CRC is characterized by upregulated UBTD1 mRNA and protein levels
The study analyzed UBTD1 gene expression patterns in distinct human cancers and normal tissues utilizing TCGA-based data. The UBTD1 mRNA expression levels varied significantly between malignant cancers and their corresponding normal tissues, with notable distinctions observed in stomach adenocarcinoma (STAD), Thyroid carcinoma (THCA), Kidney Chromophobe (KICH), Prostate adenocarcinoma (PRAD), Liver hepatocellular carcinoma (LIHC), Lung squamous cell carcinoma (LUSC), Lung adenocarcinoma (LUAD), Kidney renal clear cell carcinoma (KIRC), and colon adenocarcinoma (COAD) (Fig. 1A, B). Specifically, UBTD1 was shown to be upregulated in CRC (Fig. 1C, D). Validation of UBTD1 expression was conducted utilizing supplementary GEO datasets (GSE22598, GSE110224). Analysis across these three disparate datasets revealed an upregulation of UBTD1 in CRC tissues in comparison with adjoining normal tissues (Fig. 1F–G). The AUC of the ROC curve for UBTD1 expression was established as 0.863 (95% CI = 0.818–0.908), highlighting a promising predictive capacity for discriminating between tumor and normal samples (Fig. 1E). Subsequently, an IHC assay was utilized to evaluate UBTD1 expression in tumor and adjoining normal tissue specimens derived from CRC samples at Shanghai Outdo Biotech Company. in comparison with normal tissues, UBTD1 IHC scores in tumors were increased significantly, according to the findings (Fig. 1H, I).
UBTD1 expression is correlated with the CRC pathological stage
We probed into the UBTD1 expression patterns in 644 CRC patients from the TCGA database and investigated their associations with various clinical and pathological characteristics. By using Welch one-way ANOVA accompanied by Bonferroni's post-hoc test, the levels of UBTD1 expression were found to be significantly related to the T stage, N stage, and pathologic stage. Nevertheless, UBTD1 expression did not exhibit any statistically significant correlations with M stage, age, or gender. (Fig. 2A–I). The threshold for stratifying the samples into low- and high-expression subgroups was established utilizing the median UBTD1 expression value. Subsequently, an evaluation was conducted to examine the association of UBTD1 expression in cancerous samples with a range of clinicopathological factors, such as clinical stage, T stage, distant metastasis, N stage, gender, age at diagnosis, OS, DSS, and PFI events. Table 1 presents a summary of UBTD1 expression correlations with clinicopathological features in 644 CRC patients. The patients with higher UBTD1 levels had more advanced pathological N stage, OS, DSS, and PFI events (p = 0.001, p = 0.014, p < 0.001, and p = 0.015, respectively) as opposed to those with lower levels. There were significant variations in the UBTD1 levels between the N stage (p = 0.011) and the pathological stage (p = 0.022) in the logistics association analysis (Table 2). Additionally, OS, DSS, and PFI times were all reduced in CRC patients with UBTD1 expression upregulation, according to the KM curves (Fig. 2J-L).
Table 1
The association of UBTD1 expression with clinicopathological features in the TCGA cohort.
Characteristics | Low expression of UBTD1 | High expression of UBTD1 | P value |
n | 322 | 322 | |
Pathologic T stage, n (%) | | | 0.470 |
T1 | 12 (1.9%) | 8 (1.2%) | |
T2 | 60 (9.4%) | 51 (8%) | |
T3 | 214 (33.4%) | 222 (34.6%) | |
T4 | 33 (5.1%) | 41 (6.4%) | |
Pathologic N stage, n (%) | | | 0.001 |
N0 | 200 (31.2%) | 168 (26.2%) | |
N1 | 78 (12.2%) | 75 (11.7%) | |
N2 | 42 (6.6%) | 77 (12%) | |
Pathologic M stage, n (%) | | | 0.130 |
M0 | 239 (42.4%) | 236 (41.8%) | |
M1 | 37 (6.6%) | 52 (9.2%) | |
Pathologic stage, n (%) | | | 0.108 |
Stage I | 61 (9.8%) | 50 (8%) | |
Stage II | 128 (20.5%) | 110 (17.7%) | |
Stage III | 86 (13.8%) | 98 (15.7%) | |
Stage IV | 37 (5.9%) | 53 (8.5%) | |
Gender, n (%) | | | 0.236 |
Female | 158 (24.5%) | 143 (22.2%) | |
Male | 164 (25.5%) | 179 (27.8%) | |
Age, n (%) | | | 0.152 |
<= 65 | 129 (20%) | 147 (22.8%) | |
> 65 | 193 (30%) | 175 (27.2%) | |
OS event, n (%) | | | 0.014 |
Alive | 270 (41.9%) | 245 (38%) | |
Dead | 52 (8.1%) | 77 (12%) | |
DSS event, n (%) | | | < 0.001 |
No | 281 (45.2%) | 263 (42.3%) | |
Yes | 24 (3.9%) | 54 (8.7%) | |
PFI event, n (%) | | | 0.015 |
No | 253 (39.3%) | 226 (35.1%) | |
Yes | 69 (10.7%) | 96 (14.9%) | |
Table 2
Logistics association between UBTD1 expression and clinicopathologic features
Characteristics | Total (N) | OR (95% CI) | P value |
Pathologic T stage (T3&T4 vs. T1&T2) | 641 | 1.299 (0.884–1.911) | 0.183 |
Pathologic N stage (N1&N2 vs. N0) | 640 | 1.508 (1.100–2.067) | 0.011 |
Pathologic M stage (M1 vs. M0) | 564 | 1.423 (0.900–2.251) | 0.131 |
Pathologic stage (Stage III&Stage IV vs. Stage I&Stage II) | 623 | 1.450 (1.055–1.993) | 0.022 |
Age (> 65 vs. <= 65) | 644 | 0.796 (0.582–1.088) | 0.152 |
Gender (Male vs. Female) | 644 | 1.206 (0.885–1.644) | 0.236 |
UBTD1 Expression Upregulation is Correlated with Unfavorable Patient Prognosis in CRC
Our study examined the prognostic value of UBTD1 in predicting OS, PFI, and DSS in CRC. Lower levels of UBTD1 were associated with improved OS, DSS, and PFI outcomes, as evidenced by KM survival analysis (Fig. 2J-L). The potential of UBTD1 expression and other clinicopathological features as independent risk factors for CRC patients was investigated utilizing univariate and multivariate models. According to the univariate analysis, most clinical features were strongly correlated with a negative OS, including age > 65 years (p < 0.001), T3 and T4 stages (p = 0.004), N1 and N2 stages (p < 0.001), M1 stage (p < 0.001), TNM III/IV stages (p < 0.001), and UBTD1 expression upregulation (p = 0.003). The same results are reflected in multivariate analysis (Table 3). Additionally, T3 and T4 stages (p = 0.002), N1 and N2 stages (p < 0.001), M1 stage (p < 0.001), and UBTD1 expression upregulation (p < 0.001) were strongly correlated with reduced DSS in the univariate analysis. Furthermore, the M stage (p < 0.001), TNM III/IV stages (p = 0.013), and UBTD1 levels (p = 0.023) independently act as OS predictors in the multivariate analysis (Table 4). It was also found that T3 and T4 stages (p < 0.001), N1 and N2 stages (p < 0.001), M1 stage (p < 0.001), TNM III/IV stages (p < 0.001), and UBTD1 expression upregulation (p = 0.002) significantly correlated with a reduced PFI in the univariate analysis. Moreover, the independent function of the T3 and T4 stages (p = 0.042), M stage (p < 0.001), and UBTD1 expression upregulation (p = 0.040) in predicting PFI were shown in the multivariate analysis (Table 5).
Table 3
The univariate and multivariate analyses of OS.
Characteristics | Total(N) | Univariate analysis | | Multivariate analysis |
Hazard ratio (95% CI) | P value | Hazard ratio (95% CI) | P value |
Pathologic T stage | 640 | | | | | |
T1&T2 | 131 | Reference | | | Reference | |
T3&T4 | 509 | 2.468 (1.327–4.589) | 0.004 | | 2.219 (1.009–4.880) | 0.048 |
Pathologic N stage | 639 | | | | | |
N0 | 367 | Reference | | | Reference | |
N1&N2 | 272 | 2.627 (1.831–3.769) | < 0.001 | | 0.360 (0.136–0.952) | 0.039 |
Pathologic M stage | 563 | | | | | |
M0 | 474 | Reference | | | Reference | |
M1 | 89 | 3.989 (2.684–5.929) | < 0.001 | | 2.310 (1.430–3.731) | < 0.001 |
Pathologic stage | 622 | | | | | |
Stage I&Stage II | 348 | Reference | | | Reference | |
Stage III&Stage IV | 274 | 2.988 (2.042–4.372) | < 0.001 | | 5.793 (1.973–17.014) | 0.001 |
Gender | 643 | | | | | |
Female | 301 | Reference | | | | |
Male | 342 | 1.054 (0.744–1.491) | 0.769 | | | |
Age | 643 | | | | | |
<= 65 | 276 | Reference | | | Reference | |
> 65 | 367 | 1.939 (1.320–2.849) | < 0.001 | | 3.022 (1.930–4.731) | < 0.001 |
UBTD1 | 643 | | | | | |
Low | 321 | Reference | | | Reference | |
High | 322 | 1.723 (1.210–2.452) | 0.003 | | 1.751 (1.178–2.602) | 0.006 |
Table 4
The univariate and multivariate analyses of DSS.
Characteristics | Total(N) | Univariate analysis | | Multivariate analysis |
Hazard ratio (95% CI) | P value | Hazard ratio (95% CI) | P value |
Pathologic T stage | 618 | | | | | |
T1&T2 | 129 | Reference | | | Reference | |
T3&T4 | 489 | 6.440 (2.029–20.441) | 0.002 | | 2.734 (0.830–9.009) | 0.098 |
Pathologic N stage | 617 | | | | | |
N0 | 358 | Reference | | | Reference | |
N1&N2 | 259 | 4.119 (2.496–6.797) | < 0.001 | | 0.511 (0.195–1.336) | 0.171 |
Pathologic M stage | 542 | | | | | |
M0 | 455 | Reference | | | Reference | |
M1 | 87 | 7.471 (4.647–12.012) | < 0.001 | | 3.726 (2.075–6.693) | < 0.001 |
Pathologic stage | 601 | | | | | |
Stage I&Stage II | 339 | Reference | | | Reference | |
Stage III&Stage IV | 262 | 5.716 (3.240–10.083) | < 0.001 | | 4.502 (1.372–14.774) | 0.013 |
Gender | 621 | | | | | |
Female | 290 | Reference | | | | |
Male | 331 | 1.207 (0.769–1.895) | 0.412 | | | |
Age | 621 | | | | | |
<= 65 | 273 | Reference | | | | |
> 65 | 348 | 1.421 (0.894–2.257) | 0.137 | | | |
UBTD1 | 621 | | | | | |
Low | 304 | Reference | | | Reference | |
High | 317 | 2.420 (1.496–3.917) | < 0.001 | | 1.816 (1.084–3.041) | 0.023 |
Table 5
The univariate and multivariate analyses of PFI.
Characteristics | Total(N) | Univariate analysis | | Multivariate analysis |
Hazard ratio (95% CI) | P value | Hazard ratio (95% CI) | P value |
Pathologic T stage | 640 | | | | | |
T1&T2 | 131 | Reference | | | Reference | |
T3&T4 | 509 | 3.198 (1.814–5.636) | < 0.001 | | 1.855 (1.024–3.360) | 0.042 |
Pathologic N stage | 639 | | | | | |
N0 | 367 | Reference | | | Reference | |
N1&N2 | 272 | 2.624 (1.916–3.592) | < 0.001 | | 0.888 (0.378–2.086) | 0.785 |
Pathologic M stage | 563 | | | | | |
M0 | 474 | Reference | | | Reference | |
M1 | 89 | 5.577 (3.945–7.884) | < 0.001 | | 4.411 (2.825–6.885) | < 0.001 |
Pathologic stage | 622 | | | | | |
Stage I&Stage II | 348 | Reference | | | Reference | |
Stage III&Stage IV | 274 | 2.924 (2.115–4.044) | < 0.001 | | 1.389 (0.537–3.593) | 0.498 |
Gender | 643 | | | | | |
Female | 301 | Reference | | | | |
Male | 342 | 1.217 (0.892–1.660) | 0.216 | | | |
Age | 643 | | | | | |
<= 65 | 276 | Reference | | | | |
> 65 | 367 | 1.006 (0.737–1.371) | 0.972 | | | |
UBTD1 | 643 | | | | | |
Low | 321 | Reference | | | Reference | |
High | 322 | 1.634 (1.198–2.228) | 0.002 | | 1.419 (1.016–1.980) | 0.040 |
Potential Involvement of UBTD1 in CRC Malignant Progression
We initially selected the 50 top-ranked significantly correlated genes with UBTD1, as illustrated in the heatmap, to explore the biological activities of UBTD1 in CRC (Fig. 3A). Subsequently, these genes were subjected to GO and KEGG analyses. Additionally, the following were found to be predominantly linked to co-expressed genes that exhibited a correlation coefficient > 0.6 with UBTD1, as indicated by the GO term annotation: collagen-containing extracellular matrix (ECM), ECM organization, collagen metabolic process, extracellular structure organization, endoplasmic reticulum lumen, and basement membrane. A review of the KEGG pathways showed the enrichment of the majority of the UBTD1-associated genes in the following: protein digestion and absorption, focal adhesion, and the relaxin signaling pathway (Fig. 3B). Additionally, 1123 DEGs were found between the low- and high-expression groups with 727 and 396 up- and down-regulated genes, respectively, in the high-expression subgroup (refer to Fig. 3C). Subsequently, we conducted GO and KEGG pathway analyses. A bubble map revealed the enrichment of co-expressed DEGs in the endoplasmic reticulum lumen, extracellular structure organization, collagen-containing ECM, ECM organization, external encapsulating structure organization, collagen timer for GO pathway analysis, and staphylococcus aureus infection, protein digestion and absorption, as well as coagulation and complement cascades for KEGG pathway analysis. On the contrary, the enrichment of downregulated DEGs was primarily found in protein-DNA complex, identification of the chemical signal that contributes to the olfaction, sensory perception of smell, DNA packaging complex, nucleosome for GO pathway analysis, and alcoholism, systemic lupus erythematosus and olfactory transduction for KEGG pathway analysis (Fig. 3D). Additionally, GSEA results from the KEGG database demonstrated the correlation of UBTD1 expression upregulation with the cytokine-cytokine receptor interaction, focal adhesion, ECM receptor interaction, chemokine signaling, cell adhesion molecules cams, and leukocyte transendothelial migration pathway (Fig. 3E, F). Overall, these findings point to the potential involvement of UBTD1 in the CRC malignant progression.
UBTD1 Is Linked to Immune Infiltration in CRC
Spearman correlation was conducted to determine how UBTD1 expression correlated with several distinct types of immune cells, as measured by the CIBERSORT, EPIC, and QUAN-TISEQ. Notably, CIBERSORT showed that UBTD1 expression in CRC was linked to the infiltration levels of T cell CD4 + memory resting (r = -0.281, p < 0.001), B cell plasma (r = -0.276, p < 0.001), T cell follicular helper (r = -0.136, p < 0.001), myeloid dendritic cell activated (r = -0.132, p < 0.001), macrophage M1 (r = 0.140, p < 0.001), macrophage M2 (r = 0.184, p < 0.001), neutrophil (r = 0.240, p < 0.001) and macrophage M0 (r = 0.276, p < 0.001). Additionally, EPIC demonstrated the association UBTD1 expression in CRC with uncharacterized cell (r = -0.498, p < 0.001), T cell CD8+ (r = -0.296, p < 0.001), T cell CD4+ (r = -0.228, p < 0.001), endothelial cell (r = 0.388, p < 0.001), NK cell (r = 0.398, p < 0.001) and macrophage (r = 0.505, p < 0.001). Moreover, QUANTISEQ showed that UBTD1 expression in CRC was linked to the infiltrating levels of T cell CD4+ (r = -0.270, p < 0.001), T cell regulatory (r = 0.155, p < 0.001), T cell CD8+ (r = 0.170, p < 0.001), macrophage M1 (r = 0.113, p = 0.005) and macrophage M2 (r = 0.189, p < 0.001 (Fig. 4, Table 6). The ESTIMATE algorithm was employed to obtain the immune, stromal, and ESTIMATE scores for colorectal cancer. Individuals with high UBTD expression recorded higher scores than those with low UBTD levels, demonstrating a significant positive correlation (Fig. 5A-C).
Notably, UBTD1 expression was strongly associated with macrophages, especially M2 macrophage, which is an integral part of the TME and contributes to the modulation of angiogenesis, remodeling of the ECM, the proliferation of cancerous cells, metastases, immunosuppressive function, chemoresistance, and insensitivity to immune checkpoint blockade treatment. The correlation of UBTD1 expression with markers associated with various subtypes of macrophages was further investigated. Our findings revealed a significantly stronger correlation between UBTD1 and M2 macrophages, as indicated by the positive associations with CD163 (r = 0.411, p < 0.001) and MRC1 (r = 0.331, p < 0.001). (Fig. 5D-F). The results of this study indicate a potential role for UBTD1 in the transition from M1 to M2 polarization in colorectal cancer (CRC). Additionally, we compared the expression of UBTD1 with that of other genes implicated in immune regulation. Our findings demonstrate that UBTD1 expression is significantly linked to most targets within the immunological microenvironment (see Fig. 5G). The data presented in Fig. 5H demonstrates a strong correlation between transforming growth factor-beta 1 (TGFB1) and UBTD1. Additionally, analysis of Kaplan-Meier curves in Fig. 5I indicates that colorectal cancer (CRC) patients with elevated UBTD1 expression exhibit a shorter overall survival (OS) time. This observation suggests a potential mechanism by which increased UBTD1 levels may contribute to a poor prognosis in CRC. Furthermore, these findings suggest a role for UBTD1 in modulating immune infiltration in CRC.
Table 6
Correlation of UBTD1 expression with immune infiltration in CRC
Category | ID | Relevance | P value |
CIBERSORT | T cell CD4 + memory resting | -0.28128 | < 0.001 |
B cell plasma | -0.27592 | < 0.001 |
T cell follicular helper | -0.13563 | 0.000709 |
Myeloid dendritic cell activated | -0.13205 | 0.000982 |
Eosinophil | -0.06588 | 0.101252 |
T cell CD4 + memory activated | -0.06484 | 0.106754 |
B cell naive | -0.06451 | 0.108546 |
T cell CD4 + naive | -0.06076 | 0.130708 |
NK cell resting | -0.0557 | 0.16601 |
T cell CD8+ | -0.05217 | 0.194552 |
Mast cell resting | -0.04769 | 0.235739 |
Monocyte | -0.04615 | 0.251241 |
Myeloid dendritic cell resting | -0.02188 | 0.586633 |
T cell gamma delta | -0.02158 | 0.591668 |
Mast cell activated | 0.005936 | 0.882733 |
B cell memory | 0.023304 | 0.56248 |
NK cell activated | 0.034967 | 0.384746 |
T cell regulatory (Tregs) | 0.056515 | 0.159875 |
Macrophage M1 | 0.139533 | < 0.001 |
Macrophage M2 | 0.183907 | < 0.001 |
Neutrophil | 0.239527 | < 0.001 |
Macrophage M0 | 0.275959 | < 0.001 |
EPIC | uncharacterized cell | -0.49793 | < 0.001 |
T cell CD8+ | -0.29625 | < 0.001 |
T cell CD4+ | -0.22822 | < 0.001 |
B cell | 0.047801 | 0.234635 |
Endothelial cell | 0.387576 | < 0.001 |
NK cell | 0.39753 | < 0.001 |
Macrophage | 0.504696 | < 0.001 |
QUANTISEQ | T cell CD4+ (non-regulatory) | -0.27006 | < 0.001 |
NK cell | -0.05679 | 0.157847 |
uncharacterized cell | -0.05304 | 0.187156 |
Neutrophil | -0.03879 | 0.334955 |
Monocyte | -0.01143 | 0.776299 |
B cell | 0.02793 | 0.487573 |
Myeloid dendritic cell | 0.063791 | 0.112562 |
Macrophage M1 | 0.112592 | 0.005004 |
T cell regulatory (Tregs) | 0.154957 | < 0.001 |
T cell CD8+ | 0.170115 | < 0.001 |
Macrophage M2 | 0.189415 | < 0.001 |