SOD1 1.07 μM (IC50)
LCS-1 targets superoxide dismutase 1 (SOD1), an enzyme that catalyzes the dismutation of superoxide radicals into oxygen and hydrogen peroxide. By inhibiting SOD1 with an IC50 of 1.07 μM, LCS-1 increases oxidative stress within cells. This leads to the induction of apoptosis in multiple myeloma cells and growth inhibition in lung adenocarcinoma cells. LCS-1 also inhibits serum-induced activation of ERK and PI3K/AKT signaling pathways.

HCT116 cells that express the bloom syndrome gene product (BLM) or lack it are specifically cytotoxic to LCS-1 (1–10,000 nM; 24 hours) [1]. LCS-1 targets normal human bronchial epithelial (NHBE) cells (IC 50=2.66 μM) and 10/27 adenocarcinoma cell lines (median IC50=0.20 μM; such as H23, H2347, and HCC827 cell lines) [2]. In multiple myeloma (MM) cells, LCS-1 (0, 1.25, 2 μM; 4 hours) significantly inhibits SOD1 enzymatic activity in a concentration-dependent manner [3]. The viability of other MM cell lines, such as MM.1R (dexamethasone-resistant), Dox40 (doxorubicin-resistant), or LR5 (melphalan-resistant), is reduced in a dose-dependent manner by LCS-1 (0, 1.25, 2.5, and 5 μM; 48 hours) [3]. LCS-1 (48 hours) had an IC50 value of 2.5 and 4.6 μM, respectively, on the viability of ANBL6-WT (bortezomib-sensitive) and ANBL6-BR (bortezomib-resistant) cells [3]. In MM.1S cells, LCS-1 (1.25 μM; 16 h) dramatically raised ROS and O2 levels [3]. In MM.1S cells, LCS-1 (1.25 μM; 16 hours) significantly reduced the GSH/GSSG ratio [3]. In MM.1S cells, LCS-1 (1.25 μM; 24 hours) enriches proteins that mediate mtUPR signaling (HSP60/CLPP) and stimulates the release of mitochondrial cytochrome-c into the cytosol [3]. RP2CP is activated by LCS-1-induced O2 (1.25 μM; 5 hours), and RP dramatically lowers the CP form of the 126S proteasome [3]. MM.1S cells undergo both early and late apoptosis when exposed to LCS-1 (2 μM; 16 hours) [3]. In MM.1S cells, LCS-1 (0, 0.5, 1, 1.5, or 2 μM) downregulates MCL-1, BclxL, or c-Myc and upregulates p53/p21 signaling [3]. When applied to mitochondrial unfolded protein response (UPR) proteins (BIP, PERK, phosphorylated eIF2α, or lectin proteins) in MM.1S and ANBL6-BR cells, LCS-1 (0, 4, 8, 16, 24 hours; 2 μM) demonstrates a strong and quick induction [3].

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In vitro, LCS-1 inhibits SOD1 activity with an IC50 of 1.07 μM. It induces early- and late-stage apoptosis in multiple myeloma (MM.1S) cells. LCS-1 inhibits the growth of human lung adenocarcinoma cells harboring mutations in EGFR or KRAS with IC50 values of 0.1-1.5 μM. It inhibits serum-induced activation of ERK and PI3K/AKT signaling pathways. These in vitro activities support its potential as an anticancer agent.

In mice harboring MM.1S, LCS-1 (20 mg/kg; intraperitoneally given every other day for 14 days) suppresses MM growth and prolongs host survival [3].

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In vivo data for LCS-1 is not extensively reported in publicly available sources. As a SOD1 inhibitor with anticancer activity in vitro, the compound has potential applications in animal models of multiple myeloma, lung adenocarcinoma, and other cancers where oxidative stress plays a role. However, specific published in vivo efficacy studies are not detailed in the current literature. LCS-1 is primarily used as a research tool for studying SOD1 biology and oxidative stress in cancer.

The in vitro SOD1 inhibition assay for LCS-1 uses purified SOD1 enzyme and measures its activity using a suitable substrate such as xanthine/xanthine oxidase or a chromogenic assay. Enzyme activity is measured spectrophotometrically, and IC50 values are calculated from dose-response curves. Apoptosis assays are performed in multiple myeloma cells using flow cytometry with Annexin V/PI staining. Growth inhibition is assessed in lung adenocarcinoma cells using standard cell viability assays.

Cell Viability Assay[1]
Cell Types: BLM-proficient and BLM-deficient HCT116 cells
Tested Concentrations: 1-10000 nM
Incubation Duration: 24 hrs (hours)
Experimental Results: Had IC50 values of 1462 nM and 24.92 nM for the viability of BLM-proficient and BLM-deficient HCT116 cells, respectively.

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Western Blot Analysis[3]
Cell Types: MM.1S and ANBL6-BR cells
Tested Concentrations: 2 μM
Incubation Duration: 16 hrs (hours)
Experimental Results: diminished the expression of cell-cycle regulatory proteins (cyclin-B1, CDC25C, and CDC2).

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Western Blot Analysis[3]
Cell Types: MM.1S cells
Tested Concentrations: 0, 0.5, 1, 1.5, 2 μM
Incubation Duration:
Experimental Results: Upregulated p53/p21 signaling, as well as downregulated survival pathway proteins MCL-1, BclxL, or c-Myc.

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Western Blot Analysis[3]
Cell Types: MM.1S cells
Tested Concentrations: 2 μM
Incubation Duration: 0, 4, 8, 16, 24 hrs (hours)
Experimental Results: demonstrated a rapid and robust induction of UPR proteins (BIP, PERK, phosphorylated eIF2α, or a lectin protein calnexin).

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Cellular assays for LCS-1 are conducted in multiple myeloma (MM.1S) cells and lung adenocarcinoma cells. Cells are treated with varying concentrations of LCS-1. Apoptosis is assessed by flow cytometry using Annexin V/PI staining and caspase activity assays. Cell viability and proliferation are measured using standard assays such as MTT or CellTiter-Glo. ERK and PI3K/AKT signaling are assessed by Western blotting for phosphorylated ERK and AKT.

Animal/Disease Models: 5weeks old female CB17 SCID (severe combined immunodeficient) mouse (MM.1S tumors volume=100 mm3)[3]
Doses: 20 mg/kg (diluted in saline)
Route of Administration: intraperitoneal (ip)injections; treated on an every other day schedule for 14 days
Experimental Results: Inhibited MM growth and prolongs host survival.

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In vivo studies for LCS-1 would typically involve xenograft mouse models of multiple myeloma or lung adenocarcinoma. The compound would be administered via intraperitoneal or oral routes at doses determined by pharmacokinetic studies. Efficacy would be assessed by measuring tumor growth inhibition. However, specific published in vivo protocols for LCS-1 are not available in the current literature. The compound is currently used as a research tool for studying SOD1 and oxidative stress in cancer.

Pharmacokinetic data for LCS-1 is not extensively reported in publicly available sources. The compound has a molecular weight of 255.10 g/mol and a molecular formula of C11H8Cl2N2O. It has a CAS number of 41931-13-9. Storage: at 20°C for 2 years. As a small molecule SOD1 inhibitor, it is expected to have moderate bioavailability. Detailed PK parameters such as half-life are not available in the current literature for this research compound.

Toxicity data for LCS-1 is limited in publicly available sources. As with all research compounds, LCS-1 is intended for research use only and not for human therapeutic applications. The compound's mechanism of increasing oxidative stress suggests potential toxicity concerns that would need to be addressed. Standard in vitro cytotoxicity assays and in vivo tolerability studies would be required for a complete toxicity assessment.

[1]. Nanocarrier Composed of Magnetite Core Coated with Three Polymeric Shells Mediates LCS-1 Delivery for Synthetic Lethal Therapy of BLM-Defective Colorectal Cancer Cells. Biomacromolecules. 2018 Mar 12;19(3):803-815.

[2]. Superoxide dismutase 1 (SOD1) is a target for a small molecule identified in a screen for inhibitors of the growth of lung adenocarcinoma cell lines. Proc Natl Acad Sci U S A. 2011;108(39):16375-16380.

[3]. Proteomic analysis identifies mechanism(s) of overcoming bortezomib resistance via targeting ubiquitin receptor Rpn13. Leukemia. 2021 Feb;35(2):550-561.

LCS-1 (CAS 41931-13-9) is a SOD1 inhibitor with an IC50 of 1.07 μM. It induces apoptosis in multiple myeloma cells and inhibits the growth of lung adenocarcinoma cells harboring EGFR or KRAS mutations. LCS-1 inhibits serum-induced ERK and PI3K/AKT signaling. It has a molecular formula of C11H8Cl2N2O and a molecular weight of 255.10 g/mol. LCS-1 is a valuable research tool for studying SOD1, oxidative stress, and cancer biology.

C11H8CL2N2O

255.10

254.001

41931-13-9

779573

Light yellow to light brown solid powder

1.39g/cm3

339.6ºC at 760 mmHg

159.2ºC

1.627

2.847

0

2

1

16

365

0

SYUPLLHVMCLXEM-UHFFFAOYSA-N

InChI=1S/C11H8Cl2N2O/c1-7-3-2-4-8(5-7)15-11(16)10(13)9(12)6-14-15/h2-6H,1H3

4,5-dichloro-2-(3-methylphenyl)pyridazin-3-one

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : 50 mg/mL (196.00 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.80 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)