This preprint is under consideration at BMC Cancer. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research Article
Mitochondrial DNA abnormalities provide mechanistic insight and predict reactive oxygen species-stimulating drug efficacy
Qian An
University of Portsmouth
Corresponding Author
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background Associations between mitochondrial genetic abnormalities (variations and copy number, i.e. mtDNAcn, change) and elevated ROS have been reported in cancer compared to normal cells. Since excessive levels of ROS can trigger apoptosis, treating cancer cells with ROS-stimulating agents may enhance their death. This study aimed to investigate the link between baseline ROS levels and mitochondrial genetic abnormalities, and how mtDNA abnormalities might be used to predict cancer cells’ response to ROS-stimulating therapy.
Methods Intracellular and mitochondrial specific-ROS levels were measured using the DCFDA and MitoSOX probes, respectively, in four cancer and one non-cancerous cell lines. Cells were treated with ROS-stimulating agents (cisplatin and dequalinium) and the IC50s were determined using the MTS assay. Sanger sequencing and qPCR were conducted to screen the complete mitochondrial genome for variations and to relatively quantify mtDNAcn, respectively. Non-synonymous variations were subjected to 3-dimensional (3D) protein structural mapping and analysis.
Results Our data revealed novel significant associations between the total number of variations in the mitochondrial respiratory chain (MRC) complex I and III genes, mtDNAcn, ROS levels, and ROS-associated drug response. Furthermore, functional variations in complexes I/III correlated significantly and positively with mtDNAcn, ROS levels and drug resistance, indicating they might mechanistically influence these parameters in cancer cells.
Conclusions Our findings suggest that mtDNAcn and complexes I/III functional variations have the potential to be efficient biomarkers to predict ROS-stimulating therapy efficacy in the future.
Keywords
Mitochondrial DNA, MtDNA variations, MtDNA copy number, Reactive oxygen species, Cisplatin, Dequalinium chloride hydrate, ROS-stimulating therapy, Cancer biomarker
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
This is a list of supplementary files associated with this preprint. Click to download.
- SupplementaryinformationnewAnZaidieh.pdf
Supplementary information. Figure S1. Representative image of agarose gel electrophoresis of PCR products. Figure S2. Correlation between the D-loop variations and the baseline intracellular ROS level, mitochondrial superoxide level, drug resistance against CDDP and DQA, relative content of mtDNA and the total number of variations. Figure S3. Correlation between the total variations and the baseline intracellular ROS level, mitochondrial superoxide level, drug resistance against CDDP and DQA and relative content of mtDNA. Table S1. List of common variations identified in the 5 cell lines. Table S2. List of unique variations identified in the 5 cell lines. Table S3. Summary of frequency in healthy tissues and heritability of functional variations identified in the 5 cell lines. Table S4. Summary of correlations between mtDNA parameters and ROS-stimulating drug IC50s, intracellular and mitochondrial ROS. Table S5. List of the primers designed to amplify 17 overlapping mtDNA fragments.
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Revision
Version 1
Posted 16 Dec, 2020
No community comments so far
Editorial decision: Major revision
On 21 Jan, 2021
Review #3 received
Received 06 Jan, 2021
Review #5 received
Received 06 Jan, 2021
Review #2 received
Received 06 Jan, 2021
Review #7 received
Received 06 Jan, 2021
Review #8 received
Received 06 Jan, 2021
Review #9 received
Received 06 Jan, 2021
Review #6 received
Received 06 Jan, 2021
Review #1 received
Received 06 Jan, 2021
Review #4 received
Received 06 Jan, 2021
Reviewer #5 agreed
On 05 Jan, 2021
Reviewer #6 agreed
On 05 Jan, 2021
Reviewer #9 agreed
On 05 Jan, 2021
Reviewer #12 agreed
On 05 Jan, 2021
Reviewer #17 agreed
On 05 Jan, 2021
Reviewer #18 agreed
On 05 Jan, 2021
Reviewer #10 agreed
On 05 Jan, 2021
Reviewer #13 agreed
On 05 Jan, 2021
Reviewer #21 agreed
On 24 Dec, 2020
Reviewer #26 agreed
On 24 Dec, 2020
Reviewer #2 agreed
On 24 Dec, 2020
Reviewer #1 agreed
On 24 Dec, 2020
Reviewer #4 agreed
On 24 Dec, 2020
Reviewer #24 agreed
On 24 Dec, 2020
Reviewer #7 agreed
On 24 Dec, 2020
Reviewer #11 agreed
On 24 Dec, 2020
Reviewer #29 agreed
On 24 Dec, 2020
Reviewer #14 agreed
On 24 Dec, 2020
Reviewer #31 agreed
On 24 Dec, 2020
Reviewer #16 agreed
On 24 Dec, 2020
Reviewer #28 agreed
On 24 Dec, 2020
Reviewer #8 agreed
On 24 Dec, 2020
Reviewer #19 agreed
On 24 Dec, 2020
Reviewer #3 agreed
On 24 Dec, 2020
Reviewer #33 agreed
On 24 Dec, 2020
Reviewer #34 agreed
On 24 Dec, 2020
Reviewer #15 agreed
On 24 Dec, 2020
Reviewer #35 agreed
On 24 Dec, 2020
Reviewer #32 agreed
On 24 Dec, 2020
Reviewer #27 agreed
On 24 Dec, 2020
Reviewer #25 agreed
On 24 Dec, 2020
Reviewer #30 agreed
On 24 Dec, 2020
Reviewers invited
Invitations sent on 15 Dec, 2020
Editor assigned
On 15 Dec, 2020
Editor invited
On 15 Dec, 2020
Submission checks complete
On 15 Dec, 2020
First submitted
On 23 Nov, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Learn more about our company.
This preprint is under consideration at BMC Cancer. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research Article
Mitochondrial DNA abnormalities provide mechanistic insight and predict reactive oxygen species-stimulating drug efficacy
Qian An
University of Portsmouth
Corresponding Author
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Revision
Version 1
Posted 16 Dec, 2020
No community comments so far
Editorial decision: Major revision
On 21 Jan, 2021
Review #3 received
Received 06 Jan, 2021
Review #5 received
Received 06 Jan, 2021
Review #2 received
Received 06 Jan, 2021
Review #7 received
Received 06 Jan, 2021
Review #8 received
Received 06 Jan, 2021
Review #9 received
Received 06 Jan, 2021
Review #6 received
Received 06 Jan, 2021
Review #1 received
Received 06 Jan, 2021
Review #4 received
Received 06 Jan, 2021
Reviewer #5 agreed
On 05 Jan, 2021
Reviewer #6 agreed
On 05 Jan, 2021
Reviewer #9 agreed
On 05 Jan, 2021
Reviewer #12 agreed
On 05 Jan, 2021
Reviewer #17 agreed
On 05 Jan, 2021
Reviewer #18 agreed
On 05 Jan, 2021
Reviewer #10 agreed
On 05 Jan, 2021
Reviewer #13 agreed
On 05 Jan, 2021
Reviewer #21 agreed
On 24 Dec, 2020
Reviewer #26 agreed
On 24 Dec, 2020
Reviewer #2 agreed
On 24 Dec, 2020
Reviewer #1 agreed
On 24 Dec, 2020
Reviewer #4 agreed
On 24 Dec, 2020
Reviewer #24 agreed
On 24 Dec, 2020
Reviewer #7 agreed
On 24 Dec, 2020
Reviewer #11 agreed
On 24 Dec, 2020
Reviewer #29 agreed
On 24 Dec, 2020
Reviewer #14 agreed
On 24 Dec, 2020
Reviewer #31 agreed
On 24 Dec, 2020
Reviewer #16 agreed
On 24 Dec, 2020
Reviewer #28 agreed
On 24 Dec, 2020
Reviewer #8 agreed
On 24 Dec, 2020
Reviewer #19 agreed
On 24 Dec, 2020
Reviewer #3 agreed
On 24 Dec, 2020
Reviewer #33 agreed
On 24 Dec, 2020
Reviewer #34 agreed
On 24 Dec, 2020
Reviewer #15 agreed
On 24 Dec, 2020
Reviewer #35 agreed
On 24 Dec, 2020
Reviewer #32 agreed
On 24 Dec, 2020
Reviewer #27 agreed
On 24 Dec, 2020
Reviewer #25 agreed
On 24 Dec, 2020
Reviewer #30 agreed
On 24 Dec, 2020
Reviewers invited
Invitations sent on 15 Dec, 2020
Editor assigned
On 15 Dec, 2020
Editor invited
On 15 Dec, 2020
Submission checks complete
On 15 Dec, 2020
First submitted
On 23 Nov, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background Associations between mitochondrial genetic abnormalities (variations and copy number, i.e. mtDNAcn, change) and elevated ROS have been reported in cancer compared to normal cells. Since excessive levels of ROS can trigger apoptosis, treating cancer cells with ROS-stimulating agents may enhance their death. This study aimed to investigate the link between baseline ROS levels and mitochondrial genetic abnormalities, and how mtDNA abnormalities might be used to predict cancer cells’ response to ROS-stimulating therapy.
Methods Intracellular and mitochondrial specific-ROS levels were measured using the DCFDA and MitoSOX probes, respectively, in four cancer and one non-cancerous cell lines. Cells were treated with ROS-stimulating agents (cisplatin and dequalinium) and the IC50s were determined using the MTS assay. Sanger sequencing and qPCR were conducted to screen the complete mitochondrial genome for variations and to relatively quantify mtDNAcn, respectively. Non-synonymous variations were subjected to 3-dimensional (3D) protein structural mapping and analysis.
Results Our data revealed novel significant associations between the total number of variations in the mitochondrial respiratory chain (MRC) complex I and III genes, mtDNAcn, ROS levels, and ROS-associated drug response. Furthermore, functional variations in complexes I/III correlated significantly and positively with mtDNAcn, ROS levels and drug resistance, indicating they might mechanistically influence these parameters in cancer cells.
Conclusions Our findings suggest that mtDNAcn and complexes I/III functional variations have the potential to be efficient biomarkers to predict ROS-stimulating therapy efficacy in the future.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8