*2.4. Semi-Quantitative Proteomics Analysis: MCF7 and MDA-MB-231 Cell Line Protein Abundance Variation*

In general, we observed a higher number of proteins whose abundance had changed more than 1.5× or less than 0.67× in MCF7 cell lines when compared to the MDA-MB-231 cell lines. The semi-quantitative analysis of the MCF7 cell line (Table S2a,) treated with 2.5 μg/mL venom allowed us to identify 137 proteins, whose abundance changed over 1.5× (fold change FC ≥ 1.5, marked in light red) when compared to the control group, from which 55 proteins presented FC ≥ 2.0 (marked in red). We highlight 12 highly abundant proteins with FC ≥ 3.0, marked in dark red: Sorting nexin-3 (SNX3), Purine nucleoside phosphorylase (HEL-S-156an), Peroxisome proliferator activated receptor interacting complex protein (PRIC295), Small nuclear ribonucleoprotein component (SNRP116), Eukaryotic translation initiation factor 4B (EIF4B), Methylcrotonoyl-CoA carboxylase beta chain (MCCC2), 26S proteasome non-ATPase regulatory subunit 5 (PSMD5), Heterogeneous nuclear ribonucleoprotein R (HNRNPR), Full-length cDNA clone CS0DJ015YJ12 of T cells (PSME2), Isoleucyl-tRNA synthetase (IARS), Large proline-rich protein BAG6 (BAG6), and Glutathione S-transferase (GSTM3). In addition, we identified 23 proteins with FC ≤ 0.67 (marked in light green) from which five proteins presented FC ≤ 0.5 (marked in dark green): Histone H4 (HIST1H4J), ATP synthase subunit d, mitochondrial (ATP5PD), Voltagedependent anion-selective channel protein 2 (VDAC2), 4a-hydroxytetrahydrobiopterin dehydratase (PCBD), and Histone H3 (H3F3B). At the low 0.63 μg/mL venom treatment, we identified 25 proteins with FC ≥ 1.5 (marked in light red) from which only two proteins presented FC ≥ 2.0 (marked in red): Anterior gradient 2 homolog (AGR2) and Leucine-rich PPR-motif containing protein (LRPPRC); and 19 proteins with FC ≤ 0.67 (marked in light green) from which two proteins with FC ≤ 0.5 (marked in dark green): PCBD and 40S ribosomal protein S29 (RPS29). The description of the highlighted proteins is shown in Table 1.

Semi-quantitative proteomic analysis of the MDA-MB-231 cell line (Table S2b) treated with 2.5 μg/mL allowed the identification of 34 proteins whose abundance changed (FC) ≥1.5 over the control (marked in light red), nine proteins with FC ≥ 2 (marked in red) from which we highlight three proteins with FC ≥ 3 (marked in dark red): Histone H3.2 (H3C15/HIST2H3), 14 kDa phosphohistidine phosphatase (HEL-S-132P), and Mitochondrial carrier homolog 2 (MTCH2). Moreover, 41 proteins presented FC ≤ 0.67 (light green) from which we highlight four proteins with FC ≤ 0.5 (marked in dark green): DnaJ homolog subfamily A member 1 (DNAJA1), Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), Cysteine-rich angiogenic inducer 61 (CYR61), and Thrombospondin-1 (THBS1). At the lower 0.63 μg/mL venom treatment, 16 proteins presented FC ≥ 1.5 (marked in light red) from which we highlight H3C15/HIST2H3 with FC = 3.8 and MTCH2 with FC = 2.3 (marked in red); and 28 proteins with FC ≤ 0.67 (marked in light green) from which 12 proteins with FC ≤ 0.5 (marked in dark green): 60S ribosomal protein L37 (RPL37), D-3-phosphoglycerate dehydrogenase (HEL-S-113), ATPase inhibitor, mitochondrial (ATP5IF1), Non-histone chromosomal protein HMG-14 (HMGN1), RCC2 protein (RCC2), Serine/threonine-protein phosphatase PP1-gamma catalytic subunit (PPP1CC), D-dopachrome decarboxylase (DDT), Ran GTPase-activating protein 1 (RANGAP1), dCTP pyrophosphatase 1 (DCTPP1), IGF2BP1, THBS1, and CYR61 (Table 1).


**Table 1.**

Description

 of the highlighted

 proteins and their association with cancer.




bone glioblastoma:

melanoma: ME, ovarian: OV, pancreatic: PA, prostate: PR, renal: RE, skin: SK, stomach: ST, testis: TE, thyroid: TY, urothelial: UR.

 GB, glioma: GL, head and neck: HN, kidney: KD, laryngeal carcinoma: LC, leukemia: LE, liver: LI, lung: LU, lung

(osteosarcoma):

 BN, breast: BR, cervical: CE,

chondroblastoma:

 CH colon: CL, colorectal: CR, endometrial:

 EN, esophageal: ES, gastric: GA,

adenocarcinoma:

 LA, lung squamous: LS, lymphoma: LY,

gastrointestinal

 stromal tumor: GS
