Sorcin induces gastric cancer cell migration and invasion contributing to STAT3 activation

Gastric cancer (GC) is a globally occurring malignancy that is characterized by a high mortality rate due to a high tendency to metastasize and poor prognoses. Sorcin, as known as SRI, a soluble resistance-related calcium-binding protein, plays a significant role in multidrug resistance. Sorcin is related to the migration and invasion of cancer cells. However, the mechanism remains unclear. Here, we used immunohistochemistry to confirm that the expression of sorcin in cancer tissues is higher than that in the adjacent normal tissues. The wound healing and transwell results indicate that sorcin can induce migration and invasion of GC cells. To explore the role of sorcin in GC metastasis, isobaric tags for relative and absolutely quantitation (iTRAQ) were used to examine cells with and without sorcin knockdown to identify the differentially expressed proteins (DEPs). The results were evaluated via RT-PCR and western blot to confirm the ITRAQ data. Inhibition of sorcin expression can down- regulate the expression of CTSZ, MMP2, MMP9 and p-STAT3 followed by suppression of tumor growth and metastasis. Together, we concluded that sorcin has a oncogenic activity via inducing tumor growth and metastasis, leading to development of therapeutic treatments for GC.