(R)-2-OHPA increases sensitivity of gastric cancer cell lines to cisplatin.
a, b) SGC7901 cells were untreated (CTL) or treated with BSA, 50 μM PA, (R)-2-OHPA (2R), or (S)-2-OHPA (2S) for 24 h. (a) The whole cell lysates were prepared and subjected to Western blot analysis with antibodies directed against each specific protein as indicated in MKN45 and SGC7901cells. (b) The bands were quantified and presented as the mean ± SEM (n = 3).
c) MTT assay of MKN45 and SGC7901 cells treated with BSA, 50 μM PA, (R)-2-OHPA, or (S)-2-OHPA after incubation for 24 h, 48 h and 72 h, presented as mean ± SEM (n = 3). Statistical significance for MKN45 cell: BSA versus all other treatments showed P < 0·05 at least from 24 h onwards; 2R versus PA showed P < 0·05 at least from 24 h onwards; 2S versus PA showed no statistical difference from 24 h onwards. Statistical significance for SGC7901 cell: BSA versus all other treatments showed P < 0·05 at least from 48 h onwards; 2R versus PA showed P < 0·05 at least from 24 h onwards; 2S versus PA showed P < 0·05 at least from 48 h or 72 h, respectively.
d, e) Migration assay of SGC7901 cells treated with BSA, 50 μM PA, (R)-2-OHPA, or (S)-2-OHPA for 24 h. (d) Representative photographs are presented (Scale bar, 100 μm) and (e) the relative number of migratory cells were counted and presented as mean ± SEM (n = 5). DMEM and growing media were used as negative and positive controls, respectively.
f) MTT assay of MKN45 and SGC7901 cells pre-treated with 50 μM PA, (R)-2-OHPA (2R), or (S)-2-OHPA (2S) in response to cisplatin, presented as mean ± SEM (n = 3). Statistical significance for MKN45 cell: PA treatment or 2S treatment versus control showed no statistical difference from 1 μM onwards; 2R versus control showed P < 0·05 at least from 5 μM or 10 μM, respectively. Statistical significance for SGC7901 cell: PA treatment versus control showed P < 0·05 at least from 5 μM or 10 μM, respectively; 2R treatment versus control showed P < 0·05 at least from 1 μM to 10 μM; 2S treatment versus control showed no statistical difference from 1 μM onwards.
g) MTT assay of MKN45 and SGC7901 cells untreated (CTL) or pre-treated with 10 μm Gant61 (G), 1 μm Rapamycin (Rap), 50 μM (R)-2-OHPA (2R) in response to cisplatin, presented as mean ± SEM (n = 3). Statistical significance for MKN45 cell: G treatment versus control showed P < 0·05 at least from 5 μM; Rap treatment versus control showed P < 0·05 at least from 5 μM; 2R treatment versus control showed P < 0·05 at least from 5 μM onwards. Statistical significance for SGC7901 cell: G treatment versus control showed P < 0·05 at least from 5 μM or 10 μM, respectively; Rap treatment versus control showed P < 0·05 at least from 5 μM onwards; 2R treatment versus control showed P < 0·05 at least from 1 μM onwards.
h) MTT assay of MKN45 and SGC7901 cells pre-treated with 50 μM (R)-2-OHPA (2R), 50 μM (R)-2-OHPA in combination with 10 μM Gant61 (G + 2R) or 1 μM Rapamycin (Rap+2R) in response to cisplatin, presented as mean ± SEM (n = 3). Statistical significance for both MKN45 and SGC7901 cells: G + 2R treatment or Rap+2R treatment versus 2R treatment showed no statistical difference from 1 μM onwards.
*, P < 0·05; **, P < 0·01; ***, P < 0·001.