Protein expression profiling identifies cyclophilin A as a molecular target in Fhit-mediated tumor suppression

Radiation-Induced Reactions in The Liver - Modulation of Radiation Effects by Lifestyle-Related Factors

Radiation has a wide variety of effects on the liver. Fibrosis is a concern in medical fields as one of the acute effects of high-dose irradiation, such as with cancer radiotherapies. Cancer is also an important concern following exposure to radiation. The liver has an active metabolism and reacts to radiations. In addition, effects are modulated by many environmental factors, such as high-calorie foods or alcohol beverages. Adaptations to other environmental conditions could also influence the effects of radiation. Reactions to radiation may not be optimally regulated under conditions modulated by the environment, possibly leading to dysregulation, disease or cancer. Here, we introduce some reactions to ionizing radiation in the liver, as demonstrated primarily in animal experiments. In addition, modulation of radiation-induced effects in the liver due to factors such as obesity, alcohol drinking, or supplements derived from foods are reviewed. Perspectives on medical applications by modulations of radiation effects are also discussed.

FHIT down-regulation was inversely linked to aggressive behaviors and adverse prognosis of gastric cancer: a meta- and bioinformatics analysis

FHIT (fragile histine triad) acts as diadenosine P1, P3-bis (5'-adenosyl)-triphosphate adenylohydrolase involved in purine metabolism, and induces apoptosis as a tumor suppressor. We performed a systematic meta- and bioinformatics analysis through multiple online databases up to March 14, 2017. The down-regulated FHIT expression was found in gastric cancer, compared with normal mucosa and dysplasia (p < 0.05). FHIT expression was negatively with depth of invasion, lymph node metastasis, distant metastasis, TNM staging and dedifferentiation of gastric cancer (p < 0.05). A positive association between FHIT expression and favorable overall survival was found in patients with gastric cancer (p < 0.05). According to Kaplan-Meier plotter, we found that a higher FHIT expression was negatively correlated with overall and progression-free survival rates of all cancer patients, even stratified by aggressive parameters (p < 0.05). These findings indicated that FHIT expression might be employed as a potential marker to indicate gastric carcinogenesis and subsequent progression, even prognosis.

Downregulation of Peptidylprolyl isomerase A promotes cell death and enhances doxorubicin-induced apoptosis in hepatocellular carcinoma

Peptidylprolyl isomerase A (PPIA) is a peptidyl-prolyl cis-trans isomerase that is known to play a critical role in the development of many human cancers. However, the precise biological function of PPIA in hepatocellular carcinoma (HCC) remains largely unclear. In this study, lentiviral overexpression vectors and small interfering RNA knockdown methods were employed to investigate the biological effects of PPIA in HCC. PPIA levels in HCC tissues and peritumoral tissues were detected by real-time Polymerase Chain Reaction (RT-PCR), Western blotting, and immunohistochemistry. Our results indicate that PPIA levels were significantly higher in the HCC tissues compared to the matched peritumoral tissues. Moreover, PPIA expression was significantly associated with tumor size in these tissues. Interestingly, serum PPIA (sPPIA) levels were significantly higher in healthy controls compared to the HCC patients. Knockdown or overexpression of PPIA was shown to downregulate and upregulate cell growth, respectively. Moreover, PPIA siRNA knockdown appears to promote doxorubicin-induced apoptosis in HCC cells, altering the expression of downstream apoptotic factors. In summary, our results indicate that PPIA may play a pivotal role in HCC by regulating cell growth and could serve as a novel marker and therapeutic molecular target for HCC patients.

Cyclophilin A as a downstream effector of PI3K/Akt signalling pathway in multiple myeloma cells

Cyclophilin A (Cyp A), a member of the peptidyl-prolyl isomerase (PPI) family, may function as a molecular signalling switch. Comparative proteomic studies have identified Cyp A as a potential downstream target of protein kinase B (Akt). This study confirmed that Cyp A is a downstream effector of the phosphatidylinositide 3-kinase (PI3K)/Akt signalling pathway. Cyp A was highly phosphorylated in response to interleukin-6 treatment, which was consistent with the accumulation of phosphorylated Akt, suggesting that Cyp A is a phosphorylation target of Akt and downstream effector of the PI3K/Akt pathway. Cyclosporine A (CsA), a PPI inhibitor, inhibited the growth of multiple myeloma (MM) U266 cells. Moreover, CsA treatment inhibited the activation of the signal transducer and activator of transcription 3 (STAT3) in MM U266 cells. Several Cyp A mutants were generated. Mutants with mutated AKT phosphorylation sites increased the G1 phase arrest in MM U266 cells. The other mutants that mimicked the phosphorylated state of Cyp A decreased the percentage of G1 phase. These results demonstrated that the states of phosphorylation of Cyp A by Akt can influence the progress of the cell cycle in MM U266 cells and that this effect is probably mediated through the Janus-activated kinase 2/STAT3 signalling pathway.

Cyclophilin A: a key player for human disease

Cyclophilin A (CyPA) is a ubiquitously distributed protein belonging to the immunophilin family. CyPA has peptidyl prolyl cis-trans isomerase (PPIase) activity, which regulates protein folding and trafficking. Although CyPA was initially believed to function primarily as an intracellular protein, recent studies have revealed that it can be secreted by cells in response to inflammatory stimuli. Current research in animal models and humans has provided compelling evidences supporting the critical function of CyPA in several human diseases. This review discusses recently available data about CyPA in cardiovascular diseases, viral infections, neurodegeneration, cancer, rheumatoid arthritis, sepsis, asthma, periodontitis and aging. It is believed that further elucidations of the role of CyPA will provide a better understanding of the molecular mechanisms underlying these diseases and will help develop novel pharmacological therapies.

Impact of cisplatin administration on protein expression levels in renal cell carcinoma: a proteomic analysis

Renal cell carcinoma (RCC) is the most common renal neoplasm in adults. Considering that chemoresistance is a typical feature of RCC, every effort should be made in order to identify mechanisms of drug resistance. We used two-dimensional gel electrophoresis and mass spectrometry to study changes in protein expression levels that occur in primary resistant LN78 RCC cells when treated with therapeutic concentrations of cisplatin. Expression differences of selected proteins were confirmed by immunoblot. Up-regulation of heat-shock proteins can block apoptosis indirectly by altered protein folding and by direct interaction with apoptosis regulatory proteins. Cyclophilin A and stratifin can modify cell cycle control and enable tumor cells to escape and further proliferate despite DNA damage caused by cisplatin. Increased activity of glycolytic enzymes reflect metabolic adaptations to increased energy requirements as well as converting to alternative energy sources because of cisplatin-induced disturbed mitochondrial oxidation. Changes in cytoskeletal proteins may change the handling of cisplatin by altering transport and increasing cellular efflux of the drug. Repression of vimentin and disturbance of antioxidative mechanisms may represent vulnerable points in tumor cellular defense against cisplatin. The involvement of these proteins in cisplatin resistance and their potential as therapeutic targets requires further evaluation.

An Overview of Cyclophilins in Human Cancers

Cyclophilins (Cyps) belong to a group of proteins that have peptidyl-prolyl cis–trans isomerase (PPIase) and molecular chaperone activities. Originally, Cyps were identified as the intracellular receptors for the immunosuppressive drug cyclosporin A. Cyps are found in all prokaryotes and eukaryotes, and have been structurally conserved throughout evolution, implying their importance in cellular function. There are seven major Cyp isoforms in humans. CypA is up-regulated in many human cancers, and there is a strong correlation between over-expression of the CYPA gene and malignant transformation in some cancers. Moreover, CypA is directly under the transcriptional control of two critical transcription factors for cancer development: p53 and hypoxia inducible factor-1α. This review discusses the general biological functions of Cyps under a variety of stress conditions, and the importance and diverse roles of over-expression of CYP genes in human cancers, with a particular emphasis on CYPA. These oncogenic properties suggest that CypA is a promising target for cancer therapy.

Analysis of newly established EST databases reveals similarities between heart regeneration in newt and fish

BACKGROUND

The newt Notophthalmus viridescens possesses the remarkable ability to respond to cardiac damage by formation of new myocardial tissue. Surprisingly little is known about changes in gene activities that occur during the course of regeneration. To begin to decipher the molecular processes, that underlie restoration of functional cardiac tissue, we generated an EST database from regenerating newt hearts and compared the transcriptional profile of selected candidates with genes deregulated during zebrafish heart regeneration.

RESULTS

A cDNA library of 100,000 cDNA clones was generated from newt hearts 14 days after ventricular injury. Sequencing of 11520 cDNA clones resulted in 2894 assembled contigs. BLAST searches revealed 1695 sequences with potential homology to sequences from the NCBI database. BLAST searches to TrEMBL and Swiss-Prot databases assigned 1116 proteins to Gene Ontology terms. We also identified a relatively large set of 174 ORFs, which are likely to be unique for urodele amphibians. Expression analysis of newt-zebrafish homologues confirmed the deregulation of selected genes during heart regeneration. Sequences, BLAST results and GO annotations were visualized in a relational web based database followed by grouping of identified proteins into clusters of GO Terms. Comparison of data from regenerating zebrafish hearts identified biological processes, which were uniformly overrepresented during cardiac regeneration in newt and zebrafish.

CONCLUSION

We concluded that heart regeneration in newts and zebrafish led to the activation of similar sets of genes, which suggests that heart regeneration in both species might follow similar principles. The design of the newly established newt EST database allows identification of molecular pathways important for heart regeneration.

Enlightened protein: Fhit tumor suppressor protein structure and function and its role in the toxicity of protoporphyrin IX-mediated photodynamic reaction

The Fhit tumor suppressor protein possesses Ap(3)A (diadenosine triphosphate - ApppA) hydrolytic activity in vitro and its gene is found inactive in many pre-malignant states due to gene inactivation. For several years Fhit has been a widely investigated protein as its cellular function still remains largely unsolved. Fhit was shown to act as a molecular 'switch' of cell death via cascade operating on the influence of ATR-Chk1 pathway but also through the mitochondrial apoptotic pathway. Notably, Fhit was reported by our group to enhance the overall eradication effect of porphyrin-mediated photodynamic treatment (PDT). In this review the up-to-date findings on Fhit protein as a tumor suppressor and its role in PDT are presented.

Inverse correlation of aberrant expression of fragile histidine triad (FHIT) protein with cyclin D1 protein and prognosis in Chinese patients with cholangiocarcinoma

BACKGROUND

This is the first study to explore the relationship between the expression of fragile histidine triad, FHIT and cyclin D1 proteins, and the clinicopathological significance of the two proteins in Chinese patients with cholangiocarcinoma.

MATERIAL AND METHODS

Immunohistochemistry was used to study 53 cases of cholangiocarcinoma, 30 para-neoplastic and 20 normal bile ducts for their expression status of FHIT and cyclin D1 and then the results were analyzed with the patient's age, sex, tumour site, histological grade and clinical stage as well as overall median survival time.

RESULTS

Compared with the para-neoplastic and normal cholangiocytes, the expression of FHIT was obviously decreased (p=0.0001), whereas that of cyclin D1 was significantly increased (p=0.0001) in carcinoma cells. The expression of FHIT was found to be correlated with the histological grade (p=0.007) and the clinical stage (p=0.004), but not with age (p=0.776), sex (p=0.246) or tumour site (p=0.347). The expression of cyclin D1 was also showed statistically associated with the histological grade (p=0.043) and clinical stage (p=0.047), but not with age (p=0.965), sex (p=0.751) or tumour site (p=0.948). Further, the expression of FHIT was found to be inversely correlated with the expression of cyclin D1 (p=0.0001). The loss of expression of FHIT and the expression of cyclin D1 were significantly related to the cancers with shorter median survival time (p=0.0001, p=0.0081). The expression of FHIT was an independent prognostic factor (p=0.005).

DISCUSSION

The expression of FHIT may be inversely correlated with the expression of cyclin D1. It is suggested that the loss of FHIT protein and overexpression of cyclin D1 protein may play an important role in carcinogenesis and prognosis of cholangiocarcinoma.

Effect of fragile histidine triad gene on biologic properties of muco-epidermoid carcinoma cells

BACKGROUND

The fragile histidine triad (FHIT) gene is abnormally expressed in many kinds of tumors and plays an important role in tumor development. However, the function of the FHIT gene in muco-epidermoid carcinoma (MEC) is still unknown. This study aimed to investigate the effect of exogenous FHIT gene on the biologic properties of MEC cells.

METHODS

Wild-type FHIT gene was transferred into MEC-1 cells. The in vitro proliferation, clone formation ability and apoptosis of FHIT-transfected MEC-1 cells (MEC-FHITc4) were examined by cell counting, clonal forming assay, immunochemical staining, histochemical staining, flow cytometry analysis and transmission electron microscopy. The tumorigenicity of MEC-FHITc4 cells was observed by in vivo study in nude mice.

RESULTS

In vitro study showed that the population doubling times of MEC-1 and MEC-FHITc4 cells were 21.03 h and 26.86 h, respectively. FHIT gene transfer reduced the percentage of cells in cell cycle S phase (3.8%) and kept more cells in the G(1) phase (62.4%). Additionally, the clonal forming rates of MEC-1 and MEC-FHITc4 were 17.9+/-0.87% and 12.3+/-0.02%, respectively. In a 4-week tumor growth study in nude mice, FHIT transfection suppressed the tumor growth by 70.1+/-0.38%. Interestingly, MEC-FHITc4 cells were stained more strongly with Alician Blue and Periodic Schiffs than control cells.

DISCUSSION

The FHIT gene might function to inhibit the proliferation and tumorigenicity of MEC-1 cells, and to induce the differentiation of MEC-1 cells, in vitro and in vivo.

Comparative proteomic analysis of matched primary and metastatic melanoma cell lines

Identification of the biochemical pathways involved in the transformation from primary to metastatic melanoma is an area under intense investigation. A 2DE proteomics approach has been applied herein to the matched patient primary and metastatic melanoma cell lines WM-115 and WM-266-4, respectively, to better understand the processes that underlie tumor progression. Image analysis between samples aligned 470 common gel spots. Quantitative gel analysis indicated 115 gel spots of greater intensity in the metastatic line compared with the primary one, leading to the identification of 131 proteins via database searching of nano-LC-ESI-Q-TOF-MS/MS data. This more than tripled the number of proteins previously shown to be of higher abundance during melanoma progression. Also observed were 22 gel spots to be of lesser intensity in the metastatic line with respect to the primary one. Of these gel spots 15 proteins could be identified. Numerous proteins from both groups had not been reported previously to participate in melanoma progression. Further analysis of one protein, cyclophilin A, confirmed that this protein is expressed at higher levels in metastatic melanoma compared with primary melanoma and normal fibroblasts. Overall, this study expands our knowledge of protein modulation during melanoma stages, and suggests new targets for inhibitor development.

Correlation of intracellular diadenosine triphosphate (Ap3A) with apoptosis in Fhit-positive HEK293 cells

The pro-apoptotic Fhit tumor suppressor protein binds and hydrolyses diadenosine triphosphate (Ap3A) and diadenosine tetraphosphate (Ap4A) in vitro. We have measured the level of both these nucleotides in Fhit-positive HEK293 cells exposed to various apoptosis inducers. Cold shock, anti-Fas, cadmium ions and etoposide all increased the basal level of Ap4A of 0.500pmol/10(6)cells by about 50%. However, the corresponding increases in Ap3A from a basal 0.079pmol/10(6)cells correlated closely with the degree of apoptosis produced, up to a maximum of 0.510pmol/10(6)cells with etoposide. These results support the view that Ap3A is the in vivo Fhit ligand and that an inhibition of Fhit activity is a key element in Fhit-mediated apoptosis.

Growth inhibitory effect of the human NIT2 gene and its allelic imbalance in cancers

The mammalian nitrilase (Nit) protein is a member of the nitrilase superfamily whose function remains to be characterized. We now show that the nitrilase family member 2 gene (NIT2) is ubiquitously expressed in multiple tissues and encodes protein mainly distributed in the cytosol. Ectopic expression of Nit2 in HeLa cells was found to inhibit cell growth through G(2) arrest rather than by apoptosis. Consistent with this, proteomic and RT-PCR analyses showed that Nit2 up-regulated the protein and mRNA levels of 14-3-3sigma, an inhibitor of both G(2)/M progression and protein kinase B (Akt)-activated cell growth, and down-regulated 14-3-3beta, a potential oncogenic protein. Genotype analysis in four types of primary tumor tissues showed 12.5-38.5% allelic imbalance surrounding the NIT2 locus. The results demonstrated that NIT2 plays an important role in cell growth inhibition and links to human malignancies, suggesting that Nit2 may be a potential tumor suppressor candidate.