancer cells through targeting CREPT and inhibiting CREPT-mediated activation of Wnt/β-catenin signaling. Our study suggests that the miR-449b-5p/CREPT/Wnt/β-catenin axis may play an important role in the pathogenesis of breast cancer and miR-449-5p may serve as a potential therapeutic target for breast cancer.

MicroRNA-501-3p restricts prostate cancer growth through regulating cell cycle-related and expression-elevated protein in tumor/cyclin D1 signaling

MicroRNA-501-3p (miR-501-3p) has been reported as a novel cancer-related miRNA in many types of cancer. However, the precise biological function of miR-501-3p in prostate cancer remains unknown. In this study, we aimed to investigate the regulatory effect and mechanism of miR-501-3p on cell growth of prostate cancer cells. We found that miR-501-3p expression was significantly downregulated in prostate cancer tissues and cell lines. Gain-of-function experiments showed that upregulation of miR-501-3p expression significantly decreased cell proliferation and colony formation, and induced cell cycle arrest in the G0/G1 phase. Bioinformatics analysis predicted that cell cycle-related and expression-elevated protein in tumor (CREPT) was a potential target gene of miR-501-3p., and the results of our luciferase reporter assay confirmed that miR-501-3p bound to the 3'-untranslated region of CREPT at the predicted binding site. Moreover, miR-501-3p was shown to negatively regulate CREPT expression in prostate cancer cells. Correlation analysis showed that miR-501-3p was inversely correlated with CREPT expression in prostate cancer tissues. Knockdown studies revealed that miR-501-3p regulated the expression of cyclin D1 by targeting CREPT. Additionally, the inhibitory effect of miR-501-3p on prostate cancer cell growth was partially reversed by CREPT overexpression. Overall, these results suggest that miR-501-3p restricts prostate cancer cell growth by targeting CREPT to inhibit the expression of cyclin D1. These findings indicate that the miR-501-3p/CREPT/cyclin D1 axis plays a crucial role in the progression of prostate cancer and may serve as potential therapeutic target.

CREPT is a novel predictor of the response to adjuvant therapy or concurrent chemoradiotherapy in esophageal squamous cell carcinoma

CREPT has been shown to be highly expressed in most tumors and is associated with a poor prognosis, but the histologic characteristics of CREPT expression and its impact on clinical outcomes in esophageal squamous cell carcinoma (ESCC) are unclear. Therefore, we retroactively evaluated tissue microarrays (TMA) from 300 surgical cases, including 300 ESCC tissues and 161 adjacent non-tumor tissues, and pretreatment tumor biopsies from 113 concurrent chemoradiotherapy (CCRT) cases by immunohistochemistry (IHC). Notably, CREPT was increasingly expressed from non-cancerous tissues to atypical hyperplasia to tumor tissues (P < 0.01). Furthermore, patients were divided into low CREPT (≤ 8 scores) and high CREPT (> 8 scores) groups. Patients with high CREPT expressions had a worse overall survival (OS) (5-year OS: 40.9% vs. 50.1%, P=0.040) and disease-free survival (DFS) (5-year DFS: 29.5 vs. 43.0%; P=0.020) than those with low expressions. Nevertheless, only in the high CREPT subgroup did adjuvant therapy (AT) prolong the OS (5-year OS: 53.8 vs. 28.9%; P=0.020), especially for adjuvant radiotherapy (ART) (5-year OS: 85.7 vs. 28.9%; P=0.037; 5-year DFS: 85.7 vs. 22.3%; P=0.020). Surprisingly, high CREPT expressions endowed CCRT-treated patients with higher complete response rates (50% vs. 26%; P=0.018) and a favorable OS (3-year OS: 54.3 vs. 28.1%; P=0.046) compared to low expression. Overall, our findings indicate that CREPT is highly expressed in ESCC tissue compared with non-cancerous tissue and this feature is associated with a poor prognosis. Otherwise, patients with high CREPT expression were more sensitive to AT and CCRT. Moreover, CREPT could be a predictive immunohistochemical biomarker used to guide individualized clinical treatment.

Cell cycle-related and expression-elevated protein in tumor overexpression is associated with proliferation behaviors and poor prognosis in non-small-cell lung cancer

The cell cycle‐related and expression‐elevated protein in tumor (CREPT) is overexpressed in several human malignancies. However, the clinical relevance of CREPT expression and its biological role in non‐small‐cell lung cancer (NSCLC) remains unclear. In this study, we detected the expression of CREPT in both NSCLC tissues and cell lines by immunohistochemistry, Western blot analysis, and RT‐PCR. The correlation between CREPT expression and clinicopathologic features was analyzed in 271 NSCLC patients. The prognostic value of CREPT expression was evaluated by Kaplan–Meier analysis and Cox regression analysis. CREPT was overexpressed in Calu‐1 cell lines by using plasmid vector and its biological function was explored both in vitro and in vivo. We found that CREPT was significantly overexpressed in NSCLC compared with paired adjacent non‐tumor tissues, and the expression level of CREPT was correlated with tumor differentiation, lymph node metastasis, and clinical stage. Kaplan–Meier analysis showed that the recurrence‐free survival and overall survival of high CREPT expression groups were significantly shorter than those of the low CREPT expression group. Multivariate analysis identified that CREPT might be an independent biomarker for the prediction of NSCLC prognosis. Overexpression of CREPT increased cell proliferation and enhanced the migration and invasion ability of Calu‐1 cells (a human NSCLC cell line with relative low CRPET expression) in vitro. Moreover, CREPT overexpression promoted tumor growth in a nude mice model. These results suggest that CREPT is closely relevant to the proliferation of NSCLC cells and it might be a potential prognostic marker in NSCLC patients.