Silencing of STRN4 suppresses the malignant characteristics of cancer cells.
Bottom Line: We previously reported that STRN4 directly associated with protein kinases, such as MINK1, TNIK and MAP4K4, which are associated with tumor suppression or tumor progression.However, it remains unclear whether STRN4 is associated with tumor progression.Our results demonstrate a possible role of STRN4 in tumor progression.
Affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.Show MeSH
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Mentions: We next investigated the growth of STRN4 knockdown cells in mice using shRNA-expressing KP4 cells. shCtrl and shSTRN4-1 KP4 cells were injected s.c. into the femoral area of nude mice, and tumor formation was examined. Both cell lines formed five subcutaneous tumors out of a total of five injected sites. The tumor formation of the shSTRN4-1 cells was suppressed compared with the tumor formation of the shCtrl cells (Fig. 5a). The mice were killed 5 weeks after tumor cell injection, and the tumor weight was then determined. The average weight of the shSTRN4-1 cell-derived tumors was significantly reduced compared with that of the shCtrl cells (Fig. 5b). We also examined the effect of STRN4 depletion on the metastasis of KP4 cells. Both shCtrl and shSTRN4-1 cells were injected in the lateral tail vein of mice, and metastasis in the lung and liver was examined. Three out of the five mice injected with shCtrl cells formed metastatic foci in the lung or liver; however, we did not observe any metastatic foci in the lung and liver of the mice injected with shSTRN4-1 (Fig. 5c). We maintained the mice for 8 weeks after tumor injection. Three shCtrl-injected mice died within 8 weeks, but all the mice injected with shSTRN4-1 cells survived for over 8 weeks (Fig. 5d). These results suggest that STRN4 is associated with tumor formation and metastasis.
Affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.