Gene expression barcode values reveal a potential link between Parkinson's disease and gastric cancer

Causal relationship between Parkinson's disease and gastric cancer: a Mendelian randomization study

BACKGROUND

Age-related diseases, including Parkinson's disease and gastric cancer, substantially affect the global aging population. Previous observational research has suggested a potential association between Parkinson's disease and gastric cancer; however, findings regarding this aspect have been inconsistent. In the present study, we used data from genome-wide association studies to infer a causal relationship between Parkinson's disease and gastric cancer based on genetic variations.

METHODS

We used the two-sample Mendelian randomization method to analyze data from the genome-wide association study catalog, including 482,730 and 476,116 patients with Parkinson's disease and gastric cancer, respectively. Inverse-variance weighting was used as the primary Mendelian randomization analysis. We conducted sensitivity analyses to evaluate heterogeneity and pleiotropy, followed by two-step Mendelian randomization to ascertain the latent mediator of the relationship between Parkinson's disease and gastric cancer.

RESULTS

Our results suggested a causal negative relationship between Parkinson's disease and gastric cancer. Heterogeneity and pleiotropy analyses confirmed the robustness of the inverse-variance weighting results. Furthermore, P2X6 was identified as a key factor mediating this negative causal relationship.

CONCLUSIONS

Patients with Parkinson's disease may have a lower risk of developing gastric cancer, with P2X6 serving as a significant mediating variable. These novel insights can aid the development of potential therapeutic targets for patients with Parkinson's disease or gastric cancer.

Causal association between Parkinson's disease and cancer: a bidirectional Mendelian randomization study

Background

Previous observational research has indicated a correlation between Parkinson's disease (PD) and multiple cancers; but the causality remains unclear. Thus, we utilized Mendelian randomization (MR) analysis to explore the potential causal link between PD and various cancers.

Methods

We conducted a bidirectional two-sample Mendelian randomization (TSMR) of genetic variants associated with PD and 14 types of cancers. Summary statistics on PD and 14 types of cancers were obtained from the International Parkinson's Disease Genomics Consortium and the study by Sakaue et al. The primary method employed was inverse variance weighted (IVW), complemented by multiple sensitivity analyses to evaluate heterogeneity and pleiotropy. The false discovery rate (FDR) was employed to control the false positive rate of multiple hypothesis testing.

Results

Following rigorous sensitivity analyses and corrections, our findings revealed suggestive associations between PD and certain cancers. We observed that PD decreases the risk of gastric cancer and colorectal cancer (OR = 0.936, 95% CI = 0.881-0.995, p = 0.034, P FDR = 0.239; OR = 0.955, 95% CI = 0.912-0.999, p = 0.046, P FDR = 0.215), while increasing the risk of breast cancer (OR = 1.043, 95% CI = 1.004-1.084, p = 0.029, P FDR = 0.402). Notably, we found no evidence supporting a reverse causal relationship. Additionally, in the reverse pathway, skin cancer demonstrated a suggestive causal relationship with PD (OR = 0.913, 95% CI = 0.857-0.973, p = 0.005, P FDR = 0.066).

Conclusion

Our MR analysis provides evidence supporting unidirectional suggestive causal relationships between PD and certain cancers. These findings enrich our comprehension of the intricate interplay between PD and cancer, warranting further investigation into the underlying biological mechanisms.

Association between Parkinson's Disease and Cancer: New Findings and Possible Mediators

Epidemiological evidence points to an inverse association between Parkinson's disease (PD) and almost all cancers except melanoma, for which this association is positive. The results of multiple studies have demonstrated that patients with PD are at reduced risk for the majority of neoplasms. Several potential biological explanations exist for the inverse relationship between cancer and PD. Recent results identified several PD-associated proteins and factors mediating cancer development and cancer-associated factors affecting PD. Accumulating data point to the role of genetic traits, members of the synuclein family, neurotrophic factors, the ubiquitin-proteasome system, circulating melatonin, and transcription factors as mediators. Here, we present recent data about shared pathogenetic factors and mediators that might be involved in the association between these two diseases. We discuss how these factors, individually or in combination, may be involved in pathology, serve as links between PD and cancer, and affect the prevalence of these disorders. Identification of these factors and investigation of their mechanisms of action would lead to the discovery of new targets for the treatment of both diseases.

The relationship between Parkinson's disease and gastrointestinal diseases

An increasing number of studies have provided evidence for the hypothesis that the pathogenesis of Parkinson's disease (PD) may derive from the gut. Firstly, Lewy pathology can be induced in the enteric nervous system (ENS) and be transported to the central nervous system (CNS) via the vagal nerve. Secondly, the altered composition of gut microbiota causes an imbalance between beneficial and deleterious microbial metabolites which interacts with the increased gut permeability and the gut inflammation as well as the systemic inflammation. The activated inflammatory status then affects the CNS and promotes the pathology of PD. Given the above-mentioned findings, researchers start to pay attention to the connection between PD and gastrointestinal diseases including irritable bowel syndrome, inflammatory bowel disease (IBD), microscopic colitis (MC), gastrointestinal infections, gastrointestinal neoplasms, and colonic diverticular disease (CDD). This review focuses on the association between PD and gastrointestinal diseases as well as the pathogenesis of PD from the gut.