An immortalized implantation site intermediate trophoblastic cell line, IST-1, was established from a human placenta of 7 weeks gestation. IST-1 cells phenotypically resembled the implantation site intermediate trophoblastic cells in situ and expressed Mel-CAM (MUC 18 or CD146). Mel-CAM is a cell adhesion molecule belonging to the immunoglobulin gene superfamily. It is involved in heterophilic cell-cell adhesion and plays a role in several biological processes including tumor progression. We have previously shown that Mel-CAM was highly expressed in the intermediate (extravillous) trophoblast in the human implantation site. In this study we determined the function of Mel-CAM in the interaction of trophoblast and uterine smooth muscle in the implantation site. IST-1 cells failed to adhere to immobilized recombinant Mel-CAM in solid phase whereas the uterine smooth muscle cells did. The presence of the putative Mel-CAM ligand in smooth muscle cells was further supported by the finding that Mel-CAM-transfected but not the mock-transfected U937 leukemia cells bind to the confluent monolayer of uterine smooth muscle cells. IST-1 cells attached efficiently to the monolayer of the uterine smooth muscle cells and acquired a spindle-shaped morphology simulating smooth muscle cells. The cell binding was only marginally affected by Mel-CAM blocking antibodies. However, Mel-CAM blocking antibodies and recombinant Mel-CAM promoted cell migration from IST-1 cell spheroids on the smooth muscle monolayer. Taken together, our results suggest that IST-1 cells express Mel-CAM but not the putative Mel-CAM ligand. In contrast, the uterine smooth muscle cells express the putative Mel-CAM ligand which binds to Mel-CAM on the surface of the IST-1 cells. The interaction between Mel-CAM and its putative ligand confers a stationary phenotype for trophoblastic cells. These observations are consistent with an important role for Mel-CAM in limiting trophoblastic migration within the myometrium in the implantation site.

REFERENCES

Autio-Harmainen
H.
,
Hurskainen
T.
,
Niskasaari
K.
,
Hoyhyya
M.
,
Tryffvason
K.
(
1992
).
Simultaneous expression of 70 kilodalton type IV collagenase and type IV collagen 1(IV) chain genes by cells of early human placenta and gestational endometrium.
Lab. Invest
67
,
191
200
Babury
R. A.
,
Moscovic
E. A.
(
1993
).
Selective immunolabeling of early gestational cytotrophoblast and its neoplastic counterpart by the monoclonal antibody Ber-EP4.
Histo. Histopath
8
,
323
328
Behrens
J.
,
von Kries
J. P.
,
Kuhl
M.
,
Bruhn
L.
,
Wedlich
D.
,
Grosscheldl
R.
,
Birchmeier
W.
(
1996
).
Functional interaction of-catenin with the transcription factor LEF-1.
Nature
382
,
638
642
Burrows
T. D.
,
King
A.
,
Loke
Y. W.
(
1993
).
Expression of integrins by human trophoblast and differential adhesion to laminin or fibronectin.
Human Reproduct
8
,
475
484
Burrows
T. D.
,
King
A.
,
Loke
Y. W.
(
1994
).
Expression of adhesion molecules by endovascular trophoblast and decidual endothelial cells: implications for vascular invasion during implantation.
Placenta
15
,
21
33
Carnemolla
B.
,
Balza
E.
,
Siri
A.
,
Zardi
L.
,
Nicotra
M. R.
,
Bigotti
A.
,
Natali
P. G.
(
1989
).
A tumor-associated fibronectin isoform generated by alternative splicing of messenger RNA precursors.
J. Cell Biol
108
,
1139
1148
Cary
L. A.
,
Han
D. C.
,
Polte
T. R.
,
Hanks
S. K.
,
Guan
J.-L.
(
1998
).
Identification of p130Casas a mediator of focal adhesion kinase-promoted cell migration.
J. Cell Biol
140
,
211
221
Chomczynski
P.
,
Sacchi
N.
(
1985
).
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
Anal. Biochem
162
,
156
159
Cross
J. C.
,
Werb
Z.
,
Fisher
S. J.
(
1994
).
Implantation and the placenta: key pieces of the development puzzle.
Science
266
,
1508
1518
Damsky
C. H.
,
Fitzgerald
M. L.
,
Fisher
S. J.
(
1992
).
Distribution patterns of extracellular matrix components and adhesion receptors are intricately modulated during first trimester cytotrophoblast differentiation along the invasive pathway, in vivo.
J. Clin. Invest
89
,
210
222
Damsky
C. H.
,
Librach
C.
,
Lim
K.-H.
,
Fitzgerald
M. L.
,
McMaster
M. T.
,
Janatpour
M.
,
Zhou
Y.
,
Logan
S. K.
,
Fisher
S. J.
(
1994
).
Integrin switching regulates normal trophoblast invasion.
Development
120
,
3657
3666
Fisher
S. J.
,
Damsky
C. H.
(
1993
).
Human cytotrophoblast invasion.
Semin. Cell Biol
4
,
183
188
Friedlander
D. R.
,
Zagzag
D.
,
Shiff
B.
,
Cohen
H.
,
Allen
J. C.
,
Kelly
P. J.
,
Grumet
M.
(
1996
).
Migration of brain tumor cells on extracellular matrix proteins in vitro correlates with tumor type and grade and involvesV 1 integrins.
Cancer Res
56
,
1939
1947
Ginsberg
M. H.
,
Du
X.
,
Plow
E. F.
(
1992
).
Inside-out integrin signaling.
Curr. Opin. Cell Biol
4
,
766
771
Graham
C. H.
,
Hawley
T. S.
,
Hawley
R. G.
,
MacDougall
J. R.
,
Kervel
R. S.
,
Khoo
N.
,
Lala
P. K.
(
1993
).
Establishment and characterization of first trimester human trophoblast cells with extended lifespan.
Exp. Cell Res
206
,
204
211
Halbert
C. L.
,
Demers
G. W.
,
Galloway
D. A.
(
1991
).
The E7 gene of human papillomavirus type 16 is sufficient form immortalization of human epithelial cells.
J. Virol
65
,
473
478
Huttenlocher
A.
,
Sandborg
R. R.
,
Horwitz
A. F.
(
1995
).
Adhesion in cell migration.
Curr. Opin. Cell Biol
7
,
697
706
Huttenlocher
A.
,
Lakonishok
M.
,
Kinder
M.
,
Wu
S.
,
Truong
T.
,
Knudsen
D. A.
,
Horwitz
A. F.
(
1998
).
Integrin and cadherin synergy regulates contact inhibition of migration and motile activity.
J. Cell Biol
141
,
515
526
Hurskainen
T.
,
Seiki
M.
,
Apte
S. S.
,
Syrjakallio
Y.
,
Sorsa
T.
,
Iokarinen
A.
,
Autio-Harmainen
H.
(
1998
).
Production of membrane-type matrix metalloproteinase-1 (MT-MMP-1) in early human placenta: a possible role in placental implantation?.
J. Histochem. Cytochem
46
,
221
229
Hynes
R. O.
(
1992
).
Integrins: versatility, modulation, and signaling in cell adhesion.
Cell
69
,
11
25
Irving
J. A.
,
Lala
P. K.
(
1995
).
Functional role of cell surface integrins on human trophoblast cell migration: regulation by TGF-, IGF-II, and IGFBP-1.
Exp. Cell Res
217
,
419
427
Irving
J. A.
,
Lysiak
J. J.
,
Graham
C. H.
,
Hearn
S.
,
Han
V. K. M.
,
Lala
P. K.
(
1995
).
Characteristics of trophoblast cells migrating from first trimester chorionic villus explants and propagated in culture.
Placenta
16
,
413
433
Kobayashi
Y.
,
Nikaido
T.
,
Zhai
Y. L.
,
Iinuma
M.
,
Shiozawa
T.
,
Shirota
M.
,
Fujii
S.
(
1996
).
In-vitro model of uterine leiomyomas: formation of ball-like aggregates.
Human Reproduct
11
,
1724
1730
Kurman
R. J.
,
Main
C. S.
,
Chen
H. C.
(
1984
).
Intermediate trophoblast: a distinctive form of trophoblast with specific morphological, biochemical and functional features.
Placenta
5
,
349
370
Kurman
R. J.
(
1991
).
The morphology, biology, and pathology ofintermediate trophoblast—a look back to the present.
Hum. Pathol
22
,
847
855
Lala
P. K.
,
Hamilton
G. S.
(
1996
).
Growth factors, proteases and protease inhibitors in the maternal-fetal dialogue.
Placenta
17
,
545
555
Lehmann
J. M.
,
Riethmuller
G.
,
Johnson
J. P.
(
1989
).
Muc18, a marker of tumor progression in human melanoma, shows sequence similarity to the neural cell adhesion molecules of the immunoglobulin superfamily.
Proc. Nat. Acad. Sci. USA
86
,
9891
9895
McMaster
M. T.
,
Librach
C. L.
,
Zhou
Y.
,
Lim
K. H.
,
Janatporu
M. J.
,
DeMars
R.
,
Kovats
S.
,
Damsky
C.
,
Fisher
S. J.
(
1995
).
Human placental HLA-G expression is restricted to differentiated cytotrophoblasts.
J. Immunol
154
,
3771
3778
Muhlhauser
J.
,
Crescimanno
C.
,
Kaufmann
P.
,
Hofler
H.
,
Zaccheo
D.
,
Castellucci
M.
(
1993
).
Differentiation and proliferation patterns in human trophoblast revealed by c-erbB2 oncogene product and EGF-R.
J. Histochem. Cytochem
41
,
165
173
Ober
C.
,
Aldrich
C.
,
Rosinsky
B.
,
Robertson
A.
,
Walker
M. A.
,
Willadsen
S.
,
Verp
M. S.
,
Geraghty
D. E.
,
Hunt
J. S.
(
1998
).
HLA-G protein expression is not essential for fetal survival.
Placenta
19
,
127
132
Qin
X.
,
Garibay-Tupas
J.
,
Chua
P. K.
,
Cachola
L.
,
Bryant-Greenwood
G. D. B.
(
1997
).
An autocrine/paracrine role of human decidual relaxin 1 interstitial collagenase (matrix metalloproteinase-1) and tissue plasminogen activator.
Biol. Reprod
56
,
800
811
Saiki
R. K.
,
Scharf
S.
,
Faloona
F.
,
Mullis
K. B.
,
Horn
G. T.
,
Ehrlich
H.
,
Arnheim
N.
(
1985
).
Enzymatic amplification of beta-globin genomic sequences and restriction site analysis for diagnosis of sickle cell anemia.
Science
230
,
1350
1354
Sers
C.
,
Kirsch
K.
,
Rothbächer
U.
,
Riethmuller
G.
,
Johnson
J. P.
(
1993
).
The gene encoding the melanoma-associated glycoprotein MUC18 displays a unique structure among the members of the immunoglobulin superfamily.
Proc. Nat. Acad. Sci. USA
90
,
8514
8518
Shih
I.-M.
,
Elder
D. E.
,
Speicher
D.
,
Johnson
J. P.
,
Herlyn
M.
(
1994
).
Isolation and functional characterization of the A32 melanoma-associated antigens.
Cancer Res
54
,
2514
2520
Shih
I.-M.
,
Kurman
R. J.
(
1996
).
Expression of melanoma cell adhesion molecule in intermediate trophoblast.
Lab. Invest
75
,
377
388
Shih
I.-M.
,
Speicher
D.
,
Hsu
M.-Y.
,
Levine
E.
,
Herlyn
M.
(
1997
).
Melanoma cell-cell interactions are mediated through heterophilic Mel-CAM/ligand adhesion.
Cancer Res
57
,
3835
3840
Shih
I.-M.
,
Hsu
M.-Y.
,
Palazzo
J. P.
,
Herlyn
M.
(
1997
).
The cell-cell adhesion receptor Mel-CAM acts as a tumor suppressor in breast carcinoma.
Am. J. Pathol
151
,
745
751
Shih
I.-M.
,
Schnarr
R. L.
,
Gearhart
J. D.
,
Kurman
R. J.
(
1997
).
Distribution of cells bearing the HNK-1 epitope in the human placenta.
Placenta
18
,
667
674
Shiokawa
S.
,
Yoshimura
Y.
,
Nagamatsu
S.
,
Sawa
H.
,
Hanashi
H.
,
Koyama
N.
,
Datsumata
Y.
,
Nagai
A.
,
Nakamura
Y.
(
1996
).
Function of1 integrins on human decidual cells during implantation.
Biol. Reprod
54
,
745
752
Weaver
V. M.
,
Petersen
O. W.
,
Wang
F.
,
Larabell
C. A.
,
Briand
P.
,
Damsky
C.
,
Bissell
M. J.
(
1997
).
Reversion of the malignant phenotype of human breast cells in three-dimensional culture and in vivo by integrin blocking antibodies.
J. Cell Biol
137
,
231
245
Xie
S.
,
Luca
M.
,
Huang
S.
,
Gutman
M.
,
Reich
R.
,
Johnson
J. P.
,
Bar-Eli
M.
(
1997
).
Expression of MCAM/MUC18 by human melanoma cells leads to increased tumor growth and metastasis.
Cancer Res
57
,
2295
2303
Yagel
S.
,
Parhar
R. S.
,
Jeffrey
J. J.
,
Lala
P. K.
(
1988
).
Normal nonmetastatic human trophoblast cells share in vitro invasive properties of malignant cells.
J. Cell. Physiol
136
,
455
462
Yagel
S.
,
Casper
R. F.
,
Powell
W.
,
Parhar
R. S.
,
Lala
P. K.
(
1989
).
Characterization of pure human first-trimester cytotrophoblast cells in long-term culture: growth pattern, markers, and hormone production.
Am. J. Obst. Gynecol
160
,
938
945
Yamada
D. M.
,
Miyamoto
S.
(
1995
).
Integrin transmembrane signaling and cytoskeletal control.
Curr. Opin. Cell Biol
7
,
681
689
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