APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors

The alkylpyridinium polymer APS8, a potent antagonist of α7 nicotinic acetylcholine receptors (nAChRs), selectively induces apoptosis in non-small cell lung cancer cells but not in normal lung fibroblasts. To explore the potential therapeutic value of APS8 for at least certain types of lun...

Full description

Bibliographic Details
Main Authors: Sabina Berne, Maja Čemažar, Robert Frangež, Polona Juntes, Simona Kranjc, Marjana Grandič, Monika Savarin, Tom Turk
Format: Article
Language:English
Published: MDPI AG 2018-10-01
Series:Marine Drugs
Subjects:
Online Access:http://www.mdpi.com/1660-3397/16/10/367
_version_ 1811278804487766016
author Sabina Berne
Maja Čemažar
Robert Frangež
Polona Juntes
Simona Kranjc
Marjana Grandič
Monika Savarin
Tom Turk
author_facet Sabina Berne
Maja Čemažar
Robert Frangež
Polona Juntes
Simona Kranjc
Marjana Grandič
Monika Savarin
Tom Turk
author_sort Sabina Berne
collection DOAJ
description The alkylpyridinium polymer APS8, a potent antagonist of α7 nicotinic acetylcholine receptors (nAChRs), selectively induces apoptosis in non-small cell lung cancer cells but not in normal lung fibroblasts. To explore the potential therapeutic value of APS8 for at least certain types of lung cancer, we determined its systemic and organ-specific toxicity in mice, evaluated its antitumor activity against adenocarcinoma xenograft models, and examined the in-vitro mechanisms of APS8 in terms of apoptosis, cytotoxicity, and viability. We also measured Ca2+ influx into cells, and evaluated the effects of APS8 on Ca2+ uptake while siRNA silencing of the gene for α7 nAChRs, CHRNA7. APS8 was not toxic to mice up to 5 mg/kg i.v., and no significant histological changes were observed in mice that survived APS8 treatment. Repetitive intratumoral injections of APS8 (4 mg/kg) significantly delayed growth of A549 cell tumors, and generally prevented regrowth of tumors, but were less effective in reducing growth of HT29 cell tumors. APS8 impaired the viability of A549 cells in a dose-dependent manner and induced apoptosis at micro molar concentrations. Nano molar APS8 caused minor cytotoxic effects, while cell lysis occurred at APS8 >3 µM. Furthermore, Ca2+ uptake was significantly reduced in APS8-treated A549 cells. Observed differences in response to APS8 can be attributed to the number of α7 nAChRs expressed in these cells, with those with more AChRs (i.e., A549 cells) being more sensitive to nAChR antagonists like APS8. We conclude that α7 nAChR antagonists like APS8 have potential to be used as therapeutics for tumors expressing large numbers of α7 nAChRs.
first_indexed 2024-04-13T00:42:08Z
format Article
id doaj.art-749e07beda914e5fb2f9f3a274d06f6f
institution Directory Open Access Journal
issn 1660-3397
language English
last_indexed 2024-04-13T00:42:08Z
publishDate 2018-10-01
publisher MDPI AG
record_format Article
series Marine Drugs
spelling doaj.art-749e07beda914e5fb2f9f3a274d06f6f2022-12-22T03:10:07ZengMDPI AGMarine Drugs1660-33972018-10-01161036710.3390/md16100367md16100367APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic ReceptorsSabina Berne0Maja Čemažar1Robert Frangež2Polona Juntes3Simona Kranjc4Marjana Grandič5Monika Savarin6Tom Turk7Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, SloveniaDepartment of Experimental Oncology, Institute of Oncology Ljubljana, Zaloška 2, SI-1000 Ljubljana, SloveniaInstitute of of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana, SloveniaInstitute of Pathology, Wild Animals, Fish and Bees, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana, SloveniaDepartment of Experimental Oncology, Institute of Oncology Ljubljana, Zaloška 2, SI-1000 Ljubljana, SloveniaInstitute of Food Safety, Feed and Environment, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, SI-1000 Ljubljana, SloveniaDepartment of Experimental Oncology, Institute of Oncology Ljubljana, Zaloška 2, SI-1000 Ljubljana, SloveniaDepartment of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, SloveniaThe alkylpyridinium polymer APS8, a potent antagonist of α7 nicotinic acetylcholine receptors (nAChRs), selectively induces apoptosis in non-small cell lung cancer cells but not in normal lung fibroblasts. To explore the potential therapeutic value of APS8 for at least certain types of lung cancer, we determined its systemic and organ-specific toxicity in mice, evaluated its antitumor activity against adenocarcinoma xenograft models, and examined the in-vitro mechanisms of APS8 in terms of apoptosis, cytotoxicity, and viability. We also measured Ca2+ influx into cells, and evaluated the effects of APS8 on Ca2+ uptake while siRNA silencing of the gene for α7 nAChRs, CHRNA7. APS8 was not toxic to mice up to 5 mg/kg i.v., and no significant histological changes were observed in mice that survived APS8 treatment. Repetitive intratumoral injections of APS8 (4 mg/kg) significantly delayed growth of A549 cell tumors, and generally prevented regrowth of tumors, but were less effective in reducing growth of HT29 cell tumors. APS8 impaired the viability of A549 cells in a dose-dependent manner and induced apoptosis at micro molar concentrations. Nano molar APS8 caused minor cytotoxic effects, while cell lysis occurred at APS8 >3 µM. Furthermore, Ca2+ uptake was significantly reduced in APS8-treated A549 cells. Observed differences in response to APS8 can be attributed to the number of α7 nAChRs expressed in these cells, with those with more AChRs (i.e., A549 cells) being more sensitive to nAChR antagonists like APS8. We conclude that α7 nAChR antagonists like APS8 have potential to be used as therapeutics for tumors expressing large numbers of α7 nAChRs.http://www.mdpi.com/1660-3397/16/10/367lung cancerantitumor activityA549HT29CHRNA7alkylpiridiniumSCID micetoxicityapoptosis
spellingShingle Sabina Berne
Maja Čemažar
Robert Frangež
Polona Juntes
Simona Kranjc
Marjana Grandič
Monika Savarin
Tom Turk
APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors
Marine Drugs
lung cancer
antitumor activity
A549
HT29
CHRNA7
alkylpiridinium
SCID mice
toxicity
apoptosis
title APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors
title_full APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors
title_fullStr APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors
title_full_unstemmed APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors
title_short APS8 Delays Tumor Growth in Mice by Inducing Apoptosis of Lung Adenocarcinoma Cells Expressing High Number of α7 Nicotinic Receptors
title_sort aps8 delays tumor growth in mice by inducing apoptosis of lung adenocarcinoma cells expressing high number of α7 nicotinic receptors
topic lung cancer
antitumor activity
A549
HT29
CHRNA7
alkylpiridinium
SCID mice
toxicity
apoptosis
url http://www.mdpi.com/1660-3397/16/10/367
work_keys_str_mv AT sabinaberne aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT majacemazar aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT robertfrangez aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT polonajuntes aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT simonakranjc aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT marjanagrandic aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT monikasavarin aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors
AT tomturk aps8delaystumorgrowthinmicebyinducingapoptosisoflungadenocarcinomacellsexpressinghighnumberofa7nicotinicreceptors