TP53 Regulated Inhibitor of Apoptosis 1 (TRIAP1) stable silencing increases late apoptosis by upregulation of caspase 9 and APAF1 in RPMI8226 multiple myeloma cell line

In Silico and In Vitro Exploration of Poziotinib and Olmutinib Synergy in Lung Cancer: Role of hsa-miR-7-5p in Regulating Apoptotic Pathway Marker Genes

Background and objectives: Non-small cell lung cancer (NSCLC) is often caused by EGFR mutations, leading to overactive cell growth pathways. Drug resistance is a significant challenge in lung cancer treatment, affecting therapy effectiveness and patient survival. However, combining drugs in research shows promise in addressing or delaying resistance, offering a more effective approach to cancer treatment. In this study, we investigated the potential alterations in the apoptotic pathway in A549 cells induced by a combined targeted therapy using tyrosine kinase inhibitors (TKIs) olmutinib and poziotinib, focusing on cell proliferation, differential gene expression, and in silico analysis of apoptotic markers. Methods: A combined targeted therapy involving olmutinib and poziotinib was investigated for its impact on the apoptotic pathway in A549 cells. Cell proliferation, quantitative differential gene expression, and in silico analysis of apoptotic markers were examined. A549 cells were treated with varying concentrations (1, 2.5, and 5 μM) of poziotinib, olmutinib, and their combination. Results: Treatment with poziotinib, olmutinib, and their combination significantly reduced cell proliferation, with the most pronounced effect at 2.5 μM (p < 0.005). A synergistic antiproliferative effect was observed with the combination of poziotinib and olmutinib (p < 0.0005). Quantitative differential gene expression showed synergistic action of the drug combination, impacting key apoptotic genes including STK-11, Bcl-2, Bax, and the Bax/Bcl-2 ratio. In silico analysis revealed direct interactions between EGFR and ERBB2 genes, accounting for 77.64% of their interactions, and 8% co-expression with downstream apoptotic genes. Molecular docking indicated strong binding of poziotinib and olmutinib to extrinsic and intrinsic apoptotic pathway markers, with binding energies of -9.4 kcal/mol and -8.5 kcal/mol, respectively, on interacting with STK-11. Conclusions: Combining poziotinib and olmutinib therapies may significantly improve drug tolerance and conquer drug resistance more effectively than using them individually in lung cancer patients, as suggested by this study's mechanisms.

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.

Transcriptomic Analysis Reveals That Granulocyte Colony-Stimulating Factor Trigger a Novel Signaling Pathway (TAF9-P53-TRIAP1-CASP3) to Protect Retinal Ganglion Cells after Ischemic Optic Neuropathy

Optic nerve head (ONH) infarct can result in progressive retinal ganglion cell (RGC) death. The granulocyte colony-stimulating factor (GCSF) protects the RGC after ON infarct. However, protective mechanisms of the GCSF after ONH infarct are complex and remain unclear. To investigate the complex mechanisms involved, the transcriptome profiles of the GCSF-treated retinas were examined using microarray technology. The retinal mRNA samples on days 3 and 7 post rat anterior ischemic optic neuropathy (rAION) were analyzed by microarray and bioinformatics analyses. GCSF treatment influenced 3101 genes and 3332 genes on days 3 and 7 post rAION, respectively. ONH infarct led to changes in 702 and 179 genes on days 3 and 7 post rAION, respectively. After cluster analysis, the levels of TATA box-binding protein (TBP)-associated factor were significantly reduced after ONH infarct, but these significantly increased after GCSF treatment. The network analysis revealed that TBP associated factor 9 (TAF9) can bind to P53 to induce TP53-regulated inhibitor of apoptosis 1 (TRIAP1) expression. To evaluate the function of TAF9 in RGC apoptosis, GCSF plus TAF9 siRNA-treated rats were evaluated using retrograde labeling with FluoroGold assay, TUNEL assay, and Western blotting in an rAION model. The RGC densities in the GCSF plus TAF9 siRNA-treated rAION group were 1.95-fold (central retina) and 1.75-fold (midperipheral retina) lower than that in the GCSF-treated rAION group (p < 0.05). The number of apoptotic RGC in the GCSF plus TAF9 siRNA-treated group was threefold higher than that in the GCSF-treated group (p < 0.05). Treatment with TAF9 siRNA significantly reduced GCSF-induced TP53 and TRIAP1 expression by 2.4-fold and 4.7-fold, respectively, in the rAION model. Overexpression of TAF9 significantly reduced apoptotic RGC and CASP3 levels, and induced TP53 and TRIAP1 expression in the rAION model. Therefore, we have demonstrated that GCSF modulated a new pathway, TAF9-P53-TRIAP1-CASP3, to control RGC death and survival after ON infarct.

CIGB-300-Regulated Proteome Reveals Common and Tailored Response Patterns of AML Cells to CK2 Inhibition

Protein kinase CK2 is a highly pleiotropic and ubiquitously expressed Ser/Thr kinase with instrumental roles in normal and pathological states, including neoplastic phenotype in solid tumor and hematological malignancies. In line with previous reports, CK2 has been suggested as an attractive prognostic marker and molecular target in acute myeloid leukemia (AML), a blood malignant disorder that remains as an unmet medical need. Accordingly, this work investigates the complex landscape of molecular and cellular perturbations supporting the antileukemic effect exerted by CK2 inhibition in AML cells. To identify and functionally characterize the proteomic profile differentially modulated by the CK2 peptide-based inhibitor CIGB-300, we carried out LC-MS/MS and bioinformatic analysis in human cell lines representing two differentiation stages and major AML subtypes. Using this approach, 109 and 129 proteins were identified as significantly modulated in HL-60 and OCI-AML3 cells, respectively. In both proteomic profiles, proteins related to apoptotic cell death, cell cycle progression, and transcriptional/translational processes appeared represented, in agreement with previous results showing the impact of CIGB-300 in AML cell proliferation and viability. Of note, a group of proteins involved in intracellular redox homeostasis was specifically identified in HL-60 cell-regulated proteome, and flow cytometric analysis also confirmed a differential effect of CIGB-300 over reactive oxygen species (ROS) production in AML cells. Thus, oxidative stress might play a relevant role on CIGB-300-induced apoptosis in HL-60 but not in OCI-AML3 cells. Importantly, these findings provide first-hand insights concerning the CIGB-300 antileukemic effect and draw attention to the existence of both common and tailored response patterns triggered by CK2 inhibition in different AML backgrounds, a phenomenon of particular relevance with regard to the pharmacologic blockade of CK2 and personalized medicine.

Non-coding RNAs as biomarkers for hepatocellular carcinoma-A systematic review

Hepatocellular carcinoma (HCC) is the sixth most common malignancy in the world and the fourth leading cause of cancer-related death, and its incidence is increasing globally. Despite significant advances in treatment strategies for HCC, the prognosis is still poor due to its high recurrence rate. Therefore, there is an urgent need to understand the pathogenesis of HCC and further develop new therapies to improve the prognosis and quality of life of HCC patients. MicroRNAs (miRNAs, miRs) are small non-coding RNAs involved in post-transcriptional regulation of gene expression that is abnormally expressed in cancer-associated genomic regions or vulnerable sites. More and more findings have shown that miRNAs are important regulatory factors of mRNA expression in HCC, and they are receiving more and more attention as a possible key biomarker of HCC. This review mainly summarizes the potential applied value on miRNAs as diagnostic, drug resistant, prognostic, and therapeutic biomarkers in the diagnosis, therapy, and prognosis of HCC. Also, we summarize the research value of long non-coding RNA (lncRNAs), circular RNAs (circRNAs), and miRNAs network in HCC as novel biomarkers, aiming at providing some references for the therapy of HCC.

Transcriptome comparisons detect new genes associated with apoptosis of cattle and buffaloes preantral follicles

Background

To develop new breeding technology to improve the breeding ability of bovine, it is the development trend to find the main reason for the occurrence of atresia in these organisms. Transcriptomes of small (100–120 μm) and large (200–220 μm) preantral follicles from cattle and buffalo ovaries were evaluated in vivo and in vitro to understand the transcriptional modulation in preantral follicles that leads to the phenomenon of atresia.

Methods

The preantral follicles were checked as dead, damage, or live follicles in vivo and in vitro by using trypan blue then bisbenzimide and propidium iodine. Transcriptomes of small (100–120 μm) and large (200–220 μm) preantral follicles of cattle and buffalo were evaluated in vivo and in vitro by microarray and RT-PCR. Healthy preantral follicles were selected based on staining results, and then RNA was extracted from them.

Results

The viability percentage of preantral follicles in cattle was higher (26.7% and 20%) than buffalo (10%) in vivo and in vitro, respectively. According to the microarray data analysis for cattle preantral follicles, only eleven genes were detected corresponding to five upregulated and six downregulated in large size (200–220 μm) compared to small (100–120 μm) size preantral follicles, while in buffalo, 171 genes were detected (92 upregulated and 79 downregulated) in large size compared to small preantral follicle size. The results of RT-PCR of the selected genes (FASTKD1, BAG2, RHOB, AGTR2, MEF2C, BCL10, G2E3, TM2D1, IGF-I, IGFBP3, PRDX3, and TRIAP1) validated the microarray results. In conclusion, the data of gene expression showed significant differences between small and large sizes in both buffalo and cattle preantral follicles.

Conclusion

Apoptotic genes were upregulated in the large preantral follicle compared with the small preantral follicles. Moreover, the expression level of these apoptotic genes was significantly upregulated in buffalo than in the cattle. Most of these genes were significantly upregulated in the large buffalo preantral follicle compared with the small size. However, anti-apoptotic genes were upregulated in large cattle preantral follicle and downregulated in large buffalo preantral follicle.

Contribution of Apaf-1 to the pathogenesis of cancer and neurodegenerative diseases

Deregulation of apoptosis is associated with various pathologies, such as neurodegenerative disorders at one end of the spectrum and cancer at the other end. Generally speaking, differentiated cells like cardiomyocytes, skeletal myocytes and neurons exhibit low levels of Apaf-1 (Apoptotic protease activating factor 1) protein suggesting that down-regulation of Apaf-1 is an important event contributing to the resistance of these cells to apoptosis. Nonetheless, upregulation of Apaf-1 has not emerged as a common phenomenon in pathologies associated with enhanced neuronal cell death, i.e., neurodegenerative diseases. In cancer, on the other hand, Apaf-1 downregulation is a common phenomenon, which occurs through various mechanisms including mRNA hyper-methylation, gene methylation, Apaf-1 localization in lipid rafts, inhibition by microRNAs, phosphorylation, and interaction with specific inhibitors. Due to the diversity of these mechanisms and involvement of other factors, defining the exact contribution of Apaf-1 to the development of cancer in general and neurodegenerative disorders, in particular, is complicated. The current review is an attempt to provide a comprehensive image of Apaf-1's contribution to the pathologies observed in cancer and neurodegenerative diseases with the emphasis on the therapeutic aspects of Apaf-1 as an important target in these pathologies.

The effect of miR-539 regulating TRIAP1 on the apoptosis, proliferation, migration and invasion of osteosarcoma cells

Objective

The purpose of this study is to explore the effect of miRNA-539 on osteosarcoma (OS) and the underlying mechanism, so as to find a new method for early diagnosis and treatment of osteosarcoma.

Method

miRNA-539 mimics was transfected into osteosarcoma cells 143b and MG-63 and upregulated the expression of miR-539. QT-PCR was used to detect transfection efficacy. CCK-8 method was used to detect proliferation of 143b and MG-63 osteosarcoma cells and flow cytometry was used to detect the apoptosis of osteosarcoma cells 143b and MG-63. Wound-healing test and Transwell test were used to detect the migration and invasion ability of osteosarcoma cells. TRIAP1 was found to be the potential target gene of miRNA-539 by online bioinformatics software and the expression level of TRIAP1 in osteosarcoma cells overexpressing miRNA-539 was detected by qT-PCR. Western blot was used to detect the level of expression of TRIAP1 and its downstream genes (p53, p21, apaf1 and caspase9) in osteosarcoma cells 143b and MG63 transfected with miR-539 mimics or miR-539 mimics-NC. A model of osteosarcoma subcutaneously transplanted in nude mice was constructed to observe the effect of miRNA-539 on the growth rate of osteosarcoma in vivo.

Results

After transfection of miRNA-539 mimics in osteosarcoma cells 143b and MG63, the proliferation level, migration ability, and invasion ability of the osteosarcoma cells were significantly lower than that in the control group, and the apoptosis level was significantly higher than that in the control group (P < 0.01). The dual luciferase reporter confirmed that TRIAP1 was the target of miR-539, and the expression level of TRIAP1 in 143b and MG63 transfected with miRNA-539 mimics was proved to be significantly lower than that in the control group (P < 0.01).The western blot showed the expression of genes targeted by TRIAP1 was upregulated when the expression of TRIAP1 was downregulated. In vivo, the osteosarcoma growth rate in the miRNA-539 mimics group was significantly slower than that in the control group (P < 0.01).

Conclusions

MiRNA-539 may inhibit the cell proliferation, migration and invasion of osteosarcoma cells and promote the apoptosis of osteosarcoma cells by targeting on TRIAP1.

Abnormal expression of TRIAP1 and its role in gestational diabetes mellitus-related pancreatic β cells

Gestational diabetes mellitus (GDM) is a disease that is typically characterized by insulin resistance and pancreatic β cell dysfunction. Currently, the role of TP53-regulated inhibitor of apoptosis 1 (TRIAP1) in the process of GDM remains to be elucidated. Therefore, the present study investigated the effects of TRIAP1 on GDM-related pancreatic β cells. Reverse transcription-quantitative PCR and western blot assays were conducted to analyze the expression levels of TRIAP1 in the peripheral blood of patients with GDM and subjects with healthy pregnancies. Subsequently, TRIAP1 small interfering RNA (siRNA), control siRNA, TRIAP1 plasmid and control plasmid were transfected into INS-1 cells to assess the effects of TRIAP1 on pancreatic β cells. ELISA was used to assess the total insulin content and insulin secretion of pancreatic β cells. MTT and flow cytometry assays were performed to determine the viability and apoptosis of pancreatic β cells. The results demonstrated that TRIAP1 expression was downregulated in peripheral blood samples from patients with GDM. Transfection with TRIAP1 siRNA significantly decreased the levels of total insulin content and reduced insulin secretion in pancreatic β cells. In addition, downregulation of TRIAP1 in pancreatic β cells significantly induced cell apoptosis and reduced cell viability. Accordingly, transfection of INS1 cells with TRIAP1 siRNA increased the levels of the apoptosis-associated genes apoptotic protease-activating factor 1, caspase-3, caspase-7 and caspase-9. However, transfection of the cells with TRIAP1 plasmid resulted in the opposite effects. TRIAP1 increased the growth of pancreatic β cells and their ability to secrete insulin, thus playing a protective role in GDM. The findings verified the effects and the underlying mechanism of TRIAP1 in pancreatic β cells and may provide additional clinical applications for the therapy of GDM.

Regulation of Apoptosis and Inflammatory Response in Interleukin-1β-Induced Nucleus Pulposus Cells by miR-125b-5p Via Targeting TRIAP1

The aim of the present study was to determine the function of microRNA (miR)-125b-5p in lumbar disc degeneration (LDD). Nucleus pulposus (NP) cells were stimulated with 10 ng/ml IL-1β for 24 h to establish an LDD model. Reverse transcription-quantitative PCR was used to assess miR-125b-5p levels in human lumbar degenerative NP samples and IL-1β-treated NP cells. An interaction between miR-125b-5p and TP53-regulated inhibitor of apoptosis 1 (TRIAP1) was revealed by TargetScan 7.1 and dual-luciferase reporter assay. Protein levels of pro-inflammatory factors were determined using ELISA. Cell viability and apoptosis were evaluated by MTT and flow cytometry analysis, respectively. miR-125b-5p was markedly upregulated in both human lumbar degenerative NP specimens and IL-1β-treated NP cells. TRIAP1, which directly targets miR-125b-5p, was markedly downregulated in human lumbar degenerative NP specimens and IL-1β-treated NP cells. The levels of TNF-α and IL-6 were inhibited in IL-1β-treated NP cells transfected with miR-125b-5p inhibitor. Moreover, miR-125b-5p inhibitor increased NP cell viability, prevented apoptosis and repressed the apoptotic peptidase activating factor 1/caspase 9 pathway in IL-1β-treated NP cells. Thus, the present findings suggested that miR-125b-5p could regulate LDD by adjusting NP cell apoptosis and inflammatory responses via TRIAP1.

TRIAP1 knockdown sensitizes non-small cell lung cancer to ionizing radiation by disrupting redox homeostasis

Background

Radioresistance of some non‐small cell lung cancer (NSCLC) types increases the risk of recurrence or metastasis in afflicted patients, following radiotherapy. As such, further improvements to NSCLC radiotherapy are needed. The expression of oncogene TP53‐regulated inhibitor of apoptosis 1 (TRIAP1) in NSCLC is increased following irradiation. Furthermore, gene set enrichment analysis (GSEA) has suggested that TRIAP1 might be involved in maintaining redox homeostasis. This in turn might enhance cell radioresistance.

Methods

In this study we irradiated human NSCLC cell lines (A549 and H460), while knocking down TRIAP1, to determine whether a disrupted redox homeostasis could attenuate radioresistance.

Results

Irradiation notably increased both mRNA and protein levels of TRIAP1. In addition, TRIAP1 knockdown decreased the expression of several antioxidant proteins, including thioredoxin‐related transmembrane protein (TMX) 1, TMX2, thioredoxin (TXN), glutaredoxin (GLRX) 2, GLRX3, peroxiredoxin (PRDX) 3, PRDX4, and PRDX6 in A549 and H460 cells. In addition, silencing TRIAP1 impaired the radiation‐induced increase of the aforementioned proteins. Continuing along this line, we observed a radiation‐induced reduction of cell viability and invasion, as well as increased apoptosis and intracellular reactive oxygen species following TRIAP1 knockdown.

Conclusions

In summary, we identified TRIAP1 as a key contributor to the radioresistance of NSCLC by maintaining redox homeostasis.

TRIAP1 Inhibition Activates the Cytochrome c/Apaf-1/Caspase-9 Signaling Pathway to Enhance Human Ovarian Cancer Sensitivity to Cisplatin

OBJECTIVE

To investigate whether TRIAP1inhibition affects the ovarian cancer cell resistance to cisplatin (DDP) via the Cyt c/Apaf-1/caspase-9 pathway by in vitro and in vivo experiments.

METHODS

CCK8 assay was performed to find out how treatment with both TRIAP1 siRNA and DDP affects the cell viability of SKOV3 cells and DDP-resistant human ovarian carcinoma cell line SKOV3/DDP. SKOV3/DDP cells were transfected with control siRNA or TRIAP1 siRNA before 24 h of treatment with DDP (5 μg/mL). Flow cytometry was employed to detect cell apoptosis and Western blot to examine the expressions of Cyt c/Apaf-1/caspase-9 pathway-related proteins. SKOV3/DDP cells transfected with control siRNA or TRIAP1 siRNA were subcutaneously injected into BALB/c-nu/nu nude mice followed by the intraperitoneal injection of DDP (4 mg/kg). Cyt c/Apaf-1/caspase-9 pathway in transplanted tumors was detected by immunohistochemistry.

RESULTS

TRIAP1 expression declined in SKOV3 cells when compared with SKOV3/DDP cells. The proliferation rate was lower in SKOV3/DDP cells transfected with TRIAP1 siRNA combined with treatment of DDP (1, 2, 4, 6, 8, 16, 32 μg/mL) than in those transfected with control siRNA. Moreover, the TRIAP1 siRNA group had an increased SKOV3/DDP cell apoptosis rate with the activation of the Cyt c/Apaf-1/caspase-9 pathway. During DDP treatment, nude mice in TRIAP1 siRNA group had slower growth and smaller size of transplanted tumor than those in control siRNA group, with increased expression of Cyt c, Apaf-1, and caspase-9.

CONCLUSION

TRIAP1 inhibition may enhance the sensitivity of SKOV3/DDP cells to cisplatin via activation of the Cyt c/Apaf-1/caspase-9 pathway.

miR-1301/TRIAP1 Axis Participates in Epirubicin-Mediated Anti-Proliferation and Pro-Apoptosis in Osteosarcoma

PURPOSE

Epirubicin is one of the most effective drugs against osteosarcoma. miR-1301 is involved in the occurrence and development of osteosarcoma. Whether miR-1301 is responsible for the chemosensitivity of osteosarcoma cells to epirubicin remains largely unknown.

MATERIALS AND METHODS

U2OS and SAOS-2 cells were treated with various concentrations of epirubicin. Flow cytometry was employed to evaluate cell apoptotic rate. Cell proliferation was measured by Cell Counting Kit-8 assay. Western blot and quantitative real-time polymerase chain reaction were utilized to detect the expressions of B-cell lymphoma-2 (Bcl-2), Bcl-2 assaciated X protein (Bax), cleaved-caspase-3, cleaved-poly (ADP-ribose) polymerases (PARP1), TP53-regulated inhibitor of apoptosis 1 (TRIAP1), and microRNA-1301 (miR-1301). The relationship between miR-1301 and TRIAP1 was determined by luciferase reporter assay.

RESULTS

Epirubicin inhibited proliferation in a dose-dependent manner, induced apoptosis, decreased the expression of Bcl-2, and increased the expressions of Bax, cleaved-caspase-3, and cleaved-PARP1 in osteosarcoma cells. miR-1301 was downregulated in U2OS and SAOS-2 cells. Importantly, epirubicin significantly increased the levels of miR-1301. Overexpression of miR-1301 suppressed proliferation and promoted apoptosis. Interestingly, those effects were enhanced by epirubicin. In contrast, miR-1301 depletion attenuated the epirubicin-mediated anti-osteosarcoma effect. miR-1301 negatively regulated the expression of TRIAP1 in U2OS and SAOS-2 cells. Furthermore, epirubicin inhibited the mRNA and protein levels of TRIAP1 by upregulating miR-1301 levels. Epirubicin suppressed cell proliferation by downregulating TRIAP1.

CONCLUSION

miR-1301 was implicated in the chemosensitivity of osteosarcoma to epirubicin by modulating TRIAP1.

Yiqi Chutan Tang Reduces Gefitinib-Induced Drug Resistance in Non-Small-Cell Lung Cancer by Targeting Apoptosis and Autophagy

High incidence and mortality rates for non-small-cell lung cancer (NSCLC) lead to low survival rates. Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) are commonly first prescribed for NSCLC patients with EGFR mutations. However, most patients with sensitizing EGFR mutations become resistant to EGFR-TKI after 9-13 months treatment. Yiqi Chutan Tang (YQCT) has been prescribed as a treatment to this issue for over 20 years. In this report, high-performance liquid chromatography (HPLC) analysis, flow cytometry, western blot analysis, and functional annotation analysis were applied to uncover the molecular mechanisms of YQCT. Our results show the application of YQCT reduces gefitinib-induced drug resistance, induces slight cell cycle arrest, enhances gefitinib-induced apoptosis, and activates the autophagy. These results indicate that at the molecular level YQCT can reduce drug resistance and improve anti-cancer effects when associated with gefitinib, which could be a result of enhancement of apoptosis and autophagy in the EGFR-TKI resistant cells of NSCLC. This research provides a new treatment strategy for patients with EGFR-TKI resistance in NSCLC. © 2019 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.

Effects of MiR-107 on The Chemo-drug Sensitivity of Breast Cancer Cells

Background

A growing body of evidence indicates that aberrant expression of miR-107 plays a core role in cancers. This study aims to demonstrate the function of miR-107 and its roles in chemo-drug resistance in breast cancer cells.

Methodology

CCK-8 assays were carried out to test the effect of miR-107 mimics on the proliferation of MCF-7 cells. The apoptosis level of each group was detected by flow cytometry. miR-107 level, mRNA levels of Bcl-2/Bax and TRIAP1 were detected by quantitative real-time Polymerase Chain Reaction (qRT-PCR) analysis. Protein levels of Bcl-2/Bax, p-Akt/Akt in MCF-7 cells were detected by using Western Blot. Lastly, the dual luciferase reporter gene assay system was used to confirm interaction between miR-107 and its target gene TRIAP1.

Results

CCK-8 assays indicated that miR-107 mimics augmented Taxol-induced cell viability inhibition. Flow cytometry showed that miR-107 mimics augmented Taxol-induced elevation of cell apoptosis. qRT-PCR analysis revealed that miR-107 mimics inhibited the mRNA expression of Bcl-2 and induced the mRNA level of Bax. Western Blotting indicated that miR-107 mimics inhibited the expression of proteins Bcl-2 and p-Akt, and induced the expression of Bax, while showing no significant effects on Akt. The relative luciferase activity revealed that oncogene TRIAP1 is a potential target gene of miR-107.

Conclusions

miR-107 plays a role in regulating chemo-drug sensitivity in mammary cancer cell by targeting TRIAP1.

miRNA-125a-5p inhibits hepatocellular carcinoma cell proliferation and induces apoptosis by targeting TP53 regulated inhibitor of apoptosis 1 and Bcl-2-like-2 protein

The present study aimed to investigate the role and underlying molecular mechanism of microRNA (miR)-125a-5p in hepatocellular carcinoma. The level of miR-125a-5p was detected using reverse transcription-quantitative polymerase chain reaction. TargetScan was used to investigate the association between miR-125a-5p and TP53-regulated inhibitor of apoptosis 1 (TRIAP1)/B cell lymphoma-2-like 2 protein (BCL2L2). Dual luciferase reporter assay was used to confirm this prediction. To investigate the role of miR-125a-5p in hepatocellular carcinoma (HCC) cells, miR-125a-5p was overexpressed in the human HCC cell line PLC/PRF/5 using miR-125a-5p mimics. Subsequently, cell proliferation, cell apoptosis and cell migration were studied using MTT assay, flow cytometry analysis and Transwell assay, respectively. Protein expression levels in the present study were measured by western blot analysis. Taken together, the present results suggested that miR-125a-5p was markedly downregulated in HCC cells. TRIAP1 and BCL2L2 were direct targets of miR-125a-5p and were upregulated in PLC/PRF/5 cells. miR-125a-5p upregulation inhibited PLC/PRF/5 cell viability and migration and induced cell apoptosis. In addition, miR-125a-5p overexpression increased the expression of caspase9 and apoptotic protease-activating factor 1. Notably, the present study revealed that all the effects on PLC/PRF/5 cells elicited by miR-125a-5p overexpression were eliminated by TRIAP1/BCL2L2 upregulation. In conclusion, miR-125a-5p was shown to be downregulated in hepatocellular carcinoma and its upregulation inhibited hepatocellular carcinoma cell growth and metastasis by targeting TRIAP1 and BCL2L2.

Progression-Related Loss of Stromal Caveolin 1 Levels Mediates Radiation Resistance in Prostate Carcinoma via the Apoptosis Inhibitor TRIAP1

Tumour resistance to chemo- and radiotherapy, as well as molecularly targeted therapies, limits the effectiveness of current cancer treatments. We previously reported that the radiation response of human prostate tumours is critically regulated by CAV1 expression in stromal fibroblasts and that loss of stromal CAV1 expression in advanced tumour stages may contribute to tumour radiotherapy resistance. Here we investigated whether fibroblast secreted anti-apoptotic proteins could induce radiation resistance of prostate cancer cells in a CAV1-dependent manner and identified TRIAP1 (TP53 Regulated Inhibitor of Apoptosis 1) as a resistance-promoting CAV1-dependent factor. TRIAP1 expression and secretion was significantly higher in CAV1-deficient fibroblasts and secreted TRIAP1 was able to induce radiation resistance of PC3 and LNCaP prostate cancer cells in vitro, as well as of PC3 prostate xenografts derived from co-implantation of PC3 cells with TRIAP1-expressing fibroblasts in vivo. Immunohistochemical analyses of irradiated PC3 xenograft tumours, as well as of human prostate tissue specimen, confirmed that the characteristic alterations in stromal-epithelial CAV1 expression were accompanied by increased TRIAP1 levels after radiation in xenograft tumours and within advanced prostate cancer tissues, potentially mediating resistance to radiation treatment. In conclusion, we have determined the role of CAV1 alterations potentially induced by the CAV1-deficient, and more reactive, stroma in radio sensitivity of prostate carcinoma at a molecular level. We suggest that blocking TRIAP1 activity and thus avoiding drug resistance may offer a promising drug development strategy for inhibiting resistance-promoting CAV1-dependent signals.

Proteasome and heat shock protein 70 (HSP70) inhibitors as therapeutic alternative in multiple myeloma

HSP70 connects multiple signaling pathways that work synergistically to protect tumor cells from death by proteotoxic stress and represents a possible target to establish a new approach for multiple myeloma treatment. Therefore, bioluminescent cell lines RPMI8226-LUC-PURO and U266-LUC-PURO were treated with HSP70 (VER155008) and/or proteasome (bortezomib) inhibitors and immunodeficient mice were used for subcutaneous xenograft models to evaluate tumor growth reduction and tumor growth inhibition after treatment. Bioluminescence imaging was used to follow tumor response. Treatment with bortezomib showed ∼60% of late apoptosis in RPMI8226-LUC-PURO (without additional benefit of VER155008 in this cell line). However, U266-LUC-PURO showed ∼60% of cell death after treatment with VER155008 (alone or with bortezomib). RPMI8226-LUC-PURO xenograft presented tumor reduction by bioluminescence imaging after treatment with bortezomib, VER155008 or drug combination compared to controls. Treatment with bortezomib, alone or combined with VER155008, showed inhibition of tumor growth assessed by bioluminescence imaging after one week in both RPMI8226-LUC-PURO and U266-LUC-PURO cell lines when compared to controls. In conclusion, our study shows that the combination of proteasome and HSP70 inhibitors induced cell death in tumor cells in vitro (late apoptosis induction) and in vivo (inhibition of tumor growth) with special benefit in U266-LUC-PURO, bearing 17p deletion.

MiR-107 inhibits proliferation of lung cancer cells through regulating TP53 regulated inhibitor of apoptosis 1 (TRIAP1)

Aims

Accumulating evidence indicates that aberrant expression of miR-107 plays a crucial role in cancers. This study aims to display the function of miR-107 and its novel target genes in the progression of lung cancer.

Methods and Material

MiR-107 or miR-107 inhibitor was transfected into lung cancer cells A549. The levels of miR-107 and TP53 regulated inhibition of apoptosis 1 (TRIAP1) were examined by quantitative real-time Polymerase Chain Reaction (qRT-PCR) analysis and Western Blot. Functionally, MTT and colony formation assays were carried out to test the effect of miR-107 inhibitor and/or small interference RNA (siRNA) targeting TRIAP1 mRNA on proliferation of lung cancer cells. Levels of miR-107 or TRIAP1 were detected in clinical lung cancer samples by using qRT-PCR analysis.

Results

QRT-PCR analysis revealed that miR-107 inhibitor or miR-107 was successfully transfected into A549 cells. Western Blot indicated that miR-107 decreased the expression of TRIAP1 protein in the cells. In contrast, miR-107 inhibitor augmented the levels of TRIAP1 protein. Functionally, miR-107 inhibitor remarkably suppressed A549 cell proliferation, whereas, TRIAP1 siRNAs could abrogate the miR-107 inhibitor-induced proliferation of cells. Then, we validated that TRIAP1 was increased in clinical lung cancer samples. MiR-107 expression was negatively related to TRIAP1 expression in clinical lung cancer samples.

Conclusions

MiR-107 suppresses cell proliferation by targeting TRIAP1 in lung cancer. Our finding allows new insights into the mechanisms of lung cancer that is mediated by miR-107.