Characterization of Cystatin B interactome, a prognostic marker for oral cancer

Author(s)

Guilherme Araújo Câmara

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2022-04-20

Examining board members

Adriana Franco Paes Leme; Alexandre Keiji Tashima; Leonardo dos Reis Silveira

• Advisor: Adriana Franco Paes Leme

Abstract

Proteins perform their functions through a dynamic interaction network with other proteins, and it is known that the tridimensional structure of proteins and protein complexes are closely related to its function. Therefore, the characterization of a protein interaction network, also known as its interactome, may reveal significant aspects about biological and pathological processes in which the target protein participates. On this matter, Carnielli et al (2018) showed that lower protein levels of cystatin B (CSTB) are associated with a worst prognostic of oral squamous cell carcinoma (OSCC) patients. However, little is known about its interactome on OSCC and, consequently, its role on the development of the disease. Here, we proposed the characterization of CSTB interaction networks in a reductionist model of OSCC, composed of OSCC cell lines of different levels of aggressivity, where its levels of CSTB expression and abundance correspond to those observed previously in different areas of patient tissues, such as invasive tumor front and inner tumor. In this study, the selection of HMK (normal control), SCC25 and HSC3 (OSCC) cell lines was realized by the levels of CSTB expression through quantitative reverse transcription polymerase chain reaction (RT-qPCR). Right after selection, we developed a strategy based on the application of affinity purification (AP) followed by crosslinking reagent (XL) in large scale and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), in order to characterize CSTB interactome. Our data lead to the identification of 77 proteins exclusively in OSCC cell lines (SCC25 and HSC3), in addition to the identification of the proteins TMIGD1, SMARCE1, KANSL1L, LMNTD1 and SLC25A6 as potential CSTB interaction partners in OSCC. Collectively, these results lead to a better understanding of signaling pathways in which CSTB may participate in OSCC, favoring the development of new therapeutical strategies (AU)

• FAPESP's process: 19/14828-7 - Quantitative targeted proteomics by target LC-MS (SRM) to determine the ligands and interaction interface of cystatin B complex, a prognostic marker for oral cancer
• Grantee: Guilherme Araújo Câmara
• Support Opportunities: Scholarships in Brazil - Master