Exosome-delivered microRNAs of "chromosome 19 microRNA cluster" as immunomodulators in pregnancy and tumorigenesis.
ABSTRACT Structural rearrangements of chromosomal band 19q13 are a non-random cytogenetic abnormality in thyroid adenomas and adenomatous goiters and lead to an expression of miRNAs of the chromosome 19 microRNA cluster C19MC. Normally, expression of these miRNAs is silenced except for embryonic stem cells and the placenta where they represent the majority of miRNAs not only in the trophoblast but also in exosomes derived from it.
We have advanced the hypothesis that as part of the feto-maternal communication miRNAs of C19MC serve immunomodulatory functions in the placenta and confer a growth advantage to thyroid nodules by protecting them against autoimmune attacks. More precisely, the exosomes containing these miRNAs may specifically target immune cells in their local environment as well as systemically by transferring their cargo to recipient cells. Within these target cells the transferred miRNAs can interact with mRNAs of the recipient cells thereby suppressing their immune-specific functions.
Experiments used to demonstrate the immunomodulatory capacity of placenta-derived exosomes can be modified by transfecting the target cells with those miRNAs of C19MC represented in placental exosomes.
Mimics of C19MC-derived miRNAs might develop to useful drug candidates for the treatment of autoimmune disease as e.g. rheumatoid arthritis and Sjögren's syndrome and for the prevention of transplant rejection. In case of tumor entities with elevated expression of C19MC miRNAs these miRNAs may be interesting targets for treatment with appropriate antagonists.
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ABSTRACT: Eight follicular adenomas of the thyroid gland were cytogenetically investigated. Of these, only one showed a chromosomal abnormality, a translocation t(10;19)(q22;p13 or q13). The situation is compared with that of thyroid carcinomas and pleomorphic adenomas.Cancer Genetics and Cytogenetics 06/1989; 39(1):65-8. · 1.93 Impact Factor
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ABSTRACT: Structural rearrangements involving the long arm of chromosome 19 characterize a cytogenetic subgroup of benign thyroid tumors and constitute one of the most frequent specific chromosome abnormalities in epithelial tumors. Recently, we have been able to narrow down the breakpoint region affected in two cell lines to a region covered by a single PAC clone. Close to that region a candidate gene has been identified which we tentatively referred to as RITA (Rearranged In Thyroid Adenomas) now named ZNF331 according to HUGO nomenclature. However, the results had been obtained on two cell lines only making it necessary to extend the studies to a larger number of tumors including primary material. Herein, we have used four further primary tumors showing translocations involving 19q13 for fluorescence in situ hybridization (FISH) mapping studies using a variety of molecular probes from a 470-kbp cosmid/BAC contig. Ten new STSs were characterized and physically mapped within an EcoRI restriction map. The results enabled us to define an approximately 150-kbp breakpoint cluster region of the 19q13 aberrations in benign thyroid tumors flanked by two newly established STS markers.Cytogenetics and cell genetics 02/2001; 93(1-2):48-51.
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ABSTRACT: Thyroid adenomas are common benign human tumors with a high prevalence of about 5% of the adult population even in iodine sufficient areas. Rearrangements of chromosomal band 19q13.4 represent a frequent clonal cytogenetic deviation in these tumors making them the most frequent non-random chromosomal translocations in human epithelial tumors at all. Two microRNA (miRNA) gene clusters i.e. C19MC and miR-371-3 are located in close proximity to the breakpoint region of these chromosomal rearrangements and have been checked for a possible up-regulation due to the genomic alteration. In 4/5 cell lines established from thyroid adenomas with 19q13.4 rearrangements and 5/5 primary adenomas with that type of rearrangement both the C19MC and miR-371-3 cluster were found to be significantly overexpressed compared to controls lacking that particular chromosome abnormality. In the remaining cell line qRT-PCR revealed overexpression of members of the miR-371-3 cluster only which might be due to a deletion accompanying the chromosomal rearrangement in that case. In depth molecular characterization of the breakpoint in a cell line from one adenoma of this type reveals the existence of large Pol-II mRNA fragments as the most likely source of up-regulation of the C19MC cluster. The up-regulation of the clusters is likely to be causally associated with the pathogenesis of the corresponding tumors. Of note, the expression of miRNAs miR-520c and miR-373 is known to characterize stem cells and in terms of molecular oncology has been implicated in invasive growth of epithelial cells in vitro and in vivo thus allowing to delineate a distinct molecular subtype of thyroid adenomas. Besides thyroid adenomas rearrangements of 19q13.4 are frequently found in other human neoplasias as well, suggesting that activation of both clusters might be a more general phenomenon in human neoplasias.PLoS ONE 01/2010; 5(3):e9485. · 3.73 Impact Factor
Exosome-delivered microRNAs of “chromosome
19 microRNA cluster” as immunomodulators in
pregnancy and tumorigenesis
Jörn Bullerdiek*and Inga Flor
Background: Structural rearrangements of chromosomal band 19q13 are a non-random cytogenetic abnormality in
thyroid adenomas and adenomatous goiters and lead to an expression of miRNAs of the chromosome 19 microRNA
cluster C19MC. Normally, expression of these miRNAs is silenced except for embryonic stem cells and the placenta
where they represent the majority of miRNAs not only in the trophoblast but also in exosomes derived from it.
Presentation of the hypothesis: We have advanced the hypothesis that as part of the feto-maternal communication
miRNAs of C19MC serve immunomodulatory functions in the placenta and confer a growth advantage to thyroid
nodules by protecting them against autoimmune attacks. More precisely, the exosomes containing these miRNAs may
specifically target immune cells in their local environment as well as systemically by transferring their cargo to recipient
cells. Within these target cells the transferred miRNAs can interact with mRNAs of the recipient cells thereby
suppressing their immune-specific functions.
Testing the hypothesis: Experiments used to demonstrate the immunomodulatory capacity of placenta-derived
exosomes can be modified by transfecting the target cells with those miRNAs of C19MC represented in placental
Implications of the hypothesis: Mimics of C19MC-derived miRNAs might develop to useful drug candidates for the
treatment of autoimmune disease as e.g. rheumatoid arthritis and Sjögren’s syndrome and for the prevention of
transplant rejection. In case of tumor entities with elevated expression of C19MC miRNAs these miRNAs may be
interesting targets for treatment with appropriate antagonists.
Keywords: MicroRNA, Chromosomal translocation, Thyroid adenoma, C19MC, Placenta, Epigenetics,
First being described in 1989 , structural rearrange-
ments of chromosomal band 19q13 are a frequent non-
random cytogenetic abnormality in thyroid adenomas and
adenomatous goiters. By applying molecular-cytogenetic
methods on established cell lines it was possible to narrow
down the breakpoints to a region of about 150 kbp 
which was later shown to harbor C19MC (chromosome
19 microRNA cluster), the largest human microRNA clus-
ter at all  (Figure 1). As a rule, by the chromosomal
rearrangements the microRNAs of this cluster and the
neighboring miR-371-3 cluster become strongly upregu-
lated . Of these both clusters C19MC is remarkable not
only because of its sheer size encoding more than 50 ma-
ture microRNAs but also because of its “young” age. The
whole cluster is primate-specific  and thus must have
evolved within a relatively short time in terms of evolution.
Normally, the miRNAs of C19MC are expressed almost
exclusively in embryonic stem cells [5-9] and, later during
embryonic and fetal development, only in the placenta
[3,10]. Luo et al.  demonstrated that the trophoblast
secretes exosomes, i.e. small membrane microvesicles,
which contain placenta-specific miRNAs. Moreover, it was
demonstrated quite recently that the vast majority of miR-
NAs packed into placenta-derived exosomes consist of
* Correspondence: email@example.com
Center for Human Genetics, University of Bremen, Leobener Str. ZHG, Bremen
© 2012 Bullerdiek and Flor; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the
Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Bullerdiek and Flor Molecular Cytogenetics 2012, 5:27
miRNAs of the C19MC cluster . However, in both
cases, i.e. in the placenta or after chromosomal transloca-
tions in benign thyroid nodules, the exact mechanisms by
which C19MC miRNAs contribute to normal or aberrant
functions, respectively, remain obscure.
Herein, we shall advance the hypothesis that as part of
the feto-maternal communication miRNAs of C19MC
serve immunomodulatory functions in the placenta and,
once re-expressed due to chromosomal translocations,
confer a growth advantage to thyroid nodules by protect-
ing them against autoimmune attacks.
Presentation of the hypothesis
Though cytogenetic aberrations of 19q13.4 as detected in
benign thyroid lesions represent one of the most common
specific chromosomal alterations in epithelial tumors at all
the molecular mechanisms resulting from these frequent
genomic alterations still remain obscure. As to tumorigen-
esis, the stimulation of invasive growth has been attributed
to some miRNAs of C19MC [for review see 13] but
the activation of the cluster in thyroid adenomas and
nodular goiters with 19q13.4 alterations apparently does
not coincide with invasive growth. Thus, it seems un-
likely that in general activation of C19MC leads to inva-
sive growth or other features characterizing malignant
cells. On the other hand, presumed “physiological func-
tions” of its miRNAs might give us a clue to understand
their role in tumorigenesis. Of note, until birth expres-
sion of C19MC persists only in the placenta or, more
precisely, its trophoblast [10,11], and is expressed exclu-
sively from the paternal allele whereas the maternal al-
lele is silenced by epigenetic modification .
In general, miRNAs do not necessarily exert their main
functions in the cells they are expressed in since consider-
able amounts of miRNAs can become packed into micro-
vesicles called exosomes. Exosomes are bioactive vesicles
derived from endosomal membranes and involved in
intercellular communication by their specific cargos of
proteins, mRNAs, and miRNAs [for review see 15]. In
previous reports placenta-derived exosomes have been
demonstrated to interact with immune cells, e.g. resulting
in suppression of T-cell signaling components [16,17].
Figure 1 (A) Partial karyotype of an adenoma with an apparently balanced translocation t(1;19)(q32;q13.4) is shown as an example of
adenomas with a 19q13.4 chromosomal rearrangement. (B) Metaphase of a thyroid adenoma with a t(1;19)(q32;q13.4) after FISH with dual-color
break-apart rearrangement probe appropriate for the detection of 19q13.4 rearrangements. The 19q13.4 rearrangement is indicated by one single
green and one single red signal each. (C) The chromosomal region 19q13.4 with the miRNA clusters C19MC and miR-371-3 (pink boxes) and
surrounding protein-coding genes (blue boxes). The common breakpoint cluster of thyroid adenomas and adenomatous goiters is indicated by an
Bullerdiek and Flor Molecular Cytogenetics 2012, 5:27
Page 2 of 4
Donker et al.  were able to demonstrate recently
that the cellular miRNA composition of human primary
trophoblast cells strongly resembled that of the exosomes
secreted from these cells. In both cases those of C19MC
represented the majority of mature miRNAs. Of note, six
microRNAs of C19MC ranged among the top-ten exoso-
mal miRNAs. Based on their findings the authors have
assumed that these miRNAs “may play an important role
in placental-maternal communication, possibly directing
maternal adaptation to pregnancy.”
Herein, we would like to outline the hypothesis that
as one major function miRNAs of C19MC prevent the
embryo from being attacked by the maternal immune
system. Immunologically, the embryo is considered being
a semi-allograft and in case of egg donation even a full
allograft . Nevertheless, the embryo efficiently avoids
rejection by its mother’s immune system by mechanisms
that are not fully understood yet [for review see 19]. Exo-
somes are known to share membrane characteristics with
the cells they are derived from . Thus, it seems tempt-
ing to assume that they act like decoy-flairs for a jet. The
exosomes can specifically target immune cells in their
local environment, i.e. the decidua, as well as systemically
thereby transferring their cargo when melting with the
membrane of recipient cells. Within these target cells the
transferred miRNAs can interact with mRNAs of the
recipient cells thereby modulating post-transcriptional
regulation. Non-specific systemic side effects of this mech-
anism may be the mild immunosuppression noted during
pregnancy e.g. leading to the improvement of rheumatoid
arthritis [for review see 21].
Tracing back to nodular goiters and thyroid adenomas
re-expression of C19MC may protect cells against auto-
immune attacks. Of note, a considerable percentage of
these lesions develop after a pre-existing autoimmune dis-
ease of the thyroid.
Finally, the question arises if malignant tumors can
adopt this mechanism to protect themselves. 19q13 is one
of the most frequent chromosomal breakpoints identified
in human tumors and even if, in particular in case of com-
plex karyotypic aberrations, the small size of chromosome
19 may have resulted in false positive identification of this
breakpoint there remain a number of tumor entities where
its involvement has been identified unambiguously as e.g.
hamartoma of the liver [22,23]. Also, a number of recent
papers point to the role of amplification (e. g. in CNS-
PNET  and in embryonal brain tumors with ependy-
moblastic multilayered rosettes ) or undermethylation
of the C19MC locus (e. g. in hepatocellular carcinomas
[26,27]) in several tumor entities.
Testing the hypothesis
There are straightforward appropriate experimental
approaches to test our hypothesis. Nevertheless, these
approaches are time consuming because not all miRNAs
of the cluster may have the capacity to modulate immune
cells and because different types of immune cells have to
be tested. As a first step the same experiments used to
demonstrate the immunomodulatory capacity of placenta-
derived exosomes [e.g. 17] can be modified by transfecting
the target cells with those miRNAs of C19MC highly
represented in placental exosomes. Furthermore, it did
not escape our attention that mesenchymal cells from
the amniotic membrane have strong immunomodula-
tory properties, e.g. by actively suppressing T-cell prolif-
eration induced by alloantigens . So far, it is believed
that at term only the trophoblast expresses C19MC
miRNAs but if our hypothesis holds true one would ex-
pect that these amniotic-membrane derived cells do so
Implications of the hypothesis
If the hypothesis holds true it will be not only relevant
in terms of basic science but also for several clinical
approaches. Mimics of C19MC-derived miRNAs, either
encapsulated or not, might develop to useful drug candi-
dates for the treatment of autoimmune disease as e.g.
rheumatoid arthritis and Sjögren’s syndrome. Likewise,
these miRNAs may prolong the maintenance of func-
tional allografts. On the other hand, in case of tumor en-
tities with forced expression of C19MC miRNAs their
antagonists may represent interesting alternatives for
C19MC: chromosome 19 microRNA cluster; CNS-PNET: Central nervous
system primitive neuroectodermal tumor; miRNA: microRNA.
The authors declare competing financial interests because the University of
Bremen is currently applying for a patent claiming the use of C19MC miRNAs
Both authors have equally contributed to this hypothesis and written the
manuscript. Both authors read and approved the final manuscript.
Received: 5 April 2012 Accepted: 6 May 2012
Published: 6 May 2012
1.Bartnitzke S, Herrmann ME, Lobeck H, Zuschneid W, Neuhaus P, Bullerdiek J:
Cytogenetic findings on eight follicular thyroid adenomas including one
with a t(10;19). Canc Genet Cytogenet 1989, 39:65–68.
2. Belge G, Rippe V, Meiboom M, Drieschner N, Garcia E, Bullerdiek J:
Delineation of a 150-kb breakpoint cluster in benign thyroid tumors with
19q13.4 aberrations. Cytogenet Cell Genet 2001, 93:48–51.
3. Bentwich I, Avniel A, Karov Y, Aharonov R, Gilad S, Barad O, Barzilai A, Einat
P, Einav U, Meiri E, et al: Identification of hundreds of conserved and
nonconserved human microRNAs. Nat Genet 2005, 37:766–770.
4.Rippe V, Dittberner L, Lorenz VN, Drieschner N, Nimzyk R, Sendt W, Junker K,
Belge G, Bullerdiek J: The two stem cell microRNA gene clusters C19MC
and miR-371-3 are activated by specific chromosomal rearrangements in
a subgroup of thyroid adenomas. PLoS One 2010, 5:e9485.
5.Bar M, Wyman SK, Fritz BR, Qi J, Garg KS, Parkin RK, Kroh EM, Bendoraite A,
Mitchell PS, Nelson AM, et al: MicroRNA discovery and profiling in human
Bullerdiek and Flor Molecular Cytogenetics 2012, 5:27
Page 3 of 4
embryonic stem cells by deep sequencing of small RNA libraries. Stem
Cell 2008, 26:2496–2505.
Laurent LC, Chen J, Ulitsky I, Mueller FJ, Lu C, Shamir R, Fan JB, Loring JF:
Comprehensive microRNA profiling reveals a unique human embryonic
stem cell signature dominated by a single seed sequence. Stem Cell 2008,
Morin RD, O'Connor MD, Griffith M, Kuchenbauer F, Delaney A, Prabhu AL,
Zhao Y, McDonald H, Zeng T, Hirst M, et al: Application of massively
parallel sequencing to microRNA profiling and discovery in human
embryonic stem cells. Genome Res 2008, 18:610–621.
Ren J, Jin P, Wang E, Marincola FM, Stroncek DF: MicroRNA and gene
expression patterns in the differentiation of human embryonic stem
cells. J Transl Med 2009, 7:20.
Cao H, Yang CS, Rana TM: Evolutionary emergence of microRNAs in
human embryonic stem cells. PLoS One 2008, 3:e2820.
Zhang R, Wang YQ, Su B: Molecular evolution of a primate-specific
microRNA family. Mol Biol Evol 2008, 25:1493–1502.
Luo SS, Ishibashi O, Ishikawa G, Ishikawa T, Katayama A, Mishima T, Takizawa
T, Shigihara T, Goto T, Izumi A, et al: Human villous trophoblasts express
and secrete placenta-specific microRNAs into maternal circulation via
exosomes. Biol Reprod 2009, 81:717–729.
Donker RB, Mouillet JF, Chu T, Hubel CA, Stolz DB, Morelli AE, Sadovsky Y:
The expression profile of C19MC microRNAs in primary human
trophoblast cells and exosomes. Mol Human Reprod 2012. doi:10.1093/
molehr/gas013. “Accepted Article”.
Flor I, Bullerdiek J: The dark side of a success story: microRNAs of the
C19MC cluster in human tumours. J Pathol 2012. doi:10.1002/path.4014.
Noguer-Dance M, Abu-Amero S, Al-Khtib M, Lefevre A, Coullin P, Moore GE,
Cavaille J: The primate-specific microRNA gene cluster (C19MC) is
imprinted in the placenta. Hum Mol Genet 2010, 19:3566–3582.
Pant S, Hilton H, Burczynski ME: The multifaceted exosome: Biogenesis,
role in normal and aberrant cellular function, and frontiers for
pharmacological and biomarker opportunities. Biochem Pharmacol 2012,
Taylor DD, Akyol S, Gercel-Taylor C: Pregnancy-associated exosomes and
their modulation of T cell signaling. J Immunol 2006, 176:1534–1542.
Sabapatha A, Gercel-Taylor C, Taylor DD: Specific isolation of placenta-
derived exosomes from the circulation of pregnant women and their
immunoregulatory consequences. Am J Reprod Immunol 2006, 56:345–355.
van der Hoorn ML, Scherjon SA, Claas FH: Egg donation pregnancy as an
immunological model for solid organ transplantation. Transplant Immunol
Warning JC, McCracken SA, Morris JM: A balancing act: mechanisms by
which the fetus avoids rejection by the maternal immune system.
Reproduction 2011, 141:715–724.
Mincheva-Nilsson L, Baranov V: The role of placental exosomes in
reproduction. Am J Reprod Immunol 2010, 63:520–533.
Ostensen M, Villiger PM, Forger F: Interaction of pregnancy and
autoimmune rheumatic disease. Autoimmun Rev 2012, 11:A437–A446.
Speleman F, De Telder V, De Potter KR, Dal Cin P, Van Daele S, Benoit Y,
Leroy JG, Van den Berghe H: Cytogenetic analysis of a mesenchymal
hamartoma of the liver. Canc Genet Cytogenet 1989, 40:29–32.
Rajaram V, Knezevich S, Bove KE, Perry A, Pfeifer JD: DNA sequence of the
translocation breakpoints in undifferentiated embryonal sarcoma arising
in mesenchymal hamartoma of the liver harboring the t(11;19)(q11;
q13.4) translocation. Genes Chromosomes Canc 2007, 46:508–513.
Li M, Lee KF, Lu Y, Clarke I, Shih D, Eberhart C, Collins VP, Van Meter T,
Picard D, Zhou L, et al: Frequent amplification of a chr19q13.41 microRNA
polycistron in aggressive primitive neuroectodermal brain tumors. Canc
Cell 2009, 16:533–546.
Nobusawa S, Yokoo H, Hirato J, Kakita A, Takahashi H, Sugino T, Tasaki K,
Itoh H, Hatori T, Shimoyama Y, et al: Analysis of Chromosome 19q13.42
Amplification in Embryonal Brain Tumors with Ependymoblastic
Multilayered Rosettes. Brain Pathol 2012. doi:10.1111/j.1750-
3639.2012.00574.x. “Accepted Article”.
Fornari F, Milazzo M, Chieco P, Negrini M, Marasco E, Capranico G,
Mantovani V, Marinello J, Sabbioni S, Callegari E, et al: In hepatocellular
carcinoma miR-519d is upregulated by p53 and DNA hypomethylation
and targets CDKN1A/p21, PTEN, AKT3 and TIMP2. J Pathol 2012.
doi:10.1002/path.3995. "Accepted Article".
27.Augello C, Vaira V, Caruso L, Destro A, Maggioni M, Park YN, Montorsi M,
Santambrogio R, Roncalli M, Bosari S: MicroRNA profiling of
hepatocarcinogenesis identifies C19MC cluster as a novel prognostic
biomarker in hepatocellular carcinoma. Liver Int 2012, 32:772–782.
Wolbank S, Peterbauer A, Fahrner M, Hennerbichler S, van Griensven M, Stadler
G, Redl H, Gabriel C: Dose-dependent immunomodulatory effect of human
stem cells from amniotic membrane: a comparison with human
mesenchymal stem cells from adipose tissue. Tissue Eng 2007, 13:1173–1183.
Cite this article as: Bullerdiek and Flor: Exosome-delivered microRNAs of
“chromosome 19 microRNA cluster” as immunomodulators in
pregnancy and tumorigenesis. Molecular Cytogenetics 2012 5:27.
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