High MEAK7 Expression Associated with Shorter Disease-Free Survival in Triple-Negative Breast Cancer: Public Data Analysis
Elevated MEAK7 expression in triple-negative breast cancer
An integrated analysis of public breast cancer datasets found that MEAK7 gene expression was higher in triple-negative breast cancer (TNBC), and that higher expression was associated with shorter disease-free survival. However, no statistically significant association was found with overall survival or distant metastasis-free survival in patients with TNBC. Published in Biology, this bioinformatics study proposes MEAK7 as a candidate prognostic marker and a candidate for follow-up functional studies.
TNBC is breast cancer that is negative for estrogen receptors, progesterone receptors, and HER2. The researchers focused on MEAK7, known as an alternative regulator of mTORC1 signaling, which is involved in cell growth and metabolism. Using RNA sequencing data from TCGA and GTEx and microarray data from bc-GenExMiner, among other sources, they compared expression between normal tissue and tumors and across breast cancer subtypes, and examined survival measures.
In the UALCAN analysis, median MEAK7 expression was 12.3 TPM in TNBC, higher than in adjacent normal tissue (7.8 TPM), luminal subtypes (5.9 TPM), and the HER2-positive subtype (9.7 TPM). TPM is a normalized unit for comparing RNA expression levels. The microarray analysis also showed high expression in TNBC and the basal-like subtype. However, the researchers assessed the expression difference between TNBC and non-TNBC as having a moderate effect size.
Results differed for disease-free and overall survival
Among patients with TNBC, the group with MEAK7 expression above the median had shorter disease-free survival (DFS) than the group at or below the median. The hazard ratio was 1.27, with a 95% confidence interval of 1.03–1.57. This indicates a higher relative hazard of an event in the DFS analysis; it does not mean that survival time was reduced by 27%. By contrast, differences in overall survival (OS) and distant metastasis-free survival (DMFS) were not significant. In basal-like breast cancer, an association with DFS was also observed, while no significant differences were found for OS or DMFS.
The association between MEAK7 expression and overall survival remained in an analysis adjusted for age and tumor stage. However, this result was based on 1,057 patients with breast cancer in TCGA-BRCA, rather than patients with TNBC alone. The hazard ratio was 1.21, with a 95% confidence interval of 1.02–1.45. This cannot be taken to establish independent prognostic value in TNBC. The adjustment variables did not include tumor grade, lymph node status, or treatment type.
Clues from hypomethylation and RNA correlations
In TNBC, methylation levels in the MEAK7 promoter, a region that regulates its expression, were lower than in adjacent normal tissue and luminal subtypes. The researchers interpreted this as a potential regulatory mechanism that could explain higher expression. However, they did not establish that hypomethylation directly caused increased expression.
In the breast cancer cohort, MEAK7 expression showed negative correlations with miR-149-3p, miR-135a-5p, and LINC00993 expression, and positive correlations with miR-135b-5p and HIF1A-AS2 expression. These are patterns of co-variation in expression, not evidence that the molecules directly inhibit or activate one another. In HPA breast cancer immunohistochemistry data, MEAK7 protein staining was low or moderate. Further investigation is needed to determine whether increased RNA expression is consistently reflected at the protein level.
From CRISPR design to functional validation
The researchers computationally designed 20 CRISPR guide RNAs targeting MEAK7. Some candidates had high predicted scores and no off-target sites were identified within the scope of the analysis, while other candidates had potential off-target sites. These results do not establish actual cutting efficiency, safety, or an anticancer effect of MEAK7 inhibition.
Several analysis platforms share some TCGA patient data, so repeated results cannot all be considered independent validation. Another limitation is the absence of formal multiple-testing correction across the many survival measures and subgroup analyses. The provided text does not specify the follow-up period for the TNBC survival analysis. The researchers described these results as hypothesis-generating observations and stated that functional experiments and prospective validation are needed. The methods and results are available in the full paper.
Triple-negative breast cancer (TNBC) represents a clinically challenging breast cancer (BC) subtype, characterized by aggressive behavior, high recurrence risk, and limited therapeutic options. MEAK7 has been identified as an alternative mTORC1 signaling pathway regulator; however, its role in BC and TNBC remains uninvestigated. This study aims to assess MEAK7 expression, prognostic significance, and therapeutic potential. We employed public datasets, including TCGA, bc-GenExMiner v5.2, GEPIA3, DOSurvive platforms, Kaplan-Meier Plotter, UALCAN, TIMER2.0, STRING, ENCORI, HPA, miRDB, TargetScan, and CRISPRdb. MEAK7 expression was significantly elevated in BC tissues versus normal breast tissue. MEAK7 expression was pronounced in TNBC and basal-like subtypes, with hypomethylation of its promoter region in TNBC. Elevated MEAK7 expression correlated with reduced disease-free survival (DFS) in TNBC and basal-like. Multivariate Cox regression identified MEAK7 as a significant prognostic factor for overall survival, independent of age and tumor stage. MEAK7 showed CRISPR-targetable gRNA profiles with high on-target efficiency and minimal off-target effects. Analyses revealed negative correlation with tumor-suppressive RNAs (miR-149-3p, miR-135a-5p, and LINC00993) and positive correlation with aggressive regulators (miR-135b-5p and HIF1A-AS2). This study represents one of the initial comprehensive and multi-platform bioinformatic analyses demonstrating that MEAK7 exhibits elevated expression in breast cancer, particularly within the aggressive TNBC. The findings indicate that MEAK7 may serve as a promising prognostic biomarker in TNBC biology and suggest its viability as a molecular candidate for future investigation in targeted therapeutic strategies.
The practical value of this study is that it proposes MEAK7 as a candidate for exploring the biology related to recurrence in TNBC. By analyzing expression, methylation, survival, and RNA correlations together and preparing CRISPR guide candidates, the researchers provided concrete directions for follow-up experiments. Researchers can test whether inhibiting MEAK7 actually changes tumor cell growth and mTOR signaling, and whether adding MEAK7 information to existing clinical variables improves prognostic accuracy. The current results do not provide sufficient grounds for more accurate prognostic predictions or treatment selection for patients. Validation in independent cohorts and clarification of the differences between RNA and protein findings are needed to assess its potential for clinical use.