Effects of Chemotherapy for Metastatic Colorectal Cancer on the TGF-β Signaling and Related miRNAs hsa-miR-17-5p, hsa-miR-21-5p and hsa-miR-93-5p

Abstract

Metastatic colorectal cancer (mCRC) patients are treated with standard chemotherapeutic drugs in the form of FOLFOX and FOLFIRI regimens. There are no reliable markers that could predict response to chemotherapy for mCRC. TGF-β signaling which interacts with microRNA (miRNA) network has important roles in tumor progression and chemotherapy resistance, thus the interplay between TGF-β signaling and miRNAs could be crucial for treatment response. The aim of this study was to analyze the effect of chemotherapy for mCRC on TGF-β signaling and related miRNAs. Hsa-miR-17-5p, hsa-miR-21-5p and hsa-miR-93-5p were selected out of 316 miRNAs with multiple targets within the TGF-β signaling by in silico analysis. SW620 cells were treated with chemotherapeutic drugs for mCRC for 1, 3 and 6 days and expression of selected miRNAs, PAI-1, CDH1 and VIM was measured. Expression of TGF-β signaling-related hsa-miR-17-5p, hsa-miR-21-5p and hsa-miR-93-5p was time-dependently altered in SW620 cells treated with chemotherapeutics for mCRC. The expression of hsa-miR-93-5p remained downregulated after 6 days under combined treatments FOX and FIRI as well as the hsa-miR-17-5p expression under FIRI. Chemotherapy regimens for mCRC increased expression of a major TGF-β signaling target gene PAI-1, independently of the selected miRNAs expression. These treatments also increased the expression of epithelialmesenchymal transition (EMT) markers CDH1 and VIM on day 3 resulting in decrease of mesenchymal-like characteristics. However, their expression returned close to basal level on day 6. In conclusion, after initial response to chemotherapeutic drugs SW620 cells start to return close to the basal mesenchymal state while the long-term downregulated expression pattern of hsa-miR-93-5p and hsa-miR-17-5p makes them candidates worth testing as biomarkers for monitoring combined chemotherapeutic treatments therapy response in mCRC patients.Keywords Metastatic colorectal cancer • Chemotherapy • microRNA • TGF-β signaling • Epithelial-mesenchymal transition * Jovana Despotovic

Prognostic potential of circulating miR-93-5p in patients with colorectal cancer liver metastases

“…We have showed that 250 µg/ml bevacizumab alone or in combination with FOX does not influence miR-93-5p expression in SW620 cells. In this study, miR-93-5p expression was stable even under FOX which is in contrast to our previous findings were miR-93-5p expression was downregulated after 72 h of treatment with FOX in the same cell line [30]. The only difference in the two experimental settings was the endogenous control used, RNU6B which was used in the previous study and miR-16-5p which was used here, although both endogenous controls have been previously reported to ha normalization in SW620 cells [61,37].…”

“…(5-FU) (EBEWE Phar aliplatin (Actavis, Italy), as reported previously [30] or with 3 clinically relevant concentrations of bevacizumab (Avastin®, Roche, Switzerland) based on its clinical pharmacokinetics analysis: 25 µg/ml (concentration below steady-state), 85 µg/ml (steadystate concentration) [32,33] and 250 µg/ml (average concentration of maximal plasma concentration reported in Liston et al [34] and Zhi et al [33] or with a FOX/bevacizumab combinations.…”

“…MiRNAs have been reported as promising tissues and blood biomarkers for prediction of response to systemic and targeted therapy in CRC patients [51]. Our previous study showed that miR-93-5p was down-regulated long-term under 5-FU, oxaliplatin, irinotecan and 5-FU/oxaliplatin and 5-FU/irinotecan combinations in SW620 cells [30]. Hence, we first examined if the CRLM and serum miR-93-5p expression was altered in patients who received 5-FU-based neoadjuvant chemotherapy with regard to those who have not.…”

“…In our previous study, we have showed that expression of miR-93-5p was downregulated in response to chemotherapy for mCRC in SW620 cells [30]. Two studies have showed that decreased tumoral expression of miR-93 could be used as a novel prognostic factor for CRC [25,31].…”

Exosomal MicroRNA as Biomarkers for Diagnosing or Monitoring the Progression of Ovarian Clear Cell Carcinoma: A Pilot Study

“…Among the miRNAs significantly overexpressed in CCCO cells, miR-21-5p is one of the first identified miRNAs and has been extensively studied as a representative molecule [45]. Previous studies have shown that the plasma level of exosomal miR-21-5p could be used as a biomarker for several cancers, including breast [46] and colorectal [47] cancers and gastric cancer in young patients [48]. MiR-21 is significantly upregulated in endometriosisassociated ovarian cancer, which is characterized by decreased expression of PTEN [49], a well-known tumor suppressor whose inactivation is an early event of malignant transformation from endometriosis [50].…”