Basic Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Apr 15, 2024; 16(4): 1532-1546
Published online Apr 15, 2024. doi: 10.4251/wjgo.v16.i4.1532
Two missense STK11 gene variations impaired LKB1/adenosine monophosphate-activated protein kinase signaling in Peutz-Jeghers syndrome
Jin Liu, Si-Cong Zeng, An Wang, Hai-Ying Cheng, Qian-Jun Zhang, Guang-Xiu Lu
Jin Liu, Si-Cong Zeng, An Wang, Hai-Ying Cheng, Qian-Jun Zhang, Guang-Xiu Lu, Hunan Guangxiu Hospital, Hunan Normal University, Changsha 410000, Hunan Province, China
Jin Liu, Si-Cong Zeng, Scientific Research Department, Reproductive and Genetic Hospital of Citic-Xiangya, Changsha 410000, Hunan Province, China
Author contributions: Liu J contributed to drafting of the manuscript; Wang A and Cheng HY contributed to clinical polyp treatment; Zeng SC and Zhang QJ contributed to experiments and analysis; Lu GX contributed to critical revision of the manuscript for important intellectual content; all authors read and approved the final manuscript.
Supported by the Natural Science Foundation of Hunan Province, China, No. 2023JJ30422.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of the Reproduction and Genetics Hospital of CITIC-Xiangya [Approval No. LL-SC-2016(008)].
Conflict-of-interest statement: All authors declared no conflicts of interest to disclose.
Data sharing statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Guang-Xiu Lu, PhD, Doctor, Professor, Hunan Guangxiu Hospital, Hunan Normal University, No. 8 Luyun Road, Yuelu District, Changsha 410000, Hunan Province, China. lugxdirector@aliyun.com
Received: December 5, 2023
Peer-review started: December 5, 2023
First decision: December 14, 2023
Revised: December 29, 2023
Accepted: February 3, 2024
Article in press: February 3, 2024
Published online: April 15, 2024
Processing time: 127 Days and 10.4 Hours
Abstract
BACKGROUND

Peutz-Jeghers syndrome (PJS) is a rare hereditary neoplastic disorder mainly associated with serine/threonine kinase 11 (STK11/LKB1) gene mutations. Preimplantation genetic testing can protect a patient’s offspring from mutated genes; however, some variations in this gene have been interpreted as variants of uncertain significance (VUS), which complicate reproductive decision-making in genetic counseling.

AIM

To identify the pathogenicity of two missense variants and provide clinical guidance.

METHODS

Whole exome gene sequencing and Sanger sequencing were performed on the peripheral blood of patients with PJS treated at the Reproductive and Genetic Hospital of Citic-Xiangya. Software was employed to predict the protein structure, conservation, and pathogenicity of the two missense variation sites in patients with PJS. Additionally, plasmids were constructed and transfected into HeLa cells to observe cell growth. The differences in signal pathway expression between the variant group and the wild-type group were compared using western blot and immunohistochemistry. Statistical analysis was performed using one-way analysis of variance. P < 0.05 was considered statistically significant.

RESULTS

We identified two missense STK11 gene VUS [c.889A>G (p.Arg297Gly) and c.733C>T (p.Leu245Phe)] in 9 unrelated PJS families who were seeking reproductive assistance. The two missense VUS were located in the catalytic domain of serine/threonine kinase, which is a key structure of the liver kinase B1 (LKB1) protein. In vitro experiments showed that the phosphorylation levels of adenosine monophosphate-activated protein kinase (AMPK) at Thr172 and LKB1 at Ser428 were significantly higher in transfected variation-type cells than in wild-type cells. In addition, the two missense STK11 variants promoted the proliferation of HeLa cells. Subsequent immunohistochemical analysis showed that phosphorylated-AMPK (Thr172) expression was significantly lower in gastric, colonic, and uterine polyps from PJS patients with missense variations than in non-PJS patients. Our findings indicate that these two missense STK11 variants are likely pathogenic and inactivate the STK11 gene, causing it to lose its function of regulating downstream phosphorylated-AMPK (Thr172), which may lead to the development of PJS. The identification of the pathogenic mutations in these two clinically characterized PJS patients has been helpful in guiding them toward the most appropriate mode of pregnancy assistance.

CONCLUSION

These two missense variants can be interpreted as likely pathogenic variants that mediated the onset of PJS in the two patients. These findings not only offer insights for clinical decision-making, but also serve as a foundation for further research and reanalysis of missense VUS in rare diseases.

Keywords: Missense; STK11; Peutz-Jeghers syndrome; Rare disease; Genetic counseling; Assisted reproductive technique

Core Tip: These two missense variants, STK11 c.889A>G (p.Arg297Gly) and STK11 c.733C>T (p.Leu245Phe), have been found to contribute to the development of Peutz-Jeghers syndrome (PJS) by impairing the STK11/adenosine monophosphate-activated protein kinase signaling pathway. It clarifies that these two germline variants, STK11 c.889A>G (p.Arg297Gly) and STK11 c.733C>T (p.Leu245Phe), are likely pathogenic mutations, providing valuable information for fertility selection in patients with PJS.