Pronounced transcriptional regulation of apoptotic and TNF–NF-kappa-B signaling genes during the course of thymoquinone mediated apoptosis in HeLa cells

Abstract

Thymoquinone (TQ) is the active ingredient extracted from the essential oil of Nigella sativa. A number of studies implicated TQ as an antitumor agent. In this study, cytotoxic effects of the oil of N. sativa and TQ were evaluated on human cervical cancer cell line, HeLa cells. IC50 value was ~0.125 μl/ml for N. sativa oil preparations and 12.5 μM for TQ. TQ strongly inhibited wound healing at all concentrations ranging from 12.5 to 100 μM in a scratch wound healing assay. Additionally, induction of apoptosis by TQ was assessed by Giemsa staining and TQ was found to induce apoptosis in cancer cells especially at concentrations of 50 and 100 μM. TQ-mediated transcriptional regulation of 84 genes involved in apoptosis was studied using a PCR array. At low dose (12.5 μM), TQ was found to induce expression of four pro-apoptotic genes: BIK (~22.7-fold), FASL (~2.9-fold), BCL2L10 (~2.1-fold), and CASP1 (~2-fold). TQ was also found to reduce the expression of an anti-apoptotic gene implicated in NF-kappa-B signaling and cancer: RELA (~8-fold). At high dose (100 μM), TQ mediated the expression of 21 genes implicated directly in apoptosis (6 genes), TNF signaling (10 genes), and NF-kappa-B signaling (3 genes) such as BIK, BID, TNFRSF10A, TNFRSF10B, TNF, TRAF3, RELA, and RELB. In conclusion, this study implicates the role of TQ in the inhibition of cancer cell proliferation and migration. At the same time, our results strongly suggest that TQ intervenes with TNF and NF-kappa-B signaling during TQ-mediated induction of apoptosis in cancer cells.

NQO1 overexpression is associated with poor prognosis in squamous cell carcinoma of the uterine cervix

“…In addition, studies of Yao et al showed that induction of the NQO1 gene by hypoxia and mitomycin C in human colon adenocarcinoma HT29 and human hepatoma HepG2 cells was mediated through a mechanism involving the NF-κB signaling pathway [34,35], which has been shown to play an important role in proliferation, resistance to apoptosis, invasion, and metastasis of HeLa cells [36,37]. Even in light of this recent information, the molecular mechanism of NQO1 responsible for cervical tumor progression remains to be elucidated, and additional studies are warranted to further our understanding of the role that NQO1 plays in cervical tumorigenesis.…”

Anti-cancer properties and mechanisms of action of thymoquinone, the major active ingredient ofNigella sativa

“…36 and its receptors were significantly suppressed by TQ in hepatocellular carcinoma cells in a timeand dose-dependent manner . Using a PCR array and a human cervical cancer cell line (HeLa), Sakalar and colleagues have recently assessed TQ-mediated transcriptional regulation of 84 genes that are known to play critical roles in apoptosis (Sakalar et al, 2013). TQ treatment (12.5-dependent manner (Sakalar et al, 2013) pro-apoptotic genes (BIK, FASL, Bcl-2L10, and CASP1) while potently suppressing the expression of RelA, an anti-apoptotic factor implicated in NF-Q induced the expression of 21 genes whose products are directly involved in apoptosis, TNF signaling, and NF-TRAF3, RelA, and RelB (Sakalar et al, 2013).…”

Therapeutic Implications of Black Seed and Its Constituent Thymoquinone in the Prevention of Cancer through Inactivation and Activation of Molecular Pathways

“…TQ inhibits NF- κ B activation with resultant downregulation of multiple inflammatory genes. A recent study reported that TQ intervenes with TNF and NF-kappa-B signaling during TQ-mediated induction of apoptosis in cancer cells [32]. TQ finally acts as multiple target modulator in the cancer control via modulation of genetic pathways (Figure 3).…”

“…The activation of NF- κ B has been noticed in various tumors [102–104]. A recent study reported that TQ intervenes in NF-kappa-B signaling during TQ-mediated induction of apoptosis in cancer cells [32]. Another report showed that TQ has strong anti-inflammatory activity in several PDA cell lines and demonstrates that TQ mediates its effects by reducing the activity and transcription of NF- κ B [105].…”