Page 47 - ebook

Senescent Tumor Cell from Colorectal Cancer
Accelerates Pre-metastatic Niche Formation in the Liver

Soon Sang Park 1,2,4* , Ga-Yeon Lee 1,4 ,Young-Kyoung Lee 1,4 ,So Hyun Park 1,3,4 , Ji Hee Park , Chan Young Lee , Dong Hyun Lee ,
1,4
1,2
1,2
Jang-Hee Kim 3,4† & Tae Jun Park 1,2,4 †
1 Department of Biochemistry and Molecular Biology, Ajou University School of Medicine Suwon 16499, Korea;
2 Department of Biomedical Sciences, Ajou University Graduate School of Medicine Suwon 16499, Korea;
3 Department of Pathology, Ajou University School of Medicine Suwon 16499, Korea;
4 Inflamm-Aging Translational Research Center, Ajou University Medical Center Suwon 16499, Korea;
* Presenting Author † Corresponding Authors
Introduction A Figure 2 B Mouse IP injection model
Liver metastasis
Primary colorectal cancer
Control CM Senescent CM
p16 INK4A p16 INK4A Tumor CD11b Tumor
Cellular senescence implies permanent cell cycle arrest caused by various
internal/external insults such as excessive replicative stress hypoxia, cytotoxic agents, CD11b
reactive oxygen species (ROS), etc. Generally, cellular senescence is considered as a part Non-tumor 200 μm 200 μm
of aging process. Therefore, senescent cells are often found in age-related disorders such 5 mm 5 mm 5 mm Non-tumor
as osteoarthritis, cataract, and glaucoma. However, paradoxically, senescent cells are p16 INK4A (-) patient C D
found in various kind of cancer tissues although they are not proliferative. Especially,
numerous non-proliferative cancer cells, called senescent tumor cells, are easily found in
cancer tissues. However, they are firstly recognized as a defense mechanism of our body
200 μm 200 μm 200 μm
against cancer progression by inhibiting active proliferation of cancer cells. However,
p16 INK4A p16 INK4A Non-tumor CD11b Non-tumor
recent studies have been reporting that they rather promote cancer progression by
releasing senescent-associated secreting phenotypes (SASPs). Our previous study Tumor Tumor
showed that the presence of senescent tumor cell is closely related to the increased local
invasion and lymph node metastasis. From this background, we hypothesized that 5 mm 5 mm 5 mm
senescent tumor cells from colorectal cancer (CRC) may promote distant metastasis by p16 INK4A (+) patient E
changing the liver microenvironment to metastasis-prone state, called ‘metastatic niche’.
The aim of this study is to figure out the phenotype of pre-metastatic organ which is NC Control CM Senescent CM PC CD11b (~170 kD)
induced by senescent tumor cells from primary cancer in human and in vivo mouse model. α-Tubulin (~55 kD)
200 μm 200 μm 200 μm
F G H I
Control CM Senescent CM
Results
Myeloperoxidase
Figure 1
A B C
Primary colorectal cancer Primary colorectal cancer
p16 INK4A p16 INK4A Negative p16 INK4A 1+ Ly6C
Patient #1

5 mm 200 μm 200 μm 200 μm
p16 INK4A p16 INK4A 2+ p16 INK4A 3+ F4/80
Patient #2

5 mm 200 μm 200 μm 200 μm p-value is obtained from
Chi-square test
D E
Liver metastasis Clec4f
Primary colorectal cancer
p16 INK4A p16 INK4A Non-tumor Sirius Red Non-tumor αSMA Non-tumor
p16 INK4A (-) patient 5 mm 5 mm Tumor 5 mm Tumor 5 mm Tumor Discussion

cancer accelerates neutrophil homing to the pre-metastatic liver showing no difference in
200 μm 200 μm 400 μm 400 μm p16 INK4A - p16 INK4A + In this study, we found that the presence of senescent tumor cells in the primary colorectal
F extracellular matrix modulation. In fact, neutrophils are regarded as a major component of
p16 INK4A p16 INK4A Sirius Red αSMA
Tumor Tumor Tumor the pre-metastatic niche. Especially, N2 subtype of neutrophils, marked by VEGF, MMP9,
and TNF-α, are known as a cancer promoting subset of neutrophil. Furthermore, pro-
p16 INK4A (+) patient 5 mm 5 mm Non-tumor 5 mm Non-tumor 5 mm Non-tumor serine proteases degrade thrombospondin-1 (Tsp-1) which has anti-tumorigenic effect against
metastatic neutrophils release various proteases, such as elastease and cathepsin G. These
metastatic seeding of circulating tumor cells. Further study is needed to elucidate how these
neutrophils were homed to pre-metastatic liver whether it is caused by chemoattractant-
receptor axis formation or increased differentiation of neutrophils in bone marrow.
200 μm 200 μm 400 μm 400 Considering increased mRNA expression level of CXCL12 in the senescent conditioned
medium injected mouse liver, CXCL12-CXCR4 axis could be a key candidate for this
μm
phenotypic difference until present. Moreover, the injection of cancer cells in the pre-learned
G H Control CM Senescent CM
liver will be performed to examine the metastatic potency of pre-learned liver made by
conditioned medium. Lastly, if there is a difference in cancer seeding ability in pre-learned
αSMA liver (control vs senescent), mechanism by which infiltrated neutrophils assist circulating
Intra-peritoneal injection Liver harvest cancer seeding in the pre-learned liver should be analyzed.
control or senescent SW480 CM & analysis
200 μm 200 μm
Female
Balb/c nude The main drawback of this study is a few number of p16 INK4A negative patient (n=6).
5wks old Incubation
Furthermore, pre-learned liver in patient can not be obtained because colorectal cancer
Sirius red bearing non-metastatic liver is not an indication for any surgical interventions. Instead, we
1 week 4 weeks
analyzed non-tumor lesion of the metastatic liver at least 5mm away from the invasive front
of the metastatic nodule to represent pre-metastatic liver in the patient samples.
200 μm 200 μm