Cancer Genetics and Epigenetics 2015, Vol.3, No.12, 1-7
3
Figure 1 The result of clustering is on the top of the picture.
The blue stands for low expression level, and the red stands for
high expression level.
neuroactive ligand-receptor interaction pathway, which is
a collection of neuroactive receptors in the plasma
membranes, is involved in the stability of the
neuroendocrine system. This shows that neuroactive
ligand-receptor interaction pathway may be associated
with the development of prolactinoma (Figure 3).
2.4 The construction of PPI network
In order to analyze the function of DEGs, we input
them into PPI network and construct a sub-PPI network.
Then we use Cytoscape
/) for
the visualization of sub-PPI network. The network
includes 1151 nodes and 1131 edges, and there are 70
DEGs which exists in sub-PPI network (Figure 4). In
order to analyze the relationship of genes, we use
MCODE to extract significant modules. We identify
16 motifs and choose the most significant one to
analyze the functions. The motif includes 5 genes such
as GAL, GALR1, GALR2, GALR3 and GPR151
(Yang et al., 2014).
Hub gene always play an important role in network,
and we regard genes with degree more than 80 as hub
genes, including MDM2, LYN, CDH1, GH1, ACTG1
and FUS. We find these genes are all DEGs, which
proves the important role of DEGs in network.
Moreover, we input DEGs into miRNA-RNA network
and construct a sub network, which includes 5 genes,
5 miRNAs and 6 edges. Mir124 and Mir21 are also
associated with prolactinoma.
3 Discussion
In this study, we use GEO data to identify DEGs in
prolactinoma by hierarchical clustering analysis,
enrichment analysis and PPI network, and analyze the
relationship between DEGs and prolactinoma.
The result of hierarchical clustering demonstrates that
the gene expression level between tumor and normal
samples has stable gene expession signatures, which is
coincident with previous studies (2012). And the DEGs
are mainly enriched in hormone-related biological
process and many development of sex. Prolactinoma
is caused by the hypersecretion of prolactin, which
always happens in hypophysis and hypothalamus. The
clinical manifestation is amenorrhea, galactorrhea and
hyperprolactinemia. For young female, it can lead to
delayed puberty and developmental retardation. For
young male, it can lead to developmental retardation
and sexual dysfunction. Besides it also can result in
vision disorder, headache and osteoporosis. The
enrichment of DEGs indicates that most DEGs are
correlated with hormone, which are related to
development of sex. The result means prolactinoma
