3.1 DE-miRNAs and DE-mRNAs in BC
This study included 21 miRNA expression data sets, including 4 RNA-Seq data sets with three from tissue (GSE131599, GSE117452 and GSE68085), one from peripheral blood (GSE72080), and 17 microarray data sets from tissue, peripheral blood, serum and plasma. There were three gene expression RNA-Seq datasets, including two from tissue (GSE52194 and GSE99680) and one from peripheral blood (GSE41245), five gene expression microarray datasets from tissue samples, shown in Figure 2A. Table 2 shows the information of GEO datasets in this article. Upregulated and downregulated DEMs/DEGs in BCs vs. controls were identified based on log2FC (BC vs. normal). Totally 27 DE-miRNAs and 135 DE-mRNAs were the intersections of TarBase and miRTarBase datasets shown in Figure 2B.
Table 2
Information pertaining to the selected GEO datasets for breast cancer.
|
|
|
|
|
|
|
|
Experiment Type
|
Source name
|
GEO Accession
|
Platform
|
Group
|
|
Tumor
|
Control
|
microRNA expression
|
Array
|
Tissue
|
GSE144463
|
GPL15468
|
40
|
10
|
GSE58606
|
GPL18838
|
122
|
11
|
GSE38167
|
GPL14943
|
44
|
23
|
GSE48088
|
GPL14613
|
33
|
3
|
GSE44124
|
GPL14767
|
50
|
3
|
GSE32922
|
GPL7723
|
22
|
15
|
GSE45666
|
GPL14767
|
93
|
15
|
GSE42072
|
GPL16249
|
7
|
7
|
GSE26659
|
GPL8227
|
77
|
17
|
GSE7842
|
GPL5173
|
45
|
26
|
Serum
|
GSE98181
|
GPL21572
|
24
|
24
|
Plasma
|
GSE118782
|
GPL8786
|
30
|
12
|
GSE41526
|
GPL8179
|
40
|
20
|
GSE22981
|
GPL8179
|
20
|
20
|
Peripheral blood
|
GSE83270
|
GPL22003
|
6
|
6
|
GSE53179
|
GPL16550
|
11
|
5
|
GSE31309
|
GPL14132
|
48
|
57
|
Sequencing
|
Tissue
|
GSE131599
|
GPL18573
|
189
|
2
|
GSE117452
|
GPL16791
|
58
|
10
|
GSE68085
|
GPL10999
|
103
|
11
|
Peripheral blood
|
GSE72080
|
GPL11154
|
14
|
18
|
Gene expression
|
Array
|
Tissue
|
GSE50428
|
GPL13648
|
21
|
10
|
GSE59246
|
GPL13607
|
86
|
19
|
GSE71053
|
GPL570
|
6
|
12
|
GSE115275
|
GPL21827
|
6
|
6
|
GSE64790
|
GPL19612
|
3
|
3
|
Sequencing
|
Tissue
|
GSE52194
|
GPL11154
|
17
|
3
|
GSE99680
|
GPL18573
|
14
|
19
|
Peripheral blood
|
GSE41245
|
GPL14761
|
10
|
20
|
3.2 Function enrichment and pathway analyses
For the target miRNAs and mRNAs screened in the database, KEGG signaling pathway analysis and GO functional annotation analysis were performed. According to the analysis, these 27 DE-miRNAs are associated with various solid tumors including breast cancer, such as glioma, prostate cancer, bladder cancer, colorectal cancer, thyroid cancer, pancreatic cancer, lung cancer and melanoma, etc. Mainly involved in cellular nitrogen compound metabolism, biosynthesis, gene expression and cellular protein modification, etc. Mainly enriched in cellular components such as organelles, cell movement components, cytosol, nucleoplasts, and protein complexes. Involved in ion binding, enzyme binding, enzyme activity regulation, protein binding transcription factor activity regulation, nucleic acid binding transcription factor regulation and other molecular functions. (Shows in Figure S1-S4)
Among the 135 DE-mRNAs, the up-regulated mRNAs are mainly involved in biological processes such as DNA recombination, regulation of nuclease activity, and regulation of chromosome segregation; they are mainly enriched in nuclear chromosomes, MCM complexes, mitochondrial spindles and other cellular components; significantly enriched in proteins Molecular functions such as C-terminal binding, Cadherin binding, S100 protein binding, and cell adhesion collection. The down-regulated mRNAs are mainly involved in focal adhesion, regulation of actin cytoskeleton, leukocyte transendothelial migration, AMP signaling and other signaling pathways; they are involved in biological processes such as cell-matrix adhesion, cell behavior changes, and actin filament action; they are mainly enriched in Collagen-containing extracellular matrix, cell-matrix junction, cell surface and other cellular components; significantly enriched in molecular functions such as growth factor binding, kinesin binding, cytokine binding, and integrin binding. According to the results of functional enrichment and pathway analysis, the down-regulated DE-mRNAs are closely related to actin filaments. (Shows in Figure S5)
3.3 Negative miRNA/mRNA regulatory pairs related to BC
miRTarBase and TarBase were utilized to select experimentally verified target mRNAs associated with differentially expressed miRNAs. Negative miRNA-mRNA pairs were obtained based on intersections between 135 DE-mRNAs and two databases. Then, the Pearson's correlation analysis method was utilized to filter out ten miRNA-mRNA pairs with significant negative correlations (adjusted p<0.05) in TCGA. Upregulated miRNA/downregulated mRNA pairs were miR-21-5p/PIK3R1, miR-182-5p/ARRDC3, miR-96-5p/FOXO1, miR-200c-3p/FBLN5 and miR-342-3p/TACC1, and downregulated miRNA/upregulated mRNA pairs were miR-195-5p/RACGAP1, miR-139-5p/TPD52, miR-205-5p/HMGB3, miR-125b-5p/PARP1 and miR-145-5p/TPM3. They are listed in Table 3. Through the screening of databases, we identified these ten pairs of negatively correlated miRNA/mRNA pairs for experimental verification.
Table 3
Pearson's correlation analysis of miRNA-mRNA pairs in breast cancer.
|
|
|
|
miRNA(up)
|
mRNA(down)
|
p-value
|
r-value
|
21-5p
|
PIK3R1
|
8.02E-09
|
-0.16956
|
182-5p
|
ARRDC3
|
2.70E-08
|
-0.163531
|
96-5p
|
FOXO1
|
2.33E-20
|
-0.268737
|
200c-3p
|
FBLN5
|
3.25947E-05
|
-0.122556
|
342-3p
|
TACC1
|
1.02468E-05
|
-0.130085
|
miRNA(down)
|
mRNA(up)
|
p-value
|
r-value
|
195-5p
|
RACGAP1
|
1.46E-18
|
-0.256018
|
139-5p
|
TPD52
|
4.58E-15
|
-0.228997
|
205-5p
|
HMGB3
|
0.001584085
|
-0.093331
|
125b-5p
|
PARP1
|
4.83E-16
|
-0.236886
|
145-5p
|
TPM3
|
8.87E-13
|
-0.209282
|
3.4 Verification of miRNA and mRNA amounts in the BC tissue
To investigate whether the 10 DE-miRNAs and 10 DE-mRNAs are differentially expressed between BC and benign breast disease tissues, ploy(A) qRT-PCR was performed to analyze their expression in 40 tumor and 40 benign breast disease tissue samples. The results showed that among miRNAs, miRNA-205-5p, miRNA-139-5p, miR-145-5p and miR-96-5p met the standard. The test results for mRNAs targeted by these 4 miRNAs showed TPD52 (p=0.021, FC=1.287), HMGB3 (p=0.015, FC=1.329), TPM3 (p=0.029, FC=3.993) and FOXO1(p=0.033, FC=0.239)also met the standard. The complete qRT-PCR data are shown in Figure 3A. Next, Pearson correlation analysis was performed to examine the interactions between DE-miRNAs and DE-mRNAs. Among the miRNA-mRNA pairs, miR-205-5p/HMGB3 (p=0.008, r=-0.350) and miR-96-5p/FOXO1 (p=0.028, r=-0.290) showed a significant negative correlation (Figure 3B and Table 4).
Table 4
Pearson’s correlation analysis of miRNA-mRNA pairs in FFPE breast cancer samples.
miRNA (up)
|
p-value
|
Fold change (2-ΔΔCT)
|
mRNA (down)
|
p-value
|
Fold change (2-ΔΔCT)
|
Pearson's correlation
|
p-value
|
r-value
|
21-5p
|
0.823
|
1.177
|
PIK3R1
|
< 0.0001
|
0.131
|
0.087
|
0.514
|
182-5p
|
0.133
|
1.461
|
ARRDC3
|
0.005
|
0.198
|
0.016
|
0.31
|
96-5p
|
0.025
|
3.415
|
FOXO1
|
0.033
|
0.239
|
0.028
|
-0.29
|
200c-3p
|
0.251
|
1.395
|
FBLN5
|
0.029
|
0.45
|
0.021
|
0.3
|
342-3p
|
0.197
|
1.193
|
TACC1
|
< 0.0001
|
0.228
|
< 0.0001
|
0.48
|
miRNA (down)
|
|
|
mRNA (up)
|
|
|
p-value
|
r-value
|
195-5p
|
0.196
|
0.664
|
RACGAP1
|
0.204
|
1.996
|
0.016
|
-0.31
|
139-5p
|
0.019
|
0.261
|
TPD52
|
0.021
|
1.287
|
0.004
|
0.55
|
205-5p
|
0.009
|
0.338
|
HMGB3
|
0.015
|
1.329
|
0.008
|
-0.35
|
125b-5p
|
0.081
|
0.235
|
PARP1
|
0.004
|
2.349
|
0.095
|
0.23
|
145-5p
|
0.002
|
0.195
|
TPM3
|
0.029
|
3.993
|
0.494
|
0.091
|
IHC images in the HPA database demonstrated elevated HMGB3 amounts in BC cells compared with normal breast cells, while the expression of FOXO1 in BC cells was lower than that of normal breast cells (Figure 4).
3.5 Predictive value of miRNA-mRNA regulator pairs in BC
Logistic regression analysis was performed for evaluating the predictive value of the miR-205-5p/HMGB3 and miR-96-5p/FOXO1 panel by including 2 miRNA-mRNA pairs in the qRT-PCR validation cohort containing 40 BC tissues. ROC curve (Logistic regression model = -0.2286 + 0.0082*miR-96-5p + -0.8506*FOXO1 + -0.2136*miR-205-5p + 0.2818*HMGB3) analysis (Figure 5A) confirmed this model had a good diagnostic value (AUC=0.856, CI 0.759-0.953). ROC curves were also generated for the 2 DE-miRNAs and 2 DE-mRNAs in TCGA (Figure 5B), the predicted value of the independent indicator is lower than the predicted value of the combination(AUC=0.999) (Figure 5C and Figure 5D).
We also analyzed the expression levels of the 2 DE-mRNAs in miRNA-mRNA pairs based on cancer stage. As shown in Figure 6, we found that the expression levels of the 2 DE-mRNAs in various breast cancer stages had no significant difference, indicating they can differentiate non-malignant breast tumors from breast cancer of any stage, they all had diagnostic and predictive significance.
3.6 Overall survival data
Since the clinical tissue samples were limited, with the GEO database having no clinical data, survival analysis was conducted based on TCGA data. The HRs of various clinical parameters in the TCGA testing set (n=1880) were estimated by univariable and multivariable cox regression analyses. As depicted in Figure 7, HMGB3 level had a significant correlation with OS (HR=1.39, 95% CI 1.01 to 1.91; p=0.044) in TCGA. This demonstrated HMGB3 has a particular influence on the prognosis of breast cancer, and provided novel insights into breast cancer treatment. We did not have extra survival data to estimate the prognostic model, and more research is required about the predictive value of the 2 miRNA-mRNA regulatory pairs in BC.
3.7 Tumor-related phenotypes associated with signatures
We used a computational method (CIBERSORT) to analyze multiple gene expression profiles in breast cancer to infer the proportions of 22 immune cell subsets. There were 12 types of immune cells with differential amounts in BC and control samples, as shown in Figure 8A (all results are listed in Table S2). We further investigated the associations of each cell type with miRNA/target mRNA expression. As shown in Figure 8B, miR-205-5p and its target gene HMGB3 were related to activated dendritic cells; miR-96-5p and its target gene FOXO1 were related to M0 macrophages. In the analysis of the tumor microenvironment, miR-96-5p/FOXO1 could interact with DNA methylation, tumor immunity and inflammation in the tumor microenvironment (Figure 8C).