Högskolan i Skövde

Background: LIN7 are a group of proteins that play a pivotal role in membrane protein localization and are thus important for cell adhesion and polarity. LIN7 proteins are shown to be important in neuroblastoma outcome, possibly through interactions with Disc-Large proteins (DLG). DLG2 has been shown to directly affect the regulation of LIN7A. Previous studies into the role of LIN7 have given conflicting results as to its nature.

Methods: In this study we transfected LIN7A and LIN7C in SK-N-AS cells through the use of plasmids for upregulation and siRNA for knockdown of these genes. We also evaluated the expression levels of specific genes related to pathways such as PI3K, autophagy/lysosomal activity, AKT, etc., both independently and related to LIN7 expression through the R2 platform. Genes of interest were selected and then analyzed through qPCR.

Results: Many of the genes that were significantly correlated when compared to LIN7A/C through R2 showed no significant expression correlation after experimentation. Some more functionally close genes to LIN7 were affected in a more predictable way such as CASK being upregulated after LIN7 knockdown, PTEN being downregulated upon LIN7 plasmid transfection while others such as FOXO3 also showed significant alterations.

Conclusion: Many of the pathways discussed in this study are better studied through protein analysis due to the nature of the function of LIN7 proteins, however some downstream transcript changes were analyzed. Unexpectedly, the knockdown of both LIN7A and LIN7C displayed similar behavior to upregulation of LIN7A or LIN7C, possibly meaning that extreme expression differences have similar regulatory outcomes for some affected genes.