Protein profile of human hepatocarcinoma cell line SMMC-7721: Identification and functional analysis

Dynamic Profiling of Protein Mole Synthesis Rates during C2C12 Myoblast Differentiation

Mole (MSR) and fractional (FSR) synthesis rates of proteins during C2C12 myoblast differentiation are investigated. Myoblast cultures supplemented with D₂ O during 0-24 h or 72-96 h of differentiation are analyzed by LC-MS/MS to calculate protein FSR and MSR after samples are spiked with yeast alcohol dehydrogenase (ADH1). Profiling of 153 proteins detected 70 significant (p ≤ 0.05, FDR ≤ 1%) differences in abundance between cell states. Early differentiation is enriched by clusters of ribosomal and heat shock proteins, whereas later differentiation is associated with actin filament binding. The median (first-third quartile) FSR (%/h) during early differentiation 4.1 (2.7-5.3) is approximately twofold greater than later differentiation 1.7 (1.0-2.2), equating to MSR of 0.64 (0.38-1.2) and 0.28 (0.1-0.5) fmol h^-1  µg^-1 total protein, respectively. MSR corresponds more closely with abundance data and highlights proteins associated with glycolytic processes and intermediate filament protein binding that are not evident among FSR data. Similarly, MSR during early differentiation accounts for 78% of the variation in protein abundance during later differentiation, whereas FSR accounts for 4%. Conclusively, the interpretation of protein synthesis data differs when reported in mole or fractional terms, which has consequences when studying the allocation of cellular resources.

Role of a genetic variation in the microRNA-4421 binding site of ERP29 regarding risk of oropharynx cancer and prognosis

We conducted a two-stage association study on patients with oropharynx (OP) squamous cell carcinoma (SCC) and healthy controls to identify single nucleotide variants (SNVs) located at the microRNA (miR)-binding sites of carcinogenesis genes associated with risk and prognosis of the disease. In stage 1, 49 patients and 49 controls were analyzed using Genome-Wide Human SNV Arrays to identify variants in the 3′-untranslated region (3′-UTR) of carcinogenesis-related genes, and one SNV was selected for data validation in stage 2 by TaqMan assays in 250 OPSCC patients and 250 controls. The ERP29 c.*293A > G (rs7114) SNV located at miR-4421 binding site was selected for data validation among 46 SNVs. The ERp29 and miR-4421 levels were evaluated by quantitative-PCR and Western blotting. Interaction between miR-4421 with 3′-UTR of ERP29 was evaluated by luciferase reporter assay. Event-free survival (EFS) was calculated by Kaplan–Meier and Cox methods. ERP29 GG variant genotype was more common in OPSCC patients than in controls (6.4% vs 3.6%, p = 0.02; odds ratio: 5.67; 95% confidence interval (CI) 1.27–25.26). Shorter EFS were seen in the base of tongue (BT) SCC patients with GG genotype (0.0% vs 36.2%, p = 0.01; hazard ratio: 2.31; 95% CI: 1.03–5.15). Individuals with ERP29 AG or GG genotypes featured lower levels of ERP29 mRNA (p = 0.005), ERp29 protein (p < 0.001) and higher levels of miR-4421 (p = 0.02). The miR-4421 showed more efficient binding with 3′-UTR of the variant G allele when compared with wild-type allele A (p = 0.001). Our data suggest that ERP29 rs7114 SNV may alter the risk and prognosis of OPSCC due to variation in the ERp29 production possibly modulated by miR-4421.

Differences between exhausted CD8+ T cells in hepatocellular carcinoma patients with and without uremia

The purpose of this study was to explore the differences between exhausted CD8⁺ T cells in hepatocellular carcinoma (HCC) patients with and without uremia. We enrolled 45 uremic patients who were recently diagnosed with HCC into the HCC + uremia cohort and similar patients with HCC but without uremia into the HCC-only cohort. Lymphocytes were obtained from the two cohorts, and exhausted CD8⁺ T cells, comprising PD-1⁺CD8⁺, TIM-3⁺CD8⁺, and LAG-3⁺CD8⁺ T cells, were sorted and expanded in vitro. After expansion, the proportions of PD-1⁺CD8⁺, TIM-3⁺CD8⁺, and LAG-3⁺CD8⁺ T cells were significantly higher in the HCC-only cohort than in the HCC + uremia cohort. CD8⁺ T cells expressing PD-1, TIM-3, or LAG-3 showed increased tumor reactivity and release of interferon-γ in vitro; however, these cells demonstrated weaker anti-tumor activity in HCC + uremia patients than in HCC-only patients. Among the expanded lymphocytes, only the decreased proportion of PD-1⁺CD8⁺ T cells significantly correlated with the HCC + uremia cohort (odds ratio of 2.731, p = 0.009). We concluded that peripheral CD8⁺ T cells expressing PD-1, TIM-3, or LAG-3 from the HCC + uremia cohort were dysfunctional in vitro. Among these populations, PD-1⁺CD8⁺ T cells were most evident in HCC patients with uremia.

EGFRvIII-specific CAR-T cells produced by piggyBac transposon exhibit efficient growth suppression against hepatocellular carcinoma

Adoptive cellular immunotherapy employing chimeric antigen receptors-modified T (CAR-T) cells has demonstrated promising antitumor effects in hematologic cancers. However, CAR-T therapy confront many challenges in solid tumors like immunosuppressive microenvironment, molecular heterogeneity, etc. The cancer genome atlas (TCGA) of hepatocellular carcinoma (HCC) revealed many genetic characteristic and molecular tumorigenesis. EGFRvIII is a tumor specific antigen widely expressed in a variety of cancers including HCC and an ideal therapeutic target for cancer therapy. The liver cancer cell line SMMC7721 express high level EGFRvIII and widely applied in HCC investigations. Herein, we developed EGFRvIII CAR-T cells by piggyBac transposon system, and detected its specific killing effect against SMMC7721 cells in vitro and in vivo. Results indicated that transduction efficiency of CAR reached 53.1%. Expression of CAR protein was verified by immunoblotting as a band of approximate 57KD. The killing effect of CAR-T cells against SMMC7721 was positively correlated with E/T ratio (E:T=5:1, 10:1, 20:1, 40:1), and exceeded 50% at 20:1 ratio. Significant increase in IFN-γ and TNF-α secretion were detected in the co-culture supernatant of CAR-T cells and SMMC7721, comparable to the level of exogenous EGFRvIII-expressing U87 cells. The killing activity and cytokine secretion were both dependent on the expression level of EGFRvIII in target cells. In HCC xenograft models, CAR-T cells could effectively suppress the growth of SMMC7721. In conclusion, EGFRvIII CAR-T cells demonstrated specific antitumor effect against SMMC7721 in vitro and in vivo, providing basis for immunotherapy of HCC in future clinical use.

The ‘mitochondrial contact site and cristae organising system’ (MICOS) in health and human disease

The ‘mitochondrial contact site and cristae organising system’ (MICOS) is an essential protein complex that promotes the formation, maintenance and stability of mitochondrial cristae. As such, loss of core MICOS components disrupts cristae structure and impairs mitochondrial function. Aberrant mitochondrial cristae morphology and diminished mitochondrial function is a pathological hallmark observed across many human diseases such as neurodegenerative conditions, obesity and diabetes mellitus, cardiomyopathy, and in muscular dystrophies and myopathies. While mitochondrial abnormalities are often an associated secondary effect to the pathological disease process, a direct role for the MICOS in health and human disease is emerging. This review describes the role of MICOS in the maintenance of mitochondrial architecture and summarizes both the direct and associated roles of the MICOS in human disease.

Columbamine suppresses hepatocellular carcinoma cells through down-regulation of PI3K/AKT, p38 and ERK1/2 MAPK signaling pathways

Hepatocellular carcinoma (HCC) as primary liver cancer in adults is the most common cause led to internal cirrhosis responsible for patients' death, which resulted in nearly a million deaths worldwide on both males and females in the developing and developed countries. Unfortunately, up to date, there are no highly effective treatment of medicine on HCC as lack of comprehensive cellular and molecular mechanism. According to the sources of human ancient history of medicine, traditional medicine could provide unique treatment to discontinue the challenging HCC. In this study, we inspected the effect of Columbamine (Col; C20H21NO5), an alkaloid isolated from calumba, on HCC utilizing three HCC cell-lines i.e. SMMC7721, HepG2 and Hep3B. Our data collected from these cell-lines exhibit strong Col suppression on the cell growth accompanying the dosage-dependent suppression, and we further confirmed the suppression on the tumor-growth in animal model. Rational of the Col suppression presents cellular mechanism by limiting the proliferation and colony formation of the cells marked with decreased expression of PCNA. Meanwhile decreases of migration indicated with increasing expression of E-cadherin and decreasing expression of N-cadherin, and of invasion labelled with decreasing expressions of MMP2 and MMP9, are accompanying the Col suppression along with the Col promoted apoptosis of the tumor cells. This programmed cell death marketed with cleaved Caspase 3 plus PAPR proteins, up-regulation of BAD and down-regulation of BCL2 is linked the Col suppression to unique calcium-related pathways. Our results unveiled that the Columbamine suppression on HCC based on the traditional medicine are clearly associated with PI3K/AKT, p38 and ERK1/2 MAPKs signaling pathways and guide further research orientation for developing the Col medicine against hepatocellular carcinoma.

Mitochondrial inner membrane protein, Mic60/mitofilin in mammalian organ protection

The identification of the mitochondrial contact site and cristae organizing system (MICOS) in the inner mitochondrial membrane shed light on the intricate components necessary for mitochondria to form their signature cristae in which many protein complexes including the electron transport chain are localized. Mic60/mitofilin has been described as the core component for the assembly and maintenance of MICOS, thus controlling cristae morphology, protein transport, mitochondrial DNA transcription, as well as connecting the inner and outer mitochondrial membranes. Although Mic60 homologs are present in many species, mammalian Mic60 is only recently gaining attention as a critical player in several organ systems and diseases with mitochondrial-defect origins. In this review, we summarize what is currently known about the ever-expanding role of Mic60 in mammals, and highlight some new studies pushing the field of mitochondrial cristae organization towards potentially new and exciting therapies targeting this protein.

Qualitative detection of ginsenosides in brain tissues after oral administration of high-purity ginseng total saponins by using polyclonal antibody against ginsenosides

Given the limited studies and conflicting findings, the transport character of ginsenosides crossing the blood-brain barrier (BBB) remains unclear. The present study was designed to qualitatively determine the distribution of ginsenosides in brain tissues after oral administration of ginseng total saponins, using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with immunohistochemistry. In brain tissue homogenates, ginsenoside Rg1 was detectable and no other ginsenosides or their metabolites were found. No ginsenosides were detected in cerebrospinal fluid. Immunohistochemistry staining of brain tissue sections by using anti-ginsenoside polyclonal antibodies revealed the localization of ginsenosides in brain tissues. Furthermore, immunofluorescence double staining revealed that ginsenosides widely existed in vascular endotheliocytes and astrocytes, and in few neurons. These results indicated that Rg1 was the main component that entered the brain after oral administration of ginseng total saponins and that ginsenosides could cross the BBB, although the transport capability of ginsenosides through the BBB may be poor.

Identification of cellular genes and pathways important for tumorigenicity of hepatocellular carcinoma cell lines by proteomic profiling

Hepatocellular carcinoma (HCC) is the most commonly diagnosed malignancy of the liver. A more thorough understanding of HCC pathogenesis will provide novel targets for development of cancer drugs to effectively treat HCC. To further this goal, we carried out a proteomic profiling of HCC cell lines Huh-7.4 and Huh-7.5. These two cell lines were derived from subgenomic HCV RNA-replicating Huh-7 cells upon clearance of HCV RNA by antiviral drug treatment. Initially, the tumorigenicity of each cell line was determined and compared in parallel in the same immunedeficient mice. Strikingly, the Huh-7.4 cell line was able to induce tumors, whereas the Huh-7.5 cell line failed to do so, providing unique model systems for identifying cellular genes and pathways important for HCC development and progression. Subsequently, one-dimensional LC-MS/MS proteomic and bioinformatics analyses were performed in the hope of identifying unique cellular genes and pathways responsible for HCC tumorigenicity. Interestingly, a total of 130 cellular genes were found to be significantly up- or downregulated between these two cell lines (r>3 fold, P<0.001). Also, EIF (EIF2&4), mTOR/p70S6K, ERK5, and EGFR signaling pathways were significantly different. Overall, these results provide significant new information to shed light on the underlying biological processes involved in HCC development and progression.

Identification of specific biomarkers for gastric adenocarcinoma by ITRAQ proteomic approach

The aim of this study was to identify biomarkers for gastric cancer (GC) by iTRAQ. Using proteins extracted from a panel of 4 pairs of gastric adenocarcinoma samples (stage III-IV, Her-2 negative), we identified 10 up regulated and 9 down regulated proteins in all four pairs of GC samples compared to adjacent normal gastric tissue. The up regulated proteins are mainly involved in cell motility, while the down regulated proteins are mitochondrial enzymes involved in energy metabolism. The expression of three up regulated proteins (ANXA1, NNMT, fibulin-5) and one of the down regulated proteins (UQCRC1) was validated by Western Blot in 97 GC samples. ANXA1 was up regulated in 61.36% of stage I/II GC samples compared to matched adjacent normal gastric tissue, and its expression increased further in stage III/IV samples. Knockdown of ANXA1 by siRNA significantly inhibited GC cell migration and invasion, whereas over expression of ANXA1 promoted migration and invasion. We found decreased expression of UQCRC1 in all stages of GC samples. Our data suggest that increased cell motility and decreased mitochondrial energy metabolism are important hallmarks during the development of GC.

Diagnostic and prognostic significance of serum apolipoprotein C-I in triple-negative breast cancer based on mass spectrometry

Women with triple-negative breast cancer (TNBC) have poor prognosis because of the aggressive nature of the tumor, delayed diagnosis and non-specific symptoms in the early stages. Identification of novel specific TNBC serum biomarkers for screening and therapeutic purposes therefore remains an urgent clinical requirement.We obtained serum samples from a total of 380 recruited individuals split into mining and testing sets, with the aim of screening for reliable protein biomarkers from TNBC and non-TNBC (NTNBC) sera. Samples were assessed using mass spectrometry, followed by receiver operating characteristic (ROC), survival and hazard function curve as well as multivariate Cox regression analyses to ascertain the potential of the protein constituents as diagnostic and prognostic biomarkers for TNBC.We identified upregulated apolipoprotein C-I (apoC-I) with a validated positive effect on TNBC tumorigenesis, with confirmation in an independent test set and minimization of systematic bias by pre-analytical parameters. The apoC-I protein had superior diagnostic ability in distinguishing between TNBC and NTNBC cases. Moreover, the protein presented a more robust potential prognostic factor for TNBC than NTNBC. The apoC-I protein identified in this study presents an effective novel diagnostic and prognostic biomarker for TNBC, indicating that measurement of the peak intensity at 7785 Da in serum samples could facilitate improved early detection and estimation of postoperative survival prognosis for TNBC.

Diagnostic and prognostic role of serum protein peak at 6449 m/z in gastric adenocarcinoma based on mass spectrometry

Background:

Gastric cancer (GC) is a highly aggressive cancer type associated with significant mortality owing to delayed diagnosis and non-specific symptoms observed in the early stages. Therefore, identification of novel specific GC serum biomarkers for screening purposes is an urgent clinical requirement.

Methods:

This study recruited a total of 432 serum samples from 296 GC patients split into the mining and testing sets. We aimed to screen for reliable protein biomarkers from matched serum samples based on mass spectrometry, followed by comparison with three representative conventional markers using receiver operating characteristic and survival curve analyses to ascertain their potential values as diagnostic and prognostic biomarkers for GC.

Results:

We identified an apoC-III fragment with confirmation in an independent test set from a second hospital. We found that the diagnostic ability of this fragment performed better than current standard GC diagnostic biomarkers both individually and in combination in distinguishing patients with GC from healthy individuals. Moreover, we found that this apoC-III protein fragment represents a more robust potential prognostic factor for GC than the three conventional markers.

Conclusions:

In view of these findings, we suggest that apoC-III protein fragment is a novel diagnostic and prognostic biomarker, a complement to conventional biomarkers in detecting GC.

The phospholipase A2 activity of peroxiredoxin 6 promotes cancer cell death induced by tumor necrosis factor alpha in hepatocellular carcinoma

In this study, we used proteomic profiling to compare hepatocellular carcinoma (HCC) and peri-tumoral tissues to identify potential tumor markers of HCC. We identified eight differentially expressed proteins (>3-fold), including Peroxiredoxin 6 (PRDX6). PRDX6 is a bifunctional enzyme with both peroxidase and calcium-independent phospholipase A2 (iPLA2) activity. We found that peri-tumoral tissues expressed higher levels of PRDX6 mRNA (n = 59, P = 0.018) and protein (n = 265, P < 0.001) than HCC tissues, and that decreased expression of PRDX6 in HCC tissues was an independent risk factor indicating a poor prognosis (n = 145, P = 0.007). Combining the examination of serum PRDX6 with α-fetoprotein improved the diagnostic sensitivity of tests for HCC compared to α-fetoprotein alone (85.0% vs 50.0%, n = 40). We found that PRDX6 induced S phase arrest in HCC cells and inhibited HCC tumorigenicity in mice injected with cancer cells. When treated with H2 O2 , PRDX6 inhibited apoptosis. When treated with tumor necrosis factor alpha (TNF-α), PRDX6 promoted apoptosis. Inhibition of iPLA2 activity of PRDX6 decreased the apoptosis induced by TNF-α. In conclusion, PRDX6 inhibited the carcinogenesis of HCC, and the iPLA2 activity of PRDX6 promoted cancer cell death induced by TNF-α. © 2015 Wiley Periodicals, Inc.

A novel prognostic factor for hepatocellular carcinoma: protein disulfide isomerase

BACKGROUND/AIMS

Protein disulfide isomerase (PDI) has been implicated in the survival and progression of some cancer cells, by compensating for endoplasmic reticulum stress by upregulating the protein-folding capacity. However, its prognostic role in patients with hepatocellular carcinoma (HCC) has not been investigated.

METHODS

We collected HCC tissues from 83 HCC patients who underwent surgical resection for an immunohistochemical study of PDI. Overall survival (OS) was measured from the date of surgical resection until the date of death from any cause. Radiological progression was evaluated using the modified Response Evaluation Criteria in Solid Tumors in an independent radiological assessment.

RESULTS

PDI expression was found to be increased in human HCC compared to adjacent nontumor tissues. Increased immunopositivity for PDI was associated with a high Edmondson-Steiner grade (p = 0.028). Univariate analysis of patients who had undergone surgical resection for HCC showed that tumor PDI upregulation is a significant risk factor for poor OS (p = 0.016; hazard ratio [HR], 1.980) and time to progression (TTP; p = 0.007; HR, 1.971). Multivariate analyses revealed that high PDI expression was an independent predictor of a shorter TTP (p = 0.015; HR, 1.865) and poor OS (p = 0.012; HR, 2.069).

CONCLUSIONS

Upregulated PDI expression is associated with aggressive clinicopathological features of HCC; thus, PDI might serve as an independent prognostic factor and a potential therapeutic target for HCC patients.

Anti-metastatic and differential effects on protein expression of epigallocatechin-3-gallate in HCCLM6 hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third highest cause of cancer-related mortality in humans. Epigallocatechin-3-gallate (EGCG) has been shown to inhibit the metastatic activity of certain cancer cells. The aim of this study was to determine the effects and molecular mechanism(s) of action of EGCG in human HCC cells. A migration and invasion assay for the metastatic behavior of HCCLM6 cells was performed. The anti-metastatic effects of EGCG were investigated by RT-PCR and gelatin zymography. A total cellular protein profile was obtained using 2-dimensional gel electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) analyses of proteins with significant differences in expression following treatment with EGCG. The results revealed that EGCG induced apoptosis and inhibited the metastasis of HCCLM6 cells. The anti-metastatic effects of EGCG were associated with the inhibition of matrix metalloproteinase (MMP)-2 and MMP-9 activity. The expression levels of far upstream element (FUSE) binding protein 1 (FUBP1), heat shock protein beta 1 (HSPB1), heat shock 60 kDa protein 1 (chaperonin) (CH60) and nucleophosmin (NPM) proteins, which are associated with metastasis, were significantly altered in the EGCG-treated HCCLM6 cells. The data from the present study suggest that EGCG has potential as a therapeutic agent for the treatment of HCC.

Effects of Gekko sulfated polysaccharide-protein complex on the defective biorheological characters of dendritic cells under tumor microenvironment

We previously isolated a sulfated polysaccharide-protein complex from Gekko swinhonis Guenther, a traditional Chinese medicine, and have demonstrated its direct anti-cancer effect on human hepatocellular carcinoma cell line SMMC-7721. Here we investigated the effects of Gekko sulfated polysaccharide-protein complex (GSPP) on the defective biorheological characters of dendritic cells (DCs) under SMMC-7721 microenvironment. Our findings have shown that the biorheological properties of DCs were severely impaired by SMMC-7721 microenvironment, including decreased cell deformability, migration, and electrophoresis mobility, increased osmotic fragilities, and changed organizations of cytoskeletal proteins. We also found decreased secretion of interleukin (IL)-12 and increased secretion of IL-10 in DCs. However, supernatant collected from nonmalignant liver cells had no effect on these parameters. SMMC-7721 cells were treated with GSPP and the supernatant was used to culture DCs. We found that the defective biorheological parameters of DCs, except for osmotic fragility, were partially or completely improved. The secretion of IL-12 did not change as compared with that of DCs in SMMC-7721 microenvironment, but the secretion of IL-10 was resumed to the control level. Our results indicate that GSPP could partially restore the defective biorheological characteristics of DCs via modifying the tumor microenvironment and decreasing the secretion of IL-10 of DCs.

Enhancement of hexokinase II inhibitor-induced apoptosis in hepatocellular carcinoma cells via augmenting ER stress and anti-angiogenesis by protein disulfide isomerase inhibition

3-bromopyruvate (3-BP), a hexokinase (HK) II inhibitor, promotes tumor cell death by inducing endoplasmic reticulum (ER) stress in human hepatocellular carcinoma (HCC) cell lines. Protein disulfide isomerase (PDI) is an essential folding catalyst and attenuates ER stress by folding the misfolded proteins. We examined if PDI is expressed in hypoxic HCC cells, and evaluated its inhibition potentiated HK II inhibitor-induced ER stress in hypoxic HCC cells. HCC apoptotic cell death was assessed by DAPI staining and apoptotic signaling pathways were explored by immunoblot analysis. An in vivo model of HCC was established in C3H mice intradermally with implanted MH134 cells. 3-BP with/without a PDI inhibitor (bacitracin) was subsequently administered. The anti-tumor efficacies were evaluated by measuring tumor volumes and quantifying apoptotic cells and microvessel densities (MVDs). HCC cells were found to express PDI in a hypoxia-inducible manner. The simultaneous treatment of bacitracin and 3-BP enhanced 3-BP-induced apoptosis. This enhancement was attributed to increased ER stress and JNK activation compared to the cells treated with just 3-BP. In an in vivo model of HCC, tumor growth was significantly suppressed in mice co-treated with bacitracin and 3-BP, and the percentages of apoptotic cells significantly increased and MVDs significantly decreased. These results demonstrated that PDI was induced in hypoxic HCC tissue and that PDI inhibition enhanced HK II inhibitor-induced anti-tumor efficacy synergistically via augmenting ER stress and anti-angiogenesis in vivo. Thus, blockage of PDI activity in combination with HK II inhibitor may be therapeutically useful in HCCs.

Alpha-1 antitrypsin is a potential biomarker for hepatitis B

BACKGROUND

Function exertion of specific proteins are key factors in disease progression, thus the systematical identification of those specific proteins is a prerequisite to understand various diseases. Though many proteins have been verified to impact on hepatitis, no systematical protein screening has been documented to hepatitis B virus (HBV) induced hepatitis, hindering the comprehensive understanding to this severe disease.

AIM

To identify the major proteins in the progression of HBV infection from mild stage to severe stage.

METHODS

We performed an integrated strategy by combining two-dimensional electrophoresis (2-DE), peptide mass fingerprinting (PMF) analysis, and tissue microarray techniques to screen the functional proteins and detect the localization of those proteins.

RESULTS

Interestingly, MS/MS identification revealed the expression level of alpha-1 antitrypsin (AAT) was significantly elevated in serum samples from patients with severe chronic hepatitis. Immunoblotting with a specific AAT antibody confirmed that AAT is highly expressed in serum samples from patients with hepatic carcinoma and severe chronic hepatitis. Furthermore, we observed that AAT is with highest expression in normal tissue and cells, but lowest in hepatic carcinoma and severe chronic hepatitis tissues and cells, suggesting the specific secretion of AAT from tissues and cells to serum.

CONCLUSION

These results suggest the possibility of AAT as a potential biomarker for hepatitis B in diagnosis.

Mitochondrial proteomics analysis of tumorigenic and metastatic breast cancer markers

Mitochondria are key organelles in mammary cells responsible for several cellular functions including growth, division, and energy metabolism. In this study, mitochondrial proteins were enriched for proteomics analysis with the state-of-the-art two-dimensional differential gel electrophoresis and matrix-assistant laser desorption ionization-time-of-flight mass spectrometry strategy to compare and identify the mitochondrial protein profiling changes between three breast cell lines with different tumorigenicity and metastasis. The proteomics results demonstrate more than 1,500 protein features were resolved from the equal amount pooled from three purified mitochondrial proteins, and 125 differentially expressed spots were identified by their peptide finger print, in which, 33 identified proteins belonged to mitochondrial proteins. Eighteen out of these 33 identified mitochondrial proteins such as SCaMC-1 have not been reported in breast cancer research to our knowledge. Additionally, mitochondrial protein prohibitin has shown to be differentially distributed in mitochondria and in nucleus for normal breast cells and breast cancer cell lines, respectively. To sum up, our approach to identify the mitochondrial proteins in various stages of breast cancer progression and the identified proteins may be further evaluated as potential breast cancer markers in prognosis and therapy.

Current advances in tumor proteomics and candidate biomarkers for hepatic cancer

Tumor proteomics apply proteomics techniques to tumor biological research, mainly by screening candidate biomarkers for early tumor diagnosis, prognosis and treatment. Hepatocellular carcinoma (HCC) is a type of malignant tumor with one of the highest death rates in the world. With the advent of the post-genomic age, tumor biological research developing the technology of proteomics has become a major focus of researchers. The discovery of novel candidate biomarkers is one of crucial problems for the early diagnosis of HCC. In general, there are three distinct types of candidate biomarkers for HCC based on different areas: biochemical biomarkers, antigenic biomarkers and epigenetic biomarkers. This review mainly discusses current advances in the problems and prospects of candidate biomarker for the early diagnosis of HCC, discovered by technologies of tumor proteomics.

Comparative proteomic analysis of osteosarcoma cell and human primary cultured osteoblastic cell

To identify new biomarkers that facilitate the accurate early diagnosis of osteosarcoma and that may possibly include novel therapeutic candidates, we performed a proteomic approach to compare osteosarcoma cells and human primary cultured osteoblastic cells. Image analysis of silver-stained 2-DE gels revealed that the level of 12 protein spots was significantly different between the two groups of samples (p < .004). After mass spectroscopic identification and database searches, we found that in osteosarcoma cells, the level of HSP70, actin capping protein, ATP synthase, Mthsp75, UQCRC1, Ras-related nuclear protein, UCH-L1, and PRDX4 was elevated. However, the level of pyruvate dehydrogenase E1, Prohibitin, and Annexin V was decreased. Subsequent Western blot analyses of UQCRC1, UCH-L1, and PRDX4 in osteosarcoma tissues confirmed the results obtained by the proteomic analyses. These identified proteins may be potential molecular targets for osteosarcomatous diagnostics and therapeutics.

Systematic identification of genes involved in divergent skeletal muscle growth rates of broiler and layer chickens

Background

The genetic closeness and divergent muscle growth rates of broilers and layers make them great models for myogenesis study. In order to discover the molecular mechanisms determining the divergent muscle growth rates and muscle mass control in different chicken lines, we systematically identified differentially expressed genes between broiler and layer skeletal muscle cells during different developmental stages by microarray hybridization experiment.

Results

Taken together, 543 differentially expressed genes were identified between broilers and layers across different developmental stages. We found that differential regulation of slow-type muscle gene expression, satellite cell proliferation and differentiation, protein degradation rate and genes in some metabolic pathways could give great contributions to the divergent muscle growth rates of the two chicken lines. Interestingly, the expression profiles of a few differentially expressed genes were positively or negatively correlated with the growth rates of broilers and layers, indicating that those genes may function in regulating muscle growth during development.

Conclusion

The multiple muscle cell growth regulatory processes identified by our study implied that complicated molecular networks involved in the regulation of chicken muscle growth. These findings will not only offer genetic information for identifying candidate genes for chicken breeding, but also provide new clues for deciphering mechanisms underlining muscle development in vertebrates.

Comparative proteomics analysis of human gastric cancer

AIM: To isolate and identify differentially expressed proteins between cancer and normal tissues of gastric cancer by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

METHODS: Soluble fraction proteins of gastric cancer tissues and paired normal tissues were separated by 2-DE. The differentially expressed proteins were selected and identified by MALDI-TOF-MS and database search.

RESULTS: 2-DE profiles with high resolution and reproducibility were obtained. Twenty-three protein spots were excised from sliver staining gel and digested in gel by trypsin, in which fifteen protein spots were identified successfully. Among the identified proteins, there were ten over-expressed and five under-expressed proteins in stomach cancer tissues compared with normal tissues.

CONCLUSION: In this study, the well-resolved, reproducible 2-DE patterns of human gastric cancer tissue and paired normal tissue were established and optimized and certain differentially-expressed proteins were identified. The combined use of 2-DE and MS provides an effective approach to screen for potential tumor markers.

Low intensity ultrasound-induced apoptosis in human gastric carcinoma cells

AIM: To investigate the low intensity ultrasound (US)-induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma.

METHODS: Human SGC-7901 gastric carcinoma cells were cultured in vitro and irradiated by low intensity US for 10 min at different intensities with different incubation times after irradiation. Morphologic changes were examined under microscope with trypan blue staining and then the percentage of early apoptotic cells was detected by flow cytometry (FCM) with double staining of fluorescein isothiocyanate (FITC)-Annexin V/propidium iodide (PI). Two-dimensional electrophoresis (2DE) was used to get the protein profile and some proteins differently expressed after US irradiation were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Functional analysis was performed to investigate the mechanism of US-induced cell apoptosis.

RESULTS: The percentage of apoptotic cells increased about 10% after US irradiation (12.0 W/cm², 12 h culture). The percentage of early apoptosis and secondary necrosis in the US-irradiated cells increased with the increased US intensity. Moreover, apoptotic cells increased with the increased culture time after US irradiation and reached its maximum at about 12 h. Several new proteins appeared after US irradiation and were up or down regulated more than 2 times. Some heat shock proteins (HSPs) were found to be associated with the signal process simulating the apoptosis of cells.

CONCLUSION: Low intensity US could induce apoptosis in human gastric carcinoma cells. US-induced apoptosis is related to US intensity/culture time. US-induced apoptosis may be caspases-dependent and endoplasmic reticulum (ER) stress-triggered apoptosis may also contribute to it. Proteomic experimental system is useful in finding the protein alteration in carcinoma cells after US irradiation, helping to develop a new cancer therapy.

Differential expression of proteins in intrahepatic cholangiocarcinoma cell line ICC-9810 and liver cell line L02

AIM: To analyze the differential expression of proteins in intrahepatic cholangio-carcinoma cell line ICC-9810 and normal liver cell line L02, and to screen the potential molecular markers for the diagnosis of intrahepatic cholangiocarcinoma.

METHODS: Surface enhanced laser desorption/ionization (SELDI) mass spectrometry with ProteinChip IMAC3 and WCX2 was performed to compare the expressed proteins in intrahepatic cholangiocarcinoma cell line ICC-9810 and normal liver cell line L02. Protein profiling was examined with a PBSII-C ProteinChip reader and proteome data were analyzed using Proteinchip Software 3.0.2.

RESULTS: ProteinChip IMAC3 and WCX2 captured all the 376 protein peaks in ICC-9810 and L02 cell lines. Among the identified 27 differential proteins in ICC-9810 cell line, 9 showed a higher expression and 18 a lower expression as compared with L02 cell line. Six proteins, namely 3767, 7999, 10555, 12163, 22066 and 26794 Da, were conjointly detected by IMAC3 and WCX2 ProteinChip.

CONCLUSION: Expression of proteins is different in intrahepatic cholangiocarcinoma cells and normal liver cells. These differentially expressed proteins can be used as candidate biomarkers of intrahepatic cholangiocarcinoma and provide insights into the pathogenesis of intrahepatic cholangiocarcinoma.