gp78 is specifically expressed in human prostate cancer rather than normal prostate tissue

Autocrine motility factor receptor promotes the malignancy of glioblastoma by regulating cell migration and invasion

OBJECTIVE

One of the important causes of death in cancer patients is malignant metastasis, invasion, and metastasis of tumor cells. Metastasis is also the most basic physiological characteristics and pathogenesis of various tumors. Previously published studies have suggested that autocrine motor factor receptor (AMFR) is the key regulator of tumor cell migration and invasion. Meanwhile, AMFR is highly expressed in esophageal tumors, gastrointestinal tumors, and bladder cancer, and it is also involved in its pathogenesis. However, the role of AMFR in glioblastoma has not been reported.

METHODS

In order to study the role of AMFR in the cell migration and invasion of glioblastoma, AMFR was silenced using siRNA and overexpressed using cDNA. Immunoblotting analysis and real-time quantitative polymerase chain reaction (PCR) were employed to assess the expression of AMFR. We conducted wound healing assay, cell migration assay, and tumorsphere formation assay to detect the invasion and metastatic ability of glioblastoma.

RESULTS

This study found that the level of AMFR expression was significantly correlated with the malignant degree of glioma tissue in clinic samples. AMFR silencing decreased cell migration and invasion of LN229. Overexpression of AMFR significantly increased cell migration and invasion of U251.

CONCLUSION

This study suggests that AMFR could be used as a therapeutic strategy for the clinical treatment of glioblastoma.

Expression of autocrine motility factor receptor (AMFR) in human breast and lung invasive micropapillary carcinomas

The aim of this study was to evaluate the clinicopathological significance of autocrine motility factor receptor (AMFR) expression in a variety of human invasive micropapillary carcinomas (IMPC). AMFR expression was compared in 111 samples of a variety of human IMPCs which had intrinsic non-micropapillary components and with 26 cases of control pulmonary adenocarcinoma (CPA, carcinoma without an IMPC component) by immunohistochemistry (IHC). In the 137 cases analysed, AMFR expression was significantly elevated in the IMPC components compared to the non-IMPC components (p = .005) and normal tissues (p < .001). AMFR expression was also higher in the IMPC samples compared to their intrinsic non-IMPC components (p = .0234). Between the 69 cases of lung IMPC and 26 cases of CPA, AMFR expression was notably higher in the IMPC components than in the CPA components (p = .0455). However, there was no significant difference between the non-IMPC components in the lung and the CPA components (p = .4584). Moreover, in breast cancer, elevated AMFR expression was not significantly correlated with mixed type or pure type IMPC (p = .5969) or with age, gender, T stage, or lymph node metastasis (LNM). Between IMPC and CPA of the lung, there was no statistical significance in age, T stage, and LNM, where AMFR expression was higher in IMPC (p = .0071). Thus this study demonstrated that AMFR was overexpressed in a variety of human IMPC components compared with non-micropapillary components. This suggests that AMFR expression is a potential new prognostic indicator for different types of human IMPC, which might thus be a new therapeutic target.

Divergent Modulation of Proteostasis in Prostate Cancer

Proteostasis regulates key cellular processes such as cell proliferation, differentiation, transcription, and apoptosis. The mechanisms by which proteostasis is regulated are crucial and the deterioration of cellular proteostasis has been significantly associated with tumorigenesis since it specifically targets key oncoproteins and tumor suppressors. Prostate cancer (PCa) is the second most common cause of cancer death in men worldwide. Androgens mediate one of the most central signaling pathways in all stages of PCa via the androgen receptor (AR). In addition to their regulation by hormones, PCa cells are also known to be highly secretory and are particularly prone to ER stress as proper ER function is essential. Alterations in various complex signaling pathways and cellular processes including cell cycle control, transcription, DNA repair, apoptosis, cell adhesion, epithelial-mesenchymal transition (EMT), and angiogenesis are critical factors influencing PCa development through key molecular changes mainly by posttranslational modifications in PCa-related proteins, including AR, NKX3.1, PTEN, p53, cyclin D1, and p27. Several ubiquitin ligases like MDM2, Siah2, RNF6, CHIP, and substrate-binding adaptor SPOP; deubiquitinases such as USP7, USP10, USP26, and USP12 are just some of the modifiers involved in the regulation of these key proteins via ubiquitin-proteasome system (UPS). Some ubiquitin-like modifiers, especially SUMOs, have been also closely associated with PCa. On the other hand, the proteotoxicity resulting from misfolded proteins and failure of ER adaptive capacity induce unfolded protein response (UPR) that is an indispensable signaling mechanism for PCa development. Lastly, ER-associated degradation (ERAD) also plays a crucial role in prostate tumorigenesis. In this section, the relationship between prostate cancer and proteostasis will be discussed in terms of UPS, UPR, SUMOylation, ERAD, and autophagy.

Gp78 E3 Ubiquitin Ligase: Essential Functions and Contributions in Proteostasis

As per the requirement of metabolism and fitness, normal cellular functions are controlled by several proteins, and their interactive molecular and signaling events at multiple levels. Protein quality control (PQC) mechanisms ensure the correct folding and proper utilization of these proteins to avoid their misfolding and aggregation. To maintain the optimum environment of complex proteome PQC system employs various E3 ubiquitin ligases for the selective degradation of aberrant proteins. Glycoprotein 78 (Gp78) is an E3 ubiquitin ligase that prevents multifactorial deleterious accumulation of different misfolded proteins via endoplasmic reticulum-associated degradation (ERAD). However, the precise role of Gp78 under stress conditions to avoid bulk misfolded aggregation is unclear, which can act as a crucial resource to establish the dynamic nature of the proteome. Present article systematically explains the detailed molecular characterization of Gp78 and also addresses its various cellular physiological functions, which could be crucial to achieving protein homeostasis. Here, we comprehensively represent the current findings of Gp78, which shows its PQC roles in different physiological functions and diseases; and thereby propose novel opportunities to better understand the unsolved questions for therapeutic interventions linked with different protein misfolding disorders.

Trends in Gene Expression Profiling for Prostate Cancer Risk Assessment: A Systematic Review

Objectives

The aim of the study is to review biotechnology advances in gene expression profiling on prostate cancer (PCa), focusing on experimental platform development and gene discovery, in relation to different study designs and outcomes in order to understand how they can be exploited to improve PCa diagnosis and clinical management.

Methods

We conducted a systematic literature review on gene expression profiling studies through PubMed/MEDLINE and Web of Science between 2000 and 2016. Tissue biopsy and clinical gene profiling studies with different outcomes (e.g., recurrence, survival) were included.

Results

Over 3,000 papers were screened and 137 full-text articles were selected. In terms of technology used, microarray is still the most popular technique, increasing from 50 to 70% between 2010 and 2015, but there has been a rise in the number of studies using RNA sequencing (13% in 2015). Sample sizes have increased, as well as the number of genes that can be screened all at once, but we have also observed more focused targeting in more recent studies. Qualitative analysis on the specific genes found associated with PCa risk or clinical outcomes revealed a large variety of gene candidates, with a few consistent cross-studies.

Conclusions

The last 15 years of research in gene expression in PCa have brought a large volume of data and information that has been decoded only in part, but advancements in high-throughput sequencing technology are increasing the amount of data that can be generated. The variety of findings warrants the execution of both validation studies and meta-analyses. Genetic biomarkers have tremendous potential for early diagnosis of PCa and, if coupled with other diagnostics (e.g., imaging), can effectively be used to concretize less-invasive, personalized prediction of PCa risk and progression.