NLRP12 downregulates the Wnt/β-catenin pathway via interaction with STK38 to suppress colorectal cancer
Shahanshah Khan, Youn-Tae Kwak, Lan Peng, Shuiqing Hu, Brandi L. Cantarel, Cheryl M. Lewis, Yunpeng Gao, Ram S. Mani, Thirumala-Devi Kanneganti, Hasan Zaki
Shahanshah Khan, Youn-Tae Kwak, Lan Peng, Shuiqing Hu, Brandi L. Cantarel, Cheryl M. Lewis, Yunpeng Gao, Ram S. Mani, Thirumala-Devi Kanneganti, Hasan Zaki
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Research Article Gastroenterology

NLRP12 downregulates the Wnt/β-catenin pathway via interaction with STK38 to suppress colorectal cancer

Abstract

Colorectal cancer (CRC) at advanced stages is rarely curable, underscoring the importance of exploring the mechanism of CRC progression and invasion. NOD-like receptor family member NLRP12 was shown to suppress colorectal tumorigenesis, but the precise mechanism was unknown. Here, we demonstrate that invasive adenocarcinoma development in Nlrp12-deficient mice is associated with elevated expression of genes involved in proliferation, matrix degradation, and epithelial-mesenchymal transition. Signaling pathway analysis revealed higher activation of the Wnt/β-catenin pathway, but not NF-κB and MAPK pathways, in the Nlrp12-deficient tumors. Using Nlrp12–conditional knockout mice, we revealed that NLRP12 downregulates β-catenin activation in intestinal epithelial cells, thereby suppressing colorectal tumorigenesis. Consistent with this, Nlrp12-deficient intestinal organoids and CRC cells showed increased proliferation, accompanied by higher activation of β-catenin in vitro. With proteomic studies, we identified STK38 as an interacting partner of NLRP12 involved in the inhibition of phosphorylation of GSK3β, leading to the degradation of β-catenin. Consistently, the expression of NLRP12 was significantly reduced, while p-GSK3β and β-catenin were upregulated in mouse and human colorectal tumor tissues. In summary, NLRP12 is a potent negative regulator of the Wnt/β-catenin pathway, and the NLRP12/STK38/GSK3β signaling axis could be a promising therapeutic target for CRC.

Authors

Shahanshah Khan, Youn-Tae Kwak, Lan Peng, Shuiqing Hu, Brandi L. Cantarel, Cheryl M. Lewis, Yunpeng Gao, Ram S. Mani, Thirumala-Devi Kanneganti, Hasan Zaki

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Figure 7

NLRP12 suppresses β-catenin activation via inhibition of GSK3β phosphorylation.

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NLRP12 suppresses β-catenin activation via inhibition of GSK3β phosphory...
(A) GFP- or NLRP12-expressing HEK293T, HCT116, and HT29 cells were stimulated with Wnt3a. Cell lysates were analyzed for NLRP12, β-catenin, p-β-catenin, GSK3β, p-GSK3β, and β-actin by Western blotting. (B) Scramble or NLRP12-KO HEK293T, HCT116, and HT29 cells were stimulated with Wnt3a. At indicated time points, cells lysates were used to measure NLRP12, β-catenin, GSK3β, p-GSK3β, and β-actin by Western blotting. (C) Colon tissues were collected from healthy and tumor-bearing WT and Nlrp12–/– mice and analyzed for GSK3β and p-GSK3β by Western blotting. (D) Colorectal tumors were induced in Vil-Cre, Nlrp12fl/fl, and Nlrp12fl/fl;Vil-Cre mice with AOM plus DSS. Tumors collected 12 weeks after AOM/DSS treatment were analyzed for GSK3β, p-GSK3β, and β-actin. (E and F) Colorectal tumors and adjacent nontumor tissues from WT mice following AOM/DSS-mediated tumor induction were used to measure NLRP12, β-catenin, GSK3β, p-GSK3β, and β-actin by Western blotting. (F) Band intensities of NLRP12, β-catenin, GSK3β, and p-GSK3β as shown in E were measured by densitometry. Data represent mean ± SEM. (G and H) Human colorectal tumors and adjacent nontumor tissues were analyzed for NLRP12, β-catenin, GSK3β, p-GSK3β and α-tubulin by Western blotting. Band intensities of NLRP12, β-catenin, GSK3β, and p-GSK3β were measured by densitometry. Data represent mean ± SEM. *P < 0.05, **P < 0.01 by unpaired, 2-tailed Student’s t test. Experiments represented in A and B were repeated 3 times, and those in C–H were repeated 2 times.