Fig 1: QPCT enhances the stability of PIK3CA by reducing the degradation of PIK3CA ubiquitination. (A) Results of western blot analysis of QPCT and PIK3CA in QPCT-overexpressing 786-O and A498 cells and control cells. (B) Results of western blot analysis of QPCT and PIK3CA in OS-RC-2 and ACHN cells transfected with sh-QPCT or sh-NC. (C) Representative immunohistochemical results of QPCT and PIK3CA in xenografts. Scale bar, 100 µm. (D) Western blot analysis of PIK3CA in QPCT overexpressed 786-O cells and control cells treated with CHX and sunitinib (5 µm) for a different period of time. (E) Western blot analysis of PIK3CA ubiquitination in QPCT overexpressed 786-O and A498 cells and control cells after sunitinib (5 µM) treatment for 48 h. GAPDH was used as the load control. Results are presented as the mean ± SD. *P<0.05. QPCT, glutaminyl peptide cyclotransferase; PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; CHX, cycloheximide.
Fig 2: (A) RT-qPCR of CTCF siRNA interference efficiency in ACHN and OS-RC-2 cells. (B) RT-qPCR of lentivirus-CTCF overexpression efficiency in 786-O and KETR-3 cells. (C) RT-qPCR of lentivirus-QPCT overexpression efficiency in 786-O and A498 cells. (D) RT-qPCR of QPCT shRNA interference efficiency in 786-O cells. (E) RT-qPCR of lentivirus-PIK3CA overexpression efficiency in 786-O and A498 cells. (F) RT-qPCR of PIK3CA shRNA interference efficiency in 786-O and A498 cells. CTCF, CCCTC-binding factor; QPCT, glutaminyl peptide cyclotransferase. Results are presented as the mean ± SD. **P<0.01.
Fig 3: Overexpression of PIK3CA promotes sunitinib resistance in RCC. (A) Subcutaneous xenograft growth in nude mice under different treatment conditions (upper panel). Anatomical picture of subcutaneous xenografts in nude mice (lower left panel) and growth curve of subcutaneous xenografts (lower right panel). (B) Representative immunohistochemical results of PIK3CA, CD31 and CD34 in xenografts. Scale bar, 100 µm. Results are presented as the mean ± SD. *P<0.05. PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; RCC, renal cell carcinoma.
Fig 4: PIK3CA plays a role in angiogenesis in RCC. (A) Representative results of HUVEC tube formation cultured with the supernatant of PIK3CA-knockdown RCC cells. (B) Representative results of HUVEC tube formation cultured with the supernatant of PIK3CA-overexpressing RCC cells. The group with VEGF added to the culture medium was used as the positive control. Total tube length was calculated by ImageJ software. Results are presented as the means ± SD. **P<0.01. PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; RCC, renal cell carcinoma; CM, conditioned medium.
Fig 5: QPCT regulates angiogenesis through PIK3CA. (A) Representative results of HUVEC tube formation cultured with the supernatant of QPCT-overexpressing+PIK3CA-knockdown RCC cells. (B) Representative results of HUVEC tube formation cultured with the supernatant of QPCT-knockdown +PIK3CA-overexpressing RCC cells. (C) Representative results of western blot analysis of AKT and p-AKT in PIK3CA overexpressed 786-O and A498 cells and control cells. The group with VEGF added into the culture medium was used as the positive control. Total tube length was calculated using ImageJ software. Results are presented as the means ± SD. *P<0.05. QPCT, glutaminyl peptide cyclotransferase; PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; CM, conditioned medium.
Supplier Page from Abcam for Anti-PI 3 Kinase catalytic subunit alpha/PIK3CA antibody [SP139]