Recapitulating the Pharmacological Interactions of Cetuximab with Sunitinib and Cisplatin in Head and Neck Carcinoma Cells in vitro.

INTRODUCTION: Cisplatin is extensively used in the treatment of head and neck carcinomas. Cetuximab combination therapy is employed in recurrent and metastatic settings. Sunitinib showed positive results in the treatment of head and neck carcinomas, both as monotherapy or in combination with cetuximab. Nonetheless, the mechanism governing these pharmacological interactions is largely unresolved. This study investigates the impact of cetuximab on the cytotoxicity of cisplatin and sunitinib using cells representative of head and neck carcinoma and the oral epithelium. METHODS: The uptake and efflux activities of cells were determined using the prototypical fluorescent substrates 4-[4-[dimethylamino]styryl)-1-methyl pyridinium iodide, Hoechst 33342, and calcein-AM in the presence or absence of specific inhibitors in cells pretreated with cetuximab. The expression of key uptake and efflux drug transporters was analyzed using qPCR and immunofluorescence. Cisplatin and sunitinib cytotoxicities after cetuximab pretreatment were evaluated using the PrestoBlue viability assay. RESULTS: Both tumor and nontumor cells showed significant active drug transport activity. Cetuximab substantially deregulated the expression of key transporters involved in drug resistance in head and neck cancer cells. Transporter expression in the nontumor cell was unaffected. Upon cetuximab pretreatment, the half maximal effective toxic concentration of cisplatin was reduced by 0.75-fold and sunitinib by 0.82-fold in cancer cells. Nontumor cells were not sensitive to cisplatin or sunitinib under the conditions tested. CONCLUSION: Cetuximab regulates the expression and activity of key membrane drug transporters in head and neck cancer cells, involved in drug resistance. The deregulation of the transport mechanism behind cisplatin and sunitinib uptake reverses drug resistance and enhances the cytotoxicity of both drugs.

Thioredoxin 1 (Trx1) is associated with poor prognosis in clear cell renal cell carcinoma (ccRCC): an example for the crucial role of redox signaling in ccRCC.

PURPOSE: Thioredoxins are major regulatory proteins of oxidative signaling. Trx1 is the most prominent thioredoxin and, therefore, the current study sought to evaluate the prognostic role of Trx1 in ccRCC. METHODS AND PATIENTS: A tissue micro-array (TMA) study was carried out to evaluate the association of Trx1 with clinicopathological features and survival outcome. Data from the Cancer Genome Atlas (TCGA) were evaluated for the association of characteristics in the Trx1 gene with clinicopathological features and survival outcome. RESULTS: In the TMA, patients with ccRCC that had high Trx1 levels had lower T stages (p < 0.001), less often distant metastases (p = 0.018), lower nuclear grades (p < 0.001), and less often tumor necrosis (p = 0.037) or sarcomatoid features (p = 0.008). Patients with a combined score of ≥ 10 had better DSS than patients with a low combined score of < 10 (HR 95% CI 0.62 (0.39-0.98)). Interestingly, the survival outcome is compartment specific: ccRCC patients whose tumors had exclusively Trx1 expression in the cytoplasm had the worst survival outcome (HR 3.1; 95% CI 1.2-8.0). Genomic data from the TCGA demonstrated that patients with ccRCCs that had Trx1 losses had more advanced clinicopathological features and worse survival outcome in disease specific (p < 0.001), overall (p = 0.001), and progression free survival (p = 0.001) when compared to patients with ccRCCs without copy number variations (CNV) or gains. CONCLUSION: The current study suggests a possible role of Trx1 in the tumor biology of ccRCC and thus, the current study strongly advises in depth investigations of redox signaling pathways in ccRCC.

Variation across operating sites in urinary and sexual outcomes after radical prostatectomy in localized and locally advanced prostate cancer.

PURPOSE: The extent of variation in urinary and sexual functional outcomes after radical prostatectomy (RPE) between prostate cancer (PC) operating sites remains unknown. Therefore, this analysis aims to compare casemix-adjusted functional outcomes (EPIC-26 scores incontinence, irritative/obstructive function and sexual function) between operating sites 12 months after RPE. MATERIALS AND METHODS: Analysis of a cohort of 7065 men treated with RPE at 88 operating sites (prostate cancer centers, "PCCs") between 2016 and 2019. Patients completed EPIC-26 and sociodemographic information surveys at baseline and 12 months after RPE. Survey data were linked to clinical data. EPIC-26 domain scores at 12 months after RPE were adjusted for relevant confounders (including baseline domain score, clinical and sociodemographic information) using regression analysis. Differences between sites were described using minimal important differences (MIDs) and interquartile ranges (IQR). The effects of casemix adjustment on the score results were described using Cohen's d and MIDs. RESULTS: Adjusted domain scores at 12 months varied between sites, with IQRs of 66-78 (incontinence), 89-92 (irritative/obstructive function), and 20-29 (sexual function). Changes in domain scores after casemix adjustment for sites ≥ 1 MID were noted for the incontinence domain (six sites). Cohen's d ranged between - 0.07 (incontinence) and - 0.2 (sexual function), indicating a small to medium effect of casemix adjustment. CONCLUSIONS: Variation between sites was greatest in the incontinence and sexual function domains for RPE patients. Future research will need to identify the factors contributing to this variation. TRIAL REGISTRY: The study is registered at the German Clinical Trial Registry ( https://www.drks.de/drks_web/ ) with the following ID: DRKS00010774.

Identification of the Regulatory Targets of miR-3687 and miR-4417 in Prostate Cancer Cells Using a Proteomics Approach.

MicroRNAs (miRNA) are ubiquitous non-coding RNAs that have a prominent role in cellular regulation. The expression of many miRNAs is often found deregulated in prostate cancer (PCa) and castration-resistant prostate cancer (CRPC). Although their expression can be associated with PCa and CRPC, their functions and regulatory activity in cancer development are poorly understood. In this study, we used different proteomics tools to analyze the activity of hsa-miR-3687-3p (miR-3687) and hsa-miR-4417-3p (miR-4417), two miRNAs upregulated in CRPC. PCa and CRPC cell lines were transfected with miR-3687 or miR-4417 to overexpress the miRNAs. Cell lysates were analyzed using 2D gel electrophoresis and proteins were subsequently identified using mass spectrometry (Maldi-MS/MS). A whole cell lysate, without 2D-gel separation, was analyzed by ESI-MS/MS. The expression of deregulated proteins found across both methods was further investigated using Western blotting. Gene ontology and cellular process network analysis determined that miR-3687 and miR-4417 are involved in diverse regulatory mechanisms that support the CRPC phenotype, including metabolism and inflammation. Moreover, both miRNAs are associated with extracellular vesicles, which point toward a secretory mechanism. The tumor protein D52 isoform 1 (TD52-IF1), which regulates neuroendocrine trans-differentiation, was found to be substantially deregulated in androgen-insensitive cells by both miR-3687 and miR-4417. These findings show that these miRNAs potentially support the CRPC by truncating the TD52-IF1 expression after the onset of androgen resistance.

In Vitro Characterization of Renal Drug Transporter Activity in Kidney Cancer.

The activity of drug transporters is central to the secretory function of the kidneys and a defining feature of renal proximal tubule epithelial cells (RPTECs). The expression, regulation, and function of these membrane-bound proteins is well understood under normal renal physiological conditions. However, the impact of drug transporters on the pathophysiology of kidney cancer is still elusive. In the present study, we employed different renal cell carcinoma (RCC) cell lines and a prototypical non-malignant RPTEC cell line to characterize the activity, expression, and potential regulatory mechanisms of relevant renal drug transporters in RCC in vitro. An analysis of the uptake and efflux activity, the expression of drug transporters, and the evaluation of cisplatin cytotoxicity under the effects of methylation or epidermal growth factor receptor (EGFR) inhibition showed that the RCC cells retained substantial drug transport activity. In RCC cells, P-glycoprotein was localized in the nucleus and its pharmacological inhibition enhanced cisplatin toxicity in non-malignant RPTECs. On the other hand, methylation inhibition enhanced cisplatin toxicity by upregulating the organic cation uptake activity in RCC cells. Differential effects of methylation and EGFR were observed in transporter expression, showing regulatory heterogeneity in these cells. Interestingly, the non-malignant RPTEC cell line that was used lacked the machinery responsible for organic cation transport, which reiterates the functional losses that renal cells undergo in vitro.

Acute myocardial infarction and arterial embolism in a patient with newly diagnosed renal mass: management dilemmas! A case report.

BACKGROUND: Cancer is often associated with a hypercoagulable state and new thrombosis is often the first clinical manifestation of cancer. Surgical treatment of the primary tumor is crucial since it provides the only curative approach in most cases, but management of patients is highly complex, especially in the presence of new antiplatelet drugs and/or anticoagulants. Paraneoplastic syndromes (PNS) represent a frequent complication of renal cell carcinomas (RCC) and include different hematological symptoms in patients, whilst occlusion of arterial blood vessels displays a rare form of PNS accompanying renal tumors. CASE PRESENTATION: We report the case of a 62-year old man who was initially hospitalized due to acute coronary syndrome. He subsequently underwent coronary angioplasty treatment including multiple stenting and treatment with ticagrelor and aspirin. Post-interventional, acute arterial thrombotic emboli of several limb arteries required thrombectomy. By computer tomography we identified a renal lesion suspicious for an RCC and suspected a PNS as underlying cause of the thrombotic complications. Triple anticoagulant therapy was maintained with therapeutic dose low molecular weight heparin (LMWH), aspirin, and clopidogrel, by which we replaced ticagrelor. Surgery was postponed for 4 weeks. We paused LMWH, aspirin and clopidogrel only at the day of surgery and perioperatively restored hemostasis by transfusion of two platelet concentrates. Laparoscopic nephrectomy was uneventful. Pathology confirmed a clear cell RCC. The patient fully recovered whilst slowly reducing anticoagulation dose. CONCLUSIONS: A multidisciplinary team approach of experts in urology, cardiology and hemostasis was key in managing this patient since a personalized thrombosis consult was needed to minimize the risk of reinfarction due to in-stent thrombosis. We report a therapeutic protocol that may be helpful for the management of similar cases. Furthermore, the finding of thrombotic arterial occlusions in larger blood vessels represents a novel complication of PNS in RCC and adds to the varied possible manifestations of this clinical chameleon.

The heat shock protein 70 inhibitor VER155008 suppresses the expression of HSP27, HOP and HSP90ß and the androgen receptor, induces apoptosis, and attenuates prostate cancer cell growth.

Heat shock proteins (HSPs) are molecular chaperones that play a pivotal role in correct folding, stabilization and intracellular transport of many client proteins including those involved in oncogenesis. HSP70, which is frequently overexpressed in prostate cancer (PCa), has been shown to critically contribute to tumor cell survival, and might therefore represent a potential therapeutic target. We treated both the androgen receptor (AR)-positive LNCaP and the AR-negative PC-3 cell lines with the pharmacologic HSP70 inhibitor VER155008. Although we observed antiproliferative effects and induction of apoptosis upon HSP70 inhibition, the apoptotic effect was more pronounced in AR-positive LNCaP cells. In addition, VER155008 treatment induced G1 cell cycle arrest in LNCaP cells and decreased AR expression. Further analysis of the HSP system by Western blot analysis revealed that expression of HSP27, HOP and HSP90ß was significantly inhibited by VER155008 treatment, whereas the HSP40, HSP60, and HSP90α expression remained unchanged. Taken together, VER155008 might serve as a novel therapeutic option in PCa patients independent of the AR expression status.

Dirty deeds done dirt cheap: sensitization of prostate cancer cells to abiraterone treatment using hydroxylated polychlorinated biphenyls.

Effective targeting of androgen biosynthesis by the 17α-hydroxylase/17,20-lyase inhibitor abiraterone prolongs survival in a variety of prostate cancer patients. However, resistance to abiraterone treatment occurs frequently and the development of new drugs supporting or complementing abiraterone therapy is urgently needed. We recently reported antiproliferative and proapoptotic effects of hydroxylated polychlorinated biphenyls (PCBs) on various blood cell lines in vitro. Here we report the biological evaluation of the PCB28 derived OH-metabolites 3-OHCB28 or 3'-OHCB28 in prostate cancer cells. Depending on concentration, both metabolites inhibit the growth of PC3 cells, a cell line representing later stages of advanced prostate cancer. In addition 3'-OHCB28 reduced the necessary concentration of abiraterone required for the inhibition of PC3 cells by a factor of 4. Western blot analysis of cytoprotective heatshock proteins (HSP) implicated a significant reduction of HSP27 expression by 3'-OHCB28 in PC3 cells. Given the known HSP27 suppressive role of abiraterone, our results therefore suggest, that that the pharmacological interaction between abiraterone and 3'-OHCB28 in PC3 cells could be produced by the combined effect of both substances on the expression of HSPs, especially the expression of HSP27. Including the known dose response linkages and pharmacokinetic characteristics of the OH-metabolites described here, we conclude, that the use of hydroxylated PCBs can be supportive for the anti-proliferative treatment of prostate cancer and merits further investigation.

Evaluation of the prognostic role of co-morbidities on disease outcome in renal cell carcinoma patients.

BACKGROUND: Co-morbidities may induce local and systemic tumor progression of renal cell carcinoma (RCC); however, the prognostic impact of co-morbidities has not yet been well characterized. PATIENTS AND METHODS: RCC patients (n = 2206) surgically treated at three academic institutions in the US and Europe were included in the analysis. Presence of diabetes mellitus, hypertension, chronic kidney disease, chronic obstructive pulmonary disease, coronary heart disease, and hypothyroidism were investigated for their association with clinicopathological features and cancer-specific survival. RESULTS: Hypertension was associated with less advanced T stages (p = 0.025), a lower risk of lymph-node (p = 0.026) and distant metastases (p = 0.001), and improved cancer specific survival in univariable analysis (HR 0.81 95% CI 0.69-0.96, p = 0.013). However, hypertension was not an independent prognostic factor after adjustment for TNM stages, grading, and ECOG performance status (HR 0.95, 95% CI 0.80-1.12; p = 0.530). A correlation between the use of concomitant anti-hypertensive medications and improved survival outcome was not identified. All other investigated co-morbidities did not show significant associations with clinicopathological features or cancer-specific survival. CONCLUSION: Although the investigated co-morbidities are capable or inducing pathophysiological changes that are predisposing factors for tumor progression, none is an independent prognostic factor in patients with RCC.

The androgen receptor antagonist enzalutamide induces apoptosis, dysregulates the heat shock protein system, and diminishes the androgen receptor and estrogen receptor ß1 expression in prostate cancer cells.

Enzalutamide's accepted mode of action is by targeting the androgen receptor's (AR) activity. In clinical practice, enzalutamide demonstrates a good benefit-risk profile for the treatment of advanced prostate cancer (PC), even after poor response to standard antihormonal treatment. However, since both, well-established antiandrogens and enzalutamide, target AR functionality, we hypothesized that additional unknown mechanisms might be responsible for enzalutamide's superior anticancer activity. In the current study, PC cells were incubated with enzalutamide and enzalutamide-dependent modulation of apoptotic mechanisms were assessed via Western blot analysis, TDT-mediated dUTP-biotin nick end-labeling assay, and nuclear morphology assay. Alterations of heat shock protein (HSP), AR, and estrogen receptor (ER) expression were examined by Western blot analysis. Enzalutamide attenuated the proliferation of PC cells in a time- and dose-dependent manner. In the presence of enzalutamide, apoptosis occurred which was shown by increased BAX expression, decreased Bcl-2 expression, nuclear pyknosis, and genomic DNA fragmentation. Moreover, enzalutamide inhibited the expression of HSPs primarily involved in steroid receptor stabilization and suppressed AR and ERß1 expression. This study demonstrates for the first time that enzalutamide treatment of PC cells triggers varying molecular mechanisms resulting in antiproliferative effects of the drug. In addition to the well-characterized antagonistic inhibition of AR functionality, we have shown that enzalutamide also affects the intracellular synthesis of steroid receptor-associated HSPs, thereby diminishing the expression of AR and ERß1 proteins and inducing apoptotic pathways. According to an indirect attenuation of HSP-associated factors such as steroid receptors, endometrial carcinoma, uterine leiomyosarcoma, and mamma carcinoma cells also demonstrated inhibited cell growth in the presence of enzalutamide. Our data, therefore, suggest that enzalutamide's high efficacy is at least partially independent of AR and p53 protein expression, which are frequently lost in advanced PC.

Cabazitaxel inhibits prostate cancer cell growth by inhibition of androgen receptor and heat shock protein expression.

PURPOSE: Cabazitaxel, a semi-synthetic taxane of the third generation, inhibits prostate cancer (PC) cell growth by affecting the microtubule architecture. Since cabazitaxel has also been demonstrated to inhibit androgen receptor (AR) functionality, AR and AR-associated heat shock protein (HSP) expressions in the presence of cabazitaxel were characterized. METHODS: AR and HSP expressions were assessed via Western blotting utilizing a PC-cell-line in vitro system incubated with cabazitaxel. RESULTS: Incubation experiments with 0.3 nM cabazitaxel exhibited significantly reduced levels of AR and the AR-associated factors HSP90α, HSP40, and HSP70/HSP90 organising protein. Furthermore, expression of the anti-apoptotic factor HSP60 was suppressed. In contrast to other anticancer compounds, cabazitaxel did not alter the cytoprotective chemoresistance factor HSP27. CONCLUSIONS: Despite the deregulation of microtubule organisation, cabazitaxel has been shown to suppress the expression of HSP. Very notably, and may be as a result of down-regulated HSP, cabazitaxel additionally inhibits the expression of the AR in AR-positive PC cells. Thus, cabazitaxel bears an additional anti-proliferative activity which is at least in part specific for PC cells.

Microvascular and lymphovascular tumour invasion are associated with poor prognosis and metastatic spread in renal cell carcinoma: a validation study in clinical practice.

OBJECTIVE: To validate microvascular (MVI) and lymphovascular (LVI) invasion as prognostic factors in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS: Data of patients with RCC who underwent radical or nephron-sparing surgery were prospectively collected from three academic centres. The occurrence of MVI and LVI was determined with standard staining protocols by experienced pathologists at the time of diagnosis. The association of MVI and LVI with clinicopathological data, metastatic spread, and cancer-specific survival (CSS) were evaluated with Fisher's exact tests, binary logistic regression analyses, and univariable and multivariable Cox proportional hazard regression models. RESULTS: MVI was present in 201 of 747 patients (26.9%) and was associated with advanced Tumour-Node-Metastasis (TNM) stages, high Fuhrman grades, and sarcomatoid features (all P < 0.001). MVI was associated with a higher rate of metastatic spread. LVI was present in 32 of 573 patients (5.5%) and was associated with advanced TNM stages, high Fuhrman grade, and sarcomatoid features (all P < 0.001). Two-thirds of LVI-positive patients died (P < 0.001). Both LVI and MVI were significantly associated with CSS in all patients, clear cell RCC (ccRCC), and localised RCC in univariable analysis (all P < 0.001). On multivariable analysis, presence of MVI was identified as an independent prognostic factor (hazard ratio 2.09; P = 0.001). Moreover, MVI [odds ratio (OR) 2.7; P = 0.001] and not macrovascular invasion (P = 0.895) was an independent predictor of sychronuous metastatic spread. LVI was the strongest factor associated with sychronous metastatic spread (OR 4.73, 95% confidence interval 1.84-12.14; P = 0.001) in all patients and in the subgroup of patients with ccRCC (P = 0.001). CONCLUSIONS: The present study validated LVI and MVI as prognostic factors for poor outcome in RCC. These findings endorse an evaluation of both variables in the clinical routine setting to facilitate survival prognostication in follow-up protocols and for assignment to adjuvant treatment trials.

Shifting cancer care towards Multidisciplinarity: the cancer center certification program of the German cancer society.

BACKGROUND: Over the last decades numerous initiatives have been set up that aim at translating the best available medical knowledge and treatment into clinical practice. The inherent complexity of the programs and discrepancies in the terminology used make it difficult to appreciate each of them distinctly and compare their specific strengths and weaknesses. To allow comparison and stimulate dialogue between different programs, we in this paper provide an overview of the German Cancer Society certification program for multidisciplinary cancer centers that was established in 2003. MAIN BODY: In the early 2000s the German Cancer Society assessed the available information on quality of cancer care in Germany and concluded that there was a definite need for a comprehensive, transparent and evidence-based system of quality assessment and control. This prompted the development and implementation of a voluntary cancer center certification program that was promoted by scientific societies, health-care providers, and patient advocacy groups and based on guidelines of the highest quality level (S3). The certification system structures the entire process of care from prevention to screening and multidisciplinary treatment of cancer and places multidisciplinary teams at the heart of this program. Within each network of providers, the quality of care is documented using tumor-specific quality indicators. The system started with breast cancer centers in 2003 and colorectal cancer centers in 2006. In 2017, certification systems are established for the majority of cancers. Here we describe the rationale behind the certification program, its history, the development of the certification requirements, the process of data collection, and the certification process as an example for the successful implementation of a voluntary but powerful system to ensure and improve quality of cancer care. CONCLUSION: Since 2003, over 1 million patients had their primary tumors treated in a certified center. There are now over 1200 sites for different tumor entities in four countries that have been certified in accordance with the program and transparently report their results from multidisciplinary treatment for a substantial proportion of cancers. This led to a fundamental change in the structure of cancer care in Germany and neighboring countries within one decade.

Exosomal particles secreted by prostate cancer cells are potent mRNA and protein vehicles for the interference of tumor and tumor environment.

BACKGROUND: Remodeling of the tumor environment and the modulation of tumor associated non-malignant cells are essential events in tumor progression. Exosomes are small membranous vesicles of 50-150 nm in diameter, which are secreted into the extracellular space and supposedly serve as vehicles for signal and effector molecules to modulate adjacent target cells. We characterized the mRNA and protein composition as well as cellular functions of prostate cancer cell-derived exosomes. METHODS: Exosomes were prepared from prostate cancer cell culture supernatant by ultracentrifugation and subsequently characterized by dynamic light scattering and electron microscopy. Exosomal mRNA and protein composition were analyzed by DNA microarrays and gel electrophoresis coupled with mass spectrometry. Physiological effects of exosomes were studied by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase release cell assays. Using a SILAC approach, putative uptake of exosomal human proteins in canine cells and canine de novo synthesis of proteins specified by exosome-transferred human mRNA was analyzed in MDCK cells via mass spectrometry. RESULTS: Preparations of exosomes revealed typical cup shaped particles of 150 nm in diameter. Analysis of mRNA and protein composition of exosomes exhibited a wide range of mRNA and protein species. Interestingly, the packaging of at least small proteins into exosomes was apparently unspecific, as shown with the example of two model proteins. In cell culture incubation experiments exosomal preparations of prostate cancer cells caused anti-proliferative effects. MS analysis revealed the uptake of exosomal human proteins into canine cells after 6 hr of incubation. CONCLUSIONS: The results reveal a distinct exosomal functionality in the modulation of the prostatic tumor adjacent environment. The multitude of translocated factors implies the induction of numerous effects in tumor-associated target cells, including impact on cellular growth.

Urological Complications and BK Virus-Associated Diseases Under Allogenic Stem Cell Transplantation.

Every year 50,000 patients receive a stem cell transplantation worldwide, but there is lack of data pertaining to urological complications. METHODS: We performed a retrospective analysis of all adult patients undergoing their first allogenic stem cell transplantation from January 2011 to June 2013 in our institution. Statistical tests performed were Pearson's correlation, chi-square testing and logistic regression using SPSS 22.0. RESULTS: We identified 39 patients (22 males, 17 females). Twenty four patients (61.5%) had a urological complication. Most frequent urologic complications were bacterial urinary tract infection (n = 13; 33.3%), acute renal failure (n = 6; 15.4%) and BK virus-associated haemorrhagic cystitis (n = 5; 12.8%). BK viruria was detected in 12 patients (30.8%). We observed an association of creatinine increase (about 20 µmol/l at time of onset of BK viruria) with BK viruria (Pearson's correlation 0.64; p = 0.01), and BK viruria is significantly linked to acute renal failure (Pearson's correlation 0.35; p = 0.029). In univariate regression, BK viruria is significantly linked to urological complication (p = 0.025). CONCLUSIONS: We suggest that BK virus infection during stem cell transplantation can lead to BK virus associated nephropathy, which is so far only known from patients after kidney transplantation.

Cytochrome P450 17A1 Inhibitor Abiraterone Acetate Counteracts the Heat Shock Protein 27's Cell Survival Properties in Prostate Cancer Cells.

INTRODUCTION: Inhibition of androgen synthesis by abiraterone acetate (AA) entails enhanced overall survival rates and clinical benefit for patients with locally advanced and metastasized prostate cancer (PC). The expression of heat shock protein 27 (HSP27) is generally associated with cytoprotection and was demonstrated to mediate chemoresistance under cytostatic therapy, for instance, docetaxel treatment. In this study, we investigated the impact of AA treatment on HSP27 expression and PC cell growth. MATERIALS AND METHODS: HSP27 expression levels in docetaxel and AA-treated PC cell lines LNCaP and PC-3 were determined by SDS PAGE and Western blot analysis. Proliferation assays were performed using a CASY Cell Counter and Analyzer Model TT (Roche Applied Science). RESULTS: Despite significantly increased HSP27 expression in PC cells incubated with docetaxel, Western blot analysis implicated a significant reduction of the cytoprotective HSP27 in AA-treated PC cells. Notably, HSP27 stably overexpressed in PC-3-HSP27 cells did not appear as an HSP27-mediated proliferation benefit in the presence of AA as shown in docetaxel incubation studies. CONCLUSION: In contrast to repeatedly demonstrated HSP27-driven chemoresistance related to chemotherapeutics, our results may constitute a broader molecular mode of action of AA chemotherapy. AA efficacy may exert an HSP27 suppressive role that goes beyond the primarily assumed inhibition of androgen biosynthesis.

The future therapy of endometrial cancer: microRNA's functionality, capability, and putative clinical application.

PURPOSE: Endometrial cancer (EC) therapy is characterized by the heterogeneity of EC subtypes resulting in unclear clinical behavior as well as in unsatisfactory treatment options. The available biomarkers, such as cellular tumor antigen p53 (TP53), phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and dual-specificity protein phosphatase (PTEN), and phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) genes alone might not be sufficient, and thus, new predictive and prognostic biomarkers are urgently required. The biomolecule class of microRNA represents a group of endogenously expressed regulatory factors primarily involved in control of pivotal cancer-related mechanisms including cell cycle, proliferation, apoptosis, and metastasis. Here, we review the current state of science regarding microRNA functionality in EC progression.

Cardiolipin composition correlates with prostate cancer cell proliferation.

Prostate cancer (PC) is the second most diagnosed cancer in men. It has been recognized that diet can play a crucial role in PC genesis and progression. In this context, free fatty acids are considered as modulators of cell proliferation. Recently, a relationship between the composition of the mitochondrial phospholipid cardiolipin (CL) and cell proliferation has been discussed. The aim of this study was to analyse the interrelationship between CL composition and the proliferation of prostate cells by exposing PC-3 tumour cells to different fatty acids and by analysing the CL composition in prostate tissue from PC patients after prostatectomy. Among the applied fatty acids, palmitic acid was found to stimulate proliferation of PC-3 cells, whereas oleic acid (OA) had an inhibiting effect. The lipidomic analysis of CL revealed that fatty acids supplied to PC-3 cells were incorporated into CL molecules. Further, the CL content of palmitoleic acid (C16:1) exclusively correlated with the proliferation of PC-3 cells. The CL composition significantly differed between tumour and normal prostate tissue from PC patients. In five out of six patients, the CL content of palmitoleic acid was higher in tumour prostate tissue in comparison to normal prostate tissue. Our data illustrate that the composition of CL can be easily modified by the fatty acid environment of cells. OA was most effective in decreasing the amount of palmitoleic acid within the CL molecules and deceleration of PC-3 cell proliferation. In conclusion, a diet rich in OA might be beneficial in protecting from rapid proliferation of PC cells.

Androgen receptor (AR) inhibitor ErbB3-binding protein-1 (Ebp1) is not targeted by the newly identified AR controlling signaling axis heat-shock protein HSP27 and microRNA miR-1 in prostate cancer cells.

PURPOSE: Androgen receptor (AR) networks are predominantly involved in prostate cancer (PCa) progression; consequently, factors of AR regulation represent promising targets for PCa therapy. The ErbB3-binding protein 1 (Ebp1) is linked to AR suppression and chemoresistance by so far unknown mechanisms. In this study, an assumed regulation of Ebp1 by the newly identified AR controlling signaling axis heat-shock protein 27 (HSP27)-microRNA-1 (miR-1) was examined. METHODS: Transfection experiments were carried out overexpressing and knockdown HSP27 and miR-1, respectively, in LNCaP and PC-3 cells. Afterward, HSP27- and miR-1-triggered Ebp1 protein expression was monitored by Western blotting. RESULTS: AR-positive LNCaP cells and AR-negative PC-3 cells possessed diverse basal expression levels of Ebp1. However, subsequent studies revealed no differences in cellular Ebp1 concentrations after modulation of HSP27 and miR-1. Furthermore, docetaxel incubation experiments exhibited no effects on Ebp1 protein synthesis. CONCLUSION: In PCa, Ebp1 has been described as a regulator of AR functionality and as an effector of PCa therapy resistance. Our data suggest that Ebp1 functionality is independent from heat-shock-protein-regulated progression networks in PCa.