CPVL promotes glioma progression via STAT1 pathway inhibition through interactions with the BTK/p300 axis
Hui Yang, … , Xiuming Liang, Kun Lv
Hui Yang, … , Xiuming Liang, Kun Lv
Published November 16, 2021
Citation Information: JCI Insight. 2021;6(24):e146362. https://doi.org/10.1172/jci.insight.146362.
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Research Article Oncology

CPVL promotes glioma progression via STAT1 pathway inhibition through interactions with the BTK/p300 axis

Abstract

CPVL (carboxypeptidase, vitellogenic-like) is a serine carboxypeptidase that was first characterized in human macrophages. However, the function of CPVL remains unclear in a variety of tumors. The quantitative PCR (qPCR), Western blotting, and IHC assays were utilized to measure the CPVL expression. CPVL was significantly upregulated in glioma cells and tissues compared with normal cells and tissues, respectively. Moreover, high CPVL expression was correlated with advanced clinical grade and poor prognosis. Silencing of CPVL promoted glioma cell apoptosis, and it inhibited cell proliferation and tumorigenicity in vitro and in vivo. Ingenuity Pathway Analysis (IPA) demonstrated that CPVL silencing activated the IFN-γ/STAT1 signaling pathway, thereby inducing glioma cell apoptosis. Mechanistically, immunopurification, mass spectrometry, IP, and glutathione S-transferase (GST) pull-down experiments elucidated that CPVL physically interacts with Bruton’s tyrosine kinase (BTK) and downregulates the STAT1 phosphorylation through promoting p300-mediated STAT1 acetylation. Our findings reveal the crucial role of CPVL in promoting the progression of glioma through suppressing STAT1 phosphorylation. CPVL might serve as a potential prognostic biomarker and therapeutic target for the treatment of glioma.

Authors

Hui Yang, Xiaocen Liu, Xiaolong Zhu, Xueqin Li, Lan Jiang, Min Zhong, Mengying Zhang, Tianbing Chen, Mingzhe Ma, Xiuming Liang, Kun Lv

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Figure 5

CPVL induces apoptosis of glioma cells via STAT1 signaling pathway.

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CPVL induces apoptosis of glioma cells via STAT1 signaling pathway. (A) ...
(A) Relative IFN-γ/STAT1 signaling pathway downstream response gene mRNA expression in CPVL-silenced U251 cells determined by real-time PCR (n = 3). (B) Western blotting analysis of the IFN-γ/STAT1 signaling pathway downstream response genes’ protein expression in CPVL-silenced U251 cells. (C and D) Relative IFN-γ/STAT1 signaling pathway downstream response gene mRNA expression in matched primary glioma tissues (T, n = 60) and adjacent noncancerous tissues (ANT, n = 60). (E and F) The expression level of relative the IFN-γ/STAT1 signaling pathway downstream response genes in glioma specimens of low clinical grades and high clinical grades. (G) IHC staining analysis of the expression of p-STAT1 in matched primary cancer tissues (T) and adjacent noncancerous tissues (ANT). Representative IHC images (left) and IHC score quantification (right) for CPVL in tissue sections are shown. Scale bars: 100 μm (200× magnification). (H) IHC staining analysis of the expression of p-STAT1 in normal brain tissues and glioma tissues of different clinical grades. Representative IHC images (left) and IHC score quantification (right) for CPVL in tissue sections are shown. Scale bars: 100 μm (200× magnification, upper panels) and 50 μm (400× magnification, lower panels). The clinical grades of patients were characterized (patient 1, grade II; patient 2, grade III; patient 3, grade I; patient 4, grade III; patient 5, grade IV). All experiments were repeated 3 times. β-Actin was used as a loading control. Bar graph data are presented as mean ± SD. One-way ANOVA with Dunnett’s multiple comparisons test (H), and 2-tailed Student’s t test (A, C, E, and G) analyses were performed. *P < 0.05.