metastasis-initiating cells in a CD36-dependent manner. The use of neutralizing antibodies to block
CD36 causes almost complete inhibition of metastasis in immunodeficient or immunocompetent orthotopic mouse models
of human oral cancer, with no side effects. Clinically, the presence of CD36
metastasis-initiating cells correlates with
a poor prognosis for numerous types of carcinomas, and inhibition of CD36 also impairs metastasis, at least in human
melanoma- and breast cancer-derived tumours. Together, our results indicate that metastasis-initiating cells particularly
rely on dietary lipids to promote metastasis.
Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), 08028 Barcelona, Spain.
the parental cells (Extended Data Figs 3b–d, 4a). By contrast, primary
tumour growth was only slightly, if at all, enhanced by CD36 over-
expression (less than twofold) (Extended Data Figs 3b, 4a). Most
importantly, short hairpin RNA (shRNA)-mediated depletion of CD36
significantly reduced the penetrance of metastasis to lymph nodes, in
some cases by 80–100%. Either no or, in one tumour case, only slight
effects on oral lesion growth were observed (Fig. 2a, b and Extended
Data Fig. 4b). Conversely, CD36 depletion greatly reduced the size
of lymph node metastases in all tumour lines, and inhibited lung
metastasis by FaDu cells (Extended Data Fig. 4b-f).
CD36
cells respond to dietary lipids
The histological analyses of the few lymph node metastases that
grew from CD36-depleted cells presented an intriguing pattern
of large swollen cells that were filled with lipid droplets containing
non- metabolized lipids (Fig. 2c, d and Extended Data Fig. 4g). These
structures were not present in the oral lesions generated by OSCC cells
depleted of CD36 (Extended Data Fig. 4h). We therefore hypothesized
that CD36
+
cells might specifically require lipid metabolism to exert
their metastatic potential. In fact, CD36
+
CD44
bright
cells isolated from
primary oral orthotopic tumours, but not their CD36
CD44counterprts, expressed numerous genes involved in lymphatic
metastasis and lipid metabolism, which overlapped with the dye
comparison versus top 300 genes of primary tumour sorted by fold change
(FC). Nominal P < 0.0001. All source data from mouse experiments are in
Supplementary Information.
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
ArticlereSeArcH
Extended Data Figure 9 | Anti-CD36 neutralizing antibodies inhibit
metastatic initiation, and cause metastatic regression of oral SCC.
a, BLI quantification of tumours from mice treated with anti-CD36
FA6.152 (anti-CD36 FA6.152, n = 3 mice; IgG1, n = 3 mice; * * P = 0.004,
two-tailed t-test). b, d, BLI monitoring of tumours from mice treated
daily with anti-CD36 JC63.1 (anti-CD36: n = 5 mice; anti-IgA isotype
control, n = 5 mice). Graphs show the BLI signal quantification (* P = 0.04,
two-tailed t-test). c, Representative pictures of metastatic lymph nodes
of animals treated daily with JC63.1 or IgA for 2.5 weeks. e, Activated
caspase-3 immunostaining of metastatic lymph nodes of Detroit-562
transplants from mice treated with monoclonal anti-CD36 JC63.1
(10 μ g per 100 μ l), or with the IgA isotype control. f, BLI monitoring of
immunocompetent C3H/HeJ mice treated daily with monoclonal JC63.1
or IgA. Graphs show BLI signals from tumours (* P = 0.05, two-tailed
t-test). g, Fold change in metastasis BLI signal of the animals reported
in d. h, Representative haematoxylin and eosin staining of liver, spleen,
thymus and kidney of mice from f. No pathological differences related to
anti-CD36 treatment were found (n = 10 animals per group). Data in
a, d, f, g are given as the mean ± s.e.m.
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Article reSeArcH
Extended Data Figure 10 | Expression of CD36 correlates with poor
prognosis in several human tumours, and inhibition of CD36 inhibits
metastasis of human melanoma and luminal A breast carcinoma cell
lines. a, Correlation of CD36-associated signature expression or CD36
expression with overall and disease-free survival for patients. Red and
green lines denote patients whose tumours expressed signatures or CD36
higher and lower than the median, respectively. b, BLI signals from
metastasis developed in NSG mice injected with MCF-7 (PLKO, n = 10;
Cd36 shRNA, n = 10 mice) and 501mel (PLKO, n = 10; Cd36 shRNA,
n = 10 mice) cells (for breast MCF-7, * P = 0.04, two-tailed t-test and for
melanoma 501mel, * * * P = 0.0001 in liver metastasis and * * P = 0.0003
in lung metastasis, two-tailed t-test). c, Relative proportion of developed
metastases from mice in a (* P = 0.05, two-tailed Fisher’s exact test). d, BLI
signals from primary tumours and relative blood and lung GFP RNA levels
measured by qPCR analysis after intravenous injection of Detroit-562 and
SCC-25 cells transduced with empty vector (control) or shRNA Cd36.
Samples were collected immediately after injection (T-0h) and 12 and
48 h (T-12h and T-48h, respectively) after injection (n = 3 animals per
time point in each of the groups; * P ≤ 0.05, two-tailed t-test). Data in b,
d, are given as the mean ± s.e.m. e, GSEA of EMT genes in CD36