Comparison of tear protein levels in breast cancer patients and healthy controls using a de novo proteomic approach

Abstract

Noninvasive biomarkers are urgently needed for early detection of breast cancer since the risk of recurrence, morbidity and mortality are closely related to disease stage at the time of primary surgery. In the past decade, many proteomics-based approaches were developed that utilize the protein profiling of human body fluids or identification of putative biomarkers to obtain more knowledge on the effects of cancer emergence and progression. Herein, we report on an analysis of proteins in the tear fluid from breast carcinoma patients and healthy women using a de novo proteomic approach and 25 mixed samples from each group. This study included 25 patients with primary invasive breast carcinoma and 25 age-matched healthy controls. We performed a MALDI-TOF-TOF-driven semi-quantitative comparison of tear protein levels in cancer (CA) and control (CTRL) using a de novo approach in pooled samples. Over 150 proteins in the tear fluid of CTRL and CA were identified. Using an in-house-developed algorithm we found more than 20 proteins distinctly upregulated or downregulated in the CTRL and CA groups. We identified several proteins that had modified expression in breast cancer patients. These proteins are involved in host immune system pathways (e.g., C1Q1 or S100A8) and different metabolic cascades (ALDH3A or TPI). Further validation of the results in an independent population combined with individual protein profiling of participants is needed to confirm the specificity of our findings and may lead to a better understanding of the pathological mechanism of breast cancer.

Precise quantitation of 136 urinary proteins by LC/MRM-MS using stable isotope labeled peptides as internal standards for biomarker discovery and/or verification studies

“…Cancer is becoming increasingly prevalent in modern society [1,2]. While cardiovascular disease and lung/breast cancer are typically the most commonly discussed, cancers that affect proximal tissues of the urinary tract system (which includes the kidneys, ureters, bladder, prostate, and urethra) are also widespread [3].…”

Tear Fluid Protein Biomarkers

“…Using SELDI-TOF-MS technique, Lebrecht et al found a breast cancer diagnostic biomarker from an identified panel consisting of 20 m/z in tears, which allowed breast cancer patients to be differentiated from healthy women with a successful detection rate of 71% [108]. Among these, six proteins (cystatin-SA, 5-AMP-activated protein kinase subunit gamma-3, triosephosphate isomerase, microtubule-associated tumor suppressor 1, transferrin receptor protein 1, and putative lipocalin 1-like protein 1) showed !4 times higher abundance in breast cancer patients than controls, and three proteins (DNA damage-binding protein 1, protein S100-A9, and GTP-binding protein Di-Ras2) showed !4 times lower levels in breast cancer [77]. Among these, six proteins (cystatin-SA, 5-AMP-activated protein kinase subunit gamma-3, triosephosphate isomerase, microtubule-associated tumor suppressor 1, transferrin receptor protein 1, and putative lipocalin 1-like protein 1) showed !4 times higher abundance in breast cancer patients than controls, and three proteins (DNA damage-binding protein 1, protein S100-A9, and GTP-binding protein Di-Ras2) showed !4 times lower levels in breast cancer [77].…”

“…For example, the most recent study has detected around 1500 protein species in tears using offline strong cation exchange fractionation (SCX) followed by nanoreverse-phase liquid chromatography (nano-RPLC) coupled to Triple TOF 5600 MS [68]. Studies of the tear proteome have found that it can reflect both local eye diseases [73,74] and systemic diseases such as diabetes [75] and cancer [76,77]. Its protein content is 10 times less than plasma, which is estimated to contain up to 10,000 proteins [69,70], and it contains a higher protein concentration with less interfering compounds than urine.…”

Biomarker sources for Parkinson's disease: Time to shed tears?

“…in systemic diseases like diabetes (diabetic retinopathy, DR) [67], SS [68] and cancer [69] as well as ocular diseases like glaucoma [70], dry eye syndrome (DES) [71] and rosacea [59].…”

“…For example, a biomarker can indicate a change in expression or state of a protein that correlates with the risk or progression of a Basal Ganglia 5 (2015) [63][64][65][66][67][68][69] Parkinson's disease (PD) is the most frequent neurodegenerative movement disorder. In nearby future its importance will increase, especially due to changes in age structure.…”