ABSTRACT
Background: Breast cancer is a heterogeneous disease characterized by differential responses to targeted and chemotherapeutic agents. Antibody-drug conjugates are one of the promising strategies for the treatment of breast cancer. Monomethyl auristatin E [MMAE] is a highly potent microtubule inhibitor and a common payload used for development of antibody-drug conjugates. The purpose of this study was to investigate the cytotoxic effects of MMAE on breast cancer cell lines
Materials and Methods: MDA-MB-468 and MDA-MB-453 cells were treated with MMAE at various concentrations [1, 10, 100, and 1000 ng/ml], and cytotoxicity was measured after 48 and 72 hours using an MTT assay
Results: Our findings indicated that MMAE possesses dose- and time-dependent cytotoxic activities against human breast cancer cells. The morphological features of the treated cells were supportive of the cytotoxic activity of MMAE. The results of the MTT assay showed that MMAE has a significant cytotoxicity against MDA-MB-468 and, to a lesser degree, MDA-MB-453 cells
Conclusion: MMAE can be used as a highly cytotoxic payload for development of antibody-drug conjugates against breast cancer
ABSTRACT
Background: Monomethyl auristatin E [MMAE] is a synthetic analog of dolastatin 10, a compound originally isolated from the marine mollusk. MMAE, as a highly potent microtubule inhibitor, exerts its potent cytotoxic effect by inhibiting microtubule assembly, tubulin-dependent GTP hydrolysis and microtubes polymerization. This molecule, by itself, lacks the tumor specificity required to elicit therapeutic benefit. Nevertheless, the extremely cytotoxic potential of MMAE could be harnessed in the form of MMAE-antibody conjugates. The aim of the present study was to evaluate the cytotoxic activity of MMAE against breast [SKBR3] and kidney [HEK293] cancer cell lines in an in vitro cell-based assay
Materials and Methods: SKBR3 and HEK293 cells were treated with different concentrations ranging from 0.002048, 0.01024, 0.0512, 0.256, 1.28, 6.4, 32, 160, 800 and 4000 nM of MMAE, and cell viability was determined after 72 hours using an MTT colorimetric assay. The effect of MMAE was regularly monitored by direct observation using an invert microscope
Results: Microscopic observation showed that there was a concentration-dependent increase in cell death
Results from the MTT assay revealed a statistically significant loss of viability [P<0.0001] at concentrations ranging from 0.01024 to 4000 nM in SKBR3 cells, and 0.0512 to 4000 nM in HEK293 cells. Our findings showed that MMAE inhibited the growth of SKBR3 and HEK293 cells in a concentration-dependent manner, with IC50 values of 3.27 +/- 0.42 and 4.24 +/- 0.37 nM, respectively
Conclusion: MMAE was able to significantly inhibit cell growth at nanomolar concentrations, emphasizing its great potential for the development of antibody-drug conjugates
Subject(s)
HEK293 Cells , Cell Line, Tumor , In Vitro Techniques , Kidney Neoplasms , OligopeptidesABSTRACT
Neurokinin 1 receptors [NK[1]R] are overexpressed on several types of important human cancer cells. Substance P [SP] is the most specific endogenous ligand known for NK1Rs. Accordingly,a new SP analogue was synthesized and evaluated for detection of NK[1]R positive tumors.[6-hydrazinopyridine-3-carboxylic acid [HYNIC]-Tyr[8]-Met[O][11]-SP] was synthesized and radiolabeled with 99mTc using ethylenediamine-N,N-diacetic acid [EDDA]and Tricine as coligands. Common physicochemical properties of radioconjugate were studied and in-vitro cell line biological tests were accomplished to determine the receptor mediated characteristics. In-vivo biodistribution in normal and tumor bearingnude mice was also assessed. The cold peptide was prepared in high purity [>99%] and radiolabeled with [99m]Tc at high specific activities [84-112GBq/ micro mol] with an acceptable labeling yield [>95%]. The radioconjugate was stable in-vitro in the presence of human serum and showed 44% protein binding to human serumalbumin. In-vitro cell line studies on U373MG cells showed an acceptable uptake up to 4.91 +/- 0.22% with the ratio of 60.21 +/- 1.19% for its specific fraction and increasing specific internalization during 4 h. Receptor binding assays on U373MG cells indicated a mean Kd of 2.46 +/- 0.43 nM and Bmax of 128925 +/- 8145 sites/cell. In-vivo investigations determined the specific tumor uptake in 3.36 percent of injected dose per gram [%ID/g] for U373MG cells and noticeable accumulations of activity in the intestines and lung. Predominant renal excretion pathway was demonstrated. Therefore, this new radiolabeled peptide could be a promising radiotracer for detection of NK[1]R positive primary or secondary tumors