Cellular apoptosis susceptibility protein and proliferation in human hepatocellular carcinoma

The cellular apoptosis susceptibility protein (CAS) is the human homologue of the product of the essential yeast chromosome segregation gene, CSE1, and has important roles in tumor necrosis factor (TNF)-induced apoptosis and cell proliferation. In this study, we used immunoblotting and immunohistochemistry to look at CAS expression in human hepatocellular carcinoma (HCC) cells. We also studied the correlation between CAS expression and cell proliferation. To do this, we studied the expression of proliferating cell nuclear antigen (PCNA) by immunostaining and at apoptosis by in situ nick end-labeling (TUNEL), followed by calculation of the PCNA labeling index (PCNA LI) and TUNEL labeling index (TUNEL LI). CAS was constitutively expressed in human HCC cell lines and was primarily confined to the cytoplasm of the cells. PCNA LI and TUNEL LI were significantly higher in HCC than in non-tumor tissue (p<0.01); however, the ratio of TUNEL LI/PCNA LI in HCC was significantly lower than that of non-tumor tissue. Immunohistochemistry revealed that the staining intensity score of CAS in HCC was significantly higher than that of non-tumor tissue (p<0.05). These results indicate that there is an augmentation of pro-liferative activity and apoptosis in HCC tissue, as compared to non-tumor tissue. There was a significant positive correlation between CAS and PCNA LI (p<0.05). In addition, we observed an inverse relationship between CAS expression and TUNEL LI, although the correlation did not reach statistical significance. These results suggest that CAS is expressed at higher levels in human HCC tissue than in non-tumor tissue. CAS may be associated with cell proliferation rather than apoptosis, and further, CAS might play an important role in the development of human HCCs.     

Over-expression of Smac promotes TRAIL-induced cell death in human hepatocellular carcinoma

The second mitochondria-derived activator of caspase, Smac, is an apoptosis-related protein. Smac releases inhibition of the IAP family from caspase-3 to induce apoptosis. Smac is expressed in some malignant tumor cells and is released from mitochondria into the cytosol after death receptor stimulation to promote apoptosis of tumor cells. In this study, we found down-regulated Smac protein expression in hepatocellular carcinoma (HCC) tissues, compared to that in non-tumor hepatic tissues. Simultaneously, caspase-3 expression also decreased in HCC tissues. HCC cell lines did not undergo apoptosis after TRAIL stimulation, although Smac was expressed in these HCC cells. Ectopic Smac alone did not induce cell death, but could sensitize HCC cells to TRAIL stimulation. With over-expression of Smac in HCC cells, TRAIL induced by 10% HCC cell death. The role of Smac in apoptosis signaling pathway in HCC cells warrants further study.     

Galectin-9 as a regulator of cellular adhesion in human oral squamous cell carcinoma cell lines

Oral squamous cell carcinomas (OSCCs), a major public health problem worldwide, are the most common neoplasms of the head and neck. The most important prognostic indicator for patients with OSCC is metastasis to cervical lymph nodes or distant organs. Galectin-9 is correlated with cellular adhesion and aggregation in melanoma cells. To investigate expression levels of galectin-9 mRNA and protein, we performed qRT-PCR and Western blot analyses on OSCC cell lines (Ca9-22, HSC-2, and HSC-3) and normal oral keratinocytes (NOKs). Galectin-9 mRNA and protein were commonly down-regulated in OSCC cell lines compared with NOKs. We further analyzed Ca9-22, which had the lowest expression of galectin-9. We then transfected the galectin-9 cDNA into Ca9-22 cells to examine whether overexpression of galectin-9 increases cellular adhesion in vitro. An adhesion assay using a fibronectin and collagen I coating plate revealed an increased cellular adherence ratio in overexpressed galectin-9 cells compared with nontransfected cells (p < 0.05). The data suggest that galectin-9 is correlated with oral cancer cell-matrix interactions and may therefore play an important role in the metastasis of OSCCs.     

Expression and prognostic role of Spy1 as a novel cell cycle protein in hepatocellular carcinoma

ObjectivesSpy1 is a novel cell cycle regulatory gene, which can control cell proliferation and survival through the atypical activation of cyclin-dependent kinases. Recent studies suggested that deregulation of Spy1 expression plays a key role in oncogenesis. To investigate the potential roles of Spy1 in hepatocellular carcinoma (HCC), expression of Spy1 was examined in human HCC samples.MethodsImmunohistochemistry and Western blot analysis was performed for Spy1 in 61 hepatocellular carcinoma samples. The data were correlated with clinicopathological features. The univariate and multivariate survival analyses were also performed to determine their prognostic significance.ResultsSpy1 was overexpressed in hepatocellular carcinoma as compared with the adjacent normal tissue. High expression of Spy1 was associated with histological grade and the level of alpha fetal protein (AFP) (P = 0.009 and 0.003, respectively), and Spy1 was positively correlated with proliferation marker Ki-67 (P < 0.001). Univariate analysis showed that Spy1 expression was associated with poor prognosis (P = 0.03). Multivariate analysis indicated that Spy1 and Ki-67 protein expression was an independent prognostic marker for HCC (P = 0.001 and 0.012, respectively). While in vitro, following release from serum starvation of HuH7 HCC cell, the expression of Spy1 was upregulated.ConclusionsOur results suggested that Spy1 overexpression is involved in the pathogenesis of hepatocellular carcinoma, it may be a favorable independent poor prognostic parameter for hepatocellular carcinoma.     

Redox activation of p21Cip1/WAF1/Sdi1: a multifunctional regulator of cell survival and death

Cell division requires the coordinated assembly of cyclins and cyclin-dependent kinases that promote cell-cycle progression through S phase and mitosis. Two families of cyclin-dependent kinase inhibitors prevent abnormal or premature proliferation by blocking cyclin kinase activity. Expression of the cyclin-dependent kinase inhibitor p21, a member of the Cip/Kip family, increases when cells are damaged. In addition to controlling cell-cycle progression, p21 participates in DNA repair and apoptotic processes. The recent appreciation that p21 regulates cell survival and death implies that it is a master regulator of cell fate. This review discusses how p21 can affect the cellular response to oxidative stress.     

Fas 抗原和caspase-8调控细菌氧化还原蛋白azurin诱导的人骨肉瘤细胞凋亡的实验研究

目的：探讨Fas抗原和caspase-8 在细菌氧化还原蛋白azurin诱导人骨肉瘤细胞凋亡中的调控机制及作用。 方法: 用150 mg/L浓度的azurin处理U2OS 细胞,分别作用6、12、24和48 h。细胞免疫化学法检测Fas 抗原的表达。用荧光试剂盒检测caspase-8 的活性。流式细胞仪检测azurin和抗-Fas-抗体诱导的骨肉瘤细胞凋亡百分率,以及加入caspase-8活性抑制剂IETD-FMK后凋亡百分率的变化。 结果: Azurin诱导U2OS 细胞凋亡后,与对照组比较,Fas 抗原表达强度增加(P<0.01)，caspase-8活性升高(P<0.01)。Fas 抗原表达和caspase-8 活性随着azurin作用时间的延长而逐渐升高,至24 h后达到高峰,然后缓慢下降,但仍显著高于对照组(P<0.01) 。Fas抗原的表达与caspase-8 活性变化呈显著正相关(r=0.873，P<0.01)。表达增强的Fas 抗原具有转导凋亡信号的功能,抗-Fas抗体借此增强azurin诱导U2OS细胞凋亡的作用。Caspase-8 活性抑制剂IETD－FMK能阻断caspase-8 活化而抑制 azurin 或抗-Fas抗体诱导的U2OS细胞凋亡,与抑制剂组比较,细胞凋亡百分率显著差异(P<0.01)。 结论： Fas 依赖途径可能为细菌氧化还原蛋白azurin诱导U2OS 细胞凋亡主要机制之一， caspase-8活性上调可能在凋亡过程中发挥重要作用。     

Interferon-γ primes macrophages for pathogen ligand-induced killing via a caspase-8 and mitochondrial cell death pathway

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巯基化Ras相关蛋白7a抑制人肝癌细胞系HepG2.2.15中HBV复制

目的探究人肝癌细胞HepG2.2.15中Ras相关蛋白7a (Rab7a)的巯基化机制及其对乙型肝炎病毒(HBV)复制的影响。方法通过生物素转换实验检测H2S对HepG2.2.15细胞中Rab7a巯基化水平的影响并验证Rab7a的巯基化位点;通过酶联免疫法、RT-qPCR和Western blot检测巯基化的Rab7a对HBV复制标志物水平的影响。结果在HepG2.2.15细胞中H2S可增强内源性Rab7a的巯基化水平(P<0.01);NaHS(H2S速释供体)可增强外源性Rab7a的巯基化表达,但其巯基化位点突变后则不受NaHS影响(P<0.01);Rab7a巯基化后,可抑制HepG2.2.15细胞上清中HBsAg、HBeAg和HBV-DNA及细胞内HBV-cccDNA、3.5kb RNA、total RNA和HBcAg蛋白的表达(P<0.05)。结论 Rab7a的巯基化抑制HBV阳性细胞系HepG2.2.15细胞中HBV的复制水平。     

The HCV core protein acts as a positive regulator of fas-mediated apoptosis in a human lymphoblastoid T cell line

Hepatitis C virus (HCV) is a major human pathogen causing mild to severe liver disease worldwide and is remarkably efficient at establishing persistent infections. Previously, we have shown that the core protein has an immunomodulatory function including the suppression of T lymphocyte responses to viral infection. To investigate the underlying mechanism for the role of core protein in immune modulation, we examined the effect of core on the sensitivity of the human T cell line, Jurkat, to Fas-mediated apoptosis. The transient and stable expression of core protein in Jurkat cells increased the sensitivity of cells to Fas-mediated apoptosis when compared to control cells expressing vector DNA alone. In addition, we demonstrated that the core protein binds to the cytoplasmic domain of Fas which may enhance the downstream signaling event of Fas-mediated apoptosis. The expression of core protein did not alter the cell surface expression of Fas, indicating that the increased sensitivity of core-expressing cells to Fas ligand was not due to upregulation of Fas. Furthermore, we observed the augmentation of caspase-3 activity in core-expressing cells. These results suggest that the core protein may promote the apoptosis of immune cells during HCV infection via the Fas signaling pathway, thus facilitating HCV persistence.     

MicroRNA-200a inhibits epithelial-mesenchymal transition in human hepatocellular carcinoma cell line

Objective: Our study investigated the role of microRNA (miR)-200a and its molecular targets in hepatocellular carcinoma (HCC) cells. Methods: An inhibitor of miR-200a was transiently transfected into the hepatocellular carcinoma cell line, MHCC-97L. The effect of this transfection on mRNA levels of epithelial-mesenchymal transition (EMT)-related genes was measured by fluorescence-based quantitative real-time polymerase chain reaction (qRT-PCR). Further, protein levels of EMT-related genes, cell proliferation and apoptosis-related markers were assessed by Western blot analysis in these transfected cells. MTT and wound-healing assay were used to evaluate the proliferation and migration of MHCC-97L cells in presence and in absence of miR-200a inhibitor. Results: Compared with miR-NC control group, qRT-PCR results in anti-miR-200a group revealed a significant reduction in the mRNA levels of E-cadherin, with a concomitant increasing in vimentin mRNA level (all P < 0.05). Western blot results showed higher E-cadherin and Caspase-3 protein expressions in anti-miR-200a group compared to miR-NC group (P < 0.05). In addition, vimentin and Ki-67 protein expression was found sharply decreased in anti-miR-200a group compared to miR-NC group (P < 0.05). Consistent with this, wound-healing and MTT assay showed that migration and proliferation capacity of MHCC-97L cells in anti-miR-200a group is significantly increased compared with miR-NC group (both P < 0.05). Conclusion: Our study reveals an important role of miR-200a in inhibiting EMT, proliferation and migration in HCC cells, suggesting the possibility of miR-200a-based therapeutics in HCC.     

Establishment and characterization of human metastatic hepatocellular carcinoma cell line

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with a poor prognosis. Recently, we established a HCC cell line from a metastatic HCC tumor. GTG banding analysis was performed and the karyotype showed that this metastatic HCC cell line is a hypertriploid (71-78 chromosomes) with a large marker chromosome containing a long homogeneously staining region (hsr). Comparative genomic hybridization was applied to characterize the chromosomal alterations in this metastatic HCC cell line. The results showed that the hsr was composed of amplified DNA sequences from 11q13. Further characterization of the hsr may lead to the isolation of the putative amplified oncogene at 11q13.     

Retinoblastoma protein prevents staurosporine-induced cell death in a retinoblastoma-defective human glioma cell line.

OBJECTIVE: To investigate the mechanism of staurosporine-induced glioma cell death and cell cycle arrest using adenovirus-mediated gene transfection, as well as the function of retinoblastoma (Rb) and genetic instability induced by staurosporine. METHODS: Cell cycle regulation, cell death and nuclear abnormalities induced by staurosporine were examined using an adenovirus vector expressing Rb, p16 or p21 genes in human glioma cell lines. RESULTS: The Rb-defective SF-539 cell line was resistant to staurosporine compared with cell lines expressing intact Rb. SF-539 glioma cells exposed to staurosporine became multinucleated and then died. Multinucleation was prevented in SF-539 cells transfected with the Rb gene, thus decreasing the death rate of these cells. CONCLUSIONS: These results imply that enforced Rb expression protects cells from genomic instability induced by staurosporine regardless of its upstream molecular effects.     

FDG PET/CT as a survival prognostic factor in patients with advanced renal cell carcinoma

Accurate prediction of the outcome of molecular target-based treatment in advanced renal cell carcinoma (RCC) is an important clinical problem. Positron emission tomography/computed tomography using [18F]-2-fluoro-2-deoxyglucose (FDG PET/CT) is a noninvasive tool for the assessment of glucose accumulation which can be a marker of the biological characteristics of the tumor. In this paper, we assess FDG PET/CT as a survival prognostic marker in patients with advanced RCC. The study included 121 patients treated in the years 2011–2016 with a diagnosis of advanced renal cell carcinoma (stage IV, multifocal metastases in all patients). Assessment using FDG PET/CT was conducted by measuring the maximum standard uptake value (SUVmax) for the marker used (the highest SUV measurement result for each patient in a single examination). SUVmax measurements were compared with various clinical risk factors used as prognostic markers. The median follow-up period was 19 months (ranging from 3 to 61 months). SUVmax measurements in all patients ranged from 1.3 to 30.0 (median 6.9). Higher SUVmax was correlated with poorer prognosis. Multi-way analysis with standard risk factors revealed that SUVmax was an independent factor for overall survival (OS; p < 0.003, hazard ratio 1.312, 95% CI 1.147–1.346). For SUVmax < 7.0, median OS was 32 months. For 7.0 ≤ SUVmax < 12.0, median OS was 12.5 months. For SUVmax ≥ 12.0, median OS was 10 months. The differences were statistically significant. A preliminary SUVmax assessment conducted using FDG PET/CT can provide information useful in the prediction of survival of patients with advanced RCC.

     

Functional screening identifies MCT4 as a key regulator of breast cancer cell metabolism and survival

Metabolic reprogramming in cancer enhances macromolecule biosynthesis and supports cell survival. Oncogenic drivers affect metabolism by altering distinct metabolic processes and render cancer cells sensitive to perturbations of the metabolic network. This study aimed to identify selective metabolic dependencies in breast cancer by investigating 17 breast cancer cells lines representative of the genetic diversity of the disease. Using a functional screen, we demonstrate here that monocarboxylate transporter 4 (MCT4) is an important regulator of breast cancer cell survival. MCT4 supports pH maintenance, lactate secretion and non‐oxidative glucose metabolism in breast cancer cells. Moreover, MCT4 depletion caused an increased dependence of cancer cells on mitochondrial respiration and glutamine metabolism. MCT4 depletion reduced the ability of breast cancer cells to grow in a three‐dimensional (3D) matrix or as multilayered spheroids. Moreover, MCT4 expression is regulated by the PI3K–Akt signalling pathway and highly expressed in HER2‐positive breast cancers. These results suggest that MCT4 is a potential therapeutic target in defined breast cancer subtypes and reveal novel avenues for combination treatment. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Inhibition of casein kinase 2 enhances the death ligand- and natural kiler cell-induced hepatocellular carcinoma cell death

Recent studies have shown that the inhibition of casein kinase 2 (CK2) sensitizes many cancer cells to Fas ligand- and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. However, it has not been demonstrated directly whether CK2 inhibition can also enhance the cytotoxicity of natural killer (NK) cells, which actually use the death ligands to kill cancer cells in vivo. To address whether NK cell-mediated cancer cell death is affected by the inhibition of CK2, we first checked whether the death ligand-induced apoptosis of hepatocellular carcinoma cells (HCCs) and HeLa were affected by CK2 inhibition. We then investigated the effect of CK2 inhibition on NK cytotoxicity against HCCs and HeLa cells and its mechanistic features. Inhibition of CK2 by emodin increased the apoptotic cell death of HepG2, Hep3B and HeLa when the cancer cell lines were treated with a soluble form of recombinant TRAIL or an agonistic antibody of Fas. This phenomenon appeared to be correlated with the expression level of death receptors on the cancer cell surface. More interestingly, the inhibition of CK2 also greatly increased the NK cell-mediated cancer cell killing. The NK cytotoxicity against the cancer cells increased about twofold when the target cells were pretreated with a specific CK2 inhibitor, emodin or 4,5,6,7-tetrabromobenzotriazole. Furthermore, the increase of the NK cytotoxicity against cancer cells by CK2 inhibition was granule-independent and mediated possibly by the death ligands on the NK cell surface. This suggests that CK2 inhibitors could be used to enhance the cytotoxicity of NK cells and consequently increase host tumour immunity.     

肝细胞癌nm23－H1蛋白表达的研究

应用免疫组化检测８８例肝细胞癌（ＨＣＣ）中ｎｍ２３－Ｈ１蛋白的表达。癌旁肝组织强阳性表达，５１例肝癌组织阳性表达（５８％）。阳性产物主要定位于肿瘤细胞胞浆。ｎｍ２３－Ｈ１蛋白表达与ＨＣＣ肿瘤体积，组织分型及Ｅｄｍｏｎｄｓｏｎ分级无关，而与肝内或肝外转移显著负相关。结果表明ｎｍ２３－Ｈ１在抑制ＨＣＣ肝内或肝外转移中起着重要作用，有可能成为评价ＨＣＣ病人预后的一项新指标。     

Involvement of survival motor neuron (SMN) protein in cell death

Infantile spinal muscular atrophy (SMA) is caused by mutations in the survival motor neuron (SMN)1 gene. We investigated the role of human (h) SMN protein on cell death in PC12 and Rat-1 cells. hSMN prolonged cell survival in PC12 cells deprived of trophic support and in Rat-1 cells induced to die by activation of the proto-oncogene c-Myc, to similar magnitude as Bcl-2 or IAP-2. While hSMN was ineffective in inhibiting apoptosis induced by ultraviolet light (UV) or etoposide treatment in proliferating PC12 or Rat-1 cells, a protective effect was observed in terminally NGF/dBcAMP-differentiated PC12 cells. hSMN inhibited the onset of apoptosis in NGF/dBcAMP-deprived or UV-treated co-differentiated PC12 cells by preventing cytochrome c release and caspase-3 activation, indicating that its effects are through suppression of the mitochondrial apoptotic pathway. Expressing hSMN deleted for exon 7 (Delta7) or for exons 6 and 7 (Delta6/7), or with the SMA point mutant Y272C, resulted in loss of survival function. Moreover, these mutants also exhibited pro-apoptotic effects in Rat-1 cells. The localization pattern of full-length hSMN in PC12 and Rat-1 cells was similar to that of endogenous SMN: granular labelling in the cytoplasm and discrete fluorescence spots in the nucleus, some of which co-localized with p80 coilin, the characteristic marker of Cajal bodies. However, cytoplasmic and nuclear aggregates were often seen with hSMNDelta7, whereas the hSMNDelta6/7 mutant showed homogenous nuclear labelling that excluded the nucleolus. Thus, our results show that the C-terminal region is critical in suppression of apoptosis by SMN.     

Apoptosis in human hepatocellular carcinoma and in liver cell dysplasia is correlated with p53 protein immunoreactivity.

AIMS: To investigate the prevalence of apoptosis in human hepatocellular carcinomas (HCC) of different types and grades and in liver cell dysplasia, and to test whether the apoptotic rate is correlated with the p53 protein status. METHODS: 37 HCC and 66 six liver samples with liver cell dysplasia were analysed for apoptosis using in situ DNA end labelling (ISEL), and for p53 protein expression by immunohistochemistry. In HCCs, proliferative activity was quantitatively assessed using proliferating cell nuclear antigen labelling. RESULTS: The apoptotic index in HCC as based on ISEL ranged from 0.1 to 13.5 per 1000 cells analysed and was not related to type or grade. No nuclear staining was observed in multinuclear tumour cells. There was a significant correlation between the apoptotic rate and both the proliferative activity and p53 protein reactivity. In liver samples containing p53 protein positive liver cell dysplasia cells, there was a significantly higher apoptotic rate of these cells. CONCLUSIONS: Apoptosis is detectable in HCC, and is not related to type and grade. There is a highly significant positive correlation between the apoptotic rate in HCC and both the proliferative activity and p53 protein expression. A similar phenomenon occurs for putative cancer precursors. The findings support the role of p53 in regulating apoptosis in preneoplastic and neoplastic liver lesions.