Leak after sleeve gastrectomy with positive intraoperative indocyanine green test: Avoidable scenario?

BACKGROUND: The staple line gastric leak (GL) is estimated to be the most serious complication of the sleeve gastrectomy. The use of indocyanine green (ICG) has been introduced in minimally invasive surgery to show the vascularization of the stomach in real time and its application to the gastroesophageal junction (GE) during Laparoscopic Sleeve Gastrectomy (LSG) seems very promising. CASE PRESENTATION: We present the case of a 40-year-old female underwent laparoscopic sleeve gastrectomy. Intraoperative indocyanine green test showed a small dark area in the proximal third of the staple line reinforced with fibrin glue. Two weeks later the patient presented to the emergency room (ED) with abdominal pain, fever, vomiting, intolerance to oral intake and the evidence of a leak on the abdomen Computer Tomography (CT). The UIN for ClinicalTrial.gov Protocol Registration and Results System is: NCT05337644 for the Organization UFoggia. CONCLUSIONS: This case report shows that intraoperative ICG test can be helpful in determining which patients are at greater risk of the leak and, more importantly, the cause of the leak but further tests are needed to determine if the ICG predicts leak due to ischemia.

TRAP1 regulates the response of colorectal cancer cells to hypoxia and inhibits ribosome biogenesis under conditions of oxygen deprivation.

Metabolic rewiring fuels rapid cancer cell proliferation by promoting adjustments in energetic resources, and increasing glucose uptake and its conversion into lactate, even in the presence of oxygen. Furthermore, solid tumors often contain hypoxic areas and can rapidly adapt to low oxygen conditions by activating hypoxia inducible factor (HIF)­1α and several downstream pathways, thus sustaining cell survival and metabolic reprogramming. Since TNF receptor­associated protein 1 (TRAP1) is a HSP90 molecular chaperone upregulated in several human malignancies and is involved in cancer cell adaptation to unfavorable environments and metabolic reprogramming, in the present study, its role was investigated in the adaptive response to hypoxia in human colorectal cancer (CRC) cells and organoids. In the present study, glucose uptake, lactate production and the expression of key metabolic genes were evaluated in TRAP1­silenced CRC cell models under conditions of hypoxia/normoxia. Whole genome gene expression profiling was performed in TRAP1­silenced HCT116 cells exposed to hypoxia to establish the role of TRAP1 in adaptive responses to oxygen deprivation. The results revealed that TRAP1 was involved in regulating hypoxia­induced HIF­1α stabilization and glycolytic metabolism and that glucose transporter 1 expression, glucose uptake and lactate production were partially impaired in TRAP1­silenced CRC cells under hypoxic conditions. At the transcriptional level, the gene expression reprogramming of cancer cells driven by HIF­1α was partially inhibited in TRAP1­silenced CRC cells and organoids exposed to hypoxia. Moreover, Gene Set Enrichment Analysis of TRAP1­silenced HCT116 cells exposed to hypoxia demonstrated that TRAP1 was involved in the regulation of ribosome biogenesis and this occurred with the inhibition of the mTOR pathway. Therefore, as demonstrated herein, TRAP1 is a key factor in maintaining HIF­1α­induced genetic/metabolic program under hypoxic conditions and may represent a promising target for novel metabolic therapies.

One-step versus two-step procedure for management procedures for management of concurrent gallbladder and common bile duct stones. Outcomes and cost analysis.

BACKGROUND: The management of cholelithiasis and choledocholithiasis combined is controversial. The more frequent approach is a two-stage procedure, with endoscopic sphincterotomy and stone removal from the bile duct followed by laparoscopic cholecystectomy. This study aims to demonstrate how, on the basis of the personal experience, the Rendez-vous technique, that combines the two techniques in a single-stage operation is better than the sequential treatment. METHODS: Between June 2017 to December 2019, 40 consecutive patients with cholelithiasis and choledocholithiasis combined were enrolled for the study: 20 were treated with the sequential treatment and 20 with the Rendez-vous method. The preoperative diagnostic work-up was similar in the two group. The endpoints of the study included incidence of endoscopic and surgical complications, rate of hospitalization and cost analysis. RESULTS: The study showed no difference in demographic parameters between the two groups, but the success rate of clearance of CBD was significantly smaller for sequential arm, with the need of additional procedures. We found a statistical reduction of postoperative acute pancreatitis, hospital stay and charges in Rendez-vous group, at the expense of a prolonged total operating time. CONCLUSIONS: The data of the study confirm the superiority of the Rendez-vous technique because it resolves cholelithiasis associated with choledocholithiasis in a single surgical act, with greater acceptance of the patient who avoids a second invasive surgical act, and with a reduction in complications; moreover, it requires shorter hospitalization, resulting in reduced costs. We propose this option in the management of cases where preoperative ERCP-ES has failed. KEY WORDS: Common bile duct stones, Cholecysto-choledocholithiasis, Endoscopic retrograde cholangiopancreatography, Endoscopic sphincterotomy, Laparoscopic cholecystectomy, Laparo-endoscopic Rendez-vous.

Novel Epigenetic Eight-Gene Signature Predictive of Poor Prognosis and MSI-Like Phenotype in Human Metastatic Colorectal Carcinomas.

Epigenetics is involved in tumor progression and drug resistance in human colorectal carcinoma (CRC). This study addressed the hypothesis that the DNA methylation profiling may predict the clinical behavior of metastatic CRCs (mCRCs). The global methylation profile of two human mCRC subgroups with significantly different outcome was analyzed and compared with gene expression and methylation data from The Cancer Genome Atlas COlon ADenocarcinoma (TCGA COAD) and the NCBI GENE expression Omnibus repository (GEO) GSE48684 mCRCs datasets to identify a prognostic signature of functionally methylated genes. A novel epigenetic signature of eight hypermethylated genes was characterized that was able to identify mCRCs with poor prognosis, which had a CpG-island methylator phenotype (CIMP)-high and microsatellite instability (MSI)-like phenotype. Interestingly, methylation events were enriched in genes located on the q-arm of chromosomes 13 and 20, two chromosomal regions with gain/loss alterations associated with adenoma-to-carcinoma progression. Finally, the expression of the eight-genes signature and MSI-enriching genes was confirmed in oxaliplatin- and irinotecan-resistant CRC cell lines. These data reveal that the hypermethylation of specific genes may provide prognostic information that is able to identify a subgroup of mCRCs with poor prognosis.

TRAP1 enhances Warburg metabolism through modulation of PFK1 expression/activity and favors resistance to EGFR inhibitors in human colorectal carcinomas.

Metabolic rewiring is a mechanism of adaptation to unfavorable environmental conditions and tumor progression. TRAP1 is an HSP90 molecular chaperone upregulated in human colorectal carcinomas (CRCs) and responsible for downregulation of oxidative phosphorylation (OXPHOS) and adaptation to metabolic stress. The mechanism by which TRAP1 regulates glycolytic metabolism and the relevance of this regulation in resistance to EGFR inhibitors were investigated in patient-derived CRC spheres, human CRC cells, samples, and patients. A linear correlation was observed between TRAP1 levels and 18 F-fluoro-2-deoxy-glucose (18 F-FDG) uptake upon PET scan or GLUT1 expression in human CRCs. Consistently, TRAP1 enhances GLUT1 expression, glucose uptake, and lactate production and downregulates OXPHOS in CRC patient-derived spheroids and cell lines. Mechanistically, TRAP1 maximizes lactate production to balance low OXPHOS through the regulation of the glycolytic enzyme phosphofructokinase-1 (PFK1); this depends on the interaction between TRAP1 and PFK1, which favors PFK1 glycolytic activity and prevents its ubiquitination/degradation. By contrast, TRAP1/PFK1 interaction is lost in conditions of enhanced OXPHOS, which results in loss of TRAP1 regulation of PFK1 activity and lactate production. Notably, TRAP1 regulation of glycolysis is involved in resistance of RAS-wild-type CRCs to EGFR monoclonals. Indeed, either TRAP1 upregulation or high glycolytic metabolism impairs cetuximab activity in vitro, whereas TRAP1 targeting and/or inhibition of glycolytic pathway enhances cell response to cetuximab. Finally, a linear correlation between 18 F-FDG PET uptake and poor response to cetuximab in first-line therapy in human metastatic CRCs was observed. These results suggest that TRAP1 is a key determinant of CRC metabolic rewiring and favors resistance to EGFR inhibitors through regulation of glycolytic metabolism.

TRAP1 Regulates Wnt/ß-Catenin Pathway through LRP5/6 Receptors Expression Modulation.

Wnt/ß-Catenin signaling is involved in embryonic development, regeneration, and cellular differentiation and is responsible for cancer stemness maintenance. The HSP90 molecular chaperone TRAP1 is upregulated in 60-70% of human colorectal carcinomas (CRCs) and favors stem cells maintenance, modulating the Wnt/ß-Catenin pathway and preventing ß-Catenin phosphorylation/degradation. The role of TRAP1 in the regulation of Wnt/ß-Catenin signaling was further investigated in human CRC cell lines, patient-derived spheroids, and CRC specimens. TRAP1 relevance in the activation of Wnt/ß-Catenin signaling was highlighted by a TCF/LEF Cignal Reporter Assay in Wnt-off HEK293T and CRC HCT116 cell lines. Of note, this regulation occurs through the modulation of Wnt ligand receptors LRP5 and LRP6 that are both downregulated in TRAP1-silenced cell lines. However, while LRP5 mRNA is significantly downregulated upon TRAP1 silencing, LRP6 mRNA is unchanged, suggesting independent mechanisms of regulation by TRAP1. Indeed, LRP5 is regulated upon promoter methylation in CRC cell lines and human CRCs, whereas LRP6 is controlled at post-translational level by protein ubiquitination/degradation. Consistently, human CRCs with high TRAP1 expression are characterized by the co-upregulation of active ß-Catenin, LRP5 and LRP6. Altogether, these data suggest that Wnt/ß-Catenin signaling is modulated at multiple levels by TRAP1.

IDH1 Targeting as a New Potential Option for Intrahepatic Cholangiocarcinoma Treatment-Current State and Future Perspectives.

Cholangiocarcinoma is a primary malignancy of the biliary tract characterized by late and unspecific symptoms, unfavorable prognosis, and few treatment options. The advent of next-generation sequencing has revealed potential targetable or actionable molecular alterations in biliary tumors. Among several identified genetic alterations, the IDH1 mutation is arousing interest due to its role in epigenetic and metabolic remodeling. Indeed, some IDH1 point mutations induce widespread epigenetic alterations by means of a gain-of-function of the enzyme, which becomes able to produce the oncometabolite 2-hydroxyglutarate, with inhibitory activity on α-ketoglutarate-dependent enzymes, such as DNA and histone demethylases. Thus, its accumulation produces changes in the expression of several key genes involved in cell differentiation and survival. At present, small-molecule inhibitors of IDH1 mutated enzyme are under investigation in preclinical and clinical phases as promising innovative treatments for IDH1-mutated intrahepatic cholangiocarcinomas. This review examines the molecular rationale and the results of preclinical and early-phase studies on novel pharmacological agents targeting mutant IDH1 in cholangiocarcinoma patients. Contextually, it will offer a starting point for discussion on combined therapies with metabolic and epigenetic drugs, to provide molecular support to target the interplay between metabolism and epigenetics, two hallmarks of cancer onset and progression.

Right hemicolectomy: laparoscopic versus robotic approach.

BACKGROUND: Minimally invasive surgery for colorectal cancer has been demonstrated to have the same oncological results as open surgery, with better clinical outcomes. Robotic surgery is an evolution of minimally invasive technique. This study aims to evaluate surgical and oncological short-term outcomes of robotic right colon resection in comparison with the laparoscopic approach. METHODS: Between January 2014 and May 2017, fifteen laparoscopic right hemicolectomies were compared to seven robotic ones. The primary data points included operation time, length of hospital stay, extraction site incision length, complications, and conversions. When malignancy was the indication for surgery, additional data points have been added. RESULTS: The study showed no difference in parameters between the two groups, but estimated blood loss was significantly smaller for Robotic arm. We found a prolonged total operative room time in the robotic arm, while the surgical time is similar in two groups. The data collected about specimen length and number of lymph nodes suggest that robotic procedure is oncologically similar to laparoscopic one. CONCLUSIONS: Robotic approach allows performance of adequate dissection of the right colon with radical lymphadenectomy as in laparoscopic surgery, confirming the safety and oncological efficacy of this technique, with acceptable results and short-term outcomes. KEY WORDS: Da Vinci surgery, XI, Laparoscopic colorectal surgery, Right hemicolectomy, Robot.

Cholesterol Homeostasis Modulates Platinum Sensitivity in Human Ovarian Cancer.

Despite initial chemotherapy response, ovarian cancer is the deadliest gynecologic cancer, due to frequent relapse and onset of drug resistance. To date, there is no affordable diagnostic/prognostic biomarker for early detection of the disease. However, it has been recently shown that high grade serous ovarian cancers show peculiar oxidative metabolism, which is in turn responsible for inflammatory response and drug resistance. The molecular chaperone TRAP1 plays pivotal roles in such metabolic adaptations, due to the involvement in the regulation of mitochondrial respiration. Here, we show that platinum-resistant ovarian cancer cells also show reduced cholesterol biosynthesis, and mostly rely on the uptake of exogenous cholesterol for their needs. Expression of FDPS and OSC, enzymes involved in cholesterol synthesis, are decreased both in drug-resistant cells and upon TRAP1 silencing, whereas the expression of LDL receptor, the main mediator of extracellular cholesterol uptake, is increased. Strikingly, treatment with statins to inhibit cholesterol synthesis reduces cisplatin-induced apoptosis, whereas silencing of LIPG, an enzyme involved in lipid metabolism, or withdrawal of lipids from the culture medium, increases sensitivity to the drug. These results suggest caveats for the use of statins in ovarian cancer patients and highlights the importance of lipid metabolism in ovarian cancer treatment.

Robotic voluminous paraesophageal hernia repair: a case report and review of the literature.

BACKGROUND: The treatment for sliding esophageal hernia with mild gastroesophageal reflux is usually conservative, but surgical treatment is recommended for refractory sliding esophageal hernia, paraesophageal hernia liable to prolapse, or paraesophageal hernia with ulceration and/or stenosis. Robotic surgery overcomes laparoscopic pitfalls by providing steady-state three-dimensional visualization, augmented dexterity with endo-wrist movements, and superior ergonomics for the surgeon. CASE PRESENTATION: To investigate robotic paraesophageal hernia repair, a literature search was conducted using PubMed with the following key words: mini invasive surgery, robotic surgery, hiatal hernia, and Nissen fundoplication. We present the case of a 44-year-old Italian woman with a 20-year history of gastroesophageal reflux disease refractory to medical treatment, who underwent robotic Nissen fundoplication. In our center, we use the da Vinci® Xi™ Surgical System, which is an advanced tool for minimally invasive surgery. CONCLUSIONS: Various reports published in the literature suggested that the robot-assisted approach was effective and was associated with very low postoperative morbidity and was accompanied by satisfactory symptomatic and anatomical radiological outcomes during a follow-up period. The robotic approach to paraesophageal repair is safe and effective with low complication rates. With increased experience, the operative time, length of stay, and complications decrease without compromising surgical principles.

Heat shock proteins in thyroid malignancies: Potential therapeutic targets for poorly-differentiated and anaplastic tumours?

Thyroid cancer is the most common endocrine malignancy, with well-differentiated subtypes characterized by an excellent prognosis due to their optimal sensitivity to standard therapies whereas poorly differentiated and anaplastic tumours by chemo/radio-resistance and unfavourable outcome. Heat Shock Proteins (HSPs) are molecular chaperones overexpressed in thyroid malignancies and involved in crucial functions responsible for thyroid carcinogenesis, as protection from apoptosis, drug resistance and cell migration. Thus, HSPs inhibitors have been proposed as novel therapeutic agents in thyroid cancer to revert molecular mechanisms of tumour progression. In this review, we report an overview on the biological role of HSPs, and specifically HSP90s, in thyroid cancer and their potential involvement as biomarkers. We discuss the rationale to evaluate HSPs inhibitors as innovative anticancer agents in specific subtypes of thyroid cancer characterized by poor response to therapies with the objective to target single family chaperones to reduce, simultaneously, the expression/stability of multiple client proteins.

Gene Copy Number and Post-Transductional Mechanisms Regulate TRAP1 Expression in Human Colorectal Carcinomas.

Tumor Necrosis Factor Receptor-Associated Protein 1 (TRAP1) is a heat shock protein 90 (HSP90) molecular chaperone overexpressed in 60-70% human colorectal carcinomas (CRCs) and the co-upregulation of TRAP1 and associated 6-related proteins identifies metastatic CRCs with poor prognosis. Since the molecular mechanisms responsible for TRAP1 regulation are still unknown, the significance of TRAP1 gene copy number (CN) and the role of post-transductional protein modifications were addressed. TRAP1 gene aneuploidy accounted for 34.5% of cases in a cohort of 58 human CRCs and TRAP1 CN correlated with its mRNA and protein expression, suggesting that transcriptional mechanisms are responsible for TRAP1 upregulation. Furthermore, the analysis of the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium/The Cancer Genome Atlas (CPTAC/TCGA) CRC database showed that TRAP1 polysomy significantly correlates with lymph node involvement. However, a subgroup of tumors showed TRAP1 protein levels independent from its CN. Of note, a direct correlation was observed between TRAP1 protein levels and the expression of S-nitrosoglutathione reductase (GSNOR), a denitrosylase involved in the regulation of protein S-nitrosylation. Furthermore, CRC cell lines exposed to hypoxia or dichloroacetate treatment showed the downregulation of TRAP1 upon GSNOR silencing and this resulted in increased TRAP1 mono/polyubiquitination. These data suggest that transcriptional and post-transductional mechanisms account for TRAP1 expression in human CRCs and GSNOR protects TRAP1 from S-nitrosylation and consequent proteasome degradation mostly in conditions of stress.

BRAF Inhibitors in Thyroid Cancer: Clinical Impact, Mechanisms of Resistance and Future Perspectives.

The Kirsten rat sarcoma viral oncogene homolog (RAS)/v-raf-1 murine leukemia viral oncogene homolog 1 (RAF)/mitogen-activated protein kinase 1 (MAPK) signaling cascade is the most important oncogenic pathway in human cancers. Tumors leading mutations in the gene encoding for v-raf murine sarcoma viral oncogene homolog B (BRAF) serine-threonine kinase are reliant on the MAPK signaling pathway for their growth and survival. Indeed, the constitutive activation of MAPK pathway results in continuous stimulation of cell proliferation, enhancement of the apoptotic threshold and induction of a migratory and metastatic phenotype. In a clinical perspective, this scenario opens to the possibility of targeting BRAF pathway for therapy. Thyroid carcinomas (TCs) bearing BRAF mutations represent approximately 29-83% of human thyroid malignancies and, differently from melanomas, are less sensitive to BRAF inhibitors and develop primary or acquired resistance due to mutational events or activation of alternative signaling pathways able to reactivate ERK signaling. In this review, we provide an overview on the current knowledge concerning the mechanisms leading to resistance to BRAF inhibitors in human thyroid carcinomas and discuss the potential therapeutic strategies, including combinations of BRAF inhibitors with other targeted agents, which might be employed to overcome drug resistance and potentiate the activity of single agent BRAF inhibitors.

Metabolic Dysregulations and Epigenetics: A Bidirectional Interplay that Drives Tumor Progression.

Cancer has been considered, for a long time, a genetic disease where mutations in keyregulatory genes drive tumor initiation, growth, metastasis, and drug resistance. Instead, theadvent of high-throughput technologies has revolutionized cancer research, allowing to investigatemolecular alterations at multiple levels, including genome, epigenome, transcriptome, proteome,and metabolome and showing the multifaceted aspects of this disease. The multi-omics approachesrevealed an intricate molecular landscape where different cellular functions are interconnected andcooperatively contribute to shaping the malignant phenotype. Recent evidence has brought to lighthow metabolism and epigenetics are highly intertwined, and their aberrant crosstalk can contributeto tumorigenesis. The oncogene-driven metabolic plasticity of tumor cells supports the energeticand anabolic demands of proliferative tumor programs and secondary can alter the epigeneticlandscape via modulating the production and/or the activity of epigenetic metabolites. Conversely,epigenetic mechanisms can regulate the expression of metabolic genes, thereby altering themetabolome, eliciting adaptive responses to rapidly changing environmental conditions, andsustaining malignant cell survival and progression in hostile niches. Thus, cancer cells takeadvantage of the epigenetics-metabolism crosstalk to acquire aggressive traits, promote cellproliferation, metastasis, and pluripotency, and shape tumor microenvironment. Understandingthis bidirectional relationship is crucial to identify potential novel molecular targets for theimplementation of robust anti-cancer therapeutic strategies.

HSP90 Molecular Chaperones, Metabolic Rewiring, and Epigenetics: Impact on Tumor Progression and Perspective for Anticancer Therapy.

Heat shock protein 90 (HSP90) molecular chaperones are a family of ubiquitous proteins participating in several cellular functions through the regulation of folding and/or assembly of large multiprotein complexes and client proteins. Thus, HSP90s chaperones are, directly or indirectly, master regulators of a variety of cellular processes, such as adaptation to stress, cell proliferation, motility, angiogenesis, and signal transduction. In recent years, it has been proposed that HSP90s play a crucial role in carcinogenesis as regulators of genotype-to-phenotype interplay. Indeed, HSP90 chaperones control metabolic rewiring, a hallmark of cancer cells, and influence the transcription of several of the key-genes responsible for tumorigenesis and cancer progression, through either direct binding to chromatin or through the quality control of transcription factors and epigenetic effectors. In this review, we will revise evidence suggesting how this interplay between epigenetics and metabolism may affect oncogenesis. We will examine the effect of metabolic rewiring on the accumulation of specific metabolites, and the changes in the availability of epigenetic co-factors and how this process can be controlled by HSP90 molecular chaperones. Understanding deeply the relationship between epigenetic and metabolism could disclose novel therapeutic scenarios that may lead to improvements in cancer treatment.

Endoplasmic Reticulum Stress and Unfolded Protein Response in Breast Cancer: The Balance between Apoptosis and Autophagy and Its Role in Drug Resistance.

The unfolded protein response (UPR) is a stress response activated by the accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum (ER) and its uncontrolled activation is mechanistically responsible for several human pathologies, including metabolic, neurodegenerative, and inflammatory diseases, and cancer. Indeed, ER stress and the downstream UPR activation lead to changes in the levels and activities of key regulators of cell survival and autophagy and this is physiologically finalized to restore metabolic homeostasis with the integration of pro-death or/and pro-survival signals. By contrast, the chronic activation of UPR in cancer cells is widely considered a mechanism of tumor progression. In this review, we focus on the relationship between ER stress, apoptosis, and autophagy in human breast cancer and the interplay between the activation of UPR and resistance to anticancer therapies with the aim to disclose novel therapeutic scenarios. The hypothesis that autophagy and UPR may provide novel molecular targets in human malignancies is discussed.

TRAP1: a viable therapeutic target for future cancer treatments?

INTRODUCTION: HSP90 molecular chaperones (i.e., HSP90α, HSP90ß, GRP94 and TRAP1) are potential therapeutic targets to design novel anticancer agents. However, despite numerous designed HSP90 inhibitors, most of them have failed due to unfavorable toxicity profiles and lack of specificity toward different HSP90 paralogs. Indeed, a major limitation in this field is the high structural homology between different HSP90 chaperones, which significantly limits our capacity to design paralog-specific inhibitors. Area covered: This review examines the relevance of TRAP1 in tumor development and progression, with an emphasis on its oncogenic/oncosuppressive role in specific human malignancies and its multifaceted and context-dependent functions in cancer cells. Herein, we discuss the rationale for considering TRAP1 as a potential molecular target and the strategies used to date, to achieve its compartmentalized inhibition directly in mitochondria. Expert opinion: TRAP1 targeting may represent a promising strategy for cancer therapy, based on the increasing and compelling evidence supporting TRAP1 involvement in human carcinogenesis. However, considering the complexity of TRAP1 biology, future strategies of drug discovery need to improve selectivity and specificity toward TRAP1 respect to other HSP90 paralogs. The characterization of specific human malignancies suitable for TRAP1 targeting is also mandatory.

TRAP1 controls cell cycle G2-M transition through the regulation of CDK1 and MAD2 expression/ubiquitination.

Regulation of tumour cell proliferation by molecular chaperones is still a complex issue. Here, the role of the HSP90 molecular chaperone TRAP1 in cell cycle regulation was investigated in a wide range of human breast, colorectal, and lung carcinoma cell lines, and tumour specimens. TRAP1 modulates the expression and/or the ubiquitination of key cell cycle regulators through a dual mechanism: (i) transcriptional regulation of CDK1, CYCLIN B1, and MAD2, as suggested by gene expression profiling of TRAP1-silenced breast carcinoma cells; and (ii) post-transcriptional quality control of CDK1 and MAD2, being the ubiquitination of these two proteins enhanced upon TRAP1 down-regulation. Mechanistically, TRAP1 quality control on CDK1 is crucial for its regulation of mitotic entry, since TRAP1 interacts with CDK1 and prevents CDK1 ubiquitination in cooperation with the proteasome regulatory particle TBP7, this representing the limiting factor in TRAP1 regulation of the G2-M transition. Indeed, TRAP1 silencing results in enhanced CDK1 ubiquitination, lack of nuclear translocation of CDK1/cyclin B1 complex, and increased MAD2 degradation, whereas CDK1 forced up-regulation partially rescues low cyclin B1 and MAD2 levels and G2-M transit in a TRAP1-poor background. Consistently, the CDK1 inhibitor RO-3306 is less active in a TRAP1-high background. Finally, a significant correlation was observed between TRAP1 and Ki67, CDK1 and/or MAD2 expression in breast, colorectal, and lung human tumour specimens. This study represents the first evidence that TRAP1 is relevant in the control of the complex machinery that governs cell cycle progression and mitotic entry and provides a strong rationale to regard TRAP1 as a biomarker to select tumours with deregulated cell cycle progression and thus likely poorly responsive to novel cell cycle inhibitors. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Stress-Adaptive Response in Ovarian Cancer Drug Resistance: Role of TRAP1 in Oxidative Metabolism-Driven Inflammation.

Metabolic reprogramming is one of the most frequent stress-adaptive response of cancer cells to survive environmental changes and meet increasing nutrient requirements during their growth. These modifications involve cellular bioenergetics and cross talk with surrounding microenvironment, in a dynamic network that connect different molecular processes, such as energy production, inflammatory response, and drug resistance. Even though the Warburg effect has long been considered the main metabolic feature of cancer cells, recent reports identify mitochondrial oxidative metabolism as a driving force for tumor growth in an increasing number of cellular contexts. In recent years, oxidative phosphorylation has been linked to a remodeling of inflammatory response due to autocrine or paracrine secretion of interleukines that, in turn, induces a regulation of gene expression involving, among others, molecules responsible for the onset of drug resistance. This process is especially relevant in ovarian cancer, characterized by low survival, high frequency of disease relapse and chemoresistance. Recently, the molecular chaperone TRAP1 (tumor necrosis factor-associated protein 1) has been identified as a key junction molecule in these processes in ovarian cancer: in fact, TRAP1 mediates a metabolic switch toward oxidative phosphorylation that, in turn, triggers cytokines secretion, with consequent gene expression remodeling, finally leading to cisplatin resistance and epithelial-to-mesenchymal transition in ovarian cancer models. This review summarizes how metabolism, chemoresistance, inflammation, and epithelial-to-mesenchymal transition are strictly interconnected, and how TRAP1 stays at the crossroads of these processes, thus shedding new lights on molecular networks at the basis of ovarian cancer.

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 ßCatenin) 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.