The relationship between energy status and AMP-activated protein kinase in human H460 lung cancer cells.

In cultured cells, glucose and serum provide constant sources of energy and growth factors, both of which are important for cell survival and proliferation. AMP-activated protein kinase (AMPK) plays a key role in sensing intracellular ATP levels and acts as a critical regulator of energy homeostasis. To investigate the relationship between energy status and AMPK activity in lung cancer, H460 cells were starved in either glucose-free or serum-free medium and then re-stimulated with glucose and serum, respectively. The levels of ATP and lactate and the activities of AMPK and lactate dehydrogenase (LDH) were analyzed at different time intervals. During glucose treatment, the activity of AMPK was induced by glucose and showed biphasic reaction kinetics. The ATP level was gradually increased up to 2-fold compared with that in serum treatment after 24 h and lactate level was decreased to approximately 60%. The LDH activity slightly increased and reached a peak after 6 h. During serum treatment, the activity of AMPK was suppressed and the ATP level showed a dramatic 30% increase after 1 h. In contrast, the lactate level was gradually increased and then reverted to the background level after 24 h. The activity of LDH was slightly decreased after 12 h and eventually returned to the background level. This study showed the alteration of energy status in lung cancer cells in response to altered levels of glucose and serum. We suggest that the activation of AMPK and inhibition of glycolysis might be exploited as therapeutic tactics in cancer treatment.

Comparability of bovine virus titers obtained by TCID50/ml and FAID50/ml.

In this study, the correlation or comparability was assessed in the values of virus titers measured by either infectivity assay [reported as 50% tissue culture infectious doses (TCID(50)/ml)] or by immunofluorescence assay [reported as 50% fluorescent antibody infectious dose (FAID(50)/ml)]. The results demonstrate that bovine virus titers measured in infected bovine turbinate cells by these two methods are comparable. Clear demonstration of the comparability of these two methods provides a choice of a method for measuring the titer of bovine viruses.

The Anti-hepatitis B Virus Activity of Boehmeria nivea Extract in HBV-viremia SCID Mice.

Boehmeria nivea extract (BNE) is widely used in southern Taiwan as a folk medicine for hepato-protection and hepatitis treatment. In previous studies, we demonstrated that BNE could reduce the supernatant hepatitis B virus (HBV) DNA in HBV-producing HepG2 2.2.15 cells. In the present study, we established an animal model of HBV viremia and used it to validate the efficacy of BNE in vivo. In this animal model, serum HBV DNA and HBsAg were elevated in accordance with tumor growth. To evaluate the anti-HBV activity of BNE, HBV-viremia mice were built up after one subcutaneous inoculation of HepG2 2.2.15 tumor cells in severe combined immunodeficiency mice over 13 days. The levels of serum HBV DNA were elevated around 10(5)-10(6) copies per milliliter. Both oral and intraperitoneal administration of BNE were effective at inhibiting the production of HBsAg and HBV DNA, whereas tumor growth was not affected by all test articles. Intraperitoneal administration of BNE appeared to have greater potential to inhibit serum HBV DNA levels compared with oral administration under the same dosage. Notably, reduced natural killer cell activity was also observed after high dosage of BNE administration, and this correlated with reduced serum HBV DNA. In conclusion, BNE exhibited potential anti-HBV activity in an animal model of HBV viremia.