A systematic review with in silico analysis on transcriptomic profile of gallbladder carcinoma

Gallbladder cancer (GBC) is an aggressive malignancy of the biliary tract. It is asymptomatic in its early stages, and often, characterized by a poor prognosis and worse treatment response. Distribution of GBC shows both geographical as well as ethnic variations. Several studies have elucidated the differential gene expression profile between the normal gallbladder and GBCs, with varied but inconsistent results. Thus, a deep understanding of the expression profile of GBC might aid in the identification of potential biomarkers, which would further help in better disease management and appropriate therapy selection. This review summarizes studies on the transcriptomic profile of GBC with emphasis on studies pertaining to coding (mRNA) and noncoding (micro and long noncoding) RNA along with aberrant promoter methylation studies, ranging from a single gene to global gene to high throughput RNA sequencing approaches, published between 2000 to May, 2019. In addition, data mining of GBC from the available public functional genomics data repository at Gene Expression Omnibus has been done to rule out potentially important dysregulated genes in this malignancy. To the best of our knowledge, this is the first article to shed light on the RNA based gene regulatory network(s) along with bioinformatic analysis. Moreover, this review represents major research challenges and ambiguity, knowledge of which is a must for establishing molecular/ clinical biomarkers for early GBC diagnosis, management, and treatment protocols.