LOXL1-AS1 Positively Regulated the PI3K/AKT Pathway in Medulloblastoma Cell Lines The molecular mechanisms that contributed to the LOXL1-AS1-mediated phenotype were explored. (EMT). Western blot analysis further revealed that knockdown of LOXL1-AS1 decreased the phosphorylated levels of PI3K and AKT without affecting their total protein levels. These results suggest that LncRNA LOXL1-AS1 promoted the proliferation and metastasis of medulloblastoma by activating the PI3K-AKT pathway, providing evidence that knockdown of LncRNA LOXL1-AS1 might be a potential therapeutic strategy against medulloblastoma. 1. Introduction Medulloblastoma is the most common malignant brain tumor of childhood characterized with frequent extraneural metastasis . Current therapies for medulloblastoma were introduced primarily in Elvucitabine the 1980s and Rabbit polyclonal to Netrin receptor DCC consist of predominantly cytotoxic, nontargeted approaches. However, mortality from medulloblastoma remains significant . Moreover, many survivors suffer from severe treatment-related effects of radiation and cytotoxic chemotherapy such as endocrinological dysfunction and intellectual damage [3, 4]. Therefore, novel therapeutic strategies targeting crucial regulatory pathways in the development and progression of medulloblastoma are warranted. Currently, the origin of cancer is considered as a step-by-step accumulation of alterations in cell function and molecular expression, which are widely reported to relate with mechanisms involving transcriptional regulation , posttranscriptional regulation , and epigenetic modification . Among the posttranscriptional regulatory machineries, long noncoding RNAs (lncRNAs) have recently been identified as key regulators of various biological processes, including cell proliferation, differentiation, apoptosis, migration, and invasion [8C10]. lncRNAs are a class of RNA over 200 nucleotides in length. The role of lncRNAs in solid tumors has received increasing attention from worldwide studies. Moreover, lncRNAs, such as SNHG1, have Elvucitabine been associated with cancer malignancy in pan-cancer including medulloblastoma . However, our knowledge of lncRNAs remains limited, and it has become a major research challenge in discovering novel disease-related lncRNAs in cancers such as medulloblastoma . Emerging Elvucitabine data has shown the critical role of lncRNAs in the development and progression of medulloblastoma. Tumor growth and metastasis of medulloblastoma have been reported to be strictly controlled by lncRNAs such as CCAT1 , linc-NeD125 , and CRNDE . However, other critical lncRNAs Elvucitabine significantly associated with medulloblastoma remain to be elucidated. lncRNA LOXL1-antisense RNA (LOXL1-AS1) is encoded on the opposite strand of LOXL1. It is a novel lncRNA that has recently been identified using sequencing and genetic analysis . LOXL1-AS1 expression is significantly altered in response to oxidative stress in human lens epithelial cells and in response to cyclic mechanical stress in human Schlemm’s canal endothelial cells , supporting a functional role for the lncRNA LOXL1-AS1 in cellular stress response. The role of LOXL1-AS1 in human tumorigenesis remains unknown, so the present study aimed to investigate the expression profile and functional role of LOXL1-AS1 in medulloblastoma. To this end, the LOXL1-AS1 level was initially evaluated in clinical medulloblastoma tissues and in a series of medulloblastoma cell lines. Specific shRNAs targeting LOXL1-AS1 were then synthesized to modulate the expression of LOXL1-AS1. Cell viability, colony formation, and cell migration capacities were examined and was included as the internal control. Each experiment was repeated three times with each one performed in triplicate. 2.3. Western Blot Analysis Total proteins were extracted using a RIPA lysis buffer (pH?=?7.5, Beyotime Biotechnology, Nantong, China) to generate the whole protein lysate. An equal amount of 40?= 5 per group). D283 cells were pretransfected with the scramble shRNA (control) or specific shRNA1 against LOXL1-AS1 (shRNA1 group) prior to inoculation into mice. A total of 5??106 D283 cells with indicated treatments were then injected subcutaneously into the right flank in each mouse. Tumor dimensions (length, value?0.05 Elvucitabine were considered to be statistically significant. 3. Results 3.1. lncRNA LOXL1-AS1 Was Overexpressed in Medulloblastoma Initially, the expression of LOXL1-AS1 was examined in clinical medulloblastoma tissues. In the 50 cases, the mean level of LOXL1-AS1 in medulloblastoma tissues was approximately 1.5-fold that in the adjacent noncancerous tissues (Figure 1(a)). After analysis of the paired tissues, it was found that 36 of the 50 cases showed a higher level of LOXL1-AS1 in medulloblastoma tissues as compared with the paired adjacent tissues (Figure 1(b)). Moreover,.