In vitro assessment of the role of DpC in the treatment of head and neck squamous cell carcinoma

Abstract

The present study aimed to investigate the antitumor efficacy of di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) and di-2-pyridylketone-4,4,-dimethyl-3-thiosemicarbazone (Dp44mT) on head and neck squamous cell carcinoma (HNSCC) cells. The proliferation and apoptosis of HNSCC cells treated with the iron chelators DpC and Dp44mT were detected. The mechanism of DpC-induced apoptosis on HNSCC cells was investigated. The human HNSCC cell lines FaDu, Cal-27 and SCC-9 were cultured and exposed to gradient concentrations of DpC and Dp44mT. A Cell Counting Kit-8 assay was used to detect the viability of FaDu, Cal-27, SCC-9 cells. Double staining with annexin V and propidium iodide was performed for the detection of the proportion of apoptotic FaDu, Cal-27 and SCC-9 cells following treatment. The nuclear damage to Cal-27 cells that were treated with DpC was detected by Hoechst staining. Finally, western blot analysis was used to detect the expression of proteins associated with the DNA damage pathway in Cal-27 cells that were treated with DpC. The CCK-8 assay showed that treatment with DpC and Dp44mT was able to markedly inhibit the viability of FaDu, Cal-27 and SCC-9 cells in a concentration-dependent manner. In comparison to Dp44mT, treatment with DpC exhibited a more effective inhibitory effect on the viability of HNSCC cells. The proportion of apoptotic cells detected by flow cytometry increased in a dose-dependent manner in all cell lines following DpC and Dp44mT treatment, with the proportion of apoptotic HNSCC cells induced by DpC treatment being significantly higher compared with Dp44mT (P<0.05). The results of Hoechst staining revealed that the nuclei of Cal-27 cells exhibited morphological changes in response to DpC treatment, including karyopyknosis and nuclear fragmentation. The expression of DNA damage-associated proteins, including phosphorylated (p)-serine-protein kinase ATM, p-serine/threonine-protein kinase Chk1 (p-Chk-1), p-serine/threonine-protein kinase ATR (p-ATR), p-Chk-2, poly (ADP-ribose) polymerase, p-histone H2AX, breast cancer type 1 susceptibility protein, p-tumor protein P53, increased with increasing concentration of DpC in Cal-27 cells. Treatment with DpC and Dp44mT markedly inhibited cell viability and increased the apoptotic rates in human HNSCC cells in a concentration-dependent manner. DpC exhibited a stronger antitumor effect compared with Dp44mT, potentially inducing the apoptosis of HNSCC cells via the upregulation of DNA damage repair-associated proteins.

The metastasis suppressor NDRG1 down-regulates the epidermal growth factor receptor via a lysosomal mechanism by up-regulating mitogen-inducible gene 6

“…An analog of Dp44mT, namely di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) (36), also potently up-regulates NDRG1 (35). This agent possesses marked anti-tumor activity against a variety of belligerent tumors in vitro and in vivo (35,36,38,39) and has entered Phase I clinical trials for the treatment of advanced and resistant cancer (40). Of interest, agents that bind intracellular iron, such as desferrioxamine (DFO), can also up-regulate MIG6 (41), which could be mediated through an iron-responsive increase in HIF-1␣ levels, which is known to transcriptionally up-regulate MIG6 (42).…”

Unique targeting of androgen‐dependent and ‐independent AR signaling in prostate cancer to overcome androgen resistance

“…12,15,17 These agents have potent anti-cancer activity against multiple cancer types, including prostate cancer. 8,10,16,[18][19][20][21] In fact, they can inhibit multiple oncogenic signaling pathways in cancer cells due to their ability to promote the degradation of key upstream RTKs such as EGFR, HER2, HER3, and c-Met. 12,22 The mechanism of how these agents inhibit RTKs involves increased proteasomal and lysosomal degradation of these receptors.…”

“…26 Their ability to bind these metal ions plays an important role in their inhibitory effect on RTKs. 12,22 These agents demonstrate marked selectivity for cancer cells, and within their therapeutic window, do not cause toxicity, 8,10,15,16,[18][19][20] with DpC entering Phase I clinical trials. 27 In the current study, we assessed the effect of Dp44mT and DpC on AR expression and activation in PCa.…”

E6AP Promotes a Metastatic Phenotype in Prostate Cancer

“…These include di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), which has advanced to clinical trials, and the model compound di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT). These agents demonstrate potent and selective anti-tumour activity in vitro and in vivo (reviewed in Guo et al., 2016, Jansson et al., 2015; and Xu et al., 2018) Further, these agents inhibit metastasis in vivo , in a manner that depends on NDRG1 expression (Li et al., 2016, Liu et al., 2012).…”