My name is Jessica and I am an incoming senior majoring in Biochemistry with
a minor in Chemistry and certificates in Conceptual Foundations of Medicine and
Global Health. Outside of school, I like to run, bike, swim, and listen to
music. I intend to go to medical school after undergrad where I would like to
stay involved in research. The Health Sciences Fellowship will support my
learning in a lab setting and prepare me for medical school.
Through the Health Sciences Fellowship, I have the opportunity to continue
my research on hepatoblastoma under the guidance of Dr. Prochownik.
Hepatoblastoma (HB) is the most common form of pediatric liver cancer. Although
overall survival is high, advanced or recurrent diseases have lower cure rates
and fewer therapeutic options. Patients also suffer long-term side effects
given the combination of toxic therapies and the young age of most patients. HB
is the least genetically altered cancer with most tumors being associated with
mutant forms of the terminal transcription factors β-catenin (B), YAP (Y), and
NFE2L2 (N). HB can be expressed in mice through hydrodynamic tail vein
injection (HDTVI) of “Sleeping Beauty” (SB) vectors that overexpress B, Y, and
N. Any pairwise combination of B, Y, and N, will develop tumors with a 100%
success rate, with the overexpression of all three being the most potent. Each
pairwise combination generates HBs with distinct histologic and molecular
features that mimic those of human pathologic subtypes. My lab has recently
discovered a means to derive immortalized cell lines from murine HBs. This
involves the generation of the tumors described above along with
CRISPR/Cas9-mediated knockout of the Cdkn2a locus for the tumor
suppressor genes p16 and p19. Generating these isogenic cell lines has the
potential to accelerate the identification of new “personalized” therapies
based on the underlying oncogenic drivers. These cell lines permit simple
genetic manipulations due to their high transfection efficiency and allow us to
study how different B, Y, and N combinations impact the development of drug
resistance to different chemotherapies. HB patients are currently treated with
a “one size fits all” combination of chemotherapeutic drugs, despite the molecular
heterogeneity of their tumors. Each cell line will be used to determine whether
the identities of the oncogenic drivers impact sensitivity to the 4 drugs that
are most employed to treat primary and recurrent HB: cis-platinum, doxorubicin,
vincristine, and etoposide. To do so, standard 10-point dose response studies
with 8 replicas/doses will be performed. Individual drugs will be
simultaneously tested against all 12 cell lines using a 96 well plate format,
with cell counts being performed using a standard MTT assay and microplate
reader. We hypothesize that each group will demonstrate distinct drug
sensitivities that would be confirmed in vivo in future work. Drug resistance
is highly influenced by the underlying molecular composition of the tumors and
having isogenic HB cell lines allows us to evaluate drug resistance solely on
how B, Y, and N each contributes to differential drug sensitivities, without
the effects of somatic variations. This study would provide evidence against
the assumption that all HBs respond identically to standard chemotherapeutics
and would provide a new approach to treatment that “personalizes” chemotherapy
for HB patients based on its molecular drivers.