BLOCKING PD-1/PD-L1 AXIS IS REQUIRED FOR PROLONGED RESPONSE TO TRAMETINIB IN TONGUE AND LIP CANCER MODELS IN MICE

2021 ◽  
Vol 132 (1) ◽  
pp. e16
Author(s):  
M Elkabets ◽  
M Parsad ◽  
S Jagadeeshan ◽  
D Friedmann-Morvibski ◽  
M Scaltriti
Keyword(s):  
Lip Cancer ◽  
Cancer Models ◽  
Prolonged Response

Copper-dependent ATP7B up-regulation drives the resistance of TMEM16A-overexpressing head-and-neck cancer models to platinum toxicity

2019 ◽  
Vol 476 (24) ◽  
pp. 3705-3719 ◽  
Author(s):  
Avani Vyas ◽  
Umamaheswar Duvvuri ◽  
Kirill Kiselyov
Keyword(s):  
Oxidative Stress ◽  
Head And Neck ◽  
Transcriptional Activation ◽  
Platinum Resistance ◽  
Mrna Levels ◽  
Strong Positive Correlation ◽  
Platinum Compounds ◽  
Copper Chelation ◽  
Novel Approach ◽  
Cancer Models

Platinum-containing drugs such as cisplatin and carboplatin are routinely used for the treatment of many solid tumors including squamous cell carcinoma of the head and neck (SCCHN). However, SCCHN resistance to platinum compounds is well documented. The resistance to platinum has been linked to the activity of divalent transporter ATP7B, which pumps platinum from the cytoplasm into lysosomes, decreasing its concentration in the cytoplasm. Several cancer models show increased expression of ATP7B; however, the reason for such an increase is not known. Here we show a strong positive correlation between mRNA levels of TMEM16A and ATP7B in human SCCHN tumors. TMEM16A overexpression and depletion in SCCHN cell lines caused parallel changes in the ATP7B mRNA levels. The ATP7B increase in TMEM16A-overexpressing cells was reversed by suppression of NADPH oxidase 2 (NOX2), by the antioxidant N-Acetyl-Cysteine (NAC) and by copper chelation using cuprizone and bathocuproine sulphonate (BCS). Pretreatment with either chelator significantly increased cisplatin's sensitivity, particularly in the context of TMEM16A overexpression. We propose that increased oxidative stress in TMEM16A-overexpressing cells liberates the chelated copper in the cytoplasm, leading to the transcriptional activation of ATP7B expression. This, in turn, decreases the efficacy of platinum compounds by promoting their vesicular sequestration. We think that such a new explanation of the mechanism of SCCHN tumors’ platinum resistance identifies novel approach to treating these tumors.

The truncated somatostatin receptor sst5TMD4 stimulates the production of pro-angiogenic factors in in vitro and in vivo breast cancer models

2014 ◽  
Author(s):  
Raul M Luque ◽  
Mario Duran-Prado ◽  
David Rincon-Fernandez ◽  
Marta Hergueta-Redondo ◽  
Michael D Culler ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Somatostatin Receptor ◽  
Angiogenic Factors ◽  
Cancer Models

Evaluation of Potent Isoquinoline-Based Thiosemicarbazone Antiproliferatives Against Solid Tumor Models

2019 ◽  
Author(s):  
Daniel Sun ◽  
Soumya Poddar ◽  
Roy D. Pan ◽  
Juno Van Valkenburgh ◽  
Ethan Rosser ◽  
...  
Keyword(s):  
Solid Tumor ◽  
Small Cell Lung Carcinoma ◽  
Single Agent ◽  
Resistance Mechanisms ◽  
Tumor Models ◽  
Cell Lung Carcinoma ◽  
Adaptive Resistance ◽  
Cancer Models ◽  
Nanomolar Range

The lead compound, an ⍺-N-heterocyclic carboxaldehyde thiosemicarbazone <b>HCT-13</b>, was highly potent against a panel of pancreatic, small cell lung carcinoma, and prostate cancer models, with IC<sub>90</sub> values in the low-to-mid nanomolar range.<b> </b>We show that the cytotoxicity of <b>HCT-13</b> is copper-dependent, that it acts as a copper ionophore, induces production of reactive oxygen species (ROS), and promotes mitochondrial dysfunction and S-phase arrest. Lastly, DNA damage response/replication stress response (DDR/RSR) pathways, specifically Ataxia-Telangiectasia Mutated (ATM) and Rad3-related protein kinase (ATR), were identified as actionable adaptive resistance mechanisms following <b>HCT-13 </b>treatment. Taken together, <b>HCT-13 </b>is potent against solid tumor models and warrants <i>in vivo</i> evaluation against aggressive tumor models, either as a single agent or as part of a combination therapy.

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