Two-dimensional gel electrophoresis analysis of the leiomyoma interstitial fluid reveals altered protein expression with a possible involvement in pathogenesis

Abstract

Abstract. Uterine leiomyoma is the most common smooth benign neoplasm. In the present study, we analyzed the global interstitial fluid (IF) profile of leiomyoma vs. normal myometrium to identify protein dysregulation involved in leiomyoma pathogenesis. Two-dimensional gel electrophoresis and mass spectrometry were used to generate and compare the global interstitial fluid profiles of the leiomyoma and of the normal tissue. Two proteins were validated by immunohistochemistry. By comparing the interstitial fluid profile of the leiomyoma with that of the normal myometrium, the levels of seven proteins were found to be significantly different: four structural organization proteins (desmin, prelamin-A/C, transgelin and α-actinin-1), an inflammatory response (α1-antitrypsin), a response to oxidative stress (peroxiredoxin-2), and a folding protein (heat shock 70 kDa protein 1A/1B). Desmin, α1-antitrypsin and peroxiredoxin-2 were upregulated in the leiomyoma, whereas heat shock 70 kDa protein 1A/1B, α-actinin-1, prelamin-A/C and transgelin were downregulated. Desmin and α1-antitrypsin were further validated by immunohistochemistry. By identifying proteins with altered expression levels compared to the myometrium from several pathways of the leiomyoma pathogenesis, we found the leiomyoma interstitial fluid to have a characteristic proteomic profile. A better appreciation of the pathophysiology of the disease can be useful in the development of conservative treatments that serve as viable alternatives to hysterectomy.

Identification of proteins with different abundance associated with cell migration and proliferation in leiomyoma interstitial fluid by proteomics

“…These proteins were identified by MALDI-TOF/TOF and database search against the human section of the UniProt database (version 20150401; 90,411 sequences) ( Table I). In addition, proteins reported in our previous study, including desmin (DES), transgelin (TAGLN), serpin family A member 1 (SERPINA1), lamin A/C (LMNA), actinin α1 (ACTN1), PRDX2 and heat shock protein family A (Hsp70) member 1A (HSPA1A), were also identified (14). Of these proteins, TAGLN, PRDX2 and HSPA1A were significant, while DES, SERPINA1 (more abundant in the leiomyoma compared with in the myometrium), LMNA and ACTN1 (less abundant in the leiomyoma compared with in the myometrium) were not significant, and thus were not investigated further.…”

“…Our previous proteomic studies on leiomyoma tissue identified several dysregulated proteins involved in metabolic processes, oxidative stress and cell migration (12,13). In a previous study, seven proteins with changes in abundance were identified in the IF of leiomyomas (14). To date, no other proteomic study has been conducted on the IF of leiomyomas.…”

“…The IF was obtained as previously described (14,15). Two samples (300 mg each) were collected from each patient: One from the unaffected myometrium and one from the central area of the leiomyoma.…”

Abnormal expression of leiomyoma cytoskeletal proteins involved in cell migration

“…The uterine leiomyoma consists mainly of smooth muscle cells with abundant expression of DES (19). The overexpression of desmin inside and outside of the cell certainly indicates its involvement in the mechanotransduction and in tumor development (10).…”

“…Several factors can induce alterations in the mechanotransduction signal from ECM via the transmembrane receptor to the interior of the cell (10). This signal causes the reorganization of the actin cytoskeleton, mediated by RHOA, inducing cell proliferation (11).…”