Artificial cavernosa-like tissue based on multibubble Matrigel and a human corpus cavernous fibroblast scaffold.

Ex vivo tissue culture of the human corpus cavernosum (CC) can be used to explore the tissue structural changes and complex signaling networks. At present, artificial CC-like tissues based on acellular or three-dimensional (3D)-printed scaffolds are used to solve the scarcity of primary penis tissue samples. However, inconvenience and high costs limit the wide application of such methods. Here, we describe a simple, fast, and economical method of constructing artificial CC-like tissue. Human CC fibroblasts (FBs), endothelial cells (ECs), and smooth muscle cells (SMCs) were expanded in vitro and mixed with Matrigel in specific proportions. A large number of bubbles were formed in the mixture by vortexing combined with pipette blowing, creating a porous, spongy, and spatial structure. The CC FBs produced a variety of signaling factors, showed multidirectional differentiation potential, and grew in a 3D grid in Matrigel, which is necessary for CC-like tissue to maintain a porous structure as a cell scaffold. Within the CC-like tissue, ECs covered the surface of the lumen, and SMCs were located inside the trabeculae, similar to the structure of the primary CC. Various cell components remained stable for 3 days in vitro, but the EC content decreased on the 7th day. Wingless/integrated (WNT) signaling activation led to lumen atrophy and increased tissue fibrosis in CC-like tissue, inducing the same changes in characteristics as in the primary CC. This study describes a preparation method for human artificial CC-like tissue that may provide an improved experimental platform for exploring the function and structure of the CC and conducting drug screening for erectile dysfunction therapy.

Clinical features and microsurgical reconstruction of congenital unilateral absence of the vas deferens with obstructive azoospermia: a tertiary care center experience.

Patients with congenital unilateral absence of the vas deferens (CUAVD) manifest diverse symptoms from normospermia to azoospermia. Treatment for CUAVD patients with obstructive azoospermia (OA) is complicated, and there is a lack of relevant reports. In this study, we describe the clinical features and evaluate the treatments and outcomes of CUAVD patients with OA. From December 2015 to December 2020, 33 patients were diagnosed as CUAVD with OA in Shanghai General Hospital (Shanghai, China). Patient information, ultrasound findings, semen analysis, hormone profiles, and treatment information were collected, and the clinical outcomes were evaluated. Of 33 patients, 29 patients were retrospectively analyzed. Vasoepididymostomy (VE) or cross VE was performed in 12 patients, the patency rate was 41.7% (5/12), and natural pregnancy was achieved in one of the patients. The other 17 patients underwent testicular sperm extraction as the distal vas deferens (contralateral side) was obstructed. These findings showed that VE or cross VE remains an alternative treatment for CUAVD patients with OA, even with a relatively low rate of patency and natural pregnancy.

Initiating antiretroviral therapy within 2 weeks of anti-Pneumocystis treatment does not increase mortality or AIDS-defining events in patients with HIV-associated moderate to severe Pneumocystis pneumonia: results of a prospective observational multicenter study.

BACKGROUND: The mortality rate remains high among patients with coinfection with Pneumocystis pneumonia (PCP) and HIV. The timing for initiation of antiretroviral therapy (ART) after a diagnosis of moderate to severe PCP remains controversial, however. We therefore designed the present study to determine the optimal timing for ART initiation in AIDS-associated PCP (AIDS/PCP) patients. METHODS: This was a multicenter, observational, prospective clinical trial. Eligible participants were recruited from 14 hospitals in mainland China, and assigned to an Early ART arm (initiation of ART ≤ 14 days after PCP diagnosis) and a Deferred ART arm (initiation of ART > 14 days after PCP diagnosis). The primary outcomes were death and the incidence of AIDS-defining events at week 48. The secondary outcomes were the changes in CD4+ T-cell counts from baseline values at weeks 12, 24, and 48, the virological suppression rate at week 24 and week 48, the rate of development of PCP-associated immune reconstitution inflammatory syndrome (PCP/IRIS), and the rate of adverse events over 48 weeks. RESULTS: The present study was performed using the data of 363 participants, with 169 participants in the Early ART arm, and 194 participants in the Deferred ART arm. Immunological and virological outcomes were found to be similar in both treatment arms. At week 48, there were no significant differences for the incidence of mortality (20 vs. 26, p = 0.860), and AIDS-defining events (17 vs. 26, p = 0.412). Over 48 weeks, the rates of PCP/IRIS (2 vs. 3, p = 1.000), adverse events (70 vs. 72, p = 0.465), and grade 3 or 4 adverse events (28 vs. 34, p = 0.919) did not reach statistical significance. A significant difference observed between two study arms was that 11 participants (55.0%) in the Early ART arm compared to 23 participants (88.5%) in the Deferred ART arm (p = 0.026) succumbed before ART had ever been started. CONCLUSIONS: Early ART initiation results in no increase in mortality, AIDS-defining events, IRIS, adverse events, and immunological or virological outcomes. These results support the early initiation of ART in patients with moderate to severe AIDS/PCP. Clinical trial registration The present trial was registered at Chinese Clinical Trial Registry (ChiCTR1900021195). Registered 1 February 2019, http://www.chictr.org.cn/showproj.aspx?proj=35362 .

Effectiveness of adjunctive corticosteroid therapy in patients with severe COVID-19: A retrospective cohort study.

BACKGROUND: The effectiveness of adjunctive corticosteroid use in patients with coronavirus disease 2019 (COVID-19) remains inconclusive. AIM: To investigate the effectiveness of adjunctive corticosteroid therapy in patients with severe COVID-19. METHODS: We conducted a retrospective analysis of the difference in several outcomes between patients with severe COVID-19 who received corticosteroid therapy (the corticosteroid group) and patients with severe COVID-19 who did not receive corticosteroid therapy (the non-corticosteroid group). RESULTS: Seventy-five patients were included in this study. Of these, 47 patients were in the corticosteroid group and 28 patients were in the non-corticosteroid group. There were no differences between the two groups in the total length of hospital stay, the length of intensive care unit stay, high-flow oxygen days, non-invasive ventilator days, invasive ventilation days, and mortality rate. Total lesion volume ratio, consolidation volume ratio and ground-glass opacity volume ratio in the corticosteroid group decreased significantly on day 14, while those in the non-corticosteroid group did not show a significant decrease. CONCLUSION: Our results show that adjunctive corticosteroid use did not significantly improve clinical outcomes in severe COVID-19 patients, but might promote the absorption of pulmonary lesions. Larger multicenter randomized controlled studies may be needed to confirm this.

Predictive factors of progression to severe COVID-19.

AIM: Early diagnosis and treatment are crucial for the survival of severe Coronavirus Disease 2019 (COVID-19) patients, but data with regard to risk factors for disease progression from milder COVID-19 to severe COVID-19 remain scarce. METHODS: We conducted a retrospective analysis on 116 patients. RESULTS: Three factors were observed to be independently associated with progression to severe COVID-19 during 14 days after admission: (a) age 65 years or older (hazard ratio [HR] = 8.456; 95% CI: 2.706-26.426); (b) creatine kinase (CK) ≥ 180 U/L (HR = 3.667; 95% CI: 1.253-10.733); and (c) CD4+ T-cell counts <300 cells/µL (HR = 4.695; 95% CI: 1.483-14.856). The difference in rates of severe COVID-19 development was found to be statistically significant between patients aged 65 years or older (46.2%) and those younger than 65 years (90.2%), between patients with CK ≥ 180 U/L (55.6%) and those with CK < 180 U/L (91.5%), and between patients with CD4+ T-cell counts <300 cells/µL (53.8%) and those with CD4+ cell counts ≥300 cells/µL (83.2%). CONCLUSIONS: Age ≥ 65 years, CK ≥ 180 U/L, and CD4+ T-cell counts <300 cells/µL at admission were risk factors independently associated with disease progression to severe COVID-19 during 14 days after admission and are therefore potential markers for disease progression in patients with milder COVID-19.

Enhanced carbon dioxide conversion at ambient conditions via a pore enrichment effect.

Chemical fixation of carbon dioxide (CO2) may be a pathway to retard the current trend of rapid global warming. However, the current economic cost of chemical fixation remains high because the chemical fixation of CO2 usually requires high temperature or high pressure. The rational design of an efficient catalyst that works at ambient conditions might substantially reduce the economic cost of fixation. Here, we report the rational design of covalent organic frameworks (COFs) as efficient CO2 fixation catalysts under ambient conditions based on the finding of "pore enrichment", which is concluded by a detailed investigation of the 10994 COFs. The best predicted COF, Zn-Salen-COF-SDU113, is synthesized, and its efficient catalytic performance for CO2 cycloaddition to terminal epoxide is confirmed with a yield of 98.2% and turnover number (TON) of 3068.9 under ambient conditions, which is comparable to the reported leading catalysts. Moreover, this COF achieves the cycloaddition of CO2 to 2,3-epoxybutane under ambient conditions among all porous materials. This work provides a strategy for designing porous catalysts in the economic fixation of carbon dioxide.

Exploiting Cancer's Tactics to Make Cancer a Manageable Chronic Disease.

The history of modern oncology started around eighty years ago with the introduction of cytotoxic agents such as nitrogen mustard into the clinic, followed by multi-agent chemotherapy protocols. Early success in radiation therapy in Hodgkin lymphoma gave birth to the introduction of radiation therapy into different cancer treatment protocols. Along with better understanding of cancer biology, we developed drugs targeting cancer-related cellular and genetic aberrancies. Discovery of the crucial role of vasculature in maintenance, survival, and growth of a tumor opened the way to the development of anti-angiogenic agents. A better understanding of T-cell regulatory pathways advanced immunotherapy. Awareness of stem-like cancer cells and their role in cancer metastasis and local recurrence led to the development of drugs targeting them. At the same time, sequential and rapidly accelerating advances in imaging and surgical technology have markedly increased our ability to safely remove ≥90% of tumor cells. While we have advanced our ability to kill cells from multiple directions, we have still failed to stop most types of cancer from recurring. Here we analyze the tactics employed in cancer evolution; namely, chromosomal instability (CIN), intra-tumoral heterogeneity (ITH), and cancer-specific metabolism. These tactics govern the resistance to current cancer therapeutics. It is time to focus on maximally delaying the time to recurrence, with drugs that target these fundamental tactics of cancer evolution. Understanding the control of CIN and the optimal state of ITH as the most important tactics in cancer evolution could facilitate the development of improved cancer therapeutic strategies designed to transform cancer into a manageable chronic disease.

Effectiveness of glucocorticoid therapy in patients with severe coronavirus disease 2019: protocol of a randomized controlled trial.

BACKGROUND: At the end of 2019, a novel coronavirus outbreak causative organism has been subsequently designated the 2019 novel coronavirus (2019-nCoV). The effectiveness of adjunctive glucocorticoid therapy in the management of 2019-nCoV-infected patients with severe lower respiratory tract infections is not clear, and warrants further investigation. METHODS: The present study will be conducted as an open-labeled, randomized, controlled trial. We will enrol 48 subjects from Chongqing Public Health Medical Center. Each eligible subject will be assigned to an intervention group (methylprednisolone via intravenous injection at a dose of 1-2 mg/kg/day for 3 days) or a control group (no glucocorticoid use) randomly, at a 1:1 ratio. Subjects in both groups will be invited for 28 days of follow-up which will be scheduled at four consecutive visit points. We will use the clinical improvement rate as our primary endpoint. Secondary endpoints include the timing of clinical improvement after intervention, duration of mechanical ventilation, duration of hospitalization, overall incidence of adverse events, as well as rate of adverse events at each visit, and mortality at 2 and 4 weeks. DISCUSSION: The present coronavirus outbreak is the third serious global coronavirus outbreak in the past two decades. Oral and parenteral glucocorticoids have been used in the management of severe respiratory symptoms in coronavirus-infected patients in the past. However, there remains no definitive evidence in the literature for or against the utilization of systemic glucocorticoids in seriously ill patients with coronavirus-related severe respiratory disease, or indeed in other types of severe respiratory disease. In this study, we hope to discover evidence either supporting or opposing the systemic therapeutic administration of glucocorticoids in patients with severe coronavirus disease 2019. TRIAL REGISTRATION: ClinicalTrials.gov, ChiCTR2000029386, http://www.chictr.org.cn/showproj.aspx?proj=48777.

Dual antivascular function of human fibulin-3 variant, a potential new drug discovery strategy for glioblastoma.

The ECM protein EFEMP1 (fibulin-3) is associated with all types of solid tumor through its cell context-dependent dual function. A variant of fibulin-3 was engineered by truncation and mutation to alleviate its oncogenic function, specifically the proinvasive role in glioblastoma multiforme (GBM) cells at stem-like state. ZR30 is an in vitro synthesized 39-kDa protein of human fibulin-3 variant. It has a therapeutic effect in intracranial xenograft models of human GBM, through suppression of epidermal growth factor receptor/AKT and NOTCH1/AKT signaling in GBM cells and extracellular MMP2 activation. Glioblastoma multiforme is highly vascular, with leaky blood vessels formed by tumor cells expressing endothelial cell markers, including CD31. Here we studied GBM intracranial xenografts, 2 weeks after intratumoral injection of ZR30 or PBS, by CD31 immunohistochemistry. We found a 70% reduction of blood vessel density in ZR30-treated xenografts compared with that of PBS-treated ones. Matrigel plug assays showed the effect of ZR30 on suppressing angiogenesis. We further studied the effect of ZR30 on genes involved in endothelial transdifferentiation (ETD), in 7 primary cultures derived from 3 GBMs under different culture conditions. Two GBM cultures formed mesh structures with upregulation of ETD genes shortly after culture in Matrigel Matrix, and ZR30 suppressed both. ZR30 also downregulated ETD genes in two GBM cultures with high expression of these genes. In conclusion, multifaceted tumor suppression effects of human fibulin-3 variant include both suppression of angiogenesis and vasculogenic mimicry in GBM.

Tracking Functional Tumor Cell Subpopulations of Malignant Glioma by Phasor Fluorescence Lifetime Imaging Microscopy of NADH.

Intra-tumoral heterogeneity is associated with therapeutic resistance of cancer and there exists a need to non-invasively identify functional tumor subpopulations responsible for tumor recurrence. Reduced nicotinamide adenine dinucleotide (NADH) is a metabolic coenzyme essential in cellular respiration. Fluorescence lifetime imaging microscopy (FLIM) of NADH has been demonstrated to be a powerful label-free indicator for inferring metabolic states of living cells. Using FLIM, we identified a significant shift towards longer NADH fluorescence lifetimes, suggesting an increase in the fraction of protein-bound NADH, in the invasive stem-like tumor-initiating cell (STIC) subpopulation relative to the tumor mass-forming cell (TMC) subpopulation of malignant gliomas. By applying our previously studied model to transition glioma from a majority of STIC to a majority of TMC in serum-adherent culture conditions following serial passages, we compared changes in NADH states, cellular respirations (oxidative phosphorylation and glycolysis), EGFR expression, and cell-growth speed over passages. We identified a significant positive correlation between free-NADH fraction and cell growth, which was related to an increase of TMC fraction. In comparison, the increase of EGFR and cellular respirations preceded all these changes. In conclusion, FLIM of NADH provides a non-invasive method to monitor the dynamics of tumor heterogeneity before and after treatment.

The role of EGFR double minutes in modulating the response of malignant gliomas to radiotherapy.

EGFR amplification in cells having double minute chromosomes (DM) is commonly found in glioblastoma multiforme (GBM); however, how much it contributes to the current failure to treat GBM successfully is unknown. We studied two syngeneic primary cultures derived from a GBM with and without cells carrying DM, for their differential molecular and metabolic profiles, in vivo growth patterns, and responses to irradiation (IR). Each cell line has a distinct molecular profile consistent with an invasive "go" (with DM) or angiogenic "grow" phenotype (without DM) demonstrated in vitro and in intracranial xenograft models. Cells with DM were relatively radio-resistant and used higher glycolytic respiration and lower oxidative phosphorylation in comparison to cells without them. The DM-containing cell was able to restore tumor heterogeneity by mis-segregation of the DM-chromosomes, giving rise to cell subpopulations without them. As a response to IR, DM-containing cells switched their respiration from glycolic metabolism to oxidative phosphorylation and shifted molecular profiles towards that of cells without DM. Irradiated cells with DM showed the capacity to alter their extracellular microenvironment to not only promote invasiveness of the surrounding cells, regardless of DM status, but also to create a pro-angiogenic tumor microenvironment. IR of cells without DM was found primarily to increase extracellular MMP2 activity. Overall, our data suggest that the DM-containing cells of GBM are responsible for tumor recurrence due to their high invasiveness and radio-resistance and the mis-segregation of their DM chromosomes, to give rise to fast-growing cells lacking DM chromosomes.

Effects of temperature and fatigue on the metabolism and swimming capacity of juvenile Chinese sturgeon (Acipenser sinensis).

Chinese sturgeon (Acipenser sinensis) is a critically endangered species. A flume-type respirometer, with video, was used to conduct two consecutive stepped velocity tests at 10, 15, 20, and 25 °C. Extent of recovery was measured after the 60-min recovery period between trials, and the recovery ratio for critical swimming speed (U crit) averaged 91.88% across temperatures. Temperature (T) effects were determined by comparing U crit, oxygen consumption rate (MO 2), and tail beat frequency (TBF) for each temperature. Results from the two trials were compared to determine the effect of exercise. The U crit occurring at 15 °C in both trials was significantly higher than that at 10 and 25 °C (p < 0.05). The U crit was plotted as a function of T and curve-fitting allowed calculation of the optimal swimming temperature 3.28 BL/s at 15.96 °C (trial 1) and 2.98 BL/s at 15.85 °C (trial 2). In trial 1, MO 2 increased rapidly with U, but then declined sharply as swimming speed approached U crit. In trial 2, MO 2 increased more slowly, but continuously, to U crit. TBF was directly proportional to U and the slope (dTBF/dU) for trial 2 was significantly lower than that for trial 1. The inverse slope (tail beats per body length, TB/BL) is a measure of swimming efficiency and the significant difference in slopes implies that the exercise training provided by trial 1 led to a significant increase in swimming efficiency in trial 2.

Human fibulin-3 protein variant expresses anti-cancer effects in the malignant glioma extracellular compartment in intracranial xenograft models.

BACKGROUND: Decades of cytotoxic and more recently immunotherapy treatments for malignant glioma have had limited success due to dynamic intra-tumoral heterogeneity. The dynamic interplay of cancer cell subpopulations has been found to be under the control of proteins in the cancer microenvironment. EGF-containing fibulin-like extracellular matrix protein (EFEMP1) (also fibulin-3) has the multiple functions of suppressing cancer growth and angiogenesis, while promoting cancer cell invasion. EFEMP1-derived tumor suppressor protein (ETSP) retains EFEMP1's anti-growth and anti-angiogenic functions while actually inhibiting cancer cell invasion. METHODS: In this study, we examined the therapeutic effect on glioblastoma multiforme (GBM) of an in vitro synthesized protein, ZR30, which is based on the sequence of ETSP, excluding the signaling peptide. RESULTS: ZR30 showed the same effects as ETSP in blocking EGFR/NOTCH/AKT signaling pathways, when applied to cultures of multiple GBM cell lines and primary cultures. ZR30's inhibition of MMP2 activation was shown not only for GBM cells, but also for other types of cancer cells having overexpression of MMP2. A significant improvement in survival of mice with orthotopic human GBM xenografts was observed after a single, intra-tumoral injection of ZR30. Using a model mimicking the intra-tumoral heterogeneity of GBM with cell subpopulations carrying different invasive and proliferative phenotypes, we demonstrated an equal and simultaneous tumor suppressive effect of ZR30 on both tumor cell subpopulations, with suppression of FOXM1 and activation of SEMA3B expressions in the xenografts. CONCLUSION: Overall, the data support a complementary pleiotrophic therapeutic effect of ZR30 acting in the extracellular compartment of GBM.

Weaponizing human EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) for 21st century cancer therapeutics.

De-regulated EFEMP1 gene expression in solid tumors has been widely reported with conflicting roles. We dissected EFEMP1 to identify domains responsible for its cell context-dependent dual functions, with the goal being to construct an EFEMP1-derived tumor-suppressor protein (ETSP) that lacked tumor-promoting function. Exon/intron boundaries of EFEMP1 were used as boundaries of functional modules in constructing EFEMP1 variants, with removal of various module(s), and/or mutating an amino acid residue to convert a weak integrin binding-site into a strong one. A series of in vitro assays on cancerous features, and subcutaneous and intracranial xenograft-formation assays, were carried out for effects from overexpression of wild-type and variant forms of EFEMP1 in two glioma subpopulations characterized as tumor mass-forming cells (TMCs) or stem-like tumor initiating cells (STICs), where EFEMP1 showed cellcontext- dependent dual functions. One of the EFEMP1 variants was identified as the sought-after ETSP, which had a stronger tumor-suppression function in TMCs by targeting EGFR and angiogenesis, and a new tumor-suppression function in STICs by targeting NOTCH signaling and MMP2-mediated cell invasion. Therefore, ETSP may form the basis for further important research to develop a novel cancer therapy to treat many types of cancer by its tumor suppressor effect in the extracellular matrix compartment.

Irradiation of primary human gliomas triggers dynamic and aggressive survival responses involving microvesicle signaling.

Malignant gliomas are heterogeneous populations of dynamically interacting cells. Genomic and transcriptional changes define this cellular hierarchy and allow certain tumor cells to co-opt metabolic machinery and adopt gene expression profiles that promote cellular reprogramming. Resultant expansion of privileged subpopulations can then rapidly adapt to microenvironmental stress that ultimately influence tumor response to therapeutic intervention. In this study, primary gliomas were subjected to acute or chronic irradiation and analyzed for changes in survival parameters, oxidative stress, gene expression, and cell invasion before and after treatment with secreted microvesicles isolated from irradiated and nonirradiated glioma cells. We found that primary gliomas exposed to ionizing radiation undergo metabolic changes that increase oxidative stress, alter gene expression, and affect the contents of and response to cellular secreted microvesicles. Radiation-induced changes were exacerbated under chronic as compared to acute irradiation paradigms and promoted cellular reprogramming through enhanced expression of key transcription factors and regulators involved in differentiation and pluripotency (SOX2, POU3F2, SALL2, OLIG2, NANOG, POU5F1v1, MSI1). Irradiation also affected changes in paracrine signaling mediated by cellular secreted microvesicles that significantly altered target cell phenotype. Primary gliomas treated with microvesicles exhibited increased radioresistance and treatment with microvesicles from chronically irradiated gliomas promoted invasion via induction of increased matrix metalloproteinase II activity. Together, our data describe a complex radiation response of primary glioma cells involving metabolic and transcriptional changes that alter radiation sensitivity and induce invasive behavior. These important changes can contribute to tumor growth and recurrence, and confound interventions designed to forestall disease progression. Environ. Mol. Mutagen. 57:405-415, 2016. © 2015 Wiley Periodicals, Inc.

Cell context-dependent dual effects of EFEMP1 stabilizes subpopulation equilibrium in responding to changes of in vivo growth environment.

Conflicting functions of EFEMP1 in cancer have been reported. Using two syngeneic glioma cell lines (U251 and U251-NS) carrying two different principal cell subpopulations that express high or low EGFR, and that are able to interconvert via mis-segregation of chromosome 7 (Chr7), we studied EFEMP1's cell-context-dependent functions in regulating subpopulation equilibrium, here defined by the percentage of cells carrying different copies of Chr7. We found that EFEMP1 attenuated levels of EGFR and cellular respiration in high-EGFR-expressing cells, but increased levels of NOTCH1, MMP2, cell invasiveness, and both oxidative phosphorylation and glycolytic respiration in low-EGFR-expressing cells. Consistently, EFEMP1 suppressed intracranial xenograft formation in U251 and promoted its formation in U251-NS. Interestingly, subpopulation equilibria in xenografts of U251-NS without EFEMP1 overexpression were responsive to inoculum size (1, 10 and 100 thousand cells), which may change the tumor-onset environment. It was not observed in xenografts of U251-NS with EFEMP1 overexpression. The anti-EGFR function of EFEMP1 suppressed acceleration of growth of U251-NS, but not the subpopulation equilibrium, when serially passed under a different (serum-containing adherent) culture condition. Overall, the data suggest that the orthotopic environment of the brain tumor supports EFEMP1 in carrying out both its anti-EGFR and pro-invasive/cancer stem cell-transforming functions in the two glioma cell subpopulations during formation of a single tumor, where EFEMP1 stabilizes the subpopulation equilibrium in response to alterations of the growth environment. This finding implies that EFEMP1 may restrain cancer plasticity in coping with ever-changing tumor microenvironments and/or therapeutic-intervention stresses.

Chronic inflammation: is it the driver or is it paving the road for malignant transformation?

Chronic inflammation in well-defined mouse models such as Giα2 knock out mouse has been shown to trigger formation and expansion of hypoxic niches and also leads to up regulation of NFĸB, offering cells which have adapted their genetic machinery to hypoxia a unique survival advantage. These adapted cells have been shown to acquire stem cell-like capabilities as shown by up regulation of stem cell markers. Such long lived cells become permanent residents in sub mucosa and acquire a malignant phenotype from long-term exposure to noxious environmental agents due to a barrier defect secondary to down regulation of barrier proteins such as Zo1 and Occludin. Indeed mitotic spindle disorientation in such mice has been proposed as another contributory factor to malignant transformation. Sterilization of bowel lumen of these mice through different techniques has prevented malignant transformation in the presence of chronic inflammation. These facts stand strongly against chronic inflammation as a true driver of carcinogenesis but clearly support its role in facilitating the emergence of the neoplastic clone.

Linking differential radiation responses to glioma heterogeneity.

The phenotypic and genetic diversity that define tumor subpopulations within high-grade glioma can lead to therapeutic resistance and tumor recurrence. Given that cranial irradiation is a frontline treatment for malignant glioma, understanding how irradiation selectively effects different cellular subpopulations within these heterogeneous cancers should help identify interventions targeted to better combat this deadly disease. To analyze the radiation response of distinct glioma subpopulations, 2 glioma cells lines (U251, A172) were cultured under conditions that promoted either adherence or non-adherent spheroids. Past work has demonstrated that subpopulations derived from defined culture conditions exhibit differences in karyotype, proliferation, gene expression and tumorigenicity. Spheroid cultures from each of the glioma cell lines were found to be more radiosensitive, which was consistent with higher levels of oxidative stress and lower levels of both oxidative phosphorylation and glycolytic metabolism 1 week following irradiation. In contrast, radioresistant non-spheroid parental cultures showed increased glycolytic activity in response to irradiation, while oxidative phosphorylation was affected to a lesser extent. Overall these data suggest that prolonged radiation-induced oxidative stress can compromise the metabolic state of certain glioma subpopulations thereby altering their sensitivity to an important therapeutic intervention used routinely for the control of glioma.

Anti-EGFR function of EFEMP1 in glioma cells and patient prognosis.

EGFR is one of the key oncogenes subjected to targeted therapy for several cancers, as it is known to be amplified and/or mutated in up to 40% of malignant gliomas. EFEMP1, a fibulin-like extracellular protein, exerts both tumor suppressive and oncogenic effects in various cancers and glioma cell models. Although EFEMP1's anti-cancer activity has most commonly been attributed to its anti-angiogenic effects, we showed for gliomas that EFEMP1's binding to EGFR accounts for its suppression of the intracranial tumorigenicity of glioma cells expressing high levels of EGFR. In gliomas where EFEMP1 expression, and thus the anti-EGFR effect of EFEMP1, was suppressed, heightened levels of EGFR expression were associated with unfavorable patient outcomes in prognostic models. Results from the current study clearly demonstrate the impact that the anti-EGFR function of EFEMP1 has on the expression of EGFR and patient prognosis. A glioma prognostic model also suggests EFEMP1's context-dependent oncogenic function in gliomas expressing low levels of EGFR. Hence the level of EFEMP1 expression may have a predictive value for choosing patients for anti-EGFR therapy.

Tumor-specific chromosome mis-segregation controls cancer plasticity by maintaining tumor heterogeneity.

Aneuploidy with chromosome instability is a cancer hallmark. We studied chromosome 7 (Chr7) copy number variation (CNV) in gliomas and in primary cultures derived from them. We found tumor heterogeneity with cells having Chr7-CNV commonly occurs in gliomas, with a higher percentage of cells in high-grade gliomas carrying more than 2 copies of Chr7, as compared to low-grade gliomas. Interestingly, all Chr7-aneuploid cell types in the parental culture of established glioma cell lines reappeared in single-cell-derived subcultures. We then characterized the biology of three syngeneic glioma cultures dominated by different Chr7-aneuploid cell types. We found phenotypic divergence for cells following Chr7 mis-segregation, which benefited overall tumor growth in vitro and in vivo. Mathematical modeling suggested the involvement of chromosome instability and interactions among cell subpopulations in restoring the optimal equilibrium of tumor cell types. Both our experimental data and mathematical modeling demonstrated that the complexity of tumor heterogeneity could be enhanced by the existence of chromosomes with structural abnormality, in addition to their mis-segregations. Overall, our findings show, for the first time, the involvement of chromosome instability in maintaining tumor heterogeneity, which underlies the enhanced growth, persistence and treatment resistance of cancers.