Figure 2.

EIF3J-DT was highly expressed in the drug-resistant gastric tumor cells and EIF3J-DT silencing inhibited tumor growth. (A) Heatmap of differential expressed lncRNAs (fold change > 2) in the MGC803, MGC803/OXA, and MGC803/5Fu cells. (B) mRNA expression levels of PAX8-AS1, EIF3J-DT, AKT3-IT1, MALAT1, and TXNP6 with OXA (10 μg/mL) (upper) or 5-Fu (20 μg/mL) (lower) treatment over time detected by qPCR. (C) mRNA expression levels of EIF3J-DT (upper) and MALAT1 (lower) between the MGC803 and MGC803/OXA cells, or between the MGC803 and MGC803/5Fu cells detected by qPCR. (D) MTT assay comparing the cell viability between the NC and si-EIF3J-DT MGC803 cells 24 h after being treated with OXA (left) and 5-Fu (right). (E) MTT assay comparing the cell viability between the NC and si-EIF3J-DT MGC803/OXA cells or MGC803/5Fu cells 24 h after being treated with OXA (left) or 5-Fu (right). (F) Numbers of colony formation of the LV-NC and LV-Sh transfected MGC803 (left) and MKN45 (right) cells 14 d after being treated with PBS, OXA (10 μg/mL), and 5-Fu (20 μg/mL). LV-NC indicated the MGC803 and MKN45 cells with stable mock-vehicle transfection. LV-Sh indicated the MGC803 and MKN45 cells with sh-EIF3J-DT transfection. (G) Apoptosis rates of the LV-NC and LV-Sh MGC803 (left) and MKN45 (right) cells 24 h after being treated with PBS, OXA (10 μg/mL), and 5-Fu (20 μg/mL). (H) Western blotting performed on the NC, NC+OXA (20 and 40 μg/mL), Si, and Si+OXA (20 and 40 μg/mL) MGC803 cells (left), or the NC, NC+5-Fu (100 and 200 μg/mL), Si, and Si+5-Fu (100 and 200 μg/mL) MGC803 cells (right) with 24-h treatment against C-PARP, PARP, C-CASP3, and CASP3. Si indicated si-EIF3J-DT transfection. (I) Changes in tumor volumes (left) and tumor weight (right) of mice from the six groups (including NC, Sh, NC+OXA, Sh+OXA, NC+5-Fu, and Sh+5-Fu). Sh indicated sh-EIF3J-DT transfection. For OXA treatment, 0.1 mg/kg, intraperitoneal injection, three times per week; for 5-Fu treatment, 0.5 mg/kg, intraperitoneal injection, three times per week. (J) Representative images from the in vivo living imaging showing the subcutaneous tumors in the six groups (left) on day 28. The graph on the right calculated the total flux of tumors from different groups. Data were quantified as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, vs the relative control