Anesthesia Medication's Impacts on Inflammatory and Neuroendocrine Immune Response in Patients Undergoing Digestive Endoscopy.

The aim of this study was to explore the impact of anesthetic drugs currently used to perform lower digestive endoscopy on serum concentrations of inflammation markers and catecholamines. We selected 120 patients and divided them into three lots of 40 patients each: L1, in which no anesthetics were used; L2, in which propofol was used; and L3, in which propofol combined with fentanyl was used. All patients had serum concentrations of adrenaline/epinephrine (EPI), noradrenaline/norepinephrine (NE), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), IL-6, IL-8, and IL-10, taken at three time points: at the beginning of the endoscopic procedure (T0), 15 min after (T1), and 2 h after the end of the endoscopic procedure (T2). The results of the research showed changes in the levels of catecholamines and interleukins (ILs) at T0, with an increased response in L1 above the mean recorded in L2 and L3 (p < 0.001). At T1, increased values were recorded in all lots; values were significantly higher in L1. At T2, the values recorded in L3 were significantly lower than the values in L2 (student T, p < 0.001) and L1, in which the level of these markers continued to increase, reaching double values compared to T0 (student T, p < 0.001). In L2 at T1, the dose of propofol correlated much better with NE, EPI, and well-known cytokines. Our results show that propofol combined with fentanyl can significantly inhibit the activation of systemic immune and neuroendocrine response during painless lower digestive endoscopy.

The Role of Analgesia in the Identification and Treatment of Digestive Tract Lesions: A Randomized, Prospective, Double-Blind Study.

The association of sedation with analgesia in endoscopic procedures represents the ideal combination of anesthetic drugs, which allows these exploratory procedures to be carried out safely, in an outpatient setting. The aim of this study is to compare the results of the use of simple Propofol or Propofol associated with Fentanyl in order to ensure optimal sedation necessary for the detection of benign or malignant lesions of the digestive tract. In this study, 80 patients aged between 18 and 80 years were included, 40 in Group 1 who were administered Propofol alone and 40 in Group 2 in which Propofol was administered associated with Fentanyl. The onset of anesthetic sleep was 19.3±5.1 seconds in Lot 2 versus 29.6±9.1 seconds in Lot 1. The average dose of Propofol used was 203.6±82.8 mg in Lot 1 and in Lot 2 it was lower, 166.3±8.3mg. Cardio respiratory changes were more frequent in Lot 2. The wake-up time was 3.2±1.2 minutes in Lot 1 as a result of the administration of Propofol alone and 7±1.4 minutes in Lot 2. The discharge time was equal for patients in both groups. The degree of postanesthesia safisfaction was 10 for all patients from Lot 2, due to the analgesia provided by the administration of Fentanyl. The use of Propofol associated with Fentanyl in gastrointestinal endoscopic procedures is associated with a rapid recovery of cognitive function at the time of discharge and minimal adverse events, ensuring optimal conditions of analgesia and stability of vital functions.

Modelling the COVID-19 Pandemic Effects on Employees' Health and Performance: A PLS-SEM Mediation Approach.

The COVID-19 pandemic has resulted in the imposition of certain changes in the management of organizations and in the behavior and actions of employees. The purpose of this paper is to investigate the impact of COVID-19 pandemic effects on employees' health and mental well-being, as well as on their working performance. Moreover, the paper aims to highlight whether health- and work-related stress factors mediate the above relations. For the purpose of data collection, a structured questionnaire was used. The first results of the study showed that the pandemic effects felt by employees did not directly affect their mental and physical well-being. On the other hand, the COVID-19 pandemic effects felt by employees affected their general work performance. The findings of the study may provide a useful perspective for organizations and their employees in order to adopt the most effective measures to minimize the effects generated by the pandemic.

Comparative Study of Moderate Sedation with Propofol Versus Propofol Combined with Midazolam for Ambulatory Care Digestive Endoscopic Procedures.

Anesthesia is essential during colonoscopy because it provides patients with necessary sedation to perform the investigation safely and nonetheless to obtain the highest quality of the results. We aimed here to evaluate and establish which of the combinations of anesthetic drugs most frequently used for sedation purposes for gastrointestinal endoscopic procedures performed in the ambulatory best covers the needs of the patient and the gastroenterologist. This is a prospective, randomized, double-blind study carried out on a total of 100 patients, aged between 18 and 80 years, who meet the conditions for inclusion in the study. Patients were randomly allocated into either group A (Propofol) or group B (Midazolam plus Propofol). Evaluation of the dose of Propofol used in the 2 groups, awakening time, anesthetic induction, as well as the occurrence of episodes of bradycardia and hypotension represented the parameters followed in the study. In group A, 50 patients received on average 218.6mg of Propofol in bolus of 10-20mg. In group B, 50 patients received 0.1mg/kg Midazolam and an average of up to 129.2mg of Propofol in bolus of 10-20mg. Awakening time was shorter in group A-3.18 minutes, than in group B-15.7 minutes. Bradycardia and hypotension were met in a larger number in group B than in group A. The quality of the endoscopic evaluation was similar in both groups. The conclusion of our study was that the group to which only Propofol was administered had the best results from all aspects (rapid anesthetic induction, stability of vital functions, lower cost, awakening time much faster) compared to the combination of Propofol with Midazolam.

The interplay between knowledge-based competitiveness, people's good health and well-being: new empirical evidence from Central and Eastern European countries.

The enhancement of countries' competitiveness represents an essential credential in current economic interventions, national policy frameworks and strategies, mainly in relation to sustainable economic development. This paper explores the drivers of competitiveness in Central and Eastern European Countries (CEECs) in the knowledge economy, and its further impact on economic welfare, with a particular focus on individuals' perceived good health and well-being (a good predictor of people's future use of the healthcare system and mortality risk and a benchmark for sustainable development). The dataset grasps 11 CEECs analyzed during the 2000-2018 lapse of time. The methodological endeavor is based on three econometric procedures encompassing macroeconometric models, structural equation modelling (SEM) and network analysis through Gaussian Graphical Models. Main findings entail that CEECs competitiveness is driven by the key coordinates of the knowledge economy, particularly tertiary education, employment in technology and knowledge-intensive sectors, and additional government financial support dedicated for research and development activities. Moreover, in a further complex setting, competitiveness increases under the impact of education, research, development and innovation leads to significant upwards in GDP per capita levels. However, the further linkages with individuals' good health and well-being, when considered as a consequence of welfare increase following knowledge-driven competitiveness, or as a direct impact of competitiveness increases, entail a downsized outcome in terms of individuals' perceived health. Our results provide solid grounds for the development of new tailored policies designed to enhance CEECs knowledge-driven competitiveness in a comprehensive framework, with benefit spillovers on sustainable economic development.

Modeling the Pathways of Knowledge Management Towards Social and Economic Outcomes of Health Organizations.

Despite the increasing emphasis placed on knowledge management (KM) by the business sector and the common belief that creating, acquiring, sharing, and the use of knowledge enable individuals, teams, and communities to achieve superior performance, within the healthcare context, there is still room from improvements from both the theoretical and empirical perspectives. The purpose of this paper is to outline the contribution of KM process to the social- and economic-related outcomes in the context of health organizations. Given the theoretical approach on the considered concepts and their relationships, a conceptual model and seven research hypotheses were proposed. The empirical data were provided by a cross-sectional investigation including 459 medical and nonmedical employees of Romanian heath organizations, selected by a mixed method sampling procedure. A partial least squares structural equation modeling (PLS-SEM) approach was selected to provide information on the relevance and significance of the first- and second-order constructs, test the hypotheses, and conduct an importance performance matrix analysis. The PLS-SEM estimation showed positive and significant relationships between KM process and quality of healthcare, and organizational-level social and economic outcomes. Moreover, the research results provided evidences for the complex complementary mediation of the quality of healthcare and social-related outcomes on the relationships between KM process and social and economic outcomes. The theoretical and managerial implications are discussed and suggestions for future research are provided at the end of the paper.

Induction of endoplasmic reticulum stress by aminosteroid derivative RM-581 leads to tumor regression in PANC-1 xenograft model.

The high fatality and morbidity of pancreatic cancer have remained almost unchanged over the last decades and new clinical therapeutic tools are urgently needed. We determined the cytotoxic activity of aminosteroid derivatives RM-133 (androstane) and RM-581 (estrane) in three human pancreatic cancer cell lines (BxPC3, Hs766T and PANC-1). In PANC-1, a similar level of antiproliferative activity was observed for RM-581 and RM-133 (IC50 = 3.9 and 4.3 µM, respectively), but RM-581 provided a higher selectivity index (SI = 12.8) for cancer cells over normal pancreatic cells than RM-133 (SI = 2.8). We also confirmed that RM-581 induces the same ER stress-apoptosis markers (BIP, CHOP and HERP) than RM-133 in PANC-1 cells, pointing out to a similar mechanism of action. Finally, these relevant in vitro results have been successfully translated in vivo by testing RM-581 using different doses (10-60 mg/kg/day) and modes of administration in PANC-1 xenograft models, which have led to tumor regression without any sign of toxicity in mice (animal weight, behavior and histology). Interestingly, RM-581 fully reduced the pancreatic tumor growth when administered orally in mice.

Altered expression of different GalNAc­transferases is associated with disease progression and poor prognosis in women with high-grade serous ovarian cancer.

Protein glycosylation perturbations are implicated in a variety of diseases, including cancer. Aberrant glycosylation in cancer is frequently attributed to altered expression of polypeptide GalNAc transferases (GalNAc­Ts) - enzymes initiating mucin-type O-glycosylation. A previous study from our group demonstrated that one member of this family (GALNT3) is overexpressed in epithelial ovarian cancer (EOC), and GALNT3 expression correlated with shorter progression-free survival (PFS) in EOC patients with advanced disease. As considerable degree of redundancy between members of the GalNAc­Ts gene family has been frequently observed, we decided to investigate whether other members of this family are essential in EOC progression. In silico analysis based on publically available data was indicative for altered expression of five GalNAc­Ts (GALNT2, T4, T6, T9 and T14) in ovarian high-grade serous carcinoma (HGSC) samples compared to non-tumoral (control) ovarian tissue. We analyzed protein expression of these GalNAc­Ts in EOC cells and tumors by western blotting, followed by immunohistochemical (IHC) evaluation of their expression in EOC tumor and control samples using tissue microarrays (TMAs). Western blot analyses were indicative for low expression of GALNT2 and strong expression of GALNT6, T9 and T14 in both EOC cells and tumors. These observations were confirmed by IHC. GALNT2 displayed significantly lower expression, while GALNT6, GALNT9 and GALNT14 showed significantly higher expression in HGSC tumors compared to control tissue. Importantly, GALNT6 and GALNT14 expression correlated with poor prognosis of serous EOC patients. Moreover, our results suggest for overlapping functions of some GalNAc­Ts, more specifically GALNT3 and GALNT6, in directing EOC progression. Our results are indicative for a possible implication of different members of the GalNAc­T gene family in modulating EOC progression, and the potential use of GALNT6 and GALNT14 as novel prognostic EOC biomarkers. These data warrant future studies on the role of members of the GalNAc­Ts gene family in ovarian tumorigenesis.

Divergent Expression and Metabolic Functions of Human Glucuronosyltransferases through Alternative Splicing.

Maintenance of cellular homeostasis and xenobiotic detoxification is mediated by 19 human UDP-glucuronosyltransferase enzymes (UGTs) encoded by ten genes that comprise the glucuronidation pathway. Deep RNA sequencing of major metabolic organs exposes a substantial expansion of the UGT transcriptome by alternative splicing, with variants representing 20% to 60% of canonical transcript expression. Nearly a fifth of expressed variants comprise in-frame sequences that may create distinct structural and functional features. Follow-up cell-based assays reveal biological functions for these alternative UGT proteins. Some isoforms were found to inhibit or induce inactivation of drugs and steroids in addition to perturbing global cell metabolism (energy, amino acids, nucleotides), cell adhesion, and proliferation. This work highlights the biological relevance of alternative UGT expression, which we propose increases protein diversity through the evolution of metabolic regulators from specific enzymes.

Validation of EP1 Antibody Clone for Estrogen Receptor Immunohistochemistry for Breast Cancer.

BACKGROUND: SP1 Rabbit monoclonal antibody to estrogen receptor (ER) has long been the standard for determination of ER status in breast cancer but has been replaced by the rabbit EP1 clone. AIM: To validate the EP1 antibody clone for use in determination of breast cancer ER status in a large clinical population against the previous standard SP1. MATERIALS AND METHODS: ER immunohistochemistry was assessed in 523 consecutive cases from a clinical setting using tissue microarrays. RESULTS: The kappa statistic showed that the agreement of ER status between SP1 and EP1 was considered to be almost perfect (kappa=0.97, 95% confidence interval=0.94-1.00). Sensitivity was 99.3%, specificity was 98.6% and overall agreement was 99.2%. CONCLUSION: The EP1 antibody was herein validated regarding its use in breast cancer with almost perfect agreement with the previously used standard SP1 antibody.

Pathologic response and long-term follow-up in breast cancer patients treated with neoadjuvant chemotherapy: a comparison between classifications and their practical application.

CONTEXT: Breast cancer is increasingly treated with neoadjuvant chemotherapy to improve surgical resectability and evaluate tumor response, which is assessed histopathologically. Several histopathologic classification systems have been previously described for assessment of treatment response. OBJECTIVES: To test performance in a side-by-side comparison of several histopathologic classification systems after neoadjuvant chemotherapy with clinical outcome. DESIGN: Sixty-two patients were enrolled in a randomized trial receiving sequential neoadjuvant chemotherapy with doxorubicin and paclitaxel. Histologic sections from the patients' tumors sampled before (core biopsy) and after treatment (excision or mastectomy) were reviewed. Histologic response was assessed following National Surgical Adjuvant Breast and Bowel Project protocol B18, Miller-Payne grading, Sataloff tumor and nodes, Residual Cancer Burden (RCB), and Residual Disease in Breast and Nodes (RDBN). Pathologic classification results were correlated with survival using Kaplan-Meier and Cox hazards regression with a median follow-up of 93 months. RESULTS: RDBN was associated with distant disease-free survival by univariate and multivariate analysis (P = .01 and .004, respectively), as were lymph node metastases (P = .02 and .01, respectively). Five patients (8%) had complete pathologic response after neoadjuvant chemotherapy, and none of them relapsed during the study period. Survival was shorter among patients with higher Residual Cancer Burden scores, but the associations were not significant. Miller-Payne grading and Sataloff tumor scores were not correlated with survival. CONCLUSIONS: Evaluation of breast specimens after neoadjuvant chemotherapy by the composite index RDBN correlates with long-term outcome. The residual disease in breast and nodes system is suitable for routinely processed pathology cases. This study confirms the importance of lymph node status after neoadjuvant chemotherapy and favorable outcome in patients with pathologic complete response.

Value of sentinel node mapping in cancer of the cervix.

OBJECTIVES: To compare the relative value of two methods of detection for the sentinel lymphatic nodes (SLNs): colorimetric with Isosulfan blue (ISB) and radio-isotopic with Technetium-99 (Tc99), and to evaluate the concept of the SLN mapping applied to cervical cancer. METHODS: From October 2000 to December 2006, radical surgery was planned in 211 patients who presented early-stage cancer of the cervix. Both ISB and Tc99 were used to detect the SLNs. In all cases, we proceeded with laparoscopy for the identification and removal of the SLNs, followed by a complete pelvic lymphadenectomy with or without para-aortic node sampling. The SLNs were sent for frozen section (1 level) and were ultra-staged (6 levels) for final pathology. Detection rate, sensitivity and negative predictive value (NPV) were calculated. RESULTS: Among the 211 patients, ISB (n=152) identified at least 1 SLN in 92.8% of the cases. With Tc99 (n=166), the detection rate of SLN increased to 96.9%. When both techniques were used together (n=107), Tc99 was significantly better than ISB by 7.8% (p=0.0094) and at least 1 SLN (hot and/or blue) was found in 99.1% of the cases. In 16.7% of patients, a SLN was located in aberrant sites, including 3.8% in the para-aortic area. Thirty-three out of the 211 patients (15.6%) had lymph node metastases. When considering only the 181 patients with bilateral SLNs identified, the NPV of SLN is 100% after ultra staging on final pathology and 94.2% on frozen section (FS). CONCLUSION: Sentinel node mapping is feasible using laparoscopy. The radio-isotopic technique adds significantly to the rate of detection. The main benefits of SLN mapping in cervical cancer are the detection of micro-metastases on ultra staging which might be missed on routine pathological evaluation, and identification of aberrant drainage sites. However, the current frozen section techniques lack sensitivity to identify very small metastases and need refinement. SLN mapping should become the standard of care in the modern management of cervical cancer and complete pelvic lymphadenectomy could be avoided when bilateral SLNs are detected in patients with lesions less than 2 cm.

Immunohistochemical expression of conjugating UGT1A-derived isoforms in normal and tumoral drug-metabolizing tissues in humans.

Glucuronidation by UDP-glucuronyltransferase (UGT) enzymes is the prevailing conjugative pathway for the metabolism of both xenobiotics and endogenous compounds. Alterations in this pathway, such as those generated by common genetic polymorphisms, have been shown to significantly impact on the health of individuals, influencing cancer susceptibility, responsiveness to drugs and drug-induced toxicity. Alternative usage of terminal exons leads to UGT1A-derived splice variants, namely the classical and enzymatically active isoforms 1 (i1) and the novel enzymatically inactive isoforms 2 (i2). In vitro functional data from heterologous expression and RNA interference experiments indicate that these i2 isoforms act as negative modulators of glucuronidation, likely by forming inactive complexes with active isoform 1. We used specific antibodies against either active i1 or inactive i2 proteins to examine their distribution in major drug-metabolizing tissues. Data revealed that UGT1A_i1 and inactive UGT1A_i2 are co-produced in the same tissue structures, including liver, kidney, stomach, intestine and colon. Examination of the cellular distribution and semi-quantitative level of expression of UGT1As revealed heterogeneous expression of i1 and i2 proteins, with increased expression of i2 in liver tumours and decreased levels of i1 and i2 in colon cancer specimens, compared to normal tissues. These differences in expression may be relevant to human colon and liver cancer tumorigenesis. Our data clearly demonstrate the similar immunolocalization of active and inactive UGT1A isoforms in most UGT1A-expressing cell types of major tissues involved in drug metabolism. These expression patterns are consistent with a dominant-negative function for the i2 encoded by the UGT1A gene.

Immunohistochemical analysis of possible chemoresistance markers identified by micro-arrays on serous ovarian carcinomas.

Using the DNA microarray technology, we have identified genes that are differentially expressed in chemosensitive and chemoresistant ovarian serous papillary carcinomas and could potentially distinguish ovarian cancer patients based on their response to chemotherapy. The present study aims to evaluate the clinical usefulness of overexpression of selected genes by immunohistochemistry. Our cohort included 158 women who were operated on and received chemotherapy for an advanced serous papillary ovarian carcinoma (FIGO stages III and IV). The end point used in this study was progression-free survival. Immunohistochemistry was performed on microarray blocks containing all 158 cases. Twelve commercially available antibodies were selected. Of them, 10 corresponded to differentially expressed genes in our micro-array study and p53 and Ki67 were included. Antibodies were obtained for the following selected genes: GSTA1, MMP1, FOSB, CTSL2, HSP10, CD36, CXCL2, RBBP7, Siva, and PTGDS. Cox proportional hazards models, adjusted for standard risk factors, were used to estimate the associations between the markers and progression-free survival. No association was found between mRNA level and protein expression by immunohistochemistry. In multivariate analyses, patients whose tumors overexpressed HSP10 had a lower risk of progression than those with low expression (HR: 0.6; CI: 0.42-0.87; P=0.007). High level of proliferation (Ki67) tended to be associated with a lower risk of progression (HR: 0.72; CI: 0.51-1.03; P=0.07) whereas MMP1 overexpression tended to be associated with a higher risk of progression (HR: 1.61; CI: 0.94-2.79; P=0.08). Our study shows that gene expression analysis coupled with immunohistochemistry allowed the identification of HSP10 as an independent factor of progression-free survival.

Identification of PCA3 (DD3) in prostatic carcinoma by in situ hybridization.

PCA3 is a specific marker of prostatic carcinoma. However, PCA3 has been detected only at RNA level and a corresponding PCA3 protein has never been identified. The aim of this study was to develop a technique capable of detecting PCA3 RNA on histology sections and to assess the cellular location of the molecule. Forty-eight formalin-fixed paraffin-embedded blocks of prostatectomy specimens were selected for PCA3 detection by in situ hybridization by both radioactive and chromogenic methods. Of the 48 sections, 28 contained prostatic adenocarcinoma and 20 had benign tissue located distant from the tumor. Using the radioactive detection method, 26 of 28 available cases (93%) of cancers presented at least focal cytoplasmic PCA3 expression. The benign glands located in proximity of the cancer presented PCA3 expression in eight (29%) cases, whereas those situated distant to the tumor showed focal expression in 2 of 20 (10%) cases only. High-grade prostatic intraepithelial neoplasia (HGPIN) expressed PCA3 in 25 of 26 (96%) cases. With the chromogenic detection method, 22 of the 24 interpretable cases (92%) of cancers had at least focal cytoplasmic staining. Benign glands located close to neoplastic glands expressed PCA3 in 8 (33%) cases, but none of those distant to the tumor expressed the marker. HGPIN was positive in 17 of 24 (71%) cases. The sensitivity, specificity, positive predictive value and negative predictive value for the detection of cancer were 93, 79, 71 and 95% for the radioactive detective method and 92, 80, 71 and 95% for the chromogenic detection method, respectively. Our study shows that PCA3 RNA is expressed by most prostate cancers and HGPIN. Normal glands rarely express the marker, except those located in immediate proximity of neoplastic glands, suggesting the presence of precursor molecular changes.

Gene expression patterns of chemoresistant and chemosensitive serous epithelial ovarian tumors with possible predictive value in response to initial chemotherapy.

Chemotherapy (CT) resistance in ovarian cancer is broad and encompasses diverse, unrelated drugs, suggesting more than one mechanism of resistance. We aimed to analyze the gene expression patterns in primary serous epithelial ovarian cancer (EOC) samples displaying different responses to first-line CT in an attempt to identify specific molecular signatures associated with response to CT. Initially, the expression profiles of 15 chemoresistant serous EOC tumors [time to recurrence (TTR) or =30 months) were independently analyzed which allowed the identification of specific sets of differentially expressed genes that might be functionally implicated in the evolution of the chemoresistant or the chemosensitive phenotype. Our data suggest that the intrinsic chemoresistance in serous EOC cells may be attributed to the combined action of different molecular mechanisms and factors linked with drug influx and efflux and cell proliferation, as possible implications of other molecular events including altered metabolism, apoptosis and inflammation cannot be excluded. Next, gene expression comparison using hierarchical clustering clearly distinguished chemosensitive and chemoresistant tumors from the 25 serous EOC samples (training set), and consecutive class prediction analysis was used to develop a 43-gene classifier that was further validated in an independent cohort of 15 serous EOC patients and 2 patients with other ovarian cancer histotypes (test set). The 43-gene predictor set properly classified serous EOC patients at high risk for early (< or =22 months) versus late (>22 months) relapse after initial CT. Thus, gene expression array technology can effectively classify serous EOC tumors according to CT response. The proposed 43-gene model needs further validation.

Negative sentinel lymph node accurately predicts negative status of pelvic lymph nodes in uterine cervix carcinoma.

OBJECTIVE: The significance of negative sentinel lymph nodes (SLN) is important in the staging and treatment of melanoma and a few other cancers, but is controversial in uterine cervix carcinoma. Our study was aimed at correlating the SLN status in cervical carcinoma with non-sentinel lymph nodes (non-SLN), in a uniform and well controlled population. METHODS: This study includes 36 patients with stage I and IIA cervical carcinoma and bilaterally negative SLN on final pathology. SLN were identified using blue dye and radioisotopic techniques. Frozen section examination was performed for all SLN; the rest of the tissue was formalin fixed and paraffin embedded. The protocol used for SLN was also applied for non-SLN. For each block, six 4-micro m thick sections were cut at 40 micro m intervals and stained with H and E; an additional section taken between the 3rd and 4th levels was imunostained using AE1/AE3 cytokeratin. RESULTS: The mean age for the study population was 39 years (range 25-76); the number of SLN ranged from 2 to 6 (mean 2.7) and the non-SLN from 8 to 49 (mean 23) per case. No metastasis was found in any SLN and non-SLN by step sections and IHC. CONCLUSION: Our study demonstrates that bilaterally negative SLN on final pathology accurately predict the absence of metastases in non-SLN in cervical carcinoma. If confirmed by larger trials, these results may influence the clinical management of early cervical cancer.

Gene expression profiling of paired ovarian tumors obtained prior to and following adjuvant chemotherapy: molecular signatures of chemoresistant tumors.

Chemotherapy (CT) resistance in ovarian cancer is related to multiple factors, and assessment of these factors is necessary for the development of new drugs and therapeutic regimens. In an effort to identify such determinants, we evaluated the expression of approximately 21,000 genes using DNA microarray screening in paired tumor samples taken prior to and after CT treatment from 6 patients with predominantly advanced stage, high-grade epithelial ovarian cancer. A subset of differentially expressed genes was selected from all microarray data by initial filtering on confidence at p=0.05, followed by filtering on expression level (>or=2-fold). Using these selection criteria, we found 121 genes to be commonly up-regulated and 54 genes to be down-regulated in the post-CT tumors, compared to primary tumors. Up-regulated genes in post-CT tumors included substantial number of genes with previously known implication in mechanisms of chemoresistance (TOP2A, ETV4, ABCF2, PRDX2, COX2, COX7B, MUC1, MT3, MT2A), and tumorigenesis (SCGB2A2, S100A9, YWHAE, SFN, ATP6AP1, MGC5528, ASS, TACC3, ARHGAP4, SRA1; MGC35136, PSAP, SPTAN1, LGALS3BP, TUBA4, AMY2B, PPIA, COX1, GRB2, CTSL). Down-regulated genes in post-CT samples mostly included genes implicated in chemosensitivity (GRP, TRA1, ADPRTL1, TRF4-2), cell proliferation and cell cycle control (NGFRAP1, TPD52L1, TAX1BP1) and tumor suppression and apoptosis (SMOC2, TIMP3, AXIN1, CASP4, P53SCV). Additionally, gene clustering analysis revealed the existence of two distinct expression signatures of chemoresistant tumors, which was further confirmed by assessment of some genetic (p53 gene mutation status) and clinical parameters (CT regimens). Our data suggest that intrinsic and acquired chemoresistant phenotypes of post-CT tumors may be attributed to the combined action of different factors implicated in mechanisms of chemoresistance, tumor invasion/progression and control of cell proliferation. This type of molecular profiling could have important clinical implications in resolving chemoresistance and the development of novel treatment strategies designed to prevent its emergence.