Restoration of BRAK / CXCL14 gene expression by gefitinib is associated with antitumor efficacy of the drug in head and neck squamous cell carcinoma

Zou

Molecular Medicine Reports

et al. 2014

Abstract. Chemokines are important in the proliferation and metastasis of tumors. CXCL14 is a member of the CXCL chemokine family and exhibits various expression patterns in different types of tumor, even those tumors that occur in the same type of tissue. The expression of CXCL14 and its clinical significance in colorectal carcinoma are unclear. In the present study, the expression levels of CXCL14 in colorectal carcinoma and adjacent normal tissues were detected using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Kaplan-Meier survival curves and the Cox regression model were applied to evaluate the clinical significance of the expression levels of CXCL14 in colorectal carcinoma compared with those in normal tissues. To investigate the effects at a cellular level, a replication-defective lentivirus overexpressing CXCL14 was constructed and transfected into HT29 colorectal carcinoma cells. The effect of CXCL14 on the proliferation of colorectal carcinoma cells and the change in cell cycle distributions were investigated using a cell counting kit-8 assay and flow cytometry, respectively. Results of the current study indicated that the expression levels of CXCL14 mRNA and protein in colorectal carcinoma were markedly reduced compared with levels in normal tissues (P<0.05). The clinical correlation analysis suggested that downregulation of CXCL14 expression in tumors was associated with lymph metastasis, tumor location, and clinicopathological stage (P<0.05). Kaplan-Meier survival analysis revealed that downregulation of CXCL14 expression was correlated with a poor prognosis (P<0.01). Overexpression of CXCL14 by lentiviral transfection produced an inhibitory effect on cell proliferation by arresting the cell cycle in the G 1 stage. The data of the current study suggest that CXCL14 may be involved in the development and progression of colorectal carcinoma, and may act directly as a potential cancer suppressor gene. The level of CXCL14 expression may be a valuable adjuvant parameter in predicting the prognosis of colorectal carcinoma and may be a potential therapeutic target.

Section: Discussionsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Expression and effect of CXCL14 in colorectal carcinoma

Zou

Molecular Medicine Reports

et al. 2014

“…Furthermore, introduction of small interference RNA expression-vector for BRAK into HSC-3 cells reduced both the expression levels of BRAK in HSC-3 cells and the antitumor efficacy of gefitinib in vivo. These data also indicate that BRAK expression is essential for tumor suppression in vivo (14). The same or a higher level of natural killer (NK) cell activity is present in SCID mice compared with wild-type C.B-17 mice (26); and BRAK/CXCL14 stimulates the migration of activated NK cells but does not affect the proliferation or cytotoxic activity of normal NK cells (21), suggesting that NK cells are partially responsible for BRAK/CXCL14-dependent tumor suppression and that the co-presence of a NK cell activator(s) is essential for tumor suppression.…”

mentioning

confidence: 67%

BRAK/CXCL14 expression in oral carcinoma cells completely suppresses tumor cell xenografts in SCID mouse

et al. 2009

Self Cite

SCID mice are a model of human severe combined immunodeficiency disease and are deficient in B cell function in addition to T cell function. Tumors from other species are easily transplanted into SCID mice and will grow without being rejected. We previously reported that the chemokine BRAK/CXCL14 is expressed in normal cells but its expression is down regulated in an in vitro cancer progression model, suggesting that it has the potential for antitumor activity. Here we report that the growth of BRAK/CXCL14 expression vector-transfected oral cancer cells was completely (100%) suppressed in SCID mouse xenografts even though mock-vector introduced control tumor cells grew well with 100% of animals developing tumors. In addition, suppression of xenografts was much faster and the rate was much higher in SCID mice than in T cell functiondeficient nude mice. These data indicate the possibility that BRAK expression inhibits tumor cell establishment by regulating interactions between tumor stem cells and NK cells and/or suppressing formation of tumor microvessels.Tumors develop in multiple steps (6,19,25), and tumor progression is dependent on the balance of the expression between tumor progression-promoting and -suppressing genes being in favor of the former at each step (1, 2). In order to prevent tumor progression, many investigators have searched for molecules that are over-expressed during tumor progression as target molecules for therapeutic drugs and have tried to prevent tumor progression by inhibiting these tumor-promoting molecules. However, drugs for many of the target molecules were not successful for clinical applications owing to the serious side effects of these drugs, which is not surprising because these target molecules are also important for normal development and maintenance of tissues and for homeostasis of our body (16,22).On the other hand, activation of presumptive tumor suppressor(s) or inhibition of their down-regulation may be much more promising for the prevention of tumor progression without significant side effects, because these molecules are supposedly present abundantly in normal tissues. In the course of our study to find an endogenous tumor suppressor(s) for oral cancers (OC), we searched for molecules down-regulated in OC cells when the cells were treated with epidermal growth factor (EGF), whose receptor is frequently overactivated in OC. The expression of BRAK, which is also known as CXC chemokine ligand 14 (CXCL14), was down-regulated significantly by the treatment of OC cells with EGF as observed by cDNA microarray analysis followed by reverse-transcriptase polymerase chain reaction analysis. In order to investigate whether BRAK/CXCL14 have a tumor-suppressing effect in vivo, we prepared BRAK/CXCL14-expression vector-transfected tongue tumor-derived cells (HSC-3 BRAK) and cloned them. No difference in the growth rates of these cells was observed in vitro

“…The expression is negatively regulated by the binding of epidermal growth factor (EGF) to its receptor (16); and when HNSCC cells are treated with gefitinib, an epidermal growth factor tyrosine kinase inhibitor, the expression of BRAK/CXCL14 protein increases under culture conditions (15). Interestingly, the oral administration of gefitinib significantly (P < 0.001) reduces the growth of tumor xenografts of 3 HN-SCC cell lines (HSC-2, HSC-3 and HSC-4) in female athymic nude mice, which reduction is accompanied by an increase in BRAK expression specifically in the tumor tissue; this tumor-suppressing effect of the drug is not observed in the case of BRAK non-expressing cells (15). Furthermore, the introduction of a vector expressing short hairpin RNA against BRAK reduces both the expression level of BRAK/CXCL14 in HSC-3 cells and the antitumor efficacy of gefitinib in vivo (15).…”

Section: Effects Of Expression Of Brak Protein By Tet-on Brak Hsc-2 Cmentioning

confidence: 99%

Expression of a chemokine BRAK/CXCL14 in oral floor carcinoma cells reduces the settlement rate of the cells and suppresses their proliferation in vivo

et al. 2010

Self Cite

We reported previously that the forced expression of the chemokine BRAK/CXCL14 in head and neck squamous cell carcinoma cells decreased the rate of tumor formation and size of tumor xenografts in athymic nude mice and SCID mice. In order to clarify the expression of BRAK/ CXCL14 affected either the settlement of carcinoma cells in host tissues in vivo or proliferation of the colonized carcinoma cells or both, we prepared oral floor carcinoma-derived HSC-2 cells in which BRAK/CXCL14 expression was induced upon doxycycline treatment. Then 30 nude mice were separated into 3 groups composed of 10 mice per group: Group I, the control, in which the engineered cells were directly xenografted onto the back of the mice; Group II, the cells were xenografted and then the mice were treated with doxycycline; and Group III, the cells were pretreated with doxycycline during culture, and the host mice were also treated with the drug before and after xenografting. The effects of BRAK/CXCL14 expression were examined by measuring the tumor size. The order of the size of tumor xenografts was Group I > II > III, even though the growth rate of the engineered cells was the same whether or not the cells were cultured in the presence of the drug. In addition, the size of tumors was significantly down-regulated after xenografting the doxycycline-pretreated cells in Group III. These data indicate that BRAK/CXCL14 expression in oral floor carcinoma cells reduced both the rate of settlement and the proliferation of the cells in vivo after settlement of the cells.Chemokines are a family of small (8-14 kDa) mostly basic, structurally related chemotactic cytokines, and they function as leukocyte subtype-selective chemo-attractants (29,30). A complex network of chemokines and their receptors influences the development of primary tumors and metastasis (2,19,29). First detected in breast and kidney, BRAK is also called CXC chemokine ligand 14 (CXCL14), and was reported to induce B cell, monocyte (26), and dendritic cell infiltration into normal and tumour tissues (25) and to inhibit angiogenesis (23). Generally, BRAK/CXCL14 is expressed universally and abundantly in normal tissues but is absent from or expressed only in a very small amount in cancerous tissues in vivo and in carcinoma cells in culture, including head and neck squamous cell carcinoma (HNSCC) cells (7,9,11,16,23). On the other hand, heightened BRAK/CXCL14 expression has been reported to occur in adenocarcinomas such as prostate (22), breast cancer (1) and pancreatic cancer cells (28). These data suggest that the effects of BRAK/CXCL14 on the development and progression of cancer might be quite different between HN-