Efficacy of M-BH33, the new BH3 mimetic drug on Mega BCL-2

Efficacy of M-BH33, the new BH3 mimetic drug on Mega BCL-2 protein
Rationale
The utilisation of mice in cancer research has been significant owing to its similarity in
genomic, anatomical, molecular and physiological characteristics of cancer biology with
humans (Tratar et al., 2018). In addition, mice reproduce rapidly, easy to maintain in the
laboratory and provides the capability to assess the etiology of the disease at a low cost.
Despite conventionally immune-deficient mice with grafted tumours have been utilised
earlier, the emergence of transgenic mouse models have been potential over the past three
decades. In 2007, the Federation of European Laboratory Animal Science Associations
specified that transgenic mice are those that are involved with spontaneous and chemically
induced mutations. Furthermore, the National Institute of Health and the National Cancer
Institute specifically define transgenic mouse as those where the DNA from the genome of
mouse or other species is incorporated into the genome of the mouse model. They are also
collectively referred as germ-line genetically engineered mouse models (GEMM).
Currently, the focus has shifted from studying spontaneous and chemically-induced mouse
models to study the expression and function of genes via knockin and knockout approach
(Kersten et al., 2016). As such, various approaches such as i) retroviral infection of mouse
embryos during development, ii) standard transgene-based method via microinjection od
DNA constructs into the nucleus of fertilised oocytes of mouse iii) and gene-targeted
transgene-based manipulation of the embryonic stem cells at a particular loci leading to a
primary loss of function mutations (Fig 1). Transgenic mice can be categorised into two
groups based on the loss (knockout model) or gain (knock-in model) of the functional genes.
The loss of function provides information about the function of a normal gene. Two types of
knockout models are frequently utilised, i) constitutive where the gene expression is

permanently inactivated in each cell of the mouse and ii) conditional where the gene
expression undergoes inducible inactivation directly affective the target.
On the contrary, the gain of function reveals information about overexpression of oncogenes
and its effect in carcinogenesis. Four different knock-in models are used, i) constitutive
random insertion model, knock-in permissive locus model, conditional knock-in model and
reporter knock-in model. In addition to the aforementioned transgenic mouse models, new
models have such as non-germline genetically engineered mouse models and alternative
DNA modification techniques such as transposon based insertion mutagenesis, RNA
interference, engineered nucleases and CRISPR/Cas9 system have emerged in studying the
expression of oncogenes.
Mega BCL-2 protein regulates the mitochondrial apoptotic response, thereby possessing the
ability to suppress apoptosis leading to the development of cancer (Hata et al., 2015).
Furthermore, BH3 mimetic drugs offer a new chemotherapy for cancer by binding to BCL-2
family members and neutralizing the anti-apoptotic effect (Merino et al.,2018). Henceforth,
in this study, a transgenic mouse model will be created with the overexpression of Mega
BCL-2 protein. Additionally, M-BH33, a new BH3 mimetic will be inventedand administered
to evaluate its impact on the expression of Mega BCL-2 protein in the transgenic mouse
model.
Hypothesis
 Overexpression of Mega BCL-2 protein in a transgenic cell could suppress apoptosis
and stimulate carcinogenesis
 The new drug M-BH33 inhibits the anti-apoptotic protein Mega BCL-2 from
proliferation
 The drug leads to overexpression of BH3 pro-apoptotic protein