Up-regulation of mitochondrial chaperone TRAP1 in ulcerative colitis associated colorectal cancer

Unraveling Crucial Mitochondria-Related Genes in the Transition from Ulcerative Colitis to Colorectal Cancer

Purpose

To clarify the significance of mitochondria-related differentially expressed genes (MTDEGs) in UC carcinogenesis through a bioinformatics analysis and provide potential therapeutic targets for patients with UC associated colorectal cancer.

Methods

Microarray GSE37283 was utilized to investigate differentially expressed genes (DEGs) in UC and UC with neoplasia (UCN). MTDEGs were identified by intersecting DEGs with human mitochondrial genes. Utilizing LASSO and random forest analyses, we identified three crucial genes. Subsequently, using ROC curve to investigate the predictive ability of three key genes. Following, three key genes were confirmed in AOM/DSS mice model by Real-time PCR. Finally, single-sample gene set enrichment analysis (ssGSEA) was employed to explore the correlation between the hub genes and immune cells infiltration in UC carcinogenesis.

Results

The three identified hub MTDEGs (HMGCS2, MAVS, RDH13) may exhibit significant diagnostic specificity in the transition from UC to UCN. Real-time PCR assay further confirmed that the expressions of HMGCS2 and RDH13 were significantly downregulated in UCN mice than that in UC mice. ssGSEA analysis revealed the hub genes were highly associated with CD56dim natural killer cells.

Conclusion

RDH13, HMGCS2, and MAVS may become diagnostic indicators and potential biomarkers for UCN. Our research has the potential to enhance our understanding of the mechanisms underlying carcinogenesis in UC.

A complementary metaproteomic approach to interrogate microbiome cultivated from clinical colon biopsies

The human gut microbiome plays a vital role in preserving individual health and is intricately involved in essential functions. Imbalances or dysbiosis within the microbiome can significantly impact human health and are associated with many diseases. Several metaproteomics platforms are currently available to study microbial proteins within complex microbial communities. In this study, we attempted to develop an integrated pipeline to provide deeper insights into both the taxonomic and functional aspects of the cultivated human gut microbiomes derived from clinical colon biopsies. We combined a rapid peptide search by MSFragger against the Unified Human Gastrointestinal Protein database and the taxonomic and functional analyses with Unipept Desktop and MetaLab-MAG. Across seven samples, we identified and matched nearly 36,000 unique peptides to approximately 300 species and 11 phyla. Unipept Desktop provided gene ontology, InterPro entries, and enzyme commission number annotations, facilitating the identification of relevant metabolic pathways. MetaLab-MAG contributed functional annotations through Clusters of Orthologous Genes and Non-supervised Orthologous Groups categories. These results unveiled functional similarities and differences among the samples. This integrated pipeline holds the potential to provide deeper insights into the taxonomy and functions of the human gut microbiome for interrogating the intricate connections between microbiome balance and diseases.

The development of cancers research based on mitochondrial heat shock protein 90

Mitochondrial heat shock protein 90 (mtHsp90), including Tumor necrosis factor receptor-associated protein 1 (TRAP1) and Hsp90 translocated from cytoplasm, modulating cellular metabolism and signaling pathways by altering the conformation, activity, and stability of numerous client proteins, and is highly expressed in tumors. mtHsp90 inhibition results in the destabilization and eventual degradation of its client proteins, leading to interference with various tumor-related pathways and efficient control of cancer cell development. Among these compounds, gamitrinib, a specific mtHsp90 inhibitor, has demonstrated its safety and efficacy in several preclinical investigations and is currently undergoing evaluation in clinical trials. This review aims to provide a comprehensive overview of the present knowledge pertaining to mtHsp90, encompassing its structure and function. Moreover, our main emphasis is on the development of mtHsp90 inhibitors for various cancer therapies, to present a thorough overview of the recent pre-clinical and clinical advancements in this field.

Inhibition of TRAP1 Accelerates the DNA Damage Response, Activation of the Heat Shock Response and Metabolic Reprogramming in Colon Cancer Cells

BACKGROUND

Colorectal cancer (CRC) is one of the major causes of cancer-related mortality worldwide. The tumor microenvironment plays a significant role in CRC development, progression and metastasis. Oxidative stress in the colon is a major etiological factor impacting tumor progression. Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial member of the heat shock protein 90 (HSP90) family that is involved in modulating apoptosis in colon cancer cells under oxidative stress. We undertook this study to provide mechanistic insight into the role of TRAP1 under oxidative stress in colon cells.

METHODS

We first assessed the The Cancer Genome Atlas (TCGA) CRC gene expression dataset to evaluate the expression of TRAP1 and its association with oxidative stress and disease progression. We then treated colon HCT116 cells with hydrogen peroxide to induce oxidative stress and with the TRAP1 inhibitor gamitrinib-triphenylphosphonium (GTPP) to inhibit TRAP1. We examined the cellular proteomic landscape using liquid chromatography tandem mass spectrometry (LC-MS/MS) in this context compared to controls. We further examined the impact of treatment on DNA damage and cell survival.

RESULTS

TRAP1 expression under oxidative stress is associated with the disease outcomes of colorectal cancer. TRAP1 inhibition under oxidative stress induced metabolic reprogramming and heat shock factor 1 (HSF1)-dependent transactivation. In addition, we also observed enhanced induction of DNA damage and cell death in the cells under oxidative stress and TRAP1 inhibition in comparison to single treatments and the nontreatment control.

CONCLUSIONS

These findings provide new insights into TRAP1-driven metabolic reprogramming in response to oxidative stress.

The Epithelial to Mesenchymal Transition in Colorectal Cancer Progression: The Emerging Role of Succinate Dehydrogenase Alterations and Succinate Accumulation

Colorectal cancer (CRC) stands as the third most significant contributor to cancer-related mortality worldwide. A major underlying reason is that the detection of CRC usually occurs at an advanced metastatic stage, rendering therapies ineffective. In the progression from the in situ neoplasia stage to the advanced metastatic stage, a critical molecular mechanism involved is the epithelial-to-mesenchymal transition (EMT). This intricate transformation consists of a series of molecular changes, ultimately leading the epithelial cell to relinquish its features and acquire mesenchymal and stem-like cell characteristics. The EMT regulation involves several factors, such as transcription factors, cytokines, micro RNAs and long noncoding RNAs. Nevertheless, recent studies have illuminated an emerging link between metabolic alterations and EMT in various types of cancers, including colorectal cancers. In this review, we delved into the pivotal role played by EMT during CRC progression, with a focus on highlighting the relationship between the alterations of the tricarboxylic acid cycle, specifically those involving the succinate dehydrogenase enzyme, and the activation of the EMT program. In fact, emerging evidence supports the idea that elucidating the metabolic modifications that can either induce or inhibit tumor progression could be of immense significance for shaping new therapeutic approaches and preventative measures. We conclude that an extensive effort must be directed towards research for the standardization of drugs that specifically target proteins such as SDH and SUCNR1, but also TRAP1, PDH, ERK1/2, STAT3 and the HIF1-α catabolism.

Metabolic targeting of NRF2 potentiates the efficacy of the TRAP1 inhibitor G-TPP through reduction of ROS detoxification in colorectal cancer

Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial homolog of HSP90 chaperones. It plays an important role in protection against oxidative stress and apoptosis by regulating reactive oxidative species (ROS). To further elucidate the mechanistic role of TRAP1 in regulating tumor cell survival, we used gamitrinib-triphenylphosphonium (G-TPP) to inhibit TRAP1 signaling pathways in colon cancer. Inhibition of TRAP1 by G-TPP disrupted redox homeostasis and induced cell death. However, colon cancers show a wide range of responses to G-TPP treatment through the induction of variable ER stress responses and ROS accumulation. Interestingly, a strong inverse correlation was observed between the expression of TRAP1 and antioxidant genes in colon tumor tissues using the GSE106582 database. Using a luciferase reporter assay, we detected increased transcriptional activation of antioxidant response elements (AREs) in G-TPP-treated DLD1 and RKO cells but not in SW48 cells. We found that G-TPP induced upregulation of GRP78, CHOP and PARP cleavage in G-TPP-sensitive cells (SW48). In contrast, G-TPP treatment of G-TPP-resistant cells (DLD1 and RKO) resulted in excessive activation of the antioxidant gene NRF2, leading to ROS detoxification and improved cell survival. The NRF2 target genes HO1 and NQO1 were upregulated in G-TPP-treated DLD1 cells, making the cells more resistant to G-TPP treatment. Furthermore, treatment with both a NRF2 inhibitor and a TRAP1 inhibitor led to excessive ROS production and exacerbated G-TPP-induced cell death in G-TPP-resistant cells. Taken together, dual targeting of TRAP1 and NRF2 may potentially overcome colon cancer resistance by raising cellular ROS levels above the cytotoxic threshold.

The Mitochondrial HSP90 Paralog TRAP1: Structural Dynamics, Interactome, Role in Metabolic Regulation, and Inhibitors

The HSP90 paralog TRAP1 was discovered more than 20 years ago; yet, a detailed understanding of the function of this mitochondrial molecular chaperone remains elusive. The dispensable nature of TRAP1 in vitro and in vivo further complicates an understanding of its role in mitochondrial biology. TRAP1 is more homologous to the bacterial HSP90, HtpG, than to eukaryotic HSP90. Lacking co-chaperones, the unique structural features of TRAP1 likely regulate its temperature-sensitive ATPase activity and shed light on the alternative mechanisms driving the chaperone’s nucleotide-dependent cycle in a defined environment whose physiological temperature approaches 50 °C. TRAP1 appears to be an important bioregulator of mitochondrial respiration, mediating the balance between oxidative phosphorylation and glycolysis, while at the same time promoting mitochondrial homeostasis and displaying cytoprotective activity. Inactivation/loss of TRAP1 has been observed in several neurodegenerative diseases while TRAP1 expression is reported to be elevated in multiple cancers and, as with HSP90, evidence of addiction to TRAP1 has been observed. In this review, we summarize what is currently known about this unique HSP90 paralog and why a better understanding of TRAP1 structure, function, and regulation is likely to enhance our understanding of the mechanistic basis of mitochondrial homeostasis.

Mechanism of HSP90 Inhibitor in the Treatment of DSS-induced Colitis in Mice by Inhibiting MAPK Pathway and Synergistic Effect of Compound Sophorae Decoction

BACKGROUND

The mechanism of Heat Shock Protein 90 (HSP90) in Ulcerative Colitis (UC) has been studied, and mitogenic-activated protein kinases (MAPK) also contribute to the pathogenesis of UC. However, the effect of the HSP90/MAPK pathway in UC is still unclear. Therefore, the mainstay of this research is to explore the mechanism of action of this pathway in UC. Compound sophorae decoction (CSD), as a Chinese herbal decoction, can synergistically affect the above process.

OBJECTIVE

This study aimed to uncover the synergistic effects of HSP90 inhibitors regulating the MAPK pathway for treating DSS-induced colitis in mice and the synergistic effects of CSD.

METHODS

This experiment used oral administration of standard diets containing 3% dextran sodium sulfate (DSS) to establish an experimental colitis model in mice. The model was treated with HSP90 inhibitor, CSD, or dexamethasone. Mouse feces, mobility, body weight, colon length, and colon histopathology scores were recorded daily to assess the degree of colitis inflammation. Expression levels of HSP90 and MAPK pathway-related genes and proteins were evaluated by Western blot and qPCR. The evaluation of intestinal mucosal permeability was measured by enzyme-linked immunosorbent assay (ELISA), which could detect the protein level of D-Amino Acid Oxidase (DAO) and D-lactic acid (D-LA). The same went for downstream molecules AFT-2, p53, and apoptosis-related proteins BAX, BCL-2, Caspase3, and survivin in the MAPK pathway. Immunohistochemical measured p-38, p-JNK, and p-ERK expressions. JAM-A and claudin-1 connexin were tested by immunofluorescence staining. The TUNEL method was for measuring the apoptosis rate of colonic epithelial cells. CBA kit determined the level of inflammatory factors of colons.

RESULTS

HSP90 inhibitor can improve the degree of pathological damage in the colon of mice treated with DSS, increase the mice's weight and the length of the colon, and significantly reduce the disease activity index (DAI) score. Intraperitoneal injection of HSP90 inhibitor can reduce the expression of MAPK pathway markers P38, JNK, ERK, and their phosphorylation and decrease the content of AFT-2 and p53, which is downstream of the MAPK pathway. In addition, treatment of the HSP90 inhibitor up-regulated the expression of anti-apoptotic proteins BCL-2 and survivin, as well as down-regulated apoptotic protein caspase3, BAX in the colon of mice with colitis. Lower levels of inflammatory factors such as IL-6, MCP-1, IFN-γ, TNF, IL-12p70, and increased IL-10 were observed after HSP90 inhibitor therapy. Furthermore, the combination treatment of CSD can enhance the effect of the single HSP90 inhibitor treatment and play a synergistic effect.

CONCLUSION

These data suggest that an HSP90 inhibitor is available to treat UC by inhibiting the MAPK signaling pathway. This axis can restore the intestinal mucosa barrier's function by reducing intestinal mucosa's permeability and inhibiting apoptosis of intestinal epithelial cells. The specific mechanism is that HSP90 inhibitor can reduce the pathological damage and inflammation levels of colitis mice, and reduce the apoptosis rate of colonic epithelial cells and the mucosal permeability, thereby restoring the mucosal barrier function. During this process, CSD works synergistically to improve the therapeutic effect of the HSP90 inhibitor.

The molecular chaperone TRAP1 in cancer: From the basics of biology to pharmacological targeting

TRAP1, the mitochondrial component of the Hsp90 family of molecular chaperones, displays important bioenergetic and proteostatic functions. In tumor cells, TRAP1 contributes to shape metabolism, dynamically tuning it with the changing environmental conditions, and to shield from noxious insults. Hence, TRAP1 activity has profound effects on the capability of neoplastic cells to evolve towards more malignant phenotypes. Here, we discuss our knowledge on the biochemical functions of TRAP1 in the context of a growing tumor mass, and we analyze the possibility of targeting its chaperone functions for developing novel anti-neoplastic approaches.

Solute carrier family 12 member 2 as a proteomic and histological biomarker of dysplasia and neoplasia in ulcerative colitis

BACKGROUND AND AIMS

Ulcerative colitis (UC) patients have a greater risk of developing colorectal cancer through inflammation-dysplasia-carcinoma sequence of transformation. The histopathological diagnosis of dysplasia is therefore of critical clinical relevance, but dysplasia may be difficult to distinguish from inflammatory changes.

METHODS

A proteomic pilot study on 5 UC colorectal dysplastic patients highlighted proteins differentially distributed between paired dysplastic, inflammatory and normal tissues. The best candidate marker was selected and immunohistochemistry confirmation was performed on AOM/DSS mouse model lesions, 37 UC dysplasia, 14 UC cancers, 23 longstanding UC, 35 sporadic conventional adenomas, 57 sporadic serrated lesions and 82 sporadic colorectal cancers.

RESULTS

Differential proteomics found 11 proteins significantly more abundant in dysplasia compared to inflammation, including Solute carrier family 12 member 2 (SLC12A2) which was confidently identified with 8 specific peptides and was below the limit of quantitation in both inflammatory and normal colon. SLC12A2 immunohistochemical analysis confirmed the discrimination of preneoplastic and neoplastic lesions from inflammatory lesions in mice, UC and in sporadic contexts. A specific SLC12A2 staining pattern termed "loss of gradient" reached 89% sensitivity, 95% specificity and 92% accuracy for UC-dysplasia diagnosis together with an inter-observer agreement of 95.24% (multirater κfree of 0.90; IC95%: 0.78 - 1.00). Such discrimination could not be obtained by Ki67 staining. This specific pattern was also associated with sporadic colorectal adenomas and cancers.

CONCLUSIONS

We found a specific SLC12A2 immunohistochemical staining pattern in precancerous and cancerous colonic UC-lesions which could be helpful for diagnosing dysplasia and cancer in UC and non-UC patients.

Oxidative Stress Markers in Inflammatory Bowel Diseases: Systematic Review

Precise diagnostic biomarker in inflammatory bowel diseases (IBD) is still missing. We conducted a comprehensive overview of oxidative stress markers (OSMs) as potential diagnostic, differential, progression, and prognostic markers in IBD. A Pubmed, Web of Knowledge, and Scopus search of original articles on OSMs in IBD, published between January 2000 and April 2020, was conducted. Out of 874 articles, 79 eligible studies were identified and used to prepare the interpretative synthesis. Antioxidants followed by lipid peroxidation markers were the most popular and markers of oxidative DNA damage the least popular. There was a disparity in the number of retrieved papers evaluating biomarkers in the adult and pediatric population (n = 6). Of the reviewed OSMs, a promising performance has been reported for serum total antioxidant status as a mucosal healing marker, mucosal 8-OHdG as a progression marker, and for multi-analyte panels of lipid peroxidation products assessed non-invasively in breath as diagnostic and differential markers in the pediatric population. Bilirubin, in turn, was the only validated marker. There is a desperate need for non-invasive biomarkers in IBD which, however, will not be met in the near future by oxidative stress markers as they are promising but mostly at the early research phase of discovery.

Association of TRAP1 with infliximab-induced mucosal healing in Crohn's disease

BACKGROUND AND AIM

Anti-tumor necrosis factor (TNF) agents, such as infliximab (IFX), have been increasingly used to induce and maintain disease remission in patients with Crohn's disease (CD). Despite a considerable non-response rate, little is known about the genetic predictors of response to anti-TNF therapy in CD. Our aim in this study was to investigate the genetic factors associated with response to anti-TNF therapy in patients with CD.

METHODS

We performed a two-stage genome-wide association study (GWAS) to identify loci influencing the response to IFX among Korean patients with CD, comprising 42 good responders with mucosal healing and 70 non-responders. The achievement of mucosal healing was assessed by endoscopy and imaging. The functional significance of TRAP1 (TNF receptor associated protein 1) was examined using dextran sodium sulfate-induced colitis model in TRAP1 transgenic mice.

RESULTS

The GWAS identified rs2158962, an intronic single nucleotide polymorphism (SNP) of TRAP1, significantly associated with mucosal healing (odds ratio = 4.94; P_combined  = 1.35 × 10^-7 ). In the dextran sodium sulfate-induced acute colitis, TRAP1 transgenic mice showed a better response to IFX than the wild-type mice.

CONCLUSIONS

The TRAP1 gene is associated with mucosal healing in CD patients following IFX therapy. Identifying the genetic predictors of mucosal healing to anti-TNF therapy can prevent patients from exposure to ineffective therapies.

The Functions and Therapeutic Potential of Heat Shock Proteins in Inflammatory Bowel Disease-An Update

Inflammatory bowel disease (IBD) is a multifactorial human intestinal disease that arises from numerous, yet incompletely defined, factors. Two main forms, Crohn's disease (CD) and ulcerative colitis (UC), lead to a chronic pathological form. Heat shock proteins (HSPs) are stress-responsive molecules involved in various pathophysiological processes. Several lines of evidence link the expression of HSPs to the development and prognosis of IBD. HSP90, HSP70 and HSP60 have been reported to contribute to IBD in different aspects. Moreover, induction and/or targeted inhibition of specific HSPs have been suggested to ameliorate the disease consequences. In the present review, we shed the light on the role of HSPs in IBD and their targeting to prevent further disease progression.

Overexpression of the mitochondrial chaperone tumor necrosis factor receptor-associated protein 1 is associated with the poor prognosis of patients with colorectal cancer

Tumor necrosis factor receptor-associated protein-1 (TRAP-1), a mitochondrial chaperone, contributes significantly to the progression of cancer. However, the understanding of its involvement in the clinicopathological characteristics and prognosis of colorectal cancer (CRC) remains limited. The aim of the present study was to assess the significance of TRAP-1 expression in CRC. The expression of TRAP-1 was evaluated in corresponding cancerous, paracancerous, lymph node and distant metastatic tissues of 256 cases of CRC by immunohistochemistry. The associations between TRAP-1 expression and the clinicopathological parameters and survival rates of patients was assessed. Out of 256 patients with CRC, TRAP-1 expression was detected in 203 (79.3%). TRAP-1 expression was significantly increased in cancerous tissue compared with that in corresponding paracancerous tissues (P<0.001). Overexpression of TRAP-1 was significantly associated with differentiation (P=0.011), depth of invasion (P=0.006), lymph node metastasis (P<0.001) and tumor-node-metastasis stage (P<0.001). In patients with high TRAP-1 expression, the 5-year overall survival (OS) rate was 38.0%, in contrast to 56.5% in patients with low TRAP-1 expression (P=0.003). Similarly, the 5-year progression-free survival (PFS) was 26.6% for patients with high TRAP-1 expression and 53.3% for patients with low TRAP-1 expression (P<0.001). Multivariate analyses indicated the TRAP-1 expression is an independent prognostic factor for poorer OS [P=0.015; hazard ratio (HR), 1.914] and PFS (P<0.001; HR, 2.534). Thus, TRAP-1 may serve as a potential biomarker for predicting the prognosis of patients with CRC. Specifically, overexpression of TRAP-1 may predict progression and poor survival in cases of CRC.

Precancer in ulcerative colitis: the role of the field effect and its clinical implications

Cumulative evidence indicates that a significant proportion of cancer evolution may occur before the development of histological abnormalities. While recent improvements in DNA sequencing technology have begun to reveal the presence of these early preneoplastic clones, the concept of 'premalignant field' was already introduced by Slaughter more than half a century ago. Also referred to as 'field effect', 'field defect' or 'field cancerization', these terms describe the phenomenon by which molecular alterations develop in normal-appearing tissue and expand to form premalignant patches with the potential to progress to dysplasia and cancer. Field effects have been well-characterized in ulcerative colitis, an inflammatory bowel disease that increases the risk of colorectal cancer. The study of the molecular alterations that define these fields is informative of mechanisms of tumor initiation and progression and has provided potential targets for early cancer detection. Herein, we summarize the current knowledge about the molecular alterations that comprise the field effect in ulcerative colitis and the clinical utility of these fields for cancer screening and prevention.

TRAP1 protein signature predicts outcome in human metastatic colorectal carcinoma

TRAP1 is a HSP90 molecular chaperone upregulated in colorectal carcinomas and involved in control of intracellular signaling, cell cycle, apoptosis and drug resistance, stemness and bioenergetics through co-traslational regulation of a network of client proteins. Thus, the clinical significance of TRAP1 protein network was analyzed in human colorectal cancers. TRAP1 and/or its client proteins were quantified, by immunoblot analysis, in 60 surgical specimens of colorectal carcinomas at different stages and, by immunohistochemistry, in 9 colorectal adenomatous polyps, 11 in situ carcinomas and 55 metastatic colorectal tumors. TRAP1 is upregulated at the transition between low- and high-grade adenomas, in in situ carcinomas and in about 60% of human colorectal carcinomas, being downregulated only in a small cohort of tumors. The analysis of TCGA database showed that a subgroup of colorectal tumors is characterized by gain/loss of TRAP1 copy number, this correlating with its mRNA and protein expression. Interestingly, TRAP1 is co-expressed with the majority of its client proteins and hierarchical cluster analysis showed that the upregulation of TRAP1 and associated 6-protein signature (i.e., IF2α, eF1A, TBP7, MAD2, CDK1 and βCatenin) identifies a cohort of metastatic colorectal carcinomas with a significantly shorter overall survival (HR 5.4; 95% C.I. 1.1-26.6; p=0.037). Consistently, the prognostic relevance of TRAP1 was confirmed in a cohort of 55 metastatic colorectal tumors. Finally, TRAP1 positive expression and its prognostic value are more evident in left colon cancers. These data suggest that TRAP1 protein network may provide a prognostic signature in human metastatic colorectal carcinomas.

Succinate: An initiator in tumorigenesis and progression

As an intermediate metabolite of the tricarboxylic acid cycle in mitochondria, succinate is widely investigated for its role in metabolism. In recent years, an increasing number of studies have concentrated on the unanticipated role of succinate outside metabolism, acting as, for instance, an inflammatory signal or a carcinogenic initiator. Actually, succinate dehydrogenase gene mutations and abnormal succinate accumulation have been observed in a battery of hereditary and sporadic malignancies. In this review, we discuss the unexpected role of succinate and possible mechanisms that may contribute to its accumulation. Additionally, we describe how the high concentration of succinate in the tumor microenvironment acts as an active participant in tumorigenesis, rather than a passive bystander or innocent victim. Focusing on mechanism-based research, we summarize some targeted therapies which have been applied to the clinic or are currently under development. Furthermore, we posit that investigational drugs with different molecular targets may expand our horizon in anticancer therapy.

Clinicopathologic significance of TRAP1 expression in colorectal cancer: a large scale study of human colorectal adenocarcinoma tissues

Background

Colorectal cancer is the major cause of cancer mortality, despite development of therapeutic strategies. The novel marker tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial heat shock protein that has been related to drug resistance and protection from apoptosis in colorectal cancer. This study aims to delineate the clinicopathologic significance of TRAP1 expression in colorectal cancer.

Methods

Seven-hundred and fourteen FFPE tissues were collected from colorectal cancer patients who underwent surgery from February 2002 to July 2011 at Dong-A University Medical Center, Busan, South Korea. We performed TRAP1 immunohistochemistry using tissue microarray, and divided into two groups, TRAP1 high expression group and low expression group. Statistical analysis was utilized to evaluate the association of TRAP1 with clinicopathologic characteristics and disease-specific survival of patients.

Results

High TRAP1 expression was observed in 564 cases (79%) and low expression was 150 cases (21%). TRAP1 expression was significantly increased in colorectal cancer with advanced pathologic T-stage compared with that in early T-stage (p = 0.008). By univariate survival analysis, high TRAP1 expression was significantly associated with worse disease-specific survival (p = 0.01). But, TRAP1 expression was marginally associated with lymph node involvement and tumor differentiation (p = 0.085, p = 0.082, respectively). Multivariate analysis indicated that TRAP1 expression (hazard ratio, 1.947; 95% CI, 1.270 to 2.984; p = 0.002), and pathologic T stage (hazard ratio, 3.190; 95% CI, 1.275 to 7.983; p = 0.013) were independent prognostic factors for colorectal adenocarcinomas.

Conclusions

Here, we found that overexpression of TRAP1 might contribute to tumor cell local invasion of colorectal cancer. The association between TRAP1 overexpression and worse disease-specific survival also suggested that TRAP1 protein expression might have oncogenic role. Consequently, our data demonstrated that TRAP1 expression was a good prognostic biomarker for depth of invasion and disease-specific survival in colorectal cancer.

Aberrantly upregulated TRAP1 is required for tumorigenesis of breast cancer

Tumor necrosis factor receptor-associated protein 1 (TRAP1) is abnormally expressed in many cancers. In this study, we showed that TRAP1 is aberrantly upregulated in breast tumors compared to control tissues. TRAP1 knockdown downregulates mitochondrial aerobic respiratory, sensitizes cells to lethal stimuli, and inhibited tumor growth in MDA-MB-231 and MCF-7 breast cancer cells in vivo. TRAP1 overexpression, however, enhances the capacity to cope with stress conditions. These evidences suggested that TRAP1 is required for tumorigenesis. We also found that TRAP1 regulates the mitochondrial morphology. Relatively lower TRAP1 levels are associated with the rod-shaped mitochondrial phenotype in invasive and metastatic MDA-MB-231 breast cancer cells; on the contrary, higher TRAP1 levels are associated with the tubular network-shaped mitochondrial phenotype in non-invasive MCF-7 cells. Interestingly, the expression of TRAP1 in human breast cancer specimens inversely correlates with tumor grade. Overexpression of TRAP1 in MDA-MB-231 cells causes mitochondrial fusion, triggers mitochondria to form tubular networks, and suppresses cell migration and invasion in vitro and in vivo. These data link TRAP1-regulated mitochondrial dynamics and function with tumorigenesis of breast cancer and suggested that TRAP1 may therefore be a potential target for breast cancer drug development.

Biomarkers for colitis-associated colorectal cancer

Patients with extensive ulcerative colitis (UC) of more than eight years duration have an increased risk of colorectal cancer. Molecular biomarkers for dysplasia and cancer could have a great clinical value in managing cancer risk in these UC patients. Using a wide range of molecular techniques - including cutting-edge OMICS technologies - recent studies have identified clinically relevant biomarker candidates from a variety of biosamples, including colonic biopsies, blood, stool, and urine. While the challenge remains to validate these candidate biomarkers in multi-center studies and with larger patient cohorts, it is certain that accurate biomarkers of colitis-associated neoplasia would improve clinical management of neoplastic risk in UC patients. This review highlights the ongoing avenues of research in biomarker development for colitis-associated colorectal cancer.

Cancer surveillance in ulcerative colitis and Crohn's disease: new strategies

PURPOSE OF REVIEW

Inflammatory bowel disease (IBD) patients have a higher incidence of colon cancer than the general population. Colon cancer surveillance has traditionally involved taking numerous random biopsies to provide sufficient yield to detect dysplasia. Recently, consensus guidelines have been published which promote the use of chromoendoscopy for IBD colon cancer surveillance. This presents a new set of opportunities and challenges in the evaluation and management of dysplasia in IBD.

RECENT FINDINGS

Dysplasia, previously thought to be 'invisible' to the endoscopist, is now considered to be 'visible' in the majority of cases with the advent of the use of high-definition endoscopy and chromoendoscopy. This changes how we manage dysplastic lesions, providing the patient options for endoscopic resection rather than promoting total proctocolectomy.

SUMMARY

Implemention of chromoendoscopy may require additional training for endoscopists unfamiliar with the technique. However, if this proves to be cost-effective and provides a higher sensitivity in dysplasia detection, then widespread education and implementation will be well worth the efforts. To do so, future studies will need to prove its benefits in preventing or reducing colon cancer morbidity and mortality in this high-risk patient population.

Expression of tumor necrosis factor receptor-associated protein 1 and its clinical significance in kidney cancer

OBJECTIVE

To investigate the expression and clinical significance of TRAP1 (tumor necrosis factor receptor-associated protein 1) in kidney cancer.

METHODS

TRAP1 expression was detected in kidney cancer and normal kidney tissues by qRT-PCR and immunohistochemistry (IHC), respectively. Then, the correlation of TRAP1 expression with clinicopathological characters and patients' prognosis was evaluated in kidney cancer.

RESULTS

IHC results revealed that the high-expression rates of TRAP1 in kidney cancer tissues and normal kidney tissues were 51.3% (41/80), 23.3% (7/30), and the difference was statistically significant (P=0.01). Also, TRAP1 mRNA level in kidney cancer was found to be significantly greater compared with those in normal kidney by qRT-PCR. In addition, TRAP1 expression in kidney cancer significantly correlated with lymph node metastasis and clinical stage (P<0.05). Kaplan-Meier survival analysis indicated that the mean survival time of patients with TRAP1 low-expression was significantly higher (56 months) than those patients with TRAP1 high-expression (47 months). Meanwhile, Kaplan-Meier and Cox survival analysis indicated that TRAP1, lymph node metastasis and clinical stage were correlated with patients' prognosis.

CONCLUSION

TRAP1 is highly expressed in kidney cancer and correlates with patients prognosis, which may be served as a potential marker for the diagnosis and treatment of kidney cancer.

IL-6/STAT3/SOCS3 signaling pathway playing a regulatory role in ulcerative colitis carcinogenesis

OBJECTIVE

Large-scale clinical studies have shown that ulcerative colities were related with colorectal cancer. In this study, animal model was established by AOM/DSS method to explore the activation of IL-6-STAT3-SOCS3 signaling pathway and the expression of pathway-related proteins in ulcerative colitis carcinogenesis, in order to lay a foundation for exploring the regulation mechanism of IL-6/STAT3/SOCS3 signaling pathway in ulcerative colitis carcinogenesis.

METHOD

AOM/DSS modeling method was used to establish animal models of ulcerative colitis carcinogenesis; colonic mucosa specimens were collected at different time points for pathological examination. Immunohistochemical method and western blot were used to detect the expression of IL6, STAT3 and SOCS3 protein in the control group, UC model + empty vector group and UC model + STAT3 knockout group.

RESULTS

In UC model + empty vector group, IL6 and STAT3 expression was increased as lesion degree increased (P < 0.05). The expression of SOCS3 was weakened and the degree of activation decreased (P < 0.05). IL6 expression increased in UC model + STAT3 knockout group (P < 0.05) while the expression of SOCS3 decreased; compared with the UC model + empty vector group, there was a significant difference (P < 0.05).

CONCLUSION

The expression and activation of IL6 and STAT3 expression were enhanced in ulcerative colitis carcinogenesis, and their expression increased with the lesion degree increased, reflecting the disease progression to a certain extent. The expression and activation of SOCS3 expression decreased. STAT3 had a certain effect on the expression of SOCS3, playing a certain regulatory role in ulcerative colitis carcinogenesis.