ALDH1A inhibition sensitizes colon cancer cells to chemotherapy

Abstract

BackgroundRecent evidence in cancer research, developed the notion that malignant tumors consist of different subpopulations of cells, one of them, known as cancer stem cells, being attributed many important properties such as enhanced tumorigenicity, proliferation potential and profound multidrug resistance to chemotherapy. Several key stem cells markers were identified in colon cancer. In our study we focused on the aldehyde dehydrogenase type 1 (ALDH1) expression in colon cancer-derived cell lines HT-29/eGFP, HCT-116/eGFP and LS-180/eGFP, and its role in the chemoresistance and tumorigenic potential.MethodsThe effect of pharmacological inhibition of ALDH activity by diethylaminobenzaldehyde (DEAB) and also effect of molecular inhibition by specific siRNA was evaluated in vitro in cultures of human colorectal cell lines. The expression level of different isoenzymes of aldehyde dehydrogenase was determined using qPCR. Changes in cell biology were evaluated by expression analysis, western blot and apoptosis assay. The efficiency of cytotoxic treatment in the presence of different chemotherapeutic drugs was analyzed by fluorimetric assay. Tumorigenicity of cells with specific ALDH1A1 siRNA was tested in xenograft model in vivo.ResultsTreatment by DEAB partially sensitized the tested cell lines to chemotherapeutics. Subsequently the molecular inhibition of specific isoforms of ALDH by ALDH1A1 or ALDH1A3 siRNA led to sensitizing of cell lines HT-29/eGFP, HCT-116/eGFP to capecitabine and 5-FU. On the model of athymic mice we observed the effect of molecular inhibition of ALDH1A1 in HT-29/eGFP cells by siRNA. We observed inhibition of proliferation of subcutaneous xenografts in comparison to control cells.ConclusionThis research, verifies the significance of the ALDH1A isoforms in multidrug resistance of human colorectal cancer cells and its potential as a cancer stem cell marker. This provides the basis for the development of new approaches regarding the treatment of patients with colorectal adenocarcinoma and potentially the treatment of other tumor malignancies.

Cancer Stem Cells in the Personalized Therapy of Colorectal Cancer

“…With multiple such experiments, we have indicated the increased cytotoxic effect of the drug Raltitrexed on HT-29 and HCT-116 CRC cells compared to the LS-180 CRC cell line-a result associating the different expression profiles of CSC markers, as a possible explanation of this phenomenon, since all three cells lines belong to the same cancer type, namely colorectal carcinoma. The same patterns account for the drug Irinotecan, while our experiments proved that the drug Capecitabine, follow the exact inverse pattern, exhibiting a much greater cytotoxic effect towards LS-180 CRC cells [48].…”

“…Finally, the effect of pharmacological inhibition of several ALDH isozyme activities by the chemical diethylaminobenzaldehyde (DEAB) partially sensitized the tested cell lines to chemotherapeutics: Chemosensitivity test in the presence of a sub-inhibitory concentration of DEAB, confirmed its potential to increase the antiproliferative effect of 5-FU, Irinotecan, Raltitrexed and Cisplatin in colorectal carcinoma cells [48].…”

“…Finally, we have also proven that CRC cells, rendered resistant to the drug 5-FU, change both their chemosensitivity towards the tested anticancer agents, as well as their levels and patterns of CRC-SC marker expression, with the above mentioned results pointing further to the potential of use of CSC and their marker in the personalization of treatment regimens in colorectal neoplasia, stratifying patients according to tumor-CRC-SC types, with the use of such biomarkers, both pre-and post-chemotherapy initiation [48,57].…”

“…Samples after silencing were exposed to 5-FU, Capecitabine, Raltitrexed and Irinotecan, commonly deployed anticancer agents for the treatment of primary, as well as metastatic CRC. Silencing of these two ALDH1A isoforms led to different effect on chemosensitivity to tested drugs [48].…”

Napabucasin overcomes cisplatin resistance in ovarian germ cell tumor-derived cell line by inhibiting cancer stemness

“…Human colon cancer cell line HT-29/EGFP and its chemoresistant derivative HT-29/EGFP/FUR (kindly provided by Dr. Durinikova, Cancer Research Institute BMC SAS, Bratislava) were maintained in high glucose DMEM supplemented with 10% fetal calf serum (FCS; Biochrom AG, Germany), 2 mM glutamine (PAA Laboratories GmbH, Austria) or GlutaMAX (Gibco by Life Technologies, USA), 10 μg/ml gentamicin (Sandoz, Germany) and 2.5 μg/ml amphotericin B (Sigma-Aldrich, USA). Human mesenchymal stromal cells (MSC, kindly provided by Dr. Miklikova, Cancer Research Institute BMC SAS, Bratislava) used in this study were propagated in low glucose (1.0 g/l) DMEM supplemented as described above [24][25][26][27].…”