Characterization and transcriptional regulation analysis of the porcine PAQR6 gene

Genome-wide siRNA screening reveals several host receptors for the binding of human gut commensal Bifidobacterium bifidum

Bifidobacterium spp. are abundant gut commensals, especially in breast-fed infants. Bifidobacteria are associated with many health-promoting effects including maintenance of epithelial barrier and integrity as well as immunomodulation. However, the protective mechanisms of bifidobacteria on intestinal epithelium at molecular level are poorly understood. In this study, we developed a high-throughput in vitro screening assay to explore binding receptors of intestinal epithelial cells for Bifidobacterium bifidum. Short interfering RNAs (siRNA) were used to silence expression of each gene in the Caco-2 cell line one by one. The screen yielded four cell surface proteins, SERPINB3, LGICZ1, PKD1 and PAQR6, which were identified as potential receptors as the siRNA knock-down of their expression decreased adhesion of B. bifidum to the cell line repeatedly during the three rounds of siRNA screening. Furthermore, blocking of these host cell proteins by specific antibodies decreased the binding of B. bifidum significantly to Caco-2 and HT29 cell lines. All these molecules are located on the surface of epithelial cells and three out of four, SERPINB3, PKD1 and PAQR6, are involved in the regulation of cellular processes related to proliferation, differentiation and apoptosis as well as inflammation and immunity. Our results provide leads to the first steps in the mechanistic cascade of B. bifidum-host interactions leading to regulatory effects in the epithelium and may partly explain how this commensal bacterium is able to promote intestinal homeostasis.

Copy Number Variations of CEP63, FOSL2 and PAQR6 Serve as Novel Signatures for the Prognosis of Bladder Cancer

Background

Finding effective prognostic signatures is of great urgency due to the high risk of recurrence and progression of bladder cancer (BC). Although a lot of genetic alterations are involved in the carcinogenesis, none of them were referred in the current risk group stratifications. In this study, we aimed to find significant copy number variations (CNVs) to predict prognosis for BC patients.

Methods

CNVs with high aberration frequencies in BC were explored by array-based comparative genomic hybridization in 65 tumor samples. Candidates were validated in independent groups of BC tumor samples (n=219) and urine samples (n=123). 3D digital PCR was applied for detecting accurate gene copy numbers in BC urine. In order to explore the prognostic value of candidate CNVs, all enrolled patients were followed up for the disease-free survival (DFS). Cox proportional hazards regression analysis was performed to find the independent prognostic factors for DFS.

Results

CNVs of CEP63, FOSL2 and PAQR6 with high aberration frequencies (67.7%, 56.9% and 60.0%, respectively) were found in BC tumors. Copy numbers of CEP63, FOSL2 and PAQR6 were gained in 219 tumor samples. CNVs of CEP63 and FOSL2 were correlated with advanced tumor stage and high grade. Retrospective analysis (median follow-up time: 69 months) revealed that CNVs of CEP63 and FOSL2 were independent prognostic factors for DFS of non-muscle-invasive bladder cancer (NMIBC) patients, while CNVs of FOSL2 and PAQR6 were independent prognostic factors for DFS of muscle-invasive bladder cancer (MIBC) patients. Models for predicting DFS were constructed based on CNVs of three genes. Patients with high prognostic indexes tended to have poor DFS. Prognostic index can also help to identify those with worse outcomes among high risk NMIBC patients. Copy number gains of CEP63 and FOSL2 in urine were found to be significantly correlated with poor DFS of NMIBC patients.

Conclusions

CNVs of CEP63, FOSL2 and PAQR6 were capable of predicting DFS and may serve as promising signatures for prognosis of BC.

PAQR6 Expression Enhancement Suggests a Worse Prognosis in Prostate Cancer Patients

OBJECTIVE

This study aimed to evaluate the expression of progestin and adipoQ receptor family member VI (PAQR6, mPRδ) in prostate cancer and to explore its role in prostate cancer progression.

METHODS

PAQR6 mRNA expression was evaluated based on the data obtained from the TCGA database and the GEO database. The prognostic value of PAQR6 was explored by Kaplan-Meier analysis. To investigate the role of PAQR6, it was depleted by siRNA in DU145 cells. The effects of depleting PAQR6 on DU145 cell viability and migration were determined by CCK8 assay, colony formation assay, and wound healing assay, respectively. The activation of MEK and ERK were analyzed by western blot.

RESULTS

PAQR6 mRNA expression was significantly up-regulated in prostate cancer tissues and correlated with lower survival rates (p=0.014). Furthermore, qPCR revealed that PAQR6 expression was elevated in DU145 and LNCaP cells compared with RWPE-2 cells. Depleting PAQR6 obviously suppressed DU145 cell proliferation and migration (p<0.01). In addition, the ratio of p-MEK/MEK and p-ERK/ERK was significantly reduced after silencing PAQR6 (p<0.01).

CONCLUSION

PAQR6 might play a facilitating role in prostate cancer development by regulating the MAPK signaling pathway. Moreover, it might serve as a potential predictor and therapeutic target in prostate cancer.

Identification and Analysis of Regulatory Elements in Porcine Bone Morphogenetic Protein 15 Gene Promoter

Bone morphogenetic protein 15 (BMP15) is secreted by the mammalian oocytes and is indispensable for ovarian follicular development, ovulation, and fertility. To determine the regulation mechanism of BMP15 gene, the regulatory sequence of porcine BMP15 was investigated in this study. The cloned BMP15 promoter retains the cell-type specificity, and is activated in cells derived from ovarian tissue. The luciferase assays in combination with a series of deletion of BMP15 promoter sequence show that the -427 to -376 bp region of BMP15 promoter is the primary regulatory element, in which there are a number of transcription factor binding sites, including LIM homeobox 8 (LHX8), newborn ovary homeobox gene (NOBOX), and paired-like homeodomain transcription factor 1 (PITX1). Determination of tissue-specific expression reveals that LHX8, but not PITX1 and NOBOX, is exclusively expressed in pig ovary tissue and is translocated into the cell nuclei. Overexpression of LHX8 in Chinese hamster ovary (CHO) cells could significantly promote BMP15 promoter activation. This study confirms a key regulatory element that is located in the proximal region of BMP15 promoter and is regulated by the LHX8 factor.