CIAPIN1 gene silencing enhances chemosensitivity in a drug-resistant animal model in vivo

The regulation of microRNAs on chemoresistance in triple-negative breast cancer: a recent update

Triple-negative breast cancer (TNBC) has negative expressions of ER, PR and HER2. Due to the insensitivity to both endocrine therapy and HER2-targeted therapy, the main treatment method for TNBC is cytotoxic chemotherapy. However, the curative effect of chemotherapy is limited because of the existence of acquired or intrinsic multidrug resistance. MicroRNAs (miRNAs) are frequently dysregulated in malignant tumors and involved in tumor occurrence and progression. Interestingly, growing studies show that miRNAs are involved in chemoresistance in TNBC. Thus, targeting dysregulated miRNAs could be a plausible way for better treatment of TNBC. Here, we present the updated knowledge of miRNAs associated with chemoresistance in TNBC, which may be helpful for the early diagnosis, prognosis and treatment of this life-threatening disease.

Prediction of CIAPIN1 (Cytokine-Induced Apoptosis Inhibitor 1) Signaling Pathway and Its Role in Cholangiocarcinoma Metastasis

Cholangiocarcinoma (CCA), a malignancy of the biliary epithelium, can arise at any point in the biliary system. We previously reported that CIAPIN1 is detectable in the sera and that its overexpression was associated with poor prognosis and metastasis of CCA patients. In this study, we investigated further its expression in CCA tissues, biological functions, and related signaling pathways in CCA cells. First, we examined CIAPIN1 expression in CCA tissues of 39 CCA patients using immunohistochemistry (IHC). Then, CIAPIN1-related proteins expressed in CCA cells were identified using RNA interference (siRNA) and liquid chromatography–mass spectrometry (LC–MS/MS). To predict the functions and signaling pathways of CIAPIN1 in CCA cells, the identified proteins were analyzed using bioinformatics tools. Then, to validate the biological functions of CIAPIN1 in the CCA cell line, transwell migration/invasion assays were used. CIAPIN1 was overexpressed in CCA tissues compared with adjacent noncancerous tissues. Its overexpression was correlated with lymph node metastasis. Bioinformatic analyses predicted that CIAPIN1 is connected to the TGF-β/SMADs signaling pathway via nitric oxide synthase 1 (NOS1) and is involved in the metastasis of CCA cells. In fact, cell migration and invasion activities of the KKU-100 CCA cell line were significantly suppressed by CIAPIN1 gene silencing. Our results unravel its novel function and potential signaling pathway in metastasis of CCA cells. CIAPIN1 can be a poor prognostic factor and can be a promising target molecule for CCA chemotherapy.

Cytokine-induced apoptosis inhibitor 1 (CIAPIN1) accelerates vascular remodelling via p53 and JAK2-STAT3 regulation in vascular smooth muscle cells

BACKGROUND AND PURPOSE

Abnormal vascular smooth muscle cell (VSMC) proliferation and migration lead to neointima formation, which eventually results in cardiovascular hyperplastic diseases. The molecular mechanisms underlying these cellular processes have not been fully understood. Cytokine-induced apoptosis inhibitor 1 (CIAPIN1) has been identified as an anti-apoptotic molecule, but little is known about its target genes and related pathways in VSMC dysfunction or its clinical implication in neointima formation following vascular injury.

EXPERIMENTAL APPROACH

Determination, using loss/gain-of-function approaches by gene delivery, of whether CIAPIN1 modulates VSMC proliferation, migration and neointima formation and the underlying mechanisms was carried out. Balloon injury or ligation and local delivery of lentivirus were performed on rat or mouse carotid arteries. Rat aortic smooth muscle cells, the primary cell, was used as the model to evaluate the effect of CIAPIN1 on proliferation and migration.

KEY RESULTS

CIAPIN1 was overexpressed in the neointimal region of rat arteries. CIAPIN1 deficiency markedly inhibited injury-induced or ligation-induced intimal hyperplasia and suppressed PDGF-BB-induced VSMC proliferation, migration and cell cycle progression, while overexpression promoted proliferation, migration and neointima formation. CIAPIN1 negatively regulated Tp53 transcription, which promoted cell cycle progression and migration via cyclin E1-CDK2/pRb/PCNA and the MMP2 pathway. CIAPIN1 also increased JAK2 expression, enhancing JAK2 and STAT3 phosphorylation by vascular injury, which forced phenotypic switching from contractile to synthetic state in injured arteries.

CONCLUSIONS AND IMPLICATIONS

These findings provide new insights into the mechanism by which CIAPIN1 regulates vascular remodelling and suggest a novel therapeutic target for treating vascular proliferative diseases.

Hsa-miRNA-143-3p Reverses Multidrug Resistance of Triple-Negative Breast Cancer by Inhibiting the Expression of Its Target Protein Cytokine-Induced Apoptosis Inhibitor 1 In Vivo

PURPOSE

Multidrug resistance (MDR) remains a major obstacle in the treatment of triple-negative breast cancer (TNBC) with conventional chemotherapeutic agents. A previous study demonstrated that hsa-miRNA-143-3p plays a vital role in drug resistance of TNBC. Downregulation of hsa-miRNA-143-3p upregulated the expression of its target protein cytokine-induced apoptosis inhibitor 1 (CIAPIN1) in order to activate MDR, while upregulation of hsa-miRNA-143-3p effectively enhances the sensitivity of drug-resistant TNBC cells to chemotherapeutics. The present study aimed to further verify these findings in vivo.

METHODS

We established a hypodermic tumor nude mice model using paclitaxel-resistant TNBC cells. We expressed ectopic hsa-miRNA-143-3p under the control of a breast cancer-specific human mammaglobin promoter that guided the efficient expression of exogenous hsa-miRNA-143-3p only in breast cancer cells. Thereafter, we overexpressed hsa-miRNA-143-3p in xenografts using a recombinant virus system and quantified the expression of hsa-miRNA-143-3p, CIAPIN1 protein, and proteins encoded by related functional genes by western blot.

RESULTS

We successfully completed the prospective exploration of the intravenous virus injection pattern from extensive expression to targeted expression. The overexpression of hsa-miRNA-143-3p significantly alleviated chemoresistance of TNBC by inhibiting viability. In addition, we observed that the expression of CIAPIN1 as a hsa-miRNA-143-3p target protein was remarkably decreased.

CONCLUSION

We partly illustrated the mechanism underlying the hsa-miRNA-143-3p/CIAPIN1 drug resistance pathway. HsamiRNA-143-3p as a tumor suppressive microRNA may be a novel target to effectively reverse MDR of TNBC in vivo.

Upregulation of microRNA-143 reverses drug resistance in human breast cancer cells via inhibition of cytokine-induced apoptosis inhibitor 1

Cytokine-induced apoptosis inhibitor 1 (CIAPIN1), originally termed anamorsin, is an anti-apoptotic molecule that acts as a downstream effector of the receptor tyrosine kinase-Ras signaling pathway. Overexpression of CIAPIN1 contributes to multidrug resistance (MDR) and microRNA (miR)-143 is typically considered a tumor suppressor in breast cancer. The present study aimed to evaluate the therapeutic potential of miR-143 as a treatment for drug-resistant breast cancer via the downregulation of CIAPIN1 in vitro. The expression levels of miR-143 were measured using quantitative polymerase chain reaction and the expression levels of CIAPIN1 were detected via western blot analysis. Bioinformatic analyses was additionally conducted to search for miR-143, which may potentially target CIAPIN1. Luciferase reporter plasmids were created and used to verify direct targeting. In addition, Taxol-induced drug-resistant (TDR) breast cancer cell proliferation was evaluated using the Cell Counting Kit-8 assay in vitro. The present study identified an inverse association between miR-143 and CIAPIN1 protein expression levels in breast cancer MCF-7, MDA-MB-231 and MDA-MB-453 TDR cells. Specific targeting sites for miR-143 in the 3′-untranslated region of the CIAPIN1 gene were identified, which exhibit the ability to regulate CIAPIN1 expression. It was revealed that the repression of CIAPIN1 via miR-143 suppressed the proliferation of breast cancer TDR cells. The findings of the present study verified the role of miR-143 as a tumor suppressor in breast cancer MDR via inhibition of CIAPIN1 translation.

Mammalian drug efflux transporters of the ATP binding cassette (ABC) family in multidrug resistance: A review of the past decade

Multidrug resistance (MDR) is a serious phenomenon employed by cancer cells which hampers the success of cancer pharmacotherapy. One of the common mechanisms of MDR is the overexpression of ATP-binding cassette (ABC) efflux transporters in cancer cells such as P-glycoprotein (P-gp/ABCB1), multidrug resistance-associated protein 2 (MRP2/ABCC2), and breast cancer resistance protein (BCRP/ABCG2) that limits the prolonged and effective use of chemotherapeutic drugs. Researchers have found that developing inhibitors of ABC efflux transporters as chemosensitizers could overcome MDR. But the clinical trials have shown that most of these chemosensitizers are merely toxic and only show limited or no benefits to cancer patients, thus new inhibitors are being explored. Recent findings also suggest that efflux pumps of the ABC transporter family are subject to epigenetic gene regulation. In this review, we summarize recent findings of the role of ABC efflux transporters in MDR.