In 2018, Dr Hong Hui Qi completed her post-graduate doctoral studies under the mentorship of Dr Polly Chen and Professor Daniel Tenen. Her research interest lies in RNA biology which is inspired by her final year project supervisor in Nanyang Technological University. Currently, she is a postdoctoral fellow working in Professor Gene Yeo’s laboratory.
In 2019, she received the Yong Loo Lin School of Medicine Best Graduate Research Publication Award. Her paper “Bidirectional regulation of adenosine-to-inosine (A-to-I) RNA editing by DEAH box helicase 9 (DHX9) in cancer” was published in Nucleic Acids Research.
Her scientific findings and achievements
The adenosine-to-inosine (A-to-I) RNA editing is catalysed by adenosine deaminases acting on RNA (ADARs). Dysregulated editing has been implicated in cancers but it still remains unknown as to what are the precise factors governing to the A-to-I editing. In this project, partial mystery has been unraveled to show that DEAH box helicase 9 (DHX9) functions as a bi-directional regulator of A-to-I editing in cancer cells. Furthermore, it is intriguing to observe there is a preferential repressive or stimulating mode of regulation by DHX9 according to ADAR substrate specificity. In other words, DHX9 silencing preferentially represses editing of ADAR1-specific substrates whereas it augments editing of ADAR2-specific substrates. Collectively, this indicates that DHX9 may therefore at least be involved in a critical mechanism in driving cancer development.
The factors that regulate the specificity and extent of ADAR editing activity have not been fully elucidated. Additionally, although there are many A-to-I RNA editing databases publicly available, yet none of these databases annotates the ADAR specificity. Hui Qi conducted a screen to study what are the interacting proteins with ADAR and splicing-associated proteins were detected. Together with literature review and domain mapping performed, she found the domains which are responsible for the ADARs-DHX9 interactions. Following then, with the use of the target-sequencing to study the ADAR specificity, she identified the first bi-directional regulator – DHX9 on ADAR editing activity.
Dr Polly Chen has been very supportive throughout Hui Qi’s PhD candidature. Whenever Hui Qi faces any obstacles in her project, she could easily approach Dr Polly for consultations and they would even troubleshoot the problems together. Dr Polly is very open-minded and often encourages Hui Qi to come forward with creative ideas to tackle the problem. Not only to her research project, Dr Polly also gives moral encouragement to Dr Hong’s personal life. This mentor-mentee pair has built sufficient rapport over the years to have mutual understanding in both research and personal goals.
Her next step
Moving on, Hui Qi will continue to pursue her research in RNA biology where there lies much excitement in this booming field awaiting to be uncovered by her.