Glutaredoxin 3 promotes migration and invasion via the Notch signalling pathway in oral squamous cell carcinoma

Substantial evidence indicates that the alteration of the cellular redox status is a critical factor involved in cell growth and death and results in tumourigenesis. Cancer cells have an efficient antioxidant system to counteract the increased generation of ROS. However, whether this ability to survive high levels of ROS has an important role in the growth and metastasis of tumours is not well understood. Glutaredoxin 3 (GLRX3), also known as TXNL2, Grx3 and PICOT, maintains a low level of ROS, thus contributing to the survival and metastasis of several types of cancer. However, little is known about the role of GLRX3 and the underlying mechanisms that suppress oral squamous cell carcinoma (OSCC) progression. Here, by using immunohistochemical staining, we demonstrated that GLRX3 was overexpressed in human OSCC, and enhanced GLRX3 expression correlated with metastasis and with decreased overall patient survival. Knockdown of GLRX3 in human OSCC cell lines reduced Notch activity by reversing the epithelial–mesenchymal transition (EMT), resulting in the inhibition of in vitro migration and invasion. Importantly, knockdown of GLRX3 triggered the generation of ROS. Furthermore, N-acetyl cysteine (NAC), an ROS scavenger, enhanced the effects of GLRX3 knockdown on Notch-dependent EMT. Collectively, these findings suggested the vital roles of GLRX3 in OSCC progression through its relationship with EMT progression, and these data also suggest that a strategy of blocking ROS to enhance the activity of GLRX3 knockdown warrants further attention in the treatment of OSCC.     

黄芩素对人口腔鳞癌细胞增殖和侵袭的作用及其机制

目的：研究黄芩素（BAI）抑制口腔鳞癌细胞（TCA8113）增殖与侵袭及与ERK-FAK的可能关系。方法：本研究分为两次实验,每次实验有4个组：control,20 μmol/L BAI,40 μmol/L BAI,80 μmol/L BAI;control,40 μmol/L BAI,MEK抑制剂（0.33 nmol/L）,MEK抑制剂（0.33 nmol/L）+40 μmol/L BAI。每组3个复孔,各组分别处理24 h和48 h。利用CCK8实验检测黄芩素对口腔鳞癌细胞的增殖抑制作用;半定量PCR及Western blot分析黄芩素对E-cadherin和Vimentin的影响;利用Western blot分析黄芩素对ERK,p-ERK,FAK以及p-FAK的调节作用;采用MEK抑制剂（U0126）,利用Western blot分析其对黄芩素的调控作用。结果：黄芩苷处理组的细胞增殖率明显低于对照组（P<0.01）;黄芩素处理组对E-cadherin的mRNA和蛋白水平的上调作用明显高于对照组,对Vimentin的mRNA和蛋白水平的下调作用也明显低于对照组（P<0.01）;黄芩素处理组的p-ERK和p-FAK的蛋白水平明显低于对照组（P<0.01）,但总的ERK与FAK的蛋白水平与对照组相比没有明显的差别（P<0.05）;MEK抑制剂处理组的E-cadherin的蛋白水平明显高于对照组（P<0.01）,Vimentin,p-ERK和p-FAK的蛋白水平明显低于对照组（P<0.01）,但总的ERK与FAK的蛋白水平与对照组相比没有明显的差别（P<0.05）。结论：黄芩素能够抑制口腔鳞癌细胞的增殖以及侵袭,其机制可能与黄芩素抑制ERK-FAK信号通路有关。     

AKR1C2 acts as a targetable oncogene in esophageal squamous cell carcinoma via activating PI3K/AKT signaling pathway

The aldo‐keto reductases family 1 member C2 (AKR1C2) has critical roles in the tumorigenesis and progression of malignant tumours. However, it was also discovered to have ambiguous functions in multiple cancers and till present, its clinical significance and molecular mechanism in oesophageal squamous cell carcinoma (ESCC) has been unclear. The aim of this study was to explore the role of AKR1C2 in the tumorigenesis of ESCC. Here, we showed that AKR1C2 expression was found to be up‐regulated in ESCC tissues and was significantly associated with pathological stage, lymph node metastasis and worse outcomes. Functional assays demonstrated that an ectopic expression of AKR1C2 in ESCC cells resulted in increased proliferation, migration and cisplatin resistance, while knockdown led to inversing effects. Bioinformation analyses and mechanistic studies demonstrated that AKR1C2 activated the PI3K/AKT signalling pathway, furthermore, the inhibitor of PI3K or the selective inhibitor of AKR1C2 enzyme activity could reverse the aggressiveness and showed synergistic antitumour effect when combined with cisplatin, both in vitro and in vivo. In conclusion, Our findings revealed that AKR1C2 could function as an oncogene by activating the PI3K/AKT pathway, as a novel prognostic biomarker and/or as a potential therapeutic target to ESCC.     

MicroRNA‐29b‐3p suppresses oral squamous cell carcinoma cell migration and invasion via IL32/AKT signalling pathway

Oral squamous cell carcinoma (OSCC) is aggressive accompanied with poor prognosis. We previously isolated the most invasive cells resembling the invasive tumour front by microfluidic technology and explored their differentially expressed microRNAs (miRNAs) in our previous work. Here, we verified the miR‐29b‐3p as a guarder that suppressed migration and invasion of OSCC cells and was down‐regulated in the most invasive cells. Besides that, the invasion suppression role of miR‐29b‐3p was achieved through the IL32/AKT pathway. Thus, miR‐29b‐3p and IL32 might serve as therapeutic targets for blocking the progression and improving the outcome of OSCC.     

siRNA blocking the RAS signalling pathway and inhibits the growth of oesophageal squamous cell carcinoma in nude mice

The aim of this study was to study RAS‐siRNA blocking RAS pathway and suppressing cell growth in human oesophageal squamous cell carcinoma in nude mice. The methods in this study was to construct RAS‐siRNA expression vector, establish 40 oesophageal squamous cell carcinoma xenograft animal models and divided them into five groups: control group, siRNA control group, RAS‐siRNA group, paclitaxel group and RAS‐siRNA and paclitaxel group. We observed tumour growth in nude mice, studied histology by HE staining, tumour growth inhibition by TUNEL assay and detected the RAS, MAPK and cyclin D1 protein expression by immunohistochemistry and western blot. We have obtained the following results: (i) successfully established animal models; (ii) nude mice in each group after treatment inhibited tumour volume was significantly reduced compared with the control group (p < 0.05); (iii) compared with the control group, the number of apoptotic cells were significantly increased in the siRNA control group and the RAS‐siRNA group, and the number of apoptosis cells in the paclitaxel and RAS‐siRNA group is significantly most than the paclitaxel group and RAS‐siRNA group (p < 0.05); and (iv) after treatment, RAS, MAPK and cyclin D1 expression in five groups was decreasing gradually. After adding paclitaxel, the protein expression in the paclitaxel and RAS‐siRNA group was significantly lower than that of paclitaxel group, negative control and paclitaxel group (p < 0.05). We therefore conclude that RAS‐siRNA can block the RAS signal transduction pathway, reduce the activity of tumour cells, arrest tumour cell cycle, promote apoptosis, inhibit cell proliferation and increase tumour cell sensitivity to chemotherapeutic drugs. Copyright © 2014 John Wiley & Sons, Ltd.     

LncRNA TUSC8 inhibits the invasion and migration of cervical cancer cells via miR‐641/PTEN axis

Cervical cancer (CC) is the fourth leading cause of cancer‐related death in women worldwide. There is an urgent need to find novel targets for the treatment of CC. Recently, microRNA have emerged as critical factors in tumorigenesis. In this study, we aimed to investigate the mechanism of miR‐641 on the migration and invasion of CC cells. In silico analysis revealed putative interaction between miR‐641 and phosphatase and tensin homolog (PTEN) RNA/lncRNA tumor suppressor candidate 8 (TUSC8). Hence we evaluated the expression of TUSC8, miR‐641, and PTEN. We found that the expressions of TUSC8 and PTEN were decreased in CC tissues, whereas miR‐641 expression was increased. Inhibition of miR‐641 suppressed the migration and invasion of Hela cells. In addition, TUSC8 and PTEN were upstream and downstream target molecule of miR‐641, respectively. Overexpression of TUSC8 promoted PTEN expression, and suppressed the invasion and migration of Hela cells, whereas miR‐641 mimic treatment changed the effects. These results demonstrated that overexpression of TUSC8 could inhibit the invasion and migration of CC cells by upregulating PTEN via miR‐641.     

TIPE1‐mediated autophagy suppression promotes nasopharyngeal carcinoma cell proliferation via the AMPK/mTOR signalling pathway

Recent studies have shown that tumour necrosis factor‐α–induced protein 8 like‐1(TIPE1) plays distinct roles in different cancers. TIPE1 inhibits tumour proliferation and metastasis in a variety of tumours but acts as an oncogene in cervical cancer. The role of TIPE1 in nasopharyngeal carcinoma (NPC) remains unknown. Interestingly, TIPE1 expression was remarkably increased in NPC tissue samples compared to adjacent normal nasopharyngeal epithelial tissue samples in our study. TIPE1 expression was positively correlated with that of the proliferation marker Ki67 and negatively correlated with patient lifespan. In vitro, TIPE1 inhibited autophagy and induced cell proliferation in TIPE1‐overexpressing CNE‐1 and CNE‐2Z cells. In addition, knocking down TIPE1 expression promoted autophagy and decreased proliferation, whereas overexpressing TIPE1 increased the levels of pmTOR, pS6 and P62 and decreased the level of pAMPK and the LC3B. Furthermore, the decrease in autophagy was remarkably rescued in TIPE1‐overexpressing CNE‐1 and CNE‐2Z cells treated with the AMPK activator AICAR. In addition, TIPE1 promoted tumour growth in BALB/c nude mice. Taken together, results indicate that TIPE1 promotes NPC progression by inhibiting autophagy and inducing cell proliferation via the AMPK/mTOR signalling pathway. Thus, TIPE1 could potentially be used as a valuable diagnostic and prognostic biomarker for NPC.     

Prefoldin 6 promotes glioma progression via the AKT signalling pathway

Gliomas are one of the most aggressive primary tumours, accounting for 81% of malignant brain tumours, and are associated with a significant mortality. Therefore, the elucidation of the molecular mechanism underlying glioma progression and identification of promising treatment targets are necessary. Here, the expression of prefoldin (PFDN) 6 in human glioma tissues and cell lines was evaluated using immunohistochemistry and quantitative polymerase chain reaction. Celigo and CCK-8 assays were performed for assessing cell viability. Flow cytometry was used to analyse apoptosis and cell cycle distribution. Wound-healing and transwell assays were performed to observe cell migration. Lastly, xenograft models were developed for the in vivo validation of the results, and a human phospho-kinase array was used to explore the downstream signalling pathways. PFDN6 was upregulated in gliomas, and PFDN6 overexpression was significantly correlated with a low survival rate, estimated glomerular filtration rate (EGFR) expression, and tumour grade and recurrence. Moreover, PFDN6 knockdown significantly attenuated cell proliferation and migration, induced apoptosis, and blocked cell cycle progression in the G2 phase, which was further confirmed in the in vivo experiments. Mechanistically, the effects of PFDN6 may be mediated via the AKT signalling pathway. In conclusion, we showed that PFDN6 promotes glioma development by activating AKT signalling and emphasised the potential of PFDN6 as a crucial target in glioma therapy.     

CCN5 inhibits proliferation and promotes apoptosis of oral squamous cell carcinoma cells

Oral squamous cell carcinoma (OSCC) is a common cancer with poor prognosis and high mortality. The role of CCN5 has attracted a great focus on the regulation of cancer progression. However, the biological function and mechanism of CCN5 in OSCC are still not well elucidated. The current study was designed to determine the effects of CCN5 on OSCC cell proliferation and apoptosis using two OSCC cell lines. Further, LY294002, a PI3K/AKT antagonist, was employed to explore the mechanism underlying the effects of CCN5 in the regulation of OSCC. The results showed that overexpression of CCN5 in TSCCa cells significantly reduced viable cell number, arrested cell cycle, and suppressed cell‐cycle regulators (cyclin D1, cyclin E, and CDK2). CCN5 overexpression increased the apoptotic ratio and Hoechst‐positive cell number, and altered the apoptotic‐related proteins (caspase‐3/9, Bax, and Bcl‐2). However, CCN5 silencing induced opposite effects on cell proliferation and apoptosis in Tca‐8113 cells. In addition, we observed that CCN5 knockdown increased the expression levels of PI3K (p85α and p110α) and phosphorylated AKT at serine 473 (p‐AKT Ser473) in Tca‐8113 cells. Inhibiting PI3K/AKT signaling with LY294002 rescued the apoptotic process in CCN5‐silenced OSCC cells. Finally, xenograft analysis showed that CCN5 represses tumorigenesis of OSCC cells. These findings together suggest that CCN5 functions as a tumor suppressor for OSCC cell development through inactivation of PI3K/AKT signaling pathway, providing a potential candidate for OSCC therapy.     

Long noncoding RNA HAND2-AS1 inhibits cancer cell proliferation,migration, and invasion in esophagus squamous cell carcinoma by regulating microRNA-21

Long noncoding RNA (lncRNA) HAND2-AS1 is a well-characterized tumor suppressor in several types of malignancies, while its role in esophagus squamous cell carcinoma (ESCC) is unknown. In this study, we found that lncRNA HAND2-AS1 was downregulated, while microRNA-21 ( miRNA-21) was upregulated in tumor tissues than in adjacent healthy tissues of ESCC patients. Expression levels of lncRNA HAND2-AS1 and miRNA-21 were significantly and inversely correlated in tumor tissues but not in healthy tissues. Plasma levels of lncRNA HAND2-AS1 were lower in ESCC patients than in healthy controls, and downregulation of plasma lncRNA HAND2-AS1 distinguished early stage ESCC patients from healthy controls. lncRNA HAND2-AS1 overexpression resulted in downregulation of miRNA-21 in cells of ESCC cell lines and inhibited cell proliferation, migration, and invasion. miRNA-21 overexpression failed to affect lncRNA HAND2-AS1 expression but significantly attenuated the inhibitory effect of lncRNA HAND2-AS1 overexpression on cancer cell proliferation, migration, and invasion. Therefore, lncRNA HAND2-AS1 may inhibit cancer cell proliferation, migration, and invasion in ESCC by regulating miRNA-21.     

TMEM184B promotes proliferation,migration and invasion,and inhibits apoptosis in hypopharyngeal squamous cell carcinoma

Several members of the transmembrane protein family are associated with the biological processes of human malignancies; however, the expression pattern and biological function of one family member, TMEM184B, in hypopharyngeal squamous cell carcinoma (HPSCC) are not fully understood. The expression between HPSCC tumours and adjacent normal tissues was determined by the Immunohistochemistry (IHC). A bioinformatics analysis was performed to verify the expression pattern of TMEM184B in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Furthermore, in vitro assays on cell proliferation, invasion, migration and in vivo experiments on tumour growth and apoptosis of TMEM184B in HPSCC were performed. We found that the HPSCC tissues had a significantly higher expression of TMEM184B than the adjacent normal tissues. Bioinformatics analysis confirmed the different expression of TMEM184B expression in HPSCC. Furthermore, in vitro and in vivo experiments demonstrated that TMEM184B promotes HPSCC cell growth, cell invasion and migration in FaDu cells, whereas flow cytometry assay showed that TMEM184B inhibited cell apoptosis. Our study revealed for the first time that TMEM184B might serve an oncogenic function in HPSCC and could be a potential diagnostic biomarker and therapeutic target for HPSCC.     

RBM10 inhibits cell proliferation of lung adenocarcinoma via RAP1/AKT/CREB signalling pathway

Initial functional studies have demonstrated that RNA‐binding motif protein 10 (RBM10) can promote apoptosis and suppress cell proliferation; however, the results of several studies suggest a tumour‐promoting role for RBM10. Herein, we assessed the involvement of RBM10 in lung adenocarcinoma cell proliferation and explored the potential molecular mechanism. We found that, both in vitro and in vivo, RBM10 overexpression suppresses lung adenocarcinoma cell proliferation, while its knockdown enhances cell proliferation. Using complementary DNA microarray analysis, we previously found that RBM10 overexpression induces significant down‐regulation of RAP1A expression. In this study, we have confirmed that RBM10 decreases the activation of RAP1 and found that EPAC stimulation and inhibition can abolish the effects of RBM10 knockdown and overexpression, respectively, and regulate cell growth. This effect of RBM10 on proliferation was independent of the MAPK/ERK and P38/MAPK signalling pathways. We found that RBM10 reduces the phosphorylation of CREB via the AKT signalling pathway, suggesting that RBM10 exhibits its effect on lung adenocarcinoma cell proliferation via the RAP1/AKT/CREB signalling pathway.     

MiR-143-3p suppresses cell proliferation,migration, and invasion by targeting Melanoma-Associated Antigen A9 in laryngeal squamous cell carcinoma

Previously we found that melanoma-associated antigen-A9 (MAGE-A9) was a significantly upregulated biomarker in laryngeal squamous cell carcinoma (LSCC). A high expression of MAGE-A9 indicates an unfavorable survival outcome, and the MAGE-A9 expression level is an independent prognostic factor of LSCC. To explore the mechanism of MAGE-A9 upregulation, several predicted regulatory microRNAs were screened and validated in LSCC cells. In the current study, we found that miR-143-3p (MAGE-A9 related miRNAs) expression levels correlated negatively with the MAGE-A9 protein expression in LSCC tissues. Dual-luciferase reporter assays and Western blot analysis revealed MAGE-A9 to be a direct target of miR-143-3p. Furthermore, a series of in vitro gain- and loss-of-function assays revealed that miR-143-3p inhibited LSCC cell proliferation, migration, and invasion. Also, miR-143-3p suppressed LSCC tumorigenesis in vivo. These effects were clinically relevant, as a lower expression of miR-143-3p occurred in severer clinical stages and represented poor overall survival in patients with LSCC. Taken together, these results suggest that downregulation of miR-143-3p contributes to tumor progression through upregulation of MAGE-A9. The expression level of these two key molecules maintained LSCC progression, thus, highlighting the potential of miR-143-3p as a therapeutic target for human LSCC.     

GHR is involved in gastric cell growth and apoptosis via PI3K/AKT signalling

Growth hormone receptor (GHR), the cognate receptor of growth hormone (GH), is a membrane bound receptor that belongs to the class I cytokine receptor superfamily. GH binding GHR induces cell differentiation and maturation, initiates the anabolism inside the cells and promotes cell proliferation. Recently, GHR has been reported to be associated with various types of cancer. However, the underlying mechanism of GHR in gastric cancer has not been defined. Our results showed that silence of GHR inhibited the growth of SGC-7901 and MGC-803 cells, and tumour development in mouse xenograft model. Flow cytometry showed that GHR knockout significantly stimulated gastric cancer cell apoptosis and caused G1 cell cycle arrest, which was also verified by Western blot that GHR deficiency induced the protein level of cleaved-PARP, a valuable marker of apoptosis. In addition, GHR deficiency inhibited the activation of PI3K/AKT signalling pathway. On the basis of the results, that GHR regulates gastric cancer cell growth and apoptosis through controlling G1 cell cycle progression via mediating PI3K/AKT signalling pathway. These findings provide a novel understanding for the role of GHR in gastric cancer.