Overexpression of S100A4 in human cancer cell lines resistant to methotrexate

Abstract

BackgroundMethotrexate is a chemotherapeutic drug that is used in therapy of a wide variety of cancers. The efficiency of treatment with this drug is compromised by the appearance of resistance. Combination treatments of MTX with other drugs that could modulate the expression of genes involved in MTX resistance would be an adequate strategy to prevent the development of this resistance.MethodsThe differential expression pattern between sensitive and MTX-resistant cells was determined by whole human genome microarrays and analyzed with the GeneSpring GX software package. A global comparison of all the studied cell lines was performed in order to find out differentially expressed genes in the majority of the MTX-resistant cells. S100A4 mRNA and protein levels were determined by RT-Real-Time PCR and Western blot, respectively. Functional validations of S100A4 were performed either by transfection of an expression vector for S100A4 or a siRNA against S100A4. Transfection of an expression vector encoding for β-catenin was used to inquire for the possible transcriptional regulation of S100A4 through the Wnt pathway.ResultsS100A4 is overexpressed in five out of the seven MTX-resistant cell lines studied. Ectopic overexpression of this gene in HT29 sensitive cells augmented both the intracellular and extracellular S100A4 protein levels and caused desensitization toward MTX. siRNA against S100A4 decreased the levels of this protein and caused a chemosensitization in combined treatments with MTX. β-catenin overexpression experiments support a possible involvement of the Wnt signaling pathway in S100A4 transcriptional regulation in HT29 cells.ConclusionsS100A4 is overexpressed in many MTX-resistant cells. S100A4 overexpression decreases the sensitivity of HT29 colon cancer human cells to MTX, whereas its knockdown causes chemosensitization toward MTX. Both approaches highlight a role for S100A4 in MTX resistance.

The investigation of epsilon toxin effects on different cancerous cell lines and its synergism effect with methotrexate

“…Methotrexate is a classical folate antagonist, which has a wide application in the treatment of various types of solid tumors, either alone or in combination with other chemotherapeutic agents. [24,25] A major problem in cancer therapy is the emergence of tumor drug resistance with MTX. [6,26] Hence, several other strategies have been developed to overcome this problem.…”

S100A4 and Uric Acid Promote Mesenchymal Stromal Cell Induction of IL-10+/IDO+ Lymphocytes

“…First, S100A4 is overexpressed in colorectal carcinomas, and elevated S100A4 levels are associated with a poor prognosis (19,20). Second, RAGE, the extracellular receptor for S100A4, is expressed on MSCs (26).…”

“…It promotes angiogenesis, cell motility, invasion, and cell survival (19). The expression of S100A4 is increased in colorectal cancer cells (20), and higher serum levels of S100A4 are associated with increased risk of metastasis (19,20 Furthermore, elevated serum levels of S100 proteins, including S100A4, can be detected during inflammation and following trauma (21). The receptor for advanced glycation end products (RAGE) (19,22), the epidermal growth factor receptor (EGFR) (23), and TLR4 (24,25) are extracellular receptors for S100 proteins.…”

The Redox State of Cytochrome C Modulates Resistance to Methotrexate in Human MCF7 Breast Cancer Cells

“…Several MTX resistance mechanisms had been described such as gene amplification of the dhfr locus [5], [6], deficiency in MTX transport [7], [8] or MTX polyglutamation [9], expression of the MDR phenotype and mutations of the target (DHFR protein) [10]. Altered gene or miRNA expression also contribute to MTX resistance such as increases in AKR1C1 [11], S100A4 [12], caveolin-1, enolase-2, PRKCA [13], DKK1, EEF1A1, and UGT1A family [14], [15], and the decrease of E-Cadherin [13] or miR-224 [16].…”