Faculty perceptions of factors that indicate successful educational outcomes of medical students' research projects: a focus group study.

BACKGROUND: A growing number of medical schools have individual scholarly projects as a component of their curricula. The fact that all students, and not only those with research interests, have to carry out a project puts high demands on the projects and their supervision. Evidence is lacking for how to produce scholarly projects with satisfactory outcomes. This study aimed to explore the observations of faculty teachers regarding factors that predict the educational outcomes of medical students' scholarly projects. METHODS: Two focus group interviews were held with seven of the 16 faculty coordinators who were external reviewers of students' research projects. The audio-recorded interview transcripts were analyzed using qualitative content analysis. We employed a constant comparative approach to create categories firmly grounded in the participants' experiences. A successful project was defined as coordinators' perception that the stated learning outcomes were achieved, in terms of students' ability to demonstrate a scientific attitude. RESULTS: Five categories emerged from the data: Supervision, Project setup, Student characteristics, Curriculum structure, and Institutional guidance. The supervisors' experience and availability to students were mentioned as key factors for successful outcomes. Further, a clear aim and adaptation to the time frame were stated to be project-related factors that were also supervisors' responsibilities. Important student-related factors were skills related to scientific writing, taking ownership of and managing the projects, and making use of feedback. Finally, the course requirements, support, and control accomplished by faculty coordinators played important roles. CONCLUSIONS: Contributing factors to achievement of the learning outcomes were supervisors' commitment and experience, and the projects being suitable for the time frame and having a clearly stated research question. Furthermore, the students' prowess at scientific writing, adequate handling of feedback, and ability to assume ownership of the project contributed to the final outcome, as did adherence to curricular instructions.

PGC1α and VDAC1 expression in endometrial cancer.

Endometrial cancer (EC) is one of the ten most common gynecological cancers. As in most cancers, EC tumour progression involves alterations in cellular metabolism and can be associated with, for instance, altered levels of glycolytic enzymes. Mitochondrial functions and proteins are known to serve key roles in tumour metabolism and progression. The transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1α) is a major regulator of mitochondrial biogenesis and function, albeit of varying prognostic value in different cancers. The voltage-dependent anion channel type 1 (VDAC1) regulates apoptosis as well as metabolite import and export over the mitochondrial outer membrane, and is often used for comparative quantification of mitochondrial content. Using immunohistochemistry, the present study examined protein expression levels of PGC1α and VDAC1 in tumour and paired benign tissue samples from 148 patients with EC, in order to examine associations with clinical data, such as stage and grade, Ki-67, p53 status, clinical resistance and overall survival. The expression levels of both PGC1α and VDAC1, as well as a PGC1α downstream effector, were significantly lower in tumor tissues than in benign tissues, suggesting altered mitochondrial function in EC. However, Kaplan-Meier, log rank and Spearman's rank correlation tests revealed that their expression was not correlated with survival and clinical data. Therefore, PGC1α and VDAC1 are not of major prognostic value in EC.

A Shifty Target: Tumor-Initiating Cells and Their Metabolism.

Tumor-initiating cells (TICs), or cancer stem cells, constitute highly chemoresistant, asymmetrically dividing, and tumor-initiating populations in cancer and are thought to play a key role in metastatic and chemoresistant disease. Tumor-initiating cells are isolated from cell lines and clinical samples based on features such as sphere formation in stem cell medium and expression of TIC markers, typically a set of outer membrane proteins and certain transcription factors. Although both bulk tumor cells and TICs show an adaptive metabolic plasticity, TIC metabolism is thought to differ and likely in a tumor-specific and growth condition-dependent pattern. In the context of some common solid tumor diseases, we here review reports on how TIC isolation methods and markers associate with metabolic features, with some focus on oxidative metabolism, including fatty acid and lipid metabolism. These have emerged as significant factors in TIC phenotypes, and in tumor biology as a whole. Other sections address mitochondrial biogenesis and dynamics in TICs, and the influence of the tumor microenvironment. Further elucidation of the complex biology of TICs and their metabolism will require advanced methodologies.

Does reality meet expectations? An analysis of medical students' expectations and perceived learning during mandatory research projects.

BACKGROUND: Although much has been written about structure and outcomes of medical students' curricular research projects, less attention has been paid to the expectations on such projects. In order to foster students' scientific understanding and improve the quality of mandatory research projects, we compared students' pre-course expectations with their post-course insights regarding learning and transferable skills. METHODS: A prospective cross-sectional questionnaire study. All students registered on a mandatory 20-week research project course in 2011-2013 were e-mailed questionnaires in the beginning and after the course asking them to rate statements on expectations and perceived learning on a 5-point Likert scale. Of 652 students, 358 (mean age 26 years; range 21-49; 63% females) returned both questionnaires, corresponding to a response rate of 55%. RESULTS: The ratings for expectations as well as perceived learning were highest for learning to search and critically appraise literature. The greatest pre- and post-course differences were indicated for participation in scientific discussions and oral communication. Surprisingly, both pre- and post-course ratings were low for research ethics. The highest post-course ratings regarding skills for future working life were given to items pertaining to understanding the scientific basis of medicine, ability to follow the development of knowledge and to critically integrate knowledge. Female students had higher expectations than male students. Those with a previous university degree had lower ratings of expectations and perceived learning. Students with basic science projects reported higher expectations and higher learning compared to students with other projects. Previous research experience had no significant influence on expectations nor learning. The correlations between post-course ratings of learning and skills showed that problem-solving ability had a relatively high correlation with all skills. CONCLUSIONS: Students had high expectations and perceived the course improved crucial practical skills. However, expectations were not quite met regarding aspects of scientific communication, and hypothesis formulation, likely because these require more extensive practice and feedback. Students should be actively involved in ethical discussions and oral communication should be trained repeatedly as it is an important task of doctors to communicate scientific information to patients and non-experts.

PGC1α: Friend or Foe in Cancer?

The PGC1 family (Peroxisome proliferator-activated receptor γ (PPARγ) coactivators) of transcriptional coactivators are considered master regulators of mitochondrial biogenesis and function. The PGC1α isoform is expressed especially in metabolically active tissues, such as the liver, kidneys and brain, and responds to energy-demanding situations. Given the altered and highly adaptable metabolism of tumor cells, it is of interest to investigate PGC1α in cancer. Both high and low levels of PGC1α expression have been reported to be associated with cancer and worse prognosis, and PGC1α has been attributed with oncogenic as well as tumor suppressive features. Early in carcinogenesis PGC1α may be downregulated due to a protective anticancer role, and low levels likely reflect a glycolytic phenotype. We suggest mechanisms of PGC1α downregulation and how these might be connected to the increased cancer risk that obesity is now known to entail. Later in tumor progression PGC1α is often upregulated and is reported to contribute to increased lipid and fatty acid metabolism and/or a tumor cell phenotype with an overall metabolic plasticity that likely supports drug resistance as well as metastasis. We conclude that in cancer PGC1α is neither friend nor foe, but rather the obedient servant reacting to metabolic and environmental cues to benefit the tumor cell.

Medical students' perceptions of their learning environment during a mandatory research project.

OBJECTIVES: To explore medical students´ perceptions of their learning environment during a mandatory 20-week scientific research project. METHODS: This cross-sectional study was conducted between 2011 and 2013. A total of 651 medical students were asked to fill in the Clinical Learning Environment, Supervision, and Nurse Teacher (CLES+T) questionnaire, and 439 (mean age 26 years, range 21-40, 60% females) returned the questionnaire, which corresponds to a response rate of 67%. The Mann-Whitney U test or the Kruskal-Wallis test were used to compare the research environments. RESULTS: The item My workplace can be regarded as a good learning environment correlated strongly with the item There were sufficient meaningful learning situations (r= 0.71, p<0.001). Overall satisfaction with supervision correlated strongly with the items interaction (r=0.78, p < 0.001), feedback (r=0.76, p<0.001), and a sense of trust (r=0.71, p < 0.001).  Supervisors´ failures to bridge the gap between theory and practice or to explain intended learning outcomes were important negative factors.  Students with basic science or epidemiological projects rated their learning environments higher than did students with clinical projects (χ2(3, N=437)=20.29, p<0.001). CONCLUSIONS: A good research environment for medical students comprises multiple meaningful learning activities, individual supervision with continuous feedback, and a trustful atmosphere including interactions with the whole staff.  Students should be advised that clinical projects might require a higher degree of student independence than basic science projects, which are usually performed in research groups where members work in close collaboration.

Medical students' research productivity and career preferences; a 2-year prospective follow-up study.

BACKGROUND: Linking undergraduate medical education to scientific research is necessary for the quality of future health care, and students´ individual research projects are one way to do so. Assessment of the impact of such projects is of interest for both educational and research-oriented segments of medical schools. Here, we examined the scholarly products and medical students' career preferences 2 years after a mandatory research project course. METHODS: A prospective cross-sectional questionnaire study. All 581 students registered on a 20-week research project course between September 2010 through September 2012 were e-mailed a questionnaire 2 years after completing the course. RESULTS: In total, 392 students (mean age 27 years; 60% females) responded (67% response rate). 59 students (15%) were co-authors on a scientific paper published in an international journal, 6 students had published in a national journal, and 57 students had co-authored a paper submitted for publication. Totally, 122 scientific papers had been submitted. Moreover, 67 (17%) students had given 107 oral or poster presentations nationally or internationally during the follow-up. Career-wise, 36 students (9%) had been registered as PhD students and an additional 127 students (34%) were planning to register. Those who did not plan doctoral studies were significantly older (p = 0.013) than those who did. However, 35% reported that they would in the coming 5 years prefer to work as clinicians only, and this group was significantly younger than those who envisaged participation in research. There were no significant gender differences. CONCLUSIONS: Approximately a third of the students had authored papers and/or public presentations, and a similar fraction had career plans involving a PhD degree. The results indicate that the project course had a positive impact on continued supervisor-student collaboration on a professional level, but also that strategies to encourage young doctors to perform clinical research may be needed.

On mitochondrial metabolism in tumor biology.

PURPOSE OF REVIEW: To provide examples of mitochondria-specific metabolic events that influence tumor cell biology, and of metabolism-related mitochondrial biomarkers and therapeutic targets in cancer cells. RECENT FINDINGS: Cancer cell mitochondria are rewired to optimally serve the cancer cell under various conditions of cellular stress. The nonexhaustive list of mitochondrial alterations that support cancer cell proliferation, survival, and/or progression includes upregulation of oxidative metabolism and use of alternative substrates, oncometabolites, increased superoxide production, mutated mitochondrial DNA, and altered mitochondrial morphology and dynamics. Potential therapeutic targets include fatty acid oxidation, voltage-dependent anion channel-1, the pyruvate dehydrogenase complex, and Complex I. SUMMARY: Some phenotypical traits, for example, chemoresistance and metastasis, are likely regulated by a fine-tuned balance between several metabolic processes and events that are upregulated in parallel and are also dependent on microenvironmental cues. Many metabolism-related mitochondrial biomarkers show prognostic value, but the biological interpretation of the data may be confounded by the overall metabolic status and context. Understanding metabolic regulation of stemness is important for targeting cancer stem cells. Therapeutic targeting of cancer cell mitochondria remains experimental but promising, and more predictive markers will be needed for metabolism-based treatments and personalized medicine.

What is the reward? Medical students' learning and personal development during a research project course.

BACKGROUND: Until recently, the outcome of medical students' research projects has mainly been assessed in terms of scientific publications, whereas other results important for students' development have been less studied. The aim of this study was to investigate medical students' experiences of learning as an outcome of the research project course. METHOD: Written reflections of 50 students were analyzed by manifest inductive content analysis. RESULTS: Three categories emerged: 'thinking as a scientist', 'working as a scientist', and 'personal development'. Students became more aware about the nature of knowledge, how to generate new knowledge, and developed skills in scientific thinking and critical appraisal. Unexpectedly, effects on personal characteristics, such as self-confidence, self-discipline, independence, and time management skills were also acknowledged. CONCLUSIONS: We conclude that individual research projects enhance research-specific skills and competencies needed in evidence-based clinical work and are beneficial for personal and professional development.

[The supervisor has a crucial role in the medical student's degree projects. Experiences from seven semesters at Karolinska Institutet]. / Handledaren har avgörande roll för läkar-studentens examensarbete--KI:s erfarenheter från sju terminer.

In Sweden degree projects have a central role in evaluation of higher education, wherefore significant resources are spent on developing students' research competence. The undergraduate medical program at Karolinska Institutet introduced its degree project course in 2010. This paper gives an overview of the course and summarizes experiences from the first seven terms. In order to finalize their projects within one term, most students need substantial support. A highly structured course and frequent progress monitoring are advantageous. Other crucial factors are the quality of the supervision and students' verbal skills as well as support in scientific writing. In addition, increased awareness of the learning outcomes already at the beginning of the course may help students to achieve the expected results. Finally, students need to recognize their own responsibility for learning. 

Metabolic profiling of epithelial ovarian cancer cell lines: evaluation of harvesting protocols for profiling using NMR spectroscopy.

BACKGROUND: Metabolic profiling represents a novel technology for analyzing tumor cells. Epithelial ovarian carcinoma has a low survival rate due to the development of aggressive and chemotherapy-resistant cells. A tailored and reliable protocol is presented for profiling of chemoresistant cells using the cell line SKOV3 and a multiresistant subline SKOV3R. RESULTS: Harvesting protocols with cold methanol or MilliQ freeze/thaw cycles were compared. Increased reproducibility using MilliQ was evidenced. Importantly, both approaches resulted in similar profiles. Compared with parental SKOV3, the SKOV3R cells showed a significantly different profile. CONCLUSION: The MilliQ protocol is preferred owing to higher reproducibility and increased sample preparation options. The resulting metabolic profiles summarize metabolic alterations in chemoresistant cells consistent with a progressed and aggressive phenotype.

Expression of mitochondrial regulators PGC1α and TFAM as putative markers of subtype and chemoresistance in epithelial ovarian carcinoma.

Epithelial ovarian carcinoma (EOC), the major cause of gynaecological cancer death, is a heterogeneous disease classified into five subtypes. Each subtype has distinct clinical characteristics and is associated with different genetic risk factors and molecular events, but all are treated with surgery and platinum/taxane regimes. Tumour progression and chemoresistance is generally associated with major metabolic alterations, notably altered mitochondrial function(s). Here, we report for the first time that the expression of the mitochondrial regulators PGC1α and TFAM varies between EOC subtypes; furthermore, we have identified a profile in clear-cell carcinoma consisting of undetectability of PGC1α/TFAM, and low ERα/Ki-67. By contrast, high-grade serous carcinomas were characterised by a converse state of PGC1α/TFAM, ERα positivity and a high Ki-67 index. Interestingly, loss of PGC1α/TFAM and ERα was found also in a non-clear cell EOC cell line made highly resistant to platinum in vitro. Similar to clear-cell carcinomas, these resistant cells also showed accumulation of glycogen. Altogether, our data provide mechanistic insights into the chemoresistant nature of ovarian clear-cell carcinomas. Furthermore, these findings corroborate the need to take into account the diversity of EOC and to develop subtype specific treatment strategies.

Metabolic markers and HSP60 in chemonaive serous solid ovarian cancer versus ascites.

OBJECTIVE: Metabolic pathway alterations in cancer are thought to be dependent upon tumor type-specific oncogenic activation and local nutrient and oxygen supply during disease progression. In serous ovarian cancer, the typical peritoneal spread of disease is caused by shedding of tumor cells into the abdominal cavity, often along with ascites formation. Not much is known about the metabolic features of these detached serous tumor cells. In this study, we investigate the messenger RNA (mRNA) expression of GAPDH (glycolytic glyceraldehyde 3-phosphate dehydrogenase) and PKM2 (pyruvate kinase isoform M2), ATP5B (mitochondrial ß-F1-ATPase), and heat shock protein 60 in matched serous solid tumor and corresponding ascites. MATERIALS/METHODS: Fresh samples from solid tumor and corresponding ascites were prospectively collected from 40 patients undergoing primary surgery for suspected advanced ovarian cancer. Of these, 25 met the study eligibility criteria, that is, stage IIC to IV disease of the serous (24) or endometrioid (1) subtype with solid and ascites specimens containing 50% or more tumor cells and with good quality and quantity mRNA yield. All but 2 patients (92%) had type II disease. GAPDH, PKM2, ATP5B, and HSP60 mRNA expressions were assessed by real-time polymerase chain reaction. For each marker, the mRNA expression in solid tumor was pairwise compared with the corresponding expression in ascites using the Wilcoxon matched pairs signed rank sum test. RESULTS: In contrast to our hypothesis, the mRNA expression of analyzed metabolic markers and HSP60 did not significantly differ between matched solid tumor and malignant ascites. CONCLUSIONS: Our results indicate that further expression changes in genes related to glycolysis or oxidative phosphorylation are not a prerequisite for serous cancer cell survival after detachment.

Cisplatin and oxaliplatin are toxic to cochlear outer hair cells and both target thioredoxin reductase in organ of Corti cultures.

CONCLUSION: Inhibition of thioredoxin reductase (TrxR) may be a contributing factor in cisplatin-induced ototoxicity. Direct exposure of organ of Corti to cisplatin and oxaliplatin gives equal loss of hair cells. OBJECTIVES: Platinum-containing drugs are known to target the anti-oxidant selenoprotein TrxR in cancer cells. Two such anti-cancer, platinum-containing drugs, cisplatin and oxaliplatin, have different side effects. Only cisplatin induces hearing loss, i.e. has an ototoxic side effect that is not seen after treatment with oxaliplatin. The objective of this study was to evaluate if TrxR is a target in the cochlea. Loss of outer hair cells was also compared when cisplatin and oxaliplatin were administered directly to the organ of Corti. METHODS: Organ of Corti cell culture was used for direct exposure to cisplatin and oxaliplatin. Hair cells were evaluated and the level of TrxR was assessed. Immunohistochemical staining for TrxR was performed. An animal model was used to evaluate the effect on TrxR after treatment with cisplatin and oxaliplatin in vivo. RESULTS: Direct exposure of cochlear organotypic cultures to either cisplatin or oxaliplatin induced comparable levels of outer hair cell loss and inhibition of TrxR, demonstrating that both drugs are similarly ototoxic provided that the cochlea becomes directly exposed.

Metabolic markers GAPDH, PKM2, ATP5B and BEC-index in advanced serous ovarian cancer.

BACKGROUND: A deregulated energy metabolism is a hallmark of malignant disease that offers possible future targets for treatment. We investigated the prognostic value of the glycolytic enzymes glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and pyruvate kinase type M2 (PKM2), mitochondrial ß-F1-ATPase (ATP5B) and the bioenergetic cellular (BEC) index in advanced ovarian cancer. METHODS: Fresh tumor samples were prospectively collected from 123 patients undergoing primary surgery for suspected advanced ovarian cancer. Of these, 57 met the eligibility criteria; stage IIC-IV, serous or endometrioid subtype, specimens containing ≥ 50% tumor cells and patients receiving platinum-based chemotherapy. An adequate amount of mRNA could be extracted in all but one case, with a resultant study population of 56 patients. Eighty-six percent of cases had serous tumors, and 93% were grade 2-3. GAPDH, PKM2 and ATP5B mRNA- and protein expression was assessed by real-time PCR and immunohistochemistry. We estimated the association with platinum-free interval (PFI) and overall survival (OS) by Cox proportional hazards models. Median follow-up was 60 months. RESULTS: High GAPDH mRNA levels (HR 2.1, 95% CI 1.0-4.5) and low BEC-index (HR 0.47, 95% CI 0.23-0.95) were both independently associated with shorter PFI. Median PFI for patients with high GAPDH mRNA was 5.0 months compared to 10.1 months for low expression cases (p = 0.031). Similarly, median PFI for patients with low BEC-index based on mRNA was 5.3 months compared to 9.8 months for high BEC-index cases (p = 0.028). CONCLUSIONS: High GAPDH or low BEC-index mRNA expression indicate early disease progression in advanced serous ovarian cancer.

HSP60 predicts survival in advanced serous ovarian cancer.

OBJECTIVE: Heat shock protein 60 (HSP60) plays an essential role in malignant cell survival. We evaluated the prognostic and treatment predictive value of HSP60 in advanced ovarian cancer. METHODS: Fresh tumor samples were prospectively collected from 123 patients undergoing primary surgery for suspected advanced ovarian cancer. Of these, 57 fulfilled the eligibility criteria, that is, International Federation of Gynecology and Obstetrics stage IIC-IV, serous/endometrioid tumors, platinum-based chemotherapy, and specimens with 50% tumor cells or greater. Heat shock protein 60 mRNA and protein expression was determined by real-time polymerase chain reaction and immunohistochemistry. We estimated the association between HSP60 and overall survival (OS) and platinum-free interval (PFI) by Cox proportional hazards models and its relationship with treatment response by Fisher's exact test. Median follow-up was 60 months. RESULTS: High HSP60 mRNA expression was associated with shorter OS (hazard ratio [HR], 3.4; 95% confidence interval [CI], 1.3-8.5) and PFI (HR, 3.3; 95% CI, 1.5-7.2). Likewise, high HSP60 protein expression was associated with shorter OS (HR, 3.2; 95% CI, 1.5-7.1) and PFI (HR, 2.6; 95% CI, 1.3-5.3). Median survival for patients with high HSP60 protein expression was 31 months compared with 55 months for low expression cases (P = 0.016). The impact on OS and PFI was even stronger in the subgroup of grade 3 serous tumors. All patients with low HSP60 levels responded to first-line chemotherapy. CONCLUSION: Heat shock protein 60 may identify groups of advanced serous ovarian cancer with different prognosis and treatment response.

Potentiation of anti-cancer treatment by modulators of energy metabolism.

Oncogene-driven proliferative signaling in tumor cells requires comprehensive upregulation of cellular energy metabolism and macromolecule syntheses. These alterations are now known to include not only upregulated glycolysis, but also increased fatty acid metabolism, glutaminolysis, deregulated mitochondrial function and more. Many prospective targets for tumor-specific pharmacological modulation of metabolism have therefore been identified. While the prospective drugs do not necessarily show very high antitumor activity by themselves, they may by depriving tumor cells of energy and building blocks for repair and proliferation come to be of major clinical use as potentiators of standard chemotherapeutic drugs and/or radiation. To this end, not only inhibitors of specific enzyme functions are being investigated, but also drugs affecting the complex signaling networks that regulate organismal and cellular energy status. This review provides examples of how modulators of energy metabolism (MEMs) targetting different aspects of tumor cell metabolism have been found to potentiate cancer treatment in vitro and in vivo.

Repeated cisplatin treatment can lead to a multiresistant tumor cell population with stem cell features and sensitivity to 3-bromopyruvate.

Cisplatin is used in treatment of several types of cancer, including epithelial ovarian carcinoma (EOC). In order to mimic clinical treatment and to investigate longterm effects of cisplatin in surviving cancer cells, two EOC cell lines were repeatedly treated with low doses. In the SKOV-3 cell line originating from malignant ascites, but not in A2780 cells from a primary tumor, this led to emergence of a stable population (SKOV-3-R) which in the absence of cisplatin showed increased motility, epithelial-mesenchymal transition (EMT) and expression of cancer stem cell markers CD117, CD44 and ALDH1. Accordingly, the cells formed self-renewing spheres in serum-free stem cell medium. Despite upregulation of mitochondrial mass and cytochrome c, and no upregulation of Bcl-2/Bcl-xL, SKOV-3-R were multiresistant to antineoplastic drugs. Cancer stem cells, or tumor-initiating cells (TICs) are highly chemoresistant and are believed to cause relapse into disseminated and resistant EOC. Our second aim was therefore to target resistance in these TIC-like cells. Resistance could be correlated with upregulation of hexokinase-II and VDAC, which are known to form a survival-promoting mitochondrial complex. The cells were thus sensitive to 3-bromopyruvate, which dissociates hexokinase-II from this complex, and were particularly sensitive to combination treatment with cisplatin at doses down to 0.1 x IC 50. 3-bromopyruvate might thus be of use in targeting the especially aggressive TIC populations.

Protein markers of cancer-associated fibroblasts and tumor-initiating cells reveal subpopulations in freshly isolated ovarian cancer ascites.

BACKGROUND: In ovarian cancer, massive intraperitoneal dissemination is due to exfoliated tumor cells in ascites. Tumor-initiating cells (TICs or cancer stem cells) and cells showing epithelial-mesenchymal-transition (EMT) are particularly implicated. Spontaneous spherical cell aggregates are sometimes observed, but although similar to those formed by TICs in vitro, their significance is unclear. METHODS: Cells freshly isolated from malignant ascites were separated into sphere samples (S-type samples, n=9) and monolayer-forming single-cell suspensions (M-type, n=18). Using western blot, these were then compared for expression of protein markers of EMT, TIC, and of cancer-associated fibroblasts (CAFs). RESULTS: S-type cells differed significantly from M-type by expressing high levels of E-cadherin and no or little vimentin, integrin-ß3 or stem cell transcription factor Oct-4A. By contrast, M-type samples were enriched for CD44, Oct-4A and for CAF markers. Independently of M- and S-type, there was a strong correlation between TIC markers Nanog and EpCAM. The CAF marker α-SMA correlated with clinical stage IV. This is the first report on CAF markers in malignant ascites and on SUMOylation of Oct-4A in ovarian cancer. CONCLUSIONS: In addition to demonstrating potentially high levels of TICs in ascites, the results suggest that the S-type population is the less tumorigenic one. Nanog(high)/EpCAM(high) samples represent a TIC subset which may be either M- or S-type, and which is separate from the CD44(high)/Oct-4A(high) subset observed only in M-type samples. This demonstrates a heterogeneity in TIC populations in vivo which has practical implications for TIC isolation based on cell sorting. The biological heterogeneity will need to be addressed in future therapeutical strategies.

3-Bromopyruvate: targets and outcomes.

The pyruvate mimetic 3-bromopyruvate (3-BP) is generally presented as an inhibitor of glycolysis and has shown remarkable efficacy in not only preventing tumor growth, but even eradicating existant tumors in animal studies. We here review reported molecular targets of 3-BP and suggest that the very range of possible targets, which pertain to the altered energy metabolism of tumor cells, contributes both to the efficacy and the tumor specificity of the drug. Its in vivo efficacy is suggested to be due to a combination of glycolytic and mitochondrial targets, as well as to secondary effects affecting the tumor microenvironment. The cytotoxicity of 3-BP is less due to pyruvate mimicry than to alkylation of, e.g., key thiols. Alkylation of DNA/RNA has not been reported. More research is warranted to better understand the pharmacokinetics of 3-BP, and its potential toxic effects to normal cells, in particular those that are highly ATP-/mitochondrion-dependent.