MiR-155 inhibits proliferation, invasion and migration of melanoma via targeting CBL.

Objective: Malignant melanoma (MM), the deadliest form of skin malignancy, is a highly aggressive and malignant tumor with an increasing incidence rate in recent years. Increasing evidence suggested that dysfunctions of microRNAs (miRNAs) may play an important role in human tumors. However, the effect of miR-155 on malignant melanoma cell migration and invasion remains largely elusive. This research was designed to evaluate the potential function of miR-155 and CBL (Casitas B-lineage lymphoma) in malignant melanoma.
Patients and Methods: Quantitative Real-time polymerase chain reaction (qRT-PCR) was utilized to detect miR-155 and CBL expression in malignant melanoma tissues and cell lines. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to examine the regulation of miR-155 in melanoma proliferation. Transwell assay was carried out to detect the effect of miR-155 on the MM cell migration and invasion. Luciferase assay and biological analysis were used to predict and determine the target gene of miR-155.
Results: miR-155 was down-regulated in malignant melanoma tissues and cell lines. Ectopic expression of miR-155 could inhibit migration and invasion in malignant melanoma cells. What's more, we found that CBL was a new target of miR-155. Additionally, CBL was negatively associated with miR-155 in malignant melanoma and overexpression of CBL attenuated miR-155-mediated inhibition on MM cell migration and invasion.
Conclusions: miR-155 inhibited malignant melanoma proliferation, migration and invasion. And high CBL expression was observed in MM tissues. This newly identified miR-155/CBL axis may provide new insight into the pathogenesis of malignant melanoma.