Press Release
Nanomedicine Activation Profile Determines Efficacy
Depending on Tumor c-Myc Expression
Summary:
The plasma half-life of a potent c-Myc inhibitor JQ1H was significantly improved byencapsulating inside nano-micelle. Two types of nano-micelles were designed dependingon the tumor acidity-driven activation profile; one is fast drug-releasing (FR-JQ1H/m), andanother is slow releasing (SR-JQ1H/m). Anti-cancer activity study in mice revealed that
FR-JQ1H/m was more effective in a c-Myc high tumor, whereas SR-JQ1H/m was superiorin a c-Myc low tumor, indicating the importance of precise design of nano-micelle.
Main Body:February 26, 2021 – Kawasaki, Japan: The Innovation Center of NanoMedicine (DirectorGeneral: Prof. Kazunori Kataoka, Location: Kawasaki in Japan, Abbreviation: iCONM)
reported in “ACS Nano” (Impact Factor: 14.588 in 2019) together with the group of Prof. Yu
Matsumoto of Otorhinolaryngology and Head and Neck Surgery (Prof. Tatsuya Yamasoba)
and the group of Prof. Horacio Cabral of the Department of Bioengineering (Prof. RyoMiyake) in the University of Tokyo that the efficacy of polymeric nano-micelles with different
drug activation profile depends on the expression level of c-Myc, one of the major protooncogene, has been developed. See: https://pubs.acs.org/doi/10.1021/acsnano.1c00364
It is known that c-Myc is involved in cancer cell proliferation and angiogenesis and changes
the cell cycle, suppresses normal cell differentiation, and promotes cancer metastasis. It isa typical proto-oncogene that regulates many genes related to growth factors and is known
to be involved in developing of many cancers, such as chromosomal translocation in Burkitt
lymphoma. Therefore, drug discovery research is being conducted worldwide as an
anticancer drug targeting this transcription factor that can directly attack cancer stem cells.
However, since embryonic lethality occurs in c-Myc knockout mice, c-Myc is considered as
an essential gene for living cells, and selective delivery to cancer tissues is an important key
to developing its inhibitors. Besides, c-Myc is also known as a factor necessary for the initial
induction of iPS cells. In the future this inhibition can be expected to be applied as atechnology that can also be used to suppress iPS cell-derived carcinogenesis.
In this study, JQ1H, which is a structural analogue of JQ1, a typical indirect c-Myc inhibitor,

was encapsulated inside functional nano-micelles, and their efficacy was evaluated. JQ1
binds to a bromodomain protein called BRD4, which is involved in the activation of RNApolymerase II regulating the expression of c-Myc, to inhibit this stream strongly. As a result,the activity of RNA polymerase is weakened and c-Myc expression is down-regulated.
Although JQ1 was expected as a promising epigenome drug due to its strong gene
expression inhibition, it has an extremely short half-life in vivo due to its fast kidney excretion
and rapid clearance after administration. Additionally, JQ1 is almost insoluble in water.
These properties of JQ1 became big issues to develop it as an effective drug. The polymericnano-micelles developed so far at the Innovation Center of NanoMedicine (iCONM), for
anticancer therapy, demonstrated (1) stabilization of encapsulated drugs, (2) suppression ofkidney excretion, (3) EPR (selective drug delivery to cancer tissues) mediated tumor
accumulation, and (4) drug release based on tumor acidosis. This time, we confirmed goodantitumor activity in mice transplanted with tongue cancer, melanoma and pancreatic cancer
using JQ1-equipped nano-micelles.
Nano-micelles containing JQ1H leak into the tumor tissue from blood vessels after systemic
administration due to the so-called EPR effect. Tumor tissues are rich in lactic acid due toits enhanced glycolysis and is more acidic than normal tissues. In this work, two types ofnano-micelle were prepared; one in which hydrophobic JQ1H were linked to an amphiphilic
block polymer composed of hydrophilic polyethylene glycol block and hydrophobic polyamino acid block using 3-aminopropionaldehyde (aliphatic aldehyde) linker and the othermicelle in which JQ1H was linked with polymer via p-aminomethylbenzaldehyde (aromaticaldehyde) linker. An amphiphilic block polymer was synthesized and used as a base material
for nano-micelles (Fig. 1). When it was self-assembled in water to a micellar structure andadministered to cancer-bearing mice, the antitumor activity shown in Fig. 2 was achieved.
When the linker is an aliphatic aldehyde or when it is an aromatic aldehyde, the releasepattern of the drug differs greatly depends on the acidity. The former releases the drugrapidly, and the latter releases the drug slowly. Therefore, the former nano-medicine wasnamed FR-JQ1H/m and the latter was named SR-JQ1H/m. The antitumor activity of thesenano-micelles differ greatly depending on the expression level of c-Myc. While, FR-JQ1H/mis more effective for tumors with high c-Myc expression, SR-JQ1H/m is more effective fortumors with low c-Myc expression.
In the future, we believe that the selection of nano-micelles according to the expression
level of biomarkers will be an important step toward the realization of personalized medicine
and in-body hospitals.

Fig. 1: Different drug release profile depending on the linker used for block-copolymers of nanomicelles

FR-JQ1H/m with aliphatic aldehyde linker:
Fast drug release in gradually elevated acidity

Drug release curve of FR-JQ1 and SR-JQ
depending on the pH change of tumor tissues
SR-JQ1H/m with aromatic aldehyde linker:
Slow drug release in gradually elevated acidity

Fig.2: Anti-tumor efficacy of FR-JQ1H/m and SR-JQ1H/m depending on the expression level ofc-Myc (upper: tongue cancer, lower: pancreatic cancer)

About Nanomicelle
Polymeric micelles were one of the first polymer self-assemblies reported as a nano-DDS, andare composed of distinct two domains, a drug-loading core and a hydrophilic shell. Amphiphilic
block copolymers, containing a hydrophilic block and a hydrophobic block, are firstly revealed
to construct those distinct domains in a micelle structure through spontaneous self-assemble asa result of hydrophobic interactions in aqueous.
H. Cabral, K. Miyata, K. Osada, K. Kataoka, “Block copolymer micelles in nanomedicineapplications” Chem. Rev. 2018, 118 6844-6892. (DOI: 10.1021/acs.chemrev.8b00199)

A m p h ip h ilic b lo c k c o p o ly m e r

Self-assembly

DrugsiRNA, miRNA

Hydrophilic segment
Hydrophobic segment

TEM imageFR (Fast release)-JQ1H/m

Size : 38nm

SR (Slow release)-JQ1H/m

Size: 39nm

30〜100 nm

Public Interest Incorporated Foundation KAWASAKI INSTITUTE OF INDUSTRIAL PROMOTIONKAWASAKI INSTITUTE OF INDUSTRIAL PROMOTION was established in 1988 funded 100%from Kawasaki City for the purpose of coping with the hollowing out of industry and changes in thedemand structure.
In order to realize a higher level of market development, transforming R&D type companies, training
technological capabilities to support it, human resources development, understanding market needs,etc., by utilizing the functions of the Kawasaki, KAWASAKI INSTITUTE OF INDUSTRIALPROMOTION has been contributing to revitalize the local economy by promoting exchanges of local
industry information, advancing technology and corporate exchanges with establishment of a R&D
institutions, developing creative human resources through workshops and promoting businesses suchas expanding sales channels through exhibition business.
http://www.kawasaki-net.ne.jp/

Innovation Center of NanoMedicine (iCONM)
Innovation Center of NanoMedicine (iCONM) started its operation in April 2015 as a core research
center in life science field at King SkyFront on the request of Kawasaki city that KAWASAKIINSTITUTE OF INDUSTRIAL PROMOTION utilized national policies as a business operator andproposer.
It is a unique research center that the world has ever seen which is designed for the purpose ofpromoting open innovation through industry-academia-government/medical-engineeringcollaboration, prepared with state-of-the-art facilities and experimental equipment, that enables
comprehensive research and development from organic synthesis / microfabrication to preclinicaltesting.
https://iconm.kawasaki-net.ne.jp/en/

Center of Innovation Program (COI)The COI program is a research and development program under the Ministry of Education, Culture,Sports, Science and Technology and the Japan Science and Technology Agency. The program
employs the backcasting approach and set interdisciplinary and collaborative R&D themes thatshould be challenged at the present from the issues that are underlying in the future society. Eighteen
centers have been established nationwide to realize radical innovation through industry-academia
collaboration which cannot be accomplished by industry and academia alone.
The Kawasaki center is the only COI center managed by local governments, not universities, and theresearch projects carried out there are called COINS (Center of Open Innovation Network for Smart
Health).
COI: https://www.jst.go.jp/tt/EN/platform/coi.html
COINS: https://coins.kawasaki-net.ne.jp/en/February 26, 2021