Diallyl disulfide enhances carbon ion beams–induced apoptotic cell death in cervical cancer cells through regulating Tap73 /ΔNp73

Abstract

Diallyl disulfide (DADS), extracted from crushed garlic by steam-distillation, has been reported to provide the anticancer activity in several cancer types. However, the effect of DADS on high-LET carbon beams -induced cell death remains unknown. Therefore, we used human cervical cancer cells to elucidate the molecular effects of this dallyl sulfide. Radiotherapy remains the mainstay of treatment, especially in advanced cervical cancer and there is still space to improve the radiosensitivity to reduce radiation dosage. In this study, we found that radiation effects evoked by high-LET carbon beam was marked by inhibition of cell viability, cell cycle arrest, significant rise of apoptotic cells, regulation of transcription factor, such as p73, as well as alterations of crucial mediator of the apoptosis pathway. We further demonstrated that pretreatment of 10 mM DADS in HeLa cells exposed to radiation resulted in decrease in cell viability and increased radiosensitivity. Additionally, cells pretreated with DADS obviously inhibited the radiationinduced G2/M phase arrest, but promoted radiation-induced apoptosis. Moreover, combination DADS and the radiation exacerbated the activation of apoptosis pathways through up-regulated ration of pro-apoptotic Tap73 to antiapoptotic DNp73, and its downstream proteins, such as FASLG, and APAF1. Taken together, these results suggest that DADS is a potential candidate as radio sensitive agent for cervical cancer.

Inhibition of SF3b1 by pladienolide B evokes cycle arrest, apoptosis induction and p73 splicing in human cervical carcinoma cells

“…Colony-forming ability was compared between untreated and treated with different concentrations of pladienolide B cell cultures as previously described [30]. The cells were seeded into 60 mm in triplicate dishes.…”

“…After incubated at 37 C for 24 h, then harvested and fixed with 70% ethanol in PBS for 30 min. The fixed cells were centrifuged at 1800 g for 5 min and washed three times with PBS, then stained with a solution containing 5 lg/ml Propidium iodide (PI, Sigma, St Louis, MO, USA) in the dark for 30 min at RT, as previously described [30]. The samples were detected with BD Accuri C6 (Becton Dickinson, San Jose, CA, USA).…”

“…Cells were treated with different concentrations pladienolide B. After incubated at 37 C for 48 h, cells were harvested and washed twice with PBS and diluted with 75 ll binding buffer, then 2.5 ll annexin V and 2.5 ll propidium iodide (Annexin V-FITC Apoptosis Detection Kit I, BD, USA) were added to 75 ll of cell suspension, as previously described [30]. After incubated in the dark for 15 min at RT, the samples were detected with BD Accuri C6 (Becton Dickinson, San Jose, CA, USA) and immediately analysed on BD Accuri C6 Plus 1.0.23.1 Installer software.…”

“…After incubated at 37 C for 48 h, cells were harvested with trypsin. Protein was extracted from the samples using RIPA lysis buffer (Solarbio, China) added PMSF, as described in our previous work [30]. The protein concentration of the lysates was measured with the Protein BCA Assay Kit (Bio-Rad, USA).…”

The Progress of Diallyl Disulfide in Anti-Cancer

“…Apoptosis pathways contain the death receptor-mediated extrinsic pathway [65], the intrinsicmitochondrial pathway [65], granzyme B-mediated pathway [66], and the endoplasmic reticulum stress-mediated pathway [67]. The protein closely associated with apoptosis mainly contains four important protein molecules involved in apoptotic pathways: caspases (the proteases which execute cell death), adapter proteins (caspase activators), Bcl-2 family proteins and inhibitors of apoptosis proteins (IAPs) [68]. In the experiment of apoptotic cell models established by pretreatment of 10 µM DADS in HeLa cells with 2Gy high-LET carbon beams, some researchers found that DADS can obviously promote the activation of apoptosis signal pathway via up-regulating the balance between Tap73…”