Low Expression of Protocadherin-8 Promotes the Progression of Ovarian Cancer

MicroRNA-124-3p inhibited progression of nasopharyngeal carcinoma by interaction with PCDH8 and the inactivation of PI3K/AKT/mTOR pathway

Nasopharyngeal carcinoma (NPC) is characterised by distinct geographical distribution and is particularly prevalent in Asian countries. But the mechanisms related to the progression of nasopharyngeal carcinoma (NPC) are not completely understood. MiR-124-3p functions as a tumor suppressor in many kinds of human cancers. Here, we explored the effects and mechanism of miR-124-3p on the proliferation and colony formation in NPC. In our study, we reported that miR-124-3p was significantly downregulated in NPC tissues and cell lines. Overexpression miR-124-3p decreased NPC cell proliferation and colony formation abilities. Meanwhile, knockdown miR-124-3p increased proliferation and colony formation abilities. Additionally, dual-luciferase assay showed that miR-124-3p could positively regulated PCDH8 by targeting its 3'-UTR. Overexpression of PCDH8 could partially rescue the proliferation and colony formation role of miR-124-3p inhibitor. Our study indicated that miR-124-3p played a tumor suppressor by directly interacting with PCDH8 and inhibiting the activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. Overall, we found that miR-124-3p inhibited the activation of the PI3K/AKT/mTOR signaling pathway in NPC by interacting with PCDH8. Thus, PCDH8 may be a potential molecular target that impeded NPC proliferation and colony formation.

Research Progress in Prognostic Factors and Biomarkers of Ovarian Cancer

Ovarian cancer is a serious threat to women's health; its early diagnosis rate is low and prone to metastasis and recurrence. The current conventional treatment for ovarian cancer is a combination of platinum and paclitaxel chemotherapy based on surgery. The recurrence and progression of ovarian cancer with poor prognosis is a major challenge in treatment. With rapid advances in technology, understanding of the molecular pathways involved in ovarian cancer recurrence and progression has increased, biomarker-guided treatment options can greatly improve the prognosis of patients. This review systematically discusses and summarizes existing and new information on prognostic factors and biomarkers of ovarian cancer, which is expected to improve the clinical management of patients and lead to effective personalized treatment.

Do Protocadherins Show Prognostic Value in the Carcinogenesis of Human Malignant Neoplasms? Systematic Review and Meta-Analysis

Background:

Protocadherins (PCDHs) have been reported as tumor suppressor genes, implying that these genes may be involved in tumor suppression in a variety of cancers. However, a thorough understanding of the functions and mechanisms of PCDHs remains limited. Our aim was to investigate the methylation profile of PCDHs in human malignant neoplasms.

Methods:

This systematic review has been recorded in PROSPERO (#42019117844) and conducted according to PRISMA’s checklist; search was conducted in LILACS, PubMed, Science Direct, Scopus, and Web of Science databases, manually, with search queries and without date or language restrictions.

Results:

We found 91 articles, of which 26 were used for this meta-analysis and categorized according to the origin of the neoplasia. In total, 3,377 cases were compiled, with PCDH10, PCDH17, and PCDH8 being the most studied; males were 2.22 times more affected than females. Studies have shown significant heterogeneity (p <0.001), with the odds ratio varying between cases and controls [2.20 (95% CI = 1.11– 4.35) to 209.05 (95% CI = 12.64– 2,457.18)], and the value of association between methylation and cancers studied was 26.08 (95% CI = 15.42–44.13).

Conclusion:

In this systematic review, we have demonstrated using meta-analysis that PCDHs could emerge as potential tumor suppressor genes and that a significant increase in methylation may be useful for early detection of different cancers. This work may help in the identification of new prognostic biomarkers in malignant neoplasms.

Proximity-dependent Proteomics Reveals Extensive Interactions of Protocadherin-19 with Regulators of Rho GTPases and the Microtubule Cytoskeleton

Protocadherin-19 belongs to the cadherin family of cell surface receptors and has been shown to play essential roles in the development of the vertebrate nervous system. Mutations in human Protocadherin-19 (PCDH19) lead to PCDH19 Female-limited epilepsy (PCDH19 FLE) in humans, characterized by the early onset of epileptic seizures in children and a range of cognitive and behavioral problems in adults. Despite being considered the second most prevalent gene in epilepsy, very little is known about the intercellular pathways in which it participates. In order to characterize the protein complexes within which Pcdh19 functions, we generated Pcdh19-BioID fusion proteins and utilized proximity-dependent biotinylation to identify neighboring proteins. Proteomic identification and analysis revealed that the Pcdh19 interactome is enriched in proteins that regulate Rho family GTPases, microtubule binding proteins and proteins that regulate cell divisions. We cloned the centrosomal protein Nedd1 and the RacGEF Dock7 and verified their interactions with Pcdh19 in vitro. Our findings provide the first comprehensive insights into the interactome of Pcdh19, and provide a platform for future investigations into the cellular and molecular biology of this protein critical to the proper development of the nervous system.

Protocadherin 8 (PCDH8) Inhibits Proliferation, Migration, Invasion, and Angiogenesis in Esophageal Squamous Cell Carcinoma

BACKGROUND Protocadherin 8 (PCDH8) functions as a tumor-suppressor gene in many types of cancer. This study aimed to investigate the role of PCDH8 in esophageal squamous cell carcinoma (ESCC). MATERIAL AND METHODS Cell proliferation, apoptosis, transwell assay, tube formation assays, and tumor xenograft experiment were performed to explore the role of PCDH8 in the progression of ESCC. RESULTS PCDH8 was found to be downregulated in ESCC cells. Ectopic expression of PCDH8 blocked proliferation, invasion, and migration and induced apoptosis in ESCC cells. Furthermore, vascular endothelial growth factor A (VEGFA) secretion and the AKT signaling pathway were also inhibited when PCDH8 was upregulated. PCDH8 overexpression suppressed epithelial-mesenchymal transition (EMT) and pro-angiogenic activity of ESCC cells. In a mouse model of ESCC xenograft tumors, PCDH8 overexpression remarkably restrained tumor cell growth, with the tumor inhibition rate of 75.2%. PCDH8 was the target of miR-200c and had a negative correlation with miR-200c. CONCLUSIONS PCDH8 exerts a tumor-suppressive effect against ESCC cells. However, further studies are required to elucidate the exact molecular mechanism underlying the antitumor activity of PCDH8 in ESCC.

High Expression of RING Finger Protein 126 Predicts Unfavorable Prognosis of Epithelial Ovarian Cancer

Background

Ovarian cancer (OC) is one of the leading causes of cancer-related mortality worldwide. The clinical outcome of EOC remains unsatisfactory with current therapeutic approaches such as surgery and platinum/taxane-based chemotherapy. Therefore, novel prognostic markers and personalized therapies targeting specific molecules are urgently needed. Here, we explored whether RNF126, an E3 ubiquitin ligase, is a potential biomarker for epithelial ovarian cancer (EOC).

Material/Methods

This was a retrospective cohort study of 122 EOC patients. The chi-square test was used to assess correlations between RNF126 level and clinical characteristics of enrolled patients. Univariate and multivariate analyses were performed to monitor the prognosis of enrolled patients. In addition, proliferation and invasion assays were conducted to assess the cellular effects of RNF126 on SKOV3 cell progression.

Results

Immunohistochemistry analysis (IHC) revealed that RNF126 was upregulated in EOC tissues compared to adjacent ovarian tissues. In addition, RNF126 expression was remarkably associated with LN metastasis, pathological differentiation, and FIGO stage. RNF126 protein level was found to be an independent biomarker for predication of prognosis in ovarian cancer patients. Cellular results showed that RNF126 enhanced the proliferation and invasion abilities of SKOV3 cells.

Conclusions

Upregulated protein level of RNF126 in EOC tissues is a biomarker predicting poor outcomes of EOC patients.