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Melanoma is a life-threatening disease due to the early onset of metastasis and frequent resistance to the applied treatment. For now, no single histological, immunohistochemical or serological biomarker was able to provide a precise predictive value for the aggressive behavior in melanoma patients. Thus, the search for quantifying methods allowing a simultaneous diagnosis and prognosis of melanoma patients is highly desirable. By investigating specific molecular interactions with some biosensor-based techniques, one can determine novel prognostic factors for this tumor. In our previous study, we have shown the possibility of a qualitative in vitro distinguishing the commercially available melanoma cells at different progression stages based on the measurements of the lectin Concanavalin A interacting with surface glycans present on cells. Here, we present the results of the quantitative diagnostic and prognostic study of both commercial and patient-derived melanoma cells based on the evaluation of two novel factors: lectin affinity and glycan viscoelastic index obtained from the quartz crystal microbalance with dissipation monitoring (QCM-D) measurements. Two approaches to the QCM-D measurements were applied, the first uses the ability of melanoma cells to grow as a monolayer of cells on the sensor (cell-based sensors), and the second shortens the time of the analysis (suspension cell based-sensors). The results were confirmed by the complementary label-free (atomic force microscopy, AFM; and surface plasmon resonance, SPR) and labeling (lectin-ELISA; and microscale thermophoresis, MST) techniques. This new approach provides additional quantitative diagnosis and a personalized prognosis which can be done simultaneously to the traditional histopathological analysis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The viscoelastic properties of cells are responsible for the adhesion process to different surfaces and for cell motility. Therefore, it is very important to develop specific, label-free biosensors with the use of whole cells to study the effect of various factors on the survival and properties of selected type of normal and pathological cells. The quartz crystal microbalance with dissipation energy monitoring (QCM-D) is a technique which enables to track these changes in cells during real-time experiments. One of the applied procedures of the evaluation of the cells' viscoelastic changes is based on the investigations of interactions between specific, different glycans, present on the surface of the primary tumor and its metastases with specific lectins. Two procedures have been developed to detect the differences in the cellular glycosylation profile using cell-based sensors (adherent cells cultured on sensors) and suspension cell-based sensors (adherent cells mechanically detached and inserted into the QCM-D chamber with a sensor). Furthermore, in this work some cell-based sensor regeneration protocols have been described and a lectin-ELISA assay with a fluorescently labeled lectin, thus enabling a qualitative and quantitative tracking of each step of the lectin-glycan binding and unbinding process performed on whole cells., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

Malignant melanoma is one of the most dangerous skin cancer originating from melanocytes. Thus, an early and proper melanoma diagnosis influences significantly the therapy efficiency. The melanoma recognition is still difficult, and generally, relies on subjective assessments. In particular, there is a lack of quantitative methods used in melanoma diagnosis and in the monitoring of tumour progression. One such method can be the atomic force microscopy (AFM) working in the force spectroscopy mode combined with quartz crystal microbalance (QCM), both applied to quantify the molecular interactions. In our study we have compared the recognition of mannose type glycans in melanocytes (HEMa-LP) and melanoma cells originating from the radial growth phase (WM35) and from lung metastasis (A375-P). The glycosylation level on their surfaces was probed using lectin concanavalin A (Con A) from Canavalia ensiformis. The interactions of Con A with surface glycans were quantified with both AFM and QCM techniques that revealed the presence of various glycan structural groups in a cell-dependent manner. The Con A - mannose (or glucose) type glycans present on WM35 cell surface are rather short and less ramified while in A375-P cells, Con A binds to long, branched mannose and glucose types of oligosaccharides., (Copyright © 2016 Elsevier B.V. All rights reserved.)