scholarly journals The PI3K/mTOR Pathway Is Targeted by Rare Germline Variants in Patients with Both Melanoma and Renal Cell Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2243
Author(s):  
Jean-Noël Hubert ◽  
Voreak Suybeng ◽  
Maxime Vallée ◽  
Tiffany M. Delhomme ◽  
Eve Maubec ◽  
...  

Background: Malignant melanoma and RCC have different embryonic origins, no common lifestyle risk factors but intriguingly share biological properties such as immune regulation and radioresistance. An excess risk of malignant melanoma is observed in RCC patients and vice versa. This bidirectional association is poorly understood, and hypothetic genetic co-susceptibility remains largely unexplored. Results: We hereby provide a clinical and genetic description of a series of 125 cases affected by both malignant melanoma and RCC. Clinical germline mutation testing identified a pathogenic variant in a melanoma and/or RCC predisposing gene in 17/125 cases (13.6%). This included mutually exclusive variants in MITF (p.E318K locus, N = 9 cases), BAP1 (N = 3), CDKN2A (N = 2), FLCN (N = 2), and PTEN (N = 1). A subset of 46 early-onset cases, without underlying germline variation, was whole-exome sequenced. In this series, thirteen genes were significantly enriched in mostly exclusive rare variants predicted to be deleterious, compared to 19,751 controls of similar ancestry. The observed variation mainly consisted of novel or low-frequency variants (<0.01%) within genes displaying strong evolutionary mutational constraints along the PI3K/mTOR pathway, including PIK3CD, NFRKB, EP300, MTOR, and related epigenetic modifier SETD2. The screening of independently processed germline exomes from The Cancer Genome Atlas confirmed an association with melanoma and RCC but not with cancers of established differing etiology such as lung cancers. Conclusions: Our study highlights that an exome-wide case-control enrichment approach may better characterize the rare variant-based missing heritability of multiple primary cancers. In our series, the co-occurrence of malignant melanoma and RCC was associated with germline variation in the PI3K/mTOR signaling cascade, with potential relevance for early diagnostic and clinical management.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haiwei Wang ◽  
Xinrui Wang ◽  
Liangpu Xu ◽  
Ji Zhang ◽  
Hua Cao

AbstractBased on isocitrate dehydrogenase (IDH) alterations, lower grade glioma (LGG) is divided into IDH mutant and wild type subgroups. However, the further classification of IDH wild type LGG was unclear. Here, IDH wild type LGG patients in The Cancer Genome Atlas and Chinese Glioma Genome Atlas were divided into two sub-clusters using non-negative matrix factorization. IDH wild type LGG patients in sub-cluster2 had prolonged overall survival and low frequency of CDKN2A alterations and low immune infiltrations. Differentially expressed genes in sub-cluster1 were positively correlated with RUNX1 transcription factor. Moreover, IDH wild type LGG patients with higher stromal score or immune score were positively correlated with RUNX1 transcription factor. RUNX1 and its target gene REXO2 were up-regulated in sub-cluster1 and associated with the worse prognosis of IDH wild type LGG. RUNX1 and REXO2 were associated with the higher immune infiltrations. Furthermore, RUNX1 and REXO2 were correlated with the worse prognosis of LGG or glioma. IDH wild type LGG in sub-cluster2 was hyper-methylated. REXO2 hyper-methylation was associated with the favorable prognosis of LGG or glioma. At last, we showed that, age, tumor grade and REXO2 expression were independent prognostic factors in IDH wild type LGG.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Nathan D. Seligson ◽  
Richard D. Maradiaga ◽  
Colin M. Stets ◽  
Howard M. Katzenstein ◽  
Sherri Z. Millis ◽  
...  

AbstractSarcomas harboring EWSR1-NFATc2 fusions have historically been categorized and treated as Ewing sarcoma. Emerging evidence suggests unique molecular characteristics and chemotherapy sensitivities in EWSR1-NFATc2 fusion positive sarcomas. Comprehensive genomic profiles of 1024 EWSR1 fusion positive sarcomas, including 14 EWSR1-NFATc2 fusions, were identified in the FoundationCore® database. Additional data from the Gene Expression Omnibus, the Genomics of Drug Sensitivity in Cancer and The Cancer Genome Atlas datasets were included for analysis. EWSR1-NFATc2 fusion positive sarcomas were genomically distinct from traditional Ewing sarcoma and demonstrated upregulation of the mTOR pathway. We also present a case of a 58-year-old male patient with metastatic EWSR1-NFATc2 fusion positive sarcoma who achieved 47 months of disease stabilization when treated with combination mTOR and VEGF inhibition. EWSR1-NFATc2 fusion positive sarcomas are molecularly distinct entities with overactive mTOR signaling; which may be therapeutically targetable. These findings support the use of precision medicine in the Ewing family of tumors.


2014 ◽  
Vol 9 (9) ◽  
pp. 1324-1331 ◽  
Author(s):  
Shigeki Umemura ◽  
Sachiyo Mimaki ◽  
Hideki Makinoshima ◽  
Satoshi Tada ◽  
Genichiro Ishii ◽  
...  

2021 ◽  
Vol 22 (4) ◽  
pp. 1882
Author(s):  
Abdelrahman M. Elsayed ◽  
Emine Bayraktar ◽  
Paola Amero ◽  
Salama A. Salama ◽  
Abdelaziz H. Abdelaziz ◽  
...  

Many long noncoding RNAs have been implicated in tumorigenesis and chemoresistance; however, the underlying mechanisms are not well understood. We investigated the role of PRKAR1B-AS2 long noncoding RNA in ovarian cancer (OC) and chemoresistance and identified potential downstream molecular circuitry underlying its action. Analysis of The Cancer Genome Atlas OC dataset, in vitro experiments, proteomic analysis, and a xenograft OC mouse model were implemented. Our findings indicated that overexpression of PRKAR1B-AS2 is negatively correlated with overall survival in OC patients. Furthermore, PRKAR1B-AS2 knockdown-attenuated proliferation, migration, and invasion of OC cells and ameliorated cisplatin and alpelisib resistance in vitro. In proteomic analysis, silencing PRKAR1B-AS2 markedly inhibited protein expression of PI3K-110α and abrogated the phosphorylation of PDK1, AKT, and mTOR, with no significant effect on PTEN. The RNA immunoprecipitation detected a physical interaction between PRKAR1B-AS2 and PI3K-110α. Moreover, PRKAR1B-AS2 knockdown by systemic administration of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine nanoparticles loaded with PRKAR1B-AS2–specific small interfering RNA enhanced cisplatin sensitivity in a xenograft OC mouse model. In conclusion, PRKAR1B-AS2 promotes tumor growth and confers chemoresistance by modulating the PI3K/AKT/mTOR pathway. Thus, targeting PRKAR1B-AS2 may represent a novel therapeutic approach for the treatment of OC patients.


2021 ◽  
pp. 1-10
Author(s):  
Zoe Guan ◽  
Ronglai Shen ◽  
Colin B. Begg

<b><i>Background:</i></b> Many cancer types show considerable heritability, and extensive research has been done to identify germline susceptibility variants. Linkage studies have discovered many rare high-risk variants, and genome-wide association studies (GWAS) have discovered many common low-risk variants. However, it is believed that a considerable proportion of the heritability of cancer remains unexplained by known susceptibility variants. The “rare variant hypothesis” proposes that much of the missing heritability lies in rare variants that cannot reliably be detected by linkage analysis or GWAS. Until recently, high sequencing costs have precluded extensive surveys of rare variants, but technological advances have now made it possible to analyze rare variants on a much greater scale. <b><i>Objectives:</i></b> In this study, we investigated associations between rare variants and 14 cancer types. <b><i>Methods:</i></b> We ran association tests using whole-exome sequencing data from The Cancer Genome Atlas (TCGA) and validated the findings using data from the Pan-Cancer Analysis of Whole Genomes Consortium (PCAWG). <b><i>Results:</i></b> We identified four significant associations in TCGA, only one of which was replicated in PCAWG (BRCA1 and ovarian cancer). <b><i>Conclusions:</i></b> Our results provide little evidence in favor of the rare variant hypothesis. Much larger sample sizes may be needed to detect undiscovered rare cancer variants.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3111-3111
Author(s):  
Mark Andrew Dickson ◽  
Vinod Ravi ◽  
Kristen N. Ganjoo ◽  
Gopa Iyer

3111 Background: TSC1/ TSC2 genes are tumor suppressors in the mTOR pathway; mutated at low frequency across tumor types (̃1–2%). Retrospective analyses of patients (pts) with mTOR pathway mutations treated with everolimus did not show improved outcomes vs the wild type (Voss et al. Clin Cancer Res 2019. PMID 30327302). In NCT02201212, pts with TSC1/TSC2 mutations treated with everolimus had a 7% (2/30) response rate. In the AMPECT study, pts with advanced PEComa treated with a novel mTOR inhibitor (mTORi), nab-sirolimus ( nab-S, ABI-009), the subset of pts with TSC1/TSC2 mutations had a response rate of 64% (9/14) (Wagner et al. CTOS 2020. #3463014). In a xenograft model, nab-S showed significantly higher tumor accumulation, target suppression (pS6) and antitumor activity vs everolimus or sirolimus (Hou et al. AACR 2019. #348). In an expanded access program (NCT03817515), pts with advanced tumors bearing TSC1/ TSC2 mutations were treated with nab-S and outcomes in pts with malignancies other than PEComa are reported herein. Methods: Eligible pts (ECOG 0–2) received nab-S 100 mg/m2 IV, once weekly for 2 of every 3 weeks at 3 US sites between 7/2019 and 11/2020. Results: 7 pts with TSC1/ TSC2 mutations have been consecutively enrolled and are reported here. 6/7 pts had multiple prior therapies including 2 pts previously progressing on an mTORi. 4/7 pts had partial response (PR), all in mTORi naïve pts. 2/7 pts had stable disease (SD). In 2 pts previously treated with an mTORi, 1 had SD and 1 came off treatment after 1 cycle (CA125 ↑) with no follow-up scan. Treatment-related serious adverse events (SAEs; hyperglycemia and infection) and dose reduction were reported in 1 pt with metastatic angiosarcoma; SAEs resolved and the pt continued Rx. No other SAE or dose limiting event was reported Conclusions: Patients with various malignancies bearing TSC1 or TSC2 mutations, most with progression on multiple prior therapies, showed evidence of response and manageable toxicities during treatment with nab-S. A basket trial of nab-S in malignancies with TSC1/ TSC2 mutations is planned. Clinical trial information: NCT03817515. [Table: see text]


2021 ◽  
Author(s):  
Abhishek Nag ◽  
Lawrence Middleton ◽  
Ryan S Dhindsa ◽  
Dimitrios Vitsios ◽  
Eleanor M Wigmore ◽  
...  

Genome-wide association studies have established the contribution of common and low frequency variants to metabolic biomarkers in the UK Biobank (UKB); however, the role of rare variants remains to be assessed systematically. We evaluated rare coding variants for 198 metabolic biomarkers, including metabolites assayed by Nightingale Health, using exome sequencing in participants from four genetically diverse ancestries in the UKB (N=412,394). Gene-level collapsing analysis, that evaluated a range of genetic architectures, identified a total of 1,303 significant relationships between genes and metabolic biomarkers (p<1x10-8), encompassing 207 distinct genes. These include associations between rare non-synonymous variants in GIGYF1 and glucose and lipid biomarkers, SYT7 and creatinine, and others, which may provide insights into novel disease biology. Comparing to a previous microarray-based genotyping study in the same cohort, we observed that 40% of gene-biomarker relationships identified in the collapsing analysis were novel. Finally, we applied Gene-SCOUT, a novel tool that utilises the gene-biomarker association statistics from the collapsing analysis to identify genes having similar biomarker fingerprints and thus expand our understanding of gene networks.


2020 ◽  
Author(s):  
Peihong Shao ◽  
Chengshi Wei ◽  
Yun Wang

Abstract Background: In this study, we planned to investigate the function and potential mechanisms of Alpha-1,3-mannosyltransferase (ALG3) in oral squamous cell carcinoma (OSCC). Methods: Data from The Cancer Genome Atlas (TCGA) was used to analyze ALG3 expression and its effect on the prognosis of patients with OSCC. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was applied to explore the signaling pathways related to ALG3. In OSCC cells, ALG3 expression was measured by qPCR and western blot. Cell counting kit-8, colony formation, and transwell assays were implemented to detect the effects of ALG3 on the malignant biological properties OSCC cells. The expression of key proteins related to CDK-Cyclin pathway was detected by western blot. Results: The expression of ALG3 in OSCC samples was higher than that of the control samples, and the increase of ALG3 expression was related to unfavorable prognosis of OSCC patients. Additionally, the elevated expression of ALG3 was associated with pathological stage, lymph node metastasis and primary lesion in OSCC patients. ALG3 depletion blocked the growth, colony formation, invasion and migration of OSCC cells, while over-expression ALG3 reversed these phenomena. Moreover, exhaustion of ALG3 resulted in decreased expression of MCM7, CCNB2, CDK1 and PCNA, while these phenomena were inversed after ALG3 up-regulation. Conclusions: The enhancement of ALG3 expression promoted the aggressive biological behaviors of OSCC cells probably by promoting CDK-Cyclin pathway.


TH Open ◽  
2020 ◽  
Vol 04 (04) ◽  
pp. e322-e331
Author(s):  
Eric Manderstedt ◽  
Christina Lind-Halldén ◽  
Stefan Lethagen ◽  
Christer Halldén

AbstractGenome-wide association studies (GWASs) have identified genes that affect plasma von Willebrand factor (VWF) levels. ABO showed a strong effect, whereas smaller effects were seen for VWF, STXBP5, STAB2, SCARA5, STX2, TC2N, and CLEC4M. This study screened comprehensively for both common and rare variants in these eight genes by resequencing their coding sequences in 104 Swedish von Willebrand disease (VWD) patients. The common variants previously associated with the VWF level were all accumulated in the VWD patients compared to three control populations. The strongest effect was detected for blood group O coded for by the ABO gene (71 vs. 38% of genotypes). The other seven VWF level associated alleles were enriched in the VWD population compared to control populations, but the differences were small and not significant. The sequencing detected a total of 146 variants in the eight genes. Excluding 70 variants in VWF, 76 variants remained. Of the 76 variants, 54 had allele frequencies > 0.5% and have therefore been investigated for their association with the VWF level in previous GWAS. The remaining 22 variants with frequencies < 0.5% are less likely to have been evaluated previously. PolyPhen2 classified 3 out of the 22 variants as probably or possibly damaging (two in STAB2 and one in STX2); the others were either synonymous or benign. No accumulation of low frequency (0.05–0.5%) or rare variants (<0.05%) in the VWD population compared to the gnomAD (Genome Aggregation Database) population was detected. Thus, rare variants in these genes do not contribute to the low VWF levels observed in VWD patients.


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