Ubiquitin-specific protease 7 is a drug-able target that promotes hepatocellular carcinoma and chemoresistance.

BACKGROUND: Ubiquitin-specific protease 7 (USP7) is a de-ubiquitin enzyme that plays an essential role in multiple cancers and becomes a target for treatment. However, the role of USP7 and its therapeutic value for HCC remains unclear. METHODS: USP7 expression was examined in HCC tissues by western blot and immunohistochemistry. The correlation of USP7 and HCC prognosis was analyzed by Kaplan-Meier survival method. Mass spectrometry was determined and cell proliferation and tumorigenicity assays were conducted in vitro and in vivo treated by P22077 and sgRNA-USP7. RESULTS: USP7 expression was significantly increased in HCC and associated with its progression. Interestingly, many HCC cells are sensitive to USP7 inhibition by using P22077. P22077 treatment not only induced cell death but also inhibited cell proliferation and migration in Huh7 and SK-Hep1 cells. In a xenograft model, P22077 efficiently inhibited tumor growth. In chemo-resistant HCC cells, P22077 decreased cell sensitivity to chemotherapy. In addition, mass spectrometry reveals 224 of significantly changed proteins upon P22077 treatment. CONCLUSIONS: We demonstrate a critical role of USP7 in HCC devolvement and chemoresistance. Disruption of USP7 function results in dis-regulated several key biological processes and subsequently activates BAX. USP7 might be a novel and drug-able target in HCC.

Nucleolar spindle-associated protein 1 promotes tumorigenesis and predicts poor prognosis in human esophageal squamous cell carcinoma.

The microtubule binding protein, nucleolar spindle-associated protein 1 (NUSAP1), has a crucial function in mitosis and its expression is closely associated with carcinogenesis. Herein, we aimed to determine the function of NUSAP1 in the development of human esophageal squamous cell carcinoma (ESCC), and the association of NUSAP1 expression with ESCC. Immunohistochemical staining of ESCC tissue sections indicated that NUSAP1 was expressed to a higher degree in tumor tissues than in adjacent nontumor tissues. NUSAP1 levels were relevant closely to histological differentiation (P = 0.049). Overall survival was longer in patients with lower NUSAP1 levels ( P < 0.001). NUSAP1 expression ( P = 0.002), histological differentiation ( P < 0.001), tumor depth ( P = 0.045), lymph node metastases ( P < 0.001), and tumor-node-metastasis staging ( P = 0.008) were greatly associated with overall survival using univariate analysis. Multivariate analysis suggested that histological differentiation ( P = 0.014) and NUSAP1 expression ( P = 0.026) could be independent prognostic markers for ESCC. Additionally, the biological behavior of ESCC cells was investigated in vitro and in vivo. Suppression of NUSAP1 inhibited cellular proliferation and invasion, and induced cell cycle arrest and apoptosis in vitro. More importantly, knockdown of NUSAP1 led to inhibition of tumor formation in nude mice. These findings indicated that NUSAP1 is a potential prognostic biomarker in ESCC, and is an ESCC oncogene. Thus, NUSAP1 could represent a therapeutic target for ESCC.

Coupling function of cyclin-dependent kinase 2 and Septin2 in the promotion of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common and aggressive malignant tumor with a poorly defined molecular mechanism. Cyclin-dependent kinase 2 (CDK2) and Septin2 (SEPT2) are 2 known oncogenic molecules but the mechanism of functional interactions remains unclear. Here, we interestingly found that CDK2 and SEPT2 show very similar dynamic expression during the cell cycle. Both CDK2 and SEPT2 show the highest protein levels in the G2/M phase, resulting in CDK2 interacting with SEPT2 and stabilizing SEPT2 in HCC. In a panel of 8 pairs of fresh HCC tissues and corresponding adjacent tissues, both western blot and immunohistochemistry (IHC) assays demonstrate that CDK2 expression is highly correlated with SEPT2. HCC with high expression of both CDK2 and SEPT2 are more likely to relapse. This observation is further demonstrated by a large panel of 100 HCC patients. In this large panel, high expression of both CDK2 and SEPT2 significantly correlates with tumor differentiation and microvascular invasion, which is an independent prognostic factor in HCC patients. In summary, our results reveal a cooperative function between CDK2 and SEPT2. HCC with high expression of CDK2 and SEPT2 might be more aggressive and respond poorly to current therapy.

MKP-4 suppresses hepatocarcinogenesis by targeting ERK1/2 pathway.

BACKGROUND: Mitogen-activated protein kinase phosphatases-4 (MKP-4) is reported to exert a prognostic merit in hepatocarcinogenesis. However, the underlying molecular mechanisms have not been clearly defined. METHODS: Immunoprecipitation-mass spectrometry (IP-MS) approach was used to identify interactive proteins with MKP-4. Western blot and immunohistochemistry were employed to detect proteins in HCC tissues. Cell counting kit-8, colony formation, Edu incorporation and sphere formation assays were performed to investigate functions of MKP-4/ERK1/2 interaction. Tumor xenografts in nude mice were used to determine effects in vivo. RESULTS: Extracellular signal-regulated kinase 1 and 2 (ERK1/2) were identified as binding partners of MKP-4. Knockdown of MKP-4 increased cell proliferation and cancer stem cell (CSC) traits while upregulation of MKP-4 or pre-incubation with ERK1/2 inhibition reversed these effects. Mechanistically MKP-4 negatively regulated phosphorylation of ERK1/2 and reduced expressions of CyclinD1 and c-Myc. Both xenograft tumor models and clinical analysis of HCC patients indicated that lower expression of MKP-4 and higher expressions of ERK1/2 were associated with worse prognosis. CONCLUSIONS: MKP-4-mediated dephosphorylation of ERK1/2 might serve as a novel tumor-suppressive mechanism and provide a potential therapy for HCC.

Progress in the application of exosomes as therapeutic vectors in tumor-targeted therapy.

Cancer is the second leading cause of death in the world with a high annual incidence level. Researchers have been working on developing treatments for cancer. Targeted therapy is an emerging treatment modality that is more novel than surgery, radiotherapy and chemotherapy. In targeted therapy, exogenous nanoscale microparticles are applied as carriers for drugs or genes. However, conventional particles have certain limitations attributed to non-specific cytotoxicity, biocompatibility and low delivery efficacy in individual therapeutic vector systems. Exosomes are small vesicles secreted by various cells that consist of lipid bilayer membranes without organelles. Due to their excellent biocompatibility, exosomes have received increased attention in recent years for targeted therapy applications. This review briefly introduces the current status of targeted therapy, and exosomes are introduced by their structural characteristics, physiological effects and separation methods. This review also discusses the applications of engineered exosomes derived from different cells in the field of targeted therapies and compares the two-way regulation of mesenchymal stromal cell-derived exosomes in tumor therapy.

Correlation between S100A11 and the TGF-ß1/SMAD4 pathway and its effects on the proliferation and apoptosis of pancreatic cancer cell line PANC-1.

S100A11 as a S100 protein family member has been documented to play dual-direction regulation over cancer cell proliferation. We explored the role of S100A11 in the proliferation and apoptosis of pancreatic cancer cell line PANC-1 and the potential mechanisms involving the TGF-ß1/SMAD4/p21 pathway. S100A11 and TGF-ß1 protein expressions in 30 paraffin-embedded specimens were evaluated by immunohistochemistry. S100A11 and TGF-ß1 expression in PANC-1 cell line was suppressed using small interfering RNA (siRNA), respectively. Subsequently, pancreatic cancer cell apoptosis was measured by Cell Counting Kit-8 and flow cytometry, and S100A11 and TGF-ß1/SMAD4/p21 pathway proteins and genes were detected with Western blotting and quantitative polymerase chain reaction (qPCR). S100A11 cytoplasmic/nuclear protein translocation was examined using NE-PER® cytoplasm/nuclear protein extraction in cells interfered with TGF-ß1 siRNA. Our results showed that S100A11 expression was positively correlated with TGF-ß1 expression in pancreatic cancerous tissue. Silencing TGF-ß1 down-regulated intracellular P21WAF1 expression by 90%, blocked S100A11 from cytoplasm entering nucleus, and enhanced cell proliferation. Silencing S100A11 down-regulated intracellular P21 expression and promoted cell apoptosis without significantly changing TGF-ß1 and SMAD4 expression. Our findings revealed that S100A11 and TGF-ß1/SMAD4 signaling pathway were related but mutually independent in regulating PANC-1 cells proliferation and apoptosis. Other independent mechanisms might be involved in S100A11's regulation of pancreatic cell growth. S100A11 could be a potential gene therapy target for pancreatic cancer.

Effects of TACE and preventive antiviral therapy on HBV reactivation and subsequent hepatitis in hepatocellular carcinoma: a meta-analysis.

BACKGROUND AND AIM: The impact of transarterial chemoembolization (TACE) and preventive antiviral therapy on the occurrence of hepatitis B virus (HBV) reactivation and subsequent hepatitis remains controversial. This meta-analysis aimed to evaluate the effect of TACE and preventive antiviral therapy on the risk of HBV reactivation and subsequent hepatitis. Meanwhile, we explored the role of HBeAg status in HBV reactivation after TACE. METHODS: We performed this meta-analysis with 11 included studies to assess the effect of TACE and preventive antiviral therapy on predicting clinical outcomes in HBV-related hepatocellular carcinoma (HCC). The pooled odds ratios (OR) were calculated using a random or fixed effects model. PUBMED, MEDLINE, EMBASE and the Cochrane Central Register of Controlled were searched for the included articles (from 2000 to December 2017). RESULTS: Our results showed that TACE significantly increased the risk of HBV reactivation (OR: 3.70; 95% CI 1.45-9.42; P < 0.01) and subsequent hepatitis (OR: 4.30; 95% CI 2.28-8.13; P < 0.01) in HCC patients. There was no significant difference in HBV reactivation after TACE between HBeAg positive and negative patients (OR: 1.28; 95% CI 0.31-5.34; P = 0.73). Preventive antiviral therapy could statistically reduce the rate of HBV reactivation (OR: 0.08; 95% CI 0.02-0.32; P < 0.01) and hepatitis (OR: 0.22; 95% CI 0.06-0.80; P = 0.02) in those with TACE treatment. CONCLUSIONS: The present study suggested that TACE was associated with a higher possibility of HBV reactivation and subsequent hepatitis. Preventive antiviral therapy is significantly in favor of a protective effect.

ß2-AR regulates the expression of AKR1B1 in human pancreatic cancer cells and promotes their proliferation via the ERK1/2 pathway.

Psychological stress has been recognized as a well-documented risk factor associated with ß2-adrenergic receptor (ß2-AR) in the development of pancreatic cancer. Aldo-keto reductase 1 member B1 (AKR1B1) is a potential interacting partner of ß2-AR, but the effect of their interaction on pancreatic cancer cells is not known at present. We found a positive correlation between AKR1B1 and ß2-AR expression in pancreatic cancer tissue samples, and co-localization of these proteins in the human pancreatic cancer BXPC-3 cell line. Compared to the controls, the CFPAC-1 and PANC-1 pancreatic cancer cells overexpressing ß2-AR and AKR1B1 respectively showed significantly higher proliferation rates, which is attributed to higher proportion of cells in the S phase and decreased percentage of early apoptotic cells. Furthermore, overexpression of ß2-AR led to a significant increase in the expression of AKR1B1 and phosphorylated extracellular signal-regulated kinase (p-ERK1/2). Overexpression of AKR1B1 significantly decreased ß2-AR levels and increased that of p-ERK1/2. Taken together, ß2-AR directly interacted with and up-regulated AKR1B1 in pancreatic cancer cells, and promoted their proliferation and inhibited apoptosis via the ERK1/2 pathway. Our findings also highlight the ß2-AR-AKR1B1 axis as a potential therapeutic target for pancreatic cancer.

Modification of p27 with O-linked N-acetylglucosamine regulates cell proliferation in hepatocellular carcinoma.

The tumor suppressor p27, which is a member of the Cip/Kip family of Cyclin-dependent kinase inhibitory proteins (CKIs), controls anti-proliferative events. The post-translational addition of O-GlcNAc to p27 occurs in HEK293T and HCC (hepatocellular carcinoma) cell lines, and we identified Ser2, Ser106, Ser110, Thr157, and Thr198 as the glycosylation sites of p27 based on the Q-TOF spectrum. Here, immunoprecipitation analysis showed that Ser2 was O-GlcNAcylated and that this modification was associated with the increased phosphorylation of p27 at Ser10, ultimately resulting in p27 accumulation in the cytoplasm and increased p27 ubiquitination. In addition, O-GlcNAcylation at Ser2 suppressed Cyclin/CDK complex-p27 interactions by promoting the nuclear export of p27, thus facilitating cell cycle progression. Cell proliferation was negatively regulated when Ser2 of p27 was replaced with Ala. Furthermore, western blot and immunohistochemical analyses of HCC tissues and their corresponding nontumorous tissues were performed, and we found that O-GlcNAcylated p27 correlated with cell proliferation in HCC. Together, our results indicate that the dynamic interplay between O-GlcNAcylation and p27 phosphorylation coordinates and regulates cell proliferation in hepatocellular carcinoma. © 2016 Wiley Periodicals, Inc.

Hyper-O-GlcNAcylation of YB-1 affects Ser102 phosphorylation and promotes cell proliferation in hepatocellular carcinoma.

As an essential post-translational modification, O-GlcNAcylation has been thought to be able to modulate various nuclear and cytoplasmic proteins and is emerging as a key regulator of multiple biological processes, such as transcription, cell growth, signal transduction, and cell motility. Recently, authoritative glycomics analyses have reported extensive crosstalk between O-GlcNAcylation and phosphorylation, which always dynamically interplay with each other and regulate signaling, transcription, and other cellular processes. Also, plentiful studies have shown close correlation between YB-1 phosphorylation and tumorigenesis. Therefore, our study aimed to determine whether YB-1 was O-GlcNAc modified and whether such modification could interact with its phosphorylation during the process of HCC development. Western blot and immunohistochemistry were firstly conducted to reveal obvious up-regulation of YB-1, OGT and O-GlcNAc modification in HCC tissues. What is more, not only YB-1 was identified to be O-GlcNAcylated but hyper-O-GlcNAcylation was demonstrated to facilitate HCC cell proliferation in a YB-1 dependent manner. Moreover, we detected four specific O-GlcNAc sites and confirmed T126A to be the most effective mutant in HCC cell proliferation via close O-GlcNAcylation-phosphorylation interaction. Even more interestingly, we discovered that T126A-induced HCC cell retardation and subdued transcriptional activity of YB-1 could be partially reversed by T126A/S102E mutant. From all above, it is not difficult to find that glycosylated-YB-1 mainly enhanced cell proliferation through congenerous actions with YB-1 phosphorylation and thus played indispensable roles in fine-tuning cell proliferation and procession of HCC.

High Expression of BCCIP ß Can Promote Proliferation of Esophageal Squamous Cell Carcinoma.

BACKGROUND: BCCIP was originally identified as a BRCA2 interacting protein in humans and Ustilago maydis. It had low expression in some human cancer tissues. However, recent research indicated that many caretaker genes are also necessary for cell viability and their expression could contribute to tumor progression. AIM: To characterize whether BCCIP is a caretaker gene in esophageal squamous cell carcinoma (ESCC). METHODS: Western blotting and immunohistochemistry were used to measure the expression of BCCIP ß. In vitro studies were used to verify the effects of BCCIP ß in Eca109 cells. RESULTS: Expression of BCCIP ß was notably higher in tumor tissues of ESCC and Eca 109 cells. Meanwhile, the immunohistochemistry stain revealed that BCCIP ß was positively correlated with clinical pathologic variables such as tumor size and tumor grade, as well as Ki-67, and prompted poor prognosis. In vitro studies such as starvation and refeeding assay along with BCCIP ß-shRNA transfection assay demonstrated that BCCIP ß expression promoted proliferation of ESCC cells. In addition, BCCIP ß downregulation by silencing RNA significantly decreased the rate of colony formation, alleviated cellular apoptosis and increased the chemosensitivity of cisplatin. CONCLUSIONS: This research first put forward that BCCIP ß is an oncogene in human ESCC and contributes to the poor outcome of the deadly disease.

GAB2 promotes cell proliferation by activating the ERK signaling pathway in hepatocellular carcinoma.

Grb2-associated binding protein 2 (GAB2), a key member of the family of Gab scaffolding adaptors, is important in the phospoinositide3-kinase (PI3K) and extracellular signal-regulated kinase (ERK) signaling pathways, and is closely associated with cell proliferation, cell transformation, and tumor progression. But its role in hepatocellular carcinoma (HCC) is still unknown. In this study, we investigated the expression of GAB2 and its potential clinical and biological significances in HCC. Western bolt and immunohistochemistrical analyses revealed that GAB2 was obviously upregulated in HCC tissues. Meanwhile, GAB2 was significantly associated with histological grade, tumor size, and the proliferation marker Ki-67 through our further analysis. The Kaplan-Meier survival curves also showed that increased GAB2 expression was directly correlated with poor prognosis in HCC patients and served as an independent prognostic marker of overall survival. Moreover, serum starvation-refeeding, RNA interference, CCK-8, EDU, colony formation, and flow-cytometry analyses were all performed with the purpose of investigating GAB2's regulation of HCC cell proliferation. Our results indicated that GAB2 progressively accumulated when cells entered into S phase. Consistently, cell proliferation was distinctly hindered by small interfering RNA. More interestingly, we discovered that GAB2 promoted cell proliferation by enhancing ERK signaling and GAB2-induced cell proliferation was inhibited by the inhibition of ERK activation. Finally, GAB2 was verified to be able to confer doxorubicin resistance in HCC cells. In summary, these data demonstrated that GAB2 might promote HCC cell proliferation by enhancing ERK signaling, and all above findings provided a potential therapeutic strategy for the treatment of HCC.

Low expression of PIDD is associated with cell proliferation and apoptosis in hepatocellular carcinoma.

p53-induced death domain protein (PIDD) facilitates p53-dependent apoptosis through the interaction with components of the death receptor signaling pathways. However, the role of PIDD in hepatocellular carcinoma (HCC) development remains unknown. In this study, we investigated the expression pattern of PIDD in clinical HCC samples and adjacent non-cancerous tissues using immunohistochemistrical and Western blot analyses. The results showed that PIDD was lowly expressed in HCC tissues and HCC cell lines, compared with the adjacent non-tumorous tissues and LO2 normal hepatocytes. In addition, clinicopathological analysis showed that the expression of PIDD was closely related with multiple clinicopathological variables, such as American Joint Committee on Cancer (AJCC) stage, AFP, and poor prognosis of HCC. Univariate and multivariate survival analyses demonstrated that PIDD could serve as an independent prognostic factor to predict the survival of HCC patients. We used serum starvation-refeeding experiment to explore the involvement of PIDD in HCC cell cycle regulation. We found that PIDD was accumulated in growth-arrested HCC cells and was progressively decreased when cells entered into S phase. Moreover, flow cytometry and cell counting kit-8 (CCK-8) assays indicated that depleting the expression of PIDD could facilitate cell cycle progression and accelerate cell proliferation in HepG2 cells, while overexpression of PIDD could result in cell cycle arrest at G1 phase and hinder the cell proliferation in Hep3B cells. Finally, flow cytometry revealed that overexpression of PIDD slightly increased the apoptosis of HCC cells. Taken together, we concluded that PIDD may be a valuable prognostic marker and promising therapeutic target of HCC.

PKC iota promotes cellular proliferation by accelerated G1/S transition via interaction with CDK7 in esophageal squamous cell carcinoma.

Protein kinase C iota (PKCι) has been shown to play an important role in tumorigenesis of many cancers. It was reported that frequent amplification and overexpression of PKCi were correlated with resistance to anoikis in primary esophageal squamous cell carcinomas (ESCC). In this study, we clarified a novel role of PKCι on the cell cycle progression and proliferation in ESCC. Western blot and immunohistochemistry (IHC) analysis showed that the expression of PKCι was higher in ESCC tumor tissues and cell lines. Meanwhile, IHC stain revealed that PKCι was positively correlated with clinical pathologic variables such as tumor size, tumor grade, and tumor invasion, as well as ki67. Immunoprecipitation and immunofluorescence assay revealed that PKCι/CDK7 has the physical interaction and were co-located in the cell nucleus. And this direct interaction could increase the phosphorylation level of CDK7. In vitro studies such as starvation and refeeding assay along with PKCι-shRNA transfection assay demonstrated that PKCι expression promoted proliferation of ESCC cells. And knocking PKCi down by silencing RNA (siRNA) significantly caused cell cycle arrest at G0/G1 phase, decreased rate of colony formation, and alleviated cellular apoptosis. This research provide new insights into PKCi signaling to more deeply understand its cancer-promoting function in ESCC.

Expression pattern of BCCIP in hepatocellular carcinoma is correlated with poor prognosis and enhanced cell proliferation.

BCCIP was originally identified as a BRCA2- and CDKN1A- (Cip1/waf1/p21) interacting protein, also known as BCCIP. It has been reported to express in various types of cancers, including colorectal cancer (CRC), astrocytic brain tumors, and glioblastomas. However, the relationship between BCCIP expression and clinicopathological features of hepatocellular carcinoma (HCC) remains to be determined. Herein, we demonstrated that BCCIP was downregulated in clinical HCC tissues; its level was inversely correlated with multiple clinicopathological factors, such as tumor grade, tumor size, and Ki67 expression. Cox regression analysis of tumor samples revealed that BCCIP expression status was an independent prognostic factor for HCC patients' poor survival. Our study also indicated that BCCIP shutdown reduces p21 expression and accelerates G1 to S progression of LO2 hepatocytes significantly. Moreover, there is an interaction between BCCIP and p53 in hepatic L02 cells, and the downregulation of p21 expression by BCCIP is in a p53-dependent way. These findings revealed that BCCIP may play a significant role for the determination of HCC progression through its role in regulating cell growth. Thus, our results suggest that BCCIP is of potential interest for prognostic marker and therapeutic target of HCC.

Far upstream element-binding protein 1 (FUBP1) is a potential c-Myc regulator in esophageal squamous cell carcinoma (ESCC) and its expression promotes ESCC progression.

The human far upstream element (FUSE) binding protein 1 (FUBP1) belongs to an ancient family which is required for proper regulation of the c-Myc proto-oncogene. Although c-Myc plays an important role in development of various carcinomas, the relevance of FUBP1 and their contribution to esophageal squamous cell carcinoma (ESCC) development remain unclear. In this study, we aimed to investigate the relationship between FUBP1 and c-Myc as well as their contribution to ESCC development. Western blot and immunohistochemical analyses were performed to evaluate FUBP1 expression. Coimmunoprecipitation analysis was performed to explore the correlation between FUBP1 and c-Myc in ESCC. In addition, the role of FUBP1 in ESCC proliferation was studied in ESCC cells through knocking FUBP1 down. The regulation of FUBP1 on proliferation was confirmed by Cell Counting Kit-8 (CCK-8) assay, flow cytometric assays, and clone formation assays. The expressions of FUBP1 and c-Myc were both upregulated in ESCC tissues. In addition to correlation between expression of FUBP1 and tumor grade, we also confirmed the correlation of FUBP1, c-Myc, and Ki-67 expression by twos. Moreover, upregulation of FUBP1 and c-Myc in ESCC was associated with poor survival. FUBP1 was confirmed to activate c-Myc in ESCC tissues and cells. FUBP1 was demonstrated to promote proliferation of ESCC cells. Moreover, downregulation of both FUBP1 and c-Myc was confirmed to inhibit proliferation of ESCC cells. Our results indicated that FUBP1 may potentially stimulate c-Myc expression in ESCC and its expression may promote ESCC progression.

Upregulated TRIM32 correlates with enhanced cell proliferation and poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and the sixth most prevalent human malignancies worldwide. However, the molecular mechanisms underlying hepatocarcinogenesis remain unclear. For HCC patients, there is not only a lack of effective therapeutic targets but also a lack of predictive or prognostic biomarkers. In this article, we reported that TRIM32 was obviously upregulated in HCC tumor tissues and HCC cell lines. Its expression patterns were positively correlated with histological grade, tumor sizes, and HBsAg of HCC patients. TRIM32 expression was a significant predictor for the overall survival time of HCC patients. Moreover, the overexpression of TRIM32 in cells accelerated the G1-S phase transition, promoted cell proliferation rates, and induced the resistance of HCC patients to oxaliplatin. All these findings suggest that TRIM32 might play important roles in the hepatocarcinogenesis. TRIM32 could be a novel direction to explore the mechanism underlying HCC pathogenesis.

Overexpression of DLX2 is associated with poor prognosis and sorafenib resistance in hepatocellular carcinoma.

The mechanism underlying poor prognosis and sorafenib resistance in patients with hepatocellular carcinoma (HCC) is unknown and, to date, no useful predictive biomarkers of sorafenib resistance have been identified. Distal-less homeobox 2 (DLX2) is a transcription factor involved in cell cycle regulation that is closely correlated with cancer prognosis. In this study, we showed that DLX2 is overexpressed in HCC tissues and cell lines and that the level of DLX2 overexpression is positively correlated with histological grade, metastasis and Ki67 expression, which are indicators of poor prognosis. We also found that DLX2 accumulates in proliferating HCC cells, where it is associated with the expression of proliferating cell nuclear antigen (PCNA), Cyclin D1 and Cyclin A. Flow cytometry and cell counting kit-8 (CCK-8) assays indicated that DLX2 depletion causes cell cycle arrest at the G1 phase and hinders cell proliferation. Moreover, the sensitivity of HCC cells to sorafenib is restored when the DLX2 gene is knocked down using a short interfering RNA. We demonstrated that DLX2 facilitates sorafenib resistance by promoting the expression of markers of epithelial-mesenchymal transition and by activating the extracellular signal-regulated protein kinase pathway. Our findings reveal that DLX2 plays a regulatory role in HCC cell proliferation and suggests that targeting DLX2 represents a novel strategy to increase sorafenib efficacy in the management of HCC. In conclusion, DLX2 is a novel marker of poor prognosis and sorafenib resistance in patients with HCC.

The suppressor of cytokine signaling SOCS1 promotes apoptosis of intestinal epithelial cells via p53 signaling in Crohn's disease.

The suppressor of cytokine signaling SOCS1 is a member of the cytokine signaling pathway inhibitor family, which is induced by the IFN-γ induced JAK signaling pathway. The expression of SOCS1 has been found to increase in Crohn's disease (CD) patients, but the role of SOCS1 in intestinal epithelium is unclear. This study was designed to investigate whether SOCS1 has a role in the death of intestinal epithelial cells and intestinal injury. The results showed that the expression of SOCS1 increased in CD patients, and the expression of SOCS1, p-p53 and PUMA increased in the mouse TNBS induced colitis model. Using IFN-γ treated HT-29 cells as an apoptotic model of intestinal epithelial cells in vitro, we confirmed that SOCS1 promoted apoptosis of intestinal epithelial cells by activating p53. In HT-29 cells which were treated with IFN-γ, the interaction between p53 and SOCS1 and phosphorylation of p53 were significantly higher than untreated cells. When knocking SOCS1 down by using SOCS1 siRNA, phosphorylation of p53 and apoptosis of intestinal epithelial cells which was induced by IFN-γ were significantly inhibited. In summary, our findings suggest that SOCS1 may promote apoptosis of intestinal epithelial cells at least partly through mediating p53 signaling.

Expression and Clinical Role of Cdc5L as a Novel Cell Cycle Protein in Hepatocellular Carcinoma.

BACKGROUND: Cell division cycle 5-like (Cdc5L), as a pre-mRNA splicing factor, is a regulator of mitotic progression. Previous study found that deletion of endogenous Cdc5L decreases the cell viability via dramatic mitotic arrest, while the role of Cdc5L in cancer biology remains under debate. AIMS: To investigate the involvement of Cdc5L in the progression of hepatocellular carcinoma (HCC). METHODS: In this study, the expression of Cdc5L was evaluated by Western blot in 8 paired fresh HCC tissues and immunohistochemistry on 116 paraffin-embedded slices. We treated HCC cells by nocodazole to analyze the role of Cdc5L in mitotic progress. To determine whether Cdc5L could regulate the proliferation of HCC cells, we increased endogenous Cdc5L and analyzed the proliferation of HCC cells using Western blot, CCK8, flow cytometry assays, and colony formation analyses. Furthermore, Cdc5L-siRNA oligos were used to confirm that Cdc5L plays an essential role in HCC development. RESULTS: Cdc5L was highly expressed in HCC and significantly associated with multiple clinicopathological factors, including AJCC stage, tumor size, and Ki-67. Besides, univariate and multivariate survival analyses demonstrated that high Cdc5L expression was an independent prognostic factor for HCC patients' poor survival. Overexpression of Cdc5L favors cell cycle progress of HCC cells, while downregulation of Cdc5L results in cell cycle arrest at G2/M phase and reduced cell proliferation of HCC cells. CONCLUSIONS: Our findings suggested that Cdc5L could play an important role in the tumorigenesis of HCC and thus be a potential therapeutical target to prevent HCC progression.