High STMN1 Expression Is Associated with Tumor Differentiation and Metastasis in Clinical Patients with Pancreatic Cancer

Single-cell RNA sequencing identifies a novel proliferation cell type affecting clinical outcome of pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is an extremely deadly neoplasm, with only a 5-year survival rate of around 9%. The tumor and its microenvironment are highly heterogeneous, and it is still unknown which cell types influence patient outcomes.

Methods

We used single-cell RNA sequencing (scRNA-seq) and spatial transcriptome (ST) to identify differences in cell types. We then applied the scRNA-seq data to decompose the cell types in bulk RNA sequencing (bulk RNA-seq) data from the Cancer Genome Atlas (TCGA) cohort. We employed unbiased machine learning integration algorithms to develop a prognosis signature based on cell type makers. Lastly, we verified the differential expression of the key gene LY6D using immunohistochemistry and qRT-PCR.

Results

In this study, we identified a novel cell type with high proliferative capacity, Prol, enriched with cell cycle and mitosis genes. We observed that the proportion of Prol cells was significantly increased in PDAC, and Prol cells were associated with reduced overall survival (OS) and progression-free survival (PFS). Additionally, the marker genes of Prol cell type, identified from scRNA-seq data, were upregulated and associated with poor prognosis in the bulk RNA-seq data. We further confirmed that mutant KRAS and TP53 were associated with an increased abundance of Prol cells and that these cells were associated with an immunosuppressive and cold tumor microenvironment in PDAC. ST determined the spatial location of Prol cells. Additionally, patients with a lower proportion of Prol cells in PDAC may benefit more from immunotherapy and gemcitabine treatment. Furthermore, we employed unbiased machine learning integration algorithms to develop a Prol signature that can precisely quantify the abundance of Prol cells and accurately predict prognosis. Finally, we confirmed that the LY6D protein and mRNA expression were markedly higher in pancreatic cancer than in normal pancreatic tissue.

Conclusions

In summary, by integrating bulk RNA-seq and scRNA-seq, we identified a novel proliferative cell type, Prol, which influences the OS and PFS of PDAC patients.

Bioinformatics analysis of clinical significance of STMN1 gene in prognosis and immune infiltration in hepatocellular carcinoma

BACKGROUND

STMN1 (stathmin1), a member of the microtubule destabilizing protein family, is transcriptionally repressed by the functional tumor suppressor protein p53. STMN1 was first identified as a cellular phosphorylated protein overexpressed in leukemia in 1983. STMN1 was found to be upregulated in a variety of cancers, such as non-small cell lung cancer, breast cancer, and gastric cancer, and it can induce cell differentiation, proliferation, and migration in solid tumors and is associated with a poor clinical prognosis. However, the role and mechanism of STMN1 in hepatocellular carcinoma remain unclear.

AIM

To assess the expression of STMN1 gene in hepatocellular carcinoma and its relationship with the clinical characteristics and prognosis of patients, and to explore the molecular mechanism of STMN1 gene in this malignancy.

METHODS

Clinical information and high-throughput RNA-sequencing data of hepatocellular carcinoma patients were downloaded from The Cancer Genome Atlas (https://portal.gdc.cancer.gov, TCGA) database. R (v3.6.2) software was used to analyze the expression of STMN1 gene in hepatocellular carcinoma tissues, and its relationship with clinical characteristics of patients was analyzed. Univariate and multivariate Cox regression models were used to analyze the prognostic value of STMN1 in hepatocellular carcinoma. Gene enrichment analysis was used to analyze STMN1 expression-related pathway mechanisms. ssGSEA method was used to analyze the infiltration of 24 immune cell types in tumors, and to explore the relationship between STMN1 and immune cells.

RESULTS

STMN1 was highly expressed in tumor tissues (P < 0.001). The diagnostic value of STMN1 was assessed by ROC curve analysis, and the area under the ROC curve (AUC) was 0.971. The predictive ability of STMN1 had high accuracy. Chi-square test or Fisher exact test revealed that STMN1 expression was significantly associated with overall survival rate (P = 0.013), T stage (P = 0.002), TNM stage (P = 0.008), age (P = 0.006), and tumor grade (P < 0.001). The overall survival rate, progression-free survival rate, and disease-specific survival rate of the high STMN1 gene expression group were lower than those of the low expression group (P < 0.01). Cox regression analysis showed that the high expression of STMN1 was an independent risk factor for the prognosis of patients with hepatocellular carcinoma (hazard ratio = 1.808, 95% confidence interval: 1.288-2.234, P = 0.014). GSEA analysis showed that STMN1 gene in hepatocellular carcinoma is mainly involved in cell cycle, oocyte meiosis, T cell receptor signaling pathway, natural killer cell-mediated cytotoxicity, and spliceosome. Immune infiltration analysis showed that STMN1 expression was positively correlated with helper T cells 2, follicular helper T cells, and helper T cells, and was negatively correlated with neutrophils, helper T cells 17, and dendritic cells.

CONCLUSION

The expression of STMN1 gene is up-regulated in hepato-cellular carcinoma, which is associated with a poor prognosis of patients. It is an independent prognostic factor for hepatocellular carcinoma patients and is expected to become a potential molecular marker of this malignancy.

Stathmin 1 is a biomarker for diagnosis of microvascular invasion to predict prognosis of early hepatocellular carcinoma

Microvascular invasion (MVI) is presently evaluated as a high-risk factor to be directly relative to postoperative prognosis of hepatocellular carcinoma (HCC). Up to now, diagnosis of MVI mainly depends on the postoperative pathological analyses with H&E staining assay, based on numbers and distribution characteristics of MVI to classify the risk levels of MVI. However, such pathological analyses lack the specificity to discriminate MVI in HCC specimens, especially in complicated pathological tissues. In addition, the efficiency to precisely define stages of MVI is not satisfied. Thus, any biomarker for both conforming diagnosis of MVI and staging its levels will efficiently and effectively promote the prediction of early postoperative recurrence and metastasis for HCC. Through bioinformatics analysis and clinical sample verification, we discovered that Stathmin 1 (STMN1) gene was significantly up-regulated at the locations of MVI. Combining STMN1 immunostaining with classic H&E staining assays, we established a new protocol for MVI pathological diagnosis. Next, we found that the degrees of MVI risk could be graded according to expression levels of STMN1 for prognosis prediction on recurrence rates and overall survival in early HCC patients. STMN1 affected epithelial-mesenchymal transformation (EMT) of HCC cells by regulating the dynamic balance of microtubules through signaling of “STMN1-Microtubule-EMT” axis. Inhibition of STMN1 expression in HCC cells reduced their lung metastatic ability in recipients of mouse model, suggesting that STMN1 also could be a potential therapeutic target for inhibiting HCC metastasis. Therefore, we conclude that STMN1 has potentials for clinical applications as a biomarker for both pathological diagnosis and prognostic prediction, as well as a therapeutic target for HCC.

PTEN loss promotes oncogenic function of STMN1 via PI3K/AKT pathway in lung cancer

Among all cancer types, lung cancer has already become the leading cause of cancer-related death around the world. The molecular mechanism understanding this development is still needed to be improved to treat lung cancer. Stathmin (STMN1) was initially identified as a cytoplasmic protein phosphorylated responding to cell signal and controlled cell physiological processes. The dysregulation of STMN1 is found in various kinds of tumors. However, the molecular mechanism of STMN1 regulating lung cancer is still unclear. Here, we found that STMN1 was overexpressed in lung cancer tissues and associated with worse survival rates of lung cancer patients. Inhibition of STMN1 suppressed lung cancer cell growth, migration and invasion, and promoted drug sensitivity. Moreover, PTEN loss promoted STMN1 expression via PI3K/AKT pathway. PTEN loss ameliorated the inhibition of cell growth, migration and invasion, and drug sensitivity induced by STMN1 knockdown in lung cancer. The high expression of STMN1 was negatively correlated with the low expression of PTEN in lung cancer specimens. Overall, our work demonstrated that PTEN regulated the oncogenic function of STMN1 in lung cancer.

A Glycolysis-Related Five-Gene Signature Predicts Biochemical Recurrence-Free Survival in Patients With Prostate Adenocarcinoma

Prostate cancer (PCa) is one of the most frequently diagnosed cancers in males worldwide. Approximately 25% of all patients experience biochemical recurrence (BCR) after radical prostatectomy (RP) and BCR indicates increased risk for metastasis and castration resistance. PCa patients with highly glycolytic tumors have a worse prognosis. Thus, this study aimed to explore glycolysis-based predictive biomarkers for BCR. Expression data and clinical information of PCa samples were retrieved from three publicly available datasets. One from The Cancer Genome Atlas (TCGA) dataset was used as the training cohort, and two from the Gene Expression Omnibus (GEO) dataset (GSE54460 and GSE70769) were used as validation cohorts. Using the training cohort, univariate Cox regression survival analysis, robust likelihood-based survival model, and stepwise multiply Cox analysis were sequentially applied to explore predictive glycolysis-related candidates. A five-gene risk score was then constructed based on the Cox coefficient as the following: (−0.8367*GYS2) + (0.3448*STMN1) + (0.3595*PPFIA4) + (−0.1940*KDELR3) + (0.4779*ABCB6). Receiver operating characteristic curve (ROC) analysis was used to identify the optimal cut-off point, and patients were divided into low risk and high risk groups. Kaplan–Meier analysis revealed that high risk group had significantly shorter BCR free survival time as compared with that in low risk group in training and validation cohorts. In conclusion, our data support the glycolysis-based five-gene signature as a novel and robust signature for predicting BCR of PCa patients.

A glycolysis-related gene expression signature in predicting recurrence of breast cancer

Metabolic change is the hallmark of cancer. In the present study, we aimed to develop a glycolysis-related gene signature to predict the prognosis of breast cancer patients. Gene expression profiles and clinical data of breast cancer patients were obtained from the GEO database. A four-gene based signature (ALDH2, PRKACB, STMN1 and ZNF292) was developed to separate patients into high-risk and low-risk groups. Patients in the low-risk group had significantly better prognosis than those in the high-risk group. Time-dependent ROC analysis demonstrated that the glycolysis-related gene signature had excellent prognostic accuracy. We further confirmed the expression of the four prognostic genes in breast cancer and paracancerous tissue samples using qRT-PCR analysis. Expression level of PRKACB was higher in paracancerous tissues, while STMN1 and ZNF292 were overexpressed in tumor samples, no significant difference was observed in ALDH2 expression level. Global proteome data of 105 TCGA breast cancer samples obtained from the Clinical Proteomic Tumor Analysis Consortium (CPTAC) were used to evaluate the prognostic value in protein levels. Consistently, high expression level of PRKACB protein was associated with favorable prognosis, while high ZNF292 and STMN1 protein expression levels indicated poor prognosis. The glycolysis-related gene signature might provide an effective prognostic predictor and a new insight for individualize management of breast cancer patients.

Role of microRNA/Epithelial-to-Mesenchymal Transition Axis in the Metastasis of Bladder Cancer

Bladder cancer (BC) is the 11th most common diagnosed cancer, and a number of factors including environmental and genetic ones participate in BC development. Metastasis of BC cells into neighboring and distant tissues significantly reduces overall survival of patients with this life-threatening disorder. Recently, studies have focused on revealing molecular pathways involved in metastasis of BC cells, and in this review, we focus on microRNAs (miRNAs) and their regulatory effect on epithelial-to-mesenchymal transition (EMT) mechanisms that can regulate metastasis. EMT is a vital process for migration of BC cells, and inhibition of this mechanism restricts invasion of BC cells. MiRNAs are endogenous non-coding RNAs with 19-24 nucleotides capable of regulating different cellular events, and EMT is one of them. In BC cells, miRNAs are able to both induce and/or inhibit EMT. For regulation of EMT, miRNAs affect different molecular pathways such as transforming growth factor-beta (TGF-β), Snail, Slug, ZEB1/2, CD44, NSBP1, which are, discussed in detail this review. Besides, miRNA/EMT axis can also be regulated by upstream mediators such as lncRNAs, circRNAs and targeted by diverse anti-tumor agents. These topics are also discussed here to reveal diverse molecular pathways involved in migration of BC cells and strategies to target them to develop effective therapeutics.

STMN1 and MKI67 Are Upregulated in Uterine Leiomyosarcoma and Are Potential Biomarkers for its Diagnosis

Background

The aim of this study was to investigate STMN1 and MKI67 expression in uterine leiomyosarcoma and their potential roles as biomarkers for diagnosis.

Material/Methods

The expression of STMN1 and MKI67 mRNA in uterine leiomyosarcoma were investigated in TCGA database. The overall survival (OS) and disease-free survival (DFS) were compared between high and low expression groups. Seventy-two patients who received hysterectomy were included and divided into 4 groups: uterine normal smooth muscle tissue (UNSM=30), uterine leiomyoma (UL=30), uterine cellular leiomyoma (UCL=24), and uterine leiomyosarcoma (ULS=18). The STMN1 and MKI67 protein expression of the 4 groups were examined by immunohistochemistry (IHC) assay.

Results

The expression level of STMN1 mRNA in cancer tissue was significantly higher than those of normal uterine smooth muscle tissue. The high and low expression of STMN1 and mki67 gene mRNA was not related to the patients’ OS and DFS (P>0.05). The positive rate of STMN1 protein in uterine leiomyosarcoma was 100.00%, which was significantly higher than that of the other 3 groups (χ²=11.72, P=0.008). And the positive rate of KIM67 protein in uterine leiomyosarcoma was 77.78%, which was also significantly higher than that of the other 3 groups (χ²=48.89, P=0.000). The diagnostic sensitivity and specificity were 77.78%, 90.74% for STMN1 combined MKI67 with the positive predictive value and negative predictive value of 73.68% and 92.45%, respectively.

Conclusions

STMN1 and MKI67 were upregulated in uterine leiomyosarcoma and act as potential biomarkers for uterine leiomyosarcoma diagnosis.

Molecular targets regulating invasion and metastasis of pancreatic cancer

Pancreatic cancer is one of the most malignant tumors of the digestive system. Invasion and metastasis are important biological characteristics of pancreatic cancer and contribute greatly to the poor prognosis of the patients. Many lines of evidence have recently revealed that many molecules, genes and proteins regulate the invasion and metastasis of pancreatic cancer cells. Therefore, exploration and a deep understanding of the molecular mechanism accounting for the invasion and metastasis of pancreatic cancer can help find novel pancreatic cancer biomarkers, improve early diagnosis, develop novel and effective treatment strategies, and predict the prognosis. This review summarizes the latest progress in the research of molecular targets for pancreatic cancer and the mechanisms by which they participate in the invasion and metastasis of this aggressive malignancy.