Objectives Obesity and diabetes are well-known risk factors for the development of endometrial cancer. A high rate of aerobic glycolysis represents a key mechanism by which endometrial cancer cells consume glucose as its primary energy source. The up-regulated glycolytic pathway is a common therapeutic target whose inhibition has implications for anti-tumor activity in cancer cells. This study aimed to investigate the effect of various concentrations of glucose on cell proliferation in endometrial cancer. Methods ECC-1 and Ishikawa cells were treated with low glucose (1mM), normal glucose (5mM) and high glucose (25mM), and cytotoxicity, apoptosis, cell cycle, adhesion/invasion, and changes of AMPK/mTOR/S6 and MAPK pathways were evaluated. Results Our results revealed that high glucose increased cell growth and clonogenicity in two endometrial cancer cell lines in a dose dependent manner. Low glucose induced the activity of cleaved caspase 3 and caused cell cycle G1 arrest. High glucose increased the ability of adhesion and invasion by decreasing E-Cadherin and increasing Snail expression. In addition, high glucose increased glucose uptake and glycolytic activity through modulating the AMPK/mTOR/S6 and MAPK pathways. Conclusions Our findings suggest that glucose stimulated cell proliferation through multiple complex signaling pathways. Targeting glucose metabolism may be a promising therapeutic strategy in the treatment of endometrial cancer.

Glutamine is one of the main nutrients used by tumor cells for biosynthesis. Thus, targeted inhibition of glutamine metabolism may have anti-tumorigenic implications. In the present study, we aimed to evaluate the effects of glutamine on ovarian cancer cell growth. Three ovarian cancer cell lines, HEY, SKOV3, and IGROV-1, were assayed for glutamine dependence by analyzing cytotoxicity, cell cycle progression, apoptosis, cell stress, and glucose/glutamine metabolism. Our results revealed that administration of glutamine increased cell proliferation in all three ovarian cancer cell lines in a dose dependent manner. Depletion of glutamine induced reactive oxygen species (ROS) and expression of endoplasmic reticulum (ER) stress proteins. In addition, glutamine increased the activity of glutaminase (GLS) and glutamate dehydrogenase (GDH) by modulating the mTOR/S6 and MAPK pathways. Inhibition of mTOR activity by rapamycin or blocking S6 expression by siRNA inhibited GDH and GLS activity, leading to a decrease in glutamine-induced cell proliferation. These studies suggest that targeting glutamine metabolism may be a promising therapeutic strategy in the treatment of ovarian cancer.

Endothelial cell (EC) activation is a consistent feature of discordant xenograft rejection. Treatment of xenograft recipients with complement inhibitors and xenoreactive natural antibody depletion leads to delayed xenograft rejection associated with a cellular infiltrate comprising up to 20% natural killer (NK) cells. To determine the importance of NK cells in xenograft rejection, we studied EC activation and cytotoxicity in co-cultures containing human NK cells and porcine EC. The addition of freshly isolated NK cells to porcine EC resulted in EC cell activation, characterized by the induction of mRNA and protein for the adhesion molecule E-selectin and the chemotactic cytokine interleukin (IL)-8. The induction of E-selectin and IL-8 occurred with three separate sources of NK cells: purified CD56+ve cells, the NK cell clone B22, and the Fc receptor-deficient NK cell line NK92. Transwell cultures demonstrated that direct NK-EC contact was required for the EC induction of E-selectin and IL-8. These effects could not be inhibited with human recombinant tumor necrosis factor-alpha receptor, and the transfer of supernatants or cell lysates from activated EC to secondary cultures did not result in EC activation. The addition of human IgG enhanced the level of E-selectin expression and cellular cytotoxicity, and resulted in tumor necrosis factor-alpha and interferon-gamma secretion. Thus, human NK cells can lyse or activate EC by direct cell contact and the addition of IgG enhances EC activation and NK cell cytokine secretion. These findings implicate NK cells in EC activation and cell-mediated xenograft rejection.

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BackgroundRadiation retinopathy is a possible post-treatment complication of radiation therapy. The pathophysiologic mechanism is hypothesized to be microvascular in origin, but evidence is limited. In an effort to study retinal oxygenation in these patients, we herein evaluate the repeatability and variability of retinal oximetry measurements in subjects who had previously received radiation and make comparisons to a cohort of unirradiated subjects.MethodsUsing retinal oximetry, a non-invasive imaging modality, we performed in vivo measurements of arteriole (SaO2) and venule SO2 (SvO2) in subjects (n = 9, 18 retinas) who had received incidental radiation to their retinas (≥ 45 Gy to one retina) and in healthy subjects (n = 20, 40 retinas). A total of 1367 SO2 observations on 593 vessels in 29 persons were analyzed to assess three sources of variance in vessel SO2: 1) variance in repeated measurements of the same vessel (“repeatability”), 2) variance in different vessels within the same subject (“within-subject variability”), and 3) variance between subjects (“between-subject variability”).ResultsRetinal oximetry measurements were highly repeatable in both irradiated patients and unirradiated subjects. The within-subject variability of SvO2 and SaO2 measurements constituted the highest component of variance in both groups and was significantly higher in venules vs. arterioles (relative effect size 1.8, p<0.001) and in irradiated subjects vs. unirradiated subjects (relative effect size 1.6, p<0.001).ConclusionsRetinal oximetry is a highly repeatable technology and can be reliably used to study vascular oxygenation in irradiated subjects. Different vessels within the same subject exhibit a high degree of variability, suggesting that pooled analyses of multiple vessels are most likely to be informative of regional retinal oxygenation. Finally, irradiated subjects exhibited significantly higher within-subject variability in SO2 measurements, suggesting that radiation may cause regional alterations in retinal oxygen delivery and/or metabolism.