Correlation between LRRK2 gene G2385R polymorphisms and Parkinson’s disease

Prevalence of ten LRRK2 variants in Parkinson's disease: A comprehensive review

INTRODUCTION

Variants in the leucine-rich repeat kinase 2 gene (LRRK2) are risk factors for Parkinson's disease (PD), but their prevalence varies geographically, reflecting the locations of founder events and dispersion of founders' descendants.

METHODS

A comprehensive literature review was conducted to identify studies providing prevalence estimates for any of ten variants in LRRK2 (G2019S, R1441C, R1441G, R1441H, I2020T, N1437H, Y1699C, S1761R, G2385R, R1628P) among individuals with PD globally. We calculated crude country-specific variant prevalence estimates and, when possible, adjusted estimates for ethno-racial composition. For clinic-based studies, probands were used over other familial cases, whereas for population-based studies, all PD cases were used.

RESULTS

The analysis included 161 articles from 52 countries yielding 581 prevalence estimates across the ten variants. G2019S was the most common variant, exceeding 1.0% in 26 of 51 countries with estimates. The other variants were far less common. G2385R and R1628P were observed almost exclusively in East Asian countries, where they were found in ∼5-10% of cases. All prevalence estimates adjusted for ethno-racial composition were lower than their unadjusted counterparts, although data permitting this adjustment was only available for six countries.

CONCLUSIONS

Except for G2019S, the LRRK2 variants covered in this review were uncommon in most countries studied. However, there were countries with higher prevalence for some variants, reflecting the uneven geographic distribution of LRRK2 variants. The fact that ethno-racial group‒adjusted estimates were lower than crude estimates suggests that estimates derived largely from clinic-based studies may overstate the true prevalence of some LRRK2 variants in PD.

Value of Serum miRNA-96-5p and miRNA-99a-5p as Diagnostic Biomarkers for Hepatocellular Carcinoma

Purpose

Circulatory microRNAs (miRNAs) have the potential to be employed as markers for cancer detection and as prognostic tools for disease management. As a result, our goal was to explore the effectiveness of serum miRNA-96-5p and miRNA-99a-5p as diagnostic tools in hepatocellular carcinoma (HCC).

Patients and methods

Blood samples were collected from 55 patients with HCV-induced HCC, 55 patients with HCV-induced liver cirrhosis, and 55 healthy controls. The expression levels of miRNA-96-5p and miRNA-99a-5p were measured using quantitative RT-PCR.

Results

miRNA-96-5p expression levels were increased in HCC patient sera, while miRNA-99a-5p levels were reduced. According to ROC curve analysis, using a combination of circulating miRNA-96-5p, miRNA-99a-5-, and alpha-fetoprotein (AFP) improves the accuracy of diagnoses for HCC, with an area under the curve (AUC) of 0.97, compared to AUCs of 0.82, 0.86, and 0.73, respectively, for the individual biomarkers. Furthermore, the present data suggested that higher serum miRNA-96-5p levels were linked to larger tumors and metastasis, whereas lower serum miRNA-99a-5p levels were exclusively linked to HCC metastasis.

Conclusion

Using miRNA-96-5p and miRNA-99a-5p in combination with AFP increased both sensitivity and specificity for the diagnosis of HCC. Furthermore, serum levels were linked to tumor size and metastasis. These findings suggested that serum miRNA-96-5p and miRNA-99a-5p could be used as non-invasive biomarkers for the diagnosis of HCC.

A Comprehensive Analysis of Population Differences in LRRK2 Variant Distribution in Parkinson's Disease

Background:LRRK2 variants have been demonstrated to have distinct distributions in different populations. However, researchers have thus far chosen to focus on relatively few variants, such as R1628P, G2019S, and G2385R. We therefore investigated the relationship between common LRRK2 variants and PD risk in various populations.

Methods: Using a set of strict inclusion criteria, six databases were searched, resulting in the selection of 94 articles covering 49,299 cases and 47,319 controls for final pooled analysis and frequency analysis. Subgroup analysis were done for Africans, European/West Asians, Hispanics, East Asians, and mixed populations. Statistical analysis was carried out using the Mantel-Haenszel approach to determine the relationship between common LRRK2 variants and PD risk, with the significance level set at p < 0.05.

Results: In the absence of obvious heterogeneities and publication biases among the included studies, we concluded that A419V, R1441C/G/H, R1628P, G2019S, and G2385R were associated with increased PD risk (p: 0.001, 0.0004, < 0.00001, < 0.00001, and < 0.00001, respectively), while R1398H was associated with decreased risk (p: < 0.00001). In East Asian populations, A419V, R1628P, and G2385R increased risk (p: 0.001, < 0.00001, < 0.00001), while R1398H had the opposite effect (p: 0.0005). G2019S increased PD risk in both European/West Asian and mixed populations (p: < 0.00001, < 0.00001), while R1441C/G/H increased risk in European/West Asian populations only (p: 0.0004).

Conclusions: We demonstrated that LRRK2 variant distribution is different among various populations, which should inform decisions regarding the development of future genetic screening strategies.

Clinical Heterogeneity Among LRRK2 Variants in Parkinson's Disease: A Meta-Analysis

Background: Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Variants in the LRRK2 gene have been shown to be associated with PD. However, the clinical characteristics of LRRK2-related PD are heterogeneous. In our study, we performed a comprehensive pooled analysis of the association between specific LRRK2 variants and clinical features of PD.

Methods: Articles from the Medline, Embase, and Cochrane databases were included in the meta-analysis. Strict inclusion criteria were applied, and detailed information was extracted from the final original articles included. Revman 5.3 software was used for publication biases and pooled and sensitivity analyses.

Results: In all, 66 studies having the clinical manifestations of PD patients with G2019S, G2385R, R1628P, and R1441G were included for the final analysis. The prominent clinical features of LRRK2-G2019S-related PD patients were female sex, higher rates of early-onset PD (EOPD), and family history (OR: 0.77 [male], 1.37, 2.62; p < 0.00001, 0.02, < 0.00001). PD patients with G2019S were more likely to have high scores of Schwab & England (MD: 1.49; p < 0.00001), low GDS scores, high UPSIT scores (MD: 0.43, 4.70; p = 0.01, < 0.00001), and good response to L-dopa (OR: 2.33; p < 0.0001). Further, G2019S carriers had higher LEDD (MD: 115.20; p < 0.00001) and were more likely to develop motor complications, such as dyskinesia and motor fluctuations (OR: 2.18, 2.02; p < 0.00001, 0.04) than non-carriers. G2385R carriers were more likely to have family history (OR: 2.10; p = 0.007) than non-G2385R carriers and lower H-Y and higher MMSE scores (MD: −0.13, 1.02; p = 0.02, 0.0007). G2385R carriers had higher LEDD and tended to develop motor complications, such as motor fluctuations (MD: 53.22, OR: 3.17; p = 0.01, < 0.00001) than non-carriers. Other clinical presentations did not feature G2019S or G2385R. We observed no distinct clinical features for R1628P or R1441G. Our subgroup analyses in different ethnic group for specific variant also presented with relevant clinical characteristics of PD patients.

Conclusions: Clinical heterogeneity was observed among LRRK2-associated PD in different variants in total and in different ethnic groups, especially for G2019S and G2385R.

Long non-coding RNA CASC15 promotes tongue squamous carcinoma progression through targeting miR-33a-5p

Long non-coding RNAs (lncRNAs) have gained a lot of attention because they participate in several human disorders, including tumors. This study determined the role of LncRNA CASC15 (cancer susceptibility candidate 15) in the development of tongue squamous cell carcinoma (TSCC). Here, we identified that CASC15 expression was upregulated in TSCC samples and cell lines. We showed that overexpression of CASC15 promoted cell proliferation, cycle, and migration in TSCC. In addition, we revealed that miR-33a-5p expression was downregulated in TSCC tissues and cell lines. Moreover, we showed that the expression of CASC15 was negatively related with miR-33a-5p expression in TSCC tissues. Ectopic expression of miR-33a-5p suppressed cell proliferation, cycle, and migration in TSCC. Elevated expression of CASC15 suppressed miR-33a-5p expression and promoted ZEB1 expression in SCC4 cell. Ectopic expression of CASC15 promoted TSCC cell proliferation, cycle, and migration through targeting miR-33a-5p. These results suggested that lncRNA CASC15 and miR-33a-5p might be exploited as new markers of TSCC and were potential treatment targets for TSCC patients.

LRRK2 mutations in Parkinson disease; a sex effect or lack thereof? A meta-analysis

BACKGROUND

It is currently under debate whether there is a sex effect in LRRK2-associated Parkinson disease (PD), as several studies suggested such effect while others did not.

METHODS

All case-control studies describing LRRK2 mutations and PD were examined, and papers with data on sex and LRRK2 mutations in both patients and controls were included (n = 17) in a sex-stratified meta-analysis. Additional studies (n = 33) that included data on male:female ratio only in patients with LRRK2 mutations, were included in further analysis of male:female ratio in LRRK2-assocoiated PD patients.

RESULTS

Similar risk estimates were calculated for men and women. Among men, LRRK2 mutation carriers had a pooled OR for PD of 4.20 (95% CI 2.95-5.99, p < 0.0001) and among women, LRRK2 mutation carriers had a pooled OR for PD of 4.73 (95% CI 3.26-6.86, p < 0.0001). Similar risk estimates for men and women were also observed when analysing specific LRRK2 mutations. A total of 1080 LRRK2-associated PD patients with sex information were identified. The male:female ratio was 1.02:1.00 (50.6% men and 49.4% women).

CONCLUSION

While sporadic PD is characterized by a sex effect, with more affected men than women, LRRK2-associated PD lacks a sex effect, as typically seen in autosomal dominant traits.

Tailoring mTOR-based therapy: molecular evidence and clinical challenges

The mTOR signaling pathway integrates inputs from a variety of upstream stimuli to regulate diverse cellular processes including proliferation, growth, survival, motility, autophagy, protein synthesis and metabolism. The mTOR pathway is dysregulated in a number of human pathologies including cancer, diabetes, obesity, autoimmune disorders, neurological disease and aging. Ongoing clinical trials testing mTOR-targeted treatments number in the hundreds and underscore its therapeutic potential. To date mTOR inhibitors are clinically approved to prevent organ rejection, to inhibit restenosis after angioplasty, and to treat several advanced cancers. In this review we discuss the continuously evolving field of mTOR pharmacogenomics, as well as highlight the emerging efforts in identifying diagnostic and prognostic markers, including miRNAs, in order to assess successful therapeutic responses.

MicroRNA aberrances in head and neck cancer: pathogenetic and clinical significance

PURPOSE OF REVIEW

MicroRNAs (miRNAs) play crucial roles in modulating the neoplastic process of cancers including head and neck squamous cell carcinoma (HNSCC). miRNAs modulate pathogenesis by inhibiting target genes. Understanding how aberrant miRNAs are involved in HNSCC pathogenesis should help to validate potential clinical applications that target these entities.

RECENT FINDINGS

miR-21, miR-31, miR-504 and miR-10b are important oncogenic miRNAs that are involved in HNSCC and target tumour suppressor genes. The tumour suppressor roles of the let-7 family, the miR-99 family, miR-107, miR-133a, miR-137, miR-138 and miR-375 with respect to their targeting of oncogenes are unequivocal and have been confirmed by many studies. In addition, miR-21, let-7, miR-107, miR-138 and miR-200c seem to play complicated roles in regulating stemness or the epithelial-mesenchymal transition of tumour cells. The clinical implications of these tumour-associated miRNAs are generally in agreement with their functional roles.

SUMMARY

A number of pathways that become disregulated by aberrant miRNAs have been identified specifically for HNSCC. Analysis of these networks and their therapeutic interception might facilitate the prediction of disease status and help with the design of therapeutic trials.