Over-expression of Activated Signal Transducer and Activator of Transcription 3 Predicts Poor Prognosis in Upper Tract Urothelial Carcinoma

Prognostic value of key genes of the JAK-STAT signaling pathway in patients with cutaneous melanoma

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway is involved in cell immunity, division and death, as well as in tumor formation. The expression of key genes in the JAK-STAT signaling pathway in different types of cancer serves different roles. However, few reports are available on the prognostic value of the genes of the JAK-STAT signaling pathway in skin cutaneous melanoma (SKCM). The potential prognostic value of gene expression in the JAK-STAT signaling pathway in patients with SKCM was analyzed in the present study using data obtained from The Cancer Genome Atlas. To predict the potential functions and mechanisms of these genes in SKCM, gene set enrichment analysis (GSEA) and bioinformatics analysis were performed. A nomogram model including gene expression level and high risk factors was used to predict the risk level of prognostic. High expression levels of STAT1, STAT3, STAT4 and STAT5B, and low expression levels of STAT6 were associated with favorable prognosis [adjusted P<0.001; hazard ratio (HR), 0.595; 95% confidence interval (CI), 0.455–0.778; adjusted P=0.018; HR, 0.725; 95% CI, 0.555–0.947; adjusted P<0.001; HR, 0.590; 95% CI, 0.450–0.773; adjusted P=0.007; HR, 0.690; 95% CI, 0.526–0.940; and adjusted P=0.026; HR, 0.737, 95% CI, 0.563–0.964, respectively]. GSEA results demonstrated that these genes were involved in cell differentiation, invasion, adhesion, migration, cycle, colony formation and mitogen-activated protein kinase signaling. The combination of genes with favorable prognosis had a better effect on the overall survival (univariate survival analysis, P<0.05). The results of the present study suggest that STAT1, STAT3, STAT4, STAT5B and STAT6 gene expression may be used as a potential prognostic biomarker of SKCM, and the combined outcomes may exhibit a stronger interaction and higher survival time for SKCM.

MicroRNA-145 suppresses cell migration and invasion in upper tract urothelial carcinoma by targeting ARF6

ADP-ribosylation factor 6 (ARF6) is a well-studied protein that is involved in multiple biological functions including cell migration and invasion. The mechanism by which ARF6 regulates the migration and invasion of upper tract urothelial carcinoma (UTUC) is still unknown. MiR-145-5p is a tumor suppressor microRNA, which is downregulated in several cancer types. We aimed to elucidate the molecular mechanism underlying the regulation of ARF6 by miR-145-5p in UTUC. ARF6 expression was observed to be higher in UTUC tissues than paired adjacent normal tissues. A reverse correlation between ARF6 and miR-145-5p was found in UTUC tissues. MiR-145-5p inhibited ARF6 expression by directly targeting its 3'-UTR. The functional studies indicated that ARF6 expression reversed the miR-145-5p-reduced tumor cell migration and invasion. Notably, miR-145-5p reduced MMP2, N-cadherin, FAK and MMP7, and elevated E-cadherin protein levels in vitro; however, the above effects were reversed by ARF6. Further, the expression of epithelial-to-mesenchymal transition (EMT) markers and cell invasion was suppressed by knocking down MMP7 in UTUC cells. These findings suggest that miR-145-5p may suppress UTUC cell motility and invasion by targeting ARF6/MMP7 through EMT.

CSF-1 Overexpression Predicts Poor Prognosis in Upper Tract Urothelial Carcinomas

Background

Colony-stimulating factor-1 (CSF-1) is a homodimeric glycoprotein. The main role of CSF-1 is as a hematopoietic growth factor that modulates proliferation, differentiation, and survival of macrophages. Moreover, CSF-1 has also been reported to be aberrantly expressed in several human cancers. However, the precise role of CSF-1 in upper tract urothelial carcinomas (UTUC) has not been studied. In this research, we examined the clinical significance of CSF-1 expression in UTUC.

Materials and Methods

One hundred twelve cancer tissue samples of UTUC from patients were included in this study, and the other cohort of 35 UTUC were paired cancer-adjacent normal samples. CSF-1 expression was evaluated by immunohistochemistry, and the association of CSF-1 expression with different clinicopathological variables was analyzed.

Results

CSF-1 expression was higher in UTUC than in the normal urothelium (P = 0.005). The CSF-1 expression was primarily localized in the nucleus and was significantly correlated with tumor size (P = 0.04) and patients who had a high stage (P < 0.001), distant metastasis (P = 0.006), recurrence (P = 0.003), and cancer death (P = 0.005). High CSF-1 expression was correlated with poor disease-free survival (P = 0.008) and cancer-specific survival (P = 0.001). Our results also used univariate and multivariable analyses, which found that high CSF-1 expression was an independent predictor of poor disease-free survival (hazard ratio = 2.56; P = 0.007) and cancer-specific survival (hazard ratio = 5.14; P = 0.022).

Conclusions

Our findings indicate that the expression of CSF-1 is a potential prognostic marker for predicting patient survival and recurrence in UTUC.

Negative regulators of STAT3 signaling pathway in cancers

STAT3 is the most ubiquitous member of the STAT family and involved in many biological processes, such as cell proliferation, differentiation, and apoptosis. Mounting evidence has revealed that STAT3 is aberrantly activated in many malignant tumors and plays a critical role in cancer progression. STAT3 is usually regarded as an effective molecular target for cancer treatment, and abolishing the STAT3 activity may diminish tumor growth and metastasis. Recent studies have shown that negative regulators of STAT3 signaling such as PIAS, SOCS, and PTP, can effectively retard tumor progression. However, PIAS, SOCS, and PTP have also been reported to correlate with tumor malignancy, and their biological function in tumorigenesis and antitumor therapy are somewhat controversial. In this review, we summarize actual knowledge on the negative regulators of STAT3 in tumors, and focus on the potential role of PIAS, SOCS, and PTP in cancer treatment. Furthermore, we also outline the STAT3 inhibitors that have entered clinical trials. Targeting STAT3 seems to be a promising strategy in cancer therapy.

The special stemness functions of Tbx3 in stem cells and cancer development

The T-box factors belong to an ancient protein family, which comprises a cluster of evolutionarily-conserved transcription factors that regulate gene expression and that are crucial to embryonic development. T-box transcription factor 3 (Tbx3) is a member of this family, is expressed in some tissues, and is a key regulator in many critical organs, including the heart, mammary gland, and limbs. Overexpression of Tbx3 is associated with a number of cancers, including head and neck squamous cell carcinoma, gastric, breast, ovary, cervical, pancreatic, bladder and liver cancers, as well as melanoma. Tbx3 promotes tumor development by modulating cell proliferation, tumor formation, metastasis, cell survival and drug resistance. Moreover, there is strong evidence that Tbx3 regulates stem cell maintenance by controlling stem cell self-renewal and differentiation. Verification of the upstream regulatory factors and potential molecular mechanism of Tbx3, being able to explain the function of Tbx3 in carcinogenic effects and stem cell maintenance, will make a valuable contribution to stem cell and cancer research. This review provides an insight into the current research on Tbx3 and explores the significance of Tbx3 in stem cells and tumorigenesis.