Ferroptosis, radiotherapy, and combination therapeutic strategies

Ferroptosis, an iron-dependent form of regulated cell death driven by peroxidative damages of polyunsaturated-fatty-acid-containing phospholipids in cellular membranes, has recently been revealed to play an important role in radiotherapy-induced cell death and tumor suppression, and to mediate the synergy between radiotherapy and immunotherapy. In this review, we summarize known as well as putative mechanisms underlying the crosstalk between radiotherapy and ferroptosis, discuss the interactions between ferroptosis and other forms of regulated cell death induced by radiotherapy, and explore combination therapeutic strategies targeting ferroptosis in radiotherapy and immunotherapy. This review will provide important frameworks for future investigations of ferroptosis in cancer therapy.

Thinking on controlled setting of plarebo acupuncture in clinical trial of acupuncture and moxibustion / 中国针灸

Differences and relations between effects of acupuncture therapy and sham acupuncture are systematically analyzed in this article through the influential factors of acupuncture effect. And it is held that sham acupuncture effect is not exactly equal to placebo effect. The effects of both acupuncture and sham acupuncture are composed by specific effects and non-specific effects, and the differences of non-specific effects between acupunc ture and sham acupuncture can be minimized furthest with blinding and randomized method. Therefore, the difference of acupuncture and sham acupuncture treatment rests with the degree of differences of the specific effects. Only when both of the specific effect of acupuncture and the effect of acupuncture are minimized, can it be applied as the ideal placebo control. Consequently when placebo acupunture are setted up, factors such as the body condition, site of stimulation and stimulation parameters which can influence the specific effect of acupuncture should be taken into consideration to produce the relatively minimum specific effect.

A non-infectious and quantitative cell-based bioassay for screening HIV entry inhibitors targeting HIV envelope proteins / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop an objective bioassay for quantitative detection of HIV-induced cell-cell fusion for screening HIV entry inhibitors.</p><p><b>METHODS</b>HL2/3 cells expressing HIV envelope proteins gp120/gp41, Tat, and other HIV proteins were co-cultured with HeLa-CD4-LTR-beta-gal cells expressing CD4 receptor and HIV LTR triggered reporter gene beta-galactosidase. The enzyme activities of beta-galactosidase were detected by a chromogenic substrate, chlorophenol red-beta-galactopyranoside (CPRG). Specific HIV entry inhibitors were used to validate the established detecting method.</p><p><b>RESULTS</b>No syncytium was formed by mixing HL2/3 and HeLa-CD4-LTR-beta-gal cells. However, the membrane could be fused and the Tat expressed by HL2/3 cells could bind to HIV LTR on HeLa-CD4-LTR-beta-gal cells and trigger the expression of beta-galactosidase. CPRG allowed quantitative and sensitive detection of the activity of beta-galactosidase. Further studies showed that HIV entry inhibitors could inhibit the activity of beta-galactosidase in a dose-dependent manner.</p><p><b>CONCLUSION</b>We have developed a simple, cheap, objective and quantitative non-infectious cell-cell fusion bioassay that can be used to screen for anti-HIV agents targeting the virus entry from natural and synthetic compound libraries.</p>

Study of the mechanism of caffeoyl glucopyranoses in inhibiting HIV-1 entry using pseudotyped virus system / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the inhibitory activities of caffeoyl glucopyranoses purified from Balanophora japonica Makino on HIV entry and their mechanism.</p><p><b>METHODS</b>HIV-1 Env pseudovirus was used to evaluate the anti-HIV-1 activity of those compounds. ELISA and molecular docking were used to study the mechanism of the actions of the active compounds.</p><p><b>RESULTS</b>We used the HIV-1 Env pseudovirus to test the anti-HIV-1 activity of the six phenolic compounds (final concentration 25 microg/ml), and found that only 1,2,6-Tri-O-caffeoyl-beta-D-glucopyranose (TCGP) and 1,3-Di-O-caffeoyl-4-O-galloyl-beta-D- glucopyranose (DCGGP) could effectively inhibit the entry of HIV-1 Env pseudovirus into the target cells in a dose-dependent manner, with IC(50) values of 5.5-/+0.2 and 5.3-/+0.1 microg/ml, respectively. These two compounds could also blocked the gp41 six-helix bundle formation. Molecular docking analysis suggested that they might bind to the hydrophobic cavity of the gp41 N-trimeric coiled-coil.</p><p><b>CONCLUSION</b>TCGP and DCGGP are potent HIV-1 entry inhibitors targeting gp41 and can serve as lead compounds for developing novel anti-HIV-1 microbicides for prevention of sexual HIV-1 transmission.</p>