MilliporeSigma
  • Home
  • Search Results
  • ARHI (DIRAS3)-mediated autophagy-associated cell death enhances chemosensitivity to cisplatin in ovarian cancer cell lines and xenografts.

ARHI (DIRAS3)-mediated autophagy-associated cell death enhances chemosensitivity to cisplatin in ovarian cancer cell lines and xenografts.

Cell death & disease (2015-08-08)
M N Washington, G Suh, A F Orozco, M N Sutton, H Yang, Y Wang, W Mao, S Millward, A Ornelas, N Atkinson, W Liao, R C Bast, Z Lu
ABSTRACT

Autophagy can sustain or kill tumor cells depending upon the context. The mechanism of autophagy-associated cell death has not been well elucidated and autophagy has enhanced or inhibited sensitivity of cancer cells to cytotoxic chemotherapy in different models. ARHI (DIRAS3), an imprinted tumor suppressor gene, is downregulated in 60% of ovarian cancers. In cell culture, re-expression of ARHI induces autophagy and ovarian cancer cell death within 72 h. In xenografts, re-expression of ARHI arrests cell growth and induces autophagy, but does not kill engrafted cancer cells. When ARHI levels are reduced after 6 weeks, dormancy is broken and xenografts grow promptly. In this study, ARHI-induced ovarian cancer cell death in culture has been found to depend upon autophagy and has been linked to G1 cell-cycle arrest, enhanced reactive oxygen species (ROS) activity, RIP1/RIP3 activation and necrosis. Re-expression of ARHI enhanced the cytotoxic effect of cisplatin in cell culture, increasing caspase-3 activation and PARP cleavage by inhibiting ERK and HER2 activity and downregulating XIAP and Bcl-2. In xenografts, treatment with cisplatin significantly slowed the outgrowth of dormant autophagic cells after reduction of ARHI, but the addition of chloroquine did not further inhibit xenograft outgrowth. Taken together, we have found that autophagy-associated cancer cell death and autophagy-enhanced sensitivity to cisplatin depend upon different mechanisms and that dormant, autophagic cancer cells are still vulnerable to cisplatin-based chemotherapy.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Doxorubicin hydrochloride, 98.0-102.0% (HPLC)
Sigma-Aldrich
Chloroquine diphosphate salt, powder or crystals, 98.5-101.0% (EP)
Sigma-Aldrich
cis-Diamineplatinum(II) dichloride, ≥99.9% trace metals basis
Sigma-Aldrich
Doxorubicin hydrochloride, suitable for fluorescence, 98.0-102.0% (HPLC)
Sigma-Aldrich
Doxycycline hyclate
Sigma-Aldrich
cis-Diammineplatinum(II) dichloride, crystalline
Sigma-Aldrich
trans-Platinum(II)diammine dichloride
Sigma-Aldrich
DAPI, for nucleic acid staining
Sigma-Aldrich
N-Acetyl-L-cysteine, Sigma Grade, ≥99% (TLC), powder
Sigma-Aldrich
N-Acetyl-L-cysteine, BioXtra, ≥99% (TLC)
Sigma-Aldrich
N-Acetyl-L-cysteine, BioReagent, suitable for cell culture
Sigma-Aldrich
Fluorescein, for fluorescence, free acid