CHCHD4-TRIAP1 regulation of innate immune signaling mediates skeletal muscle adaptation to exercise

Exercise training can stimulate the formation of fatty-acid-oxidizing slow-twitch skeletal muscle fibers, which are inversely correlated with obesity, but the molecular mechanism underlying this transformation requires further elucidation. Here, we report that the downregulation of the mitochondrial disulfide relay carrier CHCHD4 by exercise training decreases the import of TP53-regulated inhibitor of apoptosis 1 (TRIAP1) into mitochondria, which can reduce cardiolipin levels and promote VDAC oligomerization in skeletal muscle. VDAC oligomerization, known to facilitate mtDNA release, can activate cGAS-STING/NFKB innate immune signaling and downregulate MyoD in skeletal muscle, thereby promoting the formation of oxidative slow-twitch fibers. In mice, CHCHD4 haploinsufficiency is sufficient to activate this pathway, leading to increased oxidative muscle fibers and decreased fat accumulation with aging. The identification of a specific mediator regulating muscle fiber transformation provides an opportunity to understand further the molecular underpinnings of complex metabolic conditions such as obesity and could have therapeutic implications.

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.

PCGEM1 promotes proliferation, migration and invasion in prostate cancer by sponging miR-506 to upregulate TRIAP1

BACKGROUND

The important role of long noncoding RNAs (lncRNAs) in cancer has been demonstrated in many studies. Prostate cancer gene expression marker 1 (PCGEM1) is a lncRNA specifically expressed within the prostate and overexpressed in many cancer cells. Numerous studies have shown that PCGEM1 promotes cell proliferation, invasion and migration. However, the specific mechanism of PCGEM1 within prostate cancer (PCa) has not been elucidated. MicroRNA-506-3p (miR-506-3p) is a noncoding RNA, and studies have indicated that miR-506-3p is downregulated in prostate cancer cell lines and functions as a tumor suppressor.

METHODS

The TCGA (GEPIA) database ( http://gepia.cancer-pku.cn/ ) was employed to measure PCGEM1 levels in PCa. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the PCGEM1 gene level. CCK-8 (Cell Counting Kit-8) and colony formation assays were used to detect cell proliferation, and Transwell assays were applied to assess cell invasion and migration. The interacting ability of miR-506-3p with PCGEM1 or TRIAP1 was validated through a dual-luciferase reporter assay. TRIAP1 protein expression was detected by Western blotting.

RESULTS

PCGEM1 expression was increased in PCa tissues and cells. In PCa tissues, High PCGEM1 expression was associated with high Gleason score, distant metastasis and extracapsular extension. In addition, PCGEM1 knockdown inhibited PCa cell (C4-2B and PC-3) proliferation, invasion and migration. miR-506-3p may interact with PCGEM1 or TRIAP1, and the suppressive effect of PCGEM1 knockdown was reversed when TRIAP1 or a miR-506-3p inhibitor was cotransfected.

CONCLUSION

PCGEM1 expression increased in PCa cells and tissues, enhancing PCa cell proliferation, migration and invasion by sponging miR-506 to upregulate TRIAP1.

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.

Upregulation of TRIAP1 by the lncRNA MFI2-AS1/miR-125a-5p Axis Promotes Thyroid Cancer Tumorigenesis

Background

Thyroid cancer is a very common endocrine cancer worldwide. How long noncoding RNA (lncRNA) regulates thyroid cancer is elusive. LncRNA MFI2-AS1 has been demonstrated to initiate colorectal cancer. Nevertheless, the role of MFI2-AS1 in thyroid cancer remains unknown. This study aims to determine the roles of MFI2-AS1 in thyroid cancer.

Methods

qRT-PCR was used to determine the expression of MFI2-AS1 in thyroid cancer tissues and cells. Proliferation was determined by using CCK8 and colony formation assays. Transwell assay was utilized to analyze migration and invasion. Luciferase reporter assay was performed to confirm the interaction between MFI2-AS1 and miR-125a-5p.

Results

MFI2-AS1 was shown to be highly expressed in thyroid cancer tissues and predicted poor prognosis. Knockdown of MFI2-AS1 inhibited proliferation, colony formation, migration and invasion of thyroid cancer cells in vitro. Bioinformatics screening identified MFI2-AS1 as the sponge for miR-125a-5p. And miR-125a-5p was further confirmed to target TRIAP1 directly. Our data further demonstrated that MFI2-AS1 promoted TRIAP1 expression via repressing miR-125a-5p. Finally, TRIAP1 was found to be upregulated in thyroid cancer tissues and its restoration reversed the effects of MFI2-AS1 depletion.

Conclusion

Our results elucidated a novel mechanism that MFI2-AS1 promotes thyroid cancer progression via the miR-125a-5p/TRIAP1 pathway.

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.

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.

miR-107 targets TRIAP1 to regulate oral squamous cell carcinoma proliferation and migration

The role of microRNA-107 (miR-107) as a tumor suppressor has been explored in different types of human cancer. However, the expression and role of miR-107 in oral squamous cell carcinoma (OSCC) remains elusive. Here, the expression of miR-107 in OSCC cell lines was explored by reverse transcription-quantitative polymerase chain reaction. Online prediction algorithms and luciferase activity reporter assay were conducted to validate the targets of miR-107. Cell counting kit-8 assay and wound-healing assay were performed to analyze the functions of miR-107 on OSCC cells. These results indicated that miR-107 had reduced expression in OSCC cells. Overexpression of miR-107 inhibits OSCC cell proliferation and migration. It was found that miR-107 directly targets TP53 regulated inhibitor of apoptosis 1 (TRIAP1) to regulate gene expression. Together, these results demonstrated that miR-107 also plays a tumor suppressive role by inhibiting proliferation and migration of OSCC cells by targeting TRIAP1. Our finding provides novel insights into the mechanism of OSCC progression.

MicroRNA-18a inhibits ovarian cancer growth via directly targeting TRIAP1 and IPMK

The role of microRNA-18a (miRNA/miR-18a) as a tumor suppressor or promoter in a number of different types of cancer has been reported. However, to date, the expression and the effects of miR-18a in epithelial ovarian cancer (EOC) remain elusive. In the present study, the expression of miR-18a in patient EOC tissues and ovarian cancer cell lines was investigated using the reverse transcription-quantitative polymerase chain reaction. Luciferase assays and western blotting were performed to detect the potential direct targets of miR-18a. An A2780cp intraperitoneal mouse model, and Cell Counting Kit 8, flow cytometry and terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling assays, were used to investigate the effect of miR-18a on tumor growth in vivo and in vitro. The results indicated that the expression of miR-18a was reduced in EOC tissue and in the investigated ovarian cancer cell lines compared with non-malignant (normal) ovarian tissues and the human ovarian epithelium cell line, respectively. Overexpression of miR-18a in the A2780s and A2780cp cell lines significantly induced cell cycle arrest and apoptosis. It was demonstrated that miR-18a directly targets tumor protein p53-regulating inhibitor of apoptosis gene 1 and inositol phosphate multikinase, hence regulating the expression of downstream targets. The A2780cp intraperitoneal mouse model was employed and the results indicated that miR-18a may inhibit A2780cp intraperitoneal tumor growth in vivo by inhibiting proliferation and inducing apoptosis. Together, the results of the present study demonstrated that miR-18a has a role as a tumor suppressor by inhibiting proliferation and inducing apoptosis. Assessment of miR-18a expression may provide a novel method for diagnosis and be a therapeutic target for EOC.