Differential expression of Janus kinase 3 (JAK3), matrix metalloproteinase 13 (MMP13), heat shock protein 60 (HSP60), and mouse double minute 2 (MDM2) in human colorectal cancer progression using human cancer cDNA microarrays

Heat shock protein D1 is up-regulated in various types of canine mammary tumors

Background

Mammary tumors are the most common tumors in female dogs. An early diagnosis makes the treatment easier.

Aims

The present study aimed to assess heat shock protein D1 (HSPD1) expression in canine mammary tumors.

Methods

Canine mammary tumor (CMT) samples were collected from clinics after surgery. Expression of HSPD1 transcript in CMT and apparently healthy mammary tissues was analyzed by SYBR green based real-time PCR (qRT-PCR). Further, gene encoding the immuno-dominant region of HSPD1 was cloned using the expression vector pPROEX-HTa and expressed in a prokaryotic system and recombinant HSPD1 (rHSPD1) was purified by affinity chromatography. Hyperimmune serum was raised against rHSPD1 in mice, and immunohistochemistry was standardized to assess the expression of this protein in various histotypes of canine mammary tumors.

Results

An elevated HSPD1 mRNA expression (5.973 ± 0.862 folds) was observed in canine mammary tumors. Upon purification, a 60 kDa recombinant protein was obtained and confirmed by Western blotting. In 83.3% of healthy mammary tissues, a mild/feeble HSPD1 expression was observed whereas, a strong expression of HSPD1 was seen in 80% CMT samples.

Conclusion

The findings suggested that HSPD1 could be used as a molecular marker for canine mammary tumors.

Pan-cancer analysis of Sushi domain-containing protein 4 (SUSD4) and validated in colorectal cancer

Sushi domain-containing protein 4 (SUSD4) is a complement regulatory protein whose primary function is to inhibit the complement system, and it is involved in immune regulation. The role of SUSD4 in cancer progression has largely remained elusive. SUSD4 was studied across a variety of cancer types in this study. According to the results, there is an association between the expression level of SUSD4 and prognosis in multiple types of cancer. Further analysis demonstrated that SUSD4 expression level was related to immune cell infiltration, immune-related genes, tumor heterogeneity, and multiple cancer pathways. Additionally, we validated the function of SUSD4 in colorectal cancer cell lines and found that knockdown of SUSD4 inhibited cell growth and impacted the JAK/STAT pathway. By characterizing drug sensitivity in organoids, we found that the expression of SUSD4 showed a positive correlation trend with IC50 of Selumetinib, YK-4-279, and Piperlongumine. In conclusion, SUSD4 is a valuable prognostic indicator for diverse types of cancer, and it has the potential to be a target for cancer therapy.

Effects of Nitro-Oxidative Stress on Biomolecules: Part 1-Non-Reactive Molecular Dynamics Simulations

Plasma medicine, or the biomedical application of cold atmospheric plasma (CAP), is an expanding field within plasma research. CAP has demonstrated remarkable versatility in diverse biological applications, including cancer treatment, wound healing, microorganism inactivation, and skin disease therapy. However, the precise mechanisms underlying the effects of CAP remain incompletely understood. The therapeutic effects of CAP are largely attributed to the generation of reactive oxygen and nitrogen species (RONS), which play a crucial role in the biological responses induced by CAP. Specifically, RONS produced during CAP treatment have the ability to chemically modify cell membranes and membrane proteins, causing nitro-oxidative stress, thereby leading to changes in membrane permeability and disruption of cellular processes. To gain atomic-level insights into these interactions, non-reactive molecular dynamics (MD) simulations have emerged as a valuable tool. These simulations facilitate the examination of larger-scale system dynamics, including protein-protein and protein-membrane interactions. In this comprehensive review, we focus on the applications of non-reactive MD simulations in studying the effects of CAP on cellular components and interactions at the atomic level, providing a detailed overview of the potential of CAP in medicine. We also review the results of other MD studies that are not related to plasma medicine but explore the effects of nitro-oxidative stress on cellular components and are therefore important for a broader understanding of the underlying processes.

Clinicopathologic Significance of Heat Shock Protein 60 as a Survival Predictor in Colorectal Cancer

The role of heat shock protein 60 (HSP60), a mitochondrial chaperone, in tumor progression or its anti-tumor effects remains controversial. This study aimed to confirm the possibility of using HSP60 as a prognostic marker in patients with colorectal cancer (CRC), considering TNM classification for precise prediction. HSP60 expression increased with differentiation and p53 mutations in patients. However, compared to patients with high HSP60 expression, patients with low HSP60 expression had event-free survival and disease-specific survival hazard ratios (HRs) of 1.42 and 1.69, respectively. Moreover, when the survival rate was analyzed by combining TNM classification and HSP60 expression, the prognosis was poor, particularly when HSP60 expression was low in the late/advanced stage. This pattern was also observed with HSP family D member 1, HSPD1, the gene that encodes HSP60. Low HSPD1 expression was linked to lower overall survival and relapse-free survival rates, with HRs of 1.80 and 1.87, respectively. When TNM classification and HSPD1 expression were considered, CRC patients with low HSPD1 expression and advanced malignancy had a poorer prognosis than those with high HSPD1 expression. Thus, HSPD1/HSP60 can be a useful biomarker for a sophisticated survival prediction in late- and advanced-stage CRC, allowing the design of individualized treatment strategies.

Prognostic value of JAK3 promoter methylation and mRNA expression in clear cell renal cell carcinoma

INTRODUCTION

Janus kinase 3 (JAK3) is a well-established oncogene in clear cell renal cell carcinoma (ccRCC). The methylation status of oncogene promoters has emerged as biomarkers for cancer diagnosis and prognosis.

OBJECTIVE

This study aims to investigate the biological and clinical significance of JAK3 promoter methylation in ccRCC.

METHODS

We analyzed the relationship of JAK3 promoter methylation with its mRNA expression, overall survival, and immune cell infiltration in a cohort obtained from The Cancer Genome Atlas (TCGA), which was further validated by another independent cohort. We further validated correlations of JAK3 promoter methylation with JAK3 expression, overall survival, and immune cell infiltration in an independent ccRCC cohort (Sun Yat-sen University Cancer Center (SYSUCC) cohort) by methods of immunohistochemistry (IHC) and pyrosequencing.

RESULTS

We found JAK3 promoter was significantly hypomethylated in tumor tissues compared to normal adjacent tissues in ccRCC, and JAK3 promoter hypomethylation was strongly correlated with high JAK3 mRNA expression in all three ccRCC cohorts we examined. JAK3 promoter hypomethylation predicted advanced clinicopathological characteristics and shorter overall survival (TCGA cohort and SYSUCC cohort). Furthermore, we found that JAK3 promoter methylation was significantly associated with immune cell infiltration and expression of immune checkpoint molecules (TCGA cohort and CPTAC cohort). Finally, our SYSUCC cohort validated that JAK3 promoter methylation was correlated with CD4+ and CD8+ T cell infiltration in ccRCC tumor tissues.

CONCLUSION

Our data demonstrated that the crucial role of JAK3 promoter methylation in its expression regulation and tumor microenvironment. JAK3 promoter methylation and expression are associated with clinicopathological characteristics, overall survival, and immune cell infiltration in ccRCC. We propose a rationale for further validation of JAK3 promoter methylation as a molecular biomarker for predicting responses to immune checkpoint inhibitors in ccRCC.

Restoration of miR-193a-5p and miR-146 a-5p Expression Induces G1 Arrest in Colorectal Cancer through Targeting of MDM2/p53

Purpose: Colorectal cancer (CRC) remains a universal and lethal cancer owing to metastatic and relapsing disease. Currently, the role of microRNAs has been checked in tumorigeneses. Numerous studies have revealed that between the tumor suppressor miRNAs, the reduced expression of miR-146a-5p and -193a-5p in several cancers including CRC tissues are related with tumor progression and poor prognosis of patients. The purpose of this study is to examine the role of miR-146 a-5p and -193 a-5p in CRC cell cycle progression.

Methods: The miR-193a-5p and -146 a-5p mimics were transfected into HT-29 CRC cells via jetPEI transfection reagent and their impact was assessed on p53, cyclin B, and NF-kB gene expression. The inhibitory effect of these miRNAs on cell cycle was assessed by flow cytometry. The consequence of miR-193a-5p and miR-146 a-5p on the protein expression level of Murine double minute 2 (MDM2) was assessed by western blotting.

Results: miR193a-5p and -146a-5p regulated the expression of MDM2 protein and p53, cyclin B, and NF-kB gene expression in CRC cells. Treatment of HT-29 cells with miRNA-146a-5p and -193a-5p induced G1 cell cycle arrest.

Conclusion: The findings of our study suggest that miR146a-5p and -193a-5p may act as a potential tumor suppressor by their influence on cell cycle progression in CRC cells. Thus, miRNA-146a-5p and -193a-5p restoration may be recommended as a potential therapeutic goal in the treatment of CRC patients.

Hsp60 and IL-8 axis promotes apoptosis resistance in cancer

Background

Interleukin-8 (IL-8) and heat shock protein 60 (Hsp60) play crucial roles in cell survival and maintenance of cellular homoeostasis. However, cross talks between these two proteins are not defined.

Methods

IL-8 expression in tumour tissue sections was analysed by immunohistochemistry. IL-8 expression and release in cancer cells was quantified using enzyme-linked immunosorbent assay (ELISA). Apoptosis was quantified using caspase activity and Annexin-V/PI staining.

Results

We observed IL-8 release from cancer cells in response to histone deacetylase inhibitor, apicidin (Api), and non-competitive inhibitor of the sarco/endoplasmic reticulum Ca²⁺ ATPase, thapsigargin (TG). IL-8 release was increased upon TG-treatment. TG-induced IL-8 expression was reduced in the presence of Api in Bax-dependent manner. Increased apoptosis was associated with decreased IL-8 expression in response to combined treatment of TG and Api. TG and Api combination induced caspase-8 and caspase-9 dependent apoptosis. Hsp60 knockdown abrogated IL-8 expression induced by Api, TG, and their combination. The level of TGF-β, an upstream regulator of IL-8, was decreased upon Hsp60-silencing. Knocking down Hsp60 decreased IL-8 expression and its release in prostate cancer cell xenograft tumours in SCID mice.

Conclusion

This study describes the underlying mechanism associated with apoptosis resistance mediated via Hsp60-IL-8 axis in cancer.

Hsp60 exerts a tumor suppressor function by inducing cell differentiation and inhibiting invasion in hepatocellular carcinoma

Heat shock protein 60 (Hsp60), a typical mitochondrial chaperone, is associated with progression of various cancers. However, its expression and significance in hepatocellular carcinoma (HCC) remain largely unclear. In the present study, the mRNA and protein expression of Hsp60 in HCC tissues were detected by quantitative RT-PCR (n=24), western blot (n=7), and immunohistochemical staining (n=295), respectively. The correlation between Hsp60 expression and clinicopathological characteristics of HCC patient was also analyzed. Meanwhile, the influence of Hsp60 on malignant phenotype of HCC cells was further investigated. We found that expression of Hsp60 was significantly downregulated in HCC tissues compared to peritumor tissues. Hsp60 expression was significantly correlated with serum alpha -foetoprotein (AFP) level and tumor differentiation grade. Moreover, high Hsp60 expression cancer/pericancer (C/P) ratio was associated with a better overall survival rate (P=0.035, n=295). The prognostic implication of Hsp60 in HCC was further confirmed in another cohort of 107 HCC patients (P=0.027). Up-regulation of Hsp60 remarkably induced the cell differentiation and inhibited the invasive potential of HCC in vitro and in vivo. Intriguingly, the down-regulation of Hsp60 significantly impaired mitochondrial biogenesis. Although more data are required to clarify the underling mechanism responsible for function of Hsp60, our results suggested that the effect of Hsp60 on differentiation and invasion of HCC cells might be associated with mitochondrial biogenesis. Collectively, our findings indicated that Hsp60 exerted a tumor suppressor function, and might serve as a potential therapeutic target in the treatment of HCC.

Matrix metalloproteinase-13 expression in the progression of colorectal adenoma to carcinoma : Matrix metalloproteinase-13 expression in the colorectal adenoma and carcinoma

Most colorectal carcinomas (CRCs) are considered to arise from conventional adenoma based on the concept of the adenoma-carcinoma sequence. Matrix metalloproteinases (MMPs) are known to be overexpressed as normal mucosa progresses to adenomas and carcinomas. There has been little previous investigation about MMP-13 expression in adenoma-carcinoma sequence. In this study, we aimed to investigate the immunohistochemical expression of MMP-13 in colorectal adenoma and CRC specimens using tissue microarray (TMA) technique. A total of 40 cases of CRC associated with adenoma were collected from files of the Pathology laboratory at Mansoura Gastroenterology Center between January 2007 and January 2012. Sections from TMA blocks were prepared and stained for MMP-13. Immunoreactivity to MMP-13 staining was localized to the cytoplasm of mildly, moderately, and severely dysplatic cells of adenomas and CRC tumor cells that were either homogenous or heterogeneous. There was no significant difference in MMP-13 expression between adenomas and CRCs either non-mucinous or mucinous. Adenomas with high MMP-13 expression were significantly associated with moderate to marked degree of inflammatory cellular infiltrate and presence of familial adenomatous polyps. In conclusion, MMP-13 may be a potential biological marker of early tumorigenesis in the adenoma-carcinoma sequence.

Hsp60 chaperonopathies and chaperonotherapy: targets and agents

INTRODUCTION

Hsp60 (Cpn60) assembles into a tetradecamer that interacts with the co-chaperonin Hsp10 (Cpn10) to assist client polypeptides to fold, but it also has other roles, including participation in pathogenic mechanisms.

AREA COVERED

Hsp60 chaperonopathies are pathological conditions, inherited or acquired, in which the chaperone plays a determinant etiologic-pathogenic role. These diseases justify selection of Hsp60 as a target for developing agents that interfere with its pathogenic effects. We provide information on how to proceed.

EXPERT OPINION

The information available encourages the development of ways to improve Hsp60 activity (positive chaperonotherapy) when deficient or to block it (negative chaperonotherapy) when pathogenic. Many questions are still unanswered and obstacles are obvious. More information is needed to establish when and why autologous Hsp60 becomes a pathogenic autoantigen, or induces cytokine formation and inflammation, or favors carcinogenesis. Clarification of these points will take considerable time. However, analysis of the Hsp60 molecule and a search for active compounds aimed at structural sites that will affect its functioning should continue without interruption. No doubt that some of these compounds will offer therapeutic hopes and will also be instrumental for dissecting structure-function relationships at the biochemical and biological (using animal models and cultured cells) levels.

Gut microbiota imbalance and chaperoning system malfunction are central to ulcerative colitis pathogenesis and can be counteracted with specifically designed probiotics: a working hypothesis

In this work, we propose that for further studies of the physiopathology and treatment for inflammatory bowel diseases, an integral view of the conditions, including the triad of microbiota-heat shock proteins (HSPs)-probiotics, ought to be considered. Microbiota is the complex microbial flora that resides in the gut, affecting not only gut functions but also the health status of the whole body. Alteration in the microbiota's composition has been implicated in a variety of pathological conditions (e.g., ulcerative colitis, UC), involving both gut and extra-intestinal tissues and organs. Some of these pathologies are also associated with an altered expression of HSPs (chaperones) and this is the reason why they may be considered chaperonopathies. Probiotics, which are live microorganisms able to restore the correct, healthy equilibrium of microbiota composition, can ameliorate symptoms in patients suffering from UC and modulate expression levels of HSPs. However, currently probiotic therapy follows ex-adiuvantibus criteria, i.e., treatments with beneficial effects but whose mechanism of action is unknown, which should be changed so the probiotics needed in each case are predetermined on the basis of the patient's microbiota. Consequently, efforts are necessary to develop diagnostic tools for elucidating levels and distribution of HSPs and the microbiota composition (microbiota fingerprint) of each subject and, thus, guide specific probiotic therapy, tailored to meet the needs of the patient. Microbiota fingerprinting ought to include molecular biology techniques for sequencing highly conserved DNA, e.g., genes encoding 16S RNA, for species identification and, in addition, quantification of each relevant microbe.

Heat shock proteins as danger signals for cancer detection

First discovered in 1962, heat shock proteins (HSPs) are highly studied with about 35,500 publications on the subject to date. HSPs are highly conserved, function as molecular chaperones for a large panel of “client” proteins and have strong cytoprotective properties. Induced by many different stress signals, they promote cell survival in adverse conditions. Therefore, their roles have been investigated in several conditions and pathologies where HSPs accumulate, such as in cancer. Among the diverse mammalian HSPs, some members share several features that may qualify them as cancer biomarkers. This review focuses mainly on three inducible HSPs: HSP27, HPS70, and HSP90. Our survey of recent literature highlights some recurring weaknesses in studies of the HSPs, but also identifies findings that indicate that some HSPs have potential as cancer biomarkers for successful clinical applications.

Identification and verification of heat shock protein 60 as a potential serum marker for colorectal cancer

Colorectal cancer (CRC) is a major public health issue worldwide, and novel tumor markers may contribute to its efficient management by helping in early detection, prognosis or surveillance of disease. The aim of our study was to identify new serum biomarkers for CRC, and we followed a phased biomarker discovery and validation process to obtain an accurate preliminary assessment of potential clinical utility. We compared colonic tumors and matched normal tissue from 15 CRC patients, using two-dimensional difference gel electrophoresis (2D-DIGE), and identified 17 proteins that had significant differential expression. These results were further confirmed by western blotting for heat shock protein (HSP) 60, glutathione-S-transferase Pi, α-enolase, T-complex protein 1 subunit β, and leukocyte elastase inhibitor, and by immunohistochemistry for HSP60. Using mAbs raised against HSP60, we developed a reliable (precision of 5-15%) and sensitive (0.3 ng·mL(-1)) immunoassay for the detection of HSP60 in serum. Elevated levels of HSP60 were found in serum from CRC patients in two independent cohorts; the receiver-operating characteristic curve obtained in 112 patients with CRC and 90 healthy controls had an area under the curve (AUC) of 0.70, which was identical to the AUC of carcinoembryonic antigen. Combination of serum markers improved clinical performance: the AUC of a three-marker logistic regression model combining HSP60, carcinoembryonic antigen and carbohydrate antigen 19-9 reached 0.77. Serum HSP60 appeared to be more specific for late-stage CRC; therefore, future studies should evaluate its utility for determining prognosis or monitoring therapy rather than early detection.

An association study of polymorphisms in JAK3 gene with lung cancer in the Korean population

Purpose

The genetic alteration of the janus kinases (JAKs), non-receptor tyrosine kinase, is related to the development of human cancers. However, little is known about how the sequence variation of JAK3 contributes to the development of lung cancer. This study investigated whether polymorphisms at the promoter region of the JAK3 gene are associated with the risk of lung cancer in the Korean population.

Materials and Methods

A total of 819 subjects, including 409 lung cancer patients and 410 healthy controls were recruited. The SNaPshot assay and polymerase chain reaction-restriction fragment length polymorphism analysis were used, and logistic regression analyses were performed to characterize the association between polymorphisms of JAK3 and lung cancer risk.

Results

Three polymorphisms (-672 G>A, +64 A>G and +227 G>A) of JAK3 were analyzed for large-scale genotyping (n=819). Statistical analyses revealed that polymorphisms and haplotypes in the JAK3 gene were not significantly associated with lung cancer.

Conclusion

JAK3 gene was not significantly associated with the risk of lung cancer in the Korean population.

Matrix metalloproteinase-13 is regulated by toll-like receptor-9 in colorectal cancer cells and mediates cellular migration

Matrix metalloproteinases (MMPs) are associated with cancer cell invasion and metastasis, and are currently the most prominent proteases associated with tumorigenesis. In particular, abundant expression of MMP-13 in colorectal cancer (CRC) is correlated with poor survival and the existence of distant metastasis. As suggested by recent in vitro studies, MMP-13 expression is regulated in a toll-like receptor (TLR)-9-dependent manner. In this study, we quantified the expression of MMP-13, TLR-9 and second messengers of the TLR signal transduction in CRC cells compared to colonic fibroblasts by RT-PCR. Furthermore, the effects of a selective TLR-9 stimulation on the expression of MMP-13 in CRC cells and colonic fibroblasts were analyzed. MMP-13 and TLR-9 as well as associated second messengers were simultaneously up-regulated in LS174 and SW620 cells compared to fibroblasts. Selective TLR-9 agonism with CpG oligonucleotides led to a significant increase in MMP-13 gene expression after 12 h of incubation in LS174 cells and after 12 and 24 h in SW620 cells, but not when using GpC oligonucleotides as a control substance. By contrast, MMP-13 gene expression remained unchanged in colonic fibroblasts following treatment with CpG or GpC oligonucleotides. The effects of selective MMP-13 inhibition on cellular migration were analyzed in Boyden chamber experiments. In the presence of 10 and 20 μM of the specific MMP-13 inhibitor, CL-82198, migration of the LS174 cells was significantly reduced by 55 and 52%, respectively, compared to untreated cells. In conclusion, the results of this study provide evidence of the TLR-9-dependent regulation of MMP-13 in CRC cells, but not in colonic fibroblasts. Since the specific inhibition of MMP-13 significantly reduces the migration of LS174 cells, selective MMP-13 inhibition may be a promising therapeutic strategy in CRC.

Cellular sources of MMP-7, MMP-13 and MMP-28 in ulcerative colitis

OBJECTIVE

Matrix metalloproteinases (MMPs) are considered the predominant proteases in the pathogenesis of mucosal ulcerations associated with inflammatory bowel disease (IBD). Whether the malignancy associated MMP-7 and MMP-13 or the recently cloned MMP-28 convey a certain meaning for intestinal homeostasis and pathogenesis of IBD is currently unknown. We therefore set off to analyze regulation patterns and cellular origins of these MMPs in mucosal tissues of patients with ulcerative colitis (UC).

MATERIAL AND METHODS

Biopsy samples of affected and healthy tissues were obtained from 35 Norwegian patients with UC. RNA was quantified by quantitative real-time polymerase chain reaction to study MMP gene expression in both pathological and healthy mucosal specimens. Cellular origins were determined by immunohistology using surrogate markers for inflammation, neovascularization, and epithelial structures. Protein expression of MMP-7 and MMP-13 was quantified using enzyme-linked immunosorbent assay.

RESULTS

MMP-7 and MMP-13 gene expression was significantly increased in UC affected colonic mucosa whereas MMP-28 showed a decreased expression in inflamed mucosa. Endothelial cells and infiltrating leukocytes were identified as the major cellular sources of MMP-7 and MMP-13 in UC. Enterocytes represented the major cellular source of MMP-28 in healthy and inflamed mucosa.

CONCLUSIONS

MMP-7 and MMP-13 expression in inflammatory and endothelial cells indicate a role of these MMPs for both colitis associated neoangiogenesis and inflammatory changes. Decreased MMP-28 expression in UC is most likely the result of colitis associated epithelial destruction and loss of cryptal architecture.

HSP60, a protein downregulated by IGFBP7 in colorectal carcinoma

Background

In our previous study, it was well defined that IGFBP7 was an important tumor suppressor gene in colorectal cancer (CRC). We aimed to uncover the downstream molecules responsible for IGFBP7's behaviour in this study.

Methods

Differentially expressed protein profiles between PcDNA3.1(IGFBP7)-transfected RKO cells and the empty vector transfected controls were generated by two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) identification. The selected differentially expressed protein induced by IGFBP7 was confirmed by western blot and ELISA. The biological behaviour of the protein was explored by cell growth assay and colony formation assay.

Results

Six unique proteins were found differentially expressed in PcDNA3.1(IGFBP7)-transfected RKO cells, including albumin (ALB), 60 kDa heat shock protein(HSP60), Actin cytoplasmic 1 or 2, pyruvate kinase muscle 2(PKM2), beta subunit of phenylalanyl-tRNA synthetase(FARSB) and hypothetical protein. The downregulation of HSP60 by IGFBP7 was confirmed by western blot and ELISA. Recombinant human HSP60 protein could increase the proliferation rate and the colony formation ability of PcDNA3.1(IGFBP7)-RKO cells.

Conclusion

HSP60 was an important downstream molecule of IGFBP7. The downregulation of HSP60 induced by IGFBP7 may be, at least in part, responsible for IGFBP7's tumor suppressive biological behaviour in CRC.

ING2 is upregulated in colon cancer and increases invasion by enhanced MMP13 expression

Inhibitor of growth 2 (ING2) is associated with chromatin remodeling and regulation of gene expression by binding to a methylated histone H3K4 residue and recruiting HDAC complexes to the region. The aim of our study is to investigate the regulation of ING2 expression and the clinical significance of upregulated ING2 in colon cancer. Here, we show that the ING2 mRNA level in colon cancer tissue increased to more than twice than that in normal mucosa in the 45% of colorectal cancer cases that we examined. A putative NF-kappaB binding site was found in the ING2 promoter region. We confirmed that NF-kappaB could bind to the ING2 promoter by EMSA and luciferase assays. Subsequent microarray analyses revealed that ING2 upregulates expression of matrix metalloproteinase 13 (MMP13), which enhances cancer invasion and metastasis. ING2 regulation of MMP13 expression was confirmed in both ING2 overexpression and knock down experiments. MMP13 expression was further induced by coexpression of ING2 with HDAC1 or with mSin3A, suggesting that the ING2-HDAC1-mSin3A complex members regulates expression of MMP13. In vitro invasion assay was performed to determine functional significance of ING2 upregulation. ING2 overexpressed cells exhibited greater invasive potential. Taken together, upregulation of ING2 was associated with colon cancer and MMP13-dependent cellular invasion, indicating that ING2 expression might be involved with cancer invasion and metastasis.

Novel autoantigens immunogenic in COPD patients

Background

Chronic obstructive pulmonary disease (COPD) is a respiratory inflammatory condition with autoimmune features including IgG autoantibodies. In this study we analyze the complexity of the autoantibody response and reveal the nature of the antigens that are recognized by autoantibodies in COPD patients.

Methods

An array of 1827 gridded immunogenic peptide clones was established and screened with 17 sera of COPD patients and 60 healthy controls. Protein arrays were evaluated both by visual inspection and a recently developed computer aided image analysis technique. By this computer aided image analysis technique we computed the intensity values for each peptide clone and each serum and calculated the area under the receiver operator characteristics curve (AUC) for each clone and the separation COPD sera versus control sera.

Results

By visual evaluation we detected 381 peptide clones that reacted with autoantibodies of COPD patients including 17 clones that reacted with more than 60% of the COPD sera and seven clones that reacted with more than 90% of the COPD sera. The comparison of COPD sera and controls by the automated image analysis system identified 212 peptide clones with informative AUC values. By in silico sequence analysis we found an enrichment of sequence motives previously associated with immunogenicity.

Conclusion

The identification of a rather complex humoral immune response in COPD patients supports the idea of COPD as a disease with strong autoimmune features. The identification of novel immunogenic antigens is a first step towards a better understanding of the autoimmune component of COPD.

The expression of heat shock protein HSP60A reveals a dynamic mitochondrial pattern in Drosophila melanogaster embryos

The evolutionarily conserved hsp60 ( heat-shock protein 60) family of molecular chaperones ensures the correct folding of nuclear-encoded proteins after their translocation across the mitochondrial membrane during development as well as after heat-shock treatment. Although the overexpression of HSP60 proteins and their localization in the cytoplasm have been linked with many humans pathologies, the detailed pattern of their expression in different animal models and their subcellular localization during normal development and in stress conditions are little-known. In this report, we have used two-dimensional gel electrophoresis followed by MALDI-TOF to identify and purify heat shock protein HSP60A of Drosophila melanoagaster. We demonstrate that it is heat-shock inducible and describe two novel antisera, specifically designed to recognize the denatured and native polypeptide, respectively, in Drosophila. Immunoelectron microscopy and immunostaining of Drosophila cells with these antibodies reveals that HSP60A is always localized to the inner membrane of mitochondria. Expression of HSP60A is post-transcriptionally regulated in a highly dynamic pattern during embryogenesis, even under heat-shock conditions. In contrast, in very stressful situations, its expression is upregulated transcriptionally over the entire embryo. These findings suggest novel roles for HSP60 family proteins during normal Drosophila development.

Proteomics-based identification of HSP60 as a tumor-associated antigen in colorectal cancer

Patients with cancer frequently develop autoantibodies. The identification of tumor autoantigens may have utility in early cancer diagnosis and immunotherapy. In this study, we used serological proteomics analysis (SERPA) to identify tumor proteins that elicit humoral response in colorectal cancer (CRC). The CRC cell line HCT116 was used as a source of proteins for 2-DE and subsequent Western blot analysis in which individual serum from patients with CRC was analyzed for autoantibodies. An autoantibody against HSP60 identified by MS was detected in 13 out of 25 patients with CRC and 1 out of 15 healthy subjects. In addition, the HSP60 expressions in tumor tissues collected from 40 patients with CRC were assessed by immunohistochemistry, and serum specimens from 100 patients with cancer and 30 healthy controls were screened for antibody titer to HSP60 by ELISA. The results showed that expressions of HSP60 in tumor tissue and serum antibody titer to HSP60 were significantly higher in patients with CRC than in healthy subjects. Thus, we conclude that the SERPA is an excellent assay for the identification of tumor-associated antigens and tumor markers. The detection of HSP60 may have clinical utility in CRC screening, diagnosis, and immunotherapy.

Mitochondrial membrane permeabilization in cell death

Irrespective of the morphological features of end-stage cell death (that may be apoptotic, necrotic, autophagic, or mitotic), mitochondrial membrane permeabilization (MMP) is frequently the decisive event that delimits the frontier between survival and death. Thus mitochondrial membranes constitute the battleground on which opposing signals combat to seal the cell's fate. Local players that determine the propensity to MMP include the pro- and antiapoptotic members of the Bcl-2 family, proteins from the mitochondrialpermeability transition pore complex, as well as a plethora of interacting partners including mitochondrial lipids. Intermediate metabolites, redox processes, sphingolipids, ion gradients, transcription factors, as well as kinases and phosphatases link lethal and vital signals emanating from distinct subcellular compartments to mitochondria. Thus mitochondria integrate a variety of proapoptotic signals. Once MMP has been induced, it causes the release of catabolic hydrolases and activators of such enzymes (including those of caspases) from mitochondria. These catabolic enzymes as well as the cessation of the bioenergetic and redox functions of mitochondria finally lead to cell death, meaning that mitochondria coordinate the late stage of cellular demise. Pathological cell death induced by ischemia/reperfusion, intoxication with xenobiotics, neurodegenerative diseases, or viral infection also relies on MMP as a critical event. The inhibition of MMP constitutes an important strategy for the pharmaceutical prevention of unwarranted cell death. Conversely, induction of MMP in tumor cells constitutes the goal of anticancer chemotherapy.