Mechanistic modeling of the effects of myoferlin on tumor cell invasion

Abstract

Myoferlin (MYOF) is a member of the evolutionarily conserved ferlin family of proteins, noted for their role in a variety of membrane processes, including endocytosis, repair, and vesicular transport. Notably, ferlins are implicated in Caenorhabditis elegans sperm motility (Fer-1), mammalian skeletal muscle development and repair (MYOF and dysferlin), and presynaptic transmission in the auditory system (otoferlin). In this paper, we demonstrate that MYOF plays a previously unrecognized role in cancer cell invasion, using a combination of mathematical modeling and in vitro experiments. Using a real-time impedance-based invasion assay (xCELLigence), we have shown that lentiviral-based knockdown of MYOF significantly reduced invasion of MDA-MB-231 breast cancer cells in Matrigel bioassays. Based on these experimental data, we developed a partial differential equation model of MYOF effects on cancer cell invasion, which we used to generate mechanistic hypotheses. The mathematical model predictions revealed that matrix metalloproteinases (MMPs) may play a key role in modulating this invasive property, which was supported by experimental data using quantitative RT-PCR screens. These results suggest that MYOF may be a promising target for biomarkers or drug target for metastatic cancer diagnosis and therapy, perhaps mediated through MMPs.cancer invasion | RNAi | partial differential equation models | metastasis A majority of cancer deaths are related not to the primary tumor itself, but rather the formation of disseminated metastases (1). Cancer spread requires that cells achieve atypical motility, which enables them to invade surrounding tissues and vessels of the blood and lymphatic systems (2-4). Thus, understanding the mechanisms and signaling processes that lead to invasive cell behavior may lead to new therapeutic approaches for controlling and treating cancer.The fundamental mechanisms of invasive cancer cell movement are largely conserved across a wide range of cell types, with some of the protease dependent and protease independent movement types demonstrated by cancer cells also seen in organisms as diverse as unicellular organisms, slime molds, and white blood cells. The ferlin family is an evolutionarily ancient family of proteins (5), which are known to affect processes crucial to migration and invasion, including membrane fusion and repair, vesicle transport, endocytosis, protein recycling and stability, and cell motility (6-13). Thus, one might expect the ferlin family to be good candidates for cancer proteins, although they have not previously been investigated in this capacity. In Caenorhabditis elegans, spermatozoa exhibit amoeboid movement, and mutations in the fer-1 gene [an orthologue of myoferlin (MYOF)] result in immobility and infertility (13). In humans, MYOF has been implicated in a variety of cellular processes, including myoblast fusion, growth factor receptor stability, endocytosis, and endothelial cell membrane repair (6,8,(10)(11)(12); however until now its role in cancer cell movement ha...

Myoferlin Is a Key Regulator of EGFR Activity in Breast Cancer

“…Interestingly, Li and colleagues (14) and Eisenberg and colleagues (13) both showed that short hairpin RNA (shRNA)-mediated myoferlin depletion impairs MDA-MB231 cells' invasion; however, it has no effect on cell migration or proliferation. Our invasion and proliferation data are in agreement with the literature (13,14). However, opposite to the previous findings (13,14), we show that myoferlin silencing exhibits a strong inhibitory effect on the ability of MDA-MB231 cells to migrate.…”

“…In normal myoblasts, Demonbreun and colleagues showed that myoferlin deficiency leads to a defect in insulin growth factor-like receptor (IGFR1) trafficking as well as to decreased IGFR1 signaling (12). Although increasing number of studies continue to further our understanding of myoferlin function in normal cells, to date, only little (13)(14)(15) is known concerning its role in tumor cells. Three previous studies have reported the overexpression of myoferlin at the mRNA level in lung (16) and breast cancer (17) as well as at the protein level in pancreas cancer (18).…”

Expression Profiling of a Human Thyroid Cell Line Stably Expressing the BRAFV600E Mutation

“…The impedance data, reported as cell index and proportional to the area of the bottom electrodes covered by migrated/invasive cells, were collected every 15 min. The percentage of invasion was calculated as the ratio between the invasive cells and the migrated cells (8).…”

Myoferlin plays a key role in VEGFA secretion and impacts tumor‐associated angiogenesis in human pancreas cancer

“…Recently, myoferlin was found to be important for breast cancer invasion. [13][14][15] Our laboratory showed that myoferlin, is a key regulator of EGFR activity in human breast cancer cells. 16 Interestingly, it was reported, in a Kaplan-Meier survival curve, that patients with myoferlin-positive PDAC had a significant lower overall survival than those with a myoferlinnegative tumor.…”