Comprehensive analysis of CXCR family members in lung adenocarcinoma with prognostic values.

BACKGROUND: The expression profiles and molecular mechanisms of CXC chemokine receptors (CXCRs) in Lung adenocarcinoma (LUAD) have been extensively explored. However, the comprehensive prognostic values of CXCR members in LUAD have not yet been clearly identified. METHODS: Multiple available datasets, including Oncomine datasets, the cancer genome atlas (TCGA), HPA platform, GeneMANIA platform, DAVID platform and the tumor immune estimation resource (TIMER) were used to detect the expression of CXCRs in LUAD, as well as elucidate the significance and value of novel CXCRs-associated genes and signaling pathways in LUAD. RESULTS: The mRNA and/or protein expression of CXCR1, CXCR2, CXCR3, CXCR4, CXCR5 and CXCR6 displayed predominantly decreased in LUAD tissues as compared to normal tissues. On the contrary, compared with the normal tissues, the expression of CXCR7 was significantly increased in LUAD tissues. Subsequently, we constructed a network including CXCR family members and their 20 related genes, and the related GO functions assay showed that CXCRs connected with these genes participated in the process of LUAD through several signal pathways including Chemokine signaling pathway, Cytokine-cytokine receptor interaction and Neuroactive ligand-receptor interaction. TCGA and Timer platform revealed that the mRNA expression of CXCR family members was significantly related to individual cancer stages, cancer subtypes, patient's gender and the immune infiltration level. Finally, survival analysis showed that low mRNA expression levels of CXCR2 (HR = 0.661, and Log-rank P = 1.90e-02), CXCR3 (HR = 0.674, and Log-rank P = 1.00e-02), CXCR4 (HR = 0.65, and Log-rank P = 5.01e-03), CXCR5 (HR = 0.608, and Log-rank P = 4.80e-03) and CXCR6 (HR = 0.622, and Log-rank P = 1.85e-03) were significantly associated with shorter overall survival (OS), whereas high CXCR7 mRNA expression (HR = 1.604, and Log-rank P = 4.27e-03) was extremely related with shorter OS in patients. CONCLUSION: Our findings from public databases provided a unique insight into expression characteristics and prognostic values of CXCR members in LUAD, which would be benefit for the understanding of pathogenesis, diagnosis, prognosis prediction and targeted treatment in LUAD.

Clinical significance and biological functions of chemokine CXCL3 in head and neck squamous cell carcinoma.

CXCL3 plays extensive roles in tumorigenesis in various types of human cancers through its roles in tumor cell differentiation, invasion, and migration. However, the mechanisms of CXCL3 in head and neck squamous cell carcinoma (HNSCC) remain unclear. In our study, multiple databases were used to explore the expression level, prognostic value, and related mechanisms of CXCL3 in human HNSCC through bioinformatic methods. We also performed further experiments in vivo and in vitro to evaluate the expression of CXCL3 in a human head and neck tissue microarray and the underlying effect mechanisms of CXCL3 on the tumor biology of HNSCC tumor cells. The result showed that the expression level of CXCL3 in patients with HNSCC was significantly higher as compared with that in normal tissues (P<0.05). Kaplan-Meier survival analysis demonstrated that patients with high CXCL3 expression had a lower overall survival rate (P=0.038). CXCL3 was further identified as an independent prognostic factor for HNSCC patients by Cox regression analysis, and GSEA exhibited that several signaling pathways including Apoptosis, Toll-like receptor, Nod-like receptor, Jak-STAT, and MAPK signaling pathways may be involved in the tumorigenesis of HNSCC. CAL27 cells overexpressing or HNSCC cells treated with exogenous CXCL3 exhibited enhanced cell malignant behaviors, whereas down-regulating CXCL3 expression resulted in decreased malignant behaviors in HSC4 cells. In addition, CXCL3 may affect the expression of several genes, including ERK1/2, Bcl-2, Bax, STAT3, and NF-κB. In summary, our bioinformatics and experiment findings effectively suggest the information of CXCL3 expression, roles, and the potential regulatory network in HNSCC.

CXCL3 overexpression affects the malignant behavior of oral squamous cell carcinoma cells via the MAPK signaling pathway.

OBJECTIVE: CXCL3, a member of the chemokine family, plays a key role in angiogenesis, tumorigenesis, and cell invasion and migration. However, the role of CXCL3 in oral squamous cell carcinoma (OSCC) remains unclear. The purpose of this study is to explore the expression of CXCL3 in OSCC and to explore the role of CXCL3 in human OSCC HSC-4 cells and its molecular mechanism. METHODS: The expression of CXCL3 in human OSCC tissues was assessed using immunohistochemistry and The Cancer Genome Atlas (TCGA) database. In vivo and in vitro experiments investigated the effects of CXCL3 on the proliferation, migration, and invasion of OSCC cells. RESULTS: The expression of CXCL3 in tumors is higher than that in normal tissues and is closely related to stage and lymph node metastasis. In vitro experiments showed that the proliferation and migration ability of HSC-4 cells treated with exogenous recombinant human CXCL3 and HSC-4 cells overexpressing CXCL3 were enhanced. Experiments on xenografts in nude mice showed that overexpression of CXCL3 promotes tumor growth in vivo. GSEA showed that patients with high expression of CXCL3 have varying degrees of enrichment in cytokine-cytokine receptor interaction, apoptosis, Jak-STAT signaling pathway, and MAPK signaling pathway. Subsequent mechanism studies showed that the use of ERK1/2 blocker PD98059 can attenuate the proliferation and migration effects induced by CXCL3. CONCLUSION: CXCL3 is involved in the occurrence of OSCC and may become a potential therapeutic target.

USP18-deficiency in cervical carcinoma is crucial for the malignant behavior of tumor cells in an ERK signal-dependent manner.

Ubiquitin-specific peptidase (USP)18 belongs to the USP family, and is involved in cleaving and removing ubiquitin or ubiquitin-like molecules from their target molecules. Recently, increasing evidence has suggested that USP18 is constitutively expressed in different types of human tumors, and ectopic expression or downregulation of USP18 expression may contribute to tumorigenesis. However, the role of USP18 in uterine cervical cancer (UCC) remains unclear. Thus, the present study aimed to investigate USP18 expression in a human tissue microarray constructed using UCC and non-cancer cervical tissues, and to determine the potential role and molecular mechanism by which USP18 is implicated in the tumor biology of human UCC HeLa cells. Microarray analysis demonstrated that USP18 protein expression was downregulated in tumor tissues compared with in normal tissues. In addition, in vitro analysis revealed that USP18-knockdown markedly promoted the proliferation, colony formation, migration and aggressiveness of HeLa cells. Mechanistic analysis demonstrated that USP18-knockdown increased the levels of Bcl-2, STAT3 and phosphorylated-ERK in HeLa cells. Notably, USP18 silencing-induced malignant phenotypes were interrupted following exogenous administration of the ERK1/2 inhibitor PD98059. Overall, the results of the present study suggested that USP18 may be a potent inhibitor involved in UCC tumor-associated biological behaviors, which are associated with the ERK signaling pathway.