The experimental groups were treated with different concentration of trastuzumab, and cell apoptosis rate was analyzed by 7-AAD/APC double staining flow cytometry, and cell growth inhibition rate was tested by cell counting kit 8 (CCK-8).  Moreover, overexpression of RNPC1 decreased and knockdown of RNPC1 increased the levels of p-PI3K and p-AKT while the total protein expressions of both were marginally changed.The results of analysis using a cell counting CCK-8 kit showed that the RNPC1 overexpressed group had a higher growth inhibition rate [(20.33±1.25)%, (35.38±2.05)%, (50.43±2.12)%, (65.35±2.08)% and(76.00±2.16)%, respectively] than that of the control group [(13.67±1.24)%, (27.86±2.05)%, (39.72±1.69)%, (53.33±1.70)% and(62.68±2.07)% ] when treated with different concentrations of trastuzumab (5, 10, 15, 20 and 25 μg/ml). 
CCK-8
The expressions of RNPC1 and HER-2 mRNA were detected by qRT-PCR, and the expressions of RNPC1, HER-2 and PI3K/AKT proteins were detected by Western blot after transfected with RNPC1 lentiviral vector, respectively.  The results of qRT-PCR showed that overexpression of RNPC1 increased the expressions of RNPC1 and HER-2 mRNA, and the expressions of RNPC1 and HER-2 were decreased after RNPC1 knockdown. 
qRT-PCR
The expressions of RNPC1 and HER-2 mRNA were detected by qRT-PCR, and the expressions of RNPC1, HER-2 and PI3K/AKT proteins were detected by Western blot after transfected with RNPC1 lentiviral vector, respectively.  The expression of apoptosis-related proteins was detected by Western blot assay.



Western blot