Protein Disulfide Isomerase 4 Drives Docetaxel Resistance in Prostate Cancer

Molecular panorama of therapy resistance in prostate cancer: a pre-clinical and bioinformatics analysis for clinical translation

Prostate cancer (PCa) is a malignant disorder of prostate gland being asymptomatic in early stages and high metastatic potential in advanced stages. The chemotherapy and surgical resection have provided favourable prognosis of PCa patients, but advanced and aggressive forms of PCa including CRPC and AVPC lack response to therapy properly, and therefore, prognosis of patients is deteriorated. At the advanced stages, PCa cells do not respond to chemotherapy and radiotherapy in a satisfactory level, and therefore, therapy resistance is emerged. Molecular profile analysis of PCa cells reveals the apoptosis suppression, pro-survival autophagy induction, and EMT induction as factors in escalating malignant of cancer cells and development of therapy resistance. The dysregulation in molecular profile of PCa including upregulation of STAT3 and PI3K/Akt, downregulation of STAT3, and aberrant expression of non-coding RNAs are determining factor for response of cancer cells to chemotherapy. Because of prevalence of drug resistance in PCa, combination therapy including co-utilization of anti-cancer drugs and nanotherapeutic approaches has been suggested in PCa therapy. As a result of increase in DNA damage repair, PCa cells induce radioresistance and RelB overexpression prevents irradiation-mediated cell death. Similar to chemotherapy, nanomaterials are promising for promoting radiosensitivity through delivery of cargo, improving accumulation in PCa cells, and targeting survival-related pathways. In respect to emergence of immunotherapy as a new tool in PCa suppression, tumour cells are able to increase PD-L1 expression and inactivate NK cells in mediating immune evasion. The bioinformatics analysis for evaluation of drug resistance-related genes has been performed.

Protein disulfide isomerase family member 4 promotes triple-negative breast cancer tumorigenesis and radiotherapy resistance through JNK pathway

BACKGROUND

Despite radiotherapy ability to significantly improve treatment outcomes and survival in triple-negative breast cancer (TNBC) patients, acquired resistance to radiotherapy poses a serious clinical challenge. Protein disulfide isomerase exists in endoplasmic reticulum and plays an important role in promoting protein folding and post-translational modification. However, little is known about the role of protein disulfide isomerase family member 4 (PDIA4) in TNBC, especially in the context of radiotherapy resistance.

METHODS

We detected the presence of PDIA4 in TNBC tissues and paracancerous tissues, then examined the proliferation and apoptosis of TNBC cells with/without radiotherapy. As part of the validation process, xenograft tumor mouse model was used. Mass spectrometry and western blot analysis were used to identify PDIA4-mediated molecular signaling pathway.

RESULTS

Based on paired clinical specimens of TNBC patients, we found that PDIA4 expression was significantly higher in tumor tissues compared to adjacent normal tissues. In vitro, PDIA4 knockdown not only increased apoptosis of tumor cells with/without radiotherapy, but also decreased the ability of proliferation. In contrast, overexpression of PDIA4 induced the opposite effects on apoptosis and proliferation. According to Co-IP/MS results, PDIA4 prevented Tax1 binding protein 1 (TAX1BP1) degradation by binding to TAX1BP1, which inhibited c-Jun N-terminal kinase (JNK) activation. Moreover, PDIA4 knockdown suppressed tumor growth xenograft model in vivo, which was accompanied by an increase in apoptosis and promoted tumor growth inhibition after radiotherapy.

CONCLUSIONS

The results of this study indicate that PDIA4 is an oncoprotein that promotes TNBC progression, and targeted therapy may represent a new and effective anti-tumor strategy, especially for patients with radiotherapy resistance.

Protein disulfide-isomerase A4 confers glioblastoma angiogenesis promotion capacity and resistance to anti-angiogenic therapy

Introduction

Increasing evidence has revealed the key activity of protein disulfide isomerase A4 (PDIA4) in the endoplasmic reticulum stress (ERS) response. However, the role of PDIA4 in regulating glioblastoma (GBM)-specific pro-angiogenesis is still unknown.

Methods

The expression and prognostic role of PDIA4 were analyzed using a bioinformatics approach and were validated in 32 clinical samples and follow-up data. RNA-sequencing was used to search for PDIA4-associated biological processes in GBM cells, and proteomic mass spectrum (MS) analysis was used to screen for potential PDIA4 substrates. Western blotting, real-time quantitative polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assays (ELISA) were used to measure the levels of the involved factors. Cell migration and tube formation assays determined the pro-angiogenesis activity of PDIA4 in vitro. An intracranial U87 xenograft GBM animal model was constructed to evaluate the pro-angiogenesis role of PDIA4 in vivo.

Results

Aberrant overexpression of PDIA4 was associated with a poor prognosis in patients with GBM, although PDIA4 could also functionally regulate intrinsic GBM secretion of vascular endothelial growth factor-A (VEGF-A) through its active domains of Cys-X-X-Cys (CXXC) oxidoreductase. Functionally, PDIA4 exhibits pro-angiogenesis activity both in vitro and in vivo, and can be upregulated by ERS through transcriptional regulation of X-box binding protein 1 (XBP1). The XBP1/PDIA4/VEGFA axis partially supports the mechanism underlying GBM cell survival under ER stress. Further, GBM cells with higher expression of PDIA4 showed resistance to antiangiogenic therapy in vivo.

Conclusions

Our findings revealed the pro-angiogenesis role of PDIA4 in GBM progression and its potential impact on GBM survival under a harsh microenvironment. Targeting PDIA4 might help to improve the efficacy of antiangiogenic therapy in patients with GBM.

Identification of Prognostic and Predictive Biomarkers and Druggable Targets among 205 Antioxidant Genes in 21 Different Tumor Types via Data-Mining

(1) Background: Oxidative stress is crucial in carcinogenesis and the response of tumors to treatment. Antioxidant genes are important determinants of resistance to chemotherapy and radiotherapy. We hypothesized that genes involved in the oxidative stress response may be valuable as prognostic biomarkers for the survival of cancer patients and as druggable targets. (2) Methods: We mined the KM Plotter and TCGA Timer2.0 Cistrome databases and investigated 205 antioxidant genes in 21 different tumor types within the context of this investigation. (3) Results: Of 4347 calculations with Kaplan-Meier statistics, 84 revealed statistically significant correlations between high gene expression and worse overall survival (p < 0.05; false discovery rate ≤ 5%). The tumor types for which antioxidant gene expression was most frequently correlated with worse overall survival were renal clear cell carcinoma, renal papillary cell carcinoma, and hepatocellular carcinoma. Seventeen genes were clearly overexpressed in tumors compared to their corresponding normal tissues (p < 0.001), possibly qualifying them as druggable targets (i.e., ALOX5, ALOX5AP, EPHX4, G6PD, GLRX3, GSS, PDIA4, PDIA6, PRDX1, SELENOH, SELENON, STIP1, TXNDC9, TXNDC12, TXNL1, TXNL4A, and TXNRD1). (4) Conclusions: We concluded that a sub-set of antioxidant genes might serve as prognostic biomarkers for overall survival and as druggable targets. Renal and liver tumors may be the most suitable entities for this approach.

Lin-28 Homolog B-Activated Protein Disulfide Isomerase A4 Regulates Cell Proliferation, Migration and Invasion of Glioma

The goal of this study is to elucidate the role of protein disulfide isomerase A4 (PDIA4) in glioma, as well as its regulatory mechanism. Cell transfection was performed to adjust the expression level of PDIA4 and RNA-binding protein lin-28 homolog B (LIN28B). The expression of PDIA4 in human astrocytes and glioma cell lines was determined by quantitative real-time PCR and western blot. CCK-8, colony formation, Transwell and wound-healing assays were applied to determine the capabilities of cells to proliferate, invade and migrate. The connection between PDIA4 and LIN28B was demonstrated by RNA immunoprecipitation (RIP) and RNA pull down assays. As a result, PDIA4 was elevated in glioma. PDIA4 depletion hugely suppressed cell proliferative ability, which was characterized by the reduced cell viability and colony formation, and declined contents of PCNA and Ki67. Meanwhile, PDIA4 knockdown repressed the cell capabilities to migrate and invade, accompanied with downregulated MMP2 and MMP9. LIN28N was also found to be upregulated in glioma cells, and was verified to bind with PDIA4 and positively regulate PDIA4 expression. Additionally, LIN28B overexpression partly hindered the suppressive impacts of PDIA4 knockdown on cell abilities to proliferate, migrate and invade. In conclusion, this study delineates that LIN28B-mediated PDIA4 plays a critical role in the progression of glioma.

High expression of PDIA4 promotes malignant cell behavior and predicts reduced survival in cervical cancer

The protein disulfide isomerase (PDI) gene family plays important roles in the maintenance of several cellular functions. Previous studies have showed that protein disulfide isomerase family A member 4 (PDIA4) is aberrantly expressed in several types of cancer, and correlates with prognosis of patients. However, the role of PDIA4 in cervical cancer remains unclear. In the present study, the expression pattern of PDIA4 from both public database and immunohistochemical analysis in cervical samples was analyzed. Cell Counting Kit-8 and Transwell assays were performed to determine the effect of PDIA4 on cervical cancer cell proliferation and migration. Gene set enrichment analysis (GSEA) was used to provide the associated enriched pathways of PDIA4 in regulating cervical tumorigenesis. It was observed that mRNA expression and protein level of PDIA4 were upregulated in cervical cancer tissues. High expression of PDIA4 was significantly associated with poor overall survival (P=0.0095) and relapse-free survival (P=0.0019) in The Cancer Genome Atlas cohort. Knockdown of PDIA4 inhibited cervical cancer cell proliferation and migration. Moreover, PDIA4 affected the expression of proliferation-related molecules (cyclin D1 and PCNA) and migration-related molecules (E-cadherin and Vimentin). Additionally, GSEA revealed that PDIA4 was significantly associated with gene signatures involving glycan biosynthesis, glycosaminoglycan degradation and protein export. In conclusion, the present findings highlighted the importance of PDIA4 in cervical oncogenesis, and suggested that targeting PDIA4 may be a potential therapeutic application for cervical cancer.