CDH4 inhibits ferroptosis in oral squamous cell carcinoma cells.

BACKGROUND: The cadherin-4 gene (CDH4), a member of the cadherin family genes, encodes R-cadherin (R-cad); however, the function of this gene in different types of cancer remains controversial. The function of CDH4 in OSCC (oral squamous cell carcinoma) is unknown. MATERIALS AND METHODS: We use the Cancer Genome Atlas (TCGA) database to find the expression of CDH4 in OSCC is more than normal tissue. Our tissue samples also confirmed that CDH4 gene was highly expressed in OSCC. The related cell function assay detected that CDH4 promotes the ability of cell proliferation, migration, self-renewal and invasion. Cell staining experiment confirmed that the change of CDH4 expression would change the cell mortality. The western blot of GPX4 (glutathione-dependent peroxidase-4), GSH (reduced glutathione) test assay and MDA(Malondialdehyde) test assay show that the expression of CDH4 may resist the sensitivity of ferropotosis in OSCC. RESULTS: CDH4 was upregulated in OSCC samples and was correlation with poor survival of patients. High expression of CDH4 effectively promotes the proliferation, mobility of OSCC cells and reduce the sensitivity of OSCC cells to ferroptosis. CDH4 is positively correlated with EMT pathway genes, negatively correlated with fatty acid metabolism pathway genes and peroxisome pathway genes, and positively correlated with ferroptosis suppressor genes in OSCC. CONCLUSIONS: These results indicate that CDH4 may play a positive role in tumor progression and resistance ferroptosis and may be a potential therapeutic target for OSCC.

High expression of Notch2 drives tongue squamous cell carcinoma carcinogenesis.

Tongue squamous cell carcinoma (TSCC) is one of the most common cancers in the oral cavity. Notch signaling is frequently dysregulated in cancer. However, the role of Notch2 in TSCC is not well understood. The aim of this study was to investigate the effect of abnormal expression of Notch2 in TSCC. The expression of Notch2 was tested in 47 pairs of tissues from tongue cancer and normal samples by using immunohistochemical staining. Tongue cancer cells were transfected with siRNA or plasmid. The proliferation of the cells was tested by the CCK8 assay and colony formation assay. Subcutaneous tumor model was established to observe tumor growth. Transwell assay was used to detect the changes of cell migration and invasion ability. A humanized anti-Notch2 antibody was used to TSCC cells. We found that Notch2 was upregulated in tongue carcinoma tissues. Knocking down the expression of Notch2 by siRNA in the TSCC cell lines decreased proliferation ability both in vitro and in vivo. In addition, migration and invasion abilities were inhibited by knockdown of Notch2 in the TSCC cells. However, overexpression of Notch2 increased tongue cancer cell proliferation, invasion and migration. The humanized anti-Notch2 antibody inhibited TSCC cell growth. The results indicated that Notch2 is an oncogene in tongue squamous cell carcinoma and may become the target of a new approach for treating TSCC.

The oncogenic effects of HES1 on salivary adenoid cystic carcinoma cell growth and metastasis.

BACKGROUND: Our previous study demonstrated a close relationship between NOTCH signaling pathway and salivary adenoid cystic carcinoma (SACC). HES1 is a well-known target gene of NOTCH signaling pathway. The purpose of the present study was to further explore the molecular mechanism of HES1 in SACC. METHODS: Comparative transcriptome analyses by RNA-Sequencing (RNA-Seq) were employed to reveal NOTCH1 downstream gene in SACC cells. Immunohistochemical staining was used to detect the expression of HES1 in clinical samples. After HES1-siRNA transfected into SACC LM cells, the cell proliferation and cell apoptosis were tested by suitable methods; animal model was established to detect the change of growth ability of tumor. Transwell and wound healing assays were used to evaluate cell metastasis and invasion. RESULTS: We found that HES1 was strongly linked to NOTCH signaling pathway in SACC cells. The immunohistochemical results implied the high expression of HES1 in cancerous tissues. The growth of SACC LM cells transfected with HES1-siRNAs was significantly suppressed in vitro and tumorigenicity in vivo by inducing cell apoptosis. After HES1 expression was silenced, the SACC LM cell metastasis and invasion ability was suppressed. CONCLUSIONS: The results of this study demonstrate that HES1 is a specific downstream gene of NOTCH1 and that it contributes to SACC proliferation, apoptosis and metastasis. Our findings serve as evidence indicating that HES1 may be useful as a clinical target in the treatment of SACC.

The NOTCH1-HEY1 pathway regulates self-renewal and epithelial-mesenchymal transition of salivary adenoid cystic carcinoma cells.

Our previous study demonstrated a close relationship between the NOTCH signaling pathway and salivary adenoid cystic carcinoma (SACC). Its receptor gene, NOTCH1, and its downstream gene, HES1, contribute to the proliferation, invasion and metastasis of SACC. Accumulating evidence supports HEY1 as another effector of the signaling pathway. The purpose of this study was to explore the effects of the NOTCH1-HEY1 pathway on the proliferation, invasion and metastasis of SACC cells. Our results verified that HEY1 is a specific molecular target of the NOTCH signaling pathway in SACC cells and that its expression in carcinoma is much higher than that in paracarcinoma tissues. The expression of NOTCH1 and HEY1 are positively correlated in the salivary adenoid cystic carcinoma tissues. NOTCH1 is significantly related to the activation of HEY1 in SACC, and that HEY1 reciprocally regulates NOTCH1 expression in SACC. HEY1 promotes cell proliferation and spheroid formation and inhibits cell apoptosis in vitro. In addition, HEY1 enhances the tumorigenicity of SACC in vivo. Furthermore, HEY1 increases cell invasion and metastasis by driving the expression of epithelial-mesenchymal transition (EMT)-related genes and MMPs. The results of this study indicate that the NOTCH1-HEY1 pathway is specifically upregulated in SACC and promotes cell proliferation, self-renewal, invasion, metastasis and the expression of EMT-related genes and MMPs. Our findings suggest that a NOTCH1-HEY1 pathway inhibitor might therefore have potential therapeutic applications in treating SACC patients by inhibiting cancer cell growth and metastasis.

FLI-06 Intercepts Notch Signaling And Suppresses The Proliferation And Self-renewal Of Tongue Cancer Cells.

PURPOSE: The Notch signaling pathway plays an oncogenic role in tongue squamous cell carcinoma. The aim of this study was to inhibit the proliferation and self-renewal of tongue cancer cells by applying Notch signaling pathway inhibitor FLI-06 (Selleck, USA) and to lay a foundation for the clinically targeted treatment of tongue cancer for the future. METHODS: The mRNA expression level of Notch1 and the overall survival rate of patients with tongue cancer were examined by analyzing the TCGA database. Tongue cancer cells were treated with FLI-06. Cell proliferation, apoptosis, and stem cell self-renewal ability were tested in appropriate ways. A xenograft mouse model was established to observe tumor growth. RESULTS: From the TCGA data, we demonstrated that patients with high expression of Notch1 had a poor prognosis. We observed that the Notch signaling pathway inhibitor FLI-06 can restrain the activation of the Notch signaling pathway, decrease cell proliferation and induce cell apoptosis in vitro. The xenograft experiment indicated that intraperitoneal injection of FLI-06 inhibited tumor growth and increased cell apoptosis. FLI-06 suppressed both the mRNA and protein expression of Notch receptor and Notch targeted genes. We also observed that FLI-06 suppressed the proliferation of tongue cancer stem cells. CONCLUSION: FLI-06 can block the proliferation and self-renewal of tongue cancer cells. It is inferred that this compound, which inhibits the Notch signaling pathway, may serve as a potential targeted drug for the treatment of tongue cancer in the clinic.

FZD2 regulates cell proliferation and invasion in tongue squamous cell carcinoma.

Many studies have shown that FZD2 is significantly associated with tumor development and tumor metastasis. The purpose of the present study was to gain insight into the role of FZD2 in the cell proliferation and invasion of tongue squamous cell carcinoma. According to TCGA-HNSC dataset, among the 10 Frizzled receptors, FZD2 exhibited the highest degree of differential expression between cancer tissues and normal tissues, and the overall survival of patients with higher FZD2 levels was shown to be significantly shorter compared with those with lower FZD2 levels. The upregulation of FZD2 in clinical tongue cancer tissues was validated by real-time PCR. Knockdown of FZD2 inhibited the proliferation, migration and invasion of CAL-27 and TCA-8113 cells, whereas overexpression of FZD2 led to the opposite results. Further analysis revealed that FZD2 is positively correlated with WNT3A, WNT5B, WNT7A and WNT2 and is negatively correlated with WNT4. These results indicated that FZD2 may act as an oncogene in tongue squamous cell carcinoma. Therefore, FZD2 may be a target for the diagnosis, prognosis and gene therapy of tongue cancer.

Notch1 regulates tongue cancer cells proliferation, apoptosis and invasion.

OBJECTIVES: Notch1 regulates tumor biology in a complex, context-dependent manner. The roles of Notch1 in tongue cancer are still controversial. The aim of this study is to investigate the roles of Notch1 in tongue cancer. MATERIALS AND METHODS: The expression of Notch1 was tested between tongue cancer and normal samples by using immunohistochemistry. Tongue cancer cells were transfected with siRNA or plasmid, respectively. Cell proliferation, apoptosis, migration and invasion ability were tested in appropriate ways. The subcutaneous tumor model was established to observe the tumor growth. RESULTS: Notch1 was upregulated in tongue carcinoma tissues and the expression of Notch1 was related with tumor stage and differentiation. Overexpression of Notch1 could increase tongue cancer cells proliferation, invasion and migration. But inhibited the expression of Notch1 could decrease cells proliferation, invasion and migration and promote cell apoptosis in vitro and in vivo. CONCLUSION: Our results prove that the oncogenic role of Notch1 in tongue cancer and provide the direction of targeted therapy of tongue cancer.

ID1 contributes to cell growth invasion and migration in salivary adenoid cystic carcinoma.

Previous studies have reported that inhibitor of DNA binding 1 (ID1) exerts an oncogenic role in a number of tumors. In the present study, the role of ID1 in the growth, invasion and migration of salivary adenoid cystic carcinoma (SACC) cells was investigated. ID1 expression in clinical SACC samples was compared with that in normal salivary tissues using immunohistochemical staining, and the correlation between ID1 expression and clinical pathological characteristics was then determined. Subsequently, ID1 was overexpressed or silenced to investigate the effects of ID1 expression on SACC cell proliferation, invasion and migration. In addition, the gene expression levels of known ID1 target genes, including S100A9, CDKN2A and matrix metalloproteinase 1 (MMP1) was measured using reverse transcription­quantitative polymerase chain reaction to elucidate the potential mechanisms of ID1 in SACC. The results of the present study indicated that the protein expression levels of ID1 were significantly increased in the SACC tissues compared with that in the normal salivary tissues (P<0.001), and a positive correlation between ID1 expression and tumor stage (P=0.001), tumor invasion (P=0.002) and metastasis (P=0.019) in SACC was observed. Knockdown of ID1 in SACC cells significantly inhibited cell growth, invasion and migration (all P<0.01), whereas overexpression of ID1 promoted cell proliferation, invasion and migration (all P<0.01). The gene expression level of MMP1 was significantly reduced following ID1 knockdown in SACC­83 cells when compared with negative controls (P<0.05), whereas S100A9 and CDKN2A expression levels were significantly upregulated (both P<0.05). The results suggest that ID1 may regulate the growth, invasion and migration of SACC cells, and that MMP1, S100A9 and CDKN2A may serve as target genes of ID1 and mediate the effects of ID1 in SACC cells. Therefore, ID1 may present a potential target gene for the treatment of patients with SACC to inhibit cancer cell growth and metastasis.

[Analysis of differential expression genes related to different metastasis potential of adenoid cystic carcinoma using restriction fragments differential display PCR].

OBJECTIVE: To construct differential expression profiles of adenoid cystic carcinoma cell lines for screening candidate genes related to metastasis and to verify some candidate genes in adenoid cystic carcinoma. METHODS: Restriction fragments differential display PCR (RFDD-PCR) was used to set up gene expression profiles of adenoid cystic carcinoma cell lines-ACC-M and ACC-2, with high and low metastasis potential respectively. Candidate genes were screened through bioinformatics analysis. Then, a gene family of these candidate genes was checked using semi-quantitative reverse transcription-PCR(RT-PCR). RESULTS: Two gene expression profiles including 5420 gene fragments were constructed, 12 genes of a family called matrix metalloproteinase genes (MMPs) were observed obvious differentially expressed between two cell lines. Results of semi-quantitative RT-PCR also identified this different expression of MMP2,MMP7,MMP9,MMP14,MMP15 and MMP24. CONCLUSION: The construction of gene expression profiles of ACC-M and ACC-2 cell lines makes the foundation for seeking the target genes of adenoid cystic carcinoma. MMP2,MMP7,MMP9 and MMP15 may be relevant with carcinogenesis, development and metastasis of adenoid cystic carcinoma, and different metastasis potential may result from different subtype of MMPs gene family.

FZD2 inhibits the cell growth and migration of salivary adenoid cystic carcinomas.

Several studies have reported that FZD2 regulates tumor biology in a complex manner. The aim of the present study was to identify the role of FZD2 in the cell growth and metastasis of salivary adenoid cystic carcinomas (SACCs). The expression of FZD2 in ACC-83 and ACC-LM cells were measured with real-time PCR. Immunohistochemical staining was used to detect the expression of FZD2 in clinical SACC samples with or without metastasis. Cell proliferation and Transwell assays were performed to explore the effects of FZD2 on cell growth and migration following the silencing of FZD2 with small interference RNAs and the overexpression of FZD2 with plasmid. Our data showed that FZD2 was downregulated in ACC-LM cells, which are an adenoid cystic carcinoma cell line with high metastatic potential, compared to ACC-83 cells, which have low metastatic potential. Additionally, the expression of FZD2 was lower in SACC tissues with metastasis compared to SACC tissues without metastasis (P<0.05). Cell proliferation and migration of ACC-83 cells were increased after the knockdown of FZD2 and decreased following overexpression of FZD2. Knockdown of FZD2 downregulated the expression of PAI-1. Our results suggest that FZD2 may be a tumor suppressor gene in SACCs that inhibits cell growth and migration.

CDH4 suppresses the progression of salivary adenoid cystic carcinoma via E-cadherin co-expression.

The cadherin-4 gene (CDH4) of the cadherin family encodes non-epithelial R-cadherin (R-cad); however, the function of this gene in different types of cancer remains controversial. In this study, we found higher expression of CDH4 mRNA in a salivary adenoid cystic carcinoma (SACC) cell line with low metastatic potential (SACC-83) than in a cell line with high metastatic potential (SACC-LM). By analyzing 67 samples of SACC tissues and 40 samples of paraneoplastic normal tissues, we found R-cad highly expressed in 100% of normal paraneoplastic tissue but only expressed in 64% of SACC tumor tissues (P<0.001). Knockdown of CDH4 expression in vitro promoted the growth, mobility and invasion of SACC cells, and in vivo experiments showed that decreased CDH4 expression enhanced SACC tumorigenicity. Furthermore, CDH4 suppression resulted in down-regulation of E-cadherin (E-cad), which is encoded by CDH1 gene and is a well-known tumor suppressor gene by inhibition of cell proliferation and migration. These results indicate that CDH4 may play a negative role in the growth and metastasis of SACC via co-expression with E-cadherin.

NOTCH1 signaling contributes to cell growth, anti-apoptosis and metastasis in salivary adenoid cystic carcinoma.

BACKGROUND: Numerous studies have reported both the tumor-suppressive and oncogenic roles of the Notch pathway, indicating that Notch activity regulates tumor biology in a complex, context-dependent manner. The aim of the present study was to identify the role of NOTCH1 in the cell growth and metastasis of SACC. METHODS: We analyzed the expression of NOTCH1 in clinical SACC samples using immunohistochemical staining. We silenced the expression of NOTCH1 and overexpressed activated NOTCH1 to elucidate the effects of NOTCH1 on proliferation, migration and invasion. NOTCH1 target genes were validated by real-time PCR. RESULTS: Our results showed that NOTCH1 was upregulated in SACC tissues when compared with normal tissues, and this upregulation was further enhanced in SACC tissues with metastasis and recurrence when compared with SACC tissues without metastasis. Overexpression of NOTCH1 in SACC cells promoted cell growth, migration and invasion, and knockdown of NOTCH1 inhibited cell proliferation in vitro and tumorigenicity in vivo by inducing cell apoptosis. CONCLUSIONS: The results of this study suggest that NOTCH1 plays a key role in the cell growth, anti-apoptosis, and metastasis of SACC. NOTCH1 inhibitors might therefore have potential therapeutic applications in treating SACC patients by inhibiting cancer cell growth and metastasis.

CDH12 promotes the invasion of salivary adenoid cystic carcinoma.

Cadherins are found in almost all living organisms. In addition to their role in the formation and maintenance of normal tissue architecture, cadherins seem to play a crucial role in the cell-cell interactions of cancer cells in tumorigenesis, invasion and metastasis. The aim of the present study was to identify the role of CDH12 in the invasion and metastasis of salivary adenoid cystic carcinoma (SACC). Real-time PCR results showed that CDH12 is abnormally expressed in the highly metastatic SACC cell line ACC-M, compared to ACC-2, a SACC cell line with low metastatic ability. CDH12 expression was significantly higher in clinical samples with metastasis and recurrence than in those without metastasis and recurrence (P<0.05), as demonstrated by immunohistochemical analysis. Overexpression of the CDH12 protein in ACC-M cells infected with an adenovirus vector containing CDH12 enhanced the invasive and migratory ability of ACC-M cells in vitro compared to ACC-M cells infected with empty vector. Likewise, knockdown of CDH12 by small interfering RNA efficiently inhibited the invasion and migration of ACC-M cells in vitro. These results indicate that CDH12 may play an important role in the invasion and metastasis of SACC.

Notch-4 contributes to the metastasis of salivary adenoid cystic carcinoma.

The Notch signaling pathway is important for cell-cell communication; it is involved in gene regulation mechanisms that control multiple cell differentiation processes during embryonic and adult life. Notch is present in all metazoans, and vertebrates possess four different Notch receptors: Notch-1, Notch-2, Notch-3, and Notch-4. The aim of the present study was to identify the role of Notch protein in the metastasis of salivary adenoid cystic carcinoma (SACC). Real-time PCR results showed that Notch-1, Notch-2, and Notch-4 were upregulated in the highly metastatic SACC cell line ACC-M, compared to ACC-2, a SACC cell line with low metastatic ability. Knockdown of Notch-4 by small interfering RNA efficiently inhibited the invasion of ACC-M cells. Notch-4 expression was significantly higher in the clinical samples with metastasis and recurrence compared to that in control (p<0.05), shown by immunohistochemistry analysis. These results indicate that Notch-4 may play an important role in SACC metastasis.

[The expression of matrix metalloproteinases and tissue inhibitor of metalloproteinases in transplanted tumor of salivary adenoid cystic carcinoma cell lines].

PURPOSE: To study the differential expression pattern of MMPs and TIMPs in ACC-M and ACC-2 tumor model. METHODS: High and low metastatic tumor models were set up by transplantion of ACC-M and ACC-2 to nude mouse respectively. Then 3 mice in each group were selected randomly to detect the mRNA level of MMP-2, MMP-7, MMP-9, TIMP-1 and TIMP-2 using semiquantitative RT-PCR,GAPDH was used as internal control. Meanwhile, the expression of MMP-2, MMP-7, MMP-9, TIMP-1 and TIMP-2 in each transplanted tumor were determined by immunohistochemical assay, and IOD value of immunohistochemical reaction was measured. All data were analyzed by SPSS11.5 software package for Student's t test. RESULTS: The results of RT-PCR and immunohistochemistry showed an up-regulation of MMP-2, MMP-7, MMP-9 and TIMP-1 in ACC-M tumor model compared with ACC-2 model (P < 0.05), while the expression of TIMP-2 showed no significant difference between the two models (P > 0.05). CONCLUSION: The differential expression pattern of MMP-2, MMP-7, MMP-9, and TIMP-1 in 2 tumor models may result in different metastasis potential; The 2 tumor models provide good study model for investigation of the metastatic mechanism of salivary adenoid cystic carcinoma.