Identification and validation of a novel long non-coding RNA (LINC01465) in ovarian cancer.

Epithelial Ovarian Cancer (EOC) is a heterogeneous disease usually diagnosed at advanced stages. Therefore, early detection is crucial for better survival. Despite the advances in ovarian research, mechanisms underlying EOC carcinogenesis are not elucidated. We performed chromatin immunoprecipitation sequencing to identify genes regulated by E2F5, a transcription factor involved in ovarian carcinogenesis. Results revealed several putative candidate genes (115 protein-coding genes, 20 lncRNAs, 6 pseudogenes, and 4 miRNAs). A literature review and bioinformatics analysis of these genes revealed a novel lncRNA candidate (LINC01465) in EOC. We validated LINC01465 by quantifying its expression in EOC cell lines and selected OVSAHO and SKOV3 as a model with high LINC01465 levels. We silenced LINC01465 and performed proliferation, wound healing, invasion, and drug resistance assays. Knocking-down LINC01465 resulted in reduced migration, suggesting potential involvement in EOC. Furthermore, to identify the significance of LINC01465 in chemoresistance, we assessed the LINC01465 levels in A2780 S cells treated with malformin, which revealed higher LINC01465 expression as compared to untreated A2780S cells implying the involvement of LINC01465 in cell death. Thus, this study unraveled the repertoire of E2F5 regulated candidate genes and suggested a putative role of LINC01465 in malformin-induced cell death in EOC.

The Genetic Spectrum of Familial Hypertriglyceridemia in Oman.

Familial hypertriglyceridemia (F-HTG) is an autosomal disorder that causes severe elevation of serum triglyceride levels. It is caused by genetic alterations in LPL, APOC2, APOA5, LMF1, and GPIHBP1 genes. The mutation spectrum of F-HTG in Arabic populations is limited. Here, we report the genetic spectrum of six families of F-HTG of Arab ancestry in Oman. Methods: six Omani families affected with triglyceride levels >11.2 mmol/L were included in this study. Ampli-Seq sequencing of the selected gene panels was performed. Whole-exome sequencing and copy number variant analysis were also performed in cases with negative exome results. Three novel pathogenic missense variants in the LPL gene were identified, p.M328T, p.H229L, and p.S286G, along with a novel splice variant c.1322+15T > G. The LPL p.H229L variant existed in double heterozygous mutation with the APOA5 gene p.V153M variant. One family had a homozygous mutation in the LMF1 gene (c.G107A; p.G36D) and a heterozygous mutation in the LPL gene (c.G106A; p.D36N). All affected subjects did not have a serum deficiency of LPL protein. Genetic analysis in one family did not show any pathogenic variants even after whole-exome sequencing. These novel LPL and APOA5 mutations are not reported in other ethnic groups. This suggests that patients with F-HTG in Oman have a founder effect and are genetically unique. This warrants further analysis of patients of F-HTG in the Middle East for preventative and counseling purposes to limit the spread of the disease in a population of high consanguinity.