Tabouret E, etal., J Neurol Sci. 2015 Nov 15;358(1-2):440-3. doi: 10.1016/j.jns.2015.09.345. Epub 2015 Sep 11.
INTRODUCTION: Deletion of the tumor suppressor gene LRP1B has been reported in glioblastoma, the most aggressive primary brain tumor in adults. Our objective was to analyze frequency and prognostic impact of LRP1B deletion a
nd expression levels. METHODS: We retrospectively included all the primary IDH1/2 wild-type GBM patients with available clinical follow-up, DNA and RNA from our database. Deletions were analyzed by SNP-array. LRP1B mRNA expression was analyzed by reverse transcription quantitative polymerase chain reaction. RESULTS: 178 patients were included with a median age of 62.36 years. LRP1B deletions were observed for 10.1% of patients (complete: 2.8%, partial: 7.3%). LRP1B deletions were associated with poor progression-free survival (PFS) (p=0.004) and overall survival (OS) (p=0.001). By multivariate analysis, LRP1B deletions remained significant for both PFS (p=0.003, hazard ratio (HR): 2.261) and OS (p=0.001, HR: 2.609). LRP1B was down expressed with a mean relative expression of 46% comparatively to normal tissue. No association between LRP1B mRNA and patient outcome was observed. No correlation was found between the deletions and the mRNA down-expression. These results were validated using GBM TCGA data. CONCLUSION: LRP1B presents with frequent molecular alterations which impact patient outcome, highlighting the potential interest of this gene for glioblastoma patients.
Li M, etal., J Hepatocell Carcinoma. 2020 Dec 8;7:361-376. doi: 10.2147/JHC.S279123. eCollection 2020.
Background: To date, aberrated lipid metabolism has been recognized as an important feature of hepatocellular carcinoma (HCC); however, it remains poorly defined. As a large member of the low-density lipoprotein receptor family, LRP1B plays a pivotal
role in maintaining lipid homeostasis. Here we investigated the expression feature of LRP1B in HCC and elucidated its effects on lipid metabolism of HCC cells. Materials and Methods: LRP1B expression in HCC cells and tumor tissues was respectively examined by quantitative PCR, Western blotting and immunohistochemistry. Crispr-cas9 RNA inference and CRISPRa transcription activation system were used to downregulate and upregulate LRP1B expression, respectively. Oil red O staining, DiD staining combined with flow cytometry and transmission electron microscopy were used to evaluate the lipid content in HCC cells. Overall survival (OS) and time to recurrence (TTR) were calculated; meanwhile, Kaplan-Meier and the Cox proportional hazards model were used to assess the prognosis of HCC patients. Results: In contrast to inactivation expression in a majority of cancers, LRP1B showed predominantly strong expression in HCC. LRP1B knockdown induced the decrease of intracellular lipid content, downregulated expressions of lipid synthesis-related enzymes and upregulated expressions of β-oxidation-related enzymes as well as activated the AMPK signaling. Moreover, HSF1 directly regulated the transcription of LRP1B and was involved in LRP1B-mediated lipid metabolism in HCC; meanwhile, the combination of LRP1B knockdown and HSF1 inhibition suppressed synergistically the proliferation of HCC cells. In addition, simultaneous expression of HSF1 and LRP1B was an independent prognostic factor for HCC patients. Conclusion: Altogether, the study reveals a novel unique role of LRP1B in HCC by serving as a mediator in lipid metabolism, which provides an insight for making explorable therapeutic strategies for HCC.
Wang Z, etal., Exp Cell Res. 2017 Aug 1;357(1):1-8. doi: 10.1016/j.yexcr.2017.04.010. Epub 2017 Apr 11.
Aberrant activation of beta-catenin/TCF signaling is one of the hallmarks of colon cancer. It is of great interest to study the mechanism for the regulation of beta-catenin/TCF signaling. In this study, it was found that LRP1B was down-regulated in colon cancer
tissues and inhibited the growth, migration and metastasis of colon cancer cells. The molecular mechanism study revealed that LRP1B interacted with DVL2, inhibited the interaction between DVL2 and Axin, and negatively regulated beta-catenin/TCF signaling. Taken together, our study demonstrated the suppressive roles of LRP1B in the progression of colon cancer, implicating that restoring the function of LRP1B would be a promising strategy for the treatment of colon cancer.
Chen H, etal., Front Immunol. 2019 May 21;10:1113. doi: 10.3389/fimmu.2019.01113. eCollection 2019.
Background: Tumor mutation burden (TMB) have been served as the most prevalent biomarkers to predict immunotherapy response. LRP1B (low-density lipoprotein receptor-related protein 1B) is frequently mutated in melanoma, non-small cell lung cancer (NSCLC) and oth
er tumors; however, its association with TMB and survival in patients with immunotherapy remains unknown. Methods: We curated somatic mutation data and clinicopathologic information from 332 melanoma immunotherapy samples for discovery and 113 NSCLC samples for further corroboration. Bayesian variants non-negative matrix factorization was used to extract tumor mutational signatures. Multivariate Cox and logistic regression models were applied to adjust confounding factors. The CIBERSORT and GSEA algorithm were separately used to infer leukocyte relative abundance and significantly enriched pathways. Results: Patients with LRP1B mutation were identified to be associated with prolonged survival in both immunotherapy cohort. Higher tumor mutation burden was found in LRP1B mutated patients, and the association remained significant after controlling for age, gender, stage, mutations in TP53 and ATR, and mutational signatures. Immune response and cell cycle regulation circuits were among the top enriched pathways in samples with LRP1B mutations. Conclusion: Our studies suggested sequencing even a single, frequently mutated gene may provide insight into genome-wide mutational burden, and may serve as a biomarker to predict immune response.
Benoit ME, etal., J Biol Chem. 2013 Jan 4;288(1):654-65. doi: 10.1074/jbc.M112.400168. Epub 2012 Nov 13.
Complement protein C1q is induced in the brain in response to a variety of neuronal injuries, including Alzheimer disease (AD), and blocks fibrillar amyloid-β (fAβ) neurotoxicity in vitro. Here, we show that C1q protects immature and mature primary neurons against fAβ toxicity, and we report for the
first time that C1q prevents toxicity induced by oligomeric forms of amyloid-β (Aβ). Gene expression analysis reveals C1q-activated phosphorylated cAMP-response element-binding protein and AP-1, two transcription factors associated with neuronal survival and neurite outgrowth, and increased LRP1B and G protein-coupled receptor 6(GPR6) expression in fAβ-injured neurons. Silencing of cAMP-response element-binding protein, LRP1B or GPR6 expression inhibited C1q-mediated neuroprotection from fAβ-induced injury. In addition, C1q altered the association of oligomeric Aβ and fAβ with neurons. In vivo, increased hippocampal expression of C1q, LRP1B, and GPR6 is observed as early as 2 months of age in the 3 × Tg mouse model of AD, whereas no such induction of LRP1B and GPR6 was seen in C1q-deficient AD mice. In contrast, expression of C1r and C1s, proteases required to activate the classical complement pathway, and C3 showed a significant age-dependent increase only after 10-13 months of age when Aβ plaques start to accumulate in this AD model. Thus, our results identify pathways by which C1q, up-regulated in vivo early in response to injury without the coordinate induction of other complement components, can induce a program of gene expression that promotes neuroprotection and thus may provide protection against Aβ in preclinical stages of AD and other neurodegenerative processes.
Shang Z, etal., Oncotarget. 2015 Dec 15;6(40):42504-14. doi: 10.18632/oncotarget.6391.
Alzheimer's disease (AD) is an acquired disorder of cognitive and behavioral impairment. It is considered to be caused by variety of factors, such as age, environment and genetic factors. In order to identify the genetic affect factors of AD, we carried out a bioinformatic approach which combined g
enome-wide haplotype-based association study with gene prioritization. The raw SNP genotypes data was downloaded from GEO database (GSE33528). It contains 615 AD patients and 560 controls of Caribbean Hispanic individuals. Firstly, we identified the linkage disequilibrium (LD) haplotype blocks and performed genome-wide haplotype association study to screen significant haplotypes that were associated with AD. Then we mapped these significant haplotypes to genes and obtained candidate genes set for AD. At last, we prioritized AD candidate genes based on their similarity with 36 known AD genes, so as to identify AD related genes. The results showed that 141 haplotypes on 134 LD blocks were significantly associated with AD (P<1E-4), and these significant haplotypes were mapped to 132 AD candidate genes. After prioritizing these candidate genes, we found seven AD related genes: APOE, APOC1, TNFRSF1A, LRP1B, CDH1, TG and CASP7. Among these genes, APOE and APOC1 are known AD risk genes. For the other five genes TNFRSF1A, CDH1, CASP7, LRP1B and TG, this is the first genetic association study which showed the significant association between these five genes and AD susceptibility in Caribbean Hispanic individuals. We believe that our findings can provide a new perspective to understand the genetic affect factors of AD.
Xiao D, etal., Sci Rep. 2017 May 18;7(1):2121. doi: 10.1038/s41598-017-02405-9.
Both chronic Obstruction Pulmonary Disease (COPD) and lung cancer are leading causes of death globally. Although COPD and lung cancer coexist frequently, it is unknown whether lung cancer patients with COPD harbor distinct genomic characteristics compared to those without COPD. In this study, we ret
rospectively analyzed genomic sequencing data from 272 patients with lung adenocarcinoma (LUAD) and compared the genetic alterations in LUAD patients with and without COPD. Integrative analysis of whole-genome and exome sequencing data revealed that COPD and non-COPD groups showed high concordance in mutational burden and spectra. Notably, we also found that EGFR mutations were more prevalent in LUAD patients without COPD, whereas mutated LRP1B was more frequently observed in LUAD patients with COPD. In addition, multi-variable analysis with logistic regression demonstrated that mutation of LRP1B was a predictive marker for the presence of COPD in the patients with LUAD. Our analysis demonstrated for the first time the high concordance in genomic alterations between the tumors from LUAD patients with and without COPD. We also identified higher prevalence of LRP1B among the LUAD patients with COPD, which might help understand the underlying mechanisms which link COPD and lung cancer.
Wang L, etal., J Cancer. 2021 Jan 1;12(1):217-223. doi: 10.7150/jca.48983. eCollection 2021.
Background: Hepatocellular carcinoma (HCC) is one of the most leading causes of cancer-related mortality worldwide. Immune checkpoint inhibitors (ICIs) have been proved to be beneficial for advanced HCC. Tumor mutational burden (TMB) is an important predictor for efficacy of ICIs. However, the genet
ic landscape of Chinese HCC patients and the association between TMB and frequently mutated genes of HCC remain unclear. Methods: Whole-exome sequencing data of 369 liver tumors from the Cancer Genome Altas (TCGA) and next generation sequencing (NGS) data of 657 liver tumors from Chinese clinical dataset were included. Results: TP53 (61.8%) was the most frequently mutated gene in the Chinese cohort, followed by CTNNB1 (17.2%), RB1 (13.7%), and LRP1B (12.3%). The PI3K-Akt signaling (11.2%), the Rap1 signaling (8.1%), and Ras signaling (7.7%), were significantly mapped. LRP1B mutations were significantly associated with higher TMB in both TCGA cohort (P = 0.0003) and Chinese cohort (P = 0.0005). And TP53 mutations were also associated with higher TMB in the TCGA and Chinese cohort (P = 0.0005 and 0.0010, respectively). Prognosis analysis performed in TCGA cohort revealed LRP1B mutations were significantly associated with shorter overall survival (OS, median, 20.9 vs 61.7 months; HR, 2.22; P = 0.0012). TP53 mutation was an independent risk factor affecting both OS (HR 1.58, P = 0.0109) and PFS (HR 1.59, P = 0.0027). Conclusions: The results suggest that LRP1B or TP53 mutations are associated with higher TMB and a poor prognostic factor in HCC.
AIM: To assess the associations between gestational diabetes mellitus (GDM) and DNA methylation levels at genes related to energy metabolism. PATIENTS & METHODS: Ten loci were selected from our recent epigenome-wide association study on GDM. DNA methylation levels were quantified by bisulfite pyrose
quencing in 80 placenta and cord blood samples (20 exposed to GDM) from an independent birth cohort (Gen3G). RESULTS: We did not replicate association between DNA methylation and GDM. However, in normoglycemic women, glucose levels were associated with DNA methylation changes at LRP1B and BRD2 and at CACNA1D and LRP1B gene loci in placenta and cord blood, respectively. CONCLUSION: These results suggest that maternal glucose levels, within the normal range, are associated with DNA methylation changes at genes related to energy metabolism and previously associated with GDM. Maternal glycemia might thus be involved in fetal metabolic programming.
Vorspan F, etal., Transl Psychiatry. 2020 Nov 6;10(1):381. doi: 10.1038/s41398-020-01050-7.
Motor disturbances strongly increase the burden of cocaine use disorder (CUDs). The objective of our translational study was to identify the genes and biological pathways underlying the tolerance to cocaine-induced motor effects. In a 5-day protocol measuring motor tolerance to cocaine in rats (N =
40), modeling the motor response to cocaine in patients, whole-genome RNA sequencing was conducted on the ventral and dorsal striatum to prioritize a genetic association study in 225 patients with severe CUD who underwent thorough phenotypic (cocaine-induced hyperlocomotion, CIH; and cocaine-induced stereotypies, CIS) and genotypic [571,000 polymorphisms (SNPs)] characterization. We provide a comprehensive description of the rat striatal transcriptomic response to cocaine in our paradigm. Repeated vs. acute cocaine binge administration elicited 27 differentially expressed genes in the ventral striatum and two in the dorsal striatum. One gene, Lrp1b, was differentially expressed in both regions. In patients, LRP1B was significantly associated with both CIS and CIH. CIH was also associated with VPS13A, a gene involved in a severe neurological disorder characterized by hyperkinetic movements. The LRP1B minor allele rs7568970 had a significant protective effect against CIS (558 SNPs, Bonferroni-corrected p = 0.02) that resisted adjustment for confounding factors, including the amount of cocaine use (adjusted beta = -0.965 and -2.35 for heterozygotes and homozygotes, respectively, p < 0.01). Using hypothesis-free prioritization of candidate genes along with thorough methodology in both the preclinical and human analysis pipelines, we provide reliable evidence that LRP1B and VPS13A are involved in the motor tolerance to cocaine in CUD patients, in line with their known pathophysiology.
