Cystatin C and lactoferrin concentrations in biological fluids as possible prognostic factors in eye tumor development

Abstract

ObjectivesTo investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development.BackgroundThe increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population). Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors.Study designA total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment). Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied.MethodsCystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia); lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia).ResultsCystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors.ConclusionIncreased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate between malignant and benign eye tumors. Similar changes were noted for lactoferrin in tear fluid.

Unraveling the molecular repertoire of tears as a source of biomarkers: Beyond ocular diseases

“…Lactoferrin level in tear fluid of healthy subjects was significantly higher than its serum level. Lactoferrin concentration in tear fluid was noted significantly increased in patients with benign and malignant ETs .…”

“…Lactoferrin level in tear fluid of healthy subjects was significantly higher than its serum level. Lactoferrin concentration in tear fluid was noted significantly increased in patients with benign and malignant ETs [91]. Lebrecht et al highlight a biomarker panel in tear fluid to allow breast cancer (BC) patients to be discriminated from healthy women.…”

Clinical Role, Diagnostic and Prognostic Value of Human Cystatin C Through the Body

“…Among the Cystatin human type 2 superfamily, Cystatin C is the most studied 8 . Cystatin C is a natural inhibitor of the enzymes involved in the processing of prohormones and proenzymes and also in the catabolism of different peptides and proteins; it has a generally protective function, to prevent connective tissue destruction by intracellular enzymes which are secreted or leaked from the lysosomes of dying or diseased cells 1 3 9 .…”

“…The main functions of Cystatins are related to the inhibition of cysteine proteases, cell proliferation, cell migration and cell differentiation 8 . Cystatin C inhibits family C1 cysteine proteases through tight and reversible binding in a substrate-competing mechanism, resulting in an equimolar complex with the protease 7 .Cystatin C has been suggested to be a protective protein and prevents brake down of the extracellular matrix by preventing enzymatic cleavage of connective tissues by cathepsins 2 .…”

“…At birth, Cystatin C concentration is higher than in adults and decreases within 2 months; it is also known that Cystatin C does not cross the placenta 5 . Increased Cystatin C level has been found in the serum of patients with several inflammatory diseases, such as tumors with metastases 8 . Cystatin C could play a protective and regulatory role under inflammatory conditions 3 .…”