Skip to main content
. 2021 Jun 11;12(16):4819–4829. doi: 10.7150/jca.58670

Figure 4.

Figure 4

STAT3 regulates V-ATPase expression in tumor cells to promote anoikis resistance. (A) Immunoblot analysis for STAT3 and p-STAT3 expression in HELA and B16F10 cells cultured for 6 hours either in adherent and suspension condition (B) Phase-contrast microscopic images of HELA, MCF-7, and B16F10 cells cultured in suspension and treated with or without 5 µM stattic for 24 hours (C) Protein expression of STAT3, p-STAT3, ATP6V0D1, ATP6V1B2 from the total lysate of HELA, MCF-7 and B16F10 cultured in suspension in the presence or absence of 5 µM stattic for 6 hours; (D) Percentage apoptosis of HELA, MCF-7 and B16F10 cells treated with or without STAT3 inhibitor-stattic (5 µM) for 24 hours; (E) Mean fluorescence intensity of indicated cells treated with or without stattic for 24 hours and labeled with CM-H2DCFDA as determined by flow cytometer. (F) K48 polyUb-modified proteins in matrix-detached HELA, MCF-7, and B16F10 cells treated with or without stattic for 24 hours; SS and NS fractions are shown. NS - NP-40 soluble fraction, SS - SDS soluble fraction; (G) Immunoblot analysis for STAT3 expression in HELA and MCF-7 cells transfected with pCMV-FLAG-STAT3 cultured in suspension for 6 hours. (H) Relative mRNA levels of some V-ATPase genes in HELA and MCF-7 expressing pCMV-STAT3 cultured for 6 hours. (I) Percentage apoptotic HELA and MCF-7 expressing pCMV-STAT3 cells treated with or without 10 nM bafilomycin A for 24 hours as determined by flow cytometry. (J) Mean fluorescence intensity of HELA and MCF-7 expressing pCMV-STAT3 with or without bafilomycin A treatment for 24 hours, stained with CM-H2DCFDA for 30 minutes, and evaluated by flow cytometry. Data are expressed as means ± SEM. Representative data from three independent experiments (H-J). One way ANOVA: p*<0.05, **p < 0.01, ***p < 0.001, ****p< 0.0001, ns, no significant difference.