Proteomics analysis: inhibiting the expression of P62 protein by chloroquine combined with dacarbazine can reduce the malignant progression of uveal melanoma

Abstract

Background Although uveal melanoma (UM) at the early stage is controllable to some extent, it inevitably ultimately leads to death due to its metastasis. At present, the difficulty is that there is no way to effectively tackle the metastasis. It is hypothesized that these will be treated by target molecules, but the recognized target molecule has not yet been found. In this study, the target molecule was explored through proteomics. Methods Transgenic enhanced green fluorescent protein (EGFP) inbred nude mice, which spontaneously display a tumor microenvironment (TME), were used as model animal carriers. The UM cell line 92.1 was inoculated into the brain ventricle stimulating metastatic growth of UM, and a graft re-cultured Next, the UM cell line 92.1-A was obtained through monoclonal amplification, and a differential proteomics database, between 92.1 and ectopic 92.1-A, was established. Finally, bioinformatics methodologies were adopted to optimize key regulatory proteins, and in vivo and in vitro functional verification and targeted drug screening were performed. Results Cells and tissues displaying green fluorescence in animal models were determined as TME characteristics provided by hosts. The data of various biological phenotypes detected proved that 92.1-A were more malignant than 92.1. Besides this malignancy, the key protein p62 (SQSTM1), selected from 5267 quantifiable differential proteomics databases, was a multifunctional autophagy linker protein, and its expression could be suppressed by chloroquine and dacarbazine. Inhibition of p62 could reduce the malignancy degree of 92.1-A. Conclusions As the carriers of human UM orthotopic and ectopic xenotransplantation, transgenic EGFP inbred nude mice clearly display the characteristics of TME. In addition, the p62 protein optimized by the proteomics is the key protein that increases the malignancy of 92.1 cells, which therefore provides a basis for further exploration of target molecule therapy for refractory metastatic UM.

Integrative analyses of a mitophagy-related gene signature for predicting prognosis in patients with uveal melanoma

“…Our results also showed the high expression of PGAM5 and SQSTM1 in the high immune-level and high-risk groups. Another study further validated that the high expression of SQSTM1 was a high-risk factor for the lowest survival rate of UM patients ( Fei et al, 2022 ). Given this, our results are reproducible and reliable and the mitophagy-related role of PGAM5 and SQSTM1 are worth being investigated in future studies.…”

Autophagy impairment in human bile duct carcinoma cells

“…We also show significant increase of p62 transcripts in melanoma and thymoma patients (Figure 1) confirming that p62 increase may represent a feature present in different solid and hematologic cancers. Remarkably, p62 is a diagnostic biomarker for early stage melanomas (Tang et al, 2016) and p62 is emerging as a possible therapeutic target in melanoma (Karras et al, 2019;Fei et al, 2022). Further, high p62 expression in lymphoma shows significant positive correlation with disease relapse (Kyriazopoulou et al, 2022).…”

Quantitative proteomic dataset of whole protein in three melanoma samples of 92.1, 92.1-A and 92.1-B

“…After 14 days, the cells were placed into a new culture flask. The limiting dilution method was used to repeatedly perform monoclonal subculture [6] .…”

“…According to these data, bioinformatics analyses of proteins were performed, including functional classification, protein annotation, cluster analysis and functional enrichment. A total of 22 kinesins underwent initial analysis, of which P62 (Sequestosome 1, SQSTM 1) was validated via animal models [6] .

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