*5.9. Principal Component Analysis*

Principal component analysis (PCA) was applied to find which linear combinations of the differentially expressed proteins with ≥1.5 would explain most of the variability for the different cell lineage conditions. The PCA analysis was performed using the R-statistics packages FactoMineR (accessed on 1 November 2020) [155] and Factoextra (http://www.sthda.com/english/rpkgs/factoextra accessed on 1 November 2020) for graphical visualization.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/toxins13080519/s1, Figure S1: Optical microscopy analysis of breast cancer cell lines treated with different concentrations of *B. jararaca* snake venom. MCF7 (a) and MDA-MB-231 (b) cell lines (10× magnification), Figure S2: Functional classification of the proteins presenting fold change (FC) ≥ 1.5 according to Molecular Function GO enrichment analysis. (a) MCF7 cell line. (b) MDA-MB-231 cell line, Figure S3: Functional classification of the proteins presenting FC ≥ 1.5 according to the Biological Process GO enrichment analysis. (a) MCF7 cell line. (b) MDA-MB-231 cell line, Figure S4: Functional classification of the proteins presenting FC ≥ 1.5 according to the Cellular Component GO enrichment analysis. (a) MCF7 cell line. (b) MDA-MB-231 cell line, Figure S5: Functional classification of the proteins presenting FC ≥ 1.5 according to Protein Family Classification GO enrichment analysis. (a) MCF7 cell line. (b) MDA-MB-231 cell line, Figure S6a: Protein-protein interaction of proteins identified in MCF7 cell line presenting FC ≤ 0.67 in cells treated with 2.5 μg/mL of *B. jararaca* venom compared to control, Figure S6b: Protein-protein interaction of proteins identified in MCF7 cell line presenting FC ≥ 1.5 in cells treated with 0.67 μg/mL of *B. jararaca* venom compared to control, Figure S6c: Protein-protein interaction of proteins identified in MCF7 cell line presenting FC ≤ 0.67 when in cells treated with 0.63 μg/mL of *B. jararaca* venom compared to control, Supplemental Figure S7a: Protein-protein interaction of proteins identified in MDA-MB-231 cell line presenting FC ≤ 0.67 in cells treated with 2.5 μg/mL of *B. jararaca* venom compared to control, Figure S7b: Protein-protein interaction of proteins identified in MDA-MB-231 cell line presenting FC ≤ 0.67 in cells treated with 0.63 μg/mL of *B. jararaca* venom compared to control, Figure S7c: Protein-protein interaction of proteins identified in MDA-MB-231 cell line presenting FC ≥ 2.5 in cells treated with 0.63 μg/mL of *B. jararaca* venom compared to control, Figure S8: Intensity plots of proteins identified exclusively in one or two of the conditions tested (Control, 0.63 μg/mL or 2.5 μg/mL of *B. jararaca* venom) in both MCF7 and MDA-MB-231 cell lines (Values presented in Table S4). (a) Proteins identified exclusively in the control group. (b) Proteins identified exclusively in the 0.63 μg/mL of venom treatment. (c) Proteins identified exclusively in the 2.5 μg/mL of venom treatment. (d) Proteins identified exclusively in the 0.63 and 2.5 μg/mL of venom treatments. (e) Proteins identified exclusively in the control group and 2.5 μg/mL of venom treatments. (f) Proteins identified exclusively in the control group and 0.63 μg/mL of venom treatment, Table S1a: Mass spectrometry-based proteomics analysis of MCF7 cell line treated with PBS (CTRL), 0.63 μg/mL and 2.5 μg/mL of *B. jararaca* snake venom, Table S2a: Mass spectrometry-based proteomics analysis of MCF7 cell lines treated with PBS (CTRL), 0.63 mg/mL and 2.5 μg/mL of *B. jararaca* snake venom. Fold change based on the control LFQ intensity, Table S1b: Mass spectrometry-based proteomics analysis of MDA-MB-231 cell line treated with PBS (CTRL), 0.63 μg/mL, and 2.5 μg/mL of *B. jararaca* snake venom, Table S2b: Mass spectrometry-based proteomics analysis of MDA-MB-231 cell lines treated with PBS (CTRL), 0.63 μg/mL and 2.5 μg/mL of *B. jararaca* snake venom. Fold change based on the control LFQ intensity, Table S3: Protein list of each of the seven clusters corresponding to Figure 3, Table S4a: MCF7 proteins identified exclusively at one or two of the conditions tested: PBS (CTRL), 0.63 μg/mL and 2.5 μg/mL of *B. jararaca* snake venom, Table S4b: MDA-MB-231 proteins identified exclusively at one or two of the conditions tested: PBS (CTRL), 0.63 μg/mL and 2.5 μg/mL of *B. jararaca* snake venom.

**Author Contributions:** Conceptualization, L.K.I.; methodology, L.K.I.; validation, C.Y.K. and S.S.S.A.; formal analysis, C.Y.K., S.S.S.A., F.M., W.d.S.S., H.M.C., D.C.-C., E.S.F., M.Y.N.-J. and L.K.I., investigation, C.Y.K., S.S.S.A., I.F.L., and D.C.-C.; resources, L.K.I.; data curation, M.Y.N.-J.; writing—original draft preparation, C.Y.K., S.S.S.A., E.S.F., M.Y.N.-J. and L.K.I.; writing—review and editing, C.Y.K., E.S.F., M.Y.N.-J. and L.K.I.; supervision, E.S.F., M.Y.N.-J. and L.K.I.; project administration, L.K.I.; funding acquisition, E.S.F. and L.K.I. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by grants 2013/07467-1, 2016/04000-3, and 2017/17943-6 from the São Paulo Research Foundation (FAPESP). C.Y.K. was supported by FAPESP master's degree program fellowship 2017/06496-9. E.S.F. was supported by Erna and Jakob Michael "Visiting Professorship", Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel and grant 302809/2016-3 from the Brazilian National Council for Scientific and Technological Development, CNPq, Brazil. F.M., W.d.S.S. and S.S.S.A. were supported by the Coordination for the Improvement of Higher Education Personnel (CAPES, Brazil) and CNPq institutional fellowship #88882.442313/2019-01 (Butantan Institute, Brazil) for W.d.S.S. and # 131408/2019-4 for S.S.S.A. (University of São Paulo, Brazil).

**Institutional Review Board Statement:** The methods and use of venom in this work were approved by Butantan Institute Ethics Committee under the certification CEUAIB #9766150719 (2019).

**Informed Consent Statement:** Not Applicable.

**Data Availability Statement:** All generated raw files for these analyses were uploaded and are available at: http://massive.ucsd.edu/MSV000084138/ (acccessed on 5 July 2021).

**Acknowledgments:** We thank Solange M.T. Serrano, Hugo A. Armelin and Zhibin Chen for useful discussion.

**Conflicts of Interest:** The authors declare that there is no conflict of interest.

#### **References**

