Tubulin polymerization promoting protein family member 3 (TPPP3) is a kind of protein that can mediate the dynamics and stability of microtubules. However, the correlations of TPPP3 between prognosis and immune infiltrates in different tumors are still unclear. The analysis of TPPP3 expression was performed via Oncomine and Gene Expression Profiling Interactive Analysis (GEPIA) website. We also used GEPIA to assess the impact of TPPPT3 on clinical outcomes. The related pathways involved in TPPP3 were analyzed by gene-set enrichment analysis (GSEA), and the correlation between TPPP3 and immune infiltration was studied by Tumor Immune Estimation Resource2.0 (TIMER 2.0). The TPPP3 expression was significantly reduced in head and neck squamous carcinoma (HNSC) compared to adjacent tissues. In addition, the low expression of TPPP3 in HNSC was significantly associated with prognosis. The pathways closely related to the low expression of TPPP3 are “Antigen Processing and Presentation,” “Primary Immunodeficiency,” and so on. The TPPP3 expression was negatively correlated with the level of CD8+ T cell, B cell, and myeloid dendritic cell infiltration in HNSC. The TPPP3 expression is closely related to multiple immunomarkers in CD8+ T cell and Myeloid dendritic cells. These data indicate that TPPP3 is associated with multiple cancers and involves multiple immune-related pathways, and TPPP3 is associated with immune infiltration levels. Besides, the TPPP3 expression may help regulate tumor-associated CD8 + T cells, DC cells in HNSC. We conclude TPPP3 can be considered as a biomarker for predicting head and neck squamous cell carcinoma prognosis and immune infiltration.
Head and neck squamous carcinoma (HNSC) is one of the most frequent tumors in Southeast Asia and southern China. The mechanism of HNSC development is complex and involves the alteration of polygenic and multisignaling pathways [
TPPP3, also known as TPPP/p20, is a protein-coding gene located on chromosome 16 that was first reported in 2006. TPPP3 is a brain-specific protein homologous to TPPP/p25, expressed in many human cells and organs, which could induce tubulin polymerization and microtubule (MT) bundling [
A growing number of researchers in recent years have begun to explore the relationship between TPPP3 and tumors. Studies suggest that reduced TPPP3 can lead to abnormal mitoses, such as the formation of multipolar spindles and chromosome segregation errors, leading to HeLa apoptosis [
In the tumor microenvironment, immune and stromal cells are two major types of nontumor components. The extent of tumor immune infiltration and stromal cells has significant value for tumor diagnosis and prognosis evaluation. This study provides a comprehensive analysis of TPPP3 expression in cancer databases and its relationship to the prognosis of cancer patients. Then, we performed pathological verification with clinical specimens. In addition, we also examined the relationship between TPPP3 and tumor-infiltrating immune cells in HNSC through the Tumor Immunity Estimation Resource 2.0(TIMER 2.0). This report clarifies the important role of TPPP3 in HNSC and provides evidence for the relationship between TPPP3 and tumor-immune cell infiltration interactions.
To understand the differences in TPPP3 expression between human tumor and nontumor tissues, we utilized the Oncomine database to analyze the expression levels of TPPP3 in multiple cancer types and different tumors and normal tissues. Comparing to normal tissues, the study demonstrated that TPPP3 observed lower expression in bladder cancer, brain cancer, breast cancer, head and neck cancer, kidney cancer, lung cancer, melanoma, ovarian cancer, and sarcoma and high expression in gastric cancer (Figure
TPPP3 expression levels in different types of human tumors. (a) In the Oncomine database, TPPP3 expression in different cancer datasets compared to normal tissues. (b) Human TPPP3 expression levels in different tumor types from Timer. BRCA (breast invasive carcinoma), CESC (cervical squamous cell carcinoma and endocervical adenocarcinoma), CHOL (cholangiocarcinoma), COAD (colon adenocarcinoma), DLBC (Lymphoid Neoplasm Diffuse Large B-cell Lymphoma), ESCA (Esophageal carcinoma), GBM (Glioblastoma multiforme), HNSC (head and neck squamous cell carcinoma), KICH (kidney chromophobe), KIRC (kidney renal clear cell carcinoma), KIRP (kidney renal papillary cell carcinoma), LAML (Acute Myeloid Leukemia), LGG (Brain Lower Grade Glioma), LIHC (Liver hepatocellular carcinoma), LUAD (lung adenocarcinoma), LUSC (lung squamous cell carcinoma), MESO (Mesothelioma), OV (ovarian serous cystadenocarcinoma), PAAD (Pancreatic adenocarcinoma), PCPG (Pheochromocytoma and Paraganglioma), PRAD (Prostate adenocarcinoma), READ (Rectum adenocarcinoma), SARC (sarcoma), SKCM (Skin Cutaneous Melanoma), STAD (Stomach adenocarcinoma), TGCT (Testicular Germ Cell Tumors), THCA (Thyroid carcinoma), THYM (Thymoma), UCEC (Uterine Corpus Endometrial Carcinoma), UCS (Uterine Carcinosarcoma), and UVM (Uveal Melanoma).
To understand the prognosis of TPPP3 in tumors, Gene Expression Profiling Interactive Analysis (GEPIA) was used to determine whether TPPP3 expression is correlated with the prognosis of HNSC, LUAD, LUSC, KICH, BRCA, KIRC, and BLCA. (Figures
(a–g) Kaplan-Meier survival curves comparing the high and low expression of TPPP3 in different types of tumors by GEPIA. (h–y) list the most common functional gene sets enriched in HNSC samples with low and high expression of TPPP3.
To discover the underlying mechanism of TPPP3 and HNSC, Gene Set Enrichment Analysis (GSEA) was utilized to obtain the TPPP3-related gene collection based on the actual overall trend analysis and compare enrichment analysis such as Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). Consequently, the enrichment of 100 functional gene sets was obtained. The pathways closely related to the low expression of TPPP3 are “Antigen Processing and Presentation,” “Primary Immunodeficiency,” “RIG I Like Receptor Signaling Pathway,” “Endometrial Cancer,” and “P53 Signaling Pathway.” The pathways associated with TPPP3 high expression are “Parkingson Disease,” “Oxidative Phosphorylation,” and “Phenylalanine Metabolism” (Figures
Tumor-infiltrating lymphocytes are independent risk factors affecting tumor prognosis [
The correlation of TPPP3 expression with immune infiltration level in HNSC. TPPP3 expression is negatively correlated with infiltrating levels of CD8+ T cell, B cell, and myeloid dendritic cell. The infiltration level for each SCNA category is compared with the normal using a two-sided Wilcoxon rank-sum test.
To gain insight into the intrinsic link between TPPP3 and related immune cells, we applied the TIMER 2.0 database to analyze the correlation between TPPP3 genes in HNSC related immune infiltrating cells. We obtained results on the correlation between TPPP3 expression and marker genes of tumor infiltration-associated immune cells, including CD8+T cells (CD8A and CD8B), B cell (CD19 and CD79a), and Myeloid dendritic cell (HLA-DPB1, HLA-DQB1, HLA-DRA, HLA-DPA1, CD1C, NRP1, and ITGAX). The results manifested that TPPP3 expression levels were negatively correlated with most of the immune marker genes in HNSC (Figure
Scatterplots of correlations between TPPP3 expression and gene markers of CD8+T cells, B cell, and myeloid dendritic cell.
In the present research, the expression of TPPP3 in nasopharyngeal carcinoma (NPC) tissues was detected in 57 cases of NPC and 30 cases of normal tissue by immunohistochemistry, and the relationship between TPPP3 and clinicopathological features of NPC was analyzed at the same time. The results showed that the expression of TPPP3 in NPC was significantly lower than that in normal nasopharyngeal tissue; the difference was statistically significant (Figure
Expression of TPPP3 in nasopharyngeal carcinoma and nontumor epithelial tissue. (a) Nontumor epithelial tissue. (b) NPC tissue. (c) Analysis of TPPP3 expression levels in patients with NPC and normal tissues from GEO datasets GSE12452.
Immunohistochemical staining showed that TPPP3 in nasopharyngeal carcinoma was lower than that in normal nasopharyngeal mucosa.
Group | Positive (+) | Negative (-) | Sum | Positive rate (%) | |
---|---|---|---|---|---|
Nasopharyngeal carcinoma | 7 | 50 | 57 | 12.28 | <0.001 |
Normal nasopharyngeal mucosa | 27 | 3 | 30 | 90.00 |
The relationship between the expression of TPPP3 and the clinicopathological features of nasopharyngeal carcinoma.
Group | Negative (-) | Positive (+) | Positive proportion (%) | ||
---|---|---|---|---|---|
Gender | |||||
Male | 41 | 36 | 5 | 12.20 | >0.05 |
Female | 16 | 14 | 2 | 12.50 | |
Age | |||||
≤45 | 25 | 24 | 3 | 12.00 | >0.05 |
>45 | 32 | 28 | 4 | 12.50 | |
Differentiation or not | |||||
Differentiated | 6 | 5 | 1 | 16.67 | >0.05 |
Undifferentiated | 51 | 45 | 6 | 11.76 | |
T stage | |||||
T1, T2 | 21 | 19 | 2 | 9.52 | >0.05 |
T3, T4 | 36 | 31 | 5 | 13.89 | |
N stage | |||||
≥N1 | 52 | 46 | 6 | 11.54 | >0.05 |
N0 | 5 | 4 | 1 | 20.00 | |
M stage | |||||
M0 | 49 | 43 | 6 | 12.24 | >0.05 |
M1 | 8 | 7 | 1 | 12.50 | |
Clinical stage | |||||
I, II | 5 | 4 | 1 | 20.00 | >0.05 |
III, IV | 52 | 46 | 6 | 11.54 |
A growing number of researchers have been exploring the relationship between TPPP3 and tumor development in recent years. According to the Zhou et al.’s study, knockdown of TPPP3 inhibits cell proliferation of HeLa cells while inducing cell cycle arrest [
In this article, we first performed a pan-cancer analysis of TPPP3 expression. The Oncomine database and GEPIA were used to analyze the mRNA expression data of 31 tumors to check the expression level and prognosis of TPPP3 in different types of tumors. According to the results of the Oncomine database, we found that TPPP3 was lower expressed in breast cancer, head and neck cancer, kidney cancer, ovarian cancer, and sarcoma compared to normal tissues, while higher expression in gastric cancer. Furthermore, GEPIA demonstrated that compared with neighboring normal tissues, the expression of TPPP3 in HNSC, BLCA, BRCA, KICH, KIRC, LUAD, and LUSC was significantly reduced, while the expression of TPPP3 in CHOL and KIRC was significantly higher. We found that using different databases, TPPP3 expression levels differed among different tumor types, which may be due to the data collection method and the different biological characteristics of TPPP3. Interestingly, in these databases, we found consistency in TPPP3 expression in head and neck squamous cell carcinoma. In addition, the analysis of survival data indicates that low levels of TPPP3 expression are associated with a poor prognosis for HNSC.
In this research on the mechanism of TPPP3, we selected the transcript data of 70 cases HNSC in the TCGA database and performed GSEA analysis on these datasets. The pathways closely related to the low expression of TPPP3 are “Antigen Processing and Presentation,” “Primary Immunodeficiency,” “RIG I Like Receptor Signaling Pathway,” “Endometrial Cancer,” and “P53 Signaling Pathway.” Results also indicate that TPPP3 may be related to the mechanism of tumor immunity. Therefore, we shifted the research focus of TPPP3 to research on tumor immune infiltration. Our results indicate that TPPP3 expression is correlated with multiple immune cell infiltration levels in head and neck squamous cell carcinoma. There is a negative correlation between the expression of TPPP3 and the infiltration levels of CD8+T cells and B memory cells. However, TPPP3 expression is positively correlated with DC cells. Moreover, the correlation between TPPP3 expression and immune cell marker genes suggests that TPPP3 is regulating the immunological role of HNSC. Further, the genetic markers of CD8+ T cells and myeloid dendritic cells are weakly correlated with TPPP3 expression. These results reveal a potential regulatory role of TPPP3 in tumor-associated myeloid dendritic cell-mediated T cell toxic effects.
In addition, to further understanding of TPPP3 expression in head and neck tumors, we also performed immunohistochemistry on clinical NPC specimens and validated tumor and normal tissue TPPP3 mRNA expression in two GEO NPC datasets. The results we obtained are consistent with those of Oncomine and GEPIA in that TPPP3 expression is significantly reduced in the HNSC. But there is no significant correlation with clinicopathological features. This study for the first time analyzed the expression and prognosis of TPPP3 in head and neck squamous cell carcinoma, unexpectedly, in contrast to the expression in other tumors. We are as well the first to reveal the link between TPPP3 and immune infiltration. This study also has some shortcomings, such as we still need to perform in vitro and in vivo experiments on TPPP3 for cellular function studies as well as pathway studies.
NPC tissues from 57 confirmed and untreated NPC patients (median age: 45 years old; female:
Oncomine (
GEPIA (
TCGA is the world’s largest cancer database, which includes clinical data, genomic variation, mRNA expression, miRNA expression, methylation, and other data on various human cancers. The mRNA expression data of 70 HNSC and 13 adjacent control samples and relevant clinical data were downloaded from the TCGA database (
Gene Set Enrichment Analyses (GSEA) [
TIMER2.0 (
NPC tissues were fixed in formalin and embedded in paraffin. First,
GEO (
The mRNA expression between NPC and normal group was compared, respectively, using
All in all, the TPPP3 expression is significantly reduced in HNSC, and the low expression of TPPP3 is associated with CD8 + T cell and myeloid dendritic cell immune infiltration levels. Therefore, thus, TPPP3 can serve as a potential prognostic indicator for HNSC patients and may play an important role in immune cell infiltration.
Tubulin polymerization promoting protein family member 3
Gene expression profiling interactive analysis
Tumor immune estimation resource
Gene expression profiling interactive analysis
The Cancer Genome Atlas
The genotype-tissue expression
Head and neck squamous carcinoma
Microtubule
Bladder urothelial carcinoma
Breast invasive carcinoma
Kidney chromophobe
Kidney renal papillary cell carcinoma
Lung adenocarcinoma
Lung squamous cell carcinoma
Cholangiocarcinoma
Nasopharyngeal carcinoma
The World Health Organization
Overall survival
Disease-free survival.
The data used in this study are from open public databases, and how to obtain them has been explained in the manuscript.
The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
The authors declare no conflict of interest.
Z.Y. and W.M. did the conceptualization; Z.Y. and X.L. did the methodology; Z.Y., J.L., and Q.S. was assigned on the software; Z.Y., X.L., J.L., Q.S., Y.Q., Z.Z., L.Z., and W.M. did the validation; Z.Y did the formal analysis; W.M. was assigned on the resources; X.L. did the data curation; Z.Y. wrote the original draft preparation; Z.Y. and Q.S. did the writing, review, and editing; Z.Y. did the visualization; Y.Q. supervised; W.M. did the project administration; Z.Y. and W.M. was assigned on the funding acquisition. All authors have read and agreed to the published version of the manuscript.
This research was funded by the Natural Science Foundation of Guangxi, China, grant number 2018GXNSFAA281055, and the Guangxi Zhuang Autonomous Region Health Committee self-funded scientific research, grant number Z20190841.