Can a simple proteomics urine test assist in the early diagnosis of early-stage cancer?

MALDI-TOF/MS Analysis of Non-Invasive Human Urine and Saliva Samples for the Identification of New Cancer Biomarkers

Cancer represents a group of heterogeneous diseases that are a leading global cause of death. Even though mortality has decreased in the past thirty years for different reasons, most patients are still diagnosed at the advanced stage, with limited therapeutic choices and poor outcomes. Moreover, the majority of cancers are detected using invasive painful methods, such as endoscopic biopsy, making the development of non-invasive or minimally invasive methods for the discovery and fast detection of specific biomarkers a crucial need. Among body fluids, a valuable non-invasive alternative to tissue biopsy, the most accessible and least invasive are undoubtedly urine and saliva. They are easily retrievable complex fluids containing a large variety of endogenous compounds that may provide information on the physiological condition of the body. The combined analysis of these fluids with matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF/MS), a reliable and easy-to-use instrumentation that provides information with relatively simple sample pretreatments, could represent the ideal option to rapidly achieve fast early stage diagnosis of tumors and their real-time monitoring. On this basis, the present review summarizes the recently reported applications relevant to the MALDI analysis of human urine and saliva samples.

[Research Progress of Raman Spectroscopy in the Diagnosis of Early Lung Cancer]

Lung cancer (LC) is the most common cancer and the leading cause of cancer-related death worldwide. The 5-year survival rate for LC remains low at 18% and is 5% for patients with metastatic disease, while the 5-year overall survival rate of patients with stage I NSCLC can reach 77.9%, hence early diagnosis and treatment of LC is the key to improve the prognosis. As a non-invasive detection technique, Raman spectroscopy can realize the non-destructive detection of the differences in molecular level structure between cancerous tissues and normal tissues, which can be used for the early diagnosis of lung cancer. The aim of this review is to summarize the progress of Raman spectroscopycombined with different tissue or body fluid samplesin the diagnosis of early LC.
.

Mup-knockout mice generated through CRISPR/Cas9-mediated deletion for use in urinary protein analysis

Major urinary proteins (MUPs) are the most abundant protein species in mouse urine, accounting for more than 90% of total protein content. Twenty-one Mup genes and 21 pseudogenes are clustered in a region of around 2 megabase pairs (Mbp) on chromosome 4. A Mup-knockout mouse model would greatly facilitate researches in the field of proteomic analysis of mouse urine. Here, we report the successful knockout of the Mup gene cluster of 2.2 Mbp using the CRISPR/Cas9 system. Homozygous Mup-knockout mice survived to adulthood and exhibited no obvious defects. The patterns of the proteomes of non-MUP urinary proteins in homozygous Mup-knockout mice were similar to those of wild-type mice judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The sensitivity of enzyme-linked immunosorbent assay to detect non-MUP urinary protein was significantly enhanced in Mup-knockout mice. In short, we have developed a Mup-knockout mouse model. This mouse model will be useful for the research of urinary biomarker testing that may have relevance for humans.

Identification of urine protein biomarkers with the potential for early detection of lung cancer

Lung cancer is the leading cause of cancer-related deaths and has an overall 5-year survival rate lower than 15%. Large-scale clinical trials have demonstrated a significant relative reduction in mortality in high-risk individuals with low-dose computed tomography screening. However, biomarkers capable of identifying the most at-risk population and detecting lung cancer before it becomes clinically apparent are urgently needed in the clinic. Here, we report the identification of urine biomarkers capable of detecting lung cancer. Using the well-characterized inducible Kras (G12D) mouse model of lung cancer, we identified alterations in the urine proteome in tumor-bearing mice compared with sibling controls. Marked differences at the proteomic level were also detected between the urine of patients and that of healthy population controls. Importantly, we identified 7 proteins commonly found to be significantly up-regulated in both tumor-bearing mice and patients. In an independent cohort, we showed that 2 of the 7 proteins were up-regulated in urine samples from lung cancer patients but not in those from controls. The kinetics of these proteins correlated with the disease state in the mouse model. These tumor biomarkers could potentially aid in the early detection of lung cancer.

Glycosylation of uroplakins. Implications for bladder physiopathology

Urothelium, a specialized epithelium, covers the urinary tract and act not only as a barrier separating its light from the surrounding tissues, but fulfills an important role in maintaining the homeostasis of the urothelial tract and well-being of the whole organism. Proper function of urothelium is dependent on the precise assemble of highly specialized glycoproteins called uroplakins, the end products and differentiation markers of the urothelial cells. Glycosylation changes in uroplakins correlate with and might reflect progressive stages of pathological conditions of the urothelium such as cancer, urinary tract infections, interstitial cystitis and others. In this review we focus on sugar components of uroplakins, their emerging role in urothelial biology and disease implications. The advances in our understanding of uroplakins changes in glycan moieties composition, structure, assembly and expression of their glycovariants could potentially lead to the development of targeted therapies and discoveries of novel urine and plasma markers for the benefit of patients with urinary tract diseases.