1. A C4-2 B SVHUC
(A) ASC-J9® treatment can decrease division ability in PCa (B) but not on
normal bladder cells. It will not rise the risk of radiation cystitis.
ASC-J9® increases RT efficacy on PCa and only results in minor effects
Uroepithelium
B
A
ASC-J9® treatment increases IR induced DNA damage via modulating
ROS and GSH
(A)ASC-J9® + IR treatment increases the tail/body ratio in alkaline comet assay
(B)In DCF-DA test, IR+ ASC-J9® treatment further increases the cytoplasmic
ROS level.
(C) ASC-J9® treatment decreases the endogenous GSH level.
A B C
Androgen receptor (AR) degradation enhancer ASC-J9® enhances the efficacy
of radio-therapy and suppresses prostate cancer progression
Fu-Ju Chou, Yuhchyau Chen, Yin Sun, Peter Keng, Shuyuan Yeh and Chawnshang Chang#
George Whipple Lab for Cancer Research, Departments of Pathology, Urology, Radiation Oncology and The Wilmot Cancer Center, University of Rochester
Medical Center, Rochester, NY 14642, USA
ASC-J9® can radio-sensitize PCa and delay the tumor regrowth
A
ASC-J9® causes cell bypass IR induced G2M phase block
(A) ATR-CHK1 involves in this cell cycle regulation.
(B) ASC-J9® treatment results in PCa cells bypass G2/M block, and leads to
mitotic catastrophe.
C
TR
L
J9
4G
y
IR
4G
y
IR
+
J9
0
50
100
G0G1
S
G2M
Sub G0G1
%ofcellcycle
C4-2
DM
SO
J9
2.5uM
IR
IR
+J9
2.5
uM
0
2
4
6
8
RelativeFolds
C4-2
DM
SO
J9
2.5uM
0
50000
100000
ASC-J9® +IR triggers apoptosis in PCa, does not affect on bladder cells
A B C
(A) ASC-J9® +IR or (B) shAR lentivirus infection can enhance PCa apoptosis
(C) ASC-J9® +IR treatment have no extra effects on normal bladder cells
ASC-J9® treatment results in double strand breaks persistence
(A) ASC-J9® +IR treatment increases total amount of γ-H2Ax in PCa (B) In
ICC staining, ASC-J9® treatment+ IR increases the nuclear γ-H2Ax foci
A B
DCF-DA GSH
**
******
A B
ASC-J9® treatment reduces homologous recombination repair
Goal:
1. Increase efficacy of radiotherapy
2. Do not further cause side effect
Radiation
cystitis
Application of External Beam Radiotherapy (EBRT)
1. In early stage provide about the same cure rates as surgery
2. Along with hormone therapy for cancers that have grown
outside of the prostate gland and into nearby tissues.
3. Cancer is not removed completely or recurs.
4. Reduce the size of the tumor to provide relief from symptoms.
Modified from nih.gov website (A) Homologous recombination repair (HR) assay (B) ASC-J9® treatment
suppresses GFP+ signal (HR) in HEK293T/DF-GFP and I-Sce I transfectant.
A B
EBRT
(A-B) ASC-J9® +IR treatment delays the tumor regrowth after radiation therapy
(C) In c-PARP staining ASC-J9® + IR increases apoptosis population (4 days)
C4-2
Mergeγ-H2Ax
DMSO J9 4Gy IR 4Gy IR+J9
C4-2 Xenograft
0 4 8 12 16 20 24
0
2
4
6
J9
IR
IR+J9
Ctrl
Days
Tumorsizechange(fold)
B
C
Result
Conclusion
***
*
• ASC-J9® can enhance the radiotherapy efficacy but
not further damage neighboring bladder cells.
• ASC-J9® can suppress AR associated DDR genes,
repress the homologous recombination repair.
• ASC-J9® regulates cell cycle via AR-ATR-CHK1
pathway and further induce mitotic catastrophe and
apoptosis.
• The unique structure of ASC-J9® increases the ROS
level which can enhance the IR induced DNA damage.
Prostate cancer (PCa) remains the most common cancer type and the second-leading cause of cancer deaths in men in the U.S. At low-grade localized (clinical stage T1-2a) and local
advanced (clinical stage <T2c) PCa, Radiotherapy(RT) provides a similar cure rate as prostatectomy. In addition, adjuvant RT (after surgery) was proved to efficiently reduce the risk of biochemical
recurrence. Although RT destroys cancer effectively, it also damages healthy cells and the neighboring tissues, which leads to unwanted side effects (e.g. radiation cystitis). The goal of our study is
developing a radio-sensitizer that can make PCa cells much more sensitive to RT and minimize the possible side effects. Both published work and our preliminary data demonstrate RT might result in
elevation of the androgen receptor (AR), which might then increase the expression of AR associated DNA damage response (DDR) genes, and further result in radio-resistance and failure of subsequent
ADT. To target this Ionizing radiation (IR)-induced AR, we applied the recently developed compound ASC-J9® that can enhance AR degradation and suppress the AR downstream signaling pathway.
Mechanism dissection revealed that ASC-J9®,but not other anti-androgens (Casodex or Enzalutamide) could suppress AR and AR associated DDR genes, abolish homologous recombination repair,
reactivate the ATR/Chk1-mediated G2/M cell cycle arrest, thus resulting in the IR-induced mitotic catastrophe (genome instability), and further trigger apoptosis. In addition, the unique polyphenol
structure of ASC-J9® also elevates reactive oxygen species (ROS) and suppresses the glutathione antioxidant system that result in PCa cells becoming much more sensitive to IR treatment. Importantly,
results from xenograft athymic mouse model also demonstrated that combining IR with ASC-J9® was significantly better in inhibiting tumor growth than RT or ASC-J9® treatment alone. These results
suggest that using ASC-J9® as a radiosensitizor has potential to provide benefit in PCa patients.
Abstract
